1 files changed, 65 insertions, 17 deletions

diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c
index 4fb97cef82fd..fdae1c476e27 100644
--- a/drivers/cpuidle/cpuidle-powernv.c
+++ b/drivers/cpuidle/cpuidle-powernv.c
@@ -12,10 +12,17 @@
 #include <linux/cpu.h>
 #include <linux/notifier.h>
 #include <linux/clockchips.h>
+#include <linux/of.h>
 
 #include <asm/machdep.h>
 #include <asm/firmware.h>
 
+/* Flags and constants used in PowerNV platform */
+
+#define MAX_POWERNV_IDLE_STATES 8
+#define IDLE_USE_INST_NAP       0x00010000 /* Use nap instruction */
+#define IDLE_USE_INST_SLEEP     0x00020000 /* Use sleep instruction */
+
 struct cpuidle_driver powernv_idle_driver = {
         .name             = "powernv_idle",
         .owner            = THIS_MODULE,
@@ -79,7 +86,7 @@ static int fastsleep_loop(struct cpuidle_device *dev,
 /*
  * States for dedicated partition case.
  */
-static struct cpuidle_state powernv_states[] = {
+static struct cpuidle_state powernv_states[MAX_POWERNV_IDLE_STATES] = {
         { /* Snooze */
                 .name = "snooze",
                 .desc = "snooze",
@@ -87,20 +94,6 @@ static struct cpuidle_state powernv_states[] = {
                 .exit_latency = 0,
                 .target_residency = 0,
                 .enter = &snooze_loop },
-        { /* NAP */
-                .name = "NAP",
-                .desc = "NAP",
-                .flags = CPUIDLE_FLAG_TIME_VALID,
-                .exit_latency = 10,
-                .target_residency = 100,
-                .enter = &nap_loop },
-         { /* Fastsleep */
-                .name = "fastsleep",
-                .desc = "fastsleep",
-                .flags = CPUIDLE_FLAG_TIME_VALID,
-                .exit_latency = 10,
-                .target_residency = 100,
-                .enter = &fastsleep_loop },
 };
 
 static int powernv_cpuidle_add_cpu_notifier(struct notifier_block *n,
@@ -161,19 +154,74 @@ static int powernv_cpuidle_driver_init(void)
         return 0;
 }
 
+static int powernv_add_idle_states(void)
+{
+        struct device_node *power_mgt;
+        struct property *prop;
+        int nr_idle_states = 1; /* Snooze */
+        int dt_idle_states;
+        u32 *flags;
+        int i;
+
+        /* 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;
+        }
+
+        prop = of_find_property(power_mgt, "ibm,cpu-idle-state-flags", NULL);
+        if (!prop) {
+                pr_warn("DT-PowerMgmt: missing ibm,cpu-idle-state-flags\n");
+                return nr_idle_states;
+        }
+
+        dt_idle_states = prop->length / sizeof(u32);
+        flags = (u32 *) prop->value;
+
+        for (i = 0; i < dt_idle_states; i++) {
+
+                if (flags[i] & IDLE_USE_INST_NAP) {
+                        /* 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 = CPUIDLE_FLAG_TIME_VALID;
+                        powernv_states[nr_idle_states].exit_latency = 10;
+                        powernv_states[nr_idle_states].target_residency = 100;
+                        powernv_states[nr_idle_states].enter = &nap_loop;
+                        nr_idle_states++;
+                }
+
+                if (flags[i] & IDLE_USE_INST_SLEEP) {
+                        /* 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_TIME_VALID | CPUIDLE_FLAG_TIMER_STOP;
+                        powernv_states[nr_idle_states].exit_latency = 300;
+                        powernv_states[nr_idle_states].target_residency = 1000000;
+                        powernv_states[nr_idle_states].enter = &fastsleep_loop;
+                        nr_idle_states++;
+                }
+        }
+
+        return nr_idle_states;
+}
+
 /*
  * powernv_idle_probe()
  * Choose state table for shared versus dedicated partition
  */
 static int powernv_idle_probe(void)
 {
-
         if (cpuidle_disable != IDLE_NO_OVERRIDE)
                 return -ENODEV;
 
         if (firmware_has_feature(FW_FEATURE_OPALv3)) {
                 cpuidle_state_table = powernv_states;
-                max_idle_state = ARRAY_SIZE(powernv_states);
+                /* Device tree can indicate more idle states */
+                max_idle_state = powernv_add_idle_states();
         } else
                 return -ENODEV;