kernel/irq/dummychip.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
   4  * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
   5  *
   6  * This file contains the dummy interrupt chip implementation
   7  */
   8 #include <linux/interrupt.h>
   9 #include <linux/irq.h>
  10 #include <linux/export.h>
  11
  12 #include "internals.h"
  13
  14 /*
  15  * What should we do if we get a hw irq event on an illegal vector?
  16  * Each architecture has to answer this themself.
  17  */
  18 static void ack_bad(struct irq_data *data)
  19 {
  20         struct irq_desc *desc = irq_data_to_desc(data);
  21
  22         print_irq_desc(data->irq, desc);
  23         ack_bad_irq(data->irq);
  24 }
  25
  26 /*
  27  * NOP functions
  28  */
  29 static void noop(struct irq_data *data) { }
  30
  31 static unsigned int noop_ret(struct irq_data *data)
  32 {
  33         return 0;
  34 }
  35
  36 /*
  37  * Generic no controller implementation
  38  */
  39 struct irq_chip no_irq_chip = {
  40         .name           = "none",
  41         .irq_startup    = noop_ret,
  42         .irq_shutdown   = noop,
  43         .irq_enable     = noop,
  44         .irq_disable    = noop,
  45         .irq_ack        = ack_bad,
  46         .flags          = IRQCHIP_SKIP_SET_WAKE,
  47 };
  48
  49 /*
  50  * Generic dummy implementation which can be used for
  51  * real dumb interrupt sources
  52  */
  53 struct irq_chip dummy_irq_chip = {
  54         .name           = "dummy",
  55         .irq_startup    = noop_ret,
  56         .irq_shutdown   = noop,
  57         .irq_enable     = noop,
  58         .irq_disable    = noop,
  59         .irq_ack        = noop,
  60         .irq_mask       = noop,
  61         .irq_unmask     = noop,
  62         .flags          = IRQCHIP_SKIP_SET_WAKE,
  63 };
  64 EXPORT_SYMBOL_GPL(dummy_irq_chip);