Re: [dpdk-dev] [PATCH v2 2/3] config: add arm neoverse N1 SDP configuration

[Jerin Jacob <jerinjacobk@gmail.com>]

On Wed, Oct 23, 2019 at 2:37 AM Honnappa Nagarahalli
<Honnappa.Nagarahalli@arm.com> wrote:
>
> > > <snip>
> > >
> > > >
> > > > On Thu, 2019-08-01 at 07:48 +0800, Gavin Hu wrote:
> > > > > Arm N1 SDP is an infrastructure segment development platform based
> > > > > on armv8.2-a Neoverse N1 CPU. For more information, refer to:
> > > > > https://community.arm.com/developer/tools-software/oss-platforms/w
> > > > > /
> > > > > docs/440/neoverse-n1-sdp
> > > > >
> > > > > Signed-off-by: Gavin Hu <gavin.hu@arm.com>
> > > > > Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> > > > > Reviewed-by: Steve Capper <steve.capper@arm.com>
> > > > > ---
> > > > >  config/arm/meson.build                         |  9 ++++++-
> > > > >  config/defconfig_arm64-neoversen1-linux-gcc    |  1 +
> > > > >  config/defconfig_arm64-neoversen1-linuxapp-gcc | 15 ++++++++++++
> > > > >  mk/machine/neoversen1/rte.vars.mk              | 34
> >
> > > >
> > > > > diff --git a/config/defconfig_arm64-neoversen1-linuxapp-gcc
> > > > > b/config/defconfig_arm64-neoversen1-linuxapp-gcc
> > > > > new file mode 100644
> > > > > index 0000000..39b9e1f
> > > > > --- /dev/null
> > > > > +++ b/config/defconfig_arm64-neoversen1-linuxapp-gcc
> > > > > >
> > > > > @@ -0,0 +1,15 @@
> > > > > +# SPDX-License-Identifier: BSD-3-Clause # Copyright(c) 2019 Arm Ltd.
> > > > > +#
> > > > > +
> > > > > +#include "defconfig_arm64-armv8a-linux-gcc"
> > > > > +
> > > > > +CONFIG_RTE_MACHINE="neoversen1"
> > > > This should probably be "n1sdp" as this is the name of the platform
> > > > that matches the below configuration.
> > > A clear definition of RTE_MACHINE is required. Jerin?
> >
> > I think, In the existing scheme of things, RTE_MACHINE defines, where to take
> > the MACHINE_CFLAGS mk/machine/xxxx/rte.vars.mk
> Ok, thank you
>
> >
> > Considering the fact that there will be a lot of reusable IPs(for CPU) from ARM
> > for  armv8, I think, it would make sense to introduce  RTE_MICRO_ARCH to
> > avoid a lot of code duplications and confusion.
> >
> > RTE_ARCH                             example: "x86" or "arm64"
> > RTE_MICRO_ARCH               example: "a72" or "thunderx3" - defines
> > mcpu and armv8 verion arch etc
> > RTE_MACHINE                       example: "bluefield" or "thunderx3"
> > - defines, number of cores, NUMA or not? etc
> Looking at mk/machine/ directory, looks like RTE_MACHINE seems to be defining micro-architecture for Intel. For ex: hsw, nhm, wsm. I see the same for Arm as well.
> Are you suggesting that we use RTE_MICRO_ARCH to pick mk/micro-arch/xxxx/rte.vars.mk? and RTE_MACHINE would pick mk/machine/xxxx/rte.vars.mk, but contain NUMA, #of cores etc?

Yes for Make build. I think, it is deprecated soon, so we need a
similar solution for meson.

>
> >
> > RTE_MACHINE should be probe based  on "implementation ID" for arm64 and
> > reuse already defined RTE_MICRO_ARCH to avoid code duplication.
> >
> >
> > >
> > > >
> > > > > +CONFIG_RTE_ARCH_ARM_TUNE="neoverse-n1"
> > > > > +CONFIG_RTE_MAX_LCORE=4
> > > > > +CONFIG_RTE_MAX_NUMA_NODES=1
> > > > > +CONFIG_RTE_CACHE_LINE_SIZE=64
> > > > > +
> > > > > +# Doesn't support NUMA
> > > > > +CONFIG_RTE_EAL_NUMA_AWARE_HUGEPAGES=n
> > > > > +CONFIG_RTE_LIBRTE_VHOST_NUMA=n
> > > > > diff --git a/mk/machine/neoversen1/rte.vars.mk
> > > > > b/mk/machine/neoversen1/rte.vars.mk
> > > > > new file mode 100644
> > > > > index 0000000..6d69de0
> > > > > --- /dev/null
> > > > > +++ b/mk/machine/neoversen1/rte.vars.mk
> > > > > @@ -0,0 +1,34 @@
> > > > > +# SPDX-License-Identifier: BSD-3-Clause # Copyright(c) 2019 Arm
> > > > > +Ltd #
> > > > > +
> > > > > +#
> > > > > +# machine:
> > > > > +#
> > > > > +#   - can define ARCH variable (overridden by cmdline value)
> > > > > +#   - can define CROSS variable (overridden by cmdline value)
> > > > > +#   - define MACHINE_CFLAGS variable (overridden by cmdline value)
> > > > > +#   - define MACHINE_LDFLAGS variable (overridden by cmdline value)
> > > > > +#   - define MACHINE_ASFLAGS variable (overridden by cmdline value)
> > > > > +#   - can define CPU_CFLAGS variable (overridden by cmdline value) that
> > > > > +#     overrides the one defined in arch.
> > > > > +#   - can define CPU_LDFLAGS variable (overridden by cmdline value) that
> > > > > +#     overrides the one defined in arch.
> > > > > +#   - can define CPU_ASFLAGS variable (overridden by cmdline value) that
> > > > > +#     overrides the one defined in arch.
> > > > > +#   - may override any previously defined variable
> > > > > +#
> > > > > +
> > > > > +# ARCH =
> > > > > +# CROSS =
> > > > > +# MACHINE_CFLAGS =
> > > > > +# MACHINE_LDFLAGS =
> > > > > +# MACHINE_ASFLAGS =
> > > > > +# CPU_CFLAGS =
> > > > > +# CPU_LDFLAGS =
> > > > > +# CPU_ASFLAGS =
> > > > > +
> > > > > +include $(RTE_SDK)/mk/rte.helper.mk
> > > > > +
> > > > > +MACHINE_CFLAGS += $(call rte_cc_has_argument,
> > > > > +-march=armv8.2-a+crc+crypto) MACHINE_CFLAGS += $(call
> > > > > +rte_cc_has_argument, -mcpu=neoverse-n1)
> > > > >
> > > > >
> > > > --
> > > > Ola Liljedahl, Networking System Architect, Arm Phone +46706866373,
> > > > Skype ola.liljedahl
> > >