OvmfPkg/IoMmuDxe: Unmap(): recycle MAP_INFO after BusMasterCommonBuffer[64]

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

/** @file\r
\r
  Stateless fw_cfg library implementation.\r
\r
  Clients must call QemuFwCfgIsAvailable() first.\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
  This program and the accompanying materials are licensed and made available\r
  under the terms and conditions of the BSD License which accompanies this\r
  distribution.  The full text of the license may be found at\r
  http://opensource.org/licenses/bsd-license.php\r
\r
  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT\r
  WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
**/\r
\r
#include <Library/DebugLib.h>\r
#include <Library/QemuFwCfgLib.h>\r
\r
#include "QemuFwCfgLibInternal.h"\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
  UINT32 Signature;\r
  UINT32 Revision;\r
\r
  QemuFwCfgSelectItem (QemuFwCfgItemSignature);\r
  Signature = QemuFwCfgRead32 ();\r
  DEBUG ((EFI_D_INFO, "FW CFG Signature: 0x%x\n", Signature));\r
  QemuFwCfgSelectItem (QemuFwCfgItemInterfaceVersion);\r
  Revision = QemuFwCfgRead32 ();\r
  DEBUG ((EFI_D_INFO, "FW CFG Revision: 0x%x\n", Revision));\r
  if ((Signature != SIGNATURE_32 ('Q', 'E', 'M', 'U')) ||\r
      (Revision < 1)\r
     ) {\r
    DEBUG ((EFI_D_INFO, "QemuFwCfg interface not supported.\n"));\r
    return FALSE;\r
  }\r
\r
  DEBUG ((EFI_D_INFO, "QemuFwCfg interface is supported.\n"));\r
  return TRUE;\r
}\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
  //\r
  // We always return TRUE, because the consumer of this library ought to have\r
  // called QemuFwCfgIsAvailable before making other calls which would hit this\r
  // path.\r
  //\r
  return TRUE;\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 FALSE;\r
}\r
\r
/**\r
\r
 Returns a boolean indicating whether SEV is enabled\r
\r
 @retval    TRUE    SEV is enabled\r
 @retval    FALSE   SEV is disabled\r
**/\r
BOOLEAN\r
InternalQemuFwCfgSevIsEnabled (\r
  VOID\r
  )\r
{\r
  //\r
  // DMA is not supported in SEC phase hence SEV support is irrelevant\r
  //\r
  return FALSE;\r
}\r
\r
/**\r
 Allocate a bounce buffer for SEV DMA.\r
\r
  @param[in]     NumPage  Number of pages.\r
  @param[out]    Buffer   Allocated DMA Buffer pointer\r
\r
**/\r
VOID\r
InternalQemuFwCfgSevDmaAllocateBuffer (\r
  OUT    VOID     **Buffer,\r
  IN     UINT32   NumPages\r
  )\r
{\r
  //\r
  // We should never reach here\r
  //\r
  ASSERT (FALSE);\r
}\r
\r
/**\r
 Free the DMA buffer allocated using InternalQemuFwCfgSevDmaAllocateBuffer\r
\r
  @param[in]     NumPage  Number of pages.\r
  @param[in]     Buffer   DMA Buffer pointer\r
\r
**/\r
VOID\r
InternalQemuFwCfgSevDmaFreeBuffer (\r
  IN     VOID     *Buffer,\r
  IN     UINT32   NumPages\r
  )\r
{\r
  //\r
  // We should never reach here\r
  //\r
  ASSERT (FALSE);\r
}\r