err.no Git - linux-2.6/blob - arch/powerpc/platforms/chrp/smp.c

   1 /*
   2  * Smp support for CHRP machines.
   3  *
   4  * Written by Cort Dougan (cort@cs.nmt.edu) borrowing a great
   5  * deal of code from the sparc and intel versions.
   6  *
   7  * Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu>
   8  *
   9  */
  10
  11 #include <linux/config.h>
  12 #include <linux/kernel.h>
  13 #include <linux/sched.h>
  14 #include <linux/smp.h>
  15 #include <linux/smp_lock.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/kernel_stat.h>
  18 #include <linux/delay.h>
  19 #include <linux/init.h>
  20 #include <linux/spinlock.h>
  21
  22 #include <asm/ptrace.h>
  23 #include <asm/atomic.h>
  24 #include <asm/irq.h>
  25 #include <asm/page.h>
  26 #include <asm/pgtable.h>
  27 #include <asm/sections.h>
  28 #include <asm/io.h>
  29 #include <asm/prom.h>
  30 #include <asm/smp.h>
  31 #include <asm/residual.h>
  32 #include <asm/time.h>
  33 #include <asm/open_pic.h>
  34 #include <asm/machdep.h>
  35
  36 extern unsigned long smp_chrp_cpu_nr;
  37
  38 static int __init smp_chrp_probe(void)
  39 {
  40         if (smp_chrp_cpu_nr > 1)
  41                 openpic_request_IPIs();
  42
  43         return smp_chrp_cpu_nr;
  44 }
  45
  46 static void __devinit smp_chrp_kick_cpu(int nr)
  47 {
  48         *(unsigned long *)KERNELBASE = nr;
  49         asm volatile("dcbf 0,%0"::"r"(KERNELBASE):"memory");
  50 }
  51
  52 static void __devinit smp_chrp_setup_cpu(int cpu_nr)
  53 {
  54         if (OpenPIC_Addr)
  55                 do_openpic_setup_cpu();
  56 }
  57
  58 static DEFINE_SPINLOCK(timebase_lock);
  59 static unsigned int timebase_upper = 0, timebase_lower = 0;
  60
  61 void __devinit smp_chrp_give_timebase(void)
  62 {
  63         spin_lock(&timebase_lock);
  64         rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL);
  65         timebase_upper = get_tbu();
  66         timebase_lower = get_tbl();
  67         spin_unlock(&timebase_lock);
  68
  69         while (timebase_upper || timebase_lower)
  70                 barrier();
  71         rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL);
  72 }
  73
  74 void __devinit smp_chrp_take_timebase(void)
  75 {
  76         while (!(timebase_upper || timebase_lower))
  77                 barrier();
  78         spin_lock(&timebase_lock);
  79         set_tb(timebase_upper, timebase_lower);
  80         timebase_upper = 0;
  81         timebase_lower = 0;
  82         spin_unlock(&timebase_lock);
  83         printk("CPU %i taken timebase\n", smp_processor_id());
  84 }
  85
  86 /* CHRP with openpic */
  87 struct smp_ops_t chrp_smp_ops = {
  88         .message_pass = smp_openpic_message_pass,
  89         .probe = smp_chrp_probe,
  90         .kick_cpu = smp_chrp_kick_cpu,
  91         .setup_cpu = smp_chrp_setup_cpu,
  92         .give_timebase = smp_chrp_give_timebase,
  93         .take_timebase = smp_chrp_take_timebase,
  94 };