[PATCH 1/4] drm/amdgpu: don't reemit ring contents more than once

[PATCH 1/4] drm/amdgpu: don't reemit ring contents more than once

[Alex Deucher]

If we cancel a bad job and reemit the ring contents, and
we get another timeout, cancel everything rather than reemitting.
The wptr markers are only relevant for the original emit.  If
we reemit, the wptr markers are no longer correct.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c | 22 +++++++++++++++++-----
 drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h  |  2 ++
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
index 1fe31d2f27060..334ddd6e48c06 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
@@ -710,6 +710,7 @@ void amdgpu_fence_driver_guilty_force_completion(struct amdgpu_fence *af)
 	struct amdgpu_ring *ring = af->ring;
 	unsigned long flags;
 	u32 seq, last_seq;
+	bool reemitted = false;
 
 	last_seq = amdgpu_fence_read(ring) & ring->fence_drv.num_fences_mask;
 	seq = ring->fence_drv.sync_seq & ring->fence_drv.num_fences_mask;
@@ -727,7 +728,9 @@ void amdgpu_fence_driver_guilty_force_completion(struct amdgpu_fence *af)
 		if (unprocessed && !dma_fence_is_signaled_locked(unprocessed)) {
 			fence = container_of(unprocessed, struct amdgpu_fence, base);
 
-			if (fence == af)
+			if (fence->reemitted > 1)
+				reemitted = true;
+			else if (fence == af)
 				dma_fence_set_error(&fence->base, -ETIME);
 			else if (fence->context == af->context)
 				dma_fence_set_error(&fence->base, -ECANCELED);
@@ -735,9 +738,16 @@ void amdgpu_fence_driver_guilty_force_completion(struct amdgpu_fence *af)
 		rcu_read_unlock();
 	} while (last_seq != seq);
 	spin_unlock_irqrestore(&ring->fence_drv.lock, flags);
-	/* signal the guilty fence */
-	amdgpu_fence_write(ring, (u32)af->base.seqno);
-	amdgpu_fence_process(ring);
+
+	if (reemitted) {
+		/* if we've already reemitted once then just cancel everything */
+		amdgpu_fence_driver_force_completion(af->ring);
+		af->ring->ring_backup_entries_to_copy = 0;
+	} else {
+		/* signal the guilty fence */
+		amdgpu_fence_write(ring, (u32)af->base.seqno);
+		amdgpu_fence_process(ring);
+	}
 }
 
 void amdgpu_fence_save_wptr(struct amdgpu_fence *af)
@@ -785,10 +795,12 @@ void amdgpu_ring_backup_unprocessed_commands(struct amdgpu_ring *ring,
 			/* save everything if the ring is not guilty, otherwise
 			 * just save the content from other contexts.
 			 */
-			if (!guilty_fence || (fence->context != guilty_fence->context))
+			if (!fence->reemitted &&
+			    (!guilty_fence || (fence->context != guilty_fence->context)))
 				amdgpu_ring_backup_unprocessed_command(ring, wptr,
 								       fence->wptr);
 			wptr = fence->wptr;
+			fence->reemitted++;
 		}
 		rcu_read_unlock();
 	} while (last_seq != seq);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
index a1fb0fadb6eab..d881829528976 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
@@ -150,6 +150,8 @@ struct amdgpu_fence {
 	u64				wptr;
 	/* fence context for resets */
 	u64				context;
+	/* has this fence been reemitted */
+	unsigned int			reemitted;
 };
 
 extern const struct drm_sched_backend_ops amdgpu_sched_ops;
-- 
2.52.0

[PATCH 2/4] drm/amdgpu: always backup and reemit fences

[Alex Deucher]

If when we backup the ring contents for reemit before a
ring reset, we skip jobs associated with the bad
context, however, we need to make sure the fences
are reemited as unprocessed submissions may depend on
them.

v2: clean up fence handling, make helpers static

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c | 24 ++++++++++++++++++-----
 drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h  |  5 ++++-
 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
index 334ddd6e48c06..3a23cce5f769a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
@@ -89,6 +89,16 @@ static u32 amdgpu_fence_read(struct amdgpu_ring *ring)
 	return seq;
 }
 
+static void amdgpu_fence_save_fence_wptr_start(struct amdgpu_fence *af)
+{
+	af->fence_wptr_start = af->ring->wptr;
+}
+
+static void amdgpu_fence_save_fence_wptr_end(struct amdgpu_fence *af)
+{
+	af->fence_wptr_end = af->ring->wptr;
+}
+
 /**
  * amdgpu_fence_emit - emit a fence on the requested ring
  *
@@ -116,8 +126,10 @@ int amdgpu_fence_emit(struct amdgpu_ring *ring, struct amdgpu_fence *af,
 		       &ring->fence_drv.lock,
 		       adev->fence_context + ring->idx, seq);
 
+	amdgpu_fence_save_fence_wptr_start(af);
 	amdgpu_ring_emit_fence(ring, ring->fence_drv.gpu_addr,
 			       seq, flags | AMDGPU_FENCE_FLAG_INT);
+	amdgpu_fence_save_fence_wptr_end(af);
 	amdgpu_fence_save_wptr(af);
 	pm_runtime_get_noresume(adev_to_drm(adev)->dev);
 	ptr = &ring->fence_drv.fences[seq & ring->fence_drv.num_fences_mask];
@@ -743,10 +755,6 @@ void amdgpu_fence_driver_guilty_force_completion(struct amdgpu_fence *af)
 		/* if we've already reemitted once then just cancel everything */
 		amdgpu_fence_driver_force_completion(af->ring);
 		af->ring->ring_backup_entries_to_copy = 0;
-	} else {
-		/* signal the guilty fence */
-		amdgpu_fence_write(ring, (u32)af->base.seqno);
-		amdgpu_fence_process(ring);
 	}
 }
 
@@ -796,9 +804,15 @@ void amdgpu_ring_backup_unprocessed_commands(struct amdgpu_ring *ring,
 			 * just save the content from other contexts.
 			 */
 			if (!fence->reemitted &&
-			    (!guilty_fence || (fence->context != guilty_fence->context)))
+			    (!guilty_fence || (fence->context != guilty_fence->context))) {
 				amdgpu_ring_backup_unprocessed_command(ring, wptr,
 								       fence->wptr);
+			} else if (!fence->reemitted) {
+				/* always save the fence */
+				amdgpu_ring_backup_unprocessed_command(ring,
+								       fence->fence_wptr_start,
+								       fence->fence_wptr_end);
+			}
 			wptr = fence->wptr;
 			fence->reemitted++;
 		}
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
index d881829528976..87c9df6c2ecfe 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
@@ -146,12 +146,15 @@ struct amdgpu_fence {
 	struct amdgpu_ring		*ring;
 	ktime_t				start_timestamp;
 
-	/* wptr for the fence for resets */
+	/* wptr for the total submission for resets */
 	u64				wptr;
 	/* fence context for resets */
 	u64				context;
 	/* has this fence been reemitted */
 	unsigned int			reemitted;
+	/* wptr for the fence for the submission */
+	u64				fence_wptr_start;
+	u64				fence_wptr_end;
 };
 
 extern const struct drm_sched_backend_ops amdgpu_sched_ops;
-- 
2.52.0

[PATCH 3/4] drm/amdgpu: mark fences with errors before ring reset

[Alex Deucher]

Mark fences with errors before we reset the rings as
we may end up signalling fences as part of the reset
sequence.  The error needs to be set before the fence
is signalled.  On GC10 and newer, this isn't a problem
since we don't signal any fences.  On GC9, we need to
signal the fence after the reset to unblock the recovery
sequence.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
index 1aee207b13524..fd7b0f955e4df 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
@@ -872,6 +872,10 @@ void amdgpu_ring_reset_helper_begin(struct amdgpu_ring *ring,
 	drm_sched_wqueue_stop(&ring->sched);
 	/* back up the non-guilty commands */
 	amdgpu_ring_backup_unprocessed_commands(ring, guilty_fence);
+	/* signal the guilty fence and set an error on all fences from the context */
+	if (guilty_fence)
+		amdgpu_fence_driver_guilty_force_completion(guilty_fence);
+
 }
 
 int amdgpu_ring_reset_helper_end(struct amdgpu_ring *ring,
@@ -885,9 +889,6 @@ int amdgpu_ring_reset_helper_end(struct amdgpu_ring *ring,
 	if (r)
 		return r;
 
-	/* signal the guilty fence and set an error on all fences from the context */
-	if (guilty_fence)
-		amdgpu_fence_driver_guilty_force_completion(guilty_fence);
 	/* Re-emit the non-guilty commands */
 	if (ring->ring_backup_entries_to_copy) {
 		amdgpu_ring_alloc_reemit(ring, ring->ring_backup_entries_to_copy);
-- 
2.52.0

[PATCH 4/4] drm/amdgpu/gfx9: Implement KGQ ring reset

[Alex Deucher]

GFX ring resets work differently on pre-GFX10 hardware since
there is no MQD managed by the scheduler.
For ring reset, you need issue the reset via CP_VMID_RESET
via KIQ or MMIO and submit the following to the gfx ring to
complete the reset:
1. EOP packet with EXEC bit set
2. WAIT_REG_MEM to wait for the fence
3. Clear CP_VMID_RESET to 0
4. EVENT_WRITE ENABLE_LEGACY_PIPELINE
5. EOP packet with EXEC bit set
6. WAIT_REG_MEM to wait for the fence
Once those commands have completed the reset should
be complete and the ring can accept new packets.

However, because we have a pipeline sync between jobs,
the PFP is waiting on the fence from the bad job to signal so
it can't process any of the packets in the reset sequence
until that pipeline sync clears.  To unblock the PFP, we
use the KIQ to signal the fence after we reset the queue.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c | 104 +++++++++++++++++++++++++-
 1 file changed, 101 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
index e6187be27385a..158c8bdb213bc 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
@@ -2409,8 +2409,10 @@ static int gfx_v9_0_sw_init(struct amdgpu_ip_block *ip_block)
 		amdgpu_get_soft_full_reset_mask(&adev->gfx.gfx_ring[0]);
 	adev->gfx.compute_supported_reset =
 		amdgpu_get_soft_full_reset_mask(&adev->gfx.compute_ring[0]);
-	if (!amdgpu_sriov_vf(adev) && !adev->debug_disable_gpu_ring_reset)
+	if (!amdgpu_sriov_vf(adev) && !adev->debug_disable_gpu_ring_reset) {
 		adev->gfx.compute_supported_reset |= AMDGPU_RESET_TYPE_PER_QUEUE;
+		adev->gfx.gfx_supported_reset |= AMDGPU_RESET_TYPE_PER_QUEUE;
+	}
 
 	r = amdgpu_gfx_kiq_init(adev, GFX9_MEC_HPD_SIZE, 0);
 	if (r) {
@@ -7174,6 +7176,103 @@ static void gfx_v9_ring_insert_nop(struct amdgpu_ring *ring, uint32_t num_nop)
 	amdgpu_ring_insert_nop(ring, num_nop - 1);
 }
 
+static void gfx_v9_0_ring_emit_wreg_me(struct amdgpu_ring *ring,
+				       uint32_t reg,
+				       uint32_t val)
+{
+	uint32_t cmd = 0;
+
+	switch (ring->funcs->type) {
+	case AMDGPU_RING_TYPE_KIQ:
+		cmd = (1 << 16); /* no inc addr */
+		break;
+	default:
+		cmd = WR_CONFIRM;
+		break;
+	}
+	amdgpu_ring_write(ring, PACKET3(PACKET3_WRITE_DATA, 3));
+	amdgpu_ring_write(ring, cmd);
+	amdgpu_ring_write(ring, reg);
+	amdgpu_ring_write(ring, 0);
+	amdgpu_ring_write(ring, val);
+}
+
+static void gfx_v9_0_ring_emit_event_write(struct amdgpu_ring *ring,
+					   uint32_t event_type,
+					   uint32_t event_index)
+{
+	amdgpu_ring_write(ring, PACKET3(PACKET3_EVENT_WRITE, 0));
+	amdgpu_ring_write(ring, EVENT_TYPE(event_type) |
+			  EVENT_INDEX(event_index));
+}
+
+static int gfx_v9_0_reset_kgq(struct amdgpu_ring *ring,
+			      unsigned int vmid,
+			      struct amdgpu_fence *timedout_fence)
+{
+	struct amdgpu_device *adev = ring->adev;
+	struct amdgpu_kiq *kiq = &adev->gfx.kiq[0];
+	struct amdgpu_ring *kiq_ring = &kiq->ring;
+	unsigned long flags;
+	u32 tmp;
+	int r;
+
+	amdgpu_ring_reset_helper_begin(ring, timedout_fence);
+
+	spin_lock_irqsave(&kiq->ring_lock, flags);
+
+	if (amdgpu_ring_alloc(kiq_ring, 5 + 5)) {
+		spin_unlock_irqrestore(&kiq->ring_lock, flags);
+		return -ENOMEM;
+	}
+
+	/* send the reset - 5 */
+	tmp = REG_SET_FIELD(0, CP_VMID_RESET, RESET_REQUEST, 1 << vmid);
+	gfx_v9_0_ring_emit_wreg(kiq_ring,
+				SOC15_REG_OFFSET(GC, 0, mmCP_VMID_RESET), tmp);
+	/* emit the fence to clear the pipeline sync - 5 */
+	gfx_v9_0_ring_emit_fence_kiq(kiq_ring, ring->fence_drv.gpu_addr,
+				     timedout_fence->base.seqno, 0);
+	amdgpu_ring_commit(kiq_ring);
+	r = amdgpu_ring_test_ring(kiq_ring);
+	spin_unlock_irqrestore(&kiq->ring_lock, flags);
+	if (r)
+		return r;
+
+	if (amdgpu_ring_alloc(ring, 8 + 7 + 5 + 2 + 8 + 7))
+		return -ENOMEM;
+	/* emit the fence to finish the reset - 8 */
+	ring->trail_seq++;
+	gfx_v9_0_ring_emit_fence(ring, ring->trail_fence_gpu_addr,
+				 ring->trail_seq, AMDGPU_FENCE_FLAG_EXEC);
+	/* wait for the fence - 7 */
+	gfx_v9_0_wait_reg_mem(ring, 0, 1, 0,
+			      lower_32_bits(ring->trail_fence_gpu_addr),
+			      upper_32_bits(ring->trail_fence_gpu_addr),
+			      ring->trail_seq, 0xffffffff, 4);
+	/* clear mmCP_VMID_RESET - 5 */
+	gfx_v9_0_ring_emit_wreg_me(ring,
+				   SOC15_REG_OFFSET(GC, 0, mmCP_VMID_RESET), 0);
+	/* event write ENABLE_LEGACY_PIPELINE - 2 */
+	gfx_v9_0_ring_emit_event_write(ring, ENABLE_LEGACY_PIPELINE, 0);
+	/* emit a regular fence - 8 */
+	ring->trail_seq++;
+	gfx_v9_0_ring_emit_fence(ring, ring->trail_fence_gpu_addr,
+				 ring->trail_seq, AMDGPU_FENCE_FLAG_EXEC);
+	/* wait for the fence - 7 */
+	gfx_v9_0_wait_reg_mem(ring, 1, 1, 0,
+			      lower_32_bits(ring->trail_fence_gpu_addr),
+			      upper_32_bits(ring->trail_fence_gpu_addr),
+			      ring->trail_seq, 0xffffffff, 4);
+	amdgpu_ring_commit(ring);
+	/* wait for the commands to complete */
+	r = amdgpu_ring_test_ring(ring);
+	if (r)
+		return r;
+
+	return amdgpu_ring_reset_helper_end(ring, timedout_fence);
+}
+
 static int gfx_v9_0_reset_kcq(struct amdgpu_ring *ring,
 			      unsigned int vmid,
 			      struct amdgpu_fence *timedout_fence)
@@ -7452,9 +7551,9 @@ static const struct amdgpu_ring_funcs gfx_v9_0_ring_funcs_gfx = {
 	.emit_wreg = gfx_v9_0_ring_emit_wreg,
 	.emit_reg_wait = gfx_v9_0_ring_emit_reg_wait,
 	.emit_reg_write_reg_wait = gfx_v9_0_ring_emit_reg_write_reg_wait,
-	.soft_recovery = gfx_v9_0_ring_soft_recovery,
 	.emit_mem_sync = gfx_v9_0_emit_mem_sync,
 	.emit_cleaner_shader = gfx_v9_0_ring_emit_cleaner_shader,
+	.reset = gfx_v9_0_reset_kgq,
 	.begin_use = amdgpu_gfx_enforce_isolation_ring_begin_use,
 	.end_use = amdgpu_gfx_enforce_isolation_ring_end_use,
 };
@@ -7553,7 +7652,6 @@ static const struct amdgpu_ring_funcs gfx_v9_0_ring_funcs_compute = {
 	.emit_wreg = gfx_v9_0_ring_emit_wreg,
 	.emit_reg_wait = gfx_v9_0_ring_emit_reg_wait,
 	.emit_reg_write_reg_wait = gfx_v9_0_ring_emit_reg_write_reg_wait,
-	.soft_recovery = gfx_v9_0_ring_soft_recovery,
 	.emit_mem_sync = gfx_v9_0_emit_mem_sync,
 	.emit_wave_limit = gfx_v9_0_emit_wave_limit,
 	.reset = gfx_v9_0_reset_kcq,
-- 
2.52.0