From: Alex Deucher <alexander.deucher@amd.com>
Date: Tue, 27 Mar 2018 17:10:56 -0500
Subject: drm/amdgpu/gmc9: use amdgpu_ring_emit_reg_write_reg_wait in gpu tlb
 flush
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Git-commit: f8bc903707ae87342b97528037e27bf190051c11
Patch-mainline: v4.18-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

Use amdgpu_ring_emit_reg_write_reg_wait.  On engines that support it,
it provides a write and wait in a single packet which avoids a missed
ack if a world switch happens between the request and waiting for the
ack.

Reviewed-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c |    8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

--- a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
@@ -385,11 +385,9 @@ static uint64_t gmc_v9_0_emit_flush_gpu_
 	amdgpu_ring_emit_wreg(ring, hub->ctx0_ptb_addr_hi32 + (2 * vmid),
 			      upper_32_bits(pd_addr));
 
-	amdgpu_ring_emit_wreg(ring, hub->vm_inv_eng0_req + eng, req);
-
-	/* wait for the invalidate to complete */
-	amdgpu_ring_emit_reg_wait(ring, hub->vm_inv_eng0_ack + eng,
-				  1 << vmid, 1 << vmid);
+	amdgpu_ring_emit_reg_write_reg_wait(ring, hub->vm_inv_eng0_req + eng,
+					    hub->vm_inv_eng0_ack + eng,
+					    req, 1 << vmid);
 
 	return pd_addr;
 }