MdePkg/Include/Protocol/SmmAccess2.h

   1 /** @file
   2   EFI SMM Access2 Protocol as defined in the PI 1.2 specification.
   3
   4   This protocol is used to control the visibility of the SMRAM on the platform.
   5   It abstracts the location and characteristics of SMRAM.  The expectation is
   6   that the north bridge or memory controller would publish this protocol.
   7
   8   The principal functionality found in the memory controller includes the following:
   9   - Exposing the SMRAM to all non-SMM agents, or the "open" state
  10   - Shrouding the SMRAM to all but the SMM agents, or the "closed" state
  11   - Preserving the system integrity, or "locking" the SMRAM, such that the settings cannot be
  12     perturbed by either boot service or runtime agents
  13
  14   Copyright (c) 2009, Intel Corporation
  15   All rights reserved. This program and the accompanying materials
  16   are licensed and made available under the terms and conditions of the BSD License
  17   which accompanies this distribution.  The full text of the license may be found at
  18   http://opensource.org/licenses/bsd-license.php
  19
  20   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  21   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  22
  23 **/
  24
  25 #ifndef _SMM_ACCESS2_H_
  26 #define _SMM_ACCESS2_H_
  27
  28 #include <PiDxe.h>
  29
  30 ///
  31 /// Note:
  32 ///   To avoid name conflict between PI and Framework SMM spec, the following names defined
  33 ///   in PI 1.2 SMM spec are renamed. These renamings are not yet in a public PI spec and errta.
  34 ///
  35 ///   EFI_SMM_OPEN         -> EFI_SMM_OPEN2
  36 ///   EFI_SMM_CLOSE        -> EFI_SMM_CLOSE2
  37 ///   EFI_SMM_LOCK         -> EFI_SMM_LOCK2
  38 ///   EFI_SMM_CAPABILITIES -> EFI_SMM_CAPABILITIES2
  39 ///
  40
  41 #define EFI_SMM_ACCESS2_PROTOCOL_GUID \
  42   { \
  43      0xc2702b74, 0x800c, 0x4131, {0x87, 0x46, 0x8f, 0xb5, 0xb8, 0x9c, 0xe4, 0xac } \
  44   }
  45
  46 ///
  47 /// SMRAM states and capabilities
  48 ///
  49 #define EFI_SMRAM_OPEN                  0x00000001
  50 #define EFI_SMRAM_CLOSED                0x00000002
  51 #define EFI_SMRAM_LOCKED                0x00000004
  52 #define EFI_CACHEABLE                   0x00000008
  53 #define EFI_ALLOCATED                   0x00000010
  54 #define EFI_NEEDS_TESTING               0x00000020
  55 #define EFI_NEEDS_ECC_INITIALIZATION    0x00000040
  56
  57 ///
  58 /// Structure describing a SMRAM region and its accessibility attributes
  59 ///
  60 typedef struct {
  61   ///
  62   /// Designates the physical address of the SMRAM in memory. This view of memory is
  63   /// the same as seen by I/O-based agents, for example, but it may not be the address seen
  64   /// by the processors.
  65   ///
  66   EFI_PHYSICAL_ADDRESS  PhysicalStart;
  67   ///
  68   /// Designates the address of the SMRAM, as seen by software executing on the
  69   /// processors. This address may or may not match PhysicalStart.
  70   ///
  71   EFI_PHYSICAL_ADDRESS  CpuStart;
  72   ///
  73   /// Describes the number of bytes in the SMRAM region.
  74   ///
  75   UINT64                PhysicalSize;
  76   ///
  77   /// Describes the accessibility attributes of the SMRAM.  These attributes include the
  78   /// hardware state (e.g., Open/Closed/Locked), capability (e.g., cacheable), logical
  79   /// allocation (e.g., allocated), and pre-use initialization (e.g., needs testing/ECC
  80   /// initialization).
  81   ///
  82   UINT64                RegionState;
  83 } EFI_SMRAM_DESCRIPTOR;
  84
  85 typedef struct _EFI_SMM_ACCESS2_PROTOCOL  EFI_SMM_ACCESS2_PROTOCOL;
  86
  87 /**
  88   Opens the SMRAM area to be accessible by a boot-service driver.
  89
  90   This function "opens" SMRAM so that it is visible while not inside of SMM. The function should
  91   return EFI_UNSUPPORTED if the hardware does not support hiding of SMRAM. The function
  92   should return EFI_DEVICE_ERROR if the SMRAM configuration is locked.
  93
  94   @param[in] This           The EFI_SMM_ACCESS2_PROTOCOL instance.
  95
  96   @retval EFI_SUCCESS       The operation was successful.
  97   @retval EFI_UNSUPPORTED   The system does not support opening and closing of SMRAM.
  98   @retval EFI_DEVICE_ERROR  SMRAM cannot be opened, perhaps because it is locked.
  99 **/
 100 typedef
 101 EFI_STATUS
 102 (EFIAPI *EFI_SMM_OPEN2)(
 103   IN EFI_SMM_ACCESS2_PROTOCOL  *This
 104   );
 105
 106 /**
 107   Inhibits access to the SMRAM.
 108
 109   This function "closes" SMRAM so that it is not visible while outside of SMM. The function should
 110   return EFI_UNSUPPORTED if the hardware does not support hiding of SMRAM.
 111
 112   @param[in] This           The EFI_SMM_ACCESS2_PROTOCOL instance.
 113
 114   @retval EFI_SUCCESS       The operation was successful.
 115   @retval EFI_UNSUPPORTED   The system does not support opening and closing of SMRAM.
 116   @retval EFI_DEVICE_ERROR  SMRAM cannot be closed.
 117 **/
 118 typedef
 119 EFI_STATUS
 120 (EFIAPI *EFI_SMM_CLOSE2)(
 121   IN EFI_SMM_ACCESS2_PROTOCOL  *This
 122   );
 123
 124 /**
 125   Inhibits access to the SMRAM.
 126
 127   This function prohibits access to the SMRAM region.  This function is usually implemented such
 128   that it is a write-once operation.
 129
 130   @param[in] This          The EFI_SMM_ACCESS2_PROTOCOL instance.
 131
 132   @retval EFI_SUCCESS      The device was successfully locked.
 133   @retval EFI_UNSUPPORTED  The system does not support locking of SMRAM.
 134 **/
 135 typedef
 136 EFI_STATUS
 137 (EFIAPI *EFI_SMM_LOCK2)(
 138   IN EFI_SMM_ACCESS2_PROTOCOL  *This
 139   );
 140
 141 /**
 142   Queries the memory controller for the possible regions that will support SMRAM.
 143
 144   @param[in]     This           The EFI_SMM_ACCESS2_PROTOCOL instance.
 145   @param[in,out] SmramMapSize   A pointer to the size, in bytes, of the SmramMemoryMap buffer.
 146   @param[in,out] SmramMap       A pointer to the buffer in which firmware places the current memory map.
 147
 148   @retval EFI_SUCCESS           The chipset supported the given resource.
 149   @retval EFI_BUFFER_TOO_SMALL  The SmramMap parameter was too small.  The current buffer size
 150                                 needed to hold the memory map is returned in SmramMapSize.
 151 **/
 152 typedef
 153 EFI_STATUS
 154 (EFIAPI *EFI_SMM_CAPABILITIES2)(
 155   IN CONST EFI_SMM_ACCESS2_PROTOCOL  *This,
 156   IN OUT UINTN                       *SmramMapSize,
 157   IN OUT EFI_SMRAM_DESCRIPTOR        *SmramMap
 158   );
 159
 160 ///
 161 ///  EFI SMM Access2 Protocol is used to control the visibility of the SMRAM on the platform.
 162 ///  It abstracts the location and characteristics of SMRAM.  The expectation is
 163 ///  that the north bridge or memory controller would publish this protocol.
 164 ///
 165 struct _EFI_SMM_ACCESS2_PROTOCOL {
 166   EFI_SMM_OPEN2          Open;
 167   EFI_SMM_CLOSE2         Close;
 168   EFI_SMM_LOCK2          Lock;
 169   EFI_SMM_CAPABILITIES2  GetCapabilities;
 170   ///
 171   /// Indicates the current state of the SMRAM. Set to TRUE if SMRAM is locked.
 172   ///
 173   BOOLEAN               LockState;
 174   ///
 175   /// Indicates the current state of the SMRAM. Set to TRUE if SMRAM is open.
 176   ///
 177   BOOLEAN               OpenState;
 178 };
 179
 180 extern EFI_GUID gEfiSmmAccess2ProtocolGuid;
 181
 182 #endif
 183