Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
MIME-Version: 1.0
References: <c41cc67321d0b366e356440e6dbc9eceb1babfe4.1583105749.git.stefan@agner.ch>
In-Reply-To: <c41cc67321d0b366e356440e6dbc9eceb1babfe4.1583105749.git.stefan@agner.ch>
From:   Ard Biesheuvel <ard.biesheuvel@linaro.org>
Date:   Wed, 4 Mar 2020 08:39:54 +0100
Message-ID: <CAKv+Gu-myRS5FWEVucdpS5zUXM+UjBdMGCiFbgu0=3=T8-9LFQ@mail.gmail.com>
Subject: Re: [PATCH] crypto: arm/ghash-ce - define fpu before fpu registers
 are referenced
To:     Stefan Agner <stefan@agner.ch>
Cc:     Herbert Xu <herbert@gondor.apana.org.au>,
        "David S. Miller" <davem@davemloft.net>,
        Russell King <linux@armlinux.org.uk>,
        Manoj Gupta <manojgupta@google.com>,
        Jian Cai <jiancai@google.com>,
        "open list:HARDWARE RANDOM NUMBER GENERATOR CORE" 
        <linux-crypto@vger.kernel.org>,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        clang-built-linux <clang-built-linux@googlegroups.com>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Mon, 2 Mar 2020 at 00:37, Stefan Agner <stefan@agner.ch> wrote:
>
> Building ARMv7 with Clang's integrated assembler leads to errors such
> as:
> arch/arm/crypto/ghash-ce-core.S:34:11: error: register name expected
>  t3l .req d16
>           ^
>
> Since no FPU has selected yet Clang considers d16 not a valid register.
> Moving the FPU directive on-top allows Clang to parse the registers and
> allows to successfully build this file with Clang's integrated assembler.
>
> Signed-off-by: Stefan Agner <stefan@agner.ch>

Acked-by: Ard Biesheuvel <ardb@kernel.org>

> ---
>  arch/arm/crypto/ghash-ce-core.S | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/crypto/ghash-ce-core.S b/arch/arm/crypto/ghash-ce-core.S
> index 534c9647726d..9f51e3fa4526 100644
> --- a/arch/arm/crypto/ghash-ce-core.S
> +++ b/arch/arm/crypto/ghash-ce-core.S
> @@ -8,6 +8,9 @@
>  #include <linux/linkage.h>
>  #include <asm/assembler.h>
>
> +       .arch           armv8-a
> +       .fpu            crypto-neon-fp-armv8
> +
>         SHASH           .req    q0
>         T1              .req    q1
>         XL              .req    q2
> @@ -88,8 +91,6 @@
>         T3_H            .req    d17
>
>         .text
> -       .arch           armv8-a
> -       .fpu            crypto-neon-fp-armv8
>
>         .macro          __pmull_p64, rd, rn, rm, b1, b2, b3, b4
>         vmull.p64       \rd, \rn, \rm
> --
> 2.25.1
>