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 <linux/ftrace.h>
17 #include <linux/uaccess.h>
18 #include <linux/smp.h>
19 #include <asm/io_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 if (user_mode_vm(regs))
44 WARN_ONCE(regs->sp >= curbase &&
45 regs->sp <= curbase + THREAD_SIZE &&
46 regs->sp < curbase + sizeof(struct thread_info) +
47 sizeof(struct pt_regs) + 128,
49 "do_IRQ: %s near stack overflow (cur:%Lx,sp:%lx)\n",
50 current->comm, curbase, regs->sp);
54 bool handle_irq(unsigned irq, struct pt_regs *regs)
56 struct irq_desc *desc;
58 stack_overflow_check(regs);
60 desc = irq_to_desc(irq);
64 generic_handle_irq_desc(irq, desc);
69 extern void call_softirq(void);
71 asmlinkage void do_softirq(void)
79 local_irq_save(flags);
80 pending = local_softirq_pending();
81 /* Switch to interrupt stack */
84 WARN_ON_ONCE(softirq_count());
86 local_irq_restore(flags);