UefiCpuPkg: Move AsmRelocateApLoopStart from Mpfuncs.nasm to AmdSev.nasm

[mirror_edk2.git] / OvmfPkg / Library / QemuFwCfgLib / QemuFwCfgPei.c

/** @file\r
\r
  Stateful and implicitly initialized fw_cfg library implementation.\r
\r
  Copyright (C) 2013, Red Hat, Inc.\r
  Copyright (c) 2011 - 2013, Intel Corporation. All rights reserved.<BR>\r
  Copyright (c) 2017, Advanced Micro Devices. All rights reserved.<BR>\r
\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
**/\r
\r
#include <PiPei.h>\r
#include <Library/BaseLib.h>\r
#include <Library/DebugLib.h>\r
#include <Library/HobLib.h>\r
#include <Library/IoLib.h>\r
#include <Library/PlatformInitLib.h>\r
#include <Library/QemuFwCfgLib.h>\r
#include <WorkArea.h>\r
\r
#include "QemuFwCfgLibInternal.h"\r
\r
/**\r
  Check if it is Tdx guest\r
\r
  @retval    TRUE   It is Tdx guest\r
  @retval    FALSE  It is not Tdx guest\r
**/\r
STATIC\r
BOOLEAN\r
QemuFwCfgIsCcGuest (\r
  VOID\r
  )\r
{\r
  CONFIDENTIAL_COMPUTING_WORK_AREA_HEADER  *CcWorkAreaHeader;\r
\r
  CcWorkAreaHeader = (CONFIDENTIAL_COMPUTING_WORK_AREA_HEADER *)FixedPcdGet32 (PcdOvmfWorkAreaBase);\r
  return (CcWorkAreaHeader != NULL && CcWorkAreaHeader->GuestType != CcGuestTypeNonEncrypted);\r
}\r
\r
/**\r
  Returns a boolean indicating if the firmware configuration interface\r
  is available or not.\r
\r
  This function may change fw_cfg state.\r
\r
  @retval    TRUE   The interface is available\r
  @retval    FALSE  The interface is not available\r
\r
**/\r
BOOLEAN\r
EFIAPI\r
QemuFwCfgIsAvailable (\r
  VOID\r
  )\r
{\r
  return InternalQemuFwCfgIsAvailable ();\r
}\r
\r
STATIC\r
VOID\r
QemuFwCfgProbe (\r
  BOOLEAN  *Supported,\r
  BOOLEAN  *DmaSupported\r
  )\r
{\r
  UINT32   Signature;\r
  UINT32   Revision;\r
  BOOLEAN  CcGuest;\r
\r
  // Use direct Io* calls for probing to avoid recursion.\r
  IoWrite16 (FW_CFG_IO_SELECTOR, (UINT16)QemuFwCfgItemSignature);\r
  IoReadFifo8 (FW_CFG_IO_DATA, sizeof Signature, &Signature);\r
  IoWrite16 (FW_CFG_IO_SELECTOR, (UINT16)QemuFwCfgItemInterfaceVersion);\r
  IoReadFifo8 (FW_CFG_IO_DATA, sizeof Revision, &Revision);\r
  CcGuest = QemuFwCfgIsCcGuest ();\r
\r
  *Supported    = FALSE;\r
  *DmaSupported = FALSE;\r
  if ((Signature == SIGNATURE_32 ('Q', 'E', 'M', 'U')) && (Revision >= 1)) {\r
    *Supported = TRUE;\r
    if ((Revision & FW_CFG_F_DMA) && !CcGuest) {\r
      *DmaSupported = TRUE;\r
    }\r
  }\r
\r
  DEBUG ((\r
    DEBUG_INFO,\r
    "%a: Supported %d, DMA %d\n",\r
    __func__,\r
    *Supported,\r
    *DmaSupported\r
    ));\r
}\r
\r
STATIC\r
EFI_HOB_PLATFORM_INFO *\r
QemuFwCfgGetPlatformInfo (\r
  VOID\r
  )\r
{\r
  EFI_HOB_PLATFORM_INFO  *PlatformInfoHob;\r
  EFI_HOB_GUID_TYPE      *GuidHob;\r
\r
  GuidHob = GetFirstGuidHob (&gUefiOvmfPkgPlatformInfoGuid);\r
  if (GuidHob == NULL) {\r
    return NULL;\r
  }\r
\r
  PlatformInfoHob = (EFI_HOB_PLATFORM_INFO *)GET_GUID_HOB_DATA (GuidHob);\r
\r
  if (!PlatformInfoHob->QemuFwCfgChecked) {\r
    QemuFwCfgProbe (\r
      &PlatformInfoHob->QemuFwCfgSupported,\r
      &PlatformInfoHob->QemuFwCfgDmaSupported\r
      );\r
    PlatformInfoHob->QemuFwCfgChecked = TRUE;\r
  }\r
\r
  return PlatformInfoHob;\r
}\r
\r
RETURN_STATUS\r
EFIAPI\r
QemuFwCfgInitialize (\r
  VOID\r
  )\r
{\r
  return RETURN_SUCCESS;\r
}\r
\r
/**\r
  Returns a boolean indicating if the firmware configuration interface is\r
  available for library-internal purposes.\r
\r
  This function never changes fw_cfg state.\r
\r
  @retval    TRUE   The interface is available internally.\r
  @retval    FALSE  The interface is not available internally.\r
**/\r
BOOLEAN\r
InternalQemuFwCfgIsAvailable (\r
  VOID\r
  )\r
{\r
  EFI_HOB_PLATFORM_INFO  *PlatformInfoHob = QemuFwCfgGetPlatformInfo ();\r
\r
  return PlatformInfoHob->QemuFwCfgSupported;\r
}\r
\r
/**\r
  Returns a boolean indicating whether QEMU provides the DMA-like access method\r
  for fw_cfg.\r
\r
  @retval    TRUE   The DMA-like access method is available.\r
  @retval    FALSE  The DMA-like access method is unavailable.\r
**/\r
BOOLEAN\r
InternalQemuFwCfgDmaIsAvailable (\r
  VOID\r
  )\r
{\r
  EFI_HOB_PLATFORM_INFO  *PlatformInfoHob = QemuFwCfgGetPlatformInfo ();\r
\r
  return PlatformInfoHob->QemuFwCfgDmaSupported;\r
}\r
\r
/**\r
  Transfer an array of bytes, or skip a number of bytes, using the DMA\r
  interface.\r
\r
  @param[in]     Size     Size in bytes to transfer or skip.\r
\r
  @param[in,out] Buffer   Buffer to read data into or write data from. Ignored,\r
                          and may be NULL, if Size is zero, or Control is\r
                          FW_CFG_DMA_CTL_SKIP.\r
\r
  @param[in]     Control  One of the following:\r
                          FW_CFG_DMA_CTL_WRITE - write to fw_cfg from Buffer.\r
                          FW_CFG_DMA_CTL_READ  - read from fw_cfg into Buffer.\r
                          FW_CFG_DMA_CTL_SKIP  - skip bytes in fw_cfg.\r
**/\r
VOID\r
InternalQemuFwCfgDmaBytes (\r
  IN     UINT32  Size,\r
  IN OUT VOID    *Buffer OPTIONAL,\r
  IN     UINT32  Control\r
  )\r
{\r
  volatile FW_CFG_DMA_ACCESS  Access;\r
  UINT32                      AccessHigh, AccessLow;\r
  UINT32                      Status;\r
\r
  ASSERT (\r
    Control == FW_CFG_DMA_CTL_WRITE || Control == FW_CFG_DMA_CTL_READ ||\r
    Control == FW_CFG_DMA_CTL_SKIP\r
    );\r
\r
  if (Size == 0) {\r
    return;\r
  }\r
\r
  //\r
  // TDX does not support DMA operations in PEI stage, we should\r
  // not have reached here.\r
  //\r
  ASSERT (!QemuFwCfgIsCcGuest ());\r
\r
  Access.Control = SwapBytes32 (Control);\r
  Access.Length  = SwapBytes32 (Size);\r
  Access.Address = SwapBytes64 ((UINTN)Buffer);\r
\r
  //\r
  // Delimit the transfer from (a) modifications to Access, (b) in case of a\r
  // write, from writes to Buffer by the caller.\r
  //\r
  MemoryFence ();\r
\r
  //\r
  // Start the transfer.\r
  //\r
  AccessHigh = (UINT32)RShiftU64 ((UINTN)&Access, 32);\r
  AccessLow  = (UINT32)(UINTN)&Access;\r
  IoWrite32 (FW_CFG_IO_DMA_ADDRESS, SwapBytes32 (AccessHigh));\r
  IoWrite32 (FW_CFG_IO_DMA_ADDRESS + 4, SwapBytes32 (AccessLow));\r
\r
  //\r
  // Don't look at Access.Control before starting the transfer.\r
  //\r
  MemoryFence ();\r
\r
  //\r
  // Wait for the transfer to complete.\r
  //\r
  do {\r
    Status = SwapBytes32 (Access.Control);\r
    ASSERT ((Status & FW_CFG_DMA_CTL_ERROR) == 0);\r
  } while (Status != 0);\r
\r
  //\r
  // After a read, the caller will want to use Buffer.\r
  //\r
  MemoryFence ();\r
}\r