[PATCH] drm/amdgpu: Restore uncache behaviour on GFX12

[David Belanger]

Always use MTYPE_UC if UNCACHED flag is specified.

This makes kernarg region uncached and it restores
usermode cache disable debug flag functionality.

Do not set MTYPE_UC for COHERENT flag, on GFX12 coherence is handled by
shader code.

Signed-off-by: David Belanger <david.belanger at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/gmc_v12_0.c | 21 ++-------------------
 drivers/gpu/drm/amd/amdkfd/kfd_svm.c   |  8 +-------
 2 files changed, 3 insertions(+), 26 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v12_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v12_0.c
index fd3ac483760e..542225eb13b5 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v12_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v12_0.c
@@ -498,9 +498,6 @@ 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;
-	bool coherent, is_system;
-
 
 	*flags &= ~AMDGPU_PTE_EXECUTABLE;
 	*flags |= mapping->flags & AMDGPU_PTE_EXECUTABLE;
@@ -516,25 +513,11 @@ static void gmc_v12_0_get_vm_pte(struct amdgpu_device *adev,
 		*flags &= ~AMDGPU_PTE_VALID;
 	}
 
-	if (!bo)
-		return;
-
-	if (bo->flags & (AMDGPU_GEM_CREATE_COHERENT |
-			       AMDGPU_GEM_CREATE_UNCACHED))
-		*flags = AMDGPU_PTE_MTYPE_GFX12(*flags, MTYPE_UC);
-
-	bo_adev = amdgpu_ttm_adev(bo->tbo.bdev);
-	coherent = bo->flags & AMDGPU_GEM_CREATE_COHERENT;
-	is_system = (bo->tbo.resource->mem_type == TTM_PL_TT) ||
-		(bo->tbo.resource->mem_type == AMDGPU_PL_PREEMPT);
-
 	if (bo && bo->flags & AMDGPU_GEM_CREATE_GFX12_DCC)
 		*flags |= AMDGPU_PTE_DCC;
 
-	/* WA for HW bug */
-	if (is_system || ((bo_adev != adev) && coherent))
-		*flags = AMDGPU_PTE_MTYPE_GFX12(*flags, MTYPE_NC);
-
+	if (bo && bo->flags & AMDGPU_GEM_CREATE_UNCACHED)
+		*flags = AMDGPU_PTE_MTYPE_GFX12(*flags, MTYPE_UC);
 }
 
 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 bd9c2921e0dc..7b671aefab01 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -1248,13 +1248,7 @@ svm_range_get_pte_flags(struct kfd_node *node,
 		break;
 	case IP_VERSION(12, 0, 0):
 	case IP_VERSION(12, 0, 1):
-		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;
-		}
+		mapping_flags |= AMDGPU_VM_MTYPE_NC;
 		break;
 	default:
 		mapping_flags |= coherent ?
-- 
2.41.0