| /* |
| * This file is subject to the terms and conditions of the GNU General Public |
| * License. See the file "COPYING" in the main directory of this archive |
| * for more details. |
| * |
| * Code to handle x86 style IRQs plus some generic interrupt stuff. |
| * |
| * Copyright (C) 1992 Linus Torvalds |
| * Copyright (C) 1994 - 2000 Ralf Baechle |
| */ |
| #include <linux/kernel.h> |
| #include <linux/delay.h> |
| #include <linux/init.h> |
| #include <linux/interrupt.h> |
| #include <linux/kernel_stat.h> |
| #include <linux/proc_fs.h> |
| #include <linux/mm.h> |
| #include <linux/random.h> |
| #include <linux/sched.h> |
| #include <linux/seq_file.h> |
| #include <linux/kallsyms.h> |
| #include <linux/kgdb.h> |
| #include <linux/ftrace.h> |
| |
| #include <linux/atomic.h> |
| #include <asm/uaccess.h> |
| |
| #ifdef CONFIG_KGDB |
| int kgdb_early_setup; |
| #endif |
| |
| static DECLARE_BITMAP(irq_map, NR_IRQS); |
| |
| int allocate_irqno(void) |
| { |
| int irq; |
| |
| again: |
| irq = find_first_zero_bit(irq_map, NR_IRQS); |
| |
| if (irq >= NR_IRQS) |
| return -ENOSPC; |
| |
| if (test_and_set_bit(irq, irq_map)) |
| goto again; |
| |
| return irq; |
| } |
| |
| /* |
| * Allocate the 16 legacy interrupts for i8259 devices. This happens early |
| * in the kernel initialization so treating allocation failure as BUG() is |
| * ok. |
| */ |
| void __init alloc_legacy_irqno(void) |
| { |
| int i; |
| |
| for (i = 0; i <= 16; i++) |
| BUG_ON(test_and_set_bit(i, irq_map)); |
| } |
| |
| void free_irqno(unsigned int irq) |
| { |
| smp_mb__before_atomic(); |
| clear_bit(irq, irq_map); |
| smp_mb__after_atomic(); |
| } |
| |
| /* |
| * 'what should we do if we get a hw irq event on an illegal vector'. |
| * each architecture has to answer this themselves. |
| */ |
| void ack_bad_irq(unsigned int irq) |
| { |
| printk("unexpected IRQ # %d\n", irq); |
| } |
| |
| atomic_t irq_err_count; |
| |
| int arch_show_interrupts(struct seq_file *p, int prec) |
| { |
| seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count)); |
| return 0; |
| } |
| |
| asmlinkage void spurious_interrupt(void) |
| { |
| atomic_inc(&irq_err_count); |
| } |
| |
| void __init init_IRQ(void) |
| { |
| int i; |
| |
| #ifdef CONFIG_KGDB |
| if (kgdb_early_setup) |
| return; |
| #endif |
| |
| for (i = 0; i < NR_IRQS; i++) |
| irq_set_noprobe(i); |
| |
| arch_init_irq(); |
| |
| #ifdef CONFIG_KGDB |
| if (!kgdb_early_setup) |
| kgdb_early_setup = 1; |
| #endif |
| } |
| |
| #ifdef CONFIG_DEBUG_STACKOVERFLOW |
| static inline void check_stack_overflow(void) |
| { |
| unsigned long sp; |
| |
| __asm__ __volatile__("move %0, $sp" : "=r" (sp)); |
| sp &= THREAD_MASK; |
| |
| /* |
| * Check for stack overflow: is there less than STACK_WARN free? |
| * STACK_WARN is defined as 1/8 of THREAD_SIZE by default. |
| */ |
| if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) { |
| printk("do_IRQ: stack overflow: %ld\n", |
| sp - sizeof(struct thread_info)); |
| dump_stack(); |
| } |
| } |
| #else |
| static inline void check_stack_overflow(void) {} |
| #endif |
| |
| |
| /* |
| * do_IRQ handles all normal device IRQ's (the special |
| * SMP cross-CPU interrupts have their own specific |
| * handlers). |
| */ |
| void __irq_entry do_IRQ(unsigned int irq) |
| { |
| irq_enter(); |
| check_stack_overflow(); |
| generic_handle_irq(irq); |
| irq_exit(); |
| } |
| |