powercap/intel_rapl: enumerate Psys RAPL domain together with package RAPL domain

On multi-package systems, the Psys MSR is only valid for CPUs on
specific package (master package). The current code makes the
assumption that package 0 is the master package, but this is not
true on new platforms like SPR.

Fix the problem by emuerating the Psys RAPL domain for every
package, so CPUs in slave packages will read 0 for the Psys energy
counter and only CPUs in master packages can get a valid reading
and register the Psys RAPL domain.

The sysfs I/F for the Psys RAPL domain is not changed.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/powercap/intel_rapl_common.c

@@ -544,7 +544,14 @@ static void rapl_init_domains(struct rapl_package *rp)
 			continue;
 
 		rd->rp = rp;
-		rd->name = rapl_domain_names[i];
+
+		if (i == RAPL_DOMAIN_PLATFORM && rp->id > 0) {
+			snprintf(rd->name, RAPL_DOMAIN_NAME_LENGTH, "psys-%d",
+				cpu_data(rp->lead_cpu).phys_proc_id);
+		} else
+			snprintf(rd->name, RAPL_DOMAIN_NAME_LENGTH, "%s",
+				rapl_domain_names[i]);
+
 		rd->id = i;
 		rd->rpl[0].prim_id = PL1_ENABLE;
 		rd->rpl[0].name = pl1_name;
@@ -1112,13 +1119,17 @@ static int rapl_package_register_powercap(struct rapl_package *rp)
 	}
 	/* now register domains as children of the socket/package */
 	for (rd = rp->domains; rd < rp->domains + rp->nr_domains; rd++) {
+		struct powercap_zone *parent = rp->power_zone;
+
 		if (rd->id == RAPL_DOMAIN_PACKAGE)
 			continue;
+		if (rd->id == RAPL_DOMAIN_PLATFORM)
+			parent = NULL;
 		/* number of power limits per domain varies */
 		nr_pl = find_nr_power_limit(rd);
 		power_zone = powercap_register_zone(&rd->power_zone,
 						    rp->priv->control_type,
-						    rd->name, rp->power_zone,
+						    rd->name, parent,
 						    &zone_ops[rd->id], nr_pl,
 						    &constraint_ops);
 
@@ -1145,67 +1156,6 @@ static int rapl_package_register_powercap(struct rapl_package *rp)
 	return ret;
 }
 
-int rapl_add_platform_domain(struct rapl_if_priv *priv)
-{
-	struct rapl_domain *rd;
-	struct powercap_zone *power_zone;
-	struct reg_action ra;
-	int ret;
-
-	ra.reg = priv->regs[RAPL_DOMAIN_PLATFORM][RAPL_DOMAIN_REG_STATUS];
-	ra.mask = ~0;
-	ret = priv->read_raw(0, &ra);
-	if (ret || !ra.value)
-		return -ENODEV;
-
-	ra.reg = priv->regs[RAPL_DOMAIN_PLATFORM][RAPL_DOMAIN_REG_LIMIT];
-	ra.mask = ~0;
-	ret = priv->read_raw(0, &ra);
-	if (ret || !ra.value)
-		return -ENODEV;
-
-	rd = kzalloc(sizeof(*rd), GFP_KERNEL);
-	if (!rd)
-		return -ENOMEM;
-
-	rd->name = rapl_domain_names[RAPL_DOMAIN_PLATFORM];
-	rd->id = RAPL_DOMAIN_PLATFORM;
-	rd->regs[RAPL_DOMAIN_REG_LIMIT] =
-	    priv->regs[RAPL_DOMAIN_PLATFORM][RAPL_DOMAIN_REG_LIMIT];
-	rd->regs[RAPL_DOMAIN_REG_STATUS] =
-	    priv->regs[RAPL_DOMAIN_PLATFORM][RAPL_DOMAIN_REG_STATUS];
-	rd->rpl[0].prim_id = PL1_ENABLE;
-	rd->rpl[0].name = pl1_name;
-	rd->rpl[1].prim_id = PL2_ENABLE;
-	rd->rpl[1].name = pl2_name;
-	rd->rp = rapl_find_package_domain(0, priv);
-
-	power_zone = powercap_register_zone(&rd->power_zone, priv->control_type,
-					    "psys", NULL,
-					    &zone_ops[RAPL_DOMAIN_PLATFORM],
-					    2, &constraint_ops);
-
-	if (IS_ERR(power_zone)) {
-		kfree(rd);
-		return PTR_ERR(power_zone);
-	}
-
-	priv->platform_rapl_domain = rd;
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(rapl_add_platform_domain);
-
-void rapl_remove_platform_domain(struct rapl_if_priv *priv)
-{
-	if (priv->platform_rapl_domain) {
-		powercap_unregister_zone(priv->control_type,
-				 &priv->platform_rapl_domain->power_zone);
-		kfree(priv->platform_rapl_domain);
-	}
-}
-EXPORT_SYMBOL_GPL(rapl_remove_platform_domain);
-
 static int rapl_check_domain(int cpu, int domain, struct rapl_package *rp)
 {
 	struct reg_action ra;
@@ -1215,11 +1165,9 @@ static int rapl_check_domain(int cpu, int domain, struct rapl_package *rp)
 	case RAPL_DOMAIN_PP0:
 	case RAPL_DOMAIN_PP1:
 	case RAPL_DOMAIN_DRAM:
+	case RAPL_DOMAIN_PLATFORM:
 		ra.reg = rp->priv->regs[domain][RAPL_DOMAIN_REG_STATUS];
 		break;
-	case RAPL_DOMAIN_PLATFORM:
-		/* PSYS(PLATFORM) is not a CPU domain, so avoid printng error */
-		return -EINVAL;
 	default:
 		pr_err("invalid domain id %d\n", domain);
 		return -EINVAL;

drivers/powercap/intel_rapl_msr.c

@@ -44,6 +44,7 @@ static struct rapl_if_priv rapl_msr_priv = {
 	.regs[RAPL_DOMAIN_PLATFORM] = {
 		MSR_PLATFORM_POWER_LIMIT, MSR_PLATFORM_ENERGY_STATUS, 0, 0, 0},
 	.limits[RAPL_DOMAIN_PACKAGE] = 2,
+	.limits[RAPL_DOMAIN_PLATFORM] = 2,
 };
 
 /* Handles CPU hotplug on multi-socket systems.
@@ -157,9 +158,6 @@ static int rapl_msr_probe(struct platform_device *pdev)
 		goto out;
 	rapl_msr_priv.pcap_rapl_online = ret;
 
-	/* Don't bail out if PSys is not supported */
-	rapl_add_platform_domain(&rapl_msr_priv);
-
 	return 0;
 
 out:
@@ -171,7 +169,6 @@ static int rapl_msr_probe(struct platform_device *pdev)
 static int rapl_msr_remove(struct platform_device *pdev)
 {
 	cpuhp_remove_state(rapl_msr_priv.pcap_rapl_online);
-	rapl_remove_platform_domain(&rapl_msr_priv);
 	powercap_unregister_control_type(rapl_msr_priv.control_type);
 	return 0;
 }

include/linux/intel_rapl.h

@@ -79,8 +79,10 @@ struct rapl_power_limit {
 
 struct rapl_package;
 
+#define RAPL_DOMAIN_NAME_LENGTH 16
+
 struct rapl_domain {
-	const char *name;
+	char name[RAPL_DOMAIN_NAME_LENGTH];
 	enum rapl_domain_type id;
 	u64 regs[RAPL_DOMAIN_REG_MAX];
 	struct powercap_zone power_zone;
@@ -152,7 +154,4 @@ struct rapl_package *rapl_find_package_domain(int cpu, struct rapl_if_priv *priv
 struct rapl_package *rapl_add_package(int cpu, struct rapl_if_priv *priv);
 void rapl_remove_package(struct rapl_package *rp);
 
-int rapl_add_platform_domain(struct rapl_if_priv *priv);
-void rapl_remove_platform_domain(struct rapl_if_priv *priv);
-
 #endif /* __INTEL_RAPL_H__ */