From patchwork Mon Sep 11 11:57:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robin Murphy X-Patchwork-Id: 13379236 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 687D1EE7FF4 for ; Mon, 11 Sep 2023 11:57:44 +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:MIME-Version:Message-Id:Date:Subject:Cc :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=kemtPPxU0gyZzVoXRdjonaT6Oid0WLWq6g6OSKUGXxg=; b=im8qMLV3RWvyjl uepFK0oHdaI9awX4T2GlgNNf9PVO2ElrG30H5dGmpfs/7k6fZiMBmUAchDy3mq7pdFXME07ZDuWv4 FjNUOqoe8y/Ve+iqMcP5UAg75XFN+uPgzNnBp5ETf8sKDdbIcjSwr1KVygSIA+Rc4OC0q1y/qVc3j nVq3bQsjFYQcK3Ygc6ADQwr/uwMXnKYhohzVuTT5M/lULAb+j8hhwEcqT4d5niI7PGBlkePh1L4ZZ KzYi/ZWxgPT0mfvXx9OpzO0t8Ezw36a3M7W6hozvES5OzCaWL/My/kpgW6VjWEvYs1WpusHf+Byhb X7G2YR33IOpVy5A356IQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qffXd-000QKM-1g; Mon, 11 Sep 2023 11:57:21 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qffXZ-000QJ1-24 for linux-arm-kernel@lists.infradead.org; Mon, 11 Sep 2023 11:57:19 +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 0C0A2D75; Mon, 11 Sep 2023 04:57:49 -0700 (PDT) Received: from e121345-lin.cambridge.arm.com (e121345-lin.cambridge.arm.com [10.1.196.40]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id ECF4E3F67D; Mon, 11 Sep 2023 04:57:10 -0700 (PDT) From: Robin Murphy To: will@kernel.org, joro@8bytes.org Cc: iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org, eahariha@linux.microsoft.com, Rui Zhu Subject: [PATCH] iommu/arm-smmu-v3: Avoid constructing invalid range commands Date: Mon, 11 Sep 2023 12:57:04 +0100 Message-Id: X-Mailer: git-send-email 2.39.2.101.g768bb238c484.dirty MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230911_045717_750881_0C60488E X-CRM114-Status: GOOD ( 12.39 ) 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 Although io-pgtable's non-leaf invalidations are always for full tables, I missed that SVA also uses non-leaf invalidations, while being at the mercy of whatever range the MMU notifier throws at it. This means it definitely wants the previous TTL fix as well, since it also doesn't know exactly which leaf level(s) may need invalidating, but it can also give us less-aligned ranges wherein certain corners may lead to building an invalid command where TTL, Num and Scale are all 0. It should be fine to handle this by over-invalidating an extra page, since falling back to a non-range command opens up a whole can of errata-flavoured worms. Fixes: 6833b8f2e199 ("iommu/arm-smmu-v3: Set TTL invalidation hint better") Reported-by: Rui Zhu Signed-off-by: Robin Murphy --- Proper resend of previous inline patch[1], now based on 6.6-rc1. [1] https://lore.kernel.org/linux-iommu/280d0be7-7d41-ed78-bf4b-3db6c0076e22@arm.com/ drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c index e82bf1c449a3..bd0a596f9863 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -1895,18 +1895,23 @@ static void __arm_smmu_tlb_inv_range(struct arm_smmu_cmdq_ent *cmd, /* Get the leaf page size */ tg = __ffs(smmu_domain->domain.pgsize_bitmap); + num_pages = size >> tg; + /* Convert page size of 12,14,16 (log2) to 1,2,3 */ cmd->tlbi.tg = (tg - 10) / 2; /* - * Determine what level the granule is at. For non-leaf, io-pgtable - * assumes .tlb_flush_walk can invalidate multiple levels at once, - * so ignore the nominal last-level granule and leave TTL=0. + * Determine what level the granule is at. For non-leaf, both + * io-pgtable and SVA pass a nominal last-level granule because + * they don't know what level(s) actually apply, so ignore that + * and leave TTL=0. However for various errata reasons we still + * want to use a range command, so avoid the SVA corner case + * where both scale and num could be 0 as well. */ if (cmd->tlbi.leaf) cmd->tlbi.ttl = 4 - ((ilog2(granule) - 3) / (tg - 3)); - - num_pages = size >> tg; + else if ((num_pages & CMDQ_TLBI_RANGE_NUM_MAX) == 1) + num_pages++; } cmds.num = 0;