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Ignore whitespace Rev 1786 → Rev 1787

/trunk/kernel/generic/src/time/delay.c
0,0 → 1,68
/*
* Copyright (C) 2001-2004 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - 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.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
 
/** @addtogroup time
* @{
*/
 
/**
* @file
* @brief Active delay function.
*/
#include <time/delay.h>
#include <arch/types.h>
#include <cpu.h>
#include <arch/asm.h>
#include <arch.h>
 
/** Active delay
*
* Delay the execution for the given number
* of microseconds (or slightly more). The delay
* is implemented as CPU calibrated active loop.
*
* @param usec Number of microseconds to sleep.
*/
void delay(uint32_t usec)
{
ipl_t ipl;
/*
* The delay loop is calibrated for each and every
* CPU in the system. Therefore it is necessary to
* call interrupts_disable() before calling the
* asm_delay_loop().
*/
ipl = interrupts_disable();
asm_delay_loop(usec * CPU->delay_loop_const);
interrupts_restore(ipl);
}
 
/** @}
*/
/trunk/kernel/generic/src/time/timeout.c
0,0 → 1,218
/*
* Copyright (C) 2001-2004 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - 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.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
 
/** @addtogroup time
* @{
*/
 
/**
* @file
* @brief Timeout management functions.
*/
 
#include <time/timeout.h>
#include <typedefs.h>
#include <arch/types.h>
#include <config.h>
#include <panic.h>
#include <synch/spinlock.h>
#include <func.h>
#include <cpu.h>
#include <arch/asm.h>
#include <arch.h>
 
 
/** Initialize timeouts
*
* Initialize kernel timeouts.
*
*/
void timeout_init(void)
{
spinlock_initialize(&CPU->timeoutlock, "timeout_lock");
list_initialize(&CPU->timeout_active_head);
}
 
 
/** Reinitialize timeout
*
* Initialize all members except the lock.
*
* @param t Timeout to be initialized.
*
*/
void timeout_reinitialize(timeout_t *t)
{
t->cpu = NULL;
t->ticks = 0;
t->handler = NULL;
t->arg = NULL;
link_initialize(&t->link);
}
 
 
/** Initialize timeout
*
* Initialize all members including the lock.
*
* @param t Timeout to be initialized.
*
*/
void timeout_initialize(timeout_t *t)
{
spinlock_initialize(&t->lock, "timeout_t_lock");
timeout_reinitialize(t);
}
 
 
/** Register timeout
*
* Insert timeout handler f (with argument arg)
* to timeout list and make it execute in
* time microseconds (or slightly more).
*
* @param t Timeout structure.
* @param time Number of usec in the future to execute
* the handler.
* @param f Timeout handler function.
* @param arg Timeout handler argument.
*
*/
void timeout_register(timeout_t *t, uint64_t time, timeout_handler_t f, void *arg)
{
timeout_t *hlp = NULL;
link_t *l, *m;
ipl_t ipl;
uint64_t sum;
 
ipl = interrupts_disable();
spinlock_lock(&CPU->timeoutlock);
spinlock_lock(&t->lock);
 
if (t->cpu)
panic("t->cpu != 0");
 
t->cpu = CPU;
t->ticks = us2ticks(time);
t->handler = f;
t->arg = arg;
 
/*
* Insert t into the active timeouts list according to t->ticks.
*/
sum = 0;
l = CPU->timeout_active_head.next;
while (l != &CPU->timeout_active_head) {
hlp = list_get_instance(l, timeout_t, link);
spinlock_lock(&hlp->lock);
if (t->ticks < sum + hlp->ticks) {
spinlock_unlock(&hlp->lock);
break;
}
sum += hlp->ticks;
spinlock_unlock(&hlp->lock);
l = l->next;
}
 
m = l->prev;
list_prepend(&t->link, m); /* avoid using l->prev */
 
/*
* Adjust t->ticks according to ticks accumulated in h's predecessors.
*/
t->ticks -= sum;
 
/*
* Decrease ticks of t's immediate succesor by t->ticks.
*/
if (l != &CPU->timeout_active_head) {
spinlock_lock(&hlp->lock);
hlp->ticks -= t->ticks;
spinlock_unlock(&hlp->lock);
}
 
spinlock_unlock(&t->lock);
spinlock_unlock(&CPU->timeoutlock);
interrupts_restore(ipl);
}
 
 
/** Unregister timeout
*
* Remove timeout from timeout list.
*
* @param t Timeout to unregister.
*
* @return true on success, false on failure.
*/
bool timeout_unregister(timeout_t *t)
{
timeout_t *hlp;
link_t *l;
ipl_t ipl;
 
grab_locks:
ipl = interrupts_disable();
spinlock_lock(&t->lock);
if (!t->cpu) {
spinlock_unlock(&t->lock);
interrupts_restore(ipl);
return false;
}
if (!spinlock_trylock(&t->cpu->timeoutlock)) {
spinlock_unlock(&t->lock);
interrupts_restore(ipl);
goto grab_locks;
}
/*
* Now we know for sure that t hasn't been activated yet
* and is lurking in t->cpu->timeout_active_head queue.
*/
 
l = t->link.next;
if (l != &t->cpu->timeout_active_head) {
hlp = list_get_instance(l, timeout_t, link);
spinlock_lock(&hlp->lock);
hlp->ticks += t->ticks;
spinlock_unlock(&hlp->lock);
}
list_remove(&t->link);
spinlock_unlock(&t->cpu->timeoutlock);
 
timeout_reinitialize(t);
spinlock_unlock(&t->lock);
 
interrupts_restore(ipl);
return true;
}
 
/** @}
*/
/trunk/kernel/generic/src/time/clock.c
0,0 → 1,191
/*
* Copyright (C) 2001-2004 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - 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.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
 
/** @addtogroup time
* @{
*/
 
/**
* @file
* @brief High-level clock interrupt handler.
*
* This file contains the clock() function which is the source
* of preemption. It is also responsible for executing expired
* timeouts.
*/
#include <time/clock.h>
#include <time/timeout.h>
#include <arch/types.h>
#include <config.h>
#include <synch/spinlock.h>
#include <synch/waitq.h>
#include <func.h>
#include <proc/scheduler.h>
#include <cpu.h>
#include <arch.h>
#include <adt/list.h>
#include <atomic.h>
#include <proc/thread.h>
#include <sysinfo/sysinfo.h>
#include <arch/barrier.h>
 
/* Pointers to public variables with time */
struct ptime {
unative_t seconds1;
unative_t useconds;
unative_t seconds2;
};
struct ptime *public_time;
/* Variable holding fragment of second, so that we would update
* seconds correctly
*/
static unative_t secfrag = 0;
 
/** Initialize realtime clock counter
*
* The applications (and sometimes kernel) need to access accurate
* information about realtime data. We allocate 1 page with these
* data and update it periodically.
*
*
*/
void clock_counter_init(void)
{
void *faddr;
 
faddr = frame_alloc(0, FRAME_ATOMIC);
if (!faddr)
panic("Cannot allocate page for clock");
public_time = (struct ptime *)PA2KA(faddr);
 
/* TODO: We would need some arch dependent settings here */
public_time->seconds1 = 0;
public_time->seconds2 = 0;
public_time->useconds = 0;
 
sysinfo_set_item_val("clock.faddr", NULL, (unative_t)faddr);
}
 
 
/** Update public counters
*
* Update it only on first processor
* TODO: Do we really need so many write barriers?
*/
static void clock_update_counters(void)
{
if (CPU->id == 0) {
secfrag += 1000000/HZ;
if (secfrag >= 1000000) {
secfrag -= 1000000;
public_time->seconds1++;
write_barrier();
public_time->useconds = secfrag;
write_barrier();
public_time->seconds2 = public_time->seconds1;
} else
public_time->useconds += 1000000/HZ;
}
}
 
/** Clock routine
*
* Clock routine executed from clock interrupt handler
* (assuming interrupts_disable()'d). Runs expired timeouts
* and preemptive scheduling.
*
*/
void clock(void)
{
link_t *l;
timeout_t *h;
timeout_handler_t f;
void *arg;
count_t missed_clock_ticks = CPU->missed_clock_ticks;
int i;
 
/*
* To avoid lock ordering problems,
* run all expired timeouts as you visit them.
*/
for (i = 0; i <= missed_clock_ticks; i++) {
clock_update_counters();
spinlock_lock(&CPU->timeoutlock);
while ((l = CPU->timeout_active_head.next) != &CPU->timeout_active_head) {
h = list_get_instance(l, timeout_t, link);
spinlock_lock(&h->lock);
if (h->ticks-- != 0) {
spinlock_unlock(&h->lock);
break;
}
list_remove(l);
f = h->handler;
arg = h->arg;
timeout_reinitialize(h);
spinlock_unlock(&h->lock);
spinlock_unlock(&CPU->timeoutlock);
 
f(arg);
 
spinlock_lock(&CPU->timeoutlock);
}
spinlock_unlock(&CPU->timeoutlock);
}
CPU->missed_clock_ticks = 0;
 
/*
* Do CPU usage accounting and find out whether to preempt THREAD.
*/
 
if (THREAD) {
uint64_t ticks;
spinlock_lock(&CPU->lock);
CPU->needs_relink += 1 + missed_clock_ticks;
spinlock_unlock(&CPU->lock);
spinlock_lock(&THREAD->lock);
if ((ticks = THREAD->ticks)) {
if (ticks >= 1 + missed_clock_ticks)
THREAD->ticks -= 1 + missed_clock_ticks;
else
THREAD->ticks = 0;
}
spinlock_unlock(&THREAD->lock);
if (!ticks && !PREEMPTION_DISABLED) {
scheduler();
}
}
 
}
 
/** @}
*/