1/*
  2 *  Copyright (C) 2011 Texas Instruments Incorporated
  3 *  Author: Mark Salter <msalter@redhat.com>
  4 *
  5 *  This program is free software; you can redistribute it and/or modify
  6 *  it under the terms of the GNU General Public License version 2 as
  7 *  published by the Free Software Foundation.
  8 */
  9#ifndef _ASM_C6X_UACCESS_H
 10#define _ASM_C6X_UACCESS_H
 11
 12#include <linux/types.h>
 13#include <linux/compiler.h>
 14#include <linux/string.h>
 15
 16#ifdef CONFIG_ACCESS_CHECK
 17#define __access_ok _access_ok
 18#endif
 19
 20/*
 21 * __copy_from_user/copy_to_user are based on ones in asm-generic/uaccess.h
 22 *
 23 * C6X supports unaligned 32 and 64 bit loads and stores.
 24 */
 25static inline __must_check long __copy_from_user(void *to,
 26		const void __user *from, unsigned long n)
 27{
 28	u32 tmp32;
 29	u64 tmp64;
 30
 31	if (__builtin_constant_p(n)) {
 32		switch (n) {
 33		case 1:
 34			*(u8 *)to = *(u8 __force *)from;
 35			return 0;
 36		case 4:
 37			asm volatile ("ldnw .d1t1 *%2,%0\n"
 38				      "nop  4\n"
 39				      "stnw .d1t1 %0,*%1\n"
 40				      : "=&a"(tmp32)
 41				      : "A"(to), "a"(from)
 42				      : "memory");
 43			return 0;
 44		case 8:
 45			asm volatile ("ldndw .d1t1 *%2,%0\n"
 46				      "nop   4\n"
 47				      "stndw .d1t1 %0,*%1\n"
 48				      : "=&a"(tmp64)
 49				      : "a"(to), "a"(from)
 50				      : "memory");
 51			return 0;
 52		default:
 53			break;
 54		}
 55	}
 56
 57	memcpy(to, (const void __force *)from, n);
 58	return 0;
 59}
 60
 61static inline __must_check long __copy_to_user(void __user *to,
 62		const void *from, unsigned long n)
 63{
 64	u32 tmp32;
 65	u64 tmp64;
 66
 67	if (__builtin_constant_p(n)) {
 68		switch (n) {
 69		case 1:
 70			*(u8 __force *)to = *(u8 *)from;
 71			return 0;
 72		case 4:
 73			asm volatile ("ldnw .d1t1 *%2,%0\n"
 74				      "nop  4\n"
 75				      "stnw .d1t1 %0,*%1\n"
 76				      : "=&a"(tmp32)
 77				      : "a"(to), "a"(from)
 78				      : "memory");
 79			return 0;
 80		case 8:
 81			asm volatile ("ldndw .d1t1 *%2,%0\n"
 82				      "nop   4\n"
 83				      "stndw .d1t1 %0,*%1\n"
 84				      : "=&a"(tmp64)
 85				      : "a"(to), "a"(from)
 86				      : "memory");
 87			return 0;
 88		default:
 89			break;
 90		}
 91	}
 92
 93	memcpy((void __force *)to, from, n);
 94	return 0;
 95}
 96
 97#define __copy_to_user   __copy_to_user
 98#define __copy_from_user __copy_from_user
 99
100extern int _access_ok(unsigned long addr, unsigned long size);
101#ifdef CONFIG_ACCESS_CHECK
102#define __access_ok _access_ok
103#endif
104
105#include <asm-generic/uaccess.h>
106
107#endif /* _ASM_C6X_UACCESS_H */