> -----Original Message-----
> From: Deepthi Dharwar [mailto:deep...@linux.vnet.ibm.com]
> Sent: Wednesday, July 31, 2013 10:59 AM
> To: b...@kernel.crashing.org; daniel.lezc...@linaro.org; linux-
> ker...@vger.kernel.org; mich...@ellerman.id.au;
> srivatsa.b...@linux.vnet.ibm.com; pre...@linux.vnet.ibm.com;
> sva...@linux.vnet.ibm.com; linuxppc-dev@lists.ozlabs.org
> Cc: r...@sisk.pl; Wang Dongsheng-B40534; linux...@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 <deep...@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 <deep...@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 <deep...@linux.vnet.ibm.com>");
> +MODULE_DESCRIPTION("Cpuidle driver for POWER");
> +MODULE_LICENSE("GPL");
> 

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