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;
 }