From patchwork Mon Apr 10 11:58:14 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yongji Xie X-Patchwork-Id: 748973 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [103.22.144.68]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3w1pr2192Yz9sD5 for ; Mon, 10 Apr 2017 22:08:50 +1000 (AEST) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="gLDPsIID"; dkim-atps=neutral Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 3w1pr205BLzDqP5 for ; Mon, 10 Apr 2017 22:08:50 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="gLDPsIID"; dkim-atps=neutral X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Received: from mail-pf0-x241.google.com (mail-pf0-x241.google.com [IPv6:2607:f8b0:400e:c00::241]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3w1phy1XRwzDqFx for ; Mon, 10 Apr 2017 22:02:42 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="gLDPsIID"; dkim-atps=neutral Received: by mail-pf0-x241.google.com with SMTP id o126so8795803pfb.1 for ; Mon, 10 Apr 2017 05:02:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=dXXTzs6A/XkbFyx4Bjsssw2gS1VJ8l/+B0sSvvs00lE=; b=gLDPsIIDG4O8yNuekf/FWTVlMtFl48vXpMLhWOjtNrg6pgRoyGkf5z+0UDJIZ4NKA3 edSGp3Opl5uwIDCLT7dXrBq16dGBsDQsA79Xu5BcokNaZBUIRRAdJwcBSZXvqNVHfP28 /NKzcU+WNWz4q0/rdAWSOU40TiZR61gsSWVnqSNUHrApxxBp1C+V6PchCBHzcSGpt2lL O/ersHQYzLRr7GwO/y6ZvISLjJNOjqW0MCjyhf3DIeFezpkxHEkB6A6Vqcnk4YjXQ7pY +/7sFjW2Eur1fRvl890nihMIC1HWm/f86ZuFsp4WcxEJrQahuwxFp3z1nxV8nJWztkZg /m6Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=dXXTzs6A/XkbFyx4Bjsssw2gS1VJ8l/+B0sSvvs00lE=; b=AfumAI3+s1mV0D1625I0DxvMnSZlBu7y3D/I655VCbnhKntm+fKS314I1ChJJwykwQ NbRjNUfTfh3Da/NKtBNPqiiiMQyJzBCfrSZA3DLapeB6PErlrLe0fENGUj/WzgAvqgic qIp+HwcJZP2roAxwx2/R6tUmLxihkTfgPVA2VCNfIdbKT7/YbGx46qIYdEnm0kFGSLhU eYKwqVJiHPvSd/uLocRlx25mZFF7dAJNlcKrBShl73yLTap4gPPk8cnCIoVD9JnUump4 iWll4wtFXJVA7fx7fDh66Df53RZ2v8ZGNzvmYAJQ6HqUDTY6ncDHDuP7P8eUAmm8TLmH eWqw== X-Gm-Message-State: AFeK/H0Jf/48rJ/0dl6vrKRepGwqixzf7k0bAIPSu9u+7WwmiB07iKeWhYyff+B8xLAr7g== X-Received: by 10.84.211.97 with SMTP id b88mr68817708pli.113.1491825759562; Mon, 10 Apr 2017 05:02:39 -0700 (PDT) Received: from localhost ([116.247.112.152]) by smtp.gmail.com with ESMTPSA id 74sm24433098pfn.102.2017.04.10.05.02.38 (version=TLS1_2 cipher=AES128-SHA bits=128/128); Mon, 10 Apr 2017 05:02:39 -0700 (PDT) From: Yongji Xie To: bhelgaas@google.com Subject: [PATCH v10 4/4] PCI: Don't extend device's size when using default alignment for all devices Date: Mon, 10 Apr 2017 19:58:14 +0800 Message-Id: <1491825494-19331-5-git-send-email-elohimes@gmail.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1491825494-19331-1-git-send-email-elohimes@gmail.com> References: <1491825494-19331-1-git-send-email-elohimes@gmail.com> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: zhong@linux.vnet.ibm.com, aik@ozlabs.ru, linux-pci@vger.kernel.org, gwshan@linux.vnet.ibm.com, alex.williamson@redhat.com, paulus@samba.org, linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" Currently we reassign the alignment by extending resources' size in pci_reassigndev_resource_alignment(). This could potentially break some drivers when the driver uses the size to locate register whose length is related to the size. Some examples as below: - misc/Hpilo.c: off = pci_resource_len(pdev, bar) - 0x2000; - net/ethernet/chelsio/cxgb4/cxgb4_uld.h: (pci_resource_len((pdev), 2) - roundup_pow_of_two((vres)->ocq.size)) - infiniband/hw/nes/Nes_hw.c: num_pds = pci_resource_len(nesdev->pcidev, BAR_1) >> PAGE_SHIFT; This risk could be easily prevented before because we only had one way (kernel parameter resource_alignment) to touch those codes. And even some users may be happy to see the extended size. But now we introduce pcibios_default_alignment() to set default alignment for all PCI devices which would also touch those codes. It would be hard to prevent the risk in this case. So this patch tries to use START_ALIGNMENT to identify the resource's alignment without extending the size when the alignment reassigning is caused by the default alignment. Signed-off-by: Yongji Xie --- drivers/pci/pci.c | 34 ++++++++++++++++++++++++---------- 1 file changed, 24 insertions(+), 10 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 02f1255..358366e 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4959,11 +4959,13 @@ resource_size_t __weak pcibios_default_alignment(struct pci_dev *dev) /** * 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; unsigned short vendor, device, subsystem_vendor, subsystem_device; @@ -5005,6 +5007,7 @@ static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev) (!device || (device == dev->device)) && (!subsystem_vendor || (subsystem_vendor == dev->subsystem_vendor)) && (!subsystem_device || (subsystem_device == dev->subsystem_device))) { + *resize = true; if (align_order == -1) align = PAGE_SIZE; else @@ -5030,6 +5033,7 @@ static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev) bus == dev->bus->number && slot == PCI_SLOT(dev->devfn) && func == PCI_FUNC(dev->devfn)) { + *resize = true; if (align_order == -1) align = PAGE_SIZE; else @@ -5062,6 +5066,7 @@ void pci_reassigndev_resource_alignment(struct pci_dev *dev) struct resource *r; resource_size_t align, size; u16 command; + bool resize = false; /* * VF BARs are read-only zero according to SR-IOV spec r1.1, sec @@ -5073,7 +5078,7 @@ void pci_reassigndev_resource_alignment(struct pci_dev *dev) return; /* 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; @@ -5101,15 +5106,24 @@ void pci_reassigndev_resource_alignment(struct pci_dev *dev) } 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->start = 0; + } else { + if (size < align) { + r->flags &= ~IORESOURCE_SIZEALIGN; + r->flags |= IORESOURCE_STARTALIGN | + IORESOURCE_UNSET; + r->start = align; + } } - r->flags |= IORESOURCE_UNSET; - r->end = size - 1; - r->start = 0; + r->end = r->start + size - 1; } /* Need to disable bridge's resource window, * to enable the kernel to reassign new resource