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 | /* |
| 29 | * This read-write spinlock protects us from races in SMP while |
| 30 | * playing with xtime. |
| 31 | */ |
| 32 | __cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock); |
| 33 | |
John Stultz | 8fcce54 | 2011-11-14 11:46:39 -0800 | [diff] [blame] | 34 | /* flag for if timekeeping is suspended */ |
| 35 | int __read_mostly timekeeping_suspended; |
| 36 | |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 37 | static inline void tk_normalize_xtime(struct timekeeper *tk) |
| 38 | { |
| 39 | while (tk->xtime_nsec >= ((u64)NSEC_PER_SEC << tk->shift)) { |
| 40 | tk->xtime_nsec -= (u64)NSEC_PER_SEC << tk->shift; |
| 41 | tk->xtime_sec++; |
| 42 | } |
| 43 | } |
John Stultz | 8fcce54 | 2011-11-14 11:46:39 -0800 | [diff] [blame] | 44 | |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 45 | static struct timespec tk_xtime(struct timekeeper *tk) |
| 46 | { |
| 47 | struct timespec ts; |
| 48 | |
| 49 | ts.tv_sec = tk->xtime_sec; |
| 50 | ts.tv_nsec = (long)(tk->xtime_nsec >> tk->shift); |
| 51 | return ts; |
| 52 | } |
| 53 | |
| 54 | static void tk_set_xtime(struct timekeeper *tk, const struct timespec *ts) |
| 55 | { |
| 56 | tk->xtime_sec = ts->tv_sec; |
John Stultz | b44d50d | 2012-07-23 16:22:37 -0400 | [diff] [blame] | 57 | tk->xtime_nsec = (u64)ts->tv_nsec << tk->shift; |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 58 | } |
| 59 | |
| 60 | static void tk_xtime_add(struct timekeeper *tk, const struct timespec *ts) |
| 61 | { |
| 62 | tk->xtime_sec += ts->tv_sec; |
John Stultz | b44d50d | 2012-07-23 16:22:37 -0400 | [diff] [blame] | 63 | tk->xtime_nsec += (u64)ts->tv_nsec << tk->shift; |
John Stultz | 784ffcb | 2012-08-21 20:30:46 -0400 | [diff] [blame] | 64 | tk_normalize_xtime(tk); |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 65 | } |
John Stultz | 8fcce54 | 2011-11-14 11:46:39 -0800 | [diff] [blame] | 66 | |
John Stultz | 6d0ef90 | 2012-07-27 14:48:12 -0400 | [diff] [blame] | 67 | static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec wtm) |
| 68 | { |
| 69 | struct timespec tmp; |
| 70 | |
| 71 | /* |
| 72 | * Verify consistency of: offset_real = -wall_to_monotonic |
| 73 | * before modifying anything |
| 74 | */ |
| 75 | set_normalized_timespec(&tmp, -tk->wall_to_monotonic.tv_sec, |
| 76 | -tk->wall_to_monotonic.tv_nsec); |
| 77 | WARN_ON_ONCE(tk->offs_real.tv64 != timespec_to_ktime(tmp).tv64); |
| 78 | tk->wall_to_monotonic = wtm; |
| 79 | set_normalized_timespec(&tmp, -wtm.tv_sec, -wtm.tv_nsec); |
| 80 | tk->offs_real = timespec_to_ktime(tmp); |
| 81 | } |
| 82 | |
| 83 | static void tk_set_sleep_time(struct timekeeper *tk, struct timespec t) |
| 84 | { |
| 85 | /* Verify consistency before modifying */ |
| 86 | WARN_ON_ONCE(tk->offs_boot.tv64 != timespec_to_ktime(tk->total_sleep_time).tv64); |
| 87 | |
| 88 | tk->total_sleep_time = t; |
| 89 | tk->offs_boot = timespec_to_ktime(t); |
| 90 | } |
| 91 | |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 92 | /** |
| 93 | * timekeeper_setup_internals - Set up internals to use clocksource clock. |
| 94 | * |
| 95 | * @clock: Pointer to clocksource. |
| 96 | * |
| 97 | * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment |
| 98 | * pair and interval request. |
| 99 | * |
| 100 | * Unless you're the timekeeping code, you should not be using this! |
| 101 | */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 102 | static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock) |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 103 | { |
| 104 | cycle_t interval; |
Kasper Pedersen | a386b5a | 2010-10-20 15:55:15 -0700 | [diff] [blame] | 105 | u64 tmp, ntpinterval; |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 106 | struct clocksource *old_clock; |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 107 | |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 108 | old_clock = tk->clock; |
| 109 | tk->clock = clock; |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 110 | clock->cycle_last = clock->read(clock); |
| 111 | |
| 112 | /* Do the ns -> cycle conversion first, using original mult */ |
| 113 | tmp = NTP_INTERVAL_LENGTH; |
| 114 | tmp <<= clock->shift; |
Kasper Pedersen | a386b5a | 2010-10-20 15:55:15 -0700 | [diff] [blame] | 115 | ntpinterval = tmp; |
Martin Schwidefsky | 0a54419 | 2009-08-14 15:47:28 +0200 | [diff] [blame] | 116 | tmp += clock->mult/2; |
| 117 | do_div(tmp, clock->mult); |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 118 | if (tmp == 0) |
| 119 | tmp = 1; |
| 120 | |
| 121 | interval = (cycle_t) tmp; |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 122 | tk->cycle_interval = interval; |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 123 | |
| 124 | /* Go back from cycles -> shifted ns */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 125 | tk->xtime_interval = (u64) interval * clock->mult; |
| 126 | tk->xtime_remainder = ntpinterval - tk->xtime_interval; |
| 127 | tk->raw_interval = |
Martin Schwidefsky | 0a54419 | 2009-08-14 15:47:28 +0200 | [diff] [blame] | 128 | ((u64) interval * clock->mult) >> clock->shift; |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 129 | |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 130 | /* if changing clocks, convert xtime_nsec shift units */ |
| 131 | if (old_clock) { |
| 132 | int shift_change = clock->shift - old_clock->shift; |
| 133 | if (shift_change < 0) |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 134 | tk->xtime_nsec >>= -shift_change; |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 135 | else |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 136 | tk->xtime_nsec <<= shift_change; |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 137 | } |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 138 | tk->shift = clock->shift; |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 139 | |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 140 | tk->ntp_error = 0; |
| 141 | tk->ntp_error_shift = NTP_SCALE_SHIFT - clock->shift; |
Martin Schwidefsky | 0a54419 | 2009-08-14 15:47:28 +0200 | [diff] [blame] | 142 | |
| 143 | /* |
| 144 | * The timekeeper keeps its own mult values for the currently |
| 145 | * active clocksource. These value will be adjusted via NTP |
| 146 | * to counteract clock drifting. |
| 147 | */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 148 | tk->mult = clock->mult; |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 149 | } |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 150 | |
Martin Schwidefsky | 2ba2a30 | 2009-08-14 15:47:29 +0200 | [diff] [blame] | 151 | /* Timekeeper helper functions. */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 152 | static inline s64 timekeeping_get_ns(struct timekeeper *tk) |
Martin Schwidefsky | 2ba2a30 | 2009-08-14 15:47:29 +0200 | [diff] [blame] | 153 | { |
| 154 | cycle_t cycle_now, cycle_delta; |
| 155 | struct clocksource *clock; |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 156 | s64 nsec; |
Martin Schwidefsky | 2ba2a30 | 2009-08-14 15:47:29 +0200 | [diff] [blame] | 157 | |
| 158 | /* read clocksource: */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 159 | clock = tk->clock; |
Martin Schwidefsky | 2ba2a30 | 2009-08-14 15:47:29 +0200 | [diff] [blame] | 160 | cycle_now = clock->read(clock); |
| 161 | |
| 162 | /* calculate the delta since the last update_wall_time: */ |
| 163 | cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; |
| 164 | |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 165 | nsec = cycle_delta * tk->mult + tk->xtime_nsec; |
| 166 | nsec >>= tk->shift; |
John Stultz | f2a5a08 | 2012-07-13 01:21:55 -0400 | [diff] [blame] | 167 | |
| 168 | /* If arch requires, add in gettimeoffset() */ |
| 169 | return nsec + arch_gettimeoffset(); |
Martin Schwidefsky | 2ba2a30 | 2009-08-14 15:47:29 +0200 | [diff] [blame] | 170 | } |
| 171 | |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 172 | static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk) |
Martin Schwidefsky | 2ba2a30 | 2009-08-14 15:47:29 +0200 | [diff] [blame] | 173 | { |
| 174 | cycle_t cycle_now, cycle_delta; |
| 175 | struct clocksource *clock; |
John Stultz | f2a5a08 | 2012-07-13 01:21:55 -0400 | [diff] [blame] | 176 | s64 nsec; |
Martin Schwidefsky | 2ba2a30 | 2009-08-14 15:47:29 +0200 | [diff] [blame] | 177 | |
| 178 | /* read clocksource: */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 179 | clock = tk->clock; |
Martin Schwidefsky | 2ba2a30 | 2009-08-14 15:47:29 +0200 | [diff] [blame] | 180 | cycle_now = clock->read(clock); |
| 181 | |
| 182 | /* calculate the delta since the last update_wall_time: */ |
| 183 | cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; |
| 184 | |
John Stultz | f2a5a08 | 2012-07-13 01:21:55 -0400 | [diff] [blame] | 185 | /* convert delta to nanoseconds. */ |
| 186 | nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); |
| 187 | |
| 188 | /* If arch requires, add in gettimeoffset() */ |
| 189 | return nsec + arch_gettimeoffset(); |
Martin Schwidefsky | 2ba2a30 | 2009-08-14 15:47:29 +0200 | [diff] [blame] | 190 | } |
| 191 | |
Thomas Gleixner | cc06268 | 2011-11-13 23:19:49 +0000 | [diff] [blame] | 192 | /* must hold write on timekeeper.lock */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 193 | static void timekeeping_update(struct timekeeper *tk, bool clearntp) |
Thomas Gleixner | cc06268 | 2011-11-13 23:19:49 +0000 | [diff] [blame] | 194 | { |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 195 | struct timespec xt; |
| 196 | |
Thomas Gleixner | cc06268 | 2011-11-13 23:19:49 +0000 | [diff] [blame] | 197 | if (clearntp) { |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 198 | tk->ntp_error = 0; |
Thomas Gleixner | cc06268 | 2011-11-13 23:19:49 +0000 | [diff] [blame] | 199 | ntp_clear(); |
| 200 | } |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 201 | xt = tk_xtime(tk); |
| 202 | update_vsyscall(&xt, &tk->wall_to_monotonic, tk->clock, tk->mult); |
Thomas Gleixner | cc06268 | 2011-11-13 23:19:49 +0000 | [diff] [blame] | 203 | } |
| 204 | |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 205 | /** |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 206 | * timekeeping_forward_now - update clock to the current time |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 207 | * |
Roman Zippel | 9a05511 | 2008-08-20 16:37:28 -0700 | [diff] [blame] | 208 | * Forward the current clock to update its state since the last call to |
| 209 | * update_wall_time(). This is useful before significant clock changes, |
| 210 | * as it avoids having to deal with this time offset explicitly. |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 211 | */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 212 | static void timekeeping_forward_now(struct timekeeper *tk) |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 213 | { |
| 214 | cycle_t cycle_now, cycle_delta; |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 215 | struct clocksource *clock; |
Roman Zippel | 9a05511 | 2008-08-20 16:37:28 -0700 | [diff] [blame] | 216 | s64 nsec; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 217 | |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 218 | clock = tk->clock; |
Martin Schwidefsky | a0f7d48 | 2009-08-14 15:47:19 +0200 | [diff] [blame] | 219 | cycle_now = clock->read(clock); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 220 | cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; |
Roman Zippel | 9a05511 | 2008-08-20 16:37:28 -0700 | [diff] [blame] | 221 | clock->cycle_last = cycle_now; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 222 | |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 223 | tk->xtime_nsec += cycle_delta * tk->mult; |
john stultz | 7d27558 | 2009-05-01 13:10:26 -0700 | [diff] [blame] | 224 | |
| 225 | /* If arch requires, add in gettimeoffset() */ |
Andreas Schwab | 85dc8f0 | 2012-08-21 20:30:47 -0400 | [diff] [blame] | 226 | tk->xtime_nsec += (u64)arch_gettimeoffset() << tk->shift; |
john stultz | 7d27558 | 2009-05-01 13:10:26 -0700 | [diff] [blame] | 227 | |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 228 | tk_normalize_xtime(tk); |
John Stultz | 2d42244 | 2008-08-20 16:37:30 -0700 | [diff] [blame] | 229 | |
Martin Schwidefsky | 0a54419 | 2009-08-14 15:47:28 +0200 | [diff] [blame] | 230 | nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 231 | timespec_add_ns(&tk->raw_time, nsec); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 232 | } |
| 233 | |
| 234 | /** |
Geert Uytterhoeven | efd9ac8 | 2008-01-30 13:30:01 +0100 | [diff] [blame] | 235 | * getnstimeofday - Returns the time of day in a timespec |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 236 | * @ts: pointer to the timespec to be set |
| 237 | * |
Geert Uytterhoeven | efd9ac8 | 2008-01-30 13:30:01 +0100 | [diff] [blame] | 238 | * Returns the time of day in a timespec. |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 239 | */ |
Geert Uytterhoeven | efd9ac8 | 2008-01-30 13:30:01 +0100 | [diff] [blame] | 240 | void getnstimeofday(struct timespec *ts) |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 241 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 242 | struct timekeeper *tk = &timekeeper; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 243 | unsigned long seq; |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 244 | s64 nsecs = 0; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 245 | |
Thomas Gleixner | 1c5745a | 2008-12-22 23:05:28 +0100 | [diff] [blame] | 246 | WARN_ON(timekeeping_suspended); |
| 247 | |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 248 | do { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 249 | seq = read_seqbegin(&tk->lock); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 250 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 251 | ts->tv_sec = tk->xtime_sec; |
John Stultz | ec145ba | 2012-09-11 19:26:03 -0400 | [diff] [blame] | 252 | nsecs = timekeeping_get_ns(tk); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 253 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 254 | } while (read_seqretry(&tk->lock, seq)); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 255 | |
John Stultz | ec145ba | 2012-09-11 19:26:03 -0400 | [diff] [blame] | 256 | ts->tv_nsec = 0; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 257 | timespec_add_ns(ts, nsecs); |
| 258 | } |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 259 | EXPORT_SYMBOL(getnstimeofday); |
| 260 | |
Martin Schwidefsky | 951ed4d | 2009-07-07 11:27:28 +0200 | [diff] [blame] | 261 | ktime_t ktime_get(void) |
| 262 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 263 | struct timekeeper *tk = &timekeeper; |
Martin Schwidefsky | 951ed4d | 2009-07-07 11:27:28 +0200 | [diff] [blame] | 264 | unsigned int seq; |
| 265 | s64 secs, nsecs; |
| 266 | |
| 267 | WARN_ON(timekeeping_suspended); |
| 268 | |
| 269 | do { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 270 | seq = read_seqbegin(&tk->lock); |
| 271 | secs = tk->xtime_sec + tk->wall_to_monotonic.tv_sec; |
| 272 | nsecs = timekeeping_get_ns(tk) + tk->wall_to_monotonic.tv_nsec; |
Martin Schwidefsky | 951ed4d | 2009-07-07 11:27:28 +0200 | [diff] [blame] | 273 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 274 | } while (read_seqretry(&tk->lock, seq)); |
Martin Schwidefsky | 951ed4d | 2009-07-07 11:27:28 +0200 | [diff] [blame] | 275 | /* |
| 276 | * Use ktime_set/ktime_add_ns to create a proper ktime on |
| 277 | * 32-bit architectures without CONFIG_KTIME_SCALAR. |
| 278 | */ |
| 279 | return ktime_add_ns(ktime_set(secs, 0), nsecs); |
| 280 | } |
| 281 | EXPORT_SYMBOL_GPL(ktime_get); |
| 282 | |
| 283 | /** |
| 284 | * ktime_get_ts - get the monotonic clock in timespec format |
| 285 | * @ts: pointer to timespec variable |
| 286 | * |
| 287 | * The function calculates the monotonic clock from the realtime |
| 288 | * clock and the wall_to_monotonic offset and stores the result |
| 289 | * in normalized timespec format in the variable pointed to by @ts. |
| 290 | */ |
| 291 | void ktime_get_ts(struct timespec *ts) |
| 292 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 293 | struct timekeeper *tk = &timekeeper; |
Martin Schwidefsky | 951ed4d | 2009-07-07 11:27:28 +0200 | [diff] [blame] | 294 | struct timespec tomono; |
John Stultz | ec145ba | 2012-09-11 19:26:03 -0400 | [diff] [blame] | 295 | s64 nsec; |
Martin Schwidefsky | 951ed4d | 2009-07-07 11:27:28 +0200 | [diff] [blame] | 296 | unsigned int seq; |
Martin Schwidefsky | 951ed4d | 2009-07-07 11:27:28 +0200 | [diff] [blame] | 297 | |
| 298 | WARN_ON(timekeeping_suspended); |
| 299 | |
| 300 | do { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 301 | seq = read_seqbegin(&tk->lock); |
| 302 | ts->tv_sec = tk->xtime_sec; |
John Stultz | ec145ba | 2012-09-11 19:26:03 -0400 | [diff] [blame] | 303 | nsec = timekeeping_get_ns(tk); |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 304 | tomono = tk->wall_to_monotonic; |
Martin Schwidefsky | 951ed4d | 2009-07-07 11:27:28 +0200 | [diff] [blame] | 305 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 306 | } while (read_seqretry(&tk->lock, seq)); |
Martin Schwidefsky | 951ed4d | 2009-07-07 11:27:28 +0200 | [diff] [blame] | 307 | |
John Stultz | ec145ba | 2012-09-11 19:26:03 -0400 | [diff] [blame] | 308 | ts->tv_sec += tomono.tv_sec; |
| 309 | ts->tv_nsec = 0; |
| 310 | timespec_add_ns(ts, nsec + tomono.tv_nsec); |
Martin Schwidefsky | 951ed4d | 2009-07-07 11:27:28 +0200 | [diff] [blame] | 311 | } |
| 312 | EXPORT_SYMBOL_GPL(ktime_get_ts); |
| 313 | |
Alexander Gordeev | e2c18e4 | 2011-01-12 17:00:57 -0800 | [diff] [blame] | 314 | #ifdef CONFIG_NTP_PPS |
| 315 | |
| 316 | /** |
| 317 | * getnstime_raw_and_real - get day and raw monotonic time in timespec format |
| 318 | * @ts_raw: pointer to the timespec to be set to raw monotonic time |
| 319 | * @ts_real: pointer to the timespec to be set to the time of day |
| 320 | * |
| 321 | * This function reads both the time of day and raw monotonic time at the |
| 322 | * same time atomically and stores the resulting timestamps in timespec |
| 323 | * format. |
| 324 | */ |
| 325 | void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real) |
| 326 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 327 | struct timekeeper *tk = &timekeeper; |
Alexander Gordeev | e2c18e4 | 2011-01-12 17:00:57 -0800 | [diff] [blame] | 328 | unsigned long seq; |
| 329 | s64 nsecs_raw, nsecs_real; |
| 330 | |
| 331 | WARN_ON_ONCE(timekeeping_suspended); |
| 332 | |
| 333 | do { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 334 | seq = read_seqbegin(&tk->lock); |
Alexander Gordeev | e2c18e4 | 2011-01-12 17:00:57 -0800 | [diff] [blame] | 335 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 336 | *ts_raw = tk->raw_time; |
| 337 | ts_real->tv_sec = tk->xtime_sec; |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 338 | ts_real->tv_nsec = 0; |
Alexander Gordeev | e2c18e4 | 2011-01-12 17:00:57 -0800 | [diff] [blame] | 339 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 340 | nsecs_raw = timekeeping_get_ns_raw(tk); |
| 341 | nsecs_real = timekeeping_get_ns(tk); |
Alexander Gordeev | e2c18e4 | 2011-01-12 17:00:57 -0800 | [diff] [blame] | 342 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 343 | } while (read_seqretry(&tk->lock, seq)); |
Alexander Gordeev | e2c18e4 | 2011-01-12 17:00:57 -0800 | [diff] [blame] | 344 | |
| 345 | timespec_add_ns(ts_raw, nsecs_raw); |
| 346 | timespec_add_ns(ts_real, nsecs_real); |
| 347 | } |
| 348 | EXPORT_SYMBOL(getnstime_raw_and_real); |
| 349 | |
| 350 | #endif /* CONFIG_NTP_PPS */ |
| 351 | |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 352 | /** |
| 353 | * do_gettimeofday - Returns the time of day in a timeval |
| 354 | * @tv: pointer to the timeval to be set |
| 355 | * |
Geert Uytterhoeven | efd9ac8 | 2008-01-30 13:30:01 +0100 | [diff] [blame] | 356 | * NOTE: Users should be converted to using getnstimeofday() |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 357 | */ |
| 358 | void do_gettimeofday(struct timeval *tv) |
| 359 | { |
| 360 | struct timespec now; |
| 361 | |
Geert Uytterhoeven | efd9ac8 | 2008-01-30 13:30:01 +0100 | [diff] [blame] | 362 | getnstimeofday(&now); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 363 | tv->tv_sec = now.tv_sec; |
| 364 | tv->tv_usec = now.tv_nsec/1000; |
| 365 | } |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 366 | EXPORT_SYMBOL(do_gettimeofday); |
Richard Cochran | d239f49 | 2012-04-27 10:12:42 +0200 | [diff] [blame] | 367 | |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 368 | /** |
| 369 | * do_settimeofday - Sets the time of day |
| 370 | * @tv: pointer to the timespec variable containing the new time |
| 371 | * |
| 372 | * Sets the time of day to the new time and update NTP and notify hrtimers |
| 373 | */ |
Richard Cochran | 1e6d767 | 2011-02-01 13:50:58 +0000 | [diff] [blame] | 374 | int do_settimeofday(const struct timespec *tv) |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 375 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 376 | struct timekeeper *tk = &timekeeper; |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 377 | struct timespec ts_delta, xt; |
John Stultz | 92c1d3e | 2011-11-14 14:05:44 -0800 | [diff] [blame] | 378 | unsigned long flags; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 379 | |
John Stultz | cee5848 | 2012-08-31 13:30:06 -0400 | [diff] [blame] | 380 | if (!timespec_valid_strict(tv)) |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 381 | return -EINVAL; |
| 382 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 383 | write_seqlock_irqsave(&tk->lock, flags); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 384 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 385 | timekeeping_forward_now(tk); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 386 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 387 | xt = tk_xtime(tk); |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 388 | ts_delta.tv_sec = tv->tv_sec - xt.tv_sec; |
| 389 | ts_delta.tv_nsec = tv->tv_nsec - xt.tv_nsec; |
| 390 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 391 | 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] | 392 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 393 | tk_set_xtime(tk, tv); |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 394 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 395 | timekeeping_update(tk, true); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 396 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 397 | write_sequnlock_irqrestore(&tk->lock, flags); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 398 | |
| 399 | /* signal hrtimers about time change */ |
| 400 | clock_was_set(); |
| 401 | |
| 402 | return 0; |
| 403 | } |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 404 | EXPORT_SYMBOL(do_settimeofday); |
| 405 | |
John Stultz | c528f7c | 2011-02-01 13:52:17 +0000 | [diff] [blame] | 406 | /** |
| 407 | * timekeeping_inject_offset - Adds or subtracts from the current time. |
| 408 | * @tv: pointer to the timespec variable containing the offset |
| 409 | * |
| 410 | * Adds or subtracts an offset value from the current time. |
| 411 | */ |
| 412 | int timekeeping_inject_offset(struct timespec *ts) |
| 413 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 414 | struct timekeeper *tk = &timekeeper; |
John Stultz | 92c1d3e | 2011-11-14 14:05:44 -0800 | [diff] [blame] | 415 | unsigned long flags; |
John Stultz | 4e8b145 | 2012-08-08 15:36:20 -0400 | [diff] [blame] | 416 | struct timespec tmp; |
| 417 | int ret = 0; |
John Stultz | c528f7c | 2011-02-01 13:52:17 +0000 | [diff] [blame] | 418 | |
| 419 | if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC) |
| 420 | return -EINVAL; |
| 421 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 422 | write_seqlock_irqsave(&tk->lock, flags); |
John Stultz | c528f7c | 2011-02-01 13:52:17 +0000 | [diff] [blame] | 423 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 424 | timekeeping_forward_now(tk); |
John Stultz | c528f7c | 2011-02-01 13:52:17 +0000 | [diff] [blame] | 425 | |
John Stultz | 4e8b145 | 2012-08-08 15:36:20 -0400 | [diff] [blame] | 426 | /* Make sure the proposed value is valid */ |
| 427 | tmp = timespec_add(tk_xtime(tk), *ts); |
John Stultz | cee5848 | 2012-08-31 13:30:06 -0400 | [diff] [blame] | 428 | if (!timespec_valid_strict(&tmp)) { |
John Stultz | 4e8b145 | 2012-08-08 15:36:20 -0400 | [diff] [blame] | 429 | ret = -EINVAL; |
| 430 | goto error; |
| 431 | } |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 432 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 433 | tk_xtime_add(tk, ts); |
| 434 | 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] | 435 | |
John Stultz | 4e8b145 | 2012-08-08 15:36:20 -0400 | [diff] [blame] | 436 | 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] | 437 | timekeeping_update(tk, true); |
John Stultz | c528f7c | 2011-02-01 13:52:17 +0000 | [diff] [blame] | 438 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 439 | write_sequnlock_irqrestore(&tk->lock, flags); |
John Stultz | c528f7c | 2011-02-01 13:52:17 +0000 | [diff] [blame] | 440 | |
| 441 | /* signal hrtimers about time change */ |
| 442 | clock_was_set(); |
| 443 | |
John Stultz | 4e8b145 | 2012-08-08 15:36:20 -0400 | [diff] [blame] | 444 | return ret; |
John Stultz | c528f7c | 2011-02-01 13:52:17 +0000 | [diff] [blame] | 445 | } |
| 446 | EXPORT_SYMBOL(timekeeping_inject_offset); |
| 447 | |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 448 | /** |
| 449 | * change_clocksource - Swaps clocksources if a new one is available |
| 450 | * |
| 451 | * Accumulates current time interval and initializes new clocksource |
| 452 | */ |
Martin Schwidefsky | 75c5158 | 2009-08-14 15:47:30 +0200 | [diff] [blame] | 453 | static int change_clocksource(void *data) |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 454 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 455 | struct timekeeper *tk = &timekeeper; |
Magnus Damm | 4614e6a | 2009-04-21 12:24:02 -0700 | [diff] [blame] | 456 | struct clocksource *new, *old; |
John Stultz | f695cf9 | 2012-03-14 16:38:15 -0700 | [diff] [blame] | 457 | unsigned long flags; |
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 | new = (struct clocksource *) data; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 460 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 461 | write_seqlock_irqsave(&tk->lock, flags); |
John Stultz | f695cf9 | 2012-03-14 16:38:15 -0700 | [diff] [blame] | 462 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 463 | timekeeping_forward_now(tk); |
Martin Schwidefsky | 75c5158 | 2009-08-14 15:47:30 +0200 | [diff] [blame] | 464 | if (!new->enable || new->enable(new) == 0) { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 465 | old = tk->clock; |
| 466 | tk_setup_internals(tk, new); |
Martin Schwidefsky | 75c5158 | 2009-08-14 15:47:30 +0200 | [diff] [blame] | 467 | if (old->disable) |
| 468 | old->disable(old); |
| 469 | } |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 470 | timekeeping_update(tk, true); |
John Stultz | f695cf9 | 2012-03-14 16:38:15 -0700 | [diff] [blame] | 471 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 472 | write_sequnlock_irqrestore(&tk->lock, flags); |
John Stultz | f695cf9 | 2012-03-14 16:38:15 -0700 | [diff] [blame] | 473 | |
Martin Schwidefsky | 75c5158 | 2009-08-14 15:47:30 +0200 | [diff] [blame] | 474 | return 0; |
| 475 | } |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 476 | |
Martin Schwidefsky | 75c5158 | 2009-08-14 15:47:30 +0200 | [diff] [blame] | 477 | /** |
| 478 | * timekeeping_notify - Install a new clock source |
| 479 | * @clock: pointer to the clock source |
| 480 | * |
| 481 | * This function is called from clocksource.c after a new, better clock |
| 482 | * source has been registered. The caller holds the clocksource_mutex. |
| 483 | */ |
| 484 | void timekeeping_notify(struct clocksource *clock) |
| 485 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 486 | struct timekeeper *tk = &timekeeper; |
| 487 | |
| 488 | if (tk->clock == clock) |
Magnus Damm | 4614e6a | 2009-04-21 12:24:02 -0700 | [diff] [blame] | 489 | return; |
Martin Schwidefsky | 75c5158 | 2009-08-14 15:47:30 +0200 | [diff] [blame] | 490 | stop_machine(change_clocksource, clock, NULL); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 491 | tick_clock_notify(); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 492 | } |
Martin Schwidefsky | 75c5158 | 2009-08-14 15:47:30 +0200 | [diff] [blame] | 493 | |
Thomas Gleixner | a40f262 | 2009-07-07 13:00:31 +0200 | [diff] [blame] | 494 | /** |
| 495 | * ktime_get_real - get the real (wall-) time in ktime_t format |
| 496 | * |
| 497 | * returns the time in ktime_t format |
| 498 | */ |
| 499 | ktime_t ktime_get_real(void) |
| 500 | { |
| 501 | struct timespec now; |
| 502 | |
| 503 | getnstimeofday(&now); |
| 504 | |
| 505 | return timespec_to_ktime(now); |
| 506 | } |
| 507 | EXPORT_SYMBOL_GPL(ktime_get_real); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 508 | |
| 509 | /** |
John Stultz | 2d42244 | 2008-08-20 16:37:30 -0700 | [diff] [blame] | 510 | * getrawmonotonic - Returns the raw monotonic time in a timespec |
| 511 | * @ts: pointer to the timespec to be set |
| 512 | * |
| 513 | * Returns the raw monotonic time (completely un-modified by ntp) |
| 514 | */ |
| 515 | void getrawmonotonic(struct timespec *ts) |
| 516 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 517 | struct timekeeper *tk = &timekeeper; |
John Stultz | 2d42244 | 2008-08-20 16:37:30 -0700 | [diff] [blame] | 518 | unsigned long seq; |
| 519 | s64 nsecs; |
John Stultz | 2d42244 | 2008-08-20 16:37:30 -0700 | [diff] [blame] | 520 | |
| 521 | do { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 522 | seq = read_seqbegin(&tk->lock); |
| 523 | nsecs = timekeeping_get_ns_raw(tk); |
| 524 | *ts = tk->raw_time; |
John Stultz | 2d42244 | 2008-08-20 16:37:30 -0700 | [diff] [blame] | 525 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 526 | } while (read_seqretry(&tk->lock, seq)); |
John Stultz | 2d42244 | 2008-08-20 16:37:30 -0700 | [diff] [blame] | 527 | |
| 528 | timespec_add_ns(ts, nsecs); |
| 529 | } |
| 530 | EXPORT_SYMBOL(getrawmonotonic); |
| 531 | |
John Stultz | 2d42244 | 2008-08-20 16:37:30 -0700 | [diff] [blame] | 532 | /** |
Li Zefan | cf4fc6c | 2008-02-08 04:19:24 -0800 | [diff] [blame] | 533 | * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 534 | */ |
Li Zefan | cf4fc6c | 2008-02-08 04:19:24 -0800 | [diff] [blame] | 535 | int timekeeping_valid_for_hres(void) |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 536 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 537 | struct timekeeper *tk = &timekeeper; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 538 | unsigned long seq; |
| 539 | int ret; |
| 540 | |
| 541 | do { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 542 | seq = read_seqbegin(&tk->lock); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 543 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 544 | ret = tk->clock->flags & CLOCK_SOURCE_VALID_FOR_HRES; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 545 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 546 | } while (read_seqretry(&tk->lock, seq)); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 547 | |
| 548 | return ret; |
| 549 | } |
| 550 | |
| 551 | /** |
Jon Hunter | 9896246 | 2009-08-18 12:45:10 -0500 | [diff] [blame] | 552 | * timekeeping_max_deferment - Returns max time the clocksource can be deferred |
Jon Hunter | 9896246 | 2009-08-18 12:45:10 -0500 | [diff] [blame] | 553 | */ |
| 554 | u64 timekeeping_max_deferment(void) |
| 555 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 556 | struct timekeeper *tk = &timekeeper; |
John Stultz | 70471f2 | 2011-11-14 12:48:10 -0800 | [diff] [blame] | 557 | unsigned long seq; |
| 558 | u64 ret; |
John Stultz | 42e71e8 | 2012-07-13 01:21:51 -0400 | [diff] [blame] | 559 | |
John Stultz | 70471f2 | 2011-11-14 12:48:10 -0800 | [diff] [blame] | 560 | do { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 561 | seq = read_seqbegin(&tk->lock); |
John Stultz | 70471f2 | 2011-11-14 12:48:10 -0800 | [diff] [blame] | 562 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 563 | ret = tk->clock->max_idle_ns; |
John Stultz | 70471f2 | 2011-11-14 12:48:10 -0800 | [diff] [blame] | 564 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 565 | } while (read_seqretry(&tk->lock, seq)); |
John Stultz | 70471f2 | 2011-11-14 12:48:10 -0800 | [diff] [blame] | 566 | |
| 567 | return ret; |
Jon Hunter | 9896246 | 2009-08-18 12:45:10 -0500 | [diff] [blame] | 568 | } |
| 569 | |
| 570 | /** |
Martin Schwidefsky | d4f587c | 2009-08-14 15:47:31 +0200 | [diff] [blame] | 571 | * read_persistent_clock - Return time from the persistent clock. |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 572 | * |
| 573 | * Weak dummy function for arches that do not yet support it. |
Martin Schwidefsky | d4f587c | 2009-08-14 15:47:31 +0200 | [diff] [blame] | 574 | * Reads the time from the battery backed persistent clock. |
| 575 | * 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] | 576 | * |
| 577 | * XXX - Do be sure to remove it once all arches implement it. |
| 578 | */ |
Martin Schwidefsky | d4f587c | 2009-08-14 15:47:31 +0200 | [diff] [blame] | 579 | void __attribute__((weak)) read_persistent_clock(struct timespec *ts) |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 580 | { |
Martin Schwidefsky | d4f587c | 2009-08-14 15:47:31 +0200 | [diff] [blame] | 581 | ts->tv_sec = 0; |
| 582 | ts->tv_nsec = 0; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 583 | } |
| 584 | |
Martin Schwidefsky | 23970e3 | 2009-08-14 15:47:32 +0200 | [diff] [blame] | 585 | /** |
| 586 | * read_boot_clock - Return time of the system start. |
| 587 | * |
| 588 | * Weak dummy function for arches that do not yet support it. |
| 589 | * Function to read the exact time the system has been started. |
| 590 | * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported. |
| 591 | * |
| 592 | * XXX - Do be sure to remove it once all arches implement it. |
| 593 | */ |
| 594 | void __attribute__((weak)) read_boot_clock(struct timespec *ts) |
| 595 | { |
| 596 | ts->tv_sec = 0; |
| 597 | ts->tv_nsec = 0; |
| 598 | } |
| 599 | |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 600 | /* |
| 601 | * timekeeping_init - Initializes the clocksource and common timekeeping values |
| 602 | */ |
| 603 | void __init timekeeping_init(void) |
| 604 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 605 | struct timekeeper *tk = &timekeeper; |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 606 | struct clocksource *clock; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 607 | unsigned long flags; |
John Stultz | 6d0ef90 | 2012-07-27 14:48:12 -0400 | [diff] [blame] | 608 | struct timespec now, boot, tmp; |
Martin Schwidefsky | d4f587c | 2009-08-14 15:47:31 +0200 | [diff] [blame] | 609 | |
| 610 | read_persistent_clock(&now); |
John Stultz | cee5848 | 2012-08-31 13:30:06 -0400 | [diff] [blame] | 611 | if (!timespec_valid_strict(&now)) { |
John Stultz | 4e8b145 | 2012-08-08 15:36:20 -0400 | [diff] [blame] | 612 | pr_warn("WARNING: Persistent clock returned invalid value!\n" |
| 613 | " Check your CMOS/BIOS settings.\n"); |
| 614 | now.tv_sec = 0; |
| 615 | now.tv_nsec = 0; |
| 616 | } |
| 617 | |
Martin Schwidefsky | 23970e3 | 2009-08-14 15:47:32 +0200 | [diff] [blame] | 618 | read_boot_clock(&boot); |
John Stultz | cee5848 | 2012-08-31 13:30:06 -0400 | [diff] [blame] | 619 | if (!timespec_valid_strict(&boot)) { |
John Stultz | 4e8b145 | 2012-08-08 15:36:20 -0400 | [diff] [blame] | 620 | pr_warn("WARNING: Boot clock returned invalid value!\n" |
| 621 | " Check your CMOS/BIOS settings.\n"); |
| 622 | boot.tv_sec = 0; |
| 623 | boot.tv_nsec = 0; |
| 624 | } |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 625 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 626 | seqlock_init(&tk->lock); |
John Stultz | 70471f2 | 2011-11-14 12:48:10 -0800 | [diff] [blame] | 627 | |
Roman Zippel | 7dffa3c | 2008-05-01 04:34:41 -0700 | [diff] [blame] | 628 | ntp_init(); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 629 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 630 | write_seqlock_irqsave(&tk->lock, flags); |
Martin Schwidefsky | f1b8274 | 2009-08-14 15:47:21 +0200 | [diff] [blame] | 631 | clock = clocksource_default_clock(); |
Martin Schwidefsky | a0f7d48 | 2009-08-14 15:47:19 +0200 | [diff] [blame] | 632 | if (clock->enable) |
| 633 | clock->enable(clock); |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 634 | tk_setup_internals(tk, clock); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 635 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 636 | tk_set_xtime(tk, &now); |
| 637 | tk->raw_time.tv_sec = 0; |
| 638 | tk->raw_time.tv_nsec = 0; |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 639 | if (boot.tv_sec == 0 && boot.tv_nsec == 0) |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 640 | boot = tk_xtime(tk); |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 641 | |
John Stultz | 6d0ef90 | 2012-07-27 14:48:12 -0400 | [diff] [blame] | 642 | set_normalized_timespec(&tmp, -boot.tv_sec, -boot.tv_nsec); |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 643 | tk_set_wall_to_mono(tk, tmp); |
John Stultz | 6d0ef90 | 2012-07-27 14:48:12 -0400 | [diff] [blame] | 644 | |
| 645 | tmp.tv_sec = 0; |
| 646 | tmp.tv_nsec = 0; |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 647 | tk_set_sleep_time(tk, tmp); |
John Stultz | 6d0ef90 | 2012-07-27 14:48:12 -0400 | [diff] [blame] | 648 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 649 | write_sequnlock_irqrestore(&tk->lock, flags); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 650 | } |
| 651 | |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 652 | /* time in seconds when suspend began */ |
Martin Schwidefsky | d4f587c | 2009-08-14 15:47:31 +0200 | [diff] [blame] | 653 | static struct timespec timekeeping_suspend_time; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 654 | |
| 655 | /** |
John Stultz | 304529b | 2011-04-01 14:32:09 -0700 | [diff] [blame] | 656 | * __timekeeping_inject_sleeptime - Internal function to add sleep interval |
| 657 | * @delta: pointer to a timespec delta value |
| 658 | * |
| 659 | * Takes a timespec offset measuring a suspend interval and properly |
| 660 | * adds the sleep offset to the timekeeping variables. |
| 661 | */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 662 | static void __timekeeping_inject_sleeptime(struct timekeeper *tk, |
| 663 | struct timespec *delta) |
John Stultz | 304529b | 2011-04-01 14:32:09 -0700 | [diff] [blame] | 664 | { |
John Stultz | cee5848 | 2012-08-31 13:30:06 -0400 | [diff] [blame] | 665 | if (!timespec_valid_strict(delta)) { |
John Stultz | cbaa515 | 2011-07-20 15:42:55 -0700 | [diff] [blame] | 666 | printk(KERN_WARNING "__timekeeping_inject_sleeptime: Invalid " |
John Stultz | cb5de2f8d | 2011-06-01 18:18:09 -0700 | [diff] [blame] | 667 | "sleep delta value!\n"); |
| 668 | return; |
| 669 | } |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 670 | tk_xtime_add(tk, delta); |
John Stultz | 6d0ef90 | 2012-07-27 14:48:12 -0400 | [diff] [blame] | 671 | tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *delta)); |
| 672 | tk_set_sleep_time(tk, timespec_add(tk->total_sleep_time, *delta)); |
John Stultz | 304529b | 2011-04-01 14:32:09 -0700 | [diff] [blame] | 673 | } |
| 674 | |
John Stultz | 304529b | 2011-04-01 14:32:09 -0700 | [diff] [blame] | 675 | /** |
| 676 | * timekeeping_inject_sleeptime - Adds suspend interval to timeekeeping values |
| 677 | * @delta: pointer to a timespec delta value |
| 678 | * |
| 679 | * This hook is for architectures that cannot support read_persistent_clock |
| 680 | * because their RTC/persistent clock is only accessible when irqs are enabled. |
| 681 | * |
| 682 | * This function should only be called by rtc_resume(), and allows |
| 683 | * a suspend offset to be injected into the timekeeping values. |
| 684 | */ |
| 685 | void timekeeping_inject_sleeptime(struct timespec *delta) |
| 686 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 687 | struct timekeeper *tk = &timekeeper; |
John Stultz | 92c1d3e | 2011-11-14 14:05:44 -0800 | [diff] [blame] | 688 | unsigned long flags; |
John Stultz | 304529b | 2011-04-01 14:32:09 -0700 | [diff] [blame] | 689 | struct timespec ts; |
| 690 | |
| 691 | /* Make sure we don't set the clock twice */ |
| 692 | read_persistent_clock(&ts); |
| 693 | if (!(ts.tv_sec == 0 && ts.tv_nsec == 0)) |
| 694 | return; |
| 695 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 696 | write_seqlock_irqsave(&tk->lock, flags); |
John Stultz | 70471f2 | 2011-11-14 12:48:10 -0800 | [diff] [blame] | 697 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 698 | timekeeping_forward_now(tk); |
John Stultz | 304529b | 2011-04-01 14:32:09 -0700 | [diff] [blame] | 699 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 700 | __timekeeping_inject_sleeptime(tk, delta); |
John Stultz | 304529b | 2011-04-01 14:32:09 -0700 | [diff] [blame] | 701 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 702 | timekeeping_update(tk, true); |
John Stultz | 304529b | 2011-04-01 14:32:09 -0700 | [diff] [blame] | 703 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 704 | write_sequnlock_irqrestore(&tk->lock, flags); |
John Stultz | 304529b | 2011-04-01 14:32:09 -0700 | [diff] [blame] | 705 | |
| 706 | /* signal hrtimers about time change */ |
| 707 | clock_was_set(); |
| 708 | } |
| 709 | |
John Stultz | 304529b | 2011-04-01 14:32:09 -0700 | [diff] [blame] | 710 | /** |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 711 | * timekeeping_resume - Resumes the generic timekeeping subsystem. |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 712 | * |
| 713 | * This is for the generic clocksource timekeeping. |
| 714 | * xtime/wall_to_monotonic/jiffies/etc are |
| 715 | * still managed by arch specific suspend/resume code. |
| 716 | */ |
Rafael J. Wysocki | e1a85b2 | 2011-03-23 22:16:04 +0100 | [diff] [blame] | 717 | static void timekeeping_resume(void) |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 718 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 719 | struct timekeeper *tk = &timekeeper; |
John Stultz | 92c1d3e | 2011-11-14 14:05:44 -0800 | [diff] [blame] | 720 | unsigned long flags; |
Martin Schwidefsky | d4f587c | 2009-08-14 15:47:31 +0200 | [diff] [blame] | 721 | struct timespec ts; |
| 722 | |
| 723 | read_persistent_clock(&ts); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 724 | |
Thomas Gleixner | d10ff3f | 2007-05-14 11:10:02 +0200 | [diff] [blame] | 725 | clocksource_resume(); |
| 726 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 727 | write_seqlock_irqsave(&tk->lock, flags); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 728 | |
Martin Schwidefsky | d4f587c | 2009-08-14 15:47:31 +0200 | [diff] [blame] | 729 | if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) { |
| 730 | ts = timespec_sub(ts, timekeeping_suspend_time); |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 731 | __timekeeping_inject_sleeptime(tk, &ts); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 732 | } |
| 733 | /* re-base the last cycle value */ |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 734 | tk->clock->cycle_last = tk->clock->read(tk->clock); |
| 735 | tk->ntp_error = 0; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 736 | timekeeping_suspended = 0; |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 737 | timekeeping_update(tk, false); |
| 738 | write_sequnlock_irqrestore(&tk->lock, flags); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 739 | |
| 740 | touch_softlockup_watchdog(); |
| 741 | |
| 742 | clockevents_notify(CLOCK_EVT_NOTIFY_RESUME, NULL); |
| 743 | |
| 744 | /* Resume hrtimers */ |
Thomas Gleixner | b12a03c | 2011-05-02 16:48:57 +0200 | [diff] [blame] | 745 | hrtimers_resume(); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 746 | } |
| 747 | |
Rafael J. Wysocki | e1a85b2 | 2011-03-23 22:16:04 +0100 | [diff] [blame] | 748 | static int timekeeping_suspend(void) |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 749 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 750 | struct timekeeper *tk = &timekeeper; |
John Stultz | 92c1d3e | 2011-11-14 14:05:44 -0800 | [diff] [blame] | 751 | unsigned long flags; |
John Stultz | cb33217 | 2011-05-31 22:53:23 -0700 | [diff] [blame] | 752 | struct timespec delta, delta_delta; |
| 753 | static struct timespec old_delta; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 754 | |
Martin Schwidefsky | d4f587c | 2009-08-14 15:47:31 +0200 | [diff] [blame] | 755 | read_persistent_clock(&timekeeping_suspend_time); |
Thomas Gleixner | 3be9095 | 2007-09-16 15:36:43 +0200 | [diff] [blame] | 756 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 757 | write_seqlock_irqsave(&tk->lock, flags); |
| 758 | timekeeping_forward_now(tk); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 759 | timekeeping_suspended = 1; |
John Stultz | cb33217 | 2011-05-31 22:53:23 -0700 | [diff] [blame] | 760 | |
| 761 | /* |
| 762 | * To avoid drift caused by repeated suspend/resumes, |
| 763 | * which each can add ~1 second drift error, |
| 764 | * try to compensate so the difference in system time |
| 765 | * and persistent_clock time stays close to constant. |
| 766 | */ |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 767 | delta = timespec_sub(tk_xtime(tk), timekeeping_suspend_time); |
John Stultz | cb33217 | 2011-05-31 22:53:23 -0700 | [diff] [blame] | 768 | delta_delta = timespec_sub(delta, old_delta); |
| 769 | if (abs(delta_delta.tv_sec) >= 2) { |
| 770 | /* |
| 771 | * if delta_delta is too large, assume time correction |
| 772 | * has occured and set old_delta to the current delta. |
| 773 | */ |
| 774 | old_delta = delta; |
| 775 | } else { |
| 776 | /* Otherwise try to adjust old_system to compensate */ |
| 777 | timekeeping_suspend_time = |
| 778 | timespec_add(timekeeping_suspend_time, delta_delta); |
| 779 | } |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 780 | write_sequnlock_irqrestore(&tk->lock, flags); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 781 | |
| 782 | clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL); |
Magnus Damm | c54a42b | 2010-02-02 14:41:41 -0800 | [diff] [blame] | 783 | clocksource_suspend(); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 784 | |
| 785 | return 0; |
| 786 | } |
| 787 | |
| 788 | /* sysfs resume/suspend bits for timekeeping */ |
Rafael J. Wysocki | e1a85b2 | 2011-03-23 22:16:04 +0100 | [diff] [blame] | 789 | static struct syscore_ops timekeeping_syscore_ops = { |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 790 | .resume = timekeeping_resume, |
| 791 | .suspend = timekeeping_suspend, |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 792 | }; |
| 793 | |
Rafael J. Wysocki | e1a85b2 | 2011-03-23 22:16:04 +0100 | [diff] [blame] | 794 | static int __init timekeeping_init_ops(void) |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 795 | { |
Rafael J. Wysocki | e1a85b2 | 2011-03-23 22:16:04 +0100 | [diff] [blame] | 796 | register_syscore_ops(&timekeeping_syscore_ops); |
| 797 | return 0; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 798 | } |
| 799 | |
Rafael J. Wysocki | e1a85b2 | 2011-03-23 22:16:04 +0100 | [diff] [blame] | 800 | device_initcall(timekeeping_init_ops); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 801 | |
| 802 | /* |
| 803 | * If the error is already larger, we look ahead even further |
| 804 | * to compensate for late or lost adjustments. |
| 805 | */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 806 | static __always_inline int timekeeping_bigadjust(struct timekeeper *tk, |
| 807 | s64 error, s64 *interval, |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 808 | s64 *offset) |
| 809 | { |
| 810 | s64 tick_error, i; |
| 811 | u32 look_ahead, adj; |
| 812 | s32 error2, mult; |
| 813 | |
| 814 | /* |
| 815 | * Use the current error value to determine how much to look ahead. |
| 816 | * The larger the error the slower we adjust for it to avoid problems |
| 817 | * with losing too many ticks, otherwise we would overadjust and |
| 818 | * produce an even larger error. The smaller the adjustment the |
| 819 | * 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] | 820 | * 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] | 821 | * within about 1 sec (or 2^20 nsec in 2^SHIFT_HZ ticks). |
| 822 | */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 823 | error2 = tk->ntp_error >> (NTP_SCALE_SHIFT + 22 - 2 * SHIFT_HZ); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 824 | error2 = abs(error2); |
| 825 | for (look_ahead = 0; error2 > 0; look_ahead++) |
| 826 | error2 >>= 2; |
| 827 | |
| 828 | /* |
| 829 | * Now calculate the error in (1 << look_ahead) ticks, but first |
| 830 | * remove the single look ahead already included in the error. |
| 831 | */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 832 | tick_error = ntp_tick_length() >> (tk->ntp_error_shift + 1); |
| 833 | tick_error -= tk->xtime_interval >> 1; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 834 | error = ((error - tick_error) >> look_ahead) + tick_error; |
| 835 | |
| 836 | /* Finally calculate the adjustment shift value. */ |
| 837 | i = *interval; |
| 838 | mult = 1; |
| 839 | if (error < 0) { |
| 840 | error = -error; |
| 841 | *interval = -*interval; |
| 842 | *offset = -*offset; |
| 843 | mult = -1; |
| 844 | } |
| 845 | for (adj = 0; error > i; adj++) |
| 846 | error >>= 1; |
| 847 | |
| 848 | *interval <<= adj; |
| 849 | *offset <<= adj; |
| 850 | return mult << adj; |
| 851 | } |
| 852 | |
| 853 | /* |
| 854 | * Adjust the multiplier to reduce the error value, |
| 855 | * this is optimized for the most common adjustments of -1,0,1, |
| 856 | * for other values we can do a bit more work. |
| 857 | */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 858 | static void timekeeping_adjust(struct timekeeper *tk, s64 offset) |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 859 | { |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 860 | s64 error, interval = tk->cycle_interval; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 861 | int adj; |
| 862 | |
John Stultz | c2bc111 | 2011-10-27 18:12:42 -0700 | [diff] [blame] | 863 | /* |
Jim Cromie | 88b28ad | 2012-03-14 21:28:56 -0600 | [diff] [blame] | 864 | * 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] | 865 | * an interval. |
| 866 | * |
| 867 | * First we shift it down from NTP_SHIFT to clocksource->shifted nsecs. |
| 868 | * |
| 869 | * 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] | 870 | * This "saves" dividing(shifting) interval twice, but keeps the |
| 871 | * (error > interval) comparison as still measuring if error is |
Jim Cromie | 88b28ad | 2012-03-14 21:28:56 -0600 | [diff] [blame] | 872 | * larger than half an interval. |
John Stultz | c2bc111 | 2011-10-27 18:12:42 -0700 | [diff] [blame] | 873 | * |
John Stultz | 3f86f28 | 2011-10-27 17:41:17 -0700 | [diff] [blame] | 874 | * Note: It does not "save" on aggravation when reading the code. |
John Stultz | c2bc111 | 2011-10-27 18:12:42 -0700 | [diff] [blame] | 875 | */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 876 | error = tk->ntp_error >> (tk->ntp_error_shift - 1); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 877 | if (error > interval) { |
John Stultz | c2bc111 | 2011-10-27 18:12:42 -0700 | [diff] [blame] | 878 | /* |
| 879 | * We now divide error by 4(via shift), which checks if |
Jim Cromie | 88b28ad | 2012-03-14 21:28:56 -0600 | [diff] [blame] | 880 | * the error is greater than twice the interval. |
John Stultz | c2bc111 | 2011-10-27 18:12:42 -0700 | [diff] [blame] | 881 | * If it is greater, we need a bigadjust, if its smaller, |
| 882 | * we can adjust by 1. |
| 883 | */ |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 884 | error >>= 2; |
John Stultz | c2bc111 | 2011-10-27 18:12:42 -0700 | [diff] [blame] | 885 | /* |
| 886 | * XXX - In update_wall_time, we round up to the next |
| 887 | * nanosecond, and store the amount rounded up into |
| 888 | * the error. This causes the likely below to be unlikely. |
| 889 | * |
John Stultz | 3f86f28 | 2011-10-27 17:41:17 -0700 | [diff] [blame] | 890 | * The proper fix is to avoid rounding up by using |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 891 | * the high precision tk->xtime_nsec instead of |
John Stultz | c2bc111 | 2011-10-27 18:12:42 -0700 | [diff] [blame] | 892 | * xtime.tv_nsec everywhere. Fixing this will take some |
| 893 | * time. |
| 894 | */ |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 895 | if (likely(error <= interval)) |
| 896 | adj = 1; |
| 897 | else |
Ingo Molnar | 1d17d17 | 2012-08-04 21:21:14 +0200 | [diff] [blame] | 898 | adj = timekeeping_bigadjust(tk, error, &interval, &offset); |
| 899 | } else { |
| 900 | if (error < -interval) { |
| 901 | /* See comment above, this is just switched for the negative */ |
| 902 | error >>= 2; |
| 903 | if (likely(error >= -interval)) { |
| 904 | adj = -1; |
| 905 | interval = -interval; |
| 906 | offset = -offset; |
| 907 | } else { |
| 908 | adj = timekeeping_bigadjust(tk, error, &interval, &offset); |
| 909 | } |
| 910 | } else { |
| 911 | goto out_adjust; |
| 912 | } |
| 913 | } |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 914 | |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 915 | if (unlikely(tk->clock->maxadj && |
| 916 | (tk->mult + adj > tk->clock->mult + tk->clock->maxadj))) { |
John Stultz | e919cfd | 2012-03-22 19:14:46 -0700 | [diff] [blame] | 917 | printk_once(KERN_WARNING |
| 918 | "Adjusting %s more than 11%% (%ld vs %ld)\n", |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 919 | tk->clock->name, (long)tk->mult + adj, |
| 920 | (long)tk->clock->mult + tk->clock->maxadj); |
John Stultz | e919cfd | 2012-03-22 19:14:46 -0700 | [diff] [blame] | 921 | } |
John Stultz | c2bc111 | 2011-10-27 18:12:42 -0700 | [diff] [blame] | 922 | /* |
| 923 | * So the following can be confusing. |
| 924 | * |
| 925 | * To keep things simple, lets assume adj == 1 for now. |
| 926 | * |
| 927 | * When adj != 1, remember that the interval and offset values |
| 928 | * have been appropriately scaled so the math is the same. |
| 929 | * |
| 930 | * The basic idea here is that we're increasing the multiplier |
| 931 | * by one, this causes the xtime_interval to be incremented by |
| 932 | * one cycle_interval. This is because: |
| 933 | * xtime_interval = cycle_interval * mult |
| 934 | * So if mult is being incremented by one: |
| 935 | * xtime_interval = cycle_interval * (mult + 1) |
| 936 | * Its the same as: |
| 937 | * xtime_interval = (cycle_interval * mult) + cycle_interval |
| 938 | * Which can be shortened to: |
| 939 | * xtime_interval += cycle_interval |
| 940 | * |
| 941 | * So offset stores the non-accumulated cycles. Thus the current |
| 942 | * time (in shifted nanoseconds) is: |
| 943 | * now = (offset * adj) + xtime_nsec |
| 944 | * Now, even though we're adjusting the clock frequency, we have |
| 945 | * to keep time consistent. In other words, we can't jump back |
| 946 | * in time, and we also want to avoid jumping forward in time. |
| 947 | * |
| 948 | * So given the same offset value, we need the time to be the same |
| 949 | * both before and after the freq adjustment. |
| 950 | * now = (offset * adj_1) + xtime_nsec_1 |
| 951 | * now = (offset * adj_2) + xtime_nsec_2 |
| 952 | * So: |
| 953 | * (offset * adj_1) + xtime_nsec_1 = |
| 954 | * (offset * adj_2) + xtime_nsec_2 |
| 955 | * And we know: |
| 956 | * adj_2 = adj_1 + 1 |
| 957 | * So: |
| 958 | * (offset * adj_1) + xtime_nsec_1 = |
| 959 | * (offset * (adj_1+1)) + xtime_nsec_2 |
| 960 | * (offset * adj_1) + xtime_nsec_1 = |
| 961 | * (offset * adj_1) + offset + xtime_nsec_2 |
| 962 | * Canceling the sides: |
| 963 | * xtime_nsec_1 = offset + xtime_nsec_2 |
| 964 | * Which gives us: |
| 965 | * xtime_nsec_2 = xtime_nsec_1 - offset |
| 966 | * Which simplfies to: |
| 967 | * xtime_nsec -= offset |
| 968 | * |
| 969 | * XXX - TODO: Doc ntp_error calculation. |
| 970 | */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 971 | tk->mult += adj; |
| 972 | tk->xtime_interval += interval; |
| 973 | tk->xtime_nsec -= offset; |
| 974 | tk->ntp_error -= (interval - offset) << tk->ntp_error_shift; |
John Stultz | 2a8c088 | 2012-07-13 01:21:56 -0400 | [diff] [blame] | 975 | |
Ingo Molnar | 1d17d17 | 2012-08-04 21:21:14 +0200 | [diff] [blame] | 976 | out_adjust: |
John Stultz | 2a8c088 | 2012-07-13 01:21:56 -0400 | [diff] [blame] | 977 | /* |
| 978 | * It may be possible that when we entered this function, xtime_nsec |
| 979 | * was very small. Further, if we're slightly speeding the clocksource |
| 980 | * in the code above, its possible the required corrective factor to |
| 981 | * xtime_nsec could cause it to underflow. |
| 982 | * |
| 983 | * Now, since we already accumulated the second, cannot simply roll |
| 984 | * the accumulated second back, since the NTP subsystem has been |
| 985 | * notified via second_overflow. So instead we push xtime_nsec forward |
| 986 | * by the amount we underflowed, and add that amount into the error. |
| 987 | * |
| 988 | * We'll correct this error next time through this function, when |
| 989 | * xtime_nsec is not as small. |
| 990 | */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 991 | if (unlikely((s64)tk->xtime_nsec < 0)) { |
| 992 | s64 neg = -(s64)tk->xtime_nsec; |
| 993 | tk->xtime_nsec = 0; |
| 994 | tk->ntp_error += neg << tk->ntp_error_shift; |
John Stultz | 2a8c088 | 2012-07-13 01:21:56 -0400 | [diff] [blame] | 995 | } |
| 996 | |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 997 | } |
| 998 | |
| 999 | /** |
John Stultz | 1f4f948 | 2012-07-13 01:21:54 -0400 | [diff] [blame] | 1000 | * accumulate_nsecs_to_secs - Accumulates nsecs into secs |
| 1001 | * |
| 1002 | * Helper function that accumulates a the nsecs greater then a second |
| 1003 | * from the xtime_nsec field to the xtime_secs field. |
| 1004 | * It also calls into the NTP code to handle leapsecond processing. |
| 1005 | * |
| 1006 | */ |
| 1007 | static inline void accumulate_nsecs_to_secs(struct timekeeper *tk) |
| 1008 | { |
| 1009 | u64 nsecps = (u64)NSEC_PER_SEC << tk->shift; |
| 1010 | |
| 1011 | while (tk->xtime_nsec >= nsecps) { |
| 1012 | int leap; |
| 1013 | |
| 1014 | tk->xtime_nsec -= nsecps; |
| 1015 | tk->xtime_sec++; |
| 1016 | |
| 1017 | /* Figure out if its a leap sec and apply if needed */ |
| 1018 | leap = second_overflow(tk->xtime_sec); |
John Stultz | 6d0ef90 | 2012-07-27 14:48:12 -0400 | [diff] [blame] | 1019 | if (unlikely(leap)) { |
| 1020 | struct timespec ts; |
John Stultz | 1f4f948 | 2012-07-13 01:21:54 -0400 | [diff] [blame] | 1021 | |
John Stultz | 6d0ef90 | 2012-07-27 14:48:12 -0400 | [diff] [blame] | 1022 | tk->xtime_sec += leap; |
| 1023 | |
| 1024 | ts.tv_sec = leap; |
| 1025 | ts.tv_nsec = 0; |
| 1026 | tk_set_wall_to_mono(tk, |
| 1027 | timespec_sub(tk->wall_to_monotonic, ts)); |
| 1028 | |
| 1029 | clock_was_set_delayed(); |
| 1030 | } |
John Stultz | 1f4f948 | 2012-07-13 01:21:54 -0400 | [diff] [blame] | 1031 | } |
| 1032 | } |
| 1033 | |
John Stultz | 1f4f948 | 2012-07-13 01:21:54 -0400 | [diff] [blame] | 1034 | /** |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1035 | * logarithmic_accumulation - shifted accumulation of cycles |
| 1036 | * |
| 1037 | * This functions accumulates a shifted interval of cycles into |
| 1038 | * into a shifted interval nanoseconds. Allows for O(log) accumulation |
| 1039 | * loop. |
| 1040 | * |
| 1041 | * Returns the unconsumed cycles. |
| 1042 | */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 1043 | static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset, |
| 1044 | u32 shift) |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1045 | { |
Jason Wessel | deda2e8 | 2010-08-09 14:20:09 -0700 | [diff] [blame] | 1046 | u64 raw_nsecs; |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1047 | |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 1048 | /* If the offset is smaller then a shifted interval, do nothing */ |
| 1049 | if (offset < tk->cycle_interval<<shift) |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1050 | return offset; |
| 1051 | |
| 1052 | /* Accumulate one shifted interval */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 1053 | offset -= tk->cycle_interval << shift; |
| 1054 | tk->clock->cycle_last += tk->cycle_interval << shift; |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1055 | |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 1056 | tk->xtime_nsec += tk->xtime_interval << shift; |
| 1057 | accumulate_nsecs_to_secs(tk); |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1058 | |
Jason Wessel | deda2e8 | 2010-08-09 14:20:09 -0700 | [diff] [blame] | 1059 | /* Accumulate raw time */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 1060 | raw_nsecs = tk->raw_interval << shift; |
| 1061 | raw_nsecs += tk->raw_time.tv_nsec; |
John Stultz | c7dcf87 | 2010-08-13 11:30:58 -0700 | [diff] [blame] | 1062 | if (raw_nsecs >= NSEC_PER_SEC) { |
| 1063 | u64 raw_secs = raw_nsecs; |
| 1064 | raw_nsecs = do_div(raw_secs, NSEC_PER_SEC); |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 1065 | tk->raw_time.tv_sec += raw_secs; |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1066 | } |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 1067 | tk->raw_time.tv_nsec = raw_nsecs; |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1068 | |
| 1069 | /* Accumulate error between NTP and clock interval */ |
John Stultz | f726a69 | 2012-07-13 01:21:57 -0400 | [diff] [blame] | 1070 | tk->ntp_error += ntp_tick_length() << shift; |
| 1071 | tk->ntp_error -= (tk->xtime_interval + tk->xtime_remainder) << |
| 1072 | (tk->ntp_error_shift + shift); |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1073 | |
| 1074 | return offset; |
| 1075 | } |
| 1076 | |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 1077 | /** |
| 1078 | * update_wall_time - Uses the current clocksource to increment the wall time |
| 1079 | * |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 1080 | */ |
Torben Hohn | 871cf1e | 2011-01-27 15:58:55 +0100 | [diff] [blame] | 1081 | static void update_wall_time(void) |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 1082 | { |
Martin Schwidefsky | 155ec60 | 2009-08-14 15:47:26 +0200 | [diff] [blame] | 1083 | struct clocksource *clock; |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1084 | struct timekeeper *tk = &timekeeper; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 1085 | cycle_t offset; |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1086 | int shift = 0, maxshift; |
John Stultz | 70471f2 | 2011-11-14 12:48:10 -0800 | [diff] [blame] | 1087 | unsigned long flags; |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 1088 | s64 remainder; |
John Stultz | 70471f2 | 2011-11-14 12:48:10 -0800 | [diff] [blame] | 1089 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1090 | write_seqlock_irqsave(&tk->lock, flags); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 1091 | |
| 1092 | /* Make sure we're fully resumed: */ |
| 1093 | if (unlikely(timekeeping_suspended)) |
John Stultz | 70471f2 | 2011-11-14 12:48:10 -0800 | [diff] [blame] | 1094 | goto out; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 1095 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1096 | clock = tk->clock; |
John Stultz | 592913e | 2010-07-13 17:56:20 -0700 | [diff] [blame] | 1097 | |
| 1098 | #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1099 | offset = tk->cycle_interval; |
John Stultz | 592913e | 2010-07-13 17:56:20 -0700 | [diff] [blame] | 1100 | #else |
| 1101 | offset = (clock->read(clock) - clock->cycle_last) & clock->mask; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 1102 | #endif |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 1103 | |
John Stultz | bf2ac31 | 2012-08-21 20:30:49 -0400 | [diff] [blame] | 1104 | /* Check if there's really nothing to do */ |
| 1105 | if (offset < tk->cycle_interval) |
| 1106 | goto out; |
| 1107 | |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1108 | /* |
| 1109 | * With NO_HZ we may have to accumulate many cycle_intervals |
| 1110 | * (think "ticks") worth of time at once. To do this efficiently, |
| 1111 | * we calculate the largest doubling multiple of cycle_intervals |
Jim Cromie | 88b28ad | 2012-03-14 21:28:56 -0600 | [diff] [blame] | 1112 | * that is smaller than the offset. We then accumulate that |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1113 | * chunk in one go, and then try to consume the next smaller |
| 1114 | * doubled multiple. |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 1115 | */ |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1116 | shift = ilog2(offset) - ilog2(tk->cycle_interval); |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1117 | shift = max(0, shift); |
Jim Cromie | 88b28ad | 2012-03-14 21:28:56 -0600 | [diff] [blame] | 1118 | /* Bound shift to one less than what overflows tick_length */ |
John Stultz | ea7cf49 | 2011-11-14 13:18:07 -0800 | [diff] [blame] | 1119 | maxshift = (64 - (ilog2(ntp_tick_length())+1)) - 1; |
john stultz | a092ff0 | 2009-10-02 16:17:53 -0700 | [diff] [blame] | 1120 | shift = min(shift, maxshift); |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1121 | while (offset >= tk->cycle_interval) { |
| 1122 | offset = logarithmic_accumulation(tk, offset, shift); |
| 1123 | if (offset < tk->cycle_interval<<shift) |
John Stultz | 830ec04 | 2010-03-18 14:47:30 -0700 | [diff] [blame] | 1124 | shift--; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 1125 | } |
| 1126 | |
| 1127 | /* correct the clock when NTP error is too big */ |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1128 | timekeeping_adjust(tk, offset); |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 1129 | |
john stultz | 6c9bacb | 2008-12-01 18:34:41 -0800 | [diff] [blame] | 1130 | |
John Stultz | 6a867a3 | 2010-04-06 14:30:51 -0700 | [diff] [blame] | 1131 | /* |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 1132 | * Store only full nanoseconds into xtime_nsec after rounding |
| 1133 | * it up and add the remainder to the error difference. |
| 1134 | * XXX - This is necessary to avoid small 1ns inconsistnecies caused |
| 1135 | * by truncating the remainder in vsyscalls. However, it causes |
| 1136 | * additional work to be done in timekeeping_adjust(). Once |
| 1137 | * the vsyscall implementations are converted to use xtime_nsec |
| 1138 | * (shifted nanoseconds), this can be killed. |
| 1139 | */ |
John Stultz | 6ea565a | 2012-08-21 20:30:48 -0400 | [diff] [blame] | 1140 | remainder = tk->xtime_nsec & ((1ULL << tk->shift) - 1); |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1141 | tk->xtime_nsec -= remainder; |
John Stultz | 6ea565a | 2012-08-21 20:30:48 -0400 | [diff] [blame] | 1142 | tk->xtime_nsec += 1ULL << tk->shift; |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1143 | tk->ntp_error += remainder << tk->ntp_error_shift; |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 1144 | |
John Stultz | 6a867a3 | 2010-04-06 14:30:51 -0700 | [diff] [blame] | 1145 | /* |
| 1146 | * Finally, make sure that after the rounding |
John Stultz | 1e75fa8 | 2012-07-13 01:21:53 -0400 | [diff] [blame] | 1147 | * xtime_nsec isn't larger than NSEC_PER_SEC |
John Stultz | 6a867a3 | 2010-04-06 14:30:51 -0700 | [diff] [blame] | 1148 | */ |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1149 | accumulate_nsecs_to_secs(tk); |
Linus Torvalds | 83f57a1 | 2009-12-22 14:10:37 -0800 | [diff] [blame] | 1150 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1151 | timekeeping_update(tk, false); |
John Stultz | 70471f2 | 2011-11-14 12:48:10 -0800 | [diff] [blame] | 1152 | |
| 1153 | out: |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1154 | write_sequnlock_irqrestore(&tk->lock, flags); |
John Stultz | 70471f2 | 2011-11-14 12:48:10 -0800 | [diff] [blame] | 1155 | |
john stultz | 8524070 | 2007-05-08 00:27:59 -0700 | [diff] [blame] | 1156 | } |
Tomas Janousek | 7c3f1a5 | 2007-07-15 23:39:41 -0700 | [diff] [blame] | 1157 | |
| 1158 | /** |
| 1159 | * getboottime - Return the real time of system boot. |
| 1160 | * @ts: pointer to the timespec to be set |
| 1161 | * |
John Stultz | abb3a4e | 2011-02-14 17:52:09 -0800 | [diff] [blame] | 1162 | * Returns the wall-time of boot in a timespec. |
Tomas Janousek | 7c3f1a5 | 2007-07-15 23:39:41 -0700 | [diff] [blame] | 1163 | * |
| 1164 | * This is based on the wall_to_monotonic offset and the total suspend |
| 1165 | * time. Calls to settimeofday will affect the value returned (which |
| 1166 | * basically means that however wrong your real time clock is at boot time, |
| 1167 | * you get the right time here). |
| 1168 | */ |
| 1169 | void getboottime(struct timespec *ts) |
| 1170 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1171 | struct timekeeper *tk = &timekeeper; |
Hiroshi Shimamoto | 36d4748 | 2009-08-25 15:08:30 +0900 | [diff] [blame] | 1172 | struct timespec boottime = { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1173 | .tv_sec = tk->wall_to_monotonic.tv_sec + |
| 1174 | tk->total_sleep_time.tv_sec, |
| 1175 | .tv_nsec = tk->wall_to_monotonic.tv_nsec + |
| 1176 | tk->total_sleep_time.tv_nsec |
Hiroshi Shimamoto | 36d4748 | 2009-08-25 15:08:30 +0900 | [diff] [blame] | 1177 | }; |
Martin Schwidefsky | d4f587c | 2009-08-14 15:47:31 +0200 | [diff] [blame] | 1178 | |
Martin Schwidefsky | d4f587c | 2009-08-14 15:47:31 +0200 | [diff] [blame] | 1179 | set_normalized_timespec(ts, -boottime.tv_sec, -boottime.tv_nsec); |
Tomas Janousek | 7c3f1a5 | 2007-07-15 23:39:41 -0700 | [diff] [blame] | 1180 | } |
Jason Wang | c93d89f | 2010-01-27 19:13:40 +0800 | [diff] [blame] | 1181 | EXPORT_SYMBOL_GPL(getboottime); |
Tomas Janousek | 7c3f1a5 | 2007-07-15 23:39:41 -0700 | [diff] [blame] | 1182 | |
John Stultz | abb3a4e | 2011-02-14 17:52:09 -0800 | [diff] [blame] | 1183 | /** |
| 1184 | * get_monotonic_boottime - Returns monotonic time since boot |
| 1185 | * @ts: pointer to the timespec to be set |
| 1186 | * |
| 1187 | * Returns the monotonic time since boot in a timespec. |
| 1188 | * |
| 1189 | * This is similar to CLOCK_MONTONIC/ktime_get_ts, but also |
| 1190 | * includes the time spent in suspend. |
| 1191 | */ |
| 1192 | void get_monotonic_boottime(struct timespec *ts) |
| 1193 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1194 | struct timekeeper *tk = &timekeeper; |
John Stultz | abb3a4e | 2011-02-14 17:52:09 -0800 | [diff] [blame] | 1195 | struct timespec tomono, sleep; |
John Stultz | ec145ba | 2012-09-11 19:26:03 -0400 | [diff] [blame] | 1196 | s64 nsec; |
John Stultz | abb3a4e | 2011-02-14 17:52:09 -0800 | [diff] [blame] | 1197 | unsigned int seq; |
John Stultz | abb3a4e | 2011-02-14 17:52:09 -0800 | [diff] [blame] | 1198 | |
| 1199 | WARN_ON(timekeeping_suspended); |
| 1200 | |
| 1201 | do { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1202 | seq = read_seqbegin(&tk->lock); |
| 1203 | ts->tv_sec = tk->xtime_sec; |
John Stultz | ec145ba | 2012-09-11 19:26:03 -0400 | [diff] [blame] | 1204 | nsec = timekeeping_get_ns(tk); |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1205 | tomono = tk->wall_to_monotonic; |
| 1206 | sleep = tk->total_sleep_time; |
John Stultz | abb3a4e | 2011-02-14 17:52:09 -0800 | [diff] [blame] | 1207 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1208 | } while (read_seqretry(&tk->lock, seq)); |
John Stultz | abb3a4e | 2011-02-14 17:52:09 -0800 | [diff] [blame] | 1209 | |
John Stultz | ec145ba | 2012-09-11 19:26:03 -0400 | [diff] [blame] | 1210 | ts->tv_sec += tomono.tv_sec + sleep.tv_sec; |
| 1211 | ts->tv_nsec = 0; |
| 1212 | timespec_add_ns(ts, nsec + tomono.tv_nsec + sleep.tv_nsec); |
John Stultz | abb3a4e | 2011-02-14 17:52:09 -0800 | [diff] [blame] | 1213 | } |
| 1214 | EXPORT_SYMBOL_GPL(get_monotonic_boottime); |
| 1215 | |
| 1216 | /** |
| 1217 | * ktime_get_boottime - Returns monotonic time since boot in a ktime |
| 1218 | * |
| 1219 | * Returns the monotonic time since boot in a ktime |
| 1220 | * |
| 1221 | * This is similar to CLOCK_MONTONIC/ktime_get, but also |
| 1222 | * includes the time spent in suspend. |
| 1223 | */ |
| 1224 | ktime_t ktime_get_boottime(void) |
| 1225 | { |
| 1226 | struct timespec ts; |
| 1227 | |
| 1228 | get_monotonic_boottime(&ts); |
| 1229 | return timespec_to_ktime(ts); |
| 1230 | } |
| 1231 | EXPORT_SYMBOL_GPL(ktime_get_boottime); |
| 1232 | |
Tomas Janousek | 7c3f1a5 | 2007-07-15 23:39:41 -0700 | [diff] [blame] | 1233 | /** |
| 1234 | * monotonic_to_bootbased - Convert the monotonic time to boot based. |
| 1235 | * @ts: pointer to the timespec to be converted |
| 1236 | */ |
| 1237 | void monotonic_to_bootbased(struct timespec *ts) |
| 1238 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1239 | struct timekeeper *tk = &timekeeper; |
| 1240 | |
| 1241 | *ts = timespec_add(*ts, tk->total_sleep_time); |
Tomas Janousek | 7c3f1a5 | 2007-07-15 23:39:41 -0700 | [diff] [blame] | 1242 | } |
Jason Wang | c93d89f | 2010-01-27 19:13:40 +0800 | [diff] [blame] | 1243 | EXPORT_SYMBOL_GPL(monotonic_to_bootbased); |
john stultz | 2c6b47d | 2007-07-24 17:47:43 -0700 | [diff] [blame] | 1244 | |
john stultz | 17c38b7 | 2007-07-24 18:38:34 -0700 | [diff] [blame] | 1245 | unsigned long get_seconds(void) |
| 1246 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1247 | struct timekeeper *tk = &timekeeper; |
| 1248 | |
| 1249 | return tk->xtime_sec; |
john stultz | 17c38b7 | 2007-07-24 18:38:34 -0700 | [diff] [blame] | 1250 | } |
| 1251 | EXPORT_SYMBOL(get_seconds); |
| 1252 | |
john stultz | da15cfd | 2009-08-19 19:13:34 -0700 | [diff] [blame] | 1253 | struct timespec __current_kernel_time(void) |
| 1254 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1255 | struct timekeeper *tk = &timekeeper; |
| 1256 | |
| 1257 | return tk_xtime(tk); |
john stultz | da15cfd | 2009-08-19 19:13:34 -0700 | [diff] [blame] | 1258 | } |
john stultz | 17c38b7 | 2007-07-24 18:38:34 -0700 | [diff] [blame] | 1259 | |
john stultz | 2c6b47d | 2007-07-24 17:47:43 -0700 | [diff] [blame] | 1260 | struct timespec current_kernel_time(void) |
| 1261 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1262 | struct timekeeper *tk = &timekeeper; |
john stultz | 2c6b47d | 2007-07-24 17:47:43 -0700 | [diff] [blame] | 1263 | struct timespec now; |
| 1264 | unsigned long seq; |
| 1265 | |
| 1266 | do { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1267 | seq = read_seqbegin(&tk->lock); |
Linus Torvalds | 83f57a1 | 2009-12-22 14:10:37 -0800 | [diff] [blame] | 1268 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1269 | now = tk_xtime(tk); |
| 1270 | } while (read_seqretry(&tk->lock, seq)); |
john stultz | 2c6b47d | 2007-07-24 17:47:43 -0700 | [diff] [blame] | 1271 | |
| 1272 | return now; |
| 1273 | } |
john stultz | 2c6b47d | 2007-07-24 17:47:43 -0700 | [diff] [blame] | 1274 | EXPORT_SYMBOL(current_kernel_time); |
john stultz | da15cfd | 2009-08-19 19:13:34 -0700 | [diff] [blame] | 1275 | |
| 1276 | struct timespec get_monotonic_coarse(void) |
| 1277 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1278 | struct timekeeper *tk = &timekeeper; |
john stultz | da15cfd | 2009-08-19 19:13:34 -0700 | [diff] [blame] | 1279 | struct timespec now, mono; |
| 1280 | unsigned long seq; |
| 1281 | |
| 1282 | do { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1283 | seq = read_seqbegin(&tk->lock); |
Linus Torvalds | 83f57a1 | 2009-12-22 14:10:37 -0800 | [diff] [blame] | 1284 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1285 | now = tk_xtime(tk); |
| 1286 | mono = tk->wall_to_monotonic; |
| 1287 | } while (read_seqretry(&tk->lock, seq)); |
john stultz | da15cfd | 2009-08-19 19:13:34 -0700 | [diff] [blame] | 1288 | |
| 1289 | set_normalized_timespec(&now, now.tv_sec + mono.tv_sec, |
| 1290 | now.tv_nsec + mono.tv_nsec); |
| 1291 | return now; |
| 1292 | } |
Torben Hohn | 871cf1e | 2011-01-27 15:58:55 +0100 | [diff] [blame] | 1293 | |
| 1294 | /* |
| 1295 | * The 64-bit jiffies value is not atomic - you MUST NOT read it |
| 1296 | * without sampling the sequence number in xtime_lock. |
| 1297 | * jiffies is defined in the linker script... |
| 1298 | */ |
| 1299 | void do_timer(unsigned long ticks) |
| 1300 | { |
| 1301 | jiffies_64 += ticks; |
| 1302 | update_wall_time(); |
| 1303 | calc_global_load(ticks); |
| 1304 | } |
Torben Hohn | 48cf76f7 | 2011-01-27 15:59:05 +0100 | [diff] [blame] | 1305 | |
| 1306 | /** |
John Stultz | 314ac37 | 2011-02-14 18:43:08 -0800 | [diff] [blame] | 1307 | * get_xtime_and_monotonic_and_sleep_offset() - get xtime, wall_to_monotonic, |
| 1308 | * and sleep offsets. |
Torben Hohn | 48cf76f7 | 2011-01-27 15:59:05 +0100 | [diff] [blame] | 1309 | * @xtim: pointer to timespec to be set with xtime |
| 1310 | * @wtom: pointer to timespec to be set with wall_to_monotonic |
John Stultz | 314ac37 | 2011-02-14 18:43:08 -0800 | [diff] [blame] | 1311 | * @sleep: pointer to timespec to be set with time in suspend |
Torben Hohn | 48cf76f7 | 2011-01-27 15:59:05 +0100 | [diff] [blame] | 1312 | */ |
John Stultz | 314ac37 | 2011-02-14 18:43:08 -0800 | [diff] [blame] | 1313 | void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim, |
| 1314 | struct timespec *wtom, struct timespec *sleep) |
Torben Hohn | 48cf76f7 | 2011-01-27 15:59:05 +0100 | [diff] [blame] | 1315 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1316 | struct timekeeper *tk = &timekeeper; |
Torben Hohn | 48cf76f7 | 2011-01-27 15:59:05 +0100 | [diff] [blame] | 1317 | unsigned long seq; |
| 1318 | |
| 1319 | do { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1320 | seq = read_seqbegin(&tk->lock); |
| 1321 | *xtim = tk_xtime(tk); |
| 1322 | *wtom = tk->wall_to_monotonic; |
| 1323 | *sleep = tk->total_sleep_time; |
| 1324 | } while (read_seqretry(&tk->lock, seq)); |
Torben Hohn | 48cf76f7 | 2011-01-27 15:59:05 +0100 | [diff] [blame] | 1325 | } |
Torben Hohn | f0af911a9 | 2011-01-27 15:59:10 +0100 | [diff] [blame] | 1326 | |
Thomas Gleixner | f6c06ab | 2012-07-10 18:43:24 -0400 | [diff] [blame] | 1327 | #ifdef CONFIG_HIGH_RES_TIMERS |
| 1328 | /** |
| 1329 | * ktime_get_update_offsets - hrtimer helper |
| 1330 | * @offs_real: pointer to storage for monotonic -> realtime offset |
| 1331 | * @offs_boot: pointer to storage for monotonic -> boottime offset |
| 1332 | * |
| 1333 | * Returns current monotonic time and updates the offsets |
| 1334 | * Called from hrtimer_interupt() or retrigger_next_event() |
| 1335 | */ |
| 1336 | ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot) |
| 1337 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1338 | struct timekeeper *tk = &timekeeper; |
Thomas Gleixner | f6c06ab | 2012-07-10 18:43:24 -0400 | [diff] [blame] | 1339 | ktime_t now; |
| 1340 | unsigned int seq; |
| 1341 | u64 secs, nsecs; |
| 1342 | |
| 1343 | do { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1344 | seq = read_seqbegin(&tk->lock); |
Thomas Gleixner | f6c06ab | 2012-07-10 18:43:24 -0400 | [diff] [blame] | 1345 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1346 | secs = tk->xtime_sec; |
| 1347 | nsecs = timekeeping_get_ns(tk); |
Thomas Gleixner | f6c06ab | 2012-07-10 18:43:24 -0400 | [diff] [blame] | 1348 | |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1349 | *offs_real = tk->offs_real; |
| 1350 | *offs_boot = tk->offs_boot; |
| 1351 | } while (read_seqretry(&tk->lock, seq)); |
Thomas Gleixner | f6c06ab | 2012-07-10 18:43:24 -0400 | [diff] [blame] | 1352 | |
| 1353 | now = ktime_add_ns(ktime_set(secs, 0), nsecs); |
| 1354 | now = ktime_sub(now, *offs_real); |
| 1355 | return now; |
| 1356 | } |
| 1357 | #endif |
| 1358 | |
Torben Hohn | f0af911a9 | 2011-01-27 15:59:10 +0100 | [diff] [blame] | 1359 | /** |
Thomas Gleixner | 99ee531 | 2011-04-27 14:16:42 +0200 | [diff] [blame] | 1360 | * ktime_get_monotonic_offset() - get wall_to_monotonic in ktime_t format |
| 1361 | */ |
| 1362 | ktime_t ktime_get_monotonic_offset(void) |
| 1363 | { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1364 | struct timekeeper *tk = &timekeeper; |
Thomas Gleixner | 99ee531 | 2011-04-27 14:16:42 +0200 | [diff] [blame] | 1365 | unsigned long seq; |
| 1366 | struct timespec wtom; |
| 1367 | |
| 1368 | do { |
John Stultz | 4e250fd | 2012-07-27 14:48:13 -0400 | [diff] [blame] | 1369 | seq = read_seqbegin(&tk->lock); |
| 1370 | wtom = tk->wall_to_monotonic; |
| 1371 | } while (read_seqretry(&tk->lock, seq)); |
John Stultz | 70471f2 | 2011-11-14 12:48:10 -0800 | [diff] [blame] | 1372 | |
Thomas Gleixner | 99ee531 | 2011-04-27 14:16:42 +0200 | [diff] [blame] | 1373 | return timespec_to_ktime(wtom); |
| 1374 | } |
John Stultz | a80b83b | 2012-02-03 00:19:07 -0800 | [diff] [blame] | 1375 | EXPORT_SYMBOL_GPL(ktime_get_monotonic_offset); |
| 1376 | |
Thomas Gleixner | 99ee531 | 2011-04-27 14:16:42 +0200 | [diff] [blame] | 1377 | /** |
Torben Hohn | f0af911a9 | 2011-01-27 15:59:10 +0100 | [diff] [blame] | 1378 | * xtime_update() - advances the timekeeping infrastructure |
| 1379 | * @ticks: number of ticks, that have elapsed since the last call. |
| 1380 | * |
| 1381 | * Must be called with interrupts disabled. |
| 1382 | */ |
| 1383 | void xtime_update(unsigned long ticks) |
| 1384 | { |
| 1385 | write_seqlock(&xtime_lock); |
| 1386 | do_timer(ticks); |
| 1387 | write_sequnlock(&xtime_lock); |
| 1388 | } |