Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * arch/s390/kernel/vtime.c |
| 3 | * Virtual cpu timer based timer functions. |
| 4 | * |
| 5 | * S390 version |
| 6 | * Copyright (C) 2004 IBM Deutschland Entwicklung GmbH, IBM Corporation |
| 7 | * Author(s): Jan Glauber <jan.glauber@de.ibm.com> |
| 8 | */ |
| 9 | |
| 10 | #include <linux/config.h> |
| 11 | #include <linux/module.h> |
| 12 | #include <linux/kernel.h> |
| 13 | #include <linux/time.h> |
| 14 | #include <linux/delay.h> |
| 15 | #include <linux/init.h> |
| 16 | #include <linux/smp.h> |
| 17 | #include <linux/types.h> |
| 18 | #include <linux/timex.h> |
| 19 | #include <linux/notifier.h> |
| 20 | #include <linux/kernel_stat.h> |
| 21 | #include <linux/rcupdate.h> |
| 22 | #include <linux/posix-timers.h> |
| 23 | |
| 24 | #include <asm/s390_ext.h> |
| 25 | #include <asm/timer.h> |
| 26 | |
| 27 | #define VTIMER_MAGIC (TIMER_MAGIC + 1) |
| 28 | static ext_int_info_t ext_int_info_timer; |
| 29 | DEFINE_PER_CPU(struct vtimer_queue, virt_cpu_timer); |
| 30 | |
| 31 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING |
| 32 | /* |
| 33 | * Update process times based on virtual cpu times stored by entry.S |
| 34 | * to the lowcore fields user_timer, system_timer & steal_clock. |
| 35 | */ |
| 36 | void account_user_vtime(struct task_struct *tsk) |
| 37 | { |
| 38 | cputime_t cputime; |
| 39 | __u64 timer, clock; |
| 40 | int rcu_user_flag; |
| 41 | |
| 42 | timer = S390_lowcore.last_update_timer; |
| 43 | clock = S390_lowcore.last_update_clock; |
| 44 | asm volatile (" STPT %0\n" /* Store current cpu timer value */ |
| 45 | " STCK %1" /* Store current tod clock value */ |
| 46 | : "=m" (S390_lowcore.last_update_timer), |
| 47 | "=m" (S390_lowcore.last_update_clock) ); |
| 48 | S390_lowcore.system_timer += timer - S390_lowcore.last_update_timer; |
| 49 | S390_lowcore.steal_clock += S390_lowcore.last_update_clock - clock; |
| 50 | |
| 51 | cputime = S390_lowcore.user_timer >> 12; |
| 52 | rcu_user_flag = cputime != 0; |
| 53 | S390_lowcore.user_timer -= cputime << 12; |
| 54 | S390_lowcore.steal_clock -= cputime << 12; |
| 55 | account_user_time(tsk, cputime); |
| 56 | |
| 57 | cputime = S390_lowcore.system_timer >> 12; |
| 58 | S390_lowcore.system_timer -= cputime << 12; |
| 59 | S390_lowcore.steal_clock -= cputime << 12; |
| 60 | account_system_time(tsk, HARDIRQ_OFFSET, cputime); |
| 61 | |
| 62 | cputime = S390_lowcore.steal_clock; |
| 63 | if ((__s64) cputime > 0) { |
| 64 | cputime >>= 12; |
| 65 | S390_lowcore.steal_clock -= cputime << 12; |
| 66 | account_steal_time(tsk, cputime); |
| 67 | } |
| 68 | |
| 69 | run_local_timers(); |
| 70 | if (rcu_pending(smp_processor_id())) |
| 71 | rcu_check_callbacks(smp_processor_id(), rcu_user_flag); |
| 72 | scheduler_tick(); |
| 73 | run_posix_cpu_timers(tsk); |
| 74 | } |
| 75 | |
| 76 | /* |
| 77 | * Update process times based on virtual cpu times stored by entry.S |
| 78 | * to the lowcore fields user_timer, system_timer & steal_clock. |
| 79 | */ |
| 80 | void account_system_vtime(struct task_struct *tsk) |
| 81 | { |
| 82 | cputime_t cputime; |
| 83 | __u64 timer; |
| 84 | |
| 85 | timer = S390_lowcore.last_update_timer; |
| 86 | asm volatile (" STPT %0" /* Store current cpu timer value */ |
| 87 | : "=m" (S390_lowcore.last_update_timer) ); |
| 88 | S390_lowcore.system_timer += timer - S390_lowcore.last_update_timer; |
| 89 | |
| 90 | cputime = S390_lowcore.system_timer >> 12; |
| 91 | S390_lowcore.system_timer -= cputime << 12; |
| 92 | S390_lowcore.steal_clock -= cputime << 12; |
| 93 | account_system_time(tsk, 0, cputime); |
| 94 | } |
| 95 | |
| 96 | static inline void set_vtimer(__u64 expires) |
| 97 | { |
| 98 | __u64 timer; |
| 99 | |
| 100 | asm volatile (" STPT %0\n" /* Store current cpu timer value */ |
| 101 | " SPT %1" /* Set new value immediatly afterwards */ |
| 102 | : "=m" (timer) : "m" (expires) ); |
| 103 | S390_lowcore.system_timer += S390_lowcore.last_update_timer - timer; |
| 104 | S390_lowcore.last_update_timer = expires; |
| 105 | |
| 106 | /* store expire time for this CPU timer */ |
| 107 | per_cpu(virt_cpu_timer, smp_processor_id()).to_expire = expires; |
| 108 | } |
| 109 | #else |
| 110 | static inline void set_vtimer(__u64 expires) |
| 111 | { |
| 112 | S390_lowcore.last_update_timer = expires; |
| 113 | asm volatile ("SPT %0" : : "m" (S390_lowcore.last_update_timer)); |
| 114 | |
| 115 | /* store expire time for this CPU timer */ |
| 116 | per_cpu(virt_cpu_timer, smp_processor_id()).to_expire = expires; |
| 117 | } |
| 118 | #endif |
| 119 | |
| 120 | static void start_cpu_timer(void) |
| 121 | { |
| 122 | struct vtimer_queue *vt_list; |
| 123 | |
| 124 | vt_list = &per_cpu(virt_cpu_timer, smp_processor_id()); |
Martin Schwidefsky | 4b7e070 | 2005-05-01 08:58:57 -0700 | [diff] [blame] | 125 | |
| 126 | /* CPU timer interrupt is pending, don't reprogramm it */ |
| 127 | if (vt_list->idle & 1LL<<63) |
| 128 | return; |
| 129 | |
| 130 | if (!list_empty(&vt_list->list)) |
| 131 | set_vtimer(vt_list->idle); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 132 | } |
| 133 | |
| 134 | static void stop_cpu_timer(void) |
| 135 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 136 | struct vtimer_queue *vt_list; |
| 137 | |
| 138 | vt_list = &per_cpu(virt_cpu_timer, smp_processor_id()); |
| 139 | |
| 140 | /* nothing to do */ |
| 141 | if (list_empty(&vt_list->list)) { |
| 142 | vt_list->idle = VTIMER_MAX_SLICE; |
| 143 | goto fire; |
| 144 | } |
| 145 | |
Martin Schwidefsky | 4b7e070 | 2005-05-01 08:58:57 -0700 | [diff] [blame] | 146 | /* store the actual expire value */ |
| 147 | asm volatile ("STPT %0" : "=m" (vt_list->idle)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | |
| 149 | /* |
Martin Schwidefsky | 4b7e070 | 2005-05-01 08:58:57 -0700 | [diff] [blame] | 150 | * If the CPU timer is negative we don't reprogramm |
| 151 | * it because we will get instantly an interrupt. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 152 | */ |
Martin Schwidefsky | 4b7e070 | 2005-05-01 08:58:57 -0700 | [diff] [blame] | 153 | if (vt_list->idle & 1LL<<63) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 154 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | |
Martin Schwidefsky | 4b7e070 | 2005-05-01 08:58:57 -0700 | [diff] [blame] | 156 | vt_list->offset += vt_list->to_expire - vt_list->idle; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 157 | |
| 158 | /* |
| 159 | * We cannot halt the CPU timer, we just write a value that |
| 160 | * nearly never expires (only after 71 years) and re-write |
| 161 | * the stored expire value if we continue the timer |
| 162 | */ |
| 163 | fire: |
| 164 | set_vtimer(VTIMER_MAX_SLICE); |
| 165 | } |
| 166 | |
| 167 | /* |
| 168 | * Sorted add to a list. List is linear searched until first bigger |
| 169 | * element is found. |
| 170 | */ |
| 171 | static void list_add_sorted(struct vtimer_list *timer, struct list_head *head) |
| 172 | { |
| 173 | struct vtimer_list *event; |
| 174 | |
| 175 | list_for_each_entry(event, head, entry) { |
| 176 | if (event->expires > timer->expires) { |
| 177 | list_add_tail(&timer->entry, &event->entry); |
| 178 | return; |
| 179 | } |
| 180 | } |
| 181 | list_add_tail(&timer->entry, head); |
| 182 | } |
| 183 | |
| 184 | /* |
| 185 | * Do the callback functions of expired vtimer events. |
| 186 | * Called from within the interrupt handler. |
| 187 | */ |
| 188 | static void do_callbacks(struct list_head *cb_list, struct pt_regs *regs) |
| 189 | { |
| 190 | struct vtimer_queue *vt_list; |
| 191 | struct vtimer_list *event, *tmp; |
| 192 | void (*fn)(unsigned long, struct pt_regs*); |
| 193 | unsigned long data; |
| 194 | |
| 195 | if (list_empty(cb_list)) |
| 196 | return; |
| 197 | |
| 198 | vt_list = &per_cpu(virt_cpu_timer, smp_processor_id()); |
| 199 | |
| 200 | list_for_each_entry_safe(event, tmp, cb_list, entry) { |
| 201 | fn = event->function; |
| 202 | data = event->data; |
| 203 | fn(data, regs); |
| 204 | |
| 205 | if (!event->interval) |
| 206 | /* delete one shot timer */ |
| 207 | list_del_init(&event->entry); |
| 208 | else { |
| 209 | /* move interval timer back to list */ |
| 210 | spin_lock(&vt_list->lock); |
| 211 | list_del_init(&event->entry); |
| 212 | list_add_sorted(event, &vt_list->list); |
| 213 | spin_unlock(&vt_list->lock); |
| 214 | } |
| 215 | } |
| 216 | } |
| 217 | |
| 218 | /* |
| 219 | * Handler for the virtual CPU timer. |
| 220 | */ |
| 221 | static void do_cpu_timer_interrupt(struct pt_regs *regs, __u16 error_code) |
| 222 | { |
| 223 | int cpu; |
| 224 | __u64 next, delta; |
| 225 | struct vtimer_queue *vt_list; |
| 226 | struct vtimer_list *event, *tmp; |
| 227 | struct list_head *ptr; |
| 228 | /* the callback queue */ |
| 229 | struct list_head cb_list; |
| 230 | |
| 231 | INIT_LIST_HEAD(&cb_list); |
| 232 | cpu = smp_processor_id(); |
| 233 | vt_list = &per_cpu(virt_cpu_timer, cpu); |
| 234 | |
| 235 | /* walk timer list, fire all expired events */ |
| 236 | spin_lock(&vt_list->lock); |
| 237 | |
| 238 | if (vt_list->to_expire < VTIMER_MAX_SLICE) |
| 239 | vt_list->offset += vt_list->to_expire; |
| 240 | |
| 241 | list_for_each_entry_safe(event, tmp, &vt_list->list, entry) { |
| 242 | if (event->expires > vt_list->offset) |
| 243 | /* found first unexpired event, leave */ |
| 244 | break; |
| 245 | |
| 246 | /* re-charge interval timer, we have to add the offset */ |
| 247 | if (event->interval) |
| 248 | event->expires = event->interval + vt_list->offset; |
| 249 | |
| 250 | /* move expired timer to the callback queue */ |
| 251 | list_move_tail(&event->entry, &cb_list); |
| 252 | } |
| 253 | spin_unlock(&vt_list->lock); |
| 254 | do_callbacks(&cb_list, regs); |
| 255 | |
| 256 | /* next event is first in list */ |
| 257 | spin_lock(&vt_list->lock); |
| 258 | if (!list_empty(&vt_list->list)) { |
| 259 | ptr = vt_list->list.next; |
| 260 | event = list_entry(ptr, struct vtimer_list, entry); |
| 261 | next = event->expires - vt_list->offset; |
| 262 | |
| 263 | /* add the expired time from this interrupt handler |
| 264 | * and the callback functions |
| 265 | */ |
| 266 | asm volatile ("STPT %0" : "=m" (delta)); |
| 267 | delta = 0xffffffffffffffffLL - delta + 1; |
| 268 | vt_list->offset += delta; |
| 269 | next -= delta; |
| 270 | } else { |
| 271 | vt_list->offset = 0; |
| 272 | next = VTIMER_MAX_SLICE; |
| 273 | } |
| 274 | spin_unlock(&vt_list->lock); |
| 275 | set_vtimer(next); |
| 276 | } |
| 277 | |
| 278 | void init_virt_timer(struct vtimer_list *timer) |
| 279 | { |
| 280 | timer->magic = VTIMER_MAGIC; |
| 281 | timer->function = NULL; |
| 282 | INIT_LIST_HEAD(&timer->entry); |
| 283 | spin_lock_init(&timer->lock); |
| 284 | } |
| 285 | EXPORT_SYMBOL(init_virt_timer); |
| 286 | |
| 287 | static inline int check_vtimer(struct vtimer_list *timer) |
| 288 | { |
| 289 | if (timer->magic != VTIMER_MAGIC) |
| 290 | return -EINVAL; |
| 291 | return 0; |
| 292 | } |
| 293 | |
| 294 | static inline int vtimer_pending(struct vtimer_list *timer) |
| 295 | { |
| 296 | return (!list_empty(&timer->entry)); |
| 297 | } |
| 298 | |
| 299 | /* |
| 300 | * this function should only run on the specified CPU |
| 301 | */ |
| 302 | static void internal_add_vtimer(struct vtimer_list *timer) |
| 303 | { |
| 304 | unsigned long flags; |
| 305 | __u64 done; |
| 306 | struct vtimer_list *event; |
| 307 | struct vtimer_queue *vt_list; |
| 308 | |
| 309 | vt_list = &per_cpu(virt_cpu_timer, timer->cpu); |
| 310 | spin_lock_irqsave(&vt_list->lock, flags); |
| 311 | |
| 312 | if (timer->cpu != smp_processor_id()) |
| 313 | printk("internal_add_vtimer: BUG, running on wrong CPU"); |
| 314 | |
| 315 | /* if list is empty we only have to set the timer */ |
| 316 | if (list_empty(&vt_list->list)) { |
| 317 | /* reset the offset, this may happen if the last timer was |
| 318 | * just deleted by mod_virt_timer and the interrupt |
| 319 | * didn't happen until here |
| 320 | */ |
| 321 | vt_list->offset = 0; |
| 322 | goto fire; |
| 323 | } |
| 324 | |
| 325 | /* save progress */ |
| 326 | asm volatile ("STPT %0" : "=m" (done)); |
| 327 | |
| 328 | /* calculate completed work */ |
| 329 | done = vt_list->to_expire - done + vt_list->offset; |
| 330 | vt_list->offset = 0; |
| 331 | |
| 332 | list_for_each_entry(event, &vt_list->list, entry) |
| 333 | event->expires -= done; |
| 334 | |
| 335 | fire: |
| 336 | list_add_sorted(timer, &vt_list->list); |
| 337 | |
| 338 | /* get first element, which is the next vtimer slice */ |
| 339 | event = list_entry(vt_list->list.next, struct vtimer_list, entry); |
| 340 | |
| 341 | set_vtimer(event->expires); |
| 342 | spin_unlock_irqrestore(&vt_list->lock, flags); |
| 343 | /* release CPU aquired in prepare_vtimer or mod_virt_timer() */ |
| 344 | put_cpu(); |
| 345 | } |
| 346 | |
| 347 | static inline int prepare_vtimer(struct vtimer_list *timer) |
| 348 | { |
| 349 | if (check_vtimer(timer) || !timer->function) { |
| 350 | printk("add_virt_timer: uninitialized timer\n"); |
| 351 | return -EINVAL; |
| 352 | } |
| 353 | |
| 354 | if (!timer->expires || timer->expires > VTIMER_MAX_SLICE) { |
| 355 | printk("add_virt_timer: invalid timer expire value!\n"); |
| 356 | return -EINVAL; |
| 357 | } |
| 358 | |
| 359 | if (vtimer_pending(timer)) { |
| 360 | printk("add_virt_timer: timer pending\n"); |
| 361 | return -EBUSY; |
| 362 | } |
| 363 | |
| 364 | timer->cpu = get_cpu(); |
| 365 | return 0; |
| 366 | } |
| 367 | |
| 368 | /* |
| 369 | * add_virt_timer - add an oneshot virtual CPU timer |
| 370 | */ |
| 371 | void add_virt_timer(void *new) |
| 372 | { |
| 373 | struct vtimer_list *timer; |
| 374 | |
| 375 | timer = (struct vtimer_list *)new; |
| 376 | |
| 377 | if (prepare_vtimer(timer) < 0) |
| 378 | return; |
| 379 | |
| 380 | timer->interval = 0; |
| 381 | internal_add_vtimer(timer); |
| 382 | } |
| 383 | EXPORT_SYMBOL(add_virt_timer); |
| 384 | |
| 385 | /* |
| 386 | * add_virt_timer_int - add an interval virtual CPU timer |
| 387 | */ |
| 388 | void add_virt_timer_periodic(void *new) |
| 389 | { |
| 390 | struct vtimer_list *timer; |
| 391 | |
| 392 | timer = (struct vtimer_list *)new; |
| 393 | |
| 394 | if (prepare_vtimer(timer) < 0) |
| 395 | return; |
| 396 | |
| 397 | timer->interval = timer->expires; |
| 398 | internal_add_vtimer(timer); |
| 399 | } |
| 400 | EXPORT_SYMBOL(add_virt_timer_periodic); |
| 401 | |
| 402 | /* |
| 403 | * If we change a pending timer the function must be called on the CPU |
| 404 | * where the timer is running on, e.g. by smp_call_function_on() |
| 405 | * |
| 406 | * The original mod_timer adds the timer if it is not pending. For compatibility |
| 407 | * we do the same. The timer will be added on the current CPU as a oneshot timer. |
| 408 | * |
| 409 | * returns whether it has modified a pending timer (1) or not (0) |
| 410 | */ |
| 411 | int mod_virt_timer(struct vtimer_list *timer, __u64 expires) |
| 412 | { |
| 413 | struct vtimer_queue *vt_list; |
| 414 | unsigned long flags; |
| 415 | int cpu; |
| 416 | |
| 417 | if (check_vtimer(timer) || !timer->function) { |
| 418 | printk("mod_virt_timer: uninitialized timer\n"); |
| 419 | return -EINVAL; |
| 420 | } |
| 421 | |
| 422 | if (!expires || expires > VTIMER_MAX_SLICE) { |
| 423 | printk("mod_virt_timer: invalid expire range\n"); |
| 424 | return -EINVAL; |
| 425 | } |
| 426 | |
| 427 | /* |
| 428 | * This is a common optimization triggered by the |
| 429 | * networking code - if the timer is re-modified |
| 430 | * to be the same thing then just return: |
| 431 | */ |
| 432 | if (timer->expires == expires && vtimer_pending(timer)) |
| 433 | return 1; |
| 434 | |
| 435 | cpu = get_cpu(); |
| 436 | vt_list = &per_cpu(virt_cpu_timer, cpu); |
| 437 | |
| 438 | /* disable interrupts before test if timer is pending */ |
| 439 | spin_lock_irqsave(&vt_list->lock, flags); |
| 440 | |
| 441 | /* if timer isn't pending add it on the current CPU */ |
| 442 | if (!vtimer_pending(timer)) { |
| 443 | spin_unlock_irqrestore(&vt_list->lock, flags); |
| 444 | /* we do not activate an interval timer with mod_virt_timer */ |
| 445 | timer->interval = 0; |
| 446 | timer->expires = expires; |
| 447 | timer->cpu = cpu; |
| 448 | internal_add_vtimer(timer); |
| 449 | return 0; |
| 450 | } |
| 451 | |
| 452 | /* check if we run on the right CPU */ |
| 453 | if (timer->cpu != cpu) { |
| 454 | printk("mod_virt_timer: running on wrong CPU, check your code\n"); |
| 455 | spin_unlock_irqrestore(&vt_list->lock, flags); |
| 456 | put_cpu(); |
| 457 | return -EINVAL; |
| 458 | } |
| 459 | |
| 460 | list_del_init(&timer->entry); |
| 461 | timer->expires = expires; |
| 462 | |
| 463 | /* also change the interval if we have an interval timer */ |
| 464 | if (timer->interval) |
| 465 | timer->interval = expires; |
| 466 | |
| 467 | /* the timer can't expire anymore so we can release the lock */ |
| 468 | spin_unlock_irqrestore(&vt_list->lock, flags); |
| 469 | internal_add_vtimer(timer); |
| 470 | return 1; |
| 471 | } |
| 472 | EXPORT_SYMBOL(mod_virt_timer); |
| 473 | |
| 474 | /* |
| 475 | * delete a virtual timer |
| 476 | * |
| 477 | * returns whether the deleted timer was pending (1) or not (0) |
| 478 | */ |
| 479 | int del_virt_timer(struct vtimer_list *timer) |
| 480 | { |
| 481 | unsigned long flags; |
| 482 | struct vtimer_queue *vt_list; |
| 483 | |
| 484 | if (check_vtimer(timer)) { |
| 485 | printk("del_virt_timer: timer not initialized\n"); |
| 486 | return -EINVAL; |
| 487 | } |
| 488 | |
| 489 | /* check if timer is pending */ |
| 490 | if (!vtimer_pending(timer)) |
| 491 | return 0; |
| 492 | |
| 493 | vt_list = &per_cpu(virt_cpu_timer, timer->cpu); |
| 494 | spin_lock_irqsave(&vt_list->lock, flags); |
| 495 | |
| 496 | /* we don't interrupt a running timer, just let it expire! */ |
| 497 | list_del_init(&timer->entry); |
| 498 | |
| 499 | /* last timer removed */ |
| 500 | if (list_empty(&vt_list->list)) { |
| 501 | vt_list->to_expire = 0; |
| 502 | vt_list->offset = 0; |
| 503 | } |
| 504 | |
| 505 | spin_unlock_irqrestore(&vt_list->lock, flags); |
| 506 | return 1; |
| 507 | } |
| 508 | EXPORT_SYMBOL(del_virt_timer); |
| 509 | |
| 510 | /* |
| 511 | * Start the virtual CPU timer on the current CPU. |
| 512 | */ |
| 513 | void init_cpu_vtimer(void) |
| 514 | { |
| 515 | struct vtimer_queue *vt_list; |
| 516 | unsigned long cr0; |
| 517 | |
| 518 | /* kick the virtual timer */ |
| 519 | S390_lowcore.exit_timer = VTIMER_MAX_SLICE; |
| 520 | S390_lowcore.last_update_timer = VTIMER_MAX_SLICE; |
| 521 | asm volatile ("SPT %0" : : "m" (S390_lowcore.last_update_timer)); |
| 522 | asm volatile ("STCK %0" : "=m" (S390_lowcore.last_update_clock)); |
| 523 | __ctl_store(cr0, 0, 0); |
| 524 | cr0 |= 0x400; |
| 525 | __ctl_load(cr0, 0, 0); |
| 526 | |
| 527 | vt_list = &per_cpu(virt_cpu_timer, smp_processor_id()); |
| 528 | INIT_LIST_HEAD(&vt_list->list); |
| 529 | spin_lock_init(&vt_list->lock); |
| 530 | vt_list->to_expire = 0; |
| 531 | vt_list->offset = 0; |
| 532 | vt_list->idle = 0; |
| 533 | |
| 534 | } |
| 535 | |
| 536 | static int vtimer_idle_notify(struct notifier_block *self, |
| 537 | unsigned long action, void *hcpu) |
| 538 | { |
| 539 | switch (action) { |
| 540 | case CPU_IDLE: |
| 541 | stop_cpu_timer(); |
| 542 | break; |
| 543 | case CPU_NOT_IDLE: |
| 544 | start_cpu_timer(); |
| 545 | break; |
| 546 | } |
| 547 | return NOTIFY_OK; |
| 548 | } |
| 549 | |
| 550 | static struct notifier_block vtimer_idle_nb = { |
| 551 | .notifier_call = vtimer_idle_notify, |
| 552 | }; |
| 553 | |
| 554 | void __init vtime_init(void) |
| 555 | { |
| 556 | /* request the cpu timer external interrupt */ |
| 557 | if (register_early_external_interrupt(0x1005, do_cpu_timer_interrupt, |
| 558 | &ext_int_info_timer) != 0) |
| 559 | panic("Couldn't request external interrupt 0x1005"); |
| 560 | |
| 561 | if (register_idle_notifier(&vtimer_idle_nb)) |
| 562 | panic("Couldn't register idle notifier"); |
| 563 | |
| 564 | init_cpu_vtimer(); |
| 565 | } |
| 566 | |