Reenable kprobes and alternative patching when the kernel text is write
protected by DEBUG_RODATA

Add a general utility function to change write protected text.  The new
function remaps the code using vmap to write it and takes care of CPU
synchronization.  It also does CLFLUSH to make icache recovery faster.

There are some limitations on when the function can be used, see the
comment.

This is a newer version that also changes the paravirt_ops code.
text_poke also supports multi byte patching now.

Contains bug fixes from Zach Amsden and suggestions from Mathieu
Desnoyers.

Cc: Jan Beulich <jbeulich@novell.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Mathieu Desnoyers <compudj@krystal.dyndns.org>
Cc: Zach Amsden <zach@vmware.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch uses the read and write functions provided at system.h
for control registers instead of writting raw assembly over and
over again in .c files. Functions to manipulate cr2 and cr8 were
provided, as they were lacking.

Also, removed some extra space after closing brackets
Signed-off-by: NGlauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch makes the i386 behave the same way that x86_64 does when a
segfault happens.  A line gets printed to the kernel log so that tools
that need to check for failures can behave more uniformly between
debug.show_unhandled_signals sysctl variable to 0 (or by doing echo 0 >
/proc/sys/debug/exception-trace)

Also, all of the lines being printed are now using printk_ratelimit() to
deny the ability of DoS from a local user with a program like the
following:

main()
{
       while (1)
               if (!fork()) *(int *)0 = 0;
}

This new revision also includes the fix that Andrew did which got rid of
new sysctl that was added to the system in earlier versions of this.
Also, 'show-unhandled-signals' sysctl has been renamed back to the old
'exception-trace' to avoid breakage of people's scripts.

AK: Enabling by default for i386 will be likely controversal, but let's see what happens
AK: Really folks, before complaining just fix your segfaults
AK: I bet this will find a lot of silent issues
Signed-off-by: NMasoud Sharbiani <masouds@google.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
[ Personally, I've found the complaints useful on x86-64, so I'm all for
  this. That said, I wonder if we could do it more prettily..   -Linus ]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This implements new vDSO for x86-64.  The concept is similar
to the existing vDSOs on i386 and PPC.  x86-64 has had static
vsyscalls before,  but these are not flexible enough anymore.

A vDSO is a ELF shared library supplied by the kernel that is mapped into
user address space.  The vDSO mapping is randomized for each process
for security reasons.

Doing this was needed for clock_gettime, because clock_gettime
always needs a syscall fallback and having one at a fixed
address would have made buffer overflow exploits too easy to write.

The vdso can be disabled with vdso=0

It currently includes a new gettimeofday implemention and optimized
clock_gettime(). The gettimeofday implementation is slightly faster
than the one in the old vsyscall.  clock_gettime is significantly faster
than the syscall for CLOCK_MONOTONIC and CLOCK_REALTIME.

The new calls are generally faster than the old vsyscall.

Advantages over the old x86-64 vsyscalls:
- Extensible
- Randomized
- Cleaner
- Easier to virtualize (the old static address range previously causes
overhead e.g. for Xen because it has to create special page tables for it)

Weak points:
- glibc support still to be written

The VM interface is partly based on Ingo Molnar's i386 version.

Includes compile fix from Joachim Deguara
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Do not mark the kernel text read only if KPROBES is in the kernel;
kprobes needs to hot-patch the kernel text to insert it's
instrumentation.

In this case, only mark the .rodata segment as read only.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Tested-by: NS. P. Prasanna <prasanna@in.ibm.com>
Cc: Andi Kleen <ak@suse.de>
Cc: William Cohen <wcohen@redhat.com>
Cc: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We aren't sampling for holes in memory.  Thus we encounter a section hole
with empty section map pointer for SPARSEMEM and OOPs for show_mem.  This
issue has been seen in 2.6.21, current git and current mm.  The patch below
is for mainline and mm.  It was boot tested for SPARSEMEM, current VMEMMAP
of Andy's in mm ml and DISCONTIGMEM.  A slightly different patch will be
posted to stable for 2.6.21.

Previous to commit f0a5a58a memory_present
was called for node_start_pfn to node_end_pfn.  This would cover the
hole(s) with reserved pages and valid sections.  Most SPARSEMEM supported
arches do a pfn_valid check in show_mem before computing the page structure
address.

This issue was brought to my attention on IRC by Arnaldo Carvalho de Melo.
Thanks to Arnaldo for testing.
Signed-off-by: NBob Picco <bob.picco@hp.com>
Cc: Chuck Ebbert <cebbert@redhat.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: NAndy Whitcroft <apw@shadowen.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

On systems with huge amount of physical memory, VFS cache and memory memmap
may eat all available system memory under 4G, then the system may fail to
allocate swiotlb bounce buffer.

There was a fix for this issue in arch/x86_64/mm/numa.c, but that fix dose
not cover sparsemem model.

This patch add fix to sparsemem model by first try to allocate memmap above
4G.
Signed-off-by: NZou Nan hai <nanhai.zou@intel.com>
Acked-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is to fix many section mismatches of code related to memory hotplug.
I checked compile with memory hotplug on/off on ia64 and x86-64 box.
Signed-off-by: NYasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This was broken.  It adds complexity, for no good reason.  Rather than
separate __pa() and __pa_symbol(), we should deprecate __pa_symbol(),
and preferably __pa() too - and just use "virt_to_phys()" instead, which
is more readable and has nicer semantics.

However, right now, just undo the separation, and make __pa_symbol() be
the exact same as __pa().  That fixes the bugs this patch introduced,
and we can do the fairly obvious cleanups later.

Do the new __phys_addr() function (which is now the actual workhorse for
the unified __pa()/__pa_symbol()) as a real external function, that way
all the potential issues with compile/link-time optimizations of
constant symbol addresses go away, and we can also, if we choose to, add
more sanity-checking of the argument.

Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch touches the NMI watchdog every MAX_ORDER_NR_PAGES
to inhibit the machine from triggering an NMI while the CPUs
are locked. This situation is happening on boxes with more
than 64CPUs and 128GB of RAM when Alt-SysRq-m is performed.

It has been succesfully tested for regression on uni, 2, 4, 8
32, and 64 CPU boxes with various memory configuration.
Signed-off-by: NAndi Kleen <ak@suse.de>

On x86-64, kernel memory freed after init can be entirely unmapped instead
of just getting 'poisoned' by overwriting with a debug pattern.

On i386 and x86-64 (under CONFIG_DEBUG_RODATA), kernel text and bug table
can also be write-protected.

Compared to the first version, this one prevents re-creating deleted
mappings in the kernel image range on x86-64, if those got removed
previously. This, together with the original changes, prevents temporarily
having inconsistent mappings when cacheability attributes are being
changed on such pages (e.g. from AGP code). While on i386 such duplicate
mappings don't exist, the same change is done there, too, both for
consistency and because checking pte_present() before using various other
pte_XXX functions is a requirement anyway. At once, i386 code gets
adjusted to use pte_huge() instead of open coding this.

AK: split out cpa() changes
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Currently __pa_symbol is for use with symbols in the kernel address
map and __pa is for use with pointers into the physical memory map.
But the code is implemented so you can usually interchange the two.

__pa which is much more common can be implemented much more cheaply
if it is it doesn't have to worry about any other kernel address
spaces.  This is especially true with a relocatable kernel as
__pa_symbol needs to peform an extra variable read to resolve
the address.

There is a third macro that is added for the vsyscall data
__pa_vsymbol for finding the physical addesses of vsyscall pages.

Most of this patch is simply sorting through the references to
__pa or __pa_symbol and using the proper one.  A little of
it is continuing to use a physical address when we have it
instead of recalculating it several times.

swapper_pgd is now NULL.  leave_mm now uses init_mm.pgd
and init_mm.pgd is initialized at boot (instead of compile time)
to the physmem virtual mapping of init_level4_pgd.  The
physical address changed.

Except for the for EMPTY_ZERO page all of the remaining references
to __pa_symbol appear to be during kernel initialization.  So this
should reduce the cost of __pa in the common case, even on a relocated
kernel.

As this is technically a semantic change we need to be on the lookout
for anything I missed.  But it works for me (tm).
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

With the rewrite of the SMP trampoline and the early page
allocator there is nothing that needs identity mapped pages,
once we start executing C code.

So add zap_identity_mappings into head64.c and remove
zap_low_mappings() from much later in the code.  The functions
 are subtly different thus the name change.

This also kills boot_level4_pgt which was from an earlier
attempt to move the identity mappings as early as possible,
and is now no longer needed.  Essentially I have replaced
boot_level4_pgt with trampoline_level4_pgt in trampoline.S
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Early in the boot process we need the ability to set
up temporary mappings, before our normal mechanisms are
initialized.  Currently this is used to map pages that
are part of the page tables we are building and pages
during the dmi scan.

The core problem is that we are using the user portion of
the page tables to implement this.  Which means that while
this mechanism is active we cannot catch NULL pointer dereferences
and we deviate from the normal ways of handling things.

In this patch I modify early_ioremap to map pages into
the kernel portion of address space, roughly where
we will later put modules, and I make the discovery of
which addresses we can use dynamic which removes all
kinds of static limits and remove the dependencies
on implementation details between different parts of the code.

Now alloc_low_page() and unmap_low_page() use
early_iomap() and early_iounmap() to allocate/map and
unmap a page.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

The dma_ops structure can be const since it never changes
after boot.
Signed-off-by: NStephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: NAndi Kleen <ak@suse.de>

The semantic effect of insert_at_head is that it would allow new registered
sysctl entries to override existing sysctl entries of the same name.  Which is
pain for caching and the proc interface never implemented.

I have done an audit and discovered that none of the current users of
register_sysctl care as (excpet for directories) they do not register
duplicate sysctl entries.

So this patch simply removes the support for overriding existing entries in
the sys_sysctl interface since no one uses it or cares and it makes future
enhancments harder.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NRalf Baechle <ralf@linux-mips.org>
Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Corey Minyard <minyard@acm.org>
Cc: Neil Brown <neilb@suse.de>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Jan Kara <jack@ucw.cz>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: David Chinner <dgc@sgi.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The only sysctl x86_64 provides are not provided elsewhere, so insert_at_head
is unnecessary.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The final line of /proc/<pid>/maps on x86_64 for native 64-bit
tasks shows an incorrect ending address and incorrect permissions.  There
is only a single page mapped in this vsyscall region, and it is accessible
for both read and execute.

The patch below fixes this.  (Since 32-bit-compat tasks have a real vma
with correct perms/range, no change is necessary for that scenario.)

Before the patch, a "cat /proc/self/maps | tail -1" shows this:

        ffffffffff600000-ffffffffffe00000 ---p 00000000 [...]

After the patch, this is the output:

        ffffffffff600000-ffffffffff601000 r-xp 00000000 [...]
Signed-off-by: NErnie Petrides <petrides@redhat.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

This is to fix compile error of x86-64 memory hotplug without any NUMA
option.

  CC      arch/x86_64/mm/init.o
arch/x86_64/mm/init.c:501: error: redefinition of 'memory_add_physaddr_to_nid'
include/linux/memory_hotplug.h:71: error: previous definition of 'memory_add_phys
addr_to_nid' was here
arch/x86_64/mm/init.c:509: error: redefinition of 'memory_add_physaddr_to_nid'
arch/x86_64/mm/init.c:501: error: previous definition of 'memory_add_physaddr_to_
nid' was here

I confirmed compile completion with !NUMA, (NUMA & !ACPI_NUMA),
or (NUMA & ACPI_NUMA).
Signed-off-by: NYasunori Goto <y-goto@jp.fujitsu.com>
Acked-by: NAndi Kleen <ak@suse.de>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This can happen on kexec kernels with some configurations, in particularly
on Unisys ES7000 systems.

Analysis by Amul Shah

Cc: Amul Shah <amul.shah@unisys.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Arch-independent zone-sizing is using indices instead of symbolic names to
offset within an array related to zones (max_zone_pfns).  The unintended
impact is that ZONE_DMA and ZONE_NORMAL is initialised on powerpc instead
of ZONE_DMA and ZONE_HIGHMEM when CONFIG_HIGHMEM is set.  As a result, the
the machine fails to boot but will boot with CONFIG_HIGHMEM turned off.

The following patch properly initialises the max_zone_pfns[] array and uses
symbolic names instead of indices in each architecture using
arch-independent zone-sizing.  Two users have successfully booted their
powerpcs with it (one an ibook G4).  It has also been boot tested on x86,
x86_64, ppc64 and ia64.  Please merge for 2.6.19-rc2.

Credit to Benjamin Herrenschmidt for identifying the bug and rolling the
first fix.  Additional credit to Johannes Berg and Andreas Schwab for
reporting the problem and testing on powerpc.
Signed-off-by: NMel Gorman <mel@csn.ul.ie>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The api for hot-add memory already has a construct for finding nodes based on
an address, memory_add_physaddr_to_nid.  This patch allows the fucntion to do
something besides return 0.  It uses the nodes_add infomation to lookup to
node info for a hot add event.
Signed-off-by: NKeith Mannthey <kmannth@us.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

In cases where the acpi memory-add event does not containe the pxm (node)
infomation allow the driver to look up node info based on the address.  The
acpi_get_node call returns -1 if it can't decode the pxm info, this causes
add_memory to panic.  acpi_get_node would have to decode the resource from the
handle (a lenghty proposition).  This seems to be the cleanist point to
interject the hook.

[kamezawa.hiroyu@jp.fujitsu.com: build fixes]
[y-goto@jp.fujitsu.com: build fixes]
Signed-off-by: NKeith Mannthey <kmannth@us.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NYasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The api for hot-add memory already has a construct for finding nodes based on
an address, memory_add_physaddr_to_nid.  This patch allows the fucntion to do
something besides return 0.  It uses the nodes_add infomation to lookup to
node info for a hot add event.
Signed-off-by: NKeith Mannthey <kmannth@us.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The x86_64 code accounted for memmap and some portions of the the DMA zone as
holes.  This was because those areas would never be reclaimed and accounting
for them as memory affects min watermarks.  This patch will account for the
memmap as a memory hole.  Architectures may optionally use set_dma_reserve()
if they wish to account for a portion of memory in ZONE_DMA as a hole.
Signed-off-by: NMel Gorman <mel@csn.ul.ie>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Andi Kleen <ak@muc.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "Keith Mannthey" <kmannth@gmail.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Size zones and holes in an architecture independent manner for x86_64.
Signed-off-by: NMel Gorman <mel@csn.ul.ie>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Andi Kleen <ak@muc.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "Keith Mannthey" <kmannth@gmail.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

I keep seeing zones on various platforms that are never used and wonder why we
compile support for them into the kernel.  Counters show up for HIGHMEM and
DMA32 that are alway zero.

This patch allows the removal of ZONE_DMA32 for non x86_64 architectures and
it will get rid of ZONE_HIGHMEM for arches not using highmem (like 64 bit
architectures).  If an arch does not define CONFIG_HIGHMEM then ZONE_HIGHMEM
will not be defined.  Similarly if an arch does not define CONFIG_ZONE_DMA32
then ZONE_DMA32 will not be defined.

No current architecture uses all the 4 zones (DMA,DMA32,NORMAL,HIGH) that we
have now.  The patchset will reduce the number of zones for all platforms.

On many platforms that do not have DMA32 or HIGHMEM this will reduce the
number of zones by 50%.  F.e.  ia64 only uses DMA and NORMAL.

Large amounts of memory can be saved for larger systemss that may have a few
hundred NUMA nodes.

With ZONE_DMA32 and ZONE_HIGHMEM support optional MAX_NR_ZONES will be 2 for
many non i386 platforms and even for i386 without CONFIG_HIGHMEM set.

Tested on ia64, x86_64 and on i386 with and without highmem.

The patchset consists of 11 patches that are following this message.

One could go even further than this patchset and also make ZONE_DMA optional
because some platforms do not need a separate DMA zone and can do DMA to all
of memory.  This could reduce MAX_NR_ZONES to 1.  Such a patchset will
hopefully follow soon.

This patch:

Fix strange uses of MAX_NR_ZONES

Sometimes we use MAX_NR_ZONES - x to refer to a zone.  Make that explicit.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

It is correct for its only caller right now, but not for possible
future others.
Signed-off-by: NAndi Kleen <ak@suse.de>

Fix for the x86_64 kernel mapping code.  Without this patch the update path
only inits one pmd_page worth of memory and tramples any entries on it.  now
the calling convention to phys_pmd_init and phys_init is to always pass a
[pmd/pud] page not an offset within a page.

Signed-off-by: Keith Mannthey<kmannth@us.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>

While an earlier patch already did a small step into that direction,
this patch moves initialization of all memory end variables to as
early as possible, so that dependent code doesn't need to check
whether these variables have already been set.

Also, remove a misleading (perhaps just outdated) comment, and make
static a variable only used in a single file.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Add __start_rodata and __end_rodata to sections.h to avoid extern
declarations.  Needed by s390 code (see following patch).

[akpm@osdl.org: update architectures]
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Cc: Andi Kleen <ak@muc.de>
Acked-by: NKyle McMartin <kyle@mcmartin.ca>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

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

Localize poison values into one header file for better documentation and
easier/quicker debugging and so that the same values won't be used for
multiple purposes.

Use these constants in core arch., mm, driver, and fs code.
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Acked-by: NMatt Mackall <mpm@selenic.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Change the name of old add_memory() to arch_add_memory.  And use node id to
get pgdat for the node at NODE_DATA().

Note: Powerpc's old add_memory() is defined as __devinit. However,
      add_memory() is usually called only after bootup.
      I suppose it may be redundant. But, I'm not well known about powerpc.
      So, I keep it. (But, __meminit is better at least.)
Signed-off-by: NYasunori Goto <y-goto@jp.fujitsu.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: "Brown, Len" <len.brown@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

 - fix an off-by-one error in phys_pmd_init()
 - prevent phys_pmd_init() from removing mappings established earlier
 - fix the direct mapping early printk to in fact show the end of the range
 - remove an apparently orphan comment
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch creates a new interface for IOMMUs by adding a centralized
location for IOMMU allocation (for translation tables/apertures) and
IOMMU initialization.  In creating these, code was moved around for
abstraction, uniformity, and consiceness.

Take note of the move of the iommu_setup bootarg parsing code to
__setup.  This is enabled by moving back the location of the aperture
allocation/detection to mem init (which while ugly, was already the
location of the swiotlb_init).

While a slight departure from the previous patch, I belive this provides
the true intention of the previous versions of the patch which changed
this code.  It also makes the addition of the upcoming calgary code much
cleaner than previous patches.

[AK: Removed one broken change. iommu_setup still has to be called
early]
Signed-off-by: NMuli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: NJon Mason <jdmason@us.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

pud_offset_k() equivalent to pud_offset() now.  Pointed out by Jan Beulich
Similar for __pud_offset_ok, which needs a small change in the callers.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Changes are largely identical to the i386 version:

 * alternative #define are moved to the new alternative.h file.
 * one new elf section with pointers to the lock prefixes which can be
   nop'ed out for non-smp.
 * two new elf sections simliar to the "classic" alternatives to
   replace SMP code with simpler UP code.
 * fixup headers to use alternative.h instead of defining their own
   LOCK / LOCK_PREFIX macros.

The patch reuses the i386 version of the alternatives code to avoid code
duplication.  The code in alternatives.c was shuffled around a bit to
reduce the number of #ifdefs needed.  It also got some tweaks needed for
x86_64 (vsyscall page handling) and new features (noreplacement option
which was x86_64 only up to now).  Debug printk's are changed from
compile-time to runtime.

Loosely based on a early version from Bastian Blank <waldi@debian.org>
Signed-off-by: NGerd Hoffmann <kraxel@suse.de>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>