From patchwork Mon Aug 15 16:50:42 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lorenzo Pieralisi X-Patchwork-Id: 659348 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 3sChMz4lJZz9t3V for ; Tue, 16 Aug 2016 02:51:27 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752812AbcHOQv1 (ORCPT ); Mon, 15 Aug 2016 12:51:27 -0400 Received: from foss.arm.com ([217.140.101.70]:41947 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752590AbcHOQv0 (ORCPT ); Mon, 15 Aug 2016 12:51:26 -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 39CA5959; Mon, 15 Aug 2016 09:52:58 -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 2D84D3F215; Mon, 15 Aug 2016 09:51:25 -0700 (PDT) From: Lorenzo Pieralisi To: linux-pci@vger.kernel.org Cc: Lorenzo Pieralisi , Bjorn Helgaas , Jingoo Han , Pratyush Anand Subject: [PATCH 2/6] drivers: pci: host: designware: fix pci_remap_iospace() failure path Date: Mon, 15 Aug 2016 17:50:42 +0100 Message-Id: <1471279854-11916-3-git-send-email-lorenzo.pieralisi@arm.com> X-Mailer: git-send-email 2.6.4 In-Reply-To: <1471279854-11916-1-git-send-email-lorenzo.pieralisi@arm.com> References: <1471279854-11916-1-git-send-email-lorenzo.pieralisi@arm.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On ARM/ARM64 architectures, PCI IO ports are emulated through memory mapped IO, by reserving a chunk of virtual address space starting at PCI_IOBASE and by mapping the PCI host bridges memory address space driving PCI IO cycles to it. PCI host bridge drivers that enable downstream PCI IO cycles map the host bridge memory address responding to PCI IO cycles to the fixed virtual address space through the pci_remap_iospace() API. This means that if the pci_remap_iospace() function fails, the corresponding host bridge PCI IO resource must be considered invalid, in that there is no way for the kernel to actually drive PCI IO transactions if the memory addresses responding to PCI IO cycles cannot be mapped into the CPU virtual address space. The PCI designware host bridge driver does not remove the PCI IO resource from the host bridge resource windows if the pci_remap_iospace() call fails; this is an actual bug in that the PCI host bridge would consider the PCI IO resource valid (and possibly assign it to downstream devices) even if the kernel was not able to map the PCI host bridge memory address driving IO cycle to the CPU virtual address space (ie pci_remap_iospace() failures). Fix the PCI host bridge driver pci_remap_iospace() failure path, by destroying the PCI host bridge PCI IO resources retrieved through firmware when the pci_remap_iospace() function call fails, therefore preventing the kernel from adding the respective PCI IO resource to the list of PCI host bridge valid resources, fixing the issue. Signed-off-by: Lorenzo Pieralisi Fixes: cbce7900598c ("PCI: designware: Make driver arch-agnostic") Cc: Bjorn Helgaas Cc: Jingoo Han Cc: Pratyush Anand --- drivers/pci/host/pcie-designware.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c index 12afce1..2a500f2 100644 --- a/drivers/pci/host/pcie-designware.c +++ b/drivers/pci/host/pcie-designware.c @@ -436,7 +436,7 @@ int dw_pcie_host_init(struct pcie_port *pp) struct resource *cfg_res; int i, ret; LIST_HEAD(res); - struct resource_entry *win; + struct resource_entry *win, *tmp; cfg_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "config"); if (cfg_res) { @@ -457,17 +457,20 @@ int dw_pcie_host_init(struct pcie_port *pp) goto error; /* Get the I/O and memory ranges from DT */ - resource_list_for_each_entry(win, &res) { + resource_list_for_each_entry_safe(win, tmp, &res) { switch (resource_type(win->res)) { case IORESOURCE_IO: - pp->io = win->res; - pp->io->name = "I/O"; - pp->io_size = resource_size(pp->io); - pp->io_bus_addr = pp->io->start - win->offset; - ret = pci_remap_iospace(pp->io, pp->io_base); - if (ret) + ret = pci_remap_iospace(win->res, pp->io_base); + if (ret) { dev_warn(pp->dev, "error %d: failed to map resource %pR\n", - ret, pp->io); + ret, win->res); + resource_list_destroy_entry(win); + } else { + pp->io = win->res; + pp->io->name = "I/O"; + pp->io_size = resource_size(pp->io); + pp->io_bus_addr = pp->io->start - win->offset; + } break; case IORESOURCE_MEM: pp->mem = win->res;