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0f180a7cce
if the specified priority is zero. This avoids a race where the calling thread could read a snapshot of it's current priority, then a different thread could change the first thread's priority, then the original thread would call sched_prio() inside msleep() undoing the change made by the second thread. I used a priority of zero as no thread that calls msleep() or tsleep() should be specifying a priority of zero anyway. The various places that passed 'curthread->td_priority' or some variant as the priority now pass 0.
992 lines
24 KiB
C
992 lines
24 KiB
C
/*-
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* Copyright (c) 1997, Stefan Esser <se@freebsd.org>
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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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* 1. Redistributions of source code must retain the above copyright
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* notice unmodified, this list of conditions, and the following
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* 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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*
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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 <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include "opt_ddb.h"
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#include <sys/param.h>
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#include <sys/bus.h>
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#include <sys/conf.h>
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#include <sys/rtprio.h>
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#include <sys/systm.h>
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#include <sys/interrupt.h>
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#include <sys/kernel.h>
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#include <sys/kthread.h>
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#include <sys/ktr.h>
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#include <sys/limits.h>
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#include <sys/lock.h>
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#include <sys/malloc.h>
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#include <sys/mutex.h>
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#include <sys/proc.h>
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#include <sys/random.h>
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#include <sys/resourcevar.h>
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#include <sys/sched.h>
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#include <sys/sysctl.h>
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#include <sys/unistd.h>
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#include <sys/vmmeter.h>
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#include <machine/atomic.h>
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#include <machine/cpu.h>
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#include <machine/md_var.h>
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#include <machine/stdarg.h>
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#ifdef DDB
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#include <ddb/ddb.h>
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#include <ddb/db_sym.h>
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#endif
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/*
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* Describe an interrupt thread. There is one of these per interrupt event.
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*/
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struct intr_thread {
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struct intr_event *it_event;
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struct thread *it_thread; /* Kernel thread. */
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int it_flags; /* (j) IT_* flags. */
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int it_need; /* Needs service. */
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};
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/* Interrupt thread flags kept in it_flags */
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#define IT_DEAD 0x000001 /* Thread is waiting to exit. */
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struct intr_entropy {
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struct thread *td;
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uintptr_t event;
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};
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struct intr_event *clk_intr_event;
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struct intr_event *tty_intr_event;
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void *softclock_ih;
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void *vm_ih;
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static MALLOC_DEFINE(M_ITHREAD, "ithread", "Interrupt Threads");
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static int intr_storm_threshold = 500;
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TUNABLE_INT("hw.intr_storm_threshold", &intr_storm_threshold);
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SYSCTL_INT(_hw, OID_AUTO, intr_storm_threshold, CTLFLAG_RW,
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&intr_storm_threshold, 0,
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"Number of consecutive interrupts before storm protection is enabled");
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static TAILQ_HEAD(, intr_event) event_list =
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TAILQ_HEAD_INITIALIZER(event_list);
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static void intr_event_update(struct intr_event *ie);
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static struct intr_thread *ithread_create(const char *name);
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static void ithread_destroy(struct intr_thread *ithread);
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static void ithread_execute_handlers(struct proc *p, struct intr_event *ie);
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static void ithread_loop(void *);
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static void ithread_update(struct intr_thread *ithd);
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static void start_softintr(void *);
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u_char
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intr_priority(enum intr_type flags)
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{
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u_char pri;
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flags &= (INTR_TYPE_TTY | INTR_TYPE_BIO | INTR_TYPE_NET |
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INTR_TYPE_CAM | INTR_TYPE_MISC | INTR_TYPE_CLK | INTR_TYPE_AV);
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switch (flags) {
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case INTR_TYPE_TTY:
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pri = PI_TTYLOW;
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break;
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case INTR_TYPE_BIO:
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/*
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* XXX We need to refine this. BSD/OS distinguishes
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* between tape and disk priorities.
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*/
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pri = PI_DISK;
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break;
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case INTR_TYPE_NET:
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pri = PI_NET;
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break;
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case INTR_TYPE_CAM:
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pri = PI_DISK; /* XXX or PI_CAM? */
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break;
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case INTR_TYPE_AV: /* Audio/video */
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pri = PI_AV;
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break;
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case INTR_TYPE_CLK:
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pri = PI_REALTIME;
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break;
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case INTR_TYPE_MISC:
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pri = PI_DULL; /* don't care */
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break;
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default:
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/* We didn't specify an interrupt level. */
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panic("intr_priority: no interrupt type in flags");
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}
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return pri;
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}
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/*
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* Update an ithread based on the associated intr_event.
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*/
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static void
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ithread_update(struct intr_thread *ithd)
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{
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struct intr_event *ie;
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struct thread *td;
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u_char pri;
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ie = ithd->it_event;
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td = ithd->it_thread;
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/* Determine the overall priority of this event. */
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if (TAILQ_EMPTY(&ie->ie_handlers))
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pri = PRI_MAX_ITHD;
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else
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pri = TAILQ_FIRST(&ie->ie_handlers)->ih_pri;
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/* Update name and priority. */
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strlcpy(td->td_proc->p_comm, ie->ie_fullname,
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sizeof(td->td_proc->p_comm));
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mtx_lock_spin(&sched_lock);
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sched_prio(td, pri);
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mtx_unlock_spin(&sched_lock);
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}
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/*
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* Regenerate the full name of an interrupt event and update its priority.
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*/
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static void
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intr_event_update(struct intr_event *ie)
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{
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struct intr_handler *ih;
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char *last;
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int missed, space;
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/* Start off with no entropy and just the name of the event. */
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mtx_assert(&ie->ie_lock, MA_OWNED);
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strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname));
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ie->ie_flags &= ~IE_ENTROPY;
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missed = 0;
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space = 1;
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/* Run through all the handlers updating values. */
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TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
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if (strlen(ie->ie_fullname) + strlen(ih->ih_name) + 1 <
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sizeof(ie->ie_fullname)) {
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strcat(ie->ie_fullname, " ");
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strcat(ie->ie_fullname, ih->ih_name);
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space = 0;
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} else
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missed++;
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if (ih->ih_flags & IH_ENTROPY)
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ie->ie_flags |= IE_ENTROPY;
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}
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/*
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* If the handler names were too long, add +'s to indicate missing
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* names. If we run out of room and still have +'s to add, change
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* the last character from a + to a *.
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*/
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last = &ie->ie_fullname[sizeof(ie->ie_fullname) - 2];
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while (missed-- > 0) {
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if (strlen(ie->ie_fullname) + 1 == sizeof(ie->ie_fullname)) {
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if (*last == '+') {
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*last = '*';
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break;
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} else
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*last = '+';
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} else if (space) {
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strcat(ie->ie_fullname, " +");
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space = 0;
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} else
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strcat(ie->ie_fullname, "+");
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}
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/*
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* If this event has an ithread, update it's priority and
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* name.
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*/
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if (ie->ie_thread != NULL)
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ithread_update(ie->ie_thread);
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CTR2(KTR_INTR, "%s: updated %s", __func__, ie->ie_fullname);
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}
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int
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intr_event_create(struct intr_event **event, void *source, int flags,
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void (*enable)(void *), const char *fmt, ...)
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{
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struct intr_event *ie;
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va_list ap;
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/* The only valid flag during creation is IE_SOFT. */
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if ((flags & ~IE_SOFT) != 0)
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return (EINVAL);
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ie = malloc(sizeof(struct intr_event), M_ITHREAD, M_WAITOK | M_ZERO);
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ie->ie_source = source;
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ie->ie_enable = enable;
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ie->ie_flags = flags;
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TAILQ_INIT(&ie->ie_handlers);
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mtx_init(&ie->ie_lock, "intr event", NULL, MTX_DEF);
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va_start(ap, fmt);
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vsnprintf(ie->ie_name, sizeof(ie->ie_name), fmt, ap);
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va_end(ap);
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strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname));
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mtx_pool_lock(mtxpool_sleep, &event_list);
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TAILQ_INSERT_TAIL(&event_list, ie, ie_list);
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mtx_pool_unlock(mtxpool_sleep, &event_list);
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if (event != NULL)
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*event = ie;
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CTR2(KTR_INTR, "%s: created %s", __func__, ie->ie_name);
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return (0);
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}
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int
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intr_event_destroy(struct intr_event *ie)
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{
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mtx_lock(&ie->ie_lock);
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if (!TAILQ_EMPTY(&ie->ie_handlers)) {
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mtx_unlock(&ie->ie_lock);
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return (EBUSY);
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}
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mtx_pool_lock(mtxpool_sleep, &event_list);
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TAILQ_REMOVE(&event_list, ie, ie_list);
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mtx_pool_unlock(mtxpool_sleep, &event_list);
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#ifndef notyet
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if (ie->ie_thread != NULL) {
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ithread_destroy(ie->ie_thread);
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ie->ie_thread = NULL;
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}
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#endif
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mtx_unlock(&ie->ie_lock);
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mtx_destroy(&ie->ie_lock);
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free(ie, M_ITHREAD);
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return (0);
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}
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static struct intr_thread *
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ithread_create(const char *name)
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{
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struct intr_thread *ithd;
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struct thread *td;
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struct proc *p;
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int error;
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ithd = malloc(sizeof(struct intr_thread), M_ITHREAD, M_WAITOK | M_ZERO);
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error = kthread_create(ithread_loop, ithd, &p, RFSTOPPED | RFHIGHPID,
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0, "%s", name);
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if (error)
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panic("kthread_create() failed with %d", error);
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td = FIRST_THREAD_IN_PROC(p); /* XXXKSE */
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mtx_lock_spin(&sched_lock);
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td->td_ksegrp->kg_pri_class = PRI_ITHD;
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TD_SET_IWAIT(td);
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mtx_unlock_spin(&sched_lock);
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td->td_pflags |= TDP_ITHREAD;
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ithd->it_thread = td;
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CTR2(KTR_INTR, "%s: created %s", __func__, name);
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return (ithd);
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}
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static void
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ithread_destroy(struct intr_thread *ithread)
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{
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struct thread *td;
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CTR2(KTR_INTR, "%s: killing %s", __func__, ithread->it_event->ie_name);
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td = ithread->it_thread;
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mtx_lock_spin(&sched_lock);
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ithread->it_flags |= IT_DEAD;
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if (TD_AWAITING_INTR(td)) {
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TD_CLR_IWAIT(td);
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setrunqueue(td, SRQ_INTR);
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}
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mtx_unlock_spin(&sched_lock);
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}
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int
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intr_event_add_handler(struct intr_event *ie, const char *name,
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driver_intr_t handler, void *arg, u_char pri, enum intr_type flags,
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void **cookiep)
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{
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struct intr_handler *ih, *temp_ih;
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struct intr_thread *it;
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if (ie == NULL || name == NULL || handler == NULL)
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return (EINVAL);
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/* Allocate and populate an interrupt handler structure. */
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ih = malloc(sizeof(struct intr_handler), M_ITHREAD, M_WAITOK | M_ZERO);
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ih->ih_handler = handler;
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ih->ih_argument = arg;
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ih->ih_name = name;
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ih->ih_event = ie;
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ih->ih_pri = pri;
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if (flags & INTR_FAST)
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ih->ih_flags = IH_FAST;
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else if (flags & INTR_EXCL)
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ih->ih_flags = IH_EXCLUSIVE;
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if (flags & INTR_MPSAFE)
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ih->ih_flags |= IH_MPSAFE;
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if (flags & INTR_ENTROPY)
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ih->ih_flags |= IH_ENTROPY;
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/* We can only have one exclusive handler in a event. */
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mtx_lock(&ie->ie_lock);
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if (!TAILQ_EMPTY(&ie->ie_handlers)) {
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if ((flags & INTR_EXCL) ||
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(TAILQ_FIRST(&ie->ie_handlers)->ih_flags & IH_EXCLUSIVE)) {
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mtx_unlock(&ie->ie_lock);
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free(ih, M_ITHREAD);
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return (EINVAL);
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}
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}
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/* Add the new handler to the event in priority order. */
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TAILQ_FOREACH(temp_ih, &ie->ie_handlers, ih_next) {
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if (temp_ih->ih_pri > ih->ih_pri)
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break;
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}
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if (temp_ih == NULL)
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TAILQ_INSERT_TAIL(&ie->ie_handlers, ih, ih_next);
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else
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TAILQ_INSERT_BEFORE(temp_ih, ih, ih_next);
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intr_event_update(ie);
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/* Create a thread if we need one. */
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while (ie->ie_thread == NULL && !(flags & INTR_FAST)) {
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if (ie->ie_flags & IE_ADDING_THREAD)
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msleep(ie, &ie->ie_lock, 0, "ithread", 0);
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else {
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ie->ie_flags |= IE_ADDING_THREAD;
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mtx_unlock(&ie->ie_lock);
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it = ithread_create("intr: newborn");
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mtx_lock(&ie->ie_lock);
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ie->ie_flags &= ~IE_ADDING_THREAD;
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ie->ie_thread = it;
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it->it_event = ie;
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ithread_update(it);
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wakeup(ie);
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}
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}
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CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name,
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ie->ie_name);
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mtx_unlock(&ie->ie_lock);
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if (cookiep != NULL)
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*cookiep = ih;
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return (0);
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}
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int
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intr_event_remove_handler(void *cookie)
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{
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struct intr_handler *handler = (struct intr_handler *)cookie;
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struct intr_event *ie;
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#ifdef INVARIANTS
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struct intr_handler *ih;
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#endif
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#ifdef notyet
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int dead;
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#endif
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if (handler == NULL)
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return (EINVAL);
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ie = handler->ih_event;
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KASSERT(ie != NULL,
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("interrupt handler \"%s\" has a NULL interrupt event",
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handler->ih_name));
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mtx_lock(&ie->ie_lock);
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CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name,
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ie->ie_name);
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#ifdef INVARIANTS
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TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next)
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if (ih == handler)
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goto ok;
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mtx_unlock(&ie->ie_lock);
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panic("interrupt handler \"%s\" not found in interrupt event \"%s\"",
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ih->ih_name, ie->ie_name);
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ok:
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#endif
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/*
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* If there is no ithread, then just remove the handler and return.
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* XXX: Note that an INTR_FAST handler might be running on another
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* CPU!
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*/
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if (ie->ie_thread == NULL) {
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TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next);
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mtx_unlock(&ie->ie_lock);
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free(handler, M_ITHREAD);
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return (0);
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}
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/*
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* If the interrupt thread is already running, then just mark this
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* handler as being dead and let the ithread do the actual removal.
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*
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* During a cold boot while cold is set, msleep() does not sleep,
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* so we have to remove the handler here rather than letting the
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* thread do it.
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*/
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mtx_lock_spin(&sched_lock);
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if (!TD_AWAITING_INTR(ie->ie_thread->it_thread) && !cold) {
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handler->ih_flags |= IH_DEAD;
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/*
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* Ensure that the thread will process the handler list
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* again and remove this handler if it has already passed
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* it on the list.
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*/
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ie->ie_thread->it_need = 1;
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} else
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TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next);
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mtx_unlock_spin(&sched_lock);
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while (handler->ih_flags & IH_DEAD)
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msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0);
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intr_event_update(ie);
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#ifdef notyet
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/*
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* XXX: This could be bad in the case of ppbus(8). Also, I think
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* this could lead to races of stale data when servicing an
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* interrupt.
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*/
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dead = 1;
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TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
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if (!(ih->ih_flags & IH_FAST)) {
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dead = 0;
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break;
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}
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}
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if (dead) {
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ithread_destroy(ie->ie_thread);
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ie->ie_thread = NULL;
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}
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#endif
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mtx_unlock(&ie->ie_lock);
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free(handler, M_ITHREAD);
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return (0);
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}
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int
|
|
intr_event_schedule_thread(struct intr_event *ie)
|
|
{
|
|
struct intr_entropy entropy;
|
|
struct intr_thread *it;
|
|
struct thread *td;
|
|
struct thread *ctd;
|
|
struct proc *p;
|
|
|
|
/*
|
|
* If no ithread or no handlers, then we have a stray interrupt.
|
|
*/
|
|
if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers) ||
|
|
ie->ie_thread == NULL)
|
|
return (EINVAL);
|
|
|
|
ctd = curthread;
|
|
it = ie->ie_thread;
|
|
td = it->it_thread;
|
|
p = td->td_proc;
|
|
|
|
/*
|
|
* If any of the handlers for this ithread claim to be good
|
|
* sources of entropy, then gather some.
|
|
*/
|
|
if (harvest.interrupt && ie->ie_flags & IE_ENTROPY) {
|
|
CTR3(KTR_INTR, "%s: pid %d (%s) gathering entropy", __func__,
|
|
p->p_pid, p->p_comm);
|
|
entropy.event = (uintptr_t)ie;
|
|
entropy.td = ctd;
|
|
random_harvest(&entropy, sizeof(entropy), 2, 0,
|
|
RANDOM_INTERRUPT);
|
|
}
|
|
|
|
KASSERT(p != NULL, ("ithread %s has no process", ie->ie_name));
|
|
|
|
/*
|
|
* Set it_need to tell the thread to keep running if it is already
|
|
* running. Then, grab sched_lock and see if we actually need to
|
|
* put this thread on the runqueue.
|
|
*/
|
|
it->it_need = 1;
|
|
mtx_lock_spin(&sched_lock);
|
|
if (TD_AWAITING_INTR(td)) {
|
|
CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, p->p_pid,
|
|
p->p_comm);
|
|
TD_CLR_IWAIT(td);
|
|
setrunqueue(td, SRQ_INTR);
|
|
} else {
|
|
CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d",
|
|
__func__, p->p_pid, p->p_comm, it->it_need, td->td_state);
|
|
}
|
|
mtx_unlock_spin(&sched_lock);
|
|
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Add a software interrupt handler to a specified event. If a given event
|
|
* is not specified, then a new event is created.
|
|
*/
|
|
int
|
|
swi_add(struct intr_event **eventp, const char *name, driver_intr_t handler,
|
|
void *arg, int pri, enum intr_type flags, void **cookiep)
|
|
{
|
|
struct intr_event *ie;
|
|
int error;
|
|
|
|
if (flags & (INTR_FAST | INTR_ENTROPY))
|
|
return (EINVAL);
|
|
|
|
ie = (eventp != NULL) ? *eventp : NULL;
|
|
|
|
if (ie != NULL) {
|
|
if (!(ie->ie_flags & IE_SOFT))
|
|
return (EINVAL);
|
|
} else {
|
|
error = intr_event_create(&ie, NULL, IE_SOFT, NULL,
|
|
"swi%d:", pri);
|
|
if (error)
|
|
return (error);
|
|
if (eventp != NULL)
|
|
*eventp = ie;
|
|
}
|
|
return (intr_event_add_handler(ie, name, handler, arg,
|
|
(pri * RQ_PPQ) + PI_SOFT, flags, cookiep));
|
|
/* XXKSE.. think of a better way to get separate queues */
|
|
}
|
|
|
|
/*
|
|
* Schedule a software interrupt thread.
|
|
*/
|
|
void
|
|
swi_sched(void *cookie, int flags)
|
|
{
|
|
struct intr_handler *ih = (struct intr_handler *)cookie;
|
|
struct intr_event *ie = ih->ih_event;
|
|
int error;
|
|
|
|
PCPU_LAZY_INC(cnt.v_intr);
|
|
|
|
CTR3(KTR_INTR, "swi_sched: %s %s need=%d", ie->ie_name, ih->ih_name,
|
|
ih->ih_need);
|
|
|
|
/*
|
|
* Set ih_need for this handler so that if the ithread is already
|
|
* running it will execute this handler on the next pass. Otherwise,
|
|
* it will execute it the next time it runs.
|
|
*/
|
|
atomic_store_rel_int(&ih->ih_need, 1);
|
|
if (!(flags & SWI_DELAY)) {
|
|
error = intr_event_schedule_thread(ie);
|
|
KASSERT(error == 0, ("stray software interrupt"));
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Remove a software interrupt handler. Currently this code does not
|
|
* remove the associated interrupt event if it becomes empty. Calling code
|
|
* may do so manually via intr_event_destroy(), but that's not really
|
|
* an optimal interface.
|
|
*/
|
|
int
|
|
swi_remove(void *cookie)
|
|
{
|
|
|
|
return (intr_event_remove_handler(cookie));
|
|
}
|
|
|
|
static void
|
|
ithread_execute_handlers(struct proc *p, struct intr_event *ie)
|
|
{
|
|
struct intr_handler *ih, *ihn;
|
|
|
|
/* Interrupt handlers should not sleep. */
|
|
if (!(ie->ie_flags & IE_SOFT))
|
|
THREAD_NO_SLEEPING();
|
|
TAILQ_FOREACH_SAFE(ih, &ie->ie_handlers, ih_next, ihn) {
|
|
|
|
/*
|
|
* If this handler is marked for death, remove it from
|
|
* the list of handlers and wake up the sleeper.
|
|
*/
|
|
if (ih->ih_flags & IH_DEAD) {
|
|
mtx_lock(&ie->ie_lock);
|
|
TAILQ_REMOVE(&ie->ie_handlers, ih, ih_next);
|
|
ih->ih_flags &= ~IH_DEAD;
|
|
wakeup(ih);
|
|
mtx_unlock(&ie->ie_lock);
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* For software interrupt threads, we only execute
|
|
* handlers that have their need flag set. Hardware
|
|
* interrupt threads always invoke all of their handlers.
|
|
*/
|
|
if (ie->ie_flags & IE_SOFT) {
|
|
if (!ih->ih_need)
|
|
continue;
|
|
else
|
|
atomic_store_rel_int(&ih->ih_need, 0);
|
|
}
|
|
|
|
/* Fast handlers are handled in primary interrupt context. */
|
|
if (ih->ih_flags & IH_FAST)
|
|
continue;
|
|
|
|
/* Execute this handler. */
|
|
CTR6(KTR_INTR, "%s: pid %d exec %p(%p) for %s flg=%x",
|
|
__func__, p->p_pid, (void *)ih->ih_handler, ih->ih_argument,
|
|
ih->ih_name, ih->ih_flags);
|
|
|
|
if (!(ih->ih_flags & IH_MPSAFE))
|
|
mtx_lock(&Giant);
|
|
ih->ih_handler(ih->ih_argument);
|
|
if (!(ih->ih_flags & IH_MPSAFE))
|
|
mtx_unlock(&Giant);
|
|
}
|
|
if (!(ie->ie_flags & IE_SOFT))
|
|
THREAD_SLEEPING_OK();
|
|
|
|
/*
|
|
* Interrupt storm handling:
|
|
*
|
|
* If this interrupt source is currently storming, then throttle
|
|
* it to only fire the handler once per clock tick.
|
|
*
|
|
* If this interrupt source is not currently storming, but the
|
|
* number of back to back interrupts exceeds the storm threshold,
|
|
* then enter storming mode.
|
|
*/
|
|
if (intr_storm_threshold != 0 && ie->ie_count >= intr_storm_threshold) {
|
|
if (ie->ie_warned == 0) {
|
|
printf(
|
|
"Interrupt storm detected on \"%s\"; throttling interrupt source\n",
|
|
ie->ie_name);
|
|
ie->ie_warned = 1;
|
|
}
|
|
tsleep(&ie->ie_count, 0, "istorm", 1);
|
|
} else
|
|
ie->ie_count++;
|
|
|
|
/*
|
|
* Now that all the handlers have had a chance to run, reenable
|
|
* the interrupt source.
|
|
*/
|
|
if (ie->ie_enable != NULL)
|
|
ie->ie_enable(ie->ie_source);
|
|
}
|
|
|
|
/*
|
|
* This is the main code for interrupt threads.
|
|
*/
|
|
static void
|
|
ithread_loop(void *arg)
|
|
{
|
|
struct intr_thread *ithd;
|
|
struct intr_event *ie;
|
|
struct thread *td;
|
|
struct proc *p;
|
|
|
|
td = curthread;
|
|
p = td->td_proc;
|
|
ithd = (struct intr_thread *)arg;
|
|
KASSERT(ithd->it_thread == td,
|
|
("%s: ithread and proc linkage out of sync", __func__));
|
|
ie = ithd->it_event;
|
|
ie->ie_count = 0;
|
|
|
|
/*
|
|
* As long as we have interrupts outstanding, go through the
|
|
* list of handlers, giving each one a go at it.
|
|
*/
|
|
for (;;) {
|
|
/*
|
|
* If we are an orphaned thread, then just die.
|
|
*/
|
|
if (ithd->it_flags & IT_DEAD) {
|
|
CTR3(KTR_INTR, "%s: pid %d (%s) exiting", __func__,
|
|
p->p_pid, p->p_comm);
|
|
free(ithd, M_ITHREAD);
|
|
kthread_exit(0);
|
|
}
|
|
|
|
/*
|
|
* Service interrupts. If another interrupt arrives while
|
|
* we are running, it will set it_need to note that we
|
|
* should make another pass.
|
|
*/
|
|
while (ithd->it_need) {
|
|
/*
|
|
* This might need a full read and write barrier
|
|
* to make sure that this write posts before any
|
|
* of the memory or device accesses in the
|
|
* handlers.
|
|
*/
|
|
atomic_store_rel_int(&ithd->it_need, 0);
|
|
ithread_execute_handlers(p, ie);
|
|
}
|
|
WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread");
|
|
mtx_assert(&Giant, MA_NOTOWNED);
|
|
|
|
/*
|
|
* 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_lock_spin(&sched_lock);
|
|
if (!ithd->it_need && !(ithd->it_flags & IT_DEAD)) {
|
|
TD_SET_IWAIT(td);
|
|
ie->ie_count = 0;
|
|
mi_switch(SW_VOL, NULL);
|
|
}
|
|
mtx_unlock_spin(&sched_lock);
|
|
}
|
|
}
|
|
|
|
#ifdef DDB
|
|
/*
|
|
* Dump details about an interrupt handler
|
|
*/
|
|
static void
|
|
db_dump_intrhand(struct intr_handler *ih)
|
|
{
|
|
int comma;
|
|
|
|
db_printf("\t%-10s ", ih->ih_name);
|
|
switch (ih->ih_pri) {
|
|
case PI_REALTIME:
|
|
db_printf("CLK ");
|
|
break;
|
|
case PI_AV:
|
|
db_printf("AV ");
|
|
break;
|
|
case PI_TTYHIGH:
|
|
case PI_TTYLOW:
|
|
db_printf("TTY ");
|
|
break;
|
|
case PI_TAPE:
|
|
db_printf("TAPE");
|
|
break;
|
|
case PI_NET:
|
|
db_printf("NET ");
|
|
break;
|
|
case PI_DISK:
|
|
case PI_DISKLOW:
|
|
db_printf("DISK");
|
|
break;
|
|
case PI_DULL:
|
|
db_printf("DULL");
|
|
break;
|
|
default:
|
|
if (ih->ih_pri >= PI_SOFT)
|
|
db_printf("SWI ");
|
|
else
|
|
db_printf("%4u", ih->ih_pri);
|
|
break;
|
|
}
|
|
db_printf(" ");
|
|
db_printsym((uintptr_t)ih->ih_handler, DB_STGY_PROC);
|
|
db_printf("(%p)", ih->ih_argument);
|
|
if (ih->ih_need ||
|
|
(ih->ih_flags & (IH_FAST | IH_EXCLUSIVE | IH_ENTROPY | IH_DEAD |
|
|
IH_MPSAFE)) != 0) {
|
|
db_printf(" {");
|
|
comma = 0;
|
|
if (ih->ih_flags & IH_FAST) {
|
|
db_printf("FAST");
|
|
comma = 1;
|
|
}
|
|
if (ih->ih_flags & IH_EXCLUSIVE) {
|
|
if (comma)
|
|
db_printf(", ");
|
|
db_printf("EXCL");
|
|
comma = 1;
|
|
}
|
|
if (ih->ih_flags & IH_ENTROPY) {
|
|
if (comma)
|
|
db_printf(", ");
|
|
db_printf("ENTROPY");
|
|
comma = 1;
|
|
}
|
|
if (ih->ih_flags & IH_DEAD) {
|
|
if (comma)
|
|
db_printf(", ");
|
|
db_printf("DEAD");
|
|
comma = 1;
|
|
}
|
|
if (ih->ih_flags & IH_MPSAFE) {
|
|
if (comma)
|
|
db_printf(", ");
|
|
db_printf("MPSAFE");
|
|
comma = 1;
|
|
}
|
|
if (ih->ih_need) {
|
|
if (comma)
|
|
db_printf(", ");
|
|
db_printf("NEED");
|
|
}
|
|
db_printf("}");
|
|
}
|
|
db_printf("\n");
|
|
}
|
|
|
|
/*
|
|
* Dump details about a event.
|
|
*/
|
|
void
|
|
db_dump_intr_event(struct intr_event *ie, int handlers)
|
|
{
|
|
struct intr_handler *ih;
|
|
struct intr_thread *it;
|
|
int comma;
|
|
|
|
db_printf("%s ", ie->ie_fullname);
|
|
it = ie->ie_thread;
|
|
if (it != NULL)
|
|
db_printf("(pid %d)", it->it_thread->td_proc->p_pid);
|
|
else
|
|
db_printf("(no thread)");
|
|
if ((ie->ie_flags & (IE_SOFT | IE_ENTROPY | IE_ADDING_THREAD)) != 0 ||
|
|
(it != NULL && it->it_need)) {
|
|
db_printf(" {");
|
|
comma = 0;
|
|
if (ie->ie_flags & IE_SOFT) {
|
|
db_printf("SOFT");
|
|
comma = 1;
|
|
}
|
|
if (ie->ie_flags & IE_ENTROPY) {
|
|
if (comma)
|
|
db_printf(", ");
|
|
db_printf("ENTROPY");
|
|
comma = 1;
|
|
}
|
|
if (ie->ie_flags & IE_ADDING_THREAD) {
|
|
if (comma)
|
|
db_printf(", ");
|
|
db_printf("ADDING_THREAD");
|
|
comma = 1;
|
|
}
|
|
if (it != NULL && it->it_need) {
|
|
if (comma)
|
|
db_printf(", ");
|
|
db_printf("NEED");
|
|
}
|
|
db_printf("}");
|
|
}
|
|
db_printf("\n");
|
|
|
|
if (handlers)
|
|
TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next)
|
|
db_dump_intrhand(ih);
|
|
}
|
|
|
|
/*
|
|
* Dump data about interrupt handlers
|
|
*/
|
|
DB_SHOW_COMMAND(intr, db_show_intr)
|
|
{
|
|
struct intr_event *ie;
|
|
int quit, all, verbose;
|
|
|
|
quit = 0;
|
|
verbose = index(modif, 'v') != NULL;
|
|
all = index(modif, 'a') != NULL;
|
|
db_setup_paging(db_simple_pager, &quit, db_lines_per_page);
|
|
TAILQ_FOREACH(ie, &event_list, ie_list) {
|
|
if (!all && TAILQ_EMPTY(&ie->ie_handlers))
|
|
continue;
|
|
db_dump_intr_event(ie, verbose);
|
|
}
|
|
}
|
|
#endif /* DDB */
|
|
|
|
/*
|
|
* Start standard software interrupt threads
|
|
*/
|
|
static void
|
|
start_softintr(void *dummy)
|
|
{
|
|
struct proc *p;
|
|
|
|
if (swi_add(&clk_intr_event, "clock", softclock, NULL, SWI_CLOCK,
|
|
INTR_MPSAFE, &softclock_ih) ||
|
|
swi_add(NULL, "vm", swi_vm, NULL, SWI_VM, INTR_MPSAFE, &vm_ih))
|
|
panic("died while creating standard software ithreads");
|
|
|
|
p = clk_intr_event->ie_thread->it_thread->td_proc;
|
|
PROC_LOCK(p);
|
|
p->p_flag |= P_NOLOAD;
|
|
PROC_UNLOCK(p);
|
|
}
|
|
SYSINIT(start_softintr, SI_SUB_SOFTINTR, SI_ORDER_FIRST, start_softintr, NULL)
|
|
|
|
/*
|
|
* Sysctls used by systat and others: hw.intrnames and hw.intrcnt.
|
|
* The data for this machine dependent, and the declarations are in machine
|
|
* dependent code. The layout of intrnames and intrcnt however is machine
|
|
* independent.
|
|
*
|
|
* We do not know the length of intrcnt and intrnames at compile time, so
|
|
* calculate things at run time.
|
|
*/
|
|
static int
|
|
sysctl_intrnames(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
return (sysctl_handle_opaque(oidp, intrnames, eintrnames - intrnames,
|
|
req));
|
|
}
|
|
|
|
SYSCTL_PROC(_hw, OID_AUTO, intrnames, CTLTYPE_OPAQUE | CTLFLAG_RD,
|
|
NULL, 0, sysctl_intrnames, "", "Interrupt Names");
|
|
|
|
static int
|
|
sysctl_intrcnt(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
return (sysctl_handle_opaque(oidp, intrcnt,
|
|
(char *)eintrcnt - (char *)intrcnt, req));
|
|
}
|
|
|
|
SYSCTL_PROC(_hw, OID_AUTO, intrcnt, CTLTYPE_OPAQUE | CTLFLAG_RD,
|
|
NULL, 0, sysctl_intrcnt, "", "Interrupt Counts");
|
|
|
|
#ifdef DDB
|
|
/*
|
|
* DDB command to dump the interrupt statistics.
|
|
*/
|
|
DB_SHOW_COMMAND(intrcnt, db_show_intrcnt)
|
|
{
|
|
u_long *i;
|
|
char *cp;
|
|
int quit;
|
|
|
|
cp = intrnames;
|
|
db_setup_paging(db_simple_pager, &quit, db_lines_per_page);
|
|
for (i = intrcnt, quit = 0; i != eintrcnt && !quit; i++) {
|
|
if (*cp == '\0')
|
|
break;
|
|
if (*i != 0)
|
|
db_printf("%s\t%lu\n", cp, *i);
|
|
cp += strlen(cp) + 1;
|
|
}
|
|
}
|
|
#endif
|