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SubjectRE: [PATCH V2 4/6] cpuidle/pseries: Move the pseries_idle backend driver to sysdev.
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> -----Original Message-----
> From: Deepthi Dharwar [mailto:deepthi@linux.vnet.ibm.com]
> Sent: Wednesday, July 31, 2013 10:59 AM
> To: benh@kernel.crashing.org; daniel.lezcano@linaro.org; linux-
> kernel@vger.kernel.org; michael@ellerman.id.au;
> srivatsa.bhat@linux.vnet.ibm.com; preeti@linux.vnet.ibm.com;
> svaidy@linux.vnet.ibm.com; linuxppc-dev@lists.ozlabs.org
> Cc: rjw@sisk.pl; Wang Dongsheng-B40534; linux-pm@vger.kernel.org
> Subject: [PATCH V2 4/6] cpuidle/pseries: Move the pseries_idle backend
> driver to sysdev.
>
> Move pseries_idle backend driver code to arch/powerpc/sysdev
> so that the code can be used for a common driver for powernv
> and pseries. This removes a lot of code duplicacy.
>
Why not drivers/cpuidle/?

I think it should be move to drivers/cpuidle.

-dongsheng

> Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
> ---
> arch/powerpc/platforms/pseries/Kconfig | 9 -
> arch/powerpc/platforms/pseries/Makefile | 1
> arch/powerpc/platforms/pseries/processor_idle.c | 384 -----------------
> ------
> arch/powerpc/sysdev/Kconfig | 9 +
> arch/powerpc/sysdev/Makefile | 1
> arch/powerpc/sysdev/processor_idle.c | 384
> +++++++++++++++++++++++
> 6 files changed, 394 insertions(+), 394 deletions(-)
> delete mode 100644 arch/powerpc/platforms/pseries/processor_idle.c
> create mode 100644 arch/powerpc/sysdev/processor_idle.c
>
> 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 8ae0103..4b22379 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-$(CONFIG_PSERIES_IDLE) += processor_idle.o
>
> ifeq ($(CONFIG_PPC_PSERIES),y)
> obj-$(CONFIG_SUSPEND) += suspend.o
> diff --git a/arch/powerpc/platforms/pseries/processor_idle.c
> b/arch/powerpc/platforms/pseries/processor_idle.c
> deleted file mode 100644
> index 0d75a54..0000000
> --- a/arch/powerpc/platforms/pseries/processor_idle.c
> +++ /dev/null
> @@ -1,384 +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>
> -
> -/* Snooze Delay, pseries_idle */
> -DECLARE_PER_CPU(long, smt_snooze_delay);
> -
> -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)
> -{
> - get_lppaca()->wait_state_cycles += mfspr(SPRN_PURR) - in_purr;
> - 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;
> -
> - if (cpuidle_state_table != dedicated_states)
> - return;
> -
> - if (!drv)
> - return;
> -
> - if (cpu == -1) {
> - if (residency < 0) {
> - /* Disable NAP on all cpus */
> - drv->states[1].disabled = true;
> - return;
> - } else {
> - drv->states[1].target_residency = residency;
> - drv->states[1].disabled = false;
> - return;
> - }
> - }
> -
> - dev = per_cpu(cpuidle_devices, cpu);
> - if (!dev)
> - return;
> -
> - if (residency < 0)
> - dev->states_usage[1].disable = 1;
> - else {
> - drv->states[1].target_residency = residency;
> - drv->states[1].disabled = false;
> - dev->states_usage[1].disable = 0;
> - }
> -}
> -
> -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 (get_lppaca()->shared_proc)
> - 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;
> - }
> -
> - update_smt_snooze_delay(-1, per_cpu(smt_snooze_delay, 0));
> -
> - 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@linux.vnet.ibm.com>");
> -MODULE_DESCRIPTION("Cpuidle driver for POWER");
> -MODULE_LICENSE("GPL");
> diff --git a/arch/powerpc/sysdev/Kconfig b/arch/powerpc/sysdev/Kconfig
> index ab4cb54..8564a3f 100644
> --- a/arch/powerpc/sysdev/Kconfig
> +++ b/arch/powerpc/sysdev/Kconfig
> @@ -34,3 +34,12 @@ config SCOM_DEBUGFS
> config GE_FPGA
> bool
> default n
> +
> +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
> + for pSeries through cpuidle subsystem.
> diff --git a/arch/powerpc/sysdev/Makefile b/arch/powerpc/sysdev/Makefile
> index f67ac90..93d2cdd 100644
> --- a/arch/powerpc/sysdev/Makefile
> +++ b/arch/powerpc/sysdev/Makefile
> @@ -49,6 +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_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
> new file mode 100644
> index 0000000..0d75a54
> --- /dev/null
> +++ b/arch/powerpc/sysdev/processor_idle.c
> @@ -0,0 +1,384 @@
> +/*
> + * 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>
> +
> +/* Snooze Delay, pseries_idle */
> +DECLARE_PER_CPU(long, smt_snooze_delay);
> +
> +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)
> +{
> + get_lppaca()->wait_state_cycles += mfspr(SPRN_PURR) - in_purr;
> + 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;
> +
> + if (cpuidle_state_table != dedicated_states)
> + return;
> +
> + if (!drv)
> + return;
> +
> + if (cpu == -1) {
> + if (residency < 0) {
> + /* Disable NAP on all cpus */
> + drv->states[1].disabled = true;
> + return;
> + } else {
> + drv->states[1].target_residency = residency;
> + drv->states[1].disabled = false;
> + return;
> + }
> + }
> +
> + dev = per_cpu(cpuidle_devices, cpu);
> + if (!dev)
> + return;
> +
> + if (residency < 0)
> + dev->states_usage[1].disable = 1;
> + else {
> + drv->states[1].target_residency = residency;
> + drv->states[1].disabled = false;
> + dev->states_usage[1].disable = 0;
> + }
> +}
> +
> +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 (get_lppaca()->shared_proc)
> + 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;
> + }
> +
> + update_smt_snooze_delay(-1, per_cpu(smt_snooze_delay, 0));
> +
> + 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@linux.vnet.ibm.com>");
> +MODULE_DESCRIPTION("Cpuidle driver for POWER");
> +MODULE_LICENSE("GPL");
>

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