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git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - arch/score/kernel/process.c
2 * arch/score/kernel/process.c
4 * Score Processor version.
6 * Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
7 * Chen Liqin <liqin.chen@sunplusct.com>
8 * Lennox Wu <lennox.wu@sunplusct.com>
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.
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.
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
26 #include <linux/module.h>
27 #include <linux/reboot.h>
28 #include <linux/elfcore.h>
30 #include <linux/rcupdate.h>
32 void (*pm_power_off
)(void);
33 EXPORT_SYMBOL(pm_power_off
);
35 /* If or when software machine-restart is implemented, add code here. */
36 void machine_restart(char *command
) {}
38 /* If or when software machine-halt is implemented, add code here. */
39 void machine_halt(void) {}
41 /* If or when software machine-power-off is implemented, add code here. */
42 void machine_power_off(void) {}
45 * The idle thread. There's no useful work to be
46 * done, so just try to conserve power and have a
47 * low exit latency (ie sit in a loop waiting for
48 * somebody to say that they'd like to reschedule)
50 void __noreturn
cpu_idle(void)
52 /* endless idle loop with no priority at all */
55 while (!need_resched())
58 schedule_preempt_disabled();
62 void ret_from_fork(void);
63 void ret_from_kernel_thread(void);
65 void start_thread(struct pt_regs
*regs
, unsigned long pc
, unsigned long sp
)
69 /* New thread loses kernel privileges. */
70 status
= regs
->cp0_psr
& ~(KU_MASK
);
72 regs
->cp0_psr
= status
;
77 void exit_thread(void) {}
80 * When a process does an "exec", machine state like FPU and debug
81 * registers need to be reset. This is a hook function for that.
82 * Currently we don't have any such state to reset, so this is empty.
84 void flush_thread(void) {}
87 * set up the kernel stack and exception frames for a new process
89 int copy_thread(unsigned long clone_flags
, unsigned long usp
,
90 unsigned long arg
, struct task_struct
*p
)
92 struct thread_info
*ti
= task_thread_info(p
);
93 struct pt_regs
*childregs
= task_pt_regs(p
);
94 struct pt_regs
*regs
= current_pt_regs();
96 p
->thread
.reg0
= (unsigned long) childregs
;
97 if (unlikely(p
->flags
& PF_KTHREAD
)) {
98 memset(childregs
, 0, sizeof(struct pt_regs
));
99 p
->thread
->reg12
= usp
;
100 p
->thread
->reg13
= arg
;
101 p
->thread
.reg3
= (unsigned long) ret_from_kernel_thread
;
103 *childregs
= *current_pt_regs();
104 childregs
->regs
[7] = 0; /* Clear error flag */
105 childregs
->regs
[4] = 0; /* Child gets zero as return value */
107 childregs
->regs
[0] = usp
; /* user fork */
108 p
->thread
.reg3
= (unsigned long) ret_from_fork
;
111 p
->thread
.cp0_psr
= 0;
116 /* Fill in the fpu structure for a core dump. */
117 int dump_fpu(struct pt_regs
*regs
, elf_fpregset_t
*r
)
122 unsigned long thread_saved_pc(struct task_struct
*tsk
)
124 return task_pt_regs(tsk
)->cp0_epc
;
127 unsigned long get_wchan(struct task_struct
*task
)
129 if (!task
|| task
== current
|| task
->state
== TASK_RUNNING
)
132 if (!task_stack_page(task
))
135 return task_pt_regs(task
)->cp0_epc
;
138 unsigned long arch_align_stack(unsigned long sp
)