/*
* 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>
#include <asm/machdep.h>
#include <asm/smp.h>
#include <asm/mpic.h>
extern unsigned long smp_chrp_cpu_nr;
static int __init smp_chrp_probe(void)
{
struct device_node *cpus = NULL;
unsigned int *reg;
int reglen;
int ncpus = 0;
int cpuid;
unsigned int phys;
/* Count CPUs in the device-tree */
cpuid = 1; /* the boot cpu is logical cpu 0 */
while ((cpus = of_find_node_by_type(cpus, "cpu")) != NULL) {
phys = ncpus;
reg = (unsigned int *) get_property(cpus, "reg", ®len);
if (reg && reglen >= sizeof(unsigned int))
/* hmmm, not having a reg property would be bad */
phys = *reg;
if (phys != boot_cpuid_phys) {
set_hard_smp_processor_id(cpuid, phys);
++cpuid;
}
++ncpus;
}
printk(KERN_INFO "CHRP SMP probe found %d cpus\n", ncpus);
/* Nothing more to do if less than 2 of them */
if (ncpus <= 1)
return 1;
mpic_request_ipis();
return ncpus;
}
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)
{
mpic_setup_this_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);
rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL);
timebase_upper = get_tbu();
timebase_lower = get_tbl();
spin_unlock(&timebase_lock);
while (timebase_upper || timebase_lower)
barrier();
rtas_call(rtas_token("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_mpic_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,
};
