1/* 2 * This file is subject to the terms and conditions of the GNU General Public 3 * License. See the file "COPYING" in the main directory of this archive 4 * for more details. 5 * 6 * Code to handle x86 style IRQs plus some generic interrupt stuff. 7 * 8 * Copyright (C) 1992 Linus Torvalds 9 * Copyright (C) 1994 - 2000 Ralf Baechle 10 */ 11#include <linux/config.h> 12#include <linux/kernel.h> 13#include <linux/delay.h> 14#include <linux/init.h> 15#include <linux/interrupt.h> 16#include <linux/kernel_stat.h> 17#include <linux/module.h> 18#include <linux/proc_fs.h> 19#include <linux/slab.h> 20#include <linux/mm.h> 21#include <linux/random.h> 22#include <linux/sched.h> 23 24#include <asm/atomic.h> 25#include <asm/system.h> 26#include <asm/uaccess.h> 27 28/* 29 * Controller mappings for all interrupt sources: 30 */ 31irq_desc_t irq_desc[NR_IRQS] __cacheline_aligned = 32 { [0 ... NR_IRQS-1] = { 0, &no_irq_type, NULL, 0, SPIN_LOCK_UNLOCKED}}; 33 34static void register_irq_proc (unsigned int irq); 35 36/* 37 * Special irq handlers. 38 */ 39 40void no_action(int cpl, void *dev_id, struct pt_regs *regs) { } 41 42/* 43 * Generic no controller code 44 */ 45 46static void enable_none(unsigned int irq) { } 47static unsigned int startup_none(unsigned int irq) { return 0; } 48static void disable_none(unsigned int irq) { } 49static void ack_none(unsigned int irq) 50{ 51 /* 52 * 'what should we do if we get a hw irq event on an illegal vector'. 53 * each architecture has to answer this themselves, it doesn't deserve 54 * a generic callback i think. 55 */ 56 printk("unexpected interrupt %d\n", irq); 57} 58 59/* startup is the same as "enable", shutdown is same as "disable" */ 60#define shutdown_none disable_none 61#define end_none enable_none 62 63struct hw_interrupt_type no_irq_type = { 64 "none", 65 startup_none, 66 shutdown_none, 67 enable_none, 68 disable_none, 69 ack_none, 70 end_none 71}; 72 73atomic_t irq_err_count; 74 75/* 76 * Generic, controller-independent functions: 77 */ 78 79int get_irq_list(char *buf) 80{ 81 int i, j; 82 struct irqaction * action; 83 char *p = buf; 84 85 p += sprintf(p, " "); 86 for (j=0; j<smp_num_cpus; j++) 87 p += sprintf(p, "CPU%d ",j); 88 *p++ = '\n'; 89 90 for (i = 0 ; i < NR_IRQS ; i++) { 91 action = irq_desc[i].action; 92 if (!action) 93 continue; 94 p += sprintf(p, "%3d: ",i); 95#ifndef CONFIG_SMP 96 p += sprintf(p, "%10u ", kstat_irqs(i)); 97#else 98 for (j = 0; j < smp_num_cpus; j++) 99 p += sprintf(p, "%10u ", 100 kstat.irqs[cpu_logical_map(j)][i]); 101#endif 102 p += sprintf(p, " %14s", irq_desc[i].handler->typename); 103 p += sprintf(p, " %s", action->name); 104 105 for (action=action->next; action; action = action->next) 106 p += sprintf(p, ", %s", action->name); 107 *p++ = '\n'; 108 } 109 p += sprintf(p, "\n"); 110 p += sprintf(p, "ERR: %10u\n", atomic_read(&irq_err_count)); 111 return p - buf; 112} 113 114#ifdef CONFIG_SMP 115int global_irq_holder = NO_PROC_ID; 116spinlock_t global_irq_lock = SPIN_LOCK_UNLOCKED; 117 118/* 119 * Most of this code is take from the mips64 tree (ip27-irq.c). It's virtually 120 * identical to the i386 implentation in arh/i386/irq.c, with translations for 121 * the interrupt enable bit 122 */ 123 124#define MAXCOUNT 100000000 125#define SYNC_OTHER_CORES(x) udelay(x+1) 126 127static inline void wait_on_irq(int cpu) 128{ 129 int count = MAXCOUNT; 130 131 for (;;) { 132 133 /* 134 * Wait until all interrupts are gone. Wait 135 * for bottom half handlers unless we're 136 * already executing in one.. 137 */ 138 if (!irqs_running()) 139 if (local_bh_count(cpu) || !spin_is_locked(&global_bh_lock)) 140 break; 141 142 /* Duh, we have to loop. Release the lock to avoid deadlocks */ 143 spin_unlock(&global_irq_lock); 144 145 for (;;) { 146 if (!--count) { 147 printk("Count spun out. Huh?\n"); 148 count = ~0; 149 } 150 __sti(); 151 SYNC_OTHER_CORES(cpu); 152 __cli(); 153 if (irqs_running()) 154 continue; 155 if (spin_is_locked(&global_irq_lock)) 156 continue; 157 if (!local_bh_count(cpu) && spin_is_locked(&global_bh_lock)) 158 continue; 159 if (spin_trylock(&global_irq_lock)) 160 break; 161 } 162 } 163} 164 165/* 166 * This is called when we want to synchronize with 167 * interrupts. We may for example tell a device to 168 * stop sending interrupts: but to make sure there 169 * are no interrupts that are executing on another 170 * CPU we need to call this function. 171 */ 172void synchronize_irq(void) 173{ 174 if (irqs_running()) { 175 /* Stupid approach */ 176 cli(); 177 sti(); 178 } 179} 180 181static inline void get_irqlock(int cpu) 182{ 183 if (!spin_trylock(&global_irq_lock)) { 184 /* do we already hold the lock? */ 185 if ((unsigned char) cpu == global_irq_holder) 186 return; 187 /* Uhhuh.. Somebody else got it. Wait.. */ 188 spin_lock(&global_irq_lock); 189 } 190 /* 191 * We also to make sure that nobody else is running 192 * in an interrupt context. 193 */ 194 wait_on_irq(cpu); 195 196 /* 197 * Ok, finally.. 198 */ 199 global_irq_holder = cpu; 200} 201 202/* 203 * A global "cli()" while in an interrupt context turns into just a local 204 * cli(). Interrupts should use spinlocks for the (very unlikely) case that 205 * they ever want to protect against each other. 206 * 207 * If we already have local interrupts disabled, this will not turn a local 208 * disable into a global one (problems with spinlocks: this makes 209 * save_flags+cli+sti usable inside a spinlock). 210 */ 211 212void __global_cli(void) 213{ 214 unsigned int flags; 215 216 __save_flags(flags); 217 if (flags & ST0_IE) { 218 int cpu = smp_processor_id(); 219 __cli(); 220 if (!local_irq_count(cpu)) 221 get_irqlock(cpu); 222 } 223} 224 225void __global_sti(void) 226{ 227 int cpu = smp_processor_id(); 228 229 if (!local_irq_count(cpu)) 230 release_irqlock(cpu); 231 __sti(); 232} 233 234/* 235 * SMP flags value to restore to: 236 * 0 - global cli 237 * 1 - global sti 238 * 2 - local cli 239 * 3 - local sti 240 */ 241unsigned long __global_save_flags(void) 242{ 243 int retval; 244 int local_enabled; 245 unsigned long flags; 246 int cpu = smp_processor_id(); 247 248 __save_flags(flags); 249 local_enabled = (flags & ST0_IE); 250 /* default to local */ 251 retval = 2 + local_enabled; 252 253 /* check for global flags if we're not in an interrupt */ 254 if (!local_irq_count(cpu)) { 255 if (local_enabled) 256 retval = 1; 257 if (global_irq_holder == cpu) 258 retval = 0; 259 } 260 261 return retval; 262} 263 264void __global_restore_flags(unsigned long flags) 265{ 266 switch (flags) { 267 case 0: 268 __global_cli(); 269 break; 270 case 1: 271 __global_sti(); 272 break; 273 case 2: 274 __cli(); 275 break; 276 case 3: 277 __sti(); 278 break; 279 default: 280 printk("global_restore_flags: %08lx\n", flags); 281 } 282} 283#endif /* CONFIG_SMP */ 284 285/* 286 * This should really return information about whether 287 * we should do bottom half handling etc. Right now we 288 * end up _always_ checking the bottom half, which is a 289 * waste of time and is not what some drivers would 290 * prefer. 291 */ 292int handle_IRQ_event(unsigned int irq, struct pt_regs * regs, struct irqaction * action) 293{ 294 int status; 295 int cpu = smp_processor_id(); 296 297 irq_enter(cpu, irq); 298 299 status = 1; /* Force the "do bottom halves" bit */ 300 301 if (!(action->flags & SA_INTERRUPT)) 302 __sti(); 303 304 do { 305 status |= action->flags; 306 action->handler(irq, action->dev_id, regs); 307 action = action->next; 308 } while (action); 309 if (status & SA_SAMPLE_RANDOM) 310 add_interrupt_randomness(irq); 311 __cli(); 312 313 irq_exit(cpu, irq); 314 315 return status; 316} 317 318/* 319 * Generic enable/disable code: this just calls 320 * down into the PIC-specific version for the actual 321 * hardware disable after having gotten the irq 322 * controller lock. 323 */ 324 325/** 326 * disable_irq_nosync - disable an irq without waiting 327 * @irq: Interrupt to disable 328 * 329 * Disable the selected interrupt line. Disables of an interrupt 330 * stack. Unlike disable_irq(), this function does not ensure existing 331 * instances of the IRQ handler have completed before returning. 332 * 333 * This function may be called from IRQ context. 334 */ 335 336void inline disable_irq_nosync(unsigned int irq) 337{ 338 irq_desc_t *desc = irq_desc + irq; 339 unsigned long flags; 340 341 spin_lock_irqsave(&desc->lock, flags); 342 if (!desc->depth++) { 343 desc->status |= IRQ_DISABLED; 344 desc->handler->disable(irq); 345 } 346 spin_unlock_irqrestore(&desc->lock, flags); 347} 348 349/** 350 * disable_irq - disable an irq and wait for completion 351 * @irq: Interrupt to disable 352 * 353 * Disable the selected interrupt line. Disables of an interrupt 354 * stack. That is for two disables you need two enables. This 355 * function waits for any pending IRQ handlers for this interrupt 356 * to complete before returning. If you use this function while 357 * holding a resource the IRQ handler may need you will deadlock. 358 * 359 * This function may be called - with care - from IRQ context. 360 */ 361 362void disable_irq(unsigned int irq) 363{ 364 disable_irq_nosync(irq); 365 366 if (!local_irq_count(smp_processor_id())) { 367 do { 368 barrier(); 369 } while (irq_desc[irq].status & IRQ_INPROGRESS); 370 } 371} 372 373/** 374 * enable_irq - enable interrupt handling on an irq 375 * @irq: Interrupt to enable 376 * 377 * Re-enables the processing of interrupts on this IRQ line 378 * providing no disable_irq calls are now in effect. 379 * 380 * This function may be called from IRQ context. 381 */ 382 383void enable_irq(unsigned int irq) 384{ 385 irq_desc_t *desc = irq_desc + irq; 386 unsigned long flags; 387 388 spin_lock_irqsave(&desc->lock, flags); 389 switch (desc->depth) { 390 case 1: { 391 unsigned int status = desc->status & ~IRQ_DISABLED; 392 desc->status = status; 393 if ((status & (IRQ_PENDING | IRQ_REPLAY)) == IRQ_PENDING) { 394 desc->status = status | IRQ_REPLAY; 395 hw_resend_irq(desc->handler,irq); 396 } 397 desc->handler->enable(irq); 398 /* fall-through */ 399 } 400 default: 401 desc->depth--; 402 break; 403 case 0: 404 printk("enable_irq(%u) unbalanced from %p\n", irq, 405 __builtin_return_address(0)); 406 } 407 spin_unlock_irqrestore(&desc->lock, flags); 408} 409 410/* 411 * do_IRQ handles all normal device IRQ's (the special 412 * SMP cross-CPU interrupts have their own specific 413 * handlers). 414 */ 415asmlinkage unsigned int do_IRQ(int irq, struct pt_regs *regs) 416{ 417 /* 418 * We ack quickly, we don't want the irq controller 419 * thinking we're snobs just because some other CPU has 420 * disabled global interrupts (we have already done the 421 * INT_ACK cycles, it's too late to try to pretend to the 422 * controller that we aren't taking the interrupt). 423 * 424 * 0 return value means that this irq is already being 425 * handled by some other CPU. (or is disabled) 426 */ 427 int cpu = smp_processor_id(); 428 irq_desc_t *desc = irq_desc + irq; 429 struct irqaction * action; 430 unsigned int status; 431 432 kstat.irqs[cpu][irq]++; 433 spin_lock(&desc->lock); 434 desc->handler->ack(irq); 435 /* 436 REPLAY is when Linux resends an IRQ that was dropped earlier 437 WAITING is used by probe to mark irqs that are being tested 438 */ 439 status = desc->status & ~(IRQ_REPLAY | IRQ_WAITING); 440 status |= IRQ_PENDING; /* we _want_ to handle it */ 441 442 /* 443 * If the IRQ is disabled for whatever reason, we cannot 444 * use the action we have. 445 */ 446 action = NULL; 447 if (!(status & (IRQ_DISABLED | IRQ_INPROGRESS))) { 448 action = desc->action; 449 status &= ~IRQ_PENDING; /* we commit to handling */ 450 status |= IRQ_INPROGRESS; /* we are handling it */ 451 } 452 desc->status = status; 453 454 /* 455 * If there is no IRQ handler or it was disabled, exit early. 456 Since we set PENDING, if another processor is handling 457 a different instance of this same irq, the other processor 458 will take care of it. 459 */ 460 if (!action) 461 goto out; 462 463 /* 464 * Edge triggered interrupts need to remember 465 * pending events. 466 * This applies to any hw interrupts that allow a second 467 * instance of the same irq to arrive while we are in do_IRQ 468 * or in the handler. But the code here only handles the _second_ 469 * instance of the irq, not the third or fourth. So it is mostly 470 * useful for irq hardware that does not mask cleanly in an 471 * SMP environment. 472 */ 473 for (;;) { 474 spin_unlock(&desc->lock); 475 handle_IRQ_event(irq, regs, action); 476 spin_lock(&desc->lock); 477 478 if (!(desc->status & IRQ_PENDING)) 479 break; 480 desc->status &= ~IRQ_PENDING; 481 } 482 desc->status &= ~IRQ_INPROGRESS; 483out: 484 /* 485 * The ->end() handler has to deal with interrupts which got 486 * disabled while the handler was running. 487 */ 488 desc->handler->end(irq); 489 spin_unlock(&desc->lock); 490 491 if (softirq_pending(cpu)) 492 do_softirq(); 493 return 1; 494} 495 496/** 497 * request_irq - allocate an interrupt line 498 * @irq: Interrupt line to allocate 499 * @handler: Function to be called when the IRQ occurs 500 * @irqflags: Interrupt type flags 501 * @devname: An ascii name for the claiming device 502 * @dev_id: A cookie passed back to the handler function 503 * 504 * This call allocates interrupt resources and enables the 505 * interrupt line and IRQ handling. From the point this 506 * call is made your handler function may be invoked. Since 507 * your handler function must clear any interrupt the board 508 * raises, you must take care both to initialise your hardware 509 * and to set up the interrupt handler in the right order. 510 * 511 * Dev_id must be globally unique. Normally the address of the 512 * device data structure is used as the cookie. Since the handler 513 * receives this value it makes sense to use it. 514 * 515 * If your interrupt is shared you must pass a non NULL dev_id 516 * as this is required when freeing the interrupt. 517 * 518 * Flags: 519 * 520 * SA_SHIRQ Interrupt is shared 521 * 522 * SA_INTERRUPT Disable local interrupts while processing 523 * 524 * SA_SAMPLE_RANDOM The interrupt can be used for entropy 525 * 526 */ 527 528int request_irq(unsigned int irq, 529 void (*handler)(int, void *, struct pt_regs *), 530 unsigned long irqflags, 531 const char * devname, 532 void *dev_id) 533{ 534 int retval; 535 struct irqaction * action; 536 537 /* 538 * Sanity-check: shared interrupts should REALLY pass in 539 * a real dev-ID, otherwise we'll have trouble later trying 540 * to figure out which interrupt is which (messes up the 541 * interrupt freeing logic etc). 542 */ 543 if (irqflags & SA_SHIRQ) { 544 if (!dev_id) 545 printk("Bad boy: %s (at 0x%x) called us without a dev_id!\n", devname, (&irq)[-1]); 546 } 547 548 if (irq >= NR_IRQS) 549 return -EINVAL; 550 if (!handler) 551 return -EINVAL; 552 553 action = (struct irqaction *) 554 kmalloc(sizeof(struct irqaction), GFP_KERNEL); 555 if (!action) 556 return -ENOMEM; 557 558 action->handler = handler; 559 action->flags = irqflags; 560 action->mask = 0; 561 action->name = devname; 562 action->next = NULL; 563 action->dev_id = dev_id; 564 565 retval = setup_irq(irq, action); 566 if (retval) 567 kfree(action); 568 return retval; 569} 570 571/** 572 * free_irq - free an interrupt 573 * @irq: Interrupt line to free 574 * @dev_id: Device identity to free 575 * 576 * Remove an interrupt handler. The handler is removed and if the 577 * interrupt line is no longer in use by any driver it is disabled. 578 * On a shared IRQ the caller must ensure the interrupt is disabled 579 * on the card it drives before calling this function. The function 580 * does not return until any executing interrupts for this IRQ 581 * have completed. 582 * 583 * This function may be called from interrupt context. 584 * 585 * Bugs: Attempting to free an irq in a handler for the same irq hangs 586 * the machine. 587 */ 588 589void free_irq(unsigned int irq, void *dev_id) 590{ 591 irq_desc_t *desc; 592 struct irqaction **p; 593 unsigned long flags; 594 595 if (irq >= NR_IRQS) 596 return; 597 598 desc = irq_desc + irq; 599 spin_lock_irqsave(&desc->lock,flags); 600 p = &desc->action; 601 for (;;) { 602 struct irqaction * action = *p; 603 if (action) { 604 struct irqaction **pp = p; 605 p = &action->next; 606 if (action->dev_id != dev_id) 607 continue; 608 609 /* Found it - now remove it from the list of entries */ 610 *pp = action->next; 611 if (!desc->action) { 612 desc->status |= IRQ_DISABLED; 613 desc->handler->shutdown(irq); 614 } 615 spin_unlock_irqrestore(&desc->lock,flags); 616 617#ifdef CONFIG_SMP 618 /* Wait to make sure it's not being used on another CPU */ 619 while (desc->status & IRQ_INPROGRESS) 620 barrier(); 621#endif 622 kfree(action); 623 return; 624 } 625 printk("Trying to free free IRQ%d\n",irq); 626 spin_unlock_irqrestore(&desc->lock,flags); 627 return; 628 } 629} 630 631/* 632 * IRQ autodetection code.. 633 * 634 * This depends on the fact that any interrupt that 635 * comes in on to an unassigned handler will get stuck 636 * with "IRQ_WAITING" cleared and the interrupt 637 * disabled. 638 */ 639 640static DECLARE_MUTEX(probe_sem); 641 642/** 643 * probe_irq_on - begin an interrupt autodetect 644 * 645 * Commence probing for an interrupt. The interrupts are scanned 646 * and a mask of potential interrupt lines is returned. 647 * 648 */ 649 650unsigned long probe_irq_on(void) 651{ 652 unsigned int i; 653 irq_desc_t *desc; 654 unsigned long val; 655 unsigned long delay; 656 657 down(&probe_sem); 658 /* 659 * something may have generated an irq long ago and we want to 660 * flush such a longstanding irq before considering it as spurious. 661 */ 662 for (i = NR_IRQS-1; i > 0; i--) { 663 desc = irq_desc + i; 664 665 spin_lock_irq(&desc->lock); 666 if (!irq_desc[i].action) 667 irq_desc[i].handler->startup(i); 668 spin_unlock_irq(&desc->lock); 669 } 670 671 /* Wait for longstanding interrupts to trigger. */ 672 for (delay = jiffies + HZ/50; time_after(delay, jiffies); ) 673 /* about 20ms delay */ synchronize_irq(); 674 675 /* 676 * enable any unassigned irqs 677 * (we must startup again here because if a longstanding irq 678 * happened in the previous stage, it may have masked itself) 679 */ 680 for (i = NR_IRQS-1; i > 0; i--) { 681 desc = irq_desc + i; 682 683 spin_lock_irq(&desc->lock); 684 if (!desc->action) { 685 desc->status |= IRQ_AUTODETECT | IRQ_WAITING; 686 if (desc->handler->startup(i)) 687 desc->status |= IRQ_PENDING; 688 } 689 spin_unlock_irq(&desc->lock); 690 } 691 692 /* 693 * Wait for spurious interrupts to trigger 694 */ 695 for (delay = jiffies + HZ/10; time_after(delay, jiffies); ) 696 /* about 100ms delay */ synchronize_irq(); 697 698 /* 699 * Now filter out any obviously spurious interrupts 700 */ 701 val = 0; 702 for (i = 0; i < NR_IRQS; i++) { 703 irq_desc_t *desc = irq_desc + i; 704 unsigned int status; 705 706 spin_lock_irq(&desc->lock); 707 status = desc->status; 708 709 if (status & IRQ_AUTODETECT) { 710 /* It triggered already - consider it spurious. */ 711 if (!(status & IRQ_WAITING)) { 712 desc->status = status & ~IRQ_AUTODETECT; 713 desc->handler->shutdown(i); 714 } else 715 if (i < 32) 716 val |= 1 << i; 717 } 718 spin_unlock_irq(&desc->lock); 719 } 720 721 return val; 722} 723 724/* 725 * Return a mask of triggered interrupts (this 726 * can handle only legacy ISA interrupts). 727 */ 728 729/** 730 * probe_irq_mask - scan a bitmap of interrupt lines 731 * @val: mask of interrupts to consider 732 * 733 * Scan the ISA bus interrupt lines and return a bitmap of 734 * active interrupts. The interrupt probe logic state is then 735 * returned to its previous value. 736 * 737 * Note: we need to scan all the irq's even though we will 738 * only return ISA irq numbers - just so that we reset them 739 * all to a known state. 740 */ 741unsigned int probe_irq_mask(unsigned long val) 742{ 743 int i; 744 unsigned int mask; 745 746 mask = 0; 747 for (i = 0; i < NR_IRQS; i++) { 748 irq_desc_t *desc = irq_desc + i; 749 unsigned int status; 750 751 spin_lock_irq(&desc->lock); 752 status = desc->status; 753 754 if (status & IRQ_AUTODETECT) { 755 if (i < 16 && !(status & IRQ_WAITING)) 756 mask |= 1 << i; 757 758 desc->status = status & ~IRQ_AUTODETECT; 759 desc->handler->shutdown(i); 760 } 761 spin_unlock_irq(&desc->lock); 762 } 763 up(&probe_sem); 764 765 return mask & val; 766} 767 768/* 769 * Return the one interrupt that triggered (this can 770 * handle any interrupt source). 771 */ 772 773/** 774 * probe_irq_off - end an interrupt autodetect 775 * @val: mask of potential interrupts (unused) 776 * 777 * Scans the unused interrupt lines and returns the line which 778 * appears to have triggered the interrupt. If no interrupt was 779 * found then zero is returned. If more than one interrupt is 780 * found then minus the first candidate is returned to indicate 781 * their is doubt. 782 * 783 * The interrupt probe logic state is returned to its previous 784 * value. 785 * 786 * BUGS: When used in a module (which arguably shouldnt happen) 787 * nothing prevents two IRQ probe callers from overlapping. The 788 * results of this are non-optimal. 789 */ 790 791int probe_irq_off(unsigned long val) 792{ 793 int i, irq_found, nr_irqs; 794 795 nr_irqs = 0; 796 irq_found = 0; 797 for (i = 0; i < NR_IRQS; i++) { 798 irq_desc_t *desc = irq_desc + i; 799 unsigned int status; 800 801 spin_lock_irq(&desc->lock); 802 status = desc->status; 803 804 if (status & IRQ_AUTODETECT) { 805 if (!(status & IRQ_WAITING)) { 806 if (!nr_irqs) 807 irq_found = i; 808 nr_irqs++; 809 } 810 desc->status = status & ~IRQ_AUTODETECT; 811 desc->handler->shutdown(i); 812 } 813 spin_unlock_irq(&desc->lock); 814 } 815 up(&probe_sem); 816 817 if (nr_irqs > 1) 818 irq_found = -irq_found; 819 return irq_found; 820} 821 822/* this was setup_x86_irq but it seems pretty generic */ 823int setup_irq(unsigned int irq, struct irqaction * new) 824{ 825 int shared = 0; 826 unsigned long flags; 827 struct irqaction *old, **p; 828 irq_desc_t *desc = irq_desc + irq; 829 830 /* 831 * Some drivers like serial.c use request_irq() heavily, 832 * so we have to be careful not to interfere with a 833 * running system. 834 */ 835 if (new->flags & SA_SAMPLE_RANDOM) { 836 /* 837 * This function might sleep, we want to call it first, 838 * outside of the atomic block. 839 * Yes, this might clear the entropy pool if the wrong 840 * driver is attempted to be loaded, without actually 841 * installing a new handler, but is this really a problem, 842 * only the sysadmin is able to do this. 843 */ 844 rand_initialize_irq(irq); 845 } 846 847 /* 848 * The following block of code has to be executed atomically 849 */ 850 spin_lock_irqsave(&desc->lock,flags); 851 p = &desc->action; 852 if ((old = *p) != NULL) { 853 /* Can't share interrupts unless both agree to */ 854 if (!(old->flags & new->flags & SA_SHIRQ)) { 855 spin_unlock_irqrestore(&desc->lock,flags); 856 return -EBUSY; 857 } 858 859 /* add new interrupt at end of irq queue */ 860 do { 861 p = &old->next; 862 old = *p; 863 } while (old); 864 shared = 1; 865 } 866 867 *p = new; 868 869 if (!shared) { 870 desc->depth = 0; 871 desc->status &= ~(IRQ_DISABLED | IRQ_AUTODETECT | IRQ_WAITING); 872 desc->handler->startup(irq); 873 } 874 spin_unlock_irqrestore(&desc->lock,flags); 875 876 register_irq_proc(irq); 877 return 0; 878} 879 880void __init init_generic_irq(void) 881{ 882 int i; 883 884 for (i = 0; i < NR_IRQS; i++) { 885 irq_desc[i].status = IRQ_DISABLED; 886 irq_desc[i].action = NULL; 887 irq_desc[i].depth = 1; 888 irq_desc[i].handler = &no_irq_type; 889 } 890} 891 892EXPORT_SYMBOL(disable_irq_nosync); 893EXPORT_SYMBOL(disable_irq); 894EXPORT_SYMBOL(enable_irq); 895EXPORT_SYMBOL(probe_irq_mask); 896 897static struct proc_dir_entry * root_irq_dir; 898static struct proc_dir_entry * irq_dir [NR_IRQS]; 899 900#define HEX_DIGITS 8 901 902static unsigned int parse_hex_value (const char *buffer, 903 unsigned long count, unsigned long *ret) 904{ 905 unsigned char hexnum [HEX_DIGITS]; 906 unsigned long value; 907 int i; 908 909 if (!count) 910 return -EINVAL; 911 if (count > HEX_DIGITS) 912 count = HEX_DIGITS; 913 if (copy_from_user(hexnum, buffer, count)) 914 return -EFAULT; 915 916 /* 917 * Parse the first 8 characters as a hex string, any non-hex char 918 * is end-of-string. '00e1', 'e1', '00E1', 'E1' are all the same. 919 */ 920 value = 0; 921 922 for (i = 0; i < count; i++) { 923 unsigned int c = hexnum[i]; 924 925 switch (c) { 926 case '0' ... '9': c -= '0'; break; 927 case 'a' ... 'f': c -= 'a'-10; break; 928 case 'A' ... 'F': c -= 'A'-10; break; 929 default: 930 goto out; 931 } 932 value = (value << 4) | c; 933 } 934out: 935 *ret = value; 936 return 0; 937} 938 939#if CONFIG_SMP 940 941static struct proc_dir_entry * smp_affinity_entry [NR_IRQS]; 942 943static unsigned long irq_affinity [NR_IRQS] = { [0 ... NR_IRQS-1] = ~0UL }; 944static int irq_affinity_read_proc (char *page, char **start, off_t off, 945 int count, int *eof, void *data) 946{ 947 if (count < HEX_DIGITS+1) 948 return -EINVAL; 949 return sprintf (page, "%08lx\n", irq_affinity[(long)data]); 950} 951 952static int irq_affinity_write_proc (struct file *file, const char *buffer, 953 unsigned long count, void *data) 954{ 955 int irq = (long) data, full_count = count, err; 956 unsigned long new_value; 957 958 if (!irq_desc[irq].handler->set_affinity) 959 return -EIO; 960 961 err = parse_hex_value(buffer, count, &new_value); 962 963 /* 964 * Do not allow disabling IRQs completely - it's a too easy 965 * way to make the system unusable accidentally :-) At least 966 * one online CPU still has to be targeted. 967 */ 968 if (!(new_value & cpu_online_map)) 969 return -EINVAL; 970 971 irq_affinity[irq] = new_value; 972 irq_desc[irq].handler->set_affinity(irq, new_value); 973 974 return full_count; 975} 976 977#endif 978 979static int prof_cpu_mask_read_proc (char *page, char **start, off_t off, 980 int count, int *eof, void *data) 981{ 982 unsigned long *mask = (unsigned long *) data; 983 if (count < HEX_DIGITS+1) 984 return -EINVAL; 985 return sprintf (page, "%08lx\n", *mask); 986} 987 988static int prof_cpu_mask_write_proc (struct file *file, const char *buffer, 989 unsigned long count, void *data) 990{ 991 unsigned long *mask = (unsigned long *) data, full_count = count, err; 992 unsigned long new_value; 993 994 err = parse_hex_value(buffer, count, &new_value); 995 if (err) 996 return err; 997 998 *mask = new_value; 999 return full_count; 1000} 1001 1002#define MAX_NAMELEN 10 1003 1004static void register_irq_proc (unsigned int irq) 1005{ 1006 char name [MAX_NAMELEN]; 1007 1008 if (!root_irq_dir || (irq_desc[irq].handler == &no_irq_type) || 1009 irq_dir[irq]) 1010 return; 1011 1012 memset(name, 0, MAX_NAMELEN); 1013 sprintf(name, "%d", irq); 1014 1015 /* create /proc/irq/1234 */ 1016 irq_dir[irq] = proc_mkdir(name, root_irq_dir); 1017 1018#if CONFIG_SMP 1019 { 1020 struct proc_dir_entry *entry; 1021 1022 /* create /proc/irq/1234/smp_affinity */ 1023 entry = create_proc_entry("smp_affinity", 0600, irq_dir[irq]); 1024 1025 if (entry) { 1026 entry->nlink = 1; 1027 entry->data = (void *)(long)irq; 1028 entry->read_proc = irq_affinity_read_proc; 1029 entry->write_proc = irq_affinity_write_proc; 1030 } 1031 1032 smp_affinity_entry[irq] = entry; 1033 } 1034#endif 1035} 1036 1037unsigned long prof_cpu_mask = -1; 1038 1039void init_irq_proc (void) 1040{ 1041 struct proc_dir_entry *entry; 1042 int i; 1043 1044 /* create /proc/irq */ 1045 root_irq_dir = proc_mkdir("irq", 0); 1046 1047 /* create /proc/irq/prof_cpu_mask */ 1048 entry = create_proc_entry("prof_cpu_mask", 0600, root_irq_dir); 1049 1050 if (!entry) 1051 return; 1052 1053 entry->nlink = 1; 1054 entry->data = (void *)&prof_cpu_mask; 1055 entry->read_proc = prof_cpu_mask_read_proc; 1056 entry->write_proc = prof_cpu_mask_write_proc; 1057 1058 /* 1059 * Create entries for all existing IRQs. 1060 */ 1061 for (i = 0; i < NR_IRQS; i++) 1062 register_irq_proc(i); 1063} 1064