Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC: r227309 (partial)

Mark all SYSCTL_NODEs static that have no corresponding SYSCTL_DECLs.

The SYSCTL_NODE macro defines a list that stores all child-elements of
that node. If there's no SYSCTL_DECL macro anywhere else, there's no
reason why it shouldn't be static.

MFC 233709,233781,233793:
- Don't malloc() new MCA records for machine checks logged due to a
CMCI or MC# exception. Instead, use a pre-allocated pool of records.
When a CMCI or MC# exception fires, schedule a task to refill the pool.
The pool is sized to hold at least one record per available machine
bank, and one record per CPU. This should handle the case of all CPUs
triggering a single bank at once as well as the case a single CPU
triggering all of its banks. The periodic scans still use malloc()
since they are run from a safe context.
- Make machine check exception logging more readable. On newer Intel systems,
an uncorrected ECC error tends to fire on all CPUs in a package
simultaneously and the current printf hacks are not sufficient to make
the messages legible. Instead, use the existing mca_lock spinlock to
serialize calls to mca_log() and change the machine check code to panic
directly when an unrecoverable error is encoutered rather than falling
back to a trap_fatal() call in trap() (which adds nearly a screen-full of
logging messages that aren't useful for machine checks).

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Use a dedicated taskqueue with a thread that runs at a software-interrupt
priority for the periodic polling of the machine check registers.

Move the <machine/mca.h> header to <x86/mca.h>.

The corrected error count field is dependent on CMCI, not TES.

MFC after: 1 week

Restore the machine check register banks on resume. For banks being
monitored via CMCI, reset the interrupt threshold to 1 on resume.

Reviewed by: jkim
MFC after: 2 weeks

Update several places that iterate over CPUs to use CPU_FOREACH().

Move the machine check support code to the x86 tree since it is identical
on i386 and amd64.

Requested by: alc

Defer initializing machine checks for the boot CPU until the local APIC is
fully configured.

MFC after: 1 month

Only enable CMCI on i386 if 'device apic' is enabled in the kernel since
it requires the local APIC to work.

Add support for corrected machine check interrupts. CMCI is a new local
APIC interrupt that fires when a threshold of corrected machine check
events is reached. CMCI also includes a count of events when reporting
corrected errors in the bank's status register. Note that individual
banks may or may not support CMCI. If they do, each bank includes its own
threshold register that determines when the interrupt fires. Currently
the code uses a very simple strategy where it doubles the threshold on
each interrupt until it succeeds in throttling the interrupt to occur
only once a minute (this interval can be tuned via sysctl). The threshold
is also adjusted on each hourly poll which will lower the threshold once
events stop occurring.

Tested by: Sailaja Bangaru sbappana at yahoo com
MFC after: 1 month

Adapt r204907 and r205402, the amd64 implementation of the workaround for
AMD Family 10h Erratum 383, to i386.

Enable machine check exceptions by default, just like r204913 for amd64.

Enable superpage promotion only if the processor actually supports large
pages, i.e., PG_PS.

MFC after: 2 weeks

- Extend the machine check record structure to include several fields useful
for parsing model-specific and other fields in machine check events
including the global machine check capabilities and status registers,
CPU identification, and the FreeBSD CPU ID.
- Report these added fields in the console log of a machine check so that
a record structure can be reconstituted from the console messages.
- Parse new architectural errors including memory controller errors.

MFC after: 1 week

Print the contents of the miscellaneous (MISC) register to the console if
it is valid along with the other register values when a machine check is
encountered.

MFC after: 1 week

mca: small enhancements related to cpu quirks

- use utility macros for CPU family/model checking
- limit Intel P6 quirk to pre-Nehalem models (taken from OpenSolaris)
- add AMD GartTblWkEn quirk for families 0Fh and 10h; I haven't experienced
any problems without the quirk but both Linux and OpenSolaris do this
- slightly re-arrange quirk code to provide for the future generalization
and separation of vendor-specific quirk functions

Reviewed by: jhb
MFC after: 1 week

mca: improve status checking, recording and reporting

- directly print mca information in case we fail to allocate memory
for a record
- include bank number into mca record
- print raw mca status value for extended information

Reviewed by: jhb
MFC after: 10 days

Don't bother reading the initial value of the machine check banks during
startup on Pentium 4 CPUs. This wasn't safe to do on APs during AP startup,
was of limited value, and won't be used for future processors.

- Add a tunable 'hw.mca.enabled' that can be used to enable/disable the
machine check code. Disable it by default for now.
- When computing the mask of bits that determines a non-restartable event
during a machine check exception, or-in the overflow flag rather than
replacing the other flags.

PR: i386/134586 [2]
Submitted by: Andi Kleen andi-fbsd firstfloor.org

Implement simple machine check support for amd64 and i386.
- For CPUs that only support MCE (the machine check exception) but not MCA
(i.e. Pentium), all this does is print out the value of the machine check
registers and then panic when a machine check exception occurs.
- For CPUs that support MCA (the machine check architecture), the support is
a bit more involved.
- First, there is limited support for decoding the CPU-independent MCA
error codes in the kernel, and the kernel uses this to output a short
description of any machine check events that occur.
- When a machine check exception occurs, all of the MCx banks on the
current CPU are scanned and any events are reported to the console
before panic'ing.
- To catch events for correctable errors, a periodic timer kicks off a
task which scans the MCx banks on all CPUs. The frequency of these
checks is controlled via the "hw.mca.interval" sysctl.
- Userland can request an immediate scan of the MCx banks by writing
a non-zero value to "hw.mca.force_scan".
- If any correctable events are encountered, the appropriate details
are stored in a 'struct mca_record' (defined in <machine/mca.h>).
The "hw.mca.count" is a count of such records and each record may
be queried via the "hw.mca.records" tree by specifying the record
index (0 .. count - 1) as the next name in the MIB similar to using
PIDs with the kern.proc.* sysctls. The idea is to export machine
check events to userland for more detailed processing.
- The periodic timer and hw.mca sysctls are only present if the CPU
supports MCA.

Discussed with: emaste (briefly)
MFC after: 1 month