arch/x86/include/asm/mem_encrypt.h

   1 /*
   2  * AMD Memory Encryption Support
   3  *
   4  * Copyright (C) 2016 Advanced Micro Devices, Inc.
   5  *
   6  * Author: Tom Lendacky <thomas.lendacky@amd.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #ifndef __X86_MEM_ENCRYPT_H__
  14 #define __X86_MEM_ENCRYPT_H__
  15
  16 #ifndef __ASSEMBLY__
  17
  18 #include <linux/init.h>
  19
  20 #ifdef CONFIG_AMD_MEM_ENCRYPT
  21
  22 extern unsigned long sme_me_mask;
  23
  24 void __init sme_early_init(void);
  25
  26 void __init sme_encrypt_kernel(void);
  27 void __init sme_enable(void);
  28
  29 #else   /* !CONFIG_AMD_MEM_ENCRYPT */
  30
  31 #define sme_me_mask     0UL
  32
  33 static inline void __init sme_early_init(void) { }
  34
  35 static inline void __init sme_encrypt_kernel(void) { }
  36 static inline void __init sme_enable(void) { }
  37
  38 #endif  /* CONFIG_AMD_MEM_ENCRYPT */
  39
  40 /*
  41  * The __sme_pa() and __sme_pa_nodebug() macros are meant for use when
  42  * writing to or comparing values from the cr3 register.  Having the
  43  * encryption mask set in cr3 enables the PGD entry to be encrypted and
  44  * avoid special case handling of PGD allocations.
  45  */
  46 #define __sme_pa(x)             (__pa(x) | sme_me_mask)
  47 #define __sme_pa_nodebug(x)     (__pa_nodebug(x) | sme_me_mask)
  48
  49 #endif  /* __ASSEMBLY__ */
  50
  51 #endif  /* __X86_MEM_ENCRYPT_H__ */