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
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The list_lru will now handle numa for us, so no need to keep
separate pool types for it. Just consolidate into the global ones.
This adds a debugfs change to avoid dumping non-existant orders due
to this change.
Cc: Christian Koenig <christian.koenig@amd.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This is an initial port of the TTM pools for
write combined and uncached pages to use the list_lru.
This makes the pool's more NUMA aware and avoids
needing separate NUMA pools (later commit enables this).
Cc: Christian Koenig <christian.koenig@amd.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This uses the newly introduced per-node gpu tracking stats,
to track GPU memory allocated via TTM and reclaimable memory in
the TTM page pools.
These stats will be useful later for system information and
later when mem cgroups are integrated.
Cc: Christian Koenig <christian.koenig@amd.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: linux-mm@kvack.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
While discussing memcg intergration with gpu memory allocations,
it was pointed out that there was no numa/system counters for
GPU memory allocations.
With more integrated memory GPU server systems turning up, and
more requirements for memory tracking it seems we should start
closing the gap.
Add two counters to track GPU per-node system memory allocations.
The first is currently allocated to GPU objects, and the second
is for memory that is stored in GPU page pools that can be reclaimed,
by the shrinker.
Cc: Christian Koenig <christian.koenig@amd.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: linux-mm@kvack.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Zi Yan <ziy@nvidia.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Thomas Zimmermann needs 2f42c1a61616 ("drm/ast: dp501: Fix
initialization of SCU2C") for drm-misc-next.
Conflicts:
- drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c
Just between e927b36ae18b ("drm/amd/display: Fix NULL pointer
dereference in dcn401_init_hw()") and it's cherry-pick that confused
git.
- drivers/gpu/drm/amd/pm/swsmu/smu11/smu_v11_0.c
Deleted in 6b0a6116286e ("drm/amd/pm: Unify version check in SMUv11")
but some cherry-picks confused git. Same for v12/v14.
Signed-off-by: Simona Vetter <simona.vetter@ffwll.ch>
Changes for v7.1
CI:
- Uprev mesa
- Restore CI jobs for Qualcomm APQ8016 and APQ8096 devices
Core:
- Switched to of_get_available_child_by_name()
DPU:
- Fixes for DSC panels
- Fixed brownout because of the frequency / OPP mismatch
- Quad pipe preparation (not enabled yet)
- Switched to virtual planes by default
- Dropped VBIF_NRT support
- Added support for Eliza platform
- Reworked alpha handling
- Switched to correct CWB definitions on Eliza
- Dropped dummy INTF_0 on MSM8953
- Corrected INTFs related to DP-MST
DP:
- Removed debug prints looking into PHY internals
DSI:
- Fixes for DSC panels
- RGB101010 support
- Support for SC8280XP
- Moved PHY bindings from display/ to phy/
GPU:
- Preemption support for x2-85 and a840
- IFPC support for a840
- SKU detection support for x2-85 and a840
- Expose AQE support (VK ray-pipeline)
- Avoid locking in VM_BIND fence signaling path
- Fix to avoid reclaim in GPU snapshot path
- Disallow foreign mapping of _NO_SHARE BOs
- Couple a6xx gpu snapshot fixes
- Various other fixes
HDMI:
- Fixed infoframes programming
MDP5:
- Dropped support for MSM8974v1
- Dropped now unused code for MSM8974 v1 and SDM660 / MSM8998
Also misc small fixes
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Rob Clark <rob.clark@oss.qualcomm.com>
Link: https://patch.msgid.link/CACSVV012vn73BaUfk=Hw4WkQHZNPHiqfifWEunAqMc2EGOWUEQ@mail.gmail.com
amd-drm-next-7.1-2026-04-01:
amdgpu:
- UserQ fixes
- PASID handling fix
- S4 fix for smu11 chips
- devcoredump fixes
- RAS fixes
- Misc small fixes
- DCN 4.2 updates
- DVI fixes
- DML fixes
- DC pipe validation fixes
- eDP DSC seamless boot
- DC FP rework
- swsmu cleanups
- GC 11.5.4 updates
- Add DC idle state manager
- Add support for using multiple engines for buffer fills and clears
- Misc SMU7 fixes
amdkfd:
- Non-4K page fixes
- Logging cleanups
- sysfs fixes
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Alex Deucher <alexander.deucher@amd.com>
Link: https://patch.msgid.link/20260401184456.3576660-1-alexander.deucher@amd.com
Simplify zap_shader_load_mdt() by using of_get_available_child_by_name().
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Patchwork: https://patchwork.freedesktop.org/patch/635020/
Link: https://lore.kernel.org/r/20250201155830.39366-1-biju.das.jz@bp.renesas.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Pull RISC-V fixes from Paul Walmsley:
- Fix a CONFIG_SPARSEMEM crash on RV32 by avoiding early phys_to_page()
- Prevent runtime const infrastructure from being used by modules,
similar to what was done for x86
- Avoid problems when shutting down ACPI systems with IOMMUs by adding
a device dependency between IOMMU and devices that use it
- Fix a bug where the CPU pointer masking state isn't properly reset
when tagged addresses aren't enabled for a task
- Fix some incorrect register assignments, and add some missing ones,
in kgdb support code
- Fix compilation of non-kernel code that uses the ptrace uapi header
by replacing BIT() with _BITUL()
- Fix compilation of the validate_v_ptrace kselftest by working around
kselftest macro expansion issues
* tag 'riscv-for-linus-7.0-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
ACPI: RIMT: Add dependency between iommu and devices
selftests: riscv: Add braces around EXPECT_EQ()
riscv: use _BITUL macro rather than BIT() in ptrace uapi and kselftests
riscv: Reset pmm when PR_TAGGED_ADDR_ENABLE is not set
riscv: make runtime const not usable by modules
riscv: patch: Avoid early phys_to_page()
riscv: kgdb: fix several debug register assignment bugs
DRM Rust changes for v7.1-rc1
- DMA:
- Rework the DMA coherent API: introduce Coherent<T> as a generalized
container for arbitrary types, replacing the slice-only
CoherentAllocation<T>. Add CoherentBox for memory initialization
before exposing a buffer to hardware (converting to Coherent when
ready), and CoherentHandle for allocations without kernel mapping.
- Add Coherent::init() / init_with_attrs() for one-shot initialization
via pin-init, and from-slice constructors for both Coherent and
CoherentBox
- Add uaccess write_dma() for copying from DMA buffers to userspace
and BinaryWriter support for Coherent<T>
- DRM:
- Add GPU buddy allocator abstraction
- Add DRM shmem GEM helper abstraction
- Allow drm::Device to dispatch work and delayed work items to driver
private data
- Add impl_aref_for_gem_obj!() macro to reduce GEM refcount
boilerplate, and introduce DriverObject::Args for constructor
context
- Add dma_resv_lock helper and raw_dma_resv() accessor on GEM objects
- Clean up imports across the DRM module
- I/O:
- Merged via a signed tag from the driver-core tree: register!() macro
and I/O infrastructure improvements (IoCapable refactor, RelaxedMmio
wrapper, IoLoc trait, generic accessors, write_reg /
LocatedRegister)
- Nova (Core):
- Fix and harden the GSP command queue: correct write pointer
advancing, empty slot handling, and ring buffer indexing; add mutex
locking and make Cmdq a pinned type; distinguish wait vs no-wait
commands
- Add support for large RPCs via continuation records, splitting
oversized commands across multiple queue slots
- Simplify GSP sequencer and message handling code: remove unused
trait and Display impls, derive Debug and Zeroable where applicable,
warn on unconsumed message data
- Refactor Falcon firmware handling: create DMA objects lazily, add
PIO upload support, and use the Generic Bootloader to boot FWSEC on
Turing
- Convert all register definitions (PMC, PBUS, PFB, GC6, FUSE, PDISP,
Falcon) to the kernel register!() macro; add bounded_enum macro to
define enums usable as register fields
- Migrate all DMA usage to the new Coherent, CoherentBox, and
CoherentHandle APIs
- Harden firmware parsing with checked arithmetic throughout FWSEC,
Booter, RISC-V parsing paths
- Add debugfs support for reading GSP-RM log buffers; replace
module_pci_driver!() with explicit module init to support
module-level debugfs setup
- Fix auxiliary device registration for multi-GPU systems
- Various cleanups: import style, firmware parsing refactoring,
framebuffer size logging
- Rust:
- Add interop::list module providing a C linked list interface
- Extend num::Bounded with shift operations, into_bool(), and const
get() to support register bitfield manipulation
- Enable the generic_arg_infer Rust feature and add EMSGSIZE error
code
- Tyr:
- Adopt vertical import style per kernel Rust guidelines
- Clarify driver/device type names and use DRM device type alias
consistently across the driver
- Fix GPU model/version decoding in GpuInfo
- Workqueue:
- Add ARef<T> support for work and delayed work
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: "Danilo Krummrich" <dakr@kernel.org>
Link: https://patch.msgid.link/DHGH4BLT03BU.ZJH5U52WE8BY@kernel.org
UVD 4.2 doesn't work at all when DPM is disabled because
the SMU is responsible for ungating it. So, Linux fails
to boot with CIK GPUs when using the amdgpu.dpm=0 parameter.
Fix this by returning -ENOENT from uvd_v4_2_early_init()
when amdgpu_dpm isn't enabled.
Note: amdgpu.dpm=0 is often suggested as a workaround
for issues and is useful for debugging.
Fixes: a2e73f56fa62 ("drm/amdgpu: Add support for CIK parts")
Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Historically DSI PHY bindings landed to the display/msm subdir, however
they describe PHYs and as such they should be in the phy/ subdir.
Follow the example of other Qualcomm display-related PHYs (HDMI, eDP)
and move bindings for the Qualcomm DSI PHYs to the correct subdir.
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>
Patchwork: https://patchwork.freedesktop.org/patch/709008/
Link: https://lore.kernel.org/r/20260305-msm-dsi-phy-v1-1-0a99ac665995@oss.qualcomm.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Pull x86 fixes from Ingo Molnar:
- Fix kexec crash on KCOV-instrumented kernels (Aleksandr Nogikh)
- Fix Geode platform driver on-stack property data use-after-return
bug (Dmitry Torokhov)
* tag 'x86-urgent-2026-04-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/platform/geode: Fix on-stack property data use-after-return bug
x86/kexec: Disable KCOV instrumentation after load_segments()
EPROBE_DEFER ensures IOMMU devices are probed before the devices that
depend on them. During shutdown, however, the IOMMU may be removed
first, leading to issues. To avoid this, a device link is added
which enforces the correct removal order.
Fixes: 8f7729552582 ("ACPI: RISC-V: Add support for RIMT")
Signed-off-by: Sunil V L <sunilvl@oss.qualcomm.com>
Link: https://patch.msgid.link/20260303061605.722949-1-sunilvl@oss.qualcomm.com
Signed-off-by: Paul Walmsley <pjw@kernel.org>
drm/i915 feature pull #2 for v7.1:
Refactoring and cleanups:
- Refactor LT PHY PLL handling to use the DPLL framework (Mika)
- Implement display register polling and waits in display code (Ville)
- Move PCH clock gating in display PCH file (Luca)
- Add shared stepping info header for i915 and display (Jani)
- Clean up GVT I2C command decoding (Jonathan)
- NV12 plane unlinking cleanups (Ville)
- Clean up NV12 DDB/watermark handling for pre-ICL platforms (Ville)
Fixes:
- An assortment of DSI fixes (Ville)
- Handle PORT_NONE in assert_port_valid() (Jonathan)
- Fix link failure without FBDEV emulation (Arnd Bergmann)
- Quirk disable panel replay on certain Dell XPS models (Jouni)
- Check if VESA DPCD AUX backlight is possible (Suraj)
Other:
- Mailmap update for Christoph (Christoph)
Signed-off-by: Dave Airlie <airlied@redhat.com>
# Conflicts:
# drivers/gpu/drm/i915/display/intel_plane.c
From: Jani Nikula <jani.nikula@intel.com>
Link: https://patch.msgid.link/ac9dfdb745d5a67c519ea150a6f36f8f74b8760e@intel.com