diff options
Diffstat (limited to 'arch/arm/kernel/time.c')
| -rw-r--r-- | arch/arm/kernel/time.c | 497 |
1 files changed, 58 insertions, 439 deletions
diff --git a/arch/arm/kernel/time.c b/arch/arm/kernel/time.c index b5867eca1d0..829a96d4a17 100644 --- a/arch/arm/kernel/time.c +++ b/arch/arm/kernel/time.c @@ -10,43 +10,33 @@ * * This file contains the ARM-specific time handling details: * reading the RTC at bootup, etc... - * - * 1994-07-02 Alan Modra - * fixed set_rtc_mmss, fixed time.year for >= 2000, new mktime - * 1998-12-20 Updated NTP code according to technical memorandum Jan '96 - * "A Kernel Model for Precision Timekeeping" by Dave Mills */ -#include <linux/module.h> -#include <linux/kernel.h> -#include <linux/interrupt.h> -#include <linux/time.h> +#include <linux/clk-provider.h> +#include <linux/clocksource.h> +#include <linux/errno.h> +#include <linux/export.h> #include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/kernel.h> +#include <linux/profile.h> +#include <linux/sched.h> +#include <linux/sched_clock.h> #include <linux/smp.h> +#include <linux/time.h> #include <linux/timex.h> -#include <linux/errno.h> -#include <linux/profile.h> -#include <linux/sysdev.h> #include <linux/timer.h> -#include <linux/irq.h> -#include <linux/mc146818rtc.h> - -#include <asm/leds.h> -#include <asm/thread_info.h> +#include <asm/mach/arch.h> #include <asm/mach/time.h> +#include <asm/stacktrace.h> +#include <asm/thread_info.h> -/* - * Our system timer. - */ -struct sys_timer *system_timer; - -#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) +#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) || \ + defined(CONFIG_NVRAM) || defined(CONFIG_NVRAM_MODULE) /* this needs a better home */ DEFINE_SPINLOCK(rtc_lock); - -#ifdef CONFIG_RTC_DRV_CMOS_MODULE EXPORT_SYMBOL(rtc_lock); -#endif #endif /* pc-style 'CMOS' RTC support */ /* change this if you have some constant time drift */ @@ -55,266 +45,25 @@ EXPORT_SYMBOL(rtc_lock); #ifdef CONFIG_SMP unsigned long profile_pc(struct pt_regs *regs) { - unsigned long fp, pc = instruction_pointer(regs); - - if (in_lock_functions(pc)) { - fp = regs->ARM_fp; - pc = pc_pointer(((unsigned long *)fp)[-1]); - } - - return pc; -} -EXPORT_SYMBOL(profile_pc); -#endif - -/* - * hook for setting the RTC's idea of the current time. - */ -int (*set_rtc)(void); - -#ifndef CONFIG_GENERIC_TIME -static unsigned long dummy_gettimeoffset(void) -{ - return 0; -} -#endif - -static unsigned long next_rtc_update; - -/* - * If we have an externally synchronized linux clock, then update - * CMOS clock accordingly every ~11 minutes. set_rtc() has to be - * called as close as possible to 500 ms before the new second - * starts. - */ -static inline void do_set_rtc(void) -{ - if (!ntp_synced() || set_rtc == NULL) - return; - - if (next_rtc_update && - time_before((unsigned long)xtime.tv_sec, next_rtc_update)) - return; + struct stackframe frame; - if (xtime.tv_nsec < 500000000 - ((unsigned) tick_nsec >> 1) && - xtime.tv_nsec >= 500000000 + ((unsigned) tick_nsec >> 1)) - return; - - if (set_rtc()) - /* - * rtc update failed. Try again in 60s - */ - next_rtc_update = xtime.tv_sec + 60; - else - next_rtc_update = xtime.tv_sec + 660; -} - -#ifdef CONFIG_LEDS - -static void dummy_leds_event(led_event_t evt) -{ -} - -void (*leds_event)(led_event_t) = dummy_leds_event; - -struct leds_evt_name { - const char name[8]; - int on; - int off; -}; - -static const struct leds_evt_name evt_names[] = { - { "amber", led_amber_on, led_amber_off }, - { "blue", led_blue_on, led_blue_off }, - { "green", led_green_on, led_green_off }, - { "red", led_red_on, led_red_off }, -}; - -static ssize_t leds_store(struct sys_device *dev, const char *buf, size_t size) -{ - int ret = -EINVAL, len = strcspn(buf, " "); - - if (len > 0 && buf[len] == '\0') - len--; - - if (strncmp(buf, "claim", len) == 0) { - leds_event(led_claim); - ret = size; - } else if (strncmp(buf, "release", len) == 0) { - leds_event(led_release); - ret = size; - } else { - int i; - - for (i = 0; i < ARRAY_SIZE(evt_names); i++) { - if (strlen(evt_names[i].name) != len || - strncmp(buf, evt_names[i].name, len) != 0) - continue; - if (strncmp(buf+len, " on", 3) == 0) { - leds_event(evt_names[i].on); - ret = size; - } else if (strncmp(buf+len, " off", 4) == 0) { - leds_event(evt_names[i].off); - ret = size; - } - break; - } - } - return ret; -} - -static SYSDEV_ATTR(event, 0200, NULL, leds_store); - -static int leds_suspend(struct sys_device *dev, pm_message_t state) -{ - leds_event(led_stop); - return 0; -} - -static int leds_resume(struct sys_device *dev) -{ - leds_event(led_start); - return 0; -} - -static int leds_shutdown(struct sys_device *dev) -{ - leds_event(led_halted); - return 0; -} - -static struct sysdev_class leds_sysclass = { - .name = "leds", - .shutdown = leds_shutdown, - .suspend = leds_suspend, - .resume = leds_resume, -}; - -static struct sys_device leds_device = { - .id = 0, - .cls = &leds_sysclass, -}; - -static int __init leds_init(void) -{ - int ret; - ret = sysdev_class_register(&leds_sysclass); - if (ret == 0) - ret = sysdev_register(&leds_device); - if (ret == 0) - ret = sysdev_create_file(&leds_device, &attr_event); - return ret; -} - -device_initcall(leds_init); - -EXPORT_SYMBOL(leds_event); -#endif - -#ifdef CONFIG_LEDS_TIMER -static inline void do_leds(void) -{ - static unsigned int count = HZ/2; - - if (--count == 0) { - count = HZ/2; - leds_event(led_timer); - } -} -#else -#define do_leds() -#endif - -#ifndef CONFIG_GENERIC_TIME -void do_gettimeofday(struct timeval *tv) -{ - unsigned long flags; - unsigned long seq; - unsigned long usec, sec; + if (!in_lock_functions(regs->ARM_pc)) + return regs->ARM_pc; + frame.fp = regs->ARM_fp; + frame.sp = regs->ARM_sp; + frame.lr = regs->ARM_lr; + frame.pc = regs->ARM_pc; do { - seq = read_seqbegin_irqsave(&xtime_lock, flags); - usec = system_timer->offset(); - sec = xtime.tv_sec; - usec += xtime.tv_nsec / 1000; - } while (read_seqretry_irqrestore(&xtime_lock, seq, flags)); - - /* usec may have gone up a lot: be safe */ - while (usec >= 1000000) { - usec -= 1000000; - sec++; - } - - tv->tv_sec = sec; - tv->tv_usec = usec; -} - -EXPORT_SYMBOL(do_gettimeofday); - -int do_settimeofday(struct timespec *tv) -{ - time_t wtm_sec, sec = tv->tv_sec; - long wtm_nsec, nsec = tv->tv_nsec; - - if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) - return -EINVAL; - - write_seqlock_irq(&xtime_lock); - /* - * This is revolting. We need to set "xtime" correctly. However, the - * value in this location is the value at the most recent update of - * wall time. Discover what correction gettimeofday() would have - * done, and then undo it! - */ - nsec -= system_timer->offset() * NSEC_PER_USEC; - - wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec); - wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec); - - set_normalized_timespec(&xtime, sec, nsec); - set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec); + int ret = unwind_frame(&frame); + if (ret < 0) + return 0; + } while (in_lock_functions(frame.pc)); - ntp_clear(); - write_sequnlock_irq(&xtime_lock); - clock_was_set(); - return 0; + return frame.pc; } - -EXPORT_SYMBOL(do_settimeofday); -#endif /* !CONFIG_GENERIC_TIME */ - -/** - * save_time_delta - Save the offset between system time and RTC time - * @delta: pointer to timespec to store delta - * @rtc: pointer to timespec for current RTC time - * - * Return a delta between the system time and the RTC time, such - * that system time can be restored later with restore_time_delta() - */ -void save_time_delta(struct timespec *delta, struct timespec *rtc) -{ - set_normalized_timespec(delta, - xtime.tv_sec - rtc->tv_sec, - xtime.tv_nsec - rtc->tv_nsec); -} -EXPORT_SYMBOL(save_time_delta); - -/** - * restore_time_delta - Restore the current system time - * @delta: delta returned by save_time_delta() - * @rtc: pointer to timespec for current RTC time - */ -void restore_time_delta(struct timespec *delta, struct timespec *rtc) -{ - struct timespec ts; - - set_normalized_timespec(&ts, - delta->tv_sec + rtc->tv_sec, - delta->tv_nsec + rtc->tv_nsec); - - do_settimeofday(&ts); -} -EXPORT_SYMBOL(restore_time_delta); +EXPORT_SYMBOL(profile_pc); +#endif #ifndef CONFIG_GENERIC_CLOCKEVENTS /* @@ -323,187 +72,57 @@ EXPORT_SYMBOL(restore_time_delta); void timer_tick(void) { profile_tick(CPU_PROFILING); - do_leds(); - do_set_rtc(); - write_seqlock(&xtime_lock); - do_timer(1); - write_sequnlock(&xtime_lock); + xtime_update(1); #ifndef CONFIG_SMP update_process_times(user_mode(get_irq_regs())); #endif } #endif -#if defined(CONFIG_PM) && !defined(CONFIG_GENERIC_CLOCKEVENTS) -static int timer_suspend(struct sys_device *dev, pm_message_t state) -{ - struct sys_timer *timer = container_of(dev, struct sys_timer, dev); - - if (timer->suspend != NULL) - timer->suspend(); - - return 0; -} - -static int timer_resume(struct sys_device *dev) -{ - struct sys_timer *timer = container_of(dev, struct sys_timer, dev); - - if (timer->resume != NULL) - timer->resume(); - - return 0; -} -#else -#define timer_suspend NULL -#define timer_resume NULL -#endif - -static struct sysdev_class timer_sysclass = { - .name = "timer", - .suspend = timer_suspend, - .resume = timer_resume, -}; - -#ifdef CONFIG_NO_IDLE_HZ -static int timer_dyn_tick_enable(void) +static void dummy_clock_access(struct timespec *ts) { - struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick; - unsigned long flags; - int ret = -ENODEV; - - if (dyn_tick) { - spin_lock_irqsave(&dyn_tick->lock, flags); - ret = 0; - if (!(dyn_tick->state & DYN_TICK_ENABLED)) { - ret = dyn_tick->enable(); - - if (ret == 0) - dyn_tick->state |= DYN_TICK_ENABLED; - } - spin_unlock_irqrestore(&dyn_tick->lock, flags); - } - - return ret; + ts->tv_sec = 0; + ts->tv_nsec = 0; } -static int timer_dyn_tick_disable(void) -{ - struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick; - unsigned long flags; - int ret = -ENODEV; - - if (dyn_tick) { - spin_lock_irqsave(&dyn_tick->lock, flags); - ret = 0; - if (dyn_tick->state & DYN_TICK_ENABLED) { - ret = dyn_tick->disable(); - - if (ret == 0) - dyn_tick->state &= ~DYN_TICK_ENABLED; - } - spin_unlock_irqrestore(&dyn_tick->lock, flags); - } - - return ret; -} +static clock_access_fn __read_persistent_clock = dummy_clock_access; +static clock_access_fn __read_boot_clock = dummy_clock_access;; -/* - * Reprogram the system timer for at least the calculated time interval. - * This function should be called from the idle thread with IRQs disabled, - * immediately before sleeping. - */ -void timer_dyn_reprogram(void) +void read_persistent_clock(struct timespec *ts) { - struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick; - unsigned long next, seq, flags; - - if (!dyn_tick) - return; - - spin_lock_irqsave(&dyn_tick->lock, flags); - if (dyn_tick->state & DYN_TICK_ENABLED) { - next = next_timer_interrupt(); - do { - seq = read_seqbegin(&xtime_lock); - dyn_tick->reprogram(next - jiffies); - } while (read_seqretry(&xtime_lock, seq)); - } - spin_unlock_irqrestore(&dyn_tick->lock, flags); + __read_persistent_clock(ts); } -static ssize_t timer_show_dyn_tick(struct sys_device *dev, char *buf) +void read_boot_clock(struct timespec *ts) { - return sprintf(buf, "%i\n", - (system_timer->dyn_tick->state & DYN_TICK_ENABLED) >> 1); + __read_boot_clock(ts); } -static ssize_t timer_set_dyn_tick(struct sys_device *dev, const char *buf, - size_t count) +int __init register_persistent_clock(clock_access_fn read_boot, + clock_access_fn read_persistent) { - unsigned int enable = simple_strtoul(buf, NULL, 2); - - if (enable) - timer_dyn_tick_enable(); - else - timer_dyn_tick_disable(); - - return count; -} -static SYSDEV_ATTR(dyn_tick, 0644, timer_show_dyn_tick, timer_set_dyn_tick); + /* Only allow the clockaccess functions to be registered once */ + if (__read_persistent_clock == dummy_clock_access && + __read_boot_clock == dummy_clock_access) { + if (read_boot) + __read_boot_clock = read_boot; + if (read_persistent) + __read_persistent_clock = read_persistent; -/* - * dyntick=enable|disable - */ -static char dyntick_str[4] __initdata = ""; - -static int __init dyntick_setup(char *str) -{ - if (str) - strlcpy(dyntick_str, str, sizeof(dyntick_str)); - return 1; -} - -__setup("dyntick=", dyntick_setup); -#endif - -static int __init timer_init_sysfs(void) -{ - int ret = sysdev_class_register(&timer_sysclass); - if (ret == 0) { - system_timer->dev.cls = &timer_sysclass; - ret = sysdev_register(&system_timer->dev); + return 0; } -#ifdef CONFIG_NO_IDLE_HZ - if (ret == 0 && system_timer->dyn_tick) { - ret = sysdev_create_file(&system_timer->dev, &attr_dyn_tick); - - /* - * Turn on dynamic tick after calibrate delay - * for correct bogomips - */ - if (ret == 0 && dyntick_str[0] == 'e') - ret = timer_dyn_tick_enable(); - } -#endif - - return ret; + return -EINVAL; } -device_initcall(timer_init_sysfs); - void __init time_init(void) { -#ifndef CONFIG_GENERIC_TIME - if (system_timer->offset == NULL) - system_timer->offset = dummy_gettimeoffset; -#endif - system_timer->init(); - -#ifdef CONFIG_NO_IDLE_HZ - if (system_timer->dyn_tick) - spin_lock_init(&system_timer->dyn_tick->lock); + if (machine_desc->init_time) { + machine_desc->init_time(); + } else { +#ifdef CONFIG_COMMON_CLK + of_clk_init(NULL); #endif + clocksource_of_init(); + } } - |