[dpdk-dev] [EXT] [PATCH v3] config/arm: split march cfg into arch and features

Pavan Nikhilesh Bhagavatula pbhagavatula at marvell.com
Tue Jul 20 09:25:14 CEST 2021


>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>


Should we add soc_features to allow individual SoCs to configure additional extensions 
they support?
As we discussed previously [1] default Neoverse-n2 shouldn’t have crypto extension as
it's an optional feature[2]. SoCs that are based on n2 can define it in soc_features.


[1] http://patches.dpdk.org/project/dpdk/patch/20210505121423.850-1-pbhagavatula@marvell.com/
[2] https://developer.arm.com/ip-products/processors/neoverse/neoverse-n2


>---
>v3: rebase
>---
> config/arm/meson.build | 125
>++++++++++++++++++++++++++++++++---------
> 1 file changed, 100 insertions(+), 25 deletions(-)
>
>diff --git a/config/arm/meson.build b/config/arm/meson.build
>index 14987c634a..f5cd30f4f0 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 +522,66 @@ 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.')
>+        else
>+            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
>         endif
>-    endforeach
>+        if part_number_config.has_key('march_features')
>+            feature_unsupported = false
>+            foreach feature: part_number_config['march_features']
>+                if cc.has_argument('+'.join([candidate_march, feature]))
>+                    candidate_march = '+'.join([candidate_march, feature])
>+                else
>+                    feature_unsupported = true
>+                endif
>+            endforeach
>+            if feature_unsupported
>+                warning('Configuration march features are ' +
>+                        '@0@, but the compiler supports only @1 at .'
>+                        .format(part_number_config['march_features'],
>+                                candidate_march))
>+            endif
>+        endif
>+        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



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