OvmfPkg/Include/Library/PciCapPciSegmentLib.h

   1 /** @file
   2   Library class layered on top of PciCapLib that allows clients to plug a
   3   PciSegmentLib backend into PciCapLib, for config space access.
   4
   5   Copyright (C) 2018, Red Hat, Inc.
   6
   7   This program and the accompanying materials are licensed and made available
   8   under the terms and conditions of the BSD License which accompanies this
   9   distribution.  The full text of the license may be found at
  10   http://opensource.org/licenses/bsd-license.php
  11
  12   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
  13   WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  14 **/
  15
  16 #ifndef __PCI_CAP_PCI_SEGMENT_LIB_H__
  17 #define __PCI_CAP_PCI_SEGMENT_LIB_H__
  18
  19 #include <Library/PciCapLib.h>
  20
  21
  22 /**
  23   Create a PCI_CAP_DEV object from the PCI Segment:Bus:Device.Function
  24   quadruplet. The config space accessors are based upon PciSegmentLib.
  25
  26   @param[in] MaxDomain   If MaxDomain is PciCapExtended, then
  27                          PciDevice->ReadConfig() and PciDevice->WriteConfig()
  28                          will delegate extended config space accesses too to
  29                          PciSegmentReadBuffer() and PciSegmentWriteBuffer(),
  30                          respectively. Otherwise, PciDevice->ReadConfig() and
  31                          PciDevice->WriteConfig() will reject accesses to
  32                          extended config space with RETURN_UNSUPPORTED, without
  33                          calling PciSegmentReadBuffer() or
  34                          PciSegmentWriteBuffer(). By setting MaxDomain to
  35                          PciCapNormal, the platform can prevent undefined
  36                          PciSegmentLib behavior when the PCI root bridge under
  37                          the PCI device at Segment:Bus:Device.Function doesn't
  38                          support extended config space.
  39
  40   @param[in] Segment     16-bit wide segment number.
  41
  42   @param[in] Bus         8-bit wide bus number.
  43
  44   @param[in] Device      5-bit wide device number.
  45
  46   @param[in] Function    3-bit wide function number.
  47
  48   @param[out] PciDevice  The PCI_CAP_DEV object constructed as described above.
  49                          PciDevice can be passed to the PciCapLib APIs.
  50
  51   @retval RETURN_SUCCESS            PciDevice has been constructed and output.
  52
  53   @retval RETURN_INVALID_PARAMETER  Device or Function does not fit in the
  54                                     permitted number of bits.
  55
  56   @retval RETURN_OUT_OF_RESOURCES   Memory allocation failed.
  57 **/
  58 RETURN_STATUS
  59 EFIAPI
  60 PciCapPciSegmentDeviceInit (
  61   IN  PCI_CAP_DOMAIN MaxDomain,
  62   IN  UINT16         Segment,
  63   IN  UINT8          Bus,
  64   IN  UINT8          Device,
  65   IN  UINT8          Function,
  66   OUT PCI_CAP_DEV    **PciDevice
  67   );
  68
  69
  70 /**
  71   Free the resources used by PciDevice.
  72
  73   @param[in] PciDevice  The PCI_CAP_DEV object to free, originally produced by
  74                         PciCapPciSegmentDeviceInit().
  75 **/
  76 VOID
  77 EFIAPI
  78 PciCapPciSegmentDeviceUninit (
  79   IN PCI_CAP_DEV *PciDevice
  80   );
  81
  82 #endif // __PCI_CAP_PCI_SEGMENT_LIB_H__