nmi.c revision 71236
1/*-
2 * Copyright (c) 1991 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * William Jolitz.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by the University of
19 *	California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 *	from: @(#)isa.c	7.2 (Berkeley) 5/13/91
37 * $FreeBSD: head/sys/i386/isa/nmi.c 71236 2001-01-19 09:07:16Z peter $
38 */
39
40#include "opt_auto_eoi.h"
41
42#include "isa.h"
43
44#include <sys/param.h>
45#include <sys/bus.h>
46#ifndef SMP
47#include <machine/lock.h>
48#endif
49#include <sys/proc.h>
50#include <sys/systm.h>
51#include <sys/syslog.h>
52#include <sys/ipl.h>
53#include <sys/kernel.h>
54#include <sys/kthread.h>
55#include <sys/malloc.h>
56#include <sys/module.h>
57#include <sys/mutex.h>
58#include <sys/unistd.h>
59#include <sys/errno.h>
60#include <sys/interrupt.h>
61#include <machine/md_var.h>
62#include <machine/segments.h>
63#include <sys/bus.h>
64
65#if defined(APIC_IO)
66#include <machine/smptests.h>			/** FAST_HI */
67#include <machine/smp.h>
68#include <machine/resource.h>
69#endif /* APIC_IO */
70#ifdef PC98
71#include <pc98/pc98/pc98.h>
72#include <pc98/pc98/pc98_machdep.h>
73#include <pc98/pc98/epsonio.h>
74#else
75#include <i386/isa/isa.h>
76#endif
77#include <i386/isa/icu.h>
78
79#if NISA > 0
80#include <isa/isavar.h>
81#endif
82#include <i386/isa/intr_machdep.h>
83#include <sys/interrupt.h>
84#ifdef APIC_IO
85#include <machine/clock.h>
86#endif
87
88#include "mca.h"
89#if NMCA > 0
90#include <i386/isa/mca_machdep.h>
91#endif
92
93/*
94 * Per-interrupt data.
95 */
96u_long	*intr_countp[ICU_LEN];		/* pointers to interrupt counters */
97driver_intr_t *intr_handler[ICU_LEN];	/* first level interrupt handler */
98struct ithd *ithds[ICU_LEN];		/* real interrupt handler */
99void	*intr_unit[ICU_LEN];
100
101static inthand_t *fastintr[ICU_LEN] = {
102	&IDTVEC(fastintr0), &IDTVEC(fastintr1),
103	&IDTVEC(fastintr2), &IDTVEC(fastintr3),
104	&IDTVEC(fastintr4), &IDTVEC(fastintr5),
105	&IDTVEC(fastintr6), &IDTVEC(fastintr7),
106	&IDTVEC(fastintr8), &IDTVEC(fastintr9),
107	&IDTVEC(fastintr10), &IDTVEC(fastintr11),
108	&IDTVEC(fastintr12), &IDTVEC(fastintr13),
109	&IDTVEC(fastintr14), &IDTVEC(fastintr15),
110#if defined(APIC_IO)
111	&IDTVEC(fastintr16), &IDTVEC(fastintr17),
112	&IDTVEC(fastintr18), &IDTVEC(fastintr19),
113	&IDTVEC(fastintr20), &IDTVEC(fastintr21),
114	&IDTVEC(fastintr22), &IDTVEC(fastintr23),
115#endif /* APIC_IO */
116};
117
118static inthand_t *slowintr[ICU_LEN] = {
119	&IDTVEC(intr0), &IDTVEC(intr1), &IDTVEC(intr2), &IDTVEC(intr3),
120	&IDTVEC(intr4), &IDTVEC(intr5), &IDTVEC(intr6), &IDTVEC(intr7),
121	&IDTVEC(intr8), &IDTVEC(intr9), &IDTVEC(intr10), &IDTVEC(intr11),
122	&IDTVEC(intr12), &IDTVEC(intr13), &IDTVEC(intr14), &IDTVEC(intr15),
123#if defined(APIC_IO)
124	&IDTVEC(intr16), &IDTVEC(intr17), &IDTVEC(intr18), &IDTVEC(intr19),
125	&IDTVEC(intr20), &IDTVEC(intr21), &IDTVEC(intr22), &IDTVEC(intr23),
126#endif /* APIC_IO */
127};
128
129static driver_intr_t isa_strayintr;
130
131#ifdef PC98
132#define NMI_PARITY 0x04
133#define NMI_EPARITY 0x02
134#else
135#define NMI_PARITY (1 << 7)
136#define NMI_IOCHAN (1 << 6)
137#define ENMI_WATCHDOG (1 << 7)
138#define ENMI_BUSTIMER (1 << 6)
139#define ENMI_IOSTATUS (1 << 5)
140#endif
141
142/*
143 * Bus attachment for the ISA PIC.
144 */
145static struct isa_pnp_id atpic_ids[] = {
146	{ 0x0000d041 /* PNP0000 */, "AT interrupt controller" },
147	{ 0 }
148};
149
150static int
151atpic_probe(device_t dev)
152{
153	int result;
154
155	if ((result = ISA_PNP_PROBE(device_get_parent(dev), dev, atpic_ids)) <= 0)
156		device_quiet(dev);
157	return(result);
158}
159
160/*
161 * In the APIC_IO case we might be granted IRQ 2, as this is typically
162 * consumed by chaining between the two PIC components.  If we're using
163 * the APIC, however, this may not be the case, and as such we should
164 * free the resource.  (XXX untested)
165 *
166 * The generic ISA attachment code will handle allocating any other resources
167 * that we don't explicitly claim here.
168 */
169static int
170atpic_attach(device_t dev)
171{
172#ifdef APIC_IO
173	int		rid;
174	struct resource *res;
175
176	/* try to allocate our IRQ and then free it */
177	rid = 0;
178	res = bus_alloc_resource(dev, SYS_RES_IRQ, &rid, 0, ~0, 1, 0);
179	if (res != NULL)
180		bus_release_resource(dev, SYS_RES_IRQ, rid, res);
181#endif
182	return(0);
183}
184
185static device_method_t atpic_methods[] = {
186	/* Device interface */
187	DEVMETHOD(device_probe,		atpic_probe),
188	DEVMETHOD(device_attach,	atpic_attach),
189	DEVMETHOD(device_detach,	bus_generic_detach),
190	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
191	DEVMETHOD(device_suspend,	bus_generic_suspend),
192	DEVMETHOD(device_resume,	bus_generic_resume),
193	{ 0, 0 }
194};
195
196static driver_t atpic_driver = {
197	"atpic",
198	atpic_methods,
199	1,		/* no softc */
200};
201
202static devclass_t atpic_devclass;
203
204DRIVER_MODULE(atpic, isa, atpic_driver, atpic_devclass, 0, 0);
205
206/*
207 * Handle a NMI, possibly a machine check.
208 * return true to panic system, false to ignore.
209 */
210int
211isa_nmi(cd)
212	int cd;
213{
214	int retval = 0;
215#ifdef PC98
216 	int port = inb(0x33);
217
218	log(LOG_CRIT, "NMI PC98 port = %x\n", port);
219	if (epson_machine_id == 0x20)
220		epson_outb(0xc16, epson_inb(0xc16) | 0x1);
221	if (port & NMI_PARITY) {
222		log(LOG_CRIT, "BASE RAM parity error, likely hardware failure.");
223		retval = 1;
224	} else if (port & NMI_EPARITY) {
225		log(LOG_CRIT, "EXTENDED RAM parity error, likely hardware failure.");
226		retval = 1;
227	} else {
228		log(LOG_CRIT, "\nNMI Resume ??\n");
229	}
230#else /* IBM-PC */
231	int isa_port = inb(0x61);
232	int eisa_port = inb(0x461);
233
234	log(LOG_CRIT, "NMI ISA %x, EISA %x\n", isa_port, eisa_port);
235#if NMCA > 0
236	if (MCA_system && mca_bus_nmi())
237		return(0);
238#endif
239
240	if (isa_port & NMI_PARITY) {
241		log(LOG_CRIT, "RAM parity error, likely hardware failure.");
242		retval = 1;
243	}
244
245	if (isa_port & NMI_IOCHAN) {
246		log(LOG_CRIT, "I/O channel check, likely hardware failure.");
247		retval = 1;
248	}
249
250	/*
251	 * On a real EISA machine, this will never happen.  However it can
252	 * happen on ISA machines which implement XT style floating point
253	 * error handling (very rare).  Save them from a meaningless panic.
254	 */
255	if (eisa_port == 0xff)
256		return(retval);
257
258	if (eisa_port & ENMI_WATCHDOG) {
259		log(LOG_CRIT, "EISA watchdog timer expired, likely hardware failure.");
260		retval = 1;
261	}
262
263	if (eisa_port & ENMI_BUSTIMER) {
264		log(LOG_CRIT, "EISA bus timeout, likely hardware failure.");
265		retval = 1;
266	}
267
268	if (eisa_port & ENMI_IOSTATUS) {
269		log(LOG_CRIT, "EISA I/O port status error.");
270		retval = 1;
271	}
272#endif
273	return(retval);
274}
275
276/*
277 * Create a default interrupt table to avoid problems caused by
278 * spurious interrupts during configuration of kernel, then setup
279 * interrupt control unit.
280 */
281void
282isa_defaultirq()
283{
284	int i;
285
286	/* icu vectors */
287	for (i = 0; i < ICU_LEN; i++)
288		icu_unset(i, (driver_intr_t *)NULL);
289
290	/* initialize 8259's */
291#if NMCA > 0
292	if (MCA_system)
293		outb(IO_ICU1, 0x19);		/* reset; program device, four bytes */
294	else
295#endif
296		outb(IO_ICU1, 0x11);		/* reset; program device, four bytes */
297
298	outb(IO_ICU1+ICU_IMR_OFFSET, NRSVIDT);	/* starting at this vector index */
299	outb(IO_ICU1+ICU_IMR_OFFSET, IRQ_SLAVE);		/* slave on line 7 */
300#ifdef PC98
301#ifdef AUTO_EOI_1
302	outb(IO_ICU1+ICU_IMR_OFFSET, 0x1f);		/* (master) auto EOI, 8086 mode */
303#else
304	outb(IO_ICU1+ICU_IMR_OFFSET, 0x1d);		/* (master) 8086 mode */
305#endif
306#else /* IBM-PC */
307#ifdef AUTO_EOI_1
308	outb(IO_ICU1+ICU_IMR_OFFSET, 2 | 1);		/* auto EOI, 8086 mode */
309#else
310	outb(IO_ICU1+ICU_IMR_OFFSET, 1);		/* 8086 mode */
311#endif
312#endif /* PC98 */
313	outb(IO_ICU1+ICU_IMR_OFFSET, 0xff);		/* leave interrupts masked */
314	outb(IO_ICU1, 0x0a);		/* default to IRR on read */
315#ifndef PC98
316	outb(IO_ICU1, 0xc0 | (3 - 1));	/* pri order 3-7, 0-2 (com2 first) */
317#endif /* !PC98 */
318
319#if NMCA > 0
320	if (MCA_system)
321		outb(IO_ICU2, 0x19);		/* reset; program device, four bytes */
322	else
323#endif
324		outb(IO_ICU2, 0x11);		/* reset; program device, four bytes */
325
326	outb(IO_ICU2+ICU_IMR_OFFSET, NRSVIDT+8); /* staring at this vector index */
327	outb(IO_ICU2+ICU_IMR_OFFSET, ICU_SLAVEID);         /* my slave id is 7 */
328#ifdef PC98
329	outb(IO_ICU2+ICU_IMR_OFFSET,9);              /* 8086 mode */
330#else /* IBM-PC */
331#ifdef AUTO_EOI_2
332	outb(IO_ICU2+ICU_IMR_OFFSET, 2 | 1);		/* auto EOI, 8086 mode */
333#else
334	outb(IO_ICU2+ICU_IMR_OFFSET,1);		/* 8086 mode */
335#endif
336#endif /* PC98 */
337	outb(IO_ICU2+ICU_IMR_OFFSET, 0xff);          /* leave interrupts masked */
338	outb(IO_ICU2, 0x0a);		/* default to IRR on read */
339}
340
341/*
342 * Caught a stray interrupt, notify
343 */
344static void
345isa_strayintr(vcookiep)
346	void *vcookiep;
347{
348	int intr = (void **)vcookiep - &intr_unit[0];
349
350	/*
351	 * XXX TODO print a different message for #7 if it is for a
352	 * glitch.  Glitches can be distinguished from real #7's by
353	 * testing that the in-service bit is _not_ set.  The test
354	 * must be done before sending an EOI so it can't be done if
355	 * we are using AUTO_EOI_1.
356	 */
357	if (intrcnt[1 + intr] <= 5)
358		log(LOG_ERR, "stray irq %d\n", intr);
359	if (intrcnt[1 + intr] == 5)
360		log(LOG_CRIT,
361		    "too many stray irq %d's; not logging any more\n", intr);
362}
363
364#if NISA > 0
365/*
366 * Return a bitmap of the current interrupt requests.  This is 8259-specific
367 * and is only suitable for use at probe time.
368 */
369intrmask_t
370isa_irq_pending()
371{
372	u_char irr1;
373	u_char irr2;
374
375	irr1 = inb(IO_ICU1);
376	irr2 = inb(IO_ICU2);
377	return ((irr2 << 8) | irr1);
378}
379#endif
380
381/*
382 * Update intrnames array with the specified name.  This is used by
383 * vmstat(8) and the like.
384 */
385static void
386update_intrname(int intr, char *name)
387{
388	char buf[32];
389	char *cp;
390	int name_index, off, strayintr;
391
392	/*
393	 * Initialise strings for bitbucket and stray interrupt counters.
394	 * These have statically allocated indices 0 and 1 through ICU_LEN.
395	 */
396	if (intrnames[0] == '\0') {
397		off = sprintf(intrnames, "???") + 1;
398		for (strayintr = 0; strayintr < ICU_LEN; strayintr++)
399			off += sprintf(intrnames + off, "stray irq%d",
400			    strayintr) + 1;
401	}
402
403	if (name == NULL)
404		name = "???";
405	if (snprintf(buf, sizeof(buf), "%s irq%d", name, intr) >= sizeof(buf))
406		goto use_bitbucket;
407
408	/*
409	 * Search for `buf' in `intrnames'.  In the usual case when it is
410	 * not found, append it to the end if there is enough space (the \0
411	 * terminator for the previous string, if any, becomes a separator).
412	 */
413	for (cp = intrnames, name_index = 0;
414	    cp != eintrnames && name_index < NR_INTRNAMES;
415	    cp += strlen(cp) + 1, name_index++) {
416		if (*cp == '\0') {
417			if (strlen(buf) >= eintrnames - cp)
418				break;
419			strcpy(cp, buf);
420			goto found;
421		}
422		if (strcmp(cp, buf) == 0)
423			goto found;
424	}
425
426use_bitbucket:
427	printf("update_intrname: counting %s irq%d as %s\n", name, intr,
428	    intrnames);
429	name_index = 0;
430found:
431	intr_countp[intr] = &intrcnt[name_index];
432}
433
434int
435icu_setup(int intr, driver_intr_t *handler, void *arg, int flags)
436{
437#ifdef FAST_HI
438	int		select;		/* the select register is 8 bits */
439	int		vector;
440	u_int32_t	value;		/* the window register is 32 bits */
441#endif /* FAST_HI */
442	u_long	ef;
443
444#if defined(APIC_IO)
445	if ((u_int)intr >= ICU_LEN)	/* no 8259 SLAVE to ignore */
446#else
447	if ((u_int)intr >= ICU_LEN || intr == ICU_SLAVEID)
448#endif /* APIC_IO */
449	if (intr_handler[intr] != isa_strayintr)
450		return (EBUSY);
451
452	ef = read_eflags();
453	disable_intr();
454	intr_handler[intr] = handler;
455	intr_unit[intr] = arg;
456#ifdef FAST_HI
457	if (flags & INTR_FAST) {
458		vector = TPR_FAST_INTS + intr;
459		setidt(vector, fastintr[intr],
460		       SDT_SYS386IGT, SEL_KPL, GSEL(GCODE_SEL, SEL_KPL));
461	}
462	else {
463		vector = TPR_SLOW_INTS + intr;
464#ifdef APIC_INTR_REORDER
465#ifdef APIC_INTR_HIGHPRI_CLOCK
466		/* XXX: Hack (kludge?) for more accurate clock. */
467		if (intr == apic_8254_intr || intr == 8) {
468			vector = TPR_FAST_INTS + intr;
469		}
470#endif
471#endif
472		setidt(vector, slowintr[intr],
473		       SDT_SYS386IGT, SEL_KPL, GSEL(GCODE_SEL, SEL_KPL));
474	}
475#ifdef APIC_INTR_REORDER
476	set_lapic_isrloc(intr, vector);
477#endif
478	/*
479	 * Reprogram the vector in the IO APIC.
480	 */
481	if (int_to_apicintpin[intr].ioapic >= 0) {
482		select = int_to_apicintpin[intr].redirindex;
483		value = io_apic_read(int_to_apicintpin[intr].ioapic,
484				     select) & ~IOART_INTVEC;
485		io_apic_write(int_to_apicintpin[intr].ioapic,
486			      select, value | vector);
487	}
488#else
489	setidt(ICU_OFFSET + intr,
490	       flags & INTR_FAST ? fastintr[intr] : slowintr[intr],
491	       SDT_SYS386IGT, SEL_KPL, GSEL(GCODE_SEL, SEL_KPL));
492#endif /* FAST_HI */
493	INTREN(1 << intr);
494	write_eflags(ef);
495	return (0);
496}
497
498/*
499 * Dissociate an interrupt handler from an IRQ and set the handler to
500 * the stray interrupt handler.  The 'handler' parameter is used only
501 * for consistency checking.
502 */
503int
504icu_unset(intr, handler)
505	int	intr;
506	driver_intr_t *handler;
507{
508	u_long	ef;
509
510	if ((u_int)intr >= ICU_LEN || handler != intr_handler[intr])
511		return (EINVAL);
512
513	INTRDIS(1 << intr);
514	ef = read_eflags();
515	disable_intr();
516	intr_countp[intr] = &intrcnt[1 + intr];
517	intr_handler[intr] = isa_strayintr;
518	intr_unit[intr] = &intr_unit[intr];
519#ifdef FAST_HI_XXX
520	/* XXX how do I re-create dvp here? */
521	setidt(flags & INTR_FAST ? TPR_FAST_INTS + intr : TPR_SLOW_INTS + intr,
522	    slowintr[intr], SDT_SYS386IGT, SEL_KPL, GSEL(GCODE_SEL, SEL_KPL));
523#else /* FAST_HI */
524#ifdef APIC_INTR_REORDER
525	set_lapic_isrloc(intr, ICU_OFFSET + intr);
526#endif
527	setidt(ICU_OFFSET + intr, slowintr[intr], SDT_SYS386IGT, SEL_KPL,
528	    GSEL(GCODE_SEL, SEL_KPL));
529#endif /* FAST_HI */
530	write_eflags(ef);
531	return (0);
532}
533
534struct intrhand *
535inthand_add(const char *name, int irq, driver_intr_t handler, void *arg,
536	     int pri, int flags)
537{
538	struct ithd *ithd = ithds[irq];	/* descriptor for the IRQ */
539	struct intrhand *head;		/* chain of handlers for IRQ */
540	struct intrhand *idesc;		/* descriptor for this handler */
541	struct proc *p;			/* interrupt thread */
542	int errcode = 0;
543
544	if (name == NULL)		/* no name? */
545		panic ("anonymous interrupt");
546	if (ithd == NULL || ithd->it_ih == NULL) {
547		/* first handler for this irq. */
548		if (ithd == NULL) {
549			ithd = malloc(sizeof (struct ithd), M_DEVBUF,
550			    M_WAITOK | M_ZERO);
551			if (ithd == NULL)
552				return (NULL);
553			ithd->irq = irq;
554			ithds[irq] = ithd;
555		}
556		/*
557		 * If we have a fast interrupt, we need to set the
558		 * handler address directly.  Do that below.  For a
559		 * slow interrupt, we don't need to know more details,
560		 * so do it here because it's tidier.
561		 */
562		if ((flags & INTR_FAST)	== 0) {
563			/*
564			 * Only create a kernel thread if we don't already
565			 * have one.
566			 */
567			if (ithd->it_proc == NULL) {
568				errcode = kthread_create(ithd_loop, NULL, &p,
569				    RFSTOPPED | RFHIGHPID, "irq%d: %s", irq,
570				    name);
571				if (errcode)
572					panic("inthand_add: Can't create "
573					      "interrupt thread");
574				p->p_rtprio.type = RTP_PRIO_ITHREAD;
575				p->p_stat = SWAIT; /* we're idle */
576
577				/* Put in linkages. */
578				ithd->it_proc = p;
579				p->p_ithd = ithd;
580			} else
581				snprintf(ithd->it_proc->p_comm, MAXCOMLEN,
582				    "irq%d: %s", irq, name);
583			p->p_rtprio.prio = pri;
584
585			/*
586			 * The interrupt process must be in place, but
587			 * not necessarily schedulable, before we
588			 * initialize the ICU, since it may cause an
589			 * immediate interrupt.
590			 */
591			if (icu_setup(irq, &sched_ithd, arg, flags) != 0)
592				panic("inthand_add: Can't initialize ICU");
593		}
594	} else if ((flags & INTR_EXCL) != 0
595		   || (ithd->it_ih->ih_flags & INTR_EXCL) != 0) {
596		/*
597		 * We can't append the new handler if either
598		 * list ithd or new handler do not allow
599		 * interrupts to be shared.
600		 */
601		if (bootverbose)
602			printf("\tdevice combination %s and %s "
603			       "doesn't support shared irq%d\n",
604			       ithd->it_ih->ih_name, name, irq);
605		return(NULL);
606	} else if (flags & INTR_FAST) {
607		 /* We can only have one fast interrupt by itself. */
608		if (bootverbose)
609			printf("\tCan't add fast interrupt %s"
610 			       " to normal interrupt %s on irq%d",
611			       name, ithd->it_ih->ih_name, irq);
612		return (NULL);
613	} else {			/* update p_comm */
614		p = ithd->it_proc;
615		if (strlen(p->p_comm) + strlen(name) < MAXCOMLEN) {
616			strcat(p->p_comm, " ");
617			strcat(p->p_comm, name);
618		} else if (strlen(p->p_comm) == MAXCOMLEN)
619			p->p_comm[MAXCOMLEN - 1] = '+';
620		else
621			strcat(p->p_comm, "+");
622	}
623	idesc = malloc(sizeof (struct intrhand), M_DEVBUF, M_WAITOK | M_ZERO);
624	if (idesc == NULL)
625		return (NULL);
626
627	idesc->ih_handler = handler;
628	idesc->ih_argument = arg;
629	idesc->ih_flags = flags;
630	idesc->ih_ithd = ithd;
631
632	idesc->ih_name = malloc(strlen(name) + 1, M_DEVBUF, M_WAITOK);
633	if (idesc->ih_name == NULL) {
634		free(idesc, M_DEVBUF);
635		return (NULL);
636	}
637	strcpy(idesc->ih_name, name);
638
639	/* Slow interrupts got set up above. */
640	if ((flags & INTR_FAST)
641		&& (icu_setup(irq, idesc->ih_handler, idesc->ih_argument,
642			      idesc->ih_flags) != 0) ) {
643		if (bootverbose)
644			printf("\tinthand_add(irq%d) failed, result=%d\n",
645			       irq, errcode);
646		free(idesc->ih_name, M_DEVBUF);
647		free(idesc, M_DEVBUF);
648		return NULL;
649	}
650	head = ithd->it_ih;		/* look at chain of handlers */
651	if (head) {
652		while (head->ih_next != NULL)
653			head = head->ih_next; /* find the end */
654		head->ih_next = idesc;	/* hook it in there */
655	} else
656		ithd->it_ih = idesc;	/* put it up front */
657	update_intrname(irq, idesc->ih_name);
658	return (idesc);
659}
660
661/*
662 * Deactivate and remove linked list the interrupt handler descriptor
663 * data connected created by an earlier call of inthand_add(), then
664 * adjust the interrupt masks if necessary.
665 *
666 * Return the memory held by the interrupt handler descriptor data
667 * structure to the system.  First ensure the handler is not actively
668 * in use.
669 */
670
671int
672inthand_remove(struct intrhand *idesc)
673{
674	struct ithd *ithd;		/* descriptor for the IRQ */
675	struct intrhand *ih;		/* chain of handlers */
676
677	if (idesc == NULL)
678		return (-1);
679	ithd = idesc->ih_ithd;
680	ih = ithd->it_ih;
681
682	if (ih == idesc)		/* first in the chain */
683		ithd->it_ih = idesc->ih_next; /* unhook it */
684	else {
685		while ((ih != NULL)
686			&& (ih->ih_next != idesc) )
687			ih = ih->ih_next;
688		if (ih->ih_next != idesc)
689			return (-1);
690		ih->ih_next = ih->ih_next->ih_next;
691	}
692
693	if (ithd->it_ih == NULL) {	/* no handlers left, */
694		icu_unset(ithd->irq, idesc->ih_handler);
695		ithds[ithd->irq] = NULL;
696
697		if ((idesc->ih_flags & INTR_FAST) == 0) {
698			mtx_enter(&sched_lock, MTX_SPIN);
699			if (ithd->it_proc->p_stat == SWAIT) {
700				ithd->it_proc->p_stat = SRUN;
701				setrunqueue(ithd->it_proc);
702				/*
703				 * We don't do an ast here because we really
704				 * don't care when it runs next.
705				 *
706				 * XXX: should we lower the threads priority?
707				 */
708			}
709			mtx_exit(&sched_lock, MTX_SPIN);
710		}
711	}
712	free(idesc->ih_name, M_DEVBUF);
713	free(idesc, M_DEVBUF);
714	return (0);
715}
716