Re: [dpdk-dev] [EXT] [PATCH v3] config/arm: split march cfg into arch and features

["Juraj Linkeš" <juraj.linkes@pantheon.tech>]

> -----Original Message-----
> From: Pavan Nikhilesh Bhagavatula <pbhagavatula@marvell.com>
> Sent: Tuesday, July 20, 2021 9:25 AM
> To: Juraj Linkeš <juraj.linkes@pantheon.tech>; thomas@monjalon.net;
> david.marchand@redhat.com; bruce.richardson@intel.com;
> Honnappa.Nagarahalli@arm.com; Ruifeng.Wang@arm.com;
> fengchengwen@huawei.com; ferruh.yigit@intel.com; jerinjacobk@gmail.com;
> Jerin Jacob Kollanukkaran <jerinj@marvell.com>
> Cc: dev@dpdk.org
> Subject: RE: [EXT] [dpdk-dev] [PATCH v3] config/arm: split march cfg into arch
> and features
> 
> >Older compilers may not support all arch versions and all features that
> >the target SoC supports, in which case it's better to figure out the
> >highest arch version and features that the compiler supports.
> >Implement
> >a way to achieve this:
> >1. Find the highest arch version that the compiler supports, keeping in
> >mind the SoC arch version we're building. For example, if the SoC arch
> >version is arm8.2-a, but the compiler only supports arm8.1-a, use
> >arm8.1-a. On the other hand, if the compiler supports arm8.3-a (or
> >higher), use armv8.2-a.
> >2. With the architecture version locked, iterate over SoC features and
> >use all that are supported.
> >
> >In all cases, emit a warning if there's something unsupported by the
> >compiler.
> >
> >Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
> 
> 
> Should we add soc_features to allow individual SoCs to configure additional
> extensions they support?
> As we discussed previously [1] default Neoverse-n2 shouldn’t have crypto
> extension as it's an optional feature[2]. SoCs that are based on n2 can define it
> in soc_features.
> 
> 
> [1] http://patches.dpdk.org/project/dpdk/patch/20210505121423.850-1-
> pbhagavatula@marvell.com/
> [2] https://developer.arm.com/ip-products/processors/neoverse/neoverse-n2

Thanks for reminding me, there seemed to be an agreement between you and Honnappa about this, so I'll add it.