[Intel-gfx] [PATCH] drm/i915: Refactor tests for validity of RING_TAIL

[Chris Wilson]

Whilst I like having the assertions clearly visible in the code, they
are quite repetitious! As we find new limits we want to incorporate into
the set of assertions, it make sense to refactor them to a common
routine.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/intel_lrc.c        | 12 ++++--------
 drivers/gpu/drm/i915/intel_ringbuffer.c |  9 +++------
 drivers/gpu/drm/i915/intel_ringbuffer.h |  7 +++++++
 3 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 3b84fbb7da5d..ccbe1a16f3c3 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
@@ -1304,8 +1303,7 @@ static void reset_common_ring(struct intel_engine_cs *engine,
 	/* Reset WaIdleLiteRestore:bdw,skl as well */
 	request->tail = request->wa_tail - WA_TAIL_DWORDS * sizeof(u32);
 	request->tail &= request->ring->size - 1;
-	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)
@@ -1516,8 +1514,7 @@ 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);
 }
@@ -1545,8 +1542,7 @@ 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 2ecb41788fb6..6bc89719250a 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -523,6 +523,13 @@ intel_ring_offset(struct drm_i915_gem_request *req, void *addr)
 	return offset & (req->ring->size - 1);
 }
 
+static inline void
+assert_ring_tail_valid(const struct intel_ring *ring, unsigned int tail)
+{
+	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);
-- 
2.11.0