xref: /openbmc/linux/include/scsi/scsi_dh.h (revision f9a82c48)
1 /*
2  * Header file for SCSI device handler infrastruture.
3  *
4  * Modified version of patches posted by Mike Christie <michaelc@cs.wisc.edu>
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License as published by the
8  * Free Software Foundation; either version 2 of the License, or (at your
9  * option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful, but
12  * WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License along
17  * with this program; if not, write to the Free Software Foundation, Inc.,
18  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19  *
20  * Copyright IBM Corporation, 2007
21  *      Authors:
22  *               Chandra Seetharaman <sekharan@us.ibm.com>
23  *               Mike Anderson <andmike@linux.vnet.ibm.com>
24  */
25 
26 #include <scsi/scsi_device.h>
27 
28 enum {
29 	SCSI_DH_OK = 0,
30 	/*
31 	 * device errors
32 	 */
33 	SCSI_DH_DEV_FAILED,	/* generic device error */
34 	SCSI_DH_DEV_TEMP_BUSY,
35 	SCSI_DH_DEV_UNSUPP,	/* device handler not supported */
36 	SCSI_DH_DEVICE_MAX,	/* max device blkerr definition */
37 
38 	/*
39 	 * transport errors
40 	 */
41 	SCSI_DH_NOTCONN = SCSI_DH_DEVICE_MAX + 1,
42 	SCSI_DH_CONN_FAILURE,
43 	SCSI_DH_TRANSPORT_MAX,	/* max transport blkerr definition */
44 
45 	/*
46 	 * driver and generic errors
47 	 */
48 	SCSI_DH_IO = SCSI_DH_TRANSPORT_MAX + 1,	/* generic error */
49 	SCSI_DH_INVALID_IO,
50 	SCSI_DH_RETRY,		/* retry the req, but not immediately */
51 	SCSI_DH_IMM_RETRY,	/* immediately retry the req */
52 	SCSI_DH_TIMED_OUT,
53 	SCSI_DH_RES_TEMP_UNAVAIL,
54 	SCSI_DH_DEV_OFFLINED,
55 	SCSI_DH_NOMEM,
56 	SCSI_DH_NOSYS,
57 	SCSI_DH_DRIVER_MAX,
58 };
59 
60 typedef void (*activate_complete)(void *, int);
61 struct scsi_device_handler {
62 	/* Used by the infrastructure */
63 	struct list_head list; /* list of scsi_device_handlers */
64 
65 	/* Filled by the hardware handler */
66 	struct module *module;
67 	const char *name;
68 	int (*check_sense)(struct scsi_device *, struct scsi_sense_hdr *);
69 	int (*attach)(struct scsi_device *);
70 	void (*detach)(struct scsi_device *);
71 	int (*activate)(struct scsi_device *, activate_complete, void *);
72 	blk_status_t (*prep_fn)(struct scsi_device *, struct request *);
73 	int (*set_params)(struct scsi_device *, const char *);
74 	void (*rescan)(struct scsi_device *);
75 };
76 
77 #ifdef CONFIG_SCSI_DH
78 extern int scsi_dh_activate(struct request_queue *, activate_complete, void *);
79 extern int scsi_dh_attach(struct request_queue *, const char *);
80 extern const char *scsi_dh_attached_handler_name(struct request_queue *, gfp_t);
81 extern int scsi_dh_set_params(struct request_queue *, const char *);
82 #else
83 static inline int scsi_dh_activate(struct request_queue *req,
84 					activate_complete fn, void *data)
85 {
86 	fn(data, 0);
87 	return 0;
88 }
89 static inline int scsi_dh_attach(struct request_queue *req, const char *name)
90 {
91 	return SCSI_DH_NOSYS;
92 }
93 static inline const char *scsi_dh_attached_handler_name(struct request_queue *q,
94 							gfp_t gfp)
95 {
96 	return NULL;
97 }
98 static inline int scsi_dh_set_params(struct request_queue *req, const char *params)
99 {
100 	return -SCSI_DH_NOSYS;
101 }
102 #endif
103