call split_mem_range inside the function.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1353123563-3103-7-git-send-email-yinghai@kernel.orgSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

After

| commit 8548c84d
| Author: Takashi Iwai <tiwai@suse.de>
| Date:   Sun Oct 23 23:19:12 2011 +0200
|
|    x86: Fix S4 regression
|
|    Commit 4b239f45 ("x86-64, mm: Put early page table high") causes a S4
|    regression since 2.6.39, namely the machine reboots occasionally at S4
|    resume.  It doesn't happen always, overall rate is about 1/20.  But,
|    like other bugs, once when this happens, it continues to happen.
|
|    This patch fixes the problem by essentially reverting the memory
|    assignment in the older way.

Have some page table around 512M again, that will prevent kdump to find 512M
under 768M.

We need revert that reverting, so we could put page table high again for 64bit.

Takashi agreed that S4 regression could be something else.

	https://lkml.org/lkml/2012/6/15/182Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1353123563-3103-6-git-send-email-yinghai@kernel.orgSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Now init_memory_mapping is called two times, later will be called for every
ram ranges.

Could put all related init_mem calling together and out of setup.c.

Actually, it reverts commit 1bbbbe77
    x86: Exclude E820_RESERVED regions and memory holes above 4 GB from direct mapping.
will address that later with complete solution include handling hole under 4g.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1353123563-3103-5-git-send-email-yinghai@kernel.orgReviewed-by: NPekka Enberg <penberg@kernel.org>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

It will need to call split_mem_range().
Move it down after that to avoid extra declaration.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1353123563-3103-4-git-send-email-yinghai@kernel.orgSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

So make init_memory_mapping smaller and readable.

-v2: use 0 instead of nr_range as input parameter found by Yasuaki Ishimatsu.
Suggested-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1353123563-3103-3-git-send-email-yinghai@kernel.orgReviewed-by: NPekka Enberg <penberg@kernel.org>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Now we pass around use_gbpages and use_pse for calculating page table size,
Later we will need to call init_memory_mapping for every ram range one by one,
that mean those calculation will be done several times.

Those information are the same for all ram range and could be stored in
page_size_mask and could be probed it one time only.

Move that probing code out of init_memory_mapping into separated function
probe_page_size_mask(), and call it before all init_memory_mapping.
Suggested-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1353123563-3103-2-git-send-email-yinghai@kernel.orgReviewed-by: NPekka Enberg <penberg@kernel.org>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Commit

    844ab6f9 x86, mm: Find_early_table_space based on ranges that are actually being mapped

added back some lines back wrongly that has been removed in commit

    7b16bbf9 Revert "x86/mm: Fix the size calculation of mapping tables"

remove them again.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/CAE9FiQW_vuaYQbmagVnxT2DGsYc=9tNeAbdBq53sYkitPOwxSQ@mail.gmail.comAcked-by: NJacob Shin <jacob.shin@amd.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Current logic finds enough space for direct mapping page tables from 0
to end. Instead, we only need to find enough space to cover mr[0].start
to mr[nr_range].end -- the range that is actually being mapped by
init_memory_mapping()

This is needed after 1bbbbe77, to address
the panic reported here:

  https://lkml.org/lkml/2012/10/20/160
  https://lkml.org/lkml/2012/10/21/157Signed-off-by: NJacob Shin <jacob.shin@amd.com>
Link: http://lkml.kernel.org/r/20121024195311.GB11779@jshin-ToonieTested-by: NTom Rini <trini@ti.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Commit:

   722bc6b1 x86/mm: Fix the size calculation of mapping tables

Tried to address the issue that the first 2/4M should use 4k pages
if PSE enabled, but extra counts should only be valid for x86_32.

This commit caused a kdump regression: the kdump kernel hangs.

Work is in progress to fundamentally fix the various page table
initialization issues that we have, via the design suggested
by H. Peter Anvin, but it's not ready yet to be merged.

So, to get a working kdump revert to the last known working version,
which is the revert of this commit and of a followup fix (which was
incomplete):

   bd2753b2 x86/mm: Only add extra pages count for the first memory range during pre-allocation

Tested kdump on physical and virtual machines.
Signed-off-by: NDave Young <dyoung@redhat.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Acked-by: NCong Wang <xiyou.wangcong@gmail.com>
Acked-by: NFlavio Leitner <fbl@redhat.com>
Tested-by: NFlavio Leitner <fbl@redhat.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Flavio Leitner <fbl@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: ianfang.cn@gmail.com
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@kernel.org>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Fixing an off-by-one error in devmem_is_allowed(), which allows
accesses to physical addresses 0x100000-0x100fff, an extra page
past 1MB.
Signed-off-by: NT Makphaibulchoke <tmac@hp.com>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Cc: yinghai@kernel.org
Cc: tiwai@suse.de
Cc: dhowells@redhat.com
Link: http://lkml.kernel.org/r/1346210503-14276-1-git-send-email-tmac@hp.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

... matching various other architectures.
Signed-off-by: NJan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/4FDF1F5C020000780008A661@nat28.tlf.novell.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

x86/mm: Only add extra pages count for the first memory range during pre-allocation early page table space

Robin found this regression:

| I just tried to boot an 8TB system.  It fails very early in boot with:
| Kernel panic - not syncing: Cannot find space for the kernel page tables

git bisect commit 722bc6b1.

A git revert of that commit does boot past that point on the 8TB
configuration.

That commit will add up extra pages for all memory range even
above 4g.

Try to limit that extra page count adding to first entry only.
Bisected-by: NRobin Holt <holt@sgi.com>
Tested-by: NRobin Holt <holt@sgi.com>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/CAE9FiQUj3wyzQxtq9yzBNc9u220p8JZ1FYHG7t%3DMOzJ%3D9BZMYA@mail.gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Print physical address info in a style consistent with the %pR style used
elsewhere in the kernel.  For example:

    -found SMP MP-table at [ffff8800000fce90] fce90
    +found SMP MP-table at [mem 0x000fce90-0x000fce9f] mapped at [ffff8800000fce90]
    -initial memory mapped : 0 - 20000000
    +initial memory mapped: [mem 0x00000000-0x1fffffff]
    -Base memory trampoline at [ffff88000009c000] 9c000 size 8192
    +Base memory trampoline [mem 0x0009c000-0x0009dfff] mapped at [ffff88000009c000]
    -SRAT: Node 0 PXM 0 0-80000000
    +SRAT: Node 0 PXM 0 [mem 0x00000000-0x7fffffff]
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Disintegrate asm/system.h for X86.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
cc: x86@kernel.org

For machines that enable PSE, the first 2/4M memory region still uses
4K pages, so needs more PTEs in this case, but
find_early_table_space() doesn't count this.

This patch fixes it.

The bug was found via code review, no misbehavior of the kernel
was observed.
Signed-off-by: NWANG Cong <xiyou.wangcong@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: <ianfang.cn@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-kq6a00qe33h7c7ais2xsywnh@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>

Now that zone_sizes_init() is identical on 32-bit and 64-bit,
move the code to arch/x86/mm/init.c and use it for both
architectures.
Acked-by: NTejun Heo <tj@kernel.org>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NPekka Enberg <penberg@kernel.org>
Link: http://lkml.kernel.org/r/1320155902-10424-7-git-send-email-penberg@kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>

Commit 4b239f45 ("x86-64, mm: Put early page table high") causes a S4
regression since 2.6.39, namely the machine reboots occasionally at S4
resume.  It doesn't happen always, overall rate is about 1/20.  But,
like other bugs, once when this happens, it continues to happen.

This patch fixes the problem by essentially reverting the memory
assignment in the older way.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Cc: <stable@kernel.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Yinghai Lu <yinghai.lu@oracle.com>
[ We'll hopefully find the real fix, but that's too late for 3.1 now ]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Other than sanity check and debug message, the x86 specific version of
memblock reserve/free functions are simple wrappers around the generic
versions - memblock_reserve/free().

This patch adds debug messages with caller identification to the
generic versions and replaces x86 specific ones and kills them.
arch/x86/include/asm/memblock.h and arch/x86/mm/memblock.c are empty
after this change and removed.
Signed-off-by: NTejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/1310462166-31469-14-git-send-email-tj@kernel.org
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

25818f0f (memblock: Make MEMBLOCK_ERROR be 0) thankfully made
MEMBLOCK_ERROR 0 and there already are codes which expect error return
to be 0.  There's no point in keeping MEMBLOCK_ERROR around.  End its
misery.
Signed-off-by: NTejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/1310457490-3356-6-git-send-email-tj@kernel.org
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Fold all the mmu_gather rework patches into one for submission
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Reported-by: NHugh Dickins <hughd@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
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: 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>

With CONFIG_DEBUG_SECTION_MISMATCH=y I see these warnings in next-20110415:

  LD      vmlinux.o
  MODPOST vmlinux.o
WARNING: vmlinux.o(.text+0x1ba48): Section mismatch in reference from the function native_pagetable_reserve() to the function .init.text:memblock_x86_reserve_range()
The function native_pagetable_reserve() references
the function __init memblock_x86_reserve_range().
This is often because native_pagetable_reserve lacks a __init
annotation or the annotation of memblock_x86_reserve_range is wrong.

This patch fixes the issue.
Thanks to pipacs from PaX project for help on IRC.
Acked-by: N"H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NSedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Introduce a new x86_init hook called pagetable_reserve that at the end
of init_memory_mapping is used to reserve a range of memory addresses for
the kernel pagetable pages we used and free the other ones.

On native it just calls memblock_x86_reserve_range while on xen it also
takes care of setting the spare memory previously allocated
for kernel pagetable pages from RO to RW, so that it can be used for
other purposes.

A detailed explanation of the reason why this hook is needed follows.

As a consequence of the commit:

commit 4b239f45
Author: Yinghai Lu <yinghai@kernel.org>
Date:   Fri Dec 17 16:58:28 2010 -0800

    x86-64, mm: Put early page table high

at some point init_memory_mapping is going to reach the pagetable pages
area and map those pages too (mapping them as normal memory that falls
in the range of addresses passed to init_memory_mapping as argument).
Some of those pages are already pagetable pages (they are in the range
pgt_buf_start-pgt_buf_end) therefore they are going to be mapped RO and
everything is fine.
Some of these pages are not pagetable pages yet (they fall in the range
pgt_buf_end-pgt_buf_top; for example the page at pgt_buf_end) so they
are going to be mapped RW.  When these pages become pagetable pages and
are hooked into the pagetable, xen will find that the guest has already
a RW mapping of them somewhere and fail the operation.
The reason Xen requires pagetables to be RO is that the hypervisor needs
to verify that the pagetables are valid before using them. The validation
operations are called "pinning" (more details in arch/x86/xen/mmu.c).

In order to fix the issue we mark all the pages in the entire range
pgt_buf_start-pgt_buf_top as RO, however when the pagetable allocation
is completed only the range pgt_buf_start-pgt_buf_end is reserved by
init_memory_mapping. Hence the kernel is going to crash as soon as one
of the pages in the range pgt_buf_end-pgt_buf_top is reused (b/c those
ranges are RO).

For this reason we need a hook to reserve the kernel pagetable pages we
used and free the other ones so that they can be reused for other
purposes.
On native it just means calling memblock_x86_reserve_range, on Xen it
also means marking RW the pagetable pages that we allocated before but
that haven't been used before.

Another way to fix this is without using the hook is by adding a 'if
(xen_pv_domain)' in the 'init_memory_mapping' code and calling the Xen
counterpart, but that is just nasty.
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

e820_table_{start|end|top}, which are used to buffer page table
allocation during early boot, are now derived from memblock and don't
have much to do with e820.  Change the names so that they reflect what
they're used for.

This patch doesn't introduce any behavior change.

-v2: Ingo found that earlier patch "x86: Use early pre-allocated page
     table buffer top-down" caused crash on 32bit and needed to be
     dropped.  This patch was updated to reflect the change.

-tj: Updated commit description.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NTejun Heo <tj@kernel.org>

It is not related to init_memory_mapping(),  and init_memory_mapping() is
getting more bigger.

So make it as seperated function and call it from reserve_brk() and that is
point when _brk_end is concluded.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
LKML-Reference: <4D1933E0.7090305@kernel.org>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Introduce init_memory_mapping_high(), and use it with 64bit.

It will go with every memory segment above 4g to create page table to the
memory range itself.

before this patch all page tables was on one node.

with this patch, one RED-PEN is killed

debug out for 8 sockets system after patch
[    0.000000] initial memory mapped : 0 - 20000000
[    0.000000] init_memory_mapping: [0x00000000000000-0x0000007f74ffff]
[    0.000000]  0000000000 - 007f600000 page 2M
[    0.000000]  007f600000 - 007f750000 page 4k
[    0.000000] kernel direct mapping tables up to 7f750000 @ [0x7f74c000-0x7f74ffff]
[    0.000000] RAMDISK: 7bc84000 - 7f745000
....
[    0.000000] Adding active range (0, 0x10, 0x95) 0 entries of 3200 used
[    0.000000] Adding active range (0, 0x100, 0x7f750) 1 entries of 3200 used
[    0.000000] Adding active range (0, 0x100000, 0x1080000) 2 entries of 3200 used
[    0.000000] Adding active range (1, 0x1080000, 0x2080000) 3 entries of 3200 used
[    0.000000] Adding active range (2, 0x2080000, 0x3080000) 4 entries of 3200 used
[    0.000000] Adding active range (3, 0x3080000, 0x4080000) 5 entries of 3200 used
[    0.000000] Adding active range (4, 0x4080000, 0x5080000) 6 entries of 3200 used
[    0.000000] Adding active range (5, 0x5080000, 0x6080000) 7 entries of 3200 used
[    0.000000] Adding active range (6, 0x6080000, 0x7080000) 8 entries of 3200 used
[    0.000000] Adding active range (7, 0x7080000, 0x8080000) 9 entries of 3200 used
[    0.000000] init_memory_mapping: [0x00000100000000-0x0000107fffffff]
[    0.000000]  0100000000 - 1080000000 page 2M
[    0.000000] kernel direct mapping tables up to 1080000000 @ [0x107ffbd000-0x107fffffff]
[    0.000000]     memblock_x86_reserve_range: [0x107ffc2000-0x107fffffff]          PGTABLE
[    0.000000] init_memory_mapping: [0x00001080000000-0x0000207fffffff]
[    0.000000]  1080000000 - 2080000000 page 2M
[    0.000000] kernel direct mapping tables up to 2080000000 @ [0x207ff7d000-0x207fffffff]
[    0.000000]     memblock_x86_reserve_range: [0x207ffc0000-0x207fffffff]          PGTABLE
[    0.000000] init_memory_mapping: [0x00002080000000-0x0000307fffffff]
[    0.000000]  2080000000 - 3080000000 page 2M
[    0.000000] kernel direct mapping tables up to 3080000000 @ [0x307ff3d000-0x307fffffff]
[    0.000000]     memblock_x86_reserve_range: [0x307ffc0000-0x307fffffff]          PGTABLE
[    0.000000] init_memory_mapping: [0x00003080000000-0x0000407fffffff]
[    0.000000]  3080000000 - 4080000000 page 2M
[    0.000000] kernel direct mapping tables up to 4080000000 @ [0x407fefd000-0x407fffffff]
[    0.000000]     memblock_x86_reserve_range: [0x407ffc0000-0x407fffffff]          PGTABLE
[    0.000000] init_memory_mapping: [0x00004080000000-0x0000507fffffff]
[    0.000000]  4080000000 - 5080000000 page 2M
[    0.000000] kernel direct mapping tables up to 5080000000 @ [0x507febd000-0x507fffffff]
[    0.000000]     memblock_x86_reserve_range: [0x507ffc0000-0x507fffffff]          PGTABLE
[    0.000000] init_memory_mapping: [0x00005080000000-0x0000607fffffff]
[    0.000000]  5080000000 - 6080000000 page 2M
[    0.000000] kernel direct mapping tables up to 6080000000 @ [0x607fe7d000-0x607fffffff]
[    0.000000]     memblock_x86_reserve_range: [0x607ffc0000-0x607fffffff]          PGTABLE
[    0.000000] init_memory_mapping: [0x00006080000000-0x0000707fffffff]
[    0.000000]  6080000000 - 7080000000 page 2M
[    0.000000] kernel direct mapping tables up to 7080000000 @ [0x707fe3d000-0x707fffffff]
[    0.000000]     memblock_x86_reserve_range: [0x707ffc0000-0x707fffffff]          PGTABLE
[    0.000000] init_memory_mapping: [0x00007080000000-0x0000807fffffff]
[    0.000000]  7080000000 - 8080000000 page 2M
[    0.000000] kernel direct mapping tables up to 8080000000 @ [0x807fdfc000-0x807fffffff]
[    0.000000]     memblock_x86_reserve_range: [0x807ffbf000-0x807fffffff]          PGTABLE
[    0.000000] Initmem setup node 0 [0000000000000000-000000107fffffff]
[    0.000000]   NODE_DATA [0x0000107ffbd000-0x0000107ffc1fff]
[    0.000000] Initmem setup node 1 [0000001080000000-000000207fffffff]
[    0.000000]   NODE_DATA [0x0000207ffbb000-0x0000207ffbffff]
[    0.000000] Initmem setup node 2 [0000002080000000-000000307fffffff]
[    0.000000]   NODE_DATA [0x0000307ffbb000-0x0000307ffbffff]
[    0.000000] Initmem setup node 3 [0000003080000000-000000407fffffff]
[    0.000000]   NODE_DATA [0x0000407ffbb000-0x0000407ffbffff]
[    0.000000] Initmem setup node 4 [0000004080000000-000000507fffffff]
[    0.000000]   NODE_DATA [0x0000507ffbb000-0x0000507ffbffff]
[    0.000000] Initmem setup node 5 [0000005080000000-000000607fffffff]
[    0.000000]   NODE_DATA [0x0000607ffbb000-0x0000607ffbffff]
[    0.000000] Initmem setup node 6 [0000006080000000-000000707fffffff]
[    0.000000]   NODE_DATA [0x0000707ffbb000-0x0000707ffbffff]
[    0.000000] Initmem setup node 7 [0000007080000000-000000807fffffff]
[    0.000000]   NODE_DATA [0x0000807ffba000-0x0000807ffbefff]
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
LKML-Reference: <4D1933D1.9020609@kernel.org>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

While dubug kdump, found current kernel will have problem with crashkernel=512M.

It turns out that initial mapping is to 512M, and later initial mapping to 4G
(acutally is 2040M in my platform), will put page table near 512M.
then initial mapping to 128g will be near 2g.

before this patch:
[    0.000000] initial memory mapped : 0 - 20000000
[    0.000000] init_memory_mapping: [0x00000000000000-0x0000007f74ffff]
[    0.000000]  0000000000 - 007f600000 page 2M
[    0.000000]  007f600000 - 007f750000 page 4k
[    0.000000] kernel direct mapping tables up to 7f750000 @ [0x1fffc000-0x1fffffff]
[    0.000000]     memblock_x86_reserve_range: [0x1fffc000-0x1fffdfff]          PGTABLE
[    0.000000] init_memory_mapping: [0x00000100000000-0x0000207fffffff]
[    0.000000]  0100000000 - 2080000000 page 2M
[    0.000000] kernel direct mapping tables up to 2080000000 @ [0x7bc01000-0x7bc83fff]
[    0.000000]     memblock_x86_reserve_range: [0x7bc01000-0x7bc7efff]          PGTABLE
[    0.000000] RAMDISK: 7bc84000 - 7f745000
[    0.000000] crashkernel reservation failed - No suitable area found.

after patch:
[    0.000000] initial memory mapped : 0 - 20000000
[    0.000000] init_memory_mapping: [0x00000000000000-0x0000007f74ffff]
[    0.000000]  0000000000 - 007f600000 page 2M
[    0.000000]  007f600000 - 007f750000 page 4k
[    0.000000] kernel direct mapping tables up to 7f750000 @ [0x7f74c000-0x7f74ffff]
[    0.000000]     memblock_x86_reserve_range: [0x7f74c000-0x7f74dfff]          PGTABLE
[    0.000000] init_memory_mapping: [0x00000100000000-0x0000207fffffff]
[    0.000000]  0100000000 - 2080000000 page 2M
[    0.000000] kernel direct mapping tables up to 2080000000 @ [0x207ff7d000-0x207fffffff]
[    0.000000]     memblock_x86_reserve_range: [0x207ff7d000-0x207fffafff]          PGTABLE
[    0.000000] RAMDISK: 7bc84000 - 7f745000
[    0.000000]     memblock_x86_reserve_range: [0x17000000-0x36ffffff]     CRASH KERNEL
[    0.000000] Reserving 512MB of memory at 368MB for crashkernel (System RAM: 133120MB)

It means with the patch, page table for [0, 2g) will need 2g, instead of under 512M,
page table for [4g, 128g) will be near 128g, instead of under 2g.

That would good, if we have lots of memory above 4g, like 1024g, or 2048g or 16T, will not put
related page table under 2g. that would be have chance to fill the under 2g if 1G or 2M page is
not used.

the code change will use add map_low_page() and update unmap_low_page() for 64bit, and use them
to get access the corresponding high memory for page table setting.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
LKML-Reference: <4D0C0734.7060900@kernel.org>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

This patch expands functionality of CONFIG_DEBUG_RODATA to set main
(static) kernel data area as NX.

The following steps are taken to achieve this:

 1. Linker script is adjusted so .text always starts and ends on a page bound
 2. Linker script is adjusted so .rodata always start and end on a page boundary
 3. NX is set for all pages from _etext through _end in mark_rodata_ro.
 4. free_init_pages() sets released memory NX in arch/x86/mm/init.c
 5. bios rom is set to x when pcibios is used.

The results of patch application may be observed in the diff of kernel page
table dumps:

pcibios:

 -- data_nx_pt_before.txt       2009-10-13 07:48:59.000000000 -0400
 ++ data_nx_pt_after.txt        2009-10-13 07:26:46.000000000 -0400
  0x00000000-0xc0000000           3G                           pmd
  ---[ Kernel Mapping ]---
 -0xc0000000-0xc0100000           1M     RW             GLB x  pte
 +0xc0000000-0xc00a0000         640K     RW             GLB NX pte
 +0xc00a0000-0xc0100000         384K     RW             GLB x  pte
 -0xc0100000-0xc03d7000        2908K     ro             GLB x  pte
 +0xc0100000-0xc0318000        2144K     ro             GLB x  pte
 +0xc0318000-0xc03d7000         764K     ro             GLB NX pte
 -0xc03d7000-0xc0600000        2212K     RW             GLB x  pte
 +0xc03d7000-0xc0600000        2212K     RW             GLB NX pte
  0xc0600000-0xf7a00000         884M     RW         PSE GLB NX pmd
  0xf7a00000-0xf7bfe000        2040K     RW             GLB NX pte
  0xf7bfe000-0xf7c00000           8K                           pte

No pcibios:

 -- data_nx_pt_before.txt       2009-10-13 07:48:59.000000000 -0400
 ++ data_nx_pt_after.txt        2009-10-13 07:26:46.000000000 -0400
  0x00000000-0xc0000000           3G                           pmd
  ---[ Kernel Mapping ]---
 -0xc0000000-0xc0100000           1M     RW             GLB x  pte
 +0xc0000000-0xc0100000           1M     RW             GLB NX pte
 -0xc0100000-0xc03d7000        2908K     ro             GLB x  pte
 +0xc0100000-0xc0318000        2144K     ro             GLB x  pte
 +0xc0318000-0xc03d7000         764K     ro             GLB NX pte
 -0xc03d7000-0xc0600000        2212K     RW             GLB x  pte
 +0xc03d7000-0xc0600000        2212K     RW             GLB NX pte
  0xc0600000-0xf7a00000         884M     RW         PSE GLB NX pmd
  0xf7a00000-0xf7bfe000        2040K     RW             GLB NX pte
  0xf7bfe000-0xf7c00000           8K                           pte

The patch has been originally developed for Linux 2.6.34-rc2 x86 by
Siarhei Liakh <sliakh.lkml@gmail.com> and Xuxian Jiang <jiang@cs.ncsu.edu>.

 -v1:  initial patch for 2.6.30
 -v2:  patch for 2.6.31-rc7
 -v3:  moved all code into arch/x86, adjusted credits
 -v4:  fixed ifdef, removed credits from CREDITS
 -v5:  fixed an address calculation bug in mark_nxdata_nx()
 -v6:  added acked-by and PT dump diff to commit log
 -v7:  minor adjustments for -tip
 -v8:  rework with the merge of "Set first MB as RW+NX"
Signed-off-by: NSiarhei Liakh <sliakh.lkml@gmail.com>
Signed-off-by: NXuxian Jiang <jiang@cs.ncsu.edu>
Signed-off-by: NMatthieu CASTET <castet.matthieu@free.fr>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: James Morris <jmorris@namei.org>
Cc: Andi Kleen <ak@muc.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Dave Jones <davej@redhat.com>
Cc: Kees Cook <kees.cook@canonical.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <4CE2F82E.60601@free.fr>
[ minor cleanliness edits ]
Signed-off-by: NIngo Molnar <mingo@elte.hu>

1.include linux/memblock.h directly. so later could reduce e820.h reference.
2 this patch is done by sed scripts mainly

-v2: use MEMBLOCK_ERROR instead of -1ULL or -1UL
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: NTejun Heo <tj@kernel.org>
Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

When CONFIG_NO_BOOTMEM=y, it could use memory more effiently, or
in a more compact fashion.

Example:

 Allocated new RAMDISK: 00ec2000 - 0248ce57
 Move RAMDISK from 000000002ea04000 - 000000002ffcee56 to 00ec2000 - 0248ce56

The new RAMDISK's end is not page aligned.
Last page could be shared with other users.

When free_init_pages are called for initrd or .init, the page
could be freed and we could corrupt other data.

code segment in free_init_pages():

 |        for (; addr < end; addr += PAGE_SIZE) {
 |                ClearPageReserved(virt_to_page(addr));
 |                init_page_count(virt_to_page(addr));
 |                memset((void *)(addr & ~(PAGE_SIZE-1)),
 |                        POISON_FREE_INITMEM, PAGE_SIZE);
 |                free_page(addr);
 |                totalram_pages++;
 |        }

last half page could be used as one whole free page.

So page align the boundaries.

-v2: make the original initramdisk to be aligned, according to
     Johannes, otherwise we have the chance to lose one page.
     we still need to keep initrd_end not aligned, otherwise it could
     confuse decompressor.
-v3: change to WARN_ON instead, suggested by Johannes.
-v4: use PAGE_ALIGN, suggested by Johannes.
     We may fix that macro name later to PAGE_ALIGN_UP, and PAGE_ALIGN_DOWN
     Add comments about assuming ramdisk start is aligned
     in relocate_initrd(), change to re get ramdisk_image instead of save it
     to make diff smaller. Add warning for wrong range, suggested by Johannes.
-v6: remove one WARN()
     We need to align beginning in free_init_pages()
     do not copy more than ramdisk_size, noticed by Johannes
Reported-by: NStanislaw Gruszka <sgruszka@redhat.com>
Tested-by: NStanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: David Miller <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <1269830604-26214-3-git-send-email-yinghai@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch changes the 32-bit version of kernel_physical_mapping_init() to
return the last mapped address like the 64-bit one so that we can unify the
call-site in init_memory_mapping().

Cc: Yinghai Lu <yinghai@kernel.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
LKML-Reference: <alpine.DEB.2.00.1002241703570.1180@melkki.cs.helsinki.fi>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

It is possible for x86_64 systems to lack the NX bit either due to the
hardware lacking support or the BIOS having turned off the CPU capability,
so NX status should be reported.  Additionally, anyone booting NX-capable
CPUs in 32bit mode without PAE will lack NX functionality, so this change
provides feedback for that case as well.
Signed-off-by: NKees Cook <kees.cook@canonical.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
LKML-Reference: <1258154897-6770-6-git-send-email-hpa@zytor.com>

The 32- and 64-bit code used very different mechanisms for enabling
NX, but even the 32-bit code was enabling NX in head_32.S if it is
available.  Furthermore, we had a bewildering collection of tests for
the available of NX.

This patch:

a) merges the 32-bit set_nx() and the 64-bit check_efer() function
   into a single x86_configure_nx() function.  EFER control is left
   to the head code.

b) eliminates the nx_enabled variable entirely.  Things that need to
   test for NX enablement can verify __supported_pte_mask directly,
   and cpu_has_nx gives the supported status of NX.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Chris Wright <chrisw@sous-sol.org>
LKML-Reference: <1258154897-6770-5-git-send-email-hpa@zytor.com>
Acked-by: NKees Cook <kees.cook@canonical.com>

Move the NX setup into a separate file so that it can be compiled
without stack-protection while leaving the rest of the mm/init code
protected.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

This sparse warning:

  arch/x86/mm/init.c:83:16: warning: symbol 'check_efer' was not declared. Should it be static?

triggers because check_efer() is not decalared before using it.
asm/proto.h includes the declaration of check_efer(), so
including asm/proto.h to fix that - this also addresses the
sparse warning.
Signed-off-by: NJaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <1246458263.6940.22.camel@hpdv5.satnam>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The init_gbpages() function is conditionally called from
init_memory_mapping() function. There are two call-sites where
this 'after_bootmem' condition can be true: setup_arch() and
mem_init() via pci_iommu_alloc().

Therefore, it's safe to move the call to init_gbpages() to
setup_arch() as it's always called before mem_init().

This removes an after_bootmem use - paving the way to remove
all uses of that state variable.
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Acked-by: NYinghai Lu <yinghai@kernel.org>
LKML-Reference: <Pine.LNX.4.64.0906221731210.19474@melkki.cs.Helsinki.FI>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The hooks that we modify are:
- Page fault handler (to handle kmemcheck faults)
- Debug exception handler (to hide pages after single-stepping
  the instruction that caused the page fault)

Also redefine memset() to use the optimized version if kmemcheck is
enabled.

(Thanks to Pekka Enberg for minimizing the impact on the page fault
handler.)

As kmemcheck doesn't handle MMX/SSE instructions (yet), we also disable
the optimized xor code, and rely instead on the generic C implementation
in order to avoid false-positive warnings.
Signed-off-by: NVegard Nossum <vegardno@ifi.uio.no>

[whitespace fixlet]
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

[rebased for mainline inclusion]
Signed-off-by: NVegard Nossum <vegardno@ifi.uio.no>

Do this so we can check the range that is mapped before
init_memory_mapping().

To be able to print out meaningful info, we first have to fix
64-bit to have max_pfn_mapped assigned before that call. This
also unifies the code-path a bit.

[ Impact: print more debug info, cleanup ]
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
LKML-Reference: <49BF0978.40605@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

With the introduction of the .brk section, special care must be taken
that no unused page table entries remain if _brk_end and _end are
separated by a 2M page boundary. cleanup_highmap() runs very early and
hence cannot take care of that, hence potential entries needing to be
removed past _brk_end must be cleared once the brk allocator has done
its job.

[ Impact: avoids undesirable TLB aliases ]
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

[ Impact: cleanup ]
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
LKML-Reference: <1240923650.1982.22.camel@penberg-laptop>
Signed-off-by: NIngo Molnar <mingo@elte.hu>