resend.c 1.8 KB

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  1. /*
  2. * linux/kernel/irq/resend.c
  3. *
  4. * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
  5. * Copyright (C) 2005-2006, Thomas Gleixner
  6. *
  7. * This file contains the IRQ-resend code
  8. *
  9. * If the interrupt is waiting to be processed, we try to re-run it.
  10. * We can't directly run it from here since the caller might be in an
  11. * interrupt-protected region. Not all irq controller chips can
  12. * retrigger interrupts at the hardware level, so in those cases
  13. * we allow the resending of IRQs via a tasklet.
  14. */
  15. #include <linux/irq.h>
  16. #include <linux/module.h>
  17. #include <linux/random.h>
  18. #include <linux/interrupt.h>
  19. #include "internals.h"
  20. #ifdef CONFIG_HARDIRQS_SW_RESEND
  21. /* Bitmap to handle software resend of interrupts: */
  22. static DECLARE_BITMAP(irqs_resend, NR_IRQS);
  23. /*
  24. * Run software resends of IRQ's
  25. */
  26. static void resend_irqs(unsigned long arg)
  27. {
  28. struct irq_desc *desc;
  29. int irq;
  30. while (!bitmap_empty(irqs_resend, NR_IRQS)) {
  31. irq = find_first_bit(irqs_resend, NR_IRQS);
  32. clear_bit(irq, irqs_resend);
  33. desc = irq_desc + irq;
  34. local_irq_disable();
  35. desc->handle_irq(irq, desc);
  36. local_irq_enable();
  37. }
  38. }
  39. /* Tasklet to handle resend: */
  40. static DECLARE_TASKLET(resend_tasklet, resend_irqs, 0);
  41. #endif
  42. /*
  43. * IRQ resend
  44. *
  45. * Is called with interrupts disabled and desc->lock held.
  46. */
  47. void check_irq_resend(struct irq_desc *desc, unsigned int irq)
  48. {
  49. unsigned int status = desc->status;
  50. /*
  51. * Make sure the interrupt is enabled, before resending it:
  52. */
  53. desc->chip->enable(irq);
  54. if ((status & (IRQ_PENDING | IRQ_REPLAY)) == IRQ_PENDING) {
  55. desc->status = (status & ~IRQ_PENDING) | IRQ_REPLAY;
  56. if (!desc->chip || !desc->chip->retrigger ||
  57. !desc->chip->retrigger(irq)) {
  58. #ifdef CONFIG_HARDIRQS_SW_RESEND
  59. /* Set it pending and activate the softirq: */
  60. set_bit(irq, irqs_resend);
  61. tasklet_schedule(&resend_tasklet);
  62. #endif
  63. }
  64. }
  65. }