user_mad.c

linux-2.6.15.6

	agent = ib_register_mad_agent(file->port->ib_dev, file->port->port_num,
				      ureq.qpn ? IB_QPT_GSI : IB_QPT_SMI,
				      ureq.mgmt_class ? &req : NULL,
				      ureq.rmpp_version,
				      send_handler, recv_handler, file);
	if (IS_ERR(agent)) {
		ret = PTR_ERR(agent);
		goto out;
	}

	if (put_user(agent_id,
		     (u32 __user *) (arg + offsetof(struct ib_user_mad_reg_req, id)))) {
		ret = -EFAULT;
		ib_unregister_mad_agent(agent);
		goto out;
	}

	file->agent[agent_id] = agent;
	ret = 0;

out:
	up_write(&file->port->mutex);
	return ret;
}

static int ib_umad_unreg_agent(struct ib_umad_file *file, unsigned long arg)
{
	struct ib_mad_agent *agent = NULL;
	u32 id;
	int ret = 0;

	if (get_user(id, (u32 __user *) arg))
		return -EFAULT;

	down_write(&file->port->mutex);

	if (id < 0 || id >= IB_UMAD_MAX_AGENTS || !__get_agent(file, id)) {
		ret = -EINVAL;
		goto out;
	}

	agent = file->agent[id];
	file->agent[id] = NULL;

out:
	up_write(&file->port->mutex);

	if (agent)
		ib_unregister_mad_agent(agent);

	return ret;
}

static long ib_umad_ioctl(struct file *filp, unsigned int cmd,
			  unsigned long arg)
{
	switch (cmd) {
	case IB_USER_MAD_REGISTER_AGENT:
		return ib_umad_reg_agent(filp->private_data, arg);
	case IB_USER_MAD_UNREGISTER_AGENT:
		return ib_umad_unreg_agent(filp->private_data, arg);
	default:
		return -ENOIOCTLCMD;
	}
}

static int ib_umad_open(struct inode *inode, struct file *filp)
{
	struct ib_umad_port *port;
	struct ib_umad_file *file;
	int ret = 0;

	spin_lock(&port_lock);
	port = umad_port[iminor(inode) - IB_UMAD_MINOR_BASE];
	if (port)
		kref_get(&port->umad_dev->ref);
	spin_unlock(&port_lock);

	if (!port)
		return -ENXIO;

	down_write(&port->mutex);

	if (!port->ib_dev) {
		ret = -ENXIO;
		goto out;
	}

	file = kzalloc(sizeof *file, GFP_KERNEL);
	if (!file) {
		kref_put(&port->umad_dev->ref, ib_umad_release_dev);
		ret = -ENOMEM;
		goto out;
	}

	spin_lock_init(&file->recv_lock);
	INIT_LIST_HEAD(&file->recv_list);
	init_waitqueue_head(&file->recv_wait);

	file->port = port;
	filp->private_data = file;

	list_add_tail(&file->port_list, &port->file_list);

out:
	up_write(&port->mutex);
	return ret;
}

static int ib_umad_close(struct inode *inode, struct file *filp)
{
	struct ib_umad_file *file = filp->private_data;
	struct ib_umad_device *dev = file->port->umad_dev;
	struct ib_umad_packet *packet, *tmp;
	int already_dead;
	int i;

	down_write(&file->port->mutex);

	already_dead = file->agents_dead;
	file->agents_dead = 1;

	list_for_each_entry_safe(packet, tmp, &file->recv_list, list)
		kfree(packet);

	list_del(&file->port_list);

	downgrade_write(&file->port->mutex);

	if (!already_dead)
		for (i = 0; i < IB_UMAD_MAX_AGENTS; ++i)
			if (file->agent[i])
				ib_unregister_mad_agent(file->agent[i]);

	up_read(&file->port->mutex);

	kfree(file);
	kref_put(&dev->ref, ib_umad_release_dev);

	return 0;
}

static struct file_operations umad_fops = {
	.owner 	 	= THIS_MODULE,
	.read 	 	= ib_umad_read,
	.write 	 	= ib_umad_write,
	.poll 	 	= ib_umad_poll,
	.unlocked_ioctl = ib_umad_ioctl,
	.compat_ioctl 	= ib_umad_ioctl,
	.open 	 	= ib_umad_open,
	.release 	= ib_umad_close
};

static int ib_umad_sm_open(struct inode *inode, struct file *filp)
{
	struct ib_umad_port *port;
	struct ib_port_modify props = {
		.set_port_cap_mask = IB_PORT_SM
	};
	int ret;

	spin_lock(&port_lock);
	port = umad_port[iminor(inode) - IB_UMAD_MINOR_BASE - IB_UMAD_MAX_PORTS];
	if (port)
		kref_get(&port->umad_dev->ref);
	spin_unlock(&port_lock);

	if (!port)
		return -ENXIO;

	if (filp->f_flags & O_NONBLOCK) {
		if (down_trylock(&port->sm_sem)) {
			ret = -EAGAIN;
			goto fail;
		}
	} else {
		if (down_interruptible(&port->sm_sem)) {
			ret = -ERESTARTSYS;
			goto fail;
		}
	}

	ret = ib_modify_port(port->ib_dev, port->port_num, 0, &props);
	if (ret) {
		up(&port->sm_sem);
		goto fail;
	}

	filp->private_data = port;

	return 0;

fail:
	kref_put(&port->umad_dev->ref, ib_umad_release_dev);
	return ret;
}

static int ib_umad_sm_close(struct inode *inode, struct file *filp)
{
	struct ib_umad_port *port = filp->private_data;
	struct ib_port_modify props = {
		.clr_port_cap_mask = IB_PORT_SM
	};
	int ret = 0;

	down_write(&port->mutex);
	if (port->ib_dev)
		ret = ib_modify_port(port->ib_dev, port->port_num, 0, &props);
	up_write(&port->mutex);

	up(&port->sm_sem);

	kref_put(&port->umad_dev->ref, ib_umad_release_dev);

	return ret;
}

static struct file_operations umad_sm_fops = {
	.owner 	 = THIS_MODULE,
	.open 	 = ib_umad_sm_open,
	.release = ib_umad_sm_close
};

static struct ib_client umad_client = {
	.name   = "umad",
	.add    = ib_umad_add_one,
	.remove = ib_umad_remove_one
};

static ssize_t show_ibdev(struct class_device *class_dev, char *buf)
{
	struct ib_umad_port *port = class_get_devdata(class_dev);

	if (!port)
		return -ENODEV;

	return sprintf(buf, "%s\n", port->ib_dev->name);
}
static CLASS_DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);

static ssize_t show_port(struct class_device *class_dev, char *buf)
{
	struct ib_umad_port *port = class_get_devdata(class_dev);

	if (!port)
		return -ENODEV;

	return sprintf(buf, "%d\n", port->port_num);
}
static CLASS_DEVICE_ATTR(port, S_IRUGO, show_port, NULL);

static ssize_t show_abi_version(struct class *class, char *buf)
{
	return sprintf(buf, "%d\n", IB_USER_MAD_ABI_VERSION);
}
static CLASS_ATTR(abi_version, S_IRUGO, show_abi_version, NULL);

static int ib_umad_init_port(struct ib_device *device, int port_num,
			     struct ib_umad_port *port)
{
	spin_lock(&port_lock);
	port->dev_num = find_first_zero_bit(dev_map, IB_UMAD_MAX_PORTS);
	if (port->dev_num >= IB_UMAD_MAX_PORTS) {
		spin_unlock(&port_lock);
		return -1;
	}
	set_bit(port->dev_num, dev_map);
	spin_unlock(&port_lock);

	port->ib_dev   = device;
	port->port_num = port_num;
	init_MUTEX(&port->sm_sem);
	init_rwsem(&port->mutex);
	INIT_LIST_HEAD(&port->file_list);

	port->dev = cdev_alloc();
	if (!port->dev)
		return -1;
	port->dev->owner = THIS_MODULE;
	port->dev->ops   = &umad_fops;
	kobject_set_name(&port->dev->kobj, "umad%d", port->dev_num);
	if (cdev_add(port->dev, base_dev + port->dev_num, 1))
		goto err_cdev;

	port->class_dev = class_device_create(umad_class, NULL, port->dev->dev,
					      device->dma_device,
					      "umad%d", port->dev_num);
	if (IS_ERR(port->class_dev))
		goto err_cdev;

	if (class_device_create_file(port->class_dev, &class_device_attr_ibdev))
		goto err_class;
	if (class_device_create_file(port->class_dev, &class_device_attr_port))
		goto err_class;

	port->sm_dev = cdev_alloc();
	if (!port->sm_dev)
		goto err_class;
	port->sm_dev->owner = THIS_MODULE;
	port->sm_dev->ops   = &umad_sm_fops;
	kobject_set_name(&port->sm_dev->kobj, "issm%d", port->dev_num);
	if (cdev_add(port->sm_dev, base_dev + port->dev_num + IB_UMAD_MAX_PORTS, 1))
		goto err_sm_cdev;

	port->sm_class_dev = class_device_create(umad_class, NULL, port->sm_dev->dev,
						 device->dma_device,
						 "issm%d", port->dev_num);
	if (IS_ERR(port->sm_class_dev))
		goto err_sm_cdev;

	class_set_devdata(port->class_dev,    port);
	class_set_devdata(port->sm_class_dev, port);

	if (class_device_create_file(port->sm_class_dev, &class_device_attr_ibdev))
		goto err_sm_class;
	if (class_device_create_file(port->sm_class_dev, &class_device_attr_port))
		goto err_sm_class;

	spin_lock(&port_lock);
	umad_port[port->dev_num] = port;
	spin_unlock(&port_lock);

	return 0;

err_sm_class:
	class_device_destroy(umad_class, port->sm_dev->dev);

err_sm_cdev:
	cdev_del(port->sm_dev);

err_class:
	class_device_destroy(umad_class, port->dev->dev);

err_cdev:
	cdev_del(port->dev);
	clear_bit(port->dev_num, dev_map);

	return -1;
}

static void ib_umad_kill_port(struct ib_umad_port *port)
{
	struct ib_umad_file *file;
	int id;

	class_set_devdata(port->class_dev,    NULL);
	class_set_devdata(port->sm_class_dev, NULL);

	class_device_destroy(umad_class, port->dev->dev);
	class_device_destroy(umad_class, port->sm_dev->dev);

	cdev_del(port->dev);
	cdev_del(port->sm_dev);

	spin_lock(&port_lock);
	umad_port[port->dev_num] = NULL;
	spin_unlock(&port_lock);

	down_write(&port->mutex);

	port->ib_dev = NULL;

	/*
	 * Now go through the list of files attached to this port and
	 * unregister all of their MAD agents.  We need to hold
	 * port->mutex while doing this to avoid racing with
	 * ib_umad_close(), but we can't hold the mutex for writing
	 * while calling ib_unregister_mad_agent(), since that might
	 * deadlock by calling back into queue_packet().  So we
	 * downgrade our lock to a read lock, and then drop and
	 * reacquire the write lock for the next iteration.
	 *
	 * We do list_del_init() on the file's list_head so that the
	 * list_del in ib_umad_close() is still OK, even after the
	 * file is removed from the list.
	 */
	while (!list_empty(&port->file_list)) {
		file = list_entry(port->file_list.next, struct ib_umad_file,
				  port_list);

		file->agents_dead = 1;
		list_del_init(&file->port_list);

		downgrade_write(&port->mutex);

		for (id = 0; id < IB_UMAD_MAX_AGENTS; ++id)
			if (file->agent[id])
				ib_unregister_mad_agent(file->agent[id]);

		up_read(&port->mutex);
		down_write(&port->mutex);
	}

	up_write(&port->mutex);

	clear_bit(port->dev_num, dev_map);
}

static void ib_umad_add_one(struct ib_device *device)
{
	struct ib_umad_device *umad_dev;
	int s, e, i;

	if (device->node_type == IB_NODE_SWITCH)
		s = e = 0;
	else {
		s = 1;
		e = device->phys_port_cnt;
	}

	umad_dev = kzalloc(sizeof *umad_dev +
			   (e - s + 1) * sizeof (struct ib_umad_port),
			   GFP_KERNEL);
	if (!umad_dev)
		return;

	kref_init(&umad_dev->ref);

	umad_dev->start_port = s;
	umad_dev->end_port   = e;

	for (i = s; i <= e; ++i) {
		umad_dev->port[i - s].umad_dev = umad_dev;

		if (ib_umad_init_port(device, i, &umad_dev->port[i - s]))
			goto err;
	}

	ib_set_client_data(device, &umad_client, umad_dev);

	return;

err:
	while (--i >= s)
		ib_umad_kill_port(&umad_dev->port[i - s]);

	kref_put(&umad_dev->ref, ib_umad_release_dev);
}

static void ib_umad_remove_one(struct ib_device *device)
{
	struct ib_umad_device *umad_dev = ib_get_client_data(device, &umad_client);
	int i;

	if (!umad_dev)
		return;

	for (i = 0; i <= umad_dev->end_port - umad_dev->start_port; ++i)
		ib_umad_kill_port(&umad_dev->port[i]);

	kref_put(&umad_dev->ref, ib_umad_release_dev);
}

static int __init ib_umad_init(void)
{
	int ret;

	ret = register_chrdev_region(base_dev, IB_UMAD_MAX_PORTS * 2,
				     "infiniband_mad");
	if (ret) {
		printk(KERN_ERR "user_mad: couldn't register device number\n");
		goto out;
	}

	umad_class = class_create(THIS_MODULE, "infiniband_mad");
	if (IS_ERR(umad_class)) {
		ret = PTR_ERR(umad_class);
		printk(KERN_ERR "user_mad: couldn't create class infiniband_mad\n");
		goto out_chrdev;
	}

	ret = class_create_file(umad_class, &class_attr_abi_version);
	if (ret) {
		printk(KERN_ERR "user_mad: couldn't create abi_version attribute\n");
		goto out_class;
	}

	ret = ib_register_client(&umad_client);
	if (ret) {
		printk(KERN_ERR "user_mad: couldn't register ib_umad client\n");
		goto out_class;
	}

	return 0;

out_class:
	class_destroy(umad_class);

out_chrdev:
	unregister_chrdev_region(base_dev, IB_UMAD_MAX_PORTS * 2);

out:
	return ret;
}

static void __exit ib_umad_cleanup(void)
{
	ib_unregister_client(&umad_client);
	class_destroy(umad_class);
	unregister_chrdev_region(base_dev, IB_UMAD_MAX_PORTS * 2);
}

module_init(ib_umad_init);
module_exit(ib_umad_cleanup);