[PATCH v6 00/36] DRM: fix struct sg_table nents vs. orig_nents misuse

[PATCH v6 00/36] DRM: fix struct sg_table nents vs. orig_nents misuse

[Marek Szyprowski]

Dear All,

During the Exynos DRM GEM rework and fixing the issues in the.
drm_prime_sg_to_page_addr_arrays() function [1] I've noticed that most
drivers in DRM framework incorrectly use nents and orig_nents entries of
the struct sg_table.

In case of the most DMA-mapping implementations exchanging those two
entries or using nents for all loops on the scatterlist is harmless,
because they both have the same value. There exists however a DMA-mapping
implementations, for which such incorrect usage breaks things. The nents
returned by dma_map_sg() might be lower than the nents passed as its
parameter and this is perfectly fine. DMA framework or IOMMU is allowed
to join consecutive chunks while mapping if such operation is supported
by the underlying HW (bus, bridge, IOMMU, etc). Example of the case
where dma_map_sg() might return 1 'DMA' chunk for the 4 'physical' pages
is described here [2]

The DMA-mapping framework documentation [3] states that dma_map_sg()
returns the numer of the created entries in the DMA address space.
However the subsequent calls to dma_sync_sg_for_{device,cpu} and
dma_unmap_sg must be called with the original number of entries passed to
dma_map_sg. The common pattern in DRM drivers were to assign the
dma_map_sg() return value to sg_table->nents and use that value for
the subsequent calls to dma_sync_sg_* or dma_unmap_sg functions. Also
the code iterated over nents times to access the pages stored in the
processed scatterlist, while it should use orig_nents as the numer of
the page entries.

I've tried to identify all such incorrect usage of sg_table->nents and
this is a result of my research. It looks that the incorrect pattern has
been copied over the many drivers mainly in the DRM subsystem. Too bad in
most cases it even worked correctly if the system used a simple, linear
DMA-mapping implementation, for which swapping nents and orig_nents
doesn't make any difference. To avoid similar issues in the future, I've
introduced a common wrappers for DMA-mapping calls, which operate directly
on the sg_table objects. I've also added wrappers for iterating over the
scatterlists stored in the sg_table objects and applied them where
possible. This, together with some common DRM prime helpers, allowed me
to almost get rid of all nents/orig_nents usage in the drivers. I hope
that such change makes the code robust, easier to follow and copy/paste
safe.

The biggest TODO is DRM/i915 driver and I don't feel brave enough to fix
it fully. The driver creatively uses sg_table->orig_nents to store the
size of the allocate scatterlist and ignores the number of the entries
returned by dma_map_sg function. In this patchset I only fixed the
sg_table objects exported by dmabuf related functions. I hope that I
didn't break anything there.

Patches are based on top of Linux next-20200618. The required changes to
DMA-mapping framework has been already merged to v5.8-rc1.

If possible I would like ask for merging most of the patches via DRM
tree.

Best regards,
Marek Szyprowski


References:

[1] https://lkml.org/lkml/2020/3/27/555
[2] https://lkml.org/lkml/2020/3/29/65
[3] Documentation/DMA-API-HOWTO.txt
[4] https://lore.kernel.org/linux-iommu/20200512121931.GD20393@lst.de/T/#ma18c958a48c3b241d5409517fa7d192eef87459b

Changelog:

v6:
- rebased onto Linux next-20200618, which is based on v5.8-rc1; fixed conflicts

v5: https://lore.kernel.org/linux-iommu/20200513132114.6046-1-m.szyprowski@samsung.com/T/
- fixed some minor style issues and typos
- fixed lack of the attrs argument in ion, dmabuf, rapidio, fastrpc and
  vfio patches

v4: https://lore.kernel.org/linux-iommu/20200512121931.GD20393@lst.de/T/
- added for_each_sgtable_* wrappers and applied where possible
- added drm_prime_get_contiguous_size() and applied where possible
- applied drm_prime_sg_to_page_addr_arrays() where possible to remove page
  extraction from sg_table objects
- added documentation for the introduced wrappers
- improved patches description a bit

v3: https://lore.kernel.org/dri-devel/20200505083926.28503-1-m.szyprowski@samsung.com/
- introduce dma_*_sgtable_* wrappers and use them in all patches

v2: https://lore.kernel.org/linux-iommu/c01c9766-9778-fd1f-f36e-2dc7bd376ba4@arm.com/T/
- dropped most of the changes to drm/i915
- added fixes for rcar-du, xen, media and ion
- fixed a few issues pointed by kbuild test robot
- added wide cc: list for each patch

v1: https://lore.kernel.org/linux-iommu/c01c9766-9778-fd1f-f36e-2dc7bd376ba4@arm.com/T/
- initial version


Patch summary:

Marek Szyprowski (36):
  drm: prime: add common helper to check scatterlist contiguity
  drm: prime: use sgtable iterators in
    drm_prime_sg_to_page_addr_arrays()
  drm: core: fix common struct sg_table related issues
  drm: amdgpu: fix common struct sg_table related issues
  drm: armada: fix common struct sg_table related issues
  drm: etnaviv: fix common struct sg_table related issues
  drm: exynos: use common helper for a scatterlist contiguity check
  drm: exynos: fix common struct sg_table related issues
  drm: i915: fix common struct sg_table related issues
  drm: lima: fix common struct sg_table related issues
  drm: mediatek: use common helper for a scatterlist contiguity check
  drm: mediatek: use common helper for extracting pages array
  drm: msm: fix common struct sg_table related issues
  drm: omapdrm: use common helper for extracting pages array
  drm: omapdrm: fix common struct sg_table related issues
  drm: panfrost: fix common struct sg_table related issues
  drm: radeon: fix common struct sg_table related issues
  drm: rockchip: use common helper for a scatterlist contiguity check
  drm: rockchip: fix common struct sg_table related issues
  drm: tegra: fix common struct sg_table related issues
  drm: v3d: fix common struct sg_table related issues
  drm: virtio: fix common struct sg_table related issues
  drm: vmwgfx: fix common struct sg_table related issues
  xen: gntdev: fix common struct sg_table related issues
  drm: host1x: fix common struct sg_table related issues
  drm: rcar-du: fix common struct sg_table related issues
  dmabuf: fix common struct sg_table related issues
  staging: ion: remove dead code
  staging: ion: fix common struct sg_table related issues
  staging: tegra-vde: fix common struct sg_table related issues
  misc: fastrpc: fix common struct sg_table related issues
  rapidio: fix common struct sg_table related issues
  samples: vfio-mdev/mbochs: fix common struct sg_table related issues
  media: pci: fix common ALSA DMA-mapping related codes
  videobuf2: use sgtable-based scatterlist wrappers
  drm: xen: fix common struct sg_table related issues

 drivers/dma-buf/heaps/heap-helpers.c          | 13 ++-
 drivers/dma-buf/udmabuf.c                     |  7 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c   |  6 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c       |  9 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c  |  8 +-
 drivers/gpu/drm/armada/armada_gem.c           | 12 +--
 drivers/gpu/drm/drm_cache.c                   |  2 +-
 drivers/gpu/drm/drm_gem_cma_helper.c          | 23 +----
 drivers/gpu/drm/drm_gem_shmem_helper.c        | 14 +--
 drivers/gpu/drm/drm_prime.c                   | 86 ++++++++++---------
 drivers/gpu/drm/etnaviv/etnaviv_gem.c         | 12 ++-
 drivers/gpu/drm/etnaviv/etnaviv_mmu.c         | 13 +--
 drivers/gpu/drm/exynos/exynos_drm_g2d.c       | 10 +--
 drivers/gpu/drm/exynos/exynos_drm_gem.c       | 23 +----
 drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c    | 11 +--
 .../gpu/drm/i915/gem/selftests/mock_dmabuf.c  |  7 +-
 drivers/gpu/drm/lima/lima_gem.c               | 11 ++-
 drivers/gpu/drm/lima/lima_vm.c                |  5 +-
 drivers/gpu/drm/mediatek/mtk_drm_gem.c        | 37 ++------
 drivers/gpu/drm/msm/msm_gem.c                 | 13 ++-
 drivers/gpu/drm/msm/msm_gpummu.c              | 14 ++-
 drivers/gpu/drm/msm/msm_iommu.c               |  2 +-
 drivers/gpu/drm/omapdrm/omap_gem.c            | 20 ++---
 drivers/gpu/drm/panfrost/panfrost_gem.c       |  4 +-
 drivers/gpu/drm/panfrost/panfrost_mmu.c       |  7 +-
 drivers/gpu/drm/radeon/radeon_ttm.c           | 11 ++-
 drivers/gpu/drm/rcar-du/rcar_du_vsp.c         |  3 +-
 drivers/gpu/drm/rockchip/rockchip_drm_gem.c   | 42 +++------
 drivers/gpu/drm/tegra/gem.c                   | 27 +++---
 drivers/gpu/drm/tegra/plane.c                 | 15 ++--
 drivers/gpu/drm/v3d/v3d_mmu.c                 | 17 ++--
 drivers/gpu/drm/virtio/virtgpu_object.c       | 36 ++++----
 drivers/gpu/drm/virtio/virtgpu_vq.c           | 12 ++-
 drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c    | 17 +---
 drivers/gpu/drm/xen/xen_drm_front_gem.c       |  2 +-
 drivers/gpu/host1x/job.c                      | 22 ++---
 .../common/videobuf2/videobuf2-dma-contig.c   | 41 ++++-----
 .../media/common/videobuf2/videobuf2-dma-sg.c | 32 +++----
 .../common/videobuf2/videobuf2-vmalloc.c      | 12 +--
 drivers/media/pci/cx23885/cx23885-alsa.c      |  2 +-
 drivers/media/pci/cx25821/cx25821-alsa.c      |  2 +-
 drivers/media/pci/cx88/cx88-alsa.c            |  2 +-
 drivers/media/pci/saa7134/saa7134-alsa.c      |  2 +-
 drivers/media/platform/vsp1/vsp1_drm.c        |  8 +-
 drivers/misc/fastrpc.c                        |  4 +-
 drivers/rapidio/devices/rio_mport_cdev.c      |  8 +-
 drivers/staging/android/ion/ion.c             | 25 +++---
 drivers/staging/android/ion/ion.h             |  1 -
 drivers/staging/android/ion/ion_heap.c        | 53 +++---------
 drivers/staging/android/ion/ion_system_heap.c |  2 +-
 drivers/staging/media/tegra-vde/iommu.c       |  4 +-
 drivers/xen/gntdev-dmabuf.c                   | 13 ++-
 include/drm/drm_prime.h                       |  2 +
 samples/vfio-mdev/mbochs.c                    |  3 +-
 54 files changed, 311 insertions(+), 478 deletions(-)

-- 
2.17.1

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[PATCH v6 01/36] drm: prime: add common helper to check scatterlist contiguity

[Marek Szyprowski]

It is a common operation done by DRM drivers to check the contiguity
of the DMA-mapped buffer described by a scatterlist in the
sg_table object. Let's add a common helper for this operation.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/gpu/drm/drm_gem_cma_helper.c | 23 +++--------------------
 drivers/gpu/drm/drm_prime.c          | 26 ++++++++++++++++++++++++++
 include/drm/drm_prime.h              |  2 ++
 3 files changed, 31 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c b/drivers/gpu/drm/drm_gem_cma_helper.c
index 06a5b9ee1fe0..41566a15dabd 100644
--- a/drivers/gpu/drm/drm_gem_cma_helper.c
+++ b/drivers/gpu/drm/drm_gem_cma_helper.c
@@ -471,26 +471,9 @@ drm_gem_cma_prime_import_sg_table(struct drm_device *dev,
 {
 	struct drm_gem_cma_object *cma_obj;
 
-	if (sgt->nents != 1) {
-		/* check if the entries in the sg_table are contiguous */
-		dma_addr_t next_addr = sg_dma_address(sgt->sgl);
-		struct scatterlist *s;
-		unsigned int i;
-
-		for_each_sg(sgt->sgl, s, sgt->nents, i) {
-			/*
-			 * sg_dma_address(s) is only valid for entries
-			 * that have sg_dma_len(s) != 0
-			 */
-			if (!sg_dma_len(s))
-				continue;
-
-			if (sg_dma_address(s) != next_addr)
-				return ERR_PTR(-EINVAL);
-
-			next_addr = sg_dma_address(s) + sg_dma_len(s);
-		}
-	}
+	/* check if the entries in the sg_table are contiguous */
+	if (drm_prime_get_contiguous_size(sgt) < attach->dmabuf->size)
+		return ERR_PTR(-EINVAL);
 
 	/* Create a CMA GEM buffer. */
 	cma_obj = __drm_gem_cma_create(dev, attach->dmabuf->size);
diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index bbfc713bfdc3..0784969894c1 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -825,6 +825,32 @@ struct sg_table *drm_prime_pages_to_sg(struct page **pages, unsigned int nr_page
 }
 EXPORT_SYMBOL(drm_prime_pages_to_sg);
 
+/**
+ * drm_prime_get_contiguous_size - returns the contiguous size of the buffer
+ * @sgt: sg_table describing the buffer to check
+ *
+ * This helper calculates the contiguous size in the DMA address space
+ * of the the buffer described by the provided sg_table.
+ *
+ * This is useful for implementing
+ * &drm_gem_object_funcs.gem_prime_import_sg_table.
+ */
+unsigned long drm_prime_get_contiguous_size(struct sg_table *sgt)
+{
+	dma_addr_t expected = sg_dma_address(sgt->sgl);
+	struct sg_dma_page_iter dma_iter;
+	unsigned long size = 0;
+
+	for_each_sgtable_dma_page(sgt, &dma_iter, 0) {
+		if (sg_page_iter_dma_address(&dma_iter) != expected)
+			break;
+		expected += PAGE_SIZE;
+		size += PAGE_SIZE;
+	}
+	return size;
+}
+EXPORT_SYMBOL(drm_prime_get_contiguous_size);
+
 /**
  * drm_gem_prime_export - helper library implementation of the export callback
  * @obj: GEM object to export
diff --git a/include/drm/drm_prime.h b/include/drm/drm_prime.h
index 9af7422b44cf..47ef11614627 100644
--- a/include/drm/drm_prime.h
+++ b/include/drm/drm_prime.h
@@ -92,6 +92,8 @@ struct sg_table *drm_prime_pages_to_sg(struct page **pages, unsigned int nr_page
 struct dma_buf *drm_gem_prime_export(struct drm_gem_object *obj,
 				     int flags);
 
+unsigned long drm_prime_get_contiguous_size(struct sg_table *sgt);
+
 /* helper functions for importing */
 struct drm_gem_object *drm_gem_prime_import_dev(struct drm_device *dev,
 						struct dma_buf *dma_buf,
-- 
2.17.1

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Re: [PATCH v6 01/36] drm: prime: add common helper to check scatterlist contiguity

[Robin Murphy]

On 2020-06-18 16:39, Marek Szyprowski wrote:
> It is a common operation done by DRM drivers to check the contiguity
> of the DMA-mapped buffer described by a scatterlist in the
> sg_table object. Let's add a common helper for this operation.
> 
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> ---
>   drivers/gpu/drm/drm_gem_cma_helper.c | 23 +++--------------------
>   drivers/gpu/drm/drm_prime.c          | 26 ++++++++++++++++++++++++++
>   include/drm/drm_prime.h              |  2 ++
>   3 files changed, 31 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c b/drivers/gpu/drm/drm_gem_cma_helper.c
> index 06a5b9ee1fe0..41566a15dabd 100644
> --- a/drivers/gpu/drm/drm_gem_cma_helper.c
> +++ b/drivers/gpu/drm/drm_gem_cma_helper.c
> @@ -471,26 +471,9 @@ drm_gem_cma_prime_import_sg_table(struct drm_device *dev,
>   {
>   	struct drm_gem_cma_object *cma_obj;
>   
> -	if (sgt->nents != 1) {
> -		/* check if the entries in the sg_table are contiguous */
> -		dma_addr_t next_addr = sg_dma_address(sgt->sgl);
> -		struct scatterlist *s;
> -		unsigned int i;
> -
> -		for_each_sg(sgt->sgl, s, sgt->nents, i) {
> -			/*
> -			 * sg_dma_address(s) is only valid for entries
> -			 * that have sg_dma_len(s) != 0
> -			 */
> -			if (!sg_dma_len(s))
> -				continue;
> -
> -			if (sg_dma_address(s) != next_addr)
> -				return ERR_PTR(-EINVAL);
> -
> -			next_addr = sg_dma_address(s) + sg_dma_len(s);
> -		}
> -	}
> +	/* check if the entries in the sg_table are contiguous */
> +	if (drm_prime_get_contiguous_size(sgt) < attach->dmabuf->size)
> +		return ERR_PTR(-EINVAL);
>   
>   	/* Create a CMA GEM buffer. */
>   	cma_obj = __drm_gem_cma_create(dev, attach->dmabuf->size);
> diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
> index bbfc713bfdc3..0784969894c1 100644
> --- a/drivers/gpu/drm/drm_prime.c
> +++ b/drivers/gpu/drm/drm_prime.c
> @@ -825,6 +825,32 @@ struct sg_table *drm_prime_pages_to_sg(struct page **pages, unsigned int nr_page
>   }
>   EXPORT_SYMBOL(drm_prime_pages_to_sg);
>   
> +/**
> + * drm_prime_get_contiguous_size - returns the contiguous size of the buffer
> + * @sgt: sg_table describing the buffer to check
> + *
> + * This helper calculates the contiguous size in the DMA address space
> + * of the the buffer described by the provided sg_table.
> + *
> + * This is useful for implementing
> + * &drm_gem_object_funcs.gem_prime_import_sg_table.
> + */
> +unsigned long drm_prime_get_contiguous_size(struct sg_table *sgt)
> +{
> +	dma_addr_t expected = sg_dma_address(sgt->sgl);
> +	struct sg_dma_page_iter dma_iter;
> +	unsigned long size = 0;
> +
> +	for_each_sgtable_dma_page(sgt, &dma_iter, 0) {
> +		if (sg_page_iter_dma_address(&dma_iter) != expected)
> +			break;
> +		expected += PAGE_SIZE;
> +		size += PAGE_SIZE;

Hmm, in many cases this is likely to be far less efficient than simply 
using for_each_sgtable_dma() and sg_dma_len() equivalent to the original 
implementation, and there doesn't seem to be any good reason for that. 
Plus AFAICS it could potentially let false-positives through if someone 
were to pass in a table with non-page-aligned lengths (I assume that's 
expected never to happen, but still...)

Robin.

> +	}
> +	return size;
> +}
> +EXPORT_SYMBOL(drm_prime_get_contiguous_size);
> +
>   /**
>    * drm_gem_prime_export - helper library implementation of the export callback
>    * @obj: GEM object to export
> diff --git a/include/drm/drm_prime.h b/include/drm/drm_prime.h
> index 9af7422b44cf..47ef11614627 100644
> --- a/include/drm/drm_prime.h
> +++ b/include/drm/drm_prime.h
> @@ -92,6 +92,8 @@ struct sg_table *drm_prime_pages_to_sg(struct page **pages, unsigned int nr_page
>   struct dma_buf *drm_gem_prime_export(struct drm_gem_object *obj,
>   				     int flags);
>   
> +unsigned long drm_prime_get_contiguous_size(struct sg_table *sgt);
> +
>   /* helper functions for importing */
>   struct drm_gem_object *drm_gem_prime_import_dev(struct drm_device *dev,
>   						struct dma_buf *dma_buf,
> 
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[PATCH v6 02/36] drm: prime: use sgtable iterators in drm_prime_sg_to_page_addr_arrays()

[Marek Szyprowski]

Replace the current hand-crafted code for extracting pages and DMA
addresses from the given scatterlist by the much more robust
code based on the generic scatterlist iterators and recently
introduced sg_table-based wrappers. The resulting code is simple and
easy to understand, so the comment describing the old code is no
longer needed.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/gpu/drm/drm_prime.c | 47 +++++++++++--------------------------
 1 file changed, 14 insertions(+), 33 deletions(-)

diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 0784969894c1..22953ee1e2ba 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -985,45 +985,26 @@ EXPORT_SYMBOL(drm_gem_prime_import);
 int drm_prime_sg_to_page_addr_arrays(struct sg_table *sgt, struct page **pages,
 				     dma_addr_t *addrs, int max_entries)
 {
-	unsigned count;
-	struct scatterlist *sg;
-	struct page *page;
-	u32 page_len, page_index;
-	dma_addr_t addr;
-	u32 dma_len, dma_index;
+	struct sg_dma_page_iter dma_iter;
+	struct sg_page_iter page_iter;
+	struct page **p = pages;
+	dma_addr_t *a = addrs;
 
-	/*
-	 * Scatterlist elements contains both pages and DMA addresses, but
-	 * one shoud not assume 1:1 relation between them. The sg->length is
-	 * the size of the physical memory chunk described by the sg->page,
-	 * while sg_dma_len(sg) is the size of the DMA (IO virtual) chunk
-	 * described by the sg_dma_address(sg).
-	 */
-	page_index = 0;
-	dma_index = 0;
-	for_each_sg(sgt->sgl, sg, sgt->nents, count) {
-		page_len = sg->length;
-		page = sg_page(sg);
-		dma_len = sg_dma_len(sg);
-		addr = sg_dma_address(sg);
-
-		while (pages && page_len > 0) {
-			if (WARN_ON(page_index >= max_entries))
+	if (pages) {
+		for_each_sgtable_page(sgt, &page_iter, 0) {
+			if (p - pages >= max_entries)
 				return -1;
-			pages[page_index] = page;
-			page++;
-			page_len -= PAGE_SIZE;
-			page_index++;
+			*p++ = sg_page_iter_page(&page_iter);
 		}
-		while (addrs && dma_len > 0) {
-			if (WARN_ON(dma_index >= max_entries))
+	}
+	if (addrs) {
+		for_each_sgtable_dma_page(sgt, &dma_iter, 0) {
+			if (a - addrs >= max_entries)
 				return -1;
-			addrs[dma_index] = addr;
-			addr += PAGE_SIZE;
-			dma_len -= PAGE_SIZE;
-			dma_index++;
+			*a++ = sg_page_iter_dma_address(&dma_iter);
 		}
 	}
+
 	return 0;
 }
 EXPORT_SYMBOL(drm_prime_sg_to_page_addr_arrays);
-- 
2.17.1

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[PATCH v6 03/36] drm: core: fix common struct sg_table related issues

[Marek Szyprowski]

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/gpu/drm/drm_cache.c            |  2 +-
 drivers/gpu/drm/drm_gem_shmem_helper.c | 14 +++++++++-----
 drivers/gpu/drm/drm_prime.c            | 11 ++++++-----
 3 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/drm_cache.c b/drivers/gpu/drm/drm_cache.c
index 03e01b000f7a..0fe3c496002a 100644
--- a/drivers/gpu/drm/drm_cache.c
+++ b/drivers/gpu/drm/drm_cache.c
@@ -127,7 +127,7 @@ drm_clflush_sg(struct sg_table *st)
 		struct sg_page_iter sg_iter;
 
 		mb(); /*CLFLUSH is ordered only by using memory barriers*/
-		for_each_sg_page(st->sgl, &sg_iter, st->nents, 0)
+		for_each_sgtable_page(st, &sg_iter, 0)
 			drm_clflush_page(sg_page_iter_page(&sg_iter));
 		mb(); /*Make sure that all cache line entry is flushed*/
 
diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 4b7cfbac4daa..47d8211221f2 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -126,8 +126,8 @@ void drm_gem_shmem_free_object(struct drm_gem_object *obj)
 		drm_prime_gem_destroy(obj, shmem->sgt);
 	} else {
 		if (shmem->sgt) {
-			dma_unmap_sg(obj->dev->dev, shmem->sgt->sgl,
-				     shmem->sgt->nents, DMA_BIDIRECTIONAL);
+			dma_unmap_sgtable(obj->dev->dev, shmem->sgt,
+					  DMA_BIDIRECTIONAL, 0);
 			sg_free_table(shmem->sgt);
 			kfree(shmem->sgt);
 		}
@@ -424,8 +424,7 @@ void drm_gem_shmem_purge_locked(struct drm_gem_object *obj)
 
 	WARN_ON(!drm_gem_shmem_is_purgeable(shmem));
 
-	dma_unmap_sg(obj->dev->dev, shmem->sgt->sgl,
-		     shmem->sgt->nents, DMA_BIDIRECTIONAL);
+	dma_unmap_sgtable(obj->dev->dev, shmem->sgt, DMA_BIDIRECTIONAL, 0);
 	sg_free_table(shmem->sgt);
 	kfree(shmem->sgt);
 	shmem->sgt = NULL;
@@ -697,12 +696,17 @@ struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_object *obj)
 		goto err_put_pages;
 	}
 	/* Map the pages for use by the h/w. */
-	dma_map_sg(obj->dev->dev, sgt->sgl, sgt->nents, DMA_BIDIRECTIONAL);
+	ret = dma_map_sgtable(obj->dev->dev, sgt, DMA_BIDIRECTIONAL, 0);
+	if (ret)
+		goto err_free_sgt;
 
 	shmem->sgt = sgt;
 
 	return sgt;
 
+err_free_sgt:
+	sg_free_table(sgt);
+	kfree(sgt);
 err_put_pages:
 	drm_gem_shmem_put_pages(shmem);
 	return ERR_PTR(ret);
diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 22953ee1e2ba..dc2efa8a8dd3 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -617,6 +617,7 @@ struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach,
 {
 	struct drm_gem_object *obj = attach->dmabuf->priv;
 	struct sg_table *sgt;
+	int ret;
 
 	if (WARN_ON(dir == DMA_NONE))
 		return ERR_PTR(-EINVAL);
@@ -626,11 +627,12 @@ struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach,
 	else
 		sgt = obj->dev->driver->gem_prime_get_sg_table(obj);
 
-	if (!dma_map_sg_attrs(attach->dev, sgt->sgl, sgt->nents, dir,
-			      DMA_ATTR_SKIP_CPU_SYNC)) {
+	ret = dma_map_sgtable(attach->dev, sgt, dir,
+			      DMA_ATTR_SKIP_CPU_SYNC);
+	if (ret) {
 		sg_free_table(sgt);
 		kfree(sgt);
-		sgt = ERR_PTR(-ENOMEM);
+		sgt = ERR_PTR(ret);
 	}
 
 	return sgt;
@@ -652,8 +654,7 @@ void drm_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
 	if (!sgt)
 		return;
 
-	dma_unmap_sg_attrs(attach->dev, sgt->sgl, sgt->nents, dir,
-			   DMA_ATTR_SKIP_CPU_SYNC);
+	dma_unmap_sgtable(attach->dev, sgt, dir, DMA_ATTR_SKIP_CPU_SYNC);
 	sg_free_table(sgt);
 	kfree(sgt);
 }
-- 
2.17.1

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[PATCH v6 04/36] drm: amdgpu: fix common struct sg_table related issues

[Marek Szyprowski]

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c  | 6 +++---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c      | 9 +++------
 drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 8 ++++----
 3 files changed, 10 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
index 43d8ed7dbd00..519ce4427fce 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
@@ -307,8 +307,8 @@ static struct sg_table *amdgpu_dma_buf_map(struct dma_buf_attachment *attach,
 		if (IS_ERR(sgt))
 			return sgt;
 
-		if (!dma_map_sg_attrs(attach->dev, sgt->sgl, sgt->nents, dir,
-				      DMA_ATTR_SKIP_CPU_SYNC))
+		if (dma_map_sgtable(attach->dev, sgt, dir,
+				    DMA_ATTR_SKIP_CPU_SYNC))
 			goto error_free;
 		break;
 
@@ -349,7 +349,7 @@ static void amdgpu_dma_buf_unmap(struct dma_buf_attachment *attach,
 	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
 
 	if (sgt->sgl->page_link) {
-		dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir);
+		dma_unmap_sgtable(attach->dev, sgt, dir, 0);
 		sg_free_table(sgt);
 		kfree(sgt);
 	} else {
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 5129a996e941..97fb73e5a6ae 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -1025,7 +1025,6 @@ static int amdgpu_ttm_tt_pin_userptr(struct ttm_tt *ttm)
 {
 	struct amdgpu_device *adev = amdgpu_ttm_adev(ttm->bdev);
 	struct amdgpu_ttm_tt *gtt = (void *)ttm;
-	unsigned nents;
 	int r;
 
 	int write = !(gtt->userflags & AMDGPU_GEM_USERPTR_READONLY);
@@ -1040,9 +1039,8 @@ static int amdgpu_ttm_tt_pin_userptr(struct ttm_tt *ttm)
 		goto release_sg;
 
 	/* Map SG to device */
-	r = -ENOMEM;
-	nents = dma_map_sg(adev->dev, ttm->sg->sgl, ttm->sg->nents, direction);
-	if (nents == 0)
+	r = dma_map_sgtable(adev->dev, ttm->sg, direction, 0);
+	if (r)
 		goto release_sg;
 
 	/* convert SG to linear array of pages and dma addresses */
@@ -1073,8 +1071,7 @@ static void amdgpu_ttm_tt_unpin_userptr(struct ttm_tt *ttm)
 		return;
 
 	/* unmap the pages mapped to the device */
-	dma_unmap_sg(adev->dev, ttm->sg->sgl, ttm->sg->nents, direction);
-
+	dma_unmap_sgtable(adev->dev, ttm->sg, direction, 0);
 	sg_free_table(ttm->sg);
 
 #if IS_ENABLED(CONFIG_DRM_AMDGPU_USERPTR)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
index d399e5893170..75495a7898b9 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
@@ -477,11 +477,11 @@ int amdgpu_vram_mgr_alloc_sgt(struct amdgpu_device *adev,
 	if (r)
 		goto error_free;
 
-	for_each_sg((*sgt)->sgl, sg, num_entries, i)
+	for_each_sgtable_sg(*sgt, sg, i)
 		sg->length = 0;
 
 	node = mem->mm_node;
-	for_each_sg((*sgt)->sgl, sg, num_entries, i) {
+	for_each_sgtable_sg(*sgt, sg, i) {
 		phys_addr_t phys = (node->start << PAGE_SHIFT) +
 			adev->gmc.aper_base;
 		size_t size = node->size << PAGE_SHIFT;
@@ -501,7 +501,7 @@ int amdgpu_vram_mgr_alloc_sgt(struct amdgpu_device *adev,
 	return 0;
 
 error_unmap:
-	for_each_sg((*sgt)->sgl, sg, num_entries, i) {
+	for_each_sgtable_sg(*sgt, sg, i) {
 		if (!sg->length)
 			continue;
 
@@ -532,7 +532,7 @@ void amdgpu_vram_mgr_free_sgt(struct amdgpu_device *adev,
 	struct scatterlist *sg;
 	int i;
 
-	for_each_sg(sgt->sgl, sg, sgt->nents, i)
+	for_each_sgtable_sg(sgt, sg, i)
 		dma_unmap_resource(dev, sg->dma_address,
 				   sg->length, dir,
 				   DMA_ATTR_SKIP_CPU_SYNC);
-- 
2.17.1

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Re: [PATCH v6 04/36] drm: amdgpu: fix common struct sg_table related issues

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 9021 bytes --]

Hi Marek,

I love your patch! Perhaps something to improve:

[auto build test WARNING on next-20200618]
[also build test WARNING on v5.8-rc1]
[cannot apply to linuxtv-media/master staging/staging-testing drm-exynos/exynos-drm-next drm-intel/for-linux-next linus/master v5.8-rc1 v5.7 v5.7-rc7]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use  as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Marek-Szyprowski/DRM-fix-struct-sg_table-nents-vs-orig_nents-misuse/20200619-000417
base:    ce2cc8efd7a40cbd17841add878cb691d0ce0bba
config: alpha-allyesconfig (attached as .config)
compiler: alpha-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=alpha 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>, old ones prefixed by <<):

In file included from include/linux/dma-mapping.h:11,
from drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:25:
drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c: In function 'amdgpu_vram_mgr_alloc_sgt':
include/linux/scatterlist.h:158:17: error: '*sgt' is a pointer; did you mean to use '->'?
158 |  for_each_sg(sgt->sgl, sg, sgt->orig_nents, i)
|                 ^~
include/linux/scatterlist.h:152:22: note: in definition of macro 'for_each_sg'
152 |  for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg))
|                      ^~~~~~
>> drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:480:2: note: in expansion of macro 'for_each_sgtable_sg'
480 |  for_each_sgtable_sg(*sgt, sg, i)
|  ^~~~~~~~~~~~~~~~~~~
include/linux/scatterlist.h:158:31: error: '*sgt' is a pointer; did you mean to use '->'?
158 |  for_each_sg(sgt->sgl, sg, sgt->orig_nents, i)
|                               ^~
include/linux/scatterlist.h:152:38: note: in definition of macro 'for_each_sg'
152 |  for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg))
|                                      ^~
>> drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:480:2: note: in expansion of macro 'for_each_sgtable_sg'
480 |  for_each_sgtable_sg(*sgt, sg, i)
|  ^~~~~~~~~~~~~~~~~~~
include/linux/scatterlist.h:158:17: error: '*sgt' is a pointer; did you mean to use '->'?
158 |  for_each_sg(sgt->sgl, sg, sgt->orig_nents, i)
|                 ^~
include/linux/scatterlist.h:152:22: note: in definition of macro 'for_each_sg'
152 |  for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg))
|                      ^~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:484:2: note: in expansion of macro 'for_each_sgtable_sg'
484 |  for_each_sgtable_sg(*sgt, sg, i) {
|  ^~~~~~~~~~~~~~~~~~~
include/linux/scatterlist.h:158:31: error: '*sgt' is a pointer; did you mean to use '->'?
158 |  for_each_sg(sgt->sgl, sg, sgt->orig_nents, i)
|                               ^~
include/linux/scatterlist.h:152:38: note: in definition of macro 'for_each_sg'
152 |  for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg))
|                                      ^~
drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:484:2: note: in expansion of macro 'for_each_sgtable_sg'
484 |  for_each_sgtable_sg(*sgt, sg, i) {
|  ^~~~~~~~~~~~~~~~~~~
include/linux/scatterlist.h:158:17: error: '*sgt' is a pointer; did you mean to use '->'?
158 |  for_each_sg(sgt->sgl, sg, sgt->orig_nents, i)
|                 ^~
include/linux/scatterlist.h:152:22: note: in definition of macro 'for_each_sg'
152 |  for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg))
|                      ^~~~~~
drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:504:2: note: in expansion of macro 'for_each_sgtable_sg'
504 |  for_each_sgtable_sg(*sgt, sg, i) {
|  ^~~~~~~~~~~~~~~~~~~
include/linux/scatterlist.h:158:31: error: '*sgt' is a pointer; did you mean to use '->'?
158 |  for_each_sg(sgt->sgl, sg, sgt->orig_nents, i)
|                               ^~
include/linux/scatterlist.h:152:38: note: in definition of macro 'for_each_sg'
152 |  for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg))
|                                      ^~
drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:504:2: note: in expansion of macro 'for_each_sgtable_sg'
504 |  for_each_sgtable_sg(*sgt, sg, i) {
|  ^~~~~~~~~~~~~~~~~~~
In file included from drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:26:
At top level:
drivers/gpu/drm/amd/amdgpu/amdgpu.h:190:18: warning: 'sched_policy' defined but not used [-Wunused-const-variable=]
190 | static const int sched_policy = KFD_SCHED_POLICY_HWS;
|                  ^~~~~~~~~~~~
In file included from drivers/gpu/drm/amd/amdgpu/../display/dc/dc_types.h:33,
from drivers/gpu/drm/amd/amdgpu/../display/dc/dm_services_types.h:30,
from drivers/gpu/drm/amd/amdgpu/../include/dm_pp_interface.h:26,
from drivers/gpu/drm/amd/amdgpu/amdgpu.h:65,
from drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:26:
drivers/gpu/drm/amd/amdgpu/../display/include/fixed31_32.h:76:32: warning: 'dc_fixpt_ln2_div_2' defined but not used [-Wunused-const-variable=]
76 | static const struct fixed31_32 dc_fixpt_ln2_div_2 = { 1488522236LL };
|                                ^~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/../display/include/fixed31_32.h:75:32: warning: 'dc_fixpt_ln2' defined but not used [-Wunused-const-variable=]
75 | static const struct fixed31_32 dc_fixpt_ln2 = { 2977044471LL };
|                                ^~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/../display/include/fixed31_32.h:74:32: warning: 'dc_fixpt_e' defined but not used [-Wunused-const-variable=]
74 | static const struct fixed31_32 dc_fixpt_e = { 11674931555LL };
|                                ^~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/../display/include/fixed31_32.h:73:32: warning: 'dc_fixpt_two_pi' defined but not used [-Wunused-const-variable=]
73 | static const struct fixed31_32 dc_fixpt_two_pi = { 26986075409LL };
|                                ^~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/../display/include/fixed31_32.h:72:32: warning: 'dc_fixpt_pi' defined but not used [-Wunused-const-variable=]
72 | static const struct fixed31_32 dc_fixpt_pi = { 13493037705LL };
|                                ^~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/../display/include/fixed31_32.h:67:32: warning: 'dc_fixpt_zero' defined but not used [-Wunused-const-variable=]
67 | static const struct fixed31_32 dc_fixpt_zero = { 0 };
|                                ^~~~~~~~~~~~~

vim +/for_each_sgtable_sg +480 drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c

   444	
   445	/**
   446	 * amdgpu_vram_mgr_alloc_sgt - allocate and fill a sg table
   447	 *
   448	 * @adev: amdgpu device pointer
   449	 * @mem: TTM memory object
   450	 * @dev: the other device
   451	 * @dir: dma direction
   452	 * @sgt: resulting sg table
   453	 *
   454	 * Allocate and fill a sg table from a VRAM allocation.
   455	 */
   456	int amdgpu_vram_mgr_alloc_sgt(struct amdgpu_device *adev,
   457				      struct ttm_mem_reg *mem,
   458				      struct device *dev,
   459				      enum dma_data_direction dir,
   460				      struct sg_table **sgt)
   461	{
   462		struct drm_mm_node *node;
   463		struct scatterlist *sg;
   464		int num_entries = 0;
   465		unsigned int pages;
   466		int i, r;
   467	
   468		*sgt = kmalloc(sizeof(*sg), GFP_KERNEL);
   469		if (!*sgt)
   470			return -ENOMEM;
   471	
   472		for (pages = mem->num_pages, node = mem->mm_node;
   473		     pages; pages -= node->size, ++node)
   474			++num_entries;
   475	
   476		r = sg_alloc_table(*sgt, num_entries, GFP_KERNEL);
   477		if (r)
   478			goto error_free;
   479	
 > 480		for_each_sgtable_sg(*sgt, sg, i)
   481			sg->length = 0;
   482	
   483		node = mem->mm_node;
   484		for_each_sgtable_sg(*sgt, sg, i) {
   485			phys_addr_t phys = (node->start << PAGE_SHIFT) +
   486				adev->gmc.aper_base;
   487			size_t size = node->size << PAGE_SHIFT;
   488			dma_addr_t addr;
   489	
   490			++node;
   491			addr = dma_map_resource(dev, phys, size, dir,
   492						DMA_ATTR_SKIP_CPU_SYNC);
   493			r = dma_mapping_error(dev, addr);
   494			if (r)
   495				goto error_unmap;
   496	
   497			sg_set_page(sg, NULL, size, 0);
   498			sg_dma_address(sg) = addr;
   499			sg_dma_len(sg) = size;
   500		}
   501		return 0;
   502	
   503	error_unmap:
   504		for_each_sgtable_sg(*sgt, sg, i) {
   505			if (!sg->length)
   506				continue;
   507	
   508			dma_unmap_resource(dev, sg->dma_address,
   509					   sg->length, dir,
   510					   DMA_ATTR_SKIP_CPU_SYNC);
   511		}
   512		sg_free_table(*sgt);
   513	
   514	error_free:
   515		kfree(*sgt);
   516		return r;
   517	}
   518	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 65125 bytes --]

[-- Attachment #3: Type: text/plain, Size: 156 bytes --]

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[PATCH v6 05/36] drm: armada: fix common struct sg_table related issues

[Marek Szyprowski]

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/gpu/drm/armada/armada_gem.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/armada/armada_gem.c b/drivers/gpu/drm/armada/armada_gem.c
index 8005614d2e6b..bedd8937d8a1 100644
--- a/drivers/gpu/drm/armada/armada_gem.c
+++ b/drivers/gpu/drm/armada/armada_gem.c
@@ -395,7 +395,7 @@ armada_gem_prime_map_dma_buf(struct dma_buf_attachment *attach,
 
 		mapping = dobj->obj.filp->f_mapping;
 
-		for_each_sg(sgt->sgl, sg, count, i) {
+		for_each_sgtable_sg(sgt, sg, i) {
 			struct page *page;
 
 			page = shmem_read_mapping_page(mapping, i);
@@ -407,8 +407,8 @@ armada_gem_prime_map_dma_buf(struct dma_buf_attachment *attach,
 			sg_set_page(sg, page, PAGE_SIZE, 0);
 		}
 
-		if (dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir) == 0) {
-			num = sgt->nents;
+		if (dma_map_sgtable(attach->dev, sgt, dir, 0)) {
+			num = count;
 			goto release;
 		}
 	} else if (dobj->page) {
@@ -418,7 +418,7 @@ armada_gem_prime_map_dma_buf(struct dma_buf_attachment *attach,
 
 		sg_set_page(sgt->sgl, dobj->page, dobj->obj.size, 0);
 
-		if (dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir) == 0)
+		if (dma_map_sgtable(attach->dev, sgt, dir, 0))
 			goto free_table;
 	} else if (dobj->linear) {
 		/* Single contiguous physical region - no struct page */
@@ -449,11 +449,11 @@ static void armada_gem_prime_unmap_dma_buf(struct dma_buf_attachment *attach,
 	int i;
 
 	if (!dobj->linear)
-		dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir);
+		dma_unmap_sgtable(attach->dev, sgt, dir, 0);
 
 	if (dobj->obj.filp) {
 		struct scatterlist *sg;
-		for_each_sg(sgt->sgl, sg, sgt->nents, i)
+		for_each_sgtable_sg(sgt, sg, i)
 			put_page(sg_page(sg));
 	}
 
-- 
2.17.1

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[PATCH v6 06/36] drm: etnaviv: fix common struct sg_table related issues

[Marek Szyprowski]

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/gpu/drm/etnaviv/etnaviv_gem.c | 12 +++++-------
 drivers/gpu/drm/etnaviv/etnaviv_mmu.c | 13 +++----------
 2 files changed, 8 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
index f5e5bb8ba953..9f4613f7e255 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
@@ -27,7 +27,7 @@ static void etnaviv_gem_scatter_map(struct etnaviv_gem_object *etnaviv_obj)
 	 * because display controller, GPU, etc. are not coherent.
 	 */
 	if (etnaviv_obj->flags & ETNA_BO_CACHE_MASK)
-		dma_map_sg(dev->dev, sgt->sgl, sgt->nents, DMA_BIDIRECTIONAL);
+		dma_map_sgtable(dev->dev, sgt, DMA_BIDIRECTIONAL, 0);
 }
 
 static void etnaviv_gem_scatterlist_unmap(struct etnaviv_gem_object *etnaviv_obj)
@@ -51,7 +51,7 @@ static void etnaviv_gem_scatterlist_unmap(struct etnaviv_gem_object *etnaviv_obj
 	 * discard those writes.
 	 */
 	if (etnaviv_obj->flags & ETNA_BO_CACHE_MASK)
-		dma_unmap_sg(dev->dev, sgt->sgl, sgt->nents, DMA_BIDIRECTIONAL);
+		dma_unmap_sgtable(dev->dev, sgt, DMA_BIDIRECTIONAL, 0);
 }
 
 /* called with etnaviv_obj->lock held */
@@ -404,9 +404,8 @@ int etnaviv_gem_cpu_prep(struct drm_gem_object *obj, u32 op,
 	}
 
 	if (etnaviv_obj->flags & ETNA_BO_CACHED) {
-		dma_sync_sg_for_cpu(dev->dev, etnaviv_obj->sgt->sgl,
-				    etnaviv_obj->sgt->nents,
-				    etnaviv_op_to_dma_dir(op));
+		dma_sync_sgtable_for_cpu(dev->dev, etnaviv_obj->sgt,
+					 etnaviv_op_to_dma_dir(op));
 		etnaviv_obj->last_cpu_prep_op = op;
 	}
 
@@ -421,8 +420,7 @@ int etnaviv_gem_cpu_fini(struct drm_gem_object *obj)
 	if (etnaviv_obj->flags & ETNA_BO_CACHED) {
 		/* fini without a prep is almost certainly a userspace error */
 		WARN_ON(etnaviv_obj->last_cpu_prep_op == 0);
-		dma_sync_sg_for_device(dev->dev, etnaviv_obj->sgt->sgl,
-			etnaviv_obj->sgt->nents,
+		dma_sync_sgtable_for_device(dev->dev, etnaviv_obj->sgt,
 			etnaviv_op_to_dma_dir(etnaviv_obj->last_cpu_prep_op));
 		etnaviv_obj->last_cpu_prep_op = 0;
 	}
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_mmu.c b/drivers/gpu/drm/etnaviv/etnaviv_mmu.c
index 3607d348c298..13b100553a0b 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_mmu.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_mmu.c
@@ -79,7 +79,7 @@ static int etnaviv_iommu_map(struct etnaviv_iommu_context *context, u32 iova,
 	if (!context || !sgt)
 		return -EINVAL;
 
-	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
+	for_each_sgtable_dma_sg(sgt, sg, i) {
 		u32 pa = sg_dma_address(sg) - sg->offset;
 		size_t bytes = sg_dma_len(sg) + sg->offset;
 
@@ -95,14 +95,7 @@ static int etnaviv_iommu_map(struct etnaviv_iommu_context *context, u32 iova,
 	return 0;
 
 fail:
-	da = iova;
-
-	for_each_sg(sgt->sgl, sg, i, j) {
-		size_t bytes = sg_dma_len(sg) + sg->offset;
-
-		etnaviv_context_unmap(context, da, bytes);
-		da += bytes;
-	}
+	etnaviv_context_unmap(context, iova, da - iova);
 	return ret;
 }
 
@@ -113,7 +106,7 @@ static void etnaviv_iommu_unmap(struct etnaviv_iommu_context *context, u32 iova,
 	unsigned int da = iova;
 	int i;
 
-	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
+	for_each_sgtable_dma_sg(sgt, sg, i) {
 		size_t bytes = sg_dma_len(sg) + sg->offset;
 
 		etnaviv_context_unmap(context, da, bytes);
-- 
2.17.1

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[PATCH v6 07/36] drm: exynos: use common helper for a scatterlist contiguity check

[Marek Szyprowski]

Use common helper for checking the contiguity of the imported dma-buf.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/gpu/drm/exynos/exynos_drm_gem.c | 23 +++--------------------
 1 file changed, 3 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c b/drivers/gpu/drm/exynos/exynos_drm_gem.c
index efa476858db5..1716a023bca0 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_gem.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c
@@ -431,27 +431,10 @@ exynos_drm_gem_prime_import_sg_table(struct drm_device *dev,
 {
 	struct exynos_drm_gem *exynos_gem;
 
-	if (sgt->nents < 1)
+	/* check if the entries in the sg_table are contiguous */
+	if (drm_prime_get_contiguous_size(sgt) < attach->dmabuf->size) {
+		DRM_ERROR("buffer chunks must be mapped contiguously");
 		return ERR_PTR(-EINVAL);
-
-	/*
-	 * Check if the provided buffer has been mapped as contiguous
-	 * into DMA address space.
-	 */
-	if (sgt->nents > 1) {
-		dma_addr_t next_addr = sg_dma_address(sgt->sgl);
-		struct scatterlist *s;
-		unsigned int i;
-
-		for_each_sg(sgt->sgl, s, sgt->nents, i) {
-			if (!sg_dma_len(s))
-				break;
-			if (sg_dma_address(s) != next_addr) {
-				DRM_ERROR("buffer chunks must be mapped contiguously");
-				return ERR_PTR(-EINVAL);
-			}
-			next_addr = sg_dma_address(s) + sg_dma_len(s);
-		}
 	}
 
 	exynos_gem = exynos_drm_gem_init(dev, attach->dmabuf->size);
-- 
2.17.1

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[PATCH v6 08/36] drm: exynos: fix common struct sg_table related issues

[Marek Szyprowski]

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/gpu/drm/exynos/exynos_drm_g2d.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_g2d.c b/drivers/gpu/drm/exynos/exynos_drm_g2d.c
index fcee33a43aca..7014a8cd971a 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_g2d.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_g2d.c
@@ -395,8 +395,8 @@ static void g2d_userptr_put_dma_addr(struct g2d_data *g2d,
 		return;
 
 out:
-	dma_unmap_sg(to_dma_dev(g2d->drm_dev), g2d_userptr->sgt->sgl,
-			g2d_userptr->sgt->nents, DMA_BIDIRECTIONAL);
+	dma_unmap_sgtable(to_dma_dev(g2d->drm_dev), g2d_userptr->sgt,
+			  DMA_BIDIRECTIONAL, 0);
 
 	pages = frame_vector_pages(g2d_userptr->vec);
 	if (!IS_ERR(pages)) {
@@ -511,10 +511,10 @@ static dma_addr_t *g2d_userptr_get_dma_addr(struct g2d_data *g2d,
 
 	g2d_userptr->sgt = sgt;
 
-	if (!dma_map_sg(to_dma_dev(g2d->drm_dev), sgt->sgl, sgt->nents,
-				DMA_BIDIRECTIONAL)) {
+	ret = dma_map_sgtable(to_dma_dev(g2d->drm_dev), sgt,
+			      DMA_BIDIRECTIONAL, 0);
+	if (ret) {
 		DRM_DEV_ERROR(g2d->dev, "failed to map sgt with dma region.\n");
-		ret = -ENOMEM;
 		goto err_sg_free_table;
 	}
 
-- 
2.17.1

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[PATCH v6 09/36] drm: i915: fix common struct sg_table related issues

[Marek Szyprowski]

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

This driver creatively uses sg_table->orig_nents to store the size of the
allocated scatterlist and ignores the number of the entries returned by
dma_map_sg function. The sg_table->orig_nents is (mis)used to properly
free the (over)allocated scatterlist.

This patch only introduces the common DMA-mapping wrappers operating
directly on the struct sg_table objects to the dmabuf related functions,
so the other drivers, which might share buffers with i915 could rely on
the properly set nents and orig_nents values.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c       | 11 +++--------
 drivers/gpu/drm/i915/gem/selftests/mock_dmabuf.c |  7 +++----
 2 files changed, 6 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
index 2679380159fc..8a988592715b 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
@@ -48,12 +48,9 @@ static struct sg_table *i915_gem_map_dma_buf(struct dma_buf_attachment *attachme
 		src = sg_next(src);
 	}
 
-	if (!dma_map_sg_attrs(attachment->dev,
-			      st->sgl, st->nents, dir,
-			      DMA_ATTR_SKIP_CPU_SYNC)) {
-		ret = -ENOMEM;
+	ret = dma_map_sgtable(attachment->dev, st, dir, DMA_ATTR_SKIP_CPU_SYNC);
+	if (ret)
 		goto err_free_sg;
-	}
 
 	return st;
 
@@ -73,9 +70,7 @@ static void i915_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
 {
 	struct drm_i915_gem_object *obj = dma_buf_to_obj(attachment->dmabuf);
 
-	dma_unmap_sg_attrs(attachment->dev,
-			   sg->sgl, sg->nents, dir,
-			   DMA_ATTR_SKIP_CPU_SYNC);
+	dma_unmap_sgtable(attachment->dev, sg, dir, DMA_ATTR_SKIP_CPU_SYNC);
 	sg_free_table(sg);
 	kfree(sg);
 
diff --git a/drivers/gpu/drm/i915/gem/selftests/mock_dmabuf.c b/drivers/gpu/drm/i915/gem/selftests/mock_dmabuf.c
index debaf7b18ab5..be30b27e2926 100644
--- a/drivers/gpu/drm/i915/gem/selftests/mock_dmabuf.c
+++ b/drivers/gpu/drm/i915/gem/selftests/mock_dmabuf.c
@@ -28,10 +28,9 @@ static struct sg_table *mock_map_dma_buf(struct dma_buf_attachment *attachment,
 		sg = sg_next(sg);
 	}
 
-	if (!dma_map_sg(attachment->dev, st->sgl, st->nents, dir)) {
-		err = -ENOMEM;
+	err = dma_map_sgtable(attachment->dev, st, dir, 0);
+	if (err)
 		goto err_st;
-	}
 
 	return st;
 
@@ -46,7 +45,7 @@ static void mock_unmap_dma_buf(struct dma_buf_attachment *attachment,
 			       struct sg_table *st,
 			       enum dma_data_direction dir)
 {
-	dma_unmap_sg(attachment->dev, st->sgl, st->nents, dir);
+	dma_unmap_sgtable(attachment->dev, st, dir, 0);
 	sg_free_table(st);
 	kfree(st);
 }
-- 
2.17.1

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[PATCH v6 10/36] drm: lima: fix common struct sg_table related issues

[Marek Szyprowski]

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Qiang Yu <yuq825@gmail.com>
---
 drivers/gpu/drm/lima/lima_gem.c | 11 ++++++++---
 drivers/gpu/drm/lima/lima_vm.c  |  5 ++---
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/lima/lima_gem.c b/drivers/gpu/drm/lima/lima_gem.c
index 155f2b4b4030..11223fe348df 100644
--- a/drivers/gpu/drm/lima/lima_gem.c
+++ b/drivers/gpu/drm/lima/lima_gem.c
@@ -69,8 +69,7 @@ int lima_heap_alloc(struct lima_bo *bo, struct lima_vm *vm)
 		return ret;
 
 	if (bo->base.sgt) {
-		dma_unmap_sg(dev, bo->base.sgt->sgl,
-			     bo->base.sgt->nents, DMA_BIDIRECTIONAL);
+		dma_unmap_sgtable(dev, bo->base.sgt, DMA_BIDIRECTIONAL, 0);
 		sg_free_table(bo->base.sgt);
 	} else {
 		bo->base.sgt = kmalloc(sizeof(*bo->base.sgt), GFP_KERNEL);
@@ -80,7 +79,13 @@ int lima_heap_alloc(struct lima_bo *bo, struct lima_vm *vm)
 		}
 	}
 
-	dma_map_sg(dev, sgt.sgl, sgt.nents, DMA_BIDIRECTIONAL);
+	ret = dma_map_sgtable(dev, &sgt, DMA_BIDIRECTIONAL, 0);
+	if (ret) {
+		sg_free_table(&sgt);
+		kfree(bo->base.sgt);
+		bo->base.sgt = NULL;
+		return ret;
+	}
 
 	*bo->base.sgt = sgt;
 
diff --git a/drivers/gpu/drm/lima/lima_vm.c b/drivers/gpu/drm/lima/lima_vm.c
index 5b92fb82674a..2b2739adc7f5 100644
--- a/drivers/gpu/drm/lima/lima_vm.c
+++ b/drivers/gpu/drm/lima/lima_vm.c
@@ -124,7 +124,7 @@ int lima_vm_bo_add(struct lima_vm *vm, struct lima_bo *bo, bool create)
 	if (err)
 		goto err_out1;
 
-	for_each_sg_dma_page(bo->base.sgt->sgl, &sg_iter, bo->base.sgt->nents, 0) {
+	for_each_sgtable_dma_page(bo->base.sgt, &sg_iter, 0) {
 		err = lima_vm_map_page(vm, sg_page_iter_dma_address(&sg_iter),
 				       bo_va->node.start + offset);
 		if (err)
@@ -298,8 +298,7 @@ int lima_vm_map_bo(struct lima_vm *vm, struct lima_bo *bo, int pageoff)
 	mutex_lock(&vm->lock);
 
 	base = bo_va->node.start + (pageoff << PAGE_SHIFT);
-	for_each_sg_dma_page(bo->base.sgt->sgl, &sg_iter,
-			     bo->base.sgt->nents, pageoff) {
+	for_each_sgtable_dma_page(bo->base.sgt, &sg_iter, pageoff) {
 		err = lima_vm_map_page(vm, sg_page_iter_dma_address(&sg_iter),
 				       base + offset);
 		if (err)
-- 
2.17.1

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[PATCH v6 11/36] drm: mediatek: use common helper for a scatterlist contiguity check

[Marek Szyprowski]

Use common helper for checking the contiguity of the imported dma-buf and
do this check before allocating resources, so the error path is simpler.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/gpu/drm/mediatek/mtk_drm_gem.c | 28 ++++++--------------------
 1 file changed, 6 insertions(+), 22 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_gem.c b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
index 6190cc3b7b0d..3654ec732029 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_gem.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
@@ -212,37 +212,21 @@ struct drm_gem_object *mtk_gem_prime_import_sg_table(struct drm_device *dev,
 			struct dma_buf_attachment *attach, struct sg_table *sg)
 {
 	struct mtk_drm_gem_obj *mtk_gem;
-	int ret;
-	struct scatterlist *s;
-	unsigned int i;
-	dma_addr_t expected;
 
-	mtk_gem = mtk_drm_gem_init(dev, attach->dmabuf->size);
+	/* check if the entries in the sg_table are contiguous */
+	if (drm_prime_get_contiguous_size(sg) < attach->dmabuf->size) {
+		DRM_ERROR("sg_table is not contiguous");
+		return ERR_PTR(-EINVAL);
+	}
 
+	mtk_gem = mtk_drm_gem_init(dev, attach->dmabuf->size);
 	if (IS_ERR(mtk_gem))
 		return ERR_CAST(mtk_gem);
 
-	expected = sg_dma_address(sg->sgl);
-	for_each_sg(sg->sgl, s, sg->nents, i) {
-		if (!sg_dma_len(s))
-			break;
-
-		if (sg_dma_address(s) != expected) {
-			DRM_ERROR("sg_table is not contiguous");
-			ret = -EINVAL;
-			goto err_gem_free;
-		}
-		expected = sg_dma_address(s) + sg_dma_len(s);
-	}
-
 	mtk_gem->dma_addr = sg_dma_address(sg->sgl);
 	mtk_gem->sg = sg;
 
 	return &mtk_gem->base;
-
-err_gem_free:
-	kfree(mtk_gem);
-	return ERR_PTR(ret);
 }
 
 void *mtk_drm_gem_prime_vmap(struct drm_gem_object *obj)
-- 
2.17.1

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[PATCH v6 12/36] drm: mediatek: use common helper for extracting pages array

[Marek Szyprowski]

Use common helper for converting a sg_table object into struct
page pointer array.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/gpu/drm/mediatek/mtk_drm_gem.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_gem.c b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
index 3654ec732029..0583e557ad37 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_gem.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
@@ -233,9 +233,7 @@ void *mtk_drm_gem_prime_vmap(struct drm_gem_object *obj)
 {
 	struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
 	struct sg_table *sgt;
-	struct sg_page_iter iter;
 	unsigned int npages;
-	unsigned int i = 0;
 
 	if (mtk_gem->kvaddr)
 		return mtk_gem->kvaddr;
@@ -249,11 +247,8 @@ void *mtk_drm_gem_prime_vmap(struct drm_gem_object *obj)
 	if (!mtk_gem->pages)
 		goto out;
 
-	for_each_sg_page(sgt->sgl, &iter, sgt->orig_nents, 0) {
-		mtk_gem->pages[i++] = sg_page_iter_page(&iter);
-		if (i > npages)
-			break;
-	}
+	drm_prime_sg_to_page_addr_arrays(sgt, mtk_gem->pages, NULL, npages);
+
 	mtk_gem->kvaddr = vmap(mtk_gem->pages, npages, VM_MAP,
 			       pgprot_writecombine(PAGE_KERNEL));
 
-- 
2.17.1

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[PATCH v6 13/36] drm: msm: fix common struct sg_table related issues

[Marek Szyprowski]

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/gpu/drm/msm/msm_gem.c    | 13 +++++--------
 drivers/gpu/drm/msm/msm_gpummu.c | 14 ++++++--------
 drivers/gpu/drm/msm/msm_iommu.c  |  2 +-
 3 files changed, 12 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index 38b0c0e1f83e..e0d5fd36ea8f 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -53,11 +53,10 @@ static void sync_for_device(struct msm_gem_object *msm_obj)
 	struct device *dev = msm_obj->base.dev->dev;
 
 	if (get_dma_ops(dev) && IS_ENABLED(CONFIG_ARM64)) {
-		dma_sync_sg_for_device(dev, msm_obj->sgt->sgl,
-			msm_obj->sgt->nents, DMA_BIDIRECTIONAL);
+		dma_sync_sgtable_for_device(dev, msm_obj->sgt,
+					    DMA_BIDIRECTIONAL);
 	} else {
-		dma_map_sg(dev, msm_obj->sgt->sgl,
-			msm_obj->sgt->nents, DMA_BIDIRECTIONAL);
+		dma_map_sgtable(dev, msm_obj->sgt, DMA_BIDIRECTIONAL, 0);
 	}
 }
 
@@ -66,11 +65,9 @@ static void sync_for_cpu(struct msm_gem_object *msm_obj)
 	struct device *dev = msm_obj->base.dev->dev;
 
 	if (get_dma_ops(dev) && IS_ENABLED(CONFIG_ARM64)) {
-		dma_sync_sg_for_cpu(dev, msm_obj->sgt->sgl,
-			msm_obj->sgt->nents, DMA_BIDIRECTIONAL);
+		dma_sync_sgtable_for_cpu(dev, msm_obj->sgt, DMA_BIDIRECTIONAL);
 	} else {
-		dma_unmap_sg(dev, msm_obj->sgt->sgl,
-			msm_obj->sgt->nents, DMA_BIDIRECTIONAL);
+		dma_unmap_sgtable(dev, msm_obj->sgt, DMA_BIDIRECTIONAL, 0);
 	}
 }
 
diff --git a/drivers/gpu/drm/msm/msm_gpummu.c b/drivers/gpu/drm/msm/msm_gpummu.c
index 310a31b05faa..319f06c28235 100644
--- a/drivers/gpu/drm/msm/msm_gpummu.c
+++ b/drivers/gpu/drm/msm/msm_gpummu.c
@@ -30,21 +30,19 @@ static int msm_gpummu_map(struct msm_mmu *mmu, uint64_t iova,
 {
 	struct msm_gpummu *gpummu = to_msm_gpummu(mmu);
 	unsigned idx = (iova - GPUMMU_VA_START) / GPUMMU_PAGE_SIZE;
-	struct scatterlist *sg;
+	struct sg_dma_page_iter dma_iter;
 	unsigned prot_bits = 0;
-	unsigned i, j;
 
 	if (prot & IOMMU_WRITE)
 		prot_bits |= 1;
 	if (prot & IOMMU_READ)
 		prot_bits |= 2;
 
-	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
-		dma_addr_t addr = sg->dma_address;
-		for (j = 0; j < sg->length / GPUMMU_PAGE_SIZE; j++, idx++) {
-			gpummu->table[idx] = addr | prot_bits;
-			addr += GPUMMU_PAGE_SIZE;
-		}
+	for_each_sgtable_dma_page(sgt, &dma_iter, 0) {
+		dma_addr_t addr = sg_page_iter_dma_address(&dma_iter);
+
+		BUILD_BUG_ON(GPUMMU_PAGE_SIZE != PAGE_SIZE);
+		gpummu->table[idx++] = addr | prot_bits;
 	}
 
 	/* we can improve by deferring flush for multiple map() */
diff --git a/drivers/gpu/drm/msm/msm_iommu.c b/drivers/gpu/drm/msm/msm_iommu.c
index 3a381a9674c9..6c31e65834c6 100644
--- a/drivers/gpu/drm/msm/msm_iommu.c
+++ b/drivers/gpu/drm/msm/msm_iommu.c
@@ -36,7 +36,7 @@ static int msm_iommu_map(struct msm_mmu *mmu, uint64_t iova,
 	struct msm_iommu *iommu = to_msm_iommu(mmu);
 	size_t ret;
 
-	ret = iommu_map_sg(iommu->domain, iova, sgt->sgl, sgt->nents, prot);
+	ret = iommu_map_sgtable(iommu->domain, iova, sgt, prot);
 	WARN_ON(!ret);
 
 	return (ret == len) ? 0 : -EINVAL;
-- 
2.17.1

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[PATCH v6 14/36] drm: omapdrm: use common helper for extracting pages array

[Marek Szyprowski]

Use common helper for converting a sg_table object into struct
page pointer array.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/gpu/drm/omapdrm/omap_gem.c | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/omapdrm/omap_gem.c b/drivers/gpu/drm/omapdrm/omap_gem.c
index d0d12d5dd76c..ff0c4b0c3fd0 100644
--- a/drivers/gpu/drm/omapdrm/omap_gem.c
+++ b/drivers/gpu/drm/omapdrm/omap_gem.c
@@ -1297,10 +1297,9 @@ struct drm_gem_object *omap_gem_new_dmabuf(struct drm_device *dev, size_t size,
 		omap_obj->dma_addr = sg_dma_address(sgt->sgl);
 	} else {
 		/* Create pages list from sgt */
-		struct sg_page_iter iter;
 		struct page **pages;
 		unsigned int npages;
-		unsigned int i = 0;
+		unsigned int ret;
 
 		npages = DIV_ROUND_UP(size, PAGE_SIZE);
 		pages = kcalloc(npages, sizeof(*pages), GFP_KERNEL);
@@ -1311,14 +1310,9 @@ struct drm_gem_object *omap_gem_new_dmabuf(struct drm_device *dev, size_t size,
 		}
 
 		omap_obj->pages = pages;
-
-		for_each_sg_page(sgt->sgl, &iter, sgt->orig_nents, 0) {
-			pages[i++] = sg_page_iter_page(&iter);
-			if (i > npages)
-				break;
-		}
-
-		if (WARN_ON(i != npages)) {
+		ret = drm_prime_sg_to_page_addr_arrays(sgt, pages, NULL,
+						       npages);
+		if (WARN_ON(ret)) {
 			omap_gem_free_object(obj);
 			obj = ERR_PTR(-ENOMEM);
 			goto done;
-- 
2.17.1

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[PATCH v6 15/36] drm: omapdrm: fix common struct sg_table related issues

[Marek Szyprowski]

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

Fix the code to refer to proper nents or orig_nents entries. This driver
checks for a buffer contiguity in DMA address space, so it should test
sg_table->nents entry.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/gpu/drm/omapdrm/omap_gem.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/omapdrm/omap_gem.c b/drivers/gpu/drm/omapdrm/omap_gem.c
index ff0c4b0c3fd0..a7a9a0afe2b6 100644
--- a/drivers/gpu/drm/omapdrm/omap_gem.c
+++ b/drivers/gpu/drm/omapdrm/omap_gem.c
@@ -48,7 +48,7 @@ struct omap_gem_object {
 	 *   OMAP_BO_MEM_DMA_API flag set)
 	 *
 	 * - buffers imported from dmabuf (with the OMAP_BO_MEM_DMABUF flag set)
-	 *   if they are physically contiguous (when sgt->orig_nents == 1)
+	 *   if they are physically contiguous (when sgt->nents == 1)
 	 *
 	 * - buffers mapped through the TILER when dma_addr_cnt is not zero, in
 	 *   which case the DMA address points to the TILER aperture
@@ -1279,7 +1279,7 @@ struct drm_gem_object *omap_gem_new_dmabuf(struct drm_device *dev, size_t size,
 	union omap_gem_size gsize;
 
 	/* Without a DMM only physically contiguous buffers can be supported. */
-	if (sgt->orig_nents != 1 && !priv->has_dmm)
+	if (sgt->nents != 1 && !priv->has_dmm)
 		return ERR_PTR(-EINVAL);
 
 	gsize.bytes = PAGE_ALIGN(size);
@@ -1293,7 +1293,7 @@ struct drm_gem_object *omap_gem_new_dmabuf(struct drm_device *dev, size_t size,
 
 	omap_obj->sgt = sgt;
 
-	if (sgt->orig_nents == 1) {
+	if (sgt->nents == 1) {
 		omap_obj->dma_addr = sg_dma_address(sgt->sgl);
 	} else {
 		/* Create pages list from sgt */
-- 
2.17.1

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[PATCH v6 16/36] drm: panfrost: fix common struct sg_table related issues

[Marek Szyprowski]

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 drivers/gpu/drm/panfrost/panfrost_gem.c | 4 ++--
 drivers/gpu/drm/panfrost/panfrost_mmu.c | 7 +++----
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c
index ac5d0aa80276..ba8450ea04d0 100644
--- a/drivers/gpu/drm/panfrost/panfrost_gem.c
+++ b/drivers/gpu/drm/panfrost/panfrost_gem.c
@@ -41,8 +41,8 @@ static void panfrost_gem_free_object(struct drm_gem_object *obj)
 
 		for (i = 0; i < n_sgt; i++) {
 			if (bo->sgts[i].sgl) {
-				dma_unmap_sg(pfdev->dev, bo->sgts[i].sgl,
-					     bo->sgts[i].nents, DMA_BIDIRECTIONAL);
+				dma_unmap_sgtable(pfdev->dev, &bo->sgts[i],
+						  DMA_BIDIRECTIONAL, 0);
 				sg_free_table(&bo->sgts[i]);
 			}
 		}
diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
index 0a339c6fbfaa..fd294f6a7d3b 100644
--- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
+++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
@@ -253,7 +253,7 @@ static int mmu_map_sg(struct panfrost_device *pfdev, struct panfrost_mmu *mmu,
 	struct io_pgtable_ops *ops = mmu->pgtbl_ops;
 	u64 start_iova = iova;
 
-	for_each_sg(sgt->sgl, sgl, sgt->nents, count) {
+	for_each_sgtable_dma_sg(sgt, sgl, count) {
 		unsigned long paddr = sg_dma_address(sgl);
 		size_t len = sg_dma_len(sgl);
 
@@ -517,10 +517,9 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
 	if (ret)
 		goto err_pages;
 
-	if (!dma_map_sg(pfdev->dev, sgt->sgl, sgt->nents, DMA_BIDIRECTIONAL)) {
-		ret = -EINVAL;
+	ret = dma_map_sgtable(pfdev->dev, sgt, DMA_BIDIRECTIONAL, 0);
+	if (ret)
 		goto err_map;
-	}
 
 	mmu_map_sg(pfdev, bomapping->mmu, addr,
 		   IOMMU_WRITE | IOMMU_READ | IOMMU_NOEXEC, sgt);
-- 
2.17.1

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[PATCH v6 17/36] drm: radeon: fix common struct sg_table related issues

[Marek Szyprowski]

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
---
 drivers/gpu/drm/radeon/radeon_ttm.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c
index 5d50c9edbe80..0e3eb0d22831 100644
--- a/drivers/gpu/drm/radeon/radeon_ttm.c
+++ b/drivers/gpu/drm/radeon/radeon_ttm.c
@@ -481,7 +481,7 @@ static int radeon_ttm_tt_pin_userptr(struct ttm_tt *ttm)
 {
 	struct radeon_device *rdev = radeon_get_rdev(ttm->bdev);
 	struct radeon_ttm_tt *gtt = (void *)ttm;
-	unsigned pinned = 0, nents;
+	unsigned pinned = 0;
 	int r;
 
 	int write = !(gtt->userflags & RADEON_GEM_USERPTR_READONLY);
@@ -521,9 +521,8 @@ static int radeon_ttm_tt_pin_userptr(struct ttm_tt *ttm)
 	if (r)
 		goto release_sg;
 
-	r = -ENOMEM;
-	nents = dma_map_sg(rdev->dev, ttm->sg->sgl, ttm->sg->nents, direction);
-	if (nents == 0)
+	r = dma_map_sgtable(rdev->dev, ttm->sg, direction, 0);
+	if (r)
 		goto release_sg;
 
 	drm_prime_sg_to_page_addr_arrays(ttm->sg, ttm->pages,
@@ -554,9 +553,9 @@ static void radeon_ttm_tt_unpin_userptr(struct ttm_tt *ttm)
 		return;
 
 	/* free the sg table and pages again */
-	dma_unmap_sg(rdev->dev, ttm->sg->sgl, ttm->sg->nents, direction);
+	dma_unmap_sgtable(rdev->dev, ttm->sg, direction, 0);
 
-	for_each_sg_page(ttm->sg->sgl, &sg_iter, ttm->sg->nents, 0) {
+	for_each_sgtable_page(ttm->sg, &sg_iter, 0) {
 		struct page *page = sg_page_iter_page(&sg_iter);
 		if (!(gtt->userflags & RADEON_GEM_USERPTR_READONLY))
 			set_page_dirty(page);
-- 
2.17.1

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[PATCH v6 18/36] drm: rockchip: use common helper for a scatterlist contiguity check

[Marek Szyprowski]

Use common helper for checking the contiguity of the imported dma-buf.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/gpu/drm/rockchip/rockchip_drm_gem.c | 19 +------------------
 1 file changed, 1 insertion(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
index b9275ba7c5a5..2970e534e2bb 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
@@ -460,23 +460,6 @@ struct sg_table *rockchip_gem_prime_get_sg_table(struct drm_gem_object *obj)
 	return sgt;
 }
 
-static unsigned long rockchip_sg_get_contiguous_size(struct sg_table *sgt,
-						     int count)
-{
-	struct scatterlist *s;
-	dma_addr_t expected = sg_dma_address(sgt->sgl);
-	unsigned int i;
-	unsigned long size = 0;
-
-	for_each_sg(sgt->sgl, s, count, i) {
-		if (sg_dma_address(s) != expected)
-			break;
-		expected = sg_dma_address(s) + sg_dma_len(s);
-		size += sg_dma_len(s);
-	}
-	return size;
-}
-
 static int
 rockchip_gem_iommu_map_sg(struct drm_device *drm,
 			  struct dma_buf_attachment *attach,
@@ -498,7 +481,7 @@ rockchip_gem_dma_map_sg(struct drm_device *drm,
 	if (!count)
 		return -EINVAL;
 
-	if (rockchip_sg_get_contiguous_size(sg, count) < attach->dmabuf->size) {
+	if (drm_prime_get_contiguous_size(sg) < attach->dmabuf->size) {
 		DRM_ERROR("failed to map sg_table to contiguous linear address.\n");
 		dma_unmap_sg(drm->dev, sg->sgl, sg->nents,
 			     DMA_BIDIRECTIONAL);
-- 
2.17.1

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[PATCH v6 19/36] drm: rockchip: fix common struct sg_table related issues

[Marek Szyprowski]

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/gpu/drm/rockchip/rockchip_drm_gem.c | 23 +++++++++------------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
index 2970e534e2bb..cb50f2ba2e46 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
@@ -36,8 +36,8 @@ static int rockchip_gem_iommu_map(struct rockchip_gem_object *rk_obj)
 
 	rk_obj->dma_addr = rk_obj->mm.start;
 
-	ret = iommu_map_sg(private->domain, rk_obj->dma_addr, rk_obj->sgt->sgl,
-			   rk_obj->sgt->nents, prot);
+	ret = iommu_map_sgtable(private->domain, rk_obj->dma_addr, rk_obj->sgt,
+				prot);
 	if (ret < rk_obj->base.size) {
 		DRM_ERROR("failed to map buffer: size=%zd request_size=%zd\n",
 			  ret, rk_obj->base.size);
@@ -98,11 +98,10 @@ static int rockchip_gem_get_pages(struct rockchip_gem_object *rk_obj)
 	 * TODO: Replace this by drm_clflush_sg() once it can be implemented
 	 * without relying on symbols that are not exported.
 	 */
-	for_each_sg(rk_obj->sgt->sgl, s, rk_obj->sgt->nents, i)
+	for_each_sgtable_sg(rk_obj->sgt, s, i)
 		sg_dma_address(s) = sg_phys(s);
 
-	dma_sync_sg_for_device(drm->dev, rk_obj->sgt->sgl, rk_obj->sgt->nents,
-			       DMA_TO_DEVICE);
+	dma_sync_sgtable_for_device(drm->dev, rk_obj->sgt, DMA_TO_DEVICE);
 
 	return 0;
 
@@ -350,8 +349,8 @@ void rockchip_gem_free_object(struct drm_gem_object *obj)
 		if (private->domain) {
 			rockchip_gem_iommu_unmap(rk_obj);
 		} else {
-			dma_unmap_sg(drm->dev, rk_obj->sgt->sgl,
-				     rk_obj->sgt->nents, DMA_BIDIRECTIONAL);
+			dma_unmap_sgtable(drm->dev, rk_obj->sgt,
+					  DMA_BIDIRECTIONAL, 0);
 		}
 		drm_prime_gem_destroy(obj, rk_obj->sgt);
 	} else {
@@ -476,15 +475,13 @@ rockchip_gem_dma_map_sg(struct drm_device *drm,
 			struct sg_table *sg,
 			struct rockchip_gem_object *rk_obj)
 {
-	int count = dma_map_sg(drm->dev, sg->sgl, sg->nents,
-			       DMA_BIDIRECTIONAL);
-	if (!count)
-		return -EINVAL;
+	int err = dma_map_sgtable(drm->dev, sg, DMA_BIDIRECTIONAL, 0);
+	if (err)
+		return err;
 
 	if (drm_prime_get_contiguous_size(sg) < attach->dmabuf->size) {
 		DRM_ERROR("failed to map sg_table to contiguous linear address.\n");
-		dma_unmap_sg(drm->dev, sg->sgl, sg->nents,
-			     DMA_BIDIRECTIONAL);
+		dma_unmap_sgtable(drm->dev, sg, DMA_BIDIRECTIONAL, 0);
 		return -EINVAL;
 	}
 
-- 
2.17.1

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[PATCH v6 20/36] drm: tegra: fix common struct sg_table related issues

[Marek Szyprowski]

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/gpu/drm/tegra/gem.c   | 27 ++++++++++-----------------
 drivers/gpu/drm/tegra/plane.c | 15 +++++----------
 2 files changed, 15 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/tegra/gem.c b/drivers/gpu/drm/tegra/gem.c
index 723df142a981..01d94befab11 100644
--- a/drivers/gpu/drm/tegra/gem.c
+++ b/drivers/gpu/drm/tegra/gem.c
@@ -98,8 +98,8 @@ static struct sg_table *tegra_bo_pin(struct device *dev, struct host1x_bo *bo,
 		 * the SG table needs to be copied to avoid overwriting any
 		 * other potential users of the original SG table.
 		 */
-		err = sg_alloc_table_from_sg(sgt, obj->sgt->sgl, obj->sgt->nents,
-					     GFP_KERNEL);
+		err = sg_alloc_table_from_sg(sgt, obj->sgt->sgl,
+					     obj->sgt->orig_nents, GFP_KERNEL);
 		if (err < 0)
 			goto free;
 	} else {
@@ -196,8 +196,7 @@ static int tegra_bo_iommu_map(struct tegra_drm *tegra, struct tegra_bo *bo)
 
 	bo->iova = bo->mm->start;
 
-	bo->size = iommu_map_sg(tegra->domain, bo->iova, bo->sgt->sgl,
-				bo->sgt->nents, prot);
+	bo->size = iommu_map_sgtable(tegra->domain, bo->iova, bo->sgt, prot);
 	if (!bo->size) {
 		dev_err(tegra->drm->dev, "failed to map buffer\n");
 		err = -ENOMEM;
@@ -264,8 +263,7 @@ static struct tegra_bo *tegra_bo_alloc_object(struct drm_device *drm,
 static void tegra_bo_free(struct drm_device *drm, struct tegra_bo *bo)
 {
 	if (bo->pages) {
-		dma_unmap_sg(drm->dev, bo->sgt->sgl, bo->sgt->nents,
-			     DMA_FROM_DEVICE);
+		dma_unmap_sgtable(drm->dev, bo->sgt, DMA_FROM_DEVICE, 0);
 		drm_gem_put_pages(&bo->gem, bo->pages, true, true);
 		sg_free_table(bo->sgt);
 		kfree(bo->sgt);
@@ -290,12 +288,9 @@ static int tegra_bo_get_pages(struct drm_device *drm, struct tegra_bo *bo)
 		goto put_pages;
 	}
 
-	err = dma_map_sg(drm->dev, bo->sgt->sgl, bo->sgt->nents,
-			 DMA_FROM_DEVICE);
-	if (err == 0) {
-		err = -EFAULT;
+	err = dma_map_sgtable(drm->dev, bo->sgt, DMA_FROM_DEVICE, 0);
+	if (err)
 		goto free_sgt;
-	}
 
 	return 0;
 
@@ -571,7 +566,7 @@ tegra_gem_prime_map_dma_buf(struct dma_buf_attachment *attach,
 			goto free;
 	}
 
-	if (dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir) == 0)
+	if (dma_map_sgtable(attach->dev, sgt, dir, 0))
 		goto free;
 
 	return sgt;
@@ -590,7 +585,7 @@ static void tegra_gem_prime_unmap_dma_buf(struct dma_buf_attachment *attach,
 	struct tegra_bo *bo = to_tegra_bo(gem);
 
 	if (bo->pages)
-		dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir);
+		dma_unmap_sgtable(attach->dev, sgt, dir, 0);
 
 	sg_free_table(sgt);
 	kfree(sgt);
@@ -609,8 +604,7 @@ static int tegra_gem_prime_begin_cpu_access(struct dma_buf *buf,
 	struct drm_device *drm = gem->dev;
 
 	if (bo->pages)
-		dma_sync_sg_for_cpu(drm->dev, bo->sgt->sgl, bo->sgt->nents,
-				    DMA_FROM_DEVICE);
+		dma_sync_sgtable_for_cpu(drm->dev, bo->sgt, DMA_FROM_DEVICE);
 
 	return 0;
 }
@@ -623,8 +617,7 @@ static int tegra_gem_prime_end_cpu_access(struct dma_buf *buf,
 	struct drm_device *drm = gem->dev;
 
 	if (bo->pages)
-		dma_sync_sg_for_device(drm->dev, bo->sgt->sgl, bo->sgt->nents,
-				       DMA_TO_DEVICE);
+		dma_sync_sgtable_for_device(drm->dev, bo->sgt, DMA_TO_DEVICE);
 
 	return 0;
 }
diff --git a/drivers/gpu/drm/tegra/plane.c b/drivers/gpu/drm/tegra/plane.c
index 9ccfb56e9b01..0d2ef1662a39 100644
--- a/drivers/gpu/drm/tegra/plane.c
+++ b/drivers/gpu/drm/tegra/plane.c
@@ -130,12 +130,9 @@ static int tegra_dc_pin(struct tegra_dc *dc, struct tegra_plane_state *state)
 		}
 
 		if (sgt) {
-			err = dma_map_sg(dc->dev, sgt->sgl, sgt->nents,
-					 DMA_TO_DEVICE);
-			if (err == 0) {
-				err = -ENOMEM;
+			err = dma_map_sgtable(dc->dev, sgt, DMA_TO_DEVICE, 0);
+			if (err)
 				goto unpin;
-			}
 
 			/*
 			 * The display controller needs contiguous memory, so
@@ -143,7 +140,7 @@ static int tegra_dc_pin(struct tegra_dc *dc, struct tegra_plane_state *state)
 			 * map its SG table to a single contiguous chunk of
 			 * I/O virtual memory.
 			 */
-			if (err > 1) {
+			if (sgt->nents > 1) {
 				err = -EINVAL;
 				goto unpin;
 			}
@@ -165,8 +162,7 @@ static int tegra_dc_pin(struct tegra_dc *dc, struct tegra_plane_state *state)
 		struct sg_table *sgt = state->sgt[i];
 
 		if (sgt)
-			dma_unmap_sg(dc->dev, sgt->sgl, sgt->nents,
-				     DMA_TO_DEVICE);
+			dma_unmap_sgtable(dc->dev, sgt, DMA_TO_DEVICE, 0);
 
 		host1x_bo_unpin(dc->dev, &bo->base, sgt);
 		state->iova[i] = DMA_MAPPING_ERROR;
@@ -185,8 +181,7 @@ static void tegra_dc_unpin(struct tegra_dc *dc, struct tegra_plane_state *state)
 		struct sg_table *sgt = state->sgt[i];
 
 		if (sgt)
-			dma_unmap_sg(dc->dev, sgt->sgl, sgt->nents,
-				     DMA_TO_DEVICE);
+			dma_unmap_sgtable(dc->dev, sgt, DMA_TO_DEVICE, 0);
 
 		host1x_bo_unpin(dc->dev, &bo->base, sgt);
 		state->iova[i] = DMA_MAPPING_ERROR;
-- 
2.17.1

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[PATCH v6 21/36] drm: v3d: fix common struct sg_table related issues

[Marek Szyprowski]

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
---
 drivers/gpu/drm/v3d/v3d_mmu.c | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/v3d/v3d_mmu.c b/drivers/gpu/drm/v3d/v3d_mmu.c
index 3b81ea28c0bb..175c2578ad73 100644
--- a/drivers/gpu/drm/v3d/v3d_mmu.c
+++ b/drivers/gpu/drm/v3d/v3d_mmu.c
@@ -90,19 +90,16 @@ void v3d_mmu_insert_ptes(struct v3d_bo *bo)
 	struct v3d_dev *v3d = to_v3d_dev(shmem_obj->base.dev);
 	u32 page = bo->node.start;
 	u32 page_prot = V3D_PTE_WRITEABLE | V3D_PTE_VALID;
-	unsigned int count;
-	struct scatterlist *sgl;
+	struct sg_dma_page_iter dma_iter;
 
-	for_each_sg(shmem_obj->sgt->sgl, sgl, shmem_obj->sgt->nents, count) {
-		u32 page_address = sg_dma_address(sgl) >> V3D_MMU_PAGE_SHIFT;
+	for_each_sgtable_dma_page(shmem_obj->sgt, &dma_iter, 0) {
+		dma_addr_t dma_addr = sg_page_iter_dma_address(&dma_iter);
+		u32 page_address = dma_addr >> V3D_MMU_PAGE_SHIFT;
 		u32 pte = page_prot | page_address;
-		u32 i;
 
-		BUG_ON(page_address + (sg_dma_len(sgl) >> V3D_MMU_PAGE_SHIFT) >=
-		       BIT(24));
-
-		for (i = 0; i < sg_dma_len(sgl) >> V3D_MMU_PAGE_SHIFT; i++)
-			v3d->pt[page++] = pte + i;
+		BUILD_BUG_ON(V3D_MMU_PAGE_SHIFT != PAGE_SIZE);
+		BUG_ON(page_address + 1 >= BIT(24));
+		v3d->pt[page++] = pte;
 	}
 
 	WARN_ON_ONCE(page - bo->node.start !=
-- 
2.17.1

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Re: [PATCH v6 21/36] drm: v3d: fix common struct sg_table related issues

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 3716 bytes --]

Hi Marek,

I love your patch! Perhaps something to improve:

[auto build test WARNING on next-20200618]
[also build test WARNING on v5.8-rc1]
[cannot apply to linuxtv-media/master staging/staging-testing drm-exynos/exynos-drm-next drm-intel/for-linux-next linus/master v5.8-rc1 v5.7 v5.7-rc7]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use  as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Marek-Szyprowski/DRM-fix-struct-sg_table-nents-vs-orig_nents-misuse/20200619-000417
base:    ce2cc8efd7a40cbd17841add878cb691d0ce0bba
config: alpha-allyesconfig (attached as .config)
compiler: alpha-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=alpha 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>, old ones prefixed by <<):

In file included from include/linux/kernel.h:11,
from include/linux/delay.h:22,
from drivers/gpu/drm/v3d/v3d_drv.h:4,
from drivers/gpu/drm/v3d/v3d_mmu.c:21:
drivers/gpu/drm/v3d/v3d_mmu.c: In function 'v3d_mmu_insert_ptes':
include/linux/compiler.h:339:38: error: call to '__compiletime_assert_254' declared with attribute error: BUILD_BUG_ON failed: V3D_MMU_PAGE_SHIFT != PAGE_SIZE
339 |  _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
|                                      ^
include/linux/compiler.h:320:4: note: in definition of macro '__compiletime_assert'
320 |    prefix ## suffix();             |    ^~~~~~
include/linux/compiler.h:339:2: note: in expansion of macro '_compiletime_assert'
339 |  _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
|  ^~~~~~~~~~~~~~~~~~~
include/linux/build_bug.h:39:37: note: in expansion of macro 'compiletime_assert'
39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
|                                     ^~~~~~~~~~~~~~~~~~
include/linux/build_bug.h:50:2: note: in expansion of macro 'BUILD_BUG_ON_MSG'
50 |  BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
|  ^~~~~~~~~~~~~~~~
>> drivers/gpu/drm/v3d/v3d_mmu.c:100:3: note: in expansion of macro 'BUILD_BUG_ON'
100 |   BUILD_BUG_ON(V3D_MMU_PAGE_SHIFT != PAGE_SIZE);
|   ^~~~~~~~~~~~

vim +/BUILD_BUG_ON +100 drivers/gpu/drm/v3d/v3d_mmu.c

    86	
    87	void v3d_mmu_insert_ptes(struct v3d_bo *bo)
    88	{
    89		struct drm_gem_shmem_object *shmem_obj = &bo->base;
    90		struct v3d_dev *v3d = to_v3d_dev(shmem_obj->base.dev);
    91		u32 page = bo->node.start;
    92		u32 page_prot = V3D_PTE_WRITEABLE | V3D_PTE_VALID;
    93		struct sg_dma_page_iter dma_iter;
    94	
    95		for_each_sgtable_dma_page(shmem_obj->sgt, &dma_iter, 0) {
    96			dma_addr_t dma_addr = sg_page_iter_dma_address(&dma_iter);
    97			u32 page_address = dma_addr >> V3D_MMU_PAGE_SHIFT;
    98			u32 pte = page_prot | page_address;
    99	
 > 100			BUILD_BUG_ON(V3D_MMU_PAGE_SHIFT != PAGE_SIZE);
   101			BUG_ON(page_address + 1 >= BIT(24));
   102			v3d->pt[page++] = pte;
   103		}
   104	
   105		WARN_ON_ONCE(page - bo->node.start !=
   106			     shmem_obj->base.size >> V3D_MMU_PAGE_SHIFT);
   107	
   108		if (v3d_mmu_flush_all(v3d))
   109			dev_err(v3d->drm.dev, "MMU flush timeout\n");
   110	}
   111	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 65125 bytes --]

[-- Attachment #3: Type: text/plain, Size: 156 bytes --]

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[PATCH v6 22/36] drm: virtio: fix common struct sg_table related issues

[Marek Szyprowski]

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
---
 drivers/gpu/drm/virtio/virtgpu_object.c | 36 ++++++++++++++-----------
 drivers/gpu/drm/virtio/virtgpu_vq.c     | 12 ++++-----
 2 files changed, 26 insertions(+), 22 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c b/drivers/gpu/drm/virtio/virtgpu_object.c
index 346cef5ce251..c3b9e3cf786e 100644
--- a/drivers/gpu/drm/virtio/virtgpu_object.c
+++ b/drivers/gpu/drm/virtio/virtgpu_object.c
@@ -72,9 +72,8 @@ void virtio_gpu_cleanup_object(struct virtio_gpu_object *bo)
 
 		if (shmem->pages) {
 			if (shmem->mapped) {
-				dma_unmap_sg(vgdev->vdev->dev.parent,
-					     shmem->pages->sgl, shmem->mapped,
-					     DMA_TO_DEVICE);
+				dma_unmap_sgtable(vgdev->vdev->dev.parent,
+					     shmem->pages, DMA_TO_DEVICE, 0);
 				shmem->mapped = 0;
 			}
 
@@ -157,13 +156,13 @@ static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev,
 	}
 
 	if (use_dma_api) {
-		shmem->mapped = dma_map_sg(vgdev->vdev->dev.parent,
-					   shmem->pages->sgl,
-					   shmem->pages->nents,
-					   DMA_TO_DEVICE);
-		*nents = shmem->mapped;
+		ret = dma_map_sgtable(vgdev->vdev->dev.parent,
+				      shmem->pages, DMA_TO_DEVICE, 0);
+		if (ret)
+			return ret;
+		*nents = shmem->mapped = shmem->pages->nents;
 	} else {
-		*nents = shmem->pages->nents;
+		*nents = shmem->pages->orig_nents;
 	}
 
 	*ents = kmalloc_array(*nents, sizeof(struct virtio_gpu_mem_entry),
@@ -173,13 +172,20 @@ static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev,
 		return -ENOMEM;
 	}
 
-	for_each_sg(shmem->pages->sgl, sg, *nents, si) {
-		(*ents)[si].addr = cpu_to_le64(use_dma_api
-					       ? sg_dma_address(sg)
-					       : sg_phys(sg));
-		(*ents)[si].length = cpu_to_le32(sg->length);
-		(*ents)[si].padding = 0;
+	if (use_dma_api) {
+		for_each_sgtable_dma_sg(shmem->pages, sg, si) {
+			(*ents)[si].addr = cpu_to_le64(sg_dma_address(sg));
+			(*ents)[si].length = cpu_to_le32(sg_dma_len(sg));
+			(*ents)[si].padding = 0;
+		}
+	} else {
+		for_each_sgtable_sg(shmem->pages, sg, si) {
+			(*ents)[si].addr = cpu_to_le64(sg_phys(sg));
+			(*ents)[si].length = cpu_to_le32(sg->length);
+			(*ents)[si].padding = 0;
+		}
 	}
+
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c
index 9e663a5d9952..e5765db85c20 100644
--- a/drivers/gpu/drm/virtio/virtgpu_vq.c
+++ b/drivers/gpu/drm/virtio/virtgpu_vq.c
@@ -302,7 +302,7 @@ static struct sg_table *vmalloc_to_sgt(char *data, uint32_t size, int *sg_ents)
 		return NULL;
 	}
 
-	for_each_sg(sgt->sgl, sg, *sg_ents, i) {
+	for_each_sgtable_sg(sgt, sg, i) {
 		pg = vmalloc_to_page(data);
 		if (!pg) {
 			sg_free_table(sgt);
@@ -603,9 +603,8 @@ void virtio_gpu_cmd_transfer_to_host_2d(struct virtio_gpu_device *vgdev,
 	struct virtio_gpu_object_shmem *shmem = to_virtio_gpu_shmem(bo);
 
 	if (use_dma_api)
-		dma_sync_sg_for_device(vgdev->vdev->dev.parent,
-				       shmem->pages->sgl, shmem->pages->nents,
-				       DMA_TO_DEVICE);
+		dma_sync_sgtable_for_device(vgdev->vdev->dev.parent,
+					    shmem->pages, DMA_TO_DEVICE);
 
 	cmd_p = virtio_gpu_alloc_cmd(vgdev, &vbuf, sizeof(*cmd_p));
 	memset(cmd_p, 0, sizeof(*cmd_p));
@@ -1019,9 +1018,8 @@ void virtio_gpu_cmd_transfer_to_host_3d(struct virtio_gpu_device *vgdev,
 	struct virtio_gpu_object_shmem *shmem = to_virtio_gpu_shmem(bo);
 
 	if (use_dma_api)
-		dma_sync_sg_for_device(vgdev->vdev->dev.parent,
-				       shmem->pages->sgl, shmem->pages->nents,
-				       DMA_TO_DEVICE);
+		dma_sync_sgtable_for_device(vgdev->vdev->dev.parent,
+					    shmem->pages, DMA_TO_DEVICE);
 
 	cmd_p = virtio_gpu_alloc_cmd(vgdev, &vbuf, sizeof(*cmd_p));
 	memset(cmd_p, 0, sizeof(*cmd_p));
-- 
2.17.1

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[PATCH v6 23/36] drm: vmwgfx: fix common struct sg_table related issues

[Marek Szyprowski]

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Roland Scheidegger <sroland@vmware.com>
---
 drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c | 17 ++++-------------
 1 file changed, 4 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c
index bf0bc4697959..49ed6add6969 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c
@@ -362,8 +362,7 @@ static void vmw_ttm_unmap_from_dma(struct vmw_ttm_tt *vmw_tt)
 {
 	struct device *dev = vmw_tt->dev_priv->dev->dev;
 
-	dma_unmap_sg(dev, vmw_tt->sgt.sgl, vmw_tt->sgt.nents,
-		DMA_BIDIRECTIONAL);
+	dma_unmap_sgtable(dev, vmw_tt->sgt, DMA_BIDIRECTIONAL, 0);
 	vmw_tt->sgt.nents = vmw_tt->sgt.orig_nents;
 }
 
@@ -383,16 +382,8 @@ static void vmw_ttm_unmap_from_dma(struct vmw_ttm_tt *vmw_tt)
 static int vmw_ttm_map_for_dma(struct vmw_ttm_tt *vmw_tt)
 {
 	struct device *dev = vmw_tt->dev_priv->dev->dev;
-	int ret;
-
-	ret = dma_map_sg(dev, vmw_tt->sgt.sgl, vmw_tt->sgt.orig_nents,
-			 DMA_BIDIRECTIONAL);
-	if (unlikely(ret == 0))
-		return -ENOMEM;
 
-	vmw_tt->sgt.nents = ret;
-
-	return 0;
+	return dma_map_sgtable(dev, vmw_tt->sgt, DMA_BIDIRECTIONAL, 0);
 }
 
 /**
@@ -449,10 +440,10 @@ static int vmw_ttm_map_dma(struct vmw_ttm_tt *vmw_tt)
 		if (unlikely(ret != 0))
 			goto out_sg_alloc_fail;
 
-		if (vsgt->num_pages > vmw_tt->sgt.nents) {
+		if (vsgt->num_pages > vmw_tt->sgt.orig_nents) {
 			uint64_t over_alloc =
 				sgl_size * (vsgt->num_pages -
-					    vmw_tt->sgt.nents);
+					    vmw_tt->sgt.orig_nents);
 
 			ttm_mem_global_free(glob, over_alloc);
 			vmw_tt->sg_alloc_size -= over_alloc;
-- 
2.17.1

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Re: [PATCH v6 23/36] drm: vmwgfx: fix common struct sg_table related issues

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 2635 bytes --]

Hi Marek,

I love your patch! Perhaps something to improve:

[auto build test WARNING on next-20200618]
[also build test WARNING on v5.8-rc1]
[cannot apply to linuxtv-media/master staging/staging-testing drm-exynos/exynos-drm-next drm-intel/for-linux-next linus/master v5.8-rc1 v5.7 v5.7-rc7]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use  as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Marek-Szyprowski/DRM-fix-struct-sg_table-nents-vs-orig_nents-misuse/20200619-000417
base:    ce2cc8efd7a40cbd17841add878cb691d0ce0bba
config: x86_64-randconfig-s021-20200618 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-13) 9.3.0
reproduce:
        # apt-get install sparse
        # sparse version: v0.6.2-rc1-10-gc17b1b06-dirty
        # save the attached .config to linux build tree
        make W=1 C=1 ARCH=x86_64 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__'

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>


sparse warnings: (new ones prefixed by >>)

>> drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c:365:38: sparse: sparse: incorrect type in argument 2 (different base types) @@     expected struct sg_table *sgt @@     got struct sg_table sgt @@
>> drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c:365:38: sparse:     expected struct sg_table *sgt
>> drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c:365:38: sparse:     got struct sg_table sgt
   drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c:386:43: sparse: sparse: incorrect type in argument 2 (different base types) @@     expected struct sg_table *sgt @@     got struct sg_table sgt @@
   drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c:386:43: sparse:     expected struct sg_table *sgt
   drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c:386:43: sparse:     got struct sg_table sgt

vim +365 drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c

   352	
   353	/**
   354	 * vmw_ttm_unmap_from_dma - unmap  device addresses previsouly mapped for
   355	 * TTM pages
   356	 *
   357	 * @vmw_tt: Pointer to a struct vmw_ttm_backend
   358	 *
   359	 * Used to free dma mappings previously mapped by vmw_ttm_map_for_dma.
   360	 */
   361	static void vmw_ttm_unmap_from_dma(struct vmw_ttm_tt *vmw_tt)
   362	{
   363		struct device *dev = vmw_tt->dev_priv->dev->dev;
   364	
 > 365		dma_unmap_sgtable(dev, vmw_tt->sgt, DMA_BIDIRECTIONAL, 0);
   366		vmw_tt->sgt.nents = vmw_tt->sgt.orig_nents;
   367	}
   368	

---
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https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

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Re: [PATCH v6 23/36] drm: vmwgfx: fix common struct sg_table related issues

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 4902 bytes --]

Hi Marek,

I love your patch! Yet something to improve:

[auto build test ERROR on next-20200618]
[also build test ERROR on v5.8-rc1]
[cannot apply to linuxtv-media/master staging/staging-testing drm-exynos/exynos-drm-next drm-intel/for-linux-next linus/master v5.8-rc1 v5.7 v5.7-rc7]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use  as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Marek-Szyprowski/DRM-fix-struct-sg_table-nents-vs-orig_nents-misuse/20200619-000417
base:    ce2cc8efd7a40cbd17841add878cb691d0ce0bba
config: x86_64-rhel-7.6 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-13) 9.3.0
reproduce (this is a W=1 build):
        # save the attached .config to linux build tree
        make W=1 ARCH=x86_64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All error/warnings (new ones prefixed by >>):

   drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c: In function 'vmw_ttm_unmap_from_dma':
>> drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c:365:31: error: incompatible type for argument 2 of 'dma_unmap_sgtable'
     365 |  dma_unmap_sgtable(dev, vmw_tt->sgt, DMA_BIDIRECTIONAL, 0);
         |                         ~~~~~~^~~~~
         |                               |
         |                               struct sg_table
   In file included from include/linux/dma-buf.h:20,
                    from drivers/gpu/drm/vmwgfx/ttm_object.h:40,
                    from drivers/gpu/drm/vmwgfx/ttm_lock.h:55,
                    from drivers/gpu/drm/vmwgfx/vmwgfx_drv.h:44,
                    from drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c:28:
   include/linux/dma-mapping.h:651:75: note: expected 'struct sg_table *' but argument is of type 'struct sg_table'
     651 | static inline void dma_unmap_sgtable(struct device *dev, struct sg_table *sgt,
         |                                                          ~~~~~~~~~~~~~~~~~^~~
   drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c: In function 'vmw_ttm_map_for_dma':
>> drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c:386:36: error: incompatible type for argument 2 of 'dma_map_sgtable'
     386 |  return dma_map_sgtable(dev, vmw_tt->sgt, DMA_BIDIRECTIONAL, 0);
         |                              ~~~~~~^~~~~
         |                                    |
         |                                    struct sg_table
   In file included from include/linux/dma-buf.h:20,
                    from drivers/gpu/drm/vmwgfx/ttm_object.h:40,
                    from drivers/gpu/drm/vmwgfx/ttm_lock.h:55,
                    from drivers/gpu/drm/vmwgfx/vmwgfx_drv.h:44,
                    from drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c:28:
   include/linux/dma-mapping.h:628:72: note: expected 'struct sg_table *' but argument is of type 'struct sg_table'
     628 | static inline int dma_map_sgtable(struct device *dev, struct sg_table *sgt,
         |                                                       ~~~~~~~~~~~~~~~~~^~~
>> drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c:387:1: warning: control reaches end of non-void function [-Wreturn-type]
     387 | }
         | ^

vim +/dma_unmap_sgtable +365 drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c

   352	
   353	/**
   354	 * vmw_ttm_unmap_from_dma - unmap  device addresses previsouly mapped for
   355	 * TTM pages
   356	 *
   357	 * @vmw_tt: Pointer to a struct vmw_ttm_backend
   358	 *
   359	 * Used to free dma mappings previously mapped by vmw_ttm_map_for_dma.
   360	 */
   361	static void vmw_ttm_unmap_from_dma(struct vmw_ttm_tt *vmw_tt)
   362	{
   363		struct device *dev = vmw_tt->dev_priv->dev->dev;
   364	
 > 365		dma_unmap_sgtable(dev, vmw_tt->sgt, DMA_BIDIRECTIONAL, 0);
   366		vmw_tt->sgt.nents = vmw_tt->sgt.orig_nents;
   367	}
   368	
   369	/**
   370	 * vmw_ttm_map_for_dma - map TTM pages to get device addresses
   371	 *
   372	 * @vmw_tt: Pointer to a struct vmw_ttm_backend
   373	 *
   374	 * This function is used to get device addresses from the kernel DMA layer.
   375	 * However, it's violating the DMA API in that when this operation has been
   376	 * performed, it's illegal for the CPU to write to the pages without first
   377	 * unmapping the DMA mappings, or calling dma_sync_sg_for_cpu(). It is
   378	 * therefore only legal to call this function if we know that the function
   379	 * dma_sync_sg_for_cpu() is a NOP, and dma_sync_sg_for_device() is at most
   380	 * a CPU write buffer flush.
   381	 */
   382	static int vmw_ttm_map_for_dma(struct vmw_ttm_tt *vmw_tt)
   383	{
   384		struct device *dev = vmw_tt->dev_priv->dev->dev;
   385	
 > 386		return dma_map_sgtable(dev, vmw_tt->sgt, DMA_BIDIRECTIONAL, 0);
 > 387	}
   388	

---
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https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

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[PATCH v6 24/36] xen: gntdev: fix common struct sg_table related issues

[Marek Szyprowski]

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Juergen Gross <jgross@suse.com> 
---
 drivers/xen/gntdev-dmabuf.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/xen/gntdev-dmabuf.c b/drivers/xen/gntdev-dmabuf.c
index 75d3bb948bf3..ba6cad871568 100644
--- a/drivers/xen/gntdev-dmabuf.c
+++ b/drivers/xen/gntdev-dmabuf.c
@@ -247,10 +247,9 @@ static void dmabuf_exp_ops_detach(struct dma_buf *dma_buf,
 
 		if (sgt) {
 			if (gntdev_dmabuf_attach->dir != DMA_NONE)
-				dma_unmap_sg_attrs(attach->dev, sgt->sgl,
-						   sgt->nents,
-						   gntdev_dmabuf_attach->dir,
-						   DMA_ATTR_SKIP_CPU_SYNC);
+				dma_unmap_sgtable(attach->dev, sgt,
+						  gntdev_dmabuf_attach->dir,
+						  DMA_ATTR_SKIP_CPU_SYNC);
 			sg_free_table(sgt);
 		}
 
@@ -288,8 +287,8 @@ dmabuf_exp_ops_map_dma_buf(struct dma_buf_attachment *attach,
 	sgt = dmabuf_pages_to_sgt(gntdev_dmabuf->pages,
 				  gntdev_dmabuf->nr_pages);
 	if (!IS_ERR(sgt)) {
-		if (!dma_map_sg_attrs(attach->dev, sgt->sgl, sgt->nents, dir,
-				      DMA_ATTR_SKIP_CPU_SYNC)) {
+		if (dma_map_sgtable(attach->dev, sgt, dir,
+				    DMA_ATTR_SKIP_CPU_SYNC)) {
 			sg_free_table(sgt);
 			kfree(sgt);
 			sgt = ERR_PTR(-ENOMEM);
@@ -625,7 +624,7 @@ dmabuf_imp_to_refs(struct gntdev_dmabuf_priv *priv, struct device *dev,
 
 	/* Now convert sgt to array of pages and check for page validity. */
 	i = 0;
-	for_each_sg_page(sgt->sgl, &sg_iter, sgt->nents, 0) {
+	for_each_sgtable_page(sgt, &sg_iter, 0) {
 		struct page *page = sg_page_iter_page(&sg_iter);
 		/*
 		 * Check if page is valid: this can happen if we are given
-- 
2.17.1

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[PATCH v6 25/36] drm: host1x: fix common struct sg_table related issues

[Marek Szyprowski]

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/gpu/host1x/job.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/host1x/job.c b/drivers/gpu/host1x/job.c
index a10643aa89aa..4832b57f10c4 100644
--- a/drivers/gpu/host1x/job.c
+++ b/drivers/gpu/host1x/job.c
@@ -166,11 +166,9 @@ static unsigned int pin_job(struct host1x *host, struct host1x_job *job)
 				goto unpin;
 			}
 
-			err = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
-			if (!err) {
-				err = -ENOMEM;
+			err = dma_map_sgtable(dev, sgt, dir, 0);
+			if (err)
 				goto unpin;
-			}
 
 			job->unpins[job->num_unpins].dev = dev;
 			job->unpins[job->num_unpins].dir = dir;
@@ -217,7 +215,7 @@ static unsigned int pin_job(struct host1x *host, struct host1x_job *job)
 		}
 
 		if (!IS_ENABLED(CONFIG_TEGRA_HOST1X_FIREWALL) && host->domain) {
-			for_each_sg(sgt->sgl, sg, sgt->nents, j)
+			for_each_sgtable_sg(sgt, sg, j)
 				gather_size += sg->length;
 			gather_size = iova_align(&host->iova, gather_size);
 
@@ -229,9 +227,9 @@ static unsigned int pin_job(struct host1x *host, struct host1x_job *job)
 				goto unpin;
 			}
 
-			err = iommu_map_sg(host->domain,
+			err = iommu_map_sgtable(host->domain,
 					iova_dma_addr(&host->iova, alloc),
-					sgt->sgl, sgt->nents, IOMMU_READ);
+					sgt, IOMMU_READ);
 			if (err == 0) {
 				__free_iova(&host->iova, alloc);
 				err = -EINVAL;
@@ -241,12 +239,9 @@ static unsigned int pin_job(struct host1x *host, struct host1x_job *job)
 			job->unpins[job->num_unpins].size = gather_size;
 			phys_addr = iova_dma_addr(&host->iova, alloc);
 		} else if (sgt) {
-			err = dma_map_sg(host->dev, sgt->sgl, sgt->nents,
-					 DMA_TO_DEVICE);
-			if (!err) {
-				err = -ENOMEM;
+			err = dma_map_sgtable(host->dev, sgt, DMA_TO_DEVICE, 0);
+			if (err)
 				goto unpin;
-			}
 
 			job->unpins[job->num_unpins].dir = DMA_TO_DEVICE;
 			job->unpins[job->num_unpins].dev = host->dev;
@@ -647,8 +642,7 @@ void host1x_job_unpin(struct host1x_job *job)
 		}
 
 		if (unpin->dev && sgt)
-			dma_unmap_sg(unpin->dev, sgt->sgl, sgt->nents,
-				     unpin->dir);
+			dma_unmap_sgtable(unpin->dev, sgt, unpin->dir, 0);
 
 		host1x_bo_unpin(dev, unpin->bo, sgt);
 		host1x_bo_put(unpin->bo);
-- 
2.17.1

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[PATCH v6 26/36] drm: rcar-du: fix common struct sg_table related issues

[Marek Szyprowski]

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

dma_map_sgtable() function returns zero or an error code, so adjust the
return value check for the vsp1_du_map_sg() function.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/gpu/drm/rcar-du/rcar_du_vsp.c  | 3 +--
 drivers/media/platform/vsp1/vsp1_drm.c | 8 ++++----
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_vsp.c b/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
index f1a81c9b184d..a27bff999649 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
@@ -197,9 +197,8 @@ int rcar_du_vsp_map_fb(struct rcar_du_vsp *vsp, struct drm_framebuffer *fb,
 			goto fail;
 
 		ret = vsp1_du_map_sg(vsp->vsp, sgt);
-		if (!ret) {
+		if (ret) {
 			sg_free_table(sgt);
-			ret = -ENOMEM;
 			goto fail;
 		}
 	}
diff --git a/drivers/media/platform/vsp1/vsp1_drm.c b/drivers/media/platform/vsp1/vsp1_drm.c
index a4a45d68a6ef..86d5e3f4b1ff 100644
--- a/drivers/media/platform/vsp1/vsp1_drm.c
+++ b/drivers/media/platform/vsp1/vsp1_drm.c
@@ -912,8 +912,8 @@ int vsp1_du_map_sg(struct device *dev, struct sg_table *sgt)
 	 * skip cache sync. This will need to be revisited when support for
 	 * non-coherent buffers will be added to the DU driver.
 	 */
-	return dma_map_sg_attrs(vsp1->bus_master, sgt->sgl, sgt->nents,
-				DMA_TO_DEVICE, DMA_ATTR_SKIP_CPU_SYNC);
+	return dma_map_sgtable(vsp1->bus_master, sgt, DMA_TO_DEVICE,
+			       DMA_ATTR_SKIP_CPU_SYNC);
 }
 EXPORT_SYMBOL_GPL(vsp1_du_map_sg);
 
@@ -921,8 +921,8 @@ void vsp1_du_unmap_sg(struct device *dev, struct sg_table *sgt)
 {
 	struct vsp1_device *vsp1 = dev_get_drvdata(dev);
 
-	dma_unmap_sg_attrs(vsp1->bus_master, sgt->sgl, sgt->nents,
-			   DMA_TO_DEVICE, DMA_ATTR_SKIP_CPU_SYNC);
+	dma_unmap_sgtable(vsp1->bus_master, sgt, DMA_TO_DEVICE,
+			  DMA_ATTR_SKIP_CPU_SYNC);
 }
 EXPORT_SYMBOL_GPL(vsp1_du_unmap_sg);
 
-- 
2.17.1

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[PATCH v6 27/36] dmabuf: fix common struct sg_table related issues

[Marek Szyprowski]

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
---
 drivers/dma-buf/heaps/heap-helpers.c | 13 ++++++-------
 drivers/dma-buf/udmabuf.c            |  7 +++----
 2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/drivers/dma-buf/heaps/heap-helpers.c b/drivers/dma-buf/heaps/heap-helpers.c
index 9f964ca3f59c..d0696cf937af 100644
--- a/drivers/dma-buf/heaps/heap-helpers.c
+++ b/drivers/dma-buf/heaps/heap-helpers.c
@@ -140,13 +140,12 @@ 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;
+	struct sg_table *table = &a->table;
+	int ret;
 
-	if (!dma_map_sg(attachment->dev, table->sgl, table->nents,
-			direction))
-		table = ERR_PTR(-ENOMEM);
+	ret = dma_map_sgtable(attachment->dev, table, direction, 0);
+	if (ret)
+		table = ERR_PTR(ret);
 	return table;
 }
 
@@ -154,7 +153,7 @@ 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);
+	dma_unmap_sgtable(attachment->dev, table, direction, 0);
 }
 
 static vm_fault_t dma_heap_vm_fault(struct vm_fault *vmf)
diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
index acb26c627d27..89e293bd9252 100644
--- a/drivers/dma-buf/udmabuf.c
+++ b/drivers/dma-buf/udmabuf.c
@@ -63,10 +63,9 @@ static struct sg_table *get_sg_table(struct device *dev, struct dma_buf *buf,
 					GFP_KERNEL);
 	if (ret < 0)
 		goto err;
-	if (!dma_map_sg(dev, sg->sgl, sg->nents, direction)) {
-		ret = -EINVAL;
+	ret = dma_map_sgtable(dev, sg, direction, 0);
+	if (ret < 0)
 		goto err;
-	}
 	return sg;
 
 err:
@@ -78,7 +77,7 @@ static struct sg_table *get_sg_table(struct device *dev, struct dma_buf *buf,
 static void put_sg_table(struct device *dev, struct sg_table *sg,
 			 enum dma_data_direction direction)
 {
-	dma_unmap_sg(dev, sg->sgl, sg->nents, direction);
+	dma_unmap_sgtable(dev, sg, direction, 0);
 	sg_free_table(sg);
 	kfree(sg);
 }
-- 
2.17.1

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[PATCH v6 28/36] staging: ion: remove dead code

[Marek Szyprowski]

ion_heap_pages_zero() function is not used at all, so remove it to
simplify the ion_heap_sglist_zero() function later.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/staging/android/ion/ion.h      | 1 -
 drivers/staging/android/ion/ion_heap.c | 9 ---------
 2 files changed, 10 deletions(-)

diff --git a/drivers/staging/android/ion/ion.h b/drivers/staging/android/ion/ion.h
index 74914a266e25..c199e88afc6c 100644
--- a/drivers/staging/android/ion/ion.h
+++ b/drivers/staging/android/ion/ion.h
@@ -177,7 +177,6 @@ void ion_heap_unmap_kernel(struct ion_heap *heap, struct ion_buffer *buffer);
 int ion_heap_map_user(struct ion_heap *heap, struct ion_buffer *buffer,
 		      struct vm_area_struct *vma);
 int ion_heap_buffer_zero(struct ion_buffer *buffer);
-int ion_heap_pages_zero(struct page *page, size_t size, pgprot_t pgprot);
 
 /**
  * ion_heap_init_shrinker
diff --git a/drivers/staging/android/ion/ion_heap.c b/drivers/staging/android/ion/ion_heap.c
index 0755b11348ed..9c23b2382a1e 100644
--- a/drivers/staging/android/ion/ion_heap.c
+++ b/drivers/staging/android/ion/ion_heap.c
@@ -145,15 +145,6 @@ int ion_heap_buffer_zero(struct ion_buffer *buffer)
 	return ion_heap_sglist_zero(table->sgl, table->nents, pgprot);
 }
 
-int ion_heap_pages_zero(struct page *page, size_t size, pgprot_t pgprot)
-{
-	struct scatterlist sg;
-
-	sg_init_table(&sg, 1);
-	sg_set_page(&sg, page, size, 0);
-	return ion_heap_sglist_zero(&sg, 1, pgprot);
-}
-
 void ion_heap_freelist_add(struct ion_heap *heap, struct ion_buffer *buffer)
 {
 	spin_lock(&heap->free_lock);
-- 
2.17.1

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[PATCH v6 29/36] staging: ion: fix common struct sg_table related issues

[Marek Szyprowski]

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/staging/android/ion/ion.c             | 25 +++++------
 drivers/staging/android/ion/ion_heap.c        | 44 ++++++-------------
 drivers/staging/android/ion/ion_system_heap.c |  2 +-
 3 files changed, 25 insertions(+), 46 deletions(-)

diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c
index 38b51eace4f9..3c9f09506ffa 100644
--- a/drivers/staging/android/ion/ion.c
+++ b/drivers/staging/android/ion/ion.c
@@ -147,14 +147,14 @@ static struct sg_table *dup_sg_table(struct sg_table *table)
 	if (!new_table)
 		return ERR_PTR(-ENOMEM);
 
-	ret = sg_alloc_table(new_table, table->nents, GFP_KERNEL);
+	ret = sg_alloc_table(new_table, table->orig_nents, GFP_KERNEL);
 	if (ret) {
 		kfree(new_table);
 		return ERR_PTR(-ENOMEM);
 	}
 
 	new_sg = new_table->sgl;
-	for_each_sg(table->sgl, sg, table->nents, i) {
+	for_each_sgtable_sg(table, sg, i) {
 		memcpy(new_sg, sg, sizeof(*sg));
 		new_sg->dma_address = 0;
 		new_sg = sg_next(new_sg);
@@ -224,12 +224,13 @@ static struct sg_table *ion_map_dma_buf(struct dma_buf_attachment *attachment,
 {
 	struct ion_dma_buf_attachment *a = attachment->priv;
 	struct sg_table *table;
+	int ret;
 
 	table = a->table;
 
-	if (!dma_map_sg(attachment->dev, table->sgl, table->nents,
-			direction))
-		return ERR_PTR(-ENOMEM);
+	ret = dma_map_sgtable(attachment->dev, table, direction, 0);
+	if (ret)
+		return ERR_PTR(ret);
 
 	return table;
 }
@@ -238,7 +239,7 @@ static void ion_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);
+	dma_unmap_sgtable(attachment->dev, table, direction, 0);
 }
 
 static int ion_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
@@ -296,10 +297,8 @@ static int ion_dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
 	}
 
 	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);
-	}
+	list_for_each_entry(a, &buffer->attachments, list)
+		dma_sync_sgtable_for_cpu(a->dev, a->table, direction);
 
 unlock:
 	mutex_unlock(&buffer->lock);
@@ -319,10 +318,8 @@ static int ion_dma_buf_end_cpu_access(struct dma_buf *dmabuf,
 	}
 
 	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);
-	}
+	list_for_each_entry(a, &buffer->attachments, list)
+		dma_sync_sgtable_for_device(a->dev, a->table, direction);
 	mutex_unlock(&buffer->lock);
 
 	return 0;
diff --git a/drivers/staging/android/ion/ion_heap.c b/drivers/staging/android/ion/ion_heap.c
index 9c23b2382a1e..79f27949edda 100644
--- a/drivers/staging/android/ion/ion_heap.c
+++ b/drivers/staging/android/ion/ion_heap.c
@@ -20,8 +20,7 @@
 void *ion_heap_map_kernel(struct ion_heap *heap,
 			  struct ion_buffer *buffer)
 {
-	struct scatterlist *sg;
-	int i, j;
+	struct sg_page_iter piter;
 	void *vaddr;
 	pgprot_t pgprot;
 	struct sg_table *table = buffer->sg_table;
@@ -38,14 +37,11 @@ void *ion_heap_map_kernel(struct ion_heap *heap,
 	else
 		pgprot = pgprot_writecombine(PAGE_KERNEL);
 
-	for_each_sg(table->sgl, sg, table->nents, i) {
-		int npages_this_entry = PAGE_ALIGN(sg->length) / PAGE_SIZE;
-		struct page *page = sg_page(sg);
-
-		BUG_ON(i >= npages);
-		for (j = 0; j < npages_this_entry; j++)
-			*(tmp++) = page++;
+	for_each_sgtable_page(table, &piter, 0) {
+		BUG_ON(tmp - pages >= npages);
+		*tmp++ = sg_page_iter_page(&piter);
 	}
+
 	vaddr = vmap(pages, npages, VM_MAP, pgprot);
 	vfree(pages);
 
@@ -64,32 +60,19 @@ void ion_heap_unmap_kernel(struct ion_heap *heap,
 int ion_heap_map_user(struct ion_heap *heap, struct ion_buffer *buffer,
 		      struct vm_area_struct *vma)
 {
+	struct sg_page_iter piter;
 	struct sg_table *table = buffer->sg_table;
 	unsigned long addr = vma->vm_start;
-	unsigned long offset = vma->vm_pgoff * PAGE_SIZE;
-	struct scatterlist *sg;
-	int i;
 	int ret;
 
-	for_each_sg(table->sgl, sg, table->nents, i) {
-		struct page *page = sg_page(sg);
-		unsigned long remainder = vma->vm_end - addr;
-		unsigned long len = sg->length;
+	for_each_sgtable_page(table, &piter, vma->vm_pgoff) {
+		struct page *page = sg_page_iter_page(&piter);
 
-		if (offset >= sg->length) {
-			offset -= sg->length;
-			continue;
-		} else if (offset) {
-			page += offset / PAGE_SIZE;
-			len = sg->length - offset;
-			offset = 0;
-		}
-		len = min(len, remainder);
-		ret = remap_pfn_range(vma, addr, page_to_pfn(page), len,
+		ret = remap_pfn_range(vma, addr, page_to_pfn(page), PAGE_SIZE,
 				      vma->vm_page_prot);
 		if (ret)
 			return ret;
-		addr += len;
+		addr += PAGE_SIZE;
 		if (addr >= vma->vm_end)
 			return 0;
 	}
@@ -109,15 +92,14 @@ static int ion_heap_clear_pages(struct page **pages, int num, pgprot_t pgprot)
 	return 0;
 }
 
-static int ion_heap_sglist_zero(struct scatterlist *sgl, unsigned int nents,
-				pgprot_t pgprot)
+static int ion_heap_sglist_zero(struct sg_table *sgt, pgprot_t pgprot)
 {
 	int p = 0;
 	int ret = 0;
 	struct sg_page_iter piter;
 	struct page *pages[32];
 
-	for_each_sg_page(sgl, &piter, nents, 0) {
+	for_each_sgtable_page(sgt, &piter, 0) {
 		pages[p++] = sg_page_iter_page(&piter);
 		if (p == ARRAY_SIZE(pages)) {
 			ret = ion_heap_clear_pages(pages, p, pgprot);
@@ -142,7 +124,7 @@ int ion_heap_buffer_zero(struct ion_buffer *buffer)
 	else
 		pgprot = pgprot_writecombine(PAGE_KERNEL);
 
-	return ion_heap_sglist_zero(table->sgl, table->nents, pgprot);
+	return ion_heap_sglist_zero(table, pgprot);
 }
 
 void ion_heap_freelist_add(struct ion_heap *heap, struct ion_buffer *buffer)
diff --git a/drivers/staging/android/ion/ion_system_heap.c b/drivers/staging/android/ion/ion_system_heap.c
index b83a1d16bd89..eac0632ab4e8 100644
--- a/drivers/staging/android/ion/ion_system_heap.c
+++ b/drivers/staging/android/ion/ion_system_heap.c
@@ -162,7 +162,7 @@ static void ion_system_heap_free(struct ion_buffer *buffer)
 	if (!(buffer->private_flags & ION_PRIV_FLAG_SHRINKER_FREE))
 		ion_heap_buffer_zero(buffer);
 
-	for_each_sg(table->sgl, sg, table->nents, i)
+	for_each_sgtable_sg(table, sg, i)
 		free_buffer_page(sys_heap, buffer, sg_page(sg));
 	sg_free_table(table);
 	kfree(table);
-- 
2.17.1

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[PATCH v6 30/36] staging: tegra-vde: fix common struct sg_table related issues

[Marek Szyprowski]

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/staging/media/tegra-vde/iommu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/media/tegra-vde/iommu.c b/drivers/staging/media/tegra-vde/iommu.c
index 6af863d92123..adf8dc7ee25c 100644
--- a/drivers/staging/media/tegra-vde/iommu.c
+++ b/drivers/staging/media/tegra-vde/iommu.c
@@ -36,8 +36,8 @@ int tegra_vde_iommu_map(struct tegra_vde *vde,
 
 	addr = iova_dma_addr(&vde->iova, iova);
 
-	size = iommu_map_sg(vde->domain, addr, sgt->sgl, sgt->nents,
-			    IOMMU_READ | IOMMU_WRITE);
+	size = iommu_map_sgtable(vde->domain, addr, sgt,
+				 IOMMU_READ | IOMMU_WRITE);
 	if (!size) {
 		__free_iova(&vde->iova, iova);
 		return -ENXIO;
-- 
2.17.1

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[PATCH v6 31/36] misc: fastrpc: fix common struct sg_table related issues

[Marek Szyprowski]

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/misc/fastrpc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index 7939c55daceb..9d6867749316 100644
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -518,7 +518,7 @@ fastrpc_map_dma_buf(struct dma_buf_attachment *attachment,
 
 	table = &a->sgt;
 
-	if (!dma_map_sg(attachment->dev, table->sgl, table->nents, dir))
+	if (!dma_map_sgtable(attachment->dev, table, dir, 0))
 		return ERR_PTR(-ENOMEM);
 
 	return table;
@@ -528,7 +528,7 @@ static void fastrpc_unmap_dma_buf(struct dma_buf_attachment *attach,
 				  struct sg_table *table,
 				  enum dma_data_direction dir)
 {
-	dma_unmap_sg(attach->dev, table->sgl, table->nents, dir);
+	dma_unmap_sgtable(attach->dev, table, dir, 0);
 }
 
 static void fastrpc_release(struct dma_buf *dmabuf)
-- 
2.17.1

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[PATCH v6 32/36] rapidio: fix common struct sg_table related issues

[Marek Szyprowski]

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/rapidio/devices/rio_mport_cdev.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/rapidio/devices/rio_mport_cdev.c b/drivers/rapidio/devices/rio_mport_cdev.c
index 451608e960a1..a33cc1b6beb2 100644
--- a/drivers/rapidio/devices/rio_mport_cdev.c
+++ b/drivers/rapidio/devices/rio_mport_cdev.c
@@ -573,8 +573,7 @@ static void dma_req_free(struct kref *ref)
 			refcount);
 	struct mport_cdev_priv *priv = req->priv;
 
-	dma_unmap_sg(req->dmach->device->dev,
-		     req->sgt.sgl, req->sgt.nents, req->dir);
+	dma_unmap_sgtable(req->dmach->device->dev, req->sgt, req->dir, 0);
 	sg_free_table(&req->sgt);
 	if (req->page_list) {
 		unpin_user_pages(req->page_list, req->nr_pages);
@@ -930,9 +929,8 @@ rio_dma_transfer(struct file *filp, u32 transfer_mode,
 				xfer->offset, xfer->length);
 	}
 
-	nents = dma_map_sg(chan->device->dev,
-			   req->sgt.sgl, req->sgt.nents, dir);
-	if (nents == 0) {
+	ret = dma_map_sgtable(chan->device->dev, req->sgt, dir, 0);
+	if (ret) {
 		rmcd_error("Failed to map SG list");
 		ret = -EFAULT;
 		goto err_pg;
-- 
2.17.1

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Re: [PATCH v6 32/36] rapidio: fix common struct sg_table related issues

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 11343 bytes --]

Hi Marek,

I love your patch! Yet something to improve:

[auto build test ERROR on next-20200618]
[also build test ERROR on v5.8-rc1]
[cannot apply to linuxtv-media/master staging/staging-testing drm-exynos/exynos-drm-next drm-intel/for-linux-next linus/master v5.8-rc1 v5.7 v5.7-rc7]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use  as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Marek-Szyprowski/DRM-fix-struct-sg_table-nents-vs-orig_nents-misuse/20200619-000417
base:    ce2cc8efd7a40cbd17841add878cb691d0ce0bba
config: alpha-allyesconfig (attached as .config)
compiler: alpha-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=alpha 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   In file included from include/linux/dma-mapping.h:11,
                    from drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:25:
   drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c: In function 'amdgpu_vram_mgr_alloc_sgt':
>> include/linux/scatterlist.h:158:17: error: '*sgt' is a pointer; did you mean to use '->'?
     158 |  for_each_sg(sgt->sgl, sg, sgt->orig_nents, i)
         |                 ^~
   include/linux/scatterlist.h:152:22: note: in definition of macro 'for_each_sg'
     152 |  for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg))
         |                      ^~~~~~
   drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:480:2: note: in expansion of macro 'for_each_sgtable_sg'
     480 |  for_each_sgtable_sg(*sgt, sg, i)
         |  ^~~~~~~~~~~~~~~~~~~
   include/linux/scatterlist.h:158:31: error: '*sgt' is a pointer; did you mean to use '->'?
     158 |  for_each_sg(sgt->sgl, sg, sgt->orig_nents, i)
         |                               ^~
   include/linux/scatterlist.h:152:38: note: in definition of macro 'for_each_sg'
     152 |  for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg))
         |                                      ^~
   drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:480:2: note: in expansion of macro 'for_each_sgtable_sg'
     480 |  for_each_sgtable_sg(*sgt, sg, i)
         |  ^~~~~~~~~~~~~~~~~~~
>> include/linux/scatterlist.h:158:17: error: '*sgt' is a pointer; did you mean to use '->'?
     158 |  for_each_sg(sgt->sgl, sg, sgt->orig_nents, i)
         |                 ^~
   include/linux/scatterlist.h:152:22: note: in definition of macro 'for_each_sg'
     152 |  for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg))
         |                      ^~~~~~
   drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:484:2: note: in expansion of macro 'for_each_sgtable_sg'
     484 |  for_each_sgtable_sg(*sgt, sg, i) {
         |  ^~~~~~~~~~~~~~~~~~~
   include/linux/scatterlist.h:158:31: error: '*sgt' is a pointer; did you mean to use '->'?
     158 |  for_each_sg(sgt->sgl, sg, sgt->orig_nents, i)
         |                               ^~
   include/linux/scatterlist.h:152:38: note: in definition of macro 'for_each_sg'
     152 |  for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg))
         |                                      ^~
   drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:484:2: note: in expansion of macro 'for_each_sgtable_sg'
     484 |  for_each_sgtable_sg(*sgt, sg, i) {
         |  ^~~~~~~~~~~~~~~~~~~
>> include/linux/scatterlist.h:158:17: error: '*sgt' is a pointer; did you mean to use '->'?
     158 |  for_each_sg(sgt->sgl, sg, sgt->orig_nents, i)
         |                 ^~
   include/linux/scatterlist.h:152:22: note: in definition of macro 'for_each_sg'
     152 |  for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg))
         |                      ^~~~~~
   drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:504:2: note: in expansion of macro 'for_each_sgtable_sg'
     504 |  for_each_sgtable_sg(*sgt, sg, i) {
         |  ^~~~~~~~~~~~~~~~~~~
   include/linux/scatterlist.h:158:31: error: '*sgt' is a pointer; did you mean to use '->'?
     158 |  for_each_sg(sgt->sgl, sg, sgt->orig_nents, i)
         |                               ^~
   include/linux/scatterlist.h:152:38: note: in definition of macro 'for_each_sg'
     152 |  for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg))
         |                                      ^~
   drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:504:2: note: in expansion of macro 'for_each_sgtable_sg'
     504 |  for_each_sgtable_sg(*sgt, sg, i) {
         |  ^~~~~~~~~~~~~~~~~~~
   In file included from drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:26:
   At top level:
   drivers/gpu/drm/amd/amdgpu/amdgpu.h:190:18: warning: 'sched_policy' defined but not used [-Wunused-const-variable=]
     190 | static const int sched_policy = KFD_SCHED_POLICY_HWS;
         |                  ^~~~~~~~~~~~
   In file included from drivers/gpu/drm/amd/amdgpu/../display/dc/dc_types.h:33,
                    from drivers/gpu/drm/amd/amdgpu/../display/dc/dm_services_types.h:30,
                    from drivers/gpu/drm/amd/amdgpu/../include/dm_pp_interface.h:26,
                    from drivers/gpu/drm/amd/amdgpu/amdgpu.h:65,
                    from drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c:26:
   drivers/gpu/drm/amd/amdgpu/../display/include/fixed31_32.h:76:32: warning: 'dc_fixpt_ln2_div_2' defined but not used [-Wunused-const-variable=]
      76 | static const struct fixed31_32 dc_fixpt_ln2_div_2 = { 1488522236LL };
         |                                ^~~~~~~~~~~~~~~~~~
   drivers/gpu/drm/amd/amdgpu/../display/include/fixed31_32.h:75:32: warning: 'dc_fixpt_ln2' defined but not used [-Wunused-const-variable=]
      75 | static const struct fixed31_32 dc_fixpt_ln2 = { 2977044471LL };
         |                                ^~~~~~~~~~~~
   drivers/gpu/drm/amd/amdgpu/../display/include/fixed31_32.h:74:32: warning: 'dc_fixpt_e' defined but not used [-Wunused-const-variable=]
      74 | static const struct fixed31_32 dc_fixpt_e = { 11674931555LL };
         |                                ^~~~~~~~~~
   drivers/gpu/drm/amd/amdgpu/../display/include/fixed31_32.h:73:32: warning: 'dc_fixpt_two_pi' defined but not used [-Wunused-const-variable=]
      73 | static const struct fixed31_32 dc_fixpt_two_pi = { 26986075409LL };
         |                                ^~~~~~~~~~~~~~~
   drivers/gpu/drm/amd/amdgpu/../display/include/fixed31_32.h:72:32: warning: 'dc_fixpt_pi' defined but not used [-Wunused-const-variable=]
      72 | static const struct fixed31_32 dc_fixpt_pi = { 13493037705LL };
         |                                ^~~~~~~~~~~
   drivers/gpu/drm/amd/amdgpu/../display/include/fixed31_32.h:67:32: warning: 'dc_fixpt_zero' defined but not used [-Wunused-const-variable=]
      67 | static const struct fixed31_32 dc_fixpt_zero = { 0 };
         |                                ^~~~~~~~~~~~~
--
   In file included from include/linux/kernel.h:11,
                    from include/linux/delay.h:22,
                    from drivers/gpu/drm/v3d/v3d_drv.h:4,
                    from drivers/gpu/drm/v3d/v3d_mmu.c:21:
   drivers/gpu/drm/v3d/v3d_mmu.c: In function 'v3d_mmu_insert_ptes':
>> include/linux/compiler.h:339:38: error: call to '__compiletime_assert_254' declared with attribute error: BUILD_BUG_ON failed: V3D_MMU_PAGE_SHIFT != PAGE_SIZE
     339 |  _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
         |                                      ^
   include/linux/compiler.h:320:4: note: in definition of macro '__compiletime_assert'
     320 |    prefix ## suffix();    \
         |    ^~~~~~
   include/linux/compiler.h:339:2: note: in expansion of macro '_compiletime_assert'
     339 |  _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
         |  ^~~~~~~~~~~~~~~~~~~
   include/linux/build_bug.h:39:37: note: in expansion of macro 'compiletime_assert'
      39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
         |                                     ^~~~~~~~~~~~~~~~~~
   include/linux/build_bug.h:50:2: note: in expansion of macro 'BUILD_BUG_ON_MSG'
      50 |  BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
         |  ^~~~~~~~~~~~~~~~
   drivers/gpu/drm/v3d/v3d_mmu.c:100:3: note: in expansion of macro 'BUILD_BUG_ON'
     100 |   BUILD_BUG_ON(V3D_MMU_PAGE_SHIFT != PAGE_SIZE);
         |   ^~~~~~~~~~~~
--
   drivers/rapidio/devices/rio_mport_cdev.c: In function 'dma_req_free':
>> drivers/rapidio/devices/rio_mport_cdev.c:576:48: error: incompatible type for argument 2 of 'dma_unmap_sgtable'
     576 |  dma_unmap_sgtable(req->dmach->device->dev, req->sgt, req->dir, 0);
         |                                             ~~~^~~~~
         |                                                |
         |                                                struct sg_table
   In file included from drivers/rapidio/devices/rio_mport_cdev.c:32:
   include/linux/dma-mapping.h:651:75: note: expected 'struct sg_table *' but argument is of type 'struct sg_table'
     651 | static inline void dma_unmap_sgtable(struct device *dev, struct sg_table *sgt,
         |                                                          ~~~~~~~~~~~~~~~~~^~~
   drivers/rapidio/devices/rio_mport_cdev.c: In function 'rio_dma_transfer':
>> drivers/rapidio/devices/rio_mport_cdev.c:932:46: error: incompatible type for argument 2 of 'dma_map_sgtable'
     932 |  ret = dma_map_sgtable(chan->device->dev, req->sgt, dir, 0);
         |                                           ~~~^~~~~
         |                                              |
         |                                              struct sg_table
   In file included from drivers/rapidio/devices/rio_mport_cdev.c:32:
   include/linux/dma-mapping.h:628:72: note: expected 'struct sg_table *' but argument is of type 'struct sg_table'
     628 | static inline int dma_map_sgtable(struct device *dev, struct sg_table *sgt,
         |                                                       ~~~~~~~~~~~~~~~~~^~~

vim +/dma_unmap_sgtable +576 drivers/rapidio/devices/rio_mport_cdev.c

   569	
   570	static void dma_req_free(struct kref *ref)
   571	{
   572		struct mport_dma_req *req = container_of(ref, struct mport_dma_req,
   573				refcount);
   574		struct mport_cdev_priv *priv = req->priv;
   575	
 > 576		dma_unmap_sgtable(req->dmach->device->dev, req->sgt, req->dir, 0);
   577		sg_free_table(&req->sgt);
   578		if (req->page_list) {
   579			unpin_user_pages(req->page_list, req->nr_pages);
   580			kfree(req->page_list);
   581		}
   582	
   583		if (req->map) {
   584			mutex_lock(&req->map->md->buf_mutex);
   585			kref_put(&req->map->ref, mport_release_mapping);
   586			mutex_unlock(&req->map->md->buf_mutex);
   587		}
   588	
   589		kref_put(&priv->dma_ref, mport_release_dma);
   590	
   591		kfree(req);
   592	}
   593	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 65125 bytes --]

[-- Attachment #3: Type: text/plain, Size: 156 bytes --]

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[PATCH v6 33/36] samples: vfio-mdev/mbochs: fix common struct sg_table related issues

[Marek Szyprowski]

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

While touching this code, also add missing call to dma_unmap_sgtable.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 samples/vfio-mdev/mbochs.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c
index 3cc5e5921682..e03068917273 100644
--- a/samples/vfio-mdev/mbochs.c
+++ b/samples/vfio-mdev/mbochs.c
@@ -846,7 +846,7 @@ static struct sg_table *mbochs_map_dmabuf(struct dma_buf_attachment *at,
 	if (sg_alloc_table_from_pages(sg, dmabuf->pages, dmabuf->pagecount,
 				      0, dmabuf->mode.size, GFP_KERNEL) < 0)
 		goto err2;
-	if (!dma_map_sg(at->dev, sg->sgl, sg->nents, direction))
+	if (dma_map_sgtable(at->dev, sg, direction, 0))
 		goto err3;
 
 	return sg;
@@ -868,6 +868,7 @@ static void mbochs_unmap_dmabuf(struct dma_buf_attachment *at,
 
 	dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
 
+	dma_unmap_sgtable(at->dev, sg, direction, 0);
 	sg_free_table(sg);
 	kfree(sg);
 }
-- 
2.17.1

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[PATCH v6 34/36] media: pci: fix common ALSA DMA-mapping related codes

[Marek Szyprowski]

The Documentation/DMA-API-HOWTO.txt states that dma_map_sg returns the
numer of the created entries in the DMA address space. However the
subsequent calls to dma_sync_sg_for_{device,cpu} and dma_unmap_sg must be
called with the original number of entries passed to dma_map_sg. The
sg_table->nents in turn holds the result of the dma_map_sg call as stated
in include/linux/scatterlist.h. Adapt the code to obey those rules.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 drivers/media/pci/cx23885/cx23885-alsa.c | 2 +-
 drivers/media/pci/cx25821/cx25821-alsa.c | 2 +-
 drivers/media/pci/cx88/cx88-alsa.c       | 2 +-
 drivers/media/pci/saa7134/saa7134-alsa.c | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/media/pci/cx23885/cx23885-alsa.c b/drivers/media/pci/cx23885/cx23885-alsa.c
index df44ed7393a0..3f366e4e4685 100644
--- a/drivers/media/pci/cx23885/cx23885-alsa.c
+++ b/drivers/media/pci/cx23885/cx23885-alsa.c
@@ -129,7 +129,7 @@ static int cx23885_alsa_dma_unmap(struct cx23885_audio_dev *dev)
 	if (!buf->sglen)
 		return 0;
 
-	dma_unmap_sg(&dev->pci->dev, buf->sglist, buf->sglen, PCI_DMA_FROMDEVICE);
+	dma_unmap_sg(&dev->pci->dev, buf->sglist, buf->nr_pages, PCI_DMA_FROMDEVICE);
 	buf->sglen = 0;
 	return 0;
 }
diff --git a/drivers/media/pci/cx25821/cx25821-alsa.c b/drivers/media/pci/cx25821/cx25821-alsa.c
index 301616426d8a..c40304d33776 100644
--- a/drivers/media/pci/cx25821/cx25821-alsa.c
+++ b/drivers/media/pci/cx25821/cx25821-alsa.c
@@ -193,7 +193,7 @@ static int cx25821_alsa_dma_unmap(struct cx25821_audio_dev *dev)
 	if (!buf->sglen)
 		return 0;
 
-	dma_unmap_sg(&dev->pci->dev, buf->sglist, buf->sglen, PCI_DMA_FROMDEVICE);
+	dma_unmap_sg(&dev->pci->dev, buf->sglist, buf->nr_pages, PCI_DMA_FROMDEVICE);
 	buf->sglen = 0;
 	return 0;
 }
diff --git a/drivers/media/pci/cx88/cx88-alsa.c b/drivers/media/pci/cx88/cx88-alsa.c
index 7d7aceecc985..3c6fe6ceb0b7 100644
--- a/drivers/media/pci/cx88/cx88-alsa.c
+++ b/drivers/media/pci/cx88/cx88-alsa.c
@@ -332,7 +332,7 @@ static int cx88_alsa_dma_unmap(struct cx88_audio_dev *dev)
 	if (!buf->sglen)
 		return 0;
 
-	dma_unmap_sg(&dev->pci->dev, buf->sglist, buf->sglen,
+	dma_unmap_sg(&dev->pci->dev, buf->sglist, buf->nr_pages,
 		     PCI_DMA_FROMDEVICE);
 	buf->sglen = 0;
 	return 0;
diff --git a/drivers/media/pci/saa7134/saa7134-alsa.c b/drivers/media/pci/saa7134/saa7134-alsa.c
index 544ca57eee75..398c47ff473d 100644
--- a/drivers/media/pci/saa7134/saa7134-alsa.c
+++ b/drivers/media/pci/saa7134/saa7134-alsa.c
@@ -313,7 +313,7 @@ static int saa7134_alsa_dma_unmap(struct saa7134_dev *dev)
 	if (!dma->sglen)
 		return 0;
 
-	dma_unmap_sg(&dev->pci->dev, dma->sglist, dma->sglen, PCI_DMA_FROMDEVICE);
+	dma_unmap_sg(&dev->pci->dev, dma->sglist, dma->nr_pages, PCI_DMA_FROMDEVICE);
 	dma->sglen = 0;
 	return 0;
 }
-- 
2.17.1

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[PATCH v6 35/36] videobuf2: use sgtable-based scatterlist wrappers

[Marek Szyprowski]

Use recently introduced common wrappers operating directly on the struct
sg_table objects and scatterlist page iterators to make the code a bit
more compact, robust, easier to follow and copy/paste safe.

No functional change, because the code already properly did all the
scaterlist related calls.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
 .../common/videobuf2/videobuf2-dma-contig.c   | 41 ++++++++-----------
 .../media/common/videobuf2/videobuf2-dma-sg.c | 32 ++++++---------
 .../common/videobuf2/videobuf2-vmalloc.c      | 12 ++----
 3 files changed, 34 insertions(+), 51 deletions(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
index f4b4a7c135eb..ba01a8692d88 100644
--- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c
+++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
@@ -48,16 +48,15 @@ struct vb2_dc_buf {
 
 static unsigned long vb2_dc_get_contiguous_size(struct sg_table *sgt)
 {
-	struct scatterlist *s;
 	dma_addr_t expected = sg_dma_address(sgt->sgl);
-	unsigned int i;
+	struct sg_dma_page_iter dma_iter;
 	unsigned long size = 0;
 
-	for_each_sg(sgt->sgl, s, sgt->nents, i) {
-		if (sg_dma_address(s) != expected)
+	for_each_sgtable_dma_page(sgt, &dma_iter, 0) {
+		if (sg_page_iter_dma_address(&dma_iter) != expected)
 			break;
-		expected = sg_dma_address(s) + sg_dma_len(s);
-		size += sg_dma_len(s);
+		expected += PAGE_SIZE;
+		size += PAGE_SIZE;
 	}
 	return size;
 }
@@ -99,8 +98,7 @@ static void vb2_dc_prepare(void *buf_priv)
 	if (!sgt || buf->db_attach)
 		return;
 
-	dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->orig_nents,
-			       buf->dma_dir);
+	dma_sync_sgtable_for_device(buf->dev, sgt, buf->dma_dir);
 }
 
 static void vb2_dc_finish(void *buf_priv)
@@ -112,7 +110,7 @@ static void vb2_dc_finish(void *buf_priv)
 	if (!sgt || buf->db_attach)
 		return;
 
-	dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir);
+	dma_sync_sgtable_for_cpu(buf->dev, sgt, buf->dma_dir);
 }
 
 /*********************************************/
@@ -273,8 +271,8 @@ static void vb2_dc_dmabuf_ops_detach(struct dma_buf *dbuf,
 		 * memory locations do not require any explicit cache
 		 * maintenance prior or after being used by the device.
 		 */
-		dma_unmap_sg_attrs(db_attach->dev, sgt->sgl, sgt->orig_nents,
-				   attach->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
+		dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir,
+				  DMA_ATTR_SKIP_CPU_SYNC);
 	sg_free_table(sgt);
 	kfree(attach);
 	db_attach->priv = NULL;
@@ -299,8 +297,8 @@ static struct sg_table *vb2_dc_dmabuf_ops_map(
 
 	/* release any previous cache */
 	if (attach->dma_dir != DMA_NONE) {
-		dma_unmap_sg_attrs(db_attach->dev, sgt->sgl, sgt->orig_nents,
-				   attach->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
+		dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir,
+				  DMA_ATTR_SKIP_CPU_SYNC);
 		attach->dma_dir = DMA_NONE;
 	}
 
@@ -308,9 +306,8 @@ static struct sg_table *vb2_dc_dmabuf_ops_map(
 	 * mapping to the client with new direction, no cache sync
 	 * required see comment in vb2_dc_dmabuf_ops_detach()
 	 */
-	sgt->nents = dma_map_sg_attrs(db_attach->dev, sgt->sgl, sgt->orig_nents,
-				      dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
-	if (!sgt->nents) {
+	if (dma_map_sgtable(db_attach->dev, sgt, dma_dir,
+			    DMA_ATTR_SKIP_CPU_SYNC)) {
 		pr_err("failed to map scatterlist\n");
 		mutex_unlock(lock);
 		return ERR_PTR(-EIO);
@@ -423,8 +420,8 @@ static void vb2_dc_put_userptr(void *buf_priv)
 		 * No need to sync to CPU, it's already synced to the CPU
 		 * since the finish() memop will have been called before this.
 		 */
-		dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
-				   buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
+		dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir,
+				  DMA_ATTR_SKIP_CPU_SYNC);
 		pages = frame_vector_pages(buf->vec);
 		/* sgt should exist only if vector contains pages... */
 		BUG_ON(IS_ERR(pages));
@@ -521,9 +518,8 @@ static void *vb2_dc_get_userptr(struct device *dev, unsigned long vaddr,
 	 * No need to sync to the device, this will happen later when the
 	 * prepare() memop is called.
 	 */
-	sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
-				      buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
-	if (sgt->nents <= 0) {
+	if (dma_map_sgtable(buf->dev, sgt, buf->dma_dir,
+			    DMA_ATTR_SKIP_CPU_SYNC)) {
 		pr_err("failed to map scatterlist\n");
 		ret = -EIO;
 		goto fail_sgt_init;
@@ -545,8 +541,7 @@ static void *vb2_dc_get_userptr(struct device *dev, unsigned long vaddr,
 	return buf;
 
 fail_map_sg:
-	dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
-			   buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
+	dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
 
 fail_sgt_init:
 	sg_free_table(sgt);
diff --git a/drivers/media/common/videobuf2/videobuf2-dma-sg.c b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
index 92072a08af25..6ddf953efa11 100644
--- a/drivers/media/common/videobuf2/videobuf2-dma-sg.c
+++ b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
@@ -142,9 +142,8 @@ static void *vb2_dma_sg_alloc(struct device *dev, unsigned long dma_attrs,
 	 * No need to sync to the device, this will happen later when the
 	 * prepare() memop is called.
 	 */
-	sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
-				      buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
-	if (!sgt->nents)
+	if (dma_map_sgtable(buf->dev, sgt, buf->dma_dir,
+			    DMA_ATTR_SKIP_CPU_SYNC)) {
 		goto fail_map;
 
 	buf->handler.refcount = &buf->refcount;
@@ -180,8 +179,8 @@ static void vb2_dma_sg_put(void *buf_priv)
 	if (refcount_dec_and_test(&buf->refcount)) {
 		dprintk(1, "%s: Freeing buffer of %d pages\n", __func__,
 			buf->num_pages);
-		dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
-				   buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
+		dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir,
+				  DMA_ATTR_SKIP_CPU_SYNC);
 		if (buf->vaddr)
 			vm_unmap_ram(buf->vaddr, buf->num_pages);
 		sg_free_table(buf->dma_sgt);
@@ -202,8 +201,7 @@ static void vb2_dma_sg_prepare(void *buf_priv)
 	if (buf->db_attach)
 		return;
 
-	dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->orig_nents,
-			       buf->dma_dir);
+	dma_sync_sgtable_for_device(buf->dev, sgt, buf->dma_dir);
 }
 
 static void vb2_dma_sg_finish(void *buf_priv)
@@ -215,7 +213,7 @@ static void vb2_dma_sg_finish(void *buf_priv)
 	if (buf->db_attach)
 		return;
 
-	dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir);
+	dma_sync_sgtable_for_cpu(buf->dev, sgt, buf->dma_dir);
 }
 
 static void *vb2_dma_sg_get_userptr(struct device *dev, unsigned long vaddr,
@@ -258,9 +256,8 @@ static void *vb2_dma_sg_get_userptr(struct device *dev, unsigned long vaddr,
 	 * No need to sync to the device, this will happen later when the
 	 * prepare() memop is called.
 	 */
-	sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
-				      buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
-	if (!sgt->nents)
+	if (dma_map_sgtable(buf->dev, sgt, buf->dma_dir,
+			    DMA_ATTR_SKIP_CPU_SYNC)) {
 		goto userptr_fail_map;
 
 	return buf;
@@ -286,8 +283,7 @@ static void vb2_dma_sg_put_userptr(void *buf_priv)
 
 	dprintk(1, "%s: Releasing userspace buffer of %d pages\n",
 	       __func__, buf->num_pages);
-	dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir,
-			   DMA_ATTR_SKIP_CPU_SYNC);
+	dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
 	if (buf->vaddr)
 		vm_unmap_ram(buf->vaddr, buf->num_pages);
 	sg_free_table(buf->dma_sgt);
@@ -410,8 +406,7 @@ static void vb2_dma_sg_dmabuf_ops_detach(struct dma_buf *dbuf,
 
 	/* release the scatterlist cache */
 	if (attach->dma_dir != DMA_NONE)
-		dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
-			attach->dma_dir);
+		dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir);
 	sg_free_table(sgt);
 	kfree(attach);
 	db_attach->priv = NULL;
@@ -436,15 +431,12 @@ static struct sg_table *vb2_dma_sg_dmabuf_ops_map(
 
 	/* release any previous cache */
 	if (attach->dma_dir != DMA_NONE) {
-		dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
-			attach->dma_dir);
+		dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir);
 		attach->dma_dir = DMA_NONE;
 	}
 
 	/* mapping to the client with new direction */
-	sgt->nents = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
-				dma_dir);
-	if (!sgt->nents) {
+	if (dma_map_sgtable(db_attach->dev, sgt, dma_dir, 0)) {
 		pr_err("failed to map scatterlist\n");
 		mutex_unlock(lock);
 		return ERR_PTR(-EIO);
diff --git a/drivers/media/common/videobuf2/videobuf2-vmalloc.c b/drivers/media/common/videobuf2/videobuf2-vmalloc.c
index c66fda4a65e4..bf5ac63a5742 100644
--- a/drivers/media/common/videobuf2/videobuf2-vmalloc.c
+++ b/drivers/media/common/videobuf2/videobuf2-vmalloc.c
@@ -229,7 +229,7 @@ static int vb2_vmalloc_dmabuf_ops_attach(struct dma_buf *dbuf,
 		kfree(attach);
 		return ret;
 	}
-	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
+	for_each_sgtable_sg(sgt, sg, i) {
 		struct page *page = vmalloc_to_page(vaddr);
 
 		if (!page) {
@@ -259,8 +259,7 @@ static void vb2_vmalloc_dmabuf_ops_detach(struct dma_buf *dbuf,
 
 	/* release the scatterlist cache */
 	if (attach->dma_dir != DMA_NONE)
-		dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
-			attach->dma_dir);
+		dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir, 0);
 	sg_free_table(sgt);
 	kfree(attach);
 	db_attach->priv = NULL;
@@ -285,15 +284,12 @@ static struct sg_table *vb2_vmalloc_dmabuf_ops_map(
 
 	/* release any previous cache */
 	if (attach->dma_dir != DMA_NONE) {
-		dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
-			attach->dma_dir);
+		dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir, 0);
 		attach->dma_dir = DMA_NONE;
 	}
 
 	/* mapping to the client with new direction */
-	sgt->nents = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
-				dma_dir);
-	if (!sgt->nents) {
+	if (dma_map_sgtable(db_attach->dev, sgt, dma_dir, 0)) {
 		pr_err("failed to map scatterlist\n");
 		mutex_unlock(lock);
 		return ERR_PTR(-EIO);
-- 
2.17.1

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

Re: [PATCH v6 35/36] videobuf2: use sgtable-based scatterlist wrappers

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 58775 bytes --]

Hi Marek,

I love your patch! Yet something to improve:

[auto build test ERROR on next-20200618]
[also build test ERROR on v5.8-rc1]
[cannot apply to linuxtv-media/master staging/staging-testing drm-exynos/exynos-drm-next drm-intel/for-linux-next linus/master v5.8-rc1 v5.7 v5.7-rc7]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use  as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Marek-Szyprowski/DRM-fix-struct-sg_table-nents-vs-orig_nents-misuse/20200619-000417
base:    ce2cc8efd7a40cbd17841add878cb691d0ce0bba
config: alpha-allyesconfig (attached as .config)
compiler: alpha-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=alpha 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All error/warnings (new ones prefixed by >>):

   drivers/media/common/videobuf2/videobuf2-dma-sg.c: In function 'vb2_dma_sg_alloc':
>> drivers/media/common/videobuf2/videobuf2-dma-sg.c:173:13: error: invalid storage class for function 'vb2_dma_sg_put'
     173 | static void vb2_dma_sg_put(void *buf_priv)
         |             ^~~~~~~~~~~~~~
>> drivers/media/common/videobuf2/videobuf2-dma-sg.c:173:1: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
     173 | static void vb2_dma_sg_put(void *buf_priv)
         | ^~~~~~
>> drivers/media/common/videobuf2/videobuf2-dma-sg.c:195:13: error: invalid storage class for function 'vb2_dma_sg_prepare'
     195 | static void vb2_dma_sg_prepare(void *buf_priv)
         |             ^~~~~~~~~~~~~~~~~~
>> drivers/media/common/videobuf2/videobuf2-dma-sg.c:207:13: error: invalid storage class for function 'vb2_dma_sg_finish'
     207 | static void vb2_dma_sg_finish(void *buf_priv)
         |             ^~~~~~~~~~~~~~~~~
>> drivers/media/common/videobuf2/videobuf2-dma-sg.c:219:14: error: invalid storage class for function 'vb2_dma_sg_get_userptr'
     219 | static void *vb2_dma_sg_get_userptr(struct device *dev, unsigned long vaddr,
         |              ^~~~~~~~~~~~~~~~~~~~~~
   drivers/media/common/videobuf2/videobuf2-dma-sg.c: In function 'vb2_dma_sg_get_userptr':
>> drivers/media/common/videobuf2/videobuf2-dma-sg.c:278:13: error: invalid storage class for function 'vb2_dma_sg_put_userptr'
     278 | static void vb2_dma_sg_put_userptr(void *buf_priv)
         |             ^~~~~~~~~~~~~~~~~~~~~~
   drivers/media/common/videobuf2/videobuf2-dma-sg.c:278:1: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
     278 | static void vb2_dma_sg_put_userptr(void *buf_priv)
         | ^~~~~~
>> drivers/media/common/videobuf2/videobuf2-dma-sg.c:298:14: error: invalid storage class for function 'vb2_dma_sg_vaddr'
     298 | static void *vb2_dma_sg_vaddr(void *buf_priv)
         |              ^~~~~~~~~~~~~~~~
>> drivers/media/common/videobuf2/videobuf2-dma-sg.c:315:21: error: invalid storage class for function 'vb2_dma_sg_num_users'
     315 | static unsigned int vb2_dma_sg_num_users(void *buf_priv)
         |                     ^~~~~~~~~~~~~~~~~~~~
>> drivers/media/common/videobuf2/videobuf2-dma-sg.c:322:12: error: invalid storage class for function 'vb2_dma_sg_mmap'
     322 | static int vb2_dma_sg_mmap(void *buf_priv, struct vm_area_struct *vma)
         |            ^~~~~~~~~~~~~~~
>> drivers/media/common/videobuf2/videobuf2-dma-sg.c:358:12: error: invalid storage class for function 'vb2_dma_sg_dmabuf_ops_attach'
     358 | static int vb2_dma_sg_dmabuf_ops_attach(struct dma_buf *dbuf,
         |            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/media/common/videobuf2/videobuf2-dma-sg.c:396:13: error: invalid storage class for function 'vb2_dma_sg_dmabuf_ops_detach'
     396 | static void vb2_dma_sg_dmabuf_ops_detach(struct dma_buf *dbuf,
         |             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/media/common/videobuf2/videobuf2-dma-sg.c: In function 'vb2_dma_sg_dmabuf_ops_detach':
>> drivers/media/common/videobuf2/videobuf2-dma-sg.c:409:3: error: too few arguments to function 'dma_unmap_sgtable'
     409 |   dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir);
         |   ^~~~~~~~~~~~~~~~~
   In file included from include/linux/dma-buf.h:20,
                    from include/media/videobuf2-core.h:18,
                    from include/media/videobuf2-v4l2.h:16,
                    from drivers/media/common/videobuf2/videobuf2-dma-sg.c:21:
   include/linux/dma-mapping.h:651:20: note: declared here
     651 | static inline void dma_unmap_sgtable(struct device *dev, struct sg_table *sgt,
         |                    ^~~~~~~~~~~~~~~~~
   drivers/media/common/videobuf2/videobuf2-dma-sg.c: In function 'vb2_dma_sg_get_userptr':
>> drivers/media/common/videobuf2/videobuf2-dma-sg.c:415:25: error: invalid storage class for function 'vb2_dma_sg_dmabuf_ops_map'
     415 | static struct sg_table *vb2_dma_sg_dmabuf_ops_map(
         |                         ^~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/media/common/videobuf2/videobuf2-dma-sg.c: In function 'vb2_dma_sg_dmabuf_ops_map':
   drivers/media/common/videobuf2/videobuf2-dma-sg.c:434:3: error: too few arguments to function 'dma_unmap_sgtable'
     434 |   dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir);
         |   ^~~~~~~~~~~~~~~~~
   In file included from include/linux/dma-buf.h:20,
                    from include/media/videobuf2-core.h:18,
                    from include/media/videobuf2-v4l2.h:16,
                    from drivers/media/common/videobuf2/videobuf2-dma-sg.c:21:
   include/linux/dma-mapping.h:651:20: note: declared here
     651 | static inline void dma_unmap_sgtable(struct device *dev, struct sg_table *sgt,
         |                    ^~~~~~~~~~~~~~~~~
   drivers/media/common/videobuf2/videobuf2-dma-sg.c: In function 'vb2_dma_sg_get_userptr':
>> drivers/media/common/videobuf2/videobuf2-dma-sg.c:452:13: error: invalid storage class for function 'vb2_dma_sg_dmabuf_ops_unmap'
     452 | static void vb2_dma_sg_dmabuf_ops_unmap(struct dma_buf_attachment *db_attach,
         |             ^~~~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/media/common/videobuf2/videobuf2-dma-sg.c:458:13: error: invalid storage class for function 'vb2_dma_sg_dmabuf_ops_release'
     458 | static void vb2_dma_sg_dmabuf_ops_release(struct dma_buf *dbuf)
         |             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/media/common/videobuf2/videobuf2-dma-sg.c:464:14: error: invalid storage class for function 'vb2_dma_sg_dmabuf_ops_vmap'
     464 | static void *vb2_dma_sg_dmabuf_ops_vmap(struct dma_buf *dbuf)
         |              ^~~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/media/common/videobuf2/videobuf2-dma-sg.c:471:12: error: invalid storage class for function 'vb2_dma_sg_dmabuf_ops_mmap'
     471 | static int vb2_dma_sg_dmabuf_ops_mmap(struct dma_buf *dbuf,
         |            ^~~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/media/common/videobuf2/videobuf2-dma-sg.c:478:12: error: initializer element is not constant
     478 |  .attach = vb2_dma_sg_dmabuf_ops_attach,
         |            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/media/common/videobuf2/videobuf2-dma-sg.c:478:12: note: (near initialization for 'vb2_dma_sg_dmabuf_ops.attach')
   drivers/media/common/videobuf2/videobuf2-dma-sg.c:479:12: error: initializer element is not constant
     479 |  .detach = vb2_dma_sg_dmabuf_ops_detach,
         |            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/media/common/videobuf2/videobuf2-dma-sg.c:479:12: note: (near initialization for 'vb2_dma_sg_dmabuf_ops.detach')
   drivers/media/common/videobuf2/videobuf2-dma-sg.c:480:17: error: initializer element is not constant
     480 |  .map_dma_buf = vb2_dma_sg_dmabuf_ops_map,
         |                 ^~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/media/common/videobuf2/videobuf2-dma-sg.c:480:17: note: (near initialization for 'vb2_dma_sg_dmabuf_ops.map_dma_buf')
   drivers/media/common/videobuf2/videobuf2-dma-sg.c:481:19: error: initializer element is not constant
     481 |  .unmap_dma_buf = vb2_dma_sg_dmabuf_ops_unmap,
         |                   ^~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/media/common/videobuf2/videobuf2-dma-sg.c:481:19: note: (near initialization for 'vb2_dma_sg_dmabuf_ops.unmap_dma_buf')
   drivers/media/common/videobuf2/videobuf2-dma-sg.c:482:10: error: initializer element is not constant
     482 |  .vmap = vb2_dma_sg_dmabuf_ops_vmap,
         |          ^~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/media/common/videobuf2/videobuf2-dma-sg.c:482:10: note: (near initialization for 'vb2_dma_sg_dmabuf_ops.vmap')
   drivers/media/common/videobuf2/videobuf2-dma-sg.c:483:10: error: initializer element is not constant
     483 |  .mmap = vb2_dma_sg_dmabuf_ops_mmap,
         |          ^~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/media/common/videobuf2/videobuf2-dma-sg.c:483:10: note: (near initialization for 'vb2_dma_sg_dmabuf_ops.mmap')
   drivers/media/common/videobuf2/videobuf2-dma-sg.c:484:13: error: initializer element is not constant
     484 |  .release = vb2_dma_sg_dmabuf_ops_release,
         |             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/media/common/videobuf2/videobuf2-dma-sg.c:484:13: note: (near initialization for 'vb2_dma_sg_dmabuf_ops.release')
>> drivers/media/common/videobuf2/videobuf2-dma-sg.c:487:24: error: invalid storage class for function 'vb2_dma_sg_get_dmabuf'
     487 | static struct dma_buf *vb2_dma_sg_get_dmabuf(void *buf_priv, unsigned long flags)
         |                        ^~~~~~~~~~~~~~~~~~~~~
>> drivers/media/common/videobuf2/videobuf2-dma-sg.c:515:12: error: invalid storage class for function 'vb2_dma_sg_map_dmabuf'
     515 | static int vb2_dma_sg_map_dmabuf(void *mem_priv)
         |            ^~~~~~~~~~~~~~~~~~~~~
   drivers/media/common/videobuf2/videobuf2-dma-sg.c:543:13: error: invalid storage class for function 'vb2_dma_sg_unmap_dmabuf'
     543 | static void vb2_dma_sg_unmap_dmabuf(void *mem_priv)
         |             ^~~~~~~~~~~~~~~~~~~~~~~
   drivers/media/common/videobuf2/videobuf2-dma-sg.c:567:13: error: invalid storage class for function 'vb2_dma_sg_detach_dmabuf'
     567 | static void vb2_dma_sg_detach_dmabuf(void *mem_priv)
         |             ^~~~~~~~~~~~~~~~~~~~~~~~
   drivers/media/common/videobuf2/videobuf2-dma-sg.c:580:14: error: invalid storage class for function 'vb2_dma_sg_attach_dmabuf'
     580 | static void *vb2_dma_sg_attach_dmabuf(struct device *dev, struct dma_buf *dbuf,
         |              ^~~~~~~~~~~~~~~~~~~~~~~~
   drivers/media/common/videobuf2/videobuf2-dma-sg.c:612:14: error: invalid storage class for function 'vb2_dma_sg_cookie'
     612 | static void *vb2_dma_sg_cookie(void *buf_priv)
         |              ^~~~~~~~~~~~~~~~~
   In file included from include/linux/linkage.h:7,
                    from include/linux/kernel.h:8,
                    from include/linux/list.h:9,
                    from include/linux/module.h:12,
                    from drivers/media/common/videobuf2/videobuf2-dma-sg.c:13:
   drivers/media/common/videobuf2/videobuf2-dma-sg.c:636:19: error: extern declaration of 'vb2_dma_sg_memops' follows declaration with no linkage
     636 | EXPORT_SYMBOL_GPL(vb2_dma_sg_memops);
         |                   ^~~~~~~~~~~~~~~~~
   include/linux/export.h:98:21: note: in definition of macro '___EXPORT_SYMBOL'
      98 |  extern typeof(sym) sym;       \
         |                     ^~~
   include/linux/export.h:155:34: note: in expansion of macro '__EXPORT_SYMBOL'
     155 | #define _EXPORT_SYMBOL(sym, sec) __EXPORT_SYMBOL(sym, sec, "")
         |                                  ^~~~~~~~~~~~~~~
   include/linux/export.h:159:33: note: in expansion of macro '_EXPORT_SYMBOL'
     159 | #define EXPORT_SYMBOL_GPL(sym)  _EXPORT_SYMBOL(sym, "_gpl")
         |                                 ^~~~~~~~~~~~~~
   drivers/media/common/videobuf2/videobuf2-dma-sg.c:636:1: note: in expansion of macro 'EXPORT_SYMBOL_GPL'
     636 | EXPORT_SYMBOL_GPL(vb2_dma_sg_memops);
         | ^~~~~~~~~~~~~~~~~
   drivers/media/common/videobuf2/videobuf2-dma-sg.c:619:26: note: previous definition of 'vb2_dma_sg_memops' was here
     619 | const struct vb2_mem_ops vb2_dma_sg_memops = {
         |                          ^~~~~~~~~~~~~~~~~
   In file included from include/linux/linkage.h:7,
                    from include/linux/kernel.h:8,
                    from include/linux/list.h:9,
                    from include/linux/module.h:12,
                    from drivers/media/common/videobuf2/videobuf2-dma-sg.c:13:
   include/linux/export.h:67:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
      67 |  static const struct kernel_symbol __ksymtab_##sym  \
         |  ^~~~~~
   include/linux/export.h:108:2: note: in expansion of macro '__KSYMTAB_ENTRY'
     108 |  __KSYMTAB_ENTRY(sym, sec)
         |  ^~~~~~~~~~~~~~~
   include/linux/export.h:147:39: note: in expansion of macro '___EXPORT_SYMBOL'
     147 | #define __EXPORT_SYMBOL(sym, sec, ns) ___EXPORT_SYMBOL(sym, sec, ns)
         |                                       ^~~~~~~~~~~~~~~~
   include/linux/export.h:155:34: note: in expansion of macro '__EXPORT_SYMBOL'
     155 | #define _EXPORT_SYMBOL(sym, sec) __EXPORT_SYMBOL(sym, sec, "")
         |                                  ^~~~~~~~~~~~~~~
   include/linux/export.h:159:33: note: in expansion of macro '_EXPORT_SYMBOL'
     159 | #define EXPORT_SYMBOL_GPL(sym)  _EXPORT_SYMBOL(sym, "_gpl")
         |                                 ^~~~~~~~~~~~~~
   drivers/media/common/videobuf2/videobuf2-dma-sg.c:636:1: note: in expansion of macro 'EXPORT_SYMBOL_GPL'
     636 | EXPORT_SYMBOL_GPL(vb2_dma_sg_memops);
         | ^~~~~~~~~~~~~~~~~
   drivers/media/common/videobuf2/videobuf2-dma-sg.c:640:1: error: expected declaration or statement at end of input
     640 | MODULE_LICENSE("GPL");
         | ^~~~~~~~~~~~~~
   drivers/media/common/videobuf2/videobuf2-dma-sg.c: In function 'vb2_dma_sg_alloc':
   drivers/media/common/videobuf2/videobuf2-dma-sg.c:640:1: error: expected declaration or statement at end of input
   drivers/media/common/videobuf2/videobuf2-dma-sg.c: At top level:
   drivers/media/common/videobuf2/videobuf2-dma-sg.c:56:13: warning: 'vb2_dma_sg_put' used but never defined
      56 | static void vb2_dma_sg_put(void *buf_priv);
         |             ^~~~~~~~~~~~~~
   drivers/media/common/videobuf2/videobuf2-dma-sg.c:219:14: warning: 'vb2_dma_sg_get_userptr' defined but not used [-Wunused-function]
     219 | static void *vb2_dma_sg_get_userptr(struct device *dev, unsigned long vaddr,
         |              ^~~~~~~~~~~~~~~~~~~~~~

vim +/vb2_dma_sg_put +173 drivers/media/common/videobuf2/videobuf2-dma-sg.c

5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29   55  
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  @56  static void vb2_dma_sg_put(void *buf_priv);
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29   57  
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   58  static int vb2_dma_sg_alloc_compacted(struct vb2_dma_sg_buf *buf,
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   59  		gfp_t gfp_flags)
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   60  {
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   61  	unsigned int last_page = 0;
14f28f5cea9e399 drivers/media/common/videobuf2/videobuf2-dma-sg.c Sakari Ailus          2018-12-12   62  	unsigned long size = buf->size;
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   63  
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   64  	while (size > 0) {
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   65  		struct page *pages;
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   66  		int order;
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   67  		int i;
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   68  
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   69  		order = get_order(size);
4b129dc907e9b95 drivers/media/common/videobuf2/videobuf2-dma-sg.c Mauro Carvalho Chehab 2019-02-18   70  		/* Don't over allocate*/
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   71  		if ((PAGE_SIZE << order) > size)
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   72  			order--;
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   73  
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   74  		pages = NULL;
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   75  		while (!pages) {
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   76  			pages = alloc_pages(GFP_KERNEL | __GFP_ZERO |
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   77  					__GFP_NOWARN | gfp_flags, order);
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   78  			if (pages)
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   79  				break;
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   80  
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   81  			if (order == 0) {
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   82  				while (last_page--)
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   83  					__free_page(buf->pages[last_page]);
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   84  				return -ENOMEM;
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   85  			}
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   86  			order--;
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   87  		}
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   88  
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   89  		split_page(pages, order);
223012475968fb8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   90  		for (i = 0; i < (1 << order); i++)
223012475968fb8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   91  			buf->pages[last_page++] = &pages[i];
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   92  
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   93  		size -= PAGE_SIZE << order;
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   94  	}
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   95  
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   96  	return 0;
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   97  }
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02   98  
00085f1efa387a8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Krzysztof Kozlowski   2016-08-03   99  static void *vb2_dma_sg_alloc(struct device *dev, unsigned long dma_attrs,
d16e832da23edff drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2016-04-15  100  			      unsigned long size, enum dma_data_direction dma_dir,
d16e832da23edff drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2016-04-15  101  			      gfp_t gfp_flags)
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  102  {
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  103  	struct vb2_dma_sg_buf *buf;
d790b7eda953df4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-24  104  	struct sg_table *sgt;
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02  105  	int ret;
223012475968fb8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02  106  	int num_pages;
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  107  
0ff657b0f6120cb drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2016-07-21  108  	if (WARN_ON(!dev))
0ff657b0f6120cb drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2016-07-21  109  		return ERR_PTR(-EINVAL);
0ff657b0f6120cb drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2016-07-21  110  
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  111  	buf = kzalloc(sizeof *buf, GFP_KERNEL);
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  112  	if (!buf)
0ff657b0f6120cb drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2016-07-21  113  		return ERR_PTR(-ENOMEM);
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  114  
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  115  	buf->vaddr = NULL;
d935c57e8fb6902 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  116  	buf->dma_dir = dma_dir;
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  117  	buf->offset = 0;
223012475968fb8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02  118  	buf->size = size;
7f8414594e47552 drivers/media/v4l2-core/videobuf2-dma-sg.c        Mauro Carvalho Chehab 2013-04-19  119  	/* size is already page aligned */
223012475968fb8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02  120  	buf->num_pages = size >> PAGE_SHIFT;
e078b79d8aa70a4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  121  	buf->dma_sgt = &buf->sg_table;
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  122  
758d90e161382c1 drivers/media/v4l2-core/videobuf2-dma-sg.c        Tomasz Figa           2017-06-19  123  	buf->pages = kvmalloc_array(buf->num_pages, sizeof(struct page *),
758d90e161382c1 drivers/media/v4l2-core/videobuf2-dma-sg.c        Tomasz Figa           2017-06-19  124  				    GFP_KERNEL | __GFP_ZERO);
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  125  	if (!buf->pages)
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  126  		goto fail_pages_array_alloc;
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  127  
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02  128  	ret = vb2_dma_sg_alloc_compacted(buf, gfp_flags);
df23728118cd0f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02  129  	if (ret)
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  130  		goto fail_pages_alloc;
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  131  
e078b79d8aa70a4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  132  	ret = sg_alloc_table_from_pages(buf->dma_sgt, buf->pages,
47bc59c52b005f5 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-08-01  133  			buf->num_pages, 0, size, GFP_KERNEL);
223012475968fb8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02  134  	if (ret)
223012475968fb8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02  135  		goto fail_table_alloc;
223012475968fb8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02  136  
0c3a14c177aa85a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  137  	/* Prevent the device from being released while the buffer is used */
36c0f8b32c4bd4f drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2016-04-15  138  	buf->dev = get_device(dev);
d790b7eda953df4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-24  139  
d790b7eda953df4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-24  140  	sgt = &buf->sg_table;
251a79f8f5adfd8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  141  	/*
251a79f8f5adfd8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  142  	 * No need to sync to the device, this will happen later when the
251a79f8f5adfd8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  143  	 * prepare() memop is called.
251a79f8f5adfd8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  144  	 */
b8bd9d592f68e3c drivers/media/common/videobuf2/videobuf2-dma-sg.c Marek Szyprowski      2020-06-18  145  	if (dma_map_sgtable(buf->dev, sgt, buf->dma_dir,
b8bd9d592f68e3c drivers/media/common/videobuf2/videobuf2-dma-sg.c Marek Szyprowski      2020-06-18  146  			    DMA_ATTR_SKIP_CPU_SYNC)) {
d790b7eda953df4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-24  147  		goto fail_map;
d790b7eda953df4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-24  148  
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  149  	buf->handler.refcount = &buf->refcount;
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  150  	buf->handler.put = vb2_dma_sg_put;
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  151  	buf->handler.arg = buf;
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  152  
6c4bb65d0be8f34 drivers/media/v4l2-core/videobuf2-dma-sg.c        Elena Reshetova       2017-03-06  153  	refcount_set(&buf->refcount, 1);
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  154  
ffdc78efe1a8a01 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2013-03-02  155  	dprintk(1, "%s: Allocated buffer of %d pages\n",
223012475968fb8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02  156  		__func__, buf->num_pages);
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  157  	return buf;
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  158  
d790b7eda953df4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-24  159  fail_map:
d790b7eda953df4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-24  160  	put_device(buf->dev);
e078b79d8aa70a4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  161  	sg_free_table(buf->dma_sgt);
223012475968fb8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02  162  fail_table_alloc:
223012475968fb8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02  163  	num_pages = buf->num_pages;
223012475968fb8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02  164  	while (num_pages--)
223012475968fb8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02  165  		__free_page(buf->pages[num_pages]);
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  166  fail_pages_alloc:
758d90e161382c1 drivers/media/v4l2-core/videobuf2-dma-sg.c        Tomasz Figa           2017-06-19  167  	kvfree(buf->pages);
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  168  fail_pages_array_alloc:
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  169  	kfree(buf);
0ff657b0f6120cb drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2016-07-21  170  	return ERR_PTR(-ENOMEM);
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  171  }
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  172  
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29 @173  static void vb2_dma_sg_put(void *buf_priv)
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  174  {
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  175  	struct vb2_dma_sg_buf *buf = buf_priv;
d790b7eda953df4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-24  176  	struct sg_table *sgt = &buf->sg_table;
223012475968fb8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02  177  	int i = buf->num_pages;
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  178  
6c4bb65d0be8f34 drivers/media/v4l2-core/videobuf2-dma-sg.c        Elena Reshetova       2017-03-06  179  	if (refcount_dec_and_test(&buf->refcount)) {
ffdc78efe1a8a01 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2013-03-02  180  		dprintk(1, "%s: Freeing buffer of %d pages\n", __func__,
223012475968fb8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02  181  			buf->num_pages);
b8bd9d592f68e3c drivers/media/common/videobuf2/videobuf2-dma-sg.c Marek Szyprowski      2020-06-18  182  		dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir,
b8bd9d592f68e3c drivers/media/common/videobuf2/videobuf2-dma-sg.c Marek Szyprowski      2020-06-18  183  				  DMA_ATTR_SKIP_CPU_SYNC);
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  184  		if (buf->vaddr)
223012475968fb8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02  185  			vm_unmap_ram(buf->vaddr, buf->num_pages);
e078b79d8aa70a4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  186  		sg_free_table(buf->dma_sgt);
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  187  		while (--i >= 0)
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  188  			__free_page(buf->pages[i]);
758d90e161382c1 drivers/media/v4l2-core/videobuf2-dma-sg.c        Tomasz Figa           2017-06-19  189  		kvfree(buf->pages);
0c3a14c177aa85a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  190  		put_device(buf->dev);
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  191  		kfree(buf);
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  192  	}
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  193  }
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  194  
d790b7eda953df4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-24 @195  static void vb2_dma_sg_prepare(void *buf_priv)
d790b7eda953df4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-24  196  {
d790b7eda953df4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-24  197  	struct vb2_dma_sg_buf *buf = buf_priv;
e078b79d8aa70a4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  198  	struct sg_table *sgt = buf->dma_sgt;
e078b79d8aa70a4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  199  
e078b79d8aa70a4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  200  	/* DMABUF exporter will flush the cache for us */
e078b79d8aa70a4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  201  	if (buf->db_attach)
e078b79d8aa70a4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  202  		return;
d790b7eda953df4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-24  203  
b8bd9d592f68e3c drivers/media/common/videobuf2/videobuf2-dma-sg.c Marek Szyprowski      2020-06-18  204  	dma_sync_sgtable_for_device(buf->dev, sgt, buf->dma_dir);
d790b7eda953df4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-24  205  }
d790b7eda953df4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-24  206  
d790b7eda953df4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-24 @207  static void vb2_dma_sg_finish(void *buf_priv)
d790b7eda953df4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-24  208  {
d790b7eda953df4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-24  209  	struct vb2_dma_sg_buf *buf = buf_priv;
e078b79d8aa70a4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  210  	struct sg_table *sgt = buf->dma_sgt;
e078b79d8aa70a4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  211  
e078b79d8aa70a4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  212  	/* DMABUF exporter will flush the cache for us */
e078b79d8aa70a4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  213  	if (buf->db_attach)
e078b79d8aa70a4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  214  		return;
d790b7eda953df4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-24  215  
b8bd9d592f68e3c drivers/media/common/videobuf2/videobuf2-dma-sg.c Marek Szyprowski      2020-06-18  216  	dma_sync_sgtable_for_cpu(buf->dev, sgt, buf->dma_dir);
d790b7eda953df4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-24  217  }
d790b7eda953df4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-24  218  
36c0f8b32c4bd4f drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2016-04-15 @219  static void *vb2_dma_sg_get_userptr(struct device *dev, unsigned long vaddr,
cd474037c4a9a9c drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  220  				    unsigned long size,
cd474037c4a9a9c drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  221  				    enum dma_data_direction dma_dir)
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  222  {
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  223  	struct vb2_dma_sg_buf *buf;
d790b7eda953df4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-24  224  	struct sg_table *sgt;
3336c24f25ec932 drivers/media/v4l2-core/videobuf2-dma-sg.c        Jan Kara              2015-07-13  225  	struct frame_vector *vec;
251a79f8f5adfd8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  226  
10791829eb52d57 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2016-07-21  227  	if (WARN_ON(!dev))
10791829eb52d57 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2016-07-21  228  		return ERR_PTR(-EINVAL);
10791829eb52d57 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2016-07-21  229  
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  230  	buf = kzalloc(sizeof *buf, GFP_KERNEL);
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  231  	if (!buf)
0ff657b0f6120cb drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2016-07-21  232  		return ERR_PTR(-ENOMEM);
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  233  
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  234  	buf->vaddr = NULL;
36c0f8b32c4bd4f drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2016-04-15  235  	buf->dev = dev;
cd474037c4a9a9c drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  236  	buf->dma_dir = dma_dir;
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  237  	buf->offset = vaddr & ~PAGE_MASK;
223012475968fb8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02  238  	buf->size = size;
e078b79d8aa70a4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  239  	buf->dma_sgt = &buf->sg_table;
707947247e9517b drivers/media/common/videobuf2/videobuf2-dma-sg.c Hans Verkuil          2019-04-04  240  	vec = vb2_create_framevec(vaddr, size);
3336c24f25ec932 drivers/media/v4l2-core/videobuf2-dma-sg.c        Jan Kara              2015-07-13  241  	if (IS_ERR(vec))
3336c24f25ec932 drivers/media/v4l2-core/videobuf2-dma-sg.c        Jan Kara              2015-07-13  242  		goto userptr_fail_pfnvec;
3336c24f25ec932 drivers/media/v4l2-core/videobuf2-dma-sg.c        Jan Kara              2015-07-13  243  	buf->vec = vec;
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  244  
3336c24f25ec932 drivers/media/v4l2-core/videobuf2-dma-sg.c        Jan Kara              2015-07-13  245  	buf->pages = frame_vector_pages(vec);
3336c24f25ec932 drivers/media/v4l2-core/videobuf2-dma-sg.c        Jan Kara              2015-07-13  246  	if (IS_ERR(buf->pages))
3336c24f25ec932 drivers/media/v4l2-core/videobuf2-dma-sg.c        Jan Kara              2015-07-13  247  		goto userptr_fail_sgtable;
3336c24f25ec932 drivers/media/v4l2-core/videobuf2-dma-sg.c        Jan Kara              2015-07-13  248  	buf->num_pages = frame_vector_count(vec);
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  249  
e078b79d8aa70a4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  250  	if (sg_alloc_table_from_pages(buf->dma_sgt, buf->pages,
223012475968fb8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02  251  			buf->num_pages, buf->offset, size, 0))
3336c24f25ec932 drivers/media/v4l2-core/videobuf2-dma-sg.c        Jan Kara              2015-07-13  252  		goto userptr_fail_sgtable;
223012475968fb8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02  253  
d790b7eda953df4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-24  254  	sgt = &buf->sg_table;
251a79f8f5adfd8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  255  	/*
251a79f8f5adfd8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  256  	 * No need to sync to the device, this will happen later when the
251a79f8f5adfd8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  257  	 * prepare() memop is called.
251a79f8f5adfd8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  258  	 */
b8bd9d592f68e3c drivers/media/common/videobuf2/videobuf2-dma-sg.c Marek Szyprowski      2020-06-18  259  	if (dma_map_sgtable(buf->dev, sgt, buf->dma_dir,
b8bd9d592f68e3c drivers/media/common/videobuf2/videobuf2-dma-sg.c Marek Szyprowski      2020-06-18  260  			    DMA_ATTR_SKIP_CPU_SYNC)) {
d790b7eda953df4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-24  261  		goto userptr_fail_map;
6a5d77cbf26078e drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2015-04-29  262  
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  263  	return buf;
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  264  
d790b7eda953df4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-24  265  userptr_fail_map:
d790b7eda953df4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-24  266  	sg_free_table(&buf->sg_table);
3336c24f25ec932 drivers/media/v4l2-core/videobuf2-dma-sg.c        Jan Kara              2015-07-13  267  userptr_fail_sgtable:
3336c24f25ec932 drivers/media/v4l2-core/videobuf2-dma-sg.c        Jan Kara              2015-07-13  268  	vb2_destroy_framevec(vec);
3336c24f25ec932 drivers/media/v4l2-core/videobuf2-dma-sg.c        Jan Kara              2015-07-13  269  userptr_fail_pfnvec:
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  270  	kfree(buf);
0ff657b0f6120cb drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2016-07-21  271  	return ERR_PTR(-ENOMEM);
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  272  }
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  273  
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  274  /*
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  275   * @put_userptr: inform the allocator that a USERPTR buffer will no longer
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  276   *		 be used
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  277   */
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29 @278  static void vb2_dma_sg_put_userptr(void *buf_priv)
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  279  {
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  280  	struct vb2_dma_sg_buf *buf = buf_priv;
d790b7eda953df4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-24  281  	struct sg_table *sgt = &buf->sg_table;
223012475968fb8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02  282  	int i = buf->num_pages;
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  283  
ffdc78efe1a8a01 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2013-03-02  284  	dprintk(1, "%s: Releasing userspace buffer of %d pages\n",
223012475968fb8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02  285  	       __func__, buf->num_pages);
b8bd9d592f68e3c drivers/media/common/videobuf2/videobuf2-dma-sg.c Marek Szyprowski      2020-06-18  286  	dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  287  	if (buf->vaddr)
223012475968fb8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Ricardo Ribalda       2013-08-02  288  		vm_unmap_ram(buf->vaddr, buf->num_pages);
e078b79d8aa70a4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  289  	sg_free_table(buf->dma_sgt);
5b6f9abe5a49df8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Stanimir Varbanov     2017-08-21  290  	if (buf->dma_dir == DMA_FROM_DEVICE ||
5b6f9abe5a49df8 drivers/media/v4l2-core/videobuf2-dma-sg.c        Stanimir Varbanov     2017-08-21  291  	    buf->dma_dir == DMA_BIDIRECTIONAL)
c0cb76589c77b9a drivers/media/v4l2-core/videobuf2-dma-sg.c        Stanimir Varbanov     2017-08-29  292  		while (--i >= 0)
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  293  			set_page_dirty_lock(buf->pages[i]);
3336c24f25ec932 drivers/media/v4l2-core/videobuf2-dma-sg.c        Jan Kara              2015-07-13  294  	vb2_destroy_framevec(buf->vec);
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  295  	kfree(buf);
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  296  }
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  297  
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29 @298  static void *vb2_dma_sg_vaddr(void *buf_priv)
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  299  {
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  300  	struct vb2_dma_sg_buf *buf = buf_priv;
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  301  
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  302  	BUG_ON(!buf);
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  303  
e078b79d8aa70a4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  304  	if (!buf->vaddr) {
e078b79d8aa70a4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  305  		if (buf->db_attach)
e078b79d8aa70a4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  306  			buf->vaddr = dma_buf_vmap(buf->db_attach->dmabuf);
e078b79d8aa70a4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  307  		else
d4efd79a81abc70 drivers/media/common/videobuf2/videobuf2-dma-sg.c Christoph Hellwig     2020-06-01  308  			buf->vaddr = vm_map_ram(buf->pages, buf->num_pages, -1);
e078b79d8aa70a4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  309  	}
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  310  
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  311  	/* add offset in case userptr is not page-aligned */
e078b79d8aa70a4 drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  312  	return buf->vaddr ? buf->vaddr + buf->offset : NULL;
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  313  }
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  314  
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29 @315  static unsigned int vb2_dma_sg_num_users(void *buf_priv)
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  316  {
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  317  	struct vb2_dma_sg_buf *buf = buf_priv;
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  318  
6c4bb65d0be8f34 drivers/media/v4l2-core/videobuf2-dma-sg.c        Elena Reshetova       2017-03-06  319  	return refcount_read(&buf->refcount);
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  320  }
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  321  
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29 @322  static int vb2_dma_sg_mmap(void *buf_priv, struct vm_area_struct *vma)
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  323  {
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  324  	struct vb2_dma_sg_buf *buf = buf_priv;
a17ae14766935aa drivers/media/common/videobuf2/videobuf2-dma-sg.c Souptick Joarder      2019-05-13  325  	int err;
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  326  
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  327  	if (!buf) {
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  328  		printk(KERN_ERR "No memory to map\n");
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  329  		return -EINVAL;
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  330  	}
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  331  
a17ae14766935aa drivers/media/common/videobuf2/videobuf2-dma-sg.c Souptick Joarder      2019-05-13  332  	err = vm_map_pages(vma, buf->pages, buf->num_pages);
a17ae14766935aa drivers/media/common/videobuf2/videobuf2-dma-sg.c Souptick Joarder      2019-05-13  333  	if (err) {
a17ae14766935aa drivers/media/common/videobuf2/videobuf2-dma-sg.c Souptick Joarder      2019-05-13  334  		printk(KERN_ERR "Remapping memory, error: %d\n", err);
a17ae14766935aa drivers/media/common/videobuf2/videobuf2-dma-sg.c Souptick Joarder      2019-05-13  335  		return err;
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  336  	}
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  337  
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  338  	/*
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  339  	 * Use common vm_area operations to track buffer refcount.
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  340  	 */
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  341  	vma->vm_private_data	= &buf->handler;
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  342  	vma->vm_ops		= &vb2_common_vm_ops;
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  343  
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  344  	vma->vm_ops->open(vma);
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  345  
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  346  	return 0;
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  347  }
5ba3f757f0592ca drivers/media/video/videobuf2-dma-sg.c            Andrzej Pietrasiewicz 2010-11-29  348  
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  349  /*********************************************/
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  350  /*         DMABUF ops for exporters          */
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  351  /*********************************************/
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  352  
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  353  struct vb2_dma_sg_attachment {
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  354  	struct sg_table sgt;
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  355  	enum dma_data_direction dma_dir;
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  356  };
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  357  
a19741e5e5a9f1f drivers/media/common/videobuf2/videobuf2-dma-sg.c Christian König       2018-05-28 @358  static int vb2_dma_sg_dmabuf_ops_attach(struct dma_buf *dbuf,
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  359  	struct dma_buf_attachment *dbuf_attach)
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  360  {
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  361  	struct vb2_dma_sg_attachment *attach;
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  362  	unsigned int i;
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  363  	struct scatterlist *rd, *wr;
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  364  	struct sg_table *sgt;
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  365  	struct vb2_dma_sg_buf *buf = dbuf->priv;
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  366  	int ret;
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  367  
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  368  	attach = kzalloc(sizeof(*attach), GFP_KERNEL);
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  369  	if (!attach)
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  370  		return -ENOMEM;
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  371  
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  372  	sgt = &attach->sgt;
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  373  	/* Copy the buf->base_sgt scatter list to the attachment, as we can't
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  374  	 * map the same scatter list to multiple attachments at the same time.
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  375  	 */
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  376  	ret = sg_alloc_table(sgt, buf->dma_sgt->orig_nents, GFP_KERNEL);
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  377  	if (ret) {
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  378  		kfree(attach);
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  379  		return -ENOMEM;
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  380  	}
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  381  
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  382  	rd = buf->dma_sgt->sgl;
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  383  	wr = sgt->sgl;
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  384  	for (i = 0; i < sgt->orig_nents; ++i) {
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  385  		sg_set_page(wr, sg_page(rd), rd->length, rd->offset);
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  386  		rd = sg_next(rd);
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  387  		wr = sg_next(wr);
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  388  	}
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  389  
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  390  	attach->dma_dir = DMA_NONE;
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  391  	dbuf_attach->priv = attach;
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  392  
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  393  	return 0;
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  394  }
041c7b6ac74ee7a drivers/media/v4l2-core/videobuf2-dma-sg.c        Hans Verkuil          2014-11-18  395  

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

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Re: [PATCH v6 35/36] videobuf2: use sgtable-based scatterlist wrappers

[Robin Murphy]

On 2020-06-18 16:39, Marek Szyprowski wrote:
> Use recently introduced common wrappers operating directly on the struct
> sg_table objects and scatterlist page iterators to make the code a bit
> more compact, robust, easier to follow and copy/paste safe.
> 
> No functional change, because the code already properly did all the
> scaterlist related calls.
> 
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> ---
>   .../common/videobuf2/videobuf2-dma-contig.c   | 41 ++++++++-----------
>   .../media/common/videobuf2/videobuf2-dma-sg.c | 32 ++++++---------
>   .../common/videobuf2/videobuf2-vmalloc.c      | 12 ++----
>   3 files changed, 34 insertions(+), 51 deletions(-)
> 
> diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
> index f4b4a7c135eb..ba01a8692d88 100644
> --- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c
> +++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
> @@ -48,16 +48,15 @@ struct vb2_dc_buf {
>   
>   static unsigned long vb2_dc_get_contiguous_size(struct sg_table *sgt)
>   {
> -	struct scatterlist *s;
>   	dma_addr_t expected = sg_dma_address(sgt->sgl);
> -	unsigned int i;
> +	struct sg_dma_page_iter dma_iter;
>   	unsigned long size = 0;
>   
> -	for_each_sg(sgt->sgl, s, sgt->nents, i) {
> -		if (sg_dma_address(s) != expected)
> +	for_each_sgtable_dma_page(sgt, &dma_iter, 0) {
> +		if (sg_page_iter_dma_address(&dma_iter) != expected)
>   			break;
> -		expected = sg_dma_address(s) + sg_dma_len(s);
> -		size += sg_dma_len(s);
> +		expected += PAGE_SIZE;
> +		size += PAGE_SIZE;

Same comment as for the DRM version. In fact, given that it's the same 
function with the same purpose, might it be worth hoisting out as a 
generic helper for the sg_table API itself?

>   	}
>   	return size;
>   }
[...]
> diff --git a/drivers/media/common/videobuf2/videobuf2-dma-sg.c b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
> index 92072a08af25..6ddf953efa11 100644
> --- a/drivers/media/common/videobuf2/videobuf2-dma-sg.c
> +++ b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
> @@ -142,9 +142,8 @@ static void *vb2_dma_sg_alloc(struct device *dev, unsigned long dma_attrs,
>   	 * No need to sync to the device, this will happen later when the
>   	 * prepare() memop is called.
>   	 */
> -	sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
> -				      buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
> -	if (!sgt->nents)
> +	if (dma_map_sgtable(buf->dev, sgt, buf->dma_dir,
> +			    DMA_ATTR_SKIP_CPU_SYNC)) {

As 0-day's explosions of nonsense imply, there's a rogue bracket here...

>   		goto fail_map;
>   
>   	buf->handler.refcount = &buf->refcount;
> @@ -180,8 +179,8 @@ static void vb2_dma_sg_put(void *buf_priv)
>   	if (refcount_dec_and_test(&buf->refcount)) {
>   		dprintk(1, "%s: Freeing buffer of %d pages\n", __func__,
>   			buf->num_pages);
> -		dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
> -				   buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
> +		dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir,
> +				  DMA_ATTR_SKIP_CPU_SYNC);
>   		if (buf->vaddr)
>   			vm_unmap_ram(buf->vaddr, buf->num_pages);
>   		sg_free_table(buf->dma_sgt);
> @@ -202,8 +201,7 @@ static void vb2_dma_sg_prepare(void *buf_priv)
>   	if (buf->db_attach)
>   		return;
>   
> -	dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->orig_nents,
> -			       buf->dma_dir);
> +	dma_sync_sgtable_for_device(buf->dev, sgt, buf->dma_dir);
>   }
>   
>   static void vb2_dma_sg_finish(void *buf_priv)
> @@ -215,7 +213,7 @@ static void vb2_dma_sg_finish(void *buf_priv)
>   	if (buf->db_attach)
>   		return;
>   
> -	dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir);
> +	dma_sync_sgtable_for_cpu(buf->dev, sgt, buf->dma_dir);
>   }
>   
>   static void *vb2_dma_sg_get_userptr(struct device *dev, unsigned long vaddr,
> @@ -258,9 +256,8 @@ static void *vb2_dma_sg_get_userptr(struct device *dev, unsigned long vaddr,
>   	 * No need to sync to the device, this will happen later when the
>   	 * prepare() memop is called.
>   	 */
> -	sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
> -				      buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
> -	if (!sgt->nents)
> +	if (dma_map_sgtable(buf->dev, sgt, buf->dma_dir,
> +			    DMA_ATTR_SKIP_CPU_SYNC)) {

... and here.

Robin.
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[PATCH v6 36/36] drm: xen: fix common struct sg_table related issues

[Marek Szyprowski]

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

Fix the code to refer to proper nents or orig_nents entries. This driver
reports the number of the pages in the imported scatterlist, so it should
refer to sg_table->orig_nents entry.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
---
 drivers/gpu/drm/xen/xen_drm_front_gem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.c b/drivers/gpu/drm/xen/xen_drm_front_gem.c
index f0b85e094111..ba4bdc5590ea 100644
--- a/drivers/gpu/drm/xen/xen_drm_front_gem.c
+++ b/drivers/gpu/drm/xen/xen_drm_front_gem.c
@@ -215,7 +215,7 @@ xen_drm_front_gem_import_sg_table(struct drm_device *dev,
 		return ERR_PTR(ret);
 
 	DRM_DEBUG("Imported buffer of size %zu with nents %u\n",
-		  size, sgt->nents);
+		  size, sgt->orig_nents);
 
 	return &xen_obj->base;
 }
-- 
2.17.1

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