[PATCH V7 1/7] pseries/cpuidle: Move processor_idle.c to drivers/cpuidle.
Daniel Lezcano
daniel.lezcano at linaro.org
Thu Nov 7 07:58:44 EST 2013
On 10/29/2013 12:01 PM, Deepthi Dharwar wrote:
> Move the file from arch specific pseries/processor_idle.c
> to drivers/cpuidle/cpuidle-ibm-power.c
> Make the relevant Makefile and Kconfig changes.
> This will enable having a common backend cpuidle driver
> for POWER platform going forward.
>
> Signed-off-by: Deepthi Dharwar <deepthi at linux.vnet.ibm.com>
Acked-by: Daniel Lezcano <daniel.lezcano at linaro.org>
> ---
> arch/powerpc/include/asm/processor.h | 2
> arch/powerpc/platforms/pseries/Kconfig | 9 -
> arch/powerpc/platforms/pseries/Makefile | 1
> arch/powerpc/platforms/pseries/processor_idle.c | 364 -----------------------
> drivers/cpuidle/Kconfig | 5
> drivers/cpuidle/Kconfig.powerpc | 10 +
> drivers/cpuidle/Makefile | 4
> drivers/cpuidle/cpuidle-ibm-power.c | 364 +++++++++++++++++++++++
> 8 files changed, 384 insertions(+), 375 deletions(-)
> delete mode 100644 arch/powerpc/platforms/pseries/processor_idle.c
> create mode 100644 drivers/cpuidle/Kconfig.powerpc
> create mode 100644 drivers/cpuidle/cpuidle-ibm-power.c
>
> diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
> index ce4de5a..d53bb88 100644
> --- a/arch/powerpc/include/asm/processor.h
> +++ b/arch/powerpc/include/asm/processor.h
> @@ -428,7 +428,7 @@ 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_CPU_IDLE_IBM_POWER
> 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/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig
> index 62b4f80..bb59bb0 100644
> --- a/arch/powerpc/platforms/pseries/Kconfig
> +++ b/arch/powerpc/platforms/pseries/Kconfig
> @@ -119,12 +119,3 @@ config DTL
> which are accessible through a debugfs file.
>
> Say N if you are unsure.
> -
> -config PSERIES_IDLE
> - bool "Cpuidle driver for pSeries platforms"
> - depends on CPU_IDLE
> - depends on PPC_PSERIES
> - default y
> - help
> - Select this option to enable processor idle state management
> - through cpuidle subsystem.
> diff --git a/arch/powerpc/platforms/pseries/Makefile b/arch/powerpc/platforms/pseries/Makefile
> index 6c61ec5..6f2500b 100644
> --- a/arch/powerpc/platforms/pseries/Makefile
> +++ b/arch/powerpc/platforms/pseries/Makefile
> @@ -21,7 +21,6 @@ obj-$(CONFIG_HCALL_STATS) += hvCall_inst.o
> obj-$(CONFIG_CMM) += cmm.o
> obj-$(CONFIG_DTL) += dtl.o
> obj-$(CONFIG_IO_EVENT_IRQ) += io_event_irq.o
> -obj-$(CONFIG_PSERIES_IDLE) += processor_idle.o
> obj-$(CONFIG_LPARCFG) += lparcfg.o
>
> ifeq ($(CONFIG_PPC_PSERIES),y)
> diff --git a/arch/powerpc/platforms/pseries/processor_idle.c b/arch/powerpc/platforms/pseries/processor_idle.c
> deleted file mode 100644
> index a166e38..0000000
> --- a/arch/powerpc/platforms/pseries/processor_idle.c
> +++ /dev/null
> @@ -1,364 +0,0 @@
> -/*
> - * processor_idle - idle state cpuidle driver.
> - * Adapted from drivers/idle/intel_idle.c and
> - * drivers/acpi/processor_idle.c
> - *
> - */
> -
> -#include <linux/kernel.h>
> -#include <linux/module.h>
> -#include <linux/init.h>
> -#include <linux/moduleparam.h>
> -#include <linux/cpuidle.h>
> -#include <linux/cpu.h>
> -#include <linux/notifier.h>
> -
> -#include <asm/paca.h>
> -#include <asm/reg.h>
> -#include <asm/machdep.h>
> -#include <asm/firmware.h>
> -#include <asm/runlatch.h>
> -#include <asm/plpar_wrappers.h>
> -
> -struct cpuidle_driver pseries_idle_driver = {
> - .name = "pseries_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_state *cpuidle_state_table;
> -
> -static inline void idle_loop_prolog(unsigned long *in_purr)
> -{
> - *in_purr = mfspr(SPRN_PURR);
> - /*
> - * Indicate to the HV that we are idle. Now would be
> - * a good time to find other work to dispatch.
> - */
> - get_lppaca()->idle = 1;
> -}
> -
> -static inline void idle_loop_epilog(unsigned long in_purr)
> -{
> - u64 wait_cycles;
> -
> - wait_cycles = be64_to_cpu(get_lppaca()->wait_state_cycles);
> - wait_cycles += mfspr(SPRN_PURR) - in_purr;
> - get_lppaca()->wait_state_cycles = cpu_to_be64(wait_cycles);
> - get_lppaca()->idle = 0;
> -}
> -
> -static int snooze_loop(struct cpuidle_device *dev,
> - struct cpuidle_driver *drv,
> - int index)
> -{
> - unsigned long in_purr;
> - int cpu = dev->cpu;
> -
> - idle_loop_prolog(&in_purr);
> - local_irq_enable();
> - set_thread_flag(TIF_POLLING_NRFLAG);
> -
> - while ((!need_resched()) && cpu_online(cpu)) {
> - ppc64_runlatch_off();
> - HMT_low();
> - HMT_very_low();
> - }
> -
> - HMT_medium();
> - clear_thread_flag(TIF_POLLING_NRFLAG);
> - smp_mb();
> -
> - idle_loop_epilog(in_purr);
> -
> - return index;
> -}
> -
> -static void check_and_cede_processor(void)
> -{
> - /*
> - * Ensure our interrupt state is properly tracked,
> - * also checks if no interrupt has occurred while we
> - * were soft-disabled
> - */
> - if (prep_irq_for_idle()) {
> - cede_processor();
> -#ifdef CONFIG_TRACE_IRQFLAGS
> - /* Ensure that H_CEDE returns with IRQs on */
> - if (WARN_ON(!(mfmsr() & MSR_EE)))
> - __hard_irq_enable();
> -#endif
> - }
> -}
> -
> -static int dedicated_cede_loop(struct cpuidle_device *dev,
> - struct cpuidle_driver *drv,
> - int index)
> -{
> - unsigned long in_purr;
> -
> - idle_loop_prolog(&in_purr);
> - get_lppaca()->donate_dedicated_cpu = 1;
> -
> - ppc64_runlatch_off();
> - HMT_medium();
> - check_and_cede_processor();
> -
> - get_lppaca()->donate_dedicated_cpu = 0;
> -
> - idle_loop_epilog(in_purr);
> -
> - return index;
> -}
> -
> -static int shared_cede_loop(struct cpuidle_device *dev,
> - struct cpuidle_driver *drv,
> - int index)
> -{
> - unsigned long in_purr;
> -
> - idle_loop_prolog(&in_purr);
> -
> - /*
> - * Yield the processor to the hypervisor. We return if
> - * an external interrupt occurs (which are driven prior
> - * to returning here) or if a prod occurs from another
> - * processor. When returning here, external interrupts
> - * are enabled.
> - */
> - check_and_cede_processor();
> -
> - idle_loop_epilog(in_purr);
> -
> - return index;
> -}
> -
> -/*
> - * States for dedicated partition case.
> - */
> -static struct cpuidle_state dedicated_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 = &dedicated_cede_loop },
> -};
> -
> -/*
> - * States for shared partition case.
> - */
> -static struct cpuidle_state shared_states[MAX_IDLE_STATE_COUNT] = {
> - { /* Shared Cede */
> - .name = "Shared Cede",
> - .desc = "Shared Cede",
> - .flags = CPUIDLE_FLAG_TIME_VALID,
> - .exit_latency = 0,
> - .target_residency = 0,
> - .enter = &shared_cede_loop },
> -};
> -
> -void update_smt_snooze_delay(int cpu, int residency)
> -{
> - struct cpuidle_driver *drv = cpuidle_get_driver();
> - struct cpuidle_device *dev = per_cpu(cpuidle_devices, cpu);
> -
> - if (cpuidle_state_table != dedicated_states)
> - return;
> -
> - if (residency < 0) {
> - /* Disable the Nap state on that cpu */
> - if (dev)
> - dev->states_usage[1].disable = 1;
> - } else
> - if (drv)
> - drv->states[1].target_residency = residency;
> -}
> -
> -static int pseries_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);
> -
> - if (dev && cpuidle_get_driver()) {
> - switch (action) {
> - case CPU_ONLINE:
> - case CPU_ONLINE_FROZEN:
> - cpuidle_pause_and_lock();
> - cpuidle_enable_device(dev);
> - cpuidle_resume_and_unlock();
> - break;
> -
> - case CPU_DEAD:
> - case CPU_DEAD_FROZEN:
> - cpuidle_pause_and_lock();
> - cpuidle_disable_device(dev);
> - cpuidle_resume_and_unlock();
> - break;
> -
> - default:
> - return NOTIFY_DONE;
> - }
> - }
> - return NOTIFY_OK;
> -}
> -
> -static struct notifier_block setup_hotplug_notifier = {
> - .notifier_call = pseries_cpuidle_add_cpu_notifier,
> -};
> -
> -/*
> - * pseries_cpuidle_driver_init()
> - */
> -static int pseries_cpuidle_driver_init(void)
> -{
> - int idle_state;
> - struct cpuidle_driver *drv = &pseries_idle_driver;
> -
> - drv->state_count = 0;
> -
> - for (idle_state = 0; idle_state < MAX_IDLE_STATE_COUNT; ++idle_state) {
> -
> - if (idle_state > max_idle_state)
> - break;
> -
> - /* is the state not enabled? */
> - if (cpuidle_state_table[idle_state].enter == NULL)
> - continue;
> -
> - drv->states[drv->state_count] = /* structure copy */
> - cpuidle_state_table[idle_state];
> -
> - drv->state_count += 1;
> - }
> -
> - return 0;
> -}
> -
> -/* pseries_idle_devices_uninit(void)
> - * unregister cpuidle devices and de-allocate memory
> - */
> -static void pseries_idle_devices_uninit(void)
> -{
> - int i;
> - struct cpuidle_device *dev;
> -
> - for_each_possible_cpu(i) {
> - dev = per_cpu_ptr(pseries_cpuidle_devices, i);
> - cpuidle_unregister_device(dev);
> - }
> -
> - free_percpu(pseries_cpuidle_devices);
> - return;
> -}
> -
> -/* pseries_idle_devices_init()
> - * allocate, initialize and register cpuidle device
> - */
> -static int pseries_idle_devices_init(void)
> -{
> - int i;
> - struct cpuidle_driver *drv = &pseries_idle_driver;
> - struct cpuidle_device *dev;
> -
> - pseries_cpuidle_devices = alloc_percpu(struct cpuidle_device);
> - if (pseries_cpuidle_devices == NULL)
> - return -ENOMEM;
> -
> - for_each_possible_cpu(i) {
> - dev = per_cpu_ptr(pseries_cpuidle_devices, i);
> - dev->state_count = drv->state_count;
> - dev->cpu = i;
> - if (cpuidle_register_device(dev)) {
> - printk(KERN_DEBUG \
> - "cpuidle_register_device %d failed!\n", i);
> - return -EIO;
> - }
> - }
> -
> - return 0;
> -}
> -
> -/*
> - * pseries_idle_probe()
> - * Choose state table for shared versus dedicated partition
> - */
> -static int pseries_idle_probe(void)
> -{
> -
> - if (!firmware_has_feature(FW_FEATURE_SPLPAR))
> - return -ENODEV;
> -
> - if (cpuidle_disable != IDLE_NO_OVERRIDE)
> - return -ENODEV;
> -
> - if (max_idle_state == 0) {
> - printk(KERN_DEBUG "pseries processor idle disabled.\n");
> - return -EPERM;
> - }
> -
> - if (lppaca_shared_proc(get_lppaca()))
> - cpuidle_state_table = shared_states;
> - else
> - cpuidle_state_table = dedicated_states;
> -
> - return 0;
> -}
> -
> -static int __init pseries_processor_idle_init(void)
> -{
> - int retval;
> -
> - retval = pseries_idle_probe();
> - if (retval)
> - return retval;
> -
> - pseries_cpuidle_driver_init();
> - retval = cpuidle_register_driver(&pseries_idle_driver);
> - if (retval) {
> - printk(KERN_DEBUG "Registration of pseries driver failed.\n");
> - return retval;
> - }
> -
> - retval = pseries_idle_devices_init();
> - if (retval) {
> - pseries_idle_devices_uninit();
> - cpuidle_unregister_driver(&pseries_idle_driver);
> - return retval;
> - }
> -
> - register_cpu_notifier(&setup_hotplug_notifier);
> - printk(KERN_DEBUG "pseries_idle_driver registered\n");
> -
> - return 0;
> -}
> -
> -static void __exit pseries_processor_idle_exit(void)
> -{
> -
> - unregister_cpu_notifier(&setup_hotplug_notifier);
> - pseries_idle_devices_uninit();
> - cpuidle_unregister_driver(&pseries_idle_driver);
> -
> - return;
> -}
> -
> -module_init(pseries_processor_idle_init);
> -module_exit(pseries_processor_idle_exit);
> -
> -MODULE_AUTHOR("Deepthi Dharwar <deepthi at linux.vnet.ibm.com>");
> -MODULE_DESCRIPTION("Cpuidle driver for POWER");
> -MODULE_LICENSE("GPL");
> diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig
> index b3fb81d..f04e25f 100644
> --- a/drivers/cpuidle/Kconfig
> +++ b/drivers/cpuidle/Kconfig
> @@ -35,6 +35,11 @@ depends on ARM
> source "drivers/cpuidle/Kconfig.arm"
> endmenu
>
> +menu "POWERPC CPU Idle Drivers"
> +depends on PPC
> +source "drivers/cpuidle/Kconfig.powerpc"
> +endmenu
> +
> endif
>
> config ARCH_NEEDS_CPU_IDLE_COUPLED
> diff --git a/drivers/cpuidle/Kconfig.powerpc b/drivers/cpuidle/Kconfig.powerpc
> new file mode 100644
> index 0000000..8f43dc2
> --- /dev/null
> +++ b/drivers/cpuidle/Kconfig.powerpc
> @@ -0,0 +1,10 @@
> +#
> +# POWERPC CPU Idle Drivers
> +#
> +config CPU_IDLE_IBM_POWER
> + bool "CPU Idle driver for IBM POWER platforms"
> + depends on PPC_PSERIES
> + default y
> + help
> + Select this option to enable processor idle state management
> + on IBM POWER platform.
> diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile
> index cea5ef5..60e7a6c 100644
> --- a/drivers/cpuidle/Makefile
> +++ b/drivers/cpuidle/Makefile
> @@ -12,3 +12,7 @@ obj-$(CONFIG_ARM_KIRKWOOD_CPUIDLE) += cpuidle-kirkwood.o
> obj-$(CONFIG_ARM_ZYNQ_CPUIDLE) += cpuidle-zynq.o
> obj-$(CONFIG_ARM_U8500_CPUIDLE) += cpuidle-ux500.o
> obj-$(CONFIG_CPU_IDLE_BIG_LITTLE) += cpuidle-big_little.o
> +
> +###############################################################################
> +# POWERPC drivers
> +obj-$(CONFIG_CPU_IDLE_IBM_POWER) += cpuidle-ibm-power.o
> diff --git a/drivers/cpuidle/cpuidle-ibm-power.c b/drivers/cpuidle/cpuidle-ibm-power.c
> new file mode 100644
> index 0000000..a166e38
> --- /dev/null
> +++ b/drivers/cpuidle/cpuidle-ibm-power.c
> @@ -0,0 +1,364 @@
> +/*
> + * processor_idle - idle state cpuidle driver.
> + * Adapted from drivers/idle/intel_idle.c and
> + * drivers/acpi/processor_idle.c
> + *
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/moduleparam.h>
> +#include <linux/cpuidle.h>
> +#include <linux/cpu.h>
> +#include <linux/notifier.h>
> +
> +#include <asm/paca.h>
> +#include <asm/reg.h>
> +#include <asm/machdep.h>
> +#include <asm/firmware.h>
> +#include <asm/runlatch.h>
> +#include <asm/plpar_wrappers.h>
> +
> +struct cpuidle_driver pseries_idle_driver = {
> + .name = "pseries_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_state *cpuidle_state_table;
> +
> +static inline void idle_loop_prolog(unsigned long *in_purr)
> +{
> + *in_purr = mfspr(SPRN_PURR);
> + /*
> + * Indicate to the HV that we are idle. Now would be
> + * a good time to find other work to dispatch.
> + */
> + get_lppaca()->idle = 1;
> +}
> +
> +static inline void idle_loop_epilog(unsigned long in_purr)
> +{
> + u64 wait_cycles;
> +
> + wait_cycles = be64_to_cpu(get_lppaca()->wait_state_cycles);
> + wait_cycles += mfspr(SPRN_PURR) - in_purr;
> + get_lppaca()->wait_state_cycles = cpu_to_be64(wait_cycles);
> + get_lppaca()->idle = 0;
> +}
> +
> +static int snooze_loop(struct cpuidle_device *dev,
> + struct cpuidle_driver *drv,
> + int index)
> +{
> + unsigned long in_purr;
> + int cpu = dev->cpu;
> +
> + idle_loop_prolog(&in_purr);
> + local_irq_enable();
> + set_thread_flag(TIF_POLLING_NRFLAG);
> +
> + while ((!need_resched()) && cpu_online(cpu)) {
> + ppc64_runlatch_off();
> + HMT_low();
> + HMT_very_low();
> + }
> +
> + HMT_medium();
> + clear_thread_flag(TIF_POLLING_NRFLAG);
> + smp_mb();
> +
> + idle_loop_epilog(in_purr);
> +
> + return index;
> +}
> +
> +static void check_and_cede_processor(void)
> +{
> + /*
> + * Ensure our interrupt state is properly tracked,
> + * also checks if no interrupt has occurred while we
> + * were soft-disabled
> + */
> + if (prep_irq_for_idle()) {
> + cede_processor();
> +#ifdef CONFIG_TRACE_IRQFLAGS
> + /* Ensure that H_CEDE returns with IRQs on */
> + if (WARN_ON(!(mfmsr() & MSR_EE)))
> + __hard_irq_enable();
> +#endif
> + }
> +}
> +
> +static int dedicated_cede_loop(struct cpuidle_device *dev,
> + struct cpuidle_driver *drv,
> + int index)
> +{
> + unsigned long in_purr;
> +
> + idle_loop_prolog(&in_purr);
> + get_lppaca()->donate_dedicated_cpu = 1;
> +
> + ppc64_runlatch_off();
> + HMT_medium();
> + check_and_cede_processor();
> +
> + get_lppaca()->donate_dedicated_cpu = 0;
> +
> + idle_loop_epilog(in_purr);
> +
> + return index;
> +}
> +
> +static int shared_cede_loop(struct cpuidle_device *dev,
> + struct cpuidle_driver *drv,
> + int index)
> +{
> + unsigned long in_purr;
> +
> + idle_loop_prolog(&in_purr);
> +
> + /*
> + * Yield the processor to the hypervisor. We return if
> + * an external interrupt occurs (which are driven prior
> + * to returning here) or if a prod occurs from another
> + * processor. When returning here, external interrupts
> + * are enabled.
> + */
> + check_and_cede_processor();
> +
> + idle_loop_epilog(in_purr);
> +
> + return index;
> +}
> +
> +/*
> + * States for dedicated partition case.
> + */
> +static struct cpuidle_state dedicated_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 = &dedicated_cede_loop },
> +};
> +
> +/*
> + * States for shared partition case.
> + */
> +static struct cpuidle_state shared_states[MAX_IDLE_STATE_COUNT] = {
> + { /* Shared Cede */
> + .name = "Shared Cede",
> + .desc = "Shared Cede",
> + .flags = CPUIDLE_FLAG_TIME_VALID,
> + .exit_latency = 0,
> + .target_residency = 0,
> + .enter = &shared_cede_loop },
> +};
> +
> +void update_smt_snooze_delay(int cpu, int residency)
> +{
> + struct cpuidle_driver *drv = cpuidle_get_driver();
> + struct cpuidle_device *dev = per_cpu(cpuidle_devices, cpu);
> +
> + if (cpuidle_state_table != dedicated_states)
> + return;
> +
> + if (residency < 0) {
> + /* Disable the Nap state on that cpu */
> + if (dev)
> + dev->states_usage[1].disable = 1;
> + } else
> + if (drv)
> + drv->states[1].target_residency = residency;
> +}
> +
> +static int pseries_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);
> +
> + if (dev && cpuidle_get_driver()) {
> + switch (action) {
> + case CPU_ONLINE:
> + case CPU_ONLINE_FROZEN:
> + cpuidle_pause_and_lock();
> + cpuidle_enable_device(dev);
> + cpuidle_resume_and_unlock();
> + break;
> +
> + case CPU_DEAD:
> + case CPU_DEAD_FROZEN:
> + cpuidle_pause_and_lock();
> + cpuidle_disable_device(dev);
> + cpuidle_resume_and_unlock();
> + break;
> +
> + default:
> + return NOTIFY_DONE;
> + }
> + }
> + return NOTIFY_OK;
> +}
> +
> +static struct notifier_block setup_hotplug_notifier = {
> + .notifier_call = pseries_cpuidle_add_cpu_notifier,
> +};
> +
> +/*
> + * pseries_cpuidle_driver_init()
> + */
> +static int pseries_cpuidle_driver_init(void)
> +{
> + int idle_state;
> + struct cpuidle_driver *drv = &pseries_idle_driver;
> +
> + drv->state_count = 0;
> +
> + for (idle_state = 0; idle_state < MAX_IDLE_STATE_COUNT; ++idle_state) {
> +
> + if (idle_state > max_idle_state)
> + break;
> +
> + /* is the state not enabled? */
> + if (cpuidle_state_table[idle_state].enter == NULL)
> + continue;
> +
> + drv->states[drv->state_count] = /* structure copy */
> + cpuidle_state_table[idle_state];
> +
> + drv->state_count += 1;
> + }
> +
> + return 0;
> +}
> +
> +/* pseries_idle_devices_uninit(void)
> + * unregister cpuidle devices and de-allocate memory
> + */
> +static void pseries_idle_devices_uninit(void)
> +{
> + int i;
> + struct cpuidle_device *dev;
> +
> + for_each_possible_cpu(i) {
> + dev = per_cpu_ptr(pseries_cpuidle_devices, i);
> + cpuidle_unregister_device(dev);
> + }
> +
> + free_percpu(pseries_cpuidle_devices);
> + return;
> +}
> +
> +/* pseries_idle_devices_init()
> + * allocate, initialize and register cpuidle device
> + */
> +static int pseries_idle_devices_init(void)
> +{
> + int i;
> + struct cpuidle_driver *drv = &pseries_idle_driver;
> + struct cpuidle_device *dev;
> +
> + pseries_cpuidle_devices = alloc_percpu(struct cpuidle_device);
> + if (pseries_cpuidle_devices == NULL)
> + return -ENOMEM;
> +
> + for_each_possible_cpu(i) {
> + dev = per_cpu_ptr(pseries_cpuidle_devices, i);
> + dev->state_count = drv->state_count;
> + dev->cpu = i;
> + if (cpuidle_register_device(dev)) {
> + printk(KERN_DEBUG \
> + "cpuidle_register_device %d failed!\n", i);
> + return -EIO;
> + }
> + }
> +
> + return 0;
> +}
> +
> +/*
> + * pseries_idle_probe()
> + * Choose state table for shared versus dedicated partition
> + */
> +static int pseries_idle_probe(void)
> +{
> +
> + if (!firmware_has_feature(FW_FEATURE_SPLPAR))
> + return -ENODEV;
> +
> + if (cpuidle_disable != IDLE_NO_OVERRIDE)
> + return -ENODEV;
> +
> + if (max_idle_state == 0) {
> + printk(KERN_DEBUG "pseries processor idle disabled.\n");
> + return -EPERM;
> + }
> +
> + if (lppaca_shared_proc(get_lppaca()))
> + cpuidle_state_table = shared_states;
> + else
> + cpuidle_state_table = dedicated_states;
> +
> + return 0;
> +}
> +
> +static int __init pseries_processor_idle_init(void)
> +{
> + int retval;
> +
> + retval = pseries_idle_probe();
> + if (retval)
> + return retval;
> +
> + pseries_cpuidle_driver_init();
> + retval = cpuidle_register_driver(&pseries_idle_driver);
> + if (retval) {
> + printk(KERN_DEBUG "Registration of pseries driver failed.\n");
> + return retval;
> + }
> +
> + retval = pseries_idle_devices_init();
> + if (retval) {
> + pseries_idle_devices_uninit();
> + cpuidle_unregister_driver(&pseries_idle_driver);
> + return retval;
> + }
> +
> + register_cpu_notifier(&setup_hotplug_notifier);
> + printk(KERN_DEBUG "pseries_idle_driver registered\n");
> +
> + return 0;
> +}
> +
> +static void __exit pseries_processor_idle_exit(void)
> +{
> +
> + unregister_cpu_notifier(&setup_hotplug_notifier);
> + pseries_idle_devices_uninit();
> + cpuidle_unregister_driver(&pseries_idle_driver);
> +
> + return;
> +}
> +
> +module_init(pseries_processor_idle_init);
> +module_exit(pseries_processor_idle_exit);
> +
> +MODULE_AUTHOR("Deepthi Dharwar <deepthi at linux.vnet.ibm.com>");
> +MODULE_DESCRIPTION("Cpuidle driver for POWER");
> +MODULE_LICENSE("GPL");
>
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