MdeModulePkg/PciBusDxe: Fix possible uninitialized use

[mirror_edk2.git] / MdeModulePkg / Bus / Pci / NvmExpressPei / DevicePath.c

/** @file\r
  The device path help function.\r
\r
  Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>\r
\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
#include "NvmExpressPei.h"\r
\r
//\r
// Template for an Nvm Express Device Path node\r
//\r
NVME_NAMESPACE_DEVICE_PATH  mNvmeDevicePathNodeTemplate = {\r
  {        // Header\r
    MESSAGING_DEVICE_PATH,\r
    MSG_NVME_NAMESPACE_DP,\r
    {\r
      (UINT8) (sizeof (NVME_NAMESPACE_DEVICE_PATH)),\r
      (UINT8) ((sizeof (NVME_NAMESPACE_DEVICE_PATH)) >> 8)\r
    }\r
  },\r
  0x0,     // NamespaceId\r
  0x0      // NamespaceUuid\r
};\r
\r
//\r
// Template for an End of entire Device Path node\r
//\r
EFI_DEVICE_PATH_PROTOCOL  mNvmeEndDevicePathNodeTemplate = {\r
  END_DEVICE_PATH_TYPE,\r
  END_ENTIRE_DEVICE_PATH_SUBTYPE,\r
  {\r
    (UINT8) (sizeof (EFI_DEVICE_PATH_PROTOCOL)),\r
    (UINT8) ((sizeof (EFI_DEVICE_PATH_PROTOCOL)) >> 8)\r
  }\r
};\r
\r
/**\r
  Returns the 16-bit Length field of a device path node.\r
\r
  Returns the 16-bit Length field of the device path node specified by Node.\r
  Node is not required to be aligned on a 16-bit boundary, so it is recommended\r
  that a function such as ReadUnaligned16() be used to extract the contents of\r
  the Length field.\r
\r
  If Node is NULL, then ASSERT().\r
\r
  @param  Node      A pointer to a device path node data structure.\r
\r
  @return The 16-bit Length field of the device path node specified by Node.\r
\r
**/\r
UINTN\r
DevicePathNodeLength (\r
  IN CONST VOID  *Node\r
  )\r
{\r
  ASSERT (Node != NULL);\r
  return ReadUnaligned16 ((UINT16 *)&((EFI_DEVICE_PATH_PROTOCOL *)(Node))->Length[0]);\r
}\r
\r
/**\r
  Returns a pointer to the next node in a device path.\r
\r
  If Node is NULL, then ASSERT().\r
\r
  @param  Node    A pointer to a device path node data structure.\r
\r
  @return a pointer to the device path node that follows the device path node\r
  specified by Node.\r
\r
**/\r
EFI_DEVICE_PATH_PROTOCOL *\r
NextDevicePathNode (\r
  IN CONST VOID  *Node\r
  )\r
{\r
  ASSERT (Node != NULL);\r
  return (EFI_DEVICE_PATH_PROTOCOL *)((UINT8 *)(Node) + DevicePathNodeLength(Node));\r
}\r
\r
/**\r
  Get the size of the current device path instance.\r
\r
  @param[in]  DevicePath             A pointer to the EFI_DEVICE_PATH_PROTOCOL\r
                                     structure.\r
  @param[out] InstanceSize           The size of the current device path instance.\r
  @param[out] EntireDevicePathEnd    Indicate whether the instance is the last\r
                                     one in the device path strucure.\r
\r
  @retval EFI_SUCCESS    The size of the current device path instance is fetched.\r
  @retval Others         Fails to get the size of the current device path instance.\r
\r
**/\r
EFI_STATUS\r
GetDevicePathInstanceSize (\r
  IN  EFI_DEVICE_PATH_PROTOCOL    *DevicePath,\r
  OUT UINTN                       *InstanceSize,\r
  OUT BOOLEAN                     *EntireDevicePathEnd\r
  )\r
{\r
  EFI_DEVICE_PATH_PROTOCOL    *Walker;\r
\r
  if (DevicePath == NULL || InstanceSize == NULL || EntireDevicePathEnd == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  //\r
  // Find the end of the device path instance\r
  //\r
  Walker = DevicePath;\r
  while (Walker->Type != END_DEVICE_PATH_TYPE) {\r
    Walker = NextDevicePathNode (Walker);\r
  }\r
\r
  //\r
  // Check if 'Walker' points to the end of an entire device path\r
  //\r
  if (Walker->SubType == END_ENTIRE_DEVICE_PATH_SUBTYPE) {\r
    *EntireDevicePathEnd = TRUE;\r
  } else if (Walker->SubType == END_INSTANCE_DEVICE_PATH_SUBTYPE) {\r
    *EntireDevicePathEnd = FALSE;\r
  } else {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  //\r
  // Compute the size of the device path instance\r
  //\r
  *InstanceSize = ((UINTN) Walker - (UINTN) (DevicePath)) + sizeof (EFI_DEVICE_PATH_PROTOCOL);\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Check the validity of the device path of a NVM Express host controller.\r
\r
  @param[in] DevicePath          A pointer to the EFI_DEVICE_PATH_PROTOCOL\r
                                 structure.\r
  @param[in] DevicePathLength    The length of the device path.\r
\r
  @retval EFI_SUCCESS              The device path is valid.\r
  @retval EFI_INVALID_PARAMETER    The device path is invalid.\r
\r
**/\r
EFI_STATUS\r
NvmeIsHcDevicePathValid (\r
  IN EFI_DEVICE_PATH_PROTOCOL    *DevicePath,\r
  IN UINTN                       DevicePathLength\r
  )\r
{\r
  EFI_DEVICE_PATH_PROTOCOL    *Start;\r
  UINTN                       Size;\r
\r
  if (DevicePath == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  //\r
  // Validate the DevicePathLength is big enough to touch the first node.\r
  //\r
  if (DevicePathLength < sizeof (EFI_DEVICE_PATH_PROTOCOL)) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  Start = DevicePath;\r
  while (!(DevicePath->Type == END_DEVICE_PATH_TYPE &&\r
           DevicePath->SubType == END_ENTIRE_DEVICE_PATH_SUBTYPE)) {\r
    DevicePath = NextDevicePathNode (DevicePath);\r
\r
    //\r
    // Prevent overflow and invalid zero in the 'Length' field of a device path\r
    // node.\r
    //\r
    if ((UINTN) DevicePath <= (UINTN) Start) {\r
      return EFI_INVALID_PARAMETER;\r
    }\r
\r
    //\r
    // Prevent touching memory beyond given DevicePathLength.\r
    //\r
    if ((UINTN) DevicePath - (UINTN) Start >\r
        DevicePathLength - sizeof (EFI_DEVICE_PATH_PROTOCOL)) {\r
      return EFI_INVALID_PARAMETER;\r
    }\r
  }\r
\r
  //\r
  // Check if the device path and its size match exactly with each other.\r
  //\r
  Size = ((UINTN) DevicePath - (UINTN) Start) + sizeof (EFI_DEVICE_PATH_PROTOCOL);\r
  if (Size != DevicePathLength) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Build the device path for an Nvm Express device with given namespace identifier\r
  and namespace extended unique identifier.\r
\r
  @param[in]  Private              A pointer to the PEI_NVME_CONTROLLER_PRIVATE_DATA\r
                                   data structure.\r
  @param[in]  NamespaceId          The given namespace identifier.\r
  @param[in]  NamespaceUuid        The given namespace extended unique identifier.\r
  @param[out] DevicePathLength     The length of the device path in bytes specified\r
                                   by DevicePath.\r
  @param[out] DevicePath           The device path of Nvm Express device.\r
\r
  @retval EFI_SUCCESS              The operation succeeds.\r
  @retval EFI_INVALID_PARAMETER    The parameters are invalid.\r
  @retval EFI_OUT_OF_RESOURCES     The operation fails due to lack of resources.\r
\r
**/\r
EFI_STATUS\r
NvmeBuildDevicePath (\r
  IN  PEI_NVME_CONTROLLER_PRIVATE_DATA    *Private,\r
  IN  UINT32                              NamespaceId,\r
  IN  UINT64                              NamespaceUuid,\r
  OUT UINTN                               *DevicePathLength,\r
  OUT EFI_DEVICE_PATH_PROTOCOL            **DevicePath\r
  )\r
{\r
  EFI_DEVICE_PATH_PROTOCOL      *DevicePathWalker;\r
  NVME_NAMESPACE_DEVICE_PATH    *NvmeDeviceNode;\r
\r
  if (DevicePathLength == NULL || DevicePath == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  *DevicePathLength = Private->DevicePathLength + sizeof (NVME_NAMESPACE_DEVICE_PATH);\r
  *DevicePath       = AllocatePool (*DevicePathLength);\r
  if (*DevicePath == NULL) {\r
    *DevicePathLength = 0;\r
    return EFI_OUT_OF_RESOURCES;\r
  }\r
\r
  //\r
  // Construct the host controller part device nodes\r
  //\r
  DevicePathWalker = *DevicePath;\r
  CopyMem (\r
    DevicePathWalker,\r
    Private->DevicePath,\r
    Private->DevicePathLength - sizeof (EFI_DEVICE_PATH_PROTOCOL)\r
    );\r
\r
  //\r
  // Construct the Nvm Express device node\r
  //\r
  DevicePathWalker = (EFI_DEVICE_PATH_PROTOCOL *) ((UINT8 *)DevicePathWalker +\r
                     (Private->DevicePathLength - sizeof (EFI_DEVICE_PATH_PROTOCOL)));\r
  CopyMem (\r
    DevicePathWalker,\r
    &mNvmeDevicePathNodeTemplate,\r
    sizeof (mNvmeDevicePathNodeTemplate)\r
    );\r
  NvmeDeviceNode                = (NVME_NAMESPACE_DEVICE_PATH *)DevicePathWalker;\r
  NvmeDeviceNode->NamespaceId   = NamespaceId;\r
  NvmeDeviceNode->NamespaceUuid = NamespaceUuid;\r
\r
  //\r
  // Construct the end device node\r
  //\r
  DevicePathWalker = (EFI_DEVICE_PATH_PROTOCOL *) ((UINT8 *)DevicePathWalker +\r
                     sizeof (NVME_NAMESPACE_DEVICE_PATH));\r
  CopyMem (\r
    DevicePathWalker,\r
    &mNvmeEndDevicePathNodeTemplate,\r
    sizeof (mNvmeEndDevicePathNodeTemplate)\r
    );\r
\r
  return EFI_SUCCESS;\r
}\r