]>
git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/blob - kernel/time/vsyscall.c
8cf3596a4ce677ca787e214d6f33b32a6d6b4088
1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright 2019 ARM Ltd.
5 * Generic implementation of update_vsyscall and update_vsyscall_tz.
7 * Based on the x86 specific implementation.
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>
16 static inline void update_vdso_data(struct vdso_data
*vdata
,
17 struct timekeeper
*tk
)
19 struct vdso_timestamp
*vdso_ts
;
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
;
32 vdso_ts
= &vdata
[CS_HRES_COARSE
].basetime
[CLOCK_REALTIME
];
33 vdso_ts
->sec
= tk
->xtime_sec
;
34 vdso_ts
->nsec
= tk
->tkr_mono
.xtime_nsec
;
37 vdso_ts
= &vdata
[CS_HRES_COARSE
].basetime
[CLOCK_MONOTONIC
];
38 vdso_ts
->sec
= tk
->xtime_sec
+ tk
->wall_to_monotonic
.tv_sec
;
40 nsec
= tk
->tkr_mono
.xtime_nsec
;
41 nsec
+= ((u64
)tk
->wall_to_monotonic
.tv_nsec
<< tk
->tkr_mono
.shift
);
42 while (nsec
>= (((u64
)NSEC_PER_SEC
) << tk
->tkr_mono
.shift
)) {
43 nsec
-= (((u64
)NSEC_PER_SEC
) << tk
->tkr_mono
.shift
);
48 /* CLOCK_MONOTONIC_RAW */
49 vdso_ts
= &vdata
[CS_RAW
].basetime
[CLOCK_MONOTONIC_RAW
];
50 vdso_ts
->sec
= tk
->raw_sec
;
51 vdso_ts
->nsec
= tk
->tkr_raw
.xtime_nsec
;
54 vdso_ts
= &vdata
[CS_HRES_COARSE
].basetime
[CLOCK_BOOTTIME
];
55 vdso_ts
->sec
= tk
->xtime_sec
+ tk
->wall_to_monotonic
.tv_sec
;
56 nsec
= tk
->tkr_mono
.xtime_nsec
;
57 nsec
+= ((u64
)(tk
->wall_to_monotonic
.tv_nsec
+
58 ktime_to_ns(tk
->offs_boot
)) << tk
->tkr_mono
.shift
);
59 while (nsec
>= (((u64
)NSEC_PER_SEC
) << tk
->tkr_mono
.shift
)) {
60 nsec
-= (((u64
)NSEC_PER_SEC
) << tk
->tkr_mono
.shift
);
66 vdso_ts
= &vdata
[CS_HRES_COARSE
].basetime
[CLOCK_TAI
];
67 vdso_ts
->sec
= tk
->xtime_sec
+ (s64
)tk
->tai_offset
;
68 vdso_ts
->nsec
= tk
->tkr_mono
.xtime_nsec
;
71 * Read without the seqlock held by clock_getres().
72 * Note: No need to have a second copy.
74 WRITE_ONCE(vdata
[CS_HRES_COARSE
].hrtimer_res
, hrtimer_resolution
);
77 void update_vsyscall(struct timekeeper
*tk
)
79 struct vdso_data
*vdata
= __arch_get_k_vdso_data();
80 struct vdso_timestamp
*vdso_ts
;
83 if (__arch_update_vdso_data()) {
85 * Some architectures might want to skip the update of the
91 /* copy vsyscall data */
92 vdso_write_begin(vdata
);
94 vdata
[CS_HRES_COARSE
].clock_mode
= __arch_get_clock_mode(tk
);
95 vdata
[CS_RAW
].clock_mode
= __arch_get_clock_mode(tk
);
97 /* CLOCK_REALTIME_COARSE */
98 vdso_ts
= &vdata
[CS_HRES_COARSE
].basetime
[CLOCK_REALTIME_COARSE
];
99 vdso_ts
->sec
= tk
->xtime_sec
;
100 vdso_ts
->nsec
= tk
->tkr_mono
.xtime_nsec
>> tk
->tkr_mono
.shift
;
102 /* CLOCK_MONOTONIC_COARSE */
103 vdso_ts
= &vdata
[CS_HRES_COARSE
].basetime
[CLOCK_MONOTONIC_COARSE
];
104 vdso_ts
->sec
= tk
->xtime_sec
+ tk
->wall_to_monotonic
.tv_sec
;
105 nsec
= tk
->tkr_mono
.xtime_nsec
>> tk
->tkr_mono
.shift
;
106 nsec
= nsec
+ tk
->wall_to_monotonic
.tv_nsec
;
107 vdso_ts
->sec
+= __iter_div_u64_rem(nsec
, NSEC_PER_SEC
, &vdso_ts
->nsec
);
109 if (__arch_use_vsyscall(vdata
))
110 update_vdso_data(vdata
, tk
);
112 __arch_update_vsyscall(vdata
, tk
);
114 vdso_write_end(vdata
);
116 __arch_sync_vdso_data(vdata
);
119 void update_vsyscall_tz(void)
121 struct vdso_data
*vdata
= __arch_get_k_vdso_data();
123 if (__arch_use_vsyscall(vdata
)) {
124 vdata
[CS_HRES_COARSE
].tz_minuteswest
= sys_tz
.tz_minuteswest
;
125 vdata
[CS_HRES_COARSE
].tz_dsttime
= sys_tz
.tz_dsttime
;
128 __arch_sync_vdso_data(vdata
);