freebsd-nq/sys/amd64/isa/ithread.c
Jason Evans 0384fff8c5 Major update to the way synchronization is done in the kernel. Highlights
include:

* Mutual exclusion is used instead of spl*().  See mutex(9).  (Note: The
  alpha port is still in transition and currently uses both.)

* Per-CPU idle processes.

* Interrupts are run in their own separate kernel threads and can be
  preempted (i386 only).

Partially contributed by:	BSDi (BSD/OS)
Submissions by (at least):	cp, dfr, dillon, grog, jake, jhb, sheldonh
2000-09-07 01:33:02 +00:00

354 lines
9.6 KiB
C

/*-
* Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved.
*
* 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. Berkeley Software Design Inc's name may not be used to endorse or
* promote products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``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 BERKELEY SOFTWARE DESIGN INC 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.
*
* From BSDI: intr.c,v 1.6.2.5 1999/07/06 19:16:52 cp Exp
* $FreeBSD$
*/
/* Interrupt thread code. */
#include "opt_auto_eoi.h"
#include "isa.h"
#include <sys/param.h>
#include <sys/rtprio.h> /* change this name XXX */
#ifndef SMP
#include <machine/lock.h>
#endif
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/syslog.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/unistd.h>
#include <sys/errno.h>
#include <sys/interrupt.h>
#include <machine/ipl.h>
#include <machine/md_var.h>
#include <machine/segments.h>
#include <sys/bus.h>
#if defined(APIC_IO)
#include <machine/smp.h>
#include <machine/smptests.h> /** FAST_HI */
#include <machine/resource.h>
#endif /* APIC_IO */
#ifdef PC98
#include <pc98/pc98/pc98.h>
#include <pc98/pc98/pc98_machdep.h>
#include <pc98/pc98/epsonio.h>
#else
#include <i386/isa/isa.h>
#endif
#include <i386/isa/icu.h>
#if NISA > 0
#include <isa/isavar.h>
#endif
#include <i386/isa/intr_machdep.h>
#include <sys/interrupt.h>
#ifdef APIC_IO
#include <machine/clock.h>
#endif
#include "mca.h"
#if NMCA > 0
#include <i386/isa/mca_machdep.h>
#endif
#include <sys/vmmeter.h>
#include <machine/mutex.h>
#include <sys/ktr.h>
#include <machine/cpu.h>
#if 0
#include <ddb/ddb.h>
#endif
u_long softintrcnt [NSWI];
SYSINIT(start_softintr, SI_SUB_SOFTINTR, SI_ORDER_FIRST, start_softintr, NULL)
/*
* Schedule a heavyweight interrupt process. This function is called
* from the interrupt handlers Xintr<num>.
*/
void
sched_ithd(void *cookie)
{
int irq = (int) cookie; /* IRQ we're handling */
ithd *ir = ithds[irq]; /* and the process that does it */
/* This used to be in icu_vector.s */
/*
* We count software interrupts when we process them. The
* code here follows previous practice, but there's an
* argument for counting hardware interrupts when they're
* processed too.
*/
if (irq < NHWI) /* real interrupt, */
atomic_add_long(intr_countp[irq], 1); /* one more for this IRQ */
atomic_add_int(&cnt.v_intr, 1); /* one more global interrupt */
CTR3(KTR_INTR, "sched_ithd pid %d(%s) need=%d",
ir->it_proc->p_pid, ir->it_proc->p_comm, ir->it_need);
#if 0
/*
* If we are in the debugger, we can't use interrupt threads to
* process interrupts since the threads are scheduled. Instead,
* call the interrupt handlers directly. This should be able to
* go away once we have light-weight interrupt handlers.
*/
if (db_active) {
intrec *ih; /* and our interrupt handler chain */
#if 0
membar_unlock(); /* push out "it_need=0" */
#endif
for (ih = ir->it_ih; ih != NULL; ih = ih->next) {
if ((ih->flags & INTR_MPSAFE) == 0)
mtx_enter(&Giant, MTX_DEF);
ih->handler(ih->argument);
if ((ih->flags & INTR_MPSAFE) == 0)
mtx_exit(&Giant, MTX_DEF);
}
INTREN (1 << ir->irq); /* reset the mask bit */
return;
}
#endif
/*
* Set it_need so that if the thread is already running but close
* to done, it will do another go-round. Then get the sched lock
* and see if the thread is on whichkqs yet. If not, put it on
* there. In any case, kick everyone so that if the new thread
* is higher priority than their current thread, it gets run now.
*/
ir->it_need = 1;
mtx_enter(&sched_lock, MTX_SPIN);
if (ir->it_proc->p_stat == SWAIT) { /* not on run queue */
CTR1(KTR_INTR, "sched_ithd: setrunqueue %d",
ir->it_proc->p_pid);
/* membar_lock(); */
ir->it_proc->p_stat = SRUN;
setrunqueue(ir->it_proc);
aston();
}
else {
if (irq < NHWI && (irq & 7) != 0)
CTR3(KTR_INTR, "sched_ithd %d: it_need %d, state %d",
ir->it_proc->p_pid,
ir->it_need,
ir->it_proc->p_stat );
}
mtx_exit(&sched_lock, MTX_SPIN);
#if 0
aston(); /* ??? check priorities first? */
#else
need_resched();
#endif
}
/*
* This is the main code for all interrupt threads. It gets put on
* whichkqs by setrunqueue above.
*/
void
ithd_loop(void *dummy)
{
ithd *me; /* our thread context */
intrec *ih; /* and our interrupt handler chain */
me = curproc->p_ithd; /* point to myself */
/*
* As long as we have interrupts outstanding, go through the
* list of handlers, giving each one a go at it.
*/
for (;;) {
CTR3(KTR_INTR, "ithd_loop pid %d(%s) need=%d",
me->it_proc->p_pid, me->it_proc->p_comm, me->it_need);
while (me->it_need) {
/*
* Service interrupts. If another interrupt
* arrives while we are running, they will set
* it_need to denote that we should make
* another pass.
*/
me->it_need = 0;
#if 0
membar_unlock(); /* push out "it_need=0" */
#endif
for (ih = me->it_ih; ih != NULL; ih = ih->next) {
CTR5(KTR_INTR,
"ithd_loop pid %d ih=%p: %p(%p) flg=%x",
me->it_proc->p_pid, (void *)ih,
(void *)ih->handler, ih->argument,
ih->flags);
if ((ih->flags & INTR_MPSAFE) == 0)
mtx_enter(&Giant, MTX_DEF);
ih->handler(ih->argument);
if ((ih->flags & INTR_MPSAFE) == 0)
mtx_exit(&Giant, MTX_DEF);
}
}
/*
* Processed all our interrupts. Now get the sched
* lock. This may take a while and it_need may get
* set again, so we have to check it again.
*/
mtx_enter(&sched_lock, MTX_SPIN);
if (!me->it_need) {
INTREN (1 << me->irq); /* reset the mask bit */
me->it_proc->p_stat = SWAIT; /* we're idle */
#ifdef APIC_IO
CTR1(KTR_INTR, "ithd_loop pid %d: done",
me->it_proc->p_pid);
#else
CTR2(KTR_INTR, "ithd_loop pid %d: done, imen=%x",
me->it_proc->p_pid, imen);
#endif
mi_switch();
CTR1(KTR_INTR, "ithd_loop pid %d: resumed",
me->it_proc->p_pid);
}
mtx_exit(&sched_lock, MTX_SPIN);
}
}
/*
* Start soft interrupt thread.
*/
void
start_softintr(void *dummy)
{
int error;
struct proc *p;
ithd *softintr; /* descriptor for the "IRQ" */
intrec *idesc; /* descriptor for this handler */
char *name = "sintr"; /* name for idesc */
int i;
if (ithds[SOFTINTR]) { /* we already have a thread */
printf("start_softintr: already running");
return;
}
/* first handler for this irq. */
softintr = malloc(sizeof (struct ithd), M_DEVBUF, M_WAITOK);
if (softintr == NULL)
panic ("Can't create soft interrupt thread");
bzero(softintr, sizeof(struct ithd));
softintr->irq = SOFTINTR;
ithds[SOFTINTR] = softintr;
error = kthread_create(intr_soft, NULL, &p,
RFSTOPPED | RFHIGHPID, "softinterrupt");
if (error)
panic("start_softintr: kthread_create error %d\n", error);
p->p_rtprio.type = RTP_PRIO_ITHREAD;
p->p_rtprio.prio = PI_SOFT; /* soft interrupt */
p->p_stat = SWAIT; /* we're idle */
/* Put in linkages. */
softintr->it_proc = p;
p->p_ithd = softintr; /* reverse link */
idesc = malloc(sizeof (struct intrec), M_DEVBUF, M_WAITOK);
if (idesc == NULL)
panic ("Can't create soft interrupt thread");
bzero(idesc, sizeof (struct intrec));
idesc->ithd = softintr;
idesc->name = malloc(strlen(name) + 1, M_DEVBUF, M_WAITOK);
if (idesc->name == NULL)
panic ("Can't create soft interrupt thread");
strcpy(idesc->name, name);
for (i = NHWI; i < NHWI + NSWI; i++)
intr_countp[i] = &softintrcnt [i - NHWI];
}
/*
* Software interrupt process code.
*/
void
intr_soft(void *dummy)
{
int i;
ithd *me; /* our thread context */
me = curproc->p_ithd; /* point to myself */
/* Main loop */
for (;;) {
#if 0
CTR3(KTR_INTR, "intr_soft pid %d(%s) need=%d",
me->it_proc->p_pid, me->it_proc->p_comm,
me->it_need);
#endif
/*
* Service interrupts. If another interrupt arrives
* while we are running, they will set it_need to
* denote that we should make another pass.
*/
me->it_need = 0;
while ((i = ffs(spending))) {
i--;
atomic_add_long(intr_countp[i], 1);
spending &= ~ (1 << i);
mtx_enter(&Giant, MTX_DEF);
(ihandlers[i])();
mtx_exit(&Giant, MTX_DEF);
}
/*
* Processed all our interrupts. Now get the sched
* lock. This may take a while and it_need may get
* set again, so we have to check it again.
*/
mtx_enter(&sched_lock, MTX_SPIN);
if (!me->it_need) {
#if 0
CTR1(KTR_INTR, "intr_soft pid %d: done",
me->it_proc->p_pid);
#endif
me->it_proc->p_stat = SWAIT; /* we're idle */
mi_switch();
#if 0
CTR1(KTR_INTR, "intr_soft pid %d: resumed",
me->it_proc->p_pid);
#endif
}
mtx_exit(&sched_lock, MTX_SPIN);
}
}