aboutsummaryrefslogtreecommitdiffstats
path: root/arch/m68knommu/kernel/process.c
blob: 959cb249c759fd4cae926a49259a67c9893fac34 (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
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
/*
 *  linux/arch/m68knommu/kernel/process.c
 *
 *  Copyright (C) 1995  Hamish Macdonald
 *
 *  68060 fixes by Jesper Skov
 *
 *  uClinux changes
 *  Copyright (C) 2000-2002, David McCullough <davidm@snapgear.com>
 */

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

#include <linux/module.h>
#include <linux/errno.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/slab.h>
#include <linux/user.h>
#include <linux/interrupt.h>
#include <linux/reboot.h>
#include <linux/fs.h>

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

asmlinkage void ret_from_fork(void);

/*
 * The following aren't currently used.
 */
void (*pm_idle)(void);
EXPORT_SYMBOL(pm_idle);

void (*pm_power_off)(void);
EXPORT_SYMBOL(pm_power_off);

/*
 * The idle loop on an m68knommu..
 */
static void default_idle(void)
{
	local_irq_disable();
 	while (!need_resched()) {
		/* This stop will re-enable interrupts */
 		__asm__("stop #0x2000" : : : "cc");
		local_irq_disable();
	}
	local_irq_enable();
}

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)
{
	/* endless idle loop with no priority at all */
	while (1) {
		idle();
		preempt_enable_no_resched();
		schedule();
		preempt_disable();
	}
}

void machine_restart(char * __unused)
{
	if (mach_reset)
		mach_reset();
	for (;;);
}

void machine_halt(void)
{
	if (mach_halt)
		mach_halt();
	for (;;);
}

void machine_power_off(void)
{
	if (mach_power_off)
		mach_power_off();
	for (;;);
}

void show_regs(struct pt_regs * regs)
{
	printk(KERN_NOTICE "\n");
	printk(KERN_NOTICE "Format %02x  Vector: %04x  PC: %08lx  Status: %04x    %s\n",
	       regs->format, regs->vector, regs->pc, regs->sr, print_tainted());
	printk(KERN_NOTICE "ORIG_D0: %08lx  D0: %08lx  A2: %08lx  A1: %08lx\n",
	       regs->orig_d0, regs->d0, regs->a2, regs->a1);
	printk(KERN_NOTICE "A0: %08lx  D5: %08lx  D4: %08lx\n",
	       regs->a0, regs->d5, regs->d4);
	printk(KERN_NOTICE "D3: %08lx  D2: %08lx  D1: %08lx\n",
	       regs->d3, regs->d2, regs->d1);
	if (!(regs->sr & PS_S))
		printk(KERN_NOTICE "USP: %08lx\n", rdusp());
}

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

	fs = get_fs();
	set_fs(KERNEL_DS);

	__asm__ __volatile__ (
			"movel	%%sp, %%d2\n\t"
			"movel	%5, %%d1\n\t"
			"movel	%1, %%d0\n\t"
			"trap	#0\n\t"
			"cmpl	%%sp, %%d2\n\t"
			"jeq	1f\n\t"
			"movel	%3, %%sp@-\n\t"
			"jsr	%4@\n\t"
			"movel	%2, %%d0\n\t"
			"trap	#0\n"
			"1:\n\t"
			"movel	%%d0, %0\n"
		: "=d" (retval)
		: "i" (__NR_clone),
		  "i" (__NR_exit),
		  "a" (arg),
		  "a" (fn),
		  "a" (clone_arg)
		: "cc", "%d0", "%d1", "%d2");

	set_fs(fs);
	return retval;
}

void flush_thread(void)
{
#ifdef CONFIG_FPU
	unsigned long zero = 0;
#endif
	set_fs(USER_DS);
	current->thread.fs = __USER_DS;
#ifdef CONFIG_FPU
	if (!FPU_IS_EMU)
		asm volatile (".chip 68k/68881\n\t"
			      "frestore %0@\n\t"
			      ".chip 68k" : : "a" (&zero));
#endif
}

/*
 * "m68k_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 m68k_fork(struct pt_regs *regs)
{
	/* fork almost works, enough to trick you into looking elsewhere :-( */
	return(-EINVAL);
}

asmlinkage int m68k_vfork(struct pt_regs *regs)
{
	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL, NULL);
}

asmlinkage int m68k_clone(struct pt_regs *regs)
{
	unsigned long clone_flags;
	unsigned long newsp;

	/* syscall2 puts clone_flags in d1 and usp in d2 */
	clone_flags = regs->d1;
	newsp = regs->d2;
	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;
	struct switch_stack * childstack, *stack;
	unsigned long *retp;

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

	*childregs = *regs;
	childregs->d0 = 0;

	retp = ((unsigned long *) regs);
	stack = ((struct switch_stack *) retp) - 1;

	childstack = ((struct switch_stack *) childregs) - 1;
	*childstack = *stack;
	childstack->retpc = (unsigned long)ret_from_fork;

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

	if (clone_flags & CLONE_SETTLS)
		task_thread_info(p)->tp_value = regs->d5;

	/*
	 * Must save the current SFC/DFC value, NOT the value when
	 * the parent was last descheduled - RGH  10-08-96
	 */
	p->thread.fs = get_fs().seg;

#ifdef CONFIG_FPU
	if (!FPU_IS_EMU) {
		/* Copy the current fpu state */
		asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");

		if (p->thread.fpstate[0])
		  asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
				"fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
				: : "m" (p->thread.fp[0]), "m" (p->thread.fpcntl[0])
				: "memory");
		/* Restore the state in case the fpu was busy */
		asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
	}
#endif

	return 0;
}

/* Fill in the fpu structure for a core dump.  */

int dump_fpu(struct pt_regs *regs, struct user_m68kfp_struct *fpu)
{
#ifdef CONFIG_FPU
	char fpustate[216];

	if (FPU_IS_EMU) {
		int i;

		memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
		memcpy(fpu->fpregs, current->thread.fp, 96);
		/* Convert internal fpu reg representation
		 * into long double format
		 */
		for (i = 0; i < 24; i += 3)
			fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
			                 ((fpu->fpregs[i] & 0x0000ffff) << 16);
		return 1;
	}

	/* First dump the fpu context to avoid protocol violation.  */
	asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
	if (!fpustate[0])
		return 0;

	asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
		:: "m" (fpu->fpcntl[0])
		: "memory");
	asm volatile ("fmovemx %/fp0-%/fp7,%0"
		:: "m" (fpu->fpregs[0])
		: "memory");
#endif
	return 1;
}

/*
 *	Generic dumping code. Used for panic and debug.
 */
void dump(struct pt_regs *fp)
{
	unsigned long	*sp;
	unsigned char	*tp;
	int		i;

	printk(KERN_EMERG "\nCURRENT PROCESS:\n\n");
	printk(KERN_EMERG "COMM=%s PID=%d\n", current->comm, current->pid);

	if (current->mm) {
		printk(KERN_EMERG "TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
			(int) current->mm->start_code,
			(int) current->mm->end_code,
			(int) current->mm->start_data,
			(int) current->mm->end_data,
			(int) current->mm->end_data,
			(int) current->mm->brk);
		printk(KERN_EMERG "USER-STACK=%08x KERNEL-STACK=%08x\n\n",
			(int) current->mm->start_stack,
			(int)(((unsigned long) current) + THREAD_SIZE));
	}

	printk(KERN_EMERG "PC: %08lx\n", fp->pc);
	printk(KERN_EMERG "SR: %08lx    SP: %08lx\n", (long) fp->sr, (long) fp);
	printk(KERN_EMERG "d0: %08lx    d1: %08lx    d2: %08lx    d3: %08lx\n",
		fp->d0, fp->d1, fp->d2, fp->d3);
	printk(KERN_EMERG "d4: %08lx    d5: %08lx    a0: %08lx    a1: %08lx\n",
		fp->d4, fp->d5, fp->a0, fp->a1);
	printk(KERN_EMERG "\nUSP: %08x   TRAPFRAME: %08x\n",
		(unsigned int) rdusp(), (unsigned int) fp);

	printk(KERN_EMERG "\nCODE:");
	tp = ((unsigned char *) fp->pc) - 0x20;
	for (sp = (unsigned long *) tp, i = 0; (i < 0x40);  i += 4) {
		if ((i % 0x10) == 0)
			printk(KERN_EMERG "%08x: ", (int) (tp + i));
		printk("%08x ", (int) *sp++);
	}
	printk(KERN_EMERG "\n");

	printk(KERN_EMERG "KERNEL STACK:");
	tp = ((unsigned char *) fp) - 0x40;
	for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) {
		if ((i % 0x10) == 0)
			printk(KERN_EMERG "%08x: ", (int) (tp + i));
		printk("%08x ", (int) *sp++);
	}
	printk(KERN_EMERG "\n");

	printk(KERN_EMERG "USER STACK:");
	tp = (unsigned char *) (rdusp() - 0x10);
	for (sp = (unsigned long *) tp, i = 0; (i < 0x80); i += 4) {
		if ((i % 0x10) == 0)
			printk(KERN_EMERG "%08x: ", (int) (tp + i));
		printk("%08x ", (int) *sp++);
	}
	printk(KERN_EMERG "\n");
}

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

	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 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 switch_stack *)p->thread.ksp)->a6;
	do {
		if (fp < stack_page+sizeof(struct thread_info) ||
		    fp >= THREAD_SIZE-8+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;
}

/*
 * Return saved PC of a blocked thread.
 */
unsigned long thread_saved_pc(struct task_struct *tsk)
{
	struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp;

	/* Check whether the thread is blocked in resume() */
	if (in_sched_functions(sw->retpc))
		return ((unsigned long *)sw->a6)[1];
	else
		return sw->retpc;
}