1 /* 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> 15 #include <linux/delay.h> 16 #include <asm/uaccess.h> 17 #include <asm/io_apic.h> 18 #include <asm/idle.h> 19 #include <asm/smp.h> 20 21 #ifdef CONFIG_DEBUG_STACKOVERFLOW 22 /* 23 * Probabilistic stack overflow check: 24 * 25 * Only check the stack in process context, because everything else 26 * runs on the big interrupt stacks. Checking reliably is too expensive, 27 * so we just check from interrupts. 28 */ 29 static inline void stack_overflow_check(struct pt_regs *regs) 30 { 31 u64 curbase = (u64)task_stack_page(current); 32 static unsigned long warned = -60*HZ; 33 34 if (regs->sp >= curbase && regs->sp <= curbase + THREAD_SIZE && 35 regs->sp < curbase + sizeof(struct thread_info) + 128 && 36 time_after(jiffies, warned + 60*HZ)) { 37 printk("do_IRQ: %s near stack overflow (cur:%Lx,sp:%lx)\n", 38 current->comm, curbase, regs->sp); 39 show_stack(NULL,NULL); 40 warned = jiffies; 41 } 42 } 43 #endif 44 45 /* 46 * do_IRQ handles all normal device IRQ's (the special 47 * SMP cross-CPU interrupts have their own specific 48 * handlers). 49 */ 50 asmlinkage unsigned int do_IRQ(struct pt_regs *regs) 51 { 52 struct pt_regs *old_regs = set_irq_regs(regs); 53 struct irq_desc *desc; 54 55 /* high bit used in ret_from_ code */ 56 unsigned vector = ~regs->orig_ax; 57 unsigned irq; 58 59 exit_idle(); 60 irq_enter(); 61 irq = __get_cpu_var(vector_irq)[vector]; 62 63 #ifdef CONFIG_DEBUG_STACKOVERFLOW 64 stack_overflow_check(regs); 65 #endif 66 67 desc = irq_to_desc(irq); 68 if (likely(desc)) 69 generic_handle_irq_desc(irq, desc); 70 else { 71 if (!disable_apic) 72 ack_APIC_irq(); 73 74 if (printk_ratelimit()) 75 printk(KERN_EMERG "%s: %d.%d No irq handler for vector\n", 76 __func__, smp_processor_id(), vector); 77 } 78 79 irq_exit(); 80 81 set_irq_regs(old_regs); 82 return 1; 83 } 84 85 #ifdef CONFIG_HOTPLUG_CPU 86 void fixup_irqs(cpumask_t map) 87 { 88 unsigned int irq; 89 static int warned; 90 struct irq_desc *desc; 91 92 for_each_irq_desc(irq, desc) { 93 cpumask_t mask; 94 int break_affinity = 0; 95 int set_affinity = 1; 96 97 if (irq == 2) 98 continue; 99 100 /* interrupt's are disabled at this point */ 101 spin_lock(&desc->lock); 102 103 if (!irq_has_action(irq) || 104 cpus_equal(desc->affinity, map)) { 105 spin_unlock(&desc->lock); 106 continue; 107 } 108 109 cpus_and(mask, desc->affinity, map); 110 if (cpus_empty(mask)) { 111 break_affinity = 1; 112 mask = map; 113 } 114 115 if (desc->chip->mask) 116 desc->chip->mask(irq); 117 118 if (desc->chip->set_affinity) 119 desc->chip->set_affinity(irq, mask); 120 else if (!(warned++)) 121 set_affinity = 0; 122 123 if (desc->chip->unmask) 124 desc->chip->unmask(irq); 125 126 spin_unlock(&desc->lock); 127 128 if (break_affinity && set_affinity) 129 printk("Broke affinity for irq %i\n", irq); 130 else if (!set_affinity) 131 printk("Cannot set affinity for irq %i\n", irq); 132 } 133 134 /* That doesn't seem sufficient. Give it 1ms. */ 135 local_irq_enable(); 136 mdelay(1); 137 local_irq_disable(); 138 } 139 #endif 140 141 extern void call_softirq(void); 142 143 asmlinkage void do_softirq(void) 144 { 145 __u32 pending; 146 unsigned long flags; 147 148 if (in_interrupt()) 149 return; 150 151 local_irq_save(flags); 152 pending = local_softirq_pending(); 153 /* Switch to interrupt stack */ 154 if (pending) { 155 call_softirq(); 156 WARN_ON_ONCE(softirq_count()); 157 } 158 local_irq_restore(flags); 159 } 160