drm/i915: Cache LRC state page in the context
authorTvrtko Ursulin <tvrtko.ursulin@intel.com>
Fri, 15 Jan 2016 17:12:45 +0000 (17:12 +0000)
committerTvrtko Ursulin <tvrtko.ursulin@intel.com>
Mon, 18 Jan 2016 09:58:44 +0000 (09:58 +0000)
commit82352e908acd36d7244c75a008c9f27a2ced44d5
tree0dfab70e4ff5de1ebf0d15fb78b4dced5e5796e1
parent0eb973d31d0aadb6bc801fd6d796afecbbfc3d5b
drm/i915: Cache LRC state page in the context

LRC lifetime is well defined so we can cache the page pointing
to the object backing store in the context in order to avoid
walking over the object SG page list from the interrupt context
without the big lock held.

v2: Also cache the mapping. (Chris Wilson)
v3: Unmap on the error path.
v4: No need to cache the page. (Chris Wilson)
v5: No need to dirty the page on unpin. (Chris Wilson)
v6: kmap() cannot fail and use kmap_to_page to simplify unpin.
    (Chris Wilson)

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Dave Gordon <david.s.gordon@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1452877965-32042-1-git-send-email-tvrtko.ursulin@linux.intel.com
drivers/gpu/drm/i915/i915_drv.h
drivers/gpu/drm/i915/intel_lrc.c