[PATCH 15/81] drm: Add the atomic modeset ioctl

From: ville.syrjala@linux.intel.com
To: dri-devel@lists.freedesktop.org
Cc: intel-gfx@lists.freedesktop.org
Subject: [PATCH 15/81] drm: Add the atomic modeset ioctl
Date: Wed, 12 Dec 2012 18:15:42 +0200	[thread overview]
Message-ID: <1355329008-31459-16-git-send-email-ville.syrjala@linux.intel.com> (raw)
In-Reply-To: <1355329008-31459-1-git-send-email-ville.syrjala@linux.intel.com>

From: Ville Syrjälä <ville.syrjala@linux.intel.com>

This new ioctl can be used to update an arbitrary set of object
properties in one operation.

The ioctl simply takes a list of object IDs and property IDs and their
values. For setting values of blob properties, the property value
indicates the length of the data, and the actual data is passed via
another blob pointer.

Three flags are currently supported to alter the behaviour of the ioctl:
- DRM_MODE_ATOMIC_TEST_ONLY indicates that the new state chould only be
  checked for validity, but not hardware state is to be modified.
- DRM_MODE_ATOMIC_EVENT requests that asynchronous completion events be
  sent back to user space. A new event type is added for this purpose.
- DRM_MODE_ATOMIC_NONBLOCK indicates that the operation must be
  completed asynchronously without blocking the the caller for
  significant amounts of time.

Internally the driver must implement the functions pointers in struct
drm_atomic_funcs to support the new ioctl.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
 drivers/gpu/drm/drm_crtc.c  |  146 +++++++++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/drm_drv.c   |    1 +
 include/drm/drmP.h          |    8 +++
 include/drm/drm_crtc.h      |   13 ++++
 include/uapi/drm/drm.h      |   12 ++++
 include/uapi/drm/drm_mode.h |   17 +++++
 6 files changed, 197 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index aeda9f4..897ff46 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -4245,3 +4245,149 @@ int drm_calc_vscale(struct drm_region *src, struct drm_region *dst,
 	return vscale;
 }
 EXPORT_SYMBOL(drm_calc_vscale);
+
+int drm_mode_atomic_ioctl(struct drm_device *dev,
+			  void *data, struct drm_file *file_priv)
+{
+	struct drm_mode_atomic *arg = data;
+	uint32_t __user *objs_ptr = (uint32_t __user *)(unsigned long)(arg->objs_ptr);
+	uint32_t __user *count_props_ptr = (uint32_t __user *)(unsigned long)(arg->count_props_ptr);
+	uint32_t __user *props_ptr = (uint32_t __user *)(unsigned long)(arg->props_ptr);
+	uint64_t __user *prop_values_ptr = (uint64_t __user *)(unsigned long)(arg->prop_values_ptr);
+	uint64_t __user *blob_values_ptr = (uint64_t __user *)(unsigned long)(arg->blob_values_ptr);
+	unsigned int copied_objs = 0;
+	unsigned int copied_props = 0;
+	unsigned int copied_blobs = 0;
+	void *state;
+	int ret = 0;
+	unsigned int i, j;
+
+	if (!dev->driver->atomic_funcs ||
+	    !dev->driver->atomic_funcs->begin ||
+	    !dev->driver->atomic_funcs->set ||
+	    !dev->driver->atomic_funcs->check ||
+	    !dev->driver->atomic_funcs->commit ||
+	    !dev->driver->atomic_funcs->end)
+		return -ENOSYS;
+
+	if (arg->flags & ~(DRM_MODE_ATOMIC_TEST_ONLY | DRM_MODE_ATOMIC_EVENT | DRM_MODE_ATOMIC_NONBLOCK))
+		return -EINVAL;
+
+	/* can't test and expect an event at the same time. */
+	if (arg->flags & DRM_MODE_ATOMIC_TEST_ONLY && arg->flags & DRM_MODE_ATOMIC_EVENT)
+		return -EINVAL;
+
+	mutex_lock(&dev->mode_config.mutex);
+
+	state = dev->driver->atomic_funcs->begin(dev, file_priv, arg->flags, arg->user_data);
+	if (IS_ERR(state)) {
+		ret = PTR_ERR(state);
+		goto unlock;
+	}
+
+	for (i = 0; i < arg->count_objs; i++) {
+		uint32_t obj_id, count_props;
+		struct drm_mode_object *obj;
+
+		if (get_user(obj_id, objs_ptr + copied_objs)) {
+			ret = -EFAULT;
+			goto out;
+		}
+
+		obj = drm_mode_object_find(dev, obj_id, DRM_MODE_OBJECT_ANY);
+		if (!obj || !obj->properties) {
+			ret = -ENOENT;
+			goto out;
+		}
+
+		if (get_user(count_props, count_props_ptr + copied_objs)) {
+			ret = -EFAULT;
+			goto out;
+		}
+
+		copied_objs++;
+
+		for (j = 0; j < count_props; j++) {
+			uint32_t prop_id;
+			uint64_t prop_value;
+			struct drm_mode_object *prop_obj;
+			struct drm_property *prop;
+			void *blob_data = NULL;
+
+			if (get_user(prop_id, props_ptr + copied_props)) {
+				ret = -EFAULT;
+				goto out;
+			}
+
+			if (!object_has_prop(obj, prop_id)) {
+				ret = -EINVAL;
+				goto out;
+			}
+
+			prop_obj = drm_mode_object_find(dev, prop_id, DRM_MODE_OBJECT_PROPERTY);
+			if (!prop_obj) {
+				ret = -ENOENT;
+				goto out;
+			}
+			prop = obj_to_property(prop_obj);
+
+			if (get_user(prop_value, prop_values_ptr + copied_props)) {
+				ret = -EFAULT;
+				goto out;
+			}
+
+			if (!drm_property_change_is_valid(prop, prop_value)) {
+				ret = -EINVAL;
+				goto out;
+			}
+
+			if (prop->flags & DRM_MODE_PROP_BLOB && prop_value) {
+				uint64_t blob_ptr;
+
+				if (get_user(blob_ptr, blob_values_ptr + copied_blobs)) {
+					ret = -EFAULT;
+					goto out;
+				}
+
+				blob_data = kmalloc(prop_value, GFP_KERNEL);
+				if (!blob_data) {
+					ret = -ENOMEM;
+					goto out;
+				}
+
+				if (copy_from_user(blob_data, (void __user *)(unsigned long)blob_ptr, prop_value)) {
+					kfree(blob_data);
+					ret = -EFAULT;
+					goto out;
+				}
+			}
+
+			/* User space sends the blob pointer even if we don't use it (length==0). */
+			if (prop->flags & DRM_MODE_PROP_BLOB)
+				copied_blobs++;
+
+			/* The driver will be in charge of blob_data from now on. */
+			ret = dev->driver->atomic_funcs->set(dev, state, obj, prop, prop_value, blob_data);
+			if (ret)
+				goto out;
+
+			copied_props++;
+		}
+	}
+
+	ret = dev->driver->atomic_funcs->check(dev, state);
+	if (ret)
+		goto out;
+
+	if (arg->flags & DRM_MODE_ATOMIC_TEST_ONLY)
+		goto out;
+
+	ret = dev->driver->atomic_funcs->commit(dev, state);
+
+ out:
+	dev->driver->atomic_funcs->end(dev, state);
+ unlock:
+	mutex_unlock(&dev->mode_config.mutex);
+
+	return ret;
+}
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index be174ca..dbef305 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -166,6 +166,7 @@ static struct drm_ioctl_desc drm_ioctls[] = {
 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_GETPROPERTIES, drm_mode_obj_get_properties_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_SETPROPERTY, drm_mode_obj_set_property_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
+	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATOMIC, drm_mode_atomic_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 };
 
 #define DRM_CORE_IOCTL_COUNT	ARRAY_SIZE( drm_ioctls )
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index fad21c9..1773812 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -958,6 +958,8 @@ struct drm_driver {
 
 	/* List of devices hanging off this driver */
 	struct list_head device_list;
+
+	const struct drm_atomic_funcs *atomic_funcs;
 };
 
 #define DRM_MINOR_UNASSIGNED 0
@@ -1051,6 +1053,12 @@ struct drm_pending_vblank_event {
 	struct drm_event_vblank event;
 };
 
+struct drm_pending_atomic_event {
+	struct drm_pending_event base;
+	int pipe;
+	struct drm_event_atomic event;
+};
+
 /**
  * DRM device structure. This structure represent a complete card that
  * may contain multiple heads.
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index d05d302..77f08a3 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -1092,6 +1092,8 @@ extern int drm_mode_obj_get_properties_ioctl(struct drm_device *dev, void *data,
 					     struct drm_file *file_priv);
 extern int drm_mode_obj_set_property_ioctl(struct drm_device *dev, void *data,
 					   struct drm_file *file_priv);
+extern int drm_mode_atomic_ioctl(struct drm_device *dev,
+				 void *data, struct drm_file *file_priv);
 
 extern void drm_fb_get_bpp_depth(uint32_t format, unsigned int *depth,
 				 int *bpp);
@@ -1132,4 +1134,15 @@ extern int drm_calc_hscale(struct drm_region *src, struct drm_region *dst,
 extern int drm_calc_vscale(struct drm_region *src, struct drm_region *dst,
 			   int min_vscale, int max_vscale);
 
+struct drm_atomic_funcs {
+	void *(*begin)(struct drm_device *dev, struct drm_file *file,
+		       uint32_t flags, uint64_t user_data);
+	int (*set)(struct drm_device *dev, void *state,
+		   struct drm_mode_object *obj, struct drm_property *prop,
+		   uint64_t value, void *blob_data);
+	int (*check)(struct drm_device *dev, void *state);
+	int (*commit)(struct drm_device *dev, void *state);
+	void (*end)(struct drm_device *dev, void *state);
+};
+
 #endif /* __DRM_CRTC_H__ */
diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
index 8d1e2bb..7b057ca 100644
--- a/include/uapi/drm/drm.h
+++ b/include/uapi/drm/drm.h
@@ -732,6 +732,7 @@ struct drm_prime_handle {
 #define DRM_IOCTL_MODE_ADDFB2		DRM_IOWR(0xB8, struct drm_mode_fb_cmd2)
 #define DRM_IOCTL_MODE_OBJ_GETPROPERTIES	DRM_IOWR(0xB9, struct drm_mode_obj_get_properties)
 #define DRM_IOCTL_MODE_OBJ_SETPROPERTY	DRM_IOWR(0xBA, struct drm_mode_obj_set_property)
+#define DRM_IOCTL_MODE_ATOMIC	DRM_IOWR(0xBB, struct drm_mode_atomic)
 
 /**
  * Device specific ioctls should only be in their respective headers
@@ -763,6 +764,7 @@ struct drm_event {
 
 #define DRM_EVENT_VBLANK 0x01
 #define DRM_EVENT_FLIP_COMPLETE 0x02
+#define DRM_EVENT_ATOMIC_COMPLETE 0x03
 
 struct drm_event_vblank {
 	struct drm_event base;
@@ -773,6 +775,16 @@ struct drm_event_vblank {
 	__u32 reserved;
 };
 
+struct drm_event_atomic {
+	struct drm_event base;
+	__u64 user_data;
+	__u32 tv_sec;
+	__u32 tv_usec;
+	__u32 sequence;
+	__u32 obj_id;
+	__u32 old_fb_id;
+};
+
 #define DRM_CAP_DUMB_BUFFER 0x1
 #define DRM_CAP_VBLANK_HIGH_CRTC 0x2
 #define DRM_CAP_DUMB_PREFERRED_DEPTH 0x3
diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h
index 3d6301b..71f5e0d 100644
--- a/include/uapi/drm/drm_mode.h
+++ b/include/uapi/drm/drm_mode.h
@@ -460,4 +460,21 @@ struct drm_mode_destroy_dumb {
 	uint32_t handle;
 };
 
+
+#define DRM_MODE_ATOMIC_TEST_ONLY (1<<0)
+#define DRM_MODE_ATOMIC_EVENT (1<<1)
+#define DRM_MODE_ATOMIC_NONBLOCK (1<<2)
+
+/* FIXME come up with some sane error reporting mechanism? */
+struct drm_mode_atomic {
+	__u32 flags;
+	__u32 count_objs;
+	__u64 objs_ptr;
+	__u64 count_props_ptr;
+	__u64 props_ptr;
+	__u64 prop_values_ptr;
+	__u64 blob_values_ptr;
+	__u64 user_data;
+};
+
 #endif
-- 
1.7.8.6

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