[PATCH 1/3] drm/amdgpu/sdma: add begin_use/end_use helpers

[Alex Deucher]

Add helper functions to disallow GFXOFF while SDMA has work.
This should avoid corner cases where GFXOFF is erroneously
entered when SDMA is still active.  For now just allow/disallow
GFXOFF in the begin and end helpers until we root cause the
issue.  This should not impact power as SDMA usage is pretty
minimal and GFXOSS should not be active when SDMA is active
anyway, this just makes it explicit.

Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c | 14 ++++++++++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h |  3 +++
 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 1d9d187de6ee..d4b08d03970c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
@@ -326,3 +326,17 @@ int amdgpu_sdma_ras_sw_init(struct amdgpu_device *adev)
 
 	return 0;
 }
+
+void amdgpu_sdma_ring_begin_use(struct amdgpu_ring *ring)
+{
+	struct amdgpu_device *adev = ring->adev;
+
+	amdgpu_gfx_off_ctrl(adev, false);
+}
+
+void amdgpu_sdma_ring_end_use(struct amdgpu_ring *ring)
+{
+	struct amdgpu_device *adev = ring->adev;
+
+	amdgpu_gfx_off_ctrl(adev, true);
+}
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h
index 173a2a308078..b52d16829204 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h
@@ -171,4 +171,7 @@ void amdgpu_sdma_destroy_inst_ctx(struct amdgpu_device *adev,
         bool duplicate);
 int amdgpu_sdma_ras_sw_init(struct amdgpu_device *adev);
 
+void amdgpu_sdma_ring_begin_use(struct amdgpu_ring *ring);
+void amdgpu_sdma_ring_end_use(struct amdgpu_ring *ring);
+
 #endif
-- 
2.42.0