acpi_pad: build only on X86
[linux-2.6/linux-acpi-2.6.git] / arch / x86 / kernel / irq_64.c
blob977d8b43a0ddc06597ff46942730e6759d2ca035
1 /*
2 * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
4 * This file contains the lowest level x86_64-specific interrupt
5 * entry and irq statistics code. All the remaining irq logic is
6 * done by the generic kernel/irq/ code and in the
7 * x86_64-specific irq controller code. (e.g. i8259.c and
8 * io_apic.c.)
9 */
11 #include <linux/kernel_stat.h>
12 #include <linux/interrupt.h>
13 #include <linux/seq_file.h>
14 #include <linux/module.h>
15 #include <linux/delay.h>
16 #include <linux/ftrace.h>
17 #include <linux/uaccess.h>
18 #include <linux/smp.h>
19 #include <asm/io_apic.h>
20 #include <asm/idle.h>
21 #include <asm/apic.h>
23 DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
24 EXPORT_PER_CPU_SYMBOL(irq_stat);
26 DEFINE_PER_CPU(struct pt_regs *, irq_regs);
27 EXPORT_PER_CPU_SYMBOL(irq_regs);
30 * Probabilistic stack overflow check:
32 * Only check the stack in process context, because everything else
33 * runs on the big interrupt stacks. Checking reliably is too expensive,
34 * so we just check from interrupts.
36 static inline void stack_overflow_check(struct pt_regs *regs)
38 #ifdef CONFIG_DEBUG_STACKOVERFLOW
39 u64 curbase = (u64)task_stack_page(current);
41 WARN_ONCE(regs->sp >= curbase &&
42 regs->sp <= curbase + THREAD_SIZE &&
43 regs->sp < curbase + sizeof(struct thread_info) +
44 sizeof(struct pt_regs) + 128,
46 "do_IRQ: %s near stack overflow (cur:%Lx,sp:%lx)\n",
47 current->comm, curbase, regs->sp);
48 #endif
51 bool handle_irq(unsigned irq, struct pt_regs *regs)
53 struct irq_desc *desc;
55 stack_overflow_check(regs);
57 desc = irq_to_desc(irq);
58 if (unlikely(!desc))
59 return false;
61 generic_handle_irq_desc(irq, desc);
62 return true;
65 #ifdef CONFIG_HOTPLUG_CPU
66 /* A cpu has been removed from cpu_online_mask. Reset irq affinities. */
67 void fixup_irqs(void)
69 unsigned int irq;
70 static int warned;
71 struct irq_desc *desc;
73 for_each_irq_desc(irq, desc) {
74 int break_affinity = 0;
75 int set_affinity = 1;
76 const struct cpumask *affinity;
78 if (!desc)
79 continue;
80 if (irq == 2)
81 continue;
83 /* interrupt's are disabled at this point */
84 spin_lock(&desc->lock);
86 affinity = desc->affinity;
87 if (!irq_has_action(irq) ||
88 cpumask_equal(affinity, cpu_online_mask)) {
89 spin_unlock(&desc->lock);
90 continue;
93 if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
94 break_affinity = 1;
95 affinity = cpu_all_mask;
98 if (desc->chip->mask)
99 desc->chip->mask(irq);
101 if (desc->chip->set_affinity)
102 desc->chip->set_affinity(irq, affinity);
103 else if (!(warned++))
104 set_affinity = 0;
106 if (desc->chip->unmask)
107 desc->chip->unmask(irq);
109 spin_unlock(&desc->lock);
111 if (break_affinity && set_affinity)
112 printk("Broke affinity for irq %i\n", irq);
113 else if (!set_affinity)
114 printk("Cannot set affinity for irq %i\n", irq);
117 /* That doesn't seem sufficient. Give it 1ms. */
118 local_irq_enable();
119 mdelay(1);
120 local_irq_disable();
122 #endif
124 extern void call_softirq(void);
126 asmlinkage void do_softirq(void)
128 __u32 pending;
129 unsigned long flags;
131 if (in_interrupt())
132 return;
134 local_irq_save(flags);
135 pending = local_softirq_pending();
136 /* Switch to interrupt stack */
137 if (pending) {
138 call_softirq();
139 WARN_ON_ONCE(softirq_count());
141 local_irq_restore(flags);