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 #include <linux/mm.h>
16
17 #define get_user_space() mfsp(SR_USER)
18 #define get_kernel_space() SR_KERNEL
19
20 /* Returns 0 for success, otherwise, returns number of bytes not transferred. */
21 extern unsigned long pa_memcpy(void *dst, const void *src,
22 unsigned long len);
23
raw_copy_to_user(void __user * dst,const void * src,unsigned long len)24 unsigned long raw_copy_to_user(void __user *dst, const void *src,
25 unsigned long len)
26 {
27 mtsp(get_kernel_space(), SR_TEMP1);
28 mtsp(get_user_space(), SR_TEMP2);
29 return pa_memcpy((void __force *)dst, src, len);
30 }
31 EXPORT_SYMBOL(raw_copy_to_user);
32
raw_copy_from_user(void * dst,const void __user * src,unsigned long len)33 unsigned long raw_copy_from_user(void *dst, const void __user *src,
34 unsigned long len)
35 {
36 unsigned long start = (unsigned long) src;
37 unsigned long end = start + len;
38 unsigned long newlen = len;
39
40 mtsp(get_user_space(), SR_TEMP1);
41 mtsp(get_kernel_space(), SR_TEMP2);
42
43 /* Check region is user accessible */
44 if (start)
45 while (start < end) {
46 if (!prober_user(SR_TEMP1, start)) {
47 newlen = (start - (unsigned long) src);
48 break;
49 }
50 start += PAGE_SIZE;
51 /* align to page boundry which may have different permission */
52 start = PAGE_ALIGN_DOWN(start);
53 }
54 return len - newlen + pa_memcpy(dst, (void __force *)src, newlen);
55 }
56 EXPORT_SYMBOL(raw_copy_from_user);
57
memcpy(void * dst,const void * src,size_t count)58 void * memcpy(void * dst,const void *src, size_t count)
59 {
60 mtsp(get_kernel_space(), SR_TEMP1);
61 mtsp(get_kernel_space(), SR_TEMP2);
62 pa_memcpy(dst, src, count);
63 return dst;
64 }
65
66 EXPORT_SYMBOL(memcpy);
67
copy_from_kernel_nofault_allowed(const void * unsafe_src,size_t size)68 bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
69 {
70 if ((unsigned long)unsafe_src < PAGE_SIZE)
71 return false;
72 /* check for I/O space F_EXTEND(0xfff00000) access as well? */
73 return true;
74 }
75