Commit Graph

108 Commits

Author SHA1 Message Date
Pasha Tatashin
9e2fd062fa liveupdate: luo_core: Live Update Orchestrator
Patch series "Live Update Orchestrator", v8.

This series introduces the Live Update Orchestrator, a kernel subsystem
designed to facilitate live kernel updates using a kexec-based reboot. 
This capability is critical for cloud environments, allowing hypervisors
to be updated with minimal downtime for running virtual machines.  LUO
achieves this by preserving the state of selected resources, such as
memory, devices and their dependencies, across the kernel transition.

As a key feature, this series includes support for preserving memfd file
descriptors, which allows critical in-memory data, such as guest RAM or
any other large memory region, to be maintained in RAM across the kexec
reboot.

The other series that use LUO, are VFIO [1], IOMMU [2], and PCI [3]
preservations.

Github repo of this series [4].

The core of LUO is a framework for managing the lifecycle of preserved
resources through a userspace-driven interface. Key features include:

- Session Management
  Userspace agent (i.e. luod [5]) creates named sessions, each
  represented by a file descriptor (via centralized agent that controls
  /dev/liveupdate). The lifecycle of all preserved resources within a
  session is tied to this FD, ensuring automatic kernel cleanup if the
  controlling userspace agent crashes or exits unexpectedly.

- File Preservation
  A handler-based framework allows specific file types (demonstrated
  here with memfd) to be preserved. Handlers manage the serialization,
  restoration, and lifecycle of their specific file types.

- File-Lifecycle-Bound State
  A new mechanism for managing shared global state whose lifecycle is
  tied to the preservation of one or more files. This is crucial for
  subsystems like IOMMU or HugeTLB, where multiple file descriptors may
  depend on a single, shared underlying resource that must be preserved
  only once.

- KHO Integration
  LUO drives the Kexec Handover framework programmatically to pass its
  serialized metadata to the next kernel. The LUO state is finalized and
  added to the kexec image just before the reboot is triggered. In the
  future this step will also be removed once stateless KHO is
  merged [6].

- Userspace Interface
  Control is provided via ioctl commands on /dev/liveupdate for creating
  and retrieving sessions, as well as on session file descriptors for
  managing individual files.

- Testing
  The series includes a set of selftests, including userspace API
  validation, kexec-based lifecycle tests for various session and file
  scenarios, and a new in-kernel test module to validate the FLB logic.




Introduce LUO, a mechanism intended to facilitate kernel updates while
keeping designated devices operational across the transition (e.g., via
kexec).  The primary use case is updating hypervisors with minimal
disruption to running virtual machines.  For userspace side of hypervisor
update we have copyless migration.  LUO is for updating the kernel.

This initial patch lays the groundwork for the LUO subsystem.

Further functionality, including the implementation of state transition
logic, integration with KHO, and hooks for subsystems and file
descriptors, will be added in subsequent patches.

Create a character device at /dev/liveupdate.

A new uAPI header, <uapi/linux/liveupdate.h>, will define the necessary
structures.  The magic number for IOCTL is registered in
Documentation/userspace-api/ioctl/ioctl-number.rst.

Link: https://lkml.kernel.org/r/20251125165850.3389713-1-pasha.tatashin@soleen.com
Link: https://lkml.kernel.org/r/20251125165850.3389713-2-pasha.tatashin@soleen.com
Link: https://lore.kernel.org/all/20251018000713.677779-1-vipinsh@google.com/ [1]
Link: https://lore.kernel.org/linux-iommu/20250928190624.3735830-1-skhawaja@google.com [2]
Link: https://lore.kernel.org/linux-pci/20250916-luo-pci-v2-0-c494053c3c08@kernel.org [3]
Link: https://github.com/googleprodkernel/linux-liveupdate/tree/luo/v8 [4]
Link: https://tinyurl.com/luoddesign [5]
Link: https://lore.kernel.org/all/20251020100306.2709352-1-jasonmiu@google.com [6]
Link: https://lore.kernel.org/all/20251115233409.768044-1-pasha.tatashin@soleen.com [7]
Link: https://github.com/soleen/linux/blob/luo/v8b03/diff.v7.v8 [8]
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Tested-by: David Matlack <dmatlack@google.com>
Cc: Aleksander Lobakin <aleksander.lobakin@intel.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Andriy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: anish kumar <yesanishhere@gmail.com>
Cc: Anna Schumaker <anna.schumaker@oracle.com>
Cc: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Chanwoo Choi <cw00.choi@samsung.com>
Cc: Chen Ridong <chenridong@huawei.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Daniel Wagner <wagi@kernel.org>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Jeffery <djeffery@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guixin Liu <kanie@linux.alibaba.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com>
Cc: Joel Granados <joel.granados@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lennart Poettering <lennart@poettering.net>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Leon Romanovsky <leonro@nvidia.com>
Cc: Lukas Wunner <lukas@wunner.de>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Matthew Maurer <mmaurer@google.com>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Myugnjoo Ham <myungjoo.ham@samsung.com>
Cc: Parav Pandit <parav@nvidia.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Saeed Mahameed <saeedm@nvidia.com>
Cc: Samiullah Khawaja <skhawaja@google.com>
Cc: Song Liu <song@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Stuart Hayes <stuart.w.hayes@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Thomas Weißschuh <linux@weissschuh.net>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: William Tu <witu@nvidia.com>
Cc: Yoann Congal <yoann.congal@smile.fr>
Cc: Zijun Hu <quic_zijuhu@quicinc.com>
Cc: Pratyush Yadav <ptyadav@amazon.de>
Cc: Zhu Yanjun <yanjun.zhu@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-27 14:24:37 -08:00
Haren Myneni
043439ad1a powerpc/pseries: Define papr-hvpipe ioctl
PowerPC FW introduced HVPIPE RTAS calls such as
ibm,send-hvpipe-msg and ibm,receive-hvpipe-msg for the user space
to exchange information with different sources such as Hardware
Management Consoles (HMC).

HVPIPE_IOC_CREATE_HANDLE is defined to use /dev/papr-hvpipe
interface for ibm,send-hvpipe-msg and ibm,receive-hvpipe-msg
RTAS calls.

Also defined papr_hvpipe_hdr which will added in the payload
that is passed between the kernel and the user space.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Tested-by: Shashank MS <shashank.gowda@in.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250909084402.1488456-2-haren@linux.ibm.com
2025-09-15 13:38:39 +05:30
Linus Torvalds
b1cce98493 Merge tag 'docs-6.17' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
 "It has been a relatively busy cycle for docs, especially the build
  system:

   - The Perl kernel-doc script was added to 2.3.52pre1 just after the
     turn of the millennium. Over the following 25 years, it accumulated
     a vast amount of cruft, all in a language few people want to deal
     with anymore. Mauro's Python replacement in 6.16 faithfully
     reproduced all of the cruft in the hope of avoiding regressions.

     Now that we have a more reasonable code base, though, we can work
     on cleaning it up; many of the changes this time around are toward
     that end.

   - A reorganization of the ext4 docs into the usual TOC format.

   - Various Chinese translations and updates.

   - A new script from Mauro to help with docs-build testing.

   - A new document for linked lists

   - A sweep through MAINTAINERS fixing broken GitHub git:// repository
     links.

  ...and lots of fixes and updates"

* tag 'docs-6.17' of git://git.lwn.net/linux: (147 commits)
  scripts: add origin commit identification based on specific patterns
  sphinx: kernel_abi: fix performance regression with O=<dir>
  Documentation: core-api: entry: Replace deprecated KVM entry/exit functions
  docs: fault-injection: drop reference to md-faulty
  docs: document linked lists
  scripts: kdoc: make it backward-compatible with Python 3.7
  docs: kernel-doc: emit warnings for ancient versions of Python
  Documentation/rtla: Describe exit status
  Documentation/rtla: Add include common_appendix.rst
  docs: kernel: Clarify printk_ratelimit_burst reset behavior
  Documentation: ioctl-number: Don't repeat macro names
  Documentation: ioctl-number: Shorten macros table
  Documentation: ioctl-number: Correct full path to papr-physical-attestation.h
  Documentation: ioctl-number: Extend "Include File" column width
  Documentation: ioctl-number: Fix linuxppc-dev mailto link
  overlayfs.rst: fix typos
  docs: kdoc: emit a warning for ancient versions of Python
  docs: kdoc: clean up check_sections()
  docs: kdoc: directly access the always-there KdocItem fields
  docs: kdoc: straighten up dump_declaration()
  ...
2025-07-31 08:36:51 -07:00
Bagas Sanjaya
cae5841583 Documentation: ioctl-number: Don't repeat macro names
Don't repeat mentioning macro names (_IO, _IOW, _IOR, and _IOWR) to
keep the wording effective.

Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20250715024258.16882-3-bagasdotme@gmail.com
2025-07-15 14:04:30 -06:00
Bagas Sanjaya
67ffcabd2d Documentation: ioctl-number: Shorten macros table
The macros table has three columns: the second one is "an" and the
third one writes "an ioctl with ... parameters". Simplify the table
by adding heading row that indicates macro name and accepted
parameters.

Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20250715024258.16882-2-bagasdotme@gmail.com
2025-07-15 14:04:30 -06:00
Bagas Sanjaya
44bdcff53f Documentation: ioctl-number: Correct full path to papr-physical-attestation.h
Commit 03c9d1a5a3 ("Documentation: Fix description format for
powerpc RTAS ioctls") fixes Sphinx warning by chopping arch/ path
component of papr-physical-attestation.h to fit existing "Include File"
column. Now that the column has been widened just enough for that
header file, add back its arch/ path component.

Reviewed-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Acked-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20250714015711.14525-4-bagasdotme@gmail.com
2025-07-15 14:02:23 -06:00
Bagas Sanjaya
15afd5def8 Documentation: ioctl-number: Extend "Include File" column width
Extend width of "Include File" column to fit full path to
papr-physical-attestation.h in later commit.

Reviewed-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Acked-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20250714015711.14525-3-bagasdotme@gmail.com
2025-07-15 14:02:23 -06:00
Bagas Sanjaya
3dfa97bd93 Documentation: ioctl-number: Fix linuxppc-dev mailto link
Spell out full Linux PPC mailing list address like other subsystem
mailing lists listed in the table.

Reviewed-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Acked-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20250714015711.14525-2-bagasdotme@gmail.com
2025-07-15 14:02:05 -06:00
Jens Axboe
1cea5180f2 block: remove pktcdvd driver
This driver has long outlived it's utility, and it's broken and unloved.
The main use case for this was direct mount with UDF of cd-rw drives
that required 32kb packets. It would collect writes into that size and
write them out in multiples of that. That's not a common use case
anymore, the world has moved on from those kinds of media. To make
matters worse, it's actively breaking setups where it's not even
required or useful.

Link: https://lore.kernel.org/linux-block/fxg6dksau4jsk3u5xldlyo2m7qgiux6vtdrz5rywseotsouqdv@urcrwz6qtd3r/
Link: https://lore.kernel.org/linux-block/dcc4836e-6da9-4208-ad27-bbd44b3a2063@kernel.dk/
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-07 07:02:42 -06:00
Linus Torvalds
c26f4fbd58 Merge tag 'char-misc-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char / misc / iio driver updates from Greg KH:
 "Here is the big char/misc/iio and other small driver subsystem pull
  request for 6.16-rc1.

  Overall, a lot of individual changes, but nothing major, just the
  normal constant forward progress of new device support and cleanups to
  existing subsystems. Highlights in here are:

   - Large IIO driver updates and additions and device tree changes

   - Android binder bugfixes and logfile fixes

   - mhi driver updates

   - comedi driver updates

   - counter driver updates and additions

   - coresight driver updates and additions

   - echo driver removal as there are no in-kernel users of it

   - nvmem driver updates

   - spmi driver updates

   - new amd-sbi driver "subsystem" and drivers added

   - rust miscdriver binding documentation fix

   - other small driver fixes and updates (uio, w1, acrn, hpet,
     xillybus, cardreader drivers, fastrpc and others)

  All of these have been in linux-next for quite a while with no
  reported problems"

* tag 'char-misc-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (390 commits)
  binder: fix yet another UAF in binder_devices
  counter: microchip-tcb-capture: Add watch validation support
  dt-bindings: iio: adc: Add ROHM BD79100G
  iio: adc: add support for Nuvoton NCT7201
  dt-bindings: iio: adc: add NCT7201 ADCs
  iio: chemical: Add driver for SEN0322
  dt-bindings: trivial-devices: Document SEN0322
  iio: adc: ad7768-1: reorganize driver headers
  iio: bmp280: zero-init buffer
  iio: ssp_sensors: optimalize -> optimize
  HID: sensor-hub: Fix typo and improve documentation
  iio: admv1013: replace redundant ternary operator with just len
  iio: chemical: mhz19b: Fix error code in probe()
  iio: adc: at91-sama5d2: use IIO_DECLARE_BUFFER_WITH_TS
  iio: accel: sca3300: use IIO_DECLARE_BUFFER_WITH_TS
  iio: adc: ad7380: use IIO_DECLARE_DMA_BUFFER_WITH_TS
  iio: adc: ad4695: rename AD4695_MAX_VIN_CHANNELS
  iio: adc: ad4695: use IIO_DECLARE_DMA_BUFFER_WITH_TS
  iio: introduce IIO_DECLARE_BUFFER_WITH_TS macros
  iio: make IIO_DMA_MINALIGN minimum of 8 bytes
  ...
2025-06-06 11:50:47 -07:00
Linus Torvalds
3e443d1673 Merge tag 'docs-6.16' of git://git.lwn.net/linux
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
  ...
2025-05-27 11:22:19 -07:00
Akshay Gupta
35ac2034db misc: amd-sbi: Add support for AMD_SBI IOCTL
The present sbrmi module only support reporting power via hwmon.
However, AMD data center range of processors support various
system management functionality using custom protocols defined in
Advanced Platform Management Link (APML) specification.

Register a miscdevice, which creates a device /dev/sbrmiX with an IOCTL
interface for the user space to invoke the APML Mailbox protocol, which
is already defined in sbrmi_mailbox_xfer().

The APML protocols depend on a set of RMI registers. Having an IOCTL
as a single entry point will help in providing synchronization among
these protocols as multiple transactions on RMI register set may
create race condition.
Support for other protocols will be added in subsequent patches.

APML mailbox protocol returns additional error codes written by
SMU firmware in the out-bound register 0x37. These errors include,
invalid core, message not supported over platform and
others. This additional error codes can be used to provide more
details to user space.

Open-sourced and widely used https://github.com/amd/esmi_oob_library
will continue to provide user-space programmable API.

Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Signed-off-by: Akshay Gupta <akshay.gupta@amd.com>
Link: https://lore.kernel.org/r/20250428063034.2145566-7-akshay.gupta@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21 14:44:40 +02:00
Bagas Sanjaya
d5048aca8d Documentation: ioctl-number: Update table intro
Introduction paragraph to the ioctl numbers table states that only
ioctls in up to ancient Linux kernel version (v2.6.31) for x86 arch are
listed. This is inaccurate as the table also lists ioctls from non-x86
archs and the kernel is continously developed (currently in v6.x).

Update the paragraph accordingly.

Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20250508005838.8381-2-bagasdotme@gmail.com>
2025-05-19 08:08:57 -06:00
Bagas Sanjaya
40e71e32c8 Documentation: ioctl-number: Update outdated submission info
Much like device numbers that used to be assigned by LANANA (see commit
ebdf4040c1 ("Documentation: update the devices.txt documentation"),
ioctl numbers list is maintained by general kernel community nowadays
instead of contacting Michael directly as he's long stepped down from
kernel-related activity (his last LKML message was from 2003 [1] and
he's in CREDITS since the beginning of kernel's git history). Also,
patch (including one to update ioctl numbers list) submission now
follows process as described in
Documentation/process/submitting-patches.rst rather than sending
patches directly to Linus as in the distant past.

Update the docs to reflect that.

Link: https://lore.kernel.org/r/200305261446.h4QEkBVv023861@duracef.shout.net/ [1]
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20250502074504.26933-2-bagasdotme@gmail.com>
2025-05-07 00:53:22 -06:00
Haren Myneni
03c9d1a5a3 Documentation: Fix description format for powerpc RTAS ioctls
Fix the description format for the following build warnings:

"Documentation/userspace-api/ioctl/ioctl-number.rst:369:
ERROR: Malformed table. Text in column margin in table line 301.

0xB2  03-05 arch/powerpc/include/uapi/asm/papr-indices.h
powerpc/pseries indices API
                            <mailto:linuxppc-dev>
0xB2  06-07 arch/powerpc/include/uapi/asm/papr-platform-dump.h
powerpc/pseries Platform Dump API
                            <mailto:linuxppc-dev>
0xB2  08  arch/powerpc/include/uapi/asm/papr-physical-attestation.h
powerpc/pseries Physical Attestation API
                            <mailto:linuxppc-dev>"

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Fixes: 43d869ac25 ("powerpc/pseries: Define papr_indices_io_block for papr-indices ioctls")
Fixes: 8aa9efc0be ("powerpc/pseries: Add papr-platform-dump character driver for dump retrieval")
Fixes: 86900ab620 ("powerpc/pseries: Add a char driver for physical-attestation RTAS")
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Closes: https://lore.kernel.org/linux-next/20250429181707.7848912b@canb.auug.org.au/
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250430022847.1118093-1-haren@linux.ibm.com
2025-05-02 09:57:24 +05:30
Haren Myneni
86900ab620 powerpc/pseries: Add a char driver for physical-attestation RTAS
The RTAS call ibm,physical-attestation is used to retrieve
information about the trusted boot state of the firmware and
hypervisor on the system, and also Trusted Platform Modules (TPM)
data if the system is TCG 2.0 compliant.

This RTAS interface expects the caller to define different command
structs such as RetrieveTPMLog, RetrievePlatformCertificat and etc,
in a work area with a maximum size of 4K bytes and the response
buffer will be returned in the same work area.

The current implementation of this RTAS function is in the user
space but allocation of the work area is restricted with the system
lockdown. So this patch implements this RTAS function in the kernel
and expose to the user space with open/ioctl/read interfaces.

PAPR (2.13+ 21.3 ibm,physical-attestation) defines RTAS function:
- Pass the command struct to obtain the response buffer for the
  specific command.
- This RTAS function is sequence RTAS call and has to issue RTAS
  call multiple times to get the complete response buffer (max 64K).
  The hypervisor expects the first RTAS call with the sequence 1 and
  the subsequent calls with the sequence number returned from the
  previous calls.

Expose these interfaces to user space with a
/dev/papr-physical-attestation character device using the following
programming model:

 int devfd = open("/dev/papr-physical-attestation");
 int fd = ioctl(devfd, PAPR_PHY_ATTEST_IOC_HANDLE,
                      struct papr_phy_attest_io_block);
 - The user space defines the command struct and requests the
   response for any command.
 - Obtain the complete response buffer and returned the buffer as
   blob to the command specific FD.
 size = read(fd, buf, len);
 - Can retrieve the response buffer once or multiple times until the
   end of BLOB buffer.

Implemented this new kernel ABI support in librtas library for
system lockdown

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250416225743.596462-8-haren@linux.ibm.com
2025-04-17 11:42:30 +05:30
Haren Myneni
8aa9efc0be powerpc/pseries: Add papr-platform-dump character driver for dump retrieval
ibm,platform-dump RTAS call in combination with writable mapping
/dev/mem is issued to collect platform dump from the hypervisor
and may need multiple calls to get the complete dump. The current
implementation uses rtas_platform_dump() API provided by librtas
library to issue these RTAS calls. But /dev/mem access by the
user space is prohibited under system lockdown.

The solution should be to restrict access to RTAS function in user
space and provide kernel interfaces to collect dump. This patch
adds papr-platform-dump character driver and expose standard
interfaces such as open / ioctl/ read to user space in ways that
are compatible with lockdown.

PAPR (7.3.3.4.1 ibm,platform-dump) provides a method to obtain
the complete dump:
- Each dump will be identified by ID called dump tag.
- A sequence of RTAS calls have to be issued until retrieve the
  complete dump. The hypervisor expects the first RTAS call with
  the sequence 0 and the subsequent calls with the sequence
  number returned from the previous calls.
- The hypervisor returns "dump complete" status once the complete
  dump is retrieved. But expects one more RTAS call from the
  partition with the NULL buffer to invalidate dump which means
  the dump will be removed in the hypervisor.
- Sequence of calls are allowed with different dump IDs at the
  same time but not with the same dump ID.

Expose these interfaces to user space with a /dev/papr-platform-dump
character device using the following programming model:

   int devfd = open("/dev/papr-platform-dump", O_RDONLY);
   int fd = ioctl(devfd,PAPR_PLATFORM_DUMP_IOC_CREATE_HANDLE, &dump_id)
	- Restrict user space to access with the same dump ID.
          Typically we do not expect user space requests the dump
          again for the same dump ID.
   char *buf = malloc(size);
   length = read(fd, buf, size);
        - size should be minimum 1K based on PAPR and  <= 4K based
          on RTAS work area size. It will be restrict to RTAS work
          area size. Using 4K work area based on the current
          implementation in librtas library
        - Each read call issue RTAS call to get the data based on
          the size requirement and returns bytes returned from the
          hypervisor
        - If the previous call returns dump complete status, the
          next read returns 0 like EOF.
   ret = ioctl(PAPR_PLATFORM_DUMP_IOC_INVALIDATE, &dump_id)
	- RTAS call with NULL buffer to invalidates the dump.

The read API should use the file descriptor obtained from ioctl
based on dump ID so that gets dump contents for the corresponding
dump ID. Implemented support in librtas (rtas_platform_dump()) for
this new ABI to support system lockdown.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Tested-by: Sathvika Vasireddy <sv@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250416225743.596462-7-haren@linux.ibm.com
2025-04-17 11:42:29 +05:30
Haren Myneni
43d869ac25 powerpc/pseries: Define papr_indices_io_block for papr-indices ioctls
To issue ibm,get-indices, ibm,set-dynamic-indicator and
ibm,get-dynamic-sensor-state in the user space, the RMO buffer is
allocated for the work area which is restricted under system
lockdown. So instead of user space execution, the kernel will
provide /dev/papr-indices interface to execute these RTAS calls.

The user space assigns data in papr_indices_io_block struct
depends on the specific HCALL and passes to the following ioctls:

PAPR_INDICES_IOC_GET:		Use for ibm,get-indices. Returns a
				get-indices handle fd to read data.
PAPR_DYNAMIC_SENSOR_IOC_GET:	Use for  ibm,get-dynamic-sensor-state.
				Updates the sensor state in
				papr_indices_io_block.dynamic_param.state

PAPR_DYNAMIC_INDICATOR_IOC_SET:	Use for ibm,set-dynamic-indicator.
				Sets the new state for the input
				indicator.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Tested-by: Sathvika Vasireddy <sv@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250416225743.596462-3-haren@linux.ibm.com
2025-04-17 11:42:29 +05:30
Linus Torvalds
0a87d6bb6f Merge tag 'powerpc-6.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull more powerpc updates from Michael Ellerman:

 - Remove the IBM CAPI (cxl) driver

Thanks to Andrew Donnellan.

* tag 'powerpc-6.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  docs: Fix references to IBM CAPI (cxl) removal version
  cxl: Remove driver
2025-04-02 12:35:49 -07:00
Michael Ellerman
892c4e465c docs: Fix references to IBM CAPI (cxl) removal version
The IBM CAPI (cxl) driver was removed in 6.15, not 6.14.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2025-04-02 23:09:52 +11:00
Michael Ellerman
64f7efb0f5 Merge branch 'topic/cxl' into next
This merges in the removal of the IBM CAPI "cxl" driver.
2025-04-02 11:07:44 +11:00
Linus Torvalds
0ccff074d6 Merge tag 'for-linus-fwctl' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma
Pull fwctl subsystem from Jason Gunthorpe:
 "fwctl is a new subsystem intended to bring some common rules and order
  to the growing pattern of exposing a secure FW interface directly to
  userspace.

  Unlike existing places like RDMA/DRM/VFIO/uacce that are exposing a
  device for datapath operations fwctl is focused on debugging,
  configuration and provisioning of the device. It will not have the
  necessary features like interrupt delivery to support a datapath.

  This concept is similar to the long standing practice in the "HW" RAID
  space of having a device specific misc device to manage the RAID
  controller FW. fwctl generalizes this notion of a companion debug and
  management interface that goes along with a dataplane implemented in
  an appropriate subsystem.

  There have been three LWN articles written discussing various aspects
  of this:

	https://lwn.net/Articles/955001/
	https://lwn.net/Articles/969383/
	https://lwn.net/Articles/990802/

  This includes three drivers to launch the subsystem:

   - CXL provides a vendor scheme for executing commands and a way to
     learn the 'command effects' (ie the security properties) of such
     commands. The fwctl driver allows access to these mechanism within
     the fwctl security model

   - mlx5 is family of networking products, the driver supports all
     current Mellanox HW still receiving FW feature updates. This
     includes RDMA multiprotocol NICs like ConnectX and the Bluefield
     family of Smart NICs.

   - AMD/Pensando Distributed Services card is a multi protocol Smart
     NIC with a multi PCI function design. fwctl works on the management
     PCI function following a 'command effects' model similar to CXL"

* tag 'for-linus-fwctl' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (30 commits)
  pds_fwctl: add Documentation entries
  pds_fwctl: add rpc and query support
  pds_fwctl: initial driver framework
  pds_core: add new fwctl auxiliary_device
  pds_core: specify auxiliary_device to be created
  pds_core: make pdsc_auxbus_dev_del() void
  cxl: Fixup kdoc issues for include/cxl/features.h
  fwctl/cxl: Add documentation to FWCTL CXL
  cxl/test: Add Set Feature support to cxl_test
  cxl/test: Add Get Feature support to cxl_test
  cxl: Add support to handle user feature commands for set feature
  cxl: Add support to handle user feature commands for get feature
  cxl: Add support for fwctl RPC command to enable CXL feature commands
  cxl: Move cxl feature command structs to user header
  cxl: Add FWCTL support to CXL
  mlx5: Create an auxiliary device for fwctl_mlx5
  fwctl/mlx5: Support for communicating with mlx5 fw
  fwctl: Add documentation
  fwctl: FWCTL_RPC to execute a Remote Procedure Call to device firmware
  taint: Add TAINT_FWCTL
  ...
2025-03-29 10:45:20 -07:00
Linus Torvalds
2e3fcbcc3b Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI updates from James Bottomley:
 "Updates to the usual drivers (scsi_debug, ufs, lpfc, st, fnic, mpi3mr,
  mpt3sas) and the removal of cxlflash.

  The only non-trivial core change is an addition to unit attention
  handling to recognize UAs for power on/reset and new media so the tape
  driver can use it"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (107 commits)
  scsi: st: Tighten the page format heuristics with MODE SELECT
  scsi: st: ERASE does not change tape location
  scsi: st: Fix array overflow in st_setup()
  scsi: target: tcm_loop: Fix wrong abort tag
  scsi: lpfc: Restore clearing of NLP_UNREG_INP in ndlp->nlp_flag
  scsi: hisi_sas: Fixed failure to issue vendor specific commands
  scsi: fnic: Remove unnecessary NUL-terminations
  scsi: fnic: Remove redundant flush_workqueue() calls
  scsi: core: Use a switch statement when attaching VPD pages
  scsi: ufs: renesas: Add initialization code for R-Car S4-8 ES1.2
  scsi: ufs: renesas: Add reusable functions
  scsi: ufs: renesas: Refactor 0x10ad/0x10af PHY settings
  scsi: ufs: renesas: Remove register control helper function
  scsi: ufs: renesas: Add register read to remove save/set/restore
  scsi: ufs: renesas: Replace init data by init code
  scsi: ufs: dt-bindings: renesas,ufs: Add calibration data
  scsi: mpi3mr: Task Abort EH Support
  scsi: storvsc: Don't report the host packet status as the hv status
  scsi: isci: Make most module parameters static
  scsi: megaraid_sas: Make most module parameters static
  ...
2025-03-26 19:57:34 -07:00
Linus Torvalds
9b960d8cd6 Merge tag 'for-6.15/block-20250322' of git://git.kernel.dk/linux
Pull block updates from Jens Axboe:

 - Fixes for integrity handling

 - NVMe pull request via Keith:
      - Secure concatenation for TCP transport (Hannes)
      - Multipath sysfs visibility (Nilay)
      - Various cleanups (Qasim, Baruch, Wang, Chen, Mike, Damien, Li)
      - Correct use of 64-bit BARs for pci-epf target (Niklas)
      - Socket fix for selinux when used in containers (Peijie)

 - MD pull request via Yu:
      - fix recovery can preempt resync (Li Nan)
      - fix md-bitmap IO limit (Su Yue)
      - fix raid10 discard with REQ_NOWAIT (Xiao Ni)
      - fix raid1 memory leak (Zheng Qixing)
      - fix mddev uaf (Yu Kuai)
      - fix raid1,raid10 IO flags (Yu Kuai)
      - some refactor and cleanup (Yu Kuai)

 - Series cleaning up and fixing bugs in the bad block handling code

 - Improve support for write failure simulation in null_blk

 - Various lock ordering fixes

 - Fixes for locking for debugfs attributes

 - Various ublk related fixes and improvements

 - Cleanups for blk-rq-qos wait handling

 - blk-throttle fixes

 - Fixes for loop dio and sync handling

 - Fixes and cleanups for the auto-PI code

 - Block side support for hardware encryption keys in blk-crypto

 - Various cleanups and fixes

* tag 'for-6.15/block-20250322' of git://git.kernel.dk/linux: (105 commits)
  nvmet: replace max(a, min(b, c)) by clamp(val, lo, hi)
  nvme-tcp: fix selinux denied when calling sock_sendmsg
  nvmet: pci-epf: Always configure BAR0 as 64-bit
  nvmet: Remove duplicate uuid_copy
  nvme: zns: Simplify nvme_zone_parse_entry()
  nvmet: pci-epf: Remove redundant 'flush_workqueue()' calls
  nvmet-fc: Remove unused functions
  nvme-pci: remove stale comment
  nvme-fc: Utilise min3() to simplify queue count calculation
  nvme-multipath: Add visibility for queue-depth io-policy
  nvme-multipath: Add visibility for numa io-policy
  nvme-multipath: Add visibility for round-robin io-policy
  nvmet: add tls_concat and tls_key debugfs entries
  nvmet-tcp: support secure channel concatenation
  nvmet: Add 'sq' argument to alloc_ctrl_args
  nvme-fabrics: reset admin connection for secure concatenation
  nvme-tcp: request secure channel concatenation
  nvme-keyring: add nvme_tls_psk_refresh()
  nvme: add nvme_auth_derive_tls_psk()
  nvme: add nvme_auth_generate_digest()
  ...
2025-03-26 18:08:55 -07:00
Nuno Das Neves
621191d709 Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs
Provide a set of IOCTLs for creating and managing child partitions when
running as root partition on Hyper-V. The new driver is enabled via
CONFIG_MSHV_ROOT.

A brief overview of the interface:

MSHV_CREATE_PARTITION is the entry point, returning a file descriptor
representing a child partition. IOCTLs on this fd can be used to map
memory, create VPs, etc.

Creating a VP returns another file descriptor representing that VP which
in turn has another set of corresponding IOCTLs for running the VP,
getting/setting state, etc.

MSHV_ROOT_HVCALL is a generic "passthrough" hypercall IOCTL which can be
used for a number of partition or VP hypercalls. This is for hypercalls
that do not affect any state in the kernel driver, such as getting and
setting VP registers and partition properties, translating addresses,
etc. It is "passthrough" because the binary input and output for the
hypercall is only interpreted by the VMM - the kernel driver does
nothing but insert the VP and partition id where necessary (which are
always in the same place), and execute the hypercall.

Co-developed-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com>
Signed-off-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com>
Co-developed-by: Jinank Jain <jinankjain@microsoft.com>
Signed-off-by: Jinank Jain <jinankjain@microsoft.com>
Co-developed-by: Mukesh Rathor <mrathor@linux.microsoft.com>
Signed-off-by: Mukesh Rathor <mrathor@linux.microsoft.com>
Co-developed-by: Muminul Islam <muislam@microsoft.com>
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Co-developed-by: Praveen K Paladugu <prapal@linux.microsoft.com>
Signed-off-by: Praveen K Paladugu <prapal@linux.microsoft.com>
Co-developed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Co-developed-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Roman Kisel <romank@linux.microsoft.com>
Link: https://lore.kernel.org/r/1741980536-3865-11-git-send-email-nunodasneves@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <1741980536-3865-11-git-send-email-nunodasneves@linux.microsoft.com>
2025-03-21 18:24:22 +00:00
Andrew Donnellan
5a0fcb0ef5 cxl: Remove driver
Remove the cxl driver that provides support for the IBM Coherent
Accelerator Processor Interface. Revert or clean up associated code in
arch/powerpc that is no longer necessary.

cxl has received minimal maintenance for several years, and is not
supported on the Power10 processor. We aren't aware of any users who are
likely to be using recent kernels.

Thanks to Mikey Neuling, Ian Munsie, Daniel Axtens, Frederic Barrat,
Christophe Lombard, Philippe Bergheaud, Vaibhav Jain and Alastair
D'Silva for their work on this driver over the years.

Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Acked-by: Frederic Barrat <fbarrat@linux.ibm.com>
Acked-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20250219070007.177725-2-ajd@linux.ibm.com
2025-03-16 22:04:27 +11:00
Jason Gunthorpe
0e79a47fb1 fwctl: Basic ioctl dispatch for the character device
Each file descriptor gets a chunk of per-FD driver specific context that
allows the driver to attach a device specific struct to. The core code
takes care of the memory lifetime for this structure.

The ioctl dispatch and design is based on what was built for iommufd. The
ioctls have a struct which has a combined in/out behavior with a typical
'zero pad' scheme for future extension and backwards compatibility.

Like iommufd some shared logic does most of the ioctl marshaling and
compatibility work and table dispatches to some function pointers for
each unique ioctl.

This approach has proven to work quite well in the iommufd and rdma
subsystems.

Allocate an ioctl number space for the subsystem.

Link: https://patch.msgid.link/r/2-v5-642aa0c94070+4447f-fwctl_jgg@nvidia.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Shannon Nelson <shannon.nelson@amd.com>
Tested-by: Dave Jiang <dave.jiang@intel.com>
Tested-by: Shannon Nelson <shannon.nelson@amd.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-03-06 15:13:13 -04:00
Eric Biggers
1ebd4a3c09 blk-crypto: add ioctls to create and prepare hardware-wrapped keys
Until this point, the kernel can use hardware-wrapped keys to do
encryption if userspace provides one -- specifically a key in
ephemerally-wrapped form.  However, no generic way has been provided for
userspace to get such a key in the first place.

Getting such a key is a two-step process.  First, the key needs to be
imported from a raw key or generated by the hardware, producing a key in
long-term wrapped form.  This happens once in the whole lifetime of the
key.  Second, the long-term wrapped key needs to be converted into
ephemerally-wrapped form.  This happens each time the key is "unlocked".

In Android, these operations are supported in a generic way through
KeyMint, a userspace abstraction layer.  However, that method is
Android-specific and can't be used on other Linux systems, may rely on
proprietary libraries, and also misleads people into supporting KeyMint
features like rollback resistance that make sense for other KeyMint keys
but don't make sense for hardware-wrapped inline encryption keys.

Therefore, this patch provides a generic kernel interface for these
operations by introducing new block device ioctls:

- BLKCRYPTOIMPORTKEY: convert a raw key to long-term wrapped form.

- BLKCRYPTOGENERATEKEY: have the hardware generate a new key, then
  return it in long-term wrapped form.

- BLKCRYPTOPREPAREKEY: convert a key from long-term wrapped form to
  ephemerally-wrapped form.

These ioctls are implemented using new operations in blk_crypto_ll_ops.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Tested-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> # sm8650
Link: https://lore.kernel.org/r/20250204060041.409950-4-ebiggers@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-02-10 09:54:19 -07:00
Andrew Donnellan
772ba9b5bd scsi: cxlflash: Remove driver
Remove the cxlflash driver for IBM CAPI Flash devices.

The cxlflash driver has received minimal maintenance for some time, and
the CAPI Flash hardware that uses it is no longer commercially available.

Thanks to Uma Krishnan, Matthew Ochs and Manoj Kumar for their work on
this driver over the years.

Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Link: https://lore.kernel.org/r/20250203072801.365551-2-ajd@linux.ibm.com
Reviewed-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2025-02-03 18:04:55 -05:00
Linus Torvalds
2ab002c755 Merge tag 'driver-core-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core and debugfs updates from Greg KH:
 "Here is the big set of driver core and debugfs updates for 6.14-rc1.

  Included in here is a bunch of driver core, PCI, OF, and platform rust
  bindings (all acked by the different subsystem maintainers), hence the
  merge conflict with the rust tree, and some driver core api updates to
  mark things as const, which will also require some fixups due to new
  stuff coming in through other trees in this merge window.

  There are also a bunch of debugfs updates from Al, and there is at
  least one user that does have a regression with these, but Al is
  working on tracking down the fix for it. In my use (and everyone
  else's linux-next use), it does not seem like a big issue at the
  moment.

  Here's a short list of the things in here:

   - driver core rust bindings for PCI, platform, OF, and some i/o
     functions.

     We are almost at the "write a real driver in rust" stage now,
     depending on what you want to do.

   - misc device rust bindings and a sample driver to show how to use
     them

   - debugfs cleanups in the fs as well as the users of the fs api for
     places where drivers got it wrong or were unnecessarily doing
     things in complex ways.

   - driver core const work, making more of the api take const * for
     different parameters to make the rust bindings easier overall.

   - other small fixes and updates

  All of these have been in linux-next with all of the aforementioned
  merge conflicts, and the one debugfs issue, which looks to be resolved
  "soon""

* tag 'driver-core-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (95 commits)
  rust: device: Use as_char_ptr() to avoid explicit cast
  rust: device: Replace CString with CStr in property_present()
  devcoredump: Constify 'struct bin_attribute'
  devcoredump: Define 'struct bin_attribute' through macro
  rust: device: Add property_present()
  saner replacement for debugfs_rename()
  orangefs-debugfs: don't mess with ->d_name
  octeontx2: don't mess with ->d_parent or ->d_parent->d_name
  arm_scmi: don't mess with ->d_parent->d_name
  slub: don't mess with ->d_name
  sof-client-ipc-flood-test: don't mess with ->d_name
  qat: don't mess with ->d_name
  xhci: don't mess with ->d_iname
  mtu3: don't mess wiht ->d_iname
  greybus/camera - stop messing with ->d_iname
  mediatek: stop messing with ->d_iname
  netdevsim: don't embed file_operations into your structs
  b43legacy: make use of debugfs_get_aux()
  b43: stop embedding struct file_operations into their objects
  carl9170: stop embedding file_operations into their objects
  ...
2025-01-28 12:25:12 -08:00
Lukas Bulwahn
5bd97a54da pps: adjust references to actual name of uapi header file
Commit 86b525bed2 ("drivers pps: add PPS generators support") adds a file
entry in MAINTAINERS and a reference in the ioctl-number documentation
referring to the file pps-gen.h, whereas the file added in this commit is
named pps_gen.h.

Adjust the two references to the actual name of the uapi header file.
While at it, put the entry in MAINTAINERS at the right place for
alphabetical ordering.

Fixes: 86b525bed2 ("drivers pps: add PPS generators support")
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@redhat.com>
Link: https://lore.kernel.org/r/20250110105000.56228-1-lukas.bulwahn@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10 16:13:09 +01:00
Rodolfo Giometti
86b525bed2 drivers pps: add PPS generators support
Sometimes one needs to be able not only to catch PPS signals but to
produce them also. For example, running a distributed simulation,
which requires computers' clock to be synchronized very tightly.

This patch adds PPS generators class in order to have a well-defined
interface for these devices.

Signed-off-by: Rodolfo Giometti <giometti@enneenne.com>
Link: https://lore.kernel.org/r/20241108073115.759039-2-giometti@enneenne.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-08 13:18:09 +01:00
Lee Jones
4a9ce18874 Documentation: ioctl-number: Carve out some identifiers for use by sample drivers
32 IDs should be plenty (at yet, not too greedy) since a lot of sample
drivers will use their own subsystem allocations.

Sample drivers predominately reside in <KERNEL_ROOT>/samples, but there
should be no issue with in-place example drivers using them.

Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20241213134715.601415-2-lee@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-16 16:12:44 +01:00
Jan Kara
fb6f20ecb1 reiserfs: The last commit
Deprecation period of reiserfs ends with the end of this year so it is
time to remove it from the kernel.

Acked-by: Darrick J. Wong <djwong@kernel.org>
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
2024-10-21 16:29:38 +02:00
Ming Lei
a4931bb8b0 Documentation: add ublk driver ioctl numbers
ublk driver takes the following ioctl numbers:

	'u'   00-2F  linux/ublk_cmd.h

So document it in ioctl-number.rst

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240823134339.1496916-1-ming.lei@redhat.com
2024-08-26 15:34:14 -06:00
Alyssa Ross
0a8e4dc1d3 Documentation: ioctl: document 0x07 ioctl code
It looks like this was supposed to be documented when VSOCK was
added[1], but it got lost in later submissions.

Link: https://lore.kernel.org/20130109000024.3719.71468.stgit@promb-2n-dhcp175.eng.vmware.com/#Z31Documentation:ioctl:ioctl-number.txt [1]
Fixes: d021c34405 ("VSOCK: Introduce VM Sockets")
Signed-off-by: Alyssa Ross <hi@alyssa.is>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240725171120.12226-2-hi@alyssa.is
2024-07-29 15:25:03 -06:00
Linus Torvalds
acc5965b9f Merge tag 'char-misc-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char / misc and other driver updates from Greg KH:
 "Here is the "big" set of char/misc and other driver subsystem changes
  for 6.11-rc1. Nothing major in here, just loads of new drivers and
  updates. Included in here are:

   - IIO api updates and new drivers added

   - wait_interruptable_timeout() api cleanups for some drivers

   - MODULE_DESCRIPTION() additions for loads of drivers

   - parport out-of-bounds fix

   - interconnect driver updates and additions

   - mhi driver updates and additions

   - w1 driver fixes

   - binder speedups and fixes

   - eeprom driver updates

   - coresight driver updates

   - counter driver update

   - new misc driver additions

   - other minor api updates

  All of these, EXCEPT for the final Kconfig build fix for 32bit
  systems, have been in linux-next for a while with no reported issues.
  The Kconfig fixup went in 29 hours ago, so might have missed the
  latest linux-next, but was acked by everyone involved"

* tag 'char-misc-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (330 commits)
  misc: Kconfig: exclude mrvl-cn10k-dpi compilation for 32-bit systems
  misc: delete Makefile.rej
  binder: fix hang of unregistered readers
  misc: Kconfig: add a new dependency for MARVELL_CN10K_DPI
  virtio: add missing MODULE_DESCRIPTION() macro
  agp: uninorth: add missing MODULE_DESCRIPTION() macro
  spmi: add missing MODULE_DESCRIPTION() macros
  dev/parport: fix the array out-of-bounds risk
  samples: configfs: add missing MODULE_DESCRIPTION() macro
  misc: mrvl-cn10k-dpi: add Octeon CN10K DPI administrative driver
  misc: keba: Fix missing AUXILIARY_BUS dependency
  slimbus: Fix struct and documentation alignment in stream.c
  MAINTAINERS: CC dri-devel list on Qualcomm FastRPC patches
  misc: fastrpc: use coherent pool for untranslated Compute Banks
  misc: fastrpc: support complete DMA pool access to the DSP
  misc: fastrpc: add missing MODULE_DESCRIPTION() macro
  misc: fastrpc: Add missing dev_err newlines
  misc: fastrpc: Use memdup_user()
  nvmem: core: Implement force_ro sysfs attribute
  nvmem: Use sysfs_emit() for type attribute
  ...
2024-07-19 15:55:08 -07:00
Linus Torvalds
cf05e93af4 Merge tag 'docs-6.11' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
 "Nothing hugely exciting happening in the documentation tree this time
  around, mostly more of the usual:

   - More Spanish, Italian, and Chinese translations

   - A new script, scripts/checktransupdate.py, can be used to see which
     commits have touched an (English) document since a given
     translation was last updated.

   - A couple of "best practices" suggestions (on Link: tags and
     off-list discussions) that were not entirely at consensus level,
     but I concluded they were close enough to accept.

   - Some nice cleanups removing documentation for kernel parameters
     that have not been recognized for ... a long time.

  ...along with the usual updates, typo fixes, and such"

* tag 'docs-6.11' of git://git.lwn.net/linux: (57 commits)
  Documentation: Document user_events ioctl code
  docs/pinctrl: fix typo in mapping example
  docs: maintainer: discourage taking conversations off-list
  docs: driver-model: platform: update the definition of platform_driver
  docs/sp_SP: Add translation for scheduler/sched-design-CFS.rst
  writing_musb_glue_layer.rst: Fix broken URL
  zh_CN/admin-guide: one typo fix
  docs/zh_CN/virt: Update the translation of guest-halt-polling.rst
  Documentation: add reference from dynamic debug to loglevel kernel params
  Documentation: best practices for using Link trailers
  Documentation: fix links to mailing list services
  Documentation: exception-tables.rst: Fix the wrong steps referenced
  docs/zh_CN: add process/researcher-guidelines Chinese translation
  Documentation/tools/rv: fix document header
  docs/sp_SP: Add translation of process/maintainer-kvm-x86.rst
  docs/admin-guide/mm: correct typo 'quired' to 'queried'
  Add libps2 to the input section of driver-api
  Docs/mm/index: move allocation profiling document to unsorted documents chapter
  Docs/mm/index: rename 'Legacy Documentation' to 'Unsorted Documentation'
  Docs/mm/index: Remove 'Memory Management Guide' chapter marker
  ...
2024-07-18 15:54:16 -07:00
Beau Belgrave
702418f755 Documentation: Document user_events ioctl code
The user events trace subsystem uses the 0x2A/'*' code for ioctls. These
are published via the uapi/linux/user_events.h header file.

Add a line indicating user events as the owner of the 0x2A/'*' code and
reserve the first 32 sequence numbers.

Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240715181413.1157-1-beaub@linux.microsoft.com
2024-07-16 11:15:02 -06:00
Vamsi Attunuru
5f67eef6df misc: mrvl-cn10k-dpi: add Octeon CN10K DPI administrative driver
Adds a misc driver for Marvell CN10K DPI(DMA Engine) device's physical
function which initializes DPI DMA hardware's global configuration and
enables hardware mailbox channels between physical function (PF) and
it's virtual functions (VF). VF device drivers (User space drivers) use
this hw mailbox to communicate any required device configuration on it's
respective VF device. Accordingly, this DPI PF driver provisions the
VF device resources.

At the hardware level, the DPI physical function (PF) acts as a management
interface to setup the VF device resources, VF devices are only provisioned
to handle or control the actual DMA Engine's data transfer capabilities.

Signed-off-by: Vamsi Attunuru <vattunuru@marvell.com>
Reviewed-by: Srujana Challa <schalla@marvell.com>
Link: https://lore.kernel.org/r/20240706153009.3775333-1-vattunuru@marvell.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-10 14:58:29 +02:00
Steven Rostedt (Google)
4ecaf7e98a tracing: Have memmapped ring buffer use ioctl of "R" range 0x20-2F
To prevent conflicts with other ioctl numbers to allow strace to have an
idea of what is happening, add the range of ioctls for the trace buffer
mapping from _IO("T", 0x1) to the range of "R" 0x20 - 0x2F.

Link: https://lore.kernel.org/linux-trace-kernel/20240630105322.GA17573@altlinux.org/
Link: https://lore.kernel.org/linux-trace-kernel/20240630213626.GA23566@altlinux.org/

Cc: Jonathan Corbet <corbet@lwn.net>
Fixes: cf9f0f7c4c ("tracing: Allow user-space mapping of the ring-buffer")
Link: https://lore.kernel.org/20240702153354.367861db@rorschach.local.home
Reported-by: "Dmitry V. Levin" <ldv@strace.io>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-07-03 16:40:45 -04:00
Elizabeth Figura
b46271ec40 ntsync: Introduce NTSYNC_IOC_CREATE_SEM.
This corresponds to the NT syscall NtCreateSemaphore().

Semaphores are one of three types of object to be implemented in this driver,
the others being mutexes and events.

An NT semaphore contains a 32-bit counter, and is signaled and can be acquired
when the counter is nonzero. The counter has a maximum value which is specified
at creation time. The initial value of the semaphore is also specified at
creation time. There are no restrictions on the maximum and initial value.

Each object is exposed as an file, to which any number of fds may be opened.
When all fds are closed, the object is deleted.

Objects hold a pointer to the ntsync_device that created them. The device's
reference count is driven by struct file.

Signed-off-by: Elizabeth Figura <zfigura@codeweavers.com>
Link: https://lore.kernel.org/r/20240329000621.148791-3-zfigura@codeweavers.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-11 15:34:38 +02:00
Linus Torvalds
9187210eee Merge tag 'net-next-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from Jakub Kicinski:
 "Core & protocols:

   - Large effort by Eric to lower rtnl_lock pressure and remove locks:

      - Make commonly used parts of rtnetlink (address, route dumps
        etc) lockless, protected by RCU instead of rtnl_lock.

      - Add a netns exit callback which already holds rtnl_lock,
        allowing netns exit to take rtnl_lock once in the core instead
        of once for each driver / callback.

      - Remove locks / serialization in the socket diag interface.

      - Remove 6 calls to synchronize_rcu() while holding rtnl_lock.

      - Remove the dev_base_lock, depend on RCU where necessary.

   - Support busy polling on a per-epoll context basis. Poll length and
     budget parameters can be set independently of system defaults.

   - Introduce struct net_hotdata, to make sure read-mostly global
     config variables fit in as few cache lines as possible.

   - Add optional per-nexthop statistics to ease monitoring / debug of
     ECMP imbalance problems.

   - Support TCP_NOTSENT_LOWAT in MPTCP.

   - Ensure that IPv6 temporary addresses' preferred lifetimes are long
     enough, compared to other configured lifetimes, and at least 2 sec.

   - Support forwarding of ICMP Error messages in IPSec, per RFC 4301.

   - Add support for the independent control state machine for bonding
     per IEEE 802.1AX-2008 5.4.15 in addition to the existing coupled
     control state machine.

   - Add "network ID" to MCTP socket APIs to support hosts with multiple
     disjoint MCTP networks.

   - Re-use the mono_delivery_time skbuff bit for packets which user
     space wants to be sent at a specified time. Maintain the timing
     information while traversing veth links, bridge etc.

   - Take advantage of MSG_SPLICE_PAGES for RxRPC DATA and ACK packets.

   - Simplify many places iterating over netdevs by using an xarray
     instead of a hash table walk (hash table remains in place, for use
     on fastpaths).

   - Speed up scanning for expired routes by keeping a dedicated list.

   - Speed up "generic" XDP by trying harder to avoid large allocations.

   - Support attaching arbitrary metadata to netconsole messages.

  Things we sprinkled into general kernel code:

   - Enforce VM_IOREMAP flag and range in ioremap_page_range and
     introduce VM_SPARSE kind and vm_area_[un]map_pages (used by
     bpf_arena).

   - Rework selftest harness to enable the use of the full range of ksft
     exit code (pass, fail, skip, xfail, xpass).

  Netfilter:

   - Allow userspace to define a table that is exclusively owned by a
     daemon (via netlink socket aliveness) without auto-removing this
     table when the userspace program exits. Such table gets marked as
     orphaned and a restarting management daemon can re-attach/regain
     ownership.

   - Speed up element insertions to nftables' concatenated-ranges set
     type. Compact a few related data structures.

  BPF:

   - Add BPF token support for delegating a subset of BPF subsystem
     functionality from privileged system-wide daemons such as systemd
     through special mount options for userns-bound BPF fs to a trusted
     & unprivileged application.

   - Introduce bpf_arena which is sparse shared memory region between
     BPF program and user space where structures inside the arena can
     have pointers to other areas of the arena, and pointers work
     seamlessly for both user-space programs and BPF programs.

   - Introduce may_goto instruction that is a contract between the
     verifier and the program. The verifier allows the program to loop
     assuming it's behaving well, but reserves the right to terminate
     it.

   - Extend the BPF verifier to enable static subprog calls in spin lock
     critical sections.

   - Support registration of struct_ops types from modules which helps
     projects like fuse-bpf that seeks to implement a new struct_ops
     type.

   - Add support for retrieval of cookies for perf/kprobe multi links.

   - Support arbitrary TCP SYN cookie generation / validation in the TC
     layer with BPF to allow creating SYN flood handling in BPF
     firewalls.

   - Add code generation to inline the bpf_kptr_xchg() helper which
     improves performance when stashing/popping the allocated BPF
     objects.

  Wireless:

   - Add SPP (signaling and payload protected) AMSDU support.

   - Support wider bandwidth OFDMA, as required for EHT operation.

  Driver API:

   - Major overhaul of the Energy Efficient Ethernet internals to
     support new link modes (2.5GE, 5GE), share more code between
     drivers (especially those using phylib), and encourage more
     uniform behavior. Convert and clean up drivers.

   - Define an API for querying per netdev queue statistics from
     drivers.

   - IPSec: account in global stats for fully offloaded sessions.

   - Create a concept of Ethernet PHY Packages at the Device Tree level,
     to allow parameterizing the existing PHY package code.

   - Enable Rx hashing (RSS) on GTP protocol fields.

  Misc:

   - Improvements and refactoring all over networking selftests.

   - Create uniform module aliases for TC classifiers, actions, and
     packet schedulers to simplify creating modprobe policies.

   - Address all missing MODULE_DESCRIPTION() warnings in networking.

   - Extend the Netlink descriptions in YAML to cover message
     encapsulation or "Netlink polymorphism", where interpretation of
     nested attributes depends on link type, classifier type or some
     other "class type".

  Drivers:

   - Ethernet high-speed NICs:
      - Add a new driver for Marvell's Octeon PCI Endpoint NIC VF.
      - Intel (100G, ice, idpf):
         - support E825-C devices
      - nVidia/Mellanox:
         - support devices with one port and multiple PCIe links
      - Broadcom (bnxt):
         - support n-tuple filters
         - support configuring the RSS key
      - Wangxun (ngbe/txgbe):
         - implement irq_domain for TXGBE's sub-interrupts
      - Pensando/AMD:
         - support XDP
         - optimize queue submission and wakeup handling (+17% bps)
         - optimize struct layout, saving 28% of memory on queues

   - Ethernet NICs embedded and virtual:
      - Google cloud vNIC:
         - refactor driver to perform memory allocations for new queue
           config before stopping and freeing the old queue memory
      - Synopsys (stmmac):
         - obey queueMaxSDU and implement counters required by 802.1Qbv
      - Renesas (ravb):
         - support packet checksum offload
         - suspend to RAM and runtime PM support

   - Ethernet switches:
      - nVidia/Mellanox:
         - support for nexthop group statistics
      - Microchip:
         - ksz8: implement PHY loopback
         - add support for KSZ8567, a 7-port 10/100Mbps switch

   - PTP:
      - New driver for RENESAS FemtoClock3 Wireless clock generator.
      - Support OCP PTP cards designed and built by Adva.

   - CAN:
      - Support recvmsg() flags for own, local and remote traffic on CAN
        BCM sockets.
      - Support for esd GmbH PCIe/402 CAN device family.
      - m_can:
         - Rx/Tx submission coalescing
         - wake on frame Rx

   - WiFi:
      - Intel (iwlwifi):
         - enable signaling and payload protected A-MSDUs
         - support wider-bandwidth OFDMA
         - support for new devices
         - bump FW API to 89 for AX devices; 90 for BZ/SC devices
      - MediaTek (mt76):
         - mt7915: newer ADIE version support
         - mt7925: radio temperature sensor support
      - Qualcomm (ath11k):
         - support 6 GHz station power modes: Low Power Indoor (LPI),
           Standard Power) SP and Very Low Power (VLP)
         - QCA6390 & WCN6855: support 2 concurrent station interfaces
         - QCA2066 support
      - Qualcomm (ath12k):
         - refactoring in preparation for Multi-Link Operation (MLO)
           support
         - 1024 Block Ack window size support
         - firmware-2.bin support
         - support having multiple identical PCI devices (firmware needs
           to have ATH12K_FW_FEATURE_MULTI_QRTR_ID)
         - QCN9274: support split-PHY devices
         - WCN7850: enable Power Save Mode in station mode
         - WCN7850: P2P support
      - RealTek:
         - rtw88: support for more rtw8811cu and rtw8821cu devices
         - rtw89: support SCAN_RANDOM_SN and SET_SCAN_DWELL
         - rtlwifi: speed up USB firmware initialization
         - rtwl8xxxu:
             - RTL8188F: concurrent interface support
             - Channel Switch Announcement (CSA) support in AP mode
      - Broadcom (brcmfmac):
         - per-vendor feature support
         - per-vendor SAE password setup
         - DMI nvram filename quirk for ACEPC W5 Pro"

* tag 'net-next-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2255 commits)
  nexthop: Fix splat with CONFIG_DEBUG_PREEMPT=y
  nexthop: Fix out-of-bounds access during attribute validation
  nexthop: Only parse NHA_OP_FLAGS for dump messages that require it
  nexthop: Only parse NHA_OP_FLAGS for get messages that require it
  bpf: move sleepable flag from bpf_prog_aux to bpf_prog
  bpf: hardcode BPF_PROG_PACK_SIZE to 2MB * num_possible_nodes()
  selftests/bpf: Add kprobe multi triggering benchmarks
  ptp: Move from simple ida to xarray
  vxlan: Remove generic .ndo_get_stats64
  vxlan: Do not alloc tstats manually
  devlink: Add comments to use netlink gen tool
  nfp: flower: handle acti_netdevs allocation failure
  net/packet: Add getsockopt support for PACKET_COPY_THRESH
  net/netlink: Add getsockopt support for NETLINK_LISTEN_ALL_NSID
  selftests/bpf: Add bpf_arena_htab test.
  selftests/bpf: Add bpf_arena_list test.
  selftests/bpf: Add unit tests for bpf_arena_alloc/free_pages
  bpf: Add helper macro bpf_addr_space_cast()
  libbpf: Recognize __arena global variables.
  bpftool: Recognize arena map type
  ...
2024-03-12 17:44:08 -07:00
Joe Damato
18e2bf0edf eventpoll: Add epoll ioctl for epoll_params
Add an ioctl for getting and setting epoll_params. User programs can use
this ioctl to get and set the busy poll usec time, packet budget, and
prefer busy poll params for a specific epoll context.

Parameters are limited:
  - busy_poll_usecs is limited to <= s32_max
  - busy_poll_budget is limited to <= NAPI_POLL_WEIGHT by unprivileged
    users (!capable(CAP_NET_ADMIN))
  - prefer_busy_poll must be 0 or 1
  - __pad must be 0

Signed-off-by: Joe Damato <jdamato@fastly.com>
Acked-by: Stanislav Fomichev <sdf@google.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-14 11:01:01 +00:00
Kent Overstreet
41bcbe59c3 fs: FS_IOC_GETUUID
Add a new generic ioctls for querying the filesystem UUID.

These are lifted versions of the ext4 ioctls, with one change: we're not
using a flexible array member, because UUIDs will never be more than 16
bytes.

This patch adds a generic implementation of FS_IOC_GETFSUUID, which
reads from super_block->s_uuid. We're not lifting SETFSUUID from ext4 -
that can be done on offline filesystems by the people who need it,
trying to do it online is just asking for too much trouble.

Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Link: https://lore.kernel.org/r/20240207025624.1019754-4-kent.overstreet@linux.dev
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-02-08 21:20:11 +01:00
Thomas Zimmermann
689237ab37 fbdev/intelfb: Remove driver
From looking at the PCI IDs, every device supported by intelfb is
also supported by i915. Anyone still using intelfb should please
move on to i915, which does everything intelfb does but better.

Removing intelfb is motivated by the driver's excessive use of the
global screen_info state. The state belongs to architecture and
firmware code; device drivers should not attempt to access it. But
fixing intelfb would require a significant change in the driver's
probing logic. As intelfb has been obsolete for nearly 2 decades,
it is probably not worth the effort. Let's just remove it. Also
remove the related documentation.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Maik Broemme <mbroemme@libmpq.org>
Signed-off-by: Helge Deller <deller@gmx.de>
2024-01-12 12:38:37 +01:00
Nathan Lynch
905b9e4878 powerpc/pseries/papr-sysparm: Expose character device to user space
Until now the papr_sysparm APIs have been kernel-internal. But user
space needs access to PAPR system parameters too. The only method
available to user space today to get or set system parameters is using
sys_rtas() and /dev/mem to pass RTAS-addressable buffers between user
space and firmware. This is incompatible with lockdown and should be
deprecated.

So provide an alternative ABI to user space in the form of a
/dev/papr-sysparm character device with just two ioctl commands (get
and set). The data payloads involved are small enough to fit in the
ioctl argument buffer, making the code relatively simple.

Exposing the system parameters through sysfs has been considered but
it would be too awkward:

* The kernel currently does not have to contain an exhaustive list of
  defined system parameters. This is a convenient property to maintain
  because we don't have to update the kernel whenever a new parameter
  is added to PAPR. Exporting a named attribute in sysfs for each
  parameter would negate this.

* Some system parameters are text-based and some are not.

* Retrieval of at least one system parameter requires input data,
  which a simple read-oriented interface can't support.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231212-papr-sys_rtas-vs-lockdown-v6-11-e9eafd0c8c6c@linux.ibm.com
2023-12-13 21:38:21 +11:00
Nathan Lynch
514f6ff436 powerpc/pseries: Add papr-vpd character driver for VPD retrieval
PowerVM LPARs may retrieve Vital Product Data (VPD) for system
components using the ibm,get-vpd RTAS function.

We can expose this to user space with a /dev/papr-vpd character
device, where the programming model is:

  struct papr_location_code plc = { .str = "", }; /* obtain all VPD */
  int devfd = open("/dev/papr-vpd", O_RDONLY);
  int vpdfd = ioctl(devfd, PAPR_VPD_CREATE_HANDLE, &plc);
  size_t size = lseek(vpdfd, 0, SEEK_END);
  char *buf = malloc(size);
  pread(devfd, buf, size, 0);

When a file descriptor is obtained from ioctl(PAPR_VPD_CREATE_HANDLE),
the file contains the result of a complete ibm,get-vpd sequence. The
file contents are immutable from the POV of user space. To get a new
view of the VPD, the client must create a new handle.

This design choice insulates user space from most of the complexities
that ibm,get-vpd brings:

* ibm,get-vpd must be called more than once to obtain complete
  results.

* Only one ibm,get-vpd call sequence should be in progress at a time;
  interleaved sequences will disrupt each other. Callers must have a
  protocol for serializing their use of the function.

* A call sequence in progress may receive a "VPD changed, try again"
  status, requiring the client to abandon the sequence and start
  over.

The memory required for the VPD buffers seems acceptable, around 20KB
for all VPD on one of my systems. And the value of the
/rtas/ibm,vpd-size DT property (the estimated maximum size of VPD) is
consistently 300KB across various systems I've checked.

I've implemented support for this new ABI in the rtas_get_vpd()
function in librtas, which the vpdupdate command currently uses to
populate its VPD database. I've verified that an unmodified vpdupdate
binary generates an identical database when using a librtas.so that
prefers the new ABI.

Along with the papr-vpd.h header exposed to user space, this
introduces a common papr-miscdev.h uapi header to share a base ioctl
ID with similar drivers to come.

Tested-by: Michal Suchánek <msuchanek@suse.de>
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231212-papr-sys_rtas-vs-lockdown-v6-9-e9eafd0c8c6c@linux.ibm.com
2023-12-13 21:38:21 +11:00
Julien Panis
dce5488896 Documentation: Add TI TPS6594 PFSM
This patch adds documentation for the TPS6594 PFSM driver.

The PFSM controls the operational states of the TPS6594 PMIC.
Depending on the operational mode, some power domain networks
remain energized while others can be off.

Signed-off-by: Julien Panis <jpanis@baylibre.com>
Message-ID: <20230511095126.105104-6-jpanis@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-15 13:41:53 +02:00
Steve French
bf8a352d49 cifs: correct references in Documentation to old fs/cifs path
The fs/cifs directory has moved to fs/smb/client, correct mentions
of this in Documentation and comments.

Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-05-24 16:29:21 -05:00