1#ifndef QEMU_TIMER_H
2#define QEMU_TIMER_H
3
4#include "qemu/typedefs.h"
5#include "qemu-common.h"
6#include "qemu/notify.h"
7
8/* timers */
9
10#define SCALE_MS 1000000
11#define SCALE_US 1000
12#define SCALE_NS 1
13
14/**
15 * QEMUClockType:
16 *
17 * The following clock types are available:
18 *
19 * @QEMU_CLOCK_REALTIME: Real time clock
20 *
21 * The real time clock should be used only for stuff which does not
22 * change the virtual machine state, as it is run even if the virtual
23 * machine is stopped. The real time clock has a frequency of 1000
24 * Hz.
25 *
26 * @QEMU_CLOCK_VIRTUAL: virtual clock
27 *
28 * The virtual clock is only run during the emulation. It is stopped
29 * when the virtual machine is stopped. Virtual timers use a high
30 * precision clock, usually cpu cycles (use ticks_per_sec).
31 *
32 * @QEMU_CLOCK_HOST: host clock
33 *
34 * The host clock should be use for device models that emulate accurate
35 * real time sources. It will continue to run when the virtual machine
36 * is suspended, and it will reflect system time changes the host may
37 * undergo (e.g. due to NTP). The host clock has the same precision as
38 * the virtual clock.
39 */
40
41typedef enum {
42    QEMU_CLOCK_REALTIME = 0,
43    QEMU_CLOCK_VIRTUAL = 1,
44    QEMU_CLOCK_HOST = 2,
45    QEMU_CLOCK_MAX
46} QEMUClockType;
47
48typedef struct QEMUTimerList QEMUTimerList;
49
50struct QEMUTimerListGroup {
51    QEMUTimerList *tl[QEMU_CLOCK_MAX];
52};
53
54typedef void QEMUTimerCB(void *opaque);
55typedef void QEMUTimerListNotifyCB(void *opaque);
56
57struct QEMUTimer {
58    int64_t expire_time;        /* in nanoseconds */
59    QEMUTimerList *timer_list;
60    QEMUTimerCB *cb;
61    void *opaque;
62    QEMUTimer *next;
63    int scale;
64};
65
66extern QEMUTimerListGroup main_loop_tlg;
67
68/*
69 * QEMUClockType
70 */
71
72/*
73 * qemu_clock_get_ns;
74 * @type: the clock type
75 *
76 * Get the nanosecond value of a clock with
77 * type @type
78 *
79 * Returns: the clock value in nanoseconds
80 */
81int64_t qemu_clock_get_ns(QEMUClockType type);
82
83/**
84 * qemu_clock_get_ms;
85 * @type: the clock type
86 *
87 * Get the millisecond value of a clock with
88 * type @type
89 *
90 * Returns: the clock value in milliseconds
91 */
92static inline int64_t qemu_clock_get_ms(QEMUClockType type)
93{
94    return qemu_clock_get_ns(type) / SCALE_MS;
95}
96
97/**
98 * qemu_clock_get_us;
99 * @type: the clock type
100 *
101 * Get the microsecond value of a clock with
102 * type @type
103 *
104 * Returns: the clock value in microseconds
105 */
106static inline int64_t qemu_clock_get_us(QEMUClockType type)
107{
108    return qemu_clock_get_ns(type) / SCALE_US;
109}
110
111/**
112 * qemu_clock_has_timers:
113 * @type: the clock type
114 *
115 * Determines whether a clock's default timer list
116 * has timers attached
117 *
118 * Note that this function should not be used when other threads also access
119 * the timer list.  The return value may be outdated by the time it is acted
120 * upon.
121 *
122 * Returns: true if the clock's default timer list
123 * has timers attached
124 */
125bool qemu_clock_has_timers(QEMUClockType type);
126
127/**
128 * qemu_clock_expired:
129 * @type: the clock type
130 *
131 * Determines whether a clock's default timer list
132 * has an expired clock.
133 *
134 * Returns: true if the clock's default timer list has
135 * an expired timer
136 */
137bool qemu_clock_expired(QEMUClockType type);
138
139/**
140 * qemu_clock_use_for_deadline:
141 * @type: the clock type
142 *
143 * Determine whether a clock should be used for deadline
144 * calculations. Some clocks, for instance vm_clock with
145 * use_icount set, do not count in nanoseconds. Such clocks
146 * are not used for deadline calculations, and are presumed
147 * to interrupt any poll using qemu_notify/aio_notify
148 * etc.
149 *
150 * Returns: true if the clock runs in nanoseconds and
151 * should be used for a deadline.
152 */
153bool qemu_clock_use_for_deadline(QEMUClockType type);
154
155/**
156 * qemu_clock_deadline_ns_all:
157 * @type: the clock type
158 *
159 * Calculate the deadline across all timer lists associated
160 * with a clock (as opposed to just the default one)
161 * in nanoseconds, or -1 if no timer is set to expire.
162 *
163 * Returns: time until expiry in nanoseconds or -1
164 */
165int64_t qemu_clock_deadline_ns_all(QEMUClockType type);
166
167/**
168 * qemu_clock_get_main_loop_timerlist:
169 * @type: the clock type
170 *
171 * Return the default timer list assocatiated with a clock.
172 *
173 * Returns: the default timer list
174 */
175QEMUTimerList *qemu_clock_get_main_loop_timerlist(QEMUClockType type);
176
177/**
178 * qemu_clock_nofify:
179 * @type: the clock type
180 *
181 * Call the notifier callback connected with the default timer
182 * list linked to the clock, or qemu_notify() if none.
183 */
184void qemu_clock_notify(QEMUClockType type);
185
186/**
187 * qemu_clock_enable:
188 * @type: the clock type
189 * @enabled: true to enable, false to disable
190 *
191 * Enable or disable a clock
192 * Disabling the clock will wait for related timerlists to stop
193 * executing qemu_run_timers.  Thus, this functions should not
194 * be used from the callback of a timer that is based on @clock.
195 * Doing so would cause a deadlock.
196 *
197 * Caller should hold BQL.
198 */
199void qemu_clock_enable(QEMUClockType type, bool enabled);
200
201/**
202 * qemu_clock_warp:
203 * @type: the clock type
204 *
205 * Warp a clock to a new value
206 */
207void qemu_clock_warp(QEMUClockType type);
208
209/**
210 * qemu_clock_register_reset_notifier:
211 * @type: the clock type
212 * @notifier: the notifier function
213 *
214 * Register a notifier function to call when the clock
215 * concerned is reset.
216 */
217void qemu_clock_register_reset_notifier(QEMUClockType type,
218                                        Notifier *notifier);
219
220/**
221 * qemu_clock_unregister_reset_notifier:
222 * @type: the clock type
223 * @notifier: the notifier function
224 *
225 * Unregister a notifier function to call when the clock
226 * concerned is reset.
227 */
228void qemu_clock_unregister_reset_notifier(QEMUClockType type,
229                                          Notifier *notifier);
230
231/**
232 * qemu_clock_run_timers:
233 * @type: clock on which to operate
234 *
235 * Run all the timers associated with the default timer list
236 * of a clock.
237 *
238 * Returns: true if any timer ran.
239 */
240bool qemu_clock_run_timers(QEMUClockType type);
241
242/**
243 * qemu_clock_run_all_timers:
244 *
245 * Run all the timers associated with the default timer list
246 * of every clock.
247 *
248 * Returns: true if any timer ran.
249 */
250bool qemu_clock_run_all_timers(void);
251
252/*
253 * QEMUTimerList
254 */
255
256/**
257 * timerlist_new:
258 * @type: the clock type to associate with the timerlist
259 * @cb: the callback to call on notification
260 * @opaque: the opaque pointer to pass to the callback
261 *
262 * Create a new timerlist associated with the clock of
263 * type @type.
264 *
265 * Returns: a pointer to the QEMUTimerList created
266 */
267QEMUTimerList *timerlist_new(QEMUClockType type,
268                             QEMUTimerListNotifyCB *cb, void *opaque);
269
270/**
271 * timerlist_free:
272 * @timer_list: the timer list to free
273 *
274 * Frees a timer_list. It must have no active timers.
275 */
276void timerlist_free(QEMUTimerList *timer_list);
277
278/**
279 * timerlist_has_timers:
280 * @timer_list: the timer list to operate on
281 *
282 * Determine whether a timer list has active timers
283 *
284 * Note that this function should not be used when other threads also access
285 * the timer list.  The return value may be outdated by the time it is acted
286 * upon.
287 *
288 * Returns: true if the timer list has timers.
289 */
290bool timerlist_has_timers(QEMUTimerList *timer_list);
291
292/**
293 * timerlist_expired:
294 * @timer_list: the timer list to operate on
295 *
296 * Determine whether a timer list has any timers which
297 * are expired.
298 *
299 * Returns: true if the timer list has timers which
300 * have expired.
301 */
302bool timerlist_expired(QEMUTimerList *timer_list);
303
304/**
305 * timerlist_deadline_ns:
306 * @timer_list: the timer list to operate on
307 *
308 * Determine the deadline for a timer_list, i.e.
309 * the number of nanoseconds until the first timer
310 * expires. Return -1 if there are no timers.
311 *
312 * Returns: the number of nanoseconds until the earliest
313 * timer expires -1 if none
314 */
315int64_t timerlist_deadline_ns(QEMUTimerList *timer_list);
316
317/**
318 * timerlist_get_clock:
319 * @timer_list: the timer list to operate on
320 *
321 * Determine the clock type associated with a timer list.
322 *
323 * Returns: the clock type associated with the
324 * timer list.
325 */
326QEMUClockType timerlist_get_clock(QEMUTimerList *timer_list);
327
328/**
329 * timerlist_run_timers:
330 * @timer_list: the timer list to use
331 *
332 * Call all expired timers associated with the timer list.
333 *
334 * Returns: true if any timer expired
335 */
336bool timerlist_run_timers(QEMUTimerList *timer_list);
337
338/**
339 * timerlist_notify:
340 * @timer_list: the timer list to use
341 *
342 * call the notifier callback associated with the timer list.
343 */
344void timerlist_notify(QEMUTimerList *timer_list);
345
346/*
347 * QEMUTimerListGroup
348 */
349
350/**
351 * timerlistgroup_init:
352 * @tlg: the timer list group
353 * @cb: the callback to call when a notify is required
354 * @opaque: the opaque pointer to be passed to the callback.
355 *
356 * Initialise a timer list group. This must already be
357 * allocated in memory and zeroed. The notifier callback is
358 * called whenever a clock in the timer list group is
359 * reenabled or whenever a timer associated with any timer
360 * list is modified. If @cb is specified as null, qemu_notify()
361 * is used instead.
362 */
363void timerlistgroup_init(QEMUTimerListGroup *tlg,
364                         QEMUTimerListNotifyCB *cb, void *opaque);
365
366/**
367 * timerlistgroup_deinit:
368 * @tlg: the timer list group
369 *
370 * Deinitialise a timer list group. This must already be
371 * initialised. Note the memory is not freed.
372 */
373void timerlistgroup_deinit(QEMUTimerListGroup *tlg);
374
375/**
376 * timerlistgroup_run_timers:
377 * @tlg: the timer list group
378 *
379 * Run the timers associated with a timer list group.
380 * This will run timers on multiple clocks.
381 *
382 * Returns: true if any timer callback ran
383 */
384bool timerlistgroup_run_timers(QEMUTimerListGroup *tlg);
385
386/**
387 * timerlistgroup_deadline_ns:
388 * @tlg: the timer list group
389 *
390 * Determine the deadline of the soonest timer to
391 * expire associated with any timer list linked to
392 * the timer list group. Only clocks suitable for
393 * deadline calculation are included.
394 *
395 * Returns: the deadline in nanoseconds or -1 if no
396 * timers are to expire.
397 */
398int64_t timerlistgroup_deadline_ns(QEMUTimerListGroup *tlg);
399
400/*
401 * QEMUTimer
402 */
403
404/**
405 * timer_init:
406 * @ts: the timer to be initialised
407 * @timer_list: the timer list to attach the timer to
408 * @scale: the scale value for the tiemr
409 * @cb: the callback to be called when the timer expires
410 * @opaque: the opaque pointer to be passed to the callback
411 *
412 * Initialise a new timer and associate it with @timer_list.
413 * The caller is responsible for allocating the memory.
414 *
415 * You need not call an explicit deinit call. Simply make
416 * sure it is not on a list with timer_del.
417 */
418void timer_init(QEMUTimer *ts,
419                QEMUTimerList *timer_list, int scale,
420                QEMUTimerCB *cb, void *opaque);
421
422/**
423 * timer_new_tl:
424 * @timer_list: the timer list to attach the timer to
425 * @scale: the scale value for the tiemr
426 * @cb: the callback to be called when the timer expires
427 * @opaque: the opaque pointer to be passed to the callback
428 *
429 * Creeate a new timer and associate it with @timer_list.
430 * The memory is allocated by the function.
431 *
432 * This is not the preferred interface unless you know you
433 * are going to call timer_free. Use timer_init instead.
434 *
435 * Returns: a pointer to the timer
436 */
437static inline QEMUTimer *timer_new_tl(QEMUTimerList *timer_list,
438                                      int scale,
439                                      QEMUTimerCB *cb,
440                                      void *opaque)
441{
442    QEMUTimer *ts = g_malloc0(sizeof(QEMUTimer));
443    timer_init(ts, timer_list, scale, cb, opaque);
444    return ts;
445}
446
447/**
448 * timer_new:
449 * @type: the clock type to use
450 * @scale: the scale value for the tiemr
451 * @cb: the callback to be called when the timer expires
452 * @opaque: the opaque pointer to be passed to the callback
453 *
454 * Creeate a new timer and associate it with the default
455 * timer list for the clock type @type.
456 *
457 * Returns: a pointer to the timer
458 */
459static inline QEMUTimer *timer_new(QEMUClockType type, int scale,
460                                   QEMUTimerCB *cb, void *opaque)
461{
462    return timer_new_tl(main_loop_tlg.tl[type], scale, cb, opaque);
463}
464
465/**
466 * timer_new_ns:
467 * @clock: the clock to associate with the timer
468 * @callback: the callback to call when the timer expires
469 * @opaque: the opaque pointer to pass to the callback
470 *
471 * Create a new timer with nanosecond scale on the default timer list
472 * associated with the clock.
473 *
474 * Returns: a pointer to the newly created timer
475 */
476static inline QEMUTimer *timer_new_ns(QEMUClockType type, QEMUTimerCB *cb,
477                                      void *opaque)
478{
479    return timer_new(type, SCALE_NS, cb, opaque);
480}
481
482/**
483 * timer_new_us:
484 * @clock: the clock to associate with the timer
485 * @callback: the callback to call when the timer expires
486 * @opaque: the opaque pointer to pass to the callback
487 *
488 * Create a new timer with microsecond scale on the default timer list
489 * associated with the clock.
490 *
491 * Returns: a pointer to the newly created timer
492 */
493static inline QEMUTimer *timer_new_us(QEMUClockType type, QEMUTimerCB *cb,
494                                      void *opaque)
495{
496    return timer_new(type, SCALE_US, cb, opaque);
497}
498
499/**
500 * timer_new_ms:
501 * @clock: the clock to associate with the timer
502 * @callback: the callback to call when the timer expires
503 * @opaque: the opaque pointer to pass to the callback
504 *
505 * Create a new timer with millisecond scale on the default timer list
506 * associated with the clock.
507 *
508 * Returns: a pointer to the newly created timer
509 */
510static inline QEMUTimer *timer_new_ms(QEMUClockType type, QEMUTimerCB *cb,
511                                      void *opaque)
512{
513    return timer_new(type, SCALE_MS, cb, opaque);
514}
515
516/**
517 * timer_free:
518 * @ts: the timer
519 *
520 * Free a timer (it must not be on the active list)
521 */
522void timer_free(QEMUTimer *ts);
523
524/**
525 * timer_del:
526 * @ts: the timer
527 *
528 * Delete a timer from the active list.
529 *
530 * This function is thread-safe but the timer and its timer list must not be
531 * freed while this function is running.
532 */
533void timer_del(QEMUTimer *ts);
534
535/**
536 * timer_mod_ns:
537 * @ts: the timer
538 * @expire_time: the expiry time in nanoseconds
539 *
540 * Modify a timer to expire at @expire_time
541 *
542 * This function is thread-safe but the timer and its timer list must not be
543 * freed while this function is running.
544 */
545void timer_mod_ns(QEMUTimer *ts, int64_t expire_time);
546
547/**
548 * timer_mod_anticipate_ns:
549 * @ts: the timer
550 * @expire_time: the expiry time in nanoseconds
551 *
552 * Modify a timer to expire at @expire_time or the current time,
553 * whichever comes earlier.
554 *
555 * This function is thread-safe but the timer and its timer list must not be
556 * freed while this function is running.
557 */
558void timer_mod_anticipate_ns(QEMUTimer *ts, int64_t expire_time);
559
560/**
561 * timer_mod:
562 * @ts: the timer
563 * @expire_time: the expire time in the units associated with the timer
564 *
565 * Modify a timer to expiry at @expire_time, taking into
566 * account the scale associated with the timer.
567 *
568 * This function is thread-safe but the timer and its timer list must not be
569 * freed while this function is running.
570 */
571void timer_mod(QEMUTimer *ts, int64_t expire_timer);
572
573/**
574 * timer_mod_anticipate:
575 * @ts: the timer
576 * @expire_time: the expiry time in nanoseconds
577 *
578 * Modify a timer to expire at @expire_time or the current time, whichever
579 * comes earlier, taking into account the scale associated with the timer.
580 *
581 * This function is thread-safe but the timer and its timer list must not be
582 * freed while this function is running.
583 */
584void timer_mod_anticipate(QEMUTimer *ts, int64_t expire_time);
585
586/**
587 * timer_pending:
588 * @ts: the timer
589 *
590 * Determines whether a timer is pending (i.e. is on the
591 * active list of timers, whether or not it has not yet expired).
592 *
593 * Returns: true if the timer is pending
594 */
595bool timer_pending(QEMUTimer *ts);
596
597/**
598 * timer_expired:
599 * @ts: the timer
600 *
601 * Determines whether a timer has expired.
602 *
603 * Returns: true if the timer has expired
604 */
605bool timer_expired(QEMUTimer *timer_head, int64_t current_time);
606
607/**
608 * timer_expire_time_ns:
609 * @ts: the timer
610 *
611 * Determine the expiry time of a timer
612 *
613 * Returns: the expiry time in nanoseconds
614 */
615uint64_t timer_expire_time_ns(QEMUTimer *ts);
616
617/**
618 * timer_get:
619 * @f: the file
620 * @ts: the timer
621 *
622 * Read a timer @ts from a file @f
623 */
624void timer_get(QEMUFile *f, QEMUTimer *ts);
625
626/**
627 * timer_put:
628 * @f: the file
629 * @ts: the timer
630 */
631void timer_put(QEMUFile *f, QEMUTimer *ts);
632
633/*
634 * General utility functions
635 */
636
637/**
638 * qemu_timeout_ns_to_ms:
639 * @ns: nanosecond timeout value
640 *
641 * Convert a nanosecond timeout value (or -1) to
642 * a millisecond value (or -1), always rounding up.
643 *
644 * Returns: millisecond timeout value
645 */
646int qemu_timeout_ns_to_ms(int64_t ns);
647
648/**
649 * qemu_poll_ns:
650 * @fds: Array of file descriptors
651 * @nfds: number of file descriptors
652 * @timeout: timeout in nanoseconds
653 *
654 * Perform a poll like g_poll but with a timeout in nanoseconds.
655 * See g_poll documentation for further details.
656 *
657 * Returns: number of fds ready
658 */
659int qemu_poll_ns(GPollFD *fds, guint nfds, int64_t timeout);
660
661/**
662 * qemu_soonest_timeout:
663 * @timeout1: first timeout in nanoseconds (or -1 for infinite)
664 * @timeout2: second timeout in nanoseconds (or -1 for infinite)
665 *
666 * Calculates the soonest of two timeout values. -1 means infinite, which
667 * is later than any other value.
668 *
669 * Returns: soonest timeout value in nanoseconds (or -1 for infinite)
670 */
671static inline int64_t qemu_soonest_timeout(int64_t timeout1, int64_t timeout2)
672{
673    /* we can abuse the fact that -1 (which means infinite) is a maximal
674     * value when cast to unsigned. As this is disgusting, it's kept in
675     * one inline function.
676     */
677    return ((uint64_t) timeout1 < (uint64_t) timeout2) ? timeout1 : timeout2;
678}
679
680/**
681 * initclocks:
682 *
683 * Initialise the clock & timer infrastructure
684 */
685void init_clocks(void);
686
687int64_t cpu_get_ticks(void);
688/* Caller must hold BQL */
689void cpu_enable_ticks(void);
690/* Caller must hold BQL */
691void cpu_disable_ticks(void);
692
693static inline int64_t get_ticks_per_sec(void)
694{
695    return 1000000000LL;
696}
697
698/*
699 * Low level clock functions
700 */
701
702/* real time host monotonic timer */
703static inline int64_t get_clock_realtime(void)
704{
705    struct timeval tv;
706
707    gettimeofday(&tv, NULL);
708    return tv.tv_sec * 1000000000LL + (tv.tv_usec * 1000);
709}
710
711/* Warning: don't insert tracepoints into these functions, they are
712   also used by simpletrace backend and tracepoints would cause
713   an infinite recursion! */
714#ifdef _WIN32
715extern int64_t clock_freq;
716
717static inline int64_t get_clock(void)
718{
719    LARGE_INTEGER ti;
720    QueryPerformanceCounter(&ti);
721    return muldiv64(ti.QuadPart, get_ticks_per_sec(), clock_freq);
722}
723
724#else
725
726extern int use_rt_clock;
727
728static inline int64_t get_clock(void)
729{
730#ifdef CLOCK_MONOTONIC
731    if (use_rt_clock) {
732        struct timespec ts;
733        clock_gettime(CLOCK_MONOTONIC, &ts);
734        return ts.tv_sec * 1000000000LL + ts.tv_nsec;
735    } else
736#endif
737    {
738        /* XXX: using gettimeofday leads to problems if the date
739           changes, so it should be avoided. */
740        return get_clock_realtime();
741    }
742}
743#endif
744
745/* icount */
746int64_t cpu_get_icount(void);
747int64_t cpu_get_clock(void);
748
749/*******************************************/
750/* host CPU ticks (if available) */
751
752#if defined(_ARCH_PPC)
753
754static inline int64_t cpu_get_real_ticks(void)
755{
756    int64_t retval;
757#ifdef _ARCH_PPC64
758    /* This reads timebase in one 64bit go and includes Cell workaround from:
759       http://ozlabs.org/pipermail/linuxppc-dev/2006-October/027052.html
760    */
761    __asm__ __volatile__ ("mftb    %0\n\t"
762                          "cmpwi   %0,0\n\t"
763                          "beq-    $-8"
764                          : "=r" (retval));
765#else
766    /* http://ozlabs.org/pipermail/linuxppc-dev/1999-October/003889.html */
767    unsigned long junk;
768    __asm__ __volatile__ ("mfspr   %1,269\n\t"  /* mftbu */
769                          "mfspr   %L0,268\n\t" /* mftb */
770                          "mfspr   %0,269\n\t"  /* mftbu */
771                          "cmpw    %0,%1\n\t"
772                          "bne     $-16"
773                          : "=r" (retval), "=r" (junk));
774#endif
775    return retval;
776}
777
778#elif defined(__i386__)
779
780static inline int64_t cpu_get_real_ticks(void)
781{
782    int64_t val;
783    asm volatile ("rdtsc" : "=A" (val));
784    return val;
785}
786
787#elif defined(__x86_64__)
788
789static inline int64_t cpu_get_real_ticks(void)
790{
791    uint32_t low,high;
792    int64_t val;
793    asm volatile("rdtsc" : "=a" (low), "=d" (high));
794    val = high;
795    val <<= 32;
796    val |= low;
797    return val;
798}
799
800#elif defined(__hppa__)
801
802static inline int64_t cpu_get_real_ticks(void)
803{
804    int val;
805    asm volatile ("mfctl %%cr16, %0" : "=r"(val));
806    return val;
807}
808
809#elif defined(__ia64)
810
811static inline int64_t cpu_get_real_ticks(void)
812{
813    int64_t val;
814    asm volatile ("mov %0 = ar.itc" : "=r"(val) :: "memory");
815    return val;
816}
817
818#elif defined(__s390__)
819
820static inline int64_t cpu_get_real_ticks(void)
821{
822    int64_t val;
823    asm volatile("stck 0(%1)" : "=m" (val) : "a" (&val) : "cc");
824    return val;
825}
826
827#elif defined(__sparc__)
828
829static inline int64_t cpu_get_real_ticks (void)
830{
831#if defined(_LP64)
832    uint64_t        rval;
833    asm volatile("rd %%tick,%0" : "=r"(rval));
834    return rval;
835#else
836    /* We need an %o or %g register for this.  For recent enough gcc
837       there is an "h" constraint for that.  Don't bother with that.  */
838    union {
839        uint64_t i64;
840        struct {
841            uint32_t high;
842            uint32_t low;
843        }       i32;
844    } rval;
845    asm volatile("rd %%tick,%%g1; srlx %%g1,32,%0; mov %%g1,%1"
846                 : "=r"(rval.i32.high), "=r"(rval.i32.low) : : "g1");
847    return rval.i64;
848#endif
849}
850
851#elif defined(__mips__) && \
852    ((defined(__mips_isa_rev) && __mips_isa_rev >= 2) || defined(__linux__))
853/*
854 * binutils wants to use rdhwr only on mips32r2
855 * but as linux kernel emulate it, it's fine
856 * to use it.
857 *
858 */
859#define MIPS_RDHWR(rd, value) {                         \
860        __asm__ __volatile__ (".set   push\n\t"         \
861                              ".set mips32r2\n\t"       \
862                              "rdhwr  %0, "rd"\n\t"     \
863                              ".set   pop"              \
864                              : "=r" (value));          \
865    }
866
867static inline int64_t cpu_get_real_ticks(void)
868{
869    /* On kernels >= 2.6.25 rdhwr <reg>, $2 and $3 are emulated */
870    uint32_t count;
871    static uint32_t cyc_per_count = 0;
872
873    if (!cyc_per_count) {
874        MIPS_RDHWR("$3", cyc_per_count);
875    }
876
877    MIPS_RDHWR("$2", count);
878    return (int64_t)(count * cyc_per_count);
879}
880
881#elif defined(__alpha__)
882
883static inline int64_t cpu_get_real_ticks(void)
884{
885    uint64_t cc;
886    uint32_t cur, ofs;
887
888    asm volatile("rpcc %0" : "=r"(cc));
889    cur = cc;
890    ofs = cc >> 32;
891    return cur - ofs;
892}
893
894#else
895/* The host CPU doesn't have an easily accessible cycle counter.
896   Just return a monotonically increasing value.  This will be
897   totally wrong, but hopefully better than nothing.  */
898static inline int64_t cpu_get_real_ticks (void)
899{
900    static int64_t ticks = 0;
901    return ticks++;
902}
903#endif
904
905#ifdef CONFIG_PROFILER
906static inline int64_t profile_getclock(void)
907{
908    return cpu_get_real_ticks();
909}
910
911extern int64_t qemu_time, qemu_time_start;
912extern int64_t tlb_flush_time;
913extern int64_t dev_time;
914#endif
915
916#endif
917