Sphinx reports htmldocs warnings:
Documentation/arch/x86/boot.rst:437: ERROR: Malformed table.
Text in column margin in table line 2.
The table header defined the first column width as 2 characters ("=="),
which is too narrow for entries like "0x10" and "0x13". This caused the
text to spill into the margin, triggering a docutils parsing failure.
Fix it by extending the first column of assigned boot loader ID to 4
characters ("====") to fit the widest entries.
Fixes: 1c3377bee2 ("x86/boot/Documentation: Prefix hexadecimal literals with 0x")
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Swaraj Gaikwad <swarajgaikwad1925@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Link: https://patch.msgid.link/20251210092814.9986-1-swarajgaikwad1925@gmail.com
Pull x86 fixes from Ingo Molnar:
"Miscellaneous documentation fixes"
* tag 'x86-urgent-2025-12-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/boot/Documentation: Prefix hexadecimal literals with 0x
x86/boot/Documentation: Spell 'ID' consistently
x86/platform: Fix and extend kernel-doc comments in <asm/x86_init.h>
The x86 bootloader ID specification text uses hexadecimal
values without a 0x prefix:
D kexec-tools
E Extended (see ext_loader_type)
F Special (0xFF = undefined)
10 Reserved
11 Minimal Linux Bootloader
<http://sebastian-plotz.blogspot.de>
12 OVMF UEFI virtualization stack
13 barebox
Which beyond the ambiguity of '13' in isolation, also
made me fail a grep -wi '0xd' when I was looking for
the kexec bootloader ID definition and caused quite
a bit of head-scratching before I found out why it
didn't show up.
Furthermore, the actual explanatory text uses the 0x
prefix:
For boot loader IDs above T = 0xD, write T = 0xE to this field and
write the extended ID minus 0x10 to the ext_loader_type field.
Similarly, the ext_loader_ver field can be used to provide more than
four bits for the bootloader version.
So make it all both unambiguous, easy to grep and consistent
across the entire documentation by prefixing the IDs with 0x.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: linux-kernel@vger.kernel.org
The bootloader ID specification text uses 2 capitalization
variants for the same thing: 'id', 'ids', 'ID' and 'IDs'.
Use 'ID/IDs' consistently.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: linux-kernel@vger.kernel.org
Since the Handover Protocol was deprecated, the recommended approach is
to provide an initrd using a UEFI boot service with the
LINUX_EFI_INITRD_MEDIA_GUID device path. Documentation for the new
approach has been no more than an admonition with a link to an existing
implementation.
Provide a short explanation of this functionality, to ease future
implementations without having to reverse engineer existing ones.
[Bagas: Don't use :ref: link to EFI stub documentation and refer to
OVMF/edk2 implementation]
Signed-off-by: Hugo Osvaldo Barrera <hugo@whynothugo.nl>
Link: https://lore.kernel.org/r/20250428131206.8656-2-hugo@whynothugo.nl
Co-developed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20251013085718.27085-1-bagasdotme@gmail.com>
Pull x86 TDX updates from Dave Hansen:
"The biggest change here is making TDX and kexec play nicely together.
Before this, the memory encryption hardware (which doesn't respect
cache coherency) could write back old cachelines on top of data in the
new kernel, so kexec and TDX were made mutually exclusive. This
removes the limitation.
There is also some work to tighten up a hardware bug workaround and
some MAINTAINERS updates.
- Make TDX and kexec work together
- Skip TDX bug workaround when the bug is not present
- Update maintainers entries"
* tag 'x86_tdx_for_6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/virt/tdx: Use precalculated TDVPR page physical address
KVM/TDX: Explicitly do WBINVD when no more TDX SEAMCALLs
x86/virt/tdx: Update the kexec section in the TDX documentation
x86/virt/tdx: Remove the !KEXEC_CORE dependency
x86/kexec: Disable kexec/kdump on platforms with TDX partial write erratum
x86/virt/tdx: Mark memory cache state incoherent when making SEAMCALL
x86/sme: Use percpu boolean to control WBINVD during kexec
x86/kexec: Consolidate relocate_kernel() function parameters
x86/tdx: Skip clearing reclaimed pages unless X86_BUG_TDX_PW_MCE is present
x86/tdx: Tidy reset_pamt functions
x86/tdx: Eliminate duplicate code in tdx_clear_page()
MAINTAINERS: Add KVM mail list to the TDX entry
MAINTAINERS: Add Rick Edgecombe as a TDX reviewer
MAINTAINERS: Update the file list in the TDX entry.
Pull documentation updates from Jonathan Corbet:
"It has been a relatively busy cycle in docsland, with changes all
over:
- Bring the kernel memory-model docs into the Sphinx build in the
"literal include" mode.
- Lots of build-infrastructure work, further cleaning up long-term
kernel-doc technical debt. The sphinx-pre-install tool has been
converted to Python and updated for current systems.
- A new tool to detect when documents have been moved and generate
HTML redirects; this can be used on kernel.org (or any other site
hosting the rendered docs) to avoid breaking links.
- Automated processing of the YAML files describing the netlink
protocol.
- A significant update of the maintainer's PGP guide.
... and a seemingly endless series of typo fixes, build-problem fixes,
etc"
* tag 'docs-6.18' of git://git.lwn.net/linux: (193 commits)
Documentation/features: Update feature lists for 6.17-rc7
docs: remove cdomain.py
Documentation/process: submitting-patches: fix typo in "were do"
docs: dev-tools/lkmm: Fix typo of missing file extension
Documentation: trace: histogram: Convert ftrace docs cross-reference
Documentation: trace: histogram-design: Wrap introductory note in note:: directive
Documentation: trace: historgram-design: Separate sched_waking histogram section heading and the following diagram
Documentation: trace: histogram-design: Trim trailing vertices in diagram explanation text
Documentation: trace: histogram: Fix histogram trigger subsection number order
docs: driver-api: fix spelling of "buses".
Documentation: fbcon: Use admonition directives
Documentation: fbcon: Reindent 8th step of attach/detach/unload
Documentation: fbcon: Add boot options and attach/detach/unload section headings
docs: filesystems: sysfs: add remaining top level sysfs directory descriptions
docs: filesystems: sysfs: clarify symlink destinations in dev and bus/devices descriptions
docs: filesystems: sysfs: remove top level sysfs net directory
docs: maintainer: Fix ambiguous subheading formatting
docs: kdoc: a few more dump_typedef() tweaks
docs: kdoc: remove redundant comment stripping in dump_typedef()
docs: kdoc: remove some dead code in dump_typedef()
...
Pull x86 platform updates from Ingo Molnar:
"This adds support for the AMD hardware feedback interface (HFI), by
Perry Yuan"
* tag 'x86-platform-2025-07-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/itmt: Add debugfs file to show core priorities
platform/x86/amd: hfi: Add debugfs support
platform/x86/amd: hfi: Set ITMT priority from ranking data
cpufreq/amd-pstate: Disable preferred cores on designs with workload classification
x86/process: Clear hardware feedback history for AMD processors
platform/x86: hfi: Add power management callback
platform/x86: hfi: Add online and offline callback support
platform/x86: hfi: Init per-cpu scores for each class
platform/x86: hfi: Parse CPU core ranking data from shared memory
platform/x86: hfi: Introduce AMD Hardware Feedback Interface Driver
x86/msr-index: Add AMD workload classification MSRs
MAINTAINERS: Add maintainer entry for AMD Hardware Feedback Driver
Documentation/x86: Add AMD Hardware Feedback Interface documentation
Pull hardening updates from Kees Cook:
- Introduce and start using TRAILING_OVERLAP() helper for fixing
embedded flex array instances (Gustavo A. R. Silva)
- mux: Convert mux_control_ops to a flex array member in mux_chip
(Thorsten Blum)
- string: Group str_has_prefix() and strstarts() (Andy Shevchenko)
- Remove KCOV instrumentation from __init and __head (Ritesh Harjani,
Kees Cook)
- Refactor and rename stackleak feature to support Clang
- Add KUnit test for seq_buf API
- Fix KUnit fortify test under LTO
* tag 'hardening-v6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (22 commits)
sched/task_stack: Add missing const qualifier to end_of_stack()
kstack_erase: Support Clang stack depth tracking
kstack_erase: Add -mgeneral-regs-only to silence Clang warnings
init.h: Disable sanitizer coverage for __init and __head
kstack_erase: Disable kstack_erase for all of arm compressed boot code
x86: Handle KCOV __init vs inline mismatches
arm64: Handle KCOV __init vs inline mismatches
s390: Handle KCOV __init vs inline mismatches
arm: Handle KCOV __init vs inline mismatches
mips: Handle KCOV __init vs inline mismatch
powerpc/mm/book3s64: Move kfence and debug_pagealloc related calls to __init section
configs/hardening: Enable CONFIG_INIT_ON_FREE_DEFAULT_ON
configs/hardening: Enable CONFIG_KSTACK_ERASE
stackleak: Split KSTACK_ERASE_CFLAGS from GCC_PLUGINS_CFLAGS
stackleak: Rename stackleak_track_stack to __sanitizer_cov_stack_depth
stackleak: Rename STACKLEAK to KSTACK_ERASE
seq_buf: Introduce KUnit tests
string: Group str_has_prefix() and strstarts()
kunit/fortify: Add back "volatile" for sizeof() constants
acpi: nfit: intel: avoid multiple -Wflex-array-member-not-at-end warnings
...
In preparation for adding Clang sanitizer coverage stack depth tracking
that can support stack depth callbacks:
- Add the new top-level CONFIG_KSTACK_ERASE option which will be
implemented either with the stackleak GCC plugin, or with the Clang
stack depth callback support.
- Rename CONFIG_GCC_PLUGIN_STACKLEAK as needed to CONFIG_KSTACK_ERASE,
but keep it for anything specific to the GCC plugin itself.
- Rename all exposed "STACKLEAK" names and files to "KSTACK_ERASE" (named
for what it does rather than what it protects against), but leave as
many of the internals alone as possible to avoid even more churn.
While here, also split "prev_lowest_stack" into CONFIG_KSTACK_ERASE_METRICS,
since that's the only place it is referenced from.
Suggested-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20250717232519.2984886-1-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
Introduce a new documentation file, `amd_hfi.rst`, which delves into the
implementation details of the AMD Hardware Feedback Interface and its
associated driver, `amd_hfi`. This documentation describes how the driver
provides hint to the OS scheduling which depends on the capability of core
performance and efficiency ranking data.
This documentation describes:
* The design of the driver
* How the driver provides hints to the OS scheduling
* How the driver interfaces with the kernel for efficiency ranking data.
Signed-off-by: Perry Yuan <Perry.Yuan@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Acked-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/20250609200518.3616080-2-superm1@kernel.org
Pull x86 platform drivers updates from Ilpo Järvinen:
"The changes are mostly business as usual. Besides pdx86 changes, there
are a few power supply changes needed for related pdx86 features, move
of oxpec driver from hwmon (oxp-sensors) to pdx86, and one FW version
warning to hid-asus.
Highlights:
- alienware-wmi-wmax:
- Add HWMON support
- Add ABI and admin-guide documentation
- Expose GPIO debug methods through debug FS
- Support manual fan control and "custom" thermal profile
- amd/hsmp:
- Add sysfs files to show HSMP telemetry
- Report power readings and limits via hwmon
- amd/isp4: Add AMD ISP platform config for OV05C10
- asus-wmi:
- Refactor Ally suspend/resume to work better with older FW
- hid-asus: check ROG Ally MCU version and warn about old FW versions
- dasharo-acpi:
- Add driver for Dasharo devices supporting fans and temperatures
monitoring
- dell-ddv:
- Expose the battery health and manufacture date to userspace
using power supply extensions
- Implement the battery matching algorithm
- dell-pc:
- Improve error propagation
- Use faux device
- int3472:
- Add delays to avoid GPIO regulator spikes
- Add handshake pin support
- Make regulator supply name configurable and allow registering
more than 1 GPIO regulator
- Map mt9m114 powerdown pin to powerenable
- intel/pmc: Add separate SSRAM Telemetry driver
- intel-uncore-freq: Add attributes to show agent types and die ID
- ISST:
- Support SST-TF revision 2 (allows more cores per bucket)
- Support SST-PP revision 2 (fabric 1 frequencies)
- Remove unnecessary SST MSRs restore (the package retains MSRs
despite CPU offlining)
- mellanox: Add support for SN2201, SN4280, SN5610, and SN5640
- mellanox: mlxbf-pmc: Support additional PMC blocks
- oxpec:
- Add OneXFly variants
- Add support for charge limit, charge thresholds, and turbo LED
- Distinguish current X1 variants to avoid unwanted matching to
new variants
- Follow hwmon conventions
- Move from hwmon/oxp-sensors to platform/x86 to match the
enlarged scope
- power supply:
- Add inhibit-charge-awake (needed by oxpec)
- Add additional battery health status values ("blown fuse" and
"cell imbalance") (needed by dell-ddv)
- powerwell-ec: Add driver for Portwell EC supporting GPIO and watchdog
- thinkpad-acpi: Support camera shutter switch hotkey
- tuxedo: Add virtual LampArray for TUXEDO NB04 devices
- tools/power/x86/intel-speed-select:
- Support displaying SST-PP revision 2 fields
- Skip uncore frequency update on newer generations of CPUs
- Miscellaneous cleanups / refactoring / improvements"
* tag 'platform-drivers-x86-v6.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86: (112 commits)
thermal/drivers/acerhdf: Constify struct thermal_zone_device_ops
platform/x86/amd/hsmp: fix building with CONFIG_HWMON=m
platform/x86: asus-wmi: fix build without CONFIG_SUSPEND
docs: ABI: Fix "aassociated" to "associated"
platform/x86: Add AMD ISP platform config for OV05C10
Documentation: admin-guide: pm: Add documentation for die_id
platform/x86/intel-uncore-freq: Add attributes to show die_id
platform/x86/intel: power-domains: Add interface to get Linux die ID
Documentation: admin-guide: pm: Add documentation for agent_types
platform/x86/intel-uncore-freq: Add attributes to show agent types
platform/x86/tuxedo: Prevent invalid Kconfig state
platform/x86: dell-ddv: Expose the battery health to userspace
platform/x86: dell-ddv: Expose the battery manufacture date to userspace
platform/x86: dell-ddv: Implement the battery matching algorithm
power: supply: core: Add additional health status values
platform/x86/amd/hsmp: acpi: Add sysfs files to display HSMP telemetry
platform/x86/amd/hsmp: Report power via hwmon sensors
platform/x86/amd/hsmp: Use a single DRIVER_VERSION for all hsmp modules
platform/mellanox: mlxreg-dpu: Fix smatch warnings
platform: mellanox: nvsw-sn2200: Fix .items in nvsw_sn2201_busbar_hotplug
...
Pull documentation updates from Jonathan Corbet:
"A moderately busy cycle for documentation this time around:
- The most significant change is the replacement of the old
kernel-doc script (a monstrous collection of Perl regexes that
predates the Git era) with a Python reimplementation. That, too, is
a horrifying collection of regexes, but in a much cleaner and more
maintainable structure that integrates far better with the Sphinx
build system.
This change has been in linux-next for the full 6.15 cycle; the
small number of problems that turned up have been addressed,
seemingly to everybody's satisfaction. The Perl kernel-doc script
remains in tree (as scripts/kernel-doc.pl) and can be used with a
command-line option if need be. Unless some reason to keep it
around materializes, it will probably go away in 6.17.
Credit goes to Mauro Carvalho Chehab for doing all this work.
- Some RTLA documentation updates
- A handful of Chinese translations
- The usual collection of typo fixes, general updates, etc"
* tag 'docs-6.16' of git://git.lwn.net/linux: (85 commits)
Docs: doc-guide: update sphinx.rst Sphinx version number
docs: doc-guide: clarify latest theme usage
Documentation/scheduler: Fix typo in sched-stats domain field description
scripts: kernel-doc: prevent a KeyError when checking output
docs: kerneldoc.py: simplify exception handling logic
MAINTAINERS: update linux-doc entry to cover new Python scripts
docs: align with scripts/syscall.tbl migration
Documentation: NTB: Fix typo
Documentation: ioctl-number: Update table intro
docs: conf.py: drop backward support for old Sphinx versions
Docs: driver-api/basics: add kobject_event interfaces
Docs: relay: editing cleanups
docs: fix "incase" typo in coresight/panic.rst
Fix spelling error for 'parallel'
docs: admin-guide: fix typos in reporting-issues.rst
docs: dmaengine: add explanation for DMA_ASYNC_TX capability
Documentation: leds: improve readibility of multicolor doc
docs: fix typo in firmware-related section
docs: Makefile: Inherit PYTHONPYCACHEPREFIX setting as env variable
Documentation: ioctl-number: Update outdated submission info
...
Pull x86 resource control updates from Borislav Petkov:
"Carve out the resctrl filesystem-related code into fs/resctrl/ so that
multiple architectures can share the fs API for manipulating their
respective hw resource control implementation.
This is the second step in the work towards sharing the resctrl
filesystem interface, the next one being plugging ARM's MPAM into the
aforementioned fs API"
* tag 'x86_cache_for_v6.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits)
MAINTAINERS: Add reviewers for fs/resctrl
x86,fs/resctrl: Move the resctrl filesystem code to live in /fs/resctrl
x86/resctrl: Always initialise rid field in rdt_resources_all[]
x86/resctrl: Relax some asm #includes
x86/resctrl: Prefer alloc(sizeof(*foo)) idiom in rdt_init_fs_context()
x86/resctrl: Squelch whitespace anomalies in resctrl core code
x86/resctrl: Move pseudo lock prototypes to include/linux/resctrl.h
x86/resctrl: Fix types in resctrl_arch_mon_ctx_{alloc,free}() stubs
x86/resctrl: Move enum resctrl_event_id to resctrl.h
x86/resctrl: Move the filesystem bits to headers visible to fs/resctrl
fs/resctrl: Add boiler plate for external resctrl code
x86/resctrl: Add 'resctrl' to the title of the resctrl documentation
x86/resctrl: Split trace.h
x86/resctrl: Expand the width of domid by replacing mon_data_bits
x86/resctrl: Add end-marker to the resctrl_event_id enum
x86/resctrl: Move is_mba_sc() out of core.c
x86/resctrl: Drop __init/__exit on assorted symbols
x86/resctrl: Resctrl_exit() teardown resctrl but leave the mount point
x86/resctrl: Check all domains are offline in resctrl_exit()
x86/resctrl: Rename resctrl_sched_in() to begin with "resctrl_arch_"
...
Make frequently fetched telemetry available via sysfs. These parameters
do not fit in hwmon sensor model, hence make them available via sysfs.
Create following sysfs files per acpi device node.
* c0_residency_input
* prochot_status
* smu_fw_version
* protocol_version
* ddr_max_bw(GB/s)
* ddr_utilised_bw_input(GB/s)
* ddr_utilised_bw_perc_input(%)
* mclk_input(MHz)
* fclk_input(MHz)
* clk_fmax(MHz)
* clk_fmin(MHz)
* cclk_freq_limit_input(MHz)
* pwr_current_active_freq_limit(MHz)
* pwr_current_active_freq_limit_source
Signed-off-by: Suma Hegde <suma.hegde@amd.com>
Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20250506101542.200811-3-suma.hegde@amd.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
The following register contains bits that indicate the cause for the
previous reset.
PMx000000C0 (FCH::PM::S5_RESET_STATUS)
This is useful for debug. The reasons for reset are broken into 6 high level
categories. Decode it by category and print during boot.
Specifics within a category are split off into debugging documentation.
The register is accessed indirectly through a "PM" port in the FCH. Use
MMIO access in order to avoid restrictions with legacy port access.
Use a late_initcall() to ensure that MMIO has been set up before trying to
access the register.
This register was introduced with AMD Family 17h, so avoid access on older
families. There is no CPUID feature bit for this register.
[ bp: Simplify the reason dumping loop.
- merge a fix to not access an array element after the last one:
https://lore.kernel.org/r/20250505133609.83933-1-superm1@kernel.org
Reported-by: James Dutton <james.dutton@gmail.com>
]
[ mingo:
- Use consistent .rst formatting
- Fix 'Sleep' class field to 'ACPI-State'
- Standardize pin messages around the 'tripped' verbiage
- Remove reference to ring-buffer printing & simplify the wording
- Use curly braces for multi-line conditional statements ]
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Co-developed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/20250422234830.2840784-6-superm1@kernel.org
Pull x86 build updates from Ingo Molnar:
- Drop CRC-32 checksum and the build tool that generates it (Ard
Biesheuvel)
- Fix broken copy command in genimage.sh when making isoimage (Nir
Lichtman)
* tag 'x86-build-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/boot: Add back some padding for the CRC-32 checksum
x86/boot: Drop CRC-32 checksum and the build tool that generates it
x86/build: Fix broken copy command in genimage.sh when making isoimage
Apart from some sanity checks on the size of setup.bin, the only
remaining task carried out by the arch/x86/boot/tools/build.c build tool
is generating the CRC-32 checksum of the bzImage. This feature was added
in commit
7d6e737c8d ("x86: add a crc32 checksum to the kernel image.")
without any motivation (or any commit log text, for that matter). This
checksum is not verified by any known bootloader, and given that
a) the checksum of the entire bzImage is reported by most tools (zlib,
rhash) as 0xffffffff and not 0x0 as documented,
b) the checksum is corrupted when the image is signed for secure boot,
which means that no distro ships x86 images with valid CRCs,
it seems quite unlikely that this checksum is being used, so let's just
drop it, along with the tool that generates it.
Instead, use simple file concatenation and truncation to combine the two
pieces into bzImage, and replace the checks on the size of the setup
block with a couple of ASSERT()s in the linker script.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ian Campbell <ijc@hellion.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250307164801.885261-2-ardb+git@google.com
HIGHMEM64G support was added in linux-2.3.25 to support (then)
high-end Pentium Pro and Pentium III Xeon servers with more than 4GB of
addressing, NUMA and PCI-X slots started appearing.
I have found no evidence of this ever being used in regular dual-socket
servers or consumer devices, all the users seem obsolete these days,
even by i386 standards:
- Support for NUMA servers (NUMA-Q, IBM x440, unisys) was already
removed ten years ago.
- 4+ socket non-NUMA servers based on Intel 450GX/450NX, HP F8 and
ServerWorks ServerSet/GrandChampion could theoretically still work
with 8GB, but these were exceptionally rare even 20 years ago and
would have usually been equipped with than the maximum amount of
RAM.
- Some SKUs of the Celeron D from 2004 had 64-bit mode fused off but
could still work in a Socket 775 mainboard designed for the later
Core 2 Duo and 8GB. Apparently most BIOSes at the time only allowed
64-bit CPUs.
- The rare Xeon LV "Sossaman" came on a few motherboards with
registered DDR2 memory support up to 16GB.
- In the early days of x86-64 hardware, there was sometimes the need
to run a 32-bit kernel to work around bugs in the hardware drivers,
or in the syscall emulation for 32-bit userspace. This likely still
works but there should never be a need for this any more.
PAE mode is still required to get access to the 'NX' bit on Atom
'Pentium M' and 'Core Duo' CPUs.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250226213714.4040853-6-arnd@kernel.org
Pull Documentation updates from Jonathan Corbet:
- Quite a bit of Chinese and Spanish translation work
- Clarifying that Git commit IDs >12chars are OK
- A new nvme-multipath document
- A reorganization of the admin-guide top-level page to make it
readable
- Clarification of the role of Acked-by and maintainer discretion on
their acceptance
- Some reorganization of debugging-oriented docs
... and typo fixes, documentation updates, etc as usual
* tag 'docs-6.14' of git://git.lwn.net/linux: (50 commits)
Documentation: Fix x86_64 UEFI outdated references to elilo
Documentation/sysctl: Add timer_migration to kernel.rst
docs/mm: Physical memory: Remove zone_t
docs: submitting-patches: clarify that signers may use their discretion on tags
docs: submitting-patches: clarify difference between Acked-by and Reviewed-by
docs: submitting-patches: clarify Acked-by and introduce "# Suffix"
Documentation: bug-hunting.rst: remove odd contact information
docs/zh_CN: Add sak index Chinese translation
doc: module: DEFAULT_SYMBOL_NAMESPACE must be defined before #includes
doc: module: Fix documented type of namespace
Documentation/kernel-parameters: Fix a reference to vga-softcursor.rst
docs/zh_CN: Add landlock index Chinese translation
Documentation: Fix typo localmodonfig -> localmodconfig
overlayfs.rst: Fix and improve grammar
docs/zh_CN: Add siphash index Chinese translation
docs/zh_CN: Add security IMA-templates Chinese translation
docs/zh_CN: Add security digsig Chinese translation
Align git commit ID abbreviation guidelines and checks
docs: process: submitting-patches: split canonical patch format section
docs/zh_CN: Add security lsm Chinese translation
...
Pull x86 cleanups from Ingo Molnar:
"Miscellaneous x86 cleanups and typo fixes, and also the removal of
the 'disablelapic' boot parameter"
* tag 'x86-cleanups-2025-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/ioapic: Remove a stray tab in the IO-APIC type string
x86/cpufeatures: Remove "AMD" from the comments to the AMD-specific leaf
Documentation/kernel-parameters: Fix a typo in kvm.enable_virt_at_load text
x86/cpu: Fix typo in x86_match_cpu()'s doc
x86/apic: Remove "disablelapic" cmdline option
Documentation: Merge x86-specific boot options doc into kernel-parameters.txt
x86/ioremap: Remove unused size parameter in remapping functions
x86/ioremap: Simplify setup_data mapping variants
x86/boot/compressed: Remove unused header includes from kaslr.c
Pull performance events updates from Ingo Molnar:
"Seqlock optimizations that arose in a perf context and were merged
into the perf tree:
- seqlock: Add raw_seqcount_try_begin (Suren Baghdasaryan)
- mm: Convert mm_lock_seq to a proper seqcount (Suren Baghdasaryan)
- mm: Introduce mmap_lock_speculate_{try_begin|retry} (Suren
Baghdasaryan)
- mm/gup: Use raw_seqcount_try_begin() (Peter Zijlstra)
Core perf enhancements:
- Reduce 'struct page' footprint of perf by mapping pages in advance
(Lorenzo Stoakes)
- Save raw sample data conditionally based on sample type (Yabin Cui)
- Reduce sampling overhead by checking sample_type in
perf_sample_save_callchain() and perf_sample_save_brstack() (Yabin
Cui)
- Export perf_exclude_event() (Namhyung Kim)
Uprobes scalability enhancements: (Andrii Nakryiko)
- Simplify find_active_uprobe_rcu() VMA checks
- Add speculative lockless VMA-to-inode-to-uprobe resolution
- Simplify session consumer tracking
- Decouple return_instance list traversal and freeing
- Ensure return_instance is detached from the list before freeing
- Reuse return_instances between multiple uretprobes within task
- Guard against kmemdup() failing in dup_return_instance()
AMD core PMU driver enhancements:
- Relax privilege filter restriction on AMD IBS (Namhyung Kim)
AMD RAPL energy counters support: (Dhananjay Ugwekar)
- Introduce topology_logical_core_id() (K Prateek Nayak)
- Remove the unused get_rapl_pmu_cpumask() function
- Remove the cpu_to_rapl_pmu() function
- Rename rapl_pmu variables
- Make rapl_model struct global
- Add arguments to the init and cleanup functions
- Modify the generic variable names to *_pkg*
- Remove the global variable rapl_msrs
- Move the cntr_mask to rapl_pmus struct
- Add core energy counter support for AMD CPUs
Intel core PMU driver enhancements:
- Support RDPMC 'metrics clear mode' feature (Kan Liang)
- Clarify adaptive PEBS processing (Kan Liang)
- Factor out functions for PEBS records processing (Kan Liang)
- Simplify the PEBS records processing for adaptive PEBS (Kan Liang)
Intel uncore driver enhancements: (Kan Liang)
- Convert buggy pmu->func_id use to pmu->registered
- Support more units on Granite Rapids"
* tag 'perf-core-2025-01-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
perf: map pages in advance
perf/x86/intel/uncore: Support more units on Granite Rapids
perf/x86/intel/uncore: Clean up func_id
perf/x86/intel: Support RDPMC metrics clear mode
uprobes: Guard against kmemdup() failing in dup_return_instance()
perf/x86: Relax privilege filter restriction on AMD IBS
perf/core: Export perf_exclude_event()
uprobes: Reuse return_instances between multiple uretprobes within task
uprobes: Ensure return_instance is detached from the list before freeing
uprobes: Decouple return_instance list traversal and freeing
uprobes: Simplify session consumer tracking
uprobes: add speculative lockless VMA-to-inode-to-uprobe resolution
uprobes: simplify find_active_uprobe_rcu() VMA checks
mm: introduce mmap_lock_speculate_{try_begin|retry}
mm: convert mm_lock_seq to a proper seqcount
mm/gup: Use raw_seqcount_try_begin()
seqlock: add raw_seqcount_try_begin
perf/x86/rapl: Add core energy counter support for AMD CPUs
perf/x86/rapl: Move the cntr_mask to rapl_pmus struct
perf/x86/rapl: Remove the global variable rapl_msrs
...
Pull x86 SEV updates from Borislav Petkov:
- A segmented Reverse Map table (RMP) is a across-nodes distributed
table of sorts which contains per-node descriptors of each node-local
4K page, denoting its ownership (hypervisor, guest, etc) in the realm
of confidential computing. Add support for such a table in order to
improve referential locality when accessing or modifying RMP table
entries
- Add support for reading the TSC in SNP guests by removing any
interference or influence the hypervisor might have, with the goal of
making a confidential guest even more independent from the hypervisor
* tag 'x86_sev_for_v6.14_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/sev: Add the Secure TSC feature for SNP guests
x86/tsc: Init the TSC for Secure TSC guests
x86/sev: Mark the TSC in a secure TSC guest as reliable
x86/sev: Prevent RDTSC/RDTSCP interception for Secure TSC enabled guests
x86/sev: Prevent GUEST_TSC_FREQ MSR interception for Secure TSC enabled guests
x86/sev: Change TSC MSR behavior for Secure TSC enabled guests
x86/sev: Add Secure TSC support for SNP guests
x86/sev: Relocate SNP guest messaging routines to common code
x86/sev: Carve out and export SNP guest messaging init routines
virt: sev-guest: Replace GFP_KERNEL_ACCOUNT with GFP_KERNEL
virt: sev-guest: Remove is_vmpck_empty() helper
x86/sev/docs: Document the SNP Reverse Map Table (RMP)
x86/sev: Add full support for a segmented RMP table
x86/sev: Treat the contiguous RMP table as a single RMP segment
x86/sev: Map only the RMP table entries instead of the full RMP range
x86/sev: Move the SNP probe routine out of the way
x86/sev: Require the RMPREAD instruction after Zen4
x86/sev: Add support for the RMPREAD instruction
x86/sev: Prepare for using the RMPREAD instruction to access the RMP
Problem: The x86_64 UEFI doc references Elilo which is an
unmaintained/orphaned bootloader project. Also, on x86_64 a bootloader
is technically not actually required since there is support for the
Linux EFI stub.
Solution: Remove the references to Elilo from the doc and refer to the
EFI stub doc page, update steps accordingly, and add more details about
creation of the EFI partition to improve clarity.
Signed-off-by: Nir Lichtman <nir@lichtman.org>
Link: https://lore.kernel.org/r/20250108113522.GA897677@lichtman.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Documentation/arch/x86/x86_64/boot-options.rst is causing unnecessary
confusion by being a second place where one can put x86 boot options.
Move them into the main one.
Drop removed ones like "acpi=ht", while at it.
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20241202190011.11979-1-bp@kernel.org
The init_size description of boot protocol has an example of the runtime
start address for the compressed bzImage. For non-relocatable kernel
it relies on the pref_address value (if not 0), but for relocatable case
only pays respect to the load_addres and kernel_alignment, and it is
inaccurate for the latter. Boot loader must consider the pref_address
as the Linux kernel relocates to it before being decompressed as nicely
described in this commit message a year ago:
43b1d3e68e ("kexec: Allocate kernel above bzImage's pref_address")
Due to this documentation inaccuracy some of the bootloaders (*) made a
mistake in the calculations and if kernel image is big enough, this may
lead to unbootable configurations.
*)
In particular, kexec-tools missed that and resently got a couple of
changes which will be part of v2.0.30 release. For the record,
commit 43b1d3e68e only fixed the kernel kexec implementation and
also missed to update the init_size description.
While at it, make an example C-like looking as it's done elsewhere in
the document and fix indentation as presribed by the reStructuredText
specifications, so the syntax highliting will work properly.
Fixes: 43b1d3e68e ("kexec: Allocate kernel above bzImage's pref_address")
Fixes: d297366ba6 ("x86: document new bzImage fields")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20241125105005.1616154-1-andriy.shevchenko@linux.intel.com
Pull x86 platform driver updates from Ilpo Järvinen:
- alienware WMAX thermal interface support
- Split ACPI and platform device based amd/hsmp drivers
- AMD X3D frequency/cache mode switching support
- asus thermal policy fixes
- Disable C1 auto-demotion in suspend to allow entering the deepest
C-states
- Fix volume buttons on Thinkpad X12 Detachable Tablet Gen 1
- Replace intel_scu_ipc "workaround" with 32-bit IO
- Correct *_show() function error handling in panasonic-laptop
- Gemini Lake P2SB devfn correction
- think-lmi Admin/System certificate authentication support
- Disable WMI devices for shutdown, refactoring continues
- Vexia EDU ATLA 10 tablet support
- Surface Pro 9 5G (Arm/QCOM) support
- Misc cleanups / refactoring / improvements
* tag 'platform-drivers-x86-v6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86: (69 commits)
platform/x86: p2sb: Cache correct PCI bar for P2SB on Gemini Lake
platform/x86: panasonic-laptop: Return errno correctly in show callback
Documentation: alienware-wmi: Describe THERMAL_INFORMATION operation 0x02
alienware-wmi: create_thermal_profile() no longer brute-forces IDs
alienware-wmi: Adds support to Alienware x17 R2
alienware-wmi: extends the list of supported models
alienware-wmi: order alienware_quirks[] alphabetically
platform/x86/intel/pmt: allow user offset for PMT callbacks
platform/x86/amd/hsmp: Change the error type
platform/x86/amd/hsmp: Add new error code and error logs
platform/x86/amd: amd_3d_vcache: Add sysfs ABI documentation
platform/x86/amd: amd_3d_vcache: Add AMD 3D V-Cache optimizer driver
intel-hid: fix volume buttons on Thinkpad X12 Detachable Tablet Gen 1
platform/x86/amd/hsmp: mark hsmp_msg_desc_table[] as maybe_unused
platform/x86: asus-wmi: Use platform_profile_cycle()
platform/x86: asus-wmi: Fix inconsistent use of thermal policies
platform/x86: hp: hp-bioscfg: remove redundant if statement
MAINTAINERS: Update ISHTP ECLITE maintainer entry
platform/x86: x86-android-tablets: Add support for Vexia EDU ATLA 10 tablet
platform/x86: x86-android-tablets: Add support for getting i2c_adapter by PCI parent devname()
...
Pull x86 mm updates from Ingo Molnar:
- Put cpumask_test_cpu() check in switch_mm_irqs_off() under
CONFIG_DEBUG_VM, to micro-optimize the context-switching code (Rik
van Riel)
- Add missing details in virtual memory layout (Kirill A. Shutemov)
* tag 'x86-mm-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm/tlb: Put cpumask_test_cpu() check in switch_mm_irqs_off() under CONFIG_DEBUG_VM
x86/mm/doc: Add missing details in virtual memory layout
Pull x86 splitlock updates from Ingo Molnar:
- Move Split and Bus lock code to a dedicated file (Ravi Bangoria)
- Add split/bus lock support for AMD (Ravi Bangoria)
* tag 'x86-splitlock-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/bus_lock: Add support for AMD
x86/split_lock: Move Split and Bus lock code to a dedicated file
