[Intel-gfx] [PATCH 0/4] Compact userptr object backing store allocation

[Tvrtko Ursulin]

From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Userptr backing store with SWIOTBL active is currently allocated in the same
inefficient manner, with one sg entry per object page, as what the commit
871dfbd67d4e ("drm/i915: Allow compaction upto SWIOTLB max segment size") fixed
for regular GEM objects.

We can fix that by adding new a __sg_alloc_table_from_pages core function which
allows us to control the maximum desired coalesced segment size.

Other than that the series starts with two simple fixes to
sg_alloc_table_from_pages which deal with incorrect data type usage and a
theoretical overflow condition. Fixing the latter enables easy addition of the
above mentioned __sg_alloc_table_from_pages.

Tvrtko Ursulin (4):
  lib/scatterlist: Fix offset type in sg_alloc_table_from_pages
  lib/scatterlist: Avoid potential scatterlist entry overflow
  lib/scatterlist: Introduce and export __sg_alloc_table_from_pages
  drm/i915: Use __sg_alloc_table_from_pages for userptr allocations

 drivers/gpu/drm/i915/i915_drv.h                |  9 +++
 drivers/gpu/drm/i915/i915_gem.c                | 15 +----
 drivers/gpu/drm/i915/i915_gem_userptr.c        | 28 ++-------
 drivers/media/v4l2-core/videobuf2-dma-contig.c |  4 +-
 drivers/rapidio/devices/rio_mport_cdev.c       |  4 +-
 include/linux/scatterlist.h                    | 11 ++--
 lib/scatterlist.c                              | 78 ++++++++++++++++++++------
 7 files changed, 87 insertions(+), 62 deletions(-)

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2.7.4