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Commit | Line | Data |
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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 | ||
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 | ||
c11ca97e | 85 | static LIST_HEAD(dcssblk_devices); |
1da177e4 LT |
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 | */ | |
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) | |
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 | ||
931bb68b GS |
145 | static 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 | */ | |
155 | static ssize_t | |
e404e274 | 156 | dcssblk_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 | ||
164 | static ssize_t | |
e404e274 | 165 | dcssblk_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 | ||
170 | if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0')) { | |
171 | PRINT_WARN("Invalid value, must be 0 or 1\n"); | |
172 | return -EINVAL; | |
173 | } | |
174 | down_write(&dcssblk_devices_sem); | |
175 | dev_info = container_of(dev, struct dcssblk_dev_info, dev); | |
176 | if (atomic_read(&dev_info->use_count)) { | |
177 | PRINT_ERR("share: segment %s is busy!\n", | |
178 | dev_info->segment_name); | |
179 | rc = -EBUSY; | |
180 | goto out; | |
181 | } | |
182 | if (inbuf[0] == '1') { | |
183 | // reload segment in shared mode | |
184 | rc = segment_modify_shared(dev_info->segment_name, | |
185 | SEGMENT_SHARED); | |
186 | if (rc < 0) { | |
187 | BUG_ON(rc == -EINVAL); | |
444f0e54 | 188 | if (rc != -EAGAIN) |
1da177e4 LT |
189 | goto removeseg; |
190 | } else { | |
191 | dev_info->is_shared = 1; | |
192 | switch (dev_info->segment_type) { | |
193 | case SEG_TYPE_SR: | |
194 | case SEG_TYPE_ER: | |
195 | case SEG_TYPE_SC: | |
196 | set_disk_ro(dev_info->gd,1); | |
197 | } | |
198 | } | |
199 | } else if (inbuf[0] == '0') { | |
200 | // reload segment in exclusive mode | |
201 | if (dev_info->segment_type == SEG_TYPE_SC) { | |
202 | PRINT_ERR("Segment type SC (%s) cannot be loaded in " | |
203 | "non-shared mode\n", dev_info->segment_name); | |
204 | rc = -EINVAL; | |
205 | goto out; | |
206 | } | |
207 | rc = segment_modify_shared(dev_info->segment_name, | |
208 | SEGMENT_EXCLUSIVE); | |
209 | if (rc < 0) { | |
210 | BUG_ON(rc == -EINVAL); | |
444f0e54 | 211 | if (rc != -EAGAIN) |
1da177e4 LT |
212 | goto removeseg; |
213 | } else { | |
214 | dev_info->is_shared = 0; | |
215 | set_disk_ro(dev_info->gd, 0); | |
216 | } | |
217 | } else { | |
218 | PRINT_WARN("Invalid value, must be 0 or 1\n"); | |
219 | rc = -EINVAL; | |
220 | goto out; | |
221 | } | |
222 | rc = count; | |
223 | goto out; | |
224 | ||
225 | removeseg: | |
226 | PRINT_ERR("Could not reload segment %s, removing it now!\n", | |
227 | dev_info->segment_name); | |
228 | list_del(&dev_info->lh); | |
229 | ||
230 | del_gendisk(dev_info->gd); | |
1312f40e | 231 | blk_cleanup_queue(dev_info->dcssblk_queue); |
1da177e4 LT |
232 | dev_info->gd->queue = NULL; |
233 | put_disk(dev_info->gd); | |
931bb68b | 234 | rc = device_schedule_callback(dev, dcssblk_unregister_callback); |
1da177e4 LT |
235 | out: |
236 | up_write(&dcssblk_devices_sem); | |
237 | return rc; | |
238 | } | |
239 | ||
240 | /* | |
241 | * device attribute for save operation on current copy | |
242 | * of the segment. If the segment is busy, saving will | |
243 | * become pending until it gets released, which can be | |
244 | * undone by storing a non-true value to this entry. | |
245 | * (show + store) | |
246 | */ | |
247 | static ssize_t | |
e404e274 | 248 | dcssblk_save_show(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
249 | { |
250 | struct dcssblk_dev_info *dev_info; | |
251 | ||
252 | dev_info = container_of(dev, struct dcssblk_dev_info, dev); | |
253 | return sprintf(buf, dev_info->save_pending ? "1\n" : "0\n"); | |
254 | } | |
255 | ||
256 | static ssize_t | |
e404e274 | 257 | dcssblk_save_store(struct device *dev, struct device_attribute *attr, const char *inbuf, size_t count) |
1da177e4 LT |
258 | { |
259 | struct dcssblk_dev_info *dev_info; | |
260 | ||
261 | if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0')) { | |
262 | PRINT_WARN("Invalid value, must be 0 or 1\n"); | |
263 | return -EINVAL; | |
264 | } | |
265 | dev_info = container_of(dev, struct dcssblk_dev_info, dev); | |
266 | ||
267 | down_write(&dcssblk_devices_sem); | |
268 | if (inbuf[0] == '1') { | |
269 | if (atomic_read(&dev_info->use_count) == 0) { | |
270 | // device is idle => we save immediately | |
271 | PRINT_INFO("Saving segment %s\n", | |
272 | dev_info->segment_name); | |
273 | segment_save(dev_info->segment_name); | |
274 | } else { | |
275 | // device is busy => we save it when it becomes | |
276 | // idle in dcssblk_release | |
277 | PRINT_INFO("Segment %s is currently busy, it will " | |
278 | "be saved when it becomes idle...\n", | |
279 | dev_info->segment_name); | |
280 | dev_info->save_pending = 1; | |
281 | } | |
282 | } else if (inbuf[0] == '0') { | |
283 | if (dev_info->save_pending) { | |
284 | // device is busy & the user wants to undo his save | |
285 | // request | |
286 | dev_info->save_pending = 0; | |
287 | PRINT_INFO("Pending save for segment %s deactivated\n", | |
288 | dev_info->segment_name); | |
289 | } | |
290 | } else { | |
291 | up_write(&dcssblk_devices_sem); | |
292 | PRINT_WARN("Invalid value, must be 0 or 1\n"); | |
293 | return -EINVAL; | |
294 | } | |
295 | up_write(&dcssblk_devices_sem); | |
296 | return count; | |
297 | } | |
298 | ||
299 | /* | |
300 | * device attribute for adding devices | |
301 | */ | |
302 | static ssize_t | |
e404e274 | 303 | dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
1da177e4 LT |
304 | { |
305 | int rc, i; | |
306 | struct dcssblk_dev_info *dev_info; | |
307 | char *local_buf; | |
308 | unsigned long seg_byte_size; | |
309 | ||
310 | dev_info = NULL; | |
311 | if (dev != dcssblk_root_dev) { | |
312 | rc = -EINVAL; | |
313 | goto out_nobuf; | |
314 | } | |
315 | local_buf = kmalloc(count + 1, GFP_KERNEL); | |
316 | if (local_buf == NULL) { | |
317 | rc = -ENOMEM; | |
318 | goto out_nobuf; | |
319 | } | |
320 | /* | |
321 | * parse input | |
322 | */ | |
323 | for (i = 0; ((buf[i] != '\0') && (buf[i] != '\n') && i < count); i++) { | |
324 | local_buf[i] = toupper(buf[i]); | |
325 | } | |
326 | local_buf[i] = '\0'; | |
327 | if ((i == 0) || (i > 8)) { | |
328 | rc = -ENAMETOOLONG; | |
329 | goto out; | |
330 | } | |
331 | /* | |
332 | * already loaded? | |
333 | */ | |
334 | down_read(&dcssblk_devices_sem); | |
335 | dev_info = dcssblk_get_device_by_name(local_buf); | |
336 | up_read(&dcssblk_devices_sem); | |
337 | if (dev_info != NULL) { | |
338 | PRINT_WARN("Segment %s already loaded!\n", local_buf); | |
339 | rc = -EEXIST; | |
340 | goto out; | |
341 | } | |
342 | /* | |
343 | * get a struct dcssblk_dev_info | |
344 | */ | |
88abaab4 | 345 | dev_info = kzalloc(sizeof(struct dcssblk_dev_info), GFP_KERNEL); |
1da177e4 LT |
346 | if (dev_info == NULL) { |
347 | rc = -ENOMEM; | |
348 | goto out; | |
349 | } | |
1da177e4 LT |
350 | |
351 | strcpy(dev_info->segment_name, local_buf); | |
352 | strlcpy(dev_info->dev.bus_id, local_buf, BUS_ID_SIZE); | |
353 | dev_info->dev.release = dcssblk_release_segment; | |
354 | INIT_LIST_HEAD(&dev_info->lh); | |
355 | ||
356 | dev_info->gd = alloc_disk(DCSSBLK_MINORS_PER_DISK); | |
357 | if (dev_info->gd == NULL) { | |
358 | rc = -ENOMEM; | |
359 | goto free_dev_info; | |
360 | } | |
361 | dev_info->gd->major = dcssblk_major; | |
362 | dev_info->gd->fops = &dcssblk_devops; | |
363 | dev_info->dcssblk_queue = blk_alloc_queue(GFP_KERNEL); | |
364 | dev_info->gd->queue = dev_info->dcssblk_queue; | |
365 | dev_info->gd->private_data = dev_info; | |
366 | dev_info->gd->driverfs_dev = &dev_info->dev; | |
c5411dba HC |
367 | blk_queue_make_request(dev_info->dcssblk_queue, dcssblk_make_request); |
368 | blk_queue_hardsect_size(dev_info->dcssblk_queue, 4096); | |
1da177e4 LT |
369 | /* |
370 | * load the segment | |
371 | */ | |
372 | rc = segment_load(local_buf, SEGMENT_SHARED, | |
373 | &dev_info->start, &dev_info->end); | |
374 | if (rc < 0) { | |
ca68305b | 375 | segment_warning(rc, dev_info->segment_name); |
1da177e4 LT |
376 | goto dealloc_gendisk; |
377 | } | |
378 | seg_byte_size = (dev_info->end - dev_info->start + 1); | |
379 | set_capacity(dev_info->gd, seg_byte_size >> 9); // size in sectors | |
380 | PRINT_INFO("Loaded segment %s, size = %lu Byte, " | |
381 | "capacity = %lu (512 Byte) sectors\n", local_buf, | |
382 | seg_byte_size, seg_byte_size >> 9); | |
383 | ||
384 | dev_info->segment_type = rc; | |
385 | dev_info->save_pending = 0; | |
386 | dev_info->is_shared = 1; | |
387 | dev_info->dev.parent = dcssblk_root_dev; | |
388 | ||
389 | /* | |
390 | * get minor, add to list | |
391 | */ | |
392 | down_write(&dcssblk_devices_sem); | |
393 | rc = dcssblk_assign_free_minor(dev_info); | |
394 | if (rc) { | |
395 | up_write(&dcssblk_devices_sem); | |
396 | PRINT_ERR("No free minor number available! " | |
397 | "Unloading segment...\n"); | |
398 | goto unload_seg; | |
399 | } | |
400 | sprintf(dev_info->gd->disk_name, "dcssblk%d", | |
401 | dev_info->gd->first_minor); | |
402 | list_add_tail(&dev_info->lh, &dcssblk_devices); | |
403 | ||
404 | if (!try_module_get(THIS_MODULE)) { | |
405 | rc = -ENODEV; | |
406 | goto list_del; | |
407 | } | |
408 | /* | |
409 | * register the device | |
410 | */ | |
411 | rc = device_register(&dev_info->dev); | |
412 | if (rc) { | |
413 | PRINT_ERR("Segment %s could not be registered RC=%d\n", | |
414 | local_buf, rc); | |
415 | module_put(THIS_MODULE); | |
416 | goto list_del; | |
417 | } | |
418 | get_device(&dev_info->dev); | |
419 | rc = device_create_file(&dev_info->dev, &dev_attr_shared); | |
420 | if (rc) | |
421 | goto unregister_dev; | |
422 | rc = device_create_file(&dev_info->dev, &dev_attr_save); | |
423 | if (rc) | |
424 | goto unregister_dev; | |
425 | ||
436d1bc7 CB |
426 | add_disk(dev_info->gd); |
427 | ||
1da177e4 LT |
428 | switch (dev_info->segment_type) { |
429 | case SEG_TYPE_SR: | |
430 | case SEG_TYPE_ER: | |
431 | case SEG_TYPE_SC: | |
432 | set_disk_ro(dev_info->gd,1); | |
433 | break; | |
434 | default: | |
435 | set_disk_ro(dev_info->gd,0); | |
436 | break; | |
437 | } | |
438 | PRINT_DEBUG("Segment %s loaded successfully\n", local_buf); | |
439 | up_write(&dcssblk_devices_sem); | |
440 | rc = count; | |
441 | goto out; | |
442 | ||
443 | unregister_dev: | |
444 | PRINT_ERR("device_create_file() failed!\n"); | |
445 | list_del(&dev_info->lh); | |
1312f40e | 446 | blk_cleanup_queue(dev_info->dcssblk_queue); |
1da177e4 LT |
447 | dev_info->gd->queue = NULL; |
448 | put_disk(dev_info->gd); | |
449 | device_unregister(&dev_info->dev); | |
450 | segment_unload(dev_info->segment_name); | |
451 | put_device(&dev_info->dev); | |
452 | up_write(&dcssblk_devices_sem); | |
453 | goto out; | |
454 | list_del: | |
455 | list_del(&dev_info->lh); | |
456 | up_write(&dcssblk_devices_sem); | |
457 | unload_seg: | |
458 | segment_unload(local_buf); | |
459 | dealloc_gendisk: | |
1312f40e | 460 | blk_cleanup_queue(dev_info->dcssblk_queue); |
1da177e4 LT |
461 | dev_info->gd->queue = NULL; |
462 | put_disk(dev_info->gd); | |
463 | free_dev_info: | |
464 | kfree(dev_info); | |
465 | out: | |
466 | kfree(local_buf); | |
467 | out_nobuf: | |
468 | return rc; | |
469 | } | |
470 | ||
471 | /* | |
472 | * device attribute for removing devices | |
473 | */ | |
474 | static ssize_t | |
e404e274 | 475 | dcssblk_remove_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
1da177e4 LT |
476 | { |
477 | struct dcssblk_dev_info *dev_info; | |
478 | int rc, i; | |
479 | char *local_buf; | |
480 | ||
481 | if (dev != dcssblk_root_dev) { | |
482 | return -EINVAL; | |
483 | } | |
484 | local_buf = kmalloc(count + 1, GFP_KERNEL); | |
485 | if (local_buf == NULL) { | |
486 | return -ENOMEM; | |
487 | } | |
488 | /* | |
489 | * parse input | |
490 | */ | |
491 | for (i = 0; ((*(buf+i)!='\0') && (*(buf+i)!='\n') && i < count); i++) { | |
492 | local_buf[i] = toupper(buf[i]); | |
493 | } | |
494 | local_buf[i] = '\0'; | |
495 | if ((i == 0) || (i > 8)) { | |
496 | rc = -ENAMETOOLONG; | |
497 | goto out_buf; | |
498 | } | |
499 | ||
500 | down_write(&dcssblk_devices_sem); | |
501 | dev_info = dcssblk_get_device_by_name(local_buf); | |
502 | if (dev_info == NULL) { | |
503 | up_write(&dcssblk_devices_sem); | |
504 | PRINT_WARN("Segment %s is not loaded!\n", local_buf); | |
505 | rc = -ENODEV; | |
506 | goto out_buf; | |
507 | } | |
508 | if (atomic_read(&dev_info->use_count) != 0) { | |
509 | up_write(&dcssblk_devices_sem); | |
510 | PRINT_WARN("Segment %s is in use!\n", local_buf); | |
511 | rc = -EBUSY; | |
512 | goto out_buf; | |
513 | } | |
514 | list_del(&dev_info->lh); | |
515 | ||
516 | del_gendisk(dev_info->gd); | |
1312f40e | 517 | blk_cleanup_queue(dev_info->dcssblk_queue); |
1da177e4 LT |
518 | dev_info->gd->queue = NULL; |
519 | put_disk(dev_info->gd); | |
520 | device_unregister(&dev_info->dev); | |
521 | segment_unload(dev_info->segment_name); | |
522 | PRINT_DEBUG("Segment %s unloaded successfully\n", | |
523 | dev_info->segment_name); | |
524 | put_device(&dev_info->dev); | |
525 | up_write(&dcssblk_devices_sem); | |
526 | ||
527 | rc = count; | |
528 | out_buf: | |
529 | kfree(local_buf); | |
530 | return rc; | |
531 | } | |
532 | ||
533 | static int | |
534 | dcssblk_open(struct inode *inode, struct file *filp) | |
535 | { | |
536 | struct dcssblk_dev_info *dev_info; | |
537 | int rc; | |
538 | ||
539 | dev_info = inode->i_bdev->bd_disk->private_data; | |
540 | if (NULL == dev_info) { | |
541 | rc = -ENODEV; | |
542 | goto out; | |
543 | } | |
544 | atomic_inc(&dev_info->use_count); | |
545 | inode->i_bdev->bd_block_size = 4096; | |
546 | rc = 0; | |
547 | out: | |
548 | return rc; | |
549 | } | |
550 | ||
551 | static int | |
552 | dcssblk_release(struct inode *inode, struct file *filp) | |
553 | { | |
554 | struct dcssblk_dev_info *dev_info; | |
555 | int rc; | |
556 | ||
557 | dev_info = inode->i_bdev->bd_disk->private_data; | |
558 | if (NULL == dev_info) { | |
559 | rc = -ENODEV; | |
560 | goto out; | |
561 | } | |
562 | down_write(&dcssblk_devices_sem); | |
563 | if (atomic_dec_and_test(&dev_info->use_count) | |
564 | && (dev_info->save_pending)) { | |
565 | PRINT_INFO("Segment %s became idle and is being saved now\n", | |
566 | dev_info->segment_name); | |
567 | segment_save(dev_info->segment_name); | |
568 | dev_info->save_pending = 0; | |
569 | } | |
570 | up_write(&dcssblk_devices_sem); | |
571 | rc = 0; | |
572 | out: | |
573 | return rc; | |
574 | } | |
575 | ||
576 | static int | |
165125e1 | 577 | dcssblk_make_request(struct request_queue *q, struct bio *bio) |
1da177e4 LT |
578 | { |
579 | struct dcssblk_dev_info *dev_info; | |
580 | struct bio_vec *bvec; | |
581 | unsigned long index; | |
582 | unsigned long page_addr; | |
583 | unsigned long source_addr; | |
584 | unsigned long bytes_done; | |
585 | int i; | |
586 | ||
587 | bytes_done = 0; | |
588 | dev_info = bio->bi_bdev->bd_disk->private_data; | |
589 | if (dev_info == NULL) | |
590 | goto fail; | |
591 | if ((bio->bi_sector & 7) != 0 || (bio->bi_size & 4095) != 0) | |
592 | /* Request is not page-aligned. */ | |
593 | goto fail; | |
594 | if (((bio->bi_size >> 9) + bio->bi_sector) | |
595 | > get_capacity(bio->bi_bdev->bd_disk)) { | |
596 | /* Request beyond end of DCSS segment. */ | |
597 | goto fail; | |
598 | } | |
420edbcc CO |
599 | /* verify data transfer direction */ |
600 | if (dev_info->is_shared) { | |
601 | switch (dev_info->segment_type) { | |
602 | case SEG_TYPE_SR: | |
603 | case SEG_TYPE_ER: | |
604 | case SEG_TYPE_SC: | |
605 | /* cannot write to these segments */ | |
606 | if (bio_data_dir(bio) == WRITE) { | |
607 | PRINT_WARN("rejecting write to ro segment %s\n", dev_info->dev.bus_id); | |
608 | goto fail; | |
609 | } | |
610 | } | |
611 | } | |
612 | ||
1da177e4 LT |
613 | index = (bio->bi_sector >> 3); |
614 | bio_for_each_segment(bvec, bio, i) { | |
615 | page_addr = (unsigned long) | |
616 | page_address(bvec->bv_page) + bvec->bv_offset; | |
617 | source_addr = dev_info->start + (index<<12) + bytes_done; | |
39f73b28 | 618 | if (unlikely((page_addr & 4095) != 0) || (bvec->bv_len & 4095) != 0) |
1da177e4 LT |
619 | // More paranoia. |
620 | goto fail; | |
621 | if (bio_data_dir(bio) == READ) { | |
622 | memcpy((void*)page_addr, (void*)source_addr, | |
623 | bvec->bv_len); | |
624 | } else { | |
625 | memcpy((void*)source_addr, (void*)page_addr, | |
626 | bvec->bv_len); | |
627 | } | |
628 | bytes_done += bvec->bv_len; | |
629 | } | |
6712ecf8 | 630 | bio_endio(bio, 0); |
1da177e4 LT |
631 | return 0; |
632 | fail: | |
6712ecf8 | 633 | bio_io_error(bio); |
420edbcc CO |
634 | return 0; |
635 | } | |
636 | ||
637 | static int | |
638 | dcssblk_direct_access (struct block_device *bdev, sector_t secnum, | |
639 | unsigned long *data) | |
640 | { | |
641 | struct dcssblk_dev_info *dev_info; | |
642 | unsigned long pgoff; | |
643 | ||
644 | dev_info = bdev->bd_disk->private_data; | |
645 | if (!dev_info) | |
646 | return -ENODEV; | |
647 | if (secnum % (PAGE_SIZE/512)) | |
648 | return -EINVAL; | |
649 | pgoff = secnum / (PAGE_SIZE / 512); | |
650 | if ((pgoff+1)*PAGE_SIZE-1 > dev_info->end - dev_info->start) | |
651 | return -ERANGE; | |
652 | *data = (unsigned long) (dev_info->start+pgoff*PAGE_SIZE); | |
1da177e4 LT |
653 | return 0; |
654 | } | |
655 | ||
656 | static void | |
657 | dcssblk_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 | */ | |
700 | static void __exit | |
701 | dcssblk_exit(void) | |
702 | { | |
1da177e4 LT |
703 | PRINT_DEBUG("DCSSBLOCK EXIT...\n"); |
704 | s390_root_dev_unregister(dcssblk_root_dev); | |
00d59405 | 705 | unregister_blkdev(dcssblk_major, DCSSBLK_NAME); |
1da177e4 LT |
706 | PRINT_DEBUG("...finished!\n"); |
707 | } | |
708 | ||
709 | static int __init | |
710 | dcssblk_init(void) | |
711 | { | |
712 | int rc; | |
713 | ||
714 | PRINT_DEBUG("DCSSBLOCK INIT...\n"); | |
715 | dcssblk_root_dev = s390_root_dev_register("dcssblk"); | |
716 | if (IS_ERR(dcssblk_root_dev)) { | |
717 | PRINT_ERR("device_register() failed!\n"); | |
718 | return PTR_ERR(dcssblk_root_dev); | |
719 | } | |
720 | rc = device_create_file(dcssblk_root_dev, &dev_attr_add); | |
721 | if (rc) { | |
722 | PRINT_ERR("device_create_file(add) failed!\n"); | |
723 | s390_root_dev_unregister(dcssblk_root_dev); | |
724 | return rc; | |
725 | } | |
726 | rc = device_create_file(dcssblk_root_dev, &dev_attr_remove); | |
727 | if (rc) { | |
728 | PRINT_ERR("device_create_file(remove) failed!\n"); | |
729 | s390_root_dev_unregister(dcssblk_root_dev); | |
730 | return rc; | |
731 | } | |
732 | rc = register_blkdev(0, DCSSBLK_NAME); | |
733 | if (rc < 0) { | |
734 | PRINT_ERR("Can't get dynamic major!\n"); | |
735 | s390_root_dev_unregister(dcssblk_root_dev); | |
736 | return rc; | |
737 | } | |
738 | dcssblk_major = rc; | |
739 | init_rwsem(&dcssblk_devices_sem); | |
740 | ||
741 | dcssblk_check_params(); | |
742 | ||
743 | PRINT_DEBUG("...finished!\n"); | |
744 | return 0; | |
745 | } | |
746 | ||
747 | module_init(dcssblk_init); | |
748 | module_exit(dcssblk_exit); | |
749 | ||
750 | module_param_string(segments, dcssblk_segments, DCSSBLK_PARM_LEN, 0444); | |
751 | MODULE_PARM_DESC(segments, "Name of DCSS segment(s) to be loaded, " | |
752 | "comma-separated list, each name max. 8 chars.\n" | |
753 | "Adding \"(local)\" to segment name equals echoing 0 to " | |
754 | "/sys/devices/dcssblk/<segment name>/shared after loading " | |
755 | "the segment - \n" | |
756 | "e.g. segments=\"mydcss1,mydcss2,mydcss3(local)\""); | |
757 | ||
758 | MODULE_LICENSE("GPL"); |