[Skiboot] [PATCH v2 7/9] prd: Implement generic HBRT - FSP interface

[Vasant Hegde]

On 05/10/2019 12:35 PM, Jeremy Kerr wrote:
> Hi Vasant,
> 
>>> Why make it conditional? Can't we use the PRD2 interface for small
>>> messages too?
>>
>> .. So that it can work with old kernel as well. Hence I added this
>> check.
> 
> OK, gotchya. So this will indicate failure (to the caller) when the
> kernel cannot dequeue the larger message, is that correct?

Yes.

> 
>>
>>>> +struct prd_fw_mbox_msg {
>>>> +	__be32	msgq;		/* ex: MBOX::FSP_VPD_MSGQ */
>>>> +	__be32	msg_type;	/* ex: VPD_MSG_TYPE:VPD_WRITE_PROC
>>>> */
>>>> +	struct {
>>>> +		__be32	async:1;
>>>> +		__be32	pseudosync:1;
>>>> +		__be32	unused:30;
>>>> +	};
>>>
>>> Are you expecting all compilers to lay these bitfields out in a
>>> consistent format?
>>
>> This is hostboot defined structure. This is directly passed by HBRT to
>> FSP.
>> We are not using it. Just for completeness purpose I have defined this
>> structure.
> 
> The prd-fw-msg.h header was originally intended to contain definitions
> that OPAL needed for implementing the opaque firmware channel (ie,
> firmware_request & firmware_notify). If this structure isn't needed for
> that, I'd rather drop it.

I can drop this structure and just make it as void *mbox_data. Will fix it in 
next version.


> 
> Those things aside:
> 
> Acked-by: Jeremy Kerr <jk at ozlabs.org>

Thanks!

-Vasant