Re: [PATCH v3] acpi, apei: add Boot Error Record Table (BERT) support

[Fu Wei]

Hi Borislav,


On 7 January 2016 at 19:27,  <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 error.
>
> BERT: Obtained BERT iomem region <00000000fe801000-00000000fe802000> for BERT.
> [Hardware Error]: Error record from previous boot:
> [Hardware Error]: event severity: fatal
> [Hardware Error]:  Error 0, type: fatal
> [Hardware Error]:   section_type: memory error
> [Hardware Error]:   physical_address: 0x00000000fe800000
> [Hardware Error]:   physical_address_mask: 0x0000000000000fff
> [Hardware Error]:   card: 0 module: 1 bank: 0 device: 1 row: 1 column: 1 bit_pos
>
> [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:
> v3: 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/bert.c            | 158 ++++++++++++++++++++++++++++++++++++
>  include/acpi/apei.h                 |   1 +
>  4 files changed, 163 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/acpi/apei/bert.c
>
> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
> index 742f69d..2310e97 100644
> --- a/Documentation/kernel-parameters.txt
> +++ b/Documentation/kernel-parameters.txt
> @@ -555,6 +555,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
>
>         bootmem_debug   [KNL] Enable bootmem allocator debug messages.
>
> +       bert_disable    [ACPI]
> +                       Disable Boot Error Record Table (BERT) support.
> +

This comes from the original version of BERT patch
But I don't think we need this, and I don't see any benefit of this.

Any suggestion ? Or anything I missed?


>         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/bert.c b/drivers/acpi/apei/bert.c
> new file mode 100644
> index 0000000..6f6ae38
> --- /dev/null
> +++ b/drivers/acpi/apei/bert.c
> @@ -0,0 +1,158 @@
> +/*
> + * 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, 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.
> + *
> + * 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(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)
> +{
> +       /*
> +        * We use cper_estatus_* which uses struct acpi_hest_generic_status,
> +        * struct acpi_hest_generic_status and acpi_bert_region are the same
> +        * (Generic Error Status Block), so we declare the "estatus" here.
> +        */
> +       struct acpi_hest_generic_status *estatus =
> +               (struct acpi_hest_generic_status *)region;
> +       int remain = region_len;
> +       u32 estatus_len;
> +
> +       /* The records have been polled*/
> +       if (!estatus->block_status)
> +               return;
> +
> +       while (remain > sizeof(struct acpi_bert_region)) {
> +               /*
> +                * Test Generic Error Status Block first,
> +                * if the data(Offset, Length) is invalid, we just return,
> +                * because we can't trust the length data from this block.
> +                */
> +               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 "Invalid status block length (%u)\n",
> +                              estatus_len);
> +                       return;
> +               }
> +
> +               pr_info_once(HW_ERR "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;
> +               if (!estatus->block_status)
> +                       return; /* No more error records */
> +
> +               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;
> +       }
> +
> +       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);
> diff --git a/include/acpi/apei.h b/include/acpi/apei.h
> index 76284bb..284801a 100644
> --- a/include/acpi/apei.h
> +++ b/include/acpi/apei.h
> @@ -23,6 +23,7 @@ extern bool ghes_disable;
>  #else
>  #define ghes_disable 1
>  #endif
> +extern int bert_disable;
>
>  #ifdef CONFIG_ACPI_APEI
>  void __init acpi_hest_init(void);
> --
> 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
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