Merge branch 'linus' into core/percpu
[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 <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 /*
52  * do_IRQ handles all normal device IRQ's (the special
53  * SMP cross-CPU interrupts have their own specific
54  * handlers).
55  */
56 asmlinkage unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
57 {
58         struct pt_regs *old_regs = set_irq_regs(regs);
59         struct irq_desc *desc;
60
61         /* high bit used in ret_from_ code  */
62         unsigned vector = ~regs->orig_ax;
63         unsigned irq;
64
65         exit_idle();
66         irq_enter();
67         irq = __get_cpu_var(vector_irq)[vector];
68
69         stack_overflow_check(regs);
70
71         desc = irq_to_desc(irq);
72         if (likely(desc))
73                 generic_handle_irq_desc(irq, desc);
74         else {
75                 if (!disable_apic)
76                         ack_APIC_irq();
77
78                 if (printk_ratelimit())
79                         printk(KERN_EMERG "%s: %d.%d No irq handler for vector\n",
80                                 __func__, smp_processor_id(), vector);
81         }
82
83         irq_exit();
84
85         set_irq_regs(old_regs);
86         return 1;
87 }
88
89 #ifdef CONFIG_HOTPLUG_CPU
90 /* A cpu has been removed from cpu_online_mask.  Reset irq affinities. */
91 void fixup_irqs(void)
92 {
93         unsigned int irq;
94         static int warned;
95         struct irq_desc *desc;
96
97         for_each_irq_desc(irq, desc) {
98                 int break_affinity = 0;
99                 int set_affinity = 1;
100                 const struct cpumask *affinity;
101
102                 if (!desc)
103                         continue;
104                 if (irq == 2)
105                         continue;
106
107                 /* interrupt's are disabled at this point */
108                 spin_lock(&desc->lock);
109
110                 affinity = desc->affinity;
111                 if (!irq_has_action(irq) ||
112                     cpumask_equal(affinity, cpu_online_mask)) {
113                         spin_unlock(&desc->lock);
114                         continue;
115                 }
116
117                 if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
118                         break_affinity = 1;
119                         affinity = cpu_all_mask;
120                 }
121
122                 if (desc->chip->mask)
123                         desc->chip->mask(irq);
124
125                 if (desc->chip->set_affinity)
126                         desc->chip->set_affinity(irq, affinity);
127                 else if (!(warned++))
128                         set_affinity = 0;
129
130                 if (desc->chip->unmask)
131                         desc->chip->unmask(irq);
132
133                 spin_unlock(&desc->lock);
134
135                 if (break_affinity && set_affinity)
136                         printk("Broke affinity for irq %i\n", irq);
137                 else if (!set_affinity)
138                         printk("Cannot set affinity for irq %i\n", irq);
139         }
140
141         /* That doesn't seem sufficient.  Give it 1ms. */
142         local_irq_enable();
143         mdelay(1);
144         local_irq_disable();
145 }
146 #endif
147
148 extern void call_softirq(void);
149
150 asmlinkage void do_softirq(void)
151 {
152         __u32 pending;
153         unsigned long flags;
154
155         if (in_interrupt())
156                 return;
157
158         local_irq_save(flags);
159         pending = local_softirq_pending();
160         /* Switch to interrupt stack */
161         if (pending) {
162                 call_softirq();
163                 WARN_ON_ONCE(softirq_count());
164         }
165         local_irq_restore(flags);
166 }