From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967220AbdDSQxr (ORCPT ); Wed, 19 Apr 2017 12:53:47 -0400 Received: from foss.arm.com ([217.140.101.70]:44278 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966768AbdDSQtb (ORCPT ); Wed, 19 Apr 2017 12:49:31 -0400 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 , Jayachandran C , Arnd Bergmann , Will Deacon , Catalin Marinas , Russell King , Benjamin Herrenschmidt , 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 v4 07/21] PCI: ECAM: use pci_remap_cfgspace() to map config region Date: Wed, 19 Apr 2017 17:48:56 +0100 Message-Id: <20170419164913.19674-8-lorenzo.pieralisi@arm.com> X-Mailer: git-send-email 2.10.0 In-Reply-To: <20170419164913.19674-1-lorenzo.pieralisi@arm.com> References: <20170419164913.19674-1-lorenzo.pieralisi@arm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 pci_remap_cfgspace() 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 Cc: Jayachandran C --- drivers/pci/ecam.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/pci/ecam.c b/drivers/pci/ecam.c index 2fee61b..c228a2e 100644 --- a/drivers/pci/ecam.c +++ b/drivers/pci/ecam.c @@ -84,12 +84,14 @@ 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] = + pci_remap_cfgspace(cfgres->start + i * bsz, + bsz); if (!cfg->winp[i]) goto err_exit_iomap; } } else { - cfg->win = ioremap(cfgres->start, bus_range * bsz); + cfg->win = pci_remap_cfgspace(cfgres->start, bus_range * bsz); if (!cfg->win) goto err_exit_iomap; } -- 2.10.0