Re: [dpdk-dev] [PATCH v7 2/4] meson: add infra to support machine specific flags

[Yongseok Koh <yskoh@mellanox.com>]

> On Apr 9, 2019, at 5:40 PM, Yongseok Koh <yskoh@mellanox.com> wrote:
> 
>> 
>> On Apr 6, 2019, at 7:27 AM, jerinjacobk@gmail.com wrote:
>> 
>> From: Pavan Nikhilesh <pbhagavatula@marvell.com>
>> 
>> Currently, RTE_* flags are set based on the implementer ID but there might
>> be some micro arch specific differences from the same vendor
>> eg. CACHE_LINESIZE. Add support to set micro arch specific flags.
>> 
>> Signed-off-by: Pavan Nikhilesh <pbhagavatula@marvell.com>
>> Signed-off-by: Jerin Jacob <jerinj@marvell.com>
>> ---
>> config/arm/meson.build | 37 ++++++++++++++++++++++++++++++++-----
>> 1 file changed, 32 insertions(+), 5 deletions(-)
>> 
>> diff --git a/config/arm/meson.build b/config/arm/meson.build
>> index 170a4981a..8de3f3e3a 100644
>> --- a/config/arm/meson.build
>> +++ b/config/arm/meson.build
>> @@ -52,12 +52,10 @@ flags_generic = [
>> 	['RTE_USE_C11_MEM_MODEL', true],
>> 	['RTE_CACHE_LINE_SIZE', 128]]
>> flags_cavium = [
>> -	['RTE_MACHINE', '"thunderx"'],
>> 	['RTE_CACHE_LINE_SIZE', 128],
>> 	['RTE_MAX_NUMA_NODES', 2],
>> 	['RTE_MAX_LCORE', 96],
>> -	['RTE_MAX_VFIO_GROUPS', 128],
>> -	['RTE_USE_C11_MEM_MODEL', false]]
>> +	['RTE_MAX_VFIO_GROUPS', 128]]
>> flags_dpaa = [
>> 	['RTE_MACHINE', '"dpaa"'],
>> 	['RTE_USE_C11_MEM_MODEL', true],
>> @@ -71,6 +69,27 @@ flags_dpaa2 = [
>> 	['RTE_MAX_NUMA_NODES', 1],
>> 	['RTE_MAX_LCORE', 16],
>> 	['RTE_LIBRTE_DPAA2_USE_PHYS_IOVA', false]]
>> +flags_default_extra = []
>> +flags_thunderx_extra = [
>> +	['RTE_MACHINE', '"thunderx"'],
>> +	['RTE_USE_C11_MEM_MODEL', false]]
>> +
>> +machine_args_generic = [
>> +	['default', ['-march=armv8-a+crc+crypto']],
>> +	['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']]]
>> +
>> +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]]
> 
> Looks like there's a mistake in rebasing it?
> You should've removed machine_args_generic and machine_args_cavium
> in the beginning of this file.
> 
> Other than that, it looks good to me.
> 
> BTW, thanks for the patch. I raised this issue before and I was supposed to
> make the change but you have taken it.
> 
> Yongseok
> 
>> ## Arm implementer ID (ARM DDI 0487C.a, Section G7.2.106, Page G7-5321)
>> impl_generic = ['Generic armv8', flags_generic, machine_args_generic]
>> @@ -157,8 +176,16 @@ else
>> 	endif
>> 	foreach marg: machine[2]
>> 		if marg[0] == impl_pn
>> -			foreach f: marg[1]
>> -				machine_args += f
>> +			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

And setting the extra flags doesn't work well with gcc < 7 because of the following,

        # Primary part number based mcpu flags are supported
        # for gcc versions > 7
        if cc.version().version_compare(
                        '<7.0') or cmd_output.length() == 0
                if not meson.is_cross_build() and arm_force_native_march == true
                        impl_pn = 'native'
                else
                        impl_pn = 'default'
                endif
        endif

Thanks,
Yongseok

>> 			endforeach
>> 		endif
>> 	endforeach
>> -- 
>> 2.21.0