ipmi_msghandler.c

一个2.4.21版本的嵌入式linux内核

{
	return i_ipmi_request(user,
			      user->intf,
			      addr,
			      msgid,
			      msg,
			      NULL, NULL,
			      priority,
			      source_address,
			      source_lun);
}

int ipmi_register_smi(struct ipmi_smi_handlers *handlers,
		      void		       *send_info,
		      unsigned char            version_major,
		      unsigned char            version_minor,
		      ipmi_smi_t               *intf)
{
	int              i, j;
	int              rv;
	ipmi_smi_t       new_intf;
	struct list_head *entry;
	unsigned long    flags;


	/* Make sure the driver is actually initialized, this handles
	   problems with initialization order. */
	if (!initialized) {
		rv = ipmi_init_msghandler();
		if (rv)
			return rv;
		/* The init code doesn't return an error if it was turned
		   off, but it won't initialize.  Check that. */
		if (!initialized)
			return -ENODEV;
	}

	new_intf = kmalloc(sizeof(*new_intf), GFP_KERNEL);
	if (!new_intf)
		return -ENOMEM;

	rv = -ENOMEM;

	down_write(&interfaces_sem);
	for (i=0; i<MAX_IPMI_INTERFACES; i++) {
		if (ipmi_interfaces[i] == NULL) {
			new_intf->version_major = version_major;
			new_intf->version_minor = version_minor;
			new_intf->my_address = IPMI_BMC_SLAVE_ADDR;
			new_intf->my_lun = 2;  /* the SMS LUN. */
			rwlock_init(&(new_intf->users_lock));
			INIT_LIST_HEAD(&(new_intf->users));
			new_intf->handlers = handlers;
			new_intf->send_info = send_info;
			spin_lock_init(&(new_intf->seq_lock));
			for (j=0; j<IPMI_IPMB_NUM_SEQ; j++) {
				new_intf->seq_table[j].inuse = 0;
				new_intf->seq_table[j].seqid = 0;
			}
			new_intf->curr_seq = 0;
			spin_lock_init(&(new_intf->waiting_msgs_lock));
			INIT_LIST_HEAD(&(new_intf->waiting_msgs));
			spin_lock_init(&(new_intf->events_lock));
			INIT_LIST_HEAD(&(new_intf->waiting_events));
			new_intf->waiting_events_count = 0;
			rwlock_init(&(new_intf->cmd_rcvr_lock));
			INIT_LIST_HEAD(&(new_intf->cmd_rcvrs));
			new_intf->all_cmd_rcvr = NULL;

			spin_lock_irqsave(&interfaces_lock, flags);
			ipmi_interfaces[i] = new_intf;
			spin_unlock_irqrestore(&interfaces_lock, flags);

			rv = 0;
			*intf = new_intf;
			break;
		}
	}

	/* We convert to a read semaphore here.  It's possible the
	   interface was removed between the calls, we have to recheck
	   afterwards. */
	up_write(&interfaces_sem);
	down_read(&interfaces_sem);

	if (ipmi_interfaces[i] != new_intf)
		/* Well, it went away.  Just return. */
		goto out;

	if (rv == 0) {
		/* Call all the watcher interfaces to tell them that a
		   new interface is available. */
		down_read(&smi_watchers_sem);
		list_for_each(entry, &smi_watchers) {
			struct ipmi_smi_watcher *w;
			w = list_entry(entry, struct ipmi_smi_watcher, link);
			w->new_smi(i);
		}
		up_read(&smi_watchers_sem);
	}

 out:
	up_read(&interfaces_sem);

	if (rv)
		kfree(new_intf);

	return rv;
}

static void free_recv_msg_list(struct list_head *q)
{
	struct list_head     *entry, *entry2;
	struct ipmi_recv_msg *msg;

	list_for_each_safe(entry, entry2, q) {
		msg = list_entry(entry, struct ipmi_recv_msg, link);
		list_del(entry);
		ipmi_free_recv_msg(msg);
	}
}

static void free_cmd_rcvr_list(struct list_head *q)
{
	struct list_head *entry, *entry2;
	struct cmd_rcvr  *rcvr;

	list_for_each_safe(entry, entry2, q) {
		rcvr = list_entry(entry, struct cmd_rcvr, link);
		list_del(entry);
		kfree(rcvr);
	}
}

static void clean_up_interface_data(ipmi_smi_t intf)
{
	int i;

	free_recv_msg_list(&(intf->waiting_msgs));
	free_recv_msg_list(&(intf->waiting_events));
	free_cmd_rcvr_list(&(intf->cmd_rcvrs));

	for (i=0; i<IPMI_IPMB_NUM_SEQ; i++) {
		if ((intf->seq_table[i].inuse)
		    && (intf->seq_table[i].recv_msg))
		{
			ipmi_free_recv_msg(intf->seq_table[i].recv_msg);
		}	
	}
}

int ipmi_unregister_smi(ipmi_smi_t intf)
{
	int              rv = -ENODEV;
	int              i;
	struct list_head *entry;
	unsigned long    flags;

	down_write(&interfaces_sem);
	if (list_empty(&(intf->users)))
	{
		for (i=0; i<MAX_IPMI_INTERFACES; i++) {
			if (ipmi_interfaces[i] == intf) {
				spin_lock_irqsave(&interfaces_lock, flags);
				ipmi_interfaces[i] = NULL;
				clean_up_interface_data(intf);
				spin_unlock_irqrestore(&interfaces_lock,flags);
				kfree(intf);
				rv = 0;
				goto out_call_watcher;
			}
		}
	} else {
		rv = -EBUSY;
	}
	up_write(&interfaces_sem);

	return rv;

 out_call_watcher:
	/* Convert to a read semaphore so callbacks don't bite us. */
	up_write(&interfaces_sem);
	down_read(&interfaces_sem);

	/* Call all the watcher interfaces to tell them that
	   an interface is gone. */
	down_read(&smi_watchers_sem);
	list_for_each(entry, &smi_watchers) {
		struct ipmi_smi_watcher *w;
		w = list_entry(entry,
			       struct ipmi_smi_watcher,
			       link);
		w->smi_gone(i);
	}
	up_read(&smi_watchers_sem);
	up_read(&interfaces_sem);
	return 0;
}

static int handle_get_msg_rsp(ipmi_smi_t          intf,
			      struct ipmi_smi_msg *msg)
{
	struct ipmi_ipmb_addr ipmb_addr;
	struct ipmi_recv_msg  *recv_msg;

	
	if (msg->rsp_size < 11)
		/* Message not big enough, just ignore it. */
		return 0;

	if (msg->rsp[2] != 0)
		/* An error getting the response, just ignore it. */
		return 0;

	ipmb_addr.addr_type = IPMI_IPMB_ADDR_TYPE;
	ipmb_addr.slave_addr = msg->rsp[6];
	ipmb_addr.channel = msg->rsp[3] & 0x0f;
	ipmb_addr.lun = msg->rsp[7] & 3;

	/* It's a response from a remote entity.  Look up the sequence
	   number and handle the response. */
	if (intf_find_seq(intf,
			  msg->rsp[7] >> 2,
			  msg->rsp[3] & 0x0f,
			  msg->rsp[8],
			  (msg->rsp[4] >> 2) & (~1),
			  (struct ipmi_addr *) &(ipmb_addr),
			  &recv_msg))
	{
		/* We were unable to find the sequence number,
		   so just nuke the message. */
		return 0;
	}

	memcpy(recv_msg->msg_data,
	       &(msg->rsp[9]),
	       msg->rsp_size - 9);
	/* THe other fields matched, so no need to set them, except
           for netfn, which needs to be the response that was
           returned, not the request value. */
	recv_msg->msg.netfn = msg->rsp[4] >> 2;
	recv_msg->msg.data = recv_msg->msg_data;
	recv_msg->msg.data_len = msg->rsp_size - 10;
	recv_msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
	deliver_response(recv_msg);

	return 0;
}

static int handle_get_msg_cmd(ipmi_smi_t          intf,
			      struct ipmi_smi_msg *msg)
{
	struct list_head *entry;
	struct cmd_rcvr       *rcvr;
	int              rv = 0;
	unsigned char    netfn;
	unsigned char    cmd;
	ipmi_user_t      user = NULL;
	struct ipmi_ipmb_addr *ipmb_addr;
	struct ipmi_recv_msg  *recv_msg;

	if (msg->rsp_size < 10)
		/* Message not big enough, just ignore it. */
		return 0;

	if (msg->rsp[2] != 0) {
		/* An error getting the response, just ignore it. */
		return 0;
	}

	netfn = msg->rsp[4] >> 2;
	cmd = msg->rsp[8];

	read_lock(&(intf->cmd_rcvr_lock));
	
	if (intf->all_cmd_rcvr) {
		user = intf->all_cmd_rcvr;
	} else {
		/* Find the command/netfn. */
		list_for_each(entry, &(intf->cmd_rcvrs)) {
			rcvr = list_entry(entry, struct cmd_rcvr, link);
			if ((rcvr->netfn == netfn) && (rcvr->cmd == cmd)) {
				user = rcvr->user;
				break;
			}
		}
	}
	read_unlock(&(intf->cmd_rcvr_lock));

	if (user == NULL) {
		/* We didn't find a user, deliver an error response. */
		msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
		msg->data[1] = IPMI_SEND_MSG_CMD;
		msg->data[2] = msg->rsp[3];
		msg->data[3] = msg->rsp[6];
                msg->data[4] = ((netfn + 1) << 2) | (msg->rsp[7] & 0x3);
		msg->data[5] = ipmb_checksum(&(msg->data[3]), 2);
		msg->data[6] = intf->my_address;
                /* rqseq/lun */
                msg->data[7] = (msg->rsp[7] & 0xfc) | (msg->rsp[4] & 0x3);
		msg->data[8] = msg->rsp[8]; /* cmd */
		msg->data[9] = IPMI_INVALID_CMD_COMPLETION_CODE;
		msg->data[10] = ipmb_checksum(&(msg->data[6]), 4);
		msg->data_size = 11;

		intf->handlers->sender(intf->send_info, msg, 0);

		rv = -1; /* We used the message, so return the value that
			    causes it to not be freed or queued. */
	} else {
		/* Deliver the message to the user. */
		recv_msg = ipmi_alloc_recv_msg();
		if (! recv_msg) {
			/* We couldn't allocate memory for the
                           message, so requeue it for handling
                           later. */
			rv = 1;
		} else {
			ipmb_addr = (struct ipmi_ipmb_addr *) &recv_msg->addr;
			ipmb_addr->addr_type = IPMI_IPMB_ADDR_TYPE;
			ipmb_addr->slave_addr = msg->rsp[6];
			ipmb_addr->lun = msg->rsp[7] & 3;
			ipmb_addr->channel = msg->rsp[3];

			recv_msg->user = user;
			recv_msg->recv_type = IPMI_CMD_RECV_TYPE;
			recv_msg->msgid = msg->rsp[7] >> 2;
			recv_msg->msg.netfn = msg->rsp[4] >> 2;
			recv_msg->msg.cmd = msg->rsp[8];
			recv_msg->msg.data = recv_msg->msg_data;
			recv_msg->msg.data_len = msg->rsp_size - 10;
			memcpy(recv_msg->msg_data,
			       &(msg->rsp[9]),
			       msg->rsp_size - 10);
			deliver_response(recv_msg);
		}
	}

	return rv;
}

static void copy_event_into_recv_msg(struct ipmi_recv_msg *recv_msg,
				     struct ipmi_smi_msg  *msg)
{
	struct ipmi_system_interface_addr *smi_addr;
	
	recv_msg->msgid = 0;
	smi_addr = (struct ipmi_system_interface_addr *) &(recv_msg->addr);
	smi_addr->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
	smi_addr->channel = IPMI_BMC_CHANNEL;
	smi_addr->lun = msg->rsp[0] & 3;
	recv_msg->recv_type = IPMI_ASYNC_EVENT_RECV_TYPE;
	recv_msg->msg.netfn = msg->rsp[0] >> 2;
	recv_msg->msg.cmd = msg->rsp[1];
	memcpy(recv_msg->msg_data, &(msg->rsp[3]), msg->rsp_size - 3);
	recv_msg->msg.data = recv_msg->msg_data;
	recv_msg->msg.data_len = msg->rsp_size - 3;
}

/* This will be called with the intf->users_lock read-locked, so no need
   to do that here. */
static int handle_read_event_rsp(ipmi_smi_t          intf,
				 struct ipmi_smi_msg *msg)
{
	struct ipmi_recv_msg *recv_msg;
	struct list_head     msgs;
	struct list_head     *entry, *entry2;
	ipmi_user_t          user;
	int                  rv = 0;
	int                  deliver_count = 0;
	unsigned long        flags;

	if (msg->rsp_size < 19) {
		/* Message is too small to be an IPMB event. */
		return 0;
	}

	if (msg->rsp[2] != 0) {
		/* An error getting the event, just ignore it. */
		return 0;
	}

	INIT_LIST_HEAD(&msgs);

	spin_lock_irqsave(&(intf->events_lock), flags);

	/* Allocate and fill in one message for every user that is getting
	   events. */
	list_for_each(entry, &(intf->users)) {
		user = list_entry(entry, struct ipmi_user, link);

		if (! user->gets_events)
			continue;

		recv_msg = ipmi_alloc_recv_msg();
		if (! recv_msg) {
			list_for_each_safe(entry, entry2, &msgs) {
				recv_msg = list_entry(entry,
						      struct ipmi_recv_msg,
						      link);
				list_del(entry);
				ipmi_free_recv_msg(recv_msg);
			}
			/* We couldn't allocate memory for the
                           message, so requeue it for handling
                           later. */
			rv = 1;
			goto out;
		}

		deliver_count++;

		copy_event_into_recv_msg(recv_msg, msg);
		recv_msg->user = user;
		list_add_tail(&(recv_msg->link), &msgs);
	}

	if (deliver_count) {
		/* Now deliver all the messages. */
		list_for_each_safe(entry, entry2, &msgs) {
			recv_msg = list_entry(entry,
					      struct ipmi_recv_msg,
					      link);
			list_del(entry);
			deliver_response(recv_msg);
		}
	} else if (intf->waiting_events_count < MAX_EVENTS_IN_QUEUE) {
		/* No one to receive the message, put it in queue if there's
		   not already too many things in the queue. */
		recv_msg = ipmi_alloc_recv_msg();
		if (! recv_msg) {
			/* We couldn't allocate memory for the
                           message, so requeue it for handling
                           later. */
			rv = 1;
			goto out;
		}

		copy_event_into_recv_msg(recv_msg, msg);
		list_add_tail(&(recv_msg->link), &(intf->waiting_events));
	} else {
		/* There's too many things in the queue, discard this
		   message. */
		printk(KERN_WARNING "ipmi: Event queue full, discarding an"
		       " incoming event\n");
	}

 out:
	spin_unlock_irqrestore(&(intf->events_lock), flags);

	return rv;
}

static int handle_bmc_rsp(ipmi_smi_t          intf,
			  struct ipmi_smi_msg *msg)
{
	struct ipmi_recv_msg *recv_msg;
	int                  found = 0;
	struct list_head     *entry;

	recv_msg = (struct ipmi_recv_msg *) msg->user_data;

	/* Make sure the user still exists. */
	list_for_each(entry, &(intf->users)) {
		if (list_entry(entry, struct ipmi_user, link)
		    == recv_msg->user)
		{
			/* Found it, so we can deliver it */
			found = 1;
			break;
		}
	}

	if (!found) {
		/* The user for the message went away, so give up. */
		ipmi_free_recv_msg(recv_msg);
	} else {
		struct ipmi_system_interface_addr *smi_addr;

		recv_msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
		recv_msg->msgid = msg->msgid;
		smi_addr = ((struct ipmi_system_interface_addr *)
			    &(recv_msg->addr));
		smi_addr->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
		smi_addr->channel = IPMI_BMC_CHANNEL;
		smi_addr->lun = msg->rsp[0] & 3;
		recv_msg->msg.netfn = msg->rsp[0] >> 2;
		recv_msg->msg.cmd = msg->rsp[1];
		memcpy(recv_msg->msg_data,
		       &(msg->rsp[2]),
		       msg->rsp_size - 2);
		recv_msg->msg.data = recv_msg->msg_data;
		recv_msg->msg.data_len = msg->rsp_size - 2;
		deliver_response(recv_msg);
	}

	return 0;
}

/* Handle a new message.  Return 1 if the message should be requeued,
   0 if the message should be freed, or -1 if the message should not