v4.19.13 snapshot.
diff --git a/drivers/acpi/apei/hest.c b/drivers/acpi/apei/hest.c
new file mode 100644
index 0000000..b1e9f81
--- /dev/null
+++ b/drivers/acpi/apei/hest.c
@@ -0,0 +1,263 @@
+/*
+ * APEI Hardware Error Souce Table support
+ *
+ * HEST describes error sources in detail; communicates operational
+ * parameters (i.e. severity levels, masking bits, and threshold
+ * values) to Linux as necessary. It also allows the BIOS to report
+ * non-standard error sources to Linux (for example, chipset-specific
+ * error registers).
+ *
+ * For more information about HEST, please refer to ACPI Specification
+ * version 4.0, section 17.3.2.
+ *
+ * Copyright 2009 Intel Corp.
+ *   Author: Huang Ying <ying.huang@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation;
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/acpi.h>
+#include <linux/kdebug.h>
+#include <linux/highmem.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <acpi/apei.h>
+
+#include "apei-internal.h"
+
+#define HEST_PFX "HEST: "
+
+int hest_disable;
+EXPORT_SYMBOL_GPL(hest_disable);
+
+/* HEST table parsing */
+
+static struct acpi_table_hest *__read_mostly hest_tab;
+
+static const int hest_esrc_len_tab[ACPI_HEST_TYPE_RESERVED] = {
+	[ACPI_HEST_TYPE_IA32_CHECK] = -1,	/* need further calculation */
+	[ACPI_HEST_TYPE_IA32_CORRECTED_CHECK] = -1,
+	[ACPI_HEST_TYPE_IA32_NMI] = sizeof(struct acpi_hest_ia_nmi),
+	[ACPI_HEST_TYPE_AER_ROOT_PORT] = sizeof(struct acpi_hest_aer_root),
+	[ACPI_HEST_TYPE_AER_ENDPOINT] = sizeof(struct acpi_hest_aer),
+	[ACPI_HEST_TYPE_AER_BRIDGE] = sizeof(struct acpi_hest_aer_bridge),
+	[ACPI_HEST_TYPE_GENERIC_ERROR] = sizeof(struct acpi_hest_generic),
+	[ACPI_HEST_TYPE_GENERIC_ERROR_V2] = sizeof(struct acpi_hest_generic_v2),
+};
+
+static int hest_esrc_len(struct acpi_hest_header *hest_hdr)
+{
+	u16 hest_type = hest_hdr->type;
+	int len;
+
+	if (hest_type >= ACPI_HEST_TYPE_RESERVED)
+		return 0;
+
+	len = hest_esrc_len_tab[hest_type];
+
+	if (hest_type == ACPI_HEST_TYPE_IA32_CORRECTED_CHECK) {
+		struct acpi_hest_ia_corrected *cmc;
+		cmc = (struct acpi_hest_ia_corrected *)hest_hdr;
+		len = sizeof(*cmc) + cmc->num_hardware_banks *
+			sizeof(struct acpi_hest_ia_error_bank);
+	} else if (hest_type == ACPI_HEST_TYPE_IA32_CHECK) {
+		struct acpi_hest_ia_machine_check *mc;
+		mc = (struct acpi_hest_ia_machine_check *)hest_hdr;
+		len = sizeof(*mc) + mc->num_hardware_banks *
+			sizeof(struct acpi_hest_ia_error_bank);
+	}
+	BUG_ON(len == -1);
+
+	return len;
+};
+
+int apei_hest_parse(apei_hest_func_t func, void *data)
+{
+	struct acpi_hest_header *hest_hdr;
+	int i, rc, len;
+
+	if (hest_disable || !hest_tab)
+		return -EINVAL;
+
+	hest_hdr = (struct acpi_hest_header *)(hest_tab + 1);
+	for (i = 0; i < hest_tab->error_source_count; i++) {
+		len = hest_esrc_len(hest_hdr);
+		if (!len) {
+			pr_warning(FW_WARN HEST_PFX
+				   "Unknown or unused hardware error source "
+				   "type: %d for hardware error source: %d.\n",
+				   hest_hdr->type, hest_hdr->source_id);
+			return -EINVAL;
+		}
+		if ((void *)hest_hdr + len >
+		    (void *)hest_tab + hest_tab->header.length) {
+			pr_warning(FW_BUG HEST_PFX
+		"Table contents overflow for hardware error source: %d.\n",
+				hest_hdr->source_id);
+			return -EINVAL;
+		}
+
+		rc = func(hest_hdr, data);
+		if (rc)
+			return rc;
+
+		hest_hdr = (void *)hest_hdr + len;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(apei_hest_parse);
+
+/*
+ * Check if firmware advertises firmware first mode. We need FF bit to be set
+ * along with a set of MC banks which work in FF mode.
+ */
+static int __init hest_parse_cmc(struct acpi_hest_header *hest_hdr, void *data)
+{
+	if (hest_hdr->type != ACPI_HEST_TYPE_IA32_CORRECTED_CHECK)
+		return 0;
+
+	if (!acpi_disable_cmcff)
+		return !arch_apei_enable_cmcff(hest_hdr, data);
+
+	return 0;
+}
+
+struct ghes_arr {
+	struct platform_device **ghes_devs;
+	unsigned int count;
+};
+
+static int __init hest_parse_ghes_count(struct acpi_hest_header *hest_hdr, void *data)
+{
+	int *count = data;
+
+	if (hest_hdr->type == ACPI_HEST_TYPE_GENERIC_ERROR ||
+	    hest_hdr->type == ACPI_HEST_TYPE_GENERIC_ERROR_V2)
+		(*count)++;
+	return 0;
+}
+
+static int __init hest_parse_ghes(struct acpi_hest_header *hest_hdr, void *data)
+{
+	struct platform_device *ghes_dev;
+	struct ghes_arr *ghes_arr = data;
+	int rc, i;
+
+	if (hest_hdr->type != ACPI_HEST_TYPE_GENERIC_ERROR &&
+	    hest_hdr->type != ACPI_HEST_TYPE_GENERIC_ERROR_V2)
+		return 0;
+
+	if (!((struct acpi_hest_generic *)hest_hdr)->enabled)
+		return 0;
+	for (i = 0; i < ghes_arr->count; i++) {
+		struct acpi_hest_header *hdr;
+		ghes_dev = ghes_arr->ghes_devs[i];
+		hdr = *(struct acpi_hest_header **)ghes_dev->dev.platform_data;
+		if (hdr->source_id == hest_hdr->source_id) {
+			pr_warning(FW_WARN HEST_PFX "Duplicated hardware error source ID: %d.\n",
+				   hdr->source_id);
+			return -EIO;
+		}
+	}
+	ghes_dev = platform_device_alloc("GHES", hest_hdr->source_id);
+	if (!ghes_dev)
+		return -ENOMEM;
+
+	rc = platform_device_add_data(ghes_dev, &hest_hdr, sizeof(void *));
+	if (rc)
+		goto err;
+
+	rc = platform_device_add(ghes_dev);
+	if (rc)
+		goto err;
+	ghes_arr->ghes_devs[ghes_arr->count++] = ghes_dev;
+
+	return 0;
+err:
+	platform_device_put(ghes_dev);
+	return rc;
+}
+
+static int __init hest_ghes_dev_register(unsigned int ghes_count)
+{
+	int rc, i;
+	struct ghes_arr ghes_arr;
+
+	ghes_arr.count = 0;
+	ghes_arr.ghes_devs = kmalloc_array(ghes_count, sizeof(void *),
+					   GFP_KERNEL);
+	if (!ghes_arr.ghes_devs)
+		return -ENOMEM;
+
+	rc = apei_hest_parse(hest_parse_ghes, &ghes_arr);
+	if (rc)
+		goto err;
+out:
+	kfree(ghes_arr.ghes_devs);
+	return rc;
+err:
+	for (i = 0; i < ghes_arr.count; i++)
+		platform_device_unregister(ghes_arr.ghes_devs[i]);
+	goto out;
+}
+
+static int __init setup_hest_disable(char *str)
+{
+	hest_disable = HEST_DISABLED;
+	return 0;
+}
+
+__setup("hest_disable", setup_hest_disable);
+
+void __init acpi_hest_init(void)
+{
+	acpi_status status;
+	int rc = -ENODEV;
+	unsigned int ghes_count = 0;
+
+	if (hest_disable) {
+		pr_info(HEST_PFX "Table parsing disabled.\n");
+		return;
+	}
+
+	status = acpi_get_table(ACPI_SIG_HEST, 0,
+				(struct acpi_table_header **)&hest_tab);
+	if (status == AE_NOT_FOUND) {
+		hest_disable = HEST_NOT_FOUND;
+		return;
+	} else if (ACPI_FAILURE(status)) {
+		const char *msg = acpi_format_exception(status);
+		pr_err(HEST_PFX "Failed to get table, %s\n", msg);
+		rc = -EINVAL;
+		goto err;
+	}
+
+	rc = apei_hest_parse(hest_parse_cmc, NULL);
+	if (rc)
+		goto err;
+
+	if (!ghes_disable) {
+		rc = apei_hest_parse(hest_parse_ghes_count, &ghes_count);
+		if (rc)
+			goto err;
+		rc = hest_ghes_dev_register(ghes_count);
+		if (rc)
+			goto err;
+	}
+
+	pr_info(HEST_PFX "Table parsing has been initialized.\n");
+	return;
+err:
+	hest_disable = HEST_DISABLED;
+}