From 41139ac3cd76c6dff8286102a8ac62933c680463 Mon Sep 17 00:00:00 2001 From: Huang Ying Date: Mon, 20 Feb 2017 09:12:58 +0800 Subject: [PATCH] ACPI: APEI: Fix BERT resources conflict with ACPI NVS area It was reported that on some machines, there is overlap between ACPI NVS area and BERT address range. This appears reasonable because BERT contents need to be non-volatile across reboot. But this will cause resources conflict in current Linux kernel implementation because the ACPI NVS area is marked as busy. The resource conflict is fixed via excluding the ACPI NVS area when requesting IO resources for BERT. When accessing the BERT contents, the whole BERT address range will be ioremapped and accessed. Reported-and-tested-by: Hans Kristian Rosbach Signed-off-by: Ying Huang Acked-by: Borislav Petkov Signed-off-by: Rafael J. Wysocki --- drivers/acpi/apei/bert.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/drivers/acpi/apei/bert.c b/drivers/acpi/apei/bert.c index a05b5c0cf181..12771fcf0417 100644 --- a/drivers/acpi/apei/bert.c +++ b/drivers/acpi/apei/bert.c @@ -97,6 +97,7 @@ 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_table_bert *bert_tab; unsigned int region_len; @@ -127,13 +128,14 @@ static int __init bert_init(void) } 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; - } - + apei_resources_init(&bert_resources); + rc = apei_resources_add(&bert_resources, bert_tab->address, + region_len, true); + if (rc) + return rc; + rc = apei_resources_request(&bert_resources, "APEI BERT"); + if (rc) + 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); @@ -142,7 +144,9 @@ static int __init bert_init(void) rc = -ENOMEM; } - release_mem_region(bert_tab->address, region_len); + apei_resources_release(&bert_resources); +out_fini: + apei_resources_fini(&bert_resources); return rc; } -- 2.20.1