Date:   Mon, 27 Feb 2023 22:19:54 +0000
From:   Conor Dooley <conor@kernel.org>
To:     Evan Green <evan@rivosinc.com>
Cc:     Palmer Dabbelt <palmer@rivosinc.com>, heiko@sntech.de,
        slewis@rivosinc.com, vineetg@rivosinc.com,
        Albert Ou <aou@eecs.berkeley.edu>,
        Andrew Bresticker <abrestic@rivosinc.com>,
        Andrew Jones <ajones@ventanamicro.com>,
        Anup Patel <apatel@ventanamicro.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Atish Patra <atishp@rivosinc.com>,
        Bagas Sanjaya <bagasdotme@gmail.com>,
        Celeste Liu <coelacanthus@outlook.com>,
        Conor Dooley <conor.dooley@microchip.com>,
        Guo Ren <guoren@kernel.org>, Jonathan Corbet <corbet@lwn.net>,
        Niklas Cassel <niklas.cassel@wdc.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Randy Dunlap <rdunlap@infradead.org>,
        Ruizhe Pan <c141028@gmail.com>,
        Sunil V L <sunilvl@ventanamicro.com>,
        Tobias Klauser <tklauser@distanz.ch>,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-riscv@lists.infradead.org
Subject: Re: [PATCH v3 2/7] RISC-V: Add a syscall for HW probing
Message-ID: <Y/0sikPIVR3j7cKI@spud>
References: <20230221190858.3159617-1-evan@rivosinc.com>
 <20230221190858.3159617-3-evan@rivosinc.com>
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On Tue, Feb 21, 2023 at 11:08:53AM -0800, Evan Green wrote:
> We don't have enough space for these all in ELF_HWCAP{,2} and there's no
> system call that quite does this, so let's just provide an arch-specific
> one to probe for hardware capabilities.  This currently just provides
> m{arch,imp,vendor}id, but with the key-value pairs we can pass more in
> the future.
>=20
> Co-developed-by: Palmer Dabbelt <palmer@rivosinc.com>
> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
> Signed-off-by: Evan Green <evan@rivosinc.com>

> +static
> +int do_riscv_hwprobe(struct riscv_hwprobe __user *pairs, long pair_count,
> +		      long cpu_count, unsigned long __user *cpus_user,
> +		      unsigned long flags)

I almost feel bad commenting this, but this is now the only function
split like this w/ the static on its own line.

With the same caveat about ignorance about glibc's desires & lingering
doubt as to whether this interface is the right way to go, this looks
good to me now.
I'm reluctant to give an R-b for the latter reason, but assuming the
Higher Power deem this approach acceptable:
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>

Cheers,
Conor.

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