drm/i915: Use __sg_alloc_table_from_pages for userptr allocations
With the addition of __sg_alloc_table_from_pages we can control
the maximum coalescing size and eliminate a separate path for
allocating backing store here.
Similar to 871dfbd67d4e ("drm/i915: Allow compaction upto
SWIOTLB max segment size") this enables more compact sg lists to
be created and so has a beneficial effect on workloads with many
and/or large objects of this class.
v2:
* Rename helper to i915_sg_segment_size and fix swiotlb override.
* Commit message update.
v3:
* Actually include the swiotlb override fix.
v4:
* Regroup parameters a bit. (Chris Wilson)
v5:
* Rebase for swiotlb_max_segment.
* Add DMA map failure handling as in abb0deacb5a6
("drm/i915: Fallback to single PAGE_SIZE segments for DMA remapping").
v6: Handle swiotlb_max_segment() returning 1. (Joonas Lahtinen)
v7: Rebase.
v8: Commit spelling fix.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170803091417.23677-1-tvrtko.ursulin@linux.intel.com
3 files changed