| Message ID | 20201201235847.1860-1-chris@chris-wilson.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/2] drm/i915/gem: Limit lmem scatterlist elements to UINT_MAX | expand |
On 01/12/2020 23:58, Chris Wilson wrote: > Adhere to the i915_sg_max_segment() limit on the lengths of individual > scatterlist elements, and in doing so split up very large chunks of lmem > into managable pieces for the dma-mapping backend. > > Reported-by: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota@intel.com> > Suggested-by: Matthew Auld <matthew.auld@intel.com> > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> > Cc: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota@intel.com> > Cc: Matthew Auld <matthew.auld@intel.com> > --- > drivers/gpu/drm/i915/gem/i915_gem_region.c | 42 ++++++++++++---------- > 1 file changed, 24 insertions(+), 18 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_region.c b/drivers/gpu/drm/i915/gem/i915_gem_region.c > index e72d78074c9e..edb84072f979 100644 > --- a/drivers/gpu/drm/i915/gem/i915_gem_region.c > +++ b/drivers/gpu/drm/i915/gem/i915_gem_region.c > @@ -22,6 +22,7 @@ i915_gem_object_put_pages_buddy(struct drm_i915_gem_object *obj, > int > i915_gem_object_get_pages_buddy(struct drm_i915_gem_object *obj) > { > + const u64 max_segment = i915_sg_segment_size(); I think we just need to add: @@ -150,8 +150,8 @@ static int igt_mock_contiguous(void *arg) if (IS_ERR(obj)) return PTR_ERR(obj); - if (obj->mm.pages->nents != 1) { - pr_err("%s min object spans multiple sg entries\n", __func__); + if (!list_is_singular(&obj->mm.blocks)) { + pr_err("%s min object spans multiple blocks\n", __func__); err = -EINVAL; goto err_close_objects; } @@ -163,8 +163,8 @@ static int igt_mock_contiguous(void *arg) if (IS_ERR(obj)) return PTR_ERR(obj); - if (obj->mm.pages->nents != 1) { - pr_err("%s max object spans multiple sg entries\n", __func__); + if (!list_is_singular(&obj->mm.blocks)) { + pr_err("%s max object spans multiple blocks\n", __func__); err = -EINVAL; goto err_close_objects; } @@ -189,8 +189,8 @@ static int igt_mock_contiguous(void *arg) goto err_close_objects; } - if (obj->mm.pages->nents != 1) { - pr_err("%s object spans multiple sg entries\n", __func__); + if (!list_is_singular(&obj->mm.blocks)) { + pr_err("%s object spans multiple blocks\n", __func__); err = -EINVAL; goto err_close_objects; } Thanks for fixing this, Reviewed-by: Matthew Auld <matthew.auld@intel.com> > struct intel_memory_region *mem = obj->mm.region; > struct list_head *blocks = &obj->mm.blocks; > resource_size_t size = obj->base.size; > @@ -37,7 +38,7 @@ i915_gem_object_get_pages_buddy(struct drm_i915_gem_object *obj) > if (!st) > return -ENOMEM; > > - if (sg_alloc_table(st, size >> ilog2(mem->mm.chunk_size), GFP_KERNEL)) { > + if (sg_alloc_table(st, size >> PAGE_SHIFT, GFP_KERNEL)) { > kfree(st); > return -ENOMEM; > } > @@ -58,33 +59,38 @@ i915_gem_object_get_pages_buddy(struct drm_i915_gem_object *obj) > prev_end = (resource_size_t)-1; > > list_for_each_entry(block, blocks, link) { > - u64 block_size, offset; > + u64 block_size, offset, len; > > block_size = min_t(u64, size, > i915_buddy_block_size(&mem->mm, block)); > offset = i915_buddy_block_offset(block); > > - GEM_BUG_ON(overflows_type(block_size, sg->length)); > + while (block_size) { > + if (offset != prev_end || sg->length >= max_segment) { > + if (st->nents) { > + sg_page_sizes |= sg->length; > + sg = __sg_next(sg); > + } > > - if (offset != prev_end || > - add_overflows_t(typeof(sg->length), sg->length, block_size)) { > - if (st->nents) { > - sg_page_sizes |= sg->length; > - sg = __sg_next(sg); > - } > + len = min(block_size, max_segment); > > - sg_dma_address(sg) = mem->region.start + offset; > - sg_dma_len(sg) = block_size; > + sg_dma_address(sg) = mem->region.start + offset; > + sg_dma_len(sg) = len; > > - sg->length = block_size; > + sg->length = len; > > - st->nents++; > - } else { > - sg->length += block_size; > - sg_dma_len(sg) += block_size; > - } > + st->nents++; > + } else { > + len = min(block_size, max_segment - sg->length); > + sg->length += len; > + sg_dma_len(sg) += len; > + } > > - prev_end = offset + block_size; > + offset += len; > + block_size -= len; > + > + prev_end = offset; > + } > } > > sg_page_sizes |= sg->length; >
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_region.c b/drivers/gpu/drm/i915/gem/i915_gem_region.c index e72d78074c9e..edb84072f979 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_region.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_region.c @@ -22,6 +22,7 @@ i915_gem_object_put_pages_buddy(struct drm_i915_gem_object *obj, int i915_gem_object_get_pages_buddy(struct drm_i915_gem_object *obj) { + const u64 max_segment = i915_sg_segment_size(); struct intel_memory_region *mem = obj->mm.region; struct list_head *blocks = &obj->mm.blocks; resource_size_t size = obj->base.size; @@ -37,7 +38,7 @@ i915_gem_object_get_pages_buddy(struct drm_i915_gem_object *obj) if (!st) return -ENOMEM; - if (sg_alloc_table(st, size >> ilog2(mem->mm.chunk_size), GFP_KERNEL)) { + if (sg_alloc_table(st, size >> PAGE_SHIFT, GFP_KERNEL)) { kfree(st); return -ENOMEM; } @@ -58,33 +59,38 @@ i915_gem_object_get_pages_buddy(struct drm_i915_gem_object *obj) prev_end = (resource_size_t)-1; list_for_each_entry(block, blocks, link) { - u64 block_size, offset; + u64 block_size, offset, len; block_size = min_t(u64, size, i915_buddy_block_size(&mem->mm, block)); offset = i915_buddy_block_offset(block); - GEM_BUG_ON(overflows_type(block_size, sg->length)); + while (block_size) { + if (offset != prev_end || sg->length >= max_segment) { + if (st->nents) { + sg_page_sizes |= sg->length; + sg = __sg_next(sg); + } - if (offset != prev_end || - add_overflows_t(typeof(sg->length), sg->length, block_size)) { - if (st->nents) { - sg_page_sizes |= sg->length; - sg = __sg_next(sg); - } + len = min(block_size, max_segment); - sg_dma_address(sg) = mem->region.start + offset; - sg_dma_len(sg) = block_size; + sg_dma_address(sg) = mem->region.start + offset; + sg_dma_len(sg) = len; - sg->length = block_size; + sg->length = len; - st->nents++; - } else { - sg->length += block_size; - sg_dma_len(sg) += block_size; - } + st->nents++; + } else { + len = min(block_size, max_segment - sg->length); + sg->length += len; + sg_dma_len(sg) += len; + } - prev_end = offset + block_size; + offset += len; + block_size -= len; + + prev_end = offset; + } } sg_page_sizes |= sg->length;
Adhere to the i915_sg_max_segment() limit on the lengths of individual scatterlist elements, and in doing so split up very large chunks of lmem into managable pieces for the dma-mapping backend. Reported-by: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota@intel.com> Suggested-by: Matthew Auld <matthew.auld@intel.com> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota@intel.com> Cc: Matthew Auld <matthew.auld@intel.com> --- drivers/gpu/drm/i915/gem/i915_gem_region.c | 42 ++++++++++++---------- 1 file changed, 24 insertions(+), 18 deletions(-)