drm/amdgpu: Enable SDMA context switching for CIK

Enable SDMA context switching on CIK (copied from sdma_v3_0.c).

Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Chunming Zhou <david1.zhou@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/cik_sdma.c b/drivers/gpu/drm/amd/amdgpu/cik_sdma.c
index c216e16..4a9cea0 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/cik_sdma.c
+++ b/drivers/gpu/drm/amd/amdgpu/cik_sdma.c
@@ -342,6 +342,33 @@ static void cik_sdma_rlc_stop(struct amdgpu_device *adev)
 }
 
 /**
+ * cik_ctx_switch_enable - stop the async dma engines context switch
+ *
+ * @adev: amdgpu_device pointer
+ * @enable: enable/disable the DMA MEs context switch.
+ *
+ * Halt or unhalt the async dma engines context switch (VI).
+ */
+static void cik_ctx_switch_enable(struct amdgpu_device *adev, bool enable)
+{
+       u32 f32_cntl;
+       int i;
+
+       for (i = 0; i < adev->sdma.num_instances; i++) {
+               f32_cntl = RREG32(mmSDMA0_CNTL + sdma_offsets[i]);
+               if (enable) {
+                       f32_cntl = REG_SET_FIELD(f32_cntl, SDMA0_CNTL,
+                                       AUTO_CTXSW_ENABLE, 1);
+               } else {
+                       f32_cntl = REG_SET_FIELD(f32_cntl, SDMA0_CNTL,
+                                       AUTO_CTXSW_ENABLE, 0);
+               }
+
+               WREG32(mmSDMA0_CNTL + sdma_offsets[i], f32_cntl);
+       }
+}
+
+/**
  * cik_sdma_enable - stop the async dma engines
  *
  * @adev: amdgpu_device pointer
@@ -537,6 +564,8 @@ static int cik_sdma_start(struct amdgpu_device *adev)
 
        /* halt the engine before programing */
        cik_sdma_enable(adev, false);
+       /* enable sdma ring preemption */
+       cik_ctx_switch_enable(adev, true);
 
        /* start the gfx rings and rlc compute queues */
        r = cik_sdma_gfx_resume(adev);
@@ -984,6 +1013,7 @@ static int cik_sdma_hw_fini(void *handle)
 {
        struct amdgpu_device *adev = (struct amdgpu_device *)handle;
 
+       cik_ctx_switch_enable(adev, false);
        cik_sdma_enable(adev, false);
 
        return 0;