+
+/*
+ * Check if power limits are available. Two cases when they are not available:
+ * 1. Locked by BIOS, in this case we still provide read-only access so that
+ * users can see what limit is set by the BIOS.
+ * 2. Some CPUs make some domains monitoring only which means PLx MSRs may not
+ * exist at all. In this case, we do not show the contraints in powercap.
+ *
+ * Called after domains are detected and initialized.
+ */
+static void rapl_detect_powerlimit(struct rapl_domain *rd)
+{
+ u64 val64;
+ int i;
+
+ /* check if the domain is locked by BIOS, ignore if MSR doesn't exist */
+ if (!rapl_read_data_raw(rd, FW_LOCK, false, &val64)) {
+ if (val64) {
+ pr_info("RAPL package %d domain %s locked by BIOS\n",
+ rd->rp->id, rd->name);
+ rd->state |= DOMAIN_STATE_BIOS_LOCKED;
+ }
+ }
+ /* check if power limit MSRs exists, otherwise domain is monitoring only */
+ for (i = 0; i < NR_POWER_LIMITS; i++) {
+ int prim = rd->rpl[i].prim_id;
+ if (rapl_read_data_raw(rd, prim, false, &val64))
+ rd->rpl[i].name = NULL;
+ }
+}
+