From patchwork Thu Sep 17 22:02:11 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Daney X-Patchwork-Id: 7211241 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id C8406BEEC1 for ; Thu, 17 Sep 2015 22:04:58 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id D21E320723 for ; Thu, 17 Sep 2015 22:04:57 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 094C8204FC for ; Thu, 17 Sep 2015 22:04:57 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZchH5-0003xq-MC; Thu, 17 Sep 2015 22:03:27 +0000 Received: from mail-io0-x231.google.com ([2607:f8b0:4001:c06::231]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZchGO-0003Rl-HM for linux-arm-kernel@lists.infradead.org; Thu, 17 Sep 2015 22:02:45 +0000 Received: by iofh134 with SMTP id h134so37768578iof.0 for ; Thu, 17 Sep 2015 15:02:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=ZyAxXfTU1O3dgDFbybuTBySuMjNWmLTU1AybdjrBTmY=; b=WSuKQ02iVeED4M4x/RpEUVyglpWYr9vlKR8CLrsvT4MYXKZCfImr9LAT+X81HEVC9j 8klJ6L42UMATZhtgocEY3r1hatLTYxLAh/HioZFH2rsobLPUx1M2lpHrJmli99z5ZRCQ 4fwgK/bi+PQys0vgUjjyL56IogQMqwzHKhmz2QJvorpZNlFwHXJ62rd0+6g79AdHIaQ+ JyPaBtouVkyoG4xOJ+BpjlnSA93h2l98gSdeX1GsTBYv6UTtlMfuGG3iARcmjwlX/XBG CKVt2mCjXd+Gsj/6wYlvYGS4VxK3F5pL2Nwh1n4kYVXEMME0il8ukbEkV4CyN3shwgmI qz1g== X-Received: by 10.107.9.151 with SMTP id 23mr11454335ioj.170.1442527343630; Thu, 17 Sep 2015 15:02:23 -0700 (PDT) Received: from dl.caveonetworks.com (64.2.3.194.ptr.us.xo.net. [64.2.3.194]) by smtp.gmail.com with ESMTPSA id qh9sm5101638igb.20.2015.09.17.15.02.19 (version=TLSv1 cipher=RC4-SHA bits=128/128); Thu, 17 Sep 2015 15:02:20 -0700 (PDT) Received: from dl.caveonetworks.com (localhost.localdomain [127.0.0.1]) by dl.caveonetworks.com (8.14.5/8.14.5) with ESMTP id t8HM2I70001238; Thu, 17 Sep 2015 15:02:18 -0700 Received: (from ddaney@localhost) by dl.caveonetworks.com (8.14.5/8.14.5/Submit) id t8HM2Itg001237; Thu, 17 Sep 2015 15:02:18 -0700 From: David Daney To: linux-kernel@vger.kernel.org, Bjorn Helgaas , linux-pci@vger.kernel.org, Will Deacon , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, Marc Zyngier Subject: [PATCH v2 4/5] PCI: generic: Correct, and avoid overflow, in bus_max calculation. Date: Thu, 17 Sep 2015 15:02:11 -0700 Message-Id: <1442527332-1174-5-git-send-email-ddaney.cavm@gmail.com> X-Mailer: git-send-email 1.7.11.7 In-Reply-To: <1442527332-1174-1-git-send-email-ddaney.cavm@gmail.com> References: <1442527332-1174-1-git-send-email-ddaney.cavm@gmail.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150917_150244_705018_AB921B82 X-CRM114-Status: GOOD ( 14.66 ) X-Spam-Score: -2.7 (--) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: David Daney MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.1 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_MED, T_DKIM_INVALID, T_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 From: David Daney There are two problems with the bus_max calculation: 1) The u8 data type can overflow for large config space windows. 2) The calculation is incorrect for a bus range that doesn't start at zero. Since the configuration space is relative to bus zero, make bus_max just be the size of the config window scaled by bus_shift. Then clamp it to a maximum of 255, per PCI. Use a data type of int to avoid overflow problems. Update host-generic-pci.txt to clarify the semantics of the "reg" property with respect to non-zero starting bus numbers. Signed-off-by: David Daney --- Change from v1: Added text to host-generic-pci.txt Documentation/devicetree/bindings/pci/host-generic-pci.txt | 4 +++- drivers/pci/host/pci-host-generic.c | 7 ++++--- 2 files changed, 7 insertions(+), 4 deletions(-) diff --git a/Documentation/devicetree/bindings/pci/host-generic-pci.txt b/Documentation/devicetree/bindings/pci/host-generic-pci.txt index cf3e205..105a968 100644 --- a/Documentation/devicetree/bindings/pci/host-generic-pci.txt +++ b/Documentation/devicetree/bindings/pci/host-generic-pci.txt @@ -34,7 +34,9 @@ Properties of the host controller node: - #size-cells : Must be 2. - reg : The Configuration Space base address and size, as accessed - from the parent bus. + from the parent bus. The base address corresponds to + bus zero, even though the "bus-range" property may specify + a different starting bus number. Properties of the /chosen node: diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c index 77cf4bd..0a9c453 100644 --- a/drivers/pci/host/pci-host-generic.c +++ b/drivers/pci/host/pci-host-generic.c @@ -164,7 +164,7 @@ out_release_res: static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci) { int err; - u8 bus_max; + int bus_max; resource_size_t busn; struct resource *bus_range; struct device *dev = pci->host.dev.parent; @@ -177,8 +177,9 @@ static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci) } /* Limit the bus-range to fit within reg */ - bus_max = pci->cfg.bus_range->start + - (resource_size(&pci->cfg.res) >> pci->cfg.ops.bus_shift) - 1; + bus_max = (resource_size(&pci->cfg.res) >> pci->cfg.ops.bus_shift) - 1; + if (bus_max > 255) + bus_max = 255; pci->cfg.bus_range->end = min_t(resource_size_t, pci->cfg.bus_range->end, bus_max);