1 // SPDX-License-Identifier: GPL-2.0 1 // SPDX-License-Identifier: GPL-2.0
2 /* 2 /*
3 * Copyright 2019 ARM Ltd. 3 * Copyright 2019 ARM Ltd.
4 * 4 *
5 * Generic implementation of update_vsyscall a 5 * Generic implementation of update_vsyscall and update_vsyscall_tz.
6 * 6 *
7 * Based on the x86 specific implementation. 7 * Based on the x86 specific implementation.
8 */ 8 */
9 9
10 #include <linux/hrtimer.h> 10 #include <linux/hrtimer.h>
11 #include <linux/timekeeper_internal.h> 11 #include <linux/timekeeper_internal.h>
12 #include <vdso/datapage.h> 12 #include <vdso/datapage.h>
13 #include <vdso/helpers.h> 13 #include <vdso/helpers.h>
14 #include <vdso/vsyscall.h> 14 #include <vdso/vsyscall.h>
15 15
16 #include "timekeeping_internal.h" <<
17 <<
18 static inline void update_vdso_data(struct vds 16 static inline void update_vdso_data(struct vdso_data *vdata,
19 struct tim 17 struct timekeeper *tk)
20 { 18 {
21 struct vdso_timestamp *vdso_ts; 19 struct vdso_timestamp *vdso_ts;
22 u64 nsec, sec; 20 u64 nsec, sec;
23 21
24 vdata[CS_HRES_COARSE].cycle_last 22 vdata[CS_HRES_COARSE].cycle_last = tk->tkr_mono.cycle_last;
25 #ifdef CONFIG_GENERIC_VDSO_OVERFLOW_PROTECT <<
26 vdata[CS_HRES_COARSE].max_cycles <<
27 #endif <<
28 vdata[CS_HRES_COARSE].mask 23 vdata[CS_HRES_COARSE].mask = tk->tkr_mono.mask;
29 vdata[CS_HRES_COARSE].mult 24 vdata[CS_HRES_COARSE].mult = tk->tkr_mono.mult;
30 vdata[CS_HRES_COARSE].shift 25 vdata[CS_HRES_COARSE].shift = tk->tkr_mono.shift;
31 vdata[CS_RAW].cycle_last 26 vdata[CS_RAW].cycle_last = tk->tkr_raw.cycle_last;
32 #ifdef CONFIG_GENERIC_VDSO_OVERFLOW_PROTECT <<
33 vdata[CS_RAW].max_cycles <<
34 #endif <<
35 vdata[CS_RAW].mask 27 vdata[CS_RAW].mask = tk->tkr_raw.mask;
36 vdata[CS_RAW].mult 28 vdata[CS_RAW].mult = tk->tkr_raw.mult;
37 vdata[CS_RAW].shift 29 vdata[CS_RAW].shift = tk->tkr_raw.shift;
38 30
39 /* CLOCK_MONOTONIC */ 31 /* CLOCK_MONOTONIC */
40 vdso_ts = &vdata[CS_HRES_COARS 32 vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_MONOTONIC];
41 vdso_ts->sec = tk->xtime_sec + tk-> 33 vdso_ts->sec = tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
42 34
43 nsec = tk->tkr_mono.xtime_nsec; 35 nsec = tk->tkr_mono.xtime_nsec;
44 nsec += ((u64)tk->wall_to_monotonic.tv 36 nsec += ((u64)tk->wall_to_monotonic.tv_nsec << tk->tkr_mono.shift);
45 while (nsec >= (((u64)NSEC_PER_SEC) << 37 while (nsec >= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) {
46 nsec -= (((u64)NSEC_PER_SEC) < 38 nsec -= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift);
47 vdso_ts->sec++; 39 vdso_ts->sec++;
48 } 40 }
49 vdso_ts->nsec = nsec; 41 vdso_ts->nsec = nsec;
50 42
51 /* Copy MONOTONIC time for BOOTTIME */ 43 /* Copy MONOTONIC time for BOOTTIME */
52 sec = vdso_ts->sec; 44 sec = vdso_ts->sec;
53 /* Add the boot offset */ 45 /* Add the boot offset */
54 sec += tk->monotonic_to_boot.tv_se 46 sec += tk->monotonic_to_boot.tv_sec;
55 nsec += (u64)tk->monotonic_to_boot. 47 nsec += (u64)tk->monotonic_to_boot.tv_nsec << tk->tkr_mono.shift;
56 48
57 /* CLOCK_BOOTTIME */ 49 /* CLOCK_BOOTTIME */
58 vdso_ts = &vdata[CS_HRES_COARS 50 vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_BOOTTIME];
59 vdso_ts->sec = sec; 51 vdso_ts->sec = sec;
60 52
61 while (nsec >= (((u64)NSEC_PER_SEC) << 53 while (nsec >= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) {
62 nsec -= (((u64)NSEC_PER_SEC) < 54 nsec -= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift);
63 vdso_ts->sec++; 55 vdso_ts->sec++;
64 } 56 }
65 vdso_ts->nsec = nsec; 57 vdso_ts->nsec = nsec;
66 58
67 /* CLOCK_MONOTONIC_RAW */ 59 /* CLOCK_MONOTONIC_RAW */
68 vdso_ts = &vdata[CS_RAW].baset 60 vdso_ts = &vdata[CS_RAW].basetime[CLOCK_MONOTONIC_RAW];
69 vdso_ts->sec = tk->raw_sec; 61 vdso_ts->sec = tk->raw_sec;
70 vdso_ts->nsec = tk->tkr_raw.xtime_ns 62 vdso_ts->nsec = tk->tkr_raw.xtime_nsec;
71 63
72 /* CLOCK_TAI */ 64 /* CLOCK_TAI */
73 vdso_ts = &vdata[CS_HRES_COARS 65 vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_TAI];
74 vdso_ts->sec = tk->xtime_sec + (s64 66 vdso_ts->sec = tk->xtime_sec + (s64)tk->tai_offset;
75 vdso_ts->nsec = tk->tkr_mono.xtime_n 67 vdso_ts->nsec = tk->tkr_mono.xtime_nsec;
76 } 68 }
77 69
78 void update_vsyscall(struct timekeeper *tk) 70 void update_vsyscall(struct timekeeper *tk)
79 { 71 {
80 struct vdso_data *vdata = __arch_get_k 72 struct vdso_data *vdata = __arch_get_k_vdso_data();
81 struct vdso_timestamp *vdso_ts; 73 struct vdso_timestamp *vdso_ts;
82 s32 clock_mode; <<
83 u64 nsec; 74 u64 nsec;
84 75
85 /* copy vsyscall data */ 76 /* copy vsyscall data */
86 vdso_write_begin(vdata); 77 vdso_write_begin(vdata);
87 78
88 clock_mode = tk->tkr_mono.clock->vdso_ !! 79 vdata[CS_HRES_COARSE].clock_mode = __arch_get_clock_mode(tk);
89 vdata[CS_HRES_COARSE].clock_mode !! 80 vdata[CS_RAW].clock_mode = __arch_get_clock_mode(tk);
90 vdata[CS_RAW].clock_mode <<
91 81
92 /* CLOCK_REALTIME also required for ti 82 /* CLOCK_REALTIME also required for time() */
93 vdso_ts = &vdata[CS_HRES_COARS 83 vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_REALTIME];
94 vdso_ts->sec = tk->xtime_sec; 84 vdso_ts->sec = tk->xtime_sec;
95 vdso_ts->nsec = tk->tkr_mono.xtime_n 85 vdso_ts->nsec = tk->tkr_mono.xtime_nsec;
96 86
97 /* CLOCK_REALTIME_COARSE */ 87 /* CLOCK_REALTIME_COARSE */
98 vdso_ts = &vdata[CS_HRES_COARS 88 vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_REALTIME_COARSE];
99 vdso_ts->sec = tk->xtime_sec; 89 vdso_ts->sec = tk->xtime_sec;
100 vdso_ts->nsec = tk->tkr_mono.xtime_n 90 vdso_ts->nsec = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift;
101 91
102 /* CLOCK_MONOTONIC_COARSE */ 92 /* CLOCK_MONOTONIC_COARSE */
103 vdso_ts = &vdata[CS_HRES_COARS 93 vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_MONOTONIC_COARSE];
104 vdso_ts->sec = tk->xtime_sec + tk-> 94 vdso_ts->sec = tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
105 nsec = tk->tkr_mono.xtime_n 95 nsec = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift;
106 nsec = nsec + tk->wall_to_m 96 nsec = nsec + tk->wall_to_monotonic.tv_nsec;
107 vdso_ts->sec += __iter_div_u64_rem( 97 vdso_ts->sec += __iter_div_u64_rem(nsec, NSEC_PER_SEC, &vdso_ts->nsec);
108 98
109 /* 99 /*
110 * Read without the seqlock held by cl 100 * Read without the seqlock held by clock_getres().
111 * Note: No need to have a second copy 101 * Note: No need to have a second copy.
112 */ 102 */
113 WRITE_ONCE(vdata[CS_HRES_COARSE].hrtim 103 WRITE_ONCE(vdata[CS_HRES_COARSE].hrtimer_res, hrtimer_resolution);
114 104
115 /* 105 /*
116 * If the current clocksource is not V !! 106 * Architectures can opt out of updating the high resolution part
117 * update of the high resolution parts !! 107 * of the VDSO.
118 */ 108 */
119 if (clock_mode != VDSO_CLOCKMODE_NONE) !! 109 if (__arch_update_vdso_data())
120 update_vdso_data(vdata, tk); 110 update_vdso_data(vdata, tk);
121 111
122 __arch_update_vsyscall(vdata, tk); 112 __arch_update_vsyscall(vdata, tk);
123 113
124 vdso_write_end(vdata); 114 vdso_write_end(vdata);
125 115
126 __arch_sync_vdso_data(vdata); 116 __arch_sync_vdso_data(vdata);
127 } 117 }
128 118
129 void update_vsyscall_tz(void) 119 void update_vsyscall_tz(void)
130 { 120 {
131 struct vdso_data *vdata = __arch_get_k 121 struct vdso_data *vdata = __arch_get_k_vdso_data();
132 122
133 vdata[CS_HRES_COARSE].tz_minuteswest = 123 vdata[CS_HRES_COARSE].tz_minuteswest = sys_tz.tz_minuteswest;
134 vdata[CS_HRES_COARSE].tz_dsttime = sys 124 vdata[CS_HRES_COARSE].tz_dsttime = sys_tz.tz_dsttime;
135 125
136 __arch_sync_vdso_data(vdata); 126 __arch_sync_vdso_data(vdata);
137 } <<
138 <<
139 /** <<
140 * vdso_update_begin - Start of a VDSO update <<
141 * <<
142 * Allows architecture code to safely update t <<
143 * data. Disables interrupts, acquires timekee <<
144 * concurrent updates from timekeeping and inv <<
145 * sequence counter to prevent concurrent read <<
146 * inconsistent data. <<
147 * <<
148 * Returns: Saved interrupt flags which need t <<
149 * vdso_update_end(). <<
150 */ <<
151 unsigned long vdso_update_begin(void) <<
152 { <<
153 struct vdso_data *vdata = __arch_get_k <<
154 unsigned long flags; <<
155 <<
156 raw_spin_lock_irqsave(&timekeeper_lock <<
157 vdso_write_begin(vdata); <<
158 return flags; <<
159 } <<
160 <<
161 /** <<
162 * vdso_update_end - End of a VDSO update sect <<
163 * @flags: Interrupt flags as returned fr <<
164 * <<
165 * Pairs with vdso_update_begin(). Marks vdso <<
166 * synchronization if the architecture require <<
167 * and restores interrupt flags. <<
168 */ <<
169 void vdso_update_end(unsigned long flags) <<
170 { <<
171 struct vdso_data *vdata = __arch_get_k <<
172 <<
173 vdso_write_end(vdata); <<
174 __arch_sync_vdso_data(vdata); <<
175 raw_spin_unlock_irqrestore(&timekeeper <<
176 } 127 }
177 128
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.