History log of /openbmc/linux/arch/x86/include/asm/apic.h (Results 126 – 150 of 430)
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# 659006bf 15-Jan-2015 Thomas Gleixner <tglx@linutronix.de>

x86/x2apic: Split enable and setup function

enable_x2apic() is a convoluted unreadable mess because it is used for
both enablement in early boot and for setup in cpu_init().

Split the code into x2a

x86/x2apic: Split enable and setup function

enable_x2apic() is a convoluted unreadable mess because it is used for
both enablement in early boot and for setup in cpu_init().

Split the code into x2apic_enable() for enablement and x2apic_setup()
for setup of (secondary cpus). Make use of the new state tracking to
simplify the logic.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Link: http://lkml.kernel.org/r/20150115211703.129287153@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

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# 44e25ff9 15-Jan-2015 Thomas Gleixner <tglx@linutronix.de>

x86/x2apic: Disable x2apic from nox2apic setup

There is no point in postponing the hardware disablement of x2apic. It
can be disabled right away in the nox2apic setup function.

Disable it right awa

x86/x2apic: Disable x2apic from nox2apic setup

There is no point in postponing the hardware disablement of x2apic. It
can be disabled right away in the nox2apic setup function.

Disable it right away and set the state to DISABLED . This allows to
remove all the nox2apic conditionals all over the place.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Link: http://lkml.kernel.org/r/20150115211703.051214090@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

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# 55eae7de 15-Jan-2015 Thomas Gleixner <tglx@linutronix.de>

x86/x2apic: Move code in conditional region

No point in having try_to_enable_x2apic() outside of the
CONFIG_X86_X2APIC section and having inline functions and more ifdefs
to deal with it. Move the c

x86/x2apic: Move code in conditional region

No point in having try_to_enable_x2apic() outside of the
CONFIG_X86_X2APIC section and having inline functions and more ifdefs
to deal with it. Move the code into the existing ifdef section and
remove the inline cruft.

Fixup the printk about not enabling interrupt remapping as suggested
by Boris.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Link: http://lkml.kernel.org/r/20150115211702.795388613@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

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# d524165c 15-Jan-2015 Thomas Gleixner <tglx@linutronix.de>

x86/apic: Check x2apic early

No point in delaying the x2apic detection for the CONFIG_X86_X2APIC=n
case to enable_IR_x2apic(). We rather detect that before we try to
setup anything there.

Signed-of

x86/apic: Check x2apic early

No point in delaying the x2apic detection for the CONFIG_X86_X2APIC=n
case to enable_IR_x2apic(). We rather detect that before we try to
setup anything there.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Link: http://lkml.kernel.org/r/20150115211702.702479404@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

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# 2ca5b404 15-Jan-2015 Thomas Gleixner <tglx@linutronix.de>

x86/ioapic: Check x2apic really

The x2apic_preenabled flag is just a horrible hack and if X2APIC
support is disabled it does not reflect the actual hardware
state. Check the hardware instead.

Signe

x86/ioapic: Check x2apic really

The x2apic_preenabled flag is just a horrible hack and if X2APIC
support is disabled it does not reflect the actual hardware
state. Check the hardware instead.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Link: http://lkml.kernel.org/r/20150115211702.541280622@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

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# 81a46dd8 15-Jan-2015 Thomas Gleixner <tglx@linutronix.de>

x86/apic: Make x2apic_mode depend on CONFIG_X86_X2APIC

No point in having a static variable around which is always 0. Let the
compiler optimize code out if disabled.

Signed-off-by: Thomas Gleixner

x86/apic: Make x2apic_mode depend on CONFIG_X86_X2APIC

No point in having a static variable around which is always 0. Let the
compiler optimize code out if disabled.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/20150115211702.363274310@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

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# 8d806960 15-Jan-2015 Thomas Gleixner <tglx@linutronix.de>

x86/apic: Avoid open coded x2apic detection

enable_IR_x2apic() grew a open coded x2apic detection. Implement a
proper helper function which shares the code with the already existing
x2apic_enabled()

x86/apic: Avoid open coded x2apic detection

enable_IR_x2apic() grew a open coded x2apic detection. Implement a
proper helper function which shares the code with the already existing
x2apic_enabled().

Made it use rdmsrl_safe as suggested by Boris.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/20150115211702.285038186@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

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Revision tags: v3.19-rc4, v3.19-rc3, v3.19-rc2, v3.19-rc1, v3.18, v3.18-rc7, v3.18-rc6, v3.18-rc5, v3.18-rc4, v3.18-rc3, v3.18-rc2, v3.18-rc1, v3.17, v3.17-rc7, v3.17-rc6, v3.17-rc5, v3.17-rc4, v3.17-rc3, v3.17-rc2, v3.17-rc1, v3.16
# 2f078b9c 31-Jul-2014 David Rientjes <rientjes@google.com>

x86, apic: Remove enable_apic_mode callback

The enable_apic_mode() apic callback is never called, so remove it.

Signed-off-by: David Rientjes <rientjes@google.com>
Link: http://lkml.kernel.org/r/al

x86, apic: Remove enable_apic_mode callback

The enable_apic_mode() apic callback is never called, so remove it.

Signed-off-by: David Rientjes <rientjes@google.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1407302352320.17503@chino.kir.corp.google.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

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# 11a8318e 31-Jul-2014 David Rientjes <rientjes@google.com>

x86, apic: Remove setup_portio_remap callback

Since commit b5660ba76b41 ("x86, platforms: Remove NUMAQ") removed NUMAQ,
the setup_portio_remap() apic callback has been obsolete. Remove it.

Signed-

x86, apic: Remove setup_portio_remap callback

Since commit b5660ba76b41 ("x86, platforms: Remove NUMAQ") removed NUMAQ,
the setup_portio_remap() apic callback has been obsolete. Remove it.

Signed-off-by: David Rientjes <rientjes@google.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1407302351480.17503@chino.kir.corp.google.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

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# e76661ba 31-Jul-2014 David Rientjes <rientjes@google.com>

x86, apic: Remove multi_timer_check callback

Since commit b5660ba76b41 ("x86, platforms: Remove NUMAQ") removed NUMAQ,
the multi_timer_check() apic callback has been obsolete. Remove it.

Signed-of

x86, apic: Remove multi_timer_check callback

Since commit b5660ba76b41 ("x86, platforms: Remove NUMAQ") removed NUMAQ,
the multi_timer_check() apic callback has been obsolete. Remove it.

Signed-off-by: David Rientjes <rientjes@google.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1407302351120.17503@chino.kir.corp.google.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

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# 658ffd7e 31-Jul-2014 David Rientjes <rientjes@google.com>

x86, apic: Remove check_apicid_present callback

The check_apicid_present() apic callback is never called, so remove it
and functions that implement it.

Signed-off-by: David Rientjes <rientjes@googl

x86, apic: Remove check_apicid_present callback

The check_apicid_present() apic callback is never called, so remove it
and functions that implement it.

Signed-off-by: David Rientjes <rientjes@google.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1407302350160.17503@chino.kir.corp.google.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

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# c460b5d3 31-Jul-2014 David Rientjes <rientjes@google.com>

x86, apic: Remove mps_oem_check callback

Since commit b5660ba76b41 ("x86, platforms: Remove NUMAQ") removed NUMAQ,
the mps_oem_check() apic callback has been obsolete. Remove it.

This allows gener

x86, apic: Remove mps_oem_check callback

Since commit b5660ba76b41 ("x86, platforms: Remove NUMAQ") removed NUMAQ,
the mps_oem_check() apic callback has been obsolete. Remove it.

This allows generic_mps_oem_check() to be removed as well.

Signed-off-by: David Rientjes <rientjes@google.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1407302349390.17503@chino.kir.corp.google.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

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# 300eddf9 31-Jul-2014 David Rientjes <rientjes@google.com>

x86, apic: Remove smp_callin_clear_local_apic callback

Since commit b5660ba76b41 ("x86, platforms: Remove NUMAQ") removed NUMAQ,
the smp_callin_clear_local_apic() apic callback has been obsolete.
Re

x86, apic: Remove smp_callin_clear_local_apic callback

Since commit b5660ba76b41 ("x86, platforms: Remove NUMAQ") removed NUMAQ,
the smp_callin_clear_local_apic() apic callback has been obsolete.
Remove it.

Signed-off-by: David Rientjes <rientjes@google.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1407302349040.17503@chino.kir.corp.google.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

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# 6ab1b27c 31-Jul-2014 David Rientjes <rientjes@google.com>

x86, apic: Replace trampoline physical addresses with defaults

The trampoline_phys_{high,low} members of struct apic are always
initialized to DEFAULT_TRAMPOLINE_PHYS_HIGH and TRAMPOLINE_PHYS_LOW,
r

x86, apic: Replace trampoline physical addresses with defaults

The trampoline_phys_{high,low} members of struct apic are always
initialized to DEFAULT_TRAMPOLINE_PHYS_HIGH and TRAMPOLINE_PHYS_LOW,
respectively. Hardwire the constants and remove the unneeded members.

Signed-off-by: David Rientjes <rientjes@google.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1407302348330.17503@chino.kir.corp.google.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

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# 80a26703 31-Jul-2014 David Rientjes <rientjes@google.com>

x86, apic: Remove x86_32_numa_cpu_node callback

Since commit b5660ba76b41 ("x86, platforms: Remove NUMAQ") removed NUMAQ,
the x86_32_numa_cpu_node() apic callback has been obsolete. Remove it.

Sig

x86, apic: Remove x86_32_numa_cpu_node callback

Since commit b5660ba76b41 ("x86, platforms: Remove NUMAQ") removed NUMAQ,
the x86_32_numa_cpu_node() apic callback has been obsolete. Remove it.

Signed-off-by: David Rientjes <rientjes@google.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1407302348060.17503@chino.kir.corp.google.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

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Revision tags: v3.16-rc7, v3.16-rc6, v3.16-rc5, v3.16-rc4, v3.16-rc3
# 411cf9ee 29-Jun-2014 Oren Twaig <oren@scalemp.com>

x86, vsmp: Remove is_vsmp_box() from apic_is_clustered_box()

When a vSMP Foundation box is detected, the function apic_cluster_num() counts
the number of APIC clusters found. If more than one found,

x86, vsmp: Remove is_vsmp_box() from apic_is_clustered_box()

When a vSMP Foundation box is detected, the function apic_cluster_num() counts
the number of APIC clusters found. If more than one found, a multi board
configuration is assumed, and TSC marked as unstable. This behavior is
incorrect as vSMP Foundation may use processors from single node only, attached
to memory of other nodes - and such node may have more than one APIC cluster
(typically any recent intel box has more than single APIC_CLUSTERID(x)).

To fix this, we simply remove the code which detects a vSMP Foundation box and
affects apic_is_clusted_box() return value. This can be done because later the
kernel checks by itself if the TSC is stable using the
check_tsc_sync_[source|target]() functions and marks TSC as unstable if needed.

Acked-by: Shai Fultheim <shai@scalemp.com>
Signed-off-by: Oren Twaig <oren@scalemp.com>
Link: http://lkml.kernel.org/r/1404036068-11674-1-git-send-email-oren@scalemp.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

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Revision tags: v3.16-rc2, v3.16-rc1
# a491cc90 09-Jun-2014 Jiang Liu <jiang.liu@linux.intel.com>

x86, mpparse: Simplify arch/x86/include/asm/mpspec.h

Simplify arch/x86/include/asm/mpspec.h by
1) Change max_physical_apicid to static as it's only used in apic.c.
2) Kill declaration of mpc_default

x86, mpparse: Simplify arch/x86/include/asm/mpspec.h

Simplify arch/x86/include/asm/mpspec.h by
1) Change max_physical_apicid to static as it's only used in apic.c.
2) Kill declaration of mpc_default_type, it's never defined.
3) Delete default_acpi_madt_oem_check(), it has already been declared
in apic.h.
4) Make default_acpi_madt_oem_check() depends on CONFIG_X86_LOCAL_APIC
instead of CONFIG_X86_64 to support i386.
5) Change mp_override_legacy_irq(), mp_config_acpi_legacy_irqs() and
mp_register_gsi() as static because they are only used in acpi/boot.c.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@linux.intel.com>
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: Len Brown <len.brown@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1402302011-23642-4-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

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# 9b13a93d 17-Jun-2014 Borislav Petkov <bp@suse.de>

x86, cpufeature: Convert more "features" to bugs

X86_FEATURE_FXSAVE_LEAK, X86_FEATURE_11AP and
X86_FEATURE_CLFLUSH_MONITOR are not really features but synthetic bits
we use for applying different bu

x86, cpufeature: Convert more "features" to bugs

X86_FEATURE_FXSAVE_LEAK, X86_FEATURE_11AP and
X86_FEATURE_CLFLUSH_MONITOR are not really features but synthetic bits
we use for applying different bug workarounds. Call them what they
really are, and make sure they get the proper cross-CPU behavior (OR
rather than AND).

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1403042783-23278-1-git-send-email-bp@alien8.de
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

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Revision tags: v3.15, v3.15-rc8, v3.15-rc7, v3.15-rc6, v3.15-rc5, v3.15-rc4, v3.15-rc3, v3.15-rc2, v3.15-rc1, v3.14, v3.14-rc8, v3.14-rc7, v3.14-rc6, v3.14-rc5, v3.14-rc4, v3.14-rc3, v3.14-rc2
# dc9788f4 05-Feb-2014 David Rientjes <rientjes@google.com>

x86/apic: Always define nox2apic and define it as initdata

The "nox2apic" variable can be defined as __initdata since it is
only used for bootstrap. It can now unconditionally be defined
since it w

x86/apic: Always define nox2apic and define it as initdata

The "nox2apic" variable can be defined as __initdata since it is
only used for bootstrap. It can now unconditionally be defined
since it will later be freed.

At the same time, it is also better off as a bool.

Signed-off-by: David Rientjes <rientjes@google.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1402042354380.7839@chino.kir.corp.google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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# 6d498983 05-Feb-2014 David Rientjes <rientjes@google.com>

x86/apic: Remove unused function prototypes

Some function prototypes declared in asm/apic.h are never
defined, so remove them.

Signed-off-by: David Rientjes <rientjes@google.com>
Reviewed-by: Thoma

x86/apic: Remove unused function prototypes

Some function prototypes declared in asm/apic.h are never
defined, so remove them.

Signed-off-by: David Rientjes <rientjes@google.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1402042354210.7839@chino.kir.corp.google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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# 465822cf 05-Feb-2014 David Rientjes <rientjes@google.com>

x86/apic: Switch wait_for_init_deassert() to a bool flag

Now that there is only a single wait_for_init_deassert()
function, just convert the member of struct apic to a bool to
determine whether we n

x86/apic: Switch wait_for_init_deassert() to a bool flag

Now that there is only a single wait_for_init_deassert()
function, just convert the member of struct apic to a bool to
determine whether we need to wait for init_deassert to become
non-zero.

There are no more callers of default_wait_for_init_deassert(),
so fold it into the caller.

Signed-off-by: David Rientjes <rientjes@google.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1402042354010.7839@chino.kir.corp.google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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# d3c63ae1 05-Feb-2014 David Rientjes <rientjes@google.com>

x86/apic: Only use default_wait_for_init_deassert()

es7000_wait_for_init_deassert() is functionally equivalent to
default_wait_for_init_deassert(), so remove the duplicate code
and use only a single

x86/apic: Only use default_wait_for_init_deassert()

es7000_wait_for_init_deassert() is functionally equivalent to
default_wait_for_init_deassert(), so remove the duplicate code
and use only a single function.

Signed-off-by: David Rientjes <rientjes@google.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1402042353030.7839@chino.kir.corp.google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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Revision tags: v3.14-rc1, v3.13, v3.13-rc8, v3.13-rc7, v3.13-rc6, v3.13-rc5, v3.13-rc4, v3.13-rc3, v3.13-rc2, v3.13-rc1, v3.12, v3.12-rc7, v3.12-rc6, v3.12-rc5, v3.12-rc4, v3.12-rc3, v3.12-rc2, v3.12-rc1, v3.11, v3.11-rc7
# 17405453 20-Aug-2013 Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>

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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Revision tags: v3.11-rc6, v3.11-rc5, v3.11-rc4, v3.11-rc3, v3.11-rc2, v3.11-rc1, v3.10, v3.10-rc7
# eddc0e92 20-Jun-2013 Seiji Aguchi <seiji.aguchi@hds.com>

x86, trace: Introduce entering/exiting_irq()

When implementing tracepoints in interrupt handers, if the tracepoints are
simply added in the performance sensitive path of interrupt handers,
it may ca

x86, trace: Introduce entering/exiting_irq()

When implementing tracepoints in interrupt handers, if the tracepoints are
simply added in the performance sensitive path of interrupt handers,
it may cause potential performance problem due to the time penalty.

To solve the problem, an idea is to prepare non-trace/trace irq handers and
switch their IDTs at the enabling/disabling time.

So, let's introduce entering_irq()/exiting_irq() for pre/post-
processing of each irq handler.

A way to use them is as follows.

Non-trace irq handler:
smp_irq_handler()
{
entering_irq(); /* pre-processing of this handler */
__smp_irq_handler(); /*
* common logic between non-trace and trace handlers
* in a vector.
*/
exiting_irq(); /* post-processing of this handler */

}

Trace irq_handler:
smp_trace_irq_handler()
{
entering_irq(); /* pre-processing of this handler */
trace_irq_entry(); /* tracepoint for irq entry */
__smp_irq_handler(); /*
* common logic between non-trace and trace handlers
* in a vector.
*/
trace_irq_exit(); /* tracepoint for irq exit */
exiting_irq(); /* post-processing of this handler */

}

If tracepoints can place outside entering_irq()/exiting_irq() as follows,
it looks cleaner.

smp_trace_irq_handler()
{
trace_irq_entry();
smp_irq_handler();
trace_irq_exit();
}

But it doesn't work.
The problem is with irq_enter/exit() being called. They must be called before
trace_irq_enter/exit(), because of the rcu_irq_enter() must be called before
any tracepoints are used, as tracepoints use rcu to synchronize.

As a possible alternative, we may be able to call irq_enter() first as follows
if irq_enter() can nest.

smp_trace_irq_hander()
{
irq_entry();
trace_irq_entry();
smp_irq_handler();
trace_irq_exit();
irq_exit();
}

But it doesn't work, either.
If irq_enter() is nested, it may have a time penalty because it has to check if it
was already called or not. The time penalty is not desired in performance sensitive
paths even if it is tiny.

Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Link: http://lkml.kernel.org/r/51C3238D.9040706@hds.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>

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Revision tags: v3.10-rc6, v3.10-rc5, v3.10-rc4, v3.10-rc3, v3.10-rc2, v3.10-rc1, v3.9, v3.9-rc8, v3.9-rc7, v3.9-rc6, v3.9-rc5, v3.9-rc4, v3.9-rc3, v3.9-rc2, v3.9-rc1, v3.8, v3.8-rc7, v3.8-rc6, v3.8-rc5, v3.8-rc4, v3.8-rc3, v3.8-rc2, v3.8-rc1, v3.7, v3.7-rc8, v3.7-rc7, v3.7-rc6, v3.7-rc5, v3.7-rc4, v3.7-rc3, v3.7-rc2, v3.7-rc1
# 75fdd155 04-Oct-2012 Andi Kleen <ak@linux.intel.com>

sections: fix section conflicts in arch/x86

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.co

sections: fix section conflicts in arch/x86

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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