/* SPDX-License-Identifier: GPL-2.0 */

  #ifndef TARGET_CORE_BACKEND_H
  #define TARGET_CORE_BACKEND_H

  #include <linux/types.h>

  #include <asm/unaligned.h>

  #include <target/target_core_base.h>

  #define TRANSPORT_FLAG_PASSTHROUGH		0x1
  /*
   * ALUA commands, state checks and setup operations are handled by the
   * backend module.
   */
  #define TRANSPORT_FLAG_PASSTHROUGH_ALUA		0x2

  #define TRANSPORT_FLAG_PASSTHROUGH_PGR          0x4

  struct request_queue;
  struct scatterlist;

  struct target_backend_ops {

  	char name[16];

  	char inquiry_prod[16];
  	char inquiry_rev[4];

  	struct module *owner;

  	u8 transport_flags_default;

  	u8 transport_flags_changeable;

  	int (*attach_hba)(struct se_hba *, u32);
  	void (*detach_hba)(struct se_hba *);
  	int (*pmode_enable_hba)(struct se_hba *, unsigned long);

  
  	struct se_device *(*alloc_device)(struct se_hba *, const char *);
  	int (*configure_device)(struct se_device *);

  	void (*destroy_device)(struct se_device *);

  	void (*free_device)(struct se_device *device);
  
  	ssize_t (*set_configfs_dev_params)(struct se_device *,
  					   const char *, ssize_t);
  	ssize_t (*show_configfs_dev_params)(struct se_device *, char *);

  	sense_reason_t (*parse_cdb)(struct se_cmd *cmd);

  	void (*tmr_notify)(struct se_device *se_dev, enum tcm_tmreq_table,
  			   struct list_head *aborted_cmds);

  	u32 (*get_device_type)(struct se_device *);
  	sector_t (*get_blocks)(struct se_device *);

  	sector_t (*get_alignment_offset_lbas)(struct se_device *);
  	/* lbppbe = logical blocks per physical block exponent. see SBC-3 */
  	unsigned int (*get_lbppbe)(struct se_device *);
  	unsigned int (*get_io_min)(struct se_device *);
  	unsigned int (*get_io_opt)(struct se_device *);

  	unsigned char *(*get_sense_buffer)(struct se_cmd *);

  	bool (*get_write_cache)(struct se_device *);

  	int (*init_prot)(struct se_device *);
  	int (*format_prot)(struct se_device *);
  	void (*free_prot)(struct se_device *);

  	struct configfs_attribute **tb_dev_attrib_attrs;

  	struct configfs_attribute **tb_dev_action_attrs;

  };

  struct sbc_ops {

  	sense_reason_t (*execute_rw)(struct se_cmd *cmd, struct scatterlist *,
  				     u32, enum dma_data_direction);

  	sense_reason_t (*execute_sync_cache)(struct se_cmd *cmd);
  	sense_reason_t (*execute_write_same)(struct se_cmd *cmd);

  	sense_reason_t (*execute_unmap)(struct se_cmd *cmd,
  				sector_t lba, sector_t nolb);

  };

  int	transport_backend_register(const struct target_backend_ops *);
  void	target_backend_unregister(const struct target_backend_ops *);

  void	target_complete_cmd(struct se_cmd *, u8);

  void	target_complete_cmd_with_length(struct se_cmd *, u8, int);

  void	transport_copy_sense_to_cmd(struct se_cmd *, unsigned char *);

  sense_reason_t	spc_parse_cdb(struct se_cmd *cmd, unsigned int *size);
  sense_reason_t	spc_emulate_report_luns(struct se_cmd *cmd);

  sense_reason_t	spc_emulate_inquiry_std(struct se_cmd *, unsigned char *);
  sense_reason_t	spc_emulate_evpd_83(struct se_cmd *, unsigned char *);

  sense_reason_t	sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops);

  u32	sbc_get_device_rev(struct se_device *dev);
  u32	sbc_get_device_type(struct se_device *dev);

  sector_t	sbc_get_write_same_sectors(struct se_cmd *cmd);

  void	sbc_dif_generate(struct se_cmd *);

  sense_reason_t	sbc_dif_verify(struct se_cmd *, sector_t, unsigned int,

  				     unsigned int, struct scatterlist *, int);

  void sbc_dif_copy_prot(struct se_cmd *, unsigned int, bool,
  		       struct scatterlist *, int);

  void	transport_set_vpd_proto_id(struct t10_vpd *, unsigned char *);
  int	transport_set_vpd_assoc(struct t10_vpd *, unsigned char *);
  int	transport_set_vpd_ident_type(struct t10_vpd *, unsigned char *);
  int	transport_set_vpd_ident(struct t10_vpd *, unsigned char *);

  extern struct configfs_attribute *sbc_attrib_attrs[];
  extern struct configfs_attribute *passthrough_attrib_attrs[];

  extern struct configfs_attribute *passthrough_pr_attrib_attrs[];

  /* core helpers also used by command snooping in pscsi */

  void	*transport_kmap_data_sg(struct se_cmd *);
  void	transport_kunmap_data_sg(struct se_cmd *);

  /* core helpers also used by xcopy during internal command setup */

  sense_reason_t	transport_generic_map_mem_to_cmd(struct se_cmd *,
  		struct scatterlist *, u32, struct scatterlist *, u32);

  bool	target_lun_is_rdonly(struct se_cmd *);

  sense_reason_t passthrough_parse_cdb(struct se_cmd *cmd,
  	sense_reason_t (*exec_cmd)(struct se_cmd *cmd));

  bool target_sense_desc_format(struct se_device *dev);

  sector_t target_to_linux_sector(struct se_device *dev, sector_t lb);
  bool target_configure_unmap_from_queue(struct se_dev_attrib *attrib,

  				       struct request_queue *q);

  static inline bool target_dev_configured(struct se_device *se_dev)
  {
  	return !!(se_dev->dev_flags & DF_CONFIGURED);
  }

  #endif /* TARGET_CORE_BACKEND_H */