drm/i915: Add OACONTROL to the command parser register whitelist.

Mesa needs to be able to write OACONTROL in order to expose the
Observability Architecture's performance counters via OpenGL.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
[danvet: Add comment that this is just a temporary work-around and
that we need to check more things before we can allow OACONTROL writes
for real everywhere.]
[danvet 2: Squash in fixup to avoid a DRM_ERROR due to unsorted reg
list, spotted by Jani.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_cmd_parser.c

@@ -407,6 +407,12 @@ static const u32 gen7_render_regs[] = {
 	REG64(CL_PRIMITIVES_COUNT),
 	REG64(PS_INVOCATION_COUNT),
 	REG64(PS_DEPTH_COUNT),
+	/*
+	 * FIXME: This is just to keep mesa working for now, we need to check
+	 * that mesa resets this again and that it doesn't use any of the
+	 * special modes which write into the gtt.
+	 */
+	OACONTROL,
 	REG64(GEN7_SO_NUM_PRIMS_WRITTEN(0)),
 	REG64(GEN7_SO_NUM_PRIMS_WRITTEN(1)),
 	REG64(GEN7_SO_NUM_PRIMS_WRITTEN(2)),

drivers/gpu/drm/i915/i915_reg.h

@@ -427,6 +427,8 @@
 /* There are the 4 64-bit counter registers, one for each stream output */
 #define GEN7_SO_NUM_PRIMS_WRITTEN(n) (0x5200 + (n) * 8)
 
+#define OACONTROL 0x2360
+
 #define _GEN7_PIPEA_DE_LOAD_SL	0x70068
 #define _GEN7_PIPEB_DE_LOAD_SL	0x71068
 #define GEN7_PIPE_DE_LOAD_SL(pipe) _PIPE(pipe, \