ioapic_xlate provides a translation from the information in device tree
to ioapic related informations. This includes
- obtaining hw irq which is the vector number "=> pin number + gsi"
- obtaining type (level/edge/..)
- programming this information into ioapic

ioapic_add_ofnode adds an irq_domain based on informations from the device
tree. This information (irq_domain) is required in order to map a device to
its proper interrupt controller.

[ tglx: Adapted to the io_apic changes, which let us move that whole code
  	to devicetree.c ]
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NDirk Brandewie <dirk.brandewie@gmail.com>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Cc: sodaville@linutronix.de
Cc: devicetree-discuss@lists.ozlabs.org
LKML-Reference: <1298405266-1624-10-git-send-email-bigeasy@linutronix.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

x86_of_pci_init() does two things:

- it provides a generic irq enable and disable function. enable queries
  the device tree for the interrupt information, calls ->xlate on the
  irq host and updates the pci->irq information for the device.

- it walks through PCI bus(es) in the device tree and adds its children
  (device) nodes to appropriate pci_dev nodes in kernel. So the dtb
  node information is available at probe time of the PCI device.

Adding a PCI bus based on the information in the device tree is
currently not supported. Right now direct access via ioports is used.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: NDirk Brandewie <dirk.brandewie@gmail.com>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Cc: sodaville@linutronix.de
Cc: devicetree-discuss@lists.ozlabs.org
LKML-Reference: <1298405266-1624-8-git-send-email-bigeasy@linutronix.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

APIC and IO_APIC have to be added to the system early because
native_init_IRQ() requires it.

In order to obtain the address of the ioapic the device tree has to be
unflattened so of_address_to_resource() works.

The device tree is relocated to ensure it is always covered by the
kernel mapping. That way the boot loader does not have to make
any assumptions about kernel's memory layout.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Cc: sodaville@linutronix.de
Cc: devicetree-discuss@lists.ozlabs.org
Cc: Dirk Brandewie <dirk.brandewie@gmail.com>
LKML-Reference: <1298405266-1624-6-git-send-email-bigeasy@linutronix.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The here introduced irq_domain abstraction represents a generic irq
controller. It is a subset of powerpc's irq_host which is going to be
renamed to irq_domain and then become generic. This implementation will
be removed once it is generic.

The xlate callback is resposible to parse irq informations like irq type
and number and returns the hardware irq number which is reported by the
hardware as active.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: NDirk Brandewie <dirk.brandewie@gmail.com>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Cc: sodaville@linutronix.de
Cc: devicetree-discuss@lists.ozlabs.org
LKML-Reference: <1298405266-1624-5-git-send-email-bigeasy@linutronix.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

This patch adds minimal support for device tree on x86. The device
tree blob is passed to the kernel via setup_data which requires at
least boot protocol 2.09.

Memory size, restricted memory regions, boot arguments are gathered
the traditional way so things like cmd_line are just here to let the
code compile.

The current plan is use the device tree as an extension and to gather
information which can not be enumerated and would have to be hardcoded
otherwise. This includes things like 
   - which devices are on this I2C/SPI bus?
   - how are the interrupts wired to IO APIC?
   - where could my hpet be?
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NDirk Brandewie <dirk.brandewie@gmail.com>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Cc: sodaville@linutronix.de
Cc: devicetree-discuss@lists.ozlabs.org
LKML-Reference: <1298405266-1624-3-git-send-email-bigeasy@linutronix.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Make use of PROC_DEVICETREE to export the tree, and sparc's PROMTREE code to
call into OLPC's Open Firmware to build the tree.

v5: fix buglet with root node check (introduced in v4)

v4: address some minor style issues pointed out by Grant, and explicitly cast
    negative phandle checks to s32.

v3: rename olpc_prom to olpc_dt
  - rework Kconfig entries
  - drop devtree build hook from proc, instead adding a call to x86's
    paging_init (similarly to how sparc64 does it)
  - switch allocation from using slab to alloc_bootmem.  this allows
    the DT to be built earlier during boot (during setup_arch); the
    downside is that there are some 1200 bootmem reservations that are
    done during boot.  Not ideal..
  - add a helper olpc_ofw_is_installed function to test for the
    existence and successful detection of OLPC's OFW.
Signed-off-by: NAndres Salomon <dilinger@queued.net>
LKML-Reference: <20101116220952.26526a80@queued.net>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>