uaccess.h

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/*
 *  Copyright (C) 2011 Texas Instruments Incorporated
 *  Author: Mark Salter <[email protected]>
 *
 *  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 */