Hi Tyrel,

Tyrel Datwyler <tyr...@linux.ibm.com> writes:
> +static bool valid_cpu_drc_index(struct device_node *parent, u32 drc_index)
> +{
> +     const __be32 *indexes;
> +     int i;
> +
> +     if (of_find_property(parent, "ibm,drc-info", NULL))
> +             return drc_info_valid_index(parent, drc_index);
> +
> +     indexes = of_get_property(parent, "ibm,drc-indexes", NULL);
> +     if (!indexes)
> +             return false;
> +
> +     for (i = 0; i < indexes[0]; i++) {

should this be:

        for (i = 0; i < be32_to_cpu(indexes[0]); i++) {
?


> +             if (be32_to_cpu(indexes[i + 1]) == drc_index)
> +                     return true;
> +     }
> +
> +     return false;
>  }

It looks like this rewrites valid_cpu_drc_index()'s existing code for
parsing ibm,drc-indexes but I don't see the need for this.

This patch would be easier to review if that were dropped or split out.

>  
>  static ssize_t dlpar_cpu_add(u32 drc_index)
> @@ -720,8 +756,11 @@ static int dlpar_cpu_remove_by_count(u32 cpus_to_remove)
>  static int find_dlpar_cpus_to_add(u32 *cpu_drcs, u32 cpus_to_add)
>  {
>       struct device_node *parent;
> +     struct property *info;
> +     const __be32 *indexes;
>       int cpus_found = 0;
> -     int index, rc;
> +     int i, j;
> +     u32 drc_index;
>  
>       parent = of_find_node_by_path("/cpus");
>       if (!parent) {
> @@ -730,24 +769,46 @@ static int find_dlpar_cpus_to_add(u32 *cpu_drcs, u32 
> cpus_to_add)
>               return -1;
>       }
>  
> -     /* Search the ibm,drc-indexes array for possible CPU drcs to
> -      * add. Note that the format of the ibm,drc-indexes array is
> -      * the number of entries in the array followed by the array
> -      * of drc values so we start looking at index = 1.
> -      */
> -     index = 1;
> -     while (cpus_found < cpus_to_add) {
> -             u32 drc;
> +     info = of_find_property(parent, "ibm,drc-info", NULL);
> +     if (info) {
> +             struct of_drc_info drc;
> +             const __be32 *value;
> +             int count;
>  
> -             rc = of_property_read_u32_index(parent, "ibm,drc-indexes",
> -                                             index++, &drc);
> -             if (rc)
> -                     break;
> +             value = of_prop_next_u32(info, NULL, &count);
> +             if (value)
> +                     value++;
>  
> -             if (dlpar_cpu_exists(parent, drc))
> -                     continue;
> +             for (i = 0; i < count; i++) {
> +                     of_read_drc_info_cell(&info, &value, &drc);
> +                     if (strncmp(drc.drc_type, "CPU", 3))
> +                             break;
> +
> +                     for (j = 0; j < drc.num_sequential_elems; j++) {
> +                             drc_index = drc.drc_index_start + 
> (drc.sequential_inc * j);
> +
> +                             if (dlpar_cpu_exists(parent, drc_index))
> +                                     continue;
>  
> -             cpu_drcs[cpus_found++] = drc;
> +                             cpu_drcs[cpus_found++] = drc_index;

I am failing to see how this loop is limited by the cpus_to_add
parameter as it was before this change. It looks like this will overflow
the cpu_drcs array when cpus_to_add is less than the number of cpus
found.

As an aside I don't understand how the add_by_count()/dlpar_cpu_exists()
algorithm could be correct as it currently stands. It seems to pick the
first X indexes for which a corresponding cpu node is absent, but that
set of indexes does not necessarily match the set that is available to
configure. Something to address separately I suppose.

> +                     }
> +             }
> +     } else {
> +             indexes = of_get_property(parent, "ibm,drc-indexes", NULL);
> +
> +             /* Search the ibm,drc-indexes array for possible CPU drcs to
> +             * add. Note that the format of the ibm,drc-indexes array is
> +             * the number of entries in the array followed by the array
> +             * of drc values so we start looking at index = 1.
> +             */
> +             for (i = 1; i < indexes[0]; i++) {
> +                     drc_index = be32_to_cpu(indexes[i]);
> +
> +                     if (dlpar_cpu_exists(parent, drc_index))
> +                             continue;
> +
> +                     cpu_drcs[cpus_found++] = drc_index;
> +             }
>       }

As above, not sure why this was rewritten, and similar comments as
before apply.

Reply via email to