/* * 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> 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) {} /* * 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 __noreturn cpu_idle(void){	/* endless idle loop with no priority at all */	while (1) {		rcu_idle_enter();		while (!need_resched())			barrier();		rcu_idle_exit();		schedule_preempt_disabled();	}} void ret_from_fork(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;} void exit_thread(void) {} /* * 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 unused,		struct task_struct *p, struct pt_regs *regs){	struct thread_info *ti = task_thread_info(p);	struct pt_regs *childregs = task_pt_regs(p); 	p->set_child_tid = NULL;	p->clear_child_tid = NULL; 	*childregs = *regs;	childregs->regs[7] = 0;		/* Clear error flag */	childregs->regs[4] = 0;		/* Child gets zero as return value */	regs->regs[4] = p->pid; 	if (childregs->cp0_psr & 0x8) {	/* test kernel fork or user fork */		childregs->regs[0] = usp;		/* user fork */	} else {		childregs->regs[28] = (unsigned long) ti; /* kernel fork */		childregs->regs[0] = (unsigned long) childregs;	} 	p->thread.reg0 = (unsigned long) childregs;	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;} static void __noreturnkernel_thread_helper(void *unused0, int (*fn)(void *),		 void *arg, void *unused1){	do_exit(fn(arg));} /* * Create a kernel thread. */long kernel_thread(int (*fn)(void *), void *arg, unsigned long flags){	struct pt_regs regs; 	memset(&regs, 0, sizeof(regs)); 	regs.regs[6] = (unsigned long) arg;	regs.regs[5] = (unsigned long) fn;	regs.cp0_epc = (unsigned long) kernel_thread_helper;	regs.cp0_psr = (regs.cp0_psr & ~(0x1|0x4|0x8)) | \			((regs.cp0_psr & 0x3) << 2); 	return do_fork(flags | CLONE_VM | CLONE_UNTRACED, \			0, &regs, 0, NULL, NULL);} unsigned long thread_saved_pc(struct task_struct *tsk){	return task_pt_regs(tsk)->cp0_epc;} 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;}