Merge branch 'topic/asoc' into for-linus
[linux-2.6] / 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 /* A cpu has been removed from cpu_online_mask.  Reset irq affinities. */
84 void fixup_irqs(void)
85 {
86         unsigned int irq;
87         static int warned;
88         struct irq_desc *desc;
89
90         for_each_irq_desc(irq, desc) {
91                 int break_affinity = 0;
92                 int set_affinity = 1;
93                 const struct cpumask *affinity;
94
95                 if (!desc)
96                         continue;
97                 if (irq == 2)
98                         continue;
99
100                 /* interrupt's are disabled at this point */
101                 spin_lock(&desc->lock);
102
103                 affinity = &desc->affinity;
104                 if (!irq_has_action(irq) ||
105                     cpumask_equal(affinity, cpu_online_mask)) {
106                         spin_unlock(&desc->lock);
107                         continue;
108                 }
109
110                 if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
111                         break_affinity = 1;
112                         affinity = cpu_all_mask;
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, affinity);
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 }