SCSI currently uses an atomic variable to track queue depth for each
attached device. The queue depth depends on many factors such as transport
type and device implementation. In addition, the SCSI device queue depth is
not a static entity but changes over time as a result of congestion
management.

While blk-mq currently tracks queue depth for each hctx, it can't easily be
changed to accommodate the SCSI per-device requirement.

The current approach of using an atomic variable doesn't scale well when
there are lots of CPU cores and the disk is very fast. IOPS can be
substantially impacted by the atomic in the hot path.

Replace the atomic variable sdev->device_busy with an sbitmap for tracking
the SCSI device queue depth.

It has been observed that IOPS is improved ~30% by this patchset in the
following test:

1) test machine(32 logical CPU cores)
	Thread(s) per core:  2
	Core(s) per socket:  8
	Socket(s):           2
	NUMA node(s):        2
	Model name:          Intel(R) Xeon(R) Silver 4110 CPU @ 2.10GHz

2) setup scsi_debug:
modprobe scsi_debug virtual_gb=128 max_luns=1 submit_queues=32 delay=0 max_queue=256

3) fio script:
fio --rw=randread --size=128G --direct=1 --ioengine=libaio --iodepth=2048 \
	--numjobs=32 --bs=4k --group_reporting=1 --group_reporting=1 --runtime=60 \
	--loops=10000 --name=job1 --filename=/dev/sdN

[mkp: fix device_busy reference in mpt3sas]

Link: https://lore.kernel.org/r/20210122023317.687987-14-ming.lei@redhat.com
Link: https://lore.kernel.org/linux-block/20200119071432.18558-6-ming.lei@redhat.com/
Cc: Omar Sandoval <osandov@fb.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Cc: Ewan D. Milne <emilne@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Tested-by: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Limit SCSI device's queue depth to max(host->can_queue, 1024) in
scsi_change_queue_depth(). 1024 is big enough for saturating current fast
SCSI LUN(SSD or RAID volume on multiple SSDs). Also single hardware queue
depth is usually enough for saturating single LUN because per-core
performance is often considered in storage design.

This patch is needed for replacing sdev->device_busy with sbitmap which has
to be pre-allocated with reasonable max depth.

Link: https://lore.kernel.org/r/20210122023317.687987-13-ming.lei@redhat.com
Cc: Omar Sandoval <osandov@fb.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Cc: Ewan D. Milne <emilne@redhat.com>
Tested-by: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Add scsi_device_busy() helper to prepare drivers for tracking device queue
depth via sbitmap_queue.

Link: https://lore.kernel.org/r/20210122023317.687987-12-ming.lei@redhat.com
Cc: Omar Sandoval <osandov@fb.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Cc: Ewan D. Milne <emilne@redhat.com>
Tested-by: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Use local tracking of per-sdev outstanding command since sdev_busy in SCSI
mid layer is improved for performance reason using sbitmap (earlier it was
atomic variable).

Link: https://lore.kernel.org/r/20210122023317.687987-11-ming.lei@redhat.com
Cc: Omar Sandoval <osandov@fb.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Cc: Ewan D. Milne <emilne@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Kashyap Desai <kashyap.desai@broadcom.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

The following three fields of scsi_host_template are referenced in the SCSI
I/O submission hot path. Put them together in one cacheline:

 - cmd_size

 - queuecommand

 - commit_rqs

Link: https://lore.kernel.org/r/20210122023317.687987-10-ming.lei@redhat.com
Cc: Omar Sandoval <osandov@fb.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Cc: Ewan D. Milne <emilne@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Tested-by: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

SCSI uses a global atomic variable to track queue depth for each
LUN/request queue.

This doesn't scale well when there are lots of CPU cores and the disk is
very fast. It has been observed that IOPS is affected a lot by tracking
queue depth via sdev->device_busy in the I/O path.

Return budget token from .get_budget callback. The budget token can be
passed to driver so that we can replace the atomic variable with
sbitmap_queue and alleviate the scaling problems that way.

Link: https://lore.kernel.org/r/20210122023317.687987-9-ming.lei@redhat.com
Cc: Omar Sandoval <osandov@fb.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Cc: Ewan D. Milne <emilne@redhat.com>
Tested-by: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Since SCSI is the only driver which requires dispatch budget move the token
from struct request to struct scsi_cmnd.

Link: https://lore.kernel.org/r/20210122023317.687987-8-ming.lei@redhat.com
Cc: Omar Sandoval <osandov@fb.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Cc: Ewan D. Milne <emilne@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Tested-by: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Move code for calculating default shift into a public helper which can be
used by SCSI.

Link: https://lore.kernel.org/r/20210122023317.687987-7-ming.lei@redhat.com
Cc: Omar Sandoval <osandov@fb.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Cc: Ewan D. Milne <emilne@redhat.com>
Tested-by: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

SCSI's .device_busy will be converted to sbitmap and sbitmap_weight is
needed. Export the helper.

The only existing user of sbitmap_weight() uses it to find out how many
bits are set and not cleared. Align sbitmap_weight() meaning with this
usage model.

Link: https://lore.kernel.org/r/20210122023317.687987-6-ming.lei@redhat.com
Cc: Omar Sandoval <osandov@fb.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Cc: Ewan D. Milne <emilne@redhat.com>
Tested-by: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Allocation hint should have belonged to sbitmap. Also, when sbitmap's depth
is high and there is no need to use mulitple wakeup queues, user can
benefit from percpu allocation hint too.

Move allocation hint into sbitmap, then SCSI device queue can benefit from
allocation hint when converting to plain sbitmap.

Convert vhost/scsi.c to use sbitmap allocation with percpu alloc hint. This
is more efficient than the previous approach.

Link: https://lore.kernel.org/r/20210122023317.687987-5-ming.lei@redhat.com
Cc: Omar Sandoval <osandov@fb.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Cc: Ewan D. Milne <emilne@redhat.com>
Cc: Mike Christie <michael.christie@oracle.com>
Cc: virtualization@lists.linux-foundation.org
Tested-by: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Add helpers for updating allocation hint so that we can avoid duplicate
code.

Prepare for moving allocation hint into sbitmap.

Link: https://lore.kernel.org/r/20210122023317.687987-4-ming.lei@redhat.com
Cc: Omar Sandoval <osandov@fb.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Cc: Ewan D. Milne <emilne@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Tested-by: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Currently the allocation round_robin info is maintained by sbitmap_queue.

However, bit allocation really belongs to sbitmap. Move it there.

Link: https://lore.kernel.org/r/20210122023317.687987-3-ming.lei@redhat.com
Cc: Omar Sandoval <osandov@fb.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Cc: Ewan D. Milne <emilne@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: virtualization@lists.linux-foundation.org
Tested-by: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

No one uses this helper any more, so kill it.

Link: https://lore.kernel.org/r/20210122023317.687987-2-ming.lei@redhat.com
Cc: Omar Sandoval <osandov@fb.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Cc: Ewan D. Milne <emilne@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Tested-by: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

An enabled user-specified exception event that does not clear quickly will
repeatedly cause the handler to run. That could unduly disturb the driver
behaviour being tested or debugged. To prevent that add debugfs file
exception_event_rate_limit_ms. When a exception event happens, it is
disabled, and then after a period of time (default 20ms) the exception
event is enabled again.

Note that if the driver also has that exception event enabled, it will not
be disabled.

Link: https://lore.kernel.org/r/20210209062437.6954-5-adrian.hunter@intel.comAcked-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Allow users to enable specific exception events via debugfs.

The bits enabled by the driver ee_drv_ctrl are separated from the bits
enabled by the user ee_usr_ctrl. The control mask ee_mask_ctrl is the
logical-or of those two. A mutex is needed to ensure that the masks match
what was written to the device.

Link: https://lore.kernel.org/r/20210209062437.6954-4-adrian.hunter@intel.comAcked-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

For readability and completeness, add exception event definitions.

Link: https://lore.kernel.org/r/20210209062437.6954-3-adrian.hunter@intel.comReviewed-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Currently, exception event status can be read from wExceptionEventStatus
attribute (sysfs file attributes/exception_event_status under the UFS host
controller device directory). Polling that attribute to track UFS exception
events is impractical, so add a tracepoint to track exception events for
testing and debugging purposes.

Note, by the time the exception event status is read, the exception event
may have cleared, so the value can be zero - see example below.

Note also, only enabled exception events can be reported. A subsequent
patch adds the ability for users to enable selected exception events via
debugfs.

Example with driver instrumented to enable all exception events:

  # echo 1 > /sys/kernel/debug/tracing/events/ufs/ufshcd_exception_event/enable

  ... do some I/O ...

  # cat /sys/kernel/debug/tracing/trace
  # tracer: nop
  #
  # entries-in-buffer/entries-written: 3/3   #P:5
  #
  #                                _-----=> irqs-off
  #                               / _----=> need-resched
  #                              | / _---=> hardirq/softirq
  #                              || / _--=> preempt-depth
  #                              ||| /     delay
  #           TASK-PID     CPU#  ||||   TIMESTAMP  FUNCTION
  #              | |         |   ||||      |         |
       kworker/2:2-173     [002] ....   731.486419: ufshcd_exception_event: 0000:00:12.5: status 0x0
       kworker/2:2-173     [002] ....   732.608918: ufshcd_exception_event: 0000:00:12.5: status 0x4
       kworker/2:2-173     [002] ....   732.609312: ufshcd_exception_event: 0000:00:12.5: status 0x4

Link: https://lore.kernel.org/r/20210209062437.6954-2-adrian.hunter@intel.comReviewed-by: Avri Altman <avri.altman@wdc.com>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Pull misc fixes from Jens Axboe:
 "Two misc fixes that don't belong in other branches:

   - Fix a regression with ia64 signals, introduced by the
     TIF_NOTIFY_SIGNAL change in 5.11.

   - Fix the current swapfile regression from this merge window"

* tag 'misc-5.12-2021-03-02' of git://git.kernel.dk/linux-block:
  swap: fix swapfile read/write offset
  ia64: don't call handle_signal() unless there's actually a signal queued

We're not factoring in the start of the file for where to write and
read the swapfile, which leads to very unfortunate side effects of
writing where we should not be...

Fixes: 48d15436 ("mm: remove get_swap_bio")
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Sergei and John both reported that ia64 failed to boot in 5.11, and it
was related to signals. Turns out the ia64 signal handling is a bit odd,
it doesn't check the return value of get_signal() for whether there's a
signal to deliver or not. With the introduction of TIF_NOTIFY_SIGNAL,
then task_work could trigger it.

Fix it by only calling handle_signal() if we actually have a real signal
to deliver. This brings it in line with all other archs, too.

Fixes: b269c229 ("ia64: add support for TIF_NOTIFY_SIGNAL")
Reported-by: Sergei Trofimovich <slyich@gmail.com>
Reported-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Tested-by: Sergei Trofimovich <slyich@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Merge branch 'kmap-conversion-for-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull kmap conversion updates from David Sterba:
 "This contains changes regarding kmap API use and eg conversion from
  kmap_atomic to kmap_local_page.

  The API belongs to memory management but to save cross-tree
  dependency headaches we've agreed to take it through the btrfs tree
  because there are some trivial conversions possible, while the rest
  will need some time and getting the easy cases out of the way would be
  convenient.

  The changes can be grouped:

   - function exports, new helpers

   - new VM_BUG_ON for additional verification; it's been discussed if
     it should be VM_BUG_ON or BUG_ON, the former was chosen due to
     performance reasons

   - code replaced by relevant helpers"

[ This is an updated version of a request that originally came in during
  the merge window, but I asked for some updates:

    https://lore.kernel.org/lkml/cover.1614090658.git.dsterba@suse.com/

  which is why this got merge after the merge window closed.  - Linus ]

* 'kmap-conversion-for-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: use copy_highpage() instead of 2 kmaps()
  btrfs: use memcpy_[to|from]_page() and kmap_local_page()
  mm/highmem: Add VM_BUG_ON() to mem*_page() calls
  mm/highmem: Introduce memcpy_page(), memmove_page(), and memset_page()
  mm/highmem: Convert memcpy_[to|from]_page() to kmap_local_page()
  mm/highmem: Lift memcpy_[to|from]_page to core

Pull btrfs fixes from David Sterba:
 "This is the first batch of fixes that usually arrive during the merge
  window code freeze. Regressions and stable material.

  Regressions:

   - fix deadlock in log sync in zoned mode

   - fix bugs in subpage mode still wrongly assuming sectorsize == page
     size

  Fixes:

   - fix missing kunmap of the Q stripe in RAID6

   - block group fixes:
      - fix race between extent freeing/allocation when using bitmaps
      - avoid double put of block group when emptying cluster

   - swapfile fixes:
      - fix swapfile writes vs running scrub
      - fix swapfile activation vs snapshot creation

   - fix stale data exposure after cloning a hole with NO_HOLES enabled

   - remove tree-checker check that does not work in case information
     from other leaves is necessary"

* tag 'for-5.12-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: zoned: fix deadlock on log sync
  btrfs: avoid double put of block group when emptying cluster
  btrfs: fix stale data exposure after cloning a hole with NO_HOLES enabled
  btrfs: tree-checker: do not error out if extent ref hash doesn't match
  btrfs: fix race between swap file activation and snapshot creation
  btrfs: fix race between writes to swap files and scrub
  btrfs: avoid checking for RO block group twice during nocow writeback
  btrfs: fix race between extent freeing/allocation when using bitmaps
  btrfs: make check_compressed_csum() to be subpage compatible
  btrfs: make btrfs_submit_compressed_read() subpage compatible
  btrfs: fix raid6 qstripe kmap

Pull ide fix from Jens Axboe:
 "This is a leftover fix from 5.11, where I forgot to ship it your way"

* tag 'ide-5.11-2021-02-28' of git://git.kernel.dk/linux-block:
  ide/falconide: Fix module unload

Merge tag 'kbuild-fixes-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - Fix UNUSED_KSYMS_WHITELIST for Clang LTO

 - Make -s builds really silent irrespective of V= option

 - Fix build error when SUBLEVEL or PATCHLEVEL is empty

* tag 'kbuild-fixes-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: Fix <linux/version.h> for empty SUBLEVEL or PATCHLEVEL again
  kbuild: make -s option take precedence over V=1
  ia64: remove redundant READELF from arch/ia64/Makefile
  kbuild: do not include include/config/auto.conf from adjust_autoksyms.sh
  kbuild: fix UNUSED_KSYMS_WHITELIST for Clang LTO
  kbuild: lto: add _mcount to list of used symbols

Pull arch/csky updates from Guo Ren:
 "Features:
   - add new memory layout 2.5G(user):1.5G(kernel)
   - add kmemleak support
   - reconstruct VDSO framework: add VDSO with GENERIC_GETTIMEOFDAY,
     GENERIC_TIME_VSYSCALL, HAVE_GENERIC_VDSO
   - add faulthandler_disabled() check
   - support (fix) swapon
   - add (fix) _PAGE_ACCESSED for default pgprot
   - abort uaccess retries upon fatal signal (from arm)

  Fixes and optimizations:
   - fix perf probe failure
   - fix show_regs doesn't contain regs->usp
   - remove custom asm/atomic.h implementation
   - fix barrier design
   - fix futex SMP implementation
   - fix asm/cmpxchg.h with correct ordering barrier
   - cleanup asm/spinlock.h
   - fix PTE global for 2.5:1.5 virtual memory
   - remove prologue of page fault handler in entry.S
   - fix TLB maintenance synchronization problem
   - add show_tlb for CPU_CK860 debug
   - fix FAULT_FLAG_XXX param for handle_mm_fault
   - fix update_mmu_cache called with user io mapping
   - fix do_page_fault parent irq status
   - fix a size determination in gpr_get()
   - pgtable.h: Coding convention
   - kprobe: Fix code in simulate without 'long'
   - fix pfn_valid error with wrong max_mapnr
   - use free_initmem_default() in free_initmem()
   - fix compile error"

* tag 'csky-for-linus-5.12-rc1' of git://github.com/c-sky/csky-linux: (30 commits)
  csky: Fixup compile error
  csky: use free_initmem_default() in free_initmem()
  csky: Fixup pfn_valid error with wrong max_mapnr
  csky: Add VDSO with GENERIC_GETTIMEOFDAY, GENERIC_TIME_VSYSCALL, HAVE_GENERIC_VDSO
  csky: kprobe: Fixup code in simulate without 'long'
  csky: Fixup swapon
  csky: pgtable.h: Coding convention
  csky: Fixup _PAGE_ACCESSED for default pgprot
  csky: remove unused including <linux/version.h>
  csky: Fix a size determination in gpr_get()
  csky: Reconstruct VDSO framework
  csky: mm: abort uaccess retries upon fatal signal
  csky: Sync riscv mm/fault.c for easy maintenance
  csky: Fixup do_page_fault parent irq status
  csky: Add faulthandler_disabled() check
  csky: Fixup update_mmu_cache called with user io mapping
  csky: Fixup FAULT_FLAG_XXX param for handle_mm_fault
  csky: Add show_tlb for CPU_CK860 debug
  csky: Fix TLB maintenance synchronization problem
  csky: Add kmemleak support
  ...

Pull more RISC-V updates from Palmer Dabbelt:
 "A pair of patches that slipped through the cracks:

   - enable CPU hotplug in the defconfigs

   - some cleanups to setup_bootmem

  There's also a single fix for some randconfig build failures:

   - make NUMA depend on SMP"

* tag 'riscv-for-linus-5.12-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: Cleanup setup_bootmem()
  RISC-V: Enable CPU Hotplug in defconfigs
  RISC-V: Make NUMA depend on SMP

Pull more SCSI updates from James Bottomley:
 "This is a few driver updates (iscsi, mpt3sas) that were still in the
  staging queue when the merge window opened (all committed on or before
  8 Feb) and some small bug fixes which came in during the merge window
  (all committed on 22 Feb)"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (30 commits)
  scsi: hpsa: Correct dev cmds outstanding for retried cmds
  scsi: sd: Fix Opal support
  scsi: target: tcmu: Fix memory leak caused by wrong uio usage
  scsi: target: tcmu: Move some functions without code change
  scsi: sd: sd_zbc: Don't pass GFP_NOIO to kvcalloc
  scsi: aic7xxx: Remove unused function pointer typedef ahc_bus_suspend/resume_t
  scsi: bnx2fc: Fix Kconfig warning & CNIC build errors
  scsi: ufs: Fix a duplicate dev quirk number
  scsi: aic79xx: Fix spelling of version
  scsi: target: core: Prevent underflow for service actions
  scsi: target: core: Add cmd length set before cmd complete
  scsi: iscsi: Drop session lock in iscsi_session_chkready()
  scsi: qla4xxx: Use iscsi_is_session_online()
  scsi: libiscsi: Reset max/exp cmdsn during recovery
  scsi: iscsi_tcp: Fix shost can_queue initialization
  scsi: libiscsi: Add helper to calculate max SCSI cmds per session
  scsi: libiscsi: Fix iSCSI host workq destruction
  scsi: libiscsi: Fix iscsi_task use after free()
  scsi: libiscsi: Drop taskqueuelock
  scsi: libiscsi: Fix iscsi_prep_scsi_cmd_pdu() error handling
  ...

Pull more xfs updates from Darrick Wong:
 "The most notable fix here prevents premature reuse of freed metadata
  blocks, and adding the ability to detect accidental nested
  transactions, which are not allowed here.

   - Restore a disused sysctl control knob that was inadvertently
     dropped during the merge window to avoid fstests regressions.

   - Don't speculatively release freed blocks from the busy list until
     we're actually allocating them, which fixes a rare log recovery
     regression.

   - Don't nest transactions when scanning for free space.

   - Add an idiot^Wmaintainer light to detect nested transactions. ;)"

* tag 'xfs-5.12-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: use current->journal_info for detecting transaction recursion
  xfs: don't nest transactions when scanning for eofblocks
  xfs: don't reuse busy extents on extent trim
  xfs: restore speculative_cow_prealloc_lifetime sysctl

Pull more block updates from Jens Axboe:
 "A few stragglers (and one due to me missing it originally), and fixes
  for changes in this merge window mostly. In particular:

   - blktrace cleanups (Chaitanya, Greg)

   - Kill dead blk_pm_* functions (Bart)

   - Fixes for the bio alloc changes (Christoph)

   - Fix for the partition changes (Christoph, Ming)

   - Fix for turning off iopoll with polled IO inflight (Jeffle)

   - nbd disconnect fix (Josef)

   - loop fsync error fix (Mauricio)

   - kyber update depth fix (Yang)

   - max_sectors alignment fix (Mikulas)

   - Add bio_max_segs helper (Matthew)"

* tag 'block-5.12-2021-02-27' of git://git.kernel.dk/linux-block: (21 commits)
  block: Add bio_max_segs
  blktrace: fix documentation for blk_fill_rw()
  block: memory allocations in bounce_clone_bio must not fail
  block: remove the gfp_mask argument to bounce_clone_bio
  block: fix bounce_clone_bio for passthrough bios
  block-crypto-fallback: use a bio_set for splitting bios
  block: fix logging on capacity change
  blk-settings: align max_sectors on "logical_block_size" boundary
  block: reopen the device in blkdev_reread_part
  block: don't skip empty device in in disk_uevent
  blktrace: remove debugfs file dentries from struct blk_trace
  nbd: handle device refs for DESTROY_ON_DISCONNECT properly
  kyber: introduce kyber_depth_updated()
  loop: fix I/O error on fsync() in detached loop devices
  block: fix potential IO hang when turning off io_poll
  block: get rid of the trace rq insert wrapper
  blktrace: fix blk_rq_merge documentation
  blktrace: fix blk_rq_issue documentation
  blktrace: add blk_fill_rwbs documentation comment
  block: remove superfluous param in blk_fill_rwbs()
  ...

Commit 78d3bb44 ("kbuild: Fix <linux/version.h> for empty SUBLEVEL
or PATCHLEVEL") fixed the build error for empty SUBLEVEL or PATCHLEVEL
by prepending a zero.

Commit 9b82f13e ("kbuild: clamp SUBLEVEL to 255") re-introduced
this issue.

This time, we cannot take the same approach because we have C code:

  #define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL)
  #define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)

Replace empty SUBLEVEL/PATCHLEVEL with a zero.

Fixes: 9b82f13e ("kbuild: clamp SUBLEVEL to 255")
Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-and-tested-by: Sasha Levin <sashal@kernel.org>

'make -s' should be really silent. However, 'make -s V=1' prints noisy
log messages from some shell scripts.

Of course, such a combination is odd, but the build system needs to do
the right thing even if a user gives strange input.

If -s is given, KBUILD_VERBOSE should be forced to 0.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

READELF is defined by the top Makefile.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Commit cd195bc4 ("kbuild: split adjust_autoksyms.sh in two parts")
split out the code that needs include/config/auto.conf.

This script no longer needs to include include/config/auto.conf.

Fixes: cd195bc4 ("kbuild: split adjust_autoksyms.sh in two parts")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Commit fbe078d3 ("kbuild: lto: add a default list of used symbols")
does not work as expected if the .config file has already specified
CONFIG_UNUSED_KSYMS_WHITELIST="my/own/white/list" before enabling
CONFIG_LTO_CLANG.

So, the user-supplied whitelist and LTO-specific white list must be
independent of each other.

I refactored the shell script so CONFIG_MODVERSIONS and CONFIG_CLANG_LTO
handle whitelists in the same way.

Fixes: fbe078d3 ("kbuild: lto: add a default list of used symbols")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>

Pull io_uring thread rewrite from Jens Axboe:
 "This converts the io-wq workers to be forked off the tasks in question
  instead of being kernel threads that assume various bits of the
  original task identity.

  This kills > 400 lines of code from io_uring/io-wq, and it's the worst
  part of the code. We've had several bugs in this area, and the worry
  is always that we could be missing some pieces for file types doing
  unusual things (recent /dev/tty example comes to mind, userfaultfd
  reads installing file descriptors is another fun one... - both of
  which need special handling, and I bet it's not the last weird oddity
  we'll find).

  With these identical workers, we can have full confidence that we're
  never missing anything. That, in itself, is a huge win. Outside of
  that, it's also more efficient since we're not wasting space and code
  on tracking state, or switching between different states.

  I'm sure we're going to find little things to patch up after this
  series, but testing has been pretty thorough, from the usual
  regression suite to production. Any issue that may crop up should be
  manageable.

  There's also a nice series of further reductions we can do on top of
  this, but I wanted to get the meat of it out sooner rather than later.
  The general worry here isn't that it's fundamentally broken. Most of
  the little issues we've found over the last week have been related to
  just changes in how thread startup/exit is done, since that's the main
  difference between using kthreads and these kinds of threads. In fact,
  if all goes according to plan, I want to get this into the 5.10 and
  5.11 stable branches as well.

  That said, the changes outside of io_uring/io-wq are:

   - arch setup, simple one-liner to each arch copy_thread()
     implementation.

   - Removal of net and proc restrictions for io_uring, they are no
     longer needed or useful"

* tag 'io_uring-worker.v3-2021-02-25' of git://git.kernel.dk/linux-block: (30 commits)
  io-wq: remove now unused IO_WQ_BIT_ERROR
  io_uring: fix SQPOLL thread handling over exec
  io-wq: improve manager/worker handling over exec
  io_uring: ensure SQPOLL startup is triggered before error shutdown
  io-wq: make buffered file write hashed work map per-ctx
  io-wq: fix race around io_worker grabbing
  io-wq: fix races around manager/worker creation and task exit
  io_uring: ensure io-wq context is always destroyed for tasks
  arch: ensure parisc/powerpc handle PF_IO_WORKER in copy_thread()
  io_uring: cleanup ->user usage
  io-wq: remove nr_process accounting
  io_uring: flag new native workers with IORING_FEAT_NATIVE_WORKERS
  net: remove cmsg restriction from io_uring based send/recvmsg calls
  Revert "proc: don't allow async path resolution of /proc/self components"
  Revert "proc: don't allow async path resolution of /proc/thread-self components"
  io_uring: move SQPOLL thread io-wq forked worker
  io-wq: make io_wq_fork_thread() available to other users
  io-wq: only remove worker from free_list, if it was there
  io_uring: remove io_identity
  io_uring: remove any grabbing of context
  ...

Pull misc vfs updates from Al Viro:
 "Assorted stuff pile - no common topic here"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  whack-a-mole: don't open-code iminor/imajor
  9p: fix misuse of sscanf() in v9fs_stat2inode()
  audit_alloc_mark(): don't open-code ERR_CAST()
  fs/inode.c: make inode_init_always() initialize i_ino to 0
  vfs: don't unnecessarily clone write access for writable fds

Pull i2c fixes from Wolfram Sang:
 "Three more bugfixes and one revert. I accidently applied one patch too
  early"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: exynos5: Preserve high speed master code
  Revert "i2c: i2c-qcom-geni: Add shutdown callback for i2c"
  i2c: designware: Get right data length
  i2c: brcmstb: Fix brcmstd_send_i2c_cmd condition

: error: C++ style comments are not allowed in ISO C90
 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
 ^
error: (this will be reported only once per input file)
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

The existing code is essentially
free_initmem_default()->free_reserved_area() without poisoning.

Note that existing code missed to update the managed page count of the
zone.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Tested-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Guo Ren <guoren@kernel.org>
Signed-off-by: David Hildenbrand <david@redhat.com>