Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Wed, 14 Jun 2023 23:00:01 -0700
From:   Christoph Hellwig <hch@infradead.org>
To:     Arnd Bergmann <arnd@arndb.de>
Cc:     Prabhakar <prabhakar.csengg@gmail.com>,
        "Conor.Dooley" <conor.dooley@microchip.com>,
        Geert Uytterhoeven <geert+renesas@glider.be>,
        guoren <guoren@kernel.org>,
        Andrew Jones <ajones@ventanamicro.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Samuel Holland <samuel@sholland.org>,
        linux-riscv@lists.infradead.org,
        Christoph Hellwig <hch@infradead.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
        Biju Das <biju.das.jz@bp.renesas.com>,
        "Lad, Prabhakar" <prabhakar.mahadev-lad.rj@bp.renesas.com>
Subject: Re: [PATCH v9 3/6] riscv: mm: dma-noncoherent: nonstandard cache
 operations support
Message-ID: <ZIqo4TsHJr9vdQaU@infradead.org>
References: <20230614104759.228372-1-prabhakar.mahadev-lad.rj@bp.renesas.com>
 <20230614104759.228372-4-prabhakar.mahadev-lad.rj@bp.renesas.com>
 <4f69fcfe-debb-4979-9070-1d58ba35032c@app.fastmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <4f69fcfe-debb-4979-9070-1d58ba35032c@app.fastmail.com>
Precedence: bulk

On Wed, Jun 14, 2023 at 02:35:44PM +0200, Arnd Bergmann wrote:
> I understand that Christoph will still not like this, but I think this
> is as good as it gets, making the standard variant the fast path,
> and using the function pointers only for the nonstandard cases.

Yes.  And I really do not want to make the non-standard cases easy.
The extension to do cache maintenance have been ratified for a while
and under discussion for much longer.  Adding random crap because
vendors suck is a bad idea, and we should not be adding this crap.