This is the x86-64 version of f9dadfa71b
that did the same thing on i386.
Since the "mask" bit is in the low word, when we write a new entry, we
need to write the high word first, before we potentially unmask it.
The exception is when we actually want to mask the interrupt, in which
case we want to write the low word first to make sure that the high word
doesn't change while the interrupt routing is still active.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This is just commit 130fe05dbc ported to
x86-64, for all the same reasons. It cleans up the IO-APIC accesses in
order to then fix the ordering issues.
We move the accessor functions (that were only used by io_apic.c) out of
a header file, and use proper memory-mapped accesses rather than making
up our own "volatile" pointers.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When I generalized __assign_irq_vector I failed to pay attention
to what happens when you access a per cpu data structure for
a cpu that is not online. It is an undefined case making any
code that does it have undefined behavior as well.
The code still needs to be able to allocate a vector across cpus
that are not online to properly handle combinations like lowest
priority interrupt delivery and cpu_hotplug. Not that we can do
that today but the infrastructure shouldn't prevent it.
So this patch updates the places where we touch per cpu data
to only touch online cpus, it makes cpu vector allocation
an atomic operation with respect to cpu hotplug, and it updates
the cpu start code to properly initialize vector_irq so we
don't have inconsistencies.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andi Kleen <ak@suse.de>
There is no reason to remember a per cpu position of which vector
to try. Keeping a global position is simpler and more likely to
result in a global vector allocation even if I don't need or require
it. For level triggered interrupts this means we are less likely to
acknowledge another cpus irq, and cause the level triggered irq to
harmlessly refire.
This simplification makes it easier to only access data structures
of online cpus, by having fewer special cases to deal with.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andi Kleen <ak@suse.de>
By default route the 8254 over the 8259 and only disable
it on ATI boards where this causes double timer interrupts.
This should unbreak some Nvidia boards where the timer doesn't
seem to tick of it isn't enabled in the 8259. At least one
VIA board also seemed to have a little trouble with the disabled
8259.
For 2.6.20 we'll try both dynamically without black listing, but I think
for .19 this is the safer approach because it has been already well tested
in earlier kernels. This also makes the x86-64 behaviour the same
as i386.
Command line options can change all this of course.
Signed-off-by: Andi Kleen <ak@suse.de>
Thanks to YH Lu for spotting this. It appears I missed this function when I
refactored allocate_irq_vector and introduced irq_domain, with the result that
all retriggered irqs would go to cpu 0 even if we were not prepared to receive
them there.
While reviewing YH's patch I also noticed that this function was missing
locking, and since I am now reading two values from two diffrent arrays that
looks like a race we might be able to hit in the real world.
Cc: Yinghai Lu <yinghai.lu@amd.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Introduce desc->name and eliminate the handle_irq_name() hack. Add
set_irq_chip_and_handler_name() to set the flow type and name at once.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Matthew Wilcox <willy@debian.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch fixes my one line thinko where I was clearing
the vector_irq entries on the wrong cpus.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
hw_interrupt_type is deprecated in favour of struct irq_chip.
[mingo@elte.hu: do x86_64 too]
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The problem we can't take advantage of lowest priority delivery mode if
the vectors are allocated for only one cpu at a time. Nor can we work
around hardware that assumes lowest priority delivery mode is always
used with several cpus.
So this patch introduces the concept of a vector_allocation_domain. A
set of cpus that will receive an irq on the same vector. Currently the
code for implementing this is placed in the genapic structure so we can
vary this depending on how we are using the io_apics.
This allows us to restore the previous behaviour of genapic_flat without
removing the benefits of having separate vector allocation for large
machines.
This should also fix the problem report where a hyperthreaded cpu was
receving the irq on the wrong hyperthread when in logical delivery mode
because the previous behaviour is restored.
This patch properly records our allocation of the first 16 irqs to the
first 16 available vectors on all cpus. This should be fine but it may
run into problems with multiple interrupts at the same interrupt level.
Except for some badly maintained comments in the code and the behaviour
of the interrupt allocator I have no real understanding of that problem.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Muli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Which vector an irq is assigned to now varies dynamically and is
not needed outside of io_apic.c. So remove the possibility
of accessing the information outside of io_apic.c and remove
the silly macro that makes looking for users of irq_vector
difficult.
The fact this compiles ensures there aren't any more pieces
of the old CONFIG_PCI_MSI weirdness that I failed to remove.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This moves the declarations for the architecture helpers into
include/linux/htirq.h from the generic include/linux/pci.h. Hopefully this
will make this distinction clearer.
htirq.h is included where it is needed.
The dependency on the msi code is fixed and removed.
The Makefile is tidied up.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg KH <greg@kroah.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It turns out msi_ops was simply not enough to abstract the architecture
specific details of msi. So I have moved the resposibility of constructing
the struct irq_chip to the architectures, and have two architecture specific
functions arch_setup_msi_irq, and arch_teardown_msi_irq.
For simple architectures those functions can do all of the work. For
architectures with platform dependencies they can call into the appropriate
platform code.
With this msi.c is finally free of assuming you have an apic, and this
actually takes less code.
The helpers for the architecture specific code are declared in the linux/msi.h
to keep them separate from the msi functions used by drivers in linux/pci.h
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg KH <greg@kroah.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch implements two functions ht_create_irq and ht_destroy_irq for
use by drivers. Several other functions are implemented as helpers for
arch specific irq_chip handlers.
The driver for the card I tested this on isn't yet ready to be merged.
However this code is and hypertransport irqs are in use in a few other
places in the kernel. Not that any of this will get merged before 2.6.19
Because the ipath-ht400 is slightly out of spec this code will need to be
generalized to work there.
I think all of the powerpc uses are for a plain interrupt controller in a
chipset so support for native hypertransport devices is a little less
interesting.
However I think this is a half way decent model on how to separate arch
specific and generic helper code, and I think this is a functional model of
how to get the architecture dependencies out of the msi code.
[akpm@osdl.org: Kconfig fix]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Greg KH <greg@kroah.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
With more irqs in the system we don't need this.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
After raising the number of irqs the system supports this function is no
longer necessary.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This refactors the irq handling code to make the vectors a per cpu resource so
the same vector number can be simultaneously used on multiple cpus for
different irqs.
This should make systems that were hitting limits on the total number of irqs
much more livable.
[akpm@osdl.org: build fix]
[akpm@osdl.org: __target_IO_APIC_irq is unneeded on UP]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This is a small pessimization but it paves the way for making this information
per cpu. Which allows the the maximum number of IRQS to become NR_CPUS*224.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch removes the change in behavior of the irq allocation code when
CONFIG_PCI_MSI is defined. Removing all instances of the assumption that irq
== vector.
create_irq is rewritten to first allocate a free irq and then to assign that
irq a vector.
assign_irq_vector is made static and the AUTO_ASSIGN case which allocates an
vector not bound to an irq is removed.
The ioapic vector methods are removed, and everything now works with irqs.
The definition of NR_IRQS no longer depends on CONFIG_PCI_MSI
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This removes the hardcoded assumption that irq == vector in the msi
composition code, and it allows the msi message composition to setup logical
mode, or lowest priorirty delivery mode as we do for other apic interrupts,
and with the same selection criteria.
Basically this moves the problem of what is in the msi message into the
architecture irq management code where it belongs. Not in a generic layer
that doesn't have enough information to compose msi messages properly.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The current implementation of create_irq() is a hack but it is the current
hack that msi.c uses, and unfortunately the ``generic'' apic msi ops depend on
this hack. Thus we are this hack of assuming irq == vector until the
depencencies in the generic irq code are removed.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In the latest changes the code for migrating x86_64 irqs was dropped. This
reads it in a fashion that will work even if we change the vector on level
triggered irqs when we migrate them.
[akpm@osdl.org: build fix]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch converts all the x86_64 PIC controllers layers to the new and
simpler irq-chip interrupt handling layer.
[mingo@elte.hu: The patch also enables the fasteoi handler for x86_64]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Roland Dreier <rolandd@cisco.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
ACPI went to great trouble to get the APIC version and CPU capabilities
of different CPUs before passing them to the mpparser. But all
that data was used was to print it out. Actually it even faked some data
based on the boot cpu, not on the actual CPU being booted.
Remove all this code because it's not needed.
Cc: len.brown@intel.com
Signed-off-by: Andi Kleen <ak@suse.de>
Instead of hackish manual parsing
Requires earlier i386 patchkit, but also fixes i386 early_printk again.
I removed some obsolete really early parameters which didn't do anything useful.
Also made a few parameters that needed it early (mostly oops printing setup)
Also removed one panic check that wasn't visible without
early console anyways (the early console is now initialized after that
panic)
This cleans up a lot of code.
Signed-off-by: Andi Kleen <ak@suse.de>
They did not really belong into io_apic.c. Move them into a new file
and clean it up a bit.
Also remove outdated ATI quirk that was obsolete,
Signed-off-by: Andi Kleen <ak@suse.de>
The MPS table specification says that the operating system should
renumber the IO-APICs following the table as needed. However in
ACPI this is not allowed or neeeded and all x86-64 systems are ACPI
compliant.
The code was already disabled on some systems because it caused
problems there. Remove it completely now.
CC: mdomsch@dell.com
Signed-off-by: Andi Kleen <ak@suse.de>
The IO APIC code had lots of duplicated code to read/write 64bit
routing entries into the IO-APIC. Factor this out int common read/write
functions
In a few cases the IO APIC lock is taken more often now, but this
isn't a problem because it's all initialization/shutdown only
slow path code.
Signed-off-by: Andi Kleen <ak@suse.de>
No 64bit EISA or Microchannel systems ever. Remove the left over code
in the IO-APIC driver and the mptable parser
Signed-off-by: Andi Kleen <ak@suse.de>
This was an old workaround for broken MP-BIOS. The user could
specify overwrites on the command line.
I've never seen it being used for anything on 64bit. So get
rid of it for now.
Signed-off-by: Andi Kleen <ak@suse.de>
Add ->retrigger() irq op to consolidate hw_irq_resend() implementations.
(Most architectures had it defined to NOP anyway.)
NOTE: ia64 needs testing. i386 and x86_64 tested.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch-queue improves the generic IRQ layer to be truly generic, by adding
various abstractions and features to it, without impacting existing
functionality.
While the queue can be best described as "fix and improve everything in the
generic IRQ layer that we could think of", and thus it consists of many
smaller features and lots of cleanups, the one feature that stands out most is
the new 'irq chip' abstraction.
The irq-chip abstraction is about describing and coding and IRQ controller
driver by mapping its raw hardware capabilities [and quirks, if needed] in a
straightforward way, without having to think about "IRQ flow"
(level/edge/etc.) type of details.
This stands in contrast with the current 'irq-type' model of genirq
architectures, which 'mixes' raw hardware capabilities with 'flow' details.
The patchset supports both types of irq controller designs at once, and
converts i386 and x86_64 to the new irq-chip design.
As a bonus side-effect of the irq-chip approach, chained interrupt controllers
(master/slave PIC constructs, etc.) are now supported by design as well.
The end result of this patchset intends to be simpler architecture-level code
and more consolidation between architectures.
We reused many bits of code and many concepts from Russell King's ARM IRQ
layer, the merging of which was one of the motivations for this patchset.
This patch:
rename desc->handler to desc->chip.
Originally i did not want to do this, because it's a big patch. But having
both "desc->handler", "desc->handle_irq" and "action->handler" caused a
large degree of confusion and made the code appear alot less clean than it
truly is.
I have also attempted a dual approach as well by introducing a
desc->chip alias - but that just wasnt robust enough and broke
frequently.
So lets get over with this quickly. The conversion was done automatically
via scripts and converts all the code in the kernel.
This renaming patch is the first one amongst the patches, so that the
remaining patches can stay flexible and can be merged and split up
without having some big monolithic patch act as a merge barrier.
[akpm@osdl.org: build fix]
[akpm@osdl.org: another build fix]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- Rename the GART_IOMMU option to IOMMU to make clear it's not
just for AMD
- Rewrite the help text to better emphatise this fact
- Make it an embedded option because too many people get it wrong.
To my astonishment I discovered the aacraid driver tests this
symbol directly. This looks quite broken to me - it's an internal
implementation detail of the PCI DMA API. Can the maintainer
please clarify what this test was intended to do?
Cc: linux-scsi@vger.kernel.org
Cc: alan@redhat.com
Cc: markh@osdl.org
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Since assign_irq_vector() can be called at runtime, its access of static
variables should be protected by a lock.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
From: "Andy Currid" <ACurrid@nvidia.com>
This patch fixes a kernel panic during boot that occurs on NVIDIA platforms
that have HPET enabled.
When HPET is enabled, the standard timer IRQ is routed to IOAPIC pin 2 and is
advertised as such in the ACPI APIC table - but an earlier workaround in the
kernel was ignoring this override. The fix is to honor timer IRQ overrides
from ACPI when HPET is detected on an NVIDIA platform.
Signed-off-by: Andy Currid <acurrid@nvidia.com>
Cc: "Brown, Len" <len.brown@intel.com>
Cc: "Yu, Luming" <luming.yu@intel.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The patch addresses a problem with ACPI SCI interrupt entry, which gets
re-used, and the IRQ is assigned to another unrelated device. The patch
corrects the code such that SCI IRQ is skipped and duplicate entry is
avoided. Second issue came up with VIA chipset, the problem was caused by
original patch assigning IRQs starting 16 and up. The VIA chipset uses
4-bit IRQ register for internal interrupt routing, and therefore cannot
handle IRQ numbers assigned to its devices. The patch corrects this
problem by allowing PCI IRQs below 16.
Cc: len.brown@intel.com
Signed-off by: Natalie Protasevich <Natalie.Protasevich@unisys.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When x86_64 timer init messages were changed to use apic verbosity
levels, two messages were missed and one got the wrong level. This
causes the last word of a suppressed message to print on a line by
itself. Fix that so either the entire message prints or none of it
does.
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I tested it on a couple of chipsets and it worked everywhere so it
should be ok as default for now.
So far I haven't done the great purge of the useless old check_timer
code yet though.
Can be overwritten with enable_8254_timer in the worst case
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The previous experiment for using apicmaintimer on ATI systems didn't
work out very well. In particular laptops with C2/C3 support often
don't let it tick during idle, which makes it useless. There were also
some other bugs that made the apicmaintimer often not used at all.
I tried some other experiments - running timer over RTC and some other
things but they didn't really work well neither.
I rechecked the specs now and it turns out this simple change is
actually enough to avoid the double ticks on the ATI systems. We just
turn off IRQ 0 in the 8254 and only route it directly using the IO-APIC.
I tested it on a few ATI systems and it worked there. In fact it worked
on all chipsets (NVidia, Intel, AMD, ATI) I tried it on.
According to the ACPI spec routing should always work through the
IO-APIC so I think it's the correct thing to do anyways (and most of the
old gunk in check_timer should be thrown away for x86-64).
But for 2.6.16 it's best to do a fairly minimal change:
- Use the known to be working everywhere-but-ATI IRQ0 both over 8254
and IO-APIC setup everywhere
- Except on ATI disable IRQ0 in the 8254
- Remove the code to select apicmaintimer on ATI chipsets
- Add some boot options to allow to override this (just paranoia)
In 2.6.17 I hope to switch the default over to this for everybody.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
[description from AK]
Old check for the IO-APIC watchdog during the timer check was wrong -
it obviously should only drop into this if the IO-APIC watchdog is used.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Many laptops have problems with ticking the local APIC timer in C2/C3.
The code added earlier to use it by default on ATI didn't really work
for them. Don't enable it when the system supports C2/C3.
This doesn't fix the problem fully, but at least it's not worse than before.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
They all have problems with IRQ 0 routing, so just use the APIC on them.
Can be overwritten with "noapicmaintimer"
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
