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  1. 18 12月, 2014 2 次提交
    • G
      powerpc/powernv: Ignore smt-enabled on Power8 and later · d70a54e2
      由 Greg Kurz 提交于 
      Starting with POWER8, the subcore logic relies on all threads of a core
being booted so that they can participate in split mode switches. So on
those machines we ignore the smt_enabled_at_boot setting (smt-enabled on
the kernel command line).
Signed-off-by: NGreg Kurz <gkurz@linux.vnet.ibm.com>
[mpe: Update comment and change log to be more precise]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      d70a54e2
    • M
      powerpc/uaccess: Allow get_user() with bitwise types · 505e4283
      由 Michael S. Tsirkin 提交于 
      At the moment, if p and x are both of the same bitwise type
(eg. __le32), get_user(x, p) produces a sparse warning.

This is because *p is loaded into a long then cast back to typeof(*p).

When typeof(*p) is a bitwise type (which is uncommon), such a cast needs
__force, otherwise sparse produces a warning.

For non-bitwise types __force should have no effect, and should not hide
any legitimate errors.

Note that we are casting to typeof(*p) not typeof(x). Even with the
cast, if x and *p are of different types we should get the warning, so I
think we are not loosing the ability to detect any actual errors.

virtio would like to use bitwise types with get_user() so fix these
spurious warnings by adding __force.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
[mpe: Fill in changelog with more details]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      505e4283
  3. 15 12月, 2014 5 次提交
    • B
      powerpc/powernv: Expose OPAL firmware symbol map · c8742f85
      由 Benjamin Herrenschmidt 提交于 
      Newer versions of OPAL will provide this, so let's expose it to user
space so tools like perf can use it to properly decode samples in
firmware space.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      c8742f85
    • S
      powernv/powerpc: Add winkle support for offline cpus · 77b54e9f
      由 Shreyas B. Prabhu 提交于 
      Winkle is a deep idle state supported in power8 chips. A core enters
winkle when all the threads of the core enter winkle. In this state
power supply to the entire chiplet i.e core, private L2 and private L3
is turned off. As a result it gives higher powersavings compared to
sleep.

But entering winkle results in a total hypervisor state loss. Hence the
hypervisor context has to be preserved before entering winkle and
restored upon wake up.

Power-on Reset Engine (PORE) is a dedicated engine which is responsible
for powering on the chiplet during wake up. It can be programmed to
restore the register contests of a few specific registers. This patch
uses PORE to restore register state wherever possible and uses stack to
save and restore rest of the necessary registers.

With hypervisor state restore things fall under three categories-
per-core state, per-subcore state and per-thread state. To manage this,
extend the infrastructure introduced for sleep. Mainly we add a paca
variable subcore_sibling_mask. Using this and the core_idle_state we can
distingush first thread in core and subcore.
Signed-off-by: NShreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      77b54e9f
    • S
      powernv/cpuidle: Redesign idle states management · 7cba160a
      由 Shreyas B. Prabhu 提交于 
      Deep idle states like sleep and winkle are per core idle states. A core
enters these states only when all the threads enter either the
particular idle state or a deeper one. There are tasks like fastsleep
hardware bug workaround and hypervisor core state save which have to be
done only by the last thread of the core entering deep idle state and
similarly tasks like timebase resync, hypervisor core register restore
that have to be done only by the first thread waking up from these
state.

The current idle state management does not have a way to distinguish the
first/last thread of the core waking/entering idle states. Tasks like
timebase resync are done for all the threads. This is not only is
suboptimal, but can cause functionality issues when subcores and kvm is
involved.

This patch adds the necessary infrastructure to track idle states of
threads in a per-core structure. It uses this info to perform tasks like
fastsleep workaround and timebase resync only once per core.
Signed-off-by: NShreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Originally-by: NPreeti U. Murthy <preeti@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: linux-pm@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      7cba160a
    • S
      powerpc/powernv: Enable Offline CPUs to enter deep idle states · 8eb8ac89
      由 Shreyas B. Prabhu 提交于 
      The secondary threads should enter deep idle states so as to gain maximum
powersavings when the entire core is offline. To do so the offline path
must be made aware of the available deepest idle state. Hence probe the
device tree for the possible idle states in powernv core code and
expose the deepest idle state through flags.

Since the  device tree is probed by the cpuidle driver as well, move
the parameters required to discover the idle states into an appropriate
common place to both the driver and the powernv core code.

Another point is that fastsleep idle state may require workarounds in
the kernel to function properly. This workaround is introduced in the
subsequent patches. However neither the cpuidle driver or the hotplug
path need be bothered about this workaround.

They will be taken care of by the core powernv code.
Originally-by: NSrivatsa S. Bhat <srivatsa@mit.edu>
Signed-off-by: NPreeti U. Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: NShreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Reviewed-by: NPaul Mackerras <paulus@samba.org>

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: linux-pm@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      8eb8ac89
    • P
      powerpc/powernv: Switch off MMU before entering nap/sleep/rvwinkle mode · 8117ac6a
      由 Paul Mackerras 提交于 
      Currently, when going idle, we set the flag indicating that we are in
nap mode (paca->kvm_hstate.hwthread_state) and then execute the nap
(or sleep or rvwinkle) instruction, all with the MMU on.  This is bad
for two reasons: (a) the architecture specifies that those instructions
must be executed with the MMU off, and in fact with only the SF, HV, ME
and possibly RI bits set, and (b) this introduces a race, because as
soon as we set the flag, another thread can switch the MMU to a guest
context.  If the race is lost, this thread will typically start looping
on relocation-on ISIs at 0xc...4400.

This fixes it by setting the MSR as required by the architecture before
setting the flag or executing the nap/sleep/rvwinkle instruction.

Cc: stable@vger.kernel.org
[ shreyas@linux.vnet.ibm.com: Edited to handle LE ]
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NShreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      8117ac6a
  5. 14 12月, 2014 1 次提交
  7. 12 12月, 2014 6 次提交
  9. 09 12月, 2014 1 次提交
    • A
      powerpc: Secondary CPUs must set cpu_callin_map after setting active and online · 7c5c92ed
      由 Anton Blanchard 提交于 
      I have a busy ppc64le KVM box where guests sometimes hit the infamous
"kernel BUG at kernel/smpboot.c:134!" issue during boot:

  BUG_ON(td->cpu != smp_processor_id());

Basically a per CPU hotplug thread scheduled on the wrong CPU. The oops
output confirms it:

  CPU: 0
  Comm: watchdog/130

The problem is that we aren't ensuring the CPU active and online bits are set
before allowing the master to continue on. The master unparks the secondary
CPUs kthreads and the scheduler looks for a CPU to run on. It calls
select_task_rq and realises the suggested CPU is not in the cpus_allowed
mask. It then ends up in select_fallback_rq, and since the active and
online bits aren't set we choose some other CPU to run on.

Cc: stable@vger.kernel.org
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      7c5c92ed
  11. 08 12月, 2014 1 次提交
    • P
      powerpc/powernv: Return to cpu offline loop when finished in KVM guest · 56548fc0
      由 Paul Mackerras 提交于 
      When a secondary hardware thread has finished running a KVM guest, we
currently put that thread into nap mode using a nap instruction in
the KVM code.  This changes the code so that instead of doing a nap
instruction directly, we instead cause the call to power7_nap() that
put the thread into nap mode to return.  The reason for doing this is
to avoid having the KVM code having to know what low-power mode to
put the thread into.

In the case of a secondary thread used to run a KVM guest, the thread
will be offline from the point of view of the host kernel, and the
relevant power7_nap() call is the one in pnv_smp_cpu_disable().
In this case we don't want to clear pending IPIs in the offline loop
in that function, since that might cause us to miss the wakeup for
the next time the thread needs to run a guest.  To tell whether or
not to clear the interrupt, we use the SRR1 value returned from
power7_nap(), and check if it indicates an external interrupt.  We
arrange that the return from power7_nap() when we have finished running
a guest returns 0, so pending interrupts don't get flushed in that
case.

Note that it is important a secondary thread that has finished
executing in the guest, or that didn't have a guest to run, should
not return to power7_nap's caller while the kvm_hstate.hwthread_req
flag in the PACA is non-zero, because the return from power7_nap
will reenable the MMU, and the MMU might still be in guest context.
In this situation we spin at low priority in real mode waiting for
hwthread_req to become zero.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      56548fc0
  13. 05 12月, 2014 2 次提交
    • M
      powerpc/book3s: Fix partial invalidation of TLBs in MCE code. · 682e77c8
      由 Mahesh Salgaonkar 提交于 
      The existing MCE code calls flush_tlb hook with IS=0 (single page) resulting
in partial invalidation of TLBs which is not right. This patch fixes
that by passing IS=0xc00 to invalidate whole TLB for successful recovery
from TLB and ERAT errors.

Cc: stable@vger.kernel.org
Signed-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      682e77c8
    • A
      powerpc/mm: don't do tlbie for updatepp request with NO HPTE fault · aefa5688
      由 Aneesh Kumar K.V 提交于 
      upatepp can get called for a nohpte fault when we find from the linux
page table that the translation was hashed before. In that case
we are sure that there is no existing translation, hence we could
avoid doing tlbie.

We could possibly race with a parallel fault filling the TLB. But
that should be ok because updatepp is only ever relaxing permissions.
We also look at linux pte permission bits when filling hash pte
permission bits. We also hold the linux pte busy bits while
inserting/updating a hashpte entry, hence a paralle update of
linux pte is not possible. On the other hand mprotect involves
ptep_modify_prot_start which cause a hpte invalidate and not updatepp.

Performance number:
We use randbox_access_bench written by Anton.

Kernel with THP disabled and smaller hash page table size.

    86.60%  random_access_b  [kernel.kallsyms]                [k] .native_hpte_updatepp
     2.10%  random_access_b  random_access_bench              [.] doit
     1.99%  random_access_b  [kernel.kallsyms]                [k] .do_raw_spin_lock
     1.85%  random_access_b  [kernel.kallsyms]                [k] .native_hpte_insert
     1.26%  random_access_b  [kernel.kallsyms]                [k] .native_flush_hash_range
     1.18%  random_access_b  [kernel.kallsyms]                [k] .__delay
     0.69%  random_access_b  [kernel.kallsyms]                [k] .native_hpte_remove
     0.37%  random_access_b  [kernel.kallsyms]                [k] .clear_user_page
     0.34%  random_access_b  [kernel.kallsyms]                [k] .__hash_page_64K
     0.32%  random_access_b  [kernel.kallsyms]                [k] fast_exception_return
     0.30%  random_access_b  [kernel.kallsyms]                [k] .hash_page_mm

With Fix:

    27.54%  random_access_b  random_access_bench              [.] doit
    22.90%  random_access_b  [kernel.kallsyms]                [k] .native_hpte_insert
     5.76%  random_access_b  [kernel.kallsyms]                [k] .native_hpte_remove
     5.20%  random_access_b  [kernel.kallsyms]                [k] fast_exception_return
     5.12%  random_access_b  [kernel.kallsyms]                [k] .__hash_page_64K
     4.80%  random_access_b  [kernel.kallsyms]                [k] .hash_page_mm
     3.31%  random_access_b  [kernel.kallsyms]                [k] data_access_common
     1.84%  random_access_b  [kernel.kallsyms]                [k] .trace_hardirqs_on_caller
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      aefa5688
  15. 02 12月, 2014 14 次提交
  17. 19 11月, 2014 2 次提交
    • M
      powerpc: Remove more traces of bootmem · e39f223f
      由 Michael Ellerman 提交于 
      Although we are now selecting NO_BOOTMEM, we still have some traces of
bootmem lying around. That is because even with NO_BOOTMEM there is
still a shim that converts bootmem calls into memblock calls, but
ultimately we want to remove all traces of bootmem.

Most of the patch is conversions from alloc_bootmem() to
memblock_virt_alloc(). In general a call such as:

  p = (struct foo *)alloc_bootmem(x);

Becomes:

  p = memblock_virt_alloc(x, 0);

We don't need the cast because memblock_virt_alloc() returns a void *.
The alignment value of zero tells memblock to use the default alignment,
which is SMP_CACHE_BYTES, the same value alloc_bootmem() uses.

We remove a number of NULL checks on the result of
memblock_virt_alloc(). That is because memblock_virt_alloc() will panic
if it can't allocate, in exactly the same way as alloc_bootmem(), so the
NULL checks are and always have been redundant.

The memory returned by memblock_virt_alloc() is already zeroed, so we
remove several memsets of the result of memblock_virt_alloc().

Finally we convert a few uses of __alloc_bootmem(x, y, MAX_DMA_ADDRESS)
to just plain memblock_virt_alloc(). We don't use memblock_alloc_base()
because MAX_DMA_ADDRESS is ~0ul on powerpc, so limiting the allocation
to that is pointless, 16XB ought to be enough for anyone.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      e39f223f
    • L
      powerpc/pseries: Initialise nvram_pstore_info's buf_lock · a49ab6ee
      由 Li Zhong 提交于 
      nvram_pstore_info's buf_lock is not initialized before registering,
which is clearly incorrect.

It causes some strange behavior when trying to obtain the lock during
kdump process.

On a UP configuration, the console stopped for a couple of seconds, then
"lockup suspected" warning printed out, but then it continued to run.

So try lock fails, and lockup reported, but then arch_spin_lock()
passes.
Signed-off-by: NLi Zhong <zhong@linux.vnet.ibm.com>
[mpe: Edited changelog]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      a49ab6ee
  19. 18 11月, 2014 4 次提交
    • M
      Merge remote-tracking branch 'scottwood/next' into next · 35891d40
      由 Michael Ellerman 提交于 
      Scott says:

"Highlights include a bunch of 8xx optimizations, device tree bindings
for Freescale BMan, QMan, and FMan datapath components, misc device tree
updates, and inbound rio window support."
      35891d40
    • M
      cxl: Name interrupts in /proc/interrupt · 80fa93fc
      由 Michael Neuling 提交于 
      Currently all interrupts generated by cxl are named "cxl".  This is not very
informative as we can't distinguish between cards, AFUs, error interrupts, user
contexts and user interrupts numbers.  Being able to distinguish them is useful
for setting affinity.

This patch gives each of these names in /proc/interrupts.

A two card CAPI system, with afu0.0 having 2 active contexts each with 4 user
IRQs each, will now look like this:

    % grep cxl /proc/interrupts
    444:          0  OPAL ICS 141312 Level     cxl-card1-err
    445:          0  OPAL ICS 141313 Level     cxl-afu1.0-err
    446:          0  OPAL ICS 141314 Level     cxl-afu1.0
    462:          0  OPAL ICS 2052 Level     cxl-afu0.0-pe0-1
    463:      75517  OPAL ICS 2053 Level     cxl-afu0.0-pe0-2
    468:          0  OPAL ICS 2054 Level     cxl-afu0.0-pe0-3
    469:          0  OPAL ICS 2055 Level     cxl-afu0.0-pe0-4
    470:          0  OPAL ICS 2056 Level     cxl-afu0.0-pe1-1
    471:      75506  OPAL ICS 2057 Level     cxl-afu0.0-pe1-2
    472:          0  OPAL ICS 2058 Level     cxl-afu0.0-pe1-3
    473:          0  OPAL ICS 2059 Level     cxl-afu0.0-pe1-4
    502:       1066  OPAL ICS 2050 Level     cxl-afu0.0
    514:          0  OPAL ICS 2048 Level     cxl-card0-err
    515:          0  OPAL ICS 2049 Level     cxl-afu0.0-err
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      80fa93fc
    • I
      cxl: Return error to PSL if IRQ demultiplexing fails & print clearer warning · bc78b05b
      由 Ian Munsie 提交于 
      If an AFU has a hardware bug that causes it to acknowledge a context
terminate or remove while that context has outstanding transactions, it
is possible for the kernel to receive an interrupt for that context
after we have removed it from the context list.

The kernel will not be able to demultiplex the interrupt (or worse - if
we have already reallocated the process handle we could mis-attribute it
to the new context), and printed a big scary warning.

It did not acknowledge the interrupt, which would effectively halt
further translation fault processing on the PSL.

This patch makes the warning clearer about the likely cause of the issue
(i.e. hardware bug) to make it obvious to future AFU designers of what
needs to be fixed. It also prints out the process handle which can then
be matched up with hardware and software traces for debugging.

It also acknowledges the interrupt to the PSL with either an address
error or acknowledge, so that the PSL can continue with other
translations.
Signed-off-by: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      bc78b05b
    • P
      powerpc/config: Enable memory driver · 76f3e292
      由 Prabhakar Kushwaha 提交于 
      As Freescale IFC controller has been moved to driver to driver/memory.

So enable memory driver in powerpc config
Signed-off-by: NPrabhakar Kushwaha <prabhakar@freescale.com>
Signed-off-by: NScott Wood <scottwood@freescale.com>
      76f3e292
  21. 17 11月, 2014 2 次提交
    • N
      rtc/tpo: Driver to support rtc and wakeup on PowerNV platform · 16b1d26e
      由 Neelesh Gupta 提交于 
      The patch implements the OPAL rtc driver that binds with the rtc
driver subsystem. The driver uses the platform device infrastructure
to probe the rtc device and register it to rtc class framework. The
'wakeup' is supported depending upon the property 'has-tpo' present
in the OF node. It provides a way to load the generic rtc driver in
in the absence of an OPAL driver.

The patch also moves the existing OPAL rtc get/set time interfaces to the
new driver and exposes the necessary OPAL calls using EXPORT_SYMBOL_GPL.

Test results:
-------------
Host:
[root@tul169p1 ~]# ls -l /sys/class/rtc/
total 0
lrwxrwxrwx 1 root root 0 Oct 14 03:07 rtc0 -> ../../devices/opal-rtc/rtc/rtc0
[root@tul169p1 ~]# cat /sys/devices/opal-rtc/rtc/rtc0/time
08:10:07
[root@tul169p1 ~]# echo `date '+%s' -d '+ 2 minutes'` > /sys/class/rtc/rtc0/wakealarm
[root@tul169p1 ~]# cat /sys/class/rtc/rtc0/wakealarm
1413274345
[root@tul169p1 ~]#

FSP:
$ smgr mfgState
standby
$ rtim timeofday

System time is valid: 2014/10/14 08:12:04.225115

$ smgr mfgState
ipling
$

CC: devicetree@vger.kernel.org
CC: tglx@linutronix.de
CC: rtc-linux@googlegroups.com
CC: a.zummo@towertech.it
Signed-off-by: NNeelesh Gupta <neelegup@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      16b1d26e
    • V
      powerpc: Use generic PIE randomization · 59994fb0
      由 Vineeth Vijayan 提交于 
      Back in 2009 we merged 501cb16d "Randomise PIEs", which added support for
randomizing PIE (Position Independent Executable) binaries.

That commit added randomize_et_dyn(), which correctly randomized the addresses,
but failed to honor PF_RANDOMIZE. That means it was not possible to disable PIE
randomization via the personality flag, or /proc/sys/kernel/randomize_va_space.

Since then there has been generic support for PIE randomization added to
binfmt_elf.c, selectable via ARCH_BINFMT_ELF_RANDOMIZE_PIE.

Enabling that allows us to drop randomize_et_dyn(), which means we start
honoring PF_RANDOMIZE correctly.

It also causes a fairly major change to how we layout PIE binaries.

Currently we will place the binary at 512MB-520MB for 32 bit binaries, or
512MB-1.5GB for 64 bit binaries, eg:

    $ cat /proc/$$/maps
    4e550000-4e580000 r-xp 00000000 08:02 129813       /bin/dash
    4e580000-4e590000 rw-p 00020000 08:02 129813       /bin/dash
    10014110000-10014140000 rw-p 00000000 00:00 0      [heap]
    3fffaa3f0000-3fffaa5a0000 r-xp 00000000 08:02 921  /lib/powerpc64le-linux-gnu/libc-2.19.so
    3fffaa5a0000-3fffaa5b0000 rw-p 001a0000 08:02 921  /lib/powerpc64le-linux-gnu/libc-2.19.so
    3fffaa5c0000-3fffaa5d0000 rw-p 00000000 00:00 0
    3fffaa5d0000-3fffaa5f0000 r-xp 00000000 00:00 0    [vdso]
    3fffaa5f0000-3fffaa620000 r-xp 00000000 08:02 1246 /lib/powerpc64le-linux-gnu/ld-2.19.so
    3fffaa620000-3fffaa630000 rw-p 00020000 08:02 1246 /lib/powerpc64le-linux-gnu/ld-2.19.so
    3ffffc340000-3ffffc370000 rw-p 00000000 00:00 0    [stack]

With this commit applied we don't do any special randomisation for the binary,
and instead rely on mmap randomisation. This means the binary ends up at high
addresses, eg:

    $ cat /proc/$$/maps
    3fff99820000-3fff999d0000 r-xp 00000000 08:02 921    /lib/powerpc64le-linux-gnu/libc-2.19.so
    3fff999d0000-3fff999e0000 rw-p 001a0000 08:02 921    /lib/powerpc64le-linux-gnu/libc-2.19.so
    3fff999f0000-3fff99a00000 rw-p 00000000 00:00 0
    3fff99a00000-3fff99a20000 r-xp 00000000 00:00 0      [vdso]
    3fff99a20000-3fff99a50000 r-xp 00000000 08:02 1246   /lib/powerpc64le-linux-gnu/ld-2.19.so
    3fff99a50000-3fff99a60000 rw-p 00020000 08:02 1246   /lib/powerpc64le-linux-gnu/ld-2.19.so
    3fff99a60000-3fff99a90000 r-xp 00000000 08:02 129813 /bin/dash
    3fff99a90000-3fff99aa0000 rw-p 00020000 08:02 129813 /bin/dash
    3fffc3de0000-3fffc3e10000 rw-p 00000000 00:00 0      [stack]
    3fffc55e0000-3fffc5610000 rw-p 00000000 00:00 0      [heap]

Although this should be OK, it's possible it might break badly written
binaries that make assumptions about the address space layout.
Signed-off-by: NVineeth Vijayan <vvijayan@mvista.com>
[mpe: Rewrite changelog]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      59994fb0