From patchwork Mon Mar 7 07:48:32 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yongji Xie X-Patchwork-Id: 8516041 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 7B80D9F46A for ; Mon, 7 Mar 2016 07:49:43 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 6178720121 for ; Mon, 7 Mar 2016 07:49:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 61B832012D for ; Mon, 7 Mar 2016 07:49:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752321AbcCGHtd (ORCPT ); Mon, 7 Mar 2016 02:49:33 -0500 Received: from e28smtp04.in.ibm.com ([125.16.236.4]:56630 "EHLO e28smtp04.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752085AbcCGHtO (ORCPT ); Mon, 7 Mar 2016 02:49:14 -0500 Received: from localhost by e28smtp04.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Mon, 7 Mar 2016 13:19:04 +0530 X-IBM-Helo: d28relay01.in.ibm.com X-IBM-MailFrom: xyjxie@linux.vnet.ibm.com X-IBM-RcptTo: linux-doc@vger.kernel.org; linux-pci@vger.kernel.org; linux-kernel@vger.kernel.org; kvm@vger.kernel.org Received: from d28av05.in.ibm.com (d28av05.in.ibm.com [9.184.220.67]) by d28relay01.in.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u277n3E714090700; Mon, 7 Mar 2016 13:19:03 +0530 Received: from d28av05.in.ibm.com (localhost [127.0.0.1]) by d28av05.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u277mxC7012507; Mon, 7 Mar 2016 13:19:02 +0530 Received: from localhost (commit.cn.ibm.com [9.123.229.145]) by d28av05.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id u277mmaI011919; Mon, 7 Mar 2016 13:18:50 +0530 From: Yongji Xie To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-doc@vger.kernel.org Cc: bhelgaas@google.com, corbet@lwn.net, aik@ozlabs.ru, alex.williamson@redhat.com, benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, warrier@linux.vnet.ibm.com, zhong@linux.vnet.ibm.com, nikunj@linux.vnet.ibm.com, Yongji Xie Subject: [RFC PATCH v4 1/7] PCI: Add a new option for resource_alignment to reassign alignment Date: Mon, 7 Mar 2016 15:48:32 +0800 Message-Id: <1457336918-3893-2-git-send-email-xyjxie@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1457336918-3893-1-git-send-email-xyjxie@linux.vnet.ibm.com> References: <1457336918-3893-1-git-send-email-xyjxie@linux.vnet.ibm.com> X-TM-AS-MML: disable x-cbid: 16030707-0013-0000-0000-00000A9614D2 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When using resource_alignment kernel parameter, the current implement reassigns the alignment by changing resources' size which can potentially break some drivers. So this patch adds a new option "noresize" for the parameter to solve this problem. Signed-off-by: Yongji Xie --- Documentation/kernel-parameters.txt | 5 ++++- drivers/pci/pci.c | 36 +++++++++++++++++++++++++---------- 2 files changed, 30 insertions(+), 11 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 9a53c92..d8b29ab 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2912,13 +2912,16 @@ bytes respectively. Such letter suffixes can also be entirely omitted. window. The default value is 64 megabytes. resource_alignment= Format: - [@][:]:.[; ...] + [@][:]:. + [:noresize][; ...] Specifies alignment and device to reassign aligned memory resources. If is not specified, PAGE_SIZE is used as alignment. PCI-PCI bridge can be specified, if resource windows need to be expanded. + noresize: Don't change the resources' sizes when + reassigning alignment. ecrc= Enable/disable PCIe ECRC (transaction layer end-to-end CRC checking). bios: Use BIOS/firmware settings. This is the diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 602eb42..760cce5 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4598,7 +4598,8 @@ static DEFINE_SPINLOCK(resource_alignment_lock); * RETURNS: Resource alignment if it is specified. * Zero if it is not specified. */ -static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev) +static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev, + bool *resize) { int seg, bus, slot, func, align_order, count; resource_size_t align = 0; @@ -4626,6 +4627,11 @@ static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev) } } p += count; + if (!strncmp(p, ":noresize", 9)) { + *resize = false; + p += 9; + } else + *resize = true; if (seg == pci_domain_nr(dev->bus) && bus == dev->bus->number && slot == PCI_SLOT(dev->devfn) && @@ -4658,11 +4664,12 @@ void pci_reassigndev_resource_alignment(struct pci_dev *dev) { int i; struct resource *r; + bool resize; resource_size_t align, size; u16 command; /* check if specified PCI is target device to reassign */ - align = pci_specified_resource_alignment(dev); + align = pci_specified_resource_alignment(dev, &resize); if (!align) return; @@ -4684,15 +4691,24 @@ void pci_reassigndev_resource_alignment(struct pci_dev *dev) if (!(r->flags & IORESOURCE_MEM)) continue; size = resource_size(r); - if (size < align) { - size = align; - dev_info(&dev->dev, - "Rounding up size of resource #%d to %#llx.\n", - i, (unsigned long long)size); + if (resize) { + if (size < align) { + size = align; + dev_info(&dev->dev, + "Rounding up size of resource #%d to %#llx.\n", + i, (unsigned long long)size); + } + r->flags |= IORESOURCE_UNSET; + r->end = size - 1; + r->start = 0; + } else { + if (size > align) + align = size; + r->flags &= ~IORESOURCE_SIZEALIGN; + r->flags |= IORESOURCE_STARTALIGN | IORESOURCE_UNSET; + r->start = align; + r->end = r->start + size - 1; } - r->flags |= IORESOURCE_UNSET; - r->end = size - 1; - r->start = 0; } /* Need to disable bridge's resource window, * to enable the kernel to reassign new resource