swh:1:snp:c3bf2749e3476071fa748f67b0ffa2fdc5fe49d9
Tip revision: 569dbb88e80deb68974ef6fdd6a13edb9d686261 authored by Linus Torvalds on 03 September 2017, 20:56:17 UTC
Linux 4.13
Linux 4.13
Tip revision: 569dbb8
process.c
/*
* arch/score/kernel/process.c
*
* Score Processor version.
*
* Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
* Chen Liqin <liqin.chen@sunplusct.com>
* Lennox Wu <lennox.wu@sunplusct.com>
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see the file COPYING, or write
* to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <linux/module.h>
#include <linux/reboot.h>
#include <linux/elfcore.h>
#include <linux/pm.h>
#include <linux/rcupdate.h>
#include <linux/sched/task.h>
#include <linux/sched/task_stack.h>
void (*pm_power_off)(void);
EXPORT_SYMBOL(pm_power_off);
/* If or when software machine-restart is implemented, add code here. */
void machine_restart(char *command) {}
/* If or when software machine-halt is implemented, add code here. */
void machine_halt(void) {}
/* If or when software machine-power-off is implemented, add code here. */
void machine_power_off(void) {}
void ret_from_fork(void);
void ret_from_kernel_thread(void);
void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp)
{
unsigned long status;
/* New thread loses kernel privileges. */
status = regs->cp0_psr & ~(KU_MASK);
status |= KU_USER;
regs->cp0_psr = status;
regs->cp0_epc = pc;
regs->regs[0] = sp;
}
/*
* When a process does an "exec", machine state like FPU and debug
* registers need to be reset. This is a hook function for that.
* Currently we don't have any such state to reset, so this is empty.
*/
void flush_thread(void) {}
/*
* set up the kernel stack and exception frames for a new process
*/
int copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long arg, struct task_struct *p)
{
struct thread_info *ti = task_thread_info(p);
struct pt_regs *childregs = task_pt_regs(p);
struct pt_regs *regs = current_pt_regs();
p->thread.reg0 = (unsigned long) childregs;
if (unlikely(p->flags & PF_KTHREAD)) {
memset(childregs, 0, sizeof(struct pt_regs));
p->thread.reg12 = usp;
p->thread.reg13 = arg;
p->thread.reg3 = (unsigned long) ret_from_kernel_thread;
} else {
*childregs = *current_pt_regs();
childregs->regs[7] = 0; /* Clear error flag */
childregs->regs[4] = 0; /* Child gets zero as return value */
if (usp)
childregs->regs[0] = usp; /* user fork */
p->thread.reg3 = (unsigned long) ret_from_fork;
}
p->thread.cp0_psr = 0;
return 0;
}
/* Fill in the fpu structure for a core dump. */
int dump_fpu(struct pt_regs *regs, elf_fpregset_t *r)
{
return 1;
}
unsigned long get_wchan(struct task_struct *task)
{
if (!task || task == current || task->state == TASK_RUNNING)
return 0;
if (!task_stack_page(task))
return 0;
return task_pt_regs(task)->cp0_epc;
}
unsigned long arch_align_stack(unsigned long sp)
{
return sp;
}