From: Catalin Marinas <catalin.marinas@arm.com>
To: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org,
Marc Zyngier <maz@kernel.org>, Ard Biesheuvel <ardb@kernel.org>,
Arnd Bergmann <arnd@arndb.de>, Hanjun Guo <guohanjun@huawei.com>,
Jonathan Cameron <Jonathan.Cameron@huawei.com>,
Guenter Roeck <linux@roeck-us.net>
Subject: Re: [PATCH] arm64: Kconfig: Make CPU_BIG_ENDIAN depend on BROKEN
Date: Fri, 19 Sep 2025 22:10:04 +0100 [thread overview]
Message-ID: <aM3GrAkwAgim0UIO@arm.com> (raw)
In-Reply-To: <20250919184025.15416-1-will@kernel.org>
On Fri, Sep 19, 2025 at 07:40:25PM +0100, Will Deacon wrote:
> Big-endian arm64 configurations are vanishingly rare, yet we still claim
> to support them in Linux despite very limited testing or visible
> interest. Supporting big-endian adds unnecessary burden to reviewers and
> contributors which, without any known active users, is hard to justify.
> For example, recent work to improve our futex routines and to implement
> nested virtualisation support is non-trivially complicated by having to
> support both big- and little-endianness.
>
> Back in 2019 [1], it was claimed that Huawei were using arm64 big-endian
> machines in their telecommunication products but I don't know whether
> that's still the case and certainly haven't seen any patch contributions
> to help support or maintain it.
>
> Make CPU_BIG_ENDIAN depend on BROKEN as an initial deprecation step
> towards its removal.
>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Marc Zyngier <maz@kernel.org>
> Cc: Ard Biesheuvel <ardb@kernel.org>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Hanjun Guo <guohanjun@huawei.com>
> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Cc: Guenter Roeck <linux@roeck-us.net>
> Link: https://lore.kernel.org/linux-arm-kernel/73701e9f-bee1-7ae8-2277-7a3576171cd4@huawei.com/ [1]
> Signed-off-by: Will Deacon <will@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
next prev parent reply other threads:[~2025-09-19 21:10 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-19 18:40 [PATCH] arm64: Kconfig: Make CPU_BIG_ENDIAN depend on BROKEN Will Deacon
2025-09-19 19:00 ` Ard Biesheuvel
2025-09-19 20:56 ` Marc Zyngier
2025-09-19 21:10 ` Catalin Marinas [this message]
2025-09-24 16:09 ` Guenter Roeck
2025-09-25 13:01 ` Will Deacon
2025-09-25 22:54 ` Guenter Roeck
2025-09-24 16:09 ` Will Deacon
2025-09-27 1:44 ` Hanjun Guo
2025-09-29 0:18 ` J. Neuschäfer
2025-09-29 10:52 ` Catalin Marinas
2025-09-29 20:16 ` J. Neuschäfer
2025-09-30 8:57 ` Marc Zyngier
2025-10-01 9:29 ` A. Wilcox
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