OvmfPkg: Apply uncrustify changes

[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 <Library/BaseLib.h>\r
#include <Library/IoLib.h>\r
#include <Library/DebugLib.h>\r
#include <Library/QemuFwCfgLib.h>\r
#include <Library/MemEncryptSevLib.h>\r
\r
#include "QemuFwCfgLibInternal.h"\r
\r
STATIC BOOLEAN  mQemuFwCfgSupported = FALSE;\r
STATIC BOOLEAN  mQemuFwCfgDmaSupported;\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
RETURN_STATUS\r
EFIAPI\r
QemuFwCfgInitialize (\r
  VOID\r
  )\r
{\r
  UINT32  Signature;\r
  UINT32  Revision;\r
\r
  //\r
  // Enable the access routines while probing to see if it is supported.\r
  // For probing we always use the IO Port (IoReadFifo8()) access method.\r
  //\r
  mQemuFwCfgSupported    = TRUE;\r
  mQemuFwCfgDmaSupported = FALSE;\r
\r
  QemuFwCfgSelectItem (QemuFwCfgItemSignature);\r
  Signature = QemuFwCfgRead32 ();\r
  DEBUG ((DEBUG_INFO, "FW CFG Signature: 0x%x\n", Signature));\r
  QemuFwCfgSelectItem (QemuFwCfgItemInterfaceVersion);\r
  Revision = QemuFwCfgRead32 ();\r
  DEBUG ((DEBUG_INFO, "FW CFG Revision: 0x%x\n", Revision));\r
  if ((Signature != SIGNATURE_32 ('Q', 'E', 'M', 'U')) ||\r
      (Revision < 1)\r
      )\r
  {\r
    DEBUG ((DEBUG_INFO, "QemuFwCfg interface not supported.\n"));\r
    mQemuFwCfgSupported = FALSE;\r
    return RETURN_SUCCESS;\r
  }\r
\r
  if ((Revision & FW_CFG_F_DMA) == 0) {\r
    DEBUG ((DEBUG_INFO, "QemuFwCfg interface (IO Port) is supported.\n"));\r
  } else {\r
    //\r
    // If SEV is enabled then we do not support DMA operations in PEI phase.\r
    // This is mainly because DMA in SEV guest requires using bounce buffer\r
    // (which need to allocate dynamic memory and allocating a PAGE size'd\r
    // buffer can be challenge in PEI phase)\r
    //\r
    if (MemEncryptSevIsEnabled ()) {\r
      DEBUG ((DEBUG_INFO, "SEV: QemuFwCfg fallback to IO Port interface.\n"));\r
    } else {\r
      mQemuFwCfgDmaSupported = TRUE;\r
      DEBUG ((DEBUG_INFO, "QemuFwCfg interface (DMA) is supported.\n"));\r
    }\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
  return mQemuFwCfgSupported;\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
  return mQemuFwCfgDmaSupported;\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
  // SEV does not support DMA operations in PEI stage, we should\r
  // not have reached here.\r
  //\r
  ASSERT (!MemEncryptSevIsEnabled ());\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