When the prev and next task's mm change, switch_mm() provides the core
serializing guarantees before returning to usermode. The only case
where an explicit core serialization is needed is when the scheduler
keeps the same mm for prev and next.
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190919173705.2181-4-mathieu.desnoyers@efficios.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Checking that the number of threads is 1 is redundant with checking
mm_users == 1.

No change in functionality intended.
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190919173705.2181-3-mathieu.desnoyers@efficios.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Fix a logic flaw in the way membarrier_register_private_expedited()
handles ready state checks for private expedited sync core and private
expedited registrations.

If a private expedited membarrier registration is first performed, and
then a private expedited sync_core registration is performed, the ready
state check will skip the second registration when it really should not.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190919173705.2181-2-mathieu.desnoyers@efficios.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

The current task on the runqueue is currently read with rcu_dereference().

To obtain ordinary RCU semantics for an rcu_dereference() of rq->curr it needs
to be paired with rcu_assign_pointer() of rq->curr.  Which provides the
memory barrier necessary to order assignments to the task_struct
and the assignment to rq->curr.

Unfortunately the assignment of rq->curr in __schedule is a hot path,
and it has already been show that additional barriers in that code
will reduce the performance of the scheduler.  So I will attempt to
describe below why you can effectively have ordinary RCU semantics
without any additional barriers.

The assignment of rq->curr in init_idle is a slow path called once
per cpu and that can use rcu_assign_pointer() without any concerns.

As I write this there are effectively two users of rcu_dereference() on
rq->curr.  There is the membarrier code in kernel/sched/membarrier.c
that only looks at "->mm" after the rcu_dereference().  Then there is
task_numa_compare() in kernel/sched/fair.c.  My best reading of the
code shows that task_numa_compare only access: "->flags",
"->cpus_ptr", "->numa_group", "->numa_faults[]",
"->total_numa_faults", and "->se.cfs_rq".

The code in __schedule() essentially does:
	rq_lock(...);
	smp_mb__after_spinlock();

	next = pick_next_task(...);
	rq->curr = next;

	context_switch(prev, next);

At the start of the function the rq_lock/smp_mb__after_spinlock
pair provides a full memory barrier.  Further there is a full memory barrier
in context_switch().

This means that any task that has already run and modified itself (the
common case) has already seen two memory barriers before __schedule()
runs and begins executing.  A task that modifies itself then sees a
third full memory barrier pair with the rq_lock();

For a brand new task that is enqueued with wake_up_new_task() there
are the memory barriers present from the taking and release the
pi_lock and the rq_lock as the processes is enqueued as well as the
full memory barrier at the start of __schedule() assuming __schedule()
happens on the same cpu.

This means that by the time we reach the assignment of rq->curr
except for values on the task struct modified in pick_next_task
the code has the same guarantees as if it used rcu_assign_pointer().

Reading through all of the implementations of pick_next_task it
appears pick_next_task is limited to modifying the task_struct fields
"->se", "->rt", "->dl".  These fields are the sched_entity structures
of the varies schedulers.

Further "->se.cfs_rq" is only changed in cgroup attach/move operations
initialized by userspace.

Unless I have missed something this means that in practice that the
users of "rcu_dereference(rq->curr)" get normal RCU semantics of
rcu_dereference() for the fields the care about, despite the
assignment of rq->curr in __schedule() ot using rcu_assign_pointer.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20190903200603.GW2349@hirez.programming.kicks-ass.netSigned-off-by: Ingo Molnar <mingo@kernel.org>

Remove work arounds that were written before there was a grace period
after tasks left the runqueue in finish_task_switch().

In particular now that there tasks exiting the runqueue exprience
a RCU grace period none of the work performed by task_rcu_dereference()
excpet the rcu_dereference() is necessary so replace task_rcu_dereference()
with rcu_dereference().

Remove the code in rcuwait_wait_event() that checks to ensure the current
task has not exited.  It is no longer necessary as it is guaranteed
that any running task will experience a RCU grace period after it
leaves the run queueue.

Remove the comment in rcuwait_wake_up() as it is no longer relevant.

Ref: 8f95c90c ("sched/wait, RCU: Introduce rcuwait machinery")
Ref: 150593bf ("sched/api: Introduce task_rcu_dereference() and try_get_task_struct()")
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/87lfurdpk9.fsf_-_@x220.int.ebiederm.orgSigned-off-by: Ingo Molnar <mingo@kernel.org>

In the ordinary case today the RCU grace period for a task_struct is
triggered when another process wait's for it's zombine and causes the
kernel to call release_task().  As the waiting task has to receive a
signal and then act upon it before this happens, typically this will
occur after the original task as been removed from the runqueue.

Unfortunaty in some cases such as self reaping tasks it can be shown
that release_task() will be called starting the grace period for
task_struct long before the task leaves the runqueue.

Therefore use put_task_struct_rcu_user() in finish_task_switch() to
guarantee that the there is a RCU lifetime after the task
leaves the runqueue.

Besides the change in the start of the RCU grace period for the
task_struct this change may cause perf_event_delayed_put and
trace_sched_process_free.  The function perf_event_delayed_put boils
down to just a WARN_ON for cases that I assume never show happen.  So
I don't see any problem with delaying it.

The function trace_sched_process_free is a trace point and thus
visible to user space.  Occassionally userspace has the strangest
dependencies so this has a miniscule chance of causing a regression.
This change only changes the timing of when the tracepoint is called.
The change in timing arguably gives userspace a more accurate picture
of what is going on.  So I don't expect there to be a regression.

In the case where a task self reaps we are pretty much guaranteed that
the RCU grace period is delayed.  So we should get quite a bit of
coverage in of this worst case for the change in a normal threaded
workload.  So I expect any issues to turn up quickly or not at all.

I have lightly tested this change and everything appears to work
fine.
Inspired-by: Linus Torvalds <torvalds@linux-foundation.org>
Inspired-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/87r24jdpl5.fsf_-_@x220.int.ebiederm.orgSigned-off-by: Ingo Molnar <mingo@kernel.org>

Add a count of the number of RCU users (currently 1) of the task
struct so that we can later add the scheduler case and get rid of the
very subtle task_rcu_dereference(), and just use rcu_dereference().

As suggested by Oleg have the count overlap rcu_head so that no
additional space in task_struct is required.
Inspired-by: Linus Torvalds <torvalds@linux-foundation.org>
Inspired-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/87woebdplt.fsf_-_@x220.int.ebiederm.orgSigned-off-by: Ingo Molnar <mingo@kernel.org>

Clang reports this warning:

  kernel/locking/osq_lock.c:25:19: warning: unused function 'node_cpu' [-Wunused-function]

due to osq_lock() calling vcpu_is_preempted(node_cpu(node->prev))), but
vcpu_is_preempted() is compiled away. Fix it by converting the dummy
vcpu_is_preempted() from a macro to a proper static inline function.
Signed-off-by: Qian Cai <cai@lca.pw>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bsegall@google.com
Cc: dietmar.eggemann@arm.com
Cc: juri.lelli@redhat.com
Cc: rostedt@goodmis.org
Cc: vincent.guittot@linaro.org
Link: https://lkml.kernel.org/r/1568730894-10483-1-git-send-email-cai@lca.pwSigned-off-by: Ingo Molnar <mingo@kernel.org>

cfs_rq_clock_task() was first introduced and used in:

  f1b17280 ("sched: Maintain runnable averages across throttled periods")

Over time its use has been graduately removed by the following commits:

  d31b1a66 ("sched/fair: Factorize PELT update")
  23127296 ("sched/fair: Update scale invariance of PELT")

Today, there is no single user left, so it can be safely removed.

Found via the -Wunused-function build warning.
Signed-off-by: Qian Cai <cai@lca.pw>
Cc: Ben Segall <bsegall@google.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/1568668775-2127-1-git-send-email-cai@lca.pw
[ Rewrote the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Pull x86 platform-drivers updates from Andy Shevchenko:

 - ASUS WMI driver got a couple of updates, i.e. support of FAN is fixed
   for recent products and the charge threshold support has been added

 - Two uknown key events for Dell laptops are being ignored now to avoid
   spamming users with harmless messages

 - HP ZBook 17 G5 and ASUS Zenbook UX430UNR got accelerometer support.

 - Intel CherryTrail platforms had a regression with wake up. Now it's
   fixed

 - Intel PMC driver got fixed in order to work nicely in Xen
   environment

 - Intel Speed Select driver provides bucket vs core count relationship.
   Besides that the tools has been updated for better output

 - The PrivacyGuard is enabled on Lenovo ThinkPad laptops

 - Three tablets - Trekstor Primebook C11B 2-in-1, Irbis TW90 and Chuwi
   Surbook Mini - got touchscreen support

* tag 'platform-drivers-x86-v5.4-1' of git://git.infradead.org/linux-platform-drivers-x86: (53 commits)
  MAINTAINERS: Switch PDx86 subsystem status to Odd Fixes
  platform/x86: asus-wmi: Refactor charge threshold to use the battery hooking API
  platform/x86: asus-wmi: Rename CHARGE_THRESHOLD to RSOC
  platform/x86: asus-wmi: Reorder ASUS_WMI_CHARGE_THRESHOLD
  tools/power/x86/intel-speed-select: Display core count for bucket
  platform/x86: ISST: Allow additional TRL MSRs
  tools/power/x86/intel-speed-select: Fix memory leak
  tools/power/x86/intel-speed-select: Output success/failed for command output
  tools/power/x86/intel-speed-select: Output human readable CPU list
  tools/power/x86/intel-speed-select: Change turbo ratio output to maximum turbo frequency
  tools/power/x86/intel-speed-select: Switch output to MHz
  tools/power/x86/intel-speed-select: Simplify output for turbo-freq and base-freq
  tools/power/x86/intel-speed-select: Fix cpu-count output
  tools/power/x86/intel-speed-select: Fix help option typo
  tools/power/x86/intel-speed-select: Fix package typo
  tools/power/x86/intel-speed-select: Fix a read overflow in isst_set_tdp_level_msr()
  platform/x86: intel_int0002_vgpio: Use device_init_wakeup
  platform/x86: intel_int0002_vgpio: Fix wakeups not working on Cherry Trail
  platform/x86: compal-laptop: Initialize "value" in ec_read_u8()
  platform/x86: touchscreen_dmi: Add info for the Trekstor Primebook C11B 2-in-1
  ...

Pull x86 vmware updates from Ingo Molnar:
 "This updates the VMWARE guest driver with support for VMCALL/VMMCALL
  based hypercalls"

* 'x86-vmware-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  input/vmmouse: Update the backdoor call with support for new instructions
  drm/vmwgfx: Update the backdoor call with support for new instructions
  x86/vmware: Add a header file for hypercall definitions
  x86/vmware: Update platform detection code for VMCALL/VMMCALL hypercalls

Pull x86 hyperv updates from Ingo Molnar:
 "Misc updates related to page size abstractions within the HyperV code,
  in preparation for future features"

* 'x86-hyperv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  drivers: hv: vmbus: Replace page definition with Hyper-V specific one
  x86/hyperv: Add functions to allocate/deallocate page for Hyper-V
  x86/hyperv: Create and use Hyper-V page definitions

Pull x86 platform update from Ingo Molnar:
 "The biggest change is the rework of the intel/iosf_mbi locking code
  which used a few non-standard locking patterns, to make it work under
  lockdep"

* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/platform/uv: Fix kmalloc() NULL check routine
  x86/platform/intel/iosf_mbi Rewrite locking

Pull x86 mm updates from Ingo Molnar:

 - Make cpumask_of_node() more robust against invalid node IDs

 - Simplify and speed up load_mm_cr4()

 - Unexport and remove various unused set_memory_*() APIs

 - Misc cleanups

* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Fix cpumask_of_node() error condition
  x86/mm: Remove the unused set_memory_wt() function
  x86/mm: Remove set_pages_x() and set_pages_nx()
  x86/mm: Remove the unused set_memory_array_*() functions
  x86/mm: Unexport set_memory_x() and set_memory_nx()
  x86/fixmap: Cleanup outdated comments
  x86/kconfig: Remove X86_DIRECT_GBPAGES dependency on !DEBUG_PAGEALLOC
  x86/mm: Avoid redundant interrupt disable in load_mm_cr4()

Pull x86 entry updates from Ingo Molnar:
 "This contains x32 and compat syscall improvements, the biggest one of
  which splits x32 syscalls into their own table, which allows new
  syscalls to share the x32 and x86-64 number - which turns the
  512-547 special syscall numbers range into a legacy wart that won't be
  extended going forward"

* 'x86-entry-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/syscalls: Split the x32 syscalls into their own table
  x86/syscalls: Disallow compat entries for all types of 64-bit syscalls
  x86/syscalls: Use the compat versions of rt_sigsuspend() and rt_sigprocmask()
  x86/syscalls: Make __X32_SYSCALL_BIT be unsigned long

Pull x86 cpu-feature updates from Ingo Molnar:

 - Rework the Intel model names symbols/macros, which were decades of
   ad-hoc extensions and added random noise. It's now a coherent, easy
   to follow nomenclature.

 - Add new Intel CPU model IDs:
    - "Tiger Lake" desktop and mobile models
    - "Elkhart Lake" model ID
    - and the "Lightning Mountain" variant of Airmont, plus support code

 - Add the new AVX512_VP2INTERSECT instruction to cpufeatures

 - Remove Intel MPX user-visible APIs and the self-tests, because the
   toolchain (gcc) is not supporting it going forward. This is the
   first, lowest-risk phase of MPX removal.

 - Remove X86_FEATURE_MFENCE_RDTSC

 - Various smaller cleanups and fixes

* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits)
  x86/cpu: Update init data for new Airmont CPU model
  x86/cpu: Add new Airmont variant to Intel family
  x86/cpu: Add Elkhart Lake to Intel family
  x86/cpu: Add Tiger Lake to Intel family
  x86: Correct misc typos
  x86/intel: Add common OPTDIFFs
  x86/intel: Aggregate microserver naming
  x86/intel: Aggregate big core graphics naming
  x86/intel: Aggregate big core mobile naming
  x86/intel: Aggregate big core client naming
  x86/cpufeature: Explain the macro duplication
  x86/ftrace: Remove mcount() declaration
  x86/PCI: Remove superfluous returns from void functions
  x86/msr-index: Move AMD MSRs where they belong
  x86/cpu: Use constant definitions for CPU models
  lib: Remove redundant ftrace flag removal
  x86/crash: Remove unnecessary comparison
  x86/bitops: Use __builtin_constant_p() directly instead of IS_IMMEDIATE()
  x86: Remove X86_FEATURE_MFENCE_RDTSC
  x86/mpx: Remove MPX APIs
  ...

Pull x86 build cleanup from Ingo Molnar:
 "A single change that removes unnecessary asm-generic wrappers"

* 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/build: Remove unneeded uapi asm-generic wrappers

Pull x86 boot code cleanup from Ingo Molnar:
 "Clean up the BUILD_BUG_ON() definition which can cause build warnings"

* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot: Use common BUILD_BUG_ON

Pull x86 asm updates from Ingo Molnar:

 - Add UMIP emulation/spoofing for 64-bit processes as well, because of
   Wine based gaming.

 - Clean up symbols/labels in low level asm code

 - Add an assembly optimized mul_u64_u32_div() implementation on x86-64.

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/umip: Add emulation (spoofing) for UMIP covered instructions in 64-bit processes as well
  x86/asm: Make some functions local labels
  x86/asm/suspend: Get rid of bogus_64_magic
  x86/math64: Provide a sane mul_u64_u32_div() implementation for x86_64

Pull scheduler updates from Ingo Molnar:

 - MAINTAINERS: Add Mark Rutland as perf submaintainer, Juri Lelli and
   Vincent Guittot as scheduler submaintainers. Add Dietmar Eggemann,
   Steven Rostedt, Ben Segall and Mel Gorman as scheduler reviewers.

   As perf and the scheduler is getting bigger and more complex,
   document the status quo of current responsibilities and interests,
   and spread the review pain^H^H^H^H fun via an increase in the Cc:
   linecount generated by scripts/get_maintainer.pl. :-)

 - Add another series of patches that brings the -rt (PREEMPT_RT) tree
   closer to mainline: split the monolithic CONFIG_PREEMPT dependencies
   into a new CONFIG_PREEMPTION category that will allow the eventual
   introduction of CONFIG_PREEMPT_RT. Still a few more hundred patches
   to go though.

 - Extend the CPU cgroup controller with uclamp.min and uclamp.max to
   allow the finer shaping of CPU bandwidth usage.

 - Micro-optimize energy-aware wake-ups from O(CPUS^2) to O(CPUS).

 - Improve the behavior of high CPU count, high thread count
   applications running under cpu.cfs_quota_us constraints.

 - Improve balancing with SCHED_IDLE (SCHED_BATCH) tasks present.

 - Improve CPU isolation housekeeping CPU allocation NUMA locality.

 - Fix deadline scheduler bandwidth calculations and logic when cpusets
   rebuilds the topology, or when it gets deadline-throttled while it's
   being offlined.

 - Convert the cpuset_mutex to percpu_rwsem, to allow it to be used from
   setscheduler() system calls without creating global serialization.
   Add new synchronization between cpuset topology-changing events and
   the deadline acceptance tests in setscheduler(), which were broken
   before.

 - Rework the active_mm state machine to be less confusing and more
   optimal.

 - Rework (simplify) the pick_next_task() slowpath.

 - Improve load-balancing on AMD EPYC systems.

 - ... and misc cleanups, smaller fixes and improvements - please see
   the Git log for more details.

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits)
  sched/psi: Correct overly pessimistic size calculation
  sched/fair: Speed-up energy-aware wake-ups
  sched/uclamp: Always use 'enum uclamp_id' for clamp_id values
  sched/uclamp: Update CPU's refcount on TG's clamp changes
  sched/uclamp: Use TG's clamps to restrict TASK's clamps
  sched/uclamp: Propagate system defaults to the root group
  sched/uclamp: Propagate parent clamps
  sched/uclamp: Extend CPU's cgroup controller
  sched/topology: Improve load balancing on AMD EPYC systems
  arch, ia64: Make NUMA select SMP
  sched, perf: MAINTAINERS update, add submaintainers and reviewers
  sched/fair: Use rq_lock/unlock in online_fair_sched_group
  cpufreq: schedutil: fix equation in comment
  sched: Rework pick_next_task() slow-path
  sched: Allow put_prev_task() to drop rq->lock
  sched/fair: Expose newidle_balance()
  sched: Add task_struct pointer to sched_class::set_curr_task
  sched: Rework CPU hotplug task selection
  sched/{rt,deadline}: Fix set_next_task vs pick_next_task
  sched: Fix kerneldoc comment for ia64_set_curr_task
  ...

Pull perf updates from Ingo Molnar:
 "Kernel side changes:

   - Improved kbprobes robustness

   - Intel PEBS support for PT hardware tracing

   - Other Intel PT improvements: high order pages memory footprint
     reduction and various related cleanups

   - Misc cleanups

  The perf tooling side has been very busy in this cycle, with over 300
  commits. This is an incomplete high-level summary of the many
  improvements done by over 30 developers:

   - Lots of updates to the following tools:

      'perf c2c'
      'perf config'
      'perf record'
      'perf report'
      'perf script'
      'perf test'
      'perf top'
      'perf trace'

   - Updates to libperf and libtraceevent, and a consolidation of the
     proliferation of x86 instruction decoder libraries.

   - Vendor event updates for Intel and PowerPC CPUs,

   - Updates to hardware tracing tooling for ARM and Intel CPUs,

   - ... and lots of other changes and cleanups - see the shortlog and
     Git log for details"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (322 commits)
  kprobes: Prohibit probing on BUG() and WARN() address
  perf/x86: Make more stuff static
  x86, perf: Fix the dependency of the x86 insn decoder selftest
  objtool: Ignore intentional differences for the x86 insn decoder
  objtool: Update sync-check.sh from perf's check-headers.sh
  perf build: Ignore intentional differences for the x86 insn decoder
  perf intel-pt: Use shared x86 insn decoder
  perf intel-pt: Remove inat.c from build dependency list
  perf: Update .gitignore file
  objtool: Move x86 insn decoder to a common location
  perf metricgroup: Support multiple events for metricgroup
  perf metricgroup: Scale the metric result
  perf pmu: Change convert_scale from static to global
  perf symbols: Move mem_info and branch_info out of symbol.h
  perf auxtrace: Uninline functions that touch perf_session
  perf tools: Remove needless evlist.h include directives
  perf tools: Remove needless evlist.h include directives
  perf tools: Remove needless thread_map.h include directives
  perf tools: Remove needless thread.h include directives
  perf tools: Remove needless map.h include directives
  ...

Pull locking updates from Ingo Molnar:

 - improve rwsem scalability

 - add uninitialized rwsem debugging check

 - reduce lockdep's stacktrace memory usage and add diagnostics

 - misc cleanups, code consolidation and constification

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  mutex: Fix up mutex_waiter usage
  locking/mutex: Use mutex flags macro instead of hard code
  locking/mutex: Make __mutex_owner static to mutex.c
  locking/qspinlock,x86: Clarify virt_spin_lock_key
  locking/rwsem: Check for operations on an uninitialized rwsem
  locking/rwsem: Make handoff writer optimistically spin on owner
  locking/lockdep: Report more stack trace statistics
  locking/lockdep: Reduce space occupied by stack traces
  stacktrace: Constify 'entries' arguments
  locking/lockdep: Make it clear that what lock_class::key points at is not modified

Pull EFI updates from Ingo Molnar:

 - refactor the EFI config table handling across architectures

 - add support for the Dell EMC OEM config table

 - include AER diagnostic output to CPER handling of fatal PCIe errors

* 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: cper: print AER info of PCIe fatal error
  efi: Export Runtime Configuration Interface table to sysfs
  efi: ia64: move SAL systab handling out of generic EFI code
  efi/x86: move UV_SYSTAB handling into arch/x86
  efi: x86: move efi_is_table_address() into arch/x86

Pull stacktrace fixlet from Ingo Molnar:
 "Two comment fixes"

* 'core-stacktrace-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lib/stackdepot: Fix outdated comments

Pull RCU updates from Ingo Molnar:
 "This cycle's RCU changes were:

   - A few more RCU flavor consolidation cleanups.

   - Updates to RCU's list-traversal macros improving lockdep usability.

   - Forward-progress improvements for no-CBs CPUs: Avoid ignoring
     incoming callbacks during grace-period waits.

   - Forward-progress improvements for no-CBs CPUs: Use ->cblist
     structure to take advantage of others' grace periods.

   - Also added a small commit that avoids needlessly inflicting
     scheduler-clock ticks on callback-offloaded CPUs.

   - Forward-progress improvements for no-CBs CPUs: Reduce contention on
     ->nocb_lock guarding ->cblist.

   - Forward-progress improvements for no-CBs CPUs: Add ->nocb_bypass
     list to further reduce contention on ->nocb_lock guarding ->cblist.

   - Miscellaneous fixes.

   - Torture-test updates.

   - minor LKMM updates"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (86 commits)
  MAINTAINERS: Update from paulmck@linux.ibm.com to paulmck@kernel.org
  rcu: Don't include <linux/ktime.h> in rcutiny.h
  rcu: Allow rcu_do_batch() to dynamically adjust batch sizes
  rcu/nocb: Don't wake no-CBs GP kthread if timer posted under overload
  rcu/nocb: Reduce __call_rcu_nocb_wake() leaf rcu_node ->lock contention
  rcu/nocb: Reduce nocb_cb_wait() leaf rcu_node ->lock contention
  rcu/nocb: Advance CBs after merge in rcutree_migrate_callbacks()
  rcu/nocb: Avoid synchronous wakeup in __call_rcu_nocb_wake()
  rcu/nocb: Print no-CBs diagnostics when rcutorture writer unduly delayed
  rcu/nocb: EXP Check use and usefulness of ->nocb_lock_contended
  rcu/nocb: Add bypass callback queueing
  rcu/nocb: Atomic ->len field in rcu_segcblist structure
  rcu/nocb: Unconditionally advance and wake for excessive CBs
  rcu/nocb: Reduce ->nocb_lock contention with separate ->nocb_gp_lock
  rcu/nocb: Reduce contention at no-CBs invocation-done time
  rcu/nocb: Reduce contention at no-CBs registry-time CB advancement
  rcu/nocb: Round down for number of no-CBs grace-period kthreads
  rcu/nocb: Avoid ->nocb_lock capture by corresponding CPU
  rcu/nocb: Avoid needless wakeups of no-CBs grace-period kthread
  rcu/nocb: Make __call_rcu_nocb_wake() safe for many callbacks
  ...

Pull objtool build fix from Ingo Molnar:
 "Fix objtool builds with more exotic, user-defined CFLAGS"

* 'core-objtool-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Clobber user CFLAGS variable

Pull header documentation fix from Ingo Molnar:
 "Fix the parameter description <asm-generic/div64.h>"

* 'core-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  asm-generic/div64: Fix documentation of do_div() parameter

Pull ARM DT updates from Arnd Bergmann:
 "This is another huge branch with close to 450 changessets related to
  devicetree files, roughly half of this for 32-bit and 64-bit
  respectively. There are lots of cleanups and additional hardware
  support for platforms we already support based on SoCs from Renesas,
  ST-Microelectronics, Intel/Altera, Rockchips, Allwinner, Broadcom and
  other manufacturers.

  A total of 6 new SoCs and 37 new boards gets added this time, one more
  SoC will come in a follow-up branch. Most of the new boards are for
  64-bit ARM SoCs, the others are typically for the 32-bit Cortex-A7.

  Going more into details for SoC platforms with new hardware support:

   - The Snapdragon 855 (SM8150) is Qualcomm's current high-end phone
     platform, usually paired with an external 5G modem. So far we only
     support the Qualcomm SM8150 MTP reference platform, but no actual
     products.

   - For the slightly older Qualcomm platforms, support for several
     interesting products is getting added: Three laptops based on
     Snapdragon 835/MSM8998 (Asus NovaGo, HP Envy X2 and Lenovo Miix
     630), one laptop based on Snapdragon 850/sdm850 (Lenovo Yoga C630)
     and several phones based on the older Snapdragon 410/MSM8916
     (Samsung A3 and A5, Longcheer L8150 aka Android One 2nd gen "seed"
     aka Wileyfox Swift).

   - Mediatek MT7629 is a new wireless network router chip, similar to
     the older MT7623. It gets added together with the reference board
     implementation.

   - Allwinner V3 is a repackaged version of the existing low-end V3s
     chip, and is used in the tiny Lichee Pi Zero plus, also added here.
     There is also a new TV set-top box based on Allwinner H6, the Tanix
     TX6, and the eMMC variant of the Olimex A64-Olinuxino development
     board.

   - NXP i.MX8M Nano is a new member of the ever-expanding i.MX SoC
     family, similar to the i.MX8M Mini. As usual, there is a large
     number of new boards for i.MX SoCs: Einfochips i.MX8QXP AI_ML,
     SolidRun Hummingboard Pulse baseboard and System-on-Module,
     Boundary Devices i.MX8MQ Nitrogen8M, and TechNexion
     PICO-PI-IMX8M-DEV for the 64-bit i.MX8 line. For 32-bit, we get the
     Kontron i.MX6UL N6310 SoM with two baseboards, the PHYTEC
     phyBOARD-Segin SoM with three baseboards, and the Zodiac Inflight
     Innovations i.MX7 RMU2 board.

   - In a different NXP product line, the Layerscape LS1046A "Freeway"
     reference board gets added.

   - Amlogic SM1 (S905X3) and G12B (S922X, A311D) are updated chips from
     their set-top-box line and smart speaker with newer CPU and GPU
     cores compared to their predecessors. Both are now also supported
     by the Khadas VIM3 development board series, and the dts files for
     that get reorganized a bit to better deal with all variants.
     Another board based on SM1 that gets added is the SEI Robotics
     SEI610.

   - There are a handful of new x86 and Power9 server boards using
     Aspeed BMC chips that are gaining support for running Linux on the
     BMC through the OpenBMC project: Facebook
     Minipack/Wedge100/Wedge40, Lenovo Hr855xg2, and Mihawk. Notably
     these are still new machines using SoCs based on the ARM9 and ARM11
     CPU cores, as support for the new Cortex-A7 based AST2600 is still
     ramping up.

   - There are three new end-user products using 32-bit Rockchips SoCs:
     Mecer Xtreme Mini S6 is an Android "mini PC" box based on the
     low-end RK3229 chip, while the two AOpen products Chromebox Mini
     (Fievel) and Chromebase Mini (Tiger) run ChromeOS and are meant for
     commercial settings(digital signage, PoS, ...).

   - One more single-board computer based on the popular 64-bit RK3399
     is added: the Leez RK3399 P710"

* tag 'armsoc-dt' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (467 commits)
  arm64: dts: qcom: Add Lenovo Yoga C630
  ARM: dts: aspeed-g5: Fixe gpio-ranges upper limit
  ARM; dts: aspeed: mihawk: File should not be executable
  ARM: dts: aspeed: swift: Change power supplies to version 2
  ARM: dts: aspeed: vesnin: Add secondary SPI flash chip
  ARM: dts: aspeed: vesnin: Add wdt2 with alt-boot option
  ARM: dts: aspeed-g4: Add all flash chips
  ARM: dts: exynos: Enable GPU/Mali T604 on Arndale board
  ARM: dts: exynos: Enable GPU/Mali T604 on Chromebook Snow
  ARM: dts: exynos: Add GPU/Mali T604 node to Exynos5250
  ARM: dts: exynos: Fix min/max buck4 for GPU on Arndale board
  ARM: dts: exynos: Mark LDO10 as always-on on Peach Pit/Pi Chromebooks
  ARM: dts: exynos: Remove not accurate secondary ADC compatible
  arm64: dts: rockchip: limit clock rate of MMC controllers for RK3328
  arm64: dts: meson-sm1-sei610: add stdout-path property back
  arm64: dts: meson-sm1-sei610: enable DVFS
  arm64: dts: khadas-vim3: add support for the SM1 based VIM3L
  dt-bindings: arm: amlogic: add Amlogic SM1 based Khadas VIM3L bindings
  arm64: dts: khadas-vim3: move common nodes into meson-khadas-vim3.dtsi
  arm64: dts: meson: g12a: add reset to tdm formatters
  ...

Pull ARM SoC defconfig updates from Arnd Bergmann:
 "As usual, a bunch of commits, mostly adding drivers and other options
  to defconfigs after the code was merged through another tree"

* tag 'armsoc-defconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (32 commits)
  arm64: defconfig: Enable Qualcomm QUSB2 PHY
  arm64: defconfig: Enable the EFI Framebuffer
  arm64: defconfig: Enable Qualcomm GENI based I2C controller
  ARM: multi_v7_defconfig: Make MAX77802 regulator driver built-in
  arm64: defconfig: Enable CPU clock drivers for Qualcomm msm8916
  arm64: defconfig: Add DRM_MSM to defconfigs with ARCH_QCOM
  ARM: multi_v7_defconfig: Add DRM_MSM to defconfigs with ARCH_QCOM
  ARM: qcom_defconfig: Add DRM_MSM to defconfigs with ARCH_QCOM
  ARM: configs: aspeed_g5: Enable AST2600
  ARM: configs: multi_v7: Add ASPEED G6
  arm64: defconfig: Enable SM8150 GCC and pinctrl driver
  arm64: defconfig: Enable CONFIG_ACPI_APEI_PCIEAER
  arm64: defconfig: Enable the DesignWare watchdog
  ARM: multi_v7_defconfig: Enable SPI_STM32_QSPI support
  ARM: imx_v6_v7_defconfig: Enable the PSCI CPUidle driver
  arm64: defconfig: Enable the PSCI CPUidle driver
  arm64: defconfig: Enable Sun4i SPDIF module
  ARM: exynos_defconfig: Enable AHCI-platform SATA driver
  arm64: defconfig: CONFIG_DRM_ETNAVIV=m
  ARM: imx_v6_v7_defconfig: Select the OV5645 camera driver
  ...

Pull ARM SoC driver updates from Arnd Bergmann:
 "This contains driver changes that are tightly connected to SoC
  specific code. Aside from smaller cleanups and bug fixes, here is a
  list of the notable changes.

  New device drivers:

   - The Turris Mox router has a new "moxtet" bus driver for its
     on-board pluggable extension bus. The same platform also gains a
     firmware driver.

   - The Samsung Exynos family gains a new Chipid driver exporting using
     the soc device sysfs interface

   - A similar socinfo driver for Qualcomm Snapdragon chips.

   - A firmware driver for the NXP i.MX DSP IPC protocol using shared
     memory and a mailbox

  Other changes:

   - The i.MX reset controller driver now supports the NXP i.MX8MM chip

   - Amlogic SoC specific drivers gain support for the S905X3 and A311D
     chips

   - A rework of the TI Davinci framebuffer driver to allow important
     cleanups in the platform code

   - A couple of device drivers for removed ARM SoC platforms are
     removed. Most of the removals were picked up by other maintainers,
     this contains whatever was left"

* tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (123 commits)
  bus: uniphier-system-bus: use devm_platform_ioremap_resource()
  soc: ti: ti_sci_pm_domains: Add support for exclusive and shared access
  dt-bindings: ti_sci_pm_domains: Add support for exclusive and shared access
  firmware: ti_sci: Allow for device shared and exclusive requests
  bus: imx-weim: remove incorrect __init annotations
  fbdev: remove w90x900/nuc900 platform drivers
  spi: remove w90x900 driver
  net: remove w90p910-ether driver
  net: remove ks8695 driver
  firmware: turris-mox-rwtm: Add sysfs documentation
  firmware: Add Turris Mox rWTM firmware driver
  dt-bindings: firmware: Document cznic,turris-mox-rwtm binding
  bus: moxtet: fix unsigned comparison to less than zero
  bus: moxtet: remove set but not used variable 'dummy'
  ARM: scoop: Use the right include
  dt-bindings: power: add Amlogic Everything-Else power domains bindings
  soc: amlogic: Add support for Everything-Else power domains controller
  fbdev: da8xx: use resource management for dma
  fbdev: da8xx-fb: drop a redundant if
  fbdev: da8xx-fb: use devm_platform_ioremap_resource()
  ...

Pull ARM SoC platform updates from Arnd Bergmann:
 "The main change this time around is a cleanup of some of the oldest
  platforms based on the XScale and ARM9 CPU cores, which are between 10
  and 20 years old.

  The Kendin/Micrel/Microchip KS8695, Winbond/Nuvoton W90x900 and Intel
  IOP33x/IOP13xx platforms are removed after we determined that nobody
  is using them any more.

  The TI Davinci and NXP LPC32xx platforms on the other hand are still
  in active use and are converted to the ARCH_MULTIPLATFORM build,
  meaning that we can compile a kernel that works on these along with
  most other ARMv5 platforms. Changes toward that goal are also merged
  for IOP32x, but additional work is needed to complete this. Patches
  for the remaining ARMv5 platforms have started but need more work and
  some testing.

  Support for the new ASpeed AST2600 gets added, this is based on the
  Cortex-A7 ARMv7 core, and is a newer version of the existing ARMv5 and
  ARMv6 chips in the same family.

  Other changes include a cleanup of the ST-Ericsson ux500 platform and
  the move of the TI Davinci platform to a new clocksource driver"

[ The changes had marked INTEL_IOP_ADMA and USB_LPC32XX as being
  buildable on other platforms through COMPILE_TEST, but that causes new
  warnings that I most definitely do not want to see during the merge
  window as that could hide other issues.

  So the COMPILE_TEST option got disabled for them again   - Linus ]

* tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (61 commits)
  ARM: multi_v5_defconfig: make DaVinci part of the ARM v5 multiplatform build
  ARM: davinci: support multiplatform build for ARM v5
  arm64: exynos: Enable exynos-chipid driver
  ARM: OMAP2+: Delete an unnecessary kfree() call in omap_hsmmc_pdata_init()
  ARM: OMAP2+: move platform-specific asm-offset.h to arch/arm/mach-omap2
  ARM: davinci: dm646x: Fix a typo in the comment
  ARM: davinci: dm646x: switch to using the clocksource driver
  ARM: davinci: dm644x: switch to using the clocksource driver
  ARM: aspeed: Enable SMP boot
  ARM: aspeed: Add ASPEED AST2600 architecture
  ARM: aspeed: Select timer in each SoC
  dt-bindings: arm: cpus: Add ASPEED SMP
  ARM: imx: stop adjusting ar8031 phy tx delay
  mailmap: map old company name to new one @microchip.com
  MAINTAINERS: at91: remove the TC entry
  MAINTAINERS: at91: Collect all pinctrl/gpio drivers in same entry
  ARM: at91: move platform-specific asm-offset.h to arch/arm/mach-at91
  MAINTAINERS: Extend patterns for Samsung SoC, Security Subsystem and clock drivers
  ARM: s3c64xx: squash samsung_usb_phy.h into setup-usb-phy.c
  ARM: debug-ll: Add support for r7s9210
  ...

Pull parisc updates from Helge Deller:

 - Make the powerpc implementation to read elf files available as a
   public kexec interface so it can be re-used on other architectures
   (Sven)

 - Implement kexec on parisc (Sven)

 - Add kprobes on ftrace on parisc (Sven)

 - Fix kernel crash with HSC-PCI cards based on card-mode Dino

 - Add assembly implementations for memset, strlen, strcpy, strncpy and
   strcat

 - Some cleanups, documentation updates, warning fixes, ...

* 'parisc-5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: (25 commits)
  parisc: Have git ignore generated real2.S and firmware.c
  parisc: Disable HP HSC-PCI Cards to prevent kernel crash
  parisc: add support for kexec_file_load() syscall
  parisc: wire up kexec_file_load syscall
  parisc: add kexec syscall support
  parisc: add __pdc_cpu_rendezvous()
  kprobes/parisc: remove arch_kprobe_on_func_entry()
  kexec_elf: support 32 bit ELF files
  kexec_elf: remove unused variable in kexec_elf_load()
  kexec_elf: remove Elf_Rel macro
  kexec_elf: remove PURGATORY_STACK_SIZE
  kexec_elf: remove parsing of section headers
  kexec_elf: change order of elf_*_to_cpu() functions
  kexec: add KEXEC_ELF
  parisc: Save some bytes in dino driver
  parisc: Drop comments which are already in pci.h
  parisc: Convert eisa_enumerator to use pr_cont()
  parisc: Avoid warning when loading hppb driver
  parisc: speed up flush_tlb_all_local with qemu
  parisc: Add ALTERNATIVE_CODE() and ALT_COND_RUN_ON_QEMU
  ...

Pull ia64 updates from Tony Luck:
 "The big change here is removal of support for SGI Altix"

* tag 'please-pull-ia64_for_5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux: (33 commits)
  genirq: remove the is_affinity_mask_valid hook
  ia64: remove CONFIG_SWIOTLB ifdefs
  ia64: remove support for machvecs
  ia64: move the screen_info setup to common code
  ia64: move the ROOT_DEV setup to common code
  ia64: rework iommu probing
  ia64: remove the unused sn_coherency_id symbol
  ia64: remove the SGI UV simulator support
  ia64: remove the zx1 swiotlb machvec
  ia64: remove CONFIG_ACPI ifdefs
  ia64: remove CONFIG_PCI ifdefs
  ia64: remove the hpsim platform
  ia64: remove now unused machvec indirections
  ia64: remove support for the SGI SN2 platform
  drivers: remove the SGI SN2 IOC4 base support
  drivers: remove the SGI SN2 IOC3 base support
  qla2xxx: remove SGI SN2 support
  qla1280: remove SGI SN2 support
  misc/sgi-xp: remove SGI SN2 support
  char/mspec: remove SGI SN2 support
  ...

Pull RISC-V updates from Paul Walmsley:
 "Add the following new features:

   - Generic CPU topology description support for DT-based platforms,
     including ARM64, ARM and RISC-V.

   - Sparsemem support

   - Perf callchain support

   - SiFive PLIC irqchip modifications, in preparation for M-mode Linux

  and clean up the code base:

   - Clean up chip-specific register (CSR) manipulation code, IPIs, TLB
     flushing, and the RISC-V CPU-local timer code

   - Kbuild cleanup from one of the Kbuild maintainers"

[ The CPU topology parts came in through the arm64 tree with a shared
  branch   - Linus ]

* tag 'riscv/for-v5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  irqchip/sifive-plic: set max threshold for ignored handlers
  riscv: move the TLB flush logic out of line
  riscv: don't use the rdtime(h) pseudo-instructions
  riscv: cleanup riscv_cpuid_to_hartid_mask
  riscv: optimize send_ipi_single
  riscv: cleanup send_ipi_mask
  riscv: refactor the IPI code
  riscv: Add support for libdw
  riscv: Add support for perf registers sampling
  riscv: Add perf callchain support
  riscv: add arch/riscv/Kbuild
  RISC-V: Implement sparsemem
  riscv: Using CSR numbers to access CSRs

Pull m68k updates from Geert Uytterhoeven:

 - ioremap() cleanups

 - defconfig updates

 - small fixes and cleanups

* tag 'm68k-for-v5.4-tag1' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
  m68k: Remove ioremap_fullcache()
  m68k: Simplify ioremap_nocache()
  m68k: defconfig: Update defconfigs for v5.3-rc2
  m68k: atari: Rename shifter to shifter_st to avoid conflict
  m68k: Prevent some compiler warnings in Coldfire builds
  m68k: mac: Revisit floppy disc controller base addresses

Pull arm64 updates from Will Deacon:
 "Although there isn't tonnes of code in terms of line count, there are
  a fair few headline features which I've noted both in the tag and also
  in the merge commits when I pulled everything together.

  The part I'm most pleased with is that we had 35 contributors this
  time around, which feels like a big jump from the usual small group of
  core arm64 arch developers. Hopefully they all enjoyed it so much that
  they'll continue to contribute, but we'll see.

  It's probably worth highlighting that we've pulled in a branch from
  the risc-v folks which moves our CPU topology code out to where it can
  be shared with others.

  Summary:

   - 52-bit virtual addressing in the kernel

   - New ABI to allow tagged user pointers to be dereferenced by
     syscalls

   - Early RNG seeding by the bootloader

   - Improve robustness of SMP boot

   - Fix TLB invalidation in light of recent architectural
     clarifications

   - Support for i.MX8 DDR PMU

   - Remove direct LSE instruction patching in favour of static keys

   - Function error injection using kprobes

   - Support for the PPTT "thread" flag introduced by ACPI 6.3

   - Move PSCI idle code into proper cpuidle driver

   - Relaxation of implicit I/O memory barriers

   - Build with RELR relocations when toolchain supports them

   - Numerous cleanups and non-critical fixes"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (114 commits)
  arm64: remove __iounmap
  arm64: atomics: Use K constraint when toolchain appears to support it
  arm64: atomics: Undefine internal macros after use
  arm64: lse: Make ARM64_LSE_ATOMICS depend on JUMP_LABEL
  arm64: asm: Kill 'asm/atomic_arch.h'
  arm64: lse: Remove unused 'alt_lse' assembly macro
  arm64: atomics: Remove atomic_ll_sc compilation unit
  arm64: avoid using hard-coded registers for LSE atomics
  arm64: atomics: avoid out-of-line ll/sc atomics
  arm64: Use correct ll/sc atomic constraints
  jump_label: Don't warn on __exit jump entries
  docs/perf: Add documentation for the i.MX8 DDR PMU
  perf/imx_ddr: Add support for AXI ID filtering
  arm64: kpti: ensure patched kernel text is fetched from PoU
  arm64: fix fixmap copy for 16K pages and 48-bit VA
  perf/smmuv3: Validate groups for global filtering
  perf/smmuv3: Validate group size
  arm64: Relax Documentation/arm64/tagged-pointers.rst
  arm64: kvm: Replace hardcoded '1' with SYS_PAR_EL1_F
  arm64: mm: Ignore spurious translation faults taken from the kernel
  ...

Pull iommu updates from Joerg Roedel:

 - batched unmap support for the IOMMU-API

 - support for unlocked command queueing in the ARM-SMMU driver

 - rework the ATS support in the ARM-SMMU driver

 - more refactoring in the ARM-SMMU driver to support hardware
   implemention specific quirks and errata

 - bounce buffering DMA-API implementatation in the Intel VT-d driver
   for untrusted devices (like Thunderbolt devices)

 - fixes for runtime PM support in the OMAP iommu driver

 - MT8183 IOMMU support in the Mediatek IOMMU driver

 - rework of the way the IOMMU core sets the default domain type for
   groups. Changing the default domain type on x86 does not require two
   kernel parameters anymore.

 - more smaller fixes and cleanups

* tag 'iommu-updates-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (113 commits)
  iommu/vt-d: Declare Broadwell igfx dmar support snafu
  iommu/vt-d: Add Scalable Mode fault information
  iommu/vt-d: Use bounce buffer for untrusted devices
  iommu/vt-d: Add trace events for device dma map/unmap
  iommu/vt-d: Don't switch off swiotlb if bounce page is used
  iommu/vt-d: Check whether device requires bounce buffer
  swiotlb: Split size parameter to map/unmap APIs
  iommu/omap: Mark pm functions __maybe_unused
  iommu/ipmmu-vmsa: Disable cache snoop transactions on R-Car Gen3
  iommu/ipmmu-vmsa: Move IMTTBCR_SL0_TWOBIT_* to restore sort order
  iommu: Don't use sme_active() in generic code
  iommu/arm-smmu-v3: Fix build error without CONFIG_PCI_ATS
  iommu/qcom: Use struct_size() helper
  iommu: Remove wrong default domain comments
  iommu/dma: Fix for dereferencing before null checking
  iommu/mediatek: Clean up struct mtk_smi_iommu
  memory: mtk-smi: Get rid of need_larbid
  iommu/mediatek: Fix VLD_PA_RNG register backup when suspend
  memory: mtk-smi: Add bus_sel for mt8183
  memory: mtk-smi: Invoke pm runtime_callback to enable clocks
  ...

Pull GPIO updates from Linus Walleij:
 "This is the bulk of changes in the GPIO subsystem for the v5.4 kernel
  cycle.

  Core changes:

   - Support hierarchical GPIO irqchips.

     We now have three consumers that can use this: Intel IXP4xx,
     ThunderX and Qualcomm SPMI GPIO (in the pinctrl subsystem).

     The support code has been long in the making and hashed out so it
     should be easily adaptable for all hierarchical irqchip parents.
     The code only gets compiled in if hierarchical irqchip is used at
     the topmost irq controller at least, as the hierarchical irqchip
     requires strict hierarchy all the way up in the system.

   - Determine the need for a "valid_mask" for GPIO lines on the
     gpio_chip and conversely for the "valid_mask" for the GPIO
     interrupt chip interrupt lines by looking for a .init_valid_mask()
     callback in the main chip or GPIO interrupt chip respectively.
     Allocate it with bitmap_alloc().

   - Isolate the device tree/open firmware GPIO description code out in
     its own file properly.

   - Isolate the ACPI GPIO description code out in its own file
     properly.

   - Drop a whole lot of #ifdef:s in the main includes: it does not hurt
     to keep the include items around, and we get quicker and clearer
     compile failures if the appropriate kernel symbols are not selected
     for drivers.

  New/deleted drivers:

   - New driver for Aspeed SGPIO.

   - The KS8695 driver is deleted as the platform gets deleted from
     arch/arm in this kernel cycle.

   - The Cirrus Logic Madera driver now supports CS47L92 and CS47L15.

   - The Freescale MPC8xxx now supports LS1028A and LS1088A.

  Driver improvements:

   - We pass the GPIO irqchip intialization by directly filling in the
     struct instead of using set-up functions (the new way) for Intel
     MID, Lynxpoint, Merrifield, XLP, HLWD, Aspeed, ZX, VF610, TQMX86,
     MT7621, Zynq and EP93xx.

  Out-of-band changes:

   - Fix a GPIO header inclusion in Unicore - no response from
     maintainer.

   - Drop FMC subsystem from MAINTAINERS - was deleted in the GPIO tree
     last cycle so let's mop up the shards"

* tag 'gpio-v5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (82 commits)
  gpiolib: of: add a fallback for wlf,reset GPIO name
  gpio: htc-egpio: Remove unused exported htc_egpio_get_wakeup_irq()
  gpio: remove explicit comparison with 0
  gpio: creg-snps: use devm_platform_ioremap_resource() to simplify code
  gpio: devres: Switch to EXPORT_SYMBOL_GPL()
  gpio: of: Switch to EXPORT_SYMBOL_GPL()
  gpio: of: Make of_gpio_simple_xlate() private
  gpio: of: Make of_get_named_gpiod_flags() private
  gpio: aspeed: Add in ast2600 details to Aspeed driver
  gpio: aspeed: Use ngpio property from device tree if available
  gpio: aspeed: Setup irqchip dynamically
  gpio/aspeed: Fix incorrect number of banks
  gpio: aspeed: Update documentation with ast2600 controllers
  gpio: Initialize the irqchip valid_mask with a callback
  gpiolib: acpi: make acpi_can_fallback_to_crs() static
  gpio: Fix further merge errors
  gpio: Fix up merge collision in include file
  gpio: of: Normalize return code variable name
  gpio: gpiolib: Normalize return code variable name
  gpio: ep93xx: Pass irqchip when adding gpiochip
  ...

Pull i3c updates from Boris Brezillon:
 "Core changes:

   - Export i3c_device_match_id() so driver can get per-device data

   - Add addr and lvr fields to i2c_dev_desc so we can attach I2C
     devices that are not described in the DT

   - Add a missing of_node_put()

   - Fix a memory leak

   - Use dev_to_i3cmaster() instead of open-coding it

  Driver changes:

   - Use for_each_set_bit() in the Cadence driver"

* tag 'i3c/for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux:
  i3c: master: Use dev_to_i3cmaster()
  i3c: master: fix a memory leak bug
  i3c: add addr and lvr to i2c_dev_desc structure
  i3c: master: cdns: Use for_each_set_bit()
  i3c: master: Add of_node_put() before return
  i3c: move i3c_device_match_id to device.c and export it

Pull spi updates from Mark Brown:
 "The big theme for this release has been performance, we've had a
  series of unrelated overhauls of a few drivers all with a big
  peformance component.

  Otherwise it's been relatively quiet, highlights include:

   - A big overhaul of the spi-fsl-dspi driver improving the code
     quality, performance and stability from Vladimir Oltean.

   - A big performance enhancement for the bc2835 (Raspberry Pi) driver
     for unidirectional transfers from Lukas Wunner.

   - Improved performance on small transfers for the uniphier driver
     from Keiji Hayashibara.

   - Lots of coccinelle generated cleanups from Yue Haibing.

   - New device support for Freescale ls2080a and Nuvoton NPCM FIU"

* tag 'spi-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (102 commits)
  spi: mediatek: support large PA
  spi: mediatek: add spi support for mt6765 IC
  dt-bindings: spi: update bindings for MT6765 SoC
  spi: bcm2835: Speed up RX-only DMA transfers by zero-filling TX FIFO
  spi: bcm2835: Speed up TX-only DMA transfers by clearing RX FIFO
  dmaengine: bcm2835: Avoid accessing memory when copying zeroes
  spi: bcm2835: Cache CS register value for ->prepare_message()
  dmaengine: bcm2835: Document struct bcm2835_dmadev
  spi: Guarantee cacheline alignment of driver-private data
  dmaengine: bcm2835: Allow reusable descriptors
  dmaengine: bcm2835: Allow cyclic transactions without interrupt
  spi: bcm2835: Drop dma_pending flag
  spi: bcm2835: Work around DONE bit erratum
  spi-gpio: Use PTR_ERR_OR_ZERO() in spi_gpio_request()
  spi: Use an abbreviated pointer to ctlr->cur_msg in __spi_pump_messages
  spi: npcm-fiu: remove set but not used variable 'retlen'
  spi: fsl-spi: use devm_platform_ioremap_resource() to simplify code
  spi: zynq-qspi: use devm_platform_ioremap_resource() to simplify code
  spi: zynqmp: use devm_platform_ioremap_resource() to simplify code
  spi: xlp: use devm_platform_ioremap_resource() to simplify code
  ...