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 = "CPM", .desc = "[EXT] CPU Measurement" },
  36         {.name = "QAI", .desc = "[I/O] QDIO Adapter Interrupt" },
  37         {.name = "QDI", .desc = "[I/O] QDIO Interrupt" },
  38         {.name = "DAS", .desc = "[I/O] DASD" },
  39         {.name = "C15", .desc = "[I/O] 3215" },
  40         {.name = "C70", .desc = "[I/O] 3270" },
  41         {.name = "TAP", .desc = "[I/O] Tape" },
  42         {.name = "VMR", .desc = "[I/O] Unit Record Devices" },
  43         {.name = "LCS", .desc = "[I/O] LCS" },
  44         {.name = "CLW", .desc = "[I/O] CLAW" },
  45         {.name = "CTC", .desc = "[I/O] CTC" },
  46         {.name = "APB", .desc = "[I/O] AP Bus" },
  47         {.name = "NMI", .desc = "[NMI] Machine Check" },
  48 };
  49
  50 /*
  51  * show_interrupts is needed by /proc/interrupts.
  52  */
  53 int show_interrupts(struct seq_file *p, void *v)
  54 {
  55         int i = *(loff_t *) v, j;
  56
  57         get_online_cpus();
  58         if (i == 0) {
  59                 seq_puts(p, "           ");
  60                 for_each_online_cpu(j)
  61                         seq_printf(p, "CPU%d       ",j);
  62                 seq_putc(p, '\n');
  63         }
  64
  65         if (i < NR_IRQS) {
  66                 seq_printf(p, "%s: ", intrclass_names[i].name);
  67 #ifndef CONFIG_SMP
  68                 seq_printf(p, "%10u ", kstat_irqs(i));
  69 #else
  70                 for_each_online_cpu(j)
  71                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
  72 #endif
  73                 if (intrclass_names[i].desc)
  74                         seq_printf(p, "  %s", intrclass_names[i].desc);
  75                 seq_putc(p, '\n');
  76         }
  77         put_online_cpus();
  78         return 0;
  79 }
  80
  81 /*
  82  * For compatibilty only. S/390 specific setup of interrupts et al. is done
  83  * much later in init_channel_subsystem().
  84  */
  85 void __init
  86 init_IRQ(void)
  87 {
  88         /* nothing... */
  89 }
  90
  91 /*
  92  * Switch to the asynchronous interrupt stack for softirq execution.
  93  */
  94 asmlinkage void do_softirq(void)
  95 {
  96         unsigned long flags, old, new;
  97
  98         if (in_interrupt())
  99                 return;
 100
 101         local_irq_save(flags);
 102
 103         if (local_softirq_pending()) {
 104                 /* Get current stack pointer. */
 105                 asm volatile("la %0,0(15)" : "=a" (old));
 106                 /* Check against async. stack address range. */
 107                 new = S390_lowcore.async_stack;
 108                 if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) {
 109                         /* Need to switch to the async. stack. */
 110                         new -= STACK_FRAME_OVERHEAD;
 111                         ((struct stack_frame *) new)->back_chain = old;
 112
 113                         asm volatile("   la    15,0(%0)\n"
 114                                      "   basr  14,%2\n"
 115                                      "   la    15,0(%1)\n"
 116                                      : : "a" (new), "a" (old),
 117                                          "a" (__do_softirq)
 118                                      : "0", "1", "2", "3", "4", "5", "14",
 119                                        "cc", "memory" );
 120                 } else
 121                         /* We are already on the async stack. */
 122                         __do_softirq();
 123         }
 124
 125         local_irq_restore(flags);
 126 }
 127
 128 #ifdef CONFIG_PROC_FS
 129 void init_irq_proc(void)
 130 {
 131         struct proc_dir_entry *root_irq_dir;
 132
 133         root_irq_dir = proc_mkdir("irq", NULL);
 134         create_prof_cpu_mask(root_irq_dir);
 135 }
 136 #endif