1 /* $NetBSD: isabus.c,v 1.51 2020/11/18 02:14:13 thorpej Exp $ */ 2 /* $OpenBSD: isabus.c,v 1.15 1998/03/16 09:38:46 pefo Exp $ */ 3 /* NetBSD: isa.c,v 1.33 1995/06/28 04:30:51 cgd Exp */ 4 5 /*- 6 * Copyright (c) 1990 The Regents of the University of California. 7 * All rights reserved. 8 * 9 * This code is derived from software contributed to Berkeley by 10 * William Jolitz and Don Ahn. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. 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 * @(#)isa.c 7.2 (Berkeley) 5/12/91 37 */ 38 /*- 39 * Copyright (c) 1995 Per Fogelstrom 40 * Copyright (c) 1993, 1994 Charles M. Hannum. 41 * 42 * This code is derived from software contributed to Berkeley by 43 * William Jolitz and Don Ahn. 44 * 45 * Redistribution and use in source and binary forms, with or without 46 * modification, are permitted provided that the following conditions 47 * are met: 48 * 1. Redistributions of source code must retain the above copyright 49 * notice, this list of conditions and the following disclaimer. 50 * 2. Redistributions in binary form must reproduce the above copyright 51 * notice, this list of conditions and the following disclaimer in the 52 * documentation and/or other materials provided with the distribution. 53 * 3. All advertising materials mentioning features or use of this software 54 * must display the following acknowledgement: 55 * This product includes software developed by the University of 56 * California, Berkeley and its contributors. 57 * 4. Neither the name of the University nor the names of its contributors 58 * may be used to endorse or promote products derived from this software 59 * without specific prior written permission. 60 * 61 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 62 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 63 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 64 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 65 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 66 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 67 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 68 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 69 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 70 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 71 * SUCH DAMAGE. 72 * 73 * @(#)isa.c 7.2 (Berkeley) 5/12/91 74 */ 75 /* 76 * Mach Operating System 77 * Copyright (c) 1991,1990,1989 Carnegie Mellon University 78 * All Rights Reserved. 79 * 80 * Permission to use, copy, modify and distribute this software and its 81 * documentation is hereby granted, provided that both the copyright 82 * notice and this permission notice appear in all copies of the 83 * software, derivative works or modified versions, and any portions 84 * thereof, and that both notices appear in supporting documentation. 85 * 86 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 87 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 88 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 89 * 90 * Carnegie Mellon requests users of this software to return to 91 * 92 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 93 * School of Computer Science 94 * Carnegie Mellon University 95 * Pittsburgh PA 15213-3890 96 * 97 * any improvements or extensions that they make and grant Carnegie Mellon 98 * the rights to redistribute these changes. 99 */ 100 /* 101 Copyright 1988, 1989 by Intel Corporation, Santa Clara, California. 102 103 All Rights Reserved 104 105 Permission to use, copy, modify, and distribute this software and 106 its documentation for any purpose and without fee is hereby 107 granted, provided that the above copyright notice appears in all 108 copies and that both the copyright notice and this permission notice 109 appear in supporting documentation, and that the name of Intel 110 not be used in advertising or publicity pertaining to distribution 111 of the software without specific, written prior permission. 112 113 INTEL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE 114 INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, 115 IN NO EVENT SHALL INTEL BE LIABLE FOR ANY SPECIAL, INDIRECT, OR 116 CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 117 LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT, 118 NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION 119 WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 120 */ 121 122 #include <sys/cdefs.h> 123 __KERNEL_RCSID(0, "$NetBSD: isabus.c,v 1.51 2020/11/18 02:14:13 thorpej Exp $"); 124 125 #include <sys/param.h> 126 #include <sys/proc.h> 127 #include <sys/systm.h> 128 #include <sys/callout.h> 129 #include <sys/time.h> 130 #include <sys/kernel.h> 131 #include <sys/device.h> 132 #include <sys/kmem.h> 133 #include <sys/extent.h> 134 135 #include <uvm/uvm_extern.h> 136 137 #include <machine/cpu.h> 138 #include <machine/pio.h> 139 #include <machine/autoconf.h> 140 #include <machine/intr.h> 141 142 #include <mips/locore.h> 143 144 #include <dev/ic/i8253reg.h> 145 #include <dev/ic/i8259reg.h> 146 #include <dev/isa/isareg.h> 147 #include <dev/isa/isavar.h> 148 #include <arc/isa/isabrvar.h> 149 #include <arc/isa/spkrreg.h> 150 151 #include <arc/arc/timervar.h> 152 153 static int beeping; 154 static callout_t sysbeep_ch; 155 156 static long isa_mem_ex_storage[EXTENT_FIXED_STORAGE_SIZE(16) / sizeof(long)]; 157 static long isa_io_ex_storage[EXTENT_FIXED_STORAGE_SIZE(16) / sizeof(long)]; 158 159 #define IRQ_SLAVE 2 160 161 /* Definition of the driver for autoconfig. */ 162 static int isabrprint(void *, const char *); 163 164 extern struct arc_bus_space arc_bus_io, arc_bus_mem; 165 166 static void isabr_attach_hook(device_t , device_t, 167 struct isabus_attach_args *); 168 static void isabr_detach_hook(isa_chipset_tag_t, device_t); 169 static const struct evcnt *isabr_intr_evcnt(isa_chipset_tag_t, int); 170 static void *isabr_intr_establish(isa_chipset_tag_t, int, int, int, 171 int (*)(void *), void *); 172 static void isabr_intr_disestablish(isa_chipset_tag_t, void*); 173 static void isabr_initicu(void); 174 static void intr_calculatemasks(void); 175 static int fakeintr(void *a); 176 177 struct isabr_config *isabr_conf = NULL; 178 uint32_t imask[_IPL_N]; /* XXX */ 179 180 void 181 isabrattach(struct isabr_softc *sc) 182 { 183 struct isabus_attach_args iba; 184 185 callout_init(&sysbeep_ch, 0); 186 187 if (isabr_conf == NULL) 188 panic("isabr_conf isn't initialized"); 189 190 aprint_normal("\n"); 191 192 /* Initialize interrupt controller */ 193 isabr_initicu(); 194 195 sc->arc_isa_cs.ic_attach_hook = isabr_attach_hook; 196 sc->arc_isa_cs.ic_detach_hook = isabr_detach_hook; 197 sc->arc_isa_cs.ic_intr_evcnt = isabr_intr_evcnt; 198 sc->arc_isa_cs.ic_intr_establish = isabr_intr_establish; 199 sc->arc_isa_cs.ic_intr_disestablish = isabr_intr_disestablish; 200 201 arc_bus_space_init_extent(&arc_bus_mem, (void *)isa_mem_ex_storage, 202 sizeof(isa_mem_ex_storage)); 203 arc_bus_space_init_extent(&arc_bus_io, (void *)isa_io_ex_storage, 204 sizeof(isa_io_ex_storage)); 205 206 iba.iba_iot = &arc_bus_io; 207 iba.iba_memt = &arc_bus_mem; 208 iba.iba_dmat = &sc->sc_dmat; 209 iba.iba_ic = &sc->arc_isa_cs; 210 config_found_ia(sc->sc_dev, "isabus", &iba, isabrprint); 211 } 212 213 static int 214 isabrprint(void *aux, const char *pnp) 215 { 216 217 if (pnp) 218 aprint_normal("isa at %s", pnp); 219 aprint_verbose(" isa_io_base 0x%"PRIxVADDR" isa_mem_base 0x%"PRIxVADDR, 220 arc_bus_io.bs_vbase, arc_bus_mem.bs_vbase); 221 return UNCONF; 222 } 223 224 225 /* 226 * Interrupt system driver code 227 * ============================ 228 */ 229 #define LEGAL_IRQ(x) ((x) >= 0 && (x) < ICU_LEN && (x) != 2) 230 231 int imen; 232 int intrtype[ICU_LEN], intrmask[ICU_LEN], intrlevel[ICU_LEN]; 233 struct isa_intrhand *isa_intrhand[ICU_LEN]; 234 235 static int 236 fakeintr(void *a) 237 { 238 239 return 0; 240 } 241 242 /* 243 * Recalculate the interrupt masks from scratch. 244 * We could code special registry and deregistry versions of this function that 245 * would be faster, but the code would be nastier, and we don't expect this to 246 * happen very much anyway. 247 */ 248 static void 249 intr_calculatemasks(void) 250 { 251 int irq, level; 252 struct isa_intrhand *q; 253 254 /* First, figure out which levels each IRQ uses. */ 255 for (irq = 0; irq < ICU_LEN; irq++) { 256 int levels = 0; 257 for (q = isa_intrhand[irq]; q; q = q->ih_next) 258 levels |= 1 << q->ih_level; 259 intrlevel[irq] = levels; 260 } 261 262 /* Then figure out which IRQs use each level. */ 263 for (level = 0; level < _IPL_N; level++) { 264 int irqs = 0; 265 for (irq = 0; irq < ICU_LEN; irq++) 266 if (intrlevel[irq] & (1 << level)) 267 irqs |= 1 << irq; 268 imask[level] = irqs; 269 } 270 271 imask[IPL_NONE] = 0; 272 273 imask[IPL_SOFTCLOCK] |= imask[IPL_NONE]; 274 imask[IPL_SOFTNET] |= imask[IPL_SOFTCLOCK]; 275 276 /* 277 * Enforce a hierarchy that gives slow devices a better chance at not 278 * dropping data. 279 */ 280 imask[IPL_VM] |= imask[IPL_SOFTNET]; 281 282 /* 283 * Since run queues may be manipulated by both the statclock and tty, 284 * network, and diskdrivers, clock > tty. 285 */ 286 imask[IPL_SCHED] |= imask[IPL_VM]; 287 288 /* And eventually calculate the complete masks. */ 289 for (irq = 0; irq < ICU_LEN; irq++) { 290 int irqs = 1 << irq; 291 for (q = isa_intrhand[irq]; q; q = q->ih_next) 292 irqs |= imask[q->ih_level]; 293 intrmask[irq] = irqs; 294 } 295 296 /* Lastly, determine which IRQs are actually in use. */ 297 { 298 int irqs = 0; 299 for (irq = 0; irq < ICU_LEN; irq++) 300 if (isa_intrhand[irq]) 301 irqs |= 1 << irq; 302 if (irqs >= 0x100) /* any IRQs >= 8 in use */ 303 irqs |= 1 << IRQ_SLAVE; 304 imen = ~irqs; 305 isa_outb(IO_ICU1 + PIC_OCW1, imen); 306 isa_outb(IO_ICU2 + PIC_OCW1, imen >> 8); 307 } 308 } 309 310 static void 311 isabr_attach_hook(device_t parent, device_t self, 312 struct isabus_attach_args *iba) 313 { 314 315 /* Nothing to do. */ 316 } 317 318 static void 319 isabr_detach_hook(isa_chipset_tag_t ic, device_t self) 320 { 321 322 /* Nothing to do. */ 323 } 324 325 static const struct evcnt * 326 isabr_intr_evcnt(isa_chipset_tag_t ic, int irq) 327 { 328 329 /* XXX for now, no evcnt parent reported */ 330 return NULL; 331 } 332 333 /* 334 * Establish a ISA bus interrupt. 335 */ 336 static void * 337 isabr_intr_establish(isa_chipset_tag_t ic, int irq, int type, int level, 338 int (*ih_fun)(void *), void *ih_arg) 339 { 340 struct isa_intrhand **p, *q, *ih; 341 static struct isa_intrhand fakehand = {NULL, fakeintr}; 342 343 ih = kmem_alloc(sizeof *ih, KM_SLEEP); 344 345 if (!LEGAL_IRQ(irq) || type == IST_NONE) 346 panic("intr_establish: bogus irq or type"); 347 348 switch (intrtype[irq]) { 349 case IST_NONE: 350 intrtype[irq] = type; 351 break; 352 case IST_EDGE: 353 case IST_LEVEL: 354 if (type == intrtype[irq]) 355 break; 356 case IST_PULSE: 357 if (type != IST_NONE) 358 panic("intr_establish: can't share %s with %s", 359 isa_intr_typename(intrtype[irq]), 360 isa_intr_typename(type)); 361 break; 362 } 363 364 /* 365 * Figure out where to put the handler. 366 * This is O(N^2), but we want to preserve the order, and N is 367 * generally small. 368 */ 369 for (p = &isa_intrhand[irq]; (q = *p) != NULL; p = &q->ih_next) 370 ; 371 372 /* 373 * Actually install a fake handler momentarily, since we might be doing 374 * this with interrupts enabled and don't want the real routine called 375 * until masking is set up. 376 */ 377 fakehand.ih_level = level; 378 *p = &fakehand; 379 380 intr_calculatemasks(); 381 382 /* 383 * Poke the real handler in now. 384 */ 385 ih->ih_fun = ih_fun; 386 ih->ih_arg = ih_arg; 387 ih->ih_count = 0; 388 ih->ih_next = NULL; 389 ih->ih_level = level; 390 ih->ih_irq = irq; 391 snprintf(ih->ih_evname, sizeof(ih->ih_evname), "irq %d", irq); 392 evcnt_attach_dynamic(&ih->ih_evcnt, EVCNT_TYPE_INTR, NULL, "isa", 393 ih->ih_evname); 394 *p = ih; 395 396 return ih; 397 } 398 399 static void 400 isabr_intr_disestablish(isa_chipset_tag_t ic, void *arg) 401 { 402 403 } 404 405 /* 406 * Process an interrupt from the ISA bus. 407 */ 408 uint32_t 409 isabr_iointr(uint32_t mask, struct clockframe *cf) 410 { 411 struct isa_intrhand *ih; 412 int isa_vector; 413 int o_imen; 414 415 isa_vector = (*isabr_conf->ic_intr_status)(); 416 if (isa_vector < 0) 417 return 0; 418 419 o_imen = imen; 420 imen |= 1 << (isa_vector & (ICU_LEN - 1)); 421 if (isa_vector & 0x08) { 422 isa_inb(IO_ICU2 + PIC_OCW1); 423 isa_outb(IO_ICU2 + PIC_OCW1, imen >> 8); 424 isa_outb(IO_ICU2 + PIC_OCW2, 425 OCW2_SELECT | OCW2_EOI | OCW2_SL | 426 OCW2_ILS((isa_vector & 7))); 427 isa_outb(IO_ICU1, 428 OCW2_SELECT | OCW2_EOI | OCW2_SL | IRQ_SLAVE); 429 } else { 430 isa_inb(IO_ICU1 + PIC_OCW1); 431 isa_outb(IO_ICU1 + PIC_OCW1, imen); 432 isa_outb(IO_ICU1 + PIC_OCW2, 433 OCW2_SELECT | OCW2_EOI | OCW2_SL | OCW2_ILS(isa_vector)); 434 } 435 ih = isa_intrhand[isa_vector]; 436 if (isa_vector == 0 && ih) { /* Clock */ /*XXX*/ 437 last_cp0_count = mips3_cp0_count_read(); 438 /* XXX: spllowerclock() not allowed */ 439 cf->sr &= ~MIPS_SR_INT_IE; 440 if ((*ih->ih_fun)(cf)) 441 ih->ih_evcnt.ev_count++; 442 ih = ih->ih_next; 443 } 444 while (ih) { 445 if ((*ih->ih_fun)(ih->ih_arg)) 446 ih->ih_evcnt.ev_count++; 447 ih = ih->ih_next; 448 } 449 imen = o_imen; 450 isa_inb(IO_ICU1 + PIC_OCW1); 451 isa_inb(IO_ICU2 + PIC_OCW1); 452 isa_outb(IO_ICU1 + PIC_OCW1, imen); 453 isa_outb(IO_ICU2 + PIC_OCW1, imen >> 8); 454 455 return MIPS_INT_MASK_2; 456 } 457 458 459 /* 460 * Initialize the Interrupt controller logic. 461 */ 462 static void 463 isabr_initicu(void) 464 { 465 466 int i; 467 468 for (i = 0; i < ICU_LEN; i++) { 469 switch (i) { 470 case 2: 471 case 8: 472 intrtype[i] = IST_EDGE; 473 break; 474 default: 475 intrtype[i] = IST_NONE; 476 break; 477 } 478 } 479 480 /* reset; program device, four bytes */ 481 isa_outb(IO_ICU1 + PIC_ICW1, ICW1_SELECT | ICW1_IC4); 482 /* starting at this vector index */ 483 isa_outb(IO_ICU1 + PIC_ICW2, 0); 484 /* slave on line 2 */ 485 isa_outb(IO_ICU1 + PIC_ICW3, ICW3_CASCADE(IRQ_SLAVE)); 486 /* 8086 mode */ 487 isa_outb(IO_ICU1 + PIC_ICW4, ICW4_8086); 488 489 /* leave interrupts masked */ 490 isa_outb(IO_ICU1 + PIC_OCW1, 0xff); 491 492 /* special mask mode (if available) */ 493 isa_outb(IO_ICU1 + PIC_OCW3, OCW3_SELECT | OCW3_SSMM | OCW3_SMM); 494 /* Read IRR by default. */ 495 isa_outb(IO_ICU1 + PIC_OCW3, OCW3_SELECT | OCW3_RR); 496 #ifdef REORDER_IRQ 497 /* pri order 3-7, 0-2 (com2 first) */ 498 isa_outb(IO_ICU1 + PIC_OCW2, 499 OCW2_SELECT | OCW2_R | OCW2_SL OCW2_ILS(3 - 1)); 500 #endif 501 502 /* reset; program device, four bytes */ 503 isa_outb(IO_ICU2 + PIC_ICW1, ICW1_SELECT | ICW1_IC4); 504 /* staring at this vector index */ 505 isa_outb(IO_ICU2 + PIC_ICW2, 8); 506 /* slave connected to line 2 of master */ 507 isa_outb(IO_ICU2 + PIC_ICW3, ICW3_SIC(IRQ_SLAVE)); 508 /* 8086 mode */ 509 isa_outb(IO_ICU2 + PIC_ICW4, ICW4_8086); 510 511 /* leave interrupts masked */ 512 isa_outb(IO_ICU2 + PIC_OCW1, 0xff); 513 514 /* special mask mode (if available) */ 515 isa_outb(IO_ICU2 + PIC_OCW3, OCW3_SELECT | OCW3_SSMM | OCW3_SMM); 516 /* Read IRR by default. */ 517 isa_outb(IO_ICU2 + PIC_OCW3, OCW3_SELECT | OCW3_RR); 518 } 519 520 521 /* 522 * SPEAKER BEEPER... 523 */ 524 void 525 sysbeepstop(void *arg) 526 { 527 int s; 528 529 /* disable counter 2 */ 530 s = splhigh(); 531 isa_outb(PITAUX_PORT, isa_inb(PITAUX_PORT) & ~PIT_SPKR); 532 splx(s); 533 beeping = 0; 534 } 535 536 void 537 sysbeep(int pitch, int period) 538 { 539 static int last_pitch, last_period; 540 int s; 541 542 if (cold) 543 return; /* Can't beep yet. */ 544 545 if (beeping) 546 callout_stop(&sysbeep_ch); 547 if (!beeping || last_pitch != pitch) { 548 s = splhigh(); 549 isa_outb(IO_TIMER1 + TIMER_MODE, 550 TIMER_SEL2 | TIMER_16BIT | TIMER_SQWAVE); 551 isa_outb(IO_TIMER1 + TIMER_CNTR2, TIMER_DIV(pitch) % 256); 552 isa_outb(IO_TIMER1 + TIMER_CNTR2, TIMER_DIV(pitch) / 256); 553 isa_outb(PITAUX_PORT, isa_inb(PITAUX_PORT) | PIT_SPKR); 554 splx(s); 555 } 556 last_pitch = pitch; 557 beeping = last_period = period; 558 callout_reset(&sysbeep_ch, period, sysbeepstop, NULL); 559 } 560 561 int 562 isa_intr_alloc(isa_chipset_tag_t c, int mask, int type, int *irq_p) 563 { 564 int irq; 565 int maybe_irq = -1; 566 int shared_depth = 0; 567 mask &= 0x8b28; /* choose from 3, 5, 8, 9, 11, 15 XXX */ 568 for (irq = 0; mask != 0; mask >>= 1, irq++) { 569 if ((mask & 1) == 0) 570 continue; 571 if (intrtype[irq] == IST_NONE) { 572 *irq_p = irq; 573 return 0; 574 } 575 /* Level interrupts can be shared */ 576 if (type == IST_LEVEL && intrtype[irq] == IST_LEVEL) { 577 struct isa_intrhand *ih = isa_intrhand[irq]; 578 int depth; 579 if (maybe_irq == -1) { 580 maybe_irq = irq; 581 continue; 582 } 583 for (depth = 0; ih != NULL; ih = ih->ih_next) 584 depth++; 585 if (depth < shared_depth) { 586 maybe_irq = irq; 587 shared_depth = depth; 588 } 589 } 590 } 591 if (maybe_irq != -1) { 592 *irq_p = maybe_irq; 593 return 0; 594 } 595 return 1; 596 } 597