linux-toradex.git/include/linux/timekeeping.h, branch v5.1-rc1

timekeeping: remove obsolete time accessors

2018-12-18T15:13:05+00:00

There are no more remaining users of these deprecated wrappers, so
let's remove them before new users have a chance to make it in.

See Documentation/core-api/timekeeping.rst for replacements when
porting old drivers that contain calls to this function.

Signed-off-by: Arnd Bergmann 
Acked-by: John Stultz

Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-10-25T18:14:36+00:00

Pull timekeeping updates from Thomas Gleixner:
 "The timers and timekeeping departement provides:

   - Another large y2038 update with further preparations for providing
     the y2038 safe timespecs closer to the syscalls.

   - An overhaul of the SHCMT clocksource driver

   - SPDX license identifier updates

   - Small cleanups and fixes all over the place"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits)
  tick/sched : Remove redundant cpu_online() check
  clocksource/drivers/dw_apb: Add reset control
  clocksource: Remove obsolete CLOCKSOURCE_OF_DECLARE
  clocksource/drivers: Unify the names to timer-* format
  clocksource/drivers/sh_cmt: Add R-Car gen3 support
  dt-bindings: timer: renesas: cmt: document R-Car gen3 support
  clocksource/drivers/sh_cmt: Properly line-wrap sh_cmt_of_table[] initializer
  clocksource/drivers/sh_cmt: Fix clocksource width for 32-bit machines
  clocksource/drivers/sh_cmt: Fixup for 64-bit machines
  clocksource/drivers/sh_tmu: Convert to SPDX identifiers
  clocksource/drivers/sh_mtu2: Convert to SPDX identifiers
  clocksource/drivers/sh_cmt: Convert to SPDX identifiers
  clocksource/drivers/renesas-ostm: Convert to SPDX identifiers
  clocksource: Convert to using %pOFn instead of device_node.name
  tick/broadcast: Remove redundant check
  RISC-V: Request newstat syscalls
  y2038: signal: Change rt_sigtimedwait to use __kernel_timespec
  y2038: socket: Change recvmmsg to use __kernel_timespec
  y2038: sched: Change sched_rr_get_interval to use __kernel_timespec
  y2038: utimes: Rework #ifdef guards for compat syscalls
  ...

timekeeping: Fix declaration of read_persistent_wall_and_boot_offset()

2018-09-03T11:26:44+00:00

It is read_persistent_wall_and_boot_offset() and not
read_persistent_clock_and_boot_offset()

Fixes: 3eca993740b8eb40f51 ("timekeeping: Replace read_boot_clock64() with read_persistent_wall_and_boot_offset()")
Signed-off-by: Christian Borntraeger 
Signed-off-by: Thomas Gleixner 
Cc: Pavel Tatashin 
Link: https://lkml.kernel.org/r/20180903081533.34366-1-borntraeger@de.ibm.com

y2038: remove unused time interfaces

2018-08-27T10:59:56+00:00

After many small patches, at least some of the deprecated interfaces
have no remaining users any more and can be removed:

  current_kernel_time
  do_settimeofday
  get_monotonic_boottime
  get_monotonic_boottime64
  get_monotonic_coarse
  get_monotonic_coarse64
  getrawmonotonic64
  ktime_get_real_ts
  timekeeping_clocktai
  timespec_trunc
  timespec_valid_strict
  time_to_tm

For many of the remaining time functions, we are missing one or
two patches that failed to make it into 4.19, they will be removed
in the following merge window.

The replacement functions for the removed interfaces are documented in
Documentation/core-api/timekeeping.rst.

Signed-off-by: Arnd Bergmann

Merge tag 'docs-4.19' of git://git.lwn.net/linux

2018-08-14T21:29:31+00:00

Pull documentation update from Jonathan Corbet:
 "This was a moderately busy cycle for docs, with the usual collection
  of small fixes and updates.

  We also have new ktime_get_*() docs from Arnd, some kernel-doc fixes,
  a new set of Italian translations (non so se vale la pena, ma non fa
  male - speriamo bene), and some extensive early memory-management
  documentation improvements from Mike Rapoport"

* tag 'docs-4.19' of git://git.lwn.net/linux: (52 commits)
  Documentation: corrections to console/console.txt
  Documentation: add ioctl number entry for v4l2-subdev.h
  Remove gendered language from management style documentation
  scripts/kernel-doc: Escape all literal braces in regexes
  docs/mm: add description of boot time memory management
  docs/mm: memblock: add overview documentation
  docs/mm: memblock: add kernel-doc description for memblock types
  docs/mm: memblock: add kernel-doc comments for memblock_add[_node]
  docs/mm: memblock: update kernel-doc comments
  mm/memblock: add a name for memblock flags enumeration
  docs/mm: bootmem: add overview documentation
  docs/mm: bootmem: add kernel-doc description of 'struct bootmem_data'
  docs/mm: bootmem: fix kernel-doc warnings
  docs/mm: nobootmem: fixup kernel-doc comments
  mm/bootmem: drop duplicated kernel-doc comments
  Documentation: vm.txt: Adding 'nr_hugepages_mempolicy' parameter description.
  doc:it_IT: translation for kernel-hacking
  docs: Fix the reference labels in Locking.rst
  doc: tracing: Fix a typo of trace_stat
  mm: Introduce new type vm_fault_t
  ...

Merge branch 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-08-14T01:28:19+00:00

Pull x86 timer updates from Thomas Gleixner:
 "Early TSC based time stamping to allow better boot time analysis.

  This comes with a general cleanup of the TSC calibration code which
  grew warts and duct taping over the years and removes 250 lines of
  code. Initiated and mostly implemented by Pavel with help from various
  folks"

* 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits)
  x86/kvmclock: Mark kvm_get_preset_lpj() as __init
  x86/tsc: Consolidate init code
  sched/clock: Disable interrupts when calling generic_sched_clock_init()
  timekeeping: Prevent false warning when persistent clock is not available
  sched/clock: Close a hole in sched_clock_init()
  x86/tsc: Make use of tsc_calibrate_cpu_early()
  x86/tsc: Split native_calibrate_cpu() into early and late parts
  sched/clock: Use static key for sched_clock_running
  sched/clock: Enable sched clock early
  sched/clock: Move sched clock initialization and merge with generic clock
  x86/tsc: Use TSC as sched clock early
  x86/tsc: Initialize cyc2ns when tsc frequency is determined
  x86/tsc: Calibrate tsc only once
  ARM/time: Remove read_boot_clock64()
  s390/time: Remove read_boot_clock64()
  timekeeping: Default boot time offset to local_clock()
  timekeeping: Replace read_boot_clock64() with read_persistent_wall_and_boot_offset()
  s390/time: Add read_persistent_wall_and_boot_offset()
  x86/xen/time: Output xen sched_clock time from 0
  x86/xen/time: Initialize pv xen time in init_hypervisor_platform()
  ...

Documentation: document ktime_get_*() APIs

2018-07-23T15:16:56+00:00

As Dave Chinner points out, we don't have a proper documentation for the
ktime_get() family of interfaces, making it rather unclear which of the
over 30 (!) interfaces one should actually use in a driver or elsewhere
in the kernel.

I wrote up an explanation from how I personally see the interfaces,
documenting what each of the functions do and hopefully making it a bit
clearer which should be used where.

This is the first time I tried writing .rst format documentation, so
in addition to any mistakes in the content, I probably also introduce
nonstandard formatting ;-)

I first tried to add an extra section to
Documentation/timers/timekeeping.txt, but this is currently not included
in the generated API, and it seems useful to have the API docs as part
of what gets generated in
https://www.kernel.org/doc/html/latest/core-api/index.html#core-utilities
instead, so I started a new file there.

I also considered adding the documentation inline in the
include/linux/timekeeping.h header, but couldn't figure out how to do
that in a way that would result both in helpful inline comments as
well as readable html output, so I settled for the latter, with
a small note pointing to it from the header.

Cc: Dave Chinner 
Cc: John Stultz 
Cc: Thomas Gleixner 
Cc: Stephen Boyd 
Tested-by: Randy Dunlap 
Reviewed-by: Randy Dunlap 
Reviewed-by: Linus Walleij 
Signed-off-by: Arnd Bergmann 
Signed-off-by: Jonathan Corbet

timekeeping/ntp: Constify some function arguments

2018-07-20T00:08:05+00:00

Add 'const' to some function arguments and variables to make it easier
to read the code.

Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Miroslav Lichvar 
Cc: Richard Cochran 
Cc: Prarit Bhargava 
Cc: Stephen Boyd 
Signed-off-by: Ondrej Mosnacek 
[jstultz: Also fixup pre-existing checkpatch warnings for
 prototype arguments with no variable name]
Signed-off-by: John Stultz

timekeeping: Replace read_boot_clock64() with read_persistent_wall_and_boot_offset()

2018-07-19T22:02:40+00:00

If architecture does not support exact boot time, it is challenging to
estimate boot time without having a reference to the current persistent
clock value. Yet, it cannot read the persistent clock time again, because
this may lead to math discrepancies with the caller of read_boot_clock64()
who have read the persistent clock at a different time.

This is why it is better to provide two values simultaneously: the
persistent clock value, and the boot time.

Replace read_boot_clock64() with:
read_persistent_wall_and_boot_offset(wall_time, boot_offset)

Where wall_time is returned by read_persistent_clock() And boot_offset is
wall_time - boot time, which defaults to 0.

Signed-off-by: Pavel Tatashin 
Signed-off-by: Thomas Gleixner 
Cc: steven.sistare@oracle.com
Cc: daniel.m.jordan@oracle.com
Cc: linux@armlinux.org.uk
Cc: schwidefsky@de.ibm.com
Cc: heiko.carstens@de.ibm.com
Cc: john.stultz@linaro.org
Cc: sboyd@codeaurora.org
Cc: hpa@zytor.com
Cc: douly.fnst@cn.fujitsu.com
Cc: peterz@infradead.org
Cc: prarit@redhat.com
Cc: feng.tang@intel.com
Cc: pmladek@suse.com
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: linux-s390@vger.kernel.org
Cc: boris.ostrovsky@oracle.com
Cc: jgross@suse.com
Cc: pbonzini@redhat.com
Link: https://lkml.kernel.org/r/20180719205545.16512-16-pasha.tatashin@oracle.com

timekeeping: Add more coarse clocktai/boottime interfaces

2018-05-19T11:57:33+00:00

The set of APIs we provide has a few holes for coarse times, e.g. we
provide ktime_get_coarse_boottime() and ktime_get_boottime_ts64(),
but not the combination of the two.

This adds four new functions:

ktime_get_coarse_boottime_ts64()
ktime_get_boottime_seconds()
ktime_get_coarse_clocktai_ts64()
ktime_get_clocktai_seconds()

to fill in some of the missing pieces. I have missed only the
ktime_get_boottime_seconds() accessor in a few occasions in
the past, but it seems better to just provide all four together,
as there is very little cost to having them.

Signed-off-by: Arnd Bergmann 
Signed-off-by: Thomas Gleixner 
Cc: Stephen Boyd 
Cc: y2038@lists.linaro.org
Cc: John Stultz 
Link: https://lkml.kernel.org/r/20180427134016.2525989-6-arnd@arndb.de