1 files changed, 20 insertions, 9 deletions

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index f7d71190aad5..6adee4c2afc0 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -441,18 +441,31 @@ EXPORT_SYMBOL(drm_gem_create_mmap_offset);
  * drm_gem_get_pages - helper to allocate backing pages for a GEM object
  * from shmem
  * @obj: obj in question
- * @gfpmask: gfp mask of requested pages
+ *
+ * This reads the page-array of the shmem-backing storage of the given gem
+ * object. An array of pages is returned. If a page is not allocated or
+ * swapped-out, this will allocate/swap-in the required pages. Note that the
+ * whole object is covered by the page-array and pinned in memory.
+ *
+ * Use drm_gem_put_pages() to release the array and unpin all pages.
+ *
+ * This uses the GFP-mask set on the shmem-mapping (see mapping_set_gfp_mask()).
+ * If you require other GFP-masks, you have to do those allocations yourself.
+ *
+ * Note that you are not allowed to change gfp-zones during runtime. That is,
+ * shmem_read_mapping_page_gfp() must be called with the same gfp_zone(gfp) as
+ * set during initialization. If you have special zone constraints, set them
+ * after drm_gem_init_object() via mapping_set_gfp_mask(). shmem-core takes care
+ * to keep pages in the required zone during swap-in.
  */
-struct page **drm_gem_get_pages(struct drm_gem_object *obj, gfp_t gfpmask)
+struct page **drm_gem_get_pages(struct drm_gem_object *obj)
 {
-        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 = file_inode(obj->filp);
-        mapping = inode->i_mapping;
+        mapping = file_inode(obj->filp)->i_mapping;
 
         /* We already BUG_ON() for non-page-aligned sizes in
          * drm_gem_object_init(), so we should never hit this unless
@@ -466,10 +479,8 @@ struct page **drm_gem_get_pages(struct drm_gem_object *obj, gfp_t gfpmask)
         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 = shmem_read_mapping_page(mapping, i);
                 if (IS_ERR(p))
                         goto fail;
                 pages[i] = p;
@@ -479,7 +490,7 @@ struct page **drm_gem_get_pages(struct drm_gem_object *obj, gfp_t gfpmask)
                  * __GFP_DMA32 to be set in mapping_gfp_mask(inode->i_mapping)
                  * so shmem can relocate pages during swapin if required.
                  */
-                BUG_ON((gfpmask & __GFP_DMA32) &&
+                BUG_ON((mapping_gfp_mask(mapping) & __GFP_DMA32) &&
                                 (page_to_pfn(p) >= 0x00100000UL));
         }