Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031313AbbD2APS (ORCPT ); Tue, 28 Apr 2015 20:15:18 -0400 Received: from v094114.home.net.pl ([79.96.170.134]:59565 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1031108AbbD2APP (ORCPT ); Tue, 28 Apr 2015 20:15:15 -0400 From: "Rafael J. Wysocki" To: Jiang Liu , Bjorn Helgaas , Ingo Molnar Cc: Thomas Gleixner , "H. Peter Anvin" , x86@kernel.org, Len Brown , Lv Zheng , LKML , linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org Subject: Re: [Bugfix v5] x86/PCI/ACPI: Fix regression caused by commit 63f1789ec716 Date: Wed, 29 Apr 2015 02:40:07 +0200 Message-ID: <3492366.RzMG5dcPfN@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/4.0.0+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <1429499338-16967-1-git-send-email-jiang.liu@linux.intel.com> References: <1429499338-16967-1-git-send-email-jiang.liu@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5609 Lines: 131 On Monday, April 20, 2015 11:08:58 AM Jiang Liu wrote: > 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 Bjorn, Ingo, is anyone looking at this? We're still having a regression in this area ... > --- > 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: > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- 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/