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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 737C1C10F14 for ; Tue, 23 Apr 2019 10:55:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4CEB0206BA for ; Tue, 23 Apr 2019 10:55:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727601AbfDWKzj (ORCPT ); Tue, 23 Apr 2019 06:55:39 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:54268 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726150AbfDWKzj (ORCPT ); Tue, 23 Apr 2019 06:55:39 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 05D7A374; Tue, 23 Apr 2019 03:55:39 -0700 (PDT) Received: from [10.37.8.239] (unknown [10.37.8.239]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5470A3F557; Tue, 23 Apr 2019 03:55:36 -0700 (PDT) Subject: Re: [PATCH 2/7] iommu/dma-iommu: Split iommu_dma_map_msi_msg in two parts To: Christoph Hellwig Cc: linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, logang@deltatee.com, douliyangs@gmail.com, miquel.raynal@bootlin.com, marc.zyngier@arm.com, jason@lakedaemon.net, tglx@linutronix.de, joro@8bytes.org, robin.murphy@arm.com, bigeasy@linutronix.de, linux-rt-users@vger.kernel.org References: <20190418172611.21561-1-julien.grall@arm.com> <20190418172611.21561-3-julien.grall@arm.com> <20190423070823.GA12114@infradead.org> From: Julien Grall Message-ID: <7af177e1-dfd9-2a91-3fd9-dfe53a6a9014@arm.com> Date: Tue, 23 Apr 2019 11:55:34 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190423070823.GA12114@infradead.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 4/23/19 8:08 AM, Christoph Hellwig wrote: > On Thu, Apr 18, 2019 at 06:26:06PM +0100, Julien Grall wrote: >> +int iommu_dma_prepare_msi(struct msi_desc *desc, phys_addr_t msi_addr) >> { >> + struct device *dev = msi_desc_to_dev(desc); >> struct iommu_domain *domain = iommu_get_domain_for_dev(dev); >> struct iommu_dma_cookie *cookie; >> unsigned long flags; >> >> + if (!domain || !domain->iova_cookie) { >> + desc->iommu_cookie = NULL; >> + return 0; >> + } >> >> cookie = domain->iova_cookie; >> >> @@ -908,10 +908,33 @@ void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg) >> * of an MSI from within an IPI handler. >> */ >> spin_lock_irqsave(&cookie->msi_lock, flags); >> + desc->iommu_cookie = iommu_dma_get_msi_page(dev, msi_addr, domain); >> spin_unlock_irqrestore(&cookie->msi_lock, flags); >> >> + return (desc->iommu_cookie) ? 0 : -ENOMEM; > > No need for the braces. Also I personally find a: > > if (!desc->iommu_cookie) > return -ENOMEM; > return 0; > > much more readable, but that might just be personal preference. I am happy either way. I will use your suggestion in the next version. Cheers, -- Julien Grall