From dc066a78500a52bbfd57d4909d4596dbb11b5249 Mon Sep 17 00:00:00 2001 From: Matthew Auld Date: Fri, 28 Oct 2022 16:50:26 +0100 Subject: [PATCH] drm/i915/dmabuf: fix sg_table handling in map_dma_buf MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit commit f90daa975911961b65070ec72bd7dd8d448f9ef7 upstream. We need to iterate over the original entries here for the sg_table, pulling out the struct page for each one, to be remapped. However currently this incorrectly iterates over the final dma mapped entries, which is likely just one gigantic sg entry if the iommu is enabled, leading to us only mapping the first struct page (and any physically contiguous pages following it), even if there is potentially lots more data to follow. Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/7306 Fixes: 1286ff739773 ("i915: add dmabuf/prime buffer sharing support.") Signed-off-by: Matthew Auld Cc: Lionel Landwerlin Cc: Tvrtko Ursulin Cc: Ville Syrjälä Cc: Michael J. Ruhl Cc: # v3.5+ Reviewed-by: Michael J. Ruhl Link: https://patchwork.freedesktop.org/patch/msgid/20221028155029.494736-1-matthew.auld@intel.com (cherry picked from commit 28d52f99bbca7227008cf580c9194c9b3516968e) Signed-off-by: Tvrtko Ursulin Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c index afa3411..af74c9c3 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c @@ -34,13 +34,13 @@ static struct sg_table *i915_gem_map_dma_buf(struct dma_buf_attachment *attachme goto err; } - ret = sg_alloc_table(st, obj->mm.pages->nents, GFP_KERNEL); + ret = sg_alloc_table(st, obj->mm.pages->orig_nents, GFP_KERNEL); if (ret) goto err_free; src = obj->mm.pages->sgl; dst = st->sgl; - for (i = 0; i < obj->mm.pages->nents; i++) { + for (i = 0; i < obj->mm.pages->orig_nents; i++) { sg_set_page(dst, sg_page(src), src->length, 0); dst = sg_next(dst); src = sg_next(src); -- 2.7.4