1 /*
2 * linux/arch/h8300/kernel/process.c
3 *
4 * Yoshinori Sato <ysato@users.sourceforge.jp>
5 *
6 * Based on:
7 *
8 * linux/arch/m68knommu/kernel/process.c
9 *
10 * Copyright (C) 1998 D. Jeff Dionne <jeff@ryeham.ee.ryerson.ca>,
11 * Kenneth Albanowski <kjahds@kjahds.com>,
12 * The Silver Hammer Group, Ltd.
13 *
14 * linux/arch/m68k/kernel/process.c
15 *
16 * Copyright (C) 1995 Hamish Macdonald
17 *
18 * 68060 fixes by Jesper Skov
19 */
20
21 /*
22 * This file handles the architecture-dependent parts of process handling..
23 */
24
25 #include <linux/errno.h>
26 #include <linux/module.h>
27 #include <linux/sched.h>
28 #include <linux/kernel.h>
29 #include <linux/mm.h>
30 #include <linux/smp.h>
31 #include <linux/stddef.h>
32 #include <linux/unistd.h>
33 #include <linux/ptrace.h>
34 #include <linux/user.h>
35 #include <linux/interrupt.h>
36 #include <linux/reboot.h>
37 #include <linux/fs.h>
38 #include <linux/slab.h>
39 #include <linux/rcupdate.h>
40
41 #include <asm/uaccess.h>
42 #include <asm/traps.h>
43 #include <asm/setup.h>
44 #include <asm/pgtable.h>
45
46 void (*pm_power_off)(void) = NULL;
47 EXPORT_SYMBOL(pm_power_off);
48
49 asmlinkage void ret_from_fork(void);
50
51 /*
52 * The idle loop on an H8/300..
53 */
54 #if !defined(CONFIG_H8300H_SIM) && !defined(CONFIG_H8S_SIM)
default_idle(void)55 static void default_idle(void)
56 {
57 local_irq_disable();
58 if (!need_resched()) {
59 local_irq_enable();
60 /* XXX: race here! What if need_resched() gets set now? */
61 __asm__("sleep");
62 } else
63 local_irq_enable();
64 }
65 #else
default_idle(void)66 static void default_idle(void)
67 {
68 cpu_relax();
69 }
70 #endif
71 void (*idle)(void) = default_idle;
72
73 /*
74 * The idle thread. There's no useful work to be
75 * done, so just try to conserve power and have a
76 * low exit latency (ie sit in a loop waiting for
77 * somebody to say that they'd like to reschedule)
78 */
cpu_idle(void)79 void cpu_idle(void)
80 {
81 while (1) {
82 rcu_idle_enter();
83 while (!need_resched())
84 idle();
85 rcu_idle_exit();
86 schedule_preempt_disabled();
87 }
88 }
89
machine_restart(char * __unused)90 void machine_restart(char * __unused)
91 {
92 local_irq_disable();
93 __asm__("jmp @@0");
94 }
95
machine_halt(void)96 void machine_halt(void)
97 {
98 local_irq_disable();
99 __asm__("sleep");
100 for (;;);
101 }
102
machine_power_off(void)103 void machine_power_off(void)
104 {
105 local_irq_disable();
106 __asm__("sleep");
107 for (;;);
108 }
109
show_regs(struct pt_regs * regs)110 void show_regs(struct pt_regs * regs)
111 {
112 printk("\nPC: %08lx Status: %02x",
113 regs->pc, regs->ccr);
114 printk("\nORIG_ER0: %08lx ER0: %08lx ER1: %08lx",
115 regs->orig_er0, regs->er0, regs->er1);
116 printk("\nER2: %08lx ER3: %08lx ER4: %08lx ER5: %08lx",
117 regs->er2, regs->er3, regs->er4, regs->er5);
118 printk("\nER6' %08lx ",regs->er6);
119 if (user_mode(regs))
120 printk("USP: %08lx\n", rdusp());
121 else
122 printk("\n");
123 }
124
125 /*
126 * Create a kernel thread
127 */
kernel_thread(int (* fn)(void *),void * arg,unsigned long flags)128 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
129 {
130 long retval;
131 long clone_arg;
132 mm_segment_t fs;
133
134 fs = get_fs();
135 set_fs (KERNEL_DS);
136 clone_arg = flags | CLONE_VM;
137 __asm__("mov.l sp,er3\n\t"
138 "sub.l er2,er2\n\t"
139 "mov.l %2,er1\n\t"
140 "mov.l %1,er0\n\t"
141 "trapa #0\n\t"
142 "cmp.l sp,er3\n\t"
143 "beq 1f\n\t"
144 "mov.l %4,er0\n\t"
145 "mov.l %3,er1\n\t"
146 "jsr @er1\n\t"
147 "mov.l %5,er0\n\t"
148 "trapa #0\n"
149 "1:\n\t"
150 "mov.l er0,%0"
151 :"=r"(retval)
152 :"i"(__NR_clone),"g"(clone_arg),"g"(fn),"g"(arg),"i"(__NR_exit)
153 :"er0","er1","er2","er3");
154 set_fs (fs);
155 return retval;
156 }
157
flush_thread(void)158 void flush_thread(void)
159 {
160 }
161
162 /*
163 * "h8300_fork()".. By the time we get here, the
164 * non-volatile registers have also been saved on the
165 * stack. We do some ugly pointer stuff here.. (see
166 * also copy_thread)
167 */
168
h8300_fork(struct pt_regs * regs)169 asmlinkage int h8300_fork(struct pt_regs *regs)
170 {
171 return -EINVAL;
172 }
173
h8300_vfork(struct pt_regs * regs)174 asmlinkage int h8300_vfork(struct pt_regs *regs)
175 {
176 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL, NULL);
177 }
178
h8300_clone(struct pt_regs * regs)179 asmlinkage int h8300_clone(struct pt_regs *regs)
180 {
181 unsigned long clone_flags;
182 unsigned long newsp;
183
184 /* syscall2 puts clone_flags in er1 and usp in er2 */
185 clone_flags = regs->er1;
186 newsp = regs->er2;
187 if (!newsp)
188 newsp = rdusp();
189 return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
190
191 }
192
copy_thread(unsigned long clone_flags,unsigned long usp,unsigned long topstk,struct task_struct * p,struct pt_regs * regs)193 int copy_thread(unsigned long clone_flags,
194 unsigned long usp, unsigned long topstk,
195 struct task_struct * p, struct pt_regs * regs)
196 {
197 struct pt_regs * childregs;
198
199 childregs = (struct pt_regs *) (THREAD_SIZE + task_stack_page(p)) - 1;
200
201 *childregs = *regs;
202 childregs->retpc = (unsigned long) ret_from_fork;
203 childregs->er0 = 0;
204
205 p->thread.usp = usp;
206 p->thread.ksp = (unsigned long)childregs;
207
208 return 0;
209 }
210
211 /*
212 * sys_execve() executes a new program.
213 */
sys_execve(const char * name,const char * const * argv,const char * const * envp,int dummy,...)214 asmlinkage int sys_execve(const char *name,
215 const char *const *argv,
216 const char *const *envp,
217 int dummy, ...)
218 {
219 int error;
220 char * filename;
221 struct pt_regs *regs = (struct pt_regs *) ((unsigned char *)&dummy-4);
222
223 filename = getname(name);
224 error = PTR_ERR(filename);
225 if (IS_ERR(filename))
226 return error;
227 error = do_execve(filename, argv, envp, regs);
228 putname(filename);
229 return error;
230 }
231
thread_saved_pc(struct task_struct * tsk)232 unsigned long thread_saved_pc(struct task_struct *tsk)
233 {
234 return ((struct pt_regs *)tsk->thread.esp0)->pc;
235 }
236
get_wchan(struct task_struct * p)237 unsigned long get_wchan(struct task_struct *p)
238 {
239 unsigned long fp, pc;
240 unsigned long stack_page;
241 int count = 0;
242 if (!p || p == current || p->state == TASK_RUNNING)
243 return 0;
244
245 stack_page = (unsigned long)p;
246 fp = ((struct pt_regs *)p->thread.ksp)->er6;
247 do {
248 if (fp < stack_page+sizeof(struct thread_info) ||
249 fp >= 8184+stack_page)
250 return 0;
251 pc = ((unsigned long *)fp)[1];
252 if (!in_sched_functions(pc))
253 return pc;
254 fp = *(unsigned long *) fp;
255 } while (count++ < 16);
256 return 0;
257 }
258