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block: make variable and argument names more consistent
[net-next-2.6.git] / drivers / s390 / block / dcssblk.c
CommitLineData
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
7#include <linux/module.h>
8#include <linux/moduleparam.h>
9#include <linux/ctype.h>
10#include <linux/errno.h>
11#include <linux/init.h>
12#include <linux/slab.h>
13#include <linux/blkdev.h>
14#include <asm/extmem.h>
15#include <asm/io.h>
16#include <linux/completion.h>
17#include <linux/interrupt.h>
cfb1b555 18#include <asm/s390_rdev.h>
1da177e4
LT
19
20//#define DCSSBLK_DEBUG /* Debug messages on/off */
21#define DCSSBLK_NAME "dcssblk"
22#define DCSSBLK_MINORS_PER_DISK 1
23#define DCSSBLK_PARM_LEN 400
24
25#ifdef DCSSBLK_DEBUG
26#define PRINT_DEBUG(x...) printk(KERN_DEBUG DCSSBLK_NAME " debug: " x)
27#else
28#define PRINT_DEBUG(x...) do {} while (0)
29#endif
30#define PRINT_INFO(x...) printk(KERN_INFO DCSSBLK_NAME " info: " x)
31#define PRINT_WARN(x...) printk(KERN_WARNING DCSSBLK_NAME " warning: " x)
32#define PRINT_ERR(x...) printk(KERN_ERR DCSSBLK_NAME " error: " x)
33
34
35static int dcssblk_open(struct inode *inode, struct file *filp);
36static int dcssblk_release(struct inode *inode, struct file *filp);
37static int dcssblk_make_request(struct request_queue *q, struct bio *bio);
420edbcc 38static int dcssblk_direct_access(struct block_device *bdev, sector_t secnum,
30afcb4b 39 void **kaddr, unsigned long *pfn);
1da177e4
LT
40
41static char dcssblk_segments[DCSSBLK_PARM_LEN] = "\0";
42
43static int dcssblk_major;
44static struct block_device_operations dcssblk_devops = {
420edbcc
CO
45 .owner = THIS_MODULE,
46 .open = dcssblk_open,
47 .release = dcssblk_release,
48 .direct_access = dcssblk_direct_access,
1da177e4
LT
49};
50
e404e274 51static ssize_t dcssblk_add_store(struct device * dev, struct device_attribute *attr, const char * buf,
1da177e4 52 size_t count);
e404e274 53static ssize_t dcssblk_remove_store(struct device * dev, struct device_attribute *attr, const char * buf,
1da177e4 54 size_t count);
e404e274 55static ssize_t dcssblk_save_store(struct device * dev, struct device_attribute *attr, const char * buf,
1da177e4 56 size_t count);
e404e274
YI
57static ssize_t dcssblk_save_show(struct device *dev, struct device_attribute *attr, char *buf);
58static ssize_t dcssblk_shared_store(struct device * dev, struct device_attribute *attr, const char * buf,
1da177e4 59 size_t count);
e404e274 60static ssize_t dcssblk_shared_show(struct device *dev, struct device_attribute *attr, char *buf);
1da177e4
LT
61
62static DEVICE_ATTR(add, S_IWUSR, NULL, dcssblk_add_store);
63static DEVICE_ATTR(remove, S_IWUSR, NULL, dcssblk_remove_store);
64static DEVICE_ATTR(save, S_IWUSR | S_IRUGO, dcssblk_save_show,
65 dcssblk_save_store);
66static DEVICE_ATTR(shared, S_IWUSR | S_IRUGO, dcssblk_shared_show,
67 dcssblk_shared_store);
68
69static struct device *dcssblk_root_dev;
70
71struct dcssblk_dev_info {
72 struct list_head lh;
73 struct device dev;
74 char segment_name[BUS_ID_SIZE];
75 atomic_t use_count;
76 struct gendisk *gd;
77 unsigned long start;
78 unsigned long end;
79 int segment_type;
80 unsigned char save_pending;
81 unsigned char is_shared;
82 struct request_queue *dcssblk_queue;
83};
84
c11ca97e 85static LIST_HEAD(dcssblk_devices);
1da177e4
LT
86static struct rw_semaphore dcssblk_devices_sem;
87
88/*
89 * release function for segment device.
90 */
91static void
92dcssblk_release_segment(struct device *dev)
93{
94 PRINT_DEBUG("segment release fn called for %s\n", dev->bus_id);
95 kfree(container_of(dev, struct dcssblk_dev_info, dev));
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 105static int
1da177e4
LT
106dcssblk_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)
117 if (minor == entry->gd->first_minor)
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 */
132static struct dcssblk_dev_info *
133dcssblk_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
931bb68b
GS
145static void dcssblk_unregister_callback(struct device *dev)
146{
147 device_unregister(dev);
148 put_device(dev);
149}
150
1da177e4
LT
151/*
152 * device attribute for switching shared/nonshared (exclusive)
153 * operation (show + store)
154 */
155static ssize_t
e404e274 156dcssblk_shared_show(struct device *dev, struct device_attribute *attr, char *buf)
1da177e4
LT
157{
158 struct dcssblk_dev_info *dev_info;
159
160 dev_info = container_of(dev, struct dcssblk_dev_info, dev);
161 return sprintf(buf, dev_info->is_shared ? "1\n" : "0\n");
162}
163
164static ssize_t
e404e274 165dcssblk_shared_store(struct device *dev, struct device_attribute *attr, const char *inbuf, size_t count)
1da177e4
LT
166{
167 struct dcssblk_dev_info *dev_info;
168 int rc;
169
ded77fb4 170 if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0'))
1da177e4 171 return -EINVAL;
1da177e4
LT
172 down_write(&dcssblk_devices_sem);
173 dev_info = container_of(dev, struct dcssblk_dev_info, dev);
174 if (atomic_read(&dev_info->use_count)) {
175 PRINT_ERR("share: segment %s is busy!\n",
176 dev_info->segment_name);
177 rc = -EBUSY;
178 goto out;
179 }
180 if (inbuf[0] == '1') {
181 // reload segment in shared mode
182 rc = segment_modify_shared(dev_info->segment_name,
183 SEGMENT_SHARED);
184 if (rc < 0) {
185 BUG_ON(rc == -EINVAL);
444f0e54 186 if (rc != -EAGAIN)
1da177e4
LT
187 goto removeseg;
188 } else {
189 dev_info->is_shared = 1;
190 switch (dev_info->segment_type) {
191 case SEG_TYPE_SR:
192 case SEG_TYPE_ER:
193 case SEG_TYPE_SC:
194 set_disk_ro(dev_info->gd,1);
195 }
196 }
197 } else if (inbuf[0] == '0') {
198 // reload segment in exclusive mode
199 if (dev_info->segment_type == SEG_TYPE_SC) {
200 PRINT_ERR("Segment type SC (%s) cannot be loaded in "
201 "non-shared mode\n", dev_info->segment_name);
202 rc = -EINVAL;
203 goto out;
204 }
205 rc = segment_modify_shared(dev_info->segment_name,
206 SEGMENT_EXCLUSIVE);
207 if (rc < 0) {
208 BUG_ON(rc == -EINVAL);
444f0e54 209 if (rc != -EAGAIN)
1da177e4
LT
210 goto removeseg;
211 } else {
212 dev_info->is_shared = 0;
213 set_disk_ro(dev_info->gd, 0);
214 }
215 } else {
1da177e4
LT
216 rc = -EINVAL;
217 goto out;
218 }
219 rc = count;
220 goto out;
221
222removeseg:
223 PRINT_ERR("Could not reload segment %s, removing it now!\n",
224 dev_info->segment_name);
225 list_del(&dev_info->lh);
226
227 del_gendisk(dev_info->gd);
1312f40e 228 blk_cleanup_queue(dev_info->dcssblk_queue);
1da177e4
LT
229 dev_info->gd->queue = NULL;
230 put_disk(dev_info->gd);
931bb68b 231 rc = device_schedule_callback(dev, dcssblk_unregister_callback);
1da177e4
LT
232out:
233 up_write(&dcssblk_devices_sem);
234 return rc;
235}
236
237/*
238 * device attribute for save operation on current copy
239 * of the segment. If the segment is busy, saving will
240 * become pending until it gets released, which can be
241 * undone by storing a non-true value to this entry.
242 * (show + store)
243 */
244static ssize_t
e404e274 245dcssblk_save_show(struct device *dev, struct device_attribute *attr, char *buf)
1da177e4
LT
246{
247 struct dcssblk_dev_info *dev_info;
248
249 dev_info = container_of(dev, struct dcssblk_dev_info, dev);
250 return sprintf(buf, dev_info->save_pending ? "1\n" : "0\n");
251}
252
253static ssize_t
e404e274 254dcssblk_save_store(struct device *dev, struct device_attribute *attr, const char *inbuf, size_t count)
1da177e4
LT
255{
256 struct dcssblk_dev_info *dev_info;
257
ded77fb4 258 if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0'))
1da177e4 259 return -EINVAL;
1da177e4
LT
260 dev_info = container_of(dev, struct dcssblk_dev_info, dev);
261
262 down_write(&dcssblk_devices_sem);
263 if (inbuf[0] == '1') {
264 if (atomic_read(&dev_info->use_count) == 0) {
265 // device is idle => we save immediately
266 PRINT_INFO("Saving segment %s\n",
267 dev_info->segment_name);
268 segment_save(dev_info->segment_name);
269 } else {
270 // device is busy => we save it when it becomes
271 // idle in dcssblk_release
272 PRINT_INFO("Segment %s is currently busy, it will "
273 "be saved when it becomes idle...\n",
274 dev_info->segment_name);
275 dev_info->save_pending = 1;
276 }
277 } else if (inbuf[0] == '0') {
278 if (dev_info->save_pending) {
279 // device is busy & the user wants to undo his save
280 // request
281 dev_info->save_pending = 0;
282 PRINT_INFO("Pending save for segment %s deactivated\n",
283 dev_info->segment_name);
284 }
285 } else {
286 up_write(&dcssblk_devices_sem);
1da177e4
LT
287 return -EINVAL;
288 }
289 up_write(&dcssblk_devices_sem);
290 return count;
291}
292
293/*
294 * device attribute for adding devices
295 */
296static ssize_t
e404e274 297dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
1da177e4
LT
298{
299 int rc, i;
300 struct dcssblk_dev_info *dev_info;
301 char *local_buf;
302 unsigned long seg_byte_size;
303
304 dev_info = NULL;
305 if (dev != dcssblk_root_dev) {
306 rc = -EINVAL;
307 goto out_nobuf;
308 }
309 local_buf = kmalloc(count + 1, GFP_KERNEL);
310 if (local_buf == NULL) {
311 rc = -ENOMEM;
312 goto out_nobuf;
313 }
314 /*
315 * parse input
316 */
317 for (i = 0; ((buf[i] != '\0') && (buf[i] != '\n') && i < count); i++) {
318 local_buf[i] = toupper(buf[i]);
319 }
320 local_buf[i] = '\0';
321 if ((i == 0) || (i > 8)) {
322 rc = -ENAMETOOLONG;
323 goto out;
324 }
325 /*
326 * already loaded?
327 */
328 down_read(&dcssblk_devices_sem);
329 dev_info = dcssblk_get_device_by_name(local_buf);
330 up_read(&dcssblk_devices_sem);
331 if (dev_info != NULL) {
332 PRINT_WARN("Segment %s already loaded!\n", local_buf);
333 rc = -EEXIST;
334 goto out;
335 }
336 /*
337 * get a struct dcssblk_dev_info
338 */
88abaab4 339 dev_info = kzalloc(sizeof(struct dcssblk_dev_info), GFP_KERNEL);
1da177e4
LT
340 if (dev_info == NULL) {
341 rc = -ENOMEM;
342 goto out;
343 }
1da177e4
LT
344
345 strcpy(dev_info->segment_name, local_buf);
346 strlcpy(dev_info->dev.bus_id, local_buf, BUS_ID_SIZE);
347 dev_info->dev.release = dcssblk_release_segment;
348 INIT_LIST_HEAD(&dev_info->lh);
349
350 dev_info->gd = alloc_disk(DCSSBLK_MINORS_PER_DISK);
351 if (dev_info->gd == NULL) {
352 rc = -ENOMEM;
353 goto free_dev_info;
354 }
355 dev_info->gd->major = dcssblk_major;
356 dev_info->gd->fops = &dcssblk_devops;
357 dev_info->dcssblk_queue = blk_alloc_queue(GFP_KERNEL);
358 dev_info->gd->queue = dev_info->dcssblk_queue;
359 dev_info->gd->private_data = dev_info;
360 dev_info->gd->driverfs_dev = &dev_info->dev;
c5411dba
HC
361 blk_queue_make_request(dev_info->dcssblk_queue, dcssblk_make_request);
362 blk_queue_hardsect_size(dev_info->dcssblk_queue, 4096);
1da177e4
LT
363 /*
364 * load the segment
365 */
366 rc = segment_load(local_buf, SEGMENT_SHARED,
367 &dev_info->start, &dev_info->end);
368 if (rc < 0) {
ca68305b 369 segment_warning(rc, dev_info->segment_name);
1da177e4
LT
370 goto dealloc_gendisk;
371 }
372 seg_byte_size = (dev_info->end - dev_info->start + 1);
373 set_capacity(dev_info->gd, seg_byte_size >> 9); // size in sectors
374 PRINT_INFO("Loaded segment %s, size = %lu Byte, "
375 "capacity = %lu (512 Byte) sectors\n", local_buf,
376 seg_byte_size, seg_byte_size >> 9);
377
378 dev_info->segment_type = rc;
379 dev_info->save_pending = 0;
380 dev_info->is_shared = 1;
381 dev_info->dev.parent = dcssblk_root_dev;
382
383 /*
384 * get minor, add to list
385 */
386 down_write(&dcssblk_devices_sem);
dbe13d99
HC
387 if (dcssblk_get_device_by_name(local_buf)) {
388 up_write(&dcssblk_devices_sem);
04f64b57 389 rc = -EEXIST;
dbe13d99 390 goto unload_seg;
04f64b57 391 }
1da177e4
LT
392 rc = dcssblk_assign_free_minor(dev_info);
393 if (rc) {
394 up_write(&dcssblk_devices_sem);
395 PRINT_ERR("No free minor number available! "
396 "Unloading segment...\n");
397 goto unload_seg;
398 }
399 sprintf(dev_info->gd->disk_name, "dcssblk%d",
400 dev_info->gd->first_minor);
401 list_add_tail(&dev_info->lh, &dcssblk_devices);
402
403 if (!try_module_get(THIS_MODULE)) {
404 rc = -ENODEV;
405 goto list_del;
406 }
407 /*
408 * register the device
409 */
410 rc = device_register(&dev_info->dev);
411 if (rc) {
412 PRINT_ERR("Segment %s could not be registered RC=%d\n",
413 local_buf, rc);
414 module_put(THIS_MODULE);
415 goto list_del;
416 }
417 get_device(&dev_info->dev);
418 rc = device_create_file(&dev_info->dev, &dev_attr_shared);
419 if (rc)
420 goto unregister_dev;
421 rc = device_create_file(&dev_info->dev, &dev_attr_save);
422 if (rc)
423 goto unregister_dev;
424
436d1bc7
CB
425 add_disk(dev_info->gd);
426
1da177e4
LT
427 switch (dev_info->segment_type) {
428 case SEG_TYPE_SR:
429 case SEG_TYPE_ER:
430 case SEG_TYPE_SC:
431 set_disk_ro(dev_info->gd,1);
432 break;
433 default:
434 set_disk_ro(dev_info->gd,0);
435 break;
436 }
437 PRINT_DEBUG("Segment %s loaded successfully\n", local_buf);
438 up_write(&dcssblk_devices_sem);
439 rc = count;
440 goto out;
441
442unregister_dev:
1da177e4 443 list_del(&dev_info->lh);
1312f40e 444 blk_cleanup_queue(dev_info->dcssblk_queue);
1da177e4
LT
445 dev_info->gd->queue = NULL;
446 put_disk(dev_info->gd);
447 device_unregister(&dev_info->dev);
448 segment_unload(dev_info->segment_name);
449 put_device(&dev_info->dev);
450 up_write(&dcssblk_devices_sem);
451 goto out;
452list_del:
453 list_del(&dev_info->lh);
454 up_write(&dcssblk_devices_sem);
455unload_seg:
456 segment_unload(local_buf);
457dealloc_gendisk:
1312f40e 458 blk_cleanup_queue(dev_info->dcssblk_queue);
1da177e4
LT
459 dev_info->gd->queue = NULL;
460 put_disk(dev_info->gd);
461free_dev_info:
462 kfree(dev_info);
463out:
464 kfree(local_buf);
465out_nobuf:
466 return rc;
467}
468
469/*
470 * device attribute for removing devices
471 */
472static ssize_t
e404e274 473dcssblk_remove_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
1da177e4
LT
474{
475 struct dcssblk_dev_info *dev_info;
476 int rc, i;
477 char *local_buf;
478
479 if (dev != dcssblk_root_dev) {
480 return -EINVAL;
481 }
482 local_buf = kmalloc(count + 1, GFP_KERNEL);
483 if (local_buf == NULL) {
484 return -ENOMEM;
485 }
486 /*
487 * parse input
488 */
489 for (i = 0; ((*(buf+i)!='\0') && (*(buf+i)!='\n') && i < count); i++) {
490 local_buf[i] = toupper(buf[i]);
491 }
492 local_buf[i] = '\0';
493 if ((i == 0) || (i > 8)) {
494 rc = -ENAMETOOLONG;
495 goto out_buf;
496 }
497
498 down_write(&dcssblk_devices_sem);
499 dev_info = dcssblk_get_device_by_name(local_buf);
500 if (dev_info == NULL) {
501 up_write(&dcssblk_devices_sem);
502 PRINT_WARN("Segment %s is not loaded!\n", local_buf);
503 rc = -ENODEV;
504 goto out_buf;
505 }
506 if (atomic_read(&dev_info->use_count) != 0) {
507 up_write(&dcssblk_devices_sem);
508 PRINT_WARN("Segment %s is in use!\n", local_buf);
509 rc = -EBUSY;
510 goto out_buf;
511 }
512 list_del(&dev_info->lh);
513
514 del_gendisk(dev_info->gd);
1312f40e 515 blk_cleanup_queue(dev_info->dcssblk_queue);
1da177e4
LT
516 dev_info->gd->queue = NULL;
517 put_disk(dev_info->gd);
518 device_unregister(&dev_info->dev);
519 segment_unload(dev_info->segment_name);
520 PRINT_DEBUG("Segment %s unloaded successfully\n",
521 dev_info->segment_name);
522 put_device(&dev_info->dev);
523 up_write(&dcssblk_devices_sem);
524
525 rc = count;
526out_buf:
527 kfree(local_buf);
528 return rc;
529}
530
531static int
532dcssblk_open(struct inode *inode, struct file *filp)
533{
534 struct dcssblk_dev_info *dev_info;
535 int rc;
536
537 dev_info = inode->i_bdev->bd_disk->private_data;
538 if (NULL == dev_info) {
539 rc = -ENODEV;
540 goto out;
541 }
542 atomic_inc(&dev_info->use_count);
543 inode->i_bdev->bd_block_size = 4096;
544 rc = 0;
545out:
546 return rc;
547}
548
549static int
550dcssblk_release(struct inode *inode, struct file *filp)
551{
552 struct dcssblk_dev_info *dev_info;
553 int rc;
554
555 dev_info = inode->i_bdev->bd_disk->private_data;
556 if (NULL == dev_info) {
557 rc = -ENODEV;
558 goto out;
559 }
560 down_write(&dcssblk_devices_sem);
561 if (atomic_dec_and_test(&dev_info->use_count)
562 && (dev_info->save_pending)) {
563 PRINT_INFO("Segment %s became idle and is being saved now\n",
564 dev_info->segment_name);
565 segment_save(dev_info->segment_name);
566 dev_info->save_pending = 0;
567 }
568 up_write(&dcssblk_devices_sem);
569 rc = 0;
570out:
571 return rc;
572}
573
574static int
165125e1 575dcssblk_make_request(struct request_queue *q, struct bio *bio)
1da177e4
LT
576{
577 struct dcssblk_dev_info *dev_info;
578 struct bio_vec *bvec;
579 unsigned long index;
580 unsigned long page_addr;
581 unsigned long source_addr;
582 unsigned long bytes_done;
583 int i;
584
585 bytes_done = 0;
586 dev_info = bio->bi_bdev->bd_disk->private_data;
587 if (dev_info == NULL)
588 goto fail;
589 if ((bio->bi_sector & 7) != 0 || (bio->bi_size & 4095) != 0)
590 /* Request is not page-aligned. */
591 goto fail;
592 if (((bio->bi_size >> 9) + bio->bi_sector)
593 > get_capacity(bio->bi_bdev->bd_disk)) {
594 /* Request beyond end of DCSS segment. */
595 goto fail;
596 }
420edbcc
CO
597 /* verify data transfer direction */
598 if (dev_info->is_shared) {
599 switch (dev_info->segment_type) {
600 case SEG_TYPE_SR:
601 case SEG_TYPE_ER:
602 case SEG_TYPE_SC:
603 /* cannot write to these segments */
604 if (bio_data_dir(bio) == WRITE) {
605 PRINT_WARN("rejecting write to ro segment %s\n", dev_info->dev.bus_id);
606 goto fail;
607 }
608 }
609 }
610
1da177e4
LT
611 index = (bio->bi_sector >> 3);
612 bio_for_each_segment(bvec, bio, i) {
613 page_addr = (unsigned long)
614 page_address(bvec->bv_page) + bvec->bv_offset;
615 source_addr = dev_info->start + (index<<12) + bytes_done;
39f73b28 616 if (unlikely((page_addr & 4095) != 0) || (bvec->bv_len & 4095) != 0)
1da177e4
LT
617 // More paranoia.
618 goto fail;
619 if (bio_data_dir(bio) == READ) {
620 memcpy((void*)page_addr, (void*)source_addr,
621 bvec->bv_len);
622 } else {
623 memcpy((void*)source_addr, (void*)page_addr,
624 bvec->bv_len);
625 }
626 bytes_done += bvec->bv_len;
627 }
6712ecf8 628 bio_endio(bio, 0);
1da177e4
LT
629 return 0;
630fail:
6712ecf8 631 bio_io_error(bio);
420edbcc
CO
632 return 0;
633}
634
635static int
636dcssblk_direct_access (struct block_device *bdev, sector_t secnum,
30afcb4b 637 void **kaddr, unsigned long *pfn)
420edbcc
CO
638{
639 struct dcssblk_dev_info *dev_info;
640 unsigned long pgoff;
641
642 dev_info = bdev->bd_disk->private_data;
643 if (!dev_info)
644 return -ENODEV;
645 if (secnum % (PAGE_SIZE/512))
646 return -EINVAL;
647 pgoff = secnum / (PAGE_SIZE / 512);
648 if ((pgoff+1)*PAGE_SIZE-1 > dev_info->end - dev_info->start)
649 return -ERANGE;
30afcb4b
JH
650 *kaddr = (void *) (dev_info->start+pgoff*PAGE_SIZE);
651 *pfn = virt_to_phys(*kaddr) >> PAGE_SHIFT;
652
1da177e4
LT
653 return 0;
654}
655
656static void
657dcssblk_check_params(void)
658{
659 int rc, i, j, k;
660 char buf[9];
661 struct dcssblk_dev_info *dev_info;
662
663 for (i = 0; (i < DCSSBLK_PARM_LEN) && (dcssblk_segments[i] != '\0');
664 i++) {
665 for (j = i; (dcssblk_segments[j] != ',') &&
666 (dcssblk_segments[j] != '\0') &&
667 (dcssblk_segments[j] != '(') &&
668 (j - i) < 8; j++)
669 {
670 buf[j-i] = dcssblk_segments[j];
671 }
672 buf[j-i] = '\0';
f901e5d1 673 rc = dcssblk_add_store(dcssblk_root_dev, NULL, buf, j-i);
1da177e4
LT
674 if ((rc >= 0) && (dcssblk_segments[j] == '(')) {
675 for (k = 0; buf[k] != '\0'; k++)
676 buf[k] = toupper(buf[k]);
677 if (!strncmp(&dcssblk_segments[j], "(local)", 7)) {
678 down_read(&dcssblk_devices_sem);
679 dev_info = dcssblk_get_device_by_name(buf);
680 up_read(&dcssblk_devices_sem);
681 if (dev_info)
682 dcssblk_shared_store(&dev_info->dev,
f901e5d1 683 NULL, "0\n", 2);
1da177e4
LT
684 }
685 }
686 while ((dcssblk_segments[j] != ',') &&
687 (dcssblk_segments[j] != '\0'))
688 {
689 j++;
690 }
691 if (dcssblk_segments[j] == '\0')
692 break;
693 i = j;
694 }
695}
696
697/*
698 * The init/exit functions.
699 */
700static void __exit
701dcssblk_exit(void)
702{
1da177e4 703 s390_root_dev_unregister(dcssblk_root_dev);
00d59405 704 unregister_blkdev(dcssblk_major, DCSSBLK_NAME);
1da177e4
LT
705}
706
707static int __init
708dcssblk_init(void)
709{
710 int rc;
711
1da177e4 712 dcssblk_root_dev = s390_root_dev_register("dcssblk");
ded77fb4 713 if (IS_ERR(dcssblk_root_dev))
1da177e4 714 return PTR_ERR(dcssblk_root_dev);
1da177e4
LT
715 rc = device_create_file(dcssblk_root_dev, &dev_attr_add);
716 if (rc) {
1da177e4
LT
717 s390_root_dev_unregister(dcssblk_root_dev);
718 return rc;
719 }
720 rc = device_create_file(dcssblk_root_dev, &dev_attr_remove);
721 if (rc) {
1da177e4
LT
722 s390_root_dev_unregister(dcssblk_root_dev);
723 return rc;
724 }
725 rc = register_blkdev(0, DCSSBLK_NAME);
726 if (rc < 0) {
1da177e4
LT
727 s390_root_dev_unregister(dcssblk_root_dev);
728 return rc;
729 }
730 dcssblk_major = rc;
731 init_rwsem(&dcssblk_devices_sem);
732
733 dcssblk_check_params();
734
1da177e4
LT
735 return 0;
736}
737
738module_init(dcssblk_init);
739module_exit(dcssblk_exit);
740
741module_param_string(segments, dcssblk_segments, DCSSBLK_PARM_LEN, 0444);
742MODULE_PARM_DESC(segments, "Name of DCSS segment(s) to be loaded, "
743 "comma-separated list, each name max. 8 chars.\n"
744 "Adding \"(local)\" to segment name equals echoing 0 to "
745 "/sys/devices/dcssblk/<segment name>/shared after loading "
746 "the segment - \n"
747 "e.g. segments=\"mydcss1,mydcss2,mydcss3(local)\"");
748
749MODULE_LICENSE("GPL");