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=-15.9 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,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 98D57C4708F for ; Tue, 1 Jun 2021 09:10:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 791CB61364 for ; Tue, 1 Jun 2021 09:10:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233408AbhFAJLl (ORCPT ); Tue, 1 Jun 2021 05:11:41 -0400 Received: from foss.arm.com ([217.140.110.172]:44508 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231139AbhFAJLh (ORCPT ); Tue, 1 Jun 2021 05:11:37 -0400 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 6E5D511D4; Tue, 1 Jun 2021 02:09:56 -0700 (PDT) Received: from [10.57.73.64] (unknown [10.57.73.64]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7A2383F73D; Tue, 1 Jun 2021 02:09:55 -0700 (PDT) Subject: Re: [PATCH] iommu: Print default strict or lazy mode at init time To: John Garry , joro@8bytes.org, will@kernel.org Cc: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, hch@lst.de References: <1622209074-37899-1-git-send-email-john.garry@huawei.com> From: Robin Murphy Message-ID: <3ee986a0-29c1-100c-c72f-360f919caf7d@arm.com> Date: Tue, 1 Jun 2021 10:09:50 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: <1622209074-37899-1-git-send-email-john.garry@huawei.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021-05-28 14:37, John Garry wrote: > As well as the default domain type, it's useful to know whether strict > or lazy mode is default for DMA domains, so add this info in a separate > print. > > Signed-off-by: John Garry > > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c > index 808ab70d5df5..f25fae62f077 100644 > --- a/drivers/iommu/iommu.c > +++ b/drivers/iommu/iommu.c > @@ -138,6 +138,11 @@ static int __init iommu_subsys_init(void) > (iommu_cmd_line & IOMMU_CMD_LINE_DMA_API) ? > "(set via kernel command line)" : ""); > > + pr_info("Default DMA domain mode: %s %s\n", Nit: I think this might be a little unclear for end-users - *I'm* not even sure whether "Default" here is meant to refer to the mode setting itself or to default domains (of DMA type). Maybe something like "DMA domain TLB invalidation policy"? Certainly it seems like a good idea to explicitly mention invalidation to correlate with the documentation of the "iommu.strict" parameter. Ack to the general idea though. Thanks, Robin. > + iommu_dma_strict ? "strict" : "lazy", > + (iommu_cmd_line & IOMMU_CMD_LINE_STRICT) ? > + "(set via kernel command line)" : ""); > + > return 0; > } > subsys_initcall(iommu_subsys_init); >