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 0E6E6481B1; Mon, 22 Jan 2024 20:42:23 +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=1705956144; cv=none; b=rXK4EBUCf8k2xrVwa08OKaEbkYz04fuDkH653ZTxiBCwKNJo2MB7MemBP6Iu6YJ2AoKEyoS/Ja+OEso6/Xb0Z3rW6PX4fSqcdkpY5FaD9NYGMHNtyYlpqAgBX/D8jmDkqBASxeKzozU9V5iMlrIZd8LQudXY7fQfYlUV2kdpd2g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705956144; c=relaxed/simple; bh=fjtGYrPLVAgmnbjt+Ekb+IEbQu2c0zwfHg/G7gZsVmI=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=PcFiVrntOcXj4NjIjIlU8ZbzepPDlgrzA5tmsspLCO6WNE2dmR63KIHcmzHyKq6qKK2mzunXkXxMi5hb39bceCQqXQORp6p8GwQW5uKFrM+OX7jVDmvwBL+Wutt4CuV71keJ+3NxNhko+LpCXFp6FWG4xozS1RIlnglLlU10AbA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Gm/qcEFf; 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="Gm/qcEFf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 99D76C43394; Mon, 22 Jan 2024 20:42:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1705956143; bh=fjtGYrPLVAgmnbjt+Ekb+IEbQu2c0zwfHg/G7gZsVmI=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=Gm/qcEFfiSNUvkiYPekzxnCgffzrZrI0Jbe2TkhEzD/a1Bgwo9j9yFsV9UTTPJozG wYPAqCysMsWfPqH/Y4fv9gPhoIhFODWmE55a1CPr0O7yocY3N2t8+C5ldmR/RYqRyy D0zhzdYC5LGHrBZdaZldNRZ/xUd22SbYm+Gxbuab+V6Ycg2im9X1hoyGJa6VJsxmOh ipY42DR0cQy1Ch90ARtStJ1BEYHhKDaah3Q6Dvg7XSMhAd4aY+0Iv7uHPMvdgN0Df8 1h+FMpMxljyMaL65Bt9TPlnVn/+/79cBmayWIJGk5tH64lAU6xdGYyOlqbbg9+5miQ 4UABMgXSkbZWQ== From: Mark Brown Date: Mon, 22 Jan 2024 20:41:53 +0000 Subject: [PATCH 3/4] arm64/fp: Clarify effect of setting an unsupported system VL Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20240122-arm64-sve-sme-doc-v1-3-3d492e45265b@kernel.org> References: <20240122-arm64-sve-sme-doc-v1-0-3d492e45265b@kernel.org> In-Reply-To: <20240122-arm64-sve-sme-doc-v1-0-3d492e45265b@kernel.org> To: Catalin Marinas , Will Deacon , Jonathan Corbet Cc: Dave Martin , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Mark Brown , Edmund Grimley-Evans X-Mailer: b4 0.13-dev-5c066 X-Developer-Signature: v=1; a=openpgp-sha256; l=2147; i=broonie@kernel.org; h=from:subject:message-id; bh=fjtGYrPLVAgmnbjt+Ekb+IEbQu2c0zwfHg/G7gZsVmI=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBlrtMiH/73f//2tkGiaJyZTf5xHRxxVBa9xFB2oZ2L zwYsEhaJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZa7TIgAKCRAk1otyXVSH0PHiB/ 9zHa9KEFYs2ugoCsm80PWrKpmYx7jbcBOAt1g3oeczKb/va6JJ8R8yS4RO+t0zjM+SgEWE2gMboGMz WfUNahqBNUYMy30d0sUCnj0ykg/ghbn/SY0Ng5wfRLG0yExhnde4OSIbdtV8MB3S22TuOgevK6y2RB NUWNljFA3h031svejBLxzIuKg+BAZJshAKtavwWDxY3N4og3h/KBeyvwhSpyPuZaVAOtZgODrcLwUX l6hTlmcn8M0E0Vwsjb9KonvrLA+FW/5yDNZVqYKSTEpbmDkZIHE4+FJpFY1ysmbj5ulodp1nN+V2Y4 9AkkJP5c4s66BXeveCA9VgM1Wv2K2x X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB The documentation for system vector length configuration does not cover all cases where unsupported values are written, tighten it up. Reported-by: Edmund Grimley-Evans Signed-off-by: Mark Brown --- Documentation/arch/arm64/sme.rst | 5 ++--- Documentation/arch/arm64/sve.rst | 5 ++--- 2 files changed, 4 insertions(+), 6 deletions(-) diff --git a/Documentation/arch/arm64/sme.rst b/Documentation/arch/arm64/sme.rst index 3133d0e91b48..ba0a5e5b2523 100644 --- a/Documentation/arch/arm64/sme.rst +++ b/Documentation/arch/arm64/sme.rst @@ -379,9 +379,8 @@ The regset data starts with struct user_za_header, containing: /proc/sys/abi/sme_default_vector_length Writing the text representation of an integer to this file sets the system - default vector length to the specified value, unless the value is greater - than the maximum vector length supported by the system in which case the - default vector length is set to that maximum. + default vector length to the specified value rounded to a supported value + using the same rules as for setting vector length via prctl(). The result can be determined by reopening the file and reading its contents. diff --git a/Documentation/arch/arm64/sve.rst b/Documentation/arch/arm64/sve.rst index b45a2da19bf1..b923727ff4b9 100644 --- a/Documentation/arch/arm64/sve.rst +++ b/Documentation/arch/arm64/sve.rst @@ -423,9 +423,8 @@ The regset data starts with struct user_sve_header, containing: /proc/sys/abi/sve_default_vector_length Writing the text representation of an integer to this file sets the system - default vector length to the specified value, unless the value is greater - than the maximum vector length supported by the system in which case the - default vector length is set to that maximum. + default vector length to the specified value rounded to a supported value + using the same rules as for setting vector length via prctl(). The result can be determined by reopening the file and reading its contents. -- 2.30.2