From: Thomas Hellström thomas.hellstrom@linux.intel.com
Break out some shmem backend utils for future reuse by the TTM backend: shmem_alloc_st(), shmem_free_st() and __shmem_writeback() which we can use to provide a shmem-backed TTM page pool for cached-only TTM buffer objects.
Main functional change here is that we now compute the page sizes using the dma segments rather than using the physical page address segments.
v2(Reported-by: kernel test robot lkp@intel.com) - Make sure we initialise the mapping on the error path in shmem_get_pages()
Signed-off-by: Thomas Hellström thomas.hellstrom@linux.intel.com Reviewed-by: Matthew Auld matthew.auld@intel.com Signed-off-by: Matthew Auld matthew.auld@intel.com --- drivers/gpu/drm/i915/gem/i915_gem_shmem.c | 181 +++++++++++++--------- 1 file changed, 106 insertions(+), 75 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c index 11f072193f3b..36b711ae9e28 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c @@ -25,46 +25,61 @@ static void check_release_pagevec(struct pagevec *pvec) cond_resched(); }
-static int shmem_get_pages(struct drm_i915_gem_object *obj) +static void shmem_free_st(struct sg_table *st, struct address_space *mapping, + bool dirty, bool backup) { - struct drm_i915_private *i915 = to_i915(obj->base.dev); - struct intel_memory_region *mem = obj->mm.region; - const unsigned long page_count = obj->base.size / PAGE_SIZE; + struct sgt_iter sgt_iter; + struct pagevec pvec; + struct page *page; + + mapping_clear_unevictable(mapping); + + pagevec_init(&pvec); + for_each_sgt_page(page, sgt_iter, st) { + if (dirty) + set_page_dirty(page); + + if (backup) + mark_page_accessed(page); + + if (!pagevec_add(&pvec, page)) + check_release_pagevec(&pvec); + } + if (pagevec_count(&pvec)) + check_release_pagevec(&pvec); + + sg_free_table(st); + kfree(st); +} + +static struct sg_table *shmem_alloc_st(struct drm_i915_private *i915, + size_t size, struct intel_memory_region *mr, + struct address_space *mapping, + unsigned int max_segment) +{ + const unsigned long page_count = size / PAGE_SIZE; unsigned long i; - struct address_space *mapping; struct sg_table *st; struct scatterlist *sg; - struct sgt_iter sgt_iter; struct page *page; unsigned long last_pfn = 0; /* suppress gcc warning */ - unsigned int max_segment = i915_sg_segment_size(); - unsigned int sg_page_sizes; gfp_t noreclaim; int ret;
- /* - * Assert that the object is not currently in any GPU domain. As it - * wasn't in the GTT, there shouldn't be any way it could have been in - * a GPU cache - */ - GEM_BUG_ON(obj->read_domains & I915_GEM_GPU_DOMAINS); - GEM_BUG_ON(obj->write_domain & I915_GEM_GPU_DOMAINS); - /* * If there's no chance of allocating enough pages for the whole * object, bail early. */ - if (obj->base.size > resource_size(&mem->region)) - return -ENOMEM; + if (size > resource_size(&mr->region)) + return ERR_PTR(-ENOMEM);
st = kmalloc(sizeof(*st), GFP_KERNEL); if (!st) - return -ENOMEM; + return ERR_PTR(-ENOMEM);
-rebuild_st: if (sg_alloc_table(st, page_count, GFP_KERNEL)) { kfree(st); - return -ENOMEM; + return ERR_PTR(-ENOMEM); }
/* @@ -73,14 +88,12 @@ static int shmem_get_pages(struct drm_i915_gem_object *obj) * * Fail silently without starting the shrinker */ - mapping = obj->base.filp->f_mapping; mapping_set_unevictable(mapping); noreclaim = mapping_gfp_constraint(mapping, ~__GFP_RECLAIM); noreclaim |= __GFP_NORETRY | __GFP_NOWARN;
sg = st->sgl; st->nents = 0; - sg_page_sizes = 0; for (i = 0; i < page_count; i++) { const unsigned int shrink[] = { I915_SHRINK_BOUND | I915_SHRINK_UNBOUND, @@ -135,10 +148,9 @@ static int shmem_get_pages(struct drm_i915_gem_object *obj) if (!i || sg->length >= max_segment || page_to_pfn(page) != last_pfn + 1) { - if (i) { - sg_page_sizes |= sg->length; + if (i) sg = sg_next(sg); - } + st->nents++; sg_set_page(sg, page, PAGE_SIZE, 0); } else { @@ -149,14 +161,65 @@ static int shmem_get_pages(struct drm_i915_gem_object *obj) /* Check that the i965g/gm workaround works. */ GEM_BUG_ON(gfp & __GFP_DMA32 && last_pfn >= 0x00100000UL); } - if (sg) { /* loop terminated early; short sg table */ - sg_page_sizes |= sg->length; + if (sg) /* loop terminated early; short sg table */ sg_mark_end(sg); - }
/* Trim unused sg entries to avoid wasting memory. */ i915_sg_trim(st);
+ return st; +err_sg: + sg_mark_end(sg); + if (sg != st->sgl) { + shmem_free_st(st, mapping, false, false); + } else { + mapping_clear_unevictable(mapping); + sg_free_table(st); + kfree(st); + } + + /* + * shmemfs first checks if there is enough memory to allocate the page + * and reports ENOSPC should there be insufficient, along with the usual + * ENOMEM for a genuine allocation failure. + * + * We use ENOSPC in our driver to mean that we have run out of aperture + * space and so want to translate the error from shmemfs back to our + * usual understanding of ENOMEM. + */ + if (ret == -ENOSPC) + ret = -ENOMEM; + + return ERR_PTR(ret); +} + +static int shmem_get_pages(struct drm_i915_gem_object *obj) +{ + struct drm_i915_private *i915 = to_i915(obj->base.dev); + struct intel_memory_region *mem = obj->mm.region; + struct address_space *mapping = obj->base.filp->f_mapping; + const unsigned long page_count = obj->base.size / PAGE_SIZE; + unsigned int max_segment = i915_sg_segment_size(); + struct sg_table *st; + struct sgt_iter sgt_iter; + struct page *page; + int ret; + + /* + * Assert that the object is not currently in any GPU domain. As it + * wasn't in the GTT, there shouldn't be any way it could have been in + * a GPU cache + */ + GEM_BUG_ON(obj->read_domains & I915_GEM_GPU_DOMAINS); + GEM_BUG_ON(obj->write_domain & I915_GEM_GPU_DOMAINS); + +rebuild_st: + st = shmem_alloc_st(i915, obj->base.size, mem, mapping, max_segment); + if (IS_ERR(st)) { + ret = PTR_ERR(st); + goto err_st; + } + ret = i915_gem_gtt_prepare_pages(obj, st); if (ret) { /* @@ -168,6 +231,7 @@ static int shmem_get_pages(struct drm_i915_gem_object *obj) for_each_sgt_page(page, sgt_iter, st) put_page(page); sg_free_table(st); + kfree(st);
max_segment = PAGE_SIZE; goto rebuild_st; @@ -200,28 +264,12 @@ static int shmem_get_pages(struct drm_i915_gem_object *obj) if (IS_JSL_EHL(i915) && obj->flags & I915_BO_ALLOC_USER) obj->cache_dirty = true;
- __i915_gem_object_set_pages(obj, st, sg_page_sizes); + __i915_gem_object_set_pages(obj, st, i915_sg_dma_sizes(st->sgl));
return 0;
-err_sg: - sg_mark_end(sg); err_pages: - mapping_clear_unevictable(mapping); - if (sg != st->sgl) { - struct pagevec pvec; - - pagevec_init(&pvec); - for_each_sgt_page(page, sgt_iter, st) { - if (!pagevec_add(&pvec, page)) - check_release_pagevec(&pvec); - } - if (pagevec_count(&pvec)) - check_release_pagevec(&pvec); - } - sg_free_table(st); - kfree(st); - + shmem_free_st(st, mapping, 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 @@ -231,6 +279,7 @@ static int shmem_get_pages(struct drm_i915_gem_object *obj) * space and so want to translate the error from shmemfs back to our * usual understanding of ENOMEM. */ +err_st: if (ret == -ENOSPC) ret = -ENOMEM;
@@ -251,10 +300,8 @@ shmem_truncate(struct drm_i915_gem_object *obj) obj->mm.pages = ERR_PTR(-EFAULT); }
-static void -shmem_writeback(struct drm_i915_gem_object *obj) +static void __shmem_writeback(size_t size, struct address_space *mapping) { - struct address_space *mapping; struct writeback_control wbc = { .sync_mode = WB_SYNC_NONE, .nr_to_write = SWAP_CLUSTER_MAX, @@ -270,10 +317,9 @@ shmem_writeback(struct drm_i915_gem_object *obj) * instead of invoking writeback so they are aged and paged out * as normal. */ - mapping = obj->base.filp->f_mapping;
/* Begin writeback on each dirty page */ - for (i = 0; i < obj->base.size >> PAGE_SHIFT; i++) { + for (i = 0; i < size >> PAGE_SHIFT; i++) { struct page *page;
page = find_lock_page(mapping, i); @@ -296,6 +342,12 @@ shmem_writeback(struct drm_i915_gem_object *obj) } }
+static void +shmem_writeback(struct drm_i915_gem_object *obj) +{ + __shmem_writeback(obj->base.size, obj->base.filp->f_mapping); +} + void __i915_gem_object_release_shmem(struct drm_i915_gem_object *obj, struct sg_table *pages, @@ -316,11 +368,6 @@ __i915_gem_object_release_shmem(struct drm_i915_gem_object *obj,
void i915_gem_object_put_pages_shmem(struct drm_i915_gem_object *obj, struct sg_table *pages) { - struct sgt_iter sgt_iter; - struct pagevec pvec; - struct page *page; - - GEM_WARN_ON(IS_DGFX(to_i915(obj->base.dev))); __i915_gem_object_release_shmem(obj, pages, true);
i915_gem_gtt_finish_pages(obj, pages); @@ -328,25 +375,9 @@ 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);
- mapping_clear_unevictable(file_inode(obj->base.filp)->i_mapping); - - pagevec_init(&pvec); - for_each_sgt_page(page, sgt_iter, pages) { - if (obj->mm.dirty) - set_page_dirty(page); - - if (obj->mm.madv == I915_MADV_WILLNEED) - mark_page_accessed(page); - - if (!pagevec_add(&pvec, page)) - check_release_pagevec(&pvec); - } - if (pagevec_count(&pvec)) - check_release_pagevec(&pvec); + shmem_free_st(pages, file_inode(obj->base.filp)->i_mapping, + obj->mm.dirty, obj->mm.madv == I915_MADV_WILLNEED); obj->mm.dirty = false; - - sg_free_table(pages); - kfree(pages); }
static void