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freebsd-skq/sys/kern/kern_intr.c
Conrad Meyer 29dfb631d8 Extend cpuset_get/setaffinity() APIs 
Add IRQ placement-only and ithread-only API variants. intr_event_bind
has been extended with sibling methods, as it has many more callsites in
existing code.

Reviewed by:	kib@, adrian@ (earlier version)
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D10586
2017-05-03 18:41:08 +00:00

2009 lines
50 KiB
C
Raw Blame History

/*-
* 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 "opt_kstack_usage_prof.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;
SYSCTL_INT(_hw, OID_AUTO, intr_storm_threshold, CTLFLAG_RWTUN,
&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 *, int),
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. Using a cpu id of NOCPU unbinds
* the interrupt event.
*/
static int
_intr_event_bind(struct intr_event *ie, int cpu, bool bindirq, bool bindithread)
{
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.
*/
if (bindithread) {
mtx_lock(&ie->ie_lock);
if (ie->ie_thread != NULL) {
id = ie->ie_thread->it_thread->td_tid;
mtx_unlock(&ie->ie_lock);
error = cpuset_setithread(id, cpu);
if (error)
return (error);
} else
mtx_unlock(&ie->ie_lock);
}
if (bindirq)
error = ie->ie_assign_cpu(ie->ie_source, cpu);
if (error) {
if (bindithread) {
mtx_lock(&ie->ie_lock);
if (ie->ie_thread != NULL) {
cpu = ie->ie_cpu;
id = ie->ie_thread->it_thread->td_tid;
mtx_unlock(&ie->ie_lock);
(void)cpuset_setithread(id, cpu);
} else
mtx_unlock(&ie->ie_lock);
}
return (error);
}
if (bindirq) {
mtx_lock(&ie->ie_lock);
ie->ie_cpu = cpu;
mtx_unlock(&ie->ie_lock);
}
return (error);
}
/*
* Bind an interrupt event to the specified CPU. For supported platforms, any
* associated ithreads as well as the primary interrupt context will be bound
* to the specificed CPU.
*/
int
intr_event_bind(struct intr_event *ie, int cpu)
{
return (_intr_event_bind(ie, cpu, true, true));
}
/*
* Bind an interrupt event to the specified CPU, but do not bind associated
* ithreads.
*/
int
intr_event_bind_irqonly(struct intr_event *ie, int cpu)
{
return (_intr_event_bind(ie, cpu, true, false));
}
/*
* Bind an interrupt event's ithread to the specified CPU.
*/
int
intr_event_bind_ithread(struct intr_event *ie, int cpu)
{
return (_intr_event_bind(ie, cpu, false, true));
}
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, int mode, void *m)
{
struct intr_event *ie;
cpuset_t *mask;
int cpu, 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 = n;
}
}
ie = intr_lookup(irq);
if (ie == NULL)
return (ESRCH);
switch (mode) {
case CPU_WHICH_IRQ:
return (intr_event_bind(ie, cpu));
case CPU_WHICH_INTRHANDLER:
return (intr_event_bind_irqonly(ie, cpu));
case CPU_WHICH_ITHREAD:
return (intr_event_bind_ithread(ie, cpu));
default:
return (EINVAL);
}
}
int
intr_getaffinity(int irq, int mode, void *m)
{
struct intr_event *ie;
struct thread *td;
struct proc *p;
cpuset_t *mask;
lwpid_t id;
int error;
mask = m;
ie = intr_lookup(irq);
if (ie == NULL)
return (ESRCH);
error = 0;
CPU_ZERO(mask);
switch (mode) {
case CPU_WHICH_IRQ:
case CPU_WHICH_INTRHANDLER:
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);
break;
case CPU_WHICH_ITHREAD:
mtx_lock(&ie->ie_lock);
if (ie->ie_thread == NULL) {
mtx_unlock(&ie->ie_lock);
CPU_COPY(cpuset_root, mask);
} else {
id = ie->ie_thread->it_thread->td_tid;
mtx_unlock(&ie->ie_lock);
error = cpuset_which(CPU_WHICH_TID, id, &p, &td, NULL);
if (error != 0)
return (error);
CPU_COPY(&td->td_cpuset->cs_mask, mask);
PROC_UNLOCK(p);
}
default:
return (EINVAL);
}
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.
*
* The release part of the following store ensures
* that the update of ih_flags is ordered before the
* it_need setting. See the comment before
* atomic_cmpset_acq(&ithd->it_need, ...) operation in
* the ithread_execute_handlers().
*/
atomic_store_rel_int(&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 (ie->ie_flags & IE_ENTROPY) {
entropy.event = (uintptr_t)ie;
entropy.td = ctd;
random_harvest_queue(&entropy, sizeof(entropy), 2, 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.
*
* Use store_rel to arrange that the store to ih_need in
* swi_sched() is before the store to it_need and prepare for
* transfer of this order to loads in the ithread.
*/
atomic_store_rel_int(&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.
*
* The release part of the following store ensures
* that the update of ih_flags is ordered before the
* it_need setting. See the comment before
* atomic_cmpset_acq(&ithd->it_need, ...) operation in
* the ithread_execute_handlers().
*/
atomic_store_rel_int(&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 (ie->ie_flags & IE_ENTROPY) {
entropy.event = (uintptr_t)ie;
entropy.td = ctd;
random_harvest_queue(&entropy, sizeof(entropy), 2, 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.
*
* Use store_rel to arrange that the store to ih_need in
* swi_sched() is before the store to it_need and prepare for
* transfer of this order to loads in the ithread.
*/
atomic_store_rel_int(&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, int 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 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);
return (error);
}
/*
* 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;
struct intr_entropy entropy;
int error;
CTR3(KTR_INTR, "swi_sched: %s %s need=%d", ie->ie_name, ih->ih_name,
ih->ih_need);
entropy.event = (uintptr_t)ih;
entropy.td = curthread;
random_harvest_queue(&entropy, sizeof(entropy), 1, RANDOM_SWI);
/*
* 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.
*/
ih->ih_need = 1;
if (!(flags & SWI_DELAY)) {
VM_CNT_INC(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.
*
* ih_need can only be 0 or 1. Failed cmpset below
* means that there is no request to execute handlers,
* so a retry of the cmpset is not needed.
*/
if ((ie->ie_flags & IE_SOFT) != 0 &&
atomic_cmpset_int(&ih->ih_need, 1, 0) == 0)
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);
}
}
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.
*
* The load_acq part of the following cmpset ensures
* that the load of ih_need in ithread_execute_handlers()
* is ordered after the load of it_need here.
*/
while (atomic_cmpset_acq_int(&ithd->it_need, 1, 0) != 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 (atomic_load_acq_int(&ithd->it_need) == 0 &&
(ithd->it_flags & (IT_DEAD | IT_WAIT)) == 0) {
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;
#ifdef KSTACK_USAGE_PROF
intr_prof_stack_use(td, frame);
#endif
/* 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);
KASSERT(error == 0, ("bad stray interrupt"));
}
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.
*
* The load_acq part of the following cmpset ensures
* that the load of ih_need in ithread_execute_handlers()
* is ordered after the load of it_need here.
*/
while (atomic_cmpset_acq_int(&ithd->it_need, 1, 0) != 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 (atomic_load_acq_int(&ithd->it_need) == 0 &&
(ithd->it_flags & (IT_DEAD | IT_WAIT)) == 0) {
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(" ");
if (ih->ih_filter != NULL) {
db_printf("[F]");
db_printsym((uintptr_t)ih->ih_filter, DB_STGY_PROC);
}
if (ih->ih_handler != NULL) {
if (ih->ih_filter != NULL)
db_printf(",");
db_printf("[H]");
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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