diff options
| -rw-r--r-- | arch/powerpc/include/asm/system.h | 8 | ||||
| -rw-r--r-- | arch/powerpc/kernel/sysfs.c | 2 | ||||
| -rw-r--r-- | arch/powerpc/platforms/pseries/Kconfig | 9 | ||||
| -rw-r--r-- | arch/powerpc/platforms/pseries/Makefile | 1 | ||||
| -rw-r--r-- | arch/powerpc/platforms/pseries/processor_idle.c | 326 | ||||
| -rw-r--r-- | arch/powerpc/platforms/pseries/pseries.h | 3 | ||||
| -rw-r--r-- | arch/powerpc/platforms/pseries/setup.c | 3 | ||||
| -rw-r--r-- | arch/powerpc/platforms/pseries/smp.c | 1 |
8 files changed, 350 insertions, 3 deletions
diff --git a/arch/powerpc/include/asm/system.h b/arch/powerpc/include/asm/system.h index ff666803879..f56a0a75d98 100644 --- a/arch/powerpc/include/asm/system.h +++ b/arch/powerpc/include/asm/system.h @@ -223,6 +223,14 @@ extern void *zalloc_maybe_bootmem(size_t size, gfp_t mask); extern int powersave_nap; /* set if nap mode can be used in idle loop */ void cpu_idle_wait(void); +#ifdef CONFIG_PSERIES_IDLE +extern void update_smt_snooze_delay(int snooze); +extern int pseries_notify_cpuidle_add_cpu(int cpu); +#else +static inline void update_smt_snooze_delay(int snooze) {} +static inline int pseries_notify_cpuidle_add_cpu(int cpu) { return 0; } +#endif + /* * Atomic exchange * diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c index f579be55209..6fdf5ffe8c4 100644 --- a/arch/powerpc/kernel/sysfs.c +++ b/arch/powerpc/kernel/sysfs.c @@ -18,6 +18,7 @@ #include <asm/machdep.h> #include <asm/smp.h> #include <asm/pmc.h> +#include <asm/system.h> #include "cacheinfo.h" @@ -51,6 +52,7 @@ static ssize_t store_smt_snooze_delay(struct sys_device *dev, return -EINVAL; per_cpu(smt_snooze_delay, cpu->sysdev.id) = snooze; + update_smt_snooze_delay(snooze); return count; } diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig index c81f6bb9c10..ae7b6d41fed 100644 --- a/arch/powerpc/platforms/pseries/Kconfig +++ b/arch/powerpc/platforms/pseries/Kconfig @@ -120,3 +120,12 @@ config DTL which are accessible through a debugfs file. Say N if you are unsure. + +config PSERIES_IDLE + tristate "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 3556e402cbf..236db46b407 100644 --- a/arch/powerpc/platforms/pseries/Makefile +++ b/arch/powerpc/platforms/pseries/Makefile @@ -22,6 +22,7 @@ obj-$(CONFIG_PHYP_DUMP) += phyp_dump.o obj-$(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 new file mode 100644 index 00000000000..f7e3e877cb6 --- /dev/null +++ b/arch/powerpc/platforms/pseries/processor_idle.c @@ -0,0 +1,326 @@ +/* + * 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 <asm/paca.h> +#include <asm/reg.h> +#include <asm/system.h> +#include <asm/machdep.h> +#include <asm/firmware.h> + +#include "plpar_wrappers.h" +#include "pseries.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; + +void update_smt_snooze_delay(int snooze) +{ + struct cpuidle_driver *drv = cpuidle_get_driver(); + if (drv) + drv->states[0].target_residency = snooze; +} + +static inline void idle_loop_prolog(unsigned long *in_purr, ktime_t *kt_before) +{ + + *kt_before = ktime_get_real(); + *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 s64 idle_loop_epilog(unsigned long in_purr, ktime_t kt_before) +{ + get_lppaca()->wait_state_cycles += mfspr(SPRN_PURR) - in_purr; + get_lppaca()->idle = 0; + + return ktime_to_us(ktime_sub(ktime_get_real(), kt_before)); +} + +static int snooze_loop(struct cpuidle_device *dev, + struct cpuidle_driver *drv, + int index) +{ + unsigned long in_purr; + ktime_t kt_before; + unsigned long start_snooze; + long snooze = drv->states[0].target_residency; + + idle_loop_prolog(&in_purr, &kt_before); + + if (snooze) { + start_snooze = get_tb() + snooze * tb_ticks_per_usec; + local_irq_enable(); + set_thread_flag(TIF_POLLING_NRFLAG); + + while ((snooze < 0) || (get_tb() < start_snooze)) { + if (need_resched() || cpu_is_offline(dev->cpu)) + goto out; + ppc64_runlatch_off(); + HMT_low(); + HMT_very_low(); + } + + HMT_medium(); + clear_thread_flag(TIF_POLLING_NRFLAG); + smp_mb(); + local_irq_disable(); + } + +out: + HMT_medium(); + dev->last_residency = + (int)idle_loop_epilog(in_purr, kt_before); + return index; +} + +static int dedicated_cede_loop(struct cpuidle_device *dev, + struct cpuidle_driver *drv, + int index) +{ + unsigned long in_purr; + ktime_t kt_before; + + idle_loop_prolog(&in_purr, &kt_before); + get_lppaca()->donate_dedicated_cpu = 1; + + ppc64_runlatch_off(); + HMT_medium(); + cede_processor(); + + get_lppaca()->donate_dedicated_cpu = 0; + dev->last_residency = + (int)idle_loop_epilog(in_purr, kt_before); + return index; +} + +static int shared_cede_loop(struct cpuidle_device *dev, + struct cpuidle_driver *drv, + int index) +{ + unsigned long in_purr; + ktime_t kt_before; + + idle_loop_prolog(&in_purr, &kt_before); + + /* + * 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. + */ + cede_processor(); + + dev->last_residency = + (int)idle_loop_epilog(in_purr, kt_before); + 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 = 1, + .target_residency = 10, + .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 }, +}; + +int pseries_notify_cpuidle_add_cpu(int cpu) +{ + struct cpuidle_device *dev = + per_cpu_ptr(pseries_cpuidle_devices, cpu); + if (dev && cpuidle_get_driver()) { + cpuidle_disable_device(dev); + cpuidle_enable_device(dev); + } + return 0; +} + +/* + * 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]; + + if (cpuidle_state_table == dedicated_states) + drv->states[drv->state_count].target_residency = + __get_cpu_var(smt_snooze_delay); + + 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 (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; + } + + retval = pseries_idle_devices_init(); + if (retval) { + pseries_idle_devices_uninit(); + cpuidle_unregister_driver(&pseries_idle_driver); + return retval; + } + + printk(KERN_DEBUG "pseries_idle_driver registered\n"); + + return 0; +} + +static void __exit pseries_processor_idle_exit(void) +{ + + 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/platforms/pseries/pseries.h b/arch/powerpc/platforms/pseries/pseries.h index 24c7162f11d..9a3dda07566 100644 --- a/arch/powerpc/platforms/pseries/pseries.h +++ b/arch/powerpc/platforms/pseries/pseries.h @@ -57,4 +57,7 @@ extern struct device_node *dlpar_configure_connector(u32); extern int dlpar_attach_node(struct device_node *); extern int dlpar_detach_node(struct device_node *); +/* Snooze Delay, pseries_idle */ +DECLARE_PER_CPU(long, smt_snooze_delay); + #endif /* _PSERIES_PSERIES_H */ diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c index 01df08dbc43..f2446da7f2d 100644 --- a/arch/powerpc/platforms/pseries/setup.c +++ b/arch/powerpc/platforms/pseries/setup.c @@ -585,9 +585,6 @@ static int __init pSeries_probe(void) return 1; } - -DECLARE_PER_CPU(long, smt_snooze_delay); - static void pseries_dedicated_idle_sleep(void) { unsigned int cpu = smp_processor_id(); diff --git a/arch/powerpc/platforms/pseries/smp.c b/arch/powerpc/platforms/pseries/smp.c index 26e93fd4c62..bbc3c42f673 100644 --- a/arch/powerpc/platforms/pseries/smp.c +++ b/arch/powerpc/platforms/pseries/smp.c @@ -148,6 +148,7 @@ static void __devinit smp_xics_setup_cpu(int cpu) set_cpu_current_state(cpu, CPU_STATE_ONLINE); set_default_offline_state(cpu); #endif + pseries_notify_cpuidle_add_cpu(cpu); } static int __devinit smp_pSeries_kick_cpu(int nr) |