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On systems with two or fewer sockets, when the boot CPU has CONSTANT_TSC,
NONSTOP_TSC, and TSC_ADJUST, clocksource watchdog verification of the
TSC is disabled. This works well much of the time, but there is the
occasional production-level system that meets all of these criteria, but
which still has a TSC that skews significantly from atomic-clock time.
This is usually attributed to a firmware or hardware fault. Yes, the
various NTP daemons do express their opinions of userspace-to-atomic-clock
time skew, but they put them in various places, depending on the daemon
and distro in question. It would therefore be good for the kernel to
have some clue that there is a problem.
The old behavior of marking the TSC unstable is a non-starter because a
great many workloads simply cannot tolerate the overheads and latencies
of the various non-TSC clocksources. In addition, NTP-corrected systems
sometimes can tolerate significant kernel-space time skew as long as
the userspace time sources are within epsilon of atomic-clock time.
Therefore, when watchdog verification of TSC is disabled, enable it for
HPET and PMTMR (AKA ACPI PM timer). This provides the needed in-kernel
time-skew diagnostic without degrading the system's performance.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Waiman Long <longman@redhat.com>
Cc: <x86@kernel.org>
Tested-by: Feng Tang <feng.tang@intel.com>
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__setup() handlers should return 1 to obsolete_checksetup() in
init/main.c to indicate that the boot option has been handled.
A return of 0 causes the boot option/value to be listed as an Unknown
kernel parameter and added to init's (limited) environment strings.
The __setup() handler interface isn't meant to handle negative return
values -- they are non-zero, so they mean "handled" (like a return
value of 1 does), but that's just a quirk. So return 1 from
parse_pmtmr(). Also print a warning message if kstrtouint() returns
an error.
Fixes: 6b148507d3d0 ("pmtmr: allow command line override of ioport")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru>
Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Based on 1 normalized pattern(s):
this file is licensed under the gpl v2
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 3 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204654.634736654@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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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>
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Like it's already done in one place in the driver, convert the rest to use pr_*
macros instead of printk(KERN_LEVEL) calls.
While here, join strings to be one string for one line to make grep on them
easier.
There is no functional change.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: http://lkml.kernel.org/r/1451310085-113182-1-git-send-email-andriy.shevchenko@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Using 0x%# emits 0x0x. Only one is necessary.
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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CONFIG_HOTPLUG is going away as an option. As a result, the __dev*
markings need to be removed.
This change removes the use of __devinit, __devexit_p, __devinitdata,
__devinitconst, and __devexit from these drivers.
Based on patches originally written by Bill Pemberton, but redone by me
in order to handle some of the coding style issues better, by hand.
Cc: Bill Pemberton <wfp5p@virginia.edu>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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I changed the strict_strtoul() to kstrtouint(). That has the check
for UINT_MAX built in to it so the ifdefs can be removed. Also
I changed a printk() to pr_info().
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
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This reverts commit b519508298e0292e1771eecf14aaf67755adc39d.
The reason for this revert is that making the frequency verification
preemptible and interruptible is not working reliably. Michaels
machine failed to use PM-timer with the message:
PM-Timer running at invalid rate: 113% of normal - aborting.
That's not a surprise as the frequency verification does rely on
interrupts being disabled. With a async scheduled thread there is no
guarantee to achieve the same result. Also some driver might fiddle
with the CTC channel 2 during the verification period, which makes the
result even more random and unpredictable.
This can be solved by using the same mechanism as we use in the
deferred TSC validation code, but that only will work if we verified a
working HPET _BEFORE_ trying to do the PM-Timer lazy validation.
So for now reverting is the safe option.
Bisected-by: Michael Witten <mfwitten@gmail.com>
Cc: Arjan van de Ven <arjanvandeven@gmail.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Len Brown <lenb@kernel.org>
LKML-Reference: <alpine.LFD.2.02.1204112303270.2542@ionos>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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The ACPI clocksource takes quite some time to initialize,
and this increases the boot time of the kernel for a
double digit percentage. This while almost all modern
systems will be using the HPET already anyway.
This patch turns the clocksource loading into an asynchronous
operation; which means it won't hold up the boot while
still becoming available normally.
To make this work well, an udelay() had to be turned into an
usleep_range() so that on UP systems, we yield the CPU to
regular boot tasks instead of spinning.
CC: John Stultz <johnstul@us.ibm.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Len Brown <lenb@kernel.org>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
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The acpi_pm clocksource driver uses CLOCK_TICK_RATE which is
defined as PIT_TICK_RATE on x86. This patch cleans it up to
just use the later so that CLOCK_TICK_RATE can be depecrated.
Signed-off-by: Deepak Saxena <dsaxena@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
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If the acpi pm timer throws invalid data, clear pmtmr_ioport
so the pm timer won't accidentally be used.
This was found when using Xen where there is a acpi pm reported,
but gives bogus values, and other code was continuing to try
to use the pm timer after the initialization failed.
[jstultz: Catch additional failure and reword changelog message. ]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: John Stultz <johnstul@us.ibm.com>
LKML-Reference: <1295027246-11110-1-git-send-email-johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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This converts the most common of the x86 clocksources over to use
clocksource_register_hz/khz.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
LKML-Reference: <1279068988-21864-11-git-send-email-johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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PIT_TICK_RATE is currently defined in four architectures, but in three
different places. While linux/timex.h is not the perfect place for it, it
is still a reasonable replacement for those drivers that traditionally use
asm/timex.h to get CLOCK_TICK_RATE and expect it to be the PIT frequency.
Note that for Alpha, the actual value changed from 1193182UL to 1193180UL.
This is unlikely to make a difference, and probably can only improve
accuracy. There was a discussion on the correct value of CLOCK_TICK_RATE
a few years ago, after which every existing instance was getting changed
to 1193182. According to the specification, it should be
1193181.818181...
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Len Brown <lenb@kernel.org>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Dmitry Torokhov <dtor@mail.ru>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Pass clocksource pointer to the read() callback for clocksources. This
allows us to share the callback between multiple instances.
[hugh@veritas.com: fix powerpc build of clocksource pass clocksource mods]
[akpm@linux-foundation.org: cleanup]
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Acked-by: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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We are getting rid of subarchitecture support - move the hook files
to asm/. (These are now stale and should be replaced with more explicit
runtime mechanisms - but the transition is simpler this way.)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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acpi_pm_read_slow() is only used when CONFIG_PCI=y, so move the definition
inside the ifdef.
Otherwise this causes a "defined but not used" warning when building with
CONFIG_ACPI=y and CONFIG_PCI=n (that's not supported yet, but it could
be).
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: mingo@elte.hu
Cc: johnstul@us.ibm.com
Cc: akpm@linux-foundation.org
Cc: bjorn.helgaas@hp.com
Cc: lenb@kernel.org
Cc: linux@dominikbrodowski.net
Cc: tglx@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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'timers/ntp', 'timers/posixtimers' and 'timers/debug' into v28-timers-for-linus
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Actually check the monotonicity of the ACPI PMTMR ten times, only delay for
0.9 miliseconds at most, and bail out early if some problem is determined.
Reported-by: Jochen Voß <jochen.voss@googlemail.com>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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The current check for monotonicity is way too weak: Andreas Mohr reports (
http://lkml.org/lkml/2008/8/10/77 ) that on one of his test systems the
current check only triggers in 50% of all cases, leading to catastrophic
timer behaviour. To fix this issue, expand the check for monotonicity by
doing ten consecutive tests instead of one.
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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On all hardware (some Intel ICH4, PIIX4 and PIIX4E chipsets) affected by a
hardware errata there's about a 4.2% chance that initialization of the
ACPI PMTMR fails. On those chipsets, we need to read out the timer value
at least three times to get a correct result, for every once in a while
(i.e. within a 3 ns window every 69.8 ns) the read returns a bogus
result. During normal operation we work around this issue, but during
initialization reading a bogus value may lead to -EINVAL even though the
hardware is usable.
Thanks to Andreas Mohr for spotting this issue.
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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Check that the value being passed to parse_pmtmr() does not exceed the
limits of pmtmr_ioport.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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For real, this time. The earlier attempt just moved the warning around.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Fix printk format warning in acpi_pm clocksource:
linux-next-20080711/drivers/clocksource/acpi_pm.c:231: warning: format '%04lx' expects type 'long unsigned int', but argument 2 has type 'u32'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: akpm <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Stupid BIOSes do not tell us about the PMTimer,
but we might know where it is.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Signed-off-by: Alessio Igor Bogani <abogani@texware.it>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Instead of all drivers reading pci config space to get the revision
ID, they can now use the pci_device->revision member.
This exposes some issues where drivers where reading a word or a dword
for the revision number, and adding useless error-handling around the
read. Some drivers even just read it for no purpose of all.
In devices where the revision ID is being copied over and used in what
appears to be the equivalent of hotpath, I have left the copy code
and the cached copy as not to influence the driver's performance.
Compile tested with make all{yes,mod}config on x86_64 and i386.
Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>
Acked-by: Dave Jones <davej@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Signed-off-by: Daniel Walker <dwalker@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
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On Bob's machine clocksource is selecting PIT over the ACPI PM timer,
because he has the PIIX4 bug. That bug drops the ACPI PM timers rating
to the same as the PIT, so that's why you're getting the PIT.
Realistically, the PIT is much slower then even the triple read ACPI PM,
so the de-ranking code is probably dropping it too far.
So don't drop ACPI PM quite so low if we see the PIIX4 bug.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Bob Tracy <rct@gherkin.frus.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This patch resolves the issue found here:
http://bugme.osdl.org/show_bug.cgi?id=7426
The basic summary is:
Currently we register most of i386/x86_64 clocksources at module_init
time. Then we enable clocksource selection at late_initcall time. This
causes some problems for drivers that use gettimeofday for init
calibration routines (specifically the es1968 driver in this case),
where durring module_init, the only clocksource available is the low-res
jiffies clocksource. This may cause slight calibration errors, due to
the small sampling time used.
It should be noted that drivers that require fine grained time may not
function on architectures that do not have better then jiffies
resolution timekeeping (there are a few). However, this does not
discount the reasonable need for such fine-grained timekeeping at init
time.
Thus the solution here is to register clocksources earlier (ideally when
the hardware is being initialized), and then we enable clocksource
selection at fs_initcall (before device_initcall).
This patch should probably get some testing time in -mm, since
clocksource selection is one of the most important issues for correct
timekeeping, and I've only been able to test this on a few of my own
boxes.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Allow early access to the power management timer by exposing the verified read
function and providing a helper function which checks the pmtmr_ioport
variable and returns either the pm timer readout or 0 in case the pm timer is
not available.
Create a new header file and replace also the ifdef'ed extern definition in
arch/i386/kernel/acpi/boot.c
This is a preperatory patch for the rework of the local apic timer
calibration.
No functional changes.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Using a flag filed allows to encode more than one information into a variable.
Preparatory patch for the generic clocksource verification.
[mingo@elte.hu: convert vmitime.c to the new clocksource flag]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Mostly changing alignment. Just some general cleanup.
[akpm@osdl.org: build fix]
Signed-off-by: Daniel Walker <dwalker@mvista.com>
Acked-by: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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This patch re-adds the verify_pmtmr_rate functionality from 2.6.17 that
I dropped 2.6.18.
This resolves problems seen on older K6 ASUS boards where the ACPI PM
timer runs too fast.
See:
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=211902
http://bugme.osdl.org/show_bug.cgi?id=2375
Thanks to Ian Campbell for re-reporting this and testing the fix!
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Ian Campbell <ijc@hellion.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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I have an acpi_pm that goes backwards, but it's not intel. I tested the
verified read and my acpi_pm started to function properly. So I added it
to the greylist. I'm assuming that's the right spot.
I also added an unlikely() to the while, cause it seems appropriate.
Signed-off-by: Daniel Walker <dwalker@mvista.com>
Acked-by: John Stultz <johnstul@us.ibm.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Add a CLOCKSOURCE_MASK macro to simplify initializing the mask for a struct
clocksource, and use it to replace literal mask constants in the various
clocksource drivers.
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Acked-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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- written on init only, accessed for every timer read --> __read_mostly
- fix broken sentence
Signed-off-by: Andreas Mohr <andi@lisas.de>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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As suggested by Roman Zippel, change clocksource functions to use
clocksource_xyz rather then xyz_clocksource to avoid polluting the
namespace.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Implement the time sources for i386 (acpi_pm, cyclone, hpet, pit, and tsc).
With this patch, the conversion of the i386 arch to the generic timekeeping
code should be complete.
The patch should be fairly straight forward, only adding the new clocksources.
[hirofumi@mail.parknet.co.jp: acpi_pm cleanup]
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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