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git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - arch/mn10300/kernel/process.c
1 /* MN10300 Process handling code
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
11 #include <linux/module.h>
12 #include <linux/errno.h>
13 #include <linux/sched.h>
14 #include <linux/kernel.h>
16 #include <linux/smp.h>
17 #include <linux/smp_lock.h>
18 #include <linux/stddef.h>
19 #include <linux/unistd.h>
20 #include <linux/ptrace.h>
21 #include <linux/user.h>
22 #include <linux/interrupt.h>
23 #include <linux/delay.h>
24 #include <linux/reboot.h>
25 #include <linux/percpu.h>
26 #include <linux/err.h>
28 #include <linux/slab.h>
29 #include <asm/uaccess.h>
30 #include <asm/pgtable.h>
31 #include <asm/system.h>
33 #include <asm/processor.h>
34 #include <asm/mmu_context.h>
36 #include <asm/reset-regs.h>
37 #include <asm/gdb-stub.h>
41 * power management idle function, if any..
43 void (*pm_idle
)(void);
44 EXPORT_SYMBOL(pm_idle
);
47 * return saved PC of a blocked thread.
49 unsigned long thread_saved_pc(struct task_struct
*tsk
)
51 return ((unsigned long *) tsk
->thread
.sp
)[3];
55 * power off function, if any
57 void (*pm_power_off
)(void);
58 EXPORT_SYMBOL(pm_power_off
);
60 #if !defined(CONFIG_SMP) || defined(CONFIG_HOTPLUG_CPU)
62 * we use this if we don't have any better idle routine
64 static void default_idle(void)
73 #else /* !CONFIG_SMP || CONFIG_HOTPLUG_CPU */
75 * On SMP it's slightly faster (but much more power-consuming!)
76 * to poll the ->work.need_resched flag instead of waiting for the
77 * cross-CPU IPI to arrive. Use this option with caution.
79 static inline void poll_idle(void)
86 * Deal with another CPU just having chosen a thread to
89 oldval
= test_and_clear_thread_flag(TIF_NEED_RESCHED
);
92 set_thread_flag(TIF_POLLING_NRFLAG
);
93 while (!need_resched())
95 clear_thread_flag(TIF_POLLING_NRFLAG
);
100 #endif /* !CONFIG_SMP || CONFIG_HOTPLUG_CPU */
104 * - there's no useful work to be done, so just try to conserve power and have
105 * a low exit latency (ie sit in a loop waiting for somebody to say that
106 * they'd like to reschedule)
110 /* endless idle loop with no priority at all */
112 while (!need_resched()) {
118 #if defined(CONFIG_SMP) && !defined(CONFIG_HOTPLUG_CPU)
120 #else /* CONFIG_SMP && !CONFIG_HOTPLUG_CPU */
122 #endif /* CONFIG_SMP && !CONFIG_HOTPLUG_CPU */
127 preempt_enable_no_resched();
133 void release_segments(struct mm_struct
*mm
)
137 void machine_restart(char *cmd
)
139 #ifdef CONFIG_GDBSTUB
143 #ifdef mn10300_unit_hard_reset
144 mn10300_unit_hard_reset();
146 mn10300_proc_hard_reset();
150 void machine_halt(void)
152 #ifdef CONFIG_GDBSTUB
157 void machine_power_off(void)
159 #ifdef CONFIG_GDBSTUB
164 void show_regs(struct pt_regs
*regs
)
169 * create a kernel thread
171 int kernel_thread(int (*fn
)(void *), void *arg
, unsigned long flags
)
175 memset(®s
, 0, sizeof(regs
));
177 regs
.a2
= (unsigned long) fn
;
178 regs
.d2
= (unsigned long) arg
;
179 regs
.pc
= (unsigned long) kernel_thread_helper
;
180 local_save_flags(regs
.epsw
);
181 regs
.epsw
|= EPSW_IE
| EPSW_IM_7
;
183 /* Ok, create the new process.. */
184 return do_fork(flags
| CLONE_VM
| CLONE_UNTRACED
, 0, ®s
, 0,
187 EXPORT_SYMBOL(kernel_thread
);
190 * free current thread data structures etc..
192 void exit_thread(void)
197 void flush_thread(void)
202 void release_thread(struct task_struct
*dead_task
)
207 * we do not have to muck with descriptors here, that is
208 * done in switch_mm() as needed.
210 void copy_segments(struct task_struct
*p
, struct mm_struct
*new_mm
)
215 * this gets called before we allocate a new thread and copy the current task
216 * into it so that we can store lazy state into memory
218 void prepare_to_copy(struct task_struct
*tsk
)
224 * set up the kernel stack for a new thread and copy arch-specific thread
225 * control information
227 int copy_thread(unsigned long clone_flags
,
228 unsigned long c_usp
, unsigned long ustk_size
,
229 struct task_struct
*p
, struct pt_regs
*kregs
)
231 struct thread_info
*ti
= task_thread_info(p
);
232 struct pt_regs
*c_uregs
, *c_kregs
, *uregs
;
235 uregs
= current
->thread
.uregs
;
237 c_ksp
= (unsigned long) task_stack_page(p
) + THREAD_SIZE
;
239 /* allocate the userspace exception frame and set it up */
240 c_ksp
-= sizeof(struct pt_regs
);
241 c_uregs
= (struct pt_regs
*) c_ksp
;
243 p
->thread
.uregs
= c_uregs
;
246 c_uregs
->epsw
&= ~EPSW_FE
; /* my FPU */
248 c_ksp
-= 12; /* allocate function call ABI slack */
250 /* the new TLS pointer is passed in as arg #5 to sys_clone() */
251 if (clone_flags
& CLONE_SETTLS
)
252 c_uregs
->e2
= current_frame()->d3
;
254 /* set up the return kernel frame if called from kernel_thread() */
256 if (kregs
!= uregs
) {
257 c_ksp
-= sizeof(struct pt_regs
);
258 c_kregs
= (struct pt_regs
*) c_ksp
;
261 c_kregs
->next
= c_uregs
;
262 #ifdef CONFIG_MN10300_CURRENT_IN_E2
263 c_kregs
->e2
= (unsigned long) p
; /* current */
266 c_ksp
-= 12; /* allocate function call ABI slack */
269 /* set up things up so the scheduler can start the new task */
271 p
->thread
.a3
= (unsigned long) c_kregs
;
272 p
->thread
.sp
= c_ksp
;
273 p
->thread
.pc
= (unsigned long) ret_from_fork
;
274 p
->thread
.wchan
= (unsigned long) ret_from_fork
;
275 p
->thread
.usp
= c_usp
;
282 * - tlsptr is retrieved by copy_thread() from current_frame()->d3
284 asmlinkage
long sys_clone(unsigned long clone_flags
, unsigned long newsp
,
285 int __user
*parent_tidptr
, int __user
*child_tidptr
,
288 return do_fork(clone_flags
, newsp
?: current_frame()->sp
,
289 current_frame(), 0, parent_tidptr
, child_tidptr
);
292 asmlinkage
long sys_fork(void)
294 return do_fork(SIGCHLD
, current_frame()->sp
,
295 current_frame(), 0, NULL
, NULL
);
298 asmlinkage
long sys_vfork(void)
300 return do_fork(CLONE_VFORK
| CLONE_VM
| SIGCHLD
, current_frame()->sp
,
301 current_frame(), 0, NULL
, NULL
);
304 asmlinkage
long sys_execve(const char __user
*name
,
305 const char __user
*const __user
*argv
,
306 const char __user
*const __user
*envp
)
311 filename
= getname(name
);
312 error
= PTR_ERR(filename
);
313 if (IS_ERR(filename
))
315 error
= do_execve(filename
, argv
, envp
, current_frame());
320 unsigned long get_wchan(struct task_struct
*p
)
322 return p
->thread
.wchan
;