drm/i915: Move user fault tracking to a separate list
authorChris Wilson <chris@chris-wilson.co.uk>
Mon, 24 Oct 2016 12:42:14 +0000 (13:42 +0100)
committerChris Wilson <chris@chris-wilson.co.uk>
Mon, 24 Oct 2016 12:45:35 +0000 (13:45 +0100)
commit275f039db56f998aaf6e2fc74acd1f653cdcb480
tree710f40b0ae09810630d61c3a82c883d5e6477b85
parent352cb4ef2d345fbe1955278890f9ea12cbe7bd21
drm/i915: Move user fault tracking to a separate list

We want to decouple RPM and struct_mutex, but currently RPM has to walk
the list of bound objects and remove userspace mmapping before we
suspend (otherwise userspace may continue to access the GTT whilst it is
powered down). This currently requires the struct_mutex to walk the
bound_list, but if we move that to a separate list and lock we can take
the first step towards removing the struct_mutex.

v2: Split runtime suspend unmapping vs regular unmapping, to make the
locking (and barriers) clearer. Add the object to the userfault_list
prior to inserting the first PTE, the race between add/revoke depends
upon struct_mutex for regular unmappings and rpm for runtime-suspend.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> #v1
Link: http://patchwork.freedesktop.org/patch/msgid/20161024124218.18252-1-chris@chris-wilson.co.uk
drivers/gpu/drm/i915/i915_debugfs.c
drivers/gpu/drm/i915/i915_drv.h
drivers/gpu/drm/i915/i915_gem.c
drivers/gpu/drm/i915/i915_gem_evict.c
drivers/gpu/drm/i915/i915_gem_fence.c