Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee13...
[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, " %14s", irq_desc[i].chip->typename);
78
79                 seq_printf(p, "  %s", action->name);
80                 for (action=action->next; action; action = action->next)
81                         seq_printf(p, ", %s", action->name);
82                 seq_putc(p, '\n');
83 skip:
84                 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
85         } else if (i == NR_IRQS) {
86                 seq_printf(p, "NMI: ");
87                 for_each_online_cpu(j)
88                         seq_printf(p, "%10u ", cpu_pda(j)->__nmi_count);
89                 seq_putc(p, '\n');
90                 seq_printf(p, "LOC: ");
91                 for_each_online_cpu(j)
92                         seq_printf(p, "%10u ", cpu_pda(j)->apic_timer_irqs);
93                 seq_putc(p, '\n');
94                 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
95         }
96         return 0;
97 }
98
99 /*
100  * do_IRQ handles all normal device IRQ's (the special
101  * SMP cross-CPU interrupts have their own specific
102  * handlers).
103  */
104 asmlinkage unsigned int do_IRQ(struct pt_regs *regs)
105 {       
106         /* high bit used in ret_from_ code  */
107         unsigned irq = ~regs->orig_rax;
108
109         if (unlikely(irq >= NR_IRQS)) {
110                 printk(KERN_EMERG "%s: cannot handle IRQ %d\n",
111                                         __FUNCTION__, irq);
112                 BUG();
113         }
114
115         exit_idle();
116         irq_enter();
117 #ifdef CONFIG_DEBUG_STACKOVERFLOW
118         stack_overflow_check(regs);
119 #endif
120         __do_IRQ(irq, regs);
121         irq_exit();
122
123         return 1;
124 }
125
126 #ifdef CONFIG_HOTPLUG_CPU
127 void fixup_irqs(cpumask_t map)
128 {
129         unsigned int irq;
130         static int warned;
131
132         for (irq = 0; irq < NR_IRQS; irq++) {
133                 cpumask_t mask;
134                 if (irq == 2)
135                         continue;
136
137                 cpus_and(mask, irq_desc[irq].affinity, map);
138                 if (any_online_cpu(mask) == NR_CPUS) {
139                         printk("Breaking affinity for irq %i\n", irq);
140                         mask = map;
141                 }
142                 if (irq_desc[irq].chip->set_affinity)
143                         irq_desc[irq].chip->set_affinity(irq, mask);
144                 else if (irq_desc[irq].action && !(warned++))
145                         printk("Cannot set affinity for irq %i\n", irq);
146         }
147
148         /* That doesn't seem sufficient.  Give it 1ms. */
149         local_irq_enable();
150         mdelay(1);
151         local_irq_disable();
152 }
153 #endif
154
155 extern void call_softirq(void);
156
157 asmlinkage void do_softirq(void)
158 {
159         __u32 pending;
160         unsigned long flags;
161
162         if (in_interrupt())
163                 return;
164
165         local_irq_save(flags);
166         pending = local_softirq_pending();
167         /* Switch to interrupt stack */
168         if (pending) {
169                 call_softirq();
170                 WARN_ON_ONCE(softirq_count());
171         }
172         local_irq_restore(flags);
173 }
174 EXPORT_SYMBOL(do_softirq);