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 D78E9C27C4F for ; Thu, 13 Jun 2024 11:24:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:MIME-Version: References:In-Reply-To:Subject:Cc:To:From:Message-ID:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Fsg/Yy5/6aWhGNLFFvGSAYZdi/Si7KB/ILIOw5jSitw=; b=vWXmBZd5sTyl7I+Yt+COz0XWwi XESPtz/Y1dXAW6lBU3NS3eayBmXQqOy6ujnpepbdL9Ps5RPbmXz15THF0M0BlqWJRmVL15cSSyRPV eM3zCQeCnqxnQGTNI1dYnLqxTDFiqbjtpjk91RiD9RSkh6e+mLYmq5+WyORknRiI9CGEdiihfQoo5 LJEuJBDetHZgQURgJnK3me3kkGXmYwcSPPmyPN98Ec/nYCuAei23NcQ+jW46O2S0Ob9YAcB0ac3Xt Vuz8jxgEu49dYv2zfK5xllxfELWh7EkLmKI2AVBPlDtzJEFLcuL9qXs2Ub4xNzGqKOAjtcK+LlNJz hzTqKW8Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sHiYb-0000000GIgY-2uPa; Thu, 13 Jun 2024 11:23:53 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sHiYX-0000000GIeK-36i4 for linux-arm-kernel@lists.infradead.org; Thu, 13 Jun 2024 11:23:51 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id D27CE61A27; Thu, 13 Jun 2024 11:23:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 80EFAC2BBFC; Thu, 13 Jun 2024 11:23:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1718277828; bh=sqgBrvb1tQtLs7yqLxnsmPlbQsKBTcgqd4+WVYki8NA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=IoMHuSLZR5RB4BxswtmmHoKCuhmA8LeQyKKu7kjBWRojZcKSGvSAl3zJD70QMsHY7 GUFhpEUG/upkV7fXsNVUY+Armma8CD4dh1xu3ewwcN23nzVSGMnEn1NsXjHrI5IeJl jbGnNl3AMVn/xzd+ZPwvsNh2p274JM51VV08EMJTJA1HxKLRAr8RIiC46EDux+1J8X V8c1/ri8+BdyFnGoHvXzrIT3e3UOxqUehJKI+91zuL8MrY0WhuNC2+PwkLko2KNOFj Niu12/k+oLeM7edwHke4V6CD4rg95qw5R5WUyJUJpXSxcBHOQLNyzOVA0a6o8kEgh0 WuJMouCa/o75A== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1sHiYU-003Wgr-9U; Thu, 13 Jun 2024 12:23:46 +0100 Date: Thu, 13 Jun 2024 12:23:46 +0100 Message-ID: <86y179jdbx.wl-maz@kernel.org> From: Marc Zyngier To: Anshuman Khandual Cc: linux-arm-kernel@lists.infradead.org, mark.rutland@arm.com, ryan.roberts@arm.com, Catalin Marinas , Will Deacon , linux-kernel@vger.kernel.org Subject: Re: [PATCH] arm64/mm: Drop ESR_ELx_FSC_TYPE In-Reply-To: <20240613094538.3263536-1-anshuman.khandual@arm.com> References: <20240613094538.3263536-1-anshuman.khandual@arm.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/29.2 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: anshuman.khandual@arm.com, linux-arm-kernel@lists.infradead.org, mark.rutland@arm.com, ryan.roberts@arm.com, catalin.marinas@arm.com, will@kernel.org, linux-kernel@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240613_042349_950157_85E288BB X-CRM114-Status: GOOD ( 14.87 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, 13 Jun 2024 10:45:38 +0100, Anshuman Khandual wrote: > > Fault status codes at page table level 0, 1, 2 and 3 for access, permission > and translation faults are architecturally organized in a way, that masking > out ESR_ELx_FSC_TYPE, fetches Level 0 status code for the respective fault. > > Helpers like esr_fsc_is_[translation|permission|access_flag]_fault() mask > out ESR_ELx_FSC_TYPE before comparing against corresponding Level 0 status > code as the kernel does not yet care about the page table level, the fault > really occurred previously. > > This scheme is starting to crumble after FEAT_LPA2 when level -1 got added. > Fault status code for translation fault at level -1 is 0x2B which does not > follow ESR_ELx_FSC_TYPE, requiring esr_fsc_is_translation_fault() changes. > > This changes above helpers to compare against individual fault status code > values for each page table level and drop ESR_ELx_FSC_TYPE which is losing > its value as a common mask. I'd rather we do not drop the existing #defines, for a very self-serving reason: NV requires an implementation to synthesise fault syndromes, and these definition are extensively used to compose the syndrome information (see the NV MMU series at [1]). This is also heavily use to emulate the AT instructions (fault reporting in PAR_EL1.FST). Having additional helpers is fine. Dropping the base definitions isn't, and I'd like to avoid reintroducing them. Thanks, M. [1] http://lore.kernel.org/r/20240529145628.3272630-1-maz@kernel.org -- Without deviation from the norm, progress is not possible.