2 * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
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
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 <asm/uaccess.h>
18 #include <asm/io_apic.h>
23 * Probabilistic stack overflow check:
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.
29 static inline void stack_overflow_check(struct pt_regs
*regs
)
31 #ifdef CONFIG_DEBUG_STACKOVERFLOW
32 u64 curbase
= (u64
)task_stack_page(current
);
34 WARN_ONCE(regs
->sp
>= curbase
&&
35 regs
->sp
<= curbase
+ THREAD_SIZE
&&
36 regs
->sp
< curbase
+ sizeof(struct thread_info
) +
37 sizeof(struct pt_regs
) + 128,
39 "do_IRQ: %s near stack overflow (cur:%Lx,sp:%lx)\n",
40 current
->comm
, curbase
, regs
->sp
);
45 * do_IRQ handles all normal device IRQ's (the special
46 * SMP cross-CPU interrupts have their own specific
49 asmlinkage
unsigned int __irq_entry
do_IRQ(struct pt_regs
*regs
)
51 struct pt_regs
*old_regs
= set_irq_regs(regs
);
52 struct irq_desc
*desc
;
54 /* high bit used in ret_from_ code */
55 unsigned vector
= ~regs
->orig_ax
;
60 irq
= __get_cpu_var(vector_irq
)[vector
];
62 stack_overflow_check(regs
);
64 desc
= irq_to_desc(irq
);
66 generic_handle_irq_desc(irq
, desc
);
71 if (printk_ratelimit())
72 printk(KERN_EMERG
"%s: %d.%d No irq handler for vector\n",
73 __func__
, smp_processor_id(), vector
);
78 set_irq_regs(old_regs
);
82 #ifdef CONFIG_HOTPLUG_CPU
83 /* A cpu has been removed from cpu_online_mask. Reset irq affinities. */
88 struct irq_desc
*desc
;
90 for_each_irq_desc(irq
, desc
) {
91 int break_affinity
= 0;
93 const struct cpumask
*affinity
;
100 /* interrupt's are disabled at this point */
101 spin_lock(&desc
->lock
);
103 affinity
= &desc
->affinity
;
104 if (!irq_has_action(irq
) ||
105 cpumask_equal(affinity
, cpu_online_mask
)) {
106 spin_unlock(&desc
->lock
);
110 if (cpumask_any_and(affinity
, cpu_online_mask
) >= nr_cpu_ids
) {
112 affinity
= cpu_all_mask
;
115 if (desc
->chip
->mask
)
116 desc
->chip
->mask(irq
);
118 if (desc
->chip
->set_affinity
)
119 desc
->chip
->set_affinity(irq
, affinity
);
120 else if (!(warned
++))
123 if (desc
->chip
->unmask
)
124 desc
->chip
->unmask(irq
);
126 spin_unlock(&desc
->lock
);
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
);
134 /* That doesn't seem sufficient. Give it 1ms. */
141 extern void call_softirq(void);
143 asmlinkage
void do_softirq(void)
151 local_irq_save(flags
);
152 pending
= local_softirq_pending();
153 /* Switch to interrupt stack */
156 WARN_ON_ONCE(softirq_count());
158 local_irq_restore(flags
);
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