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