cpumask: make core headers including cpumask_types.h where possible

Now that cpumask types are split out to a separate smaller header, many
frequently included core headers may switch to using it.

cpumask: make core headers including cpumask_types.h where possible

Now that cpumask types are split out to a separate smaller header, many
frequently included core headers may switch to using it.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Yury Norov <[email protected]>
Cc: Amit Daniel Kachhap <[email protected]>
Cc: Anna-Maria Behnsen <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Daniel Lezcano <[email protected]>
Cc: Dennis Zhou <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Juri Lelli <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ulf Hansson <[email protected]>
Cc: Vincent Guittot <[email protected]>
Cc: Viresh Kumar <[email protected]>
Cc: Yury Norov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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cpuidle: Fix ct_idle_*() usage

The whole disable-RCU, enable-IRQS dance is very intricate since
changing IRQ state is traced, which depends on RCU.

Add two helpers for the cpuidle case that mirror

cpuidle: Fix ct_idle_*() usage

The whole disable-RCU, enable-IRQS dance is very intricate since
changing IRQ state is traced, which depends on RCU.

Add two helpers for the cpuidle case that mirror the entry code:

ct_cpuidle_enter()
ct_cpuidle_exit()

And fix all the cases where the enter/exit dance was buggy.

Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Tested-by: Tony Lindgren <[email protected]>
Tested-by: Ulf Hansson <[email protected]>
Acked-by: Rafael J. Wysocki <[email protected]>
Acked-by: Frederic Weisbecker <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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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

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 <[email protected]>
Reviewed-by: Philippe Ombredanne <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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Revert "clockevents: Add a clkevt-of mechanism like clksrc-of"

After discussing it, this feature is dropped as it is not considered
adequate:

https://patchwork.kernel.org/patch/9639317/

There is

Revert "clockevents: Add a clkevt-of mechanism like clksrc-of"

After discussing it, this feature is dropped as it is not considered
adequate:

https://patchwork.kernel.org/patch/9639317/

There is no user of this macro yet, so there is no impact on the drivers.

This reverts commit 376bc27150f180d9f5eddec6a14117780177589d.

Cc: Mark Rutland <[email protected]>
Signed-off-by: Daniel Lezcano <[email protected]>

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clockevents: Fix syntax error in clkevt-of macro

The patch fix syntax errors introduced by commit 0c8893c9095d
("clockevents: Add a clkevt-of mechanism like clksrc-of").

Fixes: 0c8893c9095d ("clock

clockevents: Fix syntax error in clkevt-of macro

The patch fix syntax errors introduced by commit 0c8893c9095d
("clockevents: Add a clkevt-of mechanism like clksrc-of").

Fixes: 0c8893c9095d ("clockevents: Add a clkevt-of mechanism like clksrc-of")
Signed-off-by: Alexander Kochetkov <[email protected]>
Signed-off-by: Daniel Lezcano <[email protected]>

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clockevents: Make clockevents_config() static

A clockevent device's rate should be configured before or at registration
and changed afterwards through clockevents_update_freq() only.

For the config

clockevents: Make clockevents_config() static

A clockevent device's rate should be configured before or at registration
and changed afterwards through clockevents_update_freq() only.

For the configuration at registration, we already have
clockevents_config_and_register().

Right now, there are no clockevents_config() users outside of the
clockevents core.

To mitigiate the risk of drivers errorneously reconfiguring their rates
through clockevents_config() *after* device registration, make
clockevents_config() static.

Signed-off-by: Nicolai Stange <[email protected]>
Signed-off-by: John Stultz <[email protected]>

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clockevents: Add a clkevt-of mechanism like clksrc-of

The current code uses the CLOCKSOURCE_OF_DECLARE macro to fill the clksrc
table with a t-uple (name, init_function).

Unfortunately it ends up t

clockevents: Add a clkevt-of mechanism like clksrc-of

The current code uses the CLOCKSOURCE_OF_DECLARE macro to fill the clksrc
table with a t-uple (name, init_function).

Unfortunately it ends up to the clockevent and the clocksource being
both initialized with this macro. It is not a problem by itself but there
is not a clear distinction between a clockevent and a clocksource in the
code initialization path. Somebody can argue there are the same IP block
and the same DT node. But conceptually from the software side, there are
two distincts entities and as is they should be initialized separetely.
Some drivers which do not have a clocksource end up by using the
CLOCKSOURCE_OF_DECLARE macro to declare a clockevent.

Another result is the fuzzy organization in the clocksource directory,
where the clockevents are implemented in the same file than the
clocksources or file labelled timer-something implementing a clocksource.

This patch provides another macro to specifically declare a clockevent in
the same way than the clocksource and gives the opportunity to write two
separate drivers, one for the clocksource and another for the clockevents.

Hopefully, that can help to do some housework in the directory, perhaps
split the drivers in to entities, for example:
- clksrc-rockchip.c
- clkevt-rockchip.c

Also, it gives the possibility to declare clocksources separately in the
DT and then use a clocksource from IP block while while clockevents are
used from another IP block.

Signed-off-by: Daniel Lezcano <[email protected]>

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clockevents: Rename last parameter of clocks_calc_mult_shift() to maxsec

Last parameter of the clocks_calc_mult_shift() was renamed from minsec to
maxsec in the 5fdade95 (time: Rename misnamed minse

clockevents: Rename last parameter of clocks_calc_mult_shift() to maxsec

Last parameter of the clocks_calc_mult_shift() was renamed from minsec to
maxsec in the 5fdade95 (time: Rename misnamed minsec argument of
clocks_calc_mult_shift()).

Signed-off-by: Alexander Kuleshov <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Thomas Gleixner <[email protected]>

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clockevents: Remove unused set_mode() callback

All users are migrated to the per-state callbacks, get rid of the
unused interface and the core support code.

Signed-off-by: Viresh Kumar <viresh.kuma

clockevents: Remove unused set_mode() callback

All users are migrated to the per-state callbacks, get rid of the
unused interface and the core support code.

Signed-off-by: Viresh Kumar <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: John Stultz <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/fd60de14cf6d125489c031207567bb255ad946f6.1441943991.git.viresh.kumar@linaro.org
Signed-off-by: Ingo Molnar <[email protected]>

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clockevents: Remove clockevents_notify() prototype

This function no longer exists after commit a49b116dcb12
(clockevents: Cleanup dead cpu explicitely, 2015-04-03). Remove
the prototype and the stub

clockevents: Remove clockevents_notify() prototype

This function no longer exists after commit a49b116dcb12
(clockevents: Cleanup dead cpu explicitely, 2015-04-03). Remove
the prototype and the stub function.

Signed-off-by: Stephen Boyd <[email protected]>
Cc: [email protected]
Cc: Rafael J. Wysocki <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Thomas Gleixner <[email protected]>

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clockevents: Rename state to state_use_accessors

The only sensible way to make abuse of core internal fields obvious
and easy to grep for.

Signed-off-by: Thomas Gleixner <[email protected]>
Cc: Vi

clockevents: Rename state to state_use_accessors

The only sensible way to make abuse of core internal fields obvious
and easy to grep for.

Signed-off-by: Thomas Gleixner <[email protected]>
Cc: Viresh Kumar <[email protected]>
Cc: Peter Zijlstra <[email protected]>

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clockevents: Add helpers to check the state of a clockevent device

Some clockevent drivers, once migrated to use per-state callbacks,
need to check the state of the clockevent device in their callba

clockevents: Add helpers to check the state of a clockevent device

Some clockevent drivers, once migrated to use per-state callbacks,
need to check the state of the clockevent device in their callbacks or
interrupt handler.

Add accessor functions clockevent_state_*() to get this information.

Signed-off-by: Viresh Kumar <[email protected]>
Cc: [email protected]
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/04a717d490335c688dd7af899fbcede97e1bb8ee.1432192527.git.viresh.kumar@linaro.org
Signed-off-by: Thomas Gleixner <[email protected]>

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clockevents: Introduce CLOCK_EVT_STATE_ONESHOT_STOPPED state

When no timers/hrtimers are pending, the expiry time is set to a
special value: 'KTIME_MAX'. This normally happens with
NO_HZ_{IDLE|FULL}

clockevents: Introduce CLOCK_EVT_STATE_ONESHOT_STOPPED state

When no timers/hrtimers are pending, the expiry time is set to a
special value: 'KTIME_MAX'. This normally happens with
NO_HZ_{IDLE|FULL} in both LOWRES/HIGHRES modes.

When 'expiry == KTIME_MAX', we either cancel the 'tick-sched' hrtimer
(NOHZ_MODE_HIGHRES) or skip reprogramming clockevent device
(NOHZ_MODE_LOWRES). But, the clockevent device is already
reprogrammed from the tick-handler for next tick.

As the clock event device is programmed in ONESHOT mode it will at
least fire one more time (unnecessarily). Timers on few
implementations (like arm_arch_timer, etc.) only support PERIODIC mode
and their drivers emulate ONESHOT over that. Which means that on these
platforms we will get spurious interrupts periodically (at last
programmed interval rate, normally tick rate).

In order to avoid spurious interrupts, the clockevent device should be
stopped or its interrupts should be masked.

A simple (yet hacky) solution to get this fixed could be: update
hrtimer_force_reprogram() to always reprogram clockevent device and
update clockevent drivers to STOP generating events (or delay it to
max time) when 'expires' is set to KTIME_MAX. But the drawback here is
that every clockevent driver has to be hacked for this particular case
and its very easy for new ones to miss this.

However, Thomas suggested to add an optional state ONESHOT_STOPPED to
solve this problem: lkml.org/lkml/2014/5/9/508.

This patch adds support for ONESHOT_STOPPED state in clockevents
core. It will only be available to drivers that implement the
state-specific callbacks instead of the legacy ->set_mode() callback.

Signed-off-by: Viresh Kumar <[email protected]>
Reviewed-by: Preeti U. Murthy <[email protected]>
Cc: [email protected]
Cc: Frederic Weisbecker <[email protected]>
Cc: Kevin Hilman <[email protected]>
Cc: Daniel Lezcano <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/b8b383a03ac07b13312c16850b5106b82e4245b5.1428031396.git.viresh.kumar@linaro.org
Signed-off-by: Thomas Gleixner <[email protected]>

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clockevents: Cleanup dead cpu explicitely

clockevents_notify() is a leftover from the early design of the
clockevents facility. It's really not a notification mechanism,
it's a multiplex call. We ar

clockevents: Cleanup dead cpu explicitely

clockevents_notify() is a leftover from the early design of the
clockevents facility. It's really not a notification mechanism,
it's a multiplex call. We are way better off to have explicit
calls instead of this monstrosity.

Split out the cleanup function for a dead cpu and invoke it
directly from the cpu down code. Make it conditional on
CPU_HOTPLUG as well.

Temporary change, will be refined in the future.

Signed-off-by: Thomas Gleixner <[email protected]>
[ Rebased, added clockevents_notify() removal ]
Signed-off-by: Rafael J. Wysocki <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

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clockevents: Make tick handover explicit

clockevents_notify() is a leftover from the early design of the
clockevents facility. It's really not a notification mechanism,
it's a multiplex call. We are

clockevents: Make tick handover explicit

clockevents_notify() is a leftover from the early design of the
clockevents facility. It's really not a notification mechanism,
it's a multiplex call. We are way better off to have explicit
calls instead of this monstrosity.

Split out the tick_handover call and invoke it explicitely from
the hotplug code. Temporary solution will be cleaned up in later
patches.

Signed-off-by: Thomas Gleixner <[email protected]>
[ Rebase ]
Signed-off-by: Rafael J. Wysocki <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: John Stultz <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Andrew Morton <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

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clockevents: Remove broadcast oneshot control leftovers

Now that all users are converted over to explicit calls into the
clockevents state machine, remove the notification chain leftovers.

Original

clockevents: Remove broadcast oneshot control leftovers

Now that all users are converted over to explicit calls into the
clockevents state machine, remove the notification chain leftovers.

Original-from: Thomas Gleixner <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: John Stultz <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

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clockevents: Remove the broadcast control leftovers

All users converted. Remove the notify leftovers.

Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Rafael J. Wysocki <rafael.j.

clockevents: Remove the broadcast control leftovers

All users converted. Remove the notify leftovers.

Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

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clockevents: Clean up clockchips.h

Do various cleanups on the clockchips.h file:

- indent preprocessor blocks to make it more clear which block we are in,
this also makes merge resolution easie

clockevents: Clean up clockchips.h

Do various cleanups on the clockchips.h file:

- indent preprocessor blocks to make it more clear which block we are in,
this also makes merge resolution easier

- comment larger preprocessor blocks consistently, using the:

#if FOO
...
#else /* !FOO: */
...
#endif /* !FOO */

notation.

- unbreak lines

- etc.

No change in functionality.

Cc: Peter Zijlstra <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>

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arm/bL_switcher: Kill tick suspend hackery

Use the new tick_suspend/resume_local() and get rid of the
homebrewn implementation of these in the ARM bL switcher. The
check for the cpumask is complete

arm/bL_switcher: Kill tick suspend hackery

Use the new tick_suspend/resume_local() and get rid of the
homebrewn implementation of these in the ARM bL switcher. The
check for the cpumask is completely pointless. There is no harm
to suspend a per cpu tick device unconditionally. If that's a
real issue then we fix it proper at the core level and not with
some completely undocumented hacks in some random core code.

Move the tick internals to the core code, now that this nuisance
is gone.

Signed-off-by: Thomas Gleixner <[email protected]>
[ rjw: Rebase, changelog ]
Signed-off-by: Rafael J. Wysocki <[email protected]>
Cc: Nicolas Pitre <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Russell King <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

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clockevents: Make suspend/resume calls explicit

clockevents_notify() is a leftover from the early design of the
clockevents facility. It's really not a notification mechanism,
it's a multiplex call.

clockevents: Make suspend/resume calls explicit

clockevents_notify() is a leftover from the early design of the
clockevents facility. It's really not a notification mechanism,
it's a multiplex call.

We are way better off to have explicit calls instead of this
monstrosity. Split out the suspend/resume() calls and invoke
them directly from the call sites.

No locking required at this point because these calls happen
with interrupts disabled and a single cpu online.

Signed-off-by: Thomas Gleixner <[email protected]>
[ Rebased on top of 4.0-rc5. ]
Signed-off-by: Rafael J. Wysocki <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
[ Rebased on top of latest timers/core. ]
Signed-off-by: Ingo Molnar <[email protected]>

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tick: Move core only declarations and functions to core

No point to expose everything to the world. People just believe
such functions can be abused for whatever purposes. Sigh.

Signed-off-by: Thom

tick: Move core only declarations and functions to core

No point to expose everything to the world. People just believe
such functions can be abused for whatever purposes. Sigh.

Signed-off-by: Thomas Gleixner <[email protected]>
[ Rebased on top of 4.0-rc5 ]
Signed-off-by: Rafael J. Wysocki <[email protected]>
Cc: Nicolas Pitre <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
[ Merged to latest timers/core ]
Signed-off-by: Ingo Molnar <[email protected]>

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clockevents: Remove CONFIG_GENERIC_CLOCKEVENTS_BUILD

This option was for simpler migration to the clock events code.
Most architectures have been converted and the option has been
disfunctional as a

clockevents: Remove CONFIG_GENERIC_CLOCKEVENTS_BUILD

This option was for simpler migration to the clock events code.
Most architectures have been converted and the option has been
disfunctional as a standalone option for quite some time. Remove
it.

Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

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clockevents: Manage device's state separately for the core

'enum clock_event_mode' is used for two purposes today:

- to pass mode to the driver of clockevent device::set_mode().

- for managing s

clockevents: Manage device's state separately for the core

'enum clock_event_mode' is used for two purposes today:

- to pass mode to the driver of clockevent device::set_mode().

- for managing state of the device for clockevents core.

For supporting new modes/states we have moved away from the
legacy set_mode() callback to new per-mode/state callbacks. New
modes/states shouldn't be exposed to the legacy (now OBSOLOTE)
callbacks and so we shouldn't add new states to 'enum
clock_event_mode'.

Lets have separate enums for the two use cases mentioned above.
Keep using the earlier enum for legacy set_mode() callback and
mark it OBSOLETE. And add another enum to clearly specify the
possible states of a clockevent device.

This also renames the newly added per-mode callbacks to reflect
state changes.

We haven't got rid of 'mode' member of 'struct
clock_event_device' as it is used by some of the clockevent
drivers and it would automatically die down once we migrate
those drivers to the new interface. It ('mode') is only updated
now for the drivers using the legacy interface.

Suggested-by: Peter Zijlstra <[email protected]>
Suggested-by: Ingo Molnar <[email protected]>
Signed-off-by: Viresh Kumar <[email protected]>
Acked-by: Peter Zijlstra <[email protected]>
Cc: Daniel Lezcano <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Kevin Hilman <[email protected]>
Cc: Preeti U Murthy <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/b6b0143a8a57bd58352ad35e08c25424c879c0cb.1425037853.git.viresh.kumar@linaro.org
Signed-off-by: Ingo Molnar <[email protected]>

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clockevents: Handle tick device's resume separately

Upcoming patch will redefine possible states of a clockevent
device. The RESUME mode is a special case only for tick's
clockevent devices. In futu

clockevents: Handle tick device's resume separately

Upcoming patch will redefine possible states of a clockevent
device. The RESUME mode is a special case only for tick's
clockevent devices. In future it can be replaced by ->resume()
callback already available for clockevent devices.

Lets handle it separately so that clockevents_set_mode() only
handles states valid across all devices. This also renames
set_mode_resume() to tick_resume() to make it more explicit.

Signed-off-by: Viresh Kumar <[email protected]>
Acked-by: Peter Zijlstra <[email protected]>
Cc: Daniel Lezcano <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Kevin Hilman <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Preeti U Murthy <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/c1b0112410870f49e7bf06958e1483eac6c15e20.1425037853.git.viresh.kumar@linaro.org
Signed-off-by: Ingo Molnar <[email protected]>

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clockevents: Introduce mode specific callbacks

It is not possible for the clockevents core to know which modes (other than
those with a corresponding feature flag) are supported by a particular
impl

clockevents: Introduce mode specific callbacks

It is not possible for the clockevents core to know which modes (other than
those with a corresponding feature flag) are supported by a particular
implementation. And drivers are expected to handle transition to all modes
elegantly, as ->set_mode() would be issued for them unconditionally.

Now, adding support for a new mode complicates things a bit if we want to use
the legacy ->set_mode() callback. We need to closely review all clockevents
drivers to see if they would break on addition of a new mode. And after such
reviews, it is found that we have to do non-trivial changes to most of the
drivers [1].

Introduce mode-specific set_mode_*() callbacks, some of which the drivers may or
may not implement. A missing callback would clearly convey the message that the
corresponding mode isn't supported.

A driver may still choose to keep supporting the legacy ->set_mode() callback,
but ->set_mode() wouldn't be supporting any new modes beyond RESUME. If a driver
wants to benefit from using a new mode, it would be required to migrate to
the mode specific callbacks.

The legacy ->set_mode() callback and the newly introduced mode-specific
callbacks are mutually exclusive. Only one of them should be supported by the
driver.

Sanity check is done at the time of registration to distinguish between optional
and required callbacks and to make error recovery and handling simpler. If the
legacy ->set_mode() callback is provided, all mode specific ones would be
ignored by the core but a warning is thrown if they are present.

Call sites calling ->set_mode() directly are also updated to use
__clockevents_set_mode() instead, as ->set_mode() may not be available anymore
for few drivers.

[1] https://lkml.org/lkml/2014/12/9/605
[2] https://lkml.org/lkml/2015/1/23/255

Suggested-by: Thomas Gleixner <[email protected]> [2]
Signed-off-by: Viresh Kumar <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Daniel Lezcano <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: John Stultz <[email protected]>
Cc: Kevin Hilman <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Preeti U Murthy <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/792d59a40423f0acffc9bb0bec9de1341a06fa02.1423788565.git.viresh.kumar@linaro.org
Signed-off-by: Ingo Molnar <[email protected]>

show more ...