Commit c65ea996 authored by Corey Minyard's avatar Corey Minyard
Browse files

ipmi: Fix how the lower layers are told to watch for messages 



The IPMI driver has a mechanism to tell the lower layers it needs
to watch for messages, commands, and watchdogs (so it doesn't
needlessly poll).  However, it needed some extensions, it needed
a way to tell what is being waited for so it could set the timeout
appropriately.

The update to the lower layer was also being done once a second
at best because it was done in the main timeout handler.  However,
if a command is sent and a response message is coming back,
it needed to be started immediately.  So modify the code to
update immediately if it needs to be enabled.  Disable is still
lazy.

Signed-off-by: default avatarCorey Minyard <cminyard@mvista.com>
Tested-by: default avatarKamlakant Patel <kamlakant.patel@cavium.com>
parent a1466ec5

drivers/char/ipmi/ipmi_msghandler.c

+85 −34
Original line number Diff line number Diff line
@@ -529,9 +529,22 @@ struct ipmi_smi { 
	unsigned int     waiting_events_count; /* How many events in queue? */

	char             delivering_events;

	char             event_msg_printed;



	/* How many users are waiting for events? */

	atomic_t         event_waiters;

	unsigned int     ticks_to_req_ev;

	int              last_needs_timer;



	/* How many users are waiting for commands? */

	atomic_t         command_waiters;



	/* How many users are waiting for watchdogs? */

	atomic_t         watchdog_waiters;



	/*

	 * Tells what the lower layer has last been asked to watch for,

	 * messages and/or watchdogs.  Protected by xmit_msgs_lock.

	 */

	unsigned int     last_watch_mask;



	/*

	 * The event receiver for my BMC, only really used at panic
@@ -1078,6 +1091,29 @@ static int intf_err_seq(struct ipmi_smi *intf, 
	return rv;

}



/* Must be called with xmit_msgs_lock held. */

static void smi_tell_to_watch(struct ipmi_smi *intf,

			      unsigned int flags,

			      struct ipmi_smi_msg *smi_msg)

{

	if (flags & IPMI_WATCH_MASK_CHECK_MESSAGES) {

		if (!smi_msg)

			return;



		if (!smi_msg->needs_response)

			return;

	}



	if (!intf->handlers->set_need_watch)

		return;



	if ((intf->last_watch_mask & flags) == flags)

		return;



	intf->last_watch_mask |= flags;

	intf->handlers->set_need_watch(intf->send_info,

				       intf->last_watch_mask);

}



int ipmi_create_user(unsigned int          if_num,

		     const struct ipmi_user_hndl *handler,
@@ -1141,8 +1177,9 @@ int ipmi_create_user(unsigned int if_num, 
	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);

		if (atomic_inc_return(&intf->watchdog_waiters) == 1)

			smi_tell_to_watch(intf, IPMI_WATCH_MASK_CHECK_WATCHDOG,

					  NULL);

	}

	srcu_read_unlock(&ipmi_interfaces_srcu, index);

	*user = new_user;
@@ -1214,7 +1251,7 @@ static void _ipmi_destroy_user(struct ipmi_user *user) 
		user->handler->shutdown(user->handler_data);



	if (user->handler->ipmi_watchdog_pretimeout)

		atomic_dec(&intf->event_waiters);

		atomic_dec(&intf->watchdog_waiters);



	if (user->gets_events)

		atomic_dec(&intf->event_waiters);
@@ -1569,8 +1606,8 @@ int ipmi_register_for_cmd(struct ipmi_user *user, 
		goto out_unlock;

	}



	if (atomic_inc_return(&intf->event_waiters) == 1)

		need_waiter(intf);

	if (atomic_inc_return(&intf->command_waiters) == 1)

		smi_tell_to_watch(intf, IPMI_WATCH_MASK_CHECK_COMMANDS, NULL);



	list_add_rcu(&rcvr->link, &intf->cmd_rcvrs);
@@ -1620,7 +1657,7 @@ int ipmi_unregister_for_cmd(struct ipmi_user *user, 
	synchronize_rcu();

	release_ipmi_user(user, index);

	while (rcvrs) {

		atomic_dec(&intf->event_waiters);

		atomic_dec(&intf->command_waiters);

		rcvr = rcvrs;

		rcvrs = rcvr->next;

		kfree(rcvr);
@@ -1737,22 +1774,21 @@ static struct ipmi_smi_msg *smi_add_send_msg(struct ipmi_smi *intf, 
	return smi_msg;

}





static void smi_send(struct ipmi_smi *intf,

		     const struct ipmi_smi_handlers *handlers,

		     struct ipmi_smi_msg *smi_msg, int priority)

{

	int run_to_completion = intf->run_to_completion;

	unsigned long flags = 0;



	if (run_to_completion) {

		smi_msg = smi_add_send_msg(intf, smi_msg, priority);

	} else {

		unsigned long flags;



	if (!run_to_completion)

		spin_lock_irqsave(&intf->xmit_msgs_lock, flags);

	smi_msg = smi_add_send_msg(intf, smi_msg, priority);



	smi_tell_to_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES, smi_msg);



	if (!run_to_completion)

		spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags);

	}



	if (smi_msg)

		handlers->sender(intf->send_info, smi_msg);
@@ -1950,6 +1986,9 @@ static int i_ipmi_req_ipmb(struct ipmi_smi *intf, 
				ipmb_seq, broadcast,

				source_address, source_lun);



		/* We will be getting a response in the BMC message queue. */

		smi_msg->needs_response = true;



		/*

		 * Copy the message into the recv message data, so we

		 * can retransmit it later if necessary.
@@ -2137,6 +2176,7 @@ static int i_ipmi_request(struct ipmi_user *user, 
			goto out;

		}

	}

	smi_msg->needs_response = false;



	rcu_read_lock();

	if (intf->in_shutdown) {
@@ -3351,6 +3391,8 @@ int ipmi_register_smi(const struct ipmi_smi_handlers *handlers, 
	INIT_LIST_HEAD(&intf->hp_xmit_msgs);

	spin_lock_init(&intf->events_lock);

	atomic_set(&intf->event_waiters, 0);

	atomic_set(&intf->watchdog_waiters, 0);

	atomic_set(&intf->command_waiters, 0);

	intf->ticks_to_req_ev = IPMI_REQUEST_EV_TIME;

	INIT_LIST_HEAD(&intf->waiting_events);

	intf->waiting_events_count = 0;
@@ -4365,6 +4407,9 @@ static void smi_recv_tasklet(unsigned long val) 
			intf->curr_msg = newmsg;

		}

	}



	smi_tell_to_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES, newmsg);



	if (!run_to_completion)

		spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags);

	if (newmsg)
@@ -4492,7 +4537,7 @@ static void check_msg_timeout(struct ipmi_smi *intf, struct seq_table *ent, 
			      struct list_head *timeouts,

			      unsigned long timeout_period,

			      int slot, unsigned long *flags,

			      unsigned int *waiting_msgs)

			      unsigned int *watch_mask)

{

	struct ipmi_recv_msg *msg;
@@ -4504,7 +4549,7 @@ static void check_msg_timeout(struct ipmi_smi *intf, struct seq_table *ent, 


	if (timeout_period < ent->timeout) {

		ent->timeout -= timeout_period;

		(*waiting_msgs)++;

		*watch_mask |= IPMI_WATCH_MASK_CHECK_MESSAGES;

		return;

	}
@@ -4523,7 +4568,7 @@ static void check_msg_timeout(struct ipmi_smi *intf, struct seq_table *ent, 
		struct ipmi_smi_msg *smi_msg;

		/* More retries, send again. */



		(*waiting_msgs)++;

		*watch_mask |= IPMI_WATCH_MASK_CHECK_MESSAGES;



		/*

		 * Start with the max timer, set to normal timer after
@@ -4575,13 +4620,13 @@ static unsigned int ipmi_timeout_handler(struct ipmi_smi *intf, 
	struct ipmi_recv_msg *msg, *msg2;

	unsigned long        flags;

	int                  i;

	unsigned int         waiting_msgs = 0;

	unsigned int         watch_mask = 0;



	if (!intf->bmc_registered) {

		kref_get(&intf->refcount);

		if (!schedule_work(&intf->bmc_reg_work)) {

			kref_put(&intf->refcount, intf_free);

			waiting_msgs++;

			watch_mask |= IPMI_WATCH_MASK_INTERNAL;

		}

	}
@@ -4601,7 +4646,7 @@ static unsigned int ipmi_timeout_handler(struct ipmi_smi *intf, 
	for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++)

		check_msg_timeout(intf, &intf->seq_table[i],

				  &timeouts, timeout_period, i,

				  &flags, &waiting_msgs);

				  &flags, &watch_mask);

	spin_unlock_irqrestore(&intf->seq_lock, flags);



	list_for_each_entry_safe(msg, msg2, &timeouts, link)
@@ -4632,7 +4677,7 @@ static unsigned int ipmi_timeout_handler(struct ipmi_smi *intf, 


	tasklet_schedule(&intf->recv_tasklet);



	return waiting_msgs;

	return watch_mask;

}



static void ipmi_request_event(struct ipmi_smi *intf)
@@ -4652,37 +4697,43 @@ static atomic_t stop_operation; 
static void ipmi_timeout(struct timer_list *unused)

{

	struct ipmi_smi *intf;

	int nt = 0, index;

	unsigned int watch_mask = 0;

	int index;

	unsigned long flags;



	if (atomic_read(&stop_operation))

		return;



	index = srcu_read_lock(&ipmi_interfaces_srcu);

	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++;

			watch_mask |= IPMI_WATCH_MASK_INTERNAL;

		}



		lnt += ipmi_timeout_handler(intf, IPMI_TIMEOUT_TIME);

		if (atomic_read(&intf->watchdog_waiters))

			watch_mask |= IPMI_WATCH_MASK_CHECK_WATCHDOG;



		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;

		if (atomic_read(&intf->command_waiters))

			watch_mask |= IPMI_WATCH_MASK_CHECK_COMMANDS;



		watch_mask |= ipmi_timeout_handler(intf, IPMI_TIMEOUT_TIME);



		nt += lnt;

		spin_lock_irqsave(&intf->xmit_msgs_lock, flags);

		if (watch_mask != intf->last_watch_mask &&

					intf->handlers->set_need_watch)

			intf->handlers->set_need_watch(intf->send_info,

						       watch_mask);

		intf->last_watch_mask = watch_mask;

		spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags);

	}

	srcu_read_unlock(&ipmi_interfaces_srcu, index);



	if (nt)

	if (watch_mask)

		mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);

}

drivers/char/ipmi/ipmi_si_intf.c

+4 −1
Original line number Diff line number Diff line
@@ -1060,10 +1060,13 @@ static void request_events(void *send_info) 
	atomic_set(&smi_info->req_events, 1);

}



static void set_need_watch(void *send_info, bool enable)

static void set_need_watch(void *send_info, unsigned int watch_mask)

{

	struct smi_info *smi_info = send_info;

	unsigned long flags;

	int enable;



	enable = !!(watch_mask & ~IPMI_WATCH_MASK_INTERNAL);



	atomic_set(&smi_info->need_watch, enable);

	spin_lock_irqsave(&smi_info->si_lock, flags);

drivers/char/ipmi/ipmi_ssif.c

+16 −10
Original line number Diff line number Diff line
@@ -93,8 +93,8 @@ 
/*

 * Timeout for the watch, only used for get flag timer.

 */

#define SSIF_WATCH_TIMEOUT_MSEC	   100

#define SSIF_WATCH_TIMEOUT_JIFFIES msecs_to_jiffies(SSIF_WATCH_TIMEOUT_MSEC)

#define SSIF_WATCH_MSG_TIMEOUT		msecs_to_jiffies(10)

#define SSIF_WATCH_WATCHDOG_TIMEOUT	msecs_to_jiffies(250)



enum ssif_intf_state {

	SSIF_NORMAL,
@@ -276,7 +276,7 @@ struct ssif_info { 
	struct timer_list retry_timer;

	int retries_left;



	bool need_watch;		/* Need to look for flags? */

	long watch_timeout;		/* Timeout for flags check, 0 if off. */

	struct timer_list watch_timer;	/* Flag fetch timer. */



	/* Info from SSIF cmd */
@@ -578,9 +578,9 @@ static void watch_timeout(struct timer_list *t) 
		return;



	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);

	if (ssif_info->need_watch) {

	if (ssif_info->watch_timeout) {

		mod_timer(&ssif_info->watch_timer,

			  jiffies + SSIF_WATCH_TIMEOUT_JIFFIES);

			  jiffies + ssif_info->watch_timeout);

		if (SSIF_IDLE(ssif_info)) {

			start_flag_fetch(ssif_info, flags); /* Releases lock */

			return;
@@ -1121,17 +1121,23 @@ static void request_events(void *send_info) 
 * Upper layer is changing the flag saying whether we need to request

 * flags periodically or not.

 */

static void ssif_set_need_watch(void *send_info, bool enable)

static void ssif_set_need_watch(void *send_info, unsigned int watch_mask)

{

	struct ssif_info *ssif_info = (struct ssif_info *) send_info;

	unsigned long oflags, *flags;

	long timeout = 0;



	if (watch_mask & IPMI_WATCH_MASK_CHECK_MESSAGES)

		timeout = SSIF_WATCH_MSG_TIMEOUT;

	else if (watch_mask & ~IPMI_WATCH_MASK_INTERNAL)

		timeout = SSIF_WATCH_WATCHDOG_TIMEOUT;



	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);

	if (enable != ssif_info->need_watch) {

		ssif_info->need_watch = enable;

		if (ssif_info->need_watch)

	if (timeout != ssif_info->watch_timeout) {

		ssif_info->watch_timeout = timeout;

		if (ssif_info->watch_timeout)

			mod_timer(&ssif_info->watch_timer,

				  jiffies + SSIF_WATCH_TIMEOUT_JIFFIES);

				  jiffies + ssif_info->watch_timeout);

	}

	ipmi_ssif_unlock_cond(ssif_info, flags);

}

include/linux/ipmi_smi.h

+29 −7
Original line number Diff line number Diff line
@@ -30,6 +30,17 @@ struct device; 
/* Structure for the low-level drivers. */

struct ipmi_smi;



/*

 * Flags for set_check_watch() below.  Tells if the SMI should be

 * waiting for watchdog timeouts, commands and/or messages.  There is

 * also an internal flag for the message handler, SMIs should ignore

 * it.

 */

#define IPMI_WATCH_MASK_INTERNAL	(1 << 0)

#define IPMI_WATCH_MASK_CHECK_MESSAGES	(1 << 1)

#define IPMI_WATCH_MASK_CHECK_WATCHDOG	(1 << 2)

#define IPMI_WATCH_MASK_CHECK_COMMANDS	(1 << 3)



/*

 * Messages to/from the lower layer.  The smi interface will take one

 * of these to send. After the send has occurred and a response has
@@ -55,8 +66,16 @@ struct ipmi_smi_msg { 
	int           rsp_size;

	unsigned char rsp[IPMI_MAX_MSG_LENGTH];



	/* Will be called when the system is done with the message

	   (presumably to free it). */

	/*

	 * There should be a response message coming back in the BMC

	 * message queue.

	 */

	bool needs_response;



	/*

	 * Will be called when the system is done with the message

	 * (presumably to free it).

	 */

	void (*done)(struct ipmi_smi_msg *msg);

};
@@ -105,12 +124,15 @@ struct ipmi_smi_handlers { 


	/*

	 * Called by the upper layer when some user requires that the

	 * interface watch for events, received messages, watchdog

	 * pretimeouts, or not.  Used by the SMI to know if it should

	 * watch for these.  This may be NULL if the SMI does not

	 * implement it.

	 * interface watch for received messages and watchdog

	 * pretimeouts (basically do a "Get Flags", or not.  Used by

	 * the SMI to know if it should watch for these.  This may be

	 * NULL if the SMI does not implement it.  watch_mask is from

	 * IPMI_WATCH_MASK_xxx above.  The interface should run slower

	 * timeouts for just watchdog checking or faster timeouts when

	 * waiting for the message queue.

	 */

	void (*set_need_watch)(void *send_info, bool enable);

	void (*set_need_watch)(void *send_info, unsigned int watch_mask);



	/*

	 * Called when flushing all pending messages.

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