aboutsummaryrefslogtreecommitdiff
path: root/arch/h8300/kernel/process.c
blob: 97478138e361ad702308539b4d067543402df7cb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
/*
 *  linux/arch/h8300/kernel/process.c
 *
 * Yoshinori Sato <ysato@users.sourceforge.jp>
 *
 *  Based on:
 *
 *  linux/arch/m68knommu/kernel/process.c
 *
 *  Copyright (C) 1998  D. Jeff Dionne <jeff@ryeham.ee.ryerson.ca>,
 *                      Kenneth Albanowski <kjahds@kjahds.com>,
 *                      The Silver Hammer Group, Ltd.
 *
 *  linux/arch/m68k/kernel/process.c
 *
 *  Copyright (C) 1995  Hamish Macdonald
 *
 *  68060 fixes by Jesper Skov
 */

/*
 * This file handles the architecture-dependent parts of process handling..
 */

#include <linux/errno.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/interrupt.h>
#include <linux/reboot.h>
#include <linux/fs.h>
#include <linux/slab.h>

#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/traps.h>
#include <asm/setup.h>
#include <asm/pgtable.h>

void (*pm_power_off)(void) = NULL;
EXPORT_SYMBOL(pm_power_off);

asmlinkage void ret_from_fork(void);

/*
 * The idle loop on an H8/300..
 */
#if !defined(CONFIG_H8300H_SIM) && !defined(CONFIG_H8S_SIM)
static void default_idle(void)
{
	local_irq_disable();
	if (!need_resched()) {
		local_irq_enable();
		/* XXX: race here! What if need_resched() gets set now? */
		__asm__("sleep");
	} else
		local_irq_enable();
}
#else
static void default_idle(void)
{
	cpu_relax();
}
#endif
void (*idle)(void) = default_idle;

/*
 * The idle thread. There's no useful work to be
 * done, so just try to conserve power and have a
 * low exit latency (ie sit in a loop waiting for
 * somebody to say that they'd like to reschedule)
 */
void cpu_idle(void)
{
	while (1) {
		while (!need_resched())
			idle();
		preempt_enable_no_resched();
		schedule();
		preempt_disable();
	}
}

void machine_restart(char * __unused)
{
	local_irq_disable();
	__asm__("jmp @@0"); 
}

void machine_halt(void)
{
	local_irq_disable();
	__asm__("sleep");
	for (;;);
}

void machine_power_off(void)
{
	local_irq_disable();
	__asm__("sleep");
	for (;;);
}

void show_regs(struct pt_regs * regs)
{
	printk("\nPC: %08lx  Status: %02x",
	       regs->pc, regs->ccr);
	printk("\nORIG_ER0: %08lx ER0: %08lx ER1: %08lx",
	       regs->orig_er0, regs->er0, regs->er1);
	printk("\nER2: %08lx ER3: %08lx ER4: %08lx ER5: %08lx",
	       regs->er2, regs->er3, regs->er4, regs->er5);
	printk("\nER6' %08lx ",regs->er6);
	if (user_mode(regs))
		printk("USP: %08lx\n", rdusp());
	else
		printk("\n");
}

/*
 * Create a kernel thread
 */
int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
{
	long retval;
	long clone_arg;
	mm_segment_t fs;

	fs = get_fs();
	set_fs (KERNEL_DS);
	clone_arg = flags | CLONE_VM;
	__asm__("mov.l sp,er3\n\t"
		"sub.l er2,er2\n\t"
		"mov.l %2,er1\n\t"
		"mov.l %1,er0\n\t"
		"trapa #0\n\t"
		"cmp.l sp,er3\n\t"
		"beq 1f\n\t"
		"mov.l %4,er0\n\t"
		"mov.l %3,er1\n\t"
		"jsr @er1\n\t"
		"mov.l %5,er0\n\t"
		"trapa #0\n"
		"1:\n\t"
		"mov.l er0,%0"
		:"=r"(retval)
		:"i"(__NR_clone),"g"(clone_arg),"g"(fn),"g"(arg),"i"(__NR_exit)
		:"er0","er1","er2","er3");
	set_fs (fs);
	return retval;
}

void flush_thread(void)
{
}

/*
 * "h8300_fork()".. By the time we get here, the
 * non-volatile registers have also been saved on the
 * stack. We do some ugly pointer stuff here.. (see
 * also copy_thread)
 */

asmlinkage int h8300_fork(struct pt_regs *regs)
{
	return -EINVAL;
}

asmlinkage int h8300_vfork(struct pt_regs *regs)
{
	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL, NULL);
}

asmlinkage int h8300_clone(struct pt_regs *regs)
{
	unsigned long clone_flags;
	unsigned long newsp;

	/* syscall2 puts clone_flags in er1 and usp in er2 */
	clone_flags = regs->er1;
	newsp = regs->er2;
	if (!newsp)
		newsp  = rdusp();
	return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);

}

int copy_thread(unsigned long clone_flags,
                unsigned long usp, unsigned long topstk,
		 struct task_struct * p, struct pt_regs * regs)
{
	struct pt_regs * childregs;

	childregs = (struct pt_regs *) (THREAD_SIZE + task_stack_page(p)) - 1;

	*childregs = *regs;
	childregs->retpc = (unsigned long) ret_from_fork;
	childregs->er0 = 0;

	p->thread.usp = usp;
	p->thread.ksp = (unsigned long)childregs;

	return 0;
}

/*
 * sys_execve() executes a new program.
 */
asmlinkage int sys_execve(const char *name,
			  const char *const *argv,
			  const char *const *envp,
			  int dummy, ...)
{
	int error;
	char * filename;
	struct pt_regs *regs = (struct pt_regs *) ((unsigned char *)&dummy-4);

	filename = getname(name);
	error = PTR_ERR(filename);
	if (IS_ERR(filename))
		return error;
	error = do_execve(filename, argv, envp, regs);
	putname(filename);
	return error;
}

unsigned long thread_saved_pc(struct task_struct *tsk)
{
	return ((struct pt_regs *)tsk->thread.esp0)->pc;
}

unsigned long get_wchan(struct task_struct *p)
{
	unsigned long fp, pc;
	unsigned long stack_page;
	int count = 0;
	if (!p || p == current || p->state == TASK_RUNNING)
		return 0;

	stack_page = (unsigned long)p;
	fp = ((struct pt_regs *)p->thread.ksp)->er6;
	do {
		if (fp < stack_page+sizeof(struct thread_info) ||
		    fp >= 8184+stack_page)
			return 0;
		pc = ((unsigned long *)fp)[1];
		if (!in_sched_functions(pc))
			return pc;
		fp = *(unsigned long *) fp;
	} while (count++ < 16);
	return 0;
}