MdeModulePkg/Universal/SmmCommunicationBufferDxe/SmmCommunicationBufferDxe.c

   1 /** @file
   2 A driver allocates common SMM communication buffer in EfiReservedMemoryType.
   3
   4 This driver allocates common SMM communication buffer in EfiReservedMemoryType,
   5 then it publishes the information to EFI configuration table with
   6 gEdkiiPiSmmCommunicationRegionTableGuid.
   7 Any other driver or application can get the table and know the common
   8 communication buffer.
   9
  10 Copyright (c) 2016, Intel Corporation. All rights reserved.<BR>
  11 SPDX-License-Identifier: BSD-2-Clause-Patent
  12
  13 **/
  14
  15 #include <PiDxe.h>
  16 #include <Library/UefiBootServicesTableLib.h>
  17 #include <Library/UefiRuntimeServicesTableLib.h>
  18 #include <Library/BaseLib.h>
  19 #include <Library/BaseMemoryLib.h>
  20 #include <Library/MemoryAllocationLib.h>
  21 #include <Library/DebugLib.h>
  22 #include <Library/UefiLib.h>
  23 #include <Guid/PiSmmCommunicationRegionTable.h>
  24
  25 #define DEFAULT_COMMON_PI_SMM_COMMUNIATION_REGION_PAGES  4
  26
  27 /**
  28   Entry Point for SMM communication buffer driver.
  29
  30   @param[in] ImageHandle  Image handle of this driver.
  31   @param[in] SystemTable  A Pointer to the EFI System Table.
  32
  33   @retval EFI_SUCEESS
  34   @return Others          Some error occurs.
  35 **/
  36 EFI_STATUS
  37 EFIAPI
  38 SmmCommunicationBufferEntryPoint (
  39   IN EFI_HANDLE        ImageHandle,
  40   IN EFI_SYSTEM_TABLE  *SystemTable
  41   )
  42 {
  43   EFI_STATUS                               Status;
  44   UINT32                                   DescriptorSize;
  45   EDKII_PI_SMM_COMMUNICATION_REGION_TABLE  *PiSmmCommunicationRegionTable;
  46   EFI_MEMORY_DESCRIPTOR                    *Entry;
  47
  48   DescriptorSize = sizeof(EFI_MEMORY_DESCRIPTOR);
  49   //
  50   // Make sure Size != sizeof(EFI_MEMORY_DESCRIPTOR). This will
  51   // prevent people from having pointer math bugs in their code.
  52   // now you have to use *DescriptorSize to make things work.
  53   //
  54   DescriptorSize += sizeof(UINT64) - (DescriptorSize % sizeof (UINT64));
  55
  56   //
  57   // Allocate and fill PiSmmCommunicationRegionTable
  58   //
  59   PiSmmCommunicationRegionTable = AllocateReservedPool (sizeof(EDKII_PI_SMM_COMMUNICATION_REGION_TABLE) + DescriptorSize);
  60   ASSERT(PiSmmCommunicationRegionTable != NULL);
  61   ZeroMem (PiSmmCommunicationRegionTable, sizeof(EDKII_PI_SMM_COMMUNICATION_REGION_TABLE) + DescriptorSize);
  62
  63   PiSmmCommunicationRegionTable->Version         = EDKII_PI_SMM_COMMUNICATION_REGION_TABLE_VERSION;
  64   PiSmmCommunicationRegionTable->NumberOfEntries = 1;
  65   PiSmmCommunicationRegionTable->DescriptorSize  = DescriptorSize;
  66   Entry = (EFI_MEMORY_DESCRIPTOR *)(PiSmmCommunicationRegionTable + 1);
  67   Entry->Type          = EfiConventionalMemory;
  68   Entry->PhysicalStart = (EFI_PHYSICAL_ADDRESS)(UINTN)AllocateReservedPages (DEFAULT_COMMON_PI_SMM_COMMUNIATION_REGION_PAGES);
  69   ASSERT(Entry->PhysicalStart != 0);
  70   Entry->VirtualStart  = 0;
  71   Entry->NumberOfPages = DEFAULT_COMMON_PI_SMM_COMMUNIATION_REGION_PAGES;
  72   Entry->Attribute     = 0;
  73
  74   DEBUG ((EFI_D_INFO, "PiSmmCommunicationRegionTable:(0x%x)\n", PiSmmCommunicationRegionTable));
  75   DEBUG ((EFI_D_INFO, "  Version         - 0x%x\n", PiSmmCommunicationRegionTable->Version));
  76   DEBUG ((EFI_D_INFO, "  NumberOfEntries - 0x%x\n", PiSmmCommunicationRegionTable->NumberOfEntries));
  77   DEBUG ((EFI_D_INFO, "  DescriptorSize  - 0x%x\n", PiSmmCommunicationRegionTable->DescriptorSize));
  78   DEBUG ((EFI_D_INFO, "Entry:(0x%x)\n", Entry));
  79   DEBUG ((EFI_D_INFO, "  Type            - 0x%x\n", Entry->Type));
  80   DEBUG ((EFI_D_INFO, "  PhysicalStart   - 0x%lx\n", Entry->PhysicalStart));
  81   DEBUG ((EFI_D_INFO, "  VirtualStart    - 0x%lx\n", Entry->VirtualStart));
  82   DEBUG ((EFI_D_INFO, "  NumberOfPages   - 0x%lx\n", Entry->NumberOfPages));
  83   DEBUG ((EFI_D_INFO, "  Attribute       - 0x%lx\n", Entry->Attribute));
  84
  85   //
  86   // Publish this table, so that other driver can use the buffer.
  87   //
  88   Status = gBS->InstallConfigurationTable (&gEdkiiPiSmmCommunicationRegionTableGuid, PiSmmCommunicationRegionTable);
  89   ASSERT_EFI_ERROR (Status);
  90
  91   return Status;
  92 }