/arch/arm/kernel/irq.c

https://bitbucket.org/thekraven/iscream_thunderc-2.6.35 · C · 206 lines · 136 code · 29 blank · 41 comment · 22 complexity · 8cfc953ca28e461f61804633ca826557 MD5 · raw file

  1. /*
  2. * linux/arch/arm/kernel/irq.c
  3. *
  4. * Copyright (C) 1992 Linus Torvalds
  5. * Modifications for ARM processor Copyright (C) 1995-2000 Russell King.
  6. *
  7. * Support for Dynamic Tick Timer Copyright (C) 2004-2005 Nokia Corporation.
  8. * Dynamic Tick Timer written by Tony Lindgren <tony@atomide.com> and
  9. * Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>.
  10. *
  11. * This program is free software; you can redistribute it and/or modify
  12. * it under the terms of the GNU General Public License version 2 as
  13. * published by the Free Software Foundation.
  14. *
  15. * This file contains the code used by various IRQ handling routines:
  16. * asking for different IRQ's should be done through these routines
  17. * instead of just grabbing them. Thus setups with different IRQ numbers
  18. * shouldn't result in any weird surprises, and installing new handlers
  19. * should be easier.
  20. *
  21. * IRQ's are in fact implemented a bit like signal handlers for the kernel.
  22. * Naturally it's not a 1:1 relation, but there are similarities.
  23. */
  24. #include <linux/kernel_stat.h>
  25. #include <linux/module.h>
  26. #include <linux/signal.h>
  27. #include <linux/ioport.h>
  28. #include <linux/interrupt.h>
  29. #include <linux/irq.h>
  30. #include <linux/random.h>
  31. #include <linux/smp.h>
  32. #include <linux/init.h>
  33. #include <linux/seq_file.h>
  34. #include <linux/errno.h>
  35. #include <linux/list.h>
  36. #include <linux/kallsyms.h>
  37. #include <linux/proc_fs.h>
  38. #include <asm/system.h>
  39. #include <asm/mach/irq.h>
  40. #include <asm/mach/time.h>
  41. #include <asm/perftypes.h>
  42. /*
  43. * No architecture-specific irq_finish function defined in arm/arch/irqs.h.
  44. */
  45. #ifndef irq_finish
  46. #define irq_finish(irq) do { } while (0)
  47. #endif
  48. void (*init_arch_irq)(void) __initdata = NULL;
  49. unsigned long irq_err_count;
  50. int show_interrupts(struct seq_file *p, void *v)
  51. {
  52. int i = *(loff_t *) v, cpu;
  53. struct irqaction * action;
  54. unsigned long flags;
  55. if (i == 0) {
  56. char cpuname[12];
  57. seq_printf(p, " ");
  58. for_each_present_cpu(cpu) {
  59. sprintf(cpuname, "CPU%d", cpu);
  60. seq_printf(p, " %10s", cpuname);
  61. }
  62. seq_putc(p, '\n');
  63. }
  64. if (i < NR_IRQS) {
  65. raw_spin_lock_irqsave(&irq_desc[i].lock, flags);
  66. action = irq_desc[i].action;
  67. if (!action)
  68. goto unlock;
  69. seq_printf(p, "%3d: ", i);
  70. for_each_present_cpu(cpu)
  71. seq_printf(p, "%10u ", kstat_irqs_cpu(i, cpu));
  72. seq_printf(p, " %10s", irq_desc[i].chip->name ? : "-");
  73. seq_printf(p, " %s", action->name);
  74. for (action = action->next; action; action = action->next)
  75. seq_printf(p, ", %s", action->name);
  76. seq_putc(p, '\n');
  77. unlock:
  78. raw_spin_unlock_irqrestore(&irq_desc[i].lock, flags);
  79. } else if (i == NR_IRQS) {
  80. #ifdef CONFIG_FIQ
  81. show_fiq_list(p, v);
  82. #endif
  83. #ifdef CONFIG_SMP
  84. show_ipi_list(p);
  85. show_local_irqs(p);
  86. #endif
  87. seq_printf(p, "Err: %10lu\n", irq_err_count);
  88. }
  89. return 0;
  90. }
  91. /*
  92. * do_IRQ handles all hardware IRQ's. Decoded IRQs should not
  93. * come via this function. Instead, they should provide their
  94. * own 'handler'
  95. */
  96. asmlinkage void __exception asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
  97. {
  98. struct pt_regs *old_regs = set_irq_regs(regs);
  99. perf_mon_interrupt_in();
  100. irq_enter();
  101. /*
  102. * Some hardware gives randomly wrong interrupts. Rather
  103. * than crashing, do something sensible.
  104. */
  105. if (unlikely(irq >= NR_IRQS)) {
  106. if (printk_ratelimit())
  107. printk(KERN_WARNING "Bad IRQ%u\n", irq);
  108. ack_bad_irq(irq);
  109. } else {
  110. generic_handle_irq(irq);
  111. }
  112. /* AT91 specific workaround */
  113. irq_finish(irq);
  114. irq_exit();
  115. set_irq_regs(old_regs);
  116. perf_mon_interrupt_out();
  117. }
  118. void set_irq_flags(unsigned int irq, unsigned int iflags)
  119. {
  120. struct irq_desc *desc;
  121. unsigned long flags;
  122. if (irq >= NR_IRQS) {
  123. printk(KERN_ERR "Trying to set irq flags for IRQ%d\n", irq);
  124. return;
  125. }
  126. desc = irq_desc + irq;
  127. raw_spin_lock_irqsave(&desc->lock, flags);
  128. desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
  129. if (iflags & IRQF_VALID)
  130. desc->status &= ~IRQ_NOREQUEST;
  131. if (iflags & IRQF_PROBE)
  132. desc->status &= ~IRQ_NOPROBE;
  133. if (!(iflags & IRQF_NOAUTOEN))
  134. desc->status &= ~IRQ_NOAUTOEN;
  135. raw_spin_unlock_irqrestore(&desc->lock, flags);
  136. }
  137. void __init init_IRQ(void)
  138. {
  139. int irq;
  140. for (irq = 0; irq < NR_IRQS; irq++)
  141. irq_desc[irq].status |= IRQ_NOREQUEST | IRQ_NOPROBE;
  142. init_arch_irq();
  143. }
  144. #ifdef CONFIG_HOTPLUG_CPU
  145. static void route_irq(struct irq_desc *desc, unsigned int irq, unsigned int cpu)
  146. {
  147. pr_debug("IRQ%u: moving from cpu%u to cpu%u\n", irq, desc->node, cpu);
  148. raw_spin_lock_irq(&desc->lock);
  149. desc->chip->set_affinity(irq, cpumask_of(cpu));
  150. raw_spin_unlock_irq(&desc->lock);
  151. }
  152. /*
  153. * The CPU has been marked offline. Migrate IRQs off this CPU. If
  154. * the affinity settings do not allow other CPUs, force them onto any
  155. * available CPU.
  156. */
  157. void migrate_irqs(void)
  158. {
  159. unsigned int i, cpu = smp_processor_id();
  160. for (i = 0; i < NR_IRQS; i++) {
  161. struct irq_desc *desc = irq_desc + i;
  162. if (desc->node == cpu) {
  163. unsigned int newcpu = cpumask_any_and(desc->affinity,
  164. cpu_online_mask);
  165. if (newcpu >= nr_cpu_ids) {
  166. if (printk_ratelimit())
  167. printk(KERN_INFO "IRQ%u no longer affine to CPU%u\n",
  168. i, cpu);
  169. cpumask_setall(desc->affinity);
  170. newcpu = cpumask_any_and(desc->affinity,
  171. cpu_online_mask);
  172. }
  173. route_irq(desc, i, newcpu);
  174. }
  175. }
  176. }
  177. #endif /* CONFIG_HOTPLUG_CPU */