xref: /openbmc/linux/arch/x86/include/asm/mem_encrypt.h (revision 44ce0cd3)
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 bool sev_enabled;
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 
40 void __init sme_encrypt_kernel(struct boot_params *bp);
41 void __init sme_enable(struct boot_params *bp);
42 
43 int __init early_set_memory_decrypted(unsigned long vaddr, unsigned long size);
44 int __init early_set_memory_encrypted(unsigned long vaddr, unsigned long size);
45 
46 /* Architecture __weak replacement functions */
47 void __init mem_encrypt_init(void);
48 void __init mem_encrypt_free_decrypted_mem(void);
49 
50 bool sme_active(void);
51 bool sev_active(void);
52 
53 #define __bss_decrypted __attribute__((__section__(".bss..decrypted")))
54 
55 #else	/* !CONFIG_AMD_MEM_ENCRYPT */
56 
57 #define sme_me_mask	0ULL
58 
59 static inline void __init sme_early_encrypt(resource_size_t paddr,
60 					    unsigned long size) { }
61 static inline void __init sme_early_decrypt(resource_size_t paddr,
62 					    unsigned long size) { }
63 
64 static inline void __init sme_map_bootdata(char *real_mode_data) { }
65 static inline void __init sme_unmap_bootdata(char *real_mode_data) { }
66 
67 static inline void __init sme_early_init(void) { }
68 
69 static inline void __init sme_encrypt_kernel(struct boot_params *bp) { }
70 static inline void __init sme_enable(struct boot_params *bp) { }
71 
72 static inline bool sme_active(void) { return false; }
73 static inline bool sev_active(void) { return false; }
74 
75 static inline int __init
76 early_set_memory_decrypted(unsigned long vaddr, unsigned long size) { return 0; }
77 static inline int __init
78 early_set_memory_encrypted(unsigned long vaddr, unsigned long size) { return 0; }
79 
80 #define __bss_decrypted
81 
82 #endif	/* CONFIG_AMD_MEM_ENCRYPT */
83 
84 /*
85  * The __sme_pa() and __sme_pa_nodebug() macros are meant for use when
86  * writing to or comparing values from the cr3 register.  Having the
87  * encryption mask set in cr3 enables the PGD entry to be encrypted and
88  * avoid special case handling of PGD allocations.
89  */
90 #define __sme_pa(x)		(__pa(x) | sme_me_mask)
91 #define __sme_pa_nodebug(x)	(__pa_nodebug(x) | sme_me_mask)
92 
93 extern char __start_bss_decrypted[], __end_bss_decrypted[], __start_bss_decrypted_unused[];
94 
95 #endif	/* __ASSEMBLY__ */
96 
97 #endif	/* __X86_MEM_ENCRYPT_H__ */
98