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Diffstat (limited to 'drivers/nvme/host/fabrics.h')
| -rw-r--r-- | drivers/nvme/host/fabrics.h | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/drivers/nvme/host/fabrics.h b/drivers/nvme/host/fabrics.h new file mode 100644 index 000000000..aa2fdb2a2 --- /dev/null +++ b/drivers/nvme/host/fabrics.h @@ -0,0 +1,179 @@ +/* + * 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. + */ +#ifndef _NVME_FABRICS_H +#define _NVME_FABRICS_H 1 + +#include <linux/in.h> +#include <linux/inet.h> + +#define NVMF_MIN_QUEUE_SIZE 16 +#define NVMF_MAX_QUEUE_SIZE 1024 +#define NVMF_DEF_QUEUE_SIZE 128 +#define NVMF_DEF_RECONNECT_DELAY 10 +/* default to 600 seconds of reconnect attempts before giving up */ +#define NVMF_DEF_CTRL_LOSS_TMO 600 + +/* + * Define a host as seen by the target. We allocate one at boot, but also + * allow the override it when creating controllers. This is both to provide + * persistence of the Host NQN over multiple boots, and to allow using + * multiple ones, for example in a container scenario. Because we must not + * use different Host NQNs with the same Host ID we generate a Host ID and + * use this structure to keep track of the relation between the two. + */ +struct nvmf_host { + struct kref ref; + struct list_head list; + char nqn[NVMF_NQN_SIZE]; + uuid_t id; +}; + +/** + * enum nvmf_parsing_opts - used to define the sysfs parsing options used. + */ +enum { + NVMF_OPT_ERR = 0, + NVMF_OPT_TRANSPORT = 1 << 0, + NVMF_OPT_NQN = 1 << 1, + NVMF_OPT_TRADDR = 1 << 2, + NVMF_OPT_TRSVCID = 1 << 3, + NVMF_OPT_QUEUE_SIZE = 1 << 4, + NVMF_OPT_NR_IO_QUEUES = 1 << 5, + NVMF_OPT_TL_RETRY_COUNT = 1 << 6, + NVMF_OPT_KATO = 1 << 7, + NVMF_OPT_HOSTNQN = 1 << 8, + NVMF_OPT_RECONNECT_DELAY = 1 << 9, + NVMF_OPT_HOST_TRADDR = 1 << 10, + NVMF_OPT_CTRL_LOSS_TMO = 1 << 11, + NVMF_OPT_HOST_ID = 1 << 12, + NVMF_OPT_DUP_CONNECT = 1 << 13, +}; + +/** + * struct nvmf_ctrl_options - Used to hold the options specified + * with the parsing opts enum. + * @mask: Used by the fabrics library to parse through sysfs options + * on adding a NVMe controller. + * @transport: Holds the fabric transport "technology name" (for a lack of + * better description) that will be used by an NVMe controller + * being added. + * @subsysnqn: Hold the fully qualified NQN subystem name (format defined + * in the NVMe specification, "NVMe Qualified Names"). + * @traddr: The transport-specific TRADDR field for a port on the + * subsystem which is adding a controller. + * @trsvcid: The transport-specific TRSVCID field for a port on the + * subsystem which is adding a controller. + * @host_traddr: A transport-specific field identifying the NVME host port + * to use for the connection to the controller. + * @queue_size: Number of IO queue elements. + * @nr_io_queues: Number of controller IO queues that will be established. + * @reconnect_delay: Time between two consecutive reconnect attempts. + * @discovery_nqn: indicates if the subsysnqn is the well-known discovery NQN. + * @kato: Keep-alive timeout. + * @host: Virtual NVMe host, contains the NQN and Host ID. + * @max_reconnects: maximum number of allowed reconnect attempts before removing + * the controller, (-1) means reconnect forever, zero means remove + * immediately; + */ +struct nvmf_ctrl_options { + unsigned mask; + char *transport; + char *subsysnqn; + char *traddr; + char *trsvcid; + char *host_traddr; + size_t queue_size; + unsigned int nr_io_queues; + unsigned int reconnect_delay; + bool discovery_nqn; + bool duplicate_connect; + unsigned int kato; + struct nvmf_host *host; + int max_reconnects; +}; + +/* + * struct nvmf_transport_ops - used to register a specific + * fabric implementation of NVMe fabrics. + * @entry: Used by the fabrics library to add the new + * registration entry to its linked-list internal tree. + * @module: Transport module reference + * @name: Name of the NVMe fabric driver implementation. + * @required_opts: sysfs command-line options that must be specified + * when adding a new NVMe controller. + * @allowed_opts: sysfs command-line options that can be specified + * when adding a new NVMe controller. + * @create_ctrl(): function pointer that points to a non-NVMe + * implementation-specific fabric technology + * that would go into starting up that fabric + * for the purpose of conneciton to an NVMe controller + * using that fabric technology. + * + * Notes: + * 1. At minimum, 'required_opts' and 'allowed_opts' should + * be set to the same enum parsing options defined earlier. + * 2. create_ctrl() must be defined (even if it does nothing) + * 3. struct nvmf_transport_ops must be statically allocated in the + * modules .bss section so that a pure module_get on @module + * prevents the memory from beeing freed. + */ +struct nvmf_transport_ops { + struct list_head entry; + struct module *module; + const char *name; + int required_opts; + int allowed_opts; + struct nvme_ctrl *(*create_ctrl)(struct device *dev, + struct nvmf_ctrl_options *opts); +}; + +static inline bool +nvmf_ctlr_matches_baseopts(struct nvme_ctrl *ctrl, + struct nvmf_ctrl_options *opts) +{ + if (ctrl->state == NVME_CTRL_DELETING || + ctrl->state == NVME_CTRL_DEAD || + strcmp(opts->subsysnqn, ctrl->opts->subsysnqn) || + strcmp(opts->host->nqn, ctrl->opts->host->nqn) || + memcmp(&opts->host->id, &ctrl->opts->host->id, sizeof(uuid_t))) + return false; + + return true; +} + +int nvmf_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val); +int nvmf_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val); +int nvmf_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val); +int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl); +int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid); +int nvmf_register_transport(struct nvmf_transport_ops *ops); +void nvmf_unregister_transport(struct nvmf_transport_ops *ops); +void nvmf_free_options(struct nvmf_ctrl_options *opts); +int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size); +bool nvmf_should_reconnect(struct nvme_ctrl *ctrl); +blk_status_t nvmf_fail_nonready_command(struct nvme_ctrl *ctrl, + struct request *rq); +bool __nvmf_check_ready(struct nvme_ctrl *ctrl, struct request *rq, + bool queue_live); + +static inline bool nvmf_check_ready(struct nvme_ctrl *ctrl, struct request *rq, + bool queue_live) +{ + if (likely(ctrl->state == NVME_CTRL_LIVE || + ctrl->state == NVME_CTRL_ADMIN_ONLY)) + return true; + return __nvmf_check_ready(ctrl, rq, queue_live); +} + +#endif /* _NVME_FABRICS_H */ |