audk/OvmfPkg/Include/Library/PciCapPciSegmentLib.h

77 lines
2.6 KiB
C

/** @file
Library class layered on top of PciCapLib that allows clients to plug a
PciSegmentLib backend into PciCapLib, for config space access.
Copyright (C) 2018, Red Hat, Inc.
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#ifndef __PCI_CAP_PCI_SEGMENT_LIB_H__
#define __PCI_CAP_PCI_SEGMENT_LIB_H__
#include <Library/PciCapLib.h>
/**
Create a PCI_CAP_DEV object from the PCI Segment:Bus:Device.Function
quadruplet. The config space accessors are based upon PciSegmentLib.
@param[in] MaxDomain If MaxDomain is PciCapExtended, then
PciDevice->ReadConfig() and PciDevice->WriteConfig()
will delegate extended config space accesses too to
PciSegmentReadBuffer() and PciSegmentWriteBuffer(),
respectively. Otherwise, PciDevice->ReadConfig() and
PciDevice->WriteConfig() will reject accesses to
extended config space with RETURN_UNSUPPORTED, without
calling PciSegmentReadBuffer() or
PciSegmentWriteBuffer(). By setting MaxDomain to
PciCapNormal, the platform can prevent undefined
PciSegmentLib behavior when the PCI root bridge under
the PCI device at Segment:Bus:Device.Function doesn't
support extended config space.
@param[in] Segment 16-bit wide segment number.
@param[in] Bus 8-bit wide bus number.
@param[in] Device 5-bit wide device number.
@param[in] Function 3-bit wide function number.
@param[out] PciDevice The PCI_CAP_DEV object constructed as described above.
PciDevice can be passed to the PciCapLib APIs.
@retval RETURN_SUCCESS PciDevice has been constructed and output.
@retval RETURN_INVALID_PARAMETER Device or Function does not fit in the
permitted number of bits.
@retval RETURN_OUT_OF_RESOURCES Memory allocation failed.
**/
RETURN_STATUS
EFIAPI
PciCapPciSegmentDeviceInit (
IN PCI_CAP_DOMAIN MaxDomain,
IN UINT16 Segment,
IN UINT8 Bus,
IN UINT8 Device,
IN UINT8 Function,
OUT PCI_CAP_DEV **PciDevice
);
/**
Free the resources used by PciDevice.
@param[in] PciDevice The PCI_CAP_DEV object to free, originally produced by
PciCapPciSegmentDeviceInit().
**/
VOID
EFIAPI
PciCapPciSegmentDeviceUninit (
IN PCI_CAP_DEV *PciDevice
);
#endif // __PCI_CAP_PCI_SEGMENT_LIB_H__