Remove a few hidden compound_head() calls by converting the returned
page to a folio once and using the folio APIs.  We also only increment
the refcount on the folio once instead of once for each page.  Ideally,
we would have a for_each_sgt_folio macro, but until then this will do.

Signed-off-by: Matthew Wilcox (Oracle) <wi...@infradead.org>
---
 drivers/gpu/drm/i915/gem/i915_gem_shmem.c | 55 +++++++++++++----------
 1 file changed, 31 insertions(+), 24 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c 
b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
index 33d5d5178103..8f1633c3fb93 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
@@ -19,13 +19,13 @@
 #include "i915_trace.h"
 
 /*
- * Move pages to appropriate lru and release the pagevec, decrementing the
- * ref count of those pages.
+ * Move folios to appropriate lru and release the batch, decrementing the
+ * ref count of those folios.
  */
-static void check_release_pagevec(struct pagevec *pvec)
+static void check_release_folio_batch(struct folio_batch *fbatch)
 {
-       check_move_unevictable_pages(pvec);
-       __pagevec_release(pvec);
+       check_move_unevictable_folios(fbatch);
+       __folio_batch_release(fbatch);
        cond_resched();
 }
 
@@ -33,24 +33,29 @@ void shmem_sg_free_table(struct sg_table *st, struct 
address_space *mapping,
                         bool dirty, bool backup)
 {
        struct sgt_iter sgt_iter;
-       struct pagevec pvec;
+       struct folio_batch fbatch;
+       struct folio *last = NULL;
        struct page *page;
 
        mapping_clear_unevictable(mapping);
 
-       pagevec_init(&pvec);
+       folio_batch_init(&fbatch);
        for_each_sgt_page(page, sgt_iter, st) {
-               if (dirty)
-                       set_page_dirty(page);
+               struct folio *folio = page_folio(page);
 
+               if (folio == last)
+                       continue;
+               last = folio;
+               if (dirty)
+                       folio_mark_dirty(folio);
                if (backup)
-                       mark_page_accessed(page);
+                       folio_mark_accessed(folio);
 
-               if (!pagevec_add(&pvec, page))
-                       check_release_pagevec(&pvec);
+               if (!folio_batch_add(&fbatch, folio))
+                       check_release_folio_batch(&fbatch);
        }
-       if (pagevec_count(&pvec))
-               check_release_pagevec(&pvec);
+       if (fbatch.nr)
+               check_release_folio_batch(&fbatch);
 
        sg_free_table(st);
 }
@@ -63,8 +68,7 @@ int shmem_sg_alloc_table(struct drm_i915_private *i915, 
struct sg_table *st,
        unsigned int page_count; /* restricted by sg_alloc_table */
        unsigned long i;
        struct scatterlist *sg;
-       struct page *page;
-       unsigned long last_pfn = 0;     /* suppress gcc warning */
+       unsigned long next_pfn = 0;     /* suppress gcc warning */
        gfp_t noreclaim;
        int ret;
 
@@ -95,6 +99,7 @@ int shmem_sg_alloc_table(struct drm_i915_private *i915, 
struct sg_table *st,
        sg = st->sgl;
        st->nents = 0;
        for (i = 0; i < page_count; i++) {
+               struct folio *folio;
                const unsigned int shrink[] = {
                        I915_SHRINK_BOUND | I915_SHRINK_UNBOUND,
                        0,
@@ -103,12 +108,12 @@ int shmem_sg_alloc_table(struct drm_i915_private *i915, 
struct sg_table *st,
 
                do {
                        cond_resched();
-                       page = shmem_read_mapping_page_gfp(mapping, i, gfp);
-                       if (!IS_ERR(page))
+                       folio = shmem_read_folio_gfp(mapping, i, gfp);
+                       if (!IS_ERR(folio))
                                break;
 
                        if (!*s) {
-                               ret = PTR_ERR(page);
+                               ret = PTR_ERR(folio);
                                goto err_sg;
                        }
 
@@ -147,19 +152,21 @@ int shmem_sg_alloc_table(struct drm_i915_private *i915, 
struct sg_table *st,
 
                if (!i ||
                    sg->length >= max_segment ||
-                   page_to_pfn(page) != last_pfn + 1) {
+                   folio_pfn(folio) != next_pfn) {
                        if (i)
                                sg = sg_next(sg);
 
                        st->nents++;
-                       sg_set_page(sg, page, PAGE_SIZE, 0);
+                       sg_set_folio(sg, folio, folio_size(folio), 0);
                } else {
-                       sg->length += PAGE_SIZE;
+                       /* XXX: could overflow? */
+                       sg->length += folio_size(folio);
                }
-               last_pfn = page_to_pfn(page);
+               next_pfn = folio_pfn(folio) + folio_nr_pages(folio);
+               i += folio_nr_pages(folio) - 1;
 
                /* Check that the i965g/gm workaround works. */
-               GEM_BUG_ON(gfp & __GFP_DMA32 && last_pfn >= 0x00100000UL);
+               GEM_BUG_ON(gfp & __GFP_DMA32 && next_pfn >= 0x00100000UL);
        }
        if (sg) /* loop terminated early; short sg table */
                sg_mark_end(sg);
-- 
2.39.2

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