The clockevents / tick management code expects an error value, when the
event is already expired. hpet_next_event() returns 1 in that case.
Fix it to return the proper -ETIME error code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
commit f9690982b8 removed the check for
cpu_khz from sched_clock(), which prevented early access to the TSC by
non obvious magic.
This is harmless as long as the CPU has a TSC. On TSCless systems this
results in an illegal instruction trap.
Replace tsc_disabled and tsc_unstable by tsc_enabled, which is only set
when the tsc is available and not unstable.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It turned out that it is almost impossible to trust ACPI, BIOS & Co.
regarding the C states. This was the reason to switch the local apic
timer off in C2 state already. OTOH there are sane and well behaving
systems, which get punished by that decision.
Allow the user to confirm that the local apic timer is trustworthy in C2
state. This keeps the default behaviour on the safe side.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
latest -git triggers an irqtrace/lockdep warning of a leaked
irqs-off condition:
BUG: at kernel/fork.c:1033 copy_process()
after some debugging it turns out that commit ca1b940c accidentally left
interrupts disabled - which trickled down all the way to the first time
we fork a kernel thread and triggered the warning.
the fix is to re-enable interrupts in the 'else' branch of
setup_boot_APIC_clock()'s pmtimers calibration path.
Reported-by: Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Thomas Gleixner <tglx@brown.paperbag.linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The local APIC timer stops to work in deeper C-States. This is handled by
the ACPI code and a broadcast mechanism in the clockevents / tick managment
code.
Some systems do not expose the deeper C-States to the kernel, but switch
into deeper C-States behind the kernels back. This delays the local apic
timer interrupts for ever and makes the systems unusable.
Add a command line option to disable the local apic timer and a dmi
quirk for known broken systems.
Andi sayeth:
While not wrong by itself i think it is still better to use some heuristic
-- like "has battery in ACPI" With the DMI table if the problem is more wide
spread we will just continue extending it.
But anyways should be ok now for .21 although I'm not really happy with
it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Grudgingly-acked-by: Andi Kleen <ak@suse.de>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The PIT has no dedicated mode for shut down. The only way to disable PIT
is to put it into one shot mode. AMD implementations of PIT on Geode
(also observed on Cyrix) are confused by an "empty" transition from
CLOCK_EVT_MODE_UNUSED to CLOCK_EVT_MODE_SHUTDOWN, which puts the PIT
into one shot mode momentarily.
I realized after staring helpless at the bug report
http://bugzilla.kernel.org/show_bug.cgi?id=8027 for quite a while, that
the only change, which might influence the bogomips calibration, is the
above transition during the PIT initialization.
Avoiding the unnecessary switch to oneshot and later to periodic mode
fixes the weird bogomips value and also the resulting slowness.
The fix is confirmed on OLPC and another Geode based box.
Note: this is unrelated to the Dual Core problem discussed here:
http://lkml.org/lkml/2007/3/17/48
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When PM-Timer is available for local APIC timer calibration we can skip the
verification of the calibrated time value. The resulting error is quite
small on a bunch of evaluated platforms and is less harming than the
observed false positives.
We need to keep the verification on systems, which have no PM-Timer to
avoid bogus local APIC timer calibrations in the range of factor 2-10,
which can be observed when swicthing off the PM-timer support in the kernel
configuration.
The wrong calibration values are probably caused by SMM code trying to
emulate a PS/2 keyboard from a (maybe connected or not) USB keyboard. This
prohibits the accurate delivery of PIT interrupts, which are used to
calibrate the local APIC timer. Unfortunately we have no way to disable
this BIOS misfeature in the early boot process.
Add also the dropped cpu_relax() back to the wait loops.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The symbol is not actually used, but the compiler unforunately generates
a (unused) reference to it. This can happen even in modules. So export it.
Signed-off-by: Andi Kleen <ak@suse.de>
VMI ROMs are pretty intimate to the kernel, so enforce their GPLness.
No \0 tricks checking for now
This rules out BSD/MIT modules for now, sorry -- the trouble is those
could come without source.
Acked-by: Zachary Amsden <zach@vmware.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andi Kleen <ak@suse.de>
x86_64 nvidia_bugs() broke when we bailed out on not finding the HPET.
However, the quirk works by checking for _not_ finding the HPET...
Delete the nvidia_hpet_detected flag and simply test for
not finding the HPET, which is simple to do now that
acpi_table_parse returns 1 on failure.
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The root cause of this bug shows that this machine
could not possibly run an ACPI-aware OS without a
model specific workaround.
http://bugzilla.kernel.org/show_bug.cgi?id=5966
Signed-off-by: Len Brown <len.brown@intel.com>
check_tsc_sync_source() depends on being called with irqs disabled (it
checks whether the TSC is coherent across two specific CPUs). This is
incidentally true during bootup, but not during cpu hotplug __cpu_up().
This got found via smp_processor_id() debugging.
disable irqs explicitly and remove the unconditional enabling of
interrupts. Add touch_nmi_watchdog() to the cpu_online_map busy loop.
this bug is present both on i386 and on x86_64.
Reported-by: Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The obsolete SA_xxx interrupt flags have been used despite the scheduled
removal. Fixup the remaining users.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CC arch/i386/kernel/vmi.o
/home/bunk/linux/kernel-2.6/linux-2.6.21-rc2-mm1/arch/i386/kernel/vmi.c: In function 'vmi_map_pt_hook':
/home/bunk/linux/kernel-2.6/linux-2.6.21-rc2-mm1/arch/i386/kernel/vmi.c:387: error: 'KM_PTE0' undeclared (first use in this function)
/home/bunk/linux/kernel-2.6/linux-2.6.21-rc2-mm1/arch/i386/kernel/vmi.c:387: error: (Each undeclared identifier is reported only once
/home/bunk/linux/kernel-2.6/linux-2.6.21-rc2-mm1/arch/i386/kernel/vmi.c:387: error: for each function it appears in.)
/home/bunk/linux/kernel-2.6/linux-2.6.21-rc2-mm1/arch/i386/kernel/vmi.c:387: error: 'KM_PTE1' undeclared (first use in this function)
make[2]: *** [arch/i386/kernel/vmi.o] Error 1
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus 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: 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>
Testing NMI watchdog ... CPU#0: NMI appears to be stuck (54->54)!
CPU#1: NMI appears to be stuck (0->0)!
Keep the PIT/HPET alive when nmi_watchdog = 1 is given on the command
line.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Critical fixes for SMP.
Fix a couple functions which needed to be __devinit and fix a bogus parameter
to AP startup that just so happened to work because the low virtual mapping of
memory was still established.
Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use para_fill instead of directly setting the APIC ops to the result of the
vmi_get_function call - this allows one to implement a VMI ROM without
implementing APIC functions, just using the native APIC functions.
While doing this, I realized that there is a lot more cleanup that should have
been done. Basically, we should never assume that the ROM implements a
specific set of functions, and always allow fallback to the native
implementation.
This is critical for future compatibility.
Signed-off-by: Anthony Liguori <anthony@codemonkey.ws>
Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
More goo from hrtimers integration. We do compile and run properly with NO_HZ
enabled. There was a period when we didn't because of a missing export, but
that was since fixed.
And with the clocksource code now firmly in place, we can get rid of code that
fixes up the wallclock, since this is done in the common infrastructure. This
actually fixes a timer bug as well, that was caused by do_settimeofday no
longer being callable with interrupts disabled due to the use of
on_each_cpu().
Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The time_init_hook in paravirt-ops no longer functions in the correct manner
after the integration of the hrtimers code. The problem is that now the call
path for time initialization is:
time_init :
late_time_init = hpet_time_init;
late_time_init -> hpet_time_init:
setup_pit_timer (BAD)
do_time_init --> (via paravirt.h)
time_init_hook --> (via arch_hooks.h)
time_init_hook (in SUBARCH/setup.c)
If this isn't confusing enough, the paravirt case goes through an indirect
function pointer in the paravirt-ops table. The problem is, by the time the
paravirt hook is called, the pit timer is already enabled.
But paravirt guests have their own timer, and don't want to use the PIT.
Rather than intensify the struggle for power going on here, just make it all
nice and simple and just unconditionally do all timer setup in the
late_time_init hook. This also has the advantage of enabling timers in the
same place in all code paths, so everyone has the same bugs and we don't have
outliers who break other code because they turn on timer too early or too
late.
So the paravirt-ops time init function is now by default hpet_time_init, which
is the time init function used for native hardware. Paravirt guests have the
chance to override this when they setup the paravirt-ops table, and should
need no change.
Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Not respecting udelay causes problems with any virtual hardware that is passed
through to real hardware. This can be noticed by any device that interacts
with the real world in real time - like AP startup, which takes real time. Or
keyboard LEDs, which should blink in real-time. Or floppy drives, but only
when passed through to a real floppy controller on OSes which can't
sufficiently buffer the floppy commands to emulate a zero latency floppy. Or
IDE drives, when connecting to a physical CDROM.
This was mostly a hack to get the kernel to boot faster, but it introduced a
number of misvirtualization bugs, and Alan and Pavel argued pretty strongly
against it. We were the only client, and now want to clean up this cruft.
Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Provide a PT map hook for HIGHPTE kernels to designate where they are mapping
page tables. This information is required so the physical address of PTE
updates can be determined; otherwise, the mm layer would have to carry the
physical address all the way to each PTE modification callsite, which is even
more hideous that the macros required to provide the proper hooks.
So lets not mess up arch neutral code to achieve this, but keep the horror in
an #ifdef HIGHPTE in include/asm-i386/pgtable.h. I had to use macros here
because some types are not yet defined in all the include paths for this
header.
This patch is absolutely required for HIGHPTE kernels to operate properly with
VMI.
Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In order to share the common code in tsc.c which does CPU Khz calibration, we
need to make an accurate value of CPU speed available to the tsc.c code. This
value loses a lot of precision in a VM because of the timing differences with
real hardware, but we need it to be as precise as possible so the guest can
make accurate time calculations with the cycle counters.
Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The custom_sched_clock hook is broken. The result from sched_clock needs to
be in nanoseconds, not in CPU cycles. The TSC is insufficient for this
purpose, because TSC is poorly defined in a virtual environment, and mostly
represents real world time instead of scheduled process time (which can be
interrupted without notice when a virtual machine is descheduled).
To make the scheduler consistent, we must expose a different nature of time,
that is scheduled time. So deprecate this custom_sched_clock hack and turn it
into a paravirt-op, as it should have been all along. This allows the tsc.c
code which converts cycles to nanoseconds to be shared by all paravirt-ops
backends.
It is unfortunate to add a new paravirt-op, but this is a very distinct
abstraction which is clearly different for all virtual machine
implementations, and it gets rid of an ugly indirect function which I
ashamedly admit I hacked in to try to get this to work earlier, and then even
got in the wrong units.
Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Critical bugfixes for the VMI-Timer code.
1) Do not setup a one shot alarm if we are keeping the periodic alarm
armed. Additionally, since the periodic alarm can be run at a lower rate
than HZ, let's fixup the guard to the no-idle-hz mode appropriately. This
fixes the bug where the no-idle-hz mode might have a higher interrupt rate
than the non-idle case.
2) The interrupt handler can no longer adjust xtime due to nested lock
acquisition. Drop this. We don't need to check for wallclock time at
every tick, it can be done in userspace instead.
3) Add a bypass to disable noidle operation. This is useful as a last
minute workaround, or testing measure.
4) The code to skip the IO_APIC timer testing (no_timer_check) should be
conditional on IO_APIC, not SMP, since UP kernels can have this configured
in as well.
Signed-off-by: Dan Hecht <dhecht@vmware.com>
Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When it goes to free1_out, dev->dma_mem has not been freed.
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When removing set_native_irq I missed the fact that it was
called in a couple of places that were compiled even when
SMP support is disabled. And since the irq_desc[].affinity
field only exists in SMP things broke.
Thanks to Simon Arlott <simon@arlott.org> for spotting this.
There are a couple of ways to fix this but the simplest one
is to just remove the assignments. The affinity field is only
used to display a value to the user, and nothing on either i386
or x86_64 reads it or depends on it being any particlua value,
so skipping the assignment is safe. The assignment that
is being removed is just for the initial affinity value before
the user explicitly sets it. The irq_desc array initializes
this field to CPU_MASK_ALL so the field is initialized to
a reasonable value in the SMP case without being set.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit aeeddc1435, which was
half-baked and broken. It just resulted in compile errors, since
cpufreq_register_driver() still changes the 'driver_data' by setting
bits in the flags field. So claiming it is 'const' _really_ doesn't
work.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch replaces all instances of "set_native_irq_info(irq, mask)"
with "irq_desc[irq].affinity = mask". The latter form is clearer
uses fewer abstractions, and makes access to this field uniform
accross different architectures.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 2ff2d3d747.
Uwe Bugla reports that he cannot mount a floppy drive any more, and Jiri
Slaby bisected it down to this commit.
Benjamin LaHaise also points out that this is a big hot-path, and that
interrupt delivery while idle is very common and should not go through
all these expensive gyrations.
Fix up conflicts in arch/i386/kernel/apic.c and arch/i386/kernel/irq.c
due to other unrelated irq changes.
Cc: Stephane Eranian <eranian@hpl.hp.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Andrew Morton <akpm@osdl.org>
Cc: Uwe Bugla <uwe.bugla@gmx.de>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial: (25 commits)
Documentation/kernel-docs.txt update.
arch/cris: typo in KERN_INFO
Storage class should be before const qualifier
kernel/printk.c: comment fix
update I/O sched Kconfig help texts - CFQ is now default, not AS.
Remove duplicate listing of Cris arch from README
kbuild: more doc. cleanups
doc: make doc. for maxcpus= more visible
drivers/net/eexpress.c: remove duplicate comment
add a help text for BLK_DEV_GENERIC
correct a dead URL in the IP_MULTICAST help text
fix the BAYCOM_SER_HDX help text
fix SCSI_SCAN_ASYNC help text
trivial documentation patch for platform.txt
Fix typos concerning hierarchy
Fix comment typo "spin_lock_irqrestore".
Fix misspellings of "agressive".
drivers/scsi/a100u2w.c: trivial typo patch
Correct trivial typo in log2.h.
Remove useless FIND_FIRST_BIT() macro from cardbus.c.
...
Now that disable_irq() defaults to delayed-disable semantics, the IRQ_DISABLED
flag is not needed anymore.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Never mask interrupts immediately upon request. Disabling interrupts in
high-performance codepaths is rare, and on the other hand this change could
recover lost edges (or even other types of lost interrupts) by conservatively
only masking interrupts after they happen. (NOTE: with this change the
highlevel irq-disable code still soft-disables this IRQ line - and if such an
interrupt happens then the IRQ flow handler keeps the IRQ masked.)
Mark i8529A controllers as 'never loses an edge'.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In preparation for supporting generic timekeeping, this patch cleans up
x86-64's use of vxtime.hpet_address, changing it to just hpet_address as is
also used in i386. This is necessary since the vxtime structure will be going
away.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@muc.de>
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>
The NMI watchdog implementation assumes that the local APIC timer interrupt is
happening. This assumption is not longer true when high resolution timers and
dynamic ticks come into play, as they may switch off the local APIC timer
completely. Take the PIT/HPET interrupts into account too, to avoid false
positives.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Andi Kleen <ak@suse.de>
Cc: Zachary Amsden <zach@vmware.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rohit Seth <rohitseth@google.com>
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>
The local apic timer calibration has two problem cases:
1. The calibration is based on readout of the PIT/HPET timer to detect the
wrap of the periodic tick. It happens that a box gets stuck in the
calibration loop due to a PIT with a broken readout function.
2. CoreDuo boxen show a sporadic PIT runs too slow defect, which results
in a wrong lapic calibration. The PIT goes back to normal operation once
the lapic timer is switched to periodic mode.
Both are existing and unfixed problems in the current upstream kernel and
prevent certain laptops and other systems from booting Linux.
Rework the code to address both problems:
- Make the calibration interrupt driven. This removes the wait_timer_tick
magic hackery from lapic.c and time_hpet.c. The clockevents framework
allows easy substitution of the global tick event handler for the
calibration. This is more accurate than monitoring jiffies. At this point
of the boot process, nothing disturbes the interrupt delivery, so the
results are very accurate.
- Verify the calibration against the PM timer, when available by using the
early access function. When the measured calibration period is outside of
an one percent window, then the lapic timer calibration is adjusted to the
pm timer result.
- Verify the calibration by running the lapic timer with the calibration
handler. Disable lapic timer in case of deviation.
This also removes the "synchronization" of the local apic timer to the global
tick. This synchronization never worked, as there is no way to synchronize
PIT(HPET) and local APIC timer. The synchronization by waiting for the tick
just alignes the local APIC timer for the first events, but later the events
drift away due to the different clocks. Removing the "sync" is just
randomizing the asynchronous behaviour at setup time.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Zachary Amsden <zach@vmware.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rohit Seth <rohitseth@google.com>
Cc: Andi Kleen <ak@suse.de>
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>
Add clockevent drivers for i386: lapic (local) and PIT/HPET (global). Update
the timer IRQ to call into the PIT/HPET driver's event handler and the
lapic-timer IRQ to call into the lapic clockevent driver. The assignement of
timer functionality is delegated to the core framework code and replaces the
compile and runtime evalution in do_timer_interrupt_hook()
Use the clockevents broadcast support and implement the lapic_broadcast
function for ACPI.
No changes to existing functionality.
[ kdump fix from Vivek Goyal <vgoyal@in.ibm.com> ]
[ fixes based on review feedback from Arjan van de Ven <arjan@infradead.org> ]
Cleanups-from: Adrian Bunk <bunk@stusta.de>
Build-fixes-from: Andrew Morton <akpm@osdl.org>
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>
