1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * SCSI device handler infrastructure. |
4 | * |
5 | * Copyright IBM Corporation, 2007 |
6 | * Authors: |
7 | * Chandra Seetharaman <sekharan@us.ibm.com> |
8 | * Mike Anderson <andmike@linux.vnet.ibm.com> |
9 | */ |
10 | |
11 | #include <linux/slab.h> |
12 | #include <linux/module.h> |
13 | #include <scsi/scsi_dh.h> |
14 | #include "scsi_priv.h" |
15 | |
16 | static DEFINE_SPINLOCK(list_lock); |
17 | static LIST_HEAD(scsi_dh_list); |
18 | |
19 | struct scsi_dh_blist { |
20 | const char *vendor; |
21 | const char *model; |
22 | const char *driver; |
23 | }; |
24 | |
25 | static const struct scsi_dh_blist scsi_dh_blist[] = { |
26 | {"DGC" , "RAID" , "emc" }, |
27 | {"DGC" , "DISK" , "emc" }, |
28 | {"DGC" , "VRAID" , "emc" }, |
29 | |
30 | {"COMPAQ" , "MSA1000 VOLUME" , "hp_sw" }, |
31 | {"COMPAQ" , "HSV110" , "hp_sw" }, |
32 | {"HP" , "HSV100" , "hp_sw" }, |
33 | {"DEC" , "HSG80" , "hp_sw" }, |
34 | |
35 | {"IBM" , "1722" , "rdac" , }, |
36 | {"IBM" , "1724" , "rdac" , }, |
37 | {"IBM" , "1726" , "rdac" , }, |
38 | {"IBM" , "1742" , "rdac" , }, |
39 | {"IBM" , "1745" , "rdac" , }, |
40 | {"IBM" , "1746" , "rdac" , }, |
41 | {"IBM" , "1813" , "rdac" , }, |
42 | {"IBM" , "1814" , "rdac" , }, |
43 | {"IBM" , "1815" , "rdac" , }, |
44 | {"IBM" , "1818" , "rdac" , }, |
45 | {"IBM" , "3526" , "rdac" , }, |
46 | {"IBM" , "3542" , "rdac" , }, |
47 | {"IBM" , "3552" , "rdac" , }, |
48 | {"SGI" , "TP9300" , "rdac" , }, |
49 | {"SGI" , "TP9400" , "rdac" , }, |
50 | {"SGI" , "TP9500" , "rdac" , }, |
51 | {"SGI" , "TP9700" , "rdac" , }, |
52 | {"SGI" , "IS" , "rdac" , }, |
53 | {"STK" , "OPENstorage" , "rdac" , }, |
54 | {"STK" , "FLEXLINE 380" , "rdac" , }, |
55 | {"STK" , "BladeCtlr" , "rdac" , }, |
56 | {"SUN" , "CSM" , "rdac" , }, |
57 | {"SUN" , "LCSM100" , "rdac" , }, |
58 | {"SUN" , "STK6580_6780" , "rdac" , }, |
59 | {"SUN" , "SUN_6180" , "rdac" , }, |
60 | {"SUN" , "ArrayStorage" , "rdac" , }, |
61 | {"DELL" , "MD3" , "rdac" , }, |
62 | {"NETAPP" , "INF-01-00" , "rdac" , }, |
63 | {"LSI" , "INF-01-00" , "rdac" , }, |
64 | {"ENGENIO" , "INF-01-00" , "rdac" , }, |
65 | {"LENOVO" , "DE_Series" , "rdac" , }, |
66 | {"FUJITSU" , "ETERNUS_AHB" , "rdac" , }, |
67 | {NULL, NULL, NULL }, |
68 | }; |
69 | |
70 | static const char * |
71 | scsi_dh_find_driver(struct scsi_device *sdev) |
72 | { |
73 | const struct scsi_dh_blist *b; |
74 | |
75 | if (scsi_device_tpgs(sdev)) |
76 | return "alua" ; |
77 | |
78 | for (b = scsi_dh_blist; b->vendor; b++) { |
79 | if (!strncmp(sdev->vendor, b->vendor, strlen(b->vendor)) && |
80 | !strncmp(sdev->model, b->model, strlen(b->model))) { |
81 | return b->driver; |
82 | } |
83 | } |
84 | return NULL; |
85 | } |
86 | |
87 | |
88 | static struct scsi_device_handler *__scsi_dh_lookup(const char *name) |
89 | { |
90 | struct scsi_device_handler *tmp, *found = NULL; |
91 | |
92 | spin_lock(lock: &list_lock); |
93 | list_for_each_entry(tmp, &scsi_dh_list, list) { |
94 | if (!strncmp(tmp->name, name, strlen(tmp->name))) { |
95 | found = tmp; |
96 | break; |
97 | } |
98 | } |
99 | spin_unlock(lock: &list_lock); |
100 | return found; |
101 | } |
102 | |
103 | static struct scsi_device_handler *scsi_dh_lookup(const char *name) |
104 | { |
105 | struct scsi_device_handler *dh; |
106 | |
107 | if (!name || strlen(name) == 0) |
108 | return NULL; |
109 | |
110 | dh = __scsi_dh_lookup(name); |
111 | if (!dh) { |
112 | request_module("scsi_dh_%s" , name); |
113 | dh = __scsi_dh_lookup(name); |
114 | } |
115 | |
116 | return dh; |
117 | } |
118 | |
119 | /* |
120 | * scsi_dh_handler_attach - Attach a device handler to a device |
121 | * @sdev - SCSI device the device handler should attach to |
122 | * @scsi_dh - The device handler to attach |
123 | */ |
124 | static int scsi_dh_handler_attach(struct scsi_device *sdev, |
125 | struct scsi_device_handler *scsi_dh) |
126 | { |
127 | int error, ret = 0; |
128 | |
129 | if (!try_module_get(module: scsi_dh->module)) |
130 | return -EINVAL; |
131 | |
132 | error = scsi_dh->attach(sdev); |
133 | if (error != SCSI_DH_OK) { |
134 | switch (error) { |
135 | case SCSI_DH_NOMEM: |
136 | ret = -ENOMEM; |
137 | break; |
138 | case SCSI_DH_RES_TEMP_UNAVAIL: |
139 | ret = -EAGAIN; |
140 | break; |
141 | case SCSI_DH_DEV_UNSUPP: |
142 | case SCSI_DH_NOSYS: |
143 | ret = -ENODEV; |
144 | break; |
145 | default: |
146 | ret = -EINVAL; |
147 | break; |
148 | } |
149 | if (ret != -ENODEV) |
150 | sdev_printk(KERN_ERR, sdev, "%s: Attach failed (%d)\n" , |
151 | scsi_dh->name, error); |
152 | module_put(module: scsi_dh->module); |
153 | } else |
154 | sdev->handler = scsi_dh; |
155 | |
156 | return ret; |
157 | } |
158 | |
159 | /* |
160 | * scsi_dh_handler_detach - Detach a device handler from a device |
161 | * @sdev - SCSI device the device handler should be detached from |
162 | */ |
163 | static void scsi_dh_handler_detach(struct scsi_device *sdev) |
164 | { |
165 | sdev->handler->detach(sdev); |
166 | sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n" , sdev->handler->name); |
167 | module_put(module: sdev->handler->module); |
168 | } |
169 | |
170 | void scsi_dh_add_device(struct scsi_device *sdev) |
171 | { |
172 | struct scsi_device_handler *devinfo = NULL; |
173 | const char *drv; |
174 | |
175 | drv = scsi_dh_find_driver(sdev); |
176 | if (drv) |
177 | devinfo = __scsi_dh_lookup(name: drv); |
178 | /* |
179 | * device_handler is optional, so ignore errors |
180 | * from scsi_dh_handler_attach() |
181 | */ |
182 | if (devinfo) |
183 | (void)scsi_dh_handler_attach(sdev, scsi_dh: devinfo); |
184 | } |
185 | |
186 | void scsi_dh_release_device(struct scsi_device *sdev) |
187 | { |
188 | if (sdev->handler) |
189 | scsi_dh_handler_detach(sdev); |
190 | } |
191 | |
192 | /* |
193 | * scsi_register_device_handler - register a device handler personality |
194 | * module. |
195 | * @scsi_dh - device handler to be registered. |
196 | * |
197 | * Returns 0 on success, -EBUSY if handler already registered. |
198 | */ |
199 | int scsi_register_device_handler(struct scsi_device_handler *scsi_dh) |
200 | { |
201 | if (__scsi_dh_lookup(name: scsi_dh->name)) |
202 | return -EBUSY; |
203 | |
204 | if (!scsi_dh->attach || !scsi_dh->detach) |
205 | return -EINVAL; |
206 | |
207 | spin_lock(lock: &list_lock); |
208 | list_add(new: &scsi_dh->list, head: &scsi_dh_list); |
209 | spin_unlock(lock: &list_lock); |
210 | |
211 | printk(KERN_INFO "%s: device handler registered\n" , scsi_dh->name); |
212 | |
213 | return SCSI_DH_OK; |
214 | } |
215 | EXPORT_SYMBOL_GPL(scsi_register_device_handler); |
216 | |
217 | /* |
218 | * scsi_unregister_device_handler - register a device handler personality |
219 | * module. |
220 | * @scsi_dh - device handler to be unregistered. |
221 | * |
222 | * Returns 0 on success, -ENODEV if handler not registered. |
223 | */ |
224 | int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh) |
225 | { |
226 | if (!__scsi_dh_lookup(name: scsi_dh->name)) |
227 | return -ENODEV; |
228 | |
229 | spin_lock(lock: &list_lock); |
230 | list_del(entry: &scsi_dh->list); |
231 | spin_unlock(lock: &list_lock); |
232 | printk(KERN_INFO "%s: device handler unregistered\n" , scsi_dh->name); |
233 | |
234 | return SCSI_DH_OK; |
235 | } |
236 | EXPORT_SYMBOL_GPL(scsi_unregister_device_handler); |
237 | |
238 | /* |
239 | * scsi_dh_activate - activate the path associated with the scsi_device |
240 | * corresponding to the given request queue. |
241 | * Returns immediately without waiting for activation to be completed. |
242 | * @q - Request queue that is associated with the scsi_device to be |
243 | * activated. |
244 | * @fn - Function to be called upon completion of the activation. |
245 | * Function fn is called with data (below) and the error code. |
246 | * Function fn may be called from the same calling context. So, |
247 | * do not hold the lock in the caller which may be needed in fn. |
248 | * @data - data passed to the function fn upon completion. |
249 | * |
250 | */ |
251 | int scsi_dh_activate(struct request_queue *q, activate_complete fn, void *data) |
252 | { |
253 | struct scsi_device *sdev; |
254 | int err = SCSI_DH_NOSYS; |
255 | |
256 | sdev = scsi_device_from_queue(q); |
257 | if (!sdev) { |
258 | if (fn) |
259 | fn(data, err); |
260 | return err; |
261 | } |
262 | |
263 | if (!sdev->handler) |
264 | goto out_fn; |
265 | err = SCSI_DH_NOTCONN; |
266 | if (sdev->sdev_state == SDEV_CANCEL || |
267 | sdev->sdev_state == SDEV_DEL) |
268 | goto out_fn; |
269 | |
270 | err = SCSI_DH_DEV_OFFLINED; |
271 | if (sdev->sdev_state == SDEV_OFFLINE) |
272 | goto out_fn; |
273 | |
274 | if (sdev->handler->activate) |
275 | err = sdev->handler->activate(sdev, fn, data); |
276 | |
277 | out_put_device: |
278 | put_device(dev: &sdev->sdev_gendev); |
279 | return err; |
280 | |
281 | out_fn: |
282 | if (fn) |
283 | fn(data, err); |
284 | goto out_put_device; |
285 | } |
286 | EXPORT_SYMBOL_GPL(scsi_dh_activate); |
287 | |
288 | /* |
289 | * scsi_dh_set_params - set the parameters for the device as per the |
290 | * string specified in params. |
291 | * @q - Request queue that is associated with the scsi_device for |
292 | * which the parameters to be set. |
293 | * @params - parameters in the following format |
294 | * "no_of_params\0param1\0param2\0param3\0...\0" |
295 | * for example, string for 2 parameters with value 10 and 21 |
296 | * is specified as "2\010\021\0". |
297 | */ |
298 | int scsi_dh_set_params(struct request_queue *q, const char *params) |
299 | { |
300 | struct scsi_device *sdev; |
301 | int err = -SCSI_DH_NOSYS; |
302 | |
303 | sdev = scsi_device_from_queue(q); |
304 | if (!sdev) |
305 | return err; |
306 | |
307 | if (sdev->handler && sdev->handler->set_params) |
308 | err = sdev->handler->set_params(sdev, params); |
309 | put_device(dev: &sdev->sdev_gendev); |
310 | return err; |
311 | } |
312 | EXPORT_SYMBOL_GPL(scsi_dh_set_params); |
313 | |
314 | /* |
315 | * scsi_dh_attach - Attach device handler |
316 | * @q - Request queue that is associated with the scsi_device |
317 | * the handler should be attached to |
318 | * @name - name of the handler to attach |
319 | */ |
320 | int scsi_dh_attach(struct request_queue *q, const char *name) |
321 | { |
322 | struct scsi_device *sdev; |
323 | struct scsi_device_handler *scsi_dh; |
324 | int err = 0; |
325 | |
326 | sdev = scsi_device_from_queue(q); |
327 | if (!sdev) |
328 | return -ENODEV; |
329 | |
330 | scsi_dh = scsi_dh_lookup(name); |
331 | if (!scsi_dh) { |
332 | err = -EINVAL; |
333 | goto out_put_device; |
334 | } |
335 | |
336 | if (sdev->handler) { |
337 | if (sdev->handler != scsi_dh) |
338 | err = -EBUSY; |
339 | goto out_put_device; |
340 | } |
341 | |
342 | err = scsi_dh_handler_attach(sdev, scsi_dh); |
343 | |
344 | out_put_device: |
345 | put_device(dev: &sdev->sdev_gendev); |
346 | return err; |
347 | } |
348 | EXPORT_SYMBOL_GPL(scsi_dh_attach); |
349 | |
350 | /* |
351 | * scsi_dh_attached_handler_name - Get attached device handler's name |
352 | * @q - Request queue that is associated with the scsi_device |
353 | * that may have a device handler attached |
354 | * @gfp - the GFP mask used in the kmalloc() call when allocating memory |
355 | * |
356 | * Returns name of attached handler, NULL if no handler is attached. |
357 | * Caller must take care to free the returned string. |
358 | */ |
359 | const char *scsi_dh_attached_handler_name(struct request_queue *q, gfp_t gfp) |
360 | { |
361 | struct scsi_device *sdev; |
362 | const char *handler_name = NULL; |
363 | |
364 | sdev = scsi_device_from_queue(q); |
365 | if (!sdev) |
366 | return NULL; |
367 | |
368 | if (sdev->handler) |
369 | handler_name = kstrdup(s: sdev->handler->name, gfp); |
370 | put_device(dev: &sdev->sdev_gendev); |
371 | return handler_name; |
372 | } |
373 | EXPORT_SYMBOL_GPL(scsi_dh_attached_handler_name); |
374 | |