[Intel-gfx] [PATCH 20/55] drm/i915: Convert engine->write_tail to operate on a request

Chris Wilson chris at chris-wilson.co.uk
Mon Jul 25 17:31:59 UTC 2016


If we rewrite the I915_WRITE_TAIL specialisation for the legacy
ringbuffer as submitting the request onto the ringbuffer, we can unify
the vfunc with both execlists and GuC in the next patch.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1469432687-22756-22-git-send-email-chris@chris-wilson.co.uk
---
 drivers/gpu/drm/i915/i915_gem_request.c |  8 ++---
 drivers/gpu/drm/i915/intel_lrc.c        |  2 +-
 drivers/gpu/drm/i915/intel_ringbuffer.c | 53 +++++++++++++++++----------------
 drivers/gpu/drm/i915/intel_ringbuffer.h |  3 +-
 4 files changed, 32 insertions(+), 34 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c
index 44cdca9a2194..8af514e42c30 100644
--- a/drivers/gpu/drm/i915/i915_gem_request.c
+++ b/drivers/gpu/drm/i915/i915_gem_request.c
@@ -466,15 +466,13 @@ void __i915_add_request(struct drm_i915_gem_request *request,
 	 */
 	request->postfix = ring->tail;
 
-	if (i915.enable_execlists) {
+	if (i915.enable_execlists)
 		ret = engine->emit_request(request);
-	} else {
+	else
 		ret = engine->add_request(request);
-
-		request->tail = ring->tail;
-	}
 	/* Not allowed to fail! */
 	WARN(ret, "emit|add_request failed: %d!\n", ret);
+
 	/* Sanity check that the reserved size was large enough. */
 	ret = ring->tail - request_start;
 	if (ret < 0)
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 80a28ebb5e06..5e08b95813fe 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -373,7 +373,7 @@ static void execlists_update_context(struct drm_i915_gem_request *rq)
 	struct i915_hw_ppgtt *ppgtt = rq->ctx->ppgtt;
 	uint32_t *reg_state = rq->ctx->engine[engine->id].lrc_reg_state;
 
-	reg_state[CTX_RING_TAIL+1] = rq->tail;
+	reg_state[CTX_RING_TAIL+1] = rq->tail % (rq->ring->size - 1);
 
 	/* True 32b PPGTT with dynamic page allocation: update PDP
 	 * registers and point the unallocated PDPs to scratch page.
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index b91dc6acb84a..211b57614764 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -58,14 +58,6 @@ void intel_ring_update_space(struct intel_ring *ring)
 					 ring->tail, ring->size);
 }
 
-static void __intel_engine_submit(struct intel_engine_cs *engine)
-{
-	struct intel_ring *ring = engine->buffer;
-
-	ring->tail &= ring->size - 1;
-	engine->write_tail(engine, ring->tail);
-}
-
 static int
 gen2_render_ring_flush(struct drm_i915_gem_request *req,
 		       u32	invalidate_domains,
@@ -421,13 +413,6 @@ gen8_render_ring_flush(struct drm_i915_gem_request *req,
 	return gen8_emit_pipe_control(req, flags, scratch_addr);
 }
 
-static void ring_write_tail(struct intel_engine_cs *engine,
-			    u32 value)
-{
-	struct drm_i915_private *dev_priv = engine->i915;
-	I915_WRITE_TAIL(engine, value);
-}
-
 u64 intel_engine_get_active_head(struct intel_engine_cs *engine)
 {
 	struct drm_i915_private *dev_priv = engine->i915;
@@ -541,7 +526,7 @@ static bool stop_ring(struct intel_engine_cs *engine)
 
 	I915_WRITE_CTL(engine, 0);
 	I915_WRITE_HEAD(engine, 0);
-	engine->write_tail(engine, 0);
+	I915_WRITE_TAIL(engine, 0);
 
 	if (!IS_GEN2(dev_priv)) {
 		(void)I915_READ_CTL(engine);
@@ -1482,7 +1467,10 @@ gen6_add_request(struct drm_i915_gem_request *req)
 	intel_ring_emit(ring, I915_GEM_HWS_INDEX << MI_STORE_DWORD_INDEX_SHIFT);
 	intel_ring_emit(ring, req->fence.seqno);
 	intel_ring_emit(ring, MI_USER_INTERRUPT);
-	__intel_engine_submit(engine);
+	intel_ring_advance(ring);
+
+	req->tail = ring->tail;
+	engine->submit_request(req);
 
 	return 0;
 }
@@ -1512,7 +1500,9 @@ gen8_render_add_request(struct drm_i915_gem_request *req)
 	intel_ring_emit(ring, 0);
 	intel_ring_emit(ring, MI_USER_INTERRUPT);
 	intel_ring_emit(ring, MI_NOOP);
-	__intel_engine_submit(engine);
+
+	req->tail = ring->tail;
+	engine->submit_request(req);
 
 	return 0;
 }
@@ -1731,11 +1721,22 @@ i9xx_add_request(struct drm_i915_gem_request *req)
 	intel_ring_emit(ring, I915_GEM_HWS_INDEX << MI_STORE_DWORD_INDEX_SHIFT);
 	intel_ring_emit(ring, req->fence.seqno);
 	intel_ring_emit(ring, MI_USER_INTERRUPT);
-	__intel_engine_submit(req->engine);
+	intel_ring_advance(ring);
+
+	req->tail = ring->tail;
+	req->engine->submit_request(req);
 
 	return 0;
 }
 
+static void i9xx_submit_request(struct drm_i915_gem_request *request)
+{
+	struct drm_i915_private *dev_priv = request->i915;
+
+	I915_WRITE_TAIL(request->engine,
+			request->tail % (request->ring->size - 1));
+}
+
 static void
 gen6_irq_enable(struct intel_engine_cs *engine)
 {
@@ -2494,10 +2495,9 @@ void intel_engine_init_seqno(struct intel_engine_cs *engine, u32 seqno)
 	rcu_read_unlock();
 }
 
-static void gen6_bsd_ring_write_tail(struct intel_engine_cs *engine,
-				     u32 value)
+static void gen6_bsd_submit_request(struct drm_i915_gem_request *request)
 {
-	struct drm_i915_private *dev_priv = engine->i915;
+	struct drm_i915_private *dev_priv = request->i915;
 
 	intel_uncore_forcewake_get(dev_priv, FORCEWAKE_ALL);
 
@@ -2521,8 +2521,9 @@ static void gen6_bsd_ring_write_tail(struct intel_engine_cs *engine,
 		DRM_ERROR("timed out waiting for the BSD ring to wake up\n");
 
 	/* Now that the ring is fully powered up, update the tail */
-	I915_WRITE_FW(RING_TAIL(engine->mmio_base), value);
-	POSTING_READ_FW(RING_TAIL(engine->mmio_base));
+	I915_WRITE_FW(RING_TAIL(request->engine->mmio_base),
+		      request->tail % (request->ring->size - 1));
+	POSTING_READ_FW(RING_TAIL(request->engine->mmio_base));
 
 	/* Let the ring send IDLE messages to the GT again,
 	 * and so let it sleep to conserve power when idle.
@@ -2828,7 +2829,7 @@ static void intel_ring_default_vfuncs(struct drm_i915_private *dev_priv,
 				      struct intel_engine_cs *engine)
 {
 	engine->init_hw = init_ring_common;
-	engine->write_tail = ring_write_tail;
+	engine->submit_request = i9xx_submit_request;
 
 	engine->add_request = i9xx_add_request;
 	if (INTEL_GEN(dev_priv) >= 6)
@@ -2912,7 +2913,7 @@ int intel_init_bsd_ring_buffer(struct intel_engine_cs *engine)
 	if (INTEL_GEN(dev_priv) >= 6) {
 		/* gen6 bsd needs a special wa for tail updates */
 		if (IS_GEN6(dev_priv))
-			engine->write_tail = gen6_bsd_ring_write_tail;
+			engine->submit_request = gen6_bsd_submit_request;
 		engine->emit_flush = gen6_bsd_ring_flush;
 		if (INTEL_GEN(dev_priv) < 8)
 			engine->irq_enable_mask = GT_BSD_USER_INTERRUPT;
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index d5a866ddaded..38bea2bf9457 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -204,8 +204,6 @@ struct intel_engine_cs {
 
 	int		(*init_context)(struct drm_i915_gem_request *req);
 
-	void		(*write_tail)(struct intel_engine_cs *engine,
-				      u32 value);
 	int		(*add_request)(struct drm_i915_gem_request *req);
 	/* Some chipsets are not quite as coherent as advertised and need
 	 * an expensive kick to force a true read of the up-to-date seqno.
@@ -294,6 +292,7 @@ struct intel_engine_cs {
 #define I915_DISPATCH_SECURE 0x1
 #define I915_DISPATCH_PINNED 0x2
 #define I915_DISPATCH_RS     0x4
+	void		(*submit_request)(struct drm_i915_gem_request *req);
 
 	/**
 	 * List of objects currently involved in rendering from the
-- 
2.8.1



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