2 * Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
3 * Licensed under the GPL
6 #include "linux/kernel.h"
7 #include "linux/module.h"
8 #include "linux/unistd.h"
9 #include "linux/stddef.h"
10 #include "linux/spinlock.h"
11 #include "linux/time.h"
12 #include "linux/sched.h"
13 #include "linux/interrupt.h"
14 #include "linux/init.h"
15 #include "linux/delay.h"
17 #include "asm/param.h"
18 #include "asm/current.h"
19 #include "kern_util.h"
20 #include "user_util.h"
21 #include "time_user.h"
26 EXPORT_SYMBOL(jiffies_64);
34 * Scheduler clock - returns current time in nanosec units.
36 unsigned long long sched_clock(void)
38 return (unsigned long long)jiffies_64 * (1000000000 / HZ);
41 /* Changed at early boot */
42 int timer_irq_inited = 0;
44 static int first_tick;
45 static unsigned long long prev_tsc;
46 static long long delta; /* Deviation per interval */
48 extern unsigned long long host_hz;
50 void timer_irq(union uml_pt_regs *regs)
52 unsigned long long ticks = 0;
54 if(!timer_irq_inited){
55 /* This is to ensure that ticks don't pile up when
56 * the timer handler is suspended */
62 #if defined(CONFIG_UML_REAL_TIME_CLOCK)
63 unsigned long long tsc;
64 /* We've had 1 tick */
67 delta += tsc - prev_tsc;
70 ticks += (delta * HZ) / host_hz;
71 delta -= (ticks * host_hz) / HZ;
77 prev_tsc = time_stamp();
82 do_IRQ(TIMER_IRQ, regs);
87 void boot_timer_handler(int sig)
92 (UPT_SC(®s.regs) = (struct sigcontext *) (&sig + 1)),
93 (void) (regs.regs.skas.is_user = 0));
97 irqreturn_t um_timer(int irq, void *dev, struct pt_regs *regs)
102 write_seqlock_irqsave(&xtime_lock, flags);
104 write_sequnlock_irqrestore(&xtime_lock, flags);
108 long um_time(int * tloc)
112 do_gettimeofday(&now);
114 if (put_user(now.tv_sec,tloc))
115 now.tv_sec = -EFAULT;
120 long um_stime(int * tptr)
125 if (get_user(value, tptr))
129 do_settimeofday(&new);
133 /* XXX Needs to be moved under sys-i386 */
134 void __delay(um_udelay_t time)
136 /* Stolen from the i386 __loop_delay */
138 __asm__ __volatile__(
143 "2:\tdecl %0\n\tjns 2b"
148 void __udelay(um_udelay_t usecs)
152 n = (loops_per_jiffy * HZ * usecs) / 1000000;
156 void __const_udelay(um_udelay_t usecs)
160 n = (loops_per_jiffy * HZ * usecs) / 1000000;
164 void timer_handler(int sig, union uml_pt_regs *regs)
168 update_process_times(user_context(UPT_SP(regs)));
171 if(current_thread->cpu == 0)
175 static spinlock_t timer_spinlock = SPIN_LOCK_UNLOCKED;
177 unsigned long time_lock(void)
181 spin_lock_irqsave(&timer_spinlock, flags);
185 void time_unlock(unsigned long flags)
187 spin_unlock_irqrestore(&timer_spinlock, flags);
190 int __init timer_init(void)
194 CHOOSE_MODE(user_time_init_tt(), user_time_init_skas());
195 err = request_irq(TIMER_IRQ, um_timer, SA_INTERRUPT, "timer", NULL);
197 printk(KERN_ERR "timer_init : request_irq failed - "
198 "errno = %d\n", -err);
199 timer_irq_inited = 1;
203 __initcall(timer_init);
206 * Overrides for Emacs so that we follow Linus's tabbing style.
207 * Emacs will notice this stuff at the end of the file and automatically
208 * adjust the settings for this buffer only. This must remain at the end
210 * ---------------------------------------------------------------------------
212 * c-file-style: "linux"