drm/i915: Implement pwrite without struct-mutex
authorChris Wilson <chris@chris-wilson.co.uk>
Fri, 28 Oct 2016 12:58:40 +0000 (13:58 +0100)
committerChris Wilson <chris@chris-wilson.co.uk>
Fri, 28 Oct 2016 19:53:48 +0000 (20:53 +0100)
commitfe115628d567ba83a1498c585604d9035842b57c
tree811b57f4682badeeca57641a2522736f3c5f1a75
parentbb6dc8d96b683a6052162c36062cd8e9329e4f21
drm/i915: Implement pwrite without struct-mutex

We only need struct_mutex within pwrite for a brief window where we need
to serialise with rendering and control our cache domains. Elsewhere we
can rely on the backing storage being pinned, and forgive userspace any
races against us.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161028125858.23563-17-chris@chris-wilson.co.uk
drivers/gpu/drm/i915/i915_gem.c