Merge commit 'v2.6.28-rc4' into timers/rtc
[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 <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 }