audk/OvmfPkg/Library/UefiPciCapPciIoLib/UefiPciCapPciIoLib.c

238 lines
7.6 KiB
C

/** @file
Plug an EFI_PCI_IO_PROTOCOL backend into PciCapLib, for config space access.
Copyright (C) 2018, Red Hat, Inc.
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <Library/MemoryAllocationLib.h>
#include "UefiPciCapPciIoLib.h"
/**
Transfer bytes between the config space of a given PCI device and a memory
buffer.
ProtoDevTransferConfig() performs as few config space accesses as possible
(without attempting 64-bit wide accesses).
@param[in] PciIo The EFI_PCI_IO_PROTOCOL representation of the
PCI device.
@param[in] TransferFunction The EFI_PCI_IO_PROTOCOL_CONFIG function that
implements the transfer. The direction of the
transfer is inherent to TransferFunction.
TransferFunction() is required to return an
unspecified error if any sub-transfer within
Size bytes from ConfigOffset exceeds the config
space limit of the PCI device.
@param[in] ConfigOffset The offset in the config space of the PCI device
at which the transfer should commence.
@param[in,out] Buffer The memory buffer where the transfer should
occur.
@param[in] Size The number of bytes to transfer.
@retval EFI_SUCCESS Size bytes have been transferred between config space
and Buffer.
@return Error codes propagated from TransferFunction(). Fewer
than Size bytes may have been transferred.
**/
STATIC
EFI_STATUS
ProtoDevTransferConfig (
IN EFI_PCI_IO_PROTOCOL *PciIo,
IN EFI_PCI_IO_PROTOCOL_CONFIG TransferFunction,
IN UINT16 ConfigOffset,
IN OUT UINT8 *Buffer,
IN UINT16 Size
)
{
while (Size > 0) {
EFI_PCI_IO_PROTOCOL_WIDTH Width;
UINT16 Count;
EFI_STATUS Status;
UINT16 Progress;
//
// Pick the largest access size that is allowed by the remaining transfer
// Size and by the alignment of ConfigOffset.
//
// When the largest access size is available, transfer as many bytes as
// possible in one iteration of the loop. Otherwise, transfer only one
// unit, to improve the alignment.
//
if (Size >= 4 && (ConfigOffset & 3) == 0) {
Width = EfiPciIoWidthUint32;
Count = Size >> Width;
} else if (Size >= 2 && (ConfigOffset & 1) == 0) {
Width = EfiPciIoWidthUint16;
Count = 1;
} else {
Width = EfiPciIoWidthUint8;
Count = 1;
}
Status = TransferFunction (PciIo, Width, ConfigOffset, Count, Buffer);
if (EFI_ERROR (Status)) {
return Status;
}
Progress = Count << Width;
ConfigOffset += Progress;
Buffer += Progress;
Size -= Progress;
}
return EFI_SUCCESS;
}
/**
Read the config space of a given PCI device (both normal and extended).
ProtoDevReadConfig() performs as few config space accesses as possible
(without attempting 64-bit wide accesses).
ProtoDevReadConfig() returns an unspecified error if accessing Size bytes
from SourceOffset exceeds the config space limit of the PCI device. Fewer
than Size bytes may have been read in this case.
@param[in] PciDevice Implementation-specific unique representation
of the PCI device in the PCI hierarchy.
@param[in] SourceOffset Source offset in the config space of the PCI
device to start reading from.
@param[out] DestinationBuffer Buffer to store the read data to.
@param[in] Size The number of bytes to transfer.
@retval RETURN_SUCCESS Size bytes have been transferred from config space to
DestinationBuffer.
@return Error codes propagated from
EFI_PCI_IO_PROTOCOL.Pci.Read(). Fewer than Size bytes
may have been read.
**/
STATIC
RETURN_STATUS
EFIAPI
ProtoDevReadConfig (
IN PCI_CAP_DEV *PciDevice,
IN UINT16 SourceOffset,
OUT VOID *DestinationBuffer,
IN UINT16 Size
)
{
PROTO_DEV *ProtoDev;
ProtoDev = PROTO_DEV_FROM_PCI_CAP_DEV (PciDevice);
return ProtoDevTransferConfig (ProtoDev->PciIo, ProtoDev->PciIo->Pci.Read,
SourceOffset, DestinationBuffer, Size);
}
/**
Write the config space of a given PCI device (both normal and extended).
ProtoDevWriteConfig() performs as few config space accesses as possible
(without attempting 64-bit wide accesses).
ProtoDevWriteConfig() returns an unspecified error if accessing Size bytes at
DestinationOffset exceeds the config space limit of the PCI device. Fewer
than Size bytes may have been written in this case.
@param[in] PciDevice Implementation-specific unique representation
of the PCI device in the PCI hierarchy.
@param[in] DestinationOffset Destination offset in the config space of the
PCI device to start writing at.
@param[in] SourceBuffer Buffer to read the data to be stored from.
@param[in] Size The number of bytes to transfer.
@retval RETURN_SUCCESS Size bytes have been transferred from SourceBuffer to
config space.
@return Error codes propagated from
EFI_PCI_IO_PROTOCOL.Pci.Write(). Fewer than Size
bytes may have been written.
**/
STATIC
RETURN_STATUS
EFIAPI
ProtoDevWriteConfig (
IN PCI_CAP_DEV *PciDevice,
IN UINT16 DestinationOffset,
IN VOID *SourceBuffer,
IN UINT16 Size
)
{
PROTO_DEV *ProtoDev;
ProtoDev = PROTO_DEV_FROM_PCI_CAP_DEV (PciDevice);
return ProtoDevTransferConfig (ProtoDev->PciIo, ProtoDev->PciIo->Pci.Write,
DestinationOffset, SourceBuffer, Size);
}
/**
Create a PCI_CAP_DEV object from an EFI_PCI_IO_PROTOCOL instance. The config
space accessors are based upon EFI_PCI_IO_PROTOCOL.Pci.Read() and
EFI_PCI_IO_PROTOCOL.Pci.Write().
@param[in] PciIo EFI_PCI_IO_PROTOCOL representation of the PCI device.
@param[out] PciDevice The PCI_CAP_DEV object constructed as described above.
PciDevice can be passed to the PciCapLib APIs.
@retval EFI_SUCCESS PciDevice has been constructed and output.
@retval EFI_OUT_OF_RESOURCES Memory allocation failed.
**/
EFI_STATUS
EFIAPI
PciCapPciIoDeviceInit (
IN EFI_PCI_IO_PROTOCOL *PciIo,
OUT PCI_CAP_DEV **PciDevice
)
{
PROTO_DEV *ProtoDev;
ProtoDev = AllocatePool (sizeof *ProtoDev);
if (ProtoDev == NULL) {
return EFI_OUT_OF_RESOURCES;
}
ProtoDev->Signature = PROTO_DEV_SIG;
ProtoDev->PciIo = PciIo;
ProtoDev->BaseDevice.ReadConfig = ProtoDevReadConfig;
ProtoDev->BaseDevice.WriteConfig = ProtoDevWriteConfig;
*PciDevice = &ProtoDev->BaseDevice;
return EFI_SUCCESS;
}
/**
Free the resources used by PciDevice.
@param[in] PciDevice The PCI_CAP_DEV object to free, originally produced by
PciCapPciIoDeviceInit().
**/
VOID
EFIAPI
PciCapPciIoDeviceUninit (
IN PCI_CAP_DEV *PciDevice
)
{
PROTO_DEV *ProtoDev;
ProtoDev = PROTO_DEV_FROM_PCI_CAP_DEV (PciDevice);
FreePool (ProtoDev);
}