arch/c6x/include/asm/uaccess.h

/*
 *  Copyright (C) 2011 Texas Instruments Incorporated
 *  Author: Mark Salter <msalter@redhat.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.
 */
#ifndef _ASM_C6X_UACCESS_H
#define _ASM_C6X_UACCESS_H

#include <linux/types.h>
#include <linux/compiler.h>
#include <linux/string.h>

#ifdef CONFIG_ACCESS_CHECK
#define __access_ok _access_ok
#endif

/*
 * __copy_from_user/copy_to_user are based on ones in asm-generic/uaccess.h
 *
 * C6X supports unaligned 32 and 64 bit loads and stores.
 */
static inline __must_check long __copy_from_user(void *to,
		const void __user *from, unsigned long n)
{
	u32 tmp32;
	u64 tmp64;

	if (__builtin_constant_p(n)) {
		switch (n) {
		case 1:
			*(u8 *)to = *(u8 __force *)from;
			return 0;
		case 4:
			asm volatile ("ldnw .d1t1 *%2,%0\n"
				      "nop  4\n"
				      "stnw .d1t1 %0,*%1\n"
				      : "=&a"(tmp32)
				      : "A"(to), "a"(from)
				      : "memory");
			return 0;
		case 8:
			asm volatile ("ldndw .d1t1 *%2,%0\n"
				      "nop   4\n"
				      "stndw .d1t1 %0,*%1\n"
				      : "=&a"(tmp64)
				      : "a"(to), "a"(from)
				      : "memory");
			return 0;
		default:
			break;
		}
	}

	memcpy(to, (const void __force *)from, n);
	return 0;
}

static inline __must_check long __copy_to_user(void __user *to,
		const void *from, unsigned long n)
{
	u32 tmp32;
	u64 tmp64;

	if (__builtin_constant_p(n)) {
		switch (n) {
		case 1:
			*(u8 __force *)to = *(u8 *)from;
			return 0;
		case 4:
			asm volatile ("ldnw .d1t1 *%2,%0\n"
				      "nop  4\n"
				      "stnw .d1t1 %0,*%1\n"
				      : "=&a"(tmp32)
				      : "a"(to), "a"(from)
				      : "memory");
			return 0;
		case 8:
			asm volatile ("ldndw .d1t1 *%2,%0\n"
				      "nop   4\n"
				      "stndw .d1t1 %0,*%1\n"
				      : "=&a"(tmp64)
				      : "a"(to), "a"(from)
				      : "memory");
			return 0;
		default:
			break;
		}
	}

	memcpy((void __force *)to, from, n);
	return 0;
}

#define __copy_to_user   __copy_to_user
#define __copy_from_user __copy_from_user

extern int _access_ok(unsigned long addr, unsigned long size);
#ifdef CONFIG_ACCESS_CHECK
#define __access_ok _access_ok
#endif

#include <asm-generic/uaccess.h>

#endif /* _ASM_C6X_UACCESS_H */