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
>> 31 /* CLOCK_REALTIME */
>> 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;
>> 35
39 /* CLOCK_MONOTONIC */ 36 /* CLOCK_MONOTONIC */
40 vdso_ts = &vdata[CS_HRES_COARS 37 vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_MONOTONIC];
41 vdso_ts->sec = tk->xtime_sec + tk-> 38 vdso_ts->sec = tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
42 39
43 nsec = tk->tkr_mono.xtime_nsec; 40 nsec = tk->tkr_mono.xtime_nsec;
44 nsec += ((u64)tk->wall_to_monotonic.tv 41 nsec += ((u64)tk->wall_to_monotonic.tv_nsec << tk->tkr_mono.shift);
45 while (nsec >= (((u64)NSEC_PER_SEC) << 42 while (nsec >= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) {
46 nsec -= (((u64)NSEC_PER_SEC) < 43 nsec -= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift);
47 vdso_ts->sec++; 44 vdso_ts->sec++;
48 } 45 }
49 vdso_ts->nsec = nsec; 46 vdso_ts->nsec = nsec;
50 47
51 /* Copy MONOTONIC time for BOOTTIME */ 48 /* Copy MONOTONIC time for BOOTTIME */
52 sec = vdso_ts->sec; 49 sec = vdso_ts->sec;
53 /* Add the boot offset */ 50 /* Add the boot offset */
54 sec += tk->monotonic_to_boot.tv_se 51 sec += tk->monotonic_to_boot.tv_sec;
55 nsec += (u64)tk->monotonic_to_boot. 52 nsec += (u64)tk->monotonic_to_boot.tv_nsec << tk->tkr_mono.shift;
56 53
57 /* CLOCK_BOOTTIME */ 54 /* CLOCK_BOOTTIME */
58 vdso_ts = &vdata[CS_HRES_COARS 55 vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_BOOTTIME];
59 vdso_ts->sec = sec; 56 vdso_ts->sec = sec;
60 57
61 while (nsec >= (((u64)NSEC_PER_SEC) << 58 while (nsec >= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) {
62 nsec -= (((u64)NSEC_PER_SEC) < 59 nsec -= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift);
63 vdso_ts->sec++; 60 vdso_ts->sec++;
64 } 61 }
65 vdso_ts->nsec = nsec; 62 vdso_ts->nsec = nsec;
66 63
67 /* CLOCK_MONOTONIC_RAW */ 64 /* CLOCK_MONOTONIC_RAW */
68 vdso_ts = &vdata[CS_RAW].baset 65 vdso_ts = &vdata[CS_RAW].basetime[CLOCK_MONOTONIC_RAW];
69 vdso_ts->sec = tk->raw_sec; 66 vdso_ts->sec = tk->raw_sec;
70 vdso_ts->nsec = tk->tkr_raw.xtime_ns 67 vdso_ts->nsec = tk->tkr_raw.xtime_nsec;
71 68
72 /* CLOCK_TAI */ 69 /* CLOCK_TAI */
73 vdso_ts = &vdata[CS_HRES_COARS 70 vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_TAI];
74 vdso_ts->sec = tk->xtime_sec + (s64 71 vdso_ts->sec = tk->xtime_sec + (s64)tk->tai_offset;
75 vdso_ts->nsec = tk->tkr_mono.xtime_n 72 vdso_ts->nsec = tk->tkr_mono.xtime_nsec;
>> 73
>> 74 /*
>> 75 * Read without the seqlock held by clock_getres().
>> 76 * Note: No need to have a second copy.
>> 77 */
>> 78 WRITE_ONCE(vdata[CS_HRES_COARSE].hrtimer_res, hrtimer_resolution);
76 } 79 }
77 80
78 void update_vsyscall(struct timekeeper *tk) 81 void update_vsyscall(struct timekeeper *tk)
79 { 82 {
80 struct vdso_data *vdata = __arch_get_k 83 struct vdso_data *vdata = __arch_get_k_vdso_data();
81 struct vdso_timestamp *vdso_ts; 84 struct vdso_timestamp *vdso_ts;
82 s32 clock_mode; <<
83 u64 nsec; 85 u64 nsec;
84 86
>> 87 if (__arch_update_vdso_data()) {
>> 88 /*
>> 89 * Some architectures might want to skip the update of the
>> 90 * data page.
>> 91 */
>> 92 return;
>> 93 }
>> 94
85 /* copy vsyscall data */ 95 /* copy vsyscall data */
86 vdso_write_begin(vdata); 96 vdso_write_begin(vdata);
87 97
88 clock_mode = tk->tkr_mono.clock->vdso_ !! 98 vdata[CS_HRES_COARSE].clock_mode = __arch_get_clock_mode(tk);
89 vdata[CS_HRES_COARSE].clock_mode !! 99 vdata[CS_RAW].clock_mode = __arch_get_clock_mode(tk);
90 vdata[CS_RAW].clock_mode <<
91 <<
92 /* CLOCK_REALTIME also required for ti <<
93 vdso_ts = &vdata[CS_HRES_COARS <<
94 vdso_ts->sec = tk->xtime_sec; <<
95 vdso_ts->nsec = tk->tkr_mono.xtime_n <<
96 100
97 /* CLOCK_REALTIME_COARSE */ 101 /* CLOCK_REALTIME_COARSE */
98 vdso_ts = &vdata[CS_HRES_COARS 102 vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_REALTIME_COARSE];
99 vdso_ts->sec = tk->xtime_sec; 103 vdso_ts->sec = tk->xtime_sec;
100 vdso_ts->nsec = tk->tkr_mono.xtime_n 104 vdso_ts->nsec = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift;
101 105
102 /* CLOCK_MONOTONIC_COARSE */ 106 /* CLOCK_MONOTONIC_COARSE */
103 vdso_ts = &vdata[CS_HRES_COARS 107 vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_MONOTONIC_COARSE];
104 vdso_ts->sec = tk->xtime_sec + tk-> 108 vdso_ts->sec = tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
105 nsec = tk->tkr_mono.xtime_n 109 nsec = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift;
106 nsec = nsec + tk->wall_to_m 110 nsec = nsec + tk->wall_to_monotonic.tv_nsec;
107 vdso_ts->sec += __iter_div_u64_rem( 111 vdso_ts->sec += __iter_div_u64_rem(nsec, NSEC_PER_SEC, &vdso_ts->nsec);
108 112
109 /* !! 113 update_vdso_data(vdata, tk);
110 * Read without the seqlock held by cl <<
111 * Note: No need to have a second copy <<
112 */ <<
113 WRITE_ONCE(vdata[CS_HRES_COARSE].hrtim <<
114 <<
115 /* <<
116 * If the current clocksource is not V <<
117 * update of the high resolution parts <<
118 */ <<
119 if (clock_mode != VDSO_CLOCKMODE_NONE) <<
120 update_vdso_data(vdata, tk); <<
121 114
122 __arch_update_vsyscall(vdata, tk); 115 __arch_update_vsyscall(vdata, tk);
123 116
124 vdso_write_end(vdata); 117 vdso_write_end(vdata);
125 118
126 __arch_sync_vdso_data(vdata); 119 __arch_sync_vdso_data(vdata);
127 } 120 }
128 121
129 void update_vsyscall_tz(void) 122 void update_vsyscall_tz(void)
130 { 123 {
131 struct vdso_data *vdata = __arch_get_k 124 struct vdso_data *vdata = __arch_get_k_vdso_data();
132 125
133 vdata[CS_HRES_COARSE].tz_minuteswest = 126 vdata[CS_HRES_COARSE].tz_minuteswest = sys_tz.tz_minuteswest;
134 vdata[CS_HRES_COARSE].tz_dsttime = sys 127 vdata[CS_HRES_COARSE].tz_dsttime = sys_tz.tz_dsttime;
135 128
136 __arch_sync_vdso_data(vdata); 129 __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 } 130 }
177 131
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