[RFCv12 PATCH 00/29] Request API

[RFCv12 PATCH 00/29] Request API

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

Hi all,

This is version 12 of the Request API series.

The main changes compared to v11 are:

- Improve locking (more about that below)
- Split req_queue into req_validate and req_queue
- Add vb2_m2m_request_queue() helper
- Merge v11 patches 3-5 into one (splitting it up was too confusing)
- Incorporated all (?) v11 comments, except for debug_str: it wasn't
  quite clear to me what I should do there.
- Renamed WHICH_REQUEST to WHICH_REQUEST_VAL for consistency.
- Attempting to queue or reinit a request that is in use will now
  return -EBUSY instead of -EINVAL.
- Added a final RFC patch to ease debugging: it exposes a debugfs
  file that shows how many requests and request objects are in use.
  I don't think this will be merged as I am not really happy about
  it. It's good enough for now, though.

This series has been tested with vim2m, vivid and the cedrus driver.

Regarding locking:

There are two request locks used: req_queue_mutex (part of media_device)
ensures high-level serialization of queueing/reiniting and canceling
requests. It serializes STREAMON/OFF, TRY/S_EXT_CTRLS, close() and
MEDIA_REQUEST_IOC_QUEUE. This is the top-level lock and should be taken
before any others.

The lock spin_lock in struct media_request protects that structure and
should be held for a short time only.

Note that VIDIOC_QBUF/VIDIOC_PREPARE_BUF do not take this mutex: when
a buffer is queued/prepared for a request they will add it to the
request by calling media_request_object_bind(), and that returns an
error if the request is in the wrong state. It is serialized via the
spin_lock which in this specific case is sufficient.

When MEDIA_REQUEST_IOC_QUEUE is called it will validate and queue both
control handlers and vb2 buffers. For control handlers the control handler
lock will be taken, for vb2 buffers the vb2_queue lock will be taken.
This requires that the lock field in vb2_queue is set, which is checked in
videobuf2-v4l2.c.

TODO/Remarks:

1) Still some missing documentation. It's better than v11, but still
   not complete.

2) No VIDIOC_REQUEST_ALLOC 'shortcut' ioctl. I don't think we should
   add this in the initial version due to the fact that it is somewhat
   controversial. It can always be added later.

3) vim2m: the media topology is a bit bogus, this needs to be fixed
   (i.e. a proper HW entity should be added). But for now it is
   good enough for testing. In addition as suggested by Tomasz the
   timer can be replaced by delayed_work.

4) Review copyright/authorship lines. I'm not sure if everything is
   correct. Alexandre, Sakari, if you see something that is not
   right in this respect, just let me know!

5) For the next patch series I plan to drop the 'RFC' tag, except for
   the last debugfs patch.

Everything seemed to slip nicely into place while working on this,
so I hope this is finally an implementation that we can proceed to
upstream and build upon for complex camera pipelines in the future.

This patch series is also available here:

https://git.linuxtv.org/hverkuil/media_tree.git/log/?h=reqv12

Regards,

	Hans


Alexandre Courbot (2):
  videodev2.h: add request_fd field to v4l2_ext_controls
  Documentation: v4l: document request API

Hans Verkuil (27):
  v4l2-device.h: always expose mdev
  uapi/linux/media.h: add request API
  media-request: implement media requests
  v4l2-dev: lock req_queue_mutex
  media-request: add media_request_find
  media-request: add media_request_object_find
  v4l2-ctrls: v4l2_ctrl_add_handler: add from_other_dev
  v4l2-ctrls: prepare internal structs for request API
  v4l2-ctrls: alloc memory for p_req
  v4l2-ctrls: use ref in helper instead of ctrl
  v4l2-ctrls: add core request support
  v4l2-ctrls: support g/s_ext_ctrls for requests
  videodev2.h: Add request_fd field to v4l2_buffer
  vb2: store userspace data in vb2_v4l2_buffer
  videobuf2-core: embed media_request_object
  videobuf2-core: integrate with media requests
  videobuf2-v4l2: integrate with media requests
  videobuf2-core: add vb2_core_request_has_buffers
  videobuf2-v4l2: add vb2_request_queue/validate helpers
  videobuf2-v4l2: export request_fd
  v4l2-mem2mem: add vb2_m2m_request_queue
  media: vim2m: add media device
  vim2m: use workqueue
  vim2m: support requests
  vivid: add mc
  vivid: add request support
  RFC: media-requests: add debugfs node

 Documentation/media/uapi/v4l/buffer.rst       |  19 +-
 Documentation/media/uapi/v4l/common.rst       |   1 +
 Documentation/media/uapi/v4l/request-api.rst  | 218 ++++++++
 .../media/uapi/v4l/vidioc-g-ext-ctrls.rst     |  25 +-
 Documentation/media/uapi/v4l/vidioc-qbuf.rst  |   8 +
 .../media/videodev2.h.rst.exceptions          |   1 +
 drivers/media/Makefile                        |   3 +-
 .../media/common/videobuf2/videobuf2-core.c   | 204 +++++--
 .../media/common/videobuf2/videobuf2-v4l2.c   | 456 ++++++++++------
 drivers/media/dvb-core/dvb_vb2.c              |   5 +-
 drivers/media/dvb-frontends/rtl2832_sdr.c     |   5 +-
 drivers/media/media-device.c                  |  54 ++
 drivers/media/media-devnode.c                 |  17 +
 drivers/media/media-request.c                 | 492 +++++++++++++++++
 drivers/media/pci/bt8xx/bttv-driver.c         |   2 +-
 drivers/media/pci/cx23885/cx23885-417.c       |   2 +-
 drivers/media/pci/cx88/cx88-blackbird.c       |   2 +-
 drivers/media/pci/cx88/cx88-video.c           |   2 +-
 drivers/media/pci/saa7134/saa7134-empress.c   |   4 +-
 drivers/media/pci/saa7134/saa7134-video.c     |   2 +-
 .../media/platform/exynos4-is/fimc-capture.c  |   2 +-
 drivers/media/platform/omap3isp/ispvideo.c    |   4 +-
 drivers/media/platform/rcar-vin/rcar-v4l2.c   |   3 +-
 drivers/media/platform/rcar_drif.c            |   2 +-
 .../media/platform/s3c-camif/camif-capture.c  |   4 +-
 drivers/media/platform/s5p-mfc/s5p_mfc_dec.c  |   4 +-
 drivers/media/platform/s5p-mfc/s5p_mfc_enc.c  |   4 +-
 .../media/platform/soc_camera/soc_camera.c    |   7 +-
 drivers/media/platform/vim2m.c                |  83 ++-
 drivers/media/platform/vivid/vivid-core.c     |  69 +++
 drivers/media/platform/vivid/vivid-core.h     |   8 +
 drivers/media/platform/vivid/vivid-ctrls.c    |  46 +-
 .../media/platform/vivid/vivid-kthread-cap.c  |  12 +
 .../media/platform/vivid/vivid-kthread-out.c  |  12 +
 drivers/media/platform/vivid/vivid-sdr-cap.c  |   8 +
 drivers/media/platform/vivid/vivid-vbi-cap.c  |   2 +
 drivers/media/platform/vivid/vivid-vbi-out.c  |   2 +
 drivers/media/platform/vivid/vivid-vid-cap.c  |   2 +
 drivers/media/platform/vivid/vivid-vid-out.c  |   2 +
 drivers/media/usb/cpia2/cpia2_v4l.c           |   2 +-
 drivers/media/usb/cx231xx/cx231xx-417.c       |   2 +-
 drivers/media/usb/cx231xx/cx231xx-video.c     |   4 +-
 drivers/media/usb/msi2500/msi2500.c           |   2 +-
 drivers/media/usb/tm6000/tm6000-video.c       |   2 +-
 drivers/media/usb/uvc/uvc_queue.c             |   5 +-
 drivers/media/usb/uvc/uvc_v4l2.c              |   3 +-
 drivers/media/usb/uvc/uvcvideo.h              |   1 +
 drivers/media/v4l2-core/v4l2-compat-ioctl32.c |  14 +-
 drivers/media/v4l2-core/v4l2-ctrls.c          | 496 +++++++++++++++++-
 drivers/media/v4l2-core/v4l2-dev.c            |  37 +-
 drivers/media/v4l2-core/v4l2-device.c         |   3 +-
 drivers/media/v4l2-core/v4l2-ioctl.c          |  22 +-
 drivers/media/v4l2-core/v4l2-mem2mem.c        |  40 +-
 drivers/media/v4l2-core/v4l2-subdev.c         |   9 +-
 .../staging/media/davinci_vpfe/vpfe_video.c   |   3 +-
 drivers/staging/media/imx/imx-media-dev.c     |   2 +-
 drivers/staging/media/imx/imx-media-fim.c     |   2 +-
 drivers/staging/media/omap4iss/iss_video.c    |   3 +-
 drivers/usb/gadget/function/uvc_queue.c       |   2 +-
 include/media/media-device.h                  |  28 +
 include/media/media-devnode.h                 |   4 +
 include/media/media-request.h                 | 228 ++++++++
 include/media/v4l2-ctrls.h                    |  45 +-
 include/media/v4l2-device.h                   |   4 +-
 include/media/v4l2-mem2mem.h                  |   4 +
 include/media/videobuf2-core.h                |  38 +-
 include/media/videobuf2-v4l2.h                |  20 +-
 include/uapi/linux/media.h                    |  12 +
 include/uapi/linux/videodev2.h                |  14 +-
 69 files changed, 2519 insertions(+), 330 deletions(-)
 create mode 100644 Documentation/media/uapi/v4l/request-api.rst
 create mode 100644 drivers/media/media-request.c
 create mode 100644 include/media/media-request.h

-- 
2.17.0

[RFCv12 PATCH 01/29] v4l2-device.h: always expose mdev

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

The mdev field is only present if CONFIG_MEDIA_CONTROLLER is set.
But since we will need to pass the media_device to vb2 and the
control framework it is very convenient to just make this field
available all the time. If CONFIG_MEDIA_CONTROLLER is not set,
then it will just be NULL.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 include/media/v4l2-device.h | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/include/media/v4l2-device.h b/include/media/v4l2-device.h
index 0c9e4da55499..b330e4a08a6b 100644
--- a/include/media/v4l2-device.h
+++ b/include/media/v4l2-device.h
@@ -33,7 +33,7 @@ struct v4l2_ctrl_handler;
  * struct v4l2_device - main struct to for V4L2 device drivers
  *
  * @dev: pointer to struct device.
- * @mdev: pointer to struct media_device
+ * @mdev: pointer to struct media_device, may be NULL.
  * @subdevs: used to keep track of the registered subdevs
  * @lock: lock this struct; can be used by the driver as well
  *	if this struct is embedded into a larger struct.
@@ -58,9 +58,7 @@ struct v4l2_ctrl_handler;
  */
 struct v4l2_device {
 	struct device *dev;
-#if defined(CONFIG_MEDIA_CONTROLLER)
 	struct media_device *mdev;
-#endif
 	struct list_head subdevs;
 	spinlock_t lock;
 	char name[V4L2_DEVICE_NAME_SIZE];
-- 
2.17.0

[RFCv12 PATCH 02/29] uapi/linux/media.h: add request API

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

Define the public request API.

This adds the new MEDIA_IOC_REQUEST_ALLOC ioctl to allocate a request
and two ioctls that operate on a request in order to queue the
contents of the request to the driver and to re-initialize the
request.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 include/uapi/linux/media.h | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/include/uapi/linux/media.h b/include/uapi/linux/media.h
index c7e9a5cba24e..32883d4d22b2 100644
--- a/include/uapi/linux/media.h
+++ b/include/uapi/linux/media.h
@@ -342,11 +342,23 @@ struct media_v2_topology {
 
 /* ioctls */
 
+struct __attribute__ ((packed)) media_request_alloc {
+	__s32 fd;
+};
+
 #define MEDIA_IOC_DEVICE_INFO	_IOWR('|', 0x00, struct media_device_info)
 #define MEDIA_IOC_ENUM_ENTITIES	_IOWR('|', 0x01, struct media_entity_desc)
 #define MEDIA_IOC_ENUM_LINKS	_IOWR('|', 0x02, struct media_links_enum)
 #define MEDIA_IOC_SETUP_LINK	_IOWR('|', 0x03, struct media_link_desc)
 #define MEDIA_IOC_G_TOPOLOGY	_IOWR('|', 0x04, struct media_v2_topology)
+#define MEDIA_IOC_REQUEST_ALLOC	_IOWR('|', 0x05, struct media_request_alloc)
+
+/*
+ * These ioctls are called from the request file descriptor as returned
+ * by MEDIA_IOC_REQUEST_ALLOC.
+ */
+#define MEDIA_REQUEST_IOC_QUEUE		_IO('|',  0x80)
+#define MEDIA_REQUEST_IOC_REINIT	_IO('|',  0x81)
 
 #if !defined(__KERNEL__) || defined(__NEED_MEDIA_LEGACY_API)
 
-- 
2.17.0

[RFCv12 PATCH 03/29] media-request: implement media requests

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

Add initial media request support.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/Makefile        |   3 +-
 drivers/media/media-device.c  |  13 ++
 drivers/media/media-request.c | 418 ++++++++++++++++++++++++++++++++++
 include/media/media-device.h  |  17 ++
 include/media/media-request.h | 193 ++++++++++++++++
 5 files changed, 643 insertions(+), 1 deletion(-)
 create mode 100644 drivers/media/media-request.c
 create mode 100644 include/media/media-request.h

diff --git a/drivers/media/Makefile b/drivers/media/Makefile
index 594b462ddf0e..985d35ec6b29 100644
--- a/drivers/media/Makefile
+++ b/drivers/media/Makefile
@@ -3,7 +3,8 @@
 # Makefile for the kernel multimedia device drivers.
 #
 
-media-objs	:= media-device.o media-devnode.o media-entity.o
+media-objs	:= media-device.o media-devnode.o media-entity.o \
+		   media-request.o
 
 #
 # I2C drivers should come before other drivers, otherwise they'll fail
diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
index 35e81f7c0d2f..25d7e2a3ee84 100644
--- a/drivers/media/media-device.c
+++ b/drivers/media/media-device.c
@@ -32,6 +32,7 @@
 #include <media/media-device.h>
 #include <media/media-devnode.h>
 #include <media/media-entity.h>
+#include <media/media-request.h>
 
 #ifdef CONFIG_MEDIA_CONTROLLER
 
@@ -366,6 +367,15 @@ static long media_device_get_topology(struct media_device *mdev,
 	return ret;
 }
 
+static long media_device_request_alloc(struct media_device *mdev,
+				       struct media_request_alloc *alloc)
+{
+	if (!mdev->ops || !mdev->ops->req_validate || !mdev->ops->req_queue)
+		return -ENOTTY;
+
+	return media_request_alloc(mdev, alloc);
+}
+
 static long copy_arg_from_user(void *karg, void __user *uarg, unsigned int cmd)
 {
 	/* All media IOCTLs are _IOWR() */
@@ -414,6 +424,7 @@ static const struct media_ioctl_info ioctl_info[] = {
 	MEDIA_IOC(ENUM_LINKS, media_device_enum_links, MEDIA_IOC_FL_GRAPH_MUTEX),
 	MEDIA_IOC(SETUP_LINK, media_device_setup_link, MEDIA_IOC_FL_GRAPH_MUTEX),
 	MEDIA_IOC(G_TOPOLOGY, media_device_get_topology, MEDIA_IOC_FL_GRAPH_MUTEX),
+	MEDIA_IOC(REQUEST_ALLOC, media_device_request_alloc, 0),
 };
 
 static long media_device_ioctl(struct file *filp, unsigned int cmd,
@@ -686,6 +697,8 @@ void media_device_init(struct media_device *mdev)
 	INIT_LIST_HEAD(&mdev->pads);
 	INIT_LIST_HEAD(&mdev->links);
 	INIT_LIST_HEAD(&mdev->entity_notify);
+
+	mutex_init(&mdev->req_queue_mutex);
 	mutex_init(&mdev->graph_mutex);
 	ida_init(&mdev->entity_internal_idx);
 
diff --git a/drivers/media/media-request.c b/drivers/media/media-request.c
new file mode 100644
index 000000000000..22881d5700c8
--- /dev/null
+++ b/drivers/media/media-request.c
@@ -0,0 +1,418 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Media device request objects
+ *
+ * Copyright (C) 2018 Intel Corporation
+ * Copyright (C) 2018 Google, Inc.
+ *
+ * Author: Sakari Ailus <sakari.ailus@linux.intel.com>
+ */
+
+#include <linux/anon_inodes.h>
+#include <linux/file.h>
+
+#include <media/media-device.h>
+#include <media/media-request.h>
+
+static const char * const request_state[] = {
+	[MEDIA_REQUEST_STATE_IDLE]	 = "idle",
+	[MEDIA_REQUEST_STATE_VALIDATING] = "validating",
+	[MEDIA_REQUEST_STATE_QUEUED]	 = "queued",
+	[MEDIA_REQUEST_STATE_COMPLETE]	 = "complete",
+	[MEDIA_REQUEST_STATE_CLEANING]	 = "cleaning",
+};
+
+static const char *
+media_request_state_str(enum media_request_state state)
+{
+	if (WARN_ON(state >= ARRAY_SIZE(request_state)))
+		return "unknown";
+	return request_state[state];
+}
+
+static void media_request_clean(struct media_request *req)
+{
+	struct media_request_object *obj, *obj_safe;
+
+	WARN_ON(atomic_read(&req->state) != MEDIA_REQUEST_STATE_CLEANING);
+
+	list_for_each_entry_safe(obj, obj_safe, &req->objects, list) {
+		media_request_object_unbind(obj);
+		media_request_object_put(obj);
+	}
+
+	req->num_incomplete_objects = 0;
+	wake_up_interruptible_all(&req->poll_wait);
+}
+
+static void media_request_release(struct kref *kref)
+{
+	struct media_request *req =
+		container_of(kref, struct media_request, kref);
+	struct media_device *mdev = req->mdev;
+
+	dev_dbg(mdev->dev, "request: release %s\n", req->debug_str);
+
+	atomic_set(&req->state, MEDIA_REQUEST_STATE_CLEANING);
+
+	media_request_clean(req);
+
+	if (mdev->ops->req_free)
+		mdev->ops->req_free(req);
+	else
+		kfree(req);
+}
+
+void media_request_put(struct media_request *req)
+{
+	kref_put(&req->kref, media_request_release);
+}
+EXPORT_SYMBOL_GPL(media_request_put);
+
+void media_request_cancel(struct media_request *req)
+{
+	struct media_request_object *obj, *obj_safe;
+
+	/*
+	 * This is serialized with the req_queue_mutex and streaming
+	 * has stopped, so there is no need to take the spinlock here.
+	 */
+	WARN_ON_ONCE(!mutex_is_locked(&req->mdev->req_queue_mutex));
+	if (atomic_read(&req->state) != MEDIA_REQUEST_STATE_QUEUED)
+		return;
+
+	list_for_each_entry_safe(obj, obj_safe, &req->objects, list)
+		if (obj->ops->cancel)
+			obj->ops->cancel(obj);
+}
+EXPORT_SYMBOL_GPL(media_request_cancel);
+
+static int media_request_close(struct inode *inode, struct file *filp)
+{
+	struct media_request *req = filp->private_data;
+
+	media_request_put(req);
+	return 0;
+}
+
+static unsigned int media_request_poll(struct file *filp,
+				       struct poll_table_struct *wait)
+{
+	struct media_request *req = filp->private_data;
+	unsigned long flags;
+	unsigned int ret = 0;
+	enum media_request_state state;
+
+	if (!(poll_requested_events(wait) & POLLPRI))
+		return 0;
+
+	spin_lock_irqsave(&req->lock, flags);
+	state = atomic_read(&req->state);
+
+	if (state == MEDIA_REQUEST_STATE_COMPLETE) {
+		ret = POLLPRI;
+		goto unlock;
+	}
+	if (state == MEDIA_REQUEST_STATE_IDLE) {
+		ret = POLLERR;
+		goto unlock;
+	}
+
+	poll_wait(filp, &req->poll_wait, wait);
+unlock:
+	spin_unlock_irqrestore(&req->lock, flags);
+	return ret;
+}
+
+static long media_request_ioctl_queue(struct media_request *req)
+{
+	struct media_device *mdev = req->mdev;
+	enum media_request_state state;
+	unsigned long flags;
+	int ret = 0;
+
+	dev_dbg(mdev->dev, "request: queue %s\n", req->debug_str);
+
+	/*
+	 * Ensure the request that is validated will be the one that gets queued
+	 * next by serialising the queueing process. This mutex is also used
+	 * to serialize with canceling a vb2 queue and with setting values such
+	 * as controls in a request.
+	 */
+	mutex_lock(&mdev->req_queue_mutex);
+
+	spin_lock_irqsave(&req->lock, flags);
+	state = atomic_cmpxchg(&req->state, MEDIA_REQUEST_STATE_IDLE,
+			       MEDIA_REQUEST_STATE_VALIDATING);
+	spin_unlock_irqrestore(&req->lock, flags);
+	if (state != MEDIA_REQUEST_STATE_IDLE) {
+		dev_dbg(mdev->dev,
+			"request: unable to queue %s, request in state %s\n",
+			req->debug_str, media_request_state_str(state));
+		mutex_unlock(&mdev->req_queue_mutex);
+		return -EBUSY;
+	}
+
+	ret = mdev->ops->req_validate(req);
+
+	/*
+	 * If the req_validate was successful, then we mark the state as QUEUED
+	 * and call req_queue. The reason we set the state first is that this
+	 * allows req_queue to unbind or complete the queued objects in case
+	 * they are immediately 'consumed'. State changes from QUEUED to another
+	 * state can only happen if either the driver changes the state or if
+	 * the user cancels the vb2 queue. The driver can only change the state
+	 * after each object is queued through the req_queue op (and note that
+	 * that op cannot fail), so setting the state to QUEUED up front is
+	 * safe.
+	 *
+	 * The other reason for changing the state is if the vb2 queue is
+	 * canceled, and that uses the req_queue_mutex which is still locked
+	 * while req_queue is called, so that's safe as well.
+	 */
+	atomic_set(&req->state,
+		   ret ? MEDIA_REQUEST_STATE_IDLE : MEDIA_REQUEST_STATE_QUEUED);
+
+	if (!ret)
+		mdev->ops->req_queue(req);
+
+	mutex_unlock(&mdev->req_queue_mutex);
+
+	if (ret) {
+		dev_dbg(mdev->dev, "request: can't queue %s (%d)\n",
+			req->debug_str, ret);
+	} else {
+		media_request_get(req);
+	}
+
+	return ret;
+}
+
+static long media_request_ioctl_reinit(struct media_request *req)
+{
+	struct media_device *mdev = req->mdev;
+	unsigned long flags;
+
+	spin_lock_irqsave(&req->lock, flags);
+	if (atomic_read(&req->state) != MEDIA_REQUEST_STATE_IDLE &&
+	    atomic_read(&req->state) != MEDIA_REQUEST_STATE_COMPLETE) {
+		dev_dbg(mdev->dev,
+			"request: %s not in idle or complete state, cannot reinit\n",
+			req->debug_str);
+		spin_unlock_irqrestore(&req->lock, flags);
+		return -EBUSY;
+	}
+	atomic_set(&req->state, MEDIA_REQUEST_STATE_CLEANING);
+	spin_unlock_irqrestore(&req->lock, flags);
+
+	media_request_clean(req);
+
+	atomic_set(&req->state, MEDIA_REQUEST_STATE_IDLE);
+
+	return 0;
+}
+
+static long media_request_ioctl(struct file *filp, unsigned int cmd,
+				unsigned long arg)
+{
+	struct media_request *req = filp->private_data;
+
+	switch (cmd) {
+	case MEDIA_REQUEST_IOC_QUEUE:
+		return media_request_ioctl_queue(req);
+	case MEDIA_REQUEST_IOC_REINIT:
+		return media_request_ioctl_reinit(req);
+	default:
+		return -ENOIOCTLCMD;
+	}
+}
+
+static const struct file_operations request_fops = {
+	.owner = THIS_MODULE,
+	.poll = media_request_poll,
+	.unlocked_ioctl = media_request_ioctl,
+	.release = media_request_close,
+};
+
+int media_request_alloc(struct media_device *mdev,
+			struct media_request_alloc *alloc)
+{
+	struct media_request *req;
+	struct file *filp;
+	char comm[TASK_COMM_LEN];
+	int fd;
+	int ret;
+
+	/* Either both are NULL or both are non-NULL */
+	if (WARN_ON(!mdev->ops->req_alloc ^ !mdev->ops->req_free))
+		return -ENOMEM;
+
+	fd = get_unused_fd_flags(O_CLOEXEC);
+	if (fd < 0)
+		return fd;
+
+	filp = anon_inode_getfile("request", &request_fops, NULL, O_CLOEXEC);
+	if (IS_ERR(filp)) {
+		ret = PTR_ERR(filp);
+		goto err_put_fd;
+	}
+
+	if (mdev->ops->req_alloc)
+		req = mdev->ops->req_alloc(mdev);
+	else
+		req = kzalloc(sizeof(*req), GFP_KERNEL);
+	if (!req) {
+		ret = -ENOMEM;
+		goto err_fput;
+	}
+
+	filp->private_data = req;
+	req->mdev = mdev;
+	atomic_set(&req->state, MEDIA_REQUEST_STATE_IDLE);
+	req->num_incomplete_objects = 0;
+	kref_init(&req->kref);
+	INIT_LIST_HEAD(&req->objects);
+	spin_lock_init(&req->lock);
+	init_waitqueue_head(&req->poll_wait);
+
+	alloc->fd = fd;
+
+	get_task_comm(comm, current);
+	snprintf(req->debug_str, sizeof(req->debug_str), "%s:%d",
+		 comm, fd);
+	dev_dbg(mdev->dev, "request: allocated %s\n", req->debug_str);
+
+	fd_install(fd, filp);
+
+	return 0;
+
+err_fput:
+	fput(filp);
+
+err_put_fd:
+	put_unused_fd(fd);
+
+	return ret;
+}
+
+static void media_request_object_release(struct kref *kref)
+{
+	struct media_request_object *obj =
+		container_of(kref, struct media_request_object, kref);
+	struct media_request *req = obj->req;
+
+	if (req)
+		media_request_object_unbind(obj);
+	obj->ops->release(obj);
+}
+
+void media_request_object_put(struct media_request_object *obj)
+{
+	kref_put(&obj->kref, media_request_object_release);
+}
+EXPORT_SYMBOL_GPL(media_request_object_put);
+
+void media_request_object_init(struct media_request_object *obj)
+{
+	obj->ops = NULL;
+	obj->req = NULL;
+	obj->priv = NULL;
+	obj->completed = false;
+	INIT_LIST_HEAD(&obj->list);
+	kref_init(&obj->kref);
+}
+EXPORT_SYMBOL_GPL(media_request_object_init);
+
+int media_request_object_bind(struct media_request *req,
+			      const struct media_request_object_ops *ops,
+			      void *priv,
+			      struct media_request_object *obj)
+{
+	unsigned long flags;
+	int ret = -EBUSY;
+
+	if (WARN_ON(!ops->release || !ops->cancel))
+		return -EPERM;
+
+	obj->req = req;
+	obj->ops = ops;
+	obj->priv = priv;
+	spin_lock_irqsave(&req->lock, flags);
+	if (WARN_ON(atomic_read(&req->state) != MEDIA_REQUEST_STATE_IDLE))
+		goto unlock;
+	list_add_tail(&obj->list, &req->objects);
+	req->num_incomplete_objects++;
+	ret = 0;
+unlock:
+	spin_unlock_irqrestore(&req->lock, flags);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(media_request_object_bind);
+
+void media_request_object_unbind(struct media_request_object *obj)
+{
+	struct media_request *req = obj->req;
+	enum media_request_state state;
+	unsigned long flags;
+	bool completed = false;
+
+	if (WARN_ON(!req))
+		return;
+
+	spin_lock_irqsave(&req->lock, flags);
+	list_del(&obj->list);
+	obj->req = NULL;
+
+	state = atomic_read(&req->state);
+
+	if (state == MEDIA_REQUEST_STATE_COMPLETE ||
+	    state == MEDIA_REQUEST_STATE_CLEANING)
+		goto unlock;
+
+	if (WARN_ON(state == MEDIA_REQUEST_STATE_VALIDATING))
+		goto unlock;
+
+	if (WARN_ON(!req->num_incomplete_objects))
+		goto unlock;
+
+	req->num_incomplete_objects--;
+	if (state == MEDIA_REQUEST_STATE_QUEUED &&
+	    !req->num_incomplete_objects) {
+		atomic_set(&req->state, MEDIA_REQUEST_STATE_COMPLETE);
+		completed = true;
+		wake_up_interruptible_all(&req->poll_wait);
+	}
+unlock:
+	spin_unlock_irqrestore(&req->lock, flags);
+	if (obj->ops->unbind)
+		obj->ops->unbind(obj);
+	if (completed)
+		media_request_put(req);
+}
+EXPORT_SYMBOL_GPL(media_request_object_unbind);
+
+void media_request_object_complete(struct media_request_object *obj)
+{
+	struct media_request *req = obj->req;
+	unsigned long flags;
+	bool completed = false;
+
+	spin_lock_irqsave(&req->lock, flags);
+	if (obj->completed)
+		goto unlock;
+	obj->completed = true;
+	if (WARN_ON(!req->num_incomplete_objects) ||
+	    WARN_ON(atomic_read(&req->state) != MEDIA_REQUEST_STATE_QUEUED))
+		goto unlock;
+
+	if (!--req->num_incomplete_objects) {
+		atomic_set(&req->state, MEDIA_REQUEST_STATE_COMPLETE);
+		wake_up_interruptible_all(&req->poll_wait);
+		completed = true;
+	}
+unlock:
+	spin_unlock_irqrestore(&req->lock, flags);
+	if (completed)
+		media_request_put(req);
+}
+EXPORT_SYMBOL_GPL(media_request_object_complete);
diff --git a/include/media/media-device.h b/include/media/media-device.h
index bcc6ec434f1f..ae846208be51 100644
--- a/include/media/media-device.h
+++ b/include/media/media-device.h
@@ -27,6 +27,7 @@
 
 struct ida;
 struct device;
+struct media_device;
 
 /**
  * struct media_entity_notify - Media Entity Notify
@@ -50,10 +51,22 @@ struct media_entity_notify {
  * struct media_device_ops - Media device operations
  * @link_notify: Link state change notification callback. This callback is
  *		 called with the graph_mutex held.
+ * @req_alloc: Allocate a request
+ * @req_free: Free a request
+ * @req_validate: Validate a request, but do not queue yet
+ * @req_queue: Queue a validated request, cannot fail. If something goes
+ *	       wrong when queueing this request then it should be marked
+ *	       as such internally in the driver and any related buffers
+ *	       will eventually return to userspace with V4L2_BUF_FLAG_ERROR
+ *	       set.
  */
 struct media_device_ops {
 	int (*link_notify)(struct media_link *link, u32 flags,
 			   unsigned int notification);
+	struct media_request *(*req_alloc)(struct media_device *mdev);
+	void (*req_free)(struct media_request *req);
+	int (*req_validate)(struct media_request *req);
+	void (*req_queue)(struct media_request *req);
 };
 
 /**
@@ -88,6 +101,8 @@ struct media_device_ops {
  * @disable_source: Disable Source Handler function pointer
  *
  * @ops:	Operation handler callbacks
+ * @req_queue_mutex: Serialise the MEDIA_REQUEST_IOC_QUEUE ioctl w.r.t. this
+ *		     media device.
  *
  * This structure represents an abstract high-level media device. It allows easy
  * access to entities and provides basic media device-level support. The
@@ -158,6 +173,8 @@ struct media_device {
 	void (*disable_source)(struct media_entity *entity);
 
 	const struct media_device_ops *ops;
+
+	struct mutex req_queue_mutex;
 };
 
 /* We don't need to include pci.h or usb.h here */
diff --git a/include/media/media-request.h b/include/media/media-request.h
new file mode 100644
index 000000000000..9051dfbc7d30
--- /dev/null
+++ b/include/media/media-request.h
@@ -0,0 +1,193 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Media device request objects
+ *
+ * Copyright (C) 2018 Intel Corporation
+ *
+ * Author: Sakari Ailus <sakari.ailus@linux.intel.com>
+ */
+
+#ifndef MEDIA_REQUEST_H
+#define MEDIA_REQUEST_H
+
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/atomic.h>
+
+#include <media/media-device.h>
+
+/**
+ * enum media_request_state - media request state
+ *
+ * @MEDIA_REQUEST_STATE_IDLE:		Idle
+ * @MEDIA_REQUEST_STATE_VALIDATING:	Validating the request, no state changes
+ *					allowed
+ * @MEDIA_REQUEST_STATE_QUEUED:		Queued
+ * @MEDIA_REQUEST_STATE_COMPLETE:	Completed, the request is done
+ * @MEDIA_REQUEST_STATE_CLEANING:	Cleaning, the request is being re-inited
+ */
+enum media_request_state {
+	MEDIA_REQUEST_STATE_IDLE,
+	MEDIA_REQUEST_STATE_VALIDATING,
+	MEDIA_REQUEST_STATE_QUEUED,
+	MEDIA_REQUEST_STATE_COMPLETE,
+	MEDIA_REQUEST_STATE_CLEANING,
+};
+
+struct media_request_object;
+
+/**
+ * struct media_request - Media device request
+ * @mdev: Media device this request belongs to
+ * @kref: Reference count
+ * @debug_str: Prefix for debug messages (process name:fd)
+ * @state: The state of the request
+ * @objects: List of @struct media_request_object request objects
+ * @num_objects: The number of objects in the request
+ * @num_incompleted_objects: The number of incomplete objects in the request
+ * @poll_wait: Wait queue for poll
+ * @lock: Serializes access to this struct
+ */
+struct media_request {
+	struct media_device *mdev;
+	struct kref kref;
+	char debug_str[TASK_COMM_LEN + 11];
+	atomic_t state;
+	struct list_head objects;
+	unsigned int num_incomplete_objects;
+	struct wait_queue_head poll_wait;
+	spinlock_t lock;
+};
+
+#ifdef CONFIG_MEDIA_CONTROLLER
+
+static inline void media_request_get(struct media_request *req)
+{
+	kref_get(&req->kref);
+}
+
+void media_request_put(struct media_request *req);
+void media_request_cancel(struct media_request *req);
+
+int media_request_alloc(struct media_device *mdev,
+			struct media_request_alloc *alloc);
+#else
+static inline void media_request_get(struct media_request *req)
+{
+}
+
+static inline void media_request_put(struct media_request *req)
+{
+}
+
+static inline void media_request_cancel(struct media_request *req)
+{
+}
+
+#endif
+
+struct media_request_object_ops {
+	int (*prepare)(struct media_request_object *object);
+	void (*unprepare)(struct media_request_object *object);
+	void (*queue)(struct media_request_object *object);
+	void (*unbind)(struct media_request_object *object);
+	void (*cancel)(struct media_request_object *object);
+	void (*release)(struct media_request_object *object);
+};
+
+/**
+ * struct media_request_object - An opaque object that belongs to a media
+ *				 request
+ *
+ * @ops: object's operations
+ * @priv: object's priv pointer
+ * @req: the request this object belongs to (can be NULL)
+ * @list: List entry of the object for @struct media_request
+ * @kref: Reference count of the object, acquire before releasing req->lock
+ * @completed: If true, then this object was completed.
+ *
+ * An object related to the request. This struct is embedded in the
+ * larger object data.
+ */
+struct media_request_object {
+	const struct media_request_object_ops *ops;
+	void *priv;
+	struct media_request *req;
+	struct list_head list;
+	struct kref kref;
+	bool completed;
+};
+
+#ifdef CONFIG_MEDIA_CONTROLLER
+static inline void media_request_object_get(struct media_request_object *obj)
+{
+	kref_get(&obj->kref);
+}
+
+/**
+ * media_request_object_put - Put a media request object
+ *
+ * @obj: The object
+ *
+ * Put a media request object. Once all references are gone, the
+ * object's memory is released.
+ */
+void media_request_object_put(struct media_request_object *obj);
+
+/**
+ * media_request_object_init - Initialise a media request object
+ *
+ * Initialise a media request object. The object will be released using the
+ * release callback of the ops once it has no references (this function
+ * initialises references to one).
+ */
+void media_request_object_init(struct media_request_object *obj);
+
+/**
+ * media_request_object_bind - Bind a media request object to a request
+ */
+int media_request_object_bind(struct media_request *req,
+			      const struct media_request_object_ops *ops,
+			      void *priv,
+			      struct media_request_object *obj);
+
+void media_request_object_unbind(struct media_request_object *obj);
+
+/**
+ * media_request_object_complete - Mark the media request object as complete
+ */
+void media_request_object_complete(struct media_request_object *obj);
+#else
+static inline void media_request_object_get(struct media_request_object *obj)
+{
+}
+
+static inline void media_request_object_put(struct media_request_object *obj)
+{
+}
+
+static inline void media_request_object_init(struct media_request_object *obj)
+{
+	obj->ops = NULL;
+	obj->req = NULL;
+}
+
+static inline int media_request_object_bind(struct media_request *req,
+			       const struct media_request_object_ops *ops,
+			       void *priv,
+			       struct media_request_object *obj)
+{
+	return 0;
+}
+
+static inline void media_request_object_unbind(struct media_request_object *obj)
+{
+}
+
+static inline void media_request_object_complete(struct media_request_object *obj)
+{
+}
+#endif
+
+#endif
-- 
2.17.0

[RFCv12 PATCH 04/29] v4l2-dev: lock req_queue_mutex

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/v4l2-dev.c | 37 +++++++++++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c
index 1d0b2208e8fb..3368bd5537a7 100644
--- a/drivers/media/v4l2-core/v4l2-dev.c
+++ b/drivers/media/v4l2-core/v4l2-dev.c
@@ -353,13 +353,36 @@ static long v4l2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 
 	if (vdev->fops->unlocked_ioctl) {
 		struct mutex *lock = v4l2_ioctl_get_lock(vdev, cmd);
+		struct mutex *queue_lock = NULL;
 
-		if (lock && mutex_lock_interruptible(lock))
+		/*
+		 * We need to serialize streamon/off with queuing new requests.
+		 * These ioctls may trigger the cancellation of a streaming
+		 * operation, and that should not be mixed with queuing a new
+		 * request at the same time.
+		 *
+		 * Also TRY/S_EXT_CTRLS needs this lock to correctly serialize
+		 * with MEDIA_REQUEST_IOC_QUEUE.
+		 */
+		if (vdev->v4l2_dev->mdev &&
+		    (cmd == VIDIOC_STREAMON || cmd == VIDIOC_STREAMOFF ||
+		     cmd == VIDIOC_S_EXT_CTRLS || cmd == VIDIOC_TRY_EXT_CTRLS))
+			queue_lock = &vdev->v4l2_dev->mdev->req_queue_mutex;
+
+		if (queue_lock && mutex_lock_interruptible(queue_lock))
+			return -ERESTARTSYS;
+
+		if (lock && mutex_lock_interruptible(lock)) {
+			if (queue_lock)
+				mutex_unlock(queue_lock);
 			return -ERESTARTSYS;
+		}
 		if (video_is_registered(vdev))
 			ret = vdev->fops->unlocked_ioctl(filp, cmd, arg);
 		if (lock)
 			mutex_unlock(lock);
+		if (queue_lock)
+			mutex_unlock(queue_lock);
 	} else
 		ret = -ENOTTY;
 
@@ -442,8 +465,20 @@ static int v4l2_release(struct inode *inode, struct file *filp)
 	struct video_device *vdev = video_devdata(filp);
 	int ret = 0;
 
+	/*
+	 * We need to serialize the release() with queuing new requests.
+	 * The release() may trigger the cancellation of a streaming
+	 * operation, and that should not be mixed with queuing a new
+	 * request at the same time.
+	 */
+	if (vdev->v4l2_dev->mdev)
+		mutex_lock(&vdev->v4l2_dev->mdev->req_queue_mutex);
+
 	if (vdev->fops->release)
 		ret = vdev->fops->release(filp);
+
+	if (vdev->v4l2_dev->mdev)
+		mutex_unlock(&vdev->v4l2_dev->mdev->req_queue_mutex);
 	if (vdev->dev_debug & V4L2_DEV_DEBUG_FOP)
 		printk(KERN_DEBUG "%s: release\n",
 			video_device_node_name(vdev));
-- 
2.17.0

[RFCv12 PATCH 05/29] media-request: add media_request_find

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

Add media_request_find() to find a request based on the file
descriptor.

The caller has to call media_request_put() for the returned
request since this function increments the refcount.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/media-request.c | 44 +++++++++++++++++++++++++++++++++++
 include/media/media-request.h | 10 ++++++++
 2 files changed, 54 insertions(+)

diff --git a/drivers/media/media-request.c b/drivers/media/media-request.c
index 22881d5700c8..a186db290d51 100644
--- a/drivers/media/media-request.c
+++ b/drivers/media/media-request.c
@@ -234,6 +234,50 @@ static const struct file_operations request_fops = {
 	.release = media_request_close,
 };
 
+/**
+ * media_request_find - Find a request based on the file descriptor
+ * @mdev: The media device
+ * @request_fd: The request file handle
+ *
+ * Find and return the request associated with the given file descriptor, or
+ * an error if no such request exists.
+ *
+ * When the function returns a request it increases its reference count. The
+ * caller is responsible for releasing the reference by calling
+ * media_request_put() on the request.
+ */
+struct media_request *
+media_request_find(struct media_device *mdev, int request_fd)
+{
+	struct file *filp;
+	struct media_request *req;
+
+	if (!mdev || !mdev->ops ||
+	    !mdev->ops->req_validate || !mdev->ops->req_queue)
+		return ERR_PTR(-EPERM);
+
+	filp = fget(request_fd);
+	if (!filp)
+		return ERR_PTR(-ENOENT);
+
+	if (filp->f_op != &request_fops)
+		goto err_fput;
+	req = filp->private_data;
+	if (req->mdev != mdev)
+		goto err_fput;
+
+	media_request_get(req);
+	fput(filp);
+
+	return req;
+
+err_fput:
+	fput(filp);
+
+	return ERR_PTR(-ENOENT);
+}
+EXPORT_SYMBOL_GPL(media_request_find);
+
 int media_request_alloc(struct media_device *mdev,
 			struct media_request_alloc *alloc)
 {
diff --git a/include/media/media-request.h b/include/media/media-request.h
index 9051dfbc7d30..ce62fe74ebd6 100644
--- a/include/media/media-request.h
+++ b/include/media/media-request.h
@@ -70,6 +70,9 @@ static inline void media_request_get(struct media_request *req)
 void media_request_put(struct media_request *req);
 void media_request_cancel(struct media_request *req);
 
+struct media_request *
+media_request_find(struct media_device *mdev, int request_fd);
+
 int media_request_alloc(struct media_device *mdev,
 			struct media_request_alloc *alloc);
 #else
@@ -85,6 +88,12 @@ static inline void media_request_cancel(struct media_request *req)
 {
 }
 
+static inline struct media_request *
+media_request_find(struct media_device *mdev, int request_fd)
+{
+	return ERR_PTR(-ENOENT);
+}
+
 #endif
 
 struct media_request_object_ops {
@@ -188,6 +197,7 @@ static inline void media_request_object_unbind(struct media_request_object *obj)
 static inline void media_request_object_complete(struct media_request_object *obj)
 {
 }
+
 #endif
 
 #endif
-- 
2.17.0

[RFCv12 PATCH 06/29] media-request: add media_request_object_find

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

Add media_request_object_find to find a request object inside a
request based on ops and/or priv values.

Objects of the same type (vb2 buffer, control handler) will have
the same ops value. And objects that refer to the same 'parent'
object (e.g. the v4l2_ctrl_handler that has the current driver
state) will have the same priv value.

The caller has to call media_request_object_put() for the returned
object since this function increments the refcount.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/media-request.c | 25 +++++++++++++++++++++++++
 include/media/media-request.h | 24 ++++++++++++++++++++++++
 2 files changed, 49 insertions(+)

diff --git a/drivers/media/media-request.c b/drivers/media/media-request.c
index a186db290d51..9815fb6445dc 100644
--- a/drivers/media/media-request.c
+++ b/drivers/media/media-request.c
@@ -350,6 +350,31 @@ static void media_request_object_release(struct kref *kref)
 	obj->ops->release(obj);
 }
 
+struct media_request_object *
+media_request_object_find(struct media_request *req,
+			  const struct media_request_object_ops *ops,
+			  void *priv)
+{
+	struct media_request_object *obj;
+	struct media_request_object *found = NULL;
+	unsigned long flags;
+
+	if (WARN_ON(!ops || !priv))
+		return NULL;
+
+	spin_lock_irqsave(&req->lock, flags);
+	list_for_each_entry(obj, &req->objects, list) {
+		if (obj->ops == ops && obj->priv == priv) {
+			media_request_object_get(obj);
+			found = obj;
+			break;
+		}
+	}
+	spin_unlock_irqrestore(&req->lock, flags);
+	return found;
+}
+EXPORT_SYMBOL_GPL(media_request_object_find);
+
 void media_request_object_put(struct media_request_object *obj)
 {
 	kref_put(&obj->kref, media_request_object_release);
diff --git a/include/media/media-request.h b/include/media/media-request.h
index ce62fe74ebd6..6ecc89fcf4a2 100644
--- a/include/media/media-request.h
+++ b/include/media/media-request.h
@@ -144,6 +144,22 @@ static inline void media_request_object_get(struct media_request_object *obj)
  */
 void media_request_object_put(struct media_request_object *obj);
 
+/**
+ * media_request_object_find - Find an object in a request
+ *
+ * @ops: Find an object with this ops value
+ * @priv: Find an object with this priv value
+ *
+ * Both @ops and @priv must be non-NULL.
+ *
+ * Returns NULL if not found or the object pointer (the refcount is
+ * increased in that case).
+ */
+struct media_request_object *
+media_request_object_find(struct media_request *req,
+			  const struct media_request_object_ops *ops,
+			  void *priv);
+
 /**
  * media_request_object_init - Initialise a media request object
  *
@@ -176,6 +192,14 @@ static inline void media_request_object_put(struct media_request_object *obj)
 {
 }
 
+static inline struct media_request_object *
+media_request_object_find(struct media_request *req,
+			  const struct media_request_object_ops *ops,
+			  void *priv)
+{
+	return NULL;
+}
+
 static inline void media_request_object_init(struct media_request_object *obj)
 {
 	obj->ops = NULL;
-- 
2.17.0

[RFCv12 PATCH 07/29] videodev2.h: add request_fd field to v4l2_ext_controls

[Hans Verkuil]

From: Alexandre Courbot <acourbot@chromium.org>

If which is V4L2_CTRL_WHICH_REQUEST_VAL, then the request_fd field can be
used to specify a request for the G/S/TRY_EXT_CTRLS ioctls.

Signed-off-by: Alexandre Courbot <acourbot@chromium.org>
---
 drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 5 ++++-
 drivers/media/v4l2-core/v4l2-ioctl.c          | 6 +++---
 include/uapi/linux/videodev2.h                | 4 +++-
 3 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
index 6481212fda77..dcce86c1fe40 100644
--- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
+++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
@@ -834,7 +834,8 @@ struct v4l2_ext_controls32 {
 	__u32 which;
 	__u32 count;
 	__u32 error_idx;
-	__u32 reserved[2];
+	__s32 request_fd;
+	__u32 reserved[1];
 	compat_caddr_t controls; /* actually struct v4l2_ext_control32 * */
 };
 
@@ -909,6 +910,7 @@ static int get_v4l2_ext_controls32(struct file *file,
 	    get_user(count, &p32->count) ||
 	    put_user(count, &p64->count) ||
 	    assign_in_user(&p64->error_idx, &p32->error_idx) ||
+	    assign_in_user(&p64->request_fd, &p32->request_fd) ||
 	    copy_in_user(p64->reserved, p32->reserved, sizeof(p64->reserved)))
 		return -EFAULT;
 
@@ -974,6 +976,7 @@ static int put_v4l2_ext_controls32(struct file *file,
 	    get_user(count, &p64->count) ||
 	    put_user(count, &p32->count) ||
 	    assign_in_user(&p32->error_idx, &p64->error_idx) ||
+	    assign_in_user(&p32->request_fd, &p64->request_fd) ||
 	    copy_in_user(p32->reserved, p64->reserved, sizeof(p32->reserved)) ||
 	    get_user(kcontrols, &p64->controls))
 		return -EFAULT;
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index f48c505550e0..9ce23e23c5bf 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -553,8 +553,8 @@ static void v4l_print_ext_controls(const void *arg, bool write_only)
 	const struct v4l2_ext_controls *p = arg;
 	int i;
 
-	pr_cont("which=0x%x, count=%d, error_idx=%d",
-			p->which, p->count, p->error_idx);
+	pr_cont("which=0x%x, count=%d, error_idx=%d, request_fd=%d",
+			p->which, p->count, p->error_idx, p->request_fd);
 	for (i = 0; i < p->count; i++) {
 		if (!p->controls[i].size)
 			pr_cont(", id/val=0x%x/0x%x",
@@ -870,7 +870,7 @@ static int check_ext_ctrls(struct v4l2_ext_controls *c, int allow_priv)
 	__u32 i;
 
 	/* zero the reserved fields */
-	c->reserved[0] = c->reserved[1] = 0;
+	c->reserved[0] = 0;
 	for (i = 0; i < c->count; i++)
 		c->controls[i].reserved2[0] = 0;
 
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 600877be5c22..16b53b82496c 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -1592,7 +1592,8 @@ struct v4l2_ext_controls {
 	};
 	__u32 count;
 	__u32 error_idx;
-	__u32 reserved[2];
+	__s32 request_fd;
+	__u32 reserved[1];
 	struct v4l2_ext_control *controls;
 };
 
@@ -1605,6 +1606,7 @@ struct v4l2_ext_controls {
 #define V4L2_CTRL_MAX_DIMS	  (4)
 #define V4L2_CTRL_WHICH_CUR_VAL   0
 #define V4L2_CTRL_WHICH_DEF_VAL   0x0f000000
+#define V4L2_CTRL_WHICH_REQUEST_VAL 0x0f010000
 
 enum v4l2_ctrl_type {
 	V4L2_CTRL_TYPE_INTEGER	     = 1,
-- 
2.17.0

[RFCv12 PATCH 08/29] v4l2-ctrls: v4l2_ctrl_add_handler: add from_other_dev

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

Add a 'bool from_other_dev' argument: set to true if the two
handlers refer to different devices (e.g. it is true when
inheriting controls from a subdev into a main v4l2 bridge
driver).

This will be used later when implementing support for the
request API since we need to skip such controls.

TODO: check drivers/staging/media/imx/imx-media-fim.c change.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Alexandre Courbot <acourbot@chromium.org>
---
 drivers/media/dvb-frontends/rtl2832_sdr.c     |  5 +-
 drivers/media/pci/bt8xx/bttv-driver.c         |  2 +-
 drivers/media/pci/cx23885/cx23885-417.c       |  2 +-
 drivers/media/pci/cx88/cx88-blackbird.c       |  2 +-
 drivers/media/pci/cx88/cx88-video.c           |  2 +-
 drivers/media/pci/saa7134/saa7134-empress.c   |  4 +-
 drivers/media/pci/saa7134/saa7134-video.c     |  2 +-
 .../media/platform/exynos4-is/fimc-capture.c  |  2 +-
 drivers/media/platform/rcar-vin/rcar-v4l2.c   |  3 +-
 drivers/media/platform/rcar_drif.c            |  2 +-
 .../media/platform/soc_camera/soc_camera.c    |  3 +-
 drivers/media/platform/vivid/vivid-ctrls.c    | 46 +++++++++----------
 drivers/media/usb/cx231xx/cx231xx-417.c       |  2 +-
 drivers/media/usb/cx231xx/cx231xx-video.c     |  4 +-
 drivers/media/usb/msi2500/msi2500.c           |  2 +-
 drivers/media/usb/tm6000/tm6000-video.c       |  2 +-
 drivers/media/v4l2-core/v4l2-ctrls.c          | 11 +++--
 drivers/media/v4l2-core/v4l2-device.c         |  3 +-
 drivers/staging/media/imx/imx-media-dev.c     |  2 +-
 drivers/staging/media/imx/imx-media-fim.c     |  2 +-
 include/media/v4l2-ctrls.h                    |  8 +++-
 21 files changed, 62 insertions(+), 49 deletions(-)

diff --git a/drivers/media/dvb-frontends/rtl2832_sdr.c b/drivers/media/dvb-frontends/rtl2832_sdr.c
index c6e78d870ccd..6064d28224e8 100644
--- a/drivers/media/dvb-frontends/rtl2832_sdr.c
+++ b/drivers/media/dvb-frontends/rtl2832_sdr.c
@@ -1394,7 +1394,8 @@ static int rtl2832_sdr_probe(struct platform_device *pdev)
 	case RTL2832_SDR_TUNER_E4000:
 		v4l2_ctrl_handler_init(&dev->hdl, 9);
 		if (subdev)
-			v4l2_ctrl_add_handler(&dev->hdl, subdev->ctrl_handler, NULL);
+			v4l2_ctrl_add_handler(&dev->hdl, subdev->ctrl_handler,
+					      NULL, true);
 		break;
 	case RTL2832_SDR_TUNER_R820T:
 	case RTL2832_SDR_TUNER_R828D:
@@ -1423,7 +1424,7 @@ static int rtl2832_sdr_probe(struct platform_device *pdev)
 		v4l2_ctrl_handler_init(&dev->hdl, 2);
 		if (subdev)
 			v4l2_ctrl_add_handler(&dev->hdl, subdev->ctrl_handler,
-					      NULL);
+					      NULL, true);
 		break;
 	default:
 		v4l2_ctrl_handler_init(&dev->hdl, 0);
diff --git a/drivers/media/pci/bt8xx/bttv-driver.c b/drivers/media/pci/bt8xx/bttv-driver.c
index 707f57a9f940..802c248c8d65 100644
--- a/drivers/media/pci/bt8xx/bttv-driver.c
+++ b/drivers/media/pci/bt8xx/bttv-driver.c
@@ -4211,7 +4211,7 @@ static int bttv_probe(struct pci_dev *dev, const struct pci_device_id *pci_id)
 	/* register video4linux + input */
 	if (!bttv_tvcards[btv->c.type].no_video) {
 		v4l2_ctrl_add_handler(&btv->radio_ctrl_handler, hdl,
-				v4l2_ctrl_radio_filter);
+				v4l2_ctrl_radio_filter, false);
 		if (btv->radio_ctrl_handler.error) {
 			result = btv->radio_ctrl_handler.error;
 			goto fail2;
diff --git a/drivers/media/pci/cx23885/cx23885-417.c b/drivers/media/pci/cx23885/cx23885-417.c
index a71f3c7569ce..762823871c78 100644
--- a/drivers/media/pci/cx23885/cx23885-417.c
+++ b/drivers/media/pci/cx23885/cx23885-417.c
@@ -1527,7 +1527,7 @@ int cx23885_417_register(struct cx23885_dev *dev)
 	dev->cxhdl.priv = dev;
 	dev->cxhdl.func = cx23885_api_func;
 	cx2341x_handler_set_50hz(&dev->cxhdl, tsport->height == 576);
-	v4l2_ctrl_add_handler(&dev->ctrl_handler, &dev->cxhdl.hdl, NULL);
+	v4l2_ctrl_add_handler(&dev->ctrl_handler, &dev->cxhdl.hdl, NULL, false);
 
 	/* Allocate and initialize V4L video device */
 	dev->v4l_device = cx23885_video_dev_alloc(tsport,
diff --git a/drivers/media/pci/cx88/cx88-blackbird.c b/drivers/media/pci/cx88/cx88-blackbird.c
index 0e0952e60795..39f69d89a663 100644
--- a/drivers/media/pci/cx88/cx88-blackbird.c
+++ b/drivers/media/pci/cx88/cx88-blackbird.c
@@ -1183,7 +1183,7 @@ static int cx8802_blackbird_probe(struct cx8802_driver *drv)
 	err = cx2341x_handler_init(&dev->cxhdl, 36);
 	if (err)
 		goto fail_core;
-	v4l2_ctrl_add_handler(&dev->cxhdl.hdl, &core->video_hdl, NULL);
+	v4l2_ctrl_add_handler(&dev->cxhdl.hdl, &core->video_hdl, NULL, false);
 
 	/* blackbird stuff */
 	pr_info("cx23416 based mpeg encoder (blackbird reference design)\n");
diff --git a/drivers/media/pci/cx88/cx88-video.c b/drivers/media/pci/cx88/cx88-video.c
index 9be682cdb644..e35bfa03a1e2 100644
--- a/drivers/media/pci/cx88/cx88-video.c
+++ b/drivers/media/pci/cx88/cx88-video.c
@@ -1378,7 +1378,7 @@ static int cx8800_initdev(struct pci_dev *pci_dev,
 		if (vc->id == V4L2_CID_CHROMA_AGC)
 			core->chroma_agc = vc;
 	}
-	v4l2_ctrl_add_handler(&core->video_hdl, &core->audio_hdl, NULL);
+	v4l2_ctrl_add_handler(&core->video_hdl, &core->audio_hdl, NULL, false);
 
 	/* load and configure helper modules */
 
diff --git a/drivers/media/pci/saa7134/saa7134-empress.c b/drivers/media/pci/saa7134/saa7134-empress.c
index 66acfd35ffc6..fc75ce00dbf8 100644
--- a/drivers/media/pci/saa7134/saa7134-empress.c
+++ b/drivers/media/pci/saa7134/saa7134-empress.c
@@ -265,9 +265,9 @@ static int empress_init(struct saa7134_dev *dev)
 		 "%s empress (%s)", dev->name,
 		 saa7134_boards[dev->board].name);
 	v4l2_ctrl_handler_init(hdl, 21);
-	v4l2_ctrl_add_handler(hdl, &dev->ctrl_handler, empress_ctrl_filter);
+	v4l2_ctrl_add_handler(hdl, &dev->ctrl_handler, empress_ctrl_filter, false);
 	if (dev->empress_sd)
-		v4l2_ctrl_add_handler(hdl, dev->empress_sd->ctrl_handler, NULL);
+		v4l2_ctrl_add_handler(hdl, dev->empress_sd->ctrl_handler, NULL, true);
 	if (hdl->error) {
 		video_device_release(dev->empress_dev);
 		return hdl->error;
diff --git a/drivers/media/pci/saa7134/saa7134-video.c b/drivers/media/pci/saa7134/saa7134-video.c
index 1a50ec9d084f..41d46488d22e 100644
--- a/drivers/media/pci/saa7134/saa7134-video.c
+++ b/drivers/media/pci/saa7134/saa7134-video.c
@@ -2136,7 +2136,7 @@ int saa7134_video_init1(struct saa7134_dev *dev)
 		hdl = &dev->radio_ctrl_handler;
 		v4l2_ctrl_handler_init(hdl, 2);
 		v4l2_ctrl_add_handler(hdl, &dev->ctrl_handler,
-				v4l2_ctrl_radio_filter);
+				v4l2_ctrl_radio_filter, false);
 		if (hdl->error)
 			return hdl->error;
 	}
diff --git a/drivers/media/platform/exynos4-is/fimc-capture.c b/drivers/media/platform/exynos4-is/fimc-capture.c
index a3cdac188190..2164375f0ee0 100644
--- a/drivers/media/platform/exynos4-is/fimc-capture.c
+++ b/drivers/media/platform/exynos4-is/fimc-capture.c
@@ -1424,7 +1424,7 @@ static int fimc_link_setup(struct media_entity *entity,
 		return 0;
 
 	return v4l2_ctrl_add_handler(&vc->ctx->ctrls.handler,
-				     sensor->ctrl_handler, NULL);
+				     sensor->ctrl_handler, NULL, true);
 }
 
 static const struct media_entity_operations fimc_sd_media_ops = {
diff --git a/drivers/media/platform/rcar-vin/rcar-v4l2.c b/drivers/media/platform/rcar-vin/rcar-v4l2.c
index b479b882da12..90246113fa03 100644
--- a/drivers/media/platform/rcar-vin/rcar-v4l2.c
+++ b/drivers/media/platform/rcar-vin/rcar-v4l2.c
@@ -900,7 +900,8 @@ int rvin_v4l2_probe(struct rvin_dev *vin)
 	if (ret < 0)
 		return ret;
 
-	ret = v4l2_ctrl_add_handler(&vin->ctrl_handler, sd->ctrl_handler, NULL);
+	ret = v4l2_ctrl_add_handler(&vin->ctrl_handler, sd->ctrl_handler,
+				    NULL, true);
 	if (ret < 0)
 		return ret;
 
diff --git a/drivers/media/platform/rcar_drif.c b/drivers/media/platform/rcar_drif.c
index dc7e280c91b4..159c7d2c2066 100644
--- a/drivers/media/platform/rcar_drif.c
+++ b/drivers/media/platform/rcar_drif.c
@@ -1168,7 +1168,7 @@ static int rcar_drif_notify_complete(struct v4l2_async_notifier *notifier)
 	}
 
 	ret = v4l2_ctrl_add_handler(&sdr->ctrl_hdl,
-				    sdr->ep.subdev->ctrl_handler, NULL);
+				    sdr->ep.subdev->ctrl_handler, NULL, true);
 	if (ret) {
 		rdrif_err(sdr, "failed: ctrl add hdlr ret %d\n", ret);
 		goto error;
diff --git a/drivers/media/platform/soc_camera/soc_camera.c b/drivers/media/platform/soc_camera/soc_camera.c
index 69f0d8e80bd8..e6787abc34ae 100644
--- a/drivers/media/platform/soc_camera/soc_camera.c
+++ b/drivers/media/platform/soc_camera/soc_camera.c
@@ -1180,7 +1180,8 @@ static int soc_camera_probe_finish(struct soc_camera_device *icd)
 
 	v4l2_subdev_call(sd, video, g_tvnorms, &icd->vdev->tvnorms);
 
-	ret = v4l2_ctrl_add_handler(&icd->ctrl_handler, sd->ctrl_handler, NULL);
+	ret = v4l2_ctrl_add_handler(&icd->ctrl_handler, sd->ctrl_handler,
+				    NULL, true);
 	if (ret < 0)
 		return ret;
 
diff --git a/drivers/media/platform/vivid/vivid-ctrls.c b/drivers/media/platform/vivid/vivid-ctrls.c
index 6b0bfa091592..f369b94ad7ff 100644
--- a/drivers/media/platform/vivid/vivid-ctrls.c
+++ b/drivers/media/platform/vivid/vivid-ctrls.c
@@ -1662,59 +1662,59 @@ int vivid_create_controls(struct vivid_dev *dev, bool show_ccs_cap,
 		v4l2_ctrl_auto_cluster(2, &dev->autogain, 0, true);
 
 	if (dev->has_vid_cap) {
-		v4l2_ctrl_add_handler(hdl_vid_cap, hdl_user_gen, NULL);
-		v4l2_ctrl_add_handler(hdl_vid_cap, hdl_user_vid, NULL);
-		v4l2_ctrl_add_handler(hdl_vid_cap, hdl_user_aud, NULL);
-		v4l2_ctrl_add_handler(hdl_vid_cap, hdl_streaming, NULL);
-		v4l2_ctrl_add_handler(hdl_vid_cap, hdl_sdtv_cap, NULL);
-		v4l2_ctrl_add_handler(hdl_vid_cap, hdl_loop_cap, NULL);
-		v4l2_ctrl_add_handler(hdl_vid_cap, hdl_fb, NULL);
+		v4l2_ctrl_add_handler(hdl_vid_cap, hdl_user_gen, NULL, false);
+		v4l2_ctrl_add_handler(hdl_vid_cap, hdl_user_vid, NULL, false);
+		v4l2_ctrl_add_handler(hdl_vid_cap, hdl_user_aud, NULL, false);
+		v4l2_ctrl_add_handler(hdl_vid_cap, hdl_streaming, NULL, false);
+		v4l2_ctrl_add_handler(hdl_vid_cap, hdl_sdtv_cap, NULL, false);
+		v4l2_ctrl_add_handler(hdl_vid_cap, hdl_loop_cap, NULL, false);
+		v4l2_ctrl_add_handler(hdl_vid_cap, hdl_fb, NULL, false);
 		if (hdl_vid_cap->error)
 			return hdl_vid_cap->error;
 		dev->vid_cap_dev.ctrl_handler = hdl_vid_cap;
 	}
 	if (dev->has_vid_out) {
-		v4l2_ctrl_add_handler(hdl_vid_out, hdl_user_gen, NULL);
-		v4l2_ctrl_add_handler(hdl_vid_out, hdl_user_aud, NULL);
-		v4l2_ctrl_add_handler(hdl_vid_out, hdl_streaming, NULL);
-		v4l2_ctrl_add_handler(hdl_vid_out, hdl_fb, NULL);
+		v4l2_ctrl_add_handler(hdl_vid_out, hdl_user_gen, NULL, false);
+		v4l2_ctrl_add_handler(hdl_vid_out, hdl_user_aud, NULL, false);
+		v4l2_ctrl_add_handler(hdl_vid_out, hdl_streaming, NULL, false);
+		v4l2_ctrl_add_handler(hdl_vid_out, hdl_fb, NULL, false);
 		if (hdl_vid_out->error)
 			return hdl_vid_out->error;
 		dev->vid_out_dev.ctrl_handler = hdl_vid_out;
 	}
 	if (dev->has_vbi_cap) {
-		v4l2_ctrl_add_handler(hdl_vbi_cap, hdl_user_gen, NULL);
-		v4l2_ctrl_add_handler(hdl_vbi_cap, hdl_streaming, NULL);
-		v4l2_ctrl_add_handler(hdl_vbi_cap, hdl_sdtv_cap, NULL);
-		v4l2_ctrl_add_handler(hdl_vbi_cap, hdl_loop_cap, NULL);
+		v4l2_ctrl_add_handler(hdl_vbi_cap, hdl_user_gen, NULL, false);
+		v4l2_ctrl_add_handler(hdl_vbi_cap, hdl_streaming, NULL, false);
+		v4l2_ctrl_add_handler(hdl_vbi_cap, hdl_sdtv_cap, NULL, false);
+		v4l2_ctrl_add_handler(hdl_vbi_cap, hdl_loop_cap, NULL, false);
 		if (hdl_vbi_cap->error)
 			return hdl_vbi_cap->error;
 		dev->vbi_cap_dev.ctrl_handler = hdl_vbi_cap;
 	}
 	if (dev->has_vbi_out) {
-		v4l2_ctrl_add_handler(hdl_vbi_out, hdl_user_gen, NULL);
-		v4l2_ctrl_add_handler(hdl_vbi_out, hdl_streaming, NULL);
+		v4l2_ctrl_add_handler(hdl_vbi_out, hdl_user_gen, NULL, false);
+		v4l2_ctrl_add_handler(hdl_vbi_out, hdl_streaming, NULL, false);
 		if (hdl_vbi_out->error)
 			return hdl_vbi_out->error;
 		dev->vbi_out_dev.ctrl_handler = hdl_vbi_out;
 	}
 	if (dev->has_radio_rx) {
-		v4l2_ctrl_add_handler(hdl_radio_rx, hdl_user_gen, NULL);
-		v4l2_ctrl_add_handler(hdl_radio_rx, hdl_user_aud, NULL);
+		v4l2_ctrl_add_handler(hdl_radio_rx, hdl_user_gen, NULL, false);
+		v4l2_ctrl_add_handler(hdl_radio_rx, hdl_user_aud, NULL, false);
 		if (hdl_radio_rx->error)
 			return hdl_radio_rx->error;
 		dev->radio_rx_dev.ctrl_handler = hdl_radio_rx;
 	}
 	if (dev->has_radio_tx) {
-		v4l2_ctrl_add_handler(hdl_radio_tx, hdl_user_gen, NULL);
-		v4l2_ctrl_add_handler(hdl_radio_tx, hdl_user_aud, NULL);
+		v4l2_ctrl_add_handler(hdl_radio_tx, hdl_user_gen, NULL, false);
+		v4l2_ctrl_add_handler(hdl_radio_tx, hdl_user_aud, NULL, false);
 		if (hdl_radio_tx->error)
 			return hdl_radio_tx->error;
 		dev->radio_tx_dev.ctrl_handler = hdl_radio_tx;
 	}
 	if (dev->has_sdr_cap) {
-		v4l2_ctrl_add_handler(hdl_sdr_cap, hdl_user_gen, NULL);
-		v4l2_ctrl_add_handler(hdl_sdr_cap, hdl_streaming, NULL);
+		v4l2_ctrl_add_handler(hdl_sdr_cap, hdl_user_gen, NULL, false);
+		v4l2_ctrl_add_handler(hdl_sdr_cap, hdl_streaming, NULL, false);
 		if (hdl_sdr_cap->error)
 			return hdl_sdr_cap->error;
 		dev->sdr_cap_dev.ctrl_handler = hdl_sdr_cap;
diff --git a/drivers/media/usb/cx231xx/cx231xx-417.c b/drivers/media/usb/cx231xx/cx231xx-417.c
index b80e6857e2eb..fca16cf8b3bf 100644
--- a/drivers/media/usb/cx231xx/cx231xx-417.c
+++ b/drivers/media/usb/cx231xx/cx231xx-417.c
@@ -1991,7 +1991,7 @@ int cx231xx_417_register(struct cx231xx *dev)
 	dev->mpeg_ctrl_handler.ops = &cx231xx_ops;
 	if (dev->sd_cx25840)
 		v4l2_ctrl_add_handler(&dev->mpeg_ctrl_handler.hdl,
-				dev->sd_cx25840->ctrl_handler, NULL);
+				dev->sd_cx25840->ctrl_handler, NULL, false);
 	if (dev->mpeg_ctrl_handler.hdl.error) {
 		err = dev->mpeg_ctrl_handler.hdl.error;
 		dprintk(3, "%s: can't add cx25840 controls\n", dev->name);
diff --git a/drivers/media/usb/cx231xx/cx231xx-video.c b/drivers/media/usb/cx231xx/cx231xx-video.c
index f7fcd733a2ca..2dedb18f63a0 100644
--- a/drivers/media/usb/cx231xx/cx231xx-video.c
+++ b/drivers/media/usb/cx231xx/cx231xx-video.c
@@ -2204,10 +2204,10 @@ int cx231xx_register_analog_devices(struct cx231xx *dev)
 
 	if (dev->sd_cx25840) {
 		v4l2_ctrl_add_handler(&dev->ctrl_handler,
-				dev->sd_cx25840->ctrl_handler, NULL);
+				dev->sd_cx25840->ctrl_handler, NULL, true);
 		v4l2_ctrl_add_handler(&dev->radio_ctrl_handler,
 				dev->sd_cx25840->ctrl_handler,
-				v4l2_ctrl_radio_filter);
+				v4l2_ctrl_radio_filter, true);
 	}
 
 	if (dev->ctrl_handler.error)
diff --git a/drivers/media/usb/msi2500/msi2500.c b/drivers/media/usb/msi2500/msi2500.c
index 65ef755adfdc..4aacd77a5d58 100644
--- a/drivers/media/usb/msi2500/msi2500.c
+++ b/drivers/media/usb/msi2500/msi2500.c
@@ -1278,7 +1278,7 @@ static int msi2500_probe(struct usb_interface *intf,
 	}
 
 	/* currently all controls are from subdev */
-	v4l2_ctrl_add_handler(&dev->hdl, sd->ctrl_handler, NULL);
+	v4l2_ctrl_add_handler(&dev->hdl, sd->ctrl_handler, NULL, true);
 
 	dev->v4l2_dev.ctrl_handler = &dev->hdl;
 	dev->vdev.v4l2_dev = &dev->v4l2_dev;
diff --git a/drivers/media/usb/tm6000/tm6000-video.c b/drivers/media/usb/tm6000/tm6000-video.c
index b2399d4266da..99d6b0da8b3d 100644
--- a/drivers/media/usb/tm6000/tm6000-video.c
+++ b/drivers/media/usb/tm6000/tm6000-video.c
@@ -1622,7 +1622,7 @@ int tm6000_v4l2_register(struct tm6000_core *dev)
 	v4l2_ctrl_new_std(&dev->ctrl_handler, &tm6000_ctrl_ops,
 			V4L2_CID_HUE, -128, 127, 1, 0);
 	v4l2_ctrl_add_handler(&dev->ctrl_handler,
-			&dev->radio_ctrl_handler, NULL);
+			&dev->radio_ctrl_handler, NULL, false);
 
 	if (dev->radio_ctrl_handler.error)
 		ret = dev->radio_ctrl_handler.error;
diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index d29e45516eb7..aa1dd2015e84 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -1995,7 +1995,8 @@ EXPORT_SYMBOL(v4l2_ctrl_find);
 
 /* Allocate a new v4l2_ctrl_ref and hook it into the handler. */
 static int handler_new_ref(struct v4l2_ctrl_handler *hdl,
-			   struct v4l2_ctrl *ctrl)
+			   struct v4l2_ctrl *ctrl,
+			   bool from_other_dev)
 {
 	struct v4l2_ctrl_ref *ref;
 	struct v4l2_ctrl_ref *new_ref;
@@ -2019,6 +2020,7 @@ static int handler_new_ref(struct v4l2_ctrl_handler *hdl,
 	if (!new_ref)
 		return handler_set_err(hdl, -ENOMEM);
 	new_ref->ctrl = ctrl;
+	new_ref->from_other_dev = from_other_dev;
 	if (ctrl->handler == hdl) {
 		/* By default each control starts in a cluster of its own.
 		   new_ref->ctrl is basically a cluster array with one
@@ -2199,7 +2201,7 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
 		ctrl->type_ops->init(ctrl, idx, ctrl->p_new);
 	}
 
-	if (handler_new_ref(hdl, ctrl)) {
+	if (handler_new_ref(hdl, ctrl, false)) {
 		kvfree(ctrl);
 		return NULL;
 	}
@@ -2368,7 +2370,8 @@ EXPORT_SYMBOL(v4l2_ctrl_new_int_menu);
 /* Add the controls from another handler to our own. */
 int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl,
 			  struct v4l2_ctrl_handler *add,
-			  bool (*filter)(const struct v4l2_ctrl *ctrl))
+			  bool (*filter)(const struct v4l2_ctrl *ctrl),
+			  bool from_other_dev)
 {
 	struct v4l2_ctrl_ref *ref;
 	int ret = 0;
@@ -2391,7 +2394,7 @@ int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl,
 		/* Filter any unwanted controls */
 		if (filter && !filter(ctrl))
 			continue;
-		ret = handler_new_ref(hdl, ctrl);
+		ret = handler_new_ref(hdl, ctrl, from_other_dev);
 		if (ret)
 			break;
 	}
diff --git a/drivers/media/v4l2-core/v4l2-device.c b/drivers/media/v4l2-core/v4l2-device.c
index 937c6de85606..8391a7f0895b 100644
--- a/drivers/media/v4l2-core/v4l2-device.c
+++ b/drivers/media/v4l2-core/v4l2-device.c
@@ -178,7 +178,8 @@ int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
 
 	sd->v4l2_dev = v4l2_dev;
 	/* This just returns 0 if either of the two args is NULL */
-	err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler, NULL);
+	err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler,
+				    NULL, true);
 	if (err)
 		goto error_module;
 
diff --git a/drivers/staging/media/imx/imx-media-dev.c b/drivers/staging/media/imx/imx-media-dev.c
index 289d775c4820..08799beaea42 100644
--- a/drivers/staging/media/imx/imx-media-dev.c
+++ b/drivers/staging/media/imx/imx-media-dev.c
@@ -391,7 +391,7 @@ static int imx_media_inherit_controls(struct imx_media_dev *imxmd,
 
 		ret = v4l2_ctrl_add_handler(vfd->ctrl_handler,
 					    sd->ctrl_handler,
-					    NULL);
+					    NULL, true);
 		if (ret)
 			return ret;
 	}
diff --git a/drivers/staging/media/imx/imx-media-fim.c b/drivers/staging/media/imx/imx-media-fim.c
index 6df189135db8..8cf773eef9da 100644
--- a/drivers/staging/media/imx/imx-media-fim.c
+++ b/drivers/staging/media/imx/imx-media-fim.c
@@ -463,7 +463,7 @@ int imx_media_fim_add_controls(struct imx_media_fim *fim)
 {
 	/* add the FIM controls to the calling subdev ctrl handler */
 	return v4l2_ctrl_add_handler(fim->sd->ctrl_handler,
-				     &fim->ctrl_handler, NULL);
+				     &fim->ctrl_handler, NULL, false);
 }
 EXPORT_SYMBOL_GPL(imx_media_fim_add_controls);
 
diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
index 5b445b5654f7..d26b8ddebb56 100644
--- a/include/media/v4l2-ctrls.h
+++ b/include/media/v4l2-ctrls.h
@@ -247,6 +247,8 @@ struct v4l2_ctrl {
  * @ctrl:	The actual control information.
  * @helper:	Pointer to helper struct. Used internally in
  *		``prepare_ext_ctrls`` function at ``v4l2-ctrl.c``.
+ * @from_other_dev: If true, then @ctrl was defined in another
+ *		device than the &struct v4l2_ctrl_handler.
  *
  * Each control handler has a list of these refs. The list_head is used to
  * keep a sorted-by-control-ID list of all controls, while the next pointer
@@ -257,6 +259,7 @@ struct v4l2_ctrl_ref {
 	struct v4l2_ctrl_ref *next;
 	struct v4l2_ctrl *ctrl;
 	struct v4l2_ctrl_helper *helper;
+	bool from_other_dev;
 };
 
 /**
@@ -633,6 +636,8 @@ typedef bool (*v4l2_ctrl_filter)(const struct v4l2_ctrl *ctrl);
  * @add:	The control handler whose controls you want to add to
  *		the @hdl control handler.
  * @filter:	This function will filter which controls should be added.
+ * @from_other_dev: If true, then the controls in @add were defined in another
+ *		device than @hdl.
  *
  * Does nothing if either of the two handlers is a NULL pointer.
  * If @filter is NULL, then all controls are added. Otherwise only those
@@ -642,7 +647,8 @@ typedef bool (*v4l2_ctrl_filter)(const struct v4l2_ctrl *ctrl);
  */
 int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl,
 			  struct v4l2_ctrl_handler *add,
-			  v4l2_ctrl_filter filter);
+			  v4l2_ctrl_filter filter,
+			  bool from_other_dev);
 
 /**
  * v4l2_ctrl_radio_filter() - Standard filter for radio controls.
-- 
2.17.0

[RFCv12 PATCH 09/29] v4l2-ctrls: prepare internal structs for request API

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

Embed and initialize a media_request_object in struct v4l2_ctrl_handler.

Add a p_req field to struct v4l2_ctrl_ref that will store the
request value.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Alexandre Courbot <acourbot@chromium.org>
---
 drivers/media/v4l2-core/v4l2-ctrls.c | 1 +
 include/media/v4l2-ctrls.h           | 7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index aa1dd2015e84..d09f49530d9e 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -1880,6 +1880,7 @@ int v4l2_ctrl_handler_init_class(struct v4l2_ctrl_handler *hdl,
 				      sizeof(hdl->buckets[0]),
 				      GFP_KERNEL | __GFP_ZERO);
 	hdl->error = hdl->buckets ? 0 : -ENOMEM;
+	media_request_object_init(&hdl->req_obj);
 	return hdl->error;
 }
 EXPORT_SYMBOL(v4l2_ctrl_handler_init_class);
diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
index d26b8ddebb56..76352eb59f14 100644
--- a/include/media/v4l2-ctrls.h
+++ b/include/media/v4l2-ctrls.h
@@ -20,6 +20,7 @@
 #include <linux/list.h>
 #include <linux/mutex.h>
 #include <linux/videodev2.h>
+#include <media/media-request.h>
 
 /* forward references */
 struct file;
@@ -249,6 +250,8 @@ struct v4l2_ctrl {
  *		``prepare_ext_ctrls`` function at ``v4l2-ctrl.c``.
  * @from_other_dev: If true, then @ctrl was defined in another
  *		device than the &struct v4l2_ctrl_handler.
+ * @p_req:	The request value. Only used if the control handler
+ *		is bound to a media request.
  *
  * Each control handler has a list of these refs. The list_head is used to
  * keep a sorted-by-control-ID list of all controls, while the next pointer
@@ -260,6 +263,7 @@ struct v4l2_ctrl_ref {
 	struct v4l2_ctrl *ctrl;
 	struct v4l2_ctrl_helper *helper;
 	bool from_other_dev;
+	union v4l2_ctrl_ptr p_req;
 };
 
 /**
@@ -283,6 +287,8 @@ struct v4l2_ctrl_ref {
  * @notify_priv: Passed as argument to the v4l2_ctrl notify callback.
  * @nr_of_buckets: Total number of buckets in the array.
  * @error:	The error code of the first failed control addition.
+ * @req_obj:	The &struct media_request_object, used to link into a
+ *		&struct media_request.
  */
 struct v4l2_ctrl_handler {
 	struct mutex _lock;
@@ -295,6 +301,7 @@ struct v4l2_ctrl_handler {
 	void *notify_priv;
 	u16 nr_of_buckets;
 	int error;
+	struct media_request_object req_obj;
 };
 
 /**
-- 
2.17.0

[RFCv12 PATCH 10/29] v4l2-ctrls: alloc memory for p_req

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

To store request data the handler_new_ref() allocates memory
for it if needed.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/v4l2-ctrls.c | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index d09f49530d9e..3c1b00baa8d0 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -1997,13 +1997,18 @@ EXPORT_SYMBOL(v4l2_ctrl_find);
 /* Allocate a new v4l2_ctrl_ref and hook it into the handler. */
 static int handler_new_ref(struct v4l2_ctrl_handler *hdl,
 			   struct v4l2_ctrl *ctrl,
-			   bool from_other_dev)
+			   struct v4l2_ctrl_ref **ctrl_ref,
+			   bool from_other_dev, bool allocate_req)
 {
 	struct v4l2_ctrl_ref *ref;
 	struct v4l2_ctrl_ref *new_ref;
 	u32 id = ctrl->id;
 	u32 class_ctrl = V4L2_CTRL_ID2WHICH(id) | 1;
 	int bucket = id % hdl->nr_of_buckets;	/* which bucket to use */
+	unsigned int sz_extra = 0;
+
+	if (ctrl_ref)
+		*ctrl_ref = NULL;
 
 	/*
 	 * Automatically add the control class if it is not yet present and
@@ -2017,11 +2022,16 @@ static int handler_new_ref(struct v4l2_ctrl_handler *hdl,
 	if (hdl->error)
 		return hdl->error;
 
-	new_ref = kzalloc(sizeof(*new_ref), GFP_KERNEL);
+	if (allocate_req)
+		sz_extra = ctrl->elems * ctrl->elem_size;
+	new_ref = kzalloc(sizeof(*new_ref) + sz_extra, GFP_KERNEL);
 	if (!new_ref)
 		return handler_set_err(hdl, -ENOMEM);
 	new_ref->ctrl = ctrl;
 	new_ref->from_other_dev = from_other_dev;
+	if (sz_extra)
+		new_ref->p_req.p = &new_ref[1];
+
 	if (ctrl->handler == hdl) {
 		/* By default each control starts in a cluster of its own.
 		   new_ref->ctrl is basically a cluster array with one
@@ -2061,6 +2071,8 @@ static int handler_new_ref(struct v4l2_ctrl_handler *hdl,
 	/* Insert the control node in the hash */
 	new_ref->next = hdl->buckets[bucket];
 	hdl->buckets[bucket] = new_ref;
+	if (ctrl_ref)
+		*ctrl_ref = new_ref;
 
 unlock:
 	mutex_unlock(hdl->lock);
@@ -2202,7 +2214,7 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
 		ctrl->type_ops->init(ctrl, idx, ctrl->p_new);
 	}
 
-	if (handler_new_ref(hdl, ctrl, false)) {
+	if (handler_new_ref(hdl, ctrl, NULL, false, false)) {
 		kvfree(ctrl);
 		return NULL;
 	}
@@ -2395,7 +2407,7 @@ int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl,
 		/* Filter any unwanted controls */
 		if (filter && !filter(ctrl))
 			continue;
-		ret = handler_new_ref(hdl, ctrl, from_other_dev);
+		ret = handler_new_ref(hdl, ctrl, NULL, from_other_dev, false);
 		if (ret)
 			break;
 	}
-- 
2.17.0

[RFCv12 PATCH 11/29] v4l2-ctrls: use ref in helper instead of ctrl

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

The next patch needs the reference to a control instead of the
control itself, so change struct v4l2_ctrl_helper accordingly.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/v4l2-ctrls.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index 3c1b00baa8d0..da4cc1485dc4 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -37,8 +37,8 @@
 struct v4l2_ctrl_helper {
 	/* Pointer to the control reference of the master control */
 	struct v4l2_ctrl_ref *mref;
-	/* The control corresponding to the v4l2_ext_control ID field. */
-	struct v4l2_ctrl *ctrl;
+	/* The control ref corresponding to the v4l2_ext_control ID field. */
+	struct v4l2_ctrl_ref *ref;
 	/* v4l2_ext_control index of the next control belonging to the
 	   same cluster, or 0 if there isn't any. */
 	u32 next;
@@ -2887,6 +2887,7 @@ static int prepare_ext_ctrls(struct v4l2_ctrl_handler *hdl,
 		ref = find_ref_lock(hdl, id);
 		if (ref == NULL)
 			return -EINVAL;
+		h->ref = ref;
 		ctrl = ref->ctrl;
 		if (ctrl->flags & V4L2_CTRL_FLAG_DISABLED)
 			return -EINVAL;
@@ -2909,7 +2910,6 @@ static int prepare_ext_ctrls(struct v4l2_ctrl_handler *hdl,
 		}
 		/* Store the ref to the master control of the cluster */
 		h->mref = ref;
-		h->ctrl = ctrl;
 		/* Initially set next to 0, meaning that there is no other
 		   control in this helper array belonging to the same
 		   cluster */
@@ -2994,7 +2994,7 @@ int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs
 	cs->error_idx = cs->count;
 
 	for (i = 0; !ret && i < cs->count; i++)
-		if (helpers[i].ctrl->flags & V4L2_CTRL_FLAG_WRITE_ONLY)
+		if (helpers[i].ref->ctrl->flags & V4L2_CTRL_FLAG_WRITE_ONLY)
 			ret = -EACCES;
 
 	for (i = 0; !ret && i < cs->count; i++) {
@@ -3029,7 +3029,7 @@ int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs
 
 			do {
 				ret = ctrl_to_user(cs->controls + idx,
-						   helpers[idx].ctrl);
+						   helpers[idx].ref->ctrl);
 				idx = helpers[idx].next;
 			} while (!ret && idx);
 		}
@@ -3168,7 +3168,7 @@ static int validate_ctrls(struct v4l2_ext_controls *cs,
 
 	cs->error_idx = cs->count;
 	for (i = 0; i < cs->count; i++) {
-		struct v4l2_ctrl *ctrl = helpers[i].ctrl;
+		struct v4l2_ctrl *ctrl = helpers[i].ref->ctrl;
 		union v4l2_ctrl_ptr p_new;
 
 		cs->error_idx = i;
@@ -3280,7 +3280,7 @@ static int try_set_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
 			do {
 				/* Check if the auto control is part of the
 				   list, and remember the new value. */
-				if (helpers[tmp_idx].ctrl == master)
+				if (helpers[tmp_idx].ref->ctrl == master)
 					new_auto_val = cs->controls[tmp_idx].value;
 				tmp_idx = helpers[tmp_idx].next;
 			} while (tmp_idx);
@@ -3293,7 +3293,7 @@ static int try_set_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
 		/* Copy the new caller-supplied control values.
 		   user_to_new() sets 'is_new' to 1. */
 		do {
-			struct v4l2_ctrl *ctrl = helpers[idx].ctrl;
+			struct v4l2_ctrl *ctrl = helpers[idx].ref->ctrl;
 
 			ret = user_to_new(cs->controls + idx, ctrl);
 			if (!ret && ctrl->is_ptr)
@@ -3309,7 +3309,7 @@ static int try_set_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
 			idx = i;
 			do {
 				ret = new_to_user(cs->controls + idx,
-						helpers[idx].ctrl);
+						helpers[idx].ref->ctrl);
 				idx = helpers[idx].next;
 			} while (!ret && idx);
 		}
-- 
2.17.0

[RFCv12 PATCH 12/29] v4l2-ctrls: add core request support

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

Integrate the request support. This adds the v4l2_ctrl_request_complete
and v4l2_ctrl_request_setup functions to complete a request and (as a
helper function) to apply a request to the hardware.

It takes care of queuing requests and correctly chaining control values
in the request queue.

Note that when a request is marked completed it will copy control values
to the internal request state. This can be optimized in the future since
this is sub-optimal when dealing with large compound and/or array controls.

For the initial 'stateless codec' use-case the current implementation is
sufficient.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/v4l2-ctrls.c | 341 ++++++++++++++++++++++++++-
 include/media/v4l2-ctrls.h           |  23 ++
 2 files changed, 358 insertions(+), 6 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index da4cc1485dc4..27279cb19f61 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -1647,6 +1647,13 @@ static int new_to_user(struct v4l2_ext_control *c,
 	return ptr_to_user(c, ctrl, ctrl->p_new);
 }
 
+/* Helper function: copy the request value back to the caller */
+static int req_to_user(struct v4l2_ext_control *c,
+		       struct v4l2_ctrl_ref *ref)
+{
+	return ptr_to_user(c, ref->ctrl, ref->p_req);
+}
+
 /* Helper function: copy the initial control value back to the caller */
 static int def_to_user(struct v4l2_ext_control *c, struct v4l2_ctrl *ctrl)
 {
@@ -1766,6 +1773,26 @@ static void cur_to_new(struct v4l2_ctrl *ctrl)
 	ptr_to_ptr(ctrl, ctrl->p_cur, ctrl->p_new);
 }
 
+/* Copy the new value to the request value */
+static void new_to_req(struct v4l2_ctrl_ref *ref)
+{
+	if (!ref)
+		return;
+	ptr_to_ptr(ref->ctrl, ref->ctrl->p_new, ref->p_req);
+	ref->req = ref;
+}
+
+/* Copy the request value to the new value */
+static void req_to_new(struct v4l2_ctrl_ref *ref)
+{
+	if (!ref)
+		return;
+	if (ref->req)
+		ptr_to_ptr(ref->ctrl, ref->req->p_req, ref->ctrl->p_new);
+	else
+		ptr_to_ptr(ref->ctrl, ref->ctrl->p_cur, ref->ctrl->p_new);
+}
+
 /* Return non-zero if one or more of the controls in the cluster has a new
    value that differs from the current value. */
 static int cluster_changed(struct v4l2_ctrl *master)
@@ -1875,6 +1902,9 @@ int v4l2_ctrl_handler_init_class(struct v4l2_ctrl_handler *hdl,
 	lockdep_set_class_and_name(hdl->lock, key, name);
 	INIT_LIST_HEAD(&hdl->ctrls);
 	INIT_LIST_HEAD(&hdl->ctrl_refs);
+	INIT_LIST_HEAD(&hdl->requests);
+	INIT_LIST_HEAD(&hdl->requests_queued);
+	hdl->request_is_queued = false;
 	hdl->nr_of_buckets = 1 + nr_of_controls_hint / 8;
 	hdl->buckets = kvmalloc_array(hdl->nr_of_buckets,
 				      sizeof(hdl->buckets[0]),
@@ -1895,6 +1925,14 @@ void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl)
 	if (hdl == NULL || hdl->buckets == NULL)
 		return;
 
+	if (!hdl->req_obj.req && !list_empty(&hdl->requests)) {
+		struct v4l2_ctrl_handler *req, *next_req;
+
+		list_for_each_entry_safe(req, next_req, &hdl->requests, requests) {
+			media_request_object_unbind(&req->req_obj);
+			media_request_object_put(&req->req_obj);
+		}
+	}
 	mutex_lock(hdl->lock);
 	/* Free all nodes */
 	list_for_each_entry_safe(ref, next_ref, &hdl->ctrl_refs, node) {
@@ -2816,6 +2854,138 @@ int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm)
 }
 EXPORT_SYMBOL(v4l2_querymenu);
 
+static int v4l2_ctrl_request_clone(struct v4l2_ctrl_handler *hdl,
+				   const struct v4l2_ctrl_handler *from)
+{
+	struct v4l2_ctrl_ref *ref;
+	int err;
+
+	if (WARN_ON(!hdl || hdl == from))
+		return -EINVAL;
+
+	if (hdl->error)
+		return hdl->error;
+
+	WARN_ON(hdl->lock != &hdl->_lock);
+
+	mutex_lock(from->lock);
+	list_for_each_entry(ref, &from->ctrl_refs, node) {
+		struct v4l2_ctrl *ctrl = ref->ctrl;
+		struct v4l2_ctrl_ref *new_ref;
+
+		/* Skip refs inherited from other devices */
+		if (ref->from_other_dev)
+			continue;
+		/* And buttons */
+		if (ctrl->type == V4L2_CTRL_TYPE_BUTTON)
+			continue;
+		err = handler_new_ref(hdl, ctrl, &new_ref, false, true);
+		if (err) {
+			printk("%s: handler_new_ref on control %x (%s) returned %d\n", __func__, ctrl->id, ctrl->name, err);
+			err = 0;
+			continue;
+		}
+		if (err)
+			break;
+	}
+	mutex_unlock(from->lock);
+	return err;
+}
+
+static void v4l2_ctrl_request_queue(struct media_request_object *obj)
+{
+	struct v4l2_ctrl_handler *hdl =
+		container_of(obj, struct v4l2_ctrl_handler, req_obj);
+	struct v4l2_ctrl_handler *main_hdl = obj->priv;
+	struct v4l2_ctrl_handler *prev_hdl = NULL;
+	struct v4l2_ctrl_ref *ref_ctrl, *ref_ctrl_prev = NULL;
+
+	if (list_empty(&main_hdl->requests_queued))
+		goto queue;
+
+	prev_hdl = list_last_entry(&main_hdl->requests_queued,
+				   struct v4l2_ctrl_handler, requests_queued);
+	/*
+	 * Note: prev_hdl and hdl must contain the same list of control
+	 * references, so if any differences are detected then that is a
+	 * driver bug and the WARN_ON is triggered.
+	 */
+	mutex_lock(prev_hdl->lock);
+	ref_ctrl_prev = list_first_entry(&prev_hdl->ctrl_refs,
+					 struct v4l2_ctrl_ref, node);
+	list_for_each_entry(ref_ctrl, &hdl->ctrl_refs, node) {
+		if (ref_ctrl->req)
+			continue;
+		while (ref_ctrl_prev->ctrl->id < ref_ctrl->ctrl->id) {
+			/* Should never happen, but just in case... */
+			if (list_is_last(&ref_ctrl_prev->node,
+					 &prev_hdl->ctrl_refs))
+				break;
+			ref_ctrl_prev = list_next_entry(ref_ctrl_prev, node);
+		}
+		if (WARN_ON(ref_ctrl_prev->ctrl->id != ref_ctrl->ctrl->id))
+			break;
+		ref_ctrl->req = ref_ctrl_prev->req;
+	}
+	mutex_unlock(prev_hdl->lock);
+queue:
+	list_add_tail(&hdl->requests_queued, &main_hdl->requests_queued);
+	hdl->request_is_queued = true;
+}
+
+static void v4l2_ctrl_request_unbind(struct media_request_object *obj)
+{
+	struct v4l2_ctrl_handler *hdl =
+		container_of(obj, struct v4l2_ctrl_handler, req_obj);
+
+	list_del_init(&hdl->requests);
+	if (hdl->request_is_queued) {
+		list_del_init(&hdl->requests_queued);
+		hdl->request_is_queued = false;
+	}
+}
+
+static void v4l2_ctrl_request_cancel(struct media_request_object *obj)
+{
+	struct v4l2_ctrl_handler *hdl =
+		container_of(obj, struct v4l2_ctrl_handler, req_obj);
+
+	if (hdl->request_is_queued)
+		v4l2_ctrl_request_complete(hdl->req_obj.req, hdl->req_obj.priv);
+}
+
+static void v4l2_ctrl_request_release(struct media_request_object *obj)
+{
+	struct v4l2_ctrl_handler *hdl =
+		container_of(obj, struct v4l2_ctrl_handler, req_obj);
+
+	v4l2_ctrl_handler_free(hdl);
+	kfree(hdl);
+}
+
+static const struct media_request_object_ops req_ops = {
+	.queue = v4l2_ctrl_request_queue,
+	.unbind = v4l2_ctrl_request_unbind,
+	.cancel = v4l2_ctrl_request_cancel,
+	.release = v4l2_ctrl_request_release,
+};
+
+static int v4l2_ctrl_request_bind(struct media_request *req,
+			   struct v4l2_ctrl_handler *hdl,
+			   struct v4l2_ctrl_handler *from)
+{
+	int ret;
+
+	ret = v4l2_ctrl_request_clone(hdl, from);
+
+	if (!ret) {
+		ret = media_request_object_bind(req, &req_ops,
+						from, &hdl->req_obj);
+		if (!ret)
+			list_add_tail(&hdl->requests, &from->requests);
+	}
+	return ret;
+}
 
 /* Some general notes on the atomic requirements of VIDIOC_G/TRY/S_EXT_CTRLS:
 
@@ -2877,6 +3047,7 @@ static int prepare_ext_ctrls(struct v4l2_ctrl_handler *hdl,
 
 		if (cs->which &&
 		    cs->which != V4L2_CTRL_WHICH_DEF_VAL &&
+		    cs->which != V4L2_CTRL_WHICH_REQUEST_VAL &&
 		    V4L2_CTRL_ID2WHICH(id) != cs->which)
 			return -EINVAL;
 
@@ -2956,13 +3127,12 @@ static int prepare_ext_ctrls(struct v4l2_ctrl_handler *hdl,
    whether there are any controls at all. */
 static int class_check(struct v4l2_ctrl_handler *hdl, u32 which)
 {
-	if (which == 0 || which == V4L2_CTRL_WHICH_DEF_VAL)
+	if (which == 0 || which == V4L2_CTRL_WHICH_DEF_VAL ||
+	    which == V4L2_CTRL_WHICH_REQUEST_VAL)
 		return 0;
 	return find_ref_lock(hdl, which | 1) ? 0 : -EINVAL;
 }
 
-
-
 /* Get extended controls. Allocates the helpers array if needed. */
 int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs)
 {
@@ -3028,8 +3198,12 @@ int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs
 			u32 idx = i;
 
 			do {
-				ret = ctrl_to_user(cs->controls + idx,
-						   helpers[idx].ref->ctrl);
+				if (helpers[idx].ref->req)
+					ret = req_to_user(cs->controls + idx,
+						helpers[idx].ref->req);
+				else
+					ret = ctrl_to_user(cs->controls + idx,
+						helpers[idx].ref->ctrl);
 				idx = helpers[idx].next;
 			} while (!ret && idx);
 		}
@@ -3302,7 +3476,16 @@ static int try_set_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
 		} while (!ret && idx);
 
 		if (!ret)
-			ret = try_or_set_cluster(fh, master, set, 0);
+			ret = try_or_set_cluster(fh, master,
+						 !hdl->req_obj.req && set, 0);
+		if (!ret && hdl->req_obj.req && set) {
+			for (j = 0; j < master->ncontrols; j++) {
+				struct v4l2_ctrl_ref *ref =
+					find_ref(hdl, master->cluster[j]->id);
+
+				new_to_req(ref);
+			}
+		}
 
 		/* Copy the new values back to userspace. */
 		if (!ret) {
@@ -3429,6 +3612,152 @@ int __v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s)
 }
 EXPORT_SYMBOL(__v4l2_ctrl_s_ctrl_string);
 
+void v4l2_ctrl_request_complete(struct media_request *req,
+				struct v4l2_ctrl_handler *main_hdl)
+{
+	struct media_request_object *obj;
+	struct v4l2_ctrl_handler *hdl;
+	struct v4l2_ctrl_ref *ref;
+
+	if (!req || !main_hdl)
+		return;
+
+	obj = media_request_object_find(req, &req_ops, main_hdl);
+	if (!obj)
+		return;
+	hdl = container_of(obj, struct v4l2_ctrl_handler, req_obj);
+
+	list_for_each_entry(ref, &hdl->ctrl_refs, node) {
+		struct v4l2_ctrl *ctrl = ref->ctrl;
+		struct v4l2_ctrl *master = ctrl->cluster[0];
+		unsigned int i;
+
+		if (ctrl->flags & V4L2_CTRL_FLAG_VOLATILE) {
+			ref->req = ref;
+
+			v4l2_ctrl_lock(master);
+			/* g_volatile_ctrl will update the current control values */
+			for (i = 0; i < master->ncontrols; i++)
+				cur_to_new(master->cluster[i]);
+			call_op(master, g_volatile_ctrl);
+			new_to_req(ref);
+			v4l2_ctrl_unlock(master);
+			continue;
+		}
+		if (ref->req == ref)
+			continue;
+
+		v4l2_ctrl_lock(ctrl);
+		if (ref->req)
+			ptr_to_ptr(ctrl, ref->req->p_req, ref->p_req);
+		else
+			ptr_to_ptr(ctrl, ctrl->p_cur, ref->p_req);
+		v4l2_ctrl_unlock(ctrl);
+	}
+
+	WARN_ON(!hdl->request_is_queued);
+	list_del_init(&hdl->requests_queued);
+	hdl->request_is_queued = false;
+	media_request_object_complete(obj);
+	media_request_object_put(obj);
+}
+EXPORT_SYMBOL(v4l2_ctrl_request_complete);
+
+void v4l2_ctrl_request_setup(struct media_request *req,
+			     struct v4l2_ctrl_handler *main_hdl)
+{
+	struct media_request_object *obj;
+	struct v4l2_ctrl_handler *hdl;
+	struct v4l2_ctrl_ref *ref;
+
+	if (!req || !main_hdl)
+		return;
+
+	obj = media_request_object_find(req, &req_ops, main_hdl);
+	if (!obj)
+		return;
+	if (obj->completed) {
+		media_request_object_put(obj);
+		return;
+	}
+	hdl = container_of(obj, struct v4l2_ctrl_handler, req_obj);
+
+	mutex_lock(hdl->lock);
+
+	list_for_each_entry(ref, &hdl->ctrl_refs, node)
+		ref->done = false;
+
+	list_for_each_entry(ref, &hdl->ctrl_refs, node) {
+		struct v4l2_ctrl *ctrl = ref->ctrl;
+		struct v4l2_ctrl *master = ctrl->cluster[0];
+		bool have_new_data = false;
+		int i;
+
+		/*
+		 * Skip if this control was already handled by a cluster.
+		 * Skip button controls and read-only controls.
+		 */
+		if (ref->done || ctrl->type == V4L2_CTRL_TYPE_BUTTON ||
+		    (ctrl->flags & V4L2_CTRL_FLAG_READ_ONLY))
+			continue;
+
+		v4l2_ctrl_lock(master);
+		for (i = 0; i < master->ncontrols; i++) {
+			if (master->cluster[i]) {
+				struct v4l2_ctrl_ref *r =
+					find_ref(hdl, master->cluster[i]->id);
+
+				if (r->req && r == r->req) {
+					have_new_data = true;
+					break;
+				}
+			}
+		}
+		if (!have_new_data) {
+			v4l2_ctrl_unlock(master);
+			continue;
+		}
+
+		for (i = 0; i < master->ncontrols; i++) {
+			if (master->cluster[i]) {
+				struct v4l2_ctrl_ref *r =
+					find_ref(hdl, master->cluster[i]->id);
+
+				req_to_new(r);
+				master->cluster[i]->is_new = 1;
+				r->done = true;
+			}
+		}
+		/*
+		 * For volatile autoclusters that are currently in auto mode
+		 * we need to discover if it will be set to manual mode.
+		 * If so, then we have to copy the current volatile values
+		 * first since those will become the new manual values (which
+		 * may be overwritten by explicit new values from this set
+		 * of controls).
+		 */
+		if (master->is_auto && master->has_volatiles &&
+		    !is_cur_manual(master)) {
+			s32 new_auto_val = *master->p_new.p_s32;
+
+			/*
+			 * If the new value == the manual value, then copy
+			 * the current volatile values.
+			 */
+			if (new_auto_val == master->manual_mode_value)
+				update_from_auto_cluster(master);
+		}
+
+		try_or_set_cluster(NULL, master, true, 0);
+
+		v4l2_ctrl_unlock(master);
+	}
+
+	mutex_unlock(hdl->lock);
+	media_request_object_put(obj);
+}
+EXPORT_SYMBOL(v4l2_ctrl_request_setup);
+
 void v4l2_ctrl_notify(struct v4l2_ctrl *ctrl, v4l2_ctrl_notify_fnc notify, void *priv)
 {
 	if (ctrl == NULL)
diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
index 76352eb59f14..a0f7c38d1a90 100644
--- a/include/media/v4l2-ctrls.h
+++ b/include/media/v4l2-ctrls.h
@@ -250,6 +250,10 @@ struct v4l2_ctrl {
  *		``prepare_ext_ctrls`` function at ``v4l2-ctrl.c``.
  * @from_other_dev: If true, then @ctrl was defined in another
  *		device than the &struct v4l2_ctrl_handler.
+ * @done:	If true, then this control reference is part of a
+ *		control cluster that was already set while applying
+ *		the controls in this media request object.
+ * @req:	If set, this refers to another request that sets this control.
  * @p_req:	The request value. Only used if the control handler
  *		is bound to a media request.
  *
@@ -263,6 +267,8 @@ struct v4l2_ctrl_ref {
 	struct v4l2_ctrl *ctrl;
 	struct v4l2_ctrl_helper *helper;
 	bool from_other_dev;
+	bool done;
+	struct v4l2_ctrl_ref *req;
 	union v4l2_ctrl_ptr p_req;
 };
 
@@ -287,6 +293,15 @@ struct v4l2_ctrl_ref {
  * @notify_priv: Passed as argument to the v4l2_ctrl notify callback.
  * @nr_of_buckets: Total number of buckets in the array.
  * @error:	The error code of the first failed control addition.
+ * @request_is_queued: True if the request was queued.
+ * @requests:	List to keep track of open control handler request objects.
+ *		For the parent control handler (@req_obj.req == NULL) this
+ *		is the list header. When the parent control handler is
+ *		removed, it has to unbind and put all these requests since
+ *		they refer to the parent.
+ * @requests_queued: List of the queued requests. This determines the order
+ *		in which these controls are applied. Once the request is
+ *		completed it is removed from this list.
  * @req_obj:	The &struct media_request_object, used to link into a
  *		&struct media_request.
  */
@@ -301,6 +316,9 @@ struct v4l2_ctrl_handler {
 	void *notify_priv;
 	u16 nr_of_buckets;
 	int error;
+	bool request_is_queued;
+	struct list_head requests;
+	struct list_head requests_queued;
 	struct media_request_object req_obj;
 };
 
@@ -1059,6 +1077,11 @@ int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh,
  */
 __poll_t v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait);
 
+void v4l2_ctrl_request_setup(struct media_request *req,
+			     struct v4l2_ctrl_handler *hdl);
+void v4l2_ctrl_request_complete(struct media_request *req,
+				struct v4l2_ctrl_handler *hdl);
+
 /* Helpers for ioctl_ops */
 
 /**
-- 
2.17.0

[RFCv12 PATCH 13/29] v4l2-ctrls: support g/s_ext_ctrls for requests

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

The v4l2_g/s_ext_ctrls functions now support control handlers that
represent requests.

The v4l2_ctrls_find_req_obj() function is responsible for finding the
request from the fd.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/platform/omap3isp/ispvideo.c |   2 +-
 drivers/media/v4l2-core/v4l2-ctrls.c       | 113 +++++++++++++++++++--
 drivers/media/v4l2-core/v4l2-ioctl.c       |  12 +--
 drivers/media/v4l2-core/v4l2-subdev.c      |   9 +-
 include/media/v4l2-ctrls.h                 |   7 +-
 5 files changed, 124 insertions(+), 19 deletions(-)

diff --git a/drivers/media/platform/omap3isp/ispvideo.c b/drivers/media/platform/omap3isp/ispvideo.c
index a751c89a3ea8..bd564c2e767f 100644
--- a/drivers/media/platform/omap3isp/ispvideo.c
+++ b/drivers/media/platform/omap3isp/ispvideo.c
@@ -1028,7 +1028,7 @@ static int isp_video_check_external_subdevs(struct isp_video *video,
 	ctrls.count = 1;
 	ctrls.controls = &ctrl;
 
-	ret = v4l2_g_ext_ctrls(pipe->external->ctrl_handler, &ctrls);
+	ret = v4l2_g_ext_ctrls(pipe->external->ctrl_handler, NULL, &ctrls);
 	if (ret < 0) {
 		dev_warn(isp->dev, "no pixel rate control in subdev %s\n",
 			 pipe->external->name);
diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index 27279cb19f61..ec15255dbc0e 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -3134,7 +3134,8 @@ static int class_check(struct v4l2_ctrl_handler *hdl, u32 which)
 }
 
 /* Get extended controls. Allocates the helpers array if needed. */
-int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs)
+int __v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl,
+		       struct v4l2_ext_controls *cs)
 {
 	struct v4l2_ctrl_helper helper[4];
 	struct v4l2_ctrl_helper *helpers = helper;
@@ -3214,6 +3215,73 @@ int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs
 		kvfree(helpers);
 	return ret;
 }
+
+static struct media_request_object *
+v4l2_ctrls_find_req_obj(struct v4l2_ctrl_handler *hdl,
+			struct media_device *mdev, s32 fd, bool set)
+{
+	struct media_request *req = media_request_find(mdev, fd);
+	struct media_request_object *obj;
+	struct v4l2_ctrl_handler *new_hdl;
+	int ret;
+
+	if (IS_ERR(req))
+		return ERR_CAST(req);
+
+	if (set && atomic_read(&req->state) != MEDIA_REQUEST_STATE_IDLE) {
+		media_request_put(req);
+		return ERR_PTR(-EBUSY);
+	}
+
+	obj = media_request_object_find(req, &req_ops, hdl);
+	if (obj) {
+		media_request_put(req);
+		return obj;
+	}
+
+	new_hdl = kzalloc(sizeof(*new_hdl), GFP_KERNEL);
+	if (!new_hdl) {
+		ret = -ENOMEM;
+		goto put;
+	}
+	obj = &new_hdl->req_obj;
+	ret = v4l2_ctrl_handler_init(new_hdl, (hdl->nr_of_buckets - 1) * 8);
+	if (!ret)
+		ret = v4l2_ctrl_request_bind(req, new_hdl, hdl);
+	if (!ret) {
+		media_request_object_get(obj);
+		media_request_put(req);
+		return obj;
+	}
+	kfree(new_hdl);
+
+put:
+	media_request_put(req);
+	return ERR_PTR(ret);
+}
+
+int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct media_device *mdev,
+		     struct v4l2_ext_controls *cs)
+{
+	struct media_request_object *obj = NULL;
+	int ret;
+
+	if (cs->which == V4L2_CTRL_WHICH_REQUEST_VAL) {
+		if (!mdev || cs->request_fd < 0)
+			return -EINVAL;
+		obj = v4l2_ctrls_find_req_obj(hdl, mdev, cs->request_fd, false);
+		if (IS_ERR(obj))
+			return PTR_ERR(obj);
+		hdl = container_of(obj, struct v4l2_ctrl_handler,
+				   req_obj);
+	}
+
+	ret = __v4l2_g_ext_ctrls(hdl, cs);
+
+	if (obj)
+		media_request_object_put(obj);
+	return ret;
+}
 EXPORT_SYMBOL(v4l2_g_ext_ctrls);
 
 /* Helper function to get a single control */
@@ -3389,9 +3457,9 @@ static void update_from_auto_cluster(struct v4l2_ctrl *master)
 }
 
 /* Try or try-and-set controls */
-static int try_set_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
-			     struct v4l2_ext_controls *cs,
-			     bool set)
+static int __try_set_ext_ctrls(struct v4l2_fh *fh,
+			       struct v4l2_ctrl_handler *hdl,
+			       struct v4l2_ext_controls *cs, bool set)
 {
 	struct v4l2_ctrl_helper helper[4];
 	struct v4l2_ctrl_helper *helpers = helper;
@@ -3504,16 +3572,45 @@ static int try_set_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
 	return ret;
 }
 
-int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs)
+static int try_set_ext_ctrls(struct v4l2_fh *fh,
+			     struct v4l2_ctrl_handler *hdl, struct media_device *mdev,
+			     struct v4l2_ext_controls *cs, bool set)
+{
+	struct media_request_object *obj = NULL;
+	int ret;
+
+	if (cs->which == V4L2_CTRL_WHICH_REQUEST_VAL) {
+		if (!mdev || cs->request_fd < 0)
+			return -EINVAL;
+		obj = v4l2_ctrls_find_req_obj(hdl, mdev, cs->request_fd, true);
+		if (IS_ERR(obj))
+			return PTR_ERR(obj);
+		if (atomic_read(&obj->req->state) != MEDIA_REQUEST_STATE_IDLE) {
+			media_request_object_put(obj);
+			return -EBUSY;
+		}
+		hdl = container_of(obj, struct v4l2_ctrl_handler,
+				   req_obj);
+	}
+
+	ret = __try_set_ext_ctrls(fh, hdl, cs, set);
+
+	if (obj)
+		media_request_object_put(obj);
+	return ret;
+}
+
+int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct media_device *mdev,
+		       struct v4l2_ext_controls *cs)
 {
-	return try_set_ext_ctrls(NULL, hdl, cs, false);
+	return try_set_ext_ctrls(NULL, hdl, mdev, cs, false);
 }
 EXPORT_SYMBOL(v4l2_try_ext_ctrls);
 
 int v4l2_s_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
-					struct v4l2_ext_controls *cs)
+		     struct media_device *mdev, struct v4l2_ext_controls *cs)
 {
-	return try_set_ext_ctrls(fh, hdl, cs, true);
+	return try_set_ext_ctrls(fh, hdl, mdev, cs, true);
 }
 EXPORT_SYMBOL(v4l2_s_ext_ctrls);
 
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index 9ce23e23c5bf..56741c4a48fc 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -2079,9 +2079,9 @@ static int v4l_g_ext_ctrls(const struct v4l2_ioctl_ops *ops,
 
 	p->error_idx = p->count;
 	if (vfh && vfh->ctrl_handler)
-		return v4l2_g_ext_ctrls(vfh->ctrl_handler, p);
+		return v4l2_g_ext_ctrls(vfh->ctrl_handler, vfd->v4l2_dev->mdev, p);
 	if (vfd->ctrl_handler)
-		return v4l2_g_ext_ctrls(vfd->ctrl_handler, p);
+		return v4l2_g_ext_ctrls(vfd->ctrl_handler, vfd->v4l2_dev->mdev, p);
 	if (ops->vidioc_g_ext_ctrls == NULL)
 		return -ENOTTY;
 	return check_ext_ctrls(p, 0) ? ops->vidioc_g_ext_ctrls(file, fh, p) :
@@ -2098,9 +2098,9 @@ static int v4l_s_ext_ctrls(const struct v4l2_ioctl_ops *ops,
 
 	p->error_idx = p->count;
 	if (vfh && vfh->ctrl_handler)
-		return v4l2_s_ext_ctrls(vfh, vfh->ctrl_handler, p);
+		return v4l2_s_ext_ctrls(vfh, vfh->ctrl_handler, vfd->v4l2_dev->mdev, p);
 	if (vfd->ctrl_handler)
-		return v4l2_s_ext_ctrls(NULL, vfd->ctrl_handler, p);
+		return v4l2_s_ext_ctrls(NULL, vfd->ctrl_handler, vfd->v4l2_dev->mdev, p);
 	if (ops->vidioc_s_ext_ctrls == NULL)
 		return -ENOTTY;
 	return check_ext_ctrls(p, 0) ? ops->vidioc_s_ext_ctrls(file, fh, p) :
@@ -2117,9 +2117,9 @@ static int v4l_try_ext_ctrls(const struct v4l2_ioctl_ops *ops,
 
 	p->error_idx = p->count;
 	if (vfh && vfh->ctrl_handler)
-		return v4l2_try_ext_ctrls(vfh->ctrl_handler, p);
+		return v4l2_try_ext_ctrls(vfh->ctrl_handler, vfd->v4l2_dev->mdev, p);
 	if (vfd->ctrl_handler)
-		return v4l2_try_ext_ctrls(vfd->ctrl_handler, p);
+		return v4l2_try_ext_ctrls(vfd->ctrl_handler, vfd->v4l2_dev->mdev, p);
 	if (ops->vidioc_try_ext_ctrls == NULL)
 		return -ENOTTY;
 	return check_ext_ctrls(p, 0) ? ops->vidioc_try_ext_ctrls(file, fh, p) :
diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
index f9eed938d348..ce8c133e0ccd 100644
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -222,17 +222,20 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg)
 	case VIDIOC_G_EXT_CTRLS:
 		if (!vfh->ctrl_handler)
 			return -ENOTTY;
-		return v4l2_g_ext_ctrls(vfh->ctrl_handler, arg);
+		return v4l2_g_ext_ctrls(vfh->ctrl_handler,
+					sd->v4l2_dev->mdev, arg);
 
 	case VIDIOC_S_EXT_CTRLS:
 		if (!vfh->ctrl_handler)
 			return -ENOTTY;
-		return v4l2_s_ext_ctrls(vfh, vfh->ctrl_handler, arg);
+		return v4l2_s_ext_ctrls(vfh, vfh->ctrl_handler,
+					sd->v4l2_dev->mdev, arg);
 
 	case VIDIOC_TRY_EXT_CTRLS:
 		if (!vfh->ctrl_handler)
 			return -ENOTTY;
-		return v4l2_try_ext_ctrls(vfh->ctrl_handler, arg);
+		return v4l2_try_ext_ctrls(vfh->ctrl_handler,
+					  sd->v4l2_dev->mdev, arg);
 
 	case VIDIOC_DQEVENT:
 		if (!(sd->flags & V4L2_SUBDEV_FL_HAS_EVENTS))
diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
index a0f7c38d1a90..963c37b02363 100644
--- a/include/media/v4l2-ctrls.h
+++ b/include/media/v4l2-ctrls.h
@@ -1148,11 +1148,12 @@ int v4l2_s_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
  *	:ref:`VIDIOC_G_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
  *
  * @hdl: pointer to &struct v4l2_ctrl_handler
+ * @mdev: pointer to &struct media_device
  * @c: pointer to &struct v4l2_ext_controls
  *
  * If hdl == NULL then they will all return -EINVAL.
  */
-int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl,
+int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct media_device *mdev,
 		     struct v4l2_ext_controls *c);
 
 /**
@@ -1160,11 +1161,13 @@ int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl,
  *	:ref:`VIDIOC_TRY_EXT_CTRLS <vidioc_g_ext_ctrls>` ioctl
  *
  * @hdl: pointer to &struct v4l2_ctrl_handler
+ * @mdev: pointer to &struct media_device
  * @c: pointer to &struct v4l2_ext_controls
  *
  * If hdl == NULL then they will all return -EINVAL.
  */
 int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl,
+		       struct media_device *mdev,
 		       struct v4l2_ext_controls *c);
 
 /**
@@ -1173,11 +1176,13 @@ int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl,
  *
  * @fh: pointer to &struct v4l2_fh
  * @hdl: pointer to &struct v4l2_ctrl_handler
+ * @mdev: pointer to &struct media_device
  * @c: pointer to &struct v4l2_ext_controls
  *
  * If hdl == NULL then they will all return -EINVAL.
  */
 int v4l2_s_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
+		     struct media_device *mdev,
 		     struct v4l2_ext_controls *c);
 
 /**
-- 
2.17.0

[RFCv12 PATCH 14/29] videodev2.h: Add request_fd field to v4l2_buffer

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

When queuing buffers allow for passing the request that should
be associated with this buffer.

If V4L2_BUF_FLAG_REQUEST_FD is set, then request_fd is used as
the file descriptor.

If a buffer is stored in a request, but not yet queued to the
driver, then V4L2_BUF_FLAG_IN_REQUEST is set.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/common/videobuf2/videobuf2-v4l2.c |  2 +-
 drivers/media/usb/cpia2/cpia2_v4l.c             |  2 +-
 drivers/media/v4l2-core/v4l2-compat-ioctl32.c   |  9 ++++++---
 drivers/media/v4l2-core/v4l2-ioctl.c            |  4 ++--
 include/uapi/linux/videodev2.h                  | 10 +++++++++-
 5 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index 886a2d8d5c6c..4e9c77f21858 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -204,7 +204,7 @@ static void __fill_v4l2_buffer(struct vb2_buffer *vb, void *pb)
 	b->timecode = vbuf->timecode;
 	b->sequence = vbuf->sequence;
 	b->reserved2 = 0;
-	b->reserved = 0;
+	b->request_fd = 0;
 
 	if (q->is_multiplanar) {
 		/*
diff --git a/drivers/media/usb/cpia2/cpia2_v4l.c b/drivers/media/usb/cpia2/cpia2_v4l.c
index 99f106b13280..13aee9f67d05 100644
--- a/drivers/media/usb/cpia2/cpia2_v4l.c
+++ b/drivers/media/usb/cpia2/cpia2_v4l.c
@@ -949,7 +949,7 @@ static int cpia2_dqbuf(struct file *file, void *fh, struct v4l2_buffer *buf)
 	buf->m.offset = cam->buffers[buf->index].data - cam->frame_buffer;
 	buf->length = cam->frame_size;
 	buf->reserved2 = 0;
-	buf->reserved = 0;
+	buf->request_fd = 0;
 	memset(&buf->timecode, 0, sizeof(buf->timecode));
 
 	DBG("DQBUF #%d status:%d seq:%d length:%d\n", buf->index,
diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
index dcce86c1fe40..633465d21d04 100644
--- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
+++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
@@ -482,7 +482,7 @@ struct v4l2_buffer32 {
 	} m;
 	__u32			length;
 	__u32			reserved2;
-	__u32			reserved;
+	__s32			request_fd;
 };
 
 static int get_v4l2_plane32(struct v4l2_plane __user *p64,
@@ -581,6 +581,7 @@ static int get_v4l2_buffer32(struct v4l2_buffer __user *p64,
 {
 	u32 type;
 	u32 length;
+	s32 request_fd;
 	enum v4l2_memory memory;
 	struct v4l2_plane32 __user *uplane32;
 	struct v4l2_plane __user *uplane;
@@ -595,7 +596,9 @@ static int get_v4l2_buffer32(struct v4l2_buffer __user *p64,
 	    get_user(memory, &p32->memory) ||
 	    put_user(memory, &p64->memory) ||
 	    get_user(length, &p32->length) ||
-	    put_user(length, &p64->length))
+	    put_user(length, &p64->length) ||
+	    get_user(request_fd, &p32->request_fd) ||
+	    put_user(request_fd, &p64->request_fd))
 		return -EFAULT;
 
 	if (V4L2_TYPE_IS_OUTPUT(type))
@@ -699,7 +702,7 @@ static int put_v4l2_buffer32(struct v4l2_buffer __user *p64,
 	    copy_in_user(&p32->timecode, &p64->timecode, sizeof(p64->timecode)) ||
 	    assign_in_user(&p32->sequence, &p64->sequence) ||
 	    assign_in_user(&p32->reserved2, &p64->reserved2) ||
-	    assign_in_user(&p32->reserved, &p64->reserved) ||
+	    assign_in_user(&p32->request_fd, &p64->request_fd) ||
 	    get_user(length, &p64->length) ||
 	    put_user(length, &p32->length))
 		return -EFAULT;
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index 56741c4a48fc..561a1fe3160b 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -437,13 +437,13 @@ static void v4l_print_buffer(const void *arg, bool write_only)
 	const struct v4l2_plane *plane;
 	int i;
 
-	pr_cont("%02ld:%02d:%02d.%08ld index=%d, type=%s, flags=0x%08x, field=%s, sequence=%d, memory=%s",
+	pr_cont("%02ld:%02d:%02d.%08ld index=%d, type=%s, request_fd=%d, flags=0x%08x, field=%s, sequence=%d, memory=%s",
 			p->timestamp.tv_sec / 3600,
 			(int)(p->timestamp.tv_sec / 60) % 60,
 			(int)(p->timestamp.tv_sec % 60),
 			(long)p->timestamp.tv_usec,
 			p->index,
-			prt_names(p->type, v4l2_type_names),
+			prt_names(p->type, v4l2_type_names), p->request_fd,
 			p->flags, prt_names(p->field, v4l2_field_names),
 			p->sequence, prt_names(p->memory, v4l2_memory_names));
 
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 16b53b82496c..1f6c4b52baae 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -910,6 +910,7 @@ struct v4l2_plane {
  * @length:	size in bytes of the buffer (NOT its payload) for single-plane
  *		buffers (when type != *_MPLANE); number of elements in the
  *		planes array for multi-plane buffers
+ * @request_fd: fd of the request that this buffer should use
  *
  * Contains data exchanged by application and driver using one of the Streaming
  * I/O methods.
@@ -934,7 +935,10 @@ struct v4l2_buffer {
 	} m;
 	__u32			length;
 	__u32			reserved2;
-	__u32			reserved;
+	union {
+		__s32		request_fd;
+		__u32		reserved;
+	};
 };
 
 /*  Flags for 'flags' field */
@@ -952,6 +956,8 @@ struct v4l2_buffer {
 #define V4L2_BUF_FLAG_BFRAME			0x00000020
 /* Buffer is ready, but the data contained within is corrupted. */
 #define V4L2_BUF_FLAG_ERROR			0x00000040
+/* Buffer is added to an unqueued request */
+#define V4L2_BUF_FLAG_IN_REQUEST		0x00000080
 /* timecode field is valid */
 #define V4L2_BUF_FLAG_TIMECODE			0x00000100
 /* Buffer is prepared for queuing */
@@ -970,6 +976,8 @@ struct v4l2_buffer {
 #define V4L2_BUF_FLAG_TSTAMP_SRC_SOE		0x00010000
 /* mem2mem encoder/decoder */
 #define V4L2_BUF_FLAG_LAST			0x00100000
+/* request_fd is valid */
+#define V4L2_BUF_FLAG_REQUEST_FD		0x00800000
 
 /**
  * struct v4l2_exportbuffer - export of video buffer as DMABUF file descriptor
-- 
2.17.0

[RFCv12 PATCH 15/29] vb2: store userspace data in vb2_v4l2_buffer

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

The userspace-provided plane data needs to be stored in
vb2_v4l2_buffer. Currently this information is applied by
__fill_vb2_buffer() which is called by the core prepare_buf
and qbuf functions, but when using requests these functions
aren't called yet since the buffer won't be prepared until
the media request is actually queued.

In the meantime this information has to be stored somewhere
and vb2_v4l2_buffer is a good place for it.

The __fill_vb2_buffer callback now just copies the relevant
information from vb2_v4l2_buffer into the planes array.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 .../media/common/videobuf2/videobuf2-core.c   |  43 +--
 .../media/common/videobuf2/videobuf2-v4l2.c   | 324 ++++++++++--------
 drivers/media/dvb-core/dvb_vb2.c              |   3 +-
 include/media/videobuf2-core.h                |   3 +-
 include/media/videobuf2-v4l2.h                |   2 +
 5 files changed, 206 insertions(+), 169 deletions(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index d3f7bb33a54d..70ba43c5b3e2 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -964,20 +964,19 @@ EXPORT_SYMBOL_GPL(vb2_discard_done);
 /*
  * __prepare_mmap() - prepare an MMAP buffer
  */
-static int __prepare_mmap(struct vb2_buffer *vb, const void *pb)
+static int __prepare_mmap(struct vb2_buffer *vb)
 {
 	int ret = 0;
 
-	if (pb)
-		ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
-				 vb, pb, vb->planes);
+	ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
+			 vb, vb->planes);
 	return ret ? ret : call_vb_qop(vb, buf_prepare, vb);
 }
 
 /*
  * __prepare_userptr() - prepare a USERPTR buffer
  */
-static int __prepare_userptr(struct vb2_buffer *vb, const void *pb)
+static int __prepare_userptr(struct vb2_buffer *vb)
 {
 	struct vb2_plane planes[VB2_MAX_PLANES];
 	struct vb2_queue *q = vb->vb2_queue;
@@ -988,12 +987,10 @@ static int __prepare_userptr(struct vb2_buffer *vb, const void *pb)
 
 	memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
 	/* Copy relevant information provided by the userspace */
-	if (pb) {
-		ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
-				 vb, pb, planes);
-		if (ret)
-			return ret;
-	}
+	ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
+			 vb, planes);
+	if (ret)
+		return ret;
 
 	for (plane = 0; plane < vb->num_planes; ++plane) {
 		/* Skip the plane if already verified */
@@ -1093,7 +1090,7 @@ static int __prepare_userptr(struct vb2_buffer *vb, const void *pb)
 /*
  * __prepare_dmabuf() - prepare a DMABUF buffer
  */
-static int __prepare_dmabuf(struct vb2_buffer *vb, const void *pb)
+static int __prepare_dmabuf(struct vb2_buffer *vb)
 {
 	struct vb2_plane planes[VB2_MAX_PLANES];
 	struct vb2_queue *q = vb->vb2_queue;
@@ -1104,12 +1101,10 @@ static int __prepare_dmabuf(struct vb2_buffer *vb, const void *pb)
 
 	memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
 	/* Copy relevant information provided by the userspace */
-	if (pb) {
-		ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
-				 vb, pb, planes);
-		if (ret)
-			return ret;
-	}
+	ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
+			 vb, planes);
+	if (ret)
+		return ret;
 
 	for (plane = 0; plane < vb->num_planes; ++plane) {
 		struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
@@ -1238,7 +1233,7 @@ static void __enqueue_in_driver(struct vb2_buffer *vb)
 	call_void_vb_qop(vb, buf_queue, vb);
 }
 
-static int __buf_prepare(struct vb2_buffer *vb, const void *pb)
+static int __buf_prepare(struct vb2_buffer *vb)
 {
 	struct vb2_queue *q = vb->vb2_queue;
 	unsigned int plane;
@@ -1253,13 +1248,13 @@ static int __buf_prepare(struct vb2_buffer *vb, const void *pb)
 
 	switch (q->memory) {
 	case VB2_MEMORY_MMAP:
-		ret = __prepare_mmap(vb, pb);
+		ret = __prepare_mmap(vb);
 		break;
 	case VB2_MEMORY_USERPTR:
-		ret = __prepare_userptr(vb, pb);
+		ret = __prepare_userptr(vb);
 		break;
 	case VB2_MEMORY_DMABUF:
-		ret = __prepare_dmabuf(vb, pb);
+		ret = __prepare_dmabuf(vb);
 		break;
 	default:
 		WARN(1, "Invalid queue type\n");
@@ -1293,7 +1288,7 @@ int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
 		return -EINVAL;
 	}
 
-	ret = __buf_prepare(vb, pb);
+	ret = __buf_prepare(vb);
 	if (ret)
 		return ret;
 
@@ -1378,7 +1373,7 @@ int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb)
 
 	switch (vb->state) {
 	case VB2_BUF_STATE_DEQUEUED:
-		ret = __buf_prepare(vb, pb);
+		ret = __buf_prepare(vb);
 		if (ret)
 			return ret;
 		break;
diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index 4e9c77f21858..bf7a3ba9fed0 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -154,9 +154,177 @@ static void vb2_warn_zero_bytesused(struct vb2_buffer *vb)
 		pr_warn("use the actual size instead.\n");
 }
 
+static int vb2_fill_vb2_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
+{
+	struct vb2_queue *q = vb->vb2_queue;
+	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+	struct vb2_plane *planes = vbuf->planes;
+	unsigned int plane;
+	int ret;
+
+	ret = __verify_length(vb, b);
+	if (ret < 0) {
+		dprintk(1, "plane parameters verification failed: %d\n", ret);
+		return ret;
+	}
+	if (b->field == V4L2_FIELD_ALTERNATE && q->is_output) {
+		/*
+		 * If the format's field is ALTERNATE, then the buffer's field
+		 * should be either TOP or BOTTOM, not ALTERNATE since that
+		 * makes no sense. The driver has to know whether the
+		 * buffer represents a top or a bottom field in order to
+		 * program any DMA correctly. Using ALTERNATE is wrong, since
+		 * that just says that it is either a top or a bottom field,
+		 * but not which of the two it is.
+		 */
+		dprintk(1, "the field is incorrectly set to ALTERNATE for an output buffer\n");
+		return -EINVAL;
+	}
+	vbuf->sequence = 0;
+
+	if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
+		switch (b->memory) {
+		case VB2_MEMORY_USERPTR:
+			for (plane = 0; plane < vb->num_planes; ++plane) {
+				planes[plane].m.userptr =
+					b->m.planes[plane].m.userptr;
+				planes[plane].length =
+					b->m.planes[plane].length;
+			}
+			break;
+		case VB2_MEMORY_DMABUF:
+			for (plane = 0; plane < vb->num_planes; ++plane) {
+				planes[plane].m.fd =
+					b->m.planes[plane].m.fd;
+				planes[plane].length =
+					b->m.planes[plane].length;
+			}
+			break;
+		default:
+			for (plane = 0; plane < vb->num_planes; ++plane) {
+				planes[plane].m.offset =
+					vb->planes[plane].m.offset;
+				planes[plane].length =
+					vb->planes[plane].length;
+			}
+			break;
+		}
+
+		/* Fill in driver-provided information for OUTPUT types */
+		if (V4L2_TYPE_IS_OUTPUT(b->type)) {
+			/*
+			 * Will have to go up to b->length when API starts
+			 * accepting variable number of planes.
+			 *
+			 * If bytesused == 0 for the output buffer, then fall
+			 * back to the full buffer size. In that case
+			 * userspace clearly never bothered to set it and
+			 * it's a safe assumption that they really meant to
+			 * use the full plane sizes.
+			 *
+			 * Some drivers, e.g. old codec drivers, use bytesused == 0
+			 * as a way to indicate that streaming is finished.
+			 * In that case, the driver should use the
+			 * allow_zero_bytesused flag to keep old userspace
+			 * applications working.
+			 */
+			for (plane = 0; plane < vb->num_planes; ++plane) {
+				struct vb2_plane *pdst = &planes[plane];
+				struct v4l2_plane *psrc = &b->m.planes[plane];
+
+				if (psrc->bytesused == 0)
+					vb2_warn_zero_bytesused(vb);
+
+				if (vb->vb2_queue->allow_zero_bytesused)
+					pdst->bytesused = psrc->bytesused;
+				else
+					pdst->bytesused = psrc->bytesused ?
+						psrc->bytesused : pdst->length;
+				pdst->data_offset = psrc->data_offset;
+			}
+		}
+	} else {
+		/*
+		 * Single-planar buffers do not use planes array,
+		 * so fill in relevant v4l2_buffer struct fields instead.
+		 * In videobuf we use our internal V4l2_planes struct for
+		 * single-planar buffers as well, for simplicity.
+		 *
+		 * If bytesused == 0 for the output buffer, then fall back
+		 * to the full buffer size as that's a sensible default.
+		 *
+		 * Some drivers, e.g. old codec drivers, use bytesused == 0 as
+		 * a way to indicate that streaming is finished. In that case,
+		 * the driver should use the allow_zero_bytesused flag to keep
+		 * old userspace applications working.
+		 */
+		switch (b->memory) {
+		case VB2_MEMORY_USERPTR:
+			planes[0].m.userptr = b->m.userptr;
+			planes[0].length = b->length;
+			break;
+		case VB2_MEMORY_DMABUF:
+			planes[0].m.fd = b->m.fd;
+			planes[0].length = b->length;
+			break;
+		default:
+			planes[0].m.offset = vb->planes[0].m.offset;
+			planes[0].length = vb->planes[0].length;
+			break;
+		}
+
+		planes[0].data_offset = 0;
+		if (V4L2_TYPE_IS_OUTPUT(b->type)) {
+			if (b->bytesused == 0)
+				vb2_warn_zero_bytesused(vb);
+
+			if (vb->vb2_queue->allow_zero_bytesused)
+				planes[0].bytesused = b->bytesused;
+			else
+				planes[0].bytesused = b->bytesused ?
+					b->bytesused : planes[0].length;
+		} else
+			planes[0].bytesused = 0;
+
+	}
+
+	/* Zero flags that we handle */
+	vbuf->flags = b->flags & ~V4L2_BUFFER_MASK_FLAGS;
+	if (!vb->vb2_queue->copy_timestamp || !V4L2_TYPE_IS_OUTPUT(b->type)) {
+		/*
+		 * Non-COPY timestamps and non-OUTPUT queues will get
+		 * their timestamp and timestamp source flags from the
+		 * queue.
+		 */
+		vbuf->flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
+	}
+
+	if (V4L2_TYPE_IS_OUTPUT(b->type)) {
+		/*
+		 * For output buffers mask out the timecode flag:
+		 * this will be handled later in vb2_qbuf().
+		 * The 'field' is valid metadata for this output buffer
+		 * and so that needs to be copied here.
+		 */
+		vbuf->flags &= ~V4L2_BUF_FLAG_TIMECODE;
+		vbuf->field = b->field;
+	} else {
+		/* Zero any output buffer flags as this is a capture buffer */
+		vbuf->flags &= ~V4L2_BUFFER_OUT_FLAGS;
+		/* Zero last flag, this is a signal from driver to userspace */
+		vbuf->flags &= ~V4L2_BUF_FLAG_LAST;
+	}
+
+	return 0;
+}
+
 static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
 				    const char *opname)
 {
+	struct vb2_v4l2_buffer *vbuf;
+	struct vb2_buffer *vb;
+	int ret;
+
 	if (b->type != q->type) {
 		dprintk(1, "%s: invalid buffer type\n", opname);
 		return -EINVAL;
@@ -178,7 +346,15 @@ static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
 		return -EINVAL;
 	}
 
-	return __verify_planes_array(q->bufs[b->index], b);
+	vb = q->bufs[b->index];
+	vbuf = to_vb2_v4l2_buffer(vb);
+	ret = __verify_planes_array(vb, b);
+	if (ret)
+		return ret;
+
+	/* Copy relevant information provided by the userspace */
+	memset(vbuf->planes, 0, sizeof(vbuf->planes[0]) * vb->num_planes);
+	return vb2_fill_vb2_v4l2_buffer(vb, b);
 }
 
 /*
@@ -291,153 +467,19 @@ static void __fill_v4l2_buffer(struct vb2_buffer *vb, void *pb)
  * v4l2_buffer by the userspace. It also verifies that struct
  * v4l2_buffer has a valid number of planes.
  */
-static int __fill_vb2_buffer(struct vb2_buffer *vb,
-		const void *pb, struct vb2_plane *planes)
+static int __fill_vb2_buffer(struct vb2_buffer *vb, struct vb2_plane *planes)
 {
-	struct vb2_queue *q = vb->vb2_queue;
-	const struct v4l2_buffer *b = pb;
 	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
 	unsigned int plane;
-	int ret;
 
-	ret = __verify_length(vb, b);
-	if (ret < 0) {
-		dprintk(1, "plane parameters verification failed: %d\n", ret);
-		return ret;
-	}
-	if (b->field == V4L2_FIELD_ALTERNATE && q->is_output) {
-		/*
-		 * If the format's field is ALTERNATE, then the buffer's field
-		 * should be either TOP or BOTTOM, not ALTERNATE since that
-		 * makes no sense. The driver has to know whether the
-		 * buffer represents a top or a bottom field in order to
-		 * program any DMA correctly. Using ALTERNATE is wrong, since
-		 * that just says that it is either a top or a bottom field,
-		 * but not which of the two it is.
-		 */
-		dprintk(1, "the field is incorrectly set to ALTERNATE for an output buffer\n");
-		return -EINVAL;
-	}
 	vb->timestamp = 0;
-	vbuf->sequence = 0;
-
-	if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
-		if (b->memory == VB2_MEMORY_USERPTR) {
-			for (plane = 0; plane < vb->num_planes; ++plane) {
-				planes[plane].m.userptr =
-					b->m.planes[plane].m.userptr;
-				planes[plane].length =
-					b->m.planes[plane].length;
-			}
-		}
-		if (b->memory == VB2_MEMORY_DMABUF) {
-			for (plane = 0; plane < vb->num_planes; ++plane) {
-				planes[plane].m.fd =
-					b->m.planes[plane].m.fd;
-				planes[plane].length =
-					b->m.planes[plane].length;
-			}
-		}
-
-		/* Fill in driver-provided information for OUTPUT types */
-		if (V4L2_TYPE_IS_OUTPUT(b->type)) {
-			/*
-			 * Will have to go up to b->length when API starts
-			 * accepting variable number of planes.
-			 *
-			 * If bytesused == 0 for the output buffer, then fall
-			 * back to the full buffer size. In that case
-			 * userspace clearly never bothered to set it and
-			 * it's a safe assumption that they really meant to
-			 * use the full plane sizes.
-			 *
-			 * Some drivers, e.g. old codec drivers, use bytesused == 0
-			 * as a way to indicate that streaming is finished.
-			 * In that case, the driver should use the
-			 * allow_zero_bytesused flag to keep old userspace
-			 * applications working.
-			 */
-			for (plane = 0; plane < vb->num_planes; ++plane) {
-				struct vb2_plane *pdst = &planes[plane];
-				struct v4l2_plane *psrc = &b->m.planes[plane];
-
-				if (psrc->bytesused == 0)
-					vb2_warn_zero_bytesused(vb);
 
-				if (vb->vb2_queue->allow_zero_bytesused)
-					pdst->bytesused = psrc->bytesused;
-				else
-					pdst->bytesused = psrc->bytesused ?
-						psrc->bytesused : pdst->length;
-				pdst->data_offset = psrc->data_offset;
-			}
-		}
-	} else {
-		/*
-		 * Single-planar buffers do not use planes array,
-		 * so fill in relevant v4l2_buffer struct fields instead.
-		 * In videobuf we use our internal V4l2_planes struct for
-		 * single-planar buffers as well, for simplicity.
-		 *
-		 * If bytesused == 0 for the output buffer, then fall back
-		 * to the full buffer size as that's a sensible default.
-		 *
-		 * Some drivers, e.g. old codec drivers, use bytesused == 0 as
-		 * a way to indicate that streaming is finished. In that case,
-		 * the driver should use the allow_zero_bytesused flag to keep
-		 * old userspace applications working.
-		 */
-		if (b->memory == VB2_MEMORY_USERPTR) {
-			planes[0].m.userptr = b->m.userptr;
-			planes[0].length = b->length;
-		}
-
-		if (b->memory == VB2_MEMORY_DMABUF) {
-			planes[0].m.fd = b->m.fd;
-			planes[0].length = b->length;
-		}
-
-		if (V4L2_TYPE_IS_OUTPUT(b->type)) {
-			if (b->bytesused == 0)
-				vb2_warn_zero_bytesused(vb);
-
-			if (vb->vb2_queue->allow_zero_bytesused)
-				planes[0].bytesused = b->bytesused;
-			else
-				planes[0].bytesused = b->bytesused ?
-					b->bytesused : planes[0].length;
-		} else
-			planes[0].bytesused = 0;
-
-	}
-
-	/* Zero flags that the vb2 core handles */
-	vbuf->flags = b->flags & ~V4L2_BUFFER_MASK_FLAGS;
-	if (!vb->vb2_queue->copy_timestamp || !V4L2_TYPE_IS_OUTPUT(b->type)) {
-		/*
-		 * Non-COPY timestamps and non-OUTPUT queues will get
-		 * their timestamp and timestamp source flags from the
-		 * queue.
-		 */
-		vbuf->flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
+	for (plane = 0; plane < vb->num_planes; ++plane) {
+		planes[plane].m = vbuf->planes[plane].m;
+		planes[plane].length = vbuf->planes[plane].length;
+		planes[plane].bytesused = vbuf->planes[plane].bytesused;
+		planes[plane].data_offset = vbuf->planes[plane].data_offset;
 	}
-
-	if (V4L2_TYPE_IS_OUTPUT(b->type)) {
-		/*
-		 * For output buffers mask out the timecode flag:
-		 * this will be handled later in vb2_qbuf().
-		 * The 'field' is valid metadata for this output buffer
-		 * and so that needs to be copied here.
-		 */
-		vbuf->flags &= ~V4L2_BUF_FLAG_TIMECODE;
-		vbuf->field = b->field;
-	} else {
-		/* Zero any output buffer flags as this is a capture buffer */
-		vbuf->flags &= ~V4L2_BUFFER_OUT_FLAGS;
-		/* Zero last flag, this is a signal from driver to userspace */
-		vbuf->flags &= ~V4L2_BUF_FLAG_LAST;
-	}
-
 	return 0;
 }
 
diff --git a/drivers/media/dvb-core/dvb_vb2.c b/drivers/media/dvb-core/dvb_vb2.c
index b811adf88afa..da6a8cec7d42 100644
--- a/drivers/media/dvb-core/dvb_vb2.c
+++ b/drivers/media/dvb-core/dvb_vb2.c
@@ -146,8 +146,7 @@ static void _fill_dmx_buffer(struct vb2_buffer *vb, void *pb)
 	dprintk(3, "[%s]\n", ctx->name);
 }
 
-static int _fill_vb2_buffer(struct vb2_buffer *vb,
-			    const void *pb, struct vb2_plane *planes)
+static int _fill_vb2_buffer(struct vb2_buffer *vb, struct vb2_plane *planes)
 {
 	struct dvb_vb2_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
 
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index f6818f732f34..224c4820a044 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -417,8 +417,7 @@ struct vb2_ops {
 struct vb2_buf_ops {
 	int (*verify_planes_array)(struct vb2_buffer *vb, const void *pb);
 	void (*fill_user_buffer)(struct vb2_buffer *vb, void *pb);
-	int (*fill_vb2_buffer)(struct vb2_buffer *vb, const void *pb,
-				struct vb2_plane *planes);
+	int (*fill_vb2_buffer)(struct vb2_buffer *vb, struct vb2_plane *planes);
 	void (*copy_timestamp)(struct vb2_buffer *vb, const void *pb);
 };
 
diff --git a/include/media/videobuf2-v4l2.h b/include/media/videobuf2-v4l2.h
index 3d5e2d739f05..097bf3e6951d 100644
--- a/include/media/videobuf2-v4l2.h
+++ b/include/media/videobuf2-v4l2.h
@@ -32,6 +32,7 @@
  *		&enum v4l2_field.
  * @timecode:	frame timecode.
  * @sequence:	sequence count of this frame.
+ * @planes:	plane information (userptr/fd, length, bytesused, data_offset).
  *
  * Should contain enough information to be able to cover all the fields
  * of &struct v4l2_buffer at ``videodev2.h``.
@@ -43,6 +44,7 @@ struct vb2_v4l2_buffer {
 	__u32			field;
 	struct v4l2_timecode	timecode;
 	__u32			sequence;
+	struct vb2_plane	planes[VB2_MAX_PLANES];
 };
 
 /*
-- 
2.17.0

[RFCv12 PATCH 16/29] videobuf2-core: embed media_request_object

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

Make vb2_buffer a request object.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 include/media/videobuf2-core.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index 224c4820a044..3d54654c3cd4 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -17,6 +17,7 @@
 #include <linux/poll.h>
 #include <linux/dma-buf.h>
 #include <linux/bitops.h>
+#include <media/media-request.h>
 
 #define VB2_MAX_FRAME	(32)
 #define VB2_MAX_PLANES	(8)
@@ -238,6 +239,7 @@ struct vb2_queue;
  * @num_planes:		number of planes in the buffer
  *			on an internal driver queue.
  * @timestamp:		frame timestamp in ns.
+ * @req_obj:		used to bind this buffer to a request
  */
 struct vb2_buffer {
 	struct vb2_queue	*vb2_queue;
@@ -246,6 +248,7 @@ struct vb2_buffer {
 	unsigned int		memory;
 	unsigned int		num_planes;
 	u64			timestamp;
+	struct media_request_object	req_obj;
 
 	/* private: internal use only
 	 *
-- 
2.17.0

[RFCv12 PATCH 17/29] videobuf2-core: integrate with media requests

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

Buffers can now be prepared or queued for a request.

A buffer is unbound from the request at vb2_buffer_done time or
when the queue is cancelled.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 .../media/common/videobuf2/videobuf2-core.c   | 146 ++++++++++++++++--
 .../media/common/videobuf2/videobuf2-v4l2.c   |   4 +-
 drivers/media/dvb-core/dvb_vb2.c              |   2 +-
 include/media/videobuf2-core.h                |  17 +-
 4 files changed, 152 insertions(+), 17 deletions(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index 70ba43c5b3e2..31b86bfa52bd 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -930,6 +930,14 @@ void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
 		vb->state = state;
 	}
 	atomic_dec(&q->owned_by_drv_count);
+
+	if (vb->req_obj.req) {
+		/* This is not supported at the moment */
+		WARN_ON(state == VB2_BUF_STATE_REQUEUEING);
+		media_request_object_unbind(&vb->req_obj);
+		media_request_object_put(&vb->req_obj);
+	}
+
 	spin_unlock_irqrestore(&q->done_lock, flags);
 
 	trace_vb2_buf_done(q, vb);
@@ -1236,6 +1244,7 @@ static void __enqueue_in_driver(struct vb2_buffer *vb)
 static int __buf_prepare(struct vb2_buffer *vb)
 {
 	struct vb2_queue *q = vb->vb2_queue;
+	enum vb2_buffer_state orig_state = vb->state;
 	unsigned int plane;
 	int ret;
 
@@ -1263,7 +1272,7 @@ static int __buf_prepare(struct vb2_buffer *vb)
 
 	if (ret) {
 		dprintk(1, "buffer preparation failed: %d\n", ret);
-		vb->state = VB2_BUF_STATE_DEQUEUED;
+		vb->state = orig_state;
 		return ret;
 	}
 
@@ -1276,11 +1285,70 @@ static int __buf_prepare(struct vb2_buffer *vb)
 	return 0;
 }
 
-int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
+static int vb2_req_prepare(struct media_request_object *obj)
 {
-	struct vb2_buffer *vb;
+	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
 	int ret;
 
+	if (WARN_ON(vb->state != VB2_BUF_STATE_IN_REQUEST))
+		return -EINVAL;
+
+	mutex_lock(vb->vb2_queue->lock);
+	ret = __buf_prepare(vb);
+	mutex_unlock(vb->vb2_queue->lock);
+	return ret;
+}
+
+static void __vb2_dqbuf(struct vb2_buffer *vb);
+static void vb2_req_unprepare(struct media_request_object *obj)
+{
+	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
+
+	mutex_lock(vb->vb2_queue->lock);
+	__vb2_dqbuf(vb);
+	vb->state = VB2_BUF_STATE_IN_REQUEST;
+	mutex_unlock(vb->vb2_queue->lock);
+	WARN_ON(!vb->req_obj.req);
+}
+
+int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
+		  struct media_request *req);
+
+static void vb2_req_queue(struct media_request_object *obj)
+{
+	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
+
+	mutex_lock(vb->vb2_queue->lock);
+	vb2_core_qbuf(vb->vb2_queue, vb->index, NULL, NULL);
+	mutex_unlock(vb->vb2_queue->lock);
+}
+
+static void vb2_req_release(struct media_request_object *obj)
+{
+	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
+
+	if (vb->state == VB2_BUF_STATE_IN_REQUEST)
+		vb->state = VB2_BUF_STATE_DEQUEUED;
+}
+
+static void vb2_req_cancel(struct media_request_object *obj)
+{
+	/* Nothing to do here, buffers are cancelled in __vb2_queue_cancel() */
+}
+
+static const struct media_request_object_ops vb2_core_req_ops = {
+	.prepare = vb2_req_prepare,
+	.unprepare = vb2_req_unprepare,
+	.queue = vb2_req_queue,
+	.cancel = vb2_req_cancel,
+	.release = vb2_req_release,
+};
+
+int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb,
+			 struct media_request *req)
+{
+	struct vb2_buffer *vb;
+
 	vb = q->bufs[index];
 	if (vb->state != VB2_BUF_STATE_DEQUEUED) {
 		dprintk(1, "invalid buffer state %d\n",
@@ -1288,16 +1356,36 @@ int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
 		return -EINVAL;
 	}
 
-	ret = __buf_prepare(vb);
-	if (ret)
-		return ret;
+	if (req) {
+		int ret;
+
+		media_request_object_init(&vb->req_obj);
+		/*
+		 * Note: the bind function checks if the request is in
+		 * IDLE state and returns an error if it isn't. It uses
+		 * the req->lock spinlock and so we do not need to take
+		 * the media_device req_queue_mutex here in order to
+		 * prevent a race condition with the QUEUE ioctl.
+		 */
+		ret = media_request_object_bind(req, &vb2_core_req_ops,
+						q, &vb->req_obj);
+		if (ret)
+			return ret;
+
+		vb->state = VB2_BUF_STATE_IN_REQUEST;
+	} else {
+		int ret = __buf_prepare(vb);
+
+		if (ret)
+			return ret;
+	}
 
 	/* Fill buffer information for the userspace */
 	call_void_bufop(q, fill_user_buffer, vb, pb);
 
 	dprintk(2, "prepare of buffer %d succeeded\n", vb->index);
 
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL_GPL(vb2_core_prepare_buf);
 
@@ -1364,13 +1452,39 @@ static int vb2_start_streaming(struct vb2_queue *q)
 	return ret;
 }
 
-int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb)
+int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
+		  struct media_request *req)
 {
 	struct vb2_buffer *vb;
 	int ret;
 
 	vb = q->bufs[index];
 
+	if (vb->state == VB2_BUF_STATE_DEQUEUED && req) {
+		int ret;
+
+		media_request_object_init(&vb->req_obj);
+		/*
+		 * Note: the bind function checks if the request is in
+		 * IDLE state and returns an error if it isn't. It uses
+		 * the req->lock spinlock and so we do not need to take
+		 * the media_device req_queue_mutex here in order to
+		 * prevent a race condition with the QUEUE ioctl.
+		 */
+		ret = media_request_object_bind(req, &vb2_core_req_ops,
+						q, &vb->req_obj);
+		if (ret)
+			return ret;
+
+		vb->state = VB2_BUF_STATE_IN_REQUEST;
+		/* Fill buffer information for the userspace */
+		if (pb)
+			call_void_bufop(q, fill_user_buffer, vb, pb);
+
+		dprintk(2, "qbuf of buffer %d succeeded\n", vb->index);
+		return 0;
+	}
+
 	switch (vb->state) {
 	case VB2_BUF_STATE_DEQUEUED:
 		ret = __buf_prepare(vb);
@@ -1578,6 +1692,10 @@ static void __vb2_dqbuf(struct vb2_buffer *vb)
 			call_void_memop(vb, unmap_dmabuf, vb->planes[i].mem_priv);
 			vb->planes[i].dbuf_mapped = 0;
 		}
+	if (vb->req_obj.req) {
+		media_request_object_unbind(&vb->req_obj);
+		media_request_object_put(&vb->req_obj);
+	}
 }
 
 int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
@@ -1691,6 +1809,9 @@ static void __vb2_queue_cancel(struct vb2_queue *q)
 	for (i = 0; i < q->num_buffers; ++i) {
 		struct vb2_buffer *vb = q->bufs[i];
 
+		if (vb->req_obj.req)
+			media_request_cancel(vb->req_obj.req);
+
 		if (vb->state == VB2_BUF_STATE_PREPARED ||
 		    vb->state == VB2_BUF_STATE_QUEUED) {
 			unsigned int plane;
@@ -1700,7 +1821,8 @@ static void __vb2_queue_cancel(struct vb2_queue *q)
 						vb->planes[plane].mem_priv);
 		}
 
-		if (vb->state != VB2_BUF_STATE_DEQUEUED) {
+		if (vb->state != VB2_BUF_STATE_DEQUEUED &&
+		    vb->state != VB2_BUF_STATE_IN_REQUEST) {
 			vb->state = VB2_BUF_STATE_PREPARED;
 			call_void_vb_qop(vb, buf_finish, vb);
 		}
@@ -2259,7 +2381,7 @@ static int __vb2_init_fileio(struct vb2_queue *q, int read)
 		 * Queue all buffers.
 		 */
 		for (i = 0; i < q->num_buffers; i++) {
-			ret = vb2_core_qbuf(q, i, NULL);
+			ret = vb2_core_qbuf(q, i, NULL, NULL);
 			if (ret)
 				goto err_reqbufs;
 			fileio->bufs[i].queued = 1;
@@ -2438,7 +2560,7 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_
 
 		if (copy_timestamp)
 			b->timestamp = ktime_get_ns();
-		ret = vb2_core_qbuf(q, index, NULL);
+		ret = vb2_core_qbuf(q, index, NULL, NULL);
 		dprintk(5, "vb2_dbuf result: %d\n", ret);
 		if (ret)
 			return ret;
@@ -2541,7 +2663,7 @@ static int vb2_thread(void *data)
 		if (copy_timestamp)
 			vb->timestamp = ktime_get_ns();
 		if (!threadio->stop)
-			ret = vb2_core_qbuf(q, vb->index, NULL);
+			ret = vb2_core_qbuf(q, vb->index, NULL, NULL);
 		call_void_qop(q, wait_prepare, q);
 		if (ret || threadio->stop)
 			break;
diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index bf7a3ba9fed0..b8d370b97cca 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -544,7 +544,7 @@ int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b)
 
 	ret = vb2_queue_or_prepare_buf(q, b, "prepare_buf");
 
-	return ret ? ret : vb2_core_prepare_buf(q, b->index, b);
+	return ret ? ret : vb2_core_prepare_buf(q, b->index, b, NULL);
 }
 EXPORT_SYMBOL_GPL(vb2_prepare_buf);
 
@@ -612,7 +612,7 @@ int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
 	}
 
 	ret = vb2_queue_or_prepare_buf(q, b, "qbuf");
-	return ret ? ret : vb2_core_qbuf(q, b->index, b);
+	return ret ? ret : vb2_core_qbuf(q, b->index, b, NULL);
 }
 EXPORT_SYMBOL_GPL(vb2_qbuf);
 
diff --git a/drivers/media/dvb-core/dvb_vb2.c b/drivers/media/dvb-core/dvb_vb2.c
index da6a8cec7d42..f1e7f0536028 100644
--- a/drivers/media/dvb-core/dvb_vb2.c
+++ b/drivers/media/dvb-core/dvb_vb2.c
@@ -384,7 +384,7 @@ int dvb_vb2_qbuf(struct dvb_vb2_ctx *ctx, struct dmx_buffer *b)
 {
 	int ret;
 
-	ret = vb2_core_qbuf(&ctx->vb_q, b->index, b);
+	ret = vb2_core_qbuf(&ctx->vb_q, b->index, b, NULL);
 	if (ret) {
 		dprintk(1, "[%s] index=%d errno=%d\n", ctx->name,
 			b->index, ret);
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index 3d54654c3cd4..72663c2a3ba3 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -204,6 +204,7 @@ enum vb2_io_modes {
 /**
  * enum vb2_buffer_state - current video buffer state.
  * @VB2_BUF_STATE_DEQUEUED:	buffer under userspace control.
+ * @VB2_BUF_STATE_IN_REQUEST:	buffer is queued in media request.
  * @VB2_BUF_STATE_PREPARING:	buffer is being prepared in videobuf.
  * @VB2_BUF_STATE_PREPARED:	buffer prepared in videobuf and by the driver.
  * @VB2_BUF_STATE_QUEUED:	buffer queued in videobuf, but not in driver.
@@ -218,6 +219,7 @@ enum vb2_io_modes {
  */
 enum vb2_buffer_state {
 	VB2_BUF_STATE_DEQUEUED,
+	VB2_BUF_STATE_IN_REQUEST,
 	VB2_BUF_STATE_PREPARING,
 	VB2_BUF_STATE_PREPARED,
 	VB2_BUF_STATE_QUEUED,
@@ -732,6 +734,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
  * @index:	id number of the buffer.
  * @pb:		buffer structure passed from userspace to
  *		&v4l2_ioctl_ops->vidioc_prepare_buf handler in driver.
+ * @req:	pointer to &struct media_request, may be NULL.
  *
  * Videobuf2 core helper to implement VIDIOC_PREPARE_BUF() operation. It is
  * called internally by VB2 by an API-specific handler, like
@@ -743,9 +746,13 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
  * (if provided), in which driver-specific buffer initialization can
  * be performed.
  *
+ * If @req is non-NULL, then the prepared buffer will be bound to this
+ * media request.
+ *
  * Return: returns zero on success; an error code otherwise.
  */
-int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb);
+int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb,
+			 struct media_request *req);
 
 /**
  * vb2_core_qbuf() - Queue a buffer from userspace
@@ -754,12 +761,17 @@ int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb);
  * @index:	id number of the buffer
  * @pb:		buffer structure passed from userspace to
  *		v4l2_ioctl_ops->vidioc_qbuf handler in driver
+ * @req:	pointer to &struct media_request, may be NULL.
  *
  * Videobuf2 core helper to implement VIDIOC_QBUF() operation. It is called
  * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
  *
  * This function:
  *
+ * #) If @req is non-NULL, then the buffer will be bound to this
+ *    media request and it returns. The buffer will be prepared and
+ *    queued to the driver (i.e. the next two steps) when the request
+ *    itself is queued.
  * #) if necessary, calls &vb2_ops->buf_prepare callback in the driver
  *    (if provided), in which driver-specific buffer initialization can
  *    be performed;
@@ -768,7 +780,8 @@ int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb);
  *
  * Return: returns zero on success; an error code otherwise.
  */
-int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb);
+int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
+		  struct media_request *req);
 
 /**
  * vb2_core_dqbuf() - Dequeue a buffer to the userspace
-- 
2.17.0

[RFCv12 PATCH 18/29] videobuf2-v4l2: integrate with media requests

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

This implements the V4L2 part of the request support. The main
change is that vb2_qbuf and vb2_prepare_buf now have a new
media_device pointer. This required changes to several drivers
that did not use the vb2_ioctl_qbuf/prepare_buf helper functions.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 .../media/common/videobuf2/videobuf2-v4l2.c   | 92 ++++++++++++++++---
 drivers/media/platform/omap3isp/ispvideo.c    |  2 +-
 .../media/platform/s3c-camif/camif-capture.c  |  4 +-
 drivers/media/platform/s5p-mfc/s5p_mfc_dec.c  |  4 +-
 drivers/media/platform/s5p-mfc/s5p_mfc_enc.c  |  4 +-
 .../media/platform/soc_camera/soc_camera.c    |  4 +-
 drivers/media/usb/uvc/uvc_queue.c             |  5 +-
 drivers/media/usb/uvc/uvc_v4l2.c              |  3 +-
 drivers/media/usb/uvc/uvcvideo.h              |  1 +
 drivers/media/v4l2-core/v4l2-mem2mem.c        |  7 +-
 .../staging/media/davinci_vpfe/vpfe_video.c   |  3 +-
 drivers/staging/media/omap4iss/iss_video.c    |  3 +-
 drivers/usb/gadget/function/uvc_queue.c       |  2 +-
 include/media/videobuf2-v4l2.h                | 12 ++-
 14 files changed, 114 insertions(+), 32 deletions(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index b8d370b97cca..ee1092eb3215 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -25,6 +25,7 @@
 #include <linux/kthread.h>
 
 #include <media/v4l2-dev.h>
+#include <media/v4l2-device.h>
 #include <media/v4l2-fh.h>
 #include <media/v4l2-event.h>
 #include <media/v4l2-common.h>
@@ -40,10 +41,12 @@ module_param(debug, int, 0644);
 			pr_info("vb2-v4l2: %s: " fmt, __func__, ## arg); \
 	} while (0)
 
-/* Flags that are set by the vb2 core */
+/* Flags that are set by us */
 #define V4L2_BUFFER_MASK_FLAGS	(V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_QUEUED | \
 				 V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR | \
 				 V4L2_BUF_FLAG_PREPARED | \
+				 V4L2_BUF_FLAG_IN_REQUEST | \
+				 V4L2_BUF_FLAG_REQUEST_FD | \
 				 V4L2_BUF_FLAG_TIMESTAMP_MASK)
 /* Output buffer flags that should be passed on to the driver */
 #define V4L2_BUFFER_OUT_FLAGS	(V4L2_BUF_FLAG_PFRAME | V4L2_BUF_FLAG_BFRAME | \
@@ -318,13 +321,17 @@ static int vb2_fill_vb2_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b
 	return 0;
 }
 
-static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
-				    const char *opname)
+static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *mdev,
+				    struct v4l2_buffer *b,
+				    const char *opname,
+				    struct media_request **p_req)
 {
+	struct media_request *req;
 	struct vb2_v4l2_buffer *vbuf;
 	struct vb2_buffer *vb;
 	int ret;
 
+	*p_req = NULL;
 	if (b->type != q->type) {
 		dprintk(1, "%s: invalid buffer type\n", opname);
 		return -EINVAL;
@@ -354,7 +361,46 @@ static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
 
 	/* Copy relevant information provided by the userspace */
 	memset(vbuf->planes, 0, sizeof(vbuf->planes[0]) * vb->num_planes);
-	return vb2_fill_vb2_v4l2_buffer(vb, b);
+	ret = vb2_fill_vb2_v4l2_buffer(vb, b);
+	if (ret)
+		return ret;
+
+	if (!(b->flags & V4L2_BUF_FLAG_REQUEST_FD))
+		return 0;
+
+	/*
+	 * For proper locking when queueing a request you need to be able
+	 * to lock access to the vb2 queue, so check that there is a lock
+	 * that we can use.
+	 */
+	if (WARN_ON(!q->lock))
+		return -EINVAL;
+
+	if (vb->state != VB2_BUF_STATE_DEQUEUED) {
+		dprintk(1, "%s: buffer is not in dequeued state\n", opname);
+		return -EINVAL;
+	}
+
+	if (b->request_fd < 0) {
+		dprintk(1, "%s: request_fd < 0\n", opname);
+		return -EINVAL;
+	}
+
+	req = media_request_find(mdev, b->request_fd);
+	if (IS_ERR(req)) {
+		dprintk(1, "%s: invalid request_fd\n", opname);
+		return PTR_ERR(req);
+	}
+
+	if (atomic_read(&req->state) != MEDIA_REQUEST_STATE_IDLE) {
+		dprintk(1, "%s: request is not idle\n", opname);
+		media_request_put(req);
+		return -EBUSY;
+	}
+
+	*p_req = req;
+
+	return 0;
 }
 
 /*
@@ -437,6 +483,9 @@ static void __fill_v4l2_buffer(struct vb2_buffer *vb, void *pb)
 	case VB2_BUF_STATE_ACTIVE:
 		b->flags |= V4L2_BUF_FLAG_QUEUED;
 		break;
+	case VB2_BUF_STATE_IN_REQUEST:
+		b->flags |= V4L2_BUF_FLAG_IN_REQUEST;
+		break;
 	case VB2_BUF_STATE_ERROR:
 		b->flags |= V4L2_BUF_FLAG_ERROR;
 		/* fall through */
@@ -455,6 +504,10 @@ static void __fill_v4l2_buffer(struct vb2_buffer *vb, void *pb)
 
 	if (vb2_buffer_in_use(q, vb))
 		b->flags |= V4L2_BUF_FLAG_MAPPED;
+	if (vb->req_obj.req) {
+		b->flags |= V4L2_BUF_FLAG_REQUEST_FD;
+		b->request_fd = -1;
+	}
 
 	if (!q->is_output &&
 		b->flags & V4L2_BUF_FLAG_DONE &&
@@ -533,8 +586,10 @@ int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
 }
 EXPORT_SYMBOL_GPL(vb2_reqbufs);
 
-int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b)
+int vb2_prepare_buf(struct vb2_queue *q, struct media_device *mdev,
+		    struct v4l2_buffer *b)
 {
+	struct media_request *req;
 	int ret;
 
 	if (vb2_fileio_is_active(q)) {
@@ -542,9 +597,13 @@ int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b)
 		return -EBUSY;
 	}
 
-	ret = vb2_queue_or_prepare_buf(q, b, "prepare_buf");
-
-	return ret ? ret : vb2_core_prepare_buf(q, b->index, b, NULL);
+	ret = vb2_queue_or_prepare_buf(q, mdev, b, "prepare_buf", &req);
+	if (ret)
+		return ret;
+	ret = vb2_core_prepare_buf(q, b->index, b, req);
+	if (req)
+		media_request_put(req);
+	return ret;
 }
 EXPORT_SYMBOL_GPL(vb2_prepare_buf);
 
@@ -602,8 +661,10 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
 }
 EXPORT_SYMBOL_GPL(vb2_create_bufs);
 
-int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
+int vb2_qbuf(struct vb2_queue *q, struct media_device *mdev,
+	     struct v4l2_buffer *b)
 {
+	struct media_request *req;
 	int ret;
 
 	if (vb2_fileio_is_active(q)) {
@@ -611,8 +672,13 @@ int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
 		return -EBUSY;
 	}
 
-	ret = vb2_queue_or_prepare_buf(q, b, "qbuf");
-	return ret ? ret : vb2_core_qbuf(q, b->index, b, NULL);
+	ret = vb2_queue_or_prepare_buf(q, mdev, b, "qbuf", &req);
+	if (ret)
+		return ret;
+	ret = vb2_core_qbuf(q, b->index, b, req);
+	if (req)
+		media_request_put(req);
+	return ret;
 }
 EXPORT_SYMBOL_GPL(vb2_qbuf);
 
@@ -802,7 +868,7 @@ int vb2_ioctl_prepare_buf(struct file *file, void *priv,
 
 	if (vb2_queue_is_busy(vdev, file))
 		return -EBUSY;
-	return vb2_prepare_buf(vdev->queue, p);
+	return vb2_prepare_buf(vdev->queue, vdev->v4l2_dev->mdev, p);
 }
 EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf);
 
@@ -821,7 +887,7 @@ int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p)
 
 	if (vb2_queue_is_busy(vdev, file))
 		return -EBUSY;
-	return vb2_qbuf(vdev->queue, p);
+	return vb2_qbuf(vdev->queue, vdev->v4l2_dev->mdev, p);
 }
 EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf);
 
diff --git a/drivers/media/platform/omap3isp/ispvideo.c b/drivers/media/platform/omap3isp/ispvideo.c
index bd564c2e767f..9fecbd8c6edd 100644
--- a/drivers/media/platform/omap3isp/ispvideo.c
+++ b/drivers/media/platform/omap3isp/ispvideo.c
@@ -940,7 +940,7 @@ isp_video_qbuf(struct file *file, void *fh, struct v4l2_buffer *b)
 	int ret;
 
 	mutex_lock(&video->queue_lock);
-	ret = vb2_qbuf(&vfh->queue, b);
+	ret = vb2_qbuf(&vfh->queue, video->video.v4l2_dev->mdev, b);
 	mutex_unlock(&video->queue_lock);
 
 	return ret;
diff --git a/drivers/media/platform/s3c-camif/camif-capture.c b/drivers/media/platform/s3c-camif/camif-capture.c
index 9ab8e7ee2e1e..fafb6da3e804 100644
--- a/drivers/media/platform/s3c-camif/camif-capture.c
+++ b/drivers/media/platform/s3c-camif/camif-capture.c
@@ -941,7 +941,7 @@ static int s3c_camif_qbuf(struct file *file, void *priv,
 	if (vp->owner && vp->owner != priv)
 		return -EBUSY;
 
-	return vb2_qbuf(&vp->vb_queue, buf);
+	return vb2_qbuf(&vp->vb_queue, vp->vdev.v4l2_dev->mdev, buf);
 }
 
 static int s3c_camif_dqbuf(struct file *file, void *priv,
@@ -979,7 +979,7 @@ static int s3c_camif_prepare_buf(struct file *file, void *priv,
 				 struct v4l2_buffer *b)
 {
 	struct camif_vp *vp = video_drvdata(file);
-	return vb2_prepare_buf(&vp->vb_queue, b);
+	return vb2_prepare_buf(&vp->vb_queue, vp->vdev.v4l2_dev->mdev, b);
 }
 
 static int s3c_camif_g_selection(struct file *file, void *priv,
diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc_dec.c b/drivers/media/platform/s5p-mfc/s5p_mfc_dec.c
index 5cf4d9921264..3d863e3f5798 100644
--- a/drivers/media/platform/s5p-mfc/s5p_mfc_dec.c
+++ b/drivers/media/platform/s5p-mfc/s5p_mfc_dec.c
@@ -632,9 +632,9 @@ static int vidioc_qbuf(struct file *file, void *priv, struct v4l2_buffer *buf)
 		return -EIO;
 	}
 	if (buf->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
-		return vb2_qbuf(&ctx->vq_src, buf);
+		return vb2_qbuf(&ctx->vq_src, NULL, buf);
 	else if (buf->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
-		return vb2_qbuf(&ctx->vq_dst, buf);
+		return vb2_qbuf(&ctx->vq_dst, NULL, buf);
 	return -EINVAL;
 }
 
diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc_enc.c b/drivers/media/platform/s5p-mfc/s5p_mfc_enc.c
index 5c0462ca9993..ed12d5d062e8 100644
--- a/drivers/media/platform/s5p-mfc/s5p_mfc_enc.c
+++ b/drivers/media/platform/s5p-mfc/s5p_mfc_enc.c
@@ -1621,9 +1621,9 @@ static int vidioc_qbuf(struct file *file, void *priv, struct v4l2_buffer *buf)
 			mfc_err("Call on QBUF after EOS command\n");
 			return -EIO;
 		}
-		return vb2_qbuf(&ctx->vq_src, buf);
+		return vb2_qbuf(&ctx->vq_src, NULL, buf);
 	} else if (buf->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE) {
-		return vb2_qbuf(&ctx->vq_dst, buf);
+		return vb2_qbuf(&ctx->vq_dst, NULL, buf);
 	}
 	return -EINVAL;
 }
diff --git a/drivers/media/platform/soc_camera/soc_camera.c b/drivers/media/platform/soc_camera/soc_camera.c
index e6787abc34ae..08adf9a79420 100644
--- a/drivers/media/platform/soc_camera/soc_camera.c
+++ b/drivers/media/platform/soc_camera/soc_camera.c
@@ -394,7 +394,7 @@ static int soc_camera_qbuf(struct file *file, void *priv,
 	if (icd->streamer != file)
 		return -EBUSY;
 
-	return vb2_qbuf(&icd->vb2_vidq, p);
+	return vb2_qbuf(&icd->vb2_vidq, NULL, p);
 }
 
 static int soc_camera_dqbuf(struct file *file, void *priv,
@@ -430,7 +430,7 @@ static int soc_camera_prepare_buf(struct file *file, void *priv,
 {
 	struct soc_camera_device *icd = file->private_data;
 
-	return vb2_prepare_buf(&icd->vb2_vidq, b);
+	return vb2_prepare_buf(&icd->vb2_vidq, NULL, b);
 }
 
 static int soc_camera_expbuf(struct file *file, void *priv,
diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c
index fecccb5e7628..8964e16f2b22 100644
--- a/drivers/media/usb/uvc/uvc_queue.c
+++ b/drivers/media/usb/uvc/uvc_queue.c
@@ -300,12 +300,13 @@ int uvc_create_buffers(struct uvc_video_queue *queue,
 	return ret;
 }
 
-int uvc_queue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
+int uvc_queue_buffer(struct uvc_video_queue *queue,
+		     struct media_device *mdev, struct v4l2_buffer *buf)
 {
 	int ret;
 
 	mutex_lock(&queue->mutex);
-	ret = vb2_qbuf(&queue->queue, buf);
+	ret = vb2_qbuf(&queue->queue, mdev, buf);
 	mutex_unlock(&queue->mutex);
 
 	return ret;
diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index bd32914259ae..3da5fdc002ac 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -751,7 +751,8 @@ static int uvc_ioctl_qbuf(struct file *file, void *fh, struct v4l2_buffer *buf)
 	if (!uvc_has_privileges(handle))
 		return -EBUSY;
 
-	return uvc_queue_buffer(&stream->queue, buf);
+	return uvc_queue_buffer(&stream->queue,
+				stream->vdev.v4l2_dev->mdev, buf);
 }
 
 static int uvc_ioctl_expbuf(struct file *file, void *fh,
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index be5cf179228b..bc9ed18f043c 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -680,6 +680,7 @@ int uvc_query_buffer(struct uvc_video_queue *queue,
 int uvc_create_buffers(struct uvc_video_queue *queue,
 		       struct v4l2_create_buffers *v4l2_cb);
 int uvc_queue_buffer(struct uvc_video_queue *queue,
+		     struct media_device *mdev,
 		     struct v4l2_buffer *v4l2_buf);
 int uvc_export_buffer(struct uvc_video_queue *queue,
 		      struct v4l2_exportbuffer *exp);
diff --git a/drivers/media/v4l2-core/v4l2-mem2mem.c b/drivers/media/v4l2-core/v4l2-mem2mem.c
index c4f963d96a79..438f1b869319 100644
--- a/drivers/media/v4l2-core/v4l2-mem2mem.c
+++ b/drivers/media/v4l2-core/v4l2-mem2mem.c
@@ -20,6 +20,7 @@
 #include <media/videobuf2-v4l2.h>
 #include <media/v4l2-mem2mem.h>
 #include <media/v4l2-dev.h>
+#include <media/v4l2-device.h>
 #include <media/v4l2-fh.h>
 #include <media/v4l2-event.h>
 
@@ -388,11 +389,12 @@ EXPORT_SYMBOL_GPL(v4l2_m2m_querybuf);
 int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 		  struct v4l2_buffer *buf)
 {
+	struct video_device *vdev = video_devdata(file);
 	struct vb2_queue *vq;
 	int ret;
 
 	vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
-	ret = vb2_qbuf(vq, buf);
+	ret = vb2_qbuf(vq, vdev->v4l2_dev->mdev, buf);
 	if (!ret)
 		v4l2_m2m_try_schedule(m2m_ctx);
 
@@ -413,11 +415,12 @@ EXPORT_SYMBOL_GPL(v4l2_m2m_dqbuf);
 int v4l2_m2m_prepare_buf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 			 struct v4l2_buffer *buf)
 {
+	struct video_device *vdev = video_devdata(file);
 	struct vb2_queue *vq;
 	int ret;
 
 	vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
-	ret = vb2_prepare_buf(vq, buf);
+	ret = vb2_prepare_buf(vq, vdev->v4l2_dev->mdev, buf);
 	if (!ret)
 		v4l2_m2m_try_schedule(m2m_ctx);
 
diff --git a/drivers/staging/media/davinci_vpfe/vpfe_video.c b/drivers/staging/media/davinci_vpfe/vpfe_video.c
index 390fc98d07dd..0d243a71d82c 100644
--- a/drivers/staging/media/davinci_vpfe/vpfe_video.c
+++ b/drivers/staging/media/davinci_vpfe/vpfe_video.c
@@ -1426,7 +1426,8 @@ static int vpfe_qbuf(struct file *file, void *priv,
 		return -EACCES;
 	}
 
-	return vb2_qbuf(&video->buffer_queue, p);
+	return vb2_qbuf(&video->buffer_queue,
+			video->video_dev.v4l2_dev->mdev, p);
 }
 
 /*
diff --git a/drivers/staging/media/omap4iss/iss_video.c b/drivers/staging/media/omap4iss/iss_video.c
index a3a83424a926..a35d1004b522 100644
--- a/drivers/staging/media/omap4iss/iss_video.c
+++ b/drivers/staging/media/omap4iss/iss_video.c
@@ -805,9 +805,10 @@ iss_video_querybuf(struct file *file, void *fh, struct v4l2_buffer *b)
 static int
 iss_video_qbuf(struct file *file, void *fh, struct v4l2_buffer *b)
 {
+	struct iss_video *video = video_drvdata(file);
 	struct iss_video_fh *vfh = to_iss_video_fh(fh);
 
-	return vb2_qbuf(&vfh->queue, b);
+	return vb2_qbuf(&vfh->queue, video->video.v4l2_dev->mdev, b);
 }
 
 static int
diff --git a/drivers/usb/gadget/function/uvc_queue.c b/drivers/usb/gadget/function/uvc_queue.c
index 9e33d5206d54..f2497cb96abb 100644
--- a/drivers/usb/gadget/function/uvc_queue.c
+++ b/drivers/usb/gadget/function/uvc_queue.c
@@ -166,7 +166,7 @@ int uvcg_queue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
 	unsigned long flags;
 	int ret;
 
-	ret = vb2_qbuf(&queue->queue, buf);
+	ret = vb2_qbuf(&queue->queue, NULL, buf);
 	if (ret < 0)
 		return ret;
 
diff --git a/include/media/videobuf2-v4l2.h b/include/media/videobuf2-v4l2.h
index 097bf3e6951d..cf312ab4e7e8 100644
--- a/include/media/videobuf2-v4l2.h
+++ b/include/media/videobuf2-v4l2.h
@@ -79,6 +79,7 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create);
  * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
  *
  * @q:		pointer to &struct vb2_queue with videobuf2 queue.
+ * @mdev:	pointer to &struct media_device, may be NULL.
  * @b:		buffer structure passed from userspace to
  *		&v4l2_ioctl_ops->vidioc_prepare_buf handler in driver
  *
@@ -90,15 +91,19 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create);
  * #) verifies the passed buffer,
  * #) calls &vb2_ops->buf_prepare callback in the driver (if provided),
  *    in which driver-specific buffer initialization can be performed.
+ * #) if @b->request_fd is non-zero and @mdev->ops->req_queue is set,
+ *    then bind the prepared buffer to the request.
  *
  * The return values from this function are intended to be directly returned
  * from &v4l2_ioctl_ops->vidioc_prepare_buf handler in driver.
  */
-int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b);
+int vb2_prepare_buf(struct vb2_queue *q, struct media_device *mdev,
+		    struct v4l2_buffer *b);
 
 /**
  * vb2_qbuf() - Queue a buffer from userspace
  * @q:		pointer to &struct vb2_queue with videobuf2 queue.
+ * @mdev:	pointer to &struct media_device, may be NULL.
  * @b:		buffer structure passed from userspace to
  *		&v4l2_ioctl_ops->vidioc_qbuf handler in driver
  *
@@ -107,6 +112,8 @@ int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b);
  * This function:
  *
  * #) verifies the passed buffer;
+ * #) if @b->request_fd is non-zero and @mdev->ops->req_queue is set,
+ *    then bind the buffer to the request.
  * #) if necessary, calls &vb2_ops->buf_prepare callback in the driver
  *    (if provided), in which driver-specific buffer initialization can
  *    be performed;
@@ -116,7 +123,8 @@ int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b);
  * The return values from this function are intended to be directly returned
  * from &v4l2_ioctl_ops->vidioc_qbuf handler in driver.
  */
-int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b);
+int vb2_qbuf(struct vb2_queue *q, struct media_device *mdev,
+	     struct v4l2_buffer *b);
 
 /**
  * vb2_expbuf() - Export a buffer as a file descriptor
-- 
2.17.0

[RFCv12 PATCH 19/29] videobuf2-core: add vb2_core_request_has_buffers

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

Add a new helper function that returns true if a media_request
contains buffers.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/common/videobuf2/videobuf2-core.c | 17 +++++++++++++++++
 include/media/videobuf2-core.h                  | 15 +++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index 31b86bfa52bd..42854242405f 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -1344,6 +1344,23 @@ static const struct media_request_object_ops vb2_core_req_ops = {
 	.release = vb2_req_release,
 };
 
+bool vb2_request_object_is_buffer(struct media_request_object *obj)
+{
+	return obj->ops == &vb2_core_req_ops;
+}
+EXPORT_SYMBOL_GPL(vb2_request_object_is_buffer);
+
+bool vb2_request_has_buffers(struct media_request *req)
+{
+	struct media_request_object *obj;
+
+	list_for_each_entry(obj, &req->objects, list)
+		if (vb2_request_object_is_buffer(obj))
+			return true;
+	return false;
+}
+EXPORT_SYMBOL_GPL(vb2_request_has_buffers);
+
 int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb,
 			 struct media_request *req)
 {
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index 72663c2a3ba3..9e332969826b 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -1158,4 +1158,19 @@ bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb);
  */
 int vb2_verify_memory_type(struct vb2_queue *q,
 		enum vb2_memory memory, unsigned int type);
+
+/**
+ * vb2_request_object_is_buffer() - return true if the object is a buffer
+ *
+ * @obj:	the request object.
+ */
+bool vb2_request_object_is_buffer(struct media_request_object *obj);
+
+/**
+ * vb2_request_has_buffers() - return true if the request contains buffers
+ *
+ * @req:	the request.
+ */
+bool vb2_request_has_buffers(struct media_request *req);
+
 #endif /* _MEDIA_VIDEOBUF2_CORE_H */
-- 
2.17.0

[RFCv12 PATCH 20/29] videobuf2-v4l2: add vb2_request_queue/validate helpers

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

The generic vb2_request_validate helper function checks if
there are buffers in the request and if so, prepares and all
objects in the request.

The generic vb2_request_queue helper function queues all buffer
objects in the validated request.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 .../media/common/videobuf2/videobuf2-v4l2.c   | 38 +++++++++++++++++++
 include/media/videobuf2-v4l2.h                |  4 ++
 2 files changed, 42 insertions(+)

diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index ee1092eb3215..7fced0a503f4 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -1069,6 +1069,44 @@ void vb2_ops_wait_finish(struct vb2_queue *vq)
 }
 EXPORT_SYMBOL_GPL(vb2_ops_wait_finish);
 
+int vb2_request_validate(struct media_request *req)
+{
+	struct media_request_object *obj;
+	int ret = 0;
+
+	if (!vb2_request_has_buffers(req))
+		return -ENOENT;
+
+	list_for_each_entry(obj, &req->objects, list) {
+		if (!obj->ops->prepare)
+			continue;
+
+		ret = obj->ops->prepare(obj);
+		if (ret)
+			break;
+	}
+
+	if (ret) {
+		list_for_each_entry_continue_reverse(obj, &req->objects, list)
+			if (obj->ops->unprepare)
+				obj->ops->unprepare(obj);
+		return ret;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(vb2_request_validate);
+
+void vb2_request_queue(struct media_request *req)
+{
+	struct media_request_object *obj;
+
+	list_for_each_entry(obj, &req->objects, list) {
+		if (obj->ops->queue)
+			obj->ops->queue(obj);
+	}
+}
+EXPORT_SYMBOL_GPL(vb2_request_queue);
+
 MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
 MODULE_LICENSE("GPL");
diff --git a/include/media/videobuf2-v4l2.h b/include/media/videobuf2-v4l2.h
index cf312ab4e7e8..33210221a621 100644
--- a/include/media/videobuf2-v4l2.h
+++ b/include/media/videobuf2-v4l2.h
@@ -301,4 +301,8 @@ void vb2_ops_wait_prepare(struct vb2_queue *vq);
  */
 void vb2_ops_wait_finish(struct vb2_queue *vq);
 
+struct media_request;
+int vb2_request_validate(struct media_request *req);
+void vb2_request_queue(struct media_request *req);
+
 #endif /* _MEDIA_VIDEOBUF2_V4L2_H */
-- 
2.17.0

[RFCv12 PATCH 21/29] videobuf2-v4l2: export request_fd

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

Requested by Sakari

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/common/videobuf2/videobuf2-v4l2.c | 6 ++++--
 include/media/videobuf2-v4l2.h                  | 2 ++
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index 7fced0a503f4..b6142041418e 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -184,6 +184,7 @@ static int vb2_fill_vb2_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b
 		return -EINVAL;
 	}
 	vbuf->sequence = 0;
+	vbuf->request_fd = -1;
 
 	if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
 		switch (b->memory) {
@@ -399,6 +400,7 @@ static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *md
 	}
 
 	*p_req = req;
+	vbuf->request_fd = b->request_fd;
 
 	return 0;
 }
@@ -504,9 +506,9 @@ static void __fill_v4l2_buffer(struct vb2_buffer *vb, void *pb)
 
 	if (vb2_buffer_in_use(q, vb))
 		b->flags |= V4L2_BUF_FLAG_MAPPED;
-	if (vb->req_obj.req) {
+	if (vbuf->request_fd >= 0) {
 		b->flags |= V4L2_BUF_FLAG_REQUEST_FD;
-		b->request_fd = -1;
+		b->request_fd = vbuf->request_fd;
 	}
 
 	if (!q->is_output &&
diff --git a/include/media/videobuf2-v4l2.h b/include/media/videobuf2-v4l2.h
index 33210221a621..727855463838 100644
--- a/include/media/videobuf2-v4l2.h
+++ b/include/media/videobuf2-v4l2.h
@@ -32,6 +32,7 @@
  *		&enum v4l2_field.
  * @timecode:	frame timecode.
  * @sequence:	sequence count of this frame.
+ * @request_fd:	the request_fd associated with this buffer
  * @planes:	plane information (userptr/fd, length, bytesused, data_offset).
  *
  * Should contain enough information to be able to cover all the fields
@@ -44,6 +45,7 @@ struct vb2_v4l2_buffer {
 	__u32			field;
 	struct v4l2_timecode	timecode;
 	__u32			sequence;
+	__s32			request_fd;
 	struct vb2_plane	planes[VB2_MAX_PLANES];
 };
 
-- 
2.17.0

[RFCv12 PATCH 22/29] v4l2-mem2mem: add vb2_m2m_request_queue

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

For mem2mem devices we have to make sure that v4l2_m2m_try_schedule()
is called whenever a request is queued.

We do that by creating a vb2_m2m_request_queue() helper that should
be used instead of the 'normal' vb2_request_queue() helper. The m2m
helper function will call v4l2_m2m_try_schedule() as needed.

In addition we also avoid calling v4l2_m2m_try_schedule() when preparing
or queueing a buffer for a request since that is no longer needed.
Instead this helper function will do that when the request is actually
queued.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/v4l2-mem2mem.c | 33 ++++++++++++++++++++++++--
 include/media/v4l2-mem2mem.h           |  4 ++++
 2 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-mem2mem.c b/drivers/media/v4l2-core/v4l2-mem2mem.c
index 438f1b869319..80233bf6523a 100644
--- a/drivers/media/v4l2-core/v4l2-mem2mem.c
+++ b/drivers/media/v4l2-core/v4l2-mem2mem.c
@@ -395,7 +395,7 @@ int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 
 	vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
 	ret = vb2_qbuf(vq, vdev->v4l2_dev->mdev, buf);
-	if (!ret)
+	if (!ret && !(buf->flags & V4L2_BUF_FLAG_IN_REQUEST))
 		v4l2_m2m_try_schedule(m2m_ctx);
 
 	return ret;
@@ -421,7 +421,7 @@ int v4l2_m2m_prepare_buf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 
 	vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
 	ret = vb2_prepare_buf(vq, vdev->v4l2_dev->mdev, buf);
-	if (!ret)
+	if (!ret && !(buf->flags & V4L2_BUF_FLAG_IN_REQUEST))
 		v4l2_m2m_try_schedule(m2m_ctx);
 
 	return ret;
@@ -701,6 +701,35 @@ void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx,
 }
 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_queue);
 
+void vb2_m2m_request_queue(struct media_request *req)
+{
+	struct media_request_object *obj;
+
+	list_for_each_entry(obj, &req->objects, list) {
+		struct v4l2_m2m_ctx *m2m_ctx;
+		struct vb2_buffer *vb;
+
+		if (!obj->ops->queue)
+			continue;
+
+		obj->ops->queue(obj);
+		if (!vb2_request_object_is_buffer(obj))
+			continue;
+
+		vb = container_of(obj, struct vb2_buffer, req_obj);
+		if (V4L2_TYPE_IS_OUTPUT(vb->vb2_queue->type))
+			m2m_ctx = container_of(vb->vb2_queue,
+					       struct v4l2_m2m_ctx,
+					       out_q_ctx.q);
+		else
+			m2m_ctx = container_of(vb->vb2_queue,
+					       struct v4l2_m2m_ctx,
+					       cap_q_ctx.q);
+		v4l2_m2m_try_schedule(m2m_ctx);
+	}
+}
+EXPORT_SYMBOL_GPL(vb2_m2m_request_queue);
+
 /* Videobuf2 ioctl helpers */
 
 int v4l2_m2m_ioctl_reqbufs(struct file *file, void *priv,
diff --git a/include/media/v4l2-mem2mem.h b/include/media/v4l2-mem2mem.h
index 3d07ba3a8262..f01b3fc13b0e 100644
--- a/include/media/v4l2-mem2mem.h
+++ b/include/media/v4l2-mem2mem.h
@@ -580,6 +580,10 @@ v4l2_m2m_dst_buf_remove_by_idx(struct v4l2_m2m_ctx *m2m_ctx, unsigned int idx)
 	return v4l2_m2m_buf_remove_by_idx(&m2m_ctx->cap_q_ctx, idx);
 }
 
+/* v4l2 request helper */
+
+void vb2_m2m_request_queue(struct media_request *req);
+
 /* v4l2 ioctl helpers */
 
 int v4l2_m2m_ioctl_reqbufs(struct file *file, void *priv,
-- 
2.17.0

[RFCv12 PATCH 23/29] Documentation: v4l: document request API

[Hans Verkuil]

From: Alexandre Courbot <acourbot@chromium.org>

Document the request API for V4L2 devices, and amend the documentation
of system calls influenced by it.

Signed-off-by: Alexandre Courbot <acourbot@chromium.org>
---
 Documentation/media/uapi/v4l/buffer.rst       |  19 +-
 Documentation/media/uapi/v4l/common.rst       |   1 +
 Documentation/media/uapi/v4l/request-api.rst  | 218 ++++++++++++++++++
 .../media/uapi/v4l/vidioc-g-ext-ctrls.rst     |  25 +-
 Documentation/media/uapi/v4l/vidioc-qbuf.rst  |   8 +
 .../media/videodev2.h.rst.exceptions          |   1 +
 6 files changed, 266 insertions(+), 6 deletions(-)
 create mode 100644 Documentation/media/uapi/v4l/request-api.rst

diff --git a/Documentation/media/uapi/v4l/buffer.rst b/Documentation/media/uapi/v4l/buffer.rst
index e2c85ddc990b..5b312faf93b8 100644
--- a/Documentation/media/uapi/v4l/buffer.rst
+++ b/Documentation/media/uapi/v4l/buffer.rst
@@ -306,10 +306,13 @@ struct v4l2_buffer
       - A place holder for future extensions. Drivers and applications
 	must set this to 0.
     * - __u32
-      - ``reserved``
+      - ``request_fd``
       -
-      - A place holder for future extensions. Drivers and applications
-	must set this to 0.
+      - The file descriptor of the request to queue the buffer to. If specified
+        and flag ``V4L2_BUF_FLAG_REQUEST_FD`` is set, then the buffer will be
+	queued to that request. This is set by the user when calling
+	:ref:`VIDIOC_QBUF` and :ref:`VIDIOC_PREPARE_BUF` and ignored by other
+	ioctls.
 
 
 
@@ -514,6 +517,11 @@ Buffer Flags
 	streaming may continue as normal and the buffer may be reused
 	normally. Drivers set this flag when the ``VIDIOC_DQBUF`` ioctl is
 	called.
+    * .. _`V4L2-BUF-FLAG-IN-REQUEST`:
+
+      - ``V4L2_BUF_FLAG_IN_REQUEST``
+      - 0x00000080
+      - This buffer is part of a request that hasn't been queued yet.
     * .. _`V4L2-BUF-FLAG-KEYFRAME`:
 
       - ``V4L2_BUF_FLAG_KEYFRAME``
@@ -589,6 +597,11 @@ Buffer Flags
 	the format. Any Any subsequent call to the
 	:ref:`VIDIOC_DQBUF <VIDIOC_QBUF>` ioctl will not block anymore,
 	but return an ``EPIPE`` error code.
+    * .. _`V4L2-BUF-FLAG-REQUEST-FD`:
+
+      - ``V4L2_BUF_FLAG_REQUEST_FD``
+      - 0x00800000
+      - The ``request_fd`` field contains a valid file descriptor.
     * .. _`V4L2-BUF-FLAG-TIMESTAMP-MASK`:
 
       - ``V4L2_BUF_FLAG_TIMESTAMP_MASK``
diff --git a/Documentation/media/uapi/v4l/common.rst b/Documentation/media/uapi/v4l/common.rst
index 13f2ed3fc5a6..a4aa0059d45a 100644
--- a/Documentation/media/uapi/v4l/common.rst
+++ b/Documentation/media/uapi/v4l/common.rst
@@ -44,3 +44,4 @@ applicable to all devices.
     crop
     selection-api
     streaming-par
+    request-api
diff --git a/Documentation/media/uapi/v4l/request-api.rst b/Documentation/media/uapi/v4l/request-api.rst
new file mode 100644
index 000000000000..e9576ccb1111
--- /dev/null
+++ b/Documentation/media/uapi/v4l/request-api.rst
@@ -0,0 +1,218 @@
+.. -*- coding: utf-8; mode: rst -*-
+
+.. _media-request-api:
+
+Request API
+===========
+
+The Request API has been designed to allow V4L2 to deal with requirements of
+modern devices (stateless codecs, MIPI cameras, ...) and APIs (Android Codec
+v2). One such requirement is the ability for devices belonging to the same
+pipeline to reconfigure and collaborate closely on a per-frame basis. Another is
+efficient support of stateless codecs, which need per-frame controls to be set
+asynchronously in order to be used efficiently.
+
+Supporting these features without the Request API is possible but terribly
+inefficient: user-space would have to flush all activity on the media pipeline,
+reconfigure it for the next frame, queue the buffers to be processed with that
+configuration, and wait until they are all available for dequeuing before
+considering the next frame. This defeats the purpose of having buffer queues
+since in practice only one buffer would be queued at a time.
+
+The Request API allows a specific configuration of the pipeline (media
+controller topology + controls for each device) to be associated with specific
+buffers. The parameters are applied by each participating device as buffers
+associated to a request flow in. This allows user-space to schedule several
+tasks ("requests") with different parameters in advance, knowing that the
+parameters will be applied when needed to get the expected result. Controls
+values at the time of request completion are also available for reading.
+
+Usage
+=====
+
+The Request API is used on top of standard media controller and V4L2 calls,
+which are augmented with an extra ``request_fd`` parameter. Request themselves
+are allocated from either a supporting V4L2 device node, or a supporting media
+controller node. The origin of requests determine their scope: requests
+allocated from a V4L2 device node can only act on that device, whereas requests
+allocated from a media controller node can control the whole pipeline of the
+controller.
+
+Request Allocation
+------------------
+
+User-space allocates requests using the ``MEDIA_IOC_REQUEST_ALLOC`` ioctl
+for the media device node. This returns a file descriptor representing the
+request. Typically, several such requests will be allocated.
+
+Request Preparation
+-------------------
+
+Standard V4L2 ioctls can then receive a request file descriptor to express the
+fact that the ioctl is part of said request, and is not to be applied
+immediately. V4L2 ioctls supporting this are :c:func:`VIDIOC_S_EXT_CTRLS` and
+:c:func:`VIDIOC_QBUF`. Controls set with a request parameter are stored instead
+of being immediately applied, and queued buffers not enter the regular buffer
+queue until the request is submitted. Only one buffer can be queued to a given
+queue for a given request.
+
+Request Submission
+------------------
+
+Once the parameters and buffers of the request are specified, it can be
+submitted by calling the ``MEDIA_REQUEST_IOC_QUEUE`` ioctl on the request FD.
+This will make the buffers associated to the request available to their driver,
+which can then apply the saved controls as buffers are processed. A submitted
+request cannot be modified anymore.
+
+If several devices are part of the request, individual drivers may synchronize
+so the requested pipeline's topology is applied before the buffers are
+processed. This is at the discretion of media controller drivers and is not a
+requirement.
+
+Buffers queued without an associated request after a request-bound buffer will
+be processed using the state of the hardware at the time of the request
+completion. All the same, controls set without a request are applied
+immediately, regardless of whether a request is in use or not.
+
+User-space can ``poll()`` a request FD in order to wait until the request
+completes. A request is considered complete once all its associated buffers are
+available for dequeuing. Note that user-space does not need to wait for the
+request to complete to dequeue its buffers: buffers that are available halfway
+through a request can be dequeued independently of the request's state.
+
+A completed request contains the state of the request at the time of the
+request completion. User-space can query that state by calling
+:c:func:`VIDIOC_G_EXT_CTRLS` with the request FD.
+
+Recycling and Destruction
+-------------------------
+
+Finally, completed request can either be discarded or be reused. Calling
+``close()`` on a request FD will make that FD unusable, freeing the request if
+it is not referenced elsewhere. The ``MEDIA_REQUEST_IOC_QUEUE`` ioctl will
+clear a request's state and make it available again. No state is retained by
+this operation: the request is as if it had just been allocated.
+
+Example for a M2M Device
+------------------------
+
+M2M devices are single-node V4L2 devices providing one OUTPUT queue (for
+user-space
+to provide input buffers) and one CAPTURE queue (to retrieve processed data).
+They are perfectly symetric, i.e. one buffer of input will produce one buffer of
+output. These devices are commonly used for frame processors or stateless
+codecs.
+
+In this use-case, the request API can be used to associate specific controls to
+be applied by the driver before processing an OUTPUT buffer, allowing user-space
+to queue many such buffers in advance. It can also take advantage of requests'
+ability to capture the state of controls when the request completes to read back
+information that may be subject to change.
+
+Put into code, after obtaining a request, user-space can assign controls and one
+OUTPUT buffer to it:
+
+.. code-block:: c
+
+	struct v4l2_buffer buf;
+	struct v4l2_ext_controls ctrls;
+	struct media_request_alloc alloc = { 0 };
+	int req_fd;
+	...
+	ioctl(media_fd, MEDIA_IOC_REQUEST_ALLOC, &alloc);
+	req_fd = alloc.fd;
+	...
+	ctrls.which = V4L2_CTRL_WHICH_REQUEST_VAL;
+	ctrls.request_fd = req_fd;
+	ioctl(codec_fd, VIDIOC_S_EXT_CTRLS, &ctrls);
+	...
+	buf.type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
+	buf.flags |= V4L2_BUF_FLAG_REQUEST_FD;
+	buf.request_fd = req_fd;
+	ioctl(codec_fd, VIDIOC_QBUF, &buf);
+
+Note that request_fd does not need to be specified for CAPTURE buffers: since
+there is symetry between the OUTPUT and CAPTURE queues, and requests are
+processed in order of submission, we can know which CAPTURE buffer corresponds
+to which request.
+
+Once the request is fully prepared, it can be submitted to the driver:
+
+.. code-block:: c
+
+	ioctl(request_fd, MEDIA_REQUEST_IOC_QUEUE, NULL);
+
+User-space can then either wait for the request to complete by calling poll() on
+its file descriptor, or start dequeuing CAPTURE buffers. Most likely, it will
+want to get CAPTURE buffers as soon as possible and this can be done using a
+regular DQBUF:
+
+.. code-block:: c
+
+	struct v4l2_buffer buf;
+
+	memset(&buf, 0, sizeof(buf));
+	buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	ioctl(codec_fd, VIDIOC_DQBUF, &buf);
+
+We can then, after ensuring that the request is completed via polling the
+request FD, query control values at the time of its completion via an
+annotated call to G_EXT_CTRLS. This is particularly useful for volatile controls
+for which we want to query values as soon as the capture buffer is produced.
+
+.. code-block:: c
+
+	struct pollfd pfd = { .events = POLLIN, .fd = request_fd };
+	poll(&pfd, 1, -1);
+	...
+	ctrls.request_fd = req_fd;
+	ioctl(codec_fd, VIDIOC_G_EXT_CTRLS, &ctrls);
+
+Once we don't need the request anymore, we can either recycle it for reuse with
+MEDIA_REQUEST_IOC_REINIT...
+
+.. code-block:: c
+
+	ioctl(request, MEDIA_REQUEST_IOC_REINIT, NULL);
+
+... or close its file descriptor to completely dispose of it.
+
+.. code-block:: c
+
+	close(request_fd);
+
+Example for a Simple Capture Device
+-----------------------------------
+
+With a simple capture device, requests can be used to specify controls to apply
+to a given CAPTURE buffer. The driver will apply these controls before producing
+the marked CAPTURE buffer.
+
+.. code-block:: c
+
+	struct v4l2_buffer buf;
+	struct v4l2_ext_controls ctrls;
+	struct media_request_alloc alloc = { 0 };
+	int req_fd;
+	...
+	ioctl(media_fd, MEDIA_IOC_REQUEST_ALLOC, &alloc);
+	req_fd = alloc.fd;
+	...
+	ctrls.which = V4L2_CTRL_WHICH_REQUEST_VAL;
+	ctrls.request_fd = req_fd;
+	ioctl(camera_fd, VIDIOC_S_EXT_CTRLS, &ctrls);
+	...
+	buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	buf.flags |= V4L2_BUF_FLAG_REQUEST_FD;
+	buf.request_fd = req_fd;
+	ioctl(camera_fd, VIDIOC_QBUF, &buf);
+
+Once the request is fully prepared, it can be submitted to the driver:
+
+.. code-block:: c
+
+	ioctl(req_fd, MEDIA_REQUEST_IOC_QUEUE, &cmd);
+
+User-space can then dequeue buffers, wait for the request completion, query
+controls and recycle the request as in the M2M example above.
diff --git a/Documentation/media/uapi/v4l/vidioc-g-ext-ctrls.rst b/Documentation/media/uapi/v4l/vidioc-g-ext-ctrls.rst
index 2011c2b2ee67..e463384f6f6c 100644
--- a/Documentation/media/uapi/v4l/vidioc-g-ext-ctrls.rst
+++ b/Documentation/media/uapi/v4l/vidioc-g-ext-ctrls.rst
@@ -95,6 +95,19 @@ appropriate. In the first case the new value is set in struct
 is inappropriate (e.g. the given menu index is not supported by the menu
 control), then this will also result in an ``EINVAL`` error code error.
 
+If ``request_fd`` is set to a not-submitted request file descriptor and
+``which`` is set to V4L2_CTRL_WHICH_REQUEST_VAL, then the
+controls are not applied immediately when calling
+:ref:`VIDIOC_S_EXT_CTRLS <VIDIOC_G_EXT_CTRLS>`, but instead are applied right
+before the driver starts processing a buffer associated to the same request.
+
+If ``request_fd`` is specified and ``which`` is set to V4L2_CTRL_WHICH_REQUEST_VAL
+during a call to :ref:`VIDIOC_G_EXT_CTRLS <VIDIOC_G_EXT_CTRLS>`, then the
+returned values will be the values currently set for the request (or the
+hardware value if none is set) if the request has not yet completed, or the
+values of the controls at the time of request completion if it has already
+completed.
+
 The driver will only set/get these controls if all control values are
 correct. This prevents the situation where only some of the controls
 were set/get. Only low-level errors (e. g. a failed i2c command) can
@@ -209,8 +222,10 @@ still cause this situation.
       - ``which``
       - Which value of the control to get/set/try.
 	``V4L2_CTRL_WHICH_CUR_VAL`` will return the current value of the
-	control and ``V4L2_CTRL_WHICH_DEF_VAL`` will return the default
-	value of the control.
+	control, ``V4L2_CTRL_WHICH_DEF_VAL`` will return the default
+	value of the control and ``V4L2_CTRL_WHICH_REQUEST_VAL`` indicates that
+	these controls have to be retrieved from a request or tried/set for
+	a request.
 
 	.. note::
 
@@ -272,8 +287,12 @@ still cause this situation.
 	then you can call :ref:`VIDIOC_TRY_EXT_CTRLS <VIDIOC_G_EXT_CTRLS>` to try to discover the
 	actual control that failed the validation step. Unfortunately,
 	there is no ``TRY`` equivalent for :ref:`VIDIOC_G_EXT_CTRLS <VIDIOC_G_EXT_CTRLS>`.
+    * - __s32
+      - ``request_fd``
+	File descriptor of the request to be used by this operation. Only
+	valid if ``which`` is set to ``V4L2_CTRL_WHICH_REQUEST_VAL``.
     * - __u32
-      - ``reserved``\ [2]
+      - ``reserved``\ [1]
       - Reserved for future extensions.
 
 	Drivers and applications must set the array to zero.
diff --git a/Documentation/media/uapi/v4l/vidioc-qbuf.rst b/Documentation/media/uapi/v4l/vidioc-qbuf.rst
index 9e448a4aa3aa..6246f1888583 100644
--- a/Documentation/media/uapi/v4l/vidioc-qbuf.rst
+++ b/Documentation/media/uapi/v4l/vidioc-qbuf.rst
@@ -98,6 +98,14 @@ dequeued, until the :ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>` or
 :ref:`VIDIOC_REQBUFS` ioctl is called, or until the
 device is closed.
 
+The ``request_fd`` field can be used when queuing to specify the file
+descriptor of a request, if requests are in use. Setting it means that the
+buffer will not be passed to the driver until the request itself is submitted.
+Also, the driver will apply any setting associated with the request before
+processing the buffer. Only one buffer per queue can be assigned that way to
+a request. This field will be ignored unless the ``V4L2_BUF_FLAG_REQUEST_FD``
+flag is set.
+
 Applications call the ``VIDIOC_DQBUF`` ioctl to dequeue a filled
 (capturing) or displayed (output) buffer from the driver's outgoing
 queue. They just set the ``type``, ``memory`` and ``reserved`` fields of
diff --git a/Documentation/media/videodev2.h.rst.exceptions b/Documentation/media/videodev2.h.rst.exceptions
index a5cb0a8686ac..5a5a1c772053 100644
--- a/Documentation/media/videodev2.h.rst.exceptions
+++ b/Documentation/media/videodev2.h.rst.exceptions
@@ -514,6 +514,7 @@ ignore define V4L2_CTRL_DRIVER_PRIV
 ignore define V4L2_CTRL_MAX_DIMS
 ignore define V4L2_CTRL_WHICH_CUR_VAL
 ignore define V4L2_CTRL_WHICH_DEF_VAL
+ignore define V4L2_CTRL_WHICH_REQUEST_VAL
 ignore define V4L2_OUT_CAP_CUSTOM_TIMINGS
 ignore define V4L2_CID_MAX_CTRLS
 
-- 
2.17.0

[RFCv12 PATCH 24/29] media: vim2m: add media device

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

Request API requires a media node. Add one to the vim2m driver so we can
use requests with it.

This probably needs a bit more work to correctly represent m2m
hardware in the media topology.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/platform/vim2m.c | 42 ++++++++++++++++++++++++++++++----
 1 file changed, 37 insertions(+), 5 deletions(-)

diff --git a/drivers/media/platform/vim2m.c b/drivers/media/platform/vim2m.c
index 065483e62db4..9be4da3b8577 100644
--- a/drivers/media/platform/vim2m.c
+++ b/drivers/media/platform/vim2m.c
@@ -140,6 +140,10 @@ static struct vim2m_fmt *find_format(struct v4l2_format *f)
 struct vim2m_dev {
 	struct v4l2_device	v4l2_dev;
 	struct video_device	vfd;
+#ifdef CONFIG_MEDIA_CONTROLLER
+	struct media_device	mdev;
+	struct media_pad	pad[2];
+#endif
 
 	atomic_t		num_inst;
 	struct mutex		dev_mutex;
@@ -1000,11 +1004,6 @@ static int vim2m_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	spin_lock_init(&dev->irqlock);
-
-	ret = v4l2_device_register(&pdev->dev, &dev->v4l2_dev);
-	if (ret)
-		return ret;
-
 	atomic_set(&dev->num_inst, 0);
 	mutex_init(&dev->dev_mutex);
 
@@ -1013,6 +1012,22 @@ static int vim2m_probe(struct platform_device *pdev)
 	vfd->lock = &dev->dev_mutex;
 	vfd->v4l2_dev = &dev->v4l2_dev;
 
+#ifdef CONFIG_MEDIA_CONTROLLER
+	dev->mdev.dev = &pdev->dev;
+	strlcpy(dev->mdev.model, "vim2m", sizeof(dev->mdev.model));
+	media_device_init(&dev->mdev);
+	dev->v4l2_dev.mdev = &dev->mdev;
+	dev->pad[0].flags = MEDIA_PAD_FL_SINK;
+	dev->pad[1].flags = MEDIA_PAD_FL_SOURCE;
+	ret = media_entity_pads_init(&vfd->entity, 2, dev->pad);
+	if (ret)
+		return ret;
+#endif
+
+	ret = v4l2_device_register(&pdev->dev, &dev->v4l2_dev);
+	if (ret)
+		goto unreg_media;
+
 	ret = video_register_device(vfd, VFL_TYPE_GRABBER, 0);
 	if (ret) {
 		v4l2_err(&dev->v4l2_dev, "Failed to register video device\n");
@@ -1034,6 +1049,13 @@ static int vim2m_probe(struct platform_device *pdev)
 		goto err_m2m;
 	}
 
+#ifdef CONFIG_MEDIA_CONTROLLER
+	/* Register the media device node */
+	ret = media_device_register(&dev->mdev);
+	if (ret)
+		goto err_m2m;
+#endif
+
 	return 0;
 
 err_m2m:
@@ -1041,6 +1063,10 @@ static int vim2m_probe(struct platform_device *pdev)
 	video_unregister_device(&dev->vfd);
 unreg_dev:
 	v4l2_device_unregister(&dev->v4l2_dev);
+unreg_media:
+#ifdef CONFIG_MEDIA_CONTROLLER
+	media_device_unregister(&dev->mdev);
+#endif
 
 	return ret;
 }
@@ -1050,6 +1076,12 @@ static int vim2m_remove(struct platform_device *pdev)
 	struct vim2m_dev *dev = platform_get_drvdata(pdev);
 
 	v4l2_info(&dev->v4l2_dev, "Removing " MEM2MEM_NAME);
+
+#ifdef CONFIG_MEDIA_CONTROLLER
+	media_device_unregister(&dev->mdev);
+	media_device_cleanup(&dev->mdev);
+#endif
+
 	v4l2_m2m_release(dev->m2m_dev);
 	del_timer_sync(&dev->timer);
 	video_unregister_device(&dev->vfd);
-- 
2.17.0

[RFCv12 PATCH 25/29] vim2m: use workqueue

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

v4l2_ctrl uses mutexes, so we can't setup a ctrl_handler in
interrupt context. Switch to a workqueue instead.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/platform/vim2m.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/vim2m.c b/drivers/media/platform/vim2m.c
index 9be4da3b8577..a1b0bb08668d 100644
--- a/drivers/media/platform/vim2m.c
+++ b/drivers/media/platform/vim2m.c
@@ -150,6 +150,7 @@ struct vim2m_dev {
 	spinlock_t		irqlock;
 
 	struct timer_list	timer;
+	struct work_struct	work_run;
 
 	struct v4l2_m2m_dev	*m2m_dev;
 };
@@ -392,9 +393,10 @@ static void device_run(void *priv)
 	schedule_irq(dev, ctx->transtime);
 }
 
-static void device_isr(struct timer_list *t)
+static void device_work(struct work_struct *w)
 {
-	struct vim2m_dev *vim2m_dev = from_timer(vim2m_dev, t, timer);
+	struct vim2m_dev *vim2m_dev =
+		container_of(w, struct vim2m_dev, work_run);
 	struct vim2m_ctx *curr_ctx;
 	struct vb2_v4l2_buffer *src_vb, *dst_vb;
 	unsigned long flags;
@@ -426,6 +428,13 @@ static void device_isr(struct timer_list *t)
 	}
 }
 
+static void device_isr(struct timer_list *t)
+{
+	struct vim2m_dev *vim2m_dev = from_timer(vim2m_dev, t, timer);
+
+	schedule_work(&vim2m_dev->work_run);
+}
+
 /*
  * video ioctls
  */
@@ -806,6 +815,7 @@ static void vim2m_stop_streaming(struct vb2_queue *q)
 	struct vb2_v4l2_buffer *vbuf;
 	unsigned long flags;
 
+	flush_scheduled_work();
 	for (;;) {
 		if (V4L2_TYPE_IS_OUTPUT(q->type))
 			vbuf = v4l2_m2m_src_buf_remove(ctx->fh.m2m_ctx);
@@ -1011,6 +1021,7 @@ static int vim2m_probe(struct platform_device *pdev)
 	vfd = &dev->vfd;
 	vfd->lock = &dev->dev_mutex;
 	vfd->v4l2_dev = &dev->v4l2_dev;
+	INIT_WORK(&dev->work_run, device_work);
 
 #ifdef CONFIG_MEDIA_CONTROLLER
 	dev->mdev.dev = &pdev->dev;
-- 
2.17.0

[RFCv12 PATCH 26/29] vim2m: support requests

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

Add support for requests to vim2m.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/platform/vim2m.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/media/platform/vim2m.c b/drivers/media/platform/vim2m.c
index a1b0bb08668d..b6a20905beaf 100644
--- a/drivers/media/platform/vim2m.c
+++ b/drivers/media/platform/vim2m.c
@@ -387,8 +387,26 @@ static void device_run(void *priv)
 	src_buf = v4l2_m2m_next_src_buf(ctx->fh.m2m_ctx);
 	dst_buf = v4l2_m2m_next_dst_buf(ctx->fh.m2m_ctx);
 
+	/* Apply request controls if needed */
+	if (src_buf->vb2_buf.req_obj.req)
+		v4l2_ctrl_request_setup(src_buf->vb2_buf.req_obj.req,
+					&ctx->hdl);
+	if (dst_buf->vb2_buf.req_obj.req &&
+	    dst_buf->vb2_buf.req_obj.req != src_buf->vb2_buf.req_obj.req)
+		v4l2_ctrl_request_setup(dst_buf->vb2_buf.req_obj.req,
+					&ctx->hdl);
+
 	device_process(ctx, src_buf, dst_buf);
 
+	/* Complete request controls if needed */
+	if (src_buf->vb2_buf.req_obj.req)
+		v4l2_ctrl_request_complete(src_buf->vb2_buf.req_obj.req,
+					&ctx->hdl);
+	if (dst_buf->vb2_buf.req_obj.req &&
+	    dst_buf->vb2_buf.req_obj.req != src_buf->vb2_buf.req_obj.req)
+		v4l2_ctrl_request_complete(dst_buf->vb2_buf.req_obj.req,
+					&ctx->hdl);
+
 	/* Run a timer, which simulates a hardware irq  */
 	schedule_irq(dev, ctx->transtime);
 }
@@ -823,6 +841,8 @@ static void vim2m_stop_streaming(struct vb2_queue *q)
 			vbuf = v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);
 		if (vbuf == NULL)
 			return;
+		v4l2_ctrl_request_complete(vbuf->vb2_buf.req_obj.req,
+					   &ctx->hdl);
 		spin_lock_irqsave(&ctx->dev->irqlock, flags);
 		v4l2_m2m_buf_done(vbuf, VB2_BUF_STATE_ERROR);
 		spin_unlock_irqrestore(&ctx->dev->irqlock, flags);
@@ -1003,6 +1023,11 @@ static const struct v4l2_m2m_ops m2m_ops = {
 	.job_abort	= job_abort,
 };
 
+static const struct media_device_ops m2m_media_ops = {
+	.req_validate = vb2_request_validate,
+	.req_queue = vb2_m2m_request_queue,
+};
+
 static int vim2m_probe(struct platform_device *pdev)
 {
 	struct vim2m_dev *dev;
@@ -1027,6 +1052,7 @@ static int vim2m_probe(struct platform_device *pdev)
 	dev->mdev.dev = &pdev->dev;
 	strlcpy(dev->mdev.model, "vim2m", sizeof(dev->mdev.model));
 	media_device_init(&dev->mdev);
+	dev->mdev.ops = &m2m_media_ops;
 	dev->v4l2_dev.mdev = &dev->mdev;
 	dev->pad[0].flags = MEDIA_PAD_FL_SINK;
 	dev->pad[1].flags = MEDIA_PAD_FL_SOURCE;
-- 
2.17.0

[RFCv12 PATCH 27/29] vivid: add mc

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

Add support for the media_device to vivid. This is a prerequisite
for request support.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/platform/vivid/vivid-core.c | 61 +++++++++++++++++++++++
 drivers/media/platform/vivid/vivid-core.h |  8 +++
 2 files changed, 69 insertions(+)

diff --git a/drivers/media/platform/vivid/vivid-core.c b/drivers/media/platform/vivid/vivid-core.c
index 82ec216f2ad8..69386b26d5dd 100644
--- a/drivers/media/platform/vivid/vivid-core.c
+++ b/drivers/media/platform/vivid/vivid-core.c
@@ -657,6 +657,15 @@ static int vivid_create_instance(struct platform_device *pdev, int inst)
 
 	dev->inst = inst;
 
+#ifdef CONFIG_MEDIA_CONTROLLER
+	dev->v4l2_dev.mdev = &dev->mdev;
+
+	/* Initialize media device */
+	strlcpy(dev->mdev.model, VIVID_MODULE_NAME, sizeof(dev->mdev.model));
+	dev->mdev.dev = &pdev->dev;
+	media_device_init(&dev->mdev);
+#endif
+
 	/* register v4l2_device */
 	snprintf(dev->v4l2_dev.name, sizeof(dev->v4l2_dev.name),
 			"%s-%03d", VIVID_MODULE_NAME, inst);
@@ -1173,6 +1182,13 @@ static int vivid_create_instance(struct platform_device *pdev, int inst)
 		vfd->lock = &dev->mutex;
 		video_set_drvdata(vfd, dev);
 
+#ifdef CONFIG_MEDIA_CONTROLLER
+		dev->vid_cap_pad.flags = MEDIA_PAD_FL_SINK;
+		ret = media_entity_pads_init(&vfd->entity, 1, &dev->vid_cap_pad);
+		if (ret)
+			goto unreg_dev;
+#endif
+
 #ifdef CONFIG_VIDEO_VIVID_CEC
 		if (in_type_counter[HDMI]) {
 			struct cec_adapter *adap;
@@ -1225,6 +1241,13 @@ static int vivid_create_instance(struct platform_device *pdev, int inst)
 		vfd->lock = &dev->mutex;
 		video_set_drvdata(vfd, dev);
 
+#ifdef CONFIG_MEDIA_CONTROLLER
+		dev->vid_out_pad.flags = MEDIA_PAD_FL_SOURCE;
+		ret = media_entity_pads_init(&vfd->entity, 1, &dev->vid_out_pad);
+		if (ret)
+			goto unreg_dev;
+#endif
+
 #ifdef CONFIG_VIDEO_VIVID_CEC
 		for (i = 0; i < dev->num_outputs; i++) {
 			struct cec_adapter *adap;
@@ -1274,6 +1297,13 @@ static int vivid_create_instance(struct platform_device *pdev, int inst)
 		vfd->tvnorms = tvnorms_cap;
 		video_set_drvdata(vfd, dev);
 
+#ifdef CONFIG_MEDIA_CONTROLLER
+		dev->vbi_cap_pad.flags = MEDIA_PAD_FL_SINK;
+		ret = media_entity_pads_init(&vfd->entity, 1, &dev->vbi_cap_pad);
+		if (ret)
+			goto unreg_dev;
+#endif
+
 		ret = video_register_device(vfd, VFL_TYPE_VBI, vbi_cap_nr[inst]);
 		if (ret < 0)
 			goto unreg_dev;
@@ -1299,6 +1329,13 @@ static int vivid_create_instance(struct platform_device *pdev, int inst)
 		vfd->tvnorms = tvnorms_out;
 		video_set_drvdata(vfd, dev);
 
+#ifdef CONFIG_MEDIA_CONTROLLER
+		dev->vbi_out_pad.flags = MEDIA_PAD_FL_SOURCE;
+		ret = media_entity_pads_init(&vfd->entity, 1, &dev->vbi_out_pad);
+		if (ret)
+			goto unreg_dev;
+#endif
+
 		ret = video_register_device(vfd, VFL_TYPE_VBI, vbi_out_nr[inst]);
 		if (ret < 0)
 			goto unreg_dev;
@@ -1322,6 +1359,13 @@ static int vivid_create_instance(struct platform_device *pdev, int inst)
 		vfd->lock = &dev->mutex;
 		video_set_drvdata(vfd, dev);
 
+#ifdef CONFIG_MEDIA_CONTROLLER
+		dev->sdr_cap_pad.flags = MEDIA_PAD_FL_SINK;
+		ret = media_entity_pads_init(&vfd->entity, 1, &dev->sdr_cap_pad);
+		if (ret)
+			goto unreg_dev;
+#endif
+
 		ret = video_register_device(vfd, VFL_TYPE_SDR, sdr_cap_nr[inst]);
 		if (ret < 0)
 			goto unreg_dev;
@@ -1368,12 +1412,25 @@ static int vivid_create_instance(struct platform_device *pdev, int inst)
 					  video_device_node_name(vfd));
 	}
 
+#ifdef CONFIG_MEDIA_CONTROLLER
+	/* Register the media device */
+	ret = media_device_register(&dev->mdev);
+	if (ret) {
+		dev_err(dev->mdev.dev,
+			"media device register failed (err=%d)\n", ret);
+		goto unreg_dev;
+	}
+#endif
+
 	/* Now that everything is fine, let's add it to device list */
 	vivid_devs[inst] = dev;
 
 	return 0;
 
 unreg_dev:
+#ifdef CONFIG_MEDIA_CONTROLLER
+	media_device_unregister(&dev->mdev);
+#endif
 	video_unregister_device(&dev->radio_tx_dev);
 	video_unregister_device(&dev->radio_rx_dev);
 	video_unregister_device(&dev->sdr_cap_dev);
@@ -1444,6 +1501,10 @@ static int vivid_remove(struct platform_device *pdev)
 		if (!dev)
 			continue;
 
+#ifdef CONFIG_MEDIA_CONTROLLER
+		media_device_unregister(&dev->mdev);
+#endif
+
 		if (dev->has_vid_cap) {
 			v4l2_info(&dev->v4l2_dev, "unregistering %s\n",
 				video_device_node_name(&dev->vid_cap_dev));
diff --git a/drivers/media/platform/vivid/vivid-core.h b/drivers/media/platform/vivid/vivid-core.h
index 477c80a4d44c..6ccd1f5c1d91 100644
--- a/drivers/media/platform/vivid/vivid-core.h
+++ b/drivers/media/platform/vivid/vivid-core.h
@@ -136,6 +136,14 @@ struct vivid_cec_work {
 struct vivid_dev {
 	unsigned			inst;
 	struct v4l2_device		v4l2_dev;
+#ifdef CONFIG_MEDIA_CONTROLLER
+	struct media_device		mdev;
+	struct media_pad		vid_cap_pad;
+	struct media_pad		vid_out_pad;
+	struct media_pad		vbi_cap_pad;
+	struct media_pad		vbi_out_pad;
+	struct media_pad		sdr_cap_pad;
+#endif
 	struct v4l2_ctrl_handler	ctrl_hdl_user_gen;
 	struct v4l2_ctrl_handler	ctrl_hdl_user_vid;
 	struct v4l2_ctrl_handler	ctrl_hdl_user_aud;
-- 
2.17.0

[RFCv12 PATCH 28/29] vivid: add request support

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

Add support for requests to vivid.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/platform/vivid/vivid-core.c        |  8 ++++++++
 drivers/media/platform/vivid/vivid-kthread-cap.c | 12 ++++++++++++
 drivers/media/platform/vivid/vivid-kthread-out.c | 12 ++++++++++++
 drivers/media/platform/vivid/vivid-sdr-cap.c     |  8 ++++++++
 drivers/media/platform/vivid/vivid-vbi-cap.c     |  2 ++
 drivers/media/platform/vivid/vivid-vbi-out.c     |  2 ++
 drivers/media/platform/vivid/vivid-vid-cap.c     |  2 ++
 drivers/media/platform/vivid/vivid-vid-out.c     |  2 ++
 8 files changed, 48 insertions(+)

diff --git a/drivers/media/platform/vivid/vivid-core.c b/drivers/media/platform/vivid/vivid-core.c
index 69386b26d5dd..a84c7e37c22b 100644
--- a/drivers/media/platform/vivid/vivid-core.c
+++ b/drivers/media/platform/vivid/vivid-core.c
@@ -627,6 +627,13 @@ static void vivid_dev_release(struct v4l2_device *v4l2_dev)
 	kfree(dev);
 }
 
+#ifdef CONFIG_MEDIA_CONTROLLER
+static const struct media_device_ops vivid_media_ops = {
+	.req_validate = vb2_request_validate,
+	.req_queue = vb2_request_queue,
+};
+#endif
+
 static int vivid_create_instance(struct platform_device *pdev, int inst)
 {
 	static const struct v4l2_dv_timings def_dv_timings =
@@ -664,6 +671,7 @@ static int vivid_create_instance(struct platform_device *pdev, int inst)
 	strlcpy(dev->mdev.model, VIVID_MODULE_NAME, sizeof(dev->mdev.model));
 	dev->mdev.dev = &pdev->dev;
 	media_device_init(&dev->mdev);
+	dev->mdev.ops = &vivid_media_ops;
 #endif
 
 	/* register v4l2_device */
diff --git a/drivers/media/platform/vivid/vivid-kthread-cap.c b/drivers/media/platform/vivid/vivid-kthread-cap.c
index 3fdb280c36ca..c192b4b1b9de 100644
--- a/drivers/media/platform/vivid/vivid-kthread-cap.c
+++ b/drivers/media/platform/vivid/vivid-kthread-cap.c
@@ -703,6 +703,8 @@ static void vivid_thread_vid_cap_tick(struct vivid_dev *dev, int dropped_bufs)
 		goto update_mv;
 
 	if (vid_cap_buf) {
+		v4l2_ctrl_request_setup(vid_cap_buf->vb.vb2_buf.req_obj.req,
+					&dev->ctrl_hdl_vid_cap);
 		/* Fill buffer */
 		vivid_fillbuff(dev, vid_cap_buf);
 		dprintk(dev, 1, "filled buffer %d\n",
@@ -713,6 +715,8 @@ static void vivid_thread_vid_cap_tick(struct vivid_dev *dev, int dropped_bufs)
 			dev->fb_cap.fmt.pixelformat == dev->fmt_cap->fourcc)
 			vivid_overlay(dev, vid_cap_buf);
 
+		v4l2_ctrl_request_complete(vid_cap_buf->vb.vb2_buf.req_obj.req,
+					   &dev->ctrl_hdl_vid_cap);
 		vb2_buffer_done(&vid_cap_buf->vb.vb2_buf, dev->dqbuf_error ?
 				VB2_BUF_STATE_ERROR : VB2_BUF_STATE_DONE);
 		dprintk(dev, 2, "vid_cap buffer %d done\n",
@@ -720,10 +724,14 @@ static void vivid_thread_vid_cap_tick(struct vivid_dev *dev, int dropped_bufs)
 	}
 
 	if (vbi_cap_buf) {
+		v4l2_ctrl_request_setup(vbi_cap_buf->vb.vb2_buf.req_obj.req,
+					&dev->ctrl_hdl_vbi_cap);
 		if (dev->stream_sliced_vbi_cap)
 			vivid_sliced_vbi_cap_process(dev, vbi_cap_buf);
 		else
 			vivid_raw_vbi_cap_process(dev, vbi_cap_buf);
+		v4l2_ctrl_request_complete(vbi_cap_buf->vb.vb2_buf.req_obj.req,
+					   &dev->ctrl_hdl_vbi_cap);
 		vb2_buffer_done(&vbi_cap_buf->vb.vb2_buf, dev->dqbuf_error ?
 				VB2_BUF_STATE_ERROR : VB2_BUF_STATE_DONE);
 		dprintk(dev, 2, "vbi_cap %d done\n",
@@ -891,6 +899,8 @@ void vivid_stop_generating_vid_cap(struct vivid_dev *dev, bool *pstreaming)
 			buf = list_entry(dev->vid_cap_active.next,
 					 struct vivid_buffer, list);
 			list_del(&buf->list);
+			v4l2_ctrl_request_complete(buf->vb.vb2_buf.req_obj.req,
+						   &dev->ctrl_hdl_vid_cap);
 			vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
 			dprintk(dev, 2, "vid_cap buffer %d done\n",
 				buf->vb.vb2_buf.index);
@@ -904,6 +914,8 @@ void vivid_stop_generating_vid_cap(struct vivid_dev *dev, bool *pstreaming)
 			buf = list_entry(dev->vbi_cap_active.next,
 					 struct vivid_buffer, list);
 			list_del(&buf->list);
+			v4l2_ctrl_request_complete(buf->vb.vb2_buf.req_obj.req,
+						   &dev->ctrl_hdl_vbi_cap);
 			vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
 			dprintk(dev, 2, "vbi_cap buffer %d done\n",
 				buf->vb.vb2_buf.index);
diff --git a/drivers/media/platform/vivid/vivid-kthread-out.c b/drivers/media/platform/vivid/vivid-kthread-out.c
index 9981e7548019..5a14810eeb69 100644
--- a/drivers/media/platform/vivid/vivid-kthread-out.c
+++ b/drivers/media/platform/vivid/vivid-kthread-out.c
@@ -75,6 +75,10 @@ static void vivid_thread_vid_out_tick(struct vivid_dev *dev)
 		return;
 
 	if (vid_out_buf) {
+		v4l2_ctrl_request_setup(vid_out_buf->vb.vb2_buf.req_obj.req,
+					&dev->ctrl_hdl_vid_out);
+		v4l2_ctrl_request_complete(vid_out_buf->vb.vb2_buf.req_obj.req,
+					   &dev->ctrl_hdl_vid_out);
 		vid_out_buf->vb.sequence = dev->vid_out_seq_count;
 		if (dev->field_out == V4L2_FIELD_ALTERNATE) {
 			/*
@@ -92,6 +96,10 @@ static void vivid_thread_vid_out_tick(struct vivid_dev *dev)
 	}
 
 	if (vbi_out_buf) {
+		v4l2_ctrl_request_setup(vbi_out_buf->vb.vb2_buf.req_obj.req,
+					&dev->ctrl_hdl_vbi_out);
+		v4l2_ctrl_request_complete(vbi_out_buf->vb.vb2_buf.req_obj.req,
+					   &dev->ctrl_hdl_vbi_out);
 		if (dev->stream_sliced_vbi_out)
 			vivid_sliced_vbi_out_process(dev, vbi_out_buf);
 
@@ -262,6 +270,8 @@ void vivid_stop_generating_vid_out(struct vivid_dev *dev, bool *pstreaming)
 			buf = list_entry(dev->vid_out_active.next,
 					 struct vivid_buffer, list);
 			list_del(&buf->list);
+			v4l2_ctrl_request_complete(buf->vb.vb2_buf.req_obj.req,
+						   &dev->ctrl_hdl_vid_out);
 			vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
 			dprintk(dev, 2, "vid_out buffer %d done\n",
 				buf->vb.vb2_buf.index);
@@ -275,6 +285,8 @@ void vivid_stop_generating_vid_out(struct vivid_dev *dev, bool *pstreaming)
 			buf = list_entry(dev->vbi_out_active.next,
 					 struct vivid_buffer, list);
 			list_del(&buf->list);
+			v4l2_ctrl_request_complete(buf->vb.vb2_buf.req_obj.req,
+						   &dev->ctrl_hdl_vbi_out);
 			vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
 			dprintk(dev, 2, "vbi_out buffer %d done\n",
 				buf->vb.vb2_buf.index);
diff --git a/drivers/media/platform/vivid/vivid-sdr-cap.c b/drivers/media/platform/vivid/vivid-sdr-cap.c
index cfb7cb4d37a8..2c466cc4080d 100644
--- a/drivers/media/platform/vivid/vivid-sdr-cap.c
+++ b/drivers/media/platform/vivid/vivid-sdr-cap.c
@@ -102,6 +102,10 @@ static void vivid_thread_sdr_cap_tick(struct vivid_dev *dev)
 
 	if (sdr_cap_buf) {
 		sdr_cap_buf->vb.sequence = dev->sdr_cap_seq_count;
+		v4l2_ctrl_request_setup(sdr_cap_buf->vb.vb2_buf.req_obj.req,
+					&dev->ctrl_hdl_sdr_cap);
+		v4l2_ctrl_request_complete(sdr_cap_buf->vb.vb2_buf.req_obj.req,
+					   &dev->ctrl_hdl_sdr_cap);
 		vivid_sdr_cap_process(dev, sdr_cap_buf);
 		sdr_cap_buf->vb.vb2_buf.timestamp =
 			ktime_get_ns() + dev->time_wrap_offset;
@@ -272,6 +276,8 @@ static int sdr_cap_start_streaming(struct vb2_queue *vq, unsigned count)
 
 		list_for_each_entry_safe(buf, tmp, &dev->sdr_cap_active, list) {
 			list_del(&buf->list);
+			v4l2_ctrl_request_complete(buf->vb.vb2_buf.req_obj.req,
+						   &dev->ctrl_hdl_sdr_cap);
 			vb2_buffer_done(&buf->vb.vb2_buf,
 					VB2_BUF_STATE_QUEUED);
 		}
@@ -293,6 +299,8 @@ static void sdr_cap_stop_streaming(struct vb2_queue *vq)
 		buf = list_entry(dev->sdr_cap_active.next,
 				struct vivid_buffer, list);
 		list_del(&buf->list);
+		v4l2_ctrl_request_complete(buf->vb.vb2_buf.req_obj.req,
+					   &dev->ctrl_hdl_sdr_cap);
 		vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
 	}
 
diff --git a/drivers/media/platform/vivid/vivid-vbi-cap.c b/drivers/media/platform/vivid/vivid-vbi-cap.c
index 92a852955173..c5601639a0f3 100644
--- a/drivers/media/platform/vivid/vivid-vbi-cap.c
+++ b/drivers/media/platform/vivid/vivid-vbi-cap.c
@@ -204,6 +204,8 @@ static int vbi_cap_start_streaming(struct vb2_queue *vq, unsigned count)
 
 		list_for_each_entry_safe(buf, tmp, &dev->vbi_cap_active, list) {
 			list_del(&buf->list);
+			v4l2_ctrl_request_complete(buf->vb.vb2_buf.req_obj.req,
+						   &dev->ctrl_hdl_vbi_cap);
 			vb2_buffer_done(&buf->vb.vb2_buf,
 					VB2_BUF_STATE_QUEUED);
 		}
diff --git a/drivers/media/platform/vivid/vivid-vbi-out.c b/drivers/media/platform/vivid/vivid-vbi-out.c
index 69486c130a7e..7c06bbf5fc7a 100644
--- a/drivers/media/platform/vivid/vivid-vbi-out.c
+++ b/drivers/media/platform/vivid/vivid-vbi-out.c
@@ -96,6 +96,8 @@ static int vbi_out_start_streaming(struct vb2_queue *vq, unsigned count)
 
 		list_for_each_entry_safe(buf, tmp, &dev->vbi_out_active, list) {
 			list_del(&buf->list);
+			v4l2_ctrl_request_complete(buf->vb.vb2_buf.req_obj.req,
+						   &dev->ctrl_hdl_vbi_out);
 			vb2_buffer_done(&buf->vb.vb2_buf,
 					VB2_BUF_STATE_QUEUED);
 		}
diff --git a/drivers/media/platform/vivid/vivid-vid-cap.c b/drivers/media/platform/vivid/vivid-vid-cap.c
index 1599159f2574..ca9e05594990 100644
--- a/drivers/media/platform/vivid/vivid-vid-cap.c
+++ b/drivers/media/platform/vivid/vivid-vid-cap.c
@@ -240,6 +240,8 @@ static int vid_cap_start_streaming(struct vb2_queue *vq, unsigned count)
 
 		list_for_each_entry_safe(buf, tmp, &dev->vid_cap_active, list) {
 			list_del(&buf->list);
+			v4l2_ctrl_request_complete(buf->vb.vb2_buf.req_obj.req,
+						   &dev->ctrl_hdl_vid_cap);
 			vb2_buffer_done(&buf->vb.vb2_buf,
 					VB2_BUF_STATE_QUEUED);
 		}
diff --git a/drivers/media/platform/vivid/vivid-vid-out.c b/drivers/media/platform/vivid/vivid-vid-out.c
index 51fec66d8d45..b53805fca7b4 100644
--- a/drivers/media/platform/vivid/vivid-vid-out.c
+++ b/drivers/media/platform/vivid/vivid-vid-out.c
@@ -162,6 +162,8 @@ static int vid_out_start_streaming(struct vb2_queue *vq, unsigned count)
 
 		list_for_each_entry_safe(buf, tmp, &dev->vid_out_active, list) {
 			list_del(&buf->list);
+			v4l2_ctrl_request_complete(buf->vb.vb2_buf.req_obj.req,
+						   &dev->ctrl_hdl_vid_out);
 			vb2_buffer_done(&buf->vb.vb2_buf,
 					VB2_BUF_STATE_QUEUED);
 		}
-- 
2.17.0

[RFCv12 PATCH 29/29] RFC: media-requests: add debugfs node

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

Keep track of the number of requests and request objects of a media
device. Helps to verify that all request-related memory is freed.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/media-device.c  | 41 +++++++++++++++++++++++++++++++++++
 drivers/media/media-devnode.c | 17 +++++++++++++++
 drivers/media/media-request.c |  5 +++++
 include/media/media-device.h  | 11 ++++++++++
 include/media/media-devnode.h |  4 ++++
 include/media/media-request.h |  1 +
 6 files changed, 79 insertions(+)

diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
index 25d7e2a3ee84..522bb5bfb75a 100644
--- a/drivers/media/media-device.c
+++ b/drivers/media/media-device.c
@@ -680,6 +680,23 @@ void media_device_unregister_entity(struct media_entity *entity)
 }
 EXPORT_SYMBOL_GPL(media_device_unregister_entity);
 
+#ifdef CONFIG_DEBUG_FS
+/*
+ * Log the state of media requests.
+ * Very useful for debugging.
+ */
+static int media_device_requests(struct seq_file *file, void *priv)
+{
+	struct media_device *dev = dev_get_drvdata(file->private);
+
+	seq_printf(file, "number of requests: %d\n",
+		   atomic_read(&dev->num_requests));
+	seq_printf(file, "number of request objects: %d\n",
+		   atomic_read(&dev->num_request_objects));
+	return 0;
+}
+#endif
+
 /**
  * media_device_init() - initialize a media device
  * @mdev:	The media device
@@ -702,6 +719,9 @@ void media_device_init(struct media_device *mdev)
 	mutex_init(&mdev->graph_mutex);
 	ida_init(&mdev->entity_internal_idx);
 
+	atomic_set(&mdev->num_requests, 0);
+	atomic_set(&mdev->num_request_objects, 0);
+
 	dev_dbg(mdev->dev, "Media device initialized\n");
 }
 EXPORT_SYMBOL_GPL(media_device_init);
@@ -752,6 +772,26 @@ int __must_check __media_device_register(struct media_device *mdev,
 
 	dev_dbg(mdev->dev, "Media device registered\n");
 
+#ifdef CONFIG_DEBUG_FS
+	if (!media_top_dir)
+		return 0;
+
+	mdev->media_dir = debugfs_create_dir(dev_name(&devnode->dev),
+					     media_top_dir);
+	if (IS_ERR_OR_NULL(mdev->media_dir)) {
+		dev_warn(mdev->dev, "Failed to create debugfs dir\n");
+		return 0;
+	}
+	mdev->requests_file = debugfs_create_devm_seqfile(&devnode->dev,
+		"requests", mdev->media_dir, media_device_requests);
+	if (IS_ERR_OR_NULL(mdev->requests_file)) {
+		dev_warn(mdev->dev, "Failed to create requests file\n");
+		debugfs_remove_recursive(mdev->media_dir);
+		mdev->media_dir = NULL;
+		return 0;
+	}
+#endif
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(__media_device_register);
@@ -829,6 +869,7 @@ void media_device_unregister(struct media_device *mdev)
 
 	dev_dbg(mdev->dev, "Media device unregistered\n");
 
+	debugfs_remove_recursive(mdev->media_dir);
 	device_remove_file(&mdev->devnode->dev, &dev_attr_model);
 	media_devnode_unregister(mdev->devnode);
 	/* devnode free is handled in media_devnode_*() */
diff --git a/drivers/media/media-devnode.c b/drivers/media/media-devnode.c
index 67ac51eff15c..2656c2d7a312 100644
--- a/drivers/media/media-devnode.c
+++ b/drivers/media/media-devnode.c
@@ -53,6 +53,12 @@ static dev_t media_dev_t;
 static DEFINE_MUTEX(media_devnode_lock);
 static DECLARE_BITMAP(media_devnode_nums, MEDIA_NUM_DEVICES);
 
+/*
+ * debugfs
+ */
+struct dentry *media_top_dir;
+
+
 /* Called when the last user of the media device exits. */
 static void media_devnode_release(struct device *cd)
 {
@@ -259,6 +265,8 @@ int __must_check media_devnode_register(struct media_device *mdev,
 		goto cdev_add_error;
 	}
 
+	dev_set_drvdata(&devnode->dev, mdev);
+
 	/* Part 4: Activate this minor. The char device can now be used. */
 	set_bit(MEDIA_FLAG_REGISTERED, &devnode->flags);
 
@@ -310,6 +318,14 @@ static int __init media_devnode_init(void)
 		return ret;
 	}
 
+#ifdef CONFIG_DEBUG_FS
+	media_top_dir = debugfs_create_dir("media", NULL);
+	if (IS_ERR_OR_NULL(media_top_dir)) {
+		pr_warn("Failed to create debugfs media dir\n");
+		media_top_dir = NULL;
+	}
+#endif
+
 	ret = bus_register(&media_bus_type);
 	if (ret < 0) {
 		unregister_chrdev_region(media_dev_t, MEDIA_NUM_DEVICES);
@@ -322,6 +338,7 @@ static int __init media_devnode_init(void)
 
 static void __exit media_devnode_exit(void)
 {
+	debugfs_remove_recursive(media_top_dir);
 	bus_unregister(&media_bus_type);
 	unregister_chrdev_region(media_dev_t, MEDIA_NUM_DEVICES);
 }
diff --git a/drivers/media/media-request.c b/drivers/media/media-request.c
index 9815fb6445dc..cc95c34e83dd 100644
--- a/drivers/media/media-request.c
+++ b/drivers/media/media-request.c
@@ -61,6 +61,7 @@ static void media_request_release(struct kref *kref)
 		mdev->ops->req_free(req);
 	else
 		kfree(req);
+	atomic_dec(&mdev->num_requests);
 }
 
 void media_request_put(struct media_request *req)
@@ -324,6 +325,7 @@ int media_request_alloc(struct media_device *mdev,
 	get_task_comm(comm, current);
 	snprintf(req->debug_str, sizeof(req->debug_str), "%s:%d",
 		 comm, fd);
+	atomic_inc(&mdev->num_requests);
 	dev_dbg(mdev->dev, "request: allocated %s\n", req->debug_str);
 
 	fd_install(fd, filp);
@@ -348,6 +350,7 @@ static void media_request_object_release(struct kref *kref)
 	if (req)
 		media_request_object_unbind(obj);
 	obj->ops->release(obj);
+	atomic_dec(&obj->mdev->num_request_objects);
 }
 
 struct media_request_object *
@@ -406,12 +409,14 @@ int media_request_object_bind(struct media_request *req,
 	obj->req = req;
 	obj->ops = ops;
 	obj->priv = priv;
+	obj->mdev = req->mdev;
 	spin_lock_irqsave(&req->lock, flags);
 	if (WARN_ON(atomic_read(&req->state) != MEDIA_REQUEST_STATE_IDLE))
 		goto unlock;
 	list_add_tail(&obj->list, &req->objects);
 	req->num_incomplete_objects++;
 	ret = 0;
+	atomic_inc(&obj->mdev->num_request_objects);
 unlock:
 	spin_unlock_irqrestore(&req->lock, flags);
 	return ret;
diff --git a/include/media/media-device.h b/include/media/media-device.h
index ae846208be51..54b3cd346ea5 100644
--- a/include/media/media-device.h
+++ b/include/media/media-device.h
@@ -21,6 +21,7 @@
 
 #include <linux/list.h>
 #include <linux/mutex.h>
+#include <linux/atomic.h>
 
 #include <media/media-devnode.h>
 #include <media/media-entity.h>
@@ -103,6 +104,10 @@ struct media_device_ops {
  * @ops:	Operation handler callbacks
  * @req_queue_mutex: Serialise the MEDIA_REQUEST_IOC_QUEUE ioctl w.r.t. this
  *		     media device.
+ * @num_request:	number of associated requests
+ * @num_request_objects: number of associated request objects
+ * @media_dir:	DebugFS media directory
+ * @requests_file: DebugFS requests file
  *
  * This structure represents an abstract high-level media device. It allows easy
  * access to entities and provides basic media device-level support. The
@@ -175,6 +180,12 @@ struct media_device {
 	const struct media_device_ops *ops;
 
 	struct mutex req_queue_mutex;
+	atomic_t num_requests;
+	atomic_t num_request_objects;
+
+	/* debugfs */
+	struct dentry *media_dir;
+	struct dentry *requests_file;
 };
 
 /* We don't need to include pci.h or usb.h here */
diff --git a/include/media/media-devnode.h b/include/media/media-devnode.h
index dc2f64e1b08f..984b62b634d3 100644
--- a/include/media/media-devnode.h
+++ b/include/media/media-devnode.h
@@ -28,9 +28,13 @@
 #include <linux/fs.h>
 #include <linux/device.h>
 #include <linux/cdev.h>
+#include <linux/debugfs.h>
 
 struct media_device;
 
+/* DebugFS top-level media directory */
+extern struct dentry *media_top_dir;
+
 /*
  * Flag to mark the media_devnode struct as registered. Drivers must not touch
  * this flag directly, it will be set and cleared by media_devnode_register and
diff --git a/include/media/media-request.h b/include/media/media-request.h
index 6ecc89fcf4a2..0d446d00a092 100644
--- a/include/media/media-request.h
+++ b/include/media/media-request.h
@@ -120,6 +120,7 @@ struct media_request_object_ops {
  * larger object data.
  */
 struct media_request_object {
+	struct media_device *mdev;
 	const struct media_request_object_ops *ops;
 	void *priv;
 	struct media_request *req;
-- 
2.17.0

Re: [RFCv12 PATCH 04/29] v4l2-dev: lock req_queue_mutex

[Hans Verkuil]

On 01/05/18 11:00, Hans Verkuil wrote:
> From: Hans Verkuil <hans.verkuil@cisco.com>
> 

Oops, missing commit log. That should be:

We need to serialize streamon/off with queueing new requests.
These ioctls may trigger the cancellation of a streaming
operation, and that should not be mixed with queuing a new
request at the same time.

Also TRY/S_EXT_CTRLS needs this lock to correctly serialize
with MEDIA_REQUEST_IOC_QUEUE.

Finally close() needs this lock since that too can trigger the
cancellation of a streaming operation.

We take the req_queue_mutex here before any other locks since
it is a very high-level lock.

	Hans

> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
> ---
>  drivers/media/v4l2-core/v4l2-dev.c | 37 +++++++++++++++++++++++++++++-
>  1 file changed, 36 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c
> index 1d0b2208e8fb..3368bd5537a7 100644
> --- a/drivers/media/v4l2-core/v4l2-dev.c
> +++ b/drivers/media/v4l2-core/v4l2-dev.c
> @@ -353,13 +353,36 @@ static long v4l2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
>  
>  	if (vdev->fops->unlocked_ioctl) {
>  		struct mutex *lock = v4l2_ioctl_get_lock(vdev, cmd);
> +		struct mutex *queue_lock = NULL;
>  
> -		if (lock && mutex_lock_interruptible(lock))
> +		/*
> +		 * We need to serialize streamon/off with queuing new requests.
> +		 * These ioctls may trigger the cancellation of a streaming
> +		 * operation, and that should not be mixed with queuing a new
> +		 * request at the same time.
> +		 *
> +		 * Also TRY/S_EXT_CTRLS needs this lock to correctly serialize
> +		 * with MEDIA_REQUEST_IOC_QUEUE.
> +		 */
> +		if (vdev->v4l2_dev->mdev &&
> +		    (cmd == VIDIOC_STREAMON || cmd == VIDIOC_STREAMOFF ||
> +		     cmd == VIDIOC_S_EXT_CTRLS || cmd == VIDIOC_TRY_EXT_CTRLS))
> +			queue_lock = &vdev->v4l2_dev->mdev->req_queue_mutex;
> +
> +		if (queue_lock && mutex_lock_interruptible(queue_lock))
> +			return -ERESTARTSYS;
> +
> +		if (lock && mutex_lock_interruptible(lock)) {
> +			if (queue_lock)
> +				mutex_unlock(queue_lock);
>  			return -ERESTARTSYS;
> +		}
>  		if (video_is_registered(vdev))
>  			ret = vdev->fops->unlocked_ioctl(filp, cmd, arg);
>  		if (lock)
>  			mutex_unlock(lock);
> +		if (queue_lock)
> +			mutex_unlock(queue_lock);
>  	} else
>  		ret = -ENOTTY;
>  
> @@ -442,8 +465,20 @@ static int v4l2_release(struct inode *inode, struct file *filp)
>  	struct video_device *vdev = video_devdata(filp);
>  	int ret = 0;
>  
> +	/*
> +	 * We need to serialize the release() with queuing new requests.
> +	 * The release() may trigger the cancellation of a streaming
> +	 * operation, and that should not be mixed with queuing a new
> +	 * request at the same time.
> +	 */
> +	if (vdev->v4l2_dev->mdev)
> +		mutex_lock(&vdev->v4l2_dev->mdev->req_queue_mutex);
> +
>  	if (vdev->fops->release)
>  		ret = vdev->fops->release(filp);
> +
> +	if (vdev->v4l2_dev->mdev)
> +		mutex_unlock(&vdev->v4l2_dev->mdev->req_queue_mutex);
>  	if (vdev->dev_debug & V4L2_DEV_DEBUG_FOP)
>  		printk(KERN_DEBUG "%s: release\n",
>  			video_device_node_name(vdev));
> 

Re: [RFCv12 PATCH 21/29] videobuf2-v4l2: export request_fd

[Hans Verkuil]

On 01/05/18 11:00, Hans Verkuil wrote:
> From: Hans Verkuil <hans.verkuil@cisco.com>
> 
> Requested by Sakari

This should have been merged with patch 18, I forgot about that. Will be done in v13.

Regards,

	Hans

> 
> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
> ---
>  drivers/media/common/videobuf2/videobuf2-v4l2.c | 6 ++++--
>  include/media/videobuf2-v4l2.h                  | 2 ++
>  2 files changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> index 7fced0a503f4..b6142041418e 100644
> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> @@ -184,6 +184,7 @@ static int vb2_fill_vb2_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b
>  		return -EINVAL;
>  	}
>  	vbuf->sequence = 0;
> +	vbuf->request_fd = -1;
>  
>  	if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
>  		switch (b->memory) {
> @@ -399,6 +400,7 @@ static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *md
>  	}
>  
>  	*p_req = req;
> +	vbuf->request_fd = b->request_fd;
>  
>  	return 0;
>  }
> @@ -504,9 +506,9 @@ static void __fill_v4l2_buffer(struct vb2_buffer *vb, void *pb)
>  
>  	if (vb2_buffer_in_use(q, vb))
>  		b->flags |= V4L2_BUF_FLAG_MAPPED;
> -	if (vb->req_obj.req) {
> +	if (vbuf->request_fd >= 0) {
>  		b->flags |= V4L2_BUF_FLAG_REQUEST_FD;
> -		b->request_fd = -1;
> +		b->request_fd = vbuf->request_fd;
>  	}
>  
>  	if (!q->is_output &&
> diff --git a/include/media/videobuf2-v4l2.h b/include/media/videobuf2-v4l2.h
> index 33210221a621..727855463838 100644
> --- a/include/media/videobuf2-v4l2.h
> +++ b/include/media/videobuf2-v4l2.h
> @@ -32,6 +32,7 @@
>   *		&enum v4l2_field.
>   * @timecode:	frame timecode.
>   * @sequence:	sequence count of this frame.
> + * @request_fd:	the request_fd associated with this buffer
>   * @planes:	plane information (userptr/fd, length, bytesused, data_offset).
>   *
>   * Should contain enough information to be able to cover all the fields
> @@ -44,6 +45,7 @@ struct vb2_v4l2_buffer {
>  	__u32			field;
>  	struct v4l2_timecode	timecode;
>  	__u32			sequence;
> +	__s32			request_fd;
>  	struct vb2_plane	planes[VB2_MAX_PLANES];
>  };
>  
> 

Re: [RFCv12 PATCH 03/29] media-request: implement media requests

[Hans Verkuil]

On 01/05/18 11:00, Hans Verkuil wrote:
> From: Hans Verkuil <hans.verkuil@cisco.com>
> 
> Add initial media request support.
> 
> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
> ---
>  drivers/media/Makefile        |   3 +-
>  drivers/media/media-device.c  |  13 ++
>  drivers/media/media-request.c | 418 ++++++++++++++++++++++++++++++++++
>  include/media/media-device.h  |  17 ++
>  include/media/media-request.h | 193 ++++++++++++++++
>  5 files changed, 643 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/media/media-request.c
>  create mode 100644 include/media/media-request.h
> 
> diff --git a/drivers/media/Makefile b/drivers/media/Makefile
> index 594b462ddf0e..985d35ec6b29 100644
> --- a/drivers/media/Makefile
> +++ b/drivers/media/Makefile
> @@ -3,7 +3,8 @@
>  # Makefile for the kernel multimedia device drivers.
>  #
>  
> -media-objs	:= media-device.o media-devnode.o media-entity.o
> +media-objs	:= media-device.o media-devnode.o media-entity.o \
> +		   media-request.o
>  
>  #
>  # I2C drivers should come before other drivers, otherwise they'll fail
> diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
> index 35e81f7c0d2f..25d7e2a3ee84 100644
> --- a/drivers/media/media-device.c
> +++ b/drivers/media/media-device.c
> @@ -32,6 +32,7 @@
>  #include <media/media-device.h>
>  #include <media/media-devnode.h>
>  #include <media/media-entity.h>
> +#include <media/media-request.h>
>  
>  #ifdef CONFIG_MEDIA_CONTROLLER
>  
> @@ -366,6 +367,15 @@ static long media_device_get_topology(struct media_device *mdev,
>  	return ret;
>  }
>  
> +static long media_device_request_alloc(struct media_device *mdev,
> +				       struct media_request_alloc *alloc)
> +{
> +	if (!mdev->ops || !mdev->ops->req_validate || !mdev->ops->req_queue)
> +		return -ENOTTY;
> +
> +	return media_request_alloc(mdev, alloc);
> +}
> +
>  static long copy_arg_from_user(void *karg, void __user *uarg, unsigned int cmd)
>  {
>  	/* All media IOCTLs are _IOWR() */
> @@ -414,6 +424,7 @@ static const struct media_ioctl_info ioctl_info[] = {
>  	MEDIA_IOC(ENUM_LINKS, media_device_enum_links, MEDIA_IOC_FL_GRAPH_MUTEX),
>  	MEDIA_IOC(SETUP_LINK, media_device_setup_link, MEDIA_IOC_FL_GRAPH_MUTEX),
>  	MEDIA_IOC(G_TOPOLOGY, media_device_get_topology, MEDIA_IOC_FL_GRAPH_MUTEX),
> +	MEDIA_IOC(REQUEST_ALLOC, media_device_request_alloc, 0),
>  };
>  
>  static long media_device_ioctl(struct file *filp, unsigned int cmd,
> @@ -686,6 +697,8 @@ void media_device_init(struct media_device *mdev)
>  	INIT_LIST_HEAD(&mdev->pads);
>  	INIT_LIST_HEAD(&mdev->links);
>  	INIT_LIST_HEAD(&mdev->entity_notify);
> +
> +	mutex_init(&mdev->req_queue_mutex);
>  	mutex_init(&mdev->graph_mutex);
>  	ida_init(&mdev->entity_internal_idx);
>  
> diff --git a/drivers/media/media-request.c b/drivers/media/media-request.c
> new file mode 100644
> index 000000000000..22881d5700c8
> --- /dev/null
> +++ b/drivers/media/media-request.c
> @@ -0,0 +1,418 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Media device request objects
> + *
> + * Copyright (C) 2018 Intel Corporation
> + * Copyright (C) 2018 Google, Inc.
> + *
> + * Author: Sakari Ailus <sakari.ailus@linux.intel.com>
> + */
> +
> +#include <linux/anon_inodes.h>
> +#include <linux/file.h>
> +
> +#include <media/media-device.h>
> +#include <media/media-request.h>
> +
> +static const char * const request_state[] = {
> +	[MEDIA_REQUEST_STATE_IDLE]	 = "idle",
> +	[MEDIA_REQUEST_STATE_VALIDATING] = "validating",
> +	[MEDIA_REQUEST_STATE_QUEUED]	 = "queued",
> +	[MEDIA_REQUEST_STATE_COMPLETE]	 = "complete",
> +	[MEDIA_REQUEST_STATE_CLEANING]	 = "cleaning",
> +};
> +
> +static const char *
> +media_request_state_str(enum media_request_state state)
> +{
> +	if (WARN_ON(state >= ARRAY_SIZE(request_state)))
> +		return "unknown";
> +	return request_state[state];
> +}
> +
> +static void media_request_clean(struct media_request *req)
> +{
> +	struct media_request_object *obj, *obj_safe;
> +
> +	WARN_ON(atomic_read(&req->state) != MEDIA_REQUEST_STATE_CLEANING);
> +
> +	list_for_each_entry_safe(obj, obj_safe, &req->objects, list) {
> +		media_request_object_unbind(obj);
> +		media_request_object_put(obj);
> +	}
> +
> +	req->num_incomplete_objects = 0;
> +	wake_up_interruptible_all(&req->poll_wait);
> +}
> +
> +static void media_request_release(struct kref *kref)
> +{
> +	struct media_request *req =
> +		container_of(kref, struct media_request, kref);
> +	struct media_device *mdev = req->mdev;
> +
> +	dev_dbg(mdev->dev, "request: release %s\n", req->debug_str);
> +
> +	atomic_set(&req->state, MEDIA_REQUEST_STATE_CLEANING);
> +
> +	media_request_clean(req);
> +
> +	if (mdev->ops->req_free)
> +		mdev->ops->req_free(req);
> +	else
> +		kfree(req);
> +}
> +
> +void media_request_put(struct media_request *req)
> +{
> +	kref_put(&req->kref, media_request_release);
> +}
> +EXPORT_SYMBOL_GPL(media_request_put);
> +
> +void media_request_cancel(struct media_request *req)
> +{
> +	struct media_request_object *obj, *obj_safe;
> +
> +	/*
> +	 * This is serialized with the req_queue_mutex and streaming
> +	 * has stopped, so there is no need to take the spinlock here.
> +	 */
> +	WARN_ON_ONCE(!mutex_is_locked(&req->mdev->req_queue_mutex));
> +	if (atomic_read(&req->state) != MEDIA_REQUEST_STATE_QUEUED)
> +		return;
> +
> +	list_for_each_entry_safe(obj, obj_safe, &req->objects, list)
> +		if (obj->ops->cancel)
> +			obj->ops->cancel(obj);
> +}
> +EXPORT_SYMBOL_GPL(media_request_cancel);

Forget about this function, while trying to document this function I realized
that this is the wrong approach. This should be done through a vb2 op instead
that drivers have to implement.

It's fixed in the upcoming v13.

Regards,

	Hans

Re: [RFCv12 PATCH 05/29] media-request: add media_request_find

[Sakari Ailus]

Hi Hans,

Thanks for the update.

On Tue, May 01, 2018 at 11:00:27AM +0200, Hans Verkuil wrote:
> From: Hans Verkuil <hans.verkuil@cisco.com>
> 
> Add media_request_find() to find a request based on the file
> descriptor.

What would you think of calling this media_request_get_by_fd() instead?

I think what the function does has changed over the time a bit but the name
has stayed.

> 
> The caller has to call media_request_put() for the returned
> request since this function increments the refcount.
> 
> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
> ---
>  drivers/media/media-request.c | 44 +++++++++++++++++++++++++++++++++++
>  include/media/media-request.h | 10 ++++++++
>  2 files changed, 54 insertions(+)
> 
> diff --git a/drivers/media/media-request.c b/drivers/media/media-request.c
> index 22881d5700c8..a186db290d51 100644
> --- a/drivers/media/media-request.c
> +++ b/drivers/media/media-request.c
> @@ -234,6 +234,50 @@ static const struct file_operations request_fops = {
>  	.release = media_request_close,
>  };
>  
> +/**
> + * media_request_find - Find a request based on the file descriptor
> + * @mdev: The media device
> + * @request_fd: The request file handle
> + *
> + * Find and return the request associated with the given file descriptor, or
> + * an error if no such request exists.
> + *
> + * When the function returns a request it increases its reference count. The
> + * caller is responsible for releasing the reference by calling
> + * media_request_put() on the request.
> + */
> +struct media_request *
> +media_request_find(struct media_device *mdev, int request_fd)
> +{
> +	struct file *filp;
> +	struct media_request *req;
> +
> +	if (!mdev || !mdev->ops ||
> +	    !mdev->ops->req_validate || !mdev->ops->req_queue)
> +		return ERR_PTR(-EPERM);
> +
> +	filp = fget(request_fd);
> +	if (!filp)
> +		return ERR_PTR(-ENOENT);
> +
> +	if (filp->f_op != &request_fops)
> +		goto err_fput;
> +	req = filp->private_data;
> +	if (req->mdev != mdev)
> +		goto err_fput;
> +
> +	media_request_get(req);
> +	fput(filp);
> +
> +	return req;
> +
> +err_fput:
> +	fput(filp);
> +
> +	return ERR_PTR(-ENOENT);
> +}
> +EXPORT_SYMBOL_GPL(media_request_find);
> +
>  int media_request_alloc(struct media_device *mdev,
>  			struct media_request_alloc *alloc)
>  {
> diff --git a/include/media/media-request.h b/include/media/media-request.h
> index 9051dfbc7d30..ce62fe74ebd6 100644
> --- a/include/media/media-request.h
> +++ b/include/media/media-request.h
> @@ -70,6 +70,9 @@ static inline void media_request_get(struct media_request *req)
>  void media_request_put(struct media_request *req);
>  void media_request_cancel(struct media_request *req);
>  
> +struct media_request *
> +media_request_find(struct media_device *mdev, int request_fd);
> +
>  int media_request_alloc(struct media_device *mdev,
>  			struct media_request_alloc *alloc);
>  #else
> @@ -85,6 +88,12 @@ static inline void media_request_cancel(struct media_request *req)
>  {
>  }
>  
> +static inline struct media_request *
> +media_request_find(struct media_device *mdev, int request_fd)
> +{
> +	return ERR_PTR(-ENOENT);
> +}
> +
>  #endif
>  
>  struct media_request_object_ops {
> @@ -188,6 +197,7 @@ static inline void media_request_object_unbind(struct media_request_object *obj)
>  static inline void media_request_object_complete(struct media_request_object *obj)
>  {
>  }
> +
>  #endif
>  
>  #endif
> -- 
> 2.17.0
> 

-- 
Sakari Ailus
e-mail: sakari.ailus@iki.fi

Re: [RFCv12 PATCH 03/29] media-request: implement media requests

[Sakari Ailus]

Hi Hans,

On Tue, May 01, 2018 at 11:00:25AM +0200, Hans Verkuil wrote:
> From: Hans Verkuil <hans.verkuil@cisco.com>
> 
> Add initial media request support.
> 
> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
> ---
>  drivers/media/Makefile        |   3 +-
>  drivers/media/media-device.c  |  13 ++
>  drivers/media/media-request.c | 418 ++++++++++++++++++++++++++++++++++
>  include/media/media-device.h  |  17 ++
>  include/media/media-request.h | 193 ++++++++++++++++
>  5 files changed, 643 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/media/media-request.c
>  create mode 100644 include/media/media-request.h
> 
> diff --git a/drivers/media/Makefile b/drivers/media/Makefile
> index 594b462ddf0e..985d35ec6b29 100644
> --- a/drivers/media/Makefile
> +++ b/drivers/media/Makefile
> @@ -3,7 +3,8 @@
>  # Makefile for the kernel multimedia device drivers.
>  #
>  
> -media-objs	:= media-device.o media-devnode.o media-entity.o
> +media-objs	:= media-device.o media-devnode.o media-entity.o \
> +		   media-request.o
>  
>  #
>  # I2C drivers should come before other drivers, otherwise they'll fail
> diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
> index 35e81f7c0d2f..25d7e2a3ee84 100644
> --- a/drivers/media/media-device.c
> +++ b/drivers/media/media-device.c
> @@ -32,6 +32,7 @@
>  #include <media/media-device.h>
>  #include <media/media-devnode.h>
>  #include <media/media-entity.h>
> +#include <media/media-request.h>
>  
>  #ifdef CONFIG_MEDIA_CONTROLLER
>  
> @@ -366,6 +367,15 @@ static long media_device_get_topology(struct media_device *mdev,
>  	return ret;
>  }
>  
> +static long media_device_request_alloc(struct media_device *mdev,
> +				       struct media_request_alloc *alloc)
> +{
> +	if (!mdev->ops || !mdev->ops->req_validate || !mdev->ops->req_queue)
> +		return -ENOTTY;
> +
> +	return media_request_alloc(mdev, alloc);
> +}
> +
>  static long copy_arg_from_user(void *karg, void __user *uarg, unsigned int cmd)
>  {
>  	/* All media IOCTLs are _IOWR() */
> @@ -414,6 +424,7 @@ static const struct media_ioctl_info ioctl_info[] = {
>  	MEDIA_IOC(ENUM_LINKS, media_device_enum_links, MEDIA_IOC_FL_GRAPH_MUTEX),
>  	MEDIA_IOC(SETUP_LINK, media_device_setup_link, MEDIA_IOC_FL_GRAPH_MUTEX),
>  	MEDIA_IOC(G_TOPOLOGY, media_device_get_topology, MEDIA_IOC_FL_GRAPH_MUTEX),
> +	MEDIA_IOC(REQUEST_ALLOC, media_device_request_alloc, 0),
>  };
>  
>  static long media_device_ioctl(struct file *filp, unsigned int cmd,
> @@ -686,6 +697,8 @@ void media_device_init(struct media_device *mdev)
>  	INIT_LIST_HEAD(&mdev->pads);
>  	INIT_LIST_HEAD(&mdev->links);
>  	INIT_LIST_HEAD(&mdev->entity_notify);
> +
> +	mutex_init(&mdev->req_queue_mutex);

You'll need to add the corresponding mutex_destroy() to
media_device_cleanup().

>  	mutex_init(&mdev->graph_mutex);
>  	ida_init(&mdev->entity_internal_idx);
>  
> diff --git a/drivers/media/media-request.c b/drivers/media/media-request.c
> new file mode 100644
> index 000000000000..22881d5700c8
> --- /dev/null
> +++ b/drivers/media/media-request.c
> @@ -0,0 +1,418 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Media device request objects
> + *
> + * Copyright (C) 2018 Intel Corporation
> + * Copyright (C) 2018 Google, Inc.
> + *
> + * Author: Sakari Ailus <sakari.ailus@linux.intel.com>
> + */
> +
> +#include <linux/anon_inodes.h>
> +#include <linux/file.h>
> +
> +#include <media/media-device.h>
> +#include <media/media-request.h>
> +
> +static const char * const request_state[] = {
> +	[MEDIA_REQUEST_STATE_IDLE]	 = "idle",
> +	[MEDIA_REQUEST_STATE_VALIDATING] = "validating",
> +	[MEDIA_REQUEST_STATE_QUEUED]	 = "queued",
> +	[MEDIA_REQUEST_STATE_COMPLETE]	 = "complete",
> +	[MEDIA_REQUEST_STATE_CLEANING]	 = "cleaning",
> +};
> +
> +static const char *
> +media_request_state_str(enum media_request_state state)
> +{
> +	if (WARN_ON(state >= ARRAY_SIZE(request_state)))
> +		return "unknown";

Unknown or invalid? I'd think that states that are not defined in
request_state above are not valid.

> +	return request_state[state];
> +}
> +
> +static void media_request_clean(struct media_request *req)
> +{
> +	struct media_request_object *obj, *obj_safe;
> +
> +	WARN_ON(atomic_read(&req->state) != MEDIA_REQUEST_STATE_CLEANING);
> +
> +	list_for_each_entry_safe(obj, obj_safe, &req->objects, list) {
> +		media_request_object_unbind(obj);
> +		media_request_object_put(obj);
> +	}
> +
> +	req->num_incomplete_objects = 0;
> +	wake_up_interruptible_all(&req->poll_wait);
> +}
> +
> +static void media_request_release(struct kref *kref)
> +{
> +	struct media_request *req =
> +		container_of(kref, struct media_request, kref);
> +	struct media_device *mdev = req->mdev;
> +
> +	dev_dbg(mdev->dev, "request: release %s\n", req->debug_str);
> +
> +	atomic_set(&req->state, MEDIA_REQUEST_STATE_CLEANING);
> +
> +	media_request_clean(req);
> +
> +	if (mdev->ops->req_free)
> +		mdev->ops->req_free(req);
> +	else
> +		kfree(req);
> +}
> +
> +void media_request_put(struct media_request *req)
> +{
> +	kref_put(&req->kref, media_request_release);
> +}
> +EXPORT_SYMBOL_GPL(media_request_put);
> +
> +void media_request_cancel(struct media_request *req)
> +{
> +	struct media_request_object *obj, *obj_safe;
> +
> +	/*
> +	 * This is serialized with the req_queue_mutex and streaming
> +	 * has stopped, so there is no need to take the spinlock here.
> +	 */
> +	WARN_ON_ONCE(!mutex_is_locked(&req->mdev->req_queue_mutex));

Hmm. How about lockdep_assert_held(&req->mdev->req_queue_mutex)?

> +	if (atomic_read(&req->state) != MEDIA_REQUEST_STATE_QUEUED)
> +		return;
> +
> +	list_for_each_entry_safe(obj, obj_safe, &req->objects, list)
> +		if (obj->ops->cancel)
> +			obj->ops->cancel(obj);
> +}
> +EXPORT_SYMBOL_GPL(media_request_cancel);
> +
> +static int media_request_close(struct inode *inode, struct file *filp)
> +{
> +	struct media_request *req = filp->private_data;
> +
> +	media_request_put(req);

A newline would be nice here.

> +	return 0;
> +}
> +
> +static unsigned int media_request_poll(struct file *filp,
> +				       struct poll_table_struct *wait)
> +{
> +	struct media_request *req = filp->private_data;
> +	unsigned long flags;
> +	unsigned int ret = 0;
> +	enum media_request_state state;
> +
> +	if (!(poll_requested_events(wait) & POLLPRI))
> +		return 0;
> +
> +	spin_lock_irqsave(&req->lock, flags);
> +	state = atomic_read(&req->state);
> +
> +	if (state == MEDIA_REQUEST_STATE_COMPLETE) {
> +		ret = POLLPRI;
> +		goto unlock;
> +	}
> +	if (state == MEDIA_REQUEST_STATE_IDLE) {

Should this be just anything else than QUEUE or VALIDATING? You're missing
CLEANING here, for instance.

> +		ret = POLLERR;
> +		goto unlock;
> +	}
> +
> +	poll_wait(filp, &req->poll_wait, wait);

Newline?

> +unlock:
> +	spin_unlock_irqrestore(&req->lock, flags);
> +	return ret;
> +}
> +
> +static long media_request_ioctl_queue(struct media_request *req)
> +{
> +	struct media_device *mdev = req->mdev;
> +	enum media_request_state state;
> +	unsigned long flags;
> +	int ret = 0;
> +
> +	dev_dbg(mdev->dev, "request: queue %s\n", req->debug_str);
> +
> +	/*
> +	 * Ensure the request that is validated will be the one that gets queued
> +	 * next by serialising the queueing process. This mutex is also used
> +	 * to serialize with canceling a vb2 queue and with setting values such
> +	 * as controls in a request.
> +	 */
> +	mutex_lock(&mdev->req_queue_mutex);
> +
> +	spin_lock_irqsave(&req->lock, flags);
> +	state = atomic_cmpxchg(&req->state, MEDIA_REQUEST_STATE_IDLE,
> +			       MEDIA_REQUEST_STATE_VALIDATING);
> +	spin_unlock_irqrestore(&req->lock, flags);
> +	if (state != MEDIA_REQUEST_STATE_IDLE) {
> +		dev_dbg(mdev->dev,
> +			"request: unable to queue %s, request in state %s\n",
> +			req->debug_str, media_request_state_str(state));
> +		mutex_unlock(&mdev->req_queue_mutex);
> +		return -EBUSY;
> +	}
> +
> +	ret = mdev->ops->req_validate(req);
> +
> +	/*
> +	 * If the req_validate was successful, then we mark the state as QUEUED
> +	 * and call req_queue. The reason we set the state first is that this
> +	 * allows req_queue to unbind or complete the queued objects in case
> +	 * they are immediately 'consumed'. State changes from QUEUED to another
> +	 * state can only happen if either the driver changes the state or if
> +	 * the user cancels the vb2 queue. The driver can only change the state
> +	 * after each object is queued through the req_queue op (and note that
> +	 * that op cannot fail), so setting the state to QUEUED up front is
> +	 * safe.
> +	 *
> +	 * The other reason for changing the state is if the vb2 queue is
> +	 * canceled, and that uses the req_queue_mutex which is still locked
> +	 * while req_queue is called, so that's safe as well.
> +	 */
> +	atomic_set(&req->state,
> +		   ret ? MEDIA_REQUEST_STATE_IDLE : MEDIA_REQUEST_STATE_QUEUED);
> +
> +	if (!ret)
> +		mdev->ops->req_queue(req);
> +
> +	mutex_unlock(&mdev->req_queue_mutex);
> +
> +	if (ret) {
> +		dev_dbg(mdev->dev, "request: can't queue %s (%d)\n",
> +			req->debug_str, ret);
> +	} else {
> +		media_request_get(req);

You'll need to get a reference before you queue the request. Otherwise it's
possible that it completes before you get here, and you end up accessing
released memory. The request refcount might be also under 0 before that
though.

> +	}
> +
> +	return ret;
> +}
> +
> +static long media_request_ioctl_reinit(struct media_request *req)
> +{
> +	struct media_device *mdev = req->mdev;
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&req->lock, flags);
> +	if (atomic_read(&req->state) != MEDIA_REQUEST_STATE_IDLE &&
> +	    atomic_read(&req->state) != MEDIA_REQUEST_STATE_COMPLETE) {
> +		dev_dbg(mdev->dev,
> +			"request: %s not in idle or complete state, cannot reinit\n",
> +			req->debug_str);
> +		spin_unlock_irqrestore(&req->lock, flags);
> +		return -EBUSY;
> +	}
> +	atomic_set(&req->state, MEDIA_REQUEST_STATE_CLEANING);
> +	spin_unlock_irqrestore(&req->lock, flags);
> +
> +	media_request_clean(req);
> +
> +	atomic_set(&req->state, MEDIA_REQUEST_STATE_IDLE);
> +
> +	return 0;
> +}
> +
> +static long media_request_ioctl(struct file *filp, unsigned int cmd,
> +				unsigned long arg)
> +{
> +	struct media_request *req = filp->private_data;
> +
> +	switch (cmd) {
> +	case MEDIA_REQUEST_IOC_QUEUE:
> +		return media_request_ioctl_queue(req);
> +	case MEDIA_REQUEST_IOC_REINIT:
> +		return media_request_ioctl_reinit(req);
> +	default:
> +		return -ENOIOCTLCMD;
> +	}
> +}
> +
> +static const struct file_operations request_fops = {
> +	.owner = THIS_MODULE,
> +	.poll = media_request_poll,
> +	.unlocked_ioctl = media_request_ioctl,
> +	.release = media_request_close,
> +};
> +
> +int media_request_alloc(struct media_device *mdev,
> +			struct media_request_alloc *alloc)
> +{
> +	struct media_request *req;
> +	struct file *filp;
> +	char comm[TASK_COMM_LEN];
> +	int fd;
> +	int ret;
> +
> +	/* Either both are NULL or both are non-NULL */
> +	if (WARN_ON(!mdev->ops->req_alloc ^ !mdev->ops->req_free))
> +		return -ENOMEM;
> +
> +	fd = get_unused_fd_flags(O_CLOEXEC);
> +	if (fd < 0)
> +		return fd;
> +
> +	filp = anon_inode_getfile("request", &request_fops, NULL, O_CLOEXEC);
> +	if (IS_ERR(filp)) {
> +		ret = PTR_ERR(filp);
> +		goto err_put_fd;
> +	}
> +
> +	if (mdev->ops->req_alloc)
> +		req = mdev->ops->req_alloc(mdev);
> +	else
> +		req = kzalloc(sizeof(*req), GFP_KERNEL);
> +	if (!req) {
> +		ret = -ENOMEM;
> +		goto err_fput;
> +	}
> +
> +	filp->private_data = req;
> +	req->mdev = mdev;
> +	atomic_set(&req->state, MEDIA_REQUEST_STATE_IDLE);
> +	req->num_incomplete_objects = 0;
> +	kref_init(&req->kref);
> +	INIT_LIST_HEAD(&req->objects);
> +	spin_lock_init(&req->lock);
> +	init_waitqueue_head(&req->poll_wait);
> +
> +	alloc->fd = fd;
> +
> +	get_task_comm(comm, current);
> +	snprintf(req->debug_str, sizeof(req->debug_str), "%s:%d",
> +		 comm, fd);
> +	dev_dbg(mdev->dev, "request: allocated %s\n", req->debug_str);
> +
> +	fd_install(fd, filp);
> +
> +	return 0;
> +
> +err_fput:
> +	fput(filp);
> +
> +err_put_fd:
> +	put_unused_fd(fd);
> +
> +	return ret;
> +}
> +
> +static void media_request_object_release(struct kref *kref)
> +{
> +	struct media_request_object *obj =
> +		container_of(kref, struct media_request_object, kref);
> +	struct media_request *req = obj->req;
> +
> +	if (req)
> +		media_request_object_unbind(obj);
> +	obj->ops->release(obj);
> +}
> +
> +void media_request_object_put(struct media_request_object *obj)
> +{
> +	kref_put(&obj->kref, media_request_object_release);
> +}
> +EXPORT_SYMBOL_GPL(media_request_object_put);
> +
> +void media_request_object_init(struct media_request_object *obj)
> +{
> +	obj->ops = NULL;
> +	obj->req = NULL;
> +	obj->priv = NULL;
> +	obj->completed = false;
> +	INIT_LIST_HEAD(&obj->list);
> +	kref_init(&obj->kref);
> +}
> +EXPORT_SYMBOL_GPL(media_request_object_init);
> +
> +int media_request_object_bind(struct media_request *req,
> +			      const struct media_request_object_ops *ops,
> +			      void *priv,
> +			      struct media_request_object *obj)
> +{
> +	unsigned long flags;
> +	int ret = -EBUSY;
> +
> +	if (WARN_ON(!ops->release || !ops->cancel))
> +		return -EPERM;
> +
> +	obj->req = req;
> +	obj->ops = ops;
> +	obj->priv = priv;

I think this function would benefit from some sprinkling of newlines here
and there. :-)

> +	spin_lock_irqsave(&req->lock, flags);
> +	if (WARN_ON(atomic_read(&req->state) != MEDIA_REQUEST_STATE_IDLE))
> +		goto unlock;
> +	list_add_tail(&obj->list, &req->objects);
> +	req->num_incomplete_objects++;
> +	ret = 0;
> +unlock:
> +	spin_unlock_irqrestore(&req->lock, flags);
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(media_request_object_bind);
> +
> +void media_request_object_unbind(struct media_request_object *obj)
> +{
> +	struct media_request *req = obj->req;
> +	enum media_request_state state;
> +	unsigned long flags;
> +	bool completed = false;
> +
> +	if (WARN_ON(!req))
> +		return;
> +
> +	spin_lock_irqsave(&req->lock, flags);
> +	list_del(&obj->list);
> +	obj->req = NULL;
> +
> +	state = atomic_read(&req->state);
> +
> +	if (state == MEDIA_REQUEST_STATE_COMPLETE ||
> +	    state == MEDIA_REQUEST_STATE_CLEANING)
> +		goto unlock;
> +
> +	if (WARN_ON(state == MEDIA_REQUEST_STATE_VALIDATING))
> +		goto unlock;
> +
> +	if (WARN_ON(!req->num_incomplete_objects))
> +		goto unlock;
> +
> +	req->num_incomplete_objects--;
> +	if (state == MEDIA_REQUEST_STATE_QUEUED &&
> +	    !req->num_incomplete_objects) {
> +		atomic_set(&req->state, MEDIA_REQUEST_STATE_COMPLETE);
> +		completed = true;
> +		wake_up_interruptible_all(&req->poll_wait);
> +	}

A newline before a label would be nice.

> +unlock:
> +	spin_unlock_irqrestore(&req->lock, flags);
> +	if (obj->ops->unbind)
> +		obj->ops->unbind(obj);
> +	if (completed)
> +		media_request_put(req);
> +}
> +EXPORT_SYMBOL_GPL(media_request_object_unbind);
> +
> +void media_request_object_complete(struct media_request_object *obj)
> +{
> +	struct media_request *req = obj->req;
> +	unsigned long flags;
> +	bool completed = false;
> +
> +	spin_lock_irqsave(&req->lock, flags);
> +	if (obj->completed)
> +		goto unlock;
> +	obj->completed = true;
> +	if (WARN_ON(!req->num_incomplete_objects) ||
> +	    WARN_ON(atomic_read(&req->state) != MEDIA_REQUEST_STATE_QUEUED))
> +		goto unlock;
> +
> +	if (!--req->num_incomplete_objects) {
> +		atomic_set(&req->state, MEDIA_REQUEST_STATE_COMPLETE);
> +		wake_up_interruptible_all(&req->poll_wait);
> +		completed = true;
> +	}
> +unlock:
> +	spin_unlock_irqrestore(&req->lock, flags);
> +	if (completed)
> +		media_request_put(req);
> +}
> +EXPORT_SYMBOL_GPL(media_request_object_complete);
> diff --git a/include/media/media-device.h b/include/media/media-device.h
> index bcc6ec434f1f..ae846208be51 100644
> --- a/include/media/media-device.h
> +++ b/include/media/media-device.h
> @@ -27,6 +27,7 @@
>  
>  struct ida;
>  struct device;
> +struct media_device;
>  
>  /**
>   * struct media_entity_notify - Media Entity Notify
> @@ -50,10 +51,22 @@ struct media_entity_notify {
>   * struct media_device_ops - Media device operations
>   * @link_notify: Link state change notification callback. This callback is
>   *		 called with the graph_mutex held.
> + * @req_alloc: Allocate a request
> + * @req_free: Free a request
> + * @req_validate: Validate a request, but do not queue yet
> + * @req_queue: Queue a validated request, cannot fail. If something goes
> + *	       wrong when queueing this request then it should be marked
> + *	       as such internally in the driver and any related buffers
> + *	       will eventually return to userspace with V4L2_BUF_FLAG_ERROR
> + *	       set.

Note that this is MC; I think the reference is fine but I'd make it
explicit this is V4L2, and possibly that it's an example.

>   */
>  struct media_device_ops {
>  	int (*link_notify)(struct media_link *link, u32 flags,
>  			   unsigned int notification);
> +	struct media_request *(*req_alloc)(struct media_device *mdev);
> +	void (*req_free)(struct media_request *req);
> +	int (*req_validate)(struct media_request *req);
> +	void (*req_queue)(struct media_request *req);
>  };
>  
>  /**
> @@ -88,6 +101,8 @@ struct media_device_ops {
>   * @disable_source: Disable Source Handler function pointer
>   *
>   * @ops:	Operation handler callbacks
> + * @req_queue_mutex: Serialise the MEDIA_REQUEST_IOC_QUEUE ioctl w.r.t. this
> + *		     media device.
>   *
>   * This structure represents an abstract high-level media device. It allows easy
>   * access to entities and provides basic media device-level support. The
> @@ -158,6 +173,8 @@ struct media_device {
>  	void (*disable_source)(struct media_entity *entity);
>  
>  	const struct media_device_ops *ops;
> +
> +	struct mutex req_queue_mutex;
>  };
>  
>  /* We don't need to include pci.h or usb.h here */
> diff --git a/include/media/media-request.h b/include/media/media-request.h
> new file mode 100644
> index 000000000000..9051dfbc7d30
> --- /dev/null
> +++ b/include/media/media-request.h
> @@ -0,0 +1,193 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Media device request objects
> + *
> + * Copyright (C) 2018 Intel Corporation
> + *
> + * Author: Sakari Ailus <sakari.ailus@linux.intel.com>
> + */
> +
> +#ifndef MEDIA_REQUEST_H
> +#define MEDIA_REQUEST_H
> +
> +#include <linux/list.h>
> +#include <linux/slab.h>
> +#include <linux/spinlock.h>
> +#include <linux/atomic.h>
> +
> +#include <media/media-device.h>
> +
> +/**
> + * enum media_request_state - media request state
> + *
> + * @MEDIA_REQUEST_STATE_IDLE:		Idle
> + * @MEDIA_REQUEST_STATE_VALIDATING:	Validating the request, no state changes
> + *					allowed
> + * @MEDIA_REQUEST_STATE_QUEUED:		Queued
> + * @MEDIA_REQUEST_STATE_COMPLETE:	Completed, the request is done
> + * @MEDIA_REQUEST_STATE_CLEANING:	Cleaning, the request is being re-inited
> + */
> +enum media_request_state {
> +	MEDIA_REQUEST_STATE_IDLE,
> +	MEDIA_REQUEST_STATE_VALIDATING,
> +	MEDIA_REQUEST_STATE_QUEUED,
> +	MEDIA_REQUEST_STATE_COMPLETE,
> +	MEDIA_REQUEST_STATE_CLEANING,
> +};
> +
> +struct media_request_object;
> +
> +/**
> + * struct media_request - Media device request
> + * @mdev: Media device this request belongs to
> + * @kref: Reference count
> + * @debug_str: Prefix for debug messages (process name:fd)
> + * @state: The state of the request
> + * @objects: List of @struct media_request_object request objects
> + * @num_objects: The number of objects in the request
> + * @num_incompleted_objects: The number of incomplete objects in the request
> + * @poll_wait: Wait queue for poll
> + * @lock: Serializes access to this struct
> + */
> +struct media_request {
> +	struct media_device *mdev;
> +	struct kref kref;
> +	char debug_str[TASK_COMM_LEN + 11];
> +	atomic_t state;
> +	struct list_head objects;
> +	unsigned int num_incomplete_objects;
> +	struct wait_queue_head poll_wait;
> +	spinlock_t lock;
> +};
> +
> +#ifdef CONFIG_MEDIA_CONTROLLER
> +
> +static inline void media_request_get(struct media_request *req)
> +{
> +	kref_get(&req->kref);
> +}
> +
> +void media_request_put(struct media_request *req);
> +void media_request_cancel(struct media_request *req);
> +
> +int media_request_alloc(struct media_device *mdev,
> +			struct media_request_alloc *alloc);
> +#else
> +static inline void media_request_get(struct media_request *req)
> +{
> +}
> +
> +static inline void media_request_put(struct media_request *req)
> +{
> +}
> +
> +static inline void media_request_cancel(struct media_request *req)
> +{
> +}
> +
> +#endif
> +
> +struct media_request_object_ops {
> +	int (*prepare)(struct media_request_object *object);
> +	void (*unprepare)(struct media_request_object *object);
> +	void (*queue)(struct media_request_object *object);
> +	void (*unbind)(struct media_request_object *object);
> +	void (*cancel)(struct media_request_object *object);
> +	void (*release)(struct media_request_object *object);
> +};
> +
> +/**
> + * struct media_request_object - An opaque object that belongs to a media
> + *				 request
> + *
> + * @ops: object's operations
> + * @priv: object's priv pointer
> + * @req: the request this object belongs to (can be NULL)
> + * @list: List entry of the object for @struct media_request
> + * @kref: Reference count of the object, acquire before releasing req->lock
> + * @completed: If true, then this object was completed.
> + *
> + * An object related to the request. This struct is embedded in the
> + * larger object data.
> + */
> +struct media_request_object {
> +	const struct media_request_object_ops *ops;
> +	void *priv;
> +	struct media_request *req;
> +	struct list_head list;
> +	struct kref kref;
> +	bool completed;
> +};
> +
> +#ifdef CONFIG_MEDIA_CONTROLLER
> +static inline void media_request_object_get(struct media_request_object *obj)
> +{
> +	kref_get(&obj->kref);
> +}
> +
> +/**
> + * media_request_object_put - Put a media request object
> + *
> + * @obj: The object
> + *
> + * Put a media request object. Once all references are gone, the
> + * object's memory is released.
> + */
> +void media_request_object_put(struct media_request_object *obj);
> +
> +/**
> + * media_request_object_init - Initialise a media request object
> + *
> + * Initialise a media request object. The object will be released using the
> + * release callback of the ops once it has no references (this function
> + * initialises references to one).
> + */
> +void media_request_object_init(struct media_request_object *obj);
> +
> +/**
> + * media_request_object_bind - Bind a media request object to a request
> + */
> +int media_request_object_bind(struct media_request *req,
> +			      const struct media_request_object_ops *ops,
> +			      void *priv,
> +			      struct media_request_object *obj);
> +
> +void media_request_object_unbind(struct media_request_object *obj);
> +
> +/**
> + * media_request_object_complete - Mark the media request object as complete
> + */
> +void media_request_object_complete(struct media_request_object *obj);
> +#else
> +static inline void media_request_object_get(struct media_request_object *obj)
> +{
> +}
> +
> +static inline void media_request_object_put(struct media_request_object *obj)
> +{
> +}
> +
> +static inline void media_request_object_init(struct media_request_object *obj)
> +{
> +	obj->ops = NULL;
> +	obj->req = NULL;
> +}
> +
> +static inline int media_request_object_bind(struct media_request *req,
> +			       const struct media_request_object_ops *ops,
> +			       void *priv,
> +			       struct media_request_object *obj)
> +{
> +	return 0;
> +}
> +
> +static inline void media_request_object_unbind(struct media_request_object *obj)
> +{
> +}
> +
> +static inline void media_request_object_complete(struct media_request_object *obj)
> +{
> +}
> +#endif
> +
> +#endif
> 

-- 
Kind regards,

Sakari Ailus
e-mail: sakari.ailus@iki.fi

Re: [RFCv12 PATCH 03/29] media-request: implement media requests

[Hans Verkuil]

On 03/05/18 00:24, Sakari Ailus wrote:
> Hi Hans,
> 
> On Tue, May 01, 2018 at 11:00:25AM +0200, Hans Verkuil wrote:
>> From: Hans Verkuil <hans.verkuil@cisco.com>
>>
>> Add initial media request support.
>>
>> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
>> ---
>>  drivers/media/Makefile        |   3 +-
>>  drivers/media/media-device.c  |  13 ++
>>  drivers/media/media-request.c | 418 ++++++++++++++++++++++++++++++++++
>>  include/media/media-device.h  |  17 ++
>>  include/media/media-request.h | 193 ++++++++++++++++
>>  5 files changed, 643 insertions(+), 1 deletion(-)
>>  create mode 100644 drivers/media/media-request.c
>>  create mode 100644 include/media/media-request.h
>>
>> diff --git a/drivers/media/Makefile b/drivers/media/Makefile
>> index 594b462ddf0e..985d35ec6b29 100644
>> --- a/drivers/media/Makefile
>> +++ b/drivers/media/Makefile
>> @@ -3,7 +3,8 @@
>>  # Makefile for the kernel multimedia device drivers.
>>  #
>>  
>> -media-objs	:= media-device.o media-devnode.o media-entity.o
>> +media-objs	:= media-device.o media-devnode.o media-entity.o \
>> +		   media-request.o
>>  
>>  #
>>  # I2C drivers should come before other drivers, otherwise they'll fail
>> diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
>> index 35e81f7c0d2f..25d7e2a3ee84 100644
>> --- a/drivers/media/media-device.c
>> +++ b/drivers/media/media-device.c
>> @@ -32,6 +32,7 @@
>>  #include <media/media-device.h>
>>  #include <media/media-devnode.h>
>>  #include <media/media-entity.h>
>> +#include <media/media-request.h>
>>  
>>  #ifdef CONFIG_MEDIA_CONTROLLER
>>  
>> @@ -366,6 +367,15 @@ static long media_device_get_topology(struct media_device *mdev,
>>  	return ret;
>>  }
>>  
>> +static long media_device_request_alloc(struct media_device *mdev,
>> +				       struct media_request_alloc *alloc)
>> +{
>> +	if (!mdev->ops || !mdev->ops->req_validate || !mdev->ops->req_queue)
>> +		return -ENOTTY;
>> +
>> +	return media_request_alloc(mdev, alloc);
>> +}
>> +
>>  static long copy_arg_from_user(void *karg, void __user *uarg, unsigned int cmd)
>>  {
>>  	/* All media IOCTLs are _IOWR() */
>> @@ -414,6 +424,7 @@ static const struct media_ioctl_info ioctl_info[] = {
>>  	MEDIA_IOC(ENUM_LINKS, media_device_enum_links, MEDIA_IOC_FL_GRAPH_MUTEX),
>>  	MEDIA_IOC(SETUP_LINK, media_device_setup_link, MEDIA_IOC_FL_GRAPH_MUTEX),
>>  	MEDIA_IOC(G_TOPOLOGY, media_device_get_topology, MEDIA_IOC_FL_GRAPH_MUTEX),
>> +	MEDIA_IOC(REQUEST_ALLOC, media_device_request_alloc, 0),
>>  };
>>  
>>  static long media_device_ioctl(struct file *filp, unsigned int cmd,
>> @@ -686,6 +697,8 @@ void media_device_init(struct media_device *mdev)
>>  	INIT_LIST_HEAD(&mdev->pads);
>>  	INIT_LIST_HEAD(&mdev->links);
>>  	INIT_LIST_HEAD(&mdev->entity_notify);
>> +
>> +	mutex_init(&mdev->req_queue_mutex);
> 
> You'll need to add the corresponding mutex_destroy() to
> media_device_cleanup().

Done.

> 
>>  	mutex_init(&mdev->graph_mutex);
>>  	ida_init(&mdev->entity_internal_idx);
>>  
>> diff --git a/drivers/media/media-request.c b/drivers/media/media-request.c
>> new file mode 100644
>> index 000000000000..22881d5700c8
>> --- /dev/null
>> +++ b/drivers/media/media-request.c
>> @@ -0,0 +1,418 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Media device request objects
>> + *
>> + * Copyright (C) 2018 Intel Corporation
>> + * Copyright (C) 2018 Google, Inc.
>> + *
>> + * Author: Sakari Ailus <sakari.ailus@linux.intel.com>
>> + */
>> +
>> +#include <linux/anon_inodes.h>
>> +#include <linux/file.h>
>> +
>> +#include <media/media-device.h>
>> +#include <media/media-request.h>
>> +
>> +static const char * const request_state[] = {
>> +	[MEDIA_REQUEST_STATE_IDLE]	 = "idle",
>> +	[MEDIA_REQUEST_STATE_VALIDATING] = "validating",
>> +	[MEDIA_REQUEST_STATE_QUEUED]	 = "queued",
>> +	[MEDIA_REQUEST_STATE_COMPLETE]	 = "complete",
>> +	[MEDIA_REQUEST_STATE_CLEANING]	 = "cleaning",
>> +};
>> +
>> +static const char *
>> +media_request_state_str(enum media_request_state state)
>> +{
>> +	if (WARN_ON(state >= ARRAY_SIZE(request_state)))
>> +		return "unknown";
> 
> Unknown or invalid? I'd think that states that are not defined in
> request_state above are not valid.

Changed to invalid.

> 
>> +	return request_state[state];
>> +}
>> +
>> +static void media_request_clean(struct media_request *req)
>> +{
>> +	struct media_request_object *obj, *obj_safe;
>> +
>> +	WARN_ON(atomic_read(&req->state) != MEDIA_REQUEST_STATE_CLEANING);
>> +
>> +	list_for_each_entry_safe(obj, obj_safe, &req->objects, list) {
>> +		media_request_object_unbind(obj);
>> +		media_request_object_put(obj);
>> +	}
>> +
>> +	req->num_incomplete_objects = 0;
>> +	wake_up_interruptible_all(&req->poll_wait);
>> +}
>> +
>> +static void media_request_release(struct kref *kref)
>> +{
>> +	struct media_request *req =
>> +		container_of(kref, struct media_request, kref);
>> +	struct media_device *mdev = req->mdev;
>> +
>> +	dev_dbg(mdev->dev, "request: release %s\n", req->debug_str);
>> +
>> +	atomic_set(&req->state, MEDIA_REQUEST_STATE_CLEANING);
>> +
>> +	media_request_clean(req);
>> +
>> +	if (mdev->ops->req_free)
>> +		mdev->ops->req_free(req);
>> +	else
>> +		kfree(req);
>> +}
>> +
>> +void media_request_put(struct media_request *req)
>> +{
>> +	kref_put(&req->kref, media_request_release);
>> +}
>> +EXPORT_SYMBOL_GPL(media_request_put);
>> +
>> +void media_request_cancel(struct media_request *req)
>> +{
>> +	struct media_request_object *obj, *obj_safe;
>> +
>> +	/*
>> +	 * This is serialized with the req_queue_mutex and streaming
>> +	 * has stopped, so there is no need to take the spinlock here.
>> +	 */
>> +	WARN_ON_ONCE(!mutex_is_locked(&req->mdev->req_queue_mutex));
> 
> Hmm. How about lockdep_assert_held(&req->mdev->req_queue_mutex)?
> 
>> +	if (atomic_read(&req->state) != MEDIA_REQUEST_STATE_QUEUED)
>> +		return;
>> +
>> +	list_for_each_entry_safe(obj, obj_safe, &req->objects, list)
>> +		if (obj->ops->cancel)
>> +			obj->ops->cancel(obj);
>> +}
>> +EXPORT_SYMBOL_GPL(media_request_cancel);

media_request_cancel is gone in v13, so this no longer applies.

>> +
>> +static int media_request_close(struct inode *inode, struct file *filp)
>> +{
>> +	struct media_request *req = filp->private_data;
>> +
>> +	media_request_put(req);
> 
> A newline would be nice here.

Why? I do not see it adding anything of value. Some of your other 'newline'
comments make it indeed more readable, but I don't see any benefit from it
here.

> 
>> +	return 0;
>> +}
>> +
>> +static unsigned int media_request_poll(struct file *filp,
>> +				       struct poll_table_struct *wait)
>> +{
>> +	struct media_request *req = filp->private_data;
>> +	unsigned long flags;
>> +	unsigned int ret = 0;
>> +	enum media_request_state state;
>> +
>> +	if (!(poll_requested_events(wait) & POLLPRI))
>> +		return 0;
>> +
>> +	spin_lock_irqsave(&req->lock, flags);
>> +	state = atomic_read(&req->state);
>> +
>> +	if (state == MEDIA_REQUEST_STATE_COMPLETE) {
>> +		ret = POLLPRI;
>> +		goto unlock;
>> +	}
>> +	if (state == MEDIA_REQUEST_STATE_IDLE) {
> 
> Should this be just anything else than QUEUE or VALIDATING? You're missing
> CLEANING here, for instance.

I changed it to != QUEUED. I don't think it is a good idea to include VALIDATING
in this. It only makes sense to poll for the result if the request is fully queued.

> 
>> +		ret = POLLERR;
>> +		goto unlock;
>> +	}
>> +
>> +	poll_wait(filp, &req->poll_wait, wait);
> 
> Newline?

Ack.

> 
>> +unlock:
>> +	spin_unlock_irqrestore(&req->lock, flags);
>> +	return ret;
>> +}
>> +
>> +static long media_request_ioctl_queue(struct media_request *req)
>> +{
>> +	struct media_device *mdev = req->mdev;
>> +	enum media_request_state state;
>> +	unsigned long flags;
>> +	int ret = 0;
>> +
>> +	dev_dbg(mdev->dev, "request: queue %s\n", req->debug_str);
>> +
>> +	/*
>> +	 * Ensure the request that is validated will be the one that gets queued
>> +	 * next by serialising the queueing process. This mutex is also used
>> +	 * to serialize with canceling a vb2 queue and with setting values such
>> +	 * as controls in a request.
>> +	 */
>> +	mutex_lock(&mdev->req_queue_mutex);
>> +
>> +	spin_lock_irqsave(&req->lock, flags);
>> +	state = atomic_cmpxchg(&req->state, MEDIA_REQUEST_STATE_IDLE,
>> +			       MEDIA_REQUEST_STATE_VALIDATING);
>> +	spin_unlock_irqrestore(&req->lock, flags);
>> +	if (state != MEDIA_REQUEST_STATE_IDLE) {
>> +		dev_dbg(mdev->dev,
>> +			"request: unable to queue %s, request in state %s\n",
>> +			req->debug_str, media_request_state_str(state));
>> +		mutex_unlock(&mdev->req_queue_mutex);
>> +		return -EBUSY;
>> +	}
>> +
>> +	ret = mdev->ops->req_validate(req);
>> +
>> +	/*
>> +	 * If the req_validate was successful, then we mark the state as QUEUED
>> +	 * and call req_queue. The reason we set the state first is that this
>> +	 * allows req_queue to unbind or complete the queued objects in case
>> +	 * they are immediately 'consumed'. State changes from QUEUED to another
>> +	 * state can only happen if either the driver changes the state or if
>> +	 * the user cancels the vb2 queue. The driver can only change the state
>> +	 * after each object is queued through the req_queue op (and note that
>> +	 * that op cannot fail), so setting the state to QUEUED up front is
>> +	 * safe.
>> +	 *
>> +	 * The other reason for changing the state is if the vb2 queue is
>> +	 * canceled, and that uses the req_queue_mutex which is still locked
>> +	 * while req_queue is called, so that's safe as well.
>> +	 */
>> +	atomic_set(&req->state,
>> +		   ret ? MEDIA_REQUEST_STATE_IDLE : MEDIA_REQUEST_STATE_QUEUED);
>> +
>> +	if (!ret)
>> +		mdev->ops->req_queue(req);
>> +
>> +	mutex_unlock(&mdev->req_queue_mutex);
>> +
>> +	if (ret) {
>> +		dev_dbg(mdev->dev, "request: can't queue %s (%d)\n",
>> +			req->debug_str, ret);
>> +	} else {
>> +		media_request_get(req);
> 
> You'll need to get a reference before you queue the request. Otherwise it's
> possible that it completes before you get here, and you end up accessing
> released memory. The request refcount might be also under 0 before that
> though.

No, that can't happen. This function implements the QUEUE ioctl, which can only
be called by userspace through the request fd, so there is always at least one
reference open.

> 
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static long media_request_ioctl_reinit(struct media_request *req)
>> +{
>> +	struct media_device *mdev = req->mdev;
>> +	unsigned long flags;
>> +
>> +	spin_lock_irqsave(&req->lock, flags);
>> +	if (atomic_read(&req->state) != MEDIA_REQUEST_STATE_IDLE &&
>> +	    atomic_read(&req->state) != MEDIA_REQUEST_STATE_COMPLETE) {
>> +		dev_dbg(mdev->dev,
>> +			"request: %s not in idle or complete state, cannot reinit\n",
>> +			req->debug_str);
>> +		spin_unlock_irqrestore(&req->lock, flags);
>> +		return -EBUSY;
>> +	}
>> +	atomic_set(&req->state, MEDIA_REQUEST_STATE_CLEANING);
>> +	spin_unlock_irqrestore(&req->lock, flags);
>> +
>> +	media_request_clean(req);
>> +
>> +	atomic_set(&req->state, MEDIA_REQUEST_STATE_IDLE);
>> +
>> +	return 0;
>> +}
>> +
>> +static long media_request_ioctl(struct file *filp, unsigned int cmd,
>> +				unsigned long arg)
>> +{
>> +	struct media_request *req = filp->private_data;
>> +
>> +	switch (cmd) {
>> +	case MEDIA_REQUEST_IOC_QUEUE:
>> +		return media_request_ioctl_queue(req);
>> +	case MEDIA_REQUEST_IOC_REINIT:
>> +		return media_request_ioctl_reinit(req);
>> +	default:
>> +		return -ENOIOCTLCMD;
>> +	}
>> +}
>> +
>> +static const struct file_operations request_fops = {
>> +	.owner = THIS_MODULE,
>> +	.poll = media_request_poll,
>> +	.unlocked_ioctl = media_request_ioctl,
>> +	.release = media_request_close,
>> +};
>> +
>> +int media_request_alloc(struct media_device *mdev,
>> +			struct media_request_alloc *alloc)
>> +{
>> +	struct media_request *req;
>> +	struct file *filp;
>> +	char comm[TASK_COMM_LEN];
>> +	int fd;
>> +	int ret;
>> +
>> +	/* Either both are NULL or both are non-NULL */
>> +	if (WARN_ON(!mdev->ops->req_alloc ^ !mdev->ops->req_free))
>> +		return -ENOMEM;
>> +
>> +	fd = get_unused_fd_flags(O_CLOEXEC);
>> +	if (fd < 0)
>> +		return fd;
>> +
>> +	filp = anon_inode_getfile("request", &request_fops, NULL, O_CLOEXEC);
>> +	if (IS_ERR(filp)) {
>> +		ret = PTR_ERR(filp);
>> +		goto err_put_fd;
>> +	}
>> +
>> +	if (mdev->ops->req_alloc)
>> +		req = mdev->ops->req_alloc(mdev);
>> +	else
>> +		req = kzalloc(sizeof(*req), GFP_KERNEL);
>> +	if (!req) {
>> +		ret = -ENOMEM;
>> +		goto err_fput;
>> +	}
>> +
>> +	filp->private_data = req;
>> +	req->mdev = mdev;
>> +	atomic_set(&req->state, MEDIA_REQUEST_STATE_IDLE);
>> +	req->num_incomplete_objects = 0;
>> +	kref_init(&req->kref);
>> +	INIT_LIST_HEAD(&req->objects);
>> +	spin_lock_init(&req->lock);
>> +	init_waitqueue_head(&req->poll_wait);
>> +
>> +	alloc->fd = fd;
>> +
>> +	get_task_comm(comm, current);
>> +	snprintf(req->debug_str, sizeof(req->debug_str), "%s:%d",
>> +		 comm, fd);
>> +	dev_dbg(mdev->dev, "request: allocated %s\n", req->debug_str);
>> +
>> +	fd_install(fd, filp);
>> +
>> +	return 0;
>> +
>> +err_fput:
>> +	fput(filp);
>> +
>> +err_put_fd:
>> +	put_unused_fd(fd);
>> +
>> +	return ret;
>> +}
>> +
>> +static void media_request_object_release(struct kref *kref)
>> +{
>> +	struct media_request_object *obj =
>> +		container_of(kref, struct media_request_object, kref);
>> +	struct media_request *req = obj->req;
>> +
>> +	if (req)
>> +		media_request_object_unbind(obj);
>> +	obj->ops->release(obj);
>> +}
>> +
>> +void media_request_object_put(struct media_request_object *obj)
>> +{
>> +	kref_put(&obj->kref, media_request_object_release);
>> +}
>> +EXPORT_SYMBOL_GPL(media_request_object_put);
>> +
>> +void media_request_object_init(struct media_request_object *obj)
>> +{
>> +	obj->ops = NULL;
>> +	obj->req = NULL;
>> +	obj->priv = NULL;
>> +	obj->completed = false;
>> +	INIT_LIST_HEAD(&obj->list);
>> +	kref_init(&obj->kref);
>> +}
>> +EXPORT_SYMBOL_GPL(media_request_object_init);
>> +
>> +int media_request_object_bind(struct media_request *req,
>> +			      const struct media_request_object_ops *ops,
>> +			      void *priv,
>> +			      struct media_request_object *obj)
>> +{
>> +	unsigned long flags;
>> +	int ret = -EBUSY;
>> +
>> +	if (WARN_ON(!ops->release || !ops->cancel))
>> +		return -EPERM;
>> +
>> +	obj->req = req;
>> +	obj->ops = ops;
>> +	obj->priv = priv;
> 
> I think this function would benefit from some sprinkling of newlines here
> and there. :-)

Done.

> 
>> +	spin_lock_irqsave(&req->lock, flags);
>> +	if (WARN_ON(atomic_read(&req->state) != MEDIA_REQUEST_STATE_IDLE))
>> +		goto unlock;
>> +	list_add_tail(&obj->list, &req->objects);
>> +	req->num_incomplete_objects++;
>> +	ret = 0;
>> +unlock:
>> +	spin_unlock_irqrestore(&req->lock, flags);
>> +	return ret;
>> +}
>> +EXPORT_SYMBOL_GPL(media_request_object_bind);
>> +
>> +void media_request_object_unbind(struct media_request_object *obj)
>> +{
>> +	struct media_request *req = obj->req;
>> +	enum media_request_state state;
>> +	unsigned long flags;
>> +	bool completed = false;
>> +
>> +	if (WARN_ON(!req))
>> +		return;
>> +
>> +	spin_lock_irqsave(&req->lock, flags);
>> +	list_del(&obj->list);
>> +	obj->req = NULL;
>> +
>> +	state = atomic_read(&req->state);
>> +
>> +	if (state == MEDIA_REQUEST_STATE_COMPLETE ||
>> +	    state == MEDIA_REQUEST_STATE_CLEANING)
>> +		goto unlock;
>> +
>> +	if (WARN_ON(state == MEDIA_REQUEST_STATE_VALIDATING))
>> +		goto unlock;
>> +
>> +	if (WARN_ON(!req->num_incomplete_objects))
>> +		goto unlock;
>> +
>> +	req->num_incomplete_objects--;
>> +	if (state == MEDIA_REQUEST_STATE_QUEUED &&
>> +	    !req->num_incomplete_objects) {
>> +		atomic_set(&req->state, MEDIA_REQUEST_STATE_COMPLETE);
>> +		completed = true;
>> +		wake_up_interruptible_all(&req->poll_wait);
>> +	}
> 
> A newline before a label would be nice.

Done.

> 
>> +unlock:
>> +	spin_unlock_irqrestore(&req->lock, flags);
>> +	if (obj->ops->unbind)
>> +		obj->ops->unbind(obj);
>> +	if (completed)
>> +		media_request_put(req);
>> +}
>> +EXPORT_SYMBOL_GPL(media_request_object_unbind);
>> +
>> +void media_request_object_complete(struct media_request_object *obj)
>> +{
>> +	struct media_request *req = obj->req;
>> +	unsigned long flags;
>> +	bool completed = false;
>> +
>> +	spin_lock_irqsave(&req->lock, flags);
>> +	if (obj->completed)
>> +		goto unlock;
>> +	obj->completed = true;
>> +	if (WARN_ON(!req->num_incomplete_objects) ||
>> +	    WARN_ON(atomic_read(&req->state) != MEDIA_REQUEST_STATE_QUEUED))
>> +		goto unlock;
>> +
>> +	if (!--req->num_incomplete_objects) {
>> +		atomic_set(&req->state, MEDIA_REQUEST_STATE_COMPLETE);
>> +		wake_up_interruptible_all(&req->poll_wait);
>> +		completed = true;
>> +	}
>> +unlock:
>> +	spin_unlock_irqrestore(&req->lock, flags);
>> +	if (completed)
>> +		media_request_put(req);
>> +}
>> +EXPORT_SYMBOL_GPL(media_request_object_complete);
>> diff --git a/include/media/media-device.h b/include/media/media-device.h
>> index bcc6ec434f1f..ae846208be51 100644
>> --- a/include/media/media-device.h
>> +++ b/include/media/media-device.h
>> @@ -27,6 +27,7 @@
>>  
>>  struct ida;
>>  struct device;
>> +struct media_device;
>>  
>>  /**
>>   * struct media_entity_notify - Media Entity Notify
>> @@ -50,10 +51,22 @@ struct media_entity_notify {
>>   * struct media_device_ops - Media device operations
>>   * @link_notify: Link state change notification callback. This callback is
>>   *		 called with the graph_mutex held.
>> + * @req_alloc: Allocate a request
>> + * @req_free: Free a request
>> + * @req_validate: Validate a request, but do not queue yet
>> + * @req_queue: Queue a validated request, cannot fail. If something goes
>> + *	       wrong when queueing this request then it should be marked
>> + *	       as such internally in the driver and any related buffers
>> + *	       will eventually return to userspace with V4L2_BUF_FLAG_ERROR
>> + *	       set.
> 
> Note that this is MC; I think the reference is fine but I'd make it
> explicit this is V4L2, and possibly that it's an example.

I've changed the last line to:

"must eventually return to vb2 with state VB2_BUF_STATE_ERROR."

Since this is really a vb2 thing, not V4L2.

It's not an example, based on what I know this should really be done like
this. If reality proves to be different, then the comment will need to change.

> 
>>   */
>>  struct media_device_ops {
>>  	int (*link_notify)(struct media_link *link, u32 flags,
>>  			   unsigned int notification);
>> +	struct media_request *(*req_alloc)(struct media_device *mdev);
>> +	void (*req_free)(struct media_request *req);
>> +	int (*req_validate)(struct media_request *req);
>> +	void (*req_queue)(struct media_request *req);
>>  };
>>  
>>  /**
>> @@ -88,6 +101,8 @@ struct media_device_ops {
>>   * @disable_source: Disable Source Handler function pointer
>>   *
>>   * @ops:	Operation handler callbacks
>> + * @req_queue_mutex: Serialise the MEDIA_REQUEST_IOC_QUEUE ioctl w.r.t. this
>> + *		     media device.
>>   *
>>   * This structure represents an abstract high-level media device. It allows easy
>>   * access to entities and provides basic media device-level support. The
>> @@ -158,6 +173,8 @@ struct media_device {
>>  	void (*disable_source)(struct media_entity *entity);
>>  
>>  	const struct media_device_ops *ops;
>> +
>> +	struct mutex req_queue_mutex;
>>  };
>>  
>>  /* We don't need to include pci.h or usb.h here */
>> diff --git a/include/media/media-request.h b/include/media/media-request.h
>> new file mode 100644
>> index 000000000000..9051dfbc7d30
>> --- /dev/null
>> +++ b/include/media/media-request.h
>> @@ -0,0 +1,193 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Media device request objects
>> + *
>> + * Copyright (C) 2018 Intel Corporation
>> + *
>> + * Author: Sakari Ailus <sakari.ailus@linux.intel.com>
>> + */
>> +
>> +#ifndef MEDIA_REQUEST_H
>> +#define MEDIA_REQUEST_H
>> +
>> +#include <linux/list.h>
>> +#include <linux/slab.h>
>> +#include <linux/spinlock.h>
>> +#include <linux/atomic.h>
>> +
>> +#include <media/media-device.h>
>> +
>> +/**
>> + * enum media_request_state - media request state
>> + *
>> + * @MEDIA_REQUEST_STATE_IDLE:		Idle
>> + * @MEDIA_REQUEST_STATE_VALIDATING:	Validating the request, no state changes
>> + *					allowed
>> + * @MEDIA_REQUEST_STATE_QUEUED:		Queued
>> + * @MEDIA_REQUEST_STATE_COMPLETE:	Completed, the request is done
>> + * @MEDIA_REQUEST_STATE_CLEANING:	Cleaning, the request is being re-inited
>> + */
>> +enum media_request_state {
>> +	MEDIA_REQUEST_STATE_IDLE,
>> +	MEDIA_REQUEST_STATE_VALIDATING,
>> +	MEDIA_REQUEST_STATE_QUEUED,
>> +	MEDIA_REQUEST_STATE_COMPLETE,
>> +	MEDIA_REQUEST_STATE_CLEANING,
>> +};
>> +
>> +struct media_request_object;
>> +
>> +/**
>> + * struct media_request - Media device request
>> + * @mdev: Media device this request belongs to
>> + * @kref: Reference count
>> + * @debug_str: Prefix for debug messages (process name:fd)
>> + * @state: The state of the request
>> + * @objects: List of @struct media_request_object request objects
>> + * @num_objects: The number of objects in the request
>> + * @num_incompleted_objects: The number of incomplete objects in the request
>> + * @poll_wait: Wait queue for poll
>> + * @lock: Serializes access to this struct
>> + */
>> +struct media_request {
>> +	struct media_device *mdev;
>> +	struct kref kref;
>> +	char debug_str[TASK_COMM_LEN + 11];
>> +	atomic_t state;
>> +	struct list_head objects;
>> +	unsigned int num_incomplete_objects;
>> +	struct wait_queue_head poll_wait;
>> +	spinlock_t lock;
>> +};
>> +
>> +#ifdef CONFIG_MEDIA_CONTROLLER
>> +
>> +static inline void media_request_get(struct media_request *req)
>> +{
>> +	kref_get(&req->kref);
>> +}
>> +
>> +void media_request_put(struct media_request *req);
>> +void media_request_cancel(struct media_request *req);
>> +
>> +int media_request_alloc(struct media_device *mdev,
>> +			struct media_request_alloc *alloc);
>> +#else
>> +static inline void media_request_get(struct media_request *req)
>> +{
>> +}
>> +
>> +static inline void media_request_put(struct media_request *req)
>> +{
>> +}
>> +
>> +static inline void media_request_cancel(struct media_request *req)
>> +{
>> +}
>> +
>> +#endif
>> +
>> +struct media_request_object_ops {
>> +	int (*prepare)(struct media_request_object *object);
>> +	void (*unprepare)(struct media_request_object *object);
>> +	void (*queue)(struct media_request_object *object);
>> +	void (*unbind)(struct media_request_object *object);
>> +	void (*cancel)(struct media_request_object *object);
>> +	void (*release)(struct media_request_object *object);
>> +};
>> +
>> +/**
>> + * struct media_request_object - An opaque object that belongs to a media
>> + *				 request
>> + *
>> + * @ops: object's operations
>> + * @priv: object's priv pointer
>> + * @req: the request this object belongs to (can be NULL)
>> + * @list: List entry of the object for @struct media_request
>> + * @kref: Reference count of the object, acquire before releasing req->lock
>> + * @completed: If true, then this object was completed.
>> + *
>> + * An object related to the request. This struct is embedded in the
>> + * larger object data.
>> + */
>> +struct media_request_object {
>> +	const struct media_request_object_ops *ops;
>> +	void *priv;
>> +	struct media_request *req;
>> +	struct list_head list;
>> +	struct kref kref;
>> +	bool completed;
>> +};
>> +
>> +#ifdef CONFIG_MEDIA_CONTROLLER
>> +static inline void media_request_object_get(struct media_request_object *obj)
>> +{
>> +	kref_get(&obj->kref);
>> +}
>> +
>> +/**
>> + * media_request_object_put - Put a media request object
>> + *
>> + * @obj: The object
>> + *
>> + * Put a media request object. Once all references are gone, the
>> + * object's memory is released.
>> + */
>> +void media_request_object_put(struct media_request_object *obj);
>> +
>> +/**
>> + * media_request_object_init - Initialise a media request object
>> + *
>> + * Initialise a media request object. The object will be released using the
>> + * release callback of the ops once it has no references (this function
>> + * initialises references to one).
>> + */
>> +void media_request_object_init(struct media_request_object *obj);
>> +
>> +/**
>> + * media_request_object_bind - Bind a media request object to a request
>> + */
>> +int media_request_object_bind(struct media_request *req,
>> +			      const struct media_request_object_ops *ops,
>> +			      void *priv,
>> +			      struct media_request_object *obj);
>> +
>> +void media_request_object_unbind(struct media_request_object *obj);
>> +
>> +/**
>> + * media_request_object_complete - Mark the media request object as complete
>> + */
>> +void media_request_object_complete(struct media_request_object *obj);
>> +#else
>> +static inline void media_request_object_get(struct media_request_object *obj)
>> +{
>> +}
>> +
>> +static inline void media_request_object_put(struct media_request_object *obj)
>> +{
>> +}
>> +
>> +static inline void media_request_object_init(struct media_request_object *obj)
>> +{
>> +	obj->ops = NULL;
>> +	obj->req = NULL;
>> +}
>> +
>> +static inline int media_request_object_bind(struct media_request *req,
>> +			       const struct media_request_object_ops *ops,
>> +			       void *priv,
>> +			       struct media_request_object *obj)
>> +{
>> +	return 0;
>> +}
>> +
>> +static inline void media_request_object_unbind(struct media_request_object *obj)
>> +{
>> +}
>> +
>> +static inline void media_request_object_complete(struct media_request_object *obj)
>> +{
>> +}
>> +#endif
>> +
>> +#endif
>>
> 

Regards,

	Hans

Re: [RFCv12 PATCH 05/29] media-request: add media_request_find

[Hans Verkuil]

On 03/05/18 00:06, Sakari Ailus wrote:
> Hi Hans,
> 
> Thanks for the update.
> 
> On Tue, May 01, 2018 at 11:00:27AM +0200, Hans Verkuil wrote:
>> From: Hans Verkuil <hans.verkuil@cisco.com>
>>
>> Add media_request_find() to find a request based on the file
>> descriptor.
> 
> What would you think of calling this media_request_get_by_fd() instead?
> 
> I think what the function does has changed over the time a bit but the name
> has stayed.

Good idea, done.

Regards,

	Hans

> 
>>
>> The caller has to call media_request_put() for the returned
>> request since this function increments the refcount.
>>
>> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
>> ---
>>  drivers/media/media-request.c | 44 +++++++++++++++++++++++++++++++++++
>>  include/media/media-request.h | 10 ++++++++
>>  2 files changed, 54 insertions(+)
>>
>> diff --git a/drivers/media/media-request.c b/drivers/media/media-request.c
>> index 22881d5700c8..a186db290d51 100644
>> --- a/drivers/media/media-request.c
>> +++ b/drivers/media/media-request.c
>> @@ -234,6 +234,50 @@ static const struct file_operations request_fops = {
>>  	.release = media_request_close,
>>  };
>>  
>> +/**
>> + * media_request_find - Find a request based on the file descriptor
>> + * @mdev: The media device
>> + * @request_fd: The request file handle
>> + *
>> + * Find and return the request associated with the given file descriptor, or
>> + * an error if no such request exists.
>> + *
>> + * When the function returns a request it increases its reference count. The
>> + * caller is responsible for releasing the reference by calling
>> + * media_request_put() on the request.
>> + */
>> +struct media_request *
>> +media_request_find(struct media_device *mdev, int request_fd)
>> +{
>> +	struct file *filp;
>> +	struct media_request *req;
>> +
>> +	if (!mdev || !mdev->ops ||
>> +	    !mdev->ops->req_validate || !mdev->ops->req_queue)
>> +		return ERR_PTR(-EPERM);
>> +
>> +	filp = fget(request_fd);
>> +	if (!filp)
>> +		return ERR_PTR(-ENOENT);
>> +
>> +	if (filp->f_op != &request_fops)
>> +		goto err_fput;
>> +	req = filp->private_data;
>> +	if (req->mdev != mdev)
>> +		goto err_fput;
>> +
>> +	media_request_get(req);
>> +	fput(filp);
>> +
>> +	return req;
>> +
>> +err_fput:
>> +	fput(filp);
>> +
>> +	return ERR_PTR(-ENOENT);
>> +}
>> +EXPORT_SYMBOL_GPL(media_request_find);
>> +
>>  int media_request_alloc(struct media_device *mdev,
>>  			struct media_request_alloc *alloc)
>>  {
>> diff --git a/include/media/media-request.h b/include/media/media-request.h
>> index 9051dfbc7d30..ce62fe74ebd6 100644
>> --- a/include/media/media-request.h
>> +++ b/include/media/media-request.h
>> @@ -70,6 +70,9 @@ static inline void media_request_get(struct media_request *req)
>>  void media_request_put(struct media_request *req);
>>  void media_request_cancel(struct media_request *req);
>>  
>> +struct media_request *
>> +media_request_find(struct media_device *mdev, int request_fd);
>> +
>>  int media_request_alloc(struct media_device *mdev,
>>  			struct media_request_alloc *alloc);
>>  #else
>> @@ -85,6 +88,12 @@ static inline void media_request_cancel(struct media_request *req)
>>  {
>>  }
>>  
>> +static inline struct media_request *
>> +media_request_find(struct media_device *mdev, int request_fd)
>> +{
>> +	return ERR_PTR(-ENOENT);
>> +}
>> +
>>  #endif
>>  
>>  struct media_request_object_ops {
>> @@ -188,6 +197,7 @@ static inline void media_request_object_unbind(struct media_request_object *obj)
>>  static inline void media_request_object_complete(struct media_request_object *obj)
>>  {
>>  }
>> +
>>  #endif
>>  
>>  #endif
>> -- 
>> 2.17.0
>>
> 

Re: [RFCv12 PATCH 03/29] media-request: implement media requests

[Sakari Ailus]

On Thu, May 03, 2018 at 10:21:32AM +0200, Hans Verkuil wrote:
> On 03/05/18 00:24, Sakari Ailus wrote:
> > Hi Hans,
> > 
> > On Tue, May 01, 2018 at 11:00:25AM +0200, Hans Verkuil wrote:
...
> >> +
> >> +static int media_request_close(struct inode *inode, struct file *filp)
> >> +{
> >> +	struct media_request *req = filp->private_data;
> >> +
> >> +	media_request_put(req);
> > 
> > A newline would be nice here.
> 
> Why? I do not see it adding anything of value. Some of your other 'newline'
> comments make it indeed more readable, but I don't see any benefit from it
> here.

I'd think it's nice to have an empty line before return if it's detached
from everything else.

> 
> > 
> >> +	return 0;
> >> +}
> >> +
> >> +static unsigned int media_request_poll(struct file *filp,
> >> +				       struct poll_table_struct *wait)
> >> +{
> >> +	struct media_request *req = filp->private_data;
> >> +	unsigned long flags;
> >> +	unsigned int ret = 0;
> >> +	enum media_request_state state;
> >> +
> >> +	if (!(poll_requested_events(wait) & POLLPRI))
> >> +		return 0;
> >> +
> >> +	spin_lock_irqsave(&req->lock, flags);
> >> +	state = atomic_read(&req->state);
> >> +
> >> +	if (state == MEDIA_REQUEST_STATE_COMPLETE) {
> >> +		ret = POLLPRI;
> >> +		goto unlock;
> >> +	}
> >> +	if (state == MEDIA_REQUEST_STATE_IDLE) {
> > 
> > Should this be just anything else than QUEUE or VALIDATING? You're missing
> > CLEANING here, for instance.
> 
> I changed it to != QUEUED. I don't think it is a good idea to include VALIDATING
> in this. It only makes sense to poll for the result if the request is fully queued.

Sounds good.

...

> >> +	/*
> >> +	 * If the req_validate was successful, then we mark the state as QUEUED
> >> +	 * and call req_queue. The reason we set the state first is that this
> >> +	 * allows req_queue to unbind or complete the queued objects in case
> >> +	 * they are immediately 'consumed'. State changes from QUEUED to another
> >> +	 * state can only happen if either the driver changes the state or if
> >> +	 * the user cancels the vb2 queue. The driver can only change the state
> >> +	 * after each object is queued through the req_queue op (and note that
> >> +	 * that op cannot fail), so setting the state to QUEUED up front is
> >> +	 * safe.
> >> +	 *
> >> +	 * The other reason for changing the state is if the vb2 queue is
> >> +	 * canceled, and that uses the req_queue_mutex which is still locked
> >> +	 * while req_queue is called, so that's safe as well.
> >> +	 */
> >> +	atomic_set(&req->state,
> >> +		   ret ? MEDIA_REQUEST_STATE_IDLE : MEDIA_REQUEST_STATE_QUEUED);
> >> +
> >> +	if (!ret)
> >> +		mdev->ops->req_queue(req);
> >> +
> >> +	mutex_unlock(&mdev->req_queue_mutex);
> >> +
> >> +	if (ret) {
> >> +		dev_dbg(mdev->dev, "request: can't queue %s (%d)\n",
> >> +			req->debug_str, ret);
> >> +	} else {
> >> +		media_request_get(req);
> > 
> > You'll need to get a reference before you queue the request. Otherwise it's
> > possible that it completes before you get here, and you end up accessing
> > released memory. The request refcount might be also under 0 before that
> > though.
> 
> No, that can't happen. This function implements the QUEUE ioctl, which can only
> be called by userspace through the request fd, so there is always at least one
> reference open.

Indeed, you're right.

The curly braces are unnecessary above btw.

...

> >> diff --git a/include/media/media-device.h b/include/media/media-device.h
> >> index bcc6ec434f1f..ae846208be51 100644
> >> --- a/include/media/media-device.h
> >> +++ b/include/media/media-device.h
> >> @@ -27,6 +27,7 @@
> >>  
> >>  struct ida;
> >>  struct device;
> >> +struct media_device;
> >>  
> >>  /**
> >>   * struct media_entity_notify - Media Entity Notify
> >> @@ -50,10 +51,22 @@ struct media_entity_notify {
> >>   * struct media_device_ops - Media device operations
> >>   * @link_notify: Link state change notification callback. This callback is
> >>   *		 called with the graph_mutex held.
> >> + * @req_alloc: Allocate a request
> >> + * @req_free: Free a request
> >> + * @req_validate: Validate a request, but do not queue yet
> >> + * @req_queue: Queue a validated request, cannot fail. If something goes
> >> + *	       wrong when queueing this request then it should be marked
> >> + *	       as such internally in the driver and any related buffers
> >> + *	       will eventually return to userspace with V4L2_BUF_FLAG_ERROR
> >> + *	       set.
> > 
> > Note that this is MC; I think the reference is fine but I'd make it
> > explicit this is V4L2, and possibly that it's an example.
> 
> I've changed the last line to:
> 
> "must eventually return to vb2 with state VB2_BUF_STATE_ERROR."
> 
> Since this is really a vb2 thing, not V4L2.
> 
> It's not an example, based on what I know this should really be done like
> this. If reality proves to be different, then the comment will need to change.

Yes, but this is not a place for VB2 documentation nor a conclusive
document of what a failing queue operation would mean on whichever possible
other non-MC subsystem. So the VB2 related matter here remains an example
only.

We don't seem to have other than V4L2 using MC after more than five years
but I'd still be wary of thinking this is bound to V4L2 only.

-- 
Sakari Ailus
e-mail: sakari.ailus@iki.fi

Re: [RFCv12 PATCH 03/29] media-request: implement media requests

[Hans Verkuil]

On 03/05/18 12:12, Sakari Ailus wrote:
> On Thu, May 03, 2018 at 10:21:32AM +0200, Hans Verkuil wrote:
>> On 03/05/18 00:24, Sakari Ailus wrote:
>>> Hi Hans,
>>>
>>> On Tue, May 01, 2018 at 11:00:25AM +0200, Hans Verkuil wrote:
> ...
>>>> +
>>>> +static int media_request_close(struct inode *inode, struct file *filp)
>>>> +{
>>>> +	struct media_request *req = filp->private_data;
>>>> +
>>>> +	media_request_put(req);
>>>
>>> A newline would be nice here.
>>
>> Why? I do not see it adding anything of value. Some of your other 'newline'
>> comments make it indeed more readable, but I don't see any benefit from it
>> here.
> 
> I'd think it's nice to have an empty line before return if it's detached
> from everything else.
> 
>>
>>>
>>>> +	return 0;
>>>> +}
>>>> +
>>>> +static unsigned int media_request_poll(struct file *filp,
>>>> +				       struct poll_table_struct *wait)
>>>> +{
>>>> +	struct media_request *req = filp->private_data;
>>>> +	unsigned long flags;
>>>> +	unsigned int ret = 0;
>>>> +	enum media_request_state state;
>>>> +
>>>> +	if (!(poll_requested_events(wait) & POLLPRI))
>>>> +		return 0;
>>>> +
>>>> +	spin_lock_irqsave(&req->lock, flags);
>>>> +	state = atomic_read(&req->state);
>>>> +
>>>> +	if (state == MEDIA_REQUEST_STATE_COMPLETE) {
>>>> +		ret = POLLPRI;
>>>> +		goto unlock;
>>>> +	}
>>>> +	if (state == MEDIA_REQUEST_STATE_IDLE) {
>>>
>>> Should this be just anything else than QUEUE or VALIDATING? You're missing
>>> CLEANING here, for instance.
>>
>> I changed it to != QUEUED. I don't think it is a good idea to include VALIDATING
>> in this. It only makes sense to poll for the result if the request is fully queued.
> 
> Sounds good.
> 
> ...
> 
>>>> +	/*
>>>> +	 * If the req_validate was successful, then we mark the state as QUEUED
>>>> +	 * and call req_queue. The reason we set the state first is that this
>>>> +	 * allows req_queue to unbind or complete the queued objects in case
>>>> +	 * they are immediately 'consumed'. State changes from QUEUED to another
>>>> +	 * state can only happen if either the driver changes the state or if
>>>> +	 * the user cancels the vb2 queue. The driver can only change the state
>>>> +	 * after each object is queued through the req_queue op (and note that
>>>> +	 * that op cannot fail), so setting the state to QUEUED up front is
>>>> +	 * safe.
>>>> +	 *
>>>> +	 * The other reason for changing the state is if the vb2 queue is
>>>> +	 * canceled, and that uses the req_queue_mutex which is still locked
>>>> +	 * while req_queue is called, so that's safe as well.
>>>> +	 */
>>>> +	atomic_set(&req->state,
>>>> +		   ret ? MEDIA_REQUEST_STATE_IDLE : MEDIA_REQUEST_STATE_QUEUED);
>>>> +
>>>> +	if (!ret)
>>>> +		mdev->ops->req_queue(req);
>>>> +
>>>> +	mutex_unlock(&mdev->req_queue_mutex);
>>>> +
>>>> +	if (ret) {
>>>> +		dev_dbg(mdev->dev, "request: can't queue %s (%d)\n",
>>>> +			req->debug_str, ret);
>>>> +	} else {
>>>> +		media_request_get(req);
>>>
>>> You'll need to get a reference before you queue the request. Otherwise it's
>>> possible that it completes before you get here, and you end up accessing
>>> released memory. The request refcount might be also under 0 before that
>>> though.
>>
>> No, that can't happen. This function implements the QUEUE ioctl, which can only
>> be called by userspace through the request fd, so there is always at least one
>> reference open.
> 
> Indeed, you're right.
> 
> The curly braces are unnecessary above btw.
> 
> ...
> 
>>>> diff --git a/include/media/media-device.h b/include/media/media-device.h
>>>> index bcc6ec434f1f..ae846208be51 100644
>>>> --- a/include/media/media-device.h
>>>> +++ b/include/media/media-device.h
>>>> @@ -27,6 +27,7 @@
>>>>  
>>>>  struct ida;
>>>>  struct device;
>>>> +struct media_device;
>>>>  
>>>>  /**
>>>>   * struct media_entity_notify - Media Entity Notify
>>>> @@ -50,10 +51,22 @@ struct media_entity_notify {
>>>>   * struct media_device_ops - Media device operations
>>>>   * @link_notify: Link state change notification callback. This callback is
>>>>   *		 called with the graph_mutex held.
>>>> + * @req_alloc: Allocate a request
>>>> + * @req_free: Free a request
>>>> + * @req_validate: Validate a request, but do not queue yet
>>>> + * @req_queue: Queue a validated request, cannot fail. If something goes
>>>> + *	       wrong when queueing this request then it should be marked
>>>> + *	       as such internally in the driver and any related buffers
>>>> + *	       will eventually return to userspace with V4L2_BUF_FLAG_ERROR
>>>> + *	       set.
>>>
>>> Note that this is MC; I think the reference is fine but I'd make it
>>> explicit this is V4L2, and possibly that it's an example.
>>
>> I've changed the last line to:
>>
>> "must eventually return to vb2 with state VB2_BUF_STATE_ERROR."
>>
>> Since this is really a vb2 thing, not V4L2.
>>
>> It's not an example, based on what I know this should really be done like
>> this. If reality proves to be different, then the comment will need to change.
> 
> Yes, but this is not a place for VB2 documentation nor a conclusive
> document of what a failing queue operation would mean on whichever possible
> other non-MC subsystem. So the VB2 related matter here remains an example
> only.
> 
> We don't seem to have other than V4L2 using MC after more than five years
> but I'd still be wary of thinking this is bound to V4L2 only.
> 

It's all very tightly coupled to vb2 and I think we should just be honest in the
comment. Nor do I see this ever being used in other subsystems: they have their
own streaming etc. models.

I'll keep this in unless other people complain about this.

Regards,

	Hans