/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (c) 2015-2016 HGST, a Western Digital Company.
 */

#ifndef _NVMET_H
#define _NVMET_H

#include <linux/dma-mapping.h>
#include <linux/types.h>
#include <linux/device.h>
#include <linux/kref.h>
#include <linux/percpu-refcount.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/uuid.h>
#include <linux/nvme.h>
#include <linux/configfs.h>
#include <linux/rcupdate.h>
#include <linux/blkdev.h>
#include <linux/radix-tree.h>

#define NVMET_ASYNC_EVENTS              4
#define NVMET_ERROR_LOG_SLOTS           128
#define NVMET_NO_ERROR_LOC              ((u16)-1)

/*
 * Supported optional AENs:
 */
#define NVMET_AEN_CFG_OPTIONAL \
        (NVME_AEN_CFG_NS_ATTR | NVME_AEN_CFG_ANA_CHANGE)
#define NVMET_DISC_AEN_CFG_OPTIONAL \
        (NVME_AEN_CFG_DISC_CHANGE)

/*
 * Plus mandatory SMART AENs (we'll never send them, but allow enabling them):
 */
#define NVMET_AEN_CFG_ALL \
        (NVME_SMART_CRIT_SPARE | NVME_SMART_CRIT_TEMPERATURE | \
         NVME_SMART_CRIT_RELIABILITY | NVME_SMART_CRIT_MEDIA | \
         NVME_SMART_CRIT_VOLATILE_MEMORY | NVMET_AEN_CFG_OPTIONAL)

/* Helper Macros when NVMe error is NVME_SC_CONNECT_INVALID_PARAM
 * The 16 bit shift is to set IATTR bit to 1, which means offending
 * offset starts in the data section of connect()
 */
#define IPO_IATTR_CONNECT_DATA(x)       \
        (cpu_to_le32((1 << 16) | (offsetof(struct nvmf_connect_data, x))))
#define IPO_IATTR_CONNECT_SQE(x)        \
        (cpu_to_le32(offsetof(struct nvmf_connect_command, x)))

struct nvmet_ns {
        struct list_head        dev_link;
        struct percpu_ref       ref;
        struct block_device     *bdev;
        struct file             *file;
        bool                    readonly;
        u32                     nsid;
        u32                     blksize_shift;
        loff_t                  size;
        u8                      nguid[16];
        uuid_t                  uuid;
        u32                     anagrpid;

        bool                    buffered_io;
        bool                    enabled;
        struct nvmet_subsys     *subsys;
        const char              *device_path;

        struct config_group     device_group;
        struct config_group     group;

        struct completion       disable_done;
        mempool_t               *bvec_pool;
        struct kmem_cache       *bvec_cache;

        int                     use_p2pmem;
        struct pci_dev          *p2p_dev;
};

static inline struct nvmet_ns *to_nvmet_ns(struct config_item *item)
{
        return container_of(to_config_group(item), struct nvmet_ns, group);
}

static inline struct device *nvmet_ns_dev(struct nvmet_ns *ns)
{
        return ns->bdev ? disk_to_dev(ns->bdev->bd_disk) : NULL;
}

struct nvmet_cq {
        u16                     qid;
        u16                     size;
};

struct nvmet_sq {
        struct nvmet_ctrl       *ctrl;
        struct percpu_ref       ref;
        u16                     qid;
        u16                     size;
        u32                     sqhd;
        bool                    sqhd_disabled;
        struct completion       free_done;
        struct completion       confirm_done;
};

struct nvmet_ana_group {
        struct config_group     group;
        struct nvmet_port       *port;
        u32                     grpid;
};

static inline struct nvmet_ana_group *to_ana_group(struct config_item *item)
{
        return container_of(to_config_group(item), struct nvmet_ana_group,
                        group);
}

/**
 * struct nvmet_port -  Common structure to keep port
 *                              information for the target.
 * @entry:              Entry into referrals or transport list.
 * @disc_addr:          Address information is stored in a format defined
 *                              for a discovery log page entry.
 * @group:              ConfigFS group for this element's folder.
 * @priv:               Private data for the transport.
 */
struct nvmet_port {
        struct list_head                entry;
        struct nvmf_disc_rsp_page_entry disc_addr;
        struct config_group             group;
        struct config_group             subsys_group;
        struct list_head                subsystems;
        struct config_group             referrals_group;
        struct list_head                referrals;
        struct list_head                global_entry;
        struct config_group             ana_groups_group;
        struct nvmet_ana_group          ana_default_group;
        enum nvme_ana_state             *ana_state;
        void                            *priv;
        bool                            enabled;
        int                             inline_data_size;
};

static inline struct nvmet_port *to_nvmet_port(struct config_item *item)
{
        return container_of(to_config_group(item), struct nvmet_port,
                        group);
}

static inline struct nvmet_port *ana_groups_to_port(
                struct config_item *item)
{
        return container_of(to_config_group(item), struct nvmet_port,
                        ana_groups_group);
}

struct nvmet_ctrl {
        struct nvmet_subsys     *subsys;
        struct nvmet_cq         **cqs;
        struct nvmet_sq         **sqs;

        bool                    cmd_seen;

        struct mutex            lock;
        u64                     cap;
        u32                     cc;
        u32                     csts;

        uuid_t                  hostid;
        u16                     cntlid;
        u32                     kato;

        struct nvmet_port       *port;

        u32                     aen_enabled;
        unsigned long           aen_masked;
        struct nvmet_req        *async_event_cmds[NVMET_ASYNC_EVENTS];
        unsigned int            nr_async_event_cmds;
        struct list_head        async_events;
        struct work_struct      async_event_work;

        struct list_head        subsys_entry;
        struct kref             ref;
        struct delayed_work     ka_work;
        struct work_struct      fatal_err_work;

        const struct nvmet_fabrics_ops *ops;

        __le32                  *changed_ns_list;
        u32                     nr_changed_ns;

        char                    subsysnqn[NVMF_NQN_FIELD_LEN];
        char                    hostnqn[NVMF_NQN_FIELD_LEN];

        struct device           *p2p_client;
        struct radix_tree_root  p2p_ns_map;

        spinlock_t              error_lock;
        u64                     err_counter;
        struct nvme_error_slot  slots[NVMET_ERROR_LOG_SLOTS];
};

struct nvmet_subsys {
        enum nvme_subsys_type   type;

        struct mutex            lock;
        struct kref             ref;

        struct list_head        namespaces;
        unsigned int            nr_namespaces;
        unsigned int            max_nsid;

        struct list_head        ctrls;

        struct list_head        hosts;
        bool                    allow_any_host;

        u16                     max_qid;

        u64                     ver;
        u64                     serial;
        char                    *subsysnqn;

        struct config_group     group;

        struct config_group     namespaces_group;
        struct config_group     allowed_hosts_group;
};

static inline struct nvmet_subsys *to_subsys(struct config_item *item)
{
        return container_of(to_config_group(item), struct nvmet_subsys, group);
}

static inline struct nvmet_subsys *namespaces_to_subsys(
                struct config_item *item)
{
        return container_of(to_config_group(item), struct nvmet_subsys,
                        namespaces_group);
}

struct nvmet_host {
        struct config_group     group;
};

static inline struct nvmet_host *to_host(struct config_item *item)
{
        return container_of(to_config_group(item), struct nvmet_host, group);
}

static inline char *nvmet_host_name(struct nvmet_host *host)
{
        return config_item_name(&host->group.cg_item);
}

struct nvmet_host_link {
        struct list_head        entry;
        struct nvmet_host       *host;
};

struct nvmet_subsys_link {
        struct list_head        entry;
        struct nvmet_subsys     *subsys;
};

struct nvmet_req;
struct nvmet_fabrics_ops {
        struct module *owner;
        unsigned int type;
        unsigned int msdbd;
        bool has_keyed_sgls : 1;
        void (*queue_response)(struct nvmet_req *req);
        int (*add_port)(struct nvmet_port *port);
        void (*remove_port)(struct nvmet_port *port);
        void (*delete_ctrl)(struct nvmet_ctrl *ctrl);
        void (*disc_traddr)(struct nvmet_req *req,
                        struct nvmet_port *port, char *traddr);
        u16 (*install_queue)(struct nvmet_sq *nvme_sq);
};

#define NVMET_MAX_INLINE_BIOVEC 8
#define NVMET_MAX_INLINE_DATA_LEN NVMET_MAX_INLINE_BIOVEC * PAGE_SIZE

struct nvmet_req {
        struct nvme_command     *cmd;
        struct nvme_completion  *rsp;
        struct nvmet_sq         *sq;
        struct nvmet_cq         *cq;
        struct nvmet_ns         *ns;
        struct scatterlist      *sg;
        struct bio_vec          inline_bvec[NVMET_MAX_INLINE_BIOVEC];
        union {
                struct {
                        struct bio      inline_bio;
                } b;
                struct {
                        bool                    mpool_alloc;
                        struct kiocb            iocb;
                        struct bio_vec          *bvec;
                        struct work_struct      work;
                } f;
        };
        int                     sg_cnt;
        /* data length as parsed from the command: */
        size_t                  data_len;
        /* data length as parsed from the SGL descriptor: */
        size_t                  transfer_len;

        struct nvmet_port       *port;

        void (*execute)(struct nvmet_req *req);
        const struct nvmet_fabrics_ops *ops;

        struct pci_dev          *p2p_dev;
        struct device           *p2p_client;
        u16                     error_loc;
        u64                     error_slba;
};

extern struct workqueue_struct *buffered_io_wq;

static inline void nvmet_set_result(struct nvmet_req *req, u32 result)
{
        req->rsp->result.u32 = cpu_to_le32(result);
}

/*
 * NVMe command writes actually are DMA reads for us on the target side.
 */
static inline enum dma_data_direction
nvmet_data_dir(struct nvmet_req *req)
{
        return nvme_is_write(req->cmd) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
}

struct nvmet_async_event {
        struct list_head        entry;
        u8                      event_type;
        u8                      event_info;
        u8                      log_page;
};

static inline void nvmet_clear_aen_bit(struct nvmet_req *req, u32 bn)
{
        int rae = le32_to_cpu(req->cmd->common.cdw10) & 1 << 15;

        if (!rae)
                clear_bit(bn, &req->sq->ctrl->aen_masked);
}

static inline bool nvmet_aen_bit_disabled(struct nvmet_ctrl *ctrl, u32 bn)
{
        if (!(READ_ONCE(ctrl->aen_enabled) & (1 << bn)))
                return true;
        return test_and_set_bit(bn, &ctrl->aen_masked);
}

void nvmet_get_feat_kato(struct nvmet_req *req);
void nvmet_get_feat_async_event(struct nvmet_req *req);
u16 nvmet_set_feat_kato(struct nvmet_req *req);
u16 nvmet_set_feat_async_event(struct nvmet_req *req, u32 mask);
void nvmet_execute_async_event(struct nvmet_req *req);

u16 nvmet_parse_connect_cmd(struct nvmet_req *req);
u16 nvmet_bdev_parse_io_cmd(struct nvmet_req *req);
u16 nvmet_file_parse_io_cmd(struct nvmet_req *req);
u16 nvmet_parse_admin_cmd(struct nvmet_req *req);
u16 nvmet_parse_discovery_cmd(struct nvmet_req *req);
u16 nvmet_parse_fabrics_cmd(struct nvmet_req *req);

bool nvmet_req_init(struct nvmet_req *req, struct nvmet_cq *cq,
                struct nvmet_sq *sq, const struct nvmet_fabrics_ops *ops);
void nvmet_req_uninit(struct nvmet_req *req);
void nvmet_req_execute(struct nvmet_req *req);
void nvmet_req_complete(struct nvmet_req *req, u16 status);
int nvmet_req_alloc_sgl(struct nvmet_req *req);
void nvmet_req_free_sgl(struct nvmet_req *req);

void nvmet_execute_keep_alive(struct nvmet_req *req);

void nvmet_cq_setup(struct nvmet_ctrl *ctrl, struct nvmet_cq *cq, u16 qid,
                u16 size);
void nvmet_sq_setup(struct nvmet_ctrl *ctrl, struct nvmet_sq *sq, u16 qid,
                u16 size);
void nvmet_sq_destroy(struct nvmet_sq *sq);
int nvmet_sq_init(struct nvmet_sq *sq);

void nvmet_ctrl_fatal_error(struct nvmet_ctrl *ctrl);

void nvmet_update_cc(struct nvmet_ctrl *ctrl, u32 new);
u16 nvmet_alloc_ctrl(const char *subsysnqn, const char *hostnqn,
                struct nvmet_req *req, u32 kato, struct nvmet_ctrl **ctrlp);
u16 nvmet_ctrl_find_get(const char *subsysnqn, const char *hostnqn, u16 cntlid,
                struct nvmet_req *req, struct nvmet_ctrl **ret);
void nvmet_ctrl_put(struct nvmet_ctrl *ctrl);
u16 nvmet_check_ctrl_status(struct nvmet_req *req, struct nvme_command *cmd);

struct nvmet_subsys *nvmet_subsys_alloc(const char *subsysnqn,
                enum nvme_subsys_type type);
void nvmet_subsys_put(struct nvmet_subsys *subsys);
void nvmet_subsys_del_ctrls(struct nvmet_subsys *subsys);

struct nvmet_ns *nvmet_find_namespace(struct nvmet_ctrl *ctrl, __le32 nsid);
void nvmet_put_namespace(struct nvmet_ns *ns);
int nvmet_ns_enable(struct nvmet_ns *ns);
void nvmet_ns_disable(struct nvmet_ns *ns);
struct nvmet_ns *nvmet_ns_alloc(struct nvmet_subsys *subsys, u32 nsid);
void nvmet_ns_free(struct nvmet_ns *ns);

void nvmet_send_ana_event(struct nvmet_subsys *subsys,
                struct nvmet_port *port);
void nvmet_port_send_ana_event(struct nvmet_port *port);

int nvmet_register_transport(const struct nvmet_fabrics_ops *ops);
void nvmet_unregister_transport(const struct nvmet_fabrics_ops *ops);

int nvmet_enable_port(struct nvmet_port *port);
void nvmet_disable_port(struct nvmet_port *port);

void nvmet_referral_enable(struct nvmet_port *parent, struct nvmet_port *port);
void nvmet_referral_disable(struct nvmet_port *parent, struct nvmet_port *port);

u16 nvmet_copy_to_sgl(struct nvmet_req *req, off_t off, const void *buf,
                size_t len);
u16 nvmet_copy_from_sgl(struct nvmet_req *req, off_t off, void *buf,
                size_t len);
u16 nvmet_zero_sgl(struct nvmet_req *req, off_t off, size_t len);

u32 nvmet_get_log_page_len(struct nvme_command *cmd);
u64 nvmet_get_log_page_offset(struct nvme_command *cmd);

extern struct list_head *nvmet_ports;
void nvmet_port_disc_changed(struct nvmet_port *port,
                struct nvmet_subsys *subsys);
void nvmet_subsys_disc_changed(struct nvmet_subsys *subsys,
                struct nvmet_host *host);
void nvmet_add_async_event(struct nvmet_ctrl *ctrl, u8 event_type,
                u8 event_info, u8 log_page);

#define NVMET_QUEUE_SIZE        1024
#define NVMET_NR_QUEUES         128
#define NVMET_MAX_CMD           NVMET_QUEUE_SIZE

/*
 * Nice round number that makes a list of nsids fit into a page.
 * Should become tunable at some point in the future.
 */
#define NVMET_MAX_NAMESPACES    1024

/*
 * 0 is not a valid ANA group ID, so we start numbering at 1.
 *
 * ANA Group 1 exists without manual intervention, has namespaces assigned to it
 * by default, and is available in an optimized state through all ports.
 */
#define NVMET_MAX_ANAGRPS       128
#define NVMET_DEFAULT_ANA_GRPID 1

#define NVMET_KAS               10
#define NVMET_DISC_KATO_MS              120000

int __init nvmet_init_configfs(void);
void __exit nvmet_exit_configfs(void);

int __init nvmet_init_discovery(void);
void nvmet_exit_discovery(void);

extern struct nvmet_subsys *nvmet_disc_subsys;
extern struct rw_semaphore nvmet_config_sem;

extern u32 nvmet_ana_group_enabled[NVMET_MAX_ANAGRPS + 1];
extern u64 nvmet_ana_chgcnt;
extern struct rw_semaphore nvmet_ana_sem;

bool nvmet_host_allowed(struct nvmet_subsys *subsys, const char *hostnqn);

int nvmet_bdev_ns_enable(struct nvmet_ns *ns);
int nvmet_file_ns_enable(struct nvmet_ns *ns);
void nvmet_bdev_ns_disable(struct nvmet_ns *ns);
void nvmet_file_ns_disable(struct nvmet_ns *ns);
u16 nvmet_bdev_flush(struct nvmet_req *req);
u16 nvmet_file_flush(struct nvmet_req *req);
void nvmet_ns_changed(struct nvmet_subsys *subsys, u32 nsid);

static inline u32 nvmet_rw_len(struct nvmet_req *req)
{
        return ((u32)le16_to_cpu(req->cmd->rw.length) + 1) <<
                        req->ns->blksize_shift;
}

u16 errno_to_nvme_status(struct nvmet_req *req, int errno);
#endif /* _NVMET_H */