irq_vector[] can now become static.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndi Kleen <ak@suse.de>
Acked-by: NEric W. Biederman <ebiederm@xmission.com>
Acked-by: NIngo Molnar <mingo@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>

The Coverity checker noted that bad things might happen if
find_isa_irq_apic() returned -1.

[akpm@osdl.org: add debugging checks]
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Acked-by: NIngo Molnar <mingo@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>

Add a way to disable the timer IRQ routing check via a boot option.  The
VMI timer code uses this to avoid triggering the pester Mingo code, which
probes for some very unusual and broken motherboard routings.  It fires
100% of the time when using a paravirtual delay mechanism instead of using
a realtime delay, since there is no elapsed real time, and the 4 timer IRQs
have not yet been delivered.

In addition, it is entirely possible, though improbable, that this bug
could surface on real hardware which picks a particularly bad time to enter
SMM mode, causing a long latency during one of the timer IRQs.

While here, make check_timer be __init.
Signed-off-by: NZachary Amsden <zach@vmware.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
[chrisw: use no_timer_check to bring inline with x86_64 as per Andi's request]
Signed-off-by: NChris Wright <chrisw@sous-sol.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>

Interrupt could happen between setting the IO-APIC entry
and setting its interrupt data.

Pointed out by Linus.
Signed-off-by: NAndi Kleen <ak@suse.de>

Komuro reports that ISA interrupts do not work after a disable_irq(),
causing some PCMCIA drivers to not work, with messages like

	eth0: Asix AX88190: io 0x300, irq 3, hw_addr xx:xx:xx:xx:xx:xx
	eth0: found link beat
	eth0: autonegotiation complete: 100baseT-FD selected
	eth0: interrupt(s) dropped!
	eth0: interrupt(s) dropped!
	eth0: interrupt(s) dropped!
	...

Linus Torvalds <torvalds@osdl.org> said:

  "Now, edge-triggered interrupts are a _lot_ harder to mask, because the
   Intel APIC is an unbelievable piece of sh*t, and has the edge-detect logic
   _before_ the mask logic, so if a edge happens _while_ the device is
   masked, you'll never ever see the edge ever again (unmasking will not
   cause a new edge, so you simply lost the interrupt).

   So when you "mask" an edge-triggered IRQ, you can't really mask it at all,
   because if you did that, you'd lose it forever if the IRQ comes in while
   you masked it. Instead, we're supposed to leave it active, and set a flag,
   and IF the IRQ comes in, we just remember it, and mask it at that point
   instead, and then on unmasking, we have to replay it by sending a
   self-IPI."

This trivial patch solves the problem.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@redhat.com>
Acked-by: NKomuro <komurojun-mbn@nifty.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This refactoring actually optimizes the code a little by caching the value
that we think the device is programmed with instead of reading it back from
the hardware.  Which simplifies the code a little and should speed things up a
bit.

This patch introduces the concept of a ht_irq_msg and modifies the
architecture read/write routines to update this code.

There is a minor consistency fix here as well as x86_64 forgot to initialize
the htirq as masked.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Cc: Andi Kleen <ak@suse.de>
Acked-by: NBryan O'Sullivan <bos@pathscale.com>
Cc: <olson@pathscale.com>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

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: NLinus Torvalds <torvalds@osdl.org>

This is preparation for fixing the ordering of the accesses that
got broken by the commit cf4c6a2f when
factoring out the "common" io apic routing entry accesses.

Move the accessor function (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: NLinus Torvalds <torvalds@osdl.org>

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: NIngo Molnar <mingo@elte.hu>
Acked-by: NThomas 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: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

hw_interrupt_type is deprecated in favour of struct irq_chip.

[mingo@elte.hu: do x86_64 too]
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus 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: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NLinus 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: NEric 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: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus 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: NEric 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: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus 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: NEric 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: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus 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

[akpm@osdl.org: cleanup]
Signed-off-by: NEric 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: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus 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: NEric 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: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus 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 stuck this hack of assuming irq == vector until the
depencencies in the generic msi code are removed.
Signed-off-by: NEric 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: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch converts all the i386 PIC controllers (except VisWS and Voyager,
which I could not test - but which should still work as old-style IRQ layers)
to the new and simpler irq-chip interrupt handling layer.

[akpm@osdl.org: build fix]
[mingo@elte.hu: enable fasteoi handler for i386 level-triggered IO-APIC irqs]
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch replaces the open-coded early commandline parsing
throughout the i386 boot code with the generic mechanism (already used
by ppc, powerpc, ia64 and s390).  The code was inconsistent with
whether it deletes the option from the cmdline or not, meaning some of
these will get passed through the environment into init.

This transformation is mainly mechanical, but there are some notable
parts:

1) Grammar: s/linux never set's it up/linux never sets it up/

2) Remove hacked-in earlyprintk= option scanning.  When someone
   actually implements CONFIG_EARLY_PRINTK, then they can use
   early_param().
[AK: actually it is implemented, but I'm adding the early_param it in the next
x86-64 patch]

3) Move declaration of generic_apic_probe() from setup.c into asm/apic.h

4) Various parameters now moved into their appropriate files (thanks Andi).

5) All parse functions which examine arg need to check for NULL,
   except one where it has subtle humor value.

AK: readded acpi_sci handling which was completely dropped
AK: moved some more variables into acpi/boot.c

Cc: len.brown@intel.com
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndi 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.

Similar to earlier x86-64 patch.

Includes a fix by Jiri Slaby for a mistake that broke resume
Signed-off-by: NAndi Kleen <ak@suse.de>

There are some machines around (large xSeries or Unisys ES7000) that
need physical IO-APIC destination mode to access all of their IO
devices. This currently doesn't work in UP kernels as used in
distribution installers.

This patch allows to compile even UP kernels as GENERICARCH which
allows to use physical or clustered APIC mode.
Signed-off-by: NAndi Kleen <ak@suse.de>

Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.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: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Consolidation: remove the pending_irq_cpumask[NR_IRQS] array and move it into
the irq_desc[NR_IRQS].pending_mask field.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus 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: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix a potential deadlock scenario introduced by io_apic.c's new vector_lock
on i386 and x86_64.

Found by the locking correctness validator. The patch was boot-tested on
x86. For details of the deadlock scenario, see the validator output:

  ======================================================
  [ BUG: hard-safe -> hard-unsafe lock order detected! ]
  ------------------------------------------------------
  idle/1 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
   (msi_lock){....}, at: [<c04ff8d2>] startup_msi_irq_wo_maskbit+0x10/0x35

  and this task is already holding:
   (&irq_desc[i].lock){++..}, at: [<c015b924>] probe_irq_on+0x36/0x107
  which would create a new lock dependency:
   (&irq_desc[i].lock){++..} -> (msi_lock){....}

  but this new dependency connects a hard-irq-safe lock:
   (&irq_desc[i].lock){++..}
  ... which became hard-irq-safe at:
    [<c01468c4>] lockdep_acquire+0x68/0x84
    [<c10485e9>] _spin_lock+0x21/0x2f
    [<c015aff5>] __do_IRQ+0x3d/0x113
    [<c01062d3>] do_IRQ+0x8c/0xad

  to a hard-irq-unsafe lock:
   (vector_lock){--..}
  ... which became hard-irq-unsafe at:
  ...  [<c01468c4>] lockdep_acquire+0x68/0x84
    [<c10485e9>] _spin_lock+0x21/0x2f
    [<c011b5e8>] assign_irq_vector+0x34/0xc8
    [<c1aa82fa>] setup_IO_APIC+0x45a/0xcff
    [<c1aa56e3>] smp_prepare_cpus+0x5ea/0x8aa
    [<c010033f>] init+0x32/0x2cb
    [<c0102005>] kernel_thread_helper+0x5/0xb

  which could potentially lead to deadlocks!

  other info that might help us debug this:

  3 locks held by idle/1:
   #0:  (port_mutex){--..}, at: [<c067070d>] uart_add_one_port+0x61/0x289
   #1:  (&state->mutex){--..}, at: [<c067071f>] uart_add_one_port+0x73/0x289
   #2:  (&irq_desc[i].lock){++..}, at: [<c015b924>] probe_irq_on+0x36/0x107

  the hard-irq-safe lock's dependencies:
  -> (&irq_desc[i].lock){++..} ops: 9861 {
     initial-use  at:
                          [<c01468c4>] lockdep_acquire+0x68/0x84
                          [<c10487f4>] _spin_lock_irqsave+0x2a/0x3a
                          [<c015b415>] setup_irq+0x9b/0x14d
                          [<c1aaa4c4>] time_init_hook+0xf/0x11
                          [<c1a9f320>] time_init+0x44/0x46
                          [<c1a9955f>] start_kernel+0x191/0x38f
                          [<c0100210>] 0xc0100210
     in-hardirq-W at:
                          [<c01468c4>] lockdep_acquire+0x68/0x84
                          [<c10485e9>] _spin_lock+0x21/0x2f
                          [<c015aff5>] __do_IRQ+0x3d/0x113
                          [<c01062d3>] do_IRQ+0x8c/0xad
     in-softirq-W at:
                          [<c01468c4>] lockdep_acquire+0x68/0x84
                          [<c10485e9>] _spin_lock+0x21/0x2f
                          [<c015aff5>] __do_IRQ+0x3d/0x113
                          [<c01062d3>] do_IRQ+0x8c/0xad
   }
   ... key      at: [<c1ea31e0>] irq_desc_lock_type+0x0/0x20
    -> (i8259A_lock){++..} ops: 5149 {
       initial-use  at:
                        [<c01468c4>] lockdep_acquire+0x68/0x84
                        [<c10487f4>] _spin_lock_irqsave+0x2a/0x3a
                        [<c0108090>] init_8259A+0x11/0x8f
                        [<c1aa0d22>] init_ISA_irqs+0x12/0x4d
                        [<c1aaa4f0>] pre_intr_init_hook+0x8/0xa
                        [<c1aa0cb9>] init_IRQ+0xe/0x65
                        [<c1a99546>] start_kernel+0x178/0x38f
                        [<c0100210>] 0xc0100210
       in-hardirq-W at:
                        [<c01468c4>] lockdep_acquire+0x68/0x84
                        [<c10487f4>] _spin_lock_irqsave+0x2a/0x3a
                        [<c0107fb0>] mask_and_ack_8259A+0x1b/0xcc
                        [<c015b007>] __do_IRQ+0x4f/0x113
                        [<c01062d3>] do_IRQ+0x8c/0xad
       in-softirq-W at:
                        [<c01468c4>] lockdep_acquire+0x68/0x84
                        [<c10487f4>] _spin_lock_irqsave+0x2a/0x3a
                        [<c0107fb0>] mask_and_ack_8259A+0x1b/0xcc
                        [<c015b007>] __do_IRQ+0x4f/0x113
                        [<c01062d3>] do_IRQ+0x8c/0xad
     }
     ... key      at: [<c142f174>] i8259A_lock+0x14/0x40
   ... acquired at:
     [<c01468c4>] lockdep_acquire+0x68/0x84
     [<c10487f4>] _spin_lock_irqsave+0x2a/0x3a
     [<c0107eb2>] enable_8259A_irq+0x10/0x47
     [<c0107f12>] startup_8259A_irq+0x8/0xc
     [<c015b45e>] setup_irq+0xe4/0x14d
     [<c1aaa4c4>] time_init_hook+0xf/0x11
     [<c1a9f320>] time_init+0x44/0x46
     [<c1a9955f>] start_kernel+0x191/0x38f
     [<c0100210>] 0xc0100210

    -> (ioapic_lock){+...} ops: 122 {
       initial-use  at:
                        [<c01468c4>] lockdep_acquire+0x68/0x84
                        [<c10487f4>] _spin_lock_irqsave+0x2a/0x3a
                        [<c1aa71db>] io_apic_get_version+0x16/0x55
                        [<c1aa5c73>] mp_register_ioapic+0xc6/0x127
                        [<c1aa382e>] acpi_parse_ioapic+0x2d/0x39
                        [<c1abe031>] acpi_table_parse_madt_family+0xb4/0x100
                        [<c1abe093>] acpi_table_parse_madt+0x16/0x18
                        [<c1aa3c8a>] acpi_boot_init+0x132/0x251
                        [<c1aa08ea>] setup_arch+0xd36/0xe37
                        [<c1a99434>] start_kernel+0x66/0x38f
                        [<c0100210>] 0xc0100210
       in-hardirq-W at:
                        [<c01468c4>] lockdep_acquire+0x68/0x84
                        [<c10487f4>] _spin_lock_irqsave+0x2a/0x3a
                        [<c011bce1>] mask_IO_APIC_irq+0x11/0x31
                        [<c011c5cc>] ack_edge_ioapic_vector+0x31/0x41
                        [<c015b007>] __do_IRQ+0x4f/0x113
                        [<c01062d3>] do_IRQ+0x8c/0xad
     }
     ... key      at: [<c1432514>] ioapic_lock+0x14/0x3c
      -> (i8259A_lock){++..} ops: 5149 {
         initial-use  at:
                         [<c01468c4>] lockdep_acquire+0x68/0x84
                         [<c10487f4>] _spin_lock_irqsave+0x2a/0x3a
                         [<c0108090>] init_8259A+0x11/0x8f
                         [<c1aa0d22>] init_ISA_irqs+0x12/0x4d
                         [<c1aaa4f0>] pre_intr_init_hook+0x8/0xa
                         [<c1aa0cb9>] init_IRQ+0xe/0x65
                         [<c1a99546>] start_kernel+0x178/0x38f
                         [<c0100210>] 0xc0100210
         in-hardirq-W at:
                         [<c01468c4>] lockdep_acquire+0x68/0x84
                         [<c10487f4>] _spin_lock_irqsave+0x2a/0x3a
                         [<c0107fb0>] mask_and_ack_8259A+0x1b/0xcc
                         [<c015b007>] __do_IRQ+0x4f/0x113
                         [<c01062d3>] do_IRQ+0x8c/0xad
         in-softirq-W at:
                         [<c01468c4>] lockdep_acquire+0x68/0x84
                         [<c10487f4>] _spin_lock_irqsave+0x2a/0x3a
                         [<c0107fb0>] mask_and_ack_8259A+0x1b/0xcc
                         [<c015b007>] __do_IRQ+0x4f/0x113
                         [<c01062d3>] do_IRQ+0x8c/0xad
       }
       ... key      at: [<c142f174>] i8259A_lock+0x14/0x40
     ... acquired at:
     [<c01468c4>] lockdep_acquire+0x68/0x84
     [<c10487f4>] _spin_lock_irqsave+0x2a/0x3a
     [<c0107e6b>] disable_8259A_irq+0x10/0x47
     [<c011bdbd>] startup_edge_ioapic_vector+0x31/0x58
     [<c015b45e>] setup_irq+0xe4/0x14d
     [<c015b5a1>] request_irq+0xda/0xf9
     [<c1ac983a>] rtc_init+0x6a/0x1a7
     [<c0100457>] init+0x14a/0x2cb
     [<c0102005>] kernel_thread_helper+0x5/0xb

   ... acquired at:
     [<c01468c4>] lockdep_acquire+0x68/0x84
     [<c10487f4>] _spin_lock_irqsave+0x2a/0x3a
     [<c011bce1>] mask_IO_APIC_irq+0x11/0x31
     [<c011c5cc>] ack_edge_ioapic_vector+0x31/0x41
     [<c015b007>] __do_IRQ+0x4f/0x113
     [<c01062d3>] do_IRQ+0x8c/0xad

  the hard-irq-unsafe lock's dependencies:
  -> (vector_lock){--..} ops: 31 {
     initial-use  at:
                          [<c01468c4>] lockdep_acquire+0x68/0x84
                          [<c10485e9>] _spin_lock+0x21/0x2f
                          [<c011b5e8>] assign_irq_vector+0x34/0xc8
                          [<c1aa82fa>] setup_IO_APIC+0x45a/0xcff
                          [<c1aa56e3>] smp_prepare_cpus+0x5ea/0x8aa
                          [<c010033f>] init+0x32/0x2cb
                          [<c0102005>] kernel_thread_helper+0x5/0xb
     softirq-on-W at:
                          [<c01468c4>] lockdep_acquire+0x68/0x84
                          [<c10485e9>] _spin_lock+0x21/0x2f
                          [<c011b5e8>] assign_irq_vector+0x34/0xc8
                          [<c1aa82fa>] setup_IO_APIC+0x45a/0xcff
                          [<c1aa56e3>] smp_prepare_cpus+0x5ea/0x8aa
                          [<c010033f>] init+0x32/0x2cb
                          [<c0102005>] kernel_thread_helper+0x5/0xb
     hardirq-on-W at:
                          [<c01468c4>] lockdep_acquire+0x68/0x84
                          [<c10485e9>] _spin_lock+0x21/0x2f
                          [<c011b5e8>] assign_irq_vector+0x34/0xc8
                          [<c1aa82fa>] setup_IO_APIC+0x45a/0xcff
                          [<c1aa56e3>] smp_prepare_cpus+0x5ea/0x8aa
                          [<c010033f>] init+0x32/0x2cb
                          [<c0102005>] kernel_thread_helper+0x5/0xb
   }
   ... key      at: [<c1432574>] vector_lock+0x14/0x3c

  stack backtrace:
   [<c0104f36>] show_trace+0xd/0xf
   [<c010543e>] dump_stack+0x17/0x19
   [<c0144e34>] check_usage+0x1f6/0x203
   [<c0146395>] __lockdep_acquire+0x8c2/0xaa5
   [<c01468c4>] lockdep_acquire+0x68/0x84
   [<c10487f4>] _spin_lock_irqsave+0x2a/0x3a
   [<c04ff8d2>] startup_msi_irq_wo_maskbit+0x10/0x35
   [<c015b932>] probe_irq_on+0x44/0x107
   [<c0673d58>] serial8250_config_port+0x84b/0x986
   [<c06707b1>] uart_add_one_port+0x105/0x289
   [<c1ace54b>] serial8250_init+0xc3/0x10a
   [<c0100457>] init+0x14a/0x2cb
   [<c0102005>] kernel_thread_helper+0x5/0xb
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Misc header cleanup for nmi watchdog.
Signed-off-by: NDon Zickus <dzickus@redhat.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Simplify (remove duplication of) code in ioapic_register_intr().
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus 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: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

On i386, kernel irq balance doesn't work.

1) In function do_irq_balance, after kernel finds the min_loaded cpu but
   before calling set_pending_irq to really pin the selected_irq to the
   target cpu, kernel does a cpus_and with irq_affinity[selected_irq].
   Later on, when the irq is acked, kernel would calls
   move_native_irq=>desc->handler->set_affinity to change the irq affinity.
    However, every function pointed by
   hw_interrupt_type->set_affinity(unsigned int irq, cpumask_t cpumask)
   always changes irq_affinity[irq] to cpumask.  Next time when recalling
   do_irq_balance, it has to do cpu_ands again with
   irq_affinity[selected_irq], but irq_affinity[selected_irq] already
   becomes one cpu selected by the first irq balance.

2) Function balance_irq in file arch/i386/kernel/io_apic.c has the same
   issue.

[akpm@osdl.org: cleanups]
Signed-off-by: NZhang Yanmin <yanmin.zhang@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus 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: NAndi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The boot cmdline is parsed in parse_early_param() and
parse_args(,unknown_bootoption).

And __setup() is used in obsolete_checksetup().

	start_kernel()
		-> parse_args()
			-> unknown_bootoption()
				-> obsolete_checksetup()

If __setup()'s callback (->setup_func()) returns 1 in
obsolete_checksetup(), obsolete_checksetup() thinks a parameter was
handled.

If ->setup_func() returns 0, obsolete_checksetup() tries other
->setup_func().  If all ->setup_func() that matched a parameter returns 0,
a parameter is seted to argv_init[].

Then, when runing /sbin/init or init=app, argv_init[] is passed to the app.
If the app doesn't ignore those arguments, it will warning and exit.

This patch fixes a wrong usage of it, however fixes obvious one only.
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>

This patch replaces for_each_cpu with for_each_possible_cpu.

under arch/i386.
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

When we stop allocating percpu memory for not-possible CPUs we must not touch
the percpu data for not-possible CPUs at all.  The correct way of doing this
is to test cpu_possible() or to use for_each_cpu().

This patch is a kernel-wide sweep of all instances of NR_CPUS.  I found very
few instances of this bug, if any.  But the patch converts lots of open-coded
test to use the preferred helper macros.

Cc: Mikael Starvik <starvik@axis.com>
Cc: David Howells <dhowells@redhat.com>
Acked-by: NKyle McMartin <kyle@parisc-linux.org>
Cc: Anton Blanchard <anton@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Christian Zankel <chris@zankel.net>
Cc: Philippe Elie <phil.el@wanadoo.fr>
Cc: Nathan Scott <nathans@sgi.com>
Cc: Jens Axboe <axboe@suse.de>
Cc: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Checking APIC version instead of CPU family to determine XAPIC. Family 6
CPU could have xapic as well.

Signed-off-by: Shaohua Li<shaohua.li@intel.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: "Seth, Rohit" <rohit.seth@intel.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

ATI chipsets tend to generate double timer interrupts for the local APIC
timer when both the 8254 and the IO-APIC timer pins are enabled.  This is
because they route it to both and the result is anded together and the CPU
ends up processing it twice.

This patch changes check_timer to disable the 8254 routing for interrupt 0.

I think it would be safe on all chipsets actually (i tested it on a couple
and it worked everywhere) and Windows seems to do it in a similar way, but
to be conservative this patch only enables this mode on ATI (and adds
options to enable/disable too)

Ported over from a similar x86-64 change.

I reused the ACPI earlyquirk infrastructure for the ATI bridge check, but
tweaked it a bit to work even without ACPI.

Inspired by a patch from Chuck Ebbert, but redone.

Cc: Chuck Ebbert <76306.1226@compuserve.com>
Cc: "Brown, Len" <len.brown@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

[description from AK]

This fixes booting in APIC mode on some ACER laptops. x86-64
did a similar change some time ago.

See http://bugzilla.kernel.org/show_bug.cgi?id=4700 for details
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Currently we attempt to restore virtual wire mode on reboot, which only
works if we can figure out where the i8259 is connected.  This is very
useful when we are kexec another kernel and likely helpful to an peculiar
BIOS that make assumptions about how the system is setup.

Since the acpi MADT table does not provide the location where the i8259 is
connected we have to look at the hardware to figure it out.

Most systems have the i8259 connected the local apic of the cpu so won't be
affected but people running Opteron and some serverworks chipsets should be
able to use kexec now.

In addition this patch removes the hard coded assumption that the io_apic
that delivers isa interrups is always known to the kernel as io_apic 0.
There does not appear to be anything to guarantee that assumption is true.

And From: Vivek Goyal <vgoyal@in.ibm.com>

  A minor fix to the patch which remembers the location of where i8259 is
  connected.  Now counter i has been replaced by apic.  counter i is having
  some junk value which was leading to non-detection of i8259 connected to
  IOAPIC.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

o Currently, during kexec reboot, IOAPIC is re-programmed back to virtual
  wire mode if there was an i8259 connected to it. This enables getting
  timer interrupts in second kernel in legacy mode.

o After putting into virtual wire mode, IOAPIC delivers the i8259 interrupts
  to CPU0. This works well for kexec but not for kdump as we might crash
  on a different CPU and second kernel will not see timer interrupts.

o This patch modifies the redirection table entry to deliver the timer
  interrupts to the cpu we are rebooting (instead of hardcoding to zero).
  This ensures that second kernel receives timer interrupts even on a
  non-boot cpu.
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Seth, Rohit" <rohit.seth@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Setting irq affinity stops working when MSI is enabled.  With MSI, move_irq
is empty, so we can't change irq affinity.  It appears a typo in Ashok's
original commit for this issue.  X86_64 actually is using move_native_irq.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>