xref: /linux/include/target/target_core_fabric.h (revision 1b78070aaef63512688aebfbc82365ef9d6660f1)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef TARGET_CORE_FABRIC_H
3 #define TARGET_CORE_FABRIC_H
4 
5 #include <linux/configfs.h>
6 #include <linux/types.h>
7 #include <target/target_core_base.h>
8 
9 struct target_core_fabric_ops {
10 	struct module *module;
11 	/*
12 	 * XXX: Special case for iscsi/iSCSI...
13 	 * If non-null, fabric_alias is used for matching target/$fabric
14 	 * ConfigFS paths. If null, fabric_name is used for this (see below).
15 	 */
16 	const char *fabric_alias;
17 	/*
18 	 * fabric_name is used for matching target/$fabric ConfigFS paths
19 	 * without a fabric_alias (see above). It's also used for the ALUA state
20 	 * path and is stored on disk with PR state.
21 	 */
22 	const char *fabric_name;
23 	size_t node_acl_size;
24 	/*
25 	 * Limits number of scatterlist entries per SCF_SCSI_DATA_CDB payload.
26 	 * Setting this value tells target-core to enforce this limit, and
27 	 * report as INQUIRY EVPD=b0 MAXIMUM TRANSFER LENGTH.
28 	 *
29 	 * target-core will currently reset se_cmd->data_length to this
30 	 * maximum size, and set UNDERFLOW residual count if length exceeds
31 	 * this limit.
32 	 *
33 	 * XXX: Not all initiator hosts honor this block-limit EVPD
34 	 * XXX: Currently assumes single PAGE_SIZE per scatterlist entry
35 	 */
36 	u32 max_data_sg_nents;
37 	char *(*tpg_get_wwn)(struct se_portal_group *);
38 	u16 (*tpg_get_tag)(struct se_portal_group *);
39 	u32 (*tpg_get_default_depth)(struct se_portal_group *);
40 	int (*tpg_check_demo_mode)(struct se_portal_group *);
41 	int (*tpg_check_demo_mode_cache)(struct se_portal_group *);
42 	int (*tpg_check_demo_mode_write_protect)(struct se_portal_group *);
43 	int (*tpg_check_prod_mode_write_protect)(struct se_portal_group *);
44 	/*
45 	 * Optionally used by fabrics to allow demo-mode login, but not
46 	 * expose any TPG LUNs, and return 'not connected' in standard
47 	 * inquiry response
48 	 */
49 	int (*tpg_check_demo_mode_login_only)(struct se_portal_group *);
50 	/*
51 	 * Optionally used as a configfs tunable to determine when
52 	 * target-core should signal the PROTECT=1 feature bit for
53 	 * backends that don't support T10-PI, so that either fabric
54 	 * HW offload or target-core emulation performs the associated
55 	 * WRITE_STRIP and READ_INSERT operations.
56 	 */
57 	int (*tpg_check_prot_fabric_only)(struct se_portal_group *);
58 	u32 (*tpg_get_inst_index)(struct se_portal_group *);
59 	/*
60 	 * Optional to release struct se_cmd and fabric dependent allocated
61 	 * I/O descriptor after command execution has finished.
62 	 *
63 	 * Returning 1 will signal a descriptor has been released.
64 	 * Returning 0 will signal a descriptor has not been released.
65 	 */
66 	int (*check_stop_free)(struct se_cmd *);
67 	void (*release_cmd)(struct se_cmd *);
68 	void (*close_session)(struct se_session *);
69 	u32 (*sess_get_index)(struct se_session *);
70 	/*
71 	 * Used only for SCSI fabrics that contain multi-value TransportIDs
72 	 * (like iSCSI).  All other SCSI fabrics should set this to NULL.
73 	 */
74 	u32 (*sess_get_initiator_sid)(struct se_session *,
75 				      unsigned char *, u32);
76 	int (*write_pending)(struct se_cmd *);
77 	void (*set_default_node_attributes)(struct se_node_acl *);
78 	int (*get_cmd_state)(struct se_cmd *);
79 	int (*queue_data_in)(struct se_cmd *);
80 	int (*queue_status)(struct se_cmd *);
81 	void (*queue_tm_rsp)(struct se_cmd *);
82 	void (*aborted_task)(struct se_cmd *);
83 	/*
84 	 * fabric module calls for target_core_fabric_configfs.c
85 	 */
86 	struct se_wwn *(*fabric_make_wwn)(struct target_fabric_configfs *,
87 				struct config_group *, const char *);
88 	void (*fabric_drop_wwn)(struct se_wwn *);
89 	void (*add_wwn_groups)(struct se_wwn *);
90 	struct se_portal_group *(*fabric_make_tpg)(struct se_wwn *,
91 						   const char *);
92 	int (*fabric_enable_tpg)(struct se_portal_group *se_tpg, bool enable);
93 	void (*fabric_drop_tpg)(struct se_portal_group *);
94 	int (*fabric_post_link)(struct se_portal_group *,
95 				struct se_lun *);
96 	void (*fabric_pre_unlink)(struct se_portal_group *,
97 				struct se_lun *);
98 	void (*fabric_post_unlink)(struct se_portal_group *se_tpg,
99 				   struct se_lun *lun);
100 	struct se_tpg_np *(*fabric_make_np)(struct se_portal_group *,
101 				struct config_group *, const char *);
102 	void (*fabric_drop_np)(struct se_tpg_np *);
103 	int (*fabric_init_nodeacl)(struct se_node_acl *, const char *);
104 
105 	struct configfs_attribute **tfc_discovery_attrs;
106 	struct configfs_attribute **tfc_wwn_attrs;
107 	struct configfs_attribute **tfc_tpg_base_attrs;
108 	struct configfs_attribute **tfc_tpg_np_base_attrs;
109 	struct configfs_attribute **tfc_tpg_attrib_attrs;
110 	struct configfs_attribute **tfc_tpg_auth_attrs;
111 	struct configfs_attribute **tfc_tpg_param_attrs;
112 	struct configfs_attribute **tfc_tpg_nacl_base_attrs;
113 	struct configfs_attribute **tfc_tpg_nacl_attrib_attrs;
114 	struct configfs_attribute **tfc_tpg_nacl_auth_attrs;
115 	struct configfs_attribute **tfc_tpg_nacl_param_attrs;
116 
117 	/*
118 	 * Set this member variable if the SCSI transport protocol
119 	 * (e.g. iSCSI) requires that the Data-Out buffer is transferred in
120 	 * its entirety before a command is aborted.
121 	 */
122 	unsigned int write_pending_must_be_called:1;
123 	/*
124 	 * Set this if the driver does not require calling queue_data_in
125 	 * queue_status and check_stop_free from a worker thread when
126 	 * completing successful commands.
127 	 */
128 	unsigned int direct_compl_supp:1;
129 	/*
130 	 * Set this if the driver supports submitting commands to the backend
131 	 * from target_submit/target_submit_cmd.
132 	 */
133 	unsigned int direct_submit_supp:1;
134 	/* Set this to a target_submit_type value. */
135 	u8 default_submit_type;
136 	/* Set this to the target_compl_type value. */
137 	u8 default_compl_type;
138 };
139 
140 int target_register_template(const struct target_core_fabric_ops *fo);
141 void target_unregister_template(const struct target_core_fabric_ops *fo);
142 
143 int target_depend_item(struct config_item *item);
144 void target_undepend_item(struct config_item *item);
145 
146 struct se_session *target_setup_session(struct se_portal_group *,
147 		unsigned int, unsigned int, enum target_prot_op prot_op,
148 		const char *, void *,
149 		int (*callback)(struct se_portal_group *,
150 				struct se_session *, void *));
151 void target_remove_session(struct se_session *);
152 
153 void target_stop_cmd_counter(struct target_cmd_counter *cmd_cnt);
154 void target_wait_for_cmds(struct target_cmd_counter *cmd_cnt);
155 struct target_cmd_counter *target_alloc_cmd_counter(void);
156 void target_free_cmd_counter(struct target_cmd_counter *cmd_cnt);
157 
158 void transport_init_session(struct se_session *se_sess);
159 struct se_session *transport_alloc_session(enum target_prot_op);
160 int transport_alloc_session_tags(struct se_session *, unsigned int,
161 		unsigned int);
162 void	__transport_register_session(struct se_portal_group *,
163 		struct se_node_acl *, struct se_session *, void *);
164 void	transport_register_session(struct se_portal_group *,
165 		struct se_node_acl *, struct se_session *, void *);
166 ssize_t	target_show_dynamic_sessions(struct se_portal_group *, char *);
167 void	transport_free_session(struct se_session *);
168 void	target_spc2_release(struct se_node_acl *nacl);
169 void	target_put_nacl(struct se_node_acl *);
170 void	transport_deregister_session_configfs(struct se_session *);
171 void	transport_deregister_session(struct se_session *);
172 
173 
174 void	__target_init_cmd(struct se_cmd *cmd,
175 		const struct target_core_fabric_ops *tfo,
176 		struct se_session *sess, u32 data_length, int data_direction,
177 		int task_attr, unsigned char *sense_buffer, u64 unpacked_lun,
178 		struct target_cmd_counter *cmd_cnt);
179 int	target_init_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
180 		unsigned char *sense, u64 unpacked_lun, u32 data_length,
181 		int task_attr, int data_dir, int flags);
182 int	target_submit_prep(struct se_cmd *se_cmd, unsigned char *cdb,
183 		struct scatterlist *sgl, u32 sgl_count,
184 		struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
185 		struct scatterlist *sgl_prot, u32 sgl_prot_count, gfp_t gfp);
186 int	target_submit(struct se_cmd *se_cmd);
187 sense_reason_t transport_lookup_cmd_lun(struct se_cmd *);
188 sense_reason_t target_cmd_init_cdb(struct se_cmd *se_cmd, unsigned char *cdb,
189 				   gfp_t gfp);
190 sense_reason_t target_cmd_parse_cdb(struct se_cmd *);
191 void	target_submit_cmd(struct se_cmd *, struct se_session *, unsigned char *,
192 		unsigned char *, u64, u32, int, int, int);
193 
194 int	target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
195 		unsigned char *sense, u64 unpacked_lun,
196 		void *fabric_tmr_ptr, unsigned char tm_type,
197 		gfp_t, u64, int);
198 sense_reason_t	transport_generic_new_cmd(struct se_cmd *);
199 
200 void	target_put_cmd_and_wait(struct se_cmd *cmd);
201 void	target_execute_cmd(struct se_cmd *cmd);
202 
203 int	transport_generic_free_cmd(struct se_cmd *, int);
204 
205 bool	transport_wait_for_tasks(struct se_cmd *);
206 int	transport_send_check_condition_and_sense(struct se_cmd *,
207 		sense_reason_t, int);
208 int	target_send_busy(struct se_cmd *cmd);
209 int	target_get_sess_cmd(struct se_cmd *, bool);
210 int	target_put_sess_cmd(struct se_cmd *);
211 void	target_stop_session(struct se_session *se_sess);
212 void	target_wait_for_sess_cmds(struct se_session *);
213 void	target_show_cmd(const char *pfx, struct se_cmd *cmd);
214 
215 int	core_tmr_alloc_req(struct se_cmd *, void *, u8, gfp_t);
216 void	core_tmr_release_req(struct se_tmr_req *);
217 int	transport_generic_handle_tmr(struct se_cmd *);
218 void	transport_generic_request_failure(struct se_cmd *, sense_reason_t);
219 int	transport_lookup_tmr_lun(struct se_cmd *);
220 void	core_allocate_nexus_loss_ua(struct se_node_acl *acl);
221 
222 struct se_node_acl *core_tpg_get_initiator_node_acl(struct se_portal_group *tpg,
223 		unsigned char *);
224 bool	target_tpg_has_node_acl(struct se_portal_group *tpg,
225 		const char *);
226 struct se_node_acl *core_tpg_check_initiator_node_acl(struct se_portal_group *,
227 		unsigned char *);
228 int	core_tpg_set_initiator_node_queue_depth(struct se_node_acl *, u32);
229 int	core_tpg_set_initiator_node_tag(struct se_portal_group *,
230 		struct se_node_acl *, const char *);
231 int	core_tpg_register(struct se_wwn *, struct se_portal_group *, int);
232 int	core_tpg_deregister(struct se_portal_group *);
233 
234 int	target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents,
235 		u32 length, bool zero_page, bool chainable);
236 void	target_free_sgl(struct scatterlist *sgl, int nents);
237 
238 /*
239  * The LIO target core uses DMA_TO_DEVICE to mean that data is going
240  * to the target (eg handling a WRITE) and DMA_FROM_DEVICE to mean
241  * that data is coming from the target (eg handling a READ).  However,
242  * this is just the opposite of what we have to tell the DMA mapping
243  * layer -- eg when handling a READ, the HBA will have to DMA the data
244  * out of memory so it can send it to the initiator, which means we
245  * need to use DMA_TO_DEVICE when we map the data.
246  */
247 static inline enum dma_data_direction
248 target_reverse_dma_direction(struct se_cmd *se_cmd)
249 {
250 	if (se_cmd->se_cmd_flags & SCF_BIDI)
251 		return DMA_BIDIRECTIONAL;
252 
253 	switch (se_cmd->data_direction) {
254 	case DMA_TO_DEVICE:
255 		return DMA_FROM_DEVICE;
256 	case DMA_FROM_DEVICE:
257 		return DMA_TO_DEVICE;
258 	case DMA_NONE:
259 	default:
260 		return DMA_NONE;
261 	}
262 }
263 
264 #endif /* TARGET_CORE_FABRICH */
265