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192.168.1.100 / T108 / e958203796650e3959a43708d67534bf36f4c83b / . / marvell / linux / kernel / time / vsyscall.c
blob: 9577c89179cd1309b99d8224bc21a6622407d210 [file] [log] [blame]
b.liue9582032025-04-17 19:18:16 +0800[diff] [blame^]1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright 2019 ARM Ltd.
4 *
5 * Generic implementation of update_vsyscall and update_vsyscall_tz.
6 *
7 * Based on the x86 specific implementation.
8 */
9
10#include <linux/hrtimer.h>
11#include <linux/timekeeper_internal.h>
12#include <vdso/datapage.h>
13#include <vdso/helpers.h>
14#include <vdso/vsyscall.h>
15
16static inline void update_vdso_data(struct vdso_data *vdata,
17 struct timekeeper *tk)
18{
19 struct vdso_timestamp *vdso_ts;
20 u64 nsec, sec;
21
22 vdata[CS_HRES_COARSE].cycle_last = tk->tkr_mono.cycle_last;
23 vdata[CS_HRES_COARSE].mask = tk->tkr_mono.mask;
24 vdata[CS_HRES_COARSE].mult = tk->tkr_mono.mult;
25 vdata[CS_HRES_COARSE].shift = tk->tkr_mono.shift;
26 vdata[CS_RAW].cycle_last = tk->tkr_raw.cycle_last;
27 vdata[CS_RAW].mask = tk->tkr_raw.mask;
28 vdata[CS_RAW].mult = tk->tkr_raw.mult;
29 vdata[CS_RAW].shift = tk->tkr_raw.shift;
30
31 /* CLOCK_MONOTONIC */
32 vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_MONOTONIC];
33 vdso_ts->sec = tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
34
35 nsec = tk->tkr_mono.xtime_nsec;
36 nsec += ((u64)tk->wall_to_monotonic.tv_nsec << tk->tkr_mono.shift);
37 while (nsec >= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) {
38 nsec -= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift);
39 vdso_ts->sec++;
40 }
41 vdso_ts->nsec = nsec;
42
43 /* Copy MONOTONIC time for BOOTTIME */
44 sec = vdso_ts->sec;
45 /* Add the boot offset */
46 sec += tk->monotonic_to_boot.tv_sec;
47 nsec += (u64)tk->monotonic_to_boot.tv_nsec << tk->tkr_mono.shift;
48
49 /* CLOCK_BOOTTIME */
50 vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_BOOTTIME];
51 vdso_ts->sec = sec;
52
53 while (nsec >= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) {
54 nsec -= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift);
55 vdso_ts->sec++;
56 }
57 vdso_ts->nsec = nsec;
58
59 /* CLOCK_MONOTONIC_RAW */
60 vdso_ts = &vdata[CS_RAW].basetime[CLOCK_MONOTONIC_RAW];
61 vdso_ts->sec = tk->raw_sec;
62 vdso_ts->nsec = tk->tkr_raw.xtime_nsec;
63
64 /* CLOCK_TAI */
65 vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_TAI];
66 vdso_ts->sec = tk->xtime_sec + (s64)tk->tai_offset;
67 vdso_ts->nsec = tk->tkr_mono.xtime_nsec;
68}
69
70void update_vsyscall(struct timekeeper *tk)
71{
72 struct vdso_data *vdata = __arch_get_k_vdso_data();
73 struct vdso_timestamp *vdso_ts;
74 u64 nsec;
75
76 /* copy vsyscall data */
77 vdso_write_begin(vdata);
78
79 vdata[CS_HRES_COARSE].clock_mode = __arch_get_clock_mode(tk);
80 vdata[CS_RAW].clock_mode = __arch_get_clock_mode(tk);
81
82 /* CLOCK_REALTIME also required for time() */
83 vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_REALTIME];
84 vdso_ts->sec = tk->xtime_sec;
85 vdso_ts->nsec = tk->tkr_mono.xtime_nsec;
86
87 /* CLOCK_REALTIME_COARSE */
88 vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_REALTIME_COARSE];
89 vdso_ts->sec = tk->xtime_sec;
90 vdso_ts->nsec = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift;
91
92 /* CLOCK_MONOTONIC_COARSE */
93 vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_MONOTONIC_COARSE];
94 vdso_ts->sec = tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
95 nsec = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift;
96 nsec = nsec + tk->wall_to_monotonic.tv_nsec;
97 vdso_ts->sec += __iter_div_u64_rem(nsec, NSEC_PER_SEC, &vdso_ts->nsec);
98
99 /*
100 * Read without the seqlock held by clock_getres().
101 * Note: No need to have a second copy.
102 */
103 WRITE_ONCE(vdata[CS_HRES_COARSE].hrtimer_res, hrtimer_resolution);
104
105 /*
106 * Architectures can opt out of updating the high resolution part
107 * of the VDSO.
108 */
109 if (__arch_update_vdso_data())
110 update_vdso_data(vdata, tk);
111
112 __arch_update_vsyscall(vdata, tk);
113
114 vdso_write_end(vdata);
115
116 __arch_sync_vdso_data(vdata);
117}
118
119void update_vsyscall_tz(void)
120{
121 struct vdso_data *vdata = __arch_get_k_vdso_data();
122
123 vdata[CS_HRES_COARSE].tz_minuteswest = sys_tz.tz_minuteswest;
124 vdata[CS_HRES_COARSE].tz_dsttime = sys_tz.tz_dsttime;
125
126 __arch_sync_vdso_data(vdata);
127}