From 2c62e8492ed7358bbe7da51666c7e0f6da9474ee Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Thu, 30 Apr 2015 12:41:28 +0800 Subject: 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 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 Signed-off-by: Jiang Liu Cc: 4.0+ # 4.0+ Reviewed-by: Bjorn Helgaas Signed-off-by: Rafael J. Wysocki --- drivers/acpi/resource.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c index 5589a6e2a023..8244f013f210 100644 --- 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, -- cgit v1.2.3