From patchwork Thu Jun 2 05:46:50 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yongji Xie X-Patchwork-Id: 628964 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3rKxDg1hLxz9t3s for ; Thu, 2 Jun 2016 15:51:31 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752122AbcFBFvZ (ORCPT ); Thu, 2 Jun 2016 01:51:25 -0400 Received: from e19.ny.us.ibm.com ([129.33.205.209]:55279 "EHLO e19.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751622AbcFBFvN (ORCPT ); Thu, 2 Jun 2016 01:51:13 -0400 Received: from localhost by e19.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Thu, 2 Jun 2016 01:51:09 -0400 X-IBM-Helo: d01dlp02.pok.ibm.com X-IBM-MailFrom: xyjxie@linux.vnet.ibm.com X-IBM-RcptTo: mpe@ellerman.id.au; bhelgaas@google.com; benh@kernel.crashing.org; linuxppc-dev@lists.ozlabs.org; corbet@lwn.net; aik@ozlabs.ru; alex.williamson@redhat.com; paulus@samba.org; linux-doc@vger.kernel.org; linux-kernel@vger.kernel.org; linux-pci@vger.kernel.org Received: from b01cxnp22036.gho.pok.ibm.com (b01cxnp22036.gho.pok.ibm.com [9.57.198.26]) by d01dlp02.pok.ibm.com (Postfix) with ESMTP id BB5B66E803C; Thu, 2 Jun 2016 01:50:51 -0400 (EDT) Received: from b01ledav005.gho.pok.ibm.com (b01ledav005.gho.pok.ibm.com [9.57.199.110]) by b01cxnp22036.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u525p83D44630250; Thu, 2 Jun 2016 05:51:08 GMT Received: from b01ledav005.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 7C127AE03B; Thu, 2 Jun 2016 01:51:08 -0400 (EDT) Received: from localhost (unknown [9.186.9.18]) by b01ledav005.gho.pok.ibm.com (Postfix) with ESMTP id 26347AE051; Thu, 2 Jun 2016 01:51:08 -0400 (EDT) From: Yongji Xie To: linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-doc@vger.kernel.org Cc: bhelgaas@google.com, alex.williamson@redhat.com, aik@ozlabs.ru, benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, corbet@lwn.net, warrier@linux.vnet.ibm.com, zhong@linux.vnet.ibm.com, nikunj@linux.vnet.ibm.com, gwshan@linux.vnet.ibm.com Subject: [RESEND PATCH v2 3/4] PCI: Add a new option for resource_alignment to reassign alignment Date: Thu, 2 Jun 2016 13:46:50 +0800 Message-Id: <1464846411-16895-4-git-send-email-xyjxie@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1464846411-16895-1-git-send-email-xyjxie@linux.vnet.ibm.com> References: <1464846411-16895-1-git-send-email-xyjxie@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16060205-0057-0000-0000-0000047D7362 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org When using resource_alignment kernel parameter, the current implement reassigns the alignment by changing resources' size which can potentially break some drivers. For example, the driver uses the size to locate some register whose length is related to the size. 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 | 35 +++++++++++++++++++++++++---------- 2 files changed, 29 insertions(+), 11 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 82b42c9..c4802f5 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2997,13 +2997,16 @@ 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 a259394..3ee13e5 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4748,11 +4748,13 @@ static DEFINE_SPINLOCK(resource_alignment_lock); /** * pci_specified_resource_alignment - get resource alignment specified by user. * @dev: the PCI device to get + * @resize: whether or not to change resources' size when reassigning alignment * * 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; @@ -4786,6 +4788,11 @@ 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) && @@ -4818,11 +4825,12 @@ void pci_reassigndev_resource_alignment(struct pci_dev *dev) { int i; struct resource *r; + bool resize = true; 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; @@ -4844,15 +4852,22 @@ 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 { + r->flags &= ~IORESOURCE_SIZEALIGN; + r->flags |= IORESOURCE_STARTALIGN | IORESOURCE_UNSET; + r->start = max(align, size); + 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