From e179816ce60033ce560b28e01bc555ed5116cbe9 Mon Sep 17 00:00:00 2001 From: Deepthi Dharwar Date: Wed, 30 Nov 2011 02:46:55 +0000 Subject: [PATCH] powerpc/cpuidle: Enable cpuidle and directly call cpuidle_idle_call() for pSeries This patch enables cpuidle for pSeries and pSeries_idle is directly called from the idle loop. As a result of pSeries_idle, cpuidle driver registered with cpuidle subsystem comes into action. On failure of loading of the driver or cpuidle framework default idle is executed as part of the function. This patch also removes the routines pseries_shared_idle_sleep and pseries_dedicated_idle_sleep as they are now implemented as part of pseries_idle cpuidle driver. Signed-off-by: Deepthi Dharwar Signed-off-by: Trinabh Gupta Signed-off-by: Arun R Bharadwaj Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/platforms/Kconfig | 6 ++ arch/powerpc/platforms/pseries/setup.c | 101 +++++-------------------- include/linux/cpuidle.h | 2 - 3 files changed, 23 insertions(+), 86 deletions(-) diff --git a/arch/powerpc/platforms/Kconfig b/arch/powerpc/platforms/Kconfig index 3fe6d927ad70..31e1adeaa92a 100644 --- a/arch/powerpc/platforms/Kconfig +++ b/arch/powerpc/platforms/Kconfig @@ -211,6 +211,12 @@ config PPC_PASEMI_CPUFREQ endmenu +menu "CPUIdle driver" + +source "drivers/cpuidle/Kconfig" + +endmenu + config PPC601_SYNC_FIX bool "Workarounds for PPC601 bugs" depends on 6xx && (PPC_PREP || PPC_PMAC) diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c index f2446da7f2d5..164839cb9fcd 100644 --- a/arch/powerpc/platforms/pseries/setup.c +++ b/arch/powerpc/platforms/pseries/setup.c @@ -39,6 +39,7 @@ #include #include #include +#include #include #include @@ -74,9 +75,6 @@ EXPORT_SYMBOL(CMO_PageSize); int fwnmi_active; /* TRUE if an FWNMI handler is present */ -static void pseries_shared_idle_sleep(void); -static void pseries_dedicated_idle_sleep(void); - static struct device_node *pSeries_mpic_node; static void pSeries_show_cpuinfo(struct seq_file *m) @@ -351,6 +349,21 @@ static int alloc_dispatch_log_kmem_cache(void) } early_initcall(alloc_dispatch_log_kmem_cache); +static void pSeries_idle(void) +{ + /* This would call on the cpuidle framework, and the back-end pseries + * driver to go to idle states + */ + if (cpuidle_idle_call()) { + /* On error, execute default handler + * to go into low thread priority and possibly + * low power mode. + */ + HMT_low(); + HMT_very_low(); + } +} + static void __init pSeries_setup_arch(void) { /* Discover PIC type and setup ppc_md accordingly */ @@ -373,18 +386,9 @@ static void __init pSeries_setup_arch(void) pSeries_nvram_init(); - /* Choose an idle loop */ if (firmware_has_feature(FW_FEATURE_SPLPAR)) { vpa_init(boot_cpuid); - if (get_lppaca()->shared_proc) { - printk(KERN_DEBUG "Using shared processor idle loop\n"); - ppc_md.power_save = pseries_shared_idle_sleep; - } else { - printk(KERN_DEBUG "Using dedicated idle loop\n"); - ppc_md.power_save = pseries_dedicated_idle_sleep; - } - } else { - printk(KERN_DEBUG "Using default idle loop\n"); + ppc_md.power_save = pSeries_idle; } if (firmware_has_feature(FW_FEATURE_LPAR)) @@ -585,77 +589,6 @@ static int __init pSeries_probe(void) return 1; } -static void pseries_dedicated_idle_sleep(void) -{ - unsigned int cpu = smp_processor_id(); - unsigned long start_snooze; - unsigned long in_purr, out_purr; - long snooze = __get_cpu_var(smt_snooze_delay); - - /* - * Indicate to the HV that we are idle. Now would be - * a good time to find other work to dispatch. - */ - get_lppaca()->idle = 1; - get_lppaca()->donate_dedicated_cpu = 1; - in_purr = mfspr(SPRN_PURR); - - /* - * We come in with interrupts disabled, and need_resched() - * has been checked recently. If we should poll for a little - * while, do so. - */ - 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(cpu)) - goto out; - ppc64_runlatch_off(); - HMT_low(); - HMT_very_low(); - } - - HMT_medium(); - clear_thread_flag(TIF_POLLING_NRFLAG); - smp_mb(); - local_irq_disable(); - if (need_resched() || cpu_is_offline(cpu)) - goto out; - } - - cede_processor(); - -out: - HMT_medium(); - out_purr = mfspr(SPRN_PURR); - get_lppaca()->wait_state_cycles += out_purr - in_purr; - get_lppaca()->donate_dedicated_cpu = 0; - get_lppaca()->idle = 0; -} - -static void pseries_shared_idle_sleep(void) -{ - /* - * Indicate to the HV that we are idle. Now would be - * a good time to find other work to dispatch. - */ - get_lppaca()->idle = 1; - - /* - * 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(); - - get_lppaca()->idle = 0; -} - static int pSeries_pci_probe_mode(struct pci_bus *bus) { if (firmware_has_feature(FW_FEATURE_LPAR)) diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index 7408af843b8a..23f81de51829 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -130,7 +130,6 @@ struct cpuidle_driver { #ifdef CONFIG_CPU_IDLE extern void disable_cpuidle(void); extern int cpuidle_idle_call(void); - extern int cpuidle_register_driver(struct cpuidle_driver *drv); struct cpuidle_driver *cpuidle_get_driver(void); extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); @@ -145,7 +144,6 @@ extern void cpuidle_disable_device(struct cpuidle_device *dev); #else static inline void disable_cpuidle(void) { } static inline int cpuidle_idle_call(void) { return -ENODEV; } - static inline int cpuidle_register_driver(struct cpuidle_driver *drv) {return -ENODEV; } static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }