/* *  Port on Texas Instruments TMS320C6x architecture * *  Copyright (C) 2004, 2006, 2009, 2010, 2011 Texas Instruments Incorporated *  Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com) * *  This program is free software; you can redistribute it and/or modify *  it under the terms of the GNU General Public License version 2 as *  published by the Free Software Foundation. * */#include <linux/module.h>#include <linux/unistd.h>#include <linux/ptrace.h>#include <linux/init_task.h>#include <linux/tick.h>#include <linux/mqueue.h>#include <linux/syscalls.h>#include <linux/reboot.h> #include <asm/syscalls.h> /* hooks for board specific support */void	(*c6x_restart)(void);void	(*c6x_halt)(void); extern asmlinkage void ret_from_fork(void); /* * power off function, if any */void (*pm_power_off)(void);EXPORT_SYMBOL(pm_power_off); static void c6x_idle(void){	unsigned long tmp; 	/*	 * Put local_irq_enable and idle in same execute packet	 * to make them atomic and avoid race to idle with	 * interrupts enabled.	 */	asm volatile ("   mvc .s2 CSR,%0\n"		      "   or  .d2 1,%0,%0\n"		      "   mvc .s2 %0,CSR\n"		      "|| idle\n"		      : "=b"(tmp));} /* * The idle loop for C64x */void cpu_idle(void){	/* endless idle loop with no priority at all */	while (1) {		tick_nohz_idle_enter();		rcu_idle_enter();		while (1) {			local_irq_disable();			if (need_resched()) {				local_irq_enable();				break;			}			c6x_idle(); /* enables local irqs */		}		rcu_idle_exit();		tick_nohz_idle_exit(); 		preempt_enable_no_resched();		schedule();		preempt_disable();	}} static void halt_loop(void){	printk(KERN_EMERG "System Halted, OK to turn off power\n");	local_irq_disable();	while (1)		asm volatile("idle\n");} void machine_restart(char *__unused){	if (c6x_restart)		c6x_restart();	halt_loop();} void machine_halt(void){	if (c6x_halt)		c6x_halt();	halt_loop();} void machine_power_off(void){	if (pm_power_off)		pm_power_off();	halt_loop();} static void kernel_thread_helper(int dummy, void *arg, int (*fn)(void *)){	do_exit(fn(arg));} /* * Create a kernel thread */int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags){	struct pt_regs regs; 	/*	 * copy_thread sets a4 to zero (child return from fork)	 * so we can't just set things up to directly return to	 * fn.	 */	memset(&regs, 0, sizeof(regs));	regs.b4 = (unsigned long) arg;	regs.a6 = (unsigned long) fn;	regs.pc = (unsigned long) kernel_thread_helper;	local_save_flags(regs.csr);	regs.csr |= 1;	regs.tsr = 5; /* Set GEE and GIE in TSR */ 	/* Ok, create the new process.. */	return do_fork(flags | CLONE_VM | CLONE_UNTRACED, -1, &regs,		       0, NULL, NULL);}EXPORT_SYMBOL(kernel_thread); void flush_thread(void){} void exit_thread(void){} SYSCALL_DEFINE1(c6x_clone, struct pt_regs *, regs){	unsigned long clone_flags;	unsigned long newsp; 	/* syscall puts clone_flags in A4 and usp in B4 */	clone_flags = regs->orig_a4;	if (regs->b4)		newsp = regs->b4;	else		newsp = regs->sp; 	return do_fork(clone_flags, newsp, regs, 0, (int __user *)regs->a6,		       (int __user *)regs->b6);} /* * Do necessary setup to start up a newly executed thread. */void start_thread(struct pt_regs *regs, unsigned int pc, unsigned long usp){	/*	 * The binfmt loader will setup a "full" stack, but the C6X	 * operates an "empty" stack. So we adjust the usp so that	 * argc doesn't get destroyed if an interrupt is taken before	 * it is read from the stack.	 *	 * NB: Library startup code needs to match this.	 */	usp -= 8; 	set_fs(USER_DS);	regs->pc  = pc;	regs->sp  = usp;	regs->tsr |= 0x40; /* set user mode */	current->thread.usp = usp;} /* * Copy a new thread context in its stack. */int copy_thread(unsigned long clone_flags, unsigned long usp,		unsigned long ustk_size,		struct task_struct *p, struct pt_regs *regs){	struct pt_regs *childregs; 	childregs = task_pt_regs(p); 	*childregs = *regs;	childregs->a4 = 0; 	if (usp == -1)		/* case of  __kernel_thread: we return to supervisor space */		childregs->sp = (unsigned long)(childregs + 1);	else		/* Otherwise use the given stack */		childregs->sp = usp; 	/* Set usp/ksp */	p->thread.usp = childregs->sp;	/* switch_to uses stack to save/restore 14 callee-saved regs */	thread_saved_ksp(p) = (unsigned long)childregs - 8;	p->thread.pc = (unsigned int) ret_from_fork;	p->thread.wchan	= (unsigned long) ret_from_fork;#ifdef __DSBT__	{		unsigned long dp; 		asm volatile ("mv .S2 b14,%0\n" : "=b"(dp)); 		thread_saved_dp(p) = dp;		if (usp == -1)			childregs->dp = dp;	}#endif	return 0;} /* * c6x_execve() executes a new program. */SYSCALL_DEFINE4(c6x_execve, const char __user *, name,		const char __user *const __user *, argv,		const char __user *const __user *, envp,		struct pt_regs *, regs){	int error;	char *filename; 	filename = getname(name);	error = PTR_ERR(filename);	if (IS_ERR(filename))		goto out; 	error = do_execve(filename, argv, envp, regs);	putname(filename);out:	return error;} unsigned long get_wchan(struct task_struct *p){	return p->thread.wchan;}