[PATCH 14/14] drm/amdkfd: mark GFX12 system and peer GPU memory mappings as MTYPE_NC

[Alex Deucher]

From: Sreekant Somasekharan <sreekant.somasekharan at amd.com>

Due to a HW bug, the system memory mappings and peer GPU mappings
on GFX12 need to be marked as MTYPE_NC.

Cc: Joe Greathouse <joseph.greathouse at amd.com>
Cc: David Belanger <david.belanger at amd.com>
Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj at amd.com>
Signed-off-by: Sreekant Somasekharan <sreekant.somasekharan at amd.com>
Reviewed-by: Harish Kasiviswanathan <Harish.Kasiviswanathan at amd.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/gmc_v12_0.c | 9 +++++++++
 drivers/gpu/drm/amd/amdkfd/kfd_svm.c   | 9 +++++++++
 2 files changed, 18 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v12_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v12_0.c
index c24f5bd3e09ce..3e6676fdc1875 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v12_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v12_0.c
@@ -497,6 +497,10 @@ static void gmc_v12_0_get_vm_pte(struct amdgpu_device *adev,
 				 uint64_t *flags)
 {
 	struct amdgpu_bo *bo = mapping->bo_va->base.bo;
+	struct amdgpu_device *bo_adev = amdgpu_ttm_adev(bo->tbo.bdev);
+	bool coherent = bo->flags & AMDGPU_GEM_CREATE_COHERENT;
+	bool is_system = bo->tbo.resource->mem_type == TTM_PL_SYSTEM;
+
 
 	*flags &= ~AMDGPU_PTE_EXECUTABLE;
 	*flags |= mapping->flags & AMDGPU_PTE_EXECUTABLE;
@@ -515,6 +519,11 @@ static void gmc_v12_0_get_vm_pte(struct amdgpu_device *adev,
 			       AMDGPU_GEM_CREATE_UNCACHED))
 		*flags = (*flags & ~AMDGPU_PTE_MTYPE_GFX12_MASK) |
 			 AMDGPU_PTE_MTYPE_GFX12(MTYPE_UC);
+
+	/* WA for HW bug */
+	if ((bo && is_system) || ((bo_adev != adev) && coherent))
+		*flags |= AMDGPU_PTE_MTYPE_GFX12(MTYPE_NC);
+
 }
 
 static unsigned gmc_v12_0_get_vbios_fb_size(struct amdgpu_device *adev)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index fc5ede17f7c22..db90795e6245a 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -1248,6 +1248,15 @@ svm_range_get_pte_flags(struct kfd_node *node,
 			mapping_flags |= AMDGPU_VM_MTYPE_UC;
 		}
 		break;
+	case IP_VERSION(12, 0, 0):
+		if (domain == SVM_RANGE_VRAM_DOMAIN) {
+			if (bo_node != node)
+				mapping_flags |= AMDGPU_VM_MTYPE_NC;
+		} else {
+			mapping_flags |= coherent ?
+				AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
+		}
+		break;
 	default:
 		mapping_flags |= coherent ?
 			AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
-- 
2.44.0