drivers/nvme/host/nvme.h - kernel/msm-4.19 - Gitiles

 /*
  * Copyright (c) 2011-2014, Intel Corporation.
  *
  * 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_H
 #define _NVME_H

 #include <linux/nvme.h>
 #include <linux/cdev.h>
 #include <linux/pci.h>
 #include <linux/kref.h>
 #include <linux/blk-mq.h>
 #include <linux/lightnvm.h>
 #include <linux/sed-opal.h>

 extern unsigned int nvme_io_timeout;
 #define NVME_IO_TIMEOUT	(nvme_io_timeout * HZ)

 extern unsigned int admin_timeout;
 #define ADMIN_TIMEOUT	(admin_timeout * HZ)

 #define NVME_DEFAULT_KATO	5
 #define NVME_KATO_GRACE		10

 extern struct workqueue_struct *nvme_wq;
 extern struct workqueue_struct *nvme_reset_wq;
 extern struct workqueue_struct *nvme_delete_wq;

 enum {
 	NVME_NS_LBA		= 0,
 	NVME_NS_LIGHTNVM	= 1,
 };

 /*
  * List of workarounds for devices that required behavior not specified in
  * the standard.
  */
 enum nvme_quirks {
 	/*
 	 * Prefers I/O aligned to a stripe size specified in a vendor
 	 * specific Identify field.
 	 */
 	NVME_QUIRK_STRIPE_SIZE			= (1 << 0),

 	/*
 	 * The controller doesn't handle Identify value others than 0 or 1
 	 * correctly.
 	 */
 	NVME_QUIRK_IDENTIFY_CNS			= (1 << 1),

 	/*
 	 * The controller deterministically returns O's on reads to
 	 * logical blocks that deallocate was called on.
 	 */
 	NVME_QUIRK_DEALLOCATE_ZEROES		= (1 << 2),

 	/*
 	 * The controller needs a delay before starts checking the device
 	 * readiness, which is done by reading the NVME_CSTS_RDY bit.
 	 */
 	NVME_QUIRK_DELAY_BEFORE_CHK_RDY		= (1 << 3),

 	/*
 	 * APST should not be used.
 	 */
 	NVME_QUIRK_NO_APST			= (1 << 4),

 	/*
 	 * The deepest sleep state should not be used.
 	 */
 	NVME_QUIRK_NO_DEEPEST_PS		= (1 << 5),

 	/*
 	 * Supports the LighNVM command set if indicated in vs[1].
 	 */
 	NVME_QUIRK_LIGHTNVM			= (1 << 6),
 };

 /*
  * Common request structure for NVMe passthrough.  All drivers must have
  * this structure as the first member of their request-private data.
  */
 struct nvme_request {
 	struct nvme_command	*cmd;
 	union nvme_result	result;
 	u8			retries;
 	u8			flags;
 	u16			status;
 };

 /*
  * Mark a bio as coming in through the mpath node.
  */
 #define REQ_NVME_MPATH		REQ_DRV

 enum {
 	NVME_REQ_CANCELLED		= (1 << 0),
 };

 static inline struct nvme_request *nvme_req(struct request *req)
 {
 	return blk_mq_rq_to_pdu(req);
 }

 /* The below value is the specific amount of delay needed before checking
  * readiness in case of the PCI_DEVICE(0x1c58, 0x0003), which needs the
  * NVME_QUIRK_DELAY_BEFORE_CHK_RDY quirk enabled. The value (in ms) was
  * found empirically.
  */
 #define NVME_QUIRK_DELAY_AMOUNT		2300

 enum nvme_ctrl_state {
 	NVME_CTRL_NEW,
 	NVME_CTRL_LIVE,
 	NVME_CTRL_ADMIN_ONLY,    /* Only admin queue live */
 	NVME_CTRL_RESETTING,
 	NVME_CTRL_RECONNECTING,
 	NVME_CTRL_DELETING,
 	NVME_CTRL_DEAD,
 };

 struct nvme_ctrl {
 	enum nvme_ctrl_state state;
 	bool identified;
 	spinlock_t lock;
 	const struct nvme_ctrl_ops *ops;
 	struct request_queue *admin_q;
 	struct request_queue *connect_q;
 	struct device *dev;
 	int instance;
 	struct blk_mq_tag_set *tagset;
 	struct blk_mq_tag_set *admin_tagset;
 	struct list_head namespaces;
 	struct mutex namespaces_mutex;
 	struct device ctrl_device;
 	struct device *device;	/* char device */
 	struct cdev cdev;
 	struct work_struct reset_work;
 	struct work_struct delete_work;

 	struct nvme_subsystem *subsys;
 	struct list_head subsys_entry;

 	struct opal_dev *opal_dev;

 	char name[12];
 	u16 cntlid;

 	u32 ctrl_config;
 	u16 mtfa;
 	u32 queue_count;

 	u64 cap;
 	u32 page_size;
 	u32 max_hw_sectors;
 	u16 oncs;
 	u16 oacs;
 	u16 nssa;
 	u16 nr_streams;
 	atomic_t abort_limit;
 	u8 vwc;
 	u32 vs;
 	u32 sgls;
 	u16 kas;
 	u8 npss;
 	u8 apsta;
 	u32 aen_result;
 	unsigned int shutdown_timeout;
 	unsigned int kato;
 	bool subsystem;
 	unsigned long quirks;
 	struct nvme_id_power_state psd[32];
 	struct nvme_effects_log *effects;
 	struct work_struct scan_work;
 	struct work_struct async_event_work;
 	struct delayed_work ka_work;
 	struct work_struct fw_act_work;

 	/* Power saving configuration */
 	u64 ps_max_latency_us;
 	bool apst_enabled;

 	/* PCIe only: */
 	u32 hmpre;
 	u32 hmmin;
 	u32 hmminds;
 	u16 hmmaxd;

 	/* Fabrics only */
 	u16 sqsize;
 	u32 ioccsz;
 	u32 iorcsz;
 	u16 icdoff;
 	u16 maxcmd;
 	int nr_reconnects;
 	struct nvmf_ctrl_options *opts;
 };

 struct nvme_subsystem {
 	int			instance;
 	struct device		dev;
 	/*
 	 * Because we unregister the device on the last put we need
 	 * a separate refcount.
 	 */
 	struct kref		ref;
 	struct list_head	entry;
 	struct mutex		lock;
 	struct list_head	ctrls;
 	struct list_head	nsheads;
 	char			subnqn[NVMF_NQN_SIZE];
 	char			serial[20];
 	char			model[40];
 	char			firmware_rev[8];
 	u8			cmic;
 	u16			vendor_id;
 	struct ida		ns_ida;
 };

 /*
  * Container structure for uniqueue namespace identifiers.
  */
 struct nvme_ns_ids {
 	u8	eui64[8];
 	u8	nguid[16];
 	uuid_t	uuid;
 };

 /*
  * Anchor structure for namespaces.  There is one for each namespace in a
  * NVMe subsystem that any of our controllers can see, and the namespace
  * structure for each controller is chained of it.  For private namespaces
  * there is a 1:1 relation to our namespace structures, that is ->list
  * only ever has a single entry for private namespaces.
  */
 struct nvme_ns_head {
 #ifdef CONFIG_NVME_MULTIPATH
 	struct gendisk		*disk;
 	struct nvme_ns __rcu	*current_path;
 	struct bio_list		requeue_list;
 	spinlock_t		requeue_lock;
 	struct work_struct	requeue_work;
 #endif
 	struct list_head	list;
 	struct srcu_struct      srcu;
 	struct nvme_subsystem	*subsys;
 	unsigned		ns_id;
 	struct nvme_ns_ids	ids;
 	struct list_head	entry;
 	struct kref		ref;
 	int			instance;
 };

 struct nvme_ns {
 	struct list_head list;

 	struct nvme_ctrl *ctrl;
 	struct request_queue *queue;
 	struct gendisk *disk;
 	struct list_head siblings;
 	struct nvm_dev *ndev;
 	struct kref kref;
 	struct nvme_ns_head *head;

 	int lba_shift;
 	u16 ms;
 	u16 sgs;
 	u32 sws;
 	bool ext;
 	u8 pi_type;
 	unsigned long flags;
 #define NVME_NS_REMOVING 0
 #define NVME_NS_DEAD     1
 	u16 noiob;
 };

 struct nvme_ctrl_ops {
 	const char *name;
 	struct module *module;
 	unsigned int flags;
 #define NVME_F_FABRICS			(1 << 0)
 #define NVME_F_METADATA_SUPPORTED	(1 << 1)
 	int (*reg_read32)(struct nvme_ctrl *ctrl, u32 off, u32 *val);
 	int (*reg_write32)(struct nvme_ctrl *ctrl, u32 off, u32 val);
 	int (*reg_read64)(struct nvme_ctrl *ctrl, u32 off, u64 *val);
 	void (*free_ctrl)(struct nvme_ctrl *ctrl);
 	void (*submit_async_event)(struct nvme_ctrl *ctrl);
 	void (*delete_ctrl)(struct nvme_ctrl *ctrl);
 	int (*get_address)(struct nvme_ctrl *ctrl, char *buf, int size);
 	int (*reinit_request)(void *data, struct request *rq);
 };

 static inline bool nvme_ctrl_ready(struct nvme_ctrl *ctrl)
 {
 	u32 val = 0;

 	if (ctrl->ops->reg_read32(ctrl, NVME_REG_CSTS, &val))
 		return false;
 	return val & NVME_CSTS_RDY;
 }

 static inline int nvme_reset_subsystem(struct nvme_ctrl *ctrl)
 {
 	if (!ctrl->subsystem)
 		return -ENOTTY;
 	return ctrl->ops->reg_write32(ctrl, NVME_REG_NSSR, 0x4E564D65);
 }

 static inline u64 nvme_block_nr(struct nvme_ns *ns, sector_t sector)
 {
 	return (sector >> (ns->lba_shift - 9));
 }

 static inline void nvme_cleanup_cmd(struct request *req)
 {
 	if (req->rq_flags & RQF_SPECIAL_PAYLOAD) {
 		kfree(page_address(req->special_vec.bv_page) +
 		      req->special_vec.bv_offset);
 	}
 }

 static inline void nvme_end_request(struct request *req, __le16 status,
 		union nvme_result result)
 {
 	struct nvme_request *rq = nvme_req(req);

 	rq->status = le16_to_cpu(status) >> 1;
 	rq->result = result;
 	blk_mq_complete_request(req);
 }

 static inline void nvme_get_ctrl(struct nvme_ctrl *ctrl)
 {
 	get_device(ctrl->device);
 }

 static inline void nvme_put_ctrl(struct nvme_ctrl *ctrl)
 {
 	put_device(ctrl->device);
 }

 void nvme_complete_rq(struct request *req);
 void nvme_cancel_request(struct request *req, void *data, bool reserved);
 bool nvme_change_ctrl_state(struct nvme_ctrl *ctrl,
 		enum nvme_ctrl_state new_state);
 int nvme_disable_ctrl(struct nvme_ctrl *ctrl, u64 cap);
 int nvme_enable_ctrl(struct nvme_ctrl *ctrl, u64 cap);
 int nvme_shutdown_ctrl(struct nvme_ctrl *ctrl);
 int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev,
 		const struct nvme_ctrl_ops *ops, unsigned long quirks);
 void nvme_uninit_ctrl(struct nvme_ctrl *ctrl);
 void nvme_start_ctrl(struct nvme_ctrl *ctrl);
 void nvme_stop_ctrl(struct nvme_ctrl *ctrl);
 void nvme_put_ctrl(struct nvme_ctrl *ctrl);
 int nvme_init_identify(struct nvme_ctrl *ctrl);

 void nvme_queue_scan(struct nvme_ctrl *ctrl);
 void nvme_remove_namespaces(struct nvme_ctrl *ctrl);

 int nvme_sec_submit(void *data, u16 spsp, u8 secp, void *buffer, size_t len,
 		bool send);

 void nvme_complete_async_event(struct nvme_ctrl *ctrl, __le16 status,
 		union nvme_result *res);

 void nvme_stop_queues(struct nvme_ctrl *ctrl);
 void nvme_start_queues(struct nvme_ctrl *ctrl);
 void nvme_kill_queues(struct nvme_ctrl *ctrl);
 void nvme_unfreeze(struct nvme_ctrl *ctrl);
 void nvme_wait_freeze(struct nvme_ctrl *ctrl);
 void nvme_wait_freeze_timeout(struct nvme_ctrl *ctrl, long timeout);
 void nvme_start_freeze(struct nvme_ctrl *ctrl);
 int nvme_reinit_tagset(struct nvme_ctrl *ctrl, struct blk_mq_tag_set *set);

 #define NVME_QID_ANY -1
 struct request *nvme_alloc_request(struct request_queue *q,
 		struct nvme_command *cmd, blk_mq_req_flags_t flags, int qid);
 blk_status_t nvme_setup_cmd(struct nvme_ns *ns, struct request *req,
 		struct nvme_command *cmd);
 int nvme_submit_sync_cmd(struct request_queue *q, struct nvme_command *cmd,
 		void *buf, unsigned bufflen);
 int __nvme_submit_sync_cmd(struct request_queue *q, struct nvme_command *cmd,
 		union nvme_result *result, void *buffer, unsigned bufflen,
 		unsigned timeout, int qid, int at_head,
 		blk_mq_req_flags_t flags);
 int nvme_set_queue_count(struct nvme_ctrl *ctrl, int *count);
 void nvme_start_keep_alive(struct nvme_ctrl *ctrl);
 void nvme_stop_keep_alive(struct nvme_ctrl *ctrl);
 int nvme_reset_ctrl(struct nvme_ctrl *ctrl);
 int nvme_reset_ctrl_sync(struct nvme_ctrl *ctrl);
 int nvme_delete_ctrl(struct nvme_ctrl *ctrl);
 int nvme_delete_ctrl_sync(struct nvme_ctrl *ctrl);

 extern const struct attribute_group nvme_ns_id_attr_group;
 extern const struct block_device_operations nvme_ns_head_ops;

 #ifdef CONFIG_NVME_MULTIPATH
 void nvme_failover_req(struct request *req);
 bool nvme_req_needs_failover(struct request *req, blk_status_t error);
 void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl);
 int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl,struct nvme_ns_head *head);
 void nvme_mpath_add_disk(struct nvme_ns_head *head);
 void nvme_mpath_add_disk_links(struct nvme_ns *ns);
 void nvme_mpath_remove_disk(struct nvme_ns_head *head);
 void nvme_mpath_remove_disk_links(struct nvme_ns *ns);

 static inline void nvme_mpath_clear_current_path(struct nvme_ns *ns)
 {
 	struct nvme_ns_head *head = ns->head;

 	if (head && ns == srcu_dereference(head->current_path, &head->srcu))
 		rcu_assign_pointer(head->current_path, NULL);
 }
 struct nvme_ns *nvme_find_path(struct nvme_ns_head *head);

 static inline void nvme_mpath_check_last_path(struct nvme_ns *ns)
 {
 	struct nvme_ns_head *head = ns->head;

 	if (head->disk && list_empty(&head->list))
 		kblockd_schedule_work(&head->requeue_work);
 }

 #else
 static inline void nvme_failover_req(struct request *req)
 {
 }
 static inline bool nvme_req_needs_failover(struct request *req,
 					   blk_status_t error)
 {
 	return false;
 }
 static inline void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl)
 {
 }
 static inline int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl,
 		struct nvme_ns_head *head)
 {
 	return 0;
 }
 static inline void nvme_mpath_add_disk(struct nvme_ns_head *head)
 {
 }
 static inline void nvme_mpath_remove_disk(struct nvme_ns_head *head)
 {
 }
 static inline void nvme_mpath_add_disk_links(struct nvme_ns *ns)
 {
 }
 static inline void nvme_mpath_remove_disk_links(struct nvme_ns *ns)
 {
 }
 static inline void nvme_mpath_clear_current_path(struct nvme_ns *ns)
 {
 }
 static inline void nvme_mpath_check_last_path(struct nvme_ns *ns)
 {
 }
 #endif /* CONFIG_NVME_MULTIPATH */

 #ifdef CONFIG_NVM
 int nvme_nvm_register(struct nvme_ns *ns, char *disk_name, int node);
 void nvme_nvm_unregister(struct nvme_ns *ns);
 int nvme_nvm_register_sysfs(struct nvme_ns *ns);
 void nvme_nvm_unregister_sysfs(struct nvme_ns *ns);
 int nvme_nvm_ioctl(struct nvme_ns *ns, unsigned int cmd, unsigned long arg);
 #else
 static inline int nvme_nvm_register(struct nvme_ns *ns, char *disk_name,
 				    int node)
 {
 	return 0;
 }

 static inline void nvme_nvm_unregister(struct nvme_ns *ns) {};
 static inline int nvme_nvm_register_sysfs(struct nvme_ns *ns)
 {
 	return 0;
 }
 static inline void nvme_nvm_unregister_sysfs(struct nvme_ns *ns) {};
 static inline int nvme_nvm_ioctl(struct nvme_ns *ns, unsigned int cmd,
 							unsigned long arg)
 {
 	return -ENOTTY;
 }
 #endif /* CONFIG_NVM */

 static inline struct nvme_ns *nvme_get_ns_from_dev(struct device *dev)
 {
 	return dev_to_disk(dev)->private_data;
 }

 int __init nvme_core_init(void);
 void nvme_core_exit(void);

 #endif /* _NVME_H */
	/*
	* Copyright (c) 2011-2014, Intel Corporation.
	*
	* 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_H
	#define _NVME_H

	#include <linux/nvme.h>
	#include <linux/cdev.h>
	#include <linux/pci.h>
	#include <linux/kref.h>
	#include <linux/blk-mq.h>
	#include <linux/lightnvm.h>
	#include <linux/sed-opal.h>

	extern unsigned int nvme_io_timeout;
	#define NVME_IO_TIMEOUT (nvme_io_timeout * HZ)

	extern unsigned int admin_timeout;
	#define ADMIN_TIMEOUT (admin_timeout * HZ)

	#define NVME_DEFAULT_KATO 5
	#define NVME_KATO_GRACE 10

	extern struct workqueue_struct *nvme_wq;
	extern struct workqueue_struct *nvme_reset_wq;
	extern struct workqueue_struct *nvme_delete_wq;

	enum {
	NVME_NS_LBA = 0,
	NVME_NS_LIGHTNVM = 1,
	};

	/*
	* List of workarounds for devices that required behavior not specified in
	* the standard.
	*/
	enum nvme_quirks {
	/*
	* Prefers I/O aligned to a stripe size specified in a vendor
	* specific Identify field.
	*/
	NVME_QUIRK_STRIPE_SIZE = (1 << 0),

	/*
	* The controller doesn't handle Identify value others than 0 or 1
	* correctly.
	*/
	NVME_QUIRK_IDENTIFY_CNS = (1 << 1),

	/*
	* The controller deterministically returns O's on reads to
	* logical blocks that deallocate was called on.
	*/
	NVME_QUIRK_DEALLOCATE_ZEROES = (1 << 2),

	/*
	* The controller needs a delay before starts checking the device
	* readiness, which is done by reading the NVME_CSTS_RDY bit.
	*/
	NVME_QUIRK_DELAY_BEFORE_CHK_RDY = (1 << 3),

	/*
	* APST should not be used.
	*/
	NVME_QUIRK_NO_APST = (1 << 4),

	/*
	* The deepest sleep state should not be used.
	*/
	NVME_QUIRK_NO_DEEPEST_PS = (1 << 5),

	/*
	* Supports the LighNVM command set if indicated in vs[1].
	*/
	NVME_QUIRK_LIGHTNVM = (1 << 6),
	};

	/*
	* Common request structure for NVMe passthrough. All drivers must have
	* this structure as the first member of their request-private data.
	*/
	struct nvme_request {
	struct nvme_command *cmd;
	union nvme_result result;
	u8 retries;
	u8 flags;
	u16 status;
	};

	/*
	* Mark a bio as coming in through the mpath node.
	*/
	#define REQ_NVME_MPATH REQ_DRV

	enum {
	NVME_REQ_CANCELLED = (1 << 0),
	};

	static inline struct nvme_request nvme_req(struct request req)
	{
	return blk_mq_rq_to_pdu(req);
	}

	/* The below value is the specific amount of delay needed before checking
	* readiness in case of the PCI_DEVICE(0x1c58, 0x0003), which needs the
	* NVME_QUIRK_DELAY_BEFORE_CHK_RDY quirk enabled. The value (in ms) was
	* found empirically.
	*/
	#define NVME_QUIRK_DELAY_AMOUNT 2300

	enum nvme_ctrl_state {
	NVME_CTRL_NEW,
	NVME_CTRL_LIVE,
	NVME_CTRL_ADMIN_ONLY, /* Only admin queue live */
	NVME_CTRL_RESETTING,
	NVME_CTRL_RECONNECTING,
	NVME_CTRL_DELETING,
	NVME_CTRL_DEAD,
	};

	struct nvme_ctrl {
	enum nvme_ctrl_state state;
	bool identified;
	spinlock_t lock;
	const struct nvme_ctrl_ops *ops;
	struct request_queue *admin_q;
	struct request_queue *connect_q;
	struct device *dev;
	int instance;
	struct blk_mq_tag_set *tagset;
	struct blk_mq_tag_set *admin_tagset;
	struct list_head namespaces;
	struct mutex namespaces_mutex;
	struct device ctrl_device;
	struct device device; / char device */
	struct cdev cdev;
	struct work_struct reset_work;
	struct work_struct delete_work;

	struct nvme_subsystem *subsys;
	struct list_head subsys_entry;

	struct opal_dev *opal_dev;

	char name[12];
	u16 cntlid;

	u32 ctrl_config;
	u16 mtfa;
	u32 queue_count;

	u64 cap;
	u32 page_size;
	u32 max_hw_sectors;
	u16 oncs;
	u16 oacs;
	u16 nssa;
	u16 nr_streams;
	atomic_t abort_limit;
	u8 vwc;
	u32 vs;
	u32 sgls;
	u16 kas;
	u8 npss;
	u8 apsta;
	u32 aen_result;
	unsigned int shutdown_timeout;
	unsigned int kato;
	bool subsystem;
	unsigned long quirks;
	struct nvme_id_power_state psd[32];
	struct nvme_effects_log *effects;
	struct work_struct scan_work;
	struct work_struct async_event_work;
	struct delayed_work ka_work;
	struct work_struct fw_act_work;

	/* Power saving configuration */
	u64 ps_max_latency_us;
	bool apst_enabled;

	/* PCIe only: */
	u32 hmpre;
	u32 hmmin;
	u32 hmminds;
	u16 hmmaxd;

	/* Fabrics only */
	u16 sqsize;
	u32 ioccsz;
	u32 iorcsz;
	u16 icdoff;
	u16 maxcmd;
	int nr_reconnects;
	struct nvmf_ctrl_options *opts;
	};

	struct nvme_subsystem {
	int instance;
	struct device dev;
	/*
	* Because we unregister the device on the last put we need
	* a separate refcount.
	*/
	struct kref ref;
	struct list_head entry;
	struct mutex lock;
	struct list_head ctrls;
	struct list_head nsheads;
	char subnqn[NVMF_NQN_SIZE];
	char serial[20];
	char model[40];
	char firmware_rev[8];
	u8 cmic;
	u16 vendor_id;
	struct ida ns_ida;
	};

	/*
	* Container structure for uniqueue namespace identifiers.
	*/
	struct nvme_ns_ids {
	u8 eui64[8];
	u8 nguid[16];
	uuid_t uuid;
	};

	/*
	* Anchor structure for namespaces. There is one for each namespace in a
	* NVMe subsystem that any of our controllers can see, and the namespace
	* structure for each controller is chained of it. For private namespaces
	* there is a 1:1 relation to our namespace structures, that is ->list
	* only ever has a single entry for private namespaces.
	*/
	struct nvme_ns_head {
	#ifdef CONFIG_NVME_MULTIPATH
	struct gendisk *disk;
	struct nvme_ns __rcu *current_path;
	struct bio_list requeue_list;
	spinlock_t requeue_lock;
	struct work_struct requeue_work;
	#endif
	struct list_head list;
	struct srcu_struct srcu;
	struct nvme_subsystem *subsys;
	unsigned ns_id;
	struct nvme_ns_ids ids;
	struct list_head entry;
	struct kref ref;
	int instance;
	};

	struct nvme_ns {
	struct list_head list;

	struct nvme_ctrl *ctrl;
	struct request_queue *queue;
	struct gendisk *disk;
	struct list_head siblings;
	struct nvm_dev *ndev;
	struct kref kref;
	struct nvme_ns_head *head;

	int lba_shift;
	u16 ms;
	u16 sgs;
	u32 sws;
	bool ext;
	u8 pi_type;
	unsigned long flags;
	#define NVME_NS_REMOVING 0
	#define NVME_NS_DEAD 1
	u16 noiob;
	};

	struct nvme_ctrl_ops {
	const char *name;
	struct module *module;
	unsigned int flags;
	#define NVME_F_FABRICS (1 << 0)
	#define NVME_F_METADATA_SUPPORTED (1 << 1)
	int (reg_read32)(struct nvme_ctrl ctrl, u32 off, u32 *val);
	int (reg_write32)(struct nvme_ctrl ctrl, u32 off, u32 val);
	int (reg_read64)(struct nvme_ctrl ctrl, u32 off, u64 *val);
	void (free_ctrl)(struct nvme_ctrl ctrl);
	void (submit_async_event)(struct nvme_ctrl ctrl);
	void (delete_ctrl)(struct nvme_ctrl ctrl);
	int (get_address)(struct nvme_ctrl ctrl, char *buf, int size);
	int (reinit_request)(void data, struct request *rq);
	};

	static inline bool nvme_ctrl_ready(struct nvme_ctrl *ctrl)
	{
	u32 val = 0;

	if (ctrl->ops->reg_read32(ctrl, NVME_REG_CSTS, &val))
	return false;
	return val & NVME_CSTS_RDY;
	}

	static inline int nvme_reset_subsystem(struct nvme_ctrl *ctrl)
	{
	if (!ctrl->subsystem)
	return -ENOTTY;
	return ctrl->ops->reg_write32(ctrl, NVME_REG_NSSR, 0x4E564D65);
	}

	static inline u64 nvme_block_nr(struct nvme_ns *ns, sector_t sector)
	{
	return (sector >> (ns->lba_shift - 9));
	}

	static inline void nvme_cleanup_cmd(struct request *req)
	{
	if (req->rq_flags & RQF_SPECIAL_PAYLOAD) {
	kfree(page_address(req->special_vec.bv_page) +
	req->special_vec.bv_offset);
	}
	}

	static inline void nvme_end_request(struct request *req, __le16 status,
	union nvme_result result)
	{
	struct nvme_request *rq = nvme_req(req);

	rq->status = le16_to_cpu(status) >> 1;
	rq->result = result;
	blk_mq_complete_request(req);
	}

	static inline void nvme_get_ctrl(struct nvme_ctrl *ctrl)
	{
	get_device(ctrl->device);
	}

	static inline void nvme_put_ctrl(struct nvme_ctrl *ctrl)
	{
	put_device(ctrl->device);
	}

	void nvme_complete_rq(struct request *req);
	void nvme_cancel_request(struct request req, void data, bool reserved);
	bool nvme_change_ctrl_state(struct nvme_ctrl *ctrl,
	enum nvme_ctrl_state new_state);
	int nvme_disable_ctrl(struct nvme_ctrl *ctrl, u64 cap);
	int nvme_enable_ctrl(struct nvme_ctrl *ctrl, u64 cap);
	int nvme_shutdown_ctrl(struct nvme_ctrl *ctrl);
	int nvme_init_ctrl(struct nvme_ctrl ctrl, struct device dev,
	const struct nvme_ctrl_ops *ops, unsigned long quirks);
	void nvme_uninit_ctrl(struct nvme_ctrl *ctrl);
	void nvme_start_ctrl(struct nvme_ctrl *ctrl);
	void nvme_stop_ctrl(struct nvme_ctrl *ctrl);
	void nvme_put_ctrl(struct nvme_ctrl *ctrl);
	int nvme_init_identify(struct nvme_ctrl *ctrl);

	void nvme_queue_scan(struct nvme_ctrl *ctrl);
	void nvme_remove_namespaces(struct nvme_ctrl *ctrl);

	int nvme_sec_submit(void data, u16 spsp, u8 secp, void buffer, size_t len,
	bool send);

	void nvme_complete_async_event(struct nvme_ctrl *ctrl, __le16 status,
	union nvme_result *res);

	void nvme_stop_queues(struct nvme_ctrl *ctrl);
	void nvme_start_queues(struct nvme_ctrl *ctrl);
	void nvme_kill_queues(struct nvme_ctrl *ctrl);
	void nvme_unfreeze(struct nvme_ctrl *ctrl);
	void nvme_wait_freeze(struct nvme_ctrl *ctrl);
	void nvme_wait_freeze_timeout(struct nvme_ctrl *ctrl, long timeout);
	void nvme_start_freeze(struct nvme_ctrl *ctrl);
	int nvme_reinit_tagset(struct nvme_ctrl ctrl, struct blk_mq_tag_set set);

	#define NVME_QID_ANY -1
	struct request nvme_alloc_request(struct request_queue q,
	struct nvme_command *cmd, blk_mq_req_flags_t flags, int qid);
	blk_status_t nvme_setup_cmd(struct nvme_ns ns, struct request req,
	struct nvme_command *cmd);
	int nvme_submit_sync_cmd(struct request_queue q, struct nvme_command cmd,
	void *buf, unsigned bufflen);
	int __nvme_submit_sync_cmd(struct request_queue q, struct nvme_command cmd,
	union nvme_result result, void buffer, unsigned bufflen,
	unsigned timeout, int qid, int at_head,
	blk_mq_req_flags_t flags);
	int nvme_set_queue_count(struct nvme_ctrl ctrl, int count);
	void nvme_start_keep_alive(struct nvme_ctrl *ctrl);
	void nvme_stop_keep_alive(struct nvme_ctrl *ctrl);
	int nvme_reset_ctrl(struct nvme_ctrl *ctrl);
	int nvme_reset_ctrl_sync(struct nvme_ctrl *ctrl);
	int nvme_delete_ctrl(struct nvme_ctrl *ctrl);
	int nvme_delete_ctrl_sync(struct nvme_ctrl *ctrl);

	extern const struct attribute_group nvme_ns_id_attr_group;
	extern const struct block_device_operations nvme_ns_head_ops;

	#ifdef CONFIG_NVME_MULTIPATH
	void nvme_failover_req(struct request *req);
	bool nvme_req_needs_failover(struct request *req, blk_status_t error);
	void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl);
	int nvme_mpath_alloc_disk(struct nvme_ctrl ctrl,struct nvme_ns_head head);
	void nvme_mpath_add_disk(struct nvme_ns_head *head);
	void nvme_mpath_add_disk_links(struct nvme_ns *ns);
	void nvme_mpath_remove_disk(struct nvme_ns_head *head);
	void nvme_mpath_remove_disk_links(struct nvme_ns *ns);

	static inline void nvme_mpath_clear_current_path(struct nvme_ns *ns)
	{
	struct nvme_ns_head *head = ns->head;

	if (head && ns == srcu_dereference(head->current_path, &head->srcu))
	rcu_assign_pointer(head->current_path, NULL);
	}
	struct nvme_ns nvme_find_path(struct nvme_ns_head head);

	static inline void nvme_mpath_check_last_path(struct nvme_ns *ns)
	{
	struct nvme_ns_head *head = ns->head;

	if (head->disk && list_empty(&head->list))
	kblockd_schedule_work(&head->requeue_work);
	}

	#else
	static inline void nvme_failover_req(struct request *req)
	{
	}
	static inline bool nvme_req_needs_failover(struct request *req,
	blk_status_t error)
	{
	return false;
	}
	static inline void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl)
	{
	}
	static inline int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl,
	struct nvme_ns_head *head)
	{
	return 0;
	}
	static inline void nvme_mpath_add_disk(struct nvme_ns_head *head)
	{
	}
	static inline void nvme_mpath_remove_disk(struct nvme_ns_head *head)
	{
	}
	static inline void nvme_mpath_add_disk_links(struct nvme_ns *ns)
	{
	}
	static inline void nvme_mpath_remove_disk_links(struct nvme_ns *ns)
	{
	}
	static inline void nvme_mpath_clear_current_path(struct nvme_ns *ns)
	{
	}
	static inline void nvme_mpath_check_last_path(struct nvme_ns *ns)
	{
	}
	#endif /* CONFIG_NVME_MULTIPATH */

	#ifdef CONFIG_NVM
	int nvme_nvm_register(struct nvme_ns ns, char disk_name, int node);
	void nvme_nvm_unregister(struct nvme_ns *ns);
	int nvme_nvm_register_sysfs(struct nvme_ns *ns);
	void nvme_nvm_unregister_sysfs(struct nvme_ns *ns);
	int nvme_nvm_ioctl(struct nvme_ns *ns, unsigned int cmd, unsigned long arg);
	#else
	static inline int nvme_nvm_register(struct nvme_ns ns, char disk_name,
	int node)
	{
	return 0;
	}

	static inline void nvme_nvm_unregister(struct nvme_ns *ns) {};
	static inline int nvme_nvm_register_sysfs(struct nvme_ns *ns)
	{
	return 0;
	}
	static inline void nvme_nvm_unregister_sysfs(struct nvme_ns *ns) {};
	static inline int nvme_nvm_ioctl(struct nvme_ns *ns, unsigned int cmd,
	unsigned long arg)
	{
	return -ENOTTY;
	}
	#endif /* CONFIG_NVM */

	static inline struct nvme_ns nvme_get_ns_from_dev(struct device dev)
	{
	return dev_to_disk(dev)->private_data;
	}

	int __init nvme_core_init(void);
	void nvme_core_exit(void);

	#endif /* _NVME_H */