Merge tag 'for-linus-5.4-1' of git://github.com/cminyard/linux-ipmi

Pull IPMI updates from Corey Minyard:
 "A few minor fixes and some cosmetic changes.

  Nothing big here, but some minor things that people have found and
  some minor reworks for names and include files"

* tag 'for-linus-5.4-1' of git://github.com/cminyard/linux-ipmi:
  ipmi_si_intf: Fix race in timer shutdown handling
  ipmi: move message error checking to avoid deadlock
  ipmi_ssif: avoid registering duplicate ssif interface
  ipmi: Free receive messages when in an oops
  ipmi_si: Only schedule continuously in the thread in maintenance mode
  ipmi_si: Remove ipmi_ from the device attr names
  ipmi_si: Convert device attr permissions to octal
  ipmi_si: Rework some include files
  ipmi_si: Convert timespec64 to timespec

drivers/char/ipmi/ipmi_dmi.c

@@ -12,7 +12,6 @@
 #include <linux/dmi.h>
 #include <linux/platform_device.h>
 #include <linux/property.h>
-#include "ipmi_si_sm.h"
 #include "ipmi_dmi.h"
 #include "ipmi_plat_data.h"
 

drivers/char/ipmi/ipmi_dmi.h

@@ -2,6 +2,7 @@
 /*
  * DMI defines for use by IPMI
  */
+#include "ipmi_si.h"
 
 #ifdef CONFIG_IPMI_DMI_DECODE
 int ipmi_dmi_get_slave_addr(enum si_type si_type, unsigned int space,

drivers/char/ipmi/ipmi_msghandler.c

@@ -904,12 +904,14 @@ static int deliver_response(struct ipmi_smi *intf, struct ipmi_recv_msg *msg)
 			rv = -EINVAL;
 		}
 		ipmi_free_recv_msg(msg);
-	} else if (!oops_in_progress) {
+	} else if (oops_in_progress) {
 		/*
 		 * If we are running in the panic context, calling the
 		 * receive handler doesn't much meaning and has a deadlock
 		 * risk.  At this moment, simply skip it in that case.
 		 */
+		ipmi_free_recv_msg(msg);
+	} else {
 		int index;
 		struct ipmi_user *user = acquire_ipmi_user(msg->user, &index);
 
@@ -2220,6 +2222,7 @@ static int i_ipmi_request(struct ipmi_user     *user,
 	else {
 		smi_msg = ipmi_alloc_smi_msg();
 		if (smi_msg == NULL) {
+			if (!supplied_recv)
 				ipmi_free_recv_msg(recv_msg);
 			rv = -ENOMEM;
 			goto out;
@@ -4215,7 +4218,53 @@ static int handle_one_recv_msg(struct ipmi_smi *intf,
 	int chan;
 
 	ipmi_debug_msg("Recv:", msg->rsp, msg->rsp_size);
-	if (msg->rsp_size < 2) {
+
+	if ((msg->data_size >= 2)
+	    && (msg->data[0] == (IPMI_NETFN_APP_REQUEST << 2))
+	    && (msg->data[1] == IPMI_SEND_MSG_CMD)
+	    && (msg->user_data == NULL)) {
+
+		if (intf->in_shutdown)
+			goto free_msg;
+
+		/*
+		 * This is the local response to a command send, start
+		 * the timer for these.  The user_data will not be
+		 * NULL if this is a response send, and we will let
+		 * response sends just go through.
+		 */
+
+		/*
+		 * Check for errors, if we get certain errors (ones
+		 * that mean basically we can try again later), we
+		 * ignore them and start the timer.  Otherwise we
+		 * report the error immediately.
+		 */
+		if ((msg->rsp_size >= 3) && (msg->rsp[2] != 0)
+		    && (msg->rsp[2] != IPMI_NODE_BUSY_ERR)
+		    && (msg->rsp[2] != IPMI_LOST_ARBITRATION_ERR)
+		    && (msg->rsp[2] != IPMI_BUS_ERR)
+		    && (msg->rsp[2] != IPMI_NAK_ON_WRITE_ERR)) {
+			int ch = msg->rsp[3] & 0xf;
+			struct ipmi_channel *chans;
+
+			/* Got an error sending the message, handle it. */
+
+			chans = READ_ONCE(intf->channel_list)->c;
+			if ((chans[ch].medium == IPMI_CHANNEL_MEDIUM_8023LAN)
+			    || (chans[ch].medium == IPMI_CHANNEL_MEDIUM_ASYNC))
+				ipmi_inc_stat(intf, sent_lan_command_errs);
+			else
+				ipmi_inc_stat(intf, sent_ipmb_command_errs);
+			intf_err_seq(intf, msg->msgid, msg->rsp[2]);
+		} else
+			/* The message was sent, start the timer. */
+			intf_start_seq_timer(intf, msg->msgid);
+free_msg:
+		requeue = 0;
+		goto out;
+
+	} else if (msg->rsp_size < 2) {
 		/* Message is too small to be correct. */
 		dev_warn(intf->si_dev,
 			 "BMC returned too small a message for netfn %x cmd %x, got %d bytes\n",
@@ -4472,51 +4521,6 @@ void ipmi_smi_msg_received(struct ipmi_smi *intf,
 	unsigned long flags = 0; /* keep us warning-free. */
 	int run_to_completion = intf->run_to_completion;
 
-	if ((msg->data_size >= 2)
-	    && (msg->data[0] == (IPMI_NETFN_APP_REQUEST << 2))
-	    && (msg->data[1] == IPMI_SEND_MSG_CMD)
-	    && (msg->user_data == NULL)) {
-
-		if (intf->in_shutdown)
-			goto free_msg;
-
-		/*
-		 * This is the local response to a command send, start
-		 * the timer for these.  The user_data will not be
-		 * NULL if this is a response send, and we will let
-		 * response sends just go through.
-		 */
-
-		/*
-		 * Check for errors, if we get certain errors (ones
-		 * that mean basically we can try again later), we
-		 * ignore them and start the timer.  Otherwise we
-		 * report the error immediately.
-		 */
-		if ((msg->rsp_size >= 3) && (msg->rsp[2] != 0)
-		    && (msg->rsp[2] != IPMI_NODE_BUSY_ERR)
-		    && (msg->rsp[2] != IPMI_LOST_ARBITRATION_ERR)
-		    && (msg->rsp[2] != IPMI_BUS_ERR)
-		    && (msg->rsp[2] != IPMI_NAK_ON_WRITE_ERR)) {
-			int ch = msg->rsp[3] & 0xf;
-			struct ipmi_channel *chans;
-
-			/* Got an error sending the message, handle it. */
-
-			chans = READ_ONCE(intf->channel_list)->c;
-			if ((chans[ch].medium == IPMI_CHANNEL_MEDIUM_8023LAN)
-			    || (chans[ch].medium == IPMI_CHANNEL_MEDIUM_ASYNC))
-				ipmi_inc_stat(intf, sent_lan_command_errs);
-			else
-				ipmi_inc_stat(intf, sent_ipmb_command_errs);
-			intf_err_seq(intf, msg->msgid, msg->rsp[2]);
-		} else
-			/* The message was sent, start the timer. */
-			intf_start_seq_timer(intf, msg->msgid);
-
-free_msg:
-		ipmi_free_smi_msg(msg);
-	} else {
 	/*
 	 * To preserve message order, we keep a queue and deliver from
 	 * a tasklet.
@@ -4527,7 +4531,6 @@ void ipmi_smi_msg_received(struct ipmi_smi *intf,
 	if (!run_to_completion)
 		spin_unlock_irqrestore(&intf->waiting_rcv_msgs_lock,
 				       flags);
-	}
 
 	if (!run_to_completion)
 		spin_lock_irqsave(&intf->xmit_msgs_lock, flags);

drivers/char/ipmi/ipmi_si.h

@@ -6,14 +6,65 @@
  * etc) to the base ipmi system interface code.
  */
 
+#ifndef __IPMI_SI_H__
+#define __IPMI_SI_H__
+
+#include <linux/ipmi.h>
 #include <linux/interrupt.h>
 #include <linux/platform_device.h>
-#include "ipmi_si_sm.h"
+
+#define SI_DEVICE_NAME "ipmi_si"
 
 #define DEFAULT_REGSPACING	1
 #define DEFAULT_REGSIZE		1
 
-#define DEVICE_NAME "ipmi_si"
+enum si_type {
+	SI_TYPE_INVALID, SI_KCS, SI_SMIC, SI_BT
+};
+
+enum ipmi_addr_space {
+	IPMI_IO_ADDR_SPACE, IPMI_MEM_ADDR_SPACE
+};
+
+/*
+ * The structure for doing I/O in the state machine.  The state
+ * machine doesn't have the actual I/O routines, they are done through
+ * this interface.
+ */
+struct si_sm_io {
+	unsigned char (*inputb)(const struct si_sm_io *io, unsigned int offset);
+	void (*outputb)(const struct si_sm_io *io,
+			unsigned int  offset,
+			unsigned char b);
+
+	/*
+	 * Generic info used by the actual handling routines, the
+	 * state machine shouldn't touch these.
+	 */
+	void __iomem *addr;
+	unsigned int regspacing;
+	unsigned int regsize;
+	unsigned int regshift;
+	enum ipmi_addr_space addr_space;
+	unsigned long addr_data;
+	enum ipmi_addr_src addr_source; /* ACPI, PCI, SMBIOS, hardcode, etc. */
+	void (*addr_source_cleanup)(struct si_sm_io *io);
+	void *addr_source_data;
+	union ipmi_smi_info_union addr_info;
+
+	int (*io_setup)(struct si_sm_io *info);
+	void (*io_cleanup)(struct si_sm_io *info);
+	unsigned int io_size;
+
+	int irq;
+	int (*irq_setup)(struct si_sm_io *io);
+	void *irq_handler_data;
+	void (*irq_cleanup)(struct si_sm_io *io);
+
+	u8 slave_addr;
+	enum si_type si_type;
+	struct device *dev;
+};
 
 int ipmi_si_add_smi(struct si_sm_io *io);
 irqreturn_t ipmi_si_irq_handler(int irq, void *data);
@@ -50,3 +101,5 @@ static inline void ipmi_si_parisc_shutdown(void) { }
 
 int ipmi_si_port_setup(struct si_sm_io *io);
 int ipmi_si_mem_setup(struct si_sm_io *io);
+
+#endif /* __IPMI_SI_H__ */

drivers/char/ipmi/ipmi_si_intf.c

@@ -40,6 +40,7 @@
 #include <linux/ipmi.h>
 #include <linux/ipmi_smi.h>
 #include "ipmi_si.h"
+#include "ipmi_si_sm.h"
 #include <linux/string.h>
 #include <linux/ctype.h>
 
@@ -221,6 +222,9 @@ struct smi_info {
 	 */
 	bool irq_enable_broken;
 
+	/* Is the driver in maintenance mode? */
+	bool in_maintenance_mode;
+
 	/*
 	 * Did we get an attention that we did not handle?
 	 */
@@ -261,10 +265,10 @@ static void cleanup_ipmi_si(void);
 #ifdef DEBUG_TIMING
 void debug_timestamp(char *msg)
 {
-	struct timespec64 t;
+	struct timespec t;
 
-	ktime_get_ts64(&t);
-	pr_debug("**%s: %lld.%9.9ld\n", msg, (long long) t.tv_sec, t.tv_nsec);
+	ktime_get_ts(&t);
+	pr_debug("**%s: %ld.%9.9ld\n", msg, (long) t.tv_sec, t.tv_nsec);
 }
 #else
 #define debug_timestamp(x)
@@ -935,18 +939,18 @@ static void set_run_to_completion(void *send_info, bool i_run_to_completion)
  * we are spinning in kipmid looking for something and not delaying
  * between checks
  */
-static inline void ipmi_si_set_not_busy(struct timespec64 *ts)
+static inline void ipmi_si_set_not_busy(struct timespec *ts)
 {
 	ts->tv_nsec = -1;
 }
-static inline int ipmi_si_is_busy(struct timespec64 *ts)
+static inline int ipmi_si_is_busy(struct timespec *ts)
 {
 	return ts->tv_nsec != -1;
 }
 
-static inline int ipmi_thread_busy_wait(enum si_sm_result smi_result,
+static inline bool ipmi_thread_busy_wait(enum si_sm_result smi_result,
 					 const struct smi_info *smi_info,
-					struct timespec64 *busy_until)
+					 struct timespec *busy_until)
 {
 	unsigned int max_busy_us = 0;
 
@@ -955,18 +959,18 @@ static inline int ipmi_thread_busy_wait(enum si_sm_result smi_result,
 	if (max_busy_us == 0 || smi_result != SI_SM_CALL_WITH_DELAY)
 		ipmi_si_set_not_busy(busy_until);
 	else if (!ipmi_si_is_busy(busy_until)) {
-		ktime_get_ts64(busy_until);
-		timespec64_add_ns(busy_until, max_busy_us*NSEC_PER_USEC);
+		ktime_get_ts(busy_until);
+		timespec_add_ns(busy_until, max_busy_us * NSEC_PER_USEC);
 	} else {
-		struct timespec64 now;
+		struct timespec now;
 
-		ktime_get_ts64(&now);
-		if (unlikely(timespec64_compare(&now, busy_until) > 0)) {
+		ktime_get_ts(&now);
+		if (unlikely(timespec_compare(&now, busy_until) > 0)) {
 			ipmi_si_set_not_busy(busy_until);
-			return 0;
+			return false;
 		}
 	}
-	return 1;
+	return true;
 }
 
 
@@ -984,7 +988,7 @@ static int ipmi_thread(void *data)
 	struct smi_info *smi_info = data;
 	unsigned long flags;
 	enum si_sm_result smi_result;
-	struct timespec64 busy_until;
+	struct timespec busy_until = { 0, 0 };
 
 	ipmi_si_set_not_busy(&busy_until);
 	set_user_nice(current, MAX_NICE);
@@ -1007,11 +1011,20 @@ static int ipmi_thread(void *data)
 		spin_unlock_irqrestore(&(smi_info->si_lock), flags);
 		busy_wait = ipmi_thread_busy_wait(smi_result, smi_info,
 						  &busy_until);
-		if (smi_result == SI_SM_CALL_WITHOUT_DELAY)
+		if (smi_result == SI_SM_CALL_WITHOUT_DELAY) {
 			; /* do nothing */
-		else if (smi_result == SI_SM_CALL_WITH_DELAY && busy_wait)
+		} else if (smi_result == SI_SM_CALL_WITH_DELAY && busy_wait) {
+			/*
+			 * In maintenance mode we run as fast as
+			 * possible to allow firmware updates to
+			 * complete as fast as possible, but normally
+			 * don't bang on the scheduler.
+			 */
+			if (smi_info->in_maintenance_mode)
 				schedule();
-		else if (smi_result == SI_SM_IDLE) {
+			else
+				usleep_range(100, 200);
+		} else if (smi_result == SI_SM_IDLE) {
 			if (atomic_read(&smi_info->need_watch)) {
 				schedule_timeout_interruptible(100);
 			} else {
@@ -1019,9 +1032,10 @@ static int ipmi_thread(void *data)
 				__set_current_state(TASK_INTERRUPTIBLE);
 				schedule();
 			}
-		} else
+		} else {
 			schedule_timeout_interruptible(1);
 		}
+	}
 	return 0;
 }
 
@@ -1198,6 +1212,7 @@ static void set_maintenance_mode(void *send_info, bool enable)
 
 	if (!enable)
 		atomic_set(&smi_info->req_events, 0);
+	smi_info->in_maintenance_mode = enable;
 }
 
 static void shutdown_smi(void *send_info);
@@ -1266,12 +1281,12 @@ int ipmi_std_irq_setup(struct si_sm_io *io)
 	rv = request_irq(io->irq,
 			 ipmi_si_irq_handler,
 			 IRQF_SHARED,
-			 DEVICE_NAME,
+			 SI_DEVICE_NAME,
 			 io->irq_handler_data);
 	if (rv) {
 		dev_warn(io->dev, "%s unable to claim interrupt %d,"
 			 " running polled\n",
-			 DEVICE_NAME, io->irq);
+			 SI_DEVICE_NAME, io->irq);
 		io->irq = 0;
 	} else {
 		io->irq_cleanup = std_irq_cleanup;
@@ -1586,7 +1601,7 @@ static int try_enable_event_buffer(struct smi_info *smi_info)
 }
 
 #define IPMI_SI_ATTR(name) \
-static ssize_t ipmi_##name##_show(struct device *dev,			\
+static ssize_t name##_show(struct device *dev,			\
 			   struct device_attribute *attr,		\
 			   char *buf)					\
 {									\
@@ -1594,9 +1609,9 @@ static ssize_t ipmi_##name##_show(struct device *dev,			\
 									\
 	return snprintf(buf, 10, "%u\n", smi_get_stat(smi_info, name));	\
 }									\
-static DEVICE_ATTR(name, S_IRUGO, ipmi_##name##_show, NULL)
+static DEVICE_ATTR(name, 0444, name##_show, NULL)
 
-static ssize_t ipmi_type_show(struct device *dev,
+static ssize_t type_show(struct device *dev,
 			 struct device_attribute *attr,
 			 char *buf)
 {
@@ -1604,9 +1619,9 @@ static ssize_t ipmi_type_show(struct device *dev,
 
 	return snprintf(buf, 10, "%s\n", si_to_str[smi_info->io.si_type]);
 }
-static DEVICE_ATTR(type, S_IRUGO, ipmi_type_show, NULL);
+static DEVICE_ATTR(type, 0444, type_show, NULL);
 
-static ssize_t ipmi_interrupts_enabled_show(struct device *dev,
+static ssize_t interrupts_enabled_show(struct device *dev,
 				       struct device_attribute *attr,
 				       char *buf)
 {
@@ -1615,8 +1630,8 @@ static ssize_t ipmi_interrupts_enabled_show(struct device *dev,
 
 	return snprintf(buf, 10, "%d\n", enabled);
 }
-static DEVICE_ATTR(interrupts_enabled, S_IRUGO,
-		   ipmi_interrupts_enabled_show, NULL);
+static DEVICE_ATTR(interrupts_enabled, 0444,
+		   interrupts_enabled_show, NULL);
 
 IPMI_SI_ATTR(short_timeouts);
 IPMI_SI_ATTR(long_timeouts);
@@ -1630,7 +1645,7 @@ IPMI_SI_ATTR(events);
 IPMI_SI_ATTR(watchdog_pretimeouts);
 IPMI_SI_ATTR(incoming_messages);
 
-static ssize_t ipmi_params_show(struct device *dev,
+static ssize_t params_show(struct device *dev,
 			   struct device_attribute *attr,
 			   char *buf)
 {
@@ -1647,7 +1662,7 @@ static ssize_t ipmi_params_show(struct device *dev,
 			smi_info->io.irq,
 			smi_info->io.slave_addr);
 }
-static DEVICE_ATTR(params, S_IRUGO, ipmi_params_show, NULL);
+static DEVICE_ATTR(params, 0444, params_show, NULL);
 
 static struct attribute *ipmi_si_dev_attrs[] = {
 	&dev_attr_type.attr,
@@ -1828,7 +1843,6 @@ static inline void stop_timer_and_thread(struct smi_info *smi_info)
 	}
 
 	smi_info->timer_can_start = false;
-	if (smi_info->timer_running)
 	del_timer_sync(&smi_info->si_timer);
 }
 

drivers/char/ipmi/ipmi_si_mem_io.c

@@ -118,7 +118,7 @@ int ipmi_si_mem_setup(struct si_sm_io *io)
 	 */
 	for (idx = 0; idx < io->io_size; idx++) {
 		if (request_mem_region(addr + idx * io->regspacing,
-				       io->regsize, DEVICE_NAME) == NULL) {
+				       io->regsize, SI_DEVICE_NAME) == NULL) {
 			/* Undo allocations */
 			mem_region_cleanup(io, idx);
 			return -EIO;

drivers/char/ipmi/ipmi_si_pci.c

@@ -150,7 +150,7 @@ static const struct pci_device_id ipmi_pci_devices[] = {
 MODULE_DEVICE_TABLE(pci, ipmi_pci_devices);
 
 static struct pci_driver ipmi_pci_driver = {
-	.name =         DEVICE_NAME,
+	.name =         SI_DEVICE_NAME,
 	.id_table =     ipmi_pci_devices,
 	.probe =        ipmi_pci_probe,
 	.remove =       ipmi_pci_remove,

drivers/char/ipmi/ipmi_si_platform.c

@@ -457,7 +457,7 @@ static const struct platform_device_id si_plat_ids[] = {
 
 struct platform_driver ipmi_platform_driver = {
 	.driver = {
-		.name = DEVICE_NAME,
+		.name = SI_DEVICE_NAME,
 		.of_match_table = of_ipmi_match,
 		.acpi_match_table = ACPI_PTR(acpi_ipmi_match),
 	},

drivers/char/ipmi/ipmi_si_port_io.c

@@ -99,7 +99,7 @@ int ipmi_si_port_setup(struct si_sm_io *io)
 	 */
 	for (idx = 0; idx < io->io_size; idx++) {
 		if (request_region(addr + idx * io->regspacing,
-				   io->regsize, DEVICE_NAME) == NULL) {
+				   io->regsize, SI_DEVICE_NAME) == NULL) {
 			/* Undo allocations */
 			while (idx--)
 				release_region(addr + idx * io->regspacing,

drivers/char/ipmi/ipmi_si_sm.h

@@ -14,7 +14,10 @@
  * Copyright 2002 MontaVista Software Inc.
  */
 
-#include <linux/ipmi.h>
+#ifndef __IPMI_SI_SM_H__
+#define __IPMI_SI_SM_H__
+
+#include "ipmi_si.h"
 
 /*
  * This is defined by the state machines themselves, it is an opaque
@@ -22,54 +25,6 @@
  */
 struct si_sm_data;
 
-enum si_type {
-	SI_TYPE_INVALID, SI_KCS, SI_SMIC, SI_BT
-};
-
-enum ipmi_addr_space {
-	IPMI_IO_ADDR_SPACE, IPMI_MEM_ADDR_SPACE
-};
-
-/*
- * The structure for doing I/O in the state machine.  The state
- * machine doesn't have the actual I/O routines, they are done through
- * this interface.
- */
-struct si_sm_io {
-	unsigned char (*inputb)(const struct si_sm_io *io, unsigned int offset);
-	void (*outputb)(const struct si_sm_io *io,
-			unsigned int  offset,
-			unsigned char b);
-
-	/*
-	 * Generic info used by the actual handling routines, the
-	 * state machine shouldn't touch these.
-	 */
-	void __iomem *addr;
-	unsigned int regspacing;
-	unsigned int regsize;
-	unsigned int regshift;
-	enum ipmi_addr_space addr_space;
-	unsigned long addr_data;
-	enum ipmi_addr_src addr_source; /* ACPI, PCI, SMBIOS, hardcode, etc. */
-	void (*addr_source_cleanup)(struct si_sm_io *io);
-	void *addr_source_data;
-	union ipmi_smi_info_union addr_info;
-
-	int (*io_setup)(struct si_sm_io *info);
-	void (*io_cleanup)(struct si_sm_io *info);
-	unsigned int io_size;
-
-	int irq;
-	int (*irq_setup)(struct si_sm_io *io);
-	void *irq_handler_data;
-	void (*irq_cleanup)(struct si_sm_io *io);
-
-	u8 slave_addr;
-	enum si_type si_type;
-	struct device *dev;
-};
-
 /* Results of SMI events. */
 enum si_sm_result {
 	SI_SM_CALL_WITHOUT_DELAY, /* Call the driver again immediately */
@@ -146,3 +101,4 @@ extern const struct si_sm_handlers kcs_smi_handlers;
 extern const struct si_sm_handlers smic_smi_handlers;
 extern const struct si_sm_handlers bt_smi_handlers;
 
+#endif /* __IPMI_SI_SM_H__ */

drivers/char/ipmi/ipmi_ssif.c

@@ -52,7 +52,6 @@
 #include <linux/acpi.h>
 #include <linux/ctype.h>
 #include <linux/time64.h>
-#include "ipmi_si_sm.h"
 #include "ipmi_dmi.h"
 
 #define DEVICE_NAME "ipmi_ssif"
@@ -1428,6 +1427,10 @@ static struct ssif_addr_info *ssif_info_find(unsigned short addr,
 restart:
 	list_for_each_entry(info, &ssif_infos, link) {
 		if (info->binfo.addr == addr) {
+			if (info->addr_src == SI_SMBIOS)
+				info->adapter_name = kstrdup(adapter_name,
+							     GFP_KERNEL);
+
 			if (info->adapter_name || adapter_name) {
 				if (!info->adapter_name != !adapter_name) {
 					/* One is NULL and one is not */
@@ -1603,6 +1606,60 @@ static void test_multipart_messages(struct i2c_client *client,
 #define GLOBAL_ENABLES_MASK (IPMI_BMC_EVT_MSG_BUFF | IPMI_BMC_RCV_MSG_INTR | \
 			     IPMI_BMC_EVT_MSG_INTR)
 
+static void ssif_remove_dup(struct i2c_client *client)
+{
+	struct ssif_info *ssif_info = i2c_get_clientdata(client);
+
+	ipmi_unregister_smi(ssif_info->intf);
+	kfree(ssif_info);
+}
+
+static int ssif_add_infos(struct i2c_client *client)
+{
+	struct ssif_addr_info *info;
+
+	info = kzalloc(sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+	info->addr_src = SI_ACPI;
+	info->client = client;
+	info->adapter_name = kstrdup(client->adapter->name, GFP_KERNEL);
+	info->binfo.addr = client->addr;
+	list_add_tail(&info->link, &ssif_infos);
+	return 0;
+}
+
+/*
+ * Prefer ACPI over SMBIOS, if both are available.
+ * So if we get an ACPI interface and have already registered a SMBIOS
+ * interface at the same address, remove the SMBIOS and add the ACPI one.
+ */
+static int ssif_check_and_remove(struct i2c_client *client,
+			      struct ssif_info *ssif_info)
+{
+	struct ssif_addr_info *info;
+
+	list_for_each_entry(info, &ssif_infos, link) {
+		if (!info->client)
+			return 0;
+		if (!strcmp(info->adapter_name, client->adapter->name) &&
+		    info->binfo.addr == client->addr) {
+			if (info->addr_src == SI_ACPI)
+				return -EEXIST;
+
+			if (ssif_info->addr_source == SI_ACPI &&
+			    info->addr_src == SI_SMBIOS) {
+				dev_info(&client->dev,
+					 "Removing %s-specified SSIF interface in favor of ACPI\n",
+					 ipmi_addr_src_to_str(info->addr_src));
+				ssif_remove_dup(info->client);
+				return 0;
+			}
+		}
+	}
+	return 0;
+}
+
 static int ssif_probe(struct i2c_client *client, const struct i2c_device_id *id)
 {
 	unsigned char     msg[3];
@@ -1614,13 +1671,17 @@ static int ssif_probe(struct i2c_client *client, const struct i2c_device_id *id)
 	u8		  slave_addr = 0;
 	struct ssif_addr_info *addr_info = NULL;
 
+	mutex_lock(&ssif_infos_mutex);
 	resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
-	if (!resp)
+	if (!resp) {
+		mutex_unlock(&ssif_infos_mutex);
 		return -ENOMEM;
+	}
 
 	ssif_info = kzalloc(sizeof(*ssif_info), GFP_KERNEL);
 	if (!ssif_info) {
 		kfree(resp);
+		mutex_unlock(&ssif_infos_mutex);
 		return -ENOMEM;
 	}
 
@@ -1639,6 +1700,19 @@ static int ssif_probe(struct i2c_client *client, const struct i2c_device_id *id)
 		}
 	}
 
+	rv = ssif_check_and_remove(client, ssif_info);
+	/* If rv is 0 and addr source is not SI_ACPI, continue probing */
+	if (!rv && ssif_info->addr_source == SI_ACPI) {
+		rv = ssif_add_infos(client);
+		if (rv) {
+			dev_err(&client->dev, "Out of memory!, exiting ..\n");
+			goto out;
+		}
+	} else if (rv) {
+		dev_err(&client->dev, "Not probing, Interface already present\n");
+		goto out;
+	}
+
 	slave_addr = find_slave_address(client, slave_addr);
 
 	dev_info(&client->dev,
@@ -1851,6 +1925,7 @@ static int ssif_probe(struct i2c_client *client, const struct i2c_device_id *id)
 		kfree(ssif_info);
 	}
 	kfree(resp);
+	mutex_unlock(&ssif_infos_mutex);
 	return rv;
 
 out_remove_attr: