Commit Graph

101 Commits

Author SHA1 Message Date
Baolin Wang 39232ed5a1 time: Introduce one suspend clocksource to compensate the suspend time
On some hardware with multiple clocksources, we have coarse grained
clocksources that support the CLOCK_SOURCE_SUSPEND_NONSTOP flag, but
which are less than ideal for timekeeping whereas other clocksources
can be better candidates but halt on suspend.

Currently, the timekeeping core only supports timing suspend using
CLOCK_SOURCE_SUSPEND_NONSTOP clocksources if that clocksource is the
current clocksource for timekeeping.

As a result, some architectures try to implement read_persistent_clock64()
using those non-stop clocksources, but isn't really ideal, which will
introduce more duplicate code. To fix this, provide logic to allow a
registered SUSPEND_NONSTOP clocksource, which isn't the current
clocksource, to be used to calculate the suspend time.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
[jstultz: minor tweaks to merge with previous resume changes]
Signed-off-by: John Stultz <john.stultz@linaro.org>
2018-07-19 17:08:52 -07:00
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00
Linus Torvalds 1b044f1cfc Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner:
 "A rather large update for timers/timekeeping:

   - compat syscall consolidation (Al Viro)

   - Posix timer consolidation (Christoph Helwig / Thomas Gleixner)

   - Cleanup of the device tree based initialization for clockevents and
     clocksources (Daniel Lezcano)

   - Consolidation of the FTTMR010 clocksource/event driver (Linus
     Walleij)

   - The usual set of small fixes and updates all over the place"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (93 commits)
  timers: Make the cpu base lock raw
  clocksource/drivers/mips-gic-timer: Fix an error code in 'gic_clocksource_of_init()'
  clocksource/drivers/fsl_ftm_timer: Unmap region obtained by of_iomap
  clocksource/drivers/tcb_clksrc: Make IO endian agnostic
  clocksource/drivers/sun4i: Switch to the timer-of common init
  clocksource/drivers/timer-of: Fix invalid iomap check
  Revert "ktime: Simplify ktime_compare implementation"
  clocksource/drivers: Fix uninitialized variable use in timer_of_init
  kselftests: timers: Add test for frequency step
  kselftests: timers: Fix inconsistency-check to not ignore first timestamp
  time: Add warning about imminent deprecation of CONFIG_GENERIC_TIME_VSYSCALL_OLD
  time: Clean up CLOCK_MONOTONIC_RAW time handling
  posix-cpu-timers: Make timespec to nsec conversion safe
  itimer: Make timeval to nsec conversion range limited
  timers: Fix parameter description of try_to_del_timer_sync()
  ktime: Simplify ktime_compare implementation
  clocksource/drivers/fttmr010: Factor out clock read code
  clocksource/drivers/fttmr010: Implement delay timer
  clocksource/drivers: Add timer-of common init routine
  clocksource/drivers/tcb_clksrc: Save timer context on suspend/resume
  ...
2017-07-03 16:14:51 -07:00
Daniel Lezcano 8b7a3b5688 clocksource/drivers: Add an alias macro CLOCKSOURCE_OF_DECLARE
The macro CLOCKSOURCE_OF_DECLARE has been rename to TIMER_OF_DECLARE.

In order to prevent conflicts for the next merge window, a temporary
alias has been added which will be removed later.

Cc: Arnd Bergman <arnd@arndb.de>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2017-06-14 12:02:01 +02:00
Daniel Lezcano bb0eb050a5 clocksource/drivers: Rename CLKSRC_OF to TIMER_OF
The config option name is now renamed to 'TIMER_OF' for consistency with
the CLOCKSOURCE_OF_DECLARE => TIMER_OF_DECLARE change.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
2017-06-14 12:01:03 +02:00
Daniel Lezcano 2fcc112af3 clocksource/drivers: Rename clksrc table to timer
The table name is now renamed to 'timer' for consistency with
the CLOCKSOURCE_OF_DECLARE => TIMER_OF_DECLARE change.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
2017-06-14 12:00:33 +02:00
Daniel Lezcano 77d62f5322 clocksource/drivers: Rename CLOCKSOURCE_ACPI_DECLARE to TIMER_ACPI_DECLARE
The macro name is now renamed to 'TIMER_ACPI_DECLARE' for consistency
with the CLOCKSOURCE_OF_DECLARE => TIMER_OF_DECLARE change.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
2017-06-14 11:59:53 +02:00
Daniel Lezcano ba5d08c0ea clocksource/drivers: Rename clocksource_probe to timer_probe
The function name is now renamed to 'timer_probe' for consistency with
the CLOCKSOURCE_OF_DECLARE => TIMER_OF_DECLARE change.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
2017-06-14 11:59:16 +02:00
Daniel Lezcano 1727339590 clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE
The CLOCKSOURCE_OF_DECLARE macro is used widely for the timers to declare the
clocksource at early stage. However, this macro is also used to initialize
the clockevent if any, or the clockevent only.

It was originally suggested to declare another macro to initialize a
clockevent, so in order to separate the two entities even they belong to the
same IP. This was not accepted because of the impact on the DT where splitting
a clocksource/clockevent definition does not make sense as it is a Linux
concept not a hardware description.

On the other side, the clocksource has not interrupt declared while the
clockevent has, so it is easy from the driver to know if the description is
for a clockevent or a clocksource, IOW it could be implemented at the driver
level.

So instead of dealing with a named clocksource macro, let's use a more generic
one: TIMER_OF_DECLARE.

The patch has not functional changes.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Matthias Brugger <matthias.bgg@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
2017-06-14 11:58:45 +02:00
Peter Zijlstra b421b22b00 x86/tsc, sched/clock, clocksource: Use clocksource watchdog to provide stable sync points
Currently we keep sched_clock_tick() active for stable TSC in order to
keep the per-CPU state semi up-to-date. The (obvious) problem is that
by the time we detect TSC is borked, our per-CPU state is also borked.

So hook into the clocksource watchdog and call a method after we've
found it to still be stable.

There's the obvious race where the TSC goes wonky between finding it
stable and us running the callback, but closing that is too much work
and not really worth it, since we're already detecting TSC wobbles
after the fact, so we cannot, per definition, fully avoid funny clock
values.

And since the watchdog runs less often than the tick, this is also an
optimization.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-05-15 10:15:18 +02:00
Matthias Kaehlcke 0773cea374 clocksource: Use GENMASK_ULL in definition of CLOCKSOURCE_MASK
Besides reusing existing code this removes the special case handling
for 64-bit masks, which causes clang to raise a shift count overflow
warning due to https://bugs.llvm.org//show_bug.cgi?id=10030.

Suggested-by: Dmitry Torokhov <dtor@chromium.org>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Cc: Grant Grundler <grundler@chromium.org>
Cc: Greg Hackmann <ghackmann@google.com>
Cc: Michael Davidson <md@google.com>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170418233037.70990-1-mka@chromium.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-04-20 14:56:58 +02:00
Thomas Gleixner 12907fbb1a sched/clock, clocksource: Add optional cs::mark_unstable() method
PeterZ reported that we'd fail to mark the TSC unstable when the
clocksource watchdog finds it unsuitable.

Allow a clocksource to run a custom action when its being marked
unstable and hook up the TSC unstable code.

Reported-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14 11:29:43 +01:00
Thomas Gleixner a5a1d1c291 clocksource: Use a plain u64 instead of cycle_t
There is no point in having an extra type for extra confusion. u64 is
unambiguous.

Conversion was done with the following coccinelle script:

@rem@
@@
-typedef u64 cycle_t;

@fix@
typedef cycle_t;
@@
-cycle_t
+u64

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
2016-12-25 11:04:12 +01:00
Chris Metcalf ec4101e890 timekeeping/clocksource_cyc2ns: Document intended range limitation
The "cycles" argument should not be an absolute clocksource cycle
value, as the implementation's arithmetic will overflow relatively
easily with wide (64 bit) clocksource counters.

For performance, the implementation is simple and fast, since the
function is intended for only relatively small delta values of
clocksource cycles.

[jstultz: Fixed up to merge against HEAD & commit message tweaks,
 also included rewording suggestion by Ingo]
Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Link: http://lkml.kernel.org/r/1480372524-15181-4-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-29 18:02:58 +01:00
Daniel Lezcano 177cf6e52b clocksources: Switch back to the clksrc table
All the clocksource drivers's init function are now converted to return
an error code. CLOCKSOURCE_OF_DECLARE is no longer used as well as the
clksrc-of table.

Let's convert back the names:
 - CLOCKSOURCE_OF_DECLARE_RET => CLOCKSOURCE_OF_DECLARE
 - clksrc-of-ret              => clksrc-of

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

For exynos_mct and samsung_pwm_timer:
Acked-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>

For arch/arc:
Acked-by: Vineet Gupta <vgupta@synopsys.com>

For mediatek driver:
Acked-by: Matthias Brugger <matthias.bgg@gmail.com>

For the Rockchip-part
Acked-by: Heiko Stuebner <heiko@sntech.de>

For STi :
Acked-by: Patrice Chotard <patrice.chotard@st.com>

For the mps2-timer.c and versatile.c changes:
Acked-by: Liviu Dudau <Liviu.Dudau@arm.com>

For the OXNAS part :
Acked-by: Neil Armstrong <narmstrong@baylibre.com>

For LPC32xx driver:
Acked-by: Sylvain Lemieux <slemieux.tyco@gmail.com>

For Broadcom Kona timer change:
Acked-by: Ray Jui <ray.jui@broadcom.com>

For Sun4i and Sun5i:
Acked-by: Chen-Yu Tsai <wens@csie.org>

For Meson6:
Acked-by: Carlo Caione <carlo@caione.org>

For Keystone:
Acked-by: Santosh Shilimkar <ssantosh@kernel.org>

For NPS:
Acked-by: Noam Camus <noamca@mellanox.com>

For bcm2835:
Acked-by: Eric Anholt <eric@anholt.net>
2016-06-28 10:19:35 +02:00
Daniel Lezcano b7c4db8616 clocksource/drivers/clksrc-probe: Introduce init functions with return code
Currently, the clksrc-probe is not able to handle any error from the init
functions. There are different issues with the current code:
 - the code is duplicated in the init functions by writing error
 - every driver tends to panic in its own init function
 - counting the number of clocksources is not reliable

This patch adds another table to store the functions returning an error.
The table is temporary while we convert all the drivers to return an error
and will disappear.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2016-06-28 10:19:17 +02:00
David Lechner 02fad5e9b4 clocksource: Add missing include of of.h.
This header uses OF_DELCARE_1 which is defined in linux/of.h.

This fixes getting unhelpful compiler error messages about missing ')'
before a string constant.

Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2016-04-22 11:38:56 -07:00
Alexander Kuleshov 7aca0c0720 clocksource: Introduce clocksource_freq2mult()
The clocksource_khz2mult() and clocksource_hz2mult() share similar
code wihch calculates a mult from the given frequency. Both implementations
in differ only in value of a frequency. This patch introduces the
clocksource_freq2mult() helper with generic implementation of
mult calculation to prevent code duplication.

Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Link: http://lkml.kernel.org/r/1456542854-22104-2-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-02-27 08:55:30 +01:00
Thomas Gleixner 09a9982016 timekeeping: Lift clocksource cacheline restriction
We cache all hotpath members of a clocksource in the time keeper
core. So there is no requirement in general to cache line align struct
clocksource. Remove the enforces alignment.

That allows users which need to wrap struct clocksource into their own
struct to align the struct without getting extra padding.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Mans Rullgard <mans@mansr.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Sebastian Frias <sebastian_frias@sigmadesigns.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1511191209000.3898@nanos
2015-11-25 22:28:30 +01:00
Marc Zyngier 3722ed2380 clocksource: cosmetic: Drop OF 'dependency' from symbols
Seeing the 'of' characters in a symbol that is being called from
ACPI seems to freak out people. So let's do a bit of pointless
renaming so that these folks do feel at home.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-10-01 02:18:39 +02:00
Marc Zyngier ae281cbd26 clocksource / arm_arch_timer: Convert to ACPI probing
It is now absolutely trivial to convert the arch timer driver to
use ACPI probing, just like its DT counterpart.

Let's enjoy another crapectomy.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-10-01 02:18:39 +02:00
Marc Zyngier aad83b15aa clocksource: Add new CLKSRC_{PROBE,ACPI} config symbols
The clocksource probing infrastructure currently depends on
CONFIG_CLKSRC_OF, which depends on CONFIG_OF. In order to make
this infrastructure selectable even if CONFIG_OF is not selected,
introduce a new CONFIG_CLKSRC_PROBE (which allow the infrastructure
to be compiled in), and CONFIG_CLKSRC_ACPI (which is the pendent
of CONFIG_CLKSRC_OF for ACPI).

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-10-01 02:18:38 +02:00
Marc Zyngier c625f76a99 clocksource / ACPI: Add probing infrastructure for ACPI-based clocksources
DT enjoys a rather nice probing infrastructure for clocksources,
while ACPI is so far stuck into a very distant past.

This patch introduces a declarative API, allowing clocksources
to be self-contained and be called when parsing the GTDT table.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-10-01 02:18:38 +02:00
Thomas Gleixner c3b5d3cea5 Merge branch 'linus' into timers/core
Make sure the upstream fixes are applied before adding further
modifications.
2015-05-19 16:12:32 +02:00
Linus Torvalds 836ee4874e Initial ACPI support for arm64:
This series introduces preliminary ACPI 5.1 support to the arm64 kernel
 using the "hardware reduced" profile. We don't support any peripherals
 yet, so it's fairly limited in scope:
 
 - Memory init (UEFI)
 - ACPI discovery (RSDP via UEFI)
 - CPU init (FADT)
 - GIC init (MADT)
 - SMP boot (MADT + PSCI)
 - ACPI Kconfig options (dependent on EXPERT)
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull initial ACPI support for arm64 from Will Deacon:
 "This series introduces preliminary ACPI 5.1 support to the arm64
  kernel using the "hardware reduced" profile.  We don't support any
  peripherals yet, so it's fairly limited in scope:

   - MEMORY init (UEFI)

   - ACPI discovery (RSDP via UEFI)

   - CPU init (FADT)

   - GIC init (MADT)

   - SMP boot (MADT + PSCI)

   - ACPI Kconfig options (dependent on EXPERT)

  ACPI for arm64 has been in development for a while now and hardware
  has been available that can boot with either FDT or ACPI tables.  This
  has been made possible by both changes to the ACPI spec to cater for
  ARM-based machines (known as "hardware-reduced" in ACPI parlance) but
  also a Linaro-driven effort to get this supported on top of the Linux
  kernel.  This pull request is the result of that work.

  These changes allow us to initialise the CPUs, interrupt controller,
  and timers via ACPI tables, with memory information and cmdline coming
  from EFI.  We don't support a hybrid ACPI/FDT scheme.  Of course,
  there is still plenty of work to do (a serial console would be nice!)
  but I expect that to happen on a per-driver basis after this core
  series has been merged.

  Anyway, the diff stat here is fairly horrible, but splitting this up
  and merging it via all the different subsystems would have been
  extremely painful.  Instead, we've got all the relevant Acks in place
  and I've not seen anything other than trivial (Kconfig) conflicts in
  -next (for completeness, I've included my resolution below).  Nearly
  half of the insertions fall under Documentation/.

  So, we'll see how this goes.  Right now, it all depends on EXPERT and
  I fully expect people to use FDT by default for the immediate future"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (31 commits)
  ARM64 / ACPI: make acpi_map_gic_cpu_interface() as void function
  ARM64 / ACPI: Ignore the return error value of acpi_map_gic_cpu_interface()
  ARM64 / ACPI: fix usage of acpi_map_gic_cpu_interface
  ARM64: kernel: acpi: honour acpi=force command line parameter
  ARM64: kernel: acpi: refactor ACPI tables init and checks
  ARM64: kernel: psci: let ACPI probe PSCI version
  ARM64: kernel: psci: factor out probe function
  ACPI: move arm64 GSI IRQ model to generic GSI IRQ layer
  ARM64 / ACPI: Don't unflatten device tree if acpi=force is passed
  ARM64 / ACPI: additions of ACPI documentation for arm64
  Documentation: ACPI for ARM64
  ARM64 / ACPI: Enable ARM64 in Kconfig
  XEN / ACPI: Make XEN ACPI depend on X86
  ARM64 / ACPI: Select ACPI_REDUCED_HARDWARE_ONLY if ACPI is enabled on ARM64
  clocksource / arch_timer: Parse GTDT to initialize arch timer
  irqchip: Add GICv2 specific ACPI boot support
  ARM64 / ACPI: Introduce ACPI_IRQ_MODEL_GIC and register device's gsi
  ACPI / processor: Make it possible to get CPU hardware ID via GICC
  ACPI / processor: Introduce phys_cpuid_t for CPU hardware ID
  ARM64 / ACPI: Parse MADT for SMP initialization
  ...
2015-04-24 08:23:45 -07:00
Yingjoe Chen 4796cf9b02 time: Remove nonexistent function prototype
The function clocksource_get_next() was removed in commit 75c5158f70
(timekeeping: Update clocksource with stop_machine), but the
prototype was not removed with it. Remove the prototype.

Signed-off-by: Yingjoe Chen <yingjoe.chen@mediatek.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: <srv_heupstream@mediatek.com>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/1428674150-1780-1-git-send-email-yingjoe.chen@mediatek.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-22 12:03:39 +02:00
Hanjun Guo b09ca1ecf6 clocksource / arch_timer: Parse GTDT to initialize arch timer
Using the information presented by GTDT (Generic Timer Description Table)
to initialize the arch timer (not memory-mapped).

CC: Daniel Lezcano <daniel.lezcano@linaro.org>
CC: Thomas Gleixner <tglx@linutronix.de>
Originally-by: Amit Daniel Kachhap <amit.daniel@samsung.com>
Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Tested-by: Yijing Wang <wangyijing@huawei.com>
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Jon Masters <jcm@redhat.com>
Tested-by: Timur Tabi <timur@codeaurora.org>
Tested-by: Robert Richter <rrichter@cavium.com>
Acked-by: Robert Richter <rrichter@cavium.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-03-26 15:13:07 +00:00
John Stultz fba9e07208 clocksource: Rename __clocksource_updatefreq_*() to __clocksource_update_freq_*()
Ingo requested this function be renamed to improve readability,
so I've renamed __clocksource_updatefreq_scale() as well as the
__clocksource_updatefreq_hz/khz() functions to avoid
squishedtogethernames.

This touches some of the sh clocksources, which I've not tested.

The arch/arm/plat-omap change is just a comment change for
consistency.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1426133800-29329-13-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-13 08:07:08 +01:00
John Stultz f8935983f1 clocksource: Mostly kill clocksource_register()
A long running project has been to clean up remaining uses
of clocksource_register(), replacing it with the simpler
clocksource_register_khz/hz() functions.

However, there are a few cases where we need to self-define
our mult/shift values, so switch the function to a more
obviously internal __clocksource_register() name, and
consolidate much of the internal logic so we don't have
duplication.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: David S. Miller <davem@davemloft.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1426133800-29329-10-git-send-email-john.stultz@linaro.org
[ Minor cleanups. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-13 08:07:06 +01:00
John Stultz fb82fe2fe8 clocksource: Add 'max_cycles' to 'struct clocksource'
In order to facilitate clocksource validation, add a
'max_cycles' field to the clocksource structure which
will hold the maximum cycle value that can safely be
multiplied without potentially causing an overflow.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1426133800-29329-4-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-12 10:16:38 +01:00
Richard Cochran 74d23cc704 time: move the timecounter/cyclecounter code into its own file.
The timecounter code has almost nothing to do with the clocksource
code. Let it live in its own file. This will help isolate the
timecounter users from the clocksource users in the source tree.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-30 18:29:25 -05:00
Bjorn Helgaas 96a2adbc6f clocksource: Remove "weak" from clocksource_default_clock() declaration
kernel/time/jiffies.c provides a default clocksource_default_clock()
definition explicitly marked "weak".  arch/s390 provides its own definition
intended to override the default, but the "weak" attribute on the
declaration applied to the s390 definition as well, so the linker chose one
based on link order (see 10629d711e ("PCI: Remove __weak annotation from
pcibios_get_phb_of_node decl")).

Remove the "weak" attribute from the clocksource_default_clock()
declaration so we always prefer a non-weak definition over the weak one,
independent of link order.

Fixes: f1b82746c1 ("clocksource: Cleanup clocksource selection")
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: John Stultz <john.stultz@linaro.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
CC: Daniel Lezcano <daniel.lezcano@linaro.org>
CC: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-10-22 16:14:03 -06:00
Thomas Gleixner 4a0e637738 clocksource: Get rid of cycle_last
cycle_last was added to the clocksource to support the TSC
validation. We moved that to the core code, so we can get rid of the
extra copy.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 15:01:52 -07:00
Rob Herring 54196ccbe0 of: consolidate linker section OF match table declarations
We now have several OF match tables using linker sections that are
nearly the same definition. The only variation is the callback function
prototype. Create a common define for creating linker section OF match
table entries which each table declaration can use.

Acked-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Rob Herring <robh@kernel.org>
2014-05-20 14:25:24 -05:00
Stephen Boyd 87d8b9eb7e clocksource: Extract max nsec calculation into separate function
We need to calculate the same number in the clocksource code and
the sched_clock code, so extract this code into its own function.
We also drop the min_t and just use min() because the two types
are the same.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-07-30 11:24:20 -07:00
Thomas Gleixner 332962f2c8 clocksource: Reselect clocksource when watchdog validated high-res capability
Up to commit 5d33b883a (clocksource: Always verify highres capability)
we had no sanity check when selecting a clocksource, which prevented
that a non highres capable clocksource is used when the system already
switched to highres/nohz mode.

The new sanity check works as Alex and Tim found out. It prevents the
TSC from being used. This happens because on x86 the boot process
looks like this:

 tsc_start_freqency_validation(TSC);
 clocksource_register(HPET);
 clocksource_done_booting();
	clocksource_select()
		Selects HPET which is valid for high-res

 switch_to_highres();

 clocksource_register(TSC);
 	TSC is not selected, because it is not yet
	flagged as VALID_HIGH_RES

 clocksource_watchdog()
	Validates TSC for highres, but that does not make TSC
	the current clocksource.

Before the sanity check was added, we installed TSC unvalidated which
worked most of the time. If the TSC was really detected as unstable,
then the unstable logic removed it and installed HPET again.

The sanity check is correct and needed. So the watchdog needs to kick
a reselection of the clocksource, when it qualifies TSC as a valid
high res clocksource.

To solve this, we mark the clocksource which got the flag
CLOCK_SOURCE_VALID_FOR_HRES set by the watchdog with an new flag
CLOCK_SOURCE_RESELECT and trigger the watchdog thread. The watchdog
thread evaluates the flag and invokes clocksource_select() when set.

To avoid that the clocksource_done_booting() code, which is about to
install the first real clocksource anyway, needs to go through
clocksource_select and tick_oneshot_notify() pointlessly, split out
the clocksource_watchdog_kthread() list walk code and invoke the
select/notify only when called from clocksource_watchdog_kthread().

So clocksource_done_booting() can utilize the same splitout code
without the select/notify invocation and the clocksource_mutex
unlock/relock dance.

Reported-and-tested-by: Alex Shi <alex.shi@intel.com>
Cc: Hans Peter Anvin <hpa@linux.intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <andi.kleen@intel.com>
Tested-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1307042239150.11637@ionos.tec.linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-07-05 11:09:28 +02:00
Thomas Gleixner a89c7edbe7 clocksource: Let clocksource_unregister() return success/error
The unregister call can fail, if the clocksource is the current one
and there is no replacement clocksource available. It can also fail,
if the clocksource is the watchdog clocksource and I'm not going to
provide support for this.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Magnus Damm <magnus.damm@gmail.com>
Link: http://lkml.kernel.org/r/20130425143436.029915527@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-05-16 11:09:16 +02:00
Thomas Gleixner 09ac369c82 clocksource: Add module refcount
Add a module refcount, so the current clocksource cannot be removed
unconditionally.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Magnus Damm <magnus.damm@gmail.com>
Link: http://lkml.kernel.org/r/20130425143435.762417789@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-05-16 11:09:14 +02:00
Thomas Gleixner ba919d1caa clocksource: Let timekeeping_notify return success/error
timekeeping_notify() can fail due cs->enable() failure. Though the
caller does not notice and happily keeps the wrong clocksource as the
current one.

Let the caller know about failure, so the current clocksource will be
shown correctly in sysfs.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <john.stultz@linaro.org>
Cc: Magnus Damm <magnus.damm@gmail.com>
Link: http://lkml.kernel.org/r/20130425143435.696321912@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-05-16 11:09:14 +02:00
Linus Torvalds a7726350e0 ARM: arm-soc cleanup for 3.10
Here is a collection of cleanup patches. Among the pieces that stand out are:
 
 - The deletion of h720x platforms
 - Split of at91 non-dt platforms to their own Kconfig file to keep them separate
 - General cleanups and refactoring of i.MX and MXS platforms
 - Some restructuring of clock tables for OMAP
 - Convertion of PMC driver for Tegra to dt-only
 - Some renames of sunxi -> sun4i (Allwinner A10)
 - ... plus a bunch of other stuff that I haven't mentioned
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Merge tag 'cleanup-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull ARM SoC cleanup from Olof Johansson:
 "Here is a collection of cleanup patches.  Among the pieces that stand
  out are:

   - The deletion of h720x platforms
   - Split of at91 non-dt platforms to their own Kconfig file to keep
     them separate
   - General cleanups and refactoring of i.MX and MXS platforms
   - Some restructuring of clock tables for OMAP
   - Convertion of PMC driver for Tegra to dt-only
   - Some renames of sunxi -> sun4i (Allwinner A10)
   - ... plus a bunch of other stuff that I haven't mentioned"

* tag 'cleanup-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (119 commits)
  ARM: i.MX: remove unused ARCH_* configs
  ARM i.MX53: remove platform ahci support
  ARM: sunxi: Rework the restart code
  irqchip: sunxi: Rename sunxi to sun4i
  irqchip: sunxi: Make use of the IRQCHIP_DECLARE macro
  clocksource: sunxi: Rename sunxi to sun4i
  clocksource: sunxi: make use of CLKSRC_OF
  clocksource: sunxi: Cleanup the timer code
  ARM: at91: remove trailing semicolon from macros
  ARM: at91/setup: fix trivial typos
  ARM: EXYNOS: remove "config EXYNOS_DEV_DRM"
  ARM: EXYNOS: change the name of USB ohci header
  ARM: SAMSUNG: Remove unnecessary code for dma
  ARM: S3C24XX: Remove unused GPIO drive strength register definitions
  ARM: OMAP4+: PM: Restore CPU power state to ON with clockdomain force wakeup method
  ARM: S3C24XX: Removed unneeded dependency on CPU_S3C2412
  ARM: S3C24XX: Removed unneeded dependency on CPU_S3C2410
  ARM: S3C24XX: Removed unneeded dependency on ARCH_S3C24XX for boards
  ARM: SAMSUNG: Fix typo "CONFIG_SAMSUNG_DEV_RTC"
  ARM: S5P64X0: Fix typo "CONFIG_S5P64X0_SETUP_SDHCI"
  ...
2013-05-02 09:03:55 -07:00
Arnd Bergmann 3d5a965823 clocksource: make CLOCKSOURCE_OF_DECLARE type safe
This ensures that a function pointer passed into CLOCKSOURCE_OF_DECLARE
takes the same arguments that we use for calling that function later.

Also fix the extraneous semicolon at end of the CLOCKSOURCE_OF_DECLARE
definition.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Rob Herring <rob.herring@calxeda.com>
2013-03-28 12:01:06 +01:00
Feng Tang 5caf463625 clocksource: Add new feature flag CLOCK_SOURCE_SUSPEND_NONSTOP
Some x86 processors have a TSC clocksource, which continues to run
even when system is suspended. Also most OMAP platforms have a
32 KHz timer which has similar capability. Add a feature flag so that
it could be utilized.

Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-03-15 16:50:27 -07:00
Rob Herring e0c2536238 clocksource: add empty version of clocksource_of_init
Add an empty clocksource_of_init when !CLKSRC_OF. This is needed for builds
where no timer has selected CLKSRC_OF.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-03-11 08:40:12 -05:00
Stephen Warren e1d7ef1cc4 clocksource: always define CLOCKSOURCE_OF_DECLARE
This allows clocksource drivers that support both DT and non-DT to
always invoke macro CLOCKSOURCE_OF_DECLARE(), rather than wrapping
it in a #ifdef CONFIG_CLKSRC_OF, which simplifies their code.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
2013-01-31 19:57:30 -08:00
Stephen Warren ae278a935f clocksource: add common of_clksrc_init() function
It is desirable to move all clocksource drivers to drivers/clocksource,
yet each requires its own initialization function. We'd rather not
pollute <linux/> with a header for each function. Instead, create a
single of_clksrc_init() function which will determine which clocksource
driver to initialize based on device tree.

Based on a similar patch for drivers/irqchip by Thomas Petazzoni.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
2013-01-02 11:07:43 -07:00
John Stultz 189374aed6 time: Move update_vsyscall definitions to timekeeper_internal.h
Since users will need to include timekeeper_internal.h, move
update_vsyscall definitions to timekeeper_internal.h.

Cc: Tony Luck <tony.luck@intel.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2012-09-24 12:38:06 -04:00
Yong Zhang c7f798e372 clocksource: Get rid of clocksource_calc_mult_shift()
No one is using this, so encourage the use of
clocksource_register_hz/khz(), and drop this helper.

Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
[jstultz: tweaked commit message]
Signed-off-by: John Stultz <john.stultz@linaro.org>
2012-02-01 18:37:39 -08:00
Kusanagi Kouichi b1b73d0950 time/clocksource: Fix kernel-doc warnings
Fix various KernelDoc build warnings.

Signed-off-by: Kusanagi Kouichi <slash@ac.auone-net.jp>
Cc: John Stultz <johnstul@us.ibm.com>
Link: http://lkml.kernel.org/r/20111219091320.0D5AF6FC03D@msa105.auone-net.jp
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-19 11:41:40 +01:00
John Stultz d65670a78c clocksource: Avoid selecting mult values that might overflow when adjusted
For some frequencies, the clocks_calc_mult_shift() function will
unfortunately select mult values very close to 0xffffffff.  This
has the potential to overflow when NTP adjusts the clock, adding
to the mult value.

This patch adds a clocksource.maxadj value, which provides
an approximation of an 11% adjustment(NTP limits adjustments to
500ppm and the tick adjustment is limited to 10%), which could
be made to the clocksource.mult value. This is then used to both
check that the current mult value won't overflow/underflow, as
well as warning us if the timekeeping_adjust() code pushes over
that 11% boundary.

v2: Fix max_adjustment calculation, and improve WARN_ONCE
messages.

v3: Don't warn before maxadj has actually been set

CC: Yong Zhang <yong.zhang0@gmail.com>
CC: David Daney <ddaney.cavm@gmail.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Chen Jie <chenj@lemote.com>
CC: zhangfx <zhangfx@lemote.com>
CC: stable@kernel.org
Reported-by: Chen Jie <chenj@lemote.com>
Reported-by: zhangfx <zhangfx@lemote.com>
Tested-by: Yong Zhang <yong.zhang0@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2011-11-10 11:27:08 -08:00
Linus Torvalds 8e204874db Merge branch 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86-64, vdso: Do not allocate memory for the vDSO
  clocksource: Change __ARCH_HAS_CLOCKSOURCE_DATA to a CONFIG option
  x86, vdso: Drop now wrong comment
  Document the vDSO and add a reference parser
  ia64: Replace clocksource.fsys_mmio with generic arch data
  x86-64: Move vread_tsc and vread_hpet into the vDSO
  clocksource: Replace vread with generic arch data
  x86-64: Add --no-undefined to vDSO build
  x86-64: Allow alternative patching in the vDSO
  x86: Make alternative instruction pointers relative
  x86-64: Improve vsyscall emulation CS and RIP handling
  x86-64: Emulate legacy vsyscalls
  x86-64: Fill unused parts of the vsyscall page with 0xcc
  x86-64: Remove vsyscall number 3 (venosys)
  x86-64: Map the HPET NX
  x86-64: Remove kernel.vsyscall64 sysctl
  x86-64: Give vvars their own page
  x86-64: Document some of entry_64.S
  x86-64: Fix alignment of jiffies variable
2011-07-22 17:05:15 -07:00