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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 8CB3AC43219 for ; Tue, 30 Apr 2019 12:53:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5DB3B20652 for ; Tue, 30 Apr 2019 12:53:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728087AbfD3Mxf (ORCPT ); Tue, 30 Apr 2019 08:53:35 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45340 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726166AbfD3Mxf (ORCPT ); Tue, 30 Apr 2019 08:53:35 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2CAB4307C947; Tue, 30 Apr 2019 12:53:35 +0000 (UTC) Received: from [10.36.116.17] (ovpn-116-17.ams2.redhat.com [10.36.116.17]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 81256183E2; Tue, 30 Apr 2019 12:53:32 +0000 (UTC) Subject: Re: [PATCH v2 1/7] genirq/msi: Add a new field in msi_desc to store an IOMMU cookie To: Julien Grall , linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org Cc: jason@lakedaemon.net, douliyangs@gmail.com, marc.zyngier@arm.com, robin.murphy@arm.com, miquel.raynal@bootlin.com, tglx@linutronix.de, logang@deltatee.com, bigeasy@linutronix.de, linux-rt-users@vger.kernel.org References: <20190429144428.29254-1-julien.grall@arm.com> <20190429144428.29254-2-julien.grall@arm.com> From: Auger Eric Message-ID: Date: Tue, 30 Apr 2019 14:53:31 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <20190429144428.29254-2-julien.grall@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.46]); Tue, 30 Apr 2019 12:53:35 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi On 4/29/19 4:44 PM, Julien Grall wrote: > When an MSI doorbell is located downstream of an IOMMU, it is required > to swizzle the physical address with an appropriately-mapped IOVA for any > device attached to one of our DMA ops domain. > > At the moment, the allocation of the mapping may be done when composing > the message. However, the composing may be done in non-preemtible > context while the allocation requires to be called from preemptible > context. > > A follow-up change will split the current logic in two functions > requiring to keep an IOMMU cookie per MSI. > > A new field is introduced in msi_desc to store an IOMMU cookie. As the > cookie may not be required in some configuration, the field is protected > under a new config CONFIG_IRQ_MSI_IOMMU. > > A pair of helpers has also been introduced to access the field. > > Signed-off-by: Julien Grall Besides other's comments Reviewed-by: Eric Auger Thanks Eric > > --- > Changes in v2: > - Update the commit message to use imperative mood > - Protect the field with a new config that will be selected by > IOMMU_DMA later on > - Add a set of helpers to access the new field > --- > include/linux/msi.h | 26 ++++++++++++++++++++++++++ > kernel/irq/Kconfig | 3 +++ > 2 files changed, 29 insertions(+) > > diff --git a/include/linux/msi.h b/include/linux/msi.h > index 7e9b81c3b50d..82a308c19222 100644 > --- a/include/linux/msi.h > +++ b/include/linux/msi.h > @@ -77,6 +77,9 @@ struct msi_desc { > struct device *dev; > struct msi_msg msg; > struct irq_affinity_desc *affinity; > +#ifdef CONFIG_IRQ_MSI_IOMMU > + const void *iommu_cookie; > +#endif > > union { > /* PCI MSI/X specific data */ > @@ -119,6 +122,29 @@ struct msi_desc { > #define for_each_msi_entry_safe(desc, tmp, dev) \ > list_for_each_entry_safe((desc), (tmp), dev_to_msi_list((dev)), list) > > +#ifdef CONFIG_IRQ_MSI_IOMMU > +static inline const void *msi_desc_get_iommu_cookie(struct msi_desc *desc) > +{ > + return desc->iommu_cookie; > +} > + > +static inline void msi_desc_set_iommu_cookie(struct msi_desc *desc, > + const void *iommu_cookie) > +{ > + desc->iommu_cookie = iommu_cookie; > +} > +#else > +static inline const void *msi_desc_get_iommu_cookie(struct msi_desc *desc) > +{ > + return NULL; > +} > + > +static inline void msi_desc_set_iommu_cookie(struct msi_desc *desc, > + const void *iommu_cookie) > +{ > +} > +#endif > + > #ifdef CONFIG_PCI_MSI > #define first_pci_msi_entry(pdev) first_msi_entry(&(pdev)->dev) > #define for_each_pci_msi_entry(desc, pdev) \ > diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig > index 5f3e2baefca9..8fee06625c37 100644 > --- a/kernel/irq/Kconfig > +++ b/kernel/irq/Kconfig > @@ -91,6 +91,9 @@ config GENERIC_MSI_IRQ_DOMAIN > select IRQ_DOMAIN_HIERARCHY > select GENERIC_MSI_IRQ > > +config IRQ_MSI_IOMMU > + bool > + > config HANDLE_DOMAIN_IRQ > bool > >