On 05/24/18 10:13, Ard Biesheuvel wrote:
> On 23 May 2018 at 22:21, Laszlo Ersek <[email protected]> wrote:
>> Add a library class, and a UEFI_DRIVER lib instance, that are layered on
>> top of PciCapLib, and allow clients to plug an EFI_PCI_IO_PROTOCOL backend
>> into PciCapLib, for config space access.
>>
>> (Side note:
>>
>
> Again, please retain the below.
Will do.
>> +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 >= BIT2 && (ConfigOffset & (BIT2 - 1)) == 0) {
>
> Ugh. Just use '4' or sizeof(UINT32).
>
>> + Width = EfiPciIoWidthUint32;
>> + Count = Size >> Width;
>> + } else if (Size >= BIT1 && (ConfigOffset & (BIT1 - 1)) == 0) {
>> + Width = EfiPciIoWidthUint16;
>> + Count = 1;
>> + } else {
>> + Width = EfiPciIoWidthUint8;
>> + Count = 1;
>> + }
I used "BITx" and "(BITx - 1)" for consistency, and because they seemed
to convey the idea well (namely, shifting down the alignment).
I'm fine replacing "BIT2" with "4", but then I believe I should also
replace "(BIT2 - 1)" with "3". Similarly, replace "BIT1" with "2", and
"(BIT1 -1)" with 1.
Do you prefer the current code or the decimal constants?
Thanks!
Laszlo
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