drm/i915: Don't prefault the entire obj if the vma is smaller
authorVille Syrjälä <ville.syrjala@linux.intel.com>
Tue, 17 Jun 2014 18:03:00 +0000 (21:03 +0300)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Tue, 17 Jun 2014 22:48:35 +0000 (00:48 +0200)
commitbeff0d0f6121f6a2a818a050a1e4d91706b3f190
tree46b84c371dc7ebddfe45c90b07a9893dad0a2dd0
parent84c33a64b4e29757d04ba1b285b96ee160d5ff93
drm/i915: Don't prefault the entire obj if the vma is smaller

Take the minimum of the object size and the vma size and prefault
only that much. Avoids a SIGBUS when mmapping only a portion of the
object.

Prefaulting was introduced here:
 commit b90b91d87038f6b257b40a02b42ed4f9705e06f0
 Author: Chris Wilson <chris@chris-wilson.co.uk>
 Date:   Tue Jun 10 12:14:40 2014 +0100

    drm/i915: Prefault the entire object on first page fault

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Testcase: igt/gem_mmap/short-mmap
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drivers/gpu/drm/i915/i915_gem.c