From patchwork Mon Mar 27 09:49:35 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lorenzo Pieralisi X-Patchwork-Id: 9645993 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 962A960328 for ; Mon, 27 Mar 2017 09:50:44 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 749E8228C9 for ; Mon, 27 Mar 2017 09:50:44 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 695362833B; Mon, 27 Mar 2017 09:50:44 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1856A28358 for ; Mon, 27 Mar 2017 09:50:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752894AbdC0Jud (ORCPT ); Mon, 27 Mar 2017 05:50:33 -0400 Received: from foss.arm.com ([217.140.101.70]:59514 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752886AbdC0Ju3 (ORCPT ); Mon, 27 Mar 2017 05:50:29 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5FFA2165C; Mon, 27 Mar 2017 02:50:23 -0700 (PDT) Received: from red-moon.cambridge.arm.com (red-moon.cambridge.arm.com [10.1.206.55]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0C3CC3F23B; Mon, 27 Mar 2017 02:50:18 -0700 (PDT) From: Lorenzo Pieralisi To: linux-pci@vger.kernel.org Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Lorenzo Pieralisi , Bjorn Helgaas , Arnd Bergmann , Will Deacon , Catalin Marinas , Russell King , Pratyush Anand , Jingoo Han , Mingkai Hu , John Garry , Tanmay Inamdar , Murali Karicheri , Bharat Kumar Gogada , Ray Jui , Wenrui Li , Shawn Lin , Minghuan Lian , Jon Mason , Gabriele Paoloni , Thomas Petazzoni , Joao Pinto , Thierry Reding , Michal Simek , Stanimir Varbanov , Zhou Wang , Roy Zang , "Luis R. Rodriguez" Subject: [PATCH v2 07/22] PCI: ECAM: use ioremap_nopost() to map config region Date: Mon, 27 Mar 2017 10:49:35 +0100 Message-Id: <20170327094954.7162-8-lorenzo.pieralisi@arm.com> X-Mailer: git-send-email 2.10.0 In-Reply-To: <20170327094954.7162-1-lorenzo.pieralisi@arm.com> References: <20170327094954.7162-1-lorenzo.pieralisi@arm.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Current ECAM kernel implementation uses ioremap() to map the ECAM configuration space memory region; this is not safe in that on some architectures the ioremap interface provides mappings that allow posted write transactions. This, as highlighted in the PCIe specifications (4.0 - Rev0.3, "Ordering Considerations for the Enhanced Configuration Address Mechanism"), can create ordering issues for software because posted writes transactions on the CPU host bus are non posted in the PCI express fabric. Update the ioremap() interface to use ioremap_nopost() whose mapping attributes guarantee that non-posted writes transactions are issued for memory writes within the ECAM memory mapped address region. Signed-off-by: Lorenzo Pieralisi Cc: Bjorn Helgaas Acked-by: Will Deacon --- drivers/pci/ecam.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/pci/ecam.c b/drivers/pci/ecam.c index 2fee61b..70d722a 100644 --- a/drivers/pci/ecam.c +++ b/drivers/pci/ecam.c @@ -84,12 +84,13 @@ struct pci_config_window *pci_ecam_create(struct device *dev, if (!cfg->winp) goto err_exit_malloc; for (i = 0; i < bus_range; i++) { - cfg->winp[i] = ioremap(cfgres->start + i * bsz, bsz); + cfg->winp[i] = ioremap_nopost(cfgres->start + i * bsz, + bsz); if (!cfg->winp[i]) goto err_exit_iomap; } } else { - cfg->win = ioremap(cfgres->start, bus_range * bsz); + cfg->win = ioremap_nopost(cfgres->start, bus_range * bsz); if (!cfg->win) goto err_exit_iomap; }