Hi Borislav,
On 19 January 2016 at 18:12, Borislav Petkov bp@alien8.de wrote:
On Tue, Jan 19, 2016 at 05:34:02PM +0800, fu.wei@linaro.org wrote:
From: Huang Ying ying.huang@intel.com
ACPI/APEI is designed to verifiy/report H/W errors, like Corrected Error(CE) and Uncorrected Error(UC). It contains four tables: HEST, ERST, EINJ and BERT. The first three tables have been merged for a long time, but because of lacking BIOS support for BERT, the support for BERT is pending until now. Recently on ARM 64 platform it is has been supported. So here we come.
Under normal circumstances, when a hardware error occurs, kernel will be notified via NMI, MCE or some other method, then kernel will process the error condition, report it, and recover it if possible. But sometime, the situation is so bad, so that firmware may choose to reset directly without notifying Linux kernel.
Linux kernel can use the Boot Error Record Table (BERT) to get the un-notified hardware errors that occurred in a previous boot. In this patch, the error information is reported via printk.
For more information about BERT, please refer to ACPI Specification version 6.0, section 18.3.1: http://www.uefi.org/sites/default/files/resources/ACPI_6.0.pdf
The following log is a BERT record after system reboot because of hitting a fatal memory error: BERT: Error records from previous boot: [Hardware Error]: It has been corrected by h/w and requires no further action [Hardware Error]: event severity: corrected [Hardware Error]: Error 0, type: recoverable [Hardware Error]: section_type: memory error [Hardware Error]: error_status: 0x0000000000000400 [Hardware Error]: physical_address: 0xffffffffffffffff [Hardware Error]: card: 1 module: 2 bank: 3 row: 1 column: 2 bit_position: 5 [Hardware Error]: error_type: 2, single-bit ECC
[Tomasz Nowicki: Clear error status at the end of error handling] [Tony: Applied some cleanups suggested by Fu Wei] [Fu Wei: delete EXPORT_SYMBOL_GPL(bert_disable), improve the code]
Signed-off-by: Huang Ying ying.huang@intel.com Signed-off-by: Tomasz Nowicki tomasz.nowicki@linaro.org Signed-off-by: Chen, Gong gong.chen@linux.intel.com Tested-by: Jonathan (Zhixiong) Zhang zjzhang@codeaurora.org Signed-off-by: Tony Luck tony.luck@intel.com Signed-off-by: Fu Wei fu.wei@linaro.org Tested-by: Tyler Baicar tbaicar@codeaurora.org
Changelog: v5: Drop some superfluous comments. Use the introduce of BERT in ACPI Specification instead of original one at the head of bert.c. Fix typo in apei-internal.h Simplify the introduce of bert_disable.
v4: https://lkml.org/lkml/2016/1/8/382 Fix the "#undef" bug Improve the instruction of "bert_disable", Delete the useless declaration in include/acpi/apei.h.
v3: https://lkml.org/lkml/2016/1/7/214 Merge the two patches Do some improvements according to Borislav's suggestion.
v2: https://lkml.org/lkml/2015/8/18/336 Delete EXPORT_SYMBOL_GPL(bert_disable), because "bert_disable" is only used in bert.c for now. Do some code-style cleanups.
v1: The first upstream version submitted in linux-acpi mailing list: http://www.spinics.net/lists/linux-acpi/msg57384.html
Documentation/kernel-parameters.txt | 3 + drivers/acpi/apei/Makefile | 2 +- drivers/acpi/apei/apei-internal.h | 2 +- drivers/acpi/apei/bert.c | 150 ++++++++++++++++++++++++++++++++++++ 4 files changed, 155 insertions(+), 2 deletions(-)
Reviewed-by: Borislav Petkov bp@suse.de
Great thanks for your help :-)
-- Regards/Gruss, Boris.
ECO tip #101: Trim your mails when you reply.