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

[Fengchengwen]

Hi, Ferruh

    Could you review this patch ? Thanks


From:Ruifeng Wang <Ruifeng.Wang at arm.com>
To:Fengchengwen <fengchengwen at huawei.com>;Thomas Monjalon <thomas at monjalon.net>;ferruh.yigit <ferruh.yigit at intel.com>
Cc:dev <dev at dpdk.org>;Jerin Jacob <jerinj at marvell.com>;viktorin <viktorin at rehivetech.com>;Richardson, Bruce <bruce.richardson at intel.com>;Honnappa Nagarahalli <Honnappa.Nagarahalli at arm.com>;jerinjacobk <jerinjacobk at gmail.com>;Juraj Linkeš <juraj.linkes at pantheon.tech>;nd <nd at arm.com>;nd <nd at 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 at huawei.com<mailto:fengchengwen at huawei.com>>
> Sent: Monday, May 24, 2021 9:23 PM
> To: thomas at monjalon.net<mailto:thomas at monjalon.net>; ferruh.yigit at intel.com<mailto:ferruh.yigit at intel.com>
> Cc: dev at dpdk.org<mailto:dev at dpdk.org>; jerinj at marvell.com<mailto:jerinj at marvell.com>; Ruifeng Wang
> < Ruifeng.Wang at arm.com<mailto:Ruifeng.Wang at arm.com>>; viktorin at rehivetech.com<mailto:viktorin at rehivetech.com>;
> bruce.richardson at intel.com<mailto:bruce.richardson at intel.com>; Honnappa Nagarahalli
> < Honnappa.Nagarahalli at arm.com<mailto:Honnappa.Nagarahalli at arm.com>>; jerinjacobk at gmail.com<mailto:jerinjacobk at gmail.com>;
> juraj.linkes at pantheon.tech<mailto:juraj.linkes at pantheon.tech>; nd < nd at arm.com<mailto:nd at 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 at dpdk.org<mailto:stable at dpdk.org>
>
> Signed-off-by: Chengwen Feng < fengchengwen at huawei.com<mailto:fengchengwen at 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 at arm.com<mailto:ruifeng.wang at arm.com>>