Added support to allow an 85xx kernel to be run from a non-zero physical
address (useful for cooperative asymmetric multiprocessing situations and
kdump).  The support can be configured at compile time by setting
CONFIG_PAGE_OFFSET, CONFIG_KERNEL_START, and CONFIG_PHYSICAL_START as
desired.

Alternatively, the kernel build can set CONFIG_RELOCATABLE.  Setting this
config option causes the kernel to determine at runtime the physical
addresses of CONFIG_PAGE_OFFSET and CONFIG_KERNEL_START.  If
CONFIG_RELOCATABLE is set, then CONFIG_PHYSICAL_START has no meaning.
However, CONFIG_PHYSICAL_START will always be used to set the LOAD program
header physical address field in the resulting ELF image.

Currently we are limited to running at a physical address that is a
multiple of 256M.  This is due to how we map TLBs to cover
lowmem.  This should be fixed to allow 64M or maybe even 16M alignment
in the future.  It is considered an error to try and run a kernel at a
non-aligned physical address.

All the magic for this support is accomplished by proper initialization
of the kernel memory subsystem and use of ARCH_PFN_OFFSET.

The use of ARCH_PFN_OFFSET only affects normal memory and not IO mappings.
ioremap uses map_page and isn't affected by ARCH_PFN_OFFSET.

/dev/mem continues to allow access to any physical address in the system
regardless of how CONFIG_PHYSICAL_START is set.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

We always use __initial_memory_limit as an address so rename it
to be clear.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

* Determine the RPN we are running the kernel at runtime rather
  than using compile time constant for initial TLB

* Cleanup adjust_total_lowmem() to respect memstart_addr and
  be a bit more clear on variables that are sizes vs addresses.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

A number of users of PPC_MEMSTART (40x, ppc_mmu_32) can just always
use 0 as we don't support booting these kernels at non-zero physical
addresses since their exception vectors must be at 0 (or 0xfffx_xxxx).

For the sub-arches that support relocatable interrupt vectors
(book-e), it's reasonable to have memory start at a non-zero physical
address.  For those cases use the variable memstart_addr instead of
the #define PPC_MEMSTART since the only uses of PPC_MEMSTART are for
initialization and in the future we can set memstart_addr at runtime
to have a relocatable kernel.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

The e500 MMU init code previously assumed KERNELBASE always equaled
PAGE_OFFSET and PHYSICAL_START was 0.  This is useful for kdump
support as well as asymetric multicore.

For the initial kdump support the secondary kernel will run at 32M
but need access to all of memory so we bump the initial TLB up to
64M.  This also matches with the forth coming ePAPR spec.
Signed-off-by: NDale Farnsworth <dale@farnsworth.org>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

The CONFIG_FSL_BOOKE mmu setup code fails when CONFIG_HIGHMEM=y
and the 3 fixed TLB entries cannot exactly map the lowmem size.
Each TLB entry can map 4MB, 16MB, 64MB or 256MB, so the failure
is observed when the kernel lowmem size is not equal to the
sum of up to 3 of those values.

Normally, memory is sized in nice numbers, but I observed this
problem while testing a crash dump kernel.  The failure can
also be observed by artificially reducing the kernel's main
memory via the mem= kernel command line parameter.

This commit fixes the problem by setting __initial_memory_limit
in adjust_total_lowmem().
Signed-off-by: NDale Farnsworth <dale@farnsworth.org>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

APUS (the Amiga Power-Up System) is not supported under arch/powerpc
and it's unlikely it ever will be.  Therefore, this patch removes the
fragments of APUS support code from arch/powerpc which have been
copied from arch/ppc.

A few APUS references are left in asm-powerpc in .h files which are
still used from arch/ppc.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

Changed jobs and the Freescale address is no longer valid.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.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>

Continue the Good Fight:  Limit bootmem.h include creep.
Signed-off-by: NJon Loeliger <jdl@freescale.com>
Signed-off-by: NKumar Gala <kumar.gala@freescale.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The e200 core is a Book-E core (similar to e500) that has a unified L1 cache
and is not cache coherent on the bus.  The e200 core also adds a separate
exception level for debug exceptions.  Part of this patch helps to cleanup a
few cases that are true for all Freescale Book-E parts, not just e500.
Signed-off-by: NKim Phillips <kim.phillips@freescale.com>
Signed-off-by: NKumar Gala <kumar.gala@freescale.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Made the number of TLB CAM entries private and converted the board
consumers to use num_tlbcam_entries which is setup at boot time from
configuration registers.  This way the only consumers of the #define
NUM_TLBCAMS are the arrays used to manage the TLB.
Signed-off-by: NKumar Gala <kumar.gala@freescale.com>
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!