xref: /openbmc/linux/arch/x86/include/asm/uaccess_32.h (revision e3b9f1e8)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_UACCESS_32_H
3 #define _ASM_X86_UACCESS_32_H
4 
5 /*
6  * User space memory access functions
7  */
8 #include <linux/string.h>
9 #include <asm/asm.h>
10 #include <asm/page.h>
11 
12 unsigned long __must_check __copy_user_ll
13 		(void *to, const void *from, unsigned long n);
14 unsigned long __must_check __copy_from_user_ll_nocache_nozero
15 		(void *to, const void __user *from, unsigned long n);
16 
17 static __always_inline unsigned long __must_check
18 raw_copy_to_user(void __user *to, const void *from, unsigned long n)
19 {
20 	return __copy_user_ll((__force void *)to, from, n);
21 }
22 
23 static __always_inline unsigned long
24 raw_copy_from_user(void *to, const void __user *from, unsigned long n)
25 {
26 	if (__builtin_constant_p(n)) {
27 		unsigned long ret;
28 
29 		switch (n) {
30 		case 1:
31 			ret = 0;
32 			__uaccess_begin_nospec();
33 			__get_user_asm_nozero(*(u8 *)to, from, ret,
34 					      "b", "b", "=q", 1);
35 			__uaccess_end();
36 			return ret;
37 		case 2:
38 			ret = 0;
39 			__uaccess_begin_nospec();
40 			__get_user_asm_nozero(*(u16 *)to, from, ret,
41 					      "w", "w", "=r", 2);
42 			__uaccess_end();
43 			return ret;
44 		case 4:
45 			ret = 0;
46 			__uaccess_begin_nospec();
47 			__get_user_asm_nozero(*(u32 *)to, from, ret,
48 					      "l", "k", "=r", 4);
49 			__uaccess_end();
50 			return ret;
51 		}
52 	}
53 	return __copy_user_ll(to, (__force const void *)from, n);
54 }
55 
56 static __always_inline unsigned long
57 __copy_from_user_inatomic_nocache(void *to, const void __user *from,
58 				  unsigned long n)
59 {
60        return __copy_from_user_ll_nocache_nozero(to, from, n);
61 }
62 
63 #endif /* _ASM_X86_UACCESS_32_H */
64