Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
[linux-2.6.git] / arch / x86 / kernel / irq_64.c
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 <asm/uaccess.h>
18 #include <asm/io_apic.h>
19 #include <asm/idle.h>
20 #include <asm/smp.h>
21
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 #ifdef CONFIG_DEBUG_STACKOVERFLOW
32         u64 curbase = (u64)task_stack_page(current);
33
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,
38
39                   "do_IRQ: %s near stack overflow (cur:%Lx,sp:%lx)\n",
40                         current->comm, curbase, regs->sp);
41 #endif
42 }
43
44 /*
45  * do_IRQ handles all normal device IRQ's (the special
46  * SMP cross-CPU interrupts have their own specific
47  * handlers).
48  */
49 asmlinkage unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
50 {
51         struct pt_regs *old_regs = set_irq_regs(regs);
52         struct irq_desc *desc;
53
54         /* high bit used in ret_from_ code  */
55         unsigned vector = ~regs->orig_ax;
56         unsigned irq;
57
58         exit_idle();
59         irq_enter();
60         irq = __get_cpu_var(vector_irq)[vector];
61
62         stack_overflow_check(regs);
63
64         desc = irq_to_desc(irq);
65         if (likely(desc))
66                 generic_handle_irq_desc(irq, desc);
67         else {
68                 if (!disable_apic)
69                         ack_APIC_irq();
70
71                 if (printk_ratelimit())
72                         printk(KERN_EMERG "%s: %d.%d No irq handler for vector\n",
73                                 __func__, smp_processor_id(), vector);
74         }
75
76         irq_exit();
77
78         set_irq_regs(old_regs);
79         return 1;
80 }
81
82 #ifdef CONFIG_HOTPLUG_CPU
83 void fixup_irqs(cpumask_t map)
84 {
85         unsigned int irq;
86         static int warned;
87         struct irq_desc *desc;
88
89         for_each_irq_desc(irq, desc) {
90                 cpumask_t mask;
91                 int break_affinity = 0;
92                 int set_affinity = 1;
93
94                 if (irq == 2)
95                         continue;
96
97                 /* interrupt's are disabled at this point */
98                 spin_lock(&desc->lock);
99
100                 if (!irq_has_action(irq) ||
101                     cpus_equal(desc->affinity, map)) {
102                         spin_unlock(&desc->lock);
103                         continue;
104                 }
105
106                 cpus_and(mask, desc->affinity, map);
107                 if (cpus_empty(mask)) {
108                         break_affinity = 1;
109                         mask = map;
110                 }
111
112                 if (desc->chip->mask)
113                         desc->chip->mask(irq);
114
115                 if (desc->chip->set_affinity)
116                         desc->chip->set_affinity(irq, &mask);
117                 else if (!(warned++))
118                         set_affinity = 0;
119
120                 if (desc->chip->unmask)
121                         desc->chip->unmask(irq);
122
123                 spin_unlock(&desc->lock);
124
125                 if (break_affinity && set_affinity)
126                         printk("Broke affinity for irq %i\n", irq);
127                 else if (!set_affinity)
128                         printk("Cannot set affinity for irq %i\n", irq);
129         }
130
131         /* That doesn't seem sufficient.  Give it 1ms. */
132         local_irq_enable();
133         mdelay(1);
134         local_irq_disable();
135 }
136 #endif
137
138 extern void call_softirq(void);
139
140 asmlinkage void do_softirq(void)
141 {
142         __u32 pending;
143         unsigned long flags;
144
145         if (in_interrupt())
146                 return;
147
148         local_irq_save(flags);
149         pending = local_softirq_pending();
150         /* Switch to interrupt stack */
151         if (pending) {
152                 call_softirq();
153                 WARN_ON_ONCE(softirq_count());
154         }
155         local_irq_restore(flags);
156 }