Linus Torvalds 43dfc13ca9 Merge tag 'pci-v6.19-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci
Pull PCI updates from Bjorn Helgaas:
 "Enumeration:

   - Enable host bridge emulation for PCI_DOMAINS_GENERIC platforms (Dan
     Williams)

   - Switch vmd from custom domain number allocator to the common
     allocator to prevent a potential race with new non-VMD buses (Dan
     Williams)

   - Enable Precision Time Measurement (PTM) only if device advertises
     support for a relevant role, to prevent invalid PTM Requests that
     cause ACS violations that are reported as AER Uncorrectable
     Non-Fatal errors (Mika Westerberg)

  Resource management:

   - Prevent resource tree corruption when BAR resize fails (Ilpo
     Järvinen)

   - Restore BARs to the original size if a BAR resize fails (Ilpo
     Järvinen)

   - Remove BAR release from BAR resize attempts by the xe, i915, and
     amdgpu drivers so the PCI core can restore BARs if the resize fails
     (Ilpo Järvinen)

   - Move Resizable BAR code to rebar.c (Ilpo Järvinen)

   - Add pci_rebar_size_supported() and use it in i915 and xe (Ilpo
     Järvinen)

   - Add pci_rebar_get_max_size() and use it in xe and amdgpu (Ilpo
     Järvinen)

  Power management and error handling:

   - For drivers using PCI legacy suspend, save config state at suspend
     so that state (not any earlier state from enumeration, probe, or
     error recovery) will be restored when resuming (Lukas Wunner)

   - For devices with no driver or a driver that lacks power management,
     save config state at hibernate so that state (not any earlier state
     from enumeration, probe, or error recovery) will be restored when
     resuming (Lukas Wunner)

   - Save device config space on device addition, before driver binding,
     so error recovery works more reliably (Lukas Wunner)

   - Drop pci_save_state() from several drivers that no longer need it
     since the PCI core always does it and pci_restore_state() no longer
     invalidates the saved state (Lukas Wunner)

   - Document use of pci_save_state() by drivers to capture the state
     they want restored during error recovery (Lukas Wunner)

  Power control:

   - Add a struct pci_ops.assert_perst() function pointer to
     assert/deassert PCIe PERST# and implement it for the qcom driver
     (Krishna Chaitanya Chundru)

   - Add DT binding and pwrctrl driver for the Toshiba TC9563 PCIe
     switch, which must be held in reset after poweron so the pwrctrl
     driver can configure the switch via I2C before bringing up the
     links (Krishna Chaitanya Chundru)

  Endpoint framework:

   - Convert the endpoint doorbell test to use a threaded IRQ to fix a
     'sleeping while atomic' issue (Bhanu Seshu Kumar Valluri)

   - Add endpoint VNTB MSI doorbell support to reduce latency between
     host and endpoint (Frank Li)

  New native PCIe controller drivers:

   - Add CIX Sky1 host controller DT binding and driver (Hans Zhang)

   - Add NXP S32G host controller DT binding and driver (Vincent
     Guittot)

   - Add Renesas RZ/G3S host controller DT binding and driver (Claudiu
     Beznea)

   - Add SpacemiT K1 host controller DT binding and driver (Alex Elder)

  Amlogic Meson PCIe controller driver:

   - Update DT binding to name DBI region 'dbi', not 'elbi', and update
     driver to support both (Manivannan Sadhasivam)

  Apple PCIe controller driver:

   - Move struct pci_host_bridge allocation from pci_host_common_init()
     to callers, which significantly simplifies pcie-apple (Marc
     Zyngier)

  Broadcom STB PCIe controller driver:

   - Disable advertising ASPM L0s support correctly (Jim Quinlan)

   - Add a panic/die handler to print diagnostic info in case PCIe
     caused an unrecoverable abort (Jim Quinlan)

  Cadence PCIe controller driver:

   - Add module support for Cadence platform host and endpoint
     controller driver (Manikandan K Pillai)

   - Split headers into 'legacy' (LGA) and 'high perf' (HPA) to prepare
     for new CIX Sky1 driver (Manikandan K Pillai)

  MediaTek PCIe controller driver:

   - Convert DT binding to YAML schema (Christian Marangi)

   - Add Airoha AN7583 DT compatible and driver support (Christian
     Marangi)

  Qualcomm PCIe controller driver:

   - Add Qualcomm Kaanapali to SM8550 DT binding (Qiang Yu)

   - Add required 'power-domains' and 'resets' to qcom sa8775p, sc7280,
     sc8280xp, sm8150, sm8250, sm8350, sm8450, sm8550, x1e80100 DT
     schemas (Krzysztof Kozlowski)

   - Look up OPP using both frequency and data rate (not just frequency)
     so RPMh votes can account for both (Krishna Chaitanya Chundru)

  Rockchip DesignWare PCIe controller driver:

   - Add Rockchip RK3528 compatible strings in DT binding (Yao Zi)

  STMicroelectronics STM32MP25 PCIe controller driver:

   - Fix a race between link training and endpoint register
     initialization (Christian Bruel)

   - Align endpoint allocations to match the ATU requirements (Christian
     Bruel)

  Synopsys DesignWare PCIe controller driver:

   - Clear L1 PM Substate Capability 'Supported' bits unless glue driver
     says it's supported, which prevents users from enabling non-working
     L1SS. Currently only qcom and tegra194 support L1SS (Bjorn Helgaas)

   - Remove now-superfluous L1SS disable code from tegra194 (Bjorn
     Helgaas)

   - Configure L1SS support in dw-rockchip when DT says
     'supports-clkreq' (Shawn Lin)

  TI Keystone PCIe controller driver:

   - Fail the probe instead of silently succeeding if ks_pcie_of_data
     didn't specify Root Complex or Endpoint mode (Siddharth Vadapalli)

   - Make keystone buildable as a loadable module, except on ARM32 where
     hook_fault_code() is __init (Siddharth Vadapalli)"

* tag 'pci-v6.19-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci: (100 commits)
  MAINTAINERS: Add Manivannan Sadhasivam as PCI/pwrctrl maintainer
  MAINTAINERS: Add CIX Sky1 PCIe controller driver maintainer
  PCI: sky1: Add PCIe host support for CIX Sky1
  dt-bindings: PCI: Add CIX Sky1 PCIe Root Complex bindings
  PCI: cadence: Add support for High Perf Architecture (HPA) controller
  MAINTAINERS: Add NXP S32G PCIe controller driver maintainer
  PCI: s32g: Add NXP S32G PCIe controller driver (RC)
  PCI: dwc: Add register and bitfield definitions
  dt-bindings: PCI: s32g: Add NXP S32G PCIe controller
  PCI: Add Renesas RZ/G3S host controller driver
  PCI: host-generic: Move bridge allocation outside of pci_host_common_init()
  dt-bindings: PCI: Add Renesas RZ/G3S PCIe controller binding
  PCI: Validate pci_rebar_size_supported() input
  Documentation: PCI: Amend error recovery doc with pci_save_state() rules
  treewide: Drop pci_save_state() after pci_restore_state()
  PCI/ERR: Ensure error recoverability at all times
  PCI/PM: Stop needlessly clearing state_saved on enumeration and thaw
  PCI/PM: Reinstate clearing state_saved in legacy and !PM codepaths
  PCI: dw-rockchip: Configure L1SS support
  PCI: tegra194: Remove unnecessary L1SS disable code
  ...
2025-12-04 17:29:41 -08:00
2022-09-28 09:02:20 +02:00
2025-02-19 14:53:27 -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


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



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
Description
Linux kernel source tree
Readme 8.3 GiB
Languages
C 97.1%
Assembly 1%
Shell 0.6%
Rust 0.4%
Python 0.4%
Other 0.3%