/* * 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 unsigned long irq_map[NR_IRQS / BITS_PER_LONG]; 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) { smtc_im_ack_irq(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 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(); if (!smtc_handle_on_other_cpu(irq)) generic_handle_irq(irq); irq_exit(); } #ifdef CONFIG_MIPS_MT_SMTC_IRQAFF /* * To avoid inefficient and in some cases pathological re-checking of * IRQ affinity, we have this variant that skips the affinity check. */ void __irq_entry do_IRQ_no_affinity(unsigned int irq) { irq_enter(); smtc_im_backstop(irq); generic_handle_irq(irq); irq_exit(); } #endif /* CONFIG_MIPS_MT_SMTC_IRQAFF */