This has become necessary with chips that support more than 43-bits
of physical addressing.

Based almost entirely upon a patch by Bob Picco.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Acked-by: NBob Picco <bob.picco@oracle.com>

Drop extern for all prototypes and adjust alignment of parameters
as required after the removal.
In a few rare cases adjust linelength to conform to maximum 80 chars,
and likewise in a few rare cases adjust alignment of parameters
to static functions.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is relatively easy since PMD's now cover exactly 4MB of memory.

Our PMD entries are 32-bits each, so we use a special encoding.  The
lowest bit, PMD_ISHUGE, determines the interpretation.  This is possible
because sparc64's page tables are purely software entities so we can use
whatever encoding scheme we want.  We just have to make the TLB miss
assembler page table walkers aware of the layout.

set_pmd_at() works much like set_pte_at() but it has to operate in two
page from a table of non-huge PTEs, so we have to queue up TLB flushes
based upon what mappings are valid in the PTE table.  In the second regime
we are going from huge-page to non-huge-page, and in that case we need
only queue up a single TLB flush to push out the huge page mapping.

We still have 5 bits remaining in the huge PMD encoding so we can very
likely support any new pieces of THP state tracking that might get added
in the future.

With lots of help from Johannes Weiner.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We've split up the PTE tables so that they take up half a page instead of
a full page.  This is in order to facilitate transparent huge page
support, which works much better if our PMDs cover 4MB instead of 8MB.

What we do is have a one-behind cache for PTE table allocations in the
mm struct.

This logic triggers only on allocations.  For example, we don't try to
keep track of free'd up page table blocks in the style that the s390 port
does.

There were only two slightly annoying aspects to this change:

1) Changing pgtable_t to be a "pte_t *".  There's all of this special
   logic in the TLB free paths that needed adjustments, as did the
   PMD populate interfaces.

2) init_new_context() needs to zap the pointer, since the mm struct
   just gets copied from the parent on fork.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Make use of the generic RCU page table freeing on Sparc64, doing so allows
for race-free software page-table walkers like gup_fast().
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With the recent mmu_gather changes that included generic RCU freeing of
page-tables, it is now quite straightforward to implement gup_fast() on
sparc64.

This patch:

Remove the page table quicklists.  They are pointless and make it harder
to use RCU page table freeing and share code with other architectures.

BTW, this is the second time this has happened, see commit 3c936465
("[SPARC64]: Kill pgtable quicklists and use SLAB.")
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Rework the sparc mmu_gather usage to conform to the new world order :-)

Sparc mmu_gather does two things:
 - tracks vaddrs to unhash
 - tracks pages to free

Split these two things like powerpc has done and keep the vaddrs
in per-cpu data structures and flush them on context switch.

The remaining bits can then use the generic mmu_gather.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NDavid Miller <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Tony Luck <tony.luck@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The majority of this patch was created by the following script:

***
ASM=arch/sparc/include/asm
mkdir -p $ASM
git mv include/asm-sparc64/ftrace.h $ASM
git rm include/asm-sparc64/*
git mv include/asm-sparc/* $ASM
sed -ie 's/asm-sparc64/asm/g' $ASM/*
sed -ie 's/asm-sparc/asm/g' $ASM/*
***

The rest was an update of the top-level Makefile to use sparc
for header files when sparc64 is being build.
And a small fixlet to pick up the correct unistd.h from
sparc64 code.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

With this commit all sparc64 header files are moved to asm-sparc.
The remaining files (71 files) were too different to be trivially
merged so divide them up in a _32.h and a _64.h file which
are both included from the file with no bit size.

The following script were used:
cd include
FILES=`wc -l asm-sparc64/*h | grep -v '^     1' | cut -b 20-`

for FILE in ${FILES}; do
  echo $FILE:
  BASE=`echo $FILE | cut -d '.' -f 1`
  FN32=${BASE}_32.h
  FN64=${BASE}_64.h
  GUARD=___ASM_SPARC_`echo $BASE | tr '-' '_' | tr [:lower:] [:upper:]`_H
  git mv asm-sparc/$FILE asm-sparc/$FN32
  git mv asm-sparc64/$FILE asm-sparc/$FN64
  echo git mv done
  printf "#ifndef %s\n" $GUARD                             >   asm-sparc/$FILE
  printf "#define %s\n" $GUARD                             >>  asm-sparc/$FILE
  printf "#if defined(__sparc__) && defined(__arch64__)\n" >>  asm-sparc/$FILE
  printf "#include <asm-sparc/%s>\n" $FN64                 >>  asm-sparc/$FILE
  printf "#else\n"                                         >>  asm-sparc/$FILE
  printf "#include <asm-sparc/%s>\n" $FN32                 >>  asm-sparc/$FILE
  printf "#endif\n"                                        >>  asm-sparc/$FILE
  printf "#endif\n"                                        >>  asm-sparc/$FILE
  git add asm-sparc/$FILE
  echo new file done
  printf "#include <asm-sparc/%s>\n" $FILE                 >  asm-sparc64/$FILE
  git add asm-sparc64/$FILE
  echo sparc64 file done
done

The guard contains three '_' to avoid conflict with existing guards.
In additing the two Kbuild files are emptied to avoid breaking
headers_* targets.
We will reintroduce the exported header files when the necessary
kbuild changes are merged.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch removes the CVS keywords that weren't updated for a long time
from comments.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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>

I ported this to sparc64 as per the patch below, tested on UP SunBlade1500 and
24 cpu Niagara T1000.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Andi Kleen <ak@suse.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: William Lee Irwin III <wli@holomorphy.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Replace all uses of kmem_cache_t with struct kmem_cache.

The patch was generated using the following script:

	#!/bin/sh
	#
	# Replace one string by another in all the kernel sources.
	#

	set -e

	for file in `find * -name "*.c" -o -name "*.h"|xargs grep -l $1`; do
		quilt add $file
		sed -e "1,\$s/$1/$2/g" $file >/tmp/$$
		mv /tmp/$$ $file
		quilt refresh
	done

The script was run like this

	sh replace kmem_cache_t "struct kmem_cache"
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Taking a nod from the powerpc port.

With the per-cpu caching of both the page allocator and SLAB, the
pgtable quicklist scheme becomes relatively silly and primitive.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Unlike the virtual page tables, the new TSB scheme does not
require this ugly hack.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We now use the TSB hardware assist features of the UltraSPARC
MMUs.

SMP is currently knowingly broken, we need to find another place
to store the per-cpu base pointers.  We hid them away in the TSB
base register, and that obviously will not work any more :-)

Another known broken case is non-8KB base page size.

Also noticed that flush_tlb_all() is not referenced anywhere, only
the internal __flush_tlb_all() (local cpu only) is used by the
sparc64 port, so we can get rid of flush_tlb_all().

The kernel gets it's own 8KB TSB (swapper_tsb) and each address space
gets it's own private 8K TSB.  Later we can add code to dynamically
increase the size of per-process TSB as the RSS grows.  An 8KB TSB is
good enough for up to about a 4MB RSS, after which the TSB starts to
incur many capacity and conflict misses.

We even accumulate OBP translations into the kernel TSB.

Another area for refinement is large page size support.  We could use
a secondary address space TSB to handle those.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This showed that arch/sparc64/kernel/ptrace.c was not getting
the define properly, and thus the code protected by this ifdef
was never actually compiled before.  So fix that too.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

warning: untested, but it there's not too much chance for screwups
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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!