[dpdk-dev] [PATCH] build: add support for detecting march on ARM
Pavan Nikhilesh
pbhagavatula at caviumnetworks.com
Sat Dec 30 17:37:54 CET 2017
Added support for detecting march and mcpu by reading midr_el1 register.
The implementer, primary part number values read can be used to figure
out the underlying arm cpu.
Signed-off-by: Pavan Nikhilesh <pbhagavatula at caviumnetworks.com>
---
The current method used for reading MIDR_EL1 form userspace might not be
reliable and can be easily modified by updating config/arm/machine.py.
More info on midr_el1 can be found at
http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0500g/BABFEABI.html
This patch depends on http://dpdk.org/dev/patchwork/patch/32410/
config/arm/machine.py | 18 ++++++++++++++++++
config/arm/meson.build | 20 ++++++++++++++++++++
config/meson.build | 3 ++-
drivers/meson.build | 2 +-
examples/meson.build | 2 +-
lib/meson.build | 2 +-
meson.build | 2 +-
7 files changed, 44 insertions(+), 5 deletions(-)
create mode 100755 config/arm/machine.py
diff --git a/config/arm/machine.py b/config/arm/machine.py
new file mode 100755
index 000000000..3c6e7b6a7
--- /dev/null
+++ b/config/arm/machine.py
@@ -0,0 +1,18 @@
+#!/usr/bin/python
+import pprint
+pp = pprint
+
+ident = []
+fname = '/sys/devices/system/cpu/cpu0/regs/identification/midr_el1'
+with open(fname) as f:
+ content = f.read()
+
+midr_el1 = (int(content.rstrip('\n'), 16))
+
+ident.append(hex((midr_el1 >> 24) & 0xFF)) # Implementer
+ident.append(hex((midr_el1 >> 20) & 0xF)) # Variant
+ident.append(hex((midr_el1 >> 16) & 0XF)) # Architecture
+ident.append(hex((midr_el1 >> 4) & 0xFFF)) # Primary Part number
+ident.append(hex(midr_el1 & 0xF)) # Revision
+
+print(' '.join(ident))
diff --git a/config/arm/meson.build b/config/arm/meson.build
index 250958415..f6ae69c21 100644
--- a/config/arm/meson.build
+++ b/config/arm/meson.build
@@ -41,3 +41,23 @@ else
endif
dpdk_conf.set('RTE_CACHE_LINE_SIZE', 128)
dpdk_conf.set('RTE_FORCE_INTRINSICS', 1)
+
+detect_vendor = find_program(join_paths(meson.current_source_dir(),
+ 'machine.py'))
+cmd = run_command(detect_vendor.path())
+if cmd.returncode() != 0
+ message('Unable to read midr_el1')
+else
+ cmd_output = cmd.stdout().strip().split(' ')
+ message('midr_el1 output: \n' + 'Implementor ' + cmd_output[0] +
+ ' Variant ' + cmd_output[1] + ' Architecture ' +
+ cmd_output[2] + ' Primary Part number ' + cmd_output[3]
+ + ' Revision ' + cmd_output[4])
+ if cmd_output[0] == '0x43'
+ message('Implementor : Cavium')
+ dpdk_conf.set('RTE_MACHINE', 'thunderx')
+ machine_arg = []
+ machine_arg += '-march=' + 'armv8-a+crc+crypto'
+ machine_arg += '-mcpu=' + 'thunderx'
+ endif
+endif
diff --git a/config/meson.build b/config/meson.build
index 86e978fb1..fe8104676 100644
--- a/config/meson.build
+++ b/config/meson.build
@@ -8,7 +8,8 @@ else
machine = get_option('machine')
endif
dpdk_conf.set('RTE_MACHINE', machine)
-machine_arg = '-march=' + machine
+machine_arg = []
+machine_arg += '-march=' + machine
# use pthreads
add_project_link_arguments('-pthread', language: 'c')
diff --git a/drivers/meson.build b/drivers/meson.build
index 9b5039847..f5009aa2e 100644
--- a/drivers/meson.build
+++ b/drivers/meson.build
@@ -22,7 +22,7 @@ foreach class:driver_classes
version = 1
sources = []
objs = []
- cflags = [machine_arg]
+ cflags = machine_arg
includes = [include_directories(drv_path)]
# set up internal deps. Drivers can append/override as necessary
deps = std_deps
diff --git a/examples/meson.build b/examples/meson.build
index 0abed7169..88df650cf 100644
--- a/examples/meson.build
+++ b/examples/meson.build
@@ -9,7 +9,7 @@ endif
foreach example: get_option('examples').split(',')
name = example
sources = []
- cflags = [machine_arg]
+ cflags = machine_arg
ext_deps = []
includes = [include_directories(example)]
deps = ['eal', 'mempool', 'net', 'mbuf', 'ethdev', 'cmdline']
diff --git a/lib/meson.build b/lib/meson.build
index 0c94d74b9..3c98efa70 100644
--- a/lib/meson.build
+++ b/lib/meson.build
@@ -31,7 +31,7 @@ foreach l:libraries
sources = []
headers = []
includes = []
- cflags = [machine_arg]
+ cflags = machine_arg
objs = [] # other object files to link against, used e.g. for
# instruction-set optimized versions of code
diff --git a/meson.build b/meson.build
index 3dce8579e..493bcc313 100644
--- a/meson.build
+++ b/meson.build
@@ -66,5 +66,5 @@ pkg.generate(name: meson.project_name(),
['-Wl,-Bdynamic'] + dpdk_extra_ldflags,
description: 'The Data Plane Development Kit (DPDK)',
subdirs: [get_option('include_subdir_arch'), '.'],
- extra_cflags: ['-include "rte_config.h"', machine_arg]
+ extra_cflags: ['-include "rte_config.h"'] + machine_arg
)
--
2.15.1
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