linux/drivers/pci
Rafael J. Wysocki 6c0cc950ae 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 <rafael.j.wysocki@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2013-01-13 17:14:28 -07:00
..
hotplug ACPI: Make acpi_bus_scan() and acpi_bus_add() take only one argument 2013-01-03 13:09:40 +01:00
pcie PCI/PM: Do not suspend port if any subordinate device needs PME polling 2012-12-26 10:39:23 -07:00
access.c PCI: Add accessors for PCI Express Capability 2012-08-23 09:41:20 -06:00
ats.c Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci 2012-01-11 18:50:26 -08:00
bus.c PCI/ACPI: Reserve firmware-allocated resources for hot-added root buses 2013-01-07 15:58:48 -07:00
host-bridge.c PCI: add host bridge release support 2012-04-30 14:52:43 -06:00
hotplug-pci.c PCI: hotplug: remove pci_do_scan_bus() 2012-06-13 15:42:27 -06:00
htirq.c pci: Fix files needing export.h for EXPORT_SYMBOL/THIS_MODULE 2011-10-31 19:31:22 -04:00
ioapic.c PCI changes for the v3.8 merge window: 2012-12-13 12:14:47 -08:00
iov.c PCI: Remove useless "!dev" tests 2012-11-09 21:40:09 -07:00
irq.c PCI: Convert dev_printk(KERN_<LEVEL> to dev_<level>( 2012-11-07 15:24:18 -07:00
Kconfig PCI: Drop bogus default from ARCH_SUPPORTS_MSI 2012-09-10 16:49:52 -06:00
Makefile PCI: Always build setup-bus when PCI is enabled 2012-11-28 13:00:58 -08:00
msi.c s390/pci: PCI adapter interrupts for MSI/MSI-X 2012-11-30 17:47:21 +01:00
msi.h PCI: MSI: Move MSI-X entry definition to pci_regs.h 2010-12-23 12:53:07 -08:00
of.c PCI: OF: Don't crash when bridge parent is NULL. 2011-08-19 08:51:37 -07:00
pci-acpi.c ACPI / PCI: Set root bridge ACPI handle in advance 2013-01-13 17:14:28 -07:00
pci-driver.c PCI changes for the v3.8 merge window: 2012-12-13 12:14:47 -08:00
pci-label.c switch ->is_visible() to returning umode_t 2012-01-03 22:54:55 -05:00
pci-stub.c PCI: Convert dev_printk(KERN_<LEVEL> to dev_<level>( 2012-11-07 15:24:18 -07:00
pci-sysfs.c PCI: Remove spurious error for sriov_numvfs store and simplify flow 2012-12-26 10:39:22 -07:00
pci.c ACPI / PCI: Rework the setup and cleanup of device wakeup 2013-01-03 13:09:41 +01:00
pci.h ACPI / PCI: Rework the setup and cleanup of device wakeup 2013-01-03 13:09:41 +01:00
probe.c ACPI / PCI: Set root bridge ACPI handle in advance 2013-01-13 17:14:28 -07:00
proc.c PCI/PM: Fix proc config reg access for D3cold and bridge suspending 2012-11-05 10:46:23 -07:00
quirks.c PCI: Reduce Ricoh 0xe822 SD card reader base clock frequency to 50MHz 2012-12-26 10:43:06 -07:00
remove.c PCI: Add pci_stop_and_remove_root_bus() 2012-11-03 16:26:37 -06:00
rom.c PCI: Use phys_addr_t for physical ROM address 2012-12-10 11:24:42 -07:00
search.c Merge branch 'pci/feng-avoid-kmalloc' into next 2012-09-10 16:31:08 -06:00
setup-bus.c PCI: Move out pci_enable_bridges out of assign_unsigned_bus_res 2012-11-03 16:20:30 -06:00
setup-irq.c PCI: Provide a default pcibios_update_irq() 2012-09-18 17:28:21 -06:00
setup-res.c Merge branch 'pci/nikhil-big-bar-fixes' into next 2012-07-18 14:06:20 -06:00
slot.c pci: add module.h to files implicitly relying on its presence. 2011-10-31 19:31:23 -04:00
syscall.c
vpd.c pci: Fix files needing export.h for EXPORT_SYMBOL/THIS_MODULE 2011-10-31 19:31:22 -04:00
xen-pcifront.c PCI changes for the v3.8 merge window: 2012-12-13 12:14:47 -08:00