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=-15.3 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,URIBL_BLOCKED, USER_AGENT_SANE_1 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 D7DB5C433E0 for ; Fri, 26 Mar 2021 01:03:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A9CAB61A1D for ; Fri, 26 Mar 2021 01:03:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230006AbhCZBDX (ORCPT ); Thu, 25 Mar 2021 21:03:23 -0400 Received: from mga04.intel.com ([192.55.52.120]:22628 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229854AbhCZBCx (ORCPT ); Thu, 25 Mar 2021 21:02:53 -0400 IronPort-SDR: DaGmn5RlIn0/dsj3Q1EaDJ8S3K3bgS+XhLo8TeISuPufzMe9s2l10dfTZhFpG/FR3Ysb5sGg1t KCyASR91apSQ== X-IronPort-AV: E=McAfee;i="6000,8403,9934"; a="188765481" X-IronPort-AV: E=Sophos;i="5.81,278,1610438400"; d="scan'208";a="188765481" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Mar 2021 18:02:53 -0700 IronPort-SDR: UDjVUON9MNVL2rohRWqpB9EM7W7/zF4vDcaB4PowV6aLek7/WP4/rjNZWtDjs4gYTRNHM2jka3 JoITW8peb0vw== X-IronPort-AV: E=Sophos;i="5.81,278,1610438400"; d="scan'208";a="525855122" Received: from meghadey-mobl1.amr.corp.intel.com (HELO [10.209.174.55]) ([10.209.174.55]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Mar 2021 18:02:50 -0700 Subject: Re: [Patch V2 13/13] genirq/msi: Provide helpers to return Linux IRQ/dev_msi hw IRQ number To: Marc Zyngier Cc: tglx@linutronix.de, linux-kernel@vger.kernel.org, dave.jiang@intel.com, ashok.raj@intel.com, kevin.tian@intel.com, dwmw@amazon.co.uk, x86@kernel.org, tony.luck@intel.com, dan.j.williams@intel.com, jgg@mellanox.com, kvm@vger.kernel.org, iommu@lists.linux-foundation.org, alex.williamson@redhat.com, bhelgaas@google.com, linux-pci@vger.kernel.org, baolu.lu@linux.intel.com, ravi.v.shankar@intel.com References: <1614370277-23235-1-git-send-email-megha.dey@intel.com> <1614370277-23235-14-git-send-email-megha.dey@intel.com> <87y2ebqfw5.wl-maz@kernel.org> From: "Dey, Megha" Message-ID: <5bed6fea-32e1-d909-0a5c-439d0f0a7dfe@intel.com> Date: Thu, 25 Mar 2021 18:02:43 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: <87y2ebqfw5.wl-maz@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Hi Marc, On 3/25/2021 10:53 AM, Marc Zyngier wrote: > On Fri, 26 Feb 2021 20:11:17 +0000, > Megha Dey wrote: >> From: Dave Jiang >> >> Add new helpers to get the Linux IRQ number and device specific index >> for given device-relative vector so that the drivers don't need to >> allocate their own arrays to keep track of the vectors and hwirq for >> the multi vector device MSI case. >> >> Reviewed-by: Tony Luck >> Signed-off-by: Dave Jiang >> Signed-off-by: Megha Dey >> --- >> include/linux/msi.h | 2 ++ >> kernel/irq/msi.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ >> 2 files changed, 46 insertions(+) >> >> diff --git a/include/linux/msi.h b/include/linux/msi.h >> index 24abec0..d60a6ba 100644 >> --- a/include/linux/msi.h >> +++ b/include/linux/msi.h >> @@ -451,6 +451,8 @@ struct irq_domain *platform_msi_create_irq_domain(struct fwnode_handle *fwnode, >> int platform_msi_domain_alloc_irqs(struct device *dev, unsigned int nvec, >> irq_write_msi_msg_t write_msi_msg); >> void platform_msi_domain_free_irqs(struct device *dev); >> +int msi_irq_vector(struct device *dev, unsigned int nr); >> +int dev_msi_hwirq(struct device *dev, unsigned int nr); >> >> /* When an MSI domain is used as an intermediate domain */ >> int msi_domain_prepare_irqs(struct irq_domain *domain, struct device *dev, >> diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c >> index 047b59d..f2a8f55 100644 >> --- a/kernel/irq/msi.c >> +++ b/kernel/irq/msi.c >> @@ -581,4 +581,48 @@ struct msi_domain_info *msi_get_domain_info(struct irq_domain *domain) >> return (struct msi_domain_info *)domain->host_data; >> } >> >> +/** >> + * msi_irq_vector - Get the Linux IRQ number of a device vector >> + * @dev: device to operate on >> + * @nr: device-relative interrupt vector index (0-based). >> + * >> + * Returns the Linux IRQ number of a device vector. >> + */ >> +int msi_irq_vector(struct device *dev, unsigned int nr) >> +{ >> + struct msi_desc *entry; >> + int i = 0; >> + >> + for_each_msi_entry(entry, dev) { >> + if (i == nr) >> + return entry->irq; >> + i++; > This obviously doesn't work with Multi-MSI, does it? This API is only for devices that support device MSI interrupts. They follow MSI-x format and don't support multi MSI (part of MSI). Not sure if I am missing something here, can you please let me know? > >> + } >> + WARN_ON_ONCE(1); >> + return -EINVAL; >> +} >> +EXPORT_SYMBOL_GPL(msi_irq_vector); >> + >> +/** >> + * dev_msi_hwirq - Get the device MSI hw IRQ number of a device vector >> + * @dev: device to operate on >> + * @nr: device-relative interrupt vector index (0-based). >> + * >> + * Return the dev_msi hw IRQ number of a device vector. >> + */ >> +int dev_msi_hwirq(struct device *dev, unsigned int nr) >> +{ >> + struct msi_desc *entry; >> + int i = 0; >> + >> + for_each_msi_entry(entry, dev) { >> + if (i == nr) >> + return entry->device_msi.hwirq; >> + i++; >> + } >> + WARN_ON_ONCE(1); >> + return -EINVAL; >> +} >> +EXPORT_SYMBOL_GPL(dev_msi_hwirq); >> + >> #endif /* CONFIG_GENERIC_MSI_IRQ_DOMAIN */ > And what uses these helpers?] These helpers are to be used by a driver series(Intel's IDXD driver) which is currently stuck due to VFIO refactoring. > > Thanks, > > M. >