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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
"Here is a small set of driver core changes for 6.13-rc1.
Nothing major for this merge cycle, except for the two simple merge
conflicts are here just to make life interesting.
Included in here are:
- sysfs core changes and preparations for more sysfs api cleanups
that can come through all driver trees after -rc1 is out
- fw_devlink fixes based on many reports and debugging sessions
- list_for_each_reverse() removal, no one was using it!
- last-minute seq_printf() format string bug found and fixed in many
drivers all at once.
- minor bugfixes and changes full details in the shortlog"
* tag 'driver-core-6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (35 commits)
Fix a potential abuse of seq_printf() format string in drivers
cpu: Remove spurious NULL in attribute_group definition
s390/con3215: Remove spurious NULL in attribute_group definition
perf: arm-ni: Remove spurious NULL in attribute_group definition
driver core: Constify bin_attribute definitions
sysfs: attribute_group: allow registration of const bin_attribute
firmware_loader: Fix possible resource leak in fw_log_firmware_info()
drivers: core: fw_devlink: Fix excess parameter description in docstring
driver core: class: Correct WARN() message in APIs class_(for_each|find)_device()
cacheinfo: Use of_property_present() for non-boolean properties
cdx: Fix cdx_mmap_resource() after constifying attr in ->mmap()
drivers: core: fw_devlink: Make the error message a bit more useful
phy: tegra: xusb: Set fwnode for xusb port devices
drm: display: Set fwnode for aux bus devices
driver core: fw_devlink: Stop trying to optimize cycle detection logic
driver core: Constify attribute arguments of binary attributes
sysfs: bin_attribute: add const read/write callback variants
sysfs: implement all BIN_ATTR_* macros in terms of __BIN_ATTR()
sysfs: treewide: constify attribute callback of bin_attribute::llseek()
sysfs: treewide: constify attribute callback of bin_attribute::mmap()
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner:
"A rather large update for timekeeping and timers:
- The final step to get rid of auto-rearming posix-timers
posix-timers are currently auto-rearmed by the kernel when the
signal of the timer is ignored so that the timer signal can be
delivered once the corresponding signal is unignored.
This requires to throttle the timer to prevent a DoS by small
intervals and keeps the system pointlessly out of low power states
for no value. This is a long standing non-trivial problem due to
the lock order of posix-timer lock and the sighand lock along with
life time issues as the timer and the sigqueue have different life
time rules.
Cure this by:
- Embedding the sigqueue into the timer struct to have the same
life time rules. Aside of that this also avoids the lookup of
the timer in the signal delivery and rearm path as it's just a
always valid container_of() now.
- Queuing ignored timer signals onto a seperate ignored list.
- Moving queued timer signals onto the ignored list when the
signal is switched to SIG_IGN before it could be delivered.
- Walking the ignored list when SIG_IGN is lifted and requeue the
signals to the actual signal lists. This allows the signal
delivery code to rearm the timer.
This also required to consolidate the signal delivery rules so they
are consistent across all situations. With that all self test
scenarios finally succeed.
- Core infrastructure for VFS multigrain timestamping
This is required to allow the kernel to use coarse grained time
stamps by default and switch to fine grained time stamps when inode
attributes are actively observed via getattr().
These changes have been provided to the VFS tree as well, so that
the VFS specific infrastructure could be built on top.
- Cleanup and consolidation of the sleep() infrastructure
- Move all sleep and timeout functions into one file
- Rework udelay() and ndelay() into proper documented inline
functions and replace the hardcoded magic numbers by proper
defines.
- Rework the fsleep() implementation to take the reality of the
timer wheel granularity on different HZ values into account.
Right now the boundaries are hard coded time ranges which fail
to provide the requested accuracy on different HZ settings.
- Update documentation for all sleep/timeout related functions
and fix up stale documentation links all over the place
- Fixup a few usage sites
- Rework of timekeeping and adjtimex(2) to prepare for multiple PTP
clocks
A system can have multiple PTP clocks which are participating in
seperate and independent PTP clock domains. So far the kernel only
considers the PTP clock which is based on CLOCK TAI relevant as
that's the clock which drives the timekeeping adjustments via the
various user space daemons through adjtimex(2).
The non TAI based clock domains are accessible via the file
descriptor based posix clocks, but their usability is very limited.
They can't be accessed fast as they always go all the way out to
the hardware and they cannot be utilized in the kernel itself.
As Time Sensitive Networking (TSN) gains traction it is required to
provide fast user and kernel space access to these clocks.
The approach taken is to utilize the timekeeping and adjtimex(2)
infrastructure to provide this access in a similar way how the
kernel provides access to clock MONOTONIC, REALTIME etc.
Instead of creating a duplicated infrastructure this rework
converts timekeeping and adjtimex(2) into generic functionality
which operates on pointers to data structures instead of using
static variables.
This allows to provide time accessors and adjtimex(2) functionality
for the independent PTP clocks in a subsequent step.
- Consolidate hrtimer initialization
hrtimers are set up by initializing the data structure and then
seperately setting the callback function for historical reasons.
That's an extra unnecessary step and makes Rust support less
straight forward than it should be.
Provide a new set of hrtimer_setup*() functions and convert the
core code and a few usage sites of the less frequently used
interfaces over.
The bulk of the htimer_init() to hrtimer_setup() conversion is
already prepared and scheduled for the next merge window.
- Drivers:
- Ensure that the global timekeeping clocksource is utilizing the
cluster 0 timer on MIPS multi-cluster systems.
Otherwise CPUs on different clusters use their cluster specific
clocksource which is not guaranteed to be synchronized with
other clusters.
- Mostly boring cleanups, fixes, improvements and code movement"
* tag 'timers-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (140 commits)
posix-timers: Fix spurious warning on double enqueue versus do_exit()
clocksource/drivers/arm_arch_timer: Use of_property_present() for non-boolean properties
clocksource/drivers/gpx: Remove redundant casts
clocksource/drivers/timer-ti-dm: Fix child node refcount handling
dt-bindings: timer: actions,owl-timer: convert to YAML
clocksource/drivers/ralink: Add Ralink System Tick Counter driver
clocksource/drivers/mips-gic-timer: Always use cluster 0 counter as clocksource
clocksource/drivers/timer-ti-dm: Don't fail probe if int not found
clocksource/drivers:sp804: Make user selectable
clocksource/drivers/dw_apb: Remove unused dw_apb_clockevent functions
hrtimers: Delete hrtimer_init_on_stack()
alarmtimer: Switch to use hrtimer_setup() and hrtimer_setup_on_stack()
io_uring: Switch to use hrtimer_setup_on_stack()
sched/idle: Switch to use hrtimer_setup_on_stack()
hrtimers: Delete hrtimer_init_sleeper_on_stack()
wait: Switch to use hrtimer_setup_sleeper_on_stack()
timers: Switch to use hrtimer_setup_sleeper_on_stack()
net: pktgen: Switch to use hrtimer_setup_sleeper_on_stack()
futex: Switch to use hrtimer_setup_sleeper_on_stack()
fs/aio: Switch to use hrtimer_setup_sleeper_on_stack()
...
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This NULL value is most-likely a copy-paste error from an array
definition. The NULL doesn't have any effect.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/r/20241118-sysfs-const-attribute_group-fixes-v1-3-48e0b0ad8cba@weissschuh.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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The way the clockevent devices are finally stopped while a CPU is
offlining is currently chaotic. The layout being by order:
1) tick_sched_timer_dying() stops the tick and the underlying clockevent
but only for oneshot case. The periodic tick and its related
clockevent still runs.
2) tick_broadcast_offline() detaches and stops the per-cpu oneshot
broadcast and append it to the released list.
3) Some individual clockevent drivers stop the clockevents (a second time if
the tick is oneshot)
4) Once the CPU is dead, a control CPU remotely detaches and stops
(a 3rd time if oneshot mode) the CPU clockevent and adds it to the
released list.
5) The released list containing the broadcast device released on step 2)
and the remotely detached clockevent from step 4) are unregistered.
These random events can be factorized if the current clockevent is
detached and stopped by the dying CPU at the generic layer, that is
from the dying CPU:
a) Stop the tick
b) Stop/detach the underlying per-cpu oneshot broadcast clockevent
c) Stop/detach the underlying clockevent
d) Release / unregister the clockevents from b) and c)
e) Release / unregister the remaining clockevents from the dying CPU.
This part could be performed by the dying CPU
This way the drivers and the tick layer don't need to care about
clockevent operations during cpuhotplug down. This also unifies the tick
behaviour on offline CPUs between oneshot and periodic modes, avoiding
offline ticks altogether for sanity.
Adopt the simplification.
[ tglx: Remove the WARN_ON() in clockevents_register_device() as that
is called from an upcoming CPU before the CPU is marked online ]
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20241029125451.54574-3-frederic@kernel.org
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Add a function to check that an offline CPU has left the tracing
infrastructure in a sane state.
Commit 9bb69ba4c177 ("ACPI: processor_idle: use raw_safe_halt() in
acpi_idle_play_dead()") fixed an issue where the acpi_idle_play_dead()
function called safe_halt() instead of raw_safe_halt(), which had the
side-effect of setting the hardirqs_enabled flag for the offline CPU.
On x86 this triggered warnings from lockdep_assert_irqs_disabled() when
the CPU was brought back online again later. These warnings were too
early for the exception to be handled correctly, leading to a
triple-fault.
Add lockdep_cleanup_dead_cpu() to check for this kind of failure mode,
print the events leading up to it, and correct it so that the CPU can
come online again correctly. Re-introducing the original bug now merely
results in this warning instead:
[ 61.556652] smpboot: CPU 1 is now offline
[ 61.556769] CPU 1 left hardirqs enabled!
[ 61.556915] irq event stamp: 128149
[ 61.556965] hardirqs last enabled at (128149): [<ffffffff81720a36>] acpi_idle_play_dead+0x46/0x70
[ 61.557055] hardirqs last disabled at (128148): [<ffffffff81124d50>] do_idle+0x90/0xe0
[ 61.557117] softirqs last enabled at (128078): [<ffffffff81cec74c>] __do_softirq+0x31c/0x423
[ 61.557199] softirqs last disabled at (128065): [<ffffffff810baae1>] __irq_exit_rcu+0x91/0x100
[boqun: Capitalize the title and reword the message a bit]
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/f7bd2b3b999051bb3ef4be34526a9262008285f5.camel@infradead.org
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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
...
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To update with the latest fixes.
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usleep_range() is a wrapper arount usleep_range_state() which hands in
TASK_UNTINTERRUPTIBLE as state argument.
Use already exising wrapper usleep_range(). No functional change.
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/all/20240904-devel-anna-maria-b4-timers-flseep-v1-2-e98760256370@linutronix.de
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Building the kernel with W=1 generates the following warning:
kernel/cpu.c:2693: warning: This comment starts with '/**',
but isn't a kernel-doc comment.
The function topology_is_core_online() is a simple helper function and
doesn't need a kernel-doc comment.
Use a normal comment instead.
Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20240825221152.71951-2-thorsten.blum@toblux.com
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Pull in upstream changes so further patches don't conflict.
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If a core is offline then enabling SMT should not online CPUs of
this core. By enabling SMT, what is intended is either changing the SMT
value from "off" to "on" or setting the SMT level (threads per core) from a
lower to higher value.
On PowerPC the ppc64_cpu utility can be used, among other things, to
perform the following functions:
ppc64_cpu --cores-on # Get the number of online cores
ppc64_cpu --cores-on=X # Put exactly X cores online
ppc64_cpu --offline-cores=X[,Y,...] # Put specified cores offline
ppc64_cpu --smt={on|off|value} # Enable, disable or change SMT level
If the user has decided to offline certain cores, enabling SMT should
not online CPUs in those cores. This patch fixes the issue and changes
the behaviour as described, by introducing an arch specific function
topology_is_core_online(). It is currently implemented only for PowerPC.
Fixes: 73c58e7e1412 ("powerpc: Add HOTPLUG_SMT support")
Reported-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Closes: https://groups.google.com/g/powerpc-utils-devel/c/wrwVzAAnRlI/m/5KJSoqP4BAAJ
Signed-off-by: Nysal Jan K.A <nysal@linux.ibm.com>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240731030126.956210-2-nysal@linux.ibm.com
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CONFIG_HOTPLUG_PARALLEL expects the architecture to implement
arch_cpuhp_init_parallel_bringup() to decide whether paralllel hotplug is
possible and to do the necessary architecture specific initialization.
There are architectures which can enable it unconditionally and do not
require architecture specific initialization.
Provide a weak fallback for arch_cpuhp_init_parallel_bringup() so that
such architectures are not forced to implement empty stub functions.
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20240716-loongarch-hotplug-v3-2-af59b3bb35c8@flygoat.com
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Provide stub functions for SMT related parallel bring up functions so that
HOTPLUG_PARALLEL can work without HOTPLUG_SMT.
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20240716-loongarch-hotplug-v3-1-af59b3bb35c8@flygoat.com
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 confidential computing updates from Borislav Petkov:
"Unrelated x86/cc changes queued here to avoid ugly cross-merges and
conflicts:
- Carve out CPU hotplug function declarations into a separate header
with the goal to be able to use the lockdep assertions in a more
flexible manner
- As a result, refactor cacheinfo code after carving out a function
to return the cache ID associated with a given cache level
- Cleanups
Add support to be able to kexec TDX guests:
- Expand ACPI MADT CPU offlining support
- Add machinery to prepare CoCo guests memory before kexec-ing into a
new kernel
- Cleanup, readjust and massage related code"
* tag 'x86_cc_for_v6.11_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
ACPI: tables: Print MULTIPROC_WAKEUP when MADT is parsed
x86/acpi: Add support for CPU offlining for ACPI MADT wakeup method
x86/mm: Introduce kernel_ident_mapping_free()
x86/smp: Add smp_ops.stop_this_cpu() callback
x86/acpi: Do not attempt to bring up secondary CPUs in the kexec case
x86/acpi: Rename fields in the acpi_madt_multiproc_wakeup structure
x86/mm: Do not zap page table entries mapping unaccepted memory table during kdump
x86/mm: Make e820__end_ram_pfn() cover E820_TYPE_ACPI ranges
x86/tdx: Convert shared memory back to private on kexec
x86/mm: Add callbacks to prepare encrypted memory for kexec
x86/tdx: Account shared memory
x86/mm: Return correct level from lookup_address() if pte is none
x86/mm: Make x86_platform.guest.enc_status_change_*() return an error
x86/kexec: Keep CR4.MCE set during kexec for TDX guest
x86/relocate_kernel: Use named labels for less confusion
cpu/hotplug, x86/acpi: Disable CPU offlining for ACPI MADT wakeup
cpu/hotplug: Add support for declaring CPU offlining not supported
x86/apic: Mark acpi_mp_wake_* variables as __ro_after_init
x86/acpi: Extract ACPI MADT wakeup code into a separate file
x86/kexec: Remove spurious unconditional JMP from from identity_mapped()
...
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git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Catalin Marinas:
"The biggest part is the virtual CPU hotplug that touches ACPI,
irqchip. We also have some GICv3 optimisation for pseudo-NMIs that has
been queued via the arm64 tree. Otherwise the usual perf updates,
kselftest, various small cleanups.
Core:
- Virtual CPU hotplug support for arm64 ACPI systems
- cpufeature infrastructure cleanups and making the FEAT_ECBHB ID
bits visible to guests
- CPU errata: expand the speculative SSBS workaround to more CPUs
- GICv3, use compile-time PMR values: optimise the way regular IRQs
are masked/unmasked when GICv3 pseudo-NMIs are used, removing the
need for a static key in fast paths by using a priority value
chosen dynamically at boot time
ACPI:
- 'acpi=nospcr' option to disable SPCR as default console for arm64
- Move some ACPI code (cpuidle, FFH) to drivers/acpi/arm64/
Perf updates:
- Rework of the IMX PMU driver to enable support for I.MX95
- Enable support for tertiary match groups in the CMN PMU driver
- Initial refactoring of the CPU PMU code to prepare for the fixed
instruction counter introduced by Arm v9.4
- Add missing PMU driver MODULE_DESCRIPTION() strings
- Hook up DT compatibles for recent CPU PMUs
Kselftest updates:
- Kernel mode NEON fp-stress
- Cleanups, spelling mistakes
Miscellaneous:
- arm64 Documentation update with a minor clarification on TBI
- Fix missing IPI statistics
- Implement raw_smp_processor_id() using thread_info rather than a
per-CPU variable (better code generation)
- Make MTE checking of in-kernel asynchronous tag faults conditional
on KASAN being enabled
- Minor cleanups, typos"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (69 commits)
selftests: arm64: tags: remove the result script
selftests: arm64: tags_test: conform test to TAP output
perf: add missing MODULE_DESCRIPTION() macros
arm64: smp: Fix missing IPI statistics
irqchip/gic-v3: Fix 'broken_rdists' unused warning when !SMP and !ACPI
ACPI: Add acpi=nospcr to disable ACPI SPCR as default console on ARM64
Documentation: arm64: Update memory.rst for TBI
arm64/cpufeature: Replace custom macros with fields from ID_AA64PFR0_EL1
KVM: arm64: Replace custom macros with fields from ID_AA64PFR0_EL1
perf: arm_pmuv3: Include asm/arm_pmuv3.h from linux/perf/arm_pmuv3.h
perf: arm_v6/7_pmu: Drop non-DT probe support
perf/arm: Move 32-bit PMU drivers to drivers/perf/
perf: arm_pmuv3: Drop unnecessary IS_ENABLED(CONFIG_ARM64) check
perf: arm_pmuv3: Avoid assigning fixed cycle counter with threshold
arm64: Kconfig: Fix dependencies to enable ACPI_HOTPLUG_CPU
perf: imx_perf: add support for i.MX95 platform
perf: imx_perf: fix counter start and config sequence
perf: imx_perf: refactor driver for imx93
perf: imx_perf: let the driver manage the counter usage rather the user
perf: imx_perf: add macro definitions for parsing config attr
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull CPU hotplug updates from Thomas Gleixner:
"A small set of SMP/CPU hotplug updates:
- Reverse the order of iteration when freezing secondary CPUs for
hibernation.
This avoids that drivers like the Intel uncore performance counter
have to transfer the assignement of handling the per package uncore
events for every CPU in a package, which is a considerable speedup
on larger systems.
- Add a missing destroy_work_on_stack() invocation in
smp_call_on_cpu() to prevent debug objects to emit a false positive
warning when the stack is freed.
- Small cleanups in comments and a str_plural() conversion"
* tag 'smp-core-2024-07-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
smp: Add missing destroy_work_on_stack() call in smp_call_on_cpu()
cpu/hotplug: Reverse order of iteration in freeze_secondary_cpus()
smp: Use str_plural() to fix Coccinelle warnings
cpu/hotplug: Fix typo in comment
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The 'offline' file in sysfs shows all offline CPUs, including those
that aren't present. User-space is expected to remove not-present CPUs
from this list to learn which CPUs could be brought online.
CPUs can be present but not-enabled. These CPUs can't be brought online
until the firmware policy changes, which comes with an ACPI notification
that will register the CPUs.
With only the offline and present files, user-space is unable to
determine which CPUs it can try to bring online. Add a new CPU mask
that shows this based on all the registered CPUs.
Signed-off-by: James Morse <james.morse@arm.com>
Tested-by: Miguel Luis <miguel.luis@oracle.com>
Tested-by: Vishnu Pajjuri <vishnu@os.amperecomputing.com>
Tested-by: Jianyong Wu <jianyong.wu@arm.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20240529133446.28446-20-Jonathan.Cameron@huawei.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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After the rework of "Parallel CPU bringup", the cmdline "nosmp" and
"maxcpus=0" parameters are not working anymore. These parameters set
setup_max_cpus to zero and that's handed to bringup_nonboot_cpus().
The code there does a decrement before checking for zero, which brings it
into the negative space and brings up all CPUs.
Add a zero check at the beginning of the function to prevent this.
[ tglx: Massaged change log ]
Fixes: 18415f33e2ac4ab382 ("cpu/hotplug: Allow "parallel" bringup up to CPUHP_BP_KICK_AP_STATE")
Fixes: 06c6796e0304234da6 ("cpu/hotplug: Fix off by one in cpuhp_bringup_mask()")
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240618081336.3996825-1-chenhuacai@loongson.cn
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ACPI MADT doesn't allow to offline a CPU after it has been woken up.
Currently, CPU hotplug is prevented based on the confidential computing
attribute which is set for Intel TDX. But TDX is not the only possible user of
the wake up method. Any platform that uses ACPI MADT wakeup method cannot
offline CPU.
Disable CPU offlining on ACPI MADT wakeup enumeration.
This has no visible effects for users: currently, TDX guest is the only platform
that uses the ACPI MADT wakeup method.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Tao Liu <ltao@redhat.com>
Link: https://lore.kernel.org/r/20240614095904.1345461-5-kirill.shutemov@linux.intel.com
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The ACPI MADT mailbox wakeup method doesn't allow to offline a CPU after
it has been woken up.
Currently, offlining is prevented based on the confidential computing attribute
which is set for Intel TDX. But TDX is not the only possible user of the wake up
method. The MADT wakeup can be implemented outside of a confidential computing
environment. Offline support is a property of the wakeup method, not the CoCo
implementation.
Introduce cpu_hotplug_disable_offlining() that can be called to indicate that
CPU offlining should be disabled.
This function is going to replace CC_ATTR_HOTPLUG_DISABLED for ACPI MADT wakeup
method.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Tao Liu <ltao@redhat.com>
Link: https://lore.kernel.org/r/20240614095904.1345461-4-kirill.shutemov@linux.intel.com
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Whenever CPU hotplug state callbacks are registered, the startup callback
is invoked on CPUs that have already reached the provided state in order of
ascending CPU IDs.
In freeze_secondary_cpus() the teardown of CPUs happens in the same are
invoked in the same order. This is known to make a difference is the
current implementation of these callbacks in arch/x86/events/intel/uncore.c:
- uncore_event_cpu_online() designates the first CPU it is invoked for
on each package as the uncore event collector for that package
- uncore_event_cpu_offline() if the CPU being offlined is the event
collector for its package, transfers that responsibility over to
the next (by ascending CPU id) one in the same package
With the current order of CPU teardowns in freeze_secondary_cpus(), the
latter ends up doing the ownership transfer work on every single CPU. That
work involves a synchronize_rcu() call, ultimately unnecessarily degrading
the performance of CPU offlining.
To address this make freeze_secondary_cpus() iterate through the CPUs in
reverse order, so that the teardown happens in order of descending CPU IDs.
[ tglx: Massage change log ]
Signed-off-by: Stanislav Spassov <stanspas@amazon.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240524160449.48594-1-stanspas@amazon.de
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Commit 4205e4786d0b ("cpu/hotplug: Provide dynamic range for prepare
stage") added a dynamic range for the prepare states, but did not handle
the assignment of the dynstate variable in __cpuhp_setup_state_cpuslocked().
This causes the corresponding startup callback not to be invoked when
calling __cpuhp_setup_state_cpuslocked() with the CPUHP_BP_PREPARE_DYN
parameter, even though it should be.
Currently, the users of __cpuhp_setup_state_cpuslocked(), for one reason or
another, have not triggered this bug.
Fixes: 4205e4786d0b ("cpu/hotplug: Provide dynamic range for prepare stage")
Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240515134554.427071-1-ytcoode@gmail.com
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
- The locking around cpuset hotplug processing has always been a bit of
mess which was worked around by making hotplug processing
asynchronous. The asynchronity isn't great and led to other issues.
We tried to make the behavior synchronous a while ago but that led to
lockdep splats. Waiman took another stab at cleaning up and making it
synchronous. The patch has been in -next for well over a month and
there haven't been any complaints, so fingers crossed.
- Tracepoints added to help understanding rstat lock contentions.
- A bunch of minor changes - doc updates, code cleanups and selftests.
* tag 'cgroup-for-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (24 commits)
cgroup/rstat: add cgroup_rstat_cpu_lock helpers and tracepoints
selftests/cgroup: Drop define _GNU_SOURCE
docs: cgroup-v1: Update page cache removal functions
selftests/cgroup: fix uninitialized variables in test_zswap.c
selftests/cgroup: cpu_hogger init: use {} instead of {NULL}
selftests/cgroup: fix clang warnings: uninitialized fd variable
selftests/cgroup: fix clang build failures for abs() calls
cgroup/cpuset: Remove outdated comment in sched_partition_write()
cgroup/cpuset: Fix incorrect top_cpuset flags
cgroup/cpuset: Avoid clearing CS_SCHED_LOAD_BALANCE twice
cgroup/cpuset: Statically initialize more members of top_cpuset
cgroup: Avoid unnecessary looping in cgroup_no_v1()
cgroup, legacy_freezer: update comment for freezer_css_offline()
docs, cgroup: add entries for pids to cgroup-v2.rst
cgroup: don't call cgroup1_pidlist_destroy_all() for v2
cgroup_freezer: update comment for freezer_css_online()
cgroup/rstat: desc member cgrp in cgroup_rstat_flush_release
cgroup/rstat: add cgroup_rstat_lock helpers and tracepoints
cgroup/pids: Remove superfluous zeroing
docs: cgroup-v1: Fix description for css_online
...
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Explicitly disallow enabling mitigations at runtime for kernels that were
built with CONFIG_CPU_MITIGATIONS=n, as some architectures may omit code
entirely if mitigations are disabled at compile time.
E.g. on x86, a large pile of Kconfigs are buried behind CPU_MITIGATIONS,
and trying to provide sane behavior for retroactively enabling mitigations
is extremely difficult, bordering on impossible. E.g. page table isolation
and call depth tracking require build-time support, BHI mitigations will
still be off without additional kernel parameters, etc.
[ bp: Touchups. ]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240420000556.2645001-3-seanjc@google.com
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Rename x86's to CPU_MITIGATIONS, define it in generic code, and force it
on for all architectures exception x86. A recent commit to turn
mitigations off by default if SPECULATION_MITIGATIONS=n kinda sorta
missed that "cpu_mitigations" is completely generic, whereas
SPECULATION_MITIGATIONS is x86-specific.
Rename x86's SPECULATIVE_MITIGATIONS instead of keeping both and have it
select CPU_MITIGATIONS, as having two configs for the same thing is
unnecessary and confusing. This will also allow x86 to use the knob to
manage mitigations that aren't strictly related to speculative
execution.
Use another Kconfig to communicate to common code that CPU_MITIGATIONS
is already defined instead of having x86's menu depend on the common
CPU_MITIGATIONS. This allows keeping a single point of contact for all
of x86's mitigations, and it's not clear that other architectures *want*
to allow disabling mitigations at compile-time.
Fixes: f337a6a21e2f ("x86/cpu: Actually turn off mitigations by default for SPECULATION_MITIGATIONS=n")
Closes: https://lkml.kernel.org/r/20240413115324.53303a68%40canb.auug.org.au
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240420000556.2645001-2-seanjc@google.com
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Initialize cpu_mitigations to CPU_MITIGATIONS_OFF if the kernel is built
with CONFIG_SPECULATION_MITIGATIONS=n, as the help text quite clearly
states that disabling SPECULATION_MITIGATIONS is supposed to turn off all
mitigations by default.
│ If you say N, all mitigations will be disabled. You really
│ should know what you are doing to say so.
As is, the kernel still defaults to CPU_MITIGATIONS_AUTO, which results in
some mitigations being enabled in spite of SPECULATION_MITIGATIONS=n.
Fixes: f43b9876e857 ("x86/retbleed: Add fine grained Kconfig knobs")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Cc: stable@vger.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20240409175108.1512861-2-seanjc@google.com
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Since commit 3a5a6d0c2b03("cpuset: don't nest cgroup_mutex inside
get_online_cpus()"), cpuset hotplug was done asynchronously via a work
function. This is to avoid recursive locking of cgroup_mutex.
Since then, the cgroup locking scheme has changed quite a bit. A
cpuset_mutex was introduced to protect cpuset specific operations.
The cpuset_mutex is then replaced by a cpuset_rwsem. With commit
d74b27d63a8b ("cgroup/cpuset: Change cpuset_rwsem and hotplug lock
order"), cpu_hotplug_lock is acquired before cpuset_rwsem. Later on,
cpuset_rwsem is reverted back to cpuset_mutex. All these locking changes
allow the hotplug code to call into cpuset core directly.
The following commits were also merged due to the asynchronous nature
of cpuset hotplug processing.
- commit b22afcdf04c9 ("cpu/hotplug: Cure the cpusets trainwreck")
- commit 50e76632339d ("sched/cpuset/pm: Fix cpuset vs. suspend-resume
bugs")
- commit 28b89b9e6f7b ("cpuset: handle race between CPU hotplug and
cpuset_hotplug_work")
Clean up all these bandages by making cpuset hotplug
processing synchronous again with the exception that the call to
cgroup_transfer_tasks() to transfer tasks out of an empty cgroup v1
cpuset, if necessary, will still be done via a work function due to the
existing cgroup_mutex -> cpu_hotplug_lock dependency. It is possible
to reverse that dependency, but that will require updating a number of
different cgroup controllers. This special hotplug code path should be
rarely taken anyway.
As all the cpuset states will be updated by the end of the hotplug
operation, we can revert most the above commits except commit
50e76632339d ("sched/cpuset/pm: Fix cpuset vs. suspend-resume bugs")
which is partially reverted. Also removing some cpus_read_lock trylock
attempts in the cpuset partition code as they are no longer necessary
since the cpu_hotplug_lock is now held for the whole duration of the
cpuset hotplug code path.
Signed-off-by: Waiman Long <longman@redhat.com>
Tested-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 APIC updates from Thomas Gleixner:
"Rework of APIC enumeration and topology evaluation.
The current implementation has a couple of shortcomings:
- It fails to handle hybrid systems correctly.
- The APIC registration code which handles CPU number assignents is
in the middle of the APIC code and detached from the topology
evaluation.
- The various mechanisms which enumerate APICs, ACPI, MPPARSE and
guest specific ones, tweak global variables as they see fit or in
case of XENPV just hack around the generic mechanisms completely.
- The CPUID topology evaluation code is sprinkled all over the vendor
code and reevaluates global variables on every hotplug operation.
- There is no way to analyze topology on the boot CPU before bringing
up the APs. This causes problems for infrastructure like PERF which
needs to size certain aspects upfront or could be simplified if
that would be possible.
- The APIC admission and CPU number association logic is
incomprehensible and overly complex and needs to be kept around
after boot instead of completing this right after the APIC
enumeration.
This update addresses these shortcomings with the following changes:
- Rework the CPUID evaluation code so it is common for all vendors
and provides information about the APIC ID segments in a uniform
way independent of the number of segments (Thread, Core, Module,
..., Die, Package) so that this information can be computed instead
of rewriting global variables of dubious value over and over.
- A few cleanups and simplifcations of the APIC, IO/APIC and related
interfaces to prepare for the topology evaluation changes.
- Seperation of the parser stages so the early evaluation which tries
to find the APIC address can be seperately overridden from the late
evaluation which enumerates and registers the local APIC as further
preparation for sanitizing the topology evaluation.
- A new registration and admission logic which
- encapsulates the inner workings so that parsers and guest logic
cannot longer fiddle in it
- uses the APIC ID segments to build topology bitmaps at
registration time
- provides a sane admission logic
- allows to detect the crash kernel case, where CPU0 does not run
on the real BSP, automatically. This is required to prevent
sending INIT/SIPI sequences to the real BSP which would reset
the whole machine. This was so far handled by a tedious command
line parameter, which does not even work in nested crash
scenarios.
- Associates CPU number after the enumeration completed and
prevents the late registration of APICs, which was somehow
tolerated before.
- Converting all parsers and guest enumeration mechanisms over to the
new interfaces.
This allows to get rid of all global variable tweaking from the
parsers and enumeration mechanisms and sanitizes the XEN[PV]
handling so it can use CPUID evaluation for the first time.
- Mopping up existing sins by taking the information from the APIC ID
segment bitmaps.
This evaluates hybrid systems correctly on the boot CPU and allows
for cleanups and fixes in the related drivers, e.g. PERF.
The series has been extensively tested and the minimal late fallout
due to a broken ACPI/MADT table has been addressed by tightening the
admission logic further"
* tag 'x86-apic-2024-03-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (76 commits)
x86/topology: Ignore non-present APIC IDs in a present package
x86/apic: Build the x86 topology enumeration functions on UP APIC builds too
smp: Provide 'setup_max_cpus' definition on UP too
smp: Avoid 'setup_max_cpus' namespace collision/shadowing
x86/bugs: Use fixed addressing for VERW operand
x86/cpu/topology: Get rid of cpuinfo::x86_max_cores
x86/cpu/topology: Provide __num_[cores|threads]_per_package
x86/cpu/topology: Rename topology_max_die_per_package()
x86/cpu/topology: Rename smp_num_siblings
x86/cpu/topology: Retrieve cores per package from topology bitmaps
x86/cpu/topology: Use topology logical mapping mechanism
x86/cpu/topology: Provide logical pkg/die mapping
x86/cpu/topology: Simplify cpu_mark_primary_thread()
x86/cpu/topology: Mop up primary thread mask handling
x86/cpu/topology: Use topology bitmaps for sizing
x86/cpu/topology: Let XEN/PV use topology from CPUID/MADT
x86/xen/smp_pv: Count number of vCPUs early
x86/cpu/topology: Assign hotpluggable CPUIDs during init
x86/cpu/topology: Reject unknown APIC IDs on ACPI hotplug
x86/topology: Add a mechanism to track topology via APIC IDs
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner:
"A large set of updates and features for timers and timekeeping:
- The hierarchical timer pull model
When timer wheel timers are armed they are placed into the timer
wheel of a CPU which is likely to be busy at the time of expiry.
This is done to avoid wakeups on potentially idle CPUs.
This is wrong in several aspects:
1) The heuristics to select the target CPU are wrong by
definition as the chance to get the prediction right is
close to zero.
2) Due to #1 it is possible that timers are accumulated on
a single target CPU
3) The required computation in the enqueue path is just overhead
for dubious value especially under the consideration that the
vast majority of timer wheel timers are either canceled or
rearmed before they expire.
The timer pull model avoids the above by removing the target
computation on enqueue and queueing timers always on the CPU on
which they get armed.
This is achieved by having separate wheels for CPU pinned timers
and global timers which do not care about where they expire.
As long as a CPU is busy it handles both the pinned and the global
timers which are queued on the CPU local timer wheels.
When a CPU goes idle it evaluates its own timer wheels:
- If the first expiring timer is a pinned timer, then the global
timers can be ignored as the CPU will wake up before they
expire.
- If the first expiring timer is a global timer, then the expiry
time is propagated into the timer pull hierarchy and the CPU
makes sure to wake up for the first pinned timer.
The timer pull hierarchy organizes CPUs in groups of eight at the
lowest level and at the next levels groups of eight groups up to
the point where no further aggregation of groups is required, i.e.
the number of levels is log8(NR_CPUS). The magic number of eight
has been established by experimention, but can be adjusted if
needed.
In each group one busy CPU acts as the migrator. It's only one CPU
to avoid lock contention on remote timer wheels.
The migrator CPU checks in its own timer wheel handling whether
there are other CPUs in the group which have gone idle and have
global timers to expire. If there are global timers to expire, the
migrator locks the remote CPU timer wheel and handles the expiry.
Depending on the group level in the hierarchy this handling can
require to walk the hierarchy downwards to the CPU level.
Special care is taken when the last CPU goes idle. At this point
the CPU is the systemwide migrator at the top of the hierarchy and
it therefore cannot delegate to the hierarchy. It needs to arm its
own timer device to expire either at the first expiring timer in
the hierarchy or at the first CPU local timer, which ever expires
first.
This completely removes the overhead from the enqueue path, which
is e.g. for networking a true hotpath and trades it for a slightly
more complex idle path.
This has been in development for a couple of years and the final
series has been extensively tested by various teams from silicon
vendors and ran through extensive CI.
There have been slight performance improvements observed on network
centric workloads and an Intel team confirmed that this allows them
to power down a die completely on a mult-die socket for the first
time in a mostly idle scenario.
There is only one outstanding ~1.5% regression on a specific
overloaded netperf test which is currently investigated, but the
rest is either positive or neutral performance wise and positive on
the power management side.
- Fixes for the timekeeping interpolation code for cross-timestamps:
cross-timestamps are used for PTP to get snapshots from hardware
timers and interpolated them back to clock MONOTONIC. The changes
address a few corner cases in the interpolation code which got the
math and logic wrong.
- Simplifcation of the clocksource watchdog retry logic to
automatically adjust to handle larger systems correctly instead of
having more incomprehensible command line parameters.
- Treewide consolidation of the VDSO data structures.
- The usual small improvements and cleanups all over the place"
* tag 'timers-core- |
