[PATCH] alpha show_interrups() trashes argument
[linux-2.6.git] / arch / alpha / kernel / irq.c
1 /*
2  *      linux/arch/alpha/kernel/irq.c
3  *
4  *      Copyright (C) 1995 Linus Torvalds
5  *
6  * This file contains the code used by various IRQ handling routines:
7  * asking for different IRQ's should be done through these routines
8  * instead of just grabbing them. Thus setups with different IRQ numbers
9  * shouldn't result in any weird surprises, and installing new handlers
10  * should be easier.
11  */
12
13 #include <linux/config.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/errno.h>
17 #include <linux/kernel_stat.h>
18 #include <linux/signal.h>
19 #include <linux/sched.h>
20 #include <linux/ptrace.h>
21 #include <linux/interrupt.h>
22 #include <linux/slab.h>
23 #include <linux/random.h>
24 #include <linux/init.h>
25 #include <linux/irq.h>
26 #include <linux/proc_fs.h>
27 #include <linux/seq_file.h>
28 #include <linux/profile.h>
29 #include <linux/bitops.h>
30
31 #include <asm/system.h>
32 #include <asm/io.h>
33 #include <asm/uaccess.h>
34
35 volatile unsigned long irq_err_count;
36
37 void ack_bad_irq(unsigned int irq)
38 {
39         irq_err_count++;
40         printk(KERN_CRIT "Unexpected IRQ trap at vector %u\n", irq);
41 }
42
43 #ifdef CONFIG_SMP 
44 static char irq_user_affinity[NR_IRQS];
45
46 int
47 select_smp_affinity(unsigned int irq)
48 {
49         static int last_cpu;
50         int cpu = last_cpu + 1;
51
52         if (!irq_desc[irq].handler->set_affinity || irq_user_affinity[irq])
53                 return 1;
54
55         while (!cpu_possible(cpu))
56                 cpu = (cpu < (NR_CPUS-1) ? cpu + 1 : 0);
57         last_cpu = cpu;
58
59         irq_affinity[irq] = cpumask_of_cpu(cpu);
60         irq_desc[irq].handler->set_affinity(irq, cpumask_of_cpu(cpu));
61         return 0;
62 }
63 #endif /* CONFIG_SMP */
64
65 int
66 show_interrupts(struct seq_file *p, void *v)
67 {
68 #ifdef CONFIG_SMP
69         int j;
70 #endif
71         int irq = *(loff_t *) v;
72         struct irqaction * action;
73         unsigned long flags;
74
75 #ifdef CONFIG_SMP
76         if (irq == 0) {
77                 seq_puts(p, "           ");
78                 for_each_online_cpu(j)
79                         seq_printf(p, "CPU%d       ", j);
80                 seq_putc(p, '\n');
81         }
82 #endif
83
84         if (irq < ACTUAL_NR_IRQS) {
85                 spin_lock_irqsave(&irq_desc[irq].lock, flags);
86                 action = irq_desc[irq].action;
87                 if (!action) 
88                         goto unlock;
89                 seq_printf(p, "%3d: ", irq);
90 #ifndef CONFIG_SMP
91                 seq_printf(p, "%10u ", kstat_irqs(irq));
92 #else
93                 for_each_online_cpu(j)
94                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[irq]);
95 #endif
96                 seq_printf(p, " %14s", irq_desc[irq].handler->typename);
97                 seq_printf(p, "  %c%s",
98                         (action->flags & SA_INTERRUPT)?'+':' ',
99                         action->name);
100
101                 for (action=action->next; action; action = action->next) {
102                         seq_printf(p, ", %c%s",
103                                   (action->flags & SA_INTERRUPT)?'+':' ',
104                                    action->name);
105                 }
106
107                 seq_putc(p, '\n');
108 unlock:
109                 spin_unlock_irqrestore(&irq_desc[irq].lock, flags);
110         } else if (irq == ACTUAL_NR_IRQS) {
111 #ifdef CONFIG_SMP
112                 seq_puts(p, "IPI: ");
113                 for_each_online_cpu(j)
114                         seq_printf(p, "%10lu ", cpu_data[j].ipi_count);
115                 seq_putc(p, '\n');
116 #endif
117                 seq_printf(p, "ERR: %10lu\n", irq_err_count);
118         }
119         return 0;
120 }
121
122 /*
123  * handle_irq handles all normal device IRQ's (the special
124  * SMP cross-CPU interrupts have their own specific
125  * handlers).
126  */
127
128 #define MAX_ILLEGAL_IRQS 16
129
130 void
131 handle_irq(int irq, struct pt_regs * regs)
132 {       
133         /* 
134          * We ack quickly, we don't want the irq controller
135          * thinking we're snobs just because some other CPU has
136          * disabled global interrupts (we have already done the
137          * INT_ACK cycles, it's too late to try to pretend to the
138          * controller that we aren't taking the interrupt).
139          *
140          * 0 return value means that this irq is already being
141          * handled by some other CPU. (or is disabled)
142          */
143         static unsigned int illegal_count=0;
144         
145         if ((unsigned) irq > ACTUAL_NR_IRQS && illegal_count < MAX_ILLEGAL_IRQS ) {
146                 irq_err_count++;
147                 illegal_count++;
148                 printk(KERN_CRIT "device_interrupt: invalid interrupt %d\n",
149                        irq);
150                 return;
151         }
152
153         irq_enter();
154         local_irq_disable();
155         __do_IRQ(irq, regs);
156         local_irq_enable();
157         irq_exit();
158 }