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b920de1b DH |
1 | /* MN10300 Process handling code |
2 | * | |
3 | * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. | |
4 | * Written by David Howells (dhowells@redhat.com) | |
5 | * | |
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. | |
10 | */ | |
11 | #include <linux/module.h> | |
12 | #include <linux/errno.h> | |
13 | #include <linux/sched.h> | |
14 | #include <linux/kernel.h> | |
15 | #include <linux/mm.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/slab.h> | |
22 | #include <linux/user.h> | |
b920de1b DH |
23 | #include <linux/interrupt.h> |
24 | #include <linux/delay.h> | |
25 | #include <linux/reboot.h> | |
26 | #include <linux/percpu.h> | |
27 | #include <linux/err.h> | |
28 | #include <linux/fs.h> | |
29 | #include <asm/uaccess.h> | |
30 | #include <asm/pgtable.h> | |
31 | #include <asm/system.h> | |
32 | #include <asm/io.h> | |
33 | #include <asm/processor.h> | |
34 | #include <asm/mmu_context.h> | |
35 | #include <asm/fpu.h> | |
36 | #include <asm/reset-regs.h> | |
37 | #include <asm/gdb-stub.h> | |
38 | #include "internal.h" | |
39 | ||
40 | /* | |
41 | * power management idle function, if any.. | |
42 | */ | |
43 | void (*pm_idle)(void); | |
44 | EXPORT_SYMBOL(pm_idle); | |
45 | ||
46 | /* | |
47 | * return saved PC of a blocked thread. | |
48 | */ | |
49 | unsigned long thread_saved_pc(struct task_struct *tsk) | |
50 | { | |
51 | return ((unsigned long *) tsk->thread.sp)[3]; | |
52 | } | |
53 | ||
54 | /* | |
55 | * power off function, if any | |
56 | */ | |
57 | void (*pm_power_off)(void); | |
58 | EXPORT_SYMBOL(pm_power_off); | |
59 | ||
60 | /* | |
61 | * we use this if we don't have any better idle routine | |
62 | */ | |
63 | static void default_idle(void) | |
64 | { | |
65 | local_irq_disable(); | |
66 | if (!need_resched()) | |
67 | safe_halt(); | |
68 | else | |
69 | local_irq_enable(); | |
70 | } | |
71 | ||
72 | /* | |
73 | * the idle thread | |
74 | * - there's no useful work to be done, so just try to conserve power and have | |
75 | * a low exit latency (ie sit in a loop waiting for somebody to say that | |
76 | * they'd like to reschedule) | |
77 | */ | |
78 | void cpu_idle(void) | |
79 | { | |
80 | int cpu = smp_processor_id(); | |
81 | ||
82 | /* endless idle loop with no priority at all */ | |
83 | for (;;) { | |
84 | while (!need_resched()) { | |
85 | void (*idle)(void); | |
86 | ||
87 | smp_rmb(); | |
88 | idle = pm_idle; | |
89 | if (!idle) | |
90 | idle = default_idle; | |
91 | ||
92 | irq_stat[cpu].idle_timestamp = jiffies; | |
93 | idle(); | |
94 | } | |
95 | ||
96 | preempt_enable_no_resched(); | |
97 | schedule(); | |
98 | preempt_disable(); | |
99 | } | |
100 | } | |
101 | ||
102 | void release_segments(struct mm_struct *mm) | |
103 | { | |
104 | } | |
105 | ||
106 | void machine_restart(char *cmd) | |
107 | { | |
108 | #ifdef CONFIG_GDBSTUB | |
109 | gdbstub_exit(0); | |
110 | #endif | |
111 | ||
112 | #ifdef mn10300_unit_hard_reset | |
113 | mn10300_unit_hard_reset(); | |
114 | #else | |
115 | mn10300_proc_hard_reset(); | |
116 | #endif | |
117 | } | |
118 | ||
119 | void machine_halt(void) | |
120 | { | |
121 | #ifdef CONFIG_GDBSTUB | |
122 | gdbstub_exit(0); | |
123 | #endif | |
124 | } | |
125 | ||
126 | void machine_power_off(void) | |
127 | { | |
128 | #ifdef CONFIG_GDBSTUB | |
129 | gdbstub_exit(0); | |
130 | #endif | |
131 | } | |
132 | ||
133 | void show_regs(struct pt_regs *regs) | |
134 | { | |
135 | } | |
136 | ||
137 | /* | |
138 | * create a kernel thread | |
139 | */ | |
140 | int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) | |
141 | { | |
142 | struct pt_regs regs; | |
143 | ||
144 | memset(®s, 0, sizeof(regs)); | |
145 | ||
146 | regs.a2 = (unsigned long) fn; | |
147 | regs.d2 = (unsigned long) arg; | |
148 | regs.pc = (unsigned long) kernel_thread_helper; | |
149 | local_save_flags(regs.epsw); | |
150 | regs.epsw |= EPSW_IE | EPSW_IM_7; | |
151 | ||
152 | /* Ok, create the new process.. */ | |
153 | return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0, | |
154 | NULL, NULL); | |
155 | } | |
156 | ||
157 | /* | |
158 | * free current thread data structures etc.. | |
159 | */ | |
160 | void exit_thread(void) | |
161 | { | |
162 | exit_fpu(); | |
163 | } | |
164 | ||
165 | void flush_thread(void) | |
166 | { | |
167 | flush_fpu(); | |
168 | } | |
169 | ||
170 | void release_thread(struct task_struct *dead_task) | |
171 | { | |
172 | } | |
173 | ||
174 | /* | |
175 | * we do not have to muck with descriptors here, that is | |
176 | * done in switch_mm() as needed. | |
177 | */ | |
178 | void copy_segments(struct task_struct *p, struct mm_struct *new_mm) | |
179 | { | |
180 | } | |
181 | ||
182 | /* | |
183 | * this gets called before we allocate a new thread and copy the current task | |
184 | * into it so that we can store lazy state into memory | |
185 | */ | |
186 | void prepare_to_copy(struct task_struct *tsk) | |
187 | { | |
188 | unlazy_fpu(tsk); | |
189 | } | |
190 | ||
191 | /* | |
192 | * set up the kernel stack for a new thread and copy arch-specific thread | |
193 | * control information | |
194 | */ | |
195 | int copy_thread(int nr, unsigned long clone_flags, | |
196 | unsigned long c_usp, unsigned long ustk_size, | |
197 | struct task_struct *p, struct pt_regs *kregs) | |
198 | { | |
199 | struct pt_regs *c_uregs, *c_kregs, *uregs; | |
200 | unsigned long c_ksp; | |
201 | ||
202 | uregs = current->thread.uregs; | |
203 | ||
204 | c_ksp = (unsigned long) task_stack_page(p) + THREAD_SIZE; | |
205 | ||
206 | /* allocate the userspace exception frame and set it up */ | |
207 | c_ksp -= sizeof(struct pt_regs); | |
208 | c_uregs = (struct pt_regs *) c_ksp; | |
209 | ||
210 | p->thread.uregs = c_uregs; | |
211 | *c_uregs = *uregs; | |
212 | c_uregs->sp = c_usp; | |
213 | c_uregs->epsw &= ~EPSW_FE; /* my FPU */ | |
214 | ||
215 | c_ksp -= 12; /* allocate function call ABI slack */ | |
216 | ||
217 | /* the new TLS pointer is passed in as arg #5 to sys_clone() */ | |
218 | if (clone_flags & CLONE_SETTLS) | |
219 | c_uregs->e2 = __frame->d3; | |
220 | ||
221 | /* set up the return kernel frame if called from kernel_thread() */ | |
222 | c_kregs = c_uregs; | |
223 | if (kregs != uregs) { | |
224 | c_ksp -= sizeof(struct pt_regs); | |
225 | c_kregs = (struct pt_regs *) c_ksp; | |
226 | *c_kregs = *kregs; | |
227 | c_kregs->sp = c_usp; | |
228 | c_kregs->next = c_uregs; | |
229 | #ifdef CONFIG_MN10300_CURRENT_IN_E2 | |
230 | c_kregs->e2 = (unsigned long) p; /* current */ | |
231 | #endif | |
232 | ||
233 | c_ksp -= 12; /* allocate function call ABI slack */ | |
234 | } | |
235 | ||
236 | /* set up things up so the scheduler can start the new task */ | |
237 | p->thread.__frame = c_kregs; | |
238 | p->thread.a3 = (unsigned long) c_kregs; | |
239 | p->thread.sp = c_ksp; | |
240 | p->thread.pc = (unsigned long) ret_from_fork; | |
241 | p->thread.wchan = (unsigned long) ret_from_fork; | |
242 | p->thread.usp = c_usp; | |
243 | ||
244 | return 0; | |
245 | } | |
246 | ||
247 | /* | |
248 | * clone a process | |
249 | * - tlsptr is retrieved by copy_thread() from __frame->d3 | |
250 | */ | |
251 | asmlinkage long sys_clone(unsigned long clone_flags, unsigned long newsp, | |
252 | int __user *parent_tidptr, int __user *child_tidptr, | |
253 | int __user *tlsptr) | |
254 | { | |
255 | return do_fork(clone_flags, newsp ?: __frame->sp, __frame, 0, | |
256 | parent_tidptr, child_tidptr); | |
257 | } | |
258 | ||
259 | asmlinkage long sys_fork(void) | |
260 | { | |
261 | return do_fork(SIGCHLD, __frame->sp, __frame, 0, NULL, NULL); | |
262 | } | |
263 | ||
264 | asmlinkage long sys_vfork(void) | |
265 | { | |
266 | return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, __frame->sp, __frame, | |
267 | 0, NULL, NULL); | |
268 | } | |
269 | ||
270 | asmlinkage long sys_execve(char __user *name, | |
271 | char __user * __user *argv, | |
272 | char __user * __user *envp) | |
273 | { | |
274 | char *filename; | |
275 | int error; | |
276 | ||
277 | lock_kernel(); | |
278 | ||
279 | filename = getname(name); | |
280 | error = PTR_ERR(filename); | |
281 | if (!IS_ERR(filename)) { | |
282 | error = do_execve(filename, argv, envp, __frame); | |
283 | if (error == 0) | |
284 | current->ptrace &= ~PT_DTRACE; | |
285 | ||
286 | putname(filename); | |
287 | } | |
288 | ||
289 | unlock_kernel(); | |
290 | return error; | |
291 | } | |
292 | ||
293 | unsigned long get_wchan(struct task_struct *p) | |
294 | { | |
295 | return p->thread.wchan; | |
296 | } |