/* SPDX-License-Identifier: GPL-2.0 */
#ifndef TARGET_CORE_FABRIC_H
#define TARGET_CORE_FABRIC_H

#include <linux/configfs.h>
#include <linux/types.h>
#include <target/target_core_base.h>

struct target_core_fabric_ops {
        struct module *module;
        /*
         * XXX: Special case for iscsi/iSCSI...
         * If non-null, fabric_alias is used for matching target/$fabric
         * ConfigFS paths. If null, fabric_name is used for this (see below).
         */
        const char *fabric_alias;
        /*
         * fabric_name is used for matching target/$fabric ConfigFS paths
         * without a fabric_alias (see above). It's also used for the ALUA state
         * path and is stored on disk with PR state.
         */
        const char *fabric_name;
        size_t node_acl_size;
        /*
         * Limits number of scatterlist entries per SCF_SCSI_DATA_CDB payload.
         * Setting this value tells target-core to enforce this limit, and
         * report as INQUIRY EVPD=b0 MAXIMUM TRANSFER LENGTH.
         *
         * target-core will currently reset se_cmd->data_length to this
         * maximum size, and set UNDERFLOW residual count if length exceeds
         * this limit.
         *
         * XXX: Not all initiator hosts honor this block-limit EVPD
         * XXX: Currently assumes single PAGE_SIZE per scatterlist entry
         */
        u32 max_data_sg_nents;
        char *(*tpg_get_wwn)(struct se_portal_group *);
        u16 (*tpg_get_tag)(struct se_portal_group *);
        u32 (*tpg_get_default_depth)(struct se_portal_group *);
        int (*tpg_check_demo_mode)(struct se_portal_group *);
        int (*tpg_check_demo_mode_cache)(struct se_portal_group *);
        int (*tpg_check_demo_mode_write_protect)(struct se_portal_group *);
        int (*tpg_check_prod_mode_write_protect)(struct se_portal_group *);
        /*
         * Optionally used by fabrics to allow demo-mode login, but not
         * expose any TPG LUNs, and return 'not connected' in standard
         * inquiry response
         */
        int (*tpg_check_demo_mode_login_only)(struct se_portal_group *);
        /*
         * Optionally used as a configfs tunable to determine when
         * target-core should signal the PROTECT=1 feature bit for
         * backends that don't support T10-PI, so that either fabric
         * HW offload or target-core emulation performs the associated
         * WRITE_STRIP and READ_INSERT operations.
         */
        int (*tpg_check_prot_fabric_only)(struct se_portal_group *);
        u32 (*tpg_get_inst_index)(struct se_portal_group *);
        /*
         * Optional to release struct se_cmd and fabric dependent allocated
         * I/O descriptor after command execution has finished.
         *
         * Returning 1 will signal a descriptor has been released.
         * Returning 0 will signal a descriptor has not been released.
         */
        int (*check_stop_free)(struct se_cmd *);
        void (*release_cmd)(struct se_cmd *);
        void (*close_session)(struct se_session *);
        u32 (*sess_get_index)(struct se_session *);
        /*
         * Used only for SCSI fabrics that contain multi-value TransportIDs
         * (like iSCSI).  All other SCSI fabrics should set this to NULL.
         */
        u32 (*sess_get_initiator_sid)(struct se_session *,
                                      unsigned char *, u32);
        int (*write_pending)(struct se_cmd *);
        void (*set_default_node_attributes)(struct se_node_acl *);
        int (*get_cmd_state)(struct se_cmd *);
        int (*queue_data_in)(struct se_cmd *);
        int (*queue_status)(struct se_cmd *);
        void (*queue_tm_rsp)(struct se_cmd *);
        void (*aborted_task)(struct se_cmd *);
        /*
         * fabric module calls for target_core_fabric_configfs.c
         */
        struct se_wwn *(*fabric_make_wwn)(struct target_fabric_configfs *,
                                struct config_group *, const char *);
        void (*fabric_drop_wwn)(struct se_wwn *);
        void (*add_wwn_groups)(struct se_wwn *);
        struct se_portal_group *(*fabric_make_tpg)(struct se_wwn *,
                                                   const char *);
        int (*fabric_enable_tpg)(struct se_portal_group *se_tpg, bool enable);
        void (*fabric_drop_tpg)(struct se_portal_group *);
        int (*fabric_post_link)(struct se_portal_group *,
                                struct se_lun *);
        void (*fabric_pre_unlink)(struct se_portal_group *,
                                struct se_lun *);
        struct se_tpg_np *(*fabric_make_np)(struct se_portal_group *,
                                struct config_group *, const char *);
        void (*fabric_drop_np)(struct se_tpg_np *);
        int (*fabric_init_nodeacl)(struct se_node_acl *, const char *);

        struct configfs_attribute **tfc_discovery_attrs;
        struct configfs_attribute **tfc_wwn_attrs;
        struct configfs_attribute **tfc_tpg_base_attrs;
        struct configfs_attribute **tfc_tpg_np_base_attrs;
        struct configfs_attribute **tfc_tpg_attrib_attrs;
        struct configfs_attribute **tfc_tpg_auth_attrs;
        struct configfs_attribute **tfc_tpg_param_attrs;
        struct configfs_attribute **tfc_tpg_nacl_base_attrs;
        struct configfs_attribute **tfc_tpg_nacl_attrib_attrs;
        struct configfs_attribute **tfc_tpg_nacl_auth_attrs;
        struct configfs_attribute **tfc_tpg_nacl_param_attrs;

        /*
         * Set this member variable if the SCSI transport protocol
         * (e.g. iSCSI) requires that the Data-Out buffer is transferred in
         * its entirety before a command is aborted.
         */
        unsigned int write_pending_must_be_called:1;
        /*
         * Set this if the driver supports submitting commands to the backend
         * from target_submit/target_submit_cmd.
         */
        unsigned int direct_submit_supp:1;
        /*
         * Set this to a target_submit_type value.
         */
        u8 default_submit_type;
};

int target_register_template(const struct target_core_fabric_ops *fo);
void target_unregister_template(const struct target_core_fabric_ops *fo);

int target_depend_item(struct config_item *item);
void target_undepend_item(struct config_item *item);

struct se_session *target_setup_session(struct se_portal_group *,
                unsigned int, unsigned int, enum target_prot_op prot_op,
                const char *, void *,
                int (*callback)(struct se_portal_group *,
                                struct se_session *, void *));
void target_remove_session(struct se_session *);

void target_stop_cmd_counter(struct target_cmd_counter *cmd_cnt);
void target_wait_for_cmds(struct target_cmd_counter *cmd_cnt);
struct target_cmd_counter *target_alloc_cmd_counter(void);
void target_free_cmd_counter(struct target_cmd_counter *cmd_cnt);

void transport_init_session(struct se_session *se_sess);
struct se_session *transport_alloc_session(enum target_prot_op);
int transport_alloc_session_tags(struct se_session *, unsigned int,
                unsigned int);
void    __transport_register_session(struct se_portal_group *,
                struct se_node_acl *, struct se_session *, void *);
void    transport_register_session(struct se_portal_group *,
                struct se_node_acl *, struct se_session *, void *);
ssize_t target_show_dynamic_sessions(struct se_portal_group *, char *);
void    transport_free_session(struct se_session *);
void    target_spc2_release(struct se_node_acl *nacl);
void    target_put_nacl(struct se_node_acl *);
void    transport_deregister_session_configfs(struct se_session *);
void    transport_deregister_session(struct se_session *);


void    __target_init_cmd(struct se_cmd *cmd,
                const struct target_core_fabric_ops *tfo,
                struct se_session *sess, u32 data_length, int data_direction,
                int task_attr, unsigned char *sense_buffer, u64 unpacked_lun,
                struct target_cmd_counter *cmd_cnt);
int     target_init_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
                unsigned char *sense, u64 unpacked_lun, u32 data_length,
                int task_attr, int data_dir, int flags);
int     target_submit_prep(struct se_cmd *se_cmd, unsigned char *cdb,
                struct scatterlist *sgl, u32 sgl_count,
                struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
                struct scatterlist *sgl_prot, u32 sgl_prot_count, gfp_t gfp);
int     target_submit(struct se_cmd *se_cmd);
sense_reason_t transport_lookup_cmd_lun(struct se_cmd *);
sense_reason_t target_cmd_init_cdb(struct se_cmd *se_cmd, unsigned char *cdb,
                                   gfp_t gfp);
sense_reason_t target_cmd_parse_cdb(struct se_cmd *);
void    target_submit_cmd(struct se_cmd *, struct se_session *, unsigned char *,
                unsigned char *, u64, u32, int, int, int);

int     target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
                unsigned char *sense, u64 unpacked_lun,
                void *fabric_tmr_ptr, unsigned char tm_type,
                gfp_t, u64, int);
sense_reason_t  transport_generic_new_cmd(struct se_cmd *);

void    target_put_cmd_and_wait(struct se_cmd *cmd);
void    target_execute_cmd(struct se_cmd *cmd);

int     transport_generic_free_cmd(struct se_cmd *, int);

bool    transport_wait_for_tasks(struct se_cmd *);
int     transport_send_check_condition_and_sense(struct se_cmd *,
                sense_reason_t, int);
int     target_send_busy(struct se_cmd *cmd);
int     target_get_sess_cmd(struct se_cmd *, bool);
int     target_put_sess_cmd(struct se_cmd *);
void    target_stop_session(struct se_session *se_sess);
void    target_wait_for_sess_cmds(struct se_session *);
void    target_show_cmd(const char *pfx, struct se_cmd *cmd);

int     core_tmr_alloc_req(struct se_cmd *, void *, u8, gfp_t);
void    core_tmr_release_req(struct se_tmr_req *);
int     transport_generic_handle_tmr(struct se_cmd *);
void    transport_generic_request_failure(struct se_cmd *, sense_reason_t);
int     transport_lookup_tmr_lun(struct se_cmd *);
void    core_allocate_nexus_loss_ua(struct se_node_acl *acl);

struct se_node_acl *core_tpg_get_initiator_node_acl(struct se_portal_group *tpg,
                unsigned char *);
bool    target_tpg_has_node_acl(struct se_portal_group *tpg,
                const char *);
struct se_node_acl *core_tpg_check_initiator_node_acl(struct se_portal_group *,
                unsigned char *);
int     core_tpg_set_initiator_node_queue_depth(struct se_node_acl *, u32);
int     core_tpg_set_initiator_node_tag(struct se_portal_group *,
                struct se_node_acl *, const char *);
int     core_tpg_register(struct se_wwn *, struct se_portal_group *, int);
int     core_tpg_deregister(struct se_portal_group *);

int     target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents,
                u32 length, bool zero_page, bool chainable);
void    target_free_sgl(struct scatterlist *sgl, int nents);

/*
 * The LIO target core uses DMA_TO_DEVICE to mean that data is going
 * to the target (eg handling a WRITE) and DMA_FROM_DEVICE to mean
 * that data is coming from the target (eg handling a READ).  However,
 * this is just the opposite of what we have to tell the DMA mapping
 * layer -- eg when handling a READ, the HBA will have to DMA the data
 * out of memory so it can send it to the initiator, which means we
 * need to use DMA_TO_DEVICE when we map the data.
 */
static inline enum dma_data_direction
target_reverse_dma_direction(struct se_cmd *se_cmd)
{
        if (se_cmd->se_cmd_flags & SCF_BIDI)
                return DMA_BIDIRECTIONAL;

        switch (se_cmd->data_direction) {
        case DMA_TO_DEVICE:
                return DMA_FROM_DEVICE;
        case DMA_FROM_DEVICE:
                return DMA_TO_DEVICE;
        case DMA_NONE:
        default:
                return DMA_NONE;
        }
}

#endif /* TARGET_CORE_FABRICH */