Neither CONFIG_OLPC_OPENFIRMWARE nor CONFIG_OLPC_OPENFIRMWARE_DT are
really necessary.

OLPC selects OLPC_OPENFIRMWARE unconditionally, so move the "select
OF" part under OLPC config option and fixup the dependencies in
Makefiles and code.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Andres Salomon <dilinger@queued.net>

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>

The XO-1.5 laptop is not currently detected as an OLPC machine because
it fails this XO-1-centric check.

Now that we have OLPC OFW support in the kernel, a more sensible
check is to see if we found OFW during boot and check the architecture
property.

Also remove a now-meaningless codepath, as we're always going to have
OFW support with OLPC.
Signed-off-by: NDaniel Drake <dsd@laptop.org>
LKML-Reference: <20100923162846.D8D409D401B@zog.reactivated.net>
Cc: Andres Salomon <dilinger@queued.net>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

The arguments passed to OFW shouldn't be modified; update the 'args'
argument of olpc_ofw to reflect this.  This saves us some later
casting away of consts.
Signed-off-by: NAndres Salomon <dilinger@queued.net>
LKML-Reference: <20100628220029.1555ac24@debian>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Add support for saving OFW's cif, and later calling into it to run OFW
commands.  OFW remains resident in memory, living within virtual range
0xff800000 - 0xffc00000.  A single page directory entry points to the
pgdir that OFW actually uses, so rather than saving the entire page
table, we grab and install that one entry permanently in the kernel's
page table.

This is currently only used by the OLPC XO.  Note that this particular
calling convention breaks PAE and PAT, and so cannot be used on newer
x86 hardware.
Signed-off-by: NAndres Salomon <dilinger@queued.net>
LKML-Reference: <20100618174653.7755a39a@dev.queued.net>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>