OvmfPkg: Replace BSD License with BSD+Patent License

[mirror_edk2.git] / OvmfPkg / Library / BasePciCapPciSegmentLib / BasePciCapPciSegmentLib.c

/** @file\r
  Plug a PciSegmentLib backend into PciCapLib, for config space access.\r
\r
  Copyright (C) 2018, Red Hat, Inc.\r
\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
**/\r
\r
#include <IndustryStandard/Pci23.h>\r
\r
#include <Library/BaseLib.h>\r
#include <Library/MemoryAllocationLib.h>\r
#include <Library/PciSegmentLib.h>\r
\r
#include "BasePciCapPciSegmentLib.h"\r
\r
\r
/**\r
  Read the config space of a given PCI device (both normal and extended).\r
\r
  SegmentDevReadConfig() performs as few config space accesses as possible\r
  (without attempting 64-bit wide accesses).\r
\r
  @param[in] PciDevice           Implementation-specific unique representation\r
                                 of the PCI device in the PCI hierarchy.\r
\r
  @param[in] SourceOffset        Source offset in the config space of the PCI\r
                                 device to start reading from.\r
\r
  @param[out] DestinationBuffer  Buffer to store the read data to.\r
\r
  @param[in] Size                The number of bytes to transfer.\r
\r
  @retval RETURN_SUCCESS      Size bytes have been transferred from config\r
                              space to DestinationBuffer.\r
\r
  @retval RETURN_UNSUPPORTED  Accessing Size bytes from SourceOffset exceeds\r
                              the config space limit of the PCI device.\r
                              Although PCI_CAP_DEV_READ_CONFIG allows reading\r
                              fewer than Size bytes in this case,\r
                              SegmentDevReadConfig() will read none.\r
**/\r
STATIC\r
RETURN_STATUS\r
EFIAPI\r
SegmentDevReadConfig (\r
  IN  PCI_CAP_DEV *PciDevice,\r
  IN  UINT16      SourceOffset,\r
  OUT VOID        *DestinationBuffer,\r
  IN  UINT16      Size\r
  )\r
{\r
  SEGMENT_DEV *SegmentDev;\r
  UINT16      ConfigSpaceSize;\r
  UINT64      SourceAddress;\r
\r
  SegmentDev = SEGMENT_DEV_FROM_PCI_CAP_DEV (PciDevice);\r
  ConfigSpaceSize = (SegmentDev->MaxDomain == PciCapNormal ?\r
                     PCI_MAX_CONFIG_OFFSET : PCI_EXP_MAX_CONFIG_OFFSET);\r
  //\r
  // Note that all UINT16 variables below are promoted to INT32, and the\r
  // addition and the comparison is carried out in INT32.\r
  //\r
  if (SourceOffset + Size > ConfigSpaceSize) {\r
    return RETURN_UNSUPPORTED;\r
  }\r
  SourceAddress = PCI_SEGMENT_LIB_ADDRESS (SegmentDev->SegmentNr,\r
                    SegmentDev->BusNr, SegmentDev->DeviceNr,\r
                    SegmentDev->FunctionNr, SourceOffset);\r
  PciSegmentReadBuffer (SourceAddress, Size, DestinationBuffer);\r
  return RETURN_SUCCESS;\r
}\r
\r
\r
/**\r
  Write the config space of a given PCI device (both normal and extended).\r
\r
  SegmentDevWriteConfig() performs as few config space accesses as possible\r
  (without attempting 64-bit wide accesses).\r
\r
  @param[in] PciDevice          Implementation-specific unique representation\r
                                of the PCI device in the PCI hierarchy.\r
\r
  @param[in] DestinationOffset  Destination offset in the config space of the\r
                                PCI device to start writing at.\r
\r
  @param[in] SourceBuffer       Buffer to read the data to be stored from.\r
\r
  @param[in] Size               The number of bytes to transfer.\r
\r
  @retval RETURN_SUCCESS      Size bytes have been transferred from\r
                              SourceBuffer to config space.\r
\r
  @retval RETURN_UNSUPPORTED  Accessing Size bytes at DestinationOffset exceeds\r
                              the config space limit of the PCI device.\r
                              Although PCI_CAP_DEV_WRITE_CONFIG allows writing\r
                              fewer than Size bytes in this case,\r
                              SegmentDevWriteConfig() will write none.\r
**/\r
STATIC\r
RETURN_STATUS\r
EFIAPI\r
SegmentDevWriteConfig (\r
  IN PCI_CAP_DEV *PciDevice,\r
  IN UINT16      DestinationOffset,\r
  IN VOID        *SourceBuffer,\r
  IN UINT16      Size\r
  )\r
{\r
  SEGMENT_DEV *SegmentDev;\r
  UINT16      ConfigSpaceSize;\r
  UINT64      DestinationAddress;\r
\r
  SegmentDev = SEGMENT_DEV_FROM_PCI_CAP_DEV (PciDevice);\r
  ConfigSpaceSize = (SegmentDev->MaxDomain == PciCapNormal ?\r
                     PCI_MAX_CONFIG_OFFSET : PCI_EXP_MAX_CONFIG_OFFSET);\r
  //\r
  // Note that all UINT16 variables below are promoted to INT32, and the\r
  // addition and the comparison is carried out in INT32.\r
  //\r
  if (DestinationOffset + Size > ConfigSpaceSize) {\r
    return RETURN_UNSUPPORTED;\r
  }\r
  DestinationAddress = PCI_SEGMENT_LIB_ADDRESS (SegmentDev->SegmentNr,\r
                         SegmentDev->BusNr, SegmentDev->DeviceNr,\r
                         SegmentDev->FunctionNr, DestinationOffset);\r
  PciSegmentWriteBuffer (DestinationAddress, Size, SourceBuffer);\r
  return RETURN_SUCCESS;\r
}\r
\r
\r
/**\r
  Create a PCI_CAP_DEV object from the PCI Segment:Bus:Device.Function\r
  quadruplet. The config space accessors are based upon PciSegmentLib.\r
\r
  @param[in] MaxDomain   If MaxDomain is PciCapExtended, then\r
                         PciDevice->ReadConfig() and PciDevice->WriteConfig()\r
                         will delegate extended config space accesses too to\r
                         PciSegmentReadBuffer() and PciSegmentWriteBuffer(),\r
                         respectively. Otherwise, PciDevice->ReadConfig() and\r
                         PciDevice->WriteConfig() will reject accesses to\r
                         extended config space with RETURN_UNSUPPORTED, without\r
                         calling PciSegmentReadBuffer() or\r
                         PciSegmentWriteBuffer(). By setting MaxDomain to\r
                         PciCapNormal, the platform can prevent undefined\r
                         PciSegmentLib behavior when the PCI root bridge under\r
                         the PCI device at Segment:Bus:Device.Function doesn't\r
                         support extended config space.\r
\r
  @param[in] Segment     16-bit wide segment number.\r
\r
  @param[in] Bus         8-bit wide bus number.\r
\r
  @param[in] Device      5-bit wide device number.\r
\r
  @param[in] Function    3-bit wide function number.\r
\r
  @param[out] PciDevice  The PCI_CAP_DEV object constructed as described above.\r
                         PciDevice can be passed to the PciCapLib APIs.\r
\r
  @retval RETURN_SUCCESS            PciDevice has been constructed and output.\r
\r
  @retval RETURN_INVALID_PARAMETER  Device or Function does not fit in the\r
                                    permitted number of bits.\r
\r
  @retval RETURN_OUT_OF_RESOURCES   Memory allocation failed.\r
**/\r
RETURN_STATUS\r
EFIAPI\r
PciCapPciSegmentDeviceInit (\r
  IN  PCI_CAP_DOMAIN MaxDomain,\r
  IN  UINT16         Segment,\r
  IN  UINT8          Bus,\r
  IN  UINT8          Device,\r
  IN  UINT8          Function,\r
  OUT PCI_CAP_DEV    **PciDevice\r
  )\r
{\r
  SEGMENT_DEV *SegmentDev;\r
\r
  if (Device > PCI_MAX_DEVICE || Function > PCI_MAX_FUNC) {\r
    return RETURN_INVALID_PARAMETER;\r
  }\r
\r
  SegmentDev = AllocatePool (sizeof *SegmentDev);\r
  if (SegmentDev == NULL) {\r
    return RETURN_OUT_OF_RESOURCES;\r
  }\r
\r
  SegmentDev->Signature              = SEGMENT_DEV_SIG;\r
  SegmentDev->MaxDomain              = MaxDomain;\r
  SegmentDev->SegmentNr              = Segment;\r
  SegmentDev->BusNr                  = Bus;\r
  SegmentDev->DeviceNr               = Device;\r
  SegmentDev->FunctionNr             = Function;\r
  SegmentDev->BaseDevice.ReadConfig  = SegmentDevReadConfig;\r
  SegmentDev->BaseDevice.WriteConfig = SegmentDevWriteConfig;\r
\r
  *PciDevice = &SegmentDev->BaseDevice;\r
  return RETURN_SUCCESS;\r
}\r
\r
\r
/**\r
  Free the resources used by PciDevice.\r
\r
  @param[in] PciDevice  The PCI_CAP_DEV object to free, originally produced by\r
                        PciCapPciSegmentDeviceInit().\r
**/\r
VOID\r
EFIAPI\r
PciCapPciSegmentDeviceUninit (\r
  IN PCI_CAP_DEV *PciDevice\r
  )\r
{\r
  SEGMENT_DEV *SegmentDev;\r
\r
  SegmentDev = SEGMENT_DEV_FROM_PCI_CAP_DEV (PciDevice);\r
  FreePool (SegmentDev);\r
}\r