ACPI Hardware Error Device (PNP0C33) support

Hardware Error Device (PNP0C33) is used to report some hardware errors
notified via SCI, mainly the corrected errors. Some APEI Generic
Hardware Error Source (GHES) may use SCI on hardware error device to
notify hardware error to kernel.

After receiving notification from ACPI core, it is forwarded to all
listeners via a notifier chain. The listener such as APEI GHES should
check corresponding error source for new events when notified.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/Kconfig

@@ -360,6 +360,13 @@ config ACPI_SBS
 	  To compile this driver as a module, choose M here:
 	  the modules will be called sbs and sbshc.
 
+config ACPI_HED
+	tristate "Hardware Error Device"
+	help
+	  This driver supports the Hardware Error Device (PNP0C33),
+	  which is used to report some hardware errors notified via
+	  SCI, mainly the corrected errors.
+
 source "drivers/acpi/apei/Kconfig"
 
 endif	# ACPI

drivers/acpi/Makefile

@@ -59,6 +59,7 @@ obj-$(CONFIG_ACPI_BATTERY)	+= battery.o
 obj-$(CONFIG_ACPI_SBS)		+= sbshc.o
 obj-$(CONFIG_ACPI_SBS)		+= sbs.o
 obj-$(CONFIG_ACPI_POWER_METER)	+= power_meter.o
+obj-$(CONFIG_ACPI_HED)		+= hed.o
 
 # processor has its own "processor." module_param namespace
 processor-y			:= processor_driver.o processor_throttling.o

drivers/acpi/hed.c

+/*
+ * ACPI Hardware Error Device (PNP0C33) Driver
+ *
+ * Copyright (C) 2010, Intel Corp.
+ *	Author: Huang Ying <ying.huang@intel.com>
+ *
+ * ACPI Hardware Error Device is used to report some hardware errors
+ * notified via SCI, mainly the corrected errors.
+ *
+ * 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 <acpi/acpi_bus.h>
+#include <acpi/acpi_drivers.h>
+#include <acpi/hed.h>
+
+static struct acpi_device_id acpi_hed_ids[] = {
+	{"PNP0C33", 0},
+	{"", 0},
+};
+MODULE_DEVICE_TABLE(acpi, acpi_hed_ids);
+
+static acpi_handle hed_handle;
+
+static BLOCKING_NOTIFIER_HEAD(acpi_hed_notify_list);
+
+int register_acpi_hed_notifier(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_register(&acpi_hed_notify_list, nb);
+}
+EXPORT_SYMBOL_GPL(register_acpi_hed_notifier);
+
+void unregister_acpi_hed_notifier(struct notifier_block *nb)
+{
+	blocking_notifier_chain_unregister(&acpi_hed_notify_list, nb);
+}
+EXPORT_SYMBOL_GPL(unregister_acpi_hed_notifier);
+
+/*
+ * SCI to report hardware error is forwarded to the listeners of HED,
+ * it is used by HEST Generic Hardware Error Source with notify type
+ * SCI.
+ */
+static void acpi_hed_notify(struct acpi_device *device, u32 event)
+{
+	blocking_notifier_call_chain(&acpi_hed_notify_list, 0, NULL);
+}
+
+static int __devinit acpi_hed_add(struct acpi_device *device)
+{
+	/* Only one hardware error device */
+	if (hed_handle)
+		return -EINVAL;
+	hed_handle = device->handle;
+	return 0;
+}
+
+static int __devexit acpi_hed_remove(struct acpi_device *device, int type)
+{
+	hed_handle = NULL;
+	return 0;
+}
+
+static struct acpi_driver acpi_hed_driver = {
+	.name = "hardware_error_device",
+	.class = "hardware_error",
+	.ids = acpi_hed_ids,
+	.ops = {
+		.add = acpi_hed_add,
+		.remove = acpi_hed_remove,
+		.notify = acpi_hed_notify,
+	},
+};
+
+static int __init acpi_hed_init(void)
+{
+	if (acpi_disabled)
+		return -ENODEV;
+
+	if (acpi_bus_register_driver(&acpi_hed_driver) < 0)
+		return -ENODEV;
+
+	return 0;
+}
+
+static void __exit acpi_hed_exit(void)
+{
+	acpi_bus_unregister_driver(&acpi_hed_driver);
+}
+
+module_init(acpi_hed_init);
+module_exit(acpi_hed_exit);
+
+ACPI_MODULE_NAME("hed");
+MODULE_AUTHOR("Huang Ying");
+MODULE_DESCRIPTION("ACPI Hardware Error Device Driver");
+MODULE_LICENSE("GPL");

include/acpi/hed.h

+/*
+ * hed.h - ACPI Hardware Error Device
+ *
+ * Copyright (C) 2009, Intel Corp.
+ *	Author: Huang Ying <ying.huang@intel.com>
+ *
+ * This file is released under the GPLv2.
+ */
+
+#ifndef ACPI_HED_H
+#define ACPI_HED_H
+
+#include <linux/notifier.h>
+
+int register_acpi_hed_notifier(struct notifier_block *nb);
+void unregister_acpi_hed_notifier(struct notifier_block *nb);
+
+#endif