diff options
Diffstat (limited to 'arch/score/kernel/process.c')
| -rw-r--r-- | arch/score/kernel/process.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/arch/score/kernel/process.c b/arch/score/kernel/process.c new file mode 100644 index 00000000..25d08030 --- /dev/null +++ b/arch/score/kernel/process.c @@ -0,0 +1,168 @@ +/* + * 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; +} |