diff options
author | Marek Szyprowski <m.szyprowski@samsung.com> | 2020-06-19 12:36:04 +0200 |
---|---|---|
committer | Christian König <christian.koenig@amd.com> | 2020-07-13 10:47:26 +0200 |
commit | 39913934e67cab214480cc95a3632696aeb8e71a (patch) | |
tree | 25657913c7576678174eed382d629f677a704899 /drivers | |
parent | de48984486d942d4f23e2b29374639f21042bdaa (diff) |
drm: amdgpu: fix common struct sg_table related issues
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>
Link: https://patchwork.freedesktop.org/patch/371142/
Signed-off-by: Christian König <christian.koenig@amd.com>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c | 6 | ||||
-rw-r--r-- | drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 9 | ||||
-rw-r--r-- | 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 38d2a7fb5698..4223c56188fe 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c @@ -1043,7 +1043,6 @@ 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); @@ -1058,9 +1057,8 @@ 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 */ @@ -1091,8 +1089,7 @@ 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 ad5732f8d4d2..d4f626d9bec1 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c @@ -476,11 +476,11 @@ 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; @@ -500,7 +500,7 @@ 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; @@ -531,7 +531,7 @@ 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); |