From patchwork Mon Sep 21 16:28:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "gregkh@linuxfoundation.org" X-Patchwork-Id: 309415 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 A67B6C43466 for ; Mon, 21 Sep 2020 16:47:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6B012238A1 for ; Mon, 21 Sep 2020 16:47:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600706837; bh=P03xTyf2oEsYBu/7PbrLbijGc2Igq62DU0HigGMaYcw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ISBIP0opGZiaKI2ta/03+iqdkXPDiFms2AE9tUWpyulgBvEXuyrqQausEV4ohcN1R ZJV9D3/KVhvp5pvqZGYvU+e0zU/aJND4xbv/CiaHPQ091INnoskH7OL3HlpA0/DGgS mmLOB5sAQI+uQSjiAvJRSFF3fFKoFpQxF68O3V9g= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729757AbgIUQrN (ORCPT ); Mon, 21 Sep 2020 12:47:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:53924 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729753AbgIUQrN (ORCPT ); Mon, 21 Sep 2020 12:47:13 -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 6BCF3238A1; Mon, 21 Sep 2020 16:47:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600706832; bh=P03xTyf2oEsYBu/7PbrLbijGc2Igq62DU0HigGMaYcw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=c/lHW3un3dukORWg33c+lsxu5jLTTgffUnwNKQwGm2L5Ktkh01SJMaPSriKMUcCyr ftdwquReeWb04ayA9w233UtwNufjwtD7b1cyLo3Tds9ZGkHZxM8toyW2i4LF7VZpkG eecpNv385SlvFmKrXmg8R3K7Cr+mxID+dv4VvTdg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexey Kardashevskiy , Michael Ellerman Subject: [PATCH 5.8 111/118] powerpc/dma: Fix dma_map_ops::get_required_mask Date: Mon, 21 Sep 2020 18:28:43 +0200 Message-Id: <20200921162041.541726525@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200921162036.324813383@linuxfoundation.org> References: <20200921162036.324813383@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 @@ -160,7 +160,8 @@ u64 dma_iommu_get_required_mask(struct d return bypass_mask; } - 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;