Exynos GEM objects contains an array of pointers to the pages, which the allocated buffer consists of. Till now the code used some hacks (like relying on DMA-mapping internal structures or using ARM-specific dma_to_pfn helper) to build this array. This patch fixes this by adding proper call to dma_get_sgtable_attrs() and using the acquired scatter-list to construct needed array. This approach is more portable (work also for ARM64) and finally fixes the layering violation that was present in this code.

Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- Patch is based on exynos-drm-next branch.

v2: use drm_prime_sg_to_page_addr_arrays() --- drivers/gpu/drm/exynos/exynos_drm_gem.c | 58 +++++++++++++++++++-------------- 1 file changed, 33 insertions(+), 25 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c b/drivers/gpu/drm/exynos/exynos_drm_gem.c index 29f48756e72f..183aa4a74686 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_gem.c +++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c @@ -25,6 +25,8 @@ static int exynos_drm_alloc_buf(struct exynos_drm_gem *exynos_gem) struct drm_device *dev = exynos_gem->base.dev; enum dma_attr attr; unsigned int nr_pages; + struct sg_table sgt; + int ret = -ENOMEM;

if (exynos_gem->dma_addr) { DRM_DEBUG_KMS("already allocated.\n"); @@ -56,13 +58,10 @@ static int exynos_drm_alloc_buf(struct exynos_drm_gem *exynos_gem)

nr_pages = exynos_gem->size >> PAGE_SHIFT;

- if (!is_drm_iommu_supported(dev)) { - exynos_gem->pages = drm_calloc_large(nr_pages, - sizeof(struct page *)); - if (!exynos_gem->pages) { - DRM_ERROR("failed to allocate pages.\n"); - return -ENOMEM; - } + exynos_gem->pages = drm_calloc_large(nr_pages, sizeof(struct page *)); + if (!exynos_gem->pages) { + DRM_ERROR("failed to allocate pages.\n"); + return -ENOMEM; }

exynos_gem->cookie = dma_alloc_attrs(dev->dev, exynos_gem->size, @@ -70,30 +69,40 @@ static int exynos_drm_alloc_buf(struct exynos_drm_gem *exynos_gem) &exynos_gem->dma_attrs); if (!exynos_gem->cookie) { DRM_ERROR("failed to allocate buffer.\n"); - if (exynos_gem->pages) - drm_free_large(exynos_gem->pages); - return -ENOMEM; + goto err_free; }

- if (exynos_gem->pages) { - dma_addr_t start_addr; - unsigned int i = 0; - - start_addr = exynos_gem->dma_addr; - while (i < nr_pages) { - exynos_gem->pages[i] = - pfn_to_page(dma_to_pfn(dev->dev, start_addr)); - start_addr += PAGE_SIZE; - i++; - } - } else { - exynos_gem->pages = exynos_gem->cookie; + ret = dma_get_sgtable_attrs(dev->dev, &sgt, exynos_gem->cookie, + exynos_gem->dma_addr, exynos_gem->size, + &exynos_gem->dma_attrs); + if (ret < 0) { + DRM_ERROR("failed to get sgtable.\n"); + goto err_dma_free; + } + + if (drm_prime_sg_to_page_addr_arrays(&sgt, exynos_gem->pages, NULL, + nr_pages)) { + DRM_ERROR("invalid sgtable.\n"); + ret = -EINVAL; + goto err_sgt_free; }

+ sg_free_table(&sgt); + DRM_DEBUG_KMS("dma_addr(0x%lx), size(0x%lx)\n", (unsigned long)exynos_gem->dma_addr, exynos_gem->size);

return 0; + +err_sgt_free: + sg_free_table(&sgt); +err_dma_free: + dma_free_attrs(dev->dev, exynos_gem->size, exynos_gem->cookie, + exynos_gem->dma_addr, &exynos_gem->dma_attrs); +err_free: + drm_free_large(exynos_gem->pages); + + return ret; }

static void exynos_drm_free_buf(struct exynos_drm_gem *exynos_gem) @@ -112,8 +121,7 @@ static void exynos_drm_free_buf(struct exynos_drm_gem *exynos_gem) (dma_addr_t)exynos_gem->dma_addr, &exynos_gem->dma_attrs);

- if (!is_drm_iommu_supported(dev)) - drm_free_large(exynos_gem->pages); + drm_free_large(exynos_gem->pages); }

static int exynos_drm_gem_handle_create(struct drm_gem_object *obj,