In preparation for removing the manual EMIT_FLUSH prior to emitting the
breadcrumb implement the flush inline with writing the breadcrumb for
ringbuffer emission.
With a combined flush+breadcrumb, we can use a single operation to both
flush and after the flush is complete (post-sync) write the breadcrumb.
This gives us a strongly ordered operation that should be sufficient to
serialise the write before we emit the interrupt; and therefore we may
take the opportunity to remove the irq_seqno_barrier w/a for gen6+.
Although using the PIPECONTROL to write the breadcrumb is slower than
MI_STORE_DWORD_IMM, by combining the operations into one and removing the
extra flush (next patch) it is faster
For gen2-5, we simply combine the MI_FLUSH into the breadcrumb emission,
though maybe we could find a solution here to the seqno-vs-interrupt
issue on Ironlake by mixing up the flush? The answer is no, adding an
MI_FLUSH before the interrupt is insufficient.
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/intel_ringbuffer.c | 97 +++++++++++++++++++++++--
1 file changed, 91 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index d5a9edbcf1be..eb3701fdeab6 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -217,7 +217,7 @@ gen4_render_ring_flush(struct i915_request *rq, u32 mode)
* really our business. That leaves only stall at scoreboard.
*/
static int
-intel_emit_post_sync_nonzero_flush(struct i915_request *rq)
+gen6_emit_post_sync_nonzero_flush(struct i915_request *rq)
{
u32 scratch_addr = i915_scratch_offset(rq->i915) + 2 * CACHELINE_BYTES;
u32 *cs;
@@ -257,7 +257,7 @@ gen6_render_ring_flush(struct i915_request *rq, u32 mode)
int ret;
/* Force SNB workarounds for PIPE_CONTROL flushes */
- ret = intel_emit_post_sync_nonzero_flush(rq);
+ ret = gen6_emit_post_sync_nonzero_flush(rq);
if (ret)
return ret;
@@ -300,6 +300,37 @@ gen6_render_ring_flush(struct i915_request *rq, u32 mode)
return 0;
}
+static void gen6_rcs_emit_breadcrumb(struct i915_request *rq, u32 *cs)
+{
+ /* First we do the gen6_emit_post_sync_nonzero_flush w/a */
+ *cs++ = GFX_OP_PIPE_CONTROL(4);
+ *cs++ = PIPE_CONTROL_CS_STALL | PIPE_CONTROL_STALL_AT_SCOREBOARD;
+ *cs++ = 0;
+ *cs++ = 0;
+
+ *cs++ = GFX_OP_PIPE_CONTROL(4);
+ *cs++ = PIPE_CONTROL_QW_WRITE;
+ *cs++ = i915_scratch_offset(rq->i915) | PIPE_CONTROL_GLOBAL_GTT;
+ *cs++ = 0;
+
+ /* Finally we can flush and with it emit the breadcrumb */
+ *cs++ = GFX_OP_PIPE_CONTROL(4);
+ *cs++ = (PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH |
+ PIPE_CONTROL_DEPTH_CACHE_FLUSH |
+ PIPE_CONTROL_DC_FLUSH_ENABLE |
+ PIPE_CONTROL_QW_WRITE |
+ PIPE_CONTROL_CS_STALL);
+ *cs++ = intel_hws_seqno_address(rq->engine) | PIPE_CONTROL_GLOBAL_GTT;
+ *cs++ = rq->global_seqno;
+
+ *cs++ = MI_USER_INTERRUPT;
+ *cs++ = MI_NOOP;
+
+ rq->tail = intel_ring_offset(rq, cs);
+ assert_ring_tail_valid(rq->ring, rq->tail);
+}
+static const int gen6_rcs_emit_breadcrumb_sz = 14;
+
static int
gen7_render_ring_cs_stall_wa(struct i915_request *rq)
{
@@ -379,6 +410,39 @@ gen7_render_ring_flush(struct i915_request *rq, u32 mode)
return 0;
}
+static void gen7_rcs_emit_breadcrumb(struct i915_request *rq, u32 *cs)
+{
+ *cs++ = GFX_OP_PIPE_CONTROL(4);
+ *cs++ = (PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH |
+ PIPE_CONTROL_DEPTH_CACHE_FLUSH |
+ PIPE_CONTROL_DC_FLUSH_ENABLE |
+ PIPE_CONTROL_FLUSH_ENABLE |
+ PIPE_CONTROL_QW_WRITE |
+ PIPE_CONTROL_GLOBAL_GTT_IVB |
+ PIPE_CONTROL_CS_STALL);
+ *cs++ = intel_hws_seqno_address(rq->engine);
+ *cs++ = rq->global_seqno;
+
+ *cs++ = MI_USER_INTERRUPT;
+ *cs++ = MI_NOOP;
+
+ rq->tail = intel_ring_offset(rq, cs);
+ assert_ring_tail_valid(rq->ring, rq->tail);
+}
+static const int gen7_rcs_emit_breadcrumb_sz = 6;
+
+static void gen6_xcs_emit_breadcrumb(struct i915_request *rq, u32 *cs)
+{
+ *cs++ = MI_FLUSH_DW | MI_FLUSH_DW_OP_STOREDW;
+ *cs++ = intel_hws_seqno_address(rq->engine) | MI_FLUSH_DW_USE_GTT;
+ *cs++ = rq->global_seqno;
+ *cs++ = MI_USER_INTERRUPT;
+
+ rq->tail = intel_ring_offset(rq, cs);
+ assert_ring_tail_valid(rq->ring, rq->tail);
+}
+static const int gen6_xcs_emit_breadcrumb_sz = 4;
+
static void set_hwstam(struct intel_engine_cs *engine, u32 mask)
{
/*
@@ -777,6 +841,9 @@ static void i9xx_submit_request(struct i915_request *request)
static void i9xx_emit_breadcrumb(struct i915_request *rq, u32 *cs)
{
+ *cs++ = MI_FLUSH;
+ *cs++ = MI_NOOP;
+
*cs++ = MI_STORE_DWORD_INDEX;
*cs++ = I915_GEM_HWS_INDEX << MI_STORE_DWORD_INDEX_SHIFT;
*cs++ = rq->global_seqno;
@@ -786,7 +853,7 @@ static void i9xx_emit_breadcrumb(struct i915_request *rq, u32 *cs)
assert_ring_tail_valid(rq->ring, rq->tail);
}
-static const int i9xx_emit_breadcrumb_sz = 4;
+static const int i9xx_emit_breadcrumb_sz = 6;
static void
gen5_seqno_barrier(struct intel_engine_cs *engine)
@@ -2122,11 +2189,16 @@ int intel_init_render_ring_buffer(struct intel_engine_cs *engine)
engine->irq_enable_mask = GT_RENDER_USER_INTERRUPT;
- if (INTEL_GEN(dev_priv) >= 6) {
+ if (INTEL_GEN(dev_priv) >= 7) {
engine->init_context = intel_rcs_ctx_init;
engine->emit_flush = gen7_render_ring_flush;
- if (IS_GEN(dev_priv, 6))
- engine->emit_flush = gen6_render_ring_flush;
+ engine->emit_breadcrumb = gen7_rcs_emit_breadcrumb;
+ engine->emit_breadcrumb_sz = gen7_rcs_emit_breadcrumb_sz;
+ } else if (IS_GEN(dev_priv, 6)) {
+ engine->init_context = intel_rcs_ctx_init;
+ engine->emit_flush = gen6_render_ring_flush;
+ engine->emit_breadcrumb = gen6_rcs_emit_breadcrumb;
+ engine->emit_breadcrumb_sz = gen6_rcs_emit_breadcrumb_sz;
} else if (IS_GEN(dev_priv, 5)) {
engine->emit_flush = gen4_render_ring_flush;
} else {
@@ -2161,6 +2233,9 @@ int intel_init_bsd_ring_buffer(struct intel_engine_cs *engine)
engine->set_default_submission = gen6_bsd_set_default_submission;
engine->emit_flush = gen6_bsd_ring_flush;
engine->irq_enable_mask = GT_BSD_USER_INTERRUPT;
+
+ engine->emit_breadcrumb = gen6_xcs_emit_breadcrumb;
+ engine->emit_breadcrumb_sz = gen6_xcs_emit_breadcrumb_sz;
} else {
engine->emit_flush = bsd_ring_flush;
if (IS_GEN(dev_priv, 5))
@@ -2176,11 +2251,16 @@ int intel_init_blt_ring_buffer(struct intel_engine_cs *engine)
{
struct drm_i915_private *dev_priv = engine->i915;
+ GEM_BUG_ON(INTEL_GEN(dev_priv) < 6);
+
intel_ring_default_vfuncs(dev_priv, engine);
engine->emit_flush = gen6_ring_flush;
engine->irq_enable_mask = GT_BLT_USER_INTERRUPT;
+ engine->emit_breadcrumb = gen6_xcs_emit_breadcrumb;
+ engine->emit_breadcrumb_sz = gen6_xcs_emit_breadcrumb_sz;
+
return intel_init_ring_buffer(engine);
}
@@ -2188,6 +2268,8 @@ int intel_init_vebox_ring_buffer(struct intel_engine_cs *engine)
{
struct drm_i915_private *dev_priv = engine->i915;
+ GEM_BUG_ON(INTEL_GEN(dev_priv) < 7);
+
intel_ring_default_vfuncs(dev_priv, engine);
engine->emit_flush = gen6_ring_flush;
@@ -2195,5 +2277,8 @@ int intel_init_vebox_ring_buffer(struct intel_engine_cs *engine)
engine->irq_enable = hsw_vebox_irq_enable;
engine->irq_disable = hsw_vebox_irq_disable;
+ engine->emit_breadcrumb = gen6_xcs_emit_breadcrumb;
+ engine->emit_breadcrumb_sz = gen6_xcs_emit_breadcrumb_sz;
+
return intel_init_ring_buffer(engine);
}
--
2.20.0
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