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 __ASSEMBLER__
14
15#include <linux/init.h>
16#include <linux/cc_platform.h>
17
18#include <asm/asm.h>
19struct boot_params;
20
21#ifdef CONFIG_X86_MEM_ENCRYPT
22void __init mem_encrypt_init(void);
23void __init mem_encrypt_setup_arch(void);
24#else
25static inline void mem_encrypt_init(void) { }
26static inline void __init mem_encrypt_setup_arch(void) { }
27#endif
28
29#ifdef CONFIG_AMD_MEM_ENCRYPT
30
31extern u64 sme_me_mask;
32extern u64 sev_status;
33
34void sme_encrypt_execute(unsigned long encrypted_kernel_vaddr,
35 unsigned long decrypted_kernel_vaddr,
36 unsigned long kernel_len,
37 unsigned long encryption_wa,
38 unsigned long encryption_pgd);
39
40void __init sme_early_encrypt(resource_size_t paddr,
41 unsigned long size);
42void __init sme_early_decrypt(resource_size_t paddr,
43 unsigned long size);
44
45void __init sme_map_bootdata(char *real_mode_data);
46void __init sme_unmap_bootdata(char *real_mode_data);
47
48void __init sme_early_init(void);
49
50void sme_encrypt_kernel(struct boot_params *bp);
51void sme_enable(struct boot_params *bp);
52
53int __init early_set_memory_decrypted(unsigned long vaddr, unsigned long size);
54int __init early_set_memory_encrypted(unsigned long vaddr, unsigned long size);
55void __init early_set_mem_enc_dec_hypercall(unsigned long vaddr,
56 unsigned long size, bool enc);
57
58void __init mem_encrypt_free_decrypted_mem(void);
59
60void __init sev_es_init_vc_handling(void);
61
62static inline u64 sme_get_me_mask(void)
63{
64 return sme_me_mask;
65}
66
67#define __bss_decrypted __section(".bss..decrypted")
68
69#else /* !CONFIG_AMD_MEM_ENCRYPT */
70
71#define sme_me_mask 0ULL
72#define sev_status 0ULL
73
74static inline void __init sme_early_encrypt(resource_size_t paddr,
75 unsigned long size) { }
76static inline void __init sme_early_decrypt(resource_size_t paddr,
77 unsigned long size) { }
78
79static inline void __init sme_map_bootdata(char *real_mode_data) { }
80static inline void __init sme_unmap_bootdata(char *real_mode_data) { }
81
82static inline void __init sme_early_init(void) { }
83
84static inline void sme_encrypt_kernel(struct boot_params *bp) { }
85static inline void sme_enable(struct boot_params *bp) { }
86
87static inline void sev_es_init_vc_handling(void) { }
88
89static inline int __init
90early_set_memory_decrypted(unsigned long vaddr, unsigned long size) { return 0; }
91static inline int __init
92early_set_memory_encrypted(unsigned long vaddr, unsigned long size) { return 0; }
93static inline void __init
94early_set_mem_enc_dec_hypercall(unsigned long vaddr, unsigned long size, bool enc) {}
95
96static inline void mem_encrypt_free_decrypted_mem(void) { }
97
98static inline u64 sme_get_me_mask(void) { return 0; }
99
100#define __bss_decrypted
101
102#endif /* CONFIG_AMD_MEM_ENCRYPT */
103
104void add_encrypt_protection_map(void);
105
106/*
107 * The __sme_pa() and __sme_pa_nodebug() macros are meant for use when
108 * writing to or comparing values from the cr3 register. Having the
109 * encryption mask set in cr3 enables the PGD entry to be encrypted and
110 * avoid special case handling of PGD allocations.
111 */
112#define __sme_pa(x) (__pa(x) | sme_me_mask)
113#define __sme_pa_nodebug(x) (__pa_nodebug(x) | sme_me_mask)
114
115extern char __start_bss_decrypted[], __end_bss_decrypted[], __start_bss_decrypted_unused[];
116
117#endif /* __ASSEMBLER__ */
118
119#endif /* __X86_MEM_ENCRYPT_H__ */
120

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