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: NJochen Voß <jochen.voss@googlemail.com>
Signed-off-by: NDominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

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: NDominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

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: NDominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

For real, this time.  The earlier attempt just moved the warning around.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NRandy Dunlap <randy.dunlap@oracle.com>
Cc: akpm <akpm@linux-foundation.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Stupid BIOSes do not tell us about the PMTimer, 
but we might know where it is.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Signed-off-by: NAlessio Igor Bogani <abogani@texware.it>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NAuke Kok <auke-jan.h.kok@intel.com>
Acked-by: NDave Jones <davej@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Signed-off-by: NDaniel Walker <dwalker@mvista.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLen Brown <len.brown@intel.com>

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: NJohn 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: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NJohn 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: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo 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: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Mostly changing alignment.  Just some general cleanup.

[akpm@osdl.org: build fix]
Signed-off-by: NDaniel Walker <dwalker@mvista.com>
Acked-by: NJohn Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

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: NJohn 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: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

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: NDaniel Walker <dwalker@mvista.com>
Acked-by: NJohn Stultz <johnstul@us.ibm.com>
Acked-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

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: NJim Cromie <jim.cromie@gmail.com>
Acked-by: NJohn Stultz <johnstul@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

- written on init only, accessed for every timer read --> __read_mostly
- fix broken sentence
Signed-off-by: NAndreas Mohr <andi@lisas.de>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

As suggested by Roman Zippel, change clocksource functions to use
clocksource_xyz rather then xyz_clocksource to avoid polluting the
namespace.
Signed-off-by: NJohn Stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

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: NJohn Stultz <johnstul@us.ibm.com>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>
Signed-off-by: NJohn Stultz <johnstul@us.ibm.com>
Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>