2 * SCSI device handler infrastruture.
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License as published by the
6 * Free Software Foundation; either version 2 of the License, or (at your
7 * option) any later version.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18 * Copyright IBM Corporation, 2007
20 * Chandra Seetharaman <sekharan@us.ibm.com>
21 * Mike Anderson <andmike@linux.vnet.ibm.com>
24 #include <linux/slab.h>
25 #include <linux/module.h>
26 #include <scsi/scsi_dh.h>
27 #include "scsi_priv.h"
29 static DEFINE_SPINLOCK(list_lock
);
30 static LIST_HEAD(scsi_dh_list
);
32 struct scsi_dh_blist
{
38 static const struct scsi_dh_blist scsi_dh_blist
[] = {
39 {"DGC", "RAID", "emc" },
40 {"DGC", "DISK", "emc" },
41 {"DGC", "VRAID", "emc" },
43 {"COMPAQ", "MSA1000 VOLUME", "hp_sw" },
44 {"COMPAQ", "HSV110", "hp_sw" },
45 {"HP", "HSV100", "hp_sw"},
46 {"DEC", "HSG80", "hp_sw"},
48 {"IBM", "1722", "rdac", },
49 {"IBM", "1724", "rdac", },
50 {"IBM", "1726", "rdac", },
51 {"IBM", "1742", "rdac", },
52 {"IBM", "1745", "rdac", },
53 {"IBM", "1746", "rdac", },
54 {"IBM", "1813", "rdac", },
55 {"IBM", "1814", "rdac", },
56 {"IBM", "1815", "rdac", },
57 {"IBM", "1818", "rdac", },
58 {"IBM", "3526", "rdac", },
59 {"SGI", "TP9", "rdac", },
60 {"SGI", "IS", "rdac", },
61 {"STK", "OPENstorage D280", "rdac", },
62 {"STK", "FLEXLINE 380", "rdac", },
63 {"SUN", "CSM", "rdac", },
64 {"SUN", "LCSM100", "rdac", },
65 {"SUN", "STK6580_6780", "rdac", },
66 {"SUN", "SUN_6180", "rdac", },
67 {"SUN", "ArrayStorage", "rdac", },
68 {"DELL", "MD3", "rdac", },
69 {"NETAPP", "INF-01-00", "rdac", },
70 {"LSI", "INF-01-00", "rdac", },
71 {"ENGENIO", "INF-01-00", "rdac", },
76 scsi_dh_find_driver(struct scsi_device
*sdev
)
78 const struct scsi_dh_blist
*b
;
80 if (scsi_device_tpgs(sdev
))
83 for (b
= scsi_dh_blist
; b
->vendor
; b
++) {
84 if (!strncmp(sdev
->vendor
, b
->vendor
, strlen(b
->vendor
)) &&
85 !strncmp(sdev
->model
, b
->model
, strlen(b
->model
))) {
93 static struct scsi_device_handler
*__scsi_dh_lookup(const char *name
)
95 struct scsi_device_handler
*tmp
, *found
= NULL
;
97 spin_lock(&list_lock
);
98 list_for_each_entry(tmp
, &scsi_dh_list
, list
) {
99 if (!strncmp(tmp
->name
, name
, strlen(tmp
->name
))) {
104 spin_unlock(&list_lock
);
108 static struct scsi_device_handler
*scsi_dh_lookup(const char *name
)
110 struct scsi_device_handler
*dh
;
112 dh
= __scsi_dh_lookup(name
);
114 request_module("scsi_dh_%s", name
);
115 dh
= __scsi_dh_lookup(name
);
122 * scsi_dh_handler_attach - Attach a device handler to a device
123 * @sdev - SCSI device the device handler should attach to
124 * @scsi_dh - The device handler to attach
126 static int scsi_dh_handler_attach(struct scsi_device
*sdev
,
127 struct scsi_device_handler
*scsi_dh
)
131 if (!try_module_get(scsi_dh
->module
))
134 error
= scsi_dh
->attach(sdev
);
135 if (error
!= SCSI_DH_OK
) {
140 case SCSI_DH_RES_TEMP_UNAVAIL
:
143 case SCSI_DH_DEV_UNSUPP
:
152 sdev_printk(KERN_ERR
, sdev
, "%s: Attach failed (%d)\n",
153 scsi_dh
->name
, error
);
154 module_put(scsi_dh
->module
);
156 sdev
->handler
= scsi_dh
;
162 * scsi_dh_handler_detach - Detach a device handler from a device
163 * @sdev - SCSI device the device handler should be detached from
165 static void scsi_dh_handler_detach(struct scsi_device
*sdev
)
167 sdev
->handler
->detach(sdev
);
168 sdev_printk(KERN_NOTICE
, sdev
, "%s: Detached\n", sdev
->handler
->name
);
169 module_put(sdev
->handler
->module
);
172 void scsi_dh_add_device(struct scsi_device
*sdev
)
174 struct scsi_device_handler
*devinfo
= NULL
;
177 drv
= scsi_dh_find_driver(sdev
);
179 devinfo
= __scsi_dh_lookup(drv
);
181 * device_handler is optional, so ignore errors
182 * from scsi_dh_handler_attach()
185 (void)scsi_dh_handler_attach(sdev
, devinfo
);
188 void scsi_dh_release_device(struct scsi_device
*sdev
)
191 scsi_dh_handler_detach(sdev
);
195 * scsi_register_device_handler - register a device handler personality
197 * @scsi_dh - device handler to be registered.
199 * Returns 0 on success, -EBUSY if handler already registered.
201 int scsi_register_device_handler(struct scsi_device_handler
*scsi_dh
)
203 if (__scsi_dh_lookup(scsi_dh
->name
))
206 if (!scsi_dh
->attach
|| !scsi_dh
->detach
)
209 spin_lock(&list_lock
);
210 list_add(&scsi_dh
->list
, &scsi_dh_list
);
211 spin_unlock(&list_lock
);
213 printk(KERN_INFO
"%s: device handler registered\n", scsi_dh
->name
);
217 EXPORT_SYMBOL_GPL(scsi_register_device_handler
);
220 * scsi_unregister_device_handler - register a device handler personality
222 * @scsi_dh - device handler to be unregistered.
224 * Returns 0 on success, -ENODEV if handler not registered.
226 int scsi_unregister_device_handler(struct scsi_device_handler
*scsi_dh
)
228 if (!__scsi_dh_lookup(scsi_dh
->name
))
231 spin_lock(&list_lock
);
232 list_del(&scsi_dh
->list
);
233 spin_unlock(&list_lock
);
234 printk(KERN_INFO
"%s: device handler unregistered\n", scsi_dh
->name
);
238 EXPORT_SYMBOL_GPL(scsi_unregister_device_handler
);
241 * scsi_dh_activate - activate the path associated with the scsi_device
242 * corresponding to the given request queue.
243 * Returns immediately without waiting for activation to be completed.
244 * @q - Request queue that is associated with the scsi_device to be
246 * @fn - Function to be called upon completion of the activation.
247 * Function fn is called with data (below) and the error code.
248 * Function fn may be called from the same calling context. So,
249 * do not hold the lock in the caller which may be needed in fn.
250 * @data - data passed to the function fn upon completion.
253 int scsi_dh_activate(struct request_queue
*q
, activate_complete fn
, void *data
)
255 struct scsi_device
*sdev
;
256 int err
= SCSI_DH_NOSYS
;
258 sdev
= scsi_device_from_queue(q
);
267 err
= SCSI_DH_NOTCONN
;
268 if (sdev
->sdev_state
== SDEV_CANCEL
||
269 sdev
->sdev_state
== SDEV_DEL
)
272 err
= SCSI_DH_DEV_OFFLINED
;
273 if (sdev
->sdev_state
== SDEV_OFFLINE
)
276 if (sdev
->handler
->activate
)
277 err
= sdev
->handler
->activate(sdev
, fn
, data
);
280 put_device(&sdev
->sdev_gendev
);
288 EXPORT_SYMBOL_GPL(scsi_dh_activate
);
291 * scsi_dh_set_params - set the parameters for the device as per the
292 * string specified in params.
293 * @q - Request queue that is associated with the scsi_device for
294 * which the parameters to be set.
295 * @params - parameters in the following format
296 * "no_of_params\0param1\0param2\0param3\0...\0"
297 * for example, string for 2 parameters with value 10 and 21
298 * is specified as "2\010\021\0".
300 int scsi_dh_set_params(struct request_queue
*q
, const char *params
)
302 struct scsi_device
*sdev
;
303 int err
= -SCSI_DH_NOSYS
;
305 sdev
= scsi_device_from_queue(q
);
309 if (sdev
->handler
&& sdev
->handler
->set_params
)
310 err
= sdev
->handler
->set_params(sdev
, params
);
311 put_device(&sdev
->sdev_gendev
);
314 EXPORT_SYMBOL_GPL(scsi_dh_set_params
);
317 * scsi_dh_attach - Attach device handler
318 * @q - Request queue that is associated with the scsi_device
319 * the handler should be attached to
320 * @name - name of the handler to attach
322 int scsi_dh_attach(struct request_queue
*q
, const char *name
)
324 struct scsi_device
*sdev
;
325 struct scsi_device_handler
*scsi_dh
;
328 sdev
= scsi_device_from_queue(q
);
332 scsi_dh
= scsi_dh_lookup(name
);
339 if (sdev
->handler
!= scsi_dh
)
344 err
= scsi_dh_handler_attach(sdev
, scsi_dh
);
347 put_device(&sdev
->sdev_gendev
);
350 EXPORT_SYMBOL_GPL(scsi_dh_attach
);
353 * scsi_dh_attached_handler_name - Get attached device handler's name
354 * @q - Request queue that is associated with the scsi_device
355 * that may have a device handler attached
356 * @gfp - the GFP mask used in the kmalloc() call when allocating memory
358 * Returns name of attached handler, NULL if no handler is attached.
359 * Caller must take care to free the returned string.
361 const char *scsi_dh_attached_handler_name(struct request_queue
*q
, gfp_t gfp
)
363 struct scsi_device
*sdev
;
364 const char *handler_name
= NULL
;
366 sdev
= scsi_device_from_queue(q
);
371 handler_name
= kstrdup(sdev
->handler
->name
, gfp
);
372 put_device(&sdev
->sdev_gendev
);
375 EXPORT_SYMBOL_GPL(scsi_dh_attached_handler_name
);