[S390] claw: add support for irq statistics
[linux-2.6.git] / arch / s390 / kernel / irq.c
1 /*
2  *    Copyright IBM Corp. 2004,2010
3  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
4  *               Thomas Spatzier (tspat@de.ibm.com)
5  *
6  * This file contains interrupt related functions.
7  */
8
9 #include <linux/module.h>
10 #include <linux/kernel.h>
11 #include <linux/kernel_stat.h>
12 #include <linux/interrupt.h>
13 #include <linux/seq_file.h>
14 #include <linux/cpu.h>
15 #include <linux/proc_fs.h>
16 #include <linux/profile.h>
17
18 struct irq_class {
19         char *name;
20         char *desc;
21 };
22
23 static const struct irq_class intrclass_names[] = {
24         {.name = "EXT" },
25         {.name = "I/O" },
26         {.name = "CLK", .desc = "[EXT] Clock Comparator" },
27         {.name = "IPI", .desc = "[EXT] Signal Processor" },
28         {.name = "TMR", .desc = "[EXT] CPU Timer" },
29         {.name = "TAL", .desc = "[EXT] Timing Alert" },
30         {.name = "PFL", .desc = "[EXT] Pseudo Page Fault" },
31         {.name = "DSD", .desc = "[EXT] DASD Diag" },
32         {.name = "VRT", .desc = "[EXT] Virtio" },
33         {.name = "SCP", .desc = "[EXT] Service Call" },
34         {.name = "IUC", .desc = "[EXT] IUCV" },
35         {.name = "QAI", .desc = "[I/O] QDIO Adapter Interrupt" },
36         {.name = "QDI", .desc = "[I/O] QDIO Interrupt" },
37         {.name = "DAS", .desc = "[I/O] DASD" },
38         {.name = "C15", .desc = "[I/O] 3215" },
39         {.name = "C70", .desc = "[I/O] 3270" },
40         {.name = "TAP", .desc = "[I/O] Tape" },
41         {.name = "VMR", .desc = "[I/O] Unit Record Devices" },
42         {.name = "LCS", .desc = "[I/O] LCS" },
43         {.name = "CLW", .desc = "[I/O] CLAW" },
44         {.name = "NMI", .desc = "[NMI] Machine Check" },
45 };
46
47 /*
48  * show_interrupts is needed by /proc/interrupts.
49  */
50 int show_interrupts(struct seq_file *p, void *v)
51 {
52         int i = *(loff_t *) v, j;
53
54         get_online_cpus();
55         if (i == 0) {
56                 seq_puts(p, "           ");
57                 for_each_online_cpu(j)
58                         seq_printf(p, "CPU%d       ",j);
59                 seq_putc(p, '\n');
60         }
61
62         if (i < NR_IRQS) {
63                 seq_printf(p, "%s: ", intrclass_names[i].name);
64 #ifndef CONFIG_SMP
65                 seq_printf(p, "%10u ", kstat_irqs(i));
66 #else
67                 for_each_online_cpu(j)
68                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
69 #endif
70                 if (intrclass_names[i].desc)
71                         seq_printf(p, "  %s", intrclass_names[i].desc);
72                 seq_putc(p, '\n');
73         }
74         put_online_cpus();
75         return 0;
76 }
77
78 /*
79  * For compatibilty only. S/390 specific setup of interrupts et al. is done
80  * much later in init_channel_subsystem().
81  */
82 void __init
83 init_IRQ(void)
84 {
85         /* nothing... */
86 }
87
88 /*
89  * Switch to the asynchronous interrupt stack for softirq execution.
90  */
91 asmlinkage void do_softirq(void)
92 {
93         unsigned long flags, old, new;
94
95         if (in_interrupt())
96                 return;
97
98         local_irq_save(flags);
99
100         if (local_softirq_pending()) {
101                 /* Get current stack pointer. */
102                 asm volatile("la %0,0(15)" : "=a" (old));
103                 /* Check against async. stack address range. */
104                 new = S390_lowcore.async_stack;
105                 if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) {
106                         /* Need to switch to the async. stack. */
107                         new -= STACK_FRAME_OVERHEAD;
108                         ((struct stack_frame *) new)->back_chain = old;
109
110                         asm volatile("   la    15,0(%0)\n"
111                                      "   basr  14,%2\n"
112                                      "   la    15,0(%1)\n"
113                                      : : "a" (new), "a" (old),
114                                          "a" (__do_softirq)
115                                      : "0", "1", "2", "3", "4", "5", "14",
116                                        "cc", "memory" );
117                 } else
118                         /* We are already on the async stack. */
119                         __do_softirq();
120         }
121
122         local_irq_restore(flags);
123 }
124
125 #ifdef CONFIG_PROC_FS
126 void init_irq_proc(void)
127 {
128         struct proc_dir_entry *root_irq_dir;
129
130         root_irq_dir = proc_mkdir("irq", NULL);
131         create_prof_cpu_mask(root_irq_dir);
132 }
133 #endif