From patchwork Mon Sep 21 16:28:32 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 263697 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=-11.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 B19CEC43468 for ; Mon, 21 Sep 2020 16:42:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6FD7123976 for ; Mon, 21 Sep 2020 16:42:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600706576; bh=TKedLSS7DQWIizRWMXwSuTi5i+cLls7C2mBLvjUlNbs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Cf1KpdBM4wXv0ic1VvzRoD7cfzHHk3B4HF9kXZUCw2KPbixKeQ5uUUlWNaoDBVuBv 3a015dj/kYuTA+huhXtWo/tk1CyvH7Prc5K5hh+Ac0i1SgJuWX7uTeUy88+BcppQIb LDmSu9rZS2lVa3hswHaklG4u54Kkm3Z99ARZB3VA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728788AbgIUQmv (ORCPT ); Mon, 21 Sep 2020 12:42:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:47106 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729066AbgIUQmt (ORCPT ); Mon, 21 Sep 2020 12:42:49 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (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 759EA238E6; Mon, 21 Sep 2020 16:42:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600706569; bh=TKedLSS7DQWIizRWMXwSuTi5i+cLls7C2mBLvjUlNbs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SWm7Zc0lYpmfkCmgl4qkufVJGugP2VMjxQRn3qqZLqqt+JFocFkby9Uvm1/PaJHur SvvHf7gwKAbCbXtMDonxF31INfaQovVwoES7elPUXdLyFI1FPTFu//kFPeGtXtoAHy cb4sTyHHfY59EIUetTR5SJf+U03A2hcu8n2uKZK8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexey Kardashevskiy , Michael Ellerman Subject: [PATCH 4.19 48/49] powerpc/dma: Fix dma_map_ops::get_required_mask Date: Mon, 21 Sep 2020 18:28:32 +0200 Message-Id: <20200921162036.776250199@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200921162034.660953761@linuxfoundation.org> References: <20200921162034.660953761@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Alexey Kardashevskiy commit 437ef802e0adc9f162a95213a3488e8646e5fc03 upstream. There are 2 problems with it: 1. "<" vs expected "<<" 2. the shift number is an IOMMU page number mask, not an address mask as the IOMMU page shift is missing. This did not hit us before f1565c24b596 ("powerpc: use the generic dma_ops_bypass mode") because we had additional code to handle bypass mask so this chunk (almost?) never executed.However there were reports that aacraid does not work with "iommu=nobypass". After f1565c24b596, aacraid (and probably others which call dma_get_required_mask() before setting the mask) was unable to enable 64bit DMA and fall back to using IOMMU which was known not to work, one of the problems is double free of an IOMMU page. This fixes DMA for aacraid, both with and without "iommu=nobypass" in the kernel command line. Verified with "stress-ng -d 4". Fixes: 6a5c7be5e484 ("powerpc: Override dma_get_required_mask by platform hook and ops") Cc: stable@vger.kernel.org # v3.2+ Signed-off-by: Alexey Kardashevskiy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200908015106.79661-1-aik@ozlabs.ru Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kernel/dma-iommu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/arch/powerpc/kernel/dma-iommu.c +++ b/arch/powerpc/kernel/dma-iommu.c @@ -100,7 +100,8 @@ static u64 dma_iommu_get_required_mask(s if (!tbl) return 0; - mask = 1ULL < (fls_long(tbl->it_offset + tbl->it_size) - 1); + mask = 1ULL << (fls_long(tbl->it_offset + tbl->it_size) + + tbl->it_page_shift - 1); mask += mask - 1; return mask;