xref: /openbmc/linux/arch/x86/include/asm/mem_encrypt.h (revision 842ed298)
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 
17 #include <asm/bootparam.h>
18 
19 #ifdef CONFIG_AMD_MEM_ENCRYPT
20 
21 extern u64 sme_me_mask;
22 extern u64 sev_status;
23 extern bool sev_enabled;
24 
25 void sme_encrypt_execute(unsigned long encrypted_kernel_vaddr,
26 			 unsigned long decrypted_kernel_vaddr,
27 			 unsigned long kernel_len,
28 			 unsigned long encryption_wa,
29 			 unsigned long encryption_pgd);
30 
31 void __init sme_early_encrypt(resource_size_t paddr,
32 			      unsigned long size);
33 void __init sme_early_decrypt(resource_size_t paddr,
34 			      unsigned long size);
35 
36 void __init sme_map_bootdata(char *real_mode_data);
37 void __init sme_unmap_bootdata(char *real_mode_data);
38 
39 void __init sme_early_init(void);
40 void __init sev_setup_arch(void);
41 
42 void __init sme_encrypt_kernel(struct boot_params *bp);
43 void __init sme_enable(struct boot_params *bp);
44 
45 int __init early_set_memory_decrypted(unsigned long vaddr, unsigned long size);
46 int __init early_set_memory_encrypted(unsigned long vaddr, unsigned long size);
47 
48 void __init mem_encrypt_free_decrypted_mem(void);
49 
50 /* Architecture __weak replacement functions */
51 void __init mem_encrypt_init(void);
52 
53 void __init sev_es_init_vc_handling(void);
54 bool sme_active(void);
55 bool sev_active(void);
56 bool sev_es_active(void);
57 
58 #define __bss_decrypted __section(".bss..decrypted")
59 
60 #else	/* !CONFIG_AMD_MEM_ENCRYPT */
61 
62 #define sme_me_mask	0ULL
63 
64 static inline void __init sme_early_encrypt(resource_size_t paddr,
65 					    unsigned long size) { }
66 static inline void __init sme_early_decrypt(resource_size_t paddr,
67 					    unsigned long size) { }
68 
69 static inline void __init sme_map_bootdata(char *real_mode_data) { }
70 static inline void __init sme_unmap_bootdata(char *real_mode_data) { }
71 
72 static inline void __init sme_early_init(void) { }
73 static inline void __init sev_setup_arch(void) { }
74 
75 static inline void __init sme_encrypt_kernel(struct boot_params *bp) { }
76 static inline void __init sme_enable(struct boot_params *bp) { }
77 
78 static inline void sev_es_init_vc_handling(void) { }
79 static inline bool sme_active(void) { return false; }
80 static inline bool sev_active(void) { return false; }
81 static inline bool sev_es_active(void) { return false; }
82 
83 static inline int __init
84 early_set_memory_decrypted(unsigned long vaddr, unsigned long size) { return 0; }
85 static inline int __init
86 early_set_memory_encrypted(unsigned long vaddr, unsigned long size) { return 0; }
87 
88 static inline void mem_encrypt_free_decrypted_mem(void) { }
89 
90 #define __bss_decrypted
91 
92 #endif	/* CONFIG_AMD_MEM_ENCRYPT */
93 
94 /*
95  * The __sme_pa() and __sme_pa_nodebug() macros are meant for use when
96  * writing to or comparing values from the cr3 register.  Having the
97  * encryption mask set in cr3 enables the PGD entry to be encrypted and
98  * avoid special case handling of PGD allocations.
99  */
100 #define __sme_pa(x)		(__pa(x) | sme_me_mask)
101 #define __sme_pa_nodebug(x)	(__pa_nodebug(x) | sme_me_mask)
102 
103 extern char __start_bss_decrypted[], __end_bss_decrypted[], __start_bss_decrypted_unused[];
104 
105 static inline bool mem_encrypt_active(void)
106 {
107 	return sme_me_mask;
108 }
109 
110 static inline u64 sme_get_me_mask(void)
111 {
112 	return sme_me_mask;
113 }
114 
115 #endif	/* __ASSEMBLY__ */
116 
117 #endif	/* __X86_MEM_ENCRYPT_H__ */
118