Merge branch 'ipmi' (emailed ipmi fixes)

Merge ipmi fixes from Corey Minyard:
 "Things collected since last kernel release.

  Some of these are pretty important.  The first three are bug fixes.
  The next two are to hopefully make everyone happy about allowing
  ACPI to be on all the time and not have IPMI have an effect on the
  system when not in use.  The last is a little cleanup"

* emailed patches from Corey Minyard <cminyard@mvista.com>:
  ipmi: boolify some things
  ipmi: Turn off all activity on an idle ipmi interface
  ipmi: Turn off default probing of interfaces
  ipmi: Reset the KCS timeout when starting error recovery
  ipmi: Fix a race restarting the timer
  Char: ipmi_bt_sm, fix infinite loop

1 files changed, 144 insertions, 95 deletions

diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
index ec4e10fcf1a5..e6db9381b2c7 100644
--- a/drivers/char/ipmi/ipmi_msghandler.c
+++ b/drivers/char/ipmi/ipmi_msghandler.c
@@ -55,6 +55,7 @@ static struct ipmi_recv_msg *ipmi_alloc_recv_msg(void);
 static int ipmi_init_msghandler(void);
 static void smi_recv_tasklet(unsigned long);
 static void handle_new_recv_msgs(ipmi_smi_t intf);
+static void need_waiter(ipmi_smi_t intf);
 
 static int initialized;
 
@@ -73,14 +74,28 @@ static struct proc_dir_entry *proc_ipmi_root;
  */
 #define MAX_MSG_TIMEOUT		60000
 
+/* Call every ~1000 ms. */
+#define IPMI_TIMEOUT_TIME	1000
+
+/* How many jiffies does it take to get to the timeout time. */
+#define IPMI_TIMEOUT_JIFFIES	((IPMI_TIMEOUT_TIME * HZ) / 1000)
+
+/*
+ * Request events from the queue every second (this is the number of
+ * IPMI_TIMEOUT_TIMES between event requests).  Hopefully, in the
+ * future, IPMI will add a way to know immediately if an event is in
+ * the queue and this silliness can go away.
+ */
+#define IPMI_REQUEST_EV_TIME	(1000 / (IPMI_TIMEOUT_TIME))
+
 /*
  * The main "user" data structure.
  */
 struct ipmi_user {
 	struct list_head link;
 
-	/* Set to "0" when the user is destroyed. */
-	int valid;
+	/* Set to false when the user is destroyed. */
+	bool valid;
 
 	struct kref refcount;
 
@@ -92,7 +107,7 @@ struct ipmi_user {
 	ipmi_smi_t intf;
 
 	/* Does this interface receive IPMI events? */
-	int gets_events;
+	bool gets_events;
 };
 
 struct cmd_rcvr {
@@ -383,6 +398,9 @@ struct ipmi_smi {
 	unsigned int     waiting_events_count; /* How many events in queue? */
 	char             delivering_events;
 	char             event_msg_printed;
+	atomic_t         event_waiters;
+	unsigned int     ticks_to_req_ev;
+	int              last_needs_timer;
 
 	/*
 	 * The event receiver for my BMC, only really used at panic
@@ -395,7 +413,7 @@ struct ipmi_smi {
 
 	/* For handling of maintenance mode. */
 	int maintenance_mode;
-	int maintenance_mode_enable;
+	bool maintenance_mode_enable;
 	int auto_maintenance_timeout;
 	spinlock_t maintenance_mode_lock; /* Used in a timer... */
 
@@ -451,7 +469,6 @@ static DEFINE_MUTEX(ipmi_interfaces_mutex);
 static LIST_HEAD(smi_watchers);
 static DEFINE_MUTEX(smi_watchers_mutex);
 
-
 #define ipmi_inc_stat(intf, stat) \
 	atomic_inc(&(intf)->stats[IPMI_STAT_ ## stat])
 #define ipmi_get_stat(intf, stat) \
@@ -772,6 +789,7 @@ static int intf_next_seq(ipmi_smi_t           intf,
 		*seq = i;
 		*seqid = intf->seq_table[i].seqid;
 		intf->curr_seq = (i+1)%IPMI_IPMB_NUM_SEQ;
+		need_waiter(intf);
 	} else {
 		rv = -EAGAIN;
 	}
@@ -941,7 +959,7 @@ int ipmi_create_user(unsigned int          if_num,
 	new_user->handler = handler;
 	new_user->handler_data = handler_data;
 	new_user->intf = intf;
-	new_user->gets_events = 0;
+	new_user->gets_events = false;
 
 	if (!try_module_get(intf->handlers->owner)) {
 		rv = -ENODEV;
@@ -962,10 +980,15 @@ int ipmi_create_user(unsigned int          if_num,
 	 */
 	mutex_unlock(&ipmi_interfaces_mutex);
 
-	new_user->valid = 1;
+	new_user->valid = true;
 	spin_lock_irqsave(&intf->seq_lock, flags);
 	list_add_rcu(&new_user->link, &intf->users);
 	spin_unlock_irqrestore(&intf->seq_lock, flags);
+	if (handler->ipmi_watchdog_pretimeout) {
+		/* User wants pretimeouts, so make sure to watch for them. */
+		if (atomic_inc_return(&intf->event_waiters) == 1)
+			need_waiter(intf);
+	}
 	*user = new_user;
 	return 0;
 
@@ -1019,7 +1042,13 @@ int ipmi_destroy_user(ipmi_user_t user)
 	struct cmd_rcvr  *rcvr;
 	struct cmd_rcvr  *rcvrs = NULL;
 
-	user->valid = 0;
+	user->valid = false;
+
+	if (user->handler->ipmi_watchdog_pretimeout)
+		atomic_dec(&intf->event_waiters);
+
+	if (user->gets_events)
+		atomic_dec(&intf->event_waiters);
 
 	/* Remove the user from the interface's sequence table. */
 	spin_lock_irqsave(&intf->seq_lock, flags);
@@ -1155,25 +1184,23 @@ int ipmi_set_maintenance_mode(ipmi_user_t user, int mode)
 	if (intf->maintenance_mode != mode) {
 		switch (mode) {
 		case IPMI_MAINTENANCE_MODE_AUTO:
-			intf->maintenance_mode = mode;
 			intf->maintenance_mode_enable
 				= (intf->auto_maintenance_timeout > 0);
 			break;
 
 		case IPMI_MAINTENANCE_MODE_OFF:
-			intf->maintenance_mode = mode;
-			intf->maintenance_mode_enable = 0;
+			intf->maintenance_mode_enable = false;
 			break;
 
 		case IPMI_MAINTENANCE_MODE_ON:
-			intf->maintenance_mode = mode;
-			intf->maintenance_mode_enable = 1;
+			intf->maintenance_mode_enable = true;
 			break;
 
 		default:
 			rv = -EINVAL;
 			goto out_unlock;
 		}
+		intf->maintenance_mode = mode;
 
 		maintenance_mode_update(intf);
 	}
@@ -1184,7 +1211,7 @@ int ipmi_set_maintenance_mode(ipmi_user_t user, int mode)
 }
 EXPORT_SYMBOL(ipmi_set_maintenance_mode);
 
-int ipmi_set_gets_events(ipmi_user_t user, int val)
+int ipmi_set_gets_events(ipmi_user_t user, bool val)
 {
 	unsigned long        flags;
 	ipmi_smi_t           intf = user->intf;
@@ -1194,8 +1221,18 @@ int ipmi_set_gets_events(ipmi_user_t user, int val)
 	INIT_LIST_HEAD(&msgs);
 
 	spin_lock_irqsave(&intf->events_lock, flags);
+	if (user->gets_events == val)
+		goto out;
+
 	user->gets_events = val;
 
+	if (val) {
+		if (atomic_inc_return(&intf->event_waiters) == 1)
+			need_waiter(intf);
+	} else {
+		atomic_dec(&intf->event_waiters);
+	}
+
 	if (intf->delivering_events)
 		/*
 		 * Another thread is delivering events for this, so
@@ -1289,6 +1326,9 @@ int ipmi_register_for_cmd(ipmi_user_t   user,
 		goto out_unlock;
 	}
 
+	if (atomic_inc_return(&intf->event_waiters) == 1)
+		need_waiter(intf);
+
 	list_add_rcu(&rcvr->link, &intf->cmd_rcvrs);
 
  out_unlock:
@@ -1330,6 +1370,7 @@ int ipmi_unregister_for_cmd(ipmi_user_t   user,
 	mutex_unlock(&intf->cmd_rcvrs_mutex);
 	synchronize_rcu();
 	while (rcvrs) {
+		atomic_dec(&intf->event_waiters);
 		rcvr = rcvrs;
 		rcvrs = rcvr->next;
 		kfree(rcvr);
@@ -1535,7 +1576,7 @@ static int i_ipmi_request(ipmi_user_t          user,
 				= IPMI_MAINTENANCE_MODE_TIMEOUT;
 			if (!intf->maintenance_mode
 			    && !intf->maintenance_mode_enable) {
-				intf->maintenance_mode_enable = 1;
+				intf->maintenance_mode_enable = true;
 				maintenance_mode_update(intf);
 			}
 			spin_unlock_irqrestore(&intf->maintenance_mode_lock,
@@ -2876,6 +2917,8 @@ int ipmi_register_smi(struct ipmi_smi_handlers *handlers,
 		     (unsigned long) intf);
 	atomic_set(&intf->watchdog_pretimeouts_to_deliver, 0);
 	spin_lock_init(&intf->events_lock);
+	atomic_set(&intf->event_waiters, 0);
+	intf->ticks_to_req_ev = IPMI_REQUEST_EV_TIME;
 	INIT_LIST_HEAD(&intf->waiting_events);
 	intf->waiting_events_count = 0;
 	mutex_init(&intf->cmd_rcvrs_mutex);
@@ -3965,7 +4008,8 @@ smi_from_recv_msg(ipmi_smi_t intf, struct ipmi_recv_msg *recv_msg,
 
 static void check_msg_timeout(ipmi_smi_t intf, struct seq_table *ent,
 			      struct list_head *timeouts, long timeout_period,
-			      int slot, unsigned long *flags)
+			      int slot, unsigned long *flags,
+			      unsigned int *waiting_msgs)
 {
 	struct ipmi_recv_msg     *msg;
 	struct ipmi_smi_handlers *handlers;
@@ -3977,8 +4021,10 @@ static void check_msg_timeout(ipmi_smi_t intf, struct seq_table *ent,
 		return;
 
 	ent->timeout -= timeout_period;
-	if (ent->timeout > 0)
+	if (ent->timeout > 0) {
+		(*waiting_msgs)++;
 		return;
+	}
 
 	if (ent->retries_left == 0) {
 		/* The message has used all its retries. */
@@ -3995,6 +4041,8 @@ static void check_msg_timeout(ipmi_smi_t intf, struct seq_table *ent,
 		struct ipmi_smi_msg *smi_msg;
 		/* More retries, send again. */
 
+		(*waiting_msgs)++;
+
 		/*
 		 * Start with the max timer, set to normal timer after
 		 * the message is sent.
@@ -4040,117 +4088,118 @@ static void check_msg_timeout(ipmi_smi_t intf, struct seq_table *ent,
 	}
 }
 
-static void ipmi_timeout_handler(long timeout_period)
+static unsigned int ipmi_timeout_handler(ipmi_smi_t intf, long timeout_period)
 {
-	ipmi_smi_t           intf;
 	struct list_head     timeouts;
 	struct ipmi_recv_msg *msg, *msg2;
 	unsigned long        flags;
 	int                  i;
+	unsigned int         waiting_msgs = 0;
 
-	rcu_read_lock();
-	list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
-		tasklet_schedule(&intf->recv_tasklet);
-
-		/*
-		 * Go through the seq table and find any messages that
-		 * have timed out, putting them in the timeouts
-		 * list.
-		 */
-		INIT_LIST_HEAD(&timeouts);
-		spin_lock_irqsave(&intf->seq_lock, flags);
-		for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++)
-			check_msg_timeout(intf, &(intf->seq_table[i]),
-					  &timeouts, timeout_period, i,
-					  &flags);
-		spin_unlock_irqrestore(&intf->seq_lock, flags);
+	/*
+	 * Go through the seq table and find any messages that
+	 * have timed out, putting them in the timeouts
+	 * list.
+	 */
+	INIT_LIST_HEAD(&timeouts);
+	spin_lock_irqsave(&intf->seq_lock, flags);
+	for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++)
+		check_msg_timeout(intf, &(intf->seq_table[i]),
+				  &timeouts, timeout_period, i,
+				  &flags, &waiting_msgs);
+	spin_unlock_irqrestore(&intf->seq_lock, flags);
 
-		list_for_each_entry_safe(msg, msg2, &timeouts, link)
-			deliver_err_response(msg, IPMI_TIMEOUT_COMPLETION_CODE);
+	list_for_each_entry_safe(msg, msg2, &timeouts, link)
+		deliver_err_response(msg, IPMI_TIMEOUT_COMPLETION_CODE);
 
-		/*
-		 * Maintenance mode handling.  Check the timeout
-		 * optimistically before we claim the lock.  It may
-		 * mean a timeout gets missed occasionally, but that
-		 * only means the timeout gets extended by one period
-		 * in that case.  No big deal, and it avoids the lock
-		 * most of the time.
-		 */
+	/*
+	 * Maintenance mode handling.  Check the timeout
+	 * optimistically before we claim the lock.  It may
+	 * mean a timeout gets missed occasionally, but that
+	 * only means the timeout gets extended by one period
+	 * in that case.  No big deal, and it avoids the lock
+	 * most of the time.
+	 */
+	if (intf->auto_maintenance_timeout > 0) {
+		spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
 		if (intf->auto_maintenance_timeout > 0) {
-			spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
-			if (intf->auto_maintenance_timeout > 0) {
-				intf->auto_maintenance_timeout
-					-= timeout_period;
-				if (!intf->maintenance_mode
-				    && (intf->auto_maintenance_timeout <= 0)) {
-					intf->maintenance_mode_enable = 0;
-					maintenance_mode_update(intf);
-				}
+			intf->auto_maintenance_timeout
+				-= timeout_period;
+			if (!intf->maintenance_mode
+			    && (intf->auto_maintenance_timeout <= 0)) {
+				intf->maintenance_mode_enable = false;
+				maintenance_mode_update(intf);
 			}
-			spin_unlock_irqrestore(&intf->maintenance_mode_lock,
-					       flags);
 		}
+		spin_unlock_irqrestore(&intf->maintenance_mode_lock,
+				       flags);
 	}
-	rcu_read_unlock();
+
+	tasklet_schedule(&intf->recv_tasklet);
+
+	return waiting_msgs;
 }
 
-static void ipmi_request_event(void)
+static void ipmi_request_event(ipmi_smi_t intf)
 {
-	ipmi_smi_t               intf;
 	struct ipmi_smi_handlers *handlers;
 
-	rcu_read_lock();
-	/*
-	 * Called from the timer, no need to check if handlers is
-	 * valid.
-	 */
-	list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
-		/* No event requests when in maintenance mode. */
-		if (intf->maintenance_mode_enable)
-			continue;
+	/* No event requests when in maintenance mode. */
+	if (intf->maintenance_mode_enable)
+		return;
 
-		handlers = intf->handlers;
-		if (handlers)
-			handlers->request_events(intf->send_info);
-	}
-	rcu_read_unlock();
+	handlers = intf->handlers;
+	if (handlers)
+		handlers->request_events(intf->send_info);
 }
 
 static struct timer_list ipmi_timer;
 
-/* Call every ~1000 ms. */
-#define IPMI_TIMEOUT_TIME	1000
-
-/* How many jiffies does it take to get to the timeout time. */
-#define IPMI_TIMEOUT_JIFFIES	((IPMI_TIMEOUT_TIME * HZ) / 1000)
-
-/*
- * Request events from the queue every second (this is the number of
- * IPMI_TIMEOUT_TIMES between event requests).  Hopefully, in the
- * future, IPMI will add a way to know immediately if an event is in
- * the queue and this silliness can go away.
- */
-#define IPMI_REQUEST_EV_TIME	(1000 / (IPMI_TIMEOUT_TIME))
-
 static atomic_t stop_operation;
-static unsigned int ticks_to_req_ev = IPMI_REQUEST_EV_TIME;
 
 static void ipmi_timeout(unsigned long data)
 {
+	ipmi_smi_t intf;
+	int nt = 0;
+
 	if (atomic_read(&stop_operation))
 		return;
 
-	ticks_to_req_ev--;
-	if (ticks_to_req_ev == 0) {
-		ipmi_request_event();
-		ticks_to_req_ev = IPMI_REQUEST_EV_TIME;
-	}
+	rcu_read_lock();
+	list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
+		int lnt = 0;
+
+		if (atomic_read(&intf->event_waiters)) {
+			intf->ticks_to_req_ev--;
+			if (intf->ticks_to_req_ev == 0) {
+				ipmi_request_event(intf);
+				intf->ticks_to_req_ev = IPMI_REQUEST_EV_TIME;
+			}
+			lnt++;
+		}
 
-	ipmi_timeout_handler(IPMI_TIMEOUT_TIME);
+		lnt += ipmi_timeout_handler(intf, IPMI_TIMEOUT_TIME);
 
-	mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
+		lnt = !!lnt;
+		if (lnt != intf->last_needs_timer &&
+					intf->handlers->set_need_watch)
+			intf->handlers->set_need_watch(intf->send_info, lnt);
+		intf->last_needs_timer = lnt;
+
+		nt += lnt;
+	}
+	rcu_read_unlock();
+
+	if (nt)
+		mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
 }
 
+static void need_waiter(ipmi_smi_t intf)
+{
+	/* Racy, but worst case we start the timer twice. */
+	if (!timer_pending(&ipmi_timer))
+		mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
+}
 
 static atomic_t smi_msg_inuse_count = ATOMIC_INIT(0);
 static atomic_t recv_msg_inuse_count = ATOMIC_INIT(0);