dcssblk.c revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
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 35static int dcssblk_open(struct inode *inode, struct file *filp); 36static int dcssblk_release(struct inode *inode, struct file *filp); 37static int dcssblk_make_request(struct request_queue *q, struct bio *bio); 38 39static char dcssblk_segments[DCSSBLK_PARM_LEN] = "\0"; 40 41static int dcssblk_major; 42static struct block_device_operations dcssblk_devops = { 43 .owner = THIS_MODULE, 44 .open = dcssblk_open, 45 .release = dcssblk_release, 46}; 47 48static ssize_t dcssblk_add_store(struct device * dev, const char * buf, 49 size_t count); 50static ssize_t dcssblk_remove_store(struct device * dev, const char * buf, 51 size_t count); 52static ssize_t dcssblk_save_store(struct device * dev, const char * buf, 53 size_t count); 54static ssize_t dcssblk_save_show(struct device *dev, char *buf); 55static ssize_t dcssblk_shared_store(struct device * dev, const char * buf, 56 size_t count); 57static ssize_t dcssblk_shared_show(struct device *dev, char *buf); 58 59static DEVICE_ATTR(add, S_IWUSR, NULL, dcssblk_add_store); 60static DEVICE_ATTR(remove, S_IWUSR, NULL, dcssblk_remove_store); 61static DEVICE_ATTR(save, S_IWUSR | S_IRUGO, dcssblk_save_show, 62 dcssblk_save_store); 63static DEVICE_ATTR(shared, S_IWUSR | S_IRUGO, dcssblk_shared_show, 64 dcssblk_shared_store); 65 66static struct device *dcssblk_root_dev; 67 68struct dcssblk_dev_info { 69 struct list_head lh; 70 struct device dev; 71 char segment_name[BUS_ID_SIZE]; 72 atomic_t use_count; 73 struct gendisk *gd; 74 unsigned long start; 75 unsigned long end; 76 int segment_type; 77 unsigned char save_pending; 78 unsigned char is_shared; 79 struct request_queue *dcssblk_queue; 80}; 81 82static struct list_head dcssblk_devices = LIST_HEAD_INIT(dcssblk_devices); 83static struct rw_semaphore dcssblk_devices_sem; 84 85/* 86 * release function for segment device. 87 */ 88static void 89dcssblk_release_segment(struct device *dev) 90{ 91 PRINT_DEBUG("segment release fn called for %s\n", dev->bus_id); 92 kfree(container_of(dev, struct dcssblk_dev_info, dev)); 93 module_put(THIS_MODULE); 94} 95 96/* 97 * get a minor number. needs to be called with 98 * down_write(&dcssblk_devices_sem) and the 99 * device needs to be enqueued before the semaphore is 100 * freed. 101 */ 102static inline int 103dcssblk_assign_free_minor(struct dcssblk_dev_info *dev_info) 104{ 105 int minor, found; 106 struct dcssblk_dev_info *entry; 107 108 if (dev_info == NULL) 109 return -EINVAL; 110 for (minor = 0; minor < (1<<MINORBITS); minor++) { 111 found = 0; 112 // test if minor available 113 list_for_each_entry(entry, &dcssblk_devices, lh) 114 if (minor == entry->gd->first_minor) 115 found++; 116 if (!found) break; // got unused minor 117 } 118 if (found) 119 return -EBUSY; 120 dev_info->gd->first_minor = minor; 121 return 0; 122} 123 124/* 125 * get the struct dcssblk_dev_info from dcssblk_devices 126 * for the given name. 127 * down_read(&dcssblk_devices_sem) must be held. 128 */ 129static struct dcssblk_dev_info * 130dcssblk_get_device_by_name(char *name) 131{ 132 struct dcssblk_dev_info *entry; 133 134 list_for_each_entry(entry, &dcssblk_devices, lh) { 135 if (!strcmp(name, entry->segment_name)) { 136 return entry; 137 } 138 } 139 return NULL; 140} 141 142/* 143 * print appropriate error message for segment_load()/segment_type() 144 * return code 145 */ 146static void 147dcssblk_segment_warn(int rc, char* seg_name) 148{ 149 switch (rc) { 150 case -ENOENT: 151 PRINT_WARN("cannot load/query segment %s, does not exist\n", 152 seg_name); 153 break; 154 case -ENOSYS: 155 PRINT_WARN("cannot load/query segment %s, not running on VM\n", 156 seg_name); 157 break; 158 case -EIO: 159 PRINT_WARN("cannot load/query segment %s, hardware error\n", 160 seg_name); 161 break; 162 case -ENOTSUPP: 163 PRINT_WARN("cannot load/query segment %s, is a multi-part " 164 "segment\n", seg_name); 165 break; 166 case -ENOSPC: 167 PRINT_WARN("cannot load/query segment %s, overlaps with " 168 "storage\n", seg_name); 169 break; 170 case -EBUSY: 171 PRINT_WARN("cannot load/query segment %s, overlaps with " 172 "already loaded dcss\n", seg_name); 173 break; 174 case -EPERM: 175 PRINT_WARN("cannot load/query segment %s, already loaded in " 176 "incompatible mode\n", seg_name); 177 break; 178 case -ENOMEM: 179 PRINT_WARN("cannot load/query segment %s, out of memory\n", 180 seg_name); 181 break; 182 case -ERANGE: 183 PRINT_WARN("cannot load/query segment %s, exceeds kernel " 184 "mapping range\n", seg_name); 185 break; 186 default: 187 PRINT_WARN("cannot load/query segment %s, return value %i\n", 188 seg_name, rc); 189 break; 190 } 191} 192 193/* 194 * device attribute for switching shared/nonshared (exclusive) 195 * operation (show + store) 196 */ 197static ssize_t 198dcssblk_shared_show(struct device *dev, char *buf) 199{ 200 struct dcssblk_dev_info *dev_info; 201 202 dev_info = container_of(dev, struct dcssblk_dev_info, dev); 203 return sprintf(buf, dev_info->is_shared ? "1\n" : "0\n"); 204} 205 206static ssize_t 207dcssblk_shared_store(struct device *dev, const char *inbuf, size_t count) 208{ 209 struct dcssblk_dev_info *dev_info; 210 int rc; 211 212 if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0')) { 213 PRINT_WARN("Invalid value, must be 0 or 1\n"); 214 return -EINVAL; 215 } 216 down_write(&dcssblk_devices_sem); 217 dev_info = container_of(dev, struct dcssblk_dev_info, dev); 218 if (atomic_read(&dev_info->use_count)) { 219 PRINT_ERR("share: segment %s is busy!\n", 220 dev_info->segment_name); 221 rc = -EBUSY; 222 goto out; 223 } 224 if (inbuf[0] == '1') { 225 // reload segment in shared mode 226 rc = segment_modify_shared(dev_info->segment_name, 227 SEGMENT_SHARED); 228 if (rc < 0) { 229 BUG_ON(rc == -EINVAL); 230 if (rc == -EIO || rc == -ENOENT) 231 goto removeseg; 232 } else { 233 dev_info->is_shared = 1; 234 switch (dev_info->segment_type) { 235 case SEG_TYPE_SR: 236 case SEG_TYPE_ER: 237 case SEG_TYPE_SC: 238 set_disk_ro(dev_info->gd,1); 239 } 240 } 241 } else if (inbuf[0] == '0') { 242 // reload segment in exclusive mode 243 if (dev_info->segment_type == SEG_TYPE_SC) { 244 PRINT_ERR("Segment type SC (%s) cannot be loaded in " 245 "non-shared mode\n", dev_info->segment_name); 246 rc = -EINVAL; 247 goto out; 248 } 249 rc = segment_modify_shared(dev_info->segment_name, 250 SEGMENT_EXCLUSIVE); 251 if (rc < 0) { 252 BUG_ON(rc == -EINVAL); 253 if (rc == -EIO || rc == -ENOENT) 254 goto removeseg; 255 } else { 256 dev_info->is_shared = 0; 257 set_disk_ro(dev_info->gd, 0); 258 } 259 } else { 260 PRINT_WARN("Invalid value, must be 0 or 1\n"); 261 rc = -EINVAL; 262 goto out; 263 } 264 rc = count; 265 goto out; 266 267removeseg: 268 PRINT_ERR("Could not reload segment %s, removing it now!\n", 269 dev_info->segment_name); 270 list_del(&dev_info->lh); 271 272 del_gendisk(dev_info->gd); 273 blk_put_queue(dev_info->dcssblk_queue); 274 dev_info->gd->queue = NULL; 275 put_disk(dev_info->gd); 276 device_unregister(dev); 277 put_device(dev); 278out: 279 up_write(&dcssblk_devices_sem); 280 return rc; 281} 282 283/* 284 * device attribute for save operation on current copy 285 * of the segment. If the segment is busy, saving will 286 * become pending until it gets released, which can be 287 * undone by storing a non-true value to this entry. 288 * (show + store) 289 */ 290static ssize_t 291dcssblk_save_show(struct device *dev, char *buf) 292{ 293 struct dcssblk_dev_info *dev_info; 294 295 dev_info = container_of(dev, struct dcssblk_dev_info, dev); 296 return sprintf(buf, dev_info->save_pending ? "1\n" : "0\n"); 297} 298 299static ssize_t 300dcssblk_save_store(struct device *dev, const char *inbuf, size_t count) 301{ 302 struct dcssblk_dev_info *dev_info; 303 304 if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0')) { 305 PRINT_WARN("Invalid value, must be 0 or 1\n"); 306 return -EINVAL; 307 } 308 dev_info = container_of(dev, struct dcssblk_dev_info, dev); 309 310 down_write(&dcssblk_devices_sem); 311 if (inbuf[0] == '1') { 312 if (atomic_read(&dev_info->use_count) == 0) { 313 // device is idle => we save immediately 314 PRINT_INFO("Saving segment %s\n", 315 dev_info->segment_name); 316 segment_save(dev_info->segment_name); 317 } else { 318 // device is busy => we save it when it becomes 319 // idle in dcssblk_release 320 PRINT_INFO("Segment %s is currently busy, it will " 321 "be saved when it becomes idle...\n", 322 dev_info->segment_name); 323 dev_info->save_pending = 1; 324 } 325 } else if (inbuf[0] == '0') { 326 if (dev_info->save_pending) { 327 // device is busy & the user wants to undo his save 328 // request 329 dev_info->save_pending = 0; 330 PRINT_INFO("Pending save for segment %s deactivated\n", 331 dev_info->segment_name); 332 } 333 } else { 334 up_write(&dcssblk_devices_sem); 335 PRINT_WARN("Invalid value, must be 0 or 1\n"); 336 return -EINVAL; 337 } 338 up_write(&dcssblk_devices_sem); 339 return count; 340} 341 342/* 343 * device attribute for adding devices 344 */ 345static ssize_t 346dcssblk_add_store(struct device *dev, const char *buf, size_t count) 347{ 348 int rc, i; 349 struct dcssblk_dev_info *dev_info; 350 char *local_buf; 351 unsigned long seg_byte_size; 352 353 dev_info = NULL; 354 if (dev != dcssblk_root_dev) { 355 rc = -EINVAL; 356 goto out_nobuf; 357 } 358 local_buf = kmalloc(count + 1, GFP_KERNEL); 359 if (local_buf == NULL) { 360 rc = -ENOMEM; 361 goto out_nobuf; 362 } 363 /* 364 * parse input 365 */ 366 for (i = 0; ((buf[i] != '\0') && (buf[i] != '\n') && i < count); i++) { 367 local_buf[i] = toupper(buf[i]); 368 } 369 local_buf[i] = '\0'; 370 if ((i == 0) || (i > 8)) { 371 rc = -ENAMETOOLONG; 372 goto out; 373 } 374 /* 375 * already loaded? 376 */ 377 down_read(&dcssblk_devices_sem); 378 dev_info = dcssblk_get_device_by_name(local_buf); 379 up_read(&dcssblk_devices_sem); 380 if (dev_info != NULL) { 381 PRINT_WARN("Segment %s already loaded!\n", local_buf); 382 rc = -EEXIST; 383 goto out; 384 } 385 /* 386 * get a struct dcssblk_dev_info 387 */ 388 dev_info = kmalloc(sizeof(struct dcssblk_dev_info), GFP_KERNEL); 389 if (dev_info == NULL) { 390 rc = -ENOMEM; 391 goto out; 392 } 393 memset(dev_info, 0, sizeof(struct dcssblk_dev_info)); 394 395 strcpy(dev_info->segment_name, local_buf); 396 strlcpy(dev_info->dev.bus_id, local_buf, BUS_ID_SIZE); 397 dev_info->dev.release = dcssblk_release_segment; 398 INIT_LIST_HEAD(&dev_info->lh); 399 400 dev_info->gd = alloc_disk(DCSSBLK_MINORS_PER_DISK); 401 if (dev_info->gd == NULL) { 402 rc = -ENOMEM; 403 goto free_dev_info; 404 } 405 dev_info->gd->major = dcssblk_major; 406 dev_info->gd->fops = &dcssblk_devops; 407 dev_info->dcssblk_queue = blk_alloc_queue(GFP_KERNEL); 408 dev_info->gd->queue = dev_info->dcssblk_queue; 409 dev_info->gd->private_data = dev_info; 410 dev_info->gd->driverfs_dev = &dev_info->dev; 411 /* 412 * load the segment 413 */ 414 rc = segment_load(local_buf, SEGMENT_SHARED, 415 &dev_info->start, &dev_info->end); 416 if (rc < 0) { 417 dcssblk_segment_warn(rc, dev_info->segment_name); 418 goto dealloc_gendisk; 419 } 420 seg_byte_size = (dev_info->end - dev_info->start + 1); 421 set_capacity(dev_info->gd, seg_byte_size >> 9); // size in sectors 422 PRINT_INFO("Loaded segment %s, size = %lu Byte, " 423 "capacity = %lu (512 Byte) sectors\n", local_buf, 424 seg_byte_size, seg_byte_size >> 9); 425 426 dev_info->segment_type = rc; 427 dev_info->save_pending = 0; 428 dev_info->is_shared = 1; 429 dev_info->dev.parent = dcssblk_root_dev; 430 431 /* 432 * get minor, add to list 433 */ 434 down_write(&dcssblk_devices_sem); 435 rc = dcssblk_assign_free_minor(dev_info); 436 if (rc) { 437 up_write(&dcssblk_devices_sem); 438 PRINT_ERR("No free minor number available! " 439 "Unloading segment...\n"); 440 goto unload_seg; 441 } 442 sprintf(dev_info->gd->disk_name, "dcssblk%d", 443 dev_info->gd->first_minor); 444 list_add_tail(&dev_info->lh, &dcssblk_devices); 445 446 if (!try_module_get(THIS_MODULE)) { 447 rc = -ENODEV; 448 goto list_del; 449 } 450 /* 451 * register the device 452 */ 453 rc = device_register(&dev_info->dev); 454 if (rc) { 455 PRINT_ERR("Segment %s could not be registered RC=%d\n", 456 local_buf, rc); 457 module_put(THIS_MODULE); 458 goto list_del; 459 } 460 get_device(&dev_info->dev); 461 rc = device_create_file(&dev_info->dev, &dev_attr_shared); 462 if (rc) 463 goto unregister_dev; 464 rc = device_create_file(&dev_info->dev, &dev_attr_save); 465 if (rc) 466 goto unregister_dev; 467 468 add_disk(dev_info->gd); 469 470 blk_queue_make_request(dev_info->dcssblk_queue, dcssblk_make_request); 471 blk_queue_hardsect_size(dev_info->dcssblk_queue, 4096); 472 473 switch (dev_info->segment_type) { 474 case SEG_TYPE_SR: 475 case SEG_TYPE_ER: 476 case SEG_TYPE_SC: 477 set_disk_ro(dev_info->gd,1); 478 break; 479 default: 480 set_disk_ro(dev_info->gd,0); 481 break; 482 } 483 PRINT_DEBUG("Segment %s loaded successfully\n", local_buf); 484 up_write(&dcssblk_devices_sem); 485 rc = count; 486 goto out; 487 488unregister_dev: 489 PRINT_ERR("device_create_file() failed!\n"); 490 list_del(&dev_info->lh); 491 blk_put_queue(dev_info->dcssblk_queue); 492 dev_info->gd->queue = NULL; 493 put_disk(dev_info->gd); 494 device_unregister(&dev_info->dev); 495 segment_unload(dev_info->segment_name); 496 put_device(&dev_info->dev); 497 up_write(&dcssblk_devices_sem); 498 goto out; 499list_del: 500 list_del(&dev_info->lh); 501 up_write(&dcssblk_devices_sem); 502unload_seg: 503 segment_unload(local_buf); 504dealloc_gendisk: 505 blk_put_queue(dev_info->dcssblk_queue); 506 dev_info->gd->queue = NULL; 507 put_disk(dev_info->gd); 508free_dev_info: 509 kfree(dev_info); 510out: 511 kfree(local_buf); 512out_nobuf: 513 return rc; 514} 515 516/* 517 * device attribute for removing devices 518 */ 519static ssize_t 520dcssblk_remove_store(struct device *dev, const char *buf, size_t count) 521{ 522 struct dcssblk_dev_info *dev_info; 523 int rc, i; 524 char *local_buf; 525 526 if (dev != dcssblk_root_dev) { 527 return -EINVAL; 528 } 529 local_buf = kmalloc(count + 1, GFP_KERNEL); 530 if (local_buf == NULL) { 531 return -ENOMEM; 532 } 533 /* 534 * parse input 535 */ 536 for (i = 0; ((*(buf+i)!='\0') && (*(buf+i)!='\n') && i < count); i++) { 537 local_buf[i] = toupper(buf[i]); 538 } 539 local_buf[i] = '\0'; 540 if ((i == 0) || (i > 8)) { 541 rc = -ENAMETOOLONG; 542 goto out_buf; 543 } 544 545 down_write(&dcssblk_devices_sem); 546 dev_info = dcssblk_get_device_by_name(local_buf); 547 if (dev_info == NULL) { 548 up_write(&dcssblk_devices_sem); 549 PRINT_WARN("Segment %s is not loaded!\n", local_buf); 550 rc = -ENODEV; 551 goto out_buf; 552 } 553 if (atomic_read(&dev_info->use_count) != 0) { 554 up_write(&dcssblk_devices_sem); 555 PRINT_WARN("Segment %s is in use!\n", local_buf); 556 rc = -EBUSY; 557 goto out_buf; 558 } 559 list_del(&dev_info->lh); 560 561 del_gendisk(dev_info->gd); 562 blk_put_queue(dev_info->dcssblk_queue); 563 dev_info->gd->queue = NULL; 564 put_disk(dev_info->gd); 565 device_unregister(&dev_info->dev); 566 segment_unload(dev_info->segment_name); 567 PRINT_DEBUG("Segment %s unloaded successfully\n", 568 dev_info->segment_name); 569 put_device(&dev_info->dev); 570 up_write(&dcssblk_devices_sem); 571 572 rc = count; 573out_buf: 574 kfree(local_buf); 575 return rc; 576} 577 578static int 579dcssblk_open(struct inode *inode, struct file *filp) 580{ 581 struct dcssblk_dev_info *dev_info; 582 int rc; 583 584 dev_info = inode->i_bdev->bd_disk->private_data; 585 if (NULL == dev_info) { 586 rc = -ENODEV; 587 goto out; 588 } 589 atomic_inc(&dev_info->use_count); 590 inode->i_bdev->bd_block_size = 4096; 591 rc = 0; 592out: 593 return rc; 594} 595 596static int 597dcssblk_release(struct inode *inode, struct file *filp) 598{ 599 struct dcssblk_dev_info *dev_info; 600 int rc; 601 602 dev_info = inode->i_bdev->bd_disk->private_data; 603 if (NULL == dev_info) { 604 rc = -ENODEV; 605 goto out; 606 } 607 down_write(&dcssblk_devices_sem); 608 if (atomic_dec_and_test(&dev_info->use_count) 609 && (dev_info->save_pending)) { 610 PRINT_INFO("Segment %s became idle and is being saved now\n", 611 dev_info->segment_name); 612 segment_save(dev_info->segment_name); 613 dev_info->save_pending = 0; 614 } 615 up_write(&dcssblk_devices_sem); 616 rc = 0; 617out: 618 return rc; 619} 620 621static int 622dcssblk_make_request(request_queue_t *q, struct bio *bio) 623{ 624 struct dcssblk_dev_info *dev_info; 625 struct bio_vec *bvec; 626 unsigned long index; 627 unsigned long page_addr; 628 unsigned long source_addr; 629 unsigned long bytes_done; 630 int i; 631 632 bytes_done = 0; 633 dev_info = bio->bi_bdev->bd_disk->private_data; 634 if (dev_info == NULL) 635 goto fail; 636 if ((bio->bi_sector & 7) != 0 || (bio->bi_size & 4095) != 0) 637 /* Request is not page-aligned. */ 638 goto fail; 639 if (((bio->bi_size >> 9) + bio->bi_sector) 640 > get_capacity(bio->bi_bdev->bd_disk)) { 641 /* Request beyond end of DCSS segment. */ 642 goto fail; 643 } 644 index = (bio->bi_sector >> 3); 645 bio_for_each_segment(bvec, bio, i) { 646 page_addr = (unsigned long) 647 page_address(bvec->bv_page) + bvec->bv_offset; 648 source_addr = dev_info->start + (index<<12) + bytes_done; 649 if (unlikely(page_addr & 4095) != 0 || (bvec->bv_len & 4095) != 0) 650 // More paranoia. 651 goto fail; 652 if (bio_data_dir(bio) == READ) { 653 memcpy((void*)page_addr, (void*)source_addr, 654 bvec->bv_len); 655 } else { 656 memcpy((void*)source_addr, (void*)page_addr, 657 bvec->bv_len); 658 } 659 bytes_done += bvec->bv_len; 660 } 661 bio_endio(bio, bytes_done, 0); 662 return 0; 663fail: 664 bio_io_error(bio, bytes_done); 665 return 0; 666} 667 668static void 669dcssblk_check_params(void) 670{ 671 int rc, i, j, k; 672 char buf[9]; 673 struct dcssblk_dev_info *dev_info; 674 675 for (i = 0; (i < DCSSBLK_PARM_LEN) && (dcssblk_segments[i] != '\0'); 676 i++) { 677 for (j = i; (dcssblk_segments[j] != ',') && 678 (dcssblk_segments[j] != '\0') && 679 (dcssblk_segments[j] != '(') && 680 (j - i) < 8; j++) 681 { 682 buf[j-i] = dcssblk_segments[j]; 683 } 684 buf[j-i] = '\0'; 685 rc = dcssblk_add_store(dcssblk_root_dev, buf, j-i); 686 if ((rc >= 0) && (dcssblk_segments[j] == '(')) { 687 for (k = 0; buf[k] != '\0'; k++) 688 buf[k] = toupper(buf[k]); 689 if (!strncmp(&dcssblk_segments[j], "(local)", 7)) { 690 down_read(&dcssblk_devices_sem); 691 dev_info = dcssblk_get_device_by_name(buf); 692 up_read(&dcssblk_devices_sem); 693 if (dev_info) 694 dcssblk_shared_store(&dev_info->dev, 695 "0\n", 2); 696 } 697 } 698 while ((dcssblk_segments[j] != ',') && 699 (dcssblk_segments[j] != '\0')) 700 { 701 j++; 702 } 703 if (dcssblk_segments[j] == '\0') 704 break; 705 i = j; 706 } 707} 708 709/* 710 * The init/exit functions. 711 */ 712static void __exit 713dcssblk_exit(void) 714{ 715 int rc; 716 717 PRINT_DEBUG("DCSSBLOCK EXIT...\n"); 718 s390_root_dev_unregister(dcssblk_root_dev); 719 rc = unregister_blkdev(dcssblk_major, DCSSBLK_NAME); 720 if (rc) { 721 PRINT_ERR("unregister_blkdev() failed!\n"); 722 } 723 PRINT_DEBUG("...finished!\n"); 724} 725 726static int __init 727dcssblk_init(void) 728{ 729 int rc; 730 731 PRINT_DEBUG("DCSSBLOCK INIT...\n"); 732 dcssblk_root_dev = s390_root_dev_register("dcssblk"); 733 if (IS_ERR(dcssblk_root_dev)) { 734 PRINT_ERR("device_register() failed!\n"); 735 return PTR_ERR(dcssblk_root_dev); 736 } 737 rc = device_create_file(dcssblk_root_dev, &dev_attr_add); 738 if (rc) { 739 PRINT_ERR("device_create_file(add) failed!\n"); 740 s390_root_dev_unregister(dcssblk_root_dev); 741 return rc; 742 } 743 rc = device_create_file(dcssblk_root_dev, &dev_attr_remove); 744 if (rc) { 745 PRINT_ERR("device_create_file(remove) failed!\n"); 746 s390_root_dev_unregister(dcssblk_root_dev); 747 return rc; 748 } 749 rc = register_blkdev(0, DCSSBLK_NAME); 750 if (rc < 0) { 751 PRINT_ERR("Can't get dynamic major!\n"); 752 s390_root_dev_unregister(dcssblk_root_dev); 753 return rc; 754 } 755 dcssblk_major = rc; 756 init_rwsem(&dcssblk_devices_sem); 757 758 dcssblk_check_params(); 759 760 PRINT_DEBUG("...finished!\n"); 761 return 0; 762} 763 764module_init(dcssblk_init); 765module_exit(dcssblk_exit); 766 767module_param_string(segments, dcssblk_segments, DCSSBLK_PARM_LEN, 0444); 768MODULE_PARM_DESC(segments, "Name of DCSS segment(s) to be loaded, " 769 "comma-separated list, each name max. 8 chars.\n" 770 "Adding \"(local)\" to segment name equals echoing 0 to " 771 "/sys/devices/dcssblk/<segment name>/shared after loading " 772 "the segment - \n" 773 "e.g. segments=\"mydcss1,mydcss2,mydcss3(local)\""); 774 775MODULE_LICENSE("GPL"); 776