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GUI: Fix Tomato RAF theme for all builds. Compilation typo.
[tomato.git] / release / src-rt-6.x.4708 / linux / linux-2.6.36 / drivers / s390 / block / dcssblk.c
blob2bd72aa34c59c2e6d62b418a06fe8fb8747d27bc
1 /*
2 * dcssblk.c -- the S/390 block driver for dcss memory
3 *
4 * Authors: Carsten Otte, Stefan Weinhuber, Gerald Schaefer
5 */
6
7 #define KMSG_COMPONENT "dcssblk"
8 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
9
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>
17 #include <linux/smp_lock.h>
18 #include <linux/completion.h>
19 #include <linux/interrupt.h>
20 #include <linux/platform_device.h>
21 #include <asm/extmem.h>
22 #include <asm/io.h>
23
24 #define DCSSBLK_NAME "dcssblk"
25 #define DCSSBLK_MINORS_PER_DISK 1
26 #define DCSSBLK_PARM_LEN 400
27 #define DCSS_BUS_ID_SIZE 20
28
29 static int dcssblk_open(struct block_device *bdev, fmode_t mode);
30 static int dcssblk_release(struct gendisk *disk, fmode_t mode);
31 static int dcssblk_make_request(struct request_queue *q, struct bio *bio);
32 static int dcssblk_direct_access(struct block_device *bdev, sector_t secnum,
33 void **kaddr, unsigned long *pfn);
34
35 static char dcssblk_segments[DCSSBLK_PARM_LEN] = "\0";
36
37 static int dcssblk_major;
38 static const struct block_device_operations dcssblk_devops = {
39 .owner = THIS_MODULE,
40 .open = dcssblk_open,
41 .release = dcssblk_release,
42 .direct_access = dcssblk_direct_access,
43 };
44
45 struct dcssblk_dev_info {
46 struct list_head lh;
47 struct device dev;
48 char segment_name[DCSS_BUS_ID_SIZE];
49 atomic_t use_count;
50 struct gendisk *gd;
51 unsigned long start;
52 unsigned long end;
53 int segment_type;
54 unsigned char save_pending;
55 unsigned char is_shared;
56 struct request_queue *dcssblk_queue;
57 int num_of_segments;
58 struct list_head seg_list;
59 };
60
61 struct segment_info {
62 struct list_head lh;
63 char segment_name[DCSS_BUS_ID_SIZE];
64 unsigned long start;
65 unsigned long end;
66 int segment_type;
67 };
68
69 static ssize_t dcssblk_add_store(struct device * dev, struct device_attribute *attr, const char * buf,
70 size_t count);
71 static ssize_t dcssblk_remove_store(struct device * dev, struct device_attribute *attr, const char * buf,
72 size_t count);
73 static ssize_t dcssblk_save_store(struct device * dev, struct device_attribute *attr, const char * buf,
74 size_t count);
75 static ssize_t dcssblk_save_show(struct device *dev, struct device_attribute *attr, char *buf);
76 static ssize_t dcssblk_shared_store(struct device * dev, struct device_attribute *attr, const char * buf,
77 size_t count);
78 static ssize_t dcssblk_shared_show(struct device *dev, struct device_attribute *attr, char *buf);
79 static ssize_t dcssblk_seglist_show(struct device *dev,
80 struct device_attribute *attr,
81 char *buf);
82
83 static DEVICE_ATTR(add, S_IWUSR, NULL, dcssblk_add_store);
84 static DEVICE_ATTR(remove, S_IWUSR, NULL, dcssblk_remove_store);
85 static DEVICE_ATTR(save, S_IWUSR | S_IRUSR, dcssblk_save_show,
86 dcssblk_save_store);
87 static DEVICE_ATTR(shared, S_IWUSR | S_IRUSR, dcssblk_shared_show,
88 dcssblk_shared_store);
89 static DEVICE_ATTR(seglist, S_IRUSR, dcssblk_seglist_show, NULL);
90
91 static struct device *dcssblk_root_dev;
92
93 static LIST_HEAD(dcssblk_devices);
94 static struct rw_semaphore dcssblk_devices_sem;
95
96 /*
97 * release function for segment device.
98 */
99 static void
100 dcssblk_release_segment(struct device *dev)
101 {
102 struct dcssblk_dev_info *dev_info;
103 struct segment_info *entry, *temp;
104
105 dev_info = container_of(dev, struct dcssblk_dev_info, dev);
106 list_for_each_entry_safe(entry, temp, &dev_info->seg_list, lh) {
107 list_del(&entry->lh);
108 kfree(entry);
109 }
110 kfree(dev_info);
111 module_put(THIS_MODULE);
112 }
113
114 /*
115 * get a minor number. needs to be called with
116 * down_write(&dcssblk_devices_sem) and the
117 * device needs to be enqueued before the semaphore is
118 * freed.
119 */
120 static int
121 dcssblk_assign_free_minor(struct dcssblk_dev_info *dev_info)
122 {
123 int minor, found;
124 struct dcssblk_dev_info *entry;
125
126 if (dev_info == NULL)
127 return -EINVAL;
128 for (minor = 0; minor < (1<<MINORBITS); minor++) {
129 found = 0;
130 // test if minor available
131 list_for_each_entry(entry, &dcssblk_devices, lh)
132 if (minor == entry->gd->first_minor)
133 found++;
134 if (!found) break; // got unused minor
135 }
136 if (found)
137 return -EBUSY;
138 dev_info->gd->first_minor = minor;
139 return 0;
140 }
141
142 /*
143 * get the struct dcssblk_dev_info from dcssblk_devices
144 * for the given name.
145 * down_read(&dcssblk_devices_sem) must be held.
146 */
147 static struct dcssblk_dev_info *
148 dcssblk_get_device_by_name(char *name)
149 {
150 struct dcssblk_dev_info *entry;
151
152 list_for_each_entry(entry, &dcssblk_devices, lh) {
153 if (!strcmp(name, entry->segment_name)) {
154 return entry;
155 }
156 }
157 return NULL;
158 }
159
160 /*
161 * get the struct segment_info from seg_list
162 * for the given name.
163 * down_read(&dcssblk_devices_sem) must be held.
164 */
165 static struct segment_info *
166 dcssblk_get_segment_by_name(char *name)
167 {
168 struct dcssblk_dev_info *dev_info;
169 struct segment_info *entry;
170
171 list_for_each_entry(dev_info, &dcssblk_devices, lh) {
172 list_for_each_entry(entry, &dev_info->seg_list, lh) {
173 if (!strcmp(name, entry->segment_name))
174 return entry;
175 }
176 }
177 return NULL;
178 }
179
180 /*
181 * get the highest address of the multi-segment block.
182 */
183 static unsigned long
184 dcssblk_find_highest_addr(struct dcssblk_dev_info *dev_info)
185 {
186 unsigned long highest_addr;
187 struct segment_info *entry;
188
189 highest_addr = 0;
190 list_for_each_entry(entry, &dev_info->seg_list, lh) {
191 if (highest_addr < entry->end)
192 highest_addr = entry->end;
193 }
194 return highest_addr;
195 }
196
197 /*
198 * get the lowest address of the multi-segment block.
199 */
200 static unsigned long
201 dcssblk_find_lowest_addr(struct dcssblk_dev_info *dev_info)
202 {
203 int set_first;
204 unsigned long lowest_addr;
205 struct segment_info *entry;
206
207 set_first = 0;
208 lowest_addr = 0;
209 list_for_each_entry(entry, &dev_info->seg_list, lh) {
210 if (set_first == 0) {
211 lowest_addr = entry->start;
212 set_first = 1;
213 } else {
214 if (lowest_addr > entry->start)
215 lowest_addr = entry->start;
216 }
217 }
218 return lowest_addr;
219 }
220
221 /*
222 * Check continuity of segments.
223 */
224 static int
225 dcssblk_is_continuous(struct dcssblk_dev_info *dev_info)
226 {
227 int i, j, rc;
228 struct segment_info *sort_list, *entry, temp;
229
230 if (dev_info->num_of_segments <= 1)
231 return 0;
232
233 sort_list = kzalloc(
234 sizeof(struct segment_info) * dev_info->num_of_segments,
235 GFP_KERNEL);
236 if (sort_list == NULL)
237 return -ENOMEM;
238 i = 0;
239 list_for_each_entry(entry, &dev_info->seg_list, lh) {
240 memcpy(&sort_list[i], entry, sizeof(struct segment_info));
241 i++;
242 }
243
244 /* sort segments */
245 for (i = 0; i < dev_info->num_of_segments; i++)
246 for (j = 0; j < dev_info->num_of_segments; j++)
247 if (sort_list[j].start > sort_list[i].start) {
248 memcpy(&temp, &sort_list[i],
249 sizeof(struct segment_info));
250 memcpy(&sort_list[i], &sort_list[j],
251 sizeof(struct segment_info));
252 memcpy(&sort_list[j], &temp,
253 sizeof(struct segment_info));
254 }
255
256 /* check continuity */
257 for (i = 0; i < dev_info->num_of_segments - 1; i++) {
258 if ((sort_list[i].end + 1) != sort_list[i+1].start) {
259 pr_err("Adjacent DCSSs %s and %s are not "
260 "contiguous\n", sort_list[i].segment_name,
261 sort_list[i+1].segment_name);
262 rc = -EINVAL;
263 goto out;
264 }
265 /* EN and EW are allowed in a block device */
266 if (sort_list[i].segment_type != sort_list[i+1].segment_type) {
267 if (!(sort_list[i].segment_type & SEGMENT_EXCLUSIVE) ||
268 (sort_list[i].segment_type == SEG_TYPE_ER) ||
269 !(sort_list[i+1].segment_type &
270 SEGMENT_EXCLUSIVE) ||
271 (sort_list[i+1].segment_type == SEG_TYPE_ER)) {
272 pr_err("DCSS %s and DCSS %s have "
273 "incompatible types\n",
274 sort_list[i].segment_name,
275 sort_list[i+1].segment_name);
276 rc = -EINVAL;
277 goto out;
278 }
279 }
280 }
281 rc = 0;
282 out:
283 kfree(sort_list);
284 return rc;
285 }
286
287 /*
288 * Load a segment
289 */
290 static int
291 dcssblk_load_segment(char *name, struct segment_info **seg_info)
292 {
293 int rc;
294
295 /* already loaded? */
296 down_read(&dcssblk_devices_sem);
297 *seg_info = dcssblk_get_segment_by_name(name);
298 up_read(&dcssblk_devices_sem);
299 if (*seg_info != NULL)
300 return -EEXIST;
301
302 /* get a struct segment_info */
303 *seg_info = kzalloc(sizeof(struct segment_info), GFP_KERNEL);
304 if (*seg_info == NULL)
305 return -ENOMEM;
306
307 strcpy((*seg_info)->segment_name, name);
308
309 /* load the segment */
310 rc = segment_load(name, SEGMENT_SHARED,
311 &(*seg_info)->start, &(*seg_info)->end);
312 if (rc < 0) {
313 segment_warning(rc, (*seg_info)->segment_name);
314 kfree(*seg_info);
315 } else {
316 INIT_LIST_HEAD(&(*seg_info)->lh);
317 (*seg_info)->segment_type = rc;
318 }
319 return rc;
320 }
321
322 static void dcssblk_unregister_callback(struct device *dev)
323 {
324 device_unregister(dev);
325 put_device(dev);
326 }
327
328 /*
329 * device attribute for switching shared/nonshared (exclusive)
330 * operation (show + store)
331 */
332 static ssize_t
333 dcssblk_shared_show(struct device *dev, struct device_attribute *attr, char *buf)
334 {
335 struct dcssblk_dev_info *dev_info;
336
337 dev_info = container_of(dev, struct dcssblk_dev_info, dev);
338 return sprintf(buf, dev_info->is_shared ? "1\n" : "0\n");
339 }
340
341 static ssize_t
342 dcssblk_shared_store(struct device *dev, struct device_attribute *attr, const char *inbuf, size_t count)
343 {
344 struct dcssblk_dev_info *dev_info;
345 struct segment_info *entry, *temp;
346 int rc;
347
348 if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0'))
349 return -EINVAL;
350 down_write(&dcssblk_devices_sem);
351 dev_info = container_of(dev, struct dcssblk_dev_info, dev);
352 if (atomic_read(&dev_info->use_count)) {
353 rc = -EBUSY;
354 goto out;
355 }
356 if (inbuf[0] == '1') {
357 /* reload segments in shared mode */
358 list_for_each_entry(entry, &dev_info->seg_list, lh) {
359 rc = segment_modify_shared(entry->segment_name,
360 SEGMENT_SHARED);
361 if (rc < 0) {
362 BUG_ON(rc == -EINVAL);
363 if (rc != -EAGAIN)
364 goto removeseg;
365 }
366 }
367 dev_info->is_shared = 1;
368 switch (dev_info->segment_type) {
369 case SEG_TYPE_SR:
370 case SEG_TYPE_ER:
371 case SEG_TYPE_SC:
372 set_disk_ro(dev_info->gd, 1);
373 }
374 } else if (inbuf[0] == '0') {
375 /* reload segments in exclusive mode */
376 if (dev_info->segment_type == SEG_TYPE_SC) {
377 pr_err("DCSS %s is of type SC and cannot be "
378 "loaded as exclusive-writable\n",
379 dev_info->segment_name);
380 rc = -EINVAL;
381 goto out;
382 }
383 list_for_each_entry(entry, &dev_info->seg_list, lh) {
384 rc = segment_modify_shared(entry->segment_name,
385 SEGMENT_EXCLUSIVE);
386 if (rc < 0) {
387 BUG_ON(rc == -EINVAL);
388 if (rc != -EAGAIN)
389 goto removeseg;
390 }
391 }
392 dev_info->is_shared = 0;
393 set_disk_ro(dev_info->gd, 0);
394 } else {
395 rc = -EINVAL;
396 goto out;
397 }
398 rc = count;
399 goto out;
400
401 removeseg:
402 pr_err("DCSS device %s is removed after a failed access mode "
403 "change\n", dev_info->segment_name);
404 temp = entry;
405 list_for_each_entry(entry, &dev_info->seg_list, lh) {
406 if (entry != temp)
407 segment_unload(entry->segment_name);
408 }
409 list_del(&dev_info->lh);
410
411 del_gendisk(dev_info->gd);
412 blk_cleanup_queue(dev_info->dcssblk_queue);
413 dev_info->gd->queue = NULL;
414 put_disk(dev_info->gd);
415 rc = device_schedule_callback(dev, dcssblk_unregister_callback);
416 out:
417 up_write(&dcssblk_devices_sem);
418 return rc;
419 }
420
421 /*
422 * device attribute for save operation on current copy
423 * of the segment. If the segment is busy, saving will
424 * become pending until it gets released, which can be
425 * undone by storing a non-true value to this entry.
426 * (show + store)
427 */
428 static ssize_t
429 dcssblk_save_show(struct device *dev, struct device_attribute *attr, char *buf)
430 {
431 struct dcssblk_dev_info *dev_info;
432
433 dev_info = container_of(dev, struct dcssblk_dev_info, dev);
434 return sprintf(buf, dev_info->save_pending ? "1\n" : "0\n");
435 }
436
437 static ssize_t
438 dcssblk_save_store(struct device *dev, struct device_attribute *attr, const char *inbuf, size_t count)
439 {
440 struct dcssblk_dev_info *dev_info;
441 struct segment_info *entry;
442
443 if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0'))
444 return -EINVAL;
445 dev_info = container_of(dev, struct dcssblk_dev_info, dev);
446
447 down_write(&dcssblk_devices_sem);
448 if (inbuf[0] == '1') {
449 if (atomic_read(&dev_info->use_count) == 0) {
450 // device is idle => we save immediately
451 pr_info("All DCSSs that map to device %s are "
452 "saved\n", dev_info->segment_name);
453 list_for_each_entry(entry, &dev_info->seg_list, lh) {
454 segment_save(entry->segment_name);
455 }
456 } else {
457 // device is busy => we save it when it becomes
458 // idle in dcssblk_release
459 pr_info("Device %s is in use, its DCSSs will be "
460 "saved when it becomes idle\n",
461 dev_info->segment_name);
462 dev_info->save_pending = 1;
463 }
464 } else if (inbuf[0] == '0') {
465 if (dev_info->save_pending) {
466 // device is busy & the user wants to undo his save
467 // request
468 dev_info->save_pending = 0;
469 pr_info("A pending save request for device %s "
470 "has been canceled\n",
471 dev_info->segment_name);
472 }
473 } else {
474 up_write(&dcssblk_devices_sem);
475 return -EINVAL;
476 }
477 up_write(&dcssblk_devices_sem);
478 return count;
479 }
480
481 /*
482 * device attribute for showing all segments in a device
483 */
484 static ssize_t
485 dcssblk_seglist_show(struct device *dev, struct device_attribute *attr,
486 char *buf)
487 {
488 int i;
489
490 struct dcssblk_dev_info *dev_info;
491 struct segment_info *entry;
492
493 down_read(&dcssblk_devices_sem);
494 dev_info = container_of(dev, struct dcssblk_dev_info, dev);
495 i = 0;
496 buf[0] = '\0';
497 list_for_each_entry(entry, &dev_info->seg_list, lh) {
498 strcpy(&buf[i], entry->segment_name);
499 i += strlen(entry->segment_name);
500 buf[i] = '\n';
501 i++;
502 }
503 up_read(&dcssblk_devices_sem);
504 return i;
505 }
506
507 /*
508 * device attribute for adding devices
509 */
510 static ssize_t
511 dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
512 {
513 int rc, i, j, num_of_segments;
514 struct dcssblk_dev_info *dev_info;
515 struct segment_info *seg_info, *temp;
516 char *local_buf;
517 unsigned long seg_byte_size;
518
519 dev_info = NULL;
520 seg_info = NULL;
521 if (dev != dcssblk_root_dev) {
522 rc = -EINVAL;
523 goto out_nobuf;
524 }
525 if ((count < 1) || (buf[0] == '\0') || (buf[0] == '\n')) {
526 rc = -ENAMETOOLONG;
527 goto out_nobuf;
528 }
529
530 local_buf = kmalloc(count + 1, GFP_KERNEL);
531 if (local_buf == NULL) {
532 rc = -ENOMEM;
533 goto out_nobuf;
534 }
535
536 /*
537 * parse input
538 */
539 num_of_segments = 0;
540 for (i = 0; ((buf[i] != '\0') && (buf[i] != '\n') && i < count); i++) {
541 for (j = i; (buf[j] != ':') &&
542 (buf[j] != '\0') &&
543 (buf[j] != '\n') &&
544 j < count; j++) {
545 local_buf[j-i] = toupper(buf[j]);
546 }
547 local_buf[j-i] = '\0';
548 if (((j - i) == 0) || ((j - i) > 8)) {
549 rc = -ENAMETOOLONG;
550 goto seg_list_del;
551 }
552
553 rc = dcssblk_load_segment(local_buf, &seg_info);
554 if (rc < 0)
555 goto seg_list_del;
556 /*
557 * get a struct dcssblk_dev_info
558 */
559 if (num_of_segments == 0) {
560 dev_info = kzalloc(sizeof(struct dcssblk_dev_info),
561 GFP_KERNEL);
562 if (dev_info == NULL) {
563 rc = -ENOMEM;
564 goto out;
565 }
566 strcpy(dev_info->segment_name, local_buf);
567 dev_info->segment_type = seg_info->segment_type;
568 INIT_LIST_HEAD(&dev_info->seg_list);
569 }
570 list_add_tail(&seg_info->lh, &dev_info->seg_list);
571 num_of_segments++;
572 i = j;
573
574 if ((buf[j] == '\0') || (buf[j] == '\n'))
575 break;
576 }
577
578 /* no trailing colon at the end of the input */
579 if ((i > 0) && (buf[i-1] == ':')) {
580 rc = -ENAMETOOLONG;
581 goto seg_list_del;
582 }
583 strlcpy(local_buf, buf, i + 1);
584 dev_info->num_of_segments = num_of_segments;
585 rc = dcssblk_is_continuous(dev_info);
586 if (rc < 0)
587 goto seg_list_del;
588
589 dev_info->start = dcssblk_find_lowest_addr(dev_info);
590 dev_info->end = dcssblk_find_highest_addr(dev_info);
591
592 dev_set_name(&dev_info->dev, dev_info->segment_name);
593 dev_info->dev.release = dcssblk_release_segment;
594 INIT_LIST_HEAD(&dev_info->lh);
595 dev_info->gd = alloc_disk(DCSSBLK_MINORS_PER_DISK);
596 if (dev_info->gd == NULL) {
597 rc = -ENOMEM;
598 goto seg_list_del;
599 }
600 dev_info->gd->major = dcssblk_major;
601 dev_info->gd->fops = &dcssblk_devops;
602 dev_info->dcssblk_queue = blk_alloc_queue(GFP_KERNEL);
603 dev_info->gd->queue = dev_info->dcssblk_queue;
604 dev_info->gd->private_data = dev_info;
605 dev_info->gd->driverfs_dev = &dev_info->dev;
606 blk_queue_make_request(dev_info->dcssblk_queue, dcssblk_make_request);
607 blk_queue_logical_block_size(dev_info->dcssblk_queue, 4096);
608
609 seg_byte_size = (dev_info->end - dev_info->start + 1);
610 set_capacity(dev_info->gd, seg_byte_size >> 9); // size in sectors
611 pr_info("Loaded %s with total size %lu bytes and capacity %lu "
612 "sectors\n", local_buf, seg_byte_size, seg_byte_size >> 9);
613
614 dev_info->save_pending = 0;
615 dev_info->is_shared = 1;
616 dev_info->dev.parent = dcssblk_root_dev;
617
618 /*
619 *get minor, add to list
620 */
621 down_write(&dcssblk_devices_sem);
622 if (dcssblk_get_segment_by_name(local_buf)) {
623 rc = -EEXIST;
624 goto release_gd;
625 }
626 rc = dcssblk_assign_free_minor(dev_info);
627 if (rc)
628 goto release_gd;
629 sprintf(dev_info->gd->disk_name, "dcssblk%d",
630 dev_info->gd->first_minor);
631 list_add_tail(&dev_info->lh, &dcssblk_devices);
632
633 if (!try_module_get(THIS_MODULE)) {
634 rc = -ENODEV;
635 goto dev_list_del;
636 }
637 /*
638 * register the device
639 */
640 rc = device_register(&dev_info->dev);
641 if (rc) {
642 module_put(THIS_MODULE);
643 goto dev_list_del;
644 }
645 get_device(&dev_info->dev);
646 rc = device_create_file(&dev_info->dev, &dev_attr_shared);
647 if (rc)
648 goto unregister_dev;
649 rc = device_create_file(&dev_info->dev, &dev_attr_save);
650 if (rc)
651 goto unregister_dev;
652 rc = device_create_file(&dev_info->dev, &dev_attr_seglist);
653 if (rc)
654 goto unregister_dev;
655
656 add_disk(dev_info->gd);
657
658 switch (dev_info->segment_type) {
659 case SEG_TYPE_SR:
660 case SEG_TYPE_ER:
661 case SEG_TYPE_SC:
662 set_disk_ro(dev_info->gd,1);
663 break;
664 default:
665 set_disk_ro(dev_info->gd,0);
666 break;
667 }
668 up_write(&dcssblk_devices_sem);
669 rc = count;
670 goto out;
671
672 unregister_dev:
673 list_del(&dev_info->lh);
674 blk_cleanup_queue(dev_info->dcssblk_queue);
675 dev_info->gd->queue = NULL;
676 put_disk(dev_info->gd);
677 device_unregister(&dev_info->dev);
678 list_for_each_entry(seg_info, &dev_info->seg_list, lh) {
679 segment_unload(seg_info->segment_name);
680 }
681 put_device(&dev_info->dev);
682 up_write(&dcssblk_devices_sem);
683 goto out;
684 dev_list_del:
685 list_del(&dev_info->lh);
686 release_gd:
687 blk_cleanup_queue(dev_info->dcssblk_queue);
688 dev_info->gd->queue = NULL;
689 put_disk(dev_info->gd);
690 up_write(&dcssblk_devices_sem);
691 seg_list_del:
692 if (dev_info == NULL)
693 goto out;
694 list_for_each_entry_safe(seg_info, temp, &dev_info->seg_list, lh) {
695 list_del(&seg_info->lh);
696 segment_unload(seg_info->segment_name);
697 kfree(seg_info);
698 }
699 kfree(dev_info);
700 out:
701 kfree(local_buf);
702 out_nobuf:
703 return rc;
704 }
705
706 /*
707 * device attribute for removing devices
708 */
709 static ssize_t
710 dcssblk_remove_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
711 {
712 struct dcssblk_dev_info *dev_info;
713 struct segment_info *entry;
714 int rc, i;
715 char *local_buf;
716
717 if (dev != dcssblk_root_dev) {
718 return -EINVAL;
719 }
720 local_buf = kmalloc(count + 1, GFP_KERNEL);
721 if (local_buf == NULL) {
722 return -ENOMEM;
723 }
724 /*
725 * parse input
726 */
727 for (i = 0; ((*(buf+i)!='\0') && (*(buf+i)!='\n') && i < count); i++) {
728 local_buf[i] = toupper(buf[i]);
729 }
730 local_buf[i] = '\0';
731 if ((i == 0) || (i > 8)) {
732 rc = -ENAMETOOLONG;
733 goto out_buf;
734 }
735
736 down_write(&dcssblk_devices_sem);
737 dev_info = dcssblk_get_device_by_name(local_buf);
738 if (dev_info == NULL) {
739 up_write(&dcssblk_devices_sem);
740 pr_warning("Device %s cannot be removed because it is not a "
741 "known device\n", local_buf);
742 rc = -ENODEV;
743 goto out_buf;
744 }
745 if (atomic_read(&dev_info->use_count) != 0) {
746 up_write(&dcssblk_devices_sem);
747 pr_warning("Device %s cannot be removed while it is in "
748 "use\n", local_buf);
749 rc = -EBUSY;
750 goto out_buf;
751 }
752
753 list_del(&dev_info->lh);
754 del_gendisk(dev_info->gd);
755 blk_cleanup_queue(dev_info->dcssblk_queue);
756 dev_info->gd->queue = NULL;
757 put_disk(dev_info->gd);
758 device_unregister(&dev_info->dev);
759
760 /* unload all related segments */
761 list_for_each_entry(entry, &dev_info->seg_list, lh)
762 segment_unload(entry->segment_name);
763
764 put_device(&dev_info->dev);
765 up_write(&dcssblk_devices_sem);
766
767 rc = count;
768 out_buf:
769 kfree(local_buf);
770 return rc;
771 }
772
773 static int
774 dcssblk_open(struct block_device *bdev, fmode_t mode)
775 {
776 struct dcssblk_dev_info *dev_info;
777 int rc;
778
779 lock_kernel();
780 dev_info = bdev->bd_disk->private_data;
781 if (NULL == dev_info) {
782 rc = -ENODEV;
783 goto out;
784 }
785 atomic_inc(&dev_info->use_count);
786 bdev->bd_block_size = 4096;
787 rc = 0;
788 out:
789 unlock_kernel();
790 return rc;
791 }
792
793 static int
794 dcssblk_release(struct gendisk *disk, fmode_t mode)
795 {
796 struct dcssblk_dev_info *dev_info = disk->private_data;
797 struct segment_info *entry;
798 int rc;
799
800 lock_kernel();
801 if (!dev_info) {
802 rc = -ENODEV;
803 goto out;
804 }
805 down_write(&dcssblk_devices_sem);
806 if (atomic_dec_and_test(&dev_info->use_count)
807 && (dev_info->save_pending)) {
808 pr_info("Device %s has become idle and is being saved "
809 "now\n", dev_info->segment_name);
810 list_for_each_entry(entry, &dev_info->seg_list, lh) {
811 segment_save(entry->segment_name);
812 }
813 dev_info->save_pending = 0;
814 }
815 up_write(&dcssblk_devices_sem);
816 rc = 0;
817 out:
818 unlock_kernel();
819 return rc;
820 }
821
822 static int
823 dcssblk_make_request(struct request_queue *q, struct bio *bio)
824 {
825 struct dcssblk_dev_info *dev_info;
826 struct bio_vec *bvec;
827 unsigned long index;
828 unsigned long page_addr;
829 unsigned long source_addr;
830 unsigned long bytes_done;
831 int i;
832
833 bytes_done = 0;
834 dev_info = bio->bi_bdev->bd_disk->private_data;
835 if (dev_info == NULL)
836 goto fail;
837 if ((bio->bi_sector & 7) != 0 || (bio->bi_size & 4095) != 0)
838 /* Request is not page-aligned. */
839 goto fail;
840 if (((bio->bi_size >> 9) + bio->bi_sector)
841 > get_capacity(bio->bi_bdev->bd_disk)) {
842 /* Request beyond end of DCSS segment. */
843 goto fail;
844 }
845 /* verify data transfer direction */
846 if (dev_info->is_shared) {
847 switch (dev_info->segment_type) {
848 case SEG_TYPE_SR:
849 case SEG_TYPE_ER:
850 case SEG_TYPE_SC:
851 /* cannot write to these segments */
852 if (bio_data_dir(bio) == WRITE) {
853 pr_warning("Writing to %s failed because it "
854 "is a read-only device\n",
855 dev_name(&dev_info->dev));
856 goto fail;
857 }
858 }
859 }
860
861 index = (bio->bi_sector >> 3);
862 bio_for_each_segment(bvec, bio, i) {
863 page_addr = (unsigned long)
864 page_address(bvec->bv_page) + bvec->bv_offset;
865 source_addr = dev_info->start + (index<<12) + bytes_done;
866 if (unlikely((page_addr & 4095) != 0) || (bvec->bv_len & 4095) != 0)
867 // More paranoia.
868 goto fail;
869 if (bio_data_dir(bio) == READ) {
870 memcpy((void*)page_addr, (void*)source_addr,
871 bvec->bv_len);
872 } else {
873 memcpy((void*)source_addr, (void*)page_addr,
874 bvec->bv_len);
875 }
876 bytes_done += bvec->bv_len;
877 }
878 bio_endio(bio, 0);
879 return 0;
880 fail:
881 bio_io_error(bio);
882 return 0;
883 }
884
885 static int
886 dcssblk_direct_access (struct block_device *bdev, sector_t secnum,
887 void **kaddr, unsigned long *pfn)
888 {
889 struct dcssblk_dev_info *dev_info;
890 unsigned long pgoff;
891
892 dev_info = bdev->bd_disk->private_data;
893 if (!dev_info)
894 return -ENODEV;
895 if (secnum % (PAGE_SIZE/512))
896 return -EINVAL;
897 pgoff = secnum / (PAGE_SIZE / 512);
898 if ((pgoff+1)*PAGE_SIZE-1 > dev_info->end - dev_info->start)
899 return -ERANGE;
900 *kaddr = (void *) (dev_info->start+pgoff*PAGE_SIZE);
901 *pfn = virt_to_phys(*kaddr) >> PAGE_SHIFT;
902
903 return 0;
904 }
905
906 static void
907 dcssblk_check_params(void)
908 {
909 int rc, i, j, k;
910 char buf[DCSSBLK_PARM_LEN + 1];
911 struct dcssblk_dev_info *dev_info;
912
913 for (i = 0; (i < DCSSBLK_PARM_LEN) && (dcssblk_segments[i] != '\0');
914 i++) {
915 for (j = i; (dcssblk_segments[j] != ',') &&
916 (dcssblk_segments[j] != '\0') &&
917 (dcssblk_segments[j] != '(') &&
918 (j < DCSSBLK_PARM_LEN); j++)
919 {
920 buf[j-i] = dcssblk_segments[j];
921 }
922 buf[j-i] = '\0';
923 rc = dcssblk_add_store(dcssblk_root_dev, NULL, buf, j-i);
924 if ((rc >= 0) && (dcssblk_segments[j] == '(')) {
925 for (k = 0; (buf[k] != ':') && (buf[k] != '\0'); k++)
926 buf[k] = toupper(buf[k]);
927 buf[k] = '\0';
928 if (!strncmp(&dcssblk_segments[j], "(local)", 7)) {
929 down_read(&dcssblk_devices_sem);
930 dev_info = dcssblk_get_device_by_name(buf);
931 up_read(&dcssblk_devices_sem);
932 if (dev_info)
933 dcssblk_shared_store(&dev_info->dev,
934 NULL, "0\n", 2);
935 }
936 }
937 while ((dcssblk_segments[j] != ',') &&
938 (dcssblk_segments[j] != '\0'))
939 {
940 j++;
941 }
942 if (dcssblk_segments[j] == '\0')
943 break;
944 i = j;
945 }
946 }
947
948 /*
949 * Suspend / Resume
950 */
951 static int dcssblk_freeze(struct device *dev)
952 {
953 struct dcssblk_dev_info *dev_info;
954 int rc = 0;
955
956 list_for_each_entry(dev_info, &dcssblk_devices, lh) {
957 switch (dev_info->segment_type) {
958 case SEG_TYPE_SR:
959 case SEG_TYPE_ER:
960 case SEG_TYPE_SC:
961 if (!dev_info->is_shared)
962 rc = -EINVAL;
963 break;
964 default:
965 rc = -EINVAL;
966 break;
967 }
968 if (rc)
969 break;
970 }
971 if (rc)
972 pr_err("Suspending the system failed because DCSS device %s "
973 "is writable\n",
974 dev_info->segment_name);
975 return rc;
976 }
977
978 static int dcssblk_restore(struct device *dev)
979 {
980 struct dcssblk_dev_info *dev_info;
981 struct segment_info *entry;
982 unsigned long start, end;
983 int rc = 0;
984
985 list_for_each_entry(dev_info, &dcssblk_devices, lh) {
986 list_for_each_entry(entry, &dev_info->seg_list, lh) {
987 segment_unload(entry->segment_name);
988 rc = segment_load(entry->segment_name, SEGMENT_SHARED,
989 &start, &end);
990 if (rc < 0) {
991 // TODO in_use check ?
992 segment_warning(rc, entry->segment_name);
993 goto out_panic;
994 }
995 if (start != entry->start || end != entry->end) {
996 pr_err("The address range of DCSS %s changed "
997 "while the system was suspended\n",
998 entry->segment_name);
999 goto out_panic;
1000 }
1001 }
1002 }
1003 return 0;
1004 out_panic:
1005 panic("fatal dcssblk resume error\n");
1006 }
1007
1008 static int dcssblk_thaw(struct device *dev)
1009 {
1010 return 0;
1011 }
1012
1013 static const struct dev_pm_ops dcssblk_pm_ops = {
1014 .freeze = dcssblk_freeze,
1015 .thaw = dcssblk_thaw,
1016 .restore = dcssblk_restore,
1017 };
1018
1019 static struct platform_driver dcssblk_pdrv = {
1020 .driver = {
1021 .name = "dcssblk",
1022 .owner = THIS_MODULE,
1023 .pm = &dcssblk_pm_ops,
1024 },
1025 };
1026
1027 static struct platform_device *dcssblk_pdev;
1028
1029
1030 /*
1031 * The init/exit functions.
1032 */
1033 static void __exit
1034 dcssblk_exit(void)
1035 {
1036 platform_device_unregister(dcssblk_pdev);
1037 platform_driver_unregister(&dcssblk_pdrv);
1038 root_device_unregister(dcssblk_root_dev);
1039 unregister_blkdev(dcssblk_major, DCSSBLK_NAME);
1040 }
1041
1042 static int __init
1043 dcssblk_init(void)
1044 {
1045 int rc;
1046
1047 rc = platform_driver_register(&dcssblk_pdrv);
1048 if (rc)
1049 return rc;
1050
1051 dcssblk_pdev = platform_device_register_simple("dcssblk", -1, NULL,
1052 0);
1053 if (IS_ERR(dcssblk_pdev)) {
1054 rc = PTR_ERR(dcssblk_pdev);
1055 goto out_pdrv;
1056 }
1057
1058 dcssblk_root_dev = root_device_register("dcssblk");
1059 if (IS_ERR(dcssblk_root_dev)) {
1060 rc = PTR_ERR(dcssblk_root_dev);
1061 goto out_pdev;
1062 }
1063 rc = device_create_file(dcssblk_root_dev, &dev_attr_add);
1064 if (rc)
1065 goto out_root;
1066 rc = device_create_file(dcssblk_root_dev, &dev_attr_remove);
1067 if (rc)
1068 goto out_root;
1069 rc = register_blkdev(0, DCSSBLK_NAME);
1070 if (rc < 0)
1071 goto out_root;
1072 dcssblk_major = rc;
1073 init_rwsem(&dcssblk_devices_sem);
1074
1075 dcssblk_check_params();
1076 return 0;
1077
1078 out_root:
1079 root_device_unregister(dcssblk_root_dev);
1080 out_pdev:
1081 platform_device_unregister(dcssblk_pdev);
1082 out_pdrv:
1083 platform_driver_unregister(&dcssblk_pdrv);
1084 return rc;
1085 }
1086
1087 module_init(dcssblk_init);
1088 module_exit(dcssblk_exit);
1089
1090 module_param_string(segments, dcssblk_segments, DCSSBLK_PARM_LEN, 0444);
1091 MODULE_PARM_DESC(segments, "Name of DCSS segment(s) to be loaded, "
1092 "comma-separated list, names in each set separated "
1093 "by commas are separated by colons, each set contains "
1094 "names of contiguous segments and each name max. 8 chars.\n"
1095 "Adding \"(local)\" to the end of each set equals echoing 0 "
1096 "to /sys/devices/dcssblk/<device name>/shared after loading "
1097 "the contiguous segments - \n"
1098 "e.g. segments=\"mydcss1,mydcss2:mydcss3,mydcss4(local)\"");
1099
1100 MODULE_LICENSE("GPL");
Tomato firmware and modifications.