Merge tag 'pm+acpi-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI and power management updates from Rafael J Wysocki:

 - New power capping framework and the the Intel Running Average Power
   Limit (RAPL) driver using it from Srinivas Pandruvada and Jacob Pan.

 - Addition of the in-kernel switching feature to the arm_big_little
   cpufreq driver from Viresh Kumar and Nicolas Pitre.

 - cpufreq support for iMac G5 from Aaro Koskinen.

 - Baytrail processors support for intel_pstate from Dirk Brandewie.

 - cpufreq support for Midway/ECX-2000 from Mark Langsdorf.

 - ARM vexpress/TC2 cpufreq support from Sudeep KarkadaNagesha.

 - ACPI power management support for the I2C and SPI bus types from Mika
   Westerberg and Lv Zheng.

 - cpufreq core fixes and cleanups from Viresh Kumar, Srivatsa S Bhat,
   Stratos Karafotis, Xiaoguang Chen, Lan Tianyu.

 - cpufreq drivers updates (mostly fixes and cleanups) from Viresh
   Kumar, Aaro Koskinen, Jungseok Lee, Sudeep KarkadaNagesha, Lukasz
   Majewski, Manish Badarkhe, Hans-Christian Egtvedt, Evgeny Kapaev.

 - intel_pstate updates from Dirk Brandewie and Adrian Huang.

 - ACPICA update to version 20130927 includig fixes and cleanups and
   some reduction of divergences between the ACPICA code in the kernel
   and ACPICA upstream in order to improve the automatic ACPICA patch
   generation process.  From Bob Moore, Lv Zheng, Tomasz Nowicki, Naresh
   Bhat, Bjorn Helgaas, David E Box.

 - ACPI IPMI driver fixes and cleanups from Lv Zheng.

 - ACPI hotplug fixes and cleanups from Bjorn Helgaas, Toshi Kani, Zhang
   Yanfei, Rafael J Wysocki.

 - Conversion of the ACPI AC driver to the platform bus type and
   multiple driver fixes and cleanups related to ACPI from Zhang Rui.

 - ACPI processor driver fixes and cleanups from Hanjun Guo, Jiang Liu,
   Bartlomiej Zolnierkiewicz, Mathieu Rhéaume, Rafael J Wysocki.

 - Fixes and cleanups and new blacklist entries related to the ACPI
   video support from Aaron Lu, Felipe Contreras, Lennart Poettering,
   Kirill Tkhai.

 - cpuidle core cleanups from Viresh Kumar and Lorenzo Pieralisi.

 - cpuidle drivers fixes and cleanups from Daniel Lezcano, Jingoo Han,
   Bartlomiej Zolnierkiewicz, Prarit Bhargava.

 - devfreq updates from Sachin Kamat, Dan Carpenter, Manish Badarkhe.

 - Operation Performance Points (OPP) core updates from Nishanth Menon.

 - Runtime power management core fix from Rafael J Wysocki and update
   from Ulf Hansson.

 - Hibernation fixes from Aaron Lu and Rafael J Wysocki.

 - Device suspend/resume lockup detection mechanism from Benoit Goby.

 - Removal of unused proc directories created for various ACPI drivers
   from Lan Tianyu.

 - ACPI LPSS driver fix and new device IDs for the ACPI platform scan
   handler from Heikki Krogerus and Jarkko Nikula.

 - New ACPI _OSI blacklist entry for Toshiba NB100 from Levente Kurusa.

 - Assorted fixes and cleanups related to ACPI from Andy Shevchenko, Al
   Stone, Bartlomiej Zolnierkiewicz, Colin Ian King, Dan Carpenter,
   Felipe Contreras, Jianguo Wu, Lan Tianyu, Yinghai Lu, Mathias Krause,
   Liu Chuansheng.

 - Assorted PM fixes and cleanups from Andy Shevchenko, Thierry Reding,
   Jean-Christophe Plagniol-Villard.

* tag 'pm+acpi-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (386 commits)
  cpufreq: conservative: fix requested_freq reduction issue
  ACPI / hotplug: Consolidate deferred execution of ACPI hotplug routines
  PM / runtime: Use pm_runtime_put_sync() in __device_release_driver()
  ACPI / event: remove unneeded NULL pointer check
  Revert "ACPI / video: Ignore BIOS initial backlight value for HP 250 G1"
  ACPI / video: Quirk initial backlight level 0
  ACPI / video: Fix initial level validity test
  intel_pstate: skip the driver if ACPI has power mgmt option
  PM / hibernate: Avoid overflow in hibernate_preallocate_memory()
  ACPI / hotplug: Do not execute "insert in progress" _OST
  ACPI / hotplug: Carry out PCI root eject directly
  ACPI / hotplug: Merge device hot-removal routines
  ACPI / hotplug: Make acpi_bus_hot_remove_device() internal
  ACPI / hotplug: Simplify device ejection routines
  ACPI / hotplug: Fix handle_root_bridge_removal()
  ACPI / hotplug: Refuse to hot-remove all objects with disabled hotplug
  ACPI / scan: Start matching drivers after trying scan handlers
  ACPI: Remove acpi_pci_slot_init() headers from internal.h
  ACPI / blacklist: fix name of ThinkPad Edge E530
  PowerCap: Fix build error with option -Werror=format-security
  ...

Conflicts:
	arch/arm/mach-omap2/opp.c
	drivers/Kconfig
	drivers/spi/spi.c

1 files changed, 356 insertions, 224 deletions

diff --git a/drivers/acpi/acpi_ipmi.c b/drivers/acpi/acpi_ipmi.c
index a6977e12d574..ac0f52f6df2b 100644
--- a/drivers/acpi/acpi_ipmi.c
+++ b/drivers/acpi/acpi_ipmi.c
@@ -1,8 +1,9 @@
 /*
  *  acpi_ipmi.c - ACPI IPMI opregion
  *
- *  Copyright (C) 2010 Intel Corporation
- *  Copyright (C) 2010 Zhao Yakui <yakui.zhao@intel.com>
+ *  Copyright (C) 2010, 2013 Intel Corporation
+ *    Author: Zhao Yakui <yakui.zhao@intel.com>
+ *            Lv Zheng <lv.zheng@intel.com>
  *
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  *
@@ -23,60 +24,58 @@
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  */
 
-#include <linux/kernel.h>
 #include <linux/module.h>
-#include <linux/init.h>
-#include <linux/types.h>
-#include <linux/delay.h>
-#include <linux/proc_fs.h>
-#include <linux/seq_file.h>
-#include <linux/interrupt.h>
-#include <linux/list.h>
-#include <linux/spinlock.h>
-#include <linux/io.h>
-#include <acpi/acpi_bus.h>
-#include <acpi/acpi_drivers.h>
+#include <linux/acpi.h>
 #include <linux/ipmi.h>
-#include <linux/device.h>
-#include <linux/pnp.h>
 #include <linux/spinlock.h>
 
 MODULE_AUTHOR("Zhao Yakui");
 MODULE_DESCRIPTION("ACPI IPMI Opregion driver");
 MODULE_LICENSE("GPL");
 
-#define IPMI_FLAGS_HANDLER_INSTALL	0
-
 #define ACPI_IPMI_OK			0
 #define ACPI_IPMI_TIMEOUT		0x10
 #define ACPI_IPMI_UNKNOWN		0x07
 /* the IPMI timeout is 5s */
-#define IPMI_TIMEOUT			(5 * HZ)
+#define IPMI_TIMEOUT			(5000)
+#define ACPI_IPMI_MAX_MSG_LENGTH	64
 
 struct acpi_ipmi_device {
 	/* the device list attached to driver_data.ipmi_devices */
 	struct list_head head;
+
 	/* the IPMI request message list */
 	struct list_head tx_msg_list;
-	spinlock_t	tx_msg_lock;
+
+	spinlock_t tx_msg_lock;
 	acpi_handle handle;
-	struct pnp_dev *pnp_dev;
-	ipmi_user_t	user_interface;
+	struct device *dev;
+	ipmi_user_t user_interface;
 	int ipmi_ifnum; /* IPMI interface number */
 	long curr_msgid;
-	unsigned long flags;
-	struct ipmi_smi_info smi_data;
+	bool dead;
+	struct kref kref;
 };
 
 struct ipmi_driver_data {
-	struct list_head	ipmi_devices;
-	struct ipmi_smi_watcher	bmc_events;
-	struct ipmi_user_hndl	ipmi_hndlrs;
-	struct mutex		ipmi_lock;
+	struct list_head ipmi_devices;
+	struct ipmi_smi_watcher bmc_events;
+	struct ipmi_user_hndl ipmi_hndlrs;
+	struct mutex ipmi_lock;
+
+	/*
+	 * NOTE: IPMI System Interface Selection
+	 * There is no system interface specified by the IPMI operation
+	 * region access.  We try to select one system interface with ACPI
+	 * handle set.  IPMI messages passed from the ACPI codes are sent
+	 * to this selected global IPMI system interface.
+	 */
+	struct acpi_ipmi_device *selected_smi;
 };
 
 struct acpi_ipmi_msg {
 	struct list_head head;
+
 	/*
 	 * General speaking the addr type should be SI_ADDR_TYPE. And
 	 * the addr channel should be BMC.
@@ -86,30 +85,31 @@ struct acpi_ipmi_msg {
 	 */
 	struct ipmi_addr addr;
 	long tx_msgid;
+
 	/* it is used to track whether the IPMI message is finished */
 	struct completion tx_complete;
+
 	struct kernel_ipmi_msg tx_message;
-	int	msg_done;
-	/* tx data . And copy it from ACPI object buffer */
-	u8	tx_data[64];
-	int	tx_len;
-	u8	rx_data[64];
-	int	rx_len;
+	int msg_done;
+
+	/* tx/rx data . And copy it from/to ACPI object buffer */
+	u8 data[ACPI_IPMI_MAX_MSG_LENGTH];
+	u8 rx_len;
+
 	struct acpi_ipmi_device *device;
+	struct kref kref;
 };
 
 /* IPMI request/response buffer per ACPI 4.0, sec 5.5.2.4.3.2 */
 struct acpi_ipmi_buffer {
 	u8 status;
 	u8 length;
-	u8 data[64];
+	u8 data[ACPI_IPMI_MAX_MSG_LENGTH];
 };
 
 static void ipmi_register_bmc(int iface, struct device *dev);
 static void ipmi_bmc_gone(int iface);
 static void ipmi_msg_handler(struct ipmi_recv_msg *msg, void *user_msg_data);
-static void acpi_add_ipmi_device(struct acpi_ipmi_device *ipmi_device);
-static void acpi_remove_ipmi_device(struct acpi_ipmi_device *ipmi_device);
 
 static struct ipmi_driver_data driver_data = {
 	.ipmi_devices = LIST_HEAD_INIT(driver_data.ipmi_devices),
@@ -121,29 +121,142 @@ static struct ipmi_driver_data driver_data = {
 	.ipmi_hndlrs = {
 		.ipmi_recv_hndl = ipmi_msg_handler,
 	},
+	.ipmi_lock = __MUTEX_INITIALIZER(driver_data.ipmi_lock)
 };
 
-static struct acpi_ipmi_msg *acpi_alloc_ipmi_msg(struct acpi_ipmi_device *ipmi)
+static struct acpi_ipmi_device *
+ipmi_dev_alloc(int iface, struct device *dev, acpi_handle handle)
+{
+	struct acpi_ipmi_device *ipmi_device;
+	int err;
+	ipmi_user_t user;
+
+	ipmi_device = kzalloc(sizeof(*ipmi_device), GFP_KERNEL);
+	if (!ipmi_device)
+		return NULL;
+
+	kref_init(&ipmi_device->kref);
+	INIT_LIST_HEAD(&ipmi_device->head);
+	INIT_LIST_HEAD(&ipmi_device->tx_msg_list);
+	spin_lock_init(&ipmi_device->tx_msg_lock);
+	ipmi_device->handle = handle;
+	ipmi_device->dev = get_device(dev);
+	ipmi_device->ipmi_ifnum = iface;
+
+	err = ipmi_create_user(iface, &driver_data.ipmi_hndlrs,
+			       ipmi_device, &user);
+	if (err) {
+		put_device(dev);
+		kfree(ipmi_device);
+		return NULL;
+	}
+	ipmi_device->user_interface = user;
+
+	return ipmi_device;
+}
+
+static void ipmi_dev_release(struct acpi_ipmi_device *ipmi_device)
+{
+	ipmi_destroy_user(ipmi_device->user_interface);
+	put_device(ipmi_device->dev);
+	kfree(ipmi_device);
+}
+
+static void ipmi_dev_release_kref(struct kref *kref)
+{
+	struct acpi_ipmi_device *ipmi =
+		container_of(kref, struct acpi_ipmi_device, kref);
+
+	ipmi_dev_release(ipmi);
+}
+
+static void __ipmi_dev_kill(struct acpi_ipmi_device *ipmi_device)
+{
+	list_del(&ipmi_device->head);
+	if (driver_data.selected_smi == ipmi_device)
+		driver_data.selected_smi = NULL;
+
+	/*
+	 * Always setting dead flag after deleting from the list or
+	 * list_for_each_entry() codes must get changed.
+	 */
+	ipmi_device->dead = true;
+}
+
+static struct acpi_ipmi_device *acpi_ipmi_dev_get(void)
+{
+	struct acpi_ipmi_device *ipmi_device = NULL;
+
+	mutex_lock(&driver_data.ipmi_lock);
+	if (driver_data.selected_smi) {
+		ipmi_device = driver_data.selected_smi;
+		kref_get(&ipmi_device->kref);
+	}
+	mutex_unlock(&driver_data.ipmi_lock);
+
+	return ipmi_device;
+}
+
+static void acpi_ipmi_dev_put(struct acpi_ipmi_device *ipmi_device)
+{
+	kref_put(&ipmi_device->kref, ipmi_dev_release_kref);
+}
+
+static struct acpi_ipmi_msg *ipmi_msg_alloc(void)
 {
+	struct acpi_ipmi_device *ipmi;
 	struct acpi_ipmi_msg *ipmi_msg;
-	struct pnp_dev *pnp_dev = ipmi->pnp_dev;
+
+	ipmi = acpi_ipmi_dev_get();
+	if (!ipmi)
+		return NULL;
 
 	ipmi_msg = kzalloc(sizeof(struct acpi_ipmi_msg), GFP_KERNEL);
-	if (!ipmi_msg)	{
-		dev_warn(&pnp_dev->dev, "Can't allocate memory for ipmi_msg\n");
+	if (!ipmi_msg) {
+		acpi_ipmi_dev_put(ipmi);
 		return NULL;
 	}
+
+	kref_init(&ipmi_msg->kref);
 	init_completion(&ipmi_msg->tx_complete);
 	INIT_LIST_HEAD(&ipmi_msg->head);
 	ipmi_msg->device = ipmi;
+	ipmi_msg->msg_done = ACPI_IPMI_UNKNOWN;
+
 	return ipmi_msg;
 }
 
-#define		IPMI_OP_RGN_NETFN(offset)	((offset >> 8) & 0xff)
-#define		IPMI_OP_RGN_CMD(offset)		(offset & 0xff)
-static void acpi_format_ipmi_msg(struct acpi_ipmi_msg *tx_msg,
-				acpi_physical_address address,
-				acpi_integer *value)
+static void ipmi_msg_release(struct acpi_ipmi_msg *tx_msg)
+{
+	acpi_ipmi_dev_put(tx_msg->device);
+	kfree(tx_msg);
+}
+
+static void ipmi_msg_release_kref(struct kref *kref)
+{
+	struct acpi_ipmi_msg *tx_msg =
+		container_of(kref, struct acpi_ipmi_msg, kref);
+
+	ipmi_msg_release(tx_msg);
+}
+
+static struct acpi_ipmi_msg *acpi_ipmi_msg_get(struct acpi_ipmi_msg *tx_msg)
+{
+	kref_get(&tx_msg->kref);
+
+	return tx_msg;
+}
+
+static void acpi_ipmi_msg_put(struct acpi_ipmi_msg *tx_msg)
+{
+	kref_put(&tx_msg->kref, ipmi_msg_release_kref);
+}
+
+#define IPMI_OP_RGN_NETFN(offset)	((offset >> 8) & 0xff)
+#define IPMI_OP_RGN_CMD(offset)		(offset & 0xff)
+static int acpi_format_ipmi_request(struct acpi_ipmi_msg *tx_msg,
+				    acpi_physical_address address,
+				    acpi_integer *value)
 {
 	struct kernel_ipmi_msg *msg;
 	struct acpi_ipmi_buffer *buffer;
@@ -151,21 +264,31 @@ static void acpi_format_ipmi_msg(struct acpi_ipmi_msg *tx_msg,
 	unsigned long flags;
 
 	msg = &tx_msg->tx_message;
+
 	/*
 	 * IPMI network function and command are encoded in the address
 	 * within the IPMI OpRegion; see ACPI 4.0, sec 5.5.2.4.3.
 	 */
 	msg->netfn = IPMI_OP_RGN_NETFN(address);
 	msg->cmd = IPMI_OP_RGN_CMD(address);
-	msg->data = tx_msg->tx_data;
+	msg->data = tx_msg->data;
+
 	/*
 	 * value is the parameter passed by the IPMI opregion space handler.
 	 * It points to the IPMI request message buffer
 	 */
 	buffer = (struct acpi_ipmi_buffer *)value;
+
 	/* copy the tx message data */
+	if (buffer->length > ACPI_IPMI_MAX_MSG_LENGTH) {
+		dev_WARN_ONCE(tx_msg->device->dev, true,
+			      "Unexpected request (msg len %d).\n",
+			      buffer->length);
+		return -EINVAL;
+	}
 	msg->data_len = buffer->length;
-	memcpy(tx_msg->tx_data, buffer->data, msg->data_len);
+	memcpy(tx_msg->data, buffer->data, msg->data_len);
+
 	/*
 	 * now the default type is SYSTEM_INTERFACE and channel type is BMC.
 	 * If the netfn is APP_REQUEST and the cmd is SEND_MESSAGE,
@@ -179,14 +302,17 @@ static void acpi_format_ipmi_msg(struct acpi_ipmi_msg *tx_msg,
 
 	/* Get the msgid */
 	device = tx_msg->device;
+
 	spin_lock_irqsave(&device->tx_msg_lock, flags);
 	device->curr_msgid++;
 	tx_msg->tx_msgid = device->curr_msgid;
 	spin_unlock_irqrestore(&device->tx_msg_lock, flags);
+
+	return 0;
 }
 
 static void acpi_format_ipmi_response(struct acpi_ipmi_msg *msg,
-		acpi_integer *value, int rem_time)
+				      acpi_integer *value)
 {
 	struct acpi_ipmi_buffer *buffer;
 
@@ -195,110 +321,158 @@ static void acpi_format_ipmi_response(struct acpi_ipmi_msg *msg,
 	 * IPMI message returned by IPMI command.
 	 */
 	buffer = (struct acpi_ipmi_buffer *)value;
-	if (!rem_time && !msg->msg_done) {
-		buffer->status = ACPI_IPMI_TIMEOUT;
-		return;
-	}
+
 	/*
-	 * If the flag of msg_done is not set or the recv length is zero, it
-	 * means that the IPMI command is not executed correctly.
-	 * The status code will be ACPI_IPMI_UNKNOWN.
+	 * If the flag of msg_done is not set, it means that the IPMI command is
+	 * not executed correctly.
 	 */
-	if (!msg->msg_done || !msg->rx_len) {
-		buffer->status = ACPI_IPMI_UNKNOWN;
+	buffer->status = msg->msg_done;
+	if (msg->msg_done != ACPI_IPMI_OK)
 		return;
-	}
+
 	/*
 	 * If the IPMI response message is obtained correctly, the status code
 	 * will be ACPI_IPMI_OK
 	 */
-	buffer->status = ACPI_IPMI_OK;
 	buffer->length = msg->rx_len;
-	memcpy(buffer->data, msg->rx_data, msg->rx_len);
+	memcpy(buffer->data, msg->data, msg->rx_len);
 }
 
 static void ipmi_flush_tx_msg(struct acpi_ipmi_device *ipmi)
 {
-	struct acpi_ipmi_msg *tx_msg, *temp;
-	int count = HZ / 10;
-	struct pnp_dev *pnp_dev = ipmi->pnp_dev;
+	struct acpi_ipmi_msg *tx_msg;
+	unsigned long flags;
+
+	/*
+	 * NOTE: On-going ipmi_recv_msg
+	 * ipmi_msg_handler() may still be invoked by ipmi_si after
+	 * flushing.  But it is safe to do a fast flushing on module_exit()
+	 * without waiting for all ipmi_recv_msg(s) to complete from
+	 * ipmi_msg_handler() as it is ensured by ipmi_si that all
+	 * ipmi_recv_msg(s) are freed after invoking ipmi_destroy_user().
+	 */
+	spin_lock_irqsave(&ipmi->tx_msg_lock, flags);
+	while (!list_empty(&ipmi->tx_msg_list)) {
+		tx_msg = list_first_entry(&ipmi->tx_msg_list,
+					  struct acpi_ipmi_msg,
+					  head);
+		list_del(&tx_msg->head);
+		spin_unlock_irqrestore(&ipmi->tx_msg_lock, flags);
 
-	list_for_each_entry_safe(tx_msg, temp, &ipmi->tx_msg_list, head) {
 		/* wake up the sleep thread on the Tx msg */
 		complete(&tx_msg->tx_complete);
+		acpi_ipmi_msg_put(tx_msg);
+		spin_lock_irqsave(&ipmi->tx_msg_lock, flags);
 	}
+	spin_unlock_irqrestore(&ipmi->tx_msg_lock, flags);
+}
+
+static void ipmi_cancel_tx_msg(struct acpi_ipmi_device *ipmi,
+			       struct acpi_ipmi_msg *msg)
+{
+	struct acpi_ipmi_msg *tx_msg, *temp;
+	bool msg_found = false;
+	unsigned long flags;
 
-	/* wait for about 100ms to flush the tx message list */
-	while (count--) {
-		if (list_empty(&ipmi->tx_msg_list))
+	spin_lock_irqsave(&ipmi->tx_msg_lock, flags);
+	list_for_each_entry_safe(tx_msg, temp, &ipmi->tx_msg_list, head) {
+		if (msg == tx_msg) {
+			msg_found = true;
+			list_del(&tx_msg->head);
 			break;
-		schedule_timeout(1);
+		}
 	}
-	if (!list_empty(&ipmi->tx_msg_list))
-		dev_warn(&pnp_dev->dev, "tx msg list is not NULL\n");
+	spin_unlock_irqrestore(&ipmi->tx_msg_lock, flags);
+
+	if (msg_found)
+		acpi_ipmi_msg_put(tx_msg);
 }
 
 static void ipmi_msg_handler(struct ipmi_recv_msg *msg, void *user_msg_data)
 {
 	struct acpi_ipmi_device *ipmi_device = user_msg_data;
-	int msg_found = 0;
-	struct acpi_ipmi_msg *tx_msg;
-	struct pnp_dev *pnp_dev = ipmi_device->pnp_dev;
+	bool msg_found = false;
+	struct acpi_ipmi_msg *tx_msg, *temp;
+	struct device *dev = ipmi_device->dev;
 	unsigned long flags;
 
 	if (msg->user != ipmi_device->user_interface) {
-		dev_warn(&pnp_dev->dev, "Unexpected response is returned. "
-			"returned user %p, expected user %p\n",
-			msg->user, ipmi_device->user_interface);
-		ipmi_free_recv_msg(msg);
-		return;
+		dev_warn(dev,
+			 "Unexpected response is returned. returned user %p, expected user %p\n",
+			 msg->user, ipmi_device->user_interface);
+		goto out_msg;
 	}
+
 	spin_lock_irqsave(&ipmi_device->tx_msg_lock, flags);
-	list_for_each_entry(tx_msg, &ipmi_device->tx_msg_list, head) {
+	list_for_each_entry_safe(tx_msg, temp, &ipmi_device->tx_msg_list, head) {
 		if (msg->msgid == tx_msg->tx_msgid) {
-			msg_found = 1;
+			msg_found = true;
+			list_del(&tx_msg->head);
 			break;
 		}
 	}
-
 	spin_unlock_irqrestore(&ipmi_device->tx_msg_lock, flags);
+
 	if (!msg_found) {
-		dev_warn(&pnp_dev->dev, "Unexpected response (msg id %ld) is "
-			"returned.\n", msg->msgid);
-		ipmi_free_recv_msg(msg);
-		return;
+		dev_warn(dev,
+			 "Unexpected response (msg id %ld) is returned.\n",
+			 msg->msgid);
+		goto out_msg;
 	}
 
-	if (msg->msg.data_len) {
-		/* copy the response data to Rx_data buffer */
-		memcpy(tx_msg->rx_data, msg->msg_data, msg->msg.data_len);
-		tx_msg->rx_len = msg->msg.data_len;
-		tx_msg->msg_done = 1;
+	/* copy the response data to Rx_data buffer */
+	if (msg->msg.data_len > ACPI_IPMI_MAX_MSG_LENGTH) {
+		dev_WARN_ONCE(dev, true,
+			      "Unexpected response (msg len %d).\n",
+			      msg->msg.data_len);
+		goto out_comp;
 	}
+
+	/* response msg is an error msg */
+	msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
+	if (msg->recv_type == IPMI_RESPONSE_RECV_TYPE &&
+	    msg->msg.data_len == 1) {
+		if (msg->msg.data[0] == IPMI_TIMEOUT_COMPLETION_CODE) {
+			dev_WARN_ONCE(dev, true,
+				      "Unexpected response (timeout).\n");
+			tx_msg->msg_done = ACPI_IPMI_TIMEOUT;
+		}
+		goto out_comp;
+	}
+
+	tx_msg->rx_len = msg->msg.data_len;
+	memcpy(tx_msg->data, msg->msg.data, tx_msg->rx_len);
+	tx_msg->msg_done = ACPI_IPMI_OK;
+
+out_comp:
 	complete(&tx_msg->tx_complete);
+	acpi_ipmi_msg_put(tx_msg);
+out_msg:
 	ipmi_free_recv_msg(msg);
-};
+}
 
 static void ipmi_register_bmc(int iface, struct device *dev)
 {
 	struct acpi_ipmi_device *ipmi_device, *temp;
-	struct pnp_dev *pnp_dev;
-	ipmi_user_t		user;
 	int err;
 	struct ipmi_smi_info smi_data;
 	acpi_handle handle;
 
 	err = ipmi_get_smi_info(iface, &smi_data);
-
 	if (err)
 		return;
 
-	if (smi_data.addr_src != SI_ACPI) {
-		put_device(smi_data.dev);
-		return;
-	}
-
+	if (smi_data.addr_src != SI_ACPI)
+		goto err_ref;
 	handle = smi_data.addr_info.acpi_info.acpi_handle;
+	if (!handle)
+		goto err_ref;
+
+	ipmi_device = ipmi_dev_alloc(iface, smi_data.dev, handle);
+	if (!ipmi_device) {
+		dev_warn(smi_data.dev, "Can't create IPMI user interface\n");
+		goto err_ref;
+	}
 
 	mutex_lock(&driver_data.ipmi_lock);
 	list_for_each_entry(temp, &driver_data.ipmi_devices, head) {
@@ -307,34 +481,20 @@ static void ipmi_register_bmc(int iface, struct device *dev)
 		 * to the device list, don't add it again.
 		 */
 		if (temp->handle == handle)
-			goto out;
+			goto err_lock;
 	}
-
-	ipmi_device = kzalloc(sizeof(*ipmi_device), GFP_KERNEL);
-
-	if (!ipmi_device)
-		goto out;
-
-	pnp_dev = to_pnp_dev(smi_data.dev);
-	ipmi_device->handle = handle;
-	ipmi_device->pnp_dev = pnp_dev;
-
-	err = ipmi_create_user(iface, &driver_data.ipmi_hndlrs,
-					ipmi_device, &user);
-	if (err) {
-		dev_warn(&pnp_dev->dev, "Can't create IPMI user interface\n");
-		kfree(ipmi_device);
-		goto out;
-	}
-	acpi_add_ipmi_device(ipmi_device);
-	ipmi_device->user_interface = user;
-	ipmi_device->ipmi_ifnum = iface;
+	if (!driver_data.selected_smi)
+		driver_data.selected_smi = ipmi_device;
+	list_add_tail(&ipmi_device->head, &driver_data.ipmi_devices);
 	mutex_unlock(&driver_data.ipmi_lock);
-	memcpy(&ipmi_device->smi_data, &smi_data, sizeof(struct ipmi_smi_info));
+
+	put_device(smi_data.dev);
 	return;
 
-out:
+err_lock:
 	mutex_unlock(&driver_data.ipmi_lock);
+	ipmi_dev_release(ipmi_device);
+err_ref:
 	put_device(smi_data.dev);
 	return;
 }
@@ -342,23 +502,29 @@ out:
 static void ipmi_bmc_gone(int iface)
 {
 	struct acpi_ipmi_device *ipmi_device, *temp;
+	bool dev_found = false;
 
 	mutex_lock(&driver_data.ipmi_lock);
 	list_for_each_entry_safe(ipmi_device, temp,
-				&driver_data.ipmi_devices, head) {
-		if (ipmi_device->ipmi_ifnum != iface)
-			continue;
-
-		acpi_remove_ipmi_device(ipmi_device);
-		put_device(ipmi_device->smi_data.dev);
-		kfree(ipmi_device);
-		break;
+				 &driver_data.ipmi_devices, head) {
+		if (ipmi_device->ipmi_ifnum != iface) {
+			dev_found = true;
+			__ipmi_dev_kill(ipmi_device);
+			break;
+		}
 	}
+	if (!driver_data.selected_smi)
+		driver_data.selected_smi = list_first_entry_or_null(
+					&driver_data.ipmi_devices,
+					struct acpi_ipmi_device, head);
 	mutex_unlock(&driver_data.ipmi_lock);
+
+	if (dev_found) {
+		ipmi_flush_tx_msg(ipmi_device);
+		acpi_ipmi_dev_put(ipmi_device);
+	}
 }
-/* --------------------------------------------------------------------------
- *			Address Space Management
- * -------------------------------------------------------------------------- */
+
 /*
  * This is the IPMI opregion space handler.
  * @function: indicates the read/write. In fact as the IPMI message is driven
@@ -371,17 +537,17 @@ static void ipmi_bmc_gone(int iface)
  *	     the response IPMI message returned by IPMI command.
  * @handler_context: IPMI device context.
  */
-
 static acpi_status
 acpi_ipmi_space_handler(u32 function, acpi_physical_address address,
-		      u32 bits, acpi_integer *value,
-		      void *handler_context, void *region_context)
+			u32 bits, acpi_integer *value,
+			void *handler_context, void *region_context)
 {
 	struct acpi_ipmi_msg *tx_msg;
-	struct acpi_ipmi_device *ipmi_device = handler_context;
-	int err, rem_time;
+	struct acpi_ipmi_device *ipmi_device;
+	int err;
 	acpi_status status;
 	unsigned long flags;
+
 	/*
 	 * IPMI opregion message.
 	 * IPMI message is firstly written to the BMC and system software
@@ -391,118 +557,75 @@ acpi_ipmi_space_handler(u32 function, acpi_physical_address address,
 	if ((function & ACPI_IO_MASK) == ACPI_READ)
 		return AE_TYPE;
 
-	if (!ipmi_device->user_interface)
+	tx_msg = ipmi_msg_alloc();
+	if (!tx_msg)
 		return AE_NOT_EXIST;
+	ipmi_device = tx_msg->device;
 
-	tx_msg = acpi_alloc_ipmi_msg(ipmi_device);
-	if (!tx_msg)
-		return AE_NO_MEMORY;
+	if (acpi_format_ipmi_request(tx_msg, address, value) != 0) {
+		ipmi_msg_release(tx_msg);
+		return AE_TYPE;
+	}
 
-	acpi_format_ipmi_msg(tx_msg, address, value);
+	acpi_ipmi_msg_get(tx_msg);
+	mutex_lock(&driver_data.ipmi_lock);
+	/* Do not add a tx_msg that can not be flushed. */
+	if (ipmi_device->dead) {
+		mutex_unlock(&driver_data.ipmi_lock);
+		ipmi_msg_release(tx_msg);
+		return AE_NOT_EXIST;
+	}
 	spin_lock_irqsave(&ipmi_device->tx_msg_lock, flags);
 	list_add_tail(&tx_msg->head, &ipmi_device->tx_msg_list);
 	spin_unlock_irqrestore(&ipmi_device->tx_msg_lock, flags);
+	mutex_unlock(&driver_data.ipmi_lock);
+
 	err = ipmi_request_settime(ipmi_device->user_interface,
-					&tx_msg->addr,
-					tx_msg->tx_msgid,
-					&tx_msg->tx_message,
-					NULL, 0, 0, 0);
+				   &tx_msg->addr,
+				   tx_msg->tx_msgid,
+				   &tx_msg->tx_message,
+				   NULL, 0, 0, IPMI_TIMEOUT);
 	if (err) {
 		status = AE_ERROR;
-		goto end_label;
+		goto out_msg;
 	}
-	rem_time = wait_for_completion_timeout(&tx_msg->tx_complete,
-					IPMI_TIMEOUT);
-	acpi_format_ipmi_response(tx_msg, value, rem_time);
+	wait_for_completion(&tx_msg->tx_complete);
+
+	acpi_format_ipmi_response(tx_msg, value);
 	status = AE_OK;
 
-end_label:
-	spin_lock_irqsave(&ipmi_device->tx_msg_lock, flags);
-	list_del(&tx_msg->head);
-	spin_unlock_irqrestore(&ipmi_device->tx_msg_lock, flags);
-	kfree(tx_msg);
+out_msg:
+	ipmi_cancel_tx_msg(ipmi_device, tx_msg);
+	acpi_ipmi_msg_put(tx_msg);
 	return status;
 }
 
-static void ipmi_remove_space_handler(struct acpi_ipmi_device *ipmi)
-{
-	if (!test_bit(IPMI_FLAGS_HANDLER_INSTALL, &ipmi->flags))
-		return;
-
-	acpi_remove_address_space_handler(ipmi->handle,
-				ACPI_ADR_SPACE_IPMI, &acpi_ipmi_space_handler);
-
-	clear_bit(IPMI_FLAGS_HANDLER_INSTALL, &ipmi->flags);
-}
-
-static int ipmi_install_space_handler(struct acpi_ipmi_device *ipmi)
+static int __init acpi_ipmi_init(void)
 {
+	int result;
 	acpi_status status;
 
-	if (test_bit(IPMI_FLAGS_HANDLER_INSTALL, &ipmi->flags))
+	if (acpi_disabled)
 		return 0;
 
-	status = acpi_install_address_space_handler(ipmi->handle,
+	status = acpi_install_address_space_handler(ACPI_ROOT_OBJECT,
 						    ACPI_ADR_SPACE_IPMI,
 						    &acpi_ipmi_space_handler,
-						    NULL, ipmi);
+						    NULL, NULL);
 	if (ACPI_FAILURE(status)) {
-		struct pnp_dev *pnp_dev = ipmi->pnp_dev;
-		dev_warn(&pnp_dev->dev, "Can't register IPMI opregion space "
-			"handle\n");
+		pr_warn("Can't register IPMI opregion space handle\n");
 		return -EINVAL;
 	}
-	set_bit(IPMI_FLAGS_HANDLER_INSTALL, &ipmi->flags);
-	return 0;
-}
-
-static void acpi_add_ipmi_device(struct acpi_ipmi_device *ipmi_device)
-{
-
-	INIT_LIST_HEAD(&ipmi_device->head);
-
-	spin_lock_init(&ipmi_device->tx_msg_lock);
-	INIT_LIST_HEAD(&ipmi_device->tx_msg_list);
-	ipmi_install_space_handler(ipmi_device);
-
-	list_add_tail(&ipmi_device->head, &driver_data.ipmi_devices);
-}
-
-static void acpi_remove_ipmi_device(struct acpi_ipmi_device *ipmi_device)
-{
-	/*
-	 * If the IPMI user interface is created, it should be
-	 * destroyed.
-	 */
-	if (ipmi_device->user_interface) {
-		ipmi_destroy_user(ipmi_device->user_interface);
-		ipmi_device->user_interface = NULL;
-	}
-	/* flush the Tx_msg list */
-	if (!list_empty(&ipmi_device->tx_msg_list))
-		ipmi_flush_tx_msg(ipmi_device);
-
-	list_del(&ipmi_device->head);
-	ipmi_remove_space_handler(ipmi_device);
-}
-
-static int __init acpi_ipmi_init(void)
-{
-	int result = 0;
-
-	if (acpi_disabled)
-		return result;
-
-	mutex_init(&driver_data.ipmi_lock);
-
 	result = ipmi_smi_watcher_register(&driver_data.bmc_events);
+	if (result)
+		pr_err("Can't register IPMI system interface watcher\n");
 
 	return result;
 }
 
 static void __exit acpi_ipmi_exit(void)
 {
-	struct acpi_ipmi_device *ipmi_device, *temp;
+	struct acpi_ipmi_device *ipmi_device;
 
 	if (acpi_disabled)
 		return;
@@ -516,13 +639,22 @@ static void __exit acpi_ipmi_exit(void)
 	 * handler and free it.
 	 */
 	mutex_lock(&driver_data.ipmi_lock);
-	list_for_each_entry_safe(ipmi_device, temp,
-				&driver_data.ipmi_devices, head) {
-		acpi_remove_ipmi_device(ipmi_device);
-		put_device(ipmi_device->smi_data.dev);
-		kfree(ipmi_device);
+	while (!list_empty(&driver_data.ipmi_devices)) {
+		ipmi_device = list_first_entry(&driver_data.ipmi_devices,
+					       struct acpi_ipmi_device,
+					       head);
+		__ipmi_dev_kill(ipmi_device);
+		mutex_unlock(&driver_data.ipmi_lock);
+
+		ipmi_flush_tx_msg(ipmi_device);
+		acpi_ipmi_dev_put(ipmi_device);
+
+		mutex_lock(&driver_data.ipmi_lock);
 	}
 	mutex_unlock(&driver_data.ipmi_lock);
+	acpi_remove_address_space_handler(ACPI_ROOT_OBJECT,
+					  ACPI_ADR_SPACE_IPMI,
+					  &acpi_ipmi_space_handler);
 }
 
 module_init(acpi_ipmi_init);