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Commit 2c62e849 authored by Jiang Liu's avatar Jiang Liu Committed by Rafael J. Wysocki
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x86/PCI/ACPI: Make all resources except [io 0xcf8-0xcff] available on PCI bus 

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 593669c2 ("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 593669c2 ("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 63f1789e ("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: 63f1789e (Ignore resources consumed by host bridge itself)
Reported-by: default avatarBernhard Thaler <bernhard.thaler@wvnet.at>
Signed-off-by: default avatarJiang Liu <jiang.liu@linux.intel.com>
Cc: 4.0+ <stable@vger.kernel.org> # 4.0+
Reviewed-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent b787f68c

arch/x86/pci/acpi.c

+22 −2
Original line number Original line Diff line number Diff line
@@ -325,6 +325,26 @@ static void release_pci_root_info(struct pci_host_bridge *bridge) 
	kfree(info);

	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,

static void probe_pci_root_info(struct pci_root_info *info,

				struct acpi_device *device,

				struct acpi_device *device,

				int busnum, int domain,

				int busnum, int domain,
@@ -346,8 +366,8 @@ static void probe_pci_root_info(struct pci_root_info *info, 
			"no IO and memory resources present in _CRS\n");

			"no IO and memory resources present in _CRS\n");

	else

	else

		resource_list_for_each_entry_safe(entry, tmp, list) {

		resource_list_for_each_entry_safe(entry, tmp, list) {

			if ((entry->res->flags & IORESOURCE_WINDOW) == 0 ||

			if ((entry->res->flags & IORESOURCE_DISABLED) ||

			    (entry->res->flags & IORESOURCE_DISABLED))

			    resource_is_pcicfg_ioport(entry->res))

				resource_list_destroy_entry(entry);

				resource_list_destroy_entry(entry);

			else

			else

				entry->res->name = info->name;

				entry->res->name = info->name;

drivers/acpi/resource.c

+1 −1
Original line number Original line Diff line number Diff line
@@ -573,7 +573,7 @@ EXPORT_SYMBOL_GPL(acpi_dev_get_resources); 
 * @ares: Input ACPI resource object.

 * @ares: Input ACPI resource object.

 * @types: Valid resource types of IORESOURCE_XXX

 * @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.

 * ACPI resource objects according to resource types.

 */

 */

int acpi_dev_filter_resource_type(struct acpi_resource *ares,

int acpi_dev_filter_resource_type(struct acpi_resource *ares,