UefiPciCapPciIoLib.c

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#include <Library/MemoryAllocationLib.h>
 
#include "UefiPciCapPciIoLib.h"
 
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;
}
 
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
           );
}
 
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
           );
}
 
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;
}
 
VOID
EFIAPI
PciCapPciIoDeviceUninit (
  IN PCI_CAP_DEV  *PciDevice
  )
{
  PROTO_DEV  *ProtoDev;
 
  ProtoDev = PROTO_DEV_FROM_PCI_CAP_DEV (PciDevice);
  FreePool (ProtoDev);
}