ipmi_msghandler.c

一个2.4.21版本的嵌入式linux内核

   be freed or requeued. */
static int handle_new_recv_msg(ipmi_smi_t          intf,
			       struct ipmi_smi_msg *msg)
{
	int requeue;

	if (msg->rsp_size < 2) {
		/* Message is too small to be correct. */
		requeue = 0;
	} else if (msg->rsp[1] == IPMI_GET_MSG_CMD) {
#if DEBUG_MSGING
		int m;
		printk("Response:");
		for (m=0; m<msg->rsp_size; m++)
			printk(" %2.2x", msg->rsp[m]);
		printk("\n");
#endif
		/* It's from the receive queue. */
		if (msg->rsp[4] & 0x04) {
			/* It's a response, so find the
			   requesting message and send it up. */
			requeue = handle_get_msg_rsp(intf, msg);
		} else {
			/* It's a command to the SMS from some other
			   entity.  Handle that. */
			requeue = handle_get_msg_cmd(intf, msg);
		}
	} else if (msg->rsp[1] == IPMI_READ_EVENT_MSG_BUFFER_CMD) {
		/* It's an asyncronous event. */
		requeue = handle_read_event_rsp(intf, msg);
	} else {
		/* It's a response from the local BMC. */
		requeue = handle_bmc_rsp(intf, msg);
	}

	return requeue;
}

/* Handle a new message from the lower layer. */
void ipmi_smi_msg_received(ipmi_smi_t          intf,
			   struct ipmi_smi_msg *msg)
{
	unsigned long flags;
	int           rv;


	/* Lock the user lock so the user can't go away while we are
	   working on it. */
	read_lock(&(intf->users_lock));

	if ((msg->data_size >= 2) && (msg->data[1] == IPMI_SEND_MSG_CMD)) {
		/* This is the local response to a send, start the
                   timer for these. */
		intf_start_seq_timer(intf, msg->msgid);
		ipmi_free_smi_msg(msg);
		goto out_unlock;
	}

	/* To preserve message order, if the list is not empty, we
           tack this message onto the end of the list. */
	spin_lock_irqsave(&(intf->waiting_msgs_lock), flags);
	if (!list_empty(&(intf->waiting_msgs))) {
		list_add_tail(&(msg->link), &(intf->waiting_msgs));
		spin_unlock(&(intf->waiting_msgs_lock));
		goto out_unlock;
	}
	spin_unlock_irqrestore(&(intf->waiting_msgs_lock), flags);
		
	rv = handle_new_recv_msg(intf, msg);
	if (rv > 0) {
		/* Could not handle the message now, just add it to a
                   list to handle later. */
		spin_lock(&(intf->waiting_msgs_lock));
		list_add_tail(&(msg->link), &(intf->waiting_msgs));
		spin_unlock(&(intf->waiting_msgs_lock));
	} else if (rv == 0) {
		ipmi_free_smi_msg(msg);
	}

 out_unlock:
	read_unlock(&(intf->users_lock));
}

void ipmi_smi_watchdog_pretimeout(ipmi_smi_t intf)
{
	struct list_head *entry;
	ipmi_user_t      user;

	read_lock(&(intf->users_lock));
	list_for_each(entry, &(intf->users)) {
		user = list_entry(entry, struct ipmi_user, link);

		if (! user->handler->ipmi_watchdog_pretimeout)
			continue;

		user->handler->ipmi_watchdog_pretimeout(user->handler_data);
	}
	read_unlock(&(intf->users_lock));
}

static void
handle_msg_timeout(struct ipmi_recv_msg *msg)
{
	msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
	msg->msg_data[0] = IPMI_TIMEOUT_COMPLETION_CODE;
	msg->msg.netfn |= 1; /* Convert to a response. */
	msg->msg.data_len = 1;
	msg->msg.data = msg->msg_data;
	deliver_response(msg);
}

static void
send_from_recv_msg(ipmi_smi_t intf, struct ipmi_recv_msg *recv_msg,
		   struct ipmi_smi_msg *smi_msg,
		   unsigned char seq, long seqid)
{
	if (!smi_msg)
		smi_msg = ipmi_alloc_smi_msg();
	if (!smi_msg)
		/* If we can't allocate the message, then just return, we
		   get 4 retries, so this should be ok. */
		return;

	memcpy(smi_msg->data, recv_msg->msg.data, recv_msg->msg.data_len);
	smi_msg->data_size = recv_msg->msg.data_len;
	smi_msg->msgid = STORE_SEQ_IN_MSGID(seq, seqid);
		
	/* Send the new message.  We send with a zero priority.  It
	   timed out, I doubt time is that critical now, and high
	   priority messages are really only for messages to the local
	   MC, which don't get resent. */
	intf->handlers->sender(intf->send_info, smi_msg, 0);

#if DEBUG_MSGING
	{
		int m;
		printk("Resend: ");
		for (m=0; m<smi_msg->data_size; m++)
			printk(" %2.2x", smi_msg->data[m]);
		printk("\n");
	}
#endif
}

static void
ipmi_timeout_handler(long timeout_period)
{
	ipmi_smi_t           intf;
	struct list_head     timeouts;
	struct ipmi_recv_msg *msg;
	struct ipmi_smi_msg  *smi_msg;
	unsigned long        flags;
	struct list_head     *entry, *entry2;
	int                  i, j;

	INIT_LIST_HEAD(&timeouts);

	spin_lock(&interfaces_lock);
	for (i=0; i<MAX_IPMI_INTERFACES; i++) {
		intf = ipmi_interfaces[i];
		if (intf == NULL)
			continue;

		read_lock(&(intf->users_lock));

		/* See if any waiting messages need to be processed. */
		spin_lock_irqsave(&(intf->waiting_msgs_lock), flags);
		list_for_each_safe(entry, entry2, &(intf->waiting_msgs)) {
			smi_msg = list_entry(entry, struct ipmi_smi_msg, link);
			if (! handle_new_recv_msg(intf, smi_msg)) {
				list_del(entry);
				ipmi_free_smi_msg(smi_msg);
			} else {
				/* To preserve message order, quit if we
				   can't handle a message. */
				break;
			}
		}
		spin_unlock_irqrestore(&(intf->waiting_msgs_lock), flags);

		/* Go through the seq table and find any messages that
		   have timed out, putting them in the timeouts
		   list. */
		spin_lock_irqsave(&(intf->seq_lock), flags);
		for (j=0; j<IPMI_IPMB_NUM_SEQ; j++) {
			struct seq_table *ent = &(intf->seq_table[j]);
			if (!ent->inuse)
				continue;

			ent->timeout -= timeout_period;
			if (ent->timeout > 0)
				continue;

			if (ent->retries_left == 0) {
				/* The message has used all its retries. */
				ent->inuse = 0;
				msg = ent->recv_msg;
				list_add_tail(&(msg->link), &timeouts);
			} else {
				/* More retries, send again. */

				/* Start with the max timer, set to normal
				   timer after the message is sent. */
				ent->timeout = MAX_MSG_TIMEOUT;
				ent->retries_left--;
				send_from_recv_msg(intf, ent->recv_msg, NULL,
						   j, ent->seqid);
			}
		}
		spin_unlock_irqrestore(&(intf->seq_lock), flags);

		list_for_each_safe(entry, entry2, &timeouts) {
			msg = list_entry(entry, struct ipmi_recv_msg, link);
			handle_msg_timeout(msg);
		}

		read_unlock(&(intf->users_lock));
	}
	spin_unlock(&interfaces_lock);
}

static void ipmi_request_event(void)
{
	ipmi_smi_t intf;
	int        i;

	spin_lock(&interfaces_lock);
	for (i=0; i<MAX_IPMI_INTERFACES; i++) {
		intf = ipmi_interfaces[i];
		if (intf == NULL)
			continue;

		intf->handlers->request_events(intf->send_info);
	}
	spin_unlock(&interfaces_lock);
}

static struct timer_list ipmi_timer;

/* Call every 100 ms. */
#define IPMI_TIMEOUT_TIME	100
#define IPMI_TIMEOUT_JIFFIES	(IPMI_TIMEOUT_TIME/(1000/HZ))

/* Request events from the queue every second.  Hopefully, in the
   future, IPMI will add a way to know immediately if an event is
   in the queue. */
#define IPMI_REQUEST_EV_TIME	(1000 / (IPMI_TIMEOUT_TIME))

static volatile int stop_operation = 0;
static volatile int timer_stopped = 0;
static unsigned int ticks_to_req_ev = IPMI_REQUEST_EV_TIME;

static void ipmi_timeout(unsigned long data)
{
	if (stop_operation) {
		timer_stopped = 1;
		return;
	}

	ticks_to_req_ev--;
	if (ticks_to_req_ev == 0) {
		ipmi_request_event();
		ticks_to_req_ev = IPMI_REQUEST_EV_TIME;
	}

	ipmi_timeout_handler(IPMI_TIMEOUT_TIME);

	ipmi_timer.expires += IPMI_TIMEOUT_JIFFIES;
	add_timer(&ipmi_timer);
}


static atomic_t smi_msg_inuse_count = ATOMIC_INIT(0);
static atomic_t recv_msg_inuse_count = ATOMIC_INIT(0);

/* FIXME - convert these to slabs. */
static void free_smi_msg(struct ipmi_smi_msg *msg)
{
	atomic_dec(&smi_msg_inuse_count);
	kfree(msg);
}

struct ipmi_smi_msg *ipmi_alloc_smi_msg(void)
{
	struct ipmi_smi_msg *rv;
	rv = kmalloc(sizeof(struct ipmi_smi_msg), GFP_ATOMIC);
	if (rv) {
		rv->done = free_smi_msg;
		atomic_inc(&smi_msg_inuse_count);
	}
	return rv;
}

static void free_recv_msg(struct ipmi_recv_msg *msg)
{
	atomic_dec(&recv_msg_inuse_count);
	kfree(msg);
}

struct ipmi_recv_msg *ipmi_alloc_recv_msg(void)
{
	struct ipmi_recv_msg *rv;

	rv = kmalloc(sizeof(struct ipmi_recv_msg), GFP_ATOMIC);
	if (rv) {
		rv->done = free_recv_msg;
		atomic_inc(&recv_msg_inuse_count);
	}
	return rv;
}

#ifdef CONFIG_IPMI_PANIC_EVENT

static void dummy_smi_done_handler(struct ipmi_smi_msg *msg)
{
}

static void dummy_recv_done_handler(struct ipmi_recv_msg *msg)
{
}

static void send_panic_events(void)
{
	struct ipmi_msg                   msg;
	ipmi_smi_t                        intf;
	unsigned char                     data[8];
	int                               i;
	struct ipmi_system_interface_addr addr;
	struct ipmi_smi_msg               smi_msg;
	struct ipmi_recv_msg              recv_msg;

	addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
	addr.channel = IPMI_BMC_CHANNEL;

	/* Fill in an event telling that we have failed. */
	msg.netfn = 0x04; /* Sensor or Event. */
	msg.cmd = 2; /* Platform event command. */
	msg.data = data;
	msg.data_len = 8;
	data[0] = 0x21; /* Kernel generator ID, IPMI table 5-4 */
	data[1] = 0x03; /* This is for IPMI 1.0. */
	data[2] = 0x20; /* OS Critical Stop, IPMI table 36-3 */
	data[4] = 0x6f; /* Sensor specific, IPMI table 36-1 */
	data[5] = 0xa1; /* Runtime stop OEM bytes 2 & 3. */

	/* These used to have the first three bytes of the panic string,
	   but not only is that not terribly useful, it's not available
	   any more. */
	data[3] = 0;
	data[6] = 0;
	data[7] = 0;

	smi_msg.done = dummy_smi_done_handler;
	recv_msg.done = dummy_recv_done_handler;

	/* For every registered interface, send the event. */
	for (i=0; i<MAX_IPMI_INTERFACES; i++) {
		intf = ipmi_interfaces[i];
		if (intf == NULL)
			continue;

		intf->handlers->set_run_to_completion(intf->send_info, 1);
		i_ipmi_request(NULL,
			       intf,
			       (struct ipmi_addr *) &addr,
			       0,
			       &msg,
			       &smi_msg,
			       &recv_msg,
			       0,
			       intf->my_address,
			       intf->my_lun);
	}
}
#endif /* CONFIG_IPMI_PANIC_EVENT */

static int has_paniced = 0;

static int panic_event(struct notifier_block *this,
		       unsigned long         event,
                       void                  *ptr)
{
	int        i;
	ipmi_smi_t intf;

	if (has_paniced)
		return NOTIFY_DONE;
	has_paniced = 1;

	/* For every registered interface, set it to run to completion. */
	for (i=0; i<MAX_IPMI_INTERFACES; i++) {
		intf = ipmi_interfaces[i];
		if (intf == NULL)
			continue;

		intf->handlers->set_run_to_completion(intf->send_info, 1);
	}

#ifdef CONFIG_IPMI_PANIC_EVENT
	send_panic_events();
#endif

	return NOTIFY_DONE;
}

static struct notifier_block panic_block = {
	panic_event,
	NULL,
	200   /* priority: INT_MAX >= x >= 0 */
};


static __init int ipmi_init_msghandler(void)
{
	int i;

	if (initialized)
		return 0;

	for (i=0; i<MAX_IPMI_INTERFACES; i++) {
		ipmi_interfaces[i] = NULL;
	}

	init_timer(&ipmi_timer);
	ipmi_timer.data = 0;
	ipmi_timer.function = ipmi_timeout;
	ipmi_timer.expires = jiffies + IPMI_TIMEOUT_JIFFIES;
	add_timer(&ipmi_timer);

	notifier_chain_register(&panic_notifier_list, &panic_block);

	initialized = 1;

	printk(KERN_INFO "ipmi: message handler initialized\n");

	return 0;
}

static __exit void cleanup_ipmi(void)
{
	int count;

	if (!initialized)
		return;

	notifier_chain_unregister(&panic_notifier_list, &panic_block);

	/* This can't be called if any interfaces exist, so no worry about
	   shutting down the interfaces. */

	/* Tell the timer to stop, then wait for it to stop.  This avoids
	   problems with race conditions removing the timer here. */
	stop_operation = 1;
	while (!timer_stopped) {
		schedule_timeout(1);
	}

	initialized = 0;

	/* Check for buffer leaks. */
	count = atomic_read(&smi_msg_inuse_count);
	if (count != 0)
		printk("ipmi_msghandler: SMI message count %d at exit\n",
		       count);
	count = atomic_read(&recv_msg_inuse_count);
	if (count != 0)
		printk("ipmi_msghandler: recv message count %d at exit\n",
		       count);
}
module_exit(cleanup_ipmi);

module_init(ipmi_init_msghandler);
MODULE_LICENSE("GPL");

EXPORT_SYMBOL(ipmi_alloc_recv_msg);
EXPORT_SYMBOL(ipmi_create_user);
EXPORT_SYMBOL(ipmi_destroy_user);
EXPORT_SYMBOL(ipmi_get_version);
EXPORT_SYMBOL(ipmi_request);
EXPORT_SYMBOL(ipmi_request_supply_msgs);
EXPORT_SYMBOL(ipmi_request_with_source);
EXPORT_SYMBOL(ipmi_register_smi);
EXPORT_SYMBOL(ipmi_unregister_smi);
EXPORT_SYMBOL(ipmi_register_for_cmd);
EXPORT_SYMBOL(ipmi_unregister_for_cmd);
EXPORT_SYMBOL(ipmi_smi_msg_received);
EXPORT_SYMBOL(ipmi_smi_watchdog_pretimeout);
EXPORT_SYMBOL(ipmi_alloc_smi_msg);
EXPORT_SYMBOL(ipmi_register_all_cmd_rcvr);
EXPORT_SYMBOL(ipmi_unregister_all_cmd_rcvr);
EXPORT_SYMBOL(ipmi_addr_length);
EXPORT_SYMBOL(ipmi_validate_addr);
EXPORT_SYMBOL(ipmi_set_gets_events);
EXPORT_SYMBOL(ipmi_addr_equal);
EXPORT_SYMBOL(ipmi_smi_watcher_register);
EXPORT_SYMBOL(ipmi_smi_watcher_unregister);
EXPORT_SYMBOL(ipmi_set_my_address);
EXPORT_SYMBOL(ipmi_get_my_address);
EXPORT_SYMBOL(ipmi_set_my_LUN);
EXPORT_SYMBOL(ipmi_get_my_LUN);