/* $Id: process.c,v 1.28 2004/05/05 16:54:23 lethal Exp $ * *  linux/arch/sh/kernel/process.c * *  Copyright (C) 1995  Linus Torvalds * *  SuperH version:  Copyright (C) 1999, 2000  Niibe Yutaka & Kaz Kojima */ /* * This file handles the architecture-dependent parts of process handling.. */ #include <linux/module.h>#include <linux/unistd.h>#include <linux/mm.h>#include <linux/elfcore.h>#include <linux/a.out.h>#include <linux/slab.h>#include <linux/pm.h>#include <linux/ptrace.h>#include <linux/kallsyms.h>#include <linux/kexec.h> #include <asm/io.h>#include <asm/uaccess.h>#include <asm/mmu_context.h>#include <asm/elf.h> static int hlt_counter=0; int ubc_usercnt = 0; #define HARD_IDLE_TIMEOUT (HZ / 3) void (*pm_idle)(void); void (*pm_power_off)(void);EXPORT_SYMBOL(pm_power_off); void disable_hlt(void){	hlt_counter++;} EXPORT_SYMBOL(disable_hlt); void enable_hlt(void){	hlt_counter--;} EXPORT_SYMBOL(enable_hlt); void default_idle(void){	if (!hlt_counter)		cpu_sleep();	else		cpu_relax();} void cpu_idle(void){	/* endless idle loop with no priority at all */	while (1) {		void (*idle)(void) = pm_idle; 		if (!idle)			idle = default_idle; 		while (!need_resched())			idle(); 		preempt_enable_no_resched();		schedule();		preempt_disable();	}} void machine_restart(char * __unused){ #ifdef CONFIG_KEXEC	struct kimage *image;	image = xchg(&kexec_image, 0);	if (image) {		machine_shutdown();		machine_kexec(image);	}#endif 	/* SR.BL=1 and invoke address error to let CPU reset (manual reset) */	asm volatile("ldc %0, sr\n\t"		     "mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001));} void machine_halt(void){	local_irq_disable(); 	while (1)		cpu_sleep();} void machine_power_off(void){	if (pm_power_off)		pm_power_off();} void show_regs(struct pt_regs * regs){	printk("\n");	printk("Pid : %d, Comm: %20s\n", current->pid, current->comm);	print_symbol("PC is at %s\n", regs->pc);	printk("PC  : %08lx SP  : %08lx SR  : %08lx ",	       regs->pc, regs->regs[15], regs->sr);#ifdef CONFIG_MMU	printk("TEA : %08x    ", ctrl_inl(MMU_TEA));#else	printk("                  ");#endif	printk("%s\n", print_tainted()); 	printk("R0  : %08lx R1  : %08lx R2  : %08lx R3  : %08lx\n",	       regs->regs[0],regs->regs[1],	       regs->regs[2],regs->regs[3]);	printk("R4  : %08lx R5  : %08lx R6  : %08lx R7  : %08lx\n",	       regs->regs[4],regs->regs[5],	       regs->regs[6],regs->regs[7]);	printk("R8  : %08lx R9  : %08lx R10 : %08lx R11 : %08lx\n",	       regs->regs[8],regs->regs[9],	       regs->regs[10],regs->regs[11]);	printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",	       regs->regs[12],regs->regs[13],	       regs->regs[14]);	printk("MACH: %08lx MACL: %08lx GBR : %08lx PR  : %08lx\n",	       regs->mach, regs->macl, regs->gbr, regs->pr); 	/*	 * If we're in kernel mode, dump the stack too..	 */	if (!user_mode(regs)) {		extern void show_task(unsigned long *sp);		unsigned long sp = regs->regs[15]; 		show_task((unsigned long *)sp);	}} /* * Create a kernel thread */ /* * This is the mechanism for creating a new kernel thread. * */extern void kernel_thread_helper(void);__asm__(".align 5\n"	"kernel_thread_helper:\n\t"	"jsr	@r5\n\t"	" nop\n\t"	"mov.l	1f, r1\n\t"	"jsr	@r1\n\t"	" mov	r0, r4\n\t"	".align 2\n\t"	"1:.long do_exit"); int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags){	/* Don't use this in BL=1(cli).  Or else, CPU resets! */	struct pt_regs regs; 	memset(&regs, 0, sizeof(regs));	regs.regs[4] = (unsigned long) arg;	regs.regs[5] = (unsigned long) fn; 	regs.pc = (unsigned long) kernel_thread_helper;	regs.sr = (1 << 30); 	/* Ok, create the new process.. */	return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);} /* * Free current thread data structures etc.. */void exit_thread(void){	if (current->thread.ubc_pc) {		current->thread.ubc_pc = 0;		ubc_usercnt -= 1;	}} void flush_thread(void){#if defined(CONFIG_SH_FPU)	struct task_struct *tsk = current;	/* Forget lazy FPU state */	clear_fpu(tsk, task_pt_regs(tsk));	clear_used_math();#endif} void release_thread(struct task_struct *dead_task){	/* do nothing */} /* Fill in the fpu structure for a core dump.. */int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu){	int fpvalid = 0; #if defined(CONFIG_SH_FPU)	struct task_struct *tsk = current; 	fpvalid = !!tsk_used_math(tsk);	if (fpvalid) {		unlazy_fpu(tsk, regs);		memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));	}#endif 	return fpvalid;} /*  * Capture the user space registers if the task is not running (in user space) */int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs){	struct pt_regs ptregs;		ptregs = *task_pt_regs(tsk);	elf_core_copy_regs(regs, &ptregs); 	return 1;} intdump_task_fpu (struct task_struct *tsk, elf_fpregset_t *fpu){	int fpvalid = 0; #if defined(CONFIG_SH_FPU)	fpvalid = !!tsk_used_math(tsk);	if (fpvalid) {		unlazy_fpu(tsk, task_pt_regs(tsk));		memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));	}#endif 	return fpvalid;} asmlinkage void ret_from_fork(void); int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,		unsigned long unused,		struct task_struct *p, struct pt_regs *regs){	struct pt_regs *childregs;#if defined(CONFIG_SH_FPU)	struct task_struct *tsk = current; 	unlazy_fpu(tsk, regs);	p->thread.fpu = tsk->thread.fpu;	copy_to_stopped_child_used_math(p);#endif 	childregs = task_pt_regs(p);	*childregs = *regs; 	if (user_mode(regs)) {		childregs->regs[15] = usp;	} else {		childregs->regs[15] = (unsigned long)task_stack_page(p) + THREAD_SIZE;	}        if (clone_flags & CLONE_SETTLS) {		childregs->gbr = childregs->regs[0];	}	childregs->regs[0] = 0; /* Set return value for child */ 	p->thread.sp = (unsigned long) childregs;	p->thread.pc = (unsigned long) ret_from_fork; 	p->thread.ubc_pc = 0; 	return 0;} /* Tracing by user break controller.  */static voidubc_set_tracing(int asid, unsigned long pc){	ctrl_outl(pc, UBC_BARA); 	/* We don't have any ASID settings for the SH-2! */	if (cpu_data->type != CPU_SH7604)		ctrl_outb(asid, UBC_BASRA); 	ctrl_outl(0, UBC_BAMRA); 	if (cpu_data->type == CPU_SH7729) {		ctrl_outw(BBR_INST | BBR_READ | BBR_CPU, UBC_BBRA);		ctrl_outl(BRCR_PCBA | BRCR_PCTE, UBC_BRCR);	} else {		ctrl_outw(BBR_INST | BBR_READ, UBC_BBRA);		ctrl_outw(BRCR_PCBA, UBC_BRCR);	}} /* *	switch_to(x,y) should switch tasks from x to y. * */struct task_struct *__switch_to(struct task_struct *prev, struct task_struct *next){#if defined(CONFIG_SH_FPU)	unlazy_fpu(prev, task_pt_regs(prev));#endif #ifdef CONFIG_PREEMPT	{		unsigned long flags;		struct pt_regs *regs; 		local_irq_save(flags);		regs = task_pt_regs(prev);		if (user_mode(regs) && regs->regs[15] >= 0xc0000000) {			int offset = (int)regs->regs[15]; 			/* Reset stack pointer: clear critical region mark */			regs->regs[15] = regs->regs[1];			if (regs->pc < regs->regs[0])				/* Go to rewind point */				regs->pc = regs->regs[0] + offset;		}		local_irq_restore(flags);	}#endif 	/*	 * Restore the kernel mode register	 *   	k7 (r7_bank1)	 */	asm volatile("ldc	%0, r7_bank"		     : /* no output */		     : "r" (task_thread_info(next))); #ifdef CONFIG_MMU	/* If no tasks are using the UBC, we're done */	if (ubc_usercnt == 0)		/* If no tasks are using the UBC, we're done */;	else if (next->thread.ubc_pc && next->mm) {		ubc_set_tracing(next->mm->context & MMU_CONTEXT_ASID_MASK,				next->thread.ubc_pc);	} else {		ctrl_outw(0, UBC_BBRA);		ctrl_outw(0, UBC_BBRB);	}#endif 	return prev;} asmlinkage int sys_fork(unsigned long r4, unsigned long r5,			unsigned long r6, unsigned long r7,			struct pt_regs regs){#ifdef CONFIG_MMU	return do_fork(SIGCHLD, regs.regs[15], &regs, 0, NULL, NULL);#else	/* fork almost works, enough to trick you into looking elsewhere :-( */	return -EINVAL;#endif} asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,			 unsigned long parent_tidptr,			 unsigned long child_tidptr,			 struct pt_regs regs){	if (!newsp)		newsp = regs.regs[15];	return do_fork(clone_flags, newsp, &regs, 0,			(int __user *)parent_tidptr, (int __user *)child_tidptr);} /* * This is trivial, and on the face of it looks like it * could equally well be done in user mode. * * Not so, for quite unobvious reasons - register pressure. * In user mode vfork() cannot have a stack frame, and if * done by calling the "clone()" system call directly, you * do not have enough call-clobbered registers to hold all * the information you need. */asmlinkage int sys_vfork(unsigned long r4, unsigned long r5,			 unsigned long r6, unsigned long r7,			 struct pt_regs regs){	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs.regs[15], &regs,		       0, NULL, NULL);} /* * sys_execve() executes a new program. */asmlinkage int sys_execve(char *ufilename, char **uargv,			  char **uenvp, unsigned long r7,			  struct pt_regs regs){	int error;	char *filename; 	filename = getname((char __user *)ufilename);	error = PTR_ERR(filename);	if (IS_ERR(filename))		goto out; 	error = do_execve(filename,			  (char __user * __user *)uargv,			  (char __user * __user *)uenvp,			  &regs);	if (error == 0) {		task_lock(current);		current->ptrace &= ~PT_DTRACE;		task_unlock(current);	}	putname(filename);out:	return error;} unsigned long get_wchan(struct task_struct *p){	unsigned long schedule_frame;	unsigned long pc; 	if (!p || p == current || p->state == TASK_RUNNING)		return 0; 	/*	 * The same comment as on the Alpha applies here, too ...	 */	pc = thread_saved_pc(p);	if (in_sched_functions(pc)) {		schedule_frame = ((unsigned long *)(long)p->thread.sp)[1];		return (unsigned long)((unsigned long *)schedule_frame)[1];	}	return pc;} asmlinkage void break_point_trap(unsigned long r4, unsigned long r5,				 unsigned long r6, unsigned long r7,				 struct pt_regs regs){	/* Clear tracing.  */	ctrl_outw(0, UBC_BBRA);	ctrl_outw(0, UBC_BBRB);	current->thread.ubc_pc = 0;	ubc_usercnt -= 1; 	force_sig(SIGTRAP, current);} asmlinkage void break_point_trap_software(unsigned long r4, unsigned long r5,					  unsigned long r6, unsigned long r7,					  struct pt_regs regs){	regs.pc -= 2;	force_sig(SIGTRAP, current);}