POWER5 added popcntb, and POWER7 added popcntw and popcntd. As a first step
this patch does all the work out of line, but it would be nice to implement
them as inlines with an out of line fallback.

The performance issue with hweight was noticed when disabling SMT on a large
(192 thread) POWER7 box. The patch improves that testcase by about 8%.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

commit 534af108(kgdb,kdb: individual
register set and and get API) introduce dbg_get_reg/dbg_set_reg API
for individual register get and set.

This patch implement those APIs for ppc.
Signed-off-by: NDongdong Deng <dongdong.deng@windriver.com>
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>

The taskstats interface uses microsecond granularity for the user and
system time values.  The conversion from cputime to the taskstats values
uses the cputime_to_msecs primitive which effectively limits the
granularity to milliseconds.  Add the cputime_to_usecs primitive for
architectures that have better, more precise CPU time values.  Remove
cputime_to_msecs primitive because there are no more users left.
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: NBalbir Singh <balbir@linux.vnet.ibm.com>
Cc: Luck Tony <tony.luck@intel.com>
Cc: Shailabh Nagar <nagar1234@in.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Shailabh Nagar <nagar@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since we no longer need to provide KM_type, the whole pte_*map_nested()
API is now redundant, remove it.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NChris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Miller <davem@davemloft.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Keep the current interface but ignore the KM_type and use a stack based
approach.

The advantage is that we get rid of crappy code like:

	#define __KM_PTE			\
		(in_nmi() ? KM_NMI_PTE : 	\
		 in_irq() ? KM_IRQ_PTE :	\
		 KM_PTE0)

and in general can stop worrying about what context we're in and what kmap
slots might be appropriate for that.

The downside is that FRV kmap_atomic() gets more expensive.

For now we use a CPP trick suggested by Andrew:

  #define kmap_atomic(page, args...) __kmap_atomic(page)

to avoid having to touch all kmap_atomic() users in a single patch.

[ not compiled on:
  - mn10300: the arch doesn't actually build with highmem to begin with ]

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix up drivers/gpu/drm/i915/intel_overlay.c]
Acked-by: NRik van Riel <riel@redhat.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NChris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Miller <davem@davemloft.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When system uses 36bit physical address, res.start is 36bit
physical address. But the function of in_be32 returns 32bit
physical address. Then both of them compared each other is
wrong. So by converting the address of res.start into
the right format fixes this issue.
Signed-off-by: NLan Chunhe-B25806 <b25806@freescale.com>
Signed-off-by: NRoy Zang <tie-fei.zang@freescale.com>
Reviewed-by: NAnton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Move Freescale elbc interrupt from nand driver to elbc driver.
Then all elbc devices can use the interrupt instead of ONLY nand.

For former nand driver, it had the two functions:

1. detecting nand flash partitions;
2. registering elbc interrupt.

Now, second function is removed to fsl_lbc.c.
Signed-off-by: NLan Chunhe-B25806 <b25806@freescale.com>
Signed-off-by: NRoy Zang <tie-fei.zang@freescale.com>
Reviewed-by: NAnton Vorontsov <cbouatmailru@gmail.com>
Cc: Wood Scott-B07421 <B07421@freescale.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

We have to protect the include for linux/of.h by __KERNEL__ so it doesn't
accidently get referenced outside.

This patch fixes this and makes the tree compile again.
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAlexander Graf <agraf@suse.de>

The current interrupt logic is just completely broken. We get a notification
from user space, telling us that an interrupt is there. But then user space
expects us that we just acknowledge an interrupt once we deliver it to the
guest.

This is not how real hardware works though. On real hardware, the interrupt
controller pulls the external interrupt line until it gets notified that the
interrupt was received.

So in reality we have two events: pulling and letting go of the interrupt line.

To maintain backwards compatibility, I added a new request for the pulling
part. The letting go part was implemented earlier already.

With this in place, we can now finally start guests that do not randomly stall
and stop to work at random times.

This patch implements above logic for Book3S.
Signed-off-by: NAlexander Graf <agraf@suse.de>

Up until now we were doing segment mappings wrong on Book3s_32. For Book3s_64
we were using a trick where we know that a single mmu_context gives us 16 bits
of context ids.

The mm system on Book3s_32 instead uses a clever algorithm to distribute VSIDs
across the available range, so a context id really only gives us 16 available
VSIDs.

To keep at least a few guest processes in the SID shadow, let's map a number of
contexts that we can use as VSID pool. This makes the code be actually correct
and shouldn't hurt performance too much.
Signed-off-by: NAlexander Graf <agraf@suse.de>

Now that the actual mtsr doesn't do anything anymore, we can move the sr
contents over to the shared page, so a guest can directly read and write
its sr contents from guest context.
Signed-off-by: NAlexander Graf <agraf@suse.de>

Right now we're examining the contents of Book3s_32's segment registers when
the register is written and put the interpreted contents into a struct.

There are two reasons this is bad. For starters, the struct has worse real-time
performance, as it occupies more ram. But the more important part is that with
segment registers being interpreted from their raw values, we can put them in
the shared page, allowing guests to mess with them directly.

This patch makes the internal representation of SRs be u32s.
Signed-off-by: NAlexander Graf <agraf@suse.de>

We will soon add SR PV support to the shared page, so we need some
infrastructure that allows the guest to query for features KVM exports.

This patch adds a second return value to the magic mapping that
indicated to the guest which features are available.
Signed-off-by: NAlexander Graf <agraf@suse.de>

On Book3S KVM we directly expose some asm pointers to C code as
variables. These need to be relocated and thus break on relocatable
kernels.

To make sure we can at least build, let's mark them as long instead
of u32 where 64bit relocations don't work.

This fixes the following build error:

WARNING: 2 bad relocations^M
> c000000000008590 R_PPC64_ADDR32    .text+0x4000000000008460^M
> c000000000008594 R_PPC64_ADDR32    .text+0x4000000000008598^M

Please keep in mind that actually using KVM on a relocated kernel
might still break. This only fixes the compile problem.
Reported-by: NSubrata Modak <subrata@linux.vnet.ibm.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

On Book3s_32 the tlbie instruction flushed effective addresses by the mask
0x0ffff000. This is pretty hard to reflect with a hash that hashes ~0xfff, so
to speed up that target we should also keep a special hash around for it.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

So far we've been running all code without locking of any sort. This wasn't
really an issue because I didn't see any parallel access to the shadow MMU
code coming.

But then I started to implement dirty bitmapping to MOL which has the video
code in its own thread, so suddenly we had the dirty bitmap code run in
parallel to the shadow mmu code. And with that came trouble.

So I went ahead and made the MMU modifying functions as parallelizable as
I could think of. I hope I didn't screw up too much RCU logic :-). If you
know your way around RCU and locking and what needs to be done when, please
take a look at this patch.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Now that we have the shared page in place and the MMU code knows about
the magic page, we can expose that capability to the guest!
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

We need to override EA as well as PA lookups for the magic page. When the guest
tells us to project it, the magic page overrides any guest mappings.

In order to reflect that, we need to hook into all the MMU layers of KVM to
force map the magic page if necessary.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

We will be introducing a method to project the shared page in guest context.
As soon as we're talking about this coupling, the shared page is colled magic
page.

This patch introduces simple defines, so the follow-up patches are easier to
read.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

On PowerPC it's very normal to not support all of the physical RAM in real mode.
To check if we're matching on the shared page or not, we need to know the limits
so we can restrain ourselves to that range.

So let's make it a define instead of open-coding it. And while at it, let's also
increase it.
Signed-off-by: NAlexander Graf <agraf@suse.de>

v2 -> v3:

  - RMO -> PAM (non-magic page)
Signed-off-by: NAvi Kivity <avi@redhat.com>

When the guest turns on interrupts again, it needs to know if we have an
interrupt pending for it. Because if so, it should rather get out of guest
context and get the interrupt.

So we introduce a new field in the shared page that we use to tell the guest
that there's a pending interrupt lying around.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

While running in hooked code we need to store register contents out because
we must not clobber any registers.

So let's add some fields to the shared page we can just happily write to.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

When running in hooked code we need a way to disable interrupts without
clobbering any interrupts or exiting out to the hypervisor.

To achieve this, we have an additional critical field in the shared page. If
that field is equal to the r1 register of the guest, it tells the hypervisor
that we're in such a critical section and thus may not receive any interrupts.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

To communicate with KVM directly we need to plumb some sort of interface
between the guest and KVM. Usually those interfaces use hypercalls.

This hypercall implementation is described in the last patch of the series
in a special documentation file. Please read that for further information.

This patch implements stubs to handle KVM PPC hypercalls on the host and
guest side alike.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

When in kernel mode there are 4 additional registers available that are
simple data storage. Instead of exiting to the hypervisor to read and
write those, we can just share them with the guest using the page.

This patch converts all users of the current field to the shared page.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The SRR0 and SRR1 registers contain cached values of the PC and MSR
respectively. They get written to by the hypervisor when an interrupt
occurs or directly by the kernel. They are also used to tell the rfi(d)
instruction where to jump to.

Because it only gets touched on defined events that, it's very simple to
share with the guest. Hypervisor and guest both have full r/w access.

This patch converts all users of the current field to the shared page.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The DAR register contains the address a data page fault occured at. This
register behaves pretty much like a simple data storage register that gets
written to on data faults. There is no hypervisor interaction required on
read or write.

This patch converts all users of the current field to the shared page.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The DSISR register contains information about a data page fault. It is fully
read/write from inside the guest context and we don't need to worry about
interacting based on writes of this register.

This patch converts all users of the current field to the shared page.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

One of the most obvious registers to share with the guest directly is the
MSR. The MSR contains the "interrupts enabled" flag which the guest has to
toggle in critical sections.

So in order to bring the overhead of interrupt en- and disabling down, let's
put msr into the shared page. Keep in mind that even though you can fully read
its contents, writing to it doesn't always update all state. There are a few
safe fields that don't require hypervisor interaction. See the documentation
for a list of MSR bits that are safe to be set from inside the guest.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

For transparent variable sharing between the hypervisor and guest, I introduce
a shared page. This shared page will contain all the registers the guest can
read and write safely without exiting guest context.

This patch only implements the stubs required for the basic structure of the
shared page. The actual register moving follows.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Just a minor cleanup patch that makes things easier to the following patches.
No functionality change in this patch.
Signed-off-by: NVenkatesh Pallipadi <venki@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1286237003-12406-3-git-send-email-venki@google.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Provide a mechanism that allows running code in IRQ context. It is
most useful for NMI code that needs to interact with the rest of the
system -- like wakeup a task to drain buffers.

Perf currently has such a mechanism, so extract that and provide it as
a generic feature, independent of perf so that others may also
benefit.

The IRQ context callback is generated through self-IPIs where
possible, or on architectures like powerpc the decrementer (the
built-in timer facility) is set to generate an interrupt immediately.

Architectures that don't have anything like this get to do with a
callback from the timer tick. These architectures can call
irq_work_run() at the tail of any IRQ handlers that might enqueue such
work (like the perf IRQ handler) to avoid undue latencies in
processing the work.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NKyle McMartin <kyle@mcmartin.ca>
Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
[ various fixes ]
Signed-off-by: NHuang Ying <ying.huang@intel.com>
LKML-Reference: <1287036094.7768.291.camel@yhuang-dev>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The patch below updates broken web addresses in the arch directory.
Signed-off-by: NJustin P. Mattock <justinmattock@gmail.com>
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Finn Thain <fthain@telegraphics.com.au>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Reviewed-by: NFinn Thain <fthain@telegraphics.com.au>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Update setup_page_sizes() to support for a MMU v1.0 FSL style MMU
implementation.  In such a processor, we don't have TLB0PS or EPTCFG
registers (and access to these registers may cause exceptions).  We need
to parse the older format of TLBnCFG for page size support.  Additionaly,
assume since we are an FSL implementation that we have 2 TLB arrays and
the second array contains the variable size pages.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

It adds cache-sram support in P1/P2 QorIQ platforms as under:

* A small abstraction over powerpc's remote heap allocator
* Exports mpc85xx_cache_sram_alloc()/free() APIs
* Supports only one contiguous SRAM window
* Drivers can do the following in Kconfig to use these APIs
    "select FSL_85XX_CACHE_SRAM if MPC85xx"
* Required SRAM size and the offset where SRAM should be mapped must be
  provided at kernel command line as :
    cache-sram-size=<value>
    cache-sram-offset=<offset>
Signed-off-by: NHarninder Rai <harninder.rai@freescale.com>
Signed-off-by: NVivek Mahajan <vivek.mahajan@freescale.com>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

There exists a four line chunk of code, which when configured for
64 bit address space, can incorrectly set certain page flags during
the TLB creation.  It turns out that this is code which isn't used,
but might still serve a purpose.  Since it isn't obvious why it exists
or why it causes problems, the below description covers both in detail.

For powerpc bootstrap, the physical memory (at most 768M), is mapped
into the kernel space via the following path:

MMU_init()
    |
    + adjust_total_lowmem()
            |
            + map_mem_in_cams()
                    |
                    + settlbcam(i, virt, phys, cam_sz, PAGE_KERNEL_X, 0);

On settlbcam(), the kernel will create TLB entries according to the flag,
PAGE_KERNEL_X.

settlbcam()
{
        ...
        TLBCAM[index].MAS1 = MAS1_VALID
                        | MAS1_IPROT | MAS1_TSIZE(tsize) | MAS1_TID(pid);
                                ^
			These entries cannot be invalidated by the
			kernel since MAS1_IPROT is set on TLB property.
        ...
        if (flags & _PAGE_USER) {
           TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
           TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
        }

For classic BookE (flags & _PAGE_USER) is 'zero' so it's fine.
But on boards like the the Freescale P4080, we want to support 36-bit
physical address on it. So the following options may be set:

CONFIG_FSL_BOOKE=y
CONFIG_PTE_64BIT=y
CONFIG_PHYS_64BIT=y

As a result, boards like the P4080 will introduce PTE format as Book3E.
As per the file: arch/powerpc/include/asm/pgtable-ppc32.h

  * #elif defined(CONFIG_FSL_BOOKE) && defined(CONFIG_PTE_64BIT)
  * #include <asm/pte-book3e.h>

So PAGE_KERNEL_X is __pgprot(_PAGE_BASE | _PAGE_KERNEL_RWX) and the
book3E version of _PAGE_KERNEL_RWX is defined with:

  (_PAGE_BAP_SW | _PAGE_BAP_SR | _PAGE_DIRTY | _PAGE_BAP_SX)

Note the _PAGE_BAP_SR, which is also defined in the book3E _PAGE_USER:

  #define _PAGE_USER        (_PAGE_BAP_UR | _PAGE_BAP_SR) /* Can be read */

So the possibility exists to wrongly assign the user MAS3_U<RWX> bits
to kernel (PAGE_KERNEL_X) address space via the following code fragment:

        if (flags & _PAGE_USER) {
           TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
           TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
        }

Here is a dump of the TLB info from Simics with the above code present:
------
L2 TLB1
                                            GT                   SSS UUU V I
 Row  Logical           Physical            SS TLPID  TID  WIMGE XWR XWR F P   V
----- ----------------- ------------------- -- ----- ----- ----- --- --- - -   -
  0   c0000000-cfffffff 000000000-00fffffff 00     0     0   M   XWR XWR 0 1   1
  1   d0000000-dfffffff 010000000-01fffffff 00     0     0   M   XWR XWR 0 1   1
  2   e0000000-efffffff 020000000-02fffffff 00     0     0   M   XWR XWR 0 1   1

Actually this conditional code was used for two legacy functions:

  1: support KGDB to set break point.
     KGDB already dropped this; now uses its core write to set break point.

  2: io_block_mapping() to create TLB in segmentation size (not PAGE_SIZE)
     for device IO space.
     This use case is also removed from the latest PowerPC kernel.

However, there may still be a use case for it in the future, like
large user pages, so we can't remove it entirely.  As an alternative,
we match on all bits of _PAGE_USER instead of just any bits, so the
case where just _PAGE_BAP_SR is set can't sneak through.

With this done, the TLB appears without U having XWR as below:

-------
L2 TLB1
                                            GT                   SSS UUU V I
 Row  Logical           Physical            SS TLPID  TID  WIMGE XWR XWR F P   V
----- ----------------- ------------------- -- ----- ----- ----- --- --- - -   -
  0   c0000000-cfffffff 000000000-00fffffff 00     0     0   M   XWR     0 1   1
  1   d0000000-dfffffff 010000000-01fffffff 00     0     0   M   XWR     0 1   1
  2   e0000000-efffffff 020000000-02fffffff 00     0     0   M   XWR     0 1   1
Signed-off-by: NTiejun Chen <tiejun.chen@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

Right now just the kexec crash pathway turns turns off the interrupts.
Pull that out and make a generic version for use elsewhere
Signed-off-by: NMatthew McClintock <msm@freescale.com>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

BUID_HI and BUID_LO are used to pass data to call_rtas, which expects
ints or u32s. But the macro doesn't cast the return, so the result is
still u64. Use the upper_32_bits and lower_32_bits macros that have been
added to kernel.h.

Found by getting printf format errors trying to debug print the args, no
actual code change for 64 bit kernels where the macros are actually
used.
Signed-off-by: NMilton Miller <miltonm@bga.com>
Signed-off-by: NNishanth Aravamudan <nacc@us.ibm.com>
Acked-by: NLinas Vepstas <linasvepstas@gmail.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Export the rtas_ibm_suspend_me() routine.  This is needed to perform
partition migration in the kernel.
Signed-off-by: NNathan Fontenot <nfont@austin.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Now that the generic DMAEngine API has support for scatterlist to
scatterlist copying, the device_prep_slave_sg() portion of the
DMA_SLAVE API is no longer necessary and has been removed.

However, the device_control() portion of the DMA_SLAVE API is still
useful to control device specific parameters, such as externally
controlled DMA transfers and maximum burst length.

A special dma_ctrl_cmd has been added to enable externally controlled
DMA transfers. This is currently specific to the Freescale DMA
controller, but can easily be made generic when another user is found.
Signed-off-by: NIra W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>