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1 jermar 1
/*
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 * Copyright (C) 2001-2004 Jakub Jermar
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 * All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 *
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 * - Redistributions of source code must retain the above copyright
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 *   notice, this list of conditions and the following disclaimer.
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 * - Redistributions in binary form must reproduce the above copyright
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 *   notice, this list of conditions and the following disclaimer in the
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 *   documentation and/or other materials provided with the distribution.
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 * - The name of the author may not be used to endorse or promote products
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 *   derived from this software without specific prior written permission.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 */
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#include <time/timeout.h>
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#include <typedefs.h>
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#include <arch/types.h>
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#include <config.h>
68 decky 33
#include <panic.h>
1 jermar 34
#include <synch/spinlock.h>
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#include <func.h>
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#include <cpu.h>
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#include <print.h>
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#include <arch/asm.h>
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#include <arch.h>
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107 decky 41
 
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/** Initialize timeouts
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 *
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 * Initialize kernel timeouts.
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 *
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 */
1 jermar 47
void timeout_init(void)
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{
15 jermar 49
    spinlock_initialize(&CPU->timeoutlock);
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    list_initialize(&CPU->timeout_active_head);
1 jermar 51
}
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107 decky 54
/** Initialize empty timeout list
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 *
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 * Initialize the timeout list to be empty.
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 *
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 * @param t Timeout list to be initialized.
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 *
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 */
1 jermar 61
void timeout_reinitialize(timeout_t *t)
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{
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    t->cpu = NULL;
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    t->ticks = 0;
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    t->handler = NULL;
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    t->arg = NULL;
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    link_initialize(&t->link);
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}
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107 decky 70
 
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/** Initialize timeout list
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 *
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 * Initialize the timeout list and its spinlock.
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 *
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 * @param t Timeout list to be initialized.
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 *
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 */
1 jermar 78
void timeout_initialize(timeout_t *t)
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{
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    spinlock_initialize(&t->lock);
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    timeout_reinitialize(t);
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}
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107 decky 84
 
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/** Register timeout callback
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 *
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 * Insert the timeout handler f (with argument arg)
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 * to the timeout list and make it execute in
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 * time microseconds (or slightly more).
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 *
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 * @param t    Timeout list.
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 * @patam time Number of usec in the future to execute
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 *             the handler.
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 * @param f    Timeout handler function.
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 * @param arg  Timeout handler argument.
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 *
1 jermar 97
 */
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void timeout_register(timeout_t *t, __u64 time, timeout_handler f, void *arg)
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{
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    timeout_t *hlp;
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    link_t *l, *m;
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    pri_t pri;
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    __u64 sum;
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    pri = cpu_priority_high();
15 jermar 106
    spinlock_lock(&CPU->timeoutlock);
1 jermar 107
    spinlock_lock(&t->lock);
125 jermar 108
 
1 jermar 109
    if (t->cpu)
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        panic("t->cpu != 0");
1 jermar 111
 
15 jermar 112
    t->cpu = CPU;
1 jermar 113
    t->ticks = us2ticks(time);
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    t->handler = f;
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    t->arg = arg;
125 jermar 117
 
1 jermar 118
    /*
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     * Insert t into the active timeouts list according to t->ticks.
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     */
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    sum = 0;
15 jermar 122
    l = CPU->timeout_active_head.next;
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    while (l != &CPU->timeout_active_head) {
1 jermar 124
        hlp = list_get_instance(l, timeout_t, link);
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        spinlock_lock(&hlp->lock);
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        if (t->ticks < sum + hlp->ticks) {
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            spinlock_unlock(&hlp->lock);
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            break;
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        }
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        sum += hlp->ticks;
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        spinlock_unlock(&hlp->lock);
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        l = l->next;
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    }
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    m = l->prev;
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    list_prepend(&t->link, m); /* avoid using l->prev */
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    /*
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     * Adjust t->ticks according to ticks accumulated in h's predecessors.
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     */
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    t->ticks -= sum;
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    /*
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     * Decrease ticks of t's immediate succesor by t->ticks.
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     */
15 jermar 145
    if (l != &CPU->timeout_active_head) {
1 jermar 146
        spinlock_lock(&hlp->lock);
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        hlp->ticks -= t->ticks;
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        spinlock_unlock(&hlp->lock);
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    }
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    spinlock_unlock(&t->lock);
15 jermar 152
    spinlock_unlock(&CPU->timeoutlock);
1 jermar 153
    cpu_priority_restore(pri);
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}
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107 decky 156
 
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/** Unregister timeout callback
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 *
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 * Remove timeout from timeout list.
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 *
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 * @param t Timeout to unregister.
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 *
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 */
1 jermar 164
int timeout_unregister(timeout_t *t)
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{
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    timeout_t *hlp;
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    link_t *l;
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    pri_t pri;
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grab_locks:
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    pri = cpu_priority_high();
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    spinlock_lock(&t->lock);
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    if (!t->cpu) {
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        spinlock_unlock(&t->lock);
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        cpu_priority_restore(pri);
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        return 0;
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    }
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    if (!spinlock_trylock(&t->cpu->timeoutlock)) {
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        spinlock_unlock(&t->lock);
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        cpu_priority_restore(pri);     
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        goto grab_locks;
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    }
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    /*
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     * Now we know for sure that t hasn't been activated yet
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     * and is lurking in t->cpu->timeout_active_head queue.
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     */
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    l = t->link.next;
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    if (l != &t->cpu->timeout_active_head) {
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        hlp = list_get_instance(l, timeout_t, link);
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        spinlock_lock(&hlp->lock);
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        hlp->ticks += t->ticks;
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        spinlock_unlock(&hlp->lock);
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    }
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    list_remove(&t->link);
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    spinlock_unlock(&t->cpu->timeoutlock);
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    timeout_reinitialize(t);
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    spinlock_unlock(&t->lock);
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203
    cpu_priority_restore(pri);
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    return 1;
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}