]>
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> | |
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 | 38 | static int dcssblk_direct_access(struct block_device *bdev, sector_t secnum, |
30afcb4b | 39 | void **kaddr, unsigned long *pfn); |
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) | |
f331c029 | 117 | if (minor == MINOR(disk_devt(entry->gd))) |
1da177e4 LT |
118 | found++; |
119 | if (!found) break; // got unused minor | |
120 | } | |
121 | if (found) | |
122 | return -EBUSY; | |
123 | dev_info->gd->first_minor = minor; | |
124 | return 0; | |
125 | } | |
126 | ||
127 | /* | |
128 | * get the struct dcssblk_dev_info from dcssblk_devices | |
129 | * for the given name. | |
130 | * down_read(&dcssblk_devices_sem) must be held. | |
131 | */ | |
132 | static struct dcssblk_dev_info * | |
133 | dcssblk_get_device_by_name(char *name) | |
134 | { | |
135 | struct dcssblk_dev_info *entry; | |
136 | ||
137 | list_for_each_entry(entry, &dcssblk_devices, lh) { | |
138 | if (!strcmp(name, entry->segment_name)) { | |
139 | return entry; | |
140 | } | |
141 | } | |
142 | return NULL; | |
143 | } | |
144 | ||
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 | ||
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 | ||
222 | removeseg: | |
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 |
232 | out: |
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 | */ | |
244 | static ssize_t | |
e404e274 | 245 | dcssblk_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 | ||
253 | static ssize_t | |
e404e274 | 254 | dcssblk_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 | */ | |
296 | static ssize_t | |
e404e274 | 297 | dcssblk_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", | |
f331c029 | 400 | MINOR(disk_devt(dev_info->gd))); |
1da177e4 LT |
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 | ||
442 | unregister_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; | |
452 | list_del: | |
453 | list_del(&dev_info->lh); | |
454 | up_write(&dcssblk_devices_sem); | |
455 | unload_seg: | |
456 | segment_unload(local_buf); | |
457 | dealloc_gendisk: | |
1312f40e | 458 | blk_cleanup_queue(dev_info->dcssblk_queue); |
1da177e4 LT |
459 | dev_info->gd->queue = NULL; |
460 | put_disk(dev_info->gd); | |
461 | free_dev_info: | |
462 | kfree(dev_info); | |
463 | out: | |
464 | kfree(local_buf); | |
465 | out_nobuf: | |
466 | return rc; | |
467 | } | |
468 | ||
469 | /* | |
470 | * device attribute for removing devices | |
471 | */ | |
472 | static ssize_t | |
e404e274 | 473 | dcssblk_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; | |
526 | out_buf: | |
527 | kfree(local_buf); | |
528 | return rc; | |
529 | } | |
530 | ||
531 | static int | |
532 | dcssblk_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; | |
545 | out: | |
546 | return rc; | |
547 | } | |
548 | ||
549 | static int | |
550 | dcssblk_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; | |
570 | out: | |
571 | return rc; | |
572 | } | |
573 | ||
574 | static int | |
165125e1 | 575 | dcssblk_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; |
630 | fail: | |
6712ecf8 | 631 | bio_io_error(bio); |
420edbcc CO |
632 | return 0; |
633 | } | |
634 | ||
635 | static int | |
636 | dcssblk_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 | ||
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 | 703 | s390_root_dev_unregister(dcssblk_root_dev); |
00d59405 | 704 | unregister_blkdev(dcssblk_major, DCSSBLK_NAME); |
1da177e4 LT |
705 | } |
706 | ||
707 | static int __init | |
708 | dcssblk_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 | ||
738 | module_init(dcssblk_init); | |
739 | module_exit(dcssblk_exit); | |
740 | ||
741 | module_param_string(segments, dcssblk_segments, DCSSBLK_PARM_LEN, 0444); | |
742 | MODULE_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 | ||
749 | MODULE_LICENSE("GPL"); |