drm/i915: Add VM to context
authorBen Widawsky <benjamin.widawsky@intel.com>
Fri, 6 Dec 2013 22:11:15 +0000 (14:11 -0800)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Wed, 18 Dec 2013 14:31:20 +0000 (15:31 +0100)
commitc7c48dfdff246d65408ff4f336978cc861722ca4
tree276dd9417513ef6a8f7dd0b1cdb1bbea0e0b5908
parent246cbfb5fb9a1ca0997fbb135464c1ff5bb9c549
drm/i915: Add VM to context

Pretty straightforward so far except for the bit about the refcounting.
The PPGTT will potentially be shared amongst multiple contexts. Because
contexts themselves have a refcounted lifecycle, the easiest way to
manage this will be to refcount the PPGTT. To acheive this, we piggy
back off of the existing context refcount, and will increment and
decrement the PPGTT refcount with context creation, and destruction.

To put it more clearly, if context A, and context B both use PPGTT 0, we
can't free the PPGTT until both A, and B are destroyed.

Note that because the PPGTT is permanently pinned (for now), it really
just matters for the PPGTT destruction, as opposed to making space under
memory pressure.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drivers/gpu/drm/i915/i915_drv.h
drivers/gpu/drm/i915/i915_gem_context.c
drivers/gpu/drm/i915/i915_gem_gtt.c