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("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);
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 sdev_printk(KERN_WARNING, sdev,
185 "can't detach handler %s.\n",
186 sdev->handler->name);
188 } else if (!strncmp(buf, "activate", 8)) {
190 * Activate a device handler
192 if (sdev->handler->activate)
193 err = sdev->handler->activate(sdev, NULL, NULL);
199 return err<0?err:count;
203 show_dh_state(struct device *dev, struct device_attribute *attr, char *buf)
205 struct scsi_device *sdev = to_scsi_device(dev);
208 return snprintf(buf, 20, "detached\n");
210 return snprintf(buf, 20, "%s\n", sdev->handler->name);
213 static struct device_attribute scsi_dh_state_attr =
214 __ATTR(dh_state, S_IRUGO | S_IWUSR, show_dh_state,
217 int scsi_dh_add_device(struct scsi_device *sdev)
219 struct scsi_device_handler *devinfo = NULL;
223 err = device_create_file(&sdev->sdev_gendev, &scsi_dh_state_attr);
227 drv = scsi_dh_find_driver(sdev);
229 devinfo = scsi_dh_lookup(drv);
231 err = scsi_dh_handler_attach(sdev, devinfo);
235 void scsi_dh_remove_device(struct scsi_device *sdev)
238 scsi_dh_handler_detach(sdev);
239 device_remove_file(&sdev->sdev_gendev, &scsi_dh_state_attr);
243 * scsi_register_device_handler - register a device handler personality
245 * @scsi_dh - device handler to be registered.
247 * Returns 0 on success, -EBUSY if handler already registered.
249 int scsi_register_device_handler(struct scsi_device_handler *scsi_dh)
251 if (__scsi_dh_lookup(scsi_dh->name))
254 if (!scsi_dh->attach || !scsi_dh->detach)
257 spin_lock(&list_lock);
258 list_add(&scsi_dh->list, &scsi_dh_list);
259 spin_unlock(&list_lock);
261 printk(KERN_INFO "%s: device handler registered\n", scsi_dh->name);
265 EXPORT_SYMBOL_GPL(scsi_register_device_handler);
268 * scsi_unregister_device_handler - register a device handler personality
270 * @scsi_dh - device handler to be unregistered.
272 * Returns 0 on success, -ENODEV if handler not registered.
274 int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh)
276 if (!__scsi_dh_lookup(scsi_dh->name))
279 spin_lock(&list_lock);
280 list_del(&scsi_dh->list);
281 spin_unlock(&list_lock);
282 printk(KERN_INFO "%s: device handler unregistered\n", scsi_dh->name);
286 EXPORT_SYMBOL_GPL(scsi_unregister_device_handler);
288 static struct scsi_device *get_sdev_from_queue(struct request_queue *q)
290 struct scsi_device *sdev;
293 spin_lock_irqsave(q->queue_lock, flags);
295 if (!sdev || !get_device(&sdev->sdev_gendev))
297 spin_unlock_irqrestore(q->queue_lock, flags);
303 * scsi_dh_activate - activate the path associated with the scsi_device
304 * corresponding to the given request queue.
305 * Returns immediately without waiting for activation to be completed.
306 * @q - Request queue that is associated with the scsi_device to be
308 * @fn - Function to be called upon completion of the activation.
309 * Function fn is called with data (below) and the error code.
310 * Function fn may be called from the same calling context. So,
311 * do not hold the lock in the caller which may be needed in fn.
312 * @data - data passed to the function fn upon completion.
315 int scsi_dh_activate(struct request_queue *q, activate_complete fn, void *data)
317 struct scsi_device *sdev;
318 int err = SCSI_DH_NOSYS;
320 sdev = get_sdev_from_queue(q);
329 err = SCSI_DH_NOTCONN;
330 if (sdev->sdev_state == SDEV_CANCEL ||
331 sdev->sdev_state == SDEV_DEL)
334 err = SCSI_DH_DEV_OFFLINED;
335 if (sdev->sdev_state == SDEV_OFFLINE)
338 if (sdev->handler->activate)
339 err = sdev->handler->activate(sdev, fn, data);
342 put_device(&sdev->sdev_gendev);
350 EXPORT_SYMBOL_GPL(scsi_dh_activate);
353 * scsi_dh_set_params - set the parameters for the device as per the
354 * string specified in params.
355 * @q - Request queue that is associated with the scsi_device for
356 * which the parameters to be set.
357 * @params - parameters in the following format
358 * "no_of_params\0param1\0param2\0param3\0...\0"
359 * for example, string for 2 parameters with value 10 and 21
360 * is specified as "2\010\021\0".
362 int scsi_dh_set_params(struct request_queue *q, const char *params)
364 struct scsi_device *sdev;
365 int err = -SCSI_DH_NOSYS;
367 sdev = get_sdev_from_queue(q);
371 if (sdev->handler && sdev->handler->set_params)
372 err = sdev->handler->set_params(sdev, params);
373 put_device(&sdev->sdev_gendev);
376 EXPORT_SYMBOL_GPL(scsi_dh_set_params);
379 * scsi_dh_attach - Attach device handler
380 * @q - Request queue that is associated with the scsi_device
381 * the handler should be attached to
382 * @name - name of the handler to attach
384 int scsi_dh_attach(struct request_queue *q, const char *name)
386 struct scsi_device *sdev;
387 struct scsi_device_handler *scsi_dh;
390 sdev = get_sdev_from_queue(q);
394 scsi_dh = scsi_dh_lookup(name);
401 if (sdev->handler != scsi_dh)
406 err = scsi_dh_handler_attach(sdev, scsi_dh);
409 put_device(&sdev->sdev_gendev);
412 EXPORT_SYMBOL_GPL(scsi_dh_attach);
415 * scsi_dh_attached_handler_name - Get attached device handler's name
416 * @q - Request queue that is associated with the scsi_device
417 * that may have a device handler attached
418 * @gfp - the GFP mask used in the kmalloc() call when allocating memory
420 * Returns name of attached handler, NULL if no handler is attached.
421 * Caller must take care to free the returned string.
423 const char *scsi_dh_attached_handler_name(struct request_queue *q, gfp_t gfp)
425 struct scsi_device *sdev;
426 const char *handler_name = NULL;
428 sdev = get_sdev_from_queue(q);
433 handler_name = kstrdup(sdev->handler->name, gfp);
434 put_device(&sdev->sdev_gendev);
437 EXPORT_SYMBOL_GPL(scsi_dh_attached_handler_name);