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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 | ||
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 | */ | |
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 | ||
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 | ||
931bb68b GS |
196 | static void dcssblk_unregister_callback(struct device *dev) |
197 | { | |
198 | device_unregister(dev); | |
199 | put_device(dev); | |
200 | } | |
201 | ||
1da177e4 LT |
202 | /* |
203 | * device attribute for switching shared/nonshared (exclusive) | |
204 | * operation (show + store) | |
205 | */ | |
206 | static ssize_t | |
e404e274 | 207 | dcssblk_shared_show(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
208 | { |
209 | struct dcssblk_dev_info *dev_info; | |
210 | ||
211 | dev_info = container_of(dev, struct dcssblk_dev_info, dev); | |
212 | return sprintf(buf, dev_info->is_shared ? "1\n" : "0\n"); | |
213 | } | |
214 | ||
215 | static ssize_t | |
e404e274 | 216 | dcssblk_shared_store(struct device *dev, struct device_attribute *attr, const char *inbuf, size_t count) |
1da177e4 LT |
217 | { |
218 | struct dcssblk_dev_info *dev_info; | |
219 | int rc; | |
220 | ||
221 | if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0')) { | |
222 | PRINT_WARN("Invalid value, must be 0 or 1\n"); | |
223 | return -EINVAL; | |
224 | } | |
225 | down_write(&dcssblk_devices_sem); | |
226 | dev_info = container_of(dev, struct dcssblk_dev_info, dev); | |
227 | if (atomic_read(&dev_info->use_count)) { | |
228 | PRINT_ERR("share: segment %s is busy!\n", | |
229 | dev_info->segment_name); | |
230 | rc = -EBUSY; | |
231 | goto out; | |
232 | } | |
233 | if (inbuf[0] == '1') { | |
234 | // reload segment in shared mode | |
235 | rc = segment_modify_shared(dev_info->segment_name, | |
236 | SEGMENT_SHARED); | |
237 | if (rc < 0) { | |
238 | BUG_ON(rc == -EINVAL); | |
444f0e54 | 239 | if (rc != -EAGAIN) |
1da177e4 LT |
240 | goto removeseg; |
241 | } else { | |
242 | dev_info->is_shared = 1; | |
243 | switch (dev_info->segment_type) { | |
244 | case SEG_TYPE_SR: | |
245 | case SEG_TYPE_ER: | |
246 | case SEG_TYPE_SC: | |
247 | set_disk_ro(dev_info->gd,1); | |
248 | } | |
249 | } | |
250 | } else if (inbuf[0] == '0') { | |
251 | // reload segment in exclusive mode | |
252 | if (dev_info->segment_type == SEG_TYPE_SC) { | |
253 | PRINT_ERR("Segment type SC (%s) cannot be loaded in " | |
254 | "non-shared mode\n", dev_info->segment_name); | |
255 | rc = -EINVAL; | |
256 | goto out; | |
257 | } | |
258 | rc = segment_modify_shared(dev_info->segment_name, | |
259 | SEGMENT_EXCLUSIVE); | |
260 | if (rc < 0) { | |
261 | BUG_ON(rc == -EINVAL); | |
444f0e54 | 262 | if (rc != -EAGAIN) |
1da177e4 LT |
263 | goto removeseg; |
264 | } else { | |
265 | dev_info->is_shared = 0; | |
266 | set_disk_ro(dev_info->gd, 0); | |
267 | } | |
268 | } else { | |
269 | PRINT_WARN("Invalid value, must be 0 or 1\n"); | |
270 | rc = -EINVAL; | |
271 | goto out; | |
272 | } | |
273 | rc = count; | |
274 | goto out; | |
275 | ||
276 | removeseg: | |
277 | PRINT_ERR("Could not reload segment %s, removing it now!\n", | |
278 | dev_info->segment_name); | |
279 | list_del(&dev_info->lh); | |
280 | ||
281 | del_gendisk(dev_info->gd); | |
1312f40e | 282 | blk_cleanup_queue(dev_info->dcssblk_queue); |
1da177e4 LT |
283 | dev_info->gd->queue = NULL; |
284 | put_disk(dev_info->gd); | |
931bb68b | 285 | rc = device_schedule_callback(dev, dcssblk_unregister_callback); |
1da177e4 LT |
286 | out: |
287 | up_write(&dcssblk_devices_sem); | |
288 | return rc; | |
289 | } | |
290 | ||
291 | /* | |
292 | * device attribute for save operation on current copy | |
293 | * of the segment. If the segment is busy, saving will | |
294 | * become pending until it gets released, which can be | |
295 | * undone by storing a non-true value to this entry. | |
296 | * (show + store) | |
297 | */ | |
298 | static ssize_t | |
e404e274 | 299 | dcssblk_save_show(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
300 | { |
301 | struct dcssblk_dev_info *dev_info; | |
302 | ||
303 | dev_info = container_of(dev, struct dcssblk_dev_info, dev); | |
304 | return sprintf(buf, dev_info->save_pending ? "1\n" : "0\n"); | |
305 | } | |
306 | ||
307 | static ssize_t | |
e404e274 | 308 | dcssblk_save_store(struct device *dev, struct device_attribute *attr, const char *inbuf, size_t count) |
1da177e4 LT |
309 | { |
310 | struct dcssblk_dev_info *dev_info; | |
311 | ||
312 | if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0')) { | |
313 | PRINT_WARN("Invalid value, must be 0 or 1\n"); | |
314 | return -EINVAL; | |
315 | } | |
316 | dev_info = container_of(dev, struct dcssblk_dev_info, dev); | |
317 | ||
318 | down_write(&dcssblk_devices_sem); | |
319 | if (inbuf[0] == '1') { | |
320 | if (atomic_read(&dev_info->use_count) == 0) { | |
321 | // device is idle => we save immediately | |
322 | PRINT_INFO("Saving segment %s\n", | |
323 | dev_info->segment_name); | |
324 | segment_save(dev_info->segment_name); | |
325 | } else { | |
326 | // device is busy => we save it when it becomes | |
327 | // idle in dcssblk_release | |
328 | PRINT_INFO("Segment %s is currently busy, it will " | |
329 | "be saved when it becomes idle...\n", | |
330 | dev_info->segment_name); | |
331 | dev_info->save_pending = 1; | |
332 | } | |
333 | } else if (inbuf[0] == '0') { | |
334 | if (dev_info->save_pending) { | |
335 | // device is busy & the user wants to undo his save | |
336 | // request | |
337 | dev_info->save_pending = 0; | |
338 | PRINT_INFO("Pending save for segment %s deactivated\n", | |
339 | dev_info->segment_name); | |
340 | } | |
341 | } else { | |
342 | up_write(&dcssblk_devices_sem); | |
343 | PRINT_WARN("Invalid value, must be 0 or 1\n"); | |
344 | return -EINVAL; | |
345 | } | |
346 | up_write(&dcssblk_devices_sem); | |
347 | return count; | |
348 | } | |
349 | ||
350 | /* | |
351 | * device attribute for adding devices | |
352 | */ | |
353 | static ssize_t | |
e404e274 | 354 | dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
1da177e4 LT |
355 | { |
356 | int rc, i; | |
357 | struct dcssblk_dev_info *dev_info; | |
358 | char *local_buf; | |
359 | unsigned long seg_byte_size; | |
360 | ||
361 | dev_info = NULL; | |
362 | if (dev != dcssblk_root_dev) { | |
363 | rc = -EINVAL; | |
364 | goto out_nobuf; | |
365 | } | |
366 | local_buf = kmalloc(count + 1, GFP_KERNEL); | |
367 | if (local_buf == NULL) { | |
368 | rc = -ENOMEM; | |
369 | goto out_nobuf; | |
370 | } | |
371 | /* | |
372 | * parse input | |
373 | */ | |
374 | for (i = 0; ((buf[i] != '\0') && (buf[i] != '\n') && i < count); i++) { | |
375 | local_buf[i] = toupper(buf[i]); | |
376 | } | |
377 | local_buf[i] = '\0'; | |
378 | if ((i == 0) || (i > 8)) { | |
379 | rc = -ENAMETOOLONG; | |
380 | goto out; | |
381 | } | |
382 | /* | |
383 | * already loaded? | |
384 | */ | |
385 | down_read(&dcssblk_devices_sem); | |
386 | dev_info = dcssblk_get_device_by_name(local_buf); | |
387 | up_read(&dcssblk_devices_sem); | |
388 | if (dev_info != NULL) { | |
389 | PRINT_WARN("Segment %s already loaded!\n", local_buf); | |
390 | rc = -EEXIST; | |
391 | goto out; | |
392 | } | |
393 | /* | |
394 | * get a struct dcssblk_dev_info | |
395 | */ | |
88abaab4 | 396 | dev_info = kzalloc(sizeof(struct dcssblk_dev_info), GFP_KERNEL); |
1da177e4 LT |
397 | if (dev_info == NULL) { |
398 | rc = -ENOMEM; | |
399 | goto out; | |
400 | } | |
1da177e4 LT |
401 | |
402 | strcpy(dev_info->segment_name, local_buf); | |
403 | strlcpy(dev_info->dev.bus_id, local_buf, BUS_ID_SIZE); | |
404 | dev_info->dev.release = dcssblk_release_segment; | |
405 | INIT_LIST_HEAD(&dev_info->lh); | |
406 | ||
407 | dev_info->gd = alloc_disk(DCSSBLK_MINORS_PER_DISK); | |
408 | if (dev_info->gd == NULL) { | |
409 | rc = -ENOMEM; | |
410 | goto free_dev_info; | |
411 | } | |
412 | dev_info->gd->major = dcssblk_major; | |
413 | dev_info->gd->fops = &dcssblk_devops; | |
414 | dev_info->dcssblk_queue = blk_alloc_queue(GFP_KERNEL); | |
415 | dev_info->gd->queue = dev_info->dcssblk_queue; | |
416 | dev_info->gd->private_data = dev_info; | |
417 | dev_info->gd->driverfs_dev = &dev_info->dev; | |
418 | /* | |
419 | * load the segment | |
420 | */ | |
421 | rc = segment_load(local_buf, SEGMENT_SHARED, | |
422 | &dev_info->start, &dev_info->end); | |
423 | if (rc < 0) { | |
424 | dcssblk_segment_warn(rc, dev_info->segment_name); | |
425 | goto dealloc_gendisk; | |
426 | } | |
427 | seg_byte_size = (dev_info->end - dev_info->start + 1); | |
428 | set_capacity(dev_info->gd, seg_byte_size >> 9); // size in sectors | |
429 | PRINT_INFO("Loaded segment %s, size = %lu Byte, " | |
430 | "capacity = %lu (512 Byte) sectors\n", local_buf, | |
431 | seg_byte_size, seg_byte_size >> 9); | |
432 | ||
433 | dev_info->segment_type = rc; | |
434 | dev_info->save_pending = 0; | |
435 | dev_info->is_shared = 1; | |
436 | dev_info->dev.parent = dcssblk_root_dev; | |
437 | ||
438 | /* | |
439 | * get minor, add to list | |
440 | */ | |
441 | down_write(&dcssblk_devices_sem); | |
442 | rc = dcssblk_assign_free_minor(dev_info); | |
443 | if (rc) { | |
444 | up_write(&dcssblk_devices_sem); | |
445 | PRINT_ERR("No free minor number available! " | |
446 | "Unloading segment...\n"); | |
447 | goto unload_seg; | |
448 | } | |
449 | sprintf(dev_info->gd->disk_name, "dcssblk%d", | |
450 | dev_info->gd->first_minor); | |
451 | list_add_tail(&dev_info->lh, &dcssblk_devices); | |
452 | ||
453 | if (!try_module_get(THIS_MODULE)) { | |
454 | rc = -ENODEV; | |
455 | goto list_del; | |
456 | } | |
457 | /* | |
458 | * register the device | |
459 | */ | |
460 | rc = device_register(&dev_info->dev); | |
461 | if (rc) { | |
462 | PRINT_ERR("Segment %s could not be registered RC=%d\n", | |
463 | local_buf, rc); | |
464 | module_put(THIS_MODULE); | |
465 | goto list_del; | |
466 | } | |
467 | get_device(&dev_info->dev); | |
468 | rc = device_create_file(&dev_info->dev, &dev_attr_shared); | |
469 | if (rc) | |
470 | goto unregister_dev; | |
471 | rc = device_create_file(&dev_info->dev, &dev_attr_save); | |
472 | if (rc) | |
473 | goto unregister_dev; | |
474 | ||
475 | add_disk(dev_info->gd); | |
476 | ||
477 | blk_queue_make_request(dev_info->dcssblk_queue, dcssblk_make_request); | |
478 | blk_queue_hardsect_size(dev_info->dcssblk_queue, 4096); | |
479 | ||
480 | switch (dev_info->segment_type) { | |
481 | case SEG_TYPE_SR: | |
482 | case SEG_TYPE_ER: | |
483 | case SEG_TYPE_SC: | |
484 | set_disk_ro(dev_info->gd,1); | |
485 | break; | |
486 | default: | |
487 | set_disk_ro(dev_info->gd,0); | |
488 | break; | |
489 | } | |
490 | PRINT_DEBUG("Segment %s loaded successfully\n", local_buf); | |
491 | up_write(&dcssblk_devices_sem); | |
492 | rc = count; | |
493 | goto out; | |
494 | ||
495 | unregister_dev: | |
496 | PRINT_ERR("device_create_file() failed!\n"); | |
497 | list_del(&dev_info->lh); | |
1312f40e | 498 | blk_cleanup_queue(dev_info->dcssblk_queue); |
1da177e4 LT |
499 | dev_info->gd->queue = NULL; |
500 | put_disk(dev_info->gd); | |
501 | device_unregister(&dev_info->dev); | |
502 | segment_unload(dev_info->segment_name); | |
503 | put_device(&dev_info->dev); | |
504 | up_write(&dcssblk_devices_sem); | |
505 | goto out; | |
506 | list_del: | |
507 | list_del(&dev_info->lh); | |
508 | up_write(&dcssblk_devices_sem); | |
509 | unload_seg: | |
510 | segment_unload(local_buf); | |
511 | dealloc_gendisk: | |
1312f40e | 512 | blk_cleanup_queue(dev_info->dcssblk_queue); |
1da177e4 LT |
513 | dev_info->gd->queue = NULL; |
514 | put_disk(dev_info->gd); | |
515 | free_dev_info: | |
516 | kfree(dev_info); | |
517 | out: | |
518 | kfree(local_buf); | |
519 | out_nobuf: | |
520 | return rc; | |
521 | } | |
522 | ||
523 | /* | |
524 | * device attribute for removing devices | |
525 | */ | |
526 | static ssize_t | |
e404e274 | 527 | dcssblk_remove_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
1da177e4 LT |
528 | { |
529 | struct dcssblk_dev_info *dev_info; | |
530 | int rc, i; | |
531 | char *local_buf; | |
532 | ||
533 | if (dev != dcssblk_root_dev) { | |
534 | return -EINVAL; | |
535 | } | |
536 | local_buf = kmalloc(count + 1, GFP_KERNEL); | |
537 | if (local_buf == NULL) { | |
538 | return -ENOMEM; | |
539 | } | |
540 | /* | |
541 | * parse input | |
542 | */ | |
543 | for (i = 0; ((*(buf+i)!='\0') && (*(buf+i)!='\n') && i < count); i++) { | |
544 | local_buf[i] = toupper(buf[i]); | |
545 | } | |
546 | local_buf[i] = '\0'; | |
547 | if ((i == 0) || (i > 8)) { | |
548 | rc = -ENAMETOOLONG; | |
549 | goto out_buf; | |
550 | } | |
551 | ||
552 | down_write(&dcssblk_devices_sem); | |
553 | dev_info = dcssblk_get_device_by_name(local_buf); | |
554 | if (dev_info == NULL) { | |
555 | up_write(&dcssblk_devices_sem); | |
556 | PRINT_WARN("Segment %s is not loaded!\n", local_buf); | |
557 | rc = -ENODEV; | |
558 | goto out_buf; | |
559 | } | |
560 | if (atomic_read(&dev_info->use_count) != 0) { | |
561 | up_write(&dcssblk_devices_sem); | |
562 | PRINT_WARN("Segment %s is in use!\n", local_buf); | |
563 | rc = -EBUSY; | |
564 | goto out_buf; | |
565 | } | |
566 | list_del(&dev_info->lh); | |
567 | ||
568 | del_gendisk(dev_info->gd); | |
1312f40e | 569 | blk_cleanup_queue(dev_info->dcssblk_queue); |
1da177e4 LT |
570 | dev_info->gd->queue = NULL; |
571 | put_disk(dev_info->gd); | |
572 | device_unregister(&dev_info->dev); | |
573 | segment_unload(dev_info->segment_name); | |
574 | PRINT_DEBUG("Segment %s unloaded successfully\n", | |
575 | dev_info->segment_name); | |
576 | put_device(&dev_info->dev); | |
577 | up_write(&dcssblk_devices_sem); | |
578 | ||
579 | rc = count; | |
580 | out_buf: | |
581 | kfree(local_buf); | |
582 | return rc; | |
583 | } | |
584 | ||
585 | static int | |
586 | dcssblk_open(struct inode *inode, struct file *filp) | |
587 | { | |
588 | struct dcssblk_dev_info *dev_info; | |
589 | int rc; | |
590 | ||
591 | dev_info = inode->i_bdev->bd_disk->private_data; | |
592 | if (NULL == dev_info) { | |
593 | rc = -ENODEV; | |
594 | goto out; | |
595 | } | |
596 | atomic_inc(&dev_info->use_count); | |
597 | inode->i_bdev->bd_block_size = 4096; | |
598 | rc = 0; | |
599 | out: | |
600 | return rc; | |
601 | } | |
602 | ||
603 | static int | |
604 | dcssblk_release(struct inode *inode, struct file *filp) | |
605 | { | |
606 | struct dcssblk_dev_info *dev_info; | |
607 | int rc; | |
608 | ||
609 | dev_info = inode->i_bdev->bd_disk->private_data; | |
610 | if (NULL == dev_info) { | |
611 | rc = -ENODEV; | |
612 | goto out; | |
613 | } | |
614 | down_write(&dcssblk_devices_sem); | |
615 | if (atomic_dec_and_test(&dev_info->use_count) | |
616 | && (dev_info->save_pending)) { | |
617 | PRINT_INFO("Segment %s became idle and is being saved now\n", | |
618 | dev_info->segment_name); | |
619 | segment_save(dev_info->segment_name); | |
620 | dev_info->save_pending = 0; | |
621 | } | |
622 | up_write(&dcssblk_devices_sem); | |
623 | rc = 0; | |
624 | out: | |
625 | return rc; | |
626 | } | |
627 | ||
628 | static int | |
165125e1 | 629 | dcssblk_make_request(struct request_queue *q, struct bio *bio) |
1da177e4 LT |
630 | { |
631 | struct dcssblk_dev_info *dev_info; | |
632 | struct bio_vec *bvec; | |
633 | unsigned long index; | |
634 | unsigned long page_addr; | |
635 | unsigned long source_addr; | |
636 | unsigned long bytes_done; | |
637 | int i; | |
638 | ||
639 | bytes_done = 0; | |
640 | dev_info = bio->bi_bdev->bd_disk->private_data; | |
641 | if (dev_info == NULL) | |
642 | goto fail; | |
643 | if ((bio->bi_sector & 7) != 0 || (bio->bi_size & 4095) != 0) | |
644 | /* Request is not page-aligned. */ | |
645 | goto fail; | |
646 | if (((bio->bi_size >> 9) + bio->bi_sector) | |
647 | > get_capacity(bio->bi_bdev->bd_disk)) { | |
648 | /* Request beyond end of DCSS segment. */ | |
649 | goto fail; | |
650 | } | |
420edbcc CO |
651 | /* verify data transfer direction */ |
652 | if (dev_info->is_shared) { | |
653 | switch (dev_info->segment_type) { | |
654 | case SEG_TYPE_SR: | |
655 | case SEG_TYPE_ER: | |
656 | case SEG_TYPE_SC: | |
657 | /* cannot write to these segments */ | |
658 | if (bio_data_dir(bio) == WRITE) { | |
659 | PRINT_WARN("rejecting write to ro segment %s\n", dev_info->dev.bus_id); | |
660 | goto fail; | |
661 | } | |
662 | } | |
663 | } | |
664 | ||
1da177e4 LT |
665 | index = (bio->bi_sector >> 3); |
666 | bio_for_each_segment(bvec, bio, i) { | |
667 | page_addr = (unsigned long) | |
668 | page_address(bvec->bv_page) + bvec->bv_offset; | |
669 | source_addr = dev_info->start + (index<<12) + bytes_done; | |
670 | if (unlikely(page_addr & 4095) != 0 || (bvec->bv_len & 4095) != 0) | |
671 | // More paranoia. | |
672 | goto fail; | |
673 | if (bio_data_dir(bio) == READ) { | |
674 | memcpy((void*)page_addr, (void*)source_addr, | |
675 | bvec->bv_len); | |
676 | } else { | |
677 | memcpy((void*)source_addr, (void*)page_addr, | |
678 | bvec->bv_len); | |
679 | } | |
680 | bytes_done += bvec->bv_len; | |
681 | } | |
6712ecf8 | 682 | bio_endio(bio, 0); |
1da177e4 LT |
683 | return 0; |
684 | fail: | |
6712ecf8 | 685 | bio_io_error(bio); |
420edbcc CO |
686 | return 0; |
687 | } | |
688 | ||
689 | static int | |
690 | dcssblk_direct_access (struct block_device *bdev, sector_t secnum, | |
691 | unsigned long *data) | |
692 | { | |
693 | struct dcssblk_dev_info *dev_info; | |
694 | unsigned long pgoff; | |
695 | ||
696 | dev_info = bdev->bd_disk->private_data; | |
697 | if (!dev_info) | |
698 | return -ENODEV; | |
699 | if (secnum % (PAGE_SIZE/512)) | |
700 | return -EINVAL; | |
701 | pgoff = secnum / (PAGE_SIZE / 512); | |
702 | if ((pgoff+1)*PAGE_SIZE-1 > dev_info->end - dev_info->start) | |
703 | return -ERANGE; | |
704 | *data = (unsigned long) (dev_info->start+pgoff*PAGE_SIZE); | |
1da177e4 LT |
705 | return 0; |
706 | } | |
707 | ||
708 | static void | |
709 | dcssblk_check_params(void) | |
710 | { | |
711 | int rc, i, j, k; | |
712 | char buf[9]; | |
713 | struct dcssblk_dev_info *dev_info; | |
714 | ||
715 | for (i = 0; (i < DCSSBLK_PARM_LEN) && (dcssblk_segments[i] != '\0'); | |
716 | i++) { | |
717 | for (j = i; (dcssblk_segments[j] != ',') && | |
718 | (dcssblk_segments[j] != '\0') && | |
719 | (dcssblk_segments[j] != '(') && | |
720 | (j - i) < 8; j++) | |
721 | { | |
722 | buf[j-i] = dcssblk_segments[j]; | |
723 | } | |
724 | buf[j-i] = '\0'; | |
f901e5d1 | 725 | rc = dcssblk_add_store(dcssblk_root_dev, NULL, buf, j-i); |
1da177e4 LT |
726 | if ((rc >= 0) && (dcssblk_segments[j] == '(')) { |
727 | for (k = 0; buf[k] != '\0'; k++) | |
728 | buf[k] = toupper(buf[k]); | |
729 | if (!strncmp(&dcssblk_segments[j], "(local)", 7)) { | |
730 | down_read(&dcssblk_devices_sem); | |
731 | dev_info = dcssblk_get_device_by_name(buf); | |
732 | up_read(&dcssblk_devices_sem); | |
733 | if (dev_info) | |
734 | dcssblk_shared_store(&dev_info->dev, | |
f901e5d1 | 735 | NULL, "0\n", 2); |
1da177e4 LT |
736 | } |
737 | } | |
738 | while ((dcssblk_segments[j] != ',') && | |
739 | (dcssblk_segments[j] != '\0')) | |
740 | { | |
741 | j++; | |
742 | } | |
743 | if (dcssblk_segments[j] == '\0') | |
744 | break; | |
745 | i = j; | |
746 | } | |
747 | } | |
748 | ||
749 | /* | |
750 | * The init/exit functions. | |
751 | */ | |
752 | static void __exit | |
753 | dcssblk_exit(void) | |
754 | { | |
1da177e4 LT |
755 | PRINT_DEBUG("DCSSBLOCK EXIT...\n"); |
756 | s390_root_dev_unregister(dcssblk_root_dev); | |
00d59405 | 757 | unregister_blkdev(dcssblk_major, DCSSBLK_NAME); |
1da177e4 LT |
758 | PRINT_DEBUG("...finished!\n"); |
759 | } | |
760 | ||
761 | static int __init | |
762 | dcssblk_init(void) | |
763 | { | |
764 | int rc; | |
765 | ||
766 | PRINT_DEBUG("DCSSBLOCK INIT...\n"); | |
767 | dcssblk_root_dev = s390_root_dev_register("dcssblk"); | |
768 | if (IS_ERR(dcssblk_root_dev)) { | |
769 | PRINT_ERR("device_register() failed!\n"); | |
770 | return PTR_ERR(dcssblk_root_dev); | |
771 | } | |
772 | rc = device_create_file(dcssblk_root_dev, &dev_attr_add); | |
773 | if (rc) { | |
774 | PRINT_ERR("device_create_file(add) failed!\n"); | |
775 | s390_root_dev_unregister(dcssblk_root_dev); | |
776 | return rc; | |
777 | } | |
778 | rc = device_create_file(dcssblk_root_dev, &dev_attr_remove); | |
779 | if (rc) { | |
780 | PRINT_ERR("device_create_file(remove) failed!\n"); | |
781 | s390_root_dev_unregister(dcssblk_root_dev); | |
782 | return rc; | |
783 | } | |
784 | rc = register_blkdev(0, DCSSBLK_NAME); | |
785 | if (rc < 0) { | |
786 | PRINT_ERR("Can't get dynamic major!\n"); | |
787 | s390_root_dev_unregister(dcssblk_root_dev); | |
788 | return rc; | |
789 | } | |
790 | dcssblk_major = rc; | |
791 | init_rwsem(&dcssblk_devices_sem); | |
792 | ||
793 | dcssblk_check_params(); | |
794 | ||
795 | PRINT_DEBUG("...finished!\n"); | |
796 | return 0; | |
797 | } | |
798 | ||
799 | module_init(dcssblk_init); | |
800 | module_exit(dcssblk_exit); | |
801 | ||
802 | module_param_string(segments, dcssblk_segments, DCSSBLK_PARM_LEN, 0444); | |
803 | MODULE_PARM_DESC(segments, "Name of DCSS segment(s) to be loaded, " | |
804 | "comma-separated list, each name max. 8 chars.\n" | |
805 | "Adding \"(local)\" to segment name equals echoing 0 to " | |
806 | "/sys/devices/dcssblk/<segment name>/shared after loading " | |
807 | "the segment - \n" | |
808 | "e.g. segments=\"mydcss1,mydcss2,mydcss3(local)\""); | |
809 | ||
810 | MODULE_LICENSE("GPL"); |