It is assumed that rcu won't be used once we switch to tickless
mode and until we restart the tick. However this is not always
true, as in x86-64 where we dereference the idle notifiers after
the tick is stopped.
To prepare for fixing this, add two new APIs:
tick_nohz_idle_enter_norcu() and tick_nohz_idle_exit_norcu().
If no use of RCU is made in the idle loop between
tick_nohz_enter_idle() and tick_nohz_exit_idle() calls, the arch
must instead call the new *_norcu() version such that the arch doesn't
need to call rcu_idle_enter() and rcu_idle_exit().
Otherwise the arch must call tick_nohz_enter_idle() and
tick_nohz_exit_idle() and also call explicitly:
- rcu_idle_enter() after its last use of RCU before the CPU is put
to sleep.
- rcu_idle_exit() before the first use of RCU after the CPU is woken
up.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: David Miller <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The tick_nohz_stop_sched_tick() function, which tries to delay
the next timer tick as long as possible, can be called from two
places:
- From the idle loop to start the dytick idle mode
- From interrupt exit if we have interrupted the dyntick
idle mode, so that we reprogram the next tick event in
case the irq changed some internal state that requires this
action.
There are only few minor differences between both that
are handled by that function, driven by the ts->inidle
cpu variable and the inidle parameter. The whole guarantees
that we only update the dyntick mode on irq exit if we actually
interrupted the dyntick idle mode, and that we enter in RCU extended
quiescent state from idle loop entry only.
Split this function into:
- tick_nohz_idle_enter(), which sets ts->inidle to 1, enters
dynticks idle mode unconditionally if it can, and enters into RCU
extended quiescent state.
- tick_nohz_irq_exit() which only updates the dynticks idle mode
when ts->inidle is set (ie: if tick_nohz_idle_enter() has been called).
To maintain symmetry, tick_nohz_restart_sched_tick() has been renamed
into tick_nohz_idle_exit().
This simplifies the code and micro-optimize the irq exit path (no need
for local_irq_save there). This also prepares for the split between
dynticks and rcu extended quiescent state logics. We'll need this split to
further fix illegal uses of RCU in extended quiescent states in the idle
loop.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: David Miller <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Some of the sun4v code patching occurs in inline functions visible
to, and usable by, modules.
Therefore we have to patch them up during module load.
Signed-off-by: David S. Miller <davem@davemloft.net>
To handle the large physical addresses, just make a simple wrapper
around remap_pfn_range() like MIPS does.
Signed-off-by: David S. Miller <davem@davemloft.net>
As per the comments added by this commit, %g2 turns out to not be a
usable place to save away orig_i0 for syscall restart handling.
In fact all of %g2, %g3, %g4, and %g5 are assumed to be saved across
a system call by various bits of code in glibc.
%g1 can't be used because that holds the syscall number, which would
need to be saved and restored for syscall restart handling too, and
that would only compound our problems :-)
This leaves us with %g6 and %g7 which are for "system use". %g7 is
used as the "thread register" by glibc, but %g6 is used as a compiler
and assembler temporary scratch register. And in no instance is %g6
used to hold a value across a system call.
Therefore %g6 is safe for storing away orig_i0, at least for now.
Signed-off-by: David S. Miller <davem@davemloft.net>
Although we provide a proper way for a debugger to control whether
syscall restart occurs, we run into problems because orig_i0 is not
saved and restored properly.
Luckily we can solve this problem without having to make debuggers
aware of the issue. Across system calls, several registers are
considered volatile and can be safely clobbered.
Therefore we use the pt_regs save area of one of those registers, %g2,
as a place to save and restore orig_i0.
Debuggers transparently will do the right thing because they save and
restore this register already.
Signed-off-by: David S. Miller <davem@davemloft.net>
This file introduced in 2.6.32.47 currently fails to compile:
arch/sparc/kernel/sigutil_64.c: In function 'save_fpu_state':
arch/sparc/kernel/sigutil_64.c:25: error: 'EFAULT' undeclared (first use in this function)
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
* 'upstream/jump-label-noearly' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen:
jump-label: initialize jump-label subsystem much earlier
x86/jump_label: add arch_jump_label_transform_static()
s390/jump-label: add arch_jump_label_transform_static()
jump_label: add arch_jump_label_transform_static() to optimise non-live code updates
sparc/jump_label: drop arch_jump_label_text_poke_early()
x86/jump_label: drop arch_jump_label_text_poke_early()
jump_label: if a key has already been initialized, don't nop it out
stop_machine: make stop_machine safe and efficient to call early
jump_label: use proper atomic_t initializer
Conflicts:
- arch/x86/kernel/jump_label.c
Added __init_or_module to arch_jump_label_text_poke_early vs
removal of that function entirely
- kernel/stop_machine.c
same patch ("stop_machine: make stop_machine safe and efficient
to call early") merged twice, with whitespace fix in one version
* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
Revert "tracing: Include module.h in define_trace.h"
irq: don't put module.h into irq.h for tracking irqgen modules.
bluetooth: macroize two small inlines to avoid module.h
ip_vs.h: fix implicit use of module_get/module_put from module.h
nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
include: replace linux/module.h with "struct module" wherever possible
include: convert various register fcns to macros to avoid include chaining
crypto.h: remove unused crypto_tfm_alg_modname() inline
uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
pm_runtime.h: explicitly requires notifier.h
linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
miscdevice.h: fix up implicit use of lists and types
stop_machine.h: fix implicit use of smp.h for smp_processor_id
of: fix implicit use of errno.h in include/linux/of.h
of_platform.h: delete needless include <linux/module.h>
acpi: remove module.h include from platform/aclinux.h
miscdevice.h: delete unnecessary inclusion of module.h
device_cgroup.h: delete needless include <linux/module.h>
net: sch_generic remove redundant use of <linux/module.h>
net: inet_timewait_sock doesnt need <linux/module.h>
...
Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in
- drivers/media/dvb/frontends/dibx000_common.c
- drivers/media/video/{mt9m111.c,ov6650.c}
- drivers/mfd/ab3550-core.c
- include/linux/dmaengine.h
* 'trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
scsi: drop unused Kconfig symbol
pci: drop unused Kconfig symbol
stmmac: drop unused Kconfig symbol
x86: drop unused Kconfig symbol
powerpc: drop unused Kconfig symbols
powerpc: 40x: drop unused Kconfig symbol
mips: drop unused Kconfig symbols
openrisc: drop unused Kconfig symbols
arm: at91: drop unused Kconfig symbol
samples: drop unused Kconfig symbol
m32r: drop unused Kconfig symbol
score: drop unused Kconfig symbols
sh: drop unused Kconfig symbol
um: drop unused Kconfig symbol
sparc: drop unused Kconfig symbol
alpha: drop unused Kconfig symbol
Fix up trivial conflict in drivers/net/ethernet/stmicro/stmmac/Kconfig
as per Michal: the STMMAC_DUAL_MAC config variable is still unused and
should be deleted.
This avoids duplicating the function in every arch gup_fast.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Up to this point the code assumed old refcounting for hugepages (pre-thp).
This updates the code directly to the thp mapcount tail page refcounting.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The file mm/extable.c needs module.h for within_module_init(), and
also for search_exception_tables [which arguably could be living somewhere
more appropriate than module.h] - eventually causing this:
arch/sparc/mm/extable.c: In function 'trim_init_extable':
arch/sparc/mm/extable.c:74: error: dereferencing pointer to incomplete type
arch/sparc/mm/extable.c:75: error: dereferencing pointer to incomplete type
arch/sparc/mm/extable.c:77: error: implicit declaration of function 'within_module_init'
arch/sparc/mm/extable.c:77: error: dereferencing pointer to incomplete type
arch/sparc/mm/extable.c:78: error: dereferencing pointer to incomplete type
arch/sparc/mm/extable.c:80: error: dereferencing pointer to incomplete type
arch/sparc/mm/extable.c: In function 'search_extables_range':
arch/sparc/mm/extable.c:93: error: implicit declaration of function 'search_exception_tables'
The other instances are more straight forward uses of things
like MODULE_* and module_*
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Building an allyesconfig doesn't reveal a hidden need
for any of these. Since module.h brings in the whole kitchen
sink, it just needlessly adds 30k+ lines to the cpp burden.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Many of the core sparc kernel files are not modules, but just
including module.h for exporting symbols. Now these files can
use the lighter footprint export.h for this role.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
These files are only exporting symbols, so they don't need
the full module.h header file. Previously they were getting
access to EXPORT_SYMBOL implicitly via overuse of module.h
from within other .h files, but that is being cleaned up.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Building sparc64 with the module.h cleanup reveals this implicit
include being taken advantage of:
arch/sparc/kernel/mdesc.c: In function 'mdesc_read':
arch/sparc/kernel/mdesc.c:900: error: implicit declaration of function 'copy_to_user'
Fix it up before the implicit module.h presence is removed.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
To resolve these on 64bit allnoconfig builds:
CC arch/sparc/kernel/pcr.o
arch/sparc/kernel/pcr.c: In function 'register_perf_hsvc':
arch/sparc/kernel/pcr.c:102: error: 'tlb_type' undeclared (first use in this function)
CC arch/sparc/kernel/of_device_64.o
arch/sparc/kernel/of_device_64.c: In function 'build_device_resources':
arch/sparc/kernel/of_device_64.c:406: error: 'tlb_type' undeclared (first use in this function)
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
sparc64: Fix masking and shifting in VIS fpcmp emulation.
sparc32: Correct the return value of memcpy.
sparc32: Remove uses of %g7 in memcpy implementation.
sparc32: Remove non-kernel code from memcpy implementation.
This was found by inspection while tracking a similar
bug in compat_statfs64, that has been fixed in mainline
since decemeber.
- This fixes a bug where not all of the f_spare fields
were cleared on mips and s390.
- Add the f_flags field to struct compat_statfs
- Copy f_flags to userspace in case someone cares.
- Use __clear_user to copy the f_spare field to userspace
to ensure that all of the elements of f_spare are cleared.
On some architectures f_spare is has 5 ints and on some
architectures f_spare only has 4 ints. Which makes
the previous technique of clearing each int individually
broken.
I don't expect anyone actually uses the old statfs system
call anymore but if they do let them benefit from having
the compat and the native version working the same.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
It is no longer used.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Jason Baron <jbaron@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: David Miller <davem@davemloft.net>
Properly return the original destination buffer pointer.
Signed-off-by: David S. Miller <davem@davemloft.net>
Tested-by: Kjetil Oftedal <oftedal@gmail.com>
This is setting things up so that we can correct the return
value, so that it properly returns the original destination
buffer pointer.
Signed-off-by: David S. Miller <davem@davemloft.net>
Tested-by: Kjetil Oftedal <oftedal@gmail.com>
Currently no type of alignment is specified for PCI expansion roms while
parsing the openfirmware tree. This causes calls to pci_map_rom() to fail.
IORESOURCE_SIZEALIGN is the default alignment used for rom resouces in
pci/probe.c, and has been verified to work with various cards on a ultra 10.
Signed-off-By: Kjetil Oftedal <oftedal@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As described in e6fa16ab ("signal: sigprocmask() should do
retarget_shared_pending()") the modification of current->blocked is
incorrect as we need to check whether the signal we're about to block
is pending in the shared queue.
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The LEON MMU Model (SRMMU) does not implement MMu Table probing
in hardware, instead it is implemented in software. However the
software implementation does not return the PTE as it should which
always results in INVALID entires and the PROM mappings are not
inherited as they should during startup. The following patch
removes the masking of the PTE.
Signed-off-by: Daniel Hellstrom <daniel@gaisler.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In the OF 'translations' property, the template TTEs in the mappings
never specify the executable bit. This is the case even though some
of these mappings are for OF's code segment.
Therefore, we need to force the execute bit on in every mapping.
This problem can only really trigger on Niagara/sun4v machines and the
history behind this is a little complicated.
Previous to sun4v, the sun4u TTE entries lacked a hardware execute
permission bit. So OF didn't have to ever worry about setting
anything to handle executable pages. Any valid TTE loaded into the
I-TLB would be respected by the chip.
But sun4v Niagara chips have a real hardware enforced executable bit
in their TTEs. So it has to be set or else the I-TLB throws an
instruction access exception with type code 6 (protection violation).
We've been extremely fortunate to not get bitten by this in the past.
The best I can tell is that the OF's mappings for it's executable code
were mapped using permanent locked mappings on sun4v in the past.
Therefore, the fact that we didn't have the exec bit set in the OF
translations we would use did not matter in practice.
Thanks to Greg Onufer for helping me track this down.
Signed-off-by: David S. Miller <davem@davemloft.net>
If "-p" is given on the command line, clear the CON_BOOT
flag for the initial early boot PROM console.
This is necessary to try and see crash messages that occur
between the registry of the VT console and the probing of
the first framebuffer or serial console. During this time
no console messages are emitted because the VT console
registry (even if no backend is registered to it) removes
the early console if CON_BOOT is set.
Signed-off-by: David S. Miller <davem@davemloft.net>
The address limit is already set in flush_old_exec() so this assignment of
USER_DS is redundant.
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Recognize T4 and T5 chips. Treating them both as "T2 plus other
stuff" should be extremely safe and make sure distributions will work
when those chips actually ship to customers.
Signed-off-by: David S. Miller <davem@davemloft.net>
On Sun4d systems running in SMP mode, IRQ 14 is used for timer interrupts
and has a specialized interrupt handler. IPI is currently set to use IRQ 14
as well, which causes it to trigger the timer interrupt handler, and not the
IPI interrupt handler.
The IPI interrupt is therefore changed to IRQ 13, which is the highest
normally handled interrupt. This IRQ is also used for SBUS interrupts,
however there is nothing in the IPI/SBUS interrupt handlers that indicate
that they will not handle sharing the interrupt.
(IRQ 13 is indicated as audio interrupt, which is unlikely to be found in a
sun4d system)
Signed-off-by: Kjetil Oftedal <oftedal@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The nfsservctl system call is now gone, so we should remove all
linkage for it.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If we can't push the pending register windows onto the user's stack,
we disallow signal delivery even if the signal would be delivered on a
valid seperate signal stack.
Add a register window save area in the signal frame, and store any
unsavable windows there.
On sigreturn, if any windows are still queued up in the signal frame,
try to push them back onto the stack and if that fails we kill the
process immediately.
This allows the debug/tst-longjmp_chk2 glibc test case to pass.
Signed-off-by: David S. Miller <davem@davemloft.net>
CC arch/sparc/kernel/pcic.o
arch/sparc/kernel/pcic.c: In function 'pcic_probe':
arch/sparc/kernel/pcic.c:359:33: error: array subscript is above array bounds [-Werror=array-bounds]
arch/sparc/kernel/pcic.c:359:8: error: array subscript is above array bounds [-Werror=array-bounds]
arch/sparc/kernel/pcic.c:360:33: error: array subscript is above array bounds [-Werror=array-bounds]
arch/sparc/kernel/pcic.c:360:8: error: array subscript is above array bounds [-Werror=array-bounds]
arch/sparc/kernel/pcic.c:361:33: error: array subscript is above array bounds [-Werror=array-bounds]
arch/sparc/kernel/pcic.c:361:8: error: array subscript is above array bounds [-Werror=array-bounds]
cc1: all warnings being treated as errors
I'm not particularly familiar with sparc but t_nmi (defined in head_32.S via
the TRAP_ENTRY macro) and pcic_nmi_trap_patch (defined in entry.S) both appear
to be 4 instructions long and I presume from the usage that instructions are
int sized.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The sparc32 version of arch_write_unlock() is just a plain assignment.
Unfortunately this allows the compiler to schedule side-effects in a
protected region to occur after the HW-level unlock, which is broken.
E.g., the following trivial test case gets miscompiled:
#include <linux/spinlock.h>
rwlock_t lock;
int counter;
void foo(void) { write_lock(&lock); ++counter; write_unlock(&lock); }
Fixed by adding a compiler memory barrier to arch_write_unlock(). The
sparc64 version combines the barrier and assignment into a single asm(),
and implements the operation as a static inline, so that's what I did too.
Compile-tested with sparc32_defconfig + CONFIG_SMP=y.
Signed-off-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: David S. Miller <davem@davemloft.net>
The sparc64 spinlock_64.h contains a number of operations defined
first as static inline functions, and then as macros with the same
names and parameters as the functions. Maybe this was needed at
some point in the past, but now nothing seems to depend on these
macros (checked with a recursive grep looking for ifdefs on these
names). Other archs don't define these identity-macros.
So this patch deletes these unnecessary macros.
Compile-tested with sparc64_defconfig.
Signed-off-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: David S. Miller <davem@davemloft.net>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
sparc: Size mondo queues more sanely.
sparc: Access kernel TSB using physical addressing when possible.
sparc: Fix __atomic_add_unless() return value.
sparc: use kbuild-generic support for true asm-generic header files
sparc: Use popc when possible for ffs/__ffs/ffz.
sparc: Set reboot-cmd using reboot data hypervisor call if available.
sparc: Add some missing hypervisor API groups.
sparc: Use hweight64() in popc emulation.
sparc: Use popc if possible for hweight routines.
sparc: Minor tweaks to Niagara page copy/clear.
sparc: Sanitize cpu feature detection and reporting.
There is currently no upper limit on the mondo queue sizes we'll use,
which guarentees that we'll eventually his page allocation limits, and
thus allocation failures, due to MAX_ORDER.
Cap the sizes sanely, current limits are:
CPU MONDO 2 * max_possible_cpus
DEV MONDO 256 (basically NR_IRQS)
RES MONDO 128
NRES MONDO 4
Signed-off-by: David S. Miller <davem@davemloft.net>
On sun4v this is basically required since we point the hypervisor and
the TSB walking hardware at these tables using physical addressing
too.
Signed-off-by: David S. Miller <davem@davemloft.net>