shmem_read_mapping_page_gfp() first tries to allocate pages from page cache so if pages are allocated from page cache then these pages could have valid cache line. after that cpu may read garbage data from cache once gpu operation is completed with allocated pages. so with this patch, Non-contiguous memory allocation request allocates pages from highmem through alloc_page() with GFP_HIGHUSER_MOVABLE.
Signed-off-by: Inki Dae inki.dae@samsung.com Signed-off-by: Kyungmin Park kyungmin.park@samsung.com --- drivers/gpu/drm/exynos/exynos_drm_gem.c | 14 +++----------- 1 files changed, 3 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c b/drivers/gpu/drm/exynos/exynos_drm_gem.c index 5c8b683..c29c02d 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_gem.c +++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c @@ -99,25 +99,17 @@ out: struct page **exynos_gem_get_pages(struct drm_gem_object *obj, gfp_t gfpmask) { - struct inode *inode; - struct address_space *mapping; struct page *p, **pages; int i, npages;
- /* This is the shared memory object that backs the GEM resource */ - inode = obj->filp->f_path.dentry->d_inode; - mapping = inode->i_mapping; - npages = obj->size >> PAGE_SHIFT;
pages = drm_malloc_ab(npages, sizeof(struct page *)); if (pages == NULL) return ERR_PTR(-ENOMEM);
- gfpmask |= mapping_gfp_mask(mapping); - for (i = 0; i < npages; i++) { - p = shmem_read_mapping_page_gfp(mapping, i, gfpmask); + p = alloc_page(gfpmask); if (IS_ERR(p)) goto fail; pages[i] = p; @@ -127,7 +119,7 @@ struct page **exynos_gem_get_pages(struct drm_gem_object *obj,
fail: while (i--) - page_cache_release(pages[i]); + __free_page(pages[i]);
drm_free_large(pages); return ERR_PTR(PTR_ERR(p)); @@ -189,7 +181,7 @@ static int exynos_drm_gem_get_pages(struct drm_gem_object *obj) return -EINVAL; }
- pages = exynos_gem_get_pages(obj, GFP_KERNEL); + pages = exynos_gem_get_pages(obj, GFP_HIGHUSER_MOVABLE); if (IS_ERR(pages)) { DRM_ERROR("failed to get pages.\n"); return PTR_ERR(pages);