drm/i915: Switch to use HWS indices rather than addresses

If we use the STORE_DATA_INDEX function we can use a fixed offset and
avoid having to lookup up the engine HWS address. A step closer to being
able to emit the final breadcrumb during request_add rather than later
in the submission interrupt handler.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190318095204.9913-9-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/intel_guc_submission.c

@@ -583,7 +583,8 @@ static void inject_preempt_context(struct work_struct *work)
 		} else {
 			cs = gen8_emit_ggtt_write(cs,
 						  GUC_PREEMPT_FINISHED,
-						  addr);
+						  addr,
+						  0);
 			*cs++ = MI_NOOP;
 			*cs++ = MI_NOOP;
 		}

drivers/gpu/drm/i915/intel_lrc.c

@@ -173,12 +173,6 @@ static void execlists_init_reg_state(u32 *reg_state,
 				     struct intel_engine_cs *engine,
 				     struct intel_ring *ring);
 
-static inline u32 intel_hws_hangcheck_address(struct intel_engine_cs *engine)
-{
-	return (i915_ggtt_offset(engine->status_page.vma) +
-		I915_GEM_HWS_HANGCHECK_ADDR);
-}
-
 static inline struct i915_priolist *to_priolist(struct rb_node *rb)
 {
 	return rb_entry(rb, struct i915_priolist, node);
@@ -2214,11 +2208,14 @@ static u32 *gen8_emit_fini_breadcrumb(struct i915_request *request, u32 *cs)
 {
 	cs = gen8_emit_ggtt_write(cs,
 				  request->fence.seqno,
-				  request->timeline->hwsp_offset);
+				  request->timeline->hwsp_offset,
+				  0);
 
 	cs = gen8_emit_ggtt_write(cs,
 				  intel_engine_next_hangcheck_seqno(request->engine),
-				  intel_hws_hangcheck_address(request->engine));
+				  I915_GEM_HWS_HANGCHECK_ADDR,
+				  MI_FLUSH_DW_STORE_INDEX);
+
 
 	*cs++ = MI_USER_INTERRUPT;
 	*cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE;
@@ -2242,8 +2239,8 @@ static u32 *gen8_emit_fini_breadcrumb_rcs(struct i915_request *request, u32 *cs)
 
 	cs = gen8_emit_ggtt_write_rcs(cs,
 				      intel_engine_next_hangcheck_seqno(request->engine),
-				      intel_hws_hangcheck_address(request->engine),
-				      0);
+				      I915_GEM_HWS_HANGCHECK_ADDR,
+				      PIPE_CONTROL_STORE_DATA_INDEX);
 
 	*cs++ = MI_USER_INTERRUPT;
 	*cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE;

drivers/gpu/drm/i915/intel_ringbuffer.c

@@ -43,12 +43,6 @@
  */
 #define LEGACY_REQUEST_SIZE 200
 
-static inline u32 hws_hangcheck_address(struct intel_engine_cs *engine)
-{
-	return (i915_ggtt_offset(engine->status_page.vma) +
-		I915_GEM_HWS_HANGCHECK_ADDR);
-}
-
 unsigned int intel_ring_update_space(struct intel_ring *ring)
 {
 	unsigned int space;
@@ -317,8 +311,8 @@ static u32 *gen6_rcs_emit_breadcrumb(struct i915_request *rq, u32 *cs)
 	*cs++ = rq->fence.seqno;
 
 	*cs++ = GFX_OP_PIPE_CONTROL(4);
-	*cs++ = PIPE_CONTROL_QW_WRITE;
-	*cs++ = hws_hangcheck_address(rq->engine) | PIPE_CONTROL_GLOBAL_GTT;
+	*cs++ = PIPE_CONTROL_QW_WRITE | PIPE_CONTROL_STORE_DATA_INDEX;
+	*cs++ = I915_GEM_HWS_HANGCHECK_ADDR | PIPE_CONTROL_GLOBAL_GTT;
 	*cs++ = intel_engine_next_hangcheck_seqno(rq->engine);
 
 	*cs++ = MI_USER_INTERRUPT;
@@ -423,8 +417,10 @@ static u32 *gen7_rcs_emit_breadcrumb(struct i915_request *rq, u32 *cs)
 	*cs++ = rq->fence.seqno;
 
 	*cs++ = GFX_OP_PIPE_CONTROL(4);
-	*cs++ = PIPE_CONTROL_QW_WRITE | PIPE_CONTROL_GLOBAL_GTT_IVB;
-	*cs++ = hws_hangcheck_address(rq->engine);
+	*cs++ = (PIPE_CONTROL_QW_WRITE |
+		 PIPE_CONTROL_STORE_DATA_INDEX |
+		 PIPE_CONTROL_GLOBAL_GTT_IVB);
+	*cs++ = I915_GEM_HWS_HANGCHECK_ADDR;
 	*cs++ = intel_engine_next_hangcheck_seqno(rq->engine);
 
 	*cs++ = MI_USER_INTERRUPT;

drivers/gpu/drm/i915/intel_ringbuffer.h

@@ -408,14 +408,14 @@ gen8_emit_ggtt_write_rcs(u32 *cs, u32 value, u32 gtt_offset, u32 flags)
 }
 
 static inline u32 *
-gen8_emit_ggtt_write(u32 *cs, u32 value, u32 gtt_offset)
+gen8_emit_ggtt_write(u32 *cs, u32 value, u32 gtt_offset, u32 flags)
 {
 	/* w/a: bit 5 needs to be zero for MI_FLUSH_DW address. */
 	GEM_BUG_ON(gtt_offset & (1 << 5));
 	/* Offset should be aligned to 8 bytes for both (QW/DW) write types */
 	GEM_BUG_ON(!IS_ALIGNED(gtt_offset, 8));
 
-	*cs++ = (MI_FLUSH_DW + 1) | MI_FLUSH_DW_OP_STOREDW;
+	*cs++ = (MI_FLUSH_DW + 1) | MI_FLUSH_DW_OP_STOREDW | flags;
 	*cs++ = gtt_offset | MI_FLUSH_DW_USE_GTT;
 	*cs++ = 0;
 	*cs++ = value;