Hi Borislav, On 19 January 2016 at 17:34, <fu.wei@xxxxxxxxxx> wrote: > From: Huang Ying <ying.huang@xxxxxxxxx> > > 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@xxxxxxxxx> > Signed-off-by: Tomasz Nowicki <tomasz.nowicki@xxxxxxxxxx> > Signed-off-by: Chen, Gong <gong.chen@xxxxxxxxxxxxxxx> > Tested-by: Jonathan (Zhixiong) Zhang <zjzhang@xxxxxxxxxxxxxx> > Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx> > Signed-off-by: Fu Wei <fu.wei@xxxxxxxxxx> > Tested-by: Tyler Baicar <tbaicar@xxxxxxxxxxxxxx> > --- > 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(-) > > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt > index 3ea869d..acb772e 100644 > --- a/Documentation/kernel-parameters.txt > +++ b/Documentation/kernel-parameters.txt > @@ -564,6 +564,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. > > bootmem_debug [KNL] Enable bootmem allocator debug messages. > > + bert_disable [ACPI] > + Disable BERT OS support on buggy BIOSes. > + > bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards) > bttv.radio= Most important insmod options are available as > kernel args too. > diff --git a/drivers/acpi/apei/Makefile b/drivers/acpi/apei/Makefile > index 5d575a9..e50573d 100644 > --- a/drivers/acpi/apei/Makefile > +++ b/drivers/acpi/apei/Makefile > @@ -3,4 +3,4 @@ obj-$(CONFIG_ACPI_APEI_GHES) += ghes.o > obj-$(CONFIG_ACPI_APEI_EINJ) += einj.o > obj-$(CONFIG_ACPI_APEI_ERST_DEBUG) += erst-dbg.o > > -apei-y := apei-base.o hest.o erst.o > +apei-y := apei-base.o hest.o erst.o bert.o > diff --git a/drivers/acpi/apei/apei-internal.h b/drivers/acpi/apei/apei-internal.h > index 16129c7..6e9f14c 100644 > --- a/drivers/acpi/apei/apei-internal.h > +++ b/drivers/acpi/apei/apei-internal.h > @@ -1,6 +1,6 @@ > /* > * apei-internal.h - ACPI Platform Error Interface internal > - * definations. > + * definitions. > */ > > #ifndef APEI_INTERNAL_H > diff --git a/drivers/acpi/apei/bert.c b/drivers/acpi/apei/bert.c > new file mode 100644 > index 0000000..a05b5c0 > --- /dev/null > +++ b/drivers/acpi/apei/bert.c > @@ -0,0 +1,150 @@ > +/* > + * APEI Boot Error Record Table (BERT) support > + * > + * Copyright 2011 Intel Corp. > + * Author: Huang Ying <ying.huang@xxxxxxxxx> > + * > + * Under normal circumstances, when a hardware error occurs, the error > + * handler receives control and processes the error. This gives OSPM a > + * chance to process the error condition, report it, and optionally attempt > + * recovery. In some cases, the system is unable to process an error. > + * For example, system firmware or a management controller may choose to > + * reset the system or the system might experience an uncontrolled crash > + * or reset.The boot error source is used to report unhandled errors that > + * occurred in a previous boot. This mechanism is described in the BERT > + * table. > + * > + * For more information about BERT, please refer to ACPI Specification > + * version 4.0, section 17.3.1 > + * > + * This file is licensed under GPLv2. > + * > + */ > + > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/init.h> > +#include <linux/acpi.h> > +#include <linux/io.h> > + > +#include "apei-internal.h" > + > +#undef pr_fmt > +#define pr_fmt(fmt) "BERT: " fmt > + > +static int bert_disable; > + > +static void __init bert_print_all(struct acpi_bert_region *region, > + unsigned int region_len) > +{ > + struct acpi_hest_generic_status *estatus = > + (struct acpi_hest_generic_status *)region; > + int remain = region_len; > + u32 estatus_len; > + > + if (!estatus->block_status) > + return; > + > + while (remain > sizeof(struct acpi_bert_region)) { > + if (cper_estatus_check(estatus)) { > + pr_err(FW_BUG "Invalid error record.\n"); > + return; > + } > + > + estatus_len = cper_estatus_len(estatus); > + if (remain < estatus_len) { > + pr_err(FW_BUG "Truncated status block (length: %u).\n", > + estatus_len); > + return; > + } > + > + pr_info_once("Error records from previous boot:\n"); > + > + cper_estatus_print(KERN_INFO HW_ERR, estatus); > + > + /* > + * Because the boot error source is "one-time polled" type, > + * clear Block Status of current Generic Error Status Block, > + * once it's printed. > + */ > + estatus->block_status = 0; > + > + estatus = (void *)estatus + estatus_len; > + /* No more error records. */ > + if (!estatus->block_status) > + return; > + > + remain -= estatus_len; > + } > +} > + > +static int __init setup_bert_disable(char *str) > +{ > + bert_disable = 1; > + > + return 0; > +} > +__setup("bert_disable", setup_bert_disable); > + > +static int __init bert_check_table(struct acpi_table_bert *bert_tab) > +{ > + if (bert_tab->header.length < sizeof(struct acpi_table_bert) || > + bert_tab->region_length < sizeof(struct acpi_bert_region)) > + return -EINVAL; > + > + return 0; > +} > + > +static int __init bert_init(void) > +{ > + struct acpi_bert_region *boot_error_region; > + struct acpi_table_bert *bert_tab; > + unsigned int region_len; > + acpi_status status; > + int rc = 0; > + > + if (acpi_disabled) > + return 0; > + > + if (bert_disable) { > + pr_info("Boot Error Record Table support is disabled.\n"); > + return 0; > + } > + > + status = acpi_get_table(ACPI_SIG_BERT, 0, (struct acpi_table_header **)&bert_tab); > + if (status == AE_NOT_FOUND) > + return 0; > + > + if (ACPI_FAILURE(status)) { > + pr_err("get table failed, %s.\n", acpi_format_exception(status)); > + return -EINVAL; > + } > + > + rc = bert_check_table(bert_tab); > + if (rc) { > + pr_err(FW_BUG "table invalid.\n"); > + return rc; > + } I have improved the patch following all your suggestion. I temporary keep "FW_BUG" here, But if you still think there is not a good reason to keep this, I will drop it in my next submission :-) Thanks for your help > + > + region_len = bert_tab->region_length; > + if (!request_mem_region(bert_tab->address, region_len, "APEI BERT")) { > + pr_err("Can't request iomem region <%016llx-%016llx>.\n", > + (unsigned long long)bert_tab->address, > + (unsigned long long)bert_tab->address + region_len - 1); > + return -EIO; > + } > + > + boot_error_region = ioremap_cache(bert_tab->address, region_len); > + if (boot_error_region) { > + bert_print_all(boot_error_region, region_len); > + iounmap(boot_error_region); > + } else { > + rc = -ENOMEM; > + } > + > + release_mem_region(bert_tab->address, region_len); > + > + return rc; > +} > + > +late_initcall(bert_init); > -- > 2.5.0 > -- Best regards, Fu Wei Software Engineer Red Hat Software (Beijing) Co.,Ltd.Shanghai Branch Ph: +86 21 61221326(direct) Ph: +86 186 2020 4684 (mobile) Room 1512, Regus One Corporate Avenue,Level 15, One Corporate Avenue,222 Hubin Road,Huangpu District, Shanghai,China 200021 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
