Linus noted that the atomic64_t primitives are all inlines
currently which is crazy because these functions have a large
register footprint anyway.

Move them to a separate file: arch/x86/lib/atomic64_32.c

Also, while at it, rename all uses of 'unsigned long long' to
the much shorter u64.

This makes the appearance of the prototypes a lot nicer - and
it also uncovered a few bugs where (yet unused) API variants
had 'long' as their return type instead of u64.

[ More intrusive changes are not yet done in this patch. ]
Reported-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
LKML-Reference: <alpine.LFD.2.01.0907021653030.3210@localhost.localdomain>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Locked instructions on two cache lines at once are painful. If
atomic64_t uses two cache lines, my test program is 10x slower.

The chance for that is significant: 4/32 or 12.5%.

Make sure an atomic64_t is 8 bytes aligned.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
LKML-Reference: <alpine.LFD.2.01.0907021653030.3210@localhost.localdomain>
[ changed it to __aligned(8) as per Andrew's suggestion ]
Signed-off-by: NIngo Molnar <mingo@elte.hu>

About every callchains recorded with perf record are filled up
including the internal perfcounter nmi frame:

 perf_callchain
 perf_counter_overflow
 intel_pmu_handle_irq
 perf_counter_nmi_handler
 notifier_call_chain
 atomic_notifier_call_chain
 notify_die
 do_nmi
 nmi

We want ignore this frame as it's not interesting for
instrumentation. To solve this, we simply ignore every frames
from nmi context.

New example of "perf report -s sym -c" after this patch:

9.59%  [k] search_by_key
             4.88%
                search_by_key
                reiserfs_read_locked_inode
                reiserfs_iget
                reiserfs_lookup
                do_lookup
                __link_path_walk
                path_walk
                do_path_lookup
                user_path_at
                vfs_fstatat
                vfs_lstat
                sys_newlstat
                system_call_fastpath
                __lxstat
                0x406fb1

             3.19%
                search_by_key
                search_by_entry_key
                reiserfs_find_entry
                reiserfs_lookup
                do_lookup
                __link_path_walk
                path_walk
                do_path_lookup
                user_path_at
                vfs_fstatat
                vfs_lstat
                sys_newlstat
                system_call_fastpath
                __lxstat
                0x406fb1
[...]

For now this patch only solves the problem in x86-64.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Anton Blanchard <anton@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <1246474930-6088-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

<asm/boot.h> needs <asm/pgtable_types.h>, not <asm/page_types.h> in
order to resolve PMD_SHIFT.  Also, correct a +1 which really should be
+ THREAD_ORDER.

This is a build error which was masked by a typoed #ifdef.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

CONFIG_X86_64 was misspelled (wrong case), which caused the x86-64
kernel to advertise itself as more relocatable than it really is.
This could in theory cause boot failures once bootloaders start
support the new relocation fields.
Signed-off-by: NRobert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Update the mmap control page with the needed information to
use the userspace RDPMC instruction for self monitoring.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This reverts commit 9e9f46c4.

Quoting from the commit message:

 "At this point, it seems to solve more problems than it causes, so let's
  try using it by default.  It's an easy revert if it ends up causing
  trouble."

And guess what? The _CRS code causes trouble.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

lpage allocator aliases a PMD page for each cpu and returns whatever
is unused to the page allocator.  When the pageattr of the recycled
pages are changed, this makes the two aliases point to the overlapping
regions with different attributes which isn't allowed and known to
cause subtle data corruption in certain cases.

This can be handled in simliar manner to the x86_64 highmap alias.
pageattr code should detect if the target pages have PMD alias and
split the PMD alias and synchronize the attributes.

pcpur allocator is updated to keep the allocated PMD pages map sorted
in ascending address order and provide pcpu_lpage_remapped() function
which binary searches the array to determine whether the given address
is aliased and if so to which address.  pageattr is updated to use
pcpu_lpage_remapped() to detect the PMD alias and split it up as
necessary from cpa_process_alias().

Jan Beulich spotted the original problem and incorrect usage of vaddr
instead of laddr for lookup.

With this, lpage percpu allocator should work correctly.  Re-enable
it.

[ Impact: fix subtle lpage pageattr bug and re-enable lpage ]
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NJan Beulich <JBeulich@novell.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>

The discussion about using "access_ok()" in get_user_pages_fast() (see
commit 7f818906: "x86: don't use
'access_ok()' as a range check in get_user_pages_fast()" for details and
end result), made us notice that x86-64 was really being very sloppy
about virtual address checking.

So be way more careful and straightforward about masking x86-64 virtual
addresses:

 - All the VIRTUAL_MASK* variants now cover half of the address
   space, it's not like we can use the full mask on a signed
   integer, and the larger mask just invites mistakes when
   applying it to either half of the 48-bit address space.

 - /proc/kcore's kc_offset_to_vaddr() becomes a lot more
   obvious when it transforms a file offset into a
   (kernel-half) virtual address.

 - Unify/simplify the 32-bit and 64-bit USER_DS definition to
   be based on TASK_SIZE_MAX.

This cleanup and more careful/obvious user virtual address checking also
uncovered a buglet in the x86-64 implementation of strnlen_user(): it
would do an "access_ok()" check on the whole potential area, even if the
string itself was much shorter, and thus return an error even for valid
strings. Our sloppy checking had hidden this.

So this fixes 'strnlen_user()' to do this properly, the same way we
already handled user strings in 'strncpy_from_user()'.  Namely by just
checking the first byte, and then relying on fault handling for the
rest.  That always works, since we impose a guard page that cannot be
mapped at the end of the user space address space (and even if we
didn't, we'd have the address space hole).
Acked-by: NIngo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Improve a few details in perfcounter call-chain recording that
makes use of fast-GUP:

- Use ACCESS_ONCE() to observe the pte value. ptes are fundamentally
  racy and can be changed on another CPU, so we have to be careful
  about how we access them. The PAE branch is already careful with
  read-barriers - but the non-PAE and 64-bit side needs an
  ACCESS_ONCE() to make sure the pte value is observed only once.

- make the checks a bit stricter so that we can feed it any kind of
  cra^H^H^H user-space input ;-)
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: NJoerg Roedel <joerg.roedel@amd.com>
Acked-by: NIngo Molnar <mingo@elte.hu>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

asm/desc.h is included in three assembly files, but the only macro
it defines, GET_DESC_BASE, is never used. This patch removes the
includes, removes the macro GET_DESC_BASE and the ASSEMBLY guard
from asm/desc.h.
Signed-off-by: NAlexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

<linux/types.h> is only required for __KERNEL__ as whole file is covered with it

Also fixed some spacing issues for usr/include/asm-x86/msr.h
Signed-off-by: NJaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: "H. Peter Anvin" <hpa@kernel.org>
LKML-Reference: <1245228070.2662.1.camel@ht.satnam>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

For freqency dependent TSCs we only scale the cycles, we do not account
for the discrepancy in absolute value.

Our current formula is: time = cycles * mult

(where mult is a function of the cpu-speed on variable tsc machines)

Suppose our current cycle count is 10, and we have a multiplier of 5,
then our time value would end up being 50.

Now cpufreq comes along and changes the multiplier to say 3 or 7,
which would result in our time being resp. 30 or 70.

That means that we can observe random jumps in the time value due to
frequency changes in both fwd and bwd direction.

So what this patch does is change the formula to:

  time = cycles * frequency + offset

And we calculate offset so that time_before == time_after, thereby
ridding us of these jumps in time.

[ Impact: fix/reduce sched_clock() jumps across frequency changing events ]
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Chucked-on-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Convert most arches to use asm-generic/kmap_types.h.

Move the KM_FENCE_ macro additions into asm-generic/kmap_types.h,
controlled by __WITH_KM_FENCE from each arch's kmap_types.h file.

Would be nice to be able to add custom KM_types per arch, but I don't yet
see a nice, clean way to do that.

Built on x86_64, i386, mips, sparc, alpha(tonyb), powerpc(tonyb), and
68k(tonyb).

Note: avr32 should be able to remove KM_PTE2 (since it's not used) and
then just use the generic kmap_types.h file.  Get avr32 maintainer
approval.
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Cc: <linux-arch@vger.kernel.org>
Acked-by: NMike Frysinger <vapier@gentoo.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Bryan Wu <cooloney@kernel.org>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: "Luck Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

PIT_TICK_RATE is currently defined in four architectures, but in three
different places.  While linux/timex.h is not the perfect place for it, it
is still a reasonable replacement for those drivers that traditionally use
asm/timex.h to get CLOCK_TICK_RATE and expect it to be the PIT frequency.

Note that for Alpha, the actual value changed from 1193182UL to 1193180UL.
 This is unlikely to make a difference, and probably can only improve
accuracy.  There was a discussion on the correct value of CLOCK_TICK_RATE
a few years ago, after which every existing instance was getting changed
to 1193182.  According to the specification, it should be
1193181.818181...
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Len Brown <lenb@kernel.org>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Dmitry Torokhov <dtor@mail.ru>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Reorder definitions.

 - static inline dummy mcheck_init() for !CONFIG_X86_MCE
 - gather defs for exception, threshold handler
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Now all symbols in the header are static.  Remove the header.
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

and make intel_thermal_interrupt() static.
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Let them in same shape.
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

The mce_disabled on 32bit is a tristate variable [1,0,-1],
while 64bit version is boolean [0,1].
This patch makes mce_disabled always boolean, and use mce_p5_enabled
to indicate the third state instead.
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

There are 2 headers:
	arch/x86/include/asm/mce.h
	arch/x86/kernel/cpu/mcheck/mce.h
and in the latter small header:
	#include <asm/mce.h>

This patch move all contents in the latter header into the former,
and fix all files using the latter to include the former instead.
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

I just realized this has a kmap_atomic bug in...

The below would fix it - but it's complicating this code
some more.

Alternatively I would have to introduce something like
pte_offset_map_irq() which would make the irq/nmi detection and leave
the regular code paths alone, however that would mean either duplicating
the gup_fast() pagewalk or passing down a pte function pointer, which
would only duplicate the gup_pte_range() bit, neither is really
attractive ...
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
CC: Nick Piggin <npiggin@suse.de>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

At present, every architecture that supports perf_counters has to
declare set_perf_counter_pending() in its arch-specific headers.
This consolidates the declarations into a single declaration in one
common place, include/linux/perf_counter.h.  On powerpc, we continue
to provide a static inline definition of set_perf_counter_pending()
in the powerpc hw_irq.h.

Also, this removes from the x86 perf_counter.h the unused null
definitions of {test,clear}_perf_counter_pending.
Reported-by: NMike Frysinger <vapier.adi@gmail.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: benh@kernel.crashing.org
LKML-Reference: <18998.13388.920691.523227@cargo.ozlabs.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Two new kmap_atomic slots for NMI context. And teach pte_offset_map()
about NMI context.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
CC: Nick Piggin <npiggin@suse.de>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Unify and demacro pte_hidden.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

[rebased for mainline inclusion]
Signed-off-by: NVegard Nossum <vegard.nossum@gmail.com>

Only _PAGE_HIDDEN when CONFIG_KMEMCHECK is defined, otherwise set it
to 0.  Allows later cleanups.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

[rebased for mainline inclusion]
Signed-off-by: NVegard Nossum <vegard.nossum@gmail.com>

This adds support for tracking the initializedness of memory that
was allocated with the page allocator. Highmem requests are not
tracked.

Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: NPekka Enberg <penberg@cs.helsinki.fi>

[build fix for !CONFIG_KMEMCHECK]
Signed-off-by: NIngo Molnar <mingo@elte.hu>

[rebased for mainline inclusion]
Signed-off-by: NVegard Nossum <vegard.nossum@gmail.com>

When the IOMMU stays enabled the BIOS may not be able to finish the
machine shutdown properly. So disable the hardware on shutdown.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

This is needed for page allocator support to prevent false positives
when accessing pages which are dma-mapped.

[rebased for mainline inclusion]
Signed-off-by: NVegard Nossum <vegard.nossum@gmail.com>

This patch hooks into the DMA API to prevent the reporting of the
false positives that would otherwise be reported when memory is
accessed that is also used directly by devices.

[rebased for mainline inclusion]
Signed-off-by: NVegard Nossum <vegard.nossum@gmail.com>

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>

Fix kernel-doc warnings in atomic_32.h:

  Warning(arch/x86/include/asm/atomic_32.h:265): No description found for parameter 'ptr'
  Warning(arch/x86/include/asm/atomic_32.h:265): Excess function parameter 'v' description in '__atomic64_read'
  Warning(arch/x86/include/asm/atomic_32.h:305): Excess function parameter 'old_val' description in 'atomic64_xchg'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
LKML-Reference: <4A3467E6.6010907@oracle.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

General description: kmemcheck is a patch to the linux kernel that
detects use of uninitialized memory. It does this by trapping every
read and write to memory that was allocated dynamically (e.g. using
kmalloc()). If a memory address is read that has not previously been
written to, a message is printed to the kernel log.

Thanks to Andi Kleen for the set_memory_4k() solution.

Andrew Morton suggested documenting the shadow member of struct page.
Signed-off-by: NVegard Nossum <vegardno@ifi.uio.no>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

[export kmemcheck_mark_initialized]
[build fix for setup_max_cpus]
Signed-off-by: NIngo Molnar <mingo@elte.hu>

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

SFI will need to test acpi_disabled no matter
the value of CONFIG_ACPI.
Signed-off-by: NLen Brown <len.brown@intel.com>

Move
arch/x86/kernel/acpi/boot.c: acpi_parse_mcfg()
to
arch/x86/pci/mmconfig-shared.c: pci_parse_mcfg()
where it is used, and make it static.

Move associated globals and helper routine with it.

No functional change.

This code move is in preparation for SFI support,
which will allow the PCI code to find the MCFG table
on systems which do not support ACPI.
Signed-off-by: NLen Brown <len.brown@intel.com>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>

This version requires that host and guest have the same PAE status.
NX cap is not offered to the guest, yet.
Signed-off-by: NMatias Zabaljauregui <zabaljauregui@gmail.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Add support for kvm_hypercall4(); PAE wants it.

Signed-off-by: Matias Zabaljauregui <zabaljauregui at gmail.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

replace LHCALL_SET_PMD with LHCALL_SET_PGD hypercall name
(That's really what it is, and the confusion gets worse with PAE support)
Signed-off-by: NMatias Zabaljauregui <zabaljauregui@gmail.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Reported-by: NJeremy Fitzhardinge <jeremy@goop.org>

lguest never checked for pending interrupts when enabling interrupts, and
things still worked.  However, it makes a significant difference to TCP
performance, so it's time we fixed it by introducing a pending_irq flag
and checking it on irq_restore and irq_enable.

These two routines are now too big to patch into the 8/10 bytes
patch space, so we drop that code.

Note: The high latency on interrupt delivery had a very curious
effect: once everything else was optimized, networking without GSO was
faster than networking with GSO, since more interrupts were sent and
hence a greater chance of one getting through to the Guest!

Note2: (Almost) Closing the same loophole for iret doesn't have any
measurable effect, so I'm leaving that patch for the moment.

Before:
	1GB tcpblast Guest->Host:		30.7 seconds
	1GB tcpblast Guest->Host (no GSO):	76.0 seconds

After:
	1GB tcpblast Guest->Host:		6.8 seconds
	1GB tcpblast Guest->Host (no GSO):	27.8 seconds
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>