1 /*
2  * AMD Memory Encryption Support
3  *
4  * Copyright (C) 2016 Advanced Micro Devices, Inc.
5  *
6  * Author: Tom Lendacky <thomas.lendacky@amd.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  */
12 
13 #ifndef __MEM_ENCRYPT_H__
14 #define __MEM_ENCRYPT_H__
15 
16 #ifndef __ASSEMBLY__
17 
18 #ifdef CONFIG_ARCH_HAS_MEM_ENCRYPT
19 
20 #include <asm/mem_encrypt.h>
21 
22 #else	/* !CONFIG_ARCH_HAS_MEM_ENCRYPT */
23 
24 #define sme_me_mask	0ULL
25 
sme_active(void)26 static inline bool sme_active(void) { return false; }
sev_active(void)27 static inline bool sev_active(void) { return false; }
28 
29 #endif	/* CONFIG_ARCH_HAS_MEM_ENCRYPT */
30 
mem_encrypt_active(void)31 static inline bool mem_encrypt_active(void)
32 {
33 	return sme_me_mask;
34 }
35 
sme_get_me_mask(void)36 static inline u64 sme_get_me_mask(void)
37 {
38 	return sme_me_mask;
39 }
40 
41 #ifdef CONFIG_AMD_MEM_ENCRYPT
42 /*
43  * The __sme_set() and __sme_clr() macros are useful for adding or removing
44  * the encryption mask from a value (e.g. when dealing with pagetable
45  * entries).
46  */
47 #define __sme_set(x)		((x) | sme_me_mask)
48 #define __sme_clr(x)		((x) & ~sme_me_mask)
49 #else
50 #define __sme_set(x)		(x)
51 #define __sme_clr(x)		(x)
52 #endif
53 
54 #endif	/* __ASSEMBLY__ */
55 
56 #endif	/* __MEM_ENCRYPT_H__ */
57