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=-8.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 38D02C3A589 for ; Tue, 20 Aug 2019 15:58:44 +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 0EC4A22DA9 for ; Tue, 20 Aug 2019 15:58:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="g0uEFPir"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="nAlUc1Gk" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0EC4A22DA9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org 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-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=2CmaiFgvV4tTlYrYZ06GYY9lhthIIRuNGXSSV/zMxbM=; b=g0uEFPirMzRCAa XiWC8anJctxgxmxfG8bgP0UQO/rqbRrQNia9WpKs2+M2HBrec41ZMlVnCZww9wD1RBqZ9DDYYMEaq Dlc6NluHF6lJkZw6x3gOm90FZU727Z7clrJHfZRWwKbp5S1/g2rlBfXnH4lCXAnMdaBeh2vGSRywA PyYyKuYco75WOuLy1DVYl8LyGO3rFddVoaQLzLqAP066MCSje4ESDXLmXzgL88CDqlsN1atBwtmso F3Bafg91mnnFnP7IDb1P8c0fvRimGW+OXsxEXX+Svb6E+21VXjQyCZqb+CYVdBJ3ERm9C9YrvPJRN /dZoLX9RyyVp/v7SrZ0w==; 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 1i06Wx-0000BH-BB; Tue, 20 Aug 2019 15:58:43 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1i06Wi-0008NU-AO for linux-arm-kernel@lists.infradead.org; Tue, 20 Aug 2019 15:58:29 +0000 Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C6A1022CF7; Tue, 20 Aug 2019 15:58:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566316707; bh=dDXHA5bU4rB/VugoM/y+S4USn6RYgLcSxFjkdH7xqZg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=nAlUc1GkL0o2MiZB9ygu3+rAl7z9MXqOto5rybXrVg7AXjPeph788PYAKLdjE8BCj OfdOMzy2XmKYQMSg5+QiFfjJgbLZxxYicfz5+YMO5ZNMS4aPGYE3Fs6ouNnlYxPJ7d zGmDLsy1TXr2uf4OiOpILnZ92P5x388+5f7mUDjw= Date: Tue, 20 Aug 2019 16:58:24 +0100 From: Will Deacon To: Robin Murphy Subject: Re: [PATCH 4/4] iommu/io-pgtable-arm: Prepare for TTBR1 usage Message-ID: <20190820155823.ptn2rfvnmkd4v632@willie-the-truck> References: <6596469d5fa1e918145fdd4e6b1a3ad67f7cde2e.1566238530.git.robin.murphy@arm.com> <20190820103048.xacfbtn5o4wermhi@willie-the-truck> <469dc66a-2532-5f7f-cd8d-3fe13f6c279a@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <469dc66a-2532-5f7f-cd8d-3fe13f6c279a@arm.com> User-Agent: NeoMutt/20170113 (1.7.2) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190820_085828_432374_2538A6D4 X-CRM114-Status: GOOD ( 25.73 ) 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-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Aug 20, 2019 at 03:51:45PM +0100, Robin Murphy wrote: > 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 :/ Right, and I'd rather not push stuff into the caller for the common case. It's not exactly onerous to support this in io-pgtable. It's also why I'd still like to keep the EPDx in there, because the callers that care can rewrite the stuff, but at least we provided a default. > 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. That sounds pretty theoretical to me at the moment. Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel