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 <linux/ftrace.h> 17 #include <linux/uaccess.h> 18 #include <linux/smp.h> 19 #include <asm/io_apic.h> 20 #include <asm/idle.h> 21 #include <asm/apic.h> 22 23 DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat); 24 EXPORT_PER_CPU_SYMBOL(irq_stat); 25 26 DEFINE_PER_CPU(struct pt_regs *, irq_regs); 27 EXPORT_PER_CPU_SYMBOL(irq_regs); 28 29 /* 30 * Probabilistic stack overflow check: 31 * 32 * Only check the stack in process context, because everything else 33 * runs on the big interrupt stacks. Checking reliably is too expensive, 34 * so we just check from interrupts. 35 */ 36 static inline void stack_overflow_check(struct pt_regs *regs) 37 { 38 #ifdef CONFIG_DEBUG_STACKOVERFLOW 39 u64 curbase = (u64)task_stack_page(current); 40 41 WARN_ONCE(regs->sp >= curbase && 42 regs->sp <= curbase + THREAD_SIZE && 43 regs->sp < curbase + sizeof(struct thread_info) + 44 sizeof(struct pt_regs) + 128, 45 46 "do_IRQ: %s near stack overflow (cur:%Lx,sp:%lx)\n", 47 current->comm, curbase, regs->sp); 48 #endif 49 } 50 51 bool handle_irq(unsigned irq, struct pt_regs *regs) 52 { 53 struct irq_desc *desc; 54 55 stack_overflow_check(regs); 56 57 desc = irq_to_desc(irq); 58 if (unlikely(!desc)) 59 return false; 60 61 generic_handle_irq_desc(irq, desc); 62 return true; 63 } 64 65 #ifdef CONFIG_HOTPLUG_CPU 66 /* A cpu has been removed from cpu_online_mask. Reset irq affinities. */ 67 void fixup_irqs(void) 68 { 69 unsigned int irq; 70 static int warned; 71 struct irq_desc *desc; 72 73 for_each_irq_desc(irq, desc) { 74 int break_affinity = 0; 75 int set_affinity = 1; 76 const struct cpumask *affinity; 77 78 if (!desc) 79 continue; 80 if (irq == 2) 81 continue; 82 83 /* interrupt's are disabled at this point */ 84 spin_lock(&desc->lock); 85 86 affinity = desc->affinity; 87 if (!irq_has_action(irq) || 88 cpumask_equal(affinity, cpu_online_mask)) { 89 spin_unlock(&desc->lock); 90 continue; 91 } 92 93 if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) { 94 break_affinity = 1; 95 affinity = cpu_all_mask; 96 } 97 98 if (desc->chip->mask) 99 desc->chip->mask(irq); 100 101 if (desc->chip->set_affinity) 102 desc->chip->set_affinity(irq, affinity); 103 else if (!(warned++)) 104 set_affinity = 0; 105 106 if (desc->chip->unmask) 107 desc->chip->unmask(irq); 108 109 spin_unlock(&desc->lock); 110 111 if (break_affinity && set_affinity) 112 printk("Broke affinity for irq %i\n", irq); 113 else if (!set_affinity) 114 printk("Cannot set affinity for irq %i\n", irq); 115 } 116 117 /* That doesn't seem sufficient. Give it 1ms. */ 118 local_irq_enable(); 119 mdelay(1); 120 local_irq_disable(); 121 } 122 #endif 123 124 extern void call_softirq(void); 125 126 asmlinkage void do_softirq(void) 127 { 128 __u32 pending; 129 unsigned long flags; 130 131 if (in_interrupt()) 132 return; 133 134 local_irq_save(flags); 135 pending = local_softirq_pending(); 136 /* Switch to interrupt stack */ 137 if (pending) { 138 call_softirq(); 139 WARN_ON_ONCE(softirq_count()); 140 } 141 local_irq_restore(flags); 142 } 143