[PATCH] minimal alpha pt_regs fixes
[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/kernel.h>
14 #include <linux/module.h>
15 #include <linux/errno.h>
16 #include <linux/kernel_stat.h>
17 #include <linux/signal.h>
18 #include <linux/sched.h>
19 #include <linux/ptrace.h>
20 #include <linux/interrupt.h>
21 #include <linux/slab.h>
22 #include <linux/random.h>
23 #include <linux/init.h>
24 #include <linux/irq.h>
25 #include <linux/proc_fs.h>
26 #include <linux/seq_file.h>
27 #include <linux/profile.h>
28 #include <linux/bitops.h>
29
30 #include <asm/system.h>
31 #include <asm/io.h>
32 #include <asm/uaccess.h>
33
34 volatile unsigned long irq_err_count;
35
36 void ack_bad_irq(unsigned int irq)
37 {
38         irq_err_count++;
39         printk(KERN_CRIT "Unexpected IRQ trap at vector %u\n", irq);
40 }
41
42 #ifdef CONFIG_SMP 
43 static char irq_user_affinity[NR_IRQS];
44
45 int
46 select_smp_affinity(unsigned int irq)
47 {
48         static int last_cpu;
49         int cpu = last_cpu + 1;
50
51         if (!irq_desc[irq].chip->set_affinity || irq_user_affinity[irq])
52                 return 1;
53
54         while (!cpu_possible(cpu))
55                 cpu = (cpu < (NR_CPUS-1) ? cpu + 1 : 0);
56         last_cpu = cpu;
57
58         irq_desc[irq].affinity = cpumask_of_cpu(cpu);
59         irq_desc[irq].chip->set_affinity(irq, cpumask_of_cpu(cpu));
60         return 0;
61 }
62 #endif /* CONFIG_SMP */
63
64 int
65 show_interrupts(struct seq_file *p, void *v)
66 {
67 #ifdef CONFIG_SMP
68         int j;
69 #endif
70         int irq = *(loff_t *) v;
71         struct irqaction * action;
72         unsigned long flags;
73
74 #ifdef CONFIG_SMP
75         if (irq == 0) {
76                 seq_puts(p, "           ");
77                 for_each_online_cpu(j)
78                         seq_printf(p, "CPU%d       ", j);
79                 seq_putc(p, '\n');
80         }
81 #endif
82
83         if (irq < ACTUAL_NR_IRQS) {
84                 spin_lock_irqsave(&irq_desc[irq].lock, flags);
85                 action = irq_desc[irq].action;
86                 if (!action) 
87                         goto unlock;
88                 seq_printf(p, "%3d: ", irq);
89 #ifndef CONFIG_SMP
90                 seq_printf(p, "%10u ", kstat_irqs(irq));
91 #else
92                 for_each_online_cpu(j)
93                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[irq]);
94 #endif
95                 seq_printf(p, " %14s", irq_desc[irq].chip->typename);
96                 seq_printf(p, "  %c%s",
97                         (action->flags & IRQF_DISABLED)?'+':' ',
98                         action->name);
99
100                 for (action=action->next; action; action = action->next) {
101                         seq_printf(p, ", %c%s",
102                                   (action->flags & IRQF_DISABLED)?'+':' ',
103                                    action->name);
104                 }
105
106                 seq_putc(p, '\n');
107 unlock:
108                 spin_unlock_irqrestore(&irq_desc[irq].lock, flags);
109         } else if (irq == ACTUAL_NR_IRQS) {
110 #ifdef CONFIG_SMP
111                 seq_puts(p, "IPI: ");
112                 for_each_online_cpu(j)
113                         seq_printf(p, "%10lu ", cpu_data[j].ipi_count);
114                 seq_putc(p, '\n');
115 #endif
116                 seq_printf(p, "ERR: %10lu\n", irq_err_count);
117         }
118         return 0;
119 }
120
121 /*
122  * handle_irq handles all normal device IRQ's (the special
123  * SMP cross-CPU interrupts have their own specific
124  * handlers).
125  */
126
127 #define MAX_ILLEGAL_IRQS 16
128
129 void
130 handle_irq(int irq, struct pt_regs * regs)
131 {       
132         struct pt_regs *old_regs;
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         old_regs = set_irq_regs(regs);
154         irq_enter();
155         /*
156          * __do_IRQ() must be called with IPL_MAX. Note that we do not
157          * explicitly enable interrupts afterwards - some MILO PALcode
158          * (namely LX164 one) seems to have severe problems with RTI
159          * at IPL 0.
160          */
161         local_irq_disable();
162         __do_IRQ(irq);
163         irq_exit();
164         set_irq_regs(old_regs);
165 }