[0/3] drm/syncobj: add protection against timeline resets

Message

Lionel Landwerlin Aug. 26, 2019, 9:04 a.m. UTC

Hi all,

Following Jason's suggestion on another thread adding timeline
documentation [1], here is a small series adding a creation flag to
syncobjs so that users are prevented to drop the existing timeline
fences in the syncobj, effectivelly ensuring a user always adds to the
dma_fence_chain instead of replacing it.

We still allow explicit reset.

Apart from the fact we need to enforce this policy in each driver's
submission path, I haven't run into odds things yet.

Cheers,

[1] : https://lists.freedesktop.org/archives/dri-devel/2019-August/232700.html

Lionel Landwerlin (3):
  drm/syncobj: protect timeline syncobjs
  drm/amd/amdgpu: disallow replacing fences in timeline syncobjs
  drm/i915: disallow replacing fences of timeline syncobjs

 drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c        |  2 ++
 drivers/gpu/drm/drm_syncobj.c                 | 30 ++++++++++++++++++-
 .../gpu/drm/i915/gem/i915_gem_execbuffer.c    |  8 +++++
 include/drm/drm_syncobj.h                     |  8 +++++
 include/uapi/drm/drm.h                        |  1 +
 5 files changed, 48 insertions(+), 1 deletion(-)

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2.23.0