From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Luck, Tony" Subject: [PATCH v5 2/2] ACPI / APEI: Boot Error Record Table processing was needlessly complicated Date: Wed, 21 Jun 2017 10:20:42 -0700 Message-ID: References: <20170619155854.gtcowx3cityb3gqt@pd.tnic> Return-path: Received: from mga06.intel.com ([134.134.136.31]:20642 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753034AbdFURVP (ORCPT ); Wed, 21 Jun 2017 13:21:15 -0400 In-Reply-To: In-Reply-To: References: Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: "Rafael J . Wysocki" Cc: Tony Luck , Len Brown , Huang Ying , Borislav Petkov , Tomasz Nowicki , Jonathan Zhang , Tyler Baicar , linux-acpi@vger.kernel.org From: Tony Luck Quoting version 6.1 of the ACPI specification. Section 18.3.1 "Boot Error Source" says: The Boot Error Region is a range of addressable memory OSPM can access during initialization to determine if an unhandled error condition occurred. System firmware must report this memory range as firmware reserved. The format of the Boot Error Region follow that of an Error Status Block, this is defined in Section 18.3.2.7. The format of the error status block is described by Table 18-342. This clarifies some points that were obfuscated in earlier versions. E.g. there is no longer a separate table to describe the format of the "Boot Error Region" (which was identical to the "Error Status Block"). Also saying "follow that of *an* Error Status Block" makes it clear that there is just one block (which can still contain multiple "Generic Error Data Entry structures"). The loop inside bert_print_all() is unnecessary (but probably harmless as the "while (remain > sizeof(struct acpi_bert_region))" loop should terminate after we skipped over the first entry. We can drop the "bert_print_all()" function and just move the four relevant lines inline in "bert_init()". Cc: Len Brown Cc: Huang Ying Cc: Borislav Petkov Cc: Tomasz Nowicki Cc: Jonathan (Zhixiong) Zhang Cc: Tyler Baicar Cc: linux-acpi@vger.kernel.org Signed-off-by: Tony Luck --- drivers/acpi/apei/bert.c | 52 +++++++++++------------------------------------- 1 file changed, 12 insertions(+), 40 deletions(-) diff --git a/drivers/acpi/apei/bert.c b/drivers/acpi/apei/bert.c index 9197555dc3c7..3b9b296dc84e 100644 --- a/drivers/acpi/apei/bert.c +++ b/drivers/acpi/apei/bert.c @@ -34,43 +34,6 @@ 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); - - 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; @@ -82,7 +45,7 @@ __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)) + bert_tab->region_length < sizeof(struct acpi_hest_generic_status)) return -EINVAL; return 0; @@ -91,7 +54,7 @@ static int __init bert_check_table(struct acpi_table_bert *bert_tab) static int __init bert_init(void) { struct apei_resources bert_resources; - struct acpi_bert_region *boot_error_region; + struct acpi_hest_generic_status *boot_error_region; struct acpi_table_bert *bert_tab; unsigned int region_len; acpi_status status; @@ -131,7 +94,16 @@ static int __init bert_init(void) goto out_fini; boot_error_region = ioremap_cache(bert_tab->address, region_len); if (boot_error_region) { - bert_print_all(boot_error_region, region_len); + if (boot_error_region->block_status) { + rc = cper_estatus_check(boot_error_region); + if (rc) { + pr_err(FW_BUG "Invalid error record.\n"); + iounmap(boot_error_region); + return rc; + } + pr_info("Error records from previous boot:\n"); + cper_estatus_print(KERN_INFO HW_ERR, boot_error_region); + } iounmap(boot_error_region); } else { rc = -ENOMEM; -- 2.11.0