/*
* 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.
*
* $FreeBSD$
*
*/
#include <sys/param.h>
#include <sys/bus.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/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/random.h>
#include <sys/resourcevar.h>
#include <sys/sysctl.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>
struct int_entropy {
struct proc *proc;
int vector;
};
void *vm_ih;
void *softclock_ih;
struct ithd *clk_ithd;
struct ithd *tty_ithd;
static MALLOC_DEFINE(M_ITHREAD, "ithread", "Interrupt Threads");
static void ithread_update(struct ithd *);
static void ithread_loop(void *);
static void start_softintr(void *);
u_char
ithread_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_TTYLOW;
break;
case INTR_TYPE_BIO:
/*
* XXX We need to refine this. BSD/OS distinguishes
* between tape and disk priorities.
*/
pri = PI_DISK;
break;
case INTR_TYPE_NET:
pri = PI_NET;
break;
case INTR_TYPE_CAM:
pri = PI_DISK; /* XXX or PI_CAM? */
break;
case INTR_TYPE_AV: /* Audio/video */
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("ithread_priority: no interrupt type in flags");
}
return pri;
}
/*
* Regenerate the name (p_comm) and priority for a threaded interrupt thread.
*/
static void
ithread_update(struct ithd *ithd)
{
struct intrhand *ih;
struct thread *td;
struct proc *p;
int entropy;
mtx_assert(&ithd->it_lock, MA_OWNED);
td = ithd->it_td;
if (td == NULL)
return;
p = td->td_proc;
strlcpy(p->p_comm, ithd->it_name, sizeof(p->p_comm));
ih = TAILQ_FIRST(&ithd->it_handlers);
if (ih == NULL) {
mtx_lock_spin(&sched_lock);
td->td_priority = PRI_MAX_ITHD;
td->td_base_pri = PRI_MAX_ITHD;
mtx_unlock_spin(&sched_lock);
ithd->it_flags &= ~IT_ENTROPY;
return;
}
entropy = 0;
mtx_lock_spin(&sched_lock);
td->td_priority = ih->ih_pri;
td->td_base_pri = ih->ih_pri;
mtx_unlock_spin(&sched_lock);
TAILQ_FOREACH(ih, &ithd->it_handlers, ih_next) {
if (strlen(p->p_comm) + strlen(ih->ih_name) + 1 <
sizeof(p->p_comm)) {
strcat(p->p_comm, " ");
strcat(p->p_comm, ih->ih_name);
} else if (strlen(p->p_comm) + 1 == sizeof(p->p_comm)) {
if (p->p_comm[sizeof(p->p_comm) - 2] == '+')
p->p_comm[sizeof(p->p_comm) - 2] = '*';
else
p->p_comm[sizeof(p->p_comm) - 2] = '+';
} else
strcat(p->p_comm, "+");
if (ih->ih_flags & IH_ENTROPY)
entropy++;
}
if (entropy)
ithd->it_flags |= IT_ENTROPY;
else
ithd->it_flags &= ~IT_ENTROPY;
CTR2(KTR_INTR, "%s: updated %s\n", __func__, p->p_comm);
}
int
ithread_create(struct ithd **ithread, int vector, int flags,
void (*disable)(int), void (*enable)(int), const char *fmt, ...)
{
struct ithd *ithd;
struct thread *td;
struct proc *p;
int error;
va_list ap;
/* The only valid flag during creation is IT_SOFT. */
if ((flags & ~IT_SOFT) != 0)
return (EINVAL);
ithd = malloc(sizeof(struct ithd), M_ITHREAD, M_WAITOK | M_ZERO);
ithd->it_vector = vector;
ithd->it_disable = disable;
ithd->it_enable = enable;
ithd->it_flags = flags;
TAILQ_INIT(&ithd->it_handlers);
mtx_init(&ithd->it_lock, "ithread", NULL, MTX_DEF);
va_start(ap, fmt);
vsnprintf(ithd->it_name, sizeof(ithd->it_name), fmt, ap);
va_end(ap);
error = kthread_create(ithread_loop, ithd, &p, RFSTOPPED | RFHIGHPID,
0, "%s", ithd->it_name);
if (error) {
mtx_destroy(&ithd->it_lock);
free(ithd, M_ITHREAD);
return (error);
}
td = FIRST_THREAD_IN_PROC(p); /* XXXKSE */
td->td_ksegrp->kg_pri_class = PRI_ITHD;
td->td_priority = PRI_MAX_ITHD;
TD_SET_IWAIT(td);
ithd->it_td = td;
td->td_ithd = ithd;
if (ithread != NULL)
*ithread = ithd;
CTR2(KTR_INTR, "%s: created %s", __func__, ithd->it_name);
return (0);
}
int
ithread_destroy(struct ithd *ithread)
{
struct thread *td;
struct proc *p;
if (ithread == NULL)
return (EINVAL);
td = ithread->it_td;
p = td->td_proc;
mtx_lock(&ithread->it_lock);
if (!TAILQ_EMPTY(&ithread->it_handlers)) {
mtx_unlock(&ithread->it_lock);
return (EINVAL);
}
ithread->it_flags |= IT_DEAD;
mtx_lock_spin(&sched_lock);
if (TD_AWAITING_INTR(td)) {
TD_CLR_IWAIT(td);
setrunqueue(td);
}
mtx_unlock_spin(&sched_lock);
mtx_unlock(&ithread->it_lock);
CTR2(KTR_INTR, "%s: killing %s", __func__, ithread->it_name);
return (0);
}
int
ithread_add_handler(struct ithd* ithread, const char *name,
driver_intr_t handler, void *arg, u_char pri, enum intr_type flags,
void **cookiep)
{
struct intrhand *ih, *temp_ih;
if (ithread == NULL || name == NULL || handler == NULL)
return (EINVAL);
if ((flags & INTR_FAST) !=0)
flags |= INTR_EXCL;
ih = malloc(sizeof(struct intrhand), M_ITHREAD, M_WAITOK | M_ZERO);
ih->ih_handler = handler;
ih->ih_argument = arg;
ih->ih_name = name;
ih->ih_ithread = ithread;
ih->ih_pri = pri;
if (flags & INTR_FAST)
ih->ih_flags = IH_FAST | IH_EXCLUSIVE;
else 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;
mtx_lock(&ithread->it_lock);
if ((flags & INTR_EXCL) !=0 && !TAILQ_EMPTY(&ithread->it_handlers))
goto fail;
if (!TAILQ_EMPTY(&ithread->it_handlers) &&
(TAILQ_FIRST(&ithread->it_handlers)->ih_flags & IH_EXCLUSIVE) != 0)
goto fail;
TAILQ_FOREACH(temp_ih, &ithread->it_handlers, ih_next)
if (temp_ih->ih_pri > ih->ih_pri)
break;
if (temp_ih == NULL)
TAILQ_INSERT_TAIL(&ithread->it_handlers, ih, ih_next);
else
TAILQ_INSERT_BEFORE(temp_ih, ih, ih_next);
ithread_update(ithread);
mtx_unlock(&ithread->it_lock);
if (cookiep != NULL)
*cookiep = ih;
CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name,
ithread->it_name);
return (0);
fail:
mtx_unlock(&ithread->it_lock);
free(ih, M_ITHREAD);
return (EINVAL);
}
int
ithread_remove_handler(void *cookie)
{
struct intrhand *handler = (struct intrhand *)cookie;
struct ithd *ithread;
#ifdef INVARIANTS
struct intrhand *ih;
#endif
if (handler == NULL)
return (EINVAL);
ithread = handler->ih_ithread;
KASSERT(ithread != NULL,
("interrupt handler \"%s\" has a NULL interrupt thread",
handler->ih_name));
CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name,
ithread->it_name);
mtx_lock(&ithread->it_lock);
#ifdef INVARIANTS
TAILQ_FOREACH(ih, &ithread->it_handlers, ih_next)
if (ih == handler)
goto ok;
mtx_unlock(&ithread->it_lock);
panic("interrupt handler \"%s\" not found in interrupt thread \"%s\"",
ih->ih_name, ithread->it_name);
ok:
#endif
/*
* If the interrupt thread is already running, then just mark this
* handler as being dead and let the ithread do the actual removal.
*/
mtx_lock_spin(&sched_lock);
if (!TD_AWAITING_INTR(ithread->it_td)) {
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.
*/
ithread->it_need = 1;
} else
TAILQ_REMOVE(&ithread->it_handlers, handler, ih_next);
mtx_unlock_spin(&sched_lock);
if ((handler->ih_flags & IH_DEAD) != 0)
msleep(handler, &ithread->it_lock, PUSER, "itrmh", 0);
ithread_update(ithread);
mtx_unlock(&ithread->it_lock);
free(handler, M_ITHREAD);
return (0);
}
int
ithread_schedule(struct ithd *ithread, int do_switch)
{
struct int_entropy entropy;
struct thread *td;
struct thread *ctd;
struct proc *p;
/*
* If no ithread or no handlers, then we have a stray interrupt.
*/
if ((ithread == NULL) || TAILQ_EMPTY(&ithread->it_handlers))
return (EINVAL);
ctd = curthread;
/*
* If any of the handlers for this ithread claim to be good
* sources of entropy, then gather some.
*/
if (harvest.interrupt && ithread->it_flags & IT_ENTROPY) {
entropy.vector = ithread->it_vector;
entropy.proc = ctd->td_proc;
random_harvest(&entropy, sizeof(entropy), 2, 0,
RANDOM_INTERRUPT);
}
td = ithread->it_td;
p = td->td_proc;
KASSERT(p != NULL, ("ithread %s has no process", ithread->it_name));
CTR4(KTR_INTR, "%s: pid %d: (%s) need = %d",
__func__, p->p_pid, p->p_comm, ithread->it_need);
/*
* Set it_need to tell the thread to keep running if it is already
* running. Then, grab sched_lock and see if we actually need to
* put this thread on the runqueue. If so and the do_switch flag is
* true and it is safe to switch, then switch to the ithread
* immediately. Otherwise, set the needresched flag to guarantee
* that this ithread will run before any userland processes.
*/
ithread->it_need = 1;
mtx_lock_spin(&sched_lock);
if (TD_AWAITING_INTR(td)) {
CTR2(KTR_INTR, "%s: setrunqueue %d", __func__, p->p_pid);
TD_CLR_IWAIT(td);
setrunqueue(td);
if (do_switch &&
(ctd->td_critnest == 1) ) {
KASSERT((TD_IS_RUNNING(ctd)),
("ithread_schedule: Bad state for curthread."));
ctd->td_proc->p_stats->p_ru.ru_nivcsw++;
if (ctd->td_kse->ke_flags & KEF_IDLEKSE)
ctd->td_state = TDS_CAN_RUN; /* XXXKSE */
mi_switch();
} else {
curthread->td_kse->ke_flags |= KEF_NEEDRESCHED;
}
} else {
CTR4(KTR_INTR, "%s: pid %d: it_need %d, state %d",
__func__, p->p_pid, ithread->it_need, p->p_state);
}
mtx_unlock_spin(&sched_lock);
return (0);
}
int
swi_add(struct ithd **ithdp, const char *name, driver_intr_t handler,
void *arg, int pri, enum intr_type flags, void **cookiep)
{
struct ithd *ithd;
int error;
if (flags & (INTR_FAST | INTR_ENTROPY))
return (EINVAL);
ithd = (ithdp != NULL) ? *ithdp : NULL;
if (ithd != NULL) {
if ((ithd->it_flags & IT_SOFT) == 0)
return(EINVAL);
} else {
error = ithread_create(&ithd, pri, IT_SOFT, NULL, NULL,
"swi%d:", pri);
if (error)
return (error);
if (ithdp != NULL)
*ithdp = ithd;
}
return (ithread_add_handler(ithd, name, handler, arg,
(pri * RQ_PPQ) + PI_SOFT, flags, cookiep));
}
/*
* Schedule a heavyweight software interrupt process.
*/
void
swi_sched(void *cookie, int flags)
{
struct intrhand *ih = (struct intrhand *)cookie;
struct ithd *it = ih->ih_ithread;
int error;
atomic_add_int(&cnt.v_intr, 1); /* one more global interrupt */
CTR3(KTR_INTR, "swi_sched pid %d(%s) need=%d",
it->it_td->td_proc->p_pid, it->it_td->td_proc->p_comm, it->it_need);
/*
* Set ih_need for this handler so that if the ithread is already
* running it will execute this handler on the next pass. Otherwise,
* it will execute it the next time it runs.
*/
atomic_store_rel_int(&ih->ih_need, 1);
if (!(flags & SWI_DELAY)) {
error = ithread_schedule(it, !cold);
KASSERT(error == 0, ("stray software interrupt"));
}
}
/*
* This is the main code for interrupt threads.
*/
static void
ithread_loop(void *arg)
{
struct ithd *ithd; /* our thread context */
struct intrhand *ih; /* and our interrupt handler chain */
struct thread *td;
struct proc *p;
td = curthread;
p = td->td_proc;
ithd = (struct ithd *)arg; /* point to myself */
KASSERT(ithd->it_td == td && td->td_ithd == ithd,
("%s: ithread and proc linkage out of sync", __func__));
/*
* As long as we have interrupts outstanding, go through the
* list of handlers, giving each one a go at it.
*/
for (;;) {
/*
* If we are an orphaned thread, then just die.
*/
if (ithd->it_flags & IT_DEAD) {
CTR3(KTR_INTR, "%s: pid %d: (%s) exiting", __func__,
p->p_pid, p->p_comm);
td->td_ithd = NULL;
mtx_destroy(&ithd->it_lock);
mtx_lock(&Giant);
free(ithd, M_ITHREAD);
kthread_exit(0);
}
CTR4(KTR_INTR, "%s: pid %d: (%s) need=%d", __func__,
p->p_pid, p->p_comm, ithd->it_need);
while (ithd->it_need) {
/*
* Service interrupts. If another interrupt
* arrives while we are running, they will set
* it_need to denote that we should make
* another pass.
*/
atomic_store_rel_int(&ithd->it_need, 0);
restart:
TAILQ_FOREACH(ih, &ithd->it_handlers, ih_next) {
if (ithd->it_flags & IT_SOFT && !ih->ih_need)
continue;
atomic_store_rel_int(&ih->ih_need, 0);
CTR6(KTR_INTR,
"%s: pid %d ih=%p: %p(%p) flg=%x", __func__,
p->p_pid, (void *)ih,
(void *)ih->ih_handler, ih->ih_argument,
ih->ih_flags);
if ((ih->ih_flags & IH_DEAD) != 0) {
mtx_lock(&ithd->it_lock);
TAILQ_REMOVE(&ithd->it_handlers, ih,
ih_next);
wakeup(ih);
mtx_unlock(&ithd->it_lock);
goto restart;
}
if ((ih->ih_flags & IH_MPSAFE) == 0)
mtx_lock(&Giant);
ih->ih_handler(ih->ih_argument);
if ((ih->ih_flags & IH_MPSAFE) == 0)
mtx_unlock(&Giant);
}
}
/*
* Processed all our interrupts. Now get the sched
* lock. This may take a while and it_need may get
* set again, so we have to check it again.
*/
mtx_assert(&Giant, MA_NOTOWNED);
mtx_lock_spin(&sched_lock);
if (!ithd->it_need) {
/*
* Should we call this earlier in the loop above?
*/
if (ithd->it_enable != NULL)
ithd->it_enable(ithd->it_vector);
TD_SET_IWAIT(td); /* we're idle */
p->p_stats->p_ru.ru_nvcsw++;
CTR2(KTR_INTR, "%s: pid %d: done", __func__, p->p_pid);
mi_switch();
CTR2(KTR_INTR, "%s: pid %d: resumed", __func__, p->p_pid);
}
mtx_unlock_spin(&sched_lock);
}
}
/*
* Start standard software interrupt threads
*/
static void
start_softintr(void *dummy)
{
if (swi_add(&clk_ithd, "clock", softclock, NULL, SWI_CLOCK,
INTR_MPSAFE, &softclock_ih) ||
swi_add(NULL, "vm", swi_vm, NULL, SWI_VM, 0, &vm_ih))
panic("died while creating standard software ithreads");
PROC_LOCK(clk_ithd->it_td->td_proc);
clk_ithd->it_td->td_proc->p_flag |= P_NOLOAD;
PROC_UNLOCK(clk_ithd->it_td->td_proc);
}
SYSINIT(start_softintr, SI_SUB_SOFTINTR, SI_ORDER_FIRST, start_softintr, NULL)
/*
* Sysctls used by systat and others: hw.intrnames and hw.intrcnt.
* The data for this machine dependent, and the declarations are in machine
* dependent code. The layout of intrnames and intrcnt however is machine
* independent.
*
* We do not know the length of intrcnt and intrnames at compile time, so
* calculate things at run time.
*/
static int
sysctl_intrnames(SYSCTL_HANDLER_ARGS)
{
return (sysctl_handle_opaque(oidp, intrnames, eintrnames - intrnames,
req));
}
SYSCTL_PROC(_hw, OID_AUTO, intrnames, CTLTYPE_OPAQUE | CTLFLAG_RD,
NULL, 0, sysctl_intrnames, "", "Interrupt Names");
static int
sysctl_intrcnt(SYSCTL_HANDLER_ARGS)
{
return (sysctl_handle_opaque(oidp, intrcnt,
(char *)eintrcnt - (char *)intrcnt, req));
}
SYSCTL_PROC(_hw, OID_AUTO, intrcnt, CTLTYPE_OPAQUE | CTLFLAG_RD,
NULL, 0, sysctl_intrcnt, "", "Interrupt Counts");
