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 {"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(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);
136 sdev_printk(KERN_ERR, sdev, "%s: Attach failed (%d)\n",
137 scsi_dh->name, error);
138 module_put(scsi_dh->module);
140 sdev->handler = scsi_dh;
146 * scsi_dh_handler_detach - Detach a device handler from a device
147 * @sdev - SCSI device the device handler should be detached from
149 static void scsi_dh_handler_detach(struct scsi_device *sdev)
151 sdev->handler->detach(sdev);
152 sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", sdev->handler->name);
153 module_put(sdev->handler->module);
157 * Functions for sysfs attribute 'dh_state'
160 store_dh_state(struct device *dev, struct device_attribute *attr,
161 const char *buf, size_t count)
163 struct scsi_device *sdev = to_scsi_device(dev);
164 struct scsi_device_handler *scsi_dh;
167 if (sdev->sdev_state == SDEV_CANCEL ||
168 sdev->sdev_state == SDEV_DEL)
171 if (!sdev->handler) {
173 * Attach to a device handler
175 scsi_dh = scsi_dh_lookup(buf);
178 err = scsi_dh_handler_attach(sdev, scsi_dh);
180 if (!strncmp(buf, "detach", 6)) {
182 * Detach from a device handler
184 scsi_dh_handler_detach(sdev);
186 } else if (!strncmp(buf, "activate", 8)) {
188 * Activate a device handler
190 if (sdev->handler->activate)
191 err = sdev->handler->activate(sdev, NULL, NULL);
197 return err<0?err:count;
201 show_dh_state(struct device *dev, struct device_attribute *attr, char *buf)
203 struct scsi_device *sdev = to_scsi_device(dev);
206 return snprintf(buf, 20, "detached\n");
208 return snprintf(buf, 20, "%s\n", sdev->handler->name);
211 static struct device_attribute scsi_dh_state_attr =
212 __ATTR(dh_state, S_IRUGO | S_IWUSR, show_dh_state,
215 int scsi_dh_add_device(struct scsi_device *sdev)
217 struct scsi_device_handler *devinfo = NULL;
221 err = device_create_file(&sdev->sdev_gendev, &scsi_dh_state_attr);
225 drv = scsi_dh_find_driver(sdev);
227 devinfo = scsi_dh_lookup(drv);
229 err = scsi_dh_handler_attach(sdev, devinfo);
233 void scsi_dh_remove_device(struct scsi_device *sdev)
236 scsi_dh_handler_detach(sdev);
237 device_remove_file(&sdev->sdev_gendev, &scsi_dh_state_attr);
241 * scsi_register_device_handler - register a device handler personality
243 * @scsi_dh - device handler to be registered.
245 * Returns 0 on success, -EBUSY if handler already registered.
247 int scsi_register_device_handler(struct scsi_device_handler *scsi_dh)
249 if (__scsi_dh_lookup(scsi_dh->name))
252 if (!scsi_dh->attach || !scsi_dh->detach)
255 spin_lock(&list_lock);
256 list_add(&scsi_dh->list, &scsi_dh_list);
257 spin_unlock(&list_lock);
259 printk(KERN_INFO "%s: device handler registered\n", scsi_dh->name);
263 EXPORT_SYMBOL_GPL(scsi_register_device_handler);
266 * scsi_unregister_device_handler - register a device handler personality
268 * @scsi_dh - device handler to be unregistered.
270 * Returns 0 on success, -ENODEV if handler not registered.
272 int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh)
274 if (!__scsi_dh_lookup(scsi_dh->name))
277 spin_lock(&list_lock);
278 list_del(&scsi_dh->list);
279 spin_unlock(&list_lock);
280 printk(KERN_INFO "%s: device handler unregistered\n", scsi_dh->name);
284 EXPORT_SYMBOL_GPL(scsi_unregister_device_handler);
286 static struct scsi_device *get_sdev_from_queue(struct request_queue *q)
288 struct scsi_device *sdev;
291 spin_lock_irqsave(q->queue_lock, flags);
293 if (!sdev || !get_device(&sdev->sdev_gendev))
295 spin_unlock_irqrestore(q->queue_lock, flags);
301 * scsi_dh_activate - activate the path associated with the scsi_device
302 * corresponding to the given request queue.
303 * Returns immediately without waiting for activation to be completed.
304 * @q - Request queue that is associated with the scsi_device to be
306 * @fn - Function to be called upon completion of the activation.
307 * Function fn is called with data (below) and the error code.
308 * Function fn may be called from the same calling context. So,
309 * do not hold the lock in the caller which may be needed in fn.
310 * @data - data passed to the function fn upon completion.
313 int scsi_dh_activate(struct request_queue *q, activate_complete fn, void *data)
315 struct scsi_device *sdev;
316 int err = SCSI_DH_NOSYS;
318 sdev = get_sdev_from_queue(q);
327 if (sdev->sdev_state == SDEV_CANCEL ||
328 sdev->sdev_state == SDEV_DEL)
331 err = SCSI_DH_DEV_OFFLINED;
332 if (sdev->sdev_state == SDEV_OFFLINE)
335 if (sdev->handler->activate)
336 err = sdev->handler->activate(sdev, fn, data);
339 put_device(&sdev->sdev_gendev);
347 EXPORT_SYMBOL_GPL(scsi_dh_activate);
350 * scsi_dh_set_params - set the parameters for the device as per the
351 * string specified in params.
352 * @q - Request queue that is associated with the scsi_device for
353 * which the parameters to be set.
354 * @params - parameters in the following format
355 * "no_of_params\0param1\0param2\0param3\0...\0"
356 * for example, string for 2 parameters with value 10 and 21
357 * is specified as "2\010\021\0".
359 int scsi_dh_set_params(struct request_queue *q, const char *params)
361 struct scsi_device *sdev;
362 int err = -SCSI_DH_NOSYS;
364 sdev = get_sdev_from_queue(q);
368 if (sdev->handler && sdev->handler->set_params)
369 err = sdev->handler->set_params(sdev, params);
370 put_device(&sdev->sdev_gendev);
373 EXPORT_SYMBOL_GPL(scsi_dh_set_params);
376 * scsi_dh_attach - Attach device handler
377 * @q - Request queue that is associated with the scsi_device
378 * the handler should be attached to
379 * @name - name of the handler to attach
381 int scsi_dh_attach(struct request_queue *q, const char *name)
383 struct scsi_device *sdev;
384 struct scsi_device_handler *scsi_dh;
387 sdev = get_sdev_from_queue(q);
391 scsi_dh = scsi_dh_lookup(name);
398 if (sdev->handler != scsi_dh)
403 err = scsi_dh_handler_attach(sdev, scsi_dh);
406 put_device(&sdev->sdev_gendev);
409 EXPORT_SYMBOL_GPL(scsi_dh_attach);
412 * scsi_dh_attached_handler_name - Get attached device handler's name
413 * @q - Request queue that is associated with the scsi_device
414 * that may have a device handler attached
415 * @gfp - the GFP mask used in the kmalloc() call when allocating memory
417 * Returns name of attached handler, NULL if no handler is attached.
418 * Caller must take care to free the returned string.
420 const char *scsi_dh_attached_handler_name(struct request_queue *q, gfp_t gfp)
422 struct scsi_device *sdev;
423 const char *handler_name = NULL;
425 sdev = get_sdev_from_queue(q);
430 handler_name = kstrdup(sdev->handler->name, gfp);
431 put_device(&sdev->sdev_gendev);
434 EXPORT_SYMBOL_GPL(scsi_dh_attached_handler_name);