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 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 10 | #include <linux/module.h> |
| 11 | #include <linux/kernel.h> |
| 12 | #include <linux/time.h> |
| 13 | #include <linux/delay.h> |
| 14 | #include <linux/init.h> |
| 15 | #include <linux/smp.h> |
| 16 | #include <linux/types.h> |
| 17 | #include <linux/timex.h> |
| 18 | #include <linux/notifier.h> |
| 19 | #include <linux/kernel_stat.h> |
| 20 | #include <linux/rcupdate.h> |
| 21 | #include <linux/posix-timers.h> |
| 22 | |
| 23 | #include <asm/s390_ext.h> |
| 24 | #include <asm/timer.h> |
Heiko Carstens | 5a489b9 | 2006-10-06 16:38:35 +0200 | [diff] [blame] | 25 | #include <asm/irq_regs.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 26 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | static ext_int_info_t ext_int_info_timer; |
Heiko Carstens | 2b67fc4 | 2007-02-05 21:16:47 +0100 | [diff] [blame] | 28 | static DEFINE_PER_CPU(struct vtimer_queue, virt_cpu_timer); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | |
| 30 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING |
| 31 | /* |
| 32 | * Update process times based on virtual cpu times stored by entry.S |
| 33 | * to the lowcore fields user_timer, system_timer & steal_clock. |
| 34 | */ |
Paul Mackerras | fa13a5a | 2007-11-09 22:39:38 +0100 | [diff] [blame] | 35 | void account_process_tick(struct task_struct *tsk, int user_tick) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | { |
| 37 | cputime_t cputime; |
| 38 | __u64 timer, clock; |
| 39 | int rcu_user_flag; |
| 40 | |
| 41 | timer = S390_lowcore.last_update_timer; |
| 42 | clock = S390_lowcore.last_update_clock; |
| 43 | asm volatile (" STPT %0\n" /* Store current cpu timer value */ |
| 44 | " STCK %1" /* Store current tod clock value */ |
| 45 | : "=m" (S390_lowcore.last_update_timer), |
| 46 | "=m" (S390_lowcore.last_update_clock) ); |
| 47 | S390_lowcore.system_timer += timer - S390_lowcore.last_update_timer; |
| 48 | S390_lowcore.steal_clock += S390_lowcore.last_update_clock - clock; |
| 49 | |
| 50 | cputime = S390_lowcore.user_timer >> 12; |
| 51 | rcu_user_flag = cputime != 0; |
| 52 | S390_lowcore.user_timer -= cputime << 12; |
| 53 | S390_lowcore.steal_clock -= cputime << 12; |
| 54 | account_user_time(tsk, cputime); |
| 55 | |
| 56 | cputime = S390_lowcore.system_timer >> 12; |
| 57 | S390_lowcore.system_timer -= cputime << 12; |
| 58 | S390_lowcore.steal_clock -= cputime << 12; |
| 59 | account_system_time(tsk, HARDIRQ_OFFSET, cputime); |
| 60 | |
| 61 | cputime = S390_lowcore.steal_clock; |
| 62 | if ((__s64) cputime > 0) { |
| 63 | cputime >>= 12; |
| 64 | S390_lowcore.steal_clock -= cputime << 12; |
| 65 | account_steal_time(tsk, cputime); |
| 66 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | } |
| 68 | |
| 69 | /* |
| 70 | * Update process times based on virtual cpu times stored by entry.S |
| 71 | * to the lowcore fields user_timer, system_timer & steal_clock. |
| 72 | */ |
Martin Schwidefsky | 1f1c12a | 2006-01-14 13:21:03 -0800 | [diff] [blame] | 73 | void account_vtime(struct task_struct *tsk) |
| 74 | { |
| 75 | cputime_t cputime; |
| 76 | __u64 timer; |
| 77 | |
| 78 | timer = S390_lowcore.last_update_timer; |
| 79 | asm volatile (" STPT %0" /* Store current cpu timer value */ |
| 80 | : "=m" (S390_lowcore.last_update_timer) ); |
| 81 | S390_lowcore.system_timer += timer - S390_lowcore.last_update_timer; |
| 82 | |
| 83 | cputime = S390_lowcore.user_timer >> 12; |
| 84 | S390_lowcore.user_timer -= cputime << 12; |
| 85 | S390_lowcore.steal_clock -= cputime << 12; |
| 86 | account_user_time(tsk, cputime); |
| 87 | |
| 88 | cputime = S390_lowcore.system_timer >> 12; |
| 89 | S390_lowcore.system_timer -= cputime << 12; |
| 90 | S390_lowcore.steal_clock -= cputime << 12; |
| 91 | account_system_time(tsk, 0, cputime); |
| 92 | } |
| 93 | |
| 94 | /* |
| 95 | * Update process times based on virtual cpu times stored by entry.S |
| 96 | * to the lowcore fields user_timer, system_timer & steal_clock. |
| 97 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | void account_system_vtime(struct task_struct *tsk) |
| 99 | { |
| 100 | cputime_t cputime; |
| 101 | __u64 timer; |
| 102 | |
| 103 | timer = S390_lowcore.last_update_timer; |
| 104 | asm volatile (" STPT %0" /* Store current cpu timer value */ |
| 105 | : "=m" (S390_lowcore.last_update_timer) ); |
| 106 | S390_lowcore.system_timer += timer - S390_lowcore.last_update_timer; |
| 107 | |
| 108 | cputime = S390_lowcore.system_timer >> 12; |
| 109 | S390_lowcore.system_timer -= cputime << 12; |
| 110 | S390_lowcore.steal_clock -= cputime << 12; |
| 111 | account_system_time(tsk, 0, cputime); |
| 112 | } |
Heiko Carstens | b0c632d | 2008-03-25 18:47:20 +0100 | [diff] [blame] | 113 | EXPORT_SYMBOL_GPL(account_system_vtime); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 114 | |
| 115 | static inline void set_vtimer(__u64 expires) |
| 116 | { |
| 117 | __u64 timer; |
| 118 | |
| 119 | asm volatile (" STPT %0\n" /* Store current cpu timer value */ |
| 120 | " SPT %1" /* Set new value immediatly afterwards */ |
| 121 | : "=m" (timer) : "m" (expires) ); |
| 122 | S390_lowcore.system_timer += S390_lowcore.last_update_timer - timer; |
| 123 | S390_lowcore.last_update_timer = expires; |
| 124 | |
| 125 | /* store expire time for this CPU timer */ |
Jan Glauber | db77aa5 | 2007-04-27 16:01:55 +0200 | [diff] [blame] | 126 | __get_cpu_var(virt_cpu_timer).to_expire = expires; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | } |
| 128 | #else |
| 129 | static inline void set_vtimer(__u64 expires) |
| 130 | { |
| 131 | S390_lowcore.last_update_timer = expires; |
| 132 | asm volatile ("SPT %0" : : "m" (S390_lowcore.last_update_timer)); |
| 133 | |
| 134 | /* store expire time for this CPU timer */ |
Jan Glauber | db77aa5 | 2007-04-27 16:01:55 +0200 | [diff] [blame] | 135 | __get_cpu_var(virt_cpu_timer).to_expire = expires; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 136 | } |
| 137 | #endif |
| 138 | |
| 139 | static void start_cpu_timer(void) |
| 140 | { |
| 141 | struct vtimer_queue *vt_list; |
| 142 | |
Jan Glauber | db77aa5 | 2007-04-27 16:01:55 +0200 | [diff] [blame] | 143 | vt_list = &__get_cpu_var(virt_cpu_timer); |
Martin Schwidefsky | 4b7e070 | 2005-05-01 08:58:57 -0700 | [diff] [blame] | 144 | |
| 145 | /* CPU timer interrupt is pending, don't reprogramm it */ |
| 146 | if (vt_list->idle & 1LL<<63) |
| 147 | return; |
| 148 | |
| 149 | if (!list_empty(&vt_list->list)) |
| 150 | set_vtimer(vt_list->idle); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 151 | } |
| 152 | |
| 153 | static void stop_cpu_timer(void) |
| 154 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | struct vtimer_queue *vt_list; |
| 156 | |
Jan Glauber | db77aa5 | 2007-04-27 16:01:55 +0200 | [diff] [blame] | 157 | vt_list = &__get_cpu_var(virt_cpu_timer); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 158 | |
| 159 | /* nothing to do */ |
| 160 | if (list_empty(&vt_list->list)) { |
| 161 | vt_list->idle = VTIMER_MAX_SLICE; |
| 162 | goto fire; |
| 163 | } |
| 164 | |
Martin Schwidefsky | 4b7e070 | 2005-05-01 08:58:57 -0700 | [diff] [blame] | 165 | /* store the actual expire value */ |
| 166 | asm volatile ("STPT %0" : "=m" (vt_list->idle)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 167 | |
| 168 | /* |
Martin Schwidefsky | 4b7e070 | 2005-05-01 08:58:57 -0700 | [diff] [blame] | 169 | * If the CPU timer is negative we don't reprogramm |
| 170 | * it because we will get instantly an interrupt. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 171 | */ |
Martin Schwidefsky | 4b7e070 | 2005-05-01 08:58:57 -0700 | [diff] [blame] | 172 | if (vt_list->idle & 1LL<<63) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 173 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 174 | |
Martin Schwidefsky | 4b7e070 | 2005-05-01 08:58:57 -0700 | [diff] [blame] | 175 | vt_list->offset += vt_list->to_expire - vt_list->idle; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 176 | |
| 177 | /* |
| 178 | * We cannot halt the CPU timer, we just write a value that |
| 179 | * nearly never expires (only after 71 years) and re-write |
| 180 | * the stored expire value if we continue the timer |
| 181 | */ |
| 182 | fire: |
| 183 | set_vtimer(VTIMER_MAX_SLICE); |
| 184 | } |
| 185 | |
| 186 | /* |
| 187 | * Sorted add to a list. List is linear searched until first bigger |
| 188 | * element is found. |
| 189 | */ |
| 190 | static void list_add_sorted(struct vtimer_list *timer, struct list_head *head) |
| 191 | { |
| 192 | struct vtimer_list *event; |
| 193 | |
| 194 | list_for_each_entry(event, head, entry) { |
| 195 | if (event->expires > timer->expires) { |
| 196 | list_add_tail(&timer->entry, &event->entry); |
| 197 | return; |
| 198 | } |
| 199 | } |
| 200 | list_add_tail(&timer->entry, head); |
| 201 | } |
| 202 | |
| 203 | /* |
| 204 | * Do the callback functions of expired vtimer events. |
| 205 | * Called from within the interrupt handler. |
| 206 | */ |
Heiko Carstens | 9d0a57c | 2006-10-11 15:31:26 +0200 | [diff] [blame] | 207 | static void do_callbacks(struct list_head *cb_list) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 208 | { |
| 209 | struct vtimer_queue *vt_list; |
| 210 | struct vtimer_list *event, *tmp; |
Heiko Carstens | 9d0a57c | 2006-10-11 15:31:26 +0200 | [diff] [blame] | 211 | void (*fn)(unsigned long); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 212 | unsigned long data; |
| 213 | |
| 214 | if (list_empty(cb_list)) |
| 215 | return; |
| 216 | |
Jan Glauber | db77aa5 | 2007-04-27 16:01:55 +0200 | [diff] [blame] | 217 | vt_list = &__get_cpu_var(virt_cpu_timer); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 218 | |
| 219 | list_for_each_entry_safe(event, tmp, cb_list, entry) { |
| 220 | fn = event->function; |
| 221 | data = event->data; |
Heiko Carstens | 9d0a57c | 2006-10-11 15:31:26 +0200 | [diff] [blame] | 222 | fn(data); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | |
| 224 | if (!event->interval) |
| 225 | /* delete one shot timer */ |
| 226 | list_del_init(&event->entry); |
| 227 | else { |
| 228 | /* move interval timer back to list */ |
| 229 | spin_lock(&vt_list->lock); |
| 230 | list_del_init(&event->entry); |
| 231 | list_add_sorted(event, &vt_list->list); |
| 232 | spin_unlock(&vt_list->lock); |
| 233 | } |
| 234 | } |
| 235 | } |
| 236 | |
| 237 | /* |
| 238 | * Handler for the virtual CPU timer. |
| 239 | */ |
Heiko Carstens | 5a489b9 | 2006-10-06 16:38:35 +0200 | [diff] [blame] | 240 | static void do_cpu_timer_interrupt(__u16 error_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 241 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 242 | __u64 next, delta; |
| 243 | struct vtimer_queue *vt_list; |
| 244 | struct vtimer_list *event, *tmp; |
| 245 | struct list_head *ptr; |
| 246 | /* the callback queue */ |
| 247 | struct list_head cb_list; |
| 248 | |
| 249 | INIT_LIST_HEAD(&cb_list); |
Jan Glauber | db77aa5 | 2007-04-27 16:01:55 +0200 | [diff] [blame] | 250 | vt_list = &__get_cpu_var(virt_cpu_timer); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 251 | |
| 252 | /* walk timer list, fire all expired events */ |
| 253 | spin_lock(&vt_list->lock); |
| 254 | |
| 255 | if (vt_list->to_expire < VTIMER_MAX_SLICE) |
| 256 | vt_list->offset += vt_list->to_expire; |
| 257 | |
| 258 | list_for_each_entry_safe(event, tmp, &vt_list->list, entry) { |
| 259 | if (event->expires > vt_list->offset) |
| 260 | /* found first unexpired event, leave */ |
| 261 | break; |
| 262 | |
| 263 | /* re-charge interval timer, we have to add the offset */ |
| 264 | if (event->interval) |
| 265 | event->expires = event->interval + vt_list->offset; |
| 266 | |
| 267 | /* move expired timer to the callback queue */ |
| 268 | list_move_tail(&event->entry, &cb_list); |
| 269 | } |
| 270 | spin_unlock(&vt_list->lock); |
Heiko Carstens | 9d0a57c | 2006-10-11 15:31:26 +0200 | [diff] [blame] | 271 | do_callbacks(&cb_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 272 | |
| 273 | /* next event is first in list */ |
| 274 | spin_lock(&vt_list->lock); |
| 275 | if (!list_empty(&vt_list->list)) { |
| 276 | ptr = vt_list->list.next; |
| 277 | event = list_entry(ptr, struct vtimer_list, entry); |
| 278 | next = event->expires - vt_list->offset; |
| 279 | |
| 280 | /* add the expired time from this interrupt handler |
| 281 | * and the callback functions |
| 282 | */ |
| 283 | asm volatile ("STPT %0" : "=m" (delta)); |
| 284 | delta = 0xffffffffffffffffLL - delta + 1; |
| 285 | vt_list->offset += delta; |
| 286 | next -= delta; |
| 287 | } else { |
| 288 | vt_list->offset = 0; |
| 289 | next = VTIMER_MAX_SLICE; |
| 290 | } |
| 291 | spin_unlock(&vt_list->lock); |
| 292 | set_vtimer(next); |
| 293 | } |
| 294 | |
| 295 | void init_virt_timer(struct vtimer_list *timer) |
| 296 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 297 | timer->function = NULL; |
| 298 | INIT_LIST_HEAD(&timer->entry); |
| 299 | spin_lock_init(&timer->lock); |
| 300 | } |
| 301 | EXPORT_SYMBOL(init_virt_timer); |
| 302 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 303 | static inline int vtimer_pending(struct vtimer_list *timer) |
| 304 | { |
| 305 | return (!list_empty(&timer->entry)); |
| 306 | } |
| 307 | |
| 308 | /* |
| 309 | * this function should only run on the specified CPU |
| 310 | */ |
| 311 | static void internal_add_vtimer(struct vtimer_list *timer) |
| 312 | { |
| 313 | unsigned long flags; |
| 314 | __u64 done; |
| 315 | struct vtimer_list *event; |
| 316 | struct vtimer_queue *vt_list; |
| 317 | |
| 318 | vt_list = &per_cpu(virt_cpu_timer, timer->cpu); |
| 319 | spin_lock_irqsave(&vt_list->lock, flags); |
| 320 | |
| 321 | if (timer->cpu != smp_processor_id()) |
| 322 | printk("internal_add_vtimer: BUG, running on wrong CPU"); |
| 323 | |
| 324 | /* if list is empty we only have to set the timer */ |
| 325 | if (list_empty(&vt_list->list)) { |
| 326 | /* reset the offset, this may happen if the last timer was |
| 327 | * just deleted by mod_virt_timer and the interrupt |
| 328 | * didn't happen until here |
| 329 | */ |
| 330 | vt_list->offset = 0; |
| 331 | goto fire; |
| 332 | } |
| 333 | |
| 334 | /* save progress */ |
| 335 | asm volatile ("STPT %0" : "=m" (done)); |
| 336 | |
| 337 | /* calculate completed work */ |
| 338 | done = vt_list->to_expire - done + vt_list->offset; |
| 339 | vt_list->offset = 0; |
| 340 | |
| 341 | list_for_each_entry(event, &vt_list->list, entry) |
| 342 | event->expires -= done; |
| 343 | |
| 344 | fire: |
| 345 | list_add_sorted(timer, &vt_list->list); |
| 346 | |
| 347 | /* get first element, which is the next vtimer slice */ |
| 348 | event = list_entry(vt_list->list.next, struct vtimer_list, entry); |
| 349 | |
| 350 | set_vtimer(event->expires); |
| 351 | spin_unlock_irqrestore(&vt_list->lock, flags); |
Andreas Mohr | d6e05ed | 2006-06-26 18:35:02 +0200 | [diff] [blame] | 352 | /* release CPU acquired in prepare_vtimer or mod_virt_timer() */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 353 | put_cpu(); |
| 354 | } |
| 355 | |
| 356 | static inline int prepare_vtimer(struct vtimer_list *timer) |
| 357 | { |
Andrew Morton | dfc4f94 | 2005-10-30 15:02:03 -0800 | [diff] [blame] | 358 | if (!timer->function) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 359 | printk("add_virt_timer: uninitialized timer\n"); |
| 360 | return -EINVAL; |
| 361 | } |
| 362 | |
| 363 | if (!timer->expires || timer->expires > VTIMER_MAX_SLICE) { |
| 364 | printk("add_virt_timer: invalid timer expire value!\n"); |
| 365 | return -EINVAL; |
| 366 | } |
| 367 | |
| 368 | if (vtimer_pending(timer)) { |
| 369 | printk("add_virt_timer: timer pending\n"); |
| 370 | return -EBUSY; |
| 371 | } |
| 372 | |
| 373 | timer->cpu = get_cpu(); |
| 374 | return 0; |
| 375 | } |
| 376 | |
| 377 | /* |
| 378 | * add_virt_timer - add an oneshot virtual CPU timer |
| 379 | */ |
| 380 | void add_virt_timer(void *new) |
| 381 | { |
| 382 | struct vtimer_list *timer; |
| 383 | |
| 384 | timer = (struct vtimer_list *)new; |
| 385 | |
| 386 | if (prepare_vtimer(timer) < 0) |
| 387 | return; |
| 388 | |
| 389 | timer->interval = 0; |
| 390 | internal_add_vtimer(timer); |
| 391 | } |
| 392 | EXPORT_SYMBOL(add_virt_timer); |
| 393 | |
| 394 | /* |
| 395 | * add_virt_timer_int - add an interval virtual CPU timer |
| 396 | */ |
| 397 | void add_virt_timer_periodic(void *new) |
| 398 | { |
| 399 | struct vtimer_list *timer; |
| 400 | |
| 401 | timer = (struct vtimer_list *)new; |
| 402 | |
| 403 | if (prepare_vtimer(timer) < 0) |
| 404 | return; |
| 405 | |
| 406 | timer->interval = timer->expires; |
| 407 | internal_add_vtimer(timer); |
| 408 | } |
| 409 | EXPORT_SYMBOL(add_virt_timer_periodic); |
| 410 | |
| 411 | /* |
| 412 | * If we change a pending timer the function must be called on the CPU |
Heiko Carstens | 3bb447f | 2007-07-27 12:29:08 +0200 | [diff] [blame] | 413 | * where the timer is running on, e.g. by smp_call_function_single() |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 414 | * |
| 415 | * The original mod_timer adds the timer if it is not pending. For compatibility |
| 416 | * we do the same. The timer will be added on the current CPU as a oneshot timer. |
| 417 | * |
| 418 | * returns whether it has modified a pending timer (1) or not (0) |
| 419 | */ |
| 420 | int mod_virt_timer(struct vtimer_list *timer, __u64 expires) |
| 421 | { |
| 422 | struct vtimer_queue *vt_list; |
| 423 | unsigned long flags; |
| 424 | int cpu; |
| 425 | |
Andrew Morton | dfc4f94 | 2005-10-30 15:02:03 -0800 | [diff] [blame] | 426 | if (!timer->function) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 427 | printk("mod_virt_timer: uninitialized timer\n"); |
| 428 | return -EINVAL; |
| 429 | } |
| 430 | |
| 431 | if (!expires || expires > VTIMER_MAX_SLICE) { |
| 432 | printk("mod_virt_timer: invalid expire range\n"); |
| 433 | return -EINVAL; |
| 434 | } |
| 435 | |
| 436 | /* |
| 437 | * This is a common optimization triggered by the |
| 438 | * networking code - if the timer is re-modified |
| 439 | * to be the same thing then just return: |
| 440 | */ |
| 441 | if (timer->expires == expires && vtimer_pending(timer)) |
| 442 | return 1; |
| 443 | |
| 444 | cpu = get_cpu(); |
| 445 | vt_list = &per_cpu(virt_cpu_timer, cpu); |
| 446 | |
| 447 | /* disable interrupts before test if timer is pending */ |
| 448 | spin_lock_irqsave(&vt_list->lock, flags); |
| 449 | |
| 450 | /* if timer isn't pending add it on the current CPU */ |
| 451 | if (!vtimer_pending(timer)) { |
| 452 | spin_unlock_irqrestore(&vt_list->lock, flags); |
| 453 | /* we do not activate an interval timer with mod_virt_timer */ |
| 454 | timer->interval = 0; |
| 455 | timer->expires = expires; |
| 456 | timer->cpu = cpu; |
| 457 | internal_add_vtimer(timer); |
| 458 | return 0; |
| 459 | } |
| 460 | |
| 461 | /* check if we run on the right CPU */ |
| 462 | if (timer->cpu != cpu) { |
| 463 | printk("mod_virt_timer: running on wrong CPU, check your code\n"); |
| 464 | spin_unlock_irqrestore(&vt_list->lock, flags); |
| 465 | put_cpu(); |
| 466 | return -EINVAL; |
| 467 | } |
| 468 | |
| 469 | list_del_init(&timer->entry); |
| 470 | timer->expires = expires; |
| 471 | |
| 472 | /* also change the interval if we have an interval timer */ |
| 473 | if (timer->interval) |
| 474 | timer->interval = expires; |
| 475 | |
| 476 | /* the timer can't expire anymore so we can release the lock */ |
| 477 | spin_unlock_irqrestore(&vt_list->lock, flags); |
| 478 | internal_add_vtimer(timer); |
| 479 | return 1; |
| 480 | } |
| 481 | EXPORT_SYMBOL(mod_virt_timer); |
| 482 | |
| 483 | /* |
| 484 | * delete a virtual timer |
| 485 | * |
| 486 | * returns whether the deleted timer was pending (1) or not (0) |
| 487 | */ |
| 488 | int del_virt_timer(struct vtimer_list *timer) |
| 489 | { |
| 490 | unsigned long flags; |
| 491 | struct vtimer_queue *vt_list; |
| 492 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 493 | /* check if timer is pending */ |
| 494 | if (!vtimer_pending(timer)) |
| 495 | return 0; |
| 496 | |
| 497 | vt_list = &per_cpu(virt_cpu_timer, timer->cpu); |
| 498 | spin_lock_irqsave(&vt_list->lock, flags); |
| 499 | |
| 500 | /* we don't interrupt a running timer, just let it expire! */ |
| 501 | list_del_init(&timer->entry); |
| 502 | |
| 503 | /* last timer removed */ |
| 504 | if (list_empty(&vt_list->list)) { |
| 505 | vt_list->to_expire = 0; |
| 506 | vt_list->offset = 0; |
| 507 | } |
| 508 | |
| 509 | spin_unlock_irqrestore(&vt_list->lock, flags); |
| 510 | return 1; |
| 511 | } |
| 512 | EXPORT_SYMBOL(del_virt_timer); |
| 513 | |
| 514 | /* |
| 515 | * Start the virtual CPU timer on the current CPU. |
| 516 | */ |
| 517 | void init_cpu_vtimer(void) |
| 518 | { |
| 519 | struct vtimer_queue *vt_list; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 520 | |
| 521 | /* kick the virtual timer */ |
| 522 | S390_lowcore.exit_timer = VTIMER_MAX_SLICE; |
| 523 | S390_lowcore.last_update_timer = VTIMER_MAX_SLICE; |
| 524 | asm volatile ("SPT %0" : : "m" (S390_lowcore.last_update_timer)); |
| 525 | asm volatile ("STCK %0" : "=m" (S390_lowcore.last_update_clock)); |
Martin Schwidefsky | d54853e | 2007-02-05 21:18:19 +0100 | [diff] [blame] | 526 | |
| 527 | /* enable cpu timer interrupts */ |
| 528 | __ctl_set_bit(0,10); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 529 | |
Jan Glauber | db77aa5 | 2007-04-27 16:01:55 +0200 | [diff] [blame] | 530 | vt_list = &__get_cpu_var(virt_cpu_timer); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 531 | INIT_LIST_HEAD(&vt_list->list); |
| 532 | spin_lock_init(&vt_list->lock); |
| 533 | vt_list->to_expire = 0; |
| 534 | vt_list->offset = 0; |
| 535 | vt_list->idle = 0; |
| 536 | |
| 537 | } |
| 538 | |
| 539 | static int vtimer_idle_notify(struct notifier_block *self, |
| 540 | unsigned long action, void *hcpu) |
| 541 | { |
| 542 | switch (action) { |
Heiko Carstens | dce5547 | 2007-07-10 11:24:21 +0200 | [diff] [blame] | 543 | case S390_CPU_IDLE: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 544 | stop_cpu_timer(); |
| 545 | break; |
Heiko Carstens | dce5547 | 2007-07-10 11:24:21 +0200 | [diff] [blame] | 546 | case S390_CPU_NOT_IDLE: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 547 | start_cpu_timer(); |
| 548 | break; |
| 549 | } |
| 550 | return NOTIFY_OK; |
| 551 | } |
| 552 | |
| 553 | static struct notifier_block vtimer_idle_nb = { |
| 554 | .notifier_call = vtimer_idle_notify, |
| 555 | }; |
| 556 | |
| 557 | void __init vtime_init(void) |
| 558 | { |
| 559 | /* request the cpu timer external interrupt */ |
| 560 | if (register_early_external_interrupt(0x1005, do_cpu_timer_interrupt, |
| 561 | &ext_int_info_timer) != 0) |
| 562 | panic("Couldn't request external interrupt 0x1005"); |
| 563 | |
| 564 | if (register_idle_notifier(&vtimer_idle_nb)) |
| 565 | panic("Couldn't register idle notifier"); |
| 566 | |
Martin Schwidefsky | d54853e | 2007-02-05 21:18:19 +0100 | [diff] [blame] | 567 | /* Enable cpu timer interrupts on the boot cpu. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 568 | init_cpu_vtimer(); |
| 569 | } |
| 570 | |