Commit | Line | Data |
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88ef7f3f JB |
1 | /* |
2 | * OpenRISC process.c | |
3 | * | |
4 | * Linux architectural port borrowing liberally from similar works of | |
5 | * others. All original copyrights apply as per the original source | |
6 | * declaration. | |
7 | * | |
8 | * Modifications for the OpenRISC architecture: | |
9 | * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com> | |
10 | * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se> | |
11 | * | |
12 | * This program is free software; you can redistribute it and/or | |
13 | * modify it under the terms of the GNU General Public License | |
14 | * as published by the Free Software Foundation; either version | |
15 | * 2 of the License, or (at your option) any later version. | |
16 | * | |
17 | * This file handles the architecture-dependent parts of process handling... | |
18 | */ | |
19 | ||
20 | #define __KERNEL_SYSCALLS__ | |
21 | #include <stdarg.h> | |
22 | ||
23 | #include <linux/errno.h> | |
24 | #include <linux/sched.h> | |
25 | #include <linux/kernel.h> | |
26 | #include <linux/module.h> | |
27 | #include <linux/mm.h> | |
28 | #include <linux/stddef.h> | |
29 | #include <linux/unistd.h> | |
30 | #include <linux/ptrace.h> | |
31 | #include <linux/slab.h> | |
32 | #include <linux/elfcore.h> | |
33 | #include <linux/interrupt.h> | |
34 | #include <linux/delay.h> | |
35 | #include <linux/init_task.h> | |
36 | #include <linux/mqueue.h> | |
37 | #include <linux/fs.h> | |
38 | ||
39 | #include <asm/uaccess.h> | |
40 | #include <asm/pgtable.h> | |
88ef7f3f JB |
41 | #include <asm/io.h> |
42 | #include <asm/processor.h> | |
43 | #include <asm/spr_defs.h> | |
44 | ||
45 | #include <linux/smp.h> | |
46 | ||
47 | /* | |
48 | * Pointer to Current thread info structure. | |
49 | * | |
50 | * Used at user space -> kernel transitions. | |
51 | */ | |
52 | struct thread_info *current_thread_info_set[NR_CPUS] = { &init_thread_info, }; | |
53 | ||
54 | void machine_restart(void) | |
55 | { | |
56 | printk(KERN_INFO "*** MACHINE RESTART ***\n"); | |
57 | __asm__("l.nop 1"); | |
58 | } | |
59 | ||
60 | /* | |
61 | * Similar to machine_power_off, but don't shut off power. Add code | |
62 | * here to freeze the system for e.g. post-mortem debug purpose when | |
63 | * possible. This halt has nothing to do with the idle halt. | |
64 | */ | |
65 | void machine_halt(void) | |
66 | { | |
67 | printk(KERN_INFO "*** MACHINE HALT ***\n"); | |
68 | __asm__("l.nop 1"); | |
69 | } | |
70 | ||
71 | /* If or when software power-off is implemented, add code here. */ | |
72 | void machine_power_off(void) | |
73 | { | |
74 | printk(KERN_INFO "*** MACHINE POWER OFF ***\n"); | |
75 | __asm__("l.nop 1"); | |
76 | } | |
77 | ||
78 | void (*pm_power_off) (void) = machine_power_off; | |
79 | ||
80 | /* | |
81 | * When a process does an "exec", machine state like FPU and debug | |
82 | * registers need to be reset. This is a hook function for that. | |
83 | * Currently we don't have any such state to reset, so this is empty. | |
84 | */ | |
85 | void flush_thread(void) | |
86 | { | |
87 | } | |
88 | ||
89 | void show_regs(struct pt_regs *regs) | |
90 | { | |
91 | extern void show_registers(struct pt_regs *regs); | |
92 | ||
93 | /* __PHX__ cleanup this mess */ | |
94 | show_registers(regs); | |
95 | } | |
96 | ||
97 | unsigned long thread_saved_pc(struct task_struct *t) | |
98 | { | |
99 | return (unsigned long)user_regs(t->stack)->pc; | |
100 | } | |
101 | ||
102 | void release_thread(struct task_struct *dead_task) | |
103 | { | |
104 | } | |
105 | ||
106 | /* | |
107 | * Copy the thread-specific (arch specific) info from the current | |
108 | * process to the new one p | |
109 | */ | |
110 | extern asmlinkage void ret_from_fork(void); | |
111 | ||
112 | int | |
113 | copy_thread(unsigned long clone_flags, unsigned long usp, | |
114 | unsigned long unused, struct task_struct *p, struct pt_regs *regs) | |
115 | { | |
116 | struct pt_regs *childregs; | |
117 | struct pt_regs *kregs; | |
118 | unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE; | |
119 | struct thread_info *ti; | |
120 | unsigned long top_of_kernel_stack; | |
121 | ||
122 | top_of_kernel_stack = sp; | |
123 | ||
124 | p->set_child_tid = p->clear_child_tid = NULL; | |
125 | ||
126 | /* Copy registers */ | |
127 | /* redzone */ | |
128 | sp -= STACK_FRAME_OVERHEAD; | |
129 | sp -= sizeof(struct pt_regs); | |
130 | childregs = (struct pt_regs *)sp; | |
131 | ||
132 | /* Copy parent registers */ | |
133 | *childregs = *regs; | |
134 | ||
135 | if ((childregs->sr & SPR_SR_SM) == 1) { | |
136 | /* for kernel thread, set `current_thread_info' | |
137 | * and stackptr in new task | |
138 | */ | |
139 | childregs->sp = (unsigned long)task_stack_page(p) + THREAD_SIZE; | |
140 | childregs->gpr[10] = (unsigned long)task_thread_info(p); | |
141 | } else { | |
142 | childregs->sp = usp; | |
143 | } | |
144 | ||
145 | childregs->gpr[11] = 0; /* Result from fork() */ | |
146 | ||
147 | /* | |
148 | * The way this works is that at some point in the future | |
149 | * some task will call _switch to switch to the new task. | |
150 | * That will pop off the stack frame created below and start | |
151 | * the new task running at ret_from_fork. The new task will | |
152 | * do some house keeping and then return from the fork or clone | |
153 | * system call, using the stack frame created above. | |
154 | */ | |
155 | /* redzone */ | |
156 | sp -= STACK_FRAME_OVERHEAD; | |
157 | sp -= sizeof(struct pt_regs); | |
158 | kregs = (struct pt_regs *)sp; | |
159 | ||
160 | ti = task_thread_info(p); | |
161 | ti->ksp = sp; | |
162 | ||
163 | /* kregs->sp must store the location of the 'pre-switch' kernel stack | |
164 | * pointer... for a newly forked process, this is simply the top of | |
165 | * the kernel stack. | |
166 | */ | |
167 | kregs->sp = top_of_kernel_stack; | |
88ef7f3f JB |
168 | kregs->gpr[10] = (unsigned long)task_thread_info(p); |
169 | kregs->gpr[9] = (unsigned long)ret_from_fork; | |
170 | ||
171 | return 0; | |
172 | } | |
173 | ||
174 | /* | |
175 | * Set up a thread for executing a new program | |
176 | */ | |
177 | void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp) | |
178 | { | |
179 | unsigned long sr = regs->sr & ~SPR_SR_SM; | |
180 | ||
181 | set_fs(USER_DS); | |
182 | memset(regs->gpr, 0, sizeof(regs->gpr)); | |
183 | ||
184 | regs->pc = pc; | |
185 | regs->sr = sr; | |
186 | regs->sp = sp; | |
187 | ||
188 | /* printk("start thread, ksp = %lx\n", current_thread_info()->ksp);*/ | |
189 | } | |
190 | ||
191 | /* Fill in the fpu structure for a core dump. */ | |
192 | int dump_fpu(struct pt_regs *regs, elf_fpregset_t * fpu) | |
193 | { | |
194 | /* TODO */ | |
195 | return 0; | |
196 | } | |
197 | ||
198 | extern struct thread_info *_switch(struct thread_info *old_ti, | |
199 | struct thread_info *new_ti); | |
200 | ||
201 | struct task_struct *__switch_to(struct task_struct *old, | |
202 | struct task_struct *new) | |
203 | { | |
204 | struct task_struct *last; | |
205 | struct thread_info *new_ti, *old_ti; | |
206 | unsigned long flags; | |
207 | ||
208 | local_irq_save(flags); | |
209 | ||
210 | /* current_set is an array of saved current pointers | |
211 | * (one for each cpu). we need them at user->kernel transition, | |
212 | * while we save them at kernel->user transition | |
213 | */ | |
214 | new_ti = new->stack; | |
215 | old_ti = old->stack; | |
216 | ||
217 | current_thread_info_set[smp_processor_id()] = new_ti; | |
218 | last = (_switch(old_ti, new_ti))->task; | |
219 | ||
220 | local_irq_restore(flags); | |
221 | ||
222 | return last; | |
223 | } | |
224 | ||
225 | /* | |
226 | * Write out registers in core dump format, as defined by the | |
227 | * struct user_regs_struct | |
228 | */ | |
229 | void dump_elf_thread(elf_greg_t *dest, struct pt_regs* regs) | |
230 | { | |
231 | dest[0] = 0; /* r0 */ | |
232 | memcpy(dest+1, regs->gpr+1, 31*sizeof(unsigned long)); | |
233 | dest[32] = regs->pc; | |
234 | dest[33] = regs->sr; | |
235 | dest[34] = 0; | |
236 | dest[35] = 0; | |
237 | } | |
238 | ||
239 | extern void _kernel_thread_helper(void); | |
240 | ||
241 | void __noreturn kernel_thread_helper(int (*fn) (void *), void *arg) | |
242 | { | |
243 | do_exit(fn(arg)); | |
244 | } | |
245 | ||
246 | /* | |
247 | * Create a kernel thread. | |
248 | */ | |
249 | int kernel_thread(int (*fn) (void *), void *arg, unsigned long flags) | |
250 | { | |
251 | struct pt_regs regs; | |
252 | ||
253 | memset(®s, 0, sizeof(regs)); | |
254 | ||
255 | regs.gpr[20] = (unsigned long)fn; | |
256 | regs.gpr[22] = (unsigned long)arg; | |
257 | regs.sr = mfspr(SPR_SR); | |
258 | regs.pc = (unsigned long)_kernel_thread_helper; | |
259 | ||
260 | return do_fork(flags | CLONE_VM | CLONE_UNTRACED, | |
261 | 0, ®s, 0, NULL, NULL); | |
262 | } | |
263 | ||
264 | /* | |
265 | * sys_execve() executes a new program. | |
266 | */ | |
267 | asmlinkage long _sys_execve(const char __user *name, | |
268 | const char __user * const __user *argv, | |
269 | const char __user * const __user *envp, | |
270 | struct pt_regs *regs) | |
271 | { | |
272 | int error; | |
91a27b2a | 273 | struct filename *filename; |
88ef7f3f JB |
274 | |
275 | filename = getname(name); | |
276 | error = PTR_ERR(filename); | |
277 | ||
278 | if (IS_ERR(filename)) | |
279 | goto out; | |
280 | ||
91a27b2a | 281 | error = do_execve(filename->name, argv, envp, regs); |
88ef7f3f JB |
282 | putname(filename); |
283 | ||
284 | out: | |
285 | return error; | |
286 | } | |
287 | ||
288 | unsigned long get_wchan(struct task_struct *p) | |
289 | { | |
290 | /* TODO */ | |
291 | ||
292 | return 0; | |
293 | } | |
294 | ||
295 | int kernel_execve(const char *filename, char *const argv[], char *const envp[]) | |
296 | { | |
297 | register long __res asm("r11") = __NR_execve; | |
298 | register long __a asm("r3") = (long)(filename); | |
299 | register long __b asm("r4") = (long)(argv); | |
300 | register long __c asm("r5") = (long)(envp); | |
301 | __asm__ volatile ("l.sys 1" | |
302 | : "=r" (__res), "=r"(__a), "=r"(__b), "=r"(__c) | |
303 | : "0"(__res), "1"(__a), "2"(__b), "3"(__c) | |
304 | : "r6", "r7", "r8", "r12", "r13", "r15", | |
305 | "r17", "r19", "r21", "r23", "r25", "r27", | |
306 | "r29", "r31"); | |
307 | __asm__ volatile ("l.nop"); | |
308 | return __res; | |
309 | } |