Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * dcssblk.c -- the S/390 block driver for dcss memory | |
3 | * | |
4 | * Authors: Carsten Otte, Stefan Weinhuber, Gerald Schaefer | |
5 | */ | |
6 | ||
93098bf0 HY |
7 | #define KMSG_COMPONENT "dcssblk" |
8 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt | |
9 | ||
1da177e4 LT |
10 | #include <linux/module.h> |
11 | #include <linux/moduleparam.h> | |
12 | #include <linux/ctype.h> | |
13 | #include <linux/errno.h> | |
14 | #include <linux/init.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/blkdev.h> | |
1da177e4 LT |
17 | #include <linux/completion.h> |
18 | #include <linux/interrupt.h> | |
c369527f GS |
19 | #include <linux/platform_device.h> |
20 | #include <asm/extmem.h> | |
21 | #include <asm/io.h> | |
1da177e4 | 22 | |
1da177e4 LT |
23 | #define DCSSBLK_NAME "dcssblk" |
24 | #define DCSSBLK_MINORS_PER_DISK 1 | |
25 | #define DCSSBLK_PARM_LEN 400 | |
98df67b3 | 26 | #define DCSS_BUS_ID_SIZE 20 |
1da177e4 | 27 | |
46d74326 | 28 | static int dcssblk_open(struct block_device *bdev, fmode_t mode); |
db2a144b | 29 | static void dcssblk_release(struct gendisk *disk, fmode_t mode); |
5a7bbad2 | 30 | static void dcssblk_make_request(struct request_queue *q, struct bio *bio); |
420edbcc | 31 | static int dcssblk_direct_access(struct block_device *bdev, sector_t secnum, |
30afcb4b | 32 | void **kaddr, unsigned long *pfn); |
1da177e4 LT |
33 | |
34 | static char dcssblk_segments[DCSSBLK_PARM_LEN] = "\0"; | |
35 | ||
36 | static int dcssblk_major; | |
83d5cde4 | 37 | static const struct block_device_operations dcssblk_devops = { |
420edbcc | 38 | .owner = THIS_MODULE, |
46d74326 AV |
39 | .open = dcssblk_open, |
40 | .release = dcssblk_release, | |
420edbcc | 41 | .direct_access = dcssblk_direct_access, |
1da177e4 LT |
42 | }; |
43 | ||
b2300b9e HY |
44 | struct dcssblk_dev_info { |
45 | struct list_head lh; | |
46 | struct device dev; | |
98df67b3 | 47 | char segment_name[DCSS_BUS_ID_SIZE]; |
b2300b9e HY |
48 | atomic_t use_count; |
49 | struct gendisk *gd; | |
50 | unsigned long start; | |
51 | unsigned long end; | |
52 | int segment_type; | |
53 | unsigned char save_pending; | |
54 | unsigned char is_shared; | |
55 | struct request_queue *dcssblk_queue; | |
56 | int num_of_segments; | |
57 | struct list_head seg_list; | |
58 | }; | |
59 | ||
60 | struct segment_info { | |
61 | struct list_head lh; | |
98df67b3 | 62 | char segment_name[DCSS_BUS_ID_SIZE]; |
b2300b9e HY |
63 | unsigned long start; |
64 | unsigned long end; | |
65 | int segment_type; | |
66 | }; | |
67 | ||
e404e274 | 68 | static ssize_t dcssblk_add_store(struct device * dev, struct device_attribute *attr, const char * buf, |
1da177e4 | 69 | size_t count); |
e404e274 | 70 | static ssize_t dcssblk_remove_store(struct device * dev, struct device_attribute *attr, const char * buf, |
1da177e4 | 71 | size_t count); |
1da177e4 LT |
72 | |
73 | static DEVICE_ATTR(add, S_IWUSR, NULL, dcssblk_add_store); | |
74 | static DEVICE_ATTR(remove, S_IWUSR, NULL, dcssblk_remove_store); | |
1da177e4 LT |
75 | |
76 | static struct device *dcssblk_root_dev; | |
77 | ||
c11ca97e | 78 | static LIST_HEAD(dcssblk_devices); |
1da177e4 LT |
79 | static struct rw_semaphore dcssblk_devices_sem; |
80 | ||
81 | /* | |
82 | * release function for segment device. | |
83 | */ | |
84 | static void | |
85 | dcssblk_release_segment(struct device *dev) | |
86 | { | |
b2300b9e HY |
87 | struct dcssblk_dev_info *dev_info; |
88 | struct segment_info *entry, *temp; | |
89 | ||
90 | dev_info = container_of(dev, struct dcssblk_dev_info, dev); | |
91 | list_for_each_entry_safe(entry, temp, &dev_info->seg_list, lh) { | |
92 | list_del(&entry->lh); | |
93 | kfree(entry); | |
94 | } | |
95 | kfree(dev_info); | |
1da177e4 LT |
96 | module_put(THIS_MODULE); |
97 | } | |
98 | ||
99 | /* | |
100 | * get a minor number. needs to be called with | |
101 | * down_write(&dcssblk_devices_sem) and the | |
102 | * device needs to be enqueued before the semaphore is | |
103 | * freed. | |
104 | */ | |
4d284cac | 105 | static int |
1da177e4 LT |
106 | dcssblk_assign_free_minor(struct dcssblk_dev_info *dev_info) |
107 | { | |
108 | int minor, found; | |
109 | struct dcssblk_dev_info *entry; | |
110 | ||
111 | if (dev_info == NULL) | |
112 | return -EINVAL; | |
113 | for (minor = 0; minor < (1<<MINORBITS); minor++) { | |
114 | found = 0; | |
115 | // test if minor available | |
116 | list_for_each_entry(entry, &dcssblk_devices, lh) | |
d0591485 | 117 | if (minor == entry->gd->first_minor) |
1da177e4 LT |
118 | found++; |
119 | if (!found) break; // got unused minor | |
120 | } | |
121 | if (found) | |
122 | return -EBUSY; | |
123 | dev_info->gd->first_minor = minor; | |
124 | return 0; | |
125 | } | |
126 | ||
127 | /* | |
128 | * get the struct dcssblk_dev_info from dcssblk_devices | |
129 | * for the given name. | |
130 | * down_read(&dcssblk_devices_sem) must be held. | |
131 | */ | |
132 | static struct dcssblk_dev_info * | |
133 | dcssblk_get_device_by_name(char *name) | |
134 | { | |
135 | struct dcssblk_dev_info *entry; | |
136 | ||
137 | list_for_each_entry(entry, &dcssblk_devices, lh) { | |
138 | if (!strcmp(name, entry->segment_name)) { | |
139 | return entry; | |
140 | } | |
141 | } | |
142 | return NULL; | |
143 | } | |
144 | ||
b2300b9e HY |
145 | /* |
146 | * get the struct segment_info from seg_list | |
147 | * for the given name. | |
148 | * down_read(&dcssblk_devices_sem) must be held. | |
149 | */ | |
150 | static struct segment_info * | |
151 | dcssblk_get_segment_by_name(char *name) | |
152 | { | |
153 | struct dcssblk_dev_info *dev_info; | |
154 | struct segment_info *entry; | |
155 | ||
156 | list_for_each_entry(dev_info, &dcssblk_devices, lh) { | |
157 | list_for_each_entry(entry, &dev_info->seg_list, lh) { | |
158 | if (!strcmp(name, entry->segment_name)) | |
159 | return entry; | |
160 | } | |
161 | } | |
162 | return NULL; | |
163 | } | |
164 | ||
165 | /* | |
166 | * get the highest address of the multi-segment block. | |
167 | */ | |
168 | static unsigned long | |
169 | dcssblk_find_highest_addr(struct dcssblk_dev_info *dev_info) | |
170 | { | |
171 | unsigned long highest_addr; | |
172 | struct segment_info *entry; | |
173 | ||
174 | highest_addr = 0; | |
175 | list_for_each_entry(entry, &dev_info->seg_list, lh) { | |
176 | if (highest_addr < entry->end) | |
177 | highest_addr = entry->end; | |
178 | } | |
179 | return highest_addr; | |
180 | } | |
181 | ||
182 | /* | |
183 | * get the lowest address of the multi-segment block. | |
184 | */ | |
185 | static unsigned long | |
186 | dcssblk_find_lowest_addr(struct dcssblk_dev_info *dev_info) | |
187 | { | |
188 | int set_first; | |
189 | unsigned long lowest_addr; | |
190 | struct segment_info *entry; | |
191 | ||
192 | set_first = 0; | |
193 | lowest_addr = 0; | |
194 | list_for_each_entry(entry, &dev_info->seg_list, lh) { | |
195 | if (set_first == 0) { | |
196 | lowest_addr = entry->start; | |
197 | set_first = 1; | |
198 | } else { | |
199 | if (lowest_addr > entry->start) | |
200 | lowest_addr = entry->start; | |
201 | } | |
202 | } | |
203 | return lowest_addr; | |
204 | } | |
205 | ||
206 | /* | |
207 | * Check continuity of segments. | |
208 | */ | |
209 | static int | |
210 | dcssblk_is_continuous(struct dcssblk_dev_info *dev_info) | |
211 | { | |
212 | int i, j, rc; | |
213 | struct segment_info *sort_list, *entry, temp; | |
214 | ||
215 | if (dev_info->num_of_segments <= 1) | |
216 | return 0; | |
217 | ||
218 | sort_list = kzalloc( | |
219 | sizeof(struct segment_info) * dev_info->num_of_segments, | |
220 | GFP_KERNEL); | |
221 | if (sort_list == NULL) | |
222 | return -ENOMEM; | |
223 | i = 0; | |
224 | list_for_each_entry(entry, &dev_info->seg_list, lh) { | |
225 | memcpy(&sort_list[i], entry, sizeof(struct segment_info)); | |
226 | i++; | |
227 | } | |
228 | ||
229 | /* sort segments */ | |
230 | for (i = 0; i < dev_info->num_of_segments; i++) | |
231 | for (j = 0; j < dev_info->num_of_segments; j++) | |
232 | if (sort_list[j].start > sort_list[i].start) { | |
233 | memcpy(&temp, &sort_list[i], | |
234 | sizeof(struct segment_info)); | |
235 | memcpy(&sort_list[i], &sort_list[j], | |
236 | sizeof(struct segment_info)); | |
237 | memcpy(&sort_list[j], &temp, | |
238 | sizeof(struct segment_info)); | |
239 | } | |
240 | ||
241 | /* check continuity */ | |
242 | for (i = 0; i < dev_info->num_of_segments - 1; i++) { | |
243 | if ((sort_list[i].end + 1) != sort_list[i+1].start) { | |
93098bf0 HY |
244 | pr_err("Adjacent DCSSs %s and %s are not " |
245 | "contiguous\n", sort_list[i].segment_name, | |
246 | sort_list[i+1].segment_name); | |
b2300b9e HY |
247 | rc = -EINVAL; |
248 | goto out; | |
249 | } | |
250 | /* EN and EW are allowed in a block device */ | |
251 | if (sort_list[i].segment_type != sort_list[i+1].segment_type) { | |
252 | if (!(sort_list[i].segment_type & SEGMENT_EXCLUSIVE) || | |
253 | (sort_list[i].segment_type == SEG_TYPE_ER) || | |
254 | !(sort_list[i+1].segment_type & | |
255 | SEGMENT_EXCLUSIVE) || | |
256 | (sort_list[i+1].segment_type == SEG_TYPE_ER)) { | |
93098bf0 HY |
257 | pr_err("DCSS %s and DCSS %s have " |
258 | "incompatible types\n", | |
259 | sort_list[i].segment_name, | |
260 | sort_list[i+1].segment_name); | |
b2300b9e HY |
261 | rc = -EINVAL; |
262 | goto out; | |
263 | } | |
264 | } | |
265 | } | |
266 | rc = 0; | |
267 | out: | |
268 | kfree(sort_list); | |
269 | return rc; | |
270 | } | |
271 | ||
272 | /* | |
273 | * Load a segment | |
274 | */ | |
275 | static int | |
276 | dcssblk_load_segment(char *name, struct segment_info **seg_info) | |
277 | { | |
278 | int rc; | |
279 | ||
280 | /* already loaded? */ | |
281 | down_read(&dcssblk_devices_sem); | |
282 | *seg_info = dcssblk_get_segment_by_name(name); | |
283 | up_read(&dcssblk_devices_sem); | |
284 | if (*seg_info != NULL) | |
285 | return -EEXIST; | |
286 | ||
287 | /* get a struct segment_info */ | |
288 | *seg_info = kzalloc(sizeof(struct segment_info), GFP_KERNEL); | |
289 | if (*seg_info == NULL) | |
290 | return -ENOMEM; | |
291 | ||
292 | strcpy((*seg_info)->segment_name, name); | |
293 | ||
294 | /* load the segment */ | |
295 | rc = segment_load(name, SEGMENT_SHARED, | |
296 | &(*seg_info)->start, &(*seg_info)->end); | |
297 | if (rc < 0) { | |
298 | segment_warning(rc, (*seg_info)->segment_name); | |
299 | kfree(*seg_info); | |
300 | } else { | |
301 | INIT_LIST_HEAD(&(*seg_info)->lh); | |
302 | (*seg_info)->segment_type = rc; | |
303 | } | |
304 | return rc; | |
305 | } | |
306 | ||
931bb68b GS |
307 | static void dcssblk_unregister_callback(struct device *dev) |
308 | { | |
309 | device_unregister(dev); | |
310 | put_device(dev); | |
311 | } | |
312 | ||
1da177e4 LT |
313 | /* |
314 | * device attribute for switching shared/nonshared (exclusive) | |
315 | * operation (show + store) | |
316 | */ | |
317 | static ssize_t | |
e404e274 | 318 | dcssblk_shared_show(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
319 | { |
320 | struct dcssblk_dev_info *dev_info; | |
321 | ||
322 | dev_info = container_of(dev, struct dcssblk_dev_info, dev); | |
323 | return sprintf(buf, dev_info->is_shared ? "1\n" : "0\n"); | |
324 | } | |
325 | ||
326 | static ssize_t | |
e404e274 | 327 | dcssblk_shared_store(struct device *dev, struct device_attribute *attr, const char *inbuf, size_t count) |
1da177e4 LT |
328 | { |
329 | struct dcssblk_dev_info *dev_info; | |
b2300b9e | 330 | struct segment_info *entry, *temp; |
1da177e4 LT |
331 | int rc; |
332 | ||
ded77fb4 | 333 | if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0')) |
1da177e4 | 334 | return -EINVAL; |
1da177e4 LT |
335 | down_write(&dcssblk_devices_sem); |
336 | dev_info = container_of(dev, struct dcssblk_dev_info, dev); | |
337 | if (atomic_read(&dev_info->use_count)) { | |
1da177e4 LT |
338 | rc = -EBUSY; |
339 | goto out; | |
340 | } | |
341 | if (inbuf[0] == '1') { | |
b2300b9e HY |
342 | /* reload segments in shared mode */ |
343 | list_for_each_entry(entry, &dev_info->seg_list, lh) { | |
344 | rc = segment_modify_shared(entry->segment_name, | |
345 | SEGMENT_SHARED); | |
346 | if (rc < 0) { | |
347 | BUG_ON(rc == -EINVAL); | |
348 | if (rc != -EAGAIN) | |
349 | goto removeseg; | |
1da177e4 LT |
350 | } |
351 | } | |
b2300b9e HY |
352 | dev_info->is_shared = 1; |
353 | switch (dev_info->segment_type) { | |
354 | case SEG_TYPE_SR: | |
355 | case SEG_TYPE_ER: | |
356 | case SEG_TYPE_SC: | |
357 | set_disk_ro(dev_info->gd, 1); | |
358 | } | |
1da177e4 | 359 | } else if (inbuf[0] == '0') { |
b2300b9e | 360 | /* reload segments in exclusive mode */ |
1da177e4 | 361 | if (dev_info->segment_type == SEG_TYPE_SC) { |
93098bf0 HY |
362 | pr_err("DCSS %s is of type SC and cannot be " |
363 | "loaded as exclusive-writable\n", | |
364 | dev_info->segment_name); | |
1da177e4 LT |
365 | rc = -EINVAL; |
366 | goto out; | |
367 | } | |
b2300b9e HY |
368 | list_for_each_entry(entry, &dev_info->seg_list, lh) { |
369 | rc = segment_modify_shared(entry->segment_name, | |
370 | SEGMENT_EXCLUSIVE); | |
371 | if (rc < 0) { | |
372 | BUG_ON(rc == -EINVAL); | |
373 | if (rc != -EAGAIN) | |
374 | goto removeseg; | |
375 | } | |
1da177e4 | 376 | } |
b2300b9e HY |
377 | dev_info->is_shared = 0; |
378 | set_disk_ro(dev_info->gd, 0); | |
1da177e4 | 379 | } else { |
1da177e4 LT |
380 | rc = -EINVAL; |
381 | goto out; | |
382 | } | |
383 | rc = count; | |
384 | goto out; | |
385 | ||
386 | removeseg: | |
93098bf0 HY |
387 | pr_err("DCSS device %s is removed after a failed access mode " |
388 | "change\n", dev_info->segment_name); | |
b2300b9e HY |
389 | temp = entry; |
390 | list_for_each_entry(entry, &dev_info->seg_list, lh) { | |
391 | if (entry != temp) | |
392 | segment_unload(entry->segment_name); | |
393 | } | |
1da177e4 LT |
394 | list_del(&dev_info->lh); |
395 | ||
396 | del_gendisk(dev_info->gd); | |
1312f40e | 397 | blk_cleanup_queue(dev_info->dcssblk_queue); |
1da177e4 LT |
398 | dev_info->gd->queue = NULL; |
399 | put_disk(dev_info->gd); | |
931bb68b | 400 | rc = device_schedule_callback(dev, dcssblk_unregister_callback); |
1da177e4 LT |
401 | out: |
402 | up_write(&dcssblk_devices_sem); | |
403 | return rc; | |
404 | } | |
521b3d79 SO |
405 | static DEVICE_ATTR(shared, S_IWUSR | S_IRUSR, dcssblk_shared_show, |
406 | dcssblk_shared_store); | |
1da177e4 LT |
407 | |
408 | /* | |
409 | * device attribute for save operation on current copy | |
410 | * of the segment. If the segment is busy, saving will | |
411 | * become pending until it gets released, which can be | |
412 | * undone by storing a non-true value to this entry. | |
413 | * (show + store) | |
414 | */ | |
415 | static ssize_t | |
e404e274 | 416 | dcssblk_save_show(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
417 | { |
418 | struct dcssblk_dev_info *dev_info; | |
419 | ||
420 | dev_info = container_of(dev, struct dcssblk_dev_info, dev); | |
421 | return sprintf(buf, dev_info->save_pending ? "1\n" : "0\n"); | |
422 | } | |
423 | ||
424 | static ssize_t | |
e404e274 | 425 | dcssblk_save_store(struct device *dev, struct device_attribute *attr, const char *inbuf, size_t count) |
1da177e4 LT |
426 | { |
427 | struct dcssblk_dev_info *dev_info; | |
b2300b9e | 428 | struct segment_info *entry; |
1da177e4 | 429 | |
ded77fb4 | 430 | if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0')) |
1da177e4 | 431 | return -EINVAL; |
1da177e4 LT |
432 | dev_info = container_of(dev, struct dcssblk_dev_info, dev); |
433 | ||
434 | down_write(&dcssblk_devices_sem); | |
435 | if (inbuf[0] == '1') { | |
436 | if (atomic_read(&dev_info->use_count) == 0) { | |
437 | // device is idle => we save immediately | |
93098bf0 HY |
438 | pr_info("All DCSSs that map to device %s are " |
439 | "saved\n", dev_info->segment_name); | |
b2300b9e HY |
440 | list_for_each_entry(entry, &dev_info->seg_list, lh) { |
441 | segment_save(entry->segment_name); | |
442 | } | |
1da177e4 LT |
443 | } else { |
444 | // device is busy => we save it when it becomes | |
445 | // idle in dcssblk_release | |
93098bf0 HY |
446 | pr_info("Device %s is in use, its DCSSs will be " |
447 | "saved when it becomes idle\n", | |
448 | dev_info->segment_name); | |
1da177e4 LT |
449 | dev_info->save_pending = 1; |
450 | } | |
451 | } else if (inbuf[0] == '0') { | |
452 | if (dev_info->save_pending) { | |
453 | // device is busy & the user wants to undo his save | |
454 | // request | |
455 | dev_info->save_pending = 0; | |
93098bf0 HY |
456 | pr_info("A pending save request for device %s " |
457 | "has been canceled\n", | |
458 | dev_info->segment_name); | |
1da177e4 LT |
459 | } |
460 | } else { | |
461 | up_write(&dcssblk_devices_sem); | |
1da177e4 LT |
462 | return -EINVAL; |
463 | } | |
464 | up_write(&dcssblk_devices_sem); | |
465 | return count; | |
466 | } | |
521b3d79 SO |
467 | static DEVICE_ATTR(save, S_IWUSR | S_IRUSR, dcssblk_save_show, |
468 | dcssblk_save_store); | |
1da177e4 | 469 | |
b2300b9e HY |
470 | /* |
471 | * device attribute for showing all segments in a device | |
472 | */ | |
473 | static ssize_t | |
474 | dcssblk_seglist_show(struct device *dev, struct device_attribute *attr, | |
475 | char *buf) | |
476 | { | |
477 | int i; | |
478 | ||
479 | struct dcssblk_dev_info *dev_info; | |
480 | struct segment_info *entry; | |
481 | ||
482 | down_read(&dcssblk_devices_sem); | |
483 | dev_info = container_of(dev, struct dcssblk_dev_info, dev); | |
484 | i = 0; | |
485 | buf[0] = '\0'; | |
486 | list_for_each_entry(entry, &dev_info->seg_list, lh) { | |
487 | strcpy(&buf[i], entry->segment_name); | |
488 | i += strlen(entry->segment_name); | |
489 | buf[i] = '\n'; | |
490 | i++; | |
491 | } | |
492 | up_read(&dcssblk_devices_sem); | |
493 | return i; | |
494 | } | |
521b3d79 SO |
495 | static DEVICE_ATTR(seglist, S_IRUSR, dcssblk_seglist_show, NULL); |
496 | ||
497 | static struct attribute *dcssblk_dev_attrs[] = { | |
498 | &dev_attr_shared.attr, | |
499 | &dev_attr_save.attr, | |
500 | &dev_attr_seglist.attr, | |
501 | NULL, | |
502 | }; | |
503 | static struct attribute_group dcssblk_dev_attr_group = { | |
504 | .attrs = dcssblk_dev_attrs, | |
505 | }; | |
506 | static const struct attribute_group *dcssblk_dev_attr_groups[] = { | |
507 | &dcssblk_dev_attr_group, | |
508 | NULL, | |
509 | }; | |
b2300b9e | 510 | |
1da177e4 LT |
511 | /* |
512 | * device attribute for adding devices | |
513 | */ | |
514 | static ssize_t | |
e404e274 | 515 | dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
1da177e4 | 516 | { |
b2300b9e | 517 | int rc, i, j, num_of_segments; |
1da177e4 | 518 | struct dcssblk_dev_info *dev_info; |
b2300b9e | 519 | struct segment_info *seg_info, *temp; |
1da177e4 LT |
520 | char *local_buf; |
521 | unsigned long seg_byte_size; | |
522 | ||
523 | dev_info = NULL; | |
b2300b9e | 524 | seg_info = NULL; |
1da177e4 LT |
525 | if (dev != dcssblk_root_dev) { |
526 | rc = -EINVAL; | |
527 | goto out_nobuf; | |
528 | } | |
b2300b9e HY |
529 | if ((count < 1) || (buf[0] == '\0') || (buf[0] == '\n')) { |
530 | rc = -ENAMETOOLONG; | |
531 | goto out_nobuf; | |
532 | } | |
533 | ||
1da177e4 LT |
534 | local_buf = kmalloc(count + 1, GFP_KERNEL); |
535 | if (local_buf == NULL) { | |
536 | rc = -ENOMEM; | |
537 | goto out_nobuf; | |
538 | } | |
b2300b9e | 539 | |
1da177e4 LT |
540 | /* |
541 | * parse input | |
542 | */ | |
b2300b9e | 543 | num_of_segments = 0; |
1da177e4 | 544 | for (i = 0; ((buf[i] != '\0') && (buf[i] != '\n') && i < count); i++) { |
b2300b9e HY |
545 | for (j = i; (buf[j] != ':') && |
546 | (buf[j] != '\0') && | |
547 | (buf[j] != '\n') && | |
548 | j < count; j++) { | |
549 | local_buf[j-i] = toupper(buf[j]); | |
550 | } | |
551 | local_buf[j-i] = '\0'; | |
552 | if (((j - i) == 0) || ((j - i) > 8)) { | |
553 | rc = -ENAMETOOLONG; | |
554 | goto seg_list_del; | |
555 | } | |
556 | ||
557 | rc = dcssblk_load_segment(local_buf, &seg_info); | |
558 | if (rc < 0) | |
559 | goto seg_list_del; | |
560 | /* | |
561 | * get a struct dcssblk_dev_info | |
562 | */ | |
563 | if (num_of_segments == 0) { | |
564 | dev_info = kzalloc(sizeof(struct dcssblk_dev_info), | |
565 | GFP_KERNEL); | |
566 | if (dev_info == NULL) { | |
567 | rc = -ENOMEM; | |
568 | goto out; | |
569 | } | |
570 | strcpy(dev_info->segment_name, local_buf); | |
571 | dev_info->segment_type = seg_info->segment_type; | |
572 | INIT_LIST_HEAD(&dev_info->seg_list); | |
573 | } | |
574 | list_add_tail(&seg_info->lh, &dev_info->seg_list); | |
575 | num_of_segments++; | |
576 | i = j; | |
577 | ||
578 | if ((buf[j] == '\0') || (buf[j] == '\n')) | |
579 | break; | |
1da177e4 | 580 | } |
b2300b9e HY |
581 | |
582 | /* no trailing colon at the end of the input */ | |
583 | if ((i > 0) && (buf[i-1] == ':')) { | |
1da177e4 | 584 | rc = -ENAMETOOLONG; |
b2300b9e | 585 | goto seg_list_del; |
1da177e4 | 586 | } |
b2300b9e HY |
587 | strlcpy(local_buf, buf, i + 1); |
588 | dev_info->num_of_segments = num_of_segments; | |
589 | rc = dcssblk_is_continuous(dev_info); | |
590 | if (rc < 0) | |
591 | goto seg_list_del; | |
592 | ||
593 | dev_info->start = dcssblk_find_lowest_addr(dev_info); | |
594 | dev_info->end = dcssblk_find_highest_addr(dev_info); | |
1da177e4 | 595 | |
b2300b9e | 596 | dev_set_name(&dev_info->dev, dev_info->segment_name); |
1da177e4 | 597 | dev_info->dev.release = dcssblk_release_segment; |
521b3d79 | 598 | dev_info->dev.groups = dcssblk_dev_attr_groups; |
1da177e4 | 599 | INIT_LIST_HEAD(&dev_info->lh); |
1da177e4 LT |
600 | dev_info->gd = alloc_disk(DCSSBLK_MINORS_PER_DISK); |
601 | if (dev_info->gd == NULL) { | |
602 | rc = -ENOMEM; | |
b2300b9e | 603 | goto seg_list_del; |
1da177e4 LT |
604 | } |
605 | dev_info->gd->major = dcssblk_major; | |
606 | dev_info->gd->fops = &dcssblk_devops; | |
607 | dev_info->dcssblk_queue = blk_alloc_queue(GFP_KERNEL); | |
608 | dev_info->gd->queue = dev_info->dcssblk_queue; | |
609 | dev_info->gd->private_data = dev_info; | |
610 | dev_info->gd->driverfs_dev = &dev_info->dev; | |
c5411dba | 611 | blk_queue_make_request(dev_info->dcssblk_queue, dcssblk_make_request); |
e1defc4f | 612 | blk_queue_logical_block_size(dev_info->dcssblk_queue, 4096); |
b2300b9e | 613 | |
1da177e4 LT |
614 | seg_byte_size = (dev_info->end - dev_info->start + 1); |
615 | set_capacity(dev_info->gd, seg_byte_size >> 9); // size in sectors | |
93098bf0 HY |
616 | pr_info("Loaded %s with total size %lu bytes and capacity %lu " |
617 | "sectors\n", local_buf, seg_byte_size, seg_byte_size >> 9); | |
1da177e4 | 618 | |
1da177e4 LT |
619 | dev_info->save_pending = 0; |
620 | dev_info->is_shared = 1; | |
621 | dev_info->dev.parent = dcssblk_root_dev; | |
622 | ||
623 | /* | |
b2300b9e | 624 | *get minor, add to list |
1da177e4 LT |
625 | */ |
626 | down_write(&dcssblk_devices_sem); | |
b2300b9e | 627 | if (dcssblk_get_segment_by_name(local_buf)) { |
04f64b57 | 628 | rc = -EEXIST; |
b2300b9e | 629 | goto release_gd; |
04f64b57 | 630 | } |
1da177e4 | 631 | rc = dcssblk_assign_free_minor(dev_info); |
b2300b9e HY |
632 | if (rc) |
633 | goto release_gd; | |
1da177e4 | 634 | sprintf(dev_info->gd->disk_name, "dcssblk%d", |
d0591485 | 635 | dev_info->gd->first_minor); |
1da177e4 LT |
636 | list_add_tail(&dev_info->lh, &dcssblk_devices); |
637 | ||
638 | if (!try_module_get(THIS_MODULE)) { | |
639 | rc = -ENODEV; | |
b2300b9e | 640 | goto dev_list_del; |
1da177e4 LT |
641 | } |
642 | /* | |
643 | * register the device | |
644 | */ | |
645 | rc = device_register(&dev_info->dev); | |
b2300b9e | 646 | if (rc) |
521b3d79 | 647 | goto put_dev; |
1da177e4 | 648 | |
521b3d79 | 649 | get_device(&dev_info->dev); |
436d1bc7 CB |
650 | add_disk(dev_info->gd); |
651 | ||
1da177e4 LT |
652 | switch (dev_info->segment_type) { |
653 | case SEG_TYPE_SR: | |
654 | case SEG_TYPE_ER: | |
655 | case SEG_TYPE_SC: | |
656 | set_disk_ro(dev_info->gd,1); | |
657 | break; | |
658 | default: | |
659 | set_disk_ro(dev_info->gd,0); | |
660 | break; | |
661 | } | |
1da177e4 LT |
662 | up_write(&dcssblk_devices_sem); |
663 | rc = count; | |
664 | goto out; | |
665 | ||
521b3d79 | 666 | put_dev: |
1da177e4 | 667 | list_del(&dev_info->lh); |
1312f40e | 668 | blk_cleanup_queue(dev_info->dcssblk_queue); |
1da177e4 LT |
669 | dev_info->gd->queue = NULL; |
670 | put_disk(dev_info->gd); | |
b2300b9e HY |
671 | list_for_each_entry(seg_info, &dev_info->seg_list, lh) { |
672 | segment_unload(seg_info->segment_name); | |
673 | } | |
1da177e4 LT |
674 | put_device(&dev_info->dev); |
675 | up_write(&dcssblk_devices_sem); | |
676 | goto out; | |
b2300b9e | 677 | dev_list_del: |
1da177e4 | 678 | list_del(&dev_info->lh); |
b2300b9e | 679 | release_gd: |
1312f40e | 680 | blk_cleanup_queue(dev_info->dcssblk_queue); |
1da177e4 LT |
681 | dev_info->gd->queue = NULL; |
682 | put_disk(dev_info->gd); | |
b2300b9e HY |
683 | up_write(&dcssblk_devices_sem); |
684 | seg_list_del: | |
685 | if (dev_info == NULL) | |
686 | goto out; | |
687 | list_for_each_entry_safe(seg_info, temp, &dev_info->seg_list, lh) { | |
688 | list_del(&seg_info->lh); | |
689 | segment_unload(seg_info->segment_name); | |
690 | kfree(seg_info); | |
691 | } | |
1da177e4 LT |
692 | kfree(dev_info); |
693 | out: | |
694 | kfree(local_buf); | |
695 | out_nobuf: | |
696 | return rc; | |
697 | } | |
698 | ||
699 | /* | |
700 | * device attribute for removing devices | |
701 | */ | |
702 | static ssize_t | |
e404e274 | 703 | dcssblk_remove_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
1da177e4 LT |
704 | { |
705 | struct dcssblk_dev_info *dev_info; | |
b2300b9e | 706 | struct segment_info *entry; |
1da177e4 LT |
707 | int rc, i; |
708 | char *local_buf; | |
709 | ||
710 | if (dev != dcssblk_root_dev) { | |
711 | return -EINVAL; | |
712 | } | |
713 | local_buf = kmalloc(count + 1, GFP_KERNEL); | |
714 | if (local_buf == NULL) { | |
715 | return -ENOMEM; | |
716 | } | |
717 | /* | |
718 | * parse input | |
719 | */ | |
720 | for (i = 0; ((*(buf+i)!='\0') && (*(buf+i)!='\n') && i < count); i++) { | |
721 | local_buf[i] = toupper(buf[i]); | |
722 | } | |
723 | local_buf[i] = '\0'; | |
724 | if ((i == 0) || (i > 8)) { | |
725 | rc = -ENAMETOOLONG; | |
726 | goto out_buf; | |
727 | } | |
728 | ||
729 | down_write(&dcssblk_devices_sem); | |
730 | dev_info = dcssblk_get_device_by_name(local_buf); | |
731 | if (dev_info == NULL) { | |
732 | up_write(&dcssblk_devices_sem); | |
93098bf0 HY |
733 | pr_warning("Device %s cannot be removed because it is not a " |
734 | "known device\n", local_buf); | |
1da177e4 LT |
735 | rc = -ENODEV; |
736 | goto out_buf; | |
737 | } | |
738 | if (atomic_read(&dev_info->use_count) != 0) { | |
739 | up_write(&dcssblk_devices_sem); | |
93098bf0 HY |
740 | pr_warning("Device %s cannot be removed while it is in " |
741 | "use\n", local_buf); | |
1da177e4 LT |
742 | rc = -EBUSY; |
743 | goto out_buf; | |
744 | } | |
1da177e4 | 745 | |
b2300b9e | 746 | list_del(&dev_info->lh); |
1da177e4 | 747 | del_gendisk(dev_info->gd); |
1312f40e | 748 | blk_cleanup_queue(dev_info->dcssblk_queue); |
1da177e4 LT |
749 | dev_info->gd->queue = NULL; |
750 | put_disk(dev_info->gd); | |
751 | device_unregister(&dev_info->dev); | |
b2300b9e HY |
752 | |
753 | /* unload all related segments */ | |
754 | list_for_each_entry(entry, &dev_info->seg_list, lh) | |
755 | segment_unload(entry->segment_name); | |
756 | ||
1da177e4 LT |
757 | put_device(&dev_info->dev); |
758 | up_write(&dcssblk_devices_sem); | |
759 | ||
760 | rc = count; | |
761 | out_buf: | |
762 | kfree(local_buf); | |
763 | return rc; | |
764 | } | |
765 | ||
766 | static int | |
46d74326 | 767 | dcssblk_open(struct block_device *bdev, fmode_t mode) |
1da177e4 LT |
768 | { |
769 | struct dcssblk_dev_info *dev_info; | |
770 | int rc; | |
771 | ||
46d74326 | 772 | dev_info = bdev->bd_disk->private_data; |
1da177e4 LT |
773 | if (NULL == dev_info) { |
774 | rc = -ENODEV; | |
775 | goto out; | |
776 | } | |
777 | atomic_inc(&dev_info->use_count); | |
46d74326 | 778 | bdev->bd_block_size = 4096; |
1da177e4 LT |
779 | rc = 0; |
780 | out: | |
781 | return rc; | |
782 | } | |
783 | ||
db2a144b | 784 | static void |
46d74326 | 785 | dcssblk_release(struct gendisk *disk, fmode_t mode) |
1da177e4 | 786 | { |
46d74326 | 787 | struct dcssblk_dev_info *dev_info = disk->private_data; |
b2300b9e | 788 | struct segment_info *entry; |
1da177e4 | 789 | |
46d74326 | 790 | if (!dev_info) { |
db2a144b AV |
791 | WARN_ON(1); |
792 | return; | |
1da177e4 LT |
793 | } |
794 | down_write(&dcssblk_devices_sem); | |
795 | if (atomic_dec_and_test(&dev_info->use_count) | |
796 | && (dev_info->save_pending)) { | |
93098bf0 HY |
797 | pr_info("Device %s has become idle and is being saved " |
798 | "now\n", dev_info->segment_name); | |
b2300b9e HY |
799 | list_for_each_entry(entry, &dev_info->seg_list, lh) { |
800 | segment_save(entry->segment_name); | |
801 | } | |
1da177e4 LT |
802 | dev_info->save_pending = 0; |
803 | } | |
804 | up_write(&dcssblk_devices_sem); | |
1da177e4 LT |
805 | } |
806 | ||
5a7bbad2 | 807 | static void |
165125e1 | 808 | dcssblk_make_request(struct request_queue *q, struct bio *bio) |
1da177e4 LT |
809 | { |
810 | struct dcssblk_dev_info *dev_info; | |
811 | struct bio_vec *bvec; | |
812 | unsigned long index; | |
813 | unsigned long page_addr; | |
814 | unsigned long source_addr; | |
815 | unsigned long bytes_done; | |
816 | int i; | |
817 | ||
818 | bytes_done = 0; | |
819 | dev_info = bio->bi_bdev->bd_disk->private_data; | |
820 | if (dev_info == NULL) | |
821 | goto fail; | |
822 | if ((bio->bi_sector & 7) != 0 || (bio->bi_size & 4095) != 0) | |
823 | /* Request is not page-aligned. */ | |
824 | goto fail; | |
f73a1c7d | 825 | if (bio_end_sector(bio) > get_capacity(bio->bi_bdev->bd_disk)) { |
1da177e4 LT |
826 | /* Request beyond end of DCSS segment. */ |
827 | goto fail; | |
828 | } | |
420edbcc CO |
829 | /* verify data transfer direction */ |
830 | if (dev_info->is_shared) { | |
831 | switch (dev_info->segment_type) { | |
832 | case SEG_TYPE_SR: | |
833 | case SEG_TYPE_ER: | |
834 | case SEG_TYPE_SC: | |
835 | /* cannot write to these segments */ | |
836 | if (bio_data_dir(bio) == WRITE) { | |
93098bf0 HY |
837 | pr_warning("Writing to %s failed because it " |
838 | "is a read-only device\n", | |
2a0217d5 | 839 | dev_name(&dev_info->dev)); |
420edbcc CO |
840 | goto fail; |
841 | } | |
842 | } | |
843 | } | |
844 | ||
1da177e4 LT |
845 | index = (bio->bi_sector >> 3); |
846 | bio_for_each_segment(bvec, bio, i) { | |
847 | page_addr = (unsigned long) | |
848 | page_address(bvec->bv_page) + bvec->bv_offset; | |
849 | source_addr = dev_info->start + (index<<12) + bytes_done; | |
39f73b28 | 850 | if (unlikely((page_addr & 4095) != 0) || (bvec->bv_len & 4095) != 0) |
1da177e4 LT |
851 | // More paranoia. |
852 | goto fail; | |
853 | if (bio_data_dir(bio) == READ) { | |
854 | memcpy((void*)page_addr, (void*)source_addr, | |
855 | bvec->bv_len); | |
856 | } else { | |
857 | memcpy((void*)source_addr, (void*)page_addr, | |
858 | bvec->bv_len); | |
859 | } | |
860 | bytes_done += bvec->bv_len; | |
861 | } | |
6712ecf8 | 862 | bio_endio(bio, 0); |
5a7bbad2 | 863 | return; |
1da177e4 | 864 | fail: |
6712ecf8 | 865 | bio_io_error(bio); |
420edbcc CO |
866 | } |
867 | ||
868 | static int | |
869 | dcssblk_direct_access (struct block_device *bdev, sector_t secnum, | |
30afcb4b | 870 | void **kaddr, unsigned long *pfn) |
420edbcc CO |
871 | { |
872 | struct dcssblk_dev_info *dev_info; | |
873 | unsigned long pgoff; | |
874 | ||
875 | dev_info = bdev->bd_disk->private_data; | |
876 | if (!dev_info) | |
877 | return -ENODEV; | |
878 | if (secnum % (PAGE_SIZE/512)) | |
879 | return -EINVAL; | |
880 | pgoff = secnum / (PAGE_SIZE / 512); | |
881 | if ((pgoff+1)*PAGE_SIZE-1 > dev_info->end - dev_info->start) | |
882 | return -ERANGE; | |
30afcb4b JH |
883 | *kaddr = (void *) (dev_info->start+pgoff*PAGE_SIZE); |
884 | *pfn = virt_to_phys(*kaddr) >> PAGE_SHIFT; | |
885 | ||
1da177e4 LT |
886 | return 0; |
887 | } | |
888 | ||
889 | static void | |
890 | dcssblk_check_params(void) | |
891 | { | |
892 | int rc, i, j, k; | |
b2300b9e | 893 | char buf[DCSSBLK_PARM_LEN + 1]; |
1da177e4 LT |
894 | struct dcssblk_dev_info *dev_info; |
895 | ||
896 | for (i = 0; (i < DCSSBLK_PARM_LEN) && (dcssblk_segments[i] != '\0'); | |
897 | i++) { | |
898 | for (j = i; (dcssblk_segments[j] != ',') && | |
899 | (dcssblk_segments[j] != '\0') && | |
900 | (dcssblk_segments[j] != '(') && | |
b2300b9e | 901 | (j < DCSSBLK_PARM_LEN); j++) |
1da177e4 LT |
902 | { |
903 | buf[j-i] = dcssblk_segments[j]; | |
904 | } | |
905 | buf[j-i] = '\0'; | |
f901e5d1 | 906 | rc = dcssblk_add_store(dcssblk_root_dev, NULL, buf, j-i); |
1da177e4 | 907 | if ((rc >= 0) && (dcssblk_segments[j] == '(')) { |
b2300b9e | 908 | for (k = 0; (buf[k] != ':') && (buf[k] != '\0'); k++) |
1da177e4 | 909 | buf[k] = toupper(buf[k]); |
b2300b9e | 910 | buf[k] = '\0'; |
1da177e4 LT |
911 | if (!strncmp(&dcssblk_segments[j], "(local)", 7)) { |
912 | down_read(&dcssblk_devices_sem); | |
913 | dev_info = dcssblk_get_device_by_name(buf); | |
914 | up_read(&dcssblk_devices_sem); | |
915 | if (dev_info) | |
916 | dcssblk_shared_store(&dev_info->dev, | |
f901e5d1 | 917 | NULL, "0\n", 2); |
1da177e4 LT |
918 | } |
919 | } | |
920 | while ((dcssblk_segments[j] != ',') && | |
921 | (dcssblk_segments[j] != '\0')) | |
922 | { | |
923 | j++; | |
924 | } | |
925 | if (dcssblk_segments[j] == '\0') | |
926 | break; | |
927 | i = j; | |
928 | } | |
929 | } | |
930 | ||
c369527f GS |
931 | /* |
932 | * Suspend / Resume | |
933 | */ | |
934 | static int dcssblk_freeze(struct device *dev) | |
935 | { | |
936 | struct dcssblk_dev_info *dev_info; | |
937 | int rc = 0; | |
938 | ||
939 | list_for_each_entry(dev_info, &dcssblk_devices, lh) { | |
940 | switch (dev_info->segment_type) { | |
941 | case SEG_TYPE_SR: | |
942 | case SEG_TYPE_ER: | |
943 | case SEG_TYPE_SC: | |
944 | if (!dev_info->is_shared) | |
945 | rc = -EINVAL; | |
946 | break; | |
947 | default: | |
948 | rc = -EINVAL; | |
949 | break; | |
950 | } | |
951 | if (rc) | |
952 | break; | |
953 | } | |
954 | if (rc) | |
2c48c4d6 CB |
955 | pr_err("Suspending the system failed because DCSS device %s " |
956 | "is writable\n", | |
c369527f GS |
957 | dev_info->segment_name); |
958 | return rc; | |
959 | } | |
960 | ||
961 | static int dcssblk_restore(struct device *dev) | |
962 | { | |
963 | struct dcssblk_dev_info *dev_info; | |
964 | struct segment_info *entry; | |
965 | unsigned long start, end; | |
966 | int rc = 0; | |
967 | ||
968 | list_for_each_entry(dev_info, &dcssblk_devices, lh) { | |
969 | list_for_each_entry(entry, &dev_info->seg_list, lh) { | |
970 | segment_unload(entry->segment_name); | |
971 | rc = segment_load(entry->segment_name, SEGMENT_SHARED, | |
972 | &start, &end); | |
973 | if (rc < 0) { | |
974 | // TODO in_use check ? | |
975 | segment_warning(rc, entry->segment_name); | |
976 | goto out_panic; | |
977 | } | |
978 | if (start != entry->start || end != entry->end) { | |
2c48c4d6 CB |
979 | pr_err("The address range of DCSS %s changed " |
980 | "while the system was suspended\n", | |
c369527f GS |
981 | entry->segment_name); |
982 | goto out_panic; | |
983 | } | |
984 | } | |
985 | } | |
986 | return 0; | |
987 | out_panic: | |
988 | panic("fatal dcssblk resume error\n"); | |
989 | } | |
990 | ||
991 | static int dcssblk_thaw(struct device *dev) | |
992 | { | |
993 | return 0; | |
994 | } | |
995 | ||
47145210 | 996 | static const struct dev_pm_ops dcssblk_pm_ops = { |
c369527f GS |
997 | .freeze = dcssblk_freeze, |
998 | .thaw = dcssblk_thaw, | |
999 | .restore = dcssblk_restore, | |
1000 | }; | |
1001 | ||
1002 | static struct platform_driver dcssblk_pdrv = { | |
1003 | .driver = { | |
1004 | .name = "dcssblk", | |
1005 | .owner = THIS_MODULE, | |
1006 | .pm = &dcssblk_pm_ops, | |
1007 | }, | |
1008 | }; | |
1009 | ||
1010 | static struct platform_device *dcssblk_pdev; | |
1011 | ||
1012 | ||
1da177e4 LT |
1013 | /* |
1014 | * The init/exit functions. | |
1015 | */ | |
1016 | static void __exit | |
1017 | dcssblk_exit(void) | |
1018 | { | |
c369527f GS |
1019 | platform_device_unregister(dcssblk_pdev); |
1020 | platform_driver_unregister(&dcssblk_pdrv); | |
035da16f | 1021 | root_device_unregister(dcssblk_root_dev); |
00d59405 | 1022 | unregister_blkdev(dcssblk_major, DCSSBLK_NAME); |
1da177e4 LT |
1023 | } |
1024 | ||
1025 | static int __init | |
1026 | dcssblk_init(void) | |
1027 | { | |
1028 | int rc; | |
1029 | ||
c369527f GS |
1030 | rc = platform_driver_register(&dcssblk_pdrv); |
1031 | if (rc) | |
1da177e4 | 1032 | return rc; |
c369527f GS |
1033 | |
1034 | dcssblk_pdev = platform_device_register_simple("dcssblk", -1, NULL, | |
1035 | 0); | |
1036 | if (IS_ERR(dcssblk_pdev)) { | |
1037 | rc = PTR_ERR(dcssblk_pdev); | |
1038 | goto out_pdrv; | |
1da177e4 | 1039 | } |
c369527f GS |
1040 | |
1041 | dcssblk_root_dev = root_device_register("dcssblk"); | |
1042 | if (IS_ERR(dcssblk_root_dev)) { | |
1043 | rc = PTR_ERR(dcssblk_root_dev); | |
1044 | goto out_pdev; | |
1da177e4 | 1045 | } |
c369527f GS |
1046 | rc = device_create_file(dcssblk_root_dev, &dev_attr_add); |
1047 | if (rc) | |
1048 | goto out_root; | |
1049 | rc = device_create_file(dcssblk_root_dev, &dev_attr_remove); | |
1050 | if (rc) | |
1051 | goto out_root; | |
1da177e4 | 1052 | rc = register_blkdev(0, DCSSBLK_NAME); |
c369527f GS |
1053 | if (rc < 0) |
1054 | goto out_root; | |
1da177e4 LT |
1055 | dcssblk_major = rc; |
1056 | init_rwsem(&dcssblk_devices_sem); | |
1057 | ||
1058 | dcssblk_check_params(); | |
1da177e4 | 1059 | return 0; |
c369527f GS |
1060 | |
1061 | out_root: | |
1062 | root_device_unregister(dcssblk_root_dev); | |
1063 | out_pdev: | |
1064 | platform_device_unregister(dcssblk_pdev); | |
1065 | out_pdrv: | |
1066 | platform_driver_unregister(&dcssblk_pdrv); | |
1067 | return rc; | |
1da177e4 LT |
1068 | } |
1069 | ||
1070 | module_init(dcssblk_init); | |
1071 | module_exit(dcssblk_exit); | |
1072 | ||
1073 | module_param_string(segments, dcssblk_segments, DCSSBLK_PARM_LEN, 0444); | |
1074 | MODULE_PARM_DESC(segments, "Name of DCSS segment(s) to be loaded, " | |
b2300b9e HY |
1075 | "comma-separated list, names in each set separated " |
1076 | "by commas are separated by colons, each set contains " | |
1077 | "names of contiguous segments and each name max. 8 chars.\n" | |
1078 | "Adding \"(local)\" to the end of each set equals echoing 0 " | |
1079 | "to /sys/devices/dcssblk/<device name>/shared after loading " | |
1080 | "the contiguous segments - \n" | |
1081 | "e.g. segments=\"mydcss1,mydcss2:mydcss3,mydcss4(local)\""); | |
1da177e4 LT |
1082 | |
1083 | MODULE_LICENSE("GPL"); |