1 /* 2 * This file is subject to the terms and conditions of the GNU General Public 3 * License. See the file "COPYING" in the main directory of this archive 4 * for more details. 5 * 6 * Code to handle x86 style IRQs plus some generic interrupt stuff. 7 * 8 * Copyright (C) 1992 Linus Torvalds 9 * Copyright (C) 1994 - 2000 Ralf Baechle 10 */ 11 #include <linux/kernel.h> 12 #include <linux/delay.h> 13 #include <linux/init.h> 14 #include <linux/interrupt.h> 15 #include <linux/kernel_stat.h> 16 #include <linux/proc_fs.h> 17 #include <linux/mm.h> 18 #include <linux/random.h> 19 #include <linux/sched.h> 20 #include <linux/seq_file.h> 21 #include <linux/kallsyms.h> 22 #include <linux/kgdb.h> 23 #include <linux/ftrace.h> 24 25 #include <linux/atomic.h> 26 #include <linux/uaccess.h> 27 28 void *irq_stack[NR_CPUS]; 29 30 /* 31 * 'what should we do if we get a hw irq event on an illegal vector'. 32 * each architecture has to answer this themselves. 33 */ 34 void ack_bad_irq(unsigned int irq) 35 { 36 printk("unexpected IRQ # %d\n", irq); 37 } 38 39 atomic_t irq_err_count; 40 41 int arch_show_interrupts(struct seq_file *p, int prec) 42 { 43 seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count)); 44 return 0; 45 } 46 47 asmlinkage void spurious_interrupt(void) 48 { 49 atomic_inc(&irq_err_count); 50 } 51 52 void __init init_IRQ(void) 53 { 54 int i; 55 unsigned int order = get_order(IRQ_STACK_SIZE); 56 57 for (i = 0; i < NR_IRQS; i++) 58 irq_set_noprobe(i); 59 60 if (cpu_has_veic) 61 clear_c0_status(ST0_IM); 62 63 arch_init_irq(); 64 65 for_each_possible_cpu(i) { 66 void *s = (void *)__get_free_pages(GFP_KERNEL, order); 67 68 irq_stack[i] = s; 69 pr_debug("CPU%d IRQ stack at 0x%p - 0x%p\n", i, 70 irq_stack[i], irq_stack[i] + IRQ_STACK_SIZE); 71 } 72 } 73 74 #ifdef CONFIG_DEBUG_STACKOVERFLOW 75 static inline void check_stack_overflow(void) 76 { 77 unsigned long sp; 78 79 __asm__ __volatile__("move %0, $sp" : "=r" (sp)); 80 sp &= THREAD_MASK; 81 82 /* 83 * Check for stack overflow: is there less than STACK_WARN free? 84 * STACK_WARN is defined as 1/8 of THREAD_SIZE by default. 85 */ 86 if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) { 87 printk("do_IRQ: stack overflow: %ld\n", 88 sp - sizeof(struct thread_info)); 89 dump_stack(); 90 } 91 } 92 #else 93 static inline void check_stack_overflow(void) {} 94 #endif 95 96 97 /* 98 * do_IRQ handles all normal device IRQ's (the special 99 * SMP cross-CPU interrupts have their own specific 100 * handlers). 101 */ 102 void __irq_entry do_IRQ(unsigned int irq) 103 { 104 irq_enter(); 105 check_stack_overflow(); 106 generic_handle_irq(irq); 107 irq_exit(); 108 } 109 110