| Message ID | 20221028155029.494736-1-matthew.auld@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2,1/4] drm/i915/dmabuf: fix sg_table handling in map_dma_buf | expand |
>-----Original Message----- >From: Auld, Matthew <matthew.auld@intel.com> >Sent: Friday, October 28, 2022 11:50 AM >To: intel-gfx@lists.freedesktop.org >Cc: Landwerlin, Lionel G <lionel.g.landwerlin@intel.com>; Tvrtko Ursulin ><tvrtko.ursulin@linux.intel.com>; Ville Syrjälä <ville.syrjala@linux.intel.com>; >Ruhl, Michael J <michael.j.ruhl@intel.com> >Subject: [PATCH v2 1/4] drm/i915/dmabuf: fix sg_table handling in >map_dma_buf > >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. I like this patch set a lot better.
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c index 07eee1c09aaf..05ebbdfd3b3b 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c @@ -40,13 +40,13 @@ 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);
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 Signed-off-by: Matthew Auld <matthew.auld@intel.com> Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Michael J. Ruhl <michael.j.ruhl@intel.com> --- drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)