From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 141C5C433FE for ; Wed, 23 Nov 2022 13:28:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To: Subject:MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=FUd0TxgzjTjw5LAGd7BuVtg1+0pEZc3GH8i9Qnfzbks=; b=jp5TfKqCMsYu45 l1jWmC64W0u6QYZgAwkwpKHiKwoK5w7KbMYY3wgWEunU/qfsE5TqcPiENRX29N3UPHGWY35huk3qD Ycvecu2ZXMxmnWjI8MKVgyQv8U9gZwLS7TbWuH4nBCmbgRiuN8dSuI1nMpDcUW6gQkVsjmHdGczYR xRXiOEFdIn7SPjzSBIMR543CkVlusQXCqjwPMXwtuatmnj3ygJIRTZNv217bdZPLAFoZltwHsMc86 Wvjt0Lg5iinUB+9frpiVi3HEtGjnfpi21vYUS7bIasMStVUj8HLmsSc5iLa5kC/fJkg22sXkQMKhH Rmx92thh11mDie7UVPJQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oxplu-00HDep-Lh; Wed, 23 Nov 2022 13:26:38 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oxplm-00HDZZ-02 for linux-arm-kernel@lists.infradead.org; Wed, 23 Nov 2022 13:26:31 +0000 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 78F001FB; Wed, 23 Nov 2022 05:26:31 -0800 (PST) Received: from [192.168.0.110] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3005A3F73D; Wed, 23 Nov 2022 05:26:22 -0800 (PST) Message-ID: <1b4e77d3-555e-41e5-2511-21f20a76ddb2@arm.com> Date: Wed, 23 Nov 2022 18:56:19 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.2.2 Subject: Re: [PATCH] arm64: booting: Require placement within 48-bit addressable memory Content-Language: en-US To: Ard Biesheuvel , linux-arm-kernel@lists.infradead.org Cc: will@kernel.org, catalin.marinas@arm.com, mark.rutland@arm.com References: <20221122170249.2453853-1-ardb@kernel.org> From: Anshuman Khandual In-Reply-To: <20221122170249.2453853-1-ardb@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221123_052630_139209_DAB4AA3F X-CRM114-Status: GOOD ( 19.60 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 11/22/22 22:32, Ard Biesheuvel wrote: > Some configurations (i.e., 64k + LVA/LPA) can tolerate a physical > placement of the kernel image outside of the 48-bit addressable region, > but given that the loader has no way of knowing whether or not the image > in question supports LVA/LPA, it currently has no choice but to place it > below the 48-bit mark. > > Once we add support for LPA2, which allows 52-bit physical and virtual > addressing when using 4k or 16k pages, but in way that relies on > increasing the number of paging levels, there will be more variety in > the configurations that may or may not support this. > > So redefine bit #3 in the Image header as 'must be placed within 48-bit > addressable memory', as this is the current de facto meaning. > > Signed-off-by: Ard Biesheuvel > --- Regardless of possible vmlinux beyond 48 bits physical address discussion, this patch looks good, and complete in itself. Reviewed-by: Anshuman Khandual > Documentation/arm64/booting.rst | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/Documentation/arm64/booting.rst b/Documentation/arm64/booting.rst > index 8c324ad638de2b27..5a764fabfea821f0 100644 > --- a/Documentation/arm64/booting.rst > +++ b/Documentation/arm64/booting.rst > @@ -121,8 +121,9 @@ Header notes: > to the base of DRAM, since memory below it is not > accessible via the linear mapping > 1 > - 2MB aligned base may be anywhere in physical > - memory > + 2MB aligned base such that all image_size bytes > + counted from the start of the image are within > + the 48-bit addressable range of physical memory > Bits 4-63 Reserved. > ============= =============================================================== > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel