arch/sparc/kernel/tick14.c

   1 /* tick14.c
   2  * linux/arch/sparc/kernel/tick14.c
   3  *
   4  * Copyright (C) 1996 David Redman (djhr@tadpole.co.uk)
   5  *
   6  * This file handles the Sparc specific level14 ticker
   7  * This is really useful for profiling OBP uses it for keyboard
   8  * aborts and other stuff.
   9  *
  10  *
  11  */
  12 #include <linux/errno.h>
  13 #include <linux/sched.h>
  14 #include <linux/kernel.h>
  15 #include <linux/param.h>
  16 #include <linux/string.h>
  17 #include <linux/mm.h>
  18 #include <linux/timex.h>
  19 #include <linux/interrupt.h>
  20
  21 #include <asm/oplib.h>
  22 #include <asm/timer.h>
  23 #include <asm/mostek.h>
  24 #include <asm/system.h>
  25 #include <asm/irq.h>
  26 #include <asm/io.h>
  27
  28 extern unsigned long lvl14_save[5];
  29 static unsigned long *linux_lvl14 = NULL;
  30 static unsigned long obp_lvl14[4];
  31
  32 /*
  33  * Call with timer IRQ closed.
  34  * First time we do it with disable_irq, later prom code uses spin_lock_irq().
  35  */
  36 void install_linux_ticker(void)
  37 {
  38
  39         if (!linux_lvl14)
  40                 return;
  41         linux_lvl14[0] =  lvl14_save[0];
  42         linux_lvl14[1] =  lvl14_save[1];
  43         linux_lvl14[2] =  lvl14_save[2];
  44         linux_lvl14[3] =  lvl14_save[3];
  45 }
  46
  47 void install_obp_ticker(void)
  48 {
  49
  50         if (!linux_lvl14)
  51                 return;
  52         linux_lvl14[0] =  obp_lvl14[0];
  53         linux_lvl14[1] =  obp_lvl14[1];
  54         linux_lvl14[2] =  obp_lvl14[2];
  55         linux_lvl14[3] =  obp_lvl14[3];
  56 }
  57
  58 void claim_ticker14(irqreturn_t (*handler)(int, void *),
  59                     int irq_nr, unsigned int timeout )
  60 {
  61         int cpu = smp_processor_id();
  62
  63         /* first we copy the obp handler instructions
  64          */
  65         disable_irq(irq_nr);
  66         if (!handler)
  67                 return;
  68
  69         linux_lvl14 = (unsigned long *)lvl14_save[4];
  70         obp_lvl14[0] = linux_lvl14[0];
  71         obp_lvl14[1] = linux_lvl14[1];
  72         obp_lvl14[2] = linux_lvl14[2];
  73         obp_lvl14[3] = linux_lvl14[3];
  74
  75         if (!request_irq(irq_nr,
  76                          handler,
  77                          (IRQF_DISABLED | SA_STATIC_ALLOC),
  78                          "counter14",
  79                          NULL)) {
  80                 install_linux_ticker();
  81                 load_profile_irq(cpu, timeout);
  82                 enable_irq(irq_nr);
  83         }
  84 }