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From:   Krzysztof Kozlowski <krzk@kernel.org>
Date:   Mon, 25 Mar 2019 11:53:34 +0100
Message-ID: <CAJKOXPe7h6DCSAyQ9v-UkyMnUXnYhop_HCwLKM-B=+tPJpRrrA@mail.gmail.com>
Subject: Re: [PATCH 1/3] ARM: use arch_extension directive instead of arch argument
To:     Stefan Agner <stefan@agner.ch>
Cc:     linux@armlinux.org.uk, arnd@arndb.de, ard.biesheuvel@linaro.org,
        robin.murphy@arm.com, nicolas.pitre@linaro.org,
        f.fainelli@gmail.com, rjui@broadcom.com, sbranden@broadcom.com,
        bcm-kernel-feedback-list@broadcom.com, kgene@kernel.org,
        robh@kernel.org, ssantosh@kernel.org, jason@lakedaemon.net,
        andrew@lunn.ch, gregory.clement@bootlin.com,
        sebastian.hesselbarth@gmail.com, tony@atomide.com,
        marc.w.gonzalez@free.fr, mans@mansr.com, ndesaulniers@google.com,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
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On Sat, 23 Mar 2019 at 16:52, Stefan Agner <stefan@agner.ch> wrote:
>
> The LLVM Target parser currently does not allow to specify the security
> extension as part of -march (see also LLVM Bug 40186 [0]). When trying
> to use Clang with LLVM's integrated assembler, this leads to a build
> errors such as this:
>   clang-8: error: the clang compiler does not support '-Wa,-march=armv7-a+sec'
>
> Use ".arch_extension sec" to enable the security extension in a more
> portable fasion.
>
> Note that this is technically not exactly the same as the old code
> checked for availabilty of the security extension by calling as-instr.
> However, there are already other sites which use ".arch_extension sec"
> unconditionally, hence de-facto we need an assembler capable of
> ".arch_extension sec" already today (arch/arm/mm/proc-v7.S). The
> arch extension "sec" is available since binutils 2.21 according to
> its documentation [1].
>
> [0] https://bugs.llvm.org/show_bug.cgi?id=40186
> [1] https://sourceware.org/binutils/docs-2.21/as/ARM-Options.html
>
> Signed-off-by: Stefan Agner <stefan@agner.ch>
> ---
>  arch/arm/mach-bcm/Makefile         | 3 ---
>  arch/arm/mach-bcm/bcm_kona_smc.c   | 2 --
>  arch/arm/mach-exynos/Makefile      | 4 ----
>  arch/arm/mach-exynos/exynos-smc.S  | 2 +-
>  arch/arm/mach-exynos/sleep.S       | 2 +-

for Exynos:
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>

Best regards,
Krzysztof