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freebsd-dev/sys/kern/kern_intr.c
Alexander Kabaev c9516c94b4 Do not add handler to event handlers list until ithread is created. 
In rare event when fast and ithread interrupts share the same vector
and the fast handler was registered first, we can end up trying to
schedule the ithread that is not created yet. The kernel built with
INVARIANTS then triggers an assertion.

Change the order to create the ithread first and only then add the
handler that needs it to the interrupt event handlers list.

Reviewed by: jhb
2012-08-06 16:37:43 +00:00

1932 lines
48 KiB
C
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/*-
* Copyright (c) 1997, Stefan Esser <se@freebsd.org>
* 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 unmodified, 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.
*
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_ddb.h"
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/cpuset.h>
#include <sys/rtprio.h>
#include <sys/systm.h>
#include <sys/interrupt.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/ktr.h>
#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/random.h>
#include <sys/resourcevar.h>
#include <sys/sched.h>
#include <sys/smp.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <sys/unistd.h>
#include <sys/vmmeter.h>
#include <machine/atomic.h>
#include <machine/cpu.h>
#include <machine/md_var.h>
#include <machine/stdarg.h>
#ifdef DDB
#include <ddb/ddb.h>
#include <ddb/db_sym.h>
#endif
/*
* Describe an interrupt thread. There is one of these per interrupt event.
*/
struct intr_thread {
struct intr_event *it_event;
struct thread *it_thread; /* Kernel thread. */
int it_flags; /* (j) IT_* flags. */
int it_need; /* Needs service. */
};
/* Interrupt thread flags kept in it_flags */
#define IT_DEAD 0x000001 /* Thread is waiting to exit. */
#define IT_WAIT 0x000002 /* Thread is waiting for completion. */
struct intr_entropy {
struct thread *td;
uintptr_t event;
};
struct intr_event *clk_intr_event;
struct intr_event *tty_intr_event;
void *vm_ih;
struct proc *intrproc;
static MALLOC_DEFINE(M_ITHREAD, "ithread", "Interrupt Threads");
static int intr_storm_threshold = 1000;
TUNABLE_INT("hw.intr_storm_threshold", &intr_storm_threshold);
SYSCTL_INT(_hw, OID_AUTO, intr_storm_threshold, CTLFLAG_RW,
&intr_storm_threshold, 0,
"Number of consecutive interrupts before storm protection is enabled");
static TAILQ_HEAD(, intr_event) event_list =
TAILQ_HEAD_INITIALIZER(event_list);
static struct mtx event_lock;
MTX_SYSINIT(intr_event_list, &event_lock, "intr event list", MTX_DEF);
static void intr_event_update(struct intr_event *ie);
#ifdef INTR_FILTER
static int intr_event_schedule_thread(struct intr_event *ie,
struct intr_thread *ithd);
static int intr_filter_loop(struct intr_event *ie,
struct trapframe *frame, struct intr_thread **ithd);
static struct intr_thread *ithread_create(const char *name,
struct intr_handler *ih);
#else
static int intr_event_schedule_thread(struct intr_event *ie);
static struct intr_thread *ithread_create(const char *name);
#endif
static void ithread_destroy(struct intr_thread *ithread);
static void ithread_execute_handlers(struct proc *p,
struct intr_event *ie);
#ifdef INTR_FILTER
static void priv_ithread_execute_handler(struct proc *p,
struct intr_handler *ih);
#endif
static void ithread_loop(void *);
static void ithread_update(struct intr_thread *ithd);
static void start_softintr(void *);
/* Map an interrupt type to an ithread priority. */
u_char
intr_priority(enum intr_type flags)
{
u_char pri;
flags &= (INTR_TYPE_TTY | INTR_TYPE_BIO | INTR_TYPE_NET |
INTR_TYPE_CAM | INTR_TYPE_MISC | INTR_TYPE_CLK | INTR_TYPE_AV);
switch (flags) {
case INTR_TYPE_TTY:
pri = PI_TTY;
break;
case INTR_TYPE_BIO:
pri = PI_DISK;
break;
case INTR_TYPE_NET:
pri = PI_NET;
break;
case INTR_TYPE_CAM:
pri = PI_DISK;
break;
case INTR_TYPE_AV:
pri = PI_AV;
break;
case INTR_TYPE_CLK:
pri = PI_REALTIME;
break;
case INTR_TYPE_MISC:
pri = PI_DULL; /* don't care */
break;
default:
/* We didn't specify an interrupt level. */
panic("intr_priority: no interrupt type in flags");
}
return pri;
}
/*
* Update an ithread based on the associated intr_event.
*/
static void
ithread_update(struct intr_thread *ithd)
{
struct intr_event *ie;
struct thread *td;
u_char pri;
ie = ithd->it_event;
td = ithd->it_thread;
/* Determine the overall priority of this event. */
if (TAILQ_EMPTY(&ie->ie_handlers))
pri = PRI_MAX_ITHD;
else
pri = TAILQ_FIRST(&ie->ie_handlers)->ih_pri;
/* Update name and priority. */
strlcpy(td->td_name, ie->ie_fullname, sizeof(td->td_name));
#ifdef KTR
sched_clear_tdname(td);
#endif
thread_lock(td);
sched_prio(td, pri);
thread_unlock(td);
}
/*
* Regenerate the full name of an interrupt event and update its priority.
*/
static void
intr_event_update(struct intr_event *ie)
{
struct intr_handler *ih;
char *last;
int missed, space;
/* Start off with no entropy and just the name of the event. */
mtx_assert(&ie->ie_lock, MA_OWNED);
strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname));
ie->ie_flags &= ~IE_ENTROPY;
missed = 0;
space = 1;
/* Run through all the handlers updating values. */
TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
if (strlen(ie->ie_fullname) + strlen(ih->ih_name) + 1 <
sizeof(ie->ie_fullname)) {
strcat(ie->ie_fullname, " ");
strcat(ie->ie_fullname, ih->ih_name);
space = 0;
} else
missed++;
if (ih->ih_flags & IH_ENTROPY)
ie->ie_flags |= IE_ENTROPY;
}
/*
* If the handler names were too long, add +'s to indicate missing
* names. If we run out of room and still have +'s to add, change
* the last character from a + to a *.
*/
last = &ie->ie_fullname[sizeof(ie->ie_fullname) - 2];
while (missed-- > 0) {
if (strlen(ie->ie_fullname) + 1 == sizeof(ie->ie_fullname)) {
if (*last == '+') {
*last = '*';
break;
} else
*last = '+';
} else if (space) {
strcat(ie->ie_fullname, " +");
space = 0;
} else
strcat(ie->ie_fullname, "+");
}
/*
* If this event has an ithread, update it's priority and
* name.
*/
if (ie->ie_thread != NULL)
ithread_update(ie->ie_thread);
CTR2(KTR_INTR, "%s: updated %s", __func__, ie->ie_fullname);
}
int
intr_event_create(struct intr_event **event, void *source, int flags, int irq,
void (*pre_ithread)(void *), void (*post_ithread)(void *),
void (*post_filter)(void *), int (*assign_cpu)(void *, u_char),
const char *fmt, ...)
{
struct intr_event *ie;
va_list ap;
/* The only valid flag during creation is IE_SOFT. */
if ((flags & ~IE_SOFT) != 0)
return (EINVAL);
ie = malloc(sizeof(struct intr_event), M_ITHREAD, M_WAITOK | M_ZERO);
ie->ie_source = source;
ie->ie_pre_ithread = pre_ithread;
ie->ie_post_ithread = post_ithread;
ie->ie_post_filter = post_filter;
ie->ie_assign_cpu = assign_cpu;
ie->ie_flags = flags;
ie->ie_irq = irq;
ie->ie_cpu = NOCPU;
TAILQ_INIT(&ie->ie_handlers);
mtx_init(&ie->ie_lock, "intr event", NULL, MTX_DEF);
va_start(ap, fmt);
vsnprintf(ie->ie_name, sizeof(ie->ie_name), fmt, ap);
va_end(ap);
strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname));
mtx_lock(&event_lock);
TAILQ_INSERT_TAIL(&event_list, ie, ie_list);
mtx_unlock(&event_lock);
if (event != NULL)
*event = ie;
CTR2(KTR_INTR, "%s: created %s", __func__, ie->ie_name);
return (0);
}
/*
* Bind an interrupt event to the specified CPU. Note that not all
* platforms support binding an interrupt to a CPU. For those
* platforms this request will fail. For supported platforms, any
* associated ithreads as well as the primary interrupt context will
* be bound to the specificed CPU. Using a cpu id of NOCPU unbinds
* the interrupt event.
*/
int
intr_event_bind(struct intr_event *ie, u_char cpu)
{
cpuset_t mask;
lwpid_t id;
int error;
/* Need a CPU to bind to. */
if (cpu != NOCPU && CPU_ABSENT(cpu))
return (EINVAL);
if (ie->ie_assign_cpu == NULL)
return (EOPNOTSUPP);
error = priv_check(curthread, PRIV_SCHED_CPUSET_INTR);
if (error)
return (error);
/*
* If we have any ithreads try to set their mask first to verify
* permissions, etc.
*/
mtx_lock(&ie->ie_lock);
if (ie->ie_thread != NULL) {
CPU_ZERO(&mask);
if (cpu == NOCPU)
CPU_COPY(cpuset_root, &mask);
else
CPU_SET(cpu, &mask);
id = ie->ie_thread->it_thread->td_tid;
mtx_unlock(&ie->ie_lock);
error = cpuset_setthread(id, &mask);
if (error)
return (error);
} else
mtx_unlock(&ie->ie_lock);
error = ie->ie_assign_cpu(ie->ie_source, cpu);
if (error) {
mtx_lock(&ie->ie_lock);
if (ie->ie_thread != NULL) {
CPU_ZERO(&mask);
if (ie->ie_cpu == NOCPU)
CPU_COPY(cpuset_root, &mask);
else
CPU_SET(cpu, &mask);
id = ie->ie_thread->it_thread->td_tid;
mtx_unlock(&ie->ie_lock);
(void)cpuset_setthread(id, &mask);
} else
mtx_unlock(&ie->ie_lock);
return (error);
}
mtx_lock(&ie->ie_lock);
ie->ie_cpu = cpu;
mtx_unlock(&ie->ie_lock);
return (error);
}
static struct intr_event *
intr_lookup(int irq)
{
struct intr_event *ie;
mtx_lock(&event_lock);
TAILQ_FOREACH(ie, &event_list, ie_list)
if (ie->ie_irq == irq &&
(ie->ie_flags & IE_SOFT) == 0 &&
TAILQ_FIRST(&ie->ie_handlers) != NULL)
break;
mtx_unlock(&event_lock);
return (ie);
}
int
intr_setaffinity(int irq, void *m)
{
struct intr_event *ie;
cpuset_t *mask;
u_char cpu;
int n;
mask = m;
cpu = NOCPU;
/*
* If we're setting all cpus we can unbind. Otherwise make sure
* only one cpu is in the set.
*/
if (CPU_CMP(cpuset_root, mask)) {
for (n = 0; n < CPU_SETSIZE; n++) {
if (!CPU_ISSET(n, mask))
continue;
if (cpu != NOCPU)
return (EINVAL);
cpu = (u_char)n;
}
}
ie = intr_lookup(irq);
if (ie == NULL)
return (ESRCH);
return (intr_event_bind(ie, cpu));
}
int
intr_getaffinity(int irq, void *m)
{
struct intr_event *ie;
cpuset_t *mask;
mask = m;
ie = intr_lookup(irq);
if (ie == NULL)
return (ESRCH);
CPU_ZERO(mask);
mtx_lock(&ie->ie_lock);
if (ie->ie_cpu == NOCPU)
CPU_COPY(cpuset_root, mask);
else
CPU_SET(ie->ie_cpu, mask);
mtx_unlock(&ie->ie_lock);
return (0);
}
int
intr_event_destroy(struct intr_event *ie)
{
mtx_lock(&event_lock);
mtx_lock(&ie->ie_lock);
if (!TAILQ_EMPTY(&ie->ie_handlers)) {
mtx_unlock(&ie->ie_lock);
mtx_unlock(&event_lock);
return (EBUSY);
}
TAILQ_REMOVE(&event_list, ie, ie_list);
#ifndef notyet
if (ie->ie_thread != NULL) {
ithread_destroy(ie->ie_thread);
ie->ie_thread = NULL;
}
#endif
mtx_unlock(&ie->ie_lock);
mtx_unlock(&event_lock);
mtx_destroy(&ie->ie_lock);
free(ie, M_ITHREAD);
return (0);
}
#ifndef INTR_FILTER
static struct intr_thread *
ithread_create(const char *name)
{
struct intr_thread *ithd;
struct thread *td;
int error;
ithd = malloc(sizeof(struct intr_thread), M_ITHREAD, M_WAITOK | M_ZERO);
error = kproc_kthread_add(ithread_loop, ithd, &intrproc,
&td, RFSTOPPED | RFHIGHPID,
0, "intr", "%s", name);
if (error)
panic("kproc_create() failed with %d", error);
thread_lock(td);
sched_class(td, PRI_ITHD);
TD_SET_IWAIT(td);
thread_unlock(td);
td->td_pflags |= TDP_ITHREAD;
ithd->it_thread = td;
CTR2(KTR_INTR, "%s: created %s", __func__, name);
return (ithd);
}
#else
static struct intr_thread *
ithread_create(const char *name, struct intr_handler *ih)
{
struct intr_thread *ithd;
struct thread *td;
int error;
ithd = malloc(sizeof(struct intr_thread), M_ITHREAD, M_WAITOK | M_ZERO);
error = kproc_kthread_add(ithread_loop, ih, &intrproc,
&td, RFSTOPPED | RFHIGHPID,
0, "intr", "%s", name);
if (error)
panic("kproc_create() failed with %d", error);
thread_lock(td);
sched_class(td, PRI_ITHD);
TD_SET_IWAIT(td);
thread_unlock(td);
td->td_pflags |= TDP_ITHREAD;
ithd->it_thread = td;
CTR2(KTR_INTR, "%s: created %s", __func__, name);
return (ithd);
}
#endif
static void
ithread_destroy(struct intr_thread *ithread)
{
struct thread *td;
CTR2(KTR_INTR, "%s: killing %s", __func__, ithread->it_event->ie_name);
td = ithread->it_thread;
thread_lock(td);
ithread->it_flags |= IT_DEAD;
if (TD_AWAITING_INTR(td)) {
TD_CLR_IWAIT(td);
sched_add(td, SRQ_INTR);
}
thread_unlock(td);
}
#ifndef INTR_FILTER
int
intr_event_add_handler(struct intr_event *ie, const char *name,
driver_filter_t filter, driver_intr_t handler, void *arg, u_char pri,
enum intr_type flags, void **cookiep)
{
struct intr_handler *ih, *temp_ih;
struct intr_thread *it;
if (ie == NULL || name == NULL || (handler == NULL && filter == NULL))
return (EINVAL);
/* Allocate and populate an interrupt handler structure. */
ih = malloc(sizeof(struct intr_handler), M_ITHREAD, M_WAITOK | M_ZERO);
ih->ih_filter = filter;
ih->ih_handler = handler;
ih->ih_argument = arg;
strlcpy(ih->ih_name, name, sizeof(ih->ih_name));
ih->ih_event = ie;
ih->ih_pri = pri;
if (flags & INTR_EXCL)
ih->ih_flags = IH_EXCLUSIVE;
if (flags & INTR_MPSAFE)
ih->ih_flags |= IH_MPSAFE;
if (flags & INTR_ENTROPY)
ih->ih_flags |= IH_ENTROPY;
/* We can only have one exclusive handler in a event. */
mtx_lock(&ie->ie_lock);
if (!TAILQ_EMPTY(&ie->ie_handlers)) {
if ((flags & INTR_EXCL) ||
(TAILQ_FIRST(&ie->ie_handlers)->ih_flags & IH_EXCLUSIVE)) {
mtx_unlock(&ie->ie_lock);
free(ih, M_ITHREAD);
return (EINVAL);
}
}
/* Create a thread if we need one. */
while (ie->ie_thread == NULL && handler != NULL) {
if (ie->ie_flags & IE_ADDING_THREAD)
msleep(ie, &ie->ie_lock, 0, "ithread", 0);
else {
ie->ie_flags |= IE_ADDING_THREAD;
mtx_unlock(&ie->ie_lock);
it = ithread_create("intr: newborn");
mtx_lock(&ie->ie_lock);
ie->ie_flags &= ~IE_ADDING_THREAD;
ie->ie_thread = it;
it->it_event = ie;
ithread_update(it);
wakeup(ie);
}
}
/* Add the new handler to the event in priority order. */
TAILQ_FOREACH(temp_ih, &ie->ie_handlers, ih_next) {
if (temp_ih->ih_pri > ih->ih_pri)
break;
}
if (temp_ih == NULL)
TAILQ_INSERT_TAIL(&ie->ie_handlers, ih, ih_next);
else
TAILQ_INSERT_BEFORE(temp_ih, ih, ih_next);
intr_event_update(ie);
CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name,
ie->ie_name);
mtx_unlock(&ie->ie_lock);
if (cookiep != NULL)
*cookiep = ih;
return (0);
}
#else
int
intr_event_add_handler(struct intr_event *ie, const char *name,
driver_filter_t filter, driver_intr_t handler, void *arg, u_char pri,
enum intr_type flags, void **cookiep)
{
struct intr_handler *ih, *temp_ih;
struct intr_thread *it;
if (ie == NULL || name == NULL || (handler == NULL && filter == NULL))
return (EINVAL);
/* Allocate and populate an interrupt handler structure. */
ih = malloc(sizeof(struct intr_handler), M_ITHREAD, M_WAITOK | M_ZERO);
ih->ih_filter = filter;
ih->ih_handler = handler;
ih->ih_argument = arg;
strlcpy(ih->ih_name, name, sizeof(ih->ih_name));
ih->ih_event = ie;
ih->ih_pri = pri;
if (flags & INTR_EXCL)
ih->ih_flags = IH_EXCLUSIVE;
if (flags & INTR_MPSAFE)
ih->ih_flags |= IH_MPSAFE;
if (flags & INTR_ENTROPY)
ih->ih_flags |= IH_ENTROPY;
/* We can only have one exclusive handler in a event. */
mtx_lock(&ie->ie_lock);
if (!TAILQ_EMPTY(&ie->ie_handlers)) {
if ((flags & INTR_EXCL) ||
(TAILQ_FIRST(&ie->ie_handlers)->ih_flags & IH_EXCLUSIVE)) {
mtx_unlock(&ie->ie_lock);
free(ih, M_ITHREAD);
return (EINVAL);
}
}
/* For filtered handlers, create a private ithread to run on. */
if (filter != NULL && handler != NULL) {
mtx_unlock(&ie->ie_lock);
it = ithread_create("intr: newborn", ih);
mtx_lock(&ie->ie_lock);
it->it_event = ie;
ih->ih_thread = it;
ithread_update(it); /* XXX - do we really need this?!?!? */
} else { /* Create the global per-event thread if we need one. */
while (ie->ie_thread == NULL && handler != NULL) {
if (ie->ie_flags & IE_ADDING_THREAD)
msleep(ie, &ie->ie_lock, 0, "ithread", 0);
else {
ie->ie_flags |= IE_ADDING_THREAD;
mtx_unlock(&ie->ie_lock);
it = ithread_create("intr: newborn", ih);
mtx_lock(&ie->ie_lock);
ie->ie_flags &= ~IE_ADDING_THREAD;
ie->ie_thread = it;
it->it_event = ie;
ithread_update(it);
wakeup(ie);
}
}
}
/* Add the new handler to the event in priority order. */
TAILQ_FOREACH(temp_ih, &ie->ie_handlers, ih_next) {
if (temp_ih->ih_pri > ih->ih_pri)
break;
}
if (temp_ih == NULL)
TAILQ_INSERT_TAIL(&ie->ie_handlers, ih, ih_next);
else
TAILQ_INSERT_BEFORE(temp_ih, ih, ih_next);
intr_event_update(ie);
CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name,
ie->ie_name);
mtx_unlock(&ie->ie_lock);
if (cookiep != NULL)
*cookiep = ih;
return (0);
}
#endif
/*
* Append a description preceded by a ':' to the name of the specified
* interrupt handler.
*/
int
intr_event_describe_handler(struct intr_event *ie, void *cookie,
const char *descr)
{
struct intr_handler *ih;
size_t space;
char *start;
mtx_lock(&ie->ie_lock);
#ifdef INVARIANTS
TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
if (ih == cookie)
break;
}
if (ih == NULL) {
mtx_unlock(&ie->ie_lock);
panic("handler %p not found in interrupt event %p", cookie, ie);
}
#endif
ih = cookie;
/*
* Look for an existing description by checking for an
* existing ":". This assumes device names do not include
* colons. If one is found, prepare to insert the new
* description at that point. If one is not found, find the
* end of the name to use as the insertion point.
*/
start = strchr(ih->ih_name, ':');
if (start == NULL)
start = strchr(ih->ih_name, 0);
/*
* See if there is enough remaining room in the string for the
* description + ":". The "- 1" leaves room for the trailing
* '\0'. The "+ 1" accounts for the colon.
*/
space = sizeof(ih->ih_name) - (start - ih->ih_name) - 1;
if (strlen(descr) + 1 > space) {
mtx_unlock(&ie->ie_lock);
return (ENOSPC);
}
/* Append a colon followed by the description. */
*start = ':';
strcpy(start + 1, descr);
intr_event_update(ie);
mtx_unlock(&ie->ie_lock);
return (0);
}
/*
* Return the ie_source field from the intr_event an intr_handler is
* associated with.
*/
void *
intr_handler_source(void *cookie)
{
struct intr_handler *ih;
struct intr_event *ie;
ih = (struct intr_handler *)cookie;
if (ih == NULL)
return (NULL);
ie = ih->ih_event;
KASSERT(ie != NULL,
("interrupt handler \"%s\" has a NULL interrupt event",
ih->ih_name));
return (ie->ie_source);
}
/*
* Sleep until an ithread finishes executing an interrupt handler.
*
* XXX Doesn't currently handle interrupt filters or fast interrupt
* handlers. This is intended for compatibility with linux drivers
* only. Do not use in BSD code.
*/
void
_intr_drain(int irq)
{
struct intr_event *ie;
struct intr_thread *ithd;
struct thread *td;
ie = intr_lookup(irq);
if (ie == NULL)
return;
if (ie->ie_thread == NULL)
return;
ithd = ie->ie_thread;
td = ithd->it_thread;
/*
* We set the flag and wait for it to be cleared to avoid
* long delays with potentially busy interrupt handlers
* were we to only sample TD_AWAITING_INTR() every tick.
*/
thread_lock(td);
if (!TD_AWAITING_INTR(td)) {
ithd->it_flags |= IT_WAIT;
while (ithd->it_flags & IT_WAIT) {
thread_unlock(td);
pause("idrain", 1);
thread_lock(td);
}
}
thread_unlock(td);
return;
}
#ifndef INTR_FILTER
int
intr_event_remove_handler(void *cookie)
{
struct intr_handler *handler = (struct intr_handler *)cookie;
struct intr_event *ie;
#ifdef INVARIANTS
struct intr_handler *ih;
#endif
#ifdef notyet
int dead;
#endif
if (handler == NULL)
return (EINVAL);
ie = handler->ih_event;
KASSERT(ie != NULL,
("interrupt handler \"%s\" has a NULL interrupt event",
handler->ih_name));
mtx_lock(&ie->ie_lock);
CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name,
ie->ie_name);
#ifdef INVARIANTS
TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next)
if (ih == handler)
goto ok;
mtx_unlock(&ie->ie_lock);
panic("interrupt handler \"%s\" not found in interrupt event \"%s\"",
ih->ih_name, ie->ie_name);
ok:
#endif
/*
* If there is no ithread, then just remove the handler and return.
* XXX: Note that an INTR_FAST handler might be running on another
* CPU!
*/
if (ie->ie_thread == NULL) {
TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next);
mtx_unlock(&ie->ie_lock);
free(handler, M_ITHREAD);
return (0);
}
/*
* If the interrupt thread is already running, then just mark this
* handler as being dead and let the ithread do the actual removal.
*
* During a cold boot while cold is set, msleep() does not sleep,
* so we have to remove the handler here rather than letting the
* thread do it.
*/
thread_lock(ie->ie_thread->it_thread);
if (!TD_AWAITING_INTR(ie->ie_thread->it_thread) && !cold) {
handler->ih_flags |= IH_DEAD;
/*
* Ensure that the thread will process the handler list
* again and remove this handler if it has already passed
* it on the list.
*/
ie->ie_thread->it_need = 1;
} else
TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next);
thread_unlock(ie->ie_thread->it_thread);
while (handler->ih_flags & IH_DEAD)
msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0);
intr_event_update(ie);
#ifdef notyet
/*
* XXX: This could be bad in the case of ppbus(8). Also, I think
* this could lead to races of stale data when servicing an
* interrupt.
*/
dead = 1;
TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
if (!(ih->ih_flags & IH_FAST)) {
dead = 0;
break;
}
}
if (dead) {
ithread_destroy(ie->ie_thread);
ie->ie_thread = NULL;
}
#endif
mtx_unlock(&ie->ie_lock);
free(handler, M_ITHREAD);
return (0);
}
static 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, td->td_name);
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, lock the thread and see if we actually need to
* put it on the runqueue.
*/
it->it_need = 1;
thread_lock(td);
if (TD_AWAITING_INTR(td)) {
CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, p->p_pid,
td->td_name);
TD_CLR_IWAIT(td);
sched_add(td, SRQ_INTR);
} else {
CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d",
__func__, p->p_pid, td->td_name, it->it_need, td->td_state);
}
thread_unlock(td);
return (0);
}
#else
int
intr_event_remove_handler(void *cookie)
{
struct intr_handler *handler = (struct intr_handler *)cookie;
struct intr_event *ie;
struct intr_thread *it;
#ifdef INVARIANTS
struct intr_handler *ih;
#endif
#ifdef notyet
int dead;
#endif
if (handler == NULL)
return (EINVAL);
ie = handler->ih_event;
KASSERT(ie != NULL,
("interrupt handler \"%s\" has a NULL interrupt event",
handler->ih_name));
mtx_lock(&ie->ie_lock);
CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name,
ie->ie_name);
#ifdef INVARIANTS
TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next)
if (ih == handler)
goto ok;
mtx_unlock(&ie->ie_lock);
panic("interrupt handler \"%s\" not found in interrupt event \"%s\"",
ih->ih_name, ie->ie_name);
ok:
#endif
/*
* If there are no ithreads (per event and per handler), then
* just remove the handler and return.
* XXX: Note that an INTR_FAST handler might be running on another CPU!
*/
if (ie->ie_thread == NULL && handler->ih_thread == NULL) {
TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next);
mtx_unlock(&ie->ie_lock);
free(handler, M_ITHREAD);
return (0);
}
/* Private or global ithread? */
it = (handler->ih_thread) ? handler->ih_thread : ie->ie_thread;
/*
* If the interrupt thread is already running, then just mark this
* handler as being dead and let the ithread do the actual removal.
*
* During a cold boot while cold is set, msleep() does not sleep,
* so we have to remove the handler here rather than letting the
* thread do it.
*/
thread_lock(it->it_thread);
if (!TD_AWAITING_INTR(it->it_thread) && !cold) {
handler->ih_flags |= IH_DEAD;
/*
* Ensure that the thread will process the handler list
* again and remove this handler if it has already passed
* it on the list.
*/
it->it_need = 1;
} else
TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next);
thread_unlock(it->it_thread);
while (handler->ih_flags & IH_DEAD)
msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0);
/*
* At this point, the handler has been disconnected from the event,
* so we can kill the private ithread if any.
*/
if (handler->ih_thread) {
ithread_destroy(handler->ih_thread);
handler->ih_thread = NULL;
}
intr_event_update(ie);
#ifdef notyet
/*
* XXX: This could be bad in the case of ppbus(8). Also, I think
* this could lead to races of stale data when servicing an
* interrupt.
*/
dead = 1;
TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
if (handler != NULL) {
dead = 0;
break;
}
}
if (dead) {
ithread_destroy(ie->ie_thread);
ie->ie_thread = NULL;
}
#endif
mtx_unlock(&ie->ie_lock);
free(handler, M_ITHREAD);
return (0);
}
static int
intr_event_schedule_thread(struct intr_event *ie, struct intr_thread *it)
{
struct intr_entropy entropy;
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) || it == NULL)
return (EINVAL);
ctd = curthread;
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, td->td_name);
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, lock the thread and see if we actually need to
* put it on the runqueue.
*/
it->it_need = 1;
thread_lock(td);
if (TD_AWAITING_INTR(td)) {
CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, p->p_pid,
td->td_name);
TD_CLR_IWAIT(td);
sched_add(td, SRQ_INTR);
} else {
CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d",
__func__, p->p_pid, td->td_name, it->it_need, td->td_state);
}
thread_unlock(td);
return (0);
}
#endif
/*
* Allow interrupt event binding for software interrupt handlers -- a no-op,
* since interrupts are generated in software rather than being directed by
* a PIC.
*/
static int
swi_assign_cpu(void *arg, u_char cpu)
{
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 thread *td;
struct intr_event *ie;
int error;
if (flags & 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, 0,
NULL, NULL, NULL, swi_assign_cpu, "swi%d:", pri);
if (error)
return (error);
if (eventp != NULL)
*eventp = ie;
}
error = intr_event_add_handler(ie, name, NULL, handler, arg,
PI_SWI(pri), flags, cookiep);
if (error)
return (error);
if (pri == SWI_CLOCK) {
td = ie->ie_thread->it_thread;
thread_lock(td);
td->td_flags |= TDF_NOLOAD;
thread_unlock(td);
}
return (0);
}
/*
* 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;
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)) {
PCPU_INC(cnt.v_soft);
#ifdef INTR_FILTER
error = intr_event_schedule_thread(ie, ie->ie_thread);
#else
error = intr_event_schedule_thread(ie);
#endif
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));
}
#ifdef INTR_FILTER
static void
priv_ithread_execute_handler(struct proc *p, struct intr_handler *ih)
{
struct intr_event *ie;
ie = ih->ih_event;
/*
* 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);
return;
}
/* 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);
}
#endif
/*
* This is a public function for use by drivers that mux interrupt
* handlers for child devices from their interrupt handler.
*/
void
intr_event_execute_handlers(struct proc *p, struct intr_event *ie)
{
struct intr_handler *ih, *ihn;
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;
}
/* Skip filter only handlers */
if (ih->ih_handler == NULL)
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);
}
/* 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);
}
}
static void
ithread_execute_handlers(struct proc *p, struct intr_event *ie)
{
/* Interrupt handlers should not sleep. */
if (!(ie->ie_flags & IE_SOFT))
THREAD_NO_SLEEPING();
intr_event_execute_handlers(p, ie);
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 &&
!(ie->ie_flags & IE_SOFT)) {
/* Report the message only once every second. */
if (ppsratecheck(&ie->ie_warntm, &ie->ie_warncnt, 1)) {
printf(
"interrupt storm detected on \"%s\"; throttling interrupt source\n",
ie->ie_name);
}
pause("istorm", 1);
} else
ie->ie_count++;
/*
* Now that all the handlers have had a chance to run, reenable
* the interrupt source.
*/
if (ie->ie_post_ithread != NULL)
ie->ie_post_ithread(ie->ie_source);
}
#ifndef INTR_FILTER
/*
* 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;
int wake;
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;
wake = 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, td->td_name);
free(ithd, M_ITHREAD);
kthread_exit();
}
/*
* 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.
*/
thread_lock(td);
if (!ithd->it_need && !(ithd->it_flags & (IT_DEAD | IT_WAIT))) {
TD_SET_IWAIT(td);
ie->ie_count = 0;
mi_switch(SW_VOL | SWT_IWAIT, NULL);
}
if (ithd->it_flags & IT_WAIT) {
wake = 1;
ithd->it_flags &= ~IT_WAIT;
}
thread_unlock(td);
if (wake) {
wakeup(ithd);
wake = 0;
}
}
}
/*
* Main interrupt handling body.
*
* Input:
* o ie: the event connected to this interrupt.
* o frame: some archs (i.e. i386) pass a frame to some.
* handlers as their main argument.
* Return value:
* o 0: everything ok.
* o EINVAL: stray interrupt.
*/
int
intr_event_handle(struct intr_event *ie, struct trapframe *frame)
{
struct intr_handler *ih;
struct trapframe *oldframe;
struct thread *td;
int error, ret, thread;
td = curthread;
/* An interrupt with no event or handlers is a stray interrupt. */
if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers))
return (EINVAL);
/*
* Execute fast interrupt handlers directly.
* To support clock handlers, if a handler registers
* with a NULL argument, then we pass it a pointer to
* a trapframe as its argument.
*/
td->td_intr_nesting_level++;
thread = 0;
ret = 0;
critical_enter();
oldframe = td->td_intr_frame;
td->td_intr_frame = frame;
TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
if (ih->ih_filter == NULL) {
thread = 1;
continue;
}
CTR4(KTR_INTR, "%s: exec %p(%p) for %s", __func__,
ih->ih_filter, ih->ih_argument == NULL ? frame :
ih->ih_argument, ih->ih_name);
if (ih->ih_argument == NULL)
ret = ih->ih_filter(frame);
else
ret = ih->ih_filter(ih->ih_argument);
KASSERT(ret == FILTER_STRAY ||
((ret & (FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) != 0 &&
(ret & ~(FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) == 0),
("%s: incorrect return value %#x from %s", __func__, ret,
ih->ih_name));
/*
* Wrapper handler special handling:
*
* in some particular cases (like pccard and pccbb),
* the _real_ device handler is wrapped in a couple of
* functions - a filter wrapper and an ithread wrapper.
* In this case (and just in this case), the filter wrapper
* could ask the system to schedule the ithread and mask
* the interrupt source if the wrapped handler is composed
* of just an ithread handler.
*
* TODO: write a generic wrapper to avoid people rolling
* their own
*/
if (!thread) {
if (ret == FILTER_SCHEDULE_THREAD)
thread = 1;
}
}
td->td_intr_frame = oldframe;
if (thread) {
if (ie->ie_pre_ithread != NULL)
ie->ie_pre_ithread(ie->ie_source);
} else {
if (ie->ie_post_filter != NULL)
ie->ie_post_filter(ie->ie_source);
}
/* Schedule the ithread if needed. */
if (thread) {
error = intr_event_schedule_thread(ie);
#ifndef XEN
KASSERT(error == 0, ("bad stray interrupt"));
#else
if (error != 0)
log(LOG_WARNING, "bad stray interrupt");
#endif
}
critical_exit();
td->td_intr_nesting_level--;
return (0);
}
#else
/*
* This is the main code for interrupt threads.
*/
static void
ithread_loop(void *arg)
{
struct intr_thread *ithd;
struct intr_handler *ih;
struct intr_event *ie;
struct thread *td;
struct proc *p;
int priv;
int wake;
td = curthread;
p = td->td_proc;
ih = (struct intr_handler *)arg;
priv = (ih->ih_thread != NULL) ? 1 : 0;
ithd = (priv) ? ih->ih_thread : ih->ih_event->ie_thread;
KASSERT(ithd->it_thread == td,
("%s: ithread and proc linkage out of sync", __func__));
ie = ithd->it_event;
ie->ie_count = 0;
wake = 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, td->td_name);
free(ithd, M_ITHREAD);
kthread_exit();
}
/*
* 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);
if (priv)
priv_ithread_execute_handler(p, ih);
else
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.
*/
thread_lock(td);
if (!ithd->it_need && !(ithd->it_flags & (IT_DEAD | IT_WAIT))) {
TD_SET_IWAIT(td);
ie->ie_count = 0;
mi_switch(SW_VOL | SWT_IWAIT, NULL);
}
if (ithd->it_flags & IT_WAIT) {
wake = 1;
ithd->it_flags &= ~IT_WAIT;
}
thread_unlock(td);
if (wake) {
wakeup(ithd);
wake = 0;
}
}
}
/*
* Main loop for interrupt filter.
*
* Some architectures (i386, amd64 and arm) require the optional frame
* parameter, and use it as the main argument for fast handler execution
* when ih_argument == NULL.
*
* Return value:
* o FILTER_STRAY: No filter recognized the event, and no
* filter-less handler is registered on this
* line.
* o FILTER_HANDLED: A filter claimed the event and served it.
* o FILTER_SCHEDULE_THREAD: No filter claimed the event, but there's at
* least one filter-less handler on this line.
* o FILTER_HANDLED |
* FILTER_SCHEDULE_THREAD: A filter claimed the event, and asked for
* scheduling the per-handler ithread.
*
* In case an ithread has to be scheduled, in *ithd there will be a
* pointer to a struct intr_thread containing the thread to be
* scheduled.
*/
static int
intr_filter_loop(struct intr_event *ie, struct trapframe *frame,
struct intr_thread **ithd)
{
struct intr_handler *ih;
void *arg;
int ret, thread_only;
ret = 0;
thread_only = 0;
TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
/*
* Execute fast interrupt handlers directly.
* To support clock handlers, if a handler registers
* with a NULL argument, then we pass it a pointer to
* a trapframe as its argument.
*/
arg = ((ih->ih_argument == NULL) ? frame : ih->ih_argument);
CTR5(KTR_INTR, "%s: exec %p/%p(%p) for %s", __func__,
ih->ih_filter, ih->ih_handler, arg, ih->ih_name);
if (ih->ih_filter != NULL)
ret = ih->ih_filter(arg);
else {
thread_only = 1;
continue;
}
KASSERT(ret == FILTER_STRAY ||
((ret & (FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) != 0 &&
(ret & ~(FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) == 0),
("%s: incorrect return value %#x from %s", __func__, ret,
ih->ih_name));
if (ret & FILTER_STRAY)
continue;
else {
*ithd = ih->ih_thread;
return (ret);
}
}
/*
* No filters handled the interrupt and we have at least
* one handler without a filter. In this case, we schedule
* all of the filter-less handlers to run in the ithread.
*/
if (thread_only) {
*ithd = ie->ie_thread;
return (FILTER_SCHEDULE_THREAD);
}
return (FILTER_STRAY);
}
/*
* Main interrupt handling body.
*
* Input:
* o ie: the event connected to this interrupt.
* o frame: some archs (i.e. i386) pass a frame to some.
* handlers as their main argument.
* Return value:
* o 0: everything ok.
* o EINVAL: stray interrupt.
*/
int
intr_event_handle(struct intr_event *ie, struct trapframe *frame)
{
struct intr_thread *ithd;
struct trapframe *oldframe;
struct thread *td;
int thread;
ithd = NULL;
td = curthread;
if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers))
return (EINVAL);
td->td_intr_nesting_level++;
thread = 0;
critical_enter();
oldframe = td->td_intr_frame;
td->td_intr_frame = frame;
thread = intr_filter_loop(ie, frame, &ithd);
if (thread & FILTER_HANDLED) {
if (ie->ie_post_filter != NULL)
ie->ie_post_filter(ie->ie_source);
} else {
if (ie->ie_pre_ithread != NULL)
ie->ie_pre_ithread(ie->ie_source);
}
td->td_intr_frame = oldframe;
critical_exit();
/* Interrupt storm logic */
if (thread & FILTER_STRAY) {
ie->ie_count++;
if (ie->ie_count < intr_storm_threshold)
printf("Interrupt stray detection not present\n");
}
/* Schedule an ithread if needed. */
if (thread & FILTER_SCHEDULE_THREAD) {
if (intr_event_schedule_thread(ie, ithd) != 0)
panic("%s: impossible stray interrupt", __func__);
}
td->td_intr_nesting_level--;
return (0);
}
#endif
#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_TTY:
db_printf("TTY ");
break;
case PI_NET:
db_printf("NET ");
break;
case PI_DISK:
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_EXCLUSIVE | IH_ENTROPY | IH_DEAD |
IH_MPSAFE)) != 0) {
db_printf(" {");
comma = 0;
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 all, verbose;
verbose = strchr(modif, 'v') != NULL;
all = strchr(modif, 'a') != NULL;
TAILQ_FOREACH(ie, &event_list, ie_list) {
if (!all && TAILQ_EMPTY(&ie->ie_handlers))
continue;
db_dump_intr_event(ie, verbose);
if (db_pager_quit)
break;
}
}
#endif /* DDB */
/*
* Start standard software interrupt threads
*/
static void
start_softintr(void *dummy)
{
if (swi_add(NULL, "vm", swi_vm, NULL, SWI_VM, INTR_MPSAFE, &vm_ih))
panic("died while creating vm swi ithread");
}
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, sintrnames, req));
}
SYSCTL_PROC(_hw, OID_AUTO, intrnames, CTLTYPE_OPAQUE | CTLFLAG_RD,
NULL, 0, sysctl_intrnames, "", "Interrupt Names");
static int
sysctl_intrcnt(SYSCTL_HANDLER_ARGS)
{
#ifdef SCTL_MASK32
uint32_t *intrcnt32;
unsigned i;
int error;
if (req->flags & SCTL_MASK32) {
if (!req->oldptr)
return (sysctl_handle_opaque(oidp, NULL, sintrcnt / 2, req));
intrcnt32 = malloc(sintrcnt / 2, M_TEMP, M_NOWAIT);
if (intrcnt32 == NULL)
return (ENOMEM);
for (i = 0; i < sintrcnt / sizeof (u_long); i++)
intrcnt32[i] = intrcnt[i];
error = sysctl_handle_opaque(oidp, intrcnt32, sintrcnt / 2, req);
free(intrcnt32, M_TEMP);
return (error);
}
#endif
return (sysctl_handle_opaque(oidp, intrcnt, sintrcnt, 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;
u_int j;
cp = intrnames;
j = 0;
for (i = intrcnt; j < (sintrcnt / sizeof(u_long)) && !db_pager_quit;
i++, j++) {
if (*cp == '\0')
break;
if (*i != 0)
db_printf("%s\t%lu\n", cp, *i);
cp += strlen(cp) + 1;
}
}
#endif
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