1 files changed, 49 insertions, 35 deletions

diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c
index aedec0957934..59372077ec7c 100644
--- a/drivers/cpuidle/cpuidle-powernv.c
+++ b/drivers/cpuidle/cpuidle-powernv.c
@@ -13,6 +13,7 @@
 #include <linux/notifier.h>
 #include <linux/clockchips.h>
 #include <linux/of.h>
+#include <linux/slab.h>
 
 #include <asm/machdep.h>
 #include <asm/firmware.h>
@@ -158,70 +159,83 @@ static int powernv_add_idle_states(void)
 	struct device_node *power_mgt;
 	int nr_idle_states = 1; /* Snooze */
 	int dt_idle_states;
-	const __be32 *idle_state_flags;
-	const __be32 *idle_state_latency;
-	u32 len_flags, flags, latency_ns;
-	int i;
+	u32 *latency_ns, *residency_ns, *flags;
+	int i, rc;
 
 	/* Currently we have snooze statically defined */
 
 	power_mgt = of_find_node_by_path("/ibm,opal/power-mgt");
 	if (!power_mgt) {
 		pr_warn("opal: PowerMgmt Node not found\n");
-		return nr_idle_states;
+		goto out;
 	}
 
-	idle_state_flags = of_get_property(power_mgt, "ibm,cpu-idle-state-flags", &len_flags);
-	if (!idle_state_flags) {
-		pr_warn("DT-PowerMgmt: missing ibm,cpu-idle-state-flags\n");
-		return nr_idle_states;
+	/* Read values of any property to determine the num of idle states */
+	dt_idle_states = of_property_count_u32_elems(power_mgt, "ibm,cpu-idle-state-flags");
+	if (dt_idle_states < 0) {
+		pr_warn("cpuidle-powernv: no idle states found in the DT\n");
+		goto out;
 	}
 
-	idle_state_latency = of_get_property(power_mgt,
-			"ibm,cpu-idle-state-latencies-ns", NULL);
-	if (!idle_state_latency) {
-		pr_warn("DT-PowerMgmt: missing ibm,cpu-idle-state-latencies-ns\n");
-		return nr_idle_states;
+	flags = kzalloc(sizeof(*flags) * dt_idle_states, GFP_KERNEL);
+	if (of_property_read_u32_array(power_mgt,
+			"ibm,cpu-idle-state-flags", flags, dt_idle_states)) {
+		pr_warn("cpuidle-powernv : missing ibm,cpu-idle-state-flags in DT\n");
+		goto out_free_flags;
 	}
 
-	dt_idle_states = len_flags / sizeof(u32);
+	latency_ns = kzalloc(sizeof(*latency_ns) * dt_idle_states, GFP_KERNEL);
+	rc = of_property_read_u32_array(power_mgt,
+		"ibm,cpu-idle-state-latencies-ns", latency_ns, dt_idle_states);
+	if (rc) {
+		pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-latencies-ns in DT\n");
+		goto out_free_latency;
+	}
 
-	for (i = 0; i < dt_idle_states; i++) {
+	residency_ns = kzalloc(sizeof(*residency_ns) * dt_idle_states, GFP_KERNEL);
+	rc = of_property_read_u32_array(power_mgt,
+		"ibm,cpu-idle-state-residency-ns", residency_ns, dt_idle_states);
 
-		flags = be32_to_cpu(idle_state_flags[i]);
+	for (i = 0; i < dt_idle_states; i++) {
 
-		/* Cpuidle accepts exit_latency in us and we estimate
-		 * target residency to be 10x exit_latency
+		/*
+		 * Cpuidle accepts exit_latency and target_residency in us.
+		 * Use default target_residency values if f/w does not expose it.
 		 */
-		latency_ns = be32_to_cpu(idle_state_latency[i]);
-		if (flags & OPAL_PM_NAP_ENABLED) {
+		if (flags[i] & OPAL_PM_NAP_ENABLED) {
 			/* Add NAP state */
 			strcpy(powernv_states[nr_idle_states].name, "Nap");
 			strcpy(powernv_states[nr_idle_states].desc, "Nap");
 			powernv_states[nr_idle_states].flags = 0;
-			powernv_states[nr_idle_states].exit_latency =
-					((unsigned int)latency_ns) / 1000;
-			powernv_states[nr_idle_states].target_residency =
-					((unsigned int)latency_ns / 100);
+			powernv_states[nr_idle_states].target_residency = 100;
 			powernv_states[nr_idle_states].enter = &nap_loop;
-			nr_idle_states++;
-		}
-
-		if (flags & OPAL_PM_SLEEP_ENABLED ||
-			flags & OPAL_PM_SLEEP_ENABLED_ER1) {
+		} else if (flags[i] & OPAL_PM_SLEEP_ENABLED ||
+			flags[i] & OPAL_PM_SLEEP_ENABLED_ER1) {
 			/* Add FASTSLEEP state */
 			strcpy(powernv_states[nr_idle_states].name, "FastSleep");
 			strcpy(powernv_states[nr_idle_states].desc, "FastSleep");
 			powernv_states[nr_idle_states].flags = CPUIDLE_FLAG_TIMER_STOP;
-			powernv_states[nr_idle_states].exit_latency =
-					((unsigned int)latency_ns) / 1000;
-			powernv_states[nr_idle_states].target_residency =
-					((unsigned int)latency_ns / 100);
+			powernv_states[nr_idle_states].target_residency = 300000;
 			powernv_states[nr_idle_states].enter = &fastsleep_loop;
-			nr_idle_states++;
 		}
+
+		powernv_states[nr_idle_states].exit_latency =
+				((unsigned int)latency_ns[i]) / 1000;
+
+		if (!rc) {
+			powernv_states[nr_idle_states].target_residency =
+				((unsigned int)residency_ns[i]) / 1000;
+		}
+
+		nr_idle_states++;
 	}
 
+	kfree(residency_ns);
+out_free_latency:
+	kfree(latency_ns);
+out_free_flags:
+	kfree(flags);
+out:
 	return nr_idle_states;
 }