diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
new file mode 100644
index 0000000..fd0cc01
--- /dev/null
+++ b/drivers/acpi/apei/ghes.c
@@ -0,0 +1,427 @@
+/*
+ * APEI Generic Hardware Error Source support
+ *
+ * Generic Hardware Error Source provides a way to report platform
+ * hardware errors (such as that from chipset). It works in so called
+ * "Firmware First" mode, that is, hardware errors are reported to
+ * firmware firstly, then reported to Linux by firmware. This way,
+ * some non-standard hardware error registers or non-standard hardware
+ * link can be checked by firmware to produce more hardware error
+ * information for Linux.
+ *
+ * For more information about Generic Hardware Error Source, please
+ * refer to ACPI Specification version 4.0, section 17.3.2.6
+ *
+ * Now, only SCI notification type and memory errors are
+ * supported. More notification type and hardware error type will be
+ * added later.
+ *
+ * Copyright 2010 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/acpi.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/cper.h>
+#include <linux/kdebug.h>
+#include <acpi/apei.h>
+#include <acpi/atomicio.h>
+#include <acpi/hed.h>
+#include <asm/mce.h>
+
+#include "apei-internal.h"
+
+#define GHES_PFX	"GHES: "
+
+#define GHES_ESTATUS_MAX_SIZE		65536
+
+/*
+ * One struct ghes is created for each generic hardware error
+ * source.
+ *
+ * It provides the context for APEI hardware error timer/IRQ/SCI/NMI
+ * handler. Handler for one generic hardware error source is only
+ * triggered after the previous one is done. So handler can uses
+ * struct ghes without locking.
+ *
+ * estatus: memory buffer for error status block, allocated during
+ * HEST parsing.
+ */
+#define GHES_TO_CLEAR		0x0001
+
+struct ghes {
+	struct acpi_hest_generic *generic;
+	struct acpi_hest_generic_status *estatus;
+	struct list_head list;
+	u64 buffer_paddr;
+	unsigned long flags;
+};
+
+/*
+ * Error source lists, one list for each notification method. The
+ * members in lists are struct ghes.
+ *
+ * The list members are only added in HEST parsing and deleted during
+ * module_exit, that is, single-threaded. So no lock is needed for
+ * that.
+ *
+ * But the mutual exclusion is needed between members adding/deleting
+ * and timer/IRQ/SCI/NMI handler, which may traverse the list. RCU is
+ * used for that.
+ */
+static LIST_HEAD(ghes_sci);
+
+static struct ghes *ghes_new(struct acpi_hest_generic *generic)
+{
+	struct ghes *ghes;
+	unsigned int error_block_length;
+	int rc;
+
+	ghes = kzalloc(sizeof(*ghes), GFP_KERNEL);
+	if (!ghes)
+		return ERR_PTR(-ENOMEM);
+	ghes->generic = generic;
+	INIT_LIST_HEAD(&ghes->list);
+	rc = acpi_pre_map_gar(&generic->error_status_address);
+	if (rc)
+		goto err_free;
+	error_block_length = generic->error_block_length;
+	if (error_block_length > GHES_ESTATUS_MAX_SIZE) {
+		pr_warning(FW_WARN GHES_PFX
+			   "Error status block length is too long: %u for "
+			   "generic hardware error source: %d.\n",
+			   error_block_length, generic->header.source_id);
+		error_block_length = GHES_ESTATUS_MAX_SIZE;
+	}
+	ghes->estatus = kmalloc(error_block_length, GFP_KERNEL);
+	if (!ghes->estatus) {
+		rc = -ENOMEM;
+		goto err_unmap;
+	}
+
+	return ghes;
+
+err_unmap:
+	acpi_post_unmap_gar(&generic->error_status_address);
+err_free:
+	kfree(ghes);
+	return ERR_PTR(rc);
+}
+
+static void ghes_fini(struct ghes *ghes)
+{
+	kfree(ghes->estatus);
+	acpi_post_unmap_gar(&ghes->generic->error_status_address);
+}
+
+enum {
+	GHES_SER_NO = 0x0,
+	GHES_SER_CORRECTED = 0x1,
+	GHES_SER_RECOVERABLE = 0x2,
+	GHES_SER_PANIC = 0x3,
+};
+
+static inline int ghes_severity(int severity)
+{
+	switch (severity) {
+	case CPER_SER_INFORMATIONAL:
+		return GHES_SER_NO;
+	case CPER_SER_CORRECTED:
+		return GHES_SER_CORRECTED;
+	case CPER_SER_RECOVERABLE:
+		return GHES_SER_RECOVERABLE;
+	case CPER_SER_FATAL:
+		return GHES_SER_PANIC;
+	default:
+		/* Unkown, go panic */
+		return GHES_SER_PANIC;
+	}
+}
+
+/* SCI handler run in work queue, so ioremap can be used here */
+static int ghes_copy_tofrom_phys(void *buffer, u64 paddr, u32 len,
+				 int from_phys)
+{
+	void *vaddr;
+
+	vaddr = ioremap_cache(paddr, len);
+	if (!vaddr)
+		return -ENOMEM;
+	if (from_phys)
+		memcpy(buffer, vaddr, len);
+	else
+		memcpy(vaddr, buffer, len);
+	iounmap(vaddr);
+
+	return 0;
+}
+
+static int ghes_read_estatus(struct ghes *ghes, int silent)
+{
+	struct acpi_hest_generic *g = ghes->generic;
+	u64 buf_paddr;
+	u32 len;
+	int rc;
+
+	rc = acpi_atomic_read(&buf_paddr, &g->error_status_address);
+	if (rc) {
+		if (!silent && printk_ratelimit())
+			pr_warning(FW_WARN GHES_PFX
+"Failed to read error status block address for hardware error source: %d.\n",
+				   g->header.source_id);
+		return -EIO;
+	}
+	if (!buf_paddr)
+		return -ENOENT;
+
+	rc = ghes_copy_tofrom_phys(ghes->estatus, buf_paddr,
+				   sizeof(*ghes->estatus), 1);
+	if (rc)
+		return rc;
+	if (!ghes->estatus->block_status)
+		return -ENOENT;
+
+	ghes->buffer_paddr = buf_paddr;
+	ghes->flags |= GHES_TO_CLEAR;
+
+	rc = -EIO;
+	len = apei_estatus_len(ghes->estatus);
+	if (len < sizeof(*ghes->estatus))
+		goto err_read_block;
+	if (len > ghes->generic->error_block_length)
+		goto err_read_block;
+	if (apei_estatus_check_header(ghes->estatus))
+		goto err_read_block;
+	rc = ghes_copy_tofrom_phys(ghes->estatus + 1,
+				   buf_paddr + sizeof(*ghes->estatus),
+				   len - sizeof(*ghes->estatus), 1);
+	if (rc)
+		return rc;
+	if (apei_estatus_check(ghes->estatus))
+		goto err_read_block;
+	rc = 0;
+
+err_read_block:
+	if (rc && !silent)
+		pr_warning(FW_WARN GHES_PFX
+			   "Failed to read error status block!\n");
+	return rc;
+}
+
+static void ghes_clear_estatus(struct ghes *ghes)
+{
+	ghes->estatus->block_status = 0;
+	if (!(ghes->flags & GHES_TO_CLEAR))
+		return;
+	ghes_copy_tofrom_phys(ghes->estatus, ghes->buffer_paddr,
+			      sizeof(ghes->estatus->block_status), 0);
+	ghes->flags &= ~GHES_TO_CLEAR;
+}
+
+static void ghes_do_proc(struct ghes *ghes)
+{
+	int ser, processed = 0;
+	struct acpi_hest_generic_data *gdata;
+
+	ser = ghes_severity(ghes->estatus->error_severity);
+	apei_estatus_for_each_section(ghes->estatus, gdata) {
+#ifdef CONFIG_X86_MCE
+		if (!uuid_le_cmp(*(uuid_le *)gdata->section_type,
+				 CPER_SEC_PLATFORM_MEM)) {
+			apei_mce_report_mem_error(
+				ser == GHES_SER_CORRECTED,
+				(struct cper_sec_mem_err *)(gdata+1));
+			processed = 1;
+		}
+#endif
+	}
+
+	if (!processed && printk_ratelimit())
+		pr_warning(GHES_PFX
+		"Unknown error record from generic hardware error source: %d\n",
+			   ghes->generic->header.source_id);
+}
+
+static int ghes_proc(struct ghes *ghes)
+{
+	int rc;
+
+	rc = ghes_read_estatus(ghes, 0);
+	if (rc)
+		goto out;
+	ghes_do_proc(ghes);
+
+out:
+	ghes_clear_estatus(ghes);
+	return 0;
+}
+
+static int ghes_notify_sci(struct notifier_block *this,
+				  unsigned long event, void *data)
+{
+	struct ghes *ghes;
+	int ret = NOTIFY_DONE;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(ghes, &ghes_sci, list) {
+		if (!ghes_proc(ghes))
+			ret = NOTIFY_OK;
+	}
+	rcu_read_unlock();
+
+	return ret;
+}
+
+static struct notifier_block ghes_notifier_sci = {
+	.notifier_call = ghes_notify_sci,
+};
+
+static int hest_ghes_parse(struct acpi_hest_header *hest_hdr, void *data)
+{
+	struct acpi_hest_generic *generic;
+	struct ghes *ghes = NULL;
+	int rc = 0;
+
+	if (hest_hdr->type != ACPI_HEST_TYPE_GENERIC_ERROR)
+		return 0;
+
+	generic = (struct acpi_hest_generic *)hest_hdr;
+	if (!generic->enabled)
+		return 0;
+
+	if (generic->error_block_length <
+	    sizeof(struct acpi_hest_generic_status)) {
+		pr_warning(FW_BUG GHES_PFX
+"Invalid error block length: %u for generic hardware error source: %d\n",
+			   generic->error_block_length,
+			   generic->header.source_id);
+		goto err;
+	}
+	if (generic->records_to_preallocate == 0) {
+		pr_warning(FW_BUG GHES_PFX
+"Invalid records to preallocate: %u for generic hardware error source: %d\n",
+			   generic->records_to_preallocate,
+			   generic->header.source_id);
+		goto err;
+	}
+	ghes = ghes_new(generic);
+	if (IS_ERR(ghes)) {
+		rc = PTR_ERR(ghes);
+		ghes = NULL;
+		goto err;
+	}
+	switch (generic->notify.type) {
+	case ACPI_HEST_NOTIFY_POLLED:
+		pr_warning(GHES_PFX
+"Generic hardware error source: %d notified via POLL is not supported!\n",
+			   generic->header.source_id);
+		break;
+	case ACPI_HEST_NOTIFY_EXTERNAL:
+	case ACPI_HEST_NOTIFY_LOCAL:
+		pr_warning(GHES_PFX
+"Generic hardware error source: %d notified via IRQ is not supported!\n",
+			   generic->header.source_id);
+		break;
+	case ACPI_HEST_NOTIFY_SCI:
+		if (list_empty(&ghes_sci))
+			register_acpi_hed_notifier(&ghes_notifier_sci);
+		list_add_rcu(&ghes->list, &ghes_sci);
+		break;
+	case ACPI_HEST_NOTIFY_NMI:
+		pr_warning(GHES_PFX
+"Generic hardware error source: %d notified via NMI is not supported!\n",
+			   generic->header.source_id);
+		break;
+	default:
+		pr_warning(FW_WARN GHES_PFX
+	"Unknown notification type: %u for generic hardware error source: %d\n",
+			   generic->notify.type, generic->header.source_id);
+		break;
+	}
+
+	return 0;
+err:
+	if (ghes)
+		ghes_fini(ghes);
+	return rc;
+}
+
+static void ghes_cleanup(void)
+{
+	struct ghes *ghes, *nghes;
+
+	if (!list_empty(&ghes_sci))
+		unregister_acpi_hed_notifier(&ghes_notifier_sci);
+
+	synchronize_rcu();
+
+	list_for_each_entry_safe(ghes, nghes, &ghes_sci, list) {
+		list_del(&ghes->list);
+		ghes_fini(ghes);
+		kfree(ghes);
+	}
+}
+
+static int __init ghes_init(void)
+{
+	int rc;
+
+	if (acpi_disabled)
+		return -ENODEV;
+
+	if (hest_disable) {
+		pr_info(GHES_PFX "HEST is not enabled!\n");
+		return -EINVAL;
+	}
+
+	rc = apei_hest_parse(hest_ghes_parse, NULL);
+	if (rc) {
+		pr_err(GHES_PFX
+		"Error during parsing HEST generic hardware error sources.\n");
+		goto err_cleanup;
+	}
+
+	if (list_empty(&ghes_sci)) {
+		pr_info(GHES_PFX
+			"No functional generic hardware error sources.\n");
+		rc = -ENODEV;
+		goto err_cleanup;
+	}
+
+	pr_info(GHES_PFX
+		"Generic Hardware Error Source support is initialized.\n");
+
+	return 0;
+err_cleanup:
+	ghes_cleanup();
+	return rc;
+}
+
+static void __exit ghes_exit(void)
+{
+	ghes_cleanup();
+}
+
+module_init(ghes_init);
+module_exit(ghes_exit);
+
+MODULE_AUTHOR("Huang Ying");
+MODULE_DESCRIPTION("APEI Generic Hardware Error Source support");
+MODULE_LICENSE("GPL");