[S390] lcs: 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 = "NMI", .desc = "[NMI] Machine Check" },
44 };
45
46 /*
47  * show_interrupts is needed by /proc/interrupts.
48  */
49 int show_interrupts(struct seq_file *p, void *v)
50 {
51         int i = *(loff_t *) v, j;
52
53         get_online_cpus();
54         if (i == 0) {
55                 seq_puts(p, "           ");
56                 for_each_online_cpu(j)
57                         seq_printf(p, "CPU%d       ",j);
58                 seq_putc(p, '\n');
59         }
60
61         if (i < NR_IRQS) {
62                 seq_printf(p, "%s: ", intrclass_names[i].name);
63 #ifndef CONFIG_SMP
64                 seq_printf(p, "%10u ", kstat_irqs(i));
65 #else
66                 for_each_online_cpu(j)
67                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
68 #endif
69                 if (intrclass_names[i].desc)
70                         seq_printf(p, "  %s", intrclass_names[i].desc);
71                 seq_putc(p, '\n');
72         }
73         put_online_cpus();
74         return 0;
75 }
76
77 /*
78  * For compatibilty only. S/390 specific setup of interrupts et al. is done
79  * much later in init_channel_subsystem().
80  */
81 void __init
82 init_IRQ(void)
83 {
84         /* nothing... */
85 }
86
87 /*
88  * Switch to the asynchronous interrupt stack for softirq execution.
89  */
90 asmlinkage void do_softirq(void)
91 {
92         unsigned long flags, old, new;
93
94         if (in_interrupt())
95                 return;
96
97         local_irq_save(flags);
98
99         if (local_softirq_pending()) {
100                 /* Get current stack pointer. */
101                 asm volatile("la %0,0(15)" : "=a" (old));
102                 /* Check against async. stack address range. */
103                 new = S390_lowcore.async_stack;
104                 if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) {
105                         /* Need to switch to the async. stack. */
106                         new -= STACK_FRAME_OVERHEAD;
107                         ((struct stack_frame *) new)->back_chain = old;
108
109                         asm volatile("   la    15,0(%0)\n"
110                                      "   basr  14,%2\n"
111                                      "   la    15,0(%1)\n"
112                                      : : "a" (new), "a" (old),
113                                          "a" (__do_softirq)
114                                      : "0", "1", "2", "3", "4", "5", "14",
115                                        "cc", "memory" );
116                 } else
117                         /* We are already on the async stack. */
118                         __do_softirq();
119         }
120
121         local_irq_restore(flags);
122 }
123
124 #ifdef CONFIG_PROC_FS
125 void init_irq_proc(void)
126 {
127         struct proc_dir_entry *root_irq_dir;
128
129         root_irq_dir = proc_mkdir("irq", NULL);
130         create_prof_cpu_mask(root_irq_dir);
131 }
132 #endif