1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * AMD Memory Encryption Support
4 *
5 * Copyright (C) 2016 Advanced Micro Devices, Inc.
6 *
7 * Author: Tom Lendacky <thomas.lendacky@amd.com>
8 */
9
10#ifndef __X86_MEM_ENCRYPT_H__
11#define __X86_MEM_ENCRYPT_H__
12
13#ifndef __ASSEMBLY__
14
15#include <linux/init.h>
16#include <linux/cc_platform.h>
17
18#include <asm/bootparam.h>
19
20#ifdef CONFIG_X86_MEM_ENCRYPT
21void __init mem_encrypt_init(void);
22void __init mem_encrypt_setup_arch(void);
23#else
24static inline void mem_encrypt_init(void) { }
25static inline void __init mem_encrypt_setup_arch(void) { }
26#endif
27
28#ifdef CONFIG_AMD_MEM_ENCRYPT
29
30extern u64 sme_me_mask;
31extern u64 sev_status;
32
33void sme_encrypt_execute(unsigned long encrypted_kernel_vaddr,
34 unsigned long decrypted_kernel_vaddr,
35 unsigned long kernel_len,
36 unsigned long encryption_wa,
37 unsigned long encryption_pgd);
38
39void __init sme_early_encrypt(resource_size_t paddr,
40 unsigned long size);
41void __init sme_early_decrypt(resource_size_t paddr,
42 unsigned long size);
43
44void __init sme_map_bootdata(char *real_mode_data);
45void __init sme_unmap_bootdata(char *real_mode_data);
46
47void __init sme_early_init(void);
48
49void __init sme_encrypt_kernel(struct boot_params *bp);
50void __init sme_enable(struct boot_params *bp);
51
52int __init early_set_memory_decrypted(unsigned long vaddr, unsigned long size);
53int __init early_set_memory_encrypted(unsigned long vaddr, unsigned long size);
54void __init early_set_mem_enc_dec_hypercall(unsigned long vaddr,
55 unsigned long size, bool enc);
56
57void __init mem_encrypt_free_decrypted_mem(void);
58
59void __init sev_es_init_vc_handling(void);
60
61#define __bss_decrypted __section(".bss..decrypted")
62
63#else /* !CONFIG_AMD_MEM_ENCRYPT */
64
65#define sme_me_mask 0ULL
66#define sev_status 0ULL
67
68static inline void __init sme_early_encrypt(resource_size_t paddr,
69 unsigned long size) { }
70static inline void __init sme_early_decrypt(resource_size_t paddr,
71 unsigned long size) { }
72
73static inline void __init sme_map_bootdata(char *real_mode_data) { }
74static inline void __init sme_unmap_bootdata(char *real_mode_data) { }
75
76static inline void __init sme_early_init(void) { }
77
78static inline void __init sme_encrypt_kernel(struct boot_params *bp) { }
79static inline void __init sme_enable(struct boot_params *bp) { }
80
81static inline void sev_es_init_vc_handling(void) { }
82
83static inline int __init
84early_set_memory_decrypted(unsigned long vaddr, unsigned long size) { return 0; }
85static inline int __init
86early_set_memory_encrypted(unsigned long vaddr, unsigned long size) { return 0; }
87static inline void __init
88early_set_mem_enc_dec_hypercall(unsigned long vaddr, unsigned long size, bool enc) {}
89
90static inline void mem_encrypt_free_decrypted_mem(void) { }
91
92#define __bss_decrypted
93
94#endif /* CONFIG_AMD_MEM_ENCRYPT */
95
96void add_encrypt_protection_map(void);
97
98/*
99 * The __sme_pa() and __sme_pa_nodebug() macros are meant for use when
100 * writing to or comparing values from the cr3 register. Having the
101 * encryption mask set in cr3 enables the PGD entry to be encrypted and
102 * avoid special case handling of PGD allocations.
103 */
104#define __sme_pa(x) (__pa(x) | sme_me_mask)
105#define __sme_pa_nodebug(x) (__pa_nodebug(x) | sme_me_mask)
106
107extern char __start_bss_decrypted[], __end_bss_decrypted[], __start_bss_decrypted_unused[];
108
109static inline u64 sme_get_me_mask(void)
110{
111 return sme_me_mask;
112}
113
114#endif /* __ASSEMBLY__ */
115
116#endif /* __X86_MEM_ENCRYPT_H__ */
117

source code of linux/arch/x86/include/asm/mem_encrypt.h