RE: [RFC PATCH] drivers: add generic build of SVE files

[Wathsala Wathawana Vithanage <wathsala.vithanage@arm.com>]

> -----Original Message-----
> From: David Marchand <david.marchand@redhat.com>
> Sent: Monday, April 7, 2025 10:50 AM
> To: Bruce Richardson <bruce.richardson@intel.com>
> Cc: dev@dpdk.org; Jie Hai <haijie1@huawei.com>
> Subject: Re: [RFC PATCH] drivers: add generic build of SVE files
> 
> On Mon, Apr 7, 2025 at 5:29 PM Bruce Richardson
> <bruce.richardson@intel.com> wrote:
> >
> > For SVE, as for AVX2 and AVX-512, support building files for these
> > ISAs from the top-level drivers/meson.build file, rather than having
> > each driver re-implement it.
> >
> > This removes the remaining build task for drivers in DPDK which is
> > being done by a driver itself, rather than in the generic drivers'
> > build rules.
> >
> > Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
> 
> Thanks for working on this additional cleanup.
> 
> 
> > ---
> >  drivers/meson.build          | 27 +++++++++++++++++++++++++++
> >  drivers/net/hns3/meson.build | 22 +---------------------
> >  2 files changed, 28 insertions(+), 21 deletions(-)
> >
> > diff --git a/drivers/meson.build b/drivers/meson.build index
> > b2d2537dc8..a6f0670a2f 100644
> > --- a/drivers/meson.build
> > +++ b/drivers/meson.build
> > @@ -128,6 +128,7 @@ foreach subpath:subdirs
> >          sources = []
> >          sources_avx2 = []
> >          sources_avx512 = []
> > +        sources_sve = []
> >          headers = []
> >          driver_sdk_headers = [] # public headers included by drivers
> >          objs = []
> > @@ -285,6 +286,32 @@ foreach subpath:subdirs
> >              endif
> >          endif
> >
> > +        if (arch_subdir == 'arm' and sources_sve.length() > 0
> > +                and cc.has_argument('-march=armv8.2-a+sve')
> > +                and cc.check_header('arm_sve.h'))
> > +
> > +            if dpdk_conf.has('RTE_HAS_SVE_ACLE')
> > +                sources += sources_sve
> 
> Do we need this special case?
> 
config/meson.build sets 'RTE_CPUFLAG_SVE for all SoCs with SVE support.
For such SoCs RTE_HAS_SVE_ACLE is set to true if SVE ACLE is available.
However,  for some reason soc_cn10k sets RTE_HAS_SVE_ACLE to false even
though SVE is available on that cnxk SoC.

--wathsala