[dpdk-dev] [PATCH 2/2] pipeline: autodetect endianness of action args

Ali Alnubani alialnu at nvidia.com
Wed Apr 21 09:49:39 CEST 2021


Hi,

> -----Original Message-----
> From: dev <dev-bounces at dpdk.org> On Behalf Of Thomas Monjalon
> Sent: Tuesday, April 20, 2021 10:58 PM
> To: Cristian Dumitrescu <cristian.dumitrescu at intel.com>
> Cc: dev at dpdk.org
> Subject: Re: [dpdk-dev] [PATCH 2/2] pipeline: autodetect endianness of
> action args
> 
> 12/04/2021 01:23, Cristian Dumitrescu:
> > Each table entry is made up of match fields and action data, with the
> > latter made up of the action ID and the action arguments. The approach
> > of having the user specify explicitly the endianness of the action
> > arguments is difficult to be picked up by P4 compilers, as the P4
> > compiler is generally unaware about this aspect.
> >
> > This commit introduces the auto-detection of the endianness of the
> > action arguments by examining the endianness of the their destination:
> > network byte order (NBO) when they get copied to headers and host byte
> > order (HBO) when they get copied to packet meta-data or mailboxes.
> >
> > The endianness specification of each action argument as part of the
> > rule specification, e.g. H(...) and N(...) is removed from the rule
> > file and auto-detected based on their destination. The DMA instruction
> > scope is made internal, so mov instructions need to be used. The
> > pattern of transferring complete headers from table entry action args
> > to headers is detected, and the associated set of mov instructions
> > plus header validate is internally detected and replaced with the
> > internal-only DMA instruction to preserve performance.
> >
> > Signed-off-by: Cristian Dumitrescu <cristian.dumitrescu at intel.com>
> 
> Series applied, thanks
> 
> 

I believe this patchset is causing the build failures in https://bugs.dpdk.org/show_bug.cgi?id=683.

Regards,
Ali


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