ibmvtpm byteswapping inconsistency
Michael Ellerman
mpe at ellerman.id.au
Tue Jan 31 19:38:32 AEDT 2017
Tyrel Datwyler <tyreld at linux.vnet.ibm.com> writes:
> On 01/29/2017 08:32 PM, Michael Ellerman wrote:
>> Tyrel Datwyler <tyreld at linux.vnet.ibm.com> writes:
>>>
>>> Byte | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7
>>> -----------------------------------------------------------------------
>>> Word0 | Valid | Type | Length | Data
>>> -----------------------------------------------------------------------
>>> Word1 | Reserved
>>> -----------------------------------------------------------------------
>>>
>>> The following definition looks to match:
>>>
>>> struct ibmvtpm_crq {
>>> u8 valid;
>>> u8 msg;
>>> __be16 len;
>>> __be32 data;
>>> __be64 reserved;
>>> } __attribute__((packed, aligned(8)));
>>
>> Well it's a partial match.
>>
>> Your layout above doesn't define which byte of Length or Data is the MSB
>> or LSB. So going by that we still don't know the endianness of either
>
> I should have been explicit that PAPR uses Big Endian bit and byte
> numbering throughout the spec unless otherwise noted.
OK. I didn't actually remember that so yeah good to be explicit.
cheers
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