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. v1 -> v2: (Ville) Fixed locations where we were not clearing mapping unevictable. Cc: stable@xxxxxxxxxxxxxxx Cc: Ville Syrjala <ville.syrjala@xxxxxxxxxxxxxxx> Cc: Vidya Srinivas <vidya.srinivas@xxxxxxxxx> Link: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/13487 Link: https://lore.kernel.org/lkml/20250116135636.410164-1-bgeffon@xxxxxxxxxx/ Fixes: 0b62af28f249 ("i915: convert shmem_sg_free_table() to use a folio_batch") Signed-off-by: Brian Geffon <bgeffon@xxxxxxxxxx> Suggested-by: Tomasz Figa <tfiga@xxxxxxxxxx> --- drivers/gpu/drm/i915/gem/i915_gem_object.h | 3 +-- drivers/gpu/drm/i915/gem/i915_gem_shmem.c | 23 +++++++++------------- drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 7 ++++--- 3 files changed, 14 insertions(+), 19 deletions(-) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h b/drivers/gpu/drm/i915/gem/i915_gem_object.h index 3dc61cbd2e11..0f122a12d4a5 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_object.h +++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h @@ -843,8 +843,7 @@ int shmem_sg_alloc_table(struct drm_i915_private *i915, struct sg_table *st, size_t size, struct intel_memory_region *mr, struct address_space *mapping, unsigned int max_segment); -void shmem_sg_free_table(struct sg_table *st, struct address_space *mapping, - bool dirty, bool backup); +void shmem_sg_free_table(struct sg_table *st, bool dirty, bool backup); void __shmem_writeback(size_t size, struct address_space *mapping); #ifdef CONFIG_MMU_NOTIFIER diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c index fe69f2c8527d..b320d9dfd6d3 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c @@ -29,16 +29,13 @@ static void check_release_folio_batch(struct folio_batch *fbatch) cond_resched(); } -void shmem_sg_free_table(struct sg_table *st, struct address_space *mapping, - bool dirty, bool backup) +void shmem_sg_free_table(struct sg_table *st, bool dirty, bool backup) { struct sgt_iter sgt_iter; struct folio_batch fbatch; struct folio *last = NULL; struct page *page; - mapping_clear_unevictable(mapping); - folio_batch_init(&fbatch); for_each_sgt_page(page, sgt_iter, st) { struct folio *folio = page_folio(page); @@ -180,10 +177,10 @@ int shmem_sg_alloc_table(struct drm_i915_private *i915, struct sg_table *st, return 0; err_sg: sg_mark_end(sg); + mapping_clear_unevictable(mapping); if (sg != st->sgl) { - shmem_sg_free_table(st, mapping, false, false); + shmem_sg_free_table(st, false, false); } else { - mapping_clear_unevictable(mapping); sg_free_table(st); } @@ -209,8 +206,6 @@ 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 +234,8 @@ static int shmem_get_pages(struct drm_i915_gem_object *obj) * 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); + /* Leave the mapping unevictable while we retry */ + shmem_sg_free_table(st, false, false); kfree(st); max_segment = PAGE_SIZE; @@ -265,7 +259,8 @@ static int shmem_get_pages(struct drm_i915_gem_object *obj) return 0; err_pages: - shmem_sg_free_table(st, mapping, false, false); + mapping_clear_unevictable(mapping); + shmem_sg_free_table(st, false, false); /* * shmemfs first checks if there is enough memory to allocate the page * and reports ENOSPC should there be insufficient, along with the usual @@ -402,8 +397,8 @@ void i915_gem_object_put_pages_shmem(struct drm_i915_gem_object *obj, struct sg_ if (i915_gem_object_needs_bit17_swizzle(obj)) i915_gem_object_save_bit_17_swizzle(obj, pages); - shmem_sg_free_table(pages, file_inode(obj->base.filp)->i_mapping, - obj->mm.dirty, obj->mm.madv == I915_MADV_WILLNEED); + mapping_clear_unevictable(file_inode(obj->base.filp)->i_mapping); + shmem_sg_free_table(pages, obj->mm.dirty, obj->mm.madv == I915_MADV_WILLNEED); kfree(pages); obj->mm.dirty = false; } diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c index 10d8673641f7..37f51a04b838 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c @@ -232,7 +232,8 @@ static int i915_ttm_tt_shmem_populate(struct ttm_device *bdev, return 0; err_free_st: - shmem_sg_free_table(st, filp->f_mapping, false, false); + mapping_clear_unevictable(filp->f_mapping); + shmem_sg_free_table(st, false, false); return err; } @@ -243,8 +244,8 @@ static void i915_ttm_tt_shmem_unpopulate(struct ttm_tt *ttm) bool backup = ttm->page_flags & TTM_TT_FLAG_SWAPPED; struct sg_table *st = &i915_tt->cached_rsgt.table; - shmem_sg_free_table(st, file_inode(i915_tt->filp)->i_mapping, - backup, backup); + mapping_clear_unevictable(file_inode(i915_tt->filp)->i_mapping); + shmem_sg_free_table(st, backup, backup); } static void i915_ttm_tt_release(struct kref *ref) -- 2.48.0.rc2.279.g1de40edade-goog
