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
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 <asm/uaccess.h>
17 #include <asm/io_apic.h>
22 * Probabilistic stack overflow check:
24 * Only check the stack in process context, because everything else
25 * runs on the big interrupt stacks. Checking reliably is too expensive,
26 * so we just check from interrupts.
28 static inline void stack_overflow_check(struct pt_regs *regs)
30 #ifdef CONFIG_DEBUG_STACKOVERFLOW
31 u64 curbase = (u64)task_stack_page(current);
33 WARN_ONCE(regs->sp >= curbase &&
34 regs->sp <= curbase + THREAD_SIZE &&
35 regs->sp < curbase + sizeof(struct thread_info) +
36 sizeof(struct pt_regs) + 128,
38 "do_IRQ: %s near stack overflow (cur:%Lx,sp:%lx)\n",
39 current->comm, curbase, regs->sp);
44 * do_IRQ handles all normal device IRQ's (the special
45 * SMP cross-CPU interrupts have their own specific
48 asmlinkage unsigned int do_IRQ(struct pt_regs *regs)
50 struct pt_regs *old_regs = set_irq_regs(regs);
51 struct irq_desc *desc;
53 /* high bit used in ret_from_ code */
54 unsigned vector = ~regs->orig_ax;
59 irq = __get_cpu_var(vector_irq)[vector];
61 stack_overflow_check(regs);
63 desc = irq_to_desc(irq);
65 generic_handle_irq_desc(irq, desc);
70 if (printk_ratelimit())
71 printk(KERN_EMERG "%s: %d.%d No irq handler for vector\n",
72 __func__, smp_processor_id(), vector);
77 set_irq_regs(old_regs);
81 #ifdef CONFIG_HOTPLUG_CPU
82 void fixup_irqs(cpumask_t map)
86 struct irq_desc *desc;
88 for_each_irq_desc(irq, desc) {
90 int break_affinity = 0;
96 /* interrupt's are disabled at this point */
97 spin_lock(&desc->lock);
99 if (!irq_has_action(irq) ||
100 cpus_equal(desc->affinity, map)) {
101 spin_unlock(&desc->lock);
105 cpus_and(mask, desc->affinity, map);
106 if (cpus_empty(mask)) {
111 if (desc->chip->mask)
112 desc->chip->mask(irq);
114 if (desc->chip->set_affinity)
115 desc->chip->set_affinity(irq, mask);
116 else if (!(warned++))
119 if (desc->chip->unmask)
120 desc->chip->unmask(irq);
122 spin_unlock(&desc->lock);
124 if (break_affinity && set_affinity)
125 printk("Broke affinity for irq %i\n", irq);
126 else if (!set_affinity)
127 printk("Cannot set affinity for irq %i\n", irq);
130 /* That doesn't seem sufficient. Give it 1ms. */
137 extern void call_softirq(void);
139 asmlinkage void do_softirq(void)
147 local_irq_save(flags);
148 pending = local_softirq_pending();
149 /* Switch to interrupt stack */
152 WARN_ON_ONCE(softirq_count());
154 local_irq_restore(flags);