Merge branch 'release' of master.kernel.org:/pub/scm/linux/kernel/git/aegl/linux-2.6
[linux-2.6] / arch / x86_64 / kernel / irq.c
1 /*
2  *      linux/arch/x86_64/kernel/irq.c
3  *
4  *      Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
5  *
6  * This file contains the lowest level x86_64-specific interrupt
7  * entry and irq statistics code. All the remaining irq logic is
8  * done by the generic kernel/irq/ code and in the
9  * x86_64-specific irq controller code. (e.g. i8259.c and
10  * io_apic.c.)
11  */
12
13 #include <linux/kernel_stat.h>
14 #include <linux/interrupt.h>
15 #include <linux/seq_file.h>
16 #include <linux/module.h>
17 #include <linux/delay.h>
18 #include <asm/uaccess.h>
19 #include <asm/io_apic.h>
20 #include <asm/idle.h>
21
22 atomic_t irq_err_count;
23
24 #ifdef CONFIG_DEBUG_STACKOVERFLOW
25 /*
26  * Probabilistic stack overflow check:
27  *
28  * Only check the stack in process context, because everything else
29  * runs on the big interrupt stacks. Checking reliably is too expensive,
30  * so we just check from interrupts.
31  */
32 static inline void stack_overflow_check(struct pt_regs *regs)
33 {
34         u64 curbase = (u64) current->thread_info;
35         static unsigned long warned = -60*HZ;
36
37         if (regs->rsp >= curbase && regs->rsp <= curbase + THREAD_SIZE &&
38             regs->rsp <  curbase + sizeof(struct thread_info) + 128 &&
39             time_after(jiffies, warned + 60*HZ)) {
40                 printk("do_IRQ: %s near stack overflow (cur:%Lx,rsp:%lx)\n",
41                        current->comm, curbase, regs->rsp);
42                 show_stack(NULL,NULL);
43                 warned = jiffies;
44         }
45 }
46 #endif
47
48 /*
49  * Generic, controller-independent functions:
50  */
51
52 int show_interrupts(struct seq_file *p, void *v)
53 {
54         int i = *(loff_t *) v, j;
55         struct irqaction * action;
56         unsigned long flags;
57
58         if (i == 0) {
59                 seq_printf(p, "           ");
60                 for_each_online_cpu(j)
61                         seq_printf(p, "CPU%-8d",j);
62                 seq_putc(p, '\n');
63         }
64
65         if (i < NR_IRQS) {
66                 spin_lock_irqsave(&irq_desc[i].lock, flags);
67                 action = irq_desc[i].action;
68                 if (!action) 
69                         goto skip;
70                 seq_printf(p, "%3d: ",i);
71 #ifndef CONFIG_SMP
72                 seq_printf(p, "%10u ", kstat_irqs(i));
73 #else
74                 for_each_online_cpu(j)
75                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
76 #endif
77                 seq_printf(p, " %8s", irq_desc[i].chip->name);
78                 seq_printf(p, "-%-8s", irq_desc[i].name);
79
80                 seq_printf(p, "  %s", action->name);
81                 for (action=action->next; action; action = action->next)
82                         seq_printf(p, ", %s", action->name);
83                 seq_putc(p, '\n');
84 skip:
85                 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
86         } else if (i == NR_IRQS) {
87                 seq_printf(p, "NMI: ");
88                 for_each_online_cpu(j)
89                         seq_printf(p, "%10u ", cpu_pda(j)->__nmi_count);
90                 seq_putc(p, '\n');
91                 seq_printf(p, "LOC: ");
92                 for_each_online_cpu(j)
93                         seq_printf(p, "%10u ", cpu_pda(j)->apic_timer_irqs);
94                 seq_putc(p, '\n');
95                 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
96         }
97         return 0;
98 }
99
100 /*
101  * do_IRQ handles all normal device IRQ's (the special
102  * SMP cross-CPU interrupts have their own specific
103  * handlers).
104  */
105 asmlinkage unsigned int do_IRQ(struct pt_regs *regs)
106 {
107         struct pt_regs *old_regs = set_irq_regs(regs);
108
109         /* high bit used in ret_from_ code  */
110         unsigned vector = ~regs->orig_rax;
111         unsigned irq;
112
113         exit_idle();
114         irq_enter();
115         irq = __get_cpu_var(vector_irq)[vector];
116
117 #ifdef CONFIG_DEBUG_STACKOVERFLOW
118         stack_overflow_check(regs);
119 #endif
120
121         if (likely(irq < NR_IRQS))
122                 generic_handle_irq(irq);
123         else if (printk_ratelimit())
124                 printk(KERN_EMERG "%s: %d.%d No irq handler for vector\n",
125                         __func__, smp_processor_id(), vector);
126
127         irq_exit();
128
129         set_irq_regs(old_regs);
130         return 1;
131 }
132
133 #ifdef CONFIG_HOTPLUG_CPU
134 void fixup_irqs(cpumask_t map)
135 {
136         unsigned int irq;
137         static int warned;
138
139         for (irq = 0; irq < NR_IRQS; irq++) {
140                 cpumask_t mask;
141                 if (irq == 2)
142                         continue;
143
144                 cpus_and(mask, irq_desc[irq].affinity, map);
145                 if (any_online_cpu(mask) == NR_CPUS) {
146                         printk("Breaking affinity for irq %i\n", irq);
147                         mask = map;
148                 }
149                 if (irq_desc[irq].chip->set_affinity)
150                         irq_desc[irq].chip->set_affinity(irq, mask);
151                 else if (irq_desc[irq].action && !(warned++))
152                         printk("Cannot set affinity for irq %i\n", irq);
153         }
154
155         /* That doesn't seem sufficient.  Give it 1ms. */
156         local_irq_enable();
157         mdelay(1);
158         local_irq_disable();
159 }
160 #endif
161
162 extern void call_softirq(void);
163
164 asmlinkage void do_softirq(void)
165 {
166         __u32 pending;
167         unsigned long flags;
168
169         if (in_interrupt())
170                 return;
171
172         local_irq_save(flags);
173         pending = local_softirq_pending();
174         /* Switch to interrupt stack */
175         if (pending) {
176                 call_softirq();
177                 WARN_ON_ONCE(softirq_count());
178         }
179         local_irq_restore(flags);
180 }
181 EXPORT_SYMBOL(do_softirq);