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 F3B35F4F1 for ; Mon, 21 Jul 2025 10:52:23 +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=1753095146; cv=none; b=Ec5HzEFdqNGJyIDQiR/4OX47JrrpXe30oMH1aNk1tshdsnj5VBafBImV4An13QMyvzyQt7Hb4oFZ4ZT2GDfbdxtn8zAGxYcsBvpC9iyHK9Ik2PC5KBI65FrVS2ZNq0CtGOSnZt8zwW2Ys+2a8N4aN8uvjyC2JTKD2c6N/dM/8xc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753095146; c=relaxed/simple; bh=tA+alFVpzutOzzui/v9OIbhNjy3kmj/gWBZWXWUzNBw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=AQrlild3FdBE3mL5RSWny88Mzs/yoTNePptbmpkjwgMGh6rJd7Hh2PSO6hY1bQp7JOZ99xkSPnwrrX8+YWeNBaK5JWhxDDg0Rf6mxh2cpuMfhV3dBaw9XmMqqVexhgJ4YCEwjIUChrFMz8DTct0Qgi25I/+jrxVq4MA2jRPFdK4= 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; 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 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 5E000153B; Mon, 21 Jul 2025 03:52:17 -0700 (PDT) Received: from J2N7QTR9R3 (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 4D72B3F59E; Mon, 21 Jul 2025 03:52:21 -0700 (PDT) Date: Mon, 21 Jul 2025 11:52:16 +0100 From: Mark Rutland To: Yeoreum Yun Cc: catalin.marinas@arm.com, will@kernel.org, broonie@kernel.org, oliver.upton@linux.dev, ardb@kernel.org, frederic@kernel.org, james.morse@arm.com, joey.gouly@arm.com, scott@os.amperecomputing.com, maz@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 3/7] arm64/Kconfig: add LSUI Kconfig Message-ID: References: <20250721083618.2743569-1-yeoreum.yun@arm.com> <20250721083618.2743569-4-yeoreum.yun@arm.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: <20250721083618.2743569-4-yeoreum.yun@arm.com> On Mon, Jul 21, 2025 at 09:36:14AM +0100, Yeoreum Yun wrote: > Since Armv9.6, FEAT_LSUI supplies the load/store instructions for > previleged level to access to access user memory without clearing > PSTATE.PAN bit. > It's enough to add CONFIG_AS_HAS_LSUI only because the code for LUSI uses Nit: s/LUSI/LSUI/ > indiviual `.arch_extension` entries. Nit: s/indiviual/individual/ > > Signed-off-by: Yeoreum Yun > --- > arch/arm64/Kconfig | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index 393d71124f5d..c0beb44ed5b8 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -2238,6 +2238,15 @@ config ARM64_GCS > > endmenu # "v9.4 architectural features" > > +config AS_HAS_LSUI > + def_bool $(as-instr,.arch_extension lsui) > + help > + Unprivileged Load Store is an extension to introduce unprivileged > + variants of load and store instructions so that clearing PSTATE.PAN > + is never required in privileged mode. > + This feature is available with clang version 20 and later and not yet > + supported by gcc. I don't think we need to describe the feature in detail for the AS_HAS_* config symbol; I think all we need to say is: Supported by LLVM 20 and later, not yet supported by GNU AS. Otherwise this looks fine. Mark. > + > config ARM64_SVE > bool "ARM Scalable Vector Extension support" > default y > -- > LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7} > >