1 // SPDX-License-Identifier: GPL-2.0 !! 1 /*
2 // Copyright (C) 2018 Hangzhou C-SKY Microsyst !! 2 * This file is subject to the terms and conditions of the GNU General Public
3 !! 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>
4 #include <linux/init.h> 14 #include <linux/init.h>
5 #include <linux/interrupt.h> 15 #include <linux/interrupt.h>
6 #include <linux/irq.h> !! 16 #include <linux/kernel_stat.h>
7 #include <linux/irqchip.h> !! 17 #include <linux/module.h>
8 #include <asm/traps.h> !! 18 #include <linux/proc_fs.h>
9 #include <asm/smp.h> !! 19 #include <linux/slab.h>
>> 20 #include <linux/mm.h>
>> 21 #include <linux/random.h>
>> 22 #include <linux/sched.h>
>> 23 #include <linux/seq_file.h>
>> 24 #include <linux/kallsyms.h>
>> 25
>> 26 #include <asm/atomic.h>
>> 27 #include <asm/system.h>
>> 28 #include <asm/uaccess.h>
>> 29
>> 30 /*
>> 31 * Controller mappings for all interrupt sources:
>> 32 */
>> 33 irq_desc_t irq_desc[NR_IRQS] __cacheline_aligned = {
>> 34 [0 ... NR_IRQS-1] = {
>> 35 .handler = &no_irq_type,
>> 36 .lock = SPIN_LOCK_UNLOCKED
>> 37 }
>> 38 };
>> 39
>> 40 static void register_irq_proc (unsigned int irq);
>> 41
>> 42 /*
>> 43 * Special irq handlers.
>> 44 */
>> 45
>> 46 irqreturn_t no_action(int cpl, void *dev_id, struct pt_regs *regs)
>> 47 { return IRQ_NONE; }
>> 48
>> 49 /*
>> 50 * Generic no controller code
>> 51 */
>> 52
>> 53 static void enable_none(unsigned int irq) { }
>> 54 static unsigned int startup_none(unsigned int irq) { return 0; }
>> 55 static void disable_none(unsigned int irq) { }
>> 56 static void ack_none(unsigned int irq)
>> 57 {
>> 58 /*
>> 59 * 'what should we do if we get a hw irq event on an illegal vector'.
>> 60 * each architecture has to answer this themselves, it doesn't deserve
>> 61 * a generic callback i think.
>> 62 */
>> 63 printk("unexpected interrupt %d\n", irq);
>> 64 }
>> 65
>> 66 /* startup is the same as "enable", shutdown is same as "disable" */
>> 67 #define shutdown_none disable_none
>> 68 #define end_none enable_none
>> 69
>> 70 struct hw_interrupt_type no_irq_type = {
>> 71 "none",
>> 72 startup_none,
>> 73 shutdown_none,
>> 74 enable_none,
>> 75 disable_none,
>> 76 ack_none,
>> 77 end_none
>> 78 };
>> 79
>> 80 atomic_t irq_err_count;
>> 81
>> 82 /*
>> 83 * Generic, controller-independent functions:
>> 84 */
>> 85
>> 86 int show_interrupts(struct seq_file *p, void *v)
>> 87 {
>> 88 int i, j;
>> 89 struct irqaction * action;
>> 90 unsigned long flags;
>> 91
>> 92 seq_printf(p, " ");
>> 93 for (j=0; j<NR_CPUS; j++)
>> 94 if (cpu_online(j))
>> 95 seq_printf(p, "CPU%d ",j);
>> 96 seq_putc(p, '\n');
>> 97
>> 98 for (i = 0 ; i < NR_IRQS ; i++) {
>> 99 spin_lock_irqsave(&irq_desc[i].lock, flags);
>> 100 action = irq_desc[i].action;
>> 101 if (!action)
>> 102 goto skip;
>> 103 seq_printf(p, "%3d: ",i);
>> 104 #ifndef CONFIG_SMP
>> 105 seq_printf(p, "%10u ", kstat_irqs(i));
>> 106 #else
>> 107 for (j = 0; j < NR_CPUS; j++)
>> 108 if (cpu_online(j))
>> 109 seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
>> 110 #endif
>> 111 seq_printf(p, " %14s", irq_desc[i].handler->typename);
>> 112 seq_printf(p, " %s", action->name);
>> 113
>> 114 for (action=action->next; action; action = action->next)
>> 115 seq_printf(p, ", %s", action->name);
>> 116
>> 117 seq_putc(p, '\n');
>> 118 skip:
>> 119 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
>> 120 }
>> 121 seq_putc(p, '\n');
>> 122 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
>> 123
>> 124 return 0;
>> 125 }
>> 126
>> 127 #ifdef CONFIG_SMP
>> 128 inline void synchronize_irq(unsigned int irq)
>> 129 {
>> 130 while (irq_desc[irq].status & IRQ_INPROGRESS)
>> 131 cpu_relax();
>> 132 }
>> 133 #endif
>> 134
>> 135 /*
>> 136 * This should really return information about whether
>> 137 * we should do bottom half handling etc. Right now we
>> 138 * end up _always_ checking the bottom half, which is a
>> 139 * waste of time and is not what some drivers would
>> 140 * prefer.
>> 141 */
>> 142 int handle_IRQ_event(unsigned int irq, struct pt_regs * regs, struct irqaction * action)
>> 143 {
>> 144 int status = 1; /* Force the "do bottom halves" bit */
>> 145 int retval = 0;
>> 146
>> 147 if (!(action->flags & SA_INTERRUPT))
>> 148 local_irq_enable();
>> 149
>> 150 do {
>> 151 status |= action->flags;
>> 152 retval |= action->handler(irq, action->dev_id, regs);
>> 153 action = action->next;
>> 154 } while (action);
>> 155 if (status & SA_SAMPLE_RANDOM)
>> 156 add_interrupt_randomness(irq);
>> 157 local_irq_disable();
>> 158
>> 159 return retval;
>> 160 }
>> 161
>> 162 static void __report_bad_irq(int irq, irq_desc_t *desc, irqreturn_t action_ret)
>> 163 {
>> 164 struct irqaction *action;
>> 165
>> 166 if (action_ret != IRQ_HANDLED && action_ret != IRQ_NONE) {
>> 167 printk(KERN_ERR "irq event %d: bogus return value %x\n",
>> 168 irq, action_ret);
>> 169 } else {
>> 170 printk(KERN_ERR "irq %d: nobody cared!\n", irq);
>> 171 }
>> 172 dump_stack();
>> 173 printk(KERN_ERR "handlers:\n");
>> 174 action = desc->action;
>> 175 do {
>> 176 printk(KERN_ERR "[<%p>]", action->handler);
>> 177 print_symbol(" (%s)",
>> 178 (unsigned long)action->handler);
>> 179 printk("\n");
>> 180 action = action->next;
>> 181 } while (action);
>> 182 }
>> 183
>> 184 static void report_bad_irq(int irq, irq_desc_t *desc, irqreturn_t action_ret)
>> 185 {
>> 186 static int count = 100;
>> 187
>> 188 if (count) {
>> 189 count--;
>> 190 __report_bad_irq(irq, desc, action_ret);
>> 191 }
>> 192 }
>> 193
>> 194 static int noirqdebug;
>> 195
>> 196 static int __init noirqdebug_setup(char *str)
>> 197 {
>> 198 noirqdebug = 1;
>> 199 printk("IRQ lockup detection disabled\n");
>> 200 return 1;
>> 201 }
>> 202
>> 203 __setup("noirqdebug", noirqdebug_setup);
>> 204
>> 205 /*
>> 206 * If 99,900 of the previous 100,000 interrupts have not been handled then
>> 207 * assume that the IRQ is stuck in some manner. Drop a diagnostic and try to
>> 208 * turn the IRQ off.
>> 209 *
>> 210 * (The other 100-of-100,000 interrupts may have been a correctly-functioning
>> 211 * device sharing an IRQ with the failing one)
>> 212 *
>> 213 * Called under desc->lock
>> 214 */
>> 215 static void note_interrupt(int irq, irq_desc_t *desc, irqreturn_t action_ret)
>> 216 {
>> 217 if (action_ret != IRQ_HANDLED) {
>> 218 desc->irqs_unhandled++;
>> 219 if (action_ret != IRQ_NONE)
>> 220 report_bad_irq(irq, desc, action_ret);
>> 221 }
>> 222
>> 223 desc->irq_count++;
>> 224 if (desc->irq_count < 100000)
>> 225 return;
>> 226
>> 227 desc->irq_count = 0;
>> 228 if (desc->irqs_unhandled > 99900) {
>> 229 /*
>> 230 * The interrupt is stuck
>> 231 */
>> 232 __report_bad_irq(irq, desc, action_ret);
>> 233 /*
>> 234 * Now kill the IRQ
>> 235 */
>> 236 printk(KERN_EMERG "Disabling IRQ #%d\n", irq);
>> 237 desc->status |= IRQ_DISABLED;
>> 238 desc->handler->disable(irq);
>> 239 }
>> 240 desc->irqs_unhandled = 0;
>> 241 }
>> 242
>> 243 /*
>> 244 * Generic enable/disable code: this just calls
>> 245 * down into the PIC-specific version for the actual
>> 246 * hardware disable after having gotten the irq
>> 247 * controller lock.
>> 248 */
>> 249
>> 250 /**
>> 251 * disable_irq_nosync - disable an irq without waiting
>> 252 * @irq: Interrupt to disable
>> 253 *
>> 254 * Disable the selected interrupt line. Disables of an interrupt
>> 255 * stack. Unlike disable_irq(), this function does not ensure existing
>> 256 * instances of the IRQ handler have completed before returning.
>> 257 *
>> 258 * This function may be called from IRQ context.
>> 259 */
>> 260
>> 261 void inline disable_irq_nosync(unsigned int irq)
>> 262 {
>> 263 irq_desc_t *desc = irq_desc + irq;
>> 264 unsigned long flags;
>> 265
>> 266 spin_lock_irqsave(&desc->lock, flags);
>> 267 if (!desc->depth++) {
>> 268 desc->status |= IRQ_DISABLED;
>> 269 desc->handler->disable(irq);
>> 270 }
>> 271 spin_unlock_irqrestore(&desc->lock, flags);
>> 272 }
>> 273
>> 274 /**
>> 275 * disable_irq - disable an irq and wait for completion
>> 276 * @irq: Interrupt to disable
>> 277 *
>> 278 * Disable the selected interrupt line. Disables of an interrupt
>> 279 * stack. That is for two disables you need two enables. This
>> 280 * function waits for any pending IRQ handlers for this interrupt
>> 281 * to complete before returning. If you use this function while
>> 282 * holding a resource the IRQ handler may need you will deadlock.
>> 283 *
>> 284 * This function may be called - with care - from IRQ context.
>> 285 */
>> 286
>> 287 void disable_irq(unsigned int irq)
>> 288 {
>> 289 disable_irq_nosync(irq);
>> 290 synchronize_irq(irq);
>> 291 }
>> 292
>> 293 /**
>> 294 * enable_irq - enable interrupt handling on an irq
>> 295 * @irq: Interrupt to enable
>> 296 *
>> 297 * Re-enables the processing of interrupts on this IRQ line
>> 298 * providing no disable_irq calls are now in effect.
>> 299 *
>> 300 * This function may be called from IRQ context.
>> 301 */
>> 302
>> 303 void enable_irq(unsigned int irq)
>> 304 {
>> 305 irq_desc_t *desc = irq_desc + irq;
>> 306 unsigned long flags;
>> 307
>> 308 spin_lock_irqsave(&desc->lock, flags);
>> 309 switch (desc->depth) {
>> 310 case 1: {
>> 311 unsigned int status = desc->status & ~IRQ_DISABLED;
>> 312 desc->status = status;
>> 313 if ((status & (IRQ_PENDING | IRQ_REPLAY)) == IRQ_PENDING) {
>> 314 desc->status = status | IRQ_REPLAY;
>> 315 hw_resend_irq(desc->handler,irq);
>> 316 }
>> 317 desc->handler->enable(irq);
>> 318 /* fall-through */
>> 319 }
>> 320 default:
>> 321 desc->depth--;
>> 322 break;
>> 323 case 0:
>> 324 printk("enable_irq(%u) unbalanced from %p\n", irq,
>> 325 __builtin_return_address(0));
>> 326 }
>> 327 spin_unlock_irqrestore(&desc->lock, flags);
>> 328 }
>> 329
>> 330 /*
>> 331 * do_IRQ handles all normal device IRQ's (the special
>> 332 * SMP cross-CPU interrupts have their own specific
>> 333 * handlers).
>> 334 */
>> 335 asmlinkage unsigned int do_IRQ(int irq, struct pt_regs *regs)
>> 336 {
>> 337 /*
>> 338 * We ack quickly, we don't want the irq controller
>> 339 * thinking we're snobs just because some other CPU has
>> 340 * disabled global interrupts (we have already done the
>> 341 * INT_ACK cycles, it's too late to try to pretend to the
>> 342 * controller that we aren't taking the interrupt).
>> 343 *
>> 344 * 0 return value means that this irq is already being
>> 345 * handled by some other CPU. (or is disabled)
>> 346 */
>> 347 irq_desc_t *desc = irq_desc + irq;
>> 348 struct irqaction * action;
>> 349 unsigned int status;
>> 350
>> 351 irq_enter();
>> 352 kstat_this_cpu.irqs[irq]++;
>> 353 spin_lock(&desc->lock);
>> 354 desc->handler->ack(irq);
>> 355 /*
>> 356 REPLAY is when Linux resends an IRQ that was dropped earlier
>> 357 WAITING is used by probe to mark irqs that are being tested
>> 358 */
>> 359 status = desc->status & ~(IRQ_REPLAY | IRQ_WAITING);
>> 360 status |= IRQ_PENDING; /* we _want_ to handle it */
>> 361
>> 362 /*
>> 363 * If the IRQ is disabled for whatever reason, we cannot
>> 364 * use the action we have.
>> 365 */
>> 366 action = NULL;
>> 367 if (likely(!(status & (IRQ_DISABLED | IRQ_INPROGRESS)))) {
>> 368 action = desc->action;
>> 369 status &= ~IRQ_PENDING; /* we commit to handling */
>> 370 status |= IRQ_INPROGRESS; /* we are handling it */
>> 371 }
>> 372 desc->status = status;
>> 373
>> 374 /*
>> 375 * If there is no IRQ handler or it was disabled, exit early.
>> 376 Since we set PENDING, if another processor is handling
>> 377 a different instance of this same irq, the other processor
>> 378 will take care of it.
>> 379 */
>> 380 if (unlikely(!action))
>> 381 goto out;
>> 382
>> 383 /*
>> 384 * Edge triggered interrupts need to remember
>> 385 * pending events.
>> 386 * This applies to any hw interrupts that allow a second
>> 387 * instance of the same irq to arrive while we are in do_IRQ
>> 388 * or in the handler. But the code here only handles the _second_
>> 389 * instance of the irq, not the third or fourth. So it is mostly
>> 390 * useful for irq hardware that does not mask cleanly in an
>> 391 * SMP environment.
>> 392 */
>> 393 for (;;) {
>> 394 irqreturn_t action_ret;
>> 395
>> 396 spin_unlock(&desc->lock);
>> 397 action_ret = handle_IRQ_event(irq, regs, action);
>> 398 spin_lock(&desc->lock);
>> 399 if (!noirqdebug)
>> 400 note_interrupt(irq, desc, action_ret);
>> 401 if (likely(!(desc->status & IRQ_PENDING)))
>> 402 break;
>> 403 desc->status &= ~IRQ_PENDING;
>> 404 }
>> 405 desc->status &= ~IRQ_INPROGRESS;
>> 406
>> 407 out:
>> 408 /*
>> 409 * The ->end() handler has to deal with interrupts which got
>> 410 * disabled while the handler was running.
>> 411 */
>> 412 desc->handler->end(irq);
>> 413 spin_unlock(&desc->lock);
>> 414
>> 415 irq_exit();
>> 416
>> 417 return 1;
>> 418 }
>> 419
>> 420 /**
>> 421 * request_irq - allocate an interrupt line
>> 422 * @irq: Interrupt line to allocate
>> 423 * @handler: Function to be called when the IRQ occurs
>> 424 * @irqflags: Interrupt type flags
>> 425 * @devname: An ascii name for the claiming device
>> 426 * @dev_id: A cookie passed back to the handler function
>> 427 *
>> 428 * This call allocates interrupt resources and enables the
>> 429 * interrupt line and IRQ handling. From the point this
>> 430 * call is made your handler function may be invoked. Since
>> 431 * your handler function must clear any interrupt the board
>> 432 * raises, you must take care both to initialise your hardware
>> 433 * and to set up the interrupt handler in the right order.
>> 434 *
>> 435 * Dev_id must be globally unique. Normally the address of the
>> 436 * device data structure is used as the cookie. Since the handler
>> 437 * receives this value it makes sense to use it.
>> 438 *
>> 439 * If your interrupt is shared you must pass a non NULL dev_id
>> 440 * as this is required when freeing the interrupt.
>> 441 *
>> 442 * Flags:
>> 443 *
>> 444 * SA_SHIRQ Interrupt is shared
>> 445 *
>> 446 * SA_INTERRUPT Disable local interrupts while processing
>> 447 *
>> 448 * SA_SAMPLE_RANDOM The interrupt can be used for entropy
>> 449 *
>> 450 */
>> 451
>> 452 int request_irq(unsigned int irq,
>> 453 irqreturn_t (*handler)(int, void *, struct pt_regs *),
>> 454 unsigned long irqflags,
>> 455 const char * devname,
>> 456 void *dev_id)
>> 457 {
>> 458 int retval;
>> 459 struct irqaction * action;
>> 460
>> 461 #if 1
>> 462 /*
>> 463 * Sanity-check: shared interrupts should REALLY pass in
>> 464 * a real dev-ID, otherwise we'll have trouble later trying
>> 465 * to figure out which interrupt is which (messes up the
>> 466 * interrupt freeing logic etc).
>> 467 */
>> 468 if (irqflags & SA_SHIRQ) {
>> 469 if (!dev_id)
>> 470 printk("Bad boy: %s (at 0x%x) called us without a dev_id!\n", devname, (&irq)[-1]);
>> 471 }
>> 472 #endif
>> 473
>> 474 if (irq >= NR_IRQS)
>> 475 return -EINVAL;
>> 476 if (!handler)
>> 477 return -EINVAL;
>> 478
>> 479 action = (struct irqaction *)
>> 480 kmalloc(sizeof(struct irqaction), GFP_ATOMIC);
>> 481 if (!action)
>> 482 return -ENOMEM;
>> 483
>> 484 action->handler = handler;
>> 485 action->flags = irqflags;
>> 486 action->mask = 0;
>> 487 action->name = devname;
>> 488 action->next = NULL;
>> 489 action->dev_id = dev_id;
>> 490
>> 491 retval = setup_irq(irq, action);
>> 492 if (retval)
>> 493 kfree(action);
>> 494 return retval;
>> 495 }
>> 496
>> 497 EXPORT_SYMBOL(request_irq);
>> 498
>> 499 /**
>> 500 * free_irq - free an interrupt
>> 501 * @irq: Interrupt line to free
>> 502 * @dev_id: Device identity to free
>> 503 *
>> 504 * Remove an interrupt handler. The handler is removed and if the
>> 505 * interrupt line is no longer in use by any driver it is disabled.
>> 506 * On a shared IRQ the caller must ensure the interrupt is disabled
>> 507 * on the card it drives before calling this function. The function
>> 508 * does not return until any executing interrupts for this IRQ
>> 509 * have completed.
>> 510 *
>> 511 * This function must not be called from interrupt context.
>> 512 */
>> 513
>> 514 void free_irq(unsigned int irq, void *dev_id)
>> 515 {
>> 516 irq_desc_t *desc;
>> 517 struct irqaction **p;
>> 518 unsigned long flags;
>> 519
>> 520 if (irq >= NR_IRQS)
>> 521 return;
>> 522
>> 523 desc = irq_desc + irq;
>> 524 spin_lock_irqsave(&desc->lock,flags);
>> 525 p = &desc->action;
>> 526 for (;;) {
>> 527 struct irqaction * action = *p;
>> 528 if (action) {
>> 529 struct irqaction **pp = p;
>> 530 p = &action->next;
>> 531 if (action->dev_id != dev_id)
>> 532 continue;
>> 533
>> 534 /* Found it - now remove it from the list of entries */
>> 535 *pp = action->next;
>> 536 if (!desc->action) {
>> 537 desc->status |= IRQ_DISABLED;
>> 538 desc->handler->shutdown(irq);
>> 539 }
>> 540 spin_unlock_irqrestore(&desc->lock,flags);
>> 541
>> 542 /* Wait to make sure it's not being used on another CPU */
>> 543 synchronize_irq(irq);
>> 544 kfree(action);
>> 545 return;
>> 546 }
>> 547 printk("Trying to free free IRQ%d\n",irq);
>> 548 spin_unlock_irqrestore(&desc->lock,flags);
>> 549 return;
>> 550 }
>> 551 }
>> 552
>> 553 EXPORT_SYMBOL(free_irq);
>> 554
>> 555 /*
>> 556 * IRQ autodetection code..
>> 557 *
>> 558 * This depends on the fact that any interrupt that
>> 559 * comes in on to an unassigned handler will get stuck
>> 560 * with "IRQ_WAITING" cleared and the interrupt
>> 561 * disabled.
>> 562 */
>> 563
>> 564 static DECLARE_MUTEX(probe_sem);
>> 565
>> 566 /**
>> 567 * probe_irq_on - begin an interrupt autodetect
>> 568 *
>> 569 * Commence probing for an interrupt. The interrupts are scanned
>> 570 * and a mask of potential interrupt lines is returned.
>> 571 *
>> 572 */
>> 573
>> 574 unsigned long probe_irq_on(void)
>> 575 {
>> 576 unsigned int i;
>> 577 irq_desc_t *desc;
>> 578 unsigned long val;
>> 579 unsigned long delay;
>> 580
>> 581 down(&probe_sem);
>> 582 /*
>> 583 * something may have generated an irq long ago and we want to
>> 584 * flush such a longstanding irq before considering it as spurious.
>> 585 */
>> 586 for (i = NR_IRQS-1; i > 0; i--) {
>> 587 desc = irq_desc + i;
>> 588
>> 589 spin_lock_irq(&desc->lock);
>> 590 if (!irq_desc[i].action)
>> 591 irq_desc[i].handler->startup(i);
>> 592 spin_unlock_irq(&desc->lock);
>> 593 }
>> 594
>> 595 /* Wait for longstanding interrupts to trigger. */
>> 596 for (delay = jiffies + HZ/50; time_after(delay, jiffies); )
>> 597 /* about 20ms delay */ barrier();
>> 598
>> 599 /*
>> 600 * enable any unassigned irqs
>> 601 * (we must startup again here because if a longstanding irq
>> 602 * happened in the previous stage, it may have masked itself)
>> 603 */
>> 604 for (i = NR_IRQS-1; i > 0; i--) {
>> 605 desc = irq_desc + i;
>> 606
>> 607 spin_lock_irq(&desc->lock);
>> 608 if (!desc->action) {
>> 609 desc->status |= IRQ_AUTODETECT | IRQ_WAITING;
>> 610 if (desc->handler->startup(i))
>> 611 desc->status |= IRQ_PENDING;
>> 612 }
>> 613 spin_unlock_irq(&desc->lock);
>> 614 }
>> 615
>> 616 /*
>> 617 * Wait for spurious interrupts to trigger
>> 618 */
>> 619 for (delay = jiffies + HZ/10; time_after(delay, jiffies); )
>> 620 /* about 100ms delay */ barrier();
>> 621
>> 622 /*
>> 623 * Now filter out any obviously spurious interrupts
>> 624 */
>> 625 val = 0;
>> 626 for (i = 0; i < NR_IRQS; i++) {
>> 627 irq_desc_t *desc = irq_desc + i;
>> 628 unsigned int status;
>> 629
>> 630 spin_lock_irq(&desc->lock);
>> 631 status = desc->status;
>> 632
>> 633 if (status & IRQ_AUTODETECT) {
>> 634 /* It triggered already - consider it spurious. */
>> 635 if (!(status & IRQ_WAITING)) {
>> 636 desc->status = status & ~IRQ_AUTODETECT;
>> 637 desc->handler->shutdown(i);
>> 638 } else
>> 639 if (i < 32)
>> 640 val |= 1 << i;
>> 641 }
>> 642 spin_unlock_irq(&desc->lock);
>> 643 }
>> 644
>> 645 return val;
>> 646 }
>> 647
>> 648 EXPORT_SYMBOL(probe_irq_on);
>> 649
>> 650 /*
>> 651 * Return a mask of triggered interrupts (this
>> 652 * can handle only legacy ISA interrupts).
>> 653 */
>> 654
>> 655 /**
>> 656 * probe_irq_mask - scan a bitmap of interrupt lines
>> 657 * @val: mask of interrupts to consider
>> 658 *
>> 659 * Scan the ISA bus interrupt lines and return a bitmap of
>> 660 * active interrupts. The interrupt probe logic state is then
>> 661 * returned to its previous value.
>> 662 *
>> 663 * Note: we need to scan all the irq's even though we will
>> 664 * only return ISA irq numbers - just so that we reset them
>> 665 * all to a known state.
>> 666 */
>> 667 unsigned int probe_irq_mask(unsigned long val)
>> 668 {
>> 669 int i;
>> 670 unsigned int mask;
>> 671
>> 672 mask = 0;
>> 673 for (i = 0; i < NR_IRQS; i++) {
>> 674 irq_desc_t *desc = irq_desc + i;
>> 675 unsigned int status;
>> 676
>> 677 spin_lock_irq(&desc->lock);
>> 678 status = desc->status;
>> 679
>> 680 if (status & IRQ_AUTODETECT) {
>> 681 if (i < 16 && !(status & IRQ_WAITING))
>> 682 mask |= 1 << i;
>> 683
>> 684 desc->status = status & ~IRQ_AUTODETECT;
>> 685 desc->handler->shutdown(i);
>> 686 }
>> 687 spin_unlock_irq(&desc->lock);
>> 688 }
>> 689 up(&probe_sem);
>> 690
>> 691 return mask & val;
>> 692 }
>> 693
>> 694 /*
>> 695 * Return the one interrupt that triggered (this can
>> 696 * handle any interrupt source).
>> 697 */
>> 698
>> 699 /**
>> 700 * probe_irq_off - end an interrupt autodetect
>> 701 * @val: mask of potential interrupts (unused)
>> 702 *
>> 703 * Scans the unused interrupt lines and returns the line which
>> 704 * appears to have triggered the interrupt. If no interrupt was
>> 705 * found then zero is returned. If more than one interrupt is
>> 706 * found then minus the first candidate is returned to indicate
>> 707 * their is doubt.
>> 708 *
>> 709 * The interrupt probe logic state is returned to its previous
>> 710 * value.
>> 711 *
>> 712 * BUGS: When used in a module (which arguably shouldnt happen)
>> 713 * nothing prevents two IRQ probe callers from overlapping. The
>> 714 * results of this are non-optimal.
>> 715 */
>> 716
>> 717 int probe_irq_off(unsigned long val)
>> 718 {
>> 719 int i, irq_found, nr_irqs;
>> 720
>> 721 nr_irqs = 0;
>> 722 irq_found = 0;
>> 723 for (i = 0; i < NR_IRQS; i++) {
>> 724 irq_desc_t *desc = irq_desc + i;
>> 725 unsigned int status;
>> 726
>> 727 spin_lock_irq(&desc->lock);
>> 728 status = desc->status;
>> 729
>> 730 if (status & IRQ_AUTODETECT) {
>> 731 if (!(status & IRQ_WAITING)) {
>> 732 if (!nr_irqs)
>> 733 irq_found = i;
>> 734 nr_irqs++;
>> 735 }
>> 736 desc->status = status & ~IRQ_AUTODETECT;
>> 737 desc->handler->shutdown(i);
>> 738 }
>> 739 spin_unlock_irq(&desc->lock);
>> 740 }
>> 741 up(&probe_sem);
>> 742
>> 743 if (nr_irqs > 1)
>> 744 irq_found = -irq_found;
>> 745 return irq_found;
>> 746 }
>> 747
>> 748 EXPORT_SYMBOL(probe_irq_off);
>> 749
>> 750 /* this was setup_x86_irq but it seems pretty generic */
>> 751 int setup_irq(unsigned int irq, struct irqaction * new)
>> 752 {
>> 753 int shared = 0;
>> 754 unsigned long flags;
>> 755 struct irqaction *old, **p;
>> 756 irq_desc_t *desc = irq_desc + irq;
>> 757
>> 758 /*
>> 759 * Some drivers like serial.c use request_irq() heavily,
>> 760 * so we have to be careful not to interfere with a
>> 761 * running system.
>> 762 */
>> 763 if (new->flags & SA_SAMPLE_RANDOM) {
>> 764 /*
>> 765 * This function might sleep, we want to call it first,
>> 766 * outside of the atomic block.
>> 767 * Yes, this might clear the entropy pool if the wrong
>> 768 * driver is attempted to be loaded, without actually
>> 769 * installing a new handler, but is this really a problem,
>> 770 * only the sysadmin is able to do this.
>> 771 */
>> 772 rand_initialize_irq(irq);
>> 773 }
>> 774
>> 775 /*
>> 776 * The following block of code has to be executed atomically
>> 777 */
>> 778 spin_lock_irqsave(&desc->lock,flags);
>> 779 p = &desc->action;
>> 780 if ((old = *p) != NULL) {
>> 781 /* Can't share interrupts unless both agree to */
>> 782 if (!(old->flags & new->flags & SA_SHIRQ)) {
>> 783 spin_unlock_irqrestore(&desc->lock,flags);
>> 784 return -EBUSY;
>> 785 }
>> 786
>> 787 /* add new interrupt at end of irq queue */
>> 788 do {
>> 789 p = &old->next;
>> 790 old = *p;
>> 791 } while (old);
>> 792 shared = 1;
>> 793 }
>> 794
>> 795 *p = new;
>> 796
>> 797 if (!shared) {
>> 798 desc->depth = 0;
>> 799 desc->status &= ~(IRQ_DISABLED | IRQ_AUTODETECT | IRQ_WAITING | IRQ_INPROGRESS);
>> 800 desc->handler->startup(irq);
>> 801 }
>> 802 spin_unlock_irqrestore(&desc->lock,flags);
>> 803
>> 804 register_irq_proc(irq);
>> 805 return 0;
>> 806 }
>> 807
>> 808 void __init init_generic_irq(void)
>> 809 {
>> 810 int i;
>> 811
>> 812 for (i = 0; i < NR_IRQS; i++) {
>> 813 irq_desc[i].status = IRQ_DISABLED;
>> 814 irq_desc[i].action = NULL;
>> 815 irq_desc[i].depth = 1;
>> 816 irq_desc[i].handler = &no_irq_type;
>> 817 }
>> 818 }
>> 819
>> 820 EXPORT_SYMBOL(disable_irq_nosync);
>> 821 EXPORT_SYMBOL(disable_irq);
>> 822 EXPORT_SYMBOL(enable_irq);
>> 823 EXPORT_SYMBOL(probe_irq_mask);
>> 824
>> 825 static struct proc_dir_entry * root_irq_dir;
>> 826 static struct proc_dir_entry * irq_dir [NR_IRQS];
>> 827
>> 828 #define HEX_DIGITS 8
>> 829
>> 830 static unsigned int parse_hex_value (const char *buffer,
>> 831 unsigned long count, unsigned long *ret)
>> 832 {
>> 833 unsigned char hexnum [HEX_DIGITS];
>> 834 unsigned long value;
>> 835 int i;
>> 836
>> 837 if (!count)
>> 838 return -EINVAL;
>> 839 if (count > HEX_DIGITS)
>> 840 count = HEX_DIGITS;
>> 841 if (copy_from_user(hexnum, buffer, count))
>> 842 return -EFAULT;
>> 843
>> 844 /*
>> 845 * Parse the first 8 characters as a hex string, any non-hex char
>> 846 * is end-of-string. '00e1', 'e1', '00E1', 'E1' are all the same.
>> 847 */
>> 848 value = 0;
>> 849
>> 850 for (i = 0; i < count; i++) {
>> 851 unsigned int c = hexnum[i];
>> 852
>> 853 switch (c) {
>> 854 case '' ... '9': c -= ''; break;
>> 855 case 'a' ... 'f': c -= 'a'-10; break;
>> 856 case 'A' ... 'F': c -= 'A'-10; break;
>> 857 default:
>> 858 goto out;
>> 859 }
>> 860 value = (value << 4) | c;
>> 861 }
>> 862 out:
>> 863 *ret = value;
>> 864 return 0;
>> 865 }
>> 866
>> 867 #ifdef CONFIG_SMP
>> 868
>> 869 static struct proc_dir_entry * smp_affinity_entry [NR_IRQS];
>> 870
>> 871 static cpumask_t irq_affinity [NR_IRQS] = { [0 ... NR_IRQS-1] = ~0UL };
>> 872 static int irq_affinity_read_proc (char *page, char **start, off_t off,
>> 873 int count, int *eof, void *data)
>> 874 {
>> 875 int len, k;
>> 876 cpumask_t tmp = irq_affinity[(long)data];
>> 877
>> 878 if (count < HEX_DIGITS+1)
>> 879 return -EINVAL;
>> 880 for (k = 0; k < sizeof(cpumask_t)/sizeof(u16); ++k) {
>> 881 int j = sprintf(page, "%04hx", cpus_coerce(tmp));
>> 882 len += j;
>> 883 page += j;
>> 884 cpus_shift_right(tmp, tmp, 16);
>> 885 }
>> 886 len += sprintf(page, "\n");
>> 887 return len;
>> 888 }
>> 889
>> 890 static int irq_affinity_write_proc (struct file *file, const char *buffer,
>> 891 unsigned long count, void *data)
>> 892 {
>> 893 int irq = (long) data, full_count = count, err;
>> 894 cpumask_t new_value, tmp;
>> 895
>> 896 if (!irq_desc[irq].handler->set_affinity)
>> 897 return -EIO;
>> 898
>> 899 err = parse_hex_value(buffer, count, &new_value);
>> 900
>> 901 /*
>> 902 * Do not allow disabling IRQs completely - it's a too easy
>> 903 * way to make the system unusable accidentally :-) At least
>> 904 * one online CPU still has to be targeted.
>> 905 */
>> 906 cpus_and(tmp, tmp, cpu_online_map);
>> 907 if (cpus_empty(tmp))
>> 908 return -EINVAL;
>> 909
>> 910 irq_affinity[irq] = new_value;
>> 911 irq_desc[irq].handler->set_affinity(irq, new_value);
>> 912
>> 913 return full_count;
>> 914 }
>> 915
>> 916 #endif
>> 917
>> 918 static int prof_cpu_mask_read_proc (char *page, char **start, off_t off,
>> 919 int count, int *eof, void *data)
>> 920 {
>> 921 int len, k;
>> 922 cpumask_t *mask = (cpumask_t *)data, tmp;
10 923
11 void __init init_IRQ(void) !! 924 if (count < HEX_DIGITS+1)
>> 925 return -EINVAL;
>> 926 tmp = *mask;
>> 927
>> 928 for (k = 0; k < sizeof(cpumask_t)/sizeof(u16); ++k) {
>> 929 int j = sprintf(page, "%04hx", cpus_coerce(tmp));
>> 930 len += j;
>> 931 page += j;
>> 932 cpus_shift_right(tmp, tmp, 16);
>> 933 }
>> 934 len += sprintf(page, "\n");
>> 935 return len;
>> 936 }
>> 937
>> 938 static int prof_cpu_mask_write_proc (struct file *file, const char *buffer,
>> 939 unsigned long count, void *data)
12 { 940 {
13 irqchip_init(); !! 941 cpumask_t *mask = (cpumask_t *)data, new_value;
>> 942 unsigned long full_count = count, err;
>> 943
>> 944 err = parse_hex_value(buffer, count, &new_value);
>> 945 if (err)
>> 946 return err;
>> 947
>> 948 *mask = new_value;
>> 949 return full_count;
>> 950 }
>> 951
>> 952 #define MAX_NAMELEN 10
>> 953
>> 954 static void register_irq_proc (unsigned int irq)
>> 955 {
>> 956 char name [MAX_NAMELEN];
>> 957
>> 958 if (!root_irq_dir || (irq_desc[irq].handler == &no_irq_type) ||
>> 959 irq_dir[irq])
>> 960 return;
>> 961
>> 962 memset(name, 0, MAX_NAMELEN);
>> 963 sprintf(name, "%d", irq);
>> 964
>> 965 /* create /proc/irq/1234 */
>> 966 irq_dir[irq] = proc_mkdir(name, root_irq_dir);
>> 967
14 #ifdef CONFIG_SMP 968 #ifdef CONFIG_SMP
15 setup_smp_ipi(); !! 969 {
>> 970 struct proc_dir_entry *entry;
>> 971
>> 972 /* create /proc/irq/1234/smp_affinity */
>> 973 entry = create_proc_entry("smp_affinity", 0600, irq_dir[irq]);
>> 974
>> 975 if (entry) {
>> 976 entry->nlink = 1;
>> 977 entry->data = (void *)(long)irq;
>> 978 entry->read_proc = irq_affinity_read_proc;
>> 979 entry->write_proc = irq_affinity_write_proc;
>> 980 }
>> 981
>> 982 smp_affinity_entry[irq] = entry;
>> 983 }
16 #endif 984 #endif
>> 985 }
>> 986
>> 987 unsigned long prof_cpu_mask = -1;
>> 988
>> 989 void init_irq_proc (void)
>> 990 {
>> 991 struct proc_dir_entry *entry;
>> 992 int i;
>> 993
>> 994 /* create /proc/irq */
>> 995 root_irq_dir = proc_mkdir("irq", 0);
>> 996
>> 997 /* create /proc/irq/prof_cpu_mask */
>> 998 entry = create_proc_entry("prof_cpu_mask", 0600, root_irq_dir);
>> 999
>> 1000 if (!entry)
>> 1001 return;
>> 1002
>> 1003 entry->nlink = 1;
>> 1004 entry->data = (void *)&prof_cpu_mask;
>> 1005 entry->read_proc = prof_cpu_mask_read_proc;
>> 1006 entry->write_proc = prof_cpu_mask_write_proc;
>> 1007
>> 1008 /*
>> 1009 * Create entries for all existing IRQs.
>> 1010 */
>> 1011 for (i = 0; i < NR_IRQS; i++)
>> 1012 register_irq_proc(i);
17 } 1013 }
18 1014
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.