xref: /openbmc/linux/arch/parisc/lib/memcpy.c (revision f71a261a)
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 }
58