From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 2E6F338D3F2 for ; Fri, 7 Aug 2026 16:55:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786121728; cv=none; b=NlB4y+9MA6p/4gmvbj4u8O09g5YQvUHmLm3dn9XrM7qYzRr64KDxNsq3VHeMQlnsZAwUu1jYydoSLN1JKoBc91Z/BNyPQx7ZdhlblyFQv1XySnl6UQf1+ojMAQAlzBNroyhcU6vi29e9t+yyFToFF8QstHKKZH2kRnj3Kl9ozrU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786121728; c=relaxed/simple; bh=ocxdMUJvDaa1h9TOR1Asprph0tJoS9L74P7zEU+jrf8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=mKXYTclM9nXW0l8fJFqZeuXdJnp8gufLCUwZXffa0TWf3wmaVG8UZU2gnobkXk+UWKqJQh4n7V4O8VuMQlNAFxw83aR/j3h4+4dz0hZcsGYi9RXfluSFSypTaWveqC4mJoULsBGzXJrH6ddgj1m4mJOqTisS2CV5uBy0JzxcNPQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=WCvUPegG; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="WCvUPegG" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 227AB1516; Fri, 7 Aug 2026 09:55:21 -0700 (PDT) Received: from arm.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 937A23F9A2; Fri, 7 Aug 2026 09:55:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1786121725; bh=ocxdMUJvDaa1h9TOR1Asprph0tJoS9L74P7zEU+jrf8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=WCvUPegGsA6lD2HKnUy6cU1uE2kJ3giH6Qmh+KRLtT53CH+OMVUJx8c/uSF4nMFwR PwgaTc96uHHQyUqNeJaHd79zLJQcqq9GNwvY0x99GAU27bCeMQWNfNRaymXyaqUoyD alBv5bOrjdzld6pPlUxr3zSrinCgcPvqcO+VzMVQ= Date: Fri, 7 Aug 2026 17:55:17 +0100 From: Catalin Marinas To: Qinxin Xia Cc: will@kernel.org, anshuman.khandual@arm.com, BenNiu@meta.com, robin.murphy@arm.com, xiqi2@huawei.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linuxarm@huawei.com, wangzhou1@hisilicon.com, sunnanyong@huawei.com, prime.zeng@hisilicon.com Subject: Re: [PATCH] arm64: uaccess: Optimize copy_to/from_user with LSUI extension Message-ID: References: <20260805035251.2813306-1-xiaqinxin@huawei.com> 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=us-ascii Content-Disposition: inline In-Reply-To: <20260805035251.2813306-1-xiaqinxin@huawei.com> On Wed, Aug 05, 2026 at 11:52:51AM +0800, Qinxin Xia wrote: > Add support for the ARMv9.6/LSUI (Load/Store Unprivileged Immediate) > extension to optimize copy_from_user operations. The implementation > uses the alternative mechanism to select between the standard unprivileged > load-pair sequence and the new ldtp/sttp instruction at runtime based on > hardware capability. That's all good but do you have any numbers to back the change up? -- Catalin