169 lines
4.3 KiB
C
169 lines
4.3 KiB
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>
|
|
|
|
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) {
|
|
while (!need_resched())
|
|
barrier();
|
|
|
|
preempt_enable_no_resched();
|
|
schedule();
|
|
preempt_disable();
|
|
}
|
|
}
|
|
|
|
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 __noreturn
|
|
kernel_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(®s, 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, ®s, 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;
|
|
}
|