drm/i915: Enable resource streamer bits on MI_BATCH_BUFFER_START

Adds support for enabling the resource streamer on the legacy
ringbuffer for HSW and GEN8.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NAbdiel Janulgue <abdiel.janulgue@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_reg.h

@@ -361,6 +361,7 @@
 #define MI_BATCH_BUFFER_START	MI_INSTR(0x31, 0)
 #define   MI_BATCH_GTT		    (2<<6) /* aliased with (1<<7) on gen4 */
 #define MI_BATCH_BUFFER_START_GEN8	MI_INSTR(0x31, 1)
+#define   MI_BATCH_RESOURCE_STREAMER (1<<10)
 
 #define MI_PREDICATE_SRC0	(0x2400)
 #define MI_PREDICATE_SRC1	(0x2408)

drivers/gpu/drm/i915/intel_ringbuffer.c

@@ -2448,7 +2448,9 @@ gen8_ring_dispatch_execbuffer(struct drm_i915_gem_request *req,
 		return ret;
 
 	/* FIXME(BDW): Address space and security selectors. */
-	intel_ring_emit(ring, MI_BATCH_BUFFER_START_GEN8 | (ppgtt<<8));
+	intel_ring_emit(ring, MI_BATCH_BUFFER_START_GEN8 | (ppgtt<<8) |
+			(dispatch_flags & I915_DISPATCH_RS ?
+			 MI_BATCH_RESOURCE_STREAMER : 0));
 	intel_ring_emit(ring, lower_32_bits(offset));
 	intel_ring_emit(ring, upper_32_bits(offset));
 	intel_ring_emit(ring, MI_NOOP);
@@ -2472,7 +2474,9 @@ hsw_ring_dispatch_execbuffer(struct drm_i915_gem_request *req,
 	intel_ring_emit(ring,
 			MI_BATCH_BUFFER_START |
 			(dispatch_flags & I915_DISPATCH_SECURE ?
-			 0 : MI_BATCH_PPGTT_HSW | MI_BATCH_NON_SECURE_HSW));
+			 0 : MI_BATCH_PPGTT_HSW | MI_BATCH_NON_SECURE_HSW) |
+			(dispatch_flags & I915_DISPATCH_RS ?
+			 MI_BATCH_RESOURCE_STREAMER : 0));
 	/* bit0-7 is the length on GEN6+ */
 	intel_ring_emit(ring, offset);
 	intel_ring_advance(ring);

drivers/gpu/drm/i915/intel_ringbuffer.h

@@ -199,6 +199,7 @@ struct  intel_engine_cs {
 					       unsigned dispatch_flags);
 #define I915_DISPATCH_SECURE 0x1
 #define I915_DISPATCH_PINNED 0x2
+#define I915_DISPATCH_RS     0x4
 	void		(*cleanup)(struct intel_engine_cs *ring);
 
 	/* GEN8 signal/wait table - never trust comments!