On Wed, 26 Sep 2018, Reinette Chatre wrote:
> + * Return: 0 if a CDP peer was found, <0 on error or if no CDP peer exists.
> + * If a CDP peer was found, @r_cdp will point to the peer RDT
> resource
> + * and @d_cdp will point to the peer RDT domain.
> + */
> +static int __attribute__((unused)) rdt_cdp_peer_get(struct rdt_resource *r,
> + struct rdt_domain *d,
> + struct rdt_resource **r_cdp,
> + struct rdt_domain **d_cdp)
> +{
> + struct rdt_resource *_r_cdp = NULL;
> + struct rdt_domain *_d_cdp = NULL;
> + int ret = 0;
> +
> + switch (r->rid) {
> + case RDT_RESOURCE_L3DATA:
> + _r_cdp = &rdt_resources_all[RDT_RESOURCE_L3CODE];
> + break;
> + case RDT_RESOURCE_L3CODE:
> + _r_cdp = &rdt_resources_all[RDT_RESOURCE_L3DATA];
> + break;
> + case RDT_RESOURCE_L2DATA:
> + _r_cdp = &rdt_resources_all[RDT_RESOURCE_L2CODE];
> + break;
> + case RDT_RESOURCE_L2CODE:
> + _r_cdp = &rdt_resources_all[RDT_RESOURCE_L2DATA];
> + break;
> + default:
> + ret = -ENOENT;
> + goto out;
> + }
> +
> + /*
> + * When a new CPU comes online and CDP is enabled then the new
> + * RDT domains (if any) associated with both CDP RDT resources
> + * are added in the same CPU online routine while the
> + * rdtgroup_mutex is held. It should thus not happen for one
> + * RDT domain to exist and be associated with its RDT CDP
> + * resource but there is no RDT domain associated with the
> + * peer RDT CDP resource. Hence the WARN.
> + */
> + _d_cdp = rdt_find_domain(_r_cdp, d->id, NULL);
> + if (WARN_ON(!_d_cdp)) {
> + _r_cdp = NULL;
> + ret = -ENOENT;
While this should never happen, the return value is ambiguous. I'd rather
use EINVAL or such and propagate it further down at the call site.
Thanks,
tglx
