Convert pwm-mtk-disp.txt to mediatek,pwm-disp.yaml format as suggested
by maintainer.
Signed-off-by: Xinlei Lee <xinlei.lee@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Miles Chen <miles.chen@mediatek.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

To eventually get rid of all legacy drivers convert this driver to the
modern world implementing .apply().

This fixes a small issue in clps711x_get_duty() en passant: the
multiplication v * 0xf might have overflown.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

The reg member of struct raspberrypi_pwm_prop is a little endian 32 bit
quantity. Explicitly convert the (native endian) value to little endian
on assignment as is already done in raspberrypi_pwm_set_property().

This fixes the following sparse warning:

	drivers/pwm/pwm-raspberrypi-poe.c:69:24: warning: incorrect type in initializer (different base types)
	drivers/pwm/pwm-raspberrypi-poe.c:69:24:    expected restricted __le32 [usertype] reg
	drivers/pwm/pwm-raspberrypi-poe.c:69:24:    got unsigned int [usertype] reg

Fixes: 79caa362 ("pwm: Add Raspberry Pi Firmware based PWM bus")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

The array atmel_tcb_divisors is not supposed to be used outside of the
driver, so make it static.

This fixes a sparse warning:

	drivers/pwm/pwm-atmel-tcb.c:64:10: warning: symbol 'atmel_tcb_divisors' was not declared. Should it be static?
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

pwmchip_add() unconditionally assigns the base ID dynamically. Commit
f9a8ee8c ("pwm: Always allocate PWM chip base ID dynamically")
dropped all base assignment from drivers under drivers/pwm/. It missed
this driver. Fix that.

Fixes: f9a8ee8c ("pwm: Always allocate PWM chip base ID dynamically")
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

To eventually get rid of all legacy drivers convert this driver to the
modern world implementing .apply().
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

The hardware only supports periods <= 1.6 ms and if a bigger period is
requested it is clamped to 1.6 ms. In this case duty_cycle might be bigger
than 1.6 ms and then the duty cycle register is written with a value
bigger than LP3943_MAX_DUTY. So clamp duty_cycle accordingly.

Fixes: af66b3c0 ("pwm: Add LP3943 PWM driver")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Add Sunplus SoC SP7021 PWM Driver
Signed-off-by: Hammer Hsieh <hammerh0314@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Add bindings doc for Sunplus SoC SP7021 PWM Driver
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Hammer Hsieh <hammerh0314@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Add compatible strings list for SAMA7G5.
Signed-off-by: Sergiu Moga <sergiu.moga@microchip.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Convert PWM binding for Atmel/Microchip SoCs to Device Tree Schema
format.
Signed-off-by: Sergiu Moga <sergiu.moga@microchip.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

This adds PWM support for Xilinx LogiCORE IP AXI soft timers commonly
found on Xilinx FPGAs. At the moment clock control is very basic: we
just enable the clock during probe and pin the frequency. In the future,
someone could add support for disabling the clock when not in use.

Some common code has been specially demarcated. While currently only
used by the PWM driver, it is anticipated that it may be split off in
the future to be used by the timer driver as well.

This driver was written with reference to Xilinx DS764 for v1.03.a [1].

[1] https://www.xilinx.com/support/documentation/ip_documentation/axi_timer/v1_03_a/axi_timer_ds764.pdfSigned-off-by: Sean Anderson <sean.anderson@seco.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

This adds a binding for the Xilinx LogiCORE IP AXI Timer. This device is a
"soft" block, so it has some parameters which would not be configurable in
most hardware. This binding is usually automatically generated by Xilinx's
tools, so the names and values of some properties should be kept as they
are, if possible. In addition, this binding is already in the kernel at
arch/microblaze/boot/dts/system.dts, and in user software such as QEMU.

The existing driver uses the clock-frequency property, or alternatively the
/cpus/timebase-frequency property as its frequency input. Because these
properties are deprecated, they have not been included with this schema.
All new bindings should use the clocks/clock-names properties to specify
the parent clock.

Because we need to init timer devices so early in boot, we determine if we
should use the PWM driver or the clocksource/clockevent driver by the
presence/absence, respectively, of #pwm-cells. Because both counters are
used by the PWM, there is no need for a separate property specifying which
counters are to be used for the PWM.
Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Per-channel data is tracked using struct pwm_device::chip_data and
struct atmel_tcb_pwm_chip::pwms[]. Simplify by using the latter
consistently.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

This fixes a problem that was supposed to be addressed by commit
6eefb79d ("pwm: sun4i: Remove erroneous else branch") - backlight
could not be switched off on some Allwinner A20.  The commit was
correct, but was not a reliable fix for the problem, which was timing
related.

The real problem for the backlight switching problem was that sleeping
for a full period did not work, because delay_us is always zero.

It is zero because the period (plus 1 microsecond) is rounded down to
the next "jiffies", but the period is less than one jiffy.

On my Cubieboard 2, the period is 5ms, and 1 jiffy (at the default
HZ=100) is 10ms, so nsecs_to_jiffies(10ms+1us)=0.

The roundtrip from nanoseconds to jiffies and back to microseconds is
an unnecessary loss of precision; always rounding down (via
nsecs_to_jiffies()) then causes the breakage.

This patch eliminates this roundtrip, and directly converts from
nanoseconds to microseconds (for usleep_range()), using
DIV_ROUND_UP_ULL() to force rounding up.  This way, the sleep time is
never zero, and after the sleep, we are guaranteed to be in a
different period, and the device is ready for another control command
for sure.
Signed-off-by: Max Kellermann <max.kellermann@gmail.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Basically this code did "jiffies + period - jiffies", and we can
simply eliminate the "jiffies" time stamp here.
Signed-off-by: Max Kellermann <max.kellermann@gmail.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Its value is calculated in sun4i_pwm_apply() and is used only there.
Signed-off-by: Max Kellermann <max.kellermann@gmail.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Pull xen fixlet from Juergen Gross:
 "A single cleanup patch for the Xen balloon driver"

* tag 'for-linus-5.18-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/balloon: don't use PV mode extra memory for zone device allocations

Pull x86 fixes from Thomas Gleixner:
 "Two x86 fixes related to TSX:

   - Use either MSR_TSX_FORCE_ABORT or MSR_IA32_TSX_CTRL to disable TSX
     to cover all CPUs which allow to disable it.

   - Disable TSX development mode at boot so that a microcode update
     which provides TSX development mode does not suddenly make the
     system vulnerable to TSX Asynchronous Abort"

* tag 'x86-urgent-2022-04-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/tsx: Disable TSX development mode at boot
  x86/tsx: Use MSR_TSX_CTRL to clear CPUID bits

Pull timer fixes from Thomas Gleixner:
 "A small set of fixes for the timers core:

   - Fix the warning condition in __run_timers() which does not take
     into account that a CPU base (especially the deferrable base) never
     has a timer armed on it and therefore the next_expiry value can
     become stale.

   - Replace a WARN_ON() in the NOHZ code with a WARN_ON_ONCE() to
     prevent endless spam in dmesg.

   - Remove the double star from a comment which is not meant to be in
     kernel-doc format"

* tag 'timers-urgent-2022-04-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tick/sched: Fix non-kernel-doc comment
  tick/nohz: Use WARN_ON_ONCE() to prevent console saturation
  timers: Fix warning condition in __run_timers()

Pull SMP fixes from Thomas Gleixner:
 "Two fixes for the SMP core:

   - Make the warning condition in flush_smp_call_function_queue()
     correct, which checked a just emptied list head for being empty
     instead of validating that there was no pending entry on the
     offlined CPU at all.

   - The @cpu member of struct cpuhp_cpu_state is initialized when the
     CPU hotplug thread for the upcoming CPU is created. That's too late
     because the creation of the thread can fail and then the following
     rollback operates on CPU0. Get rid of the CPU member and hand the
     CPU number to the involved functions directly"

* tag 'smp-urgent-2022-04-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  cpu/hotplug: Remove the 'cpu' member of cpuhp_cpu_state
  smp: Fix offline cpu check in flush_smp_call_function_queue()

Pull irq fix from Thomas Gleixner:
 "A single fix for the interrupt affinity spreading logic to take into
  account that there can be an imbalance between present and possible
  CPUs, which causes already assigned bits to be overwritten"

* tag 'irq-urgent-2022-04-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq/affinity: Consider that CPUs on nodes can be unbalanced

Pull power supply fixes from Sebastian Reichel:

 - Fix a regression with battery data failing to load from DT

* tag 'for-v5.18-rc' of git://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-power-supply:
  power: supply: Reset err after not finding static battery
  power: supply: samsung-sdi-battery: Add missing charge restart voltages

Pull i2c fixes from Wolfram Sang:
 "Regular set of fixes for drivers and the dev-interface"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: ismt: Fix undefined behavior due to shift overflowing the constant
  i2c: dev: Force case user pointers in compat_i2cdev_ioctl()
  i2c: dev: check return value when calling dev_set_name()
  i2c: qcom-geni: Use dev_err_probe() for GPI DMA error
  i2c: imx: Implement errata ERR007805 or e7805 bus frequency limit
  i2c: pasemi: Wait for write xfers to finish

Pull devicetree fixes from Rob Herring:

 - Fix scalar property schemas with array constraints

 - Fix 'enum' lists with duplicate entries

 - Fix incomplete if/then/else schemas

 - Add Renesas RZ/V2L SoC support to Mali Bifrost binding

 - Maintainers update for Marvell irqchip

* tag 'devicetree-fixes-for-5.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  dt-bindings: display: panel-timing: Define a single type for properties
  dt-bindings: Fix array constraints on scalar properties
  dt-bindings: gpu: mali-bifrost: Document RZ/V2L SoC
  dt-bindings: net: snps: remove duplicate name
  dt-bindings: Fix 'enum' lists with duplicate entries
  dt-bindings: irqchip: mrvl,intc: refresh maintainers
  dt-bindings: Fix incomplete if/then/else schemas
  dt-bindings: power: renesas,apmu: Fix cpus property limits
  dt-bindings: extcon: maxim,max77843: fix ports type

Pull gpio fixes from Bartosz Golaszewski:
 "A single fix for gpio-sim and two patches for GPIO ACPI pulled from
  Andy:

   - fix the set/get_multiple() callbacks in gpio-sim

   - use correct format characters in gpiolib-acpi

   - use an unsigned type for pins in gpiolib-acpi"

* tag 'gpio-fixes-for-v5.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
  gpio: sim: fix setting and getting multiple lines
  gpiolib: acpi: Convert type for pin to be unsigned
  gpiolib: acpi: use correct format characters

Pull ARM SoC fixes from Arnd Bergmann:
 "There are a number of SoC bugfixes that came in since the merge
  window, and more of them are already pending.

  This batch includes:

   - A boot time regression fix for davinci that triggered on
     multi_v5_defconfig when booting any platform

   - Defconfig updates to address removed features, changed symbol names
     or dependencies, for gemini, ux500, and pxa

   - Email address changes for Krzysztof Kozlowski

   - Build warning fixes for ep93xx and iop32x

   - Devicetree warning fixes across many platforms

   - Minor bugfixes for the reset controller, memory controller and SCMI
     firmware subsystems plus the versatile-express board"

* tag 'soc-fixes-5.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (34 commits)
  ARM: config: Update Gemini defconfig
  arm64: dts: qcom/sdm845-shift-axolotl: Fix boolean properties with values
  ARM: dts: align SPI NOR node name with dtschema
  ARM: dts: Fix more boolean properties with values
  arm/arm64: dts: qcom: Fix boolean properties with values
  arm64: dts: imx: Fix imx8*-var-som touchscreen property sizes
  arm: dts: imx: Fix boolean properties with values
  arm64: dts: tegra: Fix boolean properties with values
  arm: dts: at91: Fix boolean properties with values
  arm: configs: imote2: Drop defconfig as board support dropped.
  ep93xx: clock: Don't use plain integer as NULL pointer
  ep93xx: clock: Fix UAF in ep93xx_clk_register_gate()
  ARM: vexpress/spc: Fix all the kernel-doc build warnings
  ARM: vexpress/spc: Fix kernel-doc build warning for ve_spc_cpu_in_wfi
  ARM: config: u8500: Re-enable AB8500 battery charging
  ARM: config: u8500: Add some common hardware
  memory: fsl_ifc: populate child nodes of buses and mfd devices
  ARM: config: Refresh U8500 defconfig
  firmware: arm_scmi: Fix sparse warnings in OPTEE transport driver
  firmware: arm_scmi: Replace zero-length array with flexible-array member
  ...

Pull random number generator fixes from Jason Donenfeld:

 - Per your suggestion, random reads now won't fail if there's a page
   fault after some non-zero amount of data has been read, which makes
   the behavior consistent with all other reads in the kernel.

 - Rather than an inconsistent mix of random_get_entropy() returning an
   unsigned long or a cycles_t, now it just returns an unsigned long.

 - A memcpy() was replaced with an memmove(), because the addresses are
   sometimes overlapping. In practice the destination is always before
   the source, so not really an issue, but better to be correct than
   not.

* tag 'random-5.18-rc3-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random:
  random: use memmove instead of memcpy for remaining 32 bytes
  random: make random_get_entropy() return an unsigned long
  random: allow partial reads if later user copies fail

Pull SCSI fixes from James Bottomley:
 "13 fixes, all in drivers.

  The most extensive changes are in the iscsi series (affecting drivers
  qedi, cxgbi and bnx2i), the next most is scsi_debug, but that's just a
  simple revert and then minor updates to pm80xx"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: iscsi: MAINTAINERS: Add Mike Christie as co-maintainer
  scsi: qedi: Fix failed disconnect handling
  scsi: iscsi: Fix NOP handling during conn recovery
  scsi: iscsi: Merge suspend fields
  scsi: iscsi: Fix unbound endpoint error handling
  scsi: iscsi: Fix conn cleanup and stop race during iscsid restart
  scsi: iscsi: Fix endpoint reuse regression
  scsi: iscsi: Release endpoint ID when its freed
  scsi: iscsi: Fix offload conn cleanup when iscsid restarts
  scsi: iscsi: Move iscsi_ep_disconnect()
  scsi: pm80xx: Enable upper inbound, outbound queues
  scsi: pm80xx: Mask and unmask upper interrupt vectors 32-63
  Revert "scsi: scsi_debug: Address races following module load"

Merge tag 'intel-gpio-v5.18-2' of gitolite.kernel.org:pub/scm/linux/kernel/git/andy/linux-gpio-intel into gpio/for-current

intel-gpio for v5.18-2

* Couple of fixes related to handling unsigned value of the pin from ACPI

gpiolib:
 -  acpi: Convert type for pin to be unsigned
 -  acpi: use correct format characters

Pull dma-mapping fix from Christoph Hellwig:

 - avoid a double memory copy for swiotlb (Chao Gao)

* tag 'dma-mapping-5.18-2' of git://git.infradead.org/users/hch/dma-mapping:
  dma-direct: avoid redundant memory sync for swiotlb

In order to immediately overwrite the old key on the stack, before
servicing a userspace request for bytes, we use the remaining 32 bytes
of block 0 as the key. This means moving indices 8,9,a,b,c,d,e,f ->
4,5,6,7,8,9,a,b. Since 4 < 8, for the kernel implementations of
memcpy(), this doesn't actually appear to be a problem in practice. But
relying on that characteristic seems a bit brittle. So let's change that
to a proper memmove(), which is the by-the-books way of handling
overlapping memory copies.
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

Merge misc fixes from Andrew Morton:
 "14 patches.

  Subsystems affected by this patch series: MAINTAINERS, binfmt, and
  mm (tmpfs, secretmem, kasan, kfence, pagealloc, zram, compaction,
  hugetlb, vmalloc, and kmemleak)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm: kmemleak: take a full lowmem check in kmemleak_*_phys()
  mm/vmalloc: fix spinning drain_vmap_work after reading from /proc/vmcore
  revert "fs/binfmt_elf: use PT_LOAD p_align values for static PIE"
  revert "fs/binfmt_elf: fix PT_LOAD p_align values for loaders"
  hugetlb: do not demote poisoned hugetlb pages
  mm: compaction: fix compiler warning when CONFIG_COMPACTION=n
  mm: fix unexpected zeroed page mapping with zram swap
  mm, page_alloc: fix build_zonerefs_node()
  mm, kfence: support kmem_dump_obj() for KFENCE objects
  kasan: fix hw tags enablement when KUNIT tests are disabled
  irq_work: use kasan_record_aux_stack_noalloc() record callstack
  mm/secretmem: fix panic when growing a memfd_secret
  tmpfs: fix regressions from wider use of ZERO_PAGE
  MAINTAINERS: Broadcom internal lists aren't maintainers

Merge tag 'for-5.18/dm-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

 - Fix memory corruption in DM integrity target when tag_size is less
   than digest size.

 - Fix DM multipath's historical-service-time path selector to not use
   sched_clock() and ktime_get_ns(); only use ktime_get_ns().

 - Fix dm_io->orig_bio NULL pointer dereference in dm_zone_map_bio() due
   to 5.18 changes that overlooked DM zone's use of ->orig_bio

 - Fix for regression that broke the use of dm_accept_partial_bio() for
   "abnormal" IO (e.g. WRITE ZEROES) that does not need duplicate bios

 - Fix DM's issuing of empty flush bio so that it's size is 0.

* tag 'for-5.18/dm-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm: fix bio length of empty flush
  dm: allow dm_accept_partial_bio() for dm_io without duplicate bios
  dm zone: fix NULL pointer dereference in dm_zone_map_bio
  dm mpath: only use ktime_get_ns() in historical selector
  dm integrity: fix memory corruption when tag_size is less than digest size

The kmemleak_*_phys() apis do not check the address for lowmem's min
boundary, while the caller may pass an address below lowmem, which will
trigger an oops:

  # echo scan > /sys/kernel/debug/kmemleak
  Unable to handle kernel paging request at virtual address ff5fffffffe00000
  Oops [#1]
  Modules linked in:
  CPU: 2 PID: 134 Comm: bash Not tainted 5.18.0-rc1-next-20220407 #33
  Hardware name: riscv-virtio,qemu (DT)
  epc : scan_block+0x74/0x15c
   ra : scan_block+0x72/0x15c
  epc : ffffffff801e5806 ra : ffffffff801e5804 sp : ff200000104abc30
   gp : ffffffff815cd4e8 tp : ff60000004cfa340 t0 : 0000000000000200
   t1 : 00aaaaaac23954cc t2 : 00000000000003ff s0 : ff200000104abc90
   s1 : ffffffff81b0ff28 a0 : 0000000000000000 a1 : ff5fffffffe01000
   a2 : ffffffff81b0ff28 a3 : 0000000000000002 a4 : 0000000000000001
   a5 : 0000000000000000 a6 : ff200000104abd7c a7 : 0000000000000005
   s2 : ff5fffffffe00ff9 s3 : ffffffff815cd998 s4 : ffffffff815d0e90
   s5 : ffffffff81b0ff28 s6 : 0000000000000020 s7 : ffffffff815d0eb0
   s8 : ffffffffffffffff s9 : ff5fffffffe00000 s10: ff5fffffffe01000
   s11: 0000000000000022 t3 : 00ffffffaa17db4c t4 : 000000000000000f
   t5 : 0000000000000001 t6 : 0000000000000000
  status: 0000000000000100 badaddr: ff5fffffffe00000 cause: 000000000000000d
    scan_gray_list+0x12e/0x1a6
    kmemleak_scan+0x2aa/0x57e
    kmemleak_write+0x32a/0x40c
    full_proxy_write+0x56/0x82
    vfs_write+0xa6/0x2a6
    ksys_write+0x6c/0xe2
    sys_write+0x22/0x2a
    ret_from_syscall+0x0/0x2

The callers may not quite know the actual address they pass(e.g. from
devicetree).  So the kmemleak_*_phys() apis should guarantee the address
they finally use is in lowmem range, so check the address for lowmem's
min boundary.

Link: https://lkml.kernel.org/r/20220413122925.33856-1-patrick.wang.shcn@gmail.comSigned-off-by: Patrick Wang <patrick.wang.shcn@gmail.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 3ee48b6a ("mm, x86: Saving vmcore with non-lazy freeing of
vmas") introduced set_iounmap_nonlazy(), which sets vmap_lazy_nr to
lazy_max_pages() + 1, ensuring that any future vunmaps() immediately
purge the vmap areas instead of doing it lazily.

Commit 690467c8 ("mm/vmalloc: Move draining areas out of caller
context") moved the purging from the vunmap() caller to a worker thread.
Unfortunately, set_iounmap_nonlazy() can cause the worker thread to spin
(possibly forever).  For example, consider the following scenario:

 1. Thread reads from /proc/vmcore. This eventually calls
    __copy_oldmem_page() -> set_iounmap_nonlazy(), which sets
    vmap_lazy_nr to lazy_max_pages() + 1.

 2. Then it calls free_vmap_area_noflush() (via iounmap()), which adds 2
    pages (one page plus the guard page) to the purge list and
    vmap_lazy_nr. vmap_lazy_nr is now lazy_max_pages() + 3, so the
    drain_vmap_work is scheduled.

 3. Thread returns from the kernel and is scheduled out.

 4. Worker thread is scheduled in and calls drain_vmap_area_work(). It
    frees the 2 pages on the purge list. vmap_lazy_nr is now
    lazy_max_pages() + 1.

 5. This is still over the threshold, so it tries to purge areas again,
    but doesn't find anything.

 6. Repeat 5.

If the system is running with only one CPU (which is typicial for kdump)
and preemption is disabled, then this will never make forward progress:
there aren't any more pages to purge, so it hangs.  If there is more
than one CPU or preemption is enabled, then the worker thread will spin
forever in the background.  (Note that if there were already pages to be
purged at the time that set_iounmap_nonlazy() was called, this bug is
avoided.)

This can be reproduced with anything that reads from /proc/vmcore
multiple times.  E.g., vmcore-dmesg /proc/vmcore.

It turns out that improvements to vmap() over the years have obsoleted
the need for this "optimization".  I benchmarked `dd if=/proc/vmcore
of=/dev/null` with 4k and 1M read sizes on a system with a 32GB vmcore.
The test was run on 5.17, 5.18-rc1 with a fix that avoided the hang, and
5.18-rc1 with set_iounmap_nonlazy() removed entirely:

    |5.17  |5.18+fix|5.18+removal
  4k|40.86s|  40.09s|      26.73s
  1M|24.47s|  23.98s|      21.84s

The removal was the fastest (by a wide margin with 4k reads).  This
patch removes set_iounmap_nonlazy().

Link: https://lkml.kernel.org/r/52f819991051f9b865e9ce25605509bfdbacadcd.1649277321.git.osandov@fb.com
Fixes: 690467c8  ("mm/vmalloc: Move draining areas out of caller context")
Signed-off-by: Omar Sandoval <osandov@fb.com>
Acked-by: Chris Down <chris@chrisdown.name>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Despite Mike's attempted fix (925346c1), regressions reports
continue:

  https://lore.kernel.org/lkml/cb5b81bd-9882-e5dc-cd22-54bdbaaefbbc@leemhuis.info/
  https://bugzilla.kernel.org/show_bug.cgi?id=215720
  https://lkml.kernel.org/r/b685f3d0-da34-531d-1aa9-479accd3e21b@leemhuis.info

So revert this patch.

Fixes: 9630f0d6 ("fs/binfmt_elf: use PT_LOAD p_align values for static PIE")
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Chris Kennelly <ckennelly@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Fangrui Song <maskray@google.com>
Cc: H.J. Lu <hjl.tools@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Sandeep Patil <sspatil@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 925346c1 ("fs/binfmt_elf: fix PT_LOAD p_align values for
loaders") was an attempt to fix regressions due to 9630f0d6
("fs/binfmt_elf: use PT_LOAD p_align values for static PIE").

But regressionss continue to be reported:

  https://lore.kernel.org/lkml/cb5b81bd-9882-e5dc-cd22-54bdbaaefbbc@leemhuis.info/
  https://bugzilla.kernel.org/show_bug.cgi?id=215720
  https://lkml.kernel.org/r/b685f3d0-da34-531d-1aa9-479accd3e21b@leemhuis.info

This patch reverts the fix, so the original can also be reverted.

Fixes: 925346c1 ("fs/binfmt_elf: fix PT_LOAD p_align values for loaders")
Cc: H.J. Lu <hjl.tools@gmail.com>
Cc: Chris Kennelly <ckennelly@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sandeep Patil <sspatil@google.com>
Cc: Fangrui Song <maskray@google.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

It is possible for poisoned hugetlb pages to reside on the free lists.
The huge page allocation routines which dequeue entries from the free
lists make a point of avoiding poisoned pages.  There is no such check
and avoidance in the demote code path.

If a hugetlb page on the is on a free list, poison will only be set in
the head page rather then the page with the actual error.  If such a
page is demoted, then the poison flag may follow the wrong page.  A page
without error could have poison set, and a page with poison could not
have the flag set.

Check for poison before attempting to demote a hugetlb page.  Also,
return -EBUSY to the caller if only poisoned pages are on the free list.

Link: https://lkml.kernel.org/r/20220307215707.50916-1-mike.kravetz@oracle.com
Fixes: 8531fc6f ("hugetlb: add hugetlb demote page support")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>