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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> | |
b920de1b DH |
17 | #include <linux/stddef.h> |
18 | #include <linux/unistd.h> | |
19 | #include <linux/ptrace.h> | |
b920de1b | 20 | #include <linux/user.h> |
b920de1b DH |
21 | #include <linux/interrupt.h> |
22 | #include <linux/delay.h> | |
23 | #include <linux/reboot.h> | |
24 | #include <linux/percpu.h> | |
25 | #include <linux/err.h> | |
26 | #include <linux/fs.h> | |
5a0e3ad6 | 27 | #include <linux/slab.h> |
b920de1b DH |
28 | #include <asm/uaccess.h> |
29 | #include <asm/pgtable.h> | |
30 | #include <asm/system.h> | |
31 | #include <asm/io.h> | |
32 | #include <asm/processor.h> | |
33 | #include <asm/mmu_context.h> | |
34 | #include <asm/fpu.h> | |
35 | #include <asm/reset-regs.h> | |
36 | #include <asm/gdb-stub.h> | |
37 | #include "internal.h" | |
38 | ||
39 | /* | |
40 | * power management idle function, if any.. | |
41 | */ | |
42 | void (*pm_idle)(void); | |
43 | EXPORT_SYMBOL(pm_idle); | |
44 | ||
45 | /* | |
46 | * return saved PC of a blocked thread. | |
47 | */ | |
48 | unsigned long thread_saved_pc(struct task_struct *tsk) | |
49 | { | |
50 | return ((unsigned long *) tsk->thread.sp)[3]; | |
51 | } | |
52 | ||
53 | /* | |
54 | * power off function, if any | |
55 | */ | |
56 | void (*pm_power_off)(void); | |
57 | EXPORT_SYMBOL(pm_power_off); | |
58 | ||
368dd5ac | 59 | #if !defined(CONFIG_SMP) || defined(CONFIG_HOTPLUG_CPU) |
b920de1b DH |
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 | ||
368dd5ac AT |
72 | #else /* !CONFIG_SMP || CONFIG_HOTPLUG_CPU */ |
73 | /* | |
74 | * On SMP it's slightly faster (but much more power-consuming!) | |
75 | * to poll the ->work.need_resched flag instead of waiting for the | |
76 | * cross-CPU IPI to arrive. Use this option with caution. | |
77 | */ | |
78 | static inline void poll_idle(void) | |
79 | { | |
80 | int oldval; | |
81 | ||
82 | local_irq_enable(); | |
83 | ||
84 | /* | |
85 | * Deal with another CPU just having chosen a thread to | |
86 | * run here: | |
87 | */ | |
88 | oldval = test_and_clear_thread_flag(TIF_NEED_RESCHED); | |
89 | ||
90 | if (!oldval) { | |
91 | set_thread_flag(TIF_POLLING_NRFLAG); | |
92 | while (!need_resched()) | |
93 | cpu_relax(); | |
94 | clear_thread_flag(TIF_POLLING_NRFLAG); | |
95 | } else { | |
96 | set_need_resched(); | |
97 | } | |
98 | } | |
99 | #endif /* !CONFIG_SMP || CONFIG_HOTPLUG_CPU */ | |
100 | ||
b920de1b DH |
101 | /* |
102 | * the idle thread | |
103 | * - there's no useful work to be done, so just try to conserve power and have | |
104 | * a low exit latency (ie sit in a loop waiting for somebody to say that | |
105 | * they'd like to reschedule) | |
106 | */ | |
107 | void cpu_idle(void) | |
108 | { | |
b920de1b DH |
109 | /* endless idle loop with no priority at all */ |
110 | for (;;) { | |
111 | while (!need_resched()) { | |
112 | void (*idle)(void); | |
113 | ||
114 | smp_rmb(); | |
115 | idle = pm_idle; | |
368dd5ac AT |
116 | if (!idle) { |
117 | #if defined(CONFIG_SMP) && !defined(CONFIG_HOTPLUG_CPU) | |
118 | idle = poll_idle; | |
119 | #else /* CONFIG_SMP && !CONFIG_HOTPLUG_CPU */ | |
b920de1b | 120 | idle = default_idle; |
368dd5ac AT |
121 | #endif /* CONFIG_SMP && !CONFIG_HOTPLUG_CPU */ |
122 | } | |
b920de1b DH |
123 | idle(); |
124 | } | |
125 | ||
bd2f5536 | 126 | schedule_preempt_disabled(); |
b920de1b DH |
127 | } |
128 | } | |
129 | ||
130 | void release_segments(struct mm_struct *mm) | |
131 | { | |
132 | } | |
133 | ||
134 | void machine_restart(char *cmd) | |
135 | { | |
044264bb | 136 | #ifdef CONFIG_KERNEL_DEBUGGER |
b920de1b DH |
137 | gdbstub_exit(0); |
138 | #endif | |
139 | ||
140 | #ifdef mn10300_unit_hard_reset | |
141 | mn10300_unit_hard_reset(); | |
142 | #else | |
143 | mn10300_proc_hard_reset(); | |
144 | #endif | |
145 | } | |
146 | ||
147 | void machine_halt(void) | |
148 | { | |
044264bb | 149 | #ifdef CONFIG_KERNEL_DEBUGGER |
b920de1b DH |
150 | gdbstub_exit(0); |
151 | #endif | |
152 | } | |
153 | ||
154 | void machine_power_off(void) | |
155 | { | |
044264bb | 156 | #ifdef CONFIG_KERNEL_DEBUGGER |
b920de1b DH |
157 | gdbstub_exit(0); |
158 | #endif | |
159 | } | |
160 | ||
161 | void show_regs(struct pt_regs *regs) | |
162 | { | |
163 | } | |
164 | ||
165 | /* | |
166 | * create a kernel thread | |
167 | */ | |
168 | int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) | |
169 | { | |
170 | struct pt_regs regs; | |
171 | ||
172 | memset(®s, 0, sizeof(regs)); | |
173 | ||
174 | regs.a2 = (unsigned long) fn; | |
175 | regs.d2 = (unsigned long) arg; | |
176 | regs.pc = (unsigned long) kernel_thread_helper; | |
177 | local_save_flags(regs.epsw); | |
178 | regs.epsw |= EPSW_IE | EPSW_IM_7; | |
179 | ||
180 | /* Ok, create the new process.. */ | |
181 | return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0, | |
182 | NULL, NULL); | |
183 | } | |
7fc7228c | 184 | EXPORT_SYMBOL(kernel_thread); |
b920de1b DH |
185 | |
186 | /* | |
187 | * free current thread data structures etc.. | |
188 | */ | |
189 | void exit_thread(void) | |
190 | { | |
191 | exit_fpu(); | |
192 | } | |
193 | ||
194 | void flush_thread(void) | |
195 | { | |
196 | flush_fpu(); | |
197 | } | |
198 | ||
199 | void release_thread(struct task_struct *dead_task) | |
200 | { | |
201 | } | |
202 | ||
203 | /* | |
204 | * we do not have to muck with descriptors here, that is | |
205 | * done in switch_mm() as needed. | |
206 | */ | |
207 | void copy_segments(struct task_struct *p, struct mm_struct *new_mm) | |
208 | { | |
209 | } | |
210 | ||
211 | /* | |
212 | * this gets called before we allocate a new thread and copy the current task | |
213 | * into it so that we can store lazy state into memory | |
214 | */ | |
215 | void prepare_to_copy(struct task_struct *tsk) | |
216 | { | |
217 | unlazy_fpu(tsk); | |
218 | } | |
219 | ||
220 | /* | |
221 | * set up the kernel stack for a new thread and copy arch-specific thread | |
222 | * control information | |
223 | */ | |
6f2c55b8 | 224 | int copy_thread(unsigned long clone_flags, |
b920de1b DH |
225 | unsigned long c_usp, unsigned long ustk_size, |
226 | struct task_struct *p, struct pt_regs *kregs) | |
227 | { | |
7c7fcf76 | 228 | struct thread_info *ti = task_thread_info(p); |
b920de1b DH |
229 | struct pt_regs *c_uregs, *c_kregs, *uregs; |
230 | unsigned long c_ksp; | |
231 | ||
232 | uregs = current->thread.uregs; | |
233 | ||
234 | c_ksp = (unsigned long) task_stack_page(p) + THREAD_SIZE; | |
235 | ||
236 | /* allocate the userspace exception frame and set it up */ | |
237 | c_ksp -= sizeof(struct pt_regs); | |
238 | c_uregs = (struct pt_regs *) c_ksp; | |
239 | ||
240 | p->thread.uregs = c_uregs; | |
241 | *c_uregs = *uregs; | |
242 | c_uregs->sp = c_usp; | |
243 | c_uregs->epsw &= ~EPSW_FE; /* my FPU */ | |
244 | ||
245 | c_ksp -= 12; /* allocate function call ABI slack */ | |
246 | ||
247 | /* the new TLS pointer is passed in as arg #5 to sys_clone() */ | |
248 | if (clone_flags & CLONE_SETTLS) | |
7c7fcf76 | 249 | c_uregs->e2 = current_frame()->d3; |
b920de1b DH |
250 | |
251 | /* set up the return kernel frame if called from kernel_thread() */ | |
252 | c_kregs = c_uregs; | |
253 | if (kregs != uregs) { | |
254 | c_ksp -= sizeof(struct pt_regs); | |
255 | c_kregs = (struct pt_regs *) c_ksp; | |
256 | *c_kregs = *kregs; | |
257 | c_kregs->sp = c_usp; | |
258 | c_kregs->next = c_uregs; | |
259 | #ifdef CONFIG_MN10300_CURRENT_IN_E2 | |
260 | c_kregs->e2 = (unsigned long) p; /* current */ | |
261 | #endif | |
262 | ||
263 | c_ksp -= 12; /* allocate function call ABI slack */ | |
264 | } | |
265 | ||
266 | /* set up things up so the scheduler can start the new task */ | |
7c7fcf76 | 267 | ti->frame = c_kregs; |
b920de1b DH |
268 | p->thread.a3 = (unsigned long) c_kregs; |
269 | p->thread.sp = c_ksp; | |
270 | p->thread.pc = (unsigned long) ret_from_fork; | |
271 | p->thread.wchan = (unsigned long) ret_from_fork; | |
272 | p->thread.usp = c_usp; | |
273 | ||
274 | return 0; | |
275 | } | |
276 | ||
277 | /* | |
278 | * clone a process | |
7c7fcf76 | 279 | * - tlsptr is retrieved by copy_thread() from current_frame()->d3 |
b920de1b DH |
280 | */ |
281 | asmlinkage long sys_clone(unsigned long clone_flags, unsigned long newsp, | |
282 | int __user *parent_tidptr, int __user *child_tidptr, | |
283 | int __user *tlsptr) | |
284 | { | |
7c7fcf76 DH |
285 | return do_fork(clone_flags, newsp ?: current_frame()->sp, |
286 | current_frame(), 0, parent_tidptr, child_tidptr); | |
b920de1b DH |
287 | } |
288 | ||
289 | asmlinkage long sys_fork(void) | |
290 | { | |
7c7fcf76 DH |
291 | return do_fork(SIGCHLD, current_frame()->sp, |
292 | current_frame(), 0, NULL, NULL); | |
b920de1b DH |
293 | } |
294 | ||
295 | asmlinkage long sys_vfork(void) | |
296 | { | |
7c7fcf76 DH |
297 | return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, current_frame()->sp, |
298 | current_frame(), 0, NULL, NULL); | |
b920de1b DH |
299 | } |
300 | ||
c7887325 | 301 | asmlinkage long sys_execve(const char __user *name, |
d7627467 DH |
302 | const char __user *const __user *argv, |
303 | const char __user *const __user *envp) | |
b920de1b DH |
304 | { |
305 | char *filename; | |
306 | int error; | |
307 | ||
b920de1b DH |
308 | filename = getname(name); |
309 | error = PTR_ERR(filename); | |
8c0daee2 JK |
310 | if (IS_ERR(filename)) |
311 | return error; | |
7c7fcf76 | 312 | error = do_execve(filename, argv, envp, current_frame()); |
8c0daee2 | 313 | putname(filename); |
b920de1b DH |
314 | return error; |
315 | } | |
316 | ||
317 | unsigned long get_wchan(struct task_struct *p) | |
318 | { | |
319 | return p->thread.wchan; | |
320 | } |