[PATCH 1/3] drm/amdgpu: Use spin_lock instead of mutex for KIQ

Shaoyun Liu Shaoyun.Liu at amd.com
Fri Jun 30 15:53:27 UTC 2017


KIQ read/write register will be called in atomic context so mutex can not be used

Change-Id: Ifa14293b3cdfcf74cd7930a4058154d0a7d7f97c
Signed-off-by: Shaoyun Liu <Shaoyun.Liu at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu.h      | 2 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c  | 2 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c | 8 ++++----
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index ab1dad2..a155206 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -955,7 +955,7 @@ struct amdgpu_mec {
 struct amdgpu_kiq {
 	u64			eop_gpu_addr;
 	struct amdgpu_bo	*eop_obj;
-	struct mutex		ring_mutex;
+	spinlock_t		ring_lock;
 	struct amdgpu_ring	ring;
 	struct amdgpu_irq_src	irq;
 };
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
index e26108a..e5e5541 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
@@ -184,7 +184,7 @@ int amdgpu_gfx_kiq_init_ring(struct amdgpu_device *adev,
 	struct amdgpu_kiq *kiq = &adev->gfx.kiq;
 	int r = 0;
 
-	mutex_init(&kiq->ring_mutex);
+	spin_lock_init(&kiq->ring_lock);
 
 	r = amdgpu_wb_get(adev, &adev->virt.reg_val_offs);
 	if (r)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
index 8a081e1..a65e76c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
@@ -122,12 +122,12 @@ uint32_t amdgpu_virt_kiq_rreg(struct amdgpu_device *adev, uint32_t reg)
 
 	BUG_ON(!ring->funcs->emit_rreg);
 
-	mutex_lock(&kiq->ring_mutex);
+	spin_lock(&kiq->ring_lock);
 	amdgpu_ring_alloc(ring, 32);
 	amdgpu_ring_emit_rreg(ring, reg);
 	amdgpu_fence_emit(ring, &f);
 	amdgpu_ring_commit(ring);
-	mutex_unlock(&kiq->ring_mutex);
+	spin_unlock(&kiq->ring_lock);
 
 	r = dma_fence_wait_timeout(f, false, msecs_to_jiffies(MAX_KIQ_REG_WAIT));
 	dma_fence_put(f);
@@ -150,12 +150,12 @@ void amdgpu_virt_kiq_wreg(struct amdgpu_device *adev, uint32_t reg, uint32_t v)
 
 	BUG_ON(!ring->funcs->emit_wreg);
 
-	mutex_lock(&kiq->ring_mutex);
+	spin_lock(&kiq->ring_lock);
 	amdgpu_ring_alloc(ring, 32);
 	amdgpu_ring_emit_wreg(ring, reg, v);
 	amdgpu_fence_emit(ring, &f);
 	amdgpu_ring_commit(ring);
-	mutex_unlock(&kiq->ring_mutex);
+	spin_unlock(&kiq->ring_lock);
 
 	r = dma_fence_wait_timeout(f, false, msecs_to_jiffies(MAX_KIQ_REG_WAIT));
 	if (r < 1)
-- 
1.9.1



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