vserver 1.9.3

[linux-2.6.git] / arch / um / kernel / time_kern.c

diff --git a/arch/um/kernel/time_kern.c b/arch/um/kernel/time_kern.c
index 752fd03..5ce5668 100644 (file)
--- 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(&regs);
 }
 
-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;i<n;i++) ;
 }
 
@@ -118,16 +163,18 @@ void __const_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;i<n;i++) ;
 }
 
 void timer_handler(int sig, union uml_pt_regs *regs)
 {
 #ifdef CONFIG_SMP
+       local_irq_disable();
        update_process_times(user_context(UPT_SP(regs)));
+       local_irq_enable();
 #endif
-       if(current->thread_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