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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D8F8FC433FE for ; Wed, 29 Sep 2021 01:39:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B4683613C8 for ; Wed, 29 Sep 2021 01:39:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243640AbhI2Blh (ORCPT ); Tue, 28 Sep 2021 21:41:37 -0400 Received: from mga04.intel.com ([192.55.52.120]:35233 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243639AbhI2Blg (ORCPT ); Tue, 28 Sep 2021 21:41:36 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10121"; a="222947711" X-IronPort-AV: E=Sophos;i="5.85,331,1624345200"; d="scan'208";a="222947711" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Sep 2021 18:39:56 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.85,331,1624345200"; d="scan'208";a="476486375" Received: from allen-box.sh.intel.com (HELO [10.239.159.118]) ([10.239.159.118]) by orsmga007.jf.intel.com with ESMTP; 28 Sep 2021 18:39:53 -0700 Cc: baolu.lu@linux.intel.com, linux-cxl@vger.kernel.org, "open list:DMA MAPPING HELPERS" , David Woodhouse , Andrew Donnellan , Bjorn Helgaas , "David E. Box" , Frederic Barrat , Kan Liang , Linux PCI , linuxppc-dev Subject: Re: [PATCH v2 9/9] iommu/vt-d: Use pci core's DVSEC functionality To: Dan Williams , Ben Widawsky References: <20210923172647.72738-1-ben.widawsky@intel.com> <20210923172647.72738-10-ben.widawsky@intel.com> From: Lu Baolu Message-ID: <6bca371c-44e4-3ba7-b49d-78c55a40d3a5@linux.intel.com> Date: Wed, 29 Sep 2021 09:36:20 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org Hi Dan, On 9/29/21 1:54 AM, Dan Williams wrote: > On Thu, Sep 23, 2021 at 10:27 AM Ben Widawsky wrote: >> >> Reduce maintenance burden of DVSEC query implementation by using the >> centralized PCI core implementation. >> >> Cc: iommu@lists.linux-foundation.org >> Cc: David Woodhouse >> Cc: Lu Baolu >> Signed-off-by: Ben Widawsky >> --- >> drivers/iommu/intel/iommu.c | 15 +-------------- >> 1 file changed, 1 insertion(+), 14 deletions(-) >> >> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c >> index d75f59ae28e6..30c97181f0ae 100644 >> --- a/drivers/iommu/intel/iommu.c >> +++ b/drivers/iommu/intel/iommu.c >> @@ -5398,20 +5398,7 @@ static int intel_iommu_disable_sva(struct device *dev) >> */ >> static int siov_find_pci_dvsec(struct pci_dev *pdev) >> { >> - int pos; >> - u16 vendor, id; >> - >> - pos = pci_find_next_ext_capability(pdev, 0, 0x23); >> - while (pos) { >> - pci_read_config_word(pdev, pos + 4, &vendor); >> - pci_read_config_word(pdev, pos + 8, &id); >> - if (vendor == PCI_VENDOR_ID_INTEL && id == 5) >> - return pos; >> - >> - pos = pci_find_next_ext_capability(pdev, pos, 0x23); >> - } >> - >> - return 0; >> + return pci_find_dvsec_capability(pdev, PCI_VENDOR_ID_INTEL, 5); >> } > > Same comments as the CXL patch, siov_find_pci_dvsec() doesn't seem to > have a reason to exist anymore. What is 5? "5" is DVSEC ID for Scalable IOV. Anyway, the siov_find_pci_dvsec() has been dead code since commit 262948f8ba57 ("iommu: Delete iommu_dev_has_feature()"). I have a patch to clean it up. No need to care about it in this series. Best regards, baolu