There are two leftover structures from the notification registration
mechanism that has never been released, kill them.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f05f65aebaf8b1b5bf28519a8fdb350e3e7c9ad0.1679924536.git.asml.silence@gmail.com


Signed-off-by: Jens Axboe <axboe@kernel.dk>

Since commit 0654b05e7e65 ("io_uring: One wqe per wq"), we have just a
single io_wqe instance embedded per io_wq.  Drop the extra structure in
favor of accessing struct io_wq directly, cleaning up quite a bit of
dereferences and backpointers.

No functional changes intended.  Tested with liburing's testsuite
and mmtests performance microbenchmarks.  I didn't observe any
performance regressions.

Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Link: https://lore.kernel.org/r/20230322011628.23359-2-krisman@suse.de


Signed-off-by: Jens Axboe <axboe@kernel.dk>

Since we now have a single io_wqe per io_wq instead of per-node, and in
preparation to its removal, move the accounting into the parent
structure.

Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Link: https://lore.kernel.org/r/20230322011628.23359-2-krisman@suse.de


Signed-off-by: Jens Axboe <axboe@kernel.dk>

On at least parisc, we have strict requirements on how we virtually map
an address that is shared between the application and the kernel. On
these platforms, IOU_PBUF_RING_MMAP should be used when setting up a
shared ring buffer for provided buffers. If the application is mapping
these pages and asking the kernel to pin+map them as well, then we have
no control over what virtual address we get in the kernel.

For that case, do a sanity check if SHM_COLOUR is defined, and disallow
the mapping request. The application must fall back to using
IOU_PBUF_RING_MMAP for this case, and liburing will do that transparently
with the set of helpers that it has.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

Add support for KASAN in the alloc_caches (apoll and netmsg_cache).
Thus, if something touches the unused caches, it will raise a KASAN
warning/exception.

It poisons the object when the object is put to the cache, and unpoisons
it when the object is gotten or freed.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Link: https://lore.kernel.org/r/20230223164353.2839177-2-leitao@debian.org


Signed-off-by: Jens Axboe <axboe@kernel.dk>

Having cache entries linked using the hlist format brings no benefit, and
also requires an unnecessary extra pointer address per cache entry.

Use the internal io_wq_work_node single-linked list for the internal
alloc caches (async_msghdr and async_poll)

This is required to be able to use KASAN on cache entries, since we do
not need to touch unused (and poisoned) cache entries when adding more
entries to the list.

Suggested-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20230223164353.2839177-2-leitao@debian.org


Signed-off-by: Jens Axboe <axboe@kernel.dk>

Right now io_wq allocates one io_wqe per NUMA node.  As io_wq is now
bound to a task, the task basically uses only the NUMA local io_wqe, and
almost never changes NUMA nodes, thus, the other wqes are mostly
unused.

Allocate just one io_wqe embedded into io_wq, and uses all possible cpus
(cpu_possible_mask) in the io_wqe->cpumask.

Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20230310201107.4020580-1-leitao@debian.org


Signed-off-by: Jens Axboe <axboe@kernel.dk>

The ring mapped provided buffer rings rely on the application allocating
the memory for the ring, and then the kernel will map it. This generally
works fine, but runs into issues on some architectures where we need
to be able to ensure that the kernel and application virtual address for
the ring play nicely together. This at least impacts architectures that
set SHM_COLOUR, but potentially also anyone setting SHMLBA.

To use this variant of ring provided buffers, the application need not
allocate any memory for the ring. Instead the kernel will do so, and
the allocation must subsequently call mmap(2) on the ring with the
offset set to:

	IORING_OFF_PBUF_RING | (bgid << IORING_OFF_PBUF_SHIFT)

to get a virtual address for the buffer ring. Normally the application
would allocate a suitable piece of memory (and correctly aligned) and
simply pass that in via io_uring_buf_reg.ring_addr and the kernel would
map it.

Outside of the setup differences, the ...

In preparation for allowing flags to be set for registration, rename
the padding and use it for that.

Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Rather than rely on checking buffer_list->buf_pages or ->buf_nr_pages,
add a separate member that tracks if this is a ring mapped provided
buffer list or not.

Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

In preparation for allowing the kernel to allocate the provided buffer
rings and have the application mmap it instead, abstract out the
current method of pinning and mapping the user allocated ring.

No functional changes intended in this patch.

Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Some architectures have memory cache aliasing requirements (e.g. parisc)
if memory is shared between userspace and kernel. This patch fixes the
kernel to return an aliased address when asked by userspace via mmap().

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

io_uring hashes writes to a given file/inode so that it can serialize
them. This is useful if the file system needs exclusive access to the
file to perform the write, as otherwise we end up with a ton of io-wq
threads trying to lock the inode at the same time. This can cause
excessive system time.

But if the file system has flagged that it supports parallel O_DIRECT
writes, then there's no need to serialize the writes. Check for that
through FMODE_DIO_PARALLEL_WRITE and don't hash it if we don't need to.

In a basic test of 8 threads writing to a file on XFS on a gen2 Optane,
with each thread writing in 4k chunks, it improves performance from
~1350K IOPS (or ~5290MiB/sec) to ~1410K IOPS (or ~5500MiB/sec).

Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Some filesystems support multiple threads writing to the same file with
O_DIRECT without requiring exclusive access to it. io_uring can use this
hint to avoid serializing dio writes to this inode, instead allowing them
to run in parallel.

XFS and ext4 both fall into this category, so set the flag for both of
them.

Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull btrfs fixes from David Sterba:

 - scan block devices in non-exclusive mode to avoid temporary mkfs
   failures

 - fix race between quota disable and quota assign ioctls

 - fix deadlock when aborting transaction during relocation with scrub

 - ignore fiemap path cache when there are multiple paths for a node

* tag 'for-6.3-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: ignore fiemap path cache when there are multiple paths for a node
  btrfs: fix deadlock when aborting transaction during relocation with scrub
  btrfs: scan device in non-exclusive mode
  btrfs: fix race between quota disable and quota assign ioctls

This reverts commit a837e516, which broke probing of the venus
driver, at least on the SC7180 SoC HP X2 Chromebook:

  qcom-venus aa00000.video-codec: Adding to iommu group 11
  qcom-venus aa00000.video-codec: non legacy binding
  qcom-venus aa00000.video-codec: failed to reset venus core
  qcom-venus: probe of aa00000.video-codec failed with error -110

Matthias Kaehlcke also reported that the same change caused a regression
in SC7180 and sc7280, that prevents AOSS from entering sleep mode during
system suspend.  So let's revert this commit for now to fix both issues.

Fixes: a837e516

 ("venus: firmware: Correct non-pix start and end addresses")
Reported-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull driver core fixes from Greg KH:
 "Here are three small changes for 6.3-rc5 semi-related to driver core
  stuff:

   - documentation update where we move the security_bugs file to a more
     relevant location.

   - mdt/spi-nor debugfs memory leak fix that's been floating around for
     a long time and acked by the maintainer

   - cacheinfo bugfix for a regression in 6.3-rc1

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

* tag 'driver-core-6.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  cacheinfo: Fix LLC is not exported through sysfs
  Documentation/security-bugs: move from admin-guide/ to process/
  mtd: spi-nor: fix memory leak when using debugfs_lookup()

Pull powerpc fixes from Michael Ellerman:

 - Fix a false positive warning in __pte_needs_flush() (with DEBUG_VM=y)

 - Fix oops when a PF_IO_WORKER thread tries to core dump

 - Don't try to reconfigure VAS when it's disabled

Thanks to Benjamin Gray, Haren Myneni, Jens Axboe, Nathan Lynch, and
Russell Currey.

* tag 'powerpc-6.3-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/pseries/vas: Ignore VAS update for DLPAR if copy/paste is not enabled
  powerpc: Don't try to copy PPR for task with NULL pt_regs
  powerpc/64s: Fix __pte_needs_flush() false positive warning

Pull cifs client fixes from Steve French:
 "Four cifs/smb3 client (reconnect and DFS related) fixes, including two
  for stable:

   - DFS oops fix

   - DFS reconnect recursion fix

   - An SMB1 parallel reconnect fix

   - Trivial dead code removal in smb2_reconnect"

* tag '6.3-rc4-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: get rid of dead check in smb2_reconnect()
  cifs: prevent infinite recursion in CIFSGetDFSRefer()
  cifs: avoid races in parallel reconnects in smb1
  cifs: fix DFS traversal oops without CONFIG_CIFS_DFS_UPCALL

Pull input fixes from Dmitry Torokhov:

 - fixes to ALPS and Focaltech PS/2 drivers dealing with the breakage of
   switching to -funsigned-char

 - quirks to i8042 to better handle Lifebook A574/H and TUXEDO devices

 - a quirk to Goodix touchscreen driver to handle Yoga Book X90F

 - a fix for incorrectly merged patch to xpad game controller driver

* tag 'input-for-v6.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: i8042 - add TUXEDO devices to i8042 quirk tables for partial fix
  Input: alps - fix compatibility with -funsigned-char
  Input: focaltech - use explicitly signed char type
  Input: xpad - fix incorrectly applied patch for MAP_PROFILE_BUTTON
  Input: goodix - add Lenovo Yoga Book X90F to nine_bytes_report DMI table
  Input: i8042 - add quirk for Fujitsu Lifebook A574/H

Pull pin control fixes from Linus Walleij:
 "Some pin control fixes for the v6.3 series.

  The most notable and urgent one is probably the AMD fix which affects
  AMD laptops, found by the Chromium people.

  Summary:

   - Fix up the Kconfig options for MediaTek MT7981

   - Fix the irq domain name in the AT91-PIO4 driver

   - Fix some alternative muxing modes in the Ocelot driver

   - Allocate the GPIO numbers dynamically in the STM32 driver

   - Disable and mask interrupts on resume in the AMD driver

   - Fix a typo in the Qualcomm SM8550 pin control device tree bindings"

* tag 'pinctrl-v6.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
  dt-bindings: pinctrl: qcom,sm8550-lpass-lpi: allow input-enabled and bias-bus-hold
  pinctrl: amd: Disable and mask interrupts on resume
  pinctrl: stm32: use dynamic allocation of GPIO base
  pinctrl: ocelot: Fix alt mode for ocelot
  pinctrl: at91-pio4: fix domain name assignment
  pinctrl: mediatek: fix naming inconsistency
  pinctrl: mediatek: add missing options to PINCTRL_MT7981

Merge tag 'kbuild-fixes-v6.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - Fix linux-headers debian package

 - Fix a merge_config.sh error due to a misspelled variable

 - Fix modversion for 32-bit build machines

* tag 'kbuild-fixes-v6.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  modpost: Fix processing of CRCs on 32-bit build machines
  scripts: merge_config: Fix typo in variable name.
  kbuild: deb-pkg: set version for linux-headers paths

Pull iommu fixes from Joerg Roedel:

 - Maintainer update for S390 IOMMU driver

 - A fix for the set_platform_dma_ops() call-back in the Exynos
   IOMMU driver

 - Intel VT-d fixes from Lu Baolu:
    - Fix a lockdep splat
    - Fix a supplement of the specification
    - Fix a warning in perfmon code

* tag 'iommu-fixes-6.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/vt-d: Fix an IOMMU perfmon warning when CPU hotplug
  iommu/vt-d: Allow zero SAGAW if second-stage not supported
  iommu/vt-d: Remove unnecessary locking in intel_irq_remapping_alloc()
  iommu/exynos: Fix set_platform_dma_ops() callback
  MAINTAINERS: Update s390-iommu driver maintainer information

The runtime suspend/resume functions are only referenced from the
dev_pm_ops, but they use the old SET_RUNTIME_PM_OPS() helper that
requires a __maybe_unused annotation to avoid a warning:

  drivers/media/i2c/imx290.c:1082:12: error: unused function 'imx290_runtime_resume' [-Werror,-Wunused-function]
  static int imx290_runtime_resume(struct device *dev)
             ^
  drivers/media/i2c/imx290.c:1090:12: error: unused function 'imx290_runtime_suspend' [-Werror,-Wunused-function]
  static int imx290_runtime_suspend(struct device *dev)
             ^

Convert this to the new RUNTIME_PM_OPS() helper that so this is not
required.  To improve this further, also use the pm_ptr() helper that
lets the dev_pm_ops get dropped entirely when CONFIG_PM is disabled.

A related mistake happened in the of_match_ptr() macro here, which like
SET_RUNTIME_PM_OPS() requires the match table to be marked as
__maybe_unused, though I could not reproduce building this without
CONFIG_OF.  Remove the of_match_ptr() here as there is no point in
dropping the match table in configurations without CONFIG_OF.

Fixes: 02852c01

 ("media: i2c: imx290: Initialize runtime PM before subdev")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Reported-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull NFS client fixes from Anna Schumaker:

 - Fix shutdown of NFS TCP client sockets

 - Fix hangs when recovering open state after a server reboot

* tag 'nfs-for-6.3-3' of git://git.linux-nfs.org/projects/anna/linux-nfs:
  SUNRPC: fix shutdown of NFS TCP client socket
  NFSv4: Fix hangs when recovering open state after a server reboot

Merge tag 'platform-drivers-x86-v6.3-4' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86

Pull x86 platform driver fixes from Hans de Goede:

 - Fix a regression in ideapad-laptop which caused the touchpad to stop
   working after a suspend/resume on some models

 - One other small fix and three hw-id additions

* tag 'platform-drivers-x86-v6.3-4' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86:
  platform/x86: ideapad-laptop: Stop sending KEY_TOUCHPAD_TOGGLE
  platform/x86: asus-nb-wmi: Add quirk_asus_tablet_mode to other ROG Flow X13 models
  platform/x86: gigabyte-wmi: add support for X570S AORUS ELITE
  platform/x86: gigabyte-wmi: add support for B650 AORUS ELITE AX
  platform/x86/intel/pmc: Alder Lake PCH slp_s0_residency fix

Pull PCI fix from Bjorn Helgaas:

 - Fix DesignWare PORT_LINK_CONTROL setup, which was corrupted when the
   DT "snps,enable-cdm-check" property was present (Yoshihiro Shimoda)

* tag 'pci-v6.3-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci:
  PCI: dwc: Fix PORT_LINK_CONTROL update when CDM check enabled

Merge tag 'regulator-fix-v6.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator

Pull regulator fix from Mark Brown:
 "Deferred probe fix for v6.3.

  This fixes a rarely triggered issue where we would treat probe
  deferral for clocks as a fatal error in the fixed regulator, causing
  it to fail to retry when it should"

* tag 'regulator-fix-v6.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
  regulator: Handle deferred clk

Pull block fixes from Jens Axboe:

 - NVMe pull request via Christoph:
     - Mark Lexar NM760 as IGNORE_DEV_SUBNQN (Juraj Pecigos)
     - Fix a possible UAF when failing to allocate an TCP io queue (Sagi
       Grimberg)

 - MD pull request via Song:
     - Fix a null pointer deference in 6.3-rc (Yu Kuai)

 - uevent partition fix (Alyssa)

* tag 'block-6.3-2023-03-30' of git://git.kernel.dk/linux:
  nvme-tcp: fix a possible UAF when failing to allocate an io queue
  md: fix regression for null-ptr-deference in __md_stop()
  nvme-pci: mark Lexar NM760 as IGNORE_DEV_SUBNQN
  loop: LOOP_CONFIGURE: send uevents for partitions

Pull io_uring fixes from Jens Axboe:

 - Fix a regression with the poll retry, introduced in this merge window
   (me)

 - Fix a regression with the alloc cache not decrementing the member
   count on removal. Also a regression from this merge window (Pavel)

 - Fix race around rsrc node grabbing (Pavel)

* tag 'io_uring-6.3-2023-03-30' of git://git.kernel.dk/linux:
  io_uring: fix poll/netmsg alloc caches
  io_uring/rsrc: fix rogue rsrc node grabbing
  io_uring/poll: clear single/double poll flags on poll arming

Commit 5829f8a8 ("platform/x86: ideapad-laptop: Send
KEY_TOUCHPAD_TOGGLE on some models") made ideapad-laptop send
KEY_TOUCHPAD_TOGGLE when we receive an ACPI notify with VPC event bit 5 set
and the touchpad-state has not been changed by the EC itself already.

This was done under the assumption that this would be good to do to make
the touchpad-toggle hotkey work on newer models where the EC does not
toggle the touchpad on/off itself (because it is not routed through
the PS/2 controller, but uses I2C).

But it turns out that at least some models, e.g. the Yoga 7-15ITL5 the EC
triggers an ACPI notify with VPC event bit 5 set on resume, which would
now cause a spurious KEY_TOUCHPAD_TOGGLE on resume to which the desktop
environment responds by disabling the touchpad in software, breaking
the touchpad (until manually re-enabled) on resume.

It was never confirmed that sending KEY_TOUCHPAD_TOGGLE actually improves
things on new models and at least some new models like the Yoga 7-15ITL5
don't have a touchpad on/off toggle hotkey at all, while still sending
ACPI notify events with VPC event bit 5 set.

So it seems best to revert the change to send KEY_TOUCHPAD_TOGGLE when
receiving an ACPI notify events with VPC event bit 5 and the touchpad
state as reported by the EC has not changed.

Note this is not a full revert the code to cache the last EC touchpad
state is kept to avoid sending spurious KEY_TOUCHPAD_ON / _OFF events
on resume.

Fixes: 5829f8a8 ("platform/x86: ideapad-laptop: Send KEY_TOUCHPAD_TOGGLE on some models")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217234


Cc: stable@vger.kernel.org
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230330194644.64628-1-hdegoede@redhat.com

Make quirk_asus_tablet_mode apply on other ROG Flow X13 devices,
which only affects the GV301Q model before.

Signed-off-by: weiliang1503 <weiliang1503@gmail.com>
Link: https://lore.kernel.org/r/20230330114943.15057-1-weiliang1503@gmail.com


Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

Add "X570S AORUS ELITE" to known working boards

Reported-by: Brandon Nielsen <nielsenb@jetfuse.net>
Link: https://lore.kernel.org/r/20230331014902.7864-1-nielsenb@jetfuse.net


Signed-off-by: Hans de Goede <hdegoede@redhat.com>

Pull thermal control fixes from Rafael Wysocki:
 "These remove two recently added excessive lockdep assertions from the
  sysfs-related thermal code and fix two issues in Intel thermal
  drivers.

  Specifics:

   - Drop two lockdep assertions producing false positive warnings from
     the sysfs-related thermal core code (Rafael Wysocki)

   - Fix handling of two recently added module parameters in the Intel
     powerclamp thermal driver (David Arcari)

   - Fix one more deadlock in the int340x thermal driver (Srinivas
     Pandruvada)"

* tag 'thermal-6.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  thermal: intel: powerclamp: Fix cpumask and max_idle module parameters
  thermal: intel: int340x: processor_thermal: Fix additional deadlock
  thermal: core: Drop excessive lockdep_assert_held() calls

Pull ACPI fix from Rafael Wysocki:
 "Fix a recent regression related to the handling of ACPI notifications
  that made it more likely for ACPI driver callbacks to be invoked in an
  unexpected order and NULL pointers can be dereferenced as a result or
  similar.

  The fix is to modify the global ACPI notification handler so it does
  not invoke driver callbacks at all and allow the device-level
  notification handlers to receive "system" notifications (for the
  drivers that want to receive them)"

* tag 'acpi-6.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI: bus: Rework system-level device notification handling

Pull RISC-V fixes from Palmer Dabbelt:

 - A fix for FPU probing in XIP kernels

 - Always enable the alternative framework for non-XIP kernels

* tag 'riscv-for-linus-6.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  RISC-V: always select RISCV_ALTERNATIVE for non-xip kernels
  RISC-V: add non-alternative fallback for riscv_has_extension_[un]likely()

Pull MIPS fix from Thomas Bogendoerfer:
 "Fix to avoid crash on BCM6358 platforms"

* tag 'mips-fixes_6.3_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  mips: bmips: BCM6358: disable RAC flush for TP1

Merge Intel thermal driver fixes for 6.3-rc5:

 - Fix handling of two recently added module parameters in the Intel
   powerclamp thermal driver (David Arcari).

 - Fix one more deadlock in the int340x thermal driver (Srinivas
   Pandruvada).

* thermal-intel-fixes:
  thermal: intel: powerclamp: Fix cpumask and max_idle module parameters
  thermal: intel: int340x: processor_thermal: Fix additional deadlock

A warning can be triggered when hotplug CPU 0.
$ echo 0 > /sys/devices/system/cpu/cpu0/online

 ------------[ cut here ]------------
 Voluntary context switch within RCU read-side critical section!
 WARNING: CPU: 0 PID: 19 at kernel/rcu/tree_plugin.h:318
          rcu_note_context_switch+0x4f4/0x580
 RIP: 0010:rcu_note_context_switch+0x4f4/0x580
 Call Trace:
  <TASK>
  ? perf_event_update_userpage+0x104/0x150
  __schedule+0x8d/0x960
  ? perf_event_set_state.part.82+0x11/0x50
  schedule+0x44/0xb0
  schedule_timeout+0x226/0x310
  ? __perf_event_disable+0x64/0x1a0
  ? _raw_spin_unlock+0x14/0x30
  wait_for_completion+0x94/0x130
  __wait_rcu_gp+0x108/0x130
  synchronize_rcu+0x67/0x70
  ? invoke_rcu_core+0xb0/0xb0
  ? __bpf_trace_rcu_stall_warning+0x10/0x10
  perf_pmu_migrate_context+0x121/0x370
  iommu_pmu_cpu_offline+0x6a/0xa0
  ? iommu_pmu_del+0x1e0/0x1e0
  cpuhp_invoke_callback+0x129/0x510
  cpuhp_thread_fun+0x94/0x150
  smpboot_thread_fn+0x183/0x220
  ? sort_range+0x20/0x20
  kthread+0xe6/0x110
  ? kthread_complete_and_exit+0x20/0x20
  ret_from_fork+0x1f/0x30
  </TASK>
 ---[ end trace 0000000000000000 ]---

The synchronize_rcu() will be invoked in the perf_pmu_migrate_context(),
when migrating a PMU to a new CPU. However, the current for_each_iommu()
is within RCU read-side critical section.

Two methods were considered to fix the issue.
- Use the dmar_global_lock to replace the RCU read lock when going
  through the drhd list. But it triggers a lockdep warning.
- Use the cpuhp_setup_state_multi() to set up a dedicated state for each
  IOMMU PMU. The lock can be avoided.

The latter method is implemented in this patch. Since each IOMMU PMU has
a dedicated state, add cpuhp_node and cpu in struct iommu_pmu to track
the state. The state can be dynamically allocated now. Remove the
CPUHP_AP_PERF_X86_IOMMU_PERF_ONLINE.

Fixes: 46284c6c

 ("iommu/vt-d: Support cpumask for IOMMU perfmon")
Reported-by: Ammy Yi <ammy.yi@intel.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Link: https://lore.kernel.org/r/20230328182028.1366416-1-kan.liang@linux.intel.com


Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20230329134721.469447-4-baolu.lu@linux.intel.com


Signed-off-by: Joerg Roedel <jroedel@suse.de>