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/** @file
This is the driver that publishes the SMM Access Protocol
instance for System Agent.
Copyright (c) 1999 - 2016, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php.
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
#include "SmmAccessDriver.h"
#include <Library/BaseMemoryLib.h>
#include <Library/HobLib.h>
#include <Library/DebugLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/UefiDriverEntryPoint.h>
#include <Guid/SmramMemoryReserve.h>
static SMM_ACCESS_PRIVATE_DATA mSmmAccess;
/**
This is the standard EFI driver point that detects
whether there is an GMCH815 chipset in the system
and if so, installs an SMM Access Protocol
@param[in] ImageHandle Handle for the image of this driver
@param[in] SystemTable Pointer to the EFI System Table
@retval EFI_SUCCESS Protocol successfully started and installed
@retval EFI_UNSUPPORTED Protocol can't be started
**/
EFI_STATUS
EFIAPI
SmmAccessDriverEntryPoint(
IN EFI_HANDLE ImageHandle,
IN EFI_SYSTEM_TABLE *SystemTable
)
{
EFI_STATUS Status;
UINTN Index;
EFI_SMRAM_HOB_DESCRIPTOR_BLOCK *DescriptorBlock;
VOID *GuidHob;
//
// Initialize Global variables
//
ZeroMem (&mSmmAccess, sizeof (mSmmAccess));
mSmmAccess.Signature = SMM_ACCESS_PRIVATE_DATA_SIGNATURE;
mSmmAccess.Handle = NULL;
GuidHob = GetFirstGuidHob (&gEfiSmmPeiSmramMemoryReserveGuid);
if (!GuidHob) {
DEBUG ((EFI_D_ERROR, "SmramMemoryReserve HOB not found\n"));
return(EFI_NOT_FOUND);
}
DescriptorBlock = (EFI_SMRAM_HOB_DESCRIPTOR_BLOCK *) ((UINT8 *) GuidHob + sizeof (EFI_HOB_GUID_TYPE));
//
// use the hob to publish SMRAM capabilities
//
for (Index = 0; Index < DescriptorBlock->NumberOfSmmReservedRegions; Index++) {
mSmmAccess.SmramDesc[Index].PhysicalStart =
DescriptorBlock->Descriptor[Index].PhysicalStart;
mSmmAccess.SmramDesc[Index].CpuStart =
DescriptorBlock->Descriptor[Index].CpuStart;
mSmmAccess.SmramDesc[Index].PhysicalSize =
DescriptorBlock->Descriptor[Index].PhysicalSize;
mSmmAccess.SmramDesc[Index].RegionState =
DescriptorBlock->Descriptor[Index].RegionState;
}
mSmmAccess.NumberRegions = Index;
mSmmAccess.SmmAccess.Open = Open;
mSmmAccess.SmmAccess.Close = Close;
mSmmAccess.SmmAccess.Lock = Lock;
mSmmAccess.SmmAccess.GetCapabilities = GetCapabilities;
mSmmAccess.SmmAccess.LockState = FALSE;
mSmmAccess.SmmAccess.OpenState = FALSE;
//
// Install our protocol interfaces on the device's handle
//
Status = gBS->InstallMultipleProtocolInterfaces (
&mSmmAccess.Handle,
&gEfiSmmAccess2ProtocolGuid,
&mSmmAccess.SmmAccess,
NULL
);
if (EFI_ERROR (Status)) {
DEBUG ((EFI_D_ERROR, "InstallMultipleProtocolInterfaces returned %r\n", Status));
return EFI_UNSUPPORTED;
}
return EFI_SUCCESS;
}
/**
This routine accepts a request to "open" a region of SMRAM. The
region could be legacy ABSEG, HSEG, or TSEG near top of physical memory.
The use of "open" means that the memory is visible from all boot-service
and SMM agents.
@param[in] This Pointer to the SMM Access Interface
@retval EFI_SUCCESS The region was successfully opened
@retval EFI_DEVICE_ERROR The region could not be opened because locked by chipset
@retval EFI_INVALID_PARAMETER The descriptor index was out of bounds.
**/
EFI_STATUS
EFIAPI
Open (
IN EFI_SMM_ACCESS2_PROTOCOL *This
)
{
SMM_ACCESS_PRIVATE_DATA *SmmAccess;
UINTN Index;
SmmAccess = SMM_ACCESS_PRIVATE_DATA_FROM_THIS(This);
for (Index = 0; Index < SmmAccess->NumberRegions; Index ++) {
if (SmmAccess->SmramDesc[Index].RegionState & EFI_SMRAM_LOCKED) {
DEBUG ((EFI_D_WARN, "Cannot open a locked SMRAM region\n"));
continue;
}
Mmio64AndThenOr (MCH_BASE_ADDRESS, 0x6840, 0, 0xFF);
Mmio64AndThenOr (MCH_BASE_ADDRESS, 0x6848, 0, 0xFF);
SmmAccess->SmramDesc[Index].RegionState &= ~(EFI_SMRAM_CLOSED |EFI_ALLOCATED);
SmmAccess->SmramDesc[Index].RegionState |= EFI_SMRAM_OPEN;
}
SmmAccess->SmmAccess.OpenState = TRUE;
return EFI_SUCCESS;
}
/**
This routine accepts a request to "close" a region of SMRAM. The
region could be legacy AB or TSEG near top of physical memory.
The use of "close" means that the memory is only visible from SMM agents,
not from BS or RT code.
@param[in] This Pointer to the SMM Access Interface
@retval EFI_SUCCESS The region was successfully closed
@retval EFI_DEVICE_ERROR The region could not be closed because locked by chipset
@retval EFI_INVALID_PARAMETER The descriptor index was out of bounds
**/
EFI_STATUS
EFIAPI
Close (
IN EFI_SMM_ACCESS2_PROTOCOL *This
)
{
SMM_ACCESS_PRIVATE_DATA *SmmAccess;
UINTN Index;
SmmAccess = SMM_ACCESS_PRIVATE_DATA_FROM_THIS(This);
for (Index = 0; Index < SmmAccess->NumberRegions; Index ++) {
if (SmmAccess->SmramDesc[Index].RegionState & EFI_SMRAM_LOCKED) {
DEBUG ((EFI_D_WARN, "Cannot close a locked SMRAM region\n"));
continue;
}
if (SmmAccess->SmramDesc[Index].RegionState & EFI_SMRAM_CLOSED) {
continue;
}
SmmAccess->SmramDesc[Index].RegionState &= ~EFI_SMRAM_OPEN;
SmmAccess->SmramDesc[Index].RegionState |= (EFI_SMRAM_CLOSED |EFI_ALLOCATED);
}
SmmAccess->SmmAccess.OpenState = FALSE;
return EFI_SUCCESS;
}
/**
This routine accepts a request to "lock" SMRAM. The
region could be legacy AB or TSEG near top of physical memory.
The use of "lock" means that the memory can no longer be opened
to BS state.
@param[in] This Pointer to the SMM Access Interface
@retval EFI_SUCCESS The region was successfully locked.
@retval EFI_DEVICE_ERROR The region could not be locked because at least one range is still open.
@retval EFI_INVALID_PARAMETER The descriptor index was out of bounds.
**/
EFI_STATUS
EFIAPI
Lock (
IN EFI_SMM_ACCESS2_PROTOCOL *This
)
{
SMM_ACCESS_PRIVATE_DATA *SmmAccess;
UINTN Index;
SmmAccess = SMM_ACCESS_PRIVATE_DATA_FROM_THIS(This);
for (Index = 0; Index < SmmAccess->NumberRegions; Index ++) {
if (SmmAccess->SmmAccess.OpenState) {
DEBUG ((EFI_D_WARN, "Cannot lock SMRAM when SMRAM regions are still open\n"));
return EFI_DEVICE_ERROR;
}
Mmio64AndThenOr (MCH_BASE_ADDRESS, 0x6838, 0, 0x00);
SmmAccess->SmramDesc[Index].RegionState |= EFI_SMRAM_LOCKED;
}
SmmAccess->SmmAccess.LockState = TRUE;
return EFI_SUCCESS;
}
/**
This routine services a user request to discover the SMRAM
capabilities of this platform. This will report the possible
ranges that are possible for SMRAM access, based upon the
memory controller capabilities.
@param[in] This Pointer to the SMRAM Access Interface.
@param[in, out] SmramMapSize Pointer to the variable containing size of the buffer to contain the description information
@param[in, out] SmramMap Buffer containing the data describing the Smram region descriptors
@retval EFI_BUFFER_TOO_SMALL The user did not provide a sufficient buffer.
@retval EFI_SUCCESS The user provided a sufficiently-sized buffer.
**/
EFI_STATUS
EFIAPI
GetCapabilities (
IN CONST EFI_SMM_ACCESS2_PROTOCOL *This,
IN OUT UINTN *SmramMapSize,
IN OUT EFI_SMRAM_DESCRIPTOR *SmramMap
)
{
EFI_STATUS Status;
SMM_ACCESS_PRIVATE_DATA *SmmAccess;
UINTN NecessaryBufferSize;
SmmAccess = SMM_ACCESS_PRIVATE_DATA_FROM_THIS(This);
NecessaryBufferSize = SmmAccess->NumberRegions * sizeof (EFI_SMRAM_DESCRIPTOR);
if (*SmramMapSize < NecessaryBufferSize) {
if (*SmramMapSize != 0) {
DEBUG((EFI_D_WARN, "SMRAM Map Buffer too small\n"));
}
Status = EFI_BUFFER_TOO_SMALL;
} else {
CopyMem (SmramMap, SmmAccess->SmramDesc, NecessaryBufferSize);
DEBUG ((EFI_D_INFO, "SMRAM Map Buffer installed complete\n"));
Status = EFI_SUCCESS;
}
*SmramMapSize = NecessaryBufferSize;
return Status;
}
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