2 * linux/arch/cris/kernel/fasttimer.c
4 * Fast timers for ETRAX100/ETRAX100LX
6 * Copyright (C) 2000-2007 Axis Communications AB, Lund, Sweden
9 #include <linux/errno.h>
10 #include <linux/sched.h>
11 #include <linux/kernel.h>
12 #include <linux/param.h>
13 #include <linux/string.h>
15 #include <linux/vmalloc.h>
16 #include <linux/interrupt.h>
17 #include <linux/time.h>
18 #include <linux/delay.h>
20 #include <asm/segment.h>
23 #include <asm/delay.h>
27 #include <asm/arch/svinto.h>
28 #include <asm/fasttimer.h>
29 #include <linux/proc_fs.h>
32 #define DEBUG_LOG_INCLUDED
33 #define FAST_TIMER_LOG
34 /* #define FAST_TIMER_TEST */
36 #define FAST_TIMER_SANITY_CHECKS
38 #ifdef FAST_TIMER_SANITY_CHECKS
39 static int sanity_failed;
46 static unsigned int fast_timer_running;
47 static unsigned int fast_timers_added;
48 static unsigned int fast_timers_started;
49 static unsigned int fast_timers_expired;
50 static unsigned int fast_timers_deleted;
51 static unsigned int fast_timer_is_init;
52 static unsigned int fast_timer_ints;
54 struct fast_timer *fast_timer_list = NULL;
56 #ifdef DEBUG_LOG_INCLUDED
57 #define DEBUG_LOG_MAX 128
58 static const char * debug_log_string[DEBUG_LOG_MAX];
59 static unsigned long debug_log_value[DEBUG_LOG_MAX];
60 static unsigned int debug_log_cnt;
61 static unsigned int debug_log_cnt_wrapped;
63 #define DEBUG_LOG(string, value) \
65 unsigned long log_flags; \
66 local_irq_save(log_flags); \
67 debug_log_string[debug_log_cnt] = (string); \
68 debug_log_value[debug_log_cnt] = (unsigned long)(value); \
69 if (++debug_log_cnt >= DEBUG_LOG_MAX) \
71 debug_log_cnt = debug_log_cnt % DEBUG_LOG_MAX; \
72 debug_log_cnt_wrapped = 1; \
74 local_irq_restore(log_flags); \
77 #define DEBUG_LOG(string, value)
81 /* The frequencies for index = clkselx number in R_TIMER_CTRL */
82 #define NUM_TIMER_FREQ 15
83 #define MAX_USABLE_TIMER_FREQ 7
84 #define MAX_DELAY_US 853333L
85 const unsigned long timer_freq_100[NUM_TIMER_FREQ] =
87 3, /* 0 3333 - 853333 us */
88 6, /* 1 1666 - 426666 us */
89 12, /* 2 833 - 213333 us */
90 24, /* 3 416 - 106666 us */
91 48, /* 4 208 - 53333 us */
92 96, /* 5 104 - 26666 us */
93 192, /* 6 52 - 13333 us */
94 384, /* 7 26 - 6666 us */
104 #define NUM_TIMER_STATS 16
105 #ifdef FAST_TIMER_LOG
106 struct fast_timer timer_added_log[NUM_TIMER_STATS];
107 struct fast_timer timer_started_log[NUM_TIMER_STATS];
108 struct fast_timer timer_expired_log[NUM_TIMER_STATS];
111 int timer_div_settings[NUM_TIMER_STATS];
112 int timer_freq_settings[NUM_TIMER_STATS];
113 int timer_delay_settings[NUM_TIMER_STATS];
115 /* Not true gettimeofday, only checks the jiffies (uptime) + useconds */
116 inline void do_gettimeofday_fast(struct fasttime_t *tv)
118 tv->tv_jiff = jiffies;
119 tv->tv_usec = GET_JIFFIES_USEC();
122 inline int fasttime_cmp(struct fasttime_t *t0, struct fasttime_t *t1)
124 /* Compare jiffies. Takes care of wrapping */
125 if (time_before(t0->tv_jiff, t1->tv_jiff))
127 else if (time_after(t0->tv_jiff, t1->tv_jiff))
131 if (t0->tv_usec < t1->tv_usec)
133 else if (t0->tv_usec > t1->tv_usec)
138 inline void start_timer1(unsigned long delay_us)
140 int freq_index = 0; /* This is the lowest resolution */
141 unsigned long upper_limit = MAX_DELAY_US;
144 /* Start/Restart the timer to the new shorter value */
145 /* t = 1/freq = 1/19200 = 53us
146 * T=div*t, div = T/t = delay_us*freq/1000000
148 #if 1 /* Adaptive timer settings */
149 while (delay_us < upper_limit && freq_index < MAX_USABLE_TIMER_FREQ)
152 upper_limit >>= 1; /* Divide by 2 using shift */
161 div = delay_us * timer_freq_100[freq_index]/10000;
164 /* Maybe increase timer freq? */
169 div = 0; /* This means 256, the max the timer takes */
170 /* If a longer timeout than the timer can handle is used,
171 * then we must restart it when it goes off.
175 timer_div_settings[fast_timers_started % NUM_TIMER_STATS] = div;
176 timer_freq_settings[fast_timers_started % NUM_TIMER_STATS] = freq_index;
177 timer_delay_settings[fast_timers_started % NUM_TIMER_STATS] = delay_us;
179 D1(printk(KERN_DEBUG "start_timer1 : %d us freq: %i div: %i\n",
180 delay_us, freq_index, div));
181 /* Clear timer1 irq */
182 *R_IRQ_MASK0_CLR = IO_STATE(R_IRQ_MASK0_CLR, timer1, clr);
184 /* Set timer values */
185 *R_TIMER_CTRL = r_timer_ctrl_shadow =
186 (r_timer_ctrl_shadow &
187 ~IO_MASK(R_TIMER_CTRL, timerdiv1) &
188 ~IO_MASK(R_TIMER_CTRL, tm1) &
189 ~IO_MASK(R_TIMER_CTRL, clksel1)) |
190 IO_FIELD(R_TIMER_CTRL, timerdiv1, div) |
191 IO_STATE(R_TIMER_CTRL, tm1, stop_ld) |
192 IO_FIELD(R_TIMER_CTRL, clksel1, freq_index ); /* 6=c19k2Hz */
195 *R_TIMER_CTRL = r_timer_ctrl_shadow |
196 IO_STATE(R_TIMER_CTRL, i1, clr);
199 *R_TIMER_CTRL = r_timer_ctrl_shadow =
200 (r_timer_ctrl_shadow & ~IO_MASK(R_TIMER_CTRL, tm1)) |
201 IO_STATE(R_TIMER_CTRL, tm1, run);
203 /* Enable timer1 irq */
204 *R_IRQ_MASK0_SET = IO_STATE(R_IRQ_MASK0_SET, timer1, set);
205 fast_timers_started++;
206 fast_timer_running = 1;
209 /* In version 1.4 this function takes 27 - 50 us */
210 void start_one_shot_timer(struct fast_timer *t,
211 fast_timer_function_type *function,
213 unsigned long delay_us,
217 struct fast_timer *tmp;
219 D1(printk("sft %s %d us\n", name, delay_us));
221 local_irq_save(flags);
223 do_gettimeofday_fast(&t->tv_set);
224 tmp = fast_timer_list;
226 #ifdef FAST_TIMER_SANITY_CHECKS
227 /* Check so this is not in the list already... */
228 while (tmp != NULL) {
230 printk(KERN_WARNING "timer name: %s data: "
231 "0x%08lX already in list!\n", name, data);
237 tmp = fast_timer_list;
240 t->delay_us = delay_us;
241 t->function = function;
245 t->tv_expires.tv_usec = t->tv_set.tv_usec + delay_us % 1000000;
246 t->tv_expires.tv_jiff = t->tv_set.tv_jiff + delay_us / 1000000 / HZ;
247 if (t->tv_expires.tv_usec > 1000000)
249 t->tv_expires.tv_usec -= 1000000;
250 t->tv_expires.tv_jiff += HZ;
252 #ifdef FAST_TIMER_LOG
253 timer_added_log[fast_timers_added % NUM_TIMER_STATS] = *t;
257 /* Check if this should timeout before anything else */
258 if (tmp == NULL || fasttime_cmp(&t->tv_expires, &tmp->tv_expires) < 0)
260 /* Put first in list and modify the timer value */
262 t->next = fast_timer_list;
265 fast_timer_list->prev = t;
268 #ifdef FAST_TIMER_LOG
269 timer_started_log[fast_timers_started % NUM_TIMER_STATS] = *t;
271 start_timer1(delay_us);
273 /* Put in correct place in list */
274 while (tmp->next && fasttime_cmp(&t->tv_expires,
275 &tmp->next->tv_expires) > 0)
279 /* Insert t after tmp */
289 D2(printk("start_one_shot_timer: %d us done\n", delay_us));
292 local_irq_restore(flags);
293 } /* start_one_shot_timer */
295 static inline int fast_timer_pending (const struct fast_timer * t)
297 return (t->next != NULL) || (t->prev != NULL) || (t == fast_timer_list);
300 static inline int detach_fast_timer (struct fast_timer *t)
302 struct fast_timer *next, *prev;
303 if (!fast_timer_pending(t))
312 fast_timer_list = next;
313 fast_timers_deleted++;
317 int del_fast_timer(struct fast_timer * t)
322 local_irq_save(flags);
323 ret = detach_fast_timer(t);
324 t->next = t->prev = NULL;
325 local_irq_restore(flags);
327 } /* del_fast_timer */
330 /* Interrupt routines or functions called in interrupt context */
332 /* Timer 1 interrupt handler */
335 timer1_handler(int irq, void *dev_id)
337 struct fast_timer *t;
340 /* We keep interrupts disabled not only when we modify the
341 * fast timer list, but any time we hold a reference to a
342 * timer in the list, since del_fast_timer may be called
343 * from (another) interrupt context. Thus, the only time
344 * when interrupts are enabled is when calling the timer
347 local_irq_save(flags);
349 /* Clear timer1 irq */
350 *R_IRQ_MASK0_CLR = IO_STATE(R_IRQ_MASK0_CLR, timer1, clr);
352 /* First stop timer, then ack interrupt */
354 *R_TIMER_CTRL = r_timer_ctrl_shadow =
355 (r_timer_ctrl_shadow & ~IO_MASK(R_TIMER_CTRL, tm1)) |
356 IO_STATE(R_TIMER_CTRL, tm1, stop_ld);
359 *R_TIMER_CTRL = r_timer_ctrl_shadow | IO_STATE(R_TIMER_CTRL, i1, clr);
361 fast_timer_running = 0;
367 struct fasttime_t tv;
368 fast_timer_function_type *f;
371 /* Has it really expired? */
372 do_gettimeofday_fast(&tv);
373 D1(printk(KERN_DEBUG "t: %is %06ius\n",
374 tv.tv_jiff, tv.tv_usec));
376 if (fasttime_cmp(&t->tv_expires, &tv) <= 0)
378 /* Yes it has expired */
379 #ifdef FAST_TIMER_LOG
380 timer_expired_log[fast_timers_expired % NUM_TIMER_STATS] = *t;
382 fast_timers_expired++;
384 /* Remove this timer before call, since it may reuse the timer */
387 t->prev->next = t->next;
391 fast_timer_list = t->next;
395 t->next->prev = t->prev;
400 /* Save function callback data before enabling
401 * interrupts, since the timer may be removed and
402 * we don't know how it was allocated
403 * (e.g. ->function and ->data may become overwritten
404 * after deletion if the timer was stack-allocated).
410 /* Run callback with interrupts enabled. */
411 local_irq_restore(flags);
413 local_irq_save(flags);
415 DEBUG_LOG("!timer1 %i function==NULL!\n", fast_timer_ints);
419 /* Timer is to early, let's set it again using the normal routines */
423 if ((t = fast_timer_list) != NULL)
425 /* Start next timer.. */
427 struct fasttime_t tv;
429 do_gettimeofday_fast(&tv);
431 /* time_after_eq takes care of wrapping */
432 if (time_after_eq(t->tv_expires.tv_jiff, tv.tv_jiff))
433 us = ((t->tv_expires.tv_jiff - tv.tv_jiff) *
434 1000000 / HZ + t->tv_expires.tv_usec -
439 if (!fast_timer_running)
441 #ifdef FAST_TIMER_LOG
442 timer_started_log[fast_timers_started % NUM_TIMER_STATS] = *t;
450 /* Timer already expired, let's handle it better late than never.
451 * The normal loop handles it
453 D1(printk("e! %d\n", us));
458 local_irq_restore(flags);
462 D1(printk("t1 stop!\n"));
468 static void wake_up_func(unsigned long data)
470 #ifdef DECLARE_WAITQUEUE
471 wait_queue_head_t *sleep_wait_p = (wait_queue_head_t*)data;
473 struct wait_queue **sleep_wait_p = (struct wait_queue **)data;
475 wake_up(sleep_wait_p);
481 void schedule_usleep(unsigned long us)
484 wait_queue_head_t sleep_wait;
485 init_waitqueue_head(&sleep_wait);
487 D1(printk("schedule_usleep(%d)\n", us));
488 start_one_shot_timer(&t, wake_up_func, (unsigned long)&sleep_wait, us,
490 /* Uninterruptible sleep on the fast timer. (The condition is somewhat
491 * redundant since the timer is what wakes us up.) */
492 wait_event(sleep_wait, !fast_timer_pending(&t));
494 D1(printk("done schedule_usleep(%d)\n", us));
497 #ifdef CONFIG_PROC_FS
498 static int proc_fasttimer_read(char *buf, char **start, off_t offset, int len
499 ,int *eof, void *data_unused);
500 static struct proc_dir_entry *fasttimer_proc_entry;
501 #endif /* CONFIG_PROC_FS */
503 #ifdef CONFIG_PROC_FS
505 /* This value is very much based on testing */
506 #define BIG_BUF_SIZE (500 + NUM_TIMER_STATS * 300)
508 static int proc_fasttimer_read(char *buf, char **start, off_t offset, int len
509 ,int *eof, void *data_unused)
514 struct fasttime_t tv;
515 struct fast_timer *t, *nextt;
516 static char *bigbuf = NULL;
517 static unsigned long used;
519 if (!bigbuf && !(bigbuf = vmalloc(BIG_BUF_SIZE)))
527 if (!offset || !used)
529 do_gettimeofday_fast(&tv);
532 used += sprintf(bigbuf + used, "Fast timers added: %i\n",
534 used += sprintf(bigbuf + used, "Fast timers started: %i\n",
535 fast_timers_started);
536 used += sprintf(bigbuf + used, "Fast timer interrupts: %i\n",
538 used += sprintf(bigbuf + used, "Fast timers expired: %i\n",
539 fast_timers_expired);
540 used += sprintf(bigbuf + used, "Fast timers deleted: %i\n",
541 fast_timers_deleted);
542 used += sprintf(bigbuf + used, "Fast timer running: %s\n",
543 fast_timer_running ? "yes" : "no");
544 used += sprintf(bigbuf + used, "Current time: %lu.%06lu\n",
545 (unsigned long)tv.tv_jiff,
546 (unsigned long)tv.tv_usec);
547 #ifdef FAST_TIMER_SANITY_CHECKS
548 used += sprintf(bigbuf + used, "Sanity failed: %i\n",
551 used += sprintf(bigbuf + used, "\n");
553 #ifdef DEBUG_LOG_INCLUDED
555 int end_i = debug_log_cnt;
558 if (debug_log_cnt_wrapped)
563 while ((i != end_i || (debug_log_cnt_wrapped && !used)) &&
564 used+100 < BIG_BUF_SIZE)
566 used += sprintf(bigbuf + used, debug_log_string[i],
568 i = (i+1) % DEBUG_LOG_MAX;
571 used += sprintf(bigbuf + used, "\n");
574 num_to_show = (fast_timers_started < NUM_TIMER_STATS ? fast_timers_started:
576 used += sprintf(bigbuf + used, "Timers started: %i\n", fast_timers_started);
577 for (i = 0; i < num_to_show && (used+100 < BIG_BUF_SIZE) ; i++)
579 int cur = (fast_timers_started - i - 1) % NUM_TIMER_STATS;
581 #if 1 //ndef FAST_TIMER_LOG
582 used += sprintf(bigbuf + used, "div: %i freq: %i delay: %i"
584 timer_div_settings[cur],
585 timer_freq_settings[cur],
586 timer_delay_settings[cur]
589 #ifdef FAST_TIMER_LOG
590 t = &timer_started_log[cur];
591 used += sprintf(bigbuf + used, "%-14s s: %6lu.%06lu e: %6lu.%06lu "
592 "d: %6li us data: 0x%08lX"
595 (unsigned long)t->tv_set.tv_jiff,
596 (unsigned long)t->tv_set.tv_usec,
597 (unsigned long)t->tv_expires.tv_jiff,
598 (unsigned long)t->tv_expires.tv_usec,
604 used += sprintf(bigbuf + used, "\n");
606 #ifdef FAST_TIMER_LOG
607 num_to_show = (fast_timers_added < NUM_TIMER_STATS ? fast_timers_added:
609 used += sprintf(bigbuf + used, "Timers added: %i\n", fast_timers_added);
610 for (i = 0; i < num_to_show && (used+100 < BIG_BUF_SIZE); i++)
612 t = &timer_added_log[(fast_timers_added - i - 1) % NUM_TIMER_STATS];
613 used += sprintf(bigbuf + used, "%-14s s: %6lu.%06lu e: %6lu.%06lu "
614 "d: %6li us data: 0x%08lX"
617 (unsigned long)t->tv_set.tv_jiff,
618 (unsigned long)t->tv_set.tv_usec,
619 (unsigned long)t->tv_expires.tv_jiff,
620 (unsigned long)t->tv_expires.tv_usec,
625 used += sprintf(bigbuf + used, "\n");
627 num_to_show = (fast_timers_expired < NUM_TIMER_STATS ? fast_timers_expired:
629 used += sprintf(bigbuf + used, "Timers expired: %i\n", fast_timers_expired);
630 for (i = 0; i < num_to_show && (used+100 < BIG_BUF_SIZE); i++)
632 t = &timer_expired_log[(fast_timers_expired - i - 1) % NUM_TIMER_STATS];
633 used += sprintf(bigbuf + used, "%-14s s: %6lu.%06lu e: %6lu.%06lu "
634 "d: %6li us data: 0x%08lX"
637 (unsigned long)t->tv_set.tv_jiff,
638 (unsigned long)t->tv_set.tv_usec,
639 (unsigned long)t->tv_expires.tv_jiff,
640 (unsigned long)t->tv_expires.tv_usec,
645 used += sprintf(bigbuf + used, "\n");
648 used += sprintf(bigbuf + used, "Active timers:\n");
649 local_irq_save(flags);
651 while (t != NULL && (used+100 < BIG_BUF_SIZE))
654 local_irq_restore(flags);
655 used += sprintf(bigbuf + used, "%-14s s: %6lu.%06lu e: %6lu.%06lu "
656 "d: %6li us data: 0x%08lX"
657 /* " func: 0x%08lX" */
660 (unsigned long)t->tv_set.tv_jiff,
661 (unsigned long)t->tv_set.tv_usec,
662 (unsigned long)t->tv_expires.tv_jiff,
663 (unsigned long)t->tv_expires.tv_usec,
668 local_irq_save(flags);
669 if (t->next != nextt)
671 printk(KERN_WARNING "timer removed!\n");
675 local_irq_restore(flags);
678 if (used - offset < len)
683 memcpy(buf, bigbuf + offset, len);
691 #ifdef FAST_TIMER_TEST
692 static volatile unsigned long i = 0;
693 static volatile int num_test_timeout = 0;
694 static struct fast_timer tr[10];
695 static int exp_num[10];
697 static struct fasttime_t tv_exp[100];
699 static void test_timeout(unsigned long data)
701 do_gettimeofday_fast(&tv_exp[data]);
702 exp_num[data] = num_test_timeout;
707 static void test_timeout1(unsigned long data)
709 do_gettimeofday_fast(&tv_exp[data]);
710 exp_num[data] = num_test_timeout;
713 start_one_shot_timer(&tr[i], test_timeout1, i, 1000, "timeout1");
720 static char buf0[2000];
721 static char buf1[2000];
722 static char buf2[2000];
723 static char buf3[2000];
724 static char buf4[2000];
727 static char buf5[6000];
728 static int j_u[1000];
730 static void fast_timer_test(void)
735 struct fasttime_t tv, tv0, tv1, tv2;
737 printk("fast_timer_test() start\n");
738 do_gettimeofday_fast(&tv);
740 for (j = 0; j < 1000; j++)
742 j_u[j] = GET_JIFFIES_USEC();
744 for (j = 0; j < 100; j++)
746 do_gettimeofday_fast(&tv_exp[j]);
748 printk(KERN_DEBUG "fast_timer_test() %is %06i\n",
749 tv.tv_jiff, tv.tv_usec);
751 for (j = 0; j < 1000; j++)
753 printk("%i %i %i %i %i\n",j_u[j], j_u[j+1], j_u[j+2], j_u[j+3], j_u[j+4]);
756 for (j = 0; j < 100; j++)
758 printk(KERN_DEBUG "%i.%i %i.%i %i.%i %i.%i %i.%i\n",
759 tv_exp[j].tv_jiff, tv_exp[j].tv_usec,
760 tv_exp[j+1].tv_jiff, tv_exp[j+1].tv_usec,
761 tv_exp[j+2].tv_jiff, tv_exp[j+2].tv_usec,
762 tv_exp[j+3].tv_jiff, tv_exp[j+3].tv_usec,
763 tv_exp[j+4].tv_jiff, tv_exp[j+4].tv_usec);
766 do_gettimeofday_fast(&tv0);
767 start_one_shot_timer(&tr[i], test_timeout, i, 50000, "test0");
768 DP(proc_fasttimer_read(buf0, NULL, 0, 0, 0));
770 start_one_shot_timer(&tr[i], test_timeout, i, 70000, "test1");
771 DP(proc_fasttimer_read(buf1, NULL, 0, 0, 0));
773 start_one_shot_timer(&tr[i], test_timeout, i, 40000, "test2");
774 DP(proc_fasttimer_read(buf2, NULL, 0, 0, 0));
776 start_one_shot_timer(&tr[i], test_timeout, i, 60000, "test3");
777 DP(proc_fasttimer_read(buf3, NULL, 0, 0, 0));
779 start_one_shot_timer(&tr[i], test_timeout1, i, 55000, "test4xx");
780 DP(proc_fasttimer_read(buf4, NULL, 0, 0, 0));
782 do_gettimeofday_fast(&tv1);
784 proc_fasttimer_read(buf5, NULL, 0, 0, 0);
786 prev_num = num_test_timeout;
787 while (num_test_timeout < i)
789 if (num_test_timeout != prev_num)
791 prev_num = num_test_timeout;
794 do_gettimeofday_fast(&tv2);
795 printk(KERN_DEBUG "Timers started %is %06i\n",
796 tv0.tv_jiff, tv0.tv_usec);
797 printk(KERN_DEBUG "Timers started at %is %06i\n",
798 tv1.tv_jiff, tv1.tv_usec);
799 printk(KERN_DEBUG "Timers done %is %06i\n",
800 tv2.tv_jiff, tv2.tv_usec);
801 DP(printk("buf0:\n");
815 printk("timers set:\n");
818 struct fast_timer *t = &tr[j];
819 printk("%-10s set: %6is %06ius exp: %6is %06ius "
820 "data: 0x%08X func: 0x%08X\n",
824 t->tv_expires.tv_jiff,
825 t->tv_expires.tv_usec,
830 printk(" del: %6ius did exp: %6is %06ius as #%i error: %6li\n",
835 (tv_exp[j].tv_jiff - t->tv_expires.tv_jiff) *
836 1000000 + tv_exp[j].tv_usec -
837 t->tv_expires.tv_usec);
839 proc_fasttimer_read(buf5, NULL, 0, 0, 0);
840 printk("buf5 after all done:\n");
842 printk("fast_timer_test() done\n");
847 int fast_timer_init(void)
849 /* For some reason, request_irq() hangs when called froom time_init() */
850 if (!fast_timer_is_init)
852 #if 0 && defined(FAST_TIMER_TEST)
856 printk(KERN_INFO "fast_timer_init()\n");
858 #if 0 && defined(FAST_TIMER_TEST)
859 for (i = 0; i <= TIMER0_DIV; i++)
861 /* We must be careful not to get overflow... */
862 printk("%3i %6u\n", i, timer0_value_us[i]);
865 #ifdef CONFIG_PROC_FS
866 if ((fasttimer_proc_entry = create_proc_entry( "fasttimer", 0, 0 )))
867 fasttimer_proc_entry->read_proc = proc_fasttimer_read;
869 if(request_irq(TIMER1_IRQ_NBR, timer1_handler, 0,
870 "fast timer int", NULL))
872 printk("err: timer1 irq\n");
874 fast_timer_is_init = 1;
875 #ifdef FAST_TIMER_TEST
882 __initcall(fast_timer_init);