xref: /netbsd-src/sys/arch/arm/pic/pic.c (revision 413d532bcc3f62d122e56d92e13ac64825a40baf)
1 /*	$NetBSD: pic.c,v 1.21 2014/03/13 23:47:53 matt Exp $	*/
2 /*-
3  * Copyright (c) 2008 The NetBSD Foundation, Inc.
4  * All rights reserved.
5  *
6  * This code is derived from software contributed to The NetBSD Foundation
7  * by Matt Thomas.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
19  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
20  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
22  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28  * POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #define _INTR_PRIVATE
32 #include "opt_ddb.h"
33 
34 #include <sys/cdefs.h>
35 __KERNEL_RCSID(0, "$NetBSD: pic.c,v 1.21 2014/03/13 23:47:53 matt Exp $");
36 
37 #include <sys/param.h>
38 #include <sys/atomic.h>
39 #include <sys/cpu.h>
40 #include <sys/evcnt.h>
41 #include <sys/intr.h>
42 #include <sys/kernel.h>
43 #include <sys/kmem.h>
44 #include <sys/xcall.h>
45 
46 #include <arm/armreg.h>
47 #include <arm/cpufunc.h>
48 
49 #ifdef DDB
50 #include <arm/db_machdep.h>
51 #endif
52 
53 #include <arm/pic/picvar.h>
54 
55 static uint32_t
56 	pic_find_pending_irqs_by_ipl(struct pic_softc *, size_t, uint32_t, int);
57 static struct pic_softc *
58 	pic_list_find_pic_by_pending_ipl(uint32_t);
59 static void
60 	pic_deliver_irqs(struct pic_softc *, int, void *);
61 static void
62 	pic_list_deliver_irqs(register_t, int, void *);
63 
64 struct pic_softc *pic_list[PIC_MAXPICS];
65 #if PIC_MAXPICS > 32
66 #error PIC_MAXPICS > 32 not supported
67 #endif
68 volatile uint32_t pic_blocked_pics;
69 volatile uint32_t pic_pending_pics;
70 volatile uint32_t pic_pending_ipls;
71 struct intrsource *pic_sources[PIC_MAXMAXSOURCES];
72 struct intrsource *pic__iplsources[PIC_MAXMAXSOURCES];
73 struct intrsource **pic_iplsource[NIPL] = {
74 	[0 ... NIPL-1] = pic__iplsources,
75 };
76 size_t pic_ipl_offset[NIPL+1];
77 size_t pic_sourcebase;
78 static struct evcnt pic_deferral_ev =
79     EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, "deferred", "intr");
80 EVCNT_ATTACH_STATIC(pic_deferral_ev);
81 
82 #ifdef __HAVE_PIC_SET_PRIORITY
83 void
84 pic_set_priority(struct cpu_info *ci, int newipl)
85 {
86 	register_t psw = cpsid(I32_bit);
87 	if (pic_list[0] != NULL)
88 		(pic_list[0]->pic_ops->pic_set_priority)(pic_list[0], newipl);
89 	ci->ci_cpl = newipl;
90 	if ((psw & I32_bit) == 0)
91 		cpsie(I32_bit);
92 }
93 #endif
94 
95 #ifdef MULTIPROCESSOR
96 int
97 pic_ipi_nop(void *arg)
98 {
99 	/* do nothing */
100 	return 1;
101 }
102 
103 int
104 pic_ipi_xcall(void *arg)
105 {
106 	xc_ipi_handler();
107 	return 1;
108 }
109 
110 #ifdef DDB
111 int
112 pic_ipi_ddb(void *arg)
113 {
114 	printf("%s: %s: tf=%p\n", __func__, curcpu()->ci_cpuname, arg);
115 	kdb_trap(-1, arg);
116 	return 1;
117 }
118 #endif
119 
120 void
121 intr_cpu_init(struct cpu_info *ci)
122 {
123 	for (size_t slot = 0; slot < PIC_MAXPICS; slot++) {
124 		struct pic_softc * const pic = pic_list[slot];
125 		if (pic != NULL && pic->pic_ops->pic_cpu_init != NULL) {
126 			(*pic->pic_ops->pic_cpu_init)(pic, ci);
127 		}
128 	}
129 }
130 
131 typedef void (*pic_ipi_send_func_t)(struct pic_softc *, u_long);
132 
133 static struct pic_softc *
134 pic_ipi_sender(void)
135 {
136 	for (size_t slot = 0; slot < PIC_MAXPICS; slot++) {
137 		struct pic_softc * const pic = pic_list[slot];
138 		if (pic != NULL && pic->pic_ops->pic_ipi_send != NULL) {
139 			return pic;
140 		}
141 	}
142 	return NULL;
143 }
144 
145 void
146 intr_ipi_send(const kcpuset_t *kcp, u_long ipi)
147 {
148 	struct pic_softc * const pic = pic_ipi_sender();
149 	KASSERT(ipi < NIPI);
150 	if (cold && pic == NULL)
151 		return;
152 	KASSERT(pic != NULL);
153 	(*pic->pic_ops->pic_ipi_send)(pic, kcp, ipi);
154 }
155 #endif /* MULTIPROCESSOR */
156 
157 #ifdef __HAVE_PIC_FAST_SOFTINTS
158 int
159 pic_handle_softint(void *arg)
160 {
161 	void softint_switch(lwp_t *, int);
162 	struct cpu_info * const ci = curcpu();
163 	const size_t softint = (size_t) arg;
164 	int s = splhigh();
165 	ci->ci_intr_depth--;	// don't count these as interrupts
166 	softint_switch(ci->ci_softlwps[softint], s);
167 	ci->ci_intr_depth++;
168 	splx(s);
169 	return 1;
170 }
171 #endif
172 
173 int
174 pic_handle_intr(void *arg)
175 {
176 	struct pic_softc * const pic = arg;
177 	int rv;
178 
179 	rv = (*pic->pic_ops->pic_find_pending_irqs)(pic);
180 
181 	return rv > 0;
182 }
183 
184 void
185 pic_mark_pending_source(struct pic_softc *pic, struct intrsource *is)
186 {
187 	const uint32_t ipl_mask = __BIT(is->is_ipl);
188 
189 	atomic_or_32(&pic->pic_pending_irqs[is->is_irq >> 5],
190 	    __BIT(is->is_irq & 0x1f));
191 
192 	atomic_or_32(&pic->pic_pending_ipls, ipl_mask);
193 	atomic_or_32(&pic_pending_ipls, ipl_mask);
194 	atomic_or_32(&pic_pending_pics, __BIT(pic->pic_id));
195 }
196 
197 void
198 pic_mark_pending(struct pic_softc *pic, int irq)
199 {
200 	struct intrsource * const is = pic->pic_sources[irq];
201 
202 	KASSERT(irq < pic->pic_maxsources);
203 	KASSERT(is != NULL);
204 
205 	pic_mark_pending_source(pic, is);
206 }
207 
208 uint32_t
209 pic_mark_pending_sources(struct pic_softc *pic, size_t irq_base,
210 	uint32_t pending)
211 {
212 	struct intrsource ** const isbase = &pic->pic_sources[irq_base];
213 	struct intrsource *is;
214 	volatile uint32_t *ipending = &pic->pic_pending_irqs[irq_base >> 5];
215 	uint32_t ipl_mask = 0;
216 
217 	if (pending == 0)
218 		return ipl_mask;
219 
220 	KASSERT((irq_base & 31) == 0);
221 
222 	(*pic->pic_ops->pic_block_irqs)(pic, irq_base, pending);
223 
224 	atomic_or_32(ipending, pending);
225         while (pending != 0) {
226 		int n = ffs(pending);
227 		if (n-- == 0)
228 			break;
229 		is = isbase[n];
230 		KASSERT(is != NULL);
231 		KASSERT(irq_base <= is->is_irq && is->is_irq < irq_base + 32);
232 		pending &= ~__BIT(n);
233 		ipl_mask |= __BIT(is->is_ipl);
234 	}
235 
236 	atomic_or_32(&pic->pic_pending_ipls, ipl_mask);
237 	atomic_or_32(&pic_pending_ipls, ipl_mask);
238 	atomic_or_32(&pic_pending_pics, __BIT(pic->pic_id));
239 
240 	return ipl_mask;
241 }
242 
243 uint32_t
244 pic_find_pending_irqs_by_ipl(struct pic_softc *pic, size_t irq_base,
245 	uint32_t pending, int ipl)
246 {
247 	uint32_t ipl_irq_mask = 0;
248 	uint32_t irq_mask;
249 
250 	for (;;) {
251 		int irq = ffs(pending);
252 		if (irq-- == 0)
253 			return ipl_irq_mask;
254 
255 		irq_mask = __BIT(irq);
256 #if 1
257     		KASSERTMSG(pic->pic_sources[irq_base + irq] != NULL,
258 		   "%s: irq_base %zu irq %d\n", __func__, irq_base, irq);
259 #else
260 		if (pic->pic_sources[irq_base + irq] == NULL) {
261 			aprint_error("stray interrupt? irq_base=%zu irq=%d\n",
262 			    irq_base, irq);
263 		} else
264 #endif
265 		if (pic->pic_sources[irq_base + irq]->is_ipl == ipl)
266 			ipl_irq_mask |= irq_mask;
267 
268 		pending &= ~irq_mask;
269 	}
270 }
271 
272 void
273 pic_dispatch(struct intrsource *is, void *frame)
274 {
275 	int (*func)(void *) = is->is_func;
276 	void *arg = is->is_arg;
277 
278 	if (__predict_false(arg == NULL)) {
279 		if (__predict_false(frame == NULL)) {
280 			pic_deferral_ev.ev_count++;
281 			return;
282 		}
283 		arg = frame;
284 	}
285 
286 #ifdef MULTIPROCESSOR
287 	if (!is->is_mpsafe) {
288 		KERNEL_LOCK(1, NULL);
289 		const u_int ci_blcnt __diagused = curcpu()->ci_biglock_count;
290 		const u_int l_blcnt __diagused = curlwp->l_blcnt;
291 		(void)(*func)(arg);
292 		KASSERT(ci_blcnt == curcpu()->ci_biglock_count);
293 		KASSERT(l_blcnt == curlwp->l_blcnt);
294 		KERNEL_UNLOCK_ONE(NULL);
295 	} else
296 #endif
297 		(void)(*func)(arg);
298 
299 
300 	struct pic_percpu * const pcpu = percpu_getref(is->is_pic->pic_percpu);
301 	KASSERT(pcpu->pcpu_magic == PICPERCPU_MAGIC);
302 	pcpu->pcpu_evs[is->is_irq].ev_count++;
303 	percpu_putref(is->is_pic->pic_percpu);
304 }
305 
306 void
307 pic_deliver_irqs(struct pic_softc *pic, int ipl, void *frame)
308 {
309 	const uint32_t ipl_mask = __BIT(ipl);
310 	struct intrsource *is;
311 	volatile uint32_t *ipending = pic->pic_pending_irqs;
312 	volatile uint32_t *iblocked = pic->pic_blocked_irqs;
313 	size_t irq_base;
314 #if PIC_MAXSOURCES > 32
315 	size_t irq_count;
316 	int poi = 0;		/* Possibility of interrupting */
317 #endif
318 	uint32_t pending_irqs;
319 	uint32_t blocked_irqs;
320 	int irq;
321 	bool progress __diagused = false;
322 
323 	KASSERT(pic->pic_pending_ipls & ipl_mask);
324 
325 	irq_base = 0;
326 #if PIC_MAXSOURCES > 32
327 	irq_count = 0;
328 #endif
329 
330 	for (;;) {
331 		pending_irqs = pic_find_pending_irqs_by_ipl(pic, irq_base,
332 		    *ipending, ipl);
333 		KASSERT((pending_irqs & *ipending) == pending_irqs);
334 		KASSERT((pending_irqs & ~(*ipending)) == 0);
335 		if (pending_irqs == 0) {
336 #if PIC_MAXSOURCES > 32
337 			irq_count += 32;
338 			if (__predict_true(irq_count >= pic->pic_maxsources)) {
339 				if (!poi)
340 					/*Interrupt at this level was handled.*/
341 					break;
342 				irq_base = 0;
343 				irq_count = 0;
344 				poi = 0;
345 				ipending = pic->pic_pending_irqs;
346 				iblocked = pic->pic_blocked_irqs;
347 			} else {
348 				irq_base += 32;
349 				ipending++;
350 				iblocked++;
351 				KASSERT(irq_base <= pic->pic_maxsources);
352 			}
353 			continue;
354 #else
355 			break;
356 #endif
357 		}
358 		progress = true;
359 		blocked_irqs = 0;
360 		do {
361 			irq = ffs(pending_irqs) - 1;
362 			KASSERT(irq >= 0);
363 
364 			atomic_and_32(ipending, ~__BIT(irq));
365 			is = pic->pic_sources[irq_base + irq];
366 			if (is != NULL) {
367 				cpsie(I32_bit);
368 				pic_dispatch(is, frame);
369 				cpsid(I32_bit);
370 #if PIC_MAXSOURCES > 32
371 				/*
372 				 * There is a possibility of interrupting
373 				 * from cpsie() to cpsid().
374 				 */
375 				poi = 1;
376 #endif
377 				blocked_irqs |= __BIT(irq);
378 			} else {
379 				KASSERT(0);
380 			}
381 			pending_irqs = pic_find_pending_irqs_by_ipl(pic,
382 			    irq_base, *ipending, ipl);
383 		} while (pending_irqs);
384 		if (blocked_irqs) {
385 			atomic_or_32(iblocked, blocked_irqs);
386 			atomic_or_32(&pic_blocked_pics, __BIT(pic->pic_id));
387 		}
388 	}
389 
390 	KASSERT(progress);
391 	/*
392 	 * Since interrupts are disabled, we don't have to be too careful
393 	 * about these.
394 	 */
395 	if (atomic_and_32_nv(&pic->pic_pending_ipls, ~ipl_mask) == 0)
396 		atomic_and_32(&pic_pending_pics, ~__BIT(pic->pic_id));
397 }
398 
399 static void
400 pic_list_unblock_irqs(void)
401 {
402 	uint32_t blocked_pics = pic_blocked_pics;
403 
404 	pic_blocked_pics = 0;
405 	for (;;) {
406 		struct pic_softc *pic;
407 #if PIC_MAXSOURCES > 32
408 		volatile uint32_t *iblocked;
409 		uint32_t blocked;
410 		size_t irq_base;
411 #endif
412 
413 		int pic_id = ffs(blocked_pics);
414 		if (pic_id-- == 0)
415 			return;
416 
417 		pic = pic_list[pic_id];
418 		KASSERT(pic != NULL);
419 #if PIC_MAXSOURCES > 32
420 		for (irq_base = 0, iblocked = pic->pic_blocked_irqs;
421 		     irq_base < pic->pic_maxsources;
422 		     irq_base += 32, iblocked++) {
423 			if ((blocked = *iblocked) != 0) {
424 				(*pic->pic_ops->pic_unblock_irqs)(pic,
425 				    irq_base, blocked);
426 				atomic_and_32(iblocked, ~blocked);
427 			}
428 		}
429 #else
430 		KASSERT(pic->pic_blocked_irqs[0] != 0);
431 		(*pic->pic_ops->pic_unblock_irqs)(pic,
432 		    0, pic->pic_blocked_irqs[0]);
433 		pic->pic_blocked_irqs[0] = 0;
434 #endif
435 		blocked_pics &= ~__BIT(pic_id);
436 	}
437 }
438 
439 
440 struct pic_softc *
441 pic_list_find_pic_by_pending_ipl(uint32_t ipl_mask)
442 {
443 	uint32_t pending_pics = pic_pending_pics;
444 	struct pic_softc *pic;
445 
446 	for (;;) {
447 		int pic_id = ffs(pending_pics);
448 		if (pic_id-- == 0)
449 			return NULL;
450 
451 		pic = pic_list[pic_id];
452 		KASSERT(pic != NULL);
453 		if (pic->pic_pending_ipls & ipl_mask)
454 			return pic;
455 		pending_pics &= ~__BIT(pic_id);
456 	}
457 }
458 
459 void
460 pic_list_deliver_irqs(register_t psw, int ipl, void *frame)
461 {
462 	const uint32_t ipl_mask = __BIT(ipl);
463 	struct pic_softc *pic;
464 
465 	while ((pic = pic_list_find_pic_by_pending_ipl(ipl_mask)) != NULL) {
466 		pic_deliver_irqs(pic, ipl, frame);
467 		KASSERT((pic->pic_pending_ipls & ipl_mask) == 0);
468 	}
469 	atomic_and_32(&pic_pending_ipls, ~ipl_mask);
470 }
471 
472 void
473 pic_do_pending_ints(register_t psw, int newipl, void *frame)
474 {
475 	struct cpu_info * const ci = curcpu();
476 	if (__predict_false(newipl == IPL_HIGH)) {
477 		KASSERTMSG(ci->ci_cpl == IPL_HIGH, "cpl %d", ci->ci_cpl);
478 		return;
479 	}
480 	while ((pic_pending_ipls & ~__BIT(newipl)) > __BIT(newipl)) {
481 		KASSERT(pic_pending_ipls < __BIT(NIPL));
482 		for (;;) {
483 			int ipl = 31 - __builtin_clz(pic_pending_ipls);
484 			KASSERT(ipl < NIPL);
485 			if (ipl <= newipl)
486 				break;
487 
488 			pic_set_priority(ci, ipl);
489 			pic_list_deliver_irqs(psw, ipl, frame);
490 			pic_list_unblock_irqs();
491 		}
492 	}
493 	if (ci->ci_cpl != newipl)
494 		pic_set_priority(ci, newipl);
495 }
496 
497 static void
498 pic_percpu_allocate(void *v0, void *v1, struct cpu_info *ci)
499 {
500 	struct pic_percpu * const pcpu = v0;
501 	struct pic_softc * const pic = v1;
502 
503 	pcpu->pcpu_evs = kmem_zalloc(pic->pic_maxsources * sizeof(pcpu->pcpu_evs[0]),
504 	    KM_SLEEP);
505 	KASSERT(pcpu->pcpu_evs != NULL);
506 
507 #define	PCPU_NAMELEN	32
508 #ifdef DIAGNOSTIC
509 	const size_t namelen = strlen(pic->pic_name) + 4 + strlen(ci->ci_data.cpu_name);
510 #endif
511 
512 	KASSERT(namelen < PCPU_NAMELEN);
513 	pcpu->pcpu_name = kmem_alloc(PCPU_NAMELEN, KM_SLEEP);
514 #ifdef MULTIPROCESSOR
515 	snprintf(pcpu->pcpu_name, PCPU_NAMELEN,
516 	    "%s (%s)", pic->pic_name, ci->ci_data.cpu_name);
517 #else
518 	strlcpy(pcpu->pcpu_name, pic->pic_name, PCPU_NAMELEN);
519 #endif
520 	pcpu->pcpu_magic = PICPERCPU_MAGIC;
521 #if 0
522 	printf("%s: %s %s: <%s>\n",
523 	    __func__, ci->ci_data.cpu_name, pic->pic_name,
524 	    pcpu->pcpu_name);
525 #endif
526 }
527 
528 void
529 pic_add(struct pic_softc *pic, int irqbase)
530 {
531 	int slot, maybe_slot = -1;
532 
533 	KASSERT(strlen(pic->pic_name) > 0);
534 
535 	for (slot = 0; slot < PIC_MAXPICS; slot++) {
536 		struct pic_softc * const xpic = pic_list[slot];
537 		if (xpic == NULL) {
538 			if (maybe_slot < 0)
539 				maybe_slot = slot;
540 			if (irqbase < 0)
541 				break;
542 			continue;
543 		}
544 		if (irqbase < 0 || xpic->pic_irqbase < 0)
545 			continue;
546 		if (irqbase >= xpic->pic_irqbase + xpic->pic_maxsources)
547 			continue;
548 		if (irqbase + pic->pic_maxsources <= xpic->pic_irqbase)
549 			continue;
550 		panic("pic_add: pic %s (%zu sources @ irq %u) conflicts"
551 		    " with pic %s (%zu sources @ irq %u)",
552 		    pic->pic_name, pic->pic_maxsources, irqbase,
553 		    xpic->pic_name, xpic->pic_maxsources, xpic->pic_irqbase);
554 	}
555 	slot = maybe_slot;
556 #if 0
557 	printf("%s: pic_sourcebase=%zu pic_maxsources=%zu\n",
558 	    pic->pic_name, pic_sourcebase, pic->pic_maxsources);
559 #endif
560 	KASSERTMSG(pic->pic_maxsources <= PIC_MAXSOURCES, "%zu",
561 	    pic->pic_maxsources);
562 	KASSERT(pic_sourcebase + pic->pic_maxsources <= PIC_MAXMAXSOURCES);
563 
564 	/*
565 	 * Allocate a pointer to each cpu's evcnts and then, for each cpu,
566 	 * allocate its evcnts and then attach an evcnt for each pin.
567 	 * We can't allocate the evcnt structures directly since
568 	 * percpu will move the contents of percpu memory around and
569 	 * corrupt the pointers in the evcnts themselves.  Remember, any
570 	 * problem can be solved with sufficient indirection.
571 	 */
572 	pic->pic_percpu = percpu_alloc(sizeof(struct pic_percpu));
573 	KASSERT(pic->pic_percpu != NULL);
574 
575 	/*
576 	 * Now allocate the per-cpu evcnts.
577 	 */
578 	percpu_foreach(pic->pic_percpu, pic_percpu_allocate, pic);
579 
580 	pic->pic_sources = &pic_sources[pic_sourcebase];
581 	pic->pic_irqbase = irqbase;
582 	pic_sourcebase += pic->pic_maxsources;
583 	pic->pic_id = slot;
584 #ifdef __HAVE_PIC_SET_PRIORITY
585 	KASSERT((slot == 0) == (pic->pic_ops->pic_set_priority != NULL));
586 #endif
587 #ifdef MULTIPROCESSOR
588 	KASSERT((slot == 0) == (pic->pic_ops->pic_ipi_send != NULL));
589 #endif
590 	pic_list[slot] = pic;
591 }
592 
593 int
594 pic_alloc_irq(struct pic_softc *pic)
595 {
596 	int irq;
597 
598 	for (irq = 0; irq < pic->pic_maxsources; irq++) {
599 		if (pic->pic_sources[irq] == NULL)
600 			return irq;
601 	}
602 
603 	return -1;
604 }
605 
606 static void
607 pic_percpu_evcnt_attach(void *v0, void *v1, struct cpu_info *ci)
608 {
609 	struct pic_percpu * const pcpu = v0;
610 	struct intrsource * const is = v1;
611 
612 	KASSERT(pcpu->pcpu_magic == PICPERCPU_MAGIC);
613 	evcnt_attach_dynamic(&pcpu->pcpu_evs[is->is_irq], EVCNT_TYPE_INTR, NULL,
614 	    pcpu->pcpu_name, is->is_source);
615 }
616 
617 void *
618 pic_establish_intr(struct pic_softc *pic, int irq, int ipl, int type,
619 	int (*func)(void *), void *arg)
620 {
621 	struct intrsource *is;
622 	int off, nipl;
623 
624 	if (pic->pic_sources[irq]) {
625 		printf("pic_establish_intr: pic %s irq %d already present\n",
626 		    pic->pic_name, irq);
627 		return NULL;
628 	}
629 
630 	is = kmem_zalloc(sizeof(*is), KM_SLEEP);
631 	if (is == NULL)
632 		return NULL;
633 
634 	is->is_pic = pic;
635 	is->is_irq = irq;
636 	is->is_ipl = ipl;
637 	is->is_type = type & 0xff;
638 	is->is_func = func;
639 	is->is_arg = arg;
640 #ifdef MULTIPROCESSOR
641 	is->is_mpsafe = (type & IST_MPSAFE);
642 #endif
643 
644 	if (pic->pic_ops->pic_source_name)
645 		(*pic->pic_ops->pic_source_name)(pic, irq, is->is_source,
646 		    sizeof(is->is_source));
647 	else
648 		snprintf(is->is_source, sizeof(is->is_source), "irq %d", irq);
649 
650 	/*
651 	 * Now attach the per-cpu evcnts.
652 	 */
653 	percpu_foreach(pic->pic_percpu, pic_percpu_evcnt_attach, is);
654 
655 	pic->pic_sources[irq] = is;
656 
657 	/*
658 	 * First try to use an existing slot which is empty.
659 	 */
660 	for (off = pic_ipl_offset[ipl]; off < pic_ipl_offset[ipl+1]; off++) {
661 		if (pic__iplsources[off] == NULL) {
662 			is->is_iplidx = off - pic_ipl_offset[ipl];
663 			pic__iplsources[off] = is;
664 			return is;
665 		}
666 	}
667 
668 	/*
669 	 * Move up all the sources by one.
670  	 */
671 	if (ipl < NIPL) {
672 		off = pic_ipl_offset[ipl+1];
673 		memmove(&pic__iplsources[off+1], &pic__iplsources[off],
674 		    sizeof(pic__iplsources[0]) * (pic_ipl_offset[NIPL] - off));
675 	}
676 
677 	/*
678 	 * Advance the offset of all IPLs higher than this.  Include an
679 	 * extra one as well.  Thus the number of sources per ipl is
680 	 * pic_ipl_offset[ipl+1] - pic_ipl_offset[ipl].
681 	 */
682 	for (nipl = ipl + 1; nipl <= NIPL; nipl++)
683 		pic_ipl_offset[nipl]++;
684 
685 	/*
686 	 * Insert into the previously made position at the end of this IPL's
687 	 * sources.
688 	 */
689 	off = pic_ipl_offset[ipl + 1] - 1;
690 	is->is_iplidx = off - pic_ipl_offset[ipl];
691 	pic__iplsources[off] = is;
692 
693 	(*pic->pic_ops->pic_establish_irq)(pic, is);
694 
695 	(*pic->pic_ops->pic_unblock_irqs)(pic, is->is_irq & ~0x1f,
696 	    __BIT(is->is_irq & 0x1f));
697 
698 	/* We're done. */
699 	return is;
700 }
701 
702 static void
703 pic_percpu_evcnt_deattach(void *v0, void *v1, struct cpu_info *ci)
704 {
705 	struct pic_percpu * const pcpu = v0;
706 	struct intrsource * const is = v1;
707 
708 	KASSERT(pcpu->pcpu_magic == PICPERCPU_MAGIC);
709 	evcnt_detach(&pcpu->pcpu_evs[is->is_irq]);
710 }
711 
712 void
713 pic_disestablish_source(struct intrsource *is)
714 {
715 	struct pic_softc * const pic = is->is_pic;
716 	const int irq = is->is_irq;
717 
718 	KASSERT(is == pic->pic_sources[irq]);
719 
720 	(*pic->pic_ops->pic_block_irqs)(pic, irq & ~0x1f, __BIT(irq & 0x1f));
721 	pic->pic_sources[irq] = NULL;
722 	pic__iplsources[pic_ipl_offset[is->is_ipl] + is->is_iplidx] = NULL;
723 	/*
724 	 * Now detach the per-cpu evcnts.
725 	 */
726 	percpu_foreach(pic->pic_percpu, pic_percpu_evcnt_deattach, is);
727 
728 	kmem_free(is, sizeof(*is));
729 }
730 
731 void *
732 intr_establish(int irq, int ipl, int type, int (*func)(void *), void *arg)
733 {
734 	KASSERT(!cpu_intr_p());
735 	KASSERT(!cpu_softintr_p());
736 
737 	for (size_t slot = 0; slot < PIC_MAXPICS; slot++) {
738 		struct pic_softc * const pic = pic_list[slot];
739 		if (pic == NULL || pic->pic_irqbase < 0)
740 			continue;
741 		if (pic->pic_irqbase <= irq
742 		    && irq < pic->pic_irqbase + pic->pic_maxsources) {
743 			return pic_establish_intr(pic, irq - pic->pic_irqbase,
744 			    ipl, type, func, arg);
745 		}
746 	}
747 
748 	return NULL;
749 }
750 
751 void
752 intr_disestablish(void *ih)
753 {
754 	struct intrsource * const is = ih;
755 
756 	KASSERT(!cpu_intr_p());
757 	KASSERT(!cpu_softintr_p());
758 
759 	pic_disestablish_source(is);
760 }
761