include/linux/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 __MEM_ENCRYPT_H__
  14 #define __MEM_ENCRYPT_H__
  15
  16 #ifndef __ASSEMBLY__
  17
  18 #ifdef CONFIG_ARCH_HAS_MEM_ENCRYPT
  19
  20 #include <asm/mem_encrypt.h>
  21
  22 #else   /* !CONFIG_ARCH_HAS_MEM_ENCRYPT */
  23
  24 #define sme_me_mask     0ULL
  25
  26 static inline bool sme_active(void) { return false; }
  27 static inline bool sev_active(void) { return false; }
  28
  29 #endif  /* CONFIG_ARCH_HAS_MEM_ENCRYPT */
  30
  31 static inline bool mem_encrypt_active(void)
  32 {
  33         return sme_me_mask;
  34 }
  35
  36 static inline u64 sme_get_me_mask(void)
  37 {
  38         return sme_me_mask;
  39 }
  40
  41 #ifdef CONFIG_AMD_MEM_ENCRYPT
  42 /*
  43  * The __sme_set() and __sme_clr() macros are useful for adding or removing
  44  * the encryption mask from a value (e.g. when dealing with pagetable
  45  * entries).
  46  */
  47 #define __sme_set(x)            ((x) | sme_me_mask)
  48 #define __sme_clr(x)            ((x) & ~sme_me_mask)
  49 #else
  50 #define __sme_set(x)            (x)
  51 #define __sme_clr(x)            (x)
  52 #endif
  53
  54 #endif  /* __ASSEMBLY__ */
  55
  56 #endif  /* __MEM_ENCRYPT_H__ */