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 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 dma-mapping wrappers, which operate directly on the sg_table objects.
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-20200504.
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
Changelog:
v3: - introduce dma_*_sgtable_* wrappers and use them in all patches
v2: https://lore.kernel.org/linux-iommu/c01c9766-9778-fd1f-f36e-2dc7bd376ba4@arm... - 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... - initial version
Patch summary:
Marek Szyprowski (25): dma-mapping: add generic helpers for mapping sgtable objects 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: 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: msm: 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: fix common struct sg_table related issues drm: tegra: 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: 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
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/armada/armada_gem.c | 10 ++++---- drivers/gpu/drm/drm_cache.c | 2 +- drivers/gpu/drm/drm_gem_shmem_helper.c | 14 +++++++---- drivers/gpu/drm/drm_prime.c | 13 +++++----- drivers/gpu/drm/etnaviv/etnaviv_gem.c | 12 ++++----- drivers/gpu/drm/exynos/exynos_drm_g2d.c | 9 +++---- drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c | 13 ++++------ drivers/gpu/drm/i915/gem/selftests/mock_dmabuf.c | 7 +++--- drivers/gpu/drm/lima/lima_gem.c | 11 +++++--- drivers/gpu/drm/msm/msm_gem.c | 13 ++++------ drivers/gpu/drm/msm/msm_iommu.c | 2 +- drivers/gpu/drm/panfrost/panfrost_gem.c | 4 +-- drivers/gpu/drm/panfrost/panfrost_mmu.c | 5 ++-- drivers/gpu/drm/radeon/radeon_ttm.c | 11 ++++---- drivers/gpu/drm/rockchip/rockchip_drm_gem.c | 26 +++++++++---------- drivers/gpu/drm/tegra/gem.c | 27 ++++++++------------ drivers/gpu/drm/tegra/plane.c | 15 ++++------- drivers/gpu/drm/virtio/virtgpu_object.c | 17 ++++++------- drivers/gpu/drm/virtio/virtgpu_vq.c | 10 +++----- drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c | 17 +++---------- drivers/gpu/host1x/job.c | 22 ++++++---------- 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 | 9 ++++--- 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_heap.c | 6 ++--- drivers/staging/android/ion/ion_system_heap.c | 2 +- drivers/staging/media/tegra-vde/iommu.c | 4 +-- drivers/xen/gntdev-dmabuf.c | 7 +++--- include/linux/dma-mapping.h | 32 ++++++++++++++++++++++++ include/linux/iommu.h | 6 +++++ samples/vfio-mdev/mbochs.c | 3 ++- 40 files changed, 202 insertions(+), 207 deletions(-)
struct sg_table is a common structure used for describing a memory buffer. 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 pages (nents entry).
It turned out that it was a common mistake to misuse nents and orig_nents entries, call 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 introduce a common wrappers operating directly on the struct sg_table objects, which take care of the proper use of the nents and orig_nents entries.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- include/linux/dma-mapping.h | 32 ++++++++++++++++++++++++++++++++ include/linux/iommu.h | 6 ++++++ 2 files changed, 38 insertions(+)
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index b43116a..8364c20d 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -609,6 +609,36 @@ static inline void dma_sync_single_range_for_device(struct device *dev, return dma_sync_single_for_device(dev, addr + offset, size, dir); }
+static inline int dma_map_sgtable_attrs(struct device *dev, + struct sg_table *sgt, enum dma_data_direction dir, unsigned long attrs) +{ + int n = dma_map_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs); + + if (n > 0) { + sgt->nents = n; + return 0; + } + return -EINVAL; +} + +static inline void dma_unmap_sgtable_attrs(struct device *dev, + struct sg_table *sgt, enum dma_data_direction dir, unsigned long attrs) +{ + dma_unmap_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs); +} + +static inline void dma_sync_sgtable_for_cpu(struct device *dev, + struct sg_table *sgt, enum dma_data_direction dir) +{ + dma_sync_sg_for_cpu(dev, sgt->sgl, sgt->orig_nents, dir); +} + +static inline void dma_sync_sgtable_for_device(struct device *dev, + struct sg_table *sgt, enum dma_data_direction dir) +{ + dma_sync_sg_for_device(dev, sgt->sgl, sgt->orig_nents, dir); +} + #define dma_map_single(d, a, s, r) dma_map_single_attrs(d, a, s, r, 0) #define dma_unmap_single(d, a, s, r) dma_unmap_single_attrs(d, a, s, r, 0) #define dma_map_sg(d, s, n, r) dma_map_sg_attrs(d, s, n, r, 0) @@ -617,6 +647,8 @@ static inline void dma_sync_single_range_for_device(struct device *dev, #define dma_unmap_page(d, a, s, r) dma_unmap_page_attrs(d, a, s, r, 0) #define dma_get_sgtable(d, t, v, h, s) dma_get_sgtable_attrs(d, t, v, h, s, 0) #define dma_mmap_coherent(d, v, c, h, s) dma_mmap_attrs(d, v, c, h, s, 0) +#define dma_map_sgtable(d, s, r) dma_map_sgtable_attrs(d, s, r, 0) +#define dma_unmap_sgtable(d, s, r) dma_unmap_sgtable_attrs(d, s, r, 0)
extern int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, void *cpu_addr, dma_addr_t dma_addr, size_t size, diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 7ef8b0b..5106b65 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -466,6 +466,12 @@ extern size_t iommu_map_sg_atomic(struct iommu_domain *domain, extern void iommu_set_fault_handler(struct iommu_domain *domain, iommu_fault_handler_t handler, void *token);
+static inline size_t iommu_map_sgtable(struct iommu_domain *domain, + unsigned long iova, struct sg_table *sgt, int prot) +{ + return iommu_map_sg(domain, iova, sgt->sgl, sgt->orig_nents, prot); +} + extern void iommu_get_resv_regions(struct device *dev, struct list_head *list); extern void iommu_put_resv_regions(struct device *dev, struct list_head *list); extern void generic_iommu_put_resv_regions(struct device *dev,
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 the 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. A common mistake was to ignore a result of the dma_map_sg function and don't use the sg_table->orig_nents at all.
To avoid such issues, lets use common dma-mapping wrappers operating directly on the struct sg_table objects and adjust references to the nents and orig_nents respectively.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187 --- drivers/gpu/drm/drm_cache.c | 2 +- drivers/gpu/drm/drm_gem_shmem_helper.c | 14 +++++++++----- drivers/gpu/drm/drm_prime.c | 13 +++++++------ 3 files changed, 17 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/drm_cache.c b/drivers/gpu/drm/drm_cache.c index 03e01b0..63bd497 100644 --- a/drivers/gpu/drm/drm_cache.c +++ b/drivers/gpu/drm/drm_cache.c @@ -127,7 +127,7 @@ static void drm_cache_flush_clflush(struct page *pages[], 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_sg_page(st->sgl, &sg_iter, st->orig_nents, 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 df31e57..cfcfc0d 100644 --- a/drivers/gpu/drm/drm_gem_shmem_helper.c +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c @@ -117,8 +117,8 @@ void drm_gem_shmem_free_object(struct drm_gem_object *obj) kvfree(shmem->pages); } 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); sg_free_table(shmem->sgt); kfree(shmem->sgt); } @@ -395,8 +395,7 @@ 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); sg_free_table(shmem->sgt); kfree(shmem->sgt); shmem->sgt = NULL; @@ -623,12 +622,17 @@ 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); + 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 282774e..3e7cb02 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_attrs(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_attrs(attach->dev, sgt, dir, DMA_ATTR_SKIP_CPU_SYNC); sg_free_table(sgt); kfree(sgt); } @@ -975,7 +976,7 @@ int drm_prime_sg_to_page_addr_arrays(struct sg_table *sgt, struct page **pages, */ page_index = 0; dma_index = 0; - for_each_sg(sgt->sgl, sg, sgt->nents, count) { + for_each_sg(sgt->sgl, sg, sgt->orig_nents, count) { page_len = sg->length; page = sg_page(sg); dma_len = sg_dma_len(sg);
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 the 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. A common mistake was to ignore a result of the dma_map_sg function and don't use the sg_table->orig_nents at all.
To avoid such issues, lets use common dma-mapping wrappers operating directly on the struct sg_table objects and adjust references to the nents and orig_nents respectively.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187 --- drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c | 6 +++--- drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 9 +++------ 2 files changed, 6 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c index 43d8ed7..eca5628 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_attrs(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); 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 eff1f73..f71f97f 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); + 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); sg_free_table(ttm->sg);
#if IS_ENABLED(CONFIG_DRM_AMDGPU_USERPTR)
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 the 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. A common mistake was to ignore a result of the dma_map_sg function and don't use the sg_table->orig_nents at all.
To avoid such issues, lets use common dma-mapping wrappers operating directly on the struct sg_table objects and adjust references to the nents and orig_nents respectively.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187 --- drivers/gpu/drm/armada/armada_gem.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/armada/armada_gem.c b/drivers/gpu/drm/armada/armada_gem.c index 976685f..5b4f48c 100644 --- a/drivers/gpu/drm/armada/armada_gem.c +++ b/drivers/gpu/drm/armada/armada_gem.c @@ -407,8 +407,8 @@ int armada_gem_pwrite_ioctl(struct drm_device *dev, void *data, 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)) { + num = count; goto release; } } else if (dobj->page) { @@ -418,7 +418,7 @@ int armada_gem_pwrite_ioctl(struct drm_device *dev, void *data,
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)) 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);
if (dobj->obj.filp) { struct scatterlist *sg; - for_each_sg(sgt->sgl, sg, sgt->nents, i) + for_each_sg(sgt->sgl, sg, sgt->orig_nents, i) put_page(sg_page(sg)); }
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 the 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. A common mistake was to ignore a result of the dma_map_sg function and don't use the sg_table->orig_nents at all.
To avoid such issues, lets use common dma-mapping wrappers operating directly on the struct sg_table objects and adjust references to the nents and orig_nents respectively.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187 --- drivers/gpu/drm/etnaviv/etnaviv_gem.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c b/drivers/gpu/drm/etnaviv/etnaviv_gem.c index dc9ef30..340026b 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); }
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); }
/* 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; }
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 the 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. A common mistake was to ignore a result of the dma_map_sg function and don't use the sg_table->orig_nents at all.
To avoid such issues, lets use common dma-mapping wrappers operating directly on the struct sg_table objects and adjust references to the nents and orig_nents respectively.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187 --- drivers/gpu/drm/exynos/exynos_drm_g2d.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/exynos/exynos_drm_g2d.c b/drivers/gpu/drm/exynos/exynos_drm_g2d.c index fcee33a..6a655d3 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);
pages = frame_vector_pages(g2d_userptr->vec); if (!IS_ERR(pages)) { @@ -511,10 +511,9 @@ 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); + if (ret) { DRM_DEV_ERROR(g2d->dev, "failed to map sgt with dma region.\n"); - ret = -ENOMEM; goto err_sg_free_table; }
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 the 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.
This 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. The sg_table->orig_nents is (mis)used to properly free the (over)allocated scatterlist.
This patch only introduces 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 --- For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187 --- drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c | 13 +++++-------- drivers/gpu/drm/i915/gem/selftests/mock_dmabuf.c | 7 +++---- 2 files changed, 8 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 7db5a79..7e8583e 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c @@ -48,12 +48,10 @@ 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_attrs(attachment->dev, st, dir, + DMA_ATTR_SKIP_CPU_SYNC); + if (ret) goto err_free_sg; - }
return st;
@@ -73,9 +71,8 @@ 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_attrs(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 debaf7b..756cb76 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); + 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); sg_free_table(st); kfree(st); }
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 the 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. A common mistake was to ignore a result of the dma_map_sg function and don't use the sg_table->orig_nents at all.
To avoid such issues, lets use common dma-mapping wrappers operating directly on the struct sg_table objects and adjust references to the nents and orig_nents respectively.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187 --- drivers/gpu/drm/lima/lima_gem.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/lima/lima_gem.c b/drivers/gpu/drm/lima/lima_gem.c index 5404e0d..fca359d 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); 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); + if (ret) { + sg_free_table(&sgt); + kfree(bo->base.sgt); + bo->base.sgt = NULL; + return ret; + }
*bo->base.sgt = sgt;
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 the 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. A common mistake was to ignore a result of the dma_map_sg function and don't use the sg_table->orig_nents at all.
To avoid such issues, lets use common dma-mapping wrappers operating directly on the struct sg_table objects and adjust references to the nents and orig_nents respectively.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187 --- drivers/gpu/drm/msm/msm_gem.c | 13 +++++-------- drivers/gpu/drm/msm/msm_iommu.c | 2 +- 2 files changed, 6 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c index 5a6a79f..ab952d6 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); } }
@@ -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); } }
diff --git a/drivers/gpu/drm/msm/msm_iommu.c b/drivers/gpu/drm/msm/msm_iommu.c index ad58cfe..d322b39 100644 --- a/drivers/gpu/drm/msm/msm_iommu.c +++ b/drivers/gpu/drm/msm/msm_iommu.c @@ -43,7 +43,7 @@ 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;
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 the 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. A common mistake was to ignore a result of the dma_map_sg function and don't use the sg_table->orig_nents at all.
To avoid such issues, lets use common dma-mapping wrappers operating directly on the struct sg_table objects and adjust references to the nents and orig_nents respectively.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187 --- drivers/gpu/drm/panfrost/panfrost_gem.c | 4 ++-- drivers/gpu/drm/panfrost/panfrost_mmu.c | 5 ++--- 2 files changed, 4 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c index 17b654e..95d7e80 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); 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 ed28aeb..9926111 100644 --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c @@ -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); + if (ret) goto err_map; - }
mmu_map_sg(pfdev, bomapping->mmu, addr, IOMMU_WRITE | IOMMU_READ | IOMMU_NOEXEC, sgt);
On 05/05/2020 09:45, Marek Szyprowski wrote:
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 the 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. A common mistake was to ignore a result of the dma_map_sg function and don't use the sg_table->orig_nents at all.
To avoid such issues, lets use common dma-mapping wrappers operating directly on the struct sg_table objects and adjust references to the nents and orig_nents respectively.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com
The change looks good to me:
Reviewed-by: Steven Price steven.price@arm.com
Although I would have appreciated the commit message being modified to match the specifics of Panfrost - the return of dma_mpa_sg() wasn't being ignored, but the use of orig_nents/nents was indeed wrong.
Steve
For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187
drivers/gpu/drm/panfrost/panfrost_gem.c | 4 ++-- drivers/gpu/drm/panfrost/panfrost_mmu.c | 5 ++--- 2 files changed, 4 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c index 17b654e..95d7e80 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); 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 ed28aeb..9926111 100644 --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c @@ -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);
- if (ret) goto err_map;
}
mmu_map_sg(pfdev, bomapping->mmu, addr, IOMMU_WRITE | IOMMU_READ | IOMMU_NOEXEC, sgt);
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 the 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. A common mistake was to ignore a result of the dma_map_sg function and don't use the sg_table->orig_nents at all.
To avoid such issues, lets use common dma-mapping wrappers operating directly on the struct sg_table objects and adjust references to the nents and orig_nents respectively.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187 --- 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 5d50c9e..166f84e 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); + 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);
- for_each_sg_page(ttm->sg->sgl, &sg_iter, ttm->sg->nents, 0) { + for_each_sg_page(ttm->sg->sgl, &sg_iter, ttm->sg->orig_nents, 0) { struct page *page = sg_page_iter_page(&sg_iter); if (!(gtt->userflags & RADEON_GEM_USERPTR_READONLY)) set_page_dirty(page);
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 the 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. A common mistake was to ignore a result of the dma_map_sg function and don't use the sg_table->orig_nents at all.
To avoid such issues, lets use common dma-mapping wrappers operating directly on the struct sg_table objects and adjust references to the nents and orig_nents respectively.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187 --- drivers/gpu/drm/rockchip/rockchip_drm_gem.c | 26 ++++++++++++-------------- 1 file changed, 12 insertions(+), 14 deletions(-)
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c index 0d18846..9df7d7d 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_sg(rk_obj->sgt->sgl, s, rk_obj->sgt->orig_nents, 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); } drm_prime_gem_destroy(obj, rk_obj->sgt); } else { @@ -493,15 +492,14 @@ static unsigned long rockchip_sg_get_contiguous_size(struct sg_table *sgt, 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); + if (err) + return err;
- if (rockchip_sg_get_contiguous_size(sg, count) < attach->dmabuf->size) { + if (rockchip_sg_get_contiguous_size(sg, sg->nents) < + 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); return -EINVAL; }
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 the 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. A common mistake was to ignore a result of the dma_map_sg function and don't use the sg_table->orig_nents at all.
To avoid such issues, lets use common dma-mapping wrappers operating directly on the struct sg_table objects and adjust references to the nents and orig_nents respectively.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187 --- 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 6237681..4554fbb 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); 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); + if (err) goto free_sgt; - }
return 0;
@@ -571,7 +566,7 @@ int tegra_drm_mmap(struct file *file, struct vm_area_struct *vma) goto free; }
- if (dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir) == 0) + if (dma_map_sgtable(attach->dev, sgt, dir)) 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);
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 9ccfb56..4b1c2ae6 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); + 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);
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);
host1x_bo_unpin(dc->dev, &bo->base, sgt); state->iova[i] = DMA_MAPPING_ERROR;
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 the 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. A common mistake was to ignore a result of the dma_map_sg function and don't use the sg_table->orig_nents at all.
To avoid such issues, lets use common dma-mapping wrappers operating directly on the struct sg_table objects and adjust references to the nents and orig_nents respectively.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187 --- drivers/gpu/drm/virtio/virtgpu_object.c | 17 ++++++++--------- drivers/gpu/drm/virtio/virtgpu_vq.c | 10 ++++------ 2 files changed, 12 insertions(+), 15 deletions(-)
diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c b/drivers/gpu/drm/virtio/virtgpu_object.c index 6ccbd01..5fe153c 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); 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); + 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), diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c index 9e663a5..c329147 100644 --- a/drivers/gpu/drm/virtio/virtgpu_vq.c +++ b/drivers/gpu/drm/virtio/virtgpu_vq.c @@ -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));
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 the 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. A common mistake was to ignore a result of the dma_map_sg function and don't use the sg_table->orig_nents at all.
To avoid such issues, lets use common dma-mapping wrappers operating directly on the struct sg_table objects and adjust references to the nents and orig_nents respectively.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187 --- 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 bf0bc46..e50ae8b 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); 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); }
/** @@ -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;
I'm not exactly an expert on this, but looks alright to me. Acked-by: Roland Scheidegger sroland@vmware.com
Am 05.05.20 um 10:46 schrieb 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 the 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. A common mistake was to ignore a result of the dma_map_sg function and don't use the sg_table->orig_nents at all.
To avoid such issues, lets use common dma-mapping wrappers operating directly on the struct sg_table objects and adjust references to the nents and orig_nents respectively.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com
For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187
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 bf0bc46..e50ae8b 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); 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);
}
/** @@ -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;
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 the 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. A common mistake was to ignore a result of the dma_map_sg function and don't use the sg_table->orig_nents at all.
To avoid such issues, lets use common dma-mapping wrappers operating directly on the struct sg_table objects and adjust references to the nents and orig_nents respectively.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187 --- drivers/xen/gntdev-dmabuf.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/drivers/xen/gntdev-dmabuf.c b/drivers/xen/gntdev-dmabuf.c index 75d3bb9..4b22785 100644 --- a/drivers/xen/gntdev-dmabuf.c +++ b/drivers/xen/gntdev-dmabuf.c @@ -247,8 +247,7 @@ 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, + dma_unmap_sgtable_attrs(attach->dev, sgt, gntdev_dmabuf_attach->dir, DMA_ATTR_SKIP_CPU_SYNC); sg_free_table(sgt); @@ -288,7 +287,7 @@ static void dmabuf_exp_ops_detach(struct dma_buf *dma_buf, 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, + if (dma_map_sgtable_attrs(attach->dev, sgt, dir, DMA_ATTR_SKIP_CPU_SYNC)) { sg_free_table(sgt); kfree(sgt); @@ -625,7 +624,7 @@ static struct gntdev_dmabuf *dmabuf_imp_alloc_storage(int count)
/* 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_sg_page(sgt->sgl, &sg_iter, sgt->orig_nents, 0) { struct page *page = sg_page_iter_page(&sg_iter); /* * Check if page is valid: this can happen if we are given
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 the 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. A common mistake was to ignore a result of the dma_map_sg function and don't use the sg_table->orig_nents at all.
To avoid such issues, lets use common dma-mapping wrappers operating directly on the struct sg_table objects and adjust references to the nents and orig_nents respectively.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187 --- 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 a10643a..850115e 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); + 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_sg(sgt->sgl, sg, sgt->orig_nents, 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); + 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);
host1x_bo_unpin(dev, unpin->bo, sgt); host1x_bo_put(unpin->bo);
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 the 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. A common mistake was to ignore a result of the dma_map_sg function and don't use the sg_table->orig_nents at all.
To avoid such issues, lets use common dma-mapping wrappers operating directly on the struct sg_table objects and adjust references to the nents and orig_nents respectively.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187 --- drivers/media/platform/vsp1/vsp1_drm.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/media/platform/vsp1/vsp1_drm.c b/drivers/media/platform/vsp1/vsp1_drm.c index a4a45d6..8a2624b 100644 --- a/drivers/media/platform/vsp1/vsp1_drm.c +++ b/drivers/media/platform/vsp1/vsp1_drm.c @@ -912,8 +912,9 @@ 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_attrs(vsp1->bus_master, sgt, DMA_TO_DEVICE, + DMA_ATTR_SKIP_CPU_SYNC); + return sgt->nents; } EXPORT_SYMBOL_GPL(vsp1_du_map_sg);
@@ -921,8 +922,8 @@ 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_attrs(vsp1->bus_master, sgt, DMA_TO_DEVICE, + DMA_ATTR_SKIP_CPU_SYNC); } EXPORT_SYMBOL_GPL(vsp1_du_unmap_sg);
Hi Marek,
On Tue, May 5, 2020 at 10:48 AM Marek Szyprowski m.szyprowski@samsung.com wrote:
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 the 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. A common mistake was to ignore a result of the dma_map_sg function and don't use the sg_table->orig_nents at all.
To avoid such issues, lets use common dma-mapping wrappers operating directly on the struct sg_table objects and adjust references to the nents and orig_nents respectively.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com
For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187
For the modern lore-users: https://lore.kernel.org/r/20200505083926.28503-1-m.szyprowski@samsung.com/
Gr{oetje,eeting}s,
Geert
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 the 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. A common mistake was to ignore a result of the dma_map_sg function and don't use the sg_table->orig_nents at all.
To avoid such issues, lets use common dma-mapping wrappers operating directly on the struct sg_table objects and adjust references to the nents and orig_nents respectively.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187 --- 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 9f964ca..be9523a 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); + 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); }
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 acb26c6..5bcbf7a 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); + 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); sg_free_table(sg); kfree(sg); }
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 the 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. A common mistake was to ignore a result of the dma_map_sg function and don't use the sg_table->orig_nents at all.
To avoid such issues, lets use common dma-mapping wrappers operating directly on the struct sg_table objects and adjust references to the nents and orig_nents respectively.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187 --- drivers/staging/android/ion/ion.c | 25 +++++++++++-------------- drivers/staging/android/ion/ion_heap.c | 6 +++--- drivers/staging/android/ion/ion_system_heap.c | 2 +- 3 files changed, 15 insertions(+), 18 deletions(-)
diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c index 38b51ea..9274298 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_sg(table->sgl, sg, table->orig_nents, 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); + 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); }
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 0755b11..f2f7ca7 100644 --- a/drivers/staging/android/ion/ion_heap.c +++ b/drivers/staging/android/ion/ion_heap.c @@ -38,7 +38,7 @@ void *ion_heap_map_kernel(struct ion_heap *heap, else pgprot = pgprot_writecombine(PAGE_KERNEL);
- for_each_sg(table->sgl, sg, table->nents, i) { + for_each_sg(table->sgl, sg, table->orig_nents, i) { int npages_this_entry = PAGE_ALIGN(sg->length) / PAGE_SIZE; struct page *page = sg_page(sg);
@@ -71,7 +71,7 @@ int ion_heap_map_user(struct ion_heap *heap, struct ion_buffer *buffer, int i; int ret;
- for_each_sg(table->sgl, sg, table->nents, i) { + for_each_sg(table->sgl, sg, table->orig_nents, i) { struct page *page = sg_page(sg); unsigned long remainder = vma->vm_end - addr; unsigned long len = sg->length; @@ -142,7 +142,7 @@ 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->sgl, table->orig_nents, pgprot); }
int ion_heap_pages_zero(struct page *page, size_t size, pgprot_t pgprot) diff --git a/drivers/staging/android/ion/ion_system_heap.c b/drivers/staging/android/ion/ion_system_heap.c index b83a1d1..34f6e81 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_sg(table->sgl, sg, table->orig_nents, i) free_buffer_page(sys_heap, buffer, sg_page(sg)); sg_free_table(table); kfree(table);
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 the 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. A common mistake was to ignore a result of the dma_map_sg function and don't use the sg_table->orig_nents at all.
To avoid such issues, lets use common dma-mapping wrappers operating directly on the struct sg_table objects and adjust references to the nents and orig_nents respectively.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187 --- 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 6af863d..adf8dc7 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;
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 the 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. A common mistake was to ignore a result of the dma_map_sg function and don't use the sg_table->orig_nents at all.
To avoid such issues, lets use common dma-mapping wrappers operating directly on the struct sg_table objects and adjust references to the nents and orig_nents respectively.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187 --- 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 e3e085e..0a3e02aa 100644 --- a/drivers/misc/fastrpc.c +++ b/drivers/misc/fastrpc.c @@ -518,7 +518,7 @@ static struct fastrpc_invoke_ctx *fastrpc_context_alloc(
table = &a->sgt;
- if (!dma_map_sg(attachment->dev, table->sgl, table->nents, dir)) + if (!dma_map_sgtable(attachment->dev, table, dir)) 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); }
static void fastrpc_release(struct dma_buf *dmabuf)
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 the 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. A common mistake was to ignore a result of the dma_map_sg function and don't use the sg_table->orig_nents at all.
To avoid such issues, lets use common dma-mapping wrappers operating directly on the struct sg_table objects and adjust references to the nents and orig_nents respectively.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187 --- 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 4029637..df7dba8 100644 --- a/drivers/rapidio/devices/rio_mport_cdev.c +++ b/drivers/rapidio/devices/rio_mport_cdev.c @@ -574,8 +574,7 @@ static void dma_req_free(struct kref *ref) struct mport_cdev_priv *priv = req->priv; unsigned int i;
- 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); sg_free_table(&req->sgt); if (req->page_list) { for (i = 0; i < req->nr_pages; i++) @@ -927,9 +926,8 @@ static int do_dma_request(struct mport_dma_req *req, 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); + if (ret) { rmcd_error("Failed to map SG list"); ret = -EFAULT; goto err_pg;
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 the 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. A common mistake was to ignore a result of the dma_map_sg function and don't use the sg_table->orig_nents at all.
To avoid such issues, lets use common dma-mapping wrappers operating directly on the struct sg_table objects and adjust references to the nents and orig_nents respectively.
While touching this code, also add missing call to dma_unmap_sgtable.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187 --- 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 3cc5e59..f2c62e0 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)) 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); sg_free_table(sg); kfree(sg); }
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 --- For more information, see '[PATCH v3 00/25] DRM: fix struct sg_table nents vs. orig_nents misuse' thread: https://lkml.org/lkml/2020/5/5/187 --- 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 df44ed7..3f366e4 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 3016164..c40304d 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 7d7acee..3c6fe6c 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 544ca57..398c47f 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; }
Hi Marek,
On 05/05/2020 10:45, Marek Szyprowski wrote:
struct sg_table is a common structure used for describing a memory buffer. 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 pages (nents entry).
It turned out that it was a common mistake to misuse nents and orig_nents entries, call 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 introduce a common wrappers operating directly on the struct sg_table objects, which take care of the proper use of the nents and orig_nents entries.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com
include/linux/dma-mapping.h | 32 ++++++++++++++++++++++++++++++++ include/linux/iommu.h | 6 ++++++ 2 files changed, 38 insertions(+)
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index b43116a..8364c20d 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -609,6 +609,36 @@ static inline void dma_sync_single_range_for_device(struct device *dev, return dma_sync_single_for_device(dev, addr + offset, size, dir); }
+static inline int dma_map_sgtable_attrs(struct device *dev,
- struct sg_table *sgt, enum dma_data_direction dir, unsigned long attrs)
Please document these new inline functions!
The core reason IMHO why so many drivers do this wrong is that the struct sg_table documentation is very poor. In particular w.r.t. how the nents and orig_nents fields should be used.
It confused me, and clearly I am not alone in that.
So while this is a very nice improvement, it doesn't address the core issue, i.e. the documentation.
Especially some examples on how to use these new functions would be welcome.
Regards,
Hans
+{
- int n = dma_map_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs);
- if (n > 0) {
sgt->nents = n;return 0;- }
- return -EINVAL;
+}
+static inline void dma_unmap_sgtable_attrs(struct device *dev,
- struct sg_table *sgt, enum dma_data_direction dir, unsigned long attrs)
+{
- dma_unmap_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs);
+}
+static inline void dma_sync_sgtable_for_cpu(struct device *dev,
- struct sg_table *sgt, enum dma_data_direction dir)
+{
- dma_sync_sg_for_cpu(dev, sgt->sgl, sgt->orig_nents, dir);
+}
+static inline void dma_sync_sgtable_for_device(struct device *dev,
- struct sg_table *sgt, enum dma_data_direction dir)
+{
- dma_sync_sg_for_device(dev, sgt->sgl, sgt->orig_nents, dir);
+}
#define dma_map_single(d, a, s, r) dma_map_single_attrs(d, a, s, r, 0) #define dma_unmap_single(d, a, s, r) dma_unmap_single_attrs(d, a, s, r, 0) #define dma_map_sg(d, s, n, r) dma_map_sg_attrs(d, s, n, r, 0) @@ -617,6 +647,8 @@ static inline void dma_sync_single_range_for_device(struct device *dev, #define dma_unmap_page(d, a, s, r) dma_unmap_page_attrs(d, a, s, r, 0) #define dma_get_sgtable(d, t, v, h, s) dma_get_sgtable_attrs(d, t, v, h, s, 0) #define dma_mmap_coherent(d, v, c, h, s) dma_mmap_attrs(d, v, c, h, s, 0) +#define dma_map_sgtable(d, s, r) dma_map_sgtable_attrs(d, s, r, 0) +#define dma_unmap_sgtable(d, s, r) dma_unmap_sgtable_attrs(d, s, r, 0)
extern int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, void *cpu_addr, dma_addr_t dma_addr, size_t size, diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 7ef8b0b..5106b65 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -466,6 +466,12 @@ extern size_t iommu_map_sg_atomic(struct iommu_domain *domain, extern void iommu_set_fault_handler(struct iommu_domain *domain, iommu_fault_handler_t handler, void *token);
+static inline size_t iommu_map_sgtable(struct iommu_domain *domain,
unsigned long iova, struct sg_table *sgt, int prot)+{
- return iommu_map_sg(domain, iova, sgt->sgl, sgt->orig_nents, prot);
+}
extern void iommu_get_resv_regions(struct device *dev, struct list_head *list); extern void iommu_put_resv_regions(struct device *dev, struct list_head *list); extern void generic_iommu_put_resv_regions(struct device *dev,
dri-devel@lists.freedesktop.org
-
Geert Uytterhoeven -
Hans Verkuil -
Marek Szyprowski -
Roland Scheidegger -
Steven Price