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", "clariion" },
40 {"DGC", "DISK", "clariion" },
41 {"DGC", "VRAID", "clariion" },
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 {"IBM", "3542", "rdac", },
60 {"IBM", "3552", "rdac", },
61 {"SGI", "TP9300", "rdac", },
62 {"SGI", "TP9400", "rdac", },
63 {"SGI", "TP9500", "rdac", },
64 {"SGI", "TP9700", "rdac", },
65 {"SGI", "IS", "rdac", },
66 {"STK", "OPENstorage", "rdac", },
67 {"STK", "FLEXLINE 380", "rdac", },
68 {"STK", "BladeCtlr", "rdac", },
69 {"SUN", "CSM", "rdac", },
70 {"SUN", "LCSM100", "rdac", },
71 {"SUN", "STK6580_6780", "rdac", },
72 {"SUN", "SUN_6180", "rdac", },
73 {"SUN", "ArrayStorage", "rdac", },
74 {"DELL", "MD3", "rdac", },
75 {"NETAPP", "INF-01-00", "rdac", },
76 {"LSI", "INF-01-00", "rdac", },
77 {"ENGENIO", "INF-01-00", "rdac", },
82 scsi_dh_find_driver(struct scsi_device *sdev)
84 const struct scsi_dh_blist *b;
86 if (scsi_device_tpgs(sdev))
89 for (b = scsi_dh_blist; b->vendor; b++) {
90 if (!strncmp(sdev->vendor, b->vendor, strlen(b->vendor)) &&
91 !strncmp(sdev->model, b->model, strlen(b->model))) {
99 static struct scsi_device_handler *__scsi_dh_lookup(const char *name)
101 struct scsi_device_handler *tmp, *found = NULL;
103 spin_lock(&list_lock);
104 list_for_each_entry(tmp, &scsi_dh_list, list) {
105 if (!strncmp(tmp->name, name, strlen(tmp->name))) {
110 spin_unlock(&list_lock);
114 static struct scsi_device_handler *scsi_dh_lookup(const char *name)
116 struct scsi_device_handler *dh;
118 dh = __scsi_dh_lookup(name);
120 request_module("scsi_dh_%s", name);
121 dh = __scsi_dh_lookup(name);
128 * scsi_dh_handler_attach - Attach a device handler to a device
129 * @sdev - SCSI device the device handler should attach to
130 * @scsi_dh - The device handler to attach
132 static int scsi_dh_handler_attach(struct scsi_device *sdev,
133 struct scsi_device_handler *scsi_dh)
137 if (!try_module_get(scsi_dh->module))
140 error = scsi_dh->attach(sdev);
142 sdev_printk(KERN_ERR, sdev, "%s: Attach failed (%d)\n",
143 scsi_dh->name, error);
144 module_put(scsi_dh->module);
146 sdev->handler = scsi_dh;
152 * scsi_dh_handler_detach - Detach a device handler from a device
153 * @sdev - SCSI device the device handler should be detached from
155 static void scsi_dh_handler_detach(struct scsi_device *sdev)
157 sdev->handler->detach(sdev);
158 sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", sdev->handler->name);
159 module_put(sdev->handler->module);
163 * Functions for sysfs attribute 'dh_state'
166 store_dh_state(struct device *dev, struct device_attribute *attr,
167 const char *buf, size_t count)
169 struct scsi_device *sdev = to_scsi_device(dev);
170 struct scsi_device_handler *scsi_dh;
173 if (sdev->sdev_state == SDEV_CANCEL ||
174 sdev->sdev_state == SDEV_DEL)
177 if (!sdev->handler) {
179 * Attach to a device handler
181 scsi_dh = scsi_dh_lookup(buf);
184 err = scsi_dh_handler_attach(sdev, scsi_dh);
186 if (!strncmp(buf, "detach", 6)) {
188 * Detach from a device handler
190 sdev_printk(KERN_WARNING, sdev,
191 "can't detach handler %s.\n",
192 sdev->handler->name);
194 } else if (!strncmp(buf, "activate", 8)) {
196 * Activate a device handler
198 if (sdev->handler->activate)
199 err = sdev->handler->activate(sdev, NULL, NULL);
205 return err<0?err:count;
209 show_dh_state(struct device *dev, struct device_attribute *attr, char *buf)
211 struct scsi_device *sdev = to_scsi_device(dev);
214 return snprintf(buf, 20, "detached\n");
216 return snprintf(buf, 20, "%s\n", sdev->handler->name);
219 static struct device_attribute scsi_dh_state_attr =
220 __ATTR(dh_state, S_IRUGO | S_IWUSR, show_dh_state,
223 int scsi_dh_add_device(struct scsi_device *sdev)
225 struct scsi_device_handler *devinfo = NULL;
229 err = device_create_file(&sdev->sdev_gendev, &scsi_dh_state_attr);
233 drv = scsi_dh_find_driver(sdev);
235 devinfo = __scsi_dh_lookup(drv);
237 err = scsi_dh_handler_attach(sdev, devinfo);
241 void scsi_dh_release_device(struct scsi_device *sdev)
244 scsi_dh_handler_detach(sdev);
247 void scsi_dh_remove_device(struct scsi_device *sdev)
249 device_remove_file(&sdev->sdev_gendev, &scsi_dh_state_attr);
253 * scsi_register_device_handler - register a device handler personality
255 * @scsi_dh - device handler to be registered.
257 * Returns 0 on success, -EBUSY if handler already registered.
259 int scsi_register_device_handler(struct scsi_device_handler *scsi_dh)
261 if (__scsi_dh_lookup(scsi_dh->name))
264 if (!scsi_dh->attach || !scsi_dh->detach)
267 spin_lock(&list_lock);
268 list_add(&scsi_dh->list, &scsi_dh_list);
269 spin_unlock(&list_lock);
271 printk(KERN_INFO "%s: device handler registered\n", scsi_dh->name);
275 EXPORT_SYMBOL_GPL(scsi_register_device_handler);
278 * scsi_unregister_device_handler - register a device handler personality
280 * @scsi_dh - device handler to be unregistered.
282 * Returns 0 on success, -ENODEV if handler not registered.
284 int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh)
286 if (!__scsi_dh_lookup(scsi_dh->name))
289 spin_lock(&list_lock);
290 list_del(&scsi_dh->list);
291 spin_unlock(&list_lock);
292 printk(KERN_INFO "%s: device handler unregistered\n", scsi_dh->name);
296 EXPORT_SYMBOL_GPL(scsi_unregister_device_handler);
299 * scsi_dh_activate - activate the path associated with the scsi_device
300 * corresponding to the given request queue.
301 * Returns immediately without waiting for activation to be completed.
302 * @q - Request queue that is associated with the scsi_device to be
304 * @fn - Function to be called upon completion of the activation.
305 * Function fn is called with data (below) and the error code.
306 * Function fn may be called from the same calling context. So,
307 * do not hold the lock in the caller which may be needed in fn.
308 * @data - data passed to the function fn upon completion.
311 int scsi_dh_activate(struct request_queue *q, activate_complete fn, void *data)
313 struct scsi_device *sdev;
314 int err = SCSI_DH_NOSYS;
316 sdev = scsi_device_from_queue(q);
325 err = SCSI_DH_NOTCONN;
326 if (sdev->sdev_state == SDEV_CANCEL ||
327 sdev->sdev_state == SDEV_DEL)
330 err = SCSI_DH_DEV_OFFLINED;
331 if (sdev->sdev_state == SDEV_OFFLINE)
334 if (sdev->handler->activate)
335 err = sdev->handler->activate(sdev, fn, data);
338 put_device(&sdev->sdev_gendev);
346 EXPORT_SYMBOL_GPL(scsi_dh_activate);
349 * scsi_dh_set_params - set the parameters for the device as per the
350 * string specified in params.
351 * @q - Request queue that is associated with the scsi_device for
352 * which the parameters to be set.
353 * @params - parameters in the following format
354 * "no_of_params\0param1\0param2\0param3\0...\0"
355 * for example, string for 2 parameters with value 10 and 21
356 * is specified as "2\010\021\0".
358 int scsi_dh_set_params(struct request_queue *q, const char *params)
360 struct scsi_device *sdev;
361 int err = -SCSI_DH_NOSYS;
363 sdev = scsi_device_from_queue(q);
367 if (sdev->handler && sdev->handler->set_params)
368 err = sdev->handler->set_params(sdev, params);
369 put_device(&sdev->sdev_gendev);
372 EXPORT_SYMBOL_GPL(scsi_dh_set_params);
375 * scsi_dh_attach - Attach device handler
376 * @q - Request queue that is associated with the scsi_device
377 * the handler should be attached to
378 * @name - name of the handler to attach
380 int scsi_dh_attach(struct request_queue *q, const char *name)
382 struct scsi_device *sdev;
383 struct scsi_device_handler *scsi_dh;
386 sdev = scsi_device_from_queue(q);
390 scsi_dh = scsi_dh_lookup(name);
397 if (sdev->handler != scsi_dh)
402 err = scsi_dh_handler_attach(sdev, scsi_dh);
405 put_device(&sdev->sdev_gendev);
408 EXPORT_SYMBOL_GPL(scsi_dh_attach);
411 * scsi_dh_attached_handler_name - Get attached device handler's name
412 * @q - Request queue that is associated with the scsi_device
413 * that may have a device handler attached
414 * @gfp - the GFP mask used in the kmalloc() call when allocating memory
416 * Returns name of attached handler, NULL if no handler is attached.
417 * Caller must take care to free the returned string.
419 const char *scsi_dh_attached_handler_name(struct request_queue *q, gfp_t gfp)
421 struct scsi_device *sdev;
422 const char *handler_name = NULL;
424 sdev = scsi_device_from_queue(q);
429 handler_name = kstrdup(sdev->handler->name, gfp);
430 put_device(&sdev->sdev_gendev);
433 EXPORT_SYMBOL_GPL(scsi_dh_attached_handler_name);