Commit Graph

1988 Commits

Author SHA1 Message Date
Linus Torvalds
1e1ba8d23d Merge tag 'timers-clocksource-2025-03-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull clocksource/event updates from Thomas Gleixner:

  - Add support for suspend/resume in the STM32 LP-Timer driver with a
    follow up fix, which uses the proper method to setup the timer as a
    optional wakeup source instead of trying to force it as mandatory
    wakeup source.

  - The usual device tree updates to enable new SoC models in existing
    drivers.

  - Trivial spelling, style and indentation fixes

* tag 'timers-clocksource-2025-03-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  dt-bindings: timer: Add SiFive CLINT2
  clocksource/drivers/stm32-lptimer: Use wakeup capable instead of init wakeup
  clocksource/drivers/exynos_mct: Fixed a spelling error
  clocksource/drivers/stm32-lptimer: Add support for suspend / resume
  dt-bindings: timer: exynos4210-mct: add samsung,exynos2200-mct-peris compatible
  dt-bindings: timer: exynos4210-mct: Add samsung,exynos990-mct compatible
  dt-bindings: timer: Correct indentation and style in DTS example
2025-03-26 13:30:27 -07:00
Linus Torvalds
a5b3d8660b Merge tag 'hyperv-next-signed-20250324' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Pull hyperv updates from Wei Liu:

 - Add support for running as the root partition in Hyper-V (Microsoft
   Hypervisor) by exposing /dev/mshv (Nuno and various people)

 - Add support for CPU offlining in Hyper-V (Hamza Mahfooz)

 - Misc fixes and cleanups (Roman Kisel, Tianyu Lan, Wei Liu, Michael
   Kelley, Thorsten Blum)

* tag 'hyperv-next-signed-20250324' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (24 commits)
  x86/hyperv: fix an indentation issue in mshyperv.h
  x86/hyperv: Add comments about hv_vpset and var size hypercall input args
  Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs
  hyperv: Add definitions for root partition driver to hv headers
  x86: hyperv: Add mshv_handler() irq handler and setup function
  Drivers: hv: Introduce per-cpu event ring tail
  Drivers: hv: Export some functions for use by root partition module
  acpi: numa: Export node_to_pxm()
  hyperv: Introduce hv_recommend_using_aeoi()
  arm64/hyperv: Add some missing functions to arm64
  x86/mshyperv: Add support for extended Hyper-V features
  hyperv: Log hypercall status codes as strings
  x86/hyperv: Fix check of return value from snp_set_vmsa()
  x86/hyperv: Add VTL mode callback for restarting the system
  x86/hyperv: Add VTL mode emergency restart callback
  hyperv: Remove unused union and structs
  hyperv: Add CONFIG_MSHV_ROOT to gate root partition support
  hyperv: Change hv_root_partition into a function
  hyperv: Convert hypercall statuses to linux error codes
  drivers/hv: add CPU offlining support
  ...
2025-03-25 14:47:04 -07:00
Oliver Upton
d300b0168e Merge branch 'kvm-arm64/pv-cpuid' into kvmarm/next
* kvm-arm64/pv-cpuid:
  : Paravirtualized implementation ID, courtesy of Shameer Kolothum
  :
  : Big-little has historically been a pain in the ass to virtualize. The
  : implementation ID (MIDR, REVIDR, AIDR) of a vCPU can change at the whim
  : of vCPU scheduling. This can be particularly annoying when the guest
  : needs to know the underlying implementation to mitigate errata.
  :
  : "Hyperscalers" face a similar scheduling problem, where VMs may freely
  : migrate between hosts in a pool of heterogenous hardware. And yes, our
  : server-class friends are equally riddled with errata too.
  :
  : In absence of an architected solution to this wart on the ecosystem,
  : introduce support for paravirtualizing the implementation exposed
  : to a VM, allowing the VMM to describe the pool of implementations that a
  : VM may be exposed to due to scheduling/migration.
  :
  : Userspace is expected to intercept and handle these hypercalls using the
  : SMCCC filter UAPI, should it choose to do so.
  smccc: kvm_guest: Fix kernel builds for 32 bit arm
  KVM: selftests: Add test for KVM_REG_ARM_VENDOR_HYP_BMAP_2
  smccc/kvm_guest: Enable errata based on implementation CPUs
  arm64: Make  _midr_in_range_list() an exported function
  KVM: arm64: Introduce KVM_REG_ARM_VENDOR_HYP_BMAP_2
  KVM: arm64: Specify hypercall ABI for retrieving target implementations
  arm64: Modify _midr_range() functions to read MIDR/REVIDR internally

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-19 14:53:16 -07:00
Alexandre Torgue
96bf4b89a6 clocksource/drivers/stm32-lptimer: Use wakeup capable instead of init wakeup
"wakeup-source" property describes a device which has wakeup capability
but should not force this device as a wakeup source.

Fixes: 48b41c5e2d ("clocksource: Add Low Power STM32 timers driver")
Cc: stable@vger.kernel.org
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Rule: add
Link: https://lore.kernel.org/stable/20250306083407.2374894-1-fabrice.gasnier%40foss.st.com
Link: https://lore.kernel.org/r/20250306102501.2980153-1-fabrice.gasnier@foss.st.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2025-03-07 17:55:59 +01:00
Anindya Sundar Gayen
7e1e4e6265 clocksource/drivers/exynos_mct: Fixed a spelling error
Fixed a spelling issue in driver /s/processer/processor/

Signed-off-by: Anindya Sundar Gayen <anindya.sg@samsung.com>
Link: https://lore.kernel.org/r/20250228131138.9208-1-anindya.sg@samsung.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2025-03-07 17:55:59 +01:00
Fabrice Gasnier
b5a497a797 clocksource/drivers/stm32-lptimer: Add support for suspend / resume
Add support for power management on STM32 LPTIMER clocksource driver:
- Upon clockevents_suspend(), shutdown the LPTIMER, and balance the
clk_prepare_enable() from the probe routine.
- Upon clockevents_resume(), restore the prescaler that may have been lost
during low power mode, and restore the clock.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/20250224172101.3448398-1-fabrice.gasnier@foss.st.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2025-03-07 17:55:59 +01:00
Shameer Kolothum
e3121298c7 arm64: Modify _midr_range() functions to read MIDR/REVIDR internally
These changes lay the groundwork for adding support for guest kernels,
allowing them to leverage target CPU implementations provided by the
VMM.

No functional changes intended.

Suggested-by: Oliver Upton <oliver.upton@linux.dev>
Reviewed-by: Sebastian Ott <sebott@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20250221140229.12588-2-shameerali.kolothum.thodi@huawei.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-02-26 13:29:44 -08:00
Nuno Das Neves
db912b8954 hyperv: Change hv_root_partition into a function
Introduce hv_curr_partition_type to store the partition type
as an enum.

Right now this is limited to guest or root partition, but there will
be other kinds in future and the enum is easily extensible.

Set up hv_curr_partition_type early in Hyper-V initialization with
hv_identify_partition_type(). hv_root_partition() just queries this
value, and shouldn't be called before that.

Making this check into a function sets the stage for adding a config
option to gate the compilation of root partition code. In particular,
hv_root_partition() can be stubbed out always be false if root
partition support isn't desired.

Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/1740167795-13296-3-git-send-email-nunodasneves@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <1740167795-13296-3-git-send-email-nunodasneves@linux.microsoft.com>
2025-02-22 02:21:45 +00:00
Artur Rojek
d7e3fd6582 irqchip/jcore-aic, clocksource/drivers/jcore: Fix jcore-pit interrupt request
The jcore-aic irqchip does not have separate interrupt numbers reserved for
cpu-local vs global interrupts. Therefore the device drivers need to
request the given interrupt as per CPU interrupt.

69a9dcbd2d ("clocksource/drivers/jcore: Use request_percpu_irq()")
converted the clocksource driver over to request_percpu_irq(), but failed
to do add all the required changes, resulting in a failure to register PIT
interrupts.

Fix this by:

 1) Explicitly mark the interrupt via irq_set_percpu_devid() in
    jcore_pit_init().

 2) Enable and disable the per CPU interrupt in the CPU hotplug callbacks.

 3) Pass the correct per-cpu cookie to the irq handler by using
    handle_percpu_devid_irq() instead of handle_percpu_irq() in
    handle_jcore_irq().

[ tglx: Massage change log ]

Fixes: 69a9dcbd2d ("clocksource/drivers/jcore: Use request_percpu_irq()")
Signed-off-by: Artur Rojek <contact@artur-rojek.eu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Uros Bizjak <ubizjak@gmail.com>
Link: https://lore.kernel.org/all/20250216175545.35079-3-contact@artur-rojek.eu
2025-02-17 23:27:49 +01:00
Nuno Das Neves
ef5a3c92a8 hyperv: Switch from hyperv-tlfs.h to hyperv/hvhdk.h
Switch to using hvhdk.h everywhere in the kernel. This header
includes all the new Hyper-V headers in include/hyperv, which form a
superset of the definitions found in hyperv-tlfs.h.

This makes it easier to add new Hyper-V interfaces without being
restricted to those in the TLFS doc (reflected in hyperv-tlfs.h).

To be more consistent with the original Hyper-V code, the names of
some definitions are changed slightly. Update those where needed.

Update comments in mshyperv.h files to point to include/hyperv for
adding new definitions.

Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com>
Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com>
Link: https://lore.kernel.org/r/1732577084-2122-5-git-send-email-nunodasneves@linux.microsoft.com
Link: https://lore.kernel.org/r/20250108222138.1623703-3-romank@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-01-10 00:54:21 +00:00
Naman Jain
bcc80dec91 x86/hyperv: Fix hv tsc page based sched_clock for hibernation
read_hv_sched_clock_tsc() assumes that the Hyper-V clock counter is
bigger than the variable hv_sched_clock_offset, which is cached during
early boot, but depending on the timing this assumption may be false
when a hibernated VM starts again (the clock counter starts from 0
again) and is resuming back (Note: hv_init_tsc_clocksource() is not
called during hibernation/resume); consequently,
read_hv_sched_clock_tsc() may return a negative integer (which is
interpreted as a huge positive integer since the return type is u64)
and new kernel messages are prefixed with huge timestamps before
read_hv_sched_clock_tsc() grows big enough (which typically takes
several seconds).

Fix the issue by saving the Hyper-V clock counter just before the
suspend, and using it to correct the hv_sched_clock_offset in
resume. This makes hv tsc page based sched_clock continuous and ensures
that post resume, it starts from where it left off during suspend.
Override x86_platform.save_sched_clock_state and
x86_platform.restore_sched_clock_state routines to correct this as soon
as possible.

Note: if Invariant TSC is available, the issue doesn't happen because
1) we don't register read_hv_sched_clock_tsc() for sched clock:
See commit e5313f1c54 ("clocksource/drivers/hyper-v: Rework
clocksource and sched clock setup");
2) the common x86 code adjusts TSC similarly: see
__restore_processor_state() ->  tsc_verify_tsc_adjust(true) and
x86_platform.restore_sched_clock_state().

Cc: stable@vger.kernel.org
Fixes: 1349401ff1 ("clocksource/drivers/hyper-v: Suspend/resume Hyper-V clocksource for hibernation")
Co-developed-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Naman Jain <namjain@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/20240917053917.76787-1-namjain@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20240917053917.76787-1-namjain@linux.microsoft.com>
2024-12-09 18:42:42 +00:00
Linus Torvalds
e70140ba0d Get rid of 'remove_new' relic from platform driver struct
The continual trickle of small conversion patches is grating on me, and
is really not helping.  Just get rid of the 'remove_new' member
function, which is just an alias for the plain 'remove', and had a
comment to that effect:

  /*
   * .remove_new() is a relic from a prototype conversion of .remove().
   * New drivers are supposed to implement .remove(). Once all drivers are
   * converted to not use .remove_new any more, it will be dropped.
   */

This was just a tree-wide 'sed' script that replaced '.remove_new' with
'.remove', with some care taken to turn a subsequent tab into two tabs
to make things line up.

I did do some minimal manual whitespace adjustment for places that used
spaces to line things up.

Then I just removed the old (sic) .remove_new member function, and this
is the end result.  No more unnecessary conversion noise.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-12-01 15:12:43 -08:00
Rob Herring (Arm)
08b97fbd13 clocksource/drivers/arm_arch_timer: Use of_property_present() for non-boolean properties
The use of of_property_read_bool() for non-boolean properties is
deprecated in favor of of_property_present() when testing for property
presence.

Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20241104190505.272805-2-robh@kernel.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-11-13 13:49:33 +01:00
Tang Bin
5569d7348b clocksource/drivers/gpx: Remove redundant casts
In the function gxp_timer_init, the 'int' type cast in front of the
PTR_ERR() macro is redundant, thus remove it.

Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
Link: https://lore.kernel.org/r/20241107074619.2714-1-tangbin@cmss.chinamobile.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-11-13 13:49:33 +01:00
Javier Carrasco
e5cfc0989d clocksource/drivers/timer-ti-dm: Fix child node refcount handling
of_find_compatible_node() increments the node's refcount, and it must be
decremented again with a call to of_node_put() when the pointer is no
longer required to avoid leaking the resource.

Instead of adding the missing calls to of_node_put() in all execution
paths, use the cleanup attribute for 'arm_timer' by means of the
__free() macro, which automatically calls of_node_put() when the
variable goes out of scope.

Fixes: 25de4ce5ed ("clocksource/drivers/timer-ti-dm: Handle dra7 timer wrap errata i940")
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Link: https://lore.kernel.org/r/20241031-timer-ti-dm-systimer-of_node_put-v3-1-063ee822b73a@gmail.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-11-13 13:49:33 +01:00
Sergio Paracuellos
cd5375610b clocksource/drivers/ralink: Add Ralink System Tick Counter driver
System Tick Counter is present on Ralink SoCs RT3352 and MT7620. This
driver has been in 'arch/mips/ralink' directory since the beggining of
Ralink architecture support. However, it can be moved into a more proper
place in 'drivers/clocksource'. Hence add it here adding also support for
compile test targets and reducing LOC in architecture code folder.

Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Link: https://lore.kernel.org/r/20241028203643.191268-2-sergio.paracuellos@gmail.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-11-13 13:49:33 +01:00
Paul Burton
dfe101bcad clocksource/drivers/mips-gic-timer: Always use cluster 0 counter as clocksource
In a multi-cluster MIPS system, there are multiple GICs - one in each
cluster - each of which has its independent counter. The counters in
each GIC are not synchronized in any way, so they can drift relative
to one another through the lifetime of the system. This is problematic
for a clock source which ought to be global.

Avoid problems by always accessing cluster 0's counter, using
cross-cluster register access. This adds overhead so it is applied only
on multi-cluster systems.

Signed-off-by: Paul Burton <paulburton@kernel.org>
Signed-off-by: Chao-ying Fu <cfu@wavecomp.com>
Signed-off-by: Dragan Mladjenovic <dragan.mladjenovic@syrmia.com>
Signed-off-by: Aleksandar Rikalo <arikalo@gmail.com>
Tested-by: Serge Semin <fancer.lancer@gmail.com>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Tested-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20241019071037.145314-6-arikalo@gmail.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-11-13 13:49:33 +01:00
Judith Mendez
314413317b clocksource/drivers/timer-ti-dm: Don't fail probe if int not found
Some timers may not have an interrupt routed to the A53 GIC, but the
timer PWM functionality can still be used by Linux Kernel. Therefore,
do not fail probe if interrupt is not found and ti,timer-pwm exists.

Signed-off-by: Judith Mendez <jm@ti.com>
Link: https://lore.kernel.org/r/20241011175203.1040568-1-jm@ti.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-11-13 13:49:33 +01:00
Mark Brown
0309f714a0 clocksource/drivers:sp804: Make user selectable
The sp804 is currently only user selectable if COMPILE_TEST, this was
done by commit dfc82faad7 ("clocksource/drivers/sp804: Add
COMPILE_TEST to CONFIG_ARM_TIMER_SP804") in order to avoid it being
spuriously offered on platforms that won't have the hardware since it's
generally only seen on Arm based platforms.  This config is overly
restrictive, while platforms that rely on the SP804 do select it in
their Kconfig there are others such as the Arm fast models which have a
SP804 available but currently unused by Linux.  Relax the dependency to
allow it to be user selectable on arm and arm64 to avoid surprises and
in case someone comes up with a use for extra timer hardware.

Fixes: dfc82faad7 ("clocksource/drivers/sp804: Add COMPILE_TEST to CONFIG_ARM_TIMER_SP804")
Reported-by: Ross Burton <ross.burton@arm.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20241001-arm64-vexpress-sp804-v3-1-0a2d3f7883e4@kernel.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-11-13 13:49:33 +01:00
Dr. David Alan Gilbert
1d58f7f3a1 clocksource/drivers/dw_apb: Remove unused dw_apb_clockevent functions
dw_apb_clockevent_pause(), dw_apb_clockevent_resume() and
dw_apb_clockevent_stop() have been unused since 2021's
commit 1b79fc4f2b ("x86/apb_timer: Remove driver for deprecated
platform")

Remove them.

(Some of the other clockevent functions are still called by
dw_apb_timer_of.c  so I guess it is still in use?)

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Link: https://lore.kernel.org/r/20241025203101.241709-1-linux@treblig.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-11-13 13:49:33 +01:00
Frederic Weisbecker
bf9a001fb8 clocksource/drivers/timer-tegra: Remove clockevents shutdown call on offlining
The clockevents core already detached and unregistered it at this stage.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20241029125451.54574-11-frederic@kernel.org
2024-10-31 10:41:43 +01:00
Frederic Weisbecker
cd165ce831 clocksource/drivers/qcom: Remove clockevents shutdown call on offlining
The clockevents core already detached and unregistered it at this stage.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20241029125451.54574-10-frederic@kernel.org
2024-10-31 10:41:43 +01:00
Frederic Weisbecker
30f8c70a85 clocksource/drivers/armada-370-xp: Remove clockevents shutdown call on offlining
The clockevents core already detached and unregistered it at this stage.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20241029125451.54574-9-frederic@kernel.org
2024-10-31 10:41:43 +01:00
Frederic Weisbecker
ba23b6c7f9 clocksource/drivers/exynos_mct: Remove clockevents shutdown call on offlining
The clockevents core already detached and unregistered it at this stage.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20241029125451.54574-8-frederic@kernel.org
2024-10-31 10:41:43 +01:00
Frederic Weisbecker
15b810e049 clocksource/drivers/arm_global_timer: Remove clockevents shutdown call on offlining
The clockevents core already detached and unregistered it at this stage.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20241029125451.54574-7-frederic@kernel.org
2024-10-31 10:41:42 +01:00
Frederic Weisbecker
78b5c2ca5f clocksource/drivers/arm_arch_timer: Remove clockevents shutdown call on offlining
The clockevents core already detached and unregistered it at this stage.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20241029125451.54574-6-frederic@kernel.org
2024-10-31 10:41:42 +01:00
Linus Torvalds
fc1dc0d507 Merge tag 'x86-timers-2024-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 timer updates from Thomas Gleixner:

 - Use the topology information of number of packages for making the
   decision about TSC trust instead of using the number of online nodes
   which is not reflecting the real topology.

 - Stop the PIT timer 0 when its not in use as to stop pointless
   emulation in the VMM.

 - Fix the PIT timer stop sequence for timer 0 so it truly stops both
   real hardware and buggy VMM emulations.

* tag 'x86-timers-2024-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/tsc: Check for sockets instead of CPUs to make code match comment
  clockevents/drivers/i8253: Fix stop sequence for timer 0
  x86/i8253: Disable PIT timer 0 when not in use
  x86/tsc: Use topology_max_packages() to get package number
2024-09-17 15:27:01 +02:00
Linus Torvalds
9ea925c806 Merge tag 'timers-core-2024-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner:
 "Core:

   - Overhaul of posix-timers in preparation of removing the workaround
     for periodic timers which have signal delivery ignored.

   - Remove the historical extra jiffie in msleep()

     msleep() adds an extra jiffie to the timeout value to ensure
     minimal sleep time. The timer wheel ensures minimal sleep time
     since the large rewrite to a non-cascading wheel, but the extra
     jiffie in msleep() remained unnoticed. Remove it.

   - Make the timer slack handling correct for realtime tasks.

     The procfs interface is inconsistent and does neither reflect
     reality nor conforms to the man page. Show the correct 0 slack for
     real time tasks and enforce it at the core level instead of having
     inconsistent individual checks in various timer setup functions.

   - The usual set of updates and enhancements all over the place.

  Drivers:

   - Allow the ACPI PM timer to be turned off during suspend

   - No new drivers

   - The usual updates and enhancements in various drivers"

* tag 'timers-core-2024-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (43 commits)
  ntp: Make sure RTC is synchronized when time goes backwards
  treewide: Fix wrong singular form of jiffies in comments
  cpu: Use already existing usleep_range()
  timers: Rename next_expiry_recalc() to be unique
  platform/x86:intel/pmc: Fix comment for the pmc_core_acpi_pm_timer_suspend_resume function
  clocksource/drivers/jcore: Use request_percpu_irq()
  clocksource/drivers/cadence-ttc: Add missing clk_disable_unprepare in ttc_setup_clockevent
  clocksource/drivers/asm9260: Add missing clk_disable_unprepare in asm9260_timer_init
  clocksource/drivers/qcom: Add missing iounmap() on errors in msm_dt_timer_init()
  clocksource/drivers/ingenic: Use devm_clk_get_enabled() helpers
  platform/x86:intel/pmc: Enable the ACPI PM Timer to be turned off when suspended
  clocksource: acpi_pm: Add external callback for suspend/resume
  clocksource/drivers/arm_arch_timer: Using for_each_available_child_of_node_scoped()
  dt-bindings: timer: rockchip: Add rk3576 compatible
  timers: Annotate possible non critical data race of next_expiry
  timers: Remove historical extra jiffie for timeout in msleep()
  hrtimer: Use and report correct timerslack values for realtime tasks
  hrtimer: Annotate hrtimer_cpu_base_.*_expiry() for sparse.
  timers: Add sparse annotation for timer_sync_wait_running().
  signal: Replace BUG_ON()s
  ...
2024-09-17 07:25:37 +02:00
Thomas Gleixner
2f7eedca6c Merge branch 'linus' into timers/core
To update with the latest fixes.
2024-09-10 13:49:53 +02:00
Linus Torvalds
fb92a1ffc1 Merge tag 'hyperv-fixes-signed-20240908' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Pull hyperv fixes from Wei Liu:

 - Add a documentation overview of Confidential Computing VM support
   (Michael Kelley)

 - Use lapic timer in a TDX VM without paravisor (Dexuan Cui)

 - Set X86_FEATURE_TSC_KNOWN_FREQ when Hyper-V provides frequency
   (Michael Kelley)

 - Fix a kexec crash due to VP assist page corruption (Anirudh
   Rayabharam)

 - Python3 compatibility fix for lsvmbus (Anthony Nandaa)

 - Misc fixes (Rachel Menge, Roman Kisel, zhang jiao, Hongbo Li)

* tag 'hyperv-fixes-signed-20240908' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  hv: vmbus: Constify struct kobj_type and struct attribute_group
  tools: hv: rm .*.cmd when make clean
  x86/hyperv: fix kexec crash due to VP assist page corruption
  Drivers: hv: vmbus: Fix the misplaced function description
  tools: hv: lsvmbus: change shebang to use python3
  x86/hyperv: Set X86_FEATURE_TSC_KNOWN_FREQ when Hyper-V provides frequency
  Documentation: hyperv: Add overview of Confidential Computing VM support
  clocksource: hyper-v: Use lapic timer in a TDX VM without paravisor
  Drivers: hv: Remove deprecated hv_fcopy declarations
2024-09-09 09:31:55 -07:00
Uros Bizjak
69a9dcbd2d clocksource/drivers/jcore: Use request_percpu_irq()
Use request_percpu_irq() instead of request_irq() to solve
the following sparse warning:

jcore-pit.c:173:40: warning: incorrect type in argument 5 (different address spaces)
jcore-pit.c:173:40:    expected void *dev
jcore-pit.c:173:40:    got struct jcore_pit [noderef] __percpu *static [assigned] [toplevel] jcore_pit_percpu

Compile tested only.

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Rich Felker <dalias@libc.org>
Link: https://lore.kernel.org/r/20240902104810.21080-1-ubizjak@gmail.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-09-06 14:49:21 +02:00
Gaosheng Cui
2e02da1d86 clocksource/drivers/cadence-ttc: Add missing clk_disable_unprepare in ttc_setup_clockevent
Add the missing clk_disable_unprepare() before return in
ttc_setup_clockevent().

Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Reviewed-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/20240803064253.331946-3-cuigaosheng1@huawei.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-09-06 14:49:21 +02:00
Gaosheng Cui
6cc11b65e5 clocksource/drivers/asm9260: Add missing clk_disable_unprepare in asm9260_timer_init
Add the missing clk_disable_unprepare() before return in
asm9260_timer_init().

Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Link: https://lore.kernel.org/r/20240803064253.331946-2-cuigaosheng1@huawei.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-09-06 14:49:21 +02:00
Ankit Agrawal
ca140a0dc0 clocksource/drivers/qcom: Add missing iounmap() on errors in msm_dt_timer_init()
Add the missing iounmap() when clock frequency fails to get read by the
of_property_read_u32() call, or if the call to msm_timer_init() fails.

Fixes: 6e3321631a ("ARM: msm: Add DT support to msm_timer")
Signed-off-by: Ankit Agrawal <agrawal.ag.ankit@gmail.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20240713095713.GA430091@bnew-VirtualBox
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-09-06 14:49:21 +02:00
Huan Yang
414b2fb4bb clocksource/drivers/ingenic: Use devm_clk_get_enabled() helpers
The devm_clk_get_enabled() helpers:
    - call devm_clk_get()
    - call clk_prepare_enable() and register what is needed in order to
     call clk_disable_unprepare() when needed, as a managed resource.

This simplifies the code and avoids the calls to clk_disable_unprepare().

Signed-off-by: Huan Yang <link@vivo.com>
Link: https://lore.kernel.org/r/20240820094603.103598-1-link@vivo.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-09-06 14:49:20 +02:00
Marek Maslanka
56bd72e9cd clocksource: acpi_pm: Add external callback for suspend/resume
Provides the capability to register an external callback for the ACPI PM
timer, which is called during the suspend and resume processes.

Signed-off-by: Marek Maslanka <mmaslanka@google.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20240812184150.1079924-1-mmaslanka@google.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-09-06 14:49:20 +02:00
Zhang Zekun
a7456d7d1b clocksource/drivers/arm_arch_timer: Using for_each_available_child_of_node_scoped()
for_each_available_child_of_node_scoped() can put the device_node
automatically. So, using it to make the code logic more simple and
remove the device_node clean up code.

Signed-off-by: Zhang Zekun <zhangzekun11@huawei.com>
Link: https://lore.kernel.org/r/20240807074655.52157-1-zhangzekun11@huawei.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-09-06 14:49:20 +02:00
Jacky Bai
3d5c2f8e75 clocksource/drivers/imx-tpm: Fix next event not taking effect sometime
The value written into the TPM CnV can only be updated into the hardware
when the counter increases. Additional writes to the CnV write buffer are
ignored until the register has been updated. Therefore, we need to check
if the CnV has been updated before continuing. This may require waiting for
1 counter cycle in the worst case.

Cc: stable@vger.kernel.org
Fixes: 059ab7b82e ("clocksource/drivers/imx-tpm: Add imx tpm timer support")
Signed-off-by: Jacky Bai <ping.bai@nxp.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Ye Li <ye.li@nxp.com>
Reviewed-by: Jason Liu <jason.hui.liu@nxp.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20240725193355.1436005-2-Frank.Li@nxp.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-09-02 10:04:15 +02:00
Jacky Bai
5b8843fcd4 clocksource/drivers/imx-tpm: Fix return -ETIME when delta exceeds INT_MAX
In tpm_set_next_event(delta), return -ETIME by wrong cast to int when delta
is larger than INT_MAX.

For example:

tpm_set_next_event(delta = 0xffff_fffe)
{
        ...
        next = tpm_read_counter(); // assume next is 0x10
        next += delta; // next will 0xffff_fffe + 0x10 = 0x1_0000_000e
        now = tpm_read_counter();  // now is 0x10
        ...

        return (int)(next - now) <= 0 ? -ETIME : 0;
                     ^^^^^^^^^^
                     0x1_0000_000e - 0x10 = 0xffff_fffe, which is -2 when
                     cast to int. So return -ETIME.
}

To fix this, introduce a 'prev' variable and check if 'now - prev' is
larger than delta.

Cc: stable@vger.kernel.org
Fixes: 059ab7b82e ("clocksource/drivers/imx-tpm: Add imx tpm timer support")
Signed-off-by: Jacky Bai <ping.bai@nxp.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Ye Li <ye.li@nxp.com>
Reviewed-by: Jason Liu <jason.hui.liu@nxp.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20240725193355.1436005-1-Frank.Li@nxp.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-09-02 10:04:15 +02:00
Daniel Lezcano
471ef0b5a8 clocksource/drivers/timer-of: Remove percpu irq related code
GCC's named address space checks errors out with:

drivers/clocksource/timer-of.c: In function ‘timer_of_irq_exit’:
drivers/clocksource/timer-of.c:29:46: error: passing argument 2 of
‘free_percpu_irq’ from pointer to non-enclosed address space
  29 |                 free_percpu_irq(of_irq->irq, clkevt);
     |                                              ^~~~~~
In file included from drivers/clocksource/timer-of.c:8:
./include/linux/interrupt.h:201:43: note: expected ‘__seg_gs void *’
but argument is of type ‘struct clock_event_device *’
 201 | extern void free_percpu_irq(unsigned int, void __percpu *);
     |                                           ^~~~~~~~~~~~~~~
drivers/clocksource/timer-of.c: In function ‘timer_of_irq_init’:
drivers/clocksource/timer-of.c:74:51: error: passing argument 4 of
‘request_percpu_irq’ from pointer to non-enclosed address space
  74 |                                    np->full_name, clkevt) :
     |                                                   ^~~~~~
./include/linux/interrupt.h:190:56: note: expected ‘__seg_gs void *’
but argument is of type ‘struct clock_event_device *’
 190 |                    const char *devname, void __percpu *percpu_dev_id)

Sparse warns about:

timer-of.c:29:46: warning: incorrect type in argument 2 (different address spaces)
timer-of.c:29:46:    expected void [noderef] __percpu *
timer-of.c:29:46:    got struct clock_event_device *clkevt
timer-of.c:74:51: warning: incorrect type in argument 4 (different address spaces)
timer-of.c:74:51:    expected void [noderef] __percpu *percpu_dev_id
timer-of.c:74:51:    got struct clock_event_device *clkevt

It appears the code is incorrect as reported by Uros Bizjak:

"The referred code is questionable as it tries to reuse
the clkevent pointer once as percpu pointer and once as generic
pointer, which should be avoided."

This change removes the percpu related code as no drivers is using it.

[Daniel: Fixed the description]

Fixes: dc11bae785 ("clocksource/drivers: Add timer-of common init routine")
Reported-by: Uros Bizjak <ubizjak@gmail.com>
Tested-by: Uros Bizjak <ubizjak@gmail.com>
Link: https://lore.kernel.org/r/20240819100335.2394751-1-daniel.lezcano@linaro.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-09-02 10:04:15 +02:00
David Woodhouse
531b2ca0a9 clockevents/drivers/i8253: Fix stop sequence for timer 0
According to the data sheet, writing the MODE register should stop the
counter (and thus the interrupts). This appears to work on real hardware,
at least modern Intel and AMD systems. It should also work on Hyper-V.

However, on some buggy virtual machines the mode change doesn't have any
effect until the counter is subsequently loaded (or perhaps when the IRQ
next fires).

So, set MODE 0 and then load the counter, to ensure that those buggy VMs
do the right thing and the interrupts stop. And then write MODE 0 *again*
to stop the counter on compliant implementations too.

Apparently, Hyper-V keeps firing the IRQ *repeatedly* even in mode zero
when it should only happen once, but the second MODE write stops that too.

Userspace test program (mostly written by tglx):
=====
 #include <stdio.h>
 #include <unistd.h>
 #include <stdlib.h>
 #include <stdint.h>
 #include <sys/io.h>

static __always_inline void __out##bwl(type value, uint16_t port)	\
{									\
	asm volatile("out" #bwl " %" #bw "0, %w1"			\
		     : : "a"(value), "Nd"(port));			\
}									\
									\
static __always_inline type __in##bwl(uint16_t port)			\
{									\
	type value;							\
	asm volatile("in" #bwl " %w1, %" #bw "0"			\
		     : "=a"(value) : "Nd"(port));			\
	return value;							\
}

BUILDIO(b, b, uint8_t)

 #define inb __inb
 #define outb __outb

 #define PIT_MODE	0x43
 #define PIT_CH0	0x40
 #define PIT_CH2	0x42

static int is8254;

static void dump_pit(void)
{
	if (is8254) {
		// Latch and output counter and status
		outb(0xC2, PIT_MODE);
		printf("%02x %02x %02x\n", inb(PIT_CH0), inb(PIT_CH0), inb(PIT_CH0));
	} else {
		// Latch and output counter
		outb(0x0, PIT_MODE);
		printf("%02x %02x\n", inb(PIT_CH0), inb(PIT_CH0));
	}
}

int main(int argc, char* argv[])
{
	int nr_counts = 2;

	if (argc > 1)
		nr_counts = atoi(argv[1]);

	if (argc > 2)
		is8254 = 1;

	if (ioperm(0x40, 4, 1) != 0)
		return 1;

	dump_pit();

	printf("Set oneshot\n");
	outb(0x38, PIT_MODE);
	outb(0x00, PIT_CH0);
	outb(0x0F, PIT_CH0);

	dump_pit();
	usleep(1000);
	dump_pit();

	printf("Set periodic\n");
	outb(0x34, PIT_MODE);
	outb(0x00, PIT_CH0);
	outb(0x0F, PIT_CH0);

	dump_pit();
	usleep(1000);
	dump_pit();
	dump_pit();
	usleep(100000);
	dump_pit();
	usleep(100000);
	dump_pit();

	printf("Set stop (%d counter writes)\n", nr_counts);
	outb(0x30, PIT_MODE);
	while (nr_counts--)
		outb(0xFF, PIT_CH0);

	dump_pit();
	usleep(100000);
	dump_pit();
	usleep(100000);
	dump_pit();

	printf("Set MODE 0\n");
	outb(0x30, PIT_MODE);

	dump_pit();
	usleep(100000);
	dump_pit();
	usleep(100000);
	dump_pit();

	return 0;
}
=====

Suggested-by: Sean Christopherson <seanjc@google.com>
Co-developed-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhkelley@outlook.com>
Link: https://lore.kernel.org/all/20240802135555.564941-2-dwmw2@infradead.org
2024-08-02 18:27:05 +02:00
David Woodhouse
70e6b7d9ae x86/i8253: Disable PIT timer 0 when not in use
Leaving the PIT interrupt running can cause noticeable steal time for
virtual guests. The VMM generally has a timer which toggles the IRQ input
to the PIC and I/O APIC, which takes CPU time away from the guest. Even
on real hardware, running the counter may use power needlessly (albeit
not much).

Make sure it's turned off if it isn't going to be used.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhkelley@outlook.com>
Link: https://lore.kernel.org/all/20240802135555.564941-1-dwmw2@infradead.org
2024-08-02 18:27:05 +02:00
Luca Ceresoli
9722c3b66e of: remove internal arguments from of_property_for_each_u32()
The of_property_for_each_u32() macro needs five parameters, two of which
are primarily meant as internal variables for the macro itself (in the
for() clause). Yet these two parameters are used by a few drivers, and this
can be considered misuse or at least bad practice.

Now that the kernel uses C11 to build, these two parameters can be avoided
by declaring them internally, thus changing this pattern:

  struct property *prop;
  const __be32 *p;
  u32 val;

  of_property_for_each_u32(np, "xyz", prop, p, val) { ... }

to this:

  u32 val;

  of_property_for_each_u32(np, "xyz", val) { ... }

However two variables cannot be declared in the for clause even with C11,
so declare one struct that contain the two variables we actually need. As
the variables inside this struct are not meant to be used by users of this
macro, give the struct instance the noticeable name "_it" so it is visible
during code reviews, helping to avoid new code to use it directly.

Most usages are trivially converted as they do not use those two
parameters, as expected. The non-trivial cases are:

 - drivers/clk/clk.c, of_clk_get_parent_name(): easily doable anyway
 - drivers/clk/clk-si5351.c, si5351_dt_parse(): this is more complex as the
   checks had to be replicated in a different way, making code more verbose
   and somewhat uglier, but I refrained from a full rework to keep as much
   of the original code untouched having no hardware to test my changes

All the changes have been build tested. The few for which I have the
hardware have been runtime-tested too.

Reviewed-by: Andre Przywara <andre.przywara@arm.com> # drivers/clk/sunxi/clk-simple-gates.c, drivers/clk/sunxi/clk-sun8i-bus-gates.c
Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> # drivers/gpio/gpio-brcmstb.c
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com> # drivers/irqchip/irq-atmel-aic-common.c
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # drivers/iio/adc/ti_am335x_adc.c
Acked-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com> # drivers/pwm/pwm-samsung.c
Acked-by: Richard Leitner <richard.leitner@linux.dev> # drivers/usb/misc/usb251xb.c
Acked-by: Mark Brown <broonie@kernel.org> # sound/soc/codecs/arizona.c
Reviewed-by: Richard Fitzgerald <rf@opensource.cirrus.com> # sound/soc/codecs/arizona.c
Acked-by: Michael Ellerman <mpe@ellerman.id.au> # arch/powerpc/sysdev/xive/spapr.c
Acked-by: Stephen Boyd <sboyd@kernel.org> # clk
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Acked-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20240724-of_property_for_each_u32-v3-1-bea82ce429e2@bootlin.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
2024-07-25 06:53:47 -05:00
Chris Packham
4bdc3eaa10 clocksource/drivers/realtek: Add timer driver for rtl-otto platforms
The timer/counter block on the Realtek SoCs provides up to 5 timers. It
also includes a watchdog timer which is handled by the
realtek_otto_wdt.c driver.

One timer will be used per CPU as a local clock event generator. An
additional timer will be used as an overal stable clocksource.

Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>
Signed-off-by: Sander Vanheule <sander@svanheule.net>
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Link: https://lore.kernel.org/r/20240710043524.1535151-8-chris.packham@alliedtelesis.co.nz
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-07-12 16:07:06 +02:00
Jiaxun Yang
5e4bfd66ec clocksource/drivers/mips-gic-timer: Correct sched_clock width
Counter width of GIC is configurable and can be read from a
register.

Use width value from the register for sched_clock.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Link: https://lore.kernel.org/r/20240612-mips-clks-v2-7-a57e6f49f3db@flygoat.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-07-12 16:07:05 +02:00
Jiaxun Yang
cc9b2c590e clocksource/drivers/mips-gic-timer: Refine rating computation
It is a good clocksource which usually go as fast as CPU core
and have a low access latency, so raise the base of rating
from Good to desired when we know that it has a stable frequency.

Increase frequency addend dividend to 10000000 (10MHz) to
reasonably accommodate multi GHz level clock, also cap rating
within current level.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Link: https://lore.kernel.org/r/20240612-mips-clks-v2-6-a57e6f49f3db@flygoat.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-07-12 16:07:05 +02:00
Niklas Söderlund
db19d3aa77 clocksource/drivers/sh_cmt: Address race condition for clock events
There is a race condition in the CMT interrupt handler. In the interrupt
handler the driver sets a driver private flag, FLAG_IRQCONTEXT. This
flag is used to indicate any call to set_next_event() should not be
directly propagated to the device, but instead cached. This is done as
the interrupt handler itself reprograms the device when needed before it
completes and this avoids this operation to take place twice.

It is unclear why this design was chosen, my suspicion is to allow the
struct clock_event_device.event_handler callback, which is called while
the FLAG_IRQCONTEXT is set, can update the next event without having to
write to the device twice.

Unfortunately there is a race between when the FLAG_IRQCONTEXT flag is
set and later cleared where the interrupt handler have already started to
write the next event to the device. If set_next_event() is called in
this window the value is only cached in the driver but not written. This
leads to the board to misbehave, or worse lockup and produce a splat.

   rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
   rcu:     0-...!: (0 ticks this GP) idle=f5e0/0/0x0 softirq=519/519 fqs=0 (false positive?)
   rcu:     (detected by 1, t=6502 jiffies, g=-595, q=77 ncpus=2)
   Sending NMI from CPU 1 to CPUs 0:
   NMI backtrace for cpu 0
   CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.10.0-rc5-arm64-renesas-00019-g74a6f86eaf1c-dirty #20
   Hardware name: Renesas Salvator-X 2nd version board based on r8a77965 (DT)
   pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
   pc : tick_check_broadcast_expired+0xc/0x40
   lr : cpu_idle_poll.isra.0+0x8c/0x168
   sp : ffff800081c63d70
   x29: ffff800081c63d70 x28: 00000000580000c8 x27: 00000000bfee5610
   x26: 0000000000000027 x25: 0000000000000000 x24: 0000000000000000
   x23: ffff00007fbb9100 x22: ffff8000818f1008 x21: ffff8000800ef07c
   x20: ffff800081c79ec0 x19: ffff800081c70c28 x18: 0000000000000000
   x17: 0000000000000000 x16: 0000000000000000 x15: 0000ffffc2c717d8
   x14: 0000000000000000 x13: ffff000009c18080 x12: ffff8000825f7fc0
   x11: 0000000000000000 x10: ffff8000818f3cd4 x9 : 0000000000000028
   x8 : ffff800081c79ec0 x7 : ffff800081c73000 x6 : 0000000000000000
   x5 : 0000000000000000 x4 : ffff7ffffe286000 x3 : 0000000000000000
   x2 : ffff7ffffe286000 x1 : ffff800082972900 x0 : ffff8000818f1008
   Call trace:
    tick_check_broadcast_expired+0xc/0x40
    do_idle+0x9c/0x280
    cpu_startup_entry+0x34/0x40
    kernel_init+0x0/0x11c
    do_one_initcall+0x0/0x260
    __primary_switched+0x80/0x88
   rcu: rcu_preempt kthread timer wakeup didn't happen for 6501 jiffies! g-595 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
   rcu:     Possible timer handling issue on cpu=0 timer-softirq=262
   rcu: rcu_preempt kthread starved for 6502 jiffies! g-595 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
   rcu:     Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
   rcu: RCU grace-period kthread stack dump:
   task:rcu_preempt     state:I stack:0     pid:15    tgid:15    ppid:2      flags:0x00000008
   Call trace:
    __switch_to+0xbc/0x100
    __schedule+0x358/0xbe0
    schedule+0x48/0x148
    schedule_timeout+0xc4/0x138
    rcu_gp_fqs_loop+0x12c/0x764
    rcu_gp_kthread+0x208/0x298
    kthread+0x10c/0x110
    ret_from_fork+0x10/0x20

The design have been part of the driver since it was first merged in
early 2009. It becomes increasingly harder to trigger the issue the
older kernel version one tries. It only takes a few boots on v6.10-rc5,
while hundreds of boots are needed to trigger it on v5.10.

Close the race condition by using the CMT channel lock for the two
competing sections. The channel lock was added to the driver after its
initial design.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Link: https://lore.kernel.org/r/20240702190230.3825292-1-niklas.soderlund+renesas@ragnatech.se
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-07-12 16:07:05 +02:00
Li kunyu
f3539a6a69 clocksource/driver/arm_global_timer: Remove unnecessary ‘0’ values from err
The 'err' variable is initialized whatever the code path, it is
pointless to initialize it when it is declared.

Signed-off-by: Li kunyu <kunyu@nfschina.com>
Link: https://lore.kernel.org/r/20240705052159.22235-1-kunyu@nfschina.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-07-12 16:07:05 +02:00
Li kunyu
7cbbcbd4b5 clocksource/drivers/arm_arch_timer: Remove unnecessary ‘0’ values from irq
The irq variable is initialized whatever the code path, it is poinless
to initialize when declaring it.

Signed-off-by: Li kunyu <kunyu@nfschina.com>
Link: https://lore.kernel.org/r/20240705040729.21961-1-kunyu@nfschina.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-07-12 16:07:05 +02:00
Dexuan Cui
7f828d5fff clocksource: hyper-v: Use lapic timer in a TDX VM without paravisor
In a TDX VM without paravisor, currently the default timer is the Hyper-V
timer, which depends on the slow VM Reference Counter MSR: the Hyper-V TSC
page is not enabled in such a VM because the VM uses Invariant TSC as a
better clocksource and it's challenging to mark the Hyper-V TSC page shared
in very early boot.

Lower the rating of the Hyper-V timer so the local APIC timer becomes the
the default timer in such a VM, and print a warning in case Invariant TSC
is unavailable in such a VM. This change should cause no perceivable
performance difference.

Cc: stable@vger.kernel.org # 6.6+
Reviewed-by: Roman Kisel <romank@linux.microsoft.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/20240621061614.8339-1-decui@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20240621061614.8339-1-decui@microsoft.com>
2024-06-24 07:06:29 +00:00