MdeModulePkg/Include/Guid/PiSmmCommunicationRegionTable.h

   1 /** @file
   2
   3 Copyright (c) 2015 - 2018, Intel Corporation. All rights reserved.<BR>
   4 SPDX-License-Identifier: BSD-2-Clause-Patent
   5
   6 **/
   7
   8 #ifndef _PI_SMM_COMMUNICATION_REGION_TABLE_H_
   9 #define _PI_SMM_COMMUNICATION_REGION_TABLE_H_
  10
  11 #define EDKII_PI_SMM_COMMUNICATION_REGION_TABLE_GUID {\
  12   0x4e28ca50, 0xd582, 0x44ac, {0xa1, 0x1f, 0xe3, 0xd5, 0x65, 0x26, 0xdb, 0x34} \
  13 }
  14
  15 //
  16 // This table to declare the generic SMM communication buffer location.
  17 // If this table is present, it means the SMM communication buffer is restricted to
  18 // EfiReservedMemoryType, EfiACPIMemoryNVS, or EfiRuntimeServicesData.
  19 //
  20 // This table is installed to UEFI configuration table by generic driver
  21 // or platform driver, at early DXE phase.
  22 //
  23 // The EFI_MEMORY_DESCRIPTOR entry must contain at least one entry.
  24 // The entries must be normal memory region in EfiReservedMemoryType, EfiACPIMemoryNVS,
  25 // or EfiRuntimeServicesData.
  26 // If the Entry.Type is EfiConventionalMemory, it means this entry is free to use.
  27 // If the Entry.Type is other, it means this entry is occupied.
  28 //
  29 // Any non-SMM component may put communication data there, then use
  30 // UEFI defined SMM Communication ACPI Table, or PI defined EFI_SMM_COMMUNICATION_PROTOCOL
  31 // to communicate with SMI handler. The process is:
  32 // 1) Find an entry whose type is EfiConventional.
  33 // 2) Change type to be EfiReservedMemoryType before use.
  34 // 3) Use it.
  35 // 4) Restore type be EfiConventional.
  36 //    The step 2) must be performed as an atomic transaction, if there might be conflict during runtime.
  37 //    For example, on IA-32/x64 platforms, this can be done using the CMPXCHG CPU instruction.
  38 //    If there is guarantee on no conflict during boot time, these steps can be skipped.
  39 //    For example, DXE, UEFI driver and UEFI application runs in sequence.
  40 //
  41 // For example, FPDT driver can use this communication buffer to get SMM
  42 // performance data in SMM. Profile driver can use this communication buffer
  43 // to get SMM profile data in SMM.
  44 //
  45 typedef struct {
  46   UINT32                Version;
  47   UINT32                NumberOfEntries;
  48   UINT32                DescriptorSize;
  49   UINT32                Reserved;
  50 //EFI_MEMORY_DESCRIPTOR Entry[1];
  51 } EDKII_PI_SMM_COMMUNICATION_REGION_TABLE;
  52
  53 #define EDKII_PI_SMM_COMMUNICATION_REGION_TABLE_VERSION  0x00000001
  54
  55 extern EFI_GUID gEdkiiPiSmmCommunicationRegionTableGuid;
  56
  57 #endif