| /* |
| * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar |
| * |
| * This file contains the lowest level x86_64-specific interrupt |
| * entry and irq statistics code. All the remaining irq logic is |
| * done by the generic kernel/irq/ code and in the |
| * x86_64-specific irq controller code. (e.g. i8259.c and |
| * io_apic.c.) |
| */ |
| |
| #include <linux/kernel_stat.h> |
| #include <linux/interrupt.h> |
| #include <linux/seq_file.h> |
| #include <linux/module.h> |
| #include <linux/delay.h> |
| #include <linux/ftrace.h> |
| #include <linux/uaccess.h> |
| #include <linux/smp.h> |
| #include <asm/io_apic.h> |
| #include <asm/idle.h> |
| #include <asm/apic.h> |
| |
| DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat); |
| EXPORT_PER_CPU_SYMBOL(irq_stat); |
| |
| DEFINE_PER_CPU(struct pt_regs *, irq_regs); |
| EXPORT_PER_CPU_SYMBOL(irq_regs); |
| |
| /* |
| * Probabilistic stack overflow check: |
| * |
| * Only check the stack in process context, because everything else |
| * runs on the big interrupt stacks. Checking reliably is too expensive, |
| * so we just check from interrupts. |
| */ |
| static inline void stack_overflow_check(struct pt_regs *regs) |
| { |
| #ifdef CONFIG_DEBUG_STACKOVERFLOW |
| u64 curbase = (u64)task_stack_page(current); |
| |
| if (user_mode_vm(regs)) |
| return; |
| |
| WARN_ONCE(regs->sp >= curbase && |
| regs->sp <= curbase + THREAD_SIZE && |
| regs->sp < curbase + sizeof(struct thread_info) + |
| sizeof(struct pt_regs) + 128, |
| |
| "do_IRQ: %s near stack overflow (cur:%Lx,sp:%lx)\n", |
| current->comm, curbase, regs->sp); |
| #endif |
| } |
| |
| bool handle_irq(unsigned irq, struct pt_regs *regs) |
| { |
| struct irq_desc *desc; |
| |
| stack_overflow_check(regs); |
| |
| desc = irq_to_desc(irq); |
| if (unlikely(!desc)) |
| return false; |
| |
| generic_handle_irq_desc(irq, desc); |
| return true; |
| } |
| |
| |
| extern void call_softirq(void); |
| |
| asmlinkage void do_softirq(void) |
| { |
| __u32 pending; |
| unsigned long flags; |
| |
| if (in_interrupt()) |
| return; |
| |
| local_irq_save(flags); |
| pending = local_softirq_pending(); |
| /* Switch to interrupt stack */ |
| if (pending) { |
| call_softirq(); |
| WARN_ON_ONCE(softirq_count()); |
| } |
| local_irq_restore(flags); |
| } |