freebsd-skq/sys/kern/kern_intr.c
jhb 71938e9fcd - Heavyweight interrupt threads on the alpha for device I/O interrupts.
- Make softinterrupts (SWI's) almost completely MI, and divorce them
  completely from the x86 hardware interrupt code.
  - The ihandlers array is now gone.  Instead, there is a MI shandlers array
    that just contains SWI handlers.
  - Most of the former machine/ipl.h files have moved to a new sys/ipl.h.
- Stub out all the spl*() functions on all architectures.

Submitted by:	dfr
2000-10-05 23:09:57 +00:00

378 lines
9.7 KiB
C

/*
* 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/ipl.h>
#include <sys/interrupt.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/ktr.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/unistd.h>
#include <sys/vmmeter.h>
#include <machine/atomic.h>
#include <machine/cpu.h>
#include <machine/mutex.h>
struct swilist {
swihand_t *sl_handler;
struct swilist *sl_next;
};
static struct swilist swilists[NSWI];
u_long softintr_count[NSWI];
static struct proc *softithd;
volatile u_int sdelayed;
volatile u_int spending;
static void start_softintr(void *);
static void intr_soft(void *);
void
register_swi(intr, handler)
int intr;
swihand_t *handler;
{
struct swilist *slp, *slq;
int s;
if (intr < 0 || intr >= NSWI)
panic("register_swi: bad intr %d", intr);
if (handler == swi_generic || handler == swi_null)
panic("register_swi: bad handler %p", (void *)handler);
slp = &swilists[intr];
s = splhigh();
if (shandlers[intr] == swi_null)
shandlers[intr] = handler;
else {
if (slp->sl_next == NULL) {
slp->sl_handler = shandlers[intr];
shandlers[intr] = swi_generic;
}
slq = malloc(sizeof(*slq), M_DEVBUF, M_NOWAIT);
if (slq == NULL)
panic("register_swi: malloc failed");
slq->sl_handler = handler;
slq->sl_next = NULL;
while (slp->sl_next != NULL)
slp = slp->sl_next;
slp->sl_next = slq;
}
splx(s);
}
void
swi_dispatcher(intr)
int intr;
{
struct swilist *slp;
slp = &swilists[intr];
do {
(*slp->sl_handler)();
slp = slp->sl_next;
} while (slp != NULL);
}
void
unregister_swi(intr, handler)
int intr;
swihand_t *handler;
{
struct swilist *slfoundpred, *slp, *slq;
int s;
if (intr < 0 || intr >= NSWI)
panic("unregister_swi: bad intr %d", intr);
if (handler == swi_generic || handler == swi_null)
panic("unregister_swi: bad handler %p", (void *)handler);
slp = &swilists[intr];
s = splhigh();
if (shandlers[intr] == handler)
shandlers[intr] = swi_null;
else if (slp->sl_next != NULL) {
slfoundpred = NULL;
for (slq = slp->sl_next; slq != NULL;
slp = slq, slq = slp->sl_next)
if (slq->sl_handler == handler)
slfoundpred = slp;
slp = &swilists[intr];
if (slfoundpred != NULL) {
slq = slfoundpred->sl_next;
slfoundpred->sl_next = slq->sl_next;
free(slq, M_DEVBUF);
} else if (slp->sl_handler == handler) {
slq = slp->sl_next;
slp->sl_next = slq->sl_next;
slp->sl_handler = slq->sl_handler;
free(slq, M_DEVBUF);
}
if (slp->sl_next == NULL)
shandlers[intr] = slp->sl_handler;
}
splx(s);
}
int
ithread_priority(flags)
int flags;
{
int pri;
switch (flags) {
case INTR_TYPE_TTY: /* keyboard or parallel port */
pri = PI_TTYLOW;
break;
case (INTR_TYPE_TTY | INTR_FAST): /* sio */
pri = PI_TTYHIGH;
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_MISC:
pri = PI_DULL; /* don't care */
break;
/* We didn't specify an interrupt level. */
default:
panic("ithread_priority: no interrupt type in flags");
}
return pri;
}
/*
* Schedule the soft interrupt handler thread.
*/
void
sched_softintr(void)
{
atomic_add_int(&cnt.v_intr, 1); /* one more global interrupt */
/*
* If we don't have an interrupt resource or an interrupt thread for
* this IRQ, log it as a stray interrupt.
*/
if (softithd == NULL)
panic("soft interrupt scheduled too early");
CTR3(KTR_INTR, "sched_softintr pid %d(%s) spending=0x%x",
softithd->p_pid, softithd->p_comm, spending);
/*
* Get the sched lock and see if the thread is on whichkqs yet.
* If not, put it on there. In any case, kick everyone so that if
* the new thread is higher priority than their current thread, it
* gets run now.
*/
mtx_enter(&sched_lock, MTX_SPIN);
if (softithd->p_stat == SWAIT) { /* not on run queue */
CTR1(KTR_INTR, "sched_softintr: setrunqueue %d",
softithd->p_pid);
/* membar_lock(); */
softithd->p_stat = SRUN;
setrunqueue(softithd);
aston();
}
mtx_exit(&sched_lock, MTX_SPIN);
#if 0
aston(); /* ??? check priorities first? */
#else
need_resched();
#endif
}
SYSINIT(start_softintr, SI_SUB_SOFTINTR, SI_ORDER_FIRST, start_softintr, NULL)
/*
* Start soft interrupt thread.
*/
static void
start_softintr(dummy)
void *dummy;
{
int error;
if (softithd != NULL) { /* we already have a thread */
printf("start_softintr: already running");
return;
}
error = kthread_create(intr_soft, NULL, &softithd,
RFSTOPPED | RFHIGHPID, "softinterrupt");
if (error)
panic("start_softintr: kthread_create error %d\n", error);
softithd->p_rtprio.type = RTP_PRIO_ITHREAD;
softithd->p_rtprio.prio = PI_SOFT; /* soft interrupt */
softithd->p_stat = SWAIT; /* we're idle */
softithd->p_flag |= P_NOLOAD;
}
/*
* Software interrupt process code.
*/
static void
intr_soft(dummy)
void *dummy;
{
int i;
u_int pend;
/* Main loop */
for (;;) {
CTR3(KTR_INTR, "intr_soft pid %d(%s) spending=0x%x",
curproc->p_pid, curproc->p_comm, spending);
/*
* Service interrupts. If another interrupt arrives
* while we are running, they will set spending to
* denote that we should make another pass.
*/
pend = atomic_readandclear_int(&spending);
while ((i = ffs(pend))) {
i--;
atomic_add_long(&softintr_count[i], 1);
pend &= ~ (1 << i);
mtx_enter(&Giant, MTX_DEF);
if (shandlers[i] == swi_generic)
swi_dispatcher(i);
else
(shandlers[i])();
mtx_exit(&Giant, MTX_DEF);
}
/*
* Processed all our interrupts. Now get the sched
* lock. This may take a while and spending may get
* set again, so we have to check it again.
*/
mtx_enter(&sched_lock, MTX_SPIN);
if (spending == 0) {
CTR1(KTR_INTR, "intr_soft pid %d: done",
curproc->p_pid);
curproc->p_stat = SWAIT; /* we're idle */
mi_switch();
CTR1(KTR_INTR, "intr_soft pid %d: resumed",
curproc->p_pid);
}
mtx_exit(&sched_lock, MTX_SPIN);
}
}
/*
* Bits in the spending bitmap variable must be set atomically because
* spending may be manipulated by interrupts or other cpu's without holding
* any locks.
*
* Note: setbits uses a locked or, making simple cases MP safe.
*/
#define DO_SETBITS(name, var, bits) \
void name(void) \
{ \
atomic_set_int(var, bits); \
sched_softintr(); \
}
#define DO_SETBITS_AND_NO_MORE(name, var, bits) \
void name(void) \
{ \
atomic_set_int(var, bits); \
}
DO_SETBITS(setsoftcamnet,&spending, SWI_CAMNET_PENDING)
DO_SETBITS(setsoftcambio,&spending, SWI_CAMBIO_PENDING)
DO_SETBITS(setsoftclock, &spending, SWI_CLOCK_PENDING)
DO_SETBITS(setsoftnet, &spending, SWI_NET_PENDING)
DO_SETBITS(setsofttty, &spending, SWI_TTY_PENDING)
DO_SETBITS(setsoftvm, &spending, SWI_VM_PENDING)
DO_SETBITS(setsofttq, &spending, SWI_TQ_PENDING)
DO_SETBITS_AND_NO_MORE(schedsoftcamnet, &sdelayed, SWI_CAMNET_PENDING)
DO_SETBITS_AND_NO_MORE(schedsoftcambio, &sdelayed, SWI_CAMBIO_PENDING)
DO_SETBITS_AND_NO_MORE(schedsoftnet, &sdelayed, SWI_NET_PENDING)
DO_SETBITS_AND_NO_MORE(schedsofttty, &sdelayed, SWI_TTY_PENDING)
DO_SETBITS_AND_NO_MORE(schedsoftvm, &sdelayed, SWI_VM_PENDING)
DO_SETBITS_AND_NO_MORE(schedsofttq, &sdelayed, SWI_TQ_PENDING)
void
setdelayed(void)
{
int pend;
pend = atomic_readandclear_int(&sdelayed);
if (pend != 0) {
atomic_set_int(&spending, pend);
sched_softintr();
}
}
intrmask_t
softclockpending(void)
{
return (spending & SWI_CLOCK_PENDING);
}
/*
* Dummy spl calls. The only reason for these is to not break
* all the code which expects to call them.
*/
void spl0 (void) {}
void splx (intrmask_t x) {}
intrmask_t splq(intrmask_t mask) { return 0; }
intrmask_t splbio(void) { return 0; }
intrmask_t splcam(void) { return 0; }
intrmask_t splclock(void) { return 0; }
intrmask_t splhigh(void) { return 0; }
intrmask_t splimp(void) { return 0; }
intrmask_t splnet(void) { return 0; }
intrmask_t splsoftcam(void) { return 0; }
intrmask_t splsoftcambio(void) { return 0; }
intrmask_t splsoftcamnet(void) { return 0; }
intrmask_t splsoftclock(void) { return 0; }
intrmask_t splsofttty(void) { return 0; }
intrmask_t splsoftvm(void) { return 0; }
intrmask_t splsofttq(void) { return 0; }
intrmask_t splstatclock(void) { return 0; }
intrmask_t spltty(void) { return 0; }
intrmask_t splvm(void) { return 0; }