[PATCH 1/3] drm/amdgpu: Add userptr bo support for mGPUs when iommu is on

[Shane Xiao]

For userptr bo with iommu on, multiple GPUs use same system
memory dma mapping address when both bo_adev and adev in identity
mode or in the same iommu group.

Signed-off-by: Shane Xiao <shane.xiao at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index e7403f8e4eba..33cda358cb9e 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -804,11 +804,11 @@ static int kfd_mem_attach(struct amdgpu_device *adev, struct kgd_mem *mem,
 			 va + bo_size, vm);
 
 		if ((adev == bo_adev && !(mem->alloc_flags & KFD_IOC_ALLOC_MEM_FLAGS_MMIO_REMAP)) ||
-		    (amdgpu_ttm_tt_get_usermm(mem->bo->tbo.ttm) && adev->ram_is_direct_mapped) ||
-		    same_hive) {
+		    (amdgpu_ttm_tt_get_usermm(mem->bo->tbo.ttm) && ((adev->ram_is_direct_mapped && bo_adev->ram_is_direct_mapped) ||
+			adev->dev->iommu_group == bo_adev->dev->iommu_group)) || same_hive){
 			/* Mappings on the local GPU, or VRAM mappings in the
-			 * local hive, or userptr mapping IOMMU direct map mode
-			 * share the original BO
+			 * local hive, or userptr mapping in the same dma
+			 * address space share the original BO
 			 */
 			attachment[i]->type = KFD_MEM_ATT_SHARED;
 			bo[i] = mem->bo;
-- 
2.25.1