Re: [PATCH] powerpc/pseries: Fix numa FORM2 parsing fallback code

["Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>]

Nicholas Piggin <npiggin@gmail.com> writes:

> In case the FORM2 distance table from firmware is not the expected size,
> there is fallback code that just populates the lookup table as local vs
> remote.
>
> However it then continues on to use the distance table. Fix.
>

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>

> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
> Fixes: 1c6b5a7e7405 ("powerpc/pseries: Add support for FORM2 associativity")
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>  arch/powerpc/mm/numa.c | 29 +++++++++++++----------------
>  1 file changed, 13 insertions(+), 16 deletions(-)
>
> diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
> index 6f14c8fb6359..0789cde7f658 100644
> --- a/arch/powerpc/mm/numa.c
> +++ b/arch/powerpc/mm/numa.c
> @@ -380,6 +380,7 @@ static void initialize_form2_numa_distance_lookup_table(void)
>  	const __be32 *numa_lookup_index;
>  	int numa_dist_table_length;
>  	int max_numa_index, distance_index;
> +	bool good = true;
>  
>  	if (firmware_has_feature(FW_FEATURE_OPAL))
>  		root = of_find_node_by_path("/ibm,opal");
> @@ -407,30 +408,26 @@ static void initialize_form2_numa_distance_lookup_table(void)
>  
>  	if (numa_dist_table_length != max_numa_index * max_numa_index) {
>  		WARN(1, "Wrong NUMA distance information\n");
> -		/* consider everybody else just remote. */
> -		for (i = 0;  i < max_numa_index; i++) {
> -			for (j = 0; j < max_numa_index; j++) {
> -				int nodeA = numa_id_index_table[i];
> -				int nodeB = numa_id_index_table[j];
> -
> -				if (nodeA == nodeB)
> -					numa_distance_table[nodeA][nodeB] = LOCAL_DISTANCE;
> -				else
> -					numa_distance_table[nodeA][nodeB] = REMOTE_DISTANCE;
> -			}
> -		}
> +		good = false;
>  	}
> -
>  	distance_index = 0;
>  	for (i = 0;  i < max_numa_index; i++) {
>  		for (j = 0; j < max_numa_index; j++) {
>  			int nodeA = numa_id_index_table[i];
>  			int nodeB = numa_id_index_table[j];
> -
> -			numa_distance_table[nodeA][nodeB] = numa_dist_table[distance_index++];
> -			pr_debug("dist[%d][%d]=%d ", nodeA, nodeB, numa_distance_table[nodeA][nodeB]);
> +			int dist;
> +
> +			if (good)
> +				dist = numa_dist_table[distance_index++];
> +			else if (nodeA == nodeB)
> +				dist = LOCAL_DISTANCE;
> +			else
> +				dist = REMOTE_DISTANCE;
> +			numa_distance_table[nodeA][nodeB] = dist;
> +			pr_debug("dist[%d][%d]=%d ", nodeA, nodeB, dist);
>  		}
>  	}
> +
>  	of_node_put(root);
>  }
>  
> -- 
> 2.23.0