1 /* 2 * linux/arch/arm/kernel/irq.c 3 * 4 * Copyright (C) 1992 Linus Torvalds 5 * Modifications for ARM processor Copyright (C) 1995-2000 Russell King. 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 * 11 * This file contains the code used by various IRQ handling routines: 12 * asking for different IRQ's should be done through these routines 13 * instead of just grabbing them. Thus setups with different IRQ numbers 14 * shouldn't result in any weird surprises, and installing new handlers 15 * should be easier. 16 * 17 * IRQ's are in fact implemented a bit like signal handlers for the kernel. 18 * Naturally it's not a 1:1 relation, but there are similarities. 19 */ 20 #include <linux/config.h> 21 #include <linux/kernel_stat.h> 22 #include <linux/module.h> 23 #include <linux/signal.h> 24 #include <linux/ioport.h> 25 #include <linux/interrupt.h> 26 #include <linux/ptrace.h> 27 #include <linux/slab.h> 28 #include <linux/random.h> 29 #include <linux/smp.h> 30 #include <linux/init.h> 31 #include <linux/seq_file.h> 32 #include <linux/errno.h> 33 #include <linux/list.h> 34 #include <linux/kallsyms.h> 35 #include <linux/proc_fs.h> 36 37 #include <asm/irq.h> 38 #include <asm/system.h> 39 #include <asm/mach/irq.h> 40 41 /* 42 * Maximum IRQ count. Currently, this is arbitary. However, it should 43 * not be set too low to prevent false triggering. Conversely, if it 44 * is set too high, then you could miss a stuck IRQ. 45 * 46 * Maybe we ought to set a timer and re-enable the IRQ at a later time? 47 */ 48 #define MAX_IRQ_CNT 100000 49 50 static int noirqdebug; 51 static volatile unsigned long irq_err_count; 52 static DEFINE_SPINLOCK(irq_controller_lock); 53 static LIST_HEAD(irq_pending); 54 55 struct irqdesc irq_desc[NR_IRQS]; 56 void (*init_arch_irq)(void) __initdata = NULL; 57 58 /* 59 * No architecture-specific irq_finish function defined in arm/arch/irqs.h. 60 */ 61 #ifndef irq_finish 62 #define irq_finish(irq) do { } while (0) 63 #endif 64 65 /* 66 * Dummy mask/unmask handler 67 */ 68 void dummy_mask_unmask_irq(unsigned int irq) 69 { 70 } 71 72 irqreturn_t no_action(int irq, void *dev_id, struct pt_regs *regs) 73 { 74 return IRQ_NONE; 75 } 76 77 void do_bad_IRQ(unsigned int irq, struct irqdesc *desc, struct pt_regs *regs) 78 { 79 irq_err_count += 1; 80 printk(KERN_ERR "IRQ: spurious interrupt %d\n", irq); 81 } 82 83 static struct irqchip bad_chip = { 84 .ack = dummy_mask_unmask_irq, 85 .mask = dummy_mask_unmask_irq, 86 .unmask = dummy_mask_unmask_irq, 87 }; 88 89 static struct irqdesc bad_irq_desc = { 90 .chip = &bad_chip, 91 .handle = do_bad_IRQ, 92 .pend = LIST_HEAD_INIT(bad_irq_desc.pend), 93 .disable_depth = 1, 94 }; 95 96 #ifdef CONFIG_SMP 97 void synchronize_irq(unsigned int irq) 98 { 99 struct irqdesc *desc = irq_desc + irq; 100 101 while (desc->running) 102 barrier(); 103 } 104 EXPORT_SYMBOL(synchronize_irq); 105 106 #define smp_set_running(desc) do { desc->running = 1; } while (0) 107 #define smp_clear_running(desc) do { desc->running = 0; } while (0) 108 #else 109 #define smp_set_running(desc) do { } while (0) 110 #define smp_clear_running(desc) do { } while (0) 111 #endif 112 113 /** 114 * disable_irq_nosync - disable an irq without waiting 115 * @irq: Interrupt to disable 116 * 117 * Disable the selected interrupt line. Enables and disables 118 * are nested. We do this lazily. 119 * 120 * This function may be called from IRQ context. 121 */ 122 void disable_irq_nosync(unsigned int irq) 123 { 124 struct irqdesc *desc = irq_desc + irq; 125 unsigned long flags; 126 127 spin_lock_irqsave(&irq_controller_lock, flags); 128 desc->disable_depth++; 129 list_del_init(&desc->pend); 130 spin_unlock_irqrestore(&irq_controller_lock, flags); 131 } 132 EXPORT_SYMBOL(disable_irq_nosync); 133 134 /** 135 * disable_irq - disable an irq and wait for completion 136 * @irq: Interrupt to disable 137 * 138 * Disable the selected interrupt line. Enables and disables 139 * are nested. This functions waits for any pending IRQ 140 * handlers for this interrupt to complete before returning. 141 * If you use this function while holding a resource the IRQ 142 * handler may need you will deadlock. 143 * 144 * This function may be called - with care - from IRQ context. 145 */ 146 void disable_irq(unsigned int irq) 147 { 148 struct irqdesc *desc = irq_desc + irq; 149 150 disable_irq_nosync(irq); 151 if (desc->action) 152 synchronize_irq(irq); 153 } 154 EXPORT_SYMBOL(disable_irq); 155 156 /** 157 * enable_irq - enable interrupt handling on an irq 158 * @irq: Interrupt to enable 159 * 160 * Re-enables the processing of interrupts on this IRQ line. 161 * Note that this may call the interrupt handler, so you may 162 * get unexpected results if you hold IRQs disabled. 163 * 164 * This function may be called from IRQ context. 165 */ 166 void enable_irq(unsigned int irq) 167 { 168 struct irqdesc *desc = irq_desc + irq; 169 unsigned long flags; 170 171 spin_lock_irqsave(&irq_controller_lock, flags); 172 if (unlikely(!desc->disable_depth)) { 173 printk("enable_irq(%u) unbalanced from %p\n", irq, 174 __builtin_return_address(0)); 175 } else if (!--desc->disable_depth) { 176 desc->probing = 0; 177 desc->chip->unmask(irq); 178 179 /* 180 * If the interrupt is waiting to be processed, 181 * try to re-run it. We can't directly run it 182 * from here since the caller might be in an 183 * interrupt-protected region. 184 */ 185 if (desc->pending && list_empty(&desc->pend)) { 186 desc->pending = 0; 187 if (!desc->chip->retrigger || 188 desc->chip->retrigger(irq)) 189 list_add(&desc->pend, &irq_pending); 190 } 191 } 192 spin_unlock_irqrestore(&irq_controller_lock, flags); 193 } 194 EXPORT_SYMBOL(enable_irq); 195 196 /* 197 * Enable wake on selected irq 198 */ 199 void enable_irq_wake(unsigned int irq) 200 { 201 struct irqdesc *desc = irq_desc + irq; 202 unsigned long flags; 203 204 spin_lock_irqsave(&irq_controller_lock, flags); 205 if (desc->chip->wake) 206 desc->chip->wake(irq, 1); 207 spin_unlock_irqrestore(&irq_controller_lock, flags); 208 } 209 EXPORT_SYMBOL(enable_irq_wake); 210 211 void disable_irq_wake(unsigned int irq) 212 { 213 struct irqdesc *desc = irq_desc + irq; 214 unsigned long flags; 215 216 spin_lock_irqsave(&irq_controller_lock, flags); 217 if (desc->chip->wake) 218 desc->chip->wake(irq, 0); 219 spin_unlock_irqrestore(&irq_controller_lock, flags); 220 } 221 EXPORT_SYMBOL(disable_irq_wake); 222 223 int show_interrupts(struct seq_file *p, void *v) 224 { 225 int i = *(loff_t *) v, cpu; 226 struct irqaction * action; 227 unsigned long flags; 228 229 if (i == 0) { 230 char cpuname[12]; 231 232 seq_printf(p, " "); 233 for_each_present_cpu(cpu) { 234 sprintf(cpuname, "CPU%d", cpu); 235 seq_printf(p, " %10s", cpuname); 236 } 237 seq_putc(p, '\n'); 238 } 239 240 if (i < NR_IRQS) { 241 spin_lock_irqsave(&irq_controller_lock, flags); 242 action = irq_desc[i].action; 243 if (!action) 244 goto unlock; 245 246 seq_printf(p, "%3d: ", i); 247 for_each_present_cpu(cpu) 248 seq_printf(p, "%10u ", kstat_cpu(cpu).irqs[i]); 249 seq_printf(p, " %s", action->name); 250 for (action = action->next; action; action = action->next) 251 seq_printf(p, ", %s", action->name); 252 253 seq_putc(p, '\n'); 254 unlock: 255 spin_unlock_irqrestore(&irq_controller_lock, flags); 256 } else if (i == NR_IRQS) { 257 #ifdef CONFIG_ARCH_ACORN 258 show_fiq_list(p, v); 259 #endif 260 #ifdef CONFIG_SMP 261 show_ipi_list(p); 262 #endif 263 seq_printf(p, "Err: %10lu\n", irq_err_count); 264 } 265 return 0; 266 } 267 268 /* 269 * IRQ lock detection. 270 * 271 * Hopefully, this should get us out of a few locked situations. 272 * However, it may take a while for this to happen, since we need 273 * a large number if IRQs to appear in the same jiffie with the 274 * same instruction pointer (or within 2 instructions). 275 */ 276 static int check_irq_lock(struct irqdesc *desc, int irq, struct pt_regs *regs) 277 { 278 unsigned long instr_ptr = instruction_pointer(regs); 279 280 if (desc->lck_jif == jiffies && 281 desc->lck_pc >= instr_ptr && desc->lck_pc < instr_ptr + 8) { 282 desc->lck_cnt += 1; 283 284 if (desc->lck_cnt > MAX_IRQ_CNT) { 285 printk(KERN_ERR "IRQ LOCK: IRQ%d is locking the system, disabled\n", irq); 286 return 1; 287 } 288 } else { 289 desc->lck_cnt = 0; 290 desc->lck_pc = instruction_pointer(regs); 291 desc->lck_jif = jiffies; 292 } 293 return 0; 294 } 295 296 static void 297 report_bad_irq(unsigned int irq, struct pt_regs *regs, struct irqdesc *desc, int ret) 298 { 299 static int count = 100; 300 struct irqaction *action; 301 302 if (!count || noirqdebug) 303 return; 304 305 count--; 306 307 if (ret != IRQ_HANDLED && ret != IRQ_NONE) { 308 printk("irq%u: bogus retval mask %x\n", irq, ret); 309 } else { 310 printk("irq%u: nobody cared\n", irq); 311 } 312 show_regs(regs); 313 dump_stack(); 314 printk(KERN_ERR "handlers:"); 315 action = desc->action; 316 do { 317 printk("\n" KERN_ERR "[<%p>]", action->handler); 318 print_symbol(" (%s)", (unsigned long)action->handler); 319 action = action->next; 320 } while (action); 321 printk("\n"); 322 } 323 324 static int 325 __do_irq(unsigned int irq, struct irqaction *action, struct pt_regs *regs) 326 { 327 unsigned int status; 328 int ret, retval = 0; 329 330 spin_unlock(&irq_controller_lock); 331 332 if (!(action->flags & SA_INTERRUPT)) 333 local_irq_enable(); 334 335 status = 0; 336 do { 337 ret = action->handler(irq, action->dev_id, regs); 338 if (ret == IRQ_HANDLED) 339 status |= action->flags; 340 retval |= ret; 341 action = action->next; 342 } while (action); 343 344 if (status & SA_SAMPLE_RANDOM) 345 add_interrupt_randomness(irq); 346 347 spin_lock_irq(&irq_controller_lock); 348 349 return retval; 350 } 351 352 /* 353 * This is for software-decoded IRQs. The caller is expected to 354 * handle the ack, clear, mask and unmask issues. 355 */ 356 void 357 do_simple_IRQ(unsigned int irq, struct irqdesc *desc, struct pt_regs *regs) 358 { 359 struct irqaction *action; 360 const unsigned int cpu = smp_processor_id(); 361 362 desc->triggered = 1; 363 364 kstat_cpu(cpu).irqs[irq]++; 365 366 smp_set_running(desc); 367 368 action = desc->action; 369 if (action) { 370 int ret = __do_irq(irq, action, regs); 371 if (ret != IRQ_HANDLED) 372 report_bad_irq(irq, regs, desc, ret); 373 } 374 375 smp_clear_running(desc); 376 } 377 378 /* 379 * Most edge-triggered IRQ implementations seem to take a broken 380 * approach to this. Hence the complexity. 381 */ 382 void 383 do_edge_IRQ(unsigned int irq, struct irqdesc *desc, struct pt_regs *regs) 384 { 385 const unsigned int cpu = smp_processor_id(); 386 387 desc->triggered = 1; 388 389 /* 390 * If we're currently running this IRQ, or its disabled, 391 * we shouldn't process the IRQ. Instead, turn on the 392 * hardware masks. 393 */ 394 if (unlikely(desc->running || desc->disable_depth)) 395 goto running; 396 397 /* 398 * Acknowledge and clear the IRQ, but don't mask it. 399 */ 400 desc->chip->ack(irq); 401 402 /* 403 * Mark the IRQ currently in progress. 404 */ 405 desc->running = 1; 406 407 kstat_cpu(cpu).irqs[irq]++; 408 409 do { 410 struct irqaction *action; 411 412 action = desc->action; 413 if (!action) 414 break; 415 416 if (desc->pending && !desc->disable_depth) { 417 desc->pending = 0; 418 desc->chip->unmask(irq); 419 } 420 421 __do_irq(irq, action, regs); 422 } while (desc->pending && !desc->disable_depth); 423 424 desc->running = 0; 425 426 /* 427 * If we were disabled or freed, shut down the handler. 428 */ 429 if (likely(desc->action && !check_irq_lock(desc, irq, regs))) 430 return; 431 432 running: 433 /* 434 * We got another IRQ while this one was masked or 435 * currently running. Delay it. 436 */ 437 desc->pending = 1; 438 desc->chip->mask(irq); 439 desc->chip->ack(irq); 440 } 441 442 /* 443 * Level-based IRQ handler. Nice and simple. 444 */ 445 void 446 do_level_IRQ(unsigned int irq, struct irqdesc *desc, struct pt_regs *regs) 447 { 448 struct irqaction *action; 449 const unsigned int cpu = smp_processor_id(); 450 451 desc->triggered = 1; 452 453 /* 454 * Acknowledge, clear _AND_ disable the interrupt. 455 */ 456 desc->chip->ack(irq); 457 458 if (likely(!desc->disable_depth)) { 459 kstat_cpu(cpu).irqs[irq]++; 460 461 smp_set_running(desc); 462 463 /* 464 * Return with this interrupt masked if no action 465 */ 466 action = desc->action; 467 if (action) { 468 int ret = __do_irq(irq, desc->action, regs); 469 470 if (ret != IRQ_HANDLED) 471 report_bad_irq(irq, regs, desc, ret); 472 473 if (likely(!desc->disable_depth && 474 !check_irq_lock(desc, irq, regs))) 475 desc->chip->unmask(irq); 476 } 477 478 smp_clear_running(desc); 479 } 480 } 481 482 static void do_pending_irqs(struct pt_regs *regs) 483 { 484 struct list_head head, *l, *n; 485 486 do { 487 struct irqdesc *desc; 488 489 /* 490 * First, take the pending interrupts off the list. 491 * The act of calling the handlers may add some IRQs 492 * back onto the list. 493 */ 494 head = irq_pending; 495 INIT_LIST_HEAD(&irq_pending); 496 head.next->prev = &head; 497 head.prev->next = &head; 498 499 /* 500 * Now run each entry. We must delete it from our 501 * list before calling the handler. 502 */ 503 list_for_each_safe(l, n, &head) { 504 desc = list_entry(l, struct irqdesc, pend); 505 list_del_init(&desc->pend); 506 desc->handle(desc - irq_desc, desc, regs); 507 } 508 509 /* 510 * The list must be empty. 511 */ 512 BUG_ON(!list_empty(&head)); 513 } while (!list_empty(&irq_pending)); 514 } 515 516 /* 517 * do_IRQ handles all hardware IRQ's. Decoded IRQs should not 518 * come via this function. Instead, they should provide their 519 * own 'handler' 520 */ 521 asmlinkage void asm_do_IRQ(unsigned int irq, struct pt_regs *regs) 522 { 523 struct irqdesc *desc = irq_desc + irq; 524 525 /* 526 * Some hardware gives randomly wrong interrupts. Rather 527 * than crashing, do something sensible. 528 */ 529 if (irq >= NR_IRQS) 530 desc = &bad_irq_desc; 531 532 irq_enter(); 533 spin_lock(&irq_controller_lock); 534 desc->handle(irq, desc, regs); 535 536 /* 537 * Now re-run any pending interrupts. 538 */ 539 if (!list_empty(&irq_pending)) 540 do_pending_irqs(regs); 541 542 irq_finish(irq); 543 544 spin_unlock(&irq_controller_lock); 545 irq_exit(); 546 } 547 548 void __set_irq_handler(unsigned int irq, irq_handler_t handle, int is_chained) 549 { 550 struct irqdesc *desc; 551 unsigned long flags; 552 553 if (irq >= NR_IRQS) { 554 printk(KERN_ERR "Trying to install handler for IRQ%d\n", irq); 555 return; 556 } 557 558 if (handle == NULL) 559 handle = do_bad_IRQ; 560 561 desc = irq_desc + irq; 562 563 if (is_chained && desc->chip == &bad_chip) 564 printk(KERN_WARNING "Trying to install chained handler for IRQ%d\n", irq); 565 566 spin_lock_irqsave(&irq_controller_lock, flags); 567 if (handle == do_bad_IRQ) { 568 desc->chip->mask(irq); 569 desc->chip->ack(irq); 570 desc->disable_depth = 1; 571 } 572 desc->handle = handle; 573 if (handle != do_bad_IRQ && is_chained) { 574 desc->valid = 0; 575 desc->probe_ok = 0; 576 desc->disable_depth = 0; 577 desc->chip->unmask(irq); 578 } 579 spin_unlock_irqrestore(&irq_controller_lock, flags); 580 } 581 582 void set_irq_chip(unsigned int irq, struct irqchip *chip) 583 { 584 struct irqdesc *desc; 585 unsigned long flags; 586 587 if (irq >= NR_IRQS) { 588 printk(KERN_ERR "Trying to install chip for IRQ%d\n", irq); 589 return; 590 } 591 592 if (chip == NULL) 593 chip = &bad_chip; 594 595 desc = irq_desc + irq; 596 spin_lock_irqsave(&irq_controller_lock, flags); 597 desc->chip = chip; 598 spin_unlock_irqrestore(&irq_controller_lock, flags); 599 } 600 601 int set_irq_type(unsigned int irq, unsigned int type) 602 { 603 struct irqdesc *desc; 604 unsigned long flags; 605 int ret = -ENXIO; 606 607 if (irq >= NR_IRQS) { 608 printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq); 609 return -ENODEV; 610 } 611 612 desc = irq_desc + irq; 613 if (desc->chip->type) { 614 spin_lock_irqsave(&irq_controller_lock, flags); 615 ret = desc->chip->type(irq, type); 616 spin_unlock_irqrestore(&irq_controller_lock, flags); 617 } 618 619 return ret; 620 } 621 EXPORT_SYMBOL(set_irq_type); 622 623 void set_irq_flags(unsigned int irq, unsigned int iflags) 624 { 625 struct irqdesc *desc; 626 unsigned long flags; 627 628 if (irq >= NR_IRQS) { 629 printk(KERN_ERR "Trying to set irq flags for IRQ%d\n", irq); 630 return; 631 } 632 633 desc = irq_desc + irq; 634 spin_lock_irqsave(&irq_controller_lock, flags); 635 desc->valid = (iflags & IRQF_VALID) != 0; 636 desc->probe_ok = (iflags & IRQF_PROBE) != 0; 637 desc->noautoenable = (iflags & IRQF_NOAUTOEN) != 0; 638 spin_unlock_irqrestore(&irq_controller_lock, flags); 639 } 640 641 int setup_irq(unsigned int irq, struct irqaction *new) 642 { 643 int shared = 0; 644 struct irqaction *old, **p; 645 unsigned long flags; 646 struct irqdesc *desc; 647 648 /* 649 * Some drivers like serial.c use request_irq() heavily, 650 * so we have to be careful not to interfere with a 651 * running system. 652 */ 653 if (new->flags & SA_SAMPLE_RANDOM) { 654 /* 655 * This function might sleep, we want to call it first, 656 * outside of the atomic block. 657 * Yes, this might clear the entropy pool if the wrong 658 * driver is attempted to be loaded, without actually 659 * installing a new handler, but is this really a problem, 660 * only the sysadmin is able to do this. 661 */ 662 rand_initialize_irq(irq); 663 } 664 665 /* 666 * The following block of code has to be executed atomically 667 */ 668 desc = irq_desc + irq; 669 spin_lock_irqsave(&irq_controller_lock, flags); 670 p = &desc->action; 671 if ((old = *p) != NULL) { 672 /* Can't share interrupts unless both agree to */ 673 if (!(old->flags & new->flags & SA_SHIRQ)) { 674 spin_unlock_irqrestore(&irq_controller_lock, flags); 675 return -EBUSY; 676 } 677 678 /* add new interrupt at end of irq queue */ 679 do { 680 p = &old->next; 681 old = *p; 682 } while (old); 683 shared = 1; 684 } 685 686 *p = new; 687 688 if (!shared) { 689 desc->probing = 0; 690 desc->running = 0; 691 desc->pending = 0; 692 desc->disable_depth = 1; 693 if (!desc->noautoenable) { 694 desc->disable_depth = 0; 695 desc->chip->unmask(irq); 696 } 697 } 698 699 spin_unlock_irqrestore(&irq_controller_lock, flags); 700 return 0; 701 } 702 703 /** 704 * request_irq - allocate an interrupt line 705 * @irq: Interrupt line to allocate 706 * @handler: Function to be called when the IRQ occurs 707 * @irqflags: Interrupt type flags 708 * @devname: An ascii name for the claiming device 709 * @dev_id: A cookie passed back to the handler function 710 * 711 * This call allocates interrupt resources and enables the 712 * interrupt line and IRQ handling. From the point this 713 * call is made your handler function may be invoked. Since 714 * your handler function must clear any interrupt the board 715 * raises, you must take care both to initialise your hardware 716 * and to set up the interrupt handler in the right order. 717 * 718 * Dev_id must be globally unique. Normally the address of the 719 * device data structure is used as the cookie. Since the handler 720 * receives this value it makes sense to use it. 721 * 722 * If your interrupt is shared you must pass a non NULL dev_id 723 * as this is required when freeing the interrupt. 724 * 725 * Flags: 726 * 727 * SA_SHIRQ Interrupt is shared 728 * 729 * SA_INTERRUPT Disable local interrupts while processing 730 * 731 * SA_SAMPLE_RANDOM The interrupt can be used for entropy 732 * 733 */ 734 int request_irq(unsigned int irq, irqreturn_t (*handler)(int, void *, struct pt_regs *), 735 unsigned long irq_flags, const char * devname, void *dev_id) 736 { 737 unsigned long retval; 738 struct irqaction *action; 739 740 if (irq >= NR_IRQS || !irq_desc[irq].valid || !handler || 741 (irq_flags & SA_SHIRQ && !dev_id)) 742 return -EINVAL; 743 744 action = (struct irqaction *)kmalloc(sizeof(struct irqaction), GFP_KERNEL); 745 if (!action) 746 return -ENOMEM; 747 748 action->handler = handler; 749 action->flags = irq_flags; 750 cpus_clear(action->mask); 751 action->name = devname; 752 action->next = NULL; 753 action->dev_id = dev_id; 754 755 retval = setup_irq(irq, action); 756 757 if (retval) 758 kfree(action); 759 return retval; 760 } 761 762 EXPORT_SYMBOL(request_irq); 763 764 /** 765 * free_irq - free an interrupt 766 * @irq: Interrupt line to free 767 * @dev_id: Device identity to free 768 * 769 * Remove an interrupt handler. The handler is removed and if the 770 * interrupt line is no longer in use by any driver it is disabled. 771 * On a shared IRQ the caller must ensure the interrupt is disabled 772 * on the card it drives before calling this function. 773 * 774 * This function must not be called from interrupt context. 775 */ 776 void free_irq(unsigned int irq, void *dev_id) 777 { 778 struct irqaction * action, **p; 779 unsigned long flags; 780 781 if (irq >= NR_IRQS || !irq_desc[irq].valid) { 782 printk(KERN_ERR "Trying to free IRQ%d\n",irq); 783 dump_stack(); 784 return; 785 } 786 787 spin_lock_irqsave(&irq_controller_lock, flags); 788 for (p = &irq_desc[irq].action; (action = *p) != NULL; p = &action->next) { 789 if (action->dev_id != dev_id) 790 continue; 791 792 /* Found it - now free it */ 793 *p = action->next; 794 break; 795 } 796 spin_unlock_irqrestore(&irq_controller_lock, flags); 797 798 if (!action) { 799 printk(KERN_ERR "Trying to free free IRQ%d\n",irq); 800 dump_stack(); 801 } else { 802 synchronize_irq(irq); 803 kfree(action); 804 } 805 } 806 807 EXPORT_SYMBOL(free_irq); 808 809 static DECLARE_MUTEX(probe_sem); 810 811 /* Start the interrupt probing. Unlike other architectures, 812 * we don't return a mask of interrupts from probe_irq_on, 813 * but return the number of interrupts enabled for the probe. 814 * The interrupts which have been enabled for probing is 815 * instead recorded in the irq_desc structure. 816 */ 817 unsigned long probe_irq_on(void) 818 { 819 unsigned int i, irqs = 0; 820 unsigned long delay; 821 822 down(&probe_sem); 823 824 /* 825 * first snaffle up any unassigned but 826 * probe-able interrupts 827 */ 828 spin_lock_irq(&irq_controller_lock); 829 for (i = 0; i < NR_IRQS; i++) { 830 if (!irq_desc[i].probe_ok || irq_desc[i].action) 831 continue; 832 833 irq_desc[i].probing = 1; 834 irq_desc[i].triggered = 0; 835 if (irq_desc[i].chip->type) 836 irq_desc[i].chip->type(i, IRQT_PROBE); 837 irq_desc[i].chip->unmask(i); 838 irqs += 1; 839 } 840 spin_unlock_irq(&irq_controller_lock); 841 842 /* 843 * wait for spurious interrupts to mask themselves out again 844 */ 845 for (delay = jiffies + HZ/10; time_before(jiffies, delay); ) 846 /* min 100ms delay */; 847 848 /* 849 * now filter out any obviously spurious interrupts 850 */ 851 spin_lock_irq(&irq_controller_lock); 852 for (i = 0; i < NR_IRQS; i++) { 853 if (irq_desc[i].probing && irq_desc[i].triggered) { 854 irq_desc[i].probing = 0; 855 irqs -= 1; 856 } 857 } 858 spin_unlock_irq(&irq_controller_lock); 859 860 return irqs; 861 } 862 863 EXPORT_SYMBOL(probe_irq_on); 864 865 unsigned int probe_irq_mask(unsigned long irqs) 866 { 867 unsigned int mask = 0, i; 868 869 spin_lock_irq(&irq_controller_lock); 870 for (i = 0; i < 16 && i < NR_IRQS; i++) 871 if (irq_desc[i].probing && irq_desc[i].triggered) 872 mask |= 1 << i; 873 spin_unlock_irq(&irq_controller_lock); 874 875 up(&probe_sem); 876 877 return mask; 878 } 879 EXPORT_SYMBOL(probe_irq_mask); 880 881 /* 882 * Possible return values: 883 * >= 0 - interrupt number 884 * -1 - no interrupt/many interrupts 885 */ 886 int probe_irq_off(unsigned long irqs) 887 { 888 unsigned int i; 889 int irq_found = NO_IRQ; 890 891 /* 892 * look at the interrupts, and find exactly one 893 * that we were probing has been triggered 894 */ 895 spin_lock_irq(&irq_controller_lock); 896 for (i = 0; i < NR_IRQS; i++) { 897 if (irq_desc[i].probing && 898 irq_desc[i].triggered) { 899 if (irq_found != NO_IRQ) { 900 irq_found = NO_IRQ; 901 goto out; 902 } 903 irq_found = i; 904 } 905 } 906 907 if (irq_found == -1) 908 irq_found = NO_IRQ; 909 out: 910 spin_unlock_irq(&irq_controller_lock); 911 912 up(&probe_sem); 913 914 return irq_found; 915 } 916 917 EXPORT_SYMBOL(probe_irq_off); 918 919 #ifdef CONFIG_SMP 920 static void route_irq(struct irqdesc *desc, unsigned int irq, unsigned int cpu) 921 { 922 pr_debug("IRQ%u: moving from cpu%u to cpu%u\n", irq, desc->cpu, cpu); 923 924 spin_lock_irq(&irq_controller_lock); 925 desc->cpu = cpu; 926 desc->chip->set_cpu(desc, irq, cpu); 927 spin_unlock_irq(&irq_controller_lock); 928 } 929 930 #ifdef CONFIG_PROC_FS 931 static int 932 irq_affinity_read_proc(char *page, char **start, off_t off, int count, 933 int *eof, void *data) 934 { 935 struct irqdesc *desc = irq_desc + ((int)data); 936 int len = cpumask_scnprintf(page, count, desc->affinity); 937 938 if (count - len < 2) 939 return -EINVAL; 940 page[len++] = '\n'; 941 page[len] = '\0'; 942 943 return len; 944 } 945 946 static int 947 irq_affinity_write_proc(struct file *file, const char __user *buffer, 948 unsigned long count, void *data) 949 { 950 unsigned int irq = (unsigned int)data; 951 struct irqdesc *desc = irq_desc + irq; 952 cpumask_t affinity, tmp; 953 int ret = -EIO; 954 955 if (!desc->chip->set_cpu) 956 goto out; 957 958 ret = cpumask_parse(buffer, count, affinity); 959 if (ret) 960 goto out; 961 962 cpus_and(tmp, affinity, cpu_online_map); 963 if (cpus_empty(tmp)) { 964 ret = -EINVAL; 965 goto out; 966 } 967 968 desc->affinity = affinity; 969 route_irq(desc, irq, first_cpu(tmp)); 970 ret = count; 971 972 out: 973 return ret; 974 } 975 #endif 976 #endif 977 978 void __init init_irq_proc(void) 979 { 980 #if defined(CONFIG_SMP) && defined(CONFIG_PROC_FS) 981 struct proc_dir_entry *dir; 982 int irq; 983 984 dir = proc_mkdir("irq", 0); 985 if (!dir) 986 return; 987 988 for (irq = 0; irq < NR_IRQS; irq++) { 989 struct proc_dir_entry *entry; 990 struct irqdesc *desc; 991 char name[16]; 992 993 desc = irq_desc + irq; 994 memset(name, 0, sizeof(name)); 995 snprintf(name, sizeof(name) - 1, "%u", irq); 996 997 desc->procdir = proc_mkdir(name, dir); 998 if (!desc->procdir) 999 continue; 1000 1001 entry = create_proc_entry("smp_affinity", 0600, desc->procdir); 1002 if (entry) { 1003 entry->nlink = 1; 1004 entry->data = (void *)irq; 1005 entry->read_proc = irq_affinity_read_proc; 1006 entry->write_proc = irq_affinity_write_proc; 1007 } 1008 } 1009 #endif 1010 } 1011 1012 void __init init_IRQ(void) 1013 { 1014 struct irqdesc *desc; 1015 extern void init_dma(void); 1016 int irq; 1017 1018 #ifdef CONFIG_SMP 1019 bad_irq_desc.affinity = CPU_MASK_ALL; 1020 bad_irq_desc.cpu = smp_processor_id(); 1021 #endif 1022 1023 for (irq = 0, desc = irq_desc; irq < NR_IRQS; irq++, desc++) { 1024 *desc = bad_irq_desc; 1025 INIT_LIST_HEAD(&desc->pend); 1026 } 1027 1028 init_arch_irq(); 1029 init_dma(); 1030 } 1031 1032 static int __init noirqdebug_setup(char *str) 1033 { 1034 noirqdebug = 1; 1035 return 1; 1036 } 1037 1038 __setup("noirqdebug", noirqdebug_setup); 1039