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
28enum {
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
59typedef void (*activate_complete)(void *, int);
60struct 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
76extern int scsi_dh_activate(struct request_queue *, activate_complete, void *);
77extern int scsi_dh_attach(struct request_queue *, const char *);
78extern const char *scsi_dh_attached_handler_name(struct request_queue *, gfp_t);
79extern int scsi_dh_set_params(struct request_queue *, const char *);
80#else
81static inline int scsi_dh_activate(struct request_queue *req,
82					activate_complete fn, void *data)
83{
84	fn(data, 0);
85	return 0;
86}
87static inline int scsi_dh_attach(struct request_queue *req, const char *name)
88{
89	return SCSI_DH_NOSYS;
90}
91static inline const char *scsi_dh_attached_handler_name(struct request_queue *q,
92							gfp_t gfp)
93{
94	return NULL;
95}
96static inline int scsi_dh_set_params(struct request_queue *req, const char *params)
97{
98	return -SCSI_DH_NOSYS;
99}
100#endif
101