[Intel-gfx] [PATCH 0/2] Fix prime_mmap to work when using LMEM

Gwan-gyeong Mun gwan-gyeong.mun at intel.com
Fri Feb 25 13:13:14 UTC 2022

The current implementation of i915 prime mmap only worked when initializing
drm_i915_gem_object with shmem_region.
When using LMEM, drm_i915_gem_object is initialized with ttm_system_region.
In order to make prime mmap work even this case, when using LMEM
(when using ttm in i915), dma_buf_ops.mmap callback calls drm_gem_prime_mmap().
drm_gem_prime_mmap() of drm core calls internally i915_gem_mmap() so that
prime mmap can perform normally.
The fake offset is processed inside drm_gem_prime_mmap().
Testcase: igt/prime_mmap
This patch makes  all of igt/prime_mmap tests success on gpus which use LMEM.

And these series remove defining and using a duplicate function: i915_gem_unmap_dma_buf()

After landing this patch. I'm going to send refactoring rfc patches that
handles the drm_driver.gem_prime_mmap callback, drm_gem_object_funcs.mmap
callback and drm_gem_object_funcs.vm_ops calllback.
ref: https://01.org/linuxgraphics/gfx-docs/drm/gpu/todo.html?#clean-up-mmap-forwarding

Gwan-gyeong Mun (2):
  drm/i915/dmabuf: Update dma_buf_ops.unmap_dma_buf callback to use
  drm/i915/dmabuf: Fix prime_mmap to work when using LMEM

 drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)


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