nvme-fabrics: add a generic NVMe over Fabrics library

	  to say N here, unless you run a distro that abuses the SCSI

	  emulation to provide stable device names for mount by id, like

	  some OpenSuSE and SLES versions.

config NVME_FABRICS

	tristate

obj-$(CONFIG_NVME_CORE)			+= nvme-core.o

obj-$(CONFIG_BLK_DEV_NVME)		+= nvme.o

obj-$(CONFIG_NVME_FABRICS)		+= nvme-fabrics.o

nvme-core-y				:= core.o

nvme-core-$(CONFIG_BLK_DEV_NVME_SCSI)	+= scsi.o

nvme-core-$(CONFIG_NVM)			+= lightnvm.o

nvme-y					+= pci.o

nvme-fabrics-y				+= fabrics.o

	}

	nvme_set_queue_limits(ctrl, ctrl->admin_q);

	ctrl->sgls = le32_to_cpu(id->sgls);

	if (ctrl->ops->is_fabrics) {

		ctrl->icdoff = le16_to_cpu(id->icdoff);

		ctrl->ioccsz = le32_to_cpu(id->ioccsz);

		ctrl->iorcsz = le32_to_cpu(id->iorcsz);

		ctrl->maxcmd = le16_to_cpu(id->maxcmd);

		/*

		 * In fabrics we need to verify the cntlid matches the

		 * admin connect

		 */

		if (ctrl->cntlid != le16_to_cpu(id->cntlid))

			ret = -EINVAL;

	} else {

		ctrl->cntlid = le16_to_cpu(id->cntlid);

	}

	kfree(id);

	return 0;

	return ret;

}

EXPORT_SYMBOL_GPL(nvme_init_identify);

/*

 * 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

/*

 * 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_le			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_HOSTNQN	= 1 << 8,

	NVMF_OPT_RECONNECT_DELAY = 1 << 9,

};

/**

 * 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:	network address that will be used by the host to communicate

 *		to the added NVMe controller.

 * @trsvcid:	network port used for host-controller communication.

 * @queue_size: Number of IO queue elements.

 * @nr_io_queues: Number of controller IO queues that will be established.

 * @tl_retry_count: Number of transport layer retries for a fabric queue before

 *		     kicking upper layer(s) error recovery.

 * @reconnect_delay: Time between two consecutive reconnect attempts.

 * @discovery_nqn: indicates if the subsysnqn is the well-known discovery NQN.

 * @host:	Virtual NVMe host, contains the NQN and Host ID.

 */

struct nvmf_ctrl_options {

	unsigned		mask;

	char			*transport;

	char			*subsysnqn;

	char			*traddr;

	char			*trsvcid;

	size_t			queue_size;

	unsigned int		nr_io_queues;

	unsigned short		tl_retry_count;

	unsigned int		reconnect_delay;

	bool			discovery_nqn;

	struct nvmf_host	*host;

};

/*

 * 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.

 * @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)

 */

struct nvmf_transport_ops {

	struct list_head	entry;

	const char		*name;

	int			required_opts;

	int			allowed_opts;

	struct nvme_ctrl	*(*create_ctrl)(struct device *dev,

					struct nvmf_ctrl_options *opts);

};

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);

void 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);

const char *nvmf_get_subsysnqn(struct nvme_ctrl *ctrl);

int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size);

#endif /* _NVME_FABRICS_H */