[PATCH v3 2/2] drm/amdgpu: Permit PCIe transfer over links with XGMI

[Felix Kuehling]

On 2023-10-24 15:20, David Francis wrote:
> When the CPU is XGMI connected, the PCIe links should
> not be enumerated for topology purposes. However, PCIe
> transfer should still be a valid option for remote
> doorbells and MMIO mappings.
>
> Move the XGMI connection check out of the shared helper
> function amdgpu_device_is_peer_accessible and into the
> topology path.
>
> Signed-off-by: David Francis <David.Francis at amd.com>

This patch is

Reviewed-by: Felix Kuehling <Felix.Kuehling at amd.com>


> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 4 +---
>   drivers/gpu/drm/amd/amdkfd/kfd_topology.c  | 6 ++++--
>   2 files changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index 7ec32b44df05..a5c054f8a427 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -5783,9 +5783,7 @@ bool amdgpu_device_is_peer_accessible(struct amdgpu_device *adev,
>   		~*peer_adev->dev->dma_mask : ~((1ULL << 32) - 1);
>   	resource_size_t aper_limit =
>   		adev->gmc.aper_base + adev->gmc.aper_size - 1;
> -	bool p2p_access =
> -		!adev->gmc.xgmi.connected_to_cpu &&
> -		!(pci_p2pdma_distance(adev->pdev, peer_adev->dev, false) < 0);
> +	bool p2p_access = !(pci_p2pdma_distance(adev->pdev, peer_adev->dev, false) < 0);
>   
>   	return pcie_p2p && p2p_access && (adev->gmc.visible_vram_size &&
>   		adev->gmc.real_vram_size == adev->gmc.visible_vram_size &&
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
> index 4e530791507e..cb64c19482f3 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
> @@ -1514,11 +1514,13 @@ static int kfd_dev_create_p2p_links(void)
>   			goto next;
>   
>   		/* check if node(s) is/are peer accessible in one direction or bi-direction */
> -		ret = kfd_add_peer_prop(new_dev, dev, i, k);
> +		if (!new_dev->gpu->adev->gmc.xgmi.connected_to_cpu)
> +			ret = kfd_add_peer_prop(new_dev, dev, i, k);
>   		if (ret < 0)
>   			goto out;
>   
> -		ret = kfd_add_peer_prop(dev, new_dev, k, i);
> +		if (!dev->gpu->adev->gmc.xgmi.connected_to_cpu)
> +			ret = kfd_add_peer_prop(dev, new_dev, k, i);
>   		if (ret < 0)
>   			goto out;
>   next: