linux-uconsole/drivers/gpu
Dave Gordon 033908aed5 drm/i915: mark GEM object pages dirty when mapped & written by the CPU
In various places, a single page of a (regular) GEM object is mapped into
CPU address space and updated. In each such case, either the page or the
the object should be marked dirty, to ensure that the modifications are
not discarded if the object is evicted under memory pressure.

The typical sequence is:
	va = kmap_atomic(i915_gem_object_get_page(obj, pageno));
	*(va+offset) = ...
	kunmap_atomic(va);

Here we introduce i915_gem_object_get_dirty_page(), which performs the
same operation as i915_gem_object_get_page() but with the side-effect
of marking the returned page dirty in the pagecache.  This will ensure
that if the object is subsequently evicted (due to memory pressure),
the changes are written to backing store rather than discarded.

Note that it works only for regular (shmfs-backed) GEM objects, but (at
least for now) those are the only ones that are updated in this way --
the objects in question are contexts and batchbuffers, which are always
shmfs-backed.

Separate patches deal with the cases where whole objects are (or may
be) dirtied.

v3: Mark two more pages dirty in the page-boundary-crossing
    cases of the execbuffer relocation code [Chris Wilson]

Signed-off-by: Dave Gordon <david.s.gordon@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1449773486-30822-2-git-send-email-david.s.gordon@intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-12-11 18:11:53 +01:00
..
drm drm/i915: mark GEM object pages dirty when mapped & written by the CPU 2015-12-11 18:11:53 +01:00
host1x gpu: host1x: Fix MLOCK's debug info 2015-10-02 14:40:12 +02:00
ipu-v3 imx-drm fixes and color format updates 2015-11-05 11:06:56 +10:00
vga vga_switcheroo: Drop client power state VGA_SWITCHEROO_INIT 2015-11-05 11:07:36 +10:00
Makefile