Linux kernel
============
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be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
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Standards such as the MIPI DisCo for SoundWire 1.0 specification
assume the _ADR field is 64 bits.
_ADR is defined as an "Integer" represented as 64 bits since ACPI 2.0
released in 2002. The low levels already use _ADR as 64 bits, e.g. in
struct acpi_device_info.
This patch bumps the representation used for sysfs to 64 bits. To
avoid any compatibility/ABI issues, the printf format is only extended
to 16 characters when the actual _ADR value exceeds the 32 bit
maximum.
Example with a SoundWire device, the results show the complete
vendorID and linkID which were omitted before:
Before:
$ more /sys/bus/acpi/devices/device\:38/adr
0x5d070000
After:
$ more /sys/bus/acpi/devices/device\:38/adr
0x000010025d070000
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
[ rjw: Replace 0xFFFFFFFF with U32_MAX, clean up subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull ACPI updates from Rafael Wysocki:
"These rearrange the ACPI documentation by converting it to the .rst
format and splitting it into clear categories (admin guide, driver
API, firmware guide), switch over multiple users of a problematic
library function to a new better one, update the ACPICA code in the
kernel to a new upstream release, fix a few issues, improve power
device management diagnostics and do some cleanups.
Specifics:
- Convert the ACPI documentation in the kernel source tree to the
.rst format and split it into the admin guide, driver API and
firmware guide parts (Changbin Du).
- Add a PRP0001 usage example to the ACPI documentation (Thomas
Preston).
- Switch over the users of the acpi_dev_get_first_match_name()
library function which turned out to be problematic to a new,
better one called acpi_dev_get_first_match_dev() (Andy Shevchenko,
YueHaibing).
- Update the ACPICA code in the kernel to upstream release 20190405
including:
* Null pointer dereference check in acpi_ns_delete_node() (Erik
Schmauss).
* Multiple macro and function name changes (Bob Moore).
* Predefined operation region name fix (Erik Schmauss).
- Fix hibernation issue on systems using the Baytrail and Cherrytrail
Intel SoCs introduced during the 4.20 development cycle (Hans de
Goede).
- Add Sony VPCEH3U1E to the backlight quirk list (Zhang Rui).
- Fix button handling during system resume (Zhang Rui).
- Add a device PM diagnostic message (Rafael Wysocki).
- Clean up the code, comments and white space in multiple places
(Bjorn Helgaas, Gustavo Silva, Kefeng Wang)"
* tag 'acpi-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (53 commits)
Documentation: ACPI: move video_extension.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move ssdt-overlays.txt to admin-guide/acpi and convert to reST
Documentation: ACPI: move lpit.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move cppc_sysfs.txt to admin-guide/acpi and convert to reST
Documentation: ACPI: move apei/einj.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move apei/output_format.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move aml-debugger.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move method-tracing.txt to firmware-guide/acpi and convert to rsST
Documentation: ACPI: move debug.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move dsd/data-node-references.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move dsd/graph.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move acpi-lid.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move i2c-muxes.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move dsdt-override.txt to admin-guide/acpi and convert to reST
Documentation: ACPI: move initrd_table_override.txt to admin-guide/acpi and convert to reST
Documentation: ACPI: move method-customizing.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move gpio-properties.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move DSD-properties-rules.txt to firmware-guide/acpi and covert to reST
Documentation: ACPI: move scan_handlers.txt to driver-api/acpi and convert to reST
Documentation: ACPI: move linuxized-acpica.txt to driver-api/acpi and convert to reST
...
Pull arm64 updates from Will Deacon:
"Mostly just incremental improvements here:
- Introduce AT_HWCAP2 for advertising CPU features to userspace
- Expose SVE2 availability to userspace
- Support for "data cache clean to point of deep persistence" (DC PODP)
- Honour "mitigations=off" on the cmdline and advertise status via
sysfs
- CPU timer erratum workaround (Neoverse-N1 #1188873)
- Introduce perf PMU driver for the SMMUv3 performance counters
- Add config option to disable the kuser helpers page for AArch32 tasks
- Futex modifications to ensure liveness under contention
- Rework debug exception handling to seperate kernel and user
handlers
- Non-critical fixes and cleanup"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (92 commits)
Documentation: Add ARM64 to kernel-parameters.rst
arm64/speculation: Support 'mitigations=' cmdline option
arm64: ssbs: Don't treat CPUs with SSBS as unaffected by SSB
arm64: enable generic CPU vulnerabilites support
arm64: add sysfs vulnerability show for speculative store bypass
arm64: Fix size of __early_cpu_boot_status
clocksource/arm_arch_timer: Use arch_timer_read_counter to access stable counters
clocksource/arm_arch_timer: Remove use of workaround static key
clocksource/arm_arch_timer: Drop use of static key in arch_timer_reg_read_stable
clocksource/arm_arch_timer: Direcly assign set_next_event workaround
arm64: Use arch_timer_read_counter instead of arch_counter_get_cntvct
watchdog/sbsa: Use arch_timer_read_counter instead of arch_counter_get_cntvct
ARM: vdso: Remove dependency with the arch_timer driver internals
arm64: Apply ARM64_ERRATUM_1188873 to Neoverse-N1
arm64: Add part number for Neoverse N1
arm64: Make ARM64_ERRATUM_1188873 depend on COMPAT
arm64: Restrict ARM64_ERRATUM_1188873 mitigation to AArch32
arm64: mm: Remove pte_unmap_nested()
arm64: Fix compiler warning from pte_unmap() with -Wunused-but-set-variable
arm64: compat: Reduce address limit for 64K pages
...
* acpi-doc: (25 commits)
Documentation: ACPI: move video_extension.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move ssdt-overlays.txt to admin-guide/acpi and convert to reST
Documentation: ACPI: move lpit.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move cppc_sysfs.txt to admin-guide/acpi and convert to reST
Documentation: ACPI: move apei/einj.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move apei/output_format.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move aml-debugger.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move method-tracing.txt to firmware-guide/acpi and convert to rsST
Documentation: ACPI: move debug.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move dsd/data-node-references.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move dsd/graph.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move acpi-lid.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move i2c-muxes.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move dsdt-override.txt to admin-guide/acpi and convert to reST
Documentation: ACPI: move initrd_table_override.txt to admin-guide/acpi and convert to reST
Documentation: ACPI: move method-customizing.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move gpio-properties.txt to firmware-guide/acpi and convert to reST
Documentation: ACPI: move DSD-properties-rules.txt to firmware-guide/acpi and covert to reST
Documentation: ACPI: move scan_handlers.txt to driver-api/acpi and convert to reST
Documentation: ACPI: move linuxized-acpica.txt to driver-api/acpi and convert to reST
...
Pull mmiowb removal from Will Deacon:
"Remove Mysterious Macro Intended to Obscure Weird Behaviours (mmiowb())
Remove mmiowb() from the kernel memory barrier API and instead, for
architectures that need it, hide the barrier inside spin_unlock() when
MMIO has been performed inside the critical section.
The only relatively recent changes have been addressing review
comments on the documentation, which is in a much better shape thanks
to the efforts of Ben and Ingo.
I was initially planning to split this into two pull requests so that
you could run the coccinelle script yourself, however it's been plain
sailing in linux-next so I've just included the whole lot here to keep
things simple"
* tag 'arm64-mmiowb' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (23 commits)
docs/memory-barriers.txt: Update I/O section to be clearer about CPU vs thread
docs/memory-barriers.txt: Fix style, spacing and grammar in I/O section
arch: Remove dummy mmiowb() definitions from arch code
net/ethernet/silan/sc92031: Remove stale comment about mmiowb()
i40iw: Redefine i40iw_mmiowb() to do nothing
scsi/qla1280: Remove stale comment about mmiowb()
drivers: Remove explicit invocations of mmiowb()
drivers: Remove useless trailing comments from mmiowb() invocations
Documentation: Kill all references to mmiowb()
riscv/mmiowb: Hook up mmwiob() implementation to asm-generic code
powerpc/mmiowb: Hook up mmwiob() implementation to asm-generic code
ia64/mmiowb: Add unconditional mmiowb() to arch_spin_unlock()
mips/mmiowb: Add unconditional mmiowb() to arch_spin_unlock()
sh/mmiowb: Add unconditional mmiowb() to arch_spin_unlock()
m68k/io: Remove useless definition of mmiowb()
nds32/io: Remove useless definition of mmiowb()
x86/io: Remove useless definition of mmiowb()
arm64/io: Remove useless definition of mmiowb()
ARM/io: Remove useless definition of mmiowb()
mmiowb: Hook up mmiowb helpers to spinlocks and generic I/O accessors
...
* acpi-utils:
gpio: merrifield: Fix build err without CONFIG_ACPI
ACPI / utils: Remove deprecated function since no user left
ASoC: Intel: cht_bsw_rt5672: Convert to use acpi_dev_get_first_match_dev()
ASoC: Intel: cht_bsw_rt5645: Convert to use acpi_dev_get_first_match_dev()
ASoC: Intel: bytcr_rt5651: Convert to use acpi_dev_get_first_match_dev()
ASoC: Intel: bytcr_rt5640: Convert to use acpi_dev_get_first_match_dev()
ASoC: Intel: bytcht_es8316: Convert to use acpi_dev_get_first_match_dev()
ASoC: Intel: bytcht_da7213: Convert to use acpi_dev_get_first_match_dev()
gpio: merrifield: Convert to use acpi_dev_get_first_match_dev()
extcon: axp288: Convert to use acpi_dev_get_first_match_dev()
ACPI / utils: Introduce acpi_dev_get_first_match_dev() helper
* acpi-video:
ACPI: video: Use vendor backlight on Sony VPCEH3U1E
* acpi-soc:
ACPI / LPSS: Use acpi_lpss_* instead of acpi_subsys_* functions for hibernate
* acpi-button:
ACPI: button: reinitialize button state upon resume
This converts the plain text documentation to reStructuredText format
and adds it to Sphinx TOC tree.
No essential content change.
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull s390 updates from Martin Schwidefsky:
- Support for kernel address space layout randomization
- Add support for kernel image signature verification
- Convert s390 to the generic get_user_pages_fast code
- Convert s390 to the stack unwind API analog to x86
- Add support for CPU directed interrupts for PCI devices
- Provide support for MIO instructions to the PCI base layer, this will
allow the use of direct PCI mappings in user space code
- Add the basic KVM guest ultravisor interface for protected VMs
- Add AT_HWCAP bits for several new hardware capabilities
- Update the CPU measurement facility counter definitions to SVN 6
- Arnds cleanup patches for his quest to get LLVM compiles working
- A vfio-ccw update with bug fixes and support for halt and clear
- Improvements for the hardware TRNG code
- Another round of cleanup for the QDIO layer
- Numerous cleanups and bug fixes
* tag 's390-5.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (98 commits)
s390/vdso: drop unnecessary cc-ldoption
s390: fix clang -Wpointer-sign warnigns in boot code
s390: drop CONFIG_VIRT_TO_BUS
s390: boot, purgatory: pass $(CLANG_FLAGS) where needed
s390: only build for new CPUs with clang
s390: simplify disabled_wait
s390/ftrace: use HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
s390/unwind: introduce stack unwind API
s390/opcodes: add missing instructions to the disassembler
s390/bug: add entry size to the __bug_table section
s390: use proper expoline sections for .dma code
s390/nospec: rename assembler generated expoline thunks
s390: add missing ENDPROC statements to assembler functions
locking/lockdep: check for freed initmem in static_obj()
s390/kernel: add support for kernel address space layout randomization (KASLR)
s390/kernel: introduce .dma sections
s390/sclp: do not use static sccbs
s390/kprobes: use static buffer for insn_page
s390/kernel: convert SYSCALL and PGM_CHECK handlers to .quad
s390/kernel: build a relocatable kernel
...
The revised I/O ordering section of memory-barriers.txt introduced in
4614bbdee357 ("docs/memory-barriers.txt: Rewrite "KERNEL I/O BARRIER
EFFECTS" section") loosely refers to "the CPU", whereas the ordering
guarantees generally apply within a thread of execution that can migrate
between cores, with the scheduler providing the relevant barrier
semantics.
Reword the section to refer to "CPU thread" and call out ordering of
MMIO writes separately from ordering of writes to memory. Ben also
spotted that the string accessors are native-endian, so fix that up too.
Link: https://lkml.kernel.org/r/080d1ec73e3e29d6ffeeeb50b39b613da28afb37.camel@kernel.crashing.org
Fixes: 4614bbdee357 ("docs/memory-barriers.txt: Rewrite "KERNEL I/O BARRIER EFFECTS" section")
Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Conflicts:
arch/arm64/Kconfig
arch/arm64/include/asm/arch_timer.h
Like arm-cci, arm-ccn has the same issue of disabling preemption around
operations which can take mutexes. Again, remove the definite bug by
simply not trying to fight the theoretical races. And since we are
touching the hotplug handling code, take the opportunity to streamline
it, as there's really no need to store a full-sized cpumask to keep
track of a single CPU ID.
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
* acpi-scan:
ACPI / scan: Add labels for PNP button devices
ACPI / scan: Simplify acpi_bus_extract_wakeup_device_power_package()
* acpi-tables:
ACPI / tables: Clean up whitespace
* acpi-misc:
ACPI / DPTF: Use dev_get_drvdata()
ACPI: event: replace strcpy() by strscpy()
ACPI: Fix comment typos
* acpi-pm:
ACPI: PM: Print debug messages when enabling GPEs for wakeup