Linux kernel source tree
Go to file
Linus Torvalds d7c8087a9c Power management updates for 7.1-rc1
- Update qcom-hw DT bindings to include Eliza hardware (Abel Vesa)
 
  - Update cpufreq-dt-platdev blocklist (Faruque Ansari)
 
  - Minor updates to driver and dt-bindings for Tegra (Thierry Reding,
    Rosen Penev)
 
  - Add MAINTAINERS entry for CPPC driver (Viresh Kumar)
 
  - Add support for new features: CPPC performance priority, Dynamic EPP,
    Raw EPP, and new unit tests for them to amd-pstate (Gautham Shenoy,
    Mario Limonciello)
 
  - Fix sysfs files being present when HW missing and broken/outdated
    documentation in the amd-pstate driver (Ninad Naik, Gautham Shenoy)
 
  - Pass the policy to cpufreq_driver->adjust_perf() to avoid using
    cpufreq_cpu_get() in the .adjust_perf() callback in amd-pstate which
    leads to a scheduling-while-atomic bug (K Prateek Nayak)
 
  - Clean up dead code in Kconfig for cpufreq (Julian Braha)
 
  - Remove max_freq_req update for pre-existing cpufreq policy and add a
    boost_freq_req QoS request to save the boost constraint instead of
    overwriting the last scaling_max_freq constraint (Pierre Gondois)
 
  - Embed cpufreq QoS freq_req objects in cpufreq policy so they all
    are allocated in one go along with the policy to simplify lifetime
    rules and avoid error handling issues (Viresh Kumar)
 
  - Use DMI max speed when CPPC is unavailable in the acpi-cpufreq
    scaling driver (Henry Tseng)
 
  - Switch policy_is_shared() in cpufreq to using cpumask_nth() instead
    of cpumask_weight() because the former is more efficient (Yury Norov)
 
  - Use sysfs_emit() in sysfs show functions for cpufreq governor
    attributes (Thorsten Blum)
 
  - Update intel_pstate to stop returning an error when "off" is written
    to its status sysfs attribute while the driver is already off (Fabio
    De Francesco)
 
  - Include current frequency in the debug message printed by
    __cpufreq_driver_target() (Pengjie Zhang)
 
  - Refine stopped tick handling in the menu cpuidle governor and
    rearrange stopped tick handling in the teo cpuidle governor (Rafael
    Wysocki)
 
  - Add Panther Lake C-states table to the intel_idle driver (Artem
    Bityutskiy)
 
  - Clean up dead dependencies on CPU_IDLE in Kconfig (Julian Braha)
 
  - Simplify cpuidle_register_device() with guard() (Huisong Li)
 
  - Use performance level if available to distinguish between rates in
    OPP debugfs (Manivannan Sadhasivam)
 
  - Fix scoped_guard in dev_pm_opp_xlate_required_opp() (Viresh Kumar)
 
  - Return -ENODATA if the snapshot image is not loaded (Alberto Garcia)
 
  - Remove inclusion of crypto/hash.h from hibernate_64.c on x86 (Eric
    Biggers)
 
  - Clean up and rearrange the intel_rapl power capping driver to make
    the respective interface drivers (TPMI, MSR, and MMOI) hold their
    own settings and primitives and consolidate PL4 and PMU support
    flags into rapl_defaults (Kuppuswamy Sathyanarayanan)
 
  - Correct kernel-doc function parameter names in the power capping core
    code (Randy Dunlap)
 
  - Remove unneeded casting for HZ_PER_KHZ in devfreq (Andy Shevchenko)
 
  - Use _visible attribute to replace create/remove_sysfs_files() in
    devfreq (Pengjie Zhang)
 
  - Add Tegra114 support to activity monitor device in tegra30-devfreq as
    a preparation to upcoming EMC controller support (Svyatoslav Ryhel)
 
  - Fix mistakes in cpupower man pages, add the boost and epp options to
    the cpupower-frequency-info man page, and add the perf-bias option to
    the cpupower-info man page (Roberto Ricci)
 
  - Remove unnecessary extern declarations from getopt.h in arguments
    parsing functions in cpufreq-set, cpuidle-info, cpuidle-set,
    cpupower-info, and cpupower-set utilities (Kaushlendra Kumar)
 -----BEGIN PGP SIGNATURE-----
 
 iQFGBAABCAAwFiEEcM8Aw/RY0dgsiRUR7l+9nS/U47UFAmnY9TISHHJqd0Byand5
 c29ja2kubmV0AAoJEO5fvZ0v1OO1G9gH/j5mEqfPpiwX6fQ/ZwOGdNOOPVA5w9j4
 KPHSMwMD5lZkoaZfasp2vt27KY5SOoVVvRZ2DKkFJ3Jai4I3cUPZYypga2nre1ag
 tgzX4vOjcw2r40Eda6ezWl1h4mca/xJJBX7xH2+hn1JY+Y1in37g50CqMIjKh96z
 Uugkk6UZytL1XcF55PMhIUgDf6pDtRT5UOW9xOKOkUt8FVWTJ7ei3HaWyV5kDmVq
 b5eQ42+OH7y6sWNnoKczFd8fStvh6J/avoJurBEvcOQhMcjaIaB48G19+KjDg73E
 NjrVcgG20P2rltBvV2d0J1TKskZHkaP7XjIeWfkwjGZhee3FL7ssS/g=
 =fRCO
 -----END PGP SIGNATURE-----

Merge tag 'pm-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management updates from Rafael Wysocki:
 "Once again, cpufreq is the most active development area, mostly
  because of the new feature additions and documentation updates in the
  amd-pstate driver, but there are also changes in the cpufreq core
  related to boost support and other assorted updates elsewhere.

  Next up are power capping changes due to the major cleanup of the
  Intel RAPL driver.

  On the cpuidle front, a new C-states table for Intel Panther Lake is
  added to the intel_idle driver, the stopped tick handling in the menu
  and teo governors is updated, and there are a couple of cleanups.

  Apart from the above, support for Tegra114 is added to devfreq and
  there are assorted cleanups of that code, there are also two updates
  of the operating performance points (OPP) library, two minor updates
  related to hibernation, and cpupower utility man pages updates and
  cleanups.

  Specifics:

   - Update qcom-hw DT bindings to include Eliza hardware (Abel Vesa)

   - Update cpufreq-dt-platdev blocklist (Faruque Ansari)

   - Minor updates to driver and dt-bindings for Tegra (Thierry Reding,
     Rosen Penev)

   - Add MAINTAINERS entry for CPPC driver (Viresh Kumar)

   - Add support for new features: CPPC performance priority, Dynamic
     EPP, Raw EPP, and new unit tests for them to amd-pstate (Gautham
     Shenoy, Mario Limonciello)

   - Fix sysfs files being present when HW missing and broken/outdated
     documentation in the amd-pstate driver (Ninad Naik, Gautham Shenoy)

   - Pass the policy to cpufreq_driver->adjust_perf() to avoid using
     cpufreq_cpu_get() in the .adjust_perf() callback in amd-pstate
     which leads to a scheduling-while-atomic bug (K Prateek Nayak)

   - Clean up dead code in Kconfig for cpufreq (Julian Braha)

   - Remove max_freq_req update for pre-existing cpufreq policy and add
     a boost_freq_req QoS request to save the boost constraint instead
     of overwriting the last scaling_max_freq constraint (Pierre
     Gondois)

   - Embed cpufreq QoS freq_req objects in cpufreq policy so they all
     are allocated in one go along with the policy to simplify lifetime
     rules and avoid error handling issues (Viresh Kumar)

   - Use DMI max speed when CPPC is unavailable in the acpi-cpufreq
     scaling driver (Henry Tseng)

   - Switch policy_is_shared() in cpufreq to using cpumask_nth() instead
     of cpumask_weight() because the former is more efficient (Yury
     Norov)

   - Use sysfs_emit() in sysfs show functions for cpufreq governor
     attributes (Thorsten Blum)

   - Update intel_pstate to stop returning an error when "off" is
     written to its status sysfs attribute while the driver is already
     off (Fabio De Francesco)

   - Include current frequency in the debug message printed by
     __cpufreq_driver_target() (Pengjie Zhang)

   - Refine stopped tick handling in the menu cpuidle governor and
     rearrange stopped tick handling in the teo cpuidle governor (Rafael
     Wysocki)

   - Add Panther Lake C-states table to the intel_idle driver (Artem
     Bityutskiy)

   - Clean up dead dependencies on CPU_IDLE in Kconfig (Julian Braha)

   - Simplify cpuidle_register_device() with guard() (Huisong Li)

   - Use performance level if available to distinguish between rates in
     OPP debugfs (Manivannan Sadhasivam)

   - Fix scoped_guard in dev_pm_opp_xlate_required_opp() (Viresh Kumar)

   - Return -ENODATA if the snapshot image is not loaded (Alberto
     Garcia)

   - Remove inclusion of crypto/hash.h from hibernate_64.c on x86 (Eric
     Biggers)

   - Clean up and rearrange the intel_rapl power capping driver to make
     the respective interface drivers (TPMI, MSR, and MMOI) hold their
     own settings and primitives and consolidate PL4 and PMU support
     flags into rapl_defaults (Kuppuswamy Sathyanarayanan)

   - Correct kernel-doc function parameter names in the power capping
     core code (Randy Dunlap)

   - Remove unneeded casting for HZ_PER_KHZ in devfreq (Andy Shevchenko)

   - Use _visible attribute to replace create/remove_sysfs_files() in
     devfreq (Pengjie Zhang)

   - Add Tegra114 support to activity monitor device in tegra30-devfreq
     as a preparation to upcoming EMC controller support (Svyatoslav
     Ryhel)

   - Fix mistakes in cpupower man pages, add the boost and epp options
     to the cpupower-frequency-info man page, and add the perf-bias
     option to the cpupower-info man page (Roberto Ricci)

   - Remove unnecessary extern declarations from getopt.h in arguments
     parsing functions in cpufreq-set, cpuidle-info, cpuidle-set,
     cpupower-info, and cpupower-set utilities (Kaushlendra Kumar)"

* tag 'pm-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (74 commits)
  cpufreq/amd-pstate: Add POWER_SUPPLY select for dynamic EPP
  cpupower: remove extern declarations in cmd functions
  cpuidle: Simplify cpuidle_register_device() with guard()
  PM / devfreq: tegra30-devfreq: add support for Tegra114
  PM / devfreq: use _visible attribute to replace create/remove_sysfs_files()
  PM / devfreq: Remove unneeded casting for HZ_PER_KHZ
  MAINTAINERS: amd-pstate: Step down as maintainer, add Prateek as reviewer
  cpufreq: Pass the policy to cpufreq_driver->adjust_perf()
  cpufreq/amd-pstate: Pass the policy to amd_pstate_update()
  cpufreq/amd-pstate-ut: Add a unit test for raw EPP
  cpufreq/amd-pstate: Add support for raw EPP writes
  cpufreq/amd-pstate: Add support for platform profile class
  cpufreq/amd-pstate: add kernel command line to override dynamic epp
  cpufreq/amd-pstate: Add dynamic energy performance preference
  Documentation: amd-pstate: fix dead links in the reference section
  cpufreq/amd-pstate: Cache the max frequency in cpudata
  Documentation/amd-pstate: Add documentation for amd_pstate_floor_{freq,count}
  Documentation/amd-pstate: List amd_pstate_prefcore_ranking sysfs file
  Documentation/amd-pstate: List amd_pstate_hw_prefcore sysfs file
  amd-pstate-ut: Add a testcase to validate the visibility of driver attributes
  ...
2026-04-13 19:47:52 -07:00
arch Power management updates for 7.1-rc1 2026-04-13 19:47:52 -07:00
block for-7.1/block-20260411 2026-04-13 15:51:31 -07:00
certs Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
crypto CRC updates for 7.1 2026-04-13 17:36:04 -07:00
Documentation Power management updates for 7.1-rc1 2026-04-13 19:47:52 -07:00
drivers Power management updates for 7.1-rc1 2026-04-13 19:47:52 -07:00
fs Driver core changes for 7.1-rc1 2026-04-13 19:03:11 -07:00
include Power management updates for 7.1-rc1 2026-04-13 19:47:52 -07:00
init Driver core changes for 7.1-rc1 2026-04-13 19:03:11 -07:00
io_uring for-7.1/io_uring-20260411 2026-04-13 16:22:30 -07:00
ipc Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
kernel Power management updates for 7.1-rc1 2026-04-13 19:47:52 -07:00
lib CRC updates for 7.1 2026-04-13 17:36:04 -07:00
LICENSES LICENSES: Add modern form of the LGPL-2.1 tags to the usage guide section 2025-10-22 07:58:19 +02:00
mm for-7.1/block-20260411 2026-04-13 15:51:31 -07:00
net Crypto library updates for 7.1 2026-04-13 17:31:39 -07:00
rust Power management updates for 7.1-rc1 2026-04-13 19:47:52 -07:00
samples Driver core changes for 7.1-rc1 2026-04-13 19:03:11 -07:00
scripts Driver core changes for 7.1-rc1 2026-04-13 19:03:11 -07:00
security Crypto library updates for 7.1 2026-04-13 17:31:39 -07:00
sound ASoC: Fixes for v7.0 2026-04-09 07:00:53 +02:00
tools Power management updates for 7.1-rc1 2026-04-13 19:47:52 -07:00
usr kbuild: uapi: drop dependency on CC_CAN_LINK 2026-01-16 15:02:11 -07:00
virt vfs-7.1-rc1.bh.metadata 2026-04-13 12:46:42 -07:00
.clang-format Devicetree updates for v7.0: 2026-02-11 18:27:08 -08:00
.clippy.toml rust: bump Clippy's MSRV and clean incompatible_msrv allows 2026-04-07 09:51:39 +02:00
.cocciconfig
.editorconfig editorconfig: add rst extension 2026-01-26 19:07:09 -08:00
.get_maintainer.ignore .get_maintainer.ignore: add myself 2026-04-02 16:48:25 +02:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: rust: provide an option to inline C helpers into Rust 2026-03-30 02:03:52 +02:00
.mailmap MAINTAINERS, mailmap: Change Ulf Hansson's email 2026-04-07 14:17:48 +02:00
.pylintrc docs: Move the python libraries to tools/lib/python 2025-11-18 09:22:40 -07:00
.rustfmt.toml
COPYING
CREDITS MAINTAINERS: remove Thomas Falcon from IBM ibmvnic 2026-03-05 07:35:45 -08:00
Kbuild sched: Make migrate_{en,dis}able() inline 2025-09-25 09:57:16 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS Power management updates for 7.1-rc1 2026-04-13 19:47:52 -07:00
Makefile Rust changes for v7.1 2026-04-13 09:54:20 -07:00
README docs: add AI Coding Assistants documentation 2026-01-06 14:55:06 -07:00

Linux kernel
============

The Linux kernel is the core of any Linux operating system. It manages hardware,
system resources, and provides the fundamental services for all other software.

Quick Start
-----------

* Report a bug: See Documentation/admin-guide/reporting-issues.rst
* Get the latest kernel: https://kernel.org
* Build the kernel: See Documentation/admin-guide/quickly-build-trimmed-linux.rst
* Join the community: https://lore.kernel.org/

Essential Documentation
-----------------------

All users should be familiar with:

* Building requirements: Documentation/process/changes.rst
* Code of Conduct: Documentation/process/code-of-conduct.rst
* License: See COPYING

Documentation can be built with make htmldocs or viewed online at:
https://www.kernel.org/doc/html/latest/


Who Are You?
============

Find your role below:

* New Kernel Developer - Getting started with kernel development
* Academic Researcher - Studying kernel internals and architecture
* Security Expert - Hardening and vulnerability analysis
* Backport/Maintenance Engineer - Maintaining stable kernels
* System Administrator - Configuring and troubleshooting
* Maintainer - Leading subsystems and reviewing patches
* Hardware Vendor - Writing drivers for new hardware
* Distribution Maintainer - Packaging kernels for distros
* AI Coding Assistant - LLMs and AI-powered development tools


For Specific Users
==================

New Kernel Developer
--------------------

Welcome! Start your kernel development journey here:

* Getting Started: Documentation/process/development-process.rst
* Your First Patch: Documentation/process/submitting-patches.rst
* Coding Style: Documentation/process/coding-style.rst
* Build System: Documentation/kbuild/index.rst
* Development Tools: Documentation/dev-tools/index.rst
* Kernel Hacking Guide: Documentation/kernel-hacking/hacking.rst
* Core APIs: Documentation/core-api/index.rst

Academic Researcher
-------------------

Explore the kernel's architecture and internals:

* Researcher Guidelines: Documentation/process/researcher-guidelines.rst
* Memory Management: Documentation/mm/index.rst
* Scheduler: Documentation/scheduler/index.rst
* Networking Stack: Documentation/networking/index.rst
* Filesystems: Documentation/filesystems/index.rst
* RCU (Read-Copy Update): Documentation/RCU/index.rst
* Locking Primitives: Documentation/locking/index.rst
* Power Management: Documentation/power/index.rst

Security Expert
---------------

Security documentation and hardening guides:

* Security Documentation: Documentation/security/index.rst
* LSM Development: Documentation/security/lsm-development.rst
* Self Protection: Documentation/security/self-protection.rst
* Reporting Vulnerabilities: Documentation/process/security-bugs.rst
* CVE Procedures: Documentation/process/cve.rst
* Embargoed Hardware Issues: Documentation/process/embargoed-hardware-issues.rst
* Security Features: Documentation/userspace-api/seccomp_filter.rst

Backport/Maintenance Engineer
-----------------------------

Maintain and stabilize kernel versions:

* Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst
* Backporting Guide: Documentation/process/backporting.rst
* Applying Patches: Documentation/process/applying-patches.rst
* Subsystem Profile: Documentation/maintainer/maintainer-entry-profile.rst
* Git for Maintainers: Documentation/maintainer/configure-git.rst

System Administrator
--------------------

Configure, tune, and troubleshoot Linux systems:

* Admin Guide: Documentation/admin-guide/index.rst
* Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst
* Sysctl Tuning: Documentation/admin-guide/sysctl/index.rst
* Tracing/Debugging: Documentation/trace/index.rst
* Performance Security: Documentation/admin-guide/perf-security.rst
* Hardware Monitoring: Documentation/hwmon/index.rst

Maintainer
----------

Lead kernel subsystems and manage contributions:

* Maintainer Handbook: Documentation/maintainer/index.rst
* Pull Requests: Documentation/maintainer/pull-requests.rst
* Managing Patches: Documentation/maintainer/modifying-patches.rst
* Rebasing and Merging: Documentation/maintainer/rebasing-and-merging.rst
* Development Process: Documentation/process/maintainer-handbooks.rst
* Maintainer Entry Profile: Documentation/maintainer/maintainer-entry-profile.rst
* Git Configuration: Documentation/maintainer/configure-git.rst

Hardware Vendor
---------------

Write drivers and support new hardware:

* Driver API Guide: Documentation/driver-api/index.rst
* Driver Model: Documentation/driver-api/driver-model/driver.rst
* Device Drivers: Documentation/driver-api/infrastructure.rst
* Bus Types: Documentation/driver-api/driver-model/bus.rst
* Device Tree Bindings: Documentation/devicetree/bindings/
* Power Management: Documentation/driver-api/pm/index.rst
* DMA API: Documentation/core-api/dma-api.rst

Distribution Maintainer
-----------------------

Package and distribute the kernel:

* Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst
* ABI Documentation: Documentation/ABI/README
* Kernel Configuration: Documentation/kbuild/kconfig.rst
* Module Signing: Documentation/admin-guide/module-signing.rst
* Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst
* Tainted Kernels: Documentation/admin-guide/tainted-kernels.rst

AI Coding Assistant
-------------------

CRITICAL: If you are an LLM or AI-powered coding assistant, you MUST read and
follow the AI coding assistants documentation before contributing to the Linux
kernel:

* Documentation/process/coding-assistants.rst

This documentation contains essential requirements about licensing, attribution,
and the Developer Certificate of Origin that all AI tools must comply with.


Communication and Support
=========================

* Mailing Lists: https://lore.kernel.org/
* IRC: #kernelnewbies on irc.oftc.net
* Bugzilla: https://bugzilla.kernel.org/
* MAINTAINERS file: Lists subsystem maintainers and mailing lists
* Email Clients: Documentation/process/email-clients.rst