drm: convert drm_gem_put_pages() to use a folio_batch

Remove a few hidden compound_head() calls by converting the returned page
to a folio once and using the folio APIs.

Link: https://lkml.kernel.org/r/20230621164557.3510324-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 1a5a2cd..78dcae2 100644 (file)
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -496,13 +496,13 @@ int drm_gem_create_mmap_offset(struct drm_gem_object *obj)
 EXPORT_SYMBOL(drm_gem_create_mmap_offset);
 
 /*
- * Move pages to appropriate lru and release the pagevec, decrementing the
- * ref count of those pages.
+ * Move folios to appropriate lru and release the folios, decrementing the
+ * ref count of those folios.
  */
-static void drm_gem_check_release_pagevec(struct pagevec *pvec)
+static void drm_gem_check_release_batch(struct folio_batch *fbatch)
 {
-       check_move_unevictable_pages(pvec);
-       __pagevec_release(pvec);
+       check_move_unevictable_folios(fbatch);
+       __folio_batch_release(fbatch);
        cond_resched();
 }
 
@@ -534,10 +534,10 @@ static void drm_gem_check_release_pagevec(struct pagevec *pvec)
 struct page **drm_gem_get_pages(struct drm_gem_object *obj)
 {
        struct address_space *mapping;
-       struct page *p, **pages;
-       struct pagevec pvec;
-       int i, npages;
-
+       struct page **pages;
+       struct folio *folio;
+       struct folio_batch fbatch;
+       int i, j, npages;
 
        if (WARN_ON(!obj->filp))
                return ERR_PTR(-EINVAL);
@@ -559,11 +559,14 @@ struct page **drm_gem_get_pages(struct drm_gem_object *obj)
 
        mapping_set_unevictable(mapping);
 
-       for (i = 0; i < npages; i++) {
-               p = shmem_read_mapping_page(mapping, i);
-               if (IS_ERR(p))
+       i = 0;
+       while (i < npages) {
+               folio = shmem_read_folio_gfp(mapping, i,
+                               mapping_gfp_mask(mapping));
+               if (IS_ERR(folio))
                        goto fail;
-               pages[i] = p;
+               for (j = 0; j < folio_nr_pages(folio); j++, i++)
+                       pages[i] = folio_file_page(folio, i);
 
                /* Make sure shmem keeps __GFP_DMA32 allocated pages in the
                 * correct region during swapin. Note that this requires
@@ -571,23 +574,26 @@ struct page **drm_gem_get_pages(struct drm_gem_object *obj)
                 * so shmem can relocate pages during swapin if required.
                 */
                BUG_ON(mapping_gfp_constraint(mapping, __GFP_DMA32) &&
-                               (page_to_pfn(p) >= 0x00100000UL));
+                               (folio_pfn(folio) >= 0x00100000UL));
        }
 
        return pages;
 
 fail:
        mapping_clear_unevictable(mapping);
-       pagevec_init(&pvec);
-       while (i--) {
-               if (!pagevec_add(&pvec, pages[i]))
-                       drm_gem_check_release_pagevec(&pvec);
+       folio_batch_init(&fbatch);
+       j = 0;
+       while (j < i) {
+               struct folio *f = page_folio(pages[j]);
+               if (!folio_batch_add(&fbatch, f))
+                       drm_gem_check_release_batch(&fbatch);
+               j += folio_nr_pages(f);
        }
-       if (pagevec_count(&pvec))
-               drm_gem_check_release_pagevec(&pvec);
+       if (fbatch.nr)
+               drm_gem_check_release_batch(&fbatch);
 
        kvfree(pages);
-       return ERR_CAST(p);
+       return ERR_CAST(folio);
 }
 EXPORT_SYMBOL(drm_gem_get_pages);
 
@@ -603,7 +609,7 @@ void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,
 {
        int i, npages;
        struct address_space *mapping;
-       struct pagevec pvec;
+       struct folio_batch fbatch;
 
        mapping = file_inode(obj->filp)->i_mapping;
        mapping_clear_unevictable(mapping);
@@ -616,23 +622,27 @@ void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,
 
        npages = obj->size >> PAGE_SHIFT;
 
-       pagevec_init(&pvec);
+       folio_batch_init(&fbatch);
        for (i = 0; i < npages; i++) {
+               struct folio *folio;
+
                if (!pages[i])
                        continue;
+               folio = page_folio(pages[i]);
 
                if (dirty)
-                       set_page_dirty(pages[i]);
+                       folio_mark_dirty(folio);
 
                if (accessed)
-                       mark_page_accessed(pages[i]);
+                       folio_mark_accessed(folio);
 
                /* Undo the reference we took when populating the table */
-               if (!pagevec_add(&pvec, pages[i]))
-                       drm_gem_check_release_pagevec(&pvec);
+               if (!folio_batch_add(&fbatch, folio))
+                       drm_gem_check_release_batch(&fbatch);
+               i += folio_nr_pages(folio) - 1;
        }
-       if (pagevec_count(&pvec))
-               drm_gem_check_release_pagevec(&pvec);
+       if (folio_batch_count(&fbatch))
+               drm_gem_check_release_batch(&fbatch);
 
        kvfree(pages);
 }