john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/kernel/time/timekeeping.c |
| 3 | * |
| 4 | * Kernel timekeeping code and accessor functions |
| 5 | * |
| 6 | * This code was moved from linux/kernel/timer.c. |
| 7 | * Please see that file for copyright and history logs. |
| 8 | * |
| 9 | */ |
| 10 | |
John Stultz | d7b4202 | 2012-09-04 15:12:07 -0400 | [diff] [blame] | 11 | #include <linux/timekeeper_internal.h> |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 12 | #include <linux/module.h> |
| 13 | #include <linux/interrupt.h> |
| 14 | #include <linux/percpu.h> |
| 15 | #include <linux/init.h> |
| 16 | #include <linux/mm.h> |
Alexey Dobriyan | d43c36d | 2009-10-07 17:09:06 +0400 | [diff] [blame] | 17 | #include <linux/sched.h> |
Rafael J. Wysocki | e1a85b2 | 2011-03-23 22:16:04 +0100 | [diff] [blame] | 18 | #include <linux/syscore_ops.h> |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 19 | #include <linux/clocksource.h> |
| 20 | #include <linux/jiffies.h> |
| 21 | #include <linux/time.h> |
| 22 | #include <linux/tick.h> |
Martin Schwidefsky | 75c5158 | 2009-08-14 15:47:30 +0200 | [diff] [blame] | 23 | #include <linux/stop_machine.h> |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 24 | |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 25 | |
H Hartley Sweeten | afa14e7 | 2011-01-11 17:59:38 -0600 | [diff] [blame] | 26 | static struct timekeeper timekeeper; |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 27 | |
John Stultz | 8fcce54 | 2011-11-14 11:46:39 -0800 | [diff] [blame] | 28 | /* flag for if timekeeping is suspended */ |
| 29 | int __read_mostly timekeeping_suspended; |
| 30 | |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 31 | static inline void tk_normalize_xtime(struct timekeeper *tk) |
| 32 | { |
| 33 | while (tk->xtime_nsec >= ((u64)NSEC_PER_SEC << tk->shift)) { |
| 34 | tk->xtime_nsec -= (u64)NSEC_PER_SEC << tk->shift; |
| 35 | tk->xtime_sec++; |
| 36 | } |
| 37 | } |
John Stultz | 8fcce54 | 2011-11-14 11:46:39 -0800 | [diff] [blame] | 38 | |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 39 | static void tk_set_xtime(struct timekeeper *tk, const struct timespec *ts) |
| 40 | { |
| 41 | tk->xtime_sec = ts->tv_sec; |
John Stultz | b44d50d | 2012-07-23 16:22:37 -0400 | [diff] [blame] | 42 | tk->xtime_nsec = (u64)ts->tv_nsec << tk->shift; |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 43 | } |
| 44 | |
| 45 | static void tk_xtime_add(struct timekeeper *tk, const struct timespec *ts) |
| 46 | { |
| 47 | tk->xtime_sec += ts->tv_sec; |
John Stultz | b44d50d | 2012-07-23 16:22:37 -0400 | [diff] [blame] | 48 | tk->xtime_nsec += (u64)ts->tv_nsec << tk->shift; |
John Stultz | 784ffcb | 2012-08-21 20:30:46 -0400 | [diff] [blame] | 49 | tk_normalize_xtime(tk); |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 50 | } |
John Stultz | 8fcce54 | 2011-11-14 11:46:39 -0800 | [diff] [blame] | 51 | |
John Stultz | 6d0ef90 | 2012-07-27 14:48:12 -0400 | [diff] [blame] | 52 | static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec wtm) |
| 53 | { |
| 54 | struct timespec tmp; |
| 55 | |
| 56 | /* |
| 57 | * Verify consistency of: offset_real = -wall_to_monotonic |
| 58 | * before modifying anything |
| 59 | */ |
| 60 | set_normalized_timespec(&tmp, -tk->wall_to_monotonic.tv_sec, |
| 61 | -tk->wall_to_monotonic.tv_nsec); |
| 62 | WARN_ON_ONCE(tk->offs_real.tv64 != timespec_to_ktime(tmp).tv64); |
| 63 | tk->wall_to_monotonic = wtm; |
| 64 | set_normalized_timespec(&tmp, -wtm.tv_sec, -wtm.tv_nsec); |
| 65 | tk->offs_real = timespec_to_ktime(tmp); |
| 66 | } |
| 67 | |
| 68 | static void tk_set_sleep_time(struct timekeeper *tk, struct timespec t) |
| 69 | { |
| 70 | /* Verify consistency before modifying */ |
| 71 | WARN_ON_ONCE(tk->offs_boot.tv64 != timespec_to_ktime(tk->total_sleep_time).tv64); |
| 72 | |
| 73 | tk->total_sleep_time = t; |
| 74 | tk->offs_boot = timespec_to_ktime(t); |
| 75 | } |
| 76 | |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 77 | /** |
| 78 | * timekeeper_setup_internals - Set up internals to use clocksource clock. |
| 79 | * |
| 80 | * @clock: Pointer to clocksource. |
| 81 | * |
| 82 | * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment |
| 83 | * pair and interval request. |
| 84 | * |
| 85 | * Unless you're the timekeeping code, you should not be using this! |
| 86 | */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 87 | static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock) |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 88 | { |
| 89 | cycle_t interval; |
Kasper Pedersen | a386b5a | 2010-10-20 15:55:15 -0700 | [diff] [blame] | 90 | u64 tmp, ntpinterval; |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 91 | struct clocksource *old_clock; |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 92 | |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 93 | old_clock = tk->clock; |
| 94 | tk->clock = clock; |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 95 | clock->cycle_last = clock->read(clock); |
| 96 | |
| 97 | /* Do the ns -> cycle conversion first, using original mult */ |
| 98 | tmp = NTP_INTERVAL_LENGTH; |
| 99 | tmp <<= clock->shift; |
Kasper Pedersen | a386b5a | 2010-10-20 15:55:15 -0700 | [diff] [blame] | 100 | ntpinterval = tmp; |
Martin Schwidefsky | 0a54419 | 2009-08-14 15:47:28 +0200 | [diff] [blame] | 101 | tmp += clock->mult/2; |
| 102 | do_div(tmp, clock->mult); |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 103 | if (tmp == 0) |
| 104 | tmp = 1; |
| 105 | |
| 106 | interval = (cycle_t) tmp; |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 107 | tk->cycle_interval = interval; |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 108 | |
| 109 | /* Go back from cycles -> shifted ns */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 110 | tk->xtime_interval = (u64) interval * clock->mult; |
| 111 | tk->xtime_remainder = ntpinterval - tk->xtime_interval; |
| 112 | tk->raw_interval = |
Martin Schwidefsky | 0a54419 | 2009-08-14 15:47:28 +0200 | [diff] [blame] | 113 | ((u64) interval * clock->mult) >> clock->shift; |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 114 | |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 115 | /* if changing clocks, convert xtime_nsec shift units */ |
| 116 | if (old_clock) { |
| 117 | int shift_change = clock->shift - old_clock->shift; |
| 118 | if (shift_change < 0) |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 119 | tk->xtime_nsec >>= -shift_change; |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 120 | else |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 121 | tk->xtime_nsec <<= shift_change; |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 122 | } |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 123 | tk->shift = clock->shift; |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 124 | |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 125 | tk->ntp_error = 0; |
| 126 | tk->ntp_error_shift = NTP_SCALE_SHIFT - clock->shift; |
Martin Schwidefsky | 0a54419 | 2009-08-14 15:47:28 +0200 | [diff] [blame] | 127 | |
| 128 | /* |
| 129 | * The timekeeper keeps its own mult values for the currently |
| 130 | * active clocksource. These value will be adjusted via NTP |
| 131 | * to counteract clock drifting. |
| 132 | */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 133 | tk->mult = clock->mult; |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 134 | } |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 135 | |
Martin Schwidefsky | 2ba2a30 | 2009-08-14 15:47:29 +0200 | [diff] [blame] | 136 | /* Timekeeper helper functions. */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 137 | static inline s64 timekeeping_get_ns(struct timekeeper *tk) |
Martin Schwidefsky | 2ba2a30 | 2009-08-14 15:47:29 +0200 | [diff] [blame] | 138 | { |
| 139 | cycle_t cycle_now, cycle_delta; |
| 140 | struct clocksource *clock; |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 141 | s64 nsec; |
Martin Schwidefsky | 2ba2a30 | 2009-08-14 15:47:29 +0200 | [diff] [blame] | 142 | |
| 143 | /* read clocksource: */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 144 | clock = tk->clock; |
Martin Schwidefsky | 2ba2a30 | 2009-08-14 15:47:29 +0200 | [diff] [blame] | 145 | cycle_now = clock->read(clock); |
| 146 | |
| 147 | /* calculate the delta since the last update_wall_time: */ |
| 148 | cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; |
| 149 | |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 150 | nsec = cycle_delta * tk->mult + tk->xtime_nsec; |
| 151 | nsec >>= tk->shift; |
John Stultz | f2a5a08 | 2012-07-13 01:21:55 -0400 | [diff] [blame] | 152 | |
| 153 | /* If arch requires, add in gettimeoffset() */ |
| 154 | return nsec + arch_gettimeoffset(); |
Martin Schwidefsky | 2ba2a30 | 2009-08-14 15:47:29 +0200 | [diff] [blame] | 155 | } |
| 156 | |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 157 | static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk) |
Martin Schwidefsky | 2ba2a30 | 2009-08-14 15:47:29 +0200 | [diff] [blame] | 158 | { |
| 159 | cycle_t cycle_now, cycle_delta; |
| 160 | struct clocksource *clock; |
John Stultz | f2a5a08 | 2012-07-13 01:21:55 -0400 | [diff] [blame] | 161 | s64 nsec; |
Martin Schwidefsky | 2ba2a30 | 2009-08-14 15:47:29 +0200 | [diff] [blame] | 162 | |
| 163 | /* read clocksource: */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 164 | clock = tk->clock; |
Martin Schwidefsky | 2ba2a30 | 2009-08-14 15:47:29 +0200 | [diff] [blame] | 165 | cycle_now = clock->read(clock); |
| 166 | |
| 167 | /* calculate the delta since the last update_wall_time: */ |
| 168 | cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; |
| 169 | |
John Stultz | f2a5a08 | 2012-07-13 01:21:55 -0400 | [diff] [blame] | 170 | /* convert delta to nanoseconds. */ |
| 171 | nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); |
| 172 | |
| 173 | /* If arch requires, add in gettimeoffset() */ |
| 174 | return nsec + arch_gettimeoffset(); |
Martin Schwidefsky | 2ba2a30 | 2009-08-14 15:47:29 +0200 | [diff] [blame] | 175 | } |
| 176 | |
Thomas Gleixner | cc06268 | 2011-11-13 23:19:49 +0000 | [diff] [blame] | 177 | /* must hold write on timekeeper.lock */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 178 | static void timekeeping_update(struct timekeeper *tk, bool clearntp) |
Thomas Gleixner | cc06268 | 2011-11-13 23:19:49 +0000 | [diff] [blame] | 179 | { |
| 180 | if (clearntp) { |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 181 | tk->ntp_error = 0; |
Thomas Gleixner | cc06268 | 2011-11-13 23:19:49 +0000 | [diff] [blame] | 182 | ntp_clear(); |
| 183 | } |
John Stultz | 576094b | 2012-09-11 19:58:13 -0400 | [diff] [blame] | 184 | update_vsyscall(tk); |
Thomas Gleixner | cc06268 | 2011-11-13 23:19:49 +0000 | [diff] [blame] | 185 | } |
| 186 | |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 187 | /** |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 188 | * timekeeping_forward_now - update clock to the current time |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 189 | * |
Roman Zippel | 9a05511 | 2008-08-20 16:37:28 -0700 | [diff] [blame] | 190 | * Forward the current clock to update its state since the last call to |
| 191 | * update_wall_time(). This is useful before significant clock changes, |
| 192 | * as it avoids having to deal with this time offset explicitly. |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 193 | */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 194 | static void timekeeping_forward_now(struct timekeeper *tk) |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 195 | { |
| 196 | cycle_t cycle_now, cycle_delta; |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 197 | struct clocksource *clock; |
Roman Zippel | 9a05511 | 2008-08-20 16:37:28 -0700 | [diff] [blame] | 198 | s64 nsec; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 199 | |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 200 | clock = tk->clock; |
Martin Schwidefsky | a0f7d48 | 2009-08-14 15:47:19 +0200 | [diff] [blame] | 201 | cycle_now = clock->read(clock); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 202 | cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; |
Roman Zippel | 9a05511 | 2008-08-20 16:37:28 -0700 | [diff] [blame] | 203 | clock->cycle_last = cycle_now; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 204 | |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 205 | tk->xtime_nsec += cycle_delta * tk->mult; |
john stultz | 7d27558 | 2009-05-01 13:10:26 -0700 | [diff] [blame] | 206 | |
| 207 | /* If arch requires, add in gettimeoffset() */ |
Andreas Schwab | 85dc8f0 | 2012-08-21 20:30:47 -0400 | [diff] [blame] | 208 | tk->xtime_nsec += (u64)arch_gettimeoffset() << tk->shift; |
john stultz | 7d27558 | 2009-05-01 13:10:26 -0700 | [diff] [blame] | 209 | |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 210 | tk_normalize_xtime(tk); |
John Stultz | 2d42244 | 2008-08-20 16:37:30 -0700 | [diff] [blame] | 211 | |
Martin Schwidefsky | 0a54419 | 2009-08-14 15:47:28 +0200 | [diff] [blame] | 212 | nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 213 | timespec_add_ns(&tk->raw_time, nsec); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 214 | } |
| 215 | |
| 216 | /** |
Geert Uytterhoeven | efd9ac8 | 2008-01-30 13:30:01 +0100 | [diff] [blame] | 217 | * getnstimeofday - Returns the time of day in a timespec |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 218 | * @ts: pointer to the timespec to be set |
| 219 | * |
Geert Uytterhoeven | efd9ac8 | 2008-01-30 13:30:01 +0100 | [diff] [blame] | 220 | * Returns the time of day in a timespec. |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 221 | */ |
Geert Uytterhoeven | efd9ac8 | 2008-01-30 13:30:01 +0100 | [diff] [blame] | 222 | void getnstimeofday(struct timespec *ts) |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 223 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 224 | struct timekeeper *tk = &timekeeper; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 225 | unsigned long seq; |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 226 | s64 nsecs = 0; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 227 | |
Thomas Gleixner | 1c5745a | 2008-12-22 23:05:28 +0100 | [diff] [blame] | 228 | WARN_ON(timekeeping_suspended); |
| 229 | |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 230 | do { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 231 | seq = read_seqbegin(&tk->lock); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 232 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 233 | ts->tv_sec = tk->xtime_sec; |
John Stultz | ec145ba | 2012-09-11 19:26:03 -0400 | [diff] [blame] | 234 | nsecs = timekeeping_get_ns(tk); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 235 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 236 | } while (read_seqretry(&tk->lock, seq)); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 237 | |
John Stultz | ec145ba | 2012-09-11 19:26:03 -0400 | [diff] [blame] | 238 | ts->tv_nsec = 0; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 239 | timespec_add_ns(ts, nsecs); |
| 240 | } |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 241 | EXPORT_SYMBOL(getnstimeofday); |
| 242 | |
Martin Schwidefsky | 951ed4d | 2009-07-07 11:27:28 +0200 | [diff] [blame] | 243 | ktime_t ktime_get(void) |
| 244 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 245 | struct timekeeper *tk = &timekeeper; |
Martin Schwidefsky | 951ed4d | 2009-07-07 11:27:28 +0200 | [diff] [blame] | 246 | unsigned int seq; |
| 247 | s64 secs, nsecs; |
| 248 | |
| 249 | WARN_ON(timekeeping_suspended); |
| 250 | |
| 251 | do { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 252 | seq = read_seqbegin(&tk->lock); |
| 253 | secs = tk->xtime_sec + tk->wall_to_monotonic.tv_sec; |
| 254 | nsecs = timekeeping_get_ns(tk) + tk->wall_to_monotonic.tv_nsec; |
Martin Schwidefsky | 951ed4d | 2009-07-07 11:27:28 +0200 | [diff] [blame] | 255 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 256 | } while (read_seqretry(&tk->lock, seq)); |
Martin Schwidefsky | 951ed4d | 2009-07-07 11:27:28 +0200 | [diff] [blame] | 257 | /* |
| 258 | * Use ktime_set/ktime_add_ns to create a proper ktime on |
| 259 | * 32-bit architectures without CONFIG_KTIME_SCALAR. |
| 260 | */ |
| 261 | return ktime_add_ns(ktime_set(secs, 0), nsecs); |
| 262 | } |
| 263 | EXPORT_SYMBOL_GPL(ktime_get); |
| 264 | |
| 265 | /** |
| 266 | * ktime_get_ts - get the monotonic clock in timespec format |
| 267 | * @ts: pointer to timespec variable |
| 268 | * |
| 269 | * The function calculates the monotonic clock from the realtime |
| 270 | * clock and the wall_to_monotonic offset and stores the result |
| 271 | * in normalized timespec format in the variable pointed to by @ts. |
| 272 | */ |
| 273 | void ktime_get_ts(struct timespec *ts) |
| 274 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 275 | struct timekeeper *tk = &timekeeper; |
Martin Schwidefsky | 951ed4d | 2009-07-07 11:27:28 +0200 | [diff] [blame] | 276 | struct timespec tomono; |
John Stultz | ec145ba | 2012-09-11 19:26:03 -0400 | [diff] [blame] | 277 | s64 nsec; |
Martin Schwidefsky | 951ed4d | 2009-07-07 11:27:28 +0200 | [diff] [blame] | 278 | unsigned int seq; |
Martin Schwidefsky | 951ed4d | 2009-07-07 11:27:28 +0200 | [diff] [blame] | 279 | |
| 280 | WARN_ON(timekeeping_suspended); |
| 281 | |
| 282 | do { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 283 | seq = read_seqbegin(&tk->lock); |
| 284 | ts->tv_sec = tk->xtime_sec; |
John Stultz | ec145ba | 2012-09-11 19:26:03 -0400 | [diff] [blame] | 285 | nsec = timekeeping_get_ns(tk); |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 286 | tomono = tk->wall_to_monotonic; |
Martin Schwidefsky | 951ed4d | 2009-07-07 11:27:28 +0200 | [diff] [blame] | 287 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 288 | } while (read_seqretry(&tk->lock, seq)); |
Martin Schwidefsky | 951ed4d | 2009-07-07 11:27:28 +0200 | [diff] [blame] | 289 | |
John Stultz | ec145ba | 2012-09-11 19:26:03 -0400 | [diff] [blame] | 290 | ts->tv_sec += tomono.tv_sec; |
| 291 | ts->tv_nsec = 0; |
| 292 | timespec_add_ns(ts, nsec + tomono.tv_nsec); |
Martin Schwidefsky | 951ed4d | 2009-07-07 11:27:28 +0200 | [diff] [blame] | 293 | } |
| 294 | EXPORT_SYMBOL_GPL(ktime_get_ts); |
| 295 | |
Alexander Gordeev | e2c18e4 | 2011-01-12 17:00:57 -0800 | [diff] [blame] | 296 | #ifdef CONFIG_NTP_PPS |
| 297 | |
| 298 | /** |
| 299 | * getnstime_raw_and_real - get day and raw monotonic time in timespec format |
| 300 | * @ts_raw: pointer to the timespec to be set to raw monotonic time |
| 301 | * @ts_real: pointer to the timespec to be set to the time of day |
| 302 | * |
| 303 | * This function reads both the time of day and raw monotonic time at the |
| 304 | * same time atomically and stores the resulting timestamps in timespec |
| 305 | * format. |
| 306 | */ |
| 307 | void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real) |
| 308 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 309 | struct timekeeper *tk = &timekeeper; |
Alexander Gordeev | e2c18e4 | 2011-01-12 17:00:57 -0800 | [diff] [blame] | 310 | unsigned long seq; |
| 311 | s64 nsecs_raw, nsecs_real; |
| 312 | |
| 313 | WARN_ON_ONCE(timekeeping_suspended); |
| 314 | |
| 315 | do { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 316 | seq = read_seqbegin(&tk->lock); |
Alexander Gordeev | e2c18e4 | 2011-01-12 17:00:57 -0800 | [diff] [blame] | 317 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 318 | *ts_raw = tk->raw_time; |
| 319 | ts_real->tv_sec = tk->xtime_sec; |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 320 | ts_real->tv_nsec = 0; |
Alexander Gordeev | e2c18e4 | 2011-01-12 17:00:57 -0800 | [diff] [blame] | 321 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 322 | nsecs_raw = timekeeping_get_ns_raw(tk); |
| 323 | nsecs_real = timekeeping_get_ns(tk); |
Alexander Gordeev | e2c18e4 | 2011-01-12 17:00:57 -0800 | [diff] [blame] | 324 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 325 | } while (read_seqretry(&tk->lock, seq)); |
Alexander Gordeev | e2c18e4 | 2011-01-12 17:00:57 -0800 | [diff] [blame] | 326 | |
| 327 | timespec_add_ns(ts_raw, nsecs_raw); |
| 328 | timespec_add_ns(ts_real, nsecs_real); |
| 329 | } |
| 330 | EXPORT_SYMBOL(getnstime_raw_and_real); |
| 331 | |
| 332 | #endif /* CONFIG_NTP_PPS */ |
| 333 | |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 334 | /** |
| 335 | * do_gettimeofday - Returns the time of day in a timeval |
| 336 | * @tv: pointer to the timeval to be set |
| 337 | * |
Geert Uytterhoeven | efd9ac8 | 2008-01-30 13:30:01 +0100 | [diff] [blame] | 338 | * NOTE: Users should be converted to using getnstimeofday() |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 339 | */ |
| 340 | void do_gettimeofday(struct timeval *tv) |
| 341 | { |
| 342 | struct timespec now; |
| 343 | |
Geert Uytterhoeven | efd9ac8 | 2008-01-30 13:30:01 +0100 | [diff] [blame] | 344 | getnstimeofday(&now); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 345 | tv->tv_sec = now.tv_sec; |
| 346 | tv->tv_usec = now.tv_nsec/1000; |
| 347 | } |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 348 | EXPORT_SYMBOL(do_gettimeofday); |
Richard Cochran | d239f49 | 2012-04-27 10:12:42 +0200 | [diff] [blame] | 349 | |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 350 | /** |
| 351 | * do_settimeofday - Sets the time of day |
| 352 | * @tv: pointer to the timespec variable containing the new time |
| 353 | * |
| 354 | * Sets the time of day to the new time and update NTP and notify hrtimers |
| 355 | */ |
Richard Cochran | 1e6d767 | 2011-02-01 13:50:58 +0000 | [diff] [blame] | 356 | int do_settimeofday(const struct timespec *tv) |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 357 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 358 | struct timekeeper *tk = &timekeeper; |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 359 | struct timespec ts_delta, xt; |
John Stultz | 92c1d3e | 2011-11-14 14:05:44 -0800 | [diff] [blame] | 360 | unsigned long flags; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 361 | |
John Stultz | cee5848 | 2012-08-31 13:30:06 -0400 | [diff] [blame] | 362 | if (!timespec_valid_strict(tv)) |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 363 | return -EINVAL; |
| 364 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 365 | write_seqlock_irqsave(&tk->lock, flags); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 366 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 367 | timekeeping_forward_now(tk); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 368 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 369 | xt = tk_xtime(tk); |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 370 | ts_delta.tv_sec = tv->tv_sec - xt.tv_sec; |
| 371 | ts_delta.tv_nsec = tv->tv_nsec - xt.tv_nsec; |
| 372 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 373 | tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, ts_delta)); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 374 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 375 | tk_set_xtime(tk, tv); |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 376 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 377 | timekeeping_update(tk, true); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 378 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 379 | write_sequnlock_irqrestore(&tk->lock, flags); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 380 | |
| 381 | /* signal hrtimers about time change */ |
| 382 | clock_was_set(); |
| 383 | |
| 384 | return 0; |
| 385 | } |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 386 | EXPORT_SYMBOL(do_settimeofday); |
| 387 | |
John Stultz | c528f7c | 2011-02-01 13:52:17 +0000 | [diff] [blame] | 388 | /** |
| 389 | * timekeeping_inject_offset - Adds or subtracts from the current time. |
| 390 | * @tv: pointer to the timespec variable containing the offset |
| 391 | * |
| 392 | * Adds or subtracts an offset value from the current time. |
| 393 | */ |
| 394 | int timekeeping_inject_offset(struct timespec *ts) |
| 395 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 396 | struct timekeeper *tk = &timekeeper; |
John Stultz | 92c1d3e | 2011-11-14 14:05:44 -0800 | [diff] [blame] | 397 | unsigned long flags; |
John Stultz | 4e8b145 | 2012-08-08 15:36:20 -0400 | [diff] [blame] | 398 | struct timespec tmp; |
| 399 | int ret = 0; |
John Stultz | c528f7c | 2011-02-01 13:52:17 +0000 | [diff] [blame] | 400 | |
| 401 | if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC) |
| 402 | return -EINVAL; |
| 403 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 404 | write_seqlock_irqsave(&tk->lock, flags); |
John Stultz | c528f7c | 2011-02-01 13:52:17 +0000 | [diff] [blame] | 405 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 406 | timekeeping_forward_now(tk); |
John Stultz | c528f7c | 2011-02-01 13:52:17 +0000 | [diff] [blame] | 407 | |
John Stultz | 4e8b145 | 2012-08-08 15:36:20 -0400 | [diff] [blame] | 408 | /* Make sure the proposed value is valid */ |
| 409 | tmp = timespec_add(tk_xtime(tk), *ts); |
John Stultz | cee5848 | 2012-08-31 13:30:06 -0400 | [diff] [blame] | 410 | if (!timespec_valid_strict(&tmp)) { |
John Stultz | 4e8b145 | 2012-08-08 15:36:20 -0400 | [diff] [blame] | 411 | ret = -EINVAL; |
| 412 | goto error; |
| 413 | } |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 414 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 415 | tk_xtime_add(tk, ts); |
| 416 | tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *ts)); |
John Stultz | c528f7c | 2011-02-01 13:52:17 +0000 | [diff] [blame] | 417 | |
John Stultz | 4e8b145 | 2012-08-08 15:36:20 -0400 | [diff] [blame] | 418 | error: /* even if we error out, we forwarded the time, so call update */ |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 419 | timekeeping_update(tk, true); |
John Stultz | c528f7c | 2011-02-01 13:52:17 +0000 | [diff] [blame] | 420 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 421 | write_sequnlock_irqrestore(&tk->lock, flags); |
John Stultz | c528f7c | 2011-02-01 13:52:17 +0000 | [diff] [blame] | 422 | |
| 423 | /* signal hrtimers about time change */ |
| 424 | clock_was_set(); |
| 425 | |
John Stultz | 4e8b145 | 2012-08-08 15:36:20 -0400 | [diff] [blame] | 426 | return ret; |
John Stultz | c528f7c | 2011-02-01 13:52:17 +0000 | [diff] [blame] | 427 | } |
| 428 | EXPORT_SYMBOL(timekeeping_inject_offset); |
| 429 | |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 430 | /** |
| 431 | * change_clocksource - Swaps clocksources if a new one is available |
| 432 | * |
| 433 | * Accumulates current time interval and initializes new clocksource |
| 434 | */ |
Martin Schwidefsky | 75c5158 | 2009-08-14 15:47:30 +0200 | [diff] [blame] | 435 | static int change_clocksource(void *data) |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 436 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 437 | struct timekeeper *tk = &timekeeper; |
Magnus Damm | 4614e6a | 2009-04-21 12:24:02 -0700 | [diff] [blame] | 438 | struct clocksource *new, *old; |
John Stultz | f695cf9 | 2012-03-14 16:38:15 -0700 | [diff] [blame] | 439 | unsigned long flags; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 440 | |
Martin Schwidefsky | 75c5158 | 2009-08-14 15:47:30 +0200 | [diff] [blame] | 441 | new = (struct clocksource *) data; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 442 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 443 | write_seqlock_irqsave(&tk->lock, flags); |
John Stultz | f695cf9 | 2012-03-14 16:38:15 -0700 | [diff] [blame] | 444 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 445 | timekeeping_forward_now(tk); |
Martin Schwidefsky | 75c5158 | 2009-08-14 15:47:30 +0200 | [diff] [blame] | 446 | if (!new->enable || new->enable(new) == 0) { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 447 | old = tk->clock; |
| 448 | tk_setup_internals(tk, new); |
Martin Schwidefsky | 75c5158 | 2009-08-14 15:47:30 +0200 | [diff] [blame] | 449 | if (old->disable) |
| 450 | old->disable(old); |
| 451 | } |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 452 | timekeeping_update(tk, true); |
John Stultz | f695cf9 | 2012-03-14 16:38:15 -0700 | [diff] [blame] | 453 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 454 | write_sequnlock_irqrestore(&tk->lock, flags); |
John Stultz | f695cf9 | 2012-03-14 16:38:15 -0700 | [diff] [blame] | 455 | |
Martin Schwidefsky | 75c5158 | 2009-08-14 15:47:30 +0200 | [diff] [blame] | 456 | return 0; |
| 457 | } |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 458 | |
Martin Schwidefsky | 75c5158 | 2009-08-14 15:47:30 +0200 | [diff] [blame] | 459 | /** |
| 460 | * timekeeping_notify - Install a new clock source |
| 461 | * @clock: pointer to the clock source |
| 462 | * |
| 463 | * This function is called from clocksource.c after a new, better clock |
| 464 | * source has been registered. The caller holds the clocksource_mutex. |
| 465 | */ |
| 466 | void timekeeping_notify(struct clocksource *clock) |
| 467 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 468 | struct timekeeper *tk = &timekeeper; |
| 469 | |
| 470 | if (tk->clock == clock) |
Magnus Damm | 4614e6a | 2009-04-21 12:24:02 -0700 | [diff] [blame] | 471 | return; |
Martin Schwidefsky | 75c5158 | 2009-08-14 15:47:30 +0200 | [diff] [blame] | 472 | stop_machine(change_clocksource, clock, NULL); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 473 | tick_clock_notify(); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 474 | } |
Martin Schwidefsky | 75c5158 | 2009-08-14 15:47:30 +0200 | [diff] [blame] | 475 | |
Thomas Gleixner | a40f262 | 2009-07-07 13:00:31 +0200 | [diff] [blame] | 476 | /** |
| 477 | * ktime_get_real - get the real (wall-) time in ktime_t format |
| 478 | * |
| 479 | * returns the time in ktime_t format |
| 480 | */ |
| 481 | ktime_t ktime_get_real(void) |
| 482 | { |
| 483 | struct timespec now; |
| 484 | |
| 485 | getnstimeofday(&now); |
| 486 | |
| 487 | return timespec_to_ktime(now); |
| 488 | } |
| 489 | EXPORT_SYMBOL_GPL(ktime_get_real); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 490 | |
| 491 | /** |
John Stultz | 2d42244 | 2008-08-20 16:37:30 -0700 | [diff] [blame] | 492 | * getrawmonotonic - Returns the raw monotonic time in a timespec |
| 493 | * @ts: pointer to the timespec to be set |
| 494 | * |
| 495 | * Returns the raw monotonic time (completely un-modified by ntp) |
| 496 | */ |
| 497 | void getrawmonotonic(struct timespec *ts) |
| 498 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 499 | struct timekeeper *tk = &timekeeper; |
John Stultz | 2d42244 | 2008-08-20 16:37:30 -0700 | [diff] [blame] | 500 | unsigned long seq; |
| 501 | s64 nsecs; |
John Stultz | 2d42244 | 2008-08-20 16:37:30 -0700 | [diff] [blame] | 502 | |
| 503 | do { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 504 | seq = read_seqbegin(&tk->lock); |
| 505 | nsecs = timekeeping_get_ns_raw(tk); |
| 506 | *ts = tk->raw_time; |
John Stultz | 2d42244 | 2008-08-20 16:37:30 -0700 | [diff] [blame] | 507 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 508 | } while (read_seqretry(&tk->lock, seq)); |
John Stultz | 2d42244 | 2008-08-20 16:37:30 -0700 | [diff] [blame] | 509 | |
| 510 | timespec_add_ns(ts, nsecs); |
| 511 | } |
| 512 | EXPORT_SYMBOL(getrawmonotonic); |
| 513 | |
John Stultz | 2d42244 | 2008-08-20 16:37:30 -0700 | [diff] [blame] | 514 | /** |
Li Zefan | cf4fc6c | 2008-02-08 04:19:24 -0800 | [diff] [blame] | 515 | * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 516 | */ |
Li Zefan | cf4fc6c | 2008-02-08 04:19:24 -0800 | [diff] [blame] | 517 | int timekeeping_valid_for_hres(void) |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 518 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 519 | struct timekeeper *tk = &timekeeper; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 520 | unsigned long seq; |
| 521 | int ret; |
| 522 | |
| 523 | do { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 524 | seq = read_seqbegin(&tk->lock); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 525 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 526 | ret = tk->clock->flags & CLOCK_SOURCE_VALID_FOR_HRES; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 527 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 528 | } while (read_seqretry(&tk->lock, seq)); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 529 | |
| 530 | return ret; |
| 531 | } |
| 532 | |
| 533 | /** |
Jon Hunter | 9896246 | 2009-08-18 12:45:10 -0500 | [diff] [blame] | 534 | * timekeeping_max_deferment - Returns max time the clocksource can be deferred |
Jon Hunter | 9896246 | 2009-08-18 12:45:10 -0500 | [diff] [blame] | 535 | */ |
| 536 | u64 timekeeping_max_deferment(void) |
| 537 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 538 | struct timekeeper *tk = &timekeeper; |
John Stultz | 70471f2 | 2011-11-14 12:48:10 -0800 | [diff] [blame] | 539 | unsigned long seq; |
| 540 | u64 ret; |
John Stultz | 42e71e8 | 2012-07-13 01:21:51 -0400 | [diff] [blame] | 541 | |
John Stultz | 70471f2 | 2011-11-14 12:48:10 -0800 | [diff] [blame] | 542 | do { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 543 | seq = read_seqbegin(&tk->lock); |
John Stultz | 70471f2 | 2011-11-14 12:48:10 -0800 | [diff] [blame] | 544 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 545 | ret = tk->clock->max_idle_ns; |
John Stultz | 70471f2 | 2011-11-14 12:48:10 -0800 | [diff] [blame] | 546 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 547 | } while (read_seqretry(&tk->lock, seq)); |
John Stultz | 70471f2 | 2011-11-14 12:48:10 -0800 | [diff] [blame] | 548 | |
| 549 | return ret; |
Jon Hunter | 9896246 | 2009-08-18 12:45:10 -0500 | [diff] [blame] | 550 | } |
| 551 | |
| 552 | /** |
Martin Schwidefsky | d4f587c | 2009-08-14 15:47:31 +0200 | [diff] [blame] | 553 | * read_persistent_clock - Return time from the persistent clock. |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 554 | * |
| 555 | * Weak dummy function for arches that do not yet support it. |
Martin Schwidefsky | d4f587c | 2009-08-14 15:47:31 +0200 | [diff] [blame] | 556 | * Reads the time from the battery backed persistent clock. |
| 557 | * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported. |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 558 | * |
| 559 | * XXX - Do be sure to remove it once all arches implement it. |
| 560 | */ |
Martin Schwidefsky | d4f587c | 2009-08-14 15:47:31 +0200 | [diff] [blame] | 561 | void __attribute__((weak)) read_persistent_clock(struct timespec *ts) |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 562 | { |
Martin Schwidefsky | d4f587c | 2009-08-14 15:47:31 +0200 | [diff] [blame] | 563 | ts->tv_sec = 0; |
| 564 | ts->tv_nsec = 0; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 565 | } |
| 566 | |
Martin Schwidefsky | 23970e3 | 2009-08-14 15:47:32 +0200 | [diff] [blame] | 567 | /** |
| 568 | * read_boot_clock - Return time of the system start. |
| 569 | * |
| 570 | * Weak dummy function for arches that do not yet support it. |
| 571 | * Function to read the exact time the system has been started. |
| 572 | * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported. |
| 573 | * |
| 574 | * XXX - Do be sure to remove it once all arches implement it. |
| 575 | */ |
| 576 | void __attribute__((weak)) read_boot_clock(struct timespec *ts) |
| 577 | { |
| 578 | ts->tv_sec = 0; |
| 579 | ts->tv_nsec = 0; |
| 580 | } |
| 581 | |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 582 | /* |
| 583 | * timekeeping_init - Initializes the clocksource and common timekeeping values |
| 584 | */ |
| 585 | void __init timekeeping_init(void) |
| 586 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 587 | struct timekeeper *tk = &timekeeper; |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 588 | struct clocksource *clock; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 589 | unsigned long flags; |
John Stultz | 6d0ef90 | 2012-07-27 14:48:12 -0400 | [diff] [blame] | 590 | struct timespec now, boot, tmp; |
Martin Schwidefsky | d4f587c | 2009-08-14 15:47:31 +0200 | [diff] [blame] | 591 | |
| 592 | read_persistent_clock(&now); |
John Stultz | cee5848 | 2012-08-31 13:30:06 -0400 | [diff] [blame] | 593 | if (!timespec_valid_strict(&now)) { |
John Stultz | 4e8b145 | 2012-08-08 15:36:20 -0400 | [diff] [blame] | 594 | pr_warn("WARNING: Persistent clock returned invalid value!\n" |
| 595 | " Check your CMOS/BIOS settings.\n"); |
| 596 | now.tv_sec = 0; |
| 597 | now.tv_nsec = 0; |
| 598 | } |
| 599 | |
Martin Schwidefsky | 23970e3 | 2009-08-14 15:47:32 +0200 | [diff] [blame] | 600 | read_boot_clock(&boot); |
John Stultz | cee5848 | 2012-08-31 13:30:06 -0400 | [diff] [blame] | 601 | if (!timespec_valid_strict(&boot)) { |
John Stultz | 4e8b145 | 2012-08-08 15:36:20 -0400 | [diff] [blame] | 602 | pr_warn("WARNING: Boot clock returned invalid value!\n" |
| 603 | " Check your CMOS/BIOS settings.\n"); |
| 604 | boot.tv_sec = 0; |
| 605 | boot.tv_nsec = 0; |
| 606 | } |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 607 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 608 | seqlock_init(&tk->lock); |
John Stultz | 70471f2 | 2011-11-14 12:48:10 -0800 | [diff] [blame] | 609 | |
Roman Zippel | 7dffa3c | 2008-05-01 04:34:41 -0700 | [diff] [blame] | 610 | ntp_init(); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 611 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 612 | write_seqlock_irqsave(&tk->lock, flags); |
Martin Schwidefsky | f1b8274 | 2009-08-14 15:47:21 +0200 | [diff] [blame] | 613 | clock = clocksource_default_clock(); |
Martin Schwidefsky | a0f7d48 | 2009-08-14 15:47:19 +0200 | [diff] [blame] | 614 | if (clock->enable) |
| 615 | clock->enable(clock); |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 616 | tk_setup_internals(tk, clock); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 617 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 618 | tk_set_xtime(tk, &now); |
| 619 | tk->raw_time.tv_sec = 0; |
| 620 | tk->raw_time.tv_nsec = 0; |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 621 | if (boot.tv_sec == 0 && boot.tv_nsec == 0) |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 622 | boot = tk_xtime(tk); |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 623 | |
John Stultz | 6d0ef90 | 2012-07-27 14:48:12 -0400 | [diff] [blame] | 624 | set_normalized_timespec(&tmp, -boot.tv_sec, -boot.tv_nsec); |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 625 | tk_set_wall_to_mono(tk, tmp); |
John Stultz | 6d0ef90 | 2012-07-27 14:48:12 -0400 | [diff] [blame] | 626 | |
| 627 | tmp.tv_sec = 0; |
| 628 | tmp.tv_nsec = 0; |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 629 | tk_set_sleep_time(tk, tmp); |
John Stultz | 6d0ef90 | 2012-07-27 14:48:12 -0400 | [diff] [blame] | 630 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 631 | write_sequnlock_irqrestore(&tk->lock, flags); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 632 | } |
| 633 | |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 634 | /* time in seconds when suspend began */ |
Martin Schwidefsky | d4f587c | 2009-08-14 15:47:31 +0200 | [diff] [blame] | 635 | static struct timespec timekeeping_suspend_time; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 636 | |
| 637 | /** |
John Stultz | 304529b | 2011-04-01 14:32:09 -0700 | [diff] [blame] | 638 | * __timekeeping_inject_sleeptime - Internal function to add sleep interval |
| 639 | * @delta: pointer to a timespec delta value |
| 640 | * |
| 641 | * Takes a timespec offset measuring a suspend interval and properly |
| 642 | * adds the sleep offset to the timekeeping variables. |
| 643 | */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 644 | static void __timekeeping_inject_sleeptime(struct timekeeper *tk, |
| 645 | struct timespec *delta) |
John Stultz | 304529b | 2011-04-01 14:32:09 -0700 | [diff] [blame] | 646 | { |
John Stultz | cee5848 | 2012-08-31 13:30:06 -0400 | [diff] [blame] | 647 | if (!timespec_valid_strict(delta)) { |
John Stultz | cbaa515 | 2011-07-20 15:42:55 -0700 | [diff] [blame] | 648 | printk(KERN_WARNING "__timekeeping_inject_sleeptime: Invalid " |
John Stultz | cb5de2f8d | 2011-06-01 18:18:09 -0700 | [diff] [blame] | 649 | "sleep delta value!\n"); |
| 650 | return; |
| 651 | } |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 652 | tk_xtime_add(tk, delta); |
John Stultz | 6d0ef90 | 2012-07-27 14:48:12 -0400 | [diff] [blame] | 653 | tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *delta)); |
| 654 | tk_set_sleep_time(tk, timespec_add(tk->total_sleep_time, *delta)); |
John Stultz | 304529b | 2011-04-01 14:32:09 -0700 | [diff] [blame] | 655 | } |
| 656 | |
John Stultz | 304529b | 2011-04-01 14:32:09 -0700 | [diff] [blame] | 657 | /** |
| 658 | * timekeeping_inject_sleeptime - Adds suspend interval to timeekeeping values |
| 659 | * @delta: pointer to a timespec delta value |
| 660 | * |
| 661 | * This hook is for architectures that cannot support read_persistent_clock |
| 662 | * because their RTC/persistent clock is only accessible when irqs are enabled. |
| 663 | * |
| 664 | * This function should only be called by rtc_resume(), and allows |
| 665 | * a suspend offset to be injected into the timekeeping values. |
| 666 | */ |
| 667 | void timekeeping_inject_sleeptime(struct timespec *delta) |
| 668 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 669 | struct timekeeper *tk = &timekeeper; |
John Stultz | 92c1d3e | 2011-11-14 14:05:44 -0800 | [diff] [blame] | 670 | unsigned long flags; |
John Stultz | 304529b | 2011-04-01 14:32:09 -0700 | [diff] [blame] | 671 | struct timespec ts; |
| 672 | |
| 673 | /* Make sure we don't set the clock twice */ |
| 674 | read_persistent_clock(&ts); |
| 675 | if (!(ts.tv_sec == 0 && ts.tv_nsec == 0)) |
| 676 | return; |
| 677 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 678 | write_seqlock_irqsave(&tk->lock, flags); |
John Stultz | 70471f2 | 2011-11-14 12:48:10 -0800 | [diff] [blame] | 679 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 680 | timekeeping_forward_now(tk); |
John Stultz | 304529b | 2011-04-01 14:32:09 -0700 | [diff] [blame] | 681 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 682 | __timekeeping_inject_sleeptime(tk, delta); |
John Stultz | 304529b | 2011-04-01 14:32:09 -0700 | [diff] [blame] | 683 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 684 | timekeeping_update(tk, true); |
John Stultz | 304529b | 2011-04-01 14:32:09 -0700 | [diff] [blame] | 685 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 686 | write_sequnlock_irqrestore(&tk->lock, flags); |
John Stultz | 304529b | 2011-04-01 14:32:09 -0700 | [diff] [blame] | 687 | |
| 688 | /* signal hrtimers about time change */ |
| 689 | clock_was_set(); |
| 690 | } |
| 691 | |
John Stultz | 304529b | 2011-04-01 14:32:09 -0700 | [diff] [blame] | 692 | /** |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 693 | * timekeeping_resume - Resumes the generic timekeeping subsystem. |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 694 | * |
| 695 | * This is for the generic clocksource timekeeping. |
| 696 | * xtime/wall_to_monotonic/jiffies/etc are |
| 697 | * still managed by arch specific suspend/resume code. |
| 698 | */ |
Rafael J. Wysocki | e1a85b2 | 2011-03-23 22:16:04 +0100 | [diff] [blame] | 699 | static void timekeeping_resume(void) |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 700 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 701 | struct timekeeper *tk = &timekeeper; |
John Stultz | 92c1d3e | 2011-11-14 14:05:44 -0800 | [diff] [blame] | 702 | unsigned long flags; |
Martin Schwidefsky | d4f587c | 2009-08-14 15:47:31 +0200 | [diff] [blame] | 703 | struct timespec ts; |
| 704 | |
| 705 | read_persistent_clock(&ts); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 706 | |
Rafael J. Wysocki | adc78e6 | 2012-08-06 01:40:41 +0200 | [diff] [blame] | 707 | clockevents_resume(); |
Thomas Gleixner | d10ff3f | 2007-05-14 11:10:02 +0200 | [diff] [blame] | 708 | clocksource_resume(); |
| 709 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 710 | write_seqlock_irqsave(&tk->lock, flags); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 711 | |
Martin Schwidefsky | d4f587c | 2009-08-14 15:47:31 +0200 | [diff] [blame] | 712 | if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) { |
| 713 | ts = timespec_sub(ts, timekeeping_suspend_time); |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 714 | __timekeeping_inject_sleeptime(tk, &ts); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 715 | } |
| 716 | /* re-base the last cycle value */ |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 717 | tk->clock->cycle_last = tk->clock->read(tk->clock); |
| 718 | tk->ntp_error = 0; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 719 | timekeeping_suspended = 0; |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 720 | timekeeping_update(tk, false); |
| 721 | write_sequnlock_irqrestore(&tk->lock, flags); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 722 | |
| 723 | touch_softlockup_watchdog(); |
| 724 | |
| 725 | clockevents_notify(CLOCK_EVT_NOTIFY_RESUME, NULL); |
| 726 | |
| 727 | /* Resume hrtimers */ |
Thomas Gleixner | b12a03c | 2011-05-02 16:48:57 +0200 | [diff] [blame] | 728 | hrtimers_resume(); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 729 | } |
| 730 | |
Rafael J. Wysocki | e1a85b2 | 2011-03-23 22:16:04 +0100 | [diff] [blame] | 731 | static int timekeeping_suspend(void) |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 732 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 733 | struct timekeeper *tk = &timekeeper; |
John Stultz | 92c1d3e | 2011-11-14 14:05:44 -0800 | [diff] [blame] | 734 | unsigned long flags; |
John Stultz | cb33217 | 2011-05-31 22:53:23 -0700 | [diff] [blame] | 735 | struct timespec delta, delta_delta; |
| 736 | static struct timespec old_delta; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 737 | |
Martin Schwidefsky | d4f587c | 2009-08-14 15:47:31 +0200 | [diff] [blame] | 738 | read_persistent_clock(&timekeeping_suspend_time); |
Thomas Gleixner | 3be9095 | 2007-09-16 15:36:43 +0200 | [diff] [blame] | 739 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 740 | write_seqlock_irqsave(&tk->lock, flags); |
| 741 | timekeeping_forward_now(tk); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 742 | timekeeping_suspended = 1; |
John Stultz | cb33217 | 2011-05-31 22:53:23 -0700 | [diff] [blame] | 743 | |
| 744 | /* |
| 745 | * To avoid drift caused by repeated suspend/resumes, |
| 746 | * which each can add ~1 second drift error, |
| 747 | * try to compensate so the difference in system time |
| 748 | * and persistent_clock time stays close to constant. |
| 749 | */ |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 750 | delta = timespec_sub(tk_xtime(tk), timekeeping_suspend_time); |
John Stultz | cb33217 | 2011-05-31 22:53:23 -0700 | [diff] [blame] | 751 | delta_delta = timespec_sub(delta, old_delta); |
| 752 | if (abs(delta_delta.tv_sec) >= 2) { |
| 753 | /* |
| 754 | * if delta_delta is too large, assume time correction |
| 755 | * has occured and set old_delta to the current delta. |
| 756 | */ |
| 757 | old_delta = delta; |
| 758 | } else { |
| 759 | /* Otherwise try to adjust old_system to compensate */ |
| 760 | timekeeping_suspend_time = |
| 761 | timespec_add(timekeeping_suspend_time, delta_delta); |
| 762 | } |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 763 | write_sequnlock_irqrestore(&tk->lock, flags); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 764 | |
| 765 | clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL); |
Magnus Damm | c54a42b | 2010-02-02 14:41:41 -0800 | [diff] [blame] | 766 | clocksource_suspend(); |
Rafael J. Wysocki | adc78e6 | 2012-08-06 01:40:41 +0200 | [diff] [blame] | 767 | clockevents_suspend(); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 768 | |
| 769 | return 0; |
| 770 | } |
| 771 | |
| 772 | /* sysfs resume/suspend bits for timekeeping */ |
Rafael J. Wysocki | e1a85b2 | 2011-03-23 22:16:04 +0100 | [diff] [blame] | 773 | static struct syscore_ops timekeeping_syscore_ops = { |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 774 | .resume = timekeeping_resume, |
| 775 | .suspend = timekeeping_suspend, |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 776 | }; |
| 777 | |
Rafael J. Wysocki | e1a85b2 | 2011-03-23 22:16:04 +0100 | [diff] [blame] | 778 | static int __init timekeeping_init_ops(void) |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 779 | { |
Rafael J. Wysocki | e1a85b2 | 2011-03-23 22:16:04 +0100 | [diff] [blame] | 780 | register_syscore_ops(&timekeeping_syscore_ops); |
| 781 | return 0; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 782 | } |
| 783 | |
Rafael J. Wysocki | e1a85b2 | 2011-03-23 22:16:04 +0100 | [diff] [blame] | 784 | device_initcall(timekeeping_init_ops); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 785 | |
| 786 | /* |
| 787 | * If the error is already larger, we look ahead even further |
| 788 | * to compensate for late or lost adjustments. |
| 789 | */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 790 | static __always_inline int timekeeping_bigadjust(struct timekeeper *tk, |
| 791 | s64 error, s64 *interval, |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 792 | s64 *offset) |
| 793 | { |
| 794 | s64 tick_error, i; |
| 795 | u32 look_ahead, adj; |
| 796 | s32 error2, mult; |
| 797 | |
| 798 | /* |
| 799 | * Use the current error value to determine how much to look ahead. |
| 800 | * The larger the error the slower we adjust for it to avoid problems |
| 801 | * with losing too many ticks, otherwise we would overadjust and |
| 802 | * produce an even larger error. The smaller the adjustment the |
| 803 | * faster we try to adjust for it, as lost ticks can do less harm |
Li Zefan | 3eb0567 | 2008-02-08 04:19:25 -0800 | [diff] [blame] | 804 | * here. This is tuned so that an error of about 1 msec is adjusted |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 805 | * within about 1 sec (or 2^20 nsec in 2^SHIFT_HZ ticks). |
| 806 | */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 807 | error2 = tk->ntp_error >> (NTP_SCALE_SHIFT + 22 - 2 * SHIFT_HZ); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 808 | error2 = abs(error2); |
| 809 | for (look_ahead = 0; error2 > 0; look_ahead++) |
| 810 | error2 >>= 2; |
| 811 | |
| 812 | /* |
| 813 | * Now calculate the error in (1 << look_ahead) ticks, but first |
| 814 | * remove the single look ahead already included in the error. |
| 815 | */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 816 | tick_error = ntp_tick_length() >> (tk->ntp_error_shift + 1); |
| 817 | tick_error -= tk->xtime_interval >> 1; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 818 | error = ((error - tick_error) >> look_ahead) + tick_error; |
| 819 | |
| 820 | /* Finally calculate the adjustment shift value. */ |
| 821 | i = *interval; |
| 822 | mult = 1; |
| 823 | if (error < 0) { |
| 824 | error = -error; |
| 825 | *interval = -*interval; |
| 826 | *offset = -*offset; |
| 827 | mult = -1; |
| 828 | } |
| 829 | for (adj = 0; error > i; adj++) |
| 830 | error >>= 1; |
| 831 | |
| 832 | *interval <<= adj; |
| 833 | *offset <<= adj; |
| 834 | return mult << adj; |
| 835 | } |
| 836 | |
| 837 | /* |
| 838 | * Adjust the multiplier to reduce the error value, |
| 839 | * this is optimized for the most common adjustments of -1,0,1, |
| 840 | * for other values we can do a bit more work. |
| 841 | */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 842 | static void timekeeping_adjust(struct timekeeper *tk, s64 offset) |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 843 | { |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 844 | s64 error, interval = tk->cycle_interval; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 845 | int adj; |
| 846 | |
John Stultz | c2bc111 | 2011-10-27 18:12:42 -0700 | [diff] [blame] | 847 | /* |
Jim Cromie | 88b28ad | 2012-03-14 21:28:56 -0600 | [diff] [blame] | 848 | * The point of this is to check if the error is greater than half |
John Stultz | c2bc111 | 2011-10-27 18:12:42 -0700 | [diff] [blame] | 849 | * an interval. |
| 850 | * |
| 851 | * First we shift it down from NTP_SHIFT to clocksource->shifted nsecs. |
| 852 | * |
| 853 | * Note we subtract one in the shift, so that error is really error*2. |
John Stultz | 3f86f28 | 2011-10-27 17:41:17 -0700 | [diff] [blame] | 854 | * This "saves" dividing(shifting) interval twice, but keeps the |
| 855 | * (error > interval) comparison as still measuring if error is |
Jim Cromie | 88b28ad | 2012-03-14 21:28:56 -0600 | [diff] [blame] | 856 | * larger than half an interval. |
John Stultz | c2bc111 | 2011-10-27 18:12:42 -0700 | [diff] [blame] | 857 | * |
John Stultz | 3f86f28 | 2011-10-27 17:41:17 -0700 | [diff] [blame] | 858 | * Note: It does not "save" on aggravation when reading the code. |
John Stultz | c2bc111 | 2011-10-27 18:12:42 -0700 | [diff] [blame] | 859 | */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 860 | error = tk->ntp_error >> (tk->ntp_error_shift - 1); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 861 | if (error > interval) { |
John Stultz | c2bc111 | 2011-10-27 18:12:42 -0700 | [diff] [blame] | 862 | /* |
| 863 | * We now divide error by 4(via shift), which checks if |
Jim Cromie | 88b28ad | 2012-03-14 21:28:56 -0600 | [diff] [blame] | 864 | * the error is greater than twice the interval. |
John Stultz | c2bc111 | 2011-10-27 18:12:42 -0700 | [diff] [blame] | 865 | * If it is greater, we need a bigadjust, if its smaller, |
| 866 | * we can adjust by 1. |
| 867 | */ |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 868 | error >>= 2; |
John Stultz | c2bc111 | 2011-10-27 18:12:42 -0700 | [diff] [blame] | 869 | /* |
| 870 | * XXX - In update_wall_time, we round up to the next |
| 871 | * nanosecond, and store the amount rounded up into |
| 872 | * the error. This causes the likely below to be unlikely. |
| 873 | * |
John Stultz | 3f86f28 | 2011-10-27 17:41:17 -0700 | [diff] [blame] | 874 | * The proper fix is to avoid rounding up by using |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 875 | * the high precision tk->xtime_nsec instead of |
John Stultz | c2bc111 | 2011-10-27 18:12:42 -0700 | [diff] [blame] | 876 | * xtime.tv_nsec everywhere. Fixing this will take some |
| 877 | * time. |
| 878 | */ |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 879 | if (likely(error <= interval)) |
| 880 | adj = 1; |
| 881 | else |
Ingo Molnar | 1d17d17 | 2012-08-04 21:21:14 +0200 | [diff] [blame] | 882 | adj = timekeeping_bigadjust(tk, error, &interval, &offset); |
| 883 | } else { |
| 884 | if (error < -interval) { |
| 885 | /* See comment above, this is just switched for the negative */ |
| 886 | error >>= 2; |
| 887 | if (likely(error >= -interval)) { |
| 888 | adj = -1; |
| 889 | interval = -interval; |
| 890 | offset = -offset; |
| 891 | } else { |
| 892 | adj = timekeeping_bigadjust(tk, error, &interval, &offset); |
| 893 | } |
| 894 | } else { |
| 895 | goto out_adjust; |
| 896 | } |
| 897 | } |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 898 | |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 899 | if (unlikely(tk->clock->maxadj && |
| 900 | (tk->mult + adj > tk->clock->mult + tk->clock->maxadj))) { |
John Stultz | e919cfd | 2012-03-22 19:14:46 -0700 | [diff] [blame] | 901 | printk_once(KERN_WARNING |
| 902 | "Adjusting %s more than 11%% (%ld vs %ld)\n", |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 903 | tk->clock->name, (long)tk->mult + adj, |
| 904 | (long)tk->clock->mult + tk->clock->maxadj); |
John Stultz | e919cfd | 2012-03-22 19:14:46 -0700 | [diff] [blame] | 905 | } |
John Stultz | c2bc111 | 2011-10-27 18:12:42 -0700 | [diff] [blame] | 906 | /* |
| 907 | * So the following can be confusing. |
| 908 | * |
| 909 | * To keep things simple, lets assume adj == 1 for now. |
| 910 | * |
| 911 | * When adj != 1, remember that the interval and offset values |
| 912 | * have been appropriately scaled so the math is the same. |
| 913 | * |
| 914 | * The basic idea here is that we're increasing the multiplier |
| 915 | * by one, this causes the xtime_interval to be incremented by |
| 916 | * one cycle_interval. This is because: |
| 917 | * xtime_interval = cycle_interval * mult |
| 918 | * So if mult is being incremented by one: |
| 919 | * xtime_interval = cycle_interval * (mult + 1) |
| 920 | * Its the same as: |
| 921 | * xtime_interval = (cycle_interval * mult) + cycle_interval |
| 922 | * Which can be shortened to: |
| 923 | * xtime_interval += cycle_interval |
| 924 | * |
| 925 | * So offset stores the non-accumulated cycles. Thus the current |
| 926 | * time (in shifted nanoseconds) is: |
| 927 | * now = (offset * adj) + xtime_nsec |
| 928 | * Now, even though we're adjusting the clock frequency, we have |
| 929 | * to keep time consistent. In other words, we can't jump back |
| 930 | * in time, and we also want to avoid jumping forward in time. |
| 931 | * |
| 932 | * So given the same offset value, we need the time to be the same |
| 933 | * both before and after the freq adjustment. |
| 934 | * now = (offset * adj_1) + xtime_nsec_1 |
| 935 | * now = (offset * adj_2) + xtime_nsec_2 |
| 936 | * So: |
| 937 | * (offset * adj_1) + xtime_nsec_1 = |
| 938 | * (offset * adj_2) + xtime_nsec_2 |
| 939 | * And we know: |
| 940 | * adj_2 = adj_1 + 1 |
| 941 | * So: |
| 942 | * (offset * adj_1) + xtime_nsec_1 = |
| 943 | * (offset * (adj_1+1)) + xtime_nsec_2 |
| 944 | * (offset * adj_1) + xtime_nsec_1 = |
| 945 | * (offset * adj_1) + offset + xtime_nsec_2 |
| 946 | * Canceling the sides: |
| 947 | * xtime_nsec_1 = offset + xtime_nsec_2 |
| 948 | * Which gives us: |
| 949 | * xtime_nsec_2 = xtime_nsec_1 - offset |
| 950 | * Which simplfies to: |
| 951 | * xtime_nsec -= offset |
| 952 | * |
| 953 | * XXX - TODO: Doc ntp_error calculation. |
| 954 | */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 955 | tk->mult += adj; |
| 956 | tk->xtime_interval += interval; |
| 957 | tk->xtime_nsec -= offset; |
| 958 | tk->ntp_error -= (interval - offset) << tk->ntp_error_shift; |
John Stultz | 2a8c088 | 2012-07-13 01:21:56 -0400 | [diff] [blame] | 959 | |
Ingo Molnar | 1d17d17 | 2012-08-04 21:21:14 +0200 | [diff] [blame] | 960 | out_adjust: |
John Stultz | 2a8c088 | 2012-07-13 01:21:56 -0400 | [diff] [blame] | 961 | /* |
| 962 | * It may be possible that when we entered this function, xtime_nsec |
| 963 | * was very small. Further, if we're slightly speeding the clocksource |
| 964 | * in the code above, its possible the required corrective factor to |
| 965 | * xtime_nsec could cause it to underflow. |
| 966 | * |
| 967 | * Now, since we already accumulated the second, cannot simply roll |
| 968 | * the accumulated second back, since the NTP subsystem has been |
| 969 | * notified via second_overflow. So instead we push xtime_nsec forward |
| 970 | * by the amount we underflowed, and add that amount into the error. |
| 971 | * |
| 972 | * We'll correct this error next time through this function, when |
| 973 | * xtime_nsec is not as small. |
| 974 | */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 975 | if (unlikely((s64)tk->xtime_nsec < 0)) { |
| 976 | s64 neg = -(s64)tk->xtime_nsec; |
| 977 | tk->xtime_nsec = 0; |
| 978 | tk->ntp_error += neg << tk->ntp_error_shift; |
John Stultz | 2a8c088 | 2012-07-13 01:21:56 -0400 | [diff] [blame] | 979 | } |
| 980 | |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 981 | } |
| 982 | |
| 983 | /** |
John Stultz | 1f4f948 | 2012-07-13 01:21:54 -0400 | [diff] [blame] | 984 | * accumulate_nsecs_to_secs - Accumulates nsecs into secs |
| 985 | * |
| 986 | * Helper function that accumulates a the nsecs greater then a second |
| 987 | * from the xtime_nsec field to the xtime_secs field. |
| 988 | * It also calls into the NTP code to handle leapsecond processing. |
| 989 | * |
| 990 | */ |
| 991 | static inline void accumulate_nsecs_to_secs(struct timekeeper *tk) |
| 992 | { |
| 993 | u64 nsecps = (u64)NSEC_PER_SEC << tk->shift; |
| 994 | |
| 995 | while (tk->xtime_nsec >= nsecps) { |
| 996 | int leap; |
| 997 | |
| 998 | tk->xtime_nsec -= nsecps; |
| 999 | tk->xtime_sec++; |
| 1000 | |
| 1001 | /* Figure out if its a leap sec and apply if needed */ |
| 1002 | leap = second_overflow(tk->xtime_sec); |
John Stultz | 6d0ef90 | 2012-07-27 14:48:12 -0400 | [diff] [blame] | 1003 | if (unlikely(leap)) { |
| 1004 | struct timespec ts; |
John Stultz | 1f4f948 | 2012-07-13 01:21:54 -0400 | [diff] [blame] | 1005 | |
John Stultz | 6d0ef90 | 2012-07-27 14:48:12 -0400 | [diff] [blame] | 1006 | tk->xtime_sec += leap; |
| 1007 | |
| 1008 | ts.tv_sec = leap; |
| 1009 | ts.tv_nsec = 0; |
| 1010 | tk_set_wall_to_mono(tk, |
| 1011 | timespec_sub(tk->wall_to_monotonic, ts)); |
| 1012 | |
| 1013 | clock_was_set_delayed(); |
| 1014 | } |
John Stultz | 1f4f948 | 2012-07-13 01:21:54 -0400 | [diff] [blame] | 1015 | } |
| 1016 | } |
| 1017 | |
John Stultz | 1f4f948 | 2012-07-13 01:21:54 -0400 | [diff] [blame] | 1018 | /** |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1019 | * logarithmic_accumulation - shifted accumulation of cycles |
| 1020 | * |
| 1021 | * This functions accumulates a shifted interval of cycles into |
| 1022 | * into a shifted interval nanoseconds. Allows for O(log) accumulation |
| 1023 | * loop. |
| 1024 | * |
| 1025 | * Returns the unconsumed cycles. |
| 1026 | */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 1027 | static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset, |
| 1028 | u32 shift) |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1029 | { |
Jason Wessel | deda2e8 | 2010-08-09 14:20:09 -0700 | [diff] [blame] | 1030 | u64 raw_nsecs; |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1031 | |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 1032 | /* If the offset is smaller then a shifted interval, do nothing */ |
| 1033 | if (offset < tk->cycle_interval<<shift) |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1034 | return offset; |
| 1035 | |
| 1036 | /* Accumulate one shifted interval */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 1037 | offset -= tk->cycle_interval << shift; |
| 1038 | tk->clock->cycle_last += tk->cycle_interval << shift; |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1039 | |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 1040 | tk->xtime_nsec += tk->xtime_interval << shift; |
| 1041 | accumulate_nsecs_to_secs(tk); |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1042 | |
Jason Wessel | deda2e8 | 2010-08-09 14:20:09 -0700 | [diff] [blame] | 1043 | /* Accumulate raw time */ |
Dan Carpenter | 5b3900c | 2012-10-09 10:18:23 +0300 | [diff] [blame] | 1044 | raw_nsecs = (u64)tk->raw_interval << shift; |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 1045 | raw_nsecs += tk->raw_time.tv_nsec; |
John Stultz | c7dcf87 | 2010-08-13 11:30:58 -0700 | [diff] [blame] | 1046 | if (raw_nsecs >= NSEC_PER_SEC) { |
| 1047 | u64 raw_secs = raw_nsecs; |
| 1048 | raw_nsecs = do_div(raw_secs, NSEC_PER_SEC); |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 1049 | tk->raw_time.tv_sec += raw_secs; |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1050 | } |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 1051 | tk->raw_time.tv_nsec = raw_nsecs; |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1052 | |
| 1053 | /* Accumulate error between NTP and clock interval */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 1054 | tk->ntp_error += ntp_tick_length() << shift; |
| 1055 | tk->ntp_error -= (tk->xtime_interval + tk->xtime_remainder) << |
| 1056 | (tk->ntp_error_shift + shift); |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1057 | |
| 1058 | return offset; |
| 1059 | } |
| 1060 | |
John Stultz | 92bb1fc | 2012-09-04 15:38:12 -0400 | [diff] [blame] | 1061 | #ifdef CONFIG_GENERIC_TIME_VSYSCALL_OLD |
| 1062 | static inline void old_vsyscall_fixup(struct timekeeper *tk) |
| 1063 | { |
| 1064 | s64 remainder; |
| 1065 | |
| 1066 | /* |
| 1067 | * Store only full nanoseconds into xtime_nsec after rounding |
| 1068 | * it up and add the remainder to the error difference. |
| 1069 | * XXX - This is necessary to avoid small 1ns inconsistnecies caused |
| 1070 | * by truncating the remainder in vsyscalls. However, it causes |
| 1071 | * additional work to be done in timekeeping_adjust(). Once |
| 1072 | * the vsyscall implementations are converted to use xtime_nsec |
| 1073 | * (shifted nanoseconds), and CONFIG_GENERIC_TIME_VSYSCALL_OLD |
| 1074 | * users are removed, this can be killed. |
| 1075 | */ |
| 1076 | remainder = tk->xtime_nsec & ((1ULL << tk->shift) - 1); |
| 1077 | tk->xtime_nsec -= remainder; |
| 1078 | tk->xtime_nsec += 1ULL << tk->shift; |
| 1079 | tk->ntp_error += remainder << tk->ntp_error_shift; |
| 1080 | |
| 1081 | } |
| 1082 | #else |
| 1083 | #define old_vsyscall_fixup(tk) |
| 1084 | #endif |
| 1085 | |
| 1086 | |
| 1087 | |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 1088 | /** |
| 1089 | * update_wall_time - Uses the current clocksource to increment the wall time |
| 1090 | * |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 1091 | */ |
Torben Hohn | 871cf1e | 2011-01-27 15:58:55 +0100 | [diff] [blame] | 1092 | static void update_wall_time(void) |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 1093 | { |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 1094 | struct clocksource *clock; |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1095 | struct timekeeper *tk = &timekeeper; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 1096 | cycle_t offset; |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1097 | int shift = 0, maxshift; |
John Stultz | 70471f2 | 2011-11-14 12:48:10 -0800 | [diff] [blame] | 1098 | unsigned long flags; |
| 1099 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1100 | write_seqlock_irqsave(&tk->lock, flags); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 1101 | |
| 1102 | /* Make sure we're fully resumed: */ |
| 1103 | if (unlikely(timekeeping_suspended)) |
John Stultz | 70471f2 | 2011-11-14 12:48:10 -0800 | [diff] [blame] | 1104 | goto out; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 1105 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1106 | clock = tk->clock; |
John Stultz | 592913e | 2010-07-13 17:56:20 -0700 | [diff] [blame] | 1107 | |
| 1108 | #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1109 | offset = tk->cycle_interval; |
John Stultz | 592913e | 2010-07-13 17:56:20 -0700 | [diff] [blame] | 1110 | #else |
| 1111 | offset = (clock->read(clock) - clock->cycle_last) & clock->mask; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 1112 | #endif |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 1113 | |
John Stultz | bf2ac31 | 2012-08-21 20:30:49 -0400 | [diff] [blame] | 1114 | /* Check if there's really nothing to do */ |
| 1115 | if (offset < tk->cycle_interval) |
| 1116 | goto out; |
| 1117 | |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1118 | /* |
| 1119 | * With NO_HZ we may have to accumulate many cycle_intervals |
| 1120 | * (think "ticks") worth of time at once. To do this efficiently, |
| 1121 | * we calculate the largest doubling multiple of cycle_intervals |
Jim Cromie | 88b28ad | 2012-03-14 21:28:56 -0600 | [diff] [blame] | 1122 | * that is smaller than the offset. We then accumulate that |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1123 | * chunk in one go, and then try to consume the next smaller |
| 1124 | * doubled multiple. |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 1125 | */ |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1126 | shift = ilog2(offset) - ilog2(tk->cycle_interval); |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1127 | shift = max(0, shift); |
Jim Cromie | 88b28ad | 2012-03-14 21:28:56 -0600 | [diff] [blame] | 1128 | /* Bound shift to one less than what overflows tick_length */ |
John Stultz | ea7cf49 | 2011-11-14 13:18:07 -0800 | [diff] [blame] | 1129 | maxshift = (64 - (ilog2(ntp_tick_length())+1)) - 1; |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1130 | shift = min(shift, maxshift); |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1131 | while (offset >= tk->cycle_interval) { |
| 1132 | offset = logarithmic_accumulation(tk, offset, shift); |
| 1133 | if (offset < tk->cycle_interval<<shift) |
John Stultz | 830ec04 | 2010-03-18 14:47:30 -0700 | [diff] [blame] | 1134 | shift--; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 1135 | } |
| 1136 | |
| 1137 | /* correct the clock when NTP error is too big */ |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1138 | timekeeping_adjust(tk, offset); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 1139 | |
John Stultz | 6a867a3 | 2010-04-06 14:30:51 -0700 | [diff] [blame] | 1140 | /* |
John Stultz | 92bb1fc | 2012-09-04 15:38:12 -0400 | [diff] [blame] | 1141 | * XXX This can be killed once everyone converts |
| 1142 | * to the new update_vsyscall. |
| 1143 | */ |
| 1144 | old_vsyscall_fixup(tk); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 1145 | |
John Stultz | 6a867a3 | 2010-04-06 14:30:51 -0700 | [diff] [blame] | 1146 | /* |
| 1147 | * Finally, make sure that after the rounding |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 1148 | * xtime_nsec isn't larger than NSEC_PER_SEC |
John Stultz | 6a867a3 | 2010-04-06 14:30:51 -0700 | [diff] [blame] | 1149 | */ |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1150 | accumulate_nsecs_to_secs(tk); |
Linus Torvalds | 83f57a1 | 2009-12-22 14:10:37 -0800 | [diff] [blame] | 1151 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1152 | timekeeping_update(tk, false); |
John Stultz | 70471f2 | 2011-11-14 12:48:10 -0800 | [diff] [blame] | 1153 | |
| 1154 | out: |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1155 | write_sequnlock_irqrestore(&tk->lock, flags); |
John Stultz | 70471f2 | 2011-11-14 12:48:10 -0800 | [diff] [blame] | 1156 | |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 1157 | } |
Tomas Janousek | 7c3f1a5 | 2007-07-15 23:39:41 -0700 | [diff] [blame] | 1158 | |
| 1159 | /** |
| 1160 | * getboottime - Return the real time of system boot. |
| 1161 | * @ts: pointer to the timespec to be set |
| 1162 | * |
John Stultz | abb3a4e | 2011-02-14 17:52:09 -0800 | [diff] [blame] | 1163 | * Returns the wall-time of boot in a timespec. |
Tomas Janousek | 7c3f1a5 | 2007-07-15 23:39:41 -0700 | [diff] [blame] | 1164 | * |
| 1165 | * This is based on the wall_to_monotonic offset and the total suspend |
| 1166 | * time. Calls to settimeofday will affect the value returned (which |
| 1167 | * basically means that however wrong your real time clock is at boot time, |
| 1168 | * you get the right time here). |
| 1169 | */ |
| 1170 | void getboottime(struct timespec *ts) |
| 1171 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1172 | struct timekeeper *tk = &timekeeper; |
Hiroshi Shimamoto | 36d4748 | 2009-08-25 15:08:30 +0900 | [diff] [blame] | 1173 | struct timespec boottime = { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1174 | .tv_sec = tk->wall_to_monotonic.tv_sec + |
| 1175 | tk->total_sleep_time.tv_sec, |
| 1176 | .tv_nsec = tk->wall_to_monotonic.tv_nsec + |
| 1177 | tk->total_sleep_time.tv_nsec |
Hiroshi Shimamoto | 36d4748 | 2009-08-25 15:08:30 +0900 | [diff] [blame] | 1178 | }; |
Martin Schwidefsky | d4f587c | 2009-08-14 15:47:31 +0200 | [diff] [blame] | 1179 | |
Martin Schwidefsky | d4f587c | 2009-08-14 15:47:31 +0200 | [diff] [blame] | 1180 | set_normalized_timespec(ts, -boottime.tv_sec, -boottime.tv_nsec); |
Tomas Janousek | 7c3f1a5 | 2007-07-15 23:39:41 -0700 | [diff] [blame] | 1181 | } |
Jason Wang | c93d89f | 2010-01-27 19:13:40 +0800 | [diff] [blame] | 1182 | EXPORT_SYMBOL_GPL(getboottime); |
Tomas Janousek | 7c3f1a5 | 2007-07-15 23:39:41 -0700 | [diff] [blame] | 1183 | |
John Stultz | abb3a4e | 2011-02-14 17:52:09 -0800 | [diff] [blame] | 1184 | /** |
| 1185 | * get_monotonic_boottime - Returns monotonic time since boot |
| 1186 | * @ts: pointer to the timespec to be set |
| 1187 | * |
| 1188 | * Returns the monotonic time since boot in a timespec. |
| 1189 | * |
| 1190 | * This is similar to CLOCK_MONTONIC/ktime_get_ts, but also |
| 1191 | * includes the time spent in suspend. |
| 1192 | */ |
| 1193 | void get_monotonic_boottime(struct timespec *ts) |
| 1194 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1195 | struct timekeeper *tk = &timekeeper; |
John Stultz | abb3a4e | 2011-02-14 17:52:09 -0800 | [diff] [blame] | 1196 | struct timespec tomono, sleep; |
John Stultz | ec145ba | 2012-09-11 19:26:03 -0400 | [diff] [blame] | 1197 | s64 nsec; |
John Stultz | abb3a4e | 2011-02-14 17:52:09 -0800 | [diff] [blame] | 1198 | unsigned int seq; |
John Stultz | abb3a4e | 2011-02-14 17:52:09 -0800 | [diff] [blame] | 1199 | |
| 1200 | WARN_ON(timekeeping_suspended); |
| 1201 | |
| 1202 | do { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1203 | seq = read_seqbegin(&tk->lock); |
| 1204 | ts->tv_sec = tk->xtime_sec; |
John Stultz | ec145ba | 2012-09-11 19:26:03 -0400 | [diff] [blame] | 1205 | nsec = timekeeping_get_ns(tk); |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1206 | tomono = tk->wall_to_monotonic; |
| 1207 | sleep = tk->total_sleep_time; |
John Stultz | abb3a4e | 2011-02-14 17:52:09 -0800 | [diff] [blame] | 1208 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1209 | } while (read_seqretry(&tk->lock, seq)); |
John Stultz | abb3a4e | 2011-02-14 17:52:09 -0800 | [diff] [blame] | 1210 | |
John Stultz | ec145ba | 2012-09-11 19:26:03 -0400 | [diff] [blame] | 1211 | ts->tv_sec += tomono.tv_sec + sleep.tv_sec; |
| 1212 | ts->tv_nsec = 0; |
| 1213 | timespec_add_ns(ts, nsec + tomono.tv_nsec + sleep.tv_nsec); |
John Stultz | abb3a4e | 2011-02-14 17:52:09 -0800 | [diff] [blame] | 1214 | } |
| 1215 | EXPORT_SYMBOL_GPL(get_monotonic_boottime); |
| 1216 | |
| 1217 | /** |
| 1218 | * ktime_get_boottime - Returns monotonic time since boot in a ktime |
| 1219 | * |
| 1220 | * Returns the monotonic time since boot in a ktime |
| 1221 | * |
| 1222 | * This is similar to CLOCK_MONTONIC/ktime_get, but also |
| 1223 | * includes the time spent in suspend. |
| 1224 | */ |
| 1225 | ktime_t ktime_get_boottime(void) |
| 1226 | { |
| 1227 | struct timespec ts; |
| 1228 | |
| 1229 | get_monotonic_boottime(&ts); |
| 1230 | return timespec_to_ktime(ts); |
| 1231 | } |
| 1232 | EXPORT_SYMBOL_GPL(ktime_get_boottime); |
| 1233 | |
Tomas Janousek | 7c3f1a5 | 2007-07-15 23:39:41 -0700 | [diff] [blame] | 1234 | /** |
| 1235 | * monotonic_to_bootbased - Convert the monotonic time to boot based. |
| 1236 | * @ts: pointer to the timespec to be converted |
| 1237 | */ |
| 1238 | void monotonic_to_bootbased(struct timespec *ts) |
| 1239 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1240 | struct timekeeper *tk = &timekeeper; |
| 1241 | |
| 1242 | *ts = timespec_add(*ts, tk->total_sleep_time); |
Tomas Janousek | 7c3f1a5 | 2007-07-15 23:39:41 -0700 | [diff] [blame] | 1243 | } |
Jason Wang | c93d89f | 2010-01-27 19:13:40 +0800 | [diff] [blame] | 1244 | EXPORT_SYMBOL_GPL(monotonic_to_bootbased); |
john stultz | 2c6b47d | 2007-07-24 17:47:43 -0700 | [diff] [blame] | 1245 | |
john stultz | 17c38b7 | 2007-07-24 18:38:34 -0700 | [diff] [blame] | 1246 | unsigned long get_seconds(void) |
| 1247 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1248 | struct timekeeper *tk = &timekeeper; |
| 1249 | |
| 1250 | return tk->xtime_sec; |
john stultz | 17c38b7 | 2007-07-24 18:38:34 -0700 | [diff] [blame] | 1251 | } |
| 1252 | EXPORT_SYMBOL(get_seconds); |
| 1253 | |
john stultz | da15cfd | 2009-08-19 19:13:34 -0700 | [diff] [blame] | 1254 | struct timespec __current_kernel_time(void) |
| 1255 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1256 | struct timekeeper *tk = &timekeeper; |
| 1257 | |
| 1258 | return tk_xtime(tk); |
john stultz | da15cfd | 2009-08-19 19:13:34 -0700 | [diff] [blame] | 1259 | } |
john stultz | 17c38b7 | 2007-07-24 18:38:34 -0700 | [diff] [blame] | 1260 | |
john stultz | 2c6b47d | 2007-07-24 17:47:43 -0700 | [diff] [blame] | 1261 | struct timespec current_kernel_time(void) |
| 1262 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1263 | struct timekeeper *tk = &timekeeper; |
john stultz | 2c6b47d | 2007-07-24 17:47:43 -0700 | [diff] [blame] | 1264 | struct timespec now; |
| 1265 | unsigned long seq; |
| 1266 | |
| 1267 | do { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1268 | seq = read_seqbegin(&tk->lock); |
Linus Torvalds | 83f57a1 | 2009-12-22 14:10:37 -0800 | [diff] [blame] | 1269 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1270 | now = tk_xtime(tk); |
| 1271 | } while (read_seqretry(&tk->lock, seq)); |
john stultz | 2c6b47d | 2007-07-24 17:47:43 -0700 | [diff] [blame] | 1272 | |
| 1273 | return now; |
| 1274 | } |
john stultz | 2c6b47d | 2007-07-24 17:47:43 -0700 | [diff] [blame] | 1275 | EXPORT_SYMBOL(current_kernel_time); |
john stultz | da15cfd | 2009-08-19 19:13:34 -0700 | [diff] [blame] | 1276 | |
| 1277 | struct timespec get_monotonic_coarse(void) |
| 1278 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1279 | struct timekeeper *tk = &timekeeper; |
john stultz | da15cfd | 2009-08-19 19:13:34 -0700 | [diff] [blame] | 1280 | struct timespec now, mono; |
| 1281 | unsigned long seq; |
| 1282 | |
| 1283 | do { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1284 | seq = read_seqbegin(&tk->lock); |
Linus Torvalds | 83f57a1 | 2009-12-22 14:10:37 -0800 | [diff] [blame] | 1285 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1286 | now = tk_xtime(tk); |
| 1287 | mono = tk->wall_to_monotonic; |
| 1288 | } while (read_seqretry(&tk->lock, seq)); |
john stultz | da15cfd | 2009-08-19 19:13:34 -0700 | [diff] [blame] | 1289 | |
| 1290 | set_normalized_timespec(&now, now.tv_sec + mono.tv_sec, |
| 1291 | now.tv_nsec + mono.tv_nsec); |
| 1292 | return now; |
| 1293 | } |
Torben Hohn | 871cf1e | 2011-01-27 15:58:55 +0100 | [diff] [blame] | 1294 | |
| 1295 | /* |
John Stultz | d6ad418 | 2012-02-28 16:50:11 -0800 | [diff] [blame] | 1296 | * Must hold jiffies_lock |
Torben Hohn | 871cf1e | 2011-01-27 15:58:55 +0100 | [diff] [blame] | 1297 | */ |
| 1298 | void do_timer(unsigned long ticks) |
| 1299 | { |
| 1300 | jiffies_64 += ticks; |
| 1301 | update_wall_time(); |
| 1302 | calc_global_load(ticks); |
| 1303 | } |
Torben Hohn | 48cf76f7 | 2011-01-27 15:59:05 +0100 | [diff] [blame] | 1304 | |
| 1305 | /** |
John Stultz | 314ac37 | 2011-02-14 18:43:08 -0800 | [diff] [blame] | 1306 | * get_xtime_and_monotonic_and_sleep_offset() - get xtime, wall_to_monotonic, |
| 1307 | * and sleep offsets. |
Torben Hohn | 48cf76f7 | 2011-01-27 15:59:05 +0100 | [diff] [blame] | 1308 | * @xtim: pointer to timespec to be set with xtime |
| 1309 | * @wtom: pointer to timespec to be set with wall_to_monotonic |
John Stultz | 314ac37 | 2011-02-14 18:43:08 -0800 | [diff] [blame] | 1310 | * @sleep: pointer to timespec to be set with time in suspend |
Torben Hohn | 48cf76f7 | 2011-01-27 15:59:05 +0100 | [diff] [blame] | 1311 | */ |
John Stultz | 314ac37 | 2011-02-14 18:43:08 -0800 | [diff] [blame] | 1312 | void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim, |
| 1313 | struct timespec *wtom, struct timespec *sleep) |
Torben Hohn | 48cf76f7 | 2011-01-27 15:59:05 +0100 | [diff] [blame] | 1314 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1315 | struct timekeeper *tk = &timekeeper; |
Torben Hohn | 48cf76f7 | 2011-01-27 15:59:05 +0100 | [diff] [blame] | 1316 | unsigned long seq; |
| 1317 | |
| 1318 | do { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1319 | seq = read_seqbegin(&tk->lock); |
| 1320 | *xtim = tk_xtime(tk); |
| 1321 | *wtom = tk->wall_to_monotonic; |
| 1322 | *sleep = tk->total_sleep_time; |
| 1323 | } while (read_seqretry(&tk->lock, seq)); |
Torben Hohn | 48cf76f7 | 2011-01-27 15:59:05 +0100 | [diff] [blame] | 1324 | } |
Torben Hohn | f0af911a9 | 2011-01-27 15:59:10 +0100 | [diff] [blame] | 1325 | |
Thomas Gleixner | f6c06ab | 2012-07-10 18:43:24 -0400 | [diff] [blame] | 1326 | #ifdef CONFIG_HIGH_RES_TIMERS |
| 1327 | /** |
| 1328 | * ktime_get_update_offsets - hrtimer helper |
| 1329 | * @offs_real: pointer to storage for monotonic -> realtime offset |
| 1330 | * @offs_boot: pointer to storage for monotonic -> boottime offset |
| 1331 | * |
| 1332 | * Returns current monotonic time and updates the offsets |
| 1333 | * Called from hrtimer_interupt() or retrigger_next_event() |
| 1334 | */ |
| 1335 | ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot) |
| 1336 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1337 | struct timekeeper *tk = &timekeeper; |
Thomas Gleixner | f6c06ab | 2012-07-10 18:43:24 -0400 | [diff] [blame] | 1338 | ktime_t now; |
| 1339 | unsigned int seq; |
| 1340 | u64 secs, nsecs; |
| 1341 | |
| 1342 | do { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1343 | seq = read_seqbegin(&tk->lock); |
Thomas Gleixner | f6c06ab | 2012-07-10 18:43:24 -0400 | [diff] [blame] | 1344 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1345 | secs = tk->xtime_sec; |
| 1346 | nsecs = timekeeping_get_ns(tk); |
Thomas Gleixner | f6c06ab | 2012-07-10 18:43:24 -0400 | [diff] [blame] | 1347 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1348 | *offs_real = tk->offs_real; |
| 1349 | *offs_boot = tk->offs_boot; |
| 1350 | } while (read_seqretry(&tk->lock, seq)); |
Thomas Gleixner | f6c06ab | 2012-07-10 18:43:24 -0400 | [diff] [blame] | 1351 | |
| 1352 | now = ktime_add_ns(ktime_set(secs, 0), nsecs); |
| 1353 | now = ktime_sub(now, *offs_real); |
| 1354 | return now; |
| 1355 | } |
| 1356 | #endif |
| 1357 | |
Torben Hohn | f0af911a9 | 2011-01-27 15:59:10 +0100 | [diff] [blame] | 1358 | /** |
Thomas Gleixner | 99ee531 | 2011-04-27 14:16:42 +0200 | [diff] [blame] | 1359 | * ktime_get_monotonic_offset() - get wall_to_monotonic in ktime_t format |
| 1360 | */ |
| 1361 | ktime_t ktime_get_monotonic_offset(void) |
| 1362 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1363 | struct timekeeper *tk = &timekeeper; |
Thomas Gleixner | 99ee531 | 2011-04-27 14:16:42 +0200 | [diff] [blame] | 1364 | unsigned long seq; |
| 1365 | struct timespec wtom; |
| 1366 | |
| 1367 | do { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1368 | seq = read_seqbegin(&tk->lock); |
| 1369 | wtom = tk->wall_to_monotonic; |
| 1370 | } while (read_seqretry(&tk->lock, seq)); |
John Stultz | 70471f2 | 2011-11-14 12:48:10 -0800 | [diff] [blame] | 1371 | |
Thomas Gleixner | 99ee531 | 2011-04-27 14:16:42 +0200 | [diff] [blame] | 1372 | return timespec_to_ktime(wtom); |
| 1373 | } |
John Stultz | a80b83b | 2012-02-03 00:19:07 -0800 | [diff] [blame] | 1374 | EXPORT_SYMBOL_GPL(ktime_get_monotonic_offset); |
| 1375 | |
Thomas Gleixner | 99ee531 | 2011-04-27 14:16:42 +0200 | [diff] [blame] | 1376 | /** |
Torben Hohn | f0af911a9 | 2011-01-27 15:59:10 +0100 | [diff] [blame] | 1377 | * xtime_update() - advances the timekeeping infrastructure |
| 1378 | * @ticks: number of ticks, that have elapsed since the last call. |
| 1379 | * |
| 1380 | * Must be called with interrupts disabled. |
| 1381 | */ |
| 1382 | void xtime_update(unsigned long ticks) |
| 1383 | { |
John Stultz | d6ad418 | 2012-02-28 16:50:11 -0800 | [diff] [blame] | 1384 | write_seqlock(&jiffies_lock); |
Torben Hohn | f0af911a9 | 2011-01-27 15:59:10 +0100 | [diff] [blame] | 1385 | do_timer(ticks); |
John Stultz | d6ad418 | 2012-02-28 16:50:11 -0800 | [diff] [blame] | 1386 | write_sequnlock(&jiffies_lock); |
Torben Hohn | f0af911a9 | 2011-01-27 15:59:10 +0100 | [diff] [blame] | 1387 | } |