alpha: add performance monitor interrupt counter
[sfrench/cifs-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/random.h>
22 #include <linux/init.h>
23 #include <linux/irq.h>
24 #include <linux/proc_fs.h>
25 #include <linux/seq_file.h>
26 #include <linux/profile.h>
27 #include <linux/bitops.h>
28
29 #include <asm/system.h>
30 #include <asm/io.h>
31 #include <asm/uaccess.h>
32
33 volatile unsigned long irq_err_count;
34 DEFINE_PER_CPU(unsigned long, irq_pmi_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 irq_select_affinity(unsigned int irq)
46 {
47         static int last_cpu;
48         int cpu = last_cpu + 1;
49
50         if (!irq_desc[irq].chip->set_affinity || irq_user_affinity[irq])
51                 return 1;
52
53         while (!cpu_possible(cpu) ||
54                !cpumask_test_cpu(cpu, irq_default_affinity))
55                 cpu = (cpu < (NR_CPUS-1) ? cpu + 1 : 0);
56         last_cpu = cpu;
57
58         cpumask_copy(irq_desc[irq].affinity, cpumask_of(cpu));
59         irq_desc[irq].chip->set_affinity(irq, cpumask_of(cpu));
60         return 0;
61 }
62 #endif /* CONFIG_SMP */
63
64 int
65 show_interrupts(struct seq_file *p, void *v)
66 {
67         int j;
68         int irq = *(loff_t *) v;
69         struct irqaction * action;
70         unsigned long flags;
71
72 #ifdef CONFIG_SMP
73         if (irq == 0) {
74                 seq_puts(p, "           ");
75                 for_each_online_cpu(j)
76                         seq_printf(p, "CPU%d       ", j);
77                 seq_putc(p, '\n');
78         }
79 #endif
80
81         if (irq < ACTUAL_NR_IRQS) {
82                 raw_spin_lock_irqsave(&irq_desc[irq].lock, flags);
83                 action = irq_desc[irq].action;
84                 if (!action) 
85                         goto unlock;
86                 seq_printf(p, "%3d: ", irq);
87 #ifndef CONFIG_SMP
88                 seq_printf(p, "%10u ", kstat_irqs(irq));
89 #else
90                 for_each_online_cpu(j)
91                         seq_printf(p, "%10u ", kstat_irqs_cpu(irq, j));
92 #endif
93                 seq_printf(p, " %14s", irq_desc[irq].chip->name);
94                 seq_printf(p, "  %c%s",
95                         (action->flags & IRQF_DISABLED)?'+':' ',
96                         action->name);
97
98                 for (action=action->next; action; action = action->next) {
99                         seq_printf(p, ", %c%s",
100                                   (action->flags & IRQF_DISABLED)?'+':' ',
101                                    action->name);
102                 }
103
104                 seq_putc(p, '\n');
105 unlock:
106                 raw_spin_unlock_irqrestore(&irq_desc[irq].lock, flags);
107         } else if (irq == ACTUAL_NR_IRQS) {
108 #ifdef CONFIG_SMP
109                 seq_puts(p, "IPI: ");
110                 for_each_online_cpu(j)
111                         seq_printf(p, "%10lu ", cpu_data[j].ipi_count);
112                 seq_putc(p, '\n');
113 #endif
114                 seq_puts(p, "PMI: ");
115                 for_each_online_cpu(j)
116                         seq_printf(p, "%10lu ", per_cpu(irq_pmi_count, j));
117                 seq_puts(p, "          Performance Monitoring\n");
118                 seq_printf(p, "ERR: %10lu\n", irq_err_count);
119         }
120         return 0;
121 }
122
123 /*
124  * handle_irq handles all normal device IRQ's (the special
125  * SMP cross-CPU interrupts have their own specific
126  * handlers).
127  */
128
129 #define MAX_ILLEGAL_IRQS 16
130
131 void
132 handle_irq(int irq)
133 {       
134         /* 
135          * We ack quickly, we don't want the irq controller
136          * thinking we're snobs just because some other CPU has
137          * disabled global interrupts (we have already done the
138          * INT_ACK cycles, it's too late to try to pretend to the
139          * controller that we aren't taking the interrupt).
140          *
141          * 0 return value means that this irq is already being
142          * handled by some other CPU. (or is disabled)
143          */
144         static unsigned int illegal_count=0;
145         
146         if ((unsigned) irq > ACTUAL_NR_IRQS && illegal_count < MAX_ILLEGAL_IRQS ) {
147                 irq_err_count++;
148                 illegal_count++;
149                 printk(KERN_CRIT "device_interrupt: invalid interrupt %d\n",
150                        irq);
151                 return;
152         }
153
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 }