blob: ed79ae20e88d4a58800da6204648820bd6171666 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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/config.h>
26#include <linux/errno.h>
27#include <linux/module.h>
28#include <linux/sched.h>
29#include <linux/kernel.h>
30#include <linux/mm.h>
31#include <linux/smp.h>
32#include <linux/smp_lock.h>
33#include <linux/stddef.h>
34#include <linux/unistd.h>
35#include <linux/ptrace.h>
36#include <linux/slab.h>
37#include <linux/user.h>
38#include <linux/a.out.h>
39#include <linux/interrupt.h>
40#include <linux/reboot.h>
41
42#include <asm/uaccess.h>
43#include <asm/system.h>
44#include <asm/traps.h>
45#include <asm/setup.h>
46#include <asm/pgtable.h>
47
48asmlinkage void ret_from_fork(void);
49
50/*
51 * The idle loop on an H8/300..
52 */
53#if !defined(CONFIG_H8300H_SIM) && !defined(CONFIG_H8S_SIM)
54void default_idle(void)
55{
Nick Piggin5bfb5d62005-11-08 21:39:01 -080056 local_irq_disable();
57 if (!need_resched()) {
58 local_irq_enable();
59 /* XXX: race here! What if need_resched() gets set now? */
60 __asm__("sleep");
61 } else
62 local_irq_enable();
Linus Torvalds1da177e2005-04-16 15:20:36 -070063}
64#else
65void default_idle(void)
66{
Nick Piggin5bfb5d62005-11-08 21:39:01 -080067 cpu_relax();
Linus Torvalds1da177e2005-04-16 15:20:36 -070068}
69#endif
70void (*idle)(void) = default_idle;
71
72/*
73 * The idle thread. There's no useful work to be
74 * done, so just try to conserve power and have a
75 * low exit latency (ie sit in a loop waiting for
76 * somebody to say that they'd like to reschedule)
77 */
78void cpu_idle(void)
79{
Nick Piggin5bfb5d62005-11-08 21:39:01 -080080 while (1) {
81 while (!need_resched())
82 idle();
83 preempt_enable_no_resched();
84 schedule();
85 preempt_disable();
86 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070087}
88
89void machine_restart(char * __unused)
90{
91 local_irq_disable();
92 __asm__("jmp @@0");
93}
94
Linus Torvalds1da177e2005-04-16 15:20:36 -070095void machine_halt(void)
96{
97 local_irq_disable();
98 __asm__("sleep");
99 for (;;);
100}
101
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102void machine_power_off(void)
103{
104 local_irq_disable();
105 __asm__("sleep");
106 for (;;);
107}
108
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109void show_regs(struct pt_regs * regs)
110{
111 printk("\nPC: %08lx Status: %02x",
112 regs->pc, regs->ccr);
113 printk("\nORIG_ER0: %08lx ER0: %08lx ER1: %08lx",
114 regs->orig_er0, regs->er0, regs->er1);
115 printk("\nER2: %08lx ER3: %08lx ER4: %08lx ER5: %08lx",
116 regs->er2, regs->er3, regs->er4, regs->er5);
117 printk("\nER6' %08lx ",regs->er6);
118 if (user_mode(regs))
119 printk("USP: %08lx\n", rdusp());
120 else
121 printk("\n");
122}
123
124/*
125 * Create a kernel thread
126 */
127int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
128{
129 long retval;
130 long clone_arg;
131 mm_segment_t fs;
132
133 fs = get_fs();
134 set_fs (KERNEL_DS);
135 clone_arg = flags | CLONE_VM;
136 __asm__("mov.l sp,er3\n\t"
137 "sub.l er2,er2\n\t"
138 "mov.l %2,er1\n\t"
139 "mov.l %1,er0\n\t"
140 "trapa #0\n\t"
141 "cmp.l sp,er3\n\t"
142 "beq 1f\n\t"
143 "mov.l %4,er0\n\t"
144 "mov.l %3,er1\n\t"
145 "jsr @er1\n\t"
146 "mov.l %5,er0\n\t"
147 "trapa #0\n"
148 "1:\n\t"
149 "mov.l er0,%0"
150 :"=r"(retval)
151 :"i"(__NR_clone),"g"(clone_arg),"g"(fn),"g"(arg),"i"(__NR_exit)
152 :"er0","er1","er2","er3");
153 set_fs (fs);
154 return retval;
155}
156
157void flush_thread(void)
158{
159}
160
161/*
162 * "h8300_fork()".. By the time we get here, the
163 * non-volatile registers have also been saved on the
164 * stack. We do some ugly pointer stuff here.. (see
165 * also copy_thread)
166 */
167
168asmlinkage int h8300_fork(struct pt_regs *regs)
169{
170 return -EINVAL;
171}
172
173asmlinkage int h8300_vfork(struct pt_regs *regs)
174{
175 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL, NULL);
176}
177
178asmlinkage int h8300_clone(struct pt_regs *regs)
179{
180 unsigned long clone_flags;
181 unsigned long newsp;
182
183 /* syscall2 puts clone_flags in er1 and usp in er2 */
184 clone_flags = regs->er1;
185 newsp = regs->er2;
186 if (!newsp)
187 newsp = rdusp();
188 return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
189
190}
191
192int copy_thread(int nr, unsigned long clone_flags,
193 unsigned long usp, unsigned long topstk,
194 struct task_struct * p, struct pt_regs * regs)
195{
196 struct pt_regs * childregs;
197
Al Viro68f8b1f2006-01-12 01:05:55 -0800198 childregs = (struct pt_regs *) (THREAD_SIZE + task_stack_page(p)) - 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199
200 *childregs = *regs;
201 childregs->retpc = (unsigned long) ret_from_fork;
202 childregs->er0 = 0;
203
204 p->thread.usp = usp;
205 p->thread.ksp = (unsigned long)childregs;
206
207 return 0;
208}
209
210/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 * sys_execve() executes a new program.
212 */
213asmlinkage int sys_execve(char *name, char **argv, char **envp,int dummy,...)
214{
215 int error;
216 char * filename;
217 struct pt_regs *regs = (struct pt_regs *) ((unsigned char *)&dummy-4);
218
219 lock_kernel();
220 filename = getname(name);
221 error = PTR_ERR(filename);
222 if (IS_ERR(filename))
223 goto out;
224 error = do_execve(filename, argv, envp, regs);
225 putname(filename);
226out:
227 unlock_kernel();
228 return error;
229}
230
231unsigned long thread_saved_pc(struct task_struct *tsk)
232{
233 return ((struct pt_regs *)tsk->thread.esp0)->pc;
234}
235
236unsigned long get_wchan(struct task_struct *p)
237{
238 unsigned long fp, pc;
239 unsigned long stack_page;
240 int count = 0;
241 if (!p || p == current || p->state == TASK_RUNNING)
242 return 0;
243
244 stack_page = (unsigned long)p;
245 fp = ((struct pt_regs *)p->thread.ksp)->er6;
246 do {
247 if (fp < stack_page+sizeof(struct thread_info) ||
248 fp >= 8184+stack_page)
249 return 0;
250 pc = ((unsigned long *)fp)[1];
251 if (!in_sched_functions(pc))
252 return pc;
253 fp = *(unsigned long *) fp;
254 } while (count++ < 16);
255 return 0;
256}