From 0e2d00eb6fd45f2a645f4874286bdc5b4b53782b Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Thu, 13 Jun 2019 21:38:18 -0300 Subject: [PATCH] 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: Jason Gunthorpe Signed-off-by: Doug Ledford --- drivers/infiniband/core/core_priv.h | 9 +++ drivers/infiniband/core/device.c | 98 +++++++++++++++++++++++++++++ drivers/infiniband/core/nldev.c | 94 +++++++++++++++++++++++++++ include/rdma/ib_verbs.h | 4 ++ include/rdma/rdma_netlink.h | 2 + include/uapi/rdma/rdma_netlink.h | 14 +++++ 6 files changed, 221 insertions(+) diff --git a/drivers/infiniband/core/core_priv.h b/drivers/infiniband/core/core_priv.h index ff40a450b5d2..a953c2fa2e78 100644 --- a/drivers/infiniband/core/core_priv.h +++ b/drivers/infiniband/core/core_priv.h @@ -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 diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c index abb169f31d0f..7db8566cdb89 100644 --- a/drivers/infiniband/core/device.c +++ b/drivers/infiniband/core/device.c @@ -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 diff --git a/drivers/infiniband/core/nldev.c b/drivers/infiniband/core/nldev.c index 69188cbbd99b..16b5d6d4dd1c 100644 --- a/drivers/infiniband/core/nldev.c +++ b/drivers/infiniband/core/nldev.c @@ -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, diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h index 973514ea17a7..a1265e9ce2d1 100644 --- a/include/rdma/ib_verbs.h +++ b/include/rdma/ib_verbs.h @@ -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. diff --git a/include/rdma/rdma_netlink.h b/include/rdma/rdma_netlink.h index 10732ab31ba2..c7acbe083428 100644 --- a/include/rdma/rdma_netlink.h +++ b/include/rdma/rdma_netlink.h @@ -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 */ diff --git a/include/uapi/rdma/rdma_netlink.h b/include/uapi/rdma/rdma_netlink.h index f588e8551c6c..9903db21a42c 100644 --- a/include/uapi/rdma/rdma_netlink.h +++ b/include/uapi/rdma/rdma_netlink.h @@ -279,6 +279,8 @@ enum rdma_nldev_command { RDMA_NLDEV_CMD_RES_PD_GET, /* can dump */ + RDMA_NLDEV_CMD_GET_CHARDEV, + RDMA_NLDEV_NUM_OPS }; @@ -491,6 +493,18 @@ enum rdma_nldev_attr { */ RDMA_NLDEV_NET_NS_FD, /* u32 */ + /* + * Information about a chardev. + * CHARDEV_TYPE is the name of the chardev ABI (ie uverbs, umad, etc) + * CHARDEV_ABI signals the ABI revision (historical) + * CHARDEV_NAME is the kernel name for the /dev/ file (no directory) + * CHARDEV is the 64 bit dev_t for the inode + */ + RDMA_NLDEV_ATTR_CHARDEV_TYPE, /* string */ + RDMA_NLDEV_ATTR_CHARDEV_NAME, /* string */ + RDMA_NLDEV_ATTR_CHARDEV_ABI, /* u64 */ + RDMA_NLDEV_ATTR_CHARDEV, /* u64 */ + /* * Always the end */ -- 2.25.1