/* * linux/arch/cris/kernel/fasttimer.c * * Fast timers for ETRAX FS * * Copyright (C) 2000-2006 Axis Communications AB, Lund, Sweden */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * timer0 is running at 100MHz and generating jiffies timer ticks * at 100 or 1000 HZ. * fasttimer gives an API that gives timers that expire "between" the jiffies * giving microsecond resolution (10 ns). * fasttimer uses reg_timer_rw_trig register to get interrupt when * r_time reaches a certain value. */ #define DEBUG_LOG_INCLUDED #define FAST_TIMER_LOG /* #define FAST_TIMER_TEST */ #define FAST_TIMER_SANITY_CHECKS #ifdef FAST_TIMER_SANITY_CHECKS static int sanity_failed; #endif #define D1(x) #define D2(x) #define DP(x) static unsigned int fast_timer_running; static unsigned int fast_timers_added; static unsigned int fast_timers_started; static unsigned int fast_timers_expired; static unsigned int fast_timers_deleted; static unsigned int fast_timer_is_init; static unsigned int fast_timer_ints; struct fast_timer *fast_timer_list = NULL; #ifdef DEBUG_LOG_INCLUDED #define DEBUG_LOG_MAX 128 static const char * debug_log_string[DEBUG_LOG_MAX]; static unsigned long debug_log_value[DEBUG_LOG_MAX]; static unsigned int debug_log_cnt; static unsigned int debug_log_cnt_wrapped; #define DEBUG_LOG(string, value) \ { \ unsigned long log_flags; \ local_irq_save(log_flags); \ debug_log_string[debug_log_cnt] = (string); \ debug_log_value[debug_log_cnt] = (unsigned long)(value); \ if (++debug_log_cnt >= DEBUG_LOG_MAX) \ { \ debug_log_cnt = debug_log_cnt % DEBUG_LOG_MAX; \ debug_log_cnt_wrapped = 1; \ } \ local_irq_restore(log_flags); \ } #else #define DEBUG_LOG(string, value) #endif #define NUM_TIMER_STATS 16 #ifdef FAST_TIMER_LOG struct fast_timer timer_added_log[NUM_TIMER_STATS]; struct fast_timer timer_started_log[NUM_TIMER_STATS]; struct fast_timer timer_expired_log[NUM_TIMER_STATS]; #endif int timer_div_settings[NUM_TIMER_STATS]; int timer_delay_settings[NUM_TIMER_STATS]; struct work_struct fast_work; static void timer_trig_handler(struct work_struct *work); /* Not true gettimeofday, only checks the jiffies (uptime) + useconds */ inline void do_gettimeofday_fast(struct fasttime_t *tv) { tv->tv_jiff = jiffies; tv->tv_usec = GET_JIFFIES_USEC(); } inline int fasttime_cmp(struct fasttime_t *t0, struct fasttime_t *t1) { /* Compare jiffies. Takes care of wrapping */ if (time_before(t0->tv_jiff, t1->tv_jiff)) return -1; else if (time_after(t0->tv_jiff, t1->tv_jiff)) return 1; /* Compare us */ if (t0->tv_usec < t1->tv_usec) return -1; else if (t0->tv_usec > t1->tv_usec) return 1; return 0; } /* Called with ints off */ inline void start_timer_trig(unsigned long delay_us) { reg_timer_rw_ack_intr ack_intr = { 0 }; reg_timer_rw_intr_mask intr_mask; reg_timer_rw_trig trig; reg_timer_rw_trig_cfg trig_cfg = { 0 }; reg_timer_r_time r_time0; reg_timer_r_time r_time1; unsigned char trig_wrap; unsigned char time_wrap; r_time0 = REG_RD(timer, regi_timer0, r_time); D1(printk("start_timer_trig : %d us freq: %i div: %i\n", delay_us, freq_index, div)); /* Clear trig irq */ intr_mask = REG_RD(timer, regi_timer0, rw_intr_mask); intr_mask.trig = 0; REG_WR(timer, regi_timer0, rw_intr_mask, intr_mask); /* Set timer values and check if trigger wraps. */ /* r_time is 100MHz (10 ns resolution) */ trig_wrap = (trig = r_time0 + delay_us*(1000/10)) < r_time0; timer_div_settings[fast_timers_started % NUM_TIMER_STATS] = trig; timer_delay_settings[fast_timers_started % NUM_TIMER_STATS] = delay_us; /* Ack interrupt */ ack_intr.trig = 1; REG_WR(timer, regi_timer0, rw_ack_intr, ack_intr); /* Start timer */ REG_WR(timer, regi_timer0, rw_trig, trig); trig_cfg.tmr = regk_timer_time; REG_WR(timer, regi_timer0, rw_trig_cfg, trig_cfg); /* Check if we have already passed the trig time */ r_time1 = REG_RD(timer, regi_timer0, r_time); time_wrap = r_time1 < r_time0; if ((trig_wrap && !time_wrap) || (r_time1 < trig)) { /* No, Enable trig irq */ intr_mask = REG_RD(timer, regi_timer0, rw_intr_mask); intr_mask.trig = 1; REG_WR(timer, regi_timer0, rw_intr_mask, intr_mask); fast_timers_started++; fast_timer_running = 1; } else { /* We have passed the time, disable trig point, ack intr */ trig_cfg.tmr = regk_timer_off; REG_WR(timer, regi_timer0, rw_trig_cfg, trig_cfg); REG_WR(timer, regi_timer0, rw_ack_intr, ack_intr); /* call the int routine */ INIT_WORK(&fast_work, timer_trig_handler); schedule_work(&fast_work); } } /* In version 1.4 this function takes 27 - 50 us */ void start_one_shot_timer(struct fast_timer *t, fast_timer_function_type *function, unsigned long data, unsigned long delay_us, const char *name) { unsigned long flags; struct fast_timer *tmp; D1(printk("sft %s %d us\n", name, delay_us)); local_irq_save(flags); do_gettimeofday_fast(&t->tv_set); tmp = fast_timer_list; #ifdef FAST_TIMER_SANITY_CHECKS /* Check so this is not in the list already... */ while (tmp != NULL) { if (tmp == t) { printk(KERN_DEBUG "timer name: %s data: 0x%08lX already " "in list!\n", name, data); sanity_failed++; goto done; } else tmp = tmp->next; } tmp = fast_timer_list; #endif t->delay_us = delay_us; t->function = function; t->data = data; t->name = name; t->tv_expires.tv_usec = t->tv_set.tv_usec + delay_us % 1000000; t->tv_expires.tv_jiff = t->tv_set.tv_jiff + delay_us / 1000000 / HZ; if (t->tv_expires.tv_usec > 1000000) { t->tv_expires.tv_usec -= 1000000; t->tv_expires.tv_jiff += HZ; } #ifdef FAST_TIMER_LOG timer_added_log[fast_timers_added % NUM_TIMER_STATS] = *t; #endif fast_timers_added++; /* Check if this should timeout before anything else */ if (tmp == NULL || fasttime_cmp(&t->tv_expires, &tmp->tv_expires) < 0) { /* Put first in list and modify the timer value */ t->prev = NULL; t->next = fast_timer_list; if (fast_timer_list) fast_timer_list->prev = t; fast_timer_list = t; #ifdef FAST_TIMER_LOG timer_started_log[fast_timers_started % NUM_TIMER_STATS] = *t; #endif start_timer_trig(delay_us); } else { /* Put in correct place in list */ while (tmp->next && fasttime_cmp(&t->tv_expires, &tmp->next->tv_expires) > 0) tmp = tmp->next; /* Insert t after tmp */ t->prev = tmp; t->next = tmp->next; if (tmp->next) { tmp->next->prev = t; } tmp->next = t; } D2(printk("start_one_shot_timer: %d us done\n", delay_us)); done: local_irq_restore(flags); } /* start_one_shot_timer */ static inline int fast_timer_pending (const struct fast_timer * t) { return (t->next != NULL) || (t->prev != NULL) || (t == fast_timer_list); } static inline int detach_fast_timer (struct fast_timer *t) { struct fast_timer *next, *prev; if (!fast_timer_pending(t)) return 0; next = t->next; prev = t->prev; if (next) next->prev = prev; if (prev) prev->next = next; else fast_timer_list = next; fast_timers_deleted++; return 1; } int del_fast_timer(struct fast_timer * t) { unsigned long flags; int ret; local_irq_save(flags); ret = detach_fast_timer(t); t->next = t->prev = NULL; local_irq_restore(flags); return ret; } /* del_fast_timer */ /* Interrupt routines or functions called in interrupt context */ /* Timer interrupt handler for trig interrupts */ static irqreturn_t timer_trig_interrupt(int irq, void *dev_id) { reg_timer_r_masked_intr masked_intr; /* Check if the timer interrupt is for us (a trig int) */ masked_intr = REG_RD(timer, regi_timer0, r_masked_intr); if (!masked_intr.trig) return IRQ_NONE; timer_trig_handler(NULL); return IRQ_HANDLED; } static void timer_trig_handler(struct work_struct *work) { reg_timer_rw_ack_intr ack_intr = { 0 }; reg_timer_rw_intr_mask intr_mask; reg_timer_rw_trig_cfg trig_cfg = { 0 }; struct fast_timer *t; unsigned long flags; /* We keep interrupts disabled not only when we modify the * fast timer list, but any time we hold a reference to a * timer in the list, since del_fast_timer may be called * from (another) interrupt context. Thus, the only time * when interrupts are enabled is when calling the timer * callback function. */ local_irq_save(flags); /* Clear timer trig interrupt */ intr_mask = REG_RD(timer, regi_timer0, rw_intr_mask); intr_mask.trig = 0; REG_WR(timer, regi_timer0, rw_intr_mask, intr_mask); /* First stop timer, then ack interrupt */ /* Stop timer */ trig_cfg.tmr = regk_timer_off; REG_WR(timer, regi_timer0, rw_trig_cfg, trig_cfg); /* Ack interrupt */ ack_intr.trig = 1; REG_WR(timer, regi_timer0, rw_ack_intr, ack_intr); fast_timer_running = 0; fast_timer_ints++; fast_timer_function_type *f; unsigned long d; t = fast_timer_list; while (t) { struct fasttime_t tv; /* Has it really expired? */ do_gettimeofday_fast(&tv); D1(printk(KERN_DEBUG "t: %is %06ius\n", tv.tv_jiff, tv.tv_usec)); if (fasttime_cmp(&t->tv_expires, &tv) <= 0) { /* Yes it has expired */ #ifdef FAST_TIMER_LOG timer_expired_log[fast_timers_expired % NUM_TIMER_STATS] = *t; #endif fast_timers_expired++; /* Remove this timer before call, since it may reuse the timer */ if (t->prev) t->prev->next = t->next; else fast_timer_list = t->next; if (t->next) t->next->prev = t->prev; t->prev = NULL; t->next = NULL; /* Save function callback data before enabling * interrupts, since the timer may be removed and we * don't know how it was allocated (e.g. ->function * and ->data may become overwritten after deletion * if the timer was stack-allocated). */ f = t->function; d = t->data; if (f != NULL) { /* Run the callback function with interrupts * enabled. */ local_irq_restore(flags); f(d); local_irq_save(flags); } else DEBUG_LOG("!trimertrig %i function==NULL!\n", fast_timer_ints); } else { /* Timer is to early, let's set it again using the normal routines */ D1(printk(".\n")); } t = fast_timer_list; if (t != NULL) { /* Start next timer.. */ long us = 0; struct fasttime_t tv; do_gettimeofday_fast(&tv); /* time_after_eq takes care of wrapping */ if (time_after_eq(t->tv_expires.tv_jiff, tv.tv_jiff)) us = ((t->tv_expires.tv_jiff - tv.tv_jiff) * 1000000 / HZ + t->tv_expires.tv_usec - tv.tv_usec); if (us > 0) { if (!fast_timer_running) { #ifdef FAST_TIMER_LOG timer_started_log[fast_timers_started % NUM_TIMER_STATS] = *t; #endif start_timer_trig(us); } break; } else { /* Timer already expired, let's handle it better late than never. * The normal loop handles it */ D1(printk("e! %d\n", us)); } } } local_irq_restore(flags); if (!t) D1(printk("ttrig stop!\n")); } static void wake_up_func(unsigned long data) { wait_queue_head_t *sleep_wait_p = (wait_queue_head_t*)data; wake_up(sleep_wait_p); } /* Useful API */ void schedule_usleep(unsigned long us) { struct fast_timer t; wait_queue_head_t sleep_wait; init_waitqueue_head(&sleep_wait); D1(printk("schedule_usleep(%d)\n", us)); start_one_shot_timer(&t, wake_up_func, (unsigned long)&sleep_wait, us, "usleep"); /* Uninterruptible sleep on the fast timer. (The condition is * somewhat redundant since the timer is what wakes us up.) */ wait_event(sleep_wait, !fast_timer_pending(&t)); D1(printk("done schedule_usleep(%d)\n", us)); } #ifdef CONFIG_PROC_FS static int proc_fasttimer_read(char *buf, char **start, off_t offset, int len ,int *eof, void *data_unused); #endif /* CONFIG_PROC_FS */ #ifdef CONFIG_PROC_FS /* This value is very much based on testing */ #define BIG_BUF_SIZE (500 + NUM_TIMER_STATS * 300) static int proc_fasttimer_read(char *buf, char **start, off_t offset, int len ,int *eof, void *data_unused) { unsigned long flags; int i = 0; int num_to_show; struct fasttime_t tv; struct fast_timer *t, *nextt; static char *bigbuf = NULL; static unsigned long used; if (!bigbuf) { bigbuf = vmalloc(BIG_BUF_SIZE); if (!bigbuf) { used = 0; if (buf) buf[0] = '\0'; return 0; } } if (!offset || !used) { do_gettimeofday_fast(&tv); used = 0; used += sprintf(bigbuf + used, "Fast timers added: %i\n", fast_timers_added); used += sprintf(bigbuf + used, "Fast timers started: %i\n", fast_timers_started); used += sprintf(bigbuf + used, "Fast timer interrupts: %i\n", fast_timer_ints); used += sprintf(bigbuf + used, "Fast timers expired: %i\n", fast_timers_expired); used += sprintf(bigbuf + used, "Fast timers deleted: %i\n", fast_timers_deleted); used += sprintf(bigbuf + used, "Fast timer running: %s\n", fast_timer_running ? "yes" : "no"); used += sprintf(bigbuf + used, "Current time: %lu.%06lu\n", (unsigned long)tv.tv_jiff, (unsigned long)tv.tv_usec); #ifdef FAST_TIMER_SANITY_CHECKS used += sprintf(bigbuf + used, "Sanity failed: %i\n", sanity_failed); #endif used += sprintf(bigbuf + used, "\n"); #ifdef DEBUG_LOG_INCLUDED { int end_i = debug_log_cnt; i = 0; if (debug_log_cnt_wrapped) i = debug_log_cnt; while ((i != end_i || (debug_log_cnt_wrapped && !used)) && used+100 < BIG_BUF_SIZE) { used += sprintf(bigbuf + used, debug_log_string[i], debug_log_value[i]); i = (i+1) % DEBUG_LOG_MAX; } } used += sprintf(bigbuf + used, "\n"); #endif num_to_show = (fast_timers_started < NUM_TIMER_STATS ? fast_timers_started: NUM_TIMER_STATS); used += sprintf(bigbuf + used, "Timers started: %i\n", fast_timers_started); for (i = 0; i < num_to_show && (used+100 < BIG_BUF_SIZE) ; i++) { int cur = (fast_timers_started - i - 1) % NUM_TIMER_STATS; #if 1 //ndef FAST_TIMER_LOG used += sprintf(bigbuf + used, "div: %i delay: %i" "\n", timer_div_settings[cur], timer_delay_settings[cur] ); #endif #ifdef FAST_TIMER_LOG t = &timer_started_log[cur]; used += sprintf(bigbuf + used, "%-14s s: %6lu.%06lu e: %6lu.%06lu " "d: %6li us data: 0x%08lX" "\n", t->name, (unsigned long)t->tv_set.tv_jiff, (unsigned long)t->tv_set.tv_usec, (unsigned long)t->tv_expires.tv_jiff, (unsigned long)t->tv_expires.tv_usec, t->delay_us, t->data ); #endif } used += sprintf(bigbuf + used, "\n"); #ifdef FAST_TIMER_LOG num_to_show = (fast_timers_added < NUM_TIMER_STATS ? fast_timers_added: NUM_TIMER_STATS); used += sprintf(bigbuf + used, "Timers added: %i\n", fast_timers_added); for (i = 0; i < num_to_show && (used+100 < BIG_BUF_SIZE); i++) { t = &timer_added_log[(fast_timers_added - i - 1) % NUM_TIMER_STATS]; used += sprintf(bigbuf + used, "%-14s s: %6lu.%06lu e: %6lu.%06lu " "d: %6li us data: 0x%08lX" "\n", t->name, (unsigned long)t->tv_set.tv_jiff, (unsigned long)t->tv_set.tv_usec, (unsigned long)t->tv_expires.tv_jiff, (unsigned long)t->tv_expires.tv_usec, t->delay_us, t->data ); } used += sprintf(bigbuf + used, "\n"); num_to_show = (fast_timers_expired < NUM_TIMER_STATS ? fast_timers_expired: NUM_TIMER_STATS); used += sprintf(bigbuf + used, "Timers expired: %i\n", fast_timers_expired); for (i = 0; i < num_to_show && (used+100 < BIG_BUF_SIZE); i++) { t = &timer_expired_log[(fast_timers_expired - i - 1) % NUM_TIMER_STATS]; used += sprintf(bigbuf + used, "%-14s s: %6lu.%06lu e: %6lu.%06lu " "d: %6li us data: 0x%08lX" "\n", t->name, (unsigned long)t->tv_set.tv_jiff, (unsigned long)t->tv_set.tv_usec, (unsigned long)t->tv_expires.tv_jiff, (unsigned long)t->tv_expires.tv_usec, t->delay_us, t->data ); } used += sprintf(bigbuf + used, "\n"); #endif used += sprintf(bigbuf + used, "Active timers:\n"); local_irq_save(flags); t = fast_timer_list; while (t != NULL && (used+100 < BIG_BUF_SIZE)) { nextt = t->next; local_irq_restore(flags); used += sprintf(bigbuf + used, "%-14s s: %6lu.%06lu e: %6lu.%06lu " "d: %6li us data: 0x%08lX" /* " func: 0x%08lX" */ "\n", t->name, (unsigned long)t->tv_set.tv_jiff, (unsigned long)t->tv_set.tv_usec, (unsigned long)t->tv_expires.tv_jiff, (unsigned long)t->tv_expires.tv_usec, t->delay_us, t->data /* , t->function */ ); local_irq_save(flags); if (t->next != nextt) { printk("timer removed!\n"); } t = nextt; } local_irq_restore(flags); } if (used - offset < len) { len = used - offset; } memcpy(buf, bigbuf + offset, len); *start = buf; *eof = 1; return len; } #endif /* PROC_FS */ #ifdef FAST_TIMER_TEST static volatile unsigned long i = 0; static volatile int num_test_timeout = 0; static struct fast_timer tr[10]; static int exp_num[10]; static struct fasttime_t tv_exp[100]; static void test_timeout(unsigned long data) { do_gettimeofday_fast(&tv_exp[data]); exp_num[data] = num_test_timeout; num_test_timeout++; } static void test_timeout1(unsigned long data) { do_gettimeofday_fast(&tv_exp[data]); exp_num[data] = num_test_timeout; if (data < 7) { start_one_shot_timer(&tr[i], test_timeout1, i, 1000, "timeout1"); i++; } num_test_timeout++; } DP( static char buf0[2000]; static char buf1[2000]; static char buf2[2000]; static char buf3[2000]; static char buf4[2000]; ); static char buf5[6000]; static int j_u[1000]; static void fast_timer_test(void) { int prev_num; int j; struct fasttime_t tv, tv0, tv1, tv2; printk("fast_timer_test() start\n"); do_gettimeofday_fast(&tv); for (j = 0; j < 1000; j++) { j_u[j] = GET_JIFFIES_USEC(); } for (j = 0; j < 100; j++) { do_gettimeofday_fast(&tv_exp[j]); } printk(KERN_DEBUG "fast_timer_test() %is %06i\n", tv.tv_jiff, tv.tv_usec); for (j = 0; j < 1000; j++) { printk(KERN_DEBUG "%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]); j += 4; } for (j = 0; j < 100; j++) { printk(KERN_DEBUG "%i.%i %i.%i %i.%i %i.%i %i.%i\n", tv_exp[j].tv_jiff, tv_exp[j].tv_usec, tv_exp[j+1].tv_jiff, tv_exp[j+1].tv_usec, tv_exp[j+2].tv_jiff, tv_exp[j+2].tv_usec, tv_exp[j+3].tv_jiff, tv_exp[j+3].tv_usec, tv_exp[j+4].tv_jiff, tv_exp[j+4].tv_usec); j += 4; } do_gettimeofday_fast(&tv0); start_one_shot_timer(&tr[i], test_timeout, i, 50000, "test0"); DP(proc_fasttimer_read(buf0, NULL, 0, 0, 0)); i++; start_one_shot_timer(&tr[i], test_timeout, i, 70000, "test1"); DP(proc_fasttimer_read(buf1, NULL, 0, 0, 0)); i++; start_one_shot_timer(&tr[i], test_timeout, i, 40000, "test2"); DP(proc_fasttimer_read(buf2, NULL, 0, 0, 0)); i++; start_one_shot_timer(&tr[i], test_timeout, i, 60000, "test3"); DP(proc_fasttimer_read(buf3, NULL, 0, 0, 0)); i++; start_one_shot_timer(&tr[i], test_timeout1, i, 55000, "test4xx"); DP(proc_fasttimer_read(buf4, NULL, 0, 0, 0)); i++; do_gettimeofday_fast(&tv1); proc_fasttimer_read(buf5, NULL, 0, 0, 0); prev_num = num_test_timeout; while (num_test_timeout < i) { if (num_test_timeout != prev_num) prev_num = num_test_timeout; } do_gettimeofday_fast(&tv2); printk(KERN_INFO "Timers started %is %06i\n", tv0.tv_jiff, tv0.tv_usec); printk(KERN_INFO "Timers started at %is %06i\n", tv1.tv_jiff, tv1.tv_usec); printk(KERN_INFO "Timers done %is %06i\n", tv2.tv_jiff, tv2.tv_usec); DP(printk("buf0:\n"); printk(buf0); printk("buf1:\n"); printk(buf1); printk("buf2:\n"); printk(buf2); printk("buf3:\n"); printk(buf3); printk("buf4:\n"); printk(buf4); ); printk("buf5:\n"); printk(buf5); printk("timers set:\n"); for(j = 0; jname, t->tv_set.tv_jiff, t->tv_set.tv_usec, t->tv_expires.tv_jiff, t->tv_expires.tv_usec, t->data, t->function ); printk(" del: %6ius did exp: %6is %06ius as #%i error: %6li\n", t->delay_us, tv_exp[j].tv_jiff, tv_exp[j].tv_usec, exp_num[j], (tv_exp[j].tv_jiff - t->tv_expires.tv_jiff) * 1000000 + tv_exp[j].tv_usec - t->tv_expires.tv_usec); } proc_fasttimer_read(buf5, NULL, 0, 0, 0); printk("buf5 after all done:\n"); printk(buf5); printk("fast_timer_test() done\n"); } #endif int fast_timer_init(void) { /* For some reason, request_irq() hangs when called froom time_init() */ if (!fast_timer_is_init) { printk("fast_timer_init()\n"); #ifdef CONFIG_PROC_FS create_proc_read_entry("fasttimer", 0, NULL, proc_fasttimer_read, NULL); #endif /* PROC_FS */ if (request_irq(TIMER0_INTR_VECT, timer_trig_interrupt, IRQF_SHARED | IRQF_DISABLED, "fast timer int", &fast_timer_list)) printk(KERN_ERR "err: fasttimer irq\n"); fast_timer_is_init = 1; #ifdef FAST_TIMER_TEST printk("do test\n"); fast_timer_test(); #endif } return 0; } __initcall(fast_timer_init);