[RFC PATCH 1/2] drm/amdgpu: Introduce ring lock

[xinhui pan <xinhui.pan@amd.com>]

This is used for direct IB submission to ring.

Signed-off-by: xinhui pan <xinhui.pan@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c | 2 ++
 drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h | 1 +
 2 files changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
index ab2351ba9574..f97a28a49120 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
@@ -184,6 +184,8 @@ int amdgpu_ring_init(struct amdgpu_device *adev, struct amdgpu_ring *ring,
 	else if (ring == &adev->sdma.instance[0].page)
 		sched_hw_submission = 256;
 
+	mutex_init(&ring->lock);
+
 	if (ring->adev == NULL) {
 		if (adev->num_rings >= AMDGPU_MAX_RINGS)
 			return -EINVAL;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
index 4d380e79752c..544766429b5c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
@@ -215,6 +215,7 @@ struct amdgpu_ring {
 	struct amdgpu_fence_driver	fence_drv;
 	struct drm_gpu_scheduler	sched;
 
+	struct mutex		lock;
 	struct amdgpu_bo	*ring_obj;
 	volatile uint32_t	*ring;
 	unsigned		rptr_offs;
-- 
2.25.1