05f6ee66ea
- If possible, context switch to the thread directly in sched_ithd(), rather than triggering a delayed ast reschedule. - Disable interrupts while restoring fpu state in the trap handler, in order to ensure that we are not preempted in the middle, which could cause migration to another cpu. Reviewed by: peter Tested by: peter (alpha)
223 lines
6.6 KiB
C
223 lines
6.6 KiB
C
/*-
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* Copyright (c) 1997 Berkeley Software Design, Inc. 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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* 1. 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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* 2. 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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* 3. Berkeley Software Design Inc's name may not be used to endorse or
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* promote products derived from this software without specific prior
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* written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* From BSDI: intr.c,v 1.6.2.5 1999/07/06 19:16:52 cp Exp
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* $FreeBSD$
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*/
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/* Interrupt thread code. */
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#include "opt_auto_eoi.h"
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#include <sys/param.h>
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#include <sys/bus.h>
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#include <sys/rtprio.h> /* change this name XXX */
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#ifndef SMP
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#include <machine/lock.h>
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#endif
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#include <sys/proc.h>
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#include <sys/systm.h>
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#include <sys/syslog.h>
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#include <sys/ipl.h>
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#include <sys/kernel.h>
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#include <sys/kthread.h>
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#include <sys/malloc.h>
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#include <sys/module.h>
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#include <sys/mutex.h>
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#include <sys/unistd.h>
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#include <sys/errno.h>
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#include <sys/interrupt.h>
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#include <machine/md_var.h>
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#include <machine/segments.h>
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#include <i386/isa/icu.h>
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#include <isa/isavar.h>
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#include <i386/isa/intr_machdep.h>
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#include <sys/interrupt.h>
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#include <sys/vmmeter.h>
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#include <sys/ktr.h>
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#include <machine/cpu.h>
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static u_int straycount[NHWI];
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#define MAX_STRAY_LOG 5
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/*
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* Schedule a heavyweight interrupt process. This function is called
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* from the interrupt handlers Xintr<num>.
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*/
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void
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sched_ithd(void *cookie)
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{
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int irq = (int) cookie; /* IRQ we're handling */
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struct ithd *ir = ithds[irq]; /* and the process that does it */
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/* This used to be in icu_vector.s */
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/*
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* We count software interrupts when we process them. The
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* code here follows previous practice, but there's an
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* argument for counting hardware interrupts when they're
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* processed too.
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*/
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atomic_add_long(intr_countp[irq], 1); /* one more for this IRQ */
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atomic_add_int(&cnt.v_intr, 1); /* one more global interrupt */
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/*
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* If we don't have an interrupt resource or an interrupt thread for
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* this IRQ, log it as a stray interrupt.
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*/
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if (ir == NULL || ir->it_proc == NULL) {
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if (straycount[irq] < MAX_STRAY_LOG) {
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printf("stray irq %d\n", irq);
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if (++straycount[irq] == MAX_STRAY_LOG)
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printf(
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"got %d stray irq %d's: not logging anymore\n",
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MAX_STRAY_LOG, irq);
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}
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return;
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}
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CTR3(KTR_INTR, "sched_ithd pid %d(%s) need=%d",
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ir->it_proc->p_pid, ir->it_proc->p_comm, ir->it_need);
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/*
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* Set it_need so that if the thread is already running but close
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* to done, it will do another go-round. Then get the sched lock
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* and see if the thread is on whichkqs yet. If not, put it on
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* there. In any case, kick everyone so that if the new thread
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* is higher priority than their current thread, it gets run now.
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*/
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ir->it_need = 1;
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mtx_enter(&sched_lock, MTX_SPIN);
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if (ir->it_proc->p_stat == SWAIT) { /* not on run queue */
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CTR1(KTR_INTR, "sched_ithd: setrunqueue %d",
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ir->it_proc->p_pid);
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/* membar_lock(); */
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ir->it_proc->p_stat = SRUN;
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setrunqueue(ir->it_proc);
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if (!cold) {
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if (curproc != PCPU_GET(idleproc))
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setrunqueue(curproc);
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mi_switch();
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}
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}
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else {
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CTR3(KTR_INTR, "sched_ithd %d: it_need %d, state %d",
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ir->it_proc->p_pid,
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ir->it_need,
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ir->it_proc->p_stat );
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need_resched();
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}
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mtx_exit(&sched_lock, MTX_SPIN);
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}
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/*
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* This is the main code for all interrupt threads. It gets put on
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* whichkqs by setrunqueue above.
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*/
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void
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ithd_loop(void *dummy)
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{
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struct ithd *me; /* our thread context */
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struct intrhand *ih; /* and our interrupt handler chain */
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me = curproc->p_ithd; /* point to myself */
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/*
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* As long as we have interrupts outstanding, go through the
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* list of handlers, giving each one a go at it.
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*/
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for (;;) {
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/*
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* If we don't have any handlers, then we are an orphaned
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* thread and just need to die.
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*/
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if (me->it_ih == NULL) {
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CTR2(KTR_INTR, "ithd_loop pid %d(%s) exiting",
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me->it_proc->p_pid, me->it_proc->p_comm);
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curproc->p_ithd = NULL;
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free(me, M_DEVBUF);
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mtx_enter(&Giant, MTX_DEF);
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kthread_exit(0);
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}
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CTR3(KTR_INTR, "ithd_loop pid %d(%s) need=%d",
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me->it_proc->p_pid, me->it_proc->p_comm, me->it_need);
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while (me->it_need) {
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/*
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* Service interrupts. If another interrupt
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* arrives while we are running, they will set
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* it_need to denote that we should make
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* another pass.
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*/
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me->it_need = 0;
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#if 0
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membar_unlock(); /* push out "it_need=0" */
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#endif
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for (ih = me->it_ih; ih != NULL; ih = ih->ih_next) {
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CTR5(KTR_INTR,
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"ithd_loop pid %d ih=%p: %p(%p) flg=%x",
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me->it_proc->p_pid, (void *)ih,
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(void *)ih->ih_handler, ih->ih_argument,
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ih->ih_flags);
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if ((ih->ih_flags & INTR_MPSAFE) == 0)
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mtx_enter(&Giant, MTX_DEF);
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ih->ih_handler(ih->ih_argument);
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if ((ih->ih_flags & INTR_MPSAFE) == 0)
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mtx_exit(&Giant, MTX_DEF);
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}
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}
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/*
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* Processed all our interrupts. Now get the sched
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* lock. This may take a while and it_need may get
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* set again, so we have to check it again.
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*/
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mtx_assert(&Giant, MA_NOTOWNED);
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mtx_enter(&sched_lock, MTX_SPIN);
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if (!me->it_need) {
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INTREN (1 << me->irq); /* reset the mask bit */
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me->it_proc->p_stat = SWAIT; /* we're idle */
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#ifdef APIC_IO
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CTR2(KTR_INTR, "ithd_loop pid %d: done, apic_imen=%x",
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me->it_proc->p_pid, apic_imen);
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#else
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CTR2(KTR_INTR, "ithd_loop pid %d: done, imen=%x",
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me->it_proc->p_pid, imen);
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#endif
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mi_switch();
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CTR1(KTR_INTR, "ithd_loop pid %d: resumed",
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me->it_proc->p_pid);
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}
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mtx_exit(&sched_lock, MTX_SPIN);
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}
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}
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