LXR linux/arch/parisc/lib/memcpy.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *    Optimized memory copy routines.
   4 *
   5 *    Copyright (C) 2004 Randolph Chung <tausq@debian.org>
   6 *    Copyright (C) 2013-2017 Helge Deller <deller@gmx.de>
   7 *
   8 *    Portions derived from the GNU C Library
   9 *    Copyright (C) 1991, 1997, 2003 Free Software Foundation, Inc.
  10 */
  11
  12#include <linux/module.h>
  13#include <linux/compiler.h>
  14#include <linux/uaccess.h>
  15
  16#define get_user_space() (uaccess_kernel() ? 0 : mfsp(3))
  17#define get_kernel_space() (0)
  18
  19/* Returns 0 for success, otherwise, returns number of bytes not transferred. */
  20extern unsigned long pa_memcpy(void *dst, const void *src,
  21                                unsigned long len);
  22
  23unsigned long raw_copy_to_user(void __user *dst, const void *src,
  24                               unsigned long len)
  25{
  26        mtsp(get_kernel_space(), 1);
  27        mtsp(get_user_space(), 2);
  28        return pa_memcpy((void __force *)dst, src, len);
  29}
  30EXPORT_SYMBOL(raw_copy_to_user);
  31
  32unsigned long raw_copy_from_user(void *dst, const void __user *src,
  33                               unsigned long len)
  34{
  35        mtsp(get_user_space(), 1);
  36        mtsp(get_kernel_space(), 2);
  37        return pa_memcpy(dst, (void __force *)src, len);
  38}
  39EXPORT_SYMBOL(raw_copy_from_user);
  40
  41void * memcpy(void * dst,const void *src, size_t count)
  42{
  43        mtsp(get_kernel_space(), 1);
  44        mtsp(get_kernel_space(), 2);
  45        pa_memcpy(dst, src, count);
  46        return dst;
  47}
  48
  49EXPORT_SYMBOL(memcpy);
  50
  51bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
  52{
  53        if ((unsigned long)unsafe_src < PAGE_SIZE)
  54                return false;
  55        /* check for I/O space F_EXTEND(0xfff00000) access as well? */
  56        return true;
  57}
  58