kernel/irq/chip.c

   1 /*
   2  * linux/kernel/irq/chip.c
   3  *
   4  * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
   5  * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
   6  *
   7  * This file contains the core interrupt handling code, for irq-chip
   8  * based architectures.
   9  *
  10  * Detailed information is available in Documentation/DocBook/genericirq
  11  */
  12
  13 #include <linux/irq.h>
  14 #include <linux/msi.h>
  15 #include <linux/module.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/kernel_stat.h>
  18
  19 #include <trace/events/irq.h>
  20
  21 #include "internals.h"
  22
  23 /**
  24  *      irq_set_chip - set the irq chip for an irq
  25  *      @irq:   irq number
  26  *      @chip:  pointer to irq chip description structure
  27  */
  28 int irq_set_chip(unsigned int irq, struct irq_chip *chip)
  29 {
  30         unsigned long flags;
  31         struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
  32
  33         if (!desc)
  34                 return -EINVAL;
  35
  36         if (!chip)
  37                 chip = &no_irq_chip;
  38
  39         desc->irq_data.chip = chip;
  40         irq_put_desc_unlock(desc, flags);
  41         /*
  42          * For !CONFIG_SPARSE_IRQ make the irq show up in
  43          * allocated_irqs.
  44          */
  45         irq_mark_irq(irq);
  46         return 0;
  47 }
  48 EXPORT_SYMBOL(irq_set_chip);
  49
  50 /**
  51  *      irq_set_type - set the irq trigger type for an irq
  52  *      @irq:   irq number
  53  *      @type:  IRQ_TYPE_{LEVEL,EDGE}_* value - see include/linux/irq.h
  54  */
  55 int irq_set_irq_type(unsigned int irq, unsigned int type)
  56 {
  57         unsigned long flags;
  58         struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
  59         int ret = 0;
  60
  61         if (!desc)
  62                 return -EINVAL;
  63
  64         type &= IRQ_TYPE_SENSE_MASK;
  65         ret = __irq_set_trigger(desc, irq, type);
  66         irq_put_desc_busunlock(desc, flags);
  67         return ret;
  68 }
  69 EXPORT_SYMBOL(irq_set_irq_type);
  70
  71 /**
  72  *      irq_set_handler_data - set irq handler data for an irq
  73  *      @irq:   Interrupt number
  74  *      @data:  Pointer to interrupt specific data
  75  *
  76  *      Set the hardware irq controller data for an irq
  77  */
  78 int irq_set_handler_data(unsigned int irq, void *data)
  79 {
  80         unsigned long flags;
  81         struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
  82
  83         if (!desc)
  84                 return -EINVAL;
  85         desc->irq_data.handler_data = data;
  86         irq_put_desc_unlock(desc, flags);
  87         return 0;
  88 }
  89 EXPORT_SYMBOL(irq_set_handler_data);
  90
  91 /**
  92  *      irq_set_msi_desc_off - set MSI descriptor data for an irq at offset
  93  *      @irq_base:      Interrupt number base
  94  *      @irq_offset:    Interrupt number offset
  95  *      @entry:         Pointer to MSI descriptor data
  96  *
  97  *      Set the MSI descriptor entry for an irq at offset
  98  */
  99 int irq_set_msi_desc_off(unsigned int irq_base, unsigned int irq_offset,
 100                          struct msi_desc *entry)
 101 {
 102         unsigned long flags;
 103         struct irq_desc *desc = irq_get_desc_lock(irq_base + irq_offset, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
 104
 105         if (!desc)
 106                 return -EINVAL;
 107         desc->irq_data.msi_desc = entry;
 108         if (entry && !irq_offset)
 109                 entry->irq = irq_base;
 110         irq_put_desc_unlock(desc, flags);
 111         return 0;
 112 }
 113
 114 /**
 115  *      irq_set_msi_desc - set MSI descriptor data for an irq
 116  *      @irq:   Interrupt number
 117  *      @entry: Pointer to MSI descriptor data
 118  *
 119  *      Set the MSI descriptor entry for an irq
 120  */
 121 int irq_set_msi_desc(unsigned int irq, struct msi_desc *entry)
 122 {
 123         return irq_set_msi_desc_off(irq, 0, entry);
 124 }
 125
 126 /**
 127  *      irq_set_chip_data - set irq chip data for an irq
 128  *      @irq:   Interrupt number
 129  *      @data:  Pointer to chip specific data
 130  *
 131  *      Set the hardware irq chip data for an irq
 132  */
 133 int irq_set_chip_data(unsigned int irq, void *data)
 134 {
 135         unsigned long flags;
 136         struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
 137
 138         if (!desc)
 139                 return -EINVAL;
 140         desc->irq_data.chip_data = data;
 141         irq_put_desc_unlock(desc, flags);
 142         return 0;
 143 }
 144 EXPORT_SYMBOL(irq_set_chip_data);
 145
 146 struct irq_data *irq_get_irq_data(unsigned int irq)
 147 {
 148         struct irq_desc *desc = irq_to_desc(irq);
 149
 150         return desc ? &desc->irq_data : NULL;
 151 }
 152 EXPORT_SYMBOL_GPL(irq_get_irq_data);
 153
 154 static void irq_state_clr_disabled(struct irq_desc *desc)
 155 {
 156         irqd_clear(&desc->irq_data, IRQD_IRQ_DISABLED);
 157 }
 158
 159 static void irq_state_set_disabled(struct irq_desc *desc)
 160 {
 161         irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
 162 }
 163
 164 static void irq_state_clr_masked(struct irq_desc *desc)
 165 {
 166         irqd_clear(&desc->irq_data, IRQD_IRQ_MASKED);
 167 }
 168
 169 static void irq_state_set_masked(struct irq_desc *desc)
 170 {
 171         irqd_set(&desc->irq_data, IRQD_IRQ_MASKED);
 172 }
 173
 174 int irq_startup(struct irq_desc *desc, bool resend)
 175 {
 176         int ret = 0;
 177
 178         irq_state_clr_disabled(desc);
 179         desc->depth = 0;
 180
 181         if (desc->irq_data.chip->irq_startup) {
 182                 ret = desc->irq_data.chip->irq_startup(&desc->irq_data);
 183                 irq_state_clr_masked(desc);
 184         } else {
 185                 irq_enable(desc);
 186         }
 187         if (resend)
 188                 check_irq_resend(desc, desc->irq_data.irq);
 189         return ret;
 190 }
 191
 192 void irq_shutdown(struct irq_desc *desc)
 193 {
 194         irq_state_set_disabled(desc);
 195         desc->depth = 1;
 196         if (desc->irq_data.chip->irq_shutdown)
 197                 desc->irq_data.chip->irq_shutdown(&desc->irq_data);
 198         else if (desc->irq_data.chip->irq_disable)
 199                 desc->irq_data.chip->irq_disable(&desc->irq_data);
 200         else
 201                 desc->irq_data.chip->irq_mask(&desc->irq_data);
 202         irq_state_set_masked(desc);
 203 }
 204
 205 void irq_enable(struct irq_desc *desc)
 206 {
 207         irq_state_clr_disabled(desc);
 208         if (desc->irq_data.chip->irq_enable)
 209                 desc->irq_data.chip->irq_enable(&desc->irq_data);
 210         else
 211                 desc->irq_data.chip->irq_unmask(&desc->irq_data);
 212         irq_state_clr_masked(desc);
 213 }
 214
 215 /**
 216  * irq_disable - Mark interrupt disabled
 217  * @desc:       irq descriptor which should be disabled
 218  *
 219  * If the chip does not implement the irq_disable callback, we
 220  * use a lazy disable approach. That means we mark the interrupt
 221  * disabled, but leave the hardware unmasked. That's an
 222  * optimization because we avoid the hardware access for the
 223  * common case where no interrupt happens after we marked it
 224  * disabled. If an interrupt happens, then the interrupt flow
 225  * handler masks the line at the hardware level and marks it
 226  * pending.
 227  */
 228 void irq_disable(struct irq_desc *desc)
 229 {
 230         irq_state_set_disabled(desc);
 231         if (desc->irq_data.chip->irq_disable) {
 232                 desc->irq_data.chip->irq_disable(&desc->irq_data);
 233                 irq_state_set_masked(desc);
 234         }
 235 }
 236
 237 void irq_percpu_enable(struct irq_desc *desc, unsigned int cpu)
 238 {
 239         if (desc->irq_data.chip->irq_enable)
 240                 desc->irq_data.chip->irq_enable(&desc->irq_data);
 241         else
 242                 desc->irq_data.chip->irq_unmask(&desc->irq_data);
 243         cpumask_set_cpu(cpu, desc->percpu_enabled);
 244 }
 245
 246 void irq_percpu_disable(struct irq_desc *desc, unsigned int cpu)
 247 {
 248         if (desc->irq_data.chip->irq_disable)
 249                 desc->irq_data.chip->irq_disable(&desc->irq_data);
 250         else
 251                 desc->irq_data.chip->irq_mask(&desc->irq_data);
 252         cpumask_clear_cpu(cpu, desc->percpu_enabled);
 253 }
 254
 255 static inline void mask_ack_irq(struct irq_desc *desc)
 256 {
 257         if (desc->irq_data.chip->irq_mask_ack)
 258                 desc->irq_data.chip->irq_mask_ack(&desc->irq_data);
 259         else {
 260                 desc->irq_data.chip->irq_mask(&desc->irq_data);
 261                 if (desc->irq_data.chip->irq_ack)
 262                         desc->irq_data.chip->irq_ack(&desc->irq_data);
 263         }
 264         irq_state_set_masked(desc);
 265 }
 266
 267 void mask_irq(struct irq_desc *desc)
 268 {
 269         if (desc->irq_data.chip->irq_mask) {
 270                 desc->irq_data.chip->irq_mask(&desc->irq_data);
 271                 irq_state_set_masked(desc);
 272         }
 273 }
 274
 275 void unmask_irq(struct irq_desc *desc)
 276 {
 277         if (desc->irq_data.chip->irq_unmask) {
 278                 desc->irq_data.chip->irq_unmask(&desc->irq_data);
 279                 irq_state_clr_masked(desc);
 280         }
 281 }
 282
 283 void unmask_threaded_irq(struct irq_desc *desc)
 284 {
 285         struct irq_chip *chip = desc->irq_data.chip;
 286
 287         if (chip->flags & IRQCHIP_EOI_THREADED)
 288                 chip->irq_eoi(&desc->irq_data);
 289
 290         if (chip->irq_unmask) {
 291                 chip->irq_unmask(&desc->irq_data);
 292                 irq_state_clr_masked(desc);
 293         }
 294 }
 295
 296 /*
 297  *      handle_nested_irq - Handle a nested irq from a irq thread
 298  *      @irq:   the interrupt number
 299  *
 300  *      Handle interrupts which are nested into a threaded interrupt
 301  *      handler. The handler function is called inside the calling
 302  *      threads context.
 303  */
 304 void handle_nested_irq(unsigned int irq)
 305 {
 306         struct irq_desc *desc = irq_to_desc(irq);
 307         struct irqaction *action;
 308         irqreturn_t action_ret;
 309
 310         might_sleep();
 311
 312         raw_spin_lock_irq(&desc->lock);
 313
 314         desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
 315         kstat_incr_irqs_this_cpu(irq, desc);
 316
 317         action = desc->action;
 318         if (unlikely(!action || irqd_irq_disabled(&desc->irq_data))) {
 319                 desc->istate |= IRQS_PENDING;
 320                 goto out_unlock;
 321         }
 322
 323         irqd_set(&desc->irq_data, IRQD_IRQ_INPROGRESS);
 324         raw_spin_unlock_irq(&desc->lock);
 325
 326         action_ret = action->thread_fn(action->irq, action->dev_id);
 327         if (!noirqdebug)
 328                 note_interrupt(irq, desc, action_ret);
 329
 330         raw_spin_lock_irq(&desc->lock);
 331         irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
 332
 333 out_unlock:
 334         raw_spin_unlock_irq(&desc->lock);
 335 }
 336 EXPORT_SYMBOL_GPL(handle_nested_irq);
 337
 338 static bool irq_check_poll(struct irq_desc *desc)
 339 {
 340         if (!(desc->istate & IRQS_POLL_INPROGRESS))
 341                 return false;
 342         return irq_wait_for_poll(desc);
 343 }
 344
 345 static bool irq_may_run(struct irq_desc *desc)
 346 {
 347         unsigned int mask = IRQD_IRQ_INPROGRESS | IRQD_WAKEUP_ARMED;
 348
 349         /*
 350          * If the interrupt is not in progress and is not an armed
 351          * wakeup interrupt, proceed.
 352          */
 353         if (!irqd_has_set(&desc->irq_data, mask))
 354                 return true;
 355
 356         /*
 357          * If the interrupt is an armed wakeup source, mark it pending
 358          * and suspended, disable it and notify the pm core about the
 359          * event.
 360          */
 361         if (irq_pm_check_wakeup(desc))
 362                 return false;
 363
 364         /*
 365          * Handle a potential concurrent poll on a different core.
 366          */
 367         return irq_check_poll(desc);
 368 }
 369
 370 /**
 371  *      handle_simple_irq - Simple and software-decoded IRQs.
 372  *      @irq:   the interrupt number
 373  *      @desc:  the interrupt description structure for this irq
 374  *
 375  *      Simple interrupts are either sent from a demultiplexing interrupt
 376  *      handler or come from hardware, where no interrupt hardware control
 377  *      is necessary.
 378  *
 379  *      Note: The caller is expected to handle the ack, clear, mask and
 380  *      unmask issues if necessary.
 381  */
 382 void
 383 handle_simple_irq(unsigned int irq, struct irq_desc *desc)
 384 {
 385         raw_spin_lock(&desc->lock);
 386
 387         if (!irq_may_run(desc))
 388                 goto out_unlock;
 389
 390         desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
 391         kstat_incr_irqs_this_cpu(irq, desc);
 392
 393         if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data))) {
 394                 desc->istate |= IRQS_PENDING;
 395                 goto out_unlock;
 396         }
 397
 398         handle_irq_event(desc);
 399
 400 out_unlock:
 401         raw_spin_unlock(&desc->lock);
 402 }
 403 EXPORT_SYMBOL_GPL(handle_simple_irq);
 404
 405 /*
 406  * Called unconditionally from handle_level_irq() and only for oneshot
 407  * interrupts from handle_fasteoi_irq()
 408  */
 409 static void cond_unmask_irq(struct irq_desc *desc)
 410 {
 411         /*
 412          * We need to unmask in the following cases:
 413          * - Standard level irq (IRQF_ONESHOT is not set)
 414          * - Oneshot irq which did not wake the thread (caused by a
 415          *   spurious interrupt or a primary handler handling it
 416          *   completely).
 417          */
 418         if (!irqd_irq_disabled(&desc->irq_data) &&
 419             irqd_irq_masked(&desc->irq_data) && !desc->threads_oneshot)
 420                 unmask_irq(desc);
 421 }
 422
 423 /**
 424  *      handle_level_irq - Level type irq handler
 425  *      @irq:   the interrupt number
 426  *      @desc:  the interrupt description structure for this irq
 427  *
 428  *      Level type interrupts are active as long as the hardware line has
 429  *      the active level. This may require to mask the interrupt and unmask
 430  *      it after the associated handler has acknowledged the device, so the
 431  *      interrupt line is back to inactive.
 432  */
 433 void
 434 handle_level_irq(unsigned int irq, struct irq_desc *desc)
 435 {
 436         raw_spin_lock(&desc->lock);
 437         mask_ack_irq(desc);
 438
 439         if (!irq_may_run(desc))
 440                 goto out_unlock;
 441
 442         desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
 443         kstat_incr_irqs_this_cpu(irq, desc);
 444
 445         /*
 446          * If its disabled or no action available
 447          * keep it masked and get out of here
 448          */
 449         if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data))) {
 450                 desc->istate |= IRQS_PENDING;
 451                 goto out_unlock;
 452         }
 453
 454         handle_irq_event(desc);
 455
 456         cond_unmask_irq(desc);
 457
 458 out_unlock:
 459         raw_spin_unlock(&desc->lock);
 460 }
 461 EXPORT_SYMBOL_GPL(handle_level_irq);
 462
 463 #ifdef CONFIG_IRQ_PREFLOW_FASTEOI
 464 static inline void preflow_handler(struct irq_desc *desc)
 465 {
 466         if (desc->preflow_handler)
 467                 desc->preflow_handler(&desc->irq_data);
 468 }
 469 #else
 470 static inline void preflow_handler(struct irq_desc *desc) { }
 471 #endif
 472
 473 static void cond_unmask_eoi_irq(struct irq_desc *desc, struct irq_chip *chip)
 474 {
 475         if (!(desc->istate & IRQS_ONESHOT)) {
 476                 chip->irq_eoi(&desc->irq_data);
 477                 return;
 478         }
 479         /*
 480          * We need to unmask in the following cases:
 481          * - Oneshot irq which did not wake the thread (caused by a
 482          *   spurious interrupt or a primary handler handling it
 483          *   completely).
 484          */
 485         if (!irqd_irq_disabled(&desc->irq_data) &&
 486             irqd_irq_masked(&desc->irq_data) && !desc->threads_oneshot) {
 487                 chip->irq_eoi(&desc->irq_data);
 488                 unmask_irq(desc);
 489         } else if (!(chip->flags & IRQCHIP_EOI_THREADED)) {
 490                 chip->irq_eoi(&desc->irq_data);
 491         }
 492 }
 493
 494 /**
 495  *      handle_fasteoi_irq - irq handler for transparent controllers
 496  *      @irq:   the interrupt number
 497  *      @desc:  the interrupt description structure for this irq
 498  *
 499  *      Only a single callback will be issued to the chip: an ->eoi()
 500  *      call when the interrupt has been serviced. This enables support
 501  *      for modern forms of interrupt handlers, which handle the flow
 502  *      details in hardware, transparently.
 503  */
 504 void
 505 handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
 506 {
 507         struct irq_chip *chip = desc->irq_data.chip;
 508
 509         raw_spin_lock(&desc->lock);
 510
 511         if (!irq_may_run(desc))
 512                 goto out;
 513
 514         desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
 515         kstat_incr_irqs_this_cpu(irq, desc);
 516
 517         /*
 518          * If its disabled or no action available
 519          * then mask it and get out of here:
 520          */
 521         if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data))) {
 522                 desc->istate |= IRQS_PENDING;
 523                 mask_irq(desc);
 524                 goto out;
 525         }
 526
 527         if (desc->istate & IRQS_ONESHOT)
 528                 mask_irq(desc);
 529
 530         preflow_handler(desc);
 531         handle_irq_event(desc);
 532
 533         cond_unmask_eoi_irq(desc, chip);
 534
 535         raw_spin_unlock(&desc->lock);
 536         return;
 537 out:
 538         if (!(chip->flags & IRQCHIP_EOI_IF_HANDLED))
 539                 chip->irq_eoi(&desc->irq_data);
 540         raw_spin_unlock(&desc->lock);
 541 }
 542 EXPORT_SYMBOL_GPL(handle_fasteoi_irq);
 543
 544 /**
 545  *      handle_edge_irq - edge type IRQ handler
 546  *      @irq:   the interrupt number
 547  *      @desc:  the interrupt description structure for this irq
 548  *
 549  *      Interrupt occures on the falling and/or rising edge of a hardware
 550  *      signal. The occurrence is latched into the irq controller hardware
 551  *      and must be acked in order to be reenabled. After the ack another
 552  *      interrupt can happen on the same source even before the first one
 553  *      is handled by the associated event handler. If this happens it
 554  *      might be necessary to disable (mask) the interrupt depending on the
 555  *      controller hardware. This requires to reenable the interrupt inside
 556  *      of the loop which handles the interrupts which have arrived while
 557  *      the handler was running. If all pending interrupts are handled, the
 558  *      loop is left.
 559  */
 560 void
 561 handle_edge_irq(unsigned int irq, struct irq_desc *desc)
 562 {
 563         raw_spin_lock(&desc->lock);
 564
 565         desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
 566
 567         if (!irq_may_run(desc)) {
 568                 desc->istate |= IRQS_PENDING;
 569                 mask_ack_irq(desc);
 570                 goto out_unlock;
 571         }
 572
 573         /*
 574          * If its disabled or no action available then mask it and get
 575          * out of here.
 576          */
 577         if (irqd_irq_disabled(&desc->irq_data) || !desc->action) {
 578                 desc->istate |= IRQS_PENDING;
 579                 mask_ack_irq(desc);
 580                 goto out_unlock;
 581         }
 582
 583         kstat_incr_irqs_this_cpu(irq, desc);
 584
 585         /* Start handling the irq */
 586         desc->irq_data.chip->irq_ack(&desc->irq_data);
 587
 588         do {
 589                 if (unlikely(!desc->action)) {
 590                         mask_irq(desc);
 591                         goto out_unlock;
 592                 }
 593
 594                 /*
 595                  * When another irq arrived while we were handling
 596                  * one, we could have masked the irq.
 597                  * Renable it, if it was not disabled in meantime.
 598                  */
 599                 if (unlikely(desc->istate & IRQS_PENDING)) {
 600                         if (!irqd_irq_disabled(&desc->irq_data) &&
 601                             irqd_irq_masked(&desc->irq_data))
 602                                 unmask_irq(desc);
 603                 }
 604
 605                 handle_irq_event(desc);
 606
 607         } while ((desc->istate & IRQS_PENDING) &&
 608                  !irqd_irq_disabled(&desc->irq_data));
 609
 610 out_unlock:
 611         raw_spin_unlock(&desc->lock);
 612 }
 613 EXPORT_SYMBOL(handle_edge_irq);
 614
 615 #ifdef CONFIG_IRQ_EDGE_EOI_HANDLER
 616 /**
 617  *      handle_edge_eoi_irq - edge eoi type IRQ handler
 618  *      @irq:   the interrupt number
 619  *      @desc:  the interrupt description structure for this irq
 620  *
 621  * Similar as the above handle_edge_irq, but using eoi and w/o the
 622  * mask/unmask logic.
 623  */
 624 void handle_edge_eoi_irq(unsigned int irq, struct irq_desc *desc)
 625 {
 626         struct irq_chip *chip = irq_desc_get_chip(desc);
 627
 628         raw_spin_lock(&desc->lock);
 629
 630         desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
 631
 632         if (!irq_may_run(desc)) {
 633                 desc->istate |= IRQS_PENDING;
 634                 goto out_eoi;
 635         }
 636
 637         /*
 638          * If its disabled or no action available then mask it and get
 639          * out of here.
 640          */
 641         if (irqd_irq_disabled(&desc->irq_data) || !desc->action) {
 642                 desc->istate |= IRQS_PENDING;
 643                 goto out_eoi;
 644         }
 645
 646         kstat_incr_irqs_this_cpu(irq, desc);
 647
 648         do {
 649                 if (unlikely(!desc->action))
 650                         goto out_eoi;
 651
 652                 handle_irq_event(desc);
 653
 654         } while ((desc->istate & IRQS_PENDING) &&
 655                  !irqd_irq_disabled(&desc->irq_data));
 656
 657 out_eoi:
 658         chip->irq_eoi(&desc->irq_data);
 659         raw_spin_unlock(&desc->lock);
 660 }
 661 #endif
 662
 663 /**
 664  *      handle_percpu_irq - Per CPU local irq handler
 665  *      @irq:   the interrupt number
 666  *      @desc:  the interrupt description structure for this irq
 667  *
 668  *      Per CPU interrupts on SMP machines without locking requirements
 669  */
 670 void
 671 handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
 672 {
 673         struct irq_chip *chip = irq_desc_get_chip(desc);
 674
 675         kstat_incr_irqs_this_cpu(irq, desc);
 676
 677         if (chip->irq_ack)
 678                 chip->irq_ack(&desc->irq_data);
 679
 680         handle_irq_event_percpu(desc, desc->action);
 681
 682         if (chip->irq_eoi)
 683                 chip->irq_eoi(&desc->irq_data);
 684 }
 685
 686 /**
 687  * handle_percpu_devid_irq - Per CPU local irq handler with per cpu dev ids
 688  * @irq:        the interrupt number
 689  * @desc:       the interrupt description structure for this irq
 690  *
 691  * Per CPU interrupts on SMP machines without locking requirements. Same as
 692  * handle_percpu_irq() above but with the following extras:
 693  *
 694  * action->percpu_dev_id is a pointer to percpu variables which
 695  * contain the real device id for the cpu on which this handler is
 696  * called
 697  */
 698 void handle_percpu_devid_irq(unsigned int irq, struct irq_desc *desc)
 699 {
 700         struct irq_chip *chip = irq_desc_get_chip(desc);
 701         struct irqaction *action = desc->action;
 702         void *dev_id = raw_cpu_ptr(action->percpu_dev_id);
 703         irqreturn_t res;
 704
 705         kstat_incr_irqs_this_cpu(irq, desc);
 706
 707         if (chip->irq_ack)
 708                 chip->irq_ack(&desc->irq_data);
 709
 710         trace_irq_handler_entry(irq, action);
 711         res = action->handler(irq, dev_id);
 712         trace_irq_handler_exit(irq, action, res);
 713
 714         if (chip->irq_eoi)
 715                 chip->irq_eoi(&desc->irq_data);
 716 }
 717
 718 void
 719 __irq_set_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
 720                   const char *name)
 721 {
 722         unsigned long flags;
 723         struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, 0);
 724
 725         if (!desc)
 726                 return;
 727
 728         if (!handle) {
 729                 handle = handle_bad_irq;
 730         } else {
 731                 if (WARN_ON(desc->irq_data.chip == &no_irq_chip))
 732                         goto out;
 733         }
 734
 735         /* Uninstall? */
 736         if (handle == handle_bad_irq) {
 737                 if (desc->irq_data.chip != &no_irq_chip)
 738                         mask_ack_irq(desc);
 739                 irq_state_set_disabled(desc);
 740                 desc->depth = 1;
 741         }
 742         desc->handle_irq = handle;
 743         desc->name = name;
 744
 745         if (handle != handle_bad_irq && is_chained) {
 746                 irq_settings_set_noprobe(desc);
 747                 irq_settings_set_norequest(desc);
 748                 irq_settings_set_nothread(desc);
 749                 irq_startup(desc, true);
 750         }
 751 out:
 752         irq_put_desc_busunlock(desc, flags);
 753 }
 754 EXPORT_SYMBOL_GPL(__irq_set_handler);
 755
 756 void
 757 irq_set_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
 758                               irq_flow_handler_t handle, const char *name)
 759 {
 760         irq_set_chip(irq, chip);
 761         __irq_set_handler(irq, handle, 0, name);
 762 }
 763 EXPORT_SYMBOL_GPL(irq_set_chip_and_handler_name);
 764
 765 void irq_modify_status(unsigned int irq, unsigned long clr, unsigned long set)
 766 {
 767         unsigned long flags;
 768         struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
 769
 770         if (!desc)
 771                 return;
 772         irq_settings_clr_and_set(desc, clr, set);
 773
 774         irqd_clear(&desc->irq_data, IRQD_NO_BALANCING | IRQD_PER_CPU |
 775                    IRQD_TRIGGER_MASK | IRQD_LEVEL | IRQD_MOVE_PCNTXT);
 776         if (irq_settings_has_no_balance_set(desc))
 777                 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
 778         if (irq_settings_is_per_cpu(desc))
 779                 irqd_set(&desc->irq_data, IRQD_PER_CPU);
 780         if (irq_settings_can_move_pcntxt(desc))
 781                 irqd_set(&desc->irq_data, IRQD_MOVE_PCNTXT);
 782         if (irq_settings_is_level(desc))
 783                 irqd_set(&desc->irq_data, IRQD_LEVEL);
 784
 785         irqd_set(&desc->irq_data, irq_settings_get_trigger_mask(desc));
 786
 787         irq_put_desc_unlock(desc, flags);
 788 }
 789 EXPORT_SYMBOL_GPL(irq_modify_status);
 790
 791 /**
 792  *      irq_cpu_online - Invoke all irq_cpu_online functions.
 793  *
 794  *      Iterate through all irqs and invoke the chip.irq_cpu_online()
 795  *      for each.
 796  */
 797 void irq_cpu_online(void)
 798 {
 799         struct irq_desc *desc;
 800         struct irq_chip *chip;
 801         unsigned long flags;
 802         unsigned int irq;
 803
 804         for_each_active_irq(irq) {
 805                 desc = irq_to_desc(irq);
 806                 if (!desc)
 807                         continue;
 808
 809                 raw_spin_lock_irqsave(&desc->lock, flags);
 810
 811                 chip = irq_data_get_irq_chip(&desc->irq_data);
 812                 if (chip && chip->irq_cpu_online &&
 813                     (!(chip->flags & IRQCHIP_ONOFFLINE_ENABLED) ||
 814                      !irqd_irq_disabled(&desc->irq_data)))
 815                         chip->irq_cpu_online(&desc->irq_data);
 816
 817                 raw_spin_unlock_irqrestore(&desc->lock, flags);
 818         }
 819 }
 820
 821 /**
 822  *      irq_cpu_offline - Invoke all irq_cpu_offline functions.
 823  *
 824  *      Iterate through all irqs and invoke the chip.irq_cpu_offline()
 825  *      for each.
 826  */
 827 void irq_cpu_offline(void)
 828 {
 829         struct irq_desc *desc;
 830         struct irq_chip *chip;
 831         unsigned long flags;
 832         unsigned int irq;
 833
 834         for_each_active_irq(irq) {
 835                 desc = irq_to_desc(irq);
 836                 if (!desc)
 837                         continue;
 838
 839                 raw_spin_lock_irqsave(&desc->lock, flags);
 840
 841                 chip = irq_data_get_irq_chip(&desc->irq_data);
 842                 if (chip && chip->irq_cpu_offline &&
 843                     (!(chip->flags & IRQCHIP_ONOFFLINE_ENABLED) ||
 844                      !irqd_irq_disabled(&desc->irq_data)))
 845                         chip->irq_cpu_offline(&desc->irq_data);
 846
 847                 raw_spin_unlock_irqrestore(&desc->lock, flags);
 848         }
 849 }