Re: [dpdk-dev] [PATCH v8 2/2] net/hns3: refactor SVE code compile method

[fengchengwen <fengchengwen@huawei.com>]

Friendly ping


On 2021/5/27 15:07, Fengchengwen wrote:
> 
> Hi, Ferruh
> 
>     Could you review this patch ? Thanks
> 
> 
> From:Ruifeng Wang <Ruifeng.Wang@arm.com>
> To:Fengchengwen <fengchengwen@huawei.com>;Thomas Monjalon <thomas@monjalon.net>;ferruh.yigit <ferruh.yigit@intel.com>
> Cc:dev <dev@dpdk.org>;Jerin Jacob <jerinj@marvell.com>;viktorin <viktorin@rehivetech.com>;Richardson, Bruce <bruce.richardson@intel.com>;Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>;jerinjacobk <jerinjacobk@gmail.com>;Juraj Linkeš <juraj.linkes@pantheon.tech>;nd <nd@arm.com>;nd <nd@arm.com>
> Date:2021-05-25 14:04:52
> Subject:RE: [PATCH v8 2/2] net/hns3: refactor SVE code compile method
> 
>> -----Original Message-----
>> From: Chengwen Feng < fengchengwen@huawei.com<mailto:fengchengwen@huawei.com>>
>> Sent: Monday, May 24, 2021 9:23 PM
>> To: thomas@monjalon.net<mailto:thomas@monjalon.net>; ferruh.yigit@intel.com<mailto:ferruh.yigit@intel.com>
>> Cc: dev@dpdk.org<mailto:dev@dpdk.org>; jerinj@marvell.com<mailto:jerinj@marvell.com>; Ruifeng Wang
>> < Ruifeng.Wang@arm.com<mailto:Ruifeng.Wang@arm.com>>; viktorin@rehivetech.com<mailto:viktorin@rehivetech.com>;
>> bruce.richardson@intel.com<mailto:bruce.richardson@intel.com>; Honnappa Nagarahalli
>> < Honnappa.Nagarahalli@arm.com<mailto:Honnappa.Nagarahalli@arm.com>>; jerinjacobk@gmail.com<mailto:jerinjacobk@gmail.com>;
>> juraj.linkes@pantheon.tech<mailto:juraj.linkes@pantheon.tech>; nd < nd@arm.com<mailto:nd@arm.com>>
>> Subject: [PATCH v8 2/2] net/hns3: refactor SVE code compile method
>>
>> Currently, the SVE code is compiled only when -march supports SVE (e.g. '-
>> march=armv8.2a+sve'), there maybe some problem[1] with this approach.
>>
>> The solution:
>> a. If the minimum instruction set support SVE then compiles it.
>> b. Else if the compiler support SVE then compiles it.
>> c. Otherwise don't compile it.
>>
>> Note: this patch also fixes compile error with gcc8.3 + '-march=armv8.a+sve',
>> the error is arm_sve.h no such file or directory.
>>
>> [1] https://mails.dpdk.org/archives/dev/2021-April/208189.html
>>
>> Fixes: 8c25b02b082a ("net/hns3: fix enabling SVE Rx/Tx")
>> Fixes: 952ebacce4f2 ("net/hns3: support SVE Rx")
>> Cc: stable@dpdk.org<mailto:stable@dpdk.org>
>>
>> Signed-off-by: Chengwen Feng < fengchengwen@huawei.com<mailto:fengchengwen@huawei.com>>
>> ---
>> drivers/net/hns3/hns3_rxtx.c | 2 +-
>> drivers/net/hns3/meson.build | 20 +++++++++++++++++++-
>> 2 files changed, 20 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/net/hns3/hns3_rxtx.c b/drivers/net/hns3/hns3_rxtx.c
>> index 1d7a769..9b2f082 100644
>> --- a/drivers/net/hns3/hns3_rxtx.c
>> +++ b/drivers/net/hns3/hns3_rxtx.c
>> @@ -2808,7 +2808,7 @@ hns3_get_default_vec_support(void)
>> static bool
>> hns3_get_sve_support(void)
>> {
>> -#if defined(RTE_ARCH_ARM64) && defined(__ARM_FEATURE_SVE)
>> +#if defined(CC_SVE_ACLE_SUPPORT)
>>        if (rte_vect_get_max_simd_bitwidth() < RTE_VECT_SIMD_256)
>>                return false;
>>        if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_SVE))
>> diff --git a/drivers/net/hns3/meson.build b/drivers/net/hns3/meson.build
>> index 53c7df7..aabcf23 100644
>> --- a/drivers/net/hns3/meson.build
>> +++ b/drivers/net/hns3/meson.build
>> @@ -35,7 +35,25 @@ deps += ['hash']
>>
>> if arch_subdir == 'arm' and dpdk_conf.get('RTE_ARCH_64')
>>      sources += files('hns3_rxtx_vec.c')
>> -    if cc.get_define('__ARM_FEATURE_SVE', args: machine_args) != ''
>> +
>> +    # compile SVE when:
>> +    # a. support SVE in minimum instruction set baseline
>> +    # b. it's not minimum instruction set, but compiler support
>> +    if dpdk_conf.has('CC_SVE_ACLE_SUPPORT')
>>          sources += files('hns3_rxtx_vec_sve.c')
>> +    elif cc.has_argument('-march=armv8.2-a+sve') and
>> cc.check_header('arm_sve.h')
>> +        cflags += ['-DCC_SVE_ACLE_SUPPORT=1']
>> +        sve_cflags = []
>> +        foreach flag: cflags
>> +            if not (flag.startswith('-march=') or flag.startswith('-mcpu=') or
>> flag.startswith('-mtune='))
>> +                sve_cflags += flag
>> +            endif
>> +        endforeach
>> +        hns3_sve_lib = static_library('hns3_sve_lib',
>> +                        'hns3_rxtx_vec_sve.c',
>> +                        dependencies: [static_rte_ethdev],
>> +                        include_directories: includes,
>> +                        c_args: [sve_cflags, '-march=armv8.2-a+sve'])
>> +        objs += hns3_sve_lib.extract_objects('hns3_rxtx_vec_sve.c')
>>      endif
>> endif
>> --
>> 2.8.1
> 
> Reviewed-by: Ruifeng Wang < ruifeng.wang@arm.com<mailto:ruifeng.wang@arm.com>>
>