Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
[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         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  */
54 void __init
55 init_IRQ(void)
56 {
57         /* nothing... */
58 }
59
60 /*
61  * Switch to the asynchronous interrupt stack for softirq execution.
62  */
63 asmlinkage void do_softirq(void)
64 {
65         unsigned long flags, old, new;
66
67         if (in_interrupt())
68                 return;
69
70         local_irq_save(flags);
71
72         if (local_softirq_pending()) {
73                 /* Get current stack pointer. */
74                 asm volatile("la %0,0(15)" : "=a" (old));
75                 /* Check against async. stack address range. */
76                 new = S390_lowcore.async_stack;
77                 if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) {
78                         /* Need to switch to the async. stack. */
79                         new -= STACK_FRAME_OVERHEAD;
80                         ((struct stack_frame *) new)->back_chain = old;
81
82                         asm volatile("   la    15,0(%0)\n"
83                                      "   basr  14,%2\n"
84                                      "   la    15,0(%1)\n"
85                                      : : "a" (new), "a" (old),
86                                          "a" (__do_softirq)
87                                      : "0", "1", "2", "3", "4", "5", "14",
88                                        "cc", "memory" );
89                 } else
90                         /* We are already on the async stack. */
91                         __do_softirq();
92         }
93
94         local_irq_restore(flags);
95 }
96
97 void init_irq_proc(void)
98 {
99         struct proc_dir_entry *root_irq_dir;
100
101         root_irq_dir = proc_mkdir("irq", NULL);
102         create_prof_cpu_mask(root_irq_dir);
103 }