Panther Lake supports the following requestable C-states: C1, C1E, C6S,
C10.
The parameters of these C-states should be consistent across all
systems based on Panther Lake, so add a custom C-states table for it
that will override C-state parameters supplied by platform firmware
that may vary from one platform to another and may not represent the
most optimum choice.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
[ rjw: Changelog expansion ]
Link: https://patch.msgid.link/20260309083818.79588-1-dedekind1@gmail.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Add a new module parameter that allows adjusting the C-states table used by
the driver.
Currently, the C-states table is hardcoded in the driver based on the CPU
model. The goal is to have good enough defaults for most users.
However, C-state characteristics, such as exit latency and residency, can
vary between different variants of the same CPU model and BIOS settings.
Moreover, different platform usage models and user preferences may benefit
from different C-state target_residency values.
Provide a way for users to adjust the C-states table via a module parameter
"table". The general format is:
"state1:latency1:target_residency1,state2:latency2:target_residency2,..."
In other words, represent each C-state by its name, exit latency (in
microseconds), and target residency (in microseconds), separated by colons.
Separate multiple C-states by commas.
For example, suppose a CPU has 3 C-states with the following
characteristics:
C1: exit_latency=1, target_residency=2
C1E: exit_latency=10, target_residency=10
C6: exit_latency=100, target_residency=500
Users can specify a custom C-states table as follows:
1. intel_idle.table="C1:2:2,C1E:5:20,C6:150:600"
Result: C1: exit_latency=2, target_residency=2
C1E: exit_latency=5, target_residency=20
C6: exit_latency=150, target_residency=600
2. intel_idle.table="C6::400"
Result: C1: exit_latency=1, target_residency=2 (unchanged)
C1E: exit_latency=10, target_residency=10 (unchanged)
C6: exit_latency=100, target_residency=400
(only target_residency changed)
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Link: https://patch.msgid.link/20251216080402.156988-3-dedekind1@gmail.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reorder initialization calls to initialize the internal driver data before
sysfs:
Was:
intel_idle_sysfs_init();
intel_idle_cpuidle_driver_init();
Now:
intel_idle_cpuidle_driver_init();
intel_idle_sysfs_init();
Follow the general principle that drivers should initialize internal state
before registering external interfaces like sysfs, avoiding potential usage
before full initialization.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Link: https://patch.msgid.link/20251216080402.156988-2-dedekind1@gmail.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Remove the 'preferred_cstates' module parameter as it is not really useful.
The parameter currently only affects Alder Lake, where it controls C1/C1E
preference, with C1E being the default. The parameter does not support any
other platform. For example, Meteor Lake has a similar C1/C1E limitation,
but the parameter does not support Meteor Lake. This indicates that the
parameter is not very useful.
Generally, independent C1 and C1E are important for server platforms where
low latency is key. However, they are not as important for client platforms,
like Alder Lake, where C1E providing better energy savings is generally
preferred.
The parameter was originally introduced for Sapphire Rapids Xeon:
da0e58c038 intel_idle: add 'preferred_cstates' module argument
Later it was added to Alder Lake:
d1cf8bbfed ("intel_idle: Add AlderLake support")
But it was removed from Sapphire Rapids when firmware fixed the C1/C1E
limitation:
1548fac47a ("intel_idle: make SPR C1 and C1E be independent")
So Alder Lake is the only platform left where this parameter has any effect.
Remove this parameter to simplify the driver and reduce maintenance burden.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Link: https://patch.msgid.link/20251215111300.132803-1-dedekind1@gmail.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Make intel_idle_init() call arch_cpu_rescan_dead_smt_siblings() after
successfully registering intel_idle as the cpuidle driver so as to
allow the "dead" SMT siblings (if any) to go into deep idle states.
This is necessary for the processor to be able to reach deep package
C-states (like PC10) going forward which is requisite for reducing
power sufficiently in suspend-to-idle, among other things.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Link: https://patch.msgid.link/10669885.nUPlyArG6x@rjwysocki.net
It is not necessary to wait until the device_initcall() stage with
intel_idle initialization. All of its dependencies are met after
all subsys_initcall()s have run, so subsys_initcall_sync() can be
used for initializing it.
It is also better to ensure that intel_idle will always initialize
before the ACPI processor driver that uses module_init() for its
initialization.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Link: https://patch.msgid.link/2994397.e9J7NaK4W3@rjwysocki.net
Pull power management updates from Rafael Wysocki:
"Once again, the changes are dominated by cpufreq updates, but this
time the majority of them are cpufreq core changes, mostly related to
the introduction of policy locking guards and __free() usage, and
fixes related to boost handling.
Still, there is also a significant update of the intel_pstate driver
making it register an energy model when running on a hybrid platform
which is used for enabling energy-aware scheduling (EAS) if the driver
operates in the passive mode (and schedutil is used as the cpufreq
governor for all CPUs which is the passive mode default).
There are some amd-pstate driver updates too, for a good measure,
including the "Requested CPU Min frequency" BIOS option support and
new online/offline callbacks.
In the cpuidle space, the most significant change is the addition of a
C1 demotion on/off sysfs knob to intel_idle which should help some
users to configure their systems more precisely. There is also the
conversion of the PSCI cpuidle driver to a faux device one and there
are two small updates of cpuidle governors.
Device power management is also modified quite a bit, especially the
handling of devices with asynchronous suspend and resume enabled
during system transitions. They are now going to be handled more
asynchronously during suspend transitions and somewhat less
aggressively during resume transitions.
Apart from the above, the operating performance points (OPP) library
is now going to use mutex locking guards and scope-based cleanup
helpers and there is the usual bunch of assorted fixes and code
cleanups.
Specifics:
- Fix potential division-by-zero error in em_compute_costs() (Yaxiong
Tian)
- Fix typos in energy model documentation and example driver code
(Moon Hee Lee, Atul Kumar Pant)
- Rearrange the energy model management code and add a new function
for adjusting a CPU energy model after adjusting the capacity of
the given CPU to it (Rafael Wysocki)
- Refactor cpufreq_online(), add and use cpufreq policy locking
guards, use __free() in policy reference counting, and clean up
core cpufreq code on top of that (Rafael Wysocki)
- Fix boost handling on CPU suspend/resume and sysfs updates (Viresh
Kumar)
- Fix des_perf clamping with max_perf in amd_pstate_update()
(Dhananjay Ugwekar)
- Add offline, online and suspend callbacks to the amd-pstate driver,
rename and use the existing amd_pstate_epp callbacks in it
(Dhananjay Ugwekar)
- Add support for the "Requested CPU Min frequency" BIOS option to
the amd-pstate driver (Dhananjay Ugwekar)
- Reset amd-pstate driver mode after running selftests (Swapnil
Sapkal)
- Avoid shadowing ret in amd_pstate_ut_check_driver() (Nathan
Chancellor)
- Add helper for governor checks to the schedutil cpufreq governor
and move cpufreq-specific EAS checks to cpufreq (Rafael Wysocki)
- Populate the cpu_capacity sysfs entries from the intel_pstate
driver after registering asym capacity support (Ricardo Neri)
- Add support for enabling Energy-aware scheduling (EAS) to the
intel_pstate driver when operating in the passive mode on a hybrid
platform (Rafael Wysocki)
- Drop redundant cpus_read_lock() from store_local_boost() in the
cpufreq core (Seyediman Seyedarab)
- Replace sscanf() with kstrtouint() in the cpufreq code and use a
symbol instead of a raw number in it (Bowen Yu)
- Add support for autonomous CPU performance state selection to the
CPPC cpufreq driver (Lifeng Zheng)
- OPP: Add dev_pm_opp_set_level() (Praveen Talari)
- Introduce scope-based cleanup headers and mutex locking guards in
OPP core (Viresh Kumar)
- Switch OPP to use kmemdup_array() (Zhang Enpei)
- Optimize bucket assignment when next_timer_ns equals KTIME_MAX in
the menu cpuidle governor (Zhongqiu Han)
- Convert the cpuidle PSCI driver to a faux device one (Sudeep Holla)
- Add C1 demotion on/off sysfs knob to the intel_idle driver (Artem
Bityutskiy)
- Fix typos in two comments in the teo cpuidle governor (Atul Kumar
Pant)
- Fix denying of auto suspend in pm_suspend_timer_fn() (Charan Teja
Kalla)
- Move debug runtime PM attributes to runtime_attrs[] (Rafael
Wysocki)
- Add new devm_ functions for enabling runtime PM and runtime PM
reference counting (Bence Csókás)
- Remove size arguments from strscpy() calls in the hibernation core
code (Thorsten Blum)
- Adjust the handling of devices with asynchronous suspend enabled
during system suspend and resume to start resuming them immediately
after resuming their parents and to start suspending such a device
immediately after suspending its first child (Rafael Wysocki)
- Adjust messages printed during tasks freezing to avoid using
pr_cont() (Andrew Sayers, Paul Menzel)
- Clean up unnecessary usage of !! in pm_print_times_init() (Zihuan
Zhang)
- Add missing wakeup source attribute relax_count to sysfs and remove
the space character at the end ofi the string produced by
pm_show_wakelocks() (Zijun Hu)
- Add configurable pm_test delay for hibernation (Zihuan Zhang)
- Disable asynchronous suspend in ucsi_ccg_probe() to prevent the
cypd4226 device on Tegra boards from suspending prematurely (Jon
Hunter)
- Unbreak printing PM debug messages during hibernation and clean up
some related code (Rafael Wysocki)
- Add a systemd service to run cpupower and change cpupower binding's
Makefile to use -lcpupower (John B. Wyatt IV, Francesco Poli)"
* tag 'pm-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (72 commits)
cpufreq: CPPC: Add support for autonomous selection
cpufreq: Update sscanf() to kstrtouint()
cpufreq: Replace magic number
OPP: switch to use kmemdup_array()
PM: freezer: Rewrite restarting tasks log to remove stray *done.*
PM: runtime: fix denying of auto suspend in pm_suspend_timer_fn()
cpufreq: drop redundant cpus_read_lock() from store_local_boost()
cpupower: do not install files to /etc/default/
cpupower: do not call systemctl at install time
cpupower: do not write DESTDIR to cpupower.service
PM: sleep: Introduce pm_sleep_transition_in_progress()
cpufreq/amd-pstate: Avoid shadowing ret in amd_pstate_ut_check_driver()
cpufreq: intel_pstate: Document hybrid processor support
cpufreq: intel_pstate: EAS: Increase cost for CPUs using L3 cache
cpufreq: intel_pstate: EAS support for hybrid platforms
PM: EM: Introduce em_adjust_cpu_capacity()
PM: EM: Move CPU capacity check to em_adjust_new_capacity()
PM: EM: Documentation: Fix typos in example driver code
cpufreq: Drop policy locking from cpufreq_policy_is_good_for_eas()
PM: sleep: Introduce pm_suspend_in_progress()
...
The main CPUID header <asm/cpuid.h> was originally a storefront for the
headers:
<asm/cpuid/api.h>
<asm/cpuid/leaf_0x2_api.h>
Now that the latter CPUID(0x2) header has been merged into the former,
there is no practical difference between <asm/cpuid.h> and
<asm/cpuid/api.h>.
Migrate all users to the <asm/cpuid/api.h> header, in preparation of
the removal of <asm/cpuid.h>.
Don't remove <asm/cpuid.h> just yet, in case some new code in -next
started using it.
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: x86-cpuid@lists.linux.dev
Link: https://lore.kernel.org/r/20250508150240.172915-3-darwi@linutronix.de
Add a sysfs knob to enable/disable C1 demotion for the following Intel
platforms: Sapphire Rapids Xeon, Emerald Rapids Xeon, Granite Rapids Xeon,
Sierra Forest Xeon, and Grand Ridge SoC.
This sysfs file shows up as
"/sys/devices/system/cpu/cpuidle/intel_c1_demotion".
The C1 demotion feature involves the platform firmware demoting deep
C-state requests from the OS (e.g., C6 requests) to C1. The idea is
that firmware monitors CPU wake-up rate, and if it is higher than a
platform-specific threshold, the firmware demotes deep C-state
requests to C1. For example, Linux requests C6, but firmware noticed
too many wake-ups per second, and it keeps the CPU in C1. When the
CPU stays in C1 long enough, the platform promotes it back to C6.
The default value for C1 demotion is whatever is configured by BIOS.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Link: https://patch.msgid.link/20250317135541.1471754-2-dedekind1@gmail.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull power management updates from Rafael Wysocki:
"These are dominated by cpufreq updates which in turn are dominated by
updates related to boost support in the core and drivers and
amd-pstate driver optimizations.
Apart from the above, there are some cpuidle updates including a
rework of the most recent idle intervals handling in the venerable
menu governor that leads to significant improvements in some
performance benchmarks, as the governor is now more likely to predict
a shorter idle duration in some cases, and there are updates of the
core device power management code, mostly related to system suspend
and resume, that should help to avoid potential issues arising when
the drivers of devices depending on one another want to use different
optimizations.
There is also a usual collection of assorted fixes and cleanups,
including removal of some unused code.
Specifics:
- Manage sysfs attributes and boost frequencies efficiently from
cpufreq core to reduce boilerplate code in drivers (Viresh Kumar)
- Minor cleanups to cpufreq drivers (Aaron Kling, Benjamin Schneider,
Dhananjay Ugwekar, Imran Shaik, zuoqian)
- Migrate some cpufreq drivers to using for_each_present_cpu() (Jacky
Bai)
- cpufreq-qcom-hw DT binding fixes (Krzysztof Kozlowski)
- Use str_enable_disable() helper in cpufreq_online() (Lifeng Zheng)
- Optimize the amd-pstate driver to avoid cases where call paths end
up calling the same writes multiple times and needlessly caching
variables through code reorganization, locking overhaul and tracing
adjustments (Mario Limonciello, Dhananjay Ugwekar)
- Make it possible to avoid enabling capacity-aware scheduling (CAS)
in the intel_pstate driver and relocate a check for out-of-band
(OOB) platform handling in it to make it detect OOB before checking
HWP availability (Rafael Wysocki)
- Fix dbs_update() to avoid inadvertent conversions of negative
integer values to unsigned int which causes CPU frequency selection
to be inaccurate in some cases when the "conservative" cpufreq
governor is in use (Jie Zhan)
- Update the handling of the most recent idle intervals in the menu
cpuidle governor to prevent useful information from being discarded
by it in some cases and improve the prediction accuracy (Rafael
Wysocki)
- Make it possible to tell the intel_idle driver to ignore its
built-in table of idle states for the given processor, clean up the
handling of auto-demotion disabling on Baytrail and Cherrytrail
chips in it, and update its MAINTAINERS entry (David Arcari, Artem
Bityutskiy, Rafael Wysocki)
- Make some cpuidle drivers use for_each_present_cpu() instead of
for_each_possible_cpu() during initialization to avoid issues
occurring when nosmp or maxcpus=0 are used (Jacky Bai)
- Clean up the Energy Model handling code somewhat (Rafael Wysocki)
- Use kfree_rcu() to simplify the handling of runtime Energy Model
updates (Li RongQing)
- Add an entry for the Energy Model framework to MAINTAINERS as
properly maintained (Lukasz Luba)
- Address RCU-related sparse warnings in the Energy Model code
(Rafael Wysocki)
- Remove ENERGY_MODEL dependency on SMP and allow it to be selected
when DEVFREQ is set without CPUFREQ so it can be used on a wider
range of systems (Jeson Gao)
- Unify error handling during runtime suspend and runtime resume in
the core to help drivers to implement more consistent runtime PM
error handling (Rafael Wysocki)
- Drop a redundant check from pm_runtime_force_resume() and rearrange
documentation related to __pm_runtime_disable() (Rafael Wysocki)
- Rework the handling of the "smart suspend" driver flag in the PM
core to avoid issues hat may occur when drivers using it depend on
some other drivers and clean up the related PM core code (Rafael
Wysocki, Colin Ian King)
- Fix the handling of devices with the power.direct_complete flag set
if device_suspend() returns an error for at least one device to
avoid situations in which some of them may not be resumed (Rafael
Wysocki)
- Use mutex_trylock() in hibernate_compressor_param_set() to avoid a
possible deadlock that may occur if the "compressor" hibernation
module parameter is accessed during the registration of a new
ieee80211 device (Lizhi Xu)
- Suppress sleeping parent warning in device_pm_add() in the case
when new children are added under a device with the
power.direct_complete set after it has been processed by
device_resume() (Xu Yang)
- Remove needless return in three void functions related to system
wakeup (Zijun Hu)
- Replace deprecated kmap_atomic() with kmap_local_page() in the
hibernation core code (David Reaver)
- Remove unused helper functions related to system sleep (David Alan
Gilbert)
- Clean up s2idle_enter() so it does not lock and unlock CPU offline
in vain and update comments in it (Ulf Hansson)
- Clean up broken white space in dpm_wait_for_children() (Geert
Uytterhoeven)
- Update the cpupower utility to fix lib version-ing in it and memory
leaks in error legs, remove hard-coded values, and implement CPU
physical core querying (Thomas Renninger, John B. Wyatt IV, Shuah
Khan, Yiwei Lin, Zhongqiu Han)"
* tag 'pm-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (139 commits)
PM: sleep: Fix bit masking operation
dt-bindings: cpufreq: cpufreq-qcom-hw: Narrow properties on SDX75, SA8775p and SM8650
dt-bindings: cpufreq: cpufreq-qcom-hw: Drop redundant minItems:1
dt-bindings: cpufreq: cpufreq-qcom-hw: Add missing constraint for interrupt-names
dt-bindings: cpufreq: cpufreq-qcom-hw: Add QCS8300 compatible
cpufreq: Init cpufreq only for present CPUs
PM: sleep: Fix handling devices with direct_complete set on errors
cpuidle: Init cpuidle only for present CPUs
PM: clk: Remove unused pm_clk_remove()
PM: sleep: core: Fix indentation in dpm_wait_for_children()
PM: s2idle: Extend comment in s2idle_enter()
PM: s2idle: Drop redundant locks when entering s2idle
PM: sleep: Remove unused pm_generic_ wrappers
cpufreq: tegra186: Share policy per cluster
cpupower: Make lib versioning scheme more obvious and fix version link
PM: EM: Rework the depends on for CONFIG_ENERGY_MODEL
PM: EM: Address RCU-related sparse warnings
cpupower: Implement CPU physical core querying
pm: cpupower: remove hard-coded topology depth values
pm: cpupower: Fix cmd_monitor() error legs to free cpu_topology
...
Pull core x86 updates from Ingo Molnar:
"x86 CPU features support:
- Generate the <asm/cpufeaturemasks.h> header based on build config
(H. Peter Anvin, Xin Li)
- x86 CPUID parsing updates and fixes (Ahmed S. Darwish)
- Introduce the 'setcpuid=' boot parameter (Brendan Jackman)
- Enable modifying CPU bug flags with '{clear,set}puid=' (Brendan
Jackman)
- Utilize CPU-type for CPU matching (Pawan Gupta)
- Warn about unmet CPU feature dependencies (Sohil Mehta)
- Prepare for new Intel Family numbers (Sohil Mehta)
Percpu code:
- Standardize & reorganize the x86 percpu layout and related cleanups
(Brian Gerst)
- Convert the stackprotector canary to a regular percpu variable
(Brian Gerst)
- Add a percpu subsection for cache hot data (Brian Gerst)
- Unify __pcpu_op{1,2}_N() macros to __pcpu_op_N() (Uros Bizjak)
- Construct __percpu_seg_override from __percpu_seg (Uros Bizjak)
MM:
- Add support for broadcast TLB invalidation using AMD's INVLPGB
instruction (Rik van Riel)
- Rework ROX cache to avoid writable copy (Mike Rapoport)
- PAT: restore large ROX pages after fragmentation (Kirill A.
Shutemov, Mike Rapoport)
- Make memremap(MEMREMAP_WB) map memory as encrypted by default
(Kirill A. Shutemov)
- Robustify page table initialization (Kirill A. Shutemov)
- Fix flush_tlb_range() when used for zapping normal PMDs (Jann Horn)
- Clear _PAGE_DIRTY for kernel mappings when we clear _PAGE_RW
(Matthew Wilcox)
KASLR:
- x86/kaslr: Reduce KASLR entropy on most x86 systems, to support PCI
BAR space beyond the 10TiB region (CONFIG_PCI_P2PDMA=y) (Balbir
Singh)
CPU bugs:
- Implement FineIBT-BHI mitigation (Peter Zijlstra)
- speculation: Simplify and make CALL_NOSPEC consistent (Pawan Gupta)
- speculation: Add a conditional CS prefix to CALL_NOSPEC (Pawan
Gupta)
- RFDS: Exclude P-only parts from the RFDS affected list (Pawan
Gupta)
System calls:
- Break up entry/common.c (Brian Gerst)
- Move sysctls into arch/x86 (Joel Granados)
Intel LAM support updates: (Maciej Wieczor-Retman)
- selftests/lam: Move cpu_has_la57() to use cpuinfo flag
- selftests/lam: Skip test if LAM is disabled
- selftests/lam: Test get_user() LAM pointer handling
AMD SMN access updates:
- Add SMN offsets to exclusive region access (Mario Limonciello)
- Add support for debugfs access to SMN registers (Mario Limonciello)
- Have HSMP use SMN through AMD_NODE (Yazen Ghannam)
Power management updates: (Patryk Wlazlyn)
- Allow calling mwait_play_dead with an arbitrary hint
- ACPI/processor_idle: Add FFH state handling
- intel_idle: Provide the default enter_dead() handler
- Eliminate mwait_play_dead_cpuid_hint()
Build system:
- Raise the minimum GCC version to 8.1 (Brian Gerst)
- Raise the minimum LLVM version to 15.0.0 (Nathan Chancellor)
Kconfig: (Arnd Bergmann)
- Add cmpxchg8b support back to Geode CPUs
- Drop 32-bit "bigsmp" machine support
- Rework CONFIG_GENERIC_CPU compiler flags
- Drop configuration options for early 64-bit CPUs
- Remove CONFIG_HIGHMEM64G support
- Drop CONFIG_SWIOTLB for PAE
- Drop support for CONFIG_HIGHPTE
- Document CONFIG_X86_INTEL_MID as 64-bit-only
- Remove old STA2x11 support
- Only allow CONFIG_EISA for 32-bit
Headers:
- Replace __ASSEMBLY__ with __ASSEMBLER__ in UAPI and non-UAPI
headers (Thomas Huth)
Assembly code & machine code patching:
- x86/alternatives: Simplify alternative_call() interface (Josh
Poimboeuf)
- x86/alternatives: Simplify callthunk patching (Peter Zijlstra)
- KVM: VMX: Use named operands in inline asm (Josh Poimboeuf)
- x86/hyperv: Use named operands in inline asm (Josh Poimboeuf)
- x86/traps: Cleanup and robustify decode_bug() (Peter Zijlstra)
- x86/kexec: Merge x86_32 and x86_64 code using macros from
<asm/asm.h> (Uros Bizjak)
- Use named operands in inline asm (Uros Bizjak)
- Improve performance by using asm_inline() for atomic locking
instructions (Uros Bizjak)
Earlyprintk:
- Harden early_serial (Peter Zijlstra)
NMI handler:
- Add an emergency handler in nmi_desc & use it in
nmi_shootdown_cpus() (Waiman Long)
Miscellaneous fixes and cleanups:
- by Ahmed S. Darwish, Andy Shevchenko, Ard Biesheuvel, Artem
Bityutskiy, Borislav Petkov, Brendan Jackman, Brian Gerst, Dan
Carpenter, Dr. David Alan Gilbert, H. Peter Anvin, Ingo Molnar,
Josh Poimboeuf, Kevin Brodsky, Mike Rapoport, Lukas Bulwahn, Maciej
Wieczor-Retman, Max Grobecker, Patryk Wlazlyn, Pawan Gupta, Peter
Zijlstra, Philip Redkin, Qasim Ijaz, Rik van Riel, Thomas Gleixner,
Thorsten Blum, Tom Lendacky, Tony Luck, Uros Bizjak, Vitaly
Kuznetsov, Xin Li, liuye"
* tag 'x86-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (211 commits)
zstd: Increase DYNAMIC_BMI2 GCC version cutoff from 4.8 to 11.0 to work around compiler segfault
x86/asm: Make asm export of __ref_stack_chk_guard unconditional
x86/mm: Only do broadcast flush from reclaim if pages were unmapped
perf/x86/intel, x86/cpu: Replace Pentium 4 model checks with VFM ones
perf/x86/intel, x86/cpu: Simplify Intel PMU initialization
x86/headers: Replace __ASSEMBLY__ with __ASSEMBLER__ in non-UAPI headers
x86/headers: Replace __ASSEMBLY__ with __ASSEMBLER__ in UAPI headers
x86/locking/atomic: Improve performance by using asm_inline() for atomic locking instructions
x86/asm: Use asm_inline() instead of asm() in clwb()
x86/asm: Use CLFLUSHOPT and CLWB mnemonics in <asm/special_insns.h>
x86/hweight: Use asm_inline() instead of asm()
x86/hweight: Use ASM_CALL_CONSTRAINT in inline asm()
x86/hweight: Use named operands in inline asm()
x86/stackprotector/64: Only export __ref_stack_chk_guard on CONFIG_SMP
x86/head/64: Avoid Clang < 17 stack protector in startup code
x86/kexec: Merge x86_32 and x86_64 code using macros from <asm/asm.h>
x86/runtime-const: Add the RUNTIME_CONST_PTR assembly macro
x86/cpu/intel: Limit the non-architectural constant_tsc model checks
x86/mm/pat: Replace Intel x86_model checks with VFM ones
x86/cpu/intel: Fix fast string initialization for extended Families
...
CONFIG_TRACE_BRANCH_PROFILING inserts a call to ftrace_likely_update()
for each use of likely() or unlikely(). That breaks noinstr rules if
the affected function is annotated as noinstr.
Disable branch profiling for files with noinstr functions. In addition
to some individual files, this also includes the entire arch/x86
subtree, as well as the kernel/entry, drivers/cpuidle, and drivers/idle
directories, all of which are noinstr-heavy.
Due to the nature of how sched binaries are built by combining multiple
.c files into one, branch profiling is disabled more broadly across the
sched code than would otherwise be needed.
This fixes many warnings like the following:
vmlinux.o: warning: objtool: do_syscall_64+0x40: call to ftrace_likely_update() leaves .noinstr.text section
vmlinux.o: warning: objtool: __rdgsbase_inactive+0x33: call to ftrace_likely_update() leaves .noinstr.text section
vmlinux.o: warning: objtool: handle_bug.isra.0+0x198: call to ftrace_likely_update() leaves .noinstr.text section
...
Reported-by: Ingo Molnar <mingo@kernel.org>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/fb94fc9303d48a5ed370498f54500cc4c338eb6d.1742586676.git.jpoimboe@kernel.org
The Intel idle driver is preferred over the ACPI processor idle driver,
but fails to implement the work around for Core2 generation CPUs, where
the TSC stops in C2 and deeper C-states. This causes stalls and boot
delays, when the clocksource watchdog does not catch the unstable TSC
before the CPU goes deep idle for the first time.
The ACPI driver marks the TSC unstable when it detects that the CPU
supports C2 or deeper and the CPU does not have a non-stop TSC.
Add the equivivalent work around to the Intel idle driver to cure that.
Fixes: 18734958e9 ("intel_idle: Use ACPI _CST for processor models without C-state tables")
Reported-by: Fab Stz <fabstz-it@yahoo.fr>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Fab Stz <fabstz-it@yahoo.fr>
Cc: All applicable <stable@vger.kernel.org>
Closes: https://lore.kernel.org/all/10cf96aa-1276-4bd4-8966-c890377030c3@yahoo.fr
Link: https://patch.msgid.link/87bjupfy7f.ffs@tglx
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Since commit 18734958e9 ("intel_idle: Use ACPI _CST for processor models
without C-state tables") the intel_idle driver has had the ability to use
the ACPI _CST to populate C-states when the processor model is not
recognized.
However, even when the processor model is recognized (native mode) there
are cases where it is useful to make the driver ignore the per-CPU idle
states in lieu of ACPI C-states (such as specific application performance).
Add a new 'no_native' module parameter to provide this functionality.
Signed-off-by: David Arcari <darcari@redhat.com>
Link: https://patch.msgid.link/20250220151120.1131122-1-darcari@redhat.com
Reviewed-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
[ rjw: Spell CPU in capitals ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Bay Trail (BYT) and Cherry Trail (CHT) platforms have a very specific way
of disabling auto-demotion via specific MSR bits. Clean up the code so that
BYT/CHT-specifics do not show up in the common 'struct idle_cpu' data
structure.
Remove the 'byt_auto_demotion_disable_flag' flag from 'struct idle_cpu',
because a better coding pattern is to avoid very case-specific fields like
'bool byt_auto_demotion_disable_flag' in a common data structure, which is
used for all platforms, not only BYT/CHT. The code is just more readable
when common data structures contain only commonly used fields.
Instead, match BYT/CHT in the 'intel_idle_init_cstates_icpu()' function,
and introduce a small helper to take care of BYT/CHT auto-demotion. This
is consistent with how platform-specific things are done for other
platforms.
No intended functional changes, compile-tested only.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Link: https://patch.msgid.link/20250210071253.2991030-1-dedekind1@gmail.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
