Merge git://git.kernel.org/pub/scm/linux/kernel/git/brodo/pcmcia-fixes-2.6
[linux-2.6] / arch / s390 / kernel / irq.c
1 /*
2  *  arch/s390/kernel/irq.c
3  *
4  *    Copyright IBM Corp. 2004,2007
5  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
6  *               Thomas Spatzier (tspat@de.ibm.com)
7  *
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>
17 #include <linux/proc_fs.h>
18 #include <linux/profile.h>
19
20 /*
21  * show_interrupts is needed by /proc/interrupts.
22  */
23 int 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         get_online_cpus();
29         if (i == 0) {
30                 seq_puts(p, "           ");
31                 for_each_online_cpu(j)
32                         seq_printf(p, "CPU%d       ",j);
33                 seq_putc(p, '\n');
34         }
35
36         if (i < NR_IRQS) {
37                 seq_printf(p, "%s: ", intrclass_names[i]);
38 #ifndef CONFIG_SMP
39                 seq_printf(p, "%10u ", kstat_irqs(i));
40 #else
41                 for_each_online_cpu(j)
42                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
43 #endif
44                 seq_putc(p, '\n');
45
46         }
47         put_online_cpus();
48         return 0;
49 }
50
51 /*
52  * For compatibilty only. S/390 specific setup of interrupts et al. is done
53  * much later in init_channel_subsystem().
54  */
55 void __init
56 init_IRQ(void)
57 {
58         /* nothing... */
59 }
60
61 /*
62  * Switch to the asynchronous interrupt stack for softirq execution.
63  */
64 asmlinkage void do_softirq(void)
65 {
66         unsigned long flags, old, new;
67
68         if (in_interrupt())
69                 return;
70
71         local_irq_save(flags);
72
73         if (local_softirq_pending()) {
74                 /* Get current stack pointer. */
75                 asm volatile("la %0,0(15)" : "=a" (old));
76                 /* Check against async. stack address range. */
77                 new = S390_lowcore.async_stack;
78                 if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) {
79                         /* Need to switch to the async. stack. */
80                         new -= STACK_FRAME_OVERHEAD;
81                         ((struct stack_frame *) new)->back_chain = old;
82
83                         asm volatile("   la    15,0(%0)\n"
84                                      "   basr  14,%2\n"
85                                      "   la    15,0(%1)\n"
86                                      : : "a" (new), "a" (old),
87                                          "a" (__do_softirq)
88                                      : "0", "1", "2", "3", "4", "5", "14",
89                                        "cc", "memory" );
90                 } else
91                         /* We are already on the async stack. */
92                         __do_softirq();
93         }
94
95         local_irq_restore(flags);
96 }
97
98 void init_irq_proc(void)
99 {
100         struct proc_dir_entry *root_irq_dir;
101
102         root_irq_dir = proc_mkdir("irq", NULL);
103         create_prof_cpu_mask(root_irq_dir);
104 }