[dpdk-dev] [RFC PATCH 1/2] build: rework Arm build options

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

The current system can identify only the implementer and part number
of the arm device we're targeting, which is enough to identify the
target CPU. However, even the full MIDR information is not enough to
identify the SoC we're targeting.

Expand the "machine" meson variable to allow specifying the target arm
SoC. The SoC identification implies the CPU, so drop the current MIDR
based CPU identification in favor of user input, which is the only way
to identify the target SoC. This implies that native builds are not
possible. Instead do a default (non-optimized, but executable on any
aarch64 device) build.

Also use the machine custom property in cross files for cross builds.

An example of where the current system is insufficient is the cortex-a72
CPU. These cores are used in a variety of SoC from Broadcomm, NXP,
Huawei and others. The MIDR information would only identify the core,
but there's not way to identify the SoC to fine tune the build to it.

Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
---
 config/arm/arm64_armv8_linux_gcc              |  28 ----
 config/arm/default/arm64_armv8_linux_gcc      |  23 +++
 config/arm/default/meson.build                |   8 +
 config/arm/meson.build                        | 139 +++++++++++-------
 .../{ => thunderx}/arm64_thunderx_linux_gcc   |   2 +-
 config/arm/thunderx/meson.build               |  18 +++
 .../thunderxt88/arm64_thunderxt88_linux_gcc   |  16 ++
 config/arm/thunderxt88/meson.build            |  18 +++
 config/meson.build                            |   9 +-
 9 files changed, 177 insertions(+), 84 deletions(-)
 delete mode 100644 config/arm/arm64_armv8_linux_gcc
 create mode 100644 config/arm/default/arm64_armv8_linux_gcc
 create mode 100644 config/arm/default/meson.build
 rename config/arm/{ => thunderx}/arm64_thunderx_linux_gcc (92%)
 create mode 100644 config/arm/thunderx/meson.build
 create mode 100644 config/arm/thunderxt88/arm64_thunderxt88_linux_gcc
 create mode 100644 config/arm/thunderxt88/meson.build

diff --git a/config/arm/arm64_armv8_linux_gcc b/config/arm/arm64_armv8_linux_gcc
deleted file mode 100644
index 88f0ff9da..000000000
--- a/config/arm/arm64_armv8_linux_gcc
+++ /dev/null
@@ -1,28 +0,0 @@
-[binaries]
-c = 'aarch64-linux-gnu-gcc'
-cpp = 'aarch64-linux-gnu-cpp'
-ar = 'aarch64-linux-gnu-gcc-ar'
-strip = 'aarch64-linux-gnu-strip'
-pkgconfig = 'aarch64-linux-gnu-pkg-config'
-pcap-config = ''
-
-[host_machine]
-system = 'linux'
-cpu_family = 'aarch64'
-cpu = 'armv8-a'
-endian = 'little'
-
-[properties]
-implementor_id = 'generic'
-
-# Valid options for Arm's implementor_pn:
-# 'default': valid for all armv8-a architectures (default value)
-# '0xd03':   cortex-a53
-# '0xd04':   cortex-a35
-# '0xd05':   cortex-a55
-# '0xd07':   cortex-a57
-# '0xd08':   cortex-a72
-# '0xd09':   cortex-a73
-# '0xd0a':   cortex-a75
-# '0xd0b':   cortex-a76
-implementor_pn = 'default'
diff --git a/config/arm/default/arm64_armv8_linux_gcc b/config/arm/default/arm64_armv8_linux_gcc
new file mode 100644
index 000000000..56efd7a05
--- /dev/null
+++ b/config/arm/default/arm64_armv8_linux_gcc
@@ -0,0 +1,23 @@
+[binaries]
+c = 'aarch64-linux-gnu-gcc'
+cpp = 'aarch64-linux-gnu-cpp'
+ar = 'aarch64-linux-gnu-gcc-ar'
+strip = 'aarch64-linux-gnu-strip'
+pkgconfig = 'aarch64-linux-gnu-pkg-config'
+pcap-config = ''
+
+[host_machine]
+system = 'linux'
+cpu_family = 'aarch64'
+cpu = 'armv8-a'
+endian = 'little'
+
+[properties]
+# Valid values for the machine property are the soc names identified by
+# directories in config/arm
+# Possible suffixes for socs:
+# -mn-kc
+# where m is the number of numa nodes and k is the number of lcores
+# e.g. for thunderx soc the possible values are "thunderx" or "thunderx-1n-48c"
+# the suffixes themselves need to be supported in config/arm/<soc_dir>/meson.build
+machine = 'default'
diff --git a/config/arm/default/meson.build b/config/arm/default/meson.build
new file mode 100644
index 000000000..5714d0084
--- /dev/null
+++ b/config/arm/default/meson.build
@@ -0,0 +1,8 @@
+flags = [
+	['RTE_MACHINE', '"armv8a"'],
+	['RTE_MAX_LCORE', 256],
+	['RTE_USE_C11_MEM_MODEL', true],
+	['RTE_CACHE_LINE_SIZE', 128]
+]
+
+machine_args = ['-march=armv8-a+crc']
diff --git a/config/arm/meson.build b/config/arm/meson.build
index 8728051d5..05b790f40 100644
--- a/config/arm/meson.build
+++ b/config/arm/meson.build
@@ -2,11 +2,11 @@
 # Copyright(c) 2017 Intel Corporation.
 # Copyright(c) 2017 Cavium, Inc
 
-# for checking defines we need to use the correct compiler flags
-march_opt = '-march=@0@'.format(machine)
-
-arm_force_native_march = false
-arm_force_default_march = (machine == 'default')
+if machine == 'native'
+	# arm doesn't support a native build - user input of soc is required
+	# default to the portable build instead of native
+	machine = 'default'
+endif
 
 flags_common_default = [
 	# Accelarate rte_memcpy. Be sure to run unit test (memcpy_perf_autotest)
@@ -131,6 +131,7 @@ impl_dpaa = ['NXP DPAA', flags_dpaa, machine_args_generic]
 dpdk_conf.set('RTE_FORCE_INTRINSICS', 1)
 
 if not dpdk_conf.get('RTE_ARCH_64')
+	# armv7 build
 	dpdk_conf.set('RTE_CACHE_LINE_SIZE', 64)
 	dpdk_conf.set('RTE_ARCH_ARM', 1)
 	dpdk_conf.set('RTE_ARCH_ARMv7', 1)
@@ -138,41 +139,9 @@ if not dpdk_conf.get('RTE_ARCH_64')
 	# mk/machine/armv7a/rte.vars.mk sets it too
 	machine_args += '-mfpu=neon'
 else
+	# aarch64 build
 	dpdk_conf.set('RTE_CACHE_LINE_SIZE', 128)
 	dpdk_conf.set('RTE_ARCH_ARM64', 1)
-
-	machine = []
-	cmd_generic = ['generic', '', '', 'default', '']
-	cmd_output = cmd_generic # Set generic by default
-	machine_args = [] # Clear previous machine args
-	if arm_force_default_march and not meson.is_cross_build()
-		machine = impl_generic
-		impl_pn = 'default'
-	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
-	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)
-	endif
-
 	# Apply Common Defaults. These settings may be overwritten by machine
 	# settings later.
 	foreach flag: flags_common_default
@@ -181,30 +150,89 @@ else
 		endif
 	endforeach
 
-	message('Implementer : ' + machine[0])
-	foreach flag: machine[1]
+	soc = machine.split('-')[0]
+	# TODO make sure the subdir exists
+	subdir(soc)
+
+	if soc != 'default'
+		# combine common and soc specific flags
+		# TODO check that soc is in the dict
+		flags = flags['common'] + flags[soc]
+	endif
+
+	foreach flag: 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
+	verified_machine_args = []
+
+	foreach flag: machine_args
+		if cc.has_argument(flag)
+			verified_machine_args += flag
+		else
+			message('Unsupported machine flag "@0@", ignoring'.format(flag))
 		endif
 	endforeach
+	machine_args = verified_machine_args
+
+#	machine = []
+#	cmd_generic = ['generic', '', '', 'default', '']
+#	cmd_output = cmd_generic # Set generic by default
+#	machine_args = [] # Clear previous machine args
+#	if arm_force_default_march and not meson.is_cross_build()
+#		machine = impl_generic
+#		impl_pn = 'default'
+#	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
+#	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)
+#	endif
+#
+#	message('Implementer : ' + machine[0])
+#	foreach flag: machine[1]
+#		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) != '')
@@ -225,3 +253,6 @@ if cc.get_define('__ARM_FEATURE_CRYPTO', args: machine_args) != ''
 	compile_time_cpuflags += ['RTE_CPUFLAG_AES', 'RTE_CPUFLAG_PMULL',
 	'RTE_CPUFLAG_SHA1', 'RTE_CPUFLAG_SHA2']
 endif
+
+message('dpdk conf options after arm stuff: @0@'.format(dpdk_conf))
+
diff --git a/config/arm/arm64_thunderx_linux_gcc b/config/arm/thunderx/arm64_thunderx_linux_gcc
similarity index 92%
rename from config/arm/arm64_thunderx_linux_gcc
rename to config/arm/thunderx/arm64_thunderx_linux_gcc
index 6572ab615..e53a86e8f 100644
--- a/config/arm/arm64_thunderx_linux_gcc
+++ b/config/arm/thunderx/arm64_thunderx_linux_gcc
@@ -13,4 +13,4 @@ cpu = 'armv8-a'
 endian = 'little'
 
 [properties]
-implementor_id = '0x43'
+machine = 'thunderx'
diff --git a/config/arm/thunderx/meson.build b/config/arm/thunderx/meson.build
new file mode 100644
index 000000000..873d79a64
--- /dev/null
+++ b/config/arm/thunderx/meson.build
@@ -0,0 +1,18 @@
+flags = {
+	'common': [
+		['RTE_CACHE_LINE_SIZE', 128],
+		['RTE_MAX_VFIO_GROUPS', 128],
+		['RTE_MACHINE', '"thunderx"'],
+		['RTE_USE_C11_MEM_MODEL', false]
+	],
+	'thunderx': [
+		['RTE_MAX_NUMA_NODES', 2],
+		['RTE_MAX_LCORE', 96]
+	],
+	'thunderx-1n-48c': [
+		['RTE_MAX_NUMA_NODES', 1],
+		['RTE_MAX_LCORE', 48]
+	]
+}
+
+machine_args = ['-march=armv8-a+crc+crypto','-mcpu=thunderx']
diff --git a/config/arm/thunderxt88/arm64_thunderxt88_linux_gcc b/config/arm/thunderxt88/arm64_thunderxt88_linux_gcc
new file mode 100644
index 000000000..9a622786c
--- /dev/null
+++ b/config/arm/thunderxt88/arm64_thunderxt88_linux_gcc
@@ -0,0 +1,16 @@
+[binaries]
+c = 'aarch64-linux-gnu-gcc'
+cpp = 'aarch64-linux-gnu-cpp'
+ar = 'aarch64-linux-gnu-gcc-ar'
+strip = 'aarch64-linux-gnu-strip'
+pkgconfig = 'aarch64-linux-gnu-pkg-config'
+pcap-config = ''
+
+[host_machine]
+system = 'linux'
+cpu_family = 'aarch64'
+cpu = 'armv8-a'
+endian = 'little'
+
+[properties]
+machine = 'thunderxt88'
diff --git a/config/arm/thunderxt88/meson.build b/config/arm/thunderxt88/meson.build
new file mode 100644
index 000000000..2aa5d2cdd
--- /dev/null
+++ b/config/arm/thunderxt88/meson.build
@@ -0,0 +1,18 @@
+flags = {
+	'common': [
+		['RTE_CACHE_LINE_SIZE', 128],
+		['RTE_MAX_VFIO_GROUPS', 128],
+		['RTE_MACHINE', '"thunderx"'],
+		['RTE_USE_C11_MEM_MODEL', false]
+	],
+	'thunderxt88': [
+		['RTE_MAX_NUMA_NODES', 2],
+		['RTE_MAX_LCORE', 96]
+	],
+	'thunderxt88-1n-48c': [
+		['RTE_MAX_NUMA_NODES', 1],
+		['RTE_MAX_LCORE', 48]
+	]
+}
+
+machine_args = ['-mcpu=thunderxt88']
diff --git a/config/meson.build b/config/meson.build
index 69f2aeb60..177cbd49c 100644
--- a/config/meson.build
+++ b/config/meson.build
@@ -63,7 +63,14 @@ meson.add_install_script('../buildtools/symlink-drivers-solibs.sh',
 
 # set the machine type and cflags for it
 if meson.is_cross_build()
-	machine = host_machine.cpu()
+	if not host_machine.cpu_family().startswith('aarch')
+		# don't change the machine config for aarch32/64 builds
+		# that config is set in the cross file to identify the soc
+		# we're building for
+		machine = host_machine.cpu()
+	else
+		machine = meson.get_cross_property('machine', 'default')
+	endif
 else
 	machine = get_option('machine')
 endif
-- 
2.20.1