[PATCH 1/2] drm/radeon: use POLL_REG_MEM special op for sDMA HDP flush

[Alex Deucher]

Flush via the ring works differently on CIK and requires a
special sequence.

Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
---
 drivers/gpu/drm/radeon/cik_sdma.c | 36 ++++++++++++++++++++++++------------
 1 file changed, 24 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/radeon/cik_sdma.c b/drivers/gpu/drm/radeon/cik_sdma.c
index 0300727..00984d8 100644
--- a/drivers/gpu/drm/radeon/cik_sdma.c
+++ b/drivers/gpu/drm/radeon/cik_sdma.c
@@ -87,6 +87,28 @@ void cik_sdma_ring_ib_execute(struct radeon_device *rdev,
 
 }
 
+static void cik_sdma_hdp_flush(struct radeon_device *rdev,
+			       int ridx)
+{
+	struct radeon_ring *ring = &rdev->ring[ridx];
+	u32 extra_bits = (SDMA_POLL_REG_MEM_EXTRA_OP(1) |
+			  SDMA_POLL_REG_MEM_EXTRA_FUNC(3)); /* == */
+	u32 ref_and_mask;
+
+	if (ridx == R600_RING_TYPE_DMA_INDEX)
+		ref_and_mask = SDMA0;
+	else
+		ref_and_mask = SDMA1;
+
+	/* flush HDP */
+	radeon_ring_write(ring, SDMA_PACKET(SDMA_OPCODE_POLL_REG_MEM, 0, extra_bits));
+	radeon_ring_write(ring, GPU_HDP_FLUSH_DONE);
+	radeon_ring_write(ring, GPU_HDP_FLUSH_REQ);
+	radeon_ring_write(ring, ref_and_mask); /* REFERENCE */
+	radeon_ring_write(ring, ref_and_mask); /* MASK */
+	radeon_ring_write(ring, (0xfff << 16) | 10); /* RETRY_COUNT, POLL_INTERVAL */
+}
+
 /**
  * cik_sdma_fence_ring_emit - emit a fence on the DMA ring
  *
@@ -111,12 +133,7 @@ void cik_sdma_fence_ring_emit(struct radeon_device *rdev,
 	/* generate an interrupt */
 	radeon_ring_write(ring, SDMA_PACKET(SDMA_OPCODE_TRAP, 0, 0));
 	/* flush HDP */
-	/* We should be using the new POLL_REG_MEM special op packet here
-	 * but it causes sDMA to hang sometimes
-	 */
-	radeon_ring_write(ring, SDMA_PACKET(SDMA_OPCODE_SRBM_WRITE, 0, 0xf000));
-	radeon_ring_write(ring, HDP_MEM_COHERENCY_FLUSH_CNTL >> 2);
-	radeon_ring_write(ring, 0);
+	cik_sdma_hdp_flush(rdev, fence->ring);
 }
 
 /**
@@ -747,12 +764,7 @@ void cik_dma_vm_flush(struct radeon_device *rdev, int ridx, struct radeon_vm *vm
 	radeon_ring_write(ring, VMID(0));
 
 	/* flush HDP */
-	/* We should be using the new POLL_REG_MEM special op packet here
-	 * but it causes sDMA to hang sometimes
-	 */
-	radeon_ring_write(ring, SDMA_PACKET(SDMA_OPCODE_SRBM_WRITE, 0, 0xf000));
-	radeon_ring_write(ring, HDP_MEM_COHERENCY_FLUSH_CNTL >> 2);
-	radeon_ring_write(ring, 0);
+	cik_sdma_hdp_flush(rdev, ridx);
 
 	/* flush TLB */
 	radeon_ring_write(ring, SDMA_PACKET(SDMA_OPCODE_SRBM_WRITE, 0, 0xf000));
-- 
1.8.3.1