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/*
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
*/
#include <linux/percpu.h>
#include <asm/pgalloc.h>
#include <asm/tlb.h>
#ifdef CONFIG_SMP
#include <linux/sched.h>
#include <linux/module.h>
#include <linux/threads.h>
#include <linux/interrupt.h>
#include <linux/err.h>
#include <linux/hardirq.h>
#include <asm/smp.h>
#include <asm/processor.h>
#include <asm/spinlock.h>
#include <kern.h>
#include <irq_user.h>
#include <os.h>
/* Per CPU bogomips and other parameters
* The only piece used here is the ipi pipe, which is set before SMP is
* started and never changed.
*/
struct cpuinfo_um cpu_data[NR_CPUS];
/* A statistic, can be a little off */
int num_reschedules_sent = 0;
/* Not changed after boot */
struct task_struct *idle_threads[NR_CPUS];
void smp_send_reschedule(int cpu)
{
os_write_file(cpu_data[cpu].ipi_pipe[1], "R", 1);
num_reschedules_sent++;
}
void smp_send_stop(void)
{
int i;
printk(KERN_INFO "Stopping all CPUs...");
for (i = 0; i < num_online_cpus(); i++) {
if (i == current_thread->cpu)
continue;
os_write_file(cpu_data[i].ipi_pipe[1], "S", 1);
}
printk(KERN_CONT "done\n");
}
static cpumask_t smp_commenced_mask = CPU_MASK_NONE;
static cpumask_t cpu_callin_map = CPU_MASK_NONE;
static int idle_proc(void *cpup)
{
int cpu = (int) cpup, err;
err = os_pipe(cpu_data[cpu].ipi_pipe, 1, 1);
if (err < 0)
panic("CPU#%d failed to create IPI pipe, err = %d", cpu, -err);
os_set_fd_async(cpu_data[cpu].ipi_pipe[0]);
wmb();
if (cpu_test_and_set(cpu, cpu_callin_map)) {
printk(KERN_ERR "huh, CPU#%d already present??\n", cpu);
BUG();
}
while (!cpu_isset(cpu, smp_commenced_mask))
cpu_relax();
notify_cpu_starting(cpu);
set_cpu_online(cpu, true);
default_idle();
return 0;
}
static struct task_struct *idle_thread(int cpu)
{
struct task_struct *new_task;
current->thread.request.u.thread.proc = idle_proc;
current->thread.request.u.thread.arg = (void *) cpu;
new_task = fork_idle(cpu);
if (IS_ERR(new_task))
panic("copy_process failed in idle_thread, error = %ld",
PTR_ERR(new_task));
cpu_tasks[cpu] = ((struct cpu_task)
{ .pid = new_task->thread.mode.tt.extern_pid,
.task = new_task } );
idle_threads[cpu] = new_task;
panic("skas mode doesn't support SMP");
return new_task;
}
void smp_prepare_cpus(unsigned int maxcpus)
{
struct task_struct *idle;
unsigned long waittime;
int err, cpu, me = smp_processor_id();
int i;
for (i = 0; i < ncpus; ++i)
set_cpu_possible(i, true);
set_cpu_online(me, true);
cpu_set(me, cpu_callin_map);
err = os_pipe(cpu_data[me].ipi_pipe, 1, 1);
if (err < 0)
panic("CPU#0 failed to create IPI pipe, errno = %d", -err);
os_set_fd_async(cpu_data[me].ipi_pipe[0]);
for (cpu = 1; cpu < ncpus; cpu++) {
printk(KERN_INFO "Booting processor %d...\n", cpu);
idle = idle_thread(cpu);
init_idle(idle, cpu);
waittime = 200000000;
while (waittime-- && !cpu_isset(cpu, cpu_callin_map))
cpu_relax();
printk(KERN_INFO "%s\n",
cpu_isset(cpu, cpu_calling_map) ? "done" : "failed");
}
}
void smp_prepare_boot_cpu(void)
{
set_cpu_online(smp_processor_id(), true);
}
int __cpu_up(unsigned int cpu, struct task_struct *tidle)
{
cpu_set(cpu, smp_commenced_mask);
while (!cpu_online(cpu))
mb();
return 0;
}
int setup_profiling_timer(unsigned int multiplier)
{
printk(KERN_INFO "setup_profiling_timer\n");
return 0;
}
void smp_call_function_slave(int cpu);
void IPI_handler(int cpu)
{
unsigned char c;
int fd;
fd = cpu_data[cpu].ipi_pipe[0];
while (os_read_file(fd, &c, 1) == 1) {
switch (c) {
case 'C':
smp_call_function_slave(cpu);
break;
case 'R':
scheduler_ipi();
break;
case 'S':
printk(KERN_INFO "CPU#%d stopping\n", cpu);
while (1)
pause();
break;
default:
printk(KERN_ERR "CPU#%d received unknown IPI [%c]!\n",
cpu, c);
break;
}
}
}
int hard_smp_processor_id(void)
{
return pid_to_processor_id(os_getpid());
}
static DEFINE_SPINLOCK(call_lock);
static atomic_t scf_started;
static atomic_t scf_finished;
static void (*func)(void *info);
static void *info;
void smp_call_function_slave(int cpu)
{
atomic_inc(&scf_started);
(*func)(info);
atomic_inc(&scf_finished);
}
int smp_call_function(void (*_func)(void *info), void *_info, int wait)
{
int cpus = num_online_cpus() - 1;
int i;
if (!cpus)
return 0;
/* Can deadlock when called with interrupts disabled */
WARN_ON(irqs_disabled());
spin_lock_bh(&call_lock);
atomic_set(&scf_started, 0);
atomic_set(&scf_finished, 0);
func = _func;
info = _info;
for_each_online_cpu(i)
os_write_file(cpu_data[i].ipi_pipe[1], "C", 1);
while (atomic_read(&scf_started) != cpus)
barrier();
if (wait)
while (atomic_read(&scf_finished) != cpus)
barrier();
spin_unlock_bh(&call_lock);
return 0;
}
#endif
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