[PATCH 0/2] Default to cachable mappings for GEM SHMEM

[Thomas Zimmermann]

This patchset complements Daniel's recent patches for SHMEM. [1]

By default SHMEM maps pages using writecombine. Only virtio sets the
SHMEM implmentation to use cached mappings. Udl implements its own
vmap/mmap functions, which always maps pages with caching.

Unify the settings by switching the SHMEM code to use cached mappings
(i.e., PAGE_KERNEL actually). The exception is dma-buf imported pages,
which are still mapped using writecombine.

Tested with udl-driven hardware.

[1] https://lists.freedesktop.org/archives/dri-devel/2020-May/265468.html

Thomas Zimmermann (2):
  drm/shmem: Use cached mappings by default
  drm/udl: Use GEM vmap/mmap function from SHMEM helpers

 drivers/gpu/drm/drm_gem_shmem_helper.c  |   6 +-
 drivers/gpu/drm/udl/Makefile            |   2 +-
 drivers/gpu/drm/udl/udl_drv.c           |   3 -
 drivers/gpu/drm/udl/udl_drv.h           |   3 -
 drivers/gpu/drm/udl/udl_gem.c           | 106 ------------------------
 drivers/gpu/drm/virtio/virtgpu_object.c |   1 -
 include/drm/drm_gem_shmem_helper.h      |   4 +-
 7 files changed, 7 insertions(+), 118 deletions(-)
 delete mode 100644 drivers/gpu/drm/udl/udl_gem.c

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2.26.2