linux/arch/ppc/platforms/chrp_smp.c

99 lines
2.1 KiB
C

/*
* Smp support for CHRP machines.
*
* Written by Cort Dougan (cort@cs.nmt.edu) borrowing a great
* deal of code from the sparc and intel versions.
*
* Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu>
*
*/
#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <asm/ptrace.h>
#include <asm/atomic.h>
#include <asm/irq.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/sections.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/smp.h>
#include <asm/residual.h>
#include <asm/time.h>
#include <asm/open_pic.h>
extern unsigned long smp_chrp_cpu_nr;
static int __init
smp_chrp_probe(void)
{
if (smp_chrp_cpu_nr > 1)
openpic_request_IPIs();
return smp_chrp_cpu_nr;
}
static void __devinit
smp_chrp_kick_cpu(int nr)
{
*(unsigned long *)KERNELBASE = nr;
asm volatile("dcbf 0,%0"::"r"(KERNELBASE):"memory");
}
static void __devinit
smp_chrp_setup_cpu(int cpu_nr)
{
if (OpenPIC_Addr)
do_openpic_setup_cpu();
}
static DEFINE_SPINLOCK(timebase_lock);
static unsigned int timebase_upper = 0, timebase_lower = 0;
void __devinit
smp_chrp_give_timebase(void)
{
spin_lock(&timebase_lock);
call_rtas("freeze-time-base", 0, 1, NULL);
timebase_upper = get_tbu();
timebase_lower = get_tbl();
spin_unlock(&timebase_lock);
while (timebase_upper || timebase_lower)
barrier();
call_rtas("thaw-time-base", 0, 1, NULL);
}
void __devinit
smp_chrp_take_timebase(void)
{
while (!(timebase_upper || timebase_lower))
barrier();
spin_lock(&timebase_lock);
set_tb(timebase_upper, timebase_lower);
timebase_upper = 0;
timebase_lower = 0;
spin_unlock(&timebase_lock);
printk("CPU %i taken timebase\n", smp_processor_id());
}
/* CHRP with openpic */
struct smp_ops_t chrp_smp_ops = {
.message_pass = smp_openpic_message_pass,
.probe = smp_chrp_probe,
.kick_cpu = smp_chrp_kick_cpu,
.setup_cpu = smp_chrp_setup_cpu,
.give_timebase = smp_chrp_give_timebase,
.take_timebase = smp_chrp_take_timebase,
};