[PATCH] drm/amdgpu: protect ring overrun

[Yintian Tao]

Wait for the oldest sequence on the ring
to be signaled in order to make sure there
will be no command overrun.

Signed-off-by: Yintian Tao <yttao at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c |  7 +++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c   | 17 +++++++++++++++--
 drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c  |  8 +++++++-
 drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c     |  9 ++++++++-
 drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c    |  8 +++++++-
 drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c     |  8 +++++++-
 6 files changed, 51 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
index 7531527067df..5462ea83d8b2 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
@@ -200,6 +200,13 @@ int amdgpu_fence_emit_polling(struct amdgpu_ring *ring, uint32_t *s)
 		return -EINVAL;
 
 	seq = ++ring->fence_drv.sync_seq;
+	if ((abs(seq - ring->fence_drv.num_fences_mask) >
+	    ring->fence_drv.num_fences_mask) &&
+	    (amdgpu_fence_wait_polling(ring,
+				       seq - ring->fence_drv.num_fences_mask,
+				       MAX_KIQ_REG_WAIT) < 1))
+		 return -ETIME;
+
 	amdgpu_ring_emit_fence(ring, ring->fence_drv.gpu_addr,
 			       seq, 0);
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
index a721b0e0ff69..7087333681f6 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
@@ -681,7 +681,14 @@ uint32_t amdgpu_kiq_rreg(struct amdgpu_device *adev, uint32_t reg)
 	}
 	amdgpu_ring_alloc(ring, 32);
 	amdgpu_ring_emit_rreg(ring, reg, reg_val_offs);
-	amdgpu_fence_emit_polling(ring, &seq);
+	r = amdgpu_fence_emit_polling(ring, &seq);
+	if (r) {
+		amdgpu_ring_undo(ring);
+		amdgpu_device_wb_free(adev, reg_val_offs);
+		spin_unlock_irqrestore(&kiq->ring_lock, flags);
+		goto failed_kiq_read;
+	}
+
 	amdgpu_ring_commit(ring);
 	spin_unlock_irqrestore(&kiq->ring_lock, flags);
 
@@ -730,7 +737,13 @@ void amdgpu_kiq_wreg(struct amdgpu_device *adev, uint32_t reg, uint32_t v)
 	spin_lock_irqsave(&kiq->ring_lock, flags);
 	amdgpu_ring_alloc(ring, 32);
 	amdgpu_ring_emit_wreg(ring, reg, v);
-	amdgpu_fence_emit_polling(ring, &seq);
+	r = amdgpu_fence_emit_polling(ring, &seq);
+	if (r) {
+		amdgpu_ring_undo(ring);
+		spin_unlock_irqrestore(&kiq->ring_lock, flags);
+		goto failed_kiq_write;
+	}
+
 	amdgpu_ring_commit(ring);
 	spin_unlock_irqrestore(&kiq->ring_lock, flags);
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
index 8c10084f44ef..12d181ac7e78 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
@@ -60,7 +60,13 @@ void amdgpu_virt_kiq_reg_write_reg_wait(struct amdgpu_device *adev,
 	amdgpu_ring_alloc(ring, 32);
 	amdgpu_ring_emit_reg_write_reg_wait(ring, reg0, reg1,
 					    ref, mask);
-	amdgpu_fence_emit_polling(ring, &seq);
+	r = amdgpu_fence_emit_polling(ring, &seq);
+	if (r) {
+		amdgpu_ring_undo(ring);
+		spin_unlock_irqrestore(&kiq->ring_lock, flags);
+		goto failed_kiq;
+	}
+
 	amdgpu_ring_commit(ring);
 	spin_unlock_irqrestore(&kiq->ring_lock, flags);
 
diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
index 5b1549f167b0..650b7a67d3bc 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
@@ -4068,7 +4068,14 @@ static uint64_t gfx_v9_0_kiq_read_clock(struct amdgpu_device *adev)
 				reg_val_offs * 4));
 	amdgpu_ring_write(ring, upper_32_bits(adev->wb.gpu_addr +
 				reg_val_offs * 4));
-	amdgpu_fence_emit_polling(ring, &seq);
+	r = amdgpu_fence_emit_polling(ring, &seq);
+	if (r) {
+		amdgpu_ring_undo(ring);
+		amdgpu_device_wb_free(adev, reg_val_offs);
+		spin_unlock_irqrestore(&kiq->ring_lock, flags);
+		goto failed_kiq_read;
+	}
+
 	amdgpu_ring_commit(ring);
 	spin_unlock_irqrestore(&kiq->ring_lock, flags);
 
diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c
index 30b75d79efdb..71430f2a2374 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c
@@ -427,7 +427,13 @@ static int gmc_v10_0_flush_gpu_tlb_pasid(struct amdgpu_device *adev,
 		amdgpu_ring_alloc(ring, kiq->pmf->invalidate_tlbs_size + 8);
 		kiq->pmf->kiq_invalidate_tlbs(ring,
 					pasid, flush_type, all_hub);
-		amdgpu_fence_emit_polling(ring, &seq);
+		r = amdgpu_fence_emit_polling(ring, &seq);
+		if (r) {
+			amdgpu_ring_undo(ring);
+			spin_unlock(&kiq->ring_lock);
+			return -ETIME;
+		}
+
 		amdgpu_ring_commit(ring);
 		spin_unlock(&adev->gfx.kiq.ring_lock);
 		r = amdgpu_fence_wait_polling(ring, seq, adev->usec_timeout);
diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
index fecdbc471983..a42a95675e2b 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
@@ -621,7 +621,13 @@ static int gmc_v9_0_flush_gpu_tlb_pasid(struct amdgpu_device *adev,
 						      pasid, 2, all_hub);
 		kiq->pmf->kiq_invalidate_tlbs(ring,
 					pasid, flush_type, all_hub);
-		amdgpu_fence_emit_polling(ring, &seq);
+		r = amdgpu_fence_emit_polling(ring, &seq);
+		if (r) {
+			amdgpu_ring_undo(ring);
+			spin_unlock(&kiq->ring_lock);
+			return -ETIME;
+		}
+
 		amdgpu_ring_commit(ring);
 		spin_unlock(&adev->gfx.kiq.ring_lock);
 		r = amdgpu_fence_wait_polling(ring, seq, adev->usec_timeout);
-- 
2.17.1