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From:   =?utf-8?B?QmrDtnJuIFTDtnBlbA==?= <bjorn@kernel.org>
To:     Jessica Clarke <jrtc27@jrtc27.com>
Cc:     Heiko Stuebner <heiko@sntech.de>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        linux-riscv <linux-riscv@lists.infradead.org>,
        Paul Walmsley <paul.walmsley@sifive.com>,
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        Conor Dooley <conor.dooley@microchip.com>,
        matthias.bgg@gmail.com,
        Heinrich Schuchardt <heinrich.schuchardt@canonical.com>,
        Greentime Hu <greentime.hu@sifive.com>, nick.knight@sifive.com,
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        richard.henderson@linaro.org, arnd@arndb.de,
        linux-kernel@vger.kernel.org,
        Heiko Stuebner <heiko.stuebner@vrull.eu>
Subject: Re: [PATCH 0/4] Expose the isa-string via the AT_BASE_PLATFORM aux
 vector
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 <87ednz7roh.fsf@all.your.base.are.belong.to.us>
 <7DD2C38C-CBB3-41EE-A195-50E4C2451B7E@jrtc27.com>
Date:   Tue, 02 May 2023 07:48:10 +0200
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Jessica Clarke <jrtc27@jrtc27.com> writes:

> All I wanted was some simple extension string -> version number function
> as a standardised userspace interface... because at the end of the day
> people just want to know =E2=80=9Ccan I use extension Y?=E2=80=9D, possib=
ly with a
> minimum version. But maybe there=E2=80=99s some hope that Linux libcs will
> translate such queries into poking at this hwprobe thing.

Using hwprobe to plumb such an interface for, say libcs, was what I was
envisioning.

> Though god knows what they=E2=80=99re going to do about vendor extensions,
> especially if those vendor extensions only get supported in vendor
> forks of the kernel (who=E2=80=99s allocating their encodings? Xvendorfoo
> exists to namespace them and give vendors control...).

"they're"? I'm sure your input on how to design such an interface would
be be much appreciated!

My view is that the "design upfront" strategy here hasn't really worked
out, so the hwprobe approach is to start small, and extend when there's
need. Hopefully, there will be fewer pains with this approach.

That's why I was very surprised to see this series, which introduces Yet
Another Interface.


Bj=C3=B6rn