From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3D09812F583 for ; Fri, 19 Apr 2024 15:23:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713540184; cv=none; b=NpwLl6EZwjav0/Untyp56BabneBSQ5MM75ozZG9Z4qNJgMK1N8N6g4UT+Y7P7X7jtHT9EV9g7tOB/AuZAQ55EKRzm9tuiuqNCb5MBXWgaY0FDRO5UqIiaeGLwrQUyJIoyEdhWksiqSuKANXjaQeEj5Je6pqQE5sbhnPNW27Ic+Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713540184; c=relaxed/simple; bh=WgpaSd8gGDM2VtZUXLsdlXMBesxAbl08DIZs+EshcWU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=QajCSQLktNhPsfArfkfQOenoJUTi5vSLhSg5pHjIxCQ/+EI4MW9EdyhZfPf7mQgNgJozYfKfD3OuoGHq0SWO4ZYTO7KlGxtkMHcEfEjNnbv5P9LQQvFU18vBL59mpyWbeDJgAwVrTSBC/1V++U0ugV4C2sq90sgLLAVDdZsjymY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Bq7MJf0A; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Bq7MJf0A" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 23AD5C072AA; Fri, 19 Apr 2024 15:22:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1713540183; bh=WgpaSd8gGDM2VtZUXLsdlXMBesxAbl08DIZs+EshcWU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Bq7MJf0ANxxVvko+MORQK7tkExjxY8t0FWI5XkvrXHcW6V+mywxMoakepDADp5ZGP wzFLOrjI2yZUukXlpppIdA8V3ZIxHTfX3anctFdKP+FtY4RKwQ6fVUC6Ajki9tRUEi 16UR77KQtNzq8EWPZ1NaaCghjMq0JheCv7Q9Es+Ool8LYeMP8GxZRANDBD8S148g7s nwGZLcTr1eycU21O1cCuM9XqOMdZW0hGdA5dz/c8vdw3K30zuwVKpXXx1rz1OJFpO9 BQXrfRZoknTwZlM8x8AYRfzT19g4De/QhALHhRLujMZDHbtq74uMxMT8OIOYoBifJz RxbK0dTlFobrQ== Date: Fri, 19 Apr 2024 16:22:52 +0100 From: Conor Dooley To: Andrew Jones Cc: linux-riscv@lists.infradead.org, kvm-riscv@lists.infradead.org, devicetree@vger.kernel.org, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, conor.dooley@microchip.com, anup@brainfault.org, atishp@atishpatra.org, robh@kernel.org, krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org, christoph.muellner@vrull.eu, heiko@sntech.de, charlie@rivosinc.com, David.Laight@aculab.com, parri.andrea@gmail.com, luxu.kernel@bytedance.com Subject: Re: [PATCH v2 3/6] riscv: Add Zawrs support for spinlocks Message-ID: <20240419-irate-dispute-2714c42f3a63@spud> References: <20240419135321.70781-8-ajones@ventanamicro.com> <20240419135321.70781-11-ajones@ventanamicro.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="28c4hpi9ivVxCwkB" Content-Disposition: inline In-Reply-To: <20240419135321.70781-11-ajones@ventanamicro.com> --28c4hpi9ivVxCwkB Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Fri, Apr 19, 2024 at 03:53:25PM +0200, Andrew Jones wrote: > +config RISCV_ISA_ZAWRS > + bool "Zawrs extension support for more efficient busy waiting" > + depends on RISCV_ALTERNATIVE > + default y > + help > + The Zawrs extension defines instructions to be used in polling loops > + which allow a hart to enter a low-power state or to trap to the > + hypervisor while waiting on a store to a memory location. Enable the > + use of these instructions in the kernel when the Zawrs extension is > + detected at boot. Ignoring the rest of the patch, and focusing on the bit relevant to our other conversation, I think this description satisfies what I was trying to do with the other options in terms of being clear about what exactly it does. --28c4hpi9ivVxCwkB Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRh246EGq/8RLhDjO14tDGHoIJi0gUCZiKMSwAKCRB4tDGHoIJi 0iHgAP0bVRo/k8VGTCVwXeHhxWQfgjD463Unkv1KkQBnmsakhQD/Tkvq1OZjDrZp rJPhWINZM3MPa7ALj6yQ2JG6CVw6ngQ= =5nYv -----END PGP SIGNATURE----- --28c4hpi9ivVxCwkB--