/**************************************************************************** * sched/wdog/wd_start.c * * Copyright (C) 2007-2009, 2012, 2014, 2016, 2018-2019 Gregory Nutt. All * rights reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include #include #include #include #include "sched/sched.h" #include "wdog/wdog.h" /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ #ifndef MIN # define MIN(a,b) (((a) < (b)) ? (a) : (b)) #endif #ifndef MAX # define MAX(a,b) (((a) > (b)) ? (a) : (b)) #endif /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: wd_expiration * * Description: * Check if the timer for the watchdog at the head of list is ready to * run. If so, remove the watchdog from the list and execute it. * * Input Parameters: * None * * Returned Value: * None * ****************************************************************************/ static inline void wd_expiration(void) { FAR struct wdog_s *wdog; /* Check if the watchdog at the head of the list is ready to run */ if (((FAR struct wdog_s *)g_wdactivelist.head)->lag <= 0) { /* Process the watchdog at the head of the list as well as any * other watchdogs that became ready to run at this time */ while (g_wdactivelist.head && ((FAR struct wdog_s *)g_wdactivelist.head)->lag <= 0) { /* Remove the watchdog from the head of the list */ wdog = (FAR struct wdog_s *)sq_remfirst(&g_wdactivelist); /* If there is another watchdog behind this one, update its * its lag (this shouldn't be necessary). */ if (g_wdactivelist.head) { ((FAR struct wdog_s *)g_wdactivelist.head)->lag += wdog->lag; } /* Indicate that the watchdog is no longer active. */ WDOG_CLRACTIVE(wdog); /* Execute the watchdog function */ up_setpicbase(wdog->picbase); #if CONFIG_MAX_WDOGPARMS == 0 wdog->func(0); #elif CONFIG_MAX_WDOGPARMS == 1 wdog->func((int)wdog->argc, wdog->parm[0]); #elif CONFIG_MAX_WDOGPARMS == 2 wdog->func((int)wdog->argc, wdog->parm[0], wdog->parm[1]); #elif CONFIG_MAX_WDOGPARMS == 3 wdog->func((int)wdog->argc, wdog->parm[0], wdog->parm[1], wdog->parm[2]); #elif CONFIG_MAX_WDOGPARMS == 4 wdog->func((int)wdog->argc, wdog->parm[0], wdog->parm[1], wdog->parm[2], wdog->parm[3]); #else # error Missing support #endif } } } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: wd_start * * Description: * This function adds a watchdog timer to the active timer queue. The * specified watchdog function at 'wdentry' will be called from the * interrupt level after the specified number of ticks has elapsed. * Watchdog timers may be started from the interrupt level. * * Watchdog timers execute in the address environment that was in effect * when wd_start() is called. * * Watchdog timers execute only once. * * To replace either the timeout delay or the function to be executed, * call wd_start again with the same wdog; only the most recent wdStart() * on a given watchdog ID has any effect. * * Input Parameters: * wdog - watchdog ID * delay - Delay count in clock ticks * wdentry - function to call on timeout * parm1..4 - parameters to pass to wdentry * * Returned Value: * Zero (OK) is returned on success; a negated errno value is return to * indicate the nature of any failure. * * Assumptions: * The watchdog routine runs in the context of the timer interrupt handler * and is subject to all ISR restrictions. * ****************************************************************************/ int wd_start(WDOG_ID wdog, int32_t delay, wdentry_t wdentry, int argc, ...) { va_list ap; FAR struct wdog_s *curr; FAR struct wdog_s *prev; FAR struct wdog_s *next; int32_t now; irqstate_t flags; int i; /* Verify the wdog and setup parameters */ if (wdog == NULL || argc > CONFIG_MAX_WDOGPARMS || delay < 0) { return -EINVAL; } /* Check if the watchdog has been started. If so, stop it. * NOTE: There is a race condition here... the caller may receive * the watchdog between the time that wd_start is called and * the critical section is established. */ flags = enter_critical_section(); if (WDOG_ISACTIVE(wdog)) { wd_cancel(wdog); } /* Save the data in the watchdog structure */ wdog->func = wdentry; /* Function to execute when delay expires */ up_getpicbase(&wdog->picbase); wdog->argc = argc; va_start(ap, argc); for (i = 0; i < argc; i++) { wdog->parm[i] = va_arg(ap, wdparm_t); } #ifdef CONFIG_DEBUG_FEATURES for (; i < CONFIG_MAX_WDOGPARMS; i++) { wdog->parm[i] = 0; } #endif va_end(ap); /* Calculate delay+1, forcing the delay into a range that we can handle */ if (delay <= 0) { delay = 1; } else if (++delay <= 0) { delay--; } #ifdef CONFIG_SCHED_TICKLESS /* Cancel the interval timer that drives the timing events. This will cause * wd_timer to be called which update the delay value for the first time * at the head of the timer list (there is a possibility that it could even * remove it). */ sched_timer_cancel(); #endif /* Do the easy case first -- when the watchdog timer queue is empty. */ if (g_wdactivelist.head == NULL) { #ifdef CONFIG_SCHED_TICKLESS /* Update clock tickbase */ g_wdtickbase = clock_systimer(); #endif /* Add the watchdog to the head == tail of the queue. */ sq_addlast((FAR sq_entry_t *)wdog, &g_wdactivelist); } /* There are other active watchdogs in the timer queue */ else { now = 0; prev = curr = (FAR struct wdog_s *)g_wdactivelist.head; /* Advance to positive time */ while ((now += curr->lag) < 0 && curr->next) { prev = curr; curr = curr->next; } /* Advance past shorter delays */ while (now <= delay && curr->next) { prev = curr; curr = curr->next; now += curr->lag; } /* Check if the new wdog must be inserted before the curr. */ if (delay < now) { /* The relative delay time is smaller or equal to the current delay * time, so decrement the current delay time by the new relative * delay time. */ delay -= (now - curr->lag); curr->lag -= delay; /* Insert the new watchdog in the list */ if (curr == (FAR struct wdog_s *)g_wdactivelist.head) { /* Insert the watchdog at the head of the list */ sq_addfirst((FAR sq_entry_t *)wdog, &g_wdactivelist); } else { /* Insert the watchdog in mid- or end-of-queue */ sq_addafter((FAR sq_entry_t *)prev, (FAR sq_entry_t *)wdog, &g_wdactivelist); } } /* The new watchdog delay time is greater than the curr delay time, * so the new wdog must be inserted after the curr. This only occurs * if the wdog is to be added to the end of the list. */ else { delay -= now; if (!curr->next) { sq_addlast((FAR sq_entry_t *)wdog, &g_wdactivelist); } else { next = curr->next; next->lag -= delay; sq_addafter((FAR sq_entry_t *)curr, (FAR sq_entry_t *)wdog, &g_wdactivelist); } } } /* Put the lag into the watchdog structure and mark it as active. */ wdog->lag = delay; WDOG_SETACTIVE(wdog); #ifdef CONFIG_SCHED_TICKLESS /* Resume the interval timer that will generate the next interval event. * If the timer at the head of the list changed, then this will pick that * new delay. */ sched_timer_resume(); #endif leave_critical_section(flags); return OK; } /**************************************************************************** * Name: wd_timer * * Description: * This function is called from the timer interrupt handler to determine * if it is time to execute a watchdog function. If so, the watchdog * function will be executed in the context of the timer interrupt * handler. * * Input Parameters: * ticks - If CONFIG_SCHED_TICKLESS is defined then the number of ticks * in the interval that just expired is provided. Otherwise, * this function is called on each timer interrupt and a value of one * is implicit. * * Returned Value: * If CONFIG_SCHED_TICKLESS is defined then the number of ticks for the * next delay is provided (zero if no delay). Otherwise, this function * has no returned value. * * Assumptions: * Called from interrupt handler logic with interrupts disabled. * ****************************************************************************/ #ifdef CONFIG_SCHED_TICKLESS unsigned int wd_timer(int ticks) { FAR struct wdog_s *wdog; #ifdef CONFIG_SMP irqstate_t flags; #endif unsigned int ret; int decr; #ifdef CONFIG_SMP /* We are in an interrupt handler as, as a consequence, interrupts are * disabled. But in the SMP case, interrupts MAY be disabled only on * the local CPU since most architectures do not permit disabling * interrupts on other CPUS. * * Hence, we must follow rules for critical sections even here in the * SMP case. */ flags = enter_critical_section(); #endif /* Check if there are any active watchdogs to process */ while (g_wdactivelist.head != NULL && ticks > 0) { /* Get the watchdog at the head of the list */ wdog = (FAR struct wdog_s *)g_wdactivelist.head; #ifndef CONFIG_SCHED_TICKLESS_ALARM /* There is logic to handle the case where ticks is greater than * the watchdog lag, but if the scheduling is working properly * that should never happen. */ DEBUGASSERT(ticks <= wdog->lag); #endif /* Decrement the lag for this watchdog. */ decr = MIN(wdog->lag, ticks); /* There are. Decrement the lag counter */ wdog->lag -= decr; ticks -= decr; g_wdtickbase += decr; /* Check if the watchdog at the head of the list is ready to run */ wd_expiration(); } /* Update clock tickbase */ g_wdtickbase += ticks; /* Return the delay for the next watchdog to expire */ ret = g_wdactivelist.head ? ((FAR struct wdog_s *)g_wdactivelist.head)->lag : 0; #ifdef CONFIG_SMP leave_critical_section(flags); #endif /* Return the delay for the next watchdog to expire */ return ret; } #else void wd_timer(void) { #ifdef CONFIG_SMP irqstate_t flags; /* We are in an interrupt handler as, as a consequence, interrupts are * disabled. But in the SMP case, interrupts MAY be disabled only on * the local CPU since most architectures do not permit disabling * interrupts on other CPUS. * * Hence, we must follow rules for critical sections even here in the * SMP case. */ flags = enter_critical_section(); #endif /* Check if there are any active watchdogs to process */ if (g_wdactivelist.head) { /* There are. Decrement the lag counter */ --(((FAR struct wdog_s *)g_wdactivelist.head)->lag); /* Check if the watchdog at the head of the list is ready to run */ wd_expiration(); } #ifdef CONFIG_SMP leave_critical_section(flags); #endif } #endif /* CONFIG_SCHED_TICKLESS */