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()        mfsp(SR_USER)
  17 #define get_kernel_space()      SR_KERNEL
  18
  19 /* Returns 0 for success, otherwise, returns number of bytes not transferred. */
  20 extern unsigned long pa_memcpy(void *dst, const void *src,
  21                                 unsigned long len);
  22
  23 unsigned long raw_copy_to_user(void __user *dst, const void *src,
  24                                unsigned long len)
  25 {
  26         mtsp(get_kernel_space(), SR_TEMP1);
  27         mtsp(get_user_space(), SR_TEMP2);
  28         return pa_memcpy((void __force *)dst, src, len);
  29 }
  30 EXPORT_SYMBOL(raw_copy_to_user);
  31
  32 unsigned long raw_copy_from_user(void *dst, const void __user *src,
  33                                unsigned long len)
  34 {
  35         mtsp(get_user_space(), SR_TEMP1);
  36         mtsp(get_kernel_space(), SR_TEMP2);
  37         return pa_memcpy(dst, (void __force *)src, len);
  38 }
  39 EXPORT_SYMBOL(raw_copy_from_user);
  40
  41 void * memcpy(void * dst,const void *src, size_t count)
  42 {
  43         mtsp(get_kernel_space(), SR_TEMP1);
  44         mtsp(get_kernel_space(), SR_TEMP2);
  45         pa_memcpy(dst, src, count);
  46         return dst;
  47 }
  48
  49 EXPORT_SYMBOL(memcpy);
  50
  51 bool 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 }