[dpdk-dev] [RFC PATCH v3 2/6] build: refactor Arm build

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

* Rename variables to have names that better describe what the variables
store
* Remove unused or superfluous variables
* Change a list to dictionary where key lookup is needed
* Add informatory comments in the code
* Minor code restructure and reformatting

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'
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'
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 c88e34a2b..66b08bfb5 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 == 'default' or machine == 'generic-armv8')
+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]
+]
 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]
+]
 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]
+]
 
-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 = {
+	'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 == 'default' or machine == 'generic-armv8'
+			# 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