From 6c0cc950ae670403a362bdcbf3cde0df33744928 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 9 Jan 2013 22:33:37 +0100 Subject: [PATCH] ACPI / PCI: Set root bridge ACPI handle in advance The ACPI handles of PCI root bridges need to be known to acpi_bind_one(), so that it can create the appropriate "firmware_node" and "physical_node" files for them, but currently the way it gets to know those handles is not exactly straightforward (to put it lightly). This is how it works, roughly: 1. acpi_bus_scan() finds the handle of a PCI root bridge, creates a struct acpi_device object for it and passes that object to acpi_pci_root_add(). 2. acpi_pci_root_add() creates a struct acpi_pci_root object, populates its "device" field with its argument's address (device->handle is the ACPI handle found in step 1). 3. The struct acpi_pci_root object created in step 2 is passed to pci_acpi_scan_root() and used to get resources that are passed to pci_create_root_bus(). 4. pci_create_root_bus() creates a struct pci_host_bridge object and passes its "dev" member to device_register(). 5. platform_notify(), which for systems with ACPI is set to acpi_platform_notify(), is called. So far, so good. Now it starts to be "interesting". 6. acpi_find_bridge_device() is used to find the ACPI handle of the given device (which is the PCI root bridge) and executes acpi_pci_find_root_bridge(), among other things, for the given device object. 7. acpi_pci_find_root_bridge() uses the name (sic!) of the given device object to extract the segment and bus numbers of the PCI root bridge and passes them to acpi_get_pci_rootbridge_handle(). 8. acpi_get_pci_rootbridge_handle() browses the list of ACPI PCI root bridges and finds the one that matches the given segment and bus numbers. Its handle is then used to initialize the ACPI handle of the PCI root bridge's device object by acpi_bind_one(). However, this is *exactly* the ACPI handle we started with in step 1. Needless to say, this is quite embarassing, but it may be avoided thanks to commit f3fd0c8 (ACPI: Allow ACPI handles of devices to be initialized in advance), which makes it possible to initialize the ACPI handle of a device before passing it to device_register(). Accordingly, add a new __weak routine, pcibios_root_bridge_prepare(), defaulting to an empty implementation that can be replaced by the interested architecutres (x86 and ia64 at the moment) with functions that will set the root bridge's ACPI handle before its dev member is passed to device_register(). Make both x86 and ia64 provide such implementations of pcibios_root_bridge_prepare() and remove acpi_pci_find_root_bridge() and acpi_get_pci_rootbridge_handle() that aren't necessary any more. Included is a fix for breakage on systems with non-ACPI PCI host bridges from Bjorn Helgaas. Signed-off-by: Rafael J. Wysocki Signed-off-by: Bjorn Helgaas --- arch/ia64/pci/pci.c | 8 ++++++++ arch/x86/include/asm/pci.h | 3 +++ arch/x86/pci/acpi.c | 9 +++++++++ drivers/acpi/pci_root.c | 18 ------------------ drivers/pci/pci-acpi.c | 19 ------------------- drivers/pci/probe.c | 16 ++++++++++++++++ include/acpi/acpi_bus.h | 1 - include/linux/pci.h | 2 ++ 8 files changed, 38 insertions(+), 38 deletions(-) diff --git a/arch/ia64/pci/pci.c b/arch/ia64/pci/pci.c index 5faa66c..00e59c7 100644 --- a/arch/ia64/pci/pci.c +++ b/arch/ia64/pci/pci.c @@ -396,6 +396,14 @@ out1: return NULL; } +int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge) +{ + struct pci_controller *controller = bridge->bus->sysdata; + + ACPI_HANDLE_SET(&bridge->dev, controller->acpi_handle); + return 0; +} + static int __devinit is_valid_resource(struct pci_dev *dev, int idx) { unsigned int i, type_mask = IORESOURCE_IO | IORESOURCE_MEM; diff --git a/arch/x86/include/asm/pci.h b/arch/x86/include/asm/pci.h index dba7805..9f437e9 100644 --- a/arch/x86/include/asm/pci.h +++ b/arch/x86/include/asm/pci.h @@ -14,6 +14,9 @@ struct pci_sysdata { int domain; /* PCI domain */ int node; /* NUMA node */ +#ifdef CONFIG_ACPI + void *acpi; /* ACPI-specific data */ +#endif #ifdef CONFIG_X86_64 void *iommu; /* IOMMU private data */ #endif diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c index 0c01261..3d49094 100644 --- a/arch/x86/pci/acpi.c +++ b/arch/x86/pci/acpi.c @@ -522,6 +522,7 @@ struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_pci_root *root) sd = &info->sd; sd->domain = domain; sd->node = node; + sd->acpi = device->handle; /* * Maybe the desired pci bus has been already scanned. In such case * it is unnecessary to scan the pci bus with the given domain,busnum. @@ -593,6 +594,14 @@ struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_pci_root *root) return bus; } +int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge) +{ + struct pci_sysdata *sd = bridge->bus->sysdata; + + ACPI_HANDLE_SET(&bridge->dev, sd->acpi); + return 0; +} + int __init pci_acpi_init(void) { struct pci_dev *dev = NULL; diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index 471b2dc..bf5108a 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -107,24 +107,6 @@ void acpi_pci_unregister_driver(struct acpi_pci_driver *driver) } EXPORT_SYMBOL(acpi_pci_unregister_driver); -acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus) -{ - struct acpi_pci_root *root; - acpi_handle handle = NULL; - - mutex_lock(&acpi_pci_root_lock); - list_for_each_entry(root, &acpi_pci_roots, node) - if ((root->segment == (u16) seg) && - (root->secondary.start == (u16) bus)) { - handle = root->device->handle; - break; - } - mutex_unlock(&acpi_pci_root_lock); - return handle; -} - -EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle); - /** * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge * @handle - the ACPI CA node in question. diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c index 42736e2..1c2587c 100644 --- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -302,24 +302,6 @@ static int acpi_pci_find_device(struct device *dev, acpi_handle *handle) return 0; } -static int acpi_pci_find_root_bridge(struct device *dev, acpi_handle *handle) -{ - int num; - unsigned int seg, bus; - - /* - * The string should be the same as root bridge's name - * Please look at 'pci_scan_bus_parented' - */ - num = sscanf(dev_name(dev), "pci%04x:%02x", &seg, &bus); - if (num != 2) - return -ENODEV; - *handle = acpi_get_pci_rootbridge_handle(seg, bus); - if (!*handle) - return -ENODEV; - return 0; -} - static void pci_acpi_setup(struct device *dev) { struct pci_dev *pci_dev = to_pci_dev(dev); @@ -378,7 +360,6 @@ static void pci_acpi_cleanup(struct device *dev) static struct acpi_bus_type acpi_pci_bus = { .bus = &pci_bus_type, .find_device = acpi_pci_find_device, - .find_bridge = acpi_pci_find_root_bridge, .setup = pci_acpi_setup, .cleanup = pci_acpi_cleanup, }; diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 2dcd22d..bbe4be7 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1632,6 +1632,18 @@ unsigned int pci_scan_child_bus(struct pci_bus *bus) return max; } +/** + * pcibios_root_bridge_prepare - Platform-specific host bridge setup. + * @bridge: Host bridge to set up. + * + * Default empty implementation. Replace with an architecture-specific setup + * routine, if necessary. + */ +int __weak pcibios_root_bridge_prepare(struct pci_host_bridge *bridge) +{ + return 0; +} + struct pci_bus *pci_create_root_bus(struct device *parent, int bus, struct pci_ops *ops, void *sysdata, struct list_head *resources) { @@ -1665,6 +1677,10 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus, bridge->dev.parent = parent; bridge->dev.release = pci_release_bus_bridge_dev; dev_set_name(&bridge->dev, "pci%04x:%02x", pci_domain_nr(b), bus); + error = pcibios_root_bridge_prepare(bridge); + if (error) + goto bridge_dev_reg_err; + error = device_register(&bridge->dev); if (error) goto bridge_dev_reg_err; diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h index a9e1421..796ccc3 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -402,7 +402,6 @@ struct acpi_pci_root { /* helper */ acpi_handle acpi_get_child(acpi_handle, u64); int acpi_is_root_bridge(acpi_handle); -acpi_handle acpi_get_pci_rootbridge_handle(unsigned int, unsigned int); struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle); #define DEVICE_ACPI_HANDLE(dev) ((acpi_handle)ACPI_HANDLE(dev)) diff --git a/include/linux/pci.h b/include/linux/pci.h index 907b455..6860f4d 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -378,6 +378,8 @@ void pci_set_host_bridge_release(struct pci_host_bridge *bridge, void (*release_fn)(struct pci_host_bridge *), void *release_data); +int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge); + /* * The first PCI_BRIDGE_RESOURCE_NUM PCI bus resources (those that correspond * to P2P or CardBus bridge windows) go in a table. Additional ones (for -- 2.7.4