In 'struct lp50xx', the 'num_of_banked_leds' field is only written and
is never used. Moreover, storing such an information in the 'priv'
structure looks pointless, so remove it.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/a0d472ff587d13a2b91ec32c8776061019caab6a.1714324500.git.christophe.jaillet@wanadoo.frSigned-off-by: Lee Jones <lee@kernel.org>

In 'struct lp50xx_led', the 'bank_modules' field is unused. Remove it.

Found with cppcheck, unusedStructMember.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/bc2e5e57b93ca0a33bcc84e9bdc89f26fc8f6d57.1714324500.git.christophe.jaillet@wanadoo.frSigned-off-by: Lee Jones <lee@kernel.org>

In 'struct aat1290_led', the 'torch_brightness' field is unused. Remove it.

Found with cppcheck, unusedStructMember.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/f7c8c22242544b11e95d9a77d7d0ea17f5a24fd5.1714318454.git.christophe.jaillet@wanadoo.frSigned-off-by: Lee Jones <lee@kernel.org>

match_string() returns the array index of a matching string.
Use it instead of the open-coded implementation.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/20240426152515.872917-1-andriy.shevchenko@linux.intel.comSigned-off-by: Lee Jones <lee@kernel.org>

On stm32mp1xx based machines (and others) a PWM consumer has to disable
the PWM because an enabled PWM refuses to suspend. So check the
LED_SUSPENDED flag and depending on that set the .enabled property.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=218559
Fixes: 76fe464c ("leds: pwm: Don't disable the PWM when the LED should be off")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20240417153846.271751-2-u.kleine-koenig@pengutronix.deSigned-off-by: Lee Jones <lee@kernel.org>

Currently, led pattern trigger uses timer_list to schedule brightness
changing. As we know from timer_list API [1], it's not accurate to
milliseconds and depends on HZ granularity.

Example:
"0 10 0 0 50 10 50 0 100 10 100 0 150 10 150 0 200 10 200 0 250 10 250 0",
we expect it to be 60ms long, but it can actually be up to ~120ms
(add ~10ms for each pattern when HZ == 100).

But sometimes, userspace needs time accurate led patterns to make sure
that pattern will be executed during expected time slot.
To achieve this goal the patch introduces optional hrtimer usage for
led trigger pattern, because hrtimer is microseconds accurate timer.

[1]: kernel/time/timer.c#L104
Signed-off-by: Martin Kurbanov <mmkurbanov@salutedevices.com>
Link: https://lore.kernel.org/r/20240416201847.357099-1-mmkurbanov@salutedevices.comSigned-off-by: Lee Jones <lee@kernel.org>

V4L2 will disable strobe mode of the LED device when enable torch mode,
but this logic will conflict with the "priv->fled_torch_used"
in "mt6360_strobe_set()". So after enabling torch mode of the first
LED, the second LED will not be able to enable torch mode correctly.

Therefore, at the beginning of "mt6360_strobe_set()", check whether the
state of the upcoming change and the current LED device state are the
same, so as to avoid the above problem.
Signed-off-by: ChiaEn Wu <chiaen_wu@richtek.com>
Link: https://lore.kernel.org/r/28FE6F1712799128000.chiaen_wu@richtek.comSigned-off-by: Lee Jones <lee@kernel.org>

Update leds-qcom-lpg binding to support PMI8950 PWM.
Signed-off-by: Gianluca Boiano <morf3089@gmail.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20240402-pmi8950-pwm-support-v1-3-1a66899eeeb3@gmail.comSigned-off-by: Lee Jones <lee@kernel.org>

The PMI8950 PMIC contains 1 PWM channel
Signed-off-by: Gianluca Boiano <morf3089@gmail.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20240402-pmi8950-pwm-support-v1-1-1a66899eeeb3@gmail.comSigned-off-by: Lee Jones <lee@kernel.org>

Building with W=1 shows a warning about an unused dmi_system_id table:

drivers/leds/leds-apu.c:85:35: error: 'apu_led_dmi_table' defined but not used [-Werror=unused-const-variable=]
   85 | static const struct dmi_system_id apu_led_dmi_table[] __initconst = {

Since the current version doesn't even do anything about the different
implementations but only checks the type of system, just drop the
custom lookup logic and call dmi_check_system() using the table itself.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20240403080702.3509288-16-arnd@kernel.orgSigned-off-by: Lee Jones <lee@kernel.org>

led_trigger_set() is the only caller of the deactivate() callback,
and it calls led_set_brightness(LED_OFF) anyway after deactivate().
So we can remove the call here.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/8dc929e7-8e14-4c85-aa28-9c5fe2620f52@gmail.comSigned-off-by: Lee Jones <lee@kernel.org>

Add LED_FUNCTION_SPEED_LAN and LED_FUNCTION_SPEED_WAN for LEDs that
indicate link speed of ethernet ports on LAN/WAN. This is useful to
distinguish those LEDs from LEDs that indicate link status (up/down).

example:

Fortinet FortiGate 30E/50E have LEDs that indicate link speed on each
of the ethernet ports in addition to LEDs that indicate link status
(up/down).

- 1000 Mbps: green:speed-(lan|wan)-N
-  100 Mbps: amber:speed-(lan|wan)-N
-   10 Mbps: (none, turned off)
Signed-off-by: INAGAKI Hiroshi <musashino.open@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20240323074326.1428-3-musashino.open@gmail.comSigned-off-by: Lee Jones <lee@kernel.org>

Add LED_FUNCTION_MOBILE for LEDs that indicate status of mobile network
connection. This is useful to distinguish those LEDs from LEDs that
indicates status of wired "wan" connection.

example (on stock fw):

IIJ SA-W2 has "Mobile" LEDs that indicate status (no signal, too low,
low, good) of mobile network connection via dongle connected to USB
port.

- no signal: (none, turned off)
-   too low: green:mobile & red:mobile (amber, blink)
-       low: green:mobile & red:mobile (amber, turned on)
-      good: green:mobile (turned on)
Suggested-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: INAGAKI Hiroshi <musashino.open@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240323074326.1428-2-musashino.open@gmail.comSigned-off-by: Lee Jones <lee@kernel.org>

This is used for the Siemens Simatic IPC BX-59A, which has its LEDs
connected to GPIOs provided by the Nuvoton NCT6126D.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Xing Tong Wu <xingtong.wu@siemens.com>
Link: https://lore.kernel.org/r/20240314070506.2384-1-xingtong_wu@163.comSigned-off-by: Lee Jones <lee@kernel.org>

The PM6150L LPG modules are compatible with the PM8150L LPG modules,
document the PM6150L LPG compatible as fallback for the PM8150L LPG.
Signed-off-by: Danila Tikhonov <danila@jiaxyga.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20240306172710.59780-2-danila@jiaxyga.comSigned-off-by: Lee Jones <lee@kernel.org>

Convert the pca963x DT bindings to YAML schema. The existing properties
are kept without modification, but the example is adapted to the latest
common bindings for LEDs.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20240305004501.849-1-laurent.pinchart@ideasonboard.comSigned-off-by: Lee Jones <lee@kernel.org>

In this driver LEDs are registered using devm_led_classdev_register()
so they are automatically unregistered after module's remove() is done.
led_classdev_unregister() calls module's led_set_brightness() to turn off
the LEDs and that callback uses mutex which was destroyed already
in module's remove() so use devm API instead.
Signed-off-by: George Stark <gnstark@salutedevices.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20240411161032.609544-9-gnstark@salutedevices.comSigned-off-by: Lee Jones <lee@kernel.org>

In this driver LEDs are registered using devm_led_classdev_register()
so they are automatically unregistered after module's remove() is done.
led_classdev_unregister() calls module's led_set_brightness() to turn off
the LEDs and that callback uses mutex which was destroyed already
in module's remove() so use devm API instead.
Signed-off-by: George Stark <gnstark@salutedevices.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20240411161032.609544-8-gnstark@salutedevices.comSigned-off-by: Lee Jones <lee@kernel.org>

In this driver LEDs are registered using devm_led_classdev_register()
so they are automatically unregistered after module's remove() is done.
led_classdev_unregister() calls module's led_set_brightness() to turn off
the LEDs and that callback uses resources which were destroyed already
in module's remove() so use devm API instead of remove().
Signed-off-by: George Stark <gnstark@salutedevices.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20240411161032.609544-7-gnstark@salutedevices.comSigned-off-by: Lee Jones <lee@kernel.org>

In this driver LEDs are registered using devm_led_classdev_register()
so they are automatically unregistered after module's remove() is done.
led_classdev_unregister() calls module's led_set_brightness() to turn off
the LEDs and that callback uses resources which were destroyed already
in module's remove() so use devm API instead of remove().
Signed-off-by: George Stark <gnstark@salutedevices.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20240411161032.609544-6-gnstark@salutedevices.comSigned-off-by: Lee Jones <lee@kernel.org>

In this driver LEDs are registered using devm_led_classdev_register()
so they are automatically unregistered after module's remove() is done.
led_classdev_unregister() calls module's led_set_brightness() to turn off
the LEDs and that callback uses resources which were destroyed already
in module's remove() so use devm API instead of remove().
Also drop explicit turning LEDs off from remove() due to they will be off
anyway by led_classdev_unregister().
Signed-off-by: George Stark <gnstark@salutedevices.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20240411161032.609544-5-gnstark@salutedevices.comSigned-off-by: Lee Jones <lee@kernel.org>

In this driver LEDs are registered using devm_led_classdev_register()
so they are automatically unregistered after module's remove() is done.
led_classdev_unregister() calls module's led_set_brightness() to turn off
the LEDs and that callback uses resources which were destroyed already
in module's remove() so use devm API instead of remove().
Signed-off-by: George Stark <gnstark@salutedevices.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20240411161032.609544-4-gnstark@salutedevices.comSigned-off-by: Lee Jones <lee@kernel.org>

In this driver LEDs are registered using devm_led_classdev_register()
so they are automatically unregistered after module's remove() is done.
led_classdev_unregister() calls module's led_set_brightness() to turn off
the LEDs and that callback uses resources which were destroyed already
in module's remove() so use devm API instead of remove().
Signed-off-by: George Stark <gnstark@salutedevices.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Tested-by: Nikita Travkin <nikita@trvn.ru>
Link: https://lore.kernel.org/r/20240411161032.609544-3-gnstark@salutedevices.comSigned-off-by: Lee Jones <lee@kernel.org>

Using of devm API leads to a certain order of releasing resources.
So all dependent resources which are not devm-wrapped should be deleted
with respect to devm-release order. Mutex is one of such objects that
often is bound to other resources and has no own devm wrapping.
Since mutex_destroy() actually does nothing in non-debug builds
frequently calling mutex_destroy() is just ignored which is safe for now
but wrong formally and can lead to a problem if mutex_destroy() will be
extended so introduce devm_mutex_init().
Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: George Stark <gnstark@salutedevices.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Marek Behún <kabel@kernel.org>
Acked-by: Waiman Long <longman@redhat.com>
Link: https://lore.kernel.org/r/20240411161032.609544-2-gnstark@salutedevices.comSigned-off-by: Lee Jones <lee@kernel.org>

Now that the audio trigger is fully integrated in
sound/core/control_led.c, we can remove it here.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/1e339779-6d04-4392-8ea2-5592c0fd1aa2@gmail.comSigned-off-by: Lee Jones <lee@kernel.org>

This driver is the only one calling ledtrig_audio_set(), therefore
the LED audio trigger isn't usable standalone. So it makes sense
to fully integrate LED audio triger handling here.

The module aliases ensure that the driver is auto-loaded (if built
as module) if a LED device has one of the two audio triggers as
default trigger.

In addition disable building the old audio mute LED trigger.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/107634e6-d9ad-4a9f-881d-1eb72ea1a5a7@gmail.comSigned-off-by: Lee Jones <lee@kernel.org>

If a simple trigger is assigned to a LED, then the LED may be off until
the next led_trigger_event() call. This may be an issue for simple
triggers with rare led_trigger_event() calls, e.g. power supply
charging indicators (drivers/power/supply/power_supply_leds.c).
Therefore persist the brightness value of the last led_trigger_event()
call and use this value if the trigger is assigned to a LED.
In addition add a getter for the trigger brightness value.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/b1358b25-3f30-458d-8240-5705ae007a8a@gmail.comSigned-off-by: Lee Jones <lee@kernel.org>

Pull EFI fixes from Ard Biesheuvel:

 - Fix logic that is supposed to prevent placement of the kernel image
   below LOAD_PHYSICAL_ADDR

 - Use the firmware stack in the EFI stub when running in mixed mode

 - Clear BSS only once when using mixed mode

 - Check efi.get_variable() function pointer for NULL before trying to
   call it

* tag 'efi-fixes-for-v6.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  efi: fix panic in kdump kernel
  x86/efistub: Don't clear BSS twice in mixed mode
  x86/efistub: Call mixed mode boot services on the firmware's stack
  efi/libstub: fix efi_random_alloc() to allocate memory at alloc_min or higher address

Pull x86 fixes from Thomas Gleixner:

 - Ensure that the encryption mask at boot is properly propagated on
   5-level page tables, otherwise the PGD entry is incorrectly set to
   non-encrypted, which causes system crashes during boot.

 - Undo the deferred 5-level page table setup as it cannot work with
   memory encryption enabled.

 - Prevent inconsistent XFD state on CPU hotplug, where the MSR is reset
   to the default value but the cached variable is not, so subsequent
   comparisons might yield the wrong result and as a consequence the
   result prevents updating the MSR.

 - Register the local APIC address only once in the MPPARSE enumeration
   to prevent triggering the related WARN_ONs() in the APIC and topology
   code.

 - Handle the case where no APIC is found gracefully by registering a
   fake APIC in the topology code. That makes all related topology
   functions work correctly and does not affect the actual APIC driver
   code at all.

 - Don't evaluate logical IDs during early boot as the local APIC IDs
   are not yet enumerated and the invoked function returns an error
   code. Nothing requires the logical IDs before the final CPUID
   enumeration takes place, which happens after the enumeration.

 - Cure the fallout of the per CPU rework on UP which misplaced the
   copying of boot_cpu_data to per CPU data so that the final update to
   boot_cpu_data got lost which caused inconsistent state and boot
   crashes.

 - Use copy_from_kernel_nofault() in the kprobes setup as there is no
   guarantee that the address can be safely accessed.

 - Reorder struct members in struct saved_context to work around another
   kmemleak false positive

 - Remove the buggy code which tries to update the E820 kexec table for
   setup_data as that is never passed to the kexec kernel.

 - Update the resource control documentation to use the proper units.

 - Fix a Kconfig warning observed with tinyconfig

* tag 'x86-urgent-2024-03-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot/64: Move 5-level paging global variable assignments back
  x86/boot/64: Apply encryption mask to 5-level pagetable update
  x86/cpu: Add model number for another Intel Arrow Lake mobile processor
  x86/fpu: Keep xfd_state in sync with MSR_IA32_XFD
  Documentation/x86: Document that resctrl bandwidth control units are MiB
  x86/mpparse: Register APIC address only once
  x86/topology: Handle the !APIC case gracefully
  x86/topology: Don't evaluate logical IDs during early boot
  x86/cpu: Ensure that CPU info updates are propagated on UP
  kprobes/x86: Use copy_from_kernel_nofault() to read from unsafe address
  x86/pm: Work around false positive kmemleak report in msr_build_context()
  x86/kexec: Do not update E820 kexec table for setup_data
  x86/config: Fix warning for 'make ARCH=x86_64 tinyconfig'

Pull scheduler doc clarification from Thomas Gleixner:
 "A single update for the documentation of the base_slice_ns tunable to
  clarify that any value which is less than the tick slice has no effect
  because the scheduler tick is not guaranteed to happen within the set
  time slice"

* tag 'sched-urgent-2024-03-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/doc: Update documentation for base_slice_ns and CONFIG_HZ relation

Pull dma-mapping fixes from Christoph Hellwig:
 "This has a set of swiotlb alignment fixes for sometimes very long
  standing bugs from Will. We've been discussion them for a while and
  they should be solid now"

* tag 'dma-mapping-6.9-2024-03-24' of git://git.infradead.org/users/hch/dma-mapping:
  swiotlb: Reinstate page-alignment for mappings >= PAGE_SIZE
  iommu/dma: Force swiotlb_max_mapping_size on an untrusted device
  swiotlb: Fix alignment checks when both allocation and DMA masks are present
  swiotlb: Honour dma_alloc_coherent() alignment in swiotlb_alloc()
  swiotlb: Enforce page alignment in swiotlb_alloc()
  swiotlb: Fix double-allocation of slots due to broken alignment handling

Check if get_next_variable() is actually valid pointer before
calling it. In kdump kernel this method is set to NULL that causes
panic during the kexec-ed kernel boot.

Tested with QEMU and OVMF firmware.

Fixes: bad267f9 ("efi: verify that variable services are supported")
Signed-off-by: Oleksandr Tymoshenko <ovt@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

Clearing BSS should only be done once, at the very beginning.
efi_pe_entry() is the entrypoint from the firmware, which may not clear
BSS and so it is done explicitly. However, efi_pe_entry() is also used
as an entrypoint by the mixed mode startup code, in which case BSS will
already have been cleared, and doing it again at this point will corrupt
global variables holding the firmware's GDT/IDT and segment selectors.

So make the memset() conditional on whether the EFI stub is running in
native mode.

Fixes: b3810c5a ("x86/efistub: Clear decompressor BSS in native EFI entrypoint")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

Normally, the EFI stub calls into the EFI boot services using the stack
that was live when the stub was entered. According to the UEFI spec,
this stack needs to be at least 128k in size - this might seem large but
all asynchronous processing and event handling in EFI runs from the same
stack and so quite a lot of space may be used in practice.

In mixed mode, the situation is a bit different: the bootloader calls
the 32-bit EFI stub entry point, which calls the decompressor's 32-bit
entry point, where the boot stack is set up, using a fixed allocation
of 16k. This stack is still in use when the EFI stub is started in
64-bit mode, and so all calls back into the EFI firmware will be using
the decompressor's limited boot stack.

Due to the placement of the boot stack right after the boot heap, any
stack overruns have gone unnoticed. However, commit

  5c4feadb0011983b ("x86/decompressor: Move global symbol references to C code")

moved the definition of the boot heap into C code, and now the boot
stack is placed right at the base of BSS, where any overruns will
corrupt the end of the .data section.

While it would be possible to work around this by increasing the size of
the boot stack, doing so would affect all x86 systems, and mixed mode
systems are a tiny (and shrinking) fraction of the x86 installed base.

So instead, record the firmware stack pointer value when entering from
the 32-bit firmware, and switch to this stack every time a EFI boot
service call is made.

Cc: <stable@kernel.org> # v6.1+
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

Commit 63bed966 ("x86/startup_64: Defer assignment of 5-level paging
global variables") moved assignment of 5-level global variables to later
in the boot in order to avoid having to use RIP relative addressing in
order to set them. However, when running with 5-level paging and SME
active (mem_encrypt=on), the variables are needed as part of the page
table setup needed to encrypt the kernel (using pgd_none(), p4d_offset(),
etc.). Since the variables haven't been set, the page table manipulation
is done as if 4-level paging is active, causing the system to crash on
boot.

While only a subset of the assignments that were moved need to be set
early, move all of the assignments back into check_la57_support() so that
these assignments aren't spread between two locations. Instead of just
reverting the fix, this uses the new RIP_REL_REF() macro when assigning
the variables.

Fixes: 63bed966 ("x86/startup_64: Defer assignment of 5-level paging global variables")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/2ca419f4d0de719926fd82353f6751f717590a86.1711122067.git.thomas.lendacky@amd.com

When running with 5-level page tables, the kernel mapping PGD entry is
updated to point to the P4D table. The assignment uses _PAGE_TABLE_NOENC,
which, when SME is active (mem_encrypt=on), results in a page table
entry without the encryption mask set, causing the system to crash on
boot.

Change the assignment to use _PAGE_TABLE instead of _PAGE_TABLE_NOENC so
that the encryption mask is set for the PGD entry.

Fixes: 533568e0 ("x86/boot/64: Use RIP_REL_REF() to access early_top_pgt[]")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/8f20345cda7dbba2cf748b286e1bc00816fe649a.1711122067.git.thomas.lendacky@amd.com

This one is the regular laptop CPU.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240322161725.195614-1-tony.luck@intel.com

Commit 67236547 ("x86/fpu: Update XFD state where required") and
commit 8bf26758 ("x86/fpu: Add XFD state to fpstate") introduced a
per CPU variable xfd_state to keep the MSR_IA32_XFD value cached, in
order to avoid unnecessary writes to the MSR.

On CPU hotplug MSR_IA32_XFD is reset to the init_fpstate.xfd, which
wipes out any stale state. But the per CPU cached xfd value is not
reset, which brings them out of sync.

As a consequence a subsequent xfd_update_state() might fail to update
the MSR which in turn can result in XRSTOR raising a #NM in kernel
space, which crashes the kernel.

To fix this, introduce xfd_set_state() to write xfd_state together
with MSR_IA32_XFD, and use it in all places that set MSR_IA32_XFD.

Fixes: 67236547 ("x86/fpu: Update XFD state where required")
Signed-off-by: Adamos Ttofari <attofari@amazon.de>
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240322230439.456571-1-chang.seok.bae@intel.com

Closes: https://lore.kernel.org/lkml/20230511152818.13839-1-attofari@amazon.de