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 | ||
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> | |
18 | #include <asm/ccwdev.h> // for s390_root_dev_(un)register() | |
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 | ||
35 | static int dcssblk_open(struct inode *inode, struct file *filp); | |
36 | static int dcssblk_release(struct inode *inode, struct file *filp); | |
37 | static int dcssblk_make_request(struct request_queue *q, struct bio *bio); | |
420edbcc CO |
38 | static int dcssblk_direct_access(struct block_device *bdev, sector_t secnum, |
39 | unsigned long *data); | |
1da177e4 LT |
40 | |
41 | static char dcssblk_segments[DCSSBLK_PARM_LEN] = "\0"; | |
42 | ||
43 | static int dcssblk_major; | |
44 | static 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 | 51 | static ssize_t dcssblk_add_store(struct device * dev, struct device_attribute *attr, const char * buf, |
1da177e4 | 52 | size_t count); |
e404e274 | 53 | static ssize_t dcssblk_remove_store(struct device * dev, struct device_attribute *attr, const char * buf, |
1da177e4 | 54 | size_t count); |
e404e274 | 55 | static ssize_t dcssblk_save_store(struct device * dev, struct device_attribute *attr, const char * buf, |
1da177e4 | 56 | size_t count); |
e404e274 YI |
57 | static ssize_t dcssblk_save_show(struct device *dev, struct device_attribute *attr, char *buf); |
58 | static ssize_t dcssblk_shared_store(struct device * dev, struct device_attribute *attr, const char * buf, | |
1da177e4 | 59 | size_t count); |
e404e274 | 60 | static ssize_t dcssblk_shared_show(struct device *dev, struct device_attribute *attr, char *buf); |
1da177e4 LT |
61 | |
62 | static DEVICE_ATTR(add, S_IWUSR, NULL, dcssblk_add_store); | |
63 | static DEVICE_ATTR(remove, S_IWUSR, NULL, dcssblk_remove_store); | |
64 | static DEVICE_ATTR(save, S_IWUSR | S_IRUGO, dcssblk_save_show, | |
65 | dcssblk_save_store); | |
66 | static DEVICE_ATTR(shared, S_IWUSR | S_IRUGO, dcssblk_shared_show, | |
67 | dcssblk_shared_store); | |
68 | ||
69 | static struct device *dcssblk_root_dev; | |
70 | ||
71 | struct 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 | ||
85 | static struct list_head dcssblk_devices = LIST_HEAD_INIT(dcssblk_devices); | |
86 | static struct rw_semaphore dcssblk_devices_sem; | |
87 | ||
88 | /* | |
89 | * release function for segment device. | |
90 | */ | |
91 | static void | |
92 | dcssblk_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 | */ | |
105 | static inline int | |
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) | |
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 | */ | |
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 | ||
145 | /* | |
146 | * print appropriate error message for segment_load()/segment_type() | |
147 | * return code | |
148 | */ | |
149 | static void | |
150 | dcssblk_segment_warn(int rc, char* seg_name) | |
151 | { | |
152 | switch (rc) { | |
153 | case -ENOENT: | |
154 | PRINT_WARN("cannot load/query segment %s, does not exist\n", | |
155 | seg_name); | |
156 | break; | |
157 | case -ENOSYS: | |
158 | PRINT_WARN("cannot load/query segment %s, not running on VM\n", | |
159 | seg_name); | |
160 | break; | |
161 | case -EIO: | |
162 | PRINT_WARN("cannot load/query segment %s, hardware error\n", | |
163 | seg_name); | |
164 | break; | |
165 | case -ENOTSUPP: | |
166 | PRINT_WARN("cannot load/query segment %s, is a multi-part " | |
167 | "segment\n", seg_name); | |
168 | break; | |
169 | case -ENOSPC: | |
170 | PRINT_WARN("cannot load/query segment %s, overlaps with " | |
171 | "storage\n", seg_name); | |
172 | break; | |
173 | case -EBUSY: | |
174 | PRINT_WARN("cannot load/query segment %s, overlaps with " | |
175 | "already loaded dcss\n", seg_name); | |
176 | break; | |
177 | case -EPERM: | |
178 | PRINT_WARN("cannot load/query segment %s, already loaded in " | |
179 | "incompatible mode\n", seg_name); | |
180 | break; | |
181 | case -ENOMEM: | |
182 | PRINT_WARN("cannot load/query segment %s, out of memory\n", | |
183 | seg_name); | |
184 | break; | |
185 | case -ERANGE: | |
186 | PRINT_WARN("cannot load/query segment %s, exceeds kernel " | |
187 | "mapping range\n", seg_name); | |
188 | break; | |
189 | default: | |
190 | PRINT_WARN("cannot load/query segment %s, return value %i\n", | |
191 | seg_name, rc); | |
192 | break; | |
193 | } | |
194 | } | |
195 | ||
196 | /* | |
197 | * device attribute for switching shared/nonshared (exclusive) | |
198 | * operation (show + store) | |
199 | */ | |
200 | static ssize_t | |
e404e274 | 201 | dcssblk_shared_show(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
202 | { |
203 | struct dcssblk_dev_info *dev_info; | |
204 | ||
205 | dev_info = container_of(dev, struct dcssblk_dev_info, dev); | |
206 | return sprintf(buf, dev_info->is_shared ? "1\n" : "0\n"); | |
207 | } | |
208 | ||
209 | static ssize_t | |
e404e274 | 210 | dcssblk_shared_store(struct device *dev, struct device_attribute *attr, const char *inbuf, size_t count) |
1da177e4 LT |
211 | { |
212 | struct dcssblk_dev_info *dev_info; | |
213 | int rc; | |
214 | ||
215 | if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0')) { | |
216 | PRINT_WARN("Invalid value, must be 0 or 1\n"); | |
217 | return -EINVAL; | |
218 | } | |
219 | down_write(&dcssblk_devices_sem); | |
220 | dev_info = container_of(dev, struct dcssblk_dev_info, dev); | |
221 | if (atomic_read(&dev_info->use_count)) { | |
222 | PRINT_ERR("share: segment %s is busy!\n", | |
223 | dev_info->segment_name); | |
224 | rc = -EBUSY; | |
225 | goto out; | |
226 | } | |
227 | if (inbuf[0] == '1') { | |
228 | // reload segment in shared mode | |
229 | rc = segment_modify_shared(dev_info->segment_name, | |
230 | SEGMENT_SHARED); | |
231 | if (rc < 0) { | |
232 | BUG_ON(rc == -EINVAL); | |
233 | if (rc == -EIO || rc == -ENOENT) | |
234 | goto removeseg; | |
235 | } else { | |
236 | dev_info->is_shared = 1; | |
237 | switch (dev_info->segment_type) { | |
238 | case SEG_TYPE_SR: | |
239 | case SEG_TYPE_ER: | |
240 | case SEG_TYPE_SC: | |
241 | set_disk_ro(dev_info->gd,1); | |
242 | } | |
243 | } | |
244 | } else if (inbuf[0] == '0') { | |
245 | // reload segment in exclusive mode | |
246 | if (dev_info->segment_type == SEG_TYPE_SC) { | |
247 | PRINT_ERR("Segment type SC (%s) cannot be loaded in " | |
248 | "non-shared mode\n", dev_info->segment_name); | |
249 | rc = -EINVAL; | |
250 | goto out; | |
251 | } | |
252 | rc = segment_modify_shared(dev_info->segment_name, | |
253 | SEGMENT_EXCLUSIVE); | |
254 | if (rc < 0) { | |
255 | BUG_ON(rc == -EINVAL); | |
256 | if (rc == -EIO || rc == -ENOENT) | |
257 | goto removeseg; | |
258 | } else { | |
259 | dev_info->is_shared = 0; | |
260 | set_disk_ro(dev_info->gd, 0); | |
261 | } | |
262 | } else { | |
263 | PRINT_WARN("Invalid value, must be 0 or 1\n"); | |
264 | rc = -EINVAL; | |
265 | goto out; | |
266 | } | |
267 | rc = count; | |
268 | goto out; | |
269 | ||
270 | removeseg: | |
271 | PRINT_ERR("Could not reload segment %s, removing it now!\n", | |
272 | dev_info->segment_name); | |
273 | list_del(&dev_info->lh); | |
274 | ||
275 | del_gendisk(dev_info->gd); | |
276 | blk_put_queue(dev_info->dcssblk_queue); | |
277 | dev_info->gd->queue = NULL; | |
278 | put_disk(dev_info->gd); | |
279 | device_unregister(dev); | |
280 | put_device(dev); | |
281 | out: | |
282 | up_write(&dcssblk_devices_sem); | |
283 | return rc; | |
284 | } | |
285 | ||
286 | /* | |
287 | * device attribute for save operation on current copy | |
288 | * of the segment. If the segment is busy, saving will | |
289 | * become pending until it gets released, which can be | |
290 | * undone by storing a non-true value to this entry. | |
291 | * (show + store) | |
292 | */ | |
293 | static ssize_t | |
e404e274 | 294 | dcssblk_save_show(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
295 | { |
296 | struct dcssblk_dev_info *dev_info; | |
297 | ||
298 | dev_info = container_of(dev, struct dcssblk_dev_info, dev); | |
299 | return sprintf(buf, dev_info->save_pending ? "1\n" : "0\n"); | |
300 | } | |
301 | ||
302 | static ssize_t | |
e404e274 | 303 | dcssblk_save_store(struct device *dev, struct device_attribute *attr, const char *inbuf, size_t count) |
1da177e4 LT |
304 | { |
305 | struct dcssblk_dev_info *dev_info; | |
306 | ||
307 | if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0')) { | |
308 | PRINT_WARN("Invalid value, must be 0 or 1\n"); | |
309 | return -EINVAL; | |
310 | } | |
311 | dev_info = container_of(dev, struct dcssblk_dev_info, dev); | |
312 | ||
313 | down_write(&dcssblk_devices_sem); | |
314 | if (inbuf[0] == '1') { | |
315 | if (atomic_read(&dev_info->use_count) == 0) { | |
316 | // device is idle => we save immediately | |
317 | PRINT_INFO("Saving segment %s\n", | |
318 | dev_info->segment_name); | |
319 | segment_save(dev_info->segment_name); | |
320 | } else { | |
321 | // device is busy => we save it when it becomes | |
322 | // idle in dcssblk_release | |
323 | PRINT_INFO("Segment %s is currently busy, it will " | |
324 | "be saved when it becomes idle...\n", | |
325 | dev_info->segment_name); | |
326 | dev_info->save_pending = 1; | |
327 | } | |
328 | } else if (inbuf[0] == '0') { | |
329 | if (dev_info->save_pending) { | |
330 | // device is busy & the user wants to undo his save | |
331 | // request | |
332 | dev_info->save_pending = 0; | |
333 | PRINT_INFO("Pending save for segment %s deactivated\n", | |
334 | dev_info->segment_name); | |
335 | } | |
336 | } else { | |
337 | up_write(&dcssblk_devices_sem); | |
338 | PRINT_WARN("Invalid value, must be 0 or 1\n"); | |
339 | return -EINVAL; | |
340 | } | |
341 | up_write(&dcssblk_devices_sem); | |
342 | return count; | |
343 | } | |
344 | ||
345 | /* | |
346 | * device attribute for adding devices | |
347 | */ | |
348 | static ssize_t | |
e404e274 | 349 | dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
1da177e4 LT |
350 | { |
351 | int rc, i; | |
352 | struct dcssblk_dev_info *dev_info; | |
353 | char *local_buf; | |
354 | unsigned long seg_byte_size; | |
355 | ||
356 | dev_info = NULL; | |
357 | if (dev != dcssblk_root_dev) { | |
358 | rc = -EINVAL; | |
359 | goto out_nobuf; | |
360 | } | |
361 | local_buf = kmalloc(count + 1, GFP_KERNEL); | |
362 | if (local_buf == NULL) { | |
363 | rc = -ENOMEM; | |
364 | goto out_nobuf; | |
365 | } | |
366 | /* | |
367 | * parse input | |
368 | */ | |
369 | for (i = 0; ((buf[i] != '\0') && (buf[i] != '\n') && i < count); i++) { | |
370 | local_buf[i] = toupper(buf[i]); | |
371 | } | |
372 | local_buf[i] = '\0'; | |
373 | if ((i == 0) || (i > 8)) { | |
374 | rc = -ENAMETOOLONG; | |
375 | goto out; | |
376 | } | |
377 | /* | |
378 | * already loaded? | |
379 | */ | |
380 | down_read(&dcssblk_devices_sem); | |
381 | dev_info = dcssblk_get_device_by_name(local_buf); | |
382 | up_read(&dcssblk_devices_sem); | |
383 | if (dev_info != NULL) { | |
384 | PRINT_WARN("Segment %s already loaded!\n", local_buf); | |
385 | rc = -EEXIST; | |
386 | goto out; | |
387 | } | |
388 | /* | |
389 | * get a struct dcssblk_dev_info | |
390 | */ | |
391 | dev_info = kmalloc(sizeof(struct dcssblk_dev_info), GFP_KERNEL); | |
392 | if (dev_info == NULL) { | |
393 | rc = -ENOMEM; | |
394 | goto out; | |
395 | } | |
396 | memset(dev_info, 0, sizeof(struct dcssblk_dev_info)); | |
397 | ||
398 | strcpy(dev_info->segment_name, local_buf); | |
399 | strlcpy(dev_info->dev.bus_id, local_buf, BUS_ID_SIZE); | |
400 | dev_info->dev.release = dcssblk_release_segment; | |
401 | INIT_LIST_HEAD(&dev_info->lh); | |
402 | ||
403 | dev_info->gd = alloc_disk(DCSSBLK_MINORS_PER_DISK); | |
404 | if (dev_info->gd == NULL) { | |
405 | rc = -ENOMEM; | |
406 | goto free_dev_info; | |
407 | } | |
408 | dev_info->gd->major = dcssblk_major; | |
409 | dev_info->gd->fops = &dcssblk_devops; | |
410 | dev_info->dcssblk_queue = blk_alloc_queue(GFP_KERNEL); | |
411 | dev_info->gd->queue = dev_info->dcssblk_queue; | |
412 | dev_info->gd->private_data = dev_info; | |
413 | dev_info->gd->driverfs_dev = &dev_info->dev; | |
414 | /* | |
415 | * load the segment | |
416 | */ | |
417 | rc = segment_load(local_buf, SEGMENT_SHARED, | |
418 | &dev_info->start, &dev_info->end); | |
419 | if (rc < 0) { | |
420 | dcssblk_segment_warn(rc, dev_info->segment_name); | |
421 | goto dealloc_gendisk; | |
422 | } | |
423 | seg_byte_size = (dev_info->end - dev_info->start + 1); | |
424 | set_capacity(dev_info->gd, seg_byte_size >> 9); // size in sectors | |
425 | PRINT_INFO("Loaded segment %s, size = %lu Byte, " | |
426 | "capacity = %lu (512 Byte) sectors\n", local_buf, | |
427 | seg_byte_size, seg_byte_size >> 9); | |
428 | ||
429 | dev_info->segment_type = rc; | |
430 | dev_info->save_pending = 0; | |
431 | dev_info->is_shared = 1; | |
432 | dev_info->dev.parent = dcssblk_root_dev; | |
433 | ||
434 | /* | |
435 | * get minor, add to list | |
436 | */ | |
437 | down_write(&dcssblk_devices_sem); | |
438 | rc = dcssblk_assign_free_minor(dev_info); | |
439 | if (rc) { | |
440 | up_write(&dcssblk_devices_sem); | |
441 | PRINT_ERR("No free minor number available! " | |
442 | "Unloading segment...\n"); | |
443 | goto unload_seg; | |
444 | } | |
445 | sprintf(dev_info->gd->disk_name, "dcssblk%d", | |
446 | dev_info->gd->first_minor); | |
447 | list_add_tail(&dev_info->lh, &dcssblk_devices); | |
448 | ||
449 | if (!try_module_get(THIS_MODULE)) { | |
450 | rc = -ENODEV; | |
451 | goto list_del; | |
452 | } | |
453 | /* | |
454 | * register the device | |
455 | */ | |
456 | rc = device_register(&dev_info->dev); | |
457 | if (rc) { | |
458 | PRINT_ERR("Segment %s could not be registered RC=%d\n", | |
459 | local_buf, rc); | |
460 | module_put(THIS_MODULE); | |
461 | goto list_del; | |
462 | } | |
463 | get_device(&dev_info->dev); | |
464 | rc = device_create_file(&dev_info->dev, &dev_attr_shared); | |
465 | if (rc) | |
466 | goto unregister_dev; | |
467 | rc = device_create_file(&dev_info->dev, &dev_attr_save); | |
468 | if (rc) | |
469 | goto unregister_dev; | |
470 | ||
471 | add_disk(dev_info->gd); | |
472 | ||
473 | blk_queue_make_request(dev_info->dcssblk_queue, dcssblk_make_request); | |
474 | blk_queue_hardsect_size(dev_info->dcssblk_queue, 4096); | |
475 | ||
476 | switch (dev_info->segment_type) { | |
477 | case SEG_TYPE_SR: | |
478 | case SEG_TYPE_ER: | |
479 | case SEG_TYPE_SC: | |
480 | set_disk_ro(dev_info->gd,1); | |
481 | break; | |
482 | default: | |
483 | set_disk_ro(dev_info->gd,0); | |
484 | break; | |
485 | } | |
486 | PRINT_DEBUG("Segment %s loaded successfully\n", local_buf); | |
487 | up_write(&dcssblk_devices_sem); | |
488 | rc = count; | |
489 | goto out; | |
490 | ||
491 | unregister_dev: | |
492 | PRINT_ERR("device_create_file() failed!\n"); | |
493 | list_del(&dev_info->lh); | |
494 | blk_put_queue(dev_info->dcssblk_queue); | |
495 | dev_info->gd->queue = NULL; | |
496 | put_disk(dev_info->gd); | |
497 | device_unregister(&dev_info->dev); | |
498 | segment_unload(dev_info->segment_name); | |
499 | put_device(&dev_info->dev); | |
500 | up_write(&dcssblk_devices_sem); | |
501 | goto out; | |
502 | list_del: | |
503 | list_del(&dev_info->lh); | |
504 | up_write(&dcssblk_devices_sem); | |
505 | unload_seg: | |
506 | segment_unload(local_buf); | |
507 | dealloc_gendisk: | |
508 | blk_put_queue(dev_info->dcssblk_queue); | |
509 | dev_info->gd->queue = NULL; | |
510 | put_disk(dev_info->gd); | |
511 | free_dev_info: | |
512 | kfree(dev_info); | |
513 | out: | |
514 | kfree(local_buf); | |
515 | out_nobuf: | |
516 | return rc; | |
517 | } | |
518 | ||
519 | /* | |
520 | * device attribute for removing devices | |
521 | */ | |
522 | static ssize_t | |
e404e274 | 523 | dcssblk_remove_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
1da177e4 LT |
524 | { |
525 | struct dcssblk_dev_info *dev_info; | |
526 | int rc, i; | |
527 | char *local_buf; | |
528 | ||
529 | if (dev != dcssblk_root_dev) { | |
530 | return -EINVAL; | |
531 | } | |
532 | local_buf = kmalloc(count + 1, GFP_KERNEL); | |
533 | if (local_buf == NULL) { | |
534 | return -ENOMEM; | |
535 | } | |
536 | /* | |
537 | * parse input | |
538 | */ | |
539 | for (i = 0; ((*(buf+i)!='\0') && (*(buf+i)!='\n') && i < count); i++) { | |
540 | local_buf[i] = toupper(buf[i]); | |
541 | } | |
542 | local_buf[i] = '\0'; | |
543 | if ((i == 0) || (i > 8)) { | |
544 | rc = -ENAMETOOLONG; | |
545 | goto out_buf; | |
546 | } | |
547 | ||
548 | down_write(&dcssblk_devices_sem); | |
549 | dev_info = dcssblk_get_device_by_name(local_buf); | |
550 | if (dev_info == NULL) { | |
551 | up_write(&dcssblk_devices_sem); | |
552 | PRINT_WARN("Segment %s is not loaded!\n", local_buf); | |
553 | rc = -ENODEV; | |
554 | goto out_buf; | |
555 | } | |
556 | if (atomic_read(&dev_info->use_count) != 0) { | |
557 | up_write(&dcssblk_devices_sem); | |
558 | PRINT_WARN("Segment %s is in use!\n", local_buf); | |
559 | rc = -EBUSY; | |
560 | goto out_buf; | |
561 | } | |
562 | list_del(&dev_info->lh); | |
563 | ||
564 | del_gendisk(dev_info->gd); | |
565 | blk_put_queue(dev_info->dcssblk_queue); | |
566 | dev_info->gd->queue = NULL; | |
567 | put_disk(dev_info->gd); | |
568 | device_unregister(&dev_info->dev); | |
569 | segment_unload(dev_info->segment_name); | |
570 | PRINT_DEBUG("Segment %s unloaded successfully\n", | |
571 | dev_info->segment_name); | |
572 | put_device(&dev_info->dev); | |
573 | up_write(&dcssblk_devices_sem); | |
574 | ||
575 | rc = count; | |
576 | out_buf: | |
577 | kfree(local_buf); | |
578 | return rc; | |
579 | } | |
580 | ||
581 | static int | |
582 | dcssblk_open(struct inode *inode, struct file *filp) | |
583 | { | |
584 | struct dcssblk_dev_info *dev_info; | |
585 | int rc; | |
586 | ||
587 | dev_info = inode->i_bdev->bd_disk->private_data; | |
588 | if (NULL == dev_info) { | |
589 | rc = -ENODEV; | |
590 | goto out; | |
591 | } | |
592 | atomic_inc(&dev_info->use_count); | |
593 | inode->i_bdev->bd_block_size = 4096; | |
594 | rc = 0; | |
595 | out: | |
596 | return rc; | |
597 | } | |
598 | ||
599 | static int | |
600 | dcssblk_release(struct inode *inode, struct file *filp) | |
601 | { | |
602 | struct dcssblk_dev_info *dev_info; | |
603 | int rc; | |
604 | ||
605 | dev_info = inode->i_bdev->bd_disk->private_data; | |
606 | if (NULL == dev_info) { | |
607 | rc = -ENODEV; | |
608 | goto out; | |
609 | } | |
610 | down_write(&dcssblk_devices_sem); | |
611 | if (atomic_dec_and_test(&dev_info->use_count) | |
612 | && (dev_info->save_pending)) { | |
613 | PRINT_INFO("Segment %s became idle and is being saved now\n", | |
614 | dev_info->segment_name); | |
615 | segment_save(dev_info->segment_name); | |
616 | dev_info->save_pending = 0; | |
617 | } | |
618 | up_write(&dcssblk_devices_sem); | |
619 | rc = 0; | |
620 | out: | |
621 | return rc; | |
622 | } | |
623 | ||
624 | static int | |
625 | dcssblk_make_request(request_queue_t *q, struct bio *bio) | |
626 | { | |
627 | struct dcssblk_dev_info *dev_info; | |
628 | struct bio_vec *bvec; | |
629 | unsigned long index; | |
630 | unsigned long page_addr; | |
631 | unsigned long source_addr; | |
632 | unsigned long bytes_done; | |
633 | int i; | |
634 | ||
635 | bytes_done = 0; | |
636 | dev_info = bio->bi_bdev->bd_disk->private_data; | |
637 | if (dev_info == NULL) | |
638 | goto fail; | |
639 | if ((bio->bi_sector & 7) != 0 || (bio->bi_size & 4095) != 0) | |
640 | /* Request is not page-aligned. */ | |
641 | goto fail; | |
642 | if (((bio->bi_size >> 9) + bio->bi_sector) | |
643 | > get_capacity(bio->bi_bdev->bd_disk)) { | |
644 | /* Request beyond end of DCSS segment. */ | |
645 | goto fail; | |
646 | } | |
420edbcc CO |
647 | /* verify data transfer direction */ |
648 | if (dev_info->is_shared) { | |
649 | switch (dev_info->segment_type) { | |
650 | case SEG_TYPE_SR: | |
651 | case SEG_TYPE_ER: | |
652 | case SEG_TYPE_SC: | |
653 | /* cannot write to these segments */ | |
654 | if (bio_data_dir(bio) == WRITE) { | |
655 | PRINT_WARN("rejecting write to ro segment %s\n", dev_info->dev.bus_id); | |
656 | goto fail; | |
657 | } | |
658 | } | |
659 | } | |
660 | ||
1da177e4 LT |
661 | index = (bio->bi_sector >> 3); |
662 | bio_for_each_segment(bvec, bio, i) { | |
663 | page_addr = (unsigned long) | |
664 | page_address(bvec->bv_page) + bvec->bv_offset; | |
665 | source_addr = dev_info->start + (index<<12) + bytes_done; | |
666 | if (unlikely(page_addr & 4095) != 0 || (bvec->bv_len & 4095) != 0) | |
667 | // More paranoia. | |
668 | goto fail; | |
669 | if (bio_data_dir(bio) == READ) { | |
670 | memcpy((void*)page_addr, (void*)source_addr, | |
671 | bvec->bv_len); | |
672 | } else { | |
673 | memcpy((void*)source_addr, (void*)page_addr, | |
674 | bvec->bv_len); | |
675 | } | |
676 | bytes_done += bvec->bv_len; | |
677 | } | |
678 | bio_endio(bio, bytes_done, 0); | |
679 | return 0; | |
680 | fail: | |
420edbcc CO |
681 | bio_io_error(bio, bio->bi_size); |
682 | return 0; | |
683 | } | |
684 | ||
685 | static int | |
686 | dcssblk_direct_access (struct block_device *bdev, sector_t secnum, | |
687 | unsigned long *data) | |
688 | { | |
689 | struct dcssblk_dev_info *dev_info; | |
690 | unsigned long pgoff; | |
691 | ||
692 | dev_info = bdev->bd_disk->private_data; | |
693 | if (!dev_info) | |
694 | return -ENODEV; | |
695 | if (secnum % (PAGE_SIZE/512)) | |
696 | return -EINVAL; | |
697 | pgoff = secnum / (PAGE_SIZE / 512); | |
698 | if ((pgoff+1)*PAGE_SIZE-1 > dev_info->end - dev_info->start) | |
699 | return -ERANGE; | |
700 | *data = (unsigned long) (dev_info->start+pgoff*PAGE_SIZE); | |
1da177e4 LT |
701 | return 0; |
702 | } | |
703 | ||
704 | static void | |
705 | dcssblk_check_params(void) | |
706 | { | |
707 | int rc, i, j, k; | |
708 | char buf[9]; | |
709 | struct dcssblk_dev_info *dev_info; | |
710 | ||
711 | for (i = 0; (i < DCSSBLK_PARM_LEN) && (dcssblk_segments[i] != '\0'); | |
712 | i++) { | |
713 | for (j = i; (dcssblk_segments[j] != ',') && | |
714 | (dcssblk_segments[j] != '\0') && | |
715 | (dcssblk_segments[j] != '(') && | |
716 | (j - i) < 8; j++) | |
717 | { | |
718 | buf[j-i] = dcssblk_segments[j]; | |
719 | } | |
720 | buf[j-i] = '\0'; | |
721 | rc = dcssblk_add_store(dcssblk_root_dev, buf, j-i); | |
722 | if ((rc >= 0) && (dcssblk_segments[j] == '(')) { | |
723 | for (k = 0; buf[k] != '\0'; k++) | |
724 | buf[k] = toupper(buf[k]); | |
725 | if (!strncmp(&dcssblk_segments[j], "(local)", 7)) { | |
726 | down_read(&dcssblk_devices_sem); | |
727 | dev_info = dcssblk_get_device_by_name(buf); | |
728 | up_read(&dcssblk_devices_sem); | |
729 | if (dev_info) | |
730 | dcssblk_shared_store(&dev_info->dev, | |
731 | "0\n", 2); | |
732 | } | |
733 | } | |
734 | while ((dcssblk_segments[j] != ',') && | |
735 | (dcssblk_segments[j] != '\0')) | |
736 | { | |
737 | j++; | |
738 | } | |
739 | if (dcssblk_segments[j] == '\0') | |
740 | break; | |
741 | i = j; | |
742 | } | |
743 | } | |
744 | ||
745 | /* | |
746 | * The init/exit functions. | |
747 | */ | |
748 | static void __exit | |
749 | dcssblk_exit(void) | |
750 | { | |
751 | int rc; | |
752 | ||
753 | PRINT_DEBUG("DCSSBLOCK EXIT...\n"); | |
754 | s390_root_dev_unregister(dcssblk_root_dev); | |
755 | rc = unregister_blkdev(dcssblk_major, DCSSBLK_NAME); | |
756 | if (rc) { | |
757 | PRINT_ERR("unregister_blkdev() failed!\n"); | |
758 | } | |
759 | PRINT_DEBUG("...finished!\n"); | |
760 | } | |
761 | ||
762 | static int __init | |
763 | dcssblk_init(void) | |
764 | { | |
765 | int rc; | |
766 | ||
767 | PRINT_DEBUG("DCSSBLOCK INIT...\n"); | |
768 | dcssblk_root_dev = s390_root_dev_register("dcssblk"); | |
769 | if (IS_ERR(dcssblk_root_dev)) { | |
770 | PRINT_ERR("device_register() failed!\n"); | |
771 | return PTR_ERR(dcssblk_root_dev); | |
772 | } | |
773 | rc = device_create_file(dcssblk_root_dev, &dev_attr_add); | |
774 | if (rc) { | |
775 | PRINT_ERR("device_create_file(add) failed!\n"); | |
776 | s390_root_dev_unregister(dcssblk_root_dev); | |
777 | return rc; | |
778 | } | |
779 | rc = device_create_file(dcssblk_root_dev, &dev_attr_remove); | |
780 | if (rc) { | |
781 | PRINT_ERR("device_create_file(remove) failed!\n"); | |
782 | s390_root_dev_unregister(dcssblk_root_dev); | |
783 | return rc; | |
784 | } | |
785 | rc = register_blkdev(0, DCSSBLK_NAME); | |
786 | if (rc < 0) { | |
787 | PRINT_ERR("Can't get dynamic major!\n"); | |
788 | s390_root_dev_unregister(dcssblk_root_dev); | |
789 | return rc; | |
790 | } | |
791 | dcssblk_major = rc; | |
792 | init_rwsem(&dcssblk_devices_sem); | |
793 | ||
794 | dcssblk_check_params(); | |
795 | ||
796 | PRINT_DEBUG("...finished!\n"); | |
797 | return 0; | |
798 | } | |
799 | ||
800 | module_init(dcssblk_init); | |
801 | module_exit(dcssblk_exit); | |
802 | ||
803 | module_param_string(segments, dcssblk_segments, DCSSBLK_PARM_LEN, 0444); | |
804 | MODULE_PARM_DESC(segments, "Name of DCSS segment(s) to be loaded, " | |
805 | "comma-separated list, each name max. 8 chars.\n" | |
806 | "Adding \"(local)\" to segment name equals echoing 0 to " | |
807 | "/sys/devices/dcssblk/<segment name>/shared after loading " | |
808 | "the segment - \n" | |
809 | "e.g. segments=\"mydcss1,mydcss2,mydcss3(local)\""); | |
810 | ||
811 | MODULE_LICENSE("GPL"); |