/* * arch/sh/kernel/process.c * * This file handles the architecture-dependent parts of process handling.. * *  Copyright (C) 1995  Linus Torvalds * *  SuperH version:  Copyright (C) 1999, 2000  Niibe Yutaka & Kaz Kojima *		     Copyright (C) 2006 Lineo Solutions Inc. support SH4A UBC *		     Copyright (C) 2002 - 2008  Paul Mundt * * This file is subject to the terms and conditions of the GNU General Public * License.  See the file "COPYING" in the main directory of this archive * for more details. */#include <linux/module.h>#include <linux/mm.h>#include <linux/slab.h>#include <linux/elfcore.h>#include <linux/kallsyms.h>#include <linux/fs.h>#include <linux/ftrace.h>#include <linux/hw_breakpoint.h>#include <linux/prefetch.h>#include <asm/uaccess.h>#include <asm/mmu_context.h>#include <asm/system.h>#include <asm/fpu.h>#include <asm/syscalls.h> void show_regs(struct pt_regs * regs){	printk("\n");	printk("Pid : %d, Comm: \t\t%s\n", task_pid_nr(current), current->comm);	printk("CPU : %d        \t\t%s  (%s %.*s)\n\n",	       smp_processor_id(), print_tainted(), init_utsname()->release,	       (int)strcspn(init_utsname()->version, " "),	       init_utsname()->version); 	print_symbol("PC is at %s\n", instruction_pointer(regs));	print_symbol("PR is at %s\n", regs->pr); 	printk("PC  : %08lx SP  : %08lx SR  : %08lx ",	       regs->pc, regs->regs[15], regs->sr);#ifdef CONFIG_MMU	printk("TEA : %08x\n", __raw_readl(MMU_TEA));#else	printk("\n");#endif 	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); 	show_trace(NULL, (unsigned long *)regs->regs[15], regs);	show_code(regs);} /* * Create a kernel thread */ATTRIB_NORET void kernel_thread_helper(void *arg, int (*fn)(void *)){	do_exit(fn(arg));} /* Don't use this in BL=1(cli).  Or else, CPU resets! */int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags){	struct pt_regs regs;	int pid; 	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 = SR_MD;#if defined(CONFIG_SH_FPU)	regs.sr |= SR_FD;#endif 	/* Ok, create the new process.. */	pid = do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,		      &regs, 0, NULL, NULL); 	return pid;}EXPORT_SYMBOL(kernel_thread); void start_thread(struct pt_regs *regs, unsigned long new_pc,		  unsigned long new_sp){	regs->pr = 0;	regs->sr = SR_FD;	regs->pc = new_pc;	regs->regs[15] = new_sp; 	free_thread_xstate(current);}EXPORT_SYMBOL(start_thread); /* * Free current thread data structures etc.. */void exit_thread(void){} void flush_thread(void){	struct task_struct *tsk = current; 	flush_ptrace_hw_breakpoint(tsk); #if defined(CONFIG_SH_FPU)	/* 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)		fpvalid = !fpregs_get(tsk, NULL, 0,				      sizeof(struct user_fpu_struct),				      fpu, NULL);#endif 	return fpvalid;}EXPORT_SYMBOL(dump_fpu); /* * This gets called before we allocate a new thread and copy * the current task into it. */void prepare_to_copy(struct task_struct *tsk){	unlazy_fpu(tsk, task_pt_regs(tsk));} asmlinkage void ret_from_fork(void); int copy_thread(unsigned long clone_flags, unsigned long usp,		unsigned long unused,		struct task_struct *p, struct pt_regs *regs){	struct thread_info *ti = task_thread_info(p);	struct pt_regs *childregs; #if defined(CONFIG_SH_DSP)	struct task_struct *tsk = current; 	if (is_dsp_enabled(tsk)) {		/* We can use the __save_dsp or just copy the struct:		 * __save_dsp(p);		 * p->thread.dsp_status.status |= SR_DSP		 */		p->thread.dsp_status = tsk->thread.dsp_status;	}#endif 	childregs = task_pt_regs(p);	*childregs = *regs; 	if (user_mode(regs)) {		childregs->regs[15] = usp;		ti->addr_limit = USER_DS;	} else {		childregs->regs[15] = (unsigned long)childregs;		ti->addr_limit = KERNEL_DS;		ti->status &= ~TS_USEDFPU;		p->fpu_counter = 0;	} 	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; 	memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps)); 	return 0;} /* *	switch_to(x,y) should switch tasks from x to y. * */__notrace_funcgraph struct task_struct *__switch_to(struct task_struct *prev, struct task_struct *next){	struct thread_struct *next_t = &next->thread; 	unlazy_fpu(prev, task_pt_regs(prev)); 	/* we're going to use this soon, after a few expensive things */	if (next->fpu_counter > 5)		prefetch(next_t->xstate); #ifdef CONFIG_MMU	/*	 * Restore the kernel mode register	 *	k7 (r7_bank1)	 */	asm volatile("ldc	%0, r7_bank"		     : /* no output */		     : "r" (task_thread_info(next)));#endif 	/*	 * If the task has used fpu the last 5 timeslices, just do a full	 * restore of the math state immediately to avoid the trap; the	 * chances of needing FPU soon are obviously high now	 */	if (next->fpu_counter > 5)		__fpu_state_restore(); 	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	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);	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){	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);	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){	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);	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(const char __user *ufilename,			  const char __user *const __user *uargv,			  const char __user *const __user *uenvp,			  unsigned long r7, struct pt_regs __regs){	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);	int error;	char *filename; 	filename = getname(ufilename);	error = PTR_ERR(filename);	if (IS_ERR(filename))		goto out; 	error = do_execve(filename, uargv, uenvp, regs);	putname(filename);out:	return error;} unsigned long get_wchan(struct task_struct *p){	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); #ifdef CONFIG_FRAME_POINTER	if (in_sched_functions(pc)) {		unsigned long schedule_frame = (unsigned long)p->thread.sp;		return ((unsigned long *)schedule_frame)[21];	}#endif 	return pc;}