4 files changed, 19 insertions, 15 deletions

diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c
index 991e76e10f82..6193ad7edcf4 100644
--- a/drivers/gpu/drm/i915/i915_guc_submission.c
+++ b/drivers/gpu/drm/i915/i915_guc_submission.c
@@ -481,7 +481,7 @@ static void guc_wq_item_append(struct i915_guc_client *client,
 
 	/* The GuC firmware wants the tail index in QWords, not bytes */
 	tail = rq->tail;
-	GEM_BUG_ON(tail & 7);
+	assert_ring_tail_valid(rq->ring, rq->tail);
 	tail >>= 3;
 	GEM_BUG_ON(tail > WQ_RING_TAIL_MAX);
 
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 39cb84a5d4e4..b0c3a029b592 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -326,8 +326,7 @@ static u64 execlists_update_context(struct drm_i915_gem_request *rq)
 		rq->ctx->ppgtt ?: rq->i915->mm.aliasing_ppgtt;
 	u32 *reg_state = ce->lrc_reg_state;
 
-	GEM_BUG_ON(!IS_ALIGNED(rq->tail, 8));
-	GEM_BUG_ON(rq->tail >= rq->ring->size);
+	assert_ring_tail_valid(rq->ring, rq->tail);
 	reg_state[CTX_RING_TAIL+1] = rq->tail;
 
 	/* True 32b PPGTT with dynamic page allocation: update PDP
@@ -1282,8 +1281,7 @@ static void reset_common_ring(struct intel_engine_cs *engine,
 	request->tail =
 		intel_ring_wrap(request->ring,
 				request->wa_tail - WA_TAIL_DWORDS*sizeof(u32));
-	GEM_BUG_ON(!IS_ALIGNED(request->tail, 8));
-	GEM_BUG_ON(request->tail >= request->ring->size);
+	assert_ring_tail_valid(request->ring, request->tail);
 }
 
 static int intel_logical_ring_emit_pdps(struct drm_i915_gem_request *req)
@@ -1494,8 +1492,7 @@ static void gen8_emit_breadcrumb(struct drm_i915_gem_request *request, u32 *cs)
 	*cs++ = MI_USER_INTERRUPT;
 	*cs++ = MI_NOOP;
 	request->tail = intel_ring_offset(request, cs);
-	GEM_BUG_ON(!IS_ALIGNED(request->tail, 8));
-	GEM_BUG_ON(request->tail >= request->ring->size);
+	assert_ring_tail_valid(request->ring, request->tail);
 
 	gen8_emit_wa_tail(request, cs);
 }
@@ -1523,8 +1520,7 @@ static void gen8_emit_breadcrumb_render(struct drm_i915_gem_request *request,
 	*cs++ = MI_USER_INTERRUPT;
 	*cs++ = MI_NOOP;
 	request->tail = intel_ring_offset(request, cs);
-	GEM_BUG_ON(!IS_ALIGNED(request->tail, 8));
-	GEM_BUG_ON(request->tail >= request->ring->size);
+	assert_ring_tail_valid(request->ring, request->tail);
 
 	gen8_emit_wa_tail(request, cs);
 }
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 47921dcbedb3..66a2b8b83972 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -774,8 +774,7 @@ static void i9xx_submit_request(struct drm_i915_gem_request *request)
 
 	i915_gem_request_submit(request);
 
-	GEM_BUG_ON(!IS_ALIGNED(request->tail, 8));
-	GEM_BUG_ON(request->tail >= request->ring->size);
+	assert_ring_tail_valid(request->ring, request->tail);
 	I915_WRITE_TAIL(request->engine, request->tail);
 }
 
@@ -787,8 +786,7 @@ static void i9xx_emit_breadcrumb(struct drm_i915_gem_request *req, u32 *cs)
 	*cs++ = MI_USER_INTERRUPT;
 
 	req->tail = intel_ring_offset(req, cs);
-	GEM_BUG_ON(!IS_ALIGNED(req->tail, 8));
-	GEM_BUG_ON(req->tail >= req->ring->size);
+	assert_ring_tail_valid(req->ring, req->tail);
 }
 
 static const int i9xx_emit_breadcrumb_sz = 4;
@@ -827,8 +825,7 @@ static void gen8_render_emit_breadcrumb(struct drm_i915_gem_request *req,
 	*cs++ = MI_NOOP;
 
 	req->tail = intel_ring_offset(req, cs);
-	GEM_BUG_ON(!IS_ALIGNED(req->tail, 8));
-	GEM_BUG_ON(req->tail >= req->ring->size);
+	assert_ring_tail_valid(req->ring, req->tail);
 }
 
 static const int gen8_render_emit_breadcrumb_sz = 8;
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 17ac44980d84..a82a0807f64d 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -529,6 +529,17 @@ intel_ring_offset(const struct drm_i915_gem_request *req, void *addr)
 	return intel_ring_wrap(req->ring, offset);
 }
 
+static inline void
+assert_ring_tail_valid(const struct intel_ring *ring, unsigned int tail)
+{
+	/* We could combine these into a single tail operation, but keeping
+	 * them as seperate tests will help identify the cause should one
+	 * ever fire.
+	 */
+	GEM_BUG_ON(!IS_ALIGNED(tail, 8));
+	GEM_BUG_ON(tail >= ring->size);
+}
+
 void intel_ring_update_space(struct intel_ring *ring);
 
 void intel_engine_init_global_seqno(struct intel_engine_cs *engine, u32 seqno);