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/segment.h>
  23 #include <asm/timer.h>
  24 #include <asm/mostek.h>
  25 #include <asm/system.h>
  26 #include <asm/irq.h>
  27 #include <asm/io.h>
  28
  29 extern unsigned long lvl14_save[5];
  30 static unsigned long *linux_lvl14 = NULL;
  31 static unsigned long obp_lvl14[4];
  32
  33 /*
  34  * Call with timer IRQ closed.
  35  * First time we do it with disable_irq, later prom code uses spin_lock_irq().
  36  */
  37 void install_linux_ticker(void)
  38 {
  39
  40         if (!linux_lvl14)
  41                 return;
  42         linux_lvl14[0] =  lvl14_save[0];
  43         linux_lvl14[1] =  lvl14_save[1];
  44         linux_lvl14[2] =  lvl14_save[2];
  45         linux_lvl14[3] =  lvl14_save[3];
  46 }
  47
  48 void install_obp_ticker(void)
  49 {
  50
  51         if (!linux_lvl14)
  52                 return;
  53         linux_lvl14[0] =  obp_lvl14[0];
  54         linux_lvl14[1] =  obp_lvl14[1];
  55         linux_lvl14[2] =  obp_lvl14[2];
  56         linux_lvl14[3] =  obp_lvl14[3];
  57 }
  58
  59 void claim_ticker14(irqreturn_t (*handler)(int, void *, struct pt_regs *),
  60                     int irq_nr, unsigned int timeout )
  61 {
  62         int cpu = smp_processor_id();
  63
  64         /* first we copy the obp handler instructions
  65          */
  66         disable_irq(irq_nr);
  67         if (!handler)
  68                 return;
  69
  70         linux_lvl14 = (unsigned long *)lvl14_save[4];
  71         obp_lvl14[0] = linux_lvl14[0];
  72         obp_lvl14[1] = linux_lvl14[1];
  73         obp_lvl14[2] = linux_lvl14[2];
  74         obp_lvl14[3] = linux_lvl14[3];
  75
  76         if (!request_irq(irq_nr,
  77                          handler,
  78                          (SA_INTERRUPT | SA_STATIC_ALLOC),
  79                          "counter14",
  80                          NULL)) {
  81                 install_linux_ticker();
  82                 load_profile_irq(cpu, timeout);
  83                 enable_irq(irq_nr);
  84         }
  85 }