[PATCH 3/6] cpuidle:powernv: Add helper function to populate powernv idle states.
Tim Gardner
tim.gardner at canonical.com
Fri Mar 10 13:15:47 UTC 2017
From: "Gautham R. Shenoy" <ego at linux.vnet.ibm.com>
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.
Cherry-picked from upstream commit 9e9fc6f00a54 ("cpuidle:powernv: Add
helper function to populate powernv idle states.)
Signed-off-by: Gautham R. Shenoy <ego at linux.vnet.ibm.com>
Acked-by: Balbir Singh <bsingharora at gmail.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
Signed-off-by: Tim Gardner <tim.gardner at canonical.com>
---
drivers/cpuidle/cpuidle-powernv.c | 89 +++++++++++++++++++++++----------------
include/linux/cpuidle.h | 1 +
2 files changed, 54 insertions(+), 36 deletions(-)
diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c
index f7ca891..0a9d67c 100644
--- 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
struct cpuidle_driver powernv_idle_driver = {
@@ -177,6 +181,24 @@ 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;
@@ -246,6 +268,7 @@ 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
@@ -253,28 +276,33 @@ 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]);
}
/*
@@ -284,32 +312,21 @@ 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 bb31373..c4e10f8 100644
--- 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 */
--
2.7.4
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