[RFC][PATCH 0/6 v3] DMA-BUF Heaps (destaging ION)

[RFC][PATCH 0/6 v3] DMA-BUF Heaps (destaging ION)

[John Stultz]

Here is another RFC of the dma-buf heaps patchset Andrew and I
have been working on which tries to destage a fair chunk of ION
functionality.

The patchset implements per-heap devices which can be opened
directly and then an ioctl is used to allocate a dmabuf from the
heap.

The interface is similar, but much simpler then IONs, only
providing an ALLOC ioctl.

Also, I've provided simple system and cma heaps. The system
heap in particular is missing the page-pool optimizations ION
had, but works well enough to validate the interface.

I've booted and tested these patches with AOSP on the HiKey960
using the kernel tree here:
  https://git.linaro.org/people/john.stultz/android-dev.git/log/?h=dev/dma-buf-heap

And the userspace changes here:
  https://android-review.googlesource.com/c/device/linaro/hikey/+/909436


Compared to ION, this patchset is missing the system-contig,
carveout and chunk heaps, as I don't have a device that uses
those, so I'm unable to do much useful validation there.
Additionally we have no upstream users of chunk or carveout,
and the system-contig has been deprecated in the common/andoid-*
kernels, so this should be ok.

I've also removed the stats accounting for now, since it should
be implemented by the heaps themselves.


New in v3:
* Proper /dev/heap/* names on both Android and classic Linux
  environments
* Major rework of the helper code from Andrew
* Dummy test device added to test importing
* *Lots* of cleanups suggested by many (thank you for all the
  input)!


Outstanding concerns:
* Potential need for private flags in interface for secure
  heaps. Need to better understand secure heap usage.
* Making sure the performance issues from potentially unnecessary
  cache-management operations can be resolved properly for system
  and cma heaps (outstanding issue from ION).


Eventual TODOS:
* Sanity filtering for heap names
* Reimplement performance optimizations for system heap
* Add stats accounting to system/cma heaps
* Make the kselftest more useful
* Add other heaps folks see as useful (would love to get
  some help from actual carveout/chunk users)!

That said, the main user-interface is shaping up and I wanted
to get some input on the device model (particularly from GreKH)
and any other API/ABI specific input. 

thanks
-john

Cc: Laura Abbott <labbott@redhat.com>
Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Liam Mark <lmark@codeaurora.org>
Cc: Pratik Patel <pratikp@codeaurora.org>
Cc: Brian Starkey <Brian.Starkey@arm.com>
Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
Cc: Sudipto Paul <Sudipto.Paul@arm.com>
Cc: Andrew F. Davis <afd@ti.com>
Cc: Xu YiPing <xuyiping@hisilicon.com>
Cc: "Chenfeng (puck)" <puck.chen@hisilicon.com>
Cc: butao <butao@hisilicon.com>
Cc: "Xiaqing (A)" <saberlily.xia@hisilicon.com>
Cc: Yudongbin <yudongbin@hisilicon.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chenbo Feng <fengc@google.com>
Cc: Alistair Strachan <astrachan@google.com>
Cc: dri-devel@lists.freedesktop.org

Andrew F. Davis (2):
  dma-buf: Add dma-buf heaps framework
  dma-buf: Add Dummy Importer Test Device

John Stultz (4):
  dma-buf: heaps: Add heap helpers
  dma-buf: heaps: Add system heap to dmabuf heaps
  dma-buf: heaps: Add CMA heap to dmabuf heapss
  kselftests: Add dma-heap test

 MAINTAINERS                                        |  18 ++
 drivers/dma-buf/Kconfig                            |  16 ++
 drivers/dma-buf/Makefile                           |   3 +
 drivers/dma-buf/dma-buf-testdev.c                  | 239 +++++++++++++++++++
 drivers/dma-buf/dma-heap.c                         | 234 ++++++++++++++++++
 drivers/dma-buf/heaps/Kconfig                      |  14 ++
 drivers/dma-buf/heaps/Makefile                     |   4 +
 drivers/dma-buf/heaps/cma_heap.c                   | 170 ++++++++++++++
 drivers/dma-buf/heaps/heap-helpers.c               | 261 +++++++++++++++++++++
 drivers/dma-buf/heaps/heap-helpers.h               |  55 +++++
 drivers/dma-buf/heaps/system_heap.c                | 120 ++++++++++
 include/linux/dma-heap.h                           |  58 +++++
 include/uapi/linux/dma-buf-testdev.h               |  37 +++
 include/uapi/linux/dma-heap.h                      |  52 ++++
 tools/testing/selftests/dmabuf-heaps/Makefile      |  11 +
 tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c | 169 +++++++++++++
 16 files changed, 1461 insertions(+)
 create mode 100644 drivers/dma-buf/dma-buf-testdev.c
 create mode 100644 drivers/dma-buf/dma-heap.c
 create mode 100644 drivers/dma-buf/heaps/Kconfig
 create mode 100644 drivers/dma-buf/heaps/Makefile
 create mode 100644 drivers/dma-buf/heaps/cma_heap.c
 create mode 100644 drivers/dma-buf/heaps/heap-helpers.c
 create mode 100644 drivers/dma-buf/heaps/heap-helpers.h
 create mode 100644 drivers/dma-buf/heaps/system_heap.c
 create mode 100644 include/linux/dma-heap.h
 create mode 100644 include/uapi/linux/dma-buf-testdev.h
 create mode 100644 include/uapi/linux/dma-heap.h
 create mode 100644 tools/testing/selftests/dmabuf-heaps/Makefile
 create mode 100644 tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c

-- 
2.7.4

[RFC][PATCH 1/6 v3] dma-buf: Add dma-buf heaps framework

[John Stultz]

From: "Andrew F. Davis" <afd@ti.com>

This framework allows a unified userspace interface for dma-buf
exporters, allowing userland to allocate specific types of memory
for use in dma-buf sharing.

Each heap is given its own device node, which a user can allocate
a dma-buf fd from using the DMA_HEAP_IOC_ALLOC.

This code is an evoluiton of the Android ION implementation,
and a big thanks is due to its authors/maintainers over time
for their effort:
  Rebecca Schultz Zavin, Colin Cross, Benjamin Gaignard,
  Laura Abbott, and many other contributors!

Cc: Laura Abbott <labbott@redhat.com>
Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Liam Mark <lmark@codeaurora.org>
Cc: Pratik Patel <pratikp@codeaurora.org>
Cc: Brian Starkey <Brian.Starkey@arm.com>
Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
Cc: Sudipto Paul <Sudipto.Paul@arm.com>
Cc: Andrew F. Davis <afd@ti.com>
Cc: Xu YiPing <xuyiping@hisilicon.com>
Cc: "Chenfeng (puck)" <puck.chen@hisilicon.com>
Cc: butao <butao@hisilicon.com>
Cc: "Xiaqing (A)" <saberlily.xia@hisilicon.com>
Cc: Yudongbin <yudongbin@hisilicon.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chenbo Feng <fengc@google.com>
Cc: Alistair Strachan <astrachan@google.com>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
v2:
* Folded down fixes I had previously shared in implementing
  heaps
* Make flags a u64 (Suggested by Laura)
* Add PAGE_ALIGN() fix to the core alloc funciton
* IOCTL fixups suggested by Brian
* Added fixes suggested by Benjamin
* Removed core stats mgmt, as that should be implemented by
  per-heap code
* Changed alloc to return a dma-buf fd, rather then a buffer
  (as it simplifies error handling)
v3:
* Removed scare-quotes in MAINTAINERS email address
* Get rid of .release function as it didn't do anything (from
  Christoph)
* Renamed filp to file (suggested by Christoph)
* Split out ioctl handling to separate function (suggested by
  Christoph)
* Add comment documenting PAGE_ALIGN usage (suggested by Brian)
* Switch from idr to Xarray (suggested by Brian)
* Fixup cdev creation (suggested by Brian)
* Avoid EXPORT_SYMBOL until we finalize modules (suggested by
  Brian)
* Make struct dma_heap internal only (folded in from Andrew)
* Small cleanups suggested by GregKH
* Provide class->devnode callback to get consistent /dev/
  subdirectory naming (Suggested by Bjorn)
---
 MAINTAINERS                   |  18 ++++
 drivers/dma-buf/Kconfig       |   8 ++
 drivers/dma-buf/Makefile      |   1 +
 drivers/dma-buf/dma-heap.c    | 234 ++++++++++++++++++++++++++++++++++++++++++
 include/linux/dma-heap.h      |  70 +++++++++++++
 include/uapi/linux/dma-heap.h |  52 ++++++++++
 6 files changed, 383 insertions(+)
 create mode 100644 drivers/dma-buf/dma-heap.c
 create mode 100644 include/linux/dma-heap.h
 create mode 100644 include/uapi/linux/dma-heap.h

diff --git a/MAINTAINERS b/MAINTAINERS
index c0057dd..cd9c495 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4719,6 +4719,24 @@ F:	include/linux/*fence.h
 F:	Documentation/driver-api/dma-buf.rst
 T:	git git://anongit.freedesktop.org/drm/drm-misc
 
+DMA-BUF HEAPS FRAMEWORK
+M:	Sumit Semwal <sumit.semwal@linaro.org>
+R:	Andrew F. Davis <afd@ti.com>
+R:	Benjamin Gaignard <benjamin.gaignard@linaro.org>
+R:	Liam Mark <lmark@codeaurora.org>
+R:	Laura Abbott <labbott@redhat.com>
+R:	Brian Starkey <Brian.Starkey@arm.com>
+R:	John Stultz <john.stultz@linaro.org>
+S:	Maintained
+L:	linux-media@vger.kernel.org
+L:	dri-devel@lists.freedesktop.org
+L:	linaro-mm-sig@lists.linaro.org (moderated for non-subscribers)
+F:	include/uapi/linux/dma-heap.h
+F:	include/linux/dma-heap.h
+F:	drivers/dma-buf/dma-heap.c
+F:	drivers/dma-buf/heaps/*
+T:	git git://anongit.freedesktop.org/drm/drm-misc
+
 DMA GENERIC OFFLOAD ENGINE SUBSYSTEM
 M:	Vinod Koul <vkoul@kernel.org>
 L:	dmaengine@vger.kernel.org
diff --git a/drivers/dma-buf/Kconfig b/drivers/dma-buf/Kconfig
index 2e5a0fa..09c61db 100644
--- a/drivers/dma-buf/Kconfig
+++ b/drivers/dma-buf/Kconfig
@@ -39,4 +39,12 @@ config UDMABUF
 	  A driver to let userspace turn memfd regions into dma-bufs.
 	  Qemu can use this to create host dmabufs for guest framebuffers.
 
+menuconfig DMABUF_HEAPS
+	bool "DMA-BUF Userland Memory Heaps"
+	select DMA_SHARED_BUFFER
+	help
+	  Choose this option to enable the DMA-BUF userland memory heaps,
+	  this allows userspace to allocate dma-bufs that can be shared between
+	  drivers.
+
 endmenu
diff --git a/drivers/dma-buf/Makefile b/drivers/dma-buf/Makefile
index 0913a6c..b0332f1 100644
--- a/drivers/dma-buf/Makefile
+++ b/drivers/dma-buf/Makefile
@@ -1,4 +1,5 @@
 obj-y := dma-buf.o dma-fence.o dma-fence-array.o reservation.o seqno-fence.o
+obj-$(CONFIG_DMABUF_HEAPS)	+= dma-heap.o
 obj-$(CONFIG_SYNC_FILE)		+= sync_file.o
 obj-$(CONFIG_SW_SYNC)		+= sw_sync.o sync_debug.o
 obj-$(CONFIG_UDMABUF)		+= udmabuf.o
diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c
new file mode 100644
index 0000000..b52959e
--- /dev/null
+++ b/drivers/dma-buf/dma-heap.c
@@ -0,0 +1,234 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Framework for userspace DMA-BUF allocations
+ *
+ * Copyright (C) 2011 Google, Inc.
+ * Copyright (C) 2019 Linaro Ltd.
+ */
+
+#include <linux/cdev.h>
+#include <linux/debugfs.h>
+#include <linux/device.h>
+#include <linux/dma-buf.h>
+#include <linux/err.h>
+#include <linux/xarray.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+
+#include <linux/dma-heap.h>
+#include <uapi/linux/dma-heap.h>
+
+#define DEVNAME "dma_heap"
+
+#define NUM_HEAP_MINORS 128
+
+/**
+ * struct dma_heap - represents a dmabuf heap in the system
+ * @name:		used for debugging/device-node name
+ * @ops:		ops struct for this heap
+ * @minor		minor number of this heap device
+ * @heap_devt		heap device node
+ * @heap_cdev		heap char device
+ *
+ * Represents a heap of memory from which buffers can be made.
+ */
+struct dma_heap {
+	const char *name;
+	struct dma_heap_ops *ops;
+	void *priv;
+	unsigned int minor;
+	dev_t heap_devt;
+	struct cdev heap_cdev;
+};
+
+static dev_t dma_heap_devt;
+static struct class *dma_heap_class;
+static DEFINE_XARRAY_ALLOC(dma_heap_minors);
+
+static int dma_heap_buffer_alloc(struct dma_heap *heap, size_t len,
+				 unsigned int flags)
+{
+	/*
+	 * Allocations from all heaps have to begin
+	 * and end on page boundaries.
+	 */
+	len = PAGE_ALIGN(len);
+	if (!len)
+		return -EINVAL;
+
+	return heap->ops->allocate(heap, len, flags);
+}
+
+static int dma_heap_open(struct inode *inode, struct file *file)
+{
+	struct dma_heap *heap;
+
+	heap = xa_load(&dma_heap_minors, iminor(inode));
+	if (!heap) {
+		pr_err("dma_heap: minor %d unknown.\n", iminor(inode));
+		return -ENODEV;
+	}
+
+	/* instance data as context */
+	file->private_data = heap;
+	nonseekable_open(inode, file);
+
+	return 0;
+}
+
+static long dma_heap_ioctl_allocate(struct file *file, unsigned long arg)
+{
+	struct dma_heap_allocation_data heap_allocation;
+	struct dma_heap *heap = file->private_data;
+	int fd;
+
+	if (copy_from_user(&heap_allocation, (void __user *)arg,
+			   sizeof(heap_allocation)))
+		return -EFAULT;
+
+	if (heap_allocation.fd ||
+	    heap_allocation.reserved0 ||
+	    heap_allocation.reserved1 ||
+	    heap_allocation.reserved2) {
+		pr_warn_once("dma_heap: ioctl data not valid\n");
+		return -EINVAL;
+	}
+
+	if (heap_allocation.flags & ~DMA_HEAP_VALID_FLAGS) {
+		pr_warn_once("dma_heap: flags has invalid or unsupported flags set\n");
+		return -EINVAL;
+	}
+
+	fd = dma_heap_buffer_alloc(heap, heap_allocation.len,
+				   heap_allocation.flags);
+	if (fd < 0)
+		return fd;
+
+	heap_allocation.fd = fd;
+
+	if (copy_to_user((void __user *)arg, &heap_allocation,
+			 sizeof(heap_allocation)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static long dma_heap_ioctl(struct file *file, unsigned int cmd,
+			   unsigned long arg)
+{
+	int ret = 0;
+
+	switch (cmd) {
+	case DMA_HEAP_IOC_ALLOC:
+		ret = dma_heap_ioctl_allocate(file, arg);
+		break;
+	default:
+		return -ENOTTY;
+	}
+
+	return ret;
+}
+
+static const struct file_operations dma_heap_fops = {
+	.owner          = THIS_MODULE,
+	.open		= dma_heap_open,
+	.unlocked_ioctl = dma_heap_ioctl,
+};
+
+/**
+ * dma_heap_get_data() - get per-subdriver data for the heap
+ * @heap: DMA-Heap to retrieve private data for
+ *
+ * Returns:
+ * The per-subdriver data for the heap.
+ */
+void *dma_heap_get_data(struct dma_heap *heap)
+{
+	return heap->priv;
+}
+
+struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info)
+{
+	struct dma_heap *heap;
+	struct device *dev_ret;
+	int ret;
+
+	if (!exp_info->name || !strcmp(exp_info->name, "")) {
+		pr_err("dma_heap: Cannot add heap without a name\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (!exp_info->ops || !exp_info->ops->allocate) {
+		pr_err("dma_heap: Cannot add heap with invalid ops struct\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	heap = kzalloc(sizeof(*heap), GFP_KERNEL);
+	if (!heap)
+		return ERR_PTR(-ENOMEM);
+
+	heap->name = exp_info->name;
+	heap->ops = exp_info->ops;
+	heap->priv = exp_info->priv;
+
+	/* Find unused minor number */
+	ret = xa_alloc(&dma_heap_minors, &heap->minor, heap,
+			XA_LIMIT(0, NUM_HEAP_MINORS - 1), GFP_KERNEL);
+	if (ret < 0) {
+		pr_err("dma_heap: Unable to get minor number for heap\n");
+		return ERR_PTR(ret);
+	}
+
+	/* Create device */
+	heap->heap_devt = MKDEV(MAJOR(dma_heap_devt), heap->minor);
+
+	cdev_init(&heap->heap_cdev, &dma_heap_fops);
+	ret = cdev_add(&heap->heap_cdev, heap->heap_devt, 1);
+	if (ret < 0) {
+		pr_err("dma_heap: Unable to add char device\n");
+		return ERR_PTR(ret);
+	}
+
+	/*
+	 * TODO: Need to filter "name" to make
+	 * sure we don't add something crazy
+	 */
+	dev_ret = device_create(dma_heap_class,
+				NULL,
+				heap->heap_devt,
+				NULL,
+				heap->name);
+	if (IS_ERR(dev_ret)) {
+		pr_err("dma_heap: Unable to create device\n");
+		cdev_del(&heap->heap_cdev);
+		return (struct dma_heap *)dev_ret;
+	}
+
+	return heap;
+}
+
+static char *dma_heap_devnode(struct device *dev, umode_t *mode)
+{
+	return kasprintf(GFP_KERNEL, "dma_heap/%s", dev_name(dev));
+}
+
+
+static int dma_heap_init(void)
+{
+	int ret;
+
+	ret = alloc_chrdev_region(&dma_heap_devt, 0, NUM_HEAP_MINORS, DEVNAME);
+	if (ret)
+		return ret;
+
+	dma_heap_class = class_create(THIS_MODULE, DEVNAME);
+	if (IS_ERR(dma_heap_class)) {
+		unregister_chrdev_region(dma_heap_devt, NUM_HEAP_MINORS);
+		return PTR_ERR(dma_heap_class);
+	}
+	dma_heap_class->devnode = dma_heap_devnode;
+
+	return 0;
+}
+subsys_initcall(dma_heap_init);
diff --git a/include/linux/dma-heap.h b/include/linux/dma-heap.h
new file mode 100644
index 0000000..d7bf624
--- /dev/null
+++ b/include/linux/dma-heap.h
@@ -0,0 +1,70 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * DMABUF Heaps Allocation Infrastructure
+ *
+ * Copyright (C) 2011 Google, Inc.
+ * Copyright (C) 2019 Linaro Ltd.
+ */
+
+#ifndef _DMA_HEAPS_H
+#define _DMA_HEAPS_H
+
+#include <linux/cdev.h>
+#include <linux/types.h>
+
+/**
+ * struct dma_heap_buffer - metadata for a particular buffer
+ * @heap:		back pointer to the heap the buffer came from
+ * @dmabuf:		backing dma-buf for this buffer
+ * @size:		size of the buffer
+ * @flags:		buffer specific flags
+ */
+struct dma_heap_buffer {
+	struct dma_heap *heap;
+	struct dma_buf *dmabuf;
+	size_t size;
+	unsigned long flags;
+};
+
+/**
+ * struct dma_heap_ops - ops to operate on a given heap
+ * @allocate:		allocate dmabuf and return fd
+ *
+ * allocate returns dmabuf fd  on success, -errno on error.
+ */
+struct dma_heap_ops {
+	int (*allocate)(struct dma_heap *heap,
+			unsigned long len,
+			unsigned long flags);
+};
+
+/**
+ * struct dma_heap_export_info - information needed to export a new dmabuf heap
+ * @name:	used for debugging/device-node name
+ * @ops:	ops struct for this heap
+ * @priv:	heap exporter private data
+ *
+ * Information needed to export a new dmabuf heap.
+ */
+struct dma_heap_export_info {
+	const char *name;
+	struct dma_heap_ops *ops;
+	void *priv;
+};
+
+/**
+ * dma_heap_get_data() - get per-heap driver data
+ * @heap: DMA-Heap to retrieve private data for
+ *
+ * Returns:
+ * The per-heap data for the heap.
+ */
+void *dma_heap_get_data(struct dma_heap *heap);
+
+/**
+ * dma_heap_add - adds a heap to dmabuf heaps
+ * @exp_info:		information needed to register this heap
+ */
+struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info);
+
+#endif /* _DMA_HEAPS_H */
diff --git a/include/uapi/linux/dma-heap.h b/include/uapi/linux/dma-heap.h
new file mode 100644
index 0000000..0869811
--- /dev/null
+++ b/include/uapi/linux/dma-heap.h
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * DMABUF Heaps Userspace API
+ *
+ * Copyright (C) 2011 Google, Inc.
+ * Copyright (C) 2019 Linaro Ltd.
+ */
+#ifndef _UAPI_LINUX_DMABUF_POOL_H
+#define _UAPI_LINUX_DMABUF_POOL_H
+
+#include <linux/ioctl.h>
+#include <linux/types.h>
+
+/**
+ * DOC: DMABUF Heaps Userspace API
+ *
+ */
+
+/* Currently no flags */
+#define DMA_HEAP_VALID_FLAGS (0)
+
+/**
+ * struct dma_heap_allocation_data - metadata passed from userspace for
+ *                                      allocations
+ * @len:		size of the allocation
+ * @flags:		flags passed to pool
+ * @fd:			will be populated with a fd which provdes the
+ *			handle to the allocated dma-buf
+ *
+ * Provided by userspace as an argument to the ioctl
+ */
+struct dma_heap_allocation_data {
+	__u64 len;
+	__u64 flags;
+	__u32 fd;
+	__u32 reserved0;
+	__u32 reserved1;
+	__u32 reserved2;
+};
+
+#define DMA_HEAP_IOC_MAGIC		'H'
+
+/**
+ * DOC: DMA_HEAP_IOC_ALLOC - allocate memory from pool
+ *
+ * Takes an dma_heap_allocation_data struct and returns it with the fd field
+ * populated with the dmabuf handle of the allocation.
+ */
+#define DMA_HEAP_IOC_ALLOC	_IOWR(DMA_HEAP_IOC_MAGIC, 0, \
+				      struct dma_heap_allocation_data)
+
+#endif /* _UAPI_LINUX_DMABUF_POOL_H */
-- 
2.7.4

[RFC][PATCH 2/6 v3] dma-buf: heaps: Add heap helpers

[John Stultz]

Add generic helper dmabuf ops for dma heaps, so we can reduce
the amount of duplicative code for the exported dmabufs.

This code is an evolution of the Android ION implementation, so
thanks to its original authors and maintainters:
  Rebecca Schultz Zavin, Colin Cross, Laura Abbott, and others!

Cc: Laura Abbott <labbott@redhat.com>
Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Liam Mark <lmark@codeaurora.org>
Cc: Pratik Patel <pratikp@codeaurora.org>
Cc: Brian Starkey <Brian.Starkey@arm.com>
Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
Cc: Sudipto Paul <Sudipto.Paul@arm.com>
Cc: Andrew F. Davis <afd@ti.com>
Cc: Xu YiPing <xuyiping@hisilicon.com>
Cc: "Chenfeng (puck)" <puck.chen@hisilicon.com>
Cc: butao <butao@hisilicon.com>
Cc: "Xiaqing (A)" <saberlily.xia@hisilicon.com>
Cc: Yudongbin <yudongbin@hisilicon.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chenbo Feng <fengc@google.com>
Cc: Alistair Strachan <astrachan@google.com>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
v2:
* Removed cache management performance hack that I had
  accidentally folded in.
* Removed stats code that was in helpers
* Lots of checkpatch cleanups

v3:
* Uninline INIT_HEAP_HELPER_BUFFER (suggested by Christoph)
* Switch to WARN on buffer destroy failure (suggested by Brian)
* buffer->kmap_cnt decrementing cleanup (suggested by Christoph)
* Extra buffer->vaddr checking in dma_heap_dma_buf_kmap
  (suggested by Brian)
* Switch to_helper_buffer from macro to inline function
  (suggested by Benjamin)
* Rename kmap->vmap (folded in from Andrew)
* Use vmap for vmapping - not begin_cpu_access (folded in from
  Andrew)
* Drop kmap for now, as its optional (folded in from Andrew)
* Fold dma_heap_map_user into the single caller (foled in from
  Andrew)
* Folded in patch from Andrew to track page list per heap not
  sglist, which simplifies the tracking logic
---
 drivers/dma-buf/Makefile             |   1 +
 drivers/dma-buf/heaps/Makefile       |   2 +
 drivers/dma-buf/heaps/heap-helpers.c | 261 +++++++++++++++++++++++++++++++++++
 drivers/dma-buf/heaps/heap-helpers.h |  55 ++++++++
 include/linux/dma-heap.h             |  14 +-
 5 files changed, 320 insertions(+), 13 deletions(-)
 create mode 100644 drivers/dma-buf/heaps/Makefile
 create mode 100644 drivers/dma-buf/heaps/heap-helpers.c
 create mode 100644 drivers/dma-buf/heaps/heap-helpers.h

diff --git a/drivers/dma-buf/Makefile b/drivers/dma-buf/Makefile
index b0332f1..09c2f2d 100644
--- a/drivers/dma-buf/Makefile
+++ b/drivers/dma-buf/Makefile
@@ -1,4 +1,5 @@
 obj-y := dma-buf.o dma-fence.o dma-fence-array.o reservation.o seqno-fence.o
+obj-$(CONFIG_DMABUF_HEAPS)	+= heaps/
 obj-$(CONFIG_DMABUF_HEAPS)	+= dma-heap.o
 obj-$(CONFIG_SYNC_FILE)		+= sync_file.o
 obj-$(CONFIG_SW_SYNC)		+= sw_sync.o sync_debug.o
diff --git a/drivers/dma-buf/heaps/Makefile b/drivers/dma-buf/heaps/Makefile
new file mode 100644
index 0000000..de49898
--- /dev/null
+++ b/drivers/dma-buf/heaps/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-y					+= heap-helpers.o
diff --git a/drivers/dma-buf/heaps/heap-helpers.c b/drivers/dma-buf/heaps/heap-helpers.c
new file mode 100644
index 0000000..00cbdbb
--- /dev/null
+++ b/drivers/dma-buf/heaps/heap-helpers.c
@@ -0,0 +1,261 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/device.h>
+#include <linux/dma-buf.h>
+#include <linux/err.h>
+#include <linux/idr.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <uapi/linux/dma-heap.h>
+
+#include "heap-helpers.h"
+
+void INIT_HEAP_HELPER_BUFFER(struct heap_helper_buffer *buffer,
+			     void (*free)(struct heap_helper_buffer *))
+{
+	buffer->private_flags = 0;
+	buffer->priv_virt = NULL;
+	mutex_init(&buffer->lock);
+	buffer->vmap_cnt = 0;
+	buffer->vaddr = NULL;
+	INIT_LIST_HEAD(&buffer->attachments);
+	buffer->free = free;
+}
+
+
+static void *dma_heap_map_kernel(struct heap_helper_buffer *buffer)
+{
+	void *vaddr;
+
+	vaddr = vmap(buffer->pages, buffer->pagecount, VM_MAP, PAGE_KERNEL);
+	if (!vaddr)
+		return ERR_PTR(-ENOMEM);
+
+	return vaddr;
+}
+
+void dma_heap_buffer_destroy(struct dma_heap_buffer *heap_buffer)
+{
+	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
+
+	if (buffer->vmap_cnt > 0) {
+		WARN("%s: buffer still mapped in the kernel\n",
+			     __func__);
+		vunmap(buffer->vaddr);
+	}
+
+	buffer->free(buffer);
+}
+
+static void *dma_heap_buffer_vmap_get(struct dma_heap_buffer *heap_buffer)
+{
+	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
+	void *vaddr;
+
+	if (buffer->vmap_cnt) {
+		buffer->vmap_cnt++;
+		return buffer->vaddr;
+	}
+	vaddr = dma_heap_map_kernel(buffer);
+	if (WARN_ONCE(!vaddr,
+		      "heap->ops->map_kernel should return ERR_PTR on error"))
+		return ERR_PTR(-EINVAL);
+	if (IS_ERR(vaddr))
+		return vaddr;
+	buffer->vaddr = vaddr;
+	buffer->vmap_cnt++;
+	return vaddr;
+}
+
+static void dma_heap_buffer_vmap_put(struct dma_heap_buffer *heap_buffer)
+{
+	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
+
+	if (!--buffer->vmap_cnt) {
+		vunmap(buffer->vaddr);
+		buffer->vaddr = NULL;
+	}
+}
+
+struct dma_heaps_attachment {
+	struct device *dev;
+	struct sg_table table;
+	struct list_head list;
+};
+
+static int dma_heap_attach(struct dma_buf *dmabuf,
+			      struct dma_buf_attachment *attachment)
+{
+	struct dma_heaps_attachment *a;
+	struct dma_heap_buffer *heap_buffer = dmabuf->priv;
+	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
+	int ret;
+
+	a = kzalloc(sizeof(*a), GFP_KERNEL);
+	if (!a)
+		return -ENOMEM;
+
+	ret = sg_alloc_table_from_pages(&a->table, buffer->pages,
+					buffer->pagecount, 0,
+					buffer->pagecount << PAGE_SHIFT,
+					GFP_KERNEL);
+	if (ret) {
+		kfree(a);
+		return ret;
+	}
+
+	a->dev = attachment->dev;
+	INIT_LIST_HEAD(&a->list);
+
+	attachment->priv = a;
+
+	mutex_lock(&buffer->lock);
+	list_add(&a->list, &buffer->attachments);
+	mutex_unlock(&buffer->lock);
+
+	return 0;
+}
+
+static void dma_heap_detatch(struct dma_buf *dmabuf,
+				struct dma_buf_attachment *attachment)
+{
+	struct dma_heaps_attachment *a = attachment->priv;
+	struct dma_heap_buffer *heap_buffer = dmabuf->priv;
+	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
+
+	mutex_lock(&buffer->lock);
+	list_del(&a->list);
+	mutex_unlock(&buffer->lock);
+
+	sg_free_table(&a->table);
+	kfree(a);
+}
+
+static struct sg_table *dma_heap_map_dma_buf(
+					struct dma_buf_attachment *attachment,
+					enum dma_data_direction direction)
+{
+	struct dma_heaps_attachment *a = attachment->priv;
+	struct sg_table *table;
+
+	table = &a->table;
+
+	if (!dma_map_sg(attachment->dev, table->sgl, table->nents,
+			direction))
+		table = ERR_PTR(-ENOMEM);
+	return table;
+}
+
+static void dma_heap_unmap_dma_buf(struct dma_buf_attachment *attachment,
+			      struct sg_table *table,
+			      enum dma_data_direction direction)
+{
+	dma_unmap_sg(attachment->dev, table->sgl, table->nents, direction);
+}
+
+static vm_fault_t dma_heap_vm_fault(struct vm_fault *vmf)
+{
+	struct vm_area_struct *vma = vmf->vma;
+	struct heap_helper_buffer *buffer = vma->vm_private_data;
+
+	vmf->page = buffer->pages[vmf->pgoff];
+	get_page(vmf->page);
+
+	return 0;
+}
+
+static const struct vm_operations_struct dma_heap_vm_ops = {
+	.fault = dma_heap_vm_fault,
+};
+
+static int dma_heap_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
+{
+	struct dma_heap_buffer *heap_buffer = dmabuf->priv;
+	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
+
+	if ((vma->vm_flags & (VM_SHARED | VM_MAYSHARE)) == 0)
+		return -EINVAL;
+
+	vma->vm_ops = &dma_heap_vm_ops;
+	vma->vm_private_data = buffer;
+
+	return 0;
+}
+
+static void dma_heap_dma_buf_release(struct dma_buf *dmabuf)
+{
+	struct dma_heap_buffer *buffer = dmabuf->priv;
+
+	dma_heap_buffer_destroy(buffer);
+}
+
+static int dma_heap_dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
+					enum dma_data_direction direction)
+{
+	struct dma_heap_buffer *heap_buffer = dmabuf->priv;
+	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
+	struct dma_heaps_attachment *a;
+	int ret = 0;
+
+	mutex_lock(&buffer->lock);
+	list_for_each_entry(a, &buffer->attachments, list) {
+		dma_sync_sg_for_cpu(a->dev, a->table.sgl, a->table.nents,
+				    direction);
+	}
+	mutex_unlock(&buffer->lock);
+
+	return ret;
+}
+
+static int dma_heap_dma_buf_end_cpu_access(struct dma_buf *dmabuf,
+				      enum dma_data_direction direction)
+{
+	struct dma_heap_buffer *heap_buffer = dmabuf->priv;
+	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
+	struct dma_heaps_attachment *a;
+
+	mutex_lock(&buffer->lock);
+	list_for_each_entry(a, &buffer->attachments, list) {
+		dma_sync_sg_for_device(a->dev, a->table.sgl, a->table.nents,
+				       direction);
+	}
+	mutex_unlock(&buffer->lock);
+
+	return 0;
+}
+
+void *dma_heap_dma_buf_vmap(struct dma_buf *dmabuf)
+{
+	struct dma_heap_buffer *heap_buffer = dmabuf->priv;
+	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
+	void *vaddr;
+
+	mutex_lock(&buffer->lock);
+	vaddr = dma_heap_buffer_vmap_get(heap_buffer);
+	mutex_unlock(&buffer->lock);
+
+	return vaddr;
+}
+
+void dma_heap_dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr)
+{
+	struct dma_heap_buffer *heap_buffer = dmabuf->priv;
+	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
+
+	mutex_lock(&buffer->lock);
+	dma_heap_buffer_vmap_put(heap_buffer);
+	mutex_unlock(&buffer->lock);
+}
+
+const struct dma_buf_ops heap_helper_ops = {
+	.map_dma_buf = dma_heap_map_dma_buf,
+	.unmap_dma_buf = dma_heap_unmap_dma_buf,
+	.mmap = dma_heap_mmap,
+	.release = dma_heap_dma_buf_release,
+	.attach = dma_heap_attach,
+	.detach = dma_heap_detatch,
+	.begin_cpu_access = dma_heap_dma_buf_begin_cpu_access,
+	.end_cpu_access = dma_heap_dma_buf_end_cpu_access,
+	.vmap = dma_heap_dma_buf_vmap,
+	.vunmap = dma_heap_dma_buf_vunmap,
+};
diff --git a/drivers/dma-buf/heaps/heap-helpers.h b/drivers/dma-buf/heaps/heap-helpers.h
new file mode 100644
index 0000000..a17502d
--- /dev/null
+++ b/drivers/dma-buf/heaps/heap-helpers.h
@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * DMABUF Heaps helper code
+ *
+ * Copyright (C) 2011 Google, Inc.
+ * Copyright (C) 2019 Linaro Ltd.
+ */
+
+#ifndef _HEAP_HELPERS_H
+#define _HEAP_HELPERS_H
+
+#include <linux/dma-heap.h>
+#include <linux/list.h>
+
+/**
+ * struct dma_heap_buffer - metadata for a particular buffer
+ * @heap:		back pointer to the heap the buffer came from
+ * @dmabuf:		backing dma-buf for this buffer
+ * @size:		size of the buffer
+ * @flags:		buffer specific flags
+ */
+struct dma_heap_buffer {
+	struct dma_heap *heap;
+	struct dma_buf *dmabuf;
+	size_t size;
+	unsigned long flags;
+};
+
+struct heap_helper_buffer {
+	struct dma_heap_buffer heap_buffer;
+
+	unsigned long private_flags;
+	void *priv_virt;
+	struct mutex lock;
+	int vmap_cnt;
+	void *vaddr;
+	pgoff_t pagecount;
+	struct page **pages;
+	struct list_head attachments;
+
+	void (*free)(struct heap_helper_buffer *buffer);
+
+};
+
+static inline struct heap_helper_buffer *to_helper_buffer(
+						struct dma_heap_buffer *h)
+{
+	return container_of(h, struct heap_helper_buffer, heap_buffer);
+}
+
+void INIT_HEAP_HELPER_BUFFER(struct heap_helper_buffer *buffer,
+				 void (*free)(struct heap_helper_buffer *));
+extern const struct dma_buf_ops heap_helper_ops;
+
+#endif /* _HEAP_HELPERS_H */
diff --git a/include/linux/dma-heap.h b/include/linux/dma-heap.h
index d7bf624..d17b839 100644
--- a/include/linux/dma-heap.h
+++ b/include/linux/dma-heap.h
@@ -12,19 +12,7 @@
 #include <linux/cdev.h>
 #include <linux/types.h>
 
-/**
- * struct dma_heap_buffer - metadata for a particular buffer
- * @heap:		back pointer to the heap the buffer came from
- * @dmabuf:		backing dma-buf for this buffer
- * @size:		size of the buffer
- * @flags:		buffer specific flags
- */
-struct dma_heap_buffer {
-	struct dma_heap *heap;
-	struct dma_buf *dmabuf;
-	size_t size;
-	unsigned long flags;
-};
+struct dma_heap;
 
 /**
  * struct dma_heap_ops - ops to operate on a given heap
-- 
2.7.4

[RFC][PATCH 3/6 v3] dma-buf: heaps: Add system heap to dmabuf heaps

[John Stultz]

This patch adds system heap to the dma-buf heaps framework.

This allows applications to get a page-allocator backed dma-buf
for non-contiguous memory.

This code is an evolution of the Android ION implementation, so
thanks to its original authors and maintainters:
  Rebecca Schultz Zavin, Colin Cross, Laura Abbott, and others!

Cc: Laura Abbott <labbott@redhat.com>
Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Liam Mark <lmark@codeaurora.org>
Cc: Pratik Patel <pratikp@codeaurora.org>
Cc: Brian Starkey <Brian.Starkey@arm.com>
Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
Cc: Sudipto Paul <Sudipto.Paul@arm.com>
Cc: Andrew F. Davis <afd@ti.com>
Cc: Xu YiPing <xuyiping@hisilicon.com>
Cc: "Chenfeng (puck)" <puck.chen@hisilicon.com>
Cc: butao <butao@hisilicon.com>
Cc: "Xiaqing (A)" <saberlily.xia@hisilicon.com>
Cc: Yudongbin <yudongbin@hisilicon.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chenbo Feng <fengc@google.com>
Cc: Alistair Strachan <astrachan@google.com>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
v2:
* Switch allocate to return dmabuf fd
* Simplify init code
* Checkpatch fixups
* Droped dead system-contig code
v3:
* Whitespace fixups from Benjamin
* Make sure we're zeroing the allocated pages (from Liam)
* Use PAGE_ALIGN() consistently (suggested by Brian)
* Fold in new registration style from Andrew
* Avoid needless dynamic allocation of sys_heap (suggested by
  Christoph)
* Minor cleanups
* Folded in changes from Andrew to use simplified page list
  from the heap helpers
---
 drivers/dma-buf/Kconfig             |   2 +
 drivers/dma-buf/heaps/Kconfig       |   6 ++
 drivers/dma-buf/heaps/Makefile      |   1 +
 drivers/dma-buf/heaps/system_heap.c | 120 ++++++++++++++++++++++++++++++++++++
 4 files changed, 129 insertions(+)
 create mode 100644 drivers/dma-buf/heaps/Kconfig
 create mode 100644 drivers/dma-buf/heaps/system_heap.c

diff --git a/drivers/dma-buf/Kconfig b/drivers/dma-buf/Kconfig
index 09c61db..63c139d 100644
--- a/drivers/dma-buf/Kconfig
+++ b/drivers/dma-buf/Kconfig
@@ -47,4 +47,6 @@ menuconfig DMABUF_HEAPS
 	  this allows userspace to allocate dma-bufs that can be shared between
 	  drivers.
 
+source "drivers/dma-buf/heaps/Kconfig"
+
 endmenu
diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig
new file mode 100644
index 0000000..2050527
--- /dev/null
+++ b/drivers/dma-buf/heaps/Kconfig
@@ -0,0 +1,6 @@
+config DMABUF_HEAPS_SYSTEM
+	bool "DMA-BUF System Heap"
+	depends on DMABUF_HEAPS
+	help
+	  Choose this option to enable the system dmabuf heap. The system heap
+	  is backed by pages from the buddy allocator. If in doubt, say Y.
diff --git a/drivers/dma-buf/heaps/Makefile b/drivers/dma-buf/heaps/Makefile
index de49898..d1808ec 100644
--- a/drivers/dma-buf/heaps/Makefile
+++ b/drivers/dma-buf/heaps/Makefile
@@ -1,2 +1,3 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-y					+= heap-helpers.o
+obj-$(CONFIG_DMABUF_HEAPS_SYSTEM)	+= system_heap.o
diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c
new file mode 100644
index 0000000..f58ee3f
--- /dev/null
+++ b/drivers/dma-buf/heaps/system_heap.c
@@ -0,0 +1,120 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DMABUF System heap exporter
+ *
+ * Copyright (C) 2011 Google, Inc.
+ * Copyright (C) 2019 Linaro Ltd.
+ */
+
+#include <asm/page.h>
+#include <linux/dma-buf.h>
+#include <linux/dma-mapping.h>
+#include <linux/dma-heap.h>
+#include <linux/err.h>
+#include <linux/highmem.h>
+#include <linux/mm.h>
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+
+#include "heap-helpers.h"
+
+struct system_heap {
+	struct dma_heap *heap;
+} sys_heap;
+
+static void system_heap_free(struct heap_helper_buffer *buffer)
+{
+	pgoff_t pg;
+
+	for (pg = 0; pg < buffer->pagecount; pg++)
+		__free_page(buffer->pages[pg]);
+	kfree(buffer->pages);
+	kfree(buffer);
+}
+
+static int system_heap_allocate(struct dma_heap *heap,
+				unsigned long len,
+				unsigned long flags)
+{
+	struct heap_helper_buffer *helper_buffer;
+	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+	struct dma_buf *dmabuf;
+	int ret = -ENOMEM;
+	pgoff_t pg;
+
+	helper_buffer = kzalloc(sizeof(*helper_buffer), GFP_KERNEL);
+	if (!helper_buffer)
+		return -ENOMEM;
+
+	INIT_HEAP_HELPER_BUFFER(helper_buffer, system_heap_free);
+	helper_buffer->heap_buffer.flags = flags;
+	helper_buffer->heap_buffer.heap = heap;
+	helper_buffer->heap_buffer.size = len;
+
+	helper_buffer->pagecount = len / PAGE_SIZE;
+	helper_buffer->pages = kmalloc_array(helper_buffer->pagecount,
+					     sizeof(*helper_buffer->pages),
+					     GFP_KERNEL);
+	if (!helper_buffer->pages) {
+		ret = -ENOMEM;
+		goto err0;
+	}
+
+	for (pg = 0; pg < helper_buffer->pagecount; pg++) {
+		helper_buffer->pages[pg] = alloc_page(GFP_KERNEL | __GFP_ZERO);
+		if (!helper_buffer->pages[pg])
+			goto err1;
+	}
+
+	/* create the dmabuf */
+	exp_info.ops = &heap_helper_ops;
+	exp_info.size = len;
+	exp_info.flags = O_RDWR;
+	exp_info.priv = &helper_buffer->heap_buffer;
+	dmabuf = dma_buf_export(&exp_info);
+	if (IS_ERR(dmabuf)) {
+		ret = PTR_ERR(dmabuf);
+		goto err1;
+	}
+
+	helper_buffer->heap_buffer.dmabuf = dmabuf;
+
+	ret = dma_buf_fd(dmabuf, O_CLOEXEC);
+	if (ret < 0) {
+		dma_buf_put(dmabuf);
+		/* just return, as put will call release and that will free */
+		return ret;
+	}
+
+	return ret;
+
+err1:
+	while (pg > 0)
+		__free_page(helper_buffer->pages[--pg]);
+	kfree(helper_buffer->pages);
+err0:
+	kfree(helper_buffer);
+
+	return -ENOMEM;
+}
+
+static struct dma_heap_ops system_heap_ops = {
+	.allocate = system_heap_allocate,
+};
+
+static int system_heap_create(void)
+{
+	struct dma_heap_export_info exp_info;
+	int ret = 0;
+
+	exp_info.name = "system_heap";
+	exp_info.ops = &system_heap_ops;
+	exp_info.priv = &sys_heap;
+
+	sys_heap.heap = dma_heap_add(&exp_info);
+	if (IS_ERR(sys_heap.heap))
+		ret = PTR_ERR(sys_heap.heap);
+
+	return ret;
+}
+device_initcall(system_heap_create);
-- 
2.7.4

[RFC][PATCH 4/6 v3] dma-buf: heaps: Add CMA heap to dmabuf heapss

[John Stultz]

This adds a CMA heap, which allows userspace to allocate
a dma-buf of contiguous memory out of a CMA region.

This code is an evolution of the Android ION implementation, so
thanks to its original author and maintainters:
  Benjamin Gaignard, Laura Abbott, and others!

Cc: Laura Abbott <labbott@redhat.com>
Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Liam Mark <lmark@codeaurora.org>
Cc: Pratik Patel <pratikp@codeaurora.org>
Cc: Brian Starkey <Brian.Starkey@arm.com>
Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
Cc: Sudipto Paul <Sudipto.Paul@arm.com>
Cc: Andrew F. Davis <afd@ti.com>
Cc: Xu YiPing <xuyiping@hisilicon.com>
Cc: "Chenfeng (puck)" <puck.chen@hisilicon.com>
Cc: butao <butao@hisilicon.com>
Cc: "Xiaqing (A)" <saberlily.xia@hisilicon.com>
Cc: Yudongbin <yudongbin@hisilicon.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chenbo Feng <fengc@google.com>
Cc: Alistair Strachan <astrachan@google.com>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
v2:
* Switch allocate to return dmabuf fd
* Simplify init code
* Checkpatch fixups
v3:
* Switch to inline function for to_cma_heap()
* Minor cleanups suggested by Brian
* Fold in new registration style from Andrew
* Folded in changes from Andrew to use simplified page list
  from the heap helpers
---
 drivers/dma-buf/heaps/Kconfig    |   8 ++
 drivers/dma-buf/heaps/Makefile   |   1 +
 drivers/dma-buf/heaps/cma_heap.c | 170 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 179 insertions(+)
 create mode 100644 drivers/dma-buf/heaps/cma_heap.c

diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig
index 2050527..a5eef06 100644
--- a/drivers/dma-buf/heaps/Kconfig
+++ b/drivers/dma-buf/heaps/Kconfig
@@ -4,3 +4,11 @@ config DMABUF_HEAPS_SYSTEM
 	help
 	  Choose this option to enable the system dmabuf heap. The system heap
 	  is backed by pages from the buddy allocator. If in doubt, say Y.
+
+config DMABUF_HEAPS_CMA
+	bool "DMA-BUF CMA Heap"
+	depends on DMABUF_HEAPS && DMA_CMA
+	help
+	  Choose this option to enable dma-buf CMA heap. This heap is backed
+	  by the Contiguous Memory Allocator (CMA). If your system has these
+	  regions, you should say Y here.
diff --git a/drivers/dma-buf/heaps/Makefile b/drivers/dma-buf/heaps/Makefile
index d1808ec..6e54cde 100644
--- a/drivers/dma-buf/heaps/Makefile
+++ b/drivers/dma-buf/heaps/Makefile
@@ -1,3 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-y					+= heap-helpers.o
 obj-$(CONFIG_DMABUF_HEAPS_SYSTEM)	+= system_heap.o
+obj-$(CONFIG_DMABUF_HEAPS_CMA)		+= cma_heap.o
diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c
new file mode 100644
index 0000000..f4485c60
--- /dev/null
+++ b/drivers/dma-buf/heaps/cma_heap.c
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DMABUF CMA heap exporter
+ *
+ * Copyright (C) 2012, 2019 Linaro Ltd.
+ * Author: <benjamin.gaignard@linaro.org> for ST-Ericsson.
+ */
+
+#include <linux/device.h>
+#include <linux/dma-buf.h>
+#include <linux/dma-heap.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/cma.h>
+#include <linux/scatterlist.h>
+#include <linux/highmem.h>
+
+#include "heap-helpers.h"
+
+struct cma_heap {
+	struct dma_heap *heap;
+	struct cma *cma;
+};
+
+static void cma_heap_free(struct heap_helper_buffer *buffer)
+{
+	struct cma_heap *cma_heap = dma_heap_get_data(buffer->heap_buffer.heap);
+	struct page *pages = buffer->priv_virt;
+	unsigned long nr_pages;
+
+	nr_pages = buffer->heap_buffer.size >> PAGE_SHIFT;
+
+	/* free page list */
+	kfree(buffer->pages);
+	/* release memory */
+	cma_release(cma_heap->cma, pages, nr_pages);
+	kfree(buffer);
+}
+
+/* dmabuf heap CMA operations functions */
+static int cma_heap_allocate(struct dma_heap *heap,
+				unsigned long len,
+				unsigned long flags)
+{
+	struct cma_heap *cma_heap = dma_heap_get_data(heap);
+	struct heap_helper_buffer *helper_buffer;
+	struct page *pages;
+	size_t size = PAGE_ALIGN(len);
+	unsigned long nr_pages = size >> PAGE_SHIFT;
+	unsigned long align = get_order(size);
+	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+	struct dma_buf *dmabuf;
+	int ret = -ENOMEM;
+	pgoff_t pg;
+
+	if (align > CONFIG_CMA_ALIGNMENT)
+		align = CONFIG_CMA_ALIGNMENT;
+
+	helper_buffer = kzalloc(sizeof(*helper_buffer), GFP_KERNEL);
+	if (!helper_buffer)
+		return -ENOMEM;
+
+	INIT_HEAP_HELPER_BUFFER(helper_buffer, cma_heap_free);
+	helper_buffer->heap_buffer.flags = flags;
+	helper_buffer->heap_buffer.heap = heap;
+	helper_buffer->heap_buffer.size = len;
+
+	pages = cma_alloc(cma_heap->cma, nr_pages, align, false);
+	if (!pages)
+		goto free_buf;
+
+	if (PageHighMem(pages)) {
+		unsigned long nr_clear_pages = nr_pages;
+		struct page *page = pages;
+
+		while (nr_clear_pages > 0) {
+			void *vaddr = kmap_atomic(page);
+
+			memset(vaddr, 0, PAGE_SIZE);
+			kunmap_atomic(vaddr);
+			page++;
+			nr_clear_pages--;
+		}
+	} else {
+		memset(page_address(pages), 0, size);
+	}
+
+	helper_buffer->pagecount = nr_pages;
+	helper_buffer->pages = kmalloc_array(helper_buffer->pagecount,
+					     sizeof(*helper_buffer->pages),
+					     GFP_KERNEL);
+	if (!helper_buffer->pages) {
+		ret = -ENOMEM;
+		goto free_cma;
+	}
+
+	for (pg = 0; pg < helper_buffer->pagecount; pg++) {
+		helper_buffer->pages[pg] = &pages[pg];
+		if (!helper_buffer->pages[pg])
+			goto free_pages;
+	}
+
+	/* create the dmabuf */
+	exp_info.ops = &heap_helper_ops;
+	exp_info.size = len;
+	exp_info.flags = O_RDWR;
+	exp_info.priv = &helper_buffer->heap_buffer;
+	dmabuf = dma_buf_export(&exp_info);
+	if (IS_ERR(dmabuf)) {
+		ret = PTR_ERR(dmabuf);
+		goto free_pages;
+	}
+
+	helper_buffer->heap_buffer.dmabuf = dmabuf;
+	helper_buffer->priv_virt = pages;
+
+	ret = dma_buf_fd(dmabuf, O_CLOEXEC);
+	if (ret < 0) {
+		dma_buf_put(dmabuf);
+		/* just return, as put will call release and that will free */
+		return ret;
+	}
+
+	return ret;
+
+free_pages:
+	kfree(helper_buffer->pages);
+free_cma:
+	cma_release(cma_heap->cma, pages, nr_pages);
+free_buf:
+	kfree(helper_buffer);
+	return ret;
+}
+
+static struct dma_heap_ops cma_heap_ops = {
+	.allocate = cma_heap_allocate,
+};
+
+static int __add_cma_heap(struct cma *cma, void *data)
+{
+	struct cma_heap *cma_heap;
+	struct dma_heap_export_info exp_info;
+
+	cma_heap = kzalloc(sizeof(*cma_heap), GFP_KERNEL);
+	if (!cma_heap)
+		return -ENOMEM;
+	cma_heap->cma = cma;
+
+	exp_info.name = cma_get_name(cma);
+	exp_info.ops = &cma_heap_ops;
+	exp_info.priv = cma_heap;
+
+	cma_heap->heap = dma_heap_add(&exp_info);
+	if (IS_ERR(cma_heap->heap)) {
+		int ret = PTR_ERR(cma_heap->heap);
+
+		kfree(cma_heap);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int add_cma_heaps(void)
+{
+	cma_for_each_area(__add_cma_heap, NULL);
+	return 0;
+}
+device_initcall(add_cma_heaps);
-- 
2.7.4

[RFC][PATCH 5/6 v3] dma-buf: Add Dummy Importer Test Device

[John Stultz]

From: "Andrew F. Davis" <afd@ti.com>

This dummy test driver lets us do some very basic testing of
importing dma-bufs.

It is based originally on TI's out of tree "DMA-BUF physical
address user-space exporter" originally by
Andrew F. Davis <afd@ti.com>

Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Liam Mark <lmark@codeaurora.org>
Cc: Pratik Patel <pratikp@codeaurora.org>
Cc: Brian Starkey <Brian.Starkey@arm.com>
Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
Cc: Sudipto Paul <Sudipto.Paul@arm.com>
Cc: Andrew F. Davis <afd@ti.com>
Cc: Xu YiPing <xuyiping@hisilicon.com>
Cc: "Chenfeng (puck)" <puck.chen@hisilicon.com>
Cc: butao <butao@hisilicon.com>
Cc: "Xiaqing (A)" <saberlily.xia@hisilicon.com>
Cc: Yudongbin <yudongbin@hisilicon.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chenbo Feng <fengc@google.com>
Cc: Alistair Strachan <astrachan@google.com>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Andrew F. Davis <afd@ti.com>
[Renamed and refactored dma_buf_phys driver, rewote commitlog]
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
 drivers/dma-buf/Kconfig              |   6 +
 drivers/dma-buf/Makefile             |   1 +
 drivers/dma-buf/dma-buf-testdev.c    | 239 +++++++++++++++++++++++++++++++++++
 include/uapi/linux/dma-buf-testdev.h |  37 ++++++
 4 files changed, 283 insertions(+)
 create mode 100644 drivers/dma-buf/dma-buf-testdev.c
 create mode 100644 include/uapi/linux/dma-buf-testdev.h

diff --git a/drivers/dma-buf/Kconfig b/drivers/dma-buf/Kconfig
index 63c139d..3cbcbe0 100644
--- a/drivers/dma-buf/Kconfig
+++ b/drivers/dma-buf/Kconfig
@@ -49,4 +49,10 @@ menuconfig DMABUF_HEAPS
 
 source "drivers/dma-buf/heaps/Kconfig"
 
+config DMABUF_TESTDEV
+	bool "DMA-BUF Dummy Test Device"
+	depends on DMA_SHARED_BUFFER
+	help
+	  This provides a dummy test device that can be used to test
+	  importing dma-bufs.
 endmenu
diff --git a/drivers/dma-buf/Makefile b/drivers/dma-buf/Makefile
index 09c2f2d..69bf45d 100644
--- a/drivers/dma-buf/Makefile
+++ b/drivers/dma-buf/Makefile
@@ -4,3 +4,4 @@ obj-$(CONFIG_DMABUF_HEAPS)	+= dma-heap.o
 obj-$(CONFIG_SYNC_FILE)		+= sync_file.o
 obj-$(CONFIG_SW_SYNC)		+= sw_sync.o sync_debug.o
 obj-$(CONFIG_UDMABUF)		+= udmabuf.o
+obj-$(CONFIG_DMABUF_TESTDEV)	+= dma-buf-testdev.o
diff --git a/drivers/dma-buf/dma-buf-testdev.c b/drivers/dma-buf/dma-buf-testdev.c
new file mode 100644
index 0000000..dc3ed93
--- /dev/null
+++ b/drivers/dma-buf/dma-buf-testdev.c
@@ -0,0 +1,239 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DMA-BUF Dummy Importer Test Device
+ *
+ * Originally from TI DMA BUF contiguous buffer physical address
+ * user-space exporter
+ *
+ * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
+ *	Andrew F. Davis <afd@ti.com>
+ */
+
+#include <linux/device.h>
+#include <linux/dma-buf.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+
+#include <uapi/linux/dma-buf-testdev.h>
+
+#define DEVICE_NAME "dma-buf-testdev"
+
+struct dma_buf_testdev_priv {
+	struct miscdevice miscdev;
+};
+
+struct dma_buf_testdev_file {
+	struct device *dev;
+	struct dma_buf *dma_buf;
+	struct dma_buf_attachment *attachment;
+	struct sg_table *sgt;
+};
+
+static int dma_buf_testdev_open(struct inode *inode, struct file *file)
+{
+	struct miscdevice *miscdev = file->private_data;
+	struct device *dev = miscdev->this_device;
+	struct dma_buf_testdev_file *priv;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+	priv->dev = dev;
+	file->private_data = (void *)priv;
+
+	return 0;
+}
+
+static int dma_buf_testdev_release(struct inode *inode, struct file *file)
+{
+	struct dma_buf_testdev_file *priv = file->private_data;
+
+	if (priv->attachment && priv->sgt)
+		dma_buf_unmap_attachment(priv->attachment, priv->sgt,
+					 DMA_BIDIRECTIONAL);
+	if (priv->dma_buf && priv->attachment)
+		dma_buf_detach(priv->dma_buf, priv->attachment);
+	if (priv->dma_buf)
+		dma_buf_put(priv->dma_buf);
+
+	kfree(priv);
+
+	return 0;
+}
+
+static int dma_buf_testdev_convert(struct dma_buf_testdev_file *priv, int fd,
+				   phys_addr_t *phys)
+{
+	struct device *dev = priv->dev;
+	struct dma_buf *dma_buf;
+	struct dma_buf_attachment *attachment;
+	struct sg_table *sgt;
+	dma_addr_t dma_addr;
+	int ret;
+
+	dma_buf = dma_buf_get(fd);
+	if (IS_ERR(dma_buf))
+		return PTR_ERR(dma_buf);
+
+	/* Attach as the parent device as it will have the correct DMA ops */
+	attachment = dma_buf_attach(dma_buf, dev->parent);
+	if (IS_ERR(attachment)) {
+		ret = PTR_ERR(attachment);
+		goto fail_put;
+	}
+
+	sgt = dma_buf_map_attachment(attachment, DMA_BIDIRECTIONAL);
+	if (IS_ERR(sgt)) {
+		ret = PTR_ERR(sgt);
+		goto fail_detach;
+	}
+
+	/* Without PAT only physically contiguous buffers can be supported */
+	if (sgt->orig_nents != 1) {
+		dev_err(dev, "DMA-BUF not contiguous\n");
+		ret = -EINVAL;
+		goto fail_unmap;
+	}
+
+	dma_addr = sg_dma_address(sgt->sgl);
+
+	*phys = dma_addr;
+
+	priv->dma_buf = dma_buf;
+	priv->attachment = attachment;
+	priv->sgt = sgt;
+
+	return 0;
+
+fail_unmap:
+	dma_buf_unmap_attachment(attachment, sgt, DMA_BIDIRECTIONAL);
+fail_detach:
+	dma_buf_detach(dma_buf, attachment);
+fail_put:
+	dma_buf_put(dma_buf);
+
+	return ret;
+}
+
+static long dma_buf_testdev_ioctl(struct file *file, unsigned int cmd,
+				  unsigned long arg)
+{
+	struct dma_buf_testdev_file *priv = file->private_data;
+
+	switch (cmd) {
+	case DMA_BUF_TESTDEV_IOC_CONVERT:
+	{
+		struct dma_buf_testdev_data data;
+		int ret;
+
+		/*
+		 * TODO: this should likely be properly serialized, but I
+		 * see no reason this file would ever need to be shared.
+		 */
+		/* one attachment per file */
+		if (priv->dma_buf)
+			return -EFAULT;
+
+		if (copy_from_user(&data, (void __user *)arg, _IOC_SIZE(cmd)))
+			return -EFAULT;
+
+		ret = dma_buf_testdev_convert(priv, data.fd, &data.phys);
+		if (ret)
+			return ret;
+
+		if (copy_to_user((void __user *)arg, &data, _IOC_SIZE(cmd)))
+			return -EFAULT;
+
+		break;
+	}
+	default:
+		return -ENOTTY;
+	}
+
+	return 0;
+}
+
+static const struct file_operations dma_buf_testdev_fops = {
+	.owner = THIS_MODULE,
+	.open = dma_buf_testdev_open,
+	.release = dma_buf_testdev_release,
+	.unlocked_ioctl = dma_buf_testdev_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= dma_buf_testdev_ioctl,
+#endif
+};
+
+static int dma_buf_testdev_probe(struct platform_device *pdev)
+{
+	struct dma_buf_testdev_priv *priv;
+	struct device *dev = &pdev->dev;
+	int err;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+	dev_set_drvdata(dev, priv);
+
+	dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
+
+	if (!dev->dma_parms) {
+		dev->dma_parms = devm_kzalloc(dev, sizeof(*dev->dma_parms),
+					      GFP_KERNEL);
+		if (!dev->dma_parms)
+			return -ENOMEM;
+	}
+	dma_set_max_seg_size(dev, DMA_BIT_MASK(32));
+
+	priv->miscdev.minor = MISC_DYNAMIC_MINOR;
+	priv->miscdev.name = devm_kasprintf(dev, GFP_KERNEL, "%s",
+					    DEVICE_NAME);
+	priv->miscdev.fops = &dma_buf_testdev_fops;
+	priv->miscdev.parent = dev;
+	err = misc_register(&priv->miscdev);
+	if (err) {
+		dev_err(dev,
+			"unable to register DMA-BUF to Phys misc device\n");
+		return err;
+	}
+
+	return 0;
+}
+
+static int dma_buf_testdev_remove(struct platform_device *pdev)
+{
+	struct dma_buf_testdev_priv *priv = dev_get_drvdata(&pdev->dev);
+
+	misc_deregister(&priv->miscdev);
+
+	return 0;
+}
+
+static struct platform_driver dma_buf_testdev_driver = {
+	.probe = dma_buf_testdev_probe,
+	.remove = dma_buf_testdev_remove,
+	.driver = {
+		.name = "dma_buf_testdev",
+	}
+};
+module_platform_driver(dma_buf_testdev_driver);
+
+static int __init dma_buf_testdev_init(void)
+{
+	struct platform_device *pdev;
+
+	pdev = platform_device_register_simple("dma_buf_testdev", -1, NULL, 0);
+
+	return PTR_ERR_OR_ZERO(pdev);
+}
+
+postcore_initcall(dma_buf_testdev_init);
+
+MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
+MODULE_DESCRIPTION("DMA-BUF Dummy Importer Test Device");
+MODULE_LICENSE("GPL v2");
diff --git a/include/uapi/linux/dma-buf-testdev.h b/include/uapi/linux/dma-buf-testdev.h
new file mode 100644
index 0000000..b9706b8
--- /dev/null
+++ b/include/uapi/linux/dma-buf-testdev.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * DMA-BUF Dummy Importer Test Device
+ *
+ * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
+ *	Andrew F. Davis <afd@ti.com>
+ */
+
+#ifndef DMA_BUF_TESTDEV_H
+#define DMA_BUF_TESTDEV_H
+
+#include <linux/ioctl.h>
+#include <linux/types.h>
+
+/**
+ * struct dma_buf_testdev_data - metadata passed from userspace for conversion
+ * @fd:		DMA-BUF fd for conversion
+ * @phys:	populated with CPU physical address of DMA-BUF
+ */
+struct dma_buf_testdev_data {
+	__u32 fd;
+	__u64 phys;
+};
+
+#define DMA_BUF_TESTDEV_IOC_MAGIC 'D'
+
+/**
+ * DOC: DMA_BUF_TESTDEV_IOC_CONVERT - Convert DMA-BUF to physical address
+ *
+ * Takes a dma_buf_testdev_data struct containing a fd for a
+ * physicaly contigous buffer. Pins this buffer and populates
+ * phys field with the CPU physical address.
+ */
+#define DMA_BUF_TESTDEV_IOC_CONVERT _IOWR(DMA_BUF_TESTDEV_IOC_MAGIC, 0, \
+					  struct dma_buf_testdev_data)
+
+#endif /* DMA_BUF_PHYS_H */
-- 
2.7.4

[RFC][PATCH 5/6 v3] dma-buf: Add Dummy Importer Test Device

[John Stultz]

From: "Andrew F. Davis" <afd@ti.com>

This dummy test driver lets us do some very basic testing of
importing dma-bufs.

It is based originally on TI's out of tree "DMA-BUF physical
address user-space exporter" originally by
Andrew F. Davis <afd@ti.com>

Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Liam Mark <lmark@codeaurora.org>
Cc: Pratik Patel <pratikp@codeaurora.org>
Cc: Brian Starkey <Brian.Starkey@arm.com>
Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
Cc: Sudipto Paul <Sudipto.Paul@arm.com>
Cc: Andrew F. Davis <afd@ti.com>
Cc: Xu YiPing <xuyiping@hisilicon.com>
Cc: "Chenfeng (puck)" <puck.chen@hisilicon.com>
Cc: butao <butao@hisilicon.com>
Cc: "Xiaqing (A)" <saberlily.xia@hisilicon.com>
Cc: Yudongbin <yudongbin@hisilicon.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chenbo Feng <fengc@google.com>
Cc: Alistair Strachan <astrachan@google.com>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Andrew F. Davis <afd@ti.com>
[Renamed and refactored dma_buf_phys driver, rewote commitlog]
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
 drivers/dma-buf/Kconfig              |   6 +
 drivers/dma-buf/Makefile             |   1 +
 drivers/dma-buf/dma-buf-testdev.c    | 239 +++++++++++++++++++++++++++++++++++
 include/uapi/linux/dma-buf-testdev.h |  37 ++++++
 4 files changed, 283 insertions(+)
 create mode 100644 drivers/dma-buf/dma-buf-testdev.c
 create mode 100644 include/uapi/linux/dma-buf-testdev.h

diff --git a/drivers/dma-buf/Kconfig b/drivers/dma-buf/Kconfig
index 63c139d..3cbcbe0 100644
--- a/drivers/dma-buf/Kconfig
+++ b/drivers/dma-buf/Kconfig
@@ -49,4 +49,10 @@ menuconfig DMABUF_HEAPS
 
 source "drivers/dma-buf/heaps/Kconfig"
 
+config DMABUF_TESTDEV
+	bool "DMA-BUF Dummy Test Device"
+	depends on DMA_SHARED_BUFFER
+	help
+	  This provides a dummy test device that can be used to test
+	  importing dma-bufs.
 endmenu
diff --git a/drivers/dma-buf/Makefile b/drivers/dma-buf/Makefile
index 09c2f2d..69bf45d 100644
--- a/drivers/dma-buf/Makefile
+++ b/drivers/dma-buf/Makefile
@@ -4,3 +4,4 @@ obj-$(CONFIG_DMABUF_HEAPS)	+= dma-heap.o
 obj-$(CONFIG_SYNC_FILE)		+= sync_file.o
 obj-$(CONFIG_SW_SYNC)		+= sw_sync.o sync_debug.o
 obj-$(CONFIG_UDMABUF)		+= udmabuf.o
+obj-$(CONFIG_DMABUF_TESTDEV)	+= dma-buf-testdev.o
diff --git a/drivers/dma-buf/dma-buf-testdev.c b/drivers/dma-buf/dma-buf-testdev.c
new file mode 100644
index 0000000..dc3ed93
--- /dev/null
+++ b/drivers/dma-buf/dma-buf-testdev.c
@@ -0,0 +1,239 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DMA-BUF Dummy Importer Test Device
+ *
+ * Originally from TI DMA BUF contiguous buffer physical address
+ * user-space exporter
+ *
+ * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
+ *	Andrew F. Davis <afd@ti.com>
+ */
+
+#include <linux/device.h>
+#include <linux/dma-buf.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+
+#include <uapi/linux/dma-buf-testdev.h>
+
+#define DEVICE_NAME "dma-buf-testdev"
+
+struct dma_buf_testdev_priv {
+	struct miscdevice miscdev;
+};
+
+struct dma_buf_testdev_file {
+	struct device *dev;
+	struct dma_buf *dma_buf;
+	struct dma_buf_attachment *attachment;
+	struct sg_table *sgt;
+};
+
+static int dma_buf_testdev_open(struct inode *inode, struct file *file)
+{
+	struct miscdevice *miscdev = file->private_data;
+	struct device *dev = miscdev->this_device;
+	struct dma_buf_testdev_file *priv;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+	priv->dev = dev;
+	file->private_data = (void *)priv;
+
+	return 0;
+}
+
+static int dma_buf_testdev_release(struct inode *inode, struct file *file)
+{
+	struct dma_buf_testdev_file *priv = file->private_data;
+
+	if (priv->attachment && priv->sgt)
+		dma_buf_unmap_attachment(priv->attachment, priv->sgt,
+					 DMA_BIDIRECTIONAL);
+	if (priv->dma_buf && priv->attachment)
+		dma_buf_detach(priv->dma_buf, priv->attachment);
+	if (priv->dma_buf)
+		dma_buf_put(priv->dma_buf);
+
+	kfree(priv);
+
+	return 0;
+}
+
+static int dma_buf_testdev_convert(struct dma_buf_testdev_file *priv, int fd,
+				   phys_addr_t *phys)
+{
+	struct device *dev = priv->dev;
+	struct dma_buf *dma_buf;
+	struct dma_buf_attachment *attachment;
+	struct sg_table *sgt;
+	dma_addr_t dma_addr;
+	int ret;
+
+	dma_buf = dma_buf_get(fd);
+	if (IS_ERR(dma_buf))
+		return PTR_ERR(dma_buf);
+
+	/* Attach as the parent device as it will have the correct DMA ops */
+	attachment = dma_buf_attach(dma_buf, dev->parent);
+	if (IS_ERR(attachment)) {
+		ret = PTR_ERR(attachment);
+		goto fail_put;
+	}
+
+	sgt = dma_buf_map_attachment(attachment, DMA_BIDIRECTIONAL);
+	if (IS_ERR(sgt)) {
+		ret = PTR_ERR(sgt);
+		goto fail_detach;
+	}
+
+	/* Without PAT only physically contiguous buffers can be supported */
+	if (sgt->orig_nents != 1) {
+		dev_err(dev, "DMA-BUF not contiguous\n");
+		ret = -EINVAL;
+		goto fail_unmap;
+	}
+
+	dma_addr = sg_dma_address(sgt->sgl);
+
+	*phys = dma_addr;
+
+	priv->dma_buf = dma_buf;
+	priv->attachment = attachment;
+	priv->sgt = sgt;
+
+	return 0;
+
+fail_unmap:
+	dma_buf_unmap_attachment(attachment, sgt, DMA_BIDIRECTIONAL);
+fail_detach:
+	dma_buf_detach(dma_buf, attachment);
+fail_put:
+	dma_buf_put(dma_buf);
+
+	return ret;
+}
+
+static long dma_buf_testdev_ioctl(struct file *file, unsigned int cmd,
+				  unsigned long arg)
+{
+	struct dma_buf_testdev_file *priv = file->private_data;
+
+	switch (cmd) {
+	case DMA_BUF_TESTDEV_IOC_CONVERT:
+	{
+		struct dma_buf_testdev_data data;
+		int ret;
+
+		/*
+		 * TODO: this should likely be properly serialized, but I
+		 * see no reason this file would ever need to be shared.
+		 */
+		/* one attachment per file */
+		if (priv->dma_buf)
+			return -EFAULT;
+
+		if (copy_from_user(&data, (void __user *)arg, _IOC_SIZE(cmd)))
+			return -EFAULT;
+
+		ret = dma_buf_testdev_convert(priv, data.fd, &data.phys);
+		if (ret)
+			return ret;
+
+		if (copy_to_user((void __user *)arg, &data, _IOC_SIZE(cmd)))
+			return -EFAULT;
+
+		break;
+	}
+	default:
+		return -ENOTTY;
+	}
+
+	return 0;
+}
+
+static const struct file_operations dma_buf_testdev_fops = {
+	.owner = THIS_MODULE,
+	.open = dma_buf_testdev_open,
+	.release = dma_buf_testdev_release,
+	.unlocked_ioctl = dma_buf_testdev_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= dma_buf_testdev_ioctl,
+#endif
+};
+
+static int dma_buf_testdev_probe(struct platform_device *pdev)
+{
+	struct dma_buf_testdev_priv *priv;
+	struct device *dev = &pdev->dev;
+	int err;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+	dev_set_drvdata(dev, priv);
+
+	dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
+
+	if (!dev->dma_parms) {
+		dev->dma_parms = devm_kzalloc(dev, sizeof(*dev->dma_parms),
+					      GFP_KERNEL);
+		if (!dev->dma_parms)
+			return -ENOMEM;
+	}
+	dma_set_max_seg_size(dev, DMA_BIT_MASK(32));
+
+	priv->miscdev.minor = MISC_DYNAMIC_MINOR;
+	priv->miscdev.name = devm_kasprintf(dev, GFP_KERNEL, "%s",
+					    DEVICE_NAME);
+	priv->miscdev.fops = &dma_buf_testdev_fops;
+	priv->miscdev.parent = dev;
+	err = misc_register(&priv->miscdev);
+	if (err) {
+		dev_err(dev,
+			"unable to register DMA-BUF to Phys misc device\n");
+		return err;
+	}
+
+	return 0;
+}
+
+static int dma_buf_testdev_remove(struct platform_device *pdev)
+{
+	struct dma_buf_testdev_priv *priv = dev_get_drvdata(&pdev->dev);
+
+	misc_deregister(&priv->miscdev);
+
+	return 0;
+}
+
+static struct platform_driver dma_buf_testdev_driver = {
+	.probe = dma_buf_testdev_probe,
+	.remove = dma_buf_testdev_remove,
+	.driver = {
+		.name = "dma_buf_testdev",
+	}
+};
+module_platform_driver(dma_buf_testdev_driver);
+
+static int __init dma_buf_testdev_init(void)
+{
+	struct platform_device *pdev;
+
+	pdev = platform_device_register_simple("dma_buf_testdev", -1, NULL, 0);
+
+	return PTR_ERR_OR_ZERO(pdev);
+}
+
+postcore_initcall(dma_buf_testdev_init);
+
+MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
+MODULE_DESCRIPTION("DMA-BUF Dummy Importer Test Device");
+MODULE_LICENSE("GPL v2");
diff --git a/include/uapi/linux/dma-buf-testdev.h b/include/uapi/linux/dma-buf-testdev.h
new file mode 100644
index 0000000..b9706b8
--- /dev/null
+++ b/include/uapi/linux/dma-buf-testdev.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * DMA-BUF Dummy Importer Test Device
+ *
+ * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
+ *	Andrew F. Davis <afd@ti.com>
+ */
+
+#ifndef DMA_BUF_TESTDEV_H
+#define DMA_BUF_TESTDEV_H
+
+#include <linux/ioctl.h>
+#include <linux/types.h>
+
+/**
+ * struct dma_buf_testdev_data - metadata passed from userspace for conversion
+ * @fd:		DMA-BUF fd for conversion
+ * @phys:	populated with CPU physical address of DMA-BUF
+ */
+struct dma_buf_testdev_data {
+	__u32 fd;
+	__u64 phys;
+};
+
+#define DMA_BUF_TESTDEV_IOC_MAGIC 'D'
+
+/**
+ * DOC: DMA_BUF_TESTDEV_IOC_CONVERT - Convert DMA-BUF to physical address
+ *
+ * Takes a dma_buf_testdev_data struct containing a fd for a
+ * physicaly contigous buffer. Pins this buffer and populates
+ * phys field with the CPU physical address.
+ */
+#define DMA_BUF_TESTDEV_IOC_CONVERT _IOWR(DMA_BUF_TESTDEV_IOC_MAGIC, 0, \
+					  struct dma_buf_testdev_data)
+
+#endif /* DMA_BUF_PHYS_H */
-- 
2.7.4

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

[RFC][PATCH 6/6 v3] kselftests: Add dma-heap test

[John Stultz]

Add very trivial allocation and import test for dma-heaps.

TODO: Still needs improvements

Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Liam Mark <lmark@codeaurora.org>
Cc: Pratik Patel <pratikp@codeaurora.org>
Cc: Brian Starkey <Brian.Starkey@arm.com>
Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
Cc: Sudipto Paul <Sudipto.Paul@arm.com>
Cc: Andrew F. Davis <afd@ti.com>
Cc: Xu YiPing <xuyiping@hisilicon.com>
Cc: "Chenfeng (puck)" <puck.chen@hisilicon.com>
Cc: butao <butao@hisilicon.com>
Cc: "Xiaqing (A)" <saberlily.xia@hisilicon.com>
Cc: Yudongbin <yudongbin@hisilicon.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chenbo Feng <fengc@google.com>
Cc: Alistair Strachan <astrachan@google.com>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
v2: Switched to use reworked dma-heap apis

v3:
* Add simple mmap
* Utilize dma-buf testdev to test importing
---
 tools/testing/selftests/dmabuf-heaps/Makefile      |  11 ++
 tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c | 169 +++++++++++++++++++++
 2 files changed, 180 insertions(+)
 create mode 100644 tools/testing/selftests/dmabuf-heaps/Makefile
 create mode 100644 tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c

diff --git a/tools/testing/selftests/dmabuf-heaps/Makefile b/tools/testing/selftests/dmabuf-heaps/Makefile
new file mode 100644
index 0000000..c414ad3
--- /dev/null
+++ b/tools/testing/selftests/dmabuf-heaps/Makefile
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-2.0
+CFLAGS += -static -O3 -Wl,-no-as-needed -Wall
+#LDLIBS += -lrt -lpthread -lm
+
+# these are all "safe" tests that don't modify
+# system time or require escalated privileges
+TEST_GEN_PROGS = dmabuf-heap
+
+
+include ../lib.mk
+
diff --git a/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c b/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c
new file mode 100644
index 0000000..df30465
--- /dev/null
+++ b/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c
@@ -0,0 +1,169 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+
+#include "../../../../include/uapi/linux/dma-heap.h"
+#include "../../../../include/uapi/linux/dma-buf-testdev.h"
+
+#define DEVPATH "/dev/dma_heap"
+
+int dmabuf_importer_open(char *name)
+{
+	int ret, fd;
+	char buf[256];
+
+	ret = sprintf(buf, "/dev/%s", name);
+	if (ret < 0) {
+		printf("sprintf failed!\n");
+		return ret;
+	}
+
+	fd = open(buf, O_RDWR);
+	if (fd < 0)
+		printf("open %s failed!\n", buf);
+	return fd;
+}
+
+int dmabuf_importer_import(int importer_fd,  int dmabuf_fd, void *phys_addr)
+{
+	struct dma_buf_testdev_data data =  {
+		.fd = dmabuf_fd,
+		.phys = 0,
+	};
+
+	int ret;
+
+	if (phys_addr == NULL)
+		return -EINVAL;
+
+	ret = ioctl(importer_fd, DMA_BUF_TESTDEV_IOC_CONVERT, &data);
+	if (ret < 0)
+		return ret;
+
+	*(__u64 *)phys_addr = data.phys;
+
+	return ret;
+}
+
+
+int dmabuf_heap_open(char *name)
+{
+	int ret, fd;
+	char buf[256];
+
+	ret = sprintf(buf, "%s/%s", DEVPATH, name);
+	if (ret < 0) {
+		printf("sprintf failed!\n");
+		return ret;
+	}
+
+	fd = open(buf, O_RDWR);
+	if (fd < 0)
+		printf("open %s failed!\n", buf);
+	return fd;
+}
+
+int dmabuf_heap_alloc(int fd, size_t len, unsigned int flags, int *dmabuf_fd)
+{
+	struct dma_heap_allocation_data data = {
+		.len = len,
+		.flags = flags,
+	};
+	int ret;
+
+	if (dmabuf_fd == NULL)
+		return -EINVAL;
+
+	ret = ioctl(fd, DMA_HEAP_IOC_ALLOC, &data);
+	if (ret < 0)
+		return ret;
+	*dmabuf_fd = (int)data.fd;
+	return ret;
+}
+
+#define ONE_MEG (1024*1024)
+
+void do_test(char *heap_name)
+{
+	int heap_fd = -1, dmabuf_fd = -1, importer_fd = -1;
+	void *p;
+	int ret;
+	long phys;
+
+	printf("Testing heap: %s\n", heap_name);
+
+	heap_fd = dmabuf_heap_open(heap_name);
+	if (heap_fd < 0)
+		return;
+
+	printf("Allocating 1 MEG\n");
+	ret = dmabuf_heap_alloc(heap_fd, ONE_MEG, 0, &dmabuf_fd);
+	if (ret)
+		goto out;
+
+
+	/* mmap and write a simple pattern */
+	p = mmap(NULL,
+		 ONE_MEG,
+		 PROT_READ | PROT_WRITE,
+		 MAP_SHARED,
+		 dmabuf_fd,
+		 0);
+	if (p == MAP_FAILED) {
+		printf("mmap() failed: %m\n");
+		abort();
+	}
+	printf("mmap passed\n");
+
+	memset(p, 1, ONE_MEG/2);
+	p = (char *)p + ONE_MEG/2;
+	memset(p, 0, ONE_MEG/2);
+	munmap(p, ONE_MEG);
+
+
+	importer_fd = dmabuf_importer_open("dma-buf-testdev");
+
+	ret = dmabuf_importer_import(importer_fd, dmabuf_fd, &phys);
+	if (ret) {
+		printf("Error importing to test device!\n");
+		goto out;
+	}
+	printf("Import passed!\n");
+
+	/* DO SOMETHING WITH THE DMABUF HERE? */
+
+out:
+	if (importer_fd >= 0)
+		close(importer_fd);
+	if (dmabuf_fd >= 0)
+		close(dmabuf_fd);
+	if (heap_fd >= 0)
+		close(heap_fd);
+}
+
+
+int main(void)
+{
+	DIR *d;
+	struct dirent *dir;
+
+	d = opendir(DEVPATH);
+	if (!d) {
+		printf("No %s directory?\n", DEVPATH);
+		return -1;
+	}
+
+	while ((dir = readdir(d)) != NULL)
+		do_test(dir->d_name);
+
+	return 0;
+}
-- 
2.7.4

Re: [RFC][PATCH 0/6 v3] DMA-BUF Heaps (destaging ION)

[Andrew F. Davis]

On 3/28/19 7:15 PM, John Stultz wrote:
> Here is another RFC of the dma-buf heaps patchset Andrew and I
> have been working on which tries to destage a fair chunk of ION
> functionality.
> 
> The patchset implements per-heap devices which can be opened
> directly and then an ioctl is used to allocate a dmabuf from the
> heap.
> 
> The interface is similar, but much simpler then IONs, only
> providing an ALLOC ioctl.
> 
> Also, I've provided simple system and cma heaps. The system
> heap in particular is missing the page-pool optimizations ION
> had, but works well enough to validate the interface.
> 
> I've booted and tested these patches with AOSP on the HiKey960
> using the kernel tree here:
>   https://git.linaro.org/people/john.stultz/android-dev.git/log/?h=dev/dma-buf-heap
> 
> And the userspace changes here:
>   https://android-review.googlesource.com/c/device/linaro/hikey/+/909436
> 
> 
> Compared to ION, this patchset is missing the system-contig,
> carveout and chunk heaps, as I don't have a device that uses
> those, so I'm unable to do much useful validation there.
> Additionally we have no upstream users of chunk or carveout,
> and the system-contig has been deprecated in the common/andoid-*
> kernels, so this should be ok.
> 


I'd like to go over my use-cases for a moment to see if we can get some
agreement on what to do with the carveout/chunk heaps.

We used DRM (omapdrm) to get buffers for display, GPU, and multi-media.
Our out-of-tree CMEM driver[0] for remote processing (OpenCL/CV/VX)
buffers. And for secure heaps we use what are basically slightly
modified ION carveout heaps.

Now with the DMA-Heap framework what we can do is for sub-systems with
IOMMUs use 'system' heap (GPU). For those that need contiguous memory
(display, MM) we have 'cma' heap (and maybe 'system-contig' at some
point). For our SRAM areas used in remote processing I've posted an RFC
for a heap[1] to provide allocations from those areas.

The above leaves one last gap for us, uncached/unmapped areas from
regular memory. I propose this is where we use the 'carveout' heap.
Right now to get some contiguous/cached memory with DT you can:

reserved-memory {
	[...]
	cma_memory {
		compatible = "shared-dma-pool";
		reg = <0x79000000 0x400000>;
		reusable;
	};

	coherent_memory@78000000 {
		reg = <0x78000000 0x800000>;
		no-map;
	};
};

'cma_memory' will show up as a 'cma' heap, so all good there.

Looking at 'coherent_memory' it will not have valid backing 'struct
page' and so cannot be given cached mappings as the standard dma memory
ops would fail. This would give this area the right properties for both
users who don't want to do all the cache maintenance ops (Liam?) and for
secure heaps that have restrictions on access from Linux running CPU.

The question then is how to mark these areas for export with DMA-Heaps?
Maybe a cma_for_each_area() like function but for dma coherent areas?

Anyway for now this is not super important and I can post a patchset at
some later point for this when I get it working and tested internally.

[0]
http://software-dl.ti.com/processor-sdk-linux/esd/docs/latest/linux/Foundational_Components_CMEM.html
[1] https://patchwork.kernel.org/patch/10863957/

Thanks,
Andrew


> I've also removed the stats accounting for now, since it should
> be implemented by the heaps themselves.
> 
> 
> New in v3:
> * Proper /dev/heap/* names on both Android and classic Linux
>   environments
> * Major rework of the helper code from Andrew
> * Dummy test device added to test importing
> * *Lots* of cleanups suggested by many (thank you for all the
>   input)!
> 
> 
> Outstanding concerns:
> * Potential need for private flags in interface for secure
>   heaps. Need to better understand secure heap usage.
> * Making sure the performance issues from potentially unnecessary
>   cache-management operations can be resolved properly for system
>   and cma heaps (outstanding issue from ION).
> 
> 
> Eventual TODOS:
> * Sanity filtering for heap names
> * Reimplement performance optimizations for system heap
> * Add stats accounting to system/cma heaps
> * Make the kselftest more useful
> * Add other heaps folks see as useful (would love to get
>   some help from actual carveout/chunk users)!
> 
> That said, the main user-interface is shaping up and I wanted
> to get some input on the device model (particularly from GreKH)
> and any other API/ABI specific input. 
> 
> thanks
> -john
> 
> Cc: Laura Abbott <labbott@redhat.com>
> Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
> Cc: Sumit Semwal <sumit.semwal@linaro.org>
> Cc: Liam Mark <lmark@codeaurora.org>
> Cc: Pratik Patel <pratikp@codeaurora.org>
> Cc: Brian Starkey <Brian.Starkey@arm.com>
> Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
> Cc: Sudipto Paul <Sudipto.Paul@arm.com>
> Cc: Andrew F. Davis <afd@ti.com>
> Cc: Xu YiPing <xuyiping@hisilicon.com>
> Cc: "Chenfeng (puck)" <puck.chen@hisilicon.com>
> Cc: butao <butao@hisilicon.com>
> Cc: "Xiaqing (A)" <saberlily.xia@hisilicon.com>
> Cc: Yudongbin <yudongbin@hisilicon.com>
> Cc: Christoph Hellwig <hch@infradead.org>
> Cc: Chenbo Feng <fengc@google.com>
> Cc: Alistair Strachan <astrachan@google.com>
> Cc: dri-devel@lists.freedesktop.org
> 
> Andrew F. Davis (2):
>   dma-buf: Add dma-buf heaps framework
>   dma-buf: Add Dummy Importer Test Device
> 
> John Stultz (4):
>   dma-buf: heaps: Add heap helpers
>   dma-buf: heaps: Add system heap to dmabuf heaps
>   dma-buf: heaps: Add CMA heap to dmabuf heapss
>   kselftests: Add dma-heap test
> 
>  MAINTAINERS                                        |  18 ++
>  drivers/dma-buf/Kconfig                            |  16 ++
>  drivers/dma-buf/Makefile                           |   3 +
>  drivers/dma-buf/dma-buf-testdev.c                  | 239 +++++++++++++++++++
>  drivers/dma-buf/dma-heap.c                         | 234 ++++++++++++++++++
>  drivers/dma-buf/heaps/Kconfig                      |  14 ++
>  drivers/dma-buf/heaps/Makefile                     |   4 +
>  drivers/dma-buf/heaps/cma_heap.c                   | 170 ++++++++++++++
>  drivers/dma-buf/heaps/heap-helpers.c               | 261 +++++++++++++++++++++
>  drivers/dma-buf/heaps/heap-helpers.h               |  55 +++++
>  drivers/dma-buf/heaps/system_heap.c                | 120 ++++++++++
>  include/linux/dma-heap.h                           |  58 +++++
>  include/uapi/linux/dma-buf-testdev.h               |  37 +++
>  include/uapi/linux/dma-heap.h                      |  52 ++++
>  tools/testing/selftests/dmabuf-heaps/Makefile      |  11 +
>  tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c | 169 +++++++++++++
>  16 files changed, 1461 insertions(+)
>  create mode 100644 drivers/dma-buf/dma-buf-testdev.c
>  create mode 100644 drivers/dma-buf/dma-heap.c
>  create mode 100644 drivers/dma-buf/heaps/Kconfig
>  create mode 100644 drivers/dma-buf/heaps/Makefile
>  create mode 100644 drivers/dma-buf/heaps/cma_heap.c
>  create mode 100644 drivers/dma-buf/heaps/heap-helpers.c
>  create mode 100644 drivers/dma-buf/heaps/heap-helpers.h
>  create mode 100644 drivers/dma-buf/heaps/system_heap.c
>  create mode 100644 include/linux/dma-heap.h
>  create mode 100644 include/uapi/linux/dma-buf-testdev.h
>  create mode 100644 include/uapi/linux/dma-heap.h
>  create mode 100644 tools/testing/selftests/dmabuf-heaps/Makefile
>  create mode 100644 tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c
> 

Re: [RFC][PATCH 0/6 v3] DMA-BUF Heaps (destaging ION)

[Andrew F. Davis]

On 3/28/19 7:15 PM, John Stultz wrote:
> Here is another RFC of the dma-buf heaps patchset Andrew and I
> have been working on which tries to destage a fair chunk of ION
> functionality.
> 
> The patchset implements per-heap devices which can be opened
> directly and then an ioctl is used to allocate a dmabuf from the
> heap.
> 
> The interface is similar, but much simpler then IONs, only
> providing an ALLOC ioctl.
> 
> Also, I've provided simple system and cma heaps. The system
> heap in particular is missing the page-pool optimizations ION
> had, but works well enough to validate the interface.
> 
> I've booted and tested these patches with AOSP on the HiKey960
> using the kernel tree here:
>   https://git.linaro.org/people/john.stultz/android-dev.git/log/?h=dev/dma-buf-heap
> 
> And the userspace changes here:
>   https://android-review.googlesource.com/c/device/linaro/hikey/+/909436
> 
> 
> Compared to ION, this patchset is missing the system-contig,
> carveout and chunk heaps, as I don't have a device that uses
> those, so I'm unable to do much useful validation there.
> Additionally we have no upstream users of chunk or carveout,
> and the system-contig has been deprecated in the common/andoid-*
> kernels, so this should be ok.
> 


I'd like to go over my use-cases for a moment to see if we can get some
agreement on what to do with the carveout/chunk heaps.

We used DRM (omapdrm) to get buffers for display, GPU, and multi-media.
Our out-of-tree CMEM driver[0] for remote processing (OpenCL/CV/VX)
buffers. And for secure heaps we use what are basically slightly
modified ION carveout heaps.

Now with the DMA-Heap framework what we can do is for sub-systems with
IOMMUs use 'system' heap (GPU). For those that need contiguous memory
(display, MM) we have 'cma' heap (and maybe 'system-contig' at some
point). For our SRAM areas used in remote processing I've posted an RFC
for a heap[1] to provide allocations from those areas.

The above leaves one last gap for us, uncached/unmapped areas from
regular memory. I propose this is where we use the 'carveout' heap.
Right now to get some contiguous/cached memory with DT you can:

reserved-memory {
	[...]
	cma_memory {
		compatible = "shared-dma-pool";
		reg = <0x79000000 0x400000>;
		reusable;
	};

	coherent_memory@78000000 {
		reg = <0x78000000 0x800000>;
		no-map;
	};
};

'cma_memory' will show up as a 'cma' heap, so all good there.

Looking at 'coherent_memory' it will not have valid backing 'struct
page' and so cannot be given cached mappings as the standard dma memory
ops would fail. This would give this area the right properties for both
users who don't want to do all the cache maintenance ops (Liam?) and for
secure heaps that have restrictions on access from Linux running CPU.

The question then is how to mark these areas for export with DMA-Heaps?
Maybe a cma_for_each_area() like function but for dma coherent areas?

Anyway for now this is not super important and I can post a patchset at
some later point for this when I get it working and tested internally.

[0]
http://software-dl.ti.com/processor-sdk-linux/esd/docs/latest/linux/Foundational_Components_CMEM.html
[1] https://patchwork.kernel.org/patch/10863957/

Thanks,
Andrew


> I've also removed the stats accounting for now, since it should
> be implemented by the heaps themselves.
> 
> 
> New in v3:
> * Proper /dev/heap/* names on both Android and classic Linux
>   environments
> * Major rework of the helper code from Andrew
> * Dummy test device added to test importing
> * *Lots* of cleanups suggested by many (thank you for all the
>   input)!
> 
> 
> Outstanding concerns:
> * Potential need for private flags in interface for secure
>   heaps. Need to better understand secure heap usage.
> * Making sure the performance issues from potentially unnecessary
>   cache-management operations can be resolved properly for system
>   and cma heaps (outstanding issue from ION).
> 
> 
> Eventual TODOS:
> * Sanity filtering for heap names
> * Reimplement performance optimizations for system heap
> * Add stats accounting to system/cma heaps
> * Make the kselftest more useful
> * Add other heaps folks see as useful (would love to get
>   some help from actual carveout/chunk users)!
> 
> That said, the main user-interface is shaping up and I wanted
> to get some input on the device model (particularly from GreKH)
> and any other API/ABI specific input. 
> 
> thanks
> -john
> 
> Cc: Laura Abbott <labbott@redhat.com>
> Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
> Cc: Sumit Semwal <sumit.semwal@linaro.org>
> Cc: Liam Mark <lmark@codeaurora.org>
> Cc: Pratik Patel <pratikp@codeaurora.org>
> Cc: Brian Starkey <Brian.Starkey@arm.com>
> Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
> Cc: Sudipto Paul <Sudipto.Paul@arm.com>
> Cc: Andrew F. Davis <afd@ti.com>
> Cc: Xu YiPing <xuyiping@hisilicon.com>
> Cc: "Chenfeng (puck)" <puck.chen@hisilicon.com>
> Cc: butao <butao@hisilicon.com>
> Cc: "Xiaqing (A)" <saberlily.xia@hisilicon.com>
> Cc: Yudongbin <yudongbin@hisilicon.com>
> Cc: Christoph Hellwig <hch@infradead.org>
> Cc: Chenbo Feng <fengc@google.com>
> Cc: Alistair Strachan <astrachan@google.com>
> Cc: dri-devel@lists.freedesktop.org
> 
> Andrew F. Davis (2):
>   dma-buf: Add dma-buf heaps framework
>   dma-buf: Add Dummy Importer Test Device
> 
> John Stultz (4):
>   dma-buf: heaps: Add heap helpers
>   dma-buf: heaps: Add system heap to dmabuf heaps
>   dma-buf: heaps: Add CMA heap to dmabuf heapss
>   kselftests: Add dma-heap test
> 
>  MAINTAINERS                                        |  18 ++
>  drivers/dma-buf/Kconfig                            |  16 ++
>  drivers/dma-buf/Makefile                           |   3 +
>  drivers/dma-buf/dma-buf-testdev.c                  | 239 +++++++++++++++++++
>  drivers/dma-buf/dma-heap.c                         | 234 ++++++++++++++++++
>  drivers/dma-buf/heaps/Kconfig                      |  14 ++
>  drivers/dma-buf/heaps/Makefile                     |   4 +
>  drivers/dma-buf/heaps/cma_heap.c                   | 170 ++++++++++++++
>  drivers/dma-buf/heaps/heap-helpers.c               | 261 +++++++++++++++++++++
>  drivers/dma-buf/heaps/heap-helpers.h               |  55 +++++
>  drivers/dma-buf/heaps/system_heap.c                | 120 ++++++++++
>  include/linux/dma-heap.h                           |  58 +++++
>  include/uapi/linux/dma-buf-testdev.h               |  37 +++
>  include/uapi/linux/dma-heap.h                      |  52 ++++
>  tools/testing/selftests/dmabuf-heaps/Makefile      |  11 +
>  tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c | 169 +++++++++++++
>  16 files changed, 1461 insertions(+)
>  create mode 100644 drivers/dma-buf/dma-buf-testdev.c
>  create mode 100644 drivers/dma-buf/dma-heap.c
>  create mode 100644 drivers/dma-buf/heaps/Kconfig
>  create mode 100644 drivers/dma-buf/heaps/Makefile
>  create mode 100644 drivers/dma-buf/heaps/cma_heap.c
>  create mode 100644 drivers/dma-buf/heaps/heap-helpers.c
>  create mode 100644 drivers/dma-buf/heaps/heap-helpers.h
>  create mode 100644 drivers/dma-buf/heaps/system_heap.c
>  create mode 100644 include/linux/dma-heap.h
>  create mode 100644 include/uapi/linux/dma-buf-testdev.h
>  create mode 100644 include/uapi/linux/dma-heap.h
>  create mode 100644 tools/testing/selftests/dmabuf-heaps/Makefile
>  create mode 100644 tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c
> 
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Re: [RFC][PATCH 2/6 v3] dma-buf: heaps: Add heap helpers

[Andrew F. Davis]

On 3/28/19 7:15 PM, John Stultz wrote:
> Add generic helper dmabuf ops for dma heaps, so we can reduce
> the amount of duplicative code for the exported dmabufs.
> 
> This code is an evolution of the Android ION implementation, so
> thanks to its original authors and maintainters:
>   Rebecca Schultz Zavin, Colin Cross, Laura Abbott, and others!
> 
> Cc: Laura Abbott <labbott@redhat.com>
> Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
> Cc: Sumit Semwal <sumit.semwal@linaro.org>
> Cc: Liam Mark <lmark@codeaurora.org>
> Cc: Pratik Patel <pratikp@codeaurora.org>
> Cc: Brian Starkey <Brian.Starkey@arm.com>
> Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
> Cc: Sudipto Paul <Sudipto.Paul@arm.com>
> Cc: Andrew F. Davis <afd@ti.com>
> Cc: Xu YiPing <xuyiping@hisilicon.com>
> Cc: "Chenfeng (puck)" <puck.chen@hisilicon.com>
> Cc: butao <butao@hisilicon.com>
> Cc: "Xiaqing (A)" <saberlily.xia@hisilicon.com>
> Cc: Yudongbin <yudongbin@hisilicon.com>
> Cc: Christoph Hellwig <hch@infradead.org>
> Cc: Chenbo Feng <fengc@google.com>
> Cc: Alistair Strachan <astrachan@google.com>
> Cc: dri-devel@lists.freedesktop.org
> Signed-off-by: John Stultz <john.stultz@linaro.org>
> ---
> v2:
> * Removed cache management performance hack that I had
>   accidentally folded in.
> * Removed stats code that was in helpers
> * Lots of checkpatch cleanups
> 
> v3:
> * Uninline INIT_HEAP_HELPER_BUFFER (suggested by Christoph)
> * Switch to WARN on buffer destroy failure (suggested by Brian)
> * buffer->kmap_cnt decrementing cleanup (suggested by Christoph)
> * Extra buffer->vaddr checking in dma_heap_dma_buf_kmap
>   (suggested by Brian)
> * Switch to_helper_buffer from macro to inline function
>   (suggested by Benjamin)
> * Rename kmap->vmap (folded in from Andrew)
> * Use vmap for vmapping - not begin_cpu_access (folded in from
>   Andrew)
> * Drop kmap for now, as its optional (folded in from Andrew)
> * Fold dma_heap_map_user into the single caller (foled in from
>   Andrew)
> * Folded in patch from Andrew to track page list per heap not
>   sglist, which simplifies the tracking logic
> ---
>  drivers/dma-buf/Makefile             |   1 +
>  drivers/dma-buf/heaps/Makefile       |   2 +
>  drivers/dma-buf/heaps/heap-helpers.c | 261 +++++++++++++++++++++++++++++++++++
>  drivers/dma-buf/heaps/heap-helpers.h |  55 ++++++++
>  include/linux/dma-heap.h             |  14 +-
>  5 files changed, 320 insertions(+), 13 deletions(-)
>  create mode 100644 drivers/dma-buf/heaps/Makefile
>  create mode 100644 drivers/dma-buf/heaps/heap-helpers.c
>  create mode 100644 drivers/dma-buf/heaps/heap-helpers.h
> 
> diff --git a/drivers/dma-buf/Makefile b/drivers/dma-buf/Makefile
> index b0332f1..09c2f2d 100644
> --- a/drivers/dma-buf/Makefile
> +++ b/drivers/dma-buf/Makefile
> @@ -1,4 +1,5 @@
>  obj-y := dma-buf.o dma-fence.o dma-fence-array.o reservation.o seqno-fence.o
> +obj-$(CONFIG_DMABUF_HEAPS)	+= heaps/
>  obj-$(CONFIG_DMABUF_HEAPS)	+= dma-heap.o
>  obj-$(CONFIG_SYNC_FILE)		+= sync_file.o
>  obj-$(CONFIG_SW_SYNC)		+= sw_sync.o sync_debug.o
> diff --git a/drivers/dma-buf/heaps/Makefile b/drivers/dma-buf/heaps/Makefile
> new file mode 100644
> index 0000000..de49898
> --- /dev/null
> +++ b/drivers/dma-buf/heaps/Makefile
> @@ -0,0 +1,2 @@
> +# SPDX-License-Identifier: GPL-2.0
> +obj-y					+= heap-helpers.o
> diff --git a/drivers/dma-buf/heaps/heap-helpers.c b/drivers/dma-buf/heaps/heap-helpers.c
> new file mode 100644
> index 0000000..00cbdbb
> --- /dev/null
> +++ b/drivers/dma-buf/heaps/heap-helpers.c
> @@ -0,0 +1,261 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include <linux/device.h>
> +#include <linux/dma-buf.h>
> +#include <linux/err.h>
> +#include <linux/idr.h>
> +#include <linux/list.h>
> +#include <linux/slab.h>
> +#include <linux/uaccess.h>
> +#include <uapi/linux/dma-heap.h>
> +
> +#include "heap-helpers.h"
> +
> +void INIT_HEAP_HELPER_BUFFER(struct heap_helper_buffer *buffer,
> +			     void (*free)(struct heap_helper_buffer *))
> +{
> +	buffer->private_flags = 0;
> +	buffer->priv_virt = NULL;
> +	mutex_init(&buffer->lock);
> +	buffer->vmap_cnt = 0;
> +	buffer->vaddr = NULL;
> +	INIT_LIST_HEAD(&buffer->attachments);
> +	buffer->free = free;
> +}
> +
> +
> +static void *dma_heap_map_kernel(struct heap_helper_buffer *buffer)
> +{
> +	void *vaddr;
> +
> +	vaddr = vmap(buffer->pages, buffer->pagecount, VM_MAP, PAGE_KERNEL);
> +	if (!vaddr)
> +		return ERR_PTR(-ENOMEM);
> +
> +	return vaddr;
> +}
> +
> +void dma_heap_buffer_destroy(struct dma_heap_buffer *heap_buffer)
> +{
> +	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
> +
> +	if (buffer->vmap_cnt > 0) {
> +		WARN("%s: buffer still mapped in the kernel\n",
> +			     __func__);
> +		vunmap(buffer->vaddr);
> +	}
> +
> +	buffer->free(buffer);
> +}
> +
> +static void *dma_heap_buffer_vmap_get(struct dma_heap_buffer *heap_buffer)
> +{
> +	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
> +	void *vaddr;
> +
> +	if (buffer->vmap_cnt) {
> +		buffer->vmap_cnt++;
> +		return buffer->vaddr;
> +	}
> +	vaddr = dma_heap_map_kernel(buffer);
> +	if (WARN_ONCE(!vaddr,
> +		      "heap->ops->map_kernel should return ERR_PTR on error"))
> +		return ERR_PTR(-EINVAL);
> +	if (IS_ERR(vaddr))
> +		return vaddr;
> +	buffer->vaddr = vaddr;
> +	buffer->vmap_cnt++;
> +	return vaddr;
> +}
> +
> +static void dma_heap_buffer_vmap_put(struct dma_heap_buffer *heap_buffer)
> +{
> +	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
> +
> +	if (!--buffer->vmap_cnt) {
> +		vunmap(buffer->vaddr);
> +		buffer->vaddr = NULL;
> +	}
> +}
> +
> +struct dma_heaps_attachment {
> +	struct device *dev;
> +	struct sg_table table;
> +	struct list_head list;
> +};
> +
> +static int dma_heap_attach(struct dma_buf *dmabuf,
> +			      struct dma_buf_attachment *attachment)
> +{
> +	struct dma_heaps_attachment *a;
> +	struct dma_heap_buffer *heap_buffer = dmabuf->priv;
> +	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
> +	int ret;
> +
> +	a = kzalloc(sizeof(*a), GFP_KERNEL);
> +	if (!a)
> +		return -ENOMEM;
> +
> +	ret = sg_alloc_table_from_pages(&a->table, buffer->pages,
> +					buffer->pagecount, 0,
> +					buffer->pagecount << PAGE_SHIFT,
> +					GFP_KERNEL);
> +	if (ret) {
> +		kfree(a);
> +		return ret;
> +	}
> +
> +	a->dev = attachment->dev;
> +	INIT_LIST_HEAD(&a->list);
> +
> +	attachment->priv = a;
> +
> +	mutex_lock(&buffer->lock);
> +	list_add(&a->list, &buffer->attachments);
> +	mutex_unlock(&buffer->lock);
> +
> +	return 0;
> +}
> +
> +static void dma_heap_detatch(struct dma_buf *dmabuf,
> +				struct dma_buf_attachment *attachment)
> +{
> +	struct dma_heaps_attachment *a = attachment->priv;
> +	struct dma_heap_buffer *heap_buffer = dmabuf->priv;
> +	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
> +
> +	mutex_lock(&buffer->lock);
> +	list_del(&a->list);
> +	mutex_unlock(&buffer->lock);
> +
> +	sg_free_table(&a->table);
> +	kfree(a);
> +}
> +
> +static struct sg_table *dma_heap_map_dma_buf(
> +					struct dma_buf_attachment *attachment,
> +					enum dma_data_direction direction)
> +{
> +	struct dma_heaps_attachment *a = attachment->priv;
> +	struct sg_table *table;
> +
> +	table = &a->table;
> +
> +	if (!dma_map_sg(attachment->dev, table->sgl, table->nents,
> +			direction))
> +		table = ERR_PTR(-ENOMEM);
> +	return table;
> +}
> +
> +static void dma_heap_unmap_dma_buf(struct dma_buf_attachment *attachment,
> +			      struct sg_table *table,
> +			      enum dma_data_direction direction)
> +{
> +	dma_unmap_sg(attachment->dev, table->sgl, table->nents, direction);
> +}
> +
> +static vm_fault_t dma_heap_vm_fault(struct vm_fault *vmf)
> +{
> +	struct vm_area_struct *vma = vmf->vma;
> +	struct heap_helper_buffer *buffer = vma->vm_private_data;
> +
> +	vmf->page = buffer->pages[vmf->pgoff];
> +	get_page(vmf->page);
> +
> +	return 0;
> +}
> +
> +static const struct vm_operations_struct dma_heap_vm_ops = {
> +	.fault = dma_heap_vm_fault,
> +};
> +
> +static int dma_heap_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
> +{
> +	struct dma_heap_buffer *heap_buffer = dmabuf->priv;
> +	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
> +
> +	if ((vma->vm_flags & (VM_SHARED | VM_MAYSHARE)) == 0)
> +		return -EINVAL;
> +
> +	vma->vm_ops = &dma_heap_vm_ops;
> +	vma->vm_private_data = buffer;
> +
> +	return 0;
> +}
> +
> +static void dma_heap_dma_buf_release(struct dma_buf *dmabuf)
> +{
> +	struct dma_heap_buffer *buffer = dmabuf->priv;
> +
> +	dma_heap_buffer_destroy(buffer);
> +}
> +
> +static int dma_heap_dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
> +					enum dma_data_direction direction)
> +{
> +	struct dma_heap_buffer *heap_buffer = dmabuf->priv;
> +	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
> +	struct dma_heaps_attachment *a;
> +	int ret = 0;
> +
> +	mutex_lock(&buffer->lock);
> +	list_for_each_entry(a, &buffer->attachments, list) {
> +		dma_sync_sg_for_cpu(a->dev, a->table.sgl, a->table.nents,
> +				    direction);
> +	}
> +	mutex_unlock(&buffer->lock);
> +
> +	return ret;
> +}
> +
> +static int dma_heap_dma_buf_end_cpu_access(struct dma_buf *dmabuf,
> +				      enum dma_data_direction direction)
> +{
> +	struct dma_heap_buffer *heap_buffer = dmabuf->priv;
> +	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
> +	struct dma_heaps_attachment *a;
> +
> +	mutex_lock(&buffer->lock);
> +	list_for_each_entry(a, &buffer->attachments, list) {
> +		dma_sync_sg_for_device(a->dev, a->table.sgl, a->table.nents,
> +				       direction);
> +	}
> +	mutex_unlock(&buffer->lock);
> +
> +	return 0;
> +}
> +
> +void *dma_heap_dma_buf_vmap(struct dma_buf *dmabuf)
> +{
> +	struct dma_heap_buffer *heap_buffer = dmabuf->priv;
> +	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
> +	void *vaddr;
> +
> +	mutex_lock(&buffer->lock);
> +	vaddr = dma_heap_buffer_vmap_get(heap_buffer);
> +	mutex_unlock(&buffer->lock);
> +
> +	return vaddr;
> +}
> +
> +void dma_heap_dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr)
> +{
> +	struct dma_heap_buffer *heap_buffer = dmabuf->priv;
> +	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
> +
> +	mutex_lock(&buffer->lock);
> +	dma_heap_buffer_vmap_put(heap_buffer);
> +	mutex_unlock(&buffer->lock);
> +}
> +
> +const struct dma_buf_ops heap_helper_ops = {
> +	.map_dma_buf = dma_heap_map_dma_buf,
> +	.unmap_dma_buf = dma_heap_unmap_dma_buf,
> +	.mmap = dma_heap_mmap,
> +	.release = dma_heap_dma_buf_release,
> +	.attach = dma_heap_attach,
> +	.detach = dma_heap_detatch,
> +	.begin_cpu_access = dma_heap_dma_buf_begin_cpu_access,
> +	.end_cpu_access = dma_heap_dma_buf_end_cpu_access,
> +	.vmap = dma_heap_dma_buf_vmap,
> +	.vunmap = dma_heap_dma_buf_vunmap,
> +};
> diff --git a/drivers/dma-buf/heaps/heap-helpers.h b/drivers/dma-buf/heaps/heap-helpers.h
> new file mode 100644
> index 0000000..a17502d
> --- /dev/null
> +++ b/drivers/dma-buf/heaps/heap-helpers.h
> @@ -0,0 +1,55 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * DMABUF Heaps helper code
> + *
> + * Copyright (C) 2011 Google, Inc.
> + * Copyright (C) 2019 Linaro Ltd.
> + */
> +
> +#ifndef _HEAP_HELPERS_H
> +#define _HEAP_HELPERS_H
> +
> +#include <linux/dma-heap.h>
> +#include <linux/list.h>
> +
> +/**
> + * struct dma_heap_buffer - metadata for a particular buffer
> + * @heap:		back pointer to the heap the buffer came from
> + * @dmabuf:		backing dma-buf for this buffer
> + * @size:		size of the buffer
> + * @flags:		buffer specific flags
> + */
> +struct dma_heap_buffer {
> +	struct dma_heap *heap;
> +	struct dma_buf *dmabuf;
> +	size_t size;
> +	unsigned long flags;
> +};
> +
> +struct heap_helper_buffer {
> +	struct dma_heap_buffer heap_buffer;
> +
> +	unsigned long private_flags;
> +	void *priv_virt;
> +	struct mutex lock;
> +	int vmap_cnt;
> +	void *vaddr;
> +	pgoff_t pagecount;
> +	struct page **pages;
> +	struct list_head attachments;
> +
> +	void (*free)(struct heap_helper_buffer *buffer);
> +
> +};
> +
> +static inline struct heap_helper_buffer *to_helper_buffer(
> +						struct dma_heap_buffer *h)
> +{
> +	return container_of(h, struct heap_helper_buffer, heap_buffer);
> +}
> +
> +void INIT_HEAP_HELPER_BUFFER(struct heap_helper_buffer *buffer,
> +				 void (*free)(struct heap_helper_buffer *));
> +extern const struct dma_buf_ops heap_helper_ops;
> +
> +#endif /* _HEAP_HELPERS_H */
> diff --git a/include/linux/dma-heap.h b/include/linux/dma-heap.h
> index d7bf624..d17b839 100644
> --- a/include/linux/dma-heap.h
> +++ b/include/linux/dma-heap.h
> @@ -12,19 +12,7 @@
>  #include <linux/cdev.h>
>  #include <linux/types.h>
>  
> -/**
> - * struct dma_heap_buffer - metadata for a particular buffer
> - * @heap:		back pointer to the heap the buffer came from
> - * @dmabuf:		backing dma-buf for this buffer
> - * @size:		size of the buffer
> - * @flags:		buffer specific flags
> - */
> -struct dma_heap_buffer {
> -	struct dma_heap *heap;
> -	struct dma_buf *dmabuf;
> -	size_t size;
> -	unsigned long flags;
> -};
> +struct dma_heap;
>  

This change can get squashed into the first patch.

Andrew

>  /**
>   * struct dma_heap_ops - ops to operate on a given heap
> 

Re: [RFC][PATCH 2/6 v3] dma-buf: heaps: Add heap helpers

[Andrew F. Davis]

On 3/28/19 7:15 PM, John Stultz wrote:
> Add generic helper dmabuf ops for dma heaps, so we can reduce
> the amount of duplicative code for the exported dmabufs.
> 
> This code is an evolution of the Android ION implementation, so
> thanks to its original authors and maintainters:
>   Rebecca Schultz Zavin, Colin Cross, Laura Abbott, and others!
> 
> Cc: Laura Abbott <labbott@redhat.com>
> Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
> Cc: Sumit Semwal <sumit.semwal@linaro.org>
> Cc: Liam Mark <lmark@codeaurora.org>
> Cc: Pratik Patel <pratikp@codeaurora.org>
> Cc: Brian Starkey <Brian.Starkey@arm.com>
> Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
> Cc: Sudipto Paul <Sudipto.Paul@arm.com>
> Cc: Andrew F. Davis <afd@ti.com>
> Cc: Xu YiPing <xuyiping@hisilicon.com>
> Cc: "Chenfeng (puck)" <puck.chen@hisilicon.com>
> Cc: butao <butao@hisilicon.com>
> Cc: "Xiaqing (A)" <saberlily.xia@hisilicon.com>
> Cc: Yudongbin <yudongbin@hisilicon.com>
> Cc: Christoph Hellwig <hch@infradead.org>
> Cc: Chenbo Feng <fengc@google.com>
> Cc: Alistair Strachan <astrachan@google.com>
> Cc: dri-devel@lists.freedesktop.org
> Signed-off-by: John Stultz <john.stultz@linaro.org>
> ---
> v2:
> * Removed cache management performance hack that I had
>   accidentally folded in.
> * Removed stats code that was in helpers
> * Lots of checkpatch cleanups
> 
> v3:
> * Uninline INIT_HEAP_HELPER_BUFFER (suggested by Christoph)
> * Switch to WARN on buffer destroy failure (suggested by Brian)
> * buffer->kmap_cnt decrementing cleanup (suggested by Christoph)
> * Extra buffer->vaddr checking in dma_heap_dma_buf_kmap
>   (suggested by Brian)
> * Switch to_helper_buffer from macro to inline function
>   (suggested by Benjamin)
> * Rename kmap->vmap (folded in from Andrew)
> * Use vmap for vmapping - not begin_cpu_access (folded in from
>   Andrew)
> * Drop kmap for now, as its optional (folded in from Andrew)
> * Fold dma_heap_map_user into the single caller (foled in from
>   Andrew)
> * Folded in patch from Andrew to track page list per heap not
>   sglist, which simplifies the tracking logic
> ---
>  drivers/dma-buf/Makefile             |   1 +
>  drivers/dma-buf/heaps/Makefile       |   2 +
>  drivers/dma-buf/heaps/heap-helpers.c | 261 +++++++++++++++++++++++++++++++++++
>  drivers/dma-buf/heaps/heap-helpers.h |  55 ++++++++
>  include/linux/dma-heap.h             |  14 +-
>  5 files changed, 320 insertions(+), 13 deletions(-)
>  create mode 100644 drivers/dma-buf/heaps/Makefile
>  create mode 100644 drivers/dma-buf/heaps/heap-helpers.c
>  create mode 100644 drivers/dma-buf/heaps/heap-helpers.h
> 
> diff --git a/drivers/dma-buf/Makefile b/drivers/dma-buf/Makefile
> index b0332f1..09c2f2d 100644
> --- a/drivers/dma-buf/Makefile
> +++ b/drivers/dma-buf/Makefile
> @@ -1,4 +1,5 @@
>  obj-y := dma-buf.o dma-fence.o dma-fence-array.o reservation.o seqno-fence.o
> +obj-$(CONFIG_DMABUF_HEAPS)	+= heaps/
>  obj-$(CONFIG_DMABUF_HEAPS)	+= dma-heap.o
>  obj-$(CONFIG_SYNC_FILE)		+= sync_file.o
>  obj-$(CONFIG_SW_SYNC)		+= sw_sync.o sync_debug.o
> diff --git a/drivers/dma-buf/heaps/Makefile b/drivers/dma-buf/heaps/Makefile
> new file mode 100644
> index 0000000..de49898
> --- /dev/null
> +++ b/drivers/dma-buf/heaps/Makefile
> @@ -0,0 +1,2 @@
> +# SPDX-License-Identifier: GPL-2.0
> +obj-y					+= heap-helpers.o
> diff --git a/drivers/dma-buf/heaps/heap-helpers.c b/drivers/dma-buf/heaps/heap-helpers.c
> new file mode 100644
> index 0000000..00cbdbb
> --- /dev/null
> +++ b/drivers/dma-buf/heaps/heap-helpers.c
> @@ -0,0 +1,261 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include <linux/device.h>
> +#include <linux/dma-buf.h>
> +#include <linux/err.h>
> +#include <linux/idr.h>
> +#include <linux/list.h>
> +#include <linux/slab.h>
> +#include <linux/uaccess.h>
> +#include <uapi/linux/dma-heap.h>
> +
> +#include "heap-helpers.h"
> +
> +void INIT_HEAP_HELPER_BUFFER(struct heap_helper_buffer *buffer,
> +			     void (*free)(struct heap_helper_buffer *))
> +{
> +	buffer->private_flags = 0;
> +	buffer->priv_virt = NULL;
> +	mutex_init(&buffer->lock);
> +	buffer->vmap_cnt = 0;
> +	buffer->vaddr = NULL;
> +	INIT_LIST_HEAD(&buffer->attachments);
> +	buffer->free = free;
> +}
> +
> +
> +static void *dma_heap_map_kernel(struct heap_helper_buffer *buffer)
> +{
> +	void *vaddr;
> +
> +	vaddr = vmap(buffer->pages, buffer->pagecount, VM_MAP, PAGE_KERNEL);
> +	if (!vaddr)
> +		return ERR_PTR(-ENOMEM);
> +
> +	return vaddr;
> +}
> +
> +void dma_heap_buffer_destroy(struct dma_heap_buffer *heap_buffer)
> +{
> +	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
> +
> +	if (buffer->vmap_cnt > 0) {
> +		WARN("%s: buffer still mapped in the kernel\n",
> +			     __func__);
> +		vunmap(buffer->vaddr);
> +	}
> +
> +	buffer->free(buffer);
> +}
> +
> +static void *dma_heap_buffer_vmap_get(struct dma_heap_buffer *heap_buffer)
> +{
> +	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
> +	void *vaddr;
> +
> +	if (buffer->vmap_cnt) {
> +		buffer->vmap_cnt++;
> +		return buffer->vaddr;
> +	}
> +	vaddr = dma_heap_map_kernel(buffer);
> +	if (WARN_ONCE(!vaddr,
> +		      "heap->ops->map_kernel should return ERR_PTR on error"))
> +		return ERR_PTR(-EINVAL);
> +	if (IS_ERR(vaddr))
> +		return vaddr;
> +	buffer->vaddr = vaddr;
> +	buffer->vmap_cnt++;
> +	return vaddr;
> +}
> +
> +static void dma_heap_buffer_vmap_put(struct dma_heap_buffer *heap_buffer)
> +{
> +	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
> +
> +	if (!--buffer->vmap_cnt) {
> +		vunmap(buffer->vaddr);
> +		buffer->vaddr = NULL;
> +	}
> +}
> +
> +struct dma_heaps_attachment {
> +	struct device *dev;
> +	struct sg_table table;
> +	struct list_head list;
> +};
> +
> +static int dma_heap_attach(struct dma_buf *dmabuf,
> +			      struct dma_buf_attachment *attachment)
> +{
> +	struct dma_heaps_attachment *a;
> +	struct dma_heap_buffer *heap_buffer = dmabuf->priv;
> +	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
> +	int ret;
> +
> +	a = kzalloc(sizeof(*a), GFP_KERNEL);
> +	if (!a)
> +		return -ENOMEM;
> +
> +	ret = sg_alloc_table_from_pages(&a->table, buffer->pages,
> +					buffer->pagecount, 0,
> +					buffer->pagecount << PAGE_SHIFT,
> +					GFP_KERNEL);
> +	if (ret) {
> +		kfree(a);
> +		return ret;
> +	}
> +
> +	a->dev = attachment->dev;
> +	INIT_LIST_HEAD(&a->list);
> +
> +	attachment->priv = a;
> +
> +	mutex_lock(&buffer->lock);
> +	list_add(&a->list, &buffer->attachments);
> +	mutex_unlock(&buffer->lock);
> +
> +	return 0;
> +}
> +
> +static void dma_heap_detatch(struct dma_buf *dmabuf,
> +				struct dma_buf_attachment *attachment)
> +{
> +	struct dma_heaps_attachment *a = attachment->priv;
> +	struct dma_heap_buffer *heap_buffer = dmabuf->priv;
> +	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
> +
> +	mutex_lock(&buffer->lock);
> +	list_del(&a->list);
> +	mutex_unlock(&buffer->lock);
> +
> +	sg_free_table(&a->table);
> +	kfree(a);
> +}
> +
> +static struct sg_table *dma_heap_map_dma_buf(
> +					struct dma_buf_attachment *attachment,
> +					enum dma_data_direction direction)
> +{
> +	struct dma_heaps_attachment *a = attachment->priv;
> +	struct sg_table *table;
> +
> +	table = &a->table;
> +
> +	if (!dma_map_sg(attachment->dev, table->sgl, table->nents,
> +			direction))
> +		table = ERR_PTR(-ENOMEM);
> +	return table;
> +}
> +
> +static void dma_heap_unmap_dma_buf(struct dma_buf_attachment *attachment,
> +			      struct sg_table *table,
> +			      enum dma_data_direction direction)
> +{
> +	dma_unmap_sg(attachment->dev, table->sgl, table->nents, direction);
> +}
> +
> +static vm_fault_t dma_heap_vm_fault(struct vm_fault *vmf)
> +{
> +	struct vm_area_struct *vma = vmf->vma;
> +	struct heap_helper_buffer *buffer = vma->vm_private_data;
> +
> +	vmf->page = buffer->pages[vmf->pgoff];
> +	get_page(vmf->page);
> +
> +	return 0;
> +}
> +
> +static const struct vm_operations_struct dma_heap_vm_ops = {
> +	.fault = dma_heap_vm_fault,
> +};
> +
> +static int dma_heap_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
> +{
> +	struct dma_heap_buffer *heap_buffer = dmabuf->priv;
> +	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
> +
> +	if ((vma->vm_flags & (VM_SHARED | VM_MAYSHARE)) == 0)
> +		return -EINVAL;
> +
> +	vma->vm_ops = &dma_heap_vm_ops;
> +	vma->vm_private_data = buffer;
> +
> +	return 0;
> +}
> +
> +static void dma_heap_dma_buf_release(struct dma_buf *dmabuf)
> +{
> +	struct dma_heap_buffer *buffer = dmabuf->priv;
> +
> +	dma_heap_buffer_destroy(buffer);
> +}
> +
> +static int dma_heap_dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
> +					enum dma_data_direction direction)
> +{
> +	struct dma_heap_buffer *heap_buffer = dmabuf->priv;
> +	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
> +	struct dma_heaps_attachment *a;
> +	int ret = 0;
> +
> +	mutex_lock(&buffer->lock);
> +	list_for_each_entry(a, &buffer->attachments, list) {
> +		dma_sync_sg_for_cpu(a->dev, a->table.sgl, a->table.nents,
> +				    direction);
> +	}
> +	mutex_unlock(&buffer->lock);
> +
> +	return ret;
> +}
> +
> +static int dma_heap_dma_buf_end_cpu_access(struct dma_buf *dmabuf,
> +				      enum dma_data_direction direction)
> +{
> +	struct dma_heap_buffer *heap_buffer = dmabuf->priv;
> +	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
> +	struct dma_heaps_attachment *a;
> +
> +	mutex_lock(&buffer->lock);
> +	list_for_each_entry(a, &buffer->attachments, list) {
> +		dma_sync_sg_for_device(a->dev, a->table.sgl, a->table.nents,
> +				       direction);
> +	}
> +	mutex_unlock(&buffer->lock);
> +
> +	return 0;
> +}
> +
> +void *dma_heap_dma_buf_vmap(struct dma_buf *dmabuf)
> +{
> +	struct dma_heap_buffer *heap_buffer = dmabuf->priv;
> +	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
> +	void *vaddr;
> +
> +	mutex_lock(&buffer->lock);
> +	vaddr = dma_heap_buffer_vmap_get(heap_buffer);
> +	mutex_unlock(&buffer->lock);
> +
> +	return vaddr;
> +}
> +
> +void dma_heap_dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr)
> +{
> +	struct dma_heap_buffer *heap_buffer = dmabuf->priv;
> +	struct heap_helper_buffer *buffer = to_helper_buffer(heap_buffer);
> +
> +	mutex_lock(&buffer->lock);
> +	dma_heap_buffer_vmap_put(heap_buffer);
> +	mutex_unlock(&buffer->lock);
> +}
> +
> +const struct dma_buf_ops heap_helper_ops = {
> +	.map_dma_buf = dma_heap_map_dma_buf,
> +	.unmap_dma_buf = dma_heap_unmap_dma_buf,
> +	.mmap = dma_heap_mmap,
> +	.release = dma_heap_dma_buf_release,
> +	.attach = dma_heap_attach,
> +	.detach = dma_heap_detatch,
> +	.begin_cpu_access = dma_heap_dma_buf_begin_cpu_access,
> +	.end_cpu_access = dma_heap_dma_buf_end_cpu_access,
> +	.vmap = dma_heap_dma_buf_vmap,
> +	.vunmap = dma_heap_dma_buf_vunmap,
> +};
> diff --git a/drivers/dma-buf/heaps/heap-helpers.h b/drivers/dma-buf/heaps/heap-helpers.h
> new file mode 100644
> index 0000000..a17502d
> --- /dev/null
> +++ b/drivers/dma-buf/heaps/heap-helpers.h
> @@ -0,0 +1,55 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * DMABUF Heaps helper code
> + *
> + * Copyright (C) 2011 Google, Inc.
> + * Copyright (C) 2019 Linaro Ltd.
> + */
> +
> +#ifndef _HEAP_HELPERS_H
> +#define _HEAP_HELPERS_H
> +
> +#include <linux/dma-heap.h>
> +#include <linux/list.h>
> +
> +/**
> + * struct dma_heap_buffer - metadata for a particular buffer
> + * @heap:		back pointer to the heap the buffer came from
> + * @dmabuf:		backing dma-buf for this buffer
> + * @size:		size of the buffer
> + * @flags:		buffer specific flags
> + */
> +struct dma_heap_buffer {
> +	struct dma_heap *heap;
> +	struct dma_buf *dmabuf;
> +	size_t size;
> +	unsigned long flags;
> +};
> +
> +struct heap_helper_buffer {
> +	struct dma_heap_buffer heap_buffer;
> +
> +	unsigned long private_flags;
> +	void *priv_virt;
> +	struct mutex lock;
> +	int vmap_cnt;
> +	void *vaddr;
> +	pgoff_t pagecount;
> +	struct page **pages;
> +	struct list_head attachments;
> +
> +	void (*free)(struct heap_helper_buffer *buffer);
> +
> +};
> +
> +static inline struct heap_helper_buffer *to_helper_buffer(
> +						struct dma_heap_buffer *h)
> +{
> +	return container_of(h, struct heap_helper_buffer, heap_buffer);
> +}
> +
> +void INIT_HEAP_HELPER_BUFFER(struct heap_helper_buffer *buffer,
> +				 void (*free)(struct heap_helper_buffer *));
> +extern const struct dma_buf_ops heap_helper_ops;
> +
> +#endif /* _HEAP_HELPERS_H */
> diff --git a/include/linux/dma-heap.h b/include/linux/dma-heap.h
> index d7bf624..d17b839 100644
> --- a/include/linux/dma-heap.h
> +++ b/include/linux/dma-heap.h
> @@ -12,19 +12,7 @@
>  #include <linux/cdev.h>
>  #include <linux/types.h>
>  
> -/**
> - * struct dma_heap_buffer - metadata for a particular buffer
> - * @heap:		back pointer to the heap the buffer came from
> - * @dmabuf:		backing dma-buf for this buffer
> - * @size:		size of the buffer
> - * @flags:		buffer specific flags
> - */
> -struct dma_heap_buffer {
> -	struct dma_heap *heap;
> -	struct dma_buf *dmabuf;
> -	size_t size;
> -	unsigned long flags;
> -};
> +struct dma_heap;
>  

This change can get squashed into the first patch.

Andrew

>  /**
>   * struct dma_heap_ops - ops to operate on a given heap
> 
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Re: [RFC][PATCH 4/6 v3] dma-buf: heaps: Add CMA heap to dmabuf heapss

[Benjamin Gaignard]

Le ven. 29 mars 2019 à 01:16, John Stultz <john.stultz@linaro.org> a écrit :
>
> This adds a CMA heap, which allows userspace to allocate
> a dma-buf of contiguous memory out of a CMA region.
>
> This code is an evolution of the Android ION implementation, so
> thanks to its original author and maintainters:
>   Benjamin Gaignard, Laura Abbott, and others!
>
> Cc: Laura Abbott <labbott@redhat.com>
> Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
> Cc: Sumit Semwal <sumit.semwal@linaro.org>
> Cc: Liam Mark <lmark@codeaurora.org>
> Cc: Pratik Patel <pratikp@codeaurora.org>
> Cc: Brian Starkey <Brian.Starkey@arm.com>
> Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
> Cc: Sudipto Paul <Sudipto.Paul@arm.com>
> Cc: Andrew F. Davis <afd@ti.com>
> Cc: Xu YiPing <xuyiping@hisilicon.com>
> Cc: "Chenfeng (puck)" <puck.chen@hisilicon.com>
> Cc: butao <butao@hisilicon.com>
> Cc: "Xiaqing (A)" <saberlily.xia@hisilicon.com>
> Cc: Yudongbin <yudongbin@hisilicon.com>
> Cc: Christoph Hellwig <hch@infradead.org>
> Cc: Chenbo Feng <fengc@google.com>
> Cc: Alistair Strachan <astrachan@google.com>
> Cc: dri-devel@lists.freedesktop.org
> Signed-off-by: John Stultz <john.stultz@linaro.org>
> ---
> v2:
> * Switch allocate to return dmabuf fd
> * Simplify init code
> * Checkpatch fixups
> v3:
> * Switch to inline function for to_cma_heap()
> * Minor cleanups suggested by Brian
> * Fold in new registration style from Andrew
> * Folded in changes from Andrew to use simplified page list
>   from the heap helpers
> ---
>  drivers/dma-buf/heaps/Kconfig    |   8 ++
>  drivers/dma-buf/heaps/Makefile   |   1 +
>  drivers/dma-buf/heaps/cma_heap.c | 170 +++++++++++++++++++++++++++++++++++++++
>  3 files changed, 179 insertions(+)
>  create mode 100644 drivers/dma-buf/heaps/cma_heap.c
>
> diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig
> index 2050527..a5eef06 100644
> --- a/drivers/dma-buf/heaps/Kconfig
> +++ b/drivers/dma-buf/heaps/Kconfig
> @@ -4,3 +4,11 @@ config DMABUF_HEAPS_SYSTEM
>         help
>           Choose this option to enable the system dmabuf heap. The system heap
>           is backed by pages from the buddy allocator. If in doubt, say Y.
> +
> +config DMABUF_HEAPS_CMA
> +       bool "DMA-BUF CMA Heap"
> +       depends on DMABUF_HEAPS && DMA_CMA
> +       help
> +         Choose this option to enable dma-buf CMA heap. This heap is backed
> +         by the Contiguous Memory Allocator (CMA). If your system has these
> +         regions, you should say Y here.
> diff --git a/drivers/dma-buf/heaps/Makefile b/drivers/dma-buf/heaps/Makefile
> index d1808ec..6e54cde 100644
> --- a/drivers/dma-buf/heaps/Makefile
> +++ b/drivers/dma-buf/heaps/Makefile
> @@ -1,3 +1,4 @@
>  # SPDX-License-Identifier: GPL-2.0
>  obj-y                                  += heap-helpers.o
>  obj-$(CONFIG_DMABUF_HEAPS_SYSTEM)      += system_heap.o
> +obj-$(CONFIG_DMABUF_HEAPS_CMA)         += cma_heap.o
> diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c
> new file mode 100644
> index 0000000..f4485c60
> --- /dev/null
> +++ b/drivers/dma-buf/heaps/cma_heap.c
> @@ -0,0 +1,170 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * DMABUF CMA heap exporter
> + *
> + * Copyright (C) 2012, 2019 Linaro Ltd.
> + * Author: <benjamin.gaignard@linaro.org> for ST-Ericsson.
> + */
> +
> +#include <linux/device.h>
> +#include <linux/dma-buf.h>
> +#include <linux/dma-heap.h>
> +#include <linux/slab.h>
> +#include <linux/errno.h>
> +#include <linux/err.h>
> +#include <linux/cma.h>
> +#include <linux/scatterlist.h>
> +#include <linux/highmem.h>
> +
> +#include "heap-helpers.h"
> +
> +struct cma_heap {
> +       struct dma_heap *heap;
> +       struct cma *cma;
> +};
> +
> +static void cma_heap_free(struct heap_helper_buffer *buffer)
> +{
> +       struct cma_heap *cma_heap = dma_heap_get_data(buffer->heap_buffer.heap);
> +       struct page *pages = buffer->priv_virt;
> +       unsigned long nr_pages;
> +
> +       nr_pages = buffer->heap_buffer.size >> PAGE_SHIFT;
> +
> +       /* free page list */
> +       kfree(buffer->pages);
> +       /* release memory */
> +       cma_release(cma_heap->cma, pages, nr_pages);
> +       kfree(buffer);
> +}
> +
> +/* dmabuf heap CMA operations functions */
> +static int cma_heap_allocate(struct dma_heap *heap,
> +                               unsigned long len,
> +                               unsigned long flags)
> +{
> +       struct cma_heap *cma_heap = dma_heap_get_data(heap);
> +       struct heap_helper_buffer *helper_buffer;
> +       struct page *pages;
> +       size_t size = PAGE_ALIGN(len);
> +       unsigned long nr_pages = size >> PAGE_SHIFT;
> +       unsigned long align = get_order(size);
> +       DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
> +       struct dma_buf *dmabuf;
> +       int ret = -ENOMEM;
> +       pgoff_t pg;
> +
> +       if (align > CONFIG_CMA_ALIGNMENT)
> +               align = CONFIG_CMA_ALIGNMENT;
> +
> +       helper_buffer = kzalloc(sizeof(*helper_buffer), GFP_KERNEL);
> +       if (!helper_buffer)
> +               return -ENOMEM;
> +
> +       INIT_HEAP_HELPER_BUFFER(helper_buffer, cma_heap_free);
> +       helper_buffer->heap_buffer.flags = flags;
> +       helper_buffer->heap_buffer.heap = heap;
> +       helper_buffer->heap_buffer.size = len;
> +
> +       pages = cma_alloc(cma_heap->cma, nr_pages, align, false);
> +       if (!pages)
> +               goto free_buf;
> +
> +       if (PageHighMem(pages)) {
> +               unsigned long nr_clear_pages = nr_pages;
> +               struct page *page = pages;
> +
> +               while (nr_clear_pages > 0) {
> +                       void *vaddr = kmap_atomic(page);
> +
> +                       memset(vaddr, 0, PAGE_SIZE);
> +                       kunmap_atomic(vaddr);
> +                       page++;
> +                       nr_clear_pages--;
> +               }
> +       } else {
> +               memset(page_address(pages), 0, size);
> +       }
> +
> +       helper_buffer->pagecount = nr_pages;
> +       helper_buffer->pages = kmalloc_array(helper_buffer->pagecount,
> +                                            sizeof(*helper_buffer->pages),
> +                                            GFP_KERNEL);
> +       if (!helper_buffer->pages) {
> +               ret = -ENOMEM;
> +               goto free_cma;
> +       }
> +
> +       for (pg = 0; pg < helper_buffer->pagecount; pg++) {
> +               helper_buffer->pages[pg] = &pages[pg];
> +               if (!helper_buffer->pages[pg])
> +                       goto free_pages;
> +       }
> +
> +       /* create the dmabuf */
> +       exp_info.ops = &heap_helper_ops;
> +       exp_info.size = len;
> +       exp_info.flags = O_RDWR;

I think that the flags should be provided when requesting the allocation
like it is done in DRM or V4L2.
For me DMA_HEAP_VALID_FLAGS = (O_CLOEXEC | O_ACCMODE).

Benjamin

Benjamin

> +       exp_info.priv = &helper_buffer->heap_buffer;
> +       dmabuf = dma_buf_export(&exp_info);
> +       if (IS_ERR(dmabuf)) {
> +               ret = PTR_ERR(dmabuf);
> +               goto free_pages;
> +       }
> +
> +       helper_buffer->heap_buffer.dmabuf = dmabuf;
> +       helper_buffer->priv_virt = pages;
> +
> +       ret = dma_buf_fd(dmabuf, O_CLOEXEC);
> +       if (ret < 0) {
> +               dma_buf_put(dmabuf);
> +               /* just return, as put will call release and that will free */
> +               return ret;
> +       }
> +
> +       return ret;
> +
> +free_pages:
> +       kfree(helper_buffer->pages);
> +free_cma:
> +       cma_release(cma_heap->cma, pages, nr_pages);
> +free_buf:
> +       kfree(helper_buffer);
> +       return ret;
> +}
> +
> +static struct dma_heap_ops cma_heap_ops = {
> +       .allocate = cma_heap_allocate,
> +};
> +
> +static int __add_cma_heap(struct cma *cma, void *data)
> +{
> +       struct cma_heap *cma_heap;
> +       struct dma_heap_export_info exp_info;
> +
> +       cma_heap = kzalloc(sizeof(*cma_heap), GFP_KERNEL);
> +       if (!cma_heap)
> +               return -ENOMEM;
> +       cma_heap->cma = cma;
> +
> +       exp_info.name = cma_get_name(cma);
> +       exp_info.ops = &cma_heap_ops;
> +       exp_info.priv = cma_heap;
> +
> +       cma_heap->heap = dma_heap_add(&exp_info);
> +       if (IS_ERR(cma_heap->heap)) {
> +               int ret = PTR_ERR(cma_heap->heap);
> +
> +               kfree(cma_heap);
> +               return ret;
> +       }
> +
> +       return 0;
> +}
> +
> +static int add_cma_heaps(void)
> +{
> +       cma_for_each_area(__add_cma_heap, NULL);
> +       return 0;
> +}
> +device_initcall(add_cma_heaps);
> --
> 2.7.4
>

Re: [RFC][PATCH 4/6 v3] dma-buf: heaps: Add CMA heap to dmabuf heapss

[Andrew F. Davis]

On 3/29/19 9:44 AM, Benjamin Gaignard wrote:
> Le ven. 29 mars 2019 à 01:16, John Stultz <john.stultz@linaro.org> a écrit :
>>
>> This adds a CMA heap, which allows userspace to allocate
>> a dma-buf of contiguous memory out of a CMA region.
>>
>> This code is an evolution of the Android ION implementation, so
>> thanks to its original author and maintainters:
>>   Benjamin Gaignard, Laura Abbott, and others!
>>
>> Cc: Laura Abbott <labbott@redhat.com>
>> Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
>> Cc: Sumit Semwal <sumit.semwal@linaro.org>
>> Cc: Liam Mark <lmark@codeaurora.org>
>> Cc: Pratik Patel <pratikp@codeaurora.org>
>> Cc: Brian Starkey <Brian.Starkey@arm.com>
>> Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
>> Cc: Sudipto Paul <Sudipto.Paul@arm.com>
>> Cc: Andrew F. Davis <afd@ti.com>
>> Cc: Xu YiPing <xuyiping@hisilicon.com>
>> Cc: "Chenfeng (puck)" <puck.chen@hisilicon.com>
>> Cc: butao <butao@hisilicon.com>
>> Cc: "Xiaqing (A)" <saberlily.xia@hisilicon.com>
>> Cc: Yudongbin <yudongbin@hisilicon.com>
>> Cc: Christoph Hellwig <hch@infradead.org>
>> Cc: Chenbo Feng <fengc@google.com>
>> Cc: Alistair Strachan <astrachan@google.com>
>> Cc: dri-devel@lists.freedesktop.org
>> Signed-off-by: John Stultz <john.stultz@linaro.org>
>> ---
>> v2:
>> * Switch allocate to return dmabuf fd
>> * Simplify init code
>> * Checkpatch fixups
>> v3:
>> * Switch to inline function for to_cma_heap()
>> * Minor cleanups suggested by Brian
>> * Fold in new registration style from Andrew
>> * Folded in changes from Andrew to use simplified page list
>>   from the heap helpers
>> ---
>>  drivers/dma-buf/heaps/Kconfig    |   8 ++
>>  drivers/dma-buf/heaps/Makefile   |   1 +
>>  drivers/dma-buf/heaps/cma_heap.c | 170 +++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 179 insertions(+)
>>  create mode 100644 drivers/dma-buf/heaps/cma_heap.c
>>
>> diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig
>> index 2050527..a5eef06 100644
>> --- a/drivers/dma-buf/heaps/Kconfig
>> +++ b/drivers/dma-buf/heaps/Kconfig
>> @@ -4,3 +4,11 @@ config DMABUF_HEAPS_SYSTEM
>>         help
>>           Choose this option to enable the system dmabuf heap. The system heap
>>           is backed by pages from the buddy allocator. If in doubt, say Y.
>> +
>> +config DMABUF_HEAPS_CMA
>> +       bool "DMA-BUF CMA Heap"
>> +       depends on DMABUF_HEAPS && DMA_CMA
>> +       help
>> +         Choose this option to enable dma-buf CMA heap. This heap is backed
>> +         by the Contiguous Memory Allocator (CMA). If your system has these
>> +         regions, you should say Y here.
>> diff --git a/drivers/dma-buf/heaps/Makefile b/drivers/dma-buf/heaps/Makefile
>> index d1808ec..6e54cde 100644
>> --- a/drivers/dma-buf/heaps/Makefile
>> +++ b/drivers/dma-buf/heaps/Makefile
>> @@ -1,3 +1,4 @@
>>  # SPDX-License-Identifier: GPL-2.0
>>  obj-y                                  += heap-helpers.o
>>  obj-$(CONFIG_DMABUF_HEAPS_SYSTEM)      += system_heap.o
>> +obj-$(CONFIG_DMABUF_HEAPS_CMA)         += cma_heap.o
>> diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c
>> new file mode 100644
>> index 0000000..f4485c60
>> --- /dev/null
>> +++ b/drivers/dma-buf/heaps/cma_heap.c
>> @@ -0,0 +1,170 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * DMABUF CMA heap exporter
>> + *
>> + * Copyright (C) 2012, 2019 Linaro Ltd.
>> + * Author: <benjamin.gaignard@linaro.org> for ST-Ericsson.
>> + */
>> +
>> +#include <linux/device.h>
>> +#include <linux/dma-buf.h>
>> +#include <linux/dma-heap.h>
>> +#include <linux/slab.h>
>> +#include <linux/errno.h>
>> +#include <linux/err.h>
>> +#include <linux/cma.h>
>> +#include <linux/scatterlist.h>
>> +#include <linux/highmem.h>
>> +
>> +#include "heap-helpers.h"
>> +
>> +struct cma_heap {
>> +       struct dma_heap *heap;
>> +       struct cma *cma;
>> +};
>> +
>> +static void cma_heap_free(struct heap_helper_buffer *buffer)
>> +{
>> +       struct cma_heap *cma_heap = dma_heap_get_data(buffer->heap_buffer.heap);
>> +       struct page *pages = buffer->priv_virt;
>> +       unsigned long nr_pages;
>> +
>> +       nr_pages = buffer->heap_buffer.size >> PAGE_SHIFT;
>> +
>> +       /* free page list */
>> +       kfree(buffer->pages);
>> +       /* release memory */
>> +       cma_release(cma_heap->cma, pages, nr_pages);
>> +       kfree(buffer);
>> +}
>> +
>> +/* dmabuf heap CMA operations functions */
>> +static int cma_heap_allocate(struct dma_heap *heap,
>> +                               unsigned long len,
>> +                               unsigned long flags)
>> +{
>> +       struct cma_heap *cma_heap = dma_heap_get_data(heap);
>> +       struct heap_helper_buffer *helper_buffer;
>> +       struct page *pages;
>> +       size_t size = PAGE_ALIGN(len);
>> +       unsigned long nr_pages = size >> PAGE_SHIFT;
>> +       unsigned long align = get_order(size);
>> +       DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
>> +       struct dma_buf *dmabuf;
>> +       int ret = -ENOMEM;
>> +       pgoff_t pg;
>> +
>> +       if (align > CONFIG_CMA_ALIGNMENT)
>> +               align = CONFIG_CMA_ALIGNMENT;
>> +
>> +       helper_buffer = kzalloc(sizeof(*helper_buffer), GFP_KERNEL);
>> +       if (!helper_buffer)
>> +               return -ENOMEM;
>> +
>> +       INIT_HEAP_HELPER_BUFFER(helper_buffer, cma_heap_free);
>> +       helper_buffer->heap_buffer.flags = flags;
>> +       helper_buffer->heap_buffer.heap = heap;
>> +       helper_buffer->heap_buffer.size = len;
>> +
>> +       pages = cma_alloc(cma_heap->cma, nr_pages, align, false);
>> +       if (!pages)
>> +               goto free_buf;
>> +
>> +       if (PageHighMem(pages)) {
>> +               unsigned long nr_clear_pages = nr_pages;
>> +               struct page *page = pages;
>> +
>> +               while (nr_clear_pages > 0) {
>> +                       void *vaddr = kmap_atomic(page);
>> +
>> +                       memset(vaddr, 0, PAGE_SIZE);
>> +                       kunmap_atomic(vaddr);
>> +                       page++;
>> +                       nr_clear_pages--;
>> +               }
>> +       } else {
>> +               memset(page_address(pages), 0, size);
>> +       }
>> +
>> +       helper_buffer->pagecount = nr_pages;
>> +       helper_buffer->pages = kmalloc_array(helper_buffer->pagecount,
>> +                                            sizeof(*helper_buffer->pages),
>> +                                            GFP_KERNEL);
>> +       if (!helper_buffer->pages) {
>> +               ret = -ENOMEM;
>> +               goto free_cma;
>> +       }
>> +
>> +       for (pg = 0; pg < helper_buffer->pagecount; pg++) {
>> +               helper_buffer->pages[pg] = &pages[pg];
>> +               if (!helper_buffer->pages[pg])
>> +                       goto free_pages;
>> +       }
>> +
>> +       /* create the dmabuf */
>> +       exp_info.ops = &heap_helper_ops;
>> +       exp_info.size = len;
>> +       exp_info.flags = O_RDWR;
> 
> I think that the flags should be provided when requesting the allocation
> like it is done in DRM or V4L2.
> For me DMA_HEAP_VALID_FLAGS = (O_CLOEXEC | O_ACCMODE).
> 


So something like done in udmabuf?

https://elixir.bootlin.com/linux/v5.1-rc1/source/include/uapi/linux/udmabuf.h#L8

I think that can be arranged.

John,

This might be a good reason to move the dma_buf_fd() call below out of
the heap and back into the core. That way the file exporting flags can
be common and core handled. I don't think it would complicate the error
handling any as we only need to dma_buf_put(dmabuf) in the core on
failure and the heap specific cleanup will happen for us.

Andrew


> Benjamin
> 
> Benjamin
> 
>> +       exp_info.priv = &helper_buffer->heap_buffer;
>> +       dmabuf = dma_buf_export(&exp_info);
>> +       if (IS_ERR(dmabuf)) {
>> +               ret = PTR_ERR(dmabuf);
>> +               goto free_pages;
>> +       }
>> +
>> +       helper_buffer->heap_buffer.dmabuf = dmabuf;
>> +       helper_buffer->priv_virt = pages;
>> +
>> +       ret = dma_buf_fd(dmabuf, O_CLOEXEC);
>> +       if (ret < 0) {
>> +               dma_buf_put(dmabuf);
>> +               /* just return, as put will call release and that will free */
>> +               return ret;
>> +       }
>> +
>> +       return ret;
>> +
>> +free_pages:
>> +       kfree(helper_buffer->pages);
>> +free_cma:
>> +       cma_release(cma_heap->cma, pages, nr_pages);
>> +free_buf:
>> +       kfree(helper_buffer);
>> +       return ret;
>> +}
>> +
>> +static struct dma_heap_ops cma_heap_ops = {
>> +       .allocate = cma_heap_allocate,
>> +};
>> +
>> +static int __add_cma_heap(struct cma *cma, void *data)
>> +{
>> +       struct cma_heap *cma_heap;
>> +       struct dma_heap_export_info exp_info;
>> +
>> +       cma_heap = kzalloc(sizeof(*cma_heap), GFP_KERNEL);
>> +       if (!cma_heap)
>> +               return -ENOMEM;
>> +       cma_heap->cma = cma;
>> +
>> +       exp_info.name = cma_get_name(cma);
>> +       exp_info.ops = &cma_heap_ops;
>> +       exp_info.priv = cma_heap;
>> +
>> +       cma_heap->heap = dma_heap_add(&exp_info);
>> +       if (IS_ERR(cma_heap->heap)) {
>> +               int ret = PTR_ERR(cma_heap->heap);
>> +
>> +               kfree(cma_heap);
>> +               return ret;
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>> +static int add_cma_heaps(void)
>> +{
>> +       cma_for_each_area(__add_cma_heap, NULL);
>> +       return 0;
>> +}
>> +device_initcall(add_cma_heaps);
>> --
>> 2.7.4
>>

Re: [RFC][PATCH 4/6 v3] dma-buf: heaps: Add CMA heap to dmabuf heapss

[Andrew F. Davis]

On 3/29/19 9:44 AM, Benjamin Gaignard wrote:
> Le ven. 29 mars 2019 à 01:16, John Stultz <john.stultz@linaro.org> a écrit :
>>
>> This adds a CMA heap, which allows userspace to allocate
>> a dma-buf of contiguous memory out of a CMA region.
>>
>> This code is an evolution of the Android ION implementation, so
>> thanks to its original author and maintainters:
>>   Benjamin Gaignard, Laura Abbott, and others!
>>
>> Cc: Laura Abbott <labbott@redhat.com>
>> Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
>> Cc: Sumit Semwal <sumit.semwal@linaro.org>
>> Cc: Liam Mark <lmark@codeaurora.org>
>> Cc: Pratik Patel <pratikp@codeaurora.org>
>> Cc: Brian Starkey <Brian.Starkey@arm.com>
>> Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
>> Cc: Sudipto Paul <Sudipto.Paul@arm.com>
>> Cc: Andrew F. Davis <afd@ti.com>
>> Cc: Xu YiPing <xuyiping@hisilicon.com>
>> Cc: "Chenfeng (puck)" <puck.chen@hisilicon.com>
>> Cc: butao <butao@hisilicon.com>
>> Cc: "Xiaqing (A)" <saberlily.xia@hisilicon.com>
>> Cc: Yudongbin <yudongbin@hisilicon.com>
>> Cc: Christoph Hellwig <hch@infradead.org>
>> Cc: Chenbo Feng <fengc@google.com>
>> Cc: Alistair Strachan <astrachan@google.com>
>> Cc: dri-devel@lists.freedesktop.org
>> Signed-off-by: John Stultz <john.stultz@linaro.org>
>> ---
>> v2:
>> * Switch allocate to return dmabuf fd
>> * Simplify init code
>> * Checkpatch fixups
>> v3:
>> * Switch to inline function for to_cma_heap()
>> * Minor cleanups suggested by Brian
>> * Fold in new registration style from Andrew
>> * Folded in changes from Andrew to use simplified page list
>>   from the heap helpers
>> ---
>>  drivers/dma-buf/heaps/Kconfig    |   8 ++
>>  drivers/dma-buf/heaps/Makefile   |   1 +
>>  drivers/dma-buf/heaps/cma_heap.c | 170 +++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 179 insertions(+)
>>  create mode 100644 drivers/dma-buf/heaps/cma_heap.c
>>
>> diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig
>> index 2050527..a5eef06 100644
>> --- a/drivers/dma-buf/heaps/Kconfig
>> +++ b/drivers/dma-buf/heaps/Kconfig
>> @@ -4,3 +4,11 @@ config DMABUF_HEAPS_SYSTEM
>>         help
>>           Choose this option to enable the system dmabuf heap. The system heap
>>           is backed by pages from the buddy allocator. If in doubt, say Y.
>> +
>> +config DMABUF_HEAPS_CMA
>> +       bool "DMA-BUF CMA Heap"
>> +       depends on DMABUF_HEAPS && DMA_CMA
>> +       help
>> +         Choose this option to enable dma-buf CMA heap. This heap is backed
>> +         by the Contiguous Memory Allocator (CMA). If your system has these
>> +         regions, you should say Y here.
>> diff --git a/drivers/dma-buf/heaps/Makefile b/drivers/dma-buf/heaps/Makefile
>> index d1808ec..6e54cde 100644
>> --- a/drivers/dma-buf/heaps/Makefile
>> +++ b/drivers/dma-buf/heaps/Makefile
>> @@ -1,3 +1,4 @@
>>  # SPDX-License-Identifier: GPL-2.0
>>  obj-y                                  += heap-helpers.o
>>  obj-$(CONFIG_DMABUF_HEAPS_SYSTEM)      += system_heap.o
>> +obj-$(CONFIG_DMABUF_HEAPS_CMA)         += cma_heap.o
>> diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c
>> new file mode 100644
>> index 0000000..f4485c60
>> --- /dev/null
>> +++ b/drivers/dma-buf/heaps/cma_heap.c
>> @@ -0,0 +1,170 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * DMABUF CMA heap exporter
>> + *
>> + * Copyright (C) 2012, 2019 Linaro Ltd.
>> + * Author: <benjamin.gaignard@linaro.org> for ST-Ericsson.
>> + */
>> +
>> +#include <linux/device.h>
>> +#include <linux/dma-buf.h>
>> +#include <linux/dma-heap.h>
>> +#include <linux/slab.h>
>> +#include <linux/errno.h>
>> +#include <linux/err.h>
>> +#include <linux/cma.h>
>> +#include <linux/scatterlist.h>
>> +#include <linux/highmem.h>
>> +
>> +#include "heap-helpers.h"
>> +
>> +struct cma_heap {
>> +       struct dma_heap *heap;
>> +       struct cma *cma;
>> +};
>> +
>> +static void cma_heap_free(struct heap_helper_buffer *buffer)
>> +{
>> +       struct cma_heap *cma_heap = dma_heap_get_data(buffer->heap_buffer.heap);
>> +       struct page *pages = buffer->priv_virt;
>> +       unsigned long nr_pages;
>> +
>> +       nr_pages = buffer->heap_buffer.size >> PAGE_SHIFT;
>> +
>> +       /* free page list */
>> +       kfree(buffer->pages);
>> +       /* release memory */
>> +       cma_release(cma_heap->cma, pages, nr_pages);
>> +       kfree(buffer);
>> +}
>> +
>> +/* dmabuf heap CMA operations functions */
>> +static int cma_heap_allocate(struct dma_heap *heap,
>> +                               unsigned long len,
>> +                               unsigned long flags)
>> +{
>> +       struct cma_heap *cma_heap = dma_heap_get_data(heap);
>> +       struct heap_helper_buffer *helper_buffer;
>> +       struct page *pages;
>> +       size_t size = PAGE_ALIGN(len);
>> +       unsigned long nr_pages = size >> PAGE_SHIFT;
>> +       unsigned long align = get_order(size);
>> +       DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
>> +       struct dma_buf *dmabuf;
>> +       int ret = -ENOMEM;
>> +       pgoff_t pg;
>> +
>> +       if (align > CONFIG_CMA_ALIGNMENT)
>> +               align = CONFIG_CMA_ALIGNMENT;
>> +
>> +       helper_buffer = kzalloc(sizeof(*helper_buffer), GFP_KERNEL);
>> +       if (!helper_buffer)
>> +               return -ENOMEM;
>> +
>> +       INIT_HEAP_HELPER_BUFFER(helper_buffer, cma_heap_free);
>> +       helper_buffer->heap_buffer.flags = flags;
>> +       helper_buffer->heap_buffer.heap = heap;
>> +       helper_buffer->heap_buffer.size = len;
>> +
>> +       pages = cma_alloc(cma_heap->cma, nr_pages, align, false);
>> +       if (!pages)
>> +               goto free_buf;
>> +
>> +       if (PageHighMem(pages)) {
>> +               unsigned long nr_clear_pages = nr_pages;
>> +               struct page *page = pages;
>> +
>> +               while (nr_clear_pages > 0) {
>> +                       void *vaddr = kmap_atomic(page);
>> +
>> +                       memset(vaddr, 0, PAGE_SIZE);
>> +                       kunmap_atomic(vaddr);
>> +                       page++;
>> +                       nr_clear_pages--;
>> +               }
>> +       } else {
>> +               memset(page_address(pages), 0, size);
>> +       }
>> +
>> +       helper_buffer->pagecount = nr_pages;
>> +       helper_buffer->pages = kmalloc_array(helper_buffer->pagecount,
>> +                                            sizeof(*helper_buffer->pages),
>> +                                            GFP_KERNEL);
>> +       if (!helper_buffer->pages) {
>> +               ret = -ENOMEM;
>> +               goto free_cma;
>> +       }
>> +
>> +       for (pg = 0; pg < helper_buffer->pagecount; pg++) {
>> +               helper_buffer->pages[pg] = &pages[pg];
>> +               if (!helper_buffer->pages[pg])
>> +                       goto free_pages;
>> +       }
>> +
>> +       /* create the dmabuf */
>> +       exp_info.ops = &heap_helper_ops;
>> +       exp_info.size = len;
>> +       exp_info.flags = O_RDWR;
> 
> I think that the flags should be provided when requesting the allocation
> like it is done in DRM or V4L2.
> For me DMA_HEAP_VALID_FLAGS = (O_CLOEXEC | O_ACCMODE).
> 


So something like done in udmabuf?

https://elixir.bootlin.com/linux/v5.1-rc1/source/include/uapi/linux/udmabuf.h#L8

I think that can be arranged.

John,

This might be a good reason to move the dma_buf_fd() call below out of
the heap and back into the core. That way the file exporting flags can
be common and core handled. I don't think it would complicate the error
handling any as we only need to dma_buf_put(dmabuf) in the core on
failure and the heap specific cleanup will happen for us.

Andrew


> Benjamin
> 
> Benjamin
> 
>> +       exp_info.priv = &helper_buffer->heap_buffer;
>> +       dmabuf = dma_buf_export(&exp_info);
>> +       if (IS_ERR(dmabuf)) {
>> +               ret = PTR_ERR(dmabuf);
>> +               goto free_pages;
>> +       }
>> +
>> +       helper_buffer->heap_buffer.dmabuf = dmabuf;
>> +       helper_buffer->priv_virt = pages;
>> +
>> +       ret = dma_buf_fd(dmabuf, O_CLOEXEC);
>> +       if (ret < 0) {
>> +               dma_buf_put(dmabuf);
>> +               /* just return, as put will call release and that will free */
>> +               return ret;
>> +       }
>> +
>> +       return ret;
>> +
>> +free_pages:
>> +       kfree(helper_buffer->pages);
>> +free_cma:
>> +       cma_release(cma_heap->cma, pages, nr_pages);
>> +free_buf:
>> +       kfree(helper_buffer);
>> +       return ret;
>> +}
>> +
>> +static struct dma_heap_ops cma_heap_ops = {
>> +       .allocate = cma_heap_allocate,
>> +};
>> +
>> +static int __add_cma_heap(struct cma *cma, void *data)
>> +{
>> +       struct cma_heap *cma_heap;
>> +       struct dma_heap_export_info exp_info;
>> +
>> +       cma_heap = kzalloc(sizeof(*cma_heap), GFP_KERNEL);
>> +       if (!cma_heap)
>> +               return -ENOMEM;
>> +       cma_heap->cma = cma;
>> +
>> +       exp_info.name = cma_get_name(cma);
>> +       exp_info.ops = &cma_heap_ops;
>> +       exp_info.priv = cma_heap;
>> +
>> +       cma_heap->heap = dma_heap_add(&exp_info);
>> +       if (IS_ERR(cma_heap->heap)) {
>> +               int ret = PTR_ERR(cma_heap->heap);
>> +
>> +               kfree(cma_heap);
>> +               return ret;
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>> +static int add_cma_heaps(void)
>> +{
>> +       cma_for_each_area(__add_cma_heap, NULL);
>> +       return 0;
>> +}
>> +device_initcall(add_cma_heaps);
>> --
>> 2.7.4
>>
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Re: [RFC][PATCH 4/6 v3] dma-buf: heaps: Add CMA heap to dmabuf heapss

[Benjamin Gaignard]

Le ven. 29 mars 2019 à 16:19, Andrew F. Davis <afd@ti.com> a écrit :
>
> On 3/29/19 9:44 AM, Benjamin Gaignard wrote:
> > Le ven. 29 mars 2019 à 01:16, John Stultz <john.stultz@linaro.org> a écrit :
> >>
> >> This adds a CMA heap, which allows userspace to allocate
> >> a dma-buf of contiguous memory out of a CMA region.
> >>
> >> This code is an evolution of the Android ION implementation, so
> >> thanks to its original author and maintainters:
> >>   Benjamin Gaignard, Laura Abbott, and others!
> >>
> >> Cc: Laura Abbott <labbott@redhat.com>
> >> Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
> >> Cc: Sumit Semwal <sumit.semwal@linaro.org>
> >> Cc: Liam Mark <lmark@codeaurora.org>
> >> Cc: Pratik Patel <pratikp@codeaurora.org>
> >> Cc: Brian Starkey <Brian.Starkey@arm.com>
> >> Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
> >> Cc: Sudipto Paul <Sudipto.Paul@arm.com>
> >> Cc: Andrew F. Davis <afd@ti.com>
> >> Cc: Xu YiPing <xuyiping@hisilicon.com>
> >> Cc: "Chenfeng (puck)" <puck.chen@hisilicon.com>
> >> Cc: butao <butao@hisilicon.com>
> >> Cc: "Xiaqing (A)" <saberlily.xia@hisilicon.com>
> >> Cc: Yudongbin <yudongbin@hisilicon.com>
> >> Cc: Christoph Hellwig <hch@infradead.org>
> >> Cc: Chenbo Feng <fengc@google.com>
> >> Cc: Alistair Strachan <astrachan@google.com>
> >> Cc: dri-devel@lists.freedesktop.org
> >> Signed-off-by: John Stultz <john.stultz@linaro.org>
> >> ---
> >> v2:
> >> * Switch allocate to return dmabuf fd
> >> * Simplify init code
> >> * Checkpatch fixups
> >> v3:
> >> * Switch to inline function for to_cma_heap()
> >> * Minor cleanups suggested by Brian
> >> * Fold in new registration style from Andrew
> >> * Folded in changes from Andrew to use simplified page list
> >>   from the heap helpers
> >> ---
> >>  drivers/dma-buf/heaps/Kconfig    |   8 ++
> >>  drivers/dma-buf/heaps/Makefile   |   1 +
> >>  drivers/dma-buf/heaps/cma_heap.c | 170 +++++++++++++++++++++++++++++++++++++++
> >>  3 files changed, 179 insertions(+)
> >>  create mode 100644 drivers/dma-buf/heaps/cma_heap.c
> >>
> >> diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig
> >> index 2050527..a5eef06 100644
> >> --- a/drivers/dma-buf/heaps/Kconfig
> >> +++ b/drivers/dma-buf/heaps/Kconfig
> >> @@ -4,3 +4,11 @@ config DMABUF_HEAPS_SYSTEM
> >>         help
> >>           Choose this option to enable the system dmabuf heap. The system heap
> >>           is backed by pages from the buddy allocator. If in doubt, say Y.
> >> +
> >> +config DMABUF_HEAPS_CMA
> >> +       bool "DMA-BUF CMA Heap"
> >> +       depends on DMABUF_HEAPS && DMA_CMA
> >> +       help
> >> +         Choose this option to enable dma-buf CMA heap. This heap is backed
> >> +         by the Contiguous Memory Allocator (CMA). If your system has these
> >> +         regions, you should say Y here.
> >> diff --git a/drivers/dma-buf/heaps/Makefile b/drivers/dma-buf/heaps/Makefile
> >> index d1808ec..6e54cde 100644
> >> --- a/drivers/dma-buf/heaps/Makefile
> >> +++ b/drivers/dma-buf/heaps/Makefile
> >> @@ -1,3 +1,4 @@
> >>  # SPDX-License-Identifier: GPL-2.0
> >>  obj-y                                  += heap-helpers.o
> >>  obj-$(CONFIG_DMABUF_HEAPS_SYSTEM)      += system_heap.o
> >> +obj-$(CONFIG_DMABUF_HEAPS_CMA)         += cma_heap.o
> >> diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c
> >> new file mode 100644
> >> index 0000000..f4485c60
> >> --- /dev/null
> >> +++ b/drivers/dma-buf/heaps/cma_heap.c
> >> @@ -0,0 +1,170 @@
> >> +// SPDX-License-Identifier: GPL-2.0
> >> +/*
> >> + * DMABUF CMA heap exporter
> >> + *
> >> + * Copyright (C) 2012, 2019 Linaro Ltd.
> >> + * Author: <benjamin.gaignard@linaro.org> for ST-Ericsson.
> >> + */
> >> +
> >> +#include <linux/device.h>
> >> +#include <linux/dma-buf.h>
> >> +#include <linux/dma-heap.h>
> >> +#include <linux/slab.h>
> >> +#include <linux/errno.h>
> >> +#include <linux/err.h>
> >> +#include <linux/cma.h>
> >> +#include <linux/scatterlist.h>
> >> +#include <linux/highmem.h>
> >> +
> >> +#include "heap-helpers.h"
> >> +
> >> +struct cma_heap {
> >> +       struct dma_heap *heap;
> >> +       struct cma *cma;
> >> +};
> >> +
> >> +static void cma_heap_free(struct heap_helper_buffer *buffer)
> >> +{
> >> +       struct cma_heap *cma_heap = dma_heap_get_data(buffer->heap_buffer.heap);
> >> +       struct page *pages = buffer->priv_virt;
> >> +       unsigned long nr_pages;
> >> +
> >> +       nr_pages = buffer->heap_buffer.size >> PAGE_SHIFT;
> >> +
> >> +       /* free page list */
> >> +       kfree(buffer->pages);
> >> +       /* release memory */
> >> +       cma_release(cma_heap->cma, pages, nr_pages);
> >> +       kfree(buffer);
> >> +}
> >> +
> >> +/* dmabuf heap CMA operations functions */
> >> +static int cma_heap_allocate(struct dma_heap *heap,
> >> +                               unsigned long len,
> >> +                               unsigned long flags)
> >> +{
> >> +       struct cma_heap *cma_heap = dma_heap_get_data(heap);
> >> +       struct heap_helper_buffer *helper_buffer;
> >> +       struct page *pages;
> >> +       size_t size = PAGE_ALIGN(len);
> >> +       unsigned long nr_pages = size >> PAGE_SHIFT;
> >> +       unsigned long align = get_order(size);
> >> +       DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
> >> +       struct dma_buf *dmabuf;
> >> +       int ret = -ENOMEM;
> >> +       pgoff_t pg;
> >> +
> >> +       if (align > CONFIG_CMA_ALIGNMENT)
> >> +               align = CONFIG_CMA_ALIGNMENT;
> >> +
> >> +       helper_buffer = kzalloc(sizeof(*helper_buffer), GFP_KERNEL);
> >> +       if (!helper_buffer)
> >> +               return -ENOMEM;
> >> +
> >> +       INIT_HEAP_HELPER_BUFFER(helper_buffer, cma_heap_free);
> >> +       helper_buffer->heap_buffer.flags = flags;
> >> +       helper_buffer->heap_buffer.heap = heap;
> >> +       helper_buffer->heap_buffer.size = len;
> >> +
> >> +       pages = cma_alloc(cma_heap->cma, nr_pages, align, false);
> >> +       if (!pages)
> >> +               goto free_buf;
> >> +
> >> +       if (PageHighMem(pages)) {
> >> +               unsigned long nr_clear_pages = nr_pages;
> >> +               struct page *page = pages;
> >> +
> >> +               while (nr_clear_pages > 0) {
> >> +                       void *vaddr = kmap_atomic(page);
> >> +
> >> +                       memset(vaddr, 0, PAGE_SIZE);
> >> +                       kunmap_atomic(vaddr);
> >> +                       page++;
> >> +                       nr_clear_pages--;
> >> +               }
> >> +       } else {
> >> +               memset(page_address(pages), 0, size);
> >> +       }
> >> +
> >> +       helper_buffer->pagecount = nr_pages;
> >> +       helper_buffer->pages = kmalloc_array(helper_buffer->pagecount,
> >> +                                            sizeof(*helper_buffer->pages),
> >> +                                            GFP_KERNEL);
> >> +       if (!helper_buffer->pages) {
> >> +               ret = -ENOMEM;
> >> +               goto free_cma;
> >> +       }
> >> +
> >> +       for (pg = 0; pg < helper_buffer->pagecount; pg++) {
> >> +               helper_buffer->pages[pg] = &pages[pg];
> >> +               if (!helper_buffer->pages[pg])
> >> +                       goto free_pages;
> >> +       }
> >> +
> >> +       /* create the dmabuf */
> >> +       exp_info.ops = &heap_helper_ops;
> >> +       exp_info.size = len;
> >> +       exp_info.flags = O_RDWR;
> >
> > I think that the flags should be provided when requesting the allocation
> > like it is done in DRM or V4L2.
> > For me DMA_HEAP_VALID_FLAGS = (O_CLOEXEC | O_ACCMODE).
> >
>
>
> So something like done in udmabuf?
>
> https://elixir.bootlin.com/linux/v5.1-rc1/source/include/uapi/linux/udmabuf.h#L8
>
> I think that can be arranged.

I have in mind what is done by DRM:
https://elixir.bootlin.com/linux/v5.1-rc1/source/include/uapi/drm/drm.h#L707

V4L2 does the same but without redefine the flags (which is better)

Benjamin

>
> John,
>
> This might be a good reason to move the dma_buf_fd() call below out of
> the heap and back into the core. That way the file exporting flags can
> be common and core handled. I don't think it would complicate the error
> handling any as we only need to dma_buf_put(dmabuf) in the core on
> failure and the heap specific cleanup will happen for us.
>
> Andrew
>
>
> > Benjamin
> >
> > Benjamin
> >
> >> +       exp_info.priv = &helper_buffer->heap_buffer;
> >> +       dmabuf = dma_buf_export(&exp_info);
> >> +       if (IS_ERR(dmabuf)) {
> >> +               ret = PTR_ERR(dmabuf);
> >> +               goto free_pages;
> >> +       }
> >> +
> >> +       helper_buffer->heap_buffer.dmabuf = dmabuf;
> >> +       helper_buffer->priv_virt = pages;
> >> +
> >> +       ret = dma_buf_fd(dmabuf, O_CLOEXEC);
> >> +       if (ret < 0) {
> >> +               dma_buf_put(dmabuf);
> >> +               /* just return, as put will call release and that will free */
> >> +               return ret;
> >> +       }
> >> +
> >> +       return ret;
> >> +
> >> +free_pages:
> >> +       kfree(helper_buffer->pages);
> >> +free_cma:
> >> +       cma_release(cma_heap->cma, pages, nr_pages);
> >> +free_buf:
> >> +       kfree(helper_buffer);
> >> +       return ret;
> >> +}
> >> +
> >> +static struct dma_heap_ops cma_heap_ops = {
> >> +       .allocate = cma_heap_allocate,
> >> +};
> >> +
> >> +static int __add_cma_heap(struct cma *cma, void *data)
> >> +{
> >> +       struct cma_heap *cma_heap;
> >> +       struct dma_heap_export_info exp_info;
> >> +
> >> +       cma_heap = kzalloc(sizeof(*cma_heap), GFP_KERNEL);
> >> +       if (!cma_heap)
> >> +               return -ENOMEM;
> >> +       cma_heap->cma = cma;
> >> +
> >> +       exp_info.name = cma_get_name(cma);
> >> +       exp_info.ops = &cma_heap_ops;
> >> +       exp_info.priv = cma_heap;
> >> +
> >> +       cma_heap->heap = dma_heap_add(&exp_info);
> >> +       if (IS_ERR(cma_heap->heap)) {
> >> +               int ret = PTR_ERR(cma_heap->heap);
> >> +
> >> +               kfree(cma_heap);
> >> +               return ret;
> >> +       }
> >> +
> >> +       return 0;
> >> +}
> >> +
> >> +static int add_cma_heaps(void)
> >> +{
> >> +       cma_for_each_area(__add_cma_heap, NULL);
> >> +       return 0;
> >> +}
> >> +device_initcall(add_cma_heaps);
> >> --
> >> 2.7.4
> >>

Re: [RFC][PATCH 4/6 v3] dma-buf: heaps: Add CMA heap to dmabuf heapss

[Andrew F. Davis]

On 3/29/19 10:30 AM, Benjamin Gaignard wrote:
> Le ven. 29 mars 2019 à 16:19, Andrew F. Davis <afd@ti.com> a écrit :
>>
>> On 3/29/19 9:44 AM, Benjamin Gaignard wrote:
>>> Le ven. 29 mars 2019 à 01:16, John Stultz <john.stultz@linaro.org> a écrit :
>>>>
>>>> This adds a CMA heap, which allows userspace to allocate
>>>> a dma-buf of contiguous memory out of a CMA region.
>>>>
>>>> This code is an evolution of the Android ION implementation, so
>>>> thanks to its original author and maintainters:
>>>>   Benjamin Gaignard, Laura Abbott, and others!
>>>>
>>>> Cc: Laura Abbott <labbott@redhat.com>
>>>> Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
>>>> Cc: Sumit Semwal <sumit.semwal@linaro.org>
>>>> Cc: Liam Mark <lmark@codeaurora.org>
>>>> Cc: Pratik Patel <pratikp@codeaurora.org>
>>>> Cc: Brian Starkey <Brian.Starkey@arm.com>
>>>> Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
>>>> Cc: Sudipto Paul <Sudipto.Paul@arm.com>
>>>> Cc: Andrew F. Davis <afd@ti.com>
>>>> Cc: Xu YiPing <xuyiping@hisilicon.com>
>>>> Cc: "Chenfeng (puck)" <puck.chen@hisilicon.com>
>>>> Cc: butao <butao@hisilicon.com>
>>>> Cc: "Xiaqing (A)" <saberlily.xia@hisilicon.com>
>>>> Cc: Yudongbin <yudongbin@hisilicon.com>
>>>> Cc: Christoph Hellwig <hch@infradead.org>
>>>> Cc: Chenbo Feng <fengc@google.com>
>>>> Cc: Alistair Strachan <astrachan@google.com>
>>>> Cc: dri-devel@lists.freedesktop.org
>>>> Signed-off-by: John Stultz <john.stultz@linaro.org>
>>>> ---
>>>> v2:
>>>> * Switch allocate to return dmabuf fd
>>>> * Simplify init code
>>>> * Checkpatch fixups
>>>> v3:
>>>> * Switch to inline function for to_cma_heap()
>>>> * Minor cleanups suggested by Brian
>>>> * Fold in new registration style from Andrew
>>>> * Folded in changes from Andrew to use simplified page list
>>>>   from the heap helpers
>>>> ---
>>>>  drivers/dma-buf/heaps/Kconfig    |   8 ++
>>>>  drivers/dma-buf/heaps/Makefile   |   1 +
>>>>  drivers/dma-buf/heaps/cma_heap.c | 170 +++++++++++++++++++++++++++++++++++++++
>>>>  3 files changed, 179 insertions(+)
>>>>  create mode 100644 drivers/dma-buf/heaps/cma_heap.c
>>>>
>>>> diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig
>>>> index 2050527..a5eef06 100644
>>>> --- a/drivers/dma-buf/heaps/Kconfig
>>>> +++ b/drivers/dma-buf/heaps/Kconfig
>>>> @@ -4,3 +4,11 @@ config DMABUF_HEAPS_SYSTEM
>>>>         help
>>>>           Choose this option to enable the system dmabuf heap. The system heap
>>>>           is backed by pages from the buddy allocator. If in doubt, say Y.
>>>> +
>>>> +config DMABUF_HEAPS_CMA
>>>> +       bool "DMA-BUF CMA Heap"
>>>> +       depends on DMABUF_HEAPS && DMA_CMA
>>>> +       help
>>>> +         Choose this option to enable dma-buf CMA heap. This heap is backed
>>>> +         by the Contiguous Memory Allocator (CMA). If your system has these
>>>> +         regions, you should say Y here.
>>>> diff --git a/drivers/dma-buf/heaps/Makefile b/drivers/dma-buf/heaps/Makefile
>>>> index d1808ec..6e54cde 100644
>>>> --- a/drivers/dma-buf/heaps/Makefile
>>>> +++ b/drivers/dma-buf/heaps/Makefile
>>>> @@ -1,3 +1,4 @@
>>>>  # SPDX-License-Identifier: GPL-2.0
>>>>  obj-y                                  += heap-helpers.o
>>>>  obj-$(CONFIG_DMABUF_HEAPS_SYSTEM)      += system_heap.o
>>>> +obj-$(CONFIG_DMABUF_HEAPS_CMA)         += cma_heap.o
>>>> diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c
>>>> new file mode 100644
>>>> index 0000000..f4485c60
>>>> --- /dev/null
>>>> +++ b/drivers/dma-buf/heaps/cma_heap.c
>>>> @@ -0,0 +1,170 @@
>>>> +// SPDX-License-Identifier: GPL-2.0
>>>> +/*
>>>> + * DMABUF CMA heap exporter
>>>> + *
>>>> + * Copyright (C) 2012, 2019 Linaro Ltd.
>>>> + * Author: <benjamin.gaignard@linaro.org> for ST-Ericsson.
>>>> + */
>>>> +
>>>> +#include <linux/device.h>
>>>> +#include <linux/dma-buf.h>
>>>> +#include <linux/dma-heap.h>
>>>> +#include <linux/slab.h>
>>>> +#include <linux/errno.h>
>>>> +#include <linux/err.h>
>>>> +#include <linux/cma.h>
>>>> +#include <linux/scatterlist.h>
>>>> +#include <linux/highmem.h>
>>>> +
>>>> +#include "heap-helpers.h"
>>>> +
>>>> +struct cma_heap {
>>>> +       struct dma_heap *heap;
>>>> +       struct cma *cma;
>>>> +};
>>>> +
>>>> +static void cma_heap_free(struct heap_helper_buffer *buffer)
>>>> +{
>>>> +       struct cma_heap *cma_heap = dma_heap_get_data(buffer->heap_buffer.heap);
>>>> +       struct page *pages = buffer->priv_virt;
>>>> +       unsigned long nr_pages;
>>>> +
>>>> +       nr_pages = buffer->heap_buffer.size >> PAGE_SHIFT;
>>>> +
>>>> +       /* free page list */
>>>> +       kfree(buffer->pages);
>>>> +       /* release memory */
>>>> +       cma_release(cma_heap->cma, pages, nr_pages);
>>>> +       kfree(buffer);
>>>> +}
>>>> +
>>>> +/* dmabuf heap CMA operations functions */
>>>> +static int cma_heap_allocate(struct dma_heap *heap,
>>>> +                               unsigned long len,
>>>> +                               unsigned long flags)
>>>> +{
>>>> +       struct cma_heap *cma_heap = dma_heap_get_data(heap);
>>>> +       struct heap_helper_buffer *helper_buffer;
>>>> +       struct page *pages;
>>>> +       size_t size = PAGE_ALIGN(len);
>>>> +       unsigned long nr_pages = size >> PAGE_SHIFT;
>>>> +       unsigned long align = get_order(size);
>>>> +       DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
>>>> +       struct dma_buf *dmabuf;
>>>> +       int ret = -ENOMEM;
>>>> +       pgoff_t pg;
>>>> +
>>>> +       if (align > CONFIG_CMA_ALIGNMENT)
>>>> +               align = CONFIG_CMA_ALIGNMENT;
>>>> +
>>>> +       helper_buffer = kzalloc(sizeof(*helper_buffer), GFP_KERNEL);
>>>> +       if (!helper_buffer)
>>>> +               return -ENOMEM;
>>>> +
>>>> +       INIT_HEAP_HELPER_BUFFER(helper_buffer, cma_heap_free);
>>>> +       helper_buffer->heap_buffer.flags = flags;
>>>> +       helper_buffer->heap_buffer.heap = heap;
>>>> +       helper_buffer->heap_buffer.size = len;
>>>> +
>>>> +       pages = cma_alloc(cma_heap->cma, nr_pages, align, false);
>>>> +       if (!pages)
>>>> +               goto free_buf;
>>>> +
>>>> +       if (PageHighMem(pages)) {
>>>> +               unsigned long nr_clear_pages = nr_pages;
>>>> +               struct page *page = pages;
>>>> +
>>>> +               while (nr_clear_pages > 0) {
>>>> +                       void *vaddr = kmap_atomic(page);
>>>> +
>>>> +                       memset(vaddr, 0, PAGE_SIZE);
>>>> +                       kunmap_atomic(vaddr);
>>>> +                       page++;
>>>> +                       nr_clear_pages--;
>>>> +               }
>>>> +       } else {
>>>> +               memset(page_address(pages), 0, size);
>>>> +       }
>>>> +
>>>> +       helper_buffer->pagecount = nr_pages;
>>>> +       helper_buffer->pages = kmalloc_array(helper_buffer->pagecount,
>>>> +                                            sizeof(*helper_buffer->pages),
>>>> +                                            GFP_KERNEL);
>>>> +       if (!helper_buffer->pages) {
>>>> +               ret = -ENOMEM;
>>>> +               goto free_cma;
>>>> +       }
>>>> +
>>>> +       for (pg = 0; pg < helper_buffer->pagecount; pg++) {
>>>> +               helper_buffer->pages[pg] = &pages[pg];
>>>> +               if (!helper_buffer->pages[pg])
>>>> +                       goto free_pages;
>>>> +       }
>>>> +
>>>> +       /* create the dmabuf */
>>>> +       exp_info.ops = &heap_helper_ops;
>>>> +       exp_info.size = len;
>>>> +       exp_info.flags = O_RDWR;
>>>
>>> I think that the flags should be provided when requesting the allocation
>>> like it is done in DRM or V4L2.
>>> For me DMA_HEAP_VALID_FLAGS = (O_CLOEXEC | O_ACCMODE).
>>>
>>
>>
>> So something like done in udmabuf?
>>
>> https://elixir.bootlin.com/linux/v5.1-rc1/source/include/uapi/linux/udmabuf.h#L8
>>
>> I think that can be arranged.
> 
> I have in mind what is done by DRM:
> https://elixir.bootlin.com/linux/v5.1-rc1/source/include/uapi/drm/drm.h#L707
> 
> V4L2 does the same but without redefine the flags (which is better)
> 

That would mean we would need a whole flag word passed in just for file
flags when I only ever see one bit being useful(O_CLOEXEC or not). Do
you see any situation where we need more than default O_RDWR and
optional O_CLOEXEC for a dma-buf file?

Andrew

> Benjamin
> 
>>
>> John,
>>
>> This might be a good reason to move the dma_buf_fd() call below out of
>> the heap and back into the core. That way the file exporting flags can
>> be common and core handled. I don't think it would complicate the error
>> handling any as we only need to dma_buf_put(dmabuf) in the core on
>> failure and the heap specific cleanup will happen for us.
>>
>> Andrew
>>
>>
>>> Benjamin
>>>
>>> Benjamin
>>>
>>>> +       exp_info.priv = &helper_buffer->heap_buffer;
>>>> +       dmabuf = dma_buf_export(&exp_info);
>>>> +       if (IS_ERR(dmabuf)) {
>>>> +               ret = PTR_ERR(dmabuf);
>>>> +               goto free_pages;
>>>> +       }
>>>> +
>>>> +       helper_buffer->heap_buffer.dmabuf = dmabuf;
>>>> +       helper_buffer->priv_virt = pages;
>>>> +
>>>> +       ret = dma_buf_fd(dmabuf, O_CLOEXEC);
>>>> +       if (ret < 0) {
>>>> +               dma_buf_put(dmabuf);
>>>> +               /* just return, as put will call release and that will free */
>>>> +               return ret;
>>>> +       }
>>>> +
>>>> +       return ret;
>>>> +
>>>> +free_pages:
>>>> +       kfree(helper_buffer->pages);
>>>> +free_cma:
>>>> +       cma_release(cma_heap->cma, pages, nr_pages);
>>>> +free_buf:
>>>> +       kfree(helper_buffer);
>>>> +       return ret;
>>>> +}
>>>> +
>>>> +static struct dma_heap_ops cma_heap_ops = {
>>>> +       .allocate = cma_heap_allocate,
>>>> +};
>>>> +
>>>> +static int __add_cma_heap(struct cma *cma, void *data)
>>>> +{
>>>> +       struct cma_heap *cma_heap;
>>>> +       struct dma_heap_export_info exp_info;
>>>> +
>>>> +       cma_heap = kzalloc(sizeof(*cma_heap), GFP_KERNEL);
>>>> +       if (!cma_heap)
>>>> +               return -ENOMEM;
>>>> +       cma_heap->cma = cma;
>>>> +
>>>> +       exp_info.name = cma_get_name(cma);
>>>> +       exp_info.ops = &cma_heap_ops;
>>>> +       exp_info.priv = cma_heap;
>>>> +
>>>> +       cma_heap->heap = dma_heap_add(&exp_info);
>>>> +       if (IS_ERR(cma_heap->heap)) {
>>>> +               int ret = PTR_ERR(cma_heap->heap);
>>>> +
>>>> +               kfree(cma_heap);
>>>> +               return ret;
>>>> +       }
>>>> +
>>>> +       return 0;
>>>> +}
>>>> +
>>>> +static int add_cma_heaps(void)
>>>> +{
>>>> +       cma_for_each_area(__add_cma_heap, NULL);
>>>> +       return 0;
>>>> +}
>>>> +device_initcall(add_cma_heaps);
>>>> --
>>>> 2.7.4
>>>>

Re: [RFC][PATCH 4/6 v3] dma-buf: heaps: Add CMA heap to dmabuf heapss

[Andrew F. Davis]

On 3/29/19 10:30 AM, Benjamin Gaignard wrote:
> Le ven. 29 mars 2019 à 16:19, Andrew F. Davis <afd@ti.com> a écrit :
>>
>> On 3/29/19 9:44 AM, Benjamin Gaignard wrote:
>>> Le ven. 29 mars 2019 à 01:16, John Stultz <john.stultz@linaro.org> a écrit :
>>>>
>>>> This adds a CMA heap, which allows userspace to allocate
>>>> a dma-buf of contiguous memory out of a CMA region.
>>>>
>>>> This code is an evolution of the Android ION implementation, so
>>>> thanks to its original author and maintainters:
>>>>   Benjamin Gaignard, Laura Abbott, and others!
>>>>
>>>> Cc: Laura Abbott <labbott@redhat.com>
>>>> Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
>>>> Cc: Sumit Semwal <sumit.semwal@linaro.org>
>>>> Cc: Liam Mark <lmark@codeaurora.org>
>>>> Cc: Pratik Patel <pratikp@codeaurora.org>
>>>> Cc: Brian Starkey <Brian.Starkey@arm.com>
>>>> Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
>>>> Cc: Sudipto Paul <Sudipto.Paul@arm.com>
>>>> Cc: Andrew F. Davis <afd@ti.com>
>>>> Cc: Xu YiPing <xuyiping@hisilicon.com>
>>>> Cc: "Chenfeng (puck)" <puck.chen@hisilicon.com>
>>>> Cc: butao <butao@hisilicon.com>
>>>> Cc: "Xiaqing (A)" <saberlily.xia@hisilicon.com>
>>>> Cc: Yudongbin <yudongbin@hisilicon.com>
>>>> Cc: Christoph Hellwig <hch@infradead.org>
>>>> Cc: Chenbo Feng <fengc@google.com>
>>>> Cc: Alistair Strachan <astrachan@google.com>
>>>> Cc: dri-devel@lists.freedesktop.org
>>>> Signed-off-by: John Stultz <john.stultz@linaro.org>
>>>> ---
>>>> v2:
>>>> * Switch allocate to return dmabuf fd
>>>> * Simplify init code
>>>> * Checkpatch fixups
>>>> v3:
>>>> * Switch to inline function for to_cma_heap()
>>>> * Minor cleanups suggested by Brian
>>>> * Fold in new registration style from Andrew
>>>> * Folded in changes from Andrew to use simplified page list
>>>>   from the heap helpers
>>>> ---
>>>>  drivers/dma-buf/heaps/Kconfig    |   8 ++
>>>>  drivers/dma-buf/heaps/Makefile   |   1 +
>>>>  drivers/dma-buf/heaps/cma_heap.c | 170 +++++++++++++++++++++++++++++++++++++++
>>>>  3 files changed, 179 insertions(+)
>>>>  create mode 100644 drivers/dma-buf/heaps/cma_heap.c
>>>>
>>>> diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig
>>>> index 2050527..a5eef06 100644
>>>> --- a/drivers/dma-buf/heaps/Kconfig
>>>> +++ b/drivers/dma-buf/heaps/Kconfig
>>>> @@ -4,3 +4,11 @@ config DMABUF_HEAPS_SYSTEM
>>>>         help
>>>>           Choose this option to enable the system dmabuf heap. The system heap
>>>>           is backed by pages from the buddy allocator. If in doubt, say Y.
>>>> +
>>>> +config DMABUF_HEAPS_CMA
>>>> +       bool "DMA-BUF CMA Heap"
>>>> +       depends on DMABUF_HEAPS && DMA_CMA
>>>> +       help
>>>> +         Choose this option to enable dma-buf CMA heap. This heap is backed
>>>> +         by the Contiguous Memory Allocator (CMA). If your system has these
>>>> +         regions, you should say Y here.
>>>> diff --git a/drivers/dma-buf/heaps/Makefile b/drivers/dma-buf/heaps/Makefile
>>>> index d1808ec..6e54cde 100644
>>>> --- a/drivers/dma-buf/heaps/Makefile
>>>> +++ b/drivers/dma-buf/heaps/Makefile
>>>> @@ -1,3 +1,4 @@
>>>>  # SPDX-License-Identifier: GPL-2.0
>>>>  obj-y                                  += heap-helpers.o
>>>>  obj-$(CONFIG_DMABUF_HEAPS_SYSTEM)      += system_heap.o
>>>> +obj-$(CONFIG_DMABUF_HEAPS_CMA)         += cma_heap.o
>>>> diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c
>>>> new file mode 100644
>>>> index 0000000..f4485c60
>>>> --- /dev/null
>>>> +++ b/drivers/dma-buf/heaps/cma_heap.c
>>>> @@ -0,0 +1,170 @@
>>>> +// SPDX-License-Identifier: GPL-2.0
>>>> +/*
>>>> + * DMABUF CMA heap exporter
>>>> + *
>>>> + * Copyright (C) 2012, 2019 Linaro Ltd.
>>>> + * Author: <benjamin.gaignard@linaro.org> for ST-Ericsson.
>>>> + */
>>>> +
>>>> +#include <linux/device.h>
>>>> +#include <linux/dma-buf.h>
>>>> +#include <linux/dma-heap.h>
>>>> +#include <linux/slab.h>
>>>> +#include <linux/errno.h>
>>>> +#include <linux/err.h>
>>>> +#include <linux/cma.h>
>>>> +#include <linux/scatterlist.h>
>>>> +#include <linux/highmem.h>
>>>> +
>>>> +#include "heap-helpers.h"
>>>> +
>>>> +struct cma_heap {
>>>> +       struct dma_heap *heap;
>>>> +       struct cma *cma;
>>>> +};
>>>> +
>>>> +static void cma_heap_free(struct heap_helper_buffer *buffer)
>>>> +{
>>>> +       struct cma_heap *cma_heap = dma_heap_get_data(buffer->heap_buffer.heap);
>>>> +       struct page *pages = buffer->priv_virt;
>>>> +       unsigned long nr_pages;
>>>> +
>>>> +       nr_pages = buffer->heap_buffer.size >> PAGE_SHIFT;
>>>> +
>>>> +       /* free page list */
>>>> +       kfree(buffer->pages);
>>>> +       /* release memory */
>>>> +       cma_release(cma_heap->cma, pages, nr_pages);
>>>> +       kfree(buffer);
>>>> +}
>>>> +
>>>> +/* dmabuf heap CMA operations functions */
>>>> +static int cma_heap_allocate(struct dma_heap *heap,
>>>> +                               unsigned long len,
>>>> +                               unsigned long flags)
>>>> +{
>>>> +       struct cma_heap *cma_heap = dma_heap_get_data(heap);
>>>> +       struct heap_helper_buffer *helper_buffer;
>>>> +       struct page *pages;
>>>> +       size_t size = PAGE_ALIGN(len);
>>>> +       unsigned long nr_pages = size >> PAGE_SHIFT;
>>>> +       unsigned long align = get_order(size);
>>>> +       DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
>>>> +       struct dma_buf *dmabuf;
>>>> +       int ret = -ENOMEM;
>>>> +       pgoff_t pg;
>>>> +
>>>> +       if (align > CONFIG_CMA_ALIGNMENT)
>>>> +               align = CONFIG_CMA_ALIGNMENT;
>>>> +
>>>> +       helper_buffer = kzalloc(sizeof(*helper_buffer), GFP_KERNEL);
>>>> +       if (!helper_buffer)
>>>> +               return -ENOMEM;
>>>> +
>>>> +       INIT_HEAP_HELPER_BUFFER(helper_buffer, cma_heap_free);
>>>> +       helper_buffer->heap_buffer.flags = flags;
>>>> +       helper_buffer->heap_buffer.heap = heap;
>>>> +       helper_buffer->heap_buffer.size = len;
>>>> +
>>>> +       pages = cma_alloc(cma_heap->cma, nr_pages, align, false);
>>>> +       if (!pages)
>>>> +               goto free_buf;
>>>> +
>>>> +       if (PageHighMem(pages)) {
>>>> +               unsigned long nr_clear_pages = nr_pages;
>>>> +               struct page *page = pages;
>>>> +
>>>> +               while (nr_clear_pages > 0) {
>>>> +                       void *vaddr = kmap_atomic(page);
>>>> +
>>>> +                       memset(vaddr, 0, PAGE_SIZE);
>>>> +                       kunmap_atomic(vaddr);
>>>> +                       page++;
>>>> +                       nr_clear_pages--;
>>>> +               }
>>>> +       } else {
>>>> +               memset(page_address(pages), 0, size);
>>>> +       }
>>>> +
>>>> +       helper_buffer->pagecount = nr_pages;
>>>> +       helper_buffer->pages = kmalloc_array(helper_buffer->pagecount,
>>>> +                                            sizeof(*helper_buffer->pages),
>>>> +                                            GFP_KERNEL);
>>>> +       if (!helper_buffer->pages) {
>>>> +               ret = -ENOMEM;
>>>> +               goto free_cma;
>>>> +       }
>>>> +
>>>> +       for (pg = 0; pg < helper_buffer->pagecount; pg++) {
>>>> +               helper_buffer->pages[pg] = &pages[pg];
>>>> +               if (!helper_buffer->pages[pg])
>>>> +                       goto free_pages;
>>>> +       }
>>>> +
>>>> +       /* create the dmabuf */
>>>> +       exp_info.ops = &heap_helper_ops;
>>>> +       exp_info.size = len;
>>>> +       exp_info.flags = O_RDWR;
>>>
>>> I think that the flags should be provided when requesting the allocation
>>> like it is done in DRM or V4L2.
>>> For me DMA_HEAP_VALID_FLAGS = (O_CLOEXEC | O_ACCMODE).
>>>
>>
>>
>> So something like done in udmabuf?
>>
>> https://elixir.bootlin.com/linux/v5.1-rc1/source/include/uapi/linux/udmabuf.h#L8
>>
>> I think that can be arranged.
> 
> I have in mind what is done by DRM:
> https://elixir.bootlin.com/linux/v5.1-rc1/source/include/uapi/drm/drm.h#L707
> 
> V4L2 does the same but without redefine the flags (which is better)
> 

That would mean we would need a whole flag word passed in just for file
flags when I only ever see one bit being useful(O_CLOEXEC or not). Do
you see any situation where we need more than default O_RDWR and
optional O_CLOEXEC for a dma-buf file?

Andrew

> Benjamin
> 
>>
>> John,
>>
>> This might be a good reason to move the dma_buf_fd() call below out of
>> the heap and back into the core. That way the file exporting flags can
>> be common and core handled. I don't think it would complicate the error
>> handling any as we only need to dma_buf_put(dmabuf) in the core on
>> failure and the heap specific cleanup will happen for us.
>>
>> Andrew
>>
>>
>>> Benjamin
>>>
>>> Benjamin
>>>
>>>> +       exp_info.priv = &helper_buffer->heap_buffer;
>>>> +       dmabuf = dma_buf_export(&exp_info);
>>>> +       if (IS_ERR(dmabuf)) {
>>>> +               ret = PTR_ERR(dmabuf);
>>>> +               goto free_pages;
>>>> +       }
>>>> +
>>>> +       helper_buffer->heap_buffer.dmabuf = dmabuf;
>>>> +       helper_buffer->priv_virt = pages;
>>>> +
>>>> +       ret = dma_buf_fd(dmabuf, O_CLOEXEC);
>>>> +       if (ret < 0) {
>>>> +               dma_buf_put(dmabuf);
>>>> +               /* just return, as put will call release and that will free */
>>>> +               return ret;
>>>> +       }
>>>> +
>>>> +       return ret;
>>>> +
>>>> +free_pages:
>>>> +       kfree(helper_buffer->pages);
>>>> +free_cma:
>>>> +       cma_release(cma_heap->cma, pages, nr_pages);
>>>> +free_buf:
>>>> +       kfree(helper_buffer);
>>>> +       return ret;
>>>> +}
>>>> +
>>>> +static struct dma_heap_ops cma_heap_ops = {
>>>> +       .allocate = cma_heap_allocate,
>>>> +};
>>>> +
>>>> +static int __add_cma_heap(struct cma *cma, void *data)
>>>> +{
>>>> +       struct cma_heap *cma_heap;
>>>> +       struct dma_heap_export_info exp_info;
>>>> +
>>>> +       cma_heap = kzalloc(sizeof(*cma_heap), GFP_KERNEL);
>>>> +       if (!cma_heap)
>>>> +               return -ENOMEM;
>>>> +       cma_heap->cma = cma;
>>>> +
>>>> +       exp_info.name = cma_get_name(cma);
>>>> +       exp_info.ops = &cma_heap_ops;
>>>> +       exp_info.priv = cma_heap;
>>>> +
>>>> +       cma_heap->heap = dma_heap_add(&exp_info);
>>>> +       if (IS_ERR(cma_heap->heap)) {
>>>> +               int ret = PTR_ERR(cma_heap->heap);
>>>> +
>>>> +               kfree(cma_heap);
>>>> +               return ret;
>>>> +       }
>>>> +
>>>> +       return 0;
>>>> +}
>>>> +
>>>> +static int add_cma_heaps(void)
>>>> +{
>>>> +       cma_for_each_area(__add_cma_heap, NULL);
>>>> +       return 0;
>>>> +}
>>>> +device_initcall(add_cma_heaps);
>>>> --
>>>> 2.7.4
>>>>
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Re: [RFC][PATCH 4/6 v3] dma-buf: heaps: Add CMA heap to dmabuf heapss

[Andrew F. Davis]

On 3/28/19 7:16 PM, John Stultz wrote:
> This adds a CMA heap, which allows userspace to allocate
> a dma-buf of contiguous memory out of a CMA region.
> 
> This code is an evolution of the Android ION implementation, so
> thanks to its original author and maintainters:
>   Benjamin Gaignard, Laura Abbott, and others!
> 
> Cc: Laura Abbott <labbott@redhat.com>
> Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
> Cc: Sumit Semwal <sumit.semwal@linaro.org>
> Cc: Liam Mark <lmark@codeaurora.org>
> Cc: Pratik Patel <pratikp@codeaurora.org>
> Cc: Brian Starkey <Brian.Starkey@arm.com>
> Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
> Cc: Sudipto Paul <Sudipto.Paul@arm.com>
> Cc: Andrew F. Davis <afd@ti.com>
> Cc: Xu YiPing <xuyiping@hisilicon.com>
> Cc: "Chenfeng (puck)" <puck.chen@hisilicon.com>
> Cc: butao <butao@hisilicon.com>
> Cc: "Xiaqing (A)" <saberlily.xia@hisilicon.com>
> Cc: Yudongbin <yudongbin@hisilicon.com>
> Cc: Christoph Hellwig <hch@infradead.org>
> Cc: Chenbo Feng <fengc@google.com>
> Cc: Alistair Strachan <astrachan@google.com>
> Cc: dri-devel@lists.freedesktop.org
> Signed-off-by: John Stultz <john.stultz@linaro.org>
> ---
> v2:
> * Switch allocate to return dmabuf fd
> * Simplify init code
> * Checkpatch fixups
> v3:
> * Switch to inline function for to_cma_heap()
> * Minor cleanups suggested by Brian
> * Fold in new registration style from Andrew
> * Folded in changes from Andrew to use simplified page list
>   from the heap helpers
> ---
>  drivers/dma-buf/heaps/Kconfig    |   8 ++
>  drivers/dma-buf/heaps/Makefile   |   1 +
>  drivers/dma-buf/heaps/cma_heap.c | 170 +++++++++++++++++++++++++++++++++++++++
>  3 files changed, 179 insertions(+)
>  create mode 100644 drivers/dma-buf/heaps/cma_heap.c
> 
> diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig
> index 2050527..a5eef06 100644
> --- a/drivers/dma-buf/heaps/Kconfig
> +++ b/drivers/dma-buf/heaps/Kconfig
> @@ -4,3 +4,11 @@ config DMABUF_HEAPS_SYSTEM
>  	help
>  	  Choose this option to enable the system dmabuf heap. The system heap
>  	  is backed by pages from the buddy allocator. If in doubt, say Y.
> +
> +config DMABUF_HEAPS_CMA
> +	bool "DMA-BUF CMA Heap"
> +	depends on DMABUF_HEAPS && DMA_CMA
> +	help
> +	  Choose this option to enable dma-buf CMA heap. This heap is backed
> +	  by the Contiguous Memory Allocator (CMA). If your system has these
> +	  regions, you should say Y here.
> diff --git a/drivers/dma-buf/heaps/Makefile b/drivers/dma-buf/heaps/Makefile
> index d1808ec..6e54cde 100644
> --- a/drivers/dma-buf/heaps/Makefile
> +++ b/drivers/dma-buf/heaps/Makefile
> @@ -1,3 +1,4 @@
>  # SPDX-License-Identifier: GPL-2.0
>  obj-y					+= heap-helpers.o
>  obj-$(CONFIG_DMABUF_HEAPS_SYSTEM)	+= system_heap.o
> +obj-$(CONFIG_DMABUF_HEAPS_CMA)		+= cma_heap.o
> diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c
> new file mode 100644
> index 0000000..f4485c60
> --- /dev/null
> +++ b/drivers/dma-buf/heaps/cma_heap.c
> @@ -0,0 +1,170 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * DMABUF CMA heap exporter
> + *
> + * Copyright (C) 2012, 2019 Linaro Ltd.
> + * Author: <benjamin.gaignard@linaro.org> for ST-Ericsson.
> + */
> +
> +#include <linux/device.h>
> +#include <linux/dma-buf.h>
> +#include <linux/dma-heap.h>
> +#include <linux/slab.h>
> +#include <linux/errno.h>
> +#include <linux/err.h>
> +#include <linux/cma.h>
> +#include <linux/scatterlist.h>
> +#include <linux/highmem.h>
> +
> +#include "heap-helpers.h"
> +
> +struct cma_heap {
> +	struct dma_heap *heap;
> +	struct cma *cma;
> +};
> +
> +static void cma_heap_free(struct heap_helper_buffer *buffer)
> +{
> +	struct cma_heap *cma_heap = dma_heap_get_data(buffer->heap_buffer.heap);
> +	struct page *pages = buffer->priv_virt;
> +	unsigned long nr_pages;
> +
> +	nr_pages = buffer->heap_buffer.size >> PAGE_SHIFT;

Could also use the count in helper_buffer->pagecount.

> +
> +	/* free page list */
> +	kfree(buffer->pages);
> +	/* release memory */
> +	cma_release(cma_heap->cma, pages, nr_pages);
> +	kfree(buffer);
> +}
> +
> +/* dmabuf heap CMA operations functions */
> +static int cma_heap_allocate(struct dma_heap *heap,
> +				unsigned long len,
> +				unsigned long flags)
> +{
> +	struct cma_heap *cma_heap = dma_heap_get_data(heap);
> +	struct heap_helper_buffer *helper_buffer;
> +	struct page *pages;
> +	size_t size = PAGE_ALIGN(len);
> +	unsigned long nr_pages = size >> PAGE_SHIFT;
> +	unsigned long align = get_order(size);
> +	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
> +	struct dma_buf *dmabuf;
> +	int ret = -ENOMEM;
> +	pgoff_t pg;
> +
> +	if (align > CONFIG_CMA_ALIGNMENT)
> +		align = CONFIG_CMA_ALIGNMENT;
> +
> +	helper_buffer = kzalloc(sizeof(*helper_buffer), GFP_KERNEL);
> +	if (!helper_buffer)
> +		return -ENOMEM;
> +
> +	INIT_HEAP_HELPER_BUFFER(helper_buffer, cma_heap_free);
> +	helper_buffer->heap_buffer.flags = flags;
> +	helper_buffer->heap_buffer.heap = heap;
> +	helper_buffer->heap_buffer.size = len;
> +
> +	pages = cma_alloc(cma_heap->cma, nr_pages, align, false);
> +	if (!pages)
> +		goto free_buf;
> +
> +	if (PageHighMem(pages)) {

Can the allocated pages list cross the high mem line?

If so then:

foreach(nr_pages) {
	if (PageHighMem(page))
		clear_highpage(page);
	else
		clear_page(page_address(page));
}

If not still should use clear_highpage() below.

Andrew

> +		unsigned long nr_clear_pages = nr_pages;
> +		struct page *page = pages;
> +
> +		while (nr_clear_pages > 0) {
> +			void *vaddr = kmap_atomic(page);
> +
> +			memset(vaddr, 0, PAGE_SIZE);
> +			kunmap_atomic(vaddr);
> +			page++;
> +			nr_clear_pages--;
> +		}
> +	} else {
> +		memset(page_address(pages), 0, size);
> +	}
> +
> +	helper_buffer->pagecount = nr_pages;
> +	helper_buffer->pages = kmalloc_array(helper_buffer->pagecount,
> +					     sizeof(*helper_buffer->pages),
> +					     GFP_KERNEL);
> +	if (!helper_buffer->pages) {
> +		ret = -ENOMEM;
> +		goto free_cma;
> +	}
> +
> +	for (pg = 0; pg < helper_buffer->pagecount; pg++) {
> +		helper_buffer->pages[pg] = &pages[pg];
> +		if (!helper_buffer->pages[pg])
> +			goto free_pages;
> +	}
> +
> +	/* create the dmabuf */
> +	exp_info.ops = &heap_helper_ops;
> +	exp_info.size = len;
> +	exp_info.flags = O_RDWR;
> +	exp_info.priv = &helper_buffer->heap_buffer;
> +	dmabuf = dma_buf_export(&exp_info);
> +	if (IS_ERR(dmabuf)) {
> +		ret = PTR_ERR(dmabuf);
> +		goto free_pages;
> +	}
> +
> +	helper_buffer->heap_buffer.dmabuf = dmabuf;
> +	helper_buffer->priv_virt = pages;
> +
> +	ret = dma_buf_fd(dmabuf, O_CLOEXEC);
> +	if (ret < 0) {
> +		dma_buf_put(dmabuf);
> +		/* just return, as put will call release and that will free */
> +		return ret;
> +	}
> +
> +	return ret;
> +
> +free_pages:
> +	kfree(helper_buffer->pages);
> +free_cma:
> +	cma_release(cma_heap->cma, pages, nr_pages);
> +free_buf:
> +	kfree(helper_buffer);
> +	return ret;
> +}
> +
> +static struct dma_heap_ops cma_heap_ops = {
> +	.allocate = cma_heap_allocate,
> +};
> +
> +static int __add_cma_heap(struct cma *cma, void *data)
> +{
> +	struct cma_heap *cma_heap;
> +	struct dma_heap_export_info exp_info;
> +
> +	cma_heap = kzalloc(sizeof(*cma_heap), GFP_KERNEL);
> +	if (!cma_heap)
> +		return -ENOMEM;
> +	cma_heap->cma = cma;
> +
> +	exp_info.name = cma_get_name(cma);
> +	exp_info.ops = &cma_heap_ops;
> +	exp_info.priv = cma_heap;
> +
> +	cma_heap->heap = dma_heap_add(&exp_info);
> +	if (IS_ERR(cma_heap->heap)) {
> +		int ret = PTR_ERR(cma_heap->heap);
> +
> +		kfree(cma_heap);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int add_cma_heaps(void)
> +{
> +	cma_for_each_area(__add_cma_heap, NULL);
> +	return 0;
> +}
> +device_initcall(add_cma_heaps);
> 

Re: [RFC][PATCH 4/6 v3] dma-buf: heaps: Add CMA heap to dmabuf heapss

[Andrew F. Davis]

On 3/28/19 7:16 PM, John Stultz wrote:
> This adds a CMA heap, which allows userspace to allocate
> a dma-buf of contiguous memory out of a CMA region.
> 
> This code is an evolution of the Android ION implementation, so
> thanks to its original author and maintainters:
>   Benjamin Gaignard, Laura Abbott, and others!
> 
> Cc: Laura Abbott <labbott@redhat.com>
> Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
> Cc: Sumit Semwal <sumit.semwal@linaro.org>
> Cc: Liam Mark <lmark@codeaurora.org>
> Cc: Pratik Patel <pratikp@codeaurora.org>
> Cc: Brian Starkey <Brian.Starkey@arm.com>
> Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
> Cc: Sudipto Paul <Sudipto.Paul@arm.com>
> Cc: Andrew F. Davis <afd@ti.com>
> Cc: Xu YiPing <xuyiping@hisilicon.com>
> Cc: "Chenfeng (puck)" <puck.chen@hisilicon.com>
> Cc: butao <butao@hisilicon.com>
> Cc: "Xiaqing (A)" <saberlily.xia@hisilicon.com>
> Cc: Yudongbin <yudongbin@hisilicon.com>
> Cc: Christoph Hellwig <hch@infradead.org>
> Cc: Chenbo Feng <fengc@google.com>
> Cc: Alistair Strachan <astrachan@google.com>
> Cc: dri-devel@lists.freedesktop.org
> Signed-off-by: John Stultz <john.stultz@linaro.org>
> ---
> v2:
> * Switch allocate to return dmabuf fd
> * Simplify init code
> * Checkpatch fixups
> v3:
> * Switch to inline function for to_cma_heap()
> * Minor cleanups suggested by Brian
> * Fold in new registration style from Andrew
> * Folded in changes from Andrew to use simplified page list
>   from the heap helpers
> ---
>  drivers/dma-buf/heaps/Kconfig    |   8 ++
>  drivers/dma-buf/heaps/Makefile   |   1 +
>  drivers/dma-buf/heaps/cma_heap.c | 170 +++++++++++++++++++++++++++++++++++++++
>  3 files changed, 179 insertions(+)
>  create mode 100644 drivers/dma-buf/heaps/cma_heap.c
> 
> diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig
> index 2050527..a5eef06 100644
> --- a/drivers/dma-buf/heaps/Kconfig
> +++ b/drivers/dma-buf/heaps/Kconfig
> @@ -4,3 +4,11 @@ config DMABUF_HEAPS_SYSTEM
>  	help
>  	  Choose this option to enable the system dmabuf heap. The system heap
>  	  is backed by pages from the buddy allocator. If in doubt, say Y.
> +
> +config DMABUF_HEAPS_CMA
> +	bool "DMA-BUF CMA Heap"
> +	depends on DMABUF_HEAPS && DMA_CMA
> +	help
> +	  Choose this option to enable dma-buf CMA heap. This heap is backed
> +	  by the Contiguous Memory Allocator (CMA). If your system has these
> +	  regions, you should say Y here.
> diff --git a/drivers/dma-buf/heaps/Makefile b/drivers/dma-buf/heaps/Makefile
> index d1808ec..6e54cde 100644
> --- a/drivers/dma-buf/heaps/Makefile
> +++ b/drivers/dma-buf/heaps/Makefile
> @@ -1,3 +1,4 @@
>  # SPDX-License-Identifier: GPL-2.0
>  obj-y					+= heap-helpers.o
>  obj-$(CONFIG_DMABUF_HEAPS_SYSTEM)	+= system_heap.o
> +obj-$(CONFIG_DMABUF_HEAPS_CMA)		+= cma_heap.o
> diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c
> new file mode 100644
> index 0000000..f4485c60
> --- /dev/null
> +++ b/drivers/dma-buf/heaps/cma_heap.c
> @@ -0,0 +1,170 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * DMABUF CMA heap exporter
> + *
> + * Copyright (C) 2012, 2019 Linaro Ltd.
> + * Author: <benjamin.gaignard@linaro.org> for ST-Ericsson.
> + */
> +
> +#include <linux/device.h>
> +#include <linux/dma-buf.h>
> +#include <linux/dma-heap.h>
> +#include <linux/slab.h>
> +#include <linux/errno.h>
> +#include <linux/err.h>
> +#include <linux/cma.h>
> +#include <linux/scatterlist.h>
> +#include <linux/highmem.h>
> +
> +#include "heap-helpers.h"
> +
> +struct cma_heap {
> +	struct dma_heap *heap;
> +	struct cma *cma;
> +};
> +
> +static void cma_heap_free(struct heap_helper_buffer *buffer)
> +{
> +	struct cma_heap *cma_heap = dma_heap_get_data(buffer->heap_buffer.heap);
> +	struct page *pages = buffer->priv_virt;
> +	unsigned long nr_pages;
> +
> +	nr_pages = buffer->heap_buffer.size >> PAGE_SHIFT;

Could also use the count in helper_buffer->pagecount.

> +
> +	/* free page list */
> +	kfree(buffer->pages);
> +	/* release memory */
> +	cma_release(cma_heap->cma, pages, nr_pages);
> +	kfree(buffer);
> +}
> +
> +/* dmabuf heap CMA operations functions */
> +static int cma_heap_allocate(struct dma_heap *heap,
> +				unsigned long len,
> +				unsigned long flags)
> +{
> +	struct cma_heap *cma_heap = dma_heap_get_data(heap);
> +	struct heap_helper_buffer *helper_buffer;
> +	struct page *pages;
> +	size_t size = PAGE_ALIGN(len);
> +	unsigned long nr_pages = size >> PAGE_SHIFT;
> +	unsigned long align = get_order(size);
> +	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
> +	struct dma_buf *dmabuf;
> +	int ret = -ENOMEM;
> +	pgoff_t pg;
> +
> +	if (align > CONFIG_CMA_ALIGNMENT)
> +		align = CONFIG_CMA_ALIGNMENT;
> +
> +	helper_buffer = kzalloc(sizeof(*helper_buffer), GFP_KERNEL);
> +	if (!helper_buffer)
> +		return -ENOMEM;
> +
> +	INIT_HEAP_HELPER_BUFFER(helper_buffer, cma_heap_free);
> +	helper_buffer->heap_buffer.flags = flags;
> +	helper_buffer->heap_buffer.heap = heap;
> +	helper_buffer->heap_buffer.size = len;
> +
> +	pages = cma_alloc(cma_heap->cma, nr_pages, align, false);
> +	if (!pages)
> +		goto free_buf;
> +
> +	if (PageHighMem(pages)) {

Can the allocated pages list cross the high mem line?

If so then:

foreach(nr_pages) {
	if (PageHighMem(page))
		clear_highpage(page);
	else
		clear_page(page_address(page));
}

If not still should use clear_highpage() below.

Andrew

> +		unsigned long nr_clear_pages = nr_pages;
> +		struct page *page = pages;
> +
> +		while (nr_clear_pages > 0) {
> +			void *vaddr = kmap_atomic(page);
> +
> +			memset(vaddr, 0, PAGE_SIZE);
> +			kunmap_atomic(vaddr);
> +			page++;
> +			nr_clear_pages--;
> +		}
> +	} else {
> +		memset(page_address(pages), 0, size);
> +	}
> +
> +	helper_buffer->pagecount = nr_pages;
> +	helper_buffer->pages = kmalloc_array(helper_buffer->pagecount,
> +					     sizeof(*helper_buffer->pages),
> +					     GFP_KERNEL);
> +	if (!helper_buffer->pages) {
> +		ret = -ENOMEM;
> +		goto free_cma;
> +	}
> +
> +	for (pg = 0; pg < helper_buffer->pagecount; pg++) {
> +		helper_buffer->pages[pg] = &pages[pg];
> +		if (!helper_buffer->pages[pg])
> +			goto free_pages;
> +	}
> +
> +	/* create the dmabuf */
> +	exp_info.ops = &heap_helper_ops;
> +	exp_info.size = len;
> +	exp_info.flags = O_RDWR;
> +	exp_info.priv = &helper_buffer->heap_buffer;
> +	dmabuf = dma_buf_export(&exp_info);
> +	if (IS_ERR(dmabuf)) {
> +		ret = PTR_ERR(dmabuf);
> +		goto free_pages;
> +	}
> +
> +	helper_buffer->heap_buffer.dmabuf = dmabuf;
> +	helper_buffer->priv_virt = pages;
> +
> +	ret = dma_buf_fd(dmabuf, O_CLOEXEC);
> +	if (ret < 0) {
> +		dma_buf_put(dmabuf);
> +		/* just return, as put will call release and that will free */
> +		return ret;
> +	}
> +
> +	return ret;
> +
> +free_pages:
> +	kfree(helper_buffer->pages);
> +free_cma:
> +	cma_release(cma_heap->cma, pages, nr_pages);
> +free_buf:
> +	kfree(helper_buffer);
> +	return ret;
> +}
> +
> +static struct dma_heap_ops cma_heap_ops = {
> +	.allocate = cma_heap_allocate,
> +};
> +
> +static int __add_cma_heap(struct cma *cma, void *data)
> +{
> +	struct cma_heap *cma_heap;
> +	struct dma_heap_export_info exp_info;
> +
> +	cma_heap = kzalloc(sizeof(*cma_heap), GFP_KERNEL);
> +	if (!cma_heap)
> +		return -ENOMEM;
> +	cma_heap->cma = cma;
> +
> +	exp_info.name = cma_get_name(cma);
> +	exp_info.ops = &cma_heap_ops;
> +	exp_info.priv = cma_heap;
> +
> +	cma_heap->heap = dma_heap_add(&exp_info);
> +	if (IS_ERR(cma_heap->heap)) {
> +		int ret = PTR_ERR(cma_heap->heap);
> +
> +		kfree(cma_heap);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int add_cma_heaps(void)
> +{
> +	cma_for_each_area(__add_cma_heap, NULL);
> +	return 0;
> +}
> +device_initcall(add_cma_heaps);
> 
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Re: [RFC][PATCH 0/6 v3] DMA-BUF Heaps (destaging ION)

[Liam Mark]

On Fri, 29 Mar 2019, Andrew F. Davis wrote:

> On 3/28/19 7:15 PM, John Stultz wrote:
> > Here is another RFC of the dma-buf heaps patchset Andrew and I
> > have been working on which tries to destage a fair chunk of ION
> > functionality.
> > 
> > The patchset implements per-heap devices which can be opened
> > directly and then an ioctl is used to allocate a dmabuf from the
> > heap.
> > 
> > The interface is similar, but much simpler then IONs, only
> > providing an ALLOC ioctl.
> > 
> > Also, I've provided simple system and cma heaps. The system
> > heap in particular is missing the page-pool optimizations ION
> > had, but works well enough to validate the interface.
> > 
> > I've booted and tested these patches with AOSP on the HiKey960
> > using the kernel tree here:
> >   https://git.linaro.org/people/john.stultz/android-dev.git/log/?h=dev/dma-buf-heap
> > 
> > And the userspace changes here:
> >   https://android-review.googlesource.com/c/device/linaro/hikey/+/909436
> > 
> > 
> > Compared to ION, this patchset is missing the system-contig,
> > carveout and chunk heaps, as I don't have a device that uses
> > those, so I'm unable to do much useful validation there.
> > Additionally we have no upstream users of chunk or carveout,
> > and the system-contig has been deprecated in the common/andoid-*
> > kernels, so this should be ok.
> > 
> 
> 
> I'd like to go over my use-cases for a moment to see if we can get some
> agreement on what to do with the carveout/chunk heaps.
> 
> We used DRM (omapdrm) to get buffers for display, GPU, and multi-media.
> Our out-of-tree CMEM driver[0] for remote processing (OpenCL/CV/VX)
> buffers. And for secure heaps we use what are basically slightly
> modified ION carveout heaps.
> 
> Now with the DMA-Heap framework what we can do is for sub-systems with
> IOMMUs use 'system' heap (GPU). For those that need contiguous memory
> (display, MM) we have 'cma' heap (and maybe 'system-contig' at some
> point). For our SRAM areas used in remote processing I've posted an RFC
> for a heap[1] to provide allocations from those areas.
> 
> The above leaves one last gap for us, uncached/unmapped areas from
> regular memory. I propose this is where we use the 'carveout' heap.
> Right now to get some contiguous/cached memory with DT you can:
> 
> reserved-memory {
> 	[...]
> 	cma_memory {
> 		compatible = "shared-dma-pool";
> 		reg = <0x79000000 0x400000>;
> 		reusable;
> 	};
> 
> 	coherent_memory@78000000 {
> 		reg = <0x78000000 0x800000>;
> 		no-map;
> 	};
> };
> 
> 'cma_memory' will show up as a 'cma' heap, so all good there.
> 
> Looking at 'coherent_memory' it will not have valid backing 'struct
> page' and so cannot be given cached mappings as the standard dma memory
> ops would fail. This would give this area the right properties for both
> users who don't want to do all the cache maintenance ops (Liam?) and for
> secure heaps that have restrictions on access from Linux running CPU.
> 

So our main use case in which we use uncached memory to avoid cache 
maintenance is for multimedia memory (which is generally only accessed by 
devices), there can be both a lot of this memory allocated for these use 
cases and the amount varies so a carveout wouldn't work for us.
However I am still holding out hope that we will be able to drop this 
requirement for uncached memory through changes to both Android and 
ION/dma-buf heaps, such as the proposal where Android keeps devices 
attached and ION/dma-buf heaps track of which buffers are 'dirty'. 
Investigations still ongoing... 

We have a number of use cases which use uncached memory, the major reason 
that our clients use uncached is for the performance benefit above. I 
am currently doing a review of client use cases to determine all our 
uncached requirements, for example if CMA heaps will need to support 
uncached allocations, once that is done I will be able to better 
articulate our requirements.

One use case where I have seen carveouts uses which doesn't sound like it 
would be supported under the current proposals is when clients need to 
allocate a lot of cached memory quickly.
I have seen cases where a large carveout is used for camera use cases.
Basically they allocate cached memory from the carveout and any extra 
memory they need (after the carveout is full) is allocated from the system 
heap.

This allows for memory heavy performance sensitive apps, such as camera, 
to be launched quickly.

> The question then is how to mark these areas for export with DMA-Heaps?
> Maybe a cma_for_each_area() like function but for dma coherent areas?
> 

That sounds reasonable to me.

> Anyway for now this is not super important and I can post a patchset at
> some later point for this when I get it working and tested internally.
> 
> [0]
> http://software-dl.ti.com/processor-sdk-linux/esd/docs/latest/linux/Foundational_Components_CMEM.html
> [1] https://patchwork.kernel.org/patch/10863957/
> 
> Thanks,
> Andrew
> 
> 
> > I've also removed the stats accounting for now, since it should
> > be implemented by the heaps themselves.
> > 
> > 
> > New in v3:
> > * Proper /dev/heap/* names on both Android and classic Linux
> >   environments
> > * Major rework of the helper code from Andrew
> > * Dummy test device added to test importing
> > * *Lots* of cleanups suggested by many (thank you for all the
> >   input)!
> > 
> > 
> > Outstanding concerns:
> > * Potential need for private flags in interface for secure
> >   heaps. Need to better understand secure heap usage.
> > * Making sure the performance issues from potentially unnecessary
> >   cache-management operations can be resolved properly for system
> >   and cma heaps (outstanding issue from ION).
> > 
> > 
> > Eventual TODOS:
> > * Sanity filtering for heap names
> > * Reimplement performance optimizations for system heap
> > * Add stats accounting to system/cma heaps
> > * Make the kselftest more useful
> > * Add other heaps folks see as useful (would love to get
> >   some help from actual carveout/chunk users)!
> > 
> > That said, the main user-interface is shaping up and I wanted
> > to get some input on the device model (particularly from GreKH)
> > and any other API/ABI specific input. 
> > 
> > thanks
> > -john
> > 
> > Cc: Laura Abbott <labbott@redhat.com>
> > Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
> > Cc: Sumit Semwal <sumit.semwal@linaro.org>
> > Cc: Liam Mark <lmark@codeaurora.org>
> > Cc: Pratik Patel <pratikp@codeaurora.org>
> > Cc: Brian Starkey <Brian.Starkey@arm.com>
> > Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
> > Cc: Sudipto Paul <Sudipto.Paul@arm.com>
> > Cc: Andrew F. Davis <afd@ti.com>
> > Cc: Xu YiPing <xuyiping@hisilicon.com>
> > Cc: "Chenfeng (puck)" <puck.chen@hisilicon.com>
> > Cc: butao <butao@hisilicon.com>
> > Cc: "Xiaqing (A)" <saberlily.xia@hisilicon.com>
> > Cc: Yudongbin <yudongbin@hisilicon.com>
> > Cc: Christoph Hellwig <hch@infradead.org>
> > Cc: Chenbo Feng <fengc@google.com>
> > Cc: Alistair Strachan <astrachan@google.com>
> > Cc: dri-devel@lists.freedesktop.org
> > 
> > Andrew F. Davis (2):
> >   dma-buf: Add dma-buf heaps framework
> >   dma-buf: Add Dummy Importer Test Device
> > 
> > John Stultz (4):
> >   dma-buf: heaps: Add heap helpers
> >   dma-buf: heaps: Add system heap to dmabuf heaps
> >   dma-buf: heaps: Add CMA heap to dmabuf heapss
> >   kselftests: Add dma-heap test
> > 
> >  MAINTAINERS                                        |  18 ++
> >  drivers/dma-buf/Kconfig                            |  16 ++
> >  drivers/dma-buf/Makefile                           |   3 +
> >  drivers/dma-buf/dma-buf-testdev.c                  | 239 +++++++++++++++++++
> >  drivers/dma-buf/dma-heap.c                         | 234 ++++++++++++++++++
> >  drivers/dma-buf/heaps/Kconfig                      |  14 ++
> >  drivers/dma-buf/heaps/Makefile                     |   4 +
> >  drivers/dma-buf/heaps/cma_heap.c                   | 170 ++++++++++++++
> >  drivers/dma-buf/heaps/heap-helpers.c               | 261 +++++++++++++++++++++
> >  drivers/dma-buf/heaps/heap-helpers.h               |  55 +++++
> >  drivers/dma-buf/heaps/system_heap.c                | 120 ++++++++++
> >  include/linux/dma-heap.h                           |  58 +++++
> >  include/uapi/linux/dma-buf-testdev.h               |  37 +++
> >  include/uapi/linux/dma-heap.h                      |  52 ++++
> >  tools/testing/selftests/dmabuf-heaps/Makefile      |  11 +
> >  tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c | 169 +++++++++++++
> >  16 files changed, 1461 insertions(+)
> >  create mode 100644 drivers/dma-buf/dma-buf-testdev.c
> >  create mode 100644 drivers/dma-buf/dma-heap.c
> >  create mode 100644 drivers/dma-buf/heaps/Kconfig
> >  create mode 100644 drivers/dma-buf/heaps/Makefile
> >  create mode 100644 drivers/dma-buf/heaps/cma_heap.c
> >  create mode 100644 drivers/dma-buf/heaps/heap-helpers.c
> >  create mode 100644 drivers/dma-buf/heaps/heap-helpers.h
> >  create mode 100644 drivers/dma-buf/heaps/system_heap.c
> >  create mode 100644 include/linux/dma-heap.h
> >  create mode 100644 include/uapi/linux/dma-buf-testdev.h
> >  create mode 100644 include/uapi/linux/dma-heap.h
> >  create mode 100644 tools/testing/selftests/dmabuf-heaps/Makefile
> >  create mode 100644 tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c
> > 
> 

Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [RFC][PATCH 4/6 v3] dma-buf: heaps: Add CMA heap to dmabuf heapss

[Benjamin Gaignard]

Le ven. 29 mars 2019 à 16:42, Andrew F. Davis <afd@ti.com> a écrit :
>
> On 3/29/19 10:30 AM, Benjamin Gaignard wrote:
> > Le ven. 29 mars 2019 à 16:19, Andrew F. Davis <afd@ti.com> a écrit :
> >>
> >> On 3/29/19 9:44 AM, Benjamin Gaignard wrote:
> >>> Le ven. 29 mars 2019 à 01:16, John Stultz <john.stultz@linaro.org> a écrit :
> >>>>
> >>>> This adds a CMA heap, which allows userspace to allocate
> >>>> a dma-buf of contiguous memory out of a CMA region.
> >>>>
> >>>> This code is an evolution of the Android ION implementation, so
> >>>> thanks to its original author and maintainters:
> >>>>   Benjamin Gaignard, Laura Abbott, and others!
> >>>>
> >>>> Cc: Laura Abbott <labbott@redhat.com>
> >>>> Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
> >>>> Cc: Sumit Semwal <sumit.semwal@linaro.org>
> >>>> Cc: Liam Mark <lmark@codeaurora.org>
> >>>> Cc: Pratik Patel <pratikp@codeaurora.org>
> >>>> Cc: Brian Starkey <Brian.Starkey@arm.com>
> >>>> Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
> >>>> Cc: Sudipto Paul <Sudipto.Paul@arm.com>
> >>>> Cc: Andrew F. Davis <afd@ti.com>
> >>>> Cc: Xu YiPing <xuyiping@hisilicon.com>
> >>>> Cc: "Chenfeng (puck)" <puck.chen@hisilicon.com>
> >>>> Cc: butao <butao@hisilicon.com>
> >>>> Cc: "Xiaqing (A)" <saberlily.xia@hisilicon.com>
> >>>> Cc: Yudongbin <yudongbin@hisilicon.com>
> >>>> Cc: Christoph Hellwig <hch@infradead.org>
> >>>> Cc: Chenbo Feng <fengc@google.com>
> >>>> Cc: Alistair Strachan <astrachan@google.com>
> >>>> Cc: dri-devel@lists.freedesktop.org
> >>>> Signed-off-by: John Stultz <john.stultz@linaro.org>
> >>>> ---
> >>>> v2:
> >>>> * Switch allocate to return dmabuf fd
> >>>> * Simplify init code
> >>>> * Checkpatch fixups
> >>>> v3:
> >>>> * Switch to inline function for to_cma_heap()
> >>>> * Minor cleanups suggested by Brian
> >>>> * Fold in new registration style from Andrew
> >>>> * Folded in changes from Andrew to use simplified page list
> >>>>   from the heap helpers
> >>>> ---
> >>>>  drivers/dma-buf/heaps/Kconfig    |   8 ++
> >>>>  drivers/dma-buf/heaps/Makefile   |   1 +
> >>>>  drivers/dma-buf/heaps/cma_heap.c | 170 +++++++++++++++++++++++++++++++++++++++
> >>>>  3 files changed, 179 insertions(+)
> >>>>  create mode 100644 drivers/dma-buf/heaps/cma_heap.c
> >>>>
> >>>> diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig
> >>>> index 2050527..a5eef06 100644
> >>>> --- a/drivers/dma-buf/heaps/Kconfig
> >>>> +++ b/drivers/dma-buf/heaps/Kconfig
> >>>> @@ -4,3 +4,11 @@ config DMABUF_HEAPS_SYSTEM
> >>>>         help
> >>>>           Choose this option to enable the system dmabuf heap. The system heap
> >>>>           is backed by pages from the buddy allocator. If in doubt, say Y.
> >>>> +
> >>>> +config DMABUF_HEAPS_CMA
> >>>> +       bool "DMA-BUF CMA Heap"
> >>>> +       depends on DMABUF_HEAPS && DMA_CMA
> >>>> +       help
> >>>> +         Choose this option to enable dma-buf CMA heap. This heap is backed
> >>>> +         by the Contiguous Memory Allocator (CMA). If your system has these
> >>>> +         regions, you should say Y here.
> >>>> diff --git a/drivers/dma-buf/heaps/Makefile b/drivers/dma-buf/heaps/Makefile
> >>>> index d1808ec..6e54cde 100644
> >>>> --- a/drivers/dma-buf/heaps/Makefile
> >>>> +++ b/drivers/dma-buf/heaps/Makefile
> >>>> @@ -1,3 +1,4 @@
> >>>>  # SPDX-License-Identifier: GPL-2.0
> >>>>  obj-y                                  += heap-helpers.o
> >>>>  obj-$(CONFIG_DMABUF_HEAPS_SYSTEM)      += system_heap.o
> >>>> +obj-$(CONFIG_DMABUF_HEAPS_CMA)         += cma_heap.o
> >>>> diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c
> >>>> new file mode 100644
> >>>> index 0000000..f4485c60
> >>>> --- /dev/null
> >>>> +++ b/drivers/dma-buf/heaps/cma_heap.c
> >>>> @@ -0,0 +1,170 @@
> >>>> +// SPDX-License-Identifier: GPL-2.0
> >>>> +/*
> >>>> + * DMABUF CMA heap exporter
> >>>> + *
> >>>> + * Copyright (C) 2012, 2019 Linaro Ltd.
> >>>> + * Author: <benjamin.gaignard@linaro.org> for ST-Ericsson.
> >>>> + */
> >>>> +
> >>>> +#include <linux/device.h>
> >>>> +#include <linux/dma-buf.h>
> >>>> +#include <linux/dma-heap.h>
> >>>> +#include <linux/slab.h>
> >>>> +#include <linux/errno.h>
> >>>> +#include <linux/err.h>
> >>>> +#include <linux/cma.h>
> >>>> +#include <linux/scatterlist.h>
> >>>> +#include <linux/highmem.h>
> >>>> +
> >>>> +#include "heap-helpers.h"
> >>>> +
> >>>> +struct cma_heap {
> >>>> +       struct dma_heap *heap;
> >>>> +       struct cma *cma;
> >>>> +};
> >>>> +
> >>>> +static void cma_heap_free(struct heap_helper_buffer *buffer)
> >>>> +{
> >>>> +       struct cma_heap *cma_heap = dma_heap_get_data(buffer->heap_buffer.heap);
> >>>> +       struct page *pages = buffer->priv_virt;
> >>>> +       unsigned long nr_pages;
> >>>> +
> >>>> +       nr_pages = buffer->heap_buffer.size >> PAGE_SHIFT;
> >>>> +
> >>>> +       /* free page list */
> >>>> +       kfree(buffer->pages);
> >>>> +       /* release memory */
> >>>> +       cma_release(cma_heap->cma, pages, nr_pages);
> >>>> +       kfree(buffer);
> >>>> +}
> >>>> +
> >>>> +/* dmabuf heap CMA operations functions */
> >>>> +static int cma_heap_allocate(struct dma_heap *heap,
> >>>> +                               unsigned long len,
> >>>> +                               unsigned long flags)
> >>>> +{
> >>>> +       struct cma_heap *cma_heap = dma_heap_get_data(heap);
> >>>> +       struct heap_helper_buffer *helper_buffer;
> >>>> +       struct page *pages;
> >>>> +       size_t size = PAGE_ALIGN(len);
> >>>> +       unsigned long nr_pages = size >> PAGE_SHIFT;
> >>>> +       unsigned long align = get_order(size);
> >>>> +       DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
> >>>> +       struct dma_buf *dmabuf;
> >>>> +       int ret = -ENOMEM;
> >>>> +       pgoff_t pg;
> >>>> +
> >>>> +       if (align > CONFIG_CMA_ALIGNMENT)
> >>>> +               align = CONFIG_CMA_ALIGNMENT;
> >>>> +
> >>>> +       helper_buffer = kzalloc(sizeof(*helper_buffer), GFP_KERNEL);
> >>>> +       if (!helper_buffer)
> >>>> +               return -ENOMEM;
> >>>> +
> >>>> +       INIT_HEAP_HELPER_BUFFER(helper_buffer, cma_heap_free);
> >>>> +       helper_buffer->heap_buffer.flags = flags;
> >>>> +       helper_buffer->heap_buffer.heap = heap;
> >>>> +       helper_buffer->heap_buffer.size = len;
> >>>> +
> >>>> +       pages = cma_alloc(cma_heap->cma, nr_pages, align, false);
> >>>> +       if (!pages)
> >>>> +               goto free_buf;
> >>>> +
> >>>> +       if (PageHighMem(pages)) {
> >>>> +               unsigned long nr_clear_pages = nr_pages;
> >>>> +               struct page *page = pages;
> >>>> +
> >>>> +               while (nr_clear_pages > 0) {
> >>>> +                       void *vaddr = kmap_atomic(page);
> >>>> +
> >>>> +                       memset(vaddr, 0, PAGE_SIZE);
> >>>> +                       kunmap_atomic(vaddr);
> >>>> +                       page++;
> >>>> +                       nr_clear_pages--;
> >>>> +               }
> >>>> +       } else {
> >>>> +               memset(page_address(pages), 0, size);
> >>>> +       }
> >>>> +
> >>>> +       helper_buffer->pagecount = nr_pages;
> >>>> +       helper_buffer->pages = kmalloc_array(helper_buffer->pagecount,
> >>>> +                                            sizeof(*helper_buffer->pages),
> >>>> +                                            GFP_KERNEL);
> >>>> +       if (!helper_buffer->pages) {
> >>>> +               ret = -ENOMEM;
> >>>> +               goto free_cma;
> >>>> +       }
> >>>> +
> >>>> +       for (pg = 0; pg < helper_buffer->pagecount; pg++) {
> >>>> +               helper_buffer->pages[pg] = &pages[pg];
> >>>> +               if (!helper_buffer->pages[pg])
> >>>> +                       goto free_pages;
> >>>> +       }
> >>>> +
> >>>> +       /* create the dmabuf */
> >>>> +       exp_info.ops = &heap_helper_ops;
> >>>> +       exp_info.size = len;
> >>>> +       exp_info.flags = O_RDWR;
> >>>
> >>> I think that the flags should be provided when requesting the allocation
> >>> like it is done in DRM or V4L2.
> >>> For me DMA_HEAP_VALID_FLAGS = (O_CLOEXEC | O_ACCMODE).
> >>>
> >>
> >>
> >> So something like done in udmabuf?
> >>
> >> https://elixir.bootlin.com/linux/v5.1-rc1/source/include/uapi/linux/udmabuf.h#L8
> >>
> >> I think that can be arranged.
> >
> > I have in mind what is done by DRM:
> > https://elixir.bootlin.com/linux/v5.1-rc1/source/include/uapi/drm/drm.h#L707
> >
> > V4L2 does the same but without redefine the flags (which is better)
> >
>
> That would mean we would need a whole flag word passed in just for file
> flags when I only ever see one bit being useful(O_CLOEXEC or not). Do
> you see any situation where we need more than default O_RDWR and
> optional O_CLOEXEC for a dma-buf file?

Yes I really want a whole flag word because distinguish RD/WR only cases
could be useful to optimize cache maintenance (and later for secure heaps).

An other argument is that, few years ago, DRM doesn't allow at all O_RDWR
flag, but we manage to change this and make it possible.
So you believe that O_RDWR is mandatory will others O_RDWR is useless,
put it into a flag will make everybody happy :-)

Benjamin
>
> Andrew
>
> > Benjamin
> >
> >>
> >> John,
> >>
> >> This might be a good reason to move the dma_buf_fd() call below out of
> >> the heap and back into the core. That way the file exporting flags can
> >> be common and core handled. I don't think it would complicate the error
> >> handling any as we only need to dma_buf_put(dmabuf) in the core on
> >> failure and the heap specific cleanup will happen for us.
> >>
> >> Andrew
> >>
> >>
> >>> Benjamin
> >>>
> >>> Benjamin
> >>>
> >>>> +       exp_info.priv = &helper_buffer->heap_buffer;
> >>>> +       dmabuf = dma_buf_export(&exp_info);
> >>>> +       if (IS_ERR(dmabuf)) {
> >>>> +               ret = PTR_ERR(dmabuf);
> >>>> +               goto free_pages;
> >>>> +       }
> >>>> +
> >>>> +       helper_buffer->heap_buffer.dmabuf = dmabuf;
> >>>> +       helper_buffer->priv_virt = pages;
> >>>> +
> >>>> +       ret = dma_buf_fd(dmabuf, O_CLOEXEC);
> >>>> +       if (ret < 0) {
> >>>> +               dma_buf_put(dmabuf);
> >>>> +               /* just return, as put will call release and that will free */
> >>>> +               return ret;
> >>>> +       }
> >>>> +
> >>>> +       return ret;
> >>>> +
> >>>> +free_pages:
> >>>> +       kfree(helper_buffer->pages);
> >>>> +free_cma:
> >>>> +       cma_release(cma_heap->cma, pages, nr_pages);
> >>>> +free_buf:
> >>>> +       kfree(helper_buffer);
> >>>> +       return ret;
> >>>> +}
> >>>> +
> >>>> +static struct dma_heap_ops cma_heap_ops = {
> >>>> +       .allocate = cma_heap_allocate,
> >>>> +};
> >>>> +
> >>>> +static int __add_cma_heap(struct cma *cma, void *data)
> >>>> +{
> >>>> +       struct cma_heap *cma_heap;
> >>>> +       struct dma_heap_export_info exp_info;
> >>>> +
> >>>> +       cma_heap = kzalloc(sizeof(*cma_heap), GFP_KERNEL);
> >>>> +       if (!cma_heap)
> >>>> +               return -ENOMEM;
> >>>> +       cma_heap->cma = cma;
> >>>> +
> >>>> +       exp_info.name = cma_get_name(cma);
> >>>> +       exp_info.ops = &cma_heap_ops;
> >>>> +       exp_info.priv = cma_heap;
> >>>> +
> >>>> +       cma_heap->heap = dma_heap_add(&exp_info);
> >>>> +       if (IS_ERR(cma_heap->heap)) {
> >>>> +               int ret = PTR_ERR(cma_heap->heap);
> >>>> +
> >>>> +               kfree(cma_heap);
> >>>> +               return ret;
> >>>> +       }
> >>>> +
> >>>> +       return 0;
> >>>> +}
> >>>> +
> >>>> +static int add_cma_heaps(void)
> >>>> +{
> >>>> +       cma_for_each_area(__add_cma_heap, NULL);
> >>>> +       return 0;
> >>>> +}
> >>>> +device_initcall(add_cma_heaps);
> >>>> --
> >>>> 2.7.4
> >>>>

Re: [RFC][PATCH 4/6 v3] dma-buf: heaps: Add CMA heap to dmabuf heapss

[Benjamin Gaignard]

Le ven. 29 mars 2019 à 16:42, Andrew F. Davis <afd@ti.com> a écrit :
>
> On 3/29/19 10:30 AM, Benjamin Gaignard wrote:
> > Le ven. 29 mars 2019 à 16:19, Andrew F. Davis <afd@ti.com> a écrit :
> >>
> >> On 3/29/19 9:44 AM, Benjamin Gaignard wrote:
> >>> Le ven. 29 mars 2019 à 01:16, John Stultz <john.stultz@linaro.org> a écrit :
> >>>>
> >>>> This adds a CMA heap, which allows userspace to allocate
> >>>> a dma-buf of contiguous memory out of a CMA region.
> >>>>
> >>>> This code is an evolution of the Android ION implementation, so
> >>>> thanks to its original author and maintainters:
> >>>>   Benjamin Gaignard, Laura Abbott, and others!
> >>>>
> >>>> Cc: Laura Abbott <labbott@redhat.com>
> >>>> Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
> >>>> Cc: Sumit Semwal <sumit.semwal@linaro.org>
> >>>> Cc: Liam Mark <lmark@codeaurora.org>
> >>>> Cc: Pratik Patel <pratikp@codeaurora.org>
> >>>> Cc: Brian Starkey <Brian.Starkey@arm.com>
> >>>> Cc: Vincent Donnefort <Vincent.Donnefort@arm.com>
> >>>> Cc: Sudipto Paul <Sudipto.Paul@arm.com>
> >>>> Cc: Andrew F. Davis <afd@ti.com>
> >>>> Cc: Xu YiPing <xuyiping@hisilicon.com>
> >>>> Cc: "Chenfeng (puck)" <puck.chen@hisilicon.com>
> >>>> Cc: butao <butao@hisilicon.com>
> >>>> Cc: "Xiaqing (A)" <saberlily.xia@hisilicon.com>
> >>>> Cc: Yudongbin <yudongbin@hisilicon.com>
> >>>> Cc: Christoph Hellwig <hch@infradead.org>
> >>>> Cc: Chenbo Feng <fengc@google.com>
> >>>> Cc: Alistair Strachan <astrachan@google.com>
> >>>> Cc: dri-devel@lists.freedesktop.org
> >>>> Signed-off-by: John Stultz <john.stultz@linaro.org>
> >>>> ---
> >>>> v2:
> >>>> * Switch allocate to return dmabuf fd
> >>>> * Simplify init code
> >>>> * Checkpatch fixups
> >>>> v3:
> >>>> * Switch to inline function for to_cma_heap()
> >>>> * Minor cleanups suggested by Brian
> >>>> * Fold in new registration style from Andrew
> >>>> * Folded in changes from Andrew to use simplified page list
> >>>>   from the heap helpers
> >>>> ---
> >>>>  drivers/dma-buf/heaps/Kconfig    |   8 ++
> >>>>  drivers/dma-buf/heaps/Makefile   |   1 +
> >>>>  drivers/dma-buf/heaps/cma_heap.c | 170 +++++++++++++++++++++++++++++++++++++++
> >>>>  3 files changed, 179 insertions(+)
> >>>>  create mode 100644 drivers/dma-buf/heaps/cma_heap.c
> >>>>
> >>>> diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig
> >>>> index 2050527..a5eef06 100644
> >>>> --- a/drivers/dma-buf/heaps/Kconfig
> >>>> +++ b/drivers/dma-buf/heaps/Kconfig
> >>>> @@ -4,3 +4,11 @@ config DMABUF_HEAPS_SYSTEM
> >>>>         help
> >>>>           Choose this option to enable the system dmabuf heap. The system heap
> >>>>           is backed by pages from the buddy allocator. If in doubt, say Y.
> >>>> +
> >>>> +config DMABUF_HEAPS_CMA
> >>>> +       bool "DMA-BUF CMA Heap"
> >>>> +       depends on DMABUF_HEAPS && DMA_CMA
> >>>> +       help
> >>>> +         Choose this option to enable dma-buf CMA heap. This heap is backed
> >>>> +         by the Contiguous Memory Allocator (CMA). If your system has these
> >>>> +         regions, you should say Y here.
> >>>> diff --git a/drivers/dma-buf/heaps/Makefile b/drivers/dma-buf/heaps/Makefile
> >>>> index d1808ec..6e54cde 100644
> >>>> --- a/drivers/dma-buf/heaps/Makefile
> >>>> +++ b/drivers/dma-buf/heaps/Makefile
> >>>> @@ -1,3 +1,4 @@
> >>>>  # SPDX-License-Identifier: GPL-2.0
> >>>>  obj-y                                  += heap-helpers.o
> >>>>  obj-$(CONFIG_DMABUF_HEAPS_SYSTEM)      += system_heap.o
> >>>> +obj-$(CONFIG_DMABUF_HEAPS_CMA)         += cma_heap.o
> >>>> diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c
> >>>> new file mode 100644
> >>>> index 0000000..f4485c60
> >>>> --- /dev/null
> >>>> +++ b/drivers/dma-buf/heaps/cma_heap.c
> >>>> @@ -0,0 +1,170 @@
> >>>> +// SPDX-License-Identifier: GPL-2.0
> >>>> +/*
> >>>> + * DMABUF CMA heap exporter
> >>>> + *
> >>>> + * Copyright (C) 2012, 2019 Linaro Ltd.
> >>>> + * Author: <benjamin.gaignard@linaro.org> for ST-Ericsson.
> >>>> + */
> >>>> +
> >>>> +#include <linux/device.h>
> >>>> +#include <linux/dma-buf.h>
> >>>> +#include <linux/dma-heap.h>
> >>>> +#include <linux/slab.h>
> >>>> +#include <linux/errno.h>
> >>>> +#include <linux/err.h>
> >>>> +#include <linux/cma.h>
> >>>> +#include <linux/scatterlist.h>
> >>>> +#include <linux/highmem.h>
> >>>> +
> >>>> +#include "heap-helpers.h"
> >>>> +
> >>>> +struct cma_heap {
> >>>> +       struct dma_heap *heap;
> >>>> +       struct cma *cma;
> >>>> +};
> >>>> +
> >>>> +static void cma_heap_free(struct heap_helper_buffer *buffer)
> >>>> +{
> >>>> +       struct cma_heap *cma_heap = dma_heap_get_data(buffer->heap_buffer.heap);
> >>>> +       struct page *pages = buffer->priv_virt;
> >>>> +       unsigned long nr_pages;
> >>>> +
> >>>> +       nr_pages = buffer->heap_buffer.size >> PAGE_SHIFT;
> >>>> +
> >>>> +       /* free page list */
> >>>> +       kfree(buffer->pages);
> >>>> +       /* release memory */
> >>>> +       cma_release(cma_heap->cma, pages, nr_pages);
> >>>> +       kfree(buffer);
> >>>> +}
> >>>> +
> >>>> +/* dmabuf heap CMA operations functions */
> >>>> +static int cma_heap_allocate(struct dma_heap *heap,
> >>>> +                               unsigned long len,
> >>>> +                               unsigned long flags)
> >>>> +{
> >>>> +       struct cma_heap *cma_heap = dma_heap_get_data(heap);
> >>>> +       struct heap_helper_buffer *helper_buffer;
> >>>> +       struct page *pages;
> >>>> +       size_t size = PAGE_ALIGN(len);
> >>>> +       unsigned long nr_pages = size >> PAGE_SHIFT;
> >>>> +       unsigned long align = get_order(size);
> >>>> +       DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
> >>>> +       struct dma_buf *dmabuf;
> >>>> +       int ret = -ENOMEM;
> >>>> +       pgoff_t pg;
> >>>> +
> >>>> +       if (align > CONFIG_CMA_ALIGNMENT)
> >>>> +               align = CONFIG_CMA_ALIGNMENT;
> >>>> +
> >>>> +       helper_buffer = kzalloc(sizeof(*helper_buffer), GFP_KERNEL);
> >>>> +       if (!helper_buffer)
> >>>> +               return -ENOMEM;
> >>>> +
> >>>> +       INIT_HEAP_HELPER_BUFFER(helper_buffer, cma_heap_free);
> >>>> +       helper_buffer->heap_buffer.flags = flags;
> >>>> +       helper_buffer->heap_buffer.heap = heap;
> >>>> +       helper_buffer->heap_buffer.size = len;
> >>>> +
> >>>> +       pages = cma_alloc(cma_heap->cma, nr_pages, align, false);
> >>>> +       if (!pages)
> >>>> +               goto free_buf;
> >>>> +
> >>>> +       if (PageHighMem(pages)) {
> >>>> +               unsigned long nr_clear_pages = nr_pages;
> >>>> +               struct page *page = pages;
> >>>> +
> >>>> +               while (nr_clear_pages > 0) {
> >>>> +                       void *vaddr = kmap_atomic(page);
> >>>> +
> >>>> +                       memset(vaddr, 0, PAGE_SIZE);
> >>>> +                       kunmap_atomic(vaddr);
> >>>> +                       page++;
> >>>> +                       nr_clear_pages--;
> >>>> +               }
> >>>> +       } else {
> >>>> +               memset(page_address(pages), 0, size);
> >>>> +       }
> >>>> +
> >>>> +       helper_buffer->pagecount = nr_pages;
> >>>> +       helper_buffer->pages = kmalloc_array(helper_buffer->pagecount,
> >>>> +                                            sizeof(*helper_buffer->pages),
> >>>> +                                            GFP_KERNEL);
> >>>> +       if (!helper_buffer->pages) {
> >>>> +               ret = -ENOMEM;
> >>>> +               goto free_cma;
> >>>> +       }
> >>>> +
> >>>> +       for (pg = 0; pg < helper_buffer->pagecount; pg++) {
> >>>> +               helper_buffer->pages[pg] = &pages[pg];
> >>>> +               if (!helper_buffer->pages[pg])
> >>>> +                       goto free_pages;
> >>>> +       }
> >>>> +
> >>>> +       /* create the dmabuf */
> >>>> +       exp_info.ops = &heap_helper_ops;
> >>>> +       exp_info.size = len;
> >>>> +       exp_info.flags = O_RDWR;
> >>>
> >>> I think that the flags should be provided when requesting the allocation
> >>> like it is done in DRM or V4L2.
> >>> For me DMA_HEAP_VALID_FLAGS = (O_CLOEXEC | O_ACCMODE).
> >>>
> >>
> >>
> >> So something like done in udmabuf?
> >>
> >> https://elixir.bootlin.com/linux/v5.1-rc1/source/include/uapi/linux/udmabuf.h#L8
> >>
> >> I think that can be arranged.
> >
> > I have in mind what is done by DRM:
> > https://elixir.bootlin.com/linux/v5.1-rc1/source/include/uapi/drm/drm.h#L707
> >
> > V4L2 does the same but without redefine the flags (which is better)
> >
>
> That would mean we would need a whole flag word passed in just for file
> flags when I only ever see one bit being useful(O_CLOEXEC or not). Do
> you see any situation where we need more than default O_RDWR and
> optional O_CLOEXEC for a dma-buf file?

Yes I really want a whole flag word because distinguish RD/WR only cases
could be useful to optimize cache maintenance (and later for secure heaps).

An other argument is that, few years ago, DRM doesn't allow at all O_RDWR
flag, but we manage to change this and make it possible.
So you believe that O_RDWR is mandatory will others O_RDWR is useless,
put it into a flag will make everybody happy :-)

Benjamin
>
> Andrew
>
> > Benjamin
> >
> >>
> >> John,
> >>
> >> This might be a good reason to move the dma_buf_fd() call below out of
> >> the heap and back into the core. That way the file exporting flags can
> >> be common and core handled. I don't think it would complicate the error
> >> handling any as we only need to dma_buf_put(dmabuf) in the core on
> >> failure and the heap specific cleanup will happen for us.
> >>
> >> Andrew
> >>
> >>
> >>> Benjamin
> >>>
> >>> Benjamin
> >>>
> >>>> +       exp_info.priv = &helper_buffer->heap_buffer;
> >>>> +       dmabuf = dma_buf_export(&exp_info);
> >>>> +       if (IS_ERR(dmabuf)) {
> >>>> +               ret = PTR_ERR(dmabuf);
> >>>> +               goto free_pages;
> >>>> +       }
> >>>> +
> >>>> +       helper_buffer->heap_buffer.dmabuf = dmabuf;
> >>>> +       helper_buffer->priv_virt = pages;
> >>>> +
> >>>> +       ret = dma_buf_fd(dmabuf, O_CLOEXEC);
> >>>> +       if (ret < 0) {
> >>>> +               dma_buf_put(dmabuf);
> >>>> +               /* just return, as put will call release and that will free */
> >>>> +               return ret;
> >>>> +       }
> >>>> +
> >>>> +       return ret;
> >>>> +
> >>>> +free_pages:
> >>>> +       kfree(helper_buffer->pages);
> >>>> +free_cma:
> >>>> +       cma_release(cma_heap->cma, pages, nr_pages);
> >>>> +free_buf:
> >>>> +       kfree(helper_buffer);
> >>>> +       return ret;
> >>>> +}
> >>>> +
> >>>> +static struct dma_heap_ops cma_heap_ops = {
> >>>> +       .allocate = cma_heap_allocate,
> >>>> +};
> >>>> +
> >>>> +static int __add_cma_heap(struct cma *cma, void *data)
> >>>> +{
> >>>> +       struct cma_heap *cma_heap;
> >>>> +       struct dma_heap_export_info exp_info;
> >>>> +
> >>>> +       cma_heap = kzalloc(sizeof(*cma_heap), GFP_KERNEL);
> >>>> +       if (!cma_heap)
> >>>> +               return -ENOMEM;
> >>>> +       cma_heap->cma = cma;
> >>>> +
> >>>> +       exp_info.name = cma_get_name(cma);
> >>>> +       exp_info.ops = &cma_heap_ops;
> >>>> +       exp_info.priv = cma_heap;
> >>>> +
> >>>> +       cma_heap->heap = dma_heap_add(&exp_info);
> >>>> +       if (IS_ERR(cma_heap->heap)) {
> >>>> +               int ret = PTR_ERR(cma_heap->heap);
> >>>> +
> >>>> +               kfree(cma_heap);
> >>>> +               return ret;
> >>>> +       }
> >>>> +
> >>>> +       return 0;
> >>>> +}
> >>>> +
> >>>> +static int add_cma_heaps(void)
> >>>> +{
> >>>> +       cma_for_each_area(__add_cma_heap, NULL);
> >>>> +       return 0;
> >>>> +}
> >>>> +device_initcall(add_cma_heaps);
> >>>> --
> >>>> 2.7.4
> >>>>
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel