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>

Background: I've implemented 1K/2K page tables for s390.  These sub-page
page tables are required to properly support the s390 virtualization
instruction with KVM.  The SIE instruction requires that the page tables
have 256 page table entries (pte) followed by 256 page status table entries
(pgste).  The pgstes are only required if the process is using the SIE
instruction.  The pgstes are updated by the hardware and by the hypervisor
for a number of reasons, one of them is dirty and reference bit tracking.
To avoid wasting memory the standard pte table allocation should return
1K/2K (31/64 bit) and 2K/4K if the process is using SIE.

Problem: Page size on s390 is 4K, page table size is 1K or 2K.  That means
the s390 version for pte_alloc_one cannot return a pointer to a struct
page.  Trouble is that with the CONFIG_HIGHPTE feature on x86 pte_alloc_one
cannot return a pointer to a pte either, since that would require more than
32 bit for the return value of pte_alloc_one (and the pte * would not be
accessible since its not kmapped).

Solution: The only solution I found to this dilemma is a new typedef: a
pgtable_t.  For s390 pgtable_t will be a (pte *) - to be introduced with a
later patch.  For everybody else it will be a (struct page *).  The
additional problem with the initialization of the ptl lock and the
NR_PAGETABLE accounting is solved with a constructor pgtable_page_ctor and
a destructor pgtable_page_dtor.  The page table allocation and free
functions need to call these two whenever a page table page is allocated or
freed.  pmd_populate will get a pgtable_t instead of a struct page pointer.
 To get the pgtable_t back from a pmd entry that has been installed with
pmd_populate a new function pmd_pgtable is added.  It replaces the pmd_page
call in free_pte_range and apply_to_pte_range.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

(with Martin Schwidefsky <schwidefsky@de.ibm.com>)

The pgd/pud/pmd/pte page table allocation functions get a mm_struct pointer as
first argument.  The free functions do not get the mm_struct argument.  This
is 1) asymmetrical and 2) to do mm related page table allocations the mm
argument is needed on the free function as well.

[kamalesh@linux.vnet.ibm.com: i386 fix]
[akpm@linux-foundation.org: coding-syle fixes]
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NKamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In arch/powerpc/mm/pgtable_32.c, the variable io_bat_index and the
macro is_power_of_4() no longer have any users.  This removes them.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
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>

These old-fashioned IO mapping functions no longer have any callers in
code which remains relevant on arch/powerpc.  Therefore, this removes
them from arch/powerpc.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Mark pte_alloc_one_kernel as __init_refok to fix the following warning:

WARNING: arch/powerpc/mm/built-in.o(.text+0x1068): Section mismatch: reference to .init.text:early_get_page (between 'pte_alloc_one_kernel' and 'steal_context')
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

For 32-bit systems, powerpc still relies on the 4level-fixup.h hack,
to pretend that the generic pagetable handling stuff is 3-levels
rather than 4.  This patch removes this, instead using the newer
pgtable-nopmd.h to handle the elision of both the pud and pmd
pagetable levels (ppc32 pagetables are actually 2 levels).

This removes a little extraneous code, and makes it more easily
compared to the 64-bit pagetable code.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

32-bit powerpc systems define a macro, PHYS_FMT, giving a printf
format string fragment for displaying physical addresses, since most
32-bit powerpc platforms use 32-bit physical addresses but a few use
64-bit physical addresses.

This macro is used in exactly one place, a rare error message, where
we can solve the problem more simply by just unconditionally casting
the address up to 64-bit quantity before formatting it.

This patch does so, meaning that as we bring MMU definitions from
asm-ppc over to asm-powerpc, cleaning them up in the process, we don't
need to implement this ugly macro (which additionally has a very bad
name for something global).
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>

On hash table based 32 bits powerpc's, the hash management code runs with
a big spinlock. It's thus important that it never causes itself a hash
fault. That code is generally safe (it does memory accesses in real mode
among other things) with the exception of the actual access to the code
itself. That is, the kernel text needs to be accessible without taking
a hash miss exceptions.

This is currently guaranteed by having a BAT register mapping part of the
linear mapping permanently, which includes the kernel text. But this is
not true if using the "nobats" kernel command line option (which can be
useful for debugging) and will not be true when using DEBUG_PAGEALLOC
implemented in a subsequent patch.

This patch fixes this by pre-faulting in the hash table pages that hit
the kernel text, and making sure we never evict such a page under hash
pressure.
Signed-off-by: NBenjamin Herrenchmidt <benh@kernel.crashing.org>

 arch/powerpc/mm/hash_low_32.S |   22 ++++++++++++++++++++--
 arch/powerpc/mm/mem.c         |    3 ---
 arch/powerpc/mm/mmu_decl.h    |    4 ++++
 arch/powerpc/mm/pgtable_32.c  |   11 +++++++----
 4 files changed, 31 insertions(+), 9 deletions(-)
Signed-off-by: NPaul Mackerras <paulus@samba.org>

The 32 bits map_page() function is used internally by the mm code
for early mmu mappings and for ioremap. It should never be called
for an address that already has a valid PTE or hash entry, so we
add a BUG_ON for that and remove the useless flush_HPTE call.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

 arch/powerpc/mm/pgtable_32.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)
Signed-off-by: NPaul Mackerras <paulus@samba.org>

When building an 85xx kernel we get:

  CC      arch/powerpc/mm/pgtable_32.o
arch/powerpc/mm/pgtable_32.c: In function 'io_block_mapping':
arch/powerpc/mm/pgtable_32.c:330: error: expected identifier before '(' token
arch/powerpc/mm/pgtable_32.c:330: error: expected statement before ')' token

The is_power_of_2(x) fixup patch left an extra ')' on the is_power_of_4 macro.
There is a similiar issue on the arch/ppc side.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

Add the inline function "is_power_of_2()" to log2.h, where the value
zero is *not* considered to be a power of two.
Signed-off-by: NRobert P. J. Day <rpjday@mindspring.com>
Acked-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

powerpc: Merge 32 and 64 bits asm-powerpc/io.h

The rework on io.h done for the new hookable accessors made it easier,
so I just finished the work and merged 32 and 64 bits io.h for arch/powerpc.

arch/ppc still uses the old version in asm-ppc, there is just too much gunk
in there that I really can't be bothered trying to cleanup.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

In order to suppose platforms with devices above 4Gb on 32 bits platforms
with a >32 bits physical address space, we used to have a special ioremap64
along with a fixup routine fixup_bigphys_addr.

This shouldn't be necessary anymore as struct resource now supports 64 bits
addresses even on 32 bits archs. This patch enables that option when
CONFIG_PHYS_64BIT is set and removes ioremap64 and fixup_bigphys_addr.

This is a preliminary work for the upcoming merge of 32 and 64 bits io.h
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
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>

Fix 44x and BookE page fault handler to correctly lock PTE before
trying to pte_update() it, otherwise this PTE might be swapped out
after pte_present() check but before pte_uptdate() call, resulting in
corrupted PTE. This can happen with enabled preemption and low memory
condition.
Signed-off-by: NEugene Surovegin <ebs@ebshome.net>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

remove warnings when building a 64bit kernel.
smp_call_function triggers also with 32bit kernel.

WARNING: vmlinux: duplicate symbol 'smp_call_function' previous definition was in vmlinux
arch/powerpc/kernel/ppc_ksyms.c:164:EXPORT_SYMBOL(smp_call_function);
arch/powerpc/kernel/smp.c:300:EXPORT_SYMBOL(smp_call_function);

WARNING: vmlinux: duplicate symbol 'ioremap' previous definition was in vmlinux
arch/powerpc/kernel/ppc_ksyms.c:113:EXPORT_SYMBOL(ioremap);
arch/powerpc/mm/pgtable_64.c:321:EXPORT_SYMBOL(ioremap);

WARNING: vmlinux: duplicate symbol '__ioremap' previous definition was in vmlinux
arch/powerpc/kernel/ppc_ksyms.c:117:EXPORT_SYMBOL(__ioremap);
arch/powerpc/mm/pgtable_64.c:322:EXPORT_SYMBOL(__ioremap);

WARNING: vmlinux: duplicate symbol 'iounmap' previous definition was in vmlinux
arch/powerpc/kernel/ppc_ksyms.c:118:EXPORT_SYMBOL(iounmap);
arch/powerpc/mm/pgtable_64.c:323:EXPORT_SYMBOL(iounmap);
Signed-off-by: NOlaf Hering <olh@suse.de>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

... namely, the change to the 2-argument pte_alloc_kernel.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This applies the same fix as Al Viro recently made to
arch/ppc/mm/pgtable.c.
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 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>

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>

CONFIG_PTE_64BIT & CONFIG_PHYS_64BIT are not currently consistently used in
the code base.  Fixed up the usage such that CONFIG_PTE_64BIT is used when we
have a 64-bit PTE regardless of physical address width.  CONFIG_PHYS_64BIT is
used if the physical address width is larger than 32-bits, regardless of PTE
size.

These changes required a few sub-arch specific ifdef's to be fixed and the
introduction of a physical address format string.
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!