X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fum%2Fkernel%2Ftime_kern.c;h=5ce5668825fc750c4d234c6e67fae3e6f1ddb3fd;hb=c7b5ebbddf7bcd3651947760f423e3783bbe6573;hp=752fd03f2bcd666eb7f4fc7f22951187f4b9f454;hpb=a2c21200f1c81b08cb55e417b68150bba439b646;p=linux-2.6.git diff --git a/arch/um/kernel/time_kern.c b/arch/um/kernel/time_kern.c index 752fd03f2..5ce566882 100644 --- a/arch/um/kernel/time_kern.c +++ b/arch/um/kernel/time_kern.c @@ -20,6 +20,7 @@ #include "user_util.h" #include "time_user.h" #include "mode.h" +#include "os.h" u64 jiffies_64; @@ -30,22 +31,63 @@ 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; -/* missed_ticks will be modified after kernel memory has been - * write-protected, so this puts it in a section which will be left - * write-enabled. - */ -int __attribute__ ((__section__ (".unprotected"))) missed_ticks[NR_CPUS]; +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) { - int cpu = current->thread_info->cpu, ticks = missed_ticks[cpu]; + 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(); - if(!timer_irq_inited) return; - missed_ticks[cpu] = 0; - while(ticks--) do_IRQ(TIMER_IRQ, regs); + 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) @@ -58,12 +100,15 @@ void boot_timer_handler(int sig) do_timer(®s); } -void um_timer(int irq, void *dev, struct pt_regs *regs) +irqreturn_t um_timer(int irq, void *dev, struct pt_regs *regs) { + unsigned long flags; + do_timer(regs); - write_seqlock(&xtime_lock); + write_seqlock_irqsave(&xtime_lock, flags); timer(); - write_sequnlock(&xtime_lock); + write_sequnlock_irqrestore(&xtime_lock, flags); + return(IRQ_HANDLED); } long um_time(int * tloc) @@ -81,12 +126,12 @@ long um_time(int * tloc) long um_stime(int * tptr) { int value; - struct timeval new; + struct timespec new; if (get_user(value, tptr)) return -EFAULT; new.tv_sec = value; - new.tv_usec = 0; + new.tv_nsec = 0; do_settimeofday(&new); return 0; } @@ -110,7 +155,7 @@ void __udelay(um_udelay_t usecs) { int i, n; - n = (loops_per_jiffy * HZ * usecs) / 1000000; + n = (loops_per_jiffy * HZ * usecs) / MILLION; for(i=0;ithread_info->cpu == 0) + if(current_thread->cpu == 0) timer_irq(regs); } @@ -136,6 +183,7 @@ static spinlock_t timer_spinlock = SPIN_LOCK_UNLOCKED; unsigned long time_lock(void) { unsigned long flags; + spin_lock_irqsave(&timer_spinlock, flags); return(flags); } @@ -150,8 +198,8 @@ int __init timer_init(void) int err; CHOOSE_MODE(user_time_init_tt(), user_time_init_skas()); - if((err = request_irq(TIMER_IRQ, um_timer, SA_INTERRUPT, "timer", - NULL)) != 0) + 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; @@ -160,7 +208,6 @@ int __init timer_init(void) __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