LXR linux/include/linux/mem

   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 __MEM_ENCRYPT_H__
  11#define __MEM_ENCRYPT_H__
  12
  13#ifndef __ASSEMBLY__
  14
  15#ifdef CONFIG_ARCH_HAS_MEM_ENCRYPT
  16
  17#include <asm/mem_encrypt.h>
  18
  19#else   /* !CONFIG_ARCH_HAS_MEM_ENCRYPT */
  20
  21#define sme_me_mask     0ULL
  22
  23static inline bool sme_active(void) { return false; }
  24static inline bool sev_active(void) { return false; }
  25
  26#endif  /* CONFIG_ARCH_HAS_MEM_ENCRYPT */
  27
  28static inline bool mem_encrypt_active(void)
  29{
  30        return sme_me_mask;
  31}
  32
  33static inline u64 sme_get_me_mask(void)
  34{
  35        return sme_me_mask;
  36}
  37
  38#ifdef CONFIG_AMD_MEM_ENCRYPT
  39/*
  40 * The __sme_set() and __sme_clr() macros are useful for adding or removing
  41 * the encryption mask from a value (e.g. when dealing with pagetable
  42 * entries).
  43 */
  44#define __sme_set(x)            ((x) | sme_me_mask)
  45#define __sme_clr(x)            ((x) & ~sme_me_mask)
  46#else
  47#define __sme_set(x)            (x)
  48#define __sme_clr(x)            (x)
  49#endif
  50
  51#endif  /* __ASSEMBLY__ */
  52
  53#endif  /* __MEM_ENCRYPT_H__ */
  54