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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>
41#include <asm/system.h>
42#include <asm/io.h>
43#include <asm/processor.h>
44#include <asm/spr_defs.h>
45
46#include <linux/smp.h>
47
48/*
49 * Pointer to Current thread info structure.
50 *
51 * Used at user space -> kernel transitions.
52 */
53struct thread_info *current_thread_info_set[NR_CPUS] = { &init_thread_info, };
54
55void machine_restart(void)
56{
57 printk(KERN_INFO "*** MACHINE RESTART ***\n");
58 __asm__("l.nop 1");
59}
60
61/*
62 * Similar to machine_power_off, but don't shut off power. Add code
63 * here to freeze the system for e.g. post-mortem debug purpose when
64 * possible. This halt has nothing to do with the idle halt.
65 */
66void machine_halt(void)
67{
68 printk(KERN_INFO "*** MACHINE HALT ***\n");
69 __asm__("l.nop 1");
70}
71
72/* If or when software power-off is implemented, add code here. */
73void machine_power_off(void)
74{
75 printk(KERN_INFO "*** MACHINE POWER OFF ***\n");
76 __asm__("l.nop 1");
77}
78
79void (*pm_power_off) (void) = machine_power_off;
80
81/*
82 * When a process does an "exec", machine state like FPU and debug
83 * registers need to be reset. This is a hook function for that.
84 * Currently we don't have any such state to reset, so this is empty.
85 */
86void flush_thread(void)
87{
88}
89
90void show_regs(struct pt_regs *regs)
91{
92 extern void show_registers(struct pt_regs *regs);
93
94 /* __PHX__ cleanup this mess */
95 show_registers(regs);
96}
97
98unsigned long thread_saved_pc(struct task_struct *t)
99{
100 return (unsigned long)user_regs(t->stack)->pc;
101}
102
103void release_thread(struct task_struct *dead_task)
104{
105}
106
107/*
108 * Copy the thread-specific (arch specific) info from the current
109 * process to the new one p
110 */
111extern asmlinkage void ret_from_fork(void);
112
113int
114copy_thread(unsigned long clone_flags, unsigned long usp,
115 unsigned long unused, struct task_struct *p, struct pt_regs *regs)
116{
117 struct pt_regs *childregs;
118 struct pt_regs *kregs;
119 unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
120 struct thread_info *ti;
121 unsigned long top_of_kernel_stack;
122
123 top_of_kernel_stack = sp;
124
125 p->set_child_tid = p->clear_child_tid = NULL;
126
127 /* Copy registers */
128 /* redzone */
129 sp -= STACK_FRAME_OVERHEAD;
130 sp -= sizeof(struct pt_regs);
131 childregs = (struct pt_regs *)sp;
132
133 /* Copy parent registers */
134 *childregs = *regs;
135
136 if ((childregs->sr & SPR_SR_SM) == 1) {
137 /* for kernel thread, set `current_thread_info'
138 * and stackptr in new task
139 */
140 childregs->sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
141 childregs->gpr[10] = (unsigned long)task_thread_info(p);
142 } else {
143 childregs->sp = usp;
144 }
145
146 childregs->gpr[11] = 0; /* Result from fork() */
147
148 /*
149 * The way this works is that at some point in the future
150 * some task will call _switch to switch to the new task.
151 * That will pop off the stack frame created below and start
152 * the new task running at ret_from_fork. The new task will
153 * do some house keeping and then return from the fork or clone
154 * system call, using the stack frame created above.
155 */
156 /* redzone */
157 sp -= STACK_FRAME_OVERHEAD;
158 sp -= sizeof(struct pt_regs);
159 kregs = (struct pt_regs *)sp;
160
161 ti = task_thread_info(p);
162 ti->ksp = sp;
163
164 /* kregs->sp must store the location of the 'pre-switch' kernel stack
165 * pointer... for a newly forked process, this is simply the top of
166 * the kernel stack.
167 */
168 kregs->sp = top_of_kernel_stack;
169 kregs->gpr[3] = (unsigned long)current; /* arg to schedule_tail */
170 kregs->gpr[10] = (unsigned long)task_thread_info(p);
171 kregs->gpr[9] = (unsigned long)ret_from_fork;
172
173 return 0;
174}
175
176/*
177 * Set up a thread for executing a new program
178 */
179void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp)
180{
181 unsigned long sr = regs->sr & ~SPR_SR_SM;
182
183 set_fs(USER_DS);
184 memset(regs->gpr, 0, sizeof(regs->gpr));
185
186 regs->pc = pc;
187 regs->sr = sr;
188 regs->sp = sp;
189
190/* printk("start thread, ksp = %lx\n", current_thread_info()->ksp);*/
191}
192
193/* Fill in the fpu structure for a core dump. */
194int dump_fpu(struct pt_regs *regs, elf_fpregset_t * fpu)
195{
196 /* TODO */
197 return 0;
198}
199
200extern struct thread_info *_switch(struct thread_info *old_ti,
201 struct thread_info *new_ti);
202
203struct task_struct *__switch_to(struct task_struct *old,
204 struct task_struct *new)
205{
206 struct task_struct *last;
207 struct thread_info *new_ti, *old_ti;
208 unsigned long flags;
209
210 local_irq_save(flags);
211
212 /* current_set is an array of saved current pointers
213 * (one for each cpu). we need them at user->kernel transition,
214 * while we save them at kernel->user transition
215 */
216 new_ti = new->stack;
217 old_ti = old->stack;
218
219 current_thread_info_set[smp_processor_id()] = new_ti;
220 last = (_switch(old_ti, new_ti))->task;
221
222 local_irq_restore(flags);
223
224 return last;
225}
226
227/*
228 * Write out registers in core dump format, as defined by the
229 * struct user_regs_struct
230 */
231void dump_elf_thread(elf_greg_t *dest, struct pt_regs* regs)
232{
233 dest[0] = 0; /* r0 */
234 memcpy(dest+1, regs->gpr+1, 31*sizeof(unsigned long));
235 dest[32] = regs->pc;
236 dest[33] = regs->sr;
237 dest[34] = 0;
238 dest[35] = 0;
239}
240
241extern void _kernel_thread_helper(void);
242
243void __noreturn kernel_thread_helper(int (*fn) (void *), void *arg)
244{
245 do_exit(fn(arg));
246}
247
248/*
249 * Create a kernel thread.
250 */
251int kernel_thread(int (*fn) (void *), void *arg, unsigned long flags)
252{
253 struct pt_regs regs;
254
255 memset(®s, 0, sizeof(regs));
256
257 regs.gpr[20] = (unsigned long)fn;
258 regs.gpr[22] = (unsigned long)arg;
259 regs.sr = mfspr(SPR_SR);
260 regs.pc = (unsigned long)_kernel_thread_helper;
261
262 return do_fork(flags | CLONE_VM | CLONE_UNTRACED,
263 0, ®s, 0, NULL, NULL);
264}
265
266/*
267 * sys_execve() executes a new program.
268 */
269asmlinkage long _sys_execve(const char __user *name,
270 const char __user * const __user *argv,
271 const char __user * const __user *envp,
272 struct pt_regs *regs)
273{
274 int error;
275 char *filename;
276
277 filename = getname(name);
278 error = PTR_ERR(filename);
279
280 if (IS_ERR(filename))
281 goto out;
282
283 error = do_execve(filename, argv, envp, regs);
284 putname(filename);
285
286out:
287 return error;
288}
289
290unsigned long get_wchan(struct task_struct *p)
291{
292 /* TODO */
293
294 return 0;
295}
296
297int kernel_execve(const char *filename, char *const argv[], char *const envp[])
298{
299 register long __res asm("r11") = __NR_execve;
300 register long __a asm("r3") = (long)(filename);
301 register long __b asm("r4") = (long)(argv);
302 register long __c asm("r5") = (long)(envp);
303 __asm__ volatile ("l.sys 1"
304 : "=r" (__res), "=r"(__a), "=r"(__b), "=r"(__c)
305 : "0"(__res), "1"(__a), "2"(__b), "3"(__c)
306 : "r6", "r7", "r8", "r12", "r13", "r15",
307 "r17", "r19", "r21", "r23", "r25", "r27",
308 "r29", "r31");
309 __asm__ volatile ("l.nop");
310 return __res;
311}
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>
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 */
52struct thread_info *current_thread_info_set[NR_CPUS] = { &init_thread_info, };
53
54void 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 */
65void 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. */
72void machine_power_off(void)
73{
74 printk(KERN_INFO "*** MACHINE POWER OFF ***\n");
75 __asm__("l.nop 1");
76}
77
78void (*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 */
85void flush_thread(void)
86{
87}
88
89void 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
97unsigned long thread_saved_pc(struct task_struct *t)
98{
99 return (unsigned long)user_regs(t->stack)->pc;
100}
101
102void 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 */
110extern asmlinkage void ret_from_fork(void);
111
112int
113copy_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;
168 kregs->gpr[3] = (unsigned long)current; /* arg to schedule_tail */
169 kregs->gpr[10] = (unsigned long)task_thread_info(p);
170 kregs->gpr[9] = (unsigned long)ret_from_fork;
171
172 return 0;
173}
174
175/*
176 * Set up a thread for executing a new program
177 */
178void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp)
179{
180 unsigned long sr = regs->sr & ~SPR_SR_SM;
181
182 set_fs(USER_DS);
183 memset(regs->gpr, 0, sizeof(regs->gpr));
184
185 regs->pc = pc;
186 regs->sr = sr;
187 regs->sp = sp;
188
189/* printk("start thread, ksp = %lx\n", current_thread_info()->ksp);*/
190}
191
192/* Fill in the fpu structure for a core dump. */
193int dump_fpu(struct pt_regs *regs, elf_fpregset_t * fpu)
194{
195 /* TODO */
196 return 0;
197}
198
199extern struct thread_info *_switch(struct thread_info *old_ti,
200 struct thread_info *new_ti);
201
202struct task_struct *__switch_to(struct task_struct *old,
203 struct task_struct *new)
204{
205 struct task_struct *last;
206 struct thread_info *new_ti, *old_ti;
207 unsigned long flags;
208
209 local_irq_save(flags);
210
211 /* current_set is an array of saved current pointers
212 * (one for each cpu). we need them at user->kernel transition,
213 * while we save them at kernel->user transition
214 */
215 new_ti = new->stack;
216 old_ti = old->stack;
217
218 current_thread_info_set[smp_processor_id()] = new_ti;
219 last = (_switch(old_ti, new_ti))->task;
220
221 local_irq_restore(flags);
222
223 return last;
224}
225
226/*
227 * Write out registers in core dump format, as defined by the
228 * struct user_regs_struct
229 */
230void dump_elf_thread(elf_greg_t *dest, struct pt_regs* regs)
231{
232 dest[0] = 0; /* r0 */
233 memcpy(dest+1, regs->gpr+1, 31*sizeof(unsigned long));
234 dest[32] = regs->pc;
235 dest[33] = regs->sr;
236 dest[34] = 0;
237 dest[35] = 0;
238}
239
240extern void _kernel_thread_helper(void);
241
242void __noreturn kernel_thread_helper(int (*fn) (void *), void *arg)
243{
244 do_exit(fn(arg));
245}
246
247/*
248 * Create a kernel thread.
249 */
250int kernel_thread(int (*fn) (void *), void *arg, unsigned long flags)
251{
252 struct pt_regs regs;
253
254 memset(®s, 0, sizeof(regs));
255
256 regs.gpr[20] = (unsigned long)fn;
257 regs.gpr[22] = (unsigned long)arg;
258 regs.sr = mfspr(SPR_SR);
259 regs.pc = (unsigned long)_kernel_thread_helper;
260
261 return do_fork(flags | CLONE_VM | CLONE_UNTRACED,
262 0, ®s, 0, NULL, NULL);
263}
264
265/*
266 * sys_execve() executes a new program.
267 */
268asmlinkage long _sys_execve(const char __user *name,
269 const char __user * const __user *argv,
270 const char __user * const __user *envp,
271 struct pt_regs *regs)
272{
273 int error;
274 char *filename;
275
276 filename = getname(name);
277 error = PTR_ERR(filename);
278
279 if (IS_ERR(filename))
280 goto out;
281
282 error = do_execve(filename, argv, envp, regs);
283 putname(filename);
284
285out:
286 return error;
287}
288
289unsigned long get_wchan(struct task_struct *p)
290{
291 /* TODO */
292
293 return 0;
294}
295
296int kernel_execve(const char *filename, char *const argv[], char *const envp[])
297{
298 register long __res asm("r11") = __NR_execve;
299 register long __a asm("r3") = (long)(filename);
300 register long __b asm("r4") = (long)(argv);
301 register long __c asm("r5") = (long)(envp);
302 __asm__ volatile ("l.sys 1"
303 : "=r" (__res), "=r"(__a), "=r"(__b), "=r"(__c)
304 : "0"(__res), "1"(__a), "2"(__b), "3"(__c)
305 : "r6", "r7", "r8", "r12", "r13", "r15",
306 "r17", "r19", "r21", "r23", "r25", "r27",
307 "r29", "r31");
308 __asm__ volatile ("l.nop");
309 return __res;
310}