1 /* 2 * arch/score/kernel/process.c 3 * 4 * Score Processor version. 5 * 6 * Copyright (C) 2009 Sunplus Core Technology Co., Ltd. 7 * Chen Liqin <liqin.chen@sunplusct.com> 8 * Lennox Wu <lennox.wu@sunplusct.com> 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License as published by 12 * the Free Software Foundation; either version 2 of the License, or 13 * (at your option) any later version. 14 * 15 * This program is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 * GNU General Public License for more details. 19 * 20 * You should have received a copy of the GNU General Public License 21 * along with this program; if not, see the file COPYING, or write 22 * to the Free Software Foundation, Inc., 23 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 24 */ 25 26 #include <linux/module.h> 27 #include <linux/reboot.h> 28 #include <linux/elfcore.h> 29 #include <linux/pm.h> 30 #include <linux/rcupdate.h> 31 32 void (*pm_power_off)(void); 33 EXPORT_SYMBOL(pm_power_off); 34 35 /* If or when software machine-restart is implemented, add code here. */ machine_restart(char * command)36 void machine_restart(char *command) {} 37 38 /* If or when software machine-halt is implemented, add code here. */ machine_halt(void)39 void machine_halt(void) {} 40 41 /* If or when software machine-power-off is implemented, add code here. */ machine_power_off(void)42 void machine_power_off(void) {} 43 44 void ret_from_fork(void); 45 void ret_from_kernel_thread(void); 46 start_thread(struct pt_regs * regs,unsigned long pc,unsigned long sp)47 void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp) 48 { 49 unsigned long status; 50 51 /* New thread loses kernel privileges. */ 52 status = regs->cp0_psr & ~(KU_MASK); 53 status |= KU_USER; 54 regs->cp0_psr = status; 55 regs->cp0_epc = pc; 56 regs->regs[0] = sp; 57 } 58 59 /* 60 * When a process does an "exec", machine state like FPU and debug 61 * registers need to be reset. This is a hook function for that. 62 * Currently we don't have any such state to reset, so this is empty. 63 */ flush_thread(void)64 void flush_thread(void) {} 65 66 /* 67 * set up the kernel stack and exception frames for a new process 68 */ copy_thread(unsigned long clone_flags,unsigned long usp,unsigned long arg,struct task_struct * p)69 int copy_thread(unsigned long clone_flags, unsigned long usp, 70 unsigned long arg, struct task_struct *p) 71 { 72 struct thread_info *ti = task_thread_info(p); 73 struct pt_regs *childregs = task_pt_regs(p); 74 struct pt_regs *regs = current_pt_regs(); 75 76 p->thread.reg0 = (unsigned long) childregs; 77 if (unlikely(p->flags & PF_KTHREAD)) { 78 memset(childregs, 0, sizeof(struct pt_regs)); 79 p->thread.reg12 = usp; 80 p->thread.reg13 = arg; 81 p->thread.reg3 = (unsigned long) ret_from_kernel_thread; 82 } else { 83 *childregs = *current_pt_regs(); 84 childregs->regs[7] = 0; /* Clear error flag */ 85 childregs->regs[4] = 0; /* Child gets zero as return value */ 86 if (usp) 87 childregs->regs[0] = usp; /* user fork */ 88 p->thread.reg3 = (unsigned long) ret_from_fork; 89 } 90 91 p->thread.cp0_psr = 0; 92 93 return 0; 94 } 95 96 /* Fill in the fpu structure for a core dump. */ dump_fpu(struct pt_regs * regs,elf_fpregset_t * r)97 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *r) 98 { 99 return 1; 100 } 101 thread_saved_pc(struct task_struct * tsk)102 unsigned long thread_saved_pc(struct task_struct *tsk) 103 { 104 return task_pt_regs(tsk)->cp0_epc; 105 } 106 get_wchan(struct task_struct * task)107 unsigned long get_wchan(struct task_struct *task) 108 { 109 if (!task || task == current || task->state == TASK_RUNNING) 110 return 0; 111 112 if (!task_stack_page(task)) 113 return 0; 114 115 return task_pt_regs(task)->cp0_epc; 116 } 117 arch_align_stack(unsigned long sp)118 unsigned long arch_align_stack(unsigned long sp) 119 { 120 return sp; 121 } 122