projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da177e4 | 1 | /* |
| 1da177e4 LT |
2 | * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar |
| 3 | * | |
| 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 | */ | |
| 10 | ||
| 11 | #include <linux/kernel_stat.h> | |
| 12 | #include <linux/interrupt.h> | |
| 13 | #include <linux/seq_file.h> | |
| 14 | #include <linux/module.h> | |
| 76e4f660 | 15 | #include <linux/delay.h> |
| bcbc4f20 | 16 | #include <linux/ftrace.h> |
| 5f66b2a0 JSR |
17 | #include <linux/uaccess.h> |
| 18 | #include <linux/smp.h> | |
| 1da177e4 | 19 | #include <asm/io_apic.h> |
| 95833c83 | 20 | #include <asm/idle.h> |
| 3819cd48 | 21 | #include <asm/apic.h> |
| 1da177e4 | 22 | |
| 1b437c8c BG |
23 | DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat); |
| 24 | EXPORT_PER_CPU_SYMBOL(irq_stat); | |
| 25 | ||
| d650a514 BG |
26 | DEFINE_PER_CPU(struct pt_regs *, irq_regs); |
| 27 | EXPORT_PER_CPU_SYMBOL(irq_regs); | |
| 28 | ||
| 4961f10e ES |
29 | /* |
| 30 | * Probabilistic stack overflow check: | |
| 31 | * | |
| 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. | |
| 35 | */ | |
| 36 | static inline void stack_overflow_check(struct pt_regs *regs) | |
| 37 | { | |
| f377fa12 | 38 | #ifdef CONFIG_DEBUG_STACKOVERFLOW |
| c9f4f06d | 39 | u64 curbase = (u64)task_stack_page(current); |
| f377fa12 | 40 | |
| 69682b62 MH |
41 | if (user_mode_vm(regs)) |
| 42 | return; | |
| 43 | ||
| f377fa12 IM |
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, | |
| 48 | ||
| 49 | "do_IRQ: %s near stack overflow (cur:%Lx,sp:%lx)\n", | |
| 50 | current->comm, curbase, regs->sp); | |
| 4961f10e | 51 | #endif |
| f377fa12 | 52 | } |
| 4961f10e | 53 | |
| 9b2b76a3 JF |
54 | bool handle_irq(unsigned irq, struct pt_regs *regs) |
| 55 | { | |
| 56 | struct irq_desc *desc; | |
| 57 | ||
| 58 | stack_overflow_check(regs); | |
| 59 | ||
| 60 | desc = irq_to_desc(irq); | |
| 61 | if (unlikely(!desc)) | |
| 62 | return false; | |
| 63 | ||
| 64 | generic_handle_irq_desc(irq, desc); | |
| 65 | return true; | |
| 66 | } | |
| 67 | ||
| ed6b676c AK |
68 | |
| 69 | extern void call_softirq(void); | |
| 70 | ||
| 71 | asmlinkage void do_softirq(void) | |
| 72 | { | |
| 5f66b2a0 JSR |
73 | __u32 pending; |
| 74 | unsigned long flags; | |
| ed6b676c | 75 | |
| 5f66b2a0 JSR |
76 | if (in_interrupt()) |
| 77 | return; | |
| ed6b676c | 78 | |
| 5f66b2a0 JSR |
79 | local_irq_save(flags); |
| 80 | pending = local_softirq_pending(); | |
| 81 | /* Switch to interrupt stack */ | |
| 82 | if (pending) { | |
| ed6b676c | 83 | call_softirq(); |
| 2601e64d IM |
84 | WARN_ON_ONCE(softirq_count()); |
| 85 | } | |
| 5f66b2a0 | 86 | local_irq_restore(flags); |
| ed6b676c | 87 | } |