/*
* arch/sh/kernel/smp.c
*
* SMP support for the SuperH processors.
*
* Copyright (C) 2002, 2003 Paul Mundt
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*/
#include <linux/config.h>
#include <linux/cache.h>
#include <linux/cpumask.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/threads.h>
#include <linux/module.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/sched.h>
#include <asm/atomic.h>
#include <asm/processor.h>
#include <asm/system.h>
#include <asm/mmu_context.h>
#include <asm/smp.h>
/*
* This was written with the Sega Saturn (SMP SH-2 7604) in mind,
* but is designed to be usable regardless if there's an MMU
* present or not.
*/
struct sh_cpuinfo cpu_data[NR_CPUS];
extern void per_cpu_trap_init(void);
cpumask_t cpu_possible_map;
cpumask_t cpu_online_map;
static atomic_t cpus_booted = ATOMIC_INIT(0);
/* These are defined by the board-specific code. */
/*
* Cause the function described by call_data to be executed on the passed
* cpu. When the function has finished, increment the finished field of
* call_data.
*/
void __smp_send_ipi(unsigned int cpu, unsigned int action);
/*
* Find the number of available processors
*/
unsigned int __smp_probe_cpus(void);
/*
* Start a particular processor
*/
void __smp_slave_init(unsigned int cpu);
/*
* Run specified function on a particular processor.
*/
void __smp_call_function(unsigned int cpu);
static inline void __init smp_store_cpu_info(unsigned int cpu)
{
cpu_data[cpu].loops_per_jiffy = loops_per_jiffy;
}
void __init smp_prepare_cpus(unsigned int max_cpus)
{
unsigned int cpu = smp_processor_id();
int i;
atomic_set(&cpus_booted, 1);
smp_store_cpu_info(cpu);
for (i = 0; i < __smp_probe_cpus(); i++)
cpu_set(i, cpu_possible_map);
}
void __devinit smp_prepare_boot_cpu(void)
{
unsigned int cpu = smp_processor_id();
cpu_set(cpu, cpu_online_map);
cpu_set(cpu, cpu_possible_map);
}
int __cpu_up(unsigned int cpu)
{
struct task_struct *tsk;
tsk = fork_idle(cpu);
if (IS_ERR(tsk))
panic("Failed forking idle task for cpu %d\n", cpu);
tsk->thread_info->cpu = cpu;
cpu_set(cpu, cpu_online_map);
return 0;
}
int start_secondary(void *unused)
{
unsigned int cpu = smp_processor_id();
atomic_inc(&init_mm.mm_count);
current->active_mm = &init_mm;
smp_store_cpu_info(cpu);
__smp_slave_init(cpu);
per_cpu_trap_init();
atomic_inc(&cpus_booted);
cpu_idle();
return 0;
}
void __init smp_cpus_done(unsigned int max_cpus)
{
smp_mb();
}
void smp_send_reschedule(int cpu)
{
__smp_send_ipi(cpu, SMP_MSG_RESCHEDULE);
}
static void stop_this_cpu(void *unused)
{
cpu_clear(smp_processor_id(), cpu_online_map);
local_irq_disable();
for (;;)
cpu_relax();
}
void smp_send_stop(void)
{
smp_call_function(stop_this_cpu, 0, 1, 0);
}
struct smp_fn_call_struct smp_fn_call = {
.lock = SPIN_LOCK_UNLOCKED,
.finished = ATOMIC_INIT(0),
};
/*
* The caller of this wants the passed function to run on every cpu. If wait
* is set, wait until all cpus have finished the function before returning.
* The lock is here to protect the call structure.
* You must not call this function with disabled interrupts or from a
* hardware interrupt handler or from a bottom half handler.
*/
int smp_call_function(void (*func)(void *info), void *info, int retry, int wait)
{
unsigned int nr_cpus = atomic_read(&cpus_booted);
int i;
if (nr_cpus < 2)
return 0;
/* Can deadlock when called with interrupts disabled */
WARN_ON(irqs_disabled());
spin_lock(&smp_fn_call.lock);
atomic_set(&smp_fn_call.finished, 0);
smp_fn_call.fn = func;
smp_fn_call.data = info;
for (i = 0; i < nr_cpus; i++)
if (i != smp_processor_id())
__smp_call_function(i);
if (wait)
while (atomic_read(&smp_fn_call.finished) != (nr_cpus - 1));
spin_unlock(&smp_fn_call.lock);
return 0;
}
/* Not really SMP stuff ... */
int setup_profiling_timer(unsigned int multiplier)
{
return 0;
}
