[PATCH 3/6] drm/amdgpu: Add helper function to get sdma index

[Rex Zhu]

Get the sdma index from sdma ring

Signed-off-by: Rex Zhu <Rex.Zhu at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c | 16 ++++++++++++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h |  1 +
 2 files changed, 17 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
index 0fb9907..99668a5 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
@@ -40,3 +40,19 @@ struct amdgpu_sdma_instance * amdgpu_get_sdma_instance(struct amdgpu_ring *ring)
 
 	return NULL;
 }
+
+int amdgpu_get_sdma_index(struct amdgpu_ring *ring, uint32_t *index)
+{
+	struct amdgpu_device *adev = ring->adev;
+	int i;
+
+	for (i = 0; i < adev->sdma.num_instances; i++) {
+		if (ring == &adev->sdma.instance[i].ring ||
+			ring == &adev->sdma.instance[i].page) {
+			*index = i;
+			return 0;
+		}
+	}
+
+	return -EINVAL;
+}
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h
index 237a357..92e5097 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h
@@ -96,5 +96,6 @@ struct amdgpu_buffer_funcs {
 
 struct amdgpu_sdma_instance *
 amdgpu_get_sdma_instance(struct amdgpu_ring *ring);
+int amdgpu_get_sdma_index(struct amdgpu_ring *ring, uint32_t *index);
 
 #endif
-- 
1.9.1