x86, ioapic: Use irq_cfg() instead of irq_get_chip_data() for better readability

Use defined helper function irq_cfg() instead of irq_get_chip_data() for
better readability.

Signed-off-by: Jiang Li

x86, ioapic: Use irq_cfg() instead of irq_get_chip_data() for better readability

Use defined helper function irq_cfg() instead of irq_get_chip_data() for
better readability.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1402302011-23642-15-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

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x86, ioapic: Introduce helper utilities to walk ioapics and pins

Introduce helper utilities for_each_ioapic(), for_each_ioapic_reverse(),
for_each_pin() and for_each_ioapic_pin() to walk ioapics and

x86, ioapic: Introduce helper utilities to walk ioapics and pins

Introduce helper utilities for_each_ioapic(), for_each_ioapic_reverse(),
for_each_pin() and for_each_ioapic_pin() to walk ioapics and pins.
They will be rewritten e will rewrite later to support IOAPIC hotplug.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1402302011-23642-14-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

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x86, ioapic: Kill static variable nr_irqs_gsi

Static variable nr_irqs_gsi is used to maintain the lowest dynamic
allocatable IRQ number. It may cause trouble when enabling dynamic
IRQ allocation for

x86, ioapic: Kill static variable nr_irqs_gsi

Static variable nr_irqs_gsi is used to maintain the lowest dynamic
allocatable IRQ number. It may cause trouble when enabling dynamic
IRQ allocation for IOAPIC, so use arch_dynirq_lower_bound() to
avoid directly accessing nr_irqs_gsi and kill nr_irqs_gsi.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1402302011-23642-13-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

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x86, ioapic: Kill unused global variable timer_through_8259

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com

x86, ioapic: Kill unused global variable timer_through_8259

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1402302011-23642-12-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

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x86, irq, trivial: Minor improvements of IRQ related code

1) Kill unused MAX_HARDIRQS_PER_CPU.
2) Improve function prototype declararions.
3) Simple typo fix, change "gsit" to "gsi".
4) Use macro VE

x86, irq, trivial: Minor improvements of IRQ related code

1) Kill unused MAX_HARDIRQS_PER_CPU.
2) Improve function prototype declararions.
3) Simple typo fix, change "gsit" to "gsi".
4) Use macro VECTOR_UNDEFINED instead of hard-coded -1.
5) Kill redundant comments.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Jiri Kosina <trivial@kernel.org>
Link: http://lkml.kernel.org/r/1402302011-23642-11-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

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x86, irq: Remove pointless irq_reserve_irqs() call

That's a leftover from the time where x86 supported SPARSE_IRQ=n.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Grant Likely <g

x86, irq: Remove pointless irq_reserve_irqs() call

That's a leftover from the time where x86 supported SPARSE_IRQ=n.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Grant Likely <grant.likely@linaro.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/20140507154338.967285614@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

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x86: Remove create/destroy_irq()

No more users. Remove the cruft

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Grant Likely <grant.likely@linaro.org>
Cc: Tony Luck <tony.luck@int

x86: Remove create/destroy_irq()

No more users. Remove the cruft

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Grant Likely <grant.likely@linaro.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/20140507154336.760446122@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

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x86: Get rid of get_nr_irqs_gsi()

No need to expose this outside of the ioapic code. The dynamic
allocations are guaranteed not to happen in the gsi space. See commit
62a08ae2a.

Signed-off-by: Thom

x86: Get rid of get_nr_irqs_gsi()

No need to expose this outside of the ioapic code. The dynamic
allocations are guaranteed not to happen in the gsi space. See commit
62a08ae2a.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Grant Likely <grant.likely@linaro.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: x86@kernel.org
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20140507154335.959870037@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

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x86: ioapic: Use irq_alloc/free_hwirq()

No functional change just less crap.

This does not replace the requirement to move x86 to irq domains, but
it limits the mess to some degree.

Signed-off-by:

x86: ioapic: Use irq_alloc/free_hwirq()

No functional change just less crap.

This does not replace the requirement to move x86 to irq domains, but
it limits the mess to some degree.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Grant Likely <grant.likely@linaro.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/20140507154335.749579081@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

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x86: Implement arch_setup/teardown_hwirq()

This is just a cleanup to get rid of the create/destroy_irq variants
which were designed in hell.

The long term solution for x86 is to switch over to irq

x86: Implement arch_setup/teardown_hwirq()

This is just a cleanup to get rid of the create/destroy_irq variants
which were designed in hell.

The long term solution for x86 is to switch over to irq domains and
cleanup the whole vector allocation mess.

The generic irq_alloc_hwirqs() interface deliberately prevents
multi-MSI vector allocation to further enforce the irq domain
conversion (aside of the desire to support ioapic hotplug).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Grant Likely <grant.likely@linaro.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/20140507154334.482904047@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

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x86/irq: Fix fixup_irqs() error handling

Several patches to fix cpu hotplug and the down'd cpu's irq
relocations have been submitted in the past month or so. The
patches should resolve the problems

x86/irq: Fix fixup_irqs() error handling

Several patches to fix cpu hotplug and the down'd cpu's irq
relocations have been submitted in the past month or so. The
patches should resolve the problems with cpu hotplug and irq
relocation, however, there is always a possibility that a bug
still exists. The big problem with debugging these irq
reassignments is that the cpu down completes and then we get
random stack traces from drivers for which irqs have not been
properly assigned to a new cpu. The stack traces are a mix of
storage, network, and other kernel subsystem (I once saw the
serial port stop working ...) warnings and failures.

The problem with these failures is that they are difficult to
diagnose. There is no warning in the cpu hotplug down path to
indicate that an IRQ has failed to be assigned to a new cpu, and
all we are left with is a stack trace from a driver, or a
non-functional device. If we had some information on the
console debugging these situations would be much easier; after
all we can map an IRQ to a device by simply using lspci or
/proc/interrupts.

The current code, fixup_irqs(), which migrates IRQs from the
down'd cpu and is called close to the end of the cpu down path,
calls chip->set_irq_affinity which eventually calls
__assign_irq_vector(). Errors are not propogated back from this
function call and this results in silent irq relocation
failures.

This patch fixes this issue by returning the error codes up the
call stack and prints out a warning if there is a relocation
failure.

Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Rui Wang <rui.y.wang@intel.com>
Cc: Liu Ping Fan <kernelfans@gmail.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>
Cc: Lv Zheng <lv.zheng@intel.com>
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Cc: Yang Zhang <yang.z.zhang@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Steven Rostedt (Red Hat) <rostedt@goodmis.org>
Cc: Li Fei <fei.li@intel.com>
Cc: gong.chen@linux.intel.com
Link: http://lkml.kernel.org/r/1396440673-18286-1-git-send-email-prarit@redhat.com
[ Made small cleanliness tweaks. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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asmlinkage, x86: Add explicit __visible to arch/x86/*

As requested by Linus add explicit __visible to the asmlinkage users.
This marks all functions visible to assembler.

Tree sweep for arch/x86/*

asmlinkage, x86: Add explicit __visible to arch/x86/*

As requested by Linus add explicit __visible to the asmlinkage users.
This marks all functions visible to assembler.

Tree sweep for arch/x86/*

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1398984278-29319-3-git-send-email-andi@firstfloor.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

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genirq: x86: Ensure that dynamic irq allocation does not conflict

On x86 the allocation of irq descriptors may allocate interrupts which
are in the range of the GSI interrupts. That's wrong as those

genirq: x86: Ensure that dynamic irq allocation does not conflict

On x86 the allocation of irq descriptors may allocate interrupts which
are in the range of the GSI interrupts. That's wrong as those
interrupts are hardwired and we don't have the irq domain translation
like PPC. So one of these interrupts can be hooked up later to one of
the devices which are hard wired to it and the io_apic init code for
that particular interrupt line happily reuses that descriptor with a
completely different configuration so hell breaks lose.

Inside x86 we allocate dynamic interrupts from above nr_gsi_irqs,
except for a few usage sites which have not yet blown up in our face
for whatever reason. But for drivers which need an irq range, like the
GPIO drivers, we have no limit in place and we don't want to expose
such a detail to a driver.

To cure this introduce a function which an architecture can implement
to impose a lower bound on the dynamic interrupt allocations.

Implement it for x86 and set the lower bound to nr_gsi_irqs, which is
the end of the hardwired interrupt space, so all dynamic allocations
happen above.

That not only allows the GPIO driver to work sanely, it also protects
the bogus callsites of create_irq_nr() in hpet, uv, irq_remapping and
htirq code. They need to be cleaned up as well, but that's a separate
issue.

Reported-by: Jin Yao <yao.jin@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Krogerus Heikki <heikki.krogerus@intel.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1404241617360.28206@ionos.tec.linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

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x86/irq: Fix kbuild warning in smp_irq_move_cleanup_interrupt()

Fengguang Wu's 0day kernel build service reported the following build warning:

arch/x86/kernel/apic/io_apic.c:2211
smp_irq_move_c

x86/irq: Fix kbuild warning in smp_irq_move_cleanup_interrupt()

Fengguang Wu's 0day kernel build service reported the following build warning:

arch/x86/kernel/apic/io_apic.c:2211
smp_irq_move_cleanup_interrupt() warn: always true condition '(irq <= -1) => (0-u32max <= (-1))'

because irq is defined as an unsigned int instead of an int.
Fix this trivial error by redefining irq as a signed int. The
remaining consumers of the int are okay.

Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Link: http://lkml.kernel.org/r/1389620420-7110-1-git-send-email-prarit@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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x86/irq: Fix do_IRQ() interrupt warning for cpu hotplug retriggered irqs

During heavy CPU-hotplug operations the following spurious kernel warnings
can trigger:

do_IRQ: No ... irq handler for vec

x86/irq: Fix do_IRQ() interrupt warning for cpu hotplug retriggered irqs

During heavy CPU-hotplug operations the following spurious kernel warnings
can trigger:

do_IRQ: No ... irq handler for vector (irq -1)

[ See: https://bugzilla.kernel.org/show_bug.cgi?id=64831 ]

When downing a cpu it is possible that there are unhandled irqs
left in the APIC IRR register. The following code path shows
how the problem can occur:

1. CPU 5 is to go down.

2. cpu_disable() on CPU 5 executes with interrupt flag cleared
by local_irq_save() via stop_machine().

3. IRQ 12 asserts on CPU 5, setting IRR but not ISR because
interrupt flag is cleared (CPU unabled to handle the irq)

4. IRQs are migrated off of CPU 5, and the vectors' irqs are set
to -1. 5. stop_machine() finishes cpu_disable()

6. cpu_die() for CPU 5 executes in normal context.

7. CPU 5 attempts to handle IRQ 12 because the IRR is set for
IRQ 12. The code attempts to find the vector's IRQ and cannot
because it has been set to -1. 8. do_IRQ() warning displays
warning about CPU 5 IRQ 12.

I added a debug printk to output which CPU & vector was
retriggered and discovered that that we are getting bogus
events. I see a 100% correlation between this debug printk in
fixup_irqs() and the do_IRQ() warning.

This patchset resolves this by adding definitions for
VECTOR_UNDEFINED(-1) and VECTOR_RETRIGGERED(-2) and modifying
the code to use them.

Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=64831
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Reviewed-by: Rui Wang <rui.y.wang@intel.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Cc: Yang Zhang <yang.z.zhang@Intel.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: janet.morgan@Intel.com
Cc: tony.luck@Intel.com
Cc: ruiv.wang@gmail.com
Link: http://lkml.kernel.org/r/1388938252-16627-1-git-send-email-prarit@redhat.com
[ Cleaned up the code a bit. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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ACPI: Clean up inclusions of ACPI header files

Replace direct inclusions of <acpi/acpi.h>, <acpi/acpi_bus.h> and
<acpi/acpi_drivers.h>, which are incorrect, with <linux/acpi.h>
inclusions and remove

ACPI: Clean up inclusions of ACPI header files

Replace direct inclusions of <acpi/acpi.h>, <acpi/acpi_bus.h> and
<acpi/acpi_drivers.h>, which are incorrect, with <linux/acpi.h>
inclusions and remove some inclusions of those files that aren't
necessary.

First of all, <acpi/acpi.h>, <acpi/acpi_bus.h> and <acpi/acpi_drivers.h>
should not be included directly from any files that are built for
CONFIG_ACPI unset, because that generally leads to build warnings about
undefined symbols in !CONFIG_ACPI builds. For CONFIG_ACPI set,
<linux/acpi.h> includes those files and for CONFIG_ACPI unset it
provides stub ACPI symbols to be used in that case.

Second, there are ordering dependencies between those files that always
have to be met. Namely, it is required that <acpi/acpi_bus.h> be included
prior to <acpi/acpi_drivers.h> so that the acpi_pci_root declarations the
latter depends on are always there. And <acpi/acpi.h> which provides
basic ACPICA type declarations should always be included prior to any other
ACPI headers in CONFIG_ACPI builds. That also is taken care of including
<linux/acpi.h> as appropriate.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> (drivers/pci stuff)
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> (Xen stuff)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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x86/ioapic: Check attr against the previous setting when programmed more than once

When programming ioapic pinX more than once, current code
does not check whether the later attr (trigger & polarity

x86/ioapic: Check attr against the previous setting when programmed more than once

When programming ioapic pinX more than once, current code
does not check whether the later attr (trigger & polarity) is the
same as the former or not.

This causes broken semantics which can be observed in a qemu q35
machine, where ioapic's ioredtbl[x] can never be set as low-active,
even if the hpet driver registered it.

And hpet driver may share a high-level active IRQ line with other
devices. So in qemu, when hpet-dev asserts low-level as kernel
expects, the kernel has no response.

With this patch, we can observe an ioredtbl[x] set as low-active
for hpet.

Fix it by reporting -EBUSY to the caller, when attr is different.

Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
Cc: Kevin Hao <haokexin@gmail.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1377248327-19633-1-git-send-email-pingfank@linux.vnet.ibm.com
[ Made small readability edits to both the changelog and the code. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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x86/ioapic/kcrash: Prevent crash_kexec() from deadlocking on ioapic_lock

Prevent crash_kexec() from deadlocking on ioapic_lock. When
crash_kexec() is executed on a CPU, the CPU will take ioapic_lock

x86/ioapic/kcrash: Prevent crash_kexec() from deadlocking on ioapic_lock

Prevent crash_kexec() from deadlocking on ioapic_lock. When
crash_kexec() is executed on a CPU, the CPU will take ioapic_lock
in disable_IO_APIC(). So if the cpu gets an NMI while locking
ioapic_lock, a deadlock will happen.

In this patch, ioapic_lock is zapped/initialized before disable_IO_APIC().

You can reproduce this deadlock the following way:

1. Add mdelay(1000) after raw_spin_lock_irqsave() in
native_ioapic_set_affinity()@arch/x86/kernel/apic/io_apic.c

Although the deadlock can occur without this modification, it will increase
the potential of the deadlock problem.

2. Build and install the kernel

3. Set up the OS which will run panic() and kexec when NMI is injected
# echo "kernel.unknown_nmi_panic=1" >> /etc/sysctl.conf
# vim /etc/default/grub
add "nmi_watchdog=0 crashkernel=256M" in GRUB_CMDLINE_LINUX line
# grub2-mkconfig

4. Reboot the OS

5. Run following command for each vcpu on the guest
# while true; do echo <CPU num> > /proc/irq/<IO-APIC-edge or IO-APIC-fasteoi>/smp_affinitity; done;
By running this command, cpus will get ioapic_lock for setting affinity.

6. Inject NMI (push a dump button or execute 'virsh inject-nmi <domain>' if you
use VM). After injecting NMI, panic() is called in an nmi-handler context.
Then, kexec will normally run in panic(), but the operation will be stopped
by deadlock on ioapic_lock in crash_kexec()->machine_crash_shutdown()->
native_machine_crash_shutdown()->disable_IO_APIC()->clear_IO_APIC()->
clear_IO_APIC_pin()->ioapic_read_entry().

Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: yrl.pp-manager.tt@hitachi.com
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Link: http://lkml.kernel.org/r/20130820070107.28245.83806.stgit@yunodevel
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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x86, io_apic: Introduce eoi_ioapic_pin call-back

This callback replaces the old __eoi_ioapic_pin function
which needs a special path for interrupt remapping.

Signed-off-by: Joerg Roedel <joro@8byte

x86, io_apic: Introduce eoi_ioapic_pin call-back

This callback replaces the old __eoi_ioapic_pin function
which needs a special path for interrupt remapping.

Signed-off-by: Joerg Roedel <joro@8bytes.org>
Acked-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

show more ...

x86, msi: Introduce x86_msi.compose_msi_msg call-back

This call-back points to the right function for initializing
the msi_msg structure. The old code for msi_msg generation
was split up into the ir

x86, msi: Introduce x86_msi.compose_msi_msg call-back

This call-back points to the right function for initializing
the msi_msg structure. The old code for msi_msg generation
was split up into the irq-remapped and the default case.

The irq-remapped case just calls into the specific Intel or
AMD implementation when the device is behind an IOMMU.
Otherwise the default function is called.

Signed-off-by: Joerg Roedel <joro@8bytes.org>
Acked-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

show more ...

x86, irq: Introduce setup_remapped_irq()

This function does irq-remapping specific interrupt setup
like modifying the chip defaults.

Signed-off-by: Joerg Roedel <joro@8bytes.org>
Acked-by: Sebastia

x86, irq: Introduce setup_remapped_irq()

This function does irq-remapping specific interrupt setup
like modifying the chip defaults.

Signed-off-by: Joerg Roedel <joro@8bytes.org>
Acked-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

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x86, irq: Move irq_remapped() check into free_remapped_irq

The function is called unconditionally now in IO-APIC code
removing another irq_remapped() check from x86 core code.

Signed-off-by: Joerg

x86, irq: Move irq_remapped() check into free_remapped_irq

The function is called unconditionally now in IO-APIC code
removing another irq_remapped() check from x86 core code.

Signed-off-by: Joerg Roedel <joro@8bytes.org>
Acked-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

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x86, io-apic: Remove !irq_remapped() check from __target_IO_APIC_irq()

This function is only called from default_ioapic_set_affinity()
which is only used when interrupt remapping is disabled
since t

x86, io-apic: Remove !irq_remapped() check from __target_IO_APIC_irq()

This function is only called from default_ioapic_set_affinity()
which is only used when interrupt remapping is disabled
since the introduction of the set_affinity function pointer.
So the check will always evaluate as true and can be
removed.

Signed-off-by: Joerg Roedel <joro@8bytes.org>
Acked-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

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x86, io-apic: Move CONFIG_IRQ_REMAP code out of x86 core

Move all the code to either to the header file
asm/irq_remapping.h or to drivers/iommu/.

Signed-off-by: Joerg Roedel <joro@8bytes.org>
Acked

x86, io-apic: Move CONFIG_IRQ_REMAP code out of x86 core

Move all the code to either to the header file
asm/irq_remapping.h or to drivers/iommu/.

Signed-off-by: Joerg Roedel <joro@8bytes.org>
Acked-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

show more ...

x86, io_apic: Remove irq_remapping_enabled check in setup_timer_IRQ0_pin

This function is only called when irq-remapping is disabled.

Signed-off-by: Joerg Roedel <joro@8bytes.org>
Acked-by: Sebasti

x86, io_apic: Remove irq_remapping_enabled check in setup_timer_IRQ0_pin

This function is only called when irq-remapping is disabled.

Signed-off-by: Joerg Roedel <joro@8bytes.org>
Acked-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

show more ...