blob: b609f63f15909849a48240174e80a3e9b9d87b5b [file] [log] [blame]
/*
* linux/arch/h8300/kernel/process.c
*
* Yoshinori Sato <ysato@users.sourceforge.jp>
*
* Based on:
*
* linux/arch/m68knommu/kernel/process.c
*
* Copyright (C) 1998 D. Jeff Dionne <jeff@ryeham.ee.ryerson.ca>,
* Kenneth Albanowski <kjahds@kjahds.com>,
* The Silver Hammer Group, Ltd.
*
* linux/arch/m68k/kernel/process.c
*
* Copyright (C) 1995 Hamish Macdonald
*
* 68060 fixes by Jesper Skov
*/
/*
* This file handles the architecture-dependent parts of process handling..
*/
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/interrupt.h>
#include <linux/reboot.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/rcupdate.h>
#include <asm/uaccess.h>
#include <asm/traps.h>
#include <asm/setup.h>
#include <asm/pgtable.h>
void (*pm_power_off)(void) = NULL;
EXPORT_SYMBOL(pm_power_off);
asmlinkage void ret_from_fork(void);
asmlinkage void ret_from_kernel_thread(void);
/*
* The idle loop on an H8/300..
*/
#if !defined(CONFIG_H8300H_SIM) && !defined(CONFIG_H8S_SIM)
static void default_idle(void)
{
local_irq_disable();
if (!need_resched()) {
local_irq_enable();
/* XXX: race here! What if need_resched() gets set now? */
__asm__("sleep");
} else
local_irq_enable();
}
#else
static void default_idle(void)
{
cpu_relax();
}
#endif
void (*idle)(void) = default_idle;
/*
* The idle thread. There's no useful work to be
* done, so just try to conserve power and have a
* low exit latency (ie sit in a loop waiting for
* somebody to say that they'd like to reschedule)
*/
void cpu_idle(void)
{
while (1) {
rcu_idle_enter();
while (!need_resched())
idle();
rcu_idle_exit();
schedule_preempt_disabled();
}
}
void machine_restart(char * __unused)
{
local_irq_disable();
__asm__("jmp @@0");
}
void machine_halt(void)
{
local_irq_disable();
__asm__("sleep");
for (;;);
}
void machine_power_off(void)
{
local_irq_disable();
__asm__("sleep");
for (;;);
}
void show_regs(struct pt_regs * regs)
{
printk("\nPC: %08lx Status: %02x",
regs->pc, regs->ccr);
printk("\nORIG_ER0: %08lx ER0: %08lx ER1: %08lx",
regs->orig_er0, regs->er0, regs->er1);
printk("\nER2: %08lx ER3: %08lx ER4: %08lx ER5: %08lx",
regs->er2, regs->er3, regs->er4, regs->er5);
printk("\nER6' %08lx ",regs->er6);
if (user_mode(regs))
printk("USP: %08lx\n", rdusp());
else
printk("\n");
}
void flush_thread(void)
{
}
int copy_thread(unsigned long clone_flags,
unsigned long usp, unsigned long topstk,
struct task_struct * p)
{
struct pt_regs * childregs;
childregs = (struct pt_regs *) (THREAD_SIZE + task_stack_page(p)) - 1;
if (unlikely(p->flags & PF_KTHREAD)) {
memset(childregs, 0, sizeof(struct pt_regs));
childregs->retpc = (unsigned long) ret_from_kernel_thread;
childregs->er4 = topstk; /* arg */
childregs->er5 = usp; /* fn */
p->thread.ksp = (unsigned long)childregs;
}
*childregs = *current_pt_regs();
childregs->retpc = (unsigned long) ret_from_fork;
childregs->er0 = 0;
p->thread.usp = usp ?: rdusp();
p->thread.ksp = (unsigned long)childregs;
return 0;
}
unsigned long thread_saved_pc(struct task_struct *tsk)
{
return ((struct pt_regs *)tsk->thread.esp0)->pc;
}
unsigned long get_wchan(struct task_struct *p)
{
unsigned long fp, pc;
unsigned long stack_page;
int count = 0;
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
stack_page = (unsigned long)p;
fp = ((struct pt_regs *)p->thread.ksp)->er6;
do {
if (fp < stack_page+sizeof(struct thread_info) ||
fp >= 8184+stack_page)
return 0;
pc = ((unsigned long *)fp)[1];
if (!in_sched_functions(pc))
return pc;
fp = *(unsigned long *) fp;
} while (count++ < 16);
return 0;
}