[PATCH V2 5/6] cpuidle/powerpc: Backend-powerpc idle driver forpowernv and pseries.

From: Deepthi Dharwar
Date: Tue Jul 30 2013 - 23:01:00 EST


The following patch extends the current pseries backend
idle driver to powernv platform.

Signed-off-by: Deepthi Dharwar <deepthi@xxxxxxxxxxxxxxxxxx>
---
arch/powerpc/include/asm/processor.h | 2 -
arch/powerpc/sysdev/Kconfig | 8 +-
arch/powerpc/sysdev/Makefile | 2 -
arch/powerpc/sysdev/processor_idle.c | 132 ++++++++++++++++++++++------------
4 files changed, 92 insertions(+), 52 deletions(-)

diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 47a35b0..e64b817 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -426,7 +426,7 @@ enum idle_boot_override {IDLE_NO_OVERRIDE = 0, IDLE_POWERSAVE_OFF};
extern int powersave_nap; /* set if nap mode can be used in idle loop */
extern void power7_nap(void);

-#ifdef CONFIG_PSERIES_IDLE
+#ifdef CONFIG_POWERPC_IDLE
extern void update_smt_snooze_delay(int cpu, int residency);
#else
static inline void update_smt_snooze_delay(int cpu, int residency) {}
diff --git a/arch/powerpc/sysdev/Kconfig b/arch/powerpc/sysdev/Kconfig
index 8564a3f..f61d794 100644
--- a/arch/powerpc/sysdev/Kconfig
+++ b/arch/powerpc/sysdev/Kconfig
@@ -35,11 +35,11 @@ config GE_FPGA
bool
default n

-config PSERIES_IDLE
- bool "Cpuidle driver for pSeries platforms"
+config POWERPC_IDLE
+ bool "Cpuidle driver for POWERPC platforms"
depends on CPU_IDLE
- depends on PPC_PSERIES
+ depends on PPC_PSERIES || PPC_POWERNV
default y
help
Select this option to enable processor idle state management
- for pSeries through cpuidle subsystem.
+ for POWER and POWERNV through cpuidle subsystem.
diff --git a/arch/powerpc/sysdev/Makefile b/arch/powerpc/sysdev/Makefile
index 93d2cdd..ec290e2 100644
--- a/arch/powerpc/sysdev/Makefile
+++ b/arch/powerpc/sysdev/Makefile
@@ -49,7 +49,7 @@ endif
obj-$(CONFIG_PPC4xx_MSI) += ppc4xx_msi.o
obj-$(CONFIG_PPC4xx_CPM) += ppc4xx_cpm.o
obj-$(CONFIG_PPC4xx_GPIO) += ppc4xx_gpio.o
-obj-$(CONFIG_PSERIES_IDLE) += processor_idle.o
+obj-$(CONFIG_POWERPC_IDLE) += processor_idle.o

obj-$(CONFIG_CPM) += cpm_common.o
obj-$(CONFIG_CPM2) += cpm2.o cpm2_pic.o
diff --git a/arch/powerpc/sysdev/processor_idle.c b/arch/powerpc/sysdev/processor_idle.c
index 0d75a54..d152f540d 100644
--- a/arch/powerpc/sysdev/processor_idle.c
+++ b/arch/powerpc/sysdev/processor_idle.c
@@ -20,18 +20,18 @@
#include <asm/runlatch.h>
#include <asm/plpar_wrappers.h>

-/* Snooze Delay, pseries_idle */
+/* Snooze Delay, powerpc_idle */
DECLARE_PER_CPU(long, smt_snooze_delay);

-struct cpuidle_driver pseries_idle_driver = {
- .name = "pseries_idle",
+struct cpuidle_driver powerpc_idle_driver = {
+ .name = "powerpc_idle",
.owner = THIS_MODULE,
};

#define MAX_IDLE_STATE_COUNT 2

static int max_idle_state = MAX_IDLE_STATE_COUNT - 1;
-static struct cpuidle_device __percpu *pseries_cpuidle_devices;
+static struct cpuidle_device __percpu *powerpc_cpuidle_devices;
static struct cpuidle_state *cpuidle_state_table;

static inline void idle_loop_prolog(unsigned long *in_purr)
@@ -55,13 +55,14 @@ static int snooze_loop(struct cpuidle_device *dev,
int index)
{
unsigned long in_purr;
- int cpu = dev->cpu;

+#ifndef PPC_POWERNV
idle_loop_prolog(&in_purr);
+#endif
local_irq_enable();
set_thread_flag(TIF_POLLING_NRFLAG);

- while ((!need_resched()) && cpu_online(cpu)) {
+ while (!need_resched()) {
ppc64_runlatch_off();
HMT_low();
HMT_very_low();
@@ -71,7 +72,9 @@ static int snooze_loop(struct cpuidle_device *dev,
clear_thread_flag(TIF_POLLING_NRFLAG);
smp_mb();

+#ifndef PPC_POWERNV
idle_loop_epilog(in_purr);
+#endif

return index;
}
@@ -135,10 +138,21 @@ static int shared_cede_loop(struct cpuidle_device *dev,
return index;
}

+#ifdef PPC_POWERNV
+static int nap_loop(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv,
+ int index)
+{
+ ppc64_runlatch_off();
+ power7_idle();
+ return index;
+}
+#endif
+
/*
* States for dedicated partition case.
*/
-static struct cpuidle_state dedicated_states[MAX_IDLE_STATE_COUNT] = {
+static struct cpuidle_state pseries_dedicated_states[MAX_IDLE_STATE_COUNT] = {
{ /* Snooze */
.name = "snooze",
.desc = "snooze",
@@ -158,7 +172,7 @@ static struct cpuidle_state dedicated_states[MAX_IDLE_STATE_COUNT] = {
/*
* States for shared partition case.
*/
-static struct cpuidle_state shared_states[MAX_IDLE_STATE_COUNT] = {
+static struct cpuidle_state pseries_shared_states[MAX_IDLE_STATE_COUNT] = {
{ /* Shared Cede */
.name = "Shared Cede",
.desc = "Shared Cede",
@@ -168,13 +182,34 @@ static struct cpuidle_state shared_states[MAX_IDLE_STATE_COUNT] = {
.enter = &shared_cede_loop },
};

+#ifdef PPC_POWERNV
+static struct cpuidle_state powernv_states[MAX_IDLE_STATE_COUNT] = {
+ { /* Snooze */
+ .name = "snooze",
+ .desc = "snooze",
+ .flags = CPUIDLE_FLAG_TIME_VALID,
+ .exit_latency = 0,
+ .target_residency = 0,
+ .enter = &snooze_loop },
+ { /* CEDE */
+ .name = "CEDE",
+ .desc = "CEDE",
+ .flags = CPUIDLE_FLAG_TIME_VALID,
+ .exit_latency = 10,
+ .target_residency = 100,
+ .enter = &nap_loop },
+};
+#endif
+
void update_smt_snooze_delay(int cpu, int residency)
{
struct cpuidle_driver *drv = cpuidle_get_driver();
struct cpuidle_device *dev;

- if (cpuidle_state_table != dedicated_states)
+#ifndef PPC_POWERNV
+ if (cpuidle_state_table != pseries_dedicated_states)
return;
+#endif

if (!drv)
return;
@@ -204,12 +239,12 @@ void update_smt_snooze_delay(int cpu, int residency)
}
}

-static int pseries_cpuidle_add_cpu_notifier(struct notifier_block *n,
+static int powerpc_cpuidle_add_cpu_notifier(struct notifier_block *n,
unsigned long action, void *hcpu)
{
int hotcpu = (unsigned long)hcpu;
struct cpuidle_device *dev =
- per_cpu_ptr(pseries_cpuidle_devices, hotcpu);
+ per_cpu_ptr(powerpc_cpuidle_devices, hotcpu);

if (dev && cpuidle_get_driver()) {
switch (action) {
@@ -235,16 +270,16 @@ static int pseries_cpuidle_add_cpu_notifier(struct notifier_block *n,
}

static struct notifier_block setup_hotplug_notifier = {
- .notifier_call = pseries_cpuidle_add_cpu_notifier,
+ .notifier_call = powerpc_cpuidle_add_cpu_notifier,
};

/*
- * pseries_cpuidle_driver_init()
+ * powerpc_cpuidle_driver_init()
*/
-static int pseries_cpuidle_driver_init(void)
+static int powerpc_cpuidle_driver_init(void)
{
int idle_state;
- struct cpuidle_driver *drv = &pseries_idle_driver;
+ struct cpuidle_driver *drv = &powerpc_idle_driver;

drv->state_count = 0;

@@ -266,38 +301,38 @@ static int pseries_cpuidle_driver_init(void)
return 0;
}

-/* pseries_idle_devices_uninit(void)
+/* powerpc_idle_devices_uninit(void)
* unregister cpuidle devices and de-allocate memory
*/
-static void pseries_idle_devices_uninit(void)
+static void powerpc_idle_devices_uninit(void)
{
int i;
struct cpuidle_device *dev;

for_each_possible_cpu(i) {
- dev = per_cpu_ptr(pseries_cpuidle_devices, i);
+ dev = per_cpu_ptr(powerpc_cpuidle_devices, i);
cpuidle_unregister_device(dev);
}

- free_percpu(pseries_cpuidle_devices);
+ free_percpu(powerpc_cpuidle_devices);
return;
}

-/* pseries_idle_devices_init()
+/* powerpc_idle_devices_init()
* allocate, initialize and register cpuidle device
*/
-static int pseries_idle_devices_init(void)
+static int powerpc_idle_devices_init(void)
{
int i;
- struct cpuidle_driver *drv = &pseries_idle_driver;
+ struct cpuidle_driver *drv = &powerpc_idle_driver;
struct cpuidle_device *dev;

- pseries_cpuidle_devices = alloc_percpu(struct cpuidle_device);
- if (pseries_cpuidle_devices == NULL)
+ powerpc_cpuidle_devices = alloc_percpu(struct cpuidle_device);
+ if (powerpc_cpuidle_devices == NULL)
return -ENOMEM;

for_each_possible_cpu(i) {
- dev = per_cpu_ptr(pseries_cpuidle_devices, i);
+ dev = per_cpu_ptr(powerpc_cpuidle_devices, i);
dev->state_count = drv->state_count;
dev->cpu = i;
if (cpuidle_register_device(dev)) {
@@ -311,74 +346,79 @@ static int pseries_idle_devices_init(void)
}

/*
- * pseries_idle_probe()
+ * powerpc_idle_probe()
* Choose state table for shared versus dedicated partition
*/
-static int pseries_idle_probe(void)
+static int powerpc_idle_probe(void)
{

+#ifndef PPC_POWERNV
if (!firmware_has_feature(FW_FEATURE_SPLPAR))
return -ENODEV;
+#endif

if (cpuidle_disable != IDLE_NO_OVERRIDE)
return -ENODEV;

if (max_idle_state == 0) {
- printk(KERN_DEBUG "pseries processor idle disabled.\n");
+ printk(KERN_DEBUG "powerpc processor idle disabled.\n");
return -EPERM;
}

+#ifdef PPC_POWERNV
+ cpuidle_state_table = powernv_states;
+#else
if (get_lppaca()->shared_proc)
- cpuidle_state_table = shared_states;
+ cpuidle_state_table = pseries_shared_states;
else
- cpuidle_state_table = dedicated_states;
-
+ cpuidle_state_table = pseries_dedicated_states;
+#endif
return 0;
}

-static int __init pseries_processor_idle_init(void)
+static int __init powerpc_processor_idle_init(void)
{
int retval;

- retval = pseries_idle_probe();
+ retval = powerpc_idle_probe();
if (retval)
return retval;

- pseries_cpuidle_driver_init();
- retval = cpuidle_register_driver(&pseries_idle_driver);
+ powerpc_cpuidle_driver_init();
+ retval = cpuidle_register_driver(&powerpc_idle_driver);
if (retval) {
- printk(KERN_DEBUG "Registration of pseries driver failed.\n");
+ printk(KERN_DEBUG "Registration of powerpc driver failed.\n");
return retval;
}

update_smt_snooze_delay(-1, per_cpu(smt_snooze_delay, 0));

- retval = pseries_idle_devices_init();
+ retval = powerpc_idle_devices_init();
if (retval) {
- pseries_idle_devices_uninit();
- cpuidle_unregister_driver(&pseries_idle_driver);
+ powerpc_idle_devices_uninit();
+ cpuidle_unregister_driver(&powerpc_idle_driver);
return retval;
}

register_cpu_notifier(&setup_hotplug_notifier);
- printk(KERN_DEBUG "pseries_idle_driver registered\n");
+ printk(KERN_DEBUG "powerpc_idle_driver registered\n");

return 0;
}

-static void __exit pseries_processor_idle_exit(void)
+static void __exit powerpc_processor_idle_exit(void)
{

unregister_cpu_notifier(&setup_hotplug_notifier);
- pseries_idle_devices_uninit();
- cpuidle_unregister_driver(&pseries_idle_driver);
+ powerpc_idle_devices_uninit();
+ cpuidle_unregister_driver(&powerpc_idle_driver);

return;
}

-module_init(pseries_processor_idle_init);
-module_exit(pseries_processor_idle_exit);
+module_init(powerpc_processor_idle_init);
+module_exit(powerpc_processor_idle_exit);

MODULE_AUTHOR("Deepthi Dharwar <deepthi@xxxxxxxxxxxxxxxxxx>");
-MODULE_DESCRIPTION("Cpuidle driver for POWER");
+MODULE_DESCRIPTION("Cpuidle driver for POWERPC");
MODULE_LICENSE("GPL");

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