Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
[linux-2.6/mini2440.git] / arch / x86 / kernel / irq_64.c
blob8cbd069e5b41f6412aad93b0dea2409bd5934448
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 <asm/uaccess.h>
18 #include <asm/io_apic.h>
19 #include <asm/idle.h>
20 #include <asm/smp.h>
23 * Probabilistic stack overflow check:
25 * Only check the stack in process context, because everything else
26 * runs on the big interrupt stacks. Checking reliably is too expensive,
27 * so we just check from interrupts.
29 static inline void stack_overflow_check(struct pt_regs *regs)
31 #ifdef CONFIG_DEBUG_STACKOVERFLOW
32 u64 curbase = (u64)task_stack_page(current);
34 WARN_ONCE(regs->sp >= curbase &&
35 regs->sp <= curbase + THREAD_SIZE &&
36 regs->sp < curbase + sizeof(struct thread_info) +
37 sizeof(struct pt_regs) + 128,
39 "do_IRQ: %s near stack overflow (cur:%Lx,sp:%lx)\n",
40 current->comm, curbase, regs->sp);
41 #endif
45 * do_IRQ handles all normal device IRQ's (the special
46 * SMP cross-CPU interrupts have their own specific
47 * handlers).
49 asmlinkage unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
51 struct pt_regs *old_regs = set_irq_regs(regs);
52 struct irq_desc *desc;
54 /* high bit used in ret_from_ code */
55 unsigned vector = ~regs->orig_ax;
56 unsigned irq;
58 exit_idle();
59 irq_enter();
60 irq = __get_cpu_var(vector_irq)[vector];
62 stack_overflow_check(regs);
64 desc = irq_to_desc(irq);
65 if (likely(desc))
66 generic_handle_irq_desc(irq, desc);
67 else {
68 if (!disable_apic)
69 ack_APIC_irq();
71 if (printk_ratelimit())
72 printk(KERN_EMERG "%s: %d.%d No irq handler for vector\n",
73 __func__, smp_processor_id(), vector);
76 irq_exit();
78 set_irq_regs(old_regs);
79 return 1;
82 #ifdef CONFIG_HOTPLUG_CPU
83 void fixup_irqs(cpumask_t map)
85 unsigned int irq;
86 static int warned;
87 struct irq_desc *desc;
89 for_each_irq_desc(irq, desc) {
90 cpumask_t mask;
91 int break_affinity = 0;
92 int set_affinity = 1;
94 if (irq == 2)
95 continue;
97 /* interrupt's are disabled at this point */
98 spin_lock(&desc->lock);
100 if (!irq_has_action(irq) ||
101 cpus_equal(desc->affinity, map)) {
102 spin_unlock(&desc->lock);
103 continue;
106 cpus_and(mask, desc->affinity, map);
107 if (cpus_empty(mask)) {
108 break_affinity = 1;
109 mask = map;
112 if (desc->chip->mask)
113 desc->chip->mask(irq);
115 if (desc->chip->set_affinity)
116 desc->chip->set_affinity(irq, &mask);
117 else if (!(warned++))
118 set_affinity = 0;
120 if (desc->chip->unmask)
121 desc->chip->unmask(irq);
123 spin_unlock(&desc->lock);
125 if (break_affinity && set_affinity)
126 printk("Broke affinity for irq %i\n", irq);
127 else if (!set_affinity)
128 printk("Cannot set affinity for irq %i\n", irq);
131 /* That doesn't seem sufficient. Give it 1ms. */
132 local_irq_enable();
133 mdelay(1);
134 local_irq_disable();
136 #endif
138 extern void call_softirq(void);
140 asmlinkage void do_softirq(void)
142 __u32 pending;
143 unsigned long flags;
145 if (in_interrupt())
146 return;
148 local_irq_save(flags);
149 pending = local_softirq_pending();
150 /* Switch to interrupt stack */
151 if (pending) {
152 call_softirq();
153 WARN_ON_ONCE(softirq_count());
155 local_irq_restore(flags);