Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1 | /* |
| 2 | * linux/kernel/hrtimer.c |
| 3 | * |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 4 | * Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de> |
Thomas Gleixner | 79bf2bb | 2007-02-16 01:28:03 -0800 | [diff] [blame] | 5 | * Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 6 | * Copyright(C) 2006-2007 Timesys Corp., Thomas Gleixner |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 7 | * |
| 8 | * High-resolution kernel timers |
| 9 | * |
| 10 | * In contrast to the low-resolution timeout API implemented in |
| 11 | * kernel/timer.c, hrtimers provide finer resolution and accuracy |
| 12 | * depending on system configuration and capabilities. |
| 13 | * |
| 14 | * These timers are currently used for: |
| 15 | * - itimers |
| 16 | * - POSIX timers |
| 17 | * - nanosleep |
| 18 | * - precise in-kernel timing |
| 19 | * |
| 20 | * Started by: Thomas Gleixner and Ingo Molnar |
| 21 | * |
| 22 | * Credits: |
| 23 | * based on kernel/timer.c |
| 24 | * |
Thomas Gleixner | 66188fa | 2006-02-01 03:05:13 -0800 | [diff] [blame] | 25 | * Help, testing, suggestions, bugfixes, improvements were |
| 26 | * provided by: |
| 27 | * |
| 28 | * George Anzinger, Andrew Morton, Steven Rostedt, Roman Zippel |
| 29 | * et. al. |
| 30 | * |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 31 | * For licencing details see kernel-base/COPYING |
| 32 | */ |
| 33 | |
| 34 | #include <linux/cpu.h> |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 35 | #include <linux/irq.h> |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 36 | #include <linux/module.h> |
| 37 | #include <linux/percpu.h> |
| 38 | #include <linux/hrtimer.h> |
| 39 | #include <linux/notifier.h> |
| 40 | #include <linux/syscalls.h> |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 41 | #include <linux/kallsyms.h> |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 42 | #include <linux/interrupt.h> |
Thomas Gleixner | 79bf2bb | 2007-02-16 01:28:03 -0800 | [diff] [blame] | 43 | #include <linux/tick.h> |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 44 | #include <linux/seq_file.h> |
| 45 | #include <linux/err.h> |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 46 | |
| 47 | #include <asm/uaccess.h> |
| 48 | |
| 49 | /** |
| 50 | * ktime_get - get the monotonic time in ktime_t format |
| 51 | * |
| 52 | * returns the time in ktime_t format |
| 53 | */ |
Thomas Gleixner | d316c57 | 2007-02-16 01:28:00 -0800 | [diff] [blame] | 54 | ktime_t ktime_get(void) |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 55 | { |
| 56 | struct timespec now; |
| 57 | |
| 58 | ktime_get_ts(&now); |
| 59 | |
| 60 | return timespec_to_ktime(now); |
| 61 | } |
Patrick McHardy | 641b9e0 | 2007-03-16 01:18:42 -0700 | [diff] [blame] | 62 | EXPORT_SYMBOL_GPL(ktime_get); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 63 | |
| 64 | /** |
| 65 | * ktime_get_real - get the real (wall-) time in ktime_t format |
| 66 | * |
| 67 | * returns the time in ktime_t format |
| 68 | */ |
Thomas Gleixner | d316c57 | 2007-02-16 01:28:00 -0800 | [diff] [blame] | 69 | ktime_t ktime_get_real(void) |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 70 | { |
| 71 | struct timespec now; |
| 72 | |
| 73 | getnstimeofday(&now); |
| 74 | |
| 75 | return timespec_to_ktime(now); |
| 76 | } |
| 77 | |
| 78 | EXPORT_SYMBOL_GPL(ktime_get_real); |
| 79 | |
| 80 | /* |
| 81 | * The timer bases: |
George Anzinger | 7978672c | 2006-02-01 03:05:11 -0800 | [diff] [blame] | 82 | * |
| 83 | * Note: If we want to add new timer bases, we have to skip the two |
| 84 | * clock ids captured by the cpu-timers. We do this by holding empty |
| 85 | * entries rather than doing math adjustment of the clock ids. |
| 86 | * This ensures that we capture erroneous accesses to these clock ids |
| 87 | * rather than moving them into the range of valid clock id's. |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 88 | */ |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 89 | DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) = |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 90 | { |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 91 | |
| 92 | .clock_base = |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 93 | { |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 94 | { |
| 95 | .index = CLOCK_REALTIME, |
| 96 | .get_time = &ktime_get_real, |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 97 | .resolution = KTIME_LOW_RES, |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 98 | }, |
| 99 | { |
| 100 | .index = CLOCK_MONOTONIC, |
| 101 | .get_time = &ktime_get, |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 102 | .resolution = KTIME_LOW_RES, |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 103 | }, |
| 104 | } |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 105 | }; |
| 106 | |
| 107 | /** |
| 108 | * ktime_get_ts - get the monotonic clock in timespec format |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 109 | * @ts: pointer to timespec variable |
| 110 | * |
| 111 | * The function calculates the monotonic clock from the realtime |
| 112 | * clock and the wall_to_monotonic offset and stores the result |
Robert P. J. Day | 72fd4a3 | 2007-02-10 01:45:59 -0800 | [diff] [blame] | 113 | * in normalized timespec format in the variable pointed to by @ts. |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 114 | */ |
| 115 | void ktime_get_ts(struct timespec *ts) |
| 116 | { |
| 117 | struct timespec tomono; |
| 118 | unsigned long seq; |
| 119 | |
| 120 | do { |
| 121 | seq = read_seqbegin(&xtime_lock); |
| 122 | getnstimeofday(ts); |
| 123 | tomono = wall_to_monotonic; |
| 124 | |
| 125 | } while (read_seqretry(&xtime_lock, seq)); |
| 126 | |
| 127 | set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec, |
| 128 | ts->tv_nsec + tomono.tv_nsec); |
| 129 | } |
Matt Helsley | 69778e3 | 2006-01-09 20:52:39 -0800 | [diff] [blame] | 130 | EXPORT_SYMBOL_GPL(ktime_get_ts); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 131 | |
| 132 | /* |
Thomas Gleixner | 92127c7 | 2006-03-26 01:38:05 -0800 | [diff] [blame] | 133 | * Get the coarse grained time at the softirq based on xtime and |
| 134 | * wall_to_monotonic. |
| 135 | */ |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 136 | static void hrtimer_get_softirq_time(struct hrtimer_cpu_base *base) |
Thomas Gleixner | 92127c7 | 2006-03-26 01:38:05 -0800 | [diff] [blame] | 137 | { |
| 138 | ktime_t xtim, tomono; |
Thomas Gleixner | ad28d94 | 2007-03-16 13:38:21 -0800 | [diff] [blame] | 139 | struct timespec xts, tom; |
Thomas Gleixner | 92127c7 | 2006-03-26 01:38:05 -0800 | [diff] [blame] | 140 | unsigned long seq; |
| 141 | |
| 142 | do { |
| 143 | seq = read_seqbegin(&xtime_lock); |
john stultz | 2c6b47d | 2007-07-24 17:47:43 -0700 | [diff] [blame] | 144 | xts = current_kernel_time(); |
Thomas Gleixner | ad28d94 | 2007-03-16 13:38:21 -0800 | [diff] [blame] | 145 | tom = wall_to_monotonic; |
Thomas Gleixner | 92127c7 | 2006-03-26 01:38:05 -0800 | [diff] [blame] | 146 | } while (read_seqretry(&xtime_lock, seq)); |
| 147 | |
john stultz | f4304ab | 2007-02-16 01:27:26 -0800 | [diff] [blame] | 148 | xtim = timespec_to_ktime(xts); |
Thomas Gleixner | ad28d94 | 2007-03-16 13:38:21 -0800 | [diff] [blame] | 149 | tomono = timespec_to_ktime(tom); |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 150 | base->clock_base[CLOCK_REALTIME].softirq_time = xtim; |
| 151 | base->clock_base[CLOCK_MONOTONIC].softirq_time = |
| 152 | ktime_add(xtim, tomono); |
Thomas Gleixner | 92127c7 | 2006-03-26 01:38:05 -0800 | [diff] [blame] | 153 | } |
| 154 | |
| 155 | /* |
Thomas Gleixner | 303e967 | 2007-02-16 01:27:51 -0800 | [diff] [blame] | 156 | * Helper function to check, whether the timer is running the callback |
| 157 | * function |
| 158 | */ |
| 159 | static inline int hrtimer_callback_running(struct hrtimer *timer) |
| 160 | { |
| 161 | return timer->state & HRTIMER_STATE_CALLBACK; |
| 162 | } |
| 163 | |
| 164 | /* |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 165 | * Functions and macros which are different for UP/SMP systems are kept in a |
| 166 | * single place |
| 167 | */ |
| 168 | #ifdef CONFIG_SMP |
| 169 | |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 170 | /* |
| 171 | * We are using hashed locking: holding per_cpu(hrtimer_bases)[n].lock |
| 172 | * means that all timers which are tied to this base via timer->base are |
| 173 | * locked, and the base itself is locked too. |
| 174 | * |
| 175 | * So __run_timers/migrate_timers can safely modify all timers which could |
| 176 | * be found on the lists/queues. |
| 177 | * |
| 178 | * When the timer's base is locked, and the timer removed from list, it is |
| 179 | * possible to set timer->base = NULL and drop the lock: the timer remains |
| 180 | * locked. |
| 181 | */ |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 182 | static |
| 183 | struct hrtimer_clock_base *lock_hrtimer_base(const struct hrtimer *timer, |
| 184 | unsigned long *flags) |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 185 | { |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 186 | struct hrtimer_clock_base *base; |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 187 | |
| 188 | for (;;) { |
| 189 | base = timer->base; |
| 190 | if (likely(base != NULL)) { |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 191 | spin_lock_irqsave(&base->cpu_base->lock, *flags); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 192 | if (likely(base == timer->base)) |
| 193 | return base; |
| 194 | /* The timer has migrated to another CPU: */ |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 195 | spin_unlock_irqrestore(&base->cpu_base->lock, *flags); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 196 | } |
| 197 | cpu_relax(); |
| 198 | } |
| 199 | } |
| 200 | |
| 201 | /* |
| 202 | * Switch the timer base to the current CPU when possible. |
| 203 | */ |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 204 | static inline struct hrtimer_clock_base * |
| 205 | switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_clock_base *base) |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 206 | { |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 207 | struct hrtimer_clock_base *new_base; |
| 208 | struct hrtimer_cpu_base *new_cpu_base; |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 209 | |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 210 | new_cpu_base = &__get_cpu_var(hrtimer_bases); |
| 211 | new_base = &new_cpu_base->clock_base[base->index]; |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 212 | |
| 213 | if (base != new_base) { |
| 214 | /* |
| 215 | * We are trying to schedule the timer on the local CPU. |
| 216 | * However we can't change timer's base while it is running, |
| 217 | * so we keep it on the same CPU. No hassle vs. reprogramming |
| 218 | * the event source in the high resolution case. The softirq |
| 219 | * code will take care of this when the timer function has |
| 220 | * completed. There is no conflict as we hold the lock until |
| 221 | * the timer is enqueued. |
| 222 | */ |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 223 | if (unlikely(hrtimer_callback_running(timer))) |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 224 | return base; |
| 225 | |
| 226 | /* See the comment in lock_timer_base() */ |
| 227 | timer->base = NULL; |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 228 | spin_unlock(&base->cpu_base->lock); |
| 229 | spin_lock(&new_base->cpu_base->lock); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 230 | timer->base = new_base; |
| 231 | } |
| 232 | return new_base; |
| 233 | } |
| 234 | |
| 235 | #else /* CONFIG_SMP */ |
| 236 | |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 237 | static inline struct hrtimer_clock_base * |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 238 | lock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags) |
| 239 | { |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 240 | struct hrtimer_clock_base *base = timer->base; |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 241 | |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 242 | spin_lock_irqsave(&base->cpu_base->lock, *flags); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 243 | |
| 244 | return base; |
| 245 | } |
| 246 | |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 247 | # define switch_hrtimer_base(t, b) (b) |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 248 | |
| 249 | #endif /* !CONFIG_SMP */ |
| 250 | |
| 251 | /* |
| 252 | * Functions for the union type storage format of ktime_t which are |
| 253 | * too large for inlining: |
| 254 | */ |
| 255 | #if BITS_PER_LONG < 64 |
| 256 | # ifndef CONFIG_KTIME_SCALAR |
| 257 | /** |
| 258 | * ktime_add_ns - Add a scalar nanoseconds value to a ktime_t variable |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 259 | * @kt: addend |
| 260 | * @nsec: the scalar nsec value to add |
| 261 | * |
| 262 | * Returns the sum of kt and nsec in ktime_t format |
| 263 | */ |
| 264 | ktime_t ktime_add_ns(const ktime_t kt, u64 nsec) |
| 265 | { |
| 266 | ktime_t tmp; |
| 267 | |
| 268 | if (likely(nsec < NSEC_PER_SEC)) { |
| 269 | tmp.tv64 = nsec; |
| 270 | } else { |
| 271 | unsigned long rem = do_div(nsec, NSEC_PER_SEC); |
| 272 | |
| 273 | tmp = ktime_set((long)nsec, rem); |
| 274 | } |
| 275 | |
| 276 | return ktime_add(kt, tmp); |
| 277 | } |
David Howells | b8b8fd2 | 2007-04-27 15:31:24 -0700 | [diff] [blame] | 278 | |
| 279 | EXPORT_SYMBOL_GPL(ktime_add_ns); |
Arnaldo Carvalho de Melo | a272378 | 2007-08-19 17:16:05 -0700 | [diff] [blame] | 280 | |
| 281 | /** |
| 282 | * ktime_sub_ns - Subtract a scalar nanoseconds value from a ktime_t variable |
| 283 | * @kt: minuend |
| 284 | * @nsec: the scalar nsec value to subtract |
| 285 | * |
| 286 | * Returns the subtraction of @nsec from @kt in ktime_t format |
| 287 | */ |
| 288 | ktime_t ktime_sub_ns(const ktime_t kt, u64 nsec) |
| 289 | { |
| 290 | ktime_t tmp; |
| 291 | |
| 292 | if (likely(nsec < NSEC_PER_SEC)) { |
| 293 | tmp.tv64 = nsec; |
| 294 | } else { |
| 295 | unsigned long rem = do_div(nsec, NSEC_PER_SEC); |
| 296 | |
| 297 | tmp = ktime_set((long)nsec, rem); |
| 298 | } |
| 299 | |
| 300 | return ktime_sub(kt, tmp); |
| 301 | } |
| 302 | |
| 303 | EXPORT_SYMBOL_GPL(ktime_sub_ns); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 304 | # endif /* !CONFIG_KTIME_SCALAR */ |
| 305 | |
| 306 | /* |
| 307 | * Divide a ktime value by a nanosecond value |
| 308 | */ |
Davide Libenzi | 4d672e7a | 2008-02-04 22:27:26 -0800 | [diff] [blame] | 309 | u64 ktime_divns(const ktime_t kt, s64 div) |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 310 | { |
| 311 | u64 dclc, inc, dns; |
| 312 | int sft = 0; |
| 313 | |
| 314 | dclc = dns = ktime_to_ns(kt); |
| 315 | inc = div; |
| 316 | /* Make sure the divisor is less than 2^32: */ |
| 317 | while (div >> 32) { |
| 318 | sft++; |
| 319 | div >>= 1; |
| 320 | } |
| 321 | dclc >>= sft; |
| 322 | do_div(dclc, (unsigned long) div); |
| 323 | |
Davide Libenzi | 4d672e7a | 2008-02-04 22:27:26 -0800 | [diff] [blame] | 324 | return dclc; |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 325 | } |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 326 | #endif /* BITS_PER_LONG >= 64 */ |
| 327 | |
Peter Zijlstra | d3d7445 | 2008-01-25 21:08:31 +0100 | [diff] [blame] | 328 | /* |
| 329 | * Check, whether the timer is on the callback pending list |
| 330 | */ |
| 331 | static inline int hrtimer_cb_pending(const struct hrtimer *timer) |
| 332 | { |
| 333 | return timer->state & HRTIMER_STATE_PENDING; |
| 334 | } |
| 335 | |
| 336 | /* |
| 337 | * Remove a timer from the callback pending list |
| 338 | */ |
| 339 | static inline void hrtimer_remove_cb_pending(struct hrtimer *timer) |
| 340 | { |
| 341 | list_del_init(&timer->cb_entry); |
| 342 | } |
| 343 | |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 344 | /* High resolution timer related functions */ |
| 345 | #ifdef CONFIG_HIGH_RES_TIMERS |
| 346 | |
| 347 | /* |
| 348 | * High resolution timer enabled ? |
| 349 | */ |
| 350 | static int hrtimer_hres_enabled __read_mostly = 1; |
| 351 | |
| 352 | /* |
| 353 | * Enable / Disable high resolution mode |
| 354 | */ |
| 355 | static int __init setup_hrtimer_hres(char *str) |
| 356 | { |
| 357 | if (!strcmp(str, "off")) |
| 358 | hrtimer_hres_enabled = 0; |
| 359 | else if (!strcmp(str, "on")) |
| 360 | hrtimer_hres_enabled = 1; |
| 361 | else |
| 362 | return 0; |
| 363 | return 1; |
| 364 | } |
| 365 | |
| 366 | __setup("highres=", setup_hrtimer_hres); |
| 367 | |
| 368 | /* |
| 369 | * hrtimer_high_res_enabled - query, if the highres mode is enabled |
| 370 | */ |
| 371 | static inline int hrtimer_is_hres_enabled(void) |
| 372 | { |
| 373 | return hrtimer_hres_enabled; |
| 374 | } |
| 375 | |
| 376 | /* |
| 377 | * Is the high resolution mode active ? |
| 378 | */ |
| 379 | static inline int hrtimer_hres_active(void) |
| 380 | { |
| 381 | return __get_cpu_var(hrtimer_bases).hres_active; |
| 382 | } |
| 383 | |
| 384 | /* |
| 385 | * Reprogram the event source with checking both queues for the |
| 386 | * next event |
| 387 | * Called with interrupts disabled and base->lock held |
| 388 | */ |
| 389 | static void hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base) |
| 390 | { |
| 391 | int i; |
| 392 | struct hrtimer_clock_base *base = cpu_base->clock_base; |
| 393 | ktime_t expires; |
| 394 | |
| 395 | cpu_base->expires_next.tv64 = KTIME_MAX; |
| 396 | |
| 397 | for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) { |
| 398 | struct hrtimer *timer; |
| 399 | |
| 400 | if (!base->first) |
| 401 | continue; |
| 402 | timer = rb_entry(base->first, struct hrtimer, node); |
| 403 | expires = ktime_sub(timer->expires, base->offset); |
| 404 | if (expires.tv64 < cpu_base->expires_next.tv64) |
| 405 | cpu_base->expires_next = expires; |
| 406 | } |
| 407 | |
| 408 | if (cpu_base->expires_next.tv64 != KTIME_MAX) |
| 409 | tick_program_event(cpu_base->expires_next, 1); |
| 410 | } |
| 411 | |
| 412 | /* |
| 413 | * Shared reprogramming for clock_realtime and clock_monotonic |
| 414 | * |
| 415 | * When a timer is enqueued and expires earlier than the already enqueued |
| 416 | * timers, we have to check, whether it expires earlier than the timer for |
| 417 | * which the clock event device was armed. |
| 418 | * |
| 419 | * Called with interrupts disabled and base->cpu_base.lock held |
| 420 | */ |
| 421 | static int hrtimer_reprogram(struct hrtimer *timer, |
| 422 | struct hrtimer_clock_base *base) |
| 423 | { |
| 424 | ktime_t *expires_next = &__get_cpu_var(hrtimer_bases).expires_next; |
| 425 | ktime_t expires = ktime_sub(timer->expires, base->offset); |
| 426 | int res; |
| 427 | |
| 428 | /* |
| 429 | * When the callback is running, we do not reprogram the clock event |
| 430 | * device. The timer callback is either running on a different CPU or |
Robert P. J. Day | 3a4fa0a | 2007-10-19 23:10:43 +0200 | [diff] [blame] | 431 | * the callback is executed in the hrtimer_interrupt context. The |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 432 | * reprogramming is handled either by the softirq, which called the |
| 433 | * callback or at the end of the hrtimer_interrupt. |
| 434 | */ |
| 435 | if (hrtimer_callback_running(timer)) |
| 436 | return 0; |
| 437 | |
| 438 | if (expires.tv64 >= expires_next->tv64) |
| 439 | return 0; |
| 440 | |
| 441 | /* |
| 442 | * Clockevents returns -ETIME, when the event was in the past. |
| 443 | */ |
| 444 | res = tick_program_event(expires, 0); |
| 445 | if (!IS_ERR_VALUE(res)) |
| 446 | *expires_next = expires; |
| 447 | return res; |
| 448 | } |
| 449 | |
| 450 | |
| 451 | /* |
| 452 | * Retrigger next event is called after clock was set |
| 453 | * |
| 454 | * Called with interrupts disabled via on_each_cpu() |
| 455 | */ |
| 456 | static void retrigger_next_event(void *arg) |
| 457 | { |
| 458 | struct hrtimer_cpu_base *base; |
| 459 | struct timespec realtime_offset; |
| 460 | unsigned long seq; |
| 461 | |
| 462 | if (!hrtimer_hres_active()) |
| 463 | return; |
| 464 | |
| 465 | do { |
| 466 | seq = read_seqbegin(&xtime_lock); |
| 467 | set_normalized_timespec(&realtime_offset, |
| 468 | -wall_to_monotonic.tv_sec, |
| 469 | -wall_to_monotonic.tv_nsec); |
| 470 | } while (read_seqretry(&xtime_lock, seq)); |
| 471 | |
| 472 | base = &__get_cpu_var(hrtimer_bases); |
| 473 | |
| 474 | /* Adjust CLOCK_REALTIME offset */ |
| 475 | spin_lock(&base->lock); |
| 476 | base->clock_base[CLOCK_REALTIME].offset = |
| 477 | timespec_to_ktime(realtime_offset); |
| 478 | |
| 479 | hrtimer_force_reprogram(base); |
| 480 | spin_unlock(&base->lock); |
| 481 | } |
| 482 | |
| 483 | /* |
| 484 | * Clock realtime was set |
| 485 | * |
| 486 | * Change the offset of the realtime clock vs. the monotonic |
| 487 | * clock. |
| 488 | * |
| 489 | * We might have to reprogram the high resolution timer interrupt. On |
| 490 | * SMP we call the architecture specific code to retrigger _all_ high |
| 491 | * resolution timer interrupts. On UP we just disable interrupts and |
| 492 | * call the high resolution interrupt code. |
| 493 | */ |
| 494 | void clock_was_set(void) |
| 495 | { |
| 496 | /* Retrigger the CPU local events everywhere */ |
| 497 | on_each_cpu(retrigger_next_event, NULL, 0, 1); |
| 498 | } |
| 499 | |
| 500 | /* |
Ingo Molnar | 995f054 | 2007-04-07 12:05:00 +0200 | [diff] [blame] | 501 | * During resume we might have to reprogram the high resolution timer |
| 502 | * interrupt (on the local CPU): |
| 503 | */ |
| 504 | void hres_timers_resume(void) |
| 505 | { |
| 506 | WARN_ON_ONCE(num_online_cpus() > 1); |
| 507 | |
| 508 | /* Retrigger the CPU local events: */ |
| 509 | retrigger_next_event(NULL); |
| 510 | } |
| 511 | |
| 512 | /* |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 513 | * Initialize the high resolution related parts of cpu_base |
| 514 | */ |
| 515 | static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) |
| 516 | { |
| 517 | base->expires_next.tv64 = KTIME_MAX; |
| 518 | base->hres_active = 0; |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 519 | } |
| 520 | |
| 521 | /* |
| 522 | * Initialize the high resolution related parts of a hrtimer |
| 523 | */ |
| 524 | static inline void hrtimer_init_timer_hres(struct hrtimer *timer) |
| 525 | { |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 526 | } |
| 527 | |
| 528 | /* |
| 529 | * When High resolution timers are active, try to reprogram. Note, that in case |
| 530 | * the state has HRTIMER_STATE_CALLBACK set, no reprogramming and no expiry |
| 531 | * check happens. The timer gets enqueued into the rbtree. The reprogramming |
| 532 | * and expiry check is done in the hrtimer_interrupt or in the softirq. |
| 533 | */ |
| 534 | static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer, |
| 535 | struct hrtimer_clock_base *base) |
| 536 | { |
| 537 | if (base->cpu_base->hres_active && hrtimer_reprogram(timer, base)) { |
| 538 | |
| 539 | /* Timer is expired, act upon the callback mode */ |
| 540 | switch(timer->cb_mode) { |
| 541 | case HRTIMER_CB_IRQSAFE_NO_RESTART: |
| 542 | /* |
| 543 | * We can call the callback from here. No restart |
| 544 | * happens, so no danger of recursion |
| 545 | */ |
| 546 | BUG_ON(timer->function(timer) != HRTIMER_NORESTART); |
| 547 | return 1; |
| 548 | case HRTIMER_CB_IRQSAFE_NO_SOFTIRQ: |
| 549 | /* |
| 550 | * This is solely for the sched tick emulation with |
| 551 | * dynamic tick support to ensure that we do not |
| 552 | * restart the tick right on the edge and end up with |
| 553 | * the tick timer in the softirq ! The calling site |
| 554 | * takes care of this. |
| 555 | */ |
| 556 | return 1; |
| 557 | case HRTIMER_CB_IRQSAFE: |
| 558 | case HRTIMER_CB_SOFTIRQ: |
| 559 | /* |
| 560 | * Move everything else into the softirq pending list ! |
| 561 | */ |
| 562 | list_add_tail(&timer->cb_entry, |
| 563 | &base->cpu_base->cb_pending); |
| 564 | timer->state = HRTIMER_STATE_PENDING; |
| 565 | raise_softirq(HRTIMER_SOFTIRQ); |
| 566 | return 1; |
| 567 | default: |
| 568 | BUG(); |
| 569 | } |
| 570 | } |
| 571 | return 0; |
| 572 | } |
| 573 | |
| 574 | /* |
| 575 | * Switch to high resolution mode |
| 576 | */ |
Thomas Gleixner | f895385 | 2007-03-06 01:42:08 -0800 | [diff] [blame] | 577 | static int hrtimer_switch_to_hres(void) |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 578 | { |
Ingo Molnar | 820de5c | 2007-07-21 04:37:36 -0700 | [diff] [blame] | 579 | int cpu = smp_processor_id(); |
| 580 | struct hrtimer_cpu_base *base = &per_cpu(hrtimer_bases, cpu); |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 581 | unsigned long flags; |
| 582 | |
| 583 | if (base->hres_active) |
Thomas Gleixner | f895385 | 2007-03-06 01:42:08 -0800 | [diff] [blame] | 584 | return 1; |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 585 | |
| 586 | local_irq_save(flags); |
| 587 | |
| 588 | if (tick_init_highres()) { |
| 589 | local_irq_restore(flags); |
Ingo Molnar | 820de5c | 2007-07-21 04:37:36 -0700 | [diff] [blame] | 590 | printk(KERN_WARNING "Could not switch to high resolution " |
| 591 | "mode on CPU %d\n", cpu); |
Thomas Gleixner | f895385 | 2007-03-06 01:42:08 -0800 | [diff] [blame] | 592 | return 0; |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 593 | } |
| 594 | base->hres_active = 1; |
| 595 | base->clock_base[CLOCK_REALTIME].resolution = KTIME_HIGH_RES; |
| 596 | base->clock_base[CLOCK_MONOTONIC].resolution = KTIME_HIGH_RES; |
| 597 | |
| 598 | tick_setup_sched_timer(); |
| 599 | |
| 600 | /* "Retrigger" the interrupt to get things going */ |
| 601 | retrigger_next_event(NULL); |
| 602 | local_irq_restore(flags); |
Michael Ellerman | edfed66 | 2007-10-29 16:35:29 +1100 | [diff] [blame] | 603 | printk(KERN_DEBUG "Switched to high resolution mode on CPU %d\n", |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 604 | smp_processor_id()); |
Thomas Gleixner | f895385 | 2007-03-06 01:42:08 -0800 | [diff] [blame] | 605 | return 1; |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 606 | } |
| 607 | |
| 608 | #else |
| 609 | |
| 610 | static inline int hrtimer_hres_active(void) { return 0; } |
| 611 | static inline int hrtimer_is_hres_enabled(void) { return 0; } |
Thomas Gleixner | f895385 | 2007-03-06 01:42:08 -0800 | [diff] [blame] | 612 | static inline int hrtimer_switch_to_hres(void) { return 0; } |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 613 | static inline void hrtimer_force_reprogram(struct hrtimer_cpu_base *base) { } |
| 614 | static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer, |
| 615 | struct hrtimer_clock_base *base) |
| 616 | { |
| 617 | return 0; |
| 618 | } |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 619 | static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) { } |
| 620 | static inline void hrtimer_init_timer_hres(struct hrtimer *timer) { } |
Peter Zijlstra | d3d7445 | 2008-01-25 21:08:31 +0100 | [diff] [blame] | 621 | static inline int hrtimer_reprogram(struct hrtimer *timer, |
| 622 | struct hrtimer_clock_base *base) |
| 623 | { |
| 624 | return 0; |
| 625 | } |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 626 | |
| 627 | #endif /* CONFIG_HIGH_RES_TIMERS */ |
| 628 | |
Ingo Molnar | 82f67cd | 2007-02-16 01:28:13 -0800 | [diff] [blame] | 629 | #ifdef CONFIG_TIMER_STATS |
| 630 | void __timer_stats_hrtimer_set_start_info(struct hrtimer *timer, void *addr) |
| 631 | { |
| 632 | if (timer->start_site) |
| 633 | return; |
| 634 | |
| 635 | timer->start_site = addr; |
| 636 | memcpy(timer->start_comm, current->comm, TASK_COMM_LEN); |
| 637 | timer->start_pid = current->pid; |
| 638 | } |
| 639 | #endif |
| 640 | |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 641 | /* |
Uwe Kleine-König | 6506f2a | 2007-10-20 01:56:53 +0200 | [diff] [blame] | 642 | * Counterpart to lock_hrtimer_base above: |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 643 | */ |
| 644 | static inline |
| 645 | void unlock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags) |
| 646 | { |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 647 | spin_unlock_irqrestore(&timer->base->cpu_base->lock, *flags); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 648 | } |
| 649 | |
| 650 | /** |
| 651 | * hrtimer_forward - forward the timer expiry |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 652 | * @timer: hrtimer to forward |
Roman Zippel | 44f2147 | 2006-03-26 01:38:06 -0800 | [diff] [blame] | 653 | * @now: forward past this time |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 654 | * @interval: the interval to forward |
| 655 | * |
| 656 | * Forward the timer expiry so it will expire in the future. |
Jonathan Corbet | 8dca6f3 | 2006-01-16 15:58:55 -0700 | [diff] [blame] | 657 | * Returns the number of overruns. |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 658 | */ |
Davide Libenzi | 4d672e7a | 2008-02-04 22:27:26 -0800 | [diff] [blame] | 659 | u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval) |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 660 | { |
Davide Libenzi | 4d672e7a | 2008-02-04 22:27:26 -0800 | [diff] [blame] | 661 | u64 orun = 1; |
Roman Zippel | 44f2147 | 2006-03-26 01:38:06 -0800 | [diff] [blame] | 662 | ktime_t delta; |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 663 | |
| 664 | delta = ktime_sub(now, timer->expires); |
| 665 | |
| 666 | if (delta.tv64 < 0) |
| 667 | return 0; |
| 668 | |
Thomas Gleixner | c9db4fa | 2006-01-12 11:47:34 +0100 | [diff] [blame] | 669 | if (interval.tv64 < timer->base->resolution.tv64) |
| 670 | interval.tv64 = timer->base->resolution.tv64; |
| 671 | |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 672 | if (unlikely(delta.tv64 >= interval.tv64)) { |
Roman Zippel | df869b6 | 2006-03-26 01:38:11 -0800 | [diff] [blame] | 673 | s64 incr = ktime_to_ns(interval); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 674 | |
| 675 | orun = ktime_divns(delta, incr); |
| 676 | timer->expires = ktime_add_ns(timer->expires, incr * orun); |
| 677 | if (timer->expires.tv64 > now.tv64) |
| 678 | return orun; |
| 679 | /* |
| 680 | * This (and the ktime_add() below) is the |
| 681 | * correction for exact: |
| 682 | */ |
| 683 | orun++; |
| 684 | } |
| 685 | timer->expires = ktime_add(timer->expires, interval); |
Thomas Gleixner | 13788cc | 2007-03-16 13:38:20 -0800 | [diff] [blame] | 686 | /* |
| 687 | * Make sure, that the result did not wrap with a very large |
| 688 | * interval. |
| 689 | */ |
| 690 | if (timer->expires.tv64 < 0) |
| 691 | timer->expires = ktime_set(KTIME_SEC_MAX, 0); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 692 | |
| 693 | return orun; |
| 694 | } |
Stas Sergeev | 6bdb6b6 | 2007-05-08 00:31:58 -0700 | [diff] [blame] | 695 | EXPORT_SYMBOL_GPL(hrtimer_forward); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 696 | |
| 697 | /* |
| 698 | * enqueue_hrtimer - internal function to (re)start a timer |
| 699 | * |
| 700 | * The timer is inserted in expiry order. Insertion into the |
| 701 | * red black tree is O(log(n)). Must hold the base lock. |
| 702 | */ |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 703 | static void enqueue_hrtimer(struct hrtimer *timer, |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 704 | struct hrtimer_clock_base *base, int reprogram) |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 705 | { |
| 706 | struct rb_node **link = &base->active.rb_node; |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 707 | struct rb_node *parent = NULL; |
| 708 | struct hrtimer *entry; |
Ingo Molnar | 99bc2fc | 2007-07-21 04:37:36 -0700 | [diff] [blame] | 709 | int leftmost = 1; |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 710 | |
| 711 | /* |
| 712 | * Find the right place in the rbtree: |
| 713 | */ |
| 714 | while (*link) { |
| 715 | parent = *link; |
| 716 | entry = rb_entry(parent, struct hrtimer, node); |
| 717 | /* |
| 718 | * We dont care about collisions. Nodes with |
| 719 | * the same expiry time stay together. |
| 720 | */ |
Ingo Molnar | 99bc2fc | 2007-07-21 04:37:36 -0700 | [diff] [blame] | 721 | if (timer->expires.tv64 < entry->expires.tv64) { |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 722 | link = &(*link)->rb_left; |
Ingo Molnar | 99bc2fc | 2007-07-21 04:37:36 -0700 | [diff] [blame] | 723 | } else { |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 724 | link = &(*link)->rb_right; |
Ingo Molnar | 99bc2fc | 2007-07-21 04:37:36 -0700 | [diff] [blame] | 725 | leftmost = 0; |
| 726 | } |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 727 | } |
| 728 | |
| 729 | /* |
Thomas Gleixner | 288867e | 2006-01-12 11:25:54 +0100 | [diff] [blame] | 730 | * Insert the timer to the rbtree and check whether it |
| 731 | * replaces the first pending timer |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 732 | */ |
Ingo Molnar | 99bc2fc | 2007-07-21 04:37:36 -0700 | [diff] [blame] | 733 | if (leftmost) { |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 734 | /* |
| 735 | * Reprogram the clock event device. When the timer is already |
| 736 | * expired hrtimer_enqueue_reprogram has either called the |
| 737 | * callback or added it to the pending list and raised the |
| 738 | * softirq. |
| 739 | * |
| 740 | * This is a NOP for !HIGHRES |
| 741 | */ |
| 742 | if (reprogram && hrtimer_enqueue_reprogram(timer, base)) |
| 743 | return; |
| 744 | |
| 745 | base->first = &timer->node; |
| 746 | } |
| 747 | |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 748 | rb_link_node(&timer->node, parent, link); |
| 749 | rb_insert_color(&timer->node, &base->active); |
Thomas Gleixner | 303e967 | 2007-02-16 01:27:51 -0800 | [diff] [blame] | 750 | /* |
| 751 | * HRTIMER_STATE_ENQUEUED is or'ed to the current state to preserve the |
| 752 | * state of a possibly running callback. |
| 753 | */ |
| 754 | timer->state |= HRTIMER_STATE_ENQUEUED; |
Thomas Gleixner | 288867e | 2006-01-12 11:25:54 +0100 | [diff] [blame] | 755 | } |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 756 | |
| 757 | /* |
| 758 | * __remove_hrtimer - internal function to remove a timer |
| 759 | * |
| 760 | * Caller must hold the base lock. |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 761 | * |
| 762 | * High resolution timer mode reprograms the clock event device when the |
| 763 | * timer is the one which expires next. The caller can disable this by setting |
| 764 | * reprogram to zero. This is useful, when the context does a reprogramming |
| 765 | * anyway (e.g. timer interrupt) |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 766 | */ |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 767 | static void __remove_hrtimer(struct hrtimer *timer, |
Thomas Gleixner | 303e967 | 2007-02-16 01:27:51 -0800 | [diff] [blame] | 768 | struct hrtimer_clock_base *base, |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 769 | unsigned long newstate, int reprogram) |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 770 | { |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 771 | /* High res. callback list. NOP for !HIGHRES */ |
| 772 | if (hrtimer_cb_pending(timer)) |
| 773 | hrtimer_remove_cb_pending(timer); |
| 774 | else { |
| 775 | /* |
| 776 | * Remove the timer from the rbtree and replace the |
| 777 | * first entry pointer if necessary. |
| 778 | */ |
| 779 | if (base->first == &timer->node) { |
| 780 | base->first = rb_next(&timer->node); |
| 781 | /* Reprogram the clock event device. if enabled */ |
| 782 | if (reprogram && hrtimer_hres_active()) |
| 783 | hrtimer_force_reprogram(base->cpu_base); |
| 784 | } |
| 785 | rb_erase(&timer->node, &base->active); |
| 786 | } |
Thomas Gleixner | 303e967 | 2007-02-16 01:27:51 -0800 | [diff] [blame] | 787 | timer->state = newstate; |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 788 | } |
| 789 | |
| 790 | /* |
| 791 | * remove hrtimer, called with base lock held |
| 792 | */ |
| 793 | static inline int |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 794 | remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base) |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 795 | { |
Thomas Gleixner | 303e967 | 2007-02-16 01:27:51 -0800 | [diff] [blame] | 796 | if (hrtimer_is_queued(timer)) { |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 797 | int reprogram; |
| 798 | |
| 799 | /* |
| 800 | * Remove the timer and force reprogramming when high |
| 801 | * resolution mode is active and the timer is on the current |
| 802 | * CPU. If we remove a timer on another CPU, reprogramming is |
| 803 | * skipped. The interrupt event on this CPU is fired and |
| 804 | * reprogramming happens in the interrupt handler. This is a |
| 805 | * rare case and less expensive than a smp call. |
| 806 | */ |
Ingo Molnar | 82f67cd | 2007-02-16 01:28:13 -0800 | [diff] [blame] | 807 | timer_stats_hrtimer_clear_start_info(timer); |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 808 | reprogram = base->cpu_base == &__get_cpu_var(hrtimer_bases); |
| 809 | __remove_hrtimer(timer, base, HRTIMER_STATE_INACTIVE, |
| 810 | reprogram); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 811 | return 1; |
| 812 | } |
| 813 | return 0; |
| 814 | } |
| 815 | |
| 816 | /** |
| 817 | * hrtimer_start - (re)start an relative timer on the current CPU |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 818 | * @timer: the timer to be added |
| 819 | * @tim: expiry time |
| 820 | * @mode: expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL) |
| 821 | * |
| 822 | * Returns: |
| 823 | * 0 on success |
| 824 | * 1 when the timer was active |
| 825 | */ |
| 826 | int |
| 827 | hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode) |
| 828 | { |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 829 | struct hrtimer_clock_base *base, *new_base; |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 830 | unsigned long flags; |
| 831 | int ret; |
| 832 | |
| 833 | base = lock_hrtimer_base(timer, &flags); |
| 834 | |
| 835 | /* Remove an active timer from the queue: */ |
| 836 | ret = remove_hrtimer(timer, base); |
| 837 | |
| 838 | /* Switch the timer base, if necessary: */ |
| 839 | new_base = switch_hrtimer_base(timer, base); |
| 840 | |
Thomas Gleixner | c9cb2e3 | 2007-02-16 01:27:49 -0800 | [diff] [blame] | 841 | if (mode == HRTIMER_MODE_REL) { |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 842 | tim = ktime_add(tim, new_base->get_time()); |
Ingo Molnar | 06027bd | 2006-02-14 13:53:15 -0800 | [diff] [blame] | 843 | /* |
| 844 | * CONFIG_TIME_LOW_RES is a temporary way for architectures |
| 845 | * to signal that they simply return xtime in |
| 846 | * do_gettimeoffset(). In this case we want to round up by |
| 847 | * resolution when starting a relative timer, to avoid short |
| 848 | * timeouts. This will go away with the GTOD framework. |
| 849 | */ |
| 850 | #ifdef CONFIG_TIME_LOW_RES |
| 851 | tim = ktime_add(tim, base->resolution); |
| 852 | #endif |
Thomas Gleixner | 62f0f61 | 2007-12-07 19:16:17 +0100 | [diff] [blame] | 853 | /* |
| 854 | * Careful here: User space might have asked for a |
| 855 | * very long sleep, so the add above might result in a |
| 856 | * negative number, which enqueues the timer in front |
| 857 | * of the queue. |
| 858 | */ |
| 859 | if (tim.tv64 < 0) |
| 860 | tim.tv64 = KTIME_MAX; |
Ingo Molnar | 06027bd | 2006-02-14 13:53:15 -0800 | [diff] [blame] | 861 | } |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 862 | timer->expires = tim; |
| 863 | |
Ingo Molnar | 82f67cd | 2007-02-16 01:28:13 -0800 | [diff] [blame] | 864 | timer_stats_hrtimer_set_start_info(timer); |
| 865 | |
Ingo Molnar | 935c631 | 2007-03-28 13:17:18 +0200 | [diff] [blame] | 866 | /* |
| 867 | * Only allow reprogramming if the new base is on this CPU. |
| 868 | * (it might still be on another CPU if the timer was pending) |
| 869 | */ |
| 870 | enqueue_hrtimer(timer, new_base, |
| 871 | new_base->cpu_base == &__get_cpu_var(hrtimer_bases)); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 872 | |
| 873 | unlock_hrtimer_base(timer, &flags); |
| 874 | |
| 875 | return ret; |
| 876 | } |
Stephen Hemminger | 8d16b76 | 2006-05-30 21:26:09 -0700 | [diff] [blame] | 877 | EXPORT_SYMBOL_GPL(hrtimer_start); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 878 | |
| 879 | /** |
| 880 | * hrtimer_try_to_cancel - try to deactivate a timer |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 881 | * @timer: hrtimer to stop |
| 882 | * |
| 883 | * Returns: |
| 884 | * 0 when the timer was not active |
| 885 | * 1 when the timer was active |
| 886 | * -1 when the timer is currently excuting the callback function and |
Randy Dunlap | fa9799e | 2006-06-25 05:49:15 -0700 | [diff] [blame] | 887 | * cannot be stopped |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 888 | */ |
| 889 | int hrtimer_try_to_cancel(struct hrtimer *timer) |
| 890 | { |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 891 | struct hrtimer_clock_base *base; |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 892 | unsigned long flags; |
| 893 | int ret = -1; |
| 894 | |
| 895 | base = lock_hrtimer_base(timer, &flags); |
| 896 | |
Thomas Gleixner | 303e967 | 2007-02-16 01:27:51 -0800 | [diff] [blame] | 897 | if (!hrtimer_callback_running(timer)) |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 898 | ret = remove_hrtimer(timer, base); |
| 899 | |
| 900 | unlock_hrtimer_base(timer, &flags); |
| 901 | |
| 902 | return ret; |
| 903 | |
| 904 | } |
Stephen Hemminger | 8d16b76 | 2006-05-30 21:26:09 -0700 | [diff] [blame] | 905 | EXPORT_SYMBOL_GPL(hrtimer_try_to_cancel); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 906 | |
| 907 | /** |
| 908 | * hrtimer_cancel - cancel a timer and wait for the handler to finish. |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 909 | * @timer: the timer to be cancelled |
| 910 | * |
| 911 | * Returns: |
| 912 | * 0 when the timer was not active |
| 913 | * 1 when the timer was active |
| 914 | */ |
| 915 | int hrtimer_cancel(struct hrtimer *timer) |
| 916 | { |
| 917 | for (;;) { |
| 918 | int ret = hrtimer_try_to_cancel(timer); |
| 919 | |
| 920 | if (ret >= 0) |
| 921 | return ret; |
Joe Korty | 5ef37b1 | 2006-04-10 22:54:13 -0700 | [diff] [blame] | 922 | cpu_relax(); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 923 | } |
| 924 | } |
Stephen Hemminger | 8d16b76 | 2006-05-30 21:26:09 -0700 | [diff] [blame] | 925 | EXPORT_SYMBOL_GPL(hrtimer_cancel); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 926 | |
| 927 | /** |
| 928 | * hrtimer_get_remaining - get remaining time for the timer |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 929 | * @timer: the timer to read |
| 930 | */ |
| 931 | ktime_t hrtimer_get_remaining(const struct hrtimer *timer) |
| 932 | { |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 933 | struct hrtimer_clock_base *base; |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 934 | unsigned long flags; |
| 935 | ktime_t rem; |
| 936 | |
| 937 | base = lock_hrtimer_base(timer, &flags); |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 938 | rem = ktime_sub(timer->expires, base->get_time()); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 939 | unlock_hrtimer_base(timer, &flags); |
| 940 | |
| 941 | return rem; |
| 942 | } |
Stephen Hemminger | 8d16b76 | 2006-05-30 21:26:09 -0700 | [diff] [blame] | 943 | EXPORT_SYMBOL_GPL(hrtimer_get_remaining); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 944 | |
Thomas Gleixner | fd064b9 | 2007-02-16 01:27:47 -0800 | [diff] [blame] | 945 | #if defined(CONFIG_NO_IDLE_HZ) || defined(CONFIG_NO_HZ) |
Tony Lindgren | 6923974 | 2006-03-06 15:42:45 -0800 | [diff] [blame] | 946 | /** |
| 947 | * hrtimer_get_next_event - get the time until next expiry event |
| 948 | * |
| 949 | * Returns the delta to the next expiry event or KTIME_MAX if no timer |
| 950 | * is pending. |
| 951 | */ |
| 952 | ktime_t hrtimer_get_next_event(void) |
| 953 | { |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 954 | struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); |
| 955 | struct hrtimer_clock_base *base = cpu_base->clock_base; |
Tony Lindgren | 6923974 | 2006-03-06 15:42:45 -0800 | [diff] [blame] | 956 | ktime_t delta, mindelta = { .tv64 = KTIME_MAX }; |
| 957 | unsigned long flags; |
| 958 | int i; |
| 959 | |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 960 | spin_lock_irqsave(&cpu_base->lock, flags); |
| 961 | |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 962 | if (!hrtimer_hres_active()) { |
| 963 | for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) { |
| 964 | struct hrtimer *timer; |
Tony Lindgren | 6923974 | 2006-03-06 15:42:45 -0800 | [diff] [blame] | 965 | |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 966 | if (!base->first) |
| 967 | continue; |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 968 | |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 969 | timer = rb_entry(base->first, struct hrtimer, node); |
| 970 | delta.tv64 = timer->expires.tv64; |
| 971 | delta = ktime_sub(delta, base->get_time()); |
| 972 | if (delta.tv64 < mindelta.tv64) |
| 973 | mindelta.tv64 = delta.tv64; |
| 974 | } |
Tony Lindgren | 6923974 | 2006-03-06 15:42:45 -0800 | [diff] [blame] | 975 | } |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 976 | |
| 977 | spin_unlock_irqrestore(&cpu_base->lock, flags); |
| 978 | |
Tony Lindgren | 6923974 | 2006-03-06 15:42:45 -0800 | [diff] [blame] | 979 | if (mindelta.tv64 < 0) |
| 980 | mindelta.tv64 = 0; |
| 981 | return mindelta; |
| 982 | } |
| 983 | #endif |
| 984 | |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 985 | /** |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 986 | * hrtimer_init - initialize a timer to the given clock |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 987 | * @timer: the timer to be initialized |
| 988 | * @clock_id: the clock to be used |
George Anzinger | 7978672c | 2006-02-01 03:05:11 -0800 | [diff] [blame] | 989 | * @mode: timer mode abs/rel |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 990 | */ |
George Anzinger | 7978672c | 2006-02-01 03:05:11 -0800 | [diff] [blame] | 991 | void hrtimer_init(struct hrtimer *timer, clockid_t clock_id, |
| 992 | enum hrtimer_mode mode) |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 993 | { |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 994 | struct hrtimer_cpu_base *cpu_base; |
George Anzinger | 7978672c | 2006-02-01 03:05:11 -0800 | [diff] [blame] | 995 | |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 996 | memset(timer, 0, sizeof(struct hrtimer)); |
George Anzinger | 7978672c | 2006-02-01 03:05:11 -0800 | [diff] [blame] | 997 | |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 998 | cpu_base = &__raw_get_cpu_var(hrtimer_bases); |
George Anzinger | 7978672c | 2006-02-01 03:05:11 -0800 | [diff] [blame] | 999 | |
Thomas Gleixner | c9cb2e3 | 2007-02-16 01:27:49 -0800 | [diff] [blame] | 1000 | if (clock_id == CLOCK_REALTIME && mode != HRTIMER_MODE_ABS) |
George Anzinger | 7978672c | 2006-02-01 03:05:11 -0800 | [diff] [blame] | 1001 | clock_id = CLOCK_MONOTONIC; |
| 1002 | |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 1003 | timer->base = &cpu_base->clock_base[clock_id]; |
Peter Zijlstra | d3d7445 | 2008-01-25 21:08:31 +0100 | [diff] [blame] | 1004 | INIT_LIST_HEAD(&timer->cb_entry); |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 1005 | hrtimer_init_timer_hres(timer); |
Ingo Molnar | 82f67cd | 2007-02-16 01:28:13 -0800 | [diff] [blame] | 1006 | |
| 1007 | #ifdef CONFIG_TIMER_STATS |
| 1008 | timer->start_site = NULL; |
| 1009 | timer->start_pid = -1; |
| 1010 | memset(timer->start_comm, 0, TASK_COMM_LEN); |
| 1011 | #endif |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1012 | } |
Stephen Hemminger | 8d16b76 | 2006-05-30 21:26:09 -0700 | [diff] [blame] | 1013 | EXPORT_SYMBOL_GPL(hrtimer_init); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1014 | |
| 1015 | /** |
| 1016 | * hrtimer_get_res - get the timer resolution for a clock |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1017 | * @which_clock: which clock to query |
| 1018 | * @tp: pointer to timespec variable to store the resolution |
| 1019 | * |
Robert P. J. Day | 72fd4a3 | 2007-02-10 01:45:59 -0800 | [diff] [blame] | 1020 | * Store the resolution of the clock selected by @which_clock in the |
| 1021 | * variable pointed to by @tp. |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1022 | */ |
| 1023 | int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp) |
| 1024 | { |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 1025 | struct hrtimer_cpu_base *cpu_base; |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1026 | |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 1027 | cpu_base = &__raw_get_cpu_var(hrtimer_bases); |
| 1028 | *tp = ktime_to_timespec(cpu_base->clock_base[which_clock].resolution); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1029 | |
| 1030 | return 0; |
| 1031 | } |
Stephen Hemminger | 8d16b76 | 2006-05-30 21:26:09 -0700 | [diff] [blame] | 1032 | EXPORT_SYMBOL_GPL(hrtimer_get_res); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1033 | |
Peter Zijlstra | d3d7445 | 2008-01-25 21:08:31 +0100 | [diff] [blame] | 1034 | static void run_hrtimer_pending(struct hrtimer_cpu_base *cpu_base) |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 1035 | { |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 1036 | spin_lock_irq(&cpu_base->lock); |
| 1037 | |
| 1038 | while (!list_empty(&cpu_base->cb_pending)) { |
| 1039 | enum hrtimer_restart (*fn)(struct hrtimer *); |
| 1040 | struct hrtimer *timer; |
| 1041 | int restart; |
| 1042 | |
| 1043 | timer = list_entry(cpu_base->cb_pending.next, |
| 1044 | struct hrtimer, cb_entry); |
| 1045 | |
Ingo Molnar | 82f67cd | 2007-02-16 01:28:13 -0800 | [diff] [blame] | 1046 | timer_stats_account_hrtimer(timer); |
| 1047 | |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 1048 | fn = timer->function; |
| 1049 | __remove_hrtimer(timer, timer->base, HRTIMER_STATE_CALLBACK, 0); |
| 1050 | spin_unlock_irq(&cpu_base->lock); |
| 1051 | |
| 1052 | restart = fn(timer); |
| 1053 | |
| 1054 | spin_lock_irq(&cpu_base->lock); |
| 1055 | |
| 1056 | timer->state &= ~HRTIMER_STATE_CALLBACK; |
| 1057 | if (restart == HRTIMER_RESTART) { |
| 1058 | BUG_ON(hrtimer_active(timer)); |
| 1059 | /* |
| 1060 | * Enqueue the timer, allow reprogramming of the event |
| 1061 | * device |
| 1062 | */ |
| 1063 | enqueue_hrtimer(timer, timer->base, 1); |
| 1064 | } else if (hrtimer_active(timer)) { |
| 1065 | /* |
| 1066 | * If the timer was rearmed on another CPU, reprogram |
| 1067 | * the event device. |
| 1068 | */ |
| 1069 | if (timer->base->first == &timer->node) |
| 1070 | hrtimer_reprogram(timer, timer->base); |
| 1071 | } |
| 1072 | } |
| 1073 | spin_unlock_irq(&cpu_base->lock); |
| 1074 | } |
| 1075 | |
Peter Zijlstra | d3d7445 | 2008-01-25 21:08:31 +0100 | [diff] [blame] | 1076 | static void __run_hrtimer(struct hrtimer *timer) |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1077 | { |
Peter Zijlstra | d3d7445 | 2008-01-25 21:08:31 +0100 | [diff] [blame] | 1078 | struct hrtimer_clock_base *base = timer->base; |
| 1079 | struct hrtimer_cpu_base *cpu_base = base->cpu_base; |
| 1080 | enum hrtimer_restart (*fn)(struct hrtimer *); |
| 1081 | int restart; |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1082 | |
Peter Zijlstra | d3d7445 | 2008-01-25 21:08:31 +0100 | [diff] [blame] | 1083 | __remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0); |
| 1084 | timer_stats_account_hrtimer(timer); |
Dimitri Sivanich | 3055add | 2006-03-31 02:31:20 -0800 | [diff] [blame] | 1085 | |
Peter Zijlstra | d3d7445 | 2008-01-25 21:08:31 +0100 | [diff] [blame] | 1086 | fn = timer->function; |
| 1087 | if (timer->cb_mode == HRTIMER_CB_IRQSAFE_NO_SOFTIRQ) { |
| 1088 | /* |
| 1089 | * Used for scheduler timers, avoid lock inversion with |
| 1090 | * rq->lock and tasklist_lock. |
| 1091 | * |
| 1092 | * These timers are required to deal with enqueue expiry |
| 1093 | * themselves and are not allowed to migrate. |
| 1094 | */ |
| 1095 | spin_unlock(&cpu_base->lock); |
| 1096 | restart = fn(timer); |
| 1097 | spin_lock(&cpu_base->lock); |
| 1098 | } else |
Roman Zippel | 05cfb61 | 2006-03-26 01:38:12 -0800 | [diff] [blame] | 1099 | restart = fn(timer); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1100 | |
Peter Zijlstra | d3d7445 | 2008-01-25 21:08:31 +0100 | [diff] [blame] | 1101 | /* |
| 1102 | * Note: We clear the CALLBACK bit after enqueue_hrtimer to avoid |
| 1103 | * reprogramming of the event hardware. This happens at the end of this |
| 1104 | * function anyway. |
| 1105 | */ |
| 1106 | if (restart != HRTIMER_NORESTART) { |
| 1107 | BUG_ON(timer->state != HRTIMER_STATE_CALLBACK); |
| 1108 | enqueue_hrtimer(timer, base, 0); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1109 | } |
Peter Zijlstra | d3d7445 | 2008-01-25 21:08:31 +0100 | [diff] [blame] | 1110 | timer->state &= ~HRTIMER_STATE_CALLBACK; |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1111 | } |
| 1112 | |
Peter Zijlstra | d3d7445 | 2008-01-25 21:08:31 +0100 | [diff] [blame] | 1113 | #ifdef CONFIG_HIGH_RES_TIMERS |
| 1114 | |
| 1115 | /* |
| 1116 | * High resolution timer interrupt |
| 1117 | * Called with interrupts disabled |
| 1118 | */ |
| 1119 | void hrtimer_interrupt(struct clock_event_device *dev) |
| 1120 | { |
| 1121 | struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); |
| 1122 | struct hrtimer_clock_base *base; |
| 1123 | ktime_t expires_next, now; |
| 1124 | int i, raise = 0; |
| 1125 | |
| 1126 | BUG_ON(!cpu_base->hres_active); |
| 1127 | cpu_base->nr_events++; |
| 1128 | dev->next_event.tv64 = KTIME_MAX; |
| 1129 | |
| 1130 | retry: |
| 1131 | now = ktime_get(); |
| 1132 | |
| 1133 | expires_next.tv64 = KTIME_MAX; |
| 1134 | |
| 1135 | base = cpu_base->clock_base; |
| 1136 | |
| 1137 | for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { |
| 1138 | ktime_t basenow; |
| 1139 | struct rb_node *node; |
| 1140 | |
| 1141 | spin_lock(&cpu_base->lock); |
| 1142 | |
| 1143 | basenow = ktime_add(now, base->offset); |
| 1144 | |
| 1145 | while ((node = base->first)) { |
| 1146 | struct hrtimer *timer; |
| 1147 | |
| 1148 | timer = rb_entry(node, struct hrtimer, node); |
| 1149 | |
| 1150 | if (basenow.tv64 < timer->expires.tv64) { |
| 1151 | ktime_t expires; |
| 1152 | |
| 1153 | expires = ktime_sub(timer->expires, |
| 1154 | base->offset); |
| 1155 | if (expires.tv64 < expires_next.tv64) |
| 1156 | expires_next = expires; |
| 1157 | break; |
| 1158 | } |
| 1159 | |
| 1160 | /* Move softirq callbacks to the pending list */ |
| 1161 | if (timer->cb_mode == HRTIMER_CB_SOFTIRQ) { |
| 1162 | __remove_hrtimer(timer, base, |
| 1163 | HRTIMER_STATE_PENDING, 0); |
| 1164 | list_add_tail(&timer->cb_entry, |
| 1165 | &base->cpu_base->cb_pending); |
| 1166 | raise = 1; |
| 1167 | continue; |
| 1168 | } |
| 1169 | |
| 1170 | __run_hrtimer(timer); |
| 1171 | } |
| 1172 | spin_unlock(&cpu_base->lock); |
| 1173 | base++; |
| 1174 | } |
| 1175 | |
| 1176 | cpu_base->expires_next = expires_next; |
| 1177 | |
| 1178 | /* Reprogramming necessary ? */ |
| 1179 | if (expires_next.tv64 != KTIME_MAX) { |
| 1180 | if (tick_program_event(expires_next, 0)) |
| 1181 | goto retry; |
| 1182 | } |
| 1183 | |
| 1184 | /* Raise softirq ? */ |
| 1185 | if (raise) |
| 1186 | raise_softirq(HRTIMER_SOFTIRQ); |
| 1187 | } |
| 1188 | |
| 1189 | static void run_hrtimer_softirq(struct softirq_action *h) |
| 1190 | { |
| 1191 | run_hrtimer_pending(&__get_cpu_var(hrtimer_bases)); |
| 1192 | } |
| 1193 | |
| 1194 | #endif /* CONFIG_HIGH_RES_TIMERS */ |
| 1195 | |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1196 | /* |
| 1197 | * Called from timer softirq every jiffy, expire hrtimers: |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 1198 | * |
| 1199 | * For HRT its the fall back code to run the softirq in the timer |
| 1200 | * softirq context in case the hrtimer initialization failed or has |
| 1201 | * not been done yet. |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1202 | */ |
Peter Zijlstra | d3d7445 | 2008-01-25 21:08:31 +0100 | [diff] [blame] | 1203 | void hrtimer_run_pending(void) |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1204 | { |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 1205 | struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1206 | |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 1207 | if (hrtimer_hres_active()) |
| 1208 | return; |
| 1209 | |
Thomas Gleixner | 79bf2bb | 2007-02-16 01:28:03 -0800 | [diff] [blame] | 1210 | /* |
| 1211 | * This _is_ ugly: We have to check in the softirq context, |
| 1212 | * whether we can switch to highres and / or nohz mode. The |
| 1213 | * clocksource switch happens in the timer interrupt with |
| 1214 | * xtime_lock held. Notification from there only sets the |
| 1215 | * check bit in the tick_oneshot code, otherwise we might |
| 1216 | * deadlock vs. xtime_lock. |
| 1217 | */ |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 1218 | if (tick_check_oneshot_change(!hrtimer_is_hres_enabled())) |
Peter Zijlstra | d3d7445 | 2008-01-25 21:08:31 +0100 | [diff] [blame] | 1219 | hrtimer_switch_to_hres(); |
| 1220 | |
| 1221 | run_hrtimer_pending(cpu_base); |
| 1222 | } |
| 1223 | |
| 1224 | /* |
| 1225 | * Called from hardirq context every jiffy |
| 1226 | */ |
| 1227 | static inline void run_hrtimer_queue(struct hrtimer_cpu_base *cpu_base, |
| 1228 | int index) |
| 1229 | { |
| 1230 | struct rb_node *node; |
| 1231 | struct hrtimer_clock_base *base = &cpu_base->clock_base[index]; |
| 1232 | |
| 1233 | if (!base->first) |
| 1234 | return; |
| 1235 | |
| 1236 | if (base->get_softirq_time) |
| 1237 | base->softirq_time = base->get_softirq_time(); |
| 1238 | |
| 1239 | spin_lock(&cpu_base->lock); |
| 1240 | |
| 1241 | while ((node = base->first)) { |
| 1242 | struct hrtimer *timer; |
| 1243 | |
| 1244 | timer = rb_entry(node, struct hrtimer, node); |
| 1245 | if (base->softirq_time.tv64 <= timer->expires.tv64) |
| 1246 | break; |
| 1247 | |
| 1248 | if (timer->cb_mode == HRTIMER_CB_SOFTIRQ) { |
| 1249 | __remove_hrtimer(timer, base, HRTIMER_STATE_PENDING, 0); |
| 1250 | list_add_tail(&timer->cb_entry, |
| 1251 | &base->cpu_base->cb_pending); |
| 1252 | continue; |
| 1253 | } |
| 1254 | |
| 1255 | __run_hrtimer(timer); |
| 1256 | } |
| 1257 | spin_unlock(&cpu_base->lock); |
| 1258 | } |
| 1259 | |
| 1260 | void hrtimer_run_queues(void) |
| 1261 | { |
| 1262 | struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); |
| 1263 | int i; |
| 1264 | |
| 1265 | if (hrtimer_hres_active()) |
| 1266 | return; |
Thomas Gleixner | 79bf2bb | 2007-02-16 01:28:03 -0800 | [diff] [blame] | 1267 | |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 1268 | hrtimer_get_softirq_time(cpu_base); |
Thomas Gleixner | 92127c7 | 2006-03-26 01:38:05 -0800 | [diff] [blame] | 1269 | |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 1270 | for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) |
| 1271 | run_hrtimer_queue(cpu_base, i); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1272 | } |
| 1273 | |
| 1274 | /* |
Thomas Gleixner | 10c94ec | 2006-01-09 20:52:35 -0800 | [diff] [blame] | 1275 | * Sleep related functions: |
| 1276 | */ |
Thomas Gleixner | c9cb2e3 | 2007-02-16 01:27:49 -0800 | [diff] [blame] | 1277 | static enum hrtimer_restart hrtimer_wakeup(struct hrtimer *timer) |
Thomas Gleixner | 00362e3 | 2006-03-31 02:31:17 -0800 | [diff] [blame] | 1278 | { |
| 1279 | struct hrtimer_sleeper *t = |
| 1280 | container_of(timer, struct hrtimer_sleeper, timer); |
| 1281 | struct task_struct *task = t->task; |
| 1282 | |
| 1283 | t->task = NULL; |
| 1284 | if (task) |
| 1285 | wake_up_process(task); |
| 1286 | |
| 1287 | return HRTIMER_NORESTART; |
| 1288 | } |
| 1289 | |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 1290 | void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task) |
Thomas Gleixner | 00362e3 | 2006-03-31 02:31:17 -0800 | [diff] [blame] | 1291 | { |
| 1292 | sl->timer.function = hrtimer_wakeup; |
| 1293 | sl->task = task; |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 1294 | #ifdef CONFIG_HIGH_RES_TIMERS |
Peter Zijlstra | 37bb6cb | 2008-01-25 21:08:32 +0100 | [diff] [blame] | 1295 | sl->timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ; |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 1296 | #endif |
Thomas Gleixner | 00362e3 | 2006-03-31 02:31:17 -0800 | [diff] [blame] | 1297 | } |
| 1298 | |
Thomas Gleixner | 669d786 | 2006-03-31 02:31:19 -0800 | [diff] [blame] | 1299 | static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode) |
Thomas Gleixner | 10c94ec | 2006-01-09 20:52:35 -0800 | [diff] [blame] | 1300 | { |
Thomas Gleixner | 669d786 | 2006-03-31 02:31:19 -0800 | [diff] [blame] | 1301 | hrtimer_init_sleeper(t, current); |
Thomas Gleixner | 10c94ec | 2006-01-09 20:52:35 -0800 | [diff] [blame] | 1302 | |
Roman Zippel | 432569b | 2006-03-26 01:38:08 -0800 | [diff] [blame] | 1303 | do { |
| 1304 | set_current_state(TASK_INTERRUPTIBLE); |
| 1305 | hrtimer_start(&t->timer, t->timer.expires, mode); |
Peter Zijlstra | 37bb6cb | 2008-01-25 21:08:32 +0100 | [diff] [blame] | 1306 | if (!hrtimer_active(&t->timer)) |
| 1307 | t->task = NULL; |
Roman Zippel | 432569b | 2006-03-26 01:38:08 -0800 | [diff] [blame] | 1308 | |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 1309 | if (likely(t->task)) |
| 1310 | schedule(); |
Roman Zippel | 432569b | 2006-03-26 01:38:08 -0800 | [diff] [blame] | 1311 | |
Thomas Gleixner | 669d786 | 2006-03-31 02:31:19 -0800 | [diff] [blame] | 1312 | hrtimer_cancel(&t->timer); |
Thomas Gleixner | c9cb2e3 | 2007-02-16 01:27:49 -0800 | [diff] [blame] | 1313 | mode = HRTIMER_MODE_ABS; |
Roman Zippel | 432569b | 2006-03-26 01:38:08 -0800 | [diff] [blame] | 1314 | |
Thomas Gleixner | 669d786 | 2006-03-31 02:31:19 -0800 | [diff] [blame] | 1315 | } while (t->task && !signal_pending(current)); |
| 1316 | |
Peter Zijlstra | 3588a08 | 2008-02-01 17:45:13 +0100 | [diff] [blame] | 1317 | __set_current_state(TASK_RUNNING); |
| 1318 | |
Thomas Gleixner | 669d786 | 2006-03-31 02:31:19 -0800 | [diff] [blame] | 1319 | return t->task == NULL; |
Thomas Gleixner | 10c94ec | 2006-01-09 20:52:35 -0800 | [diff] [blame] | 1320 | } |
| 1321 | |
Toyo Abe | 1711ef38 | 2006-09-29 02:00:28 -0700 | [diff] [blame] | 1322 | long __sched hrtimer_nanosleep_restart(struct restart_block *restart) |
Thomas Gleixner | 10c94ec | 2006-01-09 20:52:35 -0800 | [diff] [blame] | 1323 | { |
Thomas Gleixner | 669d786 | 2006-03-31 02:31:19 -0800 | [diff] [blame] | 1324 | struct hrtimer_sleeper t; |
Anton Blanchard | 04c2271 | 2007-10-15 16:06:04 -0500 | [diff] [blame] | 1325 | struct timespec *rmtp; |
Roman Zippel | 432569b | 2006-03-26 01:38:08 -0800 | [diff] [blame] | 1326 | ktime_t time; |
Thomas Gleixner | 10c94ec | 2006-01-09 20:52:35 -0800 | [diff] [blame] | 1327 | |
| 1328 | restart->fn = do_no_restart_syscall; |
| 1329 | |
Thomas Gleixner | c9cb2e3 | 2007-02-16 01:27:49 -0800 | [diff] [blame] | 1330 | hrtimer_init(&t.timer, restart->arg0, HRTIMER_MODE_ABS); |
Toyo Abe | 1711ef38 | 2006-09-29 02:00:28 -0700 | [diff] [blame] | 1331 | t.timer.expires.tv64 = ((u64)restart->arg3 << 32) | (u64) restart->arg2; |
Thomas Gleixner | 10c94ec | 2006-01-09 20:52:35 -0800 | [diff] [blame] | 1332 | |
Thomas Gleixner | c9cb2e3 | 2007-02-16 01:27:49 -0800 | [diff] [blame] | 1333 | if (do_nanosleep(&t, HRTIMER_MODE_ABS)) |
Thomas Gleixner | 10c94ec | 2006-01-09 20:52:35 -0800 | [diff] [blame] | 1334 | return 0; |
| 1335 | |
Anton Blanchard | 04c2271 | 2007-10-15 16:06:04 -0500 | [diff] [blame] | 1336 | rmtp = (struct timespec *)restart->arg1; |
Roman Zippel | 432569b | 2006-03-26 01:38:08 -0800 | [diff] [blame] | 1337 | if (rmtp) { |
| 1338 | time = ktime_sub(t.timer.expires, t.timer.base->get_time()); |
| 1339 | if (time.tv64 <= 0) |
| 1340 | return 0; |
Anton Blanchard | 04c2271 | 2007-10-15 16:06:04 -0500 | [diff] [blame] | 1341 | *rmtp = ktime_to_timespec(time); |
Roman Zippel | 432569b | 2006-03-26 01:38:08 -0800 | [diff] [blame] | 1342 | } |
Thomas Gleixner | 10c94ec | 2006-01-09 20:52:35 -0800 | [diff] [blame] | 1343 | |
Toyo Abe | 1711ef38 | 2006-09-29 02:00:28 -0700 | [diff] [blame] | 1344 | restart->fn = hrtimer_nanosleep_restart; |
Thomas Gleixner | 10c94ec | 2006-01-09 20:52:35 -0800 | [diff] [blame] | 1345 | |
| 1346 | /* The other values in restart are already filled in */ |
| 1347 | return -ERESTART_RESTARTBLOCK; |
| 1348 | } |
| 1349 | |
Anton Blanchard | 04c2271 | 2007-10-15 16:06:04 -0500 | [diff] [blame] | 1350 | long hrtimer_nanosleep(struct timespec *rqtp, struct timespec *rmtp, |
Thomas Gleixner | 10c94ec | 2006-01-09 20:52:35 -0800 | [diff] [blame] | 1351 | const enum hrtimer_mode mode, const clockid_t clockid) |
| 1352 | { |
| 1353 | struct restart_block *restart; |
Thomas Gleixner | 669d786 | 2006-03-31 02:31:19 -0800 | [diff] [blame] | 1354 | struct hrtimer_sleeper t; |
Thomas Gleixner | 10c94ec | 2006-01-09 20:52:35 -0800 | [diff] [blame] | 1355 | ktime_t rem; |
| 1356 | |
Roman Zippel | 432569b | 2006-03-26 01:38:08 -0800 | [diff] [blame] | 1357 | hrtimer_init(&t.timer, clockid, mode); |
| 1358 | t.timer.expires = timespec_to_ktime(*rqtp); |
| 1359 | if (do_nanosleep(&t, mode)) |
Thomas Gleixner | 10c94ec | 2006-01-09 20:52:35 -0800 | [diff] [blame] | 1360 | return 0; |
| 1361 | |
George Anzinger | 7978672c | 2006-02-01 03:05:11 -0800 | [diff] [blame] | 1362 | /* Absolute timers do not update the rmtp value and restart: */ |
Thomas Gleixner | c9cb2e3 | 2007-02-16 01:27:49 -0800 | [diff] [blame] | 1363 | if (mode == HRTIMER_MODE_ABS) |
Thomas Gleixner | 10c94ec | 2006-01-09 20:52:35 -0800 | [diff] [blame] | 1364 | return -ERESTARTNOHAND; |
| 1365 | |
Roman Zippel | 432569b | 2006-03-26 01:38:08 -0800 | [diff] [blame] | 1366 | if (rmtp) { |
| 1367 | rem = ktime_sub(t.timer.expires, t.timer.base->get_time()); |
| 1368 | if (rem.tv64 <= 0) |
| 1369 | return 0; |
Anton Blanchard | 04c2271 | 2007-10-15 16:06:04 -0500 | [diff] [blame] | 1370 | *rmtp = ktime_to_timespec(rem); |
Roman Zippel | 432569b | 2006-03-26 01:38:08 -0800 | [diff] [blame] | 1371 | } |
Thomas Gleixner | 10c94ec | 2006-01-09 20:52:35 -0800 | [diff] [blame] | 1372 | |
| 1373 | restart = ¤t_thread_info()->restart_block; |
Toyo Abe | 1711ef38 | 2006-09-29 02:00:28 -0700 | [diff] [blame] | 1374 | restart->fn = hrtimer_nanosleep_restart; |
| 1375 | restart->arg0 = (unsigned long) t.timer.base->index; |
| 1376 | restart->arg1 = (unsigned long) rmtp; |
| 1377 | restart->arg2 = t.timer.expires.tv64 & 0xFFFFFFFF; |
| 1378 | restart->arg3 = t.timer.expires.tv64 >> 32; |
Thomas Gleixner | 10c94ec | 2006-01-09 20:52:35 -0800 | [diff] [blame] | 1379 | |
| 1380 | return -ERESTART_RESTARTBLOCK; |
| 1381 | } |
| 1382 | |
Thomas Gleixner | 6ba1b91 | 2006-01-09 20:52:36 -0800 | [diff] [blame] | 1383 | asmlinkage long |
| 1384 | sys_nanosleep(struct timespec __user *rqtp, struct timespec __user *rmtp) |
| 1385 | { |
Anton Blanchard | 04c2271 | 2007-10-15 16:06:04 -0500 | [diff] [blame] | 1386 | struct timespec tu, rmt; |
| 1387 | int ret; |
Thomas Gleixner | 6ba1b91 | 2006-01-09 20:52:36 -0800 | [diff] [blame] | 1388 | |
| 1389 | if (copy_from_user(&tu, rqtp, sizeof(tu))) |
| 1390 | return -EFAULT; |
| 1391 | |
| 1392 | if (!timespec_valid(&tu)) |
| 1393 | return -EINVAL; |
| 1394 | |
Anton Blanchard | 04c2271 | 2007-10-15 16:06:04 -0500 | [diff] [blame] | 1395 | ret = hrtimer_nanosleep(&tu, rmtp ? &rmt : NULL, HRTIMER_MODE_REL, |
| 1396 | CLOCK_MONOTONIC); |
| 1397 | |
| 1398 | if (ret && rmtp) { |
| 1399 | if (copy_to_user(rmtp, &rmt, sizeof(*rmtp))) |
| 1400 | return -EFAULT; |
| 1401 | } |
| 1402 | |
| 1403 | return ret; |
Thomas Gleixner | 6ba1b91 | 2006-01-09 20:52:36 -0800 | [diff] [blame] | 1404 | } |
| 1405 | |
Thomas Gleixner | 10c94ec | 2006-01-09 20:52:35 -0800 | [diff] [blame] | 1406 | /* |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1407 | * Functions related to boot-time initialization: |
| 1408 | */ |
Randy Dunlap | 0ec160d | 2008-01-21 17:18:24 -0800 | [diff] [blame] | 1409 | static void __cpuinit init_hrtimers_cpu(int cpu) |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1410 | { |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 1411 | struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1412 | int i; |
| 1413 | |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 1414 | spin_lock_init(&cpu_base->lock); |
| 1415 | lockdep_set_class(&cpu_base->lock, &cpu_base->lock_key); |
| 1416 | |
| 1417 | for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) |
| 1418 | cpu_base->clock_base[i].cpu_base = cpu_base; |
| 1419 | |
Peter Zijlstra | d3d7445 | 2008-01-25 21:08:31 +0100 | [diff] [blame] | 1420 | INIT_LIST_HEAD(&cpu_base->cb_pending); |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 1421 | hrtimer_init_hres(cpu_base); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1422 | } |
| 1423 | |
| 1424 | #ifdef CONFIG_HOTPLUG_CPU |
| 1425 | |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 1426 | static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base, |
| 1427 | struct hrtimer_clock_base *new_base) |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1428 | { |
| 1429 | struct hrtimer *timer; |
| 1430 | struct rb_node *node; |
| 1431 | |
| 1432 | while ((node = rb_first(&old_base->active))) { |
| 1433 | timer = rb_entry(node, struct hrtimer, node); |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 1434 | BUG_ON(hrtimer_callback_running(timer)); |
| 1435 | __remove_hrtimer(timer, old_base, HRTIMER_STATE_INACTIVE, 0); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1436 | timer->base = new_base; |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 1437 | /* |
| 1438 | * Enqueue the timer. Allow reprogramming of the event device |
| 1439 | */ |
| 1440 | enqueue_hrtimer(timer, new_base, 1); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1441 | } |
| 1442 | } |
| 1443 | |
| 1444 | static void migrate_hrtimers(int cpu) |
| 1445 | { |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 1446 | struct hrtimer_cpu_base *old_base, *new_base; |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1447 | int i; |
| 1448 | |
| 1449 | BUG_ON(cpu_online(cpu)); |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 1450 | old_base = &per_cpu(hrtimer_bases, cpu); |
| 1451 | new_base = &get_cpu_var(hrtimer_bases); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1452 | |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 1453 | tick_cancel_sched_timer(cpu); |
| 1454 | |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1455 | local_irq_disable(); |
Heiko Carstens | e81ce1f | 2007-03-05 00:30:51 -0800 | [diff] [blame] | 1456 | double_spin_lock(&new_base->lock, &old_base->lock, |
| 1457 | smp_processor_id() < cpu); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1458 | |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 1459 | for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { |
Thomas Gleixner | 3c8aa39 | 2007-02-16 01:27:50 -0800 | [diff] [blame] | 1460 | migrate_hrtimer_list(&old_base->clock_base[i], |
| 1461 | &new_base->clock_base[i]); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1462 | } |
| 1463 | |
Heiko Carstens | e81ce1f | 2007-03-05 00:30:51 -0800 | [diff] [blame] | 1464 | double_spin_unlock(&new_base->lock, &old_base->lock, |
| 1465 | smp_processor_id() < cpu); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1466 | local_irq_enable(); |
| 1467 | put_cpu_var(hrtimer_bases); |
| 1468 | } |
| 1469 | #endif /* CONFIG_HOTPLUG_CPU */ |
| 1470 | |
Chandra Seetharaman | 8c78f30 | 2006-07-30 03:03:35 -0700 | [diff] [blame] | 1471 | static int __cpuinit hrtimer_cpu_notify(struct notifier_block *self, |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1472 | unsigned long action, void *hcpu) |
| 1473 | { |
David Miller | 7713a7d | 2007-07-16 17:17:44 -0700 | [diff] [blame] | 1474 | unsigned int cpu = (long)hcpu; |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1475 | |
| 1476 | switch (action) { |
| 1477 | |
| 1478 | case CPU_UP_PREPARE: |
Rafael J. Wysocki | 8bb7844 | 2007-05-09 02:35:10 -0700 | [diff] [blame] | 1479 | case CPU_UP_PREPARE_FROZEN: |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1480 | init_hrtimers_cpu(cpu); |
| 1481 | break; |
| 1482 | |
| 1483 | #ifdef CONFIG_HOTPLUG_CPU |
| 1484 | case CPU_DEAD: |
Rafael J. Wysocki | 8bb7844 | 2007-05-09 02:35:10 -0700 | [diff] [blame] | 1485 | case CPU_DEAD_FROZEN: |
Thomas Gleixner | d316c57 | 2007-02-16 01:28:00 -0800 | [diff] [blame] | 1486 | clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DEAD, &cpu); |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1487 | migrate_hrtimers(cpu); |
| 1488 | break; |
| 1489 | #endif |
| 1490 | |
| 1491 | default: |
| 1492 | break; |
| 1493 | } |
| 1494 | |
| 1495 | return NOTIFY_OK; |
| 1496 | } |
| 1497 | |
Chandra Seetharaman | 8c78f30 | 2006-07-30 03:03:35 -0700 | [diff] [blame] | 1498 | static struct notifier_block __cpuinitdata hrtimers_nb = { |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1499 | .notifier_call = hrtimer_cpu_notify, |
| 1500 | }; |
| 1501 | |
| 1502 | void __init hrtimers_init(void) |
| 1503 | { |
| 1504 | hrtimer_cpu_notify(&hrtimers_nb, (unsigned long)CPU_UP_PREPARE, |
| 1505 | (void *)(long)smp_processor_id()); |
| 1506 | register_cpu_notifier(&hrtimers_nb); |
Thomas Gleixner | 54cdfdb | 2007-02-16 01:28:11 -0800 | [diff] [blame] | 1507 | #ifdef CONFIG_HIGH_RES_TIMERS |
| 1508 | open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq, NULL); |
| 1509 | #endif |
Thomas Gleixner | c0a3132 | 2006-01-09 20:52:32 -0800 | [diff] [blame] | 1510 | } |
| 1511 | |