include/scsi/scsi_dh.h

   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