arch/um/kernel/irq.c

   1 /*
   2  * Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  * Derived (i.e. mostly copied) from arch/i386/kernel/irq.c:
   5  *      Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
   6  */
   7
   8 #include "linux/config.h"
   9 #include "linux/kernel.h"
  10 #include "linux/module.h"
  11 #include "linux/smp.h"
  12 #include "linux/irq.h"
  13 #include "linux/kernel_stat.h"
  14 #include "linux/interrupt.h"
  15 #include "linux/random.h"
  16 #include "linux/slab.h"
  17 #include "linux/file.h"
  18 #include "linux/proc_fs.h"
  19 #include "linux/init.h"
  20 #include "linux/seq_file.h"
  21 #include "asm/irq.h"
  22 #include "asm/hw_irq.h"
  23 #include "asm/hardirq.h"
  24 #include "asm/atomic.h"
  25 #include "asm/signal.h"
  26 #include "asm/system.h"
  27 #include "asm/errno.h"
  28 #include "asm/uaccess.h"
  29 #include "user_util.h"
  30 #include "kern_util.h"
  31 #include "irq_user.h"
  32
  33 static void register_irq_proc (unsigned int irq);
  34
  35 irq_desc_t irq_desc[NR_IRQS] __cacheline_aligned = {
  36         [0 ... NR_IRQS-1] = {
  37                 .handler = &no_irq_type,
  38                 .lock = SPIN_LOCK_UNLOCKED
  39         }
  40 };
  41
  42 /*
  43  * Generic no controller code
  44  */
  45
  46 static void enable_none(unsigned int irq) { }
  47 static unsigned int startup_none(unsigned int irq) { return 0; }
  48 static void disable_none(unsigned int irq) { }
  49 static 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 #ifdef CONFIG_X86
  57         printk(KERN_ERR "unexpected IRQ trap at vector %02x\n", irq);
  58 #ifdef CONFIG_X86_LOCAL_APIC
  59         /*
  60          * Currently unexpected vectors happen only on SMP and APIC.
  61          * We _must_ ack these because every local APIC has only N
  62          * irq slots per priority level, and a 'hanging, unacked' IRQ
  63          * holds up an irq slot - in excessive cases (when multiple
  64          * unexpected vectors occur) that might lock up the APIC
  65          * completely.
  66          */
  67         ack_APIC_irq();
  68 #endif
  69 #endif
  70 }
  71
  72 /* startup is the same as "enable", shutdown is same as "disable" */
  73 #define shutdown_none   disable_none
  74 #define end_none        enable_none
  75
  76 struct hw_interrupt_type no_irq_type = {
  77         "none",
  78         startup_none,
  79         shutdown_none,
  80         enable_none,
  81         disable_none,
  82         ack_none,
  83         end_none
  84 };
  85
  86 /* Not changed */
  87 volatile unsigned long irq_err_count;
  88
  89 /*
  90  * Generic, controller-independent functions:
  91  */
  92
  93 int get_irq_list(char *buf)
  94 {
  95         int i, j;
  96         unsigned long flags;
  97         struct irqaction * action;
  98         char *p = buf;
  99
 100         p += sprintf(p, "           ");
 101         for (j=0; j<num_online_cpus(); j++)
 102                 p += sprintf(p, "CPU%d       ",j);
 103         *p++ = '\n';
 104
 105         for (i = 0 ; i < NR_IRQS ; i++) {
 106                 spin_lock_irqsave(&irq_desc[i].lock, flags);
 107                 action = irq_desc[i].action;
 108                 if (!action)
 109                         goto end;
 110                 p += sprintf(p, "%3d: ",i);
 111 #ifndef CONFIG_SMP
 112                 p += sprintf(p, "%10u ", kstat_irqs(i));
 113 #else
 114                 for (j = 0; j < num_online_cpus(); j++)
 115                         p += sprintf(p, "%10u ",
 116                                 kstat_cpu(cpu_logical_map(j)).irqs[i]);
 117 #endif
 118                 p += sprintf(p, " %14s", irq_desc[i].handler->typename);
 119                 p += sprintf(p, "  %s", action->name);
 120
 121                 for (action=action->next; action; action = action->next)
 122                         p += sprintf(p, ", %s", action->name);
 123                 *p++ = '\n';
 124         end:
 125                 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
 126         }
 127         p += sprintf(p, "\n");
 128 #ifdef notdef
 129 #ifdef CONFIG_SMP
 130         p += sprintf(p, "LOC: ");
 131         for (j = 0; j < num_online_cpus(); j++)
 132                 p += sprintf(p, "%10u ",
 133                         apic_timer_irqs[cpu_logical_map(j)]);
 134         p += sprintf(p, "\n");
 135 #endif
 136 #endif
 137         p += sprintf(p, "ERR: %10lu\n", irq_err_count);
 138         return p - buf;
 139 }
 140
 141
 142 int show_interrupts(struct seq_file *p, void *v)
 143 {
 144         return(0);
 145 }
 146
 147 /*
 148  * This should really return information about whether
 149  * we should do bottom half handling etc. Right now we
 150  * end up _always_ checking the bottom half, which is a
 151  * waste of time and is not what some drivers would
 152  * prefer.
 153  */
 154 int handle_IRQ_event(unsigned int irq, struct pt_regs * regs,
 155                      struct irqaction * action)
 156 {
 157         int status = 1; /* Force the "do bottom halves" bit */
 158
 159         if (!(action->flags & SA_INTERRUPT))
 160                 local_irq_enable();
 161
 162         do {
 163                 status |= action->flags;
 164                 action->handler(irq, action->dev_id, regs);
 165                 action = action->next;
 166         } while (action);
 167         if (status & SA_SAMPLE_RANDOM)
 168                 add_interrupt_randomness(irq);
 169
 170         local_irq_disable();
 171
 172         return status;
 173 }
 174
 175 /*
 176  * Generic enable/disable code: this just calls
 177  * down into the PIC-specific version for the actual
 178  * hardware disable after having gotten the irq
 179  * controller lock.
 180  */
 181
 182 /**
 183  *      disable_irq_nosync - disable an irq without waiting
 184  *      @irq: Interrupt to disable
 185  *
 186  *      Disable the selected interrupt line. Disables of an interrupt
 187  *      stack. Unlike disable_irq(), this function does not ensure existing
 188  *      instances of the IRQ handler have completed before returning.
 189  *
 190  *      This function may be called from IRQ context.
 191  */
 192
 193 inline void disable_irq_nosync(unsigned int irq)
 194 {
 195         irq_desc_t *desc = irq_desc + irq;
 196         unsigned long flags;
 197
 198         spin_lock_irqsave(&desc->lock, flags);
 199         if (!desc->depth++) {
 200                 desc->status |= IRQ_DISABLED;
 201                 desc->handler->disable(irq);
 202         }
 203         spin_unlock_irqrestore(&desc->lock, flags);
 204 }
 205
 206 #ifdef CONFIG_SMP
 207 inline void synchronize_irq(unsigned int irq)
 208 {
 209         /* is there anything to synchronize with? */
 210         if (!irq_desc[irq].action)
 211                 return;
 212
 213         while (irq_desc[irq].status & IRQ_INPROGRESS)
 214                 cpu_relax();
 215 }
 216 #endif
 217
 218 /**
 219  *      disable_irq - disable an irq and wait for completion
 220  *      @irq: Interrupt to disable
 221  *
 222  *      Disable the selected interrupt line. Disables of an interrupt
 223  *      stack. That is for two disables you need two enables. This
 224  *      function waits for any pending IRQ handlers for this interrupt
 225  *      to complete before returning. If you use this function while
 226  *      holding a resource the IRQ handler may need you will deadlock.
 227  *
 228  *      This function may be called - with care - from IRQ context.
 229  */
 230
 231 void disable_irq(unsigned int irq)
 232 {
 233         disable_irq_nosync(irq);
 234         synchronize_irq(irq);
 235 }
 236
 237 /**
 238  *      enable_irq - enable interrupt handling on an irq
 239  *      @irq: Interrupt to enable
 240  *
 241  *      Re-enables the processing of interrupts on this IRQ line
 242  *      providing no disable_irq calls are now in effect.
 243  *
 244  *      This function may be called from IRQ context.
 245  */
 246
 247 void enable_irq(unsigned int irq)
 248 {
 249         irq_desc_t *desc = irq_desc + irq;
 250         unsigned long flags;
 251
 252         spin_lock_irqsave(&desc->lock, flags);
 253         switch (desc->depth) {
 254         case 1: {
 255                 unsigned int status = desc->status & ~IRQ_DISABLED;
 256                 desc->status = status;
 257                 if ((status & (IRQ_PENDING | IRQ_REPLAY)) == IRQ_PENDING) {
 258                         desc->status = status | IRQ_REPLAY;
 259                         hw_resend_irq(desc->handler,irq);
 260                 }
 261                 desc->handler->enable(irq);
 262                 /* fall-through */
 263         }
 264         default:
 265                 desc->depth--;
 266                 break;
 267         case 0:
 268                 printk(KERN_ERR "enable_irq() unbalanced from %p\n",
 269                        __builtin_return_address(0));
 270         }
 271         spin_unlock_irqrestore(&desc->lock, flags);
 272 }
 273
 274 /*
 275  * do_IRQ handles all normal device IRQ's (the special
 276  * SMP cross-CPU interrupts have their own specific
 277  * handlers).
 278  */
 279 unsigned int do_IRQ(int irq, union uml_pt_regs *regs)
 280 {
 281         /*
 282          * 0 return value means that this irq is already being
 283          * handled by some other CPU. (or is disabled)
 284          */
 285         int cpu = smp_processor_id();
 286         irq_desc_t *desc = irq_desc + irq;
 287         struct irqaction * action;
 288         unsigned int status;
 289
 290         irq_enter();
 291         kstat_cpu(cpu).irqs[irq]++;
 292         spin_lock(&desc->lock);
 293         desc->handler->ack(irq);
 294         /*
 295            REPLAY is when Linux resends an IRQ that was dropped earlier
 296            WAITING is used by probe to mark irqs that are being tested
 297            */
 298         status = desc->status & ~(IRQ_REPLAY | IRQ_WAITING);
 299         status |= IRQ_PENDING; /* we _want_ to handle it */
 300
 301         /*
 302          * If the IRQ is disabled for whatever reason, we cannot
 303          * use the action we have.
 304          */
 305         action = NULL;
 306         if (!(status & (IRQ_DISABLED | IRQ_INPROGRESS))) {
 307                 action = desc->action;
 308                 status &= ~IRQ_PENDING; /* we commit to handling */
 309                 status |= IRQ_INPROGRESS; /* we are handling it */
 310         }
 311         desc->status = status;
 312
 313         /*
 314          * If there is no IRQ handler or it was disabled, exit early.
 315            Since we set PENDING, if another processor is handling
 316            a different instance of this same irq, the other processor
 317            will take care of it.
 318          */
 319         if (!action)
 320                 goto out;
 321
 322         /*
 323          * Edge triggered interrupts need to remember
 324          * pending events.
 325          * This applies to any hw interrupts that allow a second
 326          * instance of the same irq to arrive while we are in do_IRQ
 327          * or in the handler. But the code here only handles the _second_
 328          * instance of the irq, not the third or fourth. So it is mostly
 329          * useful for irq hardware that does not mask cleanly in an
 330          * SMP environment.
 331          */
 332         for (;;) {
 333                 spin_unlock(&desc->lock);
 334                 handle_IRQ_event(irq, (struct pt_regs *) regs, action);
 335                 spin_lock(&desc->lock);
 336
 337                 if (!(desc->status & IRQ_PENDING))
 338                         break;
 339                 desc->status &= ~IRQ_PENDING;
 340         }
 341         desc->status &= ~IRQ_INPROGRESS;
 342 out:
 343         /*
 344          * The ->end() handler has to deal with interrupts which got
 345          * disabled while the handler was running.
 346          */
 347         desc->handler->end(irq);
 348         spin_unlock(&desc->lock);
 349
 350         irq_exit();
 351
 352         return 1;
 353 }
 354
 355 /**
 356  *      request_irq - allocate an interrupt line
 357  *      @irq: Interrupt line to allocate
 358  *      @handler: Function to be called when the IRQ occurs
 359  *      @irqflags: Interrupt type flags
 360  *      @devname: An ascii name for the claiming device
 361  *      @dev_id: A cookie passed back to the handler function
 362  *
 363  *      This call allocates interrupt resources and enables the
 364  *      interrupt line and IRQ handling. From the point this
 365  *      call is made your handler function may be invoked. Since
 366  *      your handler function must clear any interrupt the board
 367  *      raises, you must take care both to initialise your hardware
 368  *      and to set up the interrupt handler in the right order.
 369  *
 370  *      Dev_id must be globally unique. Normally the address of the
 371  *      device data structure is used as the cookie. Since the handler
 372  *      receives this value it makes sense to use it.
 373  *
 374  *      If your interrupt is shared you must pass a non NULL dev_id
 375  *      as this is required when freeing the interrupt.
 376  *
 377  *      Flags:
 378  *
 379  *      SA_SHIRQ                Interrupt is shared
 380  *
 381  *      SA_INTERRUPT            Disable local interrupts while processing
 382  *
 383  *      SA_SAMPLE_RANDOM        The interrupt can be used for entropy
 384  *
 385  */
 386
 387 int request_irq(unsigned int irq,
 388                 void (*handler)(int, void *, struct pt_regs *),
 389                 unsigned long irqflags,
 390                 const char * devname,
 391                 void *dev_id)
 392 {
 393         int retval;
 394         struct irqaction * action;
 395
 396 #if 1
 397         /*
 398          * Sanity-check: shared interrupts should REALLY pass in
 399          * a real dev-ID, otherwise we'll have trouble later trying
 400          * to figure out which interrupt is which (messes up the
 401          * interrupt freeing logic etc).
 402          */
 403         if (irqflags & SA_SHIRQ) {
 404                 if (!dev_id)
 405                         printk(KERN_ERR "Bad boy: %s (at 0x%x) called us "
 406                                "without a dev_id!\n", devname, (&irq)[-1]);
 407         }
 408 #endif
 409
 410         if (irq >= NR_IRQS)
 411                 return -EINVAL;
 412         if (!handler)
 413                 return -EINVAL;
 414
 415         action = (struct irqaction *)
 416                         kmalloc(sizeof(struct irqaction), GFP_KERNEL);
 417         if (!action)
 418                 return -ENOMEM;
 419
 420         action->handler = handler;
 421         action->flags = irqflags;
 422         action->mask = 0;
 423         action->name = devname;
 424         action->next = NULL;
 425         action->dev_id = dev_id;
 426
 427         retval = setup_irq(irq, action);
 428         if (retval)
 429                 kfree(action);
 430         return retval;
 431 }
 432
 433 EXPORT_SYMBOL(request_irq);
 434
 435 int um_request_irq(unsigned int irq, int fd, int type,
 436                    void (*handler)(int, void *, struct pt_regs *),
 437                    unsigned long irqflags, const char * devname,
 438                    void *dev_id)
 439 {
 440         int retval;
 441
 442         retval = request_irq(irq, handler, irqflags, devname, dev_id);
 443         if(retval) return(retval);
 444         return(activate_fd(irq, fd, type, dev_id));
 445 }
 446
 447 /* this was setup_x86_irq but it seems pretty generic */
 448 int setup_irq(unsigned int irq, struct irqaction * new)
 449 {
 450         int shared = 0;
 451         unsigned long flags;
 452         struct irqaction *old, **p;
 453         irq_desc_t *desc = irq_desc + irq;
 454
 455         /*
 456          * Some drivers like serial.c use request_irq() heavily,
 457          * so we have to be careful not to interfere with a
 458          * running system.
 459          */
 460         if (new->flags & SA_SAMPLE_RANDOM) {
 461                 /*
 462                  * This function might sleep, we want to call it first,
 463                  * outside of the atomic block.
 464                  * Yes, this might clear the entropy pool if the wrong
 465                  * driver is attempted to be loaded, without actually
 466                  * installing a new handler, but is this really a problem,
 467                  * only the sysadmin is able to do this.
 468                  */
 469                 rand_initialize_irq(irq);
 470         }
 471
 472         /*
 473          * The following block of code has to be executed atomically
 474          */
 475         spin_lock_irqsave(&desc->lock,flags);
 476         p = &desc->action;
 477         if ((old = *p) != NULL) {
 478                 /* Can't share interrupts unless both agree to */
 479                 if (!(old->flags & new->flags & SA_SHIRQ)) {
 480                         spin_unlock_irqrestore(&desc->lock,flags);
 481                         return -EBUSY;
 482                 }
 483
 484                 /* add new interrupt at end of irq queue */
 485                 do {
 486                         p = &old->next;
 487                         old = *p;
 488                 } while (old);
 489                 shared = 1;
 490         }
 491
 492         *p = new;
 493
 494         if (!shared) {
 495                 desc->depth = 0;
 496                 desc->status &= ~IRQ_DISABLED;
 497                 desc->handler->startup(irq);
 498         }
 499         spin_unlock_irqrestore(&desc->lock,flags);
 500
 501         register_irq_proc(irq);
 502         return 0;
 503 }
 504
 505 /**
 506  *      free_irq - free an interrupt
 507  *      @irq: Interrupt line to free
 508  *      @dev_id: Device identity to free
 509  *
 510  *      Remove an interrupt handler. The handler is removed and if the
 511  *      interrupt line is no longer in use by any driver it is disabled.
 512  *      On a shared IRQ the caller must ensure the interrupt is disabled
 513  *      on the card it drives before calling this function. The function
 514  *      does not return until any executing interrupts for this IRQ
 515  *      have completed.
 516  *
 517  *      This function may be called from interrupt context.
 518  *
 519  *      Bugs: Attempting to free an irq in a handler for the same irq hangs
 520  *            the machine.
 521  */
 522
 523 void free_irq(unsigned int irq, void *dev_id)
 524 {
 525         irq_desc_t *desc;
 526         struct irqaction **p;
 527         unsigned long flags;
 528
 529         if (irq >= NR_IRQS)
 530                 return;
 531
 532         desc = irq_desc + irq;
 533         spin_lock_irqsave(&desc->lock,flags);
 534         p = &desc->action;
 535         for (;;) {
 536                 struct irqaction * action = *p;
 537                 if (action) {
 538                         struct irqaction **pp = p;
 539                         p = &action->next;
 540                         if (action->dev_id != dev_id)
 541                                 continue;
 542
 543                         /* Found it - now remove it from the list of entries */
 544                         *pp = action->next;
 545                         if (!desc->action) {
 546                                 desc->status |= IRQ_DISABLED;
 547                                 desc->handler->shutdown(irq);
 548                         }
 549                         free_irq_by_irq_and_dev(irq, dev_id);
 550                         spin_unlock_irqrestore(&desc->lock,flags);
 551
 552                         /* Wait to make sure it's not being used on another CPU */
 553                         synchronize_irq(irq);
 554                         kfree(action);
 555                         return;
 556                 }
 557                 printk(KERN_ERR "Trying to free free IRQ%d\n",irq);
 558                 spin_unlock_irqrestore(&desc->lock,flags);
 559                 return;
 560         }
 561 }
 562
 563 EXPORT_SYMBOL(free_irq);
 564
 565 /* These are initialized by sysctl_init, which is called from init/main.c */
 566 static struct proc_dir_entry * root_irq_dir;
 567 static struct proc_dir_entry * irq_dir [NR_IRQS];
 568 static struct proc_dir_entry * smp_affinity_entry [NR_IRQS];
 569
 570 /* These are read and written as longs, so a read won't see a partial write
 571  * even during a race.
 572  */
 573 static cpumask_t irq_affinity [NR_IRQS] = { [0 ... NR_IRQS-1] = CPU_MASK_ALL };
 574
 575 static int irq_affinity_read_proc (char *page, char **start, off_t off,
 576                         int count, int *eof, void *data)
 577 {
 578         int len = cpumask_scnprintf(page, count, irq_affinity[(long)data]);
 579         if (count - len < 2)
 580                 return -EINVAL;
 581         len += sprintf(page + len, "\n");
 582         return len;
 583 }
 584
 585 static int irq_affinity_write_proc (struct file *file, const char *buffer,
 586                                         unsigned long count, void *data)
 587 {
 588         int irq = (long) data, full_count = count, err;
 589         cpumask_t new_value, tmp;
 590
 591         if (!irq_desc[irq].handler->set_affinity)
 592                 return -EIO;
 593
 594         err = cpumask_parse(buffer, count, new_value);
 595
 596 #ifdef CONFIG_SMP
 597         /*
 598          * Do not allow disabling IRQs completely - it's a too easy
 599          * way to make the system unusable accidentally :-) At least
 600          * one online CPU still has to be targeted.
 601          */
 602         cpus_and(tmp, new_value, cpu_online_map);
 603         if (cpus_empty(tmp))
 604                 return -EINVAL;
 605 #endif
 606
 607         irq_affinity[irq] = new_value;
 608         irq_desc[irq].handler->set_affinity(irq, new_value);
 609
 610         return full_count;
 611 }
 612
 613 static int prof_cpu_mask_read_proc (char *page, char **start, off_t off,
 614                         int count, int *eof, void *data)
 615 {
 616         int len = cpumask_scnprintf(page, count, *(cpumask_t *)data);
 617         if (count - len < 2)
 618                 return -EINVAL;
 619         len += sprintf(page + len, "\n");
 620         return len;
 621 }
 622
 623 static int prof_cpu_mask_write_proc (struct file *file, const char *buffer,
 624                                         unsigned long count, void *data)
 625 {
 626         cpumask_t *mask = (cpumask_t *)data, new_value;
 627         unsigned long full_count = count, err;
 628
 629         err = cpumask_parse(buffer, count, new_value);
 630         if (err)
 631                 return err;
 632
 633         *mask = new_value;
 634         return full_count;
 635 }
 636
 637 #define MAX_NAMELEN 10
 638
 639 static void register_irq_proc (unsigned int irq)
 640 {
 641         struct proc_dir_entry *entry;
 642         char name [MAX_NAMELEN];
 643
 644         if (!root_irq_dir || (irq_desc[irq].handler == &no_irq_type) ||
 645             irq_dir[irq])
 646                 return;
 647
 648         memset(name, 0, MAX_NAMELEN);
 649         sprintf(name, "%d", irq);
 650
 651         /* create /proc/irq/1234 */
 652         irq_dir[irq] = proc_mkdir(name, root_irq_dir);
 653
 654         /* create /proc/irq/1234/smp_affinity */
 655         entry = create_proc_entry("smp_affinity", 0600, irq_dir[irq]);
 656
 657         entry->nlink = 1;
 658         entry->data = (void *)(long)irq;
 659         entry->read_proc = irq_affinity_read_proc;
 660         entry->write_proc = irq_affinity_write_proc;
 661
 662         smp_affinity_entry[irq] = entry;
 663 }
 664
 665 /* Read and written as a long */
 666 cpumask_t prof_cpu_mask = CPU_MASK_ALL;
 667
 668 void __init init_irq_proc (void)
 669 {
 670         struct proc_dir_entry *entry;
 671         int i;
 672
 673         /* create /proc/irq */
 674         root_irq_dir = proc_mkdir("irq", 0);
 675
 676         /* create /proc/irq/prof_cpu_mask */
 677         entry = create_proc_entry("prof_cpu_mask", 0600, root_irq_dir);
 678
 679         entry->nlink = 1;
 680         entry->data = (void *)&prof_cpu_mask;
 681         entry->read_proc = prof_cpu_mask_read_proc;
 682         entry->write_proc = prof_cpu_mask_write_proc;
 683
 684         /*
 685          * Create entries for all existing IRQs.
 686          */
 687         for (i = 0; i < NR_IRQS; i++)
 688                 register_irq_proc(i);
 689 }
 690
 691 static spinlock_t irq_spinlock = SPIN_LOCK_UNLOCKED;
 692
 693 unsigned long irq_lock(void)
 694 {
 695         unsigned long flags;
 696
 697         spin_lock_irqsave(&irq_spinlock, flags);
 698         return(flags);
 699 }
 700
 701 void irq_unlock(unsigned long flags)
 702 {
 703         spin_unlock_irqrestore(&irq_spinlock, flags);
 704 }
 705
 706 unsigned long probe_irq_on(void)
 707 {
 708         return(0);
 709 }
 710
 711 EXPORT_SYMBOL(probe_irq_on);
 712
 713 int probe_irq_off(unsigned long val)
 714 {
 715         return(0);
 716 }
 717
 718 EXPORT_SYMBOL(probe_irq_off);
 719
 720 static unsigned int startup_SIGIO_irq(unsigned int irq)
 721 {
 722         return(0);
 723 }
 724
 725 static void shutdown_SIGIO_irq(unsigned int irq)
 726 {
 727 }
 728
 729 static void enable_SIGIO_irq(unsigned int irq)
 730 {
 731 }
 732
 733 static void disable_SIGIO_irq(unsigned int irq)
 734 {
 735 }
 736
 737 static void mask_and_ack_SIGIO(unsigned int irq)
 738 {
 739 }
 740
 741 static void end_SIGIO_irq(unsigned int irq)
 742 {
 743 }
 744
 745 static unsigned int startup_SIGVTALRM_irq(unsigned int irq)
 746 {
 747         return(0);
 748 }
 749
 750 static void shutdown_SIGVTALRM_irq(unsigned int irq)
 751 {
 752 }
 753
 754 static void enable_SIGVTALRM_irq(unsigned int irq)
 755 {
 756 }
 757
 758 static void disable_SIGVTALRM_irq(unsigned int irq)
 759 {
 760 }
 761
 762 static void mask_and_ack_SIGVTALRM(unsigned int irq)
 763 {
 764 }
 765
 766 static void end_SIGVTALRM_irq(unsigned int irq)
 767 {
 768 }
 769
 770 static struct hw_interrupt_type SIGIO_irq_type = {
 771         "SIGIO",
 772         startup_SIGIO_irq,
 773         shutdown_SIGIO_irq,
 774         enable_SIGIO_irq,
 775         disable_SIGIO_irq,
 776         mask_and_ack_SIGIO,
 777         end_SIGIO_irq,
 778         NULL
 779 };
 780
 781 static struct hw_interrupt_type SIGVTALRM_irq_type = {
 782         "SIGVTALRM",
 783         startup_SIGVTALRM_irq,
 784         shutdown_SIGVTALRM_irq,
 785         enable_SIGVTALRM_irq,
 786         disable_SIGVTALRM_irq,
 787         mask_and_ack_SIGVTALRM,
 788         end_SIGVTALRM_irq,
 789         NULL
 790 };
 791
 792 void __init init_IRQ(void)
 793 {
 794         int i;
 795
 796         irq_desc[TIMER_IRQ].status = IRQ_DISABLED;
 797         irq_desc[TIMER_IRQ].action = 0;
 798         irq_desc[TIMER_IRQ].depth = 1;
 799         irq_desc[TIMER_IRQ].handler = &SIGVTALRM_irq_type;
 800         enable_irq(TIMER_IRQ);
 801         for(i=1;i<NR_IRQS;i++){
 802                 irq_desc[i].status = IRQ_DISABLED;
 803                 irq_desc[i].action = 0;
 804                 irq_desc[i].depth = 1;
 805                 irq_desc[i].handler = &SIGIO_irq_type;
 806                 enable_irq(i);
 807         }
 808         init_irq_signals(0);
 809 }
 810
 811 /*
 812  * Overrides for Emacs so that we follow Linus's tabbing style.
 813  * Emacs will notice this stuff at the end of the file and automatically
 814  * adjust the settings for this buffer only.  This must remain at the end
 815  * of the file.
 816  * ---------------------------------------------------------------------------
 817  * Local variables:
 818  * c-file-style: "linux"
 819  * End:
 820  */