drm/ttm: swap consecutive allocated pooled pages v4

When we detect consecutive allocation of pages swap them to avoid
accidentally freeing them as huge page.

v2: use swap
v3: check if it's really the first allocated page
v4: don't touch the loop variable

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Roger He <Hongbo.He@amd.com>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Tested-by: Dieter Nützel <Dieter@nuetzel-hh.de>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 9 insertions, 2 deletions

diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc.c b/drivers/gpu/drm/ttm/ttm_page_alloc.c
index b6f7ce286fb1..44343a2bf55c 100644
--- a/drivers/gpu/drm/ttm/ttm_page_alloc.c
+++ b/drivers/gpu/drm/ttm/ttm_page_alloc.c
@@ -958,8 +958,15 @@ static int ttm_get_pages(struct page **pages, unsigned npages, int flags,
         r = ttm_page_pool_get_pages(pool, &plist, flags, cstate,
                                     npages - count, 0);
 
-        list_for_each_entry(p, &plist, lru)
-                pages[count++] = p;
+        first = count;
+        list_for_each_entry(p, &plist, lru) {
+                struct page *tmp = p;
+
+                /* Swap the pages if we detect consecutive order */
+                if (count > first && pages[count - 1] == tmp - 1)
+                        swap(tmp, pages[count - 1]);
+                pages[count++] = tmp;
+        }
 
         if (r) {
                 /* If there is any pages in the list put them back to