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