/* *  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/slab.h>#include <linux/fs.h>#include <linux/smp.h>#include <linux/stddef.h>#include <linux/unistd.h>#include <linux/ptrace.h>#include <linux/user.h>#include <linux/reboot.h>#include <linux/init_task.h>#include <linux/mqueue.h> #include <asm/uaccess.h>#include <asm/traps.h>#include <asm/machdep.h>#include <asm/setup.h>#include <asm/pgtable.h>  asmlinkage void ret_from_fork(void);  /* * Return saved PC from 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;} /* * The idle loop on an m68k.. */static void default_idle(void){	if (!need_resched())#if defined(MACH_ATARI_ONLY)		/* block out HSYNC on the atari (falcon) */		__asm__("stop #0x2200" : : : "cc");#else		__asm__("stop #0x2000" : : : "cc");#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){	/* endless idle loop with no priority at all */	while (1) {		while (!need_resched())			idle();		schedule_preempt_disabled();	}} 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 (*pm_power_off)(void) = machine_power_off;EXPORT_SYMBOL(pm_power_off); void show_regs(struct pt_regs * regs){	printk("\n");	printk("Format %02x  Vector: %04x  PC: %08lx  Status: %04x    %s\n",	       regs->format, regs->vector, regs->pc, regs->sr, print_tainted());	printk("ORIG_D0: %08lx  D0: %08lx  A2: %08lx  A1: %08lx\n",	       regs->orig_d0, regs->d0, regs->a2, regs->a1);	printk("A0: %08lx  D5: %08lx  D4: %08lx\n",	       regs->a0, regs->d5, regs->d4);	printk("D3: %08lx  D2: %08lx  D1: %08lx\n",	       regs->d3, regs->d2, regs->d1);	if (!(regs->sr & PS_S))		printk("USP: %08lx\n", rdusp());} /* * Create a kernel thread */int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags){	int pid;	mm_segment_t fs; 	fs = get_fs();	set_fs (KERNEL_DS); 	{	register long retval __asm__ ("d0");	register long clone_arg __asm__ ("d1") = flags | CLONE_VM | CLONE_UNTRACED; 	retval = __NR_clone;	__asm__ __volatile__	  ("clrl %%d2\n\t"	   "trap #0\n\t"		/* Linux/m68k system call */	   "tstl %0\n\t"		/* child or parent */	   "jne 1f\n\t"			/* parent - jump */#ifdef CONFIG_MMU	   "lea %%sp@(%c7),%6\n\t"	/* reload current */	   "movel %6@,%6\n\t"#endif	   "movel %3,%%sp@-\n\t"	/* push argument */	   "jsr %4@\n\t"		/* call fn */	   "movel %0,%%d1\n\t"		/* pass exit value */	   "movel %2,%%d0\n\t"		/* exit */	   "trap #0\n"	   "1:"	   : "+d" (retval)	   : "i" (__NR_clone), "i" (__NR_exit),	     "r" (arg), "a" (fn), "d" (clone_arg), "r" (current),	     "i" (-THREAD_SIZE)	   : "d2"); 	pid = retval;	} 	set_fs (fs);	return pid;}EXPORT_SYMBOL(kernel_thread); void flush_thread(void){	current->thread.fs = __USER_DS;#ifdef CONFIG_FPU	if (!FPU_IS_EMU) {		unsigned long zero = 0;		asm volatile("frestore %0": :"m" (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){#ifdef CONFIG_MMU	return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL);#else	return -EINVAL;#endif} 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;	int __user *parent_tidptr, *child_tidptr; 	/* syscall2 puts clone_flags in d1 and usp in d2 */	clone_flags = regs->d1;	newsp = regs->d2;	parent_tidptr = (int __user *)regs->d3;	child_tidptr = (int __user *)regs->d4;	if (!newsp)		newsp = rdusp();	return do_fork(clone_flags, newsp, regs, 0,		       parent_tidptr, child_tidptr);} int copy_thread(unsigned long clone_flags, unsigned long usp,		 unsigned long unused,		 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 (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) {			if (CPU_IS_COLDFIRE) {				asm volatile ("fmovemd %/fp0-%/fp7,%0\n\t"					      "fmovel %/fpiar,%1\n\t"					      "fmovel %/fpcr,%2\n\t"					      "fmovel %/fpsr,%3"					      :					      : "m" (p->thread.fp[0]),						"m" (p->thread.fpcntl[0]),						"m" (p->thread.fpcntl[1]),						"m" (p->thread.fpcntl[2])					      : "memory");			} else {				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 /* CONFIG_FPU */ 	return 0;} /* Fill in the fpu structure for a core dump.  */#ifdef CONFIG_FPUint dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *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 (!CPU_IS_060 ? !fpustate[0] : !fpustate[2])		return 0; 	if (CPU_IS_COLDFIRE) {		asm volatile ("fmovel %/fpiar,%0\n\t"			      "fmovel %/fpcr,%1\n\t"			      "fmovel %/fpsr,%2\n\t"			      "fmovemd %/fp0-%/fp7,%3"			      :			      : "m" (fpu->fpcntl[0]),				"m" (fpu->fpcntl[1]),				"m" (fpu->fpcntl[2]),				"m" (fpu->fpregs[0])			      : "memory");	} else {		asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"			      :			      : "m" (fpu->fpcntl[0])			      : "memory");		asm volatile ("fmovemx %/fp0-%/fp7,%0"			      :			      : "m" (fpu->fpregs[0])			      : "memory");	} 	return 1;}EXPORT_SYMBOL(dump_fpu);#endif /* CONFIG_FPU */ /* * sys_execve() executes a new program. */asmlinkage int sys_execve(const char __user *name,			  const char __user *const __user *argv,			  const char __user *const __user *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)task_stack_page(p);	fp = ((struct switch_stack *)p->thread.ksp)->a6;	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;}