drm/amdgpu: mark A+A VF VRAM mappings as system memory

On the A+A VF the GPU reaches its HBM over the system memory path at a
system physical address, so page table entries covering VRAM have to
carry AMDGPU_PTE_SYSTEM and the addresses they hold have to be physical
rather than MC addresses.

Set the SYSTEM bit in the PDB0 entries and in amdgpu_ttm_tt_pde_flags(),
and convert the VRAM address in amdgpu_gmc_get_pde_for_bo() with
amdgpu_gmc_vram_mc2pa().

NPA mappings still require VSCT=0011 (PTE.S=0). Clear SYSTEM in
gmc_v12_1_get_npa_flags() and amdgpu_ualink_peer_remote_init() so NPA
PTEs do not inherit the VRAM SYSTEM bit.

v2:
- Use (sriov_vf || passthrough) and amdgpu_virt_vram_is_spm() for
  PDB0/TTM SYSTEM bits and mc2pa.

v3:
- Rely on amdgpu_virt_vram_is_spm() without redundant VF/passthrough
  checks.

v4:
- Explicitly clear AMDGPU_PTE_SYSTEM for NPA (VSCT=0011).

Signed-off-by: Zhigang Luo <zhigang.luo@amd.com>
Signed-off-by: Fangsheng Huang <Fangsheng.Huang@amd.com>
Signed-off-by: YuBiao Wang <YuBiao.Wang@amd.com>
Reviewed-by: Philip Yang <philip.yang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

4 files changed, 22 insertions, 3 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c
index 167f1344f8f4..d25ca903e21b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c
@@ -122,6 +122,11 @@ void amdgpu_gmc_get_pde_for_bo(struct amdgpu_bo *bo, int level,
 		break;
 	case TTM_PL_VRAM:
 		*addr = amdgpu_bo_gpu_offset(bo);
+		/* For SPM-backed VRAM, convert the MC address to a physical
+		 * address for system memory path access.
+		 */
+		if (amdgpu_virt_vram_is_spm(adev))
+			*addr = amdgpu_gmc_vram_mc2pa(adev, *addr);
 		break;
 	default:
 		*addr = 0;
@@ -1260,6 +1265,8 @@ void amdgpu_gmc_init_pdb0(struct amdgpu_device *adev)
 	flags |= AMDGPU_PTE_VALID | AMDGPU_PTE_READABLE;
 	flags |= AMDGPU_PTE_WRITEABLE;
 	flags |= AMDGPU_PTE_SNOOPED;
+	if (amdgpu_virt_vram_is_spm(adev))
+		flags |= AMDGPU_PTE_SYSTEM;
 	flags |= AMDGPU_PTE_FRAG((adev->gmc.vmid0_page_table_block_size + 9*1));
 	flags |= AMDGPU_PDE_PTE_FLAG(adev);
 
@@ -1279,6 +1286,8 @@ void amdgpu_gmc_init_pdb0(struct amdgpu_device *adev)
 	 * pointing to a 4K system page
 	 */
 	flags = AMDGPU_PTE_VALID;
+	if (amdgpu_virt_vram_is_spm(adev))
+		flags |= AMDGPU_PTE_SYSTEM;
 	flags |= AMDGPU_PTE_SNOOPED | AMDGPU_PDE_BFS_FLAG(adev, 0);
 	/* Requires gart_ptb_gpu_pa to be 4K aligned */
 	amdgpu_gmc_set_pte_pde(adev, adev->gmc.ptr_pdb0, i, gart_ptb_gpu_pa, flags);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index a3777ceb638f..6b3fbf79abc9 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -1460,9 +1460,17 @@ uint64_t amdgpu_ttm_tt_pde_flags(struct ttm_tt *ttm, struct ttm_resource *mem)
 			flags |= AMDGPU_PTE_SNOOPED;
 	}
 
-	if (mem && mem->mem_type == TTM_PL_VRAM &&
-			mem->bus.caching == ttm_cached)
-		flags |= AMDGPU_PTE_SNOOPED;
+	if (mem && mem->mem_type == TTM_PL_VRAM) {
+		if (mem->bo) {
+			struct amdgpu_device *adev = amdgpu_ttm_adev(mem->bo->bdev);
+
+			if (amdgpu_virt_vram_is_spm(adev))
+				flags |= AMDGPU_PTE_SYSTEM;
+		}
+
+		if (mem->bus.caching == ttm_cached)
+			flags |= AMDGPU_PTE_SNOOPED;
+	}
 
 	return flags;
 }
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ualink.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ualink.c
index 8fed28dc7502..6b1d9f671905 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ualink.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ualink.c
@@ -6141,6 +6141,7 @@ static int amdgpu_ualink_peer_remote_init(struct amdgpu_device *adev)
 	flags = amdgpu_ttm_tt_pte_flags(adev, bo->tbo.ttm, bo->tbo.resource);
 	flags |= AMDGPU_PTE_SNOOPED | AMDGPU_PTE_PRT_GFX12 | AMDGPU_PTE_BUS_ATOMICS;
 	flags &= ~AMDGPU_PTE_VALID;
+	flags &= ~AMDGPU_PTE_SYSTEM;
 	/* PTE.X=0 turn off RPC checks for RBs, wptr and doorbell NPA address */
 	flags &= ~AMDGPU_PTE_EXECUTABLE;
 
diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v12_1.c b/drivers/gpu/drm/amd/amdgpu/gmc_v12_1.c
index 57aac3a9a3b0..df72eb2b67ae 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v12_1.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v12_1.c
@@ -616,6 +616,7 @@ static void gmc_v12_1_get_npa_flags(struct amdgpu_device *adev,
 	*flags |= AMDGPU_PTE_SNOOPED | AMDGPU_PTE_PRT_GFX12 |
 		   AMDGPU_PTE_BUS_ATOMICS;
 	*flags &= ~AMDGPU_PTE_VALID;
+	*flags &= ~AMDGPU_PTE_SYSTEM;
 	*flags &= ~AMDGPU_PTE_EXECUTABLE;
 }