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 
15 enum {
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 
47 typedef void (*activate_complete)(void *, int);
48 struct 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
66 extern int scsi_dh_activate(struct request_queue *, activate_complete, void *);
67 extern int scsi_dh_attach(struct request_queue *, const char *);
68 extern const char *scsi_dh_attached_handler_name(struct request_queue *, gfp_t);
69 extern int scsi_dh_set_params(struct request_queue *, const char *);
70 #else
scsi_dh_activate(struct request_queue * req,activate_complete fn,void * data)71 static inline int scsi_dh_activate(struct request_queue *req,
72 					activate_complete fn, void *data)
73 {
74 	fn(data, 0);
75 	return 0;
76 }
scsi_dh_attach(struct request_queue * req,const char * name)77 static inline int scsi_dh_attach(struct request_queue *req, const char *name)
78 {
79 	return SCSI_DH_NOSYS;
80 }
scsi_dh_attached_handler_name(struct request_queue * q,gfp_t gfp)81 static inline const char *scsi_dh_attached_handler_name(struct request_queue *q,
82 							gfp_t gfp)
83 {
84 	return NULL;
85 }
scsi_dh_set_params(struct request_queue * req,const char * params)86 static inline int scsi_dh_set_params(struct request_queue *req, const char *params)
87 {
88 	return -SCSI_DH_NOSYS;
89 }
90 #endif
91