[PATCH] Alpha: convert to generic irq framework (alpha part)
[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 i = *(loff_t *) v;
72         struct irqaction * action;
73         unsigned long flags;
74
75 #ifdef CONFIG_SMP
76         if (i == 0) {
77                 seq_puts(p, "           ");
78                 for (i = 0; i < NR_CPUS; i++)
79                         if (cpu_online(i))
80                                 seq_printf(p, "CPU%d       ", i);
81                 seq_putc(p, '\n');
82         }
83 #endif
84
85         if (i < ACTUAL_NR_IRQS) {
86                 spin_lock_irqsave(&irq_desc[i].lock, flags);
87                 action = irq_desc[i].action;
88                 if (!action) 
89                         goto unlock;
90                 seq_printf(p, "%3d: ",i);
91 #ifndef CONFIG_SMP
92                 seq_printf(p, "%10u ", kstat_irqs(i));
93 #else
94                 for (j = 0; j < NR_CPUS; j++)
95                         if (cpu_online(j))
96                                 seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
97 #endif
98                 seq_printf(p, " %14s", irq_desc[i].handler->typename);
99                 seq_printf(p, "  %c%s",
100                         (action->flags & SA_INTERRUPT)?'+':' ',
101                         action->name);
102
103                 for (action=action->next; action; action = action->next) {
104                         seq_printf(p, ", %c%s",
105                                   (action->flags & SA_INTERRUPT)?'+':' ',
106                                    action->name);
107                 }
108
109                 seq_putc(p, '\n');
110 unlock:
111                 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
112         } else if (i == ACTUAL_NR_IRQS) {
113 #ifdef CONFIG_SMP
114                 seq_puts(p, "IPI: ");
115                 for (i = 0; i < NR_CPUS; i++)
116                         if (cpu_online(i))
117                                 seq_printf(p, "%10lu ", cpu_data[i].ipi_count);
118                 seq_putc(p, '\n');
119 #endif
120                 seq_printf(p, "ERR: %10lu\n", irq_err_count);
121         }
122         return 0;
123 }
124
125
126 /*
127  * handle_irq handles all normal device IRQ's (the special
128  * SMP cross-CPU interrupts have their own specific
129  * handlers).
130  */
131
132 #define MAX_ILLEGAL_IRQS 16
133
134 void
135 handle_irq(int irq, struct pt_regs * regs)
136 {       
137         /* 
138          * We ack quickly, we don't want the irq controller
139          * thinking we're snobs just because some other CPU has
140          * disabled global interrupts (we have already done the
141          * INT_ACK cycles, it's too late to try to pretend to the
142          * controller that we aren't taking the interrupt).
143          *
144          * 0 return value means that this irq is already being
145          * handled by some other CPU. (or is disabled)
146          */
147         static unsigned int illegal_count=0;
148         
149         if ((unsigned) irq > ACTUAL_NR_IRQS && illegal_count < MAX_ILLEGAL_IRQS ) {
150                 irq_err_count++;
151                 illegal_count++;
152                 printk(KERN_CRIT "device_interrupt: invalid interrupt %d\n",
153                        irq);
154                 return;
155         }
156
157         irq_enter();
158         local_irq_disable();
159         __do_IRQ(irq, regs);
160         local_irq_enable();
161         irq_exit();
162 }