diff options
Diffstat (limited to 'arch/um/kernel/time_kern.c')
| -rw-r--r-- | arch/um/kernel/time_kern.c | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/arch/um/kernel/time_kern.c b/arch/um/kernel/time_kern.c new file mode 100644 index 000000000000..2461cd73ca87 --- /dev/null +++ b/arch/um/kernel/time_kern.c @@ -0,0 +1,203 @@ +/* + * Copyright (C) 2000 Jeff Dike (jdike@karaya.com) + * Licensed under the GPL + */ + +#include "linux/kernel.h" +#include "linux/module.h" +#include "linux/unistd.h" +#include "linux/stddef.h" +#include "linux/spinlock.h" +#include "linux/time.h" +#include "linux/sched.h" +#include "linux/interrupt.h" +#include "linux/init.h" +#include "linux/delay.h" +#include "asm/irq.h" +#include "asm/param.h" +#include "asm/current.h" +#include "kern_util.h" +#include "user_util.h" +#include "time_user.h" +#include "mode.h" +#include "os.h" + +u64 jiffies_64 = INITIAL_JIFFIES; + +EXPORT_SYMBOL(jiffies_64); + +int hz(void) +{ + return(HZ); +} + +/* + * Scheduler clock - returns current time in nanosec units. + */ +unsigned long long sched_clock(void) +{ + return (unsigned long long)jiffies_64 * (1000000000 / HZ); +} + +/* Changed at early boot */ +int timer_irq_inited = 0; + +static int first_tick; +static unsigned long long prev_usecs; +#ifdef CONFIG_UML_REAL_TIME_CLOCK +static long long delta; /* Deviation per interval */ +#endif + +#define MILLION 1000000 + +void timer_irq(union uml_pt_regs *regs) +{ + unsigned long long ticks = 0; + + if(!timer_irq_inited){ + /* This is to ensure that ticks don't pile up when + * the timer handler is suspended */ + first_tick = 0; + return; + } + + if(first_tick){ +#ifdef CONFIG_UML_REAL_TIME_CLOCK + /* We've had 1 tick */ + unsigned long long usecs = os_usecs(); + + delta += usecs - prev_usecs; + prev_usecs = usecs; + + /* Protect against the host clock being set backwards */ + if(delta < 0) + delta = 0; + + ticks += (delta * HZ) / MILLION; + delta -= (ticks * MILLION) / HZ; +#else + ticks = 1; +#endif + } + else { + prev_usecs = os_usecs(); + first_tick = 1; + } + + while(ticks > 0){ + do_IRQ(TIMER_IRQ, regs); + ticks--; + } +} + +void boot_timer_handler(int sig) +{ + struct pt_regs regs; + + CHOOSE_MODE((void) + (UPT_SC(®s.regs) = (struct sigcontext *) (&sig + 1)), + (void) (regs.regs.skas.is_user = 0)); + do_timer(®s); +} + +irqreturn_t um_timer(int irq, void *dev, struct pt_regs *regs) +{ + unsigned long flags; + + do_timer(regs); + write_seqlock_irqsave(&xtime_lock, flags); + timer(); + write_sequnlock_irqrestore(&xtime_lock, flags); + return(IRQ_HANDLED); +} + +long um_time(int __user *tloc) +{ + struct timeval now; + + do_gettimeofday(&now); + if (tloc) { + if (put_user(now.tv_sec, tloc)) + now.tv_sec = -EFAULT; + } + return now.tv_sec; +} + +long um_stime(int __user *tptr) +{ + int value; + struct timespec new; + + if (get_user(value, tptr)) + return -EFAULT; + new.tv_sec = value; + new.tv_nsec = 0; + do_settimeofday(&new); + return 0; +} + +void __udelay(unsigned long usecs) +{ + int i, n; + + n = (loops_per_jiffy * HZ * usecs) / MILLION; + for(i=0;i<n;i++) ; +} + +void __const_udelay(unsigned long usecs) +{ + int i, n; + + n = (loops_per_jiffy * HZ * usecs) / MILLION; + for(i=0;i<n;i++) ; +} + +void timer_handler(int sig, union uml_pt_regs *regs) +{ + local_irq_disable(); + update_process_times(CHOOSE_MODE(user_context(UPT_SP(regs)), (regs)->skas.is_user)); + local_irq_enable(); + if(current_thread->cpu == 0) + timer_irq(regs); +} + +static DEFINE_SPINLOCK(timer_spinlock); + +unsigned long time_lock(void) +{ + unsigned long flags; + + spin_lock_irqsave(&timer_spinlock, flags); + return(flags); +} + +void time_unlock(unsigned long flags) +{ + spin_unlock_irqrestore(&timer_spinlock, flags); +} + +int __init timer_init(void) +{ + int err; + + CHOOSE_MODE(user_time_init_tt(), user_time_init_skas()); + err = request_irq(TIMER_IRQ, um_timer, SA_INTERRUPT, "timer", NULL); + if(err != 0) + printk(KERN_ERR "timer_init : request_irq failed - " + "errno = %d\n", -err); + timer_irq_inited = 1; + return(0); +} + +__initcall(timer_init); + +/* + * Overrides for Emacs so that we follow Linus's tabbing style. + * Emacs will notice this stuff at the end of the file and automatically + * adjust the settings for this buffer only. This must remain at the end + * of the file. + * --------------------------------------------------------------------------- + * Local variables: + * c-file-style: "linux" + * End: + */ |