drm/i915: Fix page cleanup on DMA remap failure

When converting to folios the cleanup path of shmem_get_pages() was
missed. When a DMA remap fails and the max segment size is greater than
PAGE_SIZE it will attempt to retry the remap with a PAGE_SIZEd segment
size. The cleanup code isn't properly using the folio apis and as a
result isn't handling compound pages correctly.

v2 -> v3:
(Ville) Just use shmem_sg_free_table() as-is in the failure path of
shmem_get_pages(). shmem_sg_free_table() will clear mapping unevictable
but it will be reset when it retries in shmem_sg_alloc_table().

v1 -> v2:
(Ville) Fixed locations where we were not clearing mapping unevictable.

Cc: stable@vger.kernel.org
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Cc: Vidya Srinivas <vidya.srinivas@intel.com>
Link: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/13487
Link: https://lore.kernel.org/lkml/20250116135636.410164-1-bgeffon@google.com/
Fixes: 0b62af28f249 ("i915: convert shmem_sg_free_table() to use a folio_batch")
Signed-off-by: Brian Geffon <bgeffon@google.com>
Suggested-by: Tomasz Figa <tfiga@google.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250127204332.336665-1-bgeffon@google.com
Reviewed-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Tested-by: Vidya Srinivas <vidya.srinivas@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
index c5e1c718a6d2620cc839dec2ef41d4bf623e90fa..1e202e7f4efd1a60cf46413e16e14bbc80cad17c 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
@@ -209,8 +209,6 @@ static int shmem_get_pages(struct drm_i915_gem_object *obj)
        struct address_space *mapping = obj->base.filp->f_mapping;
        unsigned int max_segment = i915_sg_segment_size(i915->drm.dev);
        struct sg_table *st;
-       struct sgt_iter sgt_iter;
-       struct page *page;
        int ret;
 
        /*
@@ -239,9 +237,7 @@ rebuild_st:
                 * for PAGE_SIZE chunks instead may be helpful.
                 */
                if (max_segment > PAGE_SIZE) {
-                       for_each_sgt_page(page, sgt_iter, st)
-                               put_page(page);
-                       sg_free_table(st);
+                       shmem_sg_free_table(st, mapping, false, false);
                        kfree(st);
 
                        max_segment = PAGE_SIZE;