cpuidle:powernv: Add helper function to populate powernv idle states.

BugLink: http://bugs.launchpad.net/bugs/1666197
In the current code for powernv_add_idle_states, there is a lot of code
duplication while initializing an idle state in powernv_states table.

Add an inline helper function to populate the powernv_states[] table
for a given idle state. Invoke this for populating the "Nap",
"Fastsleep" and the stop states in powernv_add_idle_states.

Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
(cherry picked from linux-next commit 9e9fc6f00a54f7064dc681ac187be6498d566a4f)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c
index 0835a37a5f3a66854f169bf6314fb3b945a52081..6871b7f34dc8bedbb39683f24d84be167276705a 100644 (file)
--- a/drivers/cpuidle/cpuidle-powernv.c
+++ b/drivers/cpuidle/cpuidle-powernv.c
@@ -20,6 +20,10 @@
 #include <asm/opal.h>
 #include <asm/runlatch.h>
 
+/*
+ * Expose only those Hardware idle states via the cpuidle framework
+ * that have latency value below POWERNV_THRESHOLD_LATENCY_NS.
+ */
 #define POWERNV_THRESHOLD_LATENCY_NS 200000
 
 static struct cpuidle_driver powernv_idle_driver = {
@@ -167,6 +171,24 @@ static int powernv_cpuidle_driver_init(void)
        return 0;
 }
 
+static inline void add_powernv_state(int index, const char *name,
+                                    unsigned int flags,
+                                    int (*idle_fn)(struct cpuidle_device *,
+                                                   struct cpuidle_driver *,
+                                                   int),
+                                    unsigned int target_residency,
+                                    unsigned int exit_latency,
+                                    u64 psscr_val)
+{
+       strlcpy(powernv_states[index].name, name, CPUIDLE_NAME_LEN);
+       strlcpy(powernv_states[index].desc, name, CPUIDLE_NAME_LEN);
+       powernv_states[index].flags = flags;
+       powernv_states[index].target_residency = target_residency;
+       powernv_states[index].exit_latency = exit_latency;
+       powernv_states[index].enter = idle_fn;
+       stop_psscr_table[index] = psscr_val;
+}
+
 static int powernv_add_idle_states(void)
 {
        struct device_node *power_mgt;
@@ -236,6 +258,7 @@ static int powernv_add_idle_states(void)
                "ibm,cpu-idle-state-residency-ns", residency_ns, dt_idle_states);
 
        for (i = 0; i < dt_idle_states; i++) {
+               unsigned int exit_latency, target_residency;
                /*
                 * If an idle state has exit latency beyond
                 * POWERNV_THRESHOLD_LATENCY_NS then don't use it
@@ -243,28 +266,33 @@ static int powernv_add_idle_states(void)
                 */
                if (latency_ns[i] > POWERNV_THRESHOLD_LATENCY_NS)
                        continue;
+               /*
+                * Firmware passes residency and latency values in ns.
+                * cpuidle expects it in us.
+                */
+               exit_latency = latency_ns[i] / 1000;
+               if (!rc)
+                       target_residency = residency_ns[i] / 1000;
+               else
+                       target_residency = 0;
 
                /*
-                * Cpuidle accepts exit_latency and target_residency in us.
-                * Use default target_residency values if f/w does not expose it.
+                * For nap and fastsleep, use default target_residency
+                * values if f/w does not expose it.
                 */
                if (flags[i] & OPAL_PM_NAP_ENABLED) {
+                       if (!rc)
+                               target_residency = 100;
                        /* 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].target_residency = 100;
-                       powernv_states[nr_idle_states].enter = nap_loop;
+                       add_powernv_state(nr_idle_states, "Nap",
+                                         CPUIDLE_FLAG_NONE, nap_loop,
+                                         target_residency, exit_latency, 0);
                } else if ((flags[i] & OPAL_PM_STOP_INST_FAST) &&
                                !(flags[i] & OPAL_PM_TIMEBASE_STOP)) {
-                       strncpy(powernv_states[nr_idle_states].name,
-                               names[i], CPUIDLE_NAME_LEN);
-                       strncpy(powernv_states[nr_idle_states].desc,
-                               names[i], CPUIDLE_NAME_LEN);
-                       powernv_states[nr_idle_states].flags = 0;
-
-                       powernv_states[nr_idle_states].enter = stop_loop;
-                       stop_psscr_table[nr_idle_states] = psscr_val[i];
+                       add_powernv_state(nr_idle_states, names[i],
+                                         CPUIDLE_FLAG_NONE, stop_loop,
+                                         target_residency, exit_latency,
+                                         psscr_val[i]);
                }
 
                /*
@@ -274,32 +302,21 @@ static int powernv_add_idle_states(void)
 #ifdef CONFIG_TICK_ONESHOT
                if (flags[i] & OPAL_PM_SLEEP_ENABLED ||
                        flags[i] & OPAL_PM_SLEEP_ENABLED_ER1) {
+                       if (!rc)
+                               target_residency = 300000;
                        /* 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].target_residency = 300000;
-                       powernv_states[nr_idle_states].enter = fastsleep_loop;
+                       add_powernv_state(nr_idle_states, "FastSleep",
+                                         CPUIDLE_FLAG_TIMER_STOP,
+                                         fastsleep_loop,
+                                         target_residency, exit_latency, 0);
                } else if ((flags[i] & OPAL_PM_STOP_INST_DEEP) &&
                                (flags[i] & OPAL_PM_TIMEBASE_STOP)) {
-                       strncpy(powernv_states[nr_idle_states].name,
-                               names[i], CPUIDLE_NAME_LEN);
-                       strncpy(powernv_states[nr_idle_states].desc,
-                               names[i], CPUIDLE_NAME_LEN);
-
-                       powernv_states[nr_idle_states].flags = CPUIDLE_FLAG_TIMER_STOP;
-                       powernv_states[nr_idle_states].enter = stop_loop;
-                       stop_psscr_table[nr_idle_states] = psscr_val[i];
+                       add_powernv_state(nr_idle_states, names[i],
+                                         CPUIDLE_FLAG_TIMER_STOP, stop_loop,
+                                         target_residency, exit_latency,
+                                         psscr_val[i]);
                }
 #endif
-               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++;
        }
 out:

diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index da346f2817a842dfcd5552c4644961fcc024a3d8..fc1e5d7fc1c7bf9d9749145597312440c1b63fe8 100644 (file)
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -62,6 +62,7 @@ struct cpuidle_state {
 };
 
 /* Idle State Flags */
+#define CPUIDLE_FLAG_NONE       (0x00)
 #define CPUIDLE_FLAG_COUPLED   (0x02) /* state applies to multiple cpus */
 #define CPUIDLE_FLAG_TIMER_STOP (0x04)  /* timer is stopped on this state */