[PATCH 1/6] drm/amdgpu/bu: Use legacy TLB flush for gfx943

[Alex Deucher]

From: Graham Sider <Graham.Sider at amd.com>

Invalidate TLBs via a legacy flush request (flush_type=0) prior to the
heavyweight flush requests (flush_type=2) in gmc_v9_0.c. This is
temporarily required to mitigate a bug causing CPC UTCL1 to return stale
translations after invalidation requests in address range mode.

Signed-off-by: Graham Sider <Graham.Sider at amd.com>
Reviewed-by: Philip Yang <Philip.Yang at amd.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
index f000e0e89bd0..d28ffdb07ae6 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
@@ -833,6 +833,14 @@ static void gmc_v9_0_flush_gpu_tlb(struct amdgpu_device *adev, uint32_t vmid,
 		 */
 		inv_req = gmc_v9_0_get_invalidate_req(vmid, 2);
 		inv_req2 = gmc_v9_0_get_invalidate_req(vmid, flush_type);
+	} else if (flush_type == 2 &&
+		   adev->ip_versions[GC_HWIP][0] == IP_VERSION(9, 4, 3)) {
+		/* FIXME: Temporarily add a legacy flush (type 0) before heavyweight
+		 * flush for gfx943 to mitigate a bug which causes CPC UTCL1 to return
+		 * stale translations even after TLB heavyweight flush.
+		 */
+		inv_req = gmc_v9_0_get_invalidate_req(vmid, 0);
+		inv_req2 = gmc_v9_0_get_invalidate_req(vmid, flush_type);
 	} else {
 		inv_req = gmc_v9_0_get_invalidate_req(vmid, flush_type);
 		inv_req2 = 0;
@@ -976,6 +984,15 @@ static int gmc_v9_0_flush_gpu_tlb_pasid(struct amdgpu_device *adev,
 		if (vega20_xgmi_wa)
 			kiq->pmf->kiq_invalidate_tlbs(ring,
 						      pasid, 2, all_hub);
+
+		/* FIXME: Temporarily add a legacy flush (type 0) before heavyweight
+		 * flush for gfx943 to mitigate a bug which causes CPC UTCL1 to return
+		 * stale translations even after TLB heavyweight flush.
+		 */
+		if (flush_type == 2 && adev->ip_versions[GC_HWIP][0] == IP_VERSION(9, 4, 3))
+			kiq->pmf->kiq_invalidate_tlbs(ring,
+						pasid, 0, all_hub);
+
 		kiq->pmf->kiq_invalidate_tlbs(ring,
 					pasid, flush_type, all_hub);
 		r = amdgpu_fence_emit_polling(ring, &seq, MAX_KIQ_REG_WAIT);
-- 
2.40.1