Commit Graph

7303 Commits

Author SHA1 Message Date
Huang Ying
1b2797dcc9 x86, mce: improve mce_get_rip
Assume IP on the stack is valid when either EIPV or RIPV are set.
This influences whether the machine check exception handler decides
to return or panic.

This fixes a test case in the mce-test suite and is more compliant
to the specification.

This currently only makes a difference in a artificial testing
scenario with the mce-test test suite.

Also in addition do not force the EIPV to be valid with the exact
register MSRs, and keep in trust the CS value on stack even if MSR
is available.

[AK: combination of patches from Huang Ying and Hidetoshi Seto, with
new description by me]
[add some description, no code changed - HS]

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-06-03 14:45:33 -07:00
Andi Kleen
ac9603754d x86, mce: make non Monarch panic message "Fatal machine check" too
... instead of "Machine check". This is for consistency with the Monarch
panic message.

Based on a report from Ying Huang.

v2: But add a descriptive postfix so that the test suite can distingush.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-06-03 14:45:12 -07:00
Andi Kleen
3c0797925f x86, mce: switch x86 machine check handler to Monarch election.
On Intel platforms machine check exceptions are always broadcast to
all CPUs.  This patch makes the machine check handler synchronize all
these machine checks, elect a Monarch to handle the event and collect
the worst event from all CPUs and then process it first.

This has some advantages:

- When there is a truly data corrupting error the system panics as
  quickly as possible. This improves containment of corrupted
  data and makes sure the corrupted data never hits stable storage.

- The panics are synchronized and do not reenter the panic code
  on multiple CPUs (which currently does not handle this well).

- All the errors are reported. Currently it often happens that
  another CPU happens to do the panic first, but reports useless
  information (empty machine check) because the real error
  happened on another CPU which came in later.
  This is a big advantage on Nehalem where the 8 threads per CPU
  lead to often the wrong CPU winning the race and dumping
  useless information on a machine check.  The problem also occurs
  in a less severe form on older CPUs.

- The system can detect when no CPUs detected a machine check
  and shut down the system.  This can happen when one CPU is so
  badly hung that that it cannot process a machine check anymore
  or when some external agent wants to stop the system by
  asserting the machine check pin.  This follows Intel hardware
  recommendations.

- This matches the recommended error model by the CPU designers.

- The events can be output in true severity order

- When a panic happens on another CPU it makes sure to be actually
  be able to process the stop IPI by enabling interrupts.

The code is extremly careful to handle timeouts while waiting
for other CPUs. It can't rely on the normal timing mechanisms
(jiffies, ktime_get) because of its asynchronous/lockless nature,
so it uses own timeouts using ndelay() and a "SPINUNIT"

The timeout is configurable. By default it waits for upto one
second for the other CPUs.  This can be also disabled.

From some informal testing AMD systems do not see to broadcast
machine checks, so right now it's always disabled by default on
non Intel CPUs or also on very old Intel systems.

Includes fixes from Ying Huang
Fixed a "ecception" in a comment (H.Seto)
Moved global_nwo reset later based on suggestion from H.Seto
v2: Avoid duplicate messages

[ Impact: feature, fixes long standing problems. ]

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-06-03 14:45:12 -07:00
Andi Kleen
f94b61c2c9 x86, mce: implement panic synchronization
In some circumstances multiple CPUs can enter mce_panic() in parallel.
This gives quite confused output because they will all dump the same
machine check buffer.

The other problem is that they would all panic in parallel, but not
process each other's shutdown IPIs because interrupts are disabled.

Detect this situation early on in mce_panic(). On the first CPU
entering will do the panic, the others will just wait to be killed.

For paranoia reasons in case the other CPU dies during the MCE I added
a 5 seconds timeout. If it expires each CPU will panic on its own again.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-06-03 14:45:12 -07:00
Andi Kleen
ccc3c3192a x86, mce: implement bootstrapping for machine check wakeups
Machine checks support waking up the mcelog daemon quickly.

The original wake up code for this was pretty ugly, relying on
a idle notifier and a special process flag. The reason it did
it this way is that the machine check handler is not subject
to normal interrupt locking rules so it's not safe
to call wake_up().  Instead it set a process flag
and then either did the wakeup in the syscall return
or in the idle notifier.

This patch adds a new "bootstraping" method as replacement.

The idea is that the handler checks if it's in a state where
it is unsafe to call wake_up(). If it's safe it calls it directly.
When it's not safe -- that is it interrupted in a critical
section with interrupts disables -- it uses a new "self IPI" to trigger
an IPI to its own CPU. This can be done safely because IPI
triggers are atomic with some care. The IPI is raised
once the interrupts are reenabled and can then safely call
wake_up().

When APICs are disabled the event is just queued and will be picked up
eventually by the next polling timer. I think that's a reasonable
compromise, since it should only happen quite rarely.

Contains fixes from Ying Huang.

[ solve conflict on irqinit, make it work on 32bit (entry_arch.h) - HS ]

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-06-03 14:44:05 -07:00
Andi Kleen
bd19a5e6b7 x86, mce: check early in exception handler if panic is needed
The exception handler should behave differently if the exception is
fatal versus one that can be returned from.  In the first case it should
never clear any registers because these need to be preserved
for logging after the next boot. Otherwise it should clear them
on each CPU step by step so that other CPUs sharing the same bank don't
see duplicate events. Otherwise we risk reporting events multiple
times on any CPUs which have shared machine check banks, which
is a common problem on Intel Nehalem which has both SMT (two
CPU threads sharing banks) and shared machine check banks in the uncore.

Determine early in a special pass if any event requires a panic.
This uses the mce_severity() function added earlier.

This is needed for the next patch.

Also fixes a problem together with an earlier patch
that corrected events weren't logged on a fatal MCE.

[ Impact: Feature ]

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-06-03 14:40:39 -07:00
Andi Kleen
817f32d02a x86, mce: add table driven machine check grading
The machine check grading (as in deciding what should be done for a given
register value) has to be done multiple times soon and it's also getting
more complicated.
So it makes sense to consolidate it into a single function. To get smaller
and more straight forward and possibly more extensible code I opted towards
a new table driven method. The various rules are put into a table
when is then executed by a very simple interpreter.

The grading engine is in a new file mce-severity.c. I also added a private
include file mce-internal.h, because mce.h is already a bit too cluttered.

This is dead code right now, but will be used in followon patches.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-06-03 14:40:39 -07:00
Andi Kleen
a0189c70e5 x86, mce: remove TSC print heuristic
Previously mce_panic used a simple heuristic to avoid printing
old so far unreported machine check events on a mce panic. This worked
by comparing the TSC value at the start of the machine check handler
with the event time stamp and only printing newer ones.

This has a couple of issues, in particular on systems where the TSC
is not fully synchronized between CPUs it could lose events or print
old ones.

It is also problematic with full system synchronization as it is
added by the next patch.

Remove the TSC heuristic and instead replace it with a simple heuristic
to print corrected errors first and after that uncorrected errors
and finally the worst machine check as determined by the machine
check handler.

This simplifies the code because there is no need to pass the
original TSC value around.

Contains fixes from Ying Huang

[ Impact: bug fix, cleanup ]

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Ying Huang <ying.huang@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-06-03 14:40:39 -07:00
Andi Kleen
de8a84d85a x86, mce: log corrected errors when panicing
Normally the machine check handler ignores corrected errors and leaves
them to machine_check_poll(). But when panicing mcp won't run, so
log all errors.

Note: this can still miss some cases until the "early no way out"
patch later is applied too.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-06-03 14:40:39 -07:00
Andi Kleen
8ee08347c1 x86, mce: extend struct mce user interface with more information.
Experience has shown that struct mce which is used to pass an machine
check to the user space daemon currently a few limitations.  Also some
data which is useful to print at panic level is also missing.

This patch addresses most of them. The same information is also
printed out together with mce panic.

struct mce can be painlessly extended in a compatible way, the mcelog
user space code just ignores additional fields with a warning.

- It doesn't provide a wall time timestamp. There have been a few
  complaints about that. Fix that by adding a 64bit time_t

- It doesn't provide the exact CPU identification. This makes
  it awkward for mcelog to decode the event correctly, especially
  when there are variations in the supported MCE codes on different
  CPU models or when mcelog is running on a different host after a panic.
  Previously the administrator had to specify the correct CPU
  when mcelog ran on a different host, but with the more variation
  in machine checks now it's better to auto detect that.
  It's also useful for more detailed analysis of CPU events.
  Pass CPUID 1.EAX and the cpu vendor (as encoded in processor.h) instead.

- Socket ID and initial APIC ID are useful to report because they
  allow to identify the failing CPU in some (not all) cases.
  This is also especially useful for the panic situation.
  This addresses one of the complaints from Thomas Gleixner earlier.

- The MCG capabilities MSR needs to be reported for some advanced
  error processing in mcelog

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-06-03 14:40:38 -07:00
Andi Kleen
d620c67fb9 x86, mce: support more than 256 CPUs in struct mce
The old struct mce had a limitation to 256 CPUs. But x86 Linux supports
more than that now with x2apic. Add a new field extcpu to report the
extended number.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-06-03 14:40:38 -07:00
Andi Kleen
f6fb0ac086 x86, mce: store record length into memory struct mce anchor
This makes it easier for tools who want to extract the mcelog out of
crash images or memory dumps to adapt to changing struct mce size.
The length field replaces padding, so it's fully compatible.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-06-03 14:40:38 -07:00
Andi Kleen
ca84f69697 x86, mce: add MCE poll count to /proc/interrupts
Keep a count of the machine check polls (or CMCI events) in
/proc/interrupts.

Andi needs this for debugging, but it's also useful in general
to see what's going in by the kernel.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-06-03 14:40:38 -07:00
Andi Kleen
01ca79f141 x86, mce: add machine check exception count in /proc/interrupts
Useful for debugging, but it's also good general policy
to have a counter for all special interrupts there. This makes it easier
to diagnose where a CPU is spending its time.

[ Impact: feature, debugging tool ]

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-06-03 14:40:38 -07:00
H. Peter Anvin
48b1fddbb1 Merge branch 'irq/numa' into x86/mce3
Merge reason: arch/x86/kernel/irqinit_{32,64}.c unified in irq/numa
and modified in x86/mce3; this merge resolves the conflict.

Conflicts:
	arch/x86/kernel/irqinit.c

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-06-01 15:25:31 -07:00
Ingo Molnar
ee4c24a5c9 Merge branch 'x86/cpufeature' into irq/numa
Merge reason: irq/numa didnt build because this commit:

  2759c32: x86: don't call read_apic_id if !cpu_has_apic

Had a dependency on x86/cpufeature changes. Pull in that
(small) branch to fix the dependency.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-01 22:30:01 +02:00
Ingo Molnar
3d58f48ba0 Merge branch 'linus' into irq/numa
Conflicts:
	arch/mips/sibyte/bcm1480/irq.c
	arch/mips/sibyte/sb1250/irq.c

Merge reason: we gathered a few conflicts plus update to latest upstream fixes.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-01 21:06:21 +02:00
Joe Perches
61c8c67e3a acpi-cpufreq: fix printk typo and indentation
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-05-29 21:26:26 -04:00
Mel Gorman
32b154c0b0 x86: ignore VM_LOCKED when determining if hugetlb-backed page tables can be shared or not
Addresses http://bugzilla.kernel.org/show_bug.cgi?id=13302

On x86 and x86-64, it is possible that page tables are shared beween
shared mappings backed by hugetlbfs.  As part of this,
page_table_shareable() checks a pair of vma->vm_flags and they must match
if they are to be shared.  All VMA flags are taken into account, including
VM_LOCKED.

The problem is that VM_LOCKED is cleared on fork().  When a process with a
shared memory segment forks() to exec() a helper, there will be shared
VMAs with different flags.  The impact is that the shared segment is
sometimes considered shareable and other times not, depending on what
process is checking.

What happens is that the segment page tables are being shared but the
count is inaccurate depending on the ordering of events.  As the page
tables are freed with put_page(), bad pmd's are found when some of the
children exit.  The hugepage counters also get corrupted and the Total and
Free count will no longer match even when all the hugepage-backed regions
are freed.  This requires a reboot of the machine to "fix".

This patch addresses the problem by comparing all flags except VM_LOCKED
when deciding if pagetables should be shared or not for hugetlbfs-backed
mapping.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: <stable@kernel.org>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: <starlight@binnacle.cx>
Cc: Eric B Munson <ebmunson@us.ibm.com>
Cc: Adam Litke <agl@us.ibm.com>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-29 08:40:03 -07:00
H. Peter Anvin
38736072d4 x86, mce: drop "extern" from function prototypes in asm/mce.h
Function prototypes don't need to be prefixed by "extern".

[ Impact: cleanup ]

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 10:05:33 -07:00
Hidetoshi Seto
cd13adcc82 x86: trivial clean up for arch/x86/Kconfig
Use tab.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 10:05:21 -07:00
Andi Kleen
eb2a6ab729 x86: trivial clean up for irq_vectors.h
Fix a wrong comment.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:16 -07:00
Hidetoshi Seto
98a9c8c3ba x86, mce: trivial clean up for mce-inject.c
Fix for:

WARNING: Use #include <linux/uaccess.h> instead of <asm/uaccess.h>
+#include <asm/uaccess.h>

WARNING: usage of NR_CPUS is often wrong - consider using cpu_possible(), num_possible_cpus(), for_each_possible_cpu(), etc
+       if (m.cpu >= NR_CPUS || !cpu_online(m.cpu))

ERROR: trailing whitespace
+/* $

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:16 -07:00
Hidetoshi Seto
61a021a070 x86, mce: trivial clean up for mce_intel_64.c
Fix for:

WARNING: space prohibited between function name and open parenthesis '('
+       for_each_online_cpu (cpu) {

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:16 -07:00
Hidetoshi Seto
34fa1967aa x86, mce: trivial clean up for mce_amd_64.c
Fix for followings:

WARNING: Use #include <linux/percpu.h> instead of <asm/percpu.h>
+#include <asm/percpu.h>

ERROR: Macros with multiple statements should be enclosed in a do - while
loop
+#define THRESHOLD_ATTR(_name, _mode, _show, _store)                    \
+{                                                                      \
+       .attr   = {.name = __stringify(_name), .mode = _mode },         \
+       .show   = _show,                                                \
+       .store  = _store,                                               \
+};

WARNING: usage of NR_CPUS is often wrong - consider using cpu_possible(),
num_possible_cpus(), for_each_possible_cpu(), etc
+       if (cpu >= NR_CPUS)

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:16 -07:00
Hidetoshi Seto
14a02530e2 x86, mce: trivial clean up for mce.c
This fixs following checkpatch warnings:

WARNING: Use #include <linux/uaccess.h> instead of <asm/uaccess.h>
+#include <asm/uaccess.h>

WARNING: Use #include <linux/smp.h> instead of <asm/smp.h>
+#include <asm/smp.h>

WARNING: line over 80 characters
+                               set_bit(MCE_OVERFLOW, (unsigned long *)&mcelog.flags);

WARNING: braces {} are not necessary for any arm of this statement
+       if (mce_notify_user()) {
[...]
+       } else {
[...]

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:16 -07:00
Hidetoshi Seto
cc3aec52ab x86, mce: trivial clean up for therm_throt.c
This patch removes following checkpatch warning:

WARNING: Use #include <linux/cpu.h> instead of <asm/cpu.h>
+#include <asm/cpu.h>

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:15 -07:00
Hidetoshi Seto
9319cec8c1 x86, mce: use strict_strtoull
Use strict_strtoull instead of simple_strtoull.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:15 -07:00
Andi Kleen
b170204ddb x86, mce: drop BKL in mce_open
BKL is not needed for anything in mce_open because it has
an own spinlock. Remove it.

[ Impact: cleanup ]

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:15 -07:00
Andi Kleen
32561696c2 x86, mce: rename and align out2 label
There's only a single out path in do_machine_check now, so rename the
label from out2 to out.  Also align it at the first column.

[ Impact: minor cleanup, no functional changes ]

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:15 -07:00
Thomas Gleixner
8be9110569 x86, mce: remove mce_init unused argument
Remove unused mce_init argument.

[ Impact: cleanup ]

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:15 -07:00
Andi Kleen
fc016a49c2 x86, mce: remove unused mce_events variable
Remove unused mce_events static variable.

[ Impact: cleanup ]

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:15 -07:00
Andi Kleen
b56f642d2b x86, mce: use extended sysattrs for the check_interval attribute.
Instead of using own callbacks use the generic ones provided by
the sysdev later.

This finally allows to get rid of the ugly ACCESSOR macros. Should
also save some text size.

[ Impact: cleanup ]

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:15 -07:00
Andi Kleen
88921be302 x86, mce: synchronize core after machine check handling
The example code in the IA32 SDM recommends to synchronize the CPU
after machine check handling. So do that here.

[ Impact: Spec compliance ]

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:14 -07:00
H. Peter Anvin
5706001aac x86, mce: fix comment style in mce-inject.c
Fix style of winged comment in mce-inject.c.

[ Impact: comment only ]

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:14 -07:00
H. Peter Anvin
a1ff41bfc1 x86, mce: add comment about mce_chrdev_ops being writable
Add a comment explaining that mce_chrdev_ops is intentionally
writable.

[ Impact: comment only ]

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:14 -07:00
Andi Kleen
ea149b36c7 x86, mce: add basic error injection infrastructure
Allow user programs to write mce records into /dev/mcelog. When they do
that a fake machine check is triggered to test the machine check code.

This uses the MCE MSR wrappers added earlier.

The implementation is straight forward. There is a struct mce record
per CPU and the MCE MSR accesses get data from there if there is valid
data injected there. This allows to test the machine check code
relatively realistically because only the lowest layer of hardware
access is intercepted.

The test suite and injector are available at
git://git.kernel.org/pub/scm/utils/cpu/mce/mce-test.git
git://git.kernel.org/pub/scm/utils/cpu/mce/mce-inject.git

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:14 -07:00
Andi Kleen
5f8c1a54ca x86, mce: add MSR read wrappers for easier error injection
This will be used by future patches to allow machine check error injection.
Right now it's a nop, except for adding some wrappers around the MSR reads.

This is early in the sequence to avoid too many conflicts.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:14 -07:00
Andi Kleen
de5619dfef x86, mce: enable MCE_AMD for 32bit NEW_MCE
That's very easy using the infrastructure enabled earlier for MCE_INTEL

Untested.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:13 -07:00
Andi Kleen
7856f6cce4 x86, mce: enable MCE_INTEL for 32bit new MCE
Enable the 64bit MCE_INTEL code (CMCI, thermal interrupts) for 32bit NEW_MCE.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:13 -07:00
Andi Kleen
4efc0670ba x86, mce: use 64bit machine check code on 32bit
The 64bit machine check code is in many ways much better than
the 32bit machine check code: it is more specification compliant,
is cleaner, only has a single code base versus one per CPU,
has better infrastructure for recovery, has a cleaner way to communicate
with user space etc. etc.

Use the 64bit code for 32bit too.

This is the second attempt to do this. There was one a couple of years
ago to unify this code for 32bit and 64bit.  Back then this ran into some
trouble with K7s and was reverted.

I believe this time the K7 problems (and some others) are addressed.
I went over the old handlers and was very careful to retain
all quirks.

But of course this needs a lot of testing on old systems. On newer
64bit capable systems I don't expect much problems because they have been
already tested with the 64bit kernel.

I made this a CONFIG for now that still allows to select the old
machine check code. This is mostly to make testing easier,
if someone runs into a problem we can ask them to try
with the CONFIG switched.

The new code is default y for more coverage.

Once there is confidence the 64bit code works well on older hardware
too the CONFIG_X86_OLD_MCE and the associated code can be easily
removed.

This causes a behaviour change for 32bit installations. They now
have to install the mcelog package to be able to log
corrected machine checks.

The 64bit machine check code only handles CPUs which support the
standard Intel machine check architecture described in the IA32 SDM.
The 32bit code has special support for some older CPUs which
have non standard machine check architectures, in particular
WinChip C3 and Intel P5.  I made those a separate CONFIG option
and kept them for now. The WinChip variant could be probably
removed without too much pain, it doesn't really do anything
interesting. P5 is also disabled by default (like it
was before) because many motherboards have it miswired, but
according to Alan Cox a few embedded setups use that one.

Forward ported/heavily changed version of old patch, original patch
included review/fixes from Thomas Gleixner, Bert Wesarg.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:13 -07:00
Andi Kleen
d896a940ef x86, mce: remove oops_begin() use in 64bit machine check
First 32bit doesn't have oops_begin, so it's a barrier of using
this code on 32bit.

On closer examination it turns out oops_begin is not
a good idea in a machine check panic anyways. All oops_begin
does it so check for recursive/parallel oopses and implement the
"wait on oops" heuristic. But there's actually no good reason
to lock machine checks against oopses or prevent them
from recursion. Also "wait on oops" does not really make
sense for a machine check too.

Replace it with a manual bust_spinlocks/console_verbose.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:13 -07:00
Andi Kleen
8e97aef5f4 x86, mce: remove machine check handler idle notify on 64bit
i386 has no idle notifiers, but the 64bit machine check
code uses them to wake up mcelog from a fatal machine check
exception.

For corrected machine checks found by the poller or
threshold interrupts going through an idle notifier is not needed
because the wake_up can is just done directly and doesn't
need the idle notifier. It is only needed for logging
exceptions.

To be honest I never liked the idle notifier even though I signed
off on it. On closer investigation the code actually turned out
to be nearly. Right now machine check exceptions on x86 are always
unrecoverable (lead to panic due to PCC), which means we never execute
the idle notifier path.

The only exception is the somewhat weird tolerant==3 case, which
ignores PCC. I'll fix this in a future patch in a much cleaner way.

So remove the "mcelog wakeup through idle notifier" code
from 64bit.

This allows to compile the 64bit machine check handler on 32bit
which doesn't have idle notifiers.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:12 -07:00
Andi Kleen
d7c3c9a609 x86, mce: move mce_disabled option into common 32bit/64bit code
It's the same function, so let's share it.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:12 -07:00
Andi Kleen
04b2b1a4df x86, mce: rename 64bit mce_dont_init to mce_disabled
Give it the same name as on 32bit. This makes further merging easier.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:12 -07:00
Andi Kleen
5d7279268b x86, mce: use a call vector to call the 64bit mce handler
Allows to call different machine check handlers from the low
level machine check entry vector.

This is needed for later when it will be used for 32bit too.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:12 -07:00
Andi Kleen
2e6f694fde x86, mce: port K7 bank 0 quirk to 64bit mce code
Various K7 have broken bank 0s. Don't enable it by default

Port from the 32bit code.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:12 -07:00
Andi Kleen
06b7a7a5ec x86, mce: implement the PPro bank 0 quirk in the 64bit machine check code
Quoting the comment:

* SDM documents that on family 6 bank 0 should not be written
* because it aliases to another special BIOS controlled
* register.
* But it's not aliased anymore on model 0x1a+
* Don't ignore bank 0 completely because there could be a valid
* event later, merely don't write CTL0.

This is mostly a port on the 32bit code, except that 32bit
always didn't write it and didn't have the 0x1a heuristic. I checked
with the CPU designers that the quirk is not required starting with
this model.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:12 -07:00
Andi Kleen
3cde5c8c83 x86, mce: initial steps to make 64bit mce code 32bit clean
Replace unsigned long with u64s if they need to contain 64bit values.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:12 -07:00
Thomas Gleixner
01c6680a54 x86, mce: Cleanup MCG definitions
Decode more magic constants and turn them into symbols.

[ Sort definitions bitwise, introduce MCG_EXT_CNT - HS ]

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-28 09:24:12 -07:00