Commit 0e2d00eb authored by Jason Gunthorpe's avatar Jason Gunthorpe Committed by Doug Ledford
Browse files

RDMA: Add NLDEV_GET_CHARDEV to allow char dev discovery and autoload 



Allow userspace to issue a netlink query against the ib_device for
something like "uverbs" and get back the char dev name, inode major/minor,
and interface ABI information for "uverbs0".

Since we are now in netlink this can also trigger a module autoload to
make the uverbs device come into existence.

Largely this will let us replace searching and reading inside sysfs to
setup devices, and provides an alternative (using driver_id) to device
name based provider binding for things like rxe.

Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: default avatarDoug Ledford <dledford@redhat.com>
parent 5d60c111

drivers/infiniband/core/core_priv.h

+9 −0
Original line number Diff line number Diff line
@@ -88,6 +88,15 @@ typedef int (*nldev_callback)(struct ib_device *device, 
int ib_enum_all_devs(nldev_callback nldev_cb, struct sk_buff *skb,

		     struct netlink_callback *cb);



struct ib_client_nl_info {

	struct sk_buff *nl_msg;

	struct device *cdev;

	unsigned int port;

	u64 abi;

};

int ib_get_client_nl_info(struct ib_device *ibdev, const char *client_name,

			  struct ib_client_nl_info *res);



enum ib_cache_gid_default_mode {

	IB_CACHE_GID_DEFAULT_MODE_SET,

	IB_CACHE_GID_DEFAULT_MODE_DELETE

drivers/infiniband/core/device.c

+98 −0
Original line number Diff line number Diff line
@@ -1726,6 +1726,104 @@ void ib_unregister_client(struct ib_client *client) 
}

EXPORT_SYMBOL(ib_unregister_client);



static int __ib_get_global_client_nl_info(const char *client_name,

					  struct ib_client_nl_info *res)

{

	struct ib_client *client;

	unsigned long index;

	int ret = -ENOENT;



	down_read(&clients_rwsem);

	xa_for_each_marked (&clients, index, client, CLIENT_REGISTERED) {

		if (strcmp(client->name, client_name) != 0)

			continue;

		if (!client->get_global_nl_info) {

			ret = -EOPNOTSUPP;

			break;

		}

		ret = client->get_global_nl_info(res);

		if (WARN_ON(ret == -ENOENT))

			ret = -EINVAL;

		if (!ret && res->cdev)

			get_device(res->cdev);

		break;

	}

	up_read(&clients_rwsem);

	return ret;

}



static int __ib_get_client_nl_info(struct ib_device *ibdev,

				   const char *client_name,

				   struct ib_client_nl_info *res)

{

	unsigned long index;

	void *client_data;

	int ret = -ENOENT;



	down_read(&ibdev->client_data_rwsem);

	xan_for_each_marked (&ibdev->client_data, index, client_data,

			     CLIENT_DATA_REGISTERED) {

		struct ib_client *client = xa_load(&clients, index);



		if (!client || strcmp(client->name, client_name) != 0)

			continue;

		if (!client->get_nl_info) {

			ret = -EOPNOTSUPP;

			break;

		}

		ret = client->get_nl_info(ibdev, client_data, res);

		if (WARN_ON(ret == -ENOENT))

			ret = -EINVAL;



		/*

		 * The cdev is guaranteed valid as long as we are inside the

		 * client_data_rwsem as remove_one can't be called. Keep it

		 * valid for the caller.

		 */

		if (!ret && res->cdev)

			get_device(res->cdev);

		break;

	}

	up_read(&ibdev->client_data_rwsem);



	return ret;

}



/**

 * ib_get_client_nl_info - Fetch the nl_info from a client

 * @device - IB device

 * @client_name - Name of the client

 * @res - Result of the query

 */

int ib_get_client_nl_info(struct ib_device *ibdev, const char *client_name,

			  struct ib_client_nl_info *res)

{

	int ret;



	if (ibdev)

		ret = __ib_get_client_nl_info(ibdev, client_name, res);

	else

		ret = __ib_get_global_client_nl_info(client_name, res);

#ifdef CONFIG_MODULES

	if (ret == -ENOENT) {

		request_module("rdma-client-%s", client_name);

		if (ibdev)

			ret = __ib_get_client_nl_info(ibdev, client_name, res);

		else

			ret = __ib_get_global_client_nl_info(client_name, res);

	}

#endif

	if (ret) {

		if (ret == -ENOENT)

			return -EOPNOTSUPP;

		return ret;

	}



	if (WARN_ON(!res->cdev))

		return -EINVAL;

	return 0;

}



/**

 * ib_set_client_data - Set IB client context

 * @device:Device to set context for

drivers/infiniband/core/nldev.c

+94 −0
Original line number Diff line number Diff line
@@ -120,6 +120,12 @@ static const struct nla_policy nldev_policy[RDMA_NLDEV_ATTR_MAX] = { 
	[RDMA_NLDEV_ATTR_DEV_PROTOCOL]		= { .type = NLA_NUL_STRING,

				    .len = RDMA_NLDEV_ATTR_ENTRY_STRLEN },

	[RDMA_NLDEV_NET_NS_FD]			= { .type = NLA_U32 },

	[RDMA_NLDEV_ATTR_CHARDEV]		= { .type = NLA_U64 },

	[RDMA_NLDEV_ATTR_CHARDEV_ABI]		= { .type = NLA_U64 },

	[RDMA_NLDEV_ATTR_CHARDEV_TYPE]		= { .type = NLA_NUL_STRING,

				    .len = 128 },

	[RDMA_NLDEV_ATTR_CHARDEV_NAME]		= { .type = NLA_NUL_STRING,

				    .len = RDMA_NLDEV_ATTR_ENTRY_STRLEN },

};



static int put_driver_name_print_type(struct sk_buff *msg, const char *name,
@@ -1347,6 +1353,91 @@ static int nldev_dellink(struct sk_buff *skb, struct nlmsghdr *nlh, 
	return 0;

}



static int nldev_get_chardev(struct sk_buff *skb, struct nlmsghdr *nlh,

			     struct netlink_ext_ack *extack)

{

	struct nlattr *tb[RDMA_NLDEV_ATTR_MAX];

	char client_name[IB_DEVICE_NAME_MAX];

	struct ib_client_nl_info data = {};

	struct ib_device *ibdev = NULL;

	struct sk_buff *msg;

	u32 index;

	int err;



	err = nlmsg_parse(nlh, 0, tb, RDMA_NLDEV_ATTR_MAX - 1, nldev_policy,

			  extack);

	if (err || !tb[RDMA_NLDEV_ATTR_CHARDEV_TYPE])

		return -EINVAL;



	if (nla_strlcpy(client_name, tb[RDMA_NLDEV_ATTR_CHARDEV_TYPE],

			sizeof(client_name)) >= sizeof(client_name))

		return -EINVAL;



	if (tb[RDMA_NLDEV_ATTR_DEV_INDEX]) {

		index = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);

		ibdev = ib_device_get_by_index(sock_net(skb->sk), index);

		if (!ibdev)

			return -EINVAL;



		if (tb[RDMA_NLDEV_ATTR_PORT_INDEX]) {

			data.port = nla_get_u32(tb[RDMA_NLDEV_ATTR_PORT_INDEX]);

			if (!rdma_is_port_valid(ibdev, data.port)) {

				err = -EINVAL;

				goto out_put;

			}

		} else {

			data.port = -1;

		}

	} else if (tb[RDMA_NLDEV_ATTR_PORT_INDEX]) {

		return -EINVAL;

	}



	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);

	if (!msg) {

		err = -ENOMEM;

		goto out_put;

	}

	nlh = nlmsg_put(msg, NETLINK_CB(skb).portid, nlh->nlmsg_seq,

			RDMA_NL_GET_TYPE(RDMA_NL_NLDEV,

					 RDMA_NLDEV_CMD_GET_CHARDEV),

			0, 0);



	data.nl_msg = msg;

	err = ib_get_client_nl_info(ibdev, client_name, &data);

	if (err)

		goto out_nlmsg;



	err = nla_put_u64_64bit(msg, RDMA_NLDEV_ATTR_CHARDEV,

				huge_encode_dev(data.cdev->devt),

				RDMA_NLDEV_ATTR_PAD);

	if (err)

		goto out_data;

	err = nla_put_u64_64bit(msg, RDMA_NLDEV_ATTR_CHARDEV_ABI, data.abi,

				RDMA_NLDEV_ATTR_PAD);

	if (err)

		goto out_data;

	if (nla_put_string(msg, RDMA_NLDEV_ATTR_CHARDEV_NAME,

			   dev_name(data.cdev))) {

		err = -EMSGSIZE;

		goto out_data;

	}



	nlmsg_end(msg, nlh);

	put_device(data.cdev);

	if (ibdev)

		ib_device_put(ibdev);

	return rdma_nl_unicast(msg, NETLINK_CB(skb).portid);



out_data:

	put_device(data.cdev);

out_nlmsg:

	nlmsg_free(msg);

out_put:

	if (ibdev)

		ib_device_put(ibdev);

	return err;

}



static int nldev_sys_get_doit(struct sk_buff *skb, struct nlmsghdr *nlh,

			      struct netlink_ext_ack *extack)

{
@@ -1404,6 +1495,9 @@ static const struct rdma_nl_cbs nldev_cb_table[RDMA_NLDEV_NUM_OPS] = { 
		.doit = nldev_get_doit,

		.dump = nldev_get_dumpit,

	},

	[RDMA_NLDEV_CMD_GET_CHARDEV] = {

		.doit = nldev_get_chardev,

	},

	[RDMA_NLDEV_CMD_SET] = {

		.doit = nldev_set_doit,

		.flags = RDMA_NL_ADMIN_PERM,

include/rdma/ib_verbs.h

+4 −0
Original line number Diff line number Diff line
@@ -2684,10 +2684,14 @@ struct ib_device { 
	u32 iw_driver_flags;

};



struct ib_client_nl_info;

struct ib_client {

	const char *name;

	void (*add)   (struct ib_device *);

	void (*remove)(struct ib_device *, void *client_data);

	int (*get_nl_info)(struct ib_device *ibdev, void *client_data,

			   struct ib_client_nl_info *res);

	int (*get_global_nl_info)(struct ib_client_nl_info *res);



	/* Returns the net_dev belonging to this ib_client and matching the

	 * given parameters.

include/rdma/rdma_netlink.h

+2 −0
Original line number Diff line number Diff line
@@ -110,4 +110,6 @@ void rdma_link_register(struct rdma_link_ops *ops); 
void rdma_link_unregister(struct rdma_link_ops *ops);



#define MODULE_ALIAS_RDMA_LINK(type) MODULE_ALIAS("rdma-link-" type)

#define MODULE_ALIAS_RDMA_CLIENT(type) MODULE_ALIAS("rdma-client-" type)



#endif /* _RDMA_NETLINK_H */

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