Commit | Line | Data |
---|---|---|
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 | ||
cbf23cf1 JB |
112 | /* |
113 | * copy_thread | |
114 | * @clone_flags: flags | |
115 | * @usp: user stack pointer or fn for kernel thread | |
116 | * @arg: arg to fn for kernel thread; always NULL for userspace thread | |
117 | * @p: the newly created task | |
118 | * @regs: CPU context to copy for userspace thread; always NULL for kthread | |
119 | * | |
120 | * At the top of a newly initialized kernel stack are two stacked pt_reg | |
121 | * structures. The first (topmost) is the userspace context of the thread. | |
122 | * The second is the kernelspace context of the thread. | |
123 | * | |
124 | * A kernel thread will not be returning to userspace, so the topmost pt_regs | |
125 | * struct can be uninitialized; it _does_ need to exist, though, because | |
126 | * a kernel thread can become a userspace thread by doing a kernel_execve, in | |
127 | * which case the topmost context will be initialized and used for 'returning' | |
128 | * to userspace. | |
129 | * | |
130 | * The second pt_reg struct needs to be initialized to 'return' to | |
131 | * ret_from_fork. A kernel thread will need to set r20 to the address of | |
132 | * a function to call into (with arg in r22); userspace threads need to set | |
133 | * r20 to NULL in which case ret_from_fork will just continue a return to | |
134 | * userspace. | |
135 | * | |
136 | * A kernel thread 'fn' may return; this is effectively what happens when | |
137 | * kernel_execve is called. In that case, the userspace pt_regs must have | |
138 | * been initialized (which kernel_execve takes care of, see start_thread | |
139 | * below); ret_from_fork will then continue its execution causing the | |
140 | * 'kernel thread' to return to userspace as a userspace thread. | |
141 | */ | |
142 | ||
88ef7f3f JB |
143 | int |
144 | copy_thread(unsigned long clone_flags, unsigned long usp, | |
afa86fc4 | 145 | unsigned long arg, struct task_struct *p) |
88ef7f3f | 146 | { |
cbf23cf1 | 147 | struct pt_regs *userregs; |
88ef7f3f JB |
148 | struct pt_regs *kregs; |
149 | unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE; | |
88ef7f3f JB |
150 | unsigned long top_of_kernel_stack; |
151 | ||
152 | top_of_kernel_stack = sp; | |
153 | ||
154 | p->set_child_tid = p->clear_child_tid = NULL; | |
155 | ||
cbf23cf1 JB |
156 | /* Locate userspace context on stack... */ |
157 | sp -= STACK_FRAME_OVERHEAD; /* redzone */ | |
88ef7f3f | 158 | sp -= sizeof(struct pt_regs); |
cbf23cf1 | 159 | userregs = (struct pt_regs *) sp; |
88ef7f3f | 160 | |
cbf23cf1 JB |
161 | /* ...and kernel context */ |
162 | sp -= STACK_FRAME_OVERHEAD; /* redzone */ | |
163 | sp -= sizeof(struct pt_regs); | |
164 | kregs = (struct pt_regs *)sp; | |
88ef7f3f | 165 | |
cbf23cf1 JB |
166 | if (unlikely(p->flags & PF_KTHREAD)) { |
167 | memset(kregs, 0, sizeof(struct pt_regs)); | |
168 | kregs->gpr[20] = usp; /* fn, kernel thread */ | |
169 | kregs->gpr[22] = arg; | |
88ef7f3f | 170 | } else { |
39d91a9e | 171 | *userregs = *current_pt_regs(); |
88ef7f3f | 172 | |
39d91a9e AV |
173 | if (usp) |
174 | userregs->sp = usp; | |
cbf23cf1 | 175 | userregs->gpr[11] = 0; /* Result from fork() */ |
88ef7f3f | 176 | |
cbf23cf1 JB |
177 | kregs->gpr[20] = 0; /* Userspace thread */ |
178 | } | |
88ef7f3f | 179 | |
cbf23cf1 JB |
180 | /* |
181 | * _switch wants the kernel stack page in pt_regs->sp so that it | |
182 | * can restore it to thread_info->ksp... see _switch for details. | |
88ef7f3f JB |
183 | */ |
184 | kregs->sp = top_of_kernel_stack; | |
88ef7f3f JB |
185 | kregs->gpr[9] = (unsigned long)ret_from_fork; |
186 | ||
cbf23cf1 JB |
187 | task_thread_info(p)->ksp = (unsigned long)kregs; |
188 | ||
88ef7f3f JB |
189 | return 0; |
190 | } | |
191 | ||
192 | /* | |
193 | * Set up a thread for executing a new program | |
194 | */ | |
195 | void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp) | |
196 | { | |
cbf23cf1 | 197 | unsigned long sr = mfspr(SPR_SR) & ~SPR_SR_SM; |
88ef7f3f JB |
198 | |
199 | set_fs(USER_DS); | |
cbf23cf1 | 200 | memset(regs, 0, sizeof(struct pt_regs)); |
88ef7f3f JB |
201 | |
202 | regs->pc = pc; | |
203 | regs->sr = sr; | |
204 | regs->sp = sp; | |
88ef7f3f JB |
205 | } |
206 | ||
207 | /* Fill in the fpu structure for a core dump. */ | |
208 | int dump_fpu(struct pt_regs *regs, elf_fpregset_t * fpu) | |
209 | { | |
210 | /* TODO */ | |
211 | return 0; | |
212 | } | |
213 | ||
214 | extern struct thread_info *_switch(struct thread_info *old_ti, | |
215 | struct thread_info *new_ti); | |
216 | ||
217 | struct task_struct *__switch_to(struct task_struct *old, | |
218 | struct task_struct *new) | |
219 | { | |
220 | struct task_struct *last; | |
221 | struct thread_info *new_ti, *old_ti; | |
222 | unsigned long flags; | |
223 | ||
224 | local_irq_save(flags); | |
225 | ||
226 | /* current_set is an array of saved current pointers | |
227 | * (one for each cpu). we need them at user->kernel transition, | |
228 | * while we save them at kernel->user transition | |
229 | */ | |
230 | new_ti = new->stack; | |
231 | old_ti = old->stack; | |
232 | ||
233 | current_thread_info_set[smp_processor_id()] = new_ti; | |
234 | last = (_switch(old_ti, new_ti))->task; | |
235 | ||
236 | local_irq_restore(flags); | |
237 | ||
238 | return last; | |
239 | } | |
240 | ||
241 | /* | |
242 | * Write out registers in core dump format, as defined by the | |
243 | * struct user_regs_struct | |
244 | */ | |
245 | void dump_elf_thread(elf_greg_t *dest, struct pt_regs* regs) | |
246 | { | |
247 | dest[0] = 0; /* r0 */ | |
248 | memcpy(dest+1, regs->gpr+1, 31*sizeof(unsigned long)); | |
249 | dest[32] = regs->pc; | |
250 | dest[33] = regs->sr; | |
251 | dest[34] = 0; | |
252 | dest[35] = 0; | |
253 | } | |
254 | ||
88ef7f3f JB |
255 | unsigned long get_wchan(struct task_struct *p) |
256 | { | |
257 | /* TODO */ | |
258 | ||
259 | return 0; | |
260 | } |