--- /dev/null
+/*
+ * NVMe over Fabrics common host code.
+ * Copyright (c) 2015-2016 HGST, a Western Digital Company.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/init.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/parser.h>
+#include <linux/seq_file.h>
+#include "nvme.h"
+#include "fabrics.h"
+
+static LIST_HEAD(nvmf_transports);
+static DEFINE_MUTEX(nvmf_transports_mutex);
+
+static LIST_HEAD(nvmf_hosts);
+static DEFINE_MUTEX(nvmf_hosts_mutex);
+
+static struct nvmf_host *nvmf_default_host;
+
+static struct nvmf_host *__nvmf_host_find(const char *hostnqn)
+{
+       struct nvmf_host *host;
+
+       list_for_each_entry(host, &nvmf_hosts, list) {
+               if (!strcmp(host->nqn, hostnqn))
+                       return host;
+       }
+
+       return NULL;
+}
+
+static struct nvmf_host *nvmf_host_add(const char *hostnqn)
+{
+       struct nvmf_host *host;
+
+       mutex_lock(&nvmf_hosts_mutex);
+       host = __nvmf_host_find(hostnqn);
+       if (host)
+               goto out_unlock;
+
+       host = kmalloc(sizeof(*host), GFP_KERNEL);
+       if (!host)
+               goto out_unlock;
+
+       kref_init(&host->ref);
+       memcpy(host->nqn, hostnqn, NVMF_NQN_SIZE);
+       uuid_le_gen(&host->id);
+
+       list_add_tail(&host->list, &nvmf_hosts);
+out_unlock:
+       mutex_unlock(&nvmf_hosts_mutex);
+       return host;
+}
+
+static struct nvmf_host *nvmf_host_default(void)
+{
+       struct nvmf_host *host;
+
+       host = kmalloc(sizeof(*host), GFP_KERNEL);
+       if (!host)
+               return NULL;
+
+       kref_init(&host->ref);
+       uuid_le_gen(&host->id);
+       snprintf(host->nqn, NVMF_NQN_SIZE,
+               "nqn.2014-08.org.nvmexpress:NVMf:uuid:%pUl", &host->id);
+
+       mutex_lock(&nvmf_hosts_mutex);
+       list_add_tail(&host->list, &nvmf_hosts);
+       mutex_unlock(&nvmf_hosts_mutex);
+
+       return host;
+}
+
+static void nvmf_host_destroy(struct kref *ref)
+{
+       struct nvmf_host *host = container_of(ref, struct nvmf_host, ref);
+
+       kfree(host);
+}
+
+static void nvmf_host_put(struct nvmf_host *host)
+{
+       if (host)
+               kref_put(&host->ref, nvmf_host_destroy);
+}
+
+/**
+ * nvmf_get_address() -  Get address/port
+ * @ctrl:      Host NVMe controller instance which we got the address
+ * @buf:       OUTPUT parameter that will contain the address/port
+ * @size:      buffer size
+ */
+int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size)
+{
+       return snprintf(buf, size, "traddr=%s,trsvcid=%s\n",
+                       ctrl->opts->traddr, ctrl->opts->trsvcid);
+}
+EXPORT_SYMBOL_GPL(nvmf_get_address);
+
+/**
+ * nvmf_get_subsysnqn() - Get subsystem NQN
+ * @ctrl:      Host NVMe controller instance which we got the NQN
+ */
+const char *nvmf_get_subsysnqn(struct nvme_ctrl *ctrl)
+{
+       return ctrl->opts->subsysnqn;
+}
+EXPORT_SYMBOL_GPL(nvmf_get_subsysnqn);
+
+/**
+ * nvmf_reg_read32() -  NVMe Fabrics "Property Get" API function.
+ * @ctrl:      Host NVMe controller instance maintaining the admin
+ *             queue used to submit the property read command to
+ *             the allocated NVMe controller resource on the target system.
+ * @off:       Starting offset value of the targeted property
+ *             register (see the fabrics section of the NVMe standard).
+ * @val:       OUTPUT parameter that will contain the value of
+ *             the property after a successful read.
+ *
+ * Used by the host system to retrieve a 32-bit capsule property value
+ * from an NVMe controller on the target system.
+ *
+ * ("Capsule property" is an "PCIe register concept" applied to the
+ * NVMe fabrics space.)
+ *
+ * Return:
+ *     0: successful read
+ *     > 0: NVMe error status code
+ *     < 0: Linux errno error code
+ */
+int nvmf_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val)
+{
+       struct nvme_command cmd;
+       struct nvme_completion cqe;
+       int ret;
+
+       memset(&cmd, 0, sizeof(cmd));
+       cmd.prop_get.opcode = nvme_fabrics_command;
+       cmd.prop_get.fctype = nvme_fabrics_type_property_get;
+       cmd.prop_get.offset = cpu_to_le32(off);
+
+       ret = __nvme_submit_sync_cmd(ctrl->admin_q, &cmd, &cqe, NULL, 0, 0,
+                       NVME_QID_ANY, 0, 0);
+
+       if (ret >= 0)
+               *val = le64_to_cpu(cqe.result64);
+       if (unlikely(ret != 0))
+               dev_err(ctrl->device,
+                       "Property Get error: %d, offset %#x\n",
+                       ret > 0 ? ret & ~NVME_SC_DNR : ret, off);
+
+       return ret;
+}
+EXPORT_SYMBOL_GPL(nvmf_reg_read32);
+
+/**
+ * nvmf_reg_read64() -  NVMe Fabrics "Property Get" API function.
+ * @ctrl:      Host NVMe controller instance maintaining the admin
+ *             queue used to submit the property read command to
+ *             the allocated controller resource on the target system.
+ * @off:       Starting offset value of the targeted property
+ *             register (see the fabrics section of the NVMe standard).
+ * @val:       OUTPUT parameter that will contain the value of
+ *             the property after a successful read.
+ *
+ * Used by the host system to retrieve a 64-bit capsule property value
+ * from an NVMe controller on the target system.
+ *
+ * ("Capsule property" is an "PCIe register concept" applied to the
+ * NVMe fabrics space.)
+ *
+ * Return:
+ *     0: successful read
+ *     > 0: NVMe error status code
+ *     < 0: Linux errno error code
+ */
+int nvmf_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val)
+{
+       struct nvme_command cmd;
+       struct nvme_completion cqe;
+       int ret;
+
+       memset(&cmd, 0, sizeof(cmd));
+       cmd.prop_get.opcode = nvme_fabrics_command;
+       cmd.prop_get.fctype = nvme_fabrics_type_property_get;
+       cmd.prop_get.attrib = 1;
+       cmd.prop_get.offset = cpu_to_le32(off);
+
+       ret = __nvme_submit_sync_cmd(ctrl->admin_q, &cmd, &cqe, NULL, 0, 0,
+                       NVME_QID_ANY, 0, 0);
+
+       if (ret >= 0)
+               *val = le64_to_cpu(cqe.result64);
+       if (unlikely(ret != 0))
+               dev_err(ctrl->device,
+                       "Property Get error: %d, offset %#x\n",
+                       ret > 0 ? ret & ~NVME_SC_DNR : ret, off);
+       return ret;
+}
+EXPORT_SYMBOL_GPL(nvmf_reg_read64);
+
+/**
+ * nvmf_reg_write32() -  NVMe Fabrics "Property Write" API function.
+ * @ctrl:      Host NVMe controller instance maintaining the admin
+ *             queue used to submit the property read command to
+ *             the allocated NVMe controller resource on the target system.
+ * @off:       Starting offset value of the targeted property
+ *             register (see the fabrics section of the NVMe standard).
+ * @val:       Input parameter that contains the value to be
+ *             written to the property.
+ *
+ * Used by the NVMe host system to write a 32-bit capsule property value
+ * to an NVMe controller on the target system.
+ *
+ * ("Capsule property" is an "PCIe register concept" applied to the
+ * NVMe fabrics space.)
+ *
+ * Return:
+ *     0: successful write
+ *     > 0: NVMe error status code
+ *     < 0: Linux errno error code
+ */
+int nvmf_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val)
+{
+       struct nvme_command cmd;
+       int ret;
+
+       memset(&cmd, 0, sizeof(cmd));
+       cmd.prop_set.opcode = nvme_fabrics_command;
+       cmd.prop_set.fctype = nvme_fabrics_type_property_set;
+       cmd.prop_set.attrib = 0;
+       cmd.prop_set.offset = cpu_to_le32(off);
+       cmd.prop_set.value = cpu_to_le64(val);
+
+       ret = __nvme_submit_sync_cmd(ctrl->admin_q, &cmd, NULL, NULL, 0, 0,
+                       NVME_QID_ANY, 0, 0);
+       if (unlikely(ret))
+               dev_err(ctrl->device,
+                       "Property Set error: %d, offset %#x\n",
+                       ret > 0 ? ret & ~NVME_SC_DNR : ret, off);
+       return ret;
+}
+EXPORT_SYMBOL_GPL(nvmf_reg_write32);
+
+/**
+ * nvmf_log_connect_error() - Error-parsing-diagnostic print
+ * out function for connect() errors.
+ *
+ * @ctrl: the specific /dev/nvmeX device that had the error.
+ *
+ * @errval: Error code to be decoded in a more human-friendly
+ *         printout.
+ *
+ * @offset: For use with the NVMe error code NVME_SC_CONNECT_INVALID_PARAM.
+ *
+ * @cmd: This is the SQE portion of a submission capsule.
+ *
+ * @data: This is the "Data" portion of a submission capsule.
+ */
+static void nvmf_log_connect_error(struct nvme_ctrl *ctrl,
+               int errval, int offset, struct nvme_command *cmd,
+               struct nvmf_connect_data *data)
+{
+       int err_sctype = errval & (~NVME_SC_DNR);
+
+       switch (err_sctype) {
+
+       case (NVME_SC_CONNECT_INVALID_PARAM):
+               if (offset >> 16) {
+                       char *inv_data = "Connect Invalid Data Parameter";
+
+                       switch (offset & 0xffff) {
+                       case (offsetof(struct nvmf_connect_data, cntlid)):
+                               dev_err(ctrl->device,
+                                       "%s, cntlid: %d\n",
+                                       inv_data, data->cntlid);
+                               break;
+                       case (offsetof(struct nvmf_connect_data, hostnqn)):
+                               dev_err(ctrl->device,
+                                       "%s, hostnqn \"%s\"\n",
+                                       inv_data, data->hostnqn);
+                               break;
+                       case (offsetof(struct nvmf_connect_data, subsysnqn)):
+                               dev_err(ctrl->device,
+                                       "%s, subsysnqn \"%s\"\n",
+                                       inv_data, data->subsysnqn);
+                               break;
+                       default:
+                               dev_err(ctrl->device,
+                                       "%s, starting byte offset: %d\n",
+                                      inv_data, offset & 0xffff);
+                               break;
+                       }
+               } else {
+                       char *inv_sqe = "Connect Invalid SQE Parameter";
+
+                       switch (offset) {
+                       case (offsetof(struct nvmf_connect_command, qid)):
+                               dev_err(ctrl->device,
+                                      "%s, qid %d\n",
+                                       inv_sqe, cmd->connect.qid);
+                               break;
+                       default:
+                               dev_err(ctrl->device,
+                                       "%s, starting byte offset: %d\n",
+                                       inv_sqe, offset);
+                       }
+               }
+               break;
+       default:
+               dev_err(ctrl->device,
+                       "Connect command failed, error wo/DNR bit: %d\n",
+                       err_sctype);
+               break;
+       } /* switch (err_sctype) */
+}
+
+/**
+ * nvmf_connect_admin_queue() - NVMe Fabrics Admin Queue "Connect"
+ *                             API function.
+ * @ctrl:      Host nvme controller instance used to request
+ *              a new NVMe controller allocation on the target
+ *              system and  establish an NVMe Admin connection to
+ *              that controller.
+ *
+ * This function enables an NVMe host device to request a new allocation of
+ * an NVMe controller resource on a target system as well establish a
+ * fabrics-protocol connection of the NVMe Admin queue between the
+ * host system device and the allocated NVMe controller on the
+ * target system via a NVMe Fabrics "Connect" command.
+ *
+ * Return:
+ *     0: success
+ *     > 0: NVMe error status code
+ *     < 0: Linux errno error code
+ *
+ */
+int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl)
+{
+       struct nvme_command cmd;
+       struct nvme_completion cqe;
+       struct nvmf_connect_data *data;
+       int ret;
+
+       memset(&cmd, 0, sizeof(cmd));
+       cmd.connect.opcode = nvme_fabrics_command;
+       cmd.connect.fctype = nvme_fabrics_type_connect;
+       cmd.connect.qid = 0;
+       cmd.connect.sqsize = cpu_to_le16(ctrl->sqsize);
+
+       data = kzalloc(sizeof(*data), GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;
+
+       memcpy(&data->hostid, &ctrl->opts->host->id, sizeof(uuid_le));
+       data->cntlid = cpu_to_le16(0xffff);
+       strncpy(data->subsysnqn, ctrl->opts->subsysnqn, NVMF_NQN_SIZE);
+       strncpy(data->hostnqn, ctrl->opts->host->nqn, NVMF_NQN_SIZE);
+
+       ret = __nvme_submit_sync_cmd(ctrl->admin_q, &cmd, &cqe,
+                       data, sizeof(*data), 0, NVME_QID_ANY, 1,
+                       BLK_MQ_REQ_RESERVED | BLK_MQ_REQ_NOWAIT);
+       if (ret) {
+               nvmf_log_connect_error(ctrl, ret, le32_to_cpu(cqe.result),
+                                      &cmd, data);
+               goto out_free_data;
+       }
+
+       ctrl->cntlid = le16_to_cpu(cqe.result16);
+
+out_free_data:
+       kfree(data);
+       return ret;
+}
+EXPORT_SYMBOL_GPL(nvmf_connect_admin_queue);
+
+/**
+ * nvmf_connect_io_queue() - NVMe Fabrics I/O Queue "Connect"
+ *                          API function.
+ * @ctrl:      Host nvme controller instance used to establish an
+ *             NVMe I/O queue connection to the already allocated NVMe
+ *             controller on the target system.
+ * @qid:       NVMe I/O queue number for the new I/O connection between
+ *             host and target (note qid == 0 is illegal as this is
+ *             the Admin queue, per NVMe standard).
+ *
+ * This function issues a fabrics-protocol connection
+ * of a NVMe I/O queue (via NVMe Fabrics "Connect" command)
+ * between the host system device and the allocated NVMe controller
+ * on the target system.
+ *
+ * Return:
+ *     0: success
+ *     > 0: NVMe error status code
+ *     < 0: Linux errno error code
+ */
+int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid)
+{
+       struct nvme_command cmd;
+       struct nvmf_connect_data *data;
+       struct nvme_completion cqe;
+       int ret;
+
+       memset(&cmd, 0, sizeof(cmd));
+       cmd.connect.opcode = nvme_fabrics_command;
+       cmd.connect.fctype = nvme_fabrics_type_connect;
+       cmd.connect.qid = cpu_to_le16(qid);
+       cmd.connect.sqsize = cpu_to_le16(ctrl->sqsize);
+
+       data = kzalloc(sizeof(*data), GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;
+
+       memcpy(&data->hostid, &ctrl->opts->host->id, sizeof(uuid_le));
+       data->cntlid = cpu_to_le16(ctrl->cntlid);
+       strncpy(data->subsysnqn, ctrl->opts->subsysnqn, NVMF_NQN_SIZE);
+       strncpy(data->hostnqn, ctrl->opts->host->nqn, NVMF_NQN_SIZE);
+
+       ret = __nvme_submit_sync_cmd(ctrl->connect_q, &cmd, &cqe,
+                       data, sizeof(*data), 0, qid, 1,
+                       BLK_MQ_REQ_RESERVED | BLK_MQ_REQ_NOWAIT);
+       if (ret) {
+               nvmf_log_connect_error(ctrl, ret, le32_to_cpu(cqe.result),
+                                      &cmd, data);
+       }
+       kfree(data);
+       return ret;
+}
+EXPORT_SYMBOL_GPL(nvmf_connect_io_queue);
+
+/**
+ * nvmf_register_transport() - NVMe Fabrics Library registration function.
+ * @ops:       Transport ops instance to be registered to the
+ *             common fabrics library.
+ *
+ * API function that registers the type of specific transport fabric
+ * being implemented to the common NVMe fabrics library. Part of
+ * the overall init sequence of starting up a fabrics driver.
+ */
+void nvmf_register_transport(struct nvmf_transport_ops *ops)
+{
+       mutex_lock(&nvmf_transports_mutex);
+       list_add_tail(&ops->entry, &nvmf_transports);
+       mutex_unlock(&nvmf_transports_mutex);
+}
+EXPORT_SYMBOL_GPL(nvmf_register_transport);
+
+/**
+ * nvmf_unregister_transport() - NVMe Fabrics Library unregistration function.
+ * @ops:       Transport ops instance to be unregistered from the
+ *             common fabrics library.
+ *
+ * Fabrics API function that unregisters the type of specific transport
+ * fabric being implemented from the common NVMe fabrics library.
+ * Part of the overall exit sequence of unloading the implemented driver.
+ */
+void nvmf_unregister_transport(struct nvmf_transport_ops *ops)
+{
+       mutex_lock(&nvmf_transports_mutex);
+       list_del(&ops->entry);
+       mutex_unlock(&nvmf_transports_mutex);
+}
+EXPORT_SYMBOL_GPL(nvmf_unregister_transport);
+
+static struct nvmf_transport_ops *nvmf_lookup_transport(
+               struct nvmf_ctrl_options *opts)
+{
+       struct nvmf_transport_ops *ops;
+
+       lockdep_assert_held(&nvmf_transports_mutex);
+
+       list_for_each_entry(ops, &nvmf_transports, entry) {
+               if (strcmp(ops->name, opts->transport) == 0)
+                       return ops;
+       }
+
+       return NULL;
+}
+
+static const match_table_t opt_tokens = {
+       { NVMF_OPT_TRANSPORT,           "transport=%s"          },
+       { NVMF_OPT_TRADDR,              "traddr=%s"             },
+       { NVMF_OPT_TRSVCID,             "trsvcid=%s"            },
+       { NVMF_OPT_NQN,                 "nqn=%s"                },
+       { NVMF_OPT_QUEUE_SIZE,          "queue_size=%d"         },
+       { NVMF_OPT_NR_IO_QUEUES,        "nr_io_queues=%d"       },
+       { NVMF_OPT_TL_RETRY_COUNT,      "tl_retry_count=%d"     },
+       { NVMF_OPT_RECONNECT_DELAY,     "reconnect_delay=%d"    },
+       { NVMF_OPT_HOSTNQN,             "hostnqn=%s"            },
+       { NVMF_OPT_ERR,                 NULL                    }
+};
+
+static int nvmf_parse_options(struct nvmf_ctrl_options *opts,
+               const char *buf)
+{
+       substring_t args[MAX_OPT_ARGS];
+       char *options, *o, *p;
+       int token, ret = 0;
+       size_t nqnlen  = 0;
+
+       /* Set defaults */
+       opts->queue_size = NVMF_DEF_QUEUE_SIZE;
+       opts->nr_io_queues = num_online_cpus();
+       opts->tl_retry_count = 2;
+       opts->reconnect_delay = NVMF_DEF_RECONNECT_DELAY;
+
+       options = o = kstrdup(buf, GFP_KERNEL);
+       if (!options)
+               return -ENOMEM;
+
+       while ((p = strsep(&o, ",\n")) != NULL) {
+               if (!*p)
+                       continue;
+
+               token = match_token(p, opt_tokens, args);
+               opts->mask |= token;
+               switch (token) {
+               case NVMF_OPT_TRANSPORT:
+                       p = match_strdup(args);
+                       if (!p) {
+                               ret = -ENOMEM;
+                               goto out;
+                       }
+                       opts->transport = p;
+                       break;
+               case NVMF_OPT_NQN:
+                       p = match_strdup(args);
+                       if (!p) {
+                               ret = -ENOMEM;
+                               goto out;
+                       }
+                       opts->subsysnqn = p;
+                       nqnlen = strlen(opts->subsysnqn);
+                       if (nqnlen >= NVMF_NQN_SIZE) {
+                               pr_err("%s needs to be < %d bytes\n",
+                               opts->subsysnqn, NVMF_NQN_SIZE);
+                               ret = -EINVAL;
+                               goto out;
+                       }
+                       opts->discovery_nqn =
+                               !(strcmp(opts->subsysnqn,
+                                        NVME_DISC_SUBSYS_NAME));
+                       if (opts->discovery_nqn)
+                               opts->nr_io_queues = 0;
+                       break;
+               case NVMF_OPT_TRADDR:
+                       p = match_strdup(args);
+                       if (!p) {
+                               ret = -ENOMEM;
+                               goto out;
+                       }
+                       opts->traddr = p;
+                       break;
+               case NVMF_OPT_TRSVCID:
+                       p = match_strdup(args);
+                       if (!p) {
+                               ret = -ENOMEM;
+                               goto out;
+                       }
+                       opts->trsvcid = p;
+                       break;
+               case NVMF_OPT_QUEUE_SIZE:
+                       if (match_int(args, &token)) {
+                               ret = -EINVAL;
+                               goto out;
+                       }
+                       if (token < NVMF_MIN_QUEUE_SIZE ||
+                           token > NVMF_MAX_QUEUE_SIZE) {
+                               pr_err("Invalid queue_size %d\n", token);
+                               ret = -EINVAL;
+                               goto out;
+                       }
+                       opts->queue_size = token;
+                       break;
+               case NVMF_OPT_NR_IO_QUEUES:
+                       if (match_int(args, &token)) {
+                               ret = -EINVAL;
+                               goto out;
+                       }
+                       if (token <= 0) {
+                               pr_err("Invalid number of IOQs %d\n", token);
+                               ret = -EINVAL;
+                               goto out;
+                       }
+                       opts->nr_io_queues = min_t(unsigned int,
+                                       num_online_cpus(), token);
+                       break;
+               case NVMF_OPT_TL_RETRY_COUNT:
+                       if (match_int(args, &token)) {
+                               ret = -EINVAL;
+                               goto out;
+                       }
+                       if (token < 0) {
+                               pr_err("Invalid tl_retry_count %d\n", token);
+                               ret = -EINVAL;
+                               goto out;
+                       }
+                       opts->tl_retry_count = token;
+                       break;
+               case NVMF_OPT_HOSTNQN:
+                       if (opts->host) {
+                               pr_err("hostnqn already user-assigned: %s\n",
+                                      opts->host->nqn);
+                               ret = -EADDRINUSE;
+                               goto out;
+                       }
+                       p = match_strdup(args);
+                       if (!p) {
+                               ret = -ENOMEM;
+                               goto out;
+                       }
+                       nqnlen = strlen(p);
+                       if (nqnlen >= NVMF_NQN_SIZE) {
+                               pr_err("%s needs to be < %d bytes\n",
+                                       p, NVMF_NQN_SIZE);
+                               ret = -EINVAL;
+                               goto out;
+                       }
+                       opts->host = nvmf_host_add(p);
+                       if (!opts->host) {
+                               ret = -ENOMEM;
+                               goto out;
+                       }
+                       break;
+               case NVMF_OPT_RECONNECT_DELAY:
+                       if (match_int(args, &token)) {
+                               ret = -EINVAL;
+                               goto out;
+                       }
+                       if (token <= 0) {
+                               pr_err("Invalid reconnect_delay %d\n", token);
+                               ret = -EINVAL;
+                               goto out;
+                       }
+                       opts->reconnect_delay = token;
+                       break;
+               default:
+                       pr_warn("unknown parameter or missing value '%s' in ctrl creation request\n",
+                               p);
+                       ret = -EINVAL;
+                       goto out;
+               }
+       }
+
+       if (!opts->host) {
+               kref_get(&nvmf_default_host->ref);
+               opts->host = nvmf_default_host;
+       }
+
+out:
+       kfree(options);
+       return ret;
+}
+
+static int nvmf_check_required_opts(struct nvmf_ctrl_options *opts,
+               unsigned int required_opts)
+{
+       if ((opts->mask & required_opts) != required_opts) {
+               int i;
+
+               for (i = 0; i < ARRAY_SIZE(opt_tokens); i++) {
+                       if ((opt_tokens[i].token & required_opts) &&
+                           !(opt_tokens[i].token & opts->mask)) {
+                               pr_warn("missing parameter '%s'\n",
+                                       opt_tokens[i].pattern);
+                       }
+               }
+
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static int nvmf_check_allowed_opts(struct nvmf_ctrl_options *opts,
+               unsigned int allowed_opts)
+{
+       if (opts->mask & ~allowed_opts) {
+               int i;
+
+               for (i = 0; i < ARRAY_SIZE(opt_tokens); i++) {
+                       if (opt_tokens[i].token & ~allowed_opts) {
+                               pr_warn("invalid parameter '%s'\n",
+                                       opt_tokens[i].pattern);
+                       }
+               }
+
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+void nvmf_free_options(struct nvmf_ctrl_options *opts)
+{
+       nvmf_host_put(opts->host);
+       kfree(opts->transport);
+       kfree(opts->traddr);
+       kfree(opts->trsvcid);
+       kfree(opts->subsysnqn);
+       kfree(opts);
+}
+EXPORT_SYMBOL_GPL(nvmf_free_options);
+
+#define NVMF_REQUIRED_OPTS     (NVMF_OPT_TRANSPORT | NVMF_OPT_NQN)
+#define NVMF_ALLOWED_OPTS      (NVMF_OPT_QUEUE_SIZE | NVMF_OPT_NR_IO_QUEUES | \
+                                NVMF_OPT_HOSTNQN)
+
+static struct nvme_ctrl *
+nvmf_create_ctrl(struct device *dev, const char *buf, size_t count)
+{
+       struct nvmf_ctrl_options *opts;
+       struct nvmf_transport_ops *ops;
+       struct nvme_ctrl *ctrl;
+       int ret;
+
+       opts = kzalloc(sizeof(*opts), GFP_KERNEL);
+       if (!opts)
+               return ERR_PTR(-ENOMEM);
+
+       ret = nvmf_parse_options(opts, buf);
+       if (ret)
+               goto out_free_opts;
+
+       /*
+        * Check the generic options first as we need a valid transport for
+        * the lookup below.  Then clear the generic flags so that transport
+        * drivers don't have to care about them.
+        */
+       ret = nvmf_check_required_opts(opts, NVMF_REQUIRED_OPTS);
+       if (ret)
+               goto out_free_opts;
+       opts->mask &= ~NVMF_REQUIRED_OPTS;
+
+       mutex_lock(&nvmf_transports_mutex);
+       ops = nvmf_lookup_transport(opts);
+       if (!ops) {
+               pr_info("no handler found for transport %s.\n",
+                       opts->transport);
+               ret = -EINVAL;
+               goto out_unlock;
+       }
+
+       ret = nvmf_check_required_opts(opts, ops->required_opts);
+       if (ret)
+               goto out_unlock;
+       ret = nvmf_check_allowed_opts(opts, NVMF_ALLOWED_OPTS |
+                               ops->allowed_opts | ops->required_opts);
+       if (ret)
+               goto out_unlock;
+
+       ctrl = ops->create_ctrl(dev, opts);
+       if (IS_ERR(ctrl)) {
+               ret = PTR_ERR(ctrl);
+               goto out_unlock;
+       }
+
+       mutex_unlock(&nvmf_transports_mutex);
+       return ctrl;
+
+out_unlock:
+       mutex_unlock(&nvmf_transports_mutex);
+out_free_opts:
+       nvmf_host_put(opts->host);
+       kfree(opts);
+       return ERR_PTR(ret);
+}
+
+static struct class *nvmf_class;
+static struct device *nvmf_device;
+static DEFINE_MUTEX(nvmf_dev_mutex);
+
+static ssize_t nvmf_dev_write(struct file *file, const char __user *ubuf,
+               size_t count, loff_t *pos)
+{
+       struct seq_file *seq_file = file->private_data;
+       struct nvme_ctrl *ctrl;
+       const char *buf;
+       int ret = 0;
+
+       if (count > PAGE_SIZE)
+               return -ENOMEM;
+
+       buf = memdup_user_nul(ubuf, count);
+       if (IS_ERR(buf))
+               return PTR_ERR(buf);
+
+       mutex_lock(&nvmf_dev_mutex);
+       if (seq_file->private) {
+               ret = -EINVAL;
+               goto out_unlock;
+       }
+
+       ctrl = nvmf_create_ctrl(nvmf_device, buf, count);
+       if (IS_ERR(ctrl)) {
+               ret = PTR_ERR(ctrl);
+               goto out_unlock;
+       }
+
+       seq_file->private = ctrl;
+
+out_unlock:
+       mutex_unlock(&nvmf_dev_mutex);
+       kfree(buf);
+       return ret ? ret : count;
+}
+
+static int nvmf_dev_show(struct seq_file *seq_file, void *private)
+{
+       struct nvme_ctrl *ctrl;
+       int ret = 0;
+
+       mutex_lock(&nvmf_dev_mutex);
+       ctrl = seq_file->private;
+       if (!ctrl) {
+               ret = -EINVAL;
+               goto out_unlock;
+       }
+
+       seq_printf(seq_file, "instance=%d,cntlid=%d\n",
+                       ctrl->instance, ctrl->cntlid);
+
+out_unlock:
+       mutex_unlock(&nvmf_dev_mutex);
+       return ret;
+}
+
+static int nvmf_dev_open(struct inode *inode, struct file *file)
+{
+       /*
+        * The miscdevice code initializes file->private_data, but doesn't
+        * make use of it later.
+        */
+       file->private_data = NULL;
+       return single_open(file, nvmf_dev_show, NULL);
+}
+
+static int nvmf_dev_release(struct inode *inode, struct file *file)
+{
+       struct seq_file *seq_file = file->private_data;
+       struct nvme_ctrl *ctrl = seq_file->private;
+
+       if (ctrl)
+               nvme_put_ctrl(ctrl);
+       return single_release(inode, file);
+}
+
+static const struct file_operations nvmf_dev_fops = {
+       .owner          = THIS_MODULE,
+       .write          = nvmf_dev_write,
+       .read           = seq_read,
+       .open           = nvmf_dev_open,
+       .release        = nvmf_dev_release,
+};
+
+static struct miscdevice nvmf_misc = {
+       .minor          = MISC_DYNAMIC_MINOR,
+       .name           = "nvme-fabrics",
+       .fops           = &nvmf_dev_fops,
+};
+
+static int __init nvmf_init(void)
+{
+       int ret;
+
+       nvmf_default_host = nvmf_host_default();
+       if (!nvmf_default_host)
+               return -ENOMEM;
+
+       nvmf_class = class_create(THIS_MODULE, "nvme-fabrics");
+       if (IS_ERR(nvmf_class)) {
+               pr_err("couldn't register class nvme-fabrics\n");
+               ret = PTR_ERR(nvmf_class);
+               goto out_free_host;
+       }
+
+       nvmf_device =
+               device_create(nvmf_class, NULL, MKDEV(0, 0), NULL, "ctl");
+       if (IS_ERR(nvmf_device)) {
+               pr_err("couldn't create nvme-fabris device!\n");
+               ret = PTR_ERR(nvmf_device);
+               goto out_destroy_class;
+       }
+
+       ret = misc_register(&nvmf_misc);
+       if (ret) {
+               pr_err("couldn't register misc device: %d\n", ret);
+               goto out_destroy_device;
+       }
+
+       return 0;
+
+out_destroy_device:
+       device_destroy(nvmf_class, MKDEV(0, 0));
+out_destroy_class:
+       class_destroy(nvmf_class);
+out_free_host:
+       nvmf_host_put(nvmf_default_host);
+       return ret;
+}
+
+static void __exit nvmf_exit(void)
+{
+       misc_deregister(&nvmf_misc);
+       device_destroy(nvmf_class, MKDEV(0, 0));
+       class_destroy(nvmf_class);
+       nvmf_host_put(nvmf_default_host);
+
+       BUILD_BUG_ON(sizeof(struct nvmf_connect_command) != 64);
+       BUILD_BUG_ON(sizeof(struct nvmf_property_get_command) != 64);
+       BUILD_BUG_ON(sizeof(struct nvmf_property_set_command) != 64);
+       BUILD_BUG_ON(sizeof(struct nvmf_connect_data) != 1024);
+}
+
+MODULE_LICENSE("GPL v2");
+
+module_init(nvmf_init);
+module_exit(nvmf_exit);