MdeModulePkg/Include/Guid/PiSmmCommunicationRegionTable.h

   1 /** @file
   2
   3 Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
   4 This program and the accompanying materials are licensed and made available under
   5 the terms and conditions of the BSD License that accompanies this distribution.
   6 The full text of the license may be found at
   7 http://opensource.org/licenses/bsd-license.php.
   8
   9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11
  12 **/
  13
  14 #ifndef _PI_SMM_COMMUNICATION_REGION_TABLE_H_
  15 #define _PI_SMM_COMMUNICATION_REGION_TABLE_H_
  16
  17 #define EDKII_PI_SMM_COMMUNICATION_REGION_TABLE_GUID {\
  18   0x4e28ca50, 0xd582, 0x44ac, {0xa1, 0x1f, 0xe3, 0xd5, 0x65, 0x26, 0xdb, 0x34} \
  19 }
  20
  21 //
  22 // This table to declare the generic SMM communication buffer location.
  23 // If this table is present, it means the SMM communication buffer is restricted to
  24 // EfiReservedMemoryType, EfiACPIMemoryNVS, or EfiRuntimeServicesData.
  25 //
  26 // This table is installed to UEFI configuration table by generic driver
  27 // or platform driver, at early DXE phase.
  28 //
  29 // The EFI_MEMORY_DESCRIPTOR entry must contain at least one entry.
  30 // The entries must be normal memory region in EfiReservedMemoryType, EfiACPIMemoryNVS,
  31 // or EfiRuntimeServicesData.
  32 // If the Entry.Type is EfiConventionalMemory, it means this entry is free to use.
  33 // If the Entry.Type is other, it means this entry is occupied.
  34 //
  35 // Any non-SMM component may put communication data there, then use
  36 // UEFI defined SMM Communication ACPI Table, or PI defined EFI_SMM_COMMUNICATION_PROTOCOL
  37 // to communicate with SMI handler. The process is:
  38 // 1) Find an entry whose type is EfiConventional.
  39 // 2) Change type to be EfiReservedMemoryType before use.
  40 // 3) Use it.
  41 // 4) Restore type be EfiConventional.
  42 //    The step 2) must be performed as an atomic transaction, if there might be conflict during runtime.
  43 //    For example, on IA-32/x64 platforms, this can be done using the CMPXCHG CPU instruction.
  44 //    If there is guarantee on no conflict during boot time, these steps can be skipped.
  45 //    For example, DXE, UEFI driver and UEFI application runs in sequence.
  46 //
  47 // For example, FPDT driver can use this communication buffer to get SMM
  48 // performance data in SMM. Profile driver can use this communication buffer
  49 // to get SMM profile data in SMM.
  50 //
  51 typedef struct {
  52   UINT32                Version;
  53   UINT32                NumberOfEntries;
  54   UINT32                DescriptorSize;
  55   UINT32                Reserved;
  56 //EFI_MEMORY_DESCRIPTOR Entry[1];
  57 } EDKII_PI_SMM_COMMUNICATION_REGION_TABLE;
  58
  59 #define EDKII_PI_SMM_COMMUNICATION_REGION_TABLE_VERSION  0x00000001
  60
  61 extern EFI_GUID gEdkiiPiSmmCommunicationRegionTableGuid;
  62
  63 #endif