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