The 'error record serialization table' in ACPI provides a suitable
amount of persistent storage for use by the pstore filesystem.
Signed-off-by: NTony Luck <tony.luck@intel.com>

ERST writing may be used in NMI or Machine Check Exception handler. So
it need to use raw spinlock instead of normal spinlock.  This patch
fixes it.
Signed-off-by: NHuang Ying <ying.huang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

The src_base and dst_base fields in apei_exec_context are physical
address, so they should be ioremaped before being used in ERST
MOVE_DATA instruction.
Reported-by: NJavier Martinez Canillas <martinez.javier@gmail.com>
Reported-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NHuang Ying <ying.huang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

On Huang Ying's machine:

erst_tab->header_length == sizeof(struct acpi_table_einj)

but Yinghai reported that on his machine,

erst_tab->header_length == sizeof(struct acpi_table_einj) -
sizeof(struct acpi_table_header)

To make erst table size checking code works on all systems, both
testing are treated as PASS.

Same situation applies to einj_tab->header_length, so corresponding
table size checking is changed in similar way too.

v2:

- Treat both table size as valid
Originally-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NHuang Ying <ying.huang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Signed-off-by: NLen Brown <len.brown@intel.com>

The ACPI_PREEMPTION_POINT() logic was introduced in commit 8bd108d1
(ACPICA: add preemption point after each opcode parse).  The follow up
commits abe1dfab, 138d1569, c084ca70 tried to fix the preemption logic
back and forth, but nobody noticed that the usage of
in_atomic_preempt_off() in that context is wrong.

The check which guards the call of cond_resched() is:

    if (!in_atomic_preempt_off() && !irqs_disabled())

in_atomic_preempt_off() is not intended for general use as the comment
above the macro definition clearly says:

 * Check whether we were atomic before we did preempt_disable():
 * (used by the scheduler, *after* releasing the kernel lock)

On a CONFIG_PREEMPT=n kernel the usage of in_atomic_preempt_off() works by
accident, but with CONFIG_PREEMPT=y it's just broken.

The whole purpose of the ACPI_PREEMPTION_POINT() is to reduce the latency
on a CONFIG_PREEMPT=n kernel, so make ACPI_PREEMPTION_POINT() depend on
CONFIG_PREEMPT=n and remove the in_atomic_preempt_off() check.

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=16210

[akpm@linux-foundation.org: fix build]
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Len Brown <lenb@kernel.org>
Cc: Francois Valenduc <francois.valenduc@tvcablenet.be>
Cc: Lin Ming <ming.m.lin@intel.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When booting 2.6.35-rc3 on a x86 system without an ERST ACPI table with
the 'quiet' option, we still observe an "ERST: Table is not found!"
warning.

Quiesce it to the same info log level as the other 'table not found'
warnings.
Signed-off-by: NDaniel J Blueman <daniel.blueman@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

ERST is a way provided by APEI to save and retrieve hardware error
record to and from some simple persistent storage (such as flash).

The Linux kernel support implementation is quite simple and workable
in NMI context. So it can be used to save hardware error record into
flash in hardware error exception or NMI handler, where other more
complex persistent storage such as disk is not usable. After saving
hardware error records via ERST in hardware error exception or NMI
handler, the error records can be retrieved and logged into disk or
network after a clean reboot.

For more information about ERST, please refer to ACPI Specification
version 4.0, section 17.4.

This patch incorporate fixes from Jin Dongming.
Signed-off-by: NHuang Ying <ying.huang@intel.com>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
CC: Jin Dongming <jin.dongming@np.css.fujitsu.com>
Signed-off-by: NLen Brown <len.brown@intel.com>