xref: /openbmc/linux/arch/x86/include/asm/mem_encrypt.h (revision 867e6d38)
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 
24 void sme_encrypt_execute(unsigned long encrypted_kernel_vaddr,
25 			 unsigned long decrypted_kernel_vaddr,
26 			 unsigned long kernel_len,
27 			 unsigned long encryption_wa,
28 			 unsigned long encryption_pgd);
29 
30 void __init sme_early_encrypt(resource_size_t paddr,
31 			      unsigned long size);
32 void __init sme_early_decrypt(resource_size_t paddr,
33 			      unsigned long size);
34 
35 void __init sme_map_bootdata(char *real_mode_data);
36 void __init sme_unmap_bootdata(char *real_mode_data);
37 
38 void __init sme_early_init(void);
39 void __init sev_setup_arch(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 static inline void __init sev_setup_arch(void) { }
73 
74 static inline void __init sme_encrypt_kernel(struct boot_params *bp) { }
75 static inline void __init sme_enable(struct boot_params *bp) { }
76 
77 static inline void sev_es_init_vc_handling(void) { }
78 static inline bool sme_active(void) { return false; }
79 static inline bool sev_active(void) { return false; }
80 static inline bool sev_es_active(void) { return false; }
81 
82 static inline int __init
83 early_set_memory_decrypted(unsigned long vaddr, unsigned long size) { return 0; }
84 static inline int __init
85 early_set_memory_encrypted(unsigned long vaddr, unsigned long size) { return 0; }
86 
87 static inline void mem_encrypt_free_decrypted_mem(void) { }
88 
89 #define __bss_decrypted
90 
91 #endif	/* CONFIG_AMD_MEM_ENCRYPT */
92 
93 /*
94  * The __sme_pa() and __sme_pa_nodebug() macros are meant for use when
95  * writing to or comparing values from the cr3 register.  Having the
96  * encryption mask set in cr3 enables the PGD entry to be encrypted and
97  * avoid special case handling of PGD allocations.
98  */
99 #define __sme_pa(x)		(__pa(x) | sme_me_mask)
100 #define __sme_pa_nodebug(x)	(__pa_nodebug(x) | sme_me_mask)
101 
102 extern char __start_bss_decrypted[], __end_bss_decrypted[], __start_bss_decrypted_unused[];
103 
104 static inline bool mem_encrypt_active(void)
105 {
106 	return sme_me_mask;
107 }
108 
109 static 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