drm/exynos/gem: remove DMA-mapping hacks used for constructing page array
authorMarek Szyprowski <m.szyprowski@samsung.com>
Tue, 13 Oct 2015 11:47:20 +0000 (13:47 +0200)
committerInki Dae <inki.dae@samsung.com>
Tue, 3 Nov 2015 02:46:39 +0000 (11:46 +0900)
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>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
drivers/gpu/drm/exynos/exynos_drm_gem.c

index f1dcdd086886d2fd6dc29bf73a0c54bd1a057030..252eb301470ce576df2daf0cd01b7942172da51b 100644 (file)
@@ -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,