[PATCH] drm/amdgpu: Enable XGMI mapping for peer device

[Christian König]

Am 22.02.19 um 22:28 schrieb Liu, Shaoyun:
> Adjust vram base offset for XGMI mapping when update the PT entry so
> the address will fall into correct XGMI aperture for peer device
>
> Change-Id: I78bdf244da699d2559481ef5afe9663b3e752236
> Signed-off-by: shaoyunl <shaoyun.liu at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 35 +++++++++++++++++++++++++++++-----
>   1 file changed, 30 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index 942b5eb..e41563b 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -1890,6 +1890,7 @@ static int amdgpu_vm_bo_split_mapping(struct amdgpu_device *adev,
>   				      dma_addr_t *pages_addr,
>   				      struct amdgpu_vm *vm,
>   				      struct amdgpu_bo_va_mapping *mapping,
> +				      uint64_t vram_base_offset,

NAK, please just make sure that the correct adev is used down below.

>   				      uint64_t flags,
>   				      struct drm_mm_node *nodes,
>   				      struct dma_fence **fence)
> @@ -1965,7 +1966,7 @@ static int amdgpu_vm_bo_split_mapping(struct amdgpu_device *adev,
>   			}
>   
>   		} else if (flags & AMDGPU_PTE_VALID) {
> -			addr += adev->vm_manager.vram_base_offset;
> +			addr += vram_base_offset;
>   			addr += pfn << PAGE_SHIFT;
>   		}
>   
> @@ -2012,6 +2013,8 @@ int amdgpu_vm_bo_update(struct amdgpu_device *adev,
>   	struct drm_mm_node *nodes;
>   	struct dma_fence *exclusive, **last_update;
>   	uint64_t flags;
> +	uint64_t vram_base_offset = adev->vm_manager.vram_base_offset;
> +	struct amdgpu_device *bo_adev;
>   	int r;
>   
>   	if (clear || !bo) {
> @@ -2030,9 +2033,31 @@ int amdgpu_vm_bo_update(struct amdgpu_device *adev,
>   		exclusive = reservation_object_get_excl(bo->tbo.resv);
>   	}
>   
> -	if (bo)
> +	if (bo) {
>   		flags = amdgpu_ttm_tt_pte_flags(adev, bo->tbo.ttm, mem);
> -	else
> +		bo_adev = amdgpu_ttm_adev(bo->tbo.bdev);
> +		if (mem && mem->mem_type == TTM_PL_VRAM && adev != bo_adev) {
> +			if (drm_debug & DRM_UT_DRIVER) {
> +				list_for_each_entry(mapping, &bo_va->invalids, list) {
> +					DRM_DEBUG_DRIVER("Try map VRAM va 0x%llx - 0x%llx, offset 0x%llx, from dev %s for peer GPU %s access.\n",
> +						mapping->start << PAGE_SHIFT,
> +						((mapping->last + 1) << PAGE_SHIFT) - 1,
> +						nodes ? nodes->start << PAGE_SHIFT : 0ll,
> +						dev_name(bo_adev->dev),
> +						dev_name(adev->dev));

Big NAK as well. If you want to make that kind of debugging the please 
use trace points for it and not such extensive debug messages.

Regards,
Christian.

> +				}
> +			}
> +			if (adev->gmc.xgmi.hive_id &&
> +			    adev->gmc.xgmi.hive_id == bo_adev->gmc.xgmi.hive_id) {
> +				vram_base_offset = bo_adev->vm_manager.vram_base_offset;
> +				DRM_DEBUG_DRIVER("Used XGMI mapping, vram_base_offset 0x%llx.\n",
> +					vram_base_offset);
> +			} else {
> +				DRM_DEBUG_DRIVER("Failed to map the VRAM for other device access.\n");
> +				return -EINVAL;
> +			}
> +		}
> +	} else
>   		flags = 0x0;
>   
>   	if (clear || (bo && bo->tbo.resv == vm->root.base.bo->tbo.resv))
> @@ -2050,8 +2075,8 @@ int amdgpu_vm_bo_update(struct amdgpu_device *adev,
>   
>   	list_for_each_entry(mapping, &bo_va->invalids, list) {
>   		r = amdgpu_vm_bo_split_mapping(adev, exclusive, pages_addr, vm,
> -					       mapping, flags, nodes,
> -					       last_update);
> +					       mapping, vram_base_offset, flags,
> +					       nodes, last_update);
>   		if (r)
>   			return r;
>   	}