Tasks without a user-defined clamp value are considered not clamped
and by default their utilization can have any value in the
[0..SCHED_CAPACITY_SCALE] range.

Tasks with a user-defined clamp value are allowed to request any value
in that range, and the required clamp is unconditionally enforced.
However, a "System Management Software" could be interested in limiting
the range of clamp values allowed for all tasks.

Add a privileged interface to define a system default configuration via:

  /proc/sys/kernel/sched_uclamp_util_{min,max}

which works as an unconditional clamp range restriction for all tasks.

With the default configuration, the full SCHED_CAPACITY_SCALE range of
values is allowed for each clamp index. Otherwise, the task-specific
clamp is capped by the corresponding system default value.

Do that by tracking, for each task, the "effective" clamp value and
bucket the task has been refcounted in at enqueue time. This
allows to lazy aggregate "requested" and "system default" values at
enqueue time and simplifies refcounting updates at dequeue time.

The cached bucket ids are used to avoid (relatively) more expensive
integer divisions every time a task is enqueued.

An active flag is used to report when the "effective" value is valid and
thus the task is actually refcounted in the corresponding rq's bucket.
Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alessio Balsini <balsini@android.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Perret <quentin.perret@arm.com>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Steve Muckle <smuckle@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Todd Kjos <tkjos@google.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lkml.kernel.org/r/20190621084217.8167-5-patrick.bellasi@arm.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

When a task sleeps it removes its max utilization clamp from its CPU.
However, the blocked utilization on that CPU can be higher than the max
clamp value enforced while the task was running. This allows undesired
CPU frequency increases while a CPU is idle, for example, when another
CPU on the same frequency domain triggers a frequency update, since
schedutil can now see the full not clamped blocked utilization of the
idle CPU.

Fix this by using:

  uclamp_rq_dec_id(p, rq, UCLAMP_MAX)
    uclamp_rq_max_value(rq, UCLAMP_MAX, clamp_value)

to detect when a CPU has no more RUNNABLE clamped tasks and to flag this
condition.

Don't track any minimum utilization clamps since an idle CPU never
requires a minimum frequency. The decay of the blocked utilization is
good enough to reduce the CPU frequency.
Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alessio Balsini <balsini@android.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Perret <quentin.perret@arm.com>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Steve Muckle <smuckle@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Todd Kjos <tkjos@google.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lkml.kernel.org/r/20190621084217.8167-4-patrick.bellasi@arm.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Because of bucketization, different task-specific clamp values are
tracked in the same bucket.  For example, with 20% bucket size and
assuming to have:

  Task1: util_min=25%
  Task2: util_min=35%

both tasks will be refcounted in the [20..39]% bucket and always boosted
only up to 20% thus implementing a simple floor aggregation normally
used in histograms.

In systems with only few and well-defined clamp values, it would be
useful to track the exact clamp value required by a task whenever
possible. For example, if a system requires only 23% and 47% boost
values then it's possible to track the exact boost required by each
task using only 3 buckets of ~33% size each.

Introduce a mechanism to max aggregate the requested clamp values of
RUNNABLE tasks in the same bucket. Keep it simple by resetting the
bucket value to its base value only when a bucket becomes inactive.
Allow a limited and controlled overboosting margin for tasks recounted
in the same bucket.

In systems where the boost values are not known in advance, it is still
possible to control the maximum acceptable overboosting margin by tuning
the number of clamp groups. For example, 20 groups ensure a 5% maximum
overboost.

Remove the rq bucket initialization code since a correct bucket value
is now computed when a task is refcounted into a CPU's rq.
Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alessio Balsini <balsini@android.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Perret <quentin.perret@arm.com>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Steve Muckle <smuckle@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Todd Kjos <tkjos@google.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lkml.kernel.org/r/20190621084217.8167-3-patrick.bellasi@arm.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Utilization clamping allows to clamp the CPU's utilization within a
[util_min, util_max] range, depending on the set of RUNNABLE tasks on
that CPU. Each task references two "clamp buckets" defining its minimum
and maximum (util_{min,max}) utilization "clamp values". A CPU's clamp
bucket is active if there is at least one RUNNABLE tasks enqueued on
that CPU and refcounting that bucket.

When a task is {en,de}queued {on,from} a rq, the set of active clamp
buckets on that CPU can change. If the set of active clamp buckets
changes for a CPU a new "aggregated" clamp value is computed for that
CPU. This is because each clamp bucket enforces a different utilization
clamp value.

Clamp values are always MAX aggregated for both util_min and util_max.
This ensures that no task can affect the performance of other
co-scheduled tasks which are more boosted (i.e. with higher util_min
clamp) or less capped (i.e. with higher util_max clamp).

A task has:
   task_struct::uclamp[clamp_id]::bucket_id
to track the "bucket index" of the CPU's clamp bucket it refcounts while
enqueued, for each clamp index (clamp_id).

A runqueue has:
   rq::uclamp[clamp_id]::bucket[bucket_id].tasks
to track how many RUNNABLE tasks on that CPU refcount each
clamp bucket (bucket_id) of a clamp index (clamp_id).
It also has a:
   rq::uclamp[clamp_id]::bucket[bucket_id].value
to track the clamp value of each clamp bucket (bucket_id) of a clamp
index (clamp_id).

The rq::uclamp::bucket[clamp_id][] array is scanned every time it's
needed to find a new MAX aggregated clamp value for a clamp_id. This
operation is required only when it's dequeued the last task of a clamp
bucket tracking the current MAX aggregated clamp value. In this case,
the CPU is either entering IDLE or going to schedule a less boosted or
more clamped task.
The expected number of different clamp values configured at build time
is small enough to fit the full unordered array into a single cache
line, for configurations of up to 7 buckets.

Add to struct rq the basic data structures required to refcount the
number of RUNNABLE tasks for each clamp bucket. Add also the max
aggregation required to update the rq's clamp value at each
enqueue/dequeue event.

Use a simple linear mapping of clamp values into clamp buckets.
Pre-compute and cache bucket_id to avoid integer divisions at
enqueue/dequeue time.
Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alessio Balsini <balsini@android.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Perret <quentin.perret@arm.com>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Steve Muckle <smuckle@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Todd Kjos <tkjos@google.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lkml.kernel.org/r/20190621084217.8167-2-patrick.bellasi@arm.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

The term 'weighted' is not needed since there is no 'unweighted' load.
Instead use the term 'runnable' to distinguish 'runnable' load
(avg.runnable_load_avg) used in load balance from load (avg.load_avg)
which is the sum of 'runnable' and 'blocked' load.
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Patrick Bellasi <patrick.bellasi@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Perret <quentin.perret@arm.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/57f27a7f-2775-d832-e965-0f4d51bb1954@arm.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

So that external modules can hook into them and extract the info they
need. Since these new tracepoints have no events associated with them
exporting these tracepoints make them useful for external modules to
perform testing and debugging. There's no other way otherwise to access
them.

BPF doesn't have infrastructure to access these bare tracepoints either.
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pavankumar Kondeti <pkondeti@codeaurora.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Perret <quentin.perret@arm.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Uwe Kleine-Konig <u.kleine-koenig@pengutronix.de>
Link: https://lkml.kernel.org/r/20190604111459.2862-7-qais.yousef@arm.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

The new tracepoint allows us to track the changes in overutilized
status.

Overutilized status is associated with EAS. It indicates that the system
is in high performance state. EAS is disabled when the system is in this
state since there's not much energy savings while high performance tasks
are pushing the system to the limit and it's better to default to the
spreading behavior of the scheduler.

This tracepoint helps understanding and debugging the conditions under
which this happens.
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pavankumar Kondeti <pkondeti@codeaurora.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Perret <quentin.perret@arm.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Uwe Kleine-Konig <u.kleine-koenig@pengutronix.de>
Link: https://lkml.kernel.org/r/20190604111459.2862-6-qais.yousef@arm.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

The new tracepoint allows tracking PELT signals at sched_entity level.
Which is supported in CFS tasks and taskgroups only.
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pavankumar Kondeti <pkondeti@codeaurora.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Perret <quentin.perret@arm.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Uwe Kleine-Konig <u.kleine-koenig@pengutronix.de>
Link: https://lkml.kernel.org/r/20190604111459.2862-5-qais.yousef@arm.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

The new tracepoints allow tracking PELT signals at rq level for all
scheduling classes + irq.
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pavankumar Kondeti <pkondeti@codeaurora.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Perret <quentin.perret@arm.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Uwe Kleine-Konig <u.kleine-koenig@pengutronix.de>
Link: https://lkml.kernel.org/r/20190604111459.2862-4-qais.yousef@arm.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

The new functions allow modules to access internal data structures of
unexported struct cfs_rq and struct rq to extract important information
from the tracepoints to be introduced in later patches.

While at it fix alphabetical order of struct declarations in sched.h
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pavankumar Kondeti <pkondeti@codeaurora.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Perret <quentin.perret@arm.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Uwe Kleine-Konig <u.kleine-koenig@pengutronix.de>
Link: https://lkml.kernel.org/r/20190604111459.2862-3-qais.yousef@arm.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Remove the #ifdef CONFIG_SCHED_DEBUG.

Some of the tracepoints to be introduced in later patches need to access
this function. Hence make it always available since the tracepoints are
not protected by CONFIG_SCHED_DEBUG.
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pavankumar Kondeti <pkondeti@codeaurora.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Perret <quentin.perret@arm.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Uwe Kleine-Konig <u.kleine-koenig@pengutronix.de>
Link: https://lkml.kernel.org/r/20190604111459.2862-2-qais.yousef@arm.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Statements in the loop's body and before it are identical.
Use do-while to not repeat it.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/43ffea6ee2152b90dedf962eac851609e4197218.1560256112.git.asml.silence@gmail.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

The 'struct sched_domain *sd' parameter to arch_scale_cpu_capacity() is
unused since commit:

  765d0af1 ("sched/topology: Remove the ::smt_gain field from 'struct sched_domain'")

Remove it.
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: gregkh@linuxfoundation.org
Cc: linux@armlinux.org.uk
Cc: quentin.perret@arm.com
Cc: rafael@kernel.org
Link: https://lkml.kernel.org/r/1560783617-5827-1-git-send-email-vincent.guittot@linaro.orgSigned-off-by: Ingo Molnar <mingo@kernel.org>

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Pull iommu fix from Joerg Roedel:
 "Revert a commit from the previous pile of fixes which causes new
  lockdep splats. It is better to revert it for now and work on a better
  and more well tested fix"

* tag 'iommu-fix-v5.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  Revert "iommu/vt-d: Fix lock inversion between iommu->lock and device_domain_lock"

This reverts commit 7560cc3c.

With 5.2.0-rc5 I can easily trigger this with lockdep and iommu=pt:

    ======================================================
    WARNING: possible circular locking dependency detected
    5.2.0-rc5 #78 Not tainted
    ------------------------------------------------------
    swapper/0/1 is trying to acquire lock:
    00000000ea2b3beb (&(&iommu->lock)->rlock){+.+.}, at: domain_context_mapping_one+0xa5/0x4e0
    but task is already holding lock:
    00000000a681907b (device_domain_lock){....}, at: domain_context_mapping_one+0x8d/0x4e0
    which lock already depends on the new lock.
    the existing dependency chain (in reverse order) is:
    -> #1 (device_domain_lock){....}:
           _raw_spin_lock_irqsave+0x3c/0x50
           dmar_insert_one_dev_info+0xbb/0x510
           domain_add_dev_info+0x50/0x90
           dev_prepare_static_identity_mapping+0x30/0x68
           intel_iommu_init+0xddd/0x1422
           pci_iommu_init+0x16/0x3f
           do_one_initcall+0x5d/0x2b4
           kernel_init_freeable+0x218/0x2c1
           kernel_init+0xa/0x100
           ret_from_fork+0x3a/0x50
    -> #0 (&(&iommu->lock)->rlock){+.+.}:
           lock_acquire+0x9e/0x170
           _raw_spin_lock+0x25/0x30
           domain_context_mapping_one+0xa5/0x4e0
           pci_for_each_dma_alias+0x30/0x140
           dmar_insert_one_dev_info+0x3b2/0x510
           domain_add_dev_info+0x50/0x90
           dev_prepare_static_identity_mapping+0x30/0x68
           intel_iommu_init+0xddd/0x1422
           pci_iommu_init+0x16/0x3f
           do_one_initcall+0x5d/0x2b4
           kernel_init_freeable+0x218/0x2c1
           kernel_init+0xa/0x100
           ret_from_fork+0x3a/0x50

    other info that might help us debug this:
     Possible unsafe locking scenario:
           CPU0                    CPU1
           ----                    ----
      lock(device_domain_lock);
                                   lock(&(&iommu->lock)->rlock);
                                   lock(device_domain_lock);
      lock(&(&iommu->lock)->rlock);

     *** DEADLOCK ***
    2 locks held by swapper/0/1:
     #0: 00000000033eb13d (dmar_global_lock){++++}, at: intel_iommu_init+0x1e0/0x1422
     #1: 00000000a681907b (device_domain_lock){....}, at: domain_context_mapping_one+0x8d/0x4e0

    stack backtrace:
    CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.2.0-rc5 #78
    Hardware name: LENOVO 20KGS35G01/20KGS35G01, BIOS N23ET50W (1.25 ) 06/25/2018
    Call Trace:
     dump_stack+0x85/0xc0
     print_circular_bug.cold.57+0x15c/0x195
     __lock_acquire+0x152a/0x1710
     lock_acquire+0x9e/0x170
     ? domain_context_mapping_one+0xa5/0x4e0
     _raw_spin_lock+0x25/0x30
     ? domain_context_mapping_one+0xa5/0x4e0
     domain_context_mapping_one+0xa5/0x4e0
     ? domain_context_mapping_one+0x4e0/0x4e0
     pci_for_each_dma_alias+0x30/0x140
     dmar_insert_one_dev_info+0x3b2/0x510
     domain_add_dev_info+0x50/0x90
     dev_prepare_static_identity_mapping+0x30/0x68
     intel_iommu_init+0xddd/0x1422
     ? printk+0x58/0x6f
     ? lockdep_hardirqs_on+0xf0/0x180
     ? do_early_param+0x8e/0x8e
     ? e820__memblock_setup+0x63/0x63
     pci_iommu_init+0x16/0x3f
     do_one_initcall+0x5d/0x2b4
     ? do_early_param+0x8e/0x8e
     ? rcu_read_lock_sched_held+0x55/0x60
     ? do_early_param+0x8e/0x8e
     kernel_init_freeable+0x218/0x2c1
     ? rest_init+0x230/0x230
     kernel_init+0xa/0x100
     ret_from_fork+0x3a/0x50

domain_context_mapping_one() is taking device_domain_lock first then
iommu lock, while dmar_insert_one_dev_info() is doing the reverse.

That should be introduced by commit:

7560cc3c ("iommu/vt-d: Fix lock inversion between iommu->lock and
              device_domain_lock", 2019-05-27)

So far I still cannot figure out how the previous deadlock was
triggered (I cannot find iommu lock taken before calling of
iommu_flush_dev_iotlb()), however I'm pretty sure that that change
should be incomplete at least because it does not fix all the places
so we're still taking the locks in different orders, while reverting
that commit is very clean to me so far that we should always take
device_domain_lock first then the iommu lock.

We can continue to try to find the real culprit mentioned in
7560cc3c, but for now I think we should revert it to fix current
breakage.

CC: Joerg Roedel <joro@8bytes.org>
CC: Lu Baolu <baolu.lu@linux.intel.com>
CC: dave.jiang@intel.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Tested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

Pull PCI fix from Bjorn Helgaas:
 "If an IOMMU is present, ignore the P2PDMA whitelist we added for v5.2
  because we don't yet know how to support P2PDMA in that case (Logan
  Gunthorpe)"

* tag 'pci-v5.2-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI/P2PDMA: Ignore root complex whitelist when an IOMMU is present

Pull SCSI fixes from James Bottomley:
 "Three driver fixes (and one version number update): a suspend hang in
  ufs, a qla hard lock on module removal and a qedi panic during
  discovery"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: qla2xxx: Fix hardlockup in abort command during driver remove
  scsi: ufs: Avoid runtime suspend possibly being blocked forever
  scsi: qedi: update driver version to 8.37.0.20
  scsi: qedi: Check targetname while finding boot target information

Pull powerpc fixes from Michael Ellerman:
 "This is a frustratingly large batch at rc5. Some of these were sent
  earlier but were missed by me due to being distracted by other things,
  and some took a while to track down due to needing manual bisection on
  old hardware. But still we clearly need to improve our testing of KVM,
  and of 32-bit, so that we catch these earlier.

  Summary: seven fixes, all for bugs introduced this cycle.

   - The commit to add KASAN support broke booting on 32-bit SMP
     machines, due to a refactoring that moved some setup out of the
     secondary CPU path.

   - A fix for another 32-bit SMP bug introduced by the fast syscall
     entry implementation for 32-bit BOOKE. And a build fix for the same
     commit.

   - Our change to allow the DAWR to be force enabled on Power9
     introduced a bug in KVM, where we clobber r3 leading to a host
     crash.

   - The same commit also exposed a previously unreachable bug in the
     nested KVM handling of DAWR, which could lead to an oops in a
     nested host.

   - One of the DMA reworks broke the b43legacy WiFi driver on some
     people's powermacs, fix it by enabling a 30-bit ZONE_DMA on 32-bit.

   - A fix for TLB flushing in KVM introduced a new bug, as it neglected
     to also flush the ERAT, this could lead to memory corruption in the
     guest.

  Thanks to: Aaro Koskinen, Christoph Hellwig, Christophe Leroy, Larry
  Finger, Michael Neuling, Suraj Jitindar Singh"

* tag 'powerpc-5.2-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  KVM: PPC: Book3S HV: Invalidate ERAT when flushing guest TLB entries
  powerpc: enable a 30-bit ZONE_DMA for 32-bit pmac
  KVM: PPC: Book3S HV: Only write DAWR[X] when handling h_set_dawr in real mode
  KVM: PPC: Book3S HV: Fix r3 corruption in h_set_dabr()
  powerpc/32: fix build failure on book3e with KVM
  powerpc/booke: fix fast syscall entry on SMP
  powerpc/32s: fix initial setup of segment registers on secondary CPU

When trying to align the minimum encryption key size requirement for
Bluetooth connections, it turns out doing this in a central location in
the HCI connection handling code is not possible.

Original Bluetooth version up to 2.0 used a security model where the
L2CAP service would enforce authentication and encryption.  Starting
with Bluetooth 2.1 and Secure Simple Pairing that model has changed into
that the connection initiator is responsible for providing an encrypted
ACL link before any L2CAP communication can happen.

Now connecting Bluetooth 2.1 or later devices with Bluetooth 2.0 and
before devices are causing a regression.  The encryption key size check
needs to be moved out of the HCI connection handling into the L2CAP
channel setup.

To achieve this, the current check inside hci_conn_security() has been
moved into l2cap_check_enc_key_size() helper function and then called
from four decisions point inside L2CAP to cover all combinations of
Secure Simple Pairing enabled devices and device using legacy pairing
and legacy service security model.

Fixes: d5bb334a ("Bluetooth: Align minimum encryption key size for LE and BR/EDR connections")
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203643Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull networking fixes from David Miller:

 1) Fix leak of unqueued fragments in ipv6 nf_defrag, from Guillaume
    Nault.

 2) Don't access the DDM interface unless the transceiver implements it
    in bnx2x, from Mauro S. M. Rodrigues.

 3) Don't double fetch 'len' from userspace in sock_getsockopt(), from
    JingYi Hou.

 4) Sign extension overflow in lio_core, from Colin Ian King.

 5) Various netem bug fixes wrt. corrupted packets from Jakub Kicinski.

 6) Fix epollout hang in hvsock, from Sunil Muthuswamy.

 7) Fix regression in default fib6_type, from David Ahern.

 8) Handle memory limits in tcp_fragment more appropriately, from Eric
    Dumazet.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (24 commits)
  tcp: refine memory limit test in tcp_fragment()
  inet: clear num_timeout reqsk_alloc()
  net: mvpp2: debugfs: Add pmap to fs dump
  ipv6: Default fib6_type to RTN_UNICAST when not set
  net: hns3: Fix inconsistent indenting
  net/af_iucv: always register net_device notifier
  net/af_iucv: build proper skbs for HiperTransport
  net/af_iucv: remove GFP_DMA restriction for HiperTransport
  net: dsa: mv88e6xxx: fix shift of FID bits in mv88e6185_g1_vtu_loadpurge()
  hvsock: fix epollout hang from race condition
  net/udp_gso: Allow TX timestamp with UDP GSO
  net: netem: fix use after free and double free with packet corruption
  net: netem: fix backlog accounting for corrupted GSO frames
  net: lio_core: fix potential sign-extension overflow on large shift
  tipc: pass tunnel dev as NULL to udp_tunnel(6)_xmit_skb
  ip6_tunnel: allow not to count pkts on tstats by passing dev as NULL
  ip_tunnel: allow not to count pkts on tstats by setting skb's dev to NULL
  tun: wake up waitqueues after IFF_UP is set
  net: remove duplicate fetch in sock_getsockopt
  tipc: fix issues with early FAILOVER_MSG from peer
  ...

tcp_fragment() might be called for skbs in the write queue.

Memory limits might have been exceeded because tcp_sendmsg() only
checks limits at full skb (64KB) boundaries.

Therefore, we need to make sure tcp_fragment() wont punish applications
that might have setup very low SO_SNDBUF values.

Fixes: f070ef2a ("tcp: tcp_fragment() should apply sane memory limits")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Christoph Paasch <cpaasch@apple.com>
Tested-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull rdma fixes from Doug Ledford:
 "This is probably our last -rc pull request. We don't have anything
  else outstanding at the moment anyway, and with the summer months on
  us and people taking trips, I expect the next weeks leading up to the
  merge window to be pretty calm and sedate.

  This has two simple, no brainer fixes for the EFA driver.

  Then it has ten not quite so simple fixes for the hfi1 driver. The
  problem with them is that they aren't simply one liner typo fixes.
  They're still fixes, but they're more complex issues like livelock
  under heavy load where the answer was to change work queue usage and
  spinlock usage to resolve the problem, or issues with orphaned
  requests during certain types of failures like link down which
  required some more complex work to fix too. They all look like
  legitimate fixes to me, they just aren't small like I wish they were.

  Summary:

   - 2 minor EFA fixes

   - 10 hfi1 fixes related to scaling issues"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
  RDMA/efa: Handle mmap insertions overflow
  RDMA/efa: Fix success return value in case of error
  IB/hfi1: Handle port down properly in pio
  IB/hfi1: Handle wakeup of orphaned QPs for pio
  IB/hfi1: Wakeup QPs orphaned on wait list after flush
  IB/hfi1: Use aborts to trigger RC throttling
  IB/hfi1: Create inline to get extended headers
  IB/hfi1: Silence txreq allocation warnings
  IB/hfi1: Avoid hardlockup with flushlist_lock
  IB/hfi1: Correct tid qp rcd to match verbs context
  IB/hfi1: Close PSM sdma_progress sleep window
  IB/hfi1: Validate fault injection opcode user input

Pull more NFS client fixes from Anna Schumaker:
 "These are mostly refcounting issues that people have found recently.
  The revert fixes a suspend recovery performance issue.

   - SUNRPC: Fix a credential refcount leak

   - Revert "SUNRPC: Declare RPC timers as TIMER_DEFERRABLE"

   - SUNRPC: Fix xps refcount imbalance on the error path

   - NFS4: Only set creation opendata if O_CREAT"

* tag 'nfs-for-5.2-3' of git://git.linux-nfs.org/projects/anna/linux-nfs:
  SUNRPC: Fix a credential refcount leak
  Revert "SUNRPC: Declare RPC timers as TIMER_DEFERRABLE"
  net :sunrpc :clnt :Fix xps refcount imbalance on the error path
  NFS4: Only set creation opendata if O_CREAT

GCC 5.5.0 sometimes cleverly hoists reads of the pvclock and/or hvclock
pages before the vclock mode checks.  This creates a path through
vclock_gettime() in which no vclock is enabled at all (due to disabled
TSC on old CPUs, for example) but the pvclock or hvclock page
nevertheless read.  This will segfault on bare metal.

This fixes commit 459e3a21 ("gcc-9: properly declare the
{pv,hv}clock_page storage") in the sense that, before that commit, GCC
didn't seem to generate the offending code.  There was nothing wrong
with that commit per se, and -stable maintainers should backport this to
all supported kernels regardless of whether the offending commit was
present, since the same crash could just as easily be triggered by the
phase of the moon.

On GCC 9.1.1, this doesn't seem to affect the generated code at all, so
I'm not too concerned about performance regressions from this fix.

Cc: stable@vger.kernel.org
Cc: x86@kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Reported-by: Duncan Roe <duncan_roe@optusnet.com.au>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

All callers of __rpc_clone_client() pass in a value for args->cred,
meaning that the credential gets assigned and referenced in
the call to rpc_new_client().
Reported-by: Ido Schimmel <idosch@idosch.org>
Fixes: 79caa5fa ("SUNRPC: Cache cred of process creating the rpc_client")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Tested-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Jon Hunter reports:
  "I have been noticing intermittent failures with a system suspend test on
   some of our machines that have a NFS mounted root file-system. Bisecting
   this issue points to your commit 43123581 ("SUNRPC: Declare RPC
   timers as TIMER_DEFERRABLE") and reverting this on top of v5.2-rc3 does
   appear to resolve the problem.

   The cause of the suspend failure appears to be a long delay observed
   sometimes when resuming from suspend, and this is causing our test to
   timeout."

This reverts commit 43123581.
Reported-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

rpc_clnt_add_xprt take a reference to struct rpc_xprt_switch, but forget
to release it before return, may lead to a memory leak.
Signed-off-by: Lin Yi <teroincn@163.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

We can end up in nfs4_opendata_alloc during task exit, in which case
current->fs has already been cleaned up.  This leads to a crash in
current_umask().

Fix this by only setting creation opendata if we are actually doing an open
with O_CREAT.  We can drop the check for NULL nfs4_open_createattrs, since
O_CREAT will never be set for the recovery path.
Suggested-by: Trond Myklebust <trondmy@hammerspace.com>
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Pull ARM fix from Russell King:
 "Just one ARM fix this time around for Jason Donenfeld, fixing a
  problem with the VDSO generation on big endian"

* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: 8867/1: vdso: pass --be8 to linker if necessary

Pull drm fixes from Dave Airlie:
 "Just catching up on the week since back from holidays, everything
  seems quite sane.

  core:
   - copy_to_user fix for really legacy codepaths.

  vmwgfx:
   - two dma fixes
   - one virt hw interaction fix

  i915:
   - modesetting fix
   - gvt fix

  panfrost:
   - BO unmapping fix

  imx:
   - image converter fixes"

* tag 'drm-fixes-2019-06-21' of git://anongit.freedesktop.org/drm/drm:
  drm/i915: Don't clobber M/N values during fastset check
  drm: return -EFAULT if copy_to_user() fails
  drm/panfrost: Make sure a BO is only unmapped when appropriate
  drm/i915/gvt: ignore unexpected pvinfo write
  gpu: ipu-v3: image-convert: Fix image downsize coefficients
  gpu: ipu-v3: image-convert: Fix input bytesperline for packed formats
  gpu: ipu-v3: image-convert: Fix input bytesperline width/height align
  drm/vmwgfx: fix a warning due to missing dma_parms
  drm/vmwgfx: Honor the sg list segment size limitation
  drm/vmwgfx: Use the backdoor port if the HB port is not available

Pull staging/IIO/counter fixes from Greg KH:
 "Here are some small driver bugfixes for some staging/iio/counter
  drivers.

  Staging and IIO have been lumped together for a while, as those
  subsystems cross the areas a log, and counter is used by IIO, so
  that's why they are all in one pull request here.

  These are small fixes for reported issues in some iio drivers, the
  erofs filesystem, and a build issue for counter code.

  All have been in linux-next with no reported issues"

* tag 'staging-5.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: erofs: add requirements field in superblock
  counter/ftm-quaddec: Add missing dependencies in Kconfig
  staging: iio: adt7316: Fix build errors when GPIOLIB is not set
  iio: temperature: mlx90632 Relax the compatibility check
  iio: imu: st_lsm6dsx: fix PM support for st_lsm6dsx i2c controller
  staging:iio:ad7150: fix threshold mode config bit

Pull char/misc driver fixes from Greg KH:
 "Here are a number of small driver fixes for 5.2-rc6

  Nothing major, just fixes for reported issues:
   - soundwire fixes
   - thunderbolt fixes
   - MAINTAINERS update for fpga maintainer change
   - binder bugfix
   - habanalabs 64bit pointer fix
   - documentation updates

  All of these have been in linux-next with no reported issues"

* tag 'char-misc-5.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  habanalabs: use u64_to_user_ptr() for reading user pointers
  doc: fix documentation about UIO_MEM_LOGICAL using
  MAINTAINERS / Documentation: Thorsten Scherer is the successor of Gavin Schenk
  docs: fb: Add TER16x32 to the available font names
  MAINTAINERS: fpga: hand off maintainership to Moritz
  thunderbolt: Implement CIO reset correctly for Titan Ridge
  binder: fix possible UAF when freeing buffer
  thunderbolt: Make sure device runtime resume completes before taking domain lock
  soundwire: intel: set dai min and max channels correctly
  soundwire: stream: fix bad unlock balance
  soundwire: stream: fix out of boundary access on port properties

Pull USB fixes from Greg KH:
 "Here are four small USB fixes for 5.2-rc6.

  They include two xhci bugfixes, a chipidea fix, and a small dwc2 fix.
  Nothing major, just nice things to get resolved for reported issues.

  All have been in linux-next with no reported issues"

* tag 'usb-5.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  xhci: detect USB 3.2 capable host controllers correctly
  usb: xhci: Don't try to recover an endpoint if port is in error state.
  usb: dwc2: Use generic PHY width in params setup
  usb: chipidea: udc: workaround for endpoint conflict issue

Pull still more SPDX updates from Greg KH:
 "Another round of SPDX updates for 5.2-rc6

  Here is what I am guessing is going to be the last "big" SPDX update
  for 5.2. It contains all of the remaining GPLv2 and GPLv2+ updates
  that were "easy" to determine by pattern matching. The ones after this
  are going to be a bit more difficult and the people on the spdx list
  will be discussing them on a case-by-case basis now.

  Another 5000+ files are fixed up, so our overall totals are:
	Files checked:            64545
	Files with SPDX:          45529

  Compared to the 5.1 kernel which was:
	Files checked:            63848
	Files with SPDX:          22576

  This is a huge improvement.

  Also, we deleted another 20000 lines of boilerplate license crud,
  always nice to see in a diffstat"

* tag 'spdx-5.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx: (65 commits)
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 507
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 506
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 505
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 504
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 503
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 502
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 501
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 498
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 497
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 496
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 495
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 491
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 490
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 489
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 488
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 487
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 486
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 485
  ...

Pull cifs fixes from Steve French:
 "Four small SMB3 fixes, all for stable"

* tag '5.2-rc5-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: fix GlobalMid_Lock bug in cifs_reconnect
  SMB3: retry on STATUS_INSUFFICIENT_RESOURCES instead of failing write
  cifs: add spinlock for the openFileList to cifsInodeInfo
  cifs: fix panic in smb2_reconnect

drm/imx: ipu-v3 image converter fixes

This series fixes input buffer alignment and downsizer configuration
to adhere to IPU mem2mem CSC/scaler hardware restrictions in certain
downscaling ratios.
Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Philipp Zabel <p.zabel@pengutronix.de>
Link: https://patchwork.freedesktop.org/patch/msgid/1561040798.14349.20.camel@pengutronix.de

Merge tag 'drm-intel-fixes-2019-06-20' of git://anongit.freedesktop.org/drm/drm-intel into drm-fixes

drm/i915 fixes for v5.2-rc6:
- GVT: Fix reserved PVINFO register write (Weinan)
- Avoid clobbering M/N values in fastset fuzzy checks (Ville)
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/87pnn8sbdp.fsf@intel.com

panfrost- Only unmap BO's if they're mapped (Boris)
core- Handle buffer desc copy_to_user failure properly (Dan)

Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Sean Paul <sean@poorly.run>
Link: https://patchwork.freedesktop.org/patch/msgid/20190619192745.GA145841@art_vandelay