From: Hawking Zhang <Hawking.Zhang@amd.com>
Date: Sat, 17 Jan 2026 08:01:20 +0000 (+0800)
Subject: drm/amdgpu: Limit physical transcation mode to A + A only
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cc692ae3e10ea9c84e280a01a325609af69455cf;p=thirdparty%2Flinux.git

drm/amdgpu: Limit physical transcation mode to A + A only

Only enable page table walker to snoop CPU cache
on A + A platform

Signed-off-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: Le Ma <le.ma@amd.com>
Reviewed-by: Feifei Xu <Feifei.Xu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---

diff --git a/drivers/gpu/drm/amd/amdgpu/gfxhub_v12_1.c b/drivers/gpu/drm/amd/amdgpu/gfxhub_v12_1.c
index 4aa004ee2c4d9..6a6f1707cb53e 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfxhub_v12_1.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfxhub_v12_1.c
@@ -325,10 +325,18 @@ static void gfxhub_v12_1_xcc_init_cache_regs(struct amdgpu_device *adev,
 		WREG32_SOC15_RLC(GC, GET_INST(GC, i), regGCVM_L2_CNTL3, tmp);
 
 		tmp = regGCVM_L2_CNTL4_DEFAULT;
-		tmp = REG_SET_FIELD(tmp, GCVM_L2_CNTL4,
-				    VMC_TAP_PDE_REQUEST_PHYSICAL, 1);
-		tmp = REG_SET_FIELD(tmp, GCVM_L2_CNTL4,
-				    VMC_TAP_PTE_REQUEST_PHYSICAL, 1);
+		if (adev->gmc.xgmi.connected_to_cpu) {
+			tmp = REG_SET_FIELD(tmp, GCVM_L2_CNTL4,
+					    VMC_TAP_PDE_REQUEST_PHYSICAL, 1);
+			tmp = REG_SET_FIELD(tmp, GCVM_L2_CNTL4,
+					    VMC_TAP_PTE_REQUEST_PHYSICAL, 1);
+		} else {
+			tmp = REG_SET_FIELD(tmp, GCVM_L2_CNTL4,
+					    VMC_TAP_PDE_REQUEST_PHYSICAL, 0);
+			tmp = REG_SET_FIELD(tmp, GCVM_L2_CNTL4,
+					    VMC_TAP_PTE_REQUEST_PHYSICAL, 0);
+		}
+
 		WREG32_SOC15_RLC(GC, GET_INST(GC, i), regGCVM_L2_CNTL4, tmp);
 
 		tmp = regGCVM_L2_CNTL5_DEFAULT;