xref: /openbmc/linux/arch/x86/include/asm/mem_encrypt.h (revision 13dd8710)
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 
41 void __init sme_encrypt_kernel(struct boot_params *bp);
42 void __init sme_enable(struct boot_params *bp);
43 
44 int __init early_set_memory_decrypted(unsigned long vaddr, unsigned long size);
45 int __init early_set_memory_encrypted(unsigned long vaddr, unsigned long size);
46 
47 void __init mem_encrypt_free_decrypted_mem(void);
48 
49 /* Architecture __weak replacement functions */
50 void __init mem_encrypt_init(void);
51 
52 void __init sev_es_init_vc_handling(void);
53 bool sme_active(void);
54 bool sev_active(void);
55 bool sev_es_active(void);
56 
57 #define __bss_decrypted __section(".bss..decrypted")
58 
59 #else	/* !CONFIG_AMD_MEM_ENCRYPT */
60 
61 #define sme_me_mask	0ULL
62 
63 static inline void __init sme_early_encrypt(resource_size_t paddr,
64 					    unsigned long size) { }
65 static inline void __init sme_early_decrypt(resource_size_t paddr,
66 					    unsigned long size) { }
67 
68 static inline void __init sme_map_bootdata(char *real_mode_data) { }
69 static inline void __init sme_unmap_bootdata(char *real_mode_data) { }
70 
71 static inline void __init sme_early_init(void) { }
72 
73 static inline void __init sme_encrypt_kernel(struct boot_params *bp) { }
74 static inline void __init sme_enable(struct boot_params *bp) { }
75 
76 static inline void sev_es_init_vc_handling(void) { }
77 static inline bool sme_active(void) { return false; }
78 static inline bool sev_active(void) { return false; }
79 static inline bool sev_es_active(void) { return false; }
80 
81 static inline int __init
82 early_set_memory_decrypted(unsigned long vaddr, unsigned long size) { return 0; }
83 static inline int __init
84 early_set_memory_encrypted(unsigned long vaddr, unsigned long size) { return 0; }
85 
86 static inline void mem_encrypt_free_decrypted_mem(void) { }
87 
88 #define __bss_decrypted
89 
90 #endif	/* CONFIG_AMD_MEM_ENCRYPT */
91 
92 /*
93  * The __sme_pa() and __sme_pa_nodebug() macros are meant for use when
94  * writing to or comparing values from the cr3 register.  Having the
95  * encryption mask set in cr3 enables the PGD entry to be encrypted and
96  * avoid special case handling of PGD allocations.
97  */
98 #define __sme_pa(x)		(__pa(x) | sme_me_mask)
99 #define __sme_pa_nodebug(x)	(__pa_nodebug(x) | sme_me_mask)
100 
101 extern char __start_bss_decrypted[], __end_bss_decrypted[], __start_bss_decrypted_unused[];
102 
103 static inline bool mem_encrypt_active(void)
104 {
105 	return sme_me_mask;
106 }
107 
108 static inline u64 sme_get_me_mask(void)
109 {
110 	return sme_me_mask;
111 }
112 
113 #endif	/* __ASSEMBLY__ */
114 
115 #endif	/* __X86_MEM_ENCRYPT_H__ */
116