/* MN10300 Process handling code
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/user.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/reboot.h>
#include <linux/percpu.h>
#include <linux/err.h>
#include <linux/fs.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/processor.h>
#include <asm/mmu_context.h>
#include <asm/fpu.h>
#include <asm/reset-regs.h>
#include <asm/gdb-stub.h>
#include "internal.h"
/*
* power management idle function, if any..
*/
void (*pm_idle)(void);
EXPORT_SYMBOL(pm_idle);
/*
* return saved PC of a blocked thread.
*/
unsigned long thread_saved_pc(struct task_struct *tsk)
{
return ((unsigned long *) tsk->thread.sp)[3];
}
/*
* power off function, if any
*/
void (*pm_power_off)(void);
EXPORT_SYMBOL(pm_power_off);
/*
* we use this if we don't have any better idle routine
*/
static void default_idle(void)
{
local_irq_disable();
if (!need_resched())
safe_halt();
else
local_irq_enable();
}
/*
* 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)
{
int cpu = smp_processor_id();
/* endless idle loop with no priority at all */
for (;;) {
while (!need_resched()) {
void (*idle)(void);
smp_rmb();
idle = pm_idle;
if (!idle)
idle = default_idle;
irq_stat[cpu].idle_timestamp = jiffies;
idle();
}
preempt_enable_no_resched();
schedule();
preempt_disable();
}
}
void release_segments(struct mm_struct *mm)
{
}
void machine_restart(char *cmd)
{
#ifdef CONFIG_GDBSTUB
gdbstub_exit(0);
#endif
#ifdef mn10300_unit_hard_reset
mn10300_unit_hard_reset();
#else
mn10300_proc_hard_reset();
#endif
}
void machine_halt(void)
{
#ifdef CONFIG_GDBSTUB
gdbstub_exit(0);
#endif
}
void machine_power_off(void)
{
#ifdef CONFIG_GDBSTUB
gdbstub_exit(0);
#endif
}
void show_regs(struct pt_regs *regs)
{
}
/*
* create a kernel thread
*/
int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
{
struct pt_regs regs;
memset(®s, 0, sizeof(regs));
regs.a2 = (unsigned long) fn;
regs.d2 = (unsigned long) arg;
regs.pc = (unsigned long) kernel_thread_helper;
local_save_flags(regs.epsw);
regs.epsw |= EPSW_IE | EPSW_IM_7;
/* Ok, create the new process.. */
return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0,
NULL, NULL);
}
EXPORT_SYMBOL(kernel_thread);
/*
* free current thread data structures etc..
*/
void exit_thread(void)
{
exit_fpu();
}
void flush_thread(void)
{
flush_fpu();
}
void release_thread(struct task_struct *dead_task)
{
}
/*
* we do not have to muck with descriptors here, that is
* done in switch_mm() as needed.
*/
void copy_segments(struct task_struct *p, struct mm_struct *new_mm)
{
}
/*
* this gets called before we allocate a new thread and copy the current task
* into it so that we can store lazy state into memory
*/
void prepare_to_copy(struct task_struct *tsk)
{
unlazy_fpu(tsk);
}
/*
* set up the kernel stack for a new thread and copy arch-specific thread
* control information
*/
int copy_thread(unsigned long clone_flags,
unsigned long c_usp, unsigned long ustk_size,
struct task_struct *p, struct pt_regs *kregs)
{
struct pt_regs *c_uregs, *c_kregs, *uregs;
unsigned long c_ksp;
uregs = current->thread.uregs;
c_ksp = (unsigned long) task_stack_page(p) + THREAD_SIZE;
/* allocate the userspace exception frame and set it up */
c_ksp -= sizeof(struct pt_regs);
c_uregs = (struct pt_regs *) c_ksp;
p->thread.uregs = c_uregs;
*c_uregs = *uregs;
c_uregs->sp = c_usp;
c_uregs->epsw &= ~EPSW_FE; /* my FPU */
c_ksp -= 12; /* allocate function call ABI slack */
/* the new TLS pointer is passed in as arg #5 to sys_clone() */
if (clone_flags & CLONE_SETTLS)
c_uregs->e2 = __frame->d3;
/* set up the return kernel frame if called from kernel_thread() */
c_kregs = c_uregs;
if (kregs != uregs) {
c_ksp -= sizeof(struct pt_regs);
c_kregs = (struct pt_regs *) c_ksp;
*c_kregs = *kregs;
c_kregs->sp = c_usp;
c_kregs->next = c_uregs;
#ifdef CONFIG_MN10300_CURRENT_IN_E2
c_kregs->e2 = (unsigned long) p; /* current */
#endif
c_ksp -= 12; /* allocate function call ABI slack */
}
/* set up things up so the scheduler can start the new task */
p->thread.__frame = c_kregs;
p->thread.a3 = (unsigned long) c_kregs;
p->thread.sp = c_ksp;
p->thread.pc = (unsigned long) ret_from_fork;
p->thread.wchan = (unsigned long) ret_from_fork;
p->thread.usp = c_usp;
return 0;
}
/*
* clone a process
* - tlsptr is retrieved by copy_thread() from __frame->d3
*/
asmlinkage long sys_clone(unsigned long clone_flags, unsigned long newsp,
int __user *parent_tidptr, int __user *child_tidptr,
int __user *tlsptr)
{
return do_fork(clone_flags, newsp ?: __frame->sp, __frame, 0,
parent_tidptr, child_tidptr);
}
asmlinkage long sys_fork(void)
{
return do_fork(SIGCHLD, __frame->sp, __frame, 0, NULL, NULL);
}
asmlinkage long sys_vfork(void)
{
return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, __frame->sp, __frame,
0, NULL, NULL);
}
asmlinkage long sys_execve(char __user *name,
char __user * __user *argv,
char __user * __user *envp)
{
char *filename;
int error;
filename = getname(name);
error = PTR_ERR(filename);
if (IS_ERR(filename))
return error;
error = do_execve(filename, argv, envp, __frame);
putname(filename);
return error;
}
unsigned long get_wchan(struct task_struct *p)
{
return p->thread.wchan;
}
