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: NBorislav Petkov <bp@suse.de>
Tested-by: NPrarit Bhargava <prarit@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>
Reviewed-by: NChen, Gong <gong.chen@linux.intel.com>
Link: http://lkml.kernel.org/r/1387722156-5511-1-git-send-email-prarit@redhat.com

None of these files are actually using any __init type directives
and hence don't need to include <linux/init.h>.  Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.

[ hpa: undid incorrect removal from arch/x86/kernel/head_32.S ]
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Link: http://lkml.kernel.org/r/1389054026-12947-1-git-send-email-paul.gortmaker@windriver.comSigned-off-by: NH. Peter Anvin <hpa@zytor.com>

Currently SCI is employed to handle corrected errors - memory corrected
errors, more specifically but in fact SCI still can be used to handle
any errors, e.g. uncorrected or even fatal ones if enabled by the BIOS.
Enable logging for those kinds of errors too.
Signed-off-by: NChen, Gong <gong.chen@linux.intel.com>
Acked-by: NNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/1385363701-12387-1-git-send-email-gong.chen@linux.intel.com
[ Boris: massage commit message, rename function arg. ]
Signed-off-by: NBorislav Petkov <bp@suse.de>

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: NLevente Kurusa <levex@linux.com>
Link: http://lkml.kernel.org/r/5298F900.9000208@linux.comSigned-off-by: NBorislav Petkov <bp@suse.de>

In latest UEFI spec(by now it is 2.4) memory error definition
for CPER (UEFI 2.4 Appendix N Common Platform Error Record)
adds some new fields. These fields help people to locate
memory error to an actual DIMM location.

Original-author: Tony Luck <tony.luck@intel.com>
Signed-off-by: NChen, Gong <gong.chen@linux.intel.com>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NMauro Carvalho Chehab <m.chehab@samsung.com>
Acked-by: NNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

In commit 33d7885b
   x86/mce: Update MCE severity condition check

We simplified the rules to recognise each classification of recoverable
machine check combining the instruction and data fetch rules into a
single entry based on clarifications in the June 2013 SDM that all
recoverable events would be reported on the unaffected processor with
MCG_STATUS.EIPV=0 and MCG_STATUS.RIPV=1.  Unfortunately the simplified
rule has a couple of bugs.  Fix them here.
Acked-by: NNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

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 5e427ec2 ("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: NIngo Molnar <mingo@kernel.org>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NH. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

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: NNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Update some SRAR severity conditions check to make it clearer,
according to latest Intel SDM Vol 3(June 2013), table 15-20.
Signed-off-by: NChen Gong <gong.chen@linux.intel.com>
Acked-by: NNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

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: NNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NTony Luck <tony.luck@intel.com>

[Purpose of this patch]

As Vaibhav explained in the thread below, tracepoints for irq vectors
are useful.

http://www.spinics.net/lists/mm-commits/msg85707.html

<snip>
The current interrupt traces from irq_handler_entry and irq_handler_exit
provide when an interrupt is handled.  They provide good data about when
the system has switched to kernel space and how it affects the currently
running processes.

There are some IRQ vectors which trigger the system into kernel space,
which are not handled in generic IRQ handlers.  Tracing such events gives
us the information about IRQ interaction with other system events.

The trace also tells where the system is spending its time.  We want to
know which cores are handling interrupts and how they are affecting other
processes in the system.  Also, the trace provides information about when
the cores are idle and which interrupts are changing that state.
<snip>

On the other hand, my usecase is tracing just local timer event and
getting a value of instruction pointer.

I suggested to add an argument local timer event to get instruction pointer before.
But there is another way to get it with external module like systemtap.
So, I don't need to add any argument to irq vector tracepoints now.

[Patch Description]

Vaibhav's patch shared a trace point ,irq_vector_entry/irq_vector_exit, in all events.
But there is an above use case to trace specific irq_vector rather than tracing all events.
In this case, we are concerned about overhead due to unwanted events.

So, add following tracepoints instead of introducing irq_vector_entry/exit.
so that we can enable them independently.
   - local_timer_vector
   - reschedule_vector
   - call_function_vector
   - call_function_single_vector
   - irq_work_entry_vector
   - error_apic_vector
   - thermal_apic_vector
   - threshold_apic_vector
   - spurious_apic_vector
   - x86_platform_ipi_vector

Also, introduce a logic switching IDT at enabling/disabling time so that a time penalty
makes a zero when tracepoints are disabled. Detailed explanations are as follows.
 - Create trace irq handlers with entering_irq()/exiting_irq().
 - Create a new IDT, trace_idt_table, at boot time by adding a logic to
   _set_gate(). It is just a copy of original idt table.
 - Register the new handlers for tracpoints to the new IDT by introducing
   macros to alloc_intr_gate() called at registering time of irq_vector handlers.
 - Add checking, whether irq vector tracing is on/off, into load_current_idt().
   This has to be done below debug checking for these reasons.
   - Switching to debug IDT may be kicked while tracing is enabled.
   - On the other hands, switching to trace IDT is kicked only when debugging
     is disabled.

In addition, the new IDT is created only when CONFIG_TRACING is enabled to avoid being
used for other purposes.
Signed-off-by: NSeiji Aguchi <seiji.aguchi@hds.com>
Link: http://lkml.kernel.org/r/51C323ED.5050708@hds.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>

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

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

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

A way to use them is as follows.

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

}

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

}

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

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

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

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

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

But it doesn't work, either.
If irq_enter() is nested, it may have a time penalty because it has to check if it
was already called or not. The time penalty is not desired in performance sensitive
paths even if it is tiny.
Signed-off-by: NSeiji Aguchi <seiji.aguchi@hds.com>
Link: http://lkml.kernel.org/r/51C3238D.9040706@hds.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>

The package power limit notification interrupt is primarily for
system diagnosis, and should not be blindly enabled on every
system by default -- particuarly since Linux does nothing in the
handler except count how many times it has been called...

Add a new kernel cmdline parameter "int_pln_enable" for situations where
users want to oberve these events via existing system counters:

$ grep TRM /proc/interrupts

$ grep . /sys/devices/system/cpu/cpu*/thermal_throttle/*

https://bugzilla.kernel.org/show_bug.cgi?id=36182Signed-off-by: NFenghua Yu <fenghua.yu@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Package power limits are common on some systems under some conditions --
so printing console messages when limits are reached
causes unnecessary customer concern and support calls.

Note that even with these console messages gone,
the events can still be observed via system counters:

$ grep TRM /proc/interrupts

Shows total thermal interrupts, which includes both power
limit notifications and thermal throttling interrupts.

$ grep . /sys/devices/system/cpu/cpu*/thermal_throttle/*

Will show what caused those interrupts, core and package
throttling and power limit notifications.

https://bugzilla.kernel.org/show_bug.cgi?id=36182Signed-off-by: NFenghua Yu <fenghua.yu@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Added callback registration for package threshold reports. Also added
a callback to check the rate control implemented in callback or not.
If there is no rate control implemented, then there is a default rate
control similar to core threshold notification by delaying for
CHECK_INTERVAL (5 minutes) between reports.
Signed-off-by: NSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: NZhang Rui <rui.zhang@intel.com>

Fix the typo in MCJ_IRQ_BRAODCAST.
Signed-off-by: NMathias Krause <minipli@googlemail.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>

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: NDave Jones <davej@redhat.com>
Signed-off-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Currently number of error reporting register banks is hardcoded to
6 on AMD processors. This may break in virtualized scenarios when
a hypervisor prefers to report fewer banks than what the physical
HW provides.

Since number of supported banks is reported in MSR_IA32_MCG_CAP[7:0]
that's what we should use.
Signed-off-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Link: http://lkml.kernel.org/r/1363295441-1859-3-git-send-email-boris.ostrovsky@oracle.com
[ reverse NULL ptr test logic ]
Signed-off-by: NBorislav Petkov <bp@suse.de>

Use helper function instead of an array to report whether register
bank is shared. Currently only bank 4 (northbridge) is shared.
Signed-off-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Link: http://lkml.kernel.org/r/1363295441-1859-2-git-send-email-boris.ostrovsky@oracle.comSigned-off-by: NBorislav Petkov <bp@suse.de>

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: NRusty Russell <rusty@rustcorp.com.au>

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: NTejun Heo <tj@kernel.org>
Acked-by: NBorislav Petkov <bp@alien8.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-edac@vger.kernel.org

cmci_rediscover() used set_cpus_allowed_ptr() to change the current process's
running cpu, and migrate itself to the dest cpu. But worker processes are not
allowed to be migrated. If current is a worker, the worker will be migrated to
another cpu, but the corresponding  worker_pool is still on the original cpu.

In this case, the following BUG_ON in try_to_wake_up_local() will be triggered:
BUG_ON(rq != this_rq());

This will cause the kernel panic. The call trace is like the following:

[ 6155.451107] ------------[ cut here ]------------
[ 6155.452019] kernel BUG at kernel/sched/core.c:1654!
......
[ 6155.452019] RIP: 0010:[<ffffffff810add15>]  [<ffffffff810add15>] try_to_wake_up_local+0x115/0x130
......
[ 6155.452019] Call Trace:
[ 6155.452019]  [<ffffffff8166fc14>] __schedule+0x764/0x880
[ 6155.452019]  [<ffffffff81670059>] schedule+0x29/0x70
[ 6155.452019]  [<ffffffff8166de65>] schedule_timeout+0x235/0x2d0
[ 6155.452019]  [<ffffffff810db57d>] ? mark_held_locks+0x8d/0x140
[ 6155.452019]  [<ffffffff810dd463>] ? __lock_release+0x133/0x1a0
[ 6155.452019]  [<ffffffff81671c50>] ? _raw_spin_unlock_irq+0x30/0x50
[ 6155.452019]  [<ffffffff810db8f5>] ? trace_hardirqs_on_caller+0x105/0x190
[ 6155.452019]  [<ffffffff8166fefb>] wait_for_common+0x12b/0x180
[ 6155.452019]  [<ffffffff810b0b30>] ? try_to_wake_up+0x2f0/0x2f0
[ 6155.452019]  [<ffffffff8167002d>] wait_for_completion+0x1d/0x20
[ 6155.452019]  [<ffffffff8110008a>] stop_one_cpu+0x8a/0xc0
[ 6155.452019]  [<ffffffff810abd40>] ? __migrate_task+0x1a0/0x1a0
[ 6155.452019]  [<ffffffff810a6ab8>] ? complete+0x28/0x60
[ 6155.452019]  [<ffffffff810b0fd8>] set_cpus_allowed_ptr+0x128/0x130
[ 6155.452019]  [<ffffffff81036785>] cmci_rediscover+0xf5/0x140
[ 6155.452019]  [<ffffffff816643c0>] mce_cpu_callback+0x18d/0x19d
[ 6155.452019]  [<ffffffff81676187>] notifier_call_chain+0x67/0x150
[ 6155.452019]  [<ffffffff810a03de>] __raw_notifier_call_chain+0xe/0x10
[ 6155.452019]  [<ffffffff81070470>] __cpu_notify+0x20/0x40
[ 6155.452019]  [<ffffffff810704a5>] cpu_notify_nofail+0x15/0x30
[ 6155.452019]  [<ffffffff81655182>] _cpu_down+0x262/0x2e0
[ 6155.452019]  [<ffffffff81655236>] cpu_down+0x36/0x50
[ 6155.452019]  [<ffffffff813d3eaa>] acpi_processor_remove+0x50/0x11e
[ 6155.452019]  [<ffffffff813a6978>] acpi_device_remove+0x90/0xb2
[ 6155.452019]  [<ffffffff8143cbec>] __device_release_driver+0x7c/0xf0
[ 6155.452019]  [<ffffffff8143cd6f>] device_release_driver+0x2f/0x50
[ 6155.452019]  [<ffffffff813a7870>] acpi_bus_remove+0x32/0x6d
[ 6155.452019]  [<ffffffff813a7932>] acpi_bus_trim+0x87/0xee
[ 6155.452019]  [<ffffffff813a7a21>] acpi_bus_hot_remove_device+0x88/0x16b
[ 6155.452019]  [<ffffffff813a33ee>] acpi_os_execute_deferred+0x27/0x34
[ 6155.452019]  [<ffffffff81090589>] process_one_work+0x219/0x680
[ 6155.452019]  [<ffffffff81090528>] ? process_one_work+0x1b8/0x680
[ 6155.452019]  [<ffffffff813a33c7>] ? acpi_os_wait_events_complete+0x23/0x23
[ 6155.452019]  [<ffffffff810923be>] worker_thread+0x12e/0x320
[ 6155.452019]  [<ffffffff81092290>] ? manage_workers+0x110/0x110
[ 6155.452019]  [<ffffffff81098396>] kthread+0xc6/0xd0
[ 6155.452019]  [<ffffffff8167c4c4>] kernel_thread_helper+0x4/0x10
[ 6155.452019]  [<ffffffff81671f30>] ? retint_restore_args+0x13/0x13
[ 6155.452019]  [<ffffffff810982d0>] ? __init_kthread_worker+0x70/0x70
[ 6155.452019]  [<ffffffff8167c4c0>] ? gs_change+0x13/0x13

This patch removes the set_cpus_allowed_ptr() call, and put the cmci rediscover
jobs onto all the other cpus using system_wq. This could bring some delay for
the jobs.
Signed-off-by: NTang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Move to private email and put in maintained status.
Signed-off-by: NBorislav Petkov <bp@alien8.de>
Link: http://lkml.kernel.org/r/1351532410-4887-1-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

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: NBorislav Petkov <bp@alien8.de>
Acked-by: NTony Luck <tony.luck@intel.com>

Move them into the mca_config struct and adjust code touching them
accordingly.
Signed-off-by: NBorislav Petkov <bp@alien8.de>
Acked-by: NTony Luck <tony.luck@intel.com>

Move above configuration variables into struct mca_config and adjust
usage places accordingly.
Signed-off-by: NBorislav Petkov <bp@alien8.de>
Acked-by: NTony Luck <tony.luck@intel.com>

Move those MCA configuration variables into struct mca_config and adjust
the places they're used accordingly.
Signed-off-by: NBorislav Petkov <bp@alien8.de>
Acked-by: NTony Luck <tony.luck@intel.com>

450cc201 ("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: NTony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/20121017105940.GA14590@x1.osrc.amd.comSigned-off-by: NBorislav Petkov <borislav.petkov@amd.com>

When booting on a federated multi-server system (NumaScale), the
processor Northbridge lookup returns NULL; add guards to prevent this
causing an oops.

On those systems, the northbridge is accessed through MMIO and the
"normal" northbridge enumeration in amd_nb.c doesn't work since we're
generating the northbridge ID from the initial APIC ID and the last
is not unique on those systems. Long story short, we end up without
northbridge descriptors.
Signed-off-by: NDaniel J Blueman <daniel@numascale-asia.com>
Cc: stable@vger.kernel.org # 3.6
Link: http://lkml.kernel.org/r/1349073725-14093-1-git-send-email-daniel@numascale-asia.com
[ Boris: beef up commit message ]
Signed-off-by: NBorislav Petkov <borislav.petkov@amd.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

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: NNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

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: NChen Gong <gong.chen@linux.intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Tested-by: NChen Gong <gong.chen@linux.intel.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

cmci_discover() works out which machine check banks support CMCI, and
which of those are shared by multiple logical processors. It uses this
information to ensure that exactly one cpu is designated the owner of
each bank so that when interrupts are broadcast to multiple cpus, only one
of them will look in a shared bank to log the error and clear the bank.

At boot time cmci_discover() performs this task silently. But during
certain cpu hotplug operations it prints out a set of summary lines
like this:

CPU 35 MCA banks CMCI:0 CMCI:1 CMCI:3 CMCI:5 CMCI:6 CMCI:7 CMCI:8 CMCI:9 CMCI:10 CMCI:11
CPU 1 MCA banks CMCI:0 CMCI:1 CMCI:3
CPU 39 MCA banks CMCI:0 CMCI:1 CMCI:3
CPU 38 MCA banks CMCI:0 CMCI:1 CMCI:3
CPU 32 MCA banks CMCI:0 CMCI:1 CMCI:3
CPU 37 MCA banks CMCI:0 CMCI:1 CMCI:3
CPU 36 MCA banks CMCI:0 CMCI:1 CMCI:3
CPU 34 MCA banks CMCI:0 CMCI:1 CMCI:3

The value of these messages seems very low. A user might painstakingly
cross-check against the data sheet for a processor to ensure that all
CMCI supported banks are correctly reported, but this seems improbable.
If users really wanted to do this, we should print the information at
boot time too.

Remove the messages.
Signed-off-by: NTony Luck <tony.luck@intel.com>

No point in having double cases if we can simply mask the FROZEN bit
out.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NChen Gong <gong.chen@linux.intel.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

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: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NChen Gong <gong.chen@linux.intel.com>
Acked-by: NBorislav Petkov <borislav.petkov@amd.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

raise_mce() fiddles with global state, but lacks any kind of
serialization.

Add a mutex around the raise_mce() call, so concurrent writers do not
stomp on each other toes.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NChen Gong <gong.chen@linux.intel.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

raise_mce() has a code path which does not disable preemption when the
raise_local() is called. The per cpu variable access in raise_local()
depends on preemption being disabled to be functional. So that code
path was either never tested or never tested with CONFIG_DEBUG_PREEMPT
enabled.

Add the missing preempt_disable/enable() pair around the call.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NChen Gong <gong.chen@linux.intel.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

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: NBorislav Petkov <bp@amd64.org>
Signed-off-by: NTony 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.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

We will need some of these values in mce.c. Move them to the
appropriate header file so they are available.
Acked-by: NBorislav Petkov <bp@amd64.org>
Signed-off-by: NTony 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/0ccfb1af5fe35e537b7cd8e4d448bf7d851dbfb9.1343078495.git.tony.luck@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

there are 3 funcs which need to be _initcalled in a logic sequence:
1. xen_late_init_mcelog
2. mcheck_init_device
3. threshold_init_device

xen_late_init_mcelog must register xen_mce_chrdev_device before
native mce_chrdev_device registration if running under xen platform;

mcheck_init_device should be inited before threshold_init_device to
initialize mce_device, otherwise a a NULL ptr dereference will cause panic.

so we use following _initcalls
1. device_initcall(xen_late_init_mcelog);
2. device_initcall_sync(mcheck_init_device);
3. late_initcall(threshold_init_device);

when running under xen, the initcall order is 1,2,3;
on baremetal, we skip 1 and we do only 2 and 3.
Acked-and-tested-by: NBorislav Petkov <bp@amd64.org>
Suggested-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NLiu, Jinsong <jinsong.liu@intel.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

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: NBorislav Petkov <borislav.petkov@amd.com>
Signed-off-by: NKe, Liping <liping.ke@intel.com>
Signed-off-by: NJiang, Yunhong <yunhong.jiang@intel.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NLiu, Jinsong <jinsong.liu@intel.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>