The fixmap code from x86 allows us to have compile time virtual addresses
that we change the physical addresses of at run time.

This is useful for applications like kmap_atomic, PCI config that is done
via direct memory map, kexec/kdump.

We got ride of CONFIG_HIGHMEM_START as we can now determine a more optimal
location for PKMAP_BASE based on where the fixmap addresses start and
working back from there.

Additionally, the kmap code in asm-powerpc/highmem.h always had debug
enabled.  Moved to using CONFIG_DEBUG_HIGHMEM to determine if we should
have the extra debug checking.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

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>

When we moved to arch/powerpc we actively tried to avoid using the
ppc_md.setup_io_mappings().  Currently no board ports use it so let's
remove it to avoid any new boards using it.

Also, remove early_serial_map() since we don't even have a call out for
it in arch/powerpc.
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>

total_lowmem represents the amount of low memory, not the physical
address that low memory ends at.  If the start of memory is at 0 it
happens that total_lowmem can be used as both the size and the address
that lowmem ends at (or more specifically one byte beyond the end).

To make the code a bit more clear and deal with the case when the start of
memory isn't at physical 0, we introduce lowmem_end_addr that represents
one byte beyond the last physical address in the lowmem region.
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>

__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The 8xx can only support a max of 8M during early boot (it seems a lot of
8xx boards only have 8M so the bug was never triggered), but the early
allocator isn't aware of this.  The following change makes it able to run
with larger memory.
Signed-off-by: NJohn Traill <john.traill@freescale.com>
Signed-off-by: NVitaly Bordug <vitb@kernel.crashing.org>
Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

The entries are only 32-bit, so restrict the virtual address to stay
below 0xffff_ffff.  With KERNELBASE set to 0xc000_0000, this in effect
restricts access to the first 1GB of real memory.

Make setup_kcore conditional on CONFIG_PROC_KCORE for both 32/64.
Signed-off-by: NEd Swarthout <Ed.Swarthout@freescale.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This removes several duplicate includes from arch/powerpc/.
Signed-off-by: NJesper Juhl <jesper.juhl@gmail.com>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.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>

Here's an implementation of DEBUG_PAGEALLOC for ppc32. It disables BAT
mapping and is only tested with Hash table based processor though it
shouldn't be too hard to adapt it to others.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

 arch/powerpc/Kconfig.debug       |    9 ++++++
 arch/powerpc/mm/init_32.c        |    4 +++
 arch/powerpc/mm/pgtable_32.c     |   52 +++++++++++++++++++++++++++++++++++++++
 arch/powerpc/mm/ppc_mmu_32.c     |    4 ++-
 include/asm-powerpc/cacheflush.h |    6 ++++
 5 files changed, 74 insertions(+), 1 deletion(-)
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>

set_page_count usage outside mm/ is limited to setting the refcount to 1.
Remove set_page_count from outside mm/, and replace those users with
init_page_count() and set_page_refcounted().

This allows more debug checking, and tighter control on how code is allowed
to play around with page->_count.
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch unifies udbg for both ppc32 and ppc64 when building the
merged achitecture. xmon now has a single "back end". The powermac udbg
stuff gets enriched with some ADB capabilities and btext output. In
addition, the early_init callback is now called on ppc32 as well,
approx. in the same order as ppc64 regarding device-tree manipulations.
The init sequences of ppc32 and ppc64 are getting closer, I'll unify
them in a later patch.

For now, you can force udbg to the scc using "sccdbg" or to btext using
"btextdbg" on powermacs. I'll implement a cleaner way of forcing udbg
output to something else than the autodetected OF output device in a
later patch.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This also make klimit have the same type on 32-bit as on 64-bit,
namely unsigned long, and defines and initializes it in one place.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

With ARCH=powerpc we assume the presence of a device tree, so we don't
require any support for the old bi_recs method of passing boot
parameters.  Likewise, we've never needed it for ppc64, but we still
had an include/asm-ppc64/bootinfo.h from which nothing was used.  This
patch removes that file, and all references to it in arch/ppc64 and
arch/powerpc.  A related, unused variable 'boot_mem_size' is also
removed from setup_32.c.  The bootinfo stuff remains in ARCH=ppc for
the time being.

Built and booted on Power5 (ARCH=ppc64 and ARCH=powerpc), built for
32-bit powermac (ARCH=powerpc and ARCH=ppc).
Signed-off-by: NDavid Gibson <dwg@au1.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This trims off the extra unusable memory from the lmb structure,
so we don't try to use it.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

... instead of exporting it in arch/*/kernel/ppc_ksyms.c.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

We were initializing the btext stuff from prom_init(), thus breaking
the rule that all communication between prom_init() and the rest of
the kernel has to be via the flattened device tree.  This removes
the btext initialization calls from prom_init() and initializes it
instead after the device tree is unflattened.  It would be nice to
do it earlier, but that needs some more infrastructure to find the
properties we need in the flattened device tree.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This doesn't change any code, just renames things so we consistently
have foo_32.c and foo_64.c where we have separate 32- and 64-bit
versions.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This also creates merged versions of do_init_bootmem, paging_init
and mem_init and moves them to arch/powerpc/mm/mem.c.  It gets rid
of the mem_pieces stuff.

I made memory_limit a parameter to lmb_enforce_memory_limit rather
than a global referenced by that function.  This will require some
small changes to ppc64 if we want to continue building ARCH=ppc64
using the merged lmb.c.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This merges ppc_ksyms.c, puts back the actual do_execve call in
sys_execve, makes init_MMU call find_end_of_memory rather than
ppc_md.find_end_of_memory (every platform has a device tree
with a /memory node now, right?) and fixes some problems with the
mpic initialization on newworld powermacs.
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>

Here is the default configuration for Marvell EV64360BP board.  It has been
tested on the board.
Signed-off-by: NLee Nicks <allinux@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

flush_dcache_icache_page() will be called on an instruction page fault.  We
can't sleep in the fault handler, so use kmap_atomic() instead of just
kmap() for the Book-E case.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>
Acked-by: NMatt Porter <mporter@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

On 8xx, in the case where a pagefault happens for a process who's not
the owner of the vma in question (ptrace for instance), the flush
operation is performed via the physical address.

Unfortunately, that results in a strange, unexplainable "icbi"
instruction fault, most likely due to a CPU bug (see oops below).

Avoid that by flushing the page via its kernel virtual address.

Oops: kernel access of bad area, sig: 11 [#2]
NIP: C000543C LR: C000B060 SP: C0F35DF0 REGS: c0f35d40 TRAP: 0300 Not tainted
MSR: 00009022 EE: 1 PR: 0 FP: 0 ME: 1 IR/DR: 10
DAR: 00000010, DSISR: C2000000
TASK = c0ea8430[761] 'gdbserver' THREAD: c0f34000
Last syscall: 26
GPR00: 00009022 C0F35DF0 C0EA8430 00F59000 00000100 FFFFFFFF 00F58000
00000001
GPR08: C021DAEF C0270000 00009032 C0270000 22044024 10025428 01000800
00000001
GPR16: 007FFF3F 00000001 00000000 7FBC6AC0 00F61022 00000001 C0839300
C01E0000
GPR24: 00CD0889 C082F568 3000AC18 C02A7A00 C0EA15C8 00F588A9 C02ACB00
C02ACB00
NIP [c000543c] __flush_dcache_icache_phys+0x38/0x54
LR [c000b060] flush_dcache_icache_page+0x20/0x30
Call trace:
[c000b154] update_mmu_cache+0x7c/0xa4
[c005ae98] do_wp_page+0x460/0x5ec
[c005c8a0] handle_mm_fault+0x7cc/0x91c
[c005ccec] get_user_pages+0x2fc/0x65c
[c0027104] access_process_vm+0x9c/0x1d4
[c00076e0] sys_ptrace+0x240/0x4a4
[c0002bd0] ret_from_syscall+0x0/0x44
Signed-off-by: NMarcelo Tosatti <marcelo.tosatti@cyclades.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The proposed _tlbie call at update_mmu_cache() is safe because:

Addresses for which update_mmu_cache() gets invocated are never inside the
static kernel virtual mapping, meaning that there is no risk for the
_tlbie() here to be thrashing the pinned entry, as Dan suspected.

The intermediate TLB state in which this bug can be triggered is not
visible by userspace or any other contexts, except the page fault handling
path.  So there is no need to worry about userspace dcbxxx users.

The other solution to this is to avoid dcbst misbehaviour in the first
place, which involves changing in-kernel "dcbst" callers to use 8xx
specific SPR's.

Summary:

On 8xx, cache control instructions (particularly "dcbst" from
flush_dcache_icache) fault as write operation if there is an unpopulated
TLB entry for the address in question.  To workaround that, we invalidate
the TLB here, thus avoiding dcbst misbehaviour.
Signed-off-by: NMarcelo Tosatti <marcelo.tosatti@cyclades.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch kills the whole embedded System.map mecanism and the
bootloader-passed System.map that was used to provide symbol resolution in
xmon.  Instead, xmon now uses kallsyms like ppc64 does.

No hurry getting that in Linus tree, let it be tested in -mm for a while
first and make sure it doesn't break various embedded configs.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Remove PG_highmem, to save a page flag.  Use is_highmem() instead.  It'll
generate a little more code, but we don't use PageHigheMem() in many places.
Signed-off-by: NBadari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

On ppc32, the platform code can supply a "progress" function that is
used to show progress through the boot.  These functions are usually
in an init section and so can't be called after the init pages are
freed.  Now that the cpu bringup code can be called after the system
is booted (for hotplug cpu) we can get the situation where the
progress function can be called after boot.  The simple fix is to set
the progress function pointer to NULL when the init pages are freed,
and that is what this patch does (note that all callers already check
whether the function pointer is NULL before trying to call it).
Signed-off-by: NPaul Mackerras <paulus@samba.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!