xref: /netbsd-src/sys/arch/arm/pic/pic.c (revision 50728e7823a76d5bd1a7bfa3a4eac400269b1339) 
1 /*	$NetBSD: pic.c,v 1.4 2008/12/30 05:43:14 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 #include <sys/cdefs.h>
31 __KERNEL_RCSID(0, "$NetBSD: pic.c,v 1.4 2008/12/30 05:43:14 matt Exp $");
32 
33 #define _INTR_PRIVATE
34 #include <sys/param.h>
35 #include <sys/evcnt.h>
36 #include <sys/atomic.h>
37 #include <sys/malloc.h>
38 #include <sys/mallocvar.h>
39 #include <sys/atomic.h>
40 
41 #include <arm/armreg.h>
42 #include <arm/cpu.h>
43 #include <arm/cpufunc.h>
44 
45 #include <arm/pic/picvar.h>
46 
47 MALLOC_DEFINE(M_INTRSOURCE, "intrsource", "interrupt source");
48 
49 static uint32_t
50 	pic_find_pending_irqs_by_ipl(struct pic_softc *, size_t, uint32_t, int);
51 static struct pic_softc *
52 	pic_list_find_pic_by_pending_ipl(uint32_t);
53 static void
54 	pic_deliver_irqs(struct pic_softc *, int, void *);
55 static void
56 	pic_list_deliver_irqs(register_t, int, void *);
57 
58 struct pic_softc *pic_list[PIC_MAXPICS];
59 #if PIC_MAXPICS > 32
60 #error PIC_MAXPICS > 32 not supported
61 #endif
62 volatile uint32_t pic_blocked_pics;
63 volatile uint32_t pic_pending_pics;
64 volatile uint32_t pic_pending_ipls;
65 struct intrsource *pic_sources[PIC_MAXMAXSOURCES];
66 struct intrsource *pic__iplsources[PIC_MAXMAXSOURCES];
67 struct intrsource **pic_iplsource[NIPL] = {
68 	[0 ... NIPL-1] = pic__iplsources,
69 };
70 size_t pic_ipl_offset[NIPL+1];
71 size_t pic_sourcebase;
72 static struct evcnt pic_deferral_ev =
73     EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, "deferred", "intr");
74 EVCNT_ATTACH_STATIC(pic_deferral_ev);
75 
76 
77 
78 int
79 pic_handle_intr(void *arg)
80 {
81 	struct pic_softc * const pic = arg;
82 	int rv;
83 
84 	rv = (*pic->pic_ops->pic_find_pending_irqs)(pic);
85 
86 	return rv > 0;
87 }
88 
89 void
90 pic_mark_pending_source(struct pic_softc *pic, struct intrsource *is)
91 {
92 	const uint32_t ipl_mask = __BIT(is->is_ipl);
93 
94 	atomic_or_32(&pic->pic_pending_irqs[is->is_irq >> 5],
95 	    __BIT(is->is_irq & 0x1f));
96 
97 	atomic_or_32(&pic->pic_pending_ipls, ipl_mask);
98 	atomic_or_32(&pic_pending_ipls, ipl_mask);
99 	atomic_or_32(&pic_pending_pics, __BIT(pic->pic_id));
100 }
101 
102 void
103 pic_mark_pending(struct pic_softc *pic, int irq)
104 {
105 	struct intrsource * const is = pic->pic_sources[irq];
106 
107 	KASSERT(irq < pic->pic_maxsources);
108 	KASSERT(is != NULL);
109 
110 	pic_mark_pending_source(pic, is);
111 }
112 
113 uint32_t
114 pic_mark_pending_sources(struct pic_softc *pic, size_t irq_base,
115 	uint32_t pending)
116 {
117 	struct intrsource ** const isbase = &pic->pic_sources[irq_base];
118 	struct intrsource *is;
119 	volatile uint32_t *ipending = &pic->pic_pending_irqs[irq_base >> 5];
120 	uint32_t ipl_mask = 0;
121 
122 	if (pending == 0)
123 		return ipl_mask;
124 
125 	KASSERT((irq_base & 31) == 0);
126 
127 	(*pic->pic_ops->pic_block_irqs)(pic, irq_base, pending);
128 
129 	atomic_or_32(ipending, pending);
130         while (pending != 0) {
131 		int n = ffs(pending);
132 		if (n-- == 0)
133 			break;
134 		is = isbase[n];
135 		KASSERT(is != NULL);
136 		KASSERT(irq_base <= is->is_irq && is->is_irq < irq_base + 32);
137 		pending &= ~__BIT(n);
138 		ipl_mask |= __BIT(is->is_ipl);
139 	}
140 
141 	atomic_or_32(&pic->pic_pending_ipls, ipl_mask);
142 	atomic_or_32(&pic_pending_ipls, ipl_mask);
143 	atomic_or_32(&pic_pending_pics, __BIT(pic->pic_id));
144 
145 	return ipl_mask;
146 }
147 
148 uint32_t
149 pic_find_pending_irqs_by_ipl(struct pic_softc *pic, size_t irq_base,
150 	uint32_t pending, int ipl)
151 {
152 	uint32_t ipl_irq_mask = 0;
153 	uint32_t irq_mask;
154 
155 	for (;;) {
156 		int irq = ffs(pending);
157 		if (irq-- == 0)
158 			return ipl_irq_mask;
159 
160 		irq_mask = __BIT(irq);
161 		KASSERT(pic->pic_sources[irq_base + irq] != NULL);
162 		if (pic->pic_sources[irq_base + irq]->is_ipl == ipl)
163 			ipl_irq_mask |= irq_mask;
164 
165 		pending &= ~irq_mask;
166 	}
167 }
168 
169 void
170 pic_dispatch(struct intrsource *is, void *frame)
171 {
172 	int rv;
173 
174 	if (__predict_false(is->is_arg == NULL)
175 	    && __predict_true(frame != NULL)) {
176 		rv = (*is->is_func)(frame);
177 	} else if (__predict_true(is->is_arg != NULL)) {
178 		rv = (*is->is_func)(is->is_arg);
179 	} else {
180 		pic_deferral_ev.ev_count++;
181 		return;
182 	}
183 	is->is_ev.ev_count++;
184 }
185 
186 void
187 pic_deliver_irqs(struct pic_softc *pic, int ipl, void *frame)
188 {
189 	const uint32_t ipl_mask = __BIT(ipl);
190 	struct intrsource *is;
191 	volatile uint32_t *ipending = pic->pic_pending_irqs;
192 	volatile uint32_t *iblocked = pic->pic_blocked_irqs;
193 	size_t irq_base;
194 #if PIC_MAXSOURCES > 32
195 	size_t irq_count;
196 #endif
197 	uint32_t pending_irqs;
198 	uint32_t blocked_irqs;
199 	int irq;
200 	bool progress = false;
201 
202 	KASSERT(pic->pic_pending_ipls & ipl_mask);
203 
204 	irq_base = 0;
205 #if PIC_MAXSOURCES > 32
206 	irq_count = 0;
207 #endif
208 
209 	for (;;) {
210 		pending_irqs = pic_find_pending_irqs_by_ipl(pic, irq_base,
211 		    *ipending, ipl);
212 		KASSERT((pending_irqs & *ipending) == pending_irqs);
213 		KASSERT((pending_irqs & ~(*ipending)) == 0);
214 		if (pending_irqs == 0) {
215 #if PIC_MAXSOURCES > 32
216 			irq_count += 32;
217 			if (__predict_true(irq_count >= pic->pic_maxsources))
218 				break;
219 			irq_base += 32;
220 			ipending++;
221 			iblocked++;
222 			if (irq_base >= pic->pic_maxsources) {
223 				ipending = pic->pic_pending_irqs;
224 				iblocked = pic->pic_blocked_irqs;
225 			}
226 			continue;
227 #else
228 			break;
229 #endif
230 		}
231 		progress = true;
232 		blocked_irqs = pending_irqs;
233 		do {
234 			irq = ffs(pending_irqs) - 1;
235 			KASSERT(irq >= 0);
236 
237 			atomic_and_32(ipending, ~__BIT(irq));
238 			is = pic->pic_sources[irq_base + irq];
239 			if (is != NULL) {
240 				cpsie(I32_bit);
241 				pic_dispatch(is, frame);
242 				cpsid(I32_bit);
243 			} else {
244 				KASSERT(0);
245 				blocked_irqs &= ~__BIT(irq);
246 			}
247 			pending_irqs = pic_find_pending_irqs_by_ipl(pic,
248 			    irq_base, *ipending, ipl);
249 		} while (pending_irqs);
250 		if (blocked_irqs) {
251 			atomic_or_32(iblocked, blocked_irqs);
252 			atomic_or_32(&pic_blocked_pics, __BIT(pic->pic_id));
253 		}
254 	}
255 
256 	KASSERT(progress);
257 	/*
258 	 * Since interrupts are disabled, we don't have to be too careful
259 	 * about these.
260 	 */
261 	if (atomic_and_32_nv(&pic->pic_pending_ipls, ~ipl_mask) == 0)
262 		atomic_and_32(&pic_pending_pics, ~__BIT(pic->pic_id));
263 }
264 
265 static void
266 pic_list_unblock_irqs(void)
267 {
268 	uint32_t blocked_pics = pic_blocked_pics;
269 
270 	pic_blocked_pics = 0;
271 	for (;;) {
272 		struct pic_softc *pic;
273 #if PIC_MAXSOURCES > 32
274 		volatile uint32_t *iblocked;
275 		uint32_t blocked;
276 		size_t irq_base;
277 #endif
278 
279 		int pic_id = ffs(blocked_pics);
280 		if (pic_id-- == 0)
281 			return;
282 
283 		pic = pic_list[pic_id];
284 		KASSERT(pic != NULL);
285 #if PIC_MAXSOURCES > 32
286 		for (irq_base = 0, iblocked = pic->pic_blocked_irqs;
287 		     irq_base < pic->pic_maxsources;
288 		     irq_base += 32, iblocked++) {
289 			if ((blocked = *iblocked) != 0) {
290 				(*pic->pic_ops->pic_unblock_irqs)(pic,
291 				    irq_base, blocked);
292 				atomic_and_32(iblocked, ~blocked);
293 			}
294 		}
295 #else
296 		KASSERT(pic->pic_blocked_irqs[0] != 0);
297 		(*pic->pic_ops->pic_unblock_irqs)(pic,
298 		    0, pic->pic_blocked_irqs[0]);
299 		pic->pic_blocked_irqs[0] = 0;
300 #endif
301 		blocked_pics &= ~__BIT(pic_id);
302 	}
303 }
304 
305 
306 struct pic_softc *
307 pic_list_find_pic_by_pending_ipl(uint32_t ipl_mask)
308 {
309 	uint32_t pending_pics = pic_pending_pics;
310 	struct pic_softc *pic;
311 
312 	for (;;) {
313 		int pic_id = ffs(pending_pics);
314 		if (pic_id-- == 0)
315 			return NULL;
316 
317 		pic = pic_list[pic_id];
318 		KASSERT(pic != NULL);
319 		if (pic->pic_pending_ipls & ipl_mask)
320 			return pic;
321 		pending_pics &= ~__BIT(pic_id);
322 	}
323 }
324 
325 void
326 pic_list_deliver_irqs(register_t psw, int ipl, void *frame)
327 {
328 	const uint32_t ipl_mask = __BIT(ipl);
329 	struct pic_softc *pic;
330 
331 	while ((pic = pic_list_find_pic_by_pending_ipl(ipl_mask)) != NULL) {
332 		pic_deliver_irqs(pic, ipl, frame);
333 		KASSERT((pic->pic_pending_ipls & ipl_mask) == 0);
334 	}
335 	atomic_and_32(&pic_pending_ipls, ~ipl_mask);
336 }
337 
338 void
339 pic_do_pending_ints(register_t psw, int newipl, void *frame)
340 {
341 	struct cpu_info * const ci = curcpu();
342 	if (__predict_false(newipl == IPL_HIGH))
343 		return;
344 	while ((pic_pending_ipls & ~__BIT(newipl)) > __BIT(newipl)) {
345 		KASSERT(pic_pending_ipls < __BIT(NIPL));
346 		for (;;) {
347 			int ipl = 31 - __builtin_clz(pic_pending_ipls);
348 			KASSERT(ipl < NIPL);
349 			if (ipl <= newipl)
350 				break;
351 
352 			ci->ci_cpl = ipl;
353 			pic_list_deliver_irqs(psw, ipl, frame);
354 			pic_list_unblock_irqs();
355 		}
356 	}
357 	if (ci->ci_cpl != newipl)
358 		ci->ci_cpl = newipl;
359 #ifdef __HAVE_FAST_SOFTINTS
360 	cpu_dosoftints();
361 #endif
362 }
363 
364 void
365 pic_add(struct pic_softc *pic, int irqbase)
366 {
367 	int slot, maybe_slot = -1;
368 
369 	for (slot = 0; slot < PIC_MAXPICS; slot++) {
370 		struct pic_softc * const xpic = pic_list[slot];
371 		if (xpic == NULL) {
372 			if (maybe_slot < 0)
373 				maybe_slot = slot;
374 			if (irqbase < 0)
375 				break;
376 			continue;
377 		}
378 		if (irqbase < 0 || xpic->pic_irqbase < 0)
379 			continue;
380 		if (irqbase >= xpic->pic_irqbase + xpic->pic_maxsources)
381 			continue;
382 		if (irqbase + pic->pic_maxsources <= xpic->pic_irqbase)
383 			continue;
384 		panic("pic_add: pic %s (%zu sources @ irq %u) conflicts"
385 		    " with pic %s (%zu sources @ irq %u)",
386 		    pic->pic_name, pic->pic_maxsources, irqbase,
387 		    xpic->pic_name, xpic->pic_maxsources, xpic->pic_irqbase);
388 	}
389 	slot = maybe_slot;
390 #if 0
391 	printf("%s: pic_sourcebase=%zu pic_maxsources=%zu\n",
392 	    pic->pic_name, pic_sourcebase, pic->pic_maxsources);
393 #endif
394 	KASSERT(pic_sourcebase + pic->pic_maxsources <= PIC_MAXMAXSOURCES);
395 
396 	pic->pic_sources = &pic_sources[pic_sourcebase];
397 	pic->pic_irqbase = irqbase;
398 	pic_sourcebase += pic->pic_maxsources;
399 	pic->pic_id = slot;
400 	pic_list[slot] = pic;
401 }
402 
403 int
404 pic_alloc_irq(struct pic_softc *pic)
405 {
406 	int irq;
407 
408 	for (irq = 0; irq < pic->pic_maxsources; irq++) {
409 		if (pic->pic_sources[irq] == NULL)
410 			return irq;
411 	}
412 
413 	return -1;
414 }
415 
416 void *
417 pic_establish_intr(struct pic_softc *pic, int irq, int ipl, int type,
418 	int (*func)(void *), void *arg)
419 {
420 	struct intrsource *is;
421 	int off, nipl;
422 
423 	if (pic->pic_sources[irq]) {
424 		printf("pic_establish_intr: pic %s irq %d already present\n",
425 		    pic->pic_name, irq);
426 		return NULL;
427 	}
428 
429 	is = malloc(sizeof(*is), M_INTRSOURCE, M_NOWAIT|M_ZERO);
430 	if (is == NULL)
431 		return NULL;
432 
433 	is->is_pic = pic;
434 	is->is_irq = irq;
435 	is->is_ipl = ipl;
436 	is->is_type = type;
437 	is->is_func = func;
438 	is->is_arg = arg;
439 
440 	if (pic->pic_ops->pic_source_name)
441 		(*pic->pic_ops->pic_source_name)(pic, irq, is->is_source,
442 		    sizeof(is->is_source));
443 	else
444 		snprintf(is->is_source, sizeof(is->is_source), "irq %d", irq);
445 
446 	evcnt_attach_dynamic(&is->is_ev, EVCNT_TYPE_INTR, NULL,
447 	    pic->pic_name, is->is_source);
448 
449 	pic->pic_sources[irq] = is;
450 
451 	/*
452 	 * First try to use an existing slot which is empty.
453 	 */
454 	for (off = pic_ipl_offset[ipl]; off < pic_ipl_offset[ipl+1]; off++) {
455 		if (pic__iplsources[off] == NULL) {
456 			is->is_iplidx = off - pic_ipl_offset[ipl];
457 			pic__iplsources[off] = is;
458 			return is;
459 		}
460 	}
461 
462 	/*
463 	 * Move up all the sources by one.
464  	 */
465 	if (ipl < NIPL) {
466 		off = pic_ipl_offset[ipl+1];
467 		memmove(&pic__iplsources[off+1], &pic__iplsources[off],
468 		    sizeof(pic__iplsources[0]) * (pic_ipl_offset[NIPL] - off));
469 	}
470 
471 	/*
472 	 * Advance the offset of all IPLs higher than this.  Include an
473 	 * extra one as well.  Thus the number of sources per ipl is
474 	 * pic_ipl_offset[ipl+1] - pic_ipl_offset[ipl].
475 	 */
476 	for (nipl = ipl + 1; nipl <= NIPL; nipl++)
477 		pic_ipl_offset[nipl]++;
478 
479 	/*
480 	 * Insert into the previously made position at the end of this IPL's
481 	 * sources.
482 	 */
483 	off = pic_ipl_offset[ipl + 1] - 1;
484 	is->is_iplidx = off - pic_ipl_offset[ipl];
485 	pic__iplsources[off] = is;
486 
487 	(*pic->pic_ops->pic_establish_irq)(pic, is);
488 
489 	(*pic->pic_ops->pic_unblock_irqs)(pic, is->is_irq & ~0x1f,
490 	    __BIT(is->is_irq & 0x1f));
491 
492 	/* We're done. */
493 	return is;
494 }
495 
496 void
497 pic_disestablish_source(struct intrsource *is)
498 {
499 	struct pic_softc * const pic = is->is_pic;
500 	const int irq = is->is_irq;
501 
502 	(*pic->pic_ops->pic_block_irqs)(pic, irq & ~31, __BIT(irq));
503 	pic->pic_sources[irq] = NULL;
504 	pic__iplsources[pic_ipl_offset[is->is_ipl] + is->is_iplidx] = NULL;
505 	evcnt_detach(&is->is_ev);
506 
507 	free(is, M_INTRSOURCE);
508 }
509 
510 int
511 _splraise(int newipl)
512 {
513 	struct cpu_info * const ci = curcpu();
514 	const int oldipl = ci->ci_cpl;
515 	KASSERT(newipl < NIPL);
516 	if (newipl > ci->ci_cpl)
517 		ci->ci_cpl = newipl;
518 	return oldipl;
519 }
520 int
521 _spllower(int newipl)
522 {
523 	struct cpu_info * const ci = curcpu();
524 	const int oldipl = ci->ci_cpl;
525 	KASSERT(panicstr || newipl <= ci->ci_cpl);
526 	if (newipl < ci->ci_cpl) {
527 		register_t psw = disable_interrupts(I32_bit);
528 		pic_do_pending_ints(psw, newipl, NULL);
529 		restore_interrupts(psw);
530 	}
531 	return oldipl;
532 }
533 
534 void
535 splx(int savedipl)
536 {
537 	struct cpu_info * const ci = curcpu();
538 	KASSERT(savedipl < NIPL);
539 	if (savedipl < ci->ci_cpl) {
540 		register_t psw = disable_interrupts(I32_bit);
541 		pic_do_pending_ints(psw, savedipl, NULL);
542 		restore_interrupts(psw);
543 	}
544 	ci->ci_cpl = savedipl;
545 }
546 
547 void *
548 intr_establish(int irq, int ipl, int type, int (*func)(void *), void *arg)
549 {
550 	int slot;
551 
552 	for (slot = 0; slot < PIC_MAXPICS; slot++) {
553 		struct pic_softc * const pic = pic_list[slot];
554 		if (pic == NULL || pic->pic_irqbase < 0)
555 			continue;
556 		if (pic->pic_irqbase <= irq
557 		    && irq < pic->pic_irqbase + pic->pic_maxsources) {
558 			return pic_establish_intr(pic, irq - pic->pic_irqbase,
559 			    ipl, type, func, arg);
560 		}
561 	}
562 
563 	return NULL;
564 }
565 
566 void
567 intr_disestablish(void *ih)
568 {
569 	struct intrsource * const is = ih;
570 	pic_disestablish_source(is);
571 }
572