* 'for-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu: Remove irqsafe_cpu_xxx variants

Fix up conflict in arch/x86/include/asm/percpu.h due to clash with
cebef5beed3d ("x86: Fix and improve percpu_cmpxchg{8,16}b_double()")
which edited the (now removed) irqsafe_cpu_cmpxchg*_double code.

We simply say that regular this_cpu use must be safe regardless of
preemption and interrupt state.  That has no material change for x86
and s390 implementations of this_cpu operations.  However, arches that
do not provide their own implementation for this_cpu operations will
now get code generated that disables interrupts instead of preemption.

-tj: This is part of on-going percpu API cleanup.  For detailed
     discussion of the subject, please refer to the following thread.

     http://thread.gmane.org/gmane.linux.kernel/1222078

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
LKML-Reference: <alpine.DEB.2.00.1112221154380.11787@router.home>

They had several problems/shortcomings:

Only the first memory operand was mentioned in the 2x32bit asm()
operands, and 2x64-bit version had a memory clobber. The first
allowed the compiler to not recognize the need to re-load the
data in case it had it cached in some register, and the second
was overly destructive.

The memory operand in the 2x32-bit asm() was declared to only be
an output.

The types of the local copies of the old and new values were
incorrect (as in other per-CPU ops, the types of the per-CPU
variables accessed should be used here, to make sure the
respective types are compatible).

The __dummy variable was pointless (and needlessly initialized
in the 2x32-bit case), given that local copies of the inputs
already exist.

The 2x64-bit variant forced the address of the first object into
%rsi, even though this is needed only for the call to the
emulation function. The real cmpxchg16b can operate on an
memory.

At once also change the return value type to what it really is -
'bool'.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/4EE86D6502000078000679FE@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Somehow we got into a situation where the __this_cpu_xchg() operations were
not defined in the same way as this_cpu_xchg() and friends. I had some build
failures under 32 bit that were addressed by these fixes.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

* 'for-2.6.40' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu: Unify input section names
  percpu: Avoid extra NOP in percpu_cmpxchg16b_double
  percpu: Cast away printk format warning
  percpu: Always align percpu output section to PAGE_SIZE

Fix up fairly trivial conflict in arch/x86/include/asm/percpu.h as per Tejun

* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (50 commits)
  x86, mm: Allow ZONE_DMA to be configurable
  x86, NUMA: Trim numa meminfo with max_pfn in a separate loop
  x86, NUMA: Rename setup_node_bootmem() to setup_node_data()
  x86, NUMA: Enable emulation on 32bit too
  x86, NUMA: Enable CONFIG_AMD_NUMA on 32bit too
  x86, NUMA: Rename amdtopology_64.c to amdtopology.c
  x86, NUMA: Make numa_init_array() static
  x86, NUMA: Make 32bit use common NUMA init path
  x86, NUMA: Initialize and use remap allocator from setup_node_bootmem()
  x86-32, NUMA: Add @start and @end to init_alloc_remap()
  x86, NUMA: Remove long 64bit assumption from numa.c
  x86, NUMA: Enable build of generic NUMA init code on 32bit
  x86, NUMA: Move NUMA init logic from numa_64.c to numa.c
  x86-32, NUMA: Update numaq to use new NUMA init protocol
  x86-32, NUMA: Replace srat_32.c with srat.c
  x86-32, NUMA: implement temporary NUMA init shims
  x86, NUMA: Move numa_nodes_parsed to numa.[hc]
  x86-32, NUMA: Move get_memcfg_numa() into numa_32.c
  x86, NUMA: make srat.c 32bit safe
  x86, NUMA: rename srat_64.c to srat.c
  ...

For use in assembly constants, use the ASM_NOP* defines.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/1303166160-10315-2-git-send-email-hpa@linux.intel.com

Add this_cpu_has() which determines if the current cpu has a certain
ability using a segment prefix and a bit test operation.

For that we need to add bit operations to x86s percpu.h.

Many uses of cpu_has use a pointer passed to a function to determine
the current flags. That is no longer necessary after this patch.

However, this patch only converts the straightforward cases where
cpu_has is used with this_cpu_ptr. The rest is work for later.

-tj: Rolled up patch to add x86_ prefix and use percpu_read() instead
     of percpu_read_stable().

Signed-off-by: Christoph Lameter <cl@linux.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>

percpu_cmpxchg16b_double() uses alternative_io() and looks like :

e8 .. .. .. ..  call this_cpu_cmpxchg16b_emu
X bytes	    NOPX

or, once patched (if cpu supports native instruction) on SMP build :

65 48 0f c7 0e  cmpxchg16b %gs:(%rsi)
0f 94 c0        sete %al

on !SMP build :

48 0f c7 0e     cmpxchg16b (%rsi)
0f 94 c0        sete %al

Therefore, NOPX should be :

P6_NOP3 on SMP
P6_NOP2 on !SMP

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>

Omit the segment prefix in the UP case. GS is not used then
and we will generate segfaults if cmpxchg16b is used otherwise.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>