| From 2c62e8492ed7358bbe7da51666c7e0f6da9474ee Mon Sep 17 00:00:00 2001 |
| From: Jiang Liu <jiang.liu@linux.intel.com> |
| Date: Thu, 30 Apr 2015 12:41:28 +0800 |
| Subject: x86/PCI/ACPI: Make all resources except [io 0xcf8-0xcff] available on PCI bus |
| |
| From: Jiang Liu <jiang.liu@linux.intel.com> |
| |
| commit 2c62e8492ed7358bbe7da51666c7e0f6da9474ee upstream. |
| |
| 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. The ACPI specification defines a bit (Producer/Consumer) |
| to tell whether the resource is consumed by the host bridge itself, |
| but firmware hasn't used that bit consistently, so we can't rely on it. |
| |
| 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. |
| |
| 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. |
| |
| So explicitly filter out PCI CFG IO ports[0xCF8-0xCFF]. This solution |
| will also ease the way to consolidate ACPI PCI host bridge common code |
| from x86, ia64 and ARM64. |
| |
| Related ACPI table are archived at: |
| https://bugzilla.kernel.org/show_bug.cgi?id=94221 |
| |
| Related discussions at: |
| http://patchwork.ozlabs.org/patch/461633/ |
| https://lkml.org/lkml/2015/3/29/304 |
| |
| Fixes: 63f1789ec716 (Ignore resources consumed by host bridge itself) |
| Reported-by: Bernhard Thaler <bernhard.thaler@wvnet.at> |
| Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> |
| Reviewed-by: Bjorn Helgaas <bhelgaas@google.com> |
| Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| arch/x86/pci/acpi.c | 24 ++++++++++++++++++++++-- |
| drivers/acpi/resource.c | 2 +- |
| 2 files changed, 23 insertions(+), 3 deletions(-) |
| |
| --- a/arch/x86/pci/acpi.c |
| +++ b/arch/x86/pci/acpi.c |
| @@ -325,6 +325,26 @@ static void release_pci_root_info(struct |
| kfree(info); |
| } |
| |
| +/* |
| + * 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. The ACPI specification defines a bit (Producer/Consumer) |
| + * to tell whether the resource is consumed by the host bridge itself, |
| + * but firmware hasn't used that bit consistently, so we can't rely on it. |
| + * |
| + * 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. |
| + * |
| + * So explicitly filter out PCI CFG IO ports[0xCF8-0xCFF]. |
| + */ |
| +static bool resource_is_pcicfg_ioport(struct resource *res) |
| +{ |
| + return (res->flags & IORESOURCE_IO) && |
| + res->start == 0xCF8 && res->end == 0xCFF; |
| +} |
| + |
| static void probe_pci_root_info(struct pci_root_info *info, |
| struct acpi_device *device, |
| int busnum, int domain, |
| @@ -346,8 +366,8 @@ static void probe_pci_root_info(struct p |
| "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_is_pcicfg_ioport(entry->res)) |
| resource_list_destroy_entry(entry); |
| else |
| entry->res->name = info->name; |
| --- a/drivers/acpi/resource.c |
| +++ b/drivers/acpi/resource.c |
| @@ -573,7 +573,7 @@ EXPORT_SYMBOL_GPL(acpi_dev_get_resources |
| * @ares: Input ACPI resource object. |
| * @types: Valid resource types of IORESOURCE_XXX |
| * |
| - * This is a hepler function to support acpi_dev_get_resources(), which filters |
| + * This is a helper function to support acpi_dev_get_resources(), which filters |
| * ACPI resource objects according to resource types. |
| */ |
| int acpi_dev_filter_resource_type(struct acpi_resource *ares, |