arch/um/kernel/time_kern.c

   1 /*
   2  * Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include "linux/kernel.h"
   7 #include "linux/unistd.h"
   8 #include "linux/stddef.h"
   9 #include "linux/spinlock.h"
  10 #include "linux/time.h"
  11 #include "linux/sched.h"
  12 #include "linux/interrupt.h"
  13 #include "linux/init.h"
  14 #include "linux/delay.h"
  15 #include "asm/irq.h"
  16 #include "asm/param.h"
  17 #include "asm/current.h"
  18 #include "kern_util.h"
  19 #include "user_util.h"
  20 #include "time_user.h"
  21 #include "mode.h"
  22
  23 u64 jiffies_64;
  24
  25 int hz(void)
  26 {
  27         return(HZ);
  28 }
  29
  30 /* Changed at early boot */
  31 int timer_irq_inited = 0;
  32
  33 /* missed_ticks will be modified after kernel memory has been
  34  * write-protected, so this puts it in a section which will be left
  35  * write-enabled.
  36  */
  37 int __attribute__ ((__section__ (".unprotected"))) missed_ticks[NR_CPUS];
  38
  39 void timer_irq(union uml_pt_regs *regs)
  40 {
  41         int cpu = current->thread_info->cpu, ticks = missed_ticks[cpu];
  42
  43         if(!timer_irq_inited) return;
  44         missed_ticks[cpu] = 0;
  45         while(ticks--) do_IRQ(TIMER_IRQ, regs);
  46 }
  47
  48 void boot_timer_handler(int sig)
  49 {
  50         struct pt_regs regs;
  51
  52         CHOOSE_MODE((void)
  53                     (UPT_SC(&regs.regs) = (struct sigcontext *) (&sig + 1)),
  54                     (void) (regs.regs.skas.is_user = 0));
  55         do_timer(&regs);
  56 }
  57
  58 void um_timer(int irq, void *dev, struct pt_regs *regs)
  59 {
  60         do_timer(regs);
  61         write_seqlock(&xtime_lock);
  62         timer();
  63         write_sequnlock(&xtime_lock);
  64 }
  65
  66 long um_time(int * tloc)
  67 {
  68         struct timeval now;
  69
  70         do_gettimeofday(&now);
  71         if (tloc) {
  72                 if (put_user(now.tv_sec,tloc))
  73                         now.tv_sec = -EFAULT;
  74         }
  75         return now.tv_sec;
  76 }
  77
  78 long um_stime(int * tptr)
  79 {
  80         int value;
  81         struct timeval new;
  82
  83         if (get_user(value, tptr))
  84                 return -EFAULT;
  85         new.tv_sec = value;
  86         new.tv_usec = 0;
  87         do_settimeofday(&new);
  88         return 0;
  89 }
  90
  91 /* XXX Needs to be moved under sys-i386 */
  92 void __delay(um_udelay_t time)
  93 {
  94         /* Stolen from the i386 __loop_delay */
  95         int d0;
  96         __asm__ __volatile__(
  97                 "\tjmp 1f\n"
  98                 ".align 16\n"
  99                 "1:\tjmp 2f\n"
 100                 ".align 16\n"
 101                 "2:\tdecl %0\n\tjns 2b"
 102                 :"=&a" (d0)
 103                 :"0" (time));
 104 }
 105
 106 void __udelay(um_udelay_t usecs)
 107 {
 108         int i, n;
 109
 110         n = (loops_per_jiffy * HZ * usecs) / 1000000;
 111         for(i=0;i<n;i++) ;
 112 }
 113
 114 void __const_udelay(um_udelay_t usecs)
 115 {
 116         int i, n;
 117
 118         n = (loops_per_jiffy * HZ * usecs) / 1000000;
 119         for(i=0;i<n;i++) ;
 120 }
 121
 122 void timer_handler(int sig, union uml_pt_regs *regs)
 123 {
 124 #ifdef CONFIG_SMP
 125         update_process_times(user_context(UPT_SP(regs)));
 126 #endif
 127         if(current->thread_info->cpu == 0)
 128                 timer_irq(regs);
 129 }
 130
 131 static spinlock_t timer_spinlock = SPIN_LOCK_UNLOCKED;
 132
 133 unsigned long time_lock(void)
 134 {
 135         unsigned long flags;
 136         spin_lock_irqsave(&timer_spinlock, flags);
 137         return(flags);
 138 }
 139
 140 void time_unlock(unsigned long flags)
 141 {
 142         spin_unlock_irqrestore(&timer_spinlock, flags);
 143 }
 144
 145 int __init timer_init(void)
 146 {
 147         int err;
 148
 149         CHOOSE_MODE(user_time_init_tt(), user_time_init_skas());
 150         if((err = request_irq(TIMER_IRQ, um_timer, SA_INTERRUPT, "timer",
 151                               NULL)) != 0)
 152                 printk(KERN_ERR "timer_init : request_irq failed - "
 153                        "errno = %d\n", -err);
 154         timer_irq_inited = 1;
 155         return(0);
 156 }
 157
 158 __initcall(timer_init);
 159
 160
 161 /*
 162  * Overrides for Emacs so that we follow Linus's tabbing style.
 163  * Emacs will notice this stuff at the end of the file and automatically
 164  * adjust the settings for this buffer only.  This must remain at the end
 165  * of the file.
 166  * ---------------------------------------------------------------------------
 167  * Local variables:
 168  * c-file-style: "linux"
 169  * End:
 170  */