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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * arch/s390/kernel/irq.c
3 *
Heiko Carstens55dff522007-02-05 21:16:44 +01004 * Copyright IBM Corp. 2004,2007
Linus Torvalds1da177e2005-04-16 15:20:36 -07005 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
Heiko Carstens55dff522007-02-05 21:16:44 +01006 * Thomas Spatzier (tspat@de.ibm.com)
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 *
8 * This file contains interrupt related functions.
9 */
10
11#include <linux/module.h>
12#include <linux/kernel.h>
13#include <linux/kernel_stat.h>
14#include <linux/interrupt.h>
15#include <linux/seq_file.h>
16#include <linux/cpu.h>
Heiko Carstens55dff522007-02-05 21:16:44 +010017#include <linux/proc_fs.h>
18#include <linux/profile.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019
20/*
21 * show_interrupts is needed by /proc/interrupts.
22 */
23int show_interrupts(struct seq_file *p, void *v)
24{
25 static const char *intrclass_names[] = { "EXT", "I/O", };
26 int i = *(loff_t *) v, j;
27
28 if (i == 0) {
29 seq_puts(p, " ");
30 for_each_online_cpu(j)
31 seq_printf(p, "CPU%d ",j);
32 seq_putc(p, '\n');
33 }
34
35 if (i < NR_IRQS) {
36 seq_printf(p, "%s: ", intrclass_names[i]);
37#ifndef CONFIG_SMP
38 seq_printf(p, "%10u ", kstat_irqs(i));
39#else
40 for_each_online_cpu(j)
41 seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
42#endif
43 seq_putc(p, '\n');
44
45 }
46
47 return 0;
48}
49
50/*
51 * For compatibilty only. S/390 specific setup of interrupts et al. is done
52 * much later in init_channel_subsystem().
53 */
54void __init
55init_IRQ(void)
56{
57 /* nothing... */
58}
59
60/*
61 * Switch to the asynchronous interrupt stack for softirq execution.
62 */
63extern void __do_softirq(void);
64
65asmlinkage void do_softirq(void)
66{
67 unsigned long flags, old, new;
68
69 if (in_interrupt())
70 return;
71
72 local_irq_save(flags);
73
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 if (local_softirq_pending()) {
75 /* Get current stack pointer. */
76 asm volatile("la %0,0(15)" : "=a" (old));
77 /* Check against async. stack address range. */
78 new = S390_lowcore.async_stack;
79 if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) {
80 /* Need to switch to the async. stack. */
81 new -= STACK_FRAME_OVERHEAD;
82 ((struct stack_frame *) new)->back_chain = old;
83
84 asm volatile(" la 15,0(%0)\n"
85 " basr 14,%2\n"
86 " la 15,0(%1)\n"
87 : : "a" (new), "a" (old),
88 "a" (__do_softirq)
89 : "0", "1", "2", "3", "4", "5", "14",
90 "cc", "memory" );
91 } else
92 /* We are already on the async stack. */
93 __do_softirq();
94 }
95
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 local_irq_restore(flags);
97}
Heiko Carstens55dff522007-02-05 21:16:44 +010098
99void init_irq_proc(void)
100{
101 struct proc_dir_entry *root_irq_dir;
102
103 root_irq_dir = proc_mkdir("irq", NULL);
104 create_prof_cpu_mask(root_irq_dir);
105}