There's a few places where we need to fix things up for the kernel to work
if it's linked at 32MB:

 - platforms/powermac/smp.c
   To start secondary cpus on pmac we patch the reset vector, which is fine.
   Except if we're above 32MB we don't have enough bits for an absolute branch,
   it needs to relative.
 - kernel/head_64.s
    - A few branches in the cpu hold code need to load the full target address
      and do a bctr.
    - after_prom_start needs to load PHYSICAL_START as the dest address, not 0.
    - The exception prolog needs to load the low word of the target adddress,
      not just the low halfword.
    - Fixup handling of the initial stab address.
 - kernel/setup_64.c
   smp_release_cpus() needs to write 1 to the spinloop flag near 0, not 32 MB.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

We were using udelay in the loop on the primary cpu waiting for the
secondary cpu to take the timebase value.  Unfortunately now that
udelay uses the timebase, and the timebase is stopped at this point,
the udelay never terminated.  This fixes it by not using udelay, and
increases the number of loops before we time out to compensate.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

A couple of bugs crept in with the merge of smp.c...
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This brings in a lot of changes from arch/ppc64/kernel/pmac_*.c to
arch/powerpc/platforms/powermac/*.c and makes various minor tweaks
elsewhere.  On the powermac we now initialize ppc_md by copying
the whole pmac_md structure into it, which required some changes in
the ordering of initializations of individual fields of it.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This makes platform code use the smp_ops variable directly instead
of ppc_md.smp_ops, removes the two unused `data' and `wait' arguments
from the *_message_pass() functions, and removes the call to the
never-implemented smp_ops->space_timers() function.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Since the files are now in arch/powerpc/platforms/powermac, the
pmac_ prefix that they had is redundant.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This updates the powermac SMP code to use the mpic driver instead of
the openpic driver and fixes the SMP-dependent context switch code.
We had a subtle bug where we were using interrupt numbers 256-259 for
IPIs, but ppc32 had NR_IRQS = 256.  Moved the IPIs down to use interrupt
numbers 252-255 instead.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This creates the directory structure under arch/powerpc and a bunch
of Kconfig files.  It does a first-cut merge of arch/powerpc/mm,
arch/powerpc/lib and arch/powerpc/platforms/powermac.  This is enough
to build a 32-bit powermac kernel with ARCH=powerpc.

For now we are getting some unmerged files from arch/ppc/kernel and
arch/ppc/syslib, or arch/ppc64/kernel.  This makes some minor changes
to files in those directories and files outside arch/powerpc.

The boot directory is still not merged.  That's going to be interesting.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Here is a new patch that removes all notion of the pmac, prep,
chrp and openfirmware initialization sections, and then unifies
the sections.h files without those __pmac, etc, sections identifiers
cluttering things up.
Signed-off-by: NJon Loeliger <jdl@freescale.com>
Signed-off-by: NKumar Gala <kumar.gala@freescale.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This allows cpus to be off-lined on 32-bit SMP powermacs.  When a cpu
is off-lined, it is put into sleep mode with interrupts disabled.  It
can be on-lined again by asserting its soft-reset pin, which is
connected to a GPIO pin.

With this I can off-line the second cpu in my dual G4 powermac, which
means that I can then suspend the machine (the suspend/resume code
refuses to suspend if more than one cpu is online, and making it cope
with multiple cpus is surprisingly messy).
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAl Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Currently the procedure in the ppc32 kernel that synchronizes the timebase
registers across an SMP powermac system does so by setting both timebases
to zero.  That is OK at boot but causes problems if done later.  So that we
can do hotplug CPU on these machines, this patch changes the code so it
reads the timebase from one CPU and transfers the value to the other CPU. 
(Hotplug CPU is needed for sleep (aka suspend to RAM) to work.)
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!