1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * Header file for SCSI device handler infrastructure.
4 *
5 * Modified version of patches posted by Mike Christie <michaelc@cs.wisc.edu>
6 *
7 * Copyright IBM Corporation, 2007
8 *      Authors:
9 *               Chandra Seetharaman <sekharan@us.ibm.com>
10 *               Mike Anderson <andmike@linux.vnet.ibm.com>
11 */
12
13#include <scsi/scsi_device.h>
14
15enum {
16	SCSI_DH_OK = 0,
17	/*
18	 * device errors
19	 */
20	SCSI_DH_DEV_FAILED,	/* generic device error */
21	SCSI_DH_DEV_TEMP_BUSY,
22	SCSI_DH_DEV_UNSUPP,	/* device handler not supported */
23	SCSI_DH_DEVICE_MAX,	/* max device blkerr definition */
24
25	/*
26	 * transport errors
27	 */
28	SCSI_DH_NOTCONN = SCSI_DH_DEVICE_MAX + 1,
29	SCSI_DH_CONN_FAILURE,
30	SCSI_DH_TRANSPORT_MAX,	/* max transport blkerr definition */
31
32	/*
33	 * driver and generic errors
34	 */
35	SCSI_DH_IO = SCSI_DH_TRANSPORT_MAX + 1,	/* generic error */
36	SCSI_DH_INVALID_IO,
37	SCSI_DH_RETRY,		/* retry the req, but not immediately */
38	SCSI_DH_IMM_RETRY,	/* immediately retry the req */
39	SCSI_DH_TIMED_OUT,
40	SCSI_DH_RES_TEMP_UNAVAIL,
41	SCSI_DH_DEV_OFFLINED,
42	SCSI_DH_NOMEM,
43	SCSI_DH_NOSYS,
44	SCSI_DH_DRIVER_MAX,
45};
46
47typedef void (*activate_complete)(void *, int);
48struct scsi_device_handler {
49	/* Used by the infrastructure */
50	struct list_head list; /* list of scsi_device_handlers */
51
52	/* Filled by the hardware handler */
53	struct module *module;
54	const char *name;
55	enum scsi_disposition (*check_sense)(struct scsi_device *,
56					     struct scsi_sense_hdr *);
57	int (*attach)(struct scsi_device *);
58	void (*detach)(struct scsi_device *);
59	int (*activate)(struct scsi_device *, activate_complete, void *);
60	blk_status_t (*prep_fn)(struct scsi_device *, struct request *);
61	int (*set_params)(struct scsi_device *, const char *);
62	void (*rescan)(struct scsi_device *);
63};
64
65#ifdef CONFIG_SCSI_DH
66extern int scsi_dh_activate(struct request_queue *, activate_complete, void *);
67extern int scsi_dh_attach(struct request_queue *, const char *);
68extern const char *scsi_dh_attached_handler_name(struct request_queue *, gfp_t);
69extern int scsi_dh_set_params(struct request_queue *, const char *);
70#else
71static inline int scsi_dh_activate(struct request_queue *req,
72					activate_complete fn, void *data)
73{
74	fn(data, 0);
75	return 0;
76}
77static inline int scsi_dh_attach(struct request_queue *req, const char *name)
78{
79	return SCSI_DH_NOSYS;
80}
81static inline const char *scsi_dh_attached_handler_name(struct request_queue *q,
82							gfp_t gfp)
83{
84	return NULL;
85}
86static inline int scsi_dh_set_params(struct request_queue *req, const char *params)
87{
88	return -SCSI_DH_NOSYS;
89}
90#endif
91