xref: /openbmc/linux/include/scsi/scsi_dh.h (revision 9cfc5c90)
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_NOSYS,
56 	SCSI_DH_DRIVER_MAX,
57 };
58 
59 typedef void (*activate_complete)(void *, int);
60 struct scsi_device_handler {
61 	/* Used by the infrastructure */
62 	struct list_head list; /* list of scsi_device_handlers */
63 
64 	/* Filled by the hardware handler */
65 	struct module *module;
66 	const char *name;
67 	int (*check_sense)(struct scsi_device *, struct scsi_sense_hdr *);
68 	int (*attach)(struct scsi_device *);
69 	void (*detach)(struct scsi_device *);
70 	int (*activate)(struct scsi_device *, activate_complete, void *);
71 	int (*prep_fn)(struct scsi_device *, struct request *);
72 	int (*set_params)(struct scsi_device *, const char *);
73 };
74 
75 #ifdef CONFIG_SCSI_DH
76 extern int scsi_dh_activate(struct request_queue *, activate_complete, void *);
77 extern int scsi_dh_attach(struct request_queue *, const char *);
78 extern const char *scsi_dh_attached_handler_name(struct request_queue *, gfp_t);
79 extern int scsi_dh_set_params(struct request_queue *, const char *);
80 #else
81 static inline int scsi_dh_activate(struct request_queue *req,
82 					activate_complete fn, void *data)
83 {
84 	fn(data, 0);
85 	return 0;
86 }
87 static inline int scsi_dh_attach(struct request_queue *req, const char *name)
88 {
89 	return SCSI_DH_NOSYS;
90 }
91 static inline const char *scsi_dh_attached_handler_name(struct request_queue *q,
92 							gfp_t gfp)
93 {
94 	return NULL;
95 }
96 static inline int scsi_dh_set_params(struct request_queue *req, const char *params)
97 {
98 	return -SCSI_DH_NOSYS;
99 }
100 #endif
101