Re: [dpdk-dev] [PATCH v4 2/6] build: refactor Arm build

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

> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Juraj Linkeš
> Sent: Tuesday, October 27, 2020 9:11 AM
> To: Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>;
> bruce.richardson@intel.com; Ruifeng Wang <Ruifeng.Wang@arm.com>; Phil
> Yang <Phil.Yang@arm.com>; vcchunga@amazon.com; Dharmik Thakkar
> <Dharmik.Thakkar@arm.com>; jerinjacobk@gmail.com;
> hemant.agrawal@nxp.com
> Cc: dev@dpdk.org; nd <nd@arm.com>; nd <nd@arm.com>
> Subject: Re: [dpdk-dev] [PATCH v4 2/6] build: refactor Arm build
> 
> 
> 
> > -----Original Message-----
> > From: Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>
> > Sent: Tuesday, October 27, 2020 5:56 AM
> > To: Juraj Linkeš <juraj.linkes@pantheon.tech>;
> > bruce.richardson@intel.com; Ruifeng Wang <Ruifeng.Wang@arm.com>; Phil
> > Yang <Phil.Yang@arm.com>; vcchunga@amazon.com; Dharmik Thakkar
> > <Dharmik.Thakkar@arm.com>; jerinjacobk@gmail.com;
> > hemant.agrawal@nxp.com
> > Cc: dev@dpdk.org; nd <nd@arm.com>; Honnappa Nagarahalli
> > <Honnappa.Nagarahalli@arm.com>; nd <nd@arm.com>
> > Subject: RE: [PATCH v4 2/6] build: refactor Arm build
> >
> > <snip>
> > I think we need to split this further. Few suggestions below.
> >
> > >
> > > * Rename variables to have names that better describe what the
> > > variables store
> > This should be a separate commit.
> >
> > > * Remove unused or superfluous variables
> > Same here
> >
> > > * Change a list to dictionary where key lookup is needed
> > Same here
> >
> > > * Add informatory comments in the code
> >
> > > * Minor code restructure and reformatting
> > Same for this
> >
> 
> Ok, hopefully I'll be able to separate these cleanly.
> 
> > >
> > > Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > > ---
> > >  config/arm/arm64_armada_linux_gcc    |   2 +-
> > >  config/arm/arm64_armv8_linux_gcc     |   8 +-
> > >  config/arm/arm64_bluefield_linux_gcc |   4 +-
> > >  config/arm/arm64_dpaa_linux_gcc      |   2 +-
> > >  config/arm/arm64_emag_linux_gcc      |   2 +-
> > >  config/arm/arm64_n1sdp_linux_gcc     |   4 +-
> > >  config/arm/arm64_octeontx2_linux_gcc |   4 +-
> > >  config/arm/arm64_stingray_linux_gcc  |   4 +-
> > >  config/arm/arm64_thunderx2_linux_gcc |   4 +-
> > >  config/arm/arm64_thunderx_linux_gcc  |   2 +-
> > >  config/arm/meson.build               | 247 +++++++++++++++------------
> > >  11 files changed, 153 insertions(+), 130 deletions(-)
> > >
> > > diff --git a/config/arm/arm64_armada_linux_gcc
> > > b/config/arm/arm64_armada_linux_gcc
> > > index fa40c0398..52c5f4476 100644
> > > --- a/config/arm/arm64_armada_linux_gcc
> > > +++ b/config/arm/arm64_armada_linux_gcc
> > > @@ -14,4 +14,4 @@ cpu = 'armv8-a'
> > >  endian = 'little'
> > >
> > >  [properties]
> > > -implementor_id = '0x56'
> > > +implementer_id = '0x56'
> > Implementor and implementer mean the same. Looked at Arm specs, they
> > use 'implementer'. So, I am fine.
> >
> 
> That's where I got this and some of the other variable name changes from.
> 
> > > diff --git a/config/arm/arm64_armv8_linux_gcc
> > > b/config/arm/arm64_armv8_linux_gcc
> > > index 88f0ff9da..13ee8b223 100644
> > > --- a/config/arm/arm64_armv8_linux_gcc
> > > +++ b/config/arm/arm64_armv8_linux_gcc
> > > @@ -13,10 +13,10 @@ cpu = 'armv8-a'
> > >  endian = 'little'
> > >
> > >  [properties]
> > > -implementor_id = 'generic'
> > > +implementer_id = 'generic'
> > >
> > > -# Valid options for Arm's implementor_pn:
> > > -# 'default': valid for all armv8-a architectures (default value)
> > > +# Valid options for Arm's part_number:
> > > +# 'generic': valid for all armv8-a architectures (default value)
> > >  # '0xd03':   cortex-a53
> > >  # '0xd04':   cortex-a35
> > >  # '0xd05':   cortex-a55
> > > @@ -25,4 +25,4 @@ implementor_id = 'generic'
> > >  # '0xd09':   cortex-a73
> > >  # '0xd0a':   cortex-a75
> > >  # '0xd0b':   cortex-a76
> > > -implementor_pn = 'default'
> > > +part_number = 'generic'
> > Same here, Arm specs refer to this as 'PartNumber'. So, this should be fine.
> > I like 'generic' for part_number here.
> >
> > > diff --git a/config/arm/arm64_bluefield_linux_gcc
> > > b/config/arm/arm64_bluefield_linux_gcc
> > > index 86797d23c..b79389d85 100644
> > > --- a/config/arm/arm64_bluefield_linux_gcc
> > > +++ b/config/arm/arm64_bluefield_linux_gcc
> > > @@ -13,5 +13,5 @@ cpu = 'armv8-a'
> > >  endian = 'little'
> > >
> > >  [properties]
> > > -implementor_id = '0x41'
> > > -implementor_pn = '0xd08'
> > > +implementer_id = '0x41'
> > > +part_number = '0xd08'
> > > diff --git a/config/arm/arm64_dpaa_linux_gcc
> > > b/config/arm/arm64_dpaa_linux_gcc index 1a4682154..573ae7e42 100644
> > > --- a/config/arm/arm64_dpaa_linux_gcc
> > > +++ b/config/arm/arm64_dpaa_linux_gcc
> > > @@ -14,4 +14,4 @@ cpu = 'armv8-a'
> > >  endian = 'little'
> > >
> > >  [properties]
> > > -implementor_id = 'dpaa'
> > > +implementer_id = 'dpaa'
> > > diff --git a/config/arm/arm64_emag_linux_gcc
> > > b/config/arm/arm64_emag_linux_gcc index 8edcd3e97..24f3d533e 100644
> > > --- a/config/arm/arm64_emag_linux_gcc
> > > +++ b/config/arm/arm64_emag_linux_gcc
> > > @@ -13,4 +13,4 @@ cpu = 'armv8-a'
> > >  endian = 'little'
> > >
> > >  [properties]
> > > -implementor_id = '0x50'
> > > +implementer_id = '0x50'
> > > diff --git a/config/arm/arm64_n1sdp_linux_gcc
> > > b/config/arm/arm64_n1sdp_linux_gcc
> > > index 022e06303..6fb3f02ea 100644
> > > --- a/config/arm/arm64_n1sdp_linux_gcc
> > > +++ b/config/arm/arm64_n1sdp_linux_gcc
> > > @@ -13,5 +13,5 @@ cpu = 'armv8-a'
> > >  endian = 'little'
> > >
> > >  [properties]
> > > -implementor_id = '0x41'
> > > -implementor_pn = '0xd0c'
> > > +implementer_id = '0x41'
> > > +part_number = '0xd0c'
> > > diff --git a/config/arm/arm64_octeontx2_linux_gcc
> > > b/config/arm/arm64_octeontx2_linux_gcc
> > > index 365bd7cbd..ac1042806 100644
> > > --- a/config/arm/arm64_octeontx2_linux_gcc
> > > +++ b/config/arm/arm64_octeontx2_linux_gcc
> > > @@ -13,5 +13,5 @@ cpu = 'armv8-a'
> > >  endian = 'little'
> > >
> > >  [properties]
> > > -implementor_id = '0x43'
> > > -implementor_pn = '0xb2'
> > > +implementer_id = '0x43'
> > > +part_number = '0xb2'
> > > diff --git a/config/arm/arm64_stingray_linux_gcc
> > > b/config/arm/arm64_stingray_linux_gcc
> > > index 86797d23c..b79389d85 100644
> > > --- a/config/arm/arm64_stingray_linux_gcc
> > > +++ b/config/arm/arm64_stingray_linux_gcc
> > > @@ -13,5 +13,5 @@ cpu = 'armv8-a'
> > >  endian = 'little'
> > >
> > >  [properties]
> > > -implementor_id = '0x41'
> > > -implementor_pn = '0xd08'
> > > +implementer_id = '0x41'
> > > +part_number = '0xd08'
> > > diff --git a/config/arm/arm64_thunderx2_linux_gcc
> > > b/config/arm/arm64_thunderx2_linux_gcc
> > > index 2b41acc61..dd257745e 100644
> > > --- a/config/arm/arm64_thunderx2_linux_gcc
> > > +++ b/config/arm/arm64_thunderx2_linux_gcc
> > > @@ -13,5 +13,5 @@ cpu = 'armv8-a'
> > >  endian = 'little'
> > >
> > >  [properties]
> > > -implementor_id = '0x43'
> > > -implementor_pn = '0xaf'
> > > +implementer_id = '0x43'
> > > +part_number = '0xaf'
> > > diff --git a/config/arm/arm64_thunderx_linux_gcc
> > > b/config/arm/arm64_thunderx_linux_gcc
> > > index 6572ab615..670764437 100644
> > > --- a/config/arm/arm64_thunderx_linux_gcc
> > > +++ b/config/arm/arm64_thunderx_linux_gcc
> > > @@ -13,4 +13,4 @@ cpu = 'armv8-a'
> > >  endian = 'little'
> > >
> > >  [properties]
> > > -implementor_id = '0x43'
> > > +implementer_id = '0x43'
> > > diff --git a/config/arm/meson.build b/config/arm/meson.build index
> > > 491842cad..6c31ab167 100644
> > > --- a/config/arm/meson.build
> > > +++ b/config/arm/meson.build
> > > @@ -3,12 +3,12 @@
> > >  # Copyright(c) 2017 Cavium, Inc
> > >  # Copyright(c) 2020 PANTHEON.tech s.r.o.
> > >
> > > -# for checking defines we need to use the correct compiler flags
> > > -march_opt = '-march=@0@'.format(machine)
> > > -
> > > +# set arm_force_native_march if you want to use machine args below
> > > +# instead of discovered values; only works when doing an actual
> > > +native build
> > >  arm_force_native_march = false
> > > -arm_force_generic_march = (machine == 'generic')
> > > +native_machine_args = ['-march=native', '-mtune=native']
> > >
> > > +# common flags to all aarch64 builds, with lowest priority
> > >  flags_common_default = [
> > >  	# Accelarate rte_memcpy. Be sure to run unit test
> > > (memcpy_perf_autotest)
> > >  	# to determine the best threshold in code. Refer to notes in
> > > source file @@ -16,8 +16,9 @@ flags_common_default = [
> > >  	['RTE_ARCH_ARM64_MEMCPY', false],
> > >  	#	['RTE_ARM64_MEMCPY_ALIGNED_THRESHOLD', 2048],
> > >  	#	['RTE_ARM64_MEMCPY_UNALIGNED_THRESHOLD', 512],
> > > -	# Leave below RTE_ARM64_MEMCPY_xxx options commented out,
> > > unless there're
> > > -	# strong reasons.
> > > +
> > > +	# Leave below RTE_ARM64_MEMCPY_xxx options commented out,
> > > +	# unless there are strong reasons.
> > >  	#	['RTE_ARM64_MEMCPY_SKIP_GCC_VER_CHECK', false],
> > >  	#	['RTE_ARM64_MEMCPY_ALIGN_MASK', 0xF],
> > >  	#	['RTE_ARM64_MEMCPY_STRICT_ALIGN', false],
> > > @@ -28,184 +29,206 @@ flags_common_default = [
> > >
> > >  	['RTE_SCHED_VECTOR', false],
> > >  	['RTE_ARM_USE_WFE', false],
> > > +	['RTE_CACHE_LINE_SIZE', 128],
> > > +	['RTE_ARCH_ARM64', true]
> > >  ]
> > >
> > > +# implementer specific aarch64 flags, with middle priority # (will
> > > +overwrite common flags)
> > >  flags_generic = [
> > >  	['RTE_MACHINE', '"armv8a"'],
> > >  	['RTE_MAX_LCORE', 256],
> > >  	['RTE_USE_C11_MEM_MODEL', true],
> > > -	['RTE_CACHE_LINE_SIZE', 128]]
> > > +	['RTE_CACHE_LINE_SIZE', 128]
> > > +]
> > Any particular reason for this change? (and similar changes below)
> >
> 
> The first bracket is split from the second bracket so I did the same for the last
> two brackets. It makes it more apparent which brackets are paired, it's more
> consistent and also in line with how flags_common_default is formatted.
> 
> > >  flags_arm = [
> > >  	['RTE_MACHINE', '"armv8a"'],
> > >  	['RTE_MAX_LCORE', 16],
> > >  	['RTE_USE_C11_MEM_MODEL', true],
> > > -	['RTE_CACHE_LINE_SIZE', 64]]
> > > +	['RTE_CACHE_LINE_SIZE', 64]
> > > +]
> > >  flags_cavium = [
> > >  	['RTE_CACHE_LINE_SIZE', 128],
> > >  	['RTE_MAX_NUMA_NODES', 2],
> > >  	['RTE_MAX_LCORE', 96],
> > > -	['RTE_MAX_VFIO_GROUPS', 128]]
> > > +	['RTE_MAX_VFIO_GROUPS', 128]
> > > +]
> > >  flags_dpaa = [
> > >  	['RTE_MACHINE', '"dpaa"'],
> > >  	['RTE_USE_C11_MEM_MODEL', true],
> > >  	['RTE_CACHE_LINE_SIZE', 64],
> > >  	['RTE_MAX_NUMA_NODES', 1],
> > >  	['RTE_MAX_LCORE', 16],
> > > -	['RTE_LIBRTE_DPAA2_USE_PHYS_IOVA', false]]
> > > +	['RTE_LIBRTE_DPAA2_USE_PHYS_IOVA', false] ]
> > This is not needed
> >
> 
> Do you mean the space? It should be a line break. I'll check the exact characters,
> but I see this as adding a space in my local patch. Or do you mean the config
> option? It's set to true by default in config/meson.build and according to [1] it
> should be disabled.
> 
> [1] http://git.dpdk.org/dpdk/tree/config/defconfig_arm64-dpaa-linuxapp-
> gcc?h=v20.08
> 
> > >  flags_emag = [
> > >  	['RTE_MACHINE', '"emag"'],
> > > -	['RTE_CACHE_LINE_SIZE', 64],
> > >  	['RTE_MAX_NUMA_NODES', 1],
> > > -	['RTE_MAX_LCORE', 32]]
> > > +	['RTE_MAX_LCORE', 32],
> > > +	['RTE_CACHE_LINE_SIZE', 64]
> > > +]
> > >  flags_armada = [
> > >  	['RTE_MACHINE', '"armv8a"'],
> > > -	['RTE_CACHE_LINE_SIZE', 64],
> > >  	['RTE_MAX_NUMA_NODES', 1],
> > > -	['RTE_MAX_LCORE', 16]]
> > > +	['RTE_MAX_LCORE', 16],
> > > +	['RTE_CACHE_LINE_SIZE', 64]
> > > +]
> > Any reason for this change?
> >
> 
> The default (from flags_common_default) is 128 and I found here [0] that it
> should be set to 64 so I added it here. Should this also be in a separate patch
> (apart from those 4 already mention above)?
> 
> [0] http://git.dpdk.org/dpdk/tree/config/defconfig_arm64-armada-linuxapp-
> gcc?h=v20.08
> 

Sorry, I overlooked that I just moved the config around. I don't remember why. I could see that I wanted to make the order consistent across the different flag group, but that is not the case even with these changes. I'll make it consistent when I split the patch.

> > >
> > > -flags_default_extra = []
> > > +# part number specific aarch64 flags, with highest priority # (will
> > > +overwrite both common and implementer specific flags)
> > >  flags_n1sdp_extra = [
> > >  	['RTE_MACHINE', '"n1sdp"'],
> > >  	['RTE_MAX_NUMA_NODES', 1],
> > >  	['RTE_MAX_LCORE', 4],
> > >  	['RTE_EAL_NUMA_AWARE_HUGEPAGES', false],
> > > -	['RTE_LIBRTE_VHOST_NUMA', false]]
> > > +	['RTE_LIBRTE_VHOST_NUMA', false]
> > > +]
> > >  flags_thunderx_extra = [
> > >  	['RTE_MACHINE', '"thunderx"'],
> > > -	['RTE_USE_C11_MEM_MODEL', false]]
> > > +	['RTE_USE_C11_MEM_MODEL', false]
> > > +]
> > >  flags_thunderx2_extra = [
> > >  	['RTE_MACHINE', '"thunderx2"'],
> > >  	['RTE_CACHE_LINE_SIZE', 64],
> > >  	['RTE_MAX_NUMA_NODES', 2],
> > >  	['RTE_MAX_LCORE', 256],
> > >  	['RTE_ARM_FEATURE_ATOMICS', true],
> > > -	['RTE_USE_C11_MEM_MODEL', true]]
> > > +	['RTE_USE_C11_MEM_MODEL', true]
> > > +]
> > >  flags_octeontx2_extra = [
> > >  	['RTE_MACHINE', '"octeontx2"'],
> > >  	['RTE_MAX_NUMA_NODES', 1],
> > >  	['RTE_MAX_LCORE', 36],
> > >  	['RTE_ARM_FEATURE_ATOMICS', true],
> > >  	['RTE_EAL_IGB_UIO', false],
> > > -	['RTE_USE_C11_MEM_MODEL', true]]
> > > -
> > > -machine_args_default = [
> > > -	['default', ['-march=armv8-a+crc', '-moutline-atomics']],
> > > -	['native', ['-march=native']],
> > > -	['0xd03', ['-mcpu=cortex-a53']],
> > > -	['0xd04', ['-mcpu=cortex-a35']],
> > > -	['0xd07', ['-mcpu=cortex-a57']],
> > > -	['0xd08', ['-mcpu=cortex-a72']],
> > > -	['0xd09', ['-mcpu=cortex-a73']],
> > > -	['0xd0a', ['-mcpu=cortex-a75']],
> > > -	['0xd0b', ['-mcpu=cortex-a76']],
> > > -	['0xd0c', ['-march=armv8.2-a+crc+crypto', '-mcpu=neoverse-n1'],
> > > flags_n1sdp_extra]]
> > > -
> > > -machine_args_cavium = [
> > > -	['default', ['-march=armv8-a+crc+crypto','-mcpu=thunderx']],
> > > -	['native', ['-march=native']],
> > > -	['0xa1', ['-mcpu=thunderxt88'], flags_thunderx_extra],
> > > -	['0xa2', ['-mcpu=thunderxt81'], flags_thunderx_extra],
> > > -	['0xa3', ['-mcpu=thunderxt83'], flags_thunderx_extra],
> > > -	['0xaf', ['-march=armv8.1-a+crc+crypto','-mcpu=thunderx2t99'],
> > > flags_thunderx2_extra],
> > > -	['0xb2', ['-march=armv8.2-a+crc+crypto+lse','-mcpu=octeontx2'],
> > > flags_octeontx2_extra]]
> > > -
> > > -machine_args_emag = [
> > > -	['default', ['-march=armv8-a+crc+crypto', '-mtune=emag']],
> > > -	['native', ['-march=native']]]
> > > +	['RTE_USE_C11_MEM_MODEL', true]
> > > +]
> > > +# arm config (implementer 0x41) is the default config
> > > +pn_config_default
> > 'pn' here for 'part_number' is not consistent.
> >
> 
> Ok, I can rename it to part_number_config_default. Same for the other two pn
> variables.
> 
> > > += {
> > > +	'generic': [['-march=armv8-a+crc', '-moutline-atomics']],
> > > +	'0xd03': [['-mcpu=cortex-a53']],
> > > +	'0xd04': [['-mcpu=cortex-a35']],
> > > +	'0xd07': [['-mcpu=cortex-a57']],
> > > +	'0xd08': [['-mcpu=cortex-a72']],
> > > +	'0xd09': [['-mcpu=cortex-a73']],
> > > +	'0xd0a': [['-mcpu=cortex-a75']],
> > > +	'0xd0b': [['-mcpu=cortex-a76']],
> > > +	'0xd0c': [['-march=armv8.2-a+crc+crypto', '-mcpu=neoverse-n1'],
> > > +flags_n1sdp_extra] } pn_config_cavium = {
> > > +	'generic': [['-march=armv8-a+crc+crypto', '-mcpu=thunderx']],
> > > +	'0xa1': [['-mcpu=thunderxt88'], flags_thunderx_extra],
> > > +	'0xa2': [['-mcpu=thunderxt81'], flags_thunderx_extra],
> > > +	'0xa3': [['-mcpu=thunderxt83'], flags_thunderx_extra],
> > > +	'0xaf': [['-march=armv8.1-a+crc+crypto','-mcpu=thunderx2t99'],
> > > flags_thunderx2_extra],
> > > +	'0xb2': [['-march=armv8.2-a+crc+crypto+lse','-mcpu=octeontx2'],
> > > +flags_octeontx2_extra], } pn_config_emag = {
> > > +	'generic': [['-march=armv8-a+crc+crypto', '-mtune=emag']] }
> > >
> > >  ## Arm implementer ID (ARM DDI 0487C.a, Section G7.2.106, Page
> > > G7-5321) -impl_generic = ['Generic armv8', flags_generic,
> > > machine_args_default]
> > > -impl_0x41 = ['Arm', flags_arm, machine_args_default]
> > > -impl_0x42 = ['Broadcom', flags_generic, machine_args_default]
> > > -impl_0x43 = ['Cavium', flags_cavium, machine_args_cavium]
> > > -impl_0x44 = ['DEC', flags_generic, machine_args_default]
> > > -impl_0x49 = ['Infineon', flags_generic, machine_args_default]
> > > -impl_0x4d = ['Motorola', flags_generic, machine_args_default]
> > > -impl_0x4e = ['NVIDIA', flags_generic, machine_args_default]
> > > -impl_0x50 = ['Ampere Computing', flags_emag, machine_args_emag]
> > > -impl_0x51 = ['Qualcomm', flags_generic, machine_args_default]
> > > -impl_0x53 = ['Samsung', flags_generic, machine_args_default]
> > > -impl_0x56 = ['Marvell ARMADA', flags_armada, machine_args_default]
> > > -impl_0x69 = ['Intel', flags_generic, machine_args_default]
> > > -impl_dpaa = ['NXP DPAA', flags_dpaa, machine_args_default]
> > > +impl_generic = ['Generic armv8', flags_generic, pn_config_default]
> > > +impl_0x41 = ['Arm', flags_arm, pn_config_default]
> > > +impl_0x42 = ['Broadcom', flags_generic, pn_config_default]
> > > +impl_0x43 = ['Cavium', flags_cavium, pn_config_cavium]
> > > +impl_0x44 = ['DEC', flags_generic, pn_config_default]
> > > +impl_0x49 = ['Infineon', flags_generic, pn_config_default]
> > > +impl_0x4d = ['Motorola', flags_generic, pn_config_default]
> > > +impl_0x4e = ['NVIDIA', flags_generic, pn_config_default]
> > > +impl_0x50 = ['Ampere Computing', flags_emag, pn_config_emag]
> > > +impl_0x51 = ['Qualcomm', flags_generic, pn_config_default]
> > > +impl_0x53 = ['Samsung', flags_generic, pn_config_default]
> > > +impl_0x56 = ['Marvell ARMADA', flags_armada, pn_config_default]
> > > +impl_0x69 = ['Intel', flags_generic, pn_config_default] impl_dpaa =
> > > +['NXP DPAA', flags_dpaa, pn_config_default]
> > >
> > >  dpdk_conf.set('RTE_ARCH_ARM', 1)
> > >  dpdk_conf.set('RTE_FORCE_INTRINSICS', 1)
> > >
> > >  if dpdk_conf.get('RTE_ARCH_32')
> > > +	# armv7 build
> > >  	dpdk_conf.set('RTE_CACHE_LINE_SIZE', 64)
> > >  	dpdk_conf.set('RTE_ARCH_ARMv7', 1)
> > >  	# the minimum architecture supported, armv7-a, needs the following,
> > >  	# mk/machine/armv7a/rte.vars.mk sets it too
> > >  	machine_args += '-mfpu=neon'
> > >  else
> > > -	dpdk_conf.set('RTE_CACHE_LINE_SIZE', 128)
> > > -	dpdk_conf.set('RTE_ARCH_ARM64', 1)
> > > +	# aarch64 build
> > > +	if not meson.is_cross_build()
> > > +		if machine == 'generic'
> > > +			# default build
> > > +			impl_config = impl_generic
> > > +			part_number = 'generic'
> > > +		else
> > > +			# native build
> > > +			# The script returns ['Implementer', 'Variant',
> > > 'Architecture',
> > > +			# 'Primary Part number', 'Revision']
> > > +			detect_vendor = find_program(join_paths(
> > > +					meson.current_source_dir(),
> > > 'armv8_machine.py'))
> > > +			cmd = run_command(detect_vendor.path())
> > > +			if cmd.returncode() == 0
> > > +				cmd_output =
> > > cmd.stdout().to_lower().strip().split(' ')
> > > +			endif
> > > +			if arm_force_native_march == true
> > > +				part_number = 'native'
> > > +			else
> > > +				part_number = cmd_output[3]
> > > +			endif
> > > +			# Set to generic implementer if implementer is not
> > > found
> > > +			impl_config = get_variable('impl_' + cmd_output[0],
> > > 'impl_generic')
> > > +		endif
> > > +	else
> > > +		# cross build
> > > +		impl_id = meson.get_cross_property('implementer_id',
> > > 'generic')
> > > +		part_number = meson.get_cross_property('part_number',
> > > 'generic')
> > > +		impl_config = get_variable('impl_' + impl_id)
> > > +	endif
> > >
> > > -	machine = []
> > > -	cmd_generic = ['generic', '', '', 'default', '']
> > > -	cmd_output = cmd_generic # Set generic by default
> > > -	machine_args = [] # Clear previous machine args
> > > -	if arm_force_generic_march and not meson.is_cross_build()
> > > -		machine = impl_generic
> > > -		impl_pn = 'default'
> > > +	message('Arm implementer: ' + impl_config[0])
> > > +	message('Arm part number: ' + part_number)
> > > +
> > > +	implementer_flags = impl_config[1]
> > > +	part_number_config = impl_config[2]
> > > +
> > > +	if part_number_config.has_key(part_number)
> > > +		# use the specified part_number machine args if found
> > > +		part_number_config = part_number_config[part_number]
> > > +	elif part_number == 'native'
> > > +		# use native machine args
> > > +		part_number_config = [[native_machine_args]]
> > >  	elif not meson.is_cross_build()
> > > -		# The script returns ['Implementer', 'Variant', 'Architecture',
> > > -		# 'Primary Part number', 'Revision']
> > > -		detect_vendor = find_program(join_paths(
> > > -				meson.current_source_dir(),
> > > 'armv8_machine.py'))
> > > -		cmd = run_command(detect_vendor.path())
> > > -		if cmd.returncode() == 0
> > > -			cmd_output = cmd.stdout().to_lower().strip().split('
> > > ')
> > > -		endif
> > > -		# Set to generic if variable is not found
> > > -		machine = get_variable('impl_' + cmd_output[0], ['generic'])
> > > -		if machine[0] == 'generic'
> > > -			machine = impl_generic
> > > -			cmd_output = cmd_generic
> > > -		endif
> > > -		impl_pn = cmd_output[3]
> > > -		if arm_force_native_march == true
> > > -			impl_pn = 'native'
> > > -		endif
> > > +		# default to generic machine args if part_number is not found
> > > +		# and not forcing native machine args
> > > +		# but don't default in cross-builds; if part_number is specified
> > > +		# incorrectly in a cross-file, it needs to be fixed there
> > > +		part_number_config = part_number_config['generic']
> > >  	else
> > > -		impl_id = meson.get_cross_property('implementor_id',
> > > 'generic')
> > > -		impl_pn = meson.get_cross_property('implementor_pn',
> > > 'default')
> > > -		machine = get_variable('impl_' + impl_id)
> > > +		# cross build and part number is not in part_number_config
> > > +		error('Cross build part number 0@0 not
> > > found.'.format(part_number))
> > >  	endif
> > >
> > > -	# Apply Common Defaults. These settings may be overwritten by
> > > machine
> > > -	# settings later.
> > > -	foreach flag: flags_common_default
> > > -		if flag.length() > 0
> > > -			dpdk_conf.set(flag[0], flag[1])
> > > +	dpdk_flags = flags_common_default + implementer_flags
> > > +
> > > +	if part_number_config.length() > 1
> > > +		dpdk_flags += part_number_config[1]
> > > +	endif
> > > +
> > > +	machine_args = [] # Clear previous machine args
> > > +	foreach flag: part_number_config[0]
> > > +		if cc.has_argument(flag)
> > > +			machine_args += flag
> > >  		endif
> > >  	endforeach
> > >
> > > -	message('Implementer : ' + machine[0])
> > > -	foreach flag: machine[1]
> > > +	foreach flag: dpdk_flags
> > >  		if flag.length() > 0
> > >  			dpdk_conf.set(flag[0], flag[1])
> > >  		endif
> > >  	endforeach
> > > -
> > > -	foreach marg: machine[2]
> > > -		if marg[0] == impl_pn
> > > -			foreach flag: marg[1]
> > > -				if cc.has_argument(flag)
> > > -					machine_args += flag
> > > -				endif
> > > -			endforeach
> > > -			# Apply any extra machine specific flags.
> > > -			foreach flag: marg.get(2, flags_default_extra)
> > > -				if flag.length() > 0
> > > -					dpdk_conf.set(flag[0], flag[1])
> > > -				endif
> > > -			endforeach
> > > -		endif
> > > -	endforeach
> > >  endif
> > > -message(machine_args)
> > > +
> > > +message('Using machine args: @0@'.format(machine_args))
> > >
> > >  if (cc.get_define('__ARM_NEON', args: machine_args) != '' or
> > >      cc.get_define('__aarch64__', args: machine_args) != '')
> > > --
> > > 2.20.1