linux.git/arch/x86/kernel/nmi.c, branch v3.2 Linux kernel source tree x86, ioapic: Only print ioapic debug information for IRQs belonging to an ioapic chip 2011-11-10T17:31:23+00:00 Mathias Nyman mathias.nyman@linux.intel.com 2011-11-10T13:45:24+00:00 6fd36ba02132c61f67ebefff77fe710bd38ba95a with "apic=verbose" the print_IO_APIC() function tries to print IRQ to pin mappings for every active irq. It assumes chip_data is of type irq_cfg and may cause an oops if not. As the print_IO_APIC() is called from a late_initcall other chained irq chips may already be registered with custom chip_data information, causing an oops. This is the case with intel MID SoC devices with gpio demuxers registered as irq_chips. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> [ -v2: fixed build failure ] Signed-off-by: Ingo Molnar <mingo@elte.hu> 
with "apic=verbose" the print_IO_APIC() function tries to print
IRQ to pin mappings for every active irq. It assumes chip_data
is of type irq_cfg and may cause an oops if not.

As the print_IO_APIC() is called from a late_initcall other
chained irq chips may already be registered with custom
chip_data information, causing an oops. This is the case with
intel MID SoC devices with gpio demuxers registered as irq_chips.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
[ -v2: fixed build failure ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
x86/mrst: Avoid reporting wrong nmi status 2011-11-10T15:21:01+00:00 Jacob Pan jacob.jun.pan@linux.intel.com 2011-11-10T13:43:05+00:00 064a59b6dd1f341cc478c212bb436e3da9cb8d04 Moorestown/Medfield platform does not have port 0x61 to report NMI status, nor does it have external NMI sources. The only NMI sources are from lapic, as results of perf counter overflow or IPI, e.g. NMI watchdog or spin lock debug. Reading port 0x61 on Moorestown will return 0xff which misled NMI handlers to false critical errors such memory parity error. The subsequent ioport access for NMI handling can also cause undefined behavior on Moorestown. This patch allows kernel process NMI due to watchdog or backrace dump without unnecessary hangs. Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> [hand applied] Signed-off-by: Alan Cox <alan@linux.intel.com> 
Moorestown/Medfield platform does not have port 0x61 to report
NMI status, nor does it have external NMI sources. The only NMI
sources are from lapic, as results of perf counter overflow or
IPI, e.g. NMI watchdog or spin lock debug.

Reading port 0x61 on Moorestown will return 0xff which misled
NMI handlers to false critical errors such memory parity error.
The subsequent ioport access for NMI handling can also cause
undefined behavior on Moorestown.

This patch allows kernel process NMI due to watchdog or backrace
dump without unnecessary hangs.

Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
[hand applied]
Signed-off-by: Alan Cox <alan@linux.intel.com>
x86: Fix files explicitly requiring export.h for EXPORT_SYMBOL/THIS_MODULE 2011-10-31T23:30:35+00:00 Paul Gortmaker paul.gortmaker@windriver.com 2011-05-26T16:22:53+00:00 69c60c88eeb364ebf58432f9bc38033522d58767 These files were implicitly getting EXPORT_SYMBOL via device.h which was including module.h, but that will be fixed up shortly. By fixing these now, we can avoid seeing things like: arch/x86/kernel/rtc.c:29: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL’ arch/x86/kernel/pci-dma.c:20: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL’ arch/x86/kernel/e820.c:69: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL_GPL’ [ with input from Randy Dunlap <rdunlap@xenotime.net> and also from Stephen Rothwell <sfr@canb.auug.org.au> ] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> 
These files were implicitly getting EXPORT_SYMBOL via device.h
which was including module.h, but that will be fixed up shortly.

By fixing these now, we can avoid seeing things like:

arch/x86/kernel/rtc.c:29: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL’
arch/x86/kernel/pci-dma.c:20: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL’
arch/x86/kernel/e820.c:69: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL_GPL’

[ with input from Randy Dunlap <rdunlap@xenotime.net> and also
  from Stephen Rothwell <sfr@canb.auug.org.au> ]

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
x86, nmi, drivers: Fix nmi splitup build bug 2011-10-10T04:57:21+00:00 Ingo Molnar mingo@elte.hu 2011-10-06T12:20:27+00:00 d48b0e173715f678698d3678fefd40f2893ce798 nmi.c needs an #include <linux/mca.h>: arch/x86/kernel/nmi.c: In function ‘unknown_nmi_error’: arch/x86/kernel/nmi.c:286:6: error: ‘MCA_bus’ undeclared (first use in this function) arch/x86/kernel/nmi.c:286:6: note: each undeclared identifier is reported only once for each function it appears in Another one is the hpwdt driver: drivers/watchdog/hpwdt.c:507:9: error: ‘NMI_DONE’ undeclared (first use in this function) Signed-off-by: Ingo Molnar <mingo@elte.hu> 
nmi.c needs an #include <linux/mca.h>:

 arch/x86/kernel/nmi.c: In function ‘unknown_nmi_error’:
 arch/x86/kernel/nmi.c:286:6: error: ‘MCA_bus’ undeclared (first use in this function)
 arch/x86/kernel/nmi.c:286:6: note: each undeclared identifier is reported only once for each function it appears in

Another one is the hpwdt driver:

 drivers/watchdog/hpwdt.c:507:9: error: ‘NMI_DONE’ undeclared (first use in this function)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
x86, nmi: Track NMI usage stats 2011-10-10T04:57:06+00:00 Don Zickus dzickus@redhat.com 2011-09-30T19:06:23+00:00 efc3aac5f3d7dbd47fd0a4983979dd4342a78fba Now that the NMI handler are broken into lists, increment the appropriate stats for each list. This allows us to see what is going on when they get printed out in the next patch. Signed-off-by: Don Zickus <dzickus@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1317409584-23662-6-git-send-email-dzickus@redhat.com Signed-off-by: Ingo Molnar <mingo@elte.hu> 
Now that the NMI handler are broken into lists, increment the appropriate
stats for each list.  This allows us to see what is going on when they
get printed out in the next patch.

Signed-off-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1317409584-23662-6-git-send-email-dzickus@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
x86, nmi: Add in logic to handle multiple events and unknown NMIs 2011-10-10T04:57:01+00:00 Don Zickus dzickus@redhat.com 2011-09-30T19:06:22+00:00 b227e23399dc59977aa42c49bd668bdab7a61812 Previous patches allow the NMI subsystem to process multipe NMI events in one NMI. As previously discussed this can cause issues when an event triggered another NMI but is processed in the current NMI. This causes the next NMI to go unprocessed and become an 'unknown' NMI. To handle this, we first have to flag whether or not the NMI handler handled more than one event or not. If it did, then there exists a chance that the next NMI might be already processed. Once the NMI is flagged as a candidate to be swallowed, we next look for a back-to-back NMI condition. This is determined by looking at the %rip from pt_regs. If it is the same as the previous NMI, it is assumed the cpu did not have a chance to jump back into a non-NMI context and execute code and instead handled another NMI. If both of those conditions are true then we will swallow any unknown NMI. There still exists a chance that we accidentally swallow a real unknown NMI, but for now things seem better. An optimization has also been added to the nmi notifier rountine. Because x86 can latch up to one NMI while currently processing an NMI, we don't have to worry about executing _all_ the handlers in a standalone NMI. The idea is if multiple NMIs come in, the second NMI will represent them. For those back-to-back NMI cases, we have the potentail to drop NMIs. Therefore only execute all the handlers in the second half of a detected back-to-back NMI. Signed-off-by: Don Zickus <dzickus@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1317409584-23662-5-git-send-email-dzickus@redhat.com Signed-off-by: Ingo Molnar <mingo@elte.hu> 
Previous patches allow the NMI subsystem to process multipe NMI events
in one NMI.  As previously discussed this can cause issues when an event
triggered another NMI but is processed in the current NMI.  This causes the
next NMI to go unprocessed and become an 'unknown' NMI.

To handle this, we first have to flag whether or not the NMI handler handled
more than one event or not.  If it did, then there exists a chance that
the next NMI might be already processed.  Once the NMI is flagged as a
candidate to be swallowed, we next look for a back-to-back NMI condition.

This is determined by looking at the %rip from pt_regs.  If it is the same
as the previous NMI, it is assumed the cpu did not have a chance to jump
back into a non-NMI context and execute code and instead handled another NMI.

If both of those conditions are true then we will swallow any unknown NMI.

There still exists a chance that we accidentally swallow a real unknown NMI,
but for now things seem better.

An optimization has also been added to the nmi notifier rountine.  Because x86
can latch up to one NMI while currently processing an NMI, we don't have to
worry about executing _all_ the handlers in a standalone NMI.  The idea is
if multiple NMIs come in, the second NMI will represent them.  For those
back-to-back NMI cases, we have the potentail to drop NMIs.  Therefore only
execute all the handlers in the second half of a detected back-to-back NMI.

Signed-off-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1317409584-23662-5-git-send-email-dzickus@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
x86, nmi: Wire up NMI handlers to new routines 2011-10-10T04:56:57+00:00 Don Zickus dzickus@redhat.com 2011-09-30T19:06:21+00:00 9c48f1c629ecfa114850c03f875c6691003214de Just convert all the files that have an nmi handler to the new routines. Most of it is straight forward conversion. A couple of places needed some tweaking like kgdb which separates the debug notifier from the nmi handler and mce removes a call to notify_die. [Thanks to Ying for finding out the history behind that mce call https://lkml.org/lkml/2010/5/27/114 And Boris responding that he would like to remove that call because of it https://lkml.org/lkml/2011/9/21/163] The things that get converted are the registeration/unregistration routines and the nmi handler itself has its args changed along with code removal to check which list it is on (most are on one NMI list except for kgdb which has both an NMI routine and an NMI Unknown routine). Signed-off-by: Don Zickus <dzickus@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Corey Minyard <minyard@acm.org> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Robert Richter <robert.richter@amd.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Corey Minyard <minyard@acm.org> Cc: Jack Steiner <steiner@sgi.com> Link: http://lkml.kernel.org/r/1317409584-23662-4-git-send-email-dzickus@redhat.com Signed-off-by: Ingo Molnar <mingo@elte.hu> 
Just convert all the files that have an nmi handler to the new routines.
Most of it is straight forward conversion.  A couple of places needed some
tweaking like kgdb which separates the debug notifier from the nmi handler
and mce removes a call to notify_die.

[Thanks to Ying for finding out the history behind that mce call

https://lkml.org/lkml/2010/5/27/114

And Boris responding that he would like to remove that call because of it

https://lkml.org/lkml/2011/9/21/163]

The things that get converted are the registeration/unregistration routines
and the nmi handler itself has its args changed along with code removal
to check which list it is on (most are on one NMI list except for kgdb
which has both an NMI routine and an NMI Unknown routine).

Signed-off-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Corey Minyard <minyard@acm.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Corey Minyard <minyard@acm.org>
Cc: Jack Steiner <steiner@sgi.com>
Link: http://lkml.kernel.org/r/1317409584-23662-4-git-send-email-dzickus@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
x86, nmi: Create new NMI handler routines 2011-10-10T04:56:52+00:00 Don Zickus dzickus@redhat.com 2011-09-30T19:06:20+00:00 c9126b2ee8adb9235941cedbf558d39a9e65642d The NMI handlers used to rely on the notifier infrastructure. This worked great until we wanted to support handling multiple events better. One of the key ideas to the nmi handling is to process _all_ the handlers for each NMI. The reason behind this switch is because NMIs are edge triggered. If enough NMIs are triggered, then they could be lost because the cpu can only latch at most one NMI (besides the one currently being processed). In order to deal with this we have decided to process all the NMI handlers for each NMI. This allows the handlers to determine if they recieved an event or not (the ones that can not determine this will be left to fend for themselves on the unknown NMI list). As a result of this change it is now possible to have an extra NMI that was destined to be received for an already processed event. Because the event was processed in the previous NMI, this NMI gets dropped and becomes an 'unknown' NMI. This of course will cause printks that scare people. However, we prefer to have extra NMIs as opposed to losing NMIs and as such are have developed a basic mechanism to catch most of them. That will be a later patch. To accomplish this idea, I unhooked the nmi handlers from the notifier routines and created a new mechanism loosely based on doIRQ. The reason for this is the notifier routines have a couple of shortcomings. One we could't guarantee all future NMI handlers used NOTIFY_OK instead of NOTIFY_STOP. Second, we couldn't keep track of the number of events being handled in each routine (most only handle one, perf can handle more than one). Third, I wanted to eventually display which nmi handlers are registered in the system in /proc/interrupts to help see who is generating NMIs. The patch below just implements the new infrastructure but doesn't wire it up yet (that is the next patch). Its design is based on doIRQ structs and the atomic notifier routines. So the rcu stuff in the patch isn't entirely untested (as the notifier routines have soaked it) but it should be double checked in case I copied the code wrong. Signed-off-by: Don Zickus <dzickus@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1317409584-23662-3-git-send-email-dzickus@redhat.com Signed-off-by: Ingo Molnar <mingo@elte.hu> 
The NMI handlers used to rely on the notifier infrastructure.  This worked
great until we wanted to support handling multiple events better.

One of the key ideas to the nmi handling is to process _all_ the handlers for
each NMI.  The reason behind this switch is because NMIs are edge triggered.
If enough NMIs are triggered, then they could be lost because the cpu can
only latch at most one NMI (besides the one currently being processed).

In order to deal with this we have decided to process all the NMI handlers
for each NMI.  This allows the handlers to determine if they recieved an
event or not (the ones that can not determine this will be left to fend
for themselves on the unknown NMI list).

As a result of this change it is now possible to have an extra NMI that
was destined to be received for an already processed event.  Because the
event was processed in the previous NMI, this NMI gets dropped and becomes
an 'unknown' NMI.  This of course will cause printks that scare people.

However, we prefer to have extra NMIs as opposed to losing NMIs and as such
are have developed a basic mechanism to catch most of them.  That will be
a later patch.

To accomplish this idea, I unhooked the nmi handlers from the notifier
routines and created a new mechanism loosely based on doIRQ.  The reason
for this is the notifier routines have a couple of shortcomings.  One we
could't guarantee all future NMI handlers used NOTIFY_OK instead of
NOTIFY_STOP.  Second, we couldn't keep track of the number of events being
handled in each routine (most only handle one, perf can handle more than one).
Third, I wanted to eventually display which nmi handlers are registered in
the system in /proc/interrupts to help see who is generating NMIs.

The patch below just implements the new infrastructure but doesn't wire it up
yet (that is the next patch).  Its design is based on doIRQ structs and the
atomic notifier routines.  So the rcu stuff in the patch isn't entirely untested
(as the notifier routines have soaked it) but it should be double checked in
case I copied the code wrong.

Signed-off-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1317409584-23662-3-git-send-email-dzickus@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
x86, nmi: Split out nmi from traps.c 2011-10-10T04:56:47+00:00 Don Zickus dzickus@redhat.com 2011-09-30T19:06:19+00:00 1d48922c14b6363f6d5febb12464d804bb5cc53f The nmi stuff is changing a lot and adding more functionality. Split it out from the traps.c file so it doesn't continue to pollute that file. This makes it easier to find and expand all the future nmi related work. No real functional changes here. Signed-off-by: Don Zickus <dzickus@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1317409584-23662-2-git-send-email-dzickus@redhat.com Signed-off-by: Ingo Molnar <mingo@elte.hu> 
The nmi stuff is changing a lot and adding more functionality.  Split it
out from the traps.c file so it doesn't continue to pollute that file.

This makes it easier to find and expand all the future nmi related work.

No real functional changes here.

Signed-off-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1317409584-23662-2-git-send-email-dzickus@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
x86, apic: move APIC drivers to arch/x86/kernel/apic/* 2009-02-17T17:17:36+00:00 Ingo Molnar mingo@elte.hu 2009-02-17T17:09:24+00:00 f62bae5009c1ba596cd475cafbc83e0570a36e26 arch/x86/kernel/ is getting a bit crowded, and the APIC drivers are scattered into various different files. Move them to arch/x86/kernel/apic/*, and also remove the 'gen' prefix from those which had it. Also move APIC related functionality: the IO-APIC driver, the NMI and the IPI code. Signed-off-by: Ingo Molnar <mingo@elte.hu> 
arch/x86/kernel/ is getting a bit crowded, and the APIC
drivers are scattered into various different files.

Move them to arch/x86/kernel/apic/*, and also remove
the 'gen' prefix from those which had it.

Also move APIC related functionality: the IO-APIC driver,
the NMI and the IPI code.

Signed-off-by: Ingo Molnar <mingo@elte.hu>