Re: [PATCH v4 2/4] EDAC/mce_amd: Extract node id from MCA_IPID

[Yazen Ghannam <yazen.ghannam@amd.com>]

On Fri, Oct 15, 2021 at 12:23:58AM +0530, Naveen Krishna Chatradhi wrote:
> On SMCA banks of the GPU nodes, the node id information is
> available in register MCA_IPID[47:44](InstanceIdHi).
> 
> Convert the hardware node ID to a value used by Linux
> where GPU nodes are sequencially after the CPU nodes.
> 
> Co-developed-by: Muralidhara M K <muralimk@amd.com>
> Signed-off-by: Muralidhara M K <muralimk@amd.com>
> Signed-off-by: Naveen Krishna Chatradhi <nchatrad@amd.com>
> Link: https://lkml.kernel.org/r/20210823185437.94417-3-nchatrad@amd.com
> ---
> Changes since v3:
> 1. Use APIs from amd_nb to identify the gpu_node_start_id and cpu_node_count.
>    Which is required to map the hardware node id to node id enumerated by Linux.
> 
> Changes since v2:
> 1. Modified subject and commit message
> 2. Added Reviewed by Yazen Ghannam
> 
> Changes since v1:
> 1. Modified the commit message
> 2. rearranged the conditions before calling decode_dram_ecc()
> 
>  drivers/edac/mce_amd.c | 24 ++++++++++++++++++++++--
>  1 file changed, 22 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/edac/mce_amd.c b/drivers/edac/mce_amd.c
> index 67dbf4c31271..af6caa76adc7 100644
> --- a/drivers/edac/mce_amd.c
> +++ b/drivers/edac/mce_amd.c
> @@ -2,6 +2,7 @@
>  #include <linux/module.h>
>  #include <linux/slab.h>
>  
> +#include <asm/amd_nb.h>
>  #include <asm/cpu.h>
>  
>  #include "mce_amd.h"
> @@ -1072,8 +1073,27 @@ static void decode_smca_error(struct mce *m)
>  	if (xec < smca_mce_descs[bank_type].num_descs)
>  		pr_cont(", %s.\n", smca_mce_descs[bank_type].descs[xec]);
>  
> -	if (bank_type == SMCA_UMC && xec == 0 && decode_dram_ecc)
> -		decode_dram_ecc(topology_die_id(m->extcpu), m);
> +	if (xec == 0 && decode_dram_ecc) {
> +		int node_id = 0;
> +
> +		if (bank_type == SMCA_UMC) {
> +			node_id = topology_die_id(m->extcpu);
> +		} else if (bank_type == SMCA_UMC_V2) {
> +			/*
> +			 * SMCA_UMC_V2 exists on GPU nodes, extract the node id
> +			 * from register MCA_IPID[47:44](InstanceIdHi).
> +			 * The InstanceIdHi field represents the instance ID of the GPU.
> +			 * Which needs to be mapped to a value used by Linux,
> +			 * where GPU nodes are simply numerically after the CPU nodes.
> +			 */
> +			node_id = ((m->ipid >> 44) & 0xF) -
> +				   amd_gpu_node_start_id() + amd_cpu_node_count();
> +		} else {
> +			return;
> +		}
> +
> +		decode_dram_ecc(node_id, m);
> +	}
>  }
>  
>  static inline void amd_decode_err_code(u16 ec)
> -- 

This looks good to me.

Reviewed-by: Yazen Ghannam <yazen.ghannam@amd.com>

Thanks,
Yazen