[dpdk-dev] [PATCH v4 1/2] config/arm: split march cfg into arch and features

[Juraj Linkeš]

Resending, since there was an error when sending to Chengwen.

> -----Original Message-----
> From: Juraj Linkeš <juraj.linkes at pantheon.tech>
> Sent: Tuesday, August 17, 2021 12:57 PM
> To: thomas at monjalon.net; david.marchand at redhat.com;
> bruce.richardson at intel.com; Honnappa.Nagarahalli at arm.com;
> Ruifeng.Wang at arm.com; fengchengwen at huawei.com;
> ferruh.yigit at intel.com; jerinjacobk at gmail.com; jerinj at marvell.com;
> pbhagavatula at marvell.com
> Cc: dev at dpdk.org; Juraj Linkeš <juraj.linkes at pantheon.tech>
> Subject: [PATCH v4 1/2] 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 at pantheon.tech>
> ---
> v4: rebase
> ---
>  config/arm/meson.build | 124 ++++++++++++++++++++++++++++++++---------
>  1 file changed, 99 insertions(+), 25 deletions(-)
> 
> diff --git a/config/arm/meson.build b/config/arm/meson.build index
> 14987c634a..c11efa1583 100644
> --- a/config/arm/meson.build
> +++ b/config/arm/meson.build
> @@ -38,7 +38,9 @@ implementer_generic = {
>      ],
>      'part_number_config': {
>          'generic': {
> -            'machine_args': ['-march=armv8-a+crc', '-moutline-atomics']
> +            'march': 'armv8-a',
> +            'march_features': ['crc'],
> +            'compiler_options': ['-moutline-atomics']
>          },
>          'generic_aarch32': {
>              'machine_args': ['-march=armv8-a', '-mfpu=neon'], @@ -53,15 +55,17
> @@ implementer_generic = {  }
> 
>  part_number_config_arm = {
> -    '0xd03': {'machine_args':  ['-mcpu=cortex-a53']},
> -    '0xd04': {'machine_args':  ['-mcpu=cortex-a35']},
> -    '0xd07': {'machine_args':  ['-mcpu=cortex-a57']},
> -    '0xd08': {'machine_args':  ['-mcpu=cortex-a72']},
> -    '0xd09': {'machine_args':  ['-mcpu=cortex-a73']},
> -    '0xd0a': {'machine_args':  ['-mcpu=cortex-a75']},
> -    '0xd0b': {'machine_args':  ['-mcpu=cortex-a76']},
> +    '0xd03': {'compiler_options':  ['-mcpu=cortex-a53']},
> +    '0xd04': {'compiler_options':  ['-mcpu=cortex-a35']},
> +    '0xd07': {'compiler_options':  ['-mcpu=cortex-a57']},
> +    '0xd08': {'compiler_options':  ['-mcpu=cortex-a72']},
> +    '0xd09': {'compiler_options':  ['-mcpu=cortex-a73']},
> +    '0xd0a': {'compiler_options':  ['-mcpu=cortex-a75']},
> +    '0xd0b': {'compiler_options':  ['-mcpu=cortex-a76']},
>      '0xd0c': {
> -        'machine_args':  ['-march=armv8.2-a+crypto', '-mcpu=neoverse-n1'],
> +        'march': 'armv8.2-a',
> +        'march_features': ['crypto'],
> +        'compiler_options':  ['-mcpu=neoverse-n1'],
>          'flags': [
>              ['RTE_MACHINE', '"neoverse-n1"'],
>              ['RTE_ARM_FEATURE_ATOMICS', true], @@ -71,7 +75,8 @@
> part_number_config_arm = {
>          ]
>      },
>      '0xd49': {
> -        'machine_args':  ['-march=armv8.5-a+crypto+sve2'],
> +        'march': 'armv8.5-a',
> +        'march_features': ['crypto', 'sve2'],
>          'flags': [
>              ['RTE_MACHINE', '"neoverse-n2"'],
>              ['RTE_ARM_FEATURE_ATOMICS', true], @@ -105,19 +110,21 @@
> implementer_cavium = {
>      ],
>      'part_number_config': {
>          '0xa1': {
> -            'machine_args': ['-mcpu=thunderxt88'],
> +            'compiler_options': ['-mcpu=thunderxt88'],
>              'flags': flags_part_number_thunderx
>          },
>          '0xa2': {
> -            'machine_args': ['-mcpu=thunderxt81'],
> +            'compiler_options': ['-mcpu=thunderxt81'],
>              'flags': flags_part_number_thunderx
>          },
>          '0xa3': {
> -            'machine_args': ['-mcpu=thunderxt83'],
> +            'compiler_options': ['-mcpu=thunderxt83'],
>              'flags': flags_part_number_thunderx
>          },
>          '0xaf': {
> -            'machine_args': ['-march=armv8.1-a+crc+crypto', '-
> mcpu=thunderx2t99'],
> +            'march': 'armv8.1-a',
> +            'march_features': ['crc', 'crypto'],
> +            'compiler_options': ['-mcpu=thunderx2t99'],
>              'flags': [
>                  ['RTE_MACHINE', '"thunderx2"'],
>                  ['RTE_ARM_FEATURE_ATOMICS', true], @@ -127,7 +134,9 @@
> implementer_cavium = {
>              ]
>          },
>          '0xb2': {
> -            'machine_args': ['-march=armv8.2-a+crc+crypto+lse', '-
> mcpu=octeontx2'],
> +            'march': 'armv8.2-a',
> +            'march_features': ['crc', 'crypto', 'lse'],
> +            'compiler_options': ['-mcpu=octeontx2'],
>              'flags': [
>                  ['RTE_MACHINE', '"octeontx2"'],
>                  ['RTE_ARM_FEATURE_ATOMICS', true], @@ -148,7 +157,11 @@
> implementer_ampere = {
>          ['RTE_MAX_NUMA_NODES', 1]
>      ],
>      'part_number_config': {
> -        '0x0': {'machine_args':  ['-march=armv8-a+crc+crypto', '-mtune=emag']}
> +        '0x0': {
> +            'march': 'armv8-a',
> +            'march_features': ['crc', 'crypto'],
> +            'compiler_options':  ['-mtune=emag']
> +        }
>      }
>  }
> 
> @@ -160,7 +173,9 @@ implementer_hisilicon = {
>      ],
>      'part_number_config': {
>          '0xd01': {
> -            'machine_args': ['-march=armv8.2-a+crypto', '-mtune=tsv110'],
> +            'march': 'armv8.2-a',
> +            'march_features': ['crypto'],
> +            'compiler_options': ['-mtune=tsv110'],
>              'flags': [
>                  ['RTE_MACHINE', '"Kunpeng 920"'],
>                  ['RTE_ARM_FEATURE_ATOMICS', true], @@ -169,7 +184,8 @@
> implementer_hisilicon = {
>              ]
>          },
>          '0xd02': {
> -            'machine_args': ['-march=armv8.2-a+crypto+sve'],
> +            'march': 'armv8.2-a',
> +            'march_features': ['crypto', 'sve'],
>              'flags': [
>                  ['RTE_MACHINE', '"Kunpeng 930"'],
>                  ['RTE_ARM_FEATURE_ATOMICS', true], @@ -190,8 +206,14 @@
> implementer_qualcomm = {
>          ['RTE_MAX_NUMA_NODES', 1]
>      ],
>      'part_number_config': {
> -        '0x800': {'machine_args':  ['-march=armv8-a+crc']},
> -        '0xc00': {'machine_args':  ['-march=armv8-a+crc']},
> +        '0x800': {
> +            'march': 'armv8-a',
> +            'march_features': ['crc']
> +        },
> +        '0xc00': {
> +            'march': 'armv8-a',
> +            'march_features': ['crc']
> +        }
>      }
>  }
> 
> @@ -500,13 +522,65 @@ if update_flags
>      # add/overwrite flags in the proper order
>      dpdk_flags = flags_common + implementer_config['flags'] +
> part_number_config.get('flags', []) + soc_flags
> 
> -    # apply supported machine args
>      machine_args = [] # Clear previous machine args
> -    foreach flag: part_number_config['machine_args']
> -        if cc.has_argument(flag)
> -            machine_args += flag
> +
> +    # probe supported marchs and their features
> +    candidate_march = ''
> +    if part_number_config.has_key('march')
> +        supported_marchs = ['armv8.6-a', 'armv8.5-a', 'armv8.4-a', 'armv8.3-a',
> +                            'armv8.2-a', 'armv8.1-a', 'armv8-a']
> +        check_compiler_support = false
> +        foreach supported_march: supported_marchs
> +            if supported_march == part_number_config['march']
> +                # start checking from this version downwards
> +                check_compiler_support = true
> +            endif
> +            if (check_compiler_support and
> +                cc.has_argument('-march=' + supported_march))
> +                candidate_march = supported_march
> +                # highest supported march version found
> +                break
> +            endif
> +        endforeach
> +        if candidate_march == ''
> +            error('No suitable armv8 march version found.')
>          endif
> -    endforeach
> +        if candidate_march != part_number_config['march']
> +            warning('Configuration march version is ' +
> +                    '@0@, but the compiler supports only @1 at .'
> +                    .format(part_number_config['march'], candidate_march))
> +        endif
> +        candidate_march = '-march=' + candidate_march
> +
> +        march_features = []
> +        if part_number_config.has_key('march_features')
> +            march_features += part_number_config['march_features']
> +        endif
> +        if soc_config.has_key('extra_march_features')
> +            march_features += soc_config['extra_march_features']
> +        endif
> +        foreach feature: march_features
> +            if cc.has_argument('+'.join([candidate_march, feature]))
> +                candidate_march = '+'.join([candidate_march, feature])
> +            else
> +                warning('The compiler does not support feature @0@'
> +                    .format(feature))
> +            endif
> +        endforeach
> +        machine_args += candidate_march
> +    endif
> +
> +    # apply supported compiler options
> +    if part_number_config.has_key('compiler_options')
> +        foreach flag: part_number_config['compiler_options']
> +            if cc.has_argument(flag)
> +                machine_args += flag
> +            else
> +                warning('Configuration compiler option ' +
> +                        '@0@ isn\'t supported.'.format(flag))
> +            endif
> +        endforeach
> +    endif
> 
>      # apply flags
>      foreach flag: dpdk_flags
> --
> 2.20.1