[PATCH 18/28] drm/i915: Track the context's seqno in its own timeline HWSP
Chris Wilson
chris at chris-wilson.co.uk
Sat Jan 19 22:35:27 UTC 2019
Now that we have allocated ourselves a cacheline to store a breadcrumb,
we can emit a write from the GPU into the timeline's HWSP of the
per-context seqno as we complete each request. This drops the mirroring
of the per-engine HWSP and allows each context to operate independently.
We do not need to unwind the per-context timeline, and so requests are
always consistent with the timeline breadcrumb, greatly simplifying the
completion checks as we no longer need to be concerned about the
global_seqno changing mid check.
One complication though is that we have to be wary that the request may
outlive the HWSP and so avoid touching the potentially danging pointer
after we have retired the fence. We also have to guard our access of the
HWSP with RCU, the release of the obj->mm.pages should already be RCU-safe.
At this point, we are emitting both per-context and global seqno and
still using the single per-engine execution timeline for resolving
interrupts.
v2: s/fake_complete/mark_complete/ (applied earlier)
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
drivers/gpu/drm/i915/i915_gem.c | 2 +-
drivers/gpu/drm/i915/i915_request.c | 2 +-
drivers/gpu/drm/i915/i915_request.h | 32 +++----
drivers/gpu/drm/i915/i915_vma.h | 7 ++
drivers/gpu/drm/i915/intel_lrc.c | 30 ++++---
drivers/gpu/drm/i915/intel_ringbuffer.c | 89 +++++++++++++++-----
drivers/gpu/drm/i915/selftests/mock_engine.c | 15 ++--
7 files changed, 115 insertions(+), 62 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 97b90dc6e03e..66cd0fe28064 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2890,7 +2890,7 @@ i915_gem_find_active_request(struct intel_engine_cs *engine)
*/
spin_lock_irqsave(&engine->timeline.lock, flags);
list_for_each_entry(request, &engine->timeline.requests, link) {
- if (__i915_request_completed(request, request->global_seqno))
+ if (i915_request_completed(request))
continue;
active = request;
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 671ce57ee369..b6048a1a79c2 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -622,7 +622,7 @@ i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx)
rq->ring = ce->ring;
rq->timeline = ce->ring->timeline;
GEM_BUG_ON(rq->timeline == &engine->timeline);
- rq->hwsp_seqno = &engine->status_page.addr[I915_GEM_HWS_INDEX];
+ rq->hwsp_seqno = rq->timeline->hwsp_seqno;
spin_lock_init(&rq->lock);
dma_fence_init(&rq->fence,
diff --git a/drivers/gpu/drm/i915/i915_request.h b/drivers/gpu/drm/i915/i915_request.h
index 5a08c84afed1..852e7cd985cd 100644
--- a/drivers/gpu/drm/i915/i915_request.h
+++ b/drivers/gpu/drm/i915/i915_request.h
@@ -324,6 +324,12 @@ static inline u32 hwsp_seqno(const struct i915_request *rq)
return seqno;
}
+static inline bool i915_request_signaled(const struct i915_request *rq)
+{
+ /* The request may live longer than its HWSP, so check flags first! */
+ return test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &rq->fence.flags);
+}
+
/**
* i915_request_started - check if the request has begun being executed
* @rq: the request
@@ -335,32 +341,18 @@ static inline u32 hwsp_seqno(const struct i915_request *rq)
*/
static inline bool i915_request_started(const struct i915_request *rq)
{
- u32 seqno;
-
- seqno = i915_request_global_seqno(rq);
- if (!seqno) /* not yet submitted to HW */
- return false;
+ if (i915_request_signaled(rq))
+ return true;
- return i915_seqno_passed(hwsp_seqno(rq), seqno - 1);
-}
-
-static inline bool
-__i915_request_completed(const struct i915_request *rq, u32 seqno)
-{
- GEM_BUG_ON(!seqno);
- return i915_seqno_passed(hwsp_seqno(rq), seqno) &&
- seqno == i915_request_global_seqno(rq);
+ return i915_seqno_passed(hwsp_seqno(rq), rq->fence.seqno - 1);
}
static inline bool i915_request_completed(const struct i915_request *rq)
{
- u32 seqno;
-
- seqno = i915_request_global_seqno(rq);
- if (!seqno)
- return false;
+ if (i915_request_signaled(rq))
+ return true;
- return __i915_request_completed(rq, seqno);
+ return i915_seqno_passed(hwsp_seqno(rq), rq->fence.seqno);
}
static inline void i915_request_mark_complete(struct i915_request *rq)
diff --git a/drivers/gpu/drm/i915/i915_vma.h b/drivers/gpu/drm/i915/i915_vma.h
index 5793abe509a2..18be786a970d 100644
--- a/drivers/gpu/drm/i915/i915_vma.h
+++ b/drivers/gpu/drm/i915/i915_vma.h
@@ -221,6 +221,13 @@ static inline u32 i915_ggtt_offset(const struct i915_vma *vma)
return lower_32_bits(vma->node.start);
}
+/* XXX inline spaghetti */
+static inline u32 i915_timeline_seqno_address(const struct i915_timeline *tl)
+{
+ GEM_BUG_ON(!tl->pin_count);
+ return i915_ggtt_offset(tl->hwsp_ggtt) + tl->hwsp_offset;
+}
+
static inline u32 i915_ggtt_pin_bias(struct i915_vma *vma)
{
return i915_vm_to_ggtt(vma->vm)->pin_bias;
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 085b2b21a5a2..e6b5e19b191e 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -838,10 +838,9 @@ static void execlists_cancel_requests(struct intel_engine_cs *engine)
list_for_each_entry(rq, &engine->timeline.requests, link) {
GEM_BUG_ON(!rq->global_seqno);
- if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &rq->fence.flags))
- continue;
+ if (!test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &rq->fence.flags))
+ dma_fence_set_error(&rq->fence, -EIO);
- dma_fence_set_error(&rq->fence, -EIO);
i915_request_mark_complete(rq);
}
@@ -2038,31 +2037,40 @@ static void gen8_emit_breadcrumb(struct i915_request *request, u32 *cs)
/* w/a: bit 5 needs to be zero for MI_FLUSH_DW address. */
BUILD_BUG_ON(I915_GEM_HWS_INDEX_ADDR & (1 << 5));
- cs = gen8_emit_ggtt_write(cs, request->global_seqno,
+ cs = gen8_emit_ggtt_write(cs,
+ request->fence.seqno,
+ i915_timeline_seqno_address(request->timeline));
+
+ cs = gen8_emit_ggtt_write(cs,
+ request->global_seqno,
intel_hws_seqno_address(request->engine));
+
*cs++ = MI_USER_INTERRUPT;
*cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE;
+
request->tail = intel_ring_offset(request, cs);
assert_ring_tail_valid(request->ring, request->tail);
gen8_emit_wa_tail(request, cs);
}
-static const int gen8_emit_breadcrumb_sz = 6 + WA_TAIL_DWORDS;
+static const int gen8_emit_breadcrumb_sz = 10 + WA_TAIL_DWORDS;
static void gen8_emit_breadcrumb_rcs(struct i915_request *request, u32 *cs)
{
- /* We're using qword write, seqno should be aligned to 8 bytes. */
- BUILD_BUG_ON(I915_GEM_HWS_INDEX & 1);
-
cs = gen8_emit_ggtt_write_rcs(cs,
- request->global_seqno,
- intel_hws_seqno_address(request->engine),
+ request->fence.seqno,
+ i915_timeline_seqno_address(request->timeline),
PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH |
PIPE_CONTROL_DEPTH_CACHE_FLUSH |
PIPE_CONTROL_DC_FLUSH_ENABLE |
PIPE_CONTROL_FLUSH_ENABLE |
PIPE_CONTROL_CS_STALL);
+ cs = gen8_emit_ggtt_write_rcs(cs,
+ request->global_seqno,
+ intel_hws_seqno_address(request->engine),
+ PIPE_CONTROL_CS_STALL);
+
*cs++ = MI_USER_INTERRUPT;
*cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE;
@@ -2071,7 +2079,7 @@ static void gen8_emit_breadcrumb_rcs(struct i915_request *request, u32 *cs)
gen8_emit_wa_tail(request, cs);
}
-static const int gen8_emit_breadcrumb_rcs_sz = 8 + WA_TAIL_DWORDS;
+static const int gen8_emit_breadcrumb_rcs_sz = 14 + WA_TAIL_DWORDS;
static int gen8_init_rcs_context(struct i915_request *rq)
{
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index bf8b648a79e1..da8d4eab085e 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -326,6 +326,12 @@ static void gen6_rcs_emit_breadcrumb(struct i915_request *rq, u32 *cs)
PIPE_CONTROL_DC_FLUSH_ENABLE |
PIPE_CONTROL_QW_WRITE |
PIPE_CONTROL_CS_STALL);
+ *cs++ = i915_timeline_seqno_address(rq->timeline) |
+ PIPE_CONTROL_GLOBAL_GTT;
+ *cs++ = rq->fence.seqno;
+
+ *cs++ = GFX_OP_PIPE_CONTROL(4);
+ *cs++ = PIPE_CONTROL_QW_WRITE | PIPE_CONTROL_CS_STALL;
*cs++ = intel_hws_seqno_address(rq->engine) | PIPE_CONTROL_GLOBAL_GTT;
*cs++ = rq->global_seqno;
@@ -335,7 +341,7 @@ static void gen6_rcs_emit_breadcrumb(struct i915_request *rq, u32 *cs)
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 const int gen6_rcs_emit_breadcrumb_sz = 18;
static int
gen7_render_ring_cs_stall_wa(struct i915_request *rq)
@@ -426,6 +432,13 @@ static void gen7_rcs_emit_breadcrumb(struct i915_request *rq, u32 *cs)
PIPE_CONTROL_QW_WRITE |
PIPE_CONTROL_GLOBAL_GTT_IVB |
PIPE_CONTROL_CS_STALL);
+ *cs++ = i915_timeline_seqno_address(rq->timeline);
+ *cs++ = rq->fence.seqno;
+
+ *cs++ = GFX_OP_PIPE_CONTROL(4);
+ *cs++ = (PIPE_CONTROL_QW_WRITE |
+ PIPE_CONTROL_GLOBAL_GTT_IVB |
+ PIPE_CONTROL_CS_STALL);
*cs++ = intel_hws_seqno_address(rq->engine);
*cs++ = rq->global_seqno;
@@ -435,27 +448,37 @@ static void gen7_rcs_emit_breadcrumb(struct i915_request *rq, u32 *cs)
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 const int gen7_rcs_emit_breadcrumb_sz = 10;
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++ = MI_FLUSH_DW | MI_FLUSH_DW_OP_STOREDW | MI_FLUSH_DW_STORE_INDEX;
+ *cs++ = I915_GEM_HWS_SEQNO_ADDR | MI_FLUSH_DW_USE_GTT;
+ *cs++ = rq->fence.seqno;
+
+ *cs++ = MI_FLUSH_DW | MI_FLUSH_DW_OP_STOREDW | MI_FLUSH_DW_STORE_INDEX;
+ *cs++ = I915_GEM_HWS_INDEX_ADDR | MI_FLUSH_DW_USE_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_xcs_emit_breadcrumb_sz = 4;
+static const int gen6_xcs_emit_breadcrumb_sz = 8;
#define GEN7_XCS_WA 32
static void gen7_xcs_emit_breadcrumb(struct i915_request *rq, u32 *cs)
{
int i;
- *cs++ = MI_FLUSH_DW | MI_FLUSH_DW_OP_STOREDW;
- *cs++ = intel_hws_seqno_address(rq->engine) | MI_FLUSH_DW_USE_GTT;
+ *cs++ = MI_FLUSH_DW | MI_FLUSH_DW_OP_STOREDW | MI_FLUSH_DW_STORE_INDEX;
+ *cs++ = I915_GEM_HWS_SEQNO_ADDR | MI_FLUSH_DW_USE_GTT;
+ *cs++ = rq->fence.seqno;
+
+ *cs++ = MI_FLUSH_DW | MI_FLUSH_DW_OP_STOREDW | MI_FLUSH_DW_STORE_INDEX;
+ *cs++ = I915_GEM_HWS_INDEX_ADDR | MI_FLUSH_DW_USE_GTT;
*cs++ = rq->global_seqno;
for (i = 0; i < GEN7_XCS_WA; i++) {
@@ -469,12 +492,11 @@ static void gen7_xcs_emit_breadcrumb(struct i915_request *rq, u32 *cs)
*cs++ = 0;
*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_xcs_emit_breadcrumb_sz = 8 + GEN7_XCS_WA * 3;
+static const int gen7_xcs_emit_breadcrumb_sz = 10 + GEN7_XCS_WA * 3;
#undef GEN7_XCS_WA
static void set_hwstam(struct intel_engine_cs *engine, u32 mask)
@@ -734,7 +756,7 @@ static void reset_ring(struct intel_engine_cs *engine, bool stalled)
rq = NULL;
spin_lock_irqsave(&tl->lock, flags);
list_for_each_entry(pos, &tl->requests, link) {
- if (!__i915_request_completed(pos, pos->global_seqno)) {
+ if (!i915_request_completed(pos)) {
rq = pos;
break;
}
@@ -876,11 +898,10 @@ static void cancel_requests(struct intel_engine_cs *engine)
list_for_each_entry(request, &engine->timeline.requests, link) {
GEM_BUG_ON(!request->global_seqno);
- if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT,
- &request->fence.flags))
- continue;
+ if (!test_bit(DMA_FENCE_FLAG_SIGNALED_BIT,
+ &request->fence.flags))
+ dma_fence_set_error(&request->fence, -EIO);
- dma_fence_set_error(&request->fence, -EIO);
i915_request_mark_complete(request);
}
@@ -905,27 +926,38 @@ static void i9xx_submit_request(struct i915_request *request)
static void i9xx_emit_breadcrumb(struct i915_request *rq, u32 *cs)
{
+ GEM_BUG_ON(rq->timeline->hwsp_ggtt != rq->engine->status_page.vma);
+
*cs++ = MI_FLUSH;
+ *cs++ = MI_STORE_DWORD_INDEX;
+ *cs++ = I915_GEM_HWS_SEQNO_ADDR;
+ *cs++ = rq->fence.seqno;
+
*cs++ = MI_STORE_DWORD_INDEX;
*cs++ = I915_GEM_HWS_INDEX_ADDR;
*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 i9xx_emit_breadcrumb_sz = 6;
+static const int i9xx_emit_breadcrumb_sz = 8;
#define GEN5_WA_STORES 8 /* must be at least 1! */
static void gen5_emit_breadcrumb(struct i915_request *rq, u32 *cs)
{
int i;
+ GEM_BUG_ON(rq->timeline->hwsp_ggtt != rq->engine->status_page.vma);
+
*cs++ = MI_FLUSH;
+ *cs++ = MI_STORE_DWORD_INDEX;
+ *cs++ = I915_GEM_HWS_SEQNO_ADDR;
+ *cs++ = rq->fence.seqno;
+
BUILD_BUG_ON(GEN5_WA_STORES < 1);
for (i = 0; i < GEN5_WA_STORES; i++) {
*cs++ = MI_STORE_DWORD_INDEX;
@@ -934,11 +966,12 @@ static void gen5_emit_breadcrumb(struct i915_request *rq, u32 *cs)
}
*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 gen5_emit_breadcrumb_sz = GEN5_WA_STORES * 3 + 2;
+static const int gen5_emit_breadcrumb_sz = GEN5_WA_STORES * 3 + 6;
#undef GEN5_WA_STORES
static void
@@ -1165,6 +1198,10 @@ int intel_ring_pin(struct intel_ring *ring)
GEM_BUG_ON(ring->vaddr);
+ ret = i915_timeline_pin(ring->timeline);
+ if (ret)
+ return ret;
+
flags = PIN_GLOBAL;
/* Ring wraparound at offset 0 sometimes hangs. No idea why. */
@@ -1181,28 +1218,32 @@ int intel_ring_pin(struct intel_ring *ring)
else
ret = i915_gem_object_set_to_cpu_domain(vma->obj, true);
if (unlikely(ret))
- return ret;
+ goto unpin_timeline;
}
ret = i915_vma_pin(vma, 0, 0, flags);
if (unlikely(ret))
- return ret;
+ goto unpin_timeline;
if (i915_vma_is_map_and_fenceable(vma))
addr = (void __force *)i915_vma_pin_iomap(vma);
else
addr = i915_gem_object_pin_map(vma->obj, map);
- if (IS_ERR(addr))
- goto err;
+ if (IS_ERR(addr)) {
+ ret = PTR_ERR(addr);
+ goto unpin_ring;
+ }
vma->obj->pin_global++;
ring->vaddr = addr;
return 0;
-err:
+unpin_ring:
i915_vma_unpin(vma);
- return PTR_ERR(addr);
+unpin_timeline:
+ i915_timeline_unpin(ring->timeline);
+ return ret;
}
void intel_ring_reset(struct intel_ring *ring, u32 tail)
@@ -1231,6 +1272,8 @@ void intel_ring_unpin(struct intel_ring *ring)
ring->vma->obj->pin_global--;
i915_vma_unpin(ring->vma);
+
+ i915_timeline_unpin(ring->timeline);
}
static struct i915_vma *
diff --git a/drivers/gpu/drm/i915/selftests/mock_engine.c b/drivers/gpu/drm/i915/selftests/mock_engine.c
index 2d0363c554fb..19ea2544aca1 100644
--- a/drivers/gpu/drm/i915/selftests/mock_engine.c
+++ b/drivers/gpu/drm/i915/selftests/mock_engine.c
@@ -113,6 +113,7 @@ static void hw_delay_complete(struct timer_list *t)
static void mock_context_unpin(struct intel_context *ce)
{
+ i915_timeline_unpin(ce->ring->timeline);
i915_gem_context_put(ce->gem_context);
}
@@ -134,6 +135,7 @@ mock_context_pin(struct intel_engine_cs *engine,
struct i915_gem_context *ctx)
{
struct intel_context *ce = to_intel_context(ctx, engine);
+ int err = -ENOMEM;
if (ce->pin_count++)
return ce;
@@ -144,13 +146,17 @@ mock_context_pin(struct intel_engine_cs *engine,
goto err;
}
+ err = i915_timeline_pin(ce->ring->timeline);
+ if (err)
+ goto err;
+
ce->ops = &mock_context_ops;
i915_gem_context_get(ctx);
return ce;
err:
ce->pin_count = 0;
- return ERR_PTR(-ENOMEM);
+ return ERR_PTR(err);
}
static int mock_request_alloc(struct i915_request *request)
@@ -254,16 +260,13 @@ void mock_engine_flush(struct intel_engine_cs *engine)
del_timer_sync(&mock->hw_delay);
spin_lock_irq(&mock->hw_lock);
- list_for_each_entry_safe(request, rn, &mock->hw_queue, link) {
- list_del_init(&request->link);
- mock_seqno_advance(&mock->base, request->base.global_seqno);
- }
+ list_for_each_entry_safe(request, rn, &mock->hw_queue, link)
+ advance(mock, request);
spin_unlock_irq(&mock->hw_lock);
}
void mock_engine_reset(struct intel_engine_cs *engine)
{
- intel_write_status_page(engine, I915_GEM_HWS_INDEX, 0);
}
void mock_engine_free(struct intel_engine_cs *engine)
--
2.20.1
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