xref: /openbmc/linux/arch/sparc/kernel/vdso.c (revision d9fd5a71)
1 /*
2  *  Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE
3  *  Copyright 2003 Andi Kleen, SuSE Labs.
4  *
5  *  Thanks to hpa@transmeta.com for some useful hint.
6  *  Special thanks to Ingo Molnar for his early experience with
7  *  a different vsyscall implementation for Linux/IA32 and for the name.
8  */
9 
10 #include <linux/time.h>
11 #include <linux/timekeeper_internal.h>
12 
13 #include <asm/vvar.h>
14 
15 void update_vsyscall_tz(void)
16 {
17 	if (unlikely(vvar_data == NULL))
18 		return;
19 
20 	vvar_data->tz_minuteswest = sys_tz.tz_minuteswest;
21 	vvar_data->tz_dsttime = sys_tz.tz_dsttime;
22 }
23 
24 void update_vsyscall(struct timekeeper *tk)
25 {
26 	struct vvar_data *vdata = vvar_data;
27 
28 	if (unlikely(vdata == NULL))
29 		return;
30 
31 	vvar_write_begin(vdata);
32 	vdata->vclock_mode = tk->tkr_mono.clock->archdata.vclock_mode;
33 	vdata->clock.cycle_last = tk->tkr_mono.cycle_last;
34 	vdata->clock.mask = tk->tkr_mono.mask;
35 	vdata->clock.mult = tk->tkr_mono.mult;
36 	vdata->clock.shift = tk->tkr_mono.shift;
37 
38 	vdata->wall_time_sec = tk->xtime_sec;
39 	vdata->wall_time_snsec = tk->tkr_mono.xtime_nsec;
40 
41 	vdata->monotonic_time_sec = tk->xtime_sec +
42 				    tk->wall_to_monotonic.tv_sec;
43 	vdata->monotonic_time_snsec = tk->tkr_mono.xtime_nsec +
44 				      (tk->wall_to_monotonic.tv_nsec <<
45 				       tk->tkr_mono.shift);
46 
47 	while (vdata->monotonic_time_snsec >=
48 	       (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) {
49 		vdata->monotonic_time_snsec -=
50 				((u64)NSEC_PER_SEC) << tk->tkr_mono.shift;
51 		vdata->monotonic_time_sec++;
52 	}
53 
54 	vdata->wall_time_coarse_sec = tk->xtime_sec;
55 	vdata->wall_time_coarse_nsec =
56 			(long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
57 
58 	vdata->monotonic_time_coarse_sec =
59 		vdata->wall_time_coarse_sec + tk->wall_to_monotonic.tv_sec;
60 	vdata->monotonic_time_coarse_nsec =
61 		vdata->wall_time_coarse_nsec + tk->wall_to_monotonic.tv_nsec;
62 
63 	while (vdata->monotonic_time_coarse_nsec >= NSEC_PER_SEC) {
64 		vdata->monotonic_time_coarse_nsec -= NSEC_PER_SEC;
65 		vdata->monotonic_time_coarse_sec++;
66 	}
67 
68 	vvar_write_end(vdata);
69 }
70