[PATCH] amdkfd: MTYPE_UC for ext-coherent system memory

[Felix Kuehling]

On 2025-06-19 14:40, David Yat Sin wrote:
> Set memory mtype to UC host memory when ext-coherent
> flag is set and memory is registered as a SVM allocation.
>
> Signed-off-by: David Yat Sin <David.YatSin at amd.com>

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


> ---
>   drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
> index 16fb19800f9e..9dba0e4ae4b3 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
> @@ -1282,7 +1282,7 @@ svm_range_get_pte_flags(struct kfd_node *node,
>   				mapping_flags |= ext_coherent ? AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
>   		/* system memory accessed by the dGPU */
>   		} else {
> -			if (gc_ip_version < IP_VERSION(9, 5, 0))
> +			if (gc_ip_version < IP_VERSION(9, 5, 0) || ext_coherent)
>   				mapping_flags |= AMDGPU_VM_MTYPE_UC;
>   			else
>   				mapping_flags |= AMDGPU_VM_MTYPE_NC;