History log of /arch/x86/kernel/cpu/mcheck/mce.c
Revision Date Author Comments
89cbc76768c2fa4ed95545bf961f3a14ddfeed21 17-Aug-2014 Christoph Lameter <cl@linux.com> x86: Replace __get_cpu_var uses

__get_cpu_var() is used for multiple purposes in the kernel source. One of
them is address calculation via the form &__get_cpu_var(x). This calculates
the address for the instance of the percpu variable of the current processor
based on an offset.

Other use cases are for storing and retrieving data from the current
processors percpu area. __get_cpu_var() can be used as an lvalue when
writing data or on the right side of an assignment.

__get_cpu_var() is defined as :

#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))

__get_cpu_var() always only does an address determination. However, store
and retrieve operations could use a segment prefix (or global register on
other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a
percpu area and use optimized assembly code to read and write per cpu
variables.

This patch converts __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations that
use the offset. Thereby address calculations are avoided and less registers
are used when code is generated.

Transformations done to __get_cpu_var()

1. Determine the address of the percpu instance of the current processor.

DEFINE_PER_CPU(int, y);
int *x = &__get_cpu_var(y);

Converts to

int *x = this_cpu_ptr(&y);

2. Same as #1 but this time an array structure is involved.

DEFINE_PER_CPU(int, y[20]);
int *x = __get_cpu_var(y);

Converts to

int *x = this_cpu_ptr(y);

3. Retrieve the content of the current processors instance of a per cpu
variable.

DEFINE_PER_CPU(int, y);
int x = __get_cpu_var(y)

Converts to

int x = __this_cpu_read(y);

4. Retrieve the content of a percpu struct

DEFINE_PER_CPU(struct mystruct, y);
struct mystruct x = __get_cpu_var(y);

Converts to

memcpy(&x, this_cpu_ptr(&y), sizeof(x));

5. Assignment to a per cpu variable

DEFINE_PER_CPU(int, y)
__get_cpu_var(y) = x;

Converts to

__this_cpu_write(y, x);

6. Increment/Decrement etc of a per cpu variable

DEFINE_PER_CPU(int, y);
__get_cpu_var(y)++

Converts to

__this_cpu_inc(y)

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
164109e3cdba52b9f2ece063bc3aa2a90f77c273 08-Aug-2014 Daniel Walter <dwalter@google.com> arch/x86: replace strict_strto calls

Replace obsolete strict_strto calls with appropriate kstrto calls

Signed-off-by: Daniel Walter <dwalter@google.com>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
51cbe7e7c400def749950ab6b2c120624dbe21a7 20-Jun-2014 Borislav Petkov <bp@suse.de> x86, MCE: Robustify mcheck_init_device

BorisO reports that misc_register() fails often on xen. The current code
unregisters the CPU hotplug notifier in that case. If then a CPU is
offlined and onlined back again, we end up with a second timer running
on that CPU, leading to soft lockups and system hangs.

So let's leave the hotcpu notifier always registered - even if
mce_device_create failed for some cores and never unreg it so that we
can deal with the timer handling accordingly.

Reported-and-Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: http://lkml.kernel.org/r/1403274493-1371-1-git-send-email-boris.ostrovsky@oracle.com
Signed-off-by: Borislav Petkov <bp@suse.de>
27c934158c5be0bebfb2970da521b9d9efc0058b 20-Jun-2014 Borislav Petkov <bp@suse.de> x86, MCE: Robustify mcheck_init_device

BorisO reports that misc_register() fails often on xen. The current code
unregisters the CPU hotplug notifier in that case. If then a CPU is
offlined and onlined back again, we end up with a second timer running
on that CPU, leading to soft lockups and system hangs.

So let's leave the hotcpu notifier always registered - even if
mce_device_create failed for some cores and never unreg it so that we
can deal with the timer handling accordingly.

Reported-and-Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: http://lkml.kernel.org/r/1403274493-1371-1-git-send-email-boris.ostrovsky@oracle.com
Signed-off-by: Borislav Petkov <bp@suse.de>
38356c1fbd8cd0f44a32ede2c97f0eb639d06613 22-May-2014 Borislav Petkov <bp@suse.de> x86, MCE: Kill CPU_POST_DEAD

In conjunction with cleaning up CPU hotplug, we want to get rid of
CPU_POST_DEAD. Kill this instance here and rediscover CMCI banks at the
end of CPU_DEAD.

Link: http://lkml.kernel.org/r/http://lkml.kernel.org/r/1400750624-19238-1-git-send-email-bp@alien8.de
Signed-off-by: Borislav Petkov <bp@suse.de>
65eb71823b01051ca6e256e9cc8259141a849052 05-Jun-2014 Chen Yucong <slaoub@gmail.com> hwpoison: remove unused global variable in do_machine_check()

Remove an unused global variable mce_entry and relative operations in
do_machine_check().

Signed-off-by: Chen Yucong <slaoub@gmail.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
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>
716079f66eacd31d040db9cd0627ca0d625d6126 23-May-2014 Borislav Petkov <bp@suse.de> mce: Panic when a core has reached a timeout

There is very little and maybe practically nothing we can do to recover
from a system where at least one core has reached a timeout during the
whole monarch cores gathering. So panic when that happens.

Link: http://lkml.kernel.org/r/20140523091041.GA21332@pd.tnic
Signed-off-by: Borislav Petkov <bp@suse.de>
9c15a24b038f4d8da93a2bc2554731f8953a7c17 28-May-2014 Mathieu Souchaud <mattieu.souchaud@free.fr> x86/mce: Improve mcheck_init_device() error handling

Check return code of every function called by mcheck_init_device().

Signed-off-by: Mathieu Souchaud <mattieu.souchaud@free.fr>
Link: http://lkml.kernel.org/r/1399151031-19905-1-git-send-email-mattieu.souchaud@free.fr
Signed-off-by: Borislav Petkov <bp@suse.de>
ea431643d6c38728195e2c456801c3ef66bb9991 17-Apr-2014 Ingo Molnar <mingo@kernel.org> x86/mce: Fix CMCI preemption bugs

The following commit:

27f6c573e0f7 ("x86, CMCI: Add proper detection of end of CMCI storms")

Added two preemption bugs:

- machine_check_poll() does a get_cpu_var() without a matching
put_cpu_var(), which causes preemption imbalance and crashes upon
bootup.

- it does percpu ops without disabling preemption. Preemption is not
disabled due to the mistaken use of a raw spinlock.

To fix these bugs fix the imbalance and change
cmci_discover_lock to a regular spinlock.

Reported-by: Owen Kibel <qmewlo@gmail.com>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Chen, Gong <gong.chen@linux.intel.com>
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alexander Todorov <atodorov@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Link: http://lkml.kernel.org/n/tip-jtjptvgigpfkpvtQxpEk1at2@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
--
arch/x86/kernel/cpu/mcheck/mce.c | 4 +---
arch/x86/kernel/cpu/mcheck/mce_intel.c | 18 +++++++++---------
2 files changed, 10 insertions(+), 12 deletions(-)
27f6c573e0f77f7d1cc907c1494c99a61e48b7d8 28-Mar-2014 Chen, Gong <gong.chen@linux.intel.com> x86, CMCI: Add proper detection of end of CMCI storms

When CMCI storm persists for a long time(at least beyond predefined
threshold. It's 30 seconds for now), we can watch CMCI storm is
detected immediately after it subsides.

...
Dec 10 22:04:29 kernel: CMCI storm detected: switching to poll mode
Dec 10 22:04:59 kernel: CMCI storm subsided: switching to interrupt mode
Dec 10 22:04:59 kernel: CMCI storm detected: switching to poll mode
Dec 10 22:05:29 kernel: CMCI storm subsided: switching to interrupt mode
...

The problem is that our logic that determines that the storm has
ended is incorrect. We announce the end, re-enable interrupts and
realize that the storm is still going on, so we switch back to
polling mode. Rinse, repeat.

When a storm happens we disable signaling of errors via CMCI and begin
polling machine check banks instead. If we find any logged errors,
then we need to set a per-cpu flag so that our per-cpu tests that
check whether the storm is ongoing will see that errors are still
being logged independently of whether mce_notify_irq() says that the
error has been fully processed.

cmci_clear() is not the right tool to disable a bank. It disables the
interrupt for the bank as desired, but it also clears the bit for
this bank in "mce_banks_owned" so we will skip the bank when polling
(so we fail to see that the storm continues because we stop looking).
New cmci_storm_disable_banks() just disables the interrupt while
allowing polling to continue.

Reported-by: William Dauchy <wdauchy@gmail.com>
Signed-off-by: Chen, Gong <gong.chen@linux.intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
82a8f131aadf55ac7fbc8c6f65f34d83101160de 10-Mar-2014 Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> x86, mce: Fix CPU hotplug callback registration

Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:

get_online_cpus();

for_each_online_cpu(cpu)
init_cpu(cpu);

register_cpu_notifier(&foobar_cpu_notifier);

put_online_cpus();

This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).

Instead, the correct and race-free way of performing the callback
registration is:

cpu_notifier_register_begin();

for_each_online_cpu(cpu)
init_cpu(cpu);

/* Note the use of the double underscored version of the API */
__register_cpu_notifier(&foobar_cpu_notifier);

cpu_notifier_register_done();

Fix the mce code in x86 by using this latter form of callback registration.

Cc: Tony Luck <tony.luck@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
4f75d8412792777a314ac5c1393a9ed43d695fd1 23-Dec-2013 Borislav Petkov <bp@suse.de> x86, mce: Fix mce_start_timer semantics

So mce_start_timer() has a 'cpu' argument which is supposed to mean to
start a timer on that cpu. However, the code currently starts a timer on
the *current* cpu the function runs on and causes the sanity-check in
mce_timer_fn to fire:

WARNING: CPU: 0 PID: 0 at arch/x86/kernel/cpu/mcheck/mce.c:1286 mce_timer_fn

because it is running on the wrong cpu.

This was triggered by Prarit Bhargava <prarit@redhat.com> by offlining
all the cpus in succession.

Then, we were fiddling with the CMCI storm settings when starting the
timer whereas there's no need for that - if there's storm happening
on this newly restarted cpu, we're going to be in normal CMCI mode
initially and then when the CMCI interrupt starts firing, we're going to
go to the polling mode with the timer real soon.

Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Prarit Bhargava <prarit@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>
Reviewed-by: Chen, Gong <gong.chen@linux.intel.com>
Link: http://lkml.kernel.org/r/1387722156-5511-1-git-send-email-prarit@redhat.com
853d9b18f1e861d37e9b271742329f8c1176eabe 29-Nov-2013 Levente Kurusa <levex@linux.com> x86, mce: Call put_device on device_register failure

This patch adds a call to put_device() when the device_register() call
has failed. This is required so that the last reference to the device is
given up.

Signed-off-by: Levente Kurusa <levex@linux.com>
Link: http://lkml.kernel.org/r/5298F900.9000208@linux.com
Signed-off-by: Borislav Petkov <bp@suse.de>
148f9bb87745ed45f7a11b2cbd3bc0f017d5d257 19-Jun-2013 Paul Gortmaker <paul.gortmaker@windriver.com> x86: delete __cpuinit usage from all x86 files

The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications. For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out. Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
are flagged as __cpuinit -- so if we remove the __cpuinit from
arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
content into no-ops as early as possible, since that will get rid
of these warnings. In any case, they are temporary and harmless.

This removes all the arch/x86 uses of the __cpuinit macros from
all C files. x86 only had the one __CPUINIT used in assembly files,
and it wasn't paired off with a .previous or a __FINIT, so we can
delete it directly w/o any corresponding additional change there.

[1] https://lkml.org/lkml/2013/5/20/589

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
c3d1fb567a634dcdff4c6f6095b2053260988336 01-Jul-2013 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> mce: acpi/apei: Honour Firmware First for MCA banks listed in APEI HEST CMC

The Corrected Machine Check structure (CMC) in HEST has a flag which can be
set by the firmware to indicate to the OS that it prefers to process the
corrected error events first. In this scenario, the OS is expected to not
monitor for corrected errors (through CMCI/polling). Instead, the firmware
notifies the OS on corrected error events through GHES.

Linux already has support for GHES. This patch adds support for parsing CMC
structure and to disable CMCI/polling if the firmware first flag is set.

Further, the list of machine check bank structures at the end of CMC is used
to determine which MCA banks function in FF mode, so that we continue to
monitor error events on the other banks.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
0644414e62561f0ba1bea7c5ba6a94cc50dac3e3 25-Jun-2013 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> mce: acpi/apei: Add comments to clarify usage of the various bitfields in the MCA subsystem

There is some confusion about the 'mce_poll_banks' and 'mce_banks_owned'
per-cpu bitmaps. Provide comments so that we all know exactly what these
are used for, and why.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
7a0c819d28f5c91955854e048766d6afef7c8a3d 20-Mar-2013 Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> x86/mce: Rework cmci_rediscover() to play well with CPU hotplug

Dave Jones reports that offlining a CPU leads to this trace:

numa_remove_cpu cpu 1 node 0: mask now 0,2-3
smpboot: CPU 1 is now offline
BUG: using smp_processor_id() in preemptible [00000000] code:
cpu-offline.sh/10591
caller is cmci_rediscover+0x6a/0xe0
Pid: 10591, comm: cpu-offline.sh Not tainted 3.9.0-rc3+ #2
Call Trace:
[<ffffffff81333bbd>] debug_smp_processor_id+0xdd/0x100
[<ffffffff8101edba>] cmci_rediscover+0x6a/0xe0
[<ffffffff815f5b9f>] mce_cpu_callback+0x19d/0x1ae
[<ffffffff8160ea66>] notifier_call_chain+0x66/0x150
[<ffffffff8107ad7e>] __raw_notifier_call_chain+0xe/0x10
[<ffffffff8104c2e3>] cpu_notify+0x23/0x50
[<ffffffff8104c31e>] cpu_notify_nofail+0xe/0x20
[<ffffffff815ef082>] _cpu_down+0x302/0x350
[<ffffffff815ef106>] cpu_down+0x36/0x50
[<ffffffff815f1c9d>] store_online+0x8d/0xd0
[<ffffffff813edc48>] dev_attr_store+0x18/0x30
[<ffffffff81226eeb>] sysfs_write_file+0xdb/0x150
[<ffffffff811adfb2>] vfs_write+0xa2/0x170
[<ffffffff811ae16c>] sys_write+0x4c/0xa0
[<ffffffff81613019>] system_call_fastpath+0x16/0x1b

However, a look at cmci_rediscover shows that it can be simplified quite
a bit, apart from solving the above issue. It invokes functions that
take spin locks with interrupts disabled, and hence it can run in atomic
context. Also, it is run in the CPU_POST_DEAD phase, so the dying CPU
is already dead and out of the cpu_online_mask. So take these points into
account and simplify the code, and thereby also fix the above issue.

Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
373d4d099761cb1f637bed488ab3871945882273 21-Jan-2013 Rusty Russell <rusty@rustcorp.com.au> taint: add explicit flag to show whether lock dep is still OK.

Fix up all callers as they were before, with make one change: an
unsigned module taints the kernel, but doesn't turn off lockdep.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
4d899be584d4b4c5d6b49d655176b25cebf6ff1a 22-Dec-2012 Tejun Heo <tj@kernel.org> x86/mce: don't use [delayed_]work_pending()

There's no need to test whether a (delayed) work item in pending
before queueing, flushing or cancelling it. Most uses are unnecessary
and quite a few of them are buggy.

Remove unnecessary pending tests from x86/mce. Only compile tested.

v2: Local var work removed from mce_schedule_work() as suggested by
Borislav.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-edac@vger.kernel.org
1462594bf2866c1dc80066ed6f49f4331c551901 17-Oct-2012 Borislav Petkov <bp@alien8.de> x86, MCA: Finish mca_config conversion

mce_ser, mce_bios_cmci_threshold and mce_disabled are the last three
bools which need conversion. Move them to the mca_config struct and
adjust usage sites accordingly.

Signed-off-by: Borislav Petkov <bp@alien8.de>
Acked-by: Tony Luck <tony.luck@intel.com>
7af19e4afdafa4adb5fffc569d5bb1c5e568ba98 15-Oct-2012 Borislav Petkov <bp@alien8.de> x86, MCA: Convert the next three variables batch

Move them into the mca_config struct and adjust code touching them
accordingly.

Signed-off-by: Borislav Petkov <bp@alien8.de>
Acked-by: Tony Luck <tony.luck@intel.com>
84c2559dee2d69606f1fd4ce6563e79e7611a7b7 15-Oct-2012 Borislav Petkov <bp@alien8.de> x86, MCA: Convert rip_msr, mce_bootlog, monarch_timeout

Move above configuration variables into struct mca_config and adjust
usage places accordingly.

Signed-off-by: Borislav Petkov <bp@alien8.de>
Acked-by: Tony Luck <tony.luck@intel.com>
d203f0b82481abc048e134ee4d0ea3efbee77bb1 15-Oct-2012 Borislav Petkov <bp@alien8.de> x86, MCA: Convert dont_log_ce, banks and tolerant

Move those MCA configuration variables into struct mca_config and adjust
the places they're used accordingly.

Signed-off-by: Borislav Petkov <bp@alien8.de>
Acked-by: Tony Luck <tony.luck@intel.com>
5bc66170dc486556a1e36fd384463536573f4b82 18-Oct-2012 Borislav Petkov <borislav.petkov@amd.com> x86, MCE: Remove bios_cmci_threshold sysfs attribute

450cc201038f3 ("x86/mce: Provide boot argument to honour bios-set CMCI
threshold") added the bios_cmci_threshold sysfs attribute which was
supposed to communicate to userspace tools that BIOS CMCI threshold has
been honoured.

However, this info is not of any importance to userspace - it should
rather get the actual error count it has been thresholded already from
MCi_STATUS[38:52].

So drop this before it becomes a used interface (good thing we caught
this early in 3.7-rc1, right after the merge window closed).

Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/20121017105940.GA14590@x1.osrc.amd.com
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
450cc201038f31bd496e1b3a44a49790b8827a06 27-Sep-2012 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> x86/mce: Provide boot argument to honour bios-set CMCI threshold

The ACPI spec doesn't provide for a way for the bios to pass down
recommended thresholds to the OS on a _per-bank_ basis. This patch adds
a new boot option, which if passed, tells Linux to use CMCI thresholds
set by the bios.

As fail-safe, we initialize threshold to 1 if some banks have not been
initialized by the bios and warn the user.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
55babd8f41f122f5f4c7cebf520c766c983282c6 09-Aug-2012 Chen Gong <gong.chen@linux.intel.com> x86/mce: Add CMCI poll mode

On Intel systems corrected machine check interrupts (CMCI) may be sent to
multiple logical processors; possibly to all processors on the affected
socket (SDM Volume 3B "15.5.1 CMCI Local APIC Interface"). This means
that a persistent error (such as a stuck bit in ECC memory) may cause
a storm of interrupts that greatly hinders or prevents forward progress
(probably on many processors).

To solve this we keep track of the rate at which each processor sees
CMCI. If we exceed a threshold, we disable CMCI delivery and switch to
polling the machine check banks. If the storm subsides (none of the
affected processors see any more errors for a complete poll interval) we
re-enable CMCI.

[Tony: Added console messages when storm begins/ends and increased storm
threshold from 5 to 15 so we have a few more logged entries before we
disable interrupts and start dropping reports]

Signed-off-by: Chen Gong <gong.chen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Chen Gong <gong.chen@linux.intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
1a65f970d10ace7a1e399f9061a65679c0ae57d0 19-Jul-2012 Thomas Gleixner <tglx@linutronix.de> x86: mce: Remove the frozen cases in the hotplug code

No point in having double cases if we can simply mask the FROZEN bit
out.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Chen Gong <gong.chen@linux.intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
26c3c283c5b08dd250279c06ba3ab5b094bbacc3 19-Jul-2012 Thomas Gleixner <tglx@linutronix.de> x86: mce: Split timer init

Split timer init function into the init and the start part, so the
start part can replace the open coded version in CPU_DOWN_FAILED.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Chen Gong <gong.chen@linux.intel.com>
Acked-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
61b0fccd7f114573f973dfe25d864608822dc09e 19-Jul-2012 Tony Luck <tony.luck@intel.com> x86/mce: Add quirk for instruction recovery on Sandy Bridge processors

Sandy Bridge processors follow the SDM (Vol 3B, Table 15-20) and
set both the RIPV and EIPV bits in the MCG_STATUS register to
zero for machine checks during instruction fetch. This is more
than a little counter-intuitive and means that Linux cannot
recover from these errors. Rather than insert special case code
at several places in mce.c and mce-severity.c, we pretend the
EIPV bit was set for just this case early in processing the
machine check.

Acked-by: Borislav Petkov <bp@amd64.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Cc: Chen Gong <gong.chen@linux.intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Link: http://lkml.kernel.org/r/180a06f3f357cf9f78259ae443a082b14a29535b.1343078495.git.tony.luck@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
cef12ee52b054282461a6d5fe7742755fa6e3bd3 07-Jun-2012 Liu, Jinsong <jinsong.liu@intel.com> xen/mce: Add mcelog support for Xen platform

When MCA error occurs, it would be handled by Xen hypervisor first,
and then the error information would be sent to initial domain for logging.

This patch gets error information from Xen hypervisor and convert
Xen format error into Linux format mcelog. This logic is basically
self-contained, not touching other kernel components.

By using tools like mcelog tool users could read specific error information,
like what they did under native Linux.

To test follow directions outlined in Documentation/acpi/apei/einj.txt

Acked-and-tested-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Ke, Liping <liping.ke@intel.com>
Signed-off-by: Jiang, Yunhong <yunhong.jiang@intel.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
6751ed65dc6642af64f7b8a440a75563c8aab7ae 11-Jul-2012 Tony Luck <tony.luck@intel.com> x86/mce: Fix siginfo_t->si_addr value for non-recoverable memory faults

In commit dad1743e5993f1 ("x86/mce: Only restart instruction after machine
check recovery if it is safe") we fixed mce_notify_process() to force a
signal to the current process if it was not restartable (RIPV bit not
set in MCG_STATUS). But doing it here means that the process doesn't
get told the virtual address of the fault via siginfo_t->si_addr. This
would prevent application level recovery from the fault.

Make a new MF_MUST_KILL flag bit for memory_failure() et al. to use so
that we will provide the right information with the signal.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Borislav Petkov <borislav.petkov@amd.com>
Cc: stable@kernel.org # 3.4+
1a87fc1ec7b05b9bc60df9dc52297d4c225d7f1a 06-Jun-2012 Thomas Gleixner <tglx@linutronix.de> x86: mce: Add the dropped timer interval init back

commit 82f7af09 ("x86/mce: Cleanup timer mess) dropped the
initialization of the per cpu timer interval. Duh :(

Restore the previous behaviour.

Reported-by: Chen Gong <gong.chen@linux.intel.com>
Cc: bp@amd64.org
Cc: tony.luck@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
c767a54ba0657e52e6edaa97cbe0b0a8bf1c1655 22-May-2012 Joe Perches <joe@perches.com> x86/debug: Add KERN_<LEVEL> to bare printks, convert printks to pr_<level>

Use a more current logging style:

- Bare printks should have a KERN_<LEVEL> for consistency's sake
- Add pr_fmt where appropriate
- Neaten some macro definitions
- Convert some Ok output to OK
- Use "%s: ", __func__ in pr_fmt for summit
- Convert some printks to pr_<level>

Message output is not identical in all cases.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: levinsasha928@gmail.com
Link: http://lkml.kernel.org/r/1337655007.24226.10.camel@joe2Laptop
[ merged two similar patches, tidied up the changelog ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
958fb3c51295764599d6abce87e1a01ace897a3e 05-Jun-2012 Chen Gong <gong.chen@linux.intel.com> x86/mce: Fix the MCE poll timer logic

In commit 82f7af09 ("x86/mce: Cleanup timer mess), Thomas just
forgot the "/ 2" there while cleaning up.

Signed-off-by: Chen Gong <gong.chen@linux.intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: bp@amd64.org
Cc: tony.luck@intel.com
Link: http://lkml.kernel.org/r/1338863702-9245-1-git-send-email-gong.chen@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
c2238f10e0c34a85a2a555c8a197316d1ca3fb7e 05-Jun-2012 Chen Gong <gong.chen@linux.intel.com> x86/mce: Fix the MCE poll timer logic

In commit 82f7af09 (x86/mce: Cleanup timer mess), Thomas just forgot
the "/ 2" there while cleaning up.

Signed-off-by: Chen Gong <gong.chen@linux.intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
82f7af09e6fb58fb725c850d725d5e8780a9bec2 24-May-2012 Thomas Gleixner <tglx@linutronix.de> x86/mce: Cleanup timer mess

Use unsigned long for dealing with jiffies not int. Rename the
callback to something sensible. Use __this_cpu_read/write for
accessing per cpu data.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
a129a7c84582629741e5fa6f40026efcd7a65bd4 19-Nov-2010 Andi Kleen <andi@firstfloor.org> MCE: Fix vm86 handling for 32bit mce handler

When running on 32bit the mce handler could misinterpret
vm86 mode as ring 0. This can affect whether it does recovery
or not; it was possible to panic when recovery was actually
possible.

Fix this by always forcing vm86 to look like ring 3.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
80f033610fb968e75f5d470233d8d0260d7a72ed 22-May-2012 Borislav Petkov <borislav.petkov@amd.com> x86/mce: Fix 32-bit build

Got bitten again by the BIT() macro:

arch/x86/kernel/cpu/mcheck/mce.c: In function '__mcheck_cpu_apply_quirks':
arch/x86/kernel/cpu/mcheck/mce.c:1453:6: warning: left shift
count >= width of type arch/x86/kernel/cpu/mcheck/mce.c:1454:7: warning: left shift count >= width of type

Fix it already.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Cc: Frank Arnold <frank.arnold@amd.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1337684026-19740-2-git-send-email-bp@amd64.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
dad1743e5993f19b3d7e7bd0fb35dc45b5326626 15-May-2012 Tony Luck <tony.luck@intel.com> x86/mce: Only restart instruction after machine check recovery if it is safe

Section 15.3.1.2 of the software developer manual has this to say about the
RIPV bit in the IA32_MCG_STATUS register:

RIPV (restart IP valid) flag, bit 0 — Indicates (when set) that program
execution can be restarted reliably at the instruction pointed to by the
instruction pointer pushed on the stack when the machine-check exception
is generated. When clear, the program cannot be reliably restarted at
the pushed instruction pointer.

We need to save the state of this bit in do_machine_check() and use it
in mce_notify_process() to force a signal; even if memory_failure() says
it made a complete recovery ... e.g. replaced a clean LRU page.

Acked-by: Borislav Petkov <bp@amd64.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
c6ae41e7d469f00d9c92a2b2887c7235d121c009 11-May-2012 Alex Shi <alex.shi@intel.com> x86: replace percpu_xxx funcs with this_cpu_xxx

Since percpu_xxx() serial functions are duplicated with this_cpu_xxx().
Removing percpu_xxx() definition and replacing them by this_cpu_xxx()
in code. There is no function change in this patch, just preparation for
later percpu_xxx serial function removing.

On x86 machine the this_cpu_xxx() serial functions are same as
__this_cpu_xxx() without no unnecessary premmpt enable/disable.

Thanks for Stephen Rothwell, he found and fixed a i386 build error in
the patch.

Also thanks for Andrew Morton, he kept updating the patchset in Linus'
tree.

Signed-off-by: Alex Shi <alex.shi@intel.com>
Acked-by: Christoph Lameter <cl@gentwo.org>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
575203b4747c371698dd686b1fa6d0a3a0c47ac6 20-Apr-2012 Borislav Petkov <borislav.petkov@amd.com> x86, MCE, AMD: Disable error thresholding bank 4 on some models

Turn off MC4_MISC thresholding banks on models which have them but that
particular processor implementation does not supply applicable error
sources to be counted.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
95022b8cf6ed7f3292b60c8e85fe59a12bfb1c9e 19-Apr-2012 Tony Luck <tony.luck@intel.com> x86/mce: Avoid reading every machine check bank register twice.

Reading machine check bank registers is slow. There is a trend of
increasing the number of banks, and the number of cores. The main section
of do_machine_check() is a serialized section where each cpu in turn
checks every bank. Even on a little two socket SandyBridge-EP system
that multiplies out as:

2 sockets * 8 cores * 2 hyperthreads * 20 banks = 640 MSRs

We already scan the banks in parallel in mce_no_way_out() to see if there
is a fatal error anywhere in the system. If we build a cache of VALID
bits during this scan, we can avoid uselessly re-reading banks that have
no data. Note that this cache is only a hint. If the valid bit is set in a
shared bank, all cpus that share that bank will see it during the parallel
scan, but the first to find it in the sequential scan will (usually) clear
the bank.

Acked-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
b11e3d782b9c065b3b2fb543bfb0d97801822dc0 07-Mar-2012 Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> x86, mce: Fix rcu splat in drain_mce_log_buffer()

While booting, the following message is seen:

[ 21.665087] ===============================
[ 21.669439] [ INFO: suspicious RCU usage. ]
[ 21.673798] 3.2.0-0.0.0.28.36b5ec9-default #2 Not tainted
[ 21.681353] -------------------------------
[ 21.685864] arch/x86/kernel/cpu/mcheck/mce.c:194 suspicious rcu_dereference_index_check() usage!
[ 21.695013]
[ 21.695014] other info that might help us debug this:
[ 21.695016]
[ 21.703488]
[ 21.703489] rcu_scheduler_active = 1, debug_locks = 1
[ 21.710426] 3 locks held by modprobe/2139:
[ 21.714754] #0: (&__lockdep_no_validate__){......}, at: [<ffffffff8133afd3>] __driver_attach+0x53/0xa0
[ 21.725020] #1:
[ 21.725323] ioatdma: Intel(R) QuickData Technology Driver 4.00
[ 21.733206] (&__lockdep_no_validate__){......}, at: [<ffffffff8133afe1>] __driver_attach+0x61/0xa0
[ 21.743015] #2: (i7core_edac_lock){+.+.+.}, at: [<ffffffffa01cfa5f>] i7core_probe+0x1f/0x5c0 [i7core_edac]
[ 21.753708]
[ 21.753709] stack backtrace:
[ 21.758429] Pid: 2139, comm: modprobe Not tainted 3.2.0-0.0.0.28.36b5ec9-default #2
[ 21.768253] Call Trace:
[ 21.770838] [<ffffffff810977cd>] lockdep_rcu_suspicious+0xcd/0x100
[ 21.777366] [<ffffffff8101aa41>] drain_mcelog_buffer+0x191/0x1b0
[ 21.783715] [<ffffffff8101aa78>] mce_register_decode_chain+0x18/0x20
[ 21.790430] [<ffffffffa01cf8db>] i7core_register_mci+0x2fb/0x3e4 [i7core_edac]
[ 21.798003] [<ffffffffa01cfb14>] i7core_probe+0xd4/0x5c0 [i7core_edac]
[ 21.804809] [<ffffffff8129566b>] local_pci_probe+0x5b/0xe0
[ 21.810631] [<ffffffff812957c9>] __pci_device_probe+0xd9/0xe0
[ 21.816650] [<ffffffff813362e4>] ? get_device+0x14/0x20
[ 21.822178] [<ffffffff81296916>] pci_device_probe+0x36/0x60
[ 21.828061] [<ffffffff8133ac8a>] really_probe+0x7a/0x2b0
[ 21.833676] [<ffffffff8133af23>] driver_probe_device+0x63/0xc0
[ 21.839868] [<ffffffff8133b01b>] __driver_attach+0x9b/0xa0
[ 21.845718] [<ffffffff8133af80>] ? driver_probe_device+0xc0/0xc0
[ 21.852027] [<ffffffff81339168>] bus_for_each_dev+0x68/0x90
[ 21.857876] [<ffffffff8133aa3c>] driver_attach+0x1c/0x20
[ 21.863462] [<ffffffff8133a64d>] bus_add_driver+0x16d/0x2b0
[ 21.869377] [<ffffffff8133b6dc>] driver_register+0x7c/0x160
[ 21.875220] [<ffffffff81296bda>] __pci_register_driver+0x6a/0xf0
[ 21.881494] [<ffffffffa01fe000>] ? 0xffffffffa01fdfff
[ 21.886846] [<ffffffffa01fe047>] i7core_init+0x47/0x1000 [i7core_edac]
[ 21.893737] [<ffffffff810001ce>] do_one_initcall+0x3e/0x180
[ 21.899670] [<ffffffff810a9b95>] sys_init_module+0xc5/0x220
[ 21.905542] [<ffffffff8149bc39>] system_call_fastpath+0x16/0x1b

Fix this by using ACCESS_ONCE() instead of rcu_dereference_check_mce()
over mcelog.next. Since the access to each entry is controlled by the
->finished field, ACCESS_ONCE() should work just fine. An rcu_dereference
is unnecessary here.

Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Suggested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
fadd85f16a8ec3fee8af599e79a209682dc52348 23-Jan-2012 Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> x86/mce: Fix return value of mce_chrdev_read() when erst is disabled

Current kernel MCE code reads ERST at the first reading of /dev/mcelog
(maybe in starting mcelogd,) even if the system does not support ERST,
which results in a fake "no such device" message (as described in [1].)
This problem is not critical, but can confuse system admins.
This patch fixes it by filtering the return value from lower (ACPI) layer.

[1] http://thread.gmane.org/gmane.linux.kernel/1060250

Reported by: Jon Masters <jonathan@jonmasters.org>
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Huang Ying <ying.huang@intel.com>
Link: https://lkml.org/lkml/2012/1/23/299
Signed-off-by: Tony Luck <tony.luck@intel.com>
d6126ef5f31ca54980cb067af659a360dfcca037 27-Jan-2012 Greg Kroah-Hartman <gregkh@suse.de> x86/mce: Convert static array of pointers to per-cpu variables

When I previously fixed up the mce_device code, I used a static array of
the pointers. It was (rightfully) pointed out to me that I should be
using the per_cpu code instead.

This patch converts the code over to that structure, moving the variable
back into the per_cpu area, like it used to be for 3.2 and earlier.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Link: https://lkml.org/lkml/2012/1/27/165
Signed-off-by: Tony Luck <tony.luck@intel.com>
e032d80774315869aa2285b217fdbbfed86c0b49 16-Jan-2012 Greg Kroah-Hartman <gregkh@suse.de> mce: fix warning messages about static struct mce_device

When suspending, there was a large list of warnings going something like:

Device 'machinecheck1' does not have a release() function, it is broken and must be fixed

This patch turns the static mce_devices into dynamically allocated, and
properly frees them when they are removed from the system. It solves
the warning messages on my laptop here.

Reported-by: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Tested-by: Djalal Harouni <tixxdz@opendz.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Borislav Petkov <bp@amd64.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
a3301b751b19f0efbafddc4034f8e7ce6bf3007b 14-Jan-2012 Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> x86/mce: Fix CPU hotplug and suspend regression related to MCE

Commit 8a25a2fd126c ("cpu: convert 'cpu' and 'machinecheck' sysdev_class
to a regular subsystem") changed how things are dealt with in the MCE
subsystem. Some of the things that got broken due to this are CPU
hotplug and suspend/hibernate.

MCE uses per_cpu allocations of struct device. So, when a CPU goes
offline and comes back online, in order to ensure that we start from a
clean slate with respect to the MCE subsystem, zero out the entire
per_cpu device structure to 0 before using it.

Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
a8c321fbf9aeced45519248e5901af8cbc240510 03-Jan-2012 Tony Luck <tony.luck@intel.com> x86/mce: Handle "action required" errors

All non-urgent actions (reporting low severity errors and handling
"action-optional" errors) are now handled by a work queue. This
means that TIF_MCE_NOTIFY can be used to block execution for a
thread experiencing an "action-required" fault until we get all
cpus out of the machine check handler (and the thread that hit
the fault into mce_notify_process().

We use the new mce_{save,find,clear}_info() API to get information
from do_machine_check() to mce_notify_process(), and then use the
newly improved memory_failure(..., MF_ACTION_REQUIRED) to handle
the error (possibly signalling the process).

Update some comments to make the new code flows clearer.

Signed-off-by: Tony Luck <tony.luck@intel.com>
af104e394e17e328df85c25a9e21448539725b67 15-Dec-2011 Tony Luck <tony.luck@intel.com> x86/mce: Add mechanism to safely save information in MCE handler

Machine checks on Intel cpus interrupt execution on all cpus, regardless
of interrupt masking. We have a need to save some data about the cause
of the machine check (physical address) in the machine check handler that
can be retrieved later to attempt recovery in a more flexible execution
state.

Signed-off-by: Tony Luck <tony.luck@intel.com>
85f92694affa7dba7f1978666a69552b5dfc628e 13-Dec-2011 Tony Luck <tony.luck@intel.com> x86/mce: Create helper function to save addr/misc when needed

The MCI_STATUS_MISCV and MCI_STATUS_ADDRV bits in the bank status
registers define whether the MISC and ADDR registers respectively
contain valid data - provide a helper function to check these bits
and read the registers when needed.

In addition, processors that support software error recovery (as
indicated by the MCG_SER_P bit in the MCG_CAP register) may include
some undefined bits in the ADDR register - mask these out.

Acked-by: Borislav Petkov <bp@amd64.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
cd42f4a3b2b1c4cbd997363dc57821953d73fd87 15-Dec-2011 Tony Luck <tony.luck@intel.com> HWPOISON: Clean up memory_failure() vs. __memory_failure()

There is only one caller of memory_failure(), all other users call
__memory_failure() and pass in the flags argument explicitly. The
lone user of memory_failure() will soon need to pass flags too.

Add flags argument to the callsite in mce.c. Delete the old memory_failure()
function, and then rename __memory_failure() without the leading "__".

Provide clearer message when action optional memory errors are ignored.

Acked-by: Borislav Petkov <bp@amd64.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
8a25a2fd126c621f44f3aeaef80d51f00fc11639 21-Dec-2011 Kay Sievers <kay.sievers@vrfy.org> cpu: convert 'cpu' and 'machinecheck' sysdev_class to a regular subsystem

This moves the 'cpu sysdev_class' over to a regular 'cpu' subsystem
and converts the devices to regular devices. The sysdev drivers are
implemented as subsystem interfaces now.

After all sysdev classes are ported to regular driver core entities, the
sysdev implementation will be entirely removed from the kernel.

Userspace relies on events and generic sysfs subsystem infrastructure
from sysdev devices, which are made available with this conversion.

Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Borislav Petkov <bp@amd64.org>
Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
Cc: Len Brown <lenb@kernel.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
141168c36cdee3ff23d9c7700b0edc47cb65479f 21-Dec-2011 Kevin Winchester <kjwinchester@gmail.com> x86: Simplify code by removing a !SMP #ifdefs from 'struct cpuinfo_x86'

Several fields in struct cpuinfo_x86 were not defined for the
!SMP case, likely to save space. However, those fields still
have some meaning for UP, and keeping them allows some #ifdef
removal from other files. The additional size of the UP kernel
from this change is not significant enough to worry about
keeping up the distinction:

text data bss dec hex filename
4737168 506459 972040 6215667 5ed7f3 vmlinux.o.before
4737444 506459 972040 6215943 5ed907 vmlinux.o.after

for a difference of 276 bytes for an example UP config.

If someone wants those 276 bytes back badly then it should
be implemented in a cleaner way.

Signed-off-by: Kevin Winchester <kjwinchester@gmail.com>
Cc: Steffen Persvold <sp@numascale.com>
Link: http://lkml.kernel.org/r/1324428742-12498-1-git-send-email-kjwinchester@gmail.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
0937195715713b37ec843f28d99930dd7b1e8fbe 08-Dec-2011 Borislav Petkov <borislav.petkov@amd.com> x86, MCE: Drain mcelog buffer

Add a function which drains whatever MCEs were logged in already during
boot and before the decoder chains were registered.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
3653ada5d3e173489b3a466305687cb5c44b2ab1 04-Dec-2011 Borislav Petkov <borislav.petkov@amd.com> x86, mce: Add wrappers for registering on the decode chain

No functionality change, this is done so that in a follow-on patch all
queued-up MCEs can be decoded after registering on the chain.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
66f5ddf30a59f811818656cb2833c80da0340cfa 03-Nov-2011 Luck, Tony <tony.luck@intel.com> x86/mce: Make mce_chrdev_ops 'static const'

Arjan would like to make struct file_operations const, but
mce-inject directly writes to the mce_chrdev_ops to install its
write handler. In an ideal world mce-inject would have its own
character device, but we have a sizable legacy of test scripts
that hardwire "/dev/mcelog", so it would be painful to switch to
a separate device now. Instead, this patch switches to a stub
function in the mce code, with a registration helper that
mce-inject can call when it is loaded.

Note that this would also allow for a sane process to allow
mce-inject to be unloaded again (with an unregister function,
and appropriate module_{get,put}() calls), but that is left for
potential future patches.

Reported-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/4eb2e1971326651a3b@agluck-desktop.sc.intel.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
4140c54266365e4267a2dbc5765101bba3b42896 18-Jul-2011 Borislav Petkov <borislav.petkov@amd.com> i7core_edac: Drop the edac_mce facility

Remove edac_mce pieces and use the normal MCE decoder notifier chain by
retaining the same functionality with considerably less code.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
69c60c88eeb364ebf58432f9bc38033522d58767 26-May-2011 Paul Gortmaker <paul.gortmaker@windriver.com> x86: Fix files explicitly requiring export.h for EXPORT_SYMBOL/THIS_MODULE

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>
f0cb54524366654e72c87e0a1f87c0b3ff36deb3 18-Jul-2011 Borislav Petkov <borislav.petkov@amd.com> x86, MCE: Use notifier chain only for MCE decoding

Drop the edac_mce custom hook in favor of the generic notifier
mechanism. Also, do not log the error to mcelog if the notified agent
was able to decode it.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
881e23e56764808e7ab1ed73b5d8a6700042ea38 17-Oct-2011 Borislav Petkov <borislav.petkov@amd.com> x86, microcode: Correct microcode revision format

506ed6b53e00 ("x86, intel: Output microcode revision in /proc/cpuinfo")
added microcode revision format to /proc/cpuinfo and the MCE handler in
decimal format but both AMD and Intel patch levels are handled as hex
numbers. Fix it.

Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
506ed6b53e00ba303ad778122f08e1fca7cf5efb 13-Oct-2011 Andi Kleen <ak@linux.intel.com> x86, intel: Output microcode revision in /proc/cpuinfo

I got a request to make it easier to determine the microcode
update level on Intel CPUs. This patch adds a new "microcode"
field to /proc/cpuinfo.

The microcode level is also outputed on fatal machine checks
together with the other CPUID model information.

I removed the respective code from the microcode update driver,
it just reads the field from cpu_data. Also when the microcode
is updated it fills in the new values too.

I had to add a memory barrier to native_cpuid to prevent it
being optimized away when the result is not used.

This turns out to clean up further code which already got this
information manually. This is done in followon patches.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1318466795-7393-1-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
9c48f1c629ecfa114850c03f875c6691003214de 30-Sep-2011 Don Zickus <dzickus@redhat.com> x86, nmi: Wire up NMI handlers to new routines

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>
9aaef96f61d93062556d34e15731f7d5869dd82e 17-Jun-2011 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> x86, mce: Do not call del_timer_sync() in IRQ context

del_timer_sync() can cause a deadlock when called in interrupt context.
It is used with on_each_cpu() in some parts for sysfs files like bank*,
check_interval, cmci_disabled and ignore_ce.

However, use of on_each_cpu() results in calling the function passed
as the argument in interrupt context. This causes a flood of nested
warnings from del_timer_sync() (it runs on each CPU) caused even by a
simple file access like:

$ echo 300 > /sys/devices/system/machinecheck/machinecheck0/check_interval

Fortunately, these MCE-specific files are rarely used and AFAIK only few
MCE geeks experience this warning.

To remove the warning, move timer deletion outside of the interrupt
context.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
c7cece89f1b00b56276303942f96ec67cf206e1e 08-Jun-2011 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> x86, mce: Use mce_sysdev_ prefix to group functions

There are many functions named mce_* so use a new prefix for the subset
of functions related to sysfs support.

And since f3c6ea1b06c71b43f751b36bd99345369fe911af introduces
syscore_ops, use the prefix mce_syscore for some functions related to
power management which were in sysdev_class before.

Before: After:
mce_device mce_sysdev
mce_sysclass mce_sysdev_class
mce_attrs mce_sysdev_attrs
mce_dev_initialized mce_sysdev_initialized
mce_create_device mce_sysdev_create
mce_remove_device mce_sysdev_remove

mce_suspend mce_syscore_suspend
mce_shutdown mce_syscore_shutdown
mce_resume mce_syscore_resume

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/4DEED81B.8020506@jp.fujitsu.com
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
93b62c3cf59d44850cbe9f04d58da08930e3fb0b 08-Jun-2011 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> x86, mce: Use mce_chrdev_ prefix to group functions

There are many functions named mce_* so use a new prefix for the subset
of functions dealing with the character device /dev/mcelog.

This change doesn't impact the mce-inject module because the exported
symbol mce_chrdev_ops already has the prefix, therefore it is left
unchanged.

Before: After:
mce_wait mce_chrdev_wait
mce_state_lock mce_chrdev_state_lock
open_count mce_chrdev_open_count
open_exclu mce_chrdev_open_exclu
mce_open mce_chrdev_open
mce_release mce_chrdev_release
mce_read_mutex mce_chrdev_read_mutex
mce_read mce_chrdev_read
mce_poll mce_chrdev_poll
mce_ioctl mce_chrdev_ioctl
mce_log_device mce_chrdev_device

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/4DEED7CD.3040500@jp.fujitsu.com
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
559faa6be143b8aa7a07b12f618d29fbc1c8eb0d 08-Jun-2011 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> x86, mce: Cleanup mce_read()

Use a temporary local variable m to simplify the code. No change in
logic.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/4DEED7A8.8020307@jp.fujitsu.com
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
f6783c4234e65bd6f85596d97745ccdbf041cb63 08-Jun-2011 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> x86, mce: Cleanup mce_create()/remove_device()

Use temporary local variable sysdev to simplify the code. No change in
logic.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/4DEED777.7080205@jp.fujitsu.com
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
3a97fc34130326da87b20de5d0259c35406707ce 08-Jun-2011 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> x86, mce: Check the result of ancient_init()

Because "ancient CPUs" like p5 and winchip don't have X86_FEATURE_MCA
(I suppose so), mcheck_cpu_init() on such CPUs will return at check of
mce_available() after __mcheck_cpu_ancient_init().

It is hard to know this implicit behavior without knowing the CPUs
well. So make it clear that we leave mcheck_cpu_init() when the CPU is
initialized in __mcheck_cpu_ancient_init().

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/4DEED74B.20502@jp.fujitsu.com
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
b8325c5b110d7ff460b79588e7e9afdcc73d5c3c 08-Jun-2011 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> x86, mce: Introduce mce_gather_info()

This patch introduces mce_gather_info() which is to be called at the
beginning of error handling and gathers minimum error information from
proper error registers (and saved registers).

As the result of mce_get_rip() is integrated, unnecessary zeroing
is removed. This also takes care of saving RIP which is required to
make some decision about error severity for SRAR errors, instead of
retrieving it later in the handler.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/4DEED71A.1060906@jp.fujitsu.com
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
2b90e77eaee8809073db5cf43ac9795cc2054dc0 08-Jun-2011 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> x86, mce: Replace MCM_ with MCI_MISC_

Follow other MCi register defines. Plus define MCI_MISC_ADDR_LSB() and
MCI_MISC_ADDR_MODE().

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/4DEED6E8.9090509@jp.fujitsu.com
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
b77e70bf3535e0bd5472e0681f41cce4ae0598bb 08-Jun-2011 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> x86, mce: Replace MCE_SELF_VECTOR by irq_work

The MCE handler uses a special vector for self IPI to invoke
post-emergency processing in an interrupt context, e.g. call an
NMI-unsafe function, wakeup loggers, schedule time-consuming work for
recovery, etc.

This mechanism is now generalized by the following commit:

> e360adbe29241a0194e10e20595360dd7b98a2b3
> Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
> Date: Thu Oct 14 14:01:34 2010 +0800
>
> irq_work: Add generic hardirq context callbacks
>
> Provide a mechanism that allows running code in IRQ context. It is
> most useful for NMI code that needs to interact with the rest of the
> system -- like wakeup a task to drain buffers.
:

So change to use provided generic mechanism.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/4DEED6B2.6080005@jp.fujitsu.com
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
dffa4b2f62ff28c982144c7033001b1ece4d3532 20-Apr-2011 Borislav Petkov <borislav.petkov@amd.com> x86, mce: Drop the default decoding notifier

The default notifier doesn't make a lot of sense to call in the
correctable errors case. Drop it and emit the mcelog decoding
hint only in the uncorrectable errors case and when no notifier
is registered. Also, limit issuing the "mcelog --ascii" message
in the rare case when we dump unreported CEs before panicking.

While at it, remove unused old x86_mce_decode_callback from the
header.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Nagananda Chumbalkar <Nagananda.Chumbalkar@hp.com>
Cc: Russ Anderson <rja@sgi.com>
Link: http://lkml.kernel.org/r/20110420102349.GB1361@aftab
Signed-off-by: Ingo Molnar <mingo@elte.hu>
7b70bd3441437b7bc04fc9d321e17c8ed0e8f958 18-Apr-2011 Borislav Petkov <borislav.petkov@amd.com> x86, MCE: Do not taint when handling correctable errors

Correctable errors are considered something rather normal on
modern hardware these days. Even more importantly, correctable
errors mean exactly that - they've been corrected by the
hardware - and there's no need to taint the kernel since
execution hasn't been compromised so far.

Also, drop tainting in the thermal throttling code for a similar
reason: crossing a thermal threshold does not mean corruption.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Acked-by: Nagananda Chumbalkar <Nagananda.Chumbalkar@hp.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Russ Anderson <rja@sgi.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/1303135222-17118-1-git-send-email-bp@amd64.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
a4dd99250dc49031e6a92a895dbcc230a4832083 01-Apr-2011 Paul E. McKenney <paulmck@linux.vnet.ibm.com> rcu: create new rcu_access_index() and use in mce

The MCE subsystem needs to sample an RCU-protected index outside of
any protection for that index. If this was a pointer, we would use
rcu_access_pointer(), but there is no corresponding rcu_access_index().
This commit therefore creates an rcu_access_index() and applies it
to MCE.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Zdenek Kabelac <zkabelac@redhat.com>
f3c6ea1b06c71b43f751b36bd99345369fe911af 23-Mar-2011 Rafael J. Wysocki <rjw@sisk.pl> x86: Use syscore_ops instead of sysdev classes and sysdevs

Some subsystems in the x86 tree need to carry out suspend/resume and
shutdown operations with one CPU on-line and interrupts disabled and
they define sysdev classes and sysdevs or sysdev drivers for this
purpose. This leads to unnecessarily complicated code and excessive
memory usage, so switch them to using struct syscore_ops objects for
this purpose instead.

Generally, there are three categories of subsystems that use
sysdevs for implementing PM operations: (1) subsystems whose
suspend/resume callbacks ignore their arguments entirely (the
majority), (2) subsystems whose suspend/resume callbacks use their
struct sys_device argument, but don't really need to do that,
because they can be implemented differently in an arguably simpler
way (io_apic.c), and (3) subsystems whose suspend/resume callbacks
use their struct sys_device argument, but the value of that argument
is always the same and could be ignored (microcode_core.c). In all
of these cases the subsystems in question may be readily converted to
using struct syscore_ops objects for power management and shutdown.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
0d2eb44f631d9d0a826efa3156f157477fdaecf4 17-Mar-2011 Lucas De Marchi <lucas.de.marchi@gmail.com> x86: Fix common misspellings

They were generated by 'codespell' and then manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: trivial@kernel.org
LKML-Reference: <1300389856-1099-3-git-send-email-lucas.demarchi@profusion.mobi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
7b543a5334ff4ea2e3ad3b777fc23cdb8072a988 18-Dec-2010 Tejun Heo <tj@kernel.org> x86: Replace uses of current_cpu_data with this_cpu ops

Replace all uses of current_cpu_data with this_cpu operations on the
per cpu structure cpu_info. The scala accesses are replaced with the
matching this_cpu ops which results in smaller and more efficient
code.

In the long run, it might be a good idea to remove cpu_data() macro
too and use per_cpu macro directly.

tj: updated description

Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
0a3aee0da4402aa19b66e458038533c896fb80c6 18-Dec-2010 Tejun Heo <tj@kernel.org> x86: Use this_cpu_ops to optimize code

Go through x86 code and replace __get_cpu_var and get_cpu_var
instances that refer to a scalar and are not used for address
determinations.

Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
6038f373a3dc1f1c26496e60b6c40b164716f07e 15-Aug-2010 Arnd Bergmann <arnd@arndb.de> llseek: automatically add .llseek fop

All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.

The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.

New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time. Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.

The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.

Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.

Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.

===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
// but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}

@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}

@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
*off = E
|
*off += E
|
func(..., off, ...)
|
E = *off
)
...+>
}

@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}

@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
*off = E
|
*off += E
|
func(..., off, ...)
|
E = *off
)
...+>
}

@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}

@ fops0 @
identifier fops;
@@
struct file_operations fops = {
...
};

@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
.llseek = llseek_f,
...
};

@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
.read = read_f,
...
};

@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
.write = write_f,
...
};

@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
.open = open_f,
...
};

// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
... .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};

@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
... .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};

// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
... .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};

// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};

// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};

@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+ .llseek = default_llseek, /* write accesses f_pos */
};

// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////

@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
.write = write_f,
.read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};

@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};

@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};

@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>
98a5ae2d99b78d29d2d31283cd8b481a44f41fd3 18-May-2010 Borislav Petkov <borislav.petkov@amd.com> x86, mce: Notify about corrected events too

Notify all parties registered on the mce decoder chain about logged
correctable MCEs.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Acked-by: Doug Thompson <dougthompson@xmission.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
ec8c27e04f89a7575ca2c4facb99152e03d6a99c 30-Apr-2010 Paul E. McKenney <paulmck@linux.vnet.ibm.com> mce: convert to rcu_dereference_index_check()

The mce processing applies rcu_dereference_check() to integers used as
array indices. This patch therefore moves mce to the new RCU API
rcu_dereference_index_check() that avoids the sparse processing that
would otherwise result in compiler errors.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
a2d7b0d4852536273b65d16fe179c65184fe5e2d 08-Jun-2010 Huang Ying <ying.huang@intel.com> x86, mce: Use HW_ERR in MCE handler

Use HW_ERR printk prefix in MCE handler. To make it more explicit that
this is hardware error instead of software error.

Signed-off-by: Huang Ying <ying.huang@intel.com>
LKML-Reference: <1275978939.3444.668.camel@yhuang-dev.sh.intel.com>
Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
482908b49ebfa453dd0455910c951c750567c05d 18-May-2010 Huang Ying <ying.huang@intel.com> ACPI, APEI, Use ERST for persistent storage of MCE

Traditionally, fatal MCE will cause Linux print error log to console
then reboot. Because MCE registers will preserve their content after
warm reboot, the hardware error can be logged to disk or network after
reboot. But system may fail to warm reboot, then you may lose the
hardware error log. ERST can help here. Through saving the hardware
error log into flash via ERST before go panic, the hardware error log
can be gotten from the flash after system boot successful again.

The fatal MCE processing procedure with ERST involved is as follow:

- Hardware detect error, MCE raised
- MCE read MCE registers, check error severity (fatal), prepare error record
- Write MCE error record into flash via ERST
- Go panic, then trigger system reboot
- System reboot, /sbin/mcelog run, it reads /dev/mcelog to check flash
for error record of previous boot via ERST, and output and clear
them if available
- /sbin/mcelog logs error records into disk or network

ERST only accepts CPER record format, but there is no pre-defined CPER
section can accommodate all information in struct mce, so a customized
section type is defined to hold struct mce inside a CPER record as an
error section.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
696e409dbd1ce325129c5030267365619364dfa0 23-Jul-2009 Mauro Carvalho Chehab <mchehab@redhat.com> edac_mce: Add an interface driver to report mce errors via edac

edac_mce module is an interface module that gets mcelog data and
forwards to any registered edac module that expects to receive data via
mce.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
402af0d7c692ddcfa2333e93d3f275ebd0487926 21-Apr-2010 Jan Beulich <JBeulich@novell.com> x86, asm: Introduce and use percpu_inc()

... generating slightly smaller code.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <4BCF261F020000780003B33C@vpn.id2.novell.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
5a0e3ad6af8660be21ca98a971cd00f331318c05 24-Mar-2010 Tejun Heo <tj@kernel.org> include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2aa2b50dd62b5d0675bd7453fbeb5732dc2d7866 14-Mar-2010 Ingo Molnar <mingo@elte.hu> x86/mce: Fix build bug with CONFIG_PROVE_LOCKING=y && CONFIG_X86_MCE_INTEL=y

Commit f56e8a076 "x86/mce: Fix RCU lockdep splats" introduced the
following build bug:

arch/x86/kernel/cpu/mcheck/mce.c: In function 'mce_log':
arch/x86/kernel/cpu/mcheck/mce.c:166: error: 'mce_read_mutex' undeclared (first use in this function)
arch/x86/kernel/cpu/mcheck/mce.c:166: error: (Each undeclared identifier is reported only once
arch/x86/kernel/cpu/mcheck/mce.c:166: error: for each function it appears in.)

Move the in-the-middle-of-file lock variable up to the variable
definition section, the top of the .c file.

Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1267830207-9474-3-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
f56e8a0765cc4374e02f4e3a79e2427b5096b075 06-Mar-2010 Paul E. McKenney <paulmck@linux.vnet.ibm.com> x86/mce: Fix RCU lockdep splats

Create an rcu_dereference_check_mce() that checks for RCU-sched
read side and mce_read_mutex being held on update side. Replace
uses of rcu_dereference() in arch/x86/kernel/cpu/mcheck/mce.c
with this new macro.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1267830207-9474-3-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
a07e4156a2ee6359d31a44946d7ee7f85dbf6bca 12-Feb-2010 Eric W. Biederman <ebiederm@xmission.com> sysfs: Use sysfs_attr_init and sysfs_bin_attr_init on dynamic attributes

These are the non-static sysfs attributes that exist on
my test machine. Fix them to use sysfs_attr_init or
sysfs_bin_attr_init as appropriate. It simply requires
making a sysfs attribute present to see this. So this
is a little bit tedious but otherwise not too bad.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
5c0e9f28da84c68ce0ae68b7a75faaf862e156e2 08-Dec-2009 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> x86, mce: fix confusion between bank attributes and mce attributes

Commit cebe182033f156b430952370fb0f9dbe6e89b081 had an unnecessary,
wrong change: &mce_banks[i].attr is equivalent to the former
bank_attrs[i], not to mce_attrs[i].

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: Andi Kleen <andi@firstfloor.org>
LKML-Reference: <4B1E05CC.4040703@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
bc09effabf0c5c6c7021e5ef9af15a23579b32a8 08-Dec-2009 Jan Beulich <jbeulich@novell.com> x86/mce: Set up timer unconditionally

mce_timer must be passed to setup_timer() in all cases, no
matter whether it is going to be actually used. Otherwise, when
the CPU gets brought down, its call to del_timer_sync() will
never return, as the timer won't have a base associated, and
hence lock_timer_base() will loop infinitely.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: <stable@kernel.org>
LKML-Reference: <4B1DB831.2030801@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
fe5ed91ddce85a0ed0e4f92c10b099873ef62167 03-Dec-2009 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> x86, mce: don't restart timer if disabled

Even it is in error path unlikely taken, add_timer_on() at
CPU_DOWN_FAILED* needs to be skipped if mce_timer is disabled.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: <stable@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
767df1bdd8cbff2c8c40c9ac8295bbdaa5fb24c4 26-Nov-2009 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> x86, mce: Add __cpuinit to hotplug callback functions

The mce_disable_cpu() and mce_reenable_cpu() are called only
from mce_cpu_callback() which is marked as __cpuinit.
So these functions can be __cpuinit too.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Andi Kleen <ak@linux.intel.com>
LKML-Reference: <4B0E3C4E.4090809@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
cffd377e5879ea58522224a785a083f201afd80e 12-Nov-2009 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> x86, mce: Fix __init annotations

The intel_init_thermal() is called from resume path, so it
cannot be marked as __init.

OTOH mce_banks_init() is only called from
__mcheck_cpu_cap_init() which is marked as __cpuinit, so it can
be also marked as __cpuinit.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: Yong Wang <yong.y.wang@linux.intel.com>
LKML-Reference: <4AFBB0B8.2070501@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
a2202aa29289db64ca7988b12343158b67b27f10 10-Nov-2009 Yong Wang <yong.y.wang@linux.intel.com> x86: Under BIOS control, restore AP's APIC_LVTTHMR to the BSP value

On platforms where the BIOS handles the thermal monitor interrupt,
APIC_LVTTHMR on each logical CPU is programmed to generate a SMI
and OS must not touch it.

Unfortunately AP bringup sequence using INIT-SIPI-SIPI clears all
the LVT entries except the mask bit. Essentially this results in
all LVT entries including the thermal monitoring interrupt set
to masked (clearing the bios programmed value for APIC_LVTTHMR).

And this leads to kernel take over the thermal monitoring
interrupt on AP's but not on BSP (leaving the bios programmed
value only on BSP).

As a result of this, we have seen system hangs when the thermal
monitoring interrupt is generated.

Fix this by reading the initial value of thermal LVT entry on
BSP and if bios has taken over the control, then program the
same value on all AP's and leave the thermal monitoring
interrupt control on all the logical cpu's to the bios.

Signed-off-by: Yong Wang <yong.y.wang@intel.com>
Reviewed-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Borislav Petkov <borislav.petkov@amd.com>
Cc: Arjan van de Ven <arjan@infradead.org>
LKML-Reference: <20091110013824.GA24940@ywang-moblin2.bj.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: stable@kernel.org
b33a6363649f0ff83ec81597ea7fe7e688f973cb 16-Oct-2009 Borislav Petkov <borislav.petkov@amd.com> x86, mce: Add a global MCE init helper

Add an early initcall (pre SMP) which sets up global MCE
functionality.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Cc: Andi Kleen <andi@firstfloor.org>
LKML-Reference: <1255689093-26921-2-git-send-email-borislav.petkov@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
5e09954a9acc3b435ffe318b95afd3c02fae069f 16-Oct-2009 Borislav Petkov <borislav.petkov@amd.com> x86, mce: Fix up MCE naming nomenclature

Prefix global/setup routines with "mcheck_" thus differentiating
from the internal facilities prefixed with "mce_". Also, prefix
the per cpu calls with mcheck_cpu and rename them to reflect the
MCE setup hierarchy of calls better.

There should be no functionality change resulting from this
patch.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Cc: Andi Kleen <andi@firstfloor.org>
LKML-Reference: <1255689093-26921-1-git-send-email-borislav.petkov@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
93ae5012a79b11e7fc855b52c7ce1e16fe1540b0 15-Oct-2009 Roland Dreier <rdreier@cisco.com> x86: Don't print number of MCE banks for every CPU

The MCE initialization code explicitly says it doesn't handle
asymmetric configurations where different CPUs support different
numbers of MCE banks, and it prints a big warning in that case.

Therefore, printing the "mce: CPU supports <x> MCE banks"
message into the kernel log for every CPU is pure redundancy
that clutters the log significantly for systems with lots of
CPUs.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
LKML-Reference: <adaeip473qt.fsf@cisco.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
8968f9d3dc23d9a1821d97c6f11e72a59382e56c 13-Oct-2009 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> perf_event, x86, mce: Use TRACE_EVENT() for MCE logging

This approach is the first baby step towards solving many of the
structural problems the x86 MCE logging code is having today:

- It has a private ring-buffer implementation that has a number
of limitations and has been historically fragile and buggy.

- It is using a quirky /dev/mcelog ioctl driven ABI that is MCE
specific. /dev/mcelog is not part of any larger logging
framework and hence has remained on the fringes for many years.

- The MCE logging code is still very unclean partly due to its ABI
limitations. Fields are being reused for multiple purposes, and
the whole message structure is limited and x86 specific to begin
with.

All in one, the x86 tree would like to move away from this private
implementation of an event logging facility to a broader framework.

By using perf events we gain the following advantages:

- Multiple user-space agents can access MCE events. We can have an
mcelog daemon running but also a system-wide tracer capturing
important events in flight-recorder mode.

- Sampling support: the kernel and the user-space call-chain of MCE
events can be stored and analyzed as well. This way actual patterns
of bad behavior can be matched to precisely what kind of activity
happened in the kernel (and/or in the app) around that moment in
time.

- Coupling with other hardware and software events: the PMU can track a
number of other anomalies - monitoring software might chose to
monitor those plus the MCE events as well - in one coherent stream of
events.

- Discovery of MCE sources - tracepoints are enumerated and tools can
act upon the existence (or non-existence) of various channels of MCE
information.

- Filtering support: we just subscribe to and act upon the events we
are interested in. Then even on a per event source basis there's
in-kernel filter expressions available that can restrict the amount
of data that hits the event channel.

- Arbitrary deep per cpu buffering of events - we can buffer 32
entries or we can buffer as much as we want, as long as we have
the RAM.

- An NMI-safe ring-buffer implementation - mappable to user-space.

- Built-in support for timestamping of events, PID markers, CPU
markers, etc.

- A rich ABI accessible over system call interface. Per cpu, per task
and per workload monitoring of MCE events can be done this way. The
ABI itself has a nice, meaningful structure.

- Extensible ABI: new fields can be added without breaking tooling.
New tracepoints can be added as the hardware side evolves. There's
various parsers that can be used.

- Lots of scheduling/buffering/batching modes of operandi for MCE
events. poll() support. mmap() support. read() support. You name it.

- Rich tooling support: even without any MCE specific extensions added
the 'perf' tool today offers various views of MCE data: perf report,
perf stat, perf trace can all be used to view logged MCE events and
perhaps correlate them to certain user-space usage patterns. But it
can be used directly as well, for user-space agents and policy action
in mcelog, etc.

With this we hope to achieve significant code cleanup and feature
improvements in the MCE code, and we hope to be able to drop the
/dev/mcelog facility in the end.

This patch is just a plain dumb dump of mce_log() records to
the tracepoints / perf events framework - a first proof of
concept step.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
LKML-Reference: <4AD42A0D.7050104@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
fb2531953fd8855abdcf458459020fd382c5deca 07-Oct-2009 Borislav Petkov <borislav.petkov@amd.com> mce, edac: Use an atomic notifier for MCEs decoding

Add an atomic notifier which ensures proper locking when conveying
MCE info to EDAC for decoding. The actual notifier call overrides a
default, negative priority notifier.

Note: make sure we register the default decoder only once since
mcheck_init() runs on each CPU.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <20091003065752.GA8935@liondog.tnic>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
f436f8bb73138bc74eb1c6527723e00988ad8a8a 01-Oct-2009 Ingo Molnar <mingo@elte.hu> x86: EDAC: MCE: Fix MCE decoding callback logic

Make decoding of MCEs happen only on AMD hardware by registering a
non-default callback only on CPU families which support it.

While looking at the interaction of decode_mce() with the other MCE
code i also noticed a few other things and made the following
cleanups/fixes:

- Fixed the mce_decode() weak alias - a weak alias is really not
good here, it should be a proper callback. A weak alias will be
overriden if a piece of code is built into the kernel - not
good, obviously.

- The patch initializes the callback on AMD family 10h and 11h.

- Added the more correct fallback printk of:

No support for human readable MCE decoding on this CPU type.
Transcribe the message and run it through 'mcelog --ascii' to decode.

On CPUs that dont have a decoder.

- Made the surrounding code more readable.

Note that the callback allows us to have a default fallback -
without having to check the CPU versions during the printout
itself. When an EDAC module registers itself, it can install the
decode-print function.

(there's no unregister needed as this is core code.)

version -v2 by Borislav Petkov:

- add K8 to the set of supported CPUs

- always build in edac_mce_amd since we use an early_initcall now

- fix checkpatch warnings

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andi Kleen <andi@firstfloor.org>
LKML-Reference: <20091001141432.GA11410@aftab>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
e207e143e2fb6a2790b1ce3687c8aedc3ddc357b 30-Sep-2009 Linus Torvalds <torvalds@linux-foundation.org> Revert "x86, mce: do not compile mcelog message on AMD"

This reverts commit 22223c9b417be5fd0ab2cf9ad17eb7bd1e19f7b9, as
requested by Andi Kleen:

"Obviously kernels compiled with AMD support can still run on non AMD
systems, so messages like this can never be removed at compile time."

Requsted-by: Andi Kleen <andi@firstfloor.org>
Cc: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11868a2dc4f5e4f2f652bfd259e1360193fcee62 23-Sep-2009 Ingo Molnar <mingo@elte.hu> x86: mce: Use safer ways to access MCE registers

Use rdmsrl_safe() when accessing MCE registers. While in
theory we always 'know' which ones are safe to access from
the capability bits, there's a lot of hardware variations
and reality might differ from theory, as it did in this case:

http://bugzilla.kernel.org/show_bug.cgi?id=14204

[ 0.010016] mce: CPU supports 5 MCE banks
[ 0.011029] general protection fault: 0000 [#1]
[ 0.011998] last sysfs file:
[ 0.011998] Modules linked in:
[ 0.011998]
[ 0.011998] Pid: 0, comm: swapper Not tainted (2.6.31_router #1) HP Vectra
[ 0.011998] EIP: 0060:[<c100d9b9>] EFLAGS: 00010246 CPU: 0
[ 0.011998] EIP is at mce_rdmsrl+0x19/0x60
[ 0.011998] EAX: 00000000 EBX: 00000001 ECX: 00000407 EDX: 08000000
[ 0.011998] ESI: 00000000 EDI: 8c000000 EBP: 00000405 ESP: c17d5eac

So WARN_ONCE() instead of crashing the box.

( also fix a number of stylistic inconsistencies in the code. )

Note, we might still crash in wrmsrl() if we get that far, but
we shouldnt if the registers are truly inaccessible.

Reported-by: GNUtoo <GNUtoo@no-log.org>
Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
LKML-Reference: <bug-14204-5438@http.bugzilla.kernel.org/>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
22223c9b417be5fd0ab2cf9ad17eb7bd1e19f7b9 28-Jul-2009 Borislav Petkov <borislav.petkov@amd.com> x86, mce: do not compile mcelog message on AMD

Now that decoding is done in-kernel, suppress mcelog message part.

CC: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
549d042df240dfb4203bab40ad44f9336751b7d6 24-Jul-2009 Borislav Petkov <borislav.petkov@amd.com> x86, mce: pass mce info to EDAC for decoding

Move NB decoder along with required defines to EDAC MCE core. Add
registration routines for further decoding of the MCE info in the AMD64
EDAC module.

CC: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
680b6cfd3cee30a7d997d49430fb73af84523853 26-Aug-2009 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> x86, mce: CE in last bank prevents panic by unknown MCE

If MCE handler is called but none of mces_seen have machine
check event which might signal the MCE (i.e. event higher than
MCE_KEEP_SEVERITY), panic with "Machine check from unknown
source" will be taken since the MCE is assumed to be signaled
from external agent or so.

Usually mces_seen never point MCE_KEEP_SEVERITY event such as
CE. But it can happen because initial value of mces_seen is
accidentally modified by mce_no_way_out() - in case if
mce_no_way_out() run through all banks and the last bank has
the CE, mces_seen points the CE and the "panic by unknown" will
not be taken.

This patch fixes this undesired behavior, and clarifies the logic.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Dongming <jin.dongming@np.css.fujitsu.com>
LKML-Reference: <4A94E244.3020301@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reported-by: Jin Dongming <jin.dongming@np.css.fujitsu.com>
e412cd257e0d51e0ecbb89f50953835b5a0681b2 17-Aug-2009 Ingo Molnar <mingo@elte.hu> x86, mce: Don't initialize MCEs on unknown CPUs

An older test-box started hanging at the following point during
bootup:

[ 0.022996] Mount-cache hash table entries: 512
[ 0.024996] Initializing cgroup subsys debug
[ 0.025996] Initializing cgroup subsys cpuacct
[ 0.026995] Initializing cgroup subsys devices
[ 0.027995] Initializing cgroup subsys freezer
[ 0.028995] mce: CPU supports 5 MCE banks

I've bisected it down to commit 4efc0670 ("x86, mce: use 64bit
machine check code on 32bit"), which utilizes the MCE code on
32-bit systems too.

The problem is caused by this detail in my config:

# CONFIG_CPU_SUP_INTEL is not set

This disables the quirks in mce_cpu_quirks() but still enables
MCE support - which then hangs due to the missing quirk
workaround needed on this CPU:

if (c->x86 == 6 && c->x86_model < 0x1A && banks > 0)
mce_banks[0].init = 0;

The safe solution is to not initialize MCEs if we dont know on
what CPU we are running (or if that CPU's support code got
disabled in the config).

Also be a bit more defensive on 32-bit systems: dont do a
boot-time dump of pending MCEs not just on the specific system
that we found a problem with (Pentium-M), but earlier ones as
well.

Now this problem is probably not common and disabling CPU
support is rare - but still being more defensive in something
we turned on for a wide range of CPUs is prudent.

Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
LKML-Reference: Message-ID: <4A88E3E4.40506@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
c7f6fa44115d401e89db730f357629d39f8e4ba6 28-Jul-2009 Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> x86, mce: don't log boot MCEs on Pentium M (model == 13) CPUs

On my legacy Pentium M laptop (Acer Extensa 2900) I get bogus MCE on a cold
boot with CONFIG_X86_NEW_MCE enabled, i.e. (after decoding it with mcelog):

MCE 0
HARDWARE ERROR. This is *NOT* a software problem!
Please contact your hardware vendor
CPU 0 BANK 1 MCG status:
MCi status:
Error overflow
Uncorrected error
Error enabled
Processor context corrupt
MCA: Data CACHE Level-1 UNKNOWN Error
STATUS f200000000000195 MCGSTATUS 0

[ The other STATUS values observed: f2000000000001b5 (... UNKNOWN error)
and f200000000000115 (... READ Error).

To verify that this is not a CONFIG_X86_NEW_MCE bug I also modified
the CONFIG_X86_OLD_MCE code (which doesn't log any MCEs) to dump
content of STATUS MSR before it is cleared during initialization. ]

Since the bogus MCE results in a kernel taint (which in turn disables
lockdep support) don't log boot MCEs on Pentium M (model == 13) CPUs
by default ("mce=bootlog" boot parameter can be be used to get the old
behavior).

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Reviewed-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
bf783f9f7d33576815bc89f9f1856a7309ea2f17 31-Jul-2009 Huang Ying <ying.huang@intel.com> x86, mce: Fake panic support for MCE testing

If "fake panic" mode is turned on, just log panic message instead of
go real panic. This is used for testing only, so that the test suite
can check for the correct panic message and do regression testing for
MCE would go panic.

This patch is based on x86-tip.git/mce.

ChangeLog:

v5:

- Rebased on x86-tip.git/mce

v4:

- Move config file from sysfs to debugfs

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
5be9ed251f58881dfc3dd6742a81ff9ad1a7bb04 31-Jul-2009 Huang Ying <ying.huang@intel.com> x86, mce: Move debugfs mce dir creating to mce.c

Because more debugfs files under mce dir will be create in mce.c.

ChangeLog:

v5:

- Rebased on x86-tip.git/mce

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
419d6162c0c0103fa2f44f6691dff9cac14c650d 28-Jul-2009 Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> x86, mce: add missing __cpuinit tags

mce_cap_init() and mce_cpu_quirks() can be tagged with __cpuinit.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Reviewed-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
e3346fc48204d780f92527d06df8bf6f28d603ec 28-Jul-2009 Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> x86, mce: fix "mce" boot option handling for CONFIG_X86_NEW_MCE

"mce argument mce ignored. Please use /sys" message shouldn't
be printed when using "mce" boot option.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Reviewed-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
94699b04eddd4b247d871930431d6fa1a46c175e 28-Jul-2009 Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> x86, mce: don't log boot MCEs on Pentium M (model == 13) CPUs

On my legacy Pentium M laptop (Acer Extensa 2900) I get bogus MCE on a cold
boot with CONFIG_X86_NEW_MCE enabled, i.e. (after decoding it with mcelog):

MCE 0
HARDWARE ERROR. This is *NOT* a software problem!
Please contact your hardware vendor
CPU 0 BANK 1 MCG status:
MCi status:
Error overflow
Uncorrected error
Error enabled
Processor context corrupt
MCA: Data CACHE Level-1 UNKNOWN Error
STATUS f200000000000195 MCGSTATUS 0

[ The other STATUS values observed: f2000000000001b5 (... UNKNOWN error)
and f200000000000115 (... READ Error).

To verify that this is not a CONFIG_X86_NEW_MCE bug I also modified
the CONFIG_X86_OLD_MCE code (which doesn't log any MCEs) to dump
content of STATUS MSR before it is cleared during initialization. ]

Since the bogus MCE results in a kernel taint (which in turn disables
lockdep support) don't log boot MCEs on Pentium M (model == 13) CPUs
by default ("mce=bootlog" boot parameter can be be used to get the old
behavior).

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Reviewed-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
e9084ec98bb9aa3abc6cf73181177780ce7546f8 16-Jul-2009 Jan Beulich <JBeulich@novell.com> x86, mce: Fix set_trigger() accessor

Fix the condition checking the result of strchr() (which previously
could result in an oops), and make the function return the number of
bytes actively used.

[ Impact: fix oops ]

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <andi@firstfloor.org>
LKML-Reference: <4A5F04B7020000780000AB59@vpn.id2.novell.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
a2d32bcbc008aa0f9c301a7c6f3494cb23e6af54 09-Jul-2009 Andi Kleen <andi@firstfloor.org> x86: mce: macros to compute banks MSRs

Instead of open coded calculations for bank MSRs hide the indexing of higher
banks MCE register MSRs in new macros.

No semantic changes.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
cebe182033f156b430952370fb0f9dbe6e89b081 09-Jul-2009 Andi Kleen <andi@firstfloor.org> x86: mce: Move per bank data in a single datastructure

This addresses one of the leftover review comments.

Move the per bank data into a single structure. This avoids
several separate variables and also separate allocation of sysfs objects.

I didn't move the CMCI ownership information so far because
that would have needed some non trivial changes in the algorithms.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
9eda8cb3ac235217e4ffa01cb9cedee1c1550599 09-Jul-2009 Andi Kleen <andi@firstfloor.org> x86: mce: Move code in mce.c

Now that the X86_OLD_MCE ifdefs are gone move some code that
used to be outside the big ifdef to a more natural place
near its user.

No code change.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
5bb38adcb54cf7192b154368ad62982caa11ca0b 09-Jul-2009 Andi Kleen <andi@firstfloor.org> x86: mce: Remove old i386 machine check code

As announced in feature-remove-schedule.txt remove CONFIG_X86_OLD_MCE

This patch only removes code.

The ancient machine check code for very old systems that are not supported
by CONFIG_X86_NEW_MCE is still kept.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
ad361c9884e809340f6daca80d56a9e9c871690a 06-Jul-2009 Joe Perches <joe@perches.com> Remove multiple KERN_ prefixes from printk formats

Commit 5fd29d6ccbc98884569d6f3105aeca70858b3e0f ("printk: clean up
handling of log-levels and newlines") changed printk semantics. printk
lines with multiple KERN_<level> prefixes are no longer emitted as
before the patch.

<level> is now included in the output on each additional use.

Remove all uses of multiple KERN_<level>s in formats.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
5be6066a7f8d917db347d94f1b359b9b70dcb572 24-Jun-2009 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> x86, mce: percpu mcheck_timer should be pinned

If CONFIG_NO_HZ + CONFIG_SMP, timer added via add_timer() might
be migrated on other cpu. Use add_timer_on() instead.

Avoids the following failure:

Maciej Rutecki wrote:
> > After normal boot I try:
> >
> > echo 1 > /sys/devices/system/machinecheck/machinecheck0/check_interval
> >
> > I found this in dmesg:
> >
> > [ 141.704025] ------------[ cut here ]------------
> > [ 141.704039] WARNING: at arch/x86/kernel/cpu/mcheck/mce.c:1102
> > mcheck_timer+0xf5/0x100()

Reported-by: Maciej Rutecki <maciej.rutecki@gmail.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Tested-by: Maciej Rutecki <maciej.rutecki@gmail.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
245b2e70eabd797932adb263a65da0bab3711753 24-Jun-2009 Tejun Heo <tj@kernel.org> percpu: clean up percpu variable definitions

Percpu variable definition is about to be updated such that all percpu
symbols including the static ones must be unique. Update percpu
variable definitions accordingly.

* as,cfq: rename ioc_count uniquely

* cpufreq: rename cpu_dbs_info uniquely

* xen: move nesting_count out of xen_evtchn_do_upcall() and rename it

* mm: move ratelimits out of balance_dirty_pages_ratelimited_nr() and
rename it

* ipv4,6: rename cookie_scratch uniquely

* x86 perf_counter: rename prev_left to pmc_prev_left, irq_entry to
pmc_irq_entry and nmi_entry to pmc_nmi_entry

* perf_counter: rename disable_count to perf_disable_count

* ftrace: rename test_event_disable to ftrace_test_event_disable

* kmemleak: rename test_pointer to kmemleak_test_pointer

* mce: rename next_interval to mce_next_interval

[ Impact: percpu usage cleanups, no duplicate static percpu var names ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: linux-mm <linux-mm@kvack.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Andi Kleen <andi@firstfloor.org>
a95436e44a76a32dcbe7c8df59701ddde53017c1 21-Jun-2009 Borislav Petkov <borislav.petkov@amd.com> x86, mce: use atomic_inc_return() instead of add by 1

Use atomic_inc_return() instead of atomic_add_return() by 1.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
b1f49f9582f9be6de5055cfa97eabf6246f2eaf7 18-Jun-2009 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> x86, mce: fix error path in mce_create_device()

Don't skip removing mce_attrs in route from error2.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
e92fae064ae42b2a4a77646f7655bca4c87bb1eb 18-Jun-2009 Yinghai Lu <yinghai@kernel.org> x86: use zalloc_cpumask_var for mce_dev_initialized

We need a cleared cpu_mask to record if mce is initialized, especially
when MAXSMP is used.

used zalloc_... instead

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: stable@kernel.org
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
74b602c7147212a7495879ec23fe6c2d3b470e06 17-Jun-2009 Yinghai Lu <yinghai@kernel.org> x86: fix duplicated sysfs attribute

The sysfs attribute cmci_disabled was accidentall turned into a
duplicate of ignore_ce, breaking all other attributes.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
203abd67b75f7714ce98ab0cdbd6cfd7ad79dec4 15-Jun-2009 Andi Kleen <andi@firstfloor.org> x86: mce: Handle banks == 0 case in K7 quirk

Vegard Nossum reported:

> I get an MCE-related crash like this in latest linus tree:
>
> [ 0.115341] CPU: L1 I Cache: 64K (64 bytes/line), D cache 64K (64 bytes/line)
> [ 0.116396] CPU: L2 Cache: 512K (64 bytes/line)
> [ 0.120570] mce: CPU supports 0 MCE banks
> [ 0.124870] BUG: unable to handle kernel NULL pointer dereference at 00000000 00000010
> [ 0.128001] IP: [<ffffffff813b98ad>] mcheck_init+0x278/0x320
> [ 0.128001] PGD 0
> [ 0.128001] Thread overran stack, or stack corrupted
> [ 0.128001] Oops: 0002 [#1] PREEMPT SMP
> [ 0.128001] last sysfs file:
> [ 0.128001] CPU 0
> [ 0.128001] Modules linked in:
> [ 0.128001] Pid: 0, comm: swapper Not tainted 2.6.30 #426
> [ 0.128001] RIP: 0010:[<ffffffff813b98ad>] [<ffffffff813b98ad>] mcheck_init+0x278/0x320
> [ 0.128001] RSP: 0018:ffffffff81595e38 EFLAGS: 00000246
> [ 0.128001] RAX: 0000000000000010 RBX: ffffffff8158f900 RCX: 0000000000000000
> [ 0.128001] RDX: 0000000000000000 RSI: 00000000000000ff RDI: 0000000000000010
> [ 0.128001] RBP: ffffffff81595e68 R08: 0000000000000001 R09: 0000000000000000
> [ 0.128001] R10: 0000000000000010 R11: 0000000000000000 R12: 0000000000000000
> [ 0.128001] R13: 00000000ffffffff R14: 0000000000000000 R15: 0000000000000000
> [ 0.128001] FS: 0000000000000000(0000) GS:ffff880002288000(0000) knlGS:00000
> 00000000000
> [ 0.128001] CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b
> [ 0.128001] CR2: 0000000000000010 CR3: 0000000001001000 CR4: 00000000000006b0
> [ 0.128001] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> [ 0.128001] DR3: 0000000000000000 DR6: 0000000000000000 DR7: 0000000000000000
> [ 0.128001] Process swapper (pid: 0, threadinfo ffffffff81594000, task ffffff
> ff8152a4a0)
> [ 0.128001] Stack:
> [ 0.128001] 0000000081595e68 5aa50ed3b4ddbe6e ffffffff8158f900 ffffffff8158f
> 914
> [ 0.128001] ffffffff8158f948 0000000000000000 ffffffff81595eb8 ffffffff813b8
> 69c
> [ 0.128001] 5aa50ed3b4ddbe6e 00000001078bfbfd 0000062300000800 5aa50ed3b4ddb
> e6e
> [ 0.128001] Call Trace:
> [ 0.128001] [<ffffffff813b869c>] identify_cpu+0x331/0x392
> [ 0.128001] [<ffffffff815a1445>] identify_boot_cpu+0x23/0x6e
> [ 0.128001] [<ffffffff815a14ac>] check_bugs+0x1c/0x60
> [ 0.128001] [<ffffffff8159c075>] start_kernel+0x403/0x46e
> [ 0.128001] [<ffffffff8159b2ac>] x86_64_start_reservations+0xac/0xd5
> [ 0.128001] [<ffffffff8159b3ea>] x86_64_start_kernel+0x115/0x14b
> [ 0.128001] [<ffffffff8159b140>] ? early_idt_handler+0x0/0x71

This happens on QEMU which reports MCA capability, but no banks.
Without this patch there is a buffer overrun and boot ops because
the code would try to initialize the 0 element of a zero length
kmalloc() buffer.

Reported-by: Vegard Nossum <vegard.nossum@gmail.com>
Tested-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
LKML-Reference: <20090615125200.GD31969@one.firstfloor.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
c697836985e18d9c34897428ba563b13044a6dcd 15-Jun-2009 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> x86, mce: make mce_disabled boolean

The mce_disabled on 32bit is a tristate variable [1,0,-1],
while 64bit version is boolean [0,1].
This patch makes mce_disabled always boolean, and use mce_p5_enabled
to indicate the third state instead.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
9e55e44e39798541ba39d57f4b569deb555ae1ce 15-Jun-2009 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> x86, mce: unify mce.h

There are 2 headers:
arch/x86/include/asm/mce.h
arch/x86/kernel/cpu/mcheck/mce.h
and in the latter small header:
#include <asm/mce.h>

This patch move all contents in the latter header into the former,
and fix all files using the latter to include the former instead.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
9af43b54ab4509f1dac49637d6917d57292e6518 15-Jun-2009 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> x86, mce: sysfs entries for new mce options

Add sysfs interface for admins who want to tweak these options without
rebooting the system.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
1020bcbcc7da36001d9226c5d57e999949cb80c5 15-Jun-2009 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> x86, mce: rename static variables around trigger

"trigger" is not straight forward name for valiable that holds name
of user mode helper program which triggered by machine check events.

This patch renames this valiable and kins to more recognizable names.

trigger => mce_helper
trigger_argv => mce_helper_argv
notify_user => mce_need_notify

No functional changes.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
4e5b3e690dda890523e93af9c545261f5916a3a6 15-Jun-2009 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> x86, mce: add __read_mostly

Add __read_mostly to data written during setup.

Suggested-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>
7fb06fc9672b947424e05871243a4c8e19ec3bce 15-Jun-2009 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> x86, mce: cleanup mce_start()

Simplify interface of mce_start():

- no_way_out = mce_start(no_way_out, &order);
+ order = mce_start(&no_way_out);

Now Monarch and Subjects share same exit(return) in usual path.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
33edbf02a92771fa2a81e41084a44ba874e3a5a5 15-Jun-2009 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> x86, mce: don't init timer if !mce_available

In mce_cpu_restart, mce_init_timer is called unconditionally.
If !mce_available (e.g. mce is disabled), there are no useful work
for timer. Stop running it.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
184e1fdfea066ab8f12a1e8912f402d2d6556d11 15-Jun-2009 Huang Ying <ying.huang@intel.com> x86, mce: fix a race condition about mce_callin and no_way_out

If one CPU has no_way_out == 1, all other CPUs should have no_way_out
== 1. But despite global_nwo is read after mce_callin, global_nwo is
updated after mce_callin too. So it is possible that some CPU read
global_nwo before some other CPU update global_nwo, so that no_way_out
== 1 for some CPU, while no_way_out == 0 for some other CPU.

This patch fixes this race condition via moving mce_callin updating
after global_nwo updating, with a smp_wmb in between. A smp_rmb is
added between their reading too.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
62fdac5913f71f8f200bd2c9bd59a02e9a1498e9 11-Jun-2009 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> x86, mce: Add boot options for corrected errors

This patch introduces three boot options (no_cmci, dont_log_ce
and ignore_ce) to control handling for corrected errors.

The "mce=no_cmci" boot option disables the CMCI feature.

Since CMCI is a new feature so having boot controls to disable
it will be a help if the hardware is misbehaving.

The "mce=dont_log_ce" boot option disables logging for corrected
errors. All reported corrected errors will be cleared silently.
This option will be useful if you never care about corrected
errors.

The "mce=ignore_ce" boot option disables features for corrected
errors, i.e. polling timer and cmci. All corrected events are
not cleared and kept in bank MSRs.

Usually this disablement is not recommended, however it will be
a help if there are some conflict with the BIOS or hardware
monitoring applications etc., that clears corrected events in
banks instead of OS.

[ And trivial cleanup (space -> tab) for doc is included. ]

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
LKML-Reference: <4A30ACDF.5030408@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
77e26cca20013e9352a8df86a54640543304a23a 11-Jun-2009 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> x86, mce: Fix mce printing

This patch:

- Adds print_mce_head() instead of first flag
- Makes the header to be printed always
- Stops double printing of corrected errors

[ This portion originates from Huang Ying's patch ]

Originally-From: Huang Ying <ying.huang@intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
LKML-Reference: <4A30AC83.5010708@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
9b1beaf2b551a8a1604f104025b24e9c535c8963 27-May-2009 Andi Kleen <andi@firstfloor.org> x86, mce: support action-optional machine checks

Newer Intel CPUs support a new class of machine checks called recoverable
action optional.

Action Optional means that the CPU detected some form of corruption in
the background and tells the OS about using a machine check
exception. The OS can then take appropiate action, like killing the
process with the corrupted data or logging the event properly to disk.

This is done by the new generic high level memory failure handler added
in a earlier patch. The high level handler takes the address with the
failed memory and does the appropiate action, like killing the process.

In this version of the patch the high level handler is stubbed out
with a weak function to not create a direct dependency on the hwpoison
branch.

The high level handler cannot be directly called from the machine check
exception though, because it has to run in a defined process context to
be able to sleep when taking VM locks (it is not expected to sleep for a
long time, just do so in some exceptional cases like lock contention)

Thus the MCE handler has to queue a work item for process context,
trigger process context and then call the high level handler from there.

This patch adds two path to process context: through a per thread kernel
exit notify_user() callback or through a high priority work item.
The first runs when the process exits back to user space, the other when
it goes to sleep and there is no higher priority process.

The machine check handler will schedule both, and whoever runs first
will grab the event. This is done because quick reaction to this
event is critical to avoid a potential more fatal machine check
when the corruption is consumed.

There is a simple lock less ring buffer to queue the corrupted
addresses between the exception handler and the process context handler.
Then in process context it just calls the high level VM code with
the corrupted PFNs.

The code adds the required code to extract the failed address from
the CPU's machine check registers. It doesn't try to handle all
possible cases -- the specification has 6 different ways to specify
memory address -- but only the linear address.

Most of the required checking has been already done earlier in the
mce_severity rule checking engine. Following the Intel
recommendations Action Optional errors are only enabled for known
situations (encoded in MCACODs). The errors are ignored otherwise,
because they are action optional.

v2: Improve comment, disable preemption while processing ring buffer
(reported by Ying Huang)

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>
9ff36ee9668ff41ec3274597c730524645929b0f 27-May-2009 Andi Kleen <andi@firstfloor.org> x86, mce: rename mce_notify_user to mce_notify_irq

Rename the mce_notify_user function to mce_notify_irq. The next
patch will split the wakeup handling of interrupt context
and of process context and it's better to give it a clearer
name for this.

Contains a fix from Ying Huang

[ Impact: cleanup ]

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
ed7290d0ee8f81aa78bfe816f01b012f208cafc5 27-May-2009 Andi Kleen <andi@firstfloor.org> x86, mce: implement new status bits

The x86 architecture recently added some new machine check status bits:
S(ignalled) and AR (Action-Required). Signalled allows to check
if a specific event caused an exception or was just logged through CMCI.
AR allows the kernel to decide if an event needs immediate action
or can be delayed or ignored.

Implement support for these new status bits. mce_severity() uses
the new bits to grade the machine check correctly and decide what
to do. The exception handler uses AR to decide to kill or not.
The S bit is used to separate events between the poll/CMCI handler
and the exception handler.

Classical UC always leads to panic. That was true before anyways
because the existing CPUs always passed a PCC with it.

Also corrects the rules whether to kill in user or kernel context
and how to handle missing RIPV.

The machine check handler largely uses the mce-severity grading
engine now instead of making its own decisions. This means the logic
is centralized in one place. This is useful because it has to be
evaluated multiple times.

v2: Some rule fixes; Add AO events
Fix RIPV, RIPV|EIPV order (Ying Huang)
Fix UCNA with AR=1 message (Ying Huang)
Add comment about panicing in m_c_p.

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>
86503560e48153aba539ff117450d31ab2ef76d7 27-May-2009 Andi Kleen <andi@firstfloor.org> x86, mce: print header/footer only once for multiple MCEs

When multiple MCEs are printed print the "HARDWARE ERROR" header
and "This is not a software error" footer only once. This
makes the output much more compact with many CPUs.

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>
29b0f591d678838435fbb3e15ef20266f1a9e01d 27-May-2009 Andi Kleen <andi@firstfloor.org> x86, mce: default to panic timeout for machine checks

Fatal machine checks can be logged to disk after boot, but only if
the system did a warm reboot. That's unfortunately difficult with the
default panic behaviour, which waits forever and the admin has to
press the power button because modern systems usually miss a reset button.
This clears the machine checks in the registers and make
it impossible to log them.

This patch changes the default for machine check panic to always
reboot after 30s. Then the mce can be successfully logged after
reboot.

I believe this will improve machine check experience for any
system running the X server.

This is dependent on successfull boot logging of MCEs. This currently
only works on Intel systems, on AMD there are quite a lot of systems
around which leave junk in the machine check registers after boot,
so it's disabled here. These systems will continue to default
to endless waiting panic.

v2: Only force panic timeout when it's shorter (H.Seto)
v3: Only force timeout when there is no timeout
(based on comment H.Seto)

[ Fix changelog - 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>
1b2797dcc9f0ad89bc382ace26c6baafbc7e33c2 27-May-2009 Huang Ying <ying.huang@intel.com> 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>
ac9603754dc7e286e62ae4f1067958d5b0075f99 27-May-2009 Andi Kleen <andi@firstfloor.org> 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>
3c0797925f4ef9d55a32059d2af61a9c262e639d 27-May-2009 Andi Kleen <andi@firstfloor.org> 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>
f94b61c2c9fdcc90773c49df9ccf9ede3ad0d7db 27-May-2009 Andi Kleen <andi@firstfloor.org> 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>
ccc3c3192ae78dd56dcdf5353fd1a9ef5f9a3e2b 27-May-2009 Andi Kleen <andi@firstfloor.org> 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>
bd19a5e6b73df276e1ccedf9059e9ee70c372d7d 27-May-2009 Andi Kleen <andi@firstfloor.org> 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>
a0189c70e5f17f4253dd7bc575c97469900e23d6 27-May-2009 Andi Kleen <andi@firstfloor.org> 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>
de8a84d85ad8bb46d01d72ebc57030b95075603c 27-May-2009 Andi Kleen <andi@firstfloor.org> 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>
8ee08347c1e8b5680b3b3ce081e42e97bcaa1abe 27-May-2009 Andi Kleen <andi@firstfloor.org> 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>
d620c67fb92aa11736112f9a03e31d8e3079c57a 27-May-2009 Andi Kleen <andi@firstfloor.org> 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>
f6fb0ac0869500323c78fa21992fe1933af61e91 27-May-2009 Andi Kleen <andi@firstfloor.org> 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>
ca84f69697da0f004135e45b63ca560b6bd3554e 27-May-2009 Andi Kleen <andi@firstfloor.org> 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>
01ca79f1411eae2a45352709c838b946b1af9fbd 27-May-2009 Andi Kleen <andi@firstfloor.org> 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>
14a02530e2239f753a0f3f089847e723adbdaa47 30-Apr-2009 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> 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>
9319cec8c185e84fc5281afb6ac5d4c47a234841 14-Apr-2009 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> 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>
b170204ddb7844ffff62d2d537b20c0eeb97725e 27-May-2009 Andi Kleen <andi@firstfloor.org> 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>
32561696c23028596f24b353d98f2e23b58f91f7 27-May-2009 Andi Kleen <andi@firstfloor.org> 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>
8be9110569aec1f65d86b08aef7ec49659137bf9 27-May-2009 Thomas Gleixner <tglx@linutronix.de> 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>
fc016a49c2d92f2efbe22c1fb66eb7a5d2a06ed1 27-May-2009 Andi Kleen <andi@firstfloor.org> 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>
b56f642d2bf8c1f7c6499c1e55b23311a33cc796 27-May-2009 Andi Kleen <andi@firstfloor.org> 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>
88921be30296e126896ee4d30758f989d1c4ddfb 27-May-2009 Andi Kleen <andi@firstfloor.org> 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>
a1ff41bfc1bb7a6d19cf958f89a9b539678781e5 26-May-2009 H. Peter Anvin <hpa@zytor.com> 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>
ea149b36c7f511d17dd89fee734cb09778a91fa0 29-Apr-2009 Andi Kleen <ak@linux.intel.com> 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>
5f8c1a54cab6f449fe04d42d0661bc796fa4e73e 29-Apr-2009 Andi Kleen <ak@linux.intel.com> 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>
4efc0670baf4b14bc95502e54a83ccf639146125 28-Apr-2009 Andi Kleen <ak@linux.intel.com> 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>
d896a940ef4f12a0a6bc432853b249dcfbacabf0 28-Apr-2009 Andi Kleen <ak@linux.intel.com> 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>
8e97aef5f43ec715f394bc15015ff263b80c3ad6 28-Apr-2009 Andi Kleen <ak@linux.intel.com> 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>
d7c3c9a609563868d8a70e220399d06a25aba095 28-Apr-2009 Andi Kleen <ak@linux.intel.com> 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>
04b2b1a4df6cd0fdaa598f3c623a19c2d93cb48a 28-Apr-2009 Andi Kleen <ak@linux.intel.com> 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>
5d7279268b654d1f8ac43b0eb6cd9598d9cf55fd 27-Apr-2009 Andi Kleen <ak@linux.intel.com> 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>
2e6f694fde0a7158590e121962ca2e3c06633528 27-Apr-2009 Andi Kleen <ak@linux.intel.com> 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>
06b7a7a5ec917761969444fee967c43868a76468 27-Apr-2009 Andi Kleen <ak@linux.intel.com> 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>
3cde5c8c839bf46a7be799ed0e1d0b4780aaf794 27-Apr-2009 Andi Kleen <ak@linux.intel.com> 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>
01c6680a547a3ee8dd170c269ea8e037b3191b71 08-Apr-2009 Thomas Gleixner <tglx@linutronix.de> 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>
b659294b779565c60f5e12ef505328e2b974eb62 08-Apr-2009 Ingo Molnar <mingo@elte.hu> x86, mce: print number of MCE banks

The number of MCE banks supported by a CPU is a useful number to know,
so print it out during CPU initialization.

[ Impact: add printout ]

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>
cb491fca55e5282f0a95ef39c55352e00d6ca75e 08-Apr-2009 Ingo Molnar <mingo@elte.hu> x86, mce: Rename sysfs variables

Shorten variable names. This also compacts the code a bit.

device_mce => mce_dev
mce_device_initialized => mce_dev_initialized
mce_attribute => mce_attrs

[ Impact: cleanup ]

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>
dba3725d44f5dfb5711fd509fca10b5b828c43b7 08-Apr-2009 Ingo Molnar <mingo@elte.hu> x86, mce: unify

move mce_64.c => mce.c and glue it up in the Makefile.
Remove mce_32.c

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>
3bc258ad87e5b0bbbca247b24ce8fac380c7d86b 23-Oct-2007 Thomas Gleixner <tglxlinutronix.de> x86: prepare consolidation of cpu/ related code usage

Move mce.c to mce_32.c to allow the later move of the x86_64 mce.c
from arch/x86/kernel/ to ...kernel/cpu/mcheck

No code change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
c18db0d7e299791c73d4dbe5ae7905b2ab8ba332 11-Oct-2007 Thomas Gleixner <tglx@linutronix.de> i386: move kernel/cpu/mcheck

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>