v4.19.13 snapshot.
diff --git a/drivers/acpi/apei/bert.c b/drivers/acpi/apei/bert.c
new file mode 100644
index 0000000..12771fc
--- /dev/null
+++ b/drivers/acpi/apei/bert.c
@@ -0,0 +1,154 @@
+/*
+ * APEI Boot Error Record Table (BERT) support
+ *
+ * Copyright 2011 Intel Corp.
+ * Author: Huang Ying <ying.huang@intel.com>
+ *
+ * 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 apei_resources bert_resources;
+ 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;
+ 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);
+ iounmap(boot_error_region);
+ } else {
+ rc = -ENOMEM;
+ }
+
+ apei_resources_release(&bert_resources);
+out_fini:
+ apei_resources_fini(&bert_resources);
+
+ return rc;
+}
+
+late_initcall(bert_init);