On 2021-12-07 9:59 a.m., Philip Yang wrote:
For userptr bo, if adev is not in IOMMU isolation mode, multiple GPUs
use same system memory page dma mapping address, they can share the
original mem->bo in attachment to reduce dma address array memory usage.
Signed-off-by: Philip Yang <Philip.Yang@xxxxxxx>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 12 ++++++++----
1 file changed, 8 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 b8490789eef4..03807ed1f6e2 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -708,10 +708,14 @@ static int kfd_mem_attach(struct amdgpu_device *adev, struct kgd_mem *mem,
pr_debug("\t add VA 0x%llx - 0x%llx to vm %p\n", va,
va + bo_size, vm);
- if (adev == bo_adev || (mem->domain == AMDGPU_GEM_DOMAIN_VRAM &&
- amdgpu_xgmi_same_hive(adev, bo_adev))) {
- /* Mappings on the local GPU and VRAM mappings in the
- * local hive share the original BO
+ if (adev == bo_adev ||
+ (amdgpu_ttm_tt_get_usermm(mem->bo->tbo.ttm) &&
+ !adev->iommu_isolation) ||
+ (mem->domain == AMDGPU_GEM_DOMAIN_VRAM &&
+ amdgpu_xgmi_same_hive(adev, bo_adev))) {
For the sake of readability I'd ignore the 80-column rule here (which
isn't a hard rule any more). It could apply in the same way to GTT. This
would be clearer:
+ if (adev == bo_adev ||
+ (amdgpu_ttm_tt_get_usermm(mem->bo->tbo.ttm) && adev->ram_is_direct_mapped) ||
+ (mem->domain == AMDGPU_GEM_DOMAIN_VRAM && amdgpu_xgmi_same_hive(adev, bo_adev))) {
Regards,
Felix
+ /* Mappings on the local GPU, or VRAM mappings in the
+ * local hive, or userptr mapping IOMMU is not isolation
+ * mode share the original BO
*/
attachment[i]->type = KFD_MEM_ATT_SHARED;
bo[i] = mem->bo;
