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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B81C1C433EF for ; Tue, 8 Feb 2022 04:39:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346968AbiBHEjt (ORCPT ); Mon, 7 Feb 2022 23:39:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53844 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234353AbiBHEjq (ORCPT ); Mon, 7 Feb 2022 23:39:46 -0500 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D5DF7C0401DC for ; Mon, 7 Feb 2022 20:39:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1644295185; x=1675831185; h=message-id:date:mime-version:cc:subject:to:references: from:in-reply-to:content-transfer-encoding; bh=FB5zW1A6N8AXgDD9DV4LEXmGsNGVLpUJmNLzebZDg1k=; b=bCeefMrd/8i8v2a/Cu/any5vYQjgFrGZZgulER4p1yjgLVcerht/6MFH DWW2F6KTkfJH/m/c6+c8ZPqVs7OrdqBMsbjP5/aZl0SDgKAuglhf3iXcH qQOO/WE3Due24WA+M3CQERf0xcCStkbH6qQ8bqxEmsD+sAOPBzRha0sWl 9auBT1ZrrMu6YdUYcmg2hSQwajmNTnOJkBsAbqd+Klddxsl8a7oKUzACU OuPwxZI4w7IDWptThbK0cxQhdiIj6Ix/+4nuKNScoFlzF4nu31wcXmJ/0 MclyOHIJu/jm7ejhnJlcEQB89w5zaEpEzvMTQT0d5BkXifUog5FMyiyuk w==; X-IronPort-AV: E=McAfee;i="6200,9189,10251"; a="229517963" X-IronPort-AV: E=Sophos;i="5.88,351,1635231600"; d="scan'208";a="229517963" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Feb 2022 20:39:45 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,351,1635231600"; d="scan'208";a="677986757" Received: from allen-box.sh.intel.com (HELO [10.239.159.118]) ([10.239.159.118]) by fmsmga001.fm.intel.com with ESMTP; 07 Feb 2022 20:39:43 -0800 Message-ID: <762360b8-57ca-ab48-c454-25b9c0aec5de@linux.intel.com> Date: Tue, 8 Feb 2022 12:38:32 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Cc: baolu.lu@linux.intel.com, Joerg Roedel , Kevin Tian , Ashok Raj , Liu Yi L , Jacob Pan , Robin Murphy , Jason Gunthorpe , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v1 07/10] iommu/vt-d: Use an xarray for global device_domain_info Content-Language: en-US To: Christoph Hellwig References: <20220207064142.1092846-1-baolu.lu@linux.intel.com> <20220207064142.1092846-8-baolu.lu@linux.intel.com> <20220207071420.GG23941@lst.de> From: Lu Baolu In-Reply-To: <20220207071420.GG23941@lst.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/7/22 3:14 PM, Christoph Hellwig wrote: >> + #define DEVI_IDX(seg, bus, devfn) ((((u16)(seg)) << 16) | PCI_DEVID(bus, devfn)) > > Please turn this into an real function. Sure. >> /* >> - * Iterate over elements in device_domain_list and call the specified >> + * Iterate over elements in device_domain_array and call the specified >> * callback @fn against each element. >> */ >> int for_each_device_domain(int (*fn)(struct device_domain_info *info, >> void *data), void *data) >> { >> struct device_domain_info *info; >> + unsigned long index; >> + int ret = 0; >> >> + rcu_read_lock(); >> + xa_for_each(&device_domain_array, index, info) { >> ret = fn(info, data); >> + if (ret) >> + break; >> } >> + rcu_read_unlock(); > > Can't we just open code this in the caller now? That's better. I will remove this helper and make iteration in the only caller. > >> const struct iommu_ops intel_iommu_ops; >> @@ -900,7 +898,8 @@ static void pgtable_walk(struct intel_iommu *iommu, unsigned long pfn, u8 bus, u >> struct dmar_domain *domain; >> int offset, level; >> >> - info = dmar_search_domain_by_dev_info(iommu->segment, bus, devfn); >> + info = xa_load(&device_domain_array, >> + DEVI_IDX(iommu->segment, bus, devfn)); >> if (!info || !info->domain) { >> pr_info("device [%02x:%02x.%d] not probed\n", >> bus, PCI_SLOT(devfn), PCI_FUNC(devfn)); > > Is there any refcounting or other life time protection for the info > structures? The info structure's life is managed by iommu_probe/release_device(). It is created in probe() and freed in release(). Best regards, baolu