Re: [PATCH v3 5/5] config/arm: add AMD CDX

[Thomas Monjalon <thomas@monjalon.net>]

08/05/2023 12:24, Gupta, Nipun:
> From: Yigit, Ferruh <Ferruh.Yigit@amd.com>
> > On 4/21/2023 3:54 PM, Nipun Gupta wrote:
> > > Adding support for AMD CDX devices
> > >
> > > Signed-off-by: Nipun Gupta <nipun.gupta@amd.com>
> > > ---
> > >  config/arm/arm64_cdx_linux_gcc | 17 +++++++++++++++++
> > >  config/arm/meson.build         | 14 ++++++++++++++
> > >  2 files changed, 31 insertions(+)
> > >  create mode 100644 config/arm/arm64_cdx_linux_gcc
> > >
> > > diff --git a/config/arm/arm64_cdx_linux_gcc
> > b/config/arm/arm64_cdx_linux_gcc
> > > new file mode 100644
> > > index 0000000000..8e6d619dae
> > > --- /dev/null
> > > +++ b/config/arm/arm64_cdx_linux_gcc
> > > @@ -0,0 +1,17 @@
> > > +[binaries]
> > > +c = ['ccache', 'aarch64-linux-gnu-gcc']
> > > +cpp = ['ccache', 'aarch64-linux-gnu-g++']
> > > +ar = 'aarch64-linux-gnu-ar'
> > > +as = 'aarch64-linux-gnu-as'
> > > +strip = 'aarch64-linux-gnu-strip'
> > > +pkgconfig = 'aarch64-linux-gnu-pkg-config'
> > > +pcap-config = ''
> > > +
> > > +[host_machine]
> > > +system = 'linux'
> > > +cpu_family = 'aarch64'
> > > +cpu = 'armv8-a'
> > > +endian = 'little'
> > > +
> > > +[properties]
> > > +platform = 'cdx'
> > > diff --git a/config/arm/meson.build b/config/arm/meson.build
> > > index 5213434ca4..39b8929534 100644
> > > --- a/config/arm/meson.build
> > > +++ b/config/arm/meson.build
> > > @@ -305,6 +305,18 @@ soc_bluefield = {
> > >      'numa': false
> > >  }
> > >
> > > +soc_cdx = {
> > > +    'description': 'AMD CDX',
> > > +    'implementer': '0x41',
> > > +    'part_number': '0xd42',
> > > +    'flags': [
> > > +        ['RTE_MACHINE', '"cdx"'],
> > > +        ['RTE_MAX_LCORE', 16],
> > > +        ['RTE_MAX_NUMA_NODES', 1]
> > > +    ],
> > > +    'numa': false
> > > +}
> > 
> > Hi Nipun,
> > 
> > Why we need a new arm platform/config? Is it because of above flags?
> > If it can work with default values, I think we can drop this patch.
> 
> Hi Ferruh,
> 
> CDX driver works with generic ARM compilation too (arm64_armv8_linux_gcc).
> 
> The versal platforms supporting CDX have A78 cores, and adding this cdx config
> Helps to provide gcc option "march= armv8.4-a" which is for implementer
> "0xd42" (ARM cortex A78 cores)., whereas for generic ARM compilation
> "march= armv8-a".
> 
> Maybe ARM guys can provide more information regarding if there is any impact
> on using generic architecture flag (i.e. march= armv8a) on A78 cores.

Please let's skip this patch for now.
You should send it separately later, with perf testing and HW description in the commit log.