[PATCH 2/2] drm/amdkfd: Adjust weight to represent num_hops info when report xgmi iolink

[Kuehling, Felix]

On 2019-04-17 2:59 p.m., Liu, Shaoyun wrote:
> Upper level runtime need the xgmi hops info to determine the data path
>
> Change-Id: I969b419eab125157e223e9b03980ca229c1e6af4
> Signed-off-by: shaoyunl <shaoyun.liu at amd.com>
> ---
>   drivers/gpu/drm/amd/amdkfd/kfd_crat.c | 8 ++++++--
>   drivers/gpu/drm/amd/amdkfd/kfd_crat.h | 3 ++-
>   2 files changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_crat.c b/drivers/gpu/drm/amd/amdkfd/kfd_crat.c
> index 2e7c449..d48c6c5 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_crat.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_crat.c
> @@ -341,6 +341,7 @@ static int kfd_parse_subtype_cache(struct crat_subtype_cache *cache,
>   	return 0;
>   }
>   
> +
>   /* kfd_parse_subtype_iolink - parse iolink subtypes and attach it to correct
>    * topology device present in the device_list
>    */
> @@ -372,7 +373,7 @@ static int kfd_parse_subtype_iolink(struct crat_subtype_iolink *iolink,
>   			if (props->iolink_type == CRAT_IOLINK_TYPE_PCIEXPRESS)
>   				props->weight = 20;
>   			else if (props->iolink_type == CRAT_IOLINK_TYPE_XGMI)
> -				props->weight = 15;
> +				props->weight = 15 * iolink->num_hops_xgmi;
>   			else
>   				props->weight = node_distance(id_from, id_to);
>   
> @@ -1092,6 +1093,7 @@ static int kfd_fill_gpu_direct_io_link_to_cpu(int *avail_size,
>   
>   static int kfd_fill_gpu_xgmi_link_to_gpu(int *avail_size,
>   			struct kfd_dev *kdev,
> +			struct kfd_dev *peer_kdev,
>   			struct crat_subtype_iolink *sub_type_hdr,
>   			uint32_t proximity_domain_from,
>   			uint32_t proximity_domain_to)
> @@ -1110,6 +1112,8 @@ static int kfd_fill_gpu_xgmi_link_to_gpu(int *avail_size,
>   	sub_type_hdr->io_interface_type = CRAT_IOLINK_TYPE_XGMI;
>   	sub_type_hdr->proximity_domain_from = proximity_domain_from;
>   	sub_type_hdr->proximity_domain_to = proximity_domain_to;
> +	sub_type_hdr->num_hops_xgmi =
> +		amdgpu_amdkfd_get_xgmi_hops_count(kdev->kgd, peer_kdev->kgd);
>   	return 0;
>   }
>   
> @@ -1287,7 +1291,7 @@ static int kfd_create_vcrat_image_gpu(void *pcrat_image,
>   				(char *)sub_type_hdr +
>   				sizeof(struct crat_subtype_iolink));
>   			ret = kfd_fill_gpu_xgmi_link_to_gpu(
> -				&avail_size, kdev,
> +				&avail_size, kdev, peer_dev->gpu,
>   				(struct crat_subtype_iolink *)sub_type_hdr,
>   				proximity_domain, nid);
>   			if (ret < 0)
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_crat.h b/drivers/gpu/drm/amd/amdkfd/kfd_crat.h
> index 7c3f192..579835c 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_crat.h
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_crat.h
> @@ -257,7 +257,7 @@ struct crat_subtype_ccompute {
>   #define CRAT_IOLINK_TYPE_OTHER		16
>   #define CRAT_IOLINK_TYPE_MAX		255
>   
> -#define CRAT_IOLINK_RESERVED_LENGTH	24
> +#define CRAT_IOLINK_RESERVED_LENGTH	20
>   
>   struct crat_subtype_iolink {
>   	uint8_t		type;
> @@ -274,6 +274,7 @@ struct crat_subtype_iolink {
>   	uint32_t	minimum_bandwidth_mbs;
>   	uint32_t	maximum_bandwidth_mbs;
>   	uint32_t	recommended_transfer_size;
> +	uint32_t	num_hops_xgmi;
>   	uint8_t		reserved2[CRAT_IOLINK_RESERVED_LENGTH];

It would be safer to add num_hops_xgmi at the end of the reserved space. 
uint8_t is probably enough for the hop count. I'd also not change the 
CRAT_IOLINK_RESERVED_LENGTH. Instead this would work and make it clearer 
that we're appropriating some reserved space:

     ...
     uint8_t    reserved2[CRAT_IOLINK_RESERVED_LENGTH - 1];
     uint8_t    num_hops_xgmi;
};


>   };
>