This commit adds kernel boot parameters torture.verbose_sleep_frequency
and torture.verbose_sleep_duration, which allow VERBOSE_TOROUT_*() output
to be throttled with periodic sleeps on large systems.
Signed-off-by: NPaul E. McKenney <paulmck@kernel.org>

This commit adds a short delay for verbose_batched-throttled printk()s
to further decrease console flooding.
Signed-off-by: NPaul E. McKenney <paulmck@kernel.org>

This commit replaces schedule_timeout_uninterruptible() and
schedule_timeout_interruptible() with torture_hrtimeout_us() and
torture_hrtimeout_jiffies() to avoid timer-wheel synchronization.
Signed-off-by: NPaul E. McKenney <paulmck@kernel.org>

This commit saves a few lines of code by making the stutter_wait()
and torture_stutter() functions use torture_hrtimeout_jiffies() and
torture_hrtimeout_us().
Signed-off-by: NPaul E. McKenney <paulmck@kernel.org>

Because rcu_torture_writer() and rcu_torture_fakewriter() predate
hrtimers, they do timer-wheel-decoupled timed waits by using the
timer-wheel-based schedule_timeout_interruptible() functions in
conjunction with a random udelay()-based wait.  This latter unnecessarily
burns CPU time, so this commit instead uses torture_hrtimeout_jiffies()
to decouple from the timer wheels without busy-waiting.
Signed-off-by: NPaul E. McKenney <paulmck@kernel.org>

This commit adds torture_hrtimeout_ns(), torture_hrtimeout_us(),
torture_hrtimeout_ms(), torture_hrtimeout_jiffies(), and
torture_hrtimeout_s(), each of which uses hrtimers to block for a fuzzed
time interval.  These functions are intended to be used by the various
torture tests to decouple wakeups from the timer wheel, thus providing
more opportunity for Murphy to insert destructive race conditions.
Signed-off-by: NPaul E. McKenney <paulmck@kernel.org>

Full testing of the new SRCU polling API requires that the fake
writers also use it in order to test concurrent calls to all of the API
members, especially start_poll_synchronize_srcu().  This commit makes
rcu_torture_fakewriter() use all available blocking grace-period-wait
primitives available from the RCU flavor under test.

Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/Reported-by: NKent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: NPaul E. McKenney <paulmck@kernel.org>

Full testing of the new SRCU polling API requires that the fake writers
also use it in order to test concurrent calls to all of the API members,
especially start_poll_synchronize_srcu().  This commit prepares the ground
for this by making the synctype[] and nsynctype variables be static
globals so that the rcu_torture_fakewriter() function can access them.
Initialization of these variables is moved from rcu_torture_writer()
to a new rcu_torture_write_types() function that is invoked from
rcu_torture_init() just before the first writer kthread is spawned.

Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/Reported-by: NKent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: NPaul E. McKenney <paulmck@kernel.org>

Currently, the rcu_torture_writer() function checks that all required
grace periods elapse during a stutter interval, which is a multi-second
time period during which the test load is removed.  However, this check
is suppressed during early boot (that is, before init is spawned) in
order to avoid false positives that otherwise occur due to heavy load
on the single boot CPU.

Unfortunately, this approach is insufficient.  It is possible that the
stutter interval might end just as init is spawned, so that early boot
conditions prevailed during almost the entire stutter interval.

This commit therefore takes a snapshot of boot-complete state just
before the stutter interval, thus suppressing the check for failure to
complete grace periods unless the entire stutter interval took place
after early boot.
Signed-off-by: NPaul E. McKenney <paulmck@kernel.org>

The refscale test prints enough per-kthread console output to provoke RCU
CPU stall warnings on large systems.  This commit therefore allows this
output to be summarized.  For example, the refscale.verbose_batched=32
boot parameter would causes only every 32nd line of output to be logged.
Signed-off-by: NPaul E. McKenney <paulmck@kernel.org>

This commit adds the desired CPU, the actual CPU, and nr_cpu_ids to
the wrong-CPU warning in scftorture_invoker(), the better to help with
debugging.
Signed-off-by: NPaul E. McKenney <paulmck@kernel.org>

RCU guarantees that anything seen by a given reader will also be seen
after any grace period that must wait on that reader.  This is very likely
to hold based on inspection, but the advantage of having rcutorture do
the inspecting is that rcutorture doesn't mind inspecting frequently
and often.

This commit therefore adds code to test RCU's global memory ordering.
Signed-off-by: NPaul E. McKenney <paulmck@kernel.org>

This commit adds reader-side testing of the polling grace-period API.
This testing verifies that a cookie obtained in an SRCU read-side critical
section does not get a true return from poll_state_synchronize_srcu()
within that same critical section.

Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/Reported-by: NKent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: NPaul E. McKenney <paulmck@kernel.org>

This commit adds writer-side testing of the polling grace-period API.
One test verifies that the polling API sees a grace period caused by
some other mechanism.  Another test verifies that using the polling API
to wait for a grace period does not result in too-short grace periods.
A third test verifies that the polling API does not report
completion within a read-side critical section.  A fourth and final
test verifies that the polling API does report completion given an
intervening grace period.

Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/Reported-by: NKent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: NPaul E. McKenney <paulmck@kernel.org>

The new get_state_synchronize_srcu(), start_poll_synchronize_srcu() and
poll_state_synchronize_srcu() functions need to be tested, and so this
commit prepares by renaming the rcu_torture_ops field ->get_state to
->get_gp_state in order to be consistent with the upcoming ->start_gp_poll
and ->poll_gp_state fields.

Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/Reported-by: NKent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: NPaul E. McKenney <paulmck@kernel.org>

This commit adds to the poll_state_synchronize_srcu() header comment
describing the issues surrounding SRCU cookie overflow/wrap for the
different kernel configurations.

Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/Reported-by: NKent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: NPaul E. McKenney <paulmck@kernel.org>

This commit adds requirements documentation for the
get_state_synchronize_srcu(), start_poll_synchronize_srcu(), and
poll_state_synchronize_srcu() functions.

Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/Reported-by: NKent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: NNeeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: NPaul E. McKenney <paulmck@kernel.org>

There is a need for a polling interface for SRCU grace
periods, so this commit supplies get_state_synchronize_srcu(),
start_poll_synchronize_srcu(), and poll_state_synchronize_srcu() for this
purpose.  The first can be used if future grace periods are inevitable
(perhaps due to a later call_srcu() invocation), the second if future
grace periods might not otherwise happen, and the third to check if a
grace period has elapsed since the corresponding call to either of the
first two.

As with get_state_synchronize_rcu() and cond_synchronize_rcu(),
the return value from either get_state_synchronize_srcu() or
start_poll_synchronize_srcu() must be passed in to a later call to
poll_state_synchronize_srcu().

Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/Reported-by: NKent Overstreet <kent.overstreet@gmail.com>
[ paulmck: Add EXPORT_SYMBOL_GPL() per kernel test robot feedback. ]
[ paulmck: Apply feedback from Neeraj Upadhyay. ]
Link: https://lore.kernel.org/lkml/20201117004017.GA7444@paulmck-ThinkPad-P72/Reviewed-by: NNeeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: NPaul E. McKenney <paulmck@kernel.org>

There is a need for a polling interface for SRCU grace
periods, so this commit supplies get_state_synchronize_srcu(),
start_poll_synchronize_srcu(), and poll_state_synchronize_srcu() for this
purpose.  The first can be used if future grace periods are inevitable
(perhaps due to a later call_srcu() invocation), the second if future
grace periods might not otherwise happen, and the third to check if a
grace period has elapsed since the corresponding call to either of the
first two.

As with get_state_synchronize_rcu() and cond_synchronize_rcu(),
the return value from either get_state_synchronize_srcu() or
start_poll_synchronize_srcu() must be passed in to a later call to
poll_state_synchronize_srcu().

Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/Reported-by: NKent Overstreet <kent.overstreet@gmail.com>
[ paulmck: Add EXPORT_SYMBOL_GPL() per kernel test robot feedback. ]
[ paulmck: Apply feedback from Neeraj Upadhyay. ]
Link: https://lore.kernel.org/lkml/20201117004017.GA7444@paulmck-ThinkPad-P72/Reviewed-by: NNeeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: NPaul E. McKenney <paulmck@kernel.org>

There is a need for a polling interface for SRCU grace periods.
This polling needs to initiate an SRCU grace period without having
to queue (and manage) a callback.  This commit therefore splits the
Tree SRCU __call_srcu() function into callback-initialization and
queuing/start-grace-period portions, with the latter in a new function
named srcu_gp_start_if_needed().  This function may be passed a NULL
callback pointer, in which case it will refrain from queuing anything.

Why have the new function mess with queuing?  Locking considerations,
of course!

Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/Reported-by: NKent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: NNeeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: NPaul E. McKenney <paulmck@kernel.org>

There is a need for a polling interface for SRCU grace periods.
This polling needs to initiate an SRCU grace period without
having to queue (and manage) a callback.  This commit therefore
splits the Tiny SRCU call_srcu() function into callback-queuing and
start-grace-period portions, with the latter in a new function named
srcu_gp_start_if_needed().

Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/Reported-by: NKent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: NNeeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: NPaul E. McKenney <paulmck@kernel.org>

There is a need for a polling interface for SRCU grace periods.  This
polling needs to distinguish between an SRCU instance being idle on the
one hand or in the middle of a grace period on the other.  This commit
therefore converts the Tiny SRCU srcu_struct structure's srcu_idx from
a defacto boolean to a free-running counter, using the bottom bit to
indicate that a grace period is in progress.  The second-from-bottom
bit is thus used as the index returned by srcu_read_lock().

Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/Reported-by: NKent Overstreet <kent.overstreet@gmail.com>
[ paulmck: Fix ->srcu_lock_nesting[] indexing per Neeraj Upadhyay. ]
Reviewed-by: NNeeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: NPaul E. McKenney <paulmck@kernel.org>

Since commit 36e2c742 ("fs: don't allow splice read/write without
explicit ops") we've required that file operation structures explicitly
enable splice support, rather than falling back to the default handlers.

Most /proc files use the indirect 'struct proc_ops' to describe their
file operations, and were fixed up to support splice earlier in commits
40be821d..b24c30c6, but the mountinfo files interact with the
VFS directly using their own 'struct file_operations' and got missed as
a result.

This adds the necessary support for splice to work for /proc/*/mountinfo
and friends.
Reported-by: NJoan Bruguera Micó <joanbrugueram@gmail.com>
Reported-by: NJussi Kivilinna <jussi.kivilinna@iki.fi>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=209971
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull NTB fixes from Jon Mason:
 "Bug fix for IDT NTB and Intel NTB LTR management support"

* tag 'ntb-5.11' of git://github.com/jonmason/ntb:
  ntb: intel: add Intel NTB LTR vendor support for gen4 NTB
  ntb: idt: fix error check in ntb_hw_idt.c

Pull crypto fixes from Herbert Xu:
 "Fix a number of autobuild failures due to missing Kconfig
  dependencies"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: qat - add CRYPTO_AES to Kconfig dependencies
  crypto: keembay - Add dependency on HAS_IOMEM
  crypto: keembay - CRYPTO_DEV_KEEMBAY_OCS_AES_SM4 should depend on ARCH_KEEMBAY

Pull objtool fix from Ingo Molnar:
 "Fix a segfault that occurs when built with Clang"

* tag 'objtool-urgent-2020-12-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Fix seg fault with Clang non-section symbols

Pull locking fixes from Ingo Molnar:
 "Misc fixes/updates:

   - Fix static keys usage in module __init sections

   - Add separate MAINTAINERS entry for static branches/calls

   - Fix lockdep splat with CONFIG_PREEMPTIRQ_EVENTS=y tracing"

* tag 'locking-urgent-2020-12-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  softirq: Avoid bad tracing / lockdep interaction
  jump_label/static_call: Add MAINTAINERS
  jump_label: Fix usage in module __init

Pull timer fixes from Ingo Molnar:
 "Update/fix two CPU sanity checks in the hotplug and the boot code, and
  fix a typo in the Kconfig help text.

  [ Context: the first two commits are the result of an ongoing
    annotation+review work of (intentional) tick_do_timer_cpu() data
    races reported by KCSAN, but the annotations aren't fully cooked
    yet ]"

* tag 'timers-urgent-2020-12-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timekeeping: Fix spelling mistake in Kconfig "fullfill" -> "fulfill"
  tick/sched: Remove bogus boot "safety" check
  tick: Remove pointless cpu valid check in hotplug code

Pull scheduler fix from Ingo Molnar:
 "Fix a context switch performance regression"

* tag 'sched-urgent-2020-12-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Optimize finish_lock_switch()

Commit c9a3c4e6 ("mfd: ab8500-debugfs: Remove extraneous curly
brace") removed a left-over curly brace that caused build failures, but
Joe Perches points out that the subsequent 'seq_putc()' should also be
removed, because the commit that caused all these problems already added
the final '\n' to the seq_printf() above it.
Reported-by: NJoe Perches <joe@perches.com>
Fixes: 886c8121 ("mfd: ab8500-debugfs: Remove the racy fiddling with irq_desc")
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull PCI fixes from Bjorn Helgaas:

 - Fix a tegra enumeration regression (Rob Herring)

 - Fix a designware-host check that warned on *success*, not failure
   (Alexander Lobakin)

* tag 'pci-v5.11-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI: dwc: Fix inverted condition of DMA mask setup warning
  PCI: tegra: Fix host link initialization

Clang errors:

  drivers/mfd/ab8500-debugfs.c:1526:2: error: non-void function does not return a value [-Werror,-Wreturn-type]
          }
          ^
  drivers/mfd/ab8500-debugfs.c:1528:2: error: expected identifier or '('
  return 0;
          ^
  drivers/mfd/ab8500-debugfs.c:1529:1: error: extraneous closing brace ('}')
  }
  ^
  3 errors generated.

The cleanup in ab8500_interrupts_show left a curly brace around, remove
it to fix the error.

Fixes: 886c8121 ("mfd: ab8500-debugfs: Remove the racy fiddling with irq_desc")
Signed-off-by: NNathan Chancellor <natechancellor@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 660c4865 ("PCI: dwc: Set 32-bit DMA mask for MSI target address
allocation") added dma_mask_set() call to explicitly set 32-bit DMA mask
for MSI message mapping, but for now it throws a warning on ret == 0, while
dma_set_mask() returns 0 in case of success.

Fix this by inverting the condition.

[bhelgaas: join string to make it greppable]
Fixes: 660c4865 ("PCI: dwc: Set 32-bit DMA mask for MSI target address allocation")
Link: https://lore.kernel.org/r/20201222150708.67983-1-alobakin@pm.meSigned-off-by: NAlexander Lobakin <alobakin@pm.me>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Commit b9ac0f9d ("PCI: dwc: Move dw_pcie_setup_rc() to DWC common
code") broke enumeration of downstream devices on Tegra:

In non-working case (next-20201211):

  0001:00:00.0 PCI bridge: NVIDIA Corporation Device 1ad2 (rev a1)
  0001:01:00.0 SATA controller: Marvell Technology Group Ltd. Device 9171 (rev 13)
  0005:00:00.0 PCI bridge: NVIDIA Corporation Device 1ad0 (rev a1)

In working case (v5.10-rc7):

  0001:00:00.0 PCI bridge: Molex Incorporated Device 1ad2 (rev a1)
  0001:01:00.0 SATA controller: Marvell Technology Group Ltd. Device 9171 (rev 13)
  0005:00:00.0 PCI bridge: Molex Incorporated Device 1ad0 (rev a1)
  0005:01:00.0 PCI bridge: PLX Technology, Inc. Device 3380 (rev ab)
  0005:02:02.0 PCI bridge: PLX Technology, Inc. Device 3380 (rev ab)
  0005:03:00.0 USB controller: PLX Technology, Inc. Device 3380 (rev ab)

The problem seems to be dw_pcie_setup_rc() is now called twice before and
after the link up handling. The fix is to move Tegra's link up handling to
.start_link() function like other DWC drivers. Tegra is a bit more
complicated than others as it re-inits the whole DWC controller to retry
the link. With this, the initialization ordering is restored to match the
prior sequence.

Fixes: b9ac0f9d ("PCI: dwc: Move dw_pcie_setup_rc() to DWC common code")
Link: https://lore.kernel.org/r/20201218143905.1614098-1-robh@kernel.orgReported-by: NMian Yousaf Kaukab <ykaukab@suse.de>
Tested-by: NMian Yousaf Kaukab <ykaukab@suse.de>
Signed-off-by: NRob Herring <robh@kernel.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Vidya Sagar <vidyas@nvidia.com>

clang (quite rightly) complains fairly loudly about the newly added
mpc1_get_mpc_out_mux() function returning an uninitialized value if the
'opp_id' checks don't pass.

This may not happen in practice, but the code really shouldn't return
garbage if the sanity checks don't pass.

So just initialize 'val' to zero to avoid the issue.

Fixes: 110b055b ("drm/amd/display: add getter routine to retrieve mpcc mux")
Cc: Josip Pavic <Josip.Pavic@amd.com>
Cc: Bindu Ramamurthy <bindu.r@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull more perf tools updates from Arnaldo Carvalho de Melo:

 - Refactor 'perf stat' per CPU/socket/die/thread aggregation fixing use
   cases in ARM machines.

 - Fix memory leak when synthesizing SDT probes in 'perf probe'.

 - Update kernel header copies related to KVM, epol_pwait. msr-index and
   powerpc and s390 syscall tables.

* tag 'perf-tools-2020-12-24' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (24 commits)
  perf probe: Fix memory leak when synthesizing SDT probes
  perf stat aggregation: Add separate thread member
  perf stat aggregation: Add separate core member
  perf stat aggregation: Add separate die member
  perf stat aggregation: Add separate socket member
  perf stat aggregation: Add separate node member
  perf stat aggregation: Start using cpu_aggr_id in map
  perf cpumap: Drop in cpu_aggr_map struct
  perf cpumap: Add new map type for aggregation
  perf stat: Replace aggregation ID with a struct
  perf cpumap: Add new struct for cpu aggregation
  perf cpumap: Use existing allocator to avoid using malloc
  perf tests: Improve topology test to check all aggregation types
  perf tools: Update s390's syscall.tbl copy from the kernel sources
  perf tools: Update powerpc's syscall.tbl copy from the kernel sources
  perf s390: Move syscall.tbl check into check-headers.sh
  perf powerpc: Move syscall.tbl check to check-headers.sh
  tools headers UAPI: Synch KVM's svm.h header with the kernel
  tools kvm headers: Update KVM headers from the kernel sources
  tools headers UAPI: Sync KVM's vmx.h header with the kernel sources
  ...

Pull coccinelle updates from Julia Lawall.

* 'for-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/jlawall/linux:
  scripts: coccicheck: Correct usage of make coccicheck
  coccinelle: update expiring email addresses
  coccinnelle: Remove ptr_ret script
  kbuild: do not use scripts/ld-version.sh for checking spatch version
  remove boolinit.cocci

Commit 64a1b95b ("genirq: Restrict export of irq_to_desc()") removed
the export of irq_to_desc() unless powerpc KVM is being built, because
there is still a use of irq_to_desc() in modular code there.

However it used:

  #ifdef CONFIG_KVM_BOOK3S_64_HV

Which doesn't work when that symbol is =m, leading to a build failure:

  ERROR: modpost: "irq_to_desc" [arch/powerpc/kvm/kvm-hv.ko] undefined!

Fix it by checking for the definedness of the correct symbol which is
CONFIG_KVM_BOOK3S_64_HV_MODULE.

Fixes: 64a1b95b ("genirq: Restrict export of irq_to_desc()")
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull misc vfs updates from Al Viro:
 "Assorted patches from previous cycle(s)..."

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fix hostfs_open() use of ->f_path.dentry
  Make sure that make_create_in_sticky() never sees uninitialized value of dir_mode
  fs: Kill DCACHE_DONTCACHE dentry even if DCACHE_REFERENCED is set
  fs: Handle I_DONTCACHE in iput_final() instead of generic_drop_inode()
  fs/namespace.c: WARN if mnt_count has become negative