1#ifdef CONFIG_MMU
2#include "process_mm.c"
3#else
4#include "process_no.c"
5#endif

  1/*
  2 *  linux/arch/m68k/kernel/process.c
  3 *
  4 *  Copyright (C) 1995  Hamish Macdonald
  5 *
  6 *  68060 fixes by Jesper Skov
  7 */
  8
  9/*
 10 * This file handles the architecture-dependent parts of process handling..
 11 */
 12
 13#include <linux/errno.h>
 14#include <linux/module.h>
 15#include <linux/sched.h>
 16#include <linux/kernel.h>
 17#include <linux/mm.h>
 18#include <linux/slab.h>
 19#include <linux/fs.h>
 20#include <linux/smp.h>
 21#include <linux/stddef.h>
 22#include <linux/unistd.h>
 23#include <linux/ptrace.h>
 24#include <linux/user.h>
 25#include <linux/reboot.h>
 26#include <linux/init_task.h>
 27#include <linux/mqueue.h>
 28
 29#include <asm/uaccess.h>
 30#include <asm/traps.h>
 31#include <asm/machdep.h>
 32#include <asm/setup.h>
 33#include <asm/pgtable.h>
 34
 35
 36asmlinkage void ret_from_fork(void);
 37
 38
 39/*
 40 * Return saved PC from a blocked thread
 41 */
 42unsigned long thread_saved_pc(struct task_struct *tsk)
 43{
 44	struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp;
 45	/* Check whether the thread is blocked in resume() */
 46	if (in_sched_functions(sw->retpc))
 47		return ((unsigned long *)sw->a6)[1];
 48	else
 49		return sw->retpc;
 50}
 51
 52/*
 53 * The idle loop on an m68k..
 54 */
 55static void default_idle(void)
 56{
 57	if (!need_resched())
 58#if defined(MACH_ATARI_ONLY)
 59		/* block out HSYNC on the atari (falcon) */
 60		__asm__("stop #0x2200" : : : "cc");
 61#else
 62		__asm__("stop #0x2000" : : : "cc");
 63#endif
 64}
 65
 66void (*idle)(void) = default_idle;
 67
 68/*
 69 * The idle thread. There's no useful work to be
 70 * done, so just try to conserve power and have a
 71 * low exit latency (ie sit in a loop waiting for
 72 * somebody to say that they'd like to reschedule)
 73 */
 74void cpu_idle(void)
 75{
 76	/* endless idle loop with no priority at all */
 77	while (1) {
 78		while (!need_resched())
 79			idle();
 80		schedule_preempt_disabled();
 81	}
 82}
 83
 84void machine_restart(char * __unused)
 85{
 86	if (mach_reset)
 87		mach_reset();
 88	for (;;);
 89}
 90
 91void machine_halt(void)
 92{
 93	if (mach_halt)
 94		mach_halt();
 95	for (;;);
 96}
 97
 98void machine_power_off(void)
 99{
100	if (mach_power_off)
101		mach_power_off();
102	for (;;);
103}
104
105void (*pm_power_off)(void) = machine_power_off;
106EXPORT_SYMBOL(pm_power_off);
107
108void show_regs(struct pt_regs * regs)
109{
110	printk("\n");
111	printk("Format %02x  Vector: %04x  PC: %08lx  Status: %04x    %s\n",
112	       regs->format, regs->vector, regs->pc, regs->sr, print_tainted());
113	printk("ORIG_D0: %08lx  D0: %08lx  A2: %08lx  A1: %08lx\n",
114	       regs->orig_d0, regs->d0, regs->a2, regs->a1);
115	printk("A0: %08lx  D5: %08lx  D4: %08lx\n",
116	       regs->a0, regs->d5, regs->d4);
117	printk("D3: %08lx  D2: %08lx  D1: %08lx\n",
118	       regs->d3, regs->d2, regs->d1);
119	if (!(regs->sr & PS_S))
120		printk("USP: %08lx\n", rdusp());
121}
122
123/*
124 * Create a kernel thread
125 */
126int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
127{
128	int pid;
129	mm_segment_t fs;
130
131	fs = get_fs();
132	set_fs (KERNEL_DS);
133
134	{
135	register long retval __asm__ ("d0");
136	register long clone_arg __asm__ ("d1") = flags | CLONE_VM | CLONE_UNTRACED;
137
138	retval = __NR_clone;
139	__asm__ __volatile__
140	  ("clrl %%d2\n\t"
141	   "trap #0\n\t"		/* Linux/m68k system call */
142	   "tstl %0\n\t"		/* child or parent */
143	   "jne 1f\n\t"			/* parent - jump */
144#ifdef CONFIG_MMU
145	   "lea %%sp@(%c7),%6\n\t"	/* reload current */
146	   "movel %6@,%6\n\t"
147#endif
148	   "movel %3,%%sp@-\n\t"	/* push argument */
149	   "jsr %4@\n\t"		/* call fn */
150	   "movel %0,%%d1\n\t"		/* pass exit value */
151	   "movel %2,%%d0\n\t"		/* exit */
152	   "trap #0\n"
153	   "1:"
154	   : "+d" (retval)
155	   : "i" (__NR_clone), "i" (__NR_exit),
156	     "r" (arg), "a" (fn), "d" (clone_arg), "r" (current),
157	     "i" (-THREAD_SIZE)
158	   : "d2");
159
160	pid = retval;
161	}
162
163	set_fs (fs);
164	return pid;
165}
166EXPORT_SYMBOL(kernel_thread);
167
168void flush_thread(void)
169{
170	current->thread.fs = __USER_DS;
171#ifdef CONFIG_FPU
172	if (!FPU_IS_EMU) {
173		unsigned long zero = 0;
174		asm volatile("frestore %0": :"m" (zero));
175	}
176#endif
177}
178
179/*
180 * "m68k_fork()".. By the time we get here, the
181 * non-volatile registers have also been saved on the
182 * stack. We do some ugly pointer stuff here.. (see
183 * also copy_thread)
184 */
185
186asmlinkage int m68k_fork(struct pt_regs *regs)
187{
188#ifdef CONFIG_MMU
189	return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL);
190#else
191	return -EINVAL;
192#endif
193}
194
195asmlinkage int m68k_vfork(struct pt_regs *regs)
196{
197	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0,
198		       NULL, NULL);
199}
200
201asmlinkage int m68k_clone(struct pt_regs *regs)
202{
203	unsigned long clone_flags;
204	unsigned long newsp;
205	int __user *parent_tidptr, *child_tidptr;
206
207	/* syscall2 puts clone_flags in d1 and usp in d2 */
208	clone_flags = regs->d1;
209	newsp = regs->d2;
210	parent_tidptr = (int __user *)regs->d3;
211	child_tidptr = (int __user *)regs->d4;
212	if (!newsp)
213		newsp = rdusp();
214	return do_fork(clone_flags, newsp, regs, 0,
215		       parent_tidptr, child_tidptr);
216}
217
218int copy_thread(unsigned long clone_flags, unsigned long usp,
219		 unsigned long unused,
220		 struct task_struct * p, struct pt_regs * regs)
221{
222	struct pt_regs * childregs;
223	struct switch_stack * childstack, *stack;
224	unsigned long *retp;
225
226	childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
227
228	*childregs = *regs;
229	childregs->d0 = 0;
230
231	retp = ((unsigned long *) regs);
232	stack = ((struct switch_stack *) retp) - 1;
233
234	childstack = ((struct switch_stack *) childregs) - 1;
235	*childstack = *stack;
236	childstack->retpc = (unsigned long)ret_from_fork;
237
238	p->thread.usp = usp;
239	p->thread.ksp = (unsigned long)childstack;
240
241	if (clone_flags & CLONE_SETTLS)
242		task_thread_info(p)->tp_value = regs->d5;
243
244	/*
245	 * Must save the current SFC/DFC value, NOT the value when
246	 * the parent was last descheduled - RGH  10-08-96
247	 */
248	p->thread.fs = get_fs().seg;
249
250#ifdef CONFIG_FPU
251	if (!FPU_IS_EMU) {
252		/* Copy the current fpu state */
253		asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
254
255		if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) {
256			if (CPU_IS_COLDFIRE) {
257				asm volatile ("fmovemd %/fp0-%/fp7,%0\n\t"
258					      "fmovel %/fpiar,%1\n\t"
259					      "fmovel %/fpcr,%2\n\t"
260					      "fmovel %/fpsr,%3"
261					      :
262					      : "m" (p->thread.fp[0]),
263						"m" (p->thread.fpcntl[0]),
264						"m" (p->thread.fpcntl[1]),
265						"m" (p->thread.fpcntl[2])
266					      : "memory");
267			} else {
268				asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
269					      "fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
270					      :
271					      : "m" (p->thread.fp[0]),
272						"m" (p->thread.fpcntl[0])
273					      : "memory");
274			}
275		}
276
277		/* Restore the state in case the fpu was busy */
278		asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
279	}
280#endif /* CONFIG_FPU */
281
282	return 0;
283}
284
285/* Fill in the fpu structure for a core dump.  */
286#ifdef CONFIG_FPU
287int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu)
288{
289	char fpustate[216];
290
291	if (FPU_IS_EMU) {
292		int i;
293
294		memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
295		memcpy(fpu->fpregs, current->thread.fp, 96);
296		/* Convert internal fpu reg representation
297		 * into long double format
298		 */
299		for (i = 0; i < 24; i += 3)
300			fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
301			                 ((fpu->fpregs[i] & 0x0000ffff) << 16);
302		return 1;
303	}
304
305	/* First dump the fpu context to avoid protocol violation.  */
306	asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
307	if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2])
308		return 0;
309
310	if (CPU_IS_COLDFIRE) {
311		asm volatile ("fmovel %/fpiar,%0\n\t"
312			      "fmovel %/fpcr,%1\n\t"
313			      "fmovel %/fpsr,%2\n\t"
314			      "fmovemd %/fp0-%/fp7,%3"
315			      :
316			      : "m" (fpu->fpcntl[0]),
317				"m" (fpu->fpcntl[1]),
318				"m" (fpu->fpcntl[2]),
319				"m" (fpu->fpregs[0])
320			      : "memory");
321	} else {
322		asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
323			      :
324			      : "m" (fpu->fpcntl[0])
325			      : "memory");
326		asm volatile ("fmovemx %/fp0-%/fp7,%0"
327			      :
328			      : "m" (fpu->fpregs[0])
329			      : "memory");
330	}
331
332	return 1;
333}
334EXPORT_SYMBOL(dump_fpu);
335#endif /* CONFIG_FPU */
336
337/*
338 * sys_execve() executes a new program.
339 */
340asmlinkage int sys_execve(const char __user *name,
341			  const char __user *const __user *argv,
342			  const char __user *const __user *envp)
343{
344	int error;
345	char * filename;
346	struct pt_regs *regs = (struct pt_regs *) &name;
347
348	filename = getname(name);
349	error = PTR_ERR(filename);
350	if (IS_ERR(filename))
351		return error;
352	error = do_execve(filename, argv, envp, regs);
353	putname(filename);
354	return error;
355}
356
357unsigned long get_wchan(struct task_struct *p)
358{
359	unsigned long fp, pc;
360	unsigned long stack_page;
361	int count = 0;
362	if (!p || p == current || p->state == TASK_RUNNING)
363		return 0;
364
365	stack_page = (unsigned long)task_stack_page(p);
366	fp = ((struct switch_stack *)p->thread.ksp)->a6;
367	do {
368		if (fp < stack_page+sizeof(struct thread_info) ||
369		    fp >= 8184+stack_page)
370			return 0;
371		pc = ((unsigned long *)fp)[1];
372		if (!in_sched_functions(pc))
373			return pc;
374		fp = *(unsigned long *) fp;
375	} while (count++ < 16);
376	return 0;
377}