Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752573AbbDTDGu (ORCPT ); Sun, 19 Apr 2015 23:06:50 -0400 Received: from mga11.intel.com ([192.55.52.93]:62389 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751386AbbDTDGr (ORCPT ); Sun, 19 Apr 2015 23:06:47 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.11,607,1422950400"; d="scan'208";a="716083538" From: Jiang Liu To: "Rafael J . Wysocki" , Bjorn Helgaas , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Len Brown Cc: Jiang Liu , Lv Zheng , LKML , linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org Subject: [Bugfix v5] x86/PCI/ACPI: Fix regression caused by commit 63f1789ec716 Date: Mon, 20 Apr 2015 11:08:58 +0800 Message-Id: <1429499338-16967-1-git-send-email-jiang.liu@linux.intel.com> X-Mailer: git-send-email 1.7.10.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5155 Lines: 124 An IO port or MMIO resource assigned to a PCI host bridge may be consumed by the host bridge itself or available to its child bus/devices. On x86 and IA64 platforms, all IO port and MMIO resources are assumed to be available to child bus/devices except one special case: IO port [0xCF8-0xCFF] is consumed by the host bridge itself to access PCI configuration space. But the ACPI and PCI Firmware specifications haven't provided a method to tell whether a resource is consumed by the host bridge itself. So before commit 593669c2ac0f ("x86/PCI/ACPI: Use common ACPI resource interfaces to simplify implementation"), arch/x86/pci/acpi.c ignored all IO port resources defined by acpi_resource_io and acpi_resource_fixed_io to filter out IO ports consumed by the host bridge itself. Commit 593669c2ac0f ("x86/PCI/ACPI: Use common ACPI resource interfaces to simplify implementation")started accepting all IO port and MMIO resources, which caused a regression that IO port resources consumed by the host bridge itself became available to its child devices. Then commit 63f1789ec716 ("x86/PCI/ACPI: Ignore resources consumed by host bridge itself") ignored resources consumed by the host bridge itself by checking the IORESOURCE_WINDOW flag, which accidently removed MMIO resources defined by acpi_resource_memory24, acpi_resource_memory32 and acpi_resource_fixed_memory32. So revert to the behavior before v3.19 to fix the regression. There is also a discussion about ignoring the Producer/Consumer flag on IA64 platforms at: http://patchwork.ozlabs.org/patch/461633/ Related ACPI table are archived at: https://bugzilla.kernel.org/show_bug.cgi?id=94221 Fixes: 63f1789ec716("Ignore resources consumed by host bridge itself") Reported-by: Bernhard Thaler Signed-off-by: Jiang Liu --- arch/x86/pci/acpi.c | 25 ++++++++++++++++++++++--- drivers/acpi/resource.c | 6 +++++- 2 files changed, 27 insertions(+), 4 deletions(-) diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c index e4695985f9de..fc2da98985c3 100644 --- a/arch/x86/pci/acpi.c +++ b/arch/x86/pci/acpi.c @@ -332,12 +332,32 @@ static void probe_pci_root_info(struct pci_root_info *info, { int ret; struct resource_entry *entry, *tmp; + unsigned long res_flags; sprintf(info->name, "PCI Bus %04x:%02x", domain, busnum); info->bridge = device; + + /* + * An IO or MMIO resource assigned to PCI host bridge may be consumed + * by the host bridge itself or available to its child bus/devices. + * On x86 and IA64 platforms, all IO and MMIO resources are assumed to + * be available to child bus/devices except one special case: + * IO port [0xCF8-0xCFF] is consumed by host bridge itself to + * access PCI configuration space. + * + * Due to lack of specification to define resources consumed by host + * bridge itself, all IO port resources defined by acpi_resource_io + * and acpi_resource_fixed_io are ignored to filter out IO + * port[0xCF8-0xCFF]. Seems this solution works with all BIOSes, though + * it's not perfect. + * + * Another possible solution is to explicitly filter out IO + * port[0xCF8-0xCFF]. + */ + res_flags = IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_IO_FIXED; ret = acpi_dev_get_resources(device, list, acpi_dev_filter_resource_type_cb, - (void *)(IORESOURCE_IO | IORESOURCE_MEM)); + (void *)res_flags); if (ret < 0) dev_warn(&device->dev, "failed to parse _CRS method, error code %d\n", ret); @@ -346,8 +366,7 @@ static void probe_pci_root_info(struct pci_root_info *info, "no IO and memory resources present in _CRS\n"); else resource_list_for_each_entry_safe(entry, tmp, list) { - if ((entry->res->flags & IORESOURCE_WINDOW) == 0 || - (entry->res->flags & IORESOURCE_DISABLED)) + if (entry->res->flags & IORESOURCE_DISABLED) resource_list_destroy_entry(entry); else entry->res->name = info->name; diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c index 5589a6e2a023..79b6d3b5ffd2 100644 --- a/drivers/acpi/resource.c +++ b/drivers/acpi/resource.c @@ -575,6 +575,9 @@ EXPORT_SYMBOL_GPL(acpi_dev_get_resources); * * This is a hepler function to support acpi_dev_get_resources(), which filters * ACPI resource objects according to resource types. + * + * Flag IORESOURCE_IO_FIXED is used to opt out io and fixed_io resource + * descriptors for ACPI host bridges on x86 and IA64 platforms. */ int acpi_dev_filter_resource_type(struct acpi_resource *ares, unsigned long types) @@ -589,7 +592,8 @@ int acpi_dev_filter_resource_type(struct acpi_resource *ares, break; case ACPI_RESOURCE_TYPE_IO: case ACPI_RESOURCE_TYPE_FIXED_IO: - type = IORESOURCE_IO; + if ((types & IORESOURCE_IO_FIXED) == 0) + type = IORESOURCE_IO; break; case ACPI_RESOURCE_TYPE_IRQ: case ACPI_RESOURCE_TYPE_EXTENDED_IRQ: -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/