Fix endcase where the memory at physical address 0 does not really
exist AND one of the sockets on blade 0 has no active cpus.

The memory that _appears_ to be at physical address 0 is actually
memory that located at a different address but has been remapped by
the chipset so that it appears to be at physical address 0.

When determining the UV pnode, the algorithm for determining the pnode
incorrectly used the relocated physical address instead of the actual
(global) address.

[ Impact: boot failure on partitioned systems ]
Signed-off-by: NJack Steiner <steiner@sgi.com>
LKML-Reference: <20090420132530.GA23156@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Fixes guest crash 'lguest: bad read address 0x4800000 len 256'

The new per-cpu allocator ends up handing a non-linear address to
write_gdt_entry.  We do __pa() on it, and hand it to the host, which
kills us.

I've long wanted to make the hypercall "LOAD_GDT_ENTRY" to match the IDT
code, but had no pressing reason until now.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: lguest@ozlabs.org

calculate_numa_remap_pages() is called only by __init initmem_init()
further calculate_numa_remap_pages is calling:
	__init find_e820_area() and __init reserve_early()

So calculate_numa_remap_pages() should be __init calculate_numa_remap_pages().

 WARNING: arch/x86/built-in.o(.text+0x82ea3): Section mismatch in reference from the function calculate_numa_remap_pages() to the function .init.text:find_e820_area()
 The function calculate_numa_remap_pages() references
 the function __init find_e820_area().
 This is often because calculate_numa_remap_pages lacks a __init
 annotation or the annotation of find_e820_area is wrong.

 WARNING: arch/x86/built-in.o(.text+0x82f5f): Section mismatch in reference from the function calculate_numa_remap_pages() to the function .init.text:reserve_early()
 The function calculate_numa_remap_pages() references
 the function __init reserve_early().
 This is often because calculate_numa_remap_pages lacks a __init
 annotation or the annotation of reserve_early is wrong.

[ Impact: save memory, address Section mismatch warning ]
Signed-off-by: NJaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
LKML-Reference: <1239991281.3153.4.camel@ht.satnam>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

It is common to use "make install" in restricted environments which
differ from the one which was actually used to build the kernel.  In
such environments it is highly undesirable to trigger a rebuild of any
part of the system.  Worse, the rebuild may be spurious, triggered by
differences in the environment.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
LKML-Reference: <20090415234642.GA28531@uranus.ravnborg.org>

Fix an endcase in the UV initialization code for the "UV large system mode"
of apicids.  If node zero contains no cpus, cpus on another node will be the
boot cpu.  The percpu data that contains the extra apicid bits was not
being initialized early enough.

[ Impact: fix potential boot crash on cpu-less UV nodes ]
Signed-off-by: NJack Steiner <steiner@sgi.com>
LKML-Reference: <20090417142447.GA23759@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Add support for nodes that have cpus but no memory.
The current code was failing to add these nodes
to the nodes_present_map.

v2: Fixes case caught by David Rientjes - missed support
    for the x2apic SRAT table.

[ Impact: fix potential boot crash on memory-less UV nodes. ]
Reported-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NJack Steiner <steiner@sgi.com>
LKML-Reference: <20090417142242.GA23743@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Jeff Garzik reported this WARN_ON() noise:

> Kernel: 2.6.30-rc1-00306-g8371f87c
> Hardware: ICH10 x86-64
>
> This is a regression from 2.6.29.  Microcode spews the following WARNING
> multiple times during boot:
>
> ------------[ cut here ]------------
> WARNING: at fs/sysfs/group.c:138 sysfs_remove_group+0xeb/0xf0()
> Hardware name:         sysfs group ffffffffa0209700 not found for
>  kobject 'cpu0'

Keep sysfs files around for cpus even when we failed to locate
microcode for them at the moment of module loading. The appropriate
microcode firmware can become available later on.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This change resolves the problem of too many single page entries
in pat_memtype_list and "freeing invalid memtype" errors with i915,
reported here:

  http://marc.info/?l=linux-kernel&m=123845244713183&w=2

Remove page level granularity track and untrack of vm_insert_pfn.
memtype tracking at page granularity does not scale and cleaner
approach would be for the driver to request a type for a bigger
IO address range or PCI io memory range for that device, either at
mmap time or driver init time and just use that type during
vm_insert_pfn.

This patch just removes the track/untrack of vm_insert_pfn. That
means we will be in same state as 2.6.28, with respect to these APIs.

Newer APIs for the drivers to request a memtype for a bigger region
is coming soon.

[ Impact: fix Xorg startup warnings and hangs ]
Reported-by: NArkadiusz Miskiewicz <a.miskiewicz@gmail.com>
Tested-by: NArkadiusz Miskiewicz <a.miskiewicz@gmail.com>
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
LKML-Reference: <20090408223716.GC3493@linux-os.sc.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch correctly sets BAU memory mapped registers to point
to the sending activation descriptor table and target payload table.

The "Broadcast Assist Unit" is used for TLB shootdown in UV.

The memory mapped registers that point to sending and receiving
memory structures contain node numbers.

In one case the __pa() function did not provide the node id of
memory on blade zero in configurations where that id is nonzero.
In another case, it was assumed that memory was allocated on
the local node.  That assumption is not true in a configuration
in which the node has no memory.

Tested on the UV hardware simulator.

[ Impact: fix possible runtime crash due to incorrect TLB logic ]
Signed-off-by: NCliff Wickman <cpw@sgi.com>
LKML-Reference: <E1LuR5Z-0007An-B8@eag09.americas.sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Oleg Nesterov found a couple of races in the ptrace-bts code
and fixes are queued up for it but they did not get ready in time
for the merge window. We'll merge them in v2.6.31 - until then
mark the feature as CONFIG_BROKEN. There's no user-space yet
making use of this so it's not a big issue.

Cc: <stable@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

It turns out that 'smp_call_function_many()' doesn't work at all like
'smp_call_function_single()', and my change to Andrew's patch to use it
rather than a loop over all CPU's acpi-cpufreq doesn't work.

My bad.

'smp_call_function_many()' has two "features" (aka "documented bugs"):

 (a) it needs to be called with preemption disabled, because it uses
     smp_processor_id() without guarding the CPU lookup with 'get_cpu()'
     and 'put_cpu()' like the 'single' variant does.

 (b) even if the current CPU is part of the CPU mask, it won't do the
     call on that CPU.

Still, we're better off trying to use 'smp_call_function_many()' than
looping over CPU's, since it at least in theory allows us to use a
broadcast IPI and do it all in parallel.  So let's just work around the
silly semantic bugs in that function.
Reported-and-tested-by: NAli Gholami Rudi <ali@rudi.ir>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Dave Jones <davej@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Revert part of af5c820a ("x86: cpumask:
use work_on_cpu in arch/x86/kernel/microcode_core.c")

That change is causing only one Intel CPU's microcode to be updated e.g.
microcode: CPU3 updated from revision 0x9 to 0x17, date = 2005-04-22
where before it announced that also for CPU0 and CPU1 and CPU2.

We cannot use work_on_cpu() in the CONFIG_MICROCODE_OLD_INTERFACE code,
because Intel's request_microcode_user() involves a copy_from_user() from
/sbin/microcode_ctl, which therefore needs to be on that CPU at the time.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch enables each partition's BAU distribution bit map
to be partition-relative.

The distribution bitmap had been constructed assuming 0 as the base
node number.  That construct would not have allowed a total system of
greater than 256 nodes.
It also corrects an error that occurred when the first blade's nasid
was not zero.  That nasid was stored as the base node.
The base node number gets added by hardware to the node numbers implied
in the distribution bitmap, resulting in invalid target nasids.

Tested on the UV hardware simulator.
Signed-off-by: NCliff Wickman <cpw@sgi.com>
LKML-Reference: <E1Ltl0C-0004Ob-37@eag09.americas.sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

We ended up incorrectly using '&cur' instead of '&readin' in the
work_on_cpu() -> smp_call_function_single() transformation in commit
01599fca ("cpufreq: use
smp_call_function_[single|many]() in acpi-cpufreq.c").

Andrew explains:
 "OK, the acpi tree went and had conflicting changes merged into it after
  I'd written the patch and it appears that I incorrectly reverted part
  of 18b2646f while fixing the resulting
  rejects.

  Switching it to `readin' looks correct."
Acked-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Impact: reduce kernel size a bit, address sparse warning

Addresses the problem pointed out by this sparse warning:

  arch/x86/kernel/pci-swiotlb.c:53:20: warning: symbol 'swiotlb_dma_ops' was not declared. Should it be static?

For x86: swiotlb_dma_ops can be static, because it's not used outside
of pci-swiotlb.c
Signed-off-by: NJaswinder Singh Rajput <jaswinderrajput@gmail.com>
Acked-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
LKML-Reference: <1239558861.3938.2.camel@localhost.localdomain>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Atttempting to rid us of the problematic work_on_cpu().  Just use
smp_call_fuction_single() here.

This repairs a 10% sysbench(oltp)+mysql regression which Mike reported,
due to

  commit 6b44003e
  Author: Andrew Morton <akpm@linux-foundation.org>
  Date:   Thu Apr 9 09:50:37 2009 -0600

      work_on_cpu(): rewrite it to create a kernel thread on demand

It seems that the kernel calls these acpi-cpufreq functions at a quite
high frequency.

Valdis Kletnieks also reports that this causes 70-90 forks per second on
his hardware.

Cc: Valdis.Kletnieks@vt.edu
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Zhao Yakui <yakui.zhao@intel.com>
Acked-by: NDave Jones <davej@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Tested-by: NMike Galbraith <efault@gmx.de>
Cc: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NIngo Molnar <mingo@elte.hu>
[ Made it use smp_call_function_many() instead of looping over cpu's
  with smp_call_function_single()    - Linus ]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Impact: save/restore Intel-AVX state properly between tasks

Intel Advanced Vector Extensions (AVX) introduce 256-bit vector processing
capability. More about AVX at http://software.intel.com/sites/avx

Add OS support for YMM state management using xsave/xrstor infrastructure
to support AVX.
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1239402084.27006.8057.camel@localhost.localdomain>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

pat_disable cannot be __cpuinit anymore because it's called from pat_init
and the callchain looks like this:
pat_disable [cpuinit] <- pat_init <- generic_set_all <-
 ipi_handler <- set_mtrr <- (other non init/cpuinit functions)

WARNING: arch/x86/mm/built-in.o(.text+0x449e): Section mismatch in reference
from the function pat_init() to the function .cpuinit.text:pat_disable()
The function pat_init() references
the function __cpuinit pat_disable().
This is often because pat_init lacks a __cpuinit
annotation or the annotation of pat_disable is wrong.

Non CONFIG_X86_PAT version of pat_disable is static inline, so this version
can be static too (and there are no callers outside of this file).
Signed-off-by: NMarcin Slusarz <marcin.slusarz@gmail.com>
Acked-by: NSam Ravnborg <sam@ravnborg.org>
LKML-Reference: <49DFB055.6070405@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: fix section mismatch

In arch/x86/kernel/mpparse.c, smp_reserve_bootmem() has been called
and also refers to a function which is in .init section. Thus causes
the first warning. And check_irq_src() also requires an __init,
because it refers to an .init section.
Signed-off-by: NRakib Mullick <rakib.mullick@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <b9df5fa10904102004g51265d9axc8d07278bfdb6ba0@mail.gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: fix kprobes crash on 32-bit with RAM above 4G

Use phys_addr_t for receiving a physical address argument
instead of unsigned long. This allows fixmap to handle
pages higher than 4GB on x86-32.
Signed-off-by: NMasami Hiramatsu <mhiramat@redhat.com>
Acked-by: NMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: systemtap-ml <systemtap@sources.redhat.com>
Cc: Gary Hade <garyhade@us.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <49DE3695.6040800@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

/dev/mem mmap code was doing memtype reserve/free for a while now.
Recently we added memtype tracking in remap_pfn_range, and /dev/mem mmap
uses it indirectly. So, we don't need seperate tracking in /dev/mem code
any more. That means another ~100 lines of code removed :-).
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
LKML-Reference: <20090409212709.085210000@intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Fix pat_x_mtrr_type() to use UC_MINUS when the mtrr type return UC. This
is to be  consistent with ioremap() and ioremap_nocache() which uses
UC_MINUS.

Consolidate the code such that reserve_memtype() also uses
pat_x_mtrr_type() when the caller doesn't specify any special attribute
(non WB attribute).
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
LKML-Reference: <20090409212708.939936000@intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

As per SDM, there should not be any aliasing of a WC with any cacheable
type across CPUs. That is if one CPU is changing the identity map
memtype to _WC, no other CPU at the time of this change should not have a
TLB for this page that carries a WB attribute. SDM suggests to make the
page not present. But for that we will have to handle any page faults
that can potentially happen due to these pages being not present.

Other way to deal with this without having any WB mapping is to change
the page first to UC and then to WC. This ensures that we meet the SDM
requirement of no cacheable alais to WC page. This also has same or
lower overhead than marking the page not present and making it present
later.
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <20090409212708.797481000@intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Handle faults and do proper cleanups in set_memory_*() functions. In
some cases, these functions were not doing proper free on failure paths.

With the changes to tracking memtype of RAM pages in struct page instead
of pat list, we do not need the changes in commits c5e147. This patch
reverts that change.
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <20090409212708.653222000@intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

To be free of aliasing due to races, set_memory_* interfaces should
follow ordering of reserving, changing memtype to UC/WC, changing
memtype back to WB followed by free.
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <20090409212708.512280000@intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Change the identity mapping with the requested attribute first, before
we setup the virtual memory mapping with the new requested attribute.

This makes sure that there is no window when identity map'ed attribute
may disagree with ioremap range on the attribute type.

This also avoids doing cpa on the ioremap'ed address twice (first in
ioremap_page_range and then in ioremap_change_attr using vaddr), and
should improve ioremap performance a bit.
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
LKML-Reference: <20090409212708.373330000@intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

While better than get_user_pages(), the usage of gupf(),
especially the return values and the fact that it can
potentially only partially pin the range, warranted some
documentation.
Signed-off-by: NAndy Grover <andy.grover@oracle.com>
Cc: npiggin@suse.de
Cc: akpm@linux-foundation.org
LKML-Reference: <1239320729-3262-1-git-send-email-andy.grover@oracle.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

To simplify level irq migration in the presence of interrupt-remapping,
Suresh used a virtual vector (io-apic pin number) to eliminate io-apic
RTE modification. Level triggered interrupt will appear as an edge to
the local apic cpu but still as level to the IO-APIC. So in addition to
do the local apic EOI, it still needs to do IO-APIC directed EOI to clear
the remote IRR bit in the IO-APIC RTE. Pls refer to Suresh's patch for
more details (commit 0280f7c4).

Now interrupt remapping is decoupled from x2apic, it also needs to do the
directed EOI for apic. Otherwise, apic interrupts won't work correctly.
Signed-off-by: NWeidong Han <weidong.han@intel.com>
Cc: iommu@lists.linux-foundation.org
Cc: Weidong Han <weidong.han@intel.com>
Cc: suresh.b.siddha@intel.com
Cc: dwmw2@infradead.org
Cc: allen.m.kay@intel.com
LKML-Reference: <1239355037-22856-1-git-send-email-weidong.han@intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Use phys_addr_t for receiving a physical address argument instead of
unsigned long.  This allows fixmap to handle pages higher than 4GB on
x86-32.
Signed-off-by: NMasami Hiramatsu <mhiramat@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: NMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It seems by mistake these files got execute permissions so removing it.
Signed-off-by: NJaswinder Singh Rajput <jaswinderrajput@gmail.com>
LKML-Reference: <1239211186.9037.2.camel@ht.satnam>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: fix build warnings and possibe compat misbehavior on IA64

Building a kernel on ia64 might trigger these ugly build warnings:

CC      arch/ia64/ia32/sys_ia32.o
In file included from arch/ia64/ia32/sys_ia32.c:55:
arch/ia64/ia32/ia32priv.h:290:1: warning: "elf_check_arch" redefined
In file included from include/linux/elf.h:7,
                 from include/linux/module.h:14,
                 from include/linux/ftrace.h:8,
                 from include/linux/syscalls.h:68,
                 from arch/ia64/ia32/sys_ia32.c:18:
arch/ia64/include/asm/elf.h:19:1: warning: this is the location of the previous definition
[...]

sys_ia32.c includes linux/syscalls.h which in turn includes linux/ftrace.h
to import the syscalls tracing prototypes.

But including ftrace.h can pull too much things for a low level file,
especially on ia64 where the ia32 private headers conflict with higher
level headers.

Now we isolate the syscall tracing headers in their own lightweight file.
Reported-by: NTony Luck <tony.luck@intel.com>
Tested-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Acked-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jason Baron <jbaron@redhat.com>
Cc: "Frank Ch. Eigler" <fche@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Jiaying Zhang <jiayingz@google.com>
Cc: Michael Rubin <mrubin@google.com>
Cc: Martin Bligh <mbligh@google.com>
Cc: Michael Davidson <md@google.com>
LKML-Reference: <20090408184058.GB6017@nowhere>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

FIX_TEXT_POKE[01] are used to map kernel addresses, so they're mapping
pfns, not mfns.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

Use GATE_INTERRUPT/TRAP rather than 0xe/f.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

Some 64-bit machines don't support the NX flag in ptes.
Check for NX before constructing the kernel pagetables.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

Impact: fixes crashing bug

There's no particular problem with getting an empty cpu mask,
so just shortcut-return if we get one.

Avoids crash reported by Christophe Saout <christophe@saout.de>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

1. make sure early-allocated ptes are pinned, so they can be later
   unpinned
2. don't pin pmd+pud, just make them RO
3. scatter some __inits around
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

Signed-off-by: NAlex Nixon <alex.nixon@citrix.com>

PGE may not be available when running paravirtualized, so test the cpuid
bit before using it.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

Xen leaves XSAVE set in cpuid, but doesn't allow cr4.OSXSAVE
to be set.  This confuses the kernel and it ends up crashing on
an xsetbv instruction.

At boot time, try to set cr4.OSXSAVE, and mask XSAVE out of
cpuid it we can't.  This will produce a spurious error from Xen,
but allows us to support XSAVE if/when Xen does.

This also factors out the cpuid mask decisions to boot time.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

Fix this sparse warnings:
  arch/x86/xen/smp.c:316:52: warning: Using plain integer as NULL pointer
  arch/x86/xen/smp.c:421:60: warning: Using plain integer as NULL pointer
Signed-off-by: NHannes Eder <hannes@hanneseder.net>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>