xref: /netbsd/sys/arch/evbmips/malta/pci/pcib.c (revision 66ff8ec6)
1 /*	$NetBSD: pcib.c,v 1.24 2022/01/22 15:10:31 skrll Exp $	*/
2 
3 /*
4  * Copyright 2002 Wasabi Systems, Inc.
5  * All rights reserved.
6  *
7  * Written by Simon Burge for Wasabi Systems, Inc.
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  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *      This product includes software developed for the NetBSD Project by
20  *      Wasabi Systems, Inc.
21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22  *    or promote products derived from this software without specific prior
23  *    written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35  * POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 #include <sys/cdefs.h>
39 __KERNEL_RCSID(0, "$NetBSD: pcib.c,v 1.24 2022/01/22 15:10:31 skrll Exp $");
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/kernel.h>
44 #include <sys/device.h>
45 #include <sys/kmem.h>
46 
47 #include <uvm/uvm_extern.h>
48 
49 #include <sys/bus.h>
50 #include <evbmips/malta/maltareg.h>
51 #include <evbmips/malta/maltavar.h>
52 #include <evbmips/malta/dev/gtreg.h>
53 #include <evbmips/malta/pci/pcibvar.h>
54 
55 #include <dev/isa/isareg.h>
56 #include <dev/isa/isavar.h>
57 
58 #include <dev/pci/pcireg.h>
59 #include <dev/pci/pcivar.h>
60 #include <dev/pci/pcidevs.h>
61 
62 #include <dev/ic/i8259reg.h>
63 
64 
65 #define	ICU_LEN		16	/* number of ISA IRQs */
66 
67 const char * const isa_intrnames[ICU_LEN] = {
68 	"timer",
69 	"keyboard",
70 	"reserved",		/* by South Bridge (for cascading) */
71 	"com1",
72 	"com0",
73 	"not used",
74 	"floppy",
75 	"centronics",
76 	"mcclock",
77 	"i2c",
78 	"pci A,B",		/* PCI slots 1..4, ethernet */
79 	"pci C,D",		/* PCI slots 1..4, audio, usb */
80 	"mouse",
81 	"reserved",
82 	"ide primary",
83 	"ide secondary",	/* and compact flash connector */
84 };
85 
86 struct pcib_intrhead {
87 	LIST_HEAD(, evbmips_intrhand) intr_q;
88 	struct evcnt intr_count;
89 	int intr_type;
90 };
91 
92 struct pcib_softc {
93 	device_t sc_dev;
94 
95 	bus_space_tag_t sc_memt;
96 	bus_space_tag_t sc_iot;
97 	bus_space_handle_t sc_ioh_icu1;
98 	bus_space_handle_t sc_ioh_icu2;
99 	bus_space_handle_t sc_ioh_elcr;
100 
101 	bus_dma_tag_t sc_dmat;
102 
103 	struct mips_isa_chipset sc_ic;
104 
105 	struct pcib_intrhead sc_intrtab[ICU_LEN];
106 
107 	u_int16_t	sc_imask;
108 	u_int16_t	sc_elcr;
109 
110 	u_int16_t	sc_reserved;
111 
112 	void *sc_ih;
113 };
114 
115 /*
116  * XXX
117  *	There is only one pci-isa bridge, and all external interrupts
118  *	are routed through it, so we need to remember the softc when
119  *	called from other interrupt handling code.
120  */
121 static struct pcib_softc *my_sc;
122 struct mips_isa_chipset *pcib_ic;
123 
124 static int	pcib_match(device_t, cfdata_t, void *);
125 static void	pcib_attach(device_t, device_t, void *);
126 static int	pcib_intr(void *v);
127 static void	pcib_bridge_callback(device_t);
128 static void	pcib_set_icus(struct pcib_softc *sc);
129 static void	pcib_cleanup(void *arg);
130 
131 static const struct evcnt *
132 		pcib_isa_intr_evcnt(void *, int);
133 static void	*pcib_isa_intr_establish(void *, int, int, int,
134 		    int (*)(void *), void *);
135 static void	pcib_isa_intr_disestablish(void *, void *);
136 static void	pcib_isa_attach_hook(device_t, device_t,
137 		    struct isabus_attach_args *);
138 static void	pcib_isa_detach_hook(isa_chipset_tag_t, device_t);
139 static int	pcib_isa_intr_alloc(void *, int, int, int *);
140 static const char *
141 		pcib_isa_intr_string(void *, int, char *, size_t);
142 
143 CFATTACH_DECL_NEW(pcib, sizeof(struct pcib_softc),
144     pcib_match, pcib_attach, NULL, NULL);
145 
146 static int
malta_isa_dma_may_bounce(bus_dma_tag_t t,bus_dmamap_t map,int flags,int * cookieflagsp)147 malta_isa_dma_may_bounce(bus_dma_tag_t t, bus_dmamap_t map, int flags,
148 	int *cookieflagsp)
149 {
150         if (((map->_dm_size / PAGE_SIZE) + 1) > map->_dm_segcnt)
151                 *cookieflagsp |= _BUS_DMA_MIGHT_NEED_BOUNCE;
152 
153 	return 0;
154 }
155 
156 static int
pcib_match(device_t parent,cfdata_t match,void * aux)157 pcib_match(device_t parent, cfdata_t match, void *aux)
158 {
159 	struct pci_attach_args *pa = aux;
160 
161 	if (PCI_CLASS(pa->pa_class) == PCI_CLASS_BRIDGE &&
162 	    PCI_SUBCLASS(pa->pa_class) == PCI_SUBCLASS_BRIDGE_ISA)
163 		return (1);
164 
165 	return (0);
166 }
167 
168 static void
pcib_attach(device_t parent,device_t self,void * aux)169 pcib_attach(device_t parent, device_t self, void *aux)
170 {
171 	struct pci_attach_args * const pa = aux;
172 	struct pcib_softc * const sc = device_private(self);
173 	const char * const xname = device_xname(self);
174 	char devinfo[256];
175 	int error;
176 
177 	printf("\n");
178 
179 	if (my_sc != NULL)
180 		panic("pcib_attach: already attached!");
181 	my_sc = sc;
182 	sc->sc_dev = self;
183 
184 	/*
185 	 * Just print out a description and defer configuration
186 	 * until all PCI devices have been attached.
187 	 */
188 	pci_devinfo(pa->pa_id, pa->pa_class, 0, devinfo, sizeof(devinfo));
189 	printf("%s: %s, (rev . 0x%02x)\n", xname, devinfo,
190 	    PCI_REVISION(pa->pa_class));
191 
192 	sc->sc_memt = pa->pa_memt;
193 	sc->sc_iot = pa->pa_iot;
194 
195 	/*
196 	 * Initialize the DMA tag used for ISA DMA.
197 	 */
198 	error = bus_dmatag_subregion(pa->pa_dmat, MALTA_DMA_ISA_PHYSBASE,
199 	    MALTA_DMA_ISA_PHYSBASE + MALTA_DMA_ISA_SIZE - 1, &sc->sc_dmat, 0);
200 	if (error)
201 		panic("malta_dma_init: failed to create ISA dma tag: %d",
202 		    error);
203 	sc->sc_dmat->_may_bounce = malta_isa_dma_may_bounce;
204 
205 	/*
206 	 * Map the PIC/ELCR registers.
207 	 */
208 	if (bus_space_map(sc->sc_iot, 0x4d0, 2, 0, &sc->sc_ioh_elcr) != 0)
209 		printf("%s: unable to map ELCR registers\n", xname);
210 	if (bus_space_map(sc->sc_iot, IO_ICU1, 2, 0, &sc->sc_ioh_icu1) != 0)
211 		printf("%s: unable to map ICU1 registers\n", xname);
212 	if (bus_space_map(sc->sc_iot, IO_ICU2, 2, 0, &sc->sc_ioh_icu2) != 0)
213 		printf("%s: unable to map ICU2 registers\n", xname);
214 
215 	/* All interrupts default to "masked off". */
216 	sc->sc_imask = 0xffff;
217 
218 	/* All interrupts default to edge-triggered. */
219 	sc->sc_elcr = 0;
220 
221 	/*
222 	 * Initialize the 8259s.
223 	 */
224 	/* reset, program device, 4 bytes */
225 	bus_space_write_1(sc->sc_iot, sc->sc_ioh_icu1, PIC_ICW1,
226 	    ICW1_SELECT | ICW1_IC4);
227 	bus_space_write_1(sc->sc_iot, sc->sc_ioh_icu1, PIC_ICW2,
228 	    ICW2_VECTOR(0)/*XXX*/);
229 	bus_space_write_1(sc->sc_iot, sc->sc_ioh_icu1, PIC_ICW3,
230 	    ICW3_CASCADE(2));
231 	bus_space_write_1(sc->sc_iot, sc->sc_ioh_icu1, PIC_ICW4,
232 	    ICW4_8086);
233 
234 	/* mask all interrupts */
235 	bus_space_write_1(sc->sc_iot, sc->sc_ioh_icu1, PIC_OCW1,
236 	    sc->sc_imask & 0xff);
237 
238 	/* enable special mask mode */
239 	bus_space_write_1(sc->sc_iot, sc->sc_ioh_icu1, PIC_OCW3,
240 	    OCW3_SELECT | OCW3_SSMM | OCW3_SMM);
241 
242 	/* read IRR by default */
243 	bus_space_write_1(sc->sc_iot, sc->sc_ioh_icu1, PIC_OCW3,
244 	    OCW3_SELECT | OCW3_RR);
245 
246 	/* reset, program device, 4 bytes */
247 	bus_space_write_1(sc->sc_iot, sc->sc_ioh_icu2, PIC_ICW1,
248 	    ICW1_SELECT | ICW1_IC4);
249 	bus_space_write_1(sc->sc_iot, sc->sc_ioh_icu2, PIC_ICW2,
250 	    ICW2_VECTOR(0)/*XXX*/);
251 	bus_space_write_1(sc->sc_iot, sc->sc_ioh_icu2, PIC_ICW3,
252 	    ICW3_CASCADE(2));
253 	bus_space_write_1(sc->sc_iot, sc->sc_ioh_icu2, PIC_ICW4,
254 	    ICW4_8086);
255 
256 	/* mask all interrupts */
257 	bus_space_write_1(sc->sc_iot, sc->sc_ioh_icu2, PIC_OCW1,
258 	    sc->sc_imask & 0xff);
259 
260 	/* enable special mask mode */
261 	bus_space_write_1(sc->sc_iot, sc->sc_ioh_icu2, PIC_OCW3,
262 	    OCW3_SELECT | OCW3_SSMM | OCW3_SMM);
263 
264 	/* read IRR by default */
265 	bus_space_write_1(sc->sc_iot, sc->sc_ioh_icu2, PIC_OCW3,
266 	    OCW3_SELECT | OCW3_RR);
267 
268 	/*
269 	 * Default all interrupts to edge-triggered.
270 	 */
271 	bus_space_write_1(sc->sc_iot, sc->sc_ioh_elcr, 0,
272 	    sc->sc_elcr & 0xff);
273 	bus_space_write_1(sc->sc_iot, sc->sc_ioh_elcr, 1,
274 	    (sc->sc_elcr >> 8) & 0xff);
275 
276 	/*
277 	 * Some ISA interrupts are reserved for devices that
278 	 * we know are hard-wired to certain IRQs.
279 	 */
280 	sc->sc_reserved =
281 		(1U << 0) |     /* timer */
282 		(1U << 1) |     /* keyboard controller (keyboard) */
283 		(1U << 2) |     /* PIC cascade */
284 		(1U << 3) |     /* COM 2 */
285 		(1U << 4) |     /* COM 1 */
286 		(1U << 6) |     /* floppy */
287 		(1U << 7) |     /* centronics */
288 		(1U << 8) |     /* RTC */
289 		(1U << 9) |	/* I2C */
290 		(1U << 12) |    /* keyboard controller (mouse) */
291 		(1U << 14) |    /* IDE primary */
292 		(1U << 15);     /* IDE secondary */
293 
294 	/* Set up our ISA chipset. */
295 	sc->sc_ic.ic_v = sc;
296 	sc->sc_ic.ic_intr_evcnt = pcib_isa_intr_evcnt;
297 	sc->sc_ic.ic_intr_establish = pcib_isa_intr_establish;
298 	sc->sc_ic.ic_intr_disestablish = pcib_isa_intr_disestablish;
299 	sc->sc_ic.ic_intr_alloc = pcib_isa_intr_alloc;
300 	sc->sc_ic.ic_intr_string = pcib_isa_intr_string;
301 
302 	pcib_ic = &sc->sc_ic;	/* XXX for external use */
303 
304 	/* Initialize our interrupt table. */
305 	for (size_t i = 0; i < ICU_LEN; i++) {
306 #if 0
307 		char irqstr[8];		/* 4 + 2 + NULL + sanity */
308 
309 		snprintf(irqstr, sizeof(irqstr), "irq %d", i);
310 		evcnt_attach_dynamic(&sc->sc_intrtab[i].intr_count,
311 		    EVCNT_TYPE_INTR, NULL, "pcib", irqstr);
312 #else
313 		evcnt_attach_dynamic(&sc->sc_intrtab[i].intr_count,
314 		    EVCNT_TYPE_INTR, NULL, "pcib", isa_intrnames[i]);
315 #endif
316 		LIST_INIT(&sc->sc_intrtab[i].intr_q);
317 		sc->sc_intrtab[i].intr_type = IST_NONE;
318 	}
319 
320 	/* Hook up our interrupt handler. */
321 	sc->sc_ih = evbmips_intr_establish(MALTA_SOUTHBRIDGE_INTR, pcib_intr, sc);
322 	if (sc->sc_ih == NULL)
323 		printf("%s: WARNING: unable to register interrupt handler\n",
324 		    xname);
325 
326 
327 	/*
328 	 * Disable ISA interrupts before returning to YAMON.
329 	 */
330 	if (shutdownhook_establish(pcib_cleanup, sc) == NULL)
331 		panic("pcib_attach: could not establish shutdown hook");
332 
333 	config_defer(self, pcib_bridge_callback);
334 }
335 
336 static void
pcib_bridge_callback(device_t self)337 pcib_bridge_callback(device_t self)
338 {
339 	struct pcib_softc *sc = device_private(self);
340 	struct isabus_attach_args iba;
341 
342 	/*
343 	 * Attach the ISA bus behind this bridge.
344 	 */
345 	memset(&iba, 0, sizeof(iba));
346 
347 	iba.iba_iot = sc->sc_iot;
348 	iba.iba_memt = sc->sc_memt;
349 	iba.iba_dmat = sc->sc_dmat;
350 
351 	iba.iba_ic = &sc->sc_ic;
352 	iba.iba_ic->ic_attach_hook = pcib_isa_attach_hook;
353 	iba.iba_ic->ic_detach_hook = pcib_isa_detach_hook;
354 
355 	config_found(self, &iba, isabusprint, CFARGS_NONE);
356 }
357 
358 static void
pcib_isa_attach_hook(device_t parent,device_t self,struct isabus_attach_args * iba)359 pcib_isa_attach_hook(device_t parent, device_t self,
360     struct isabus_attach_args *iba)
361 {
362 
363 	/* Nothing to do. */
364 }
365 
366 static void
pcib_isa_detach_hook(isa_chipset_tag_t ic,device_t self)367 pcib_isa_detach_hook(isa_chipset_tag_t ic, device_t self)
368 {
369 
370 	/* Nothing to do. */
371 }
372 
373 static void
pcib_set_icus(struct pcib_softc * sc)374 pcib_set_icus(struct pcib_softc *sc)
375 {
376 
377 	/* Enable the cascade IRQ (2) if 8-15 is enabled. */
378 	if ((sc->sc_imask & 0xff00) != 0xff00)
379 		sc->sc_imask &= ~(1U << 2);
380 	else
381 		sc->sc_imask |= (1U << 2);
382 
383 	bus_space_write_1(sc->sc_iot, sc->sc_ioh_icu1, PIC_OCW1,
384 	    sc->sc_imask & 0xff);
385 	bus_space_write_1(sc->sc_iot, sc->sc_ioh_icu2, PIC_OCW1,
386 	    (sc->sc_imask >> 8) & 0xff);
387 
388 	bus_space_write_1(sc->sc_iot, sc->sc_ioh_elcr, 0,
389 	    sc->sc_elcr & 0xff);
390 	bus_space_write_1(sc->sc_iot, sc->sc_ioh_elcr, 1,
391 	    (sc->sc_elcr >> 8) & 0xff);
392 }
393 
394 static int
pcib_intr(void * v)395 pcib_intr(void *v)
396 {
397 	struct pcib_softc *sc = v;
398 	struct evbmips_intrhand *ih;
399 	int irq;
400 
401 	for (;;) {
402 #if 1
403 		bus_space_write_1(sc->sc_iot, sc->sc_ioh_icu1, PIC_OCW3,
404 		    OCW3_SELECT | OCW3_POLL);
405 		irq = bus_space_read_1(sc->sc_iot, sc->sc_ioh_icu1, PIC_OCW3);
406 		if ((irq & OCW3_POLL_PENDING) == 0)
407 			return (1);
408 
409 		irq = OCW3_POLL_IRQ(irq);
410 
411 		if (irq == 2) {
412 			bus_space_write_1(sc->sc_iot, sc->sc_ioh_icu2,
413 			    PIC_OCW3, OCW3_SELECT | OCW3_POLL);
414 			irq = bus_space_read_1(sc->sc_iot, sc->sc_ioh_icu2,
415 			    PIC_OCW3);
416 			if (irq & OCW3_POLL_PENDING)
417 				irq = OCW3_POLL_IRQ(irq) + 8;
418 			else
419 				irq = 2;
420 		}
421 #else
422 		/* XXX - should be a function call to gt.c? */
423 		irq = GT_REGVAL(GT_PCI0_INTR_ACK) & 0xff;
424 
425 		/*
426 		 * From YAMON source code:
427 		 *
428 		 * IRQ7 is used to detect spurious interrupts.
429 		 * The interrupt acknowledge cycle returns IRQ7, if no
430 		 * interrupts is requested.
431 		 * We can differentiate between this situation and a
432 		 * "Normal" IRQ7 by reading the ISR.
433 		 */
434 
435 		if (irq == 7) {
436 			int reg;
437 
438 			bus_space_write_1(sc->sc_iot, sc->sc_ioh_icu1, PIC_OCW3,
439 			    OCW3_SELECT | OCW3_RR | OCW3_RIS);
440 			reg = bus_space_read_1(sc->sc_iot, sc->sc_ioh_icu1,
441 			    PIC_OCW3);
442 			if (!(reg & (1 << 7)))
443 				break;	/* spurious interrupt */
444 		}
445 #endif
446 
447 		sc->sc_intrtab[irq].intr_count.ev_count++;
448 		LIST_FOREACH(ih, &sc->sc_intrtab[irq].intr_q, ih_q)
449 			(*ih->ih_func)(ih->ih_arg);
450 
451 		/* Send a specific EOI to the 8259. */
452 		if (irq > 7) {
453 			bus_space_write_1(sc->sc_iot, sc->sc_ioh_icu2,
454 			    PIC_OCW2, OCW2_SELECT | OCW2_EOI | OCW2_SL |
455 			    OCW2_ILS(irq & 7));
456 			irq = 2;
457 		}
458 
459 		bus_space_write_1(sc->sc_iot, sc->sc_ioh_icu1, PIC_OCW2,
460 		    OCW2_SELECT | OCW2_EOI | OCW2_SL | OCW2_ILS(irq));
461 	}
462 }
463 
464 const char *
pcib_isa_intr_string(void * v,int irq,char * buf,size_t len)465 pcib_isa_intr_string(void *v, int irq, char *buf, size_t len)
466 {
467 	if (irq == 0 || irq >= ICU_LEN || irq == 2)
468 		panic("%s: bogus isa irq 0x%x", __func__, irq);
469 
470 	snprintf(buf, len, "isa irq %d", irq);
471 	return buf;
472 }
473 
474 const struct evcnt *
pcib_isa_intr_evcnt(void * v,int irq)475 pcib_isa_intr_evcnt(void *v, int irq)
476 {
477 
478 	if (irq == 0 || irq >= ICU_LEN || irq == 2)
479 		panic("pcib_isa_intr_evcnt: bogus isa irq 0x%x", irq);
480 
481 	return (&my_sc->sc_intrtab[irq].intr_count);
482 }
483 
484 void *
pcib_isa_intr_establish(void * v,int irq,int type,int level,int (* func)(void *),void * arg)485 pcib_isa_intr_establish(void *v, int irq, int type, int level,
486     int (*func)(void *), void *arg)
487 {
488 	struct evbmips_intrhand *ih;
489 	int s;
490 
491 	if (irq >= ICU_LEN || irq == 2 || type == IST_NONE)
492 		panic("pcib_isa_intr_establish: bad irq or type");
493 
494 	switch (my_sc->sc_intrtab[irq].intr_type) {
495 	case IST_NONE:
496 		my_sc->sc_intrtab[irq].intr_type = type;
497 		break;
498 
499 	case IST_EDGE:
500 	case IST_LEVEL:
501 		if (type == my_sc->sc_intrtab[irq].intr_type)
502 			break;
503 		/* FALLTHROUGH */
504 	case IST_PULSE:
505 		/*
506 		 * We can't share interrupts in this case.
507 		 */
508 		return (NULL);
509 	}
510 
511 	ih = kmem_alloc(sizeof(*ih), KM_SLEEP);
512 	ih->ih_func = func;
513 	ih->ih_arg = arg;
514 	ih->ih_irq = irq;
515 
516 	s = splhigh();
517 
518 	/* Insert the handler into the table. */
519 	LIST_INSERT_HEAD(&my_sc->sc_intrtab[irq].intr_q, ih, ih_q);
520 	my_sc->sc_intrtab[irq].intr_type = type;
521 
522 	/* Enable it, set trigger mode. */
523 	my_sc->sc_imask &= ~(1 << irq);
524 	if (my_sc->sc_intrtab[irq].intr_type == IST_LEVEL)
525 		my_sc->sc_elcr |= (1 << irq);
526 	else
527 		my_sc->sc_elcr &= ~(1 << irq);
528 
529 	pcib_set_icus(my_sc);
530 
531 	splx(s);
532 
533 	return (ih);
534 }
535 
536 void
pcib_isa_intr_disestablish(void * v,void * arg)537 pcib_isa_intr_disestablish(void *v, void *arg)
538 {
539 	struct evbmips_intrhand *ih = arg;
540 	int s;
541 
542 	s = splhigh();
543 
544 	LIST_REMOVE(ih, ih_q);
545 
546 	/* If there are no more handlers on this IRQ, disable it. */
547 	if (LIST_FIRST(&my_sc->sc_intrtab[ih->ih_irq].intr_q) == NULL) {
548 		my_sc->sc_imask |= (1 << ih->ih_irq);
549 		pcib_set_icus(my_sc);
550 	}
551 
552 	splx(s);
553 
554 	kmem_free(ih, sizeof(*ih));
555 }
556 
557 static int
pcib_isa_intr_alloc(void * v,int mask,int type,int * irq)558 pcib_isa_intr_alloc(void *v, int mask, int type, int *irq)
559 {
560 	int i, tmp, bestirq, count;
561 	struct evbmips_intrhand *ih;
562 
563 	if (type == IST_NONE)
564 		panic("pcib_intr_alloc: bogus type");
565 
566 	bestirq = -1;
567 	count = -1;
568 
569 	mask &= ~my_sc->sc_reserved;
570 
571 	for (i = 0; i < ICU_LEN; i++) {
572 		if ((mask & (1 << i)) == 0)
573 			continue;
574 
575 		switch (my_sc->sc_intrtab[i].intr_type) {
576 		case IST_NONE:
577 			/*
578 			 * If nothing's using the IRQ, just return it.
579 			 */
580 			*irq = i;
581 			return (0);
582 
583 		case IST_EDGE:
584 		case IST_LEVEL:
585 			if (type != my_sc->sc_intrtab[i].intr_type)
586 				continue;
587 			/*
588 			 * If the IRQ is sharable, count the number of
589 			 * other handlers, and if it's smaller than the
590 			 * last IRQ like this, remember it.
591 			 */
592 			tmp = 0;
593 			for (ih = LIST_FIRST(&my_sc->sc_intrtab[i].intr_q);
594 				ih != NULL; ih = LIST_NEXT(ih, ih_q))
595 			tmp++;
596 			if (bestirq == -1 || count > tmp) {
597 				bestirq = i;
598 				count = tmp;
599 			}
600 			break;
601 
602 		case IST_PULSE:
603 		/* This just isn't sharable. */
604 		continue;
605 		}
606 	}
607 
608 	if (bestirq == -1)
609 		return (1);
610 
611 	*irq = bestirq;
612 	return (0);
613 }
614 
615 static void
pcib_cleanup(void * arg)616 pcib_cleanup(void *arg)
617 {
618 
619 	my_sc->sc_imask = 0xffff;
620 	pcib_set_icus(my_sc);
621 }
622