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 X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B8458C3A589 for ; Tue, 20 Aug 2019 14:51:56 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 893D922CE3 for ; Tue, 20 Aug 2019 14:51:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="OjkgJn35" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 893D922CE3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=ID4NBYyE7HLkFm9D9Eq4Nj4bpMUeBAD0KGe+SG6SRhs=; b=OjkgJn3567+NRfWiLiFmDBGfa p7cO6OvNPhgowoCt0xV7Apo9EkPDTWYAcbfDaiUo3MYQ2O8lKrq5o8lpOGNrmSgbrF5w3rhep+zMG +fokB6nEBWkch6SGWirzGOCIV/4yOF2004GLlWKbdBg9unKh2b1zZvfCMpxGnEcmi81GcYuvPU4r+ y/RNxo2zewDBn0WddVUZjevIKats5WeAGwdF5/b6cyC1r0ckj1AJEQxww+pVUO4W2HAllVISfrLyl aAQRYoJ9T8fAc2roujVpu/NBAHHh8Zf7a6hbMm7ky8D+wI/req9+wohTusEbXUM1ICMawCE34wBfV zoAOIgEYw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i05UI-0000mK-OV; Tue, 20 Aug 2019 14:51:54 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i05UF-0000lv-Fm for linux-arm-kernel@lists.infradead.org; Tue, 20 Aug 2019 14:51:52 +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 E3D9A28; Tue, 20 Aug 2019 07:51:46 -0700 (PDT) Received: from [10.1.197.57] (e110467-lin.cambridge.arm.com [10.1.197.57]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 1977D3F246; Tue, 20 Aug 2019 07:51:45 -0700 (PDT) Subject: Re: [PATCH 4/4] iommu/io-pgtable-arm: Prepare for TTBR1 usage To: Will Deacon References: <6596469d5fa1e918145fdd4e6b1a3ad67f7cde2e.1566238530.git.robin.murphy@arm.com> <20190820103048.xacfbtn5o4wermhi@willie-the-truck> From: Robin Murphy Message-ID: <469dc66a-2532-5f7f-cd8d-3fe13f6c279a@arm.com> Date: Tue, 20 Aug 2019 15:51:45 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190820103048.xacfbtn5o4wermhi@willie-the-truck> Content-Language: en-GB X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190820_075151_572795_037FB2F8 X-CRM114-Status: GOOD ( 21.85 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: robdclark@gmail.com, joro@8bytes.org, jcrouse@codeaurora.org, iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 20/08/2019 11:30, Will Deacon wrote: > On Mon, Aug 19, 2019 at 07:19:31PM +0100, Robin Murphy wrote: >> Now that callers are free to use a given table for TTBR1 if they wish >> (all they need do is shift the provided attributes when constructing >> their final TCR value), the only remaining impediment is the address >> validation on map/unmap. The fact that the LPAE address space split is >> symmetric makes this easy to accommodate - by simplifying the current >> range checks into explicit tests that address bits above IAS are all >> zero, it then follows straightforwardly to add the inverse test to >> allow the all-ones case as well. >> >> Signed-off-by: Robin Murphy >> --- >> drivers/iommu/io-pgtable-arm.c | 7 ++++--- >> 1 file changed, 4 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c >> index 09cb20671fbb..f39c50356351 100644 >> --- a/drivers/iommu/io-pgtable-arm.c >> +++ b/drivers/iommu/io-pgtable-arm.c >> @@ -475,13 +475,13 @@ static int arm_lpae_map(struct io_pgtable_ops *ops, unsigned long iova, >> arm_lpae_iopte *ptep = data->pgd; >> int ret, lvl = ARM_LPAE_START_LVL(data); >> arm_lpae_iopte prot; >> + long iaext = (long)iova >> data->iop.cfg.ias; >> >> /* If no access, then nothing to do */ >> if (!(iommu_prot & (IOMMU_READ | IOMMU_WRITE))) >> return 0; >> >> - if (WARN_ON(iova >= (1ULL << data->iop.cfg.ias) || >> - paddr >= (1ULL << data->iop.cfg.oas))) >> + if (WARN_ON((iaext && ~iaext) || paddr >> data->iop.cfg.oas)) > > I had to read that '&&' twice, but I see what you're doing now :) > >> return -ERANGE; > > This doesn't seem sufficient to prevent a mixture of TTBR1 and TTBR0 > addresses from being mapped in the same TTBR. Perhaps we need a quirk for > TTBR1, which could then take care of setting EPDx appropriately? Right, that's the one downside of going for the minimalist "io-pgtable doesn't even have to know" approach. On reflection, though, in that paradigm it should probably be the caller's responsibility to convert TTBR1 addresses to preserve the "as if TTBR0" illusion anyway :/ The advantage of not having a quirk is that it allows split address spaces to fit more closely with the aux_domain idea, i.e. we could allocate and initialise a domain without having to assume, or even care, whether it will end up attached as a primary or aux domain. It *might* even be potentially useful to have a domain attached to TTBR0 of one device's context and TTBR1 of another's at the same time, although that's pretty niche. Robin. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel