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=-15.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 51537C433E0 for ; Fri, 22 Jan 2021 14:43:25 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 EA1C423444 for ; Fri, 22 Jan 2021 14:43:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EA1C423444 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+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=merlin.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=SPTbBy5xhqXBEKctAmPrvvuoix0fQkQ4bEexyxDpv28=; b=V4Z9HfKRKHIhi4amS0nZIvvn+ WFUGKbZ1NX0anqgbO4WXIK/6MMjbPoZiV3wnul7JN6Elg5/XEALni5GfdD+Gohbyis+hVhkgPQH/b rtRCUJB+p2GeN7+zz0xurxRQh0XYESDy6b9fAa5xUHfIMcklCH+zl/GpUJOG2GAyXnQ5Wmql+tXdj bE6O0d9zFK1XnhD5s4+tiPbXCogaz/64woO3HU1z8rreXCVD9/+moSP2eXNQrFcsbb4b9pvtpZJWn MrDuhcDRsJyPpcRDfSqIF3Sficgd37gXHlpJ2gVc57omWzReIVmM7y4u4zu816+a4jwuY8UpZYhFp WyPrfWTWQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l2xdb-0000mt-CZ; Fri, 22 Jan 2021 14:42:11 +0000 Received: from foss.arm.com ([217.140.110.172]) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l2xdY-0000m3-CE for linux-arm-kernel@lists.infradead.org; Fri, 22 Jan 2021 14:42:09 +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 DB90D11B3; Fri, 22 Jan 2021 06:42:07 -0800 (PST) Received: from [10.57.39.58] (unknown [10.57.39.58]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 1B9853F66E; Fri, 22 Jan 2021 06:42:05 -0800 (PST) Subject: Re: [PATCH v2] ACPI/IORT: Do not blindly trust DMA masks from firmware To: Moritz Fischer , lorenzo.pieralisi@arm.com References: <20210122012419.95010-1-mdf@kernel.org> From: Robin Murphy Message-ID: Date: Fri, 22 Jan 2021 14:42:05 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:78.0) Gecko/20100101 Thunderbird/78.6.1 MIME-Version: 1.0 In-Reply-To: <20210122012419.95010-1-mdf@kernel.org> Content-Language: en-GB X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210122_094208_506950_6808D85E X-CRM114-Status: GOOD ( 25.72 ) 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: guohanjun@huawei.com, rjw@rjwysocki.net, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, moritzf@google.com, sudeep.holla@arm.com, will@kernel.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+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2021-01-22 01:24, Moritz Fischer wrote: > Address issue observed on real world system with suboptimal IORT table > where DMA masks of PCI devices would get set to 0 as result. > > iort_dma_setup() would query the root complex'/named component IORT > entry for a DMA mask, and use that over the one the device has been > configured with earlier. > > Ideally we want to use the minimum mask of what the IORT contains for > the root complex and what the device was configured with. > > Fixes: 5ac65e8c8941 ("ACPI/IORT: Support address size limit for root complexes") > Signed-off-by: Moritz Fischer > --- > > Changes from v1: > - Changed warning to FW_BUG > - Warn for both Named Component or Root Complex > - Replaced min_not_zero() with min() > > --- > drivers/acpi/arm64/iort.c | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) > > diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c > index d4eac6d7e9fb..2494138a6905 100644 > --- a/drivers/acpi/arm64/iort.c > +++ b/drivers/acpi/arm64/iort.c > @@ -1107,6 +1107,11 @@ static int nc_dma_get_range(struct device *dev, u64 *size) > > ncomp = (struct acpi_iort_named_component *)node->node_data; > > + if (!ncomp->memory_address_limit) { > + pr_warn(FW_BUG "Named component missing memory address limit\n"); > + return -EINVAL; > + } > + > *size = ncomp->memory_address_limit >= 64 ? U64_MAX : > 1ULL<memory_address_limit; > > @@ -1126,6 +1131,11 @@ static int rc_dma_get_range(struct device *dev, u64 *size) > > rc = (struct acpi_iort_root_complex *)node->node_data; > > + if (!rc->memory_address_limit) { > + pr_warn(FW_BUG "Root complex missing memory address limit\n"); > + return -EINVAL; > + } > + > *size = rc->memory_address_limit >= 64 ? U64_MAX : > 1ULL<memory_address_limit; > > @@ -1173,8 +1183,8 @@ void iort_dma_setup(struct device *dev, u64 *dma_addr, u64 *dma_size) > end = dmaaddr + size - 1; > mask = DMA_BIT_MASK(ilog2(end) + 1); > dev->bus_dma_limit = end; > - dev->coherent_dma_mask = mask; > - *dev->dma_mask = mask; > + dev->coherent_dma_mask = min(dev->coherent_dma_mask, mask); > + *dev->dma_mask = min(*dev->dma_mask, mask); Oops, I got so distracted by the "not_zero" aspect in v1 that I ended up thinking purely about smaller-than-default masks, but of course this *does* matter the other way round. And it is what we've always done on the DT side, so at least it makes us consistent. FWIW I've already started writing up a patch to kill off this bit entirely, but either way we still can't meaningfully interpret a supposed DMA limit of 0 bits in a table describing DMA-capable devices, so for this patch as a fix, Reviewed-by: Robin Murphy Thanks, Robin. > } > > *dma_addr = dmaaddr; > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel