1 /* 2 * Copyright (C) 2013 Shaohua Li <shli@kernel.org> 3 * Copyright (C) 2014 Red Hat, Inc. 4 * Copyright (C) 2015 Arrikto, Inc. 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms and conditions of the GNU General Public License, 8 * version 2, as published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 13 * more details. 14 * 15 * You should have received a copy of the GNU General Public License along with 16 * this program; if not, write to the Free Software Foundation, Inc., 17 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. 18 */ 19 20 #include <linux/spinlock.h> 21 #include <linux/module.h> 22 #include <linux/idr.h> 23 #include <linux/kernel.h> 24 #include <linux/timer.h> 25 #include <linux/parser.h> 26 #include <linux/vmalloc.h> 27 #include <linux/uio_driver.h> 28 #include <linux/stringify.h> 29 #include <linux/bitops.h> 30 #include <linux/highmem.h> 31 #include <linux/configfs.h> 32 #include <net/genetlink.h> 33 #include <scsi/scsi_common.h> 34 #include <scsi/scsi_proto.h> 35 #include <target/target_core_base.h> 36 #include <target/target_core_fabric.h> 37 #include <target/target_core_backend.h> 38 39 #include <linux/target_core_user.h> 40 41 /* 42 * Define a shared-memory interface for LIO to pass SCSI commands and 43 * data to userspace for processing. This is to allow backends that 44 * are too complex for in-kernel support to be possible. 45 * 46 * It uses the UIO framework to do a lot of the device-creation and 47 * introspection work for us. 48 * 49 * See the .h file for how the ring is laid out. Note that while the 50 * command ring is defined, the particulars of the data area are 51 * not. Offset values in the command entry point to other locations 52 * internal to the mmap()ed area. There is separate space outside the 53 * command ring for data buffers. This leaves maximum flexibility for 54 * moving buffer allocations, or even page flipping or other 55 * allocation techniques, without altering the command ring layout. 56 * 57 * SECURITY: 58 * The user process must be assumed to be malicious. There's no way to 59 * prevent it breaking the command ring protocol if it wants, but in 60 * order to prevent other issues we must only ever read *data* from 61 * the shared memory area, not offsets or sizes. This applies to 62 * command ring entries as well as the mailbox. Extra code needed for 63 * this may have a 'UAM' comment. 64 */ 65 66 67 #define TCMU_TIME_OUT (30 * MSEC_PER_SEC) 68 69 #define DATA_BLOCK_BITS 256 70 #define DATA_BLOCK_SIZE 4096 71 72 #define CMDR_SIZE (16 * 4096) 73 #define DATA_SIZE (DATA_BLOCK_BITS * DATA_BLOCK_SIZE) 74 75 #define TCMU_RING_SIZE (CMDR_SIZE + DATA_SIZE) 76 77 static struct device *tcmu_root_device; 78 79 struct tcmu_hba { 80 u32 host_id; 81 }; 82 83 #define TCMU_CONFIG_LEN 256 84 85 struct tcmu_dev { 86 struct se_device se_dev; 87 88 char *name; 89 struct se_hba *hba; 90 91 #define TCMU_DEV_BIT_OPEN 0 92 #define TCMU_DEV_BIT_BROKEN 1 93 unsigned long flags; 94 95 struct uio_info uio_info; 96 97 struct tcmu_mailbox *mb_addr; 98 size_t dev_size; 99 u32 cmdr_size; 100 u32 cmdr_last_cleaned; 101 /* Offset of data area from start of mb */ 102 /* Must add data_off and mb_addr to get the address */ 103 size_t data_off; 104 size_t data_size; 105 106 DECLARE_BITMAP(data_bitmap, DATA_BLOCK_BITS); 107 108 wait_queue_head_t wait_cmdr; 109 /* TODO should this be a mutex? */ 110 spinlock_t cmdr_lock; 111 112 struct idr commands; 113 spinlock_t commands_lock; 114 115 struct timer_list timeout; 116 unsigned int cmd_time_out; 117 118 char dev_config[TCMU_CONFIG_LEN]; 119 }; 120 121 #define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev) 122 123 #define CMDR_OFF sizeof(struct tcmu_mailbox) 124 125 struct tcmu_cmd { 126 struct se_cmd *se_cmd; 127 struct tcmu_dev *tcmu_dev; 128 129 uint16_t cmd_id; 130 131 /* Can't use se_cmd when cleaning up expired cmds, because if 132 cmd has been completed then accessing se_cmd is off limits */ 133 DECLARE_BITMAP(data_bitmap, DATA_BLOCK_BITS); 134 135 unsigned long deadline; 136 137 #define TCMU_CMD_BIT_EXPIRED 0 138 unsigned long flags; 139 }; 140 141 static struct kmem_cache *tcmu_cmd_cache; 142 143 /* multicast group */ 144 enum tcmu_multicast_groups { 145 TCMU_MCGRP_CONFIG, 146 }; 147 148 static const struct genl_multicast_group tcmu_mcgrps[] = { 149 [TCMU_MCGRP_CONFIG] = { .name = "config", }, 150 }; 151 152 /* Our generic netlink family */ 153 static struct genl_family tcmu_genl_family __ro_after_init = { 154 .module = THIS_MODULE, 155 .hdrsize = 0, 156 .name = "TCM-USER", 157 .version = 1, 158 .maxattr = TCMU_ATTR_MAX, 159 .mcgrps = tcmu_mcgrps, 160 .n_mcgrps = ARRAY_SIZE(tcmu_mcgrps), 161 .netnsok = true, 162 }; 163 164 static struct tcmu_cmd *tcmu_alloc_cmd(struct se_cmd *se_cmd) 165 { 166 struct se_device *se_dev = se_cmd->se_dev; 167 struct tcmu_dev *udev = TCMU_DEV(se_dev); 168 struct tcmu_cmd *tcmu_cmd; 169 int cmd_id; 170 171 tcmu_cmd = kmem_cache_zalloc(tcmu_cmd_cache, GFP_KERNEL); 172 if (!tcmu_cmd) 173 return NULL; 174 175 tcmu_cmd->se_cmd = se_cmd; 176 tcmu_cmd->tcmu_dev = udev; 177 if (udev->cmd_time_out) 178 tcmu_cmd->deadline = jiffies + 179 msecs_to_jiffies(udev->cmd_time_out); 180 181 idr_preload(GFP_KERNEL); 182 spin_lock_irq(&udev->commands_lock); 183 cmd_id = idr_alloc(&udev->commands, tcmu_cmd, 0, 184 USHRT_MAX, GFP_NOWAIT); 185 spin_unlock_irq(&udev->commands_lock); 186 idr_preload_end(); 187 188 if (cmd_id < 0) { 189 kmem_cache_free(tcmu_cmd_cache, tcmu_cmd); 190 return NULL; 191 } 192 tcmu_cmd->cmd_id = cmd_id; 193 194 return tcmu_cmd; 195 } 196 197 static inline void tcmu_flush_dcache_range(void *vaddr, size_t size) 198 { 199 unsigned long offset = offset_in_page(vaddr); 200 201 size = round_up(size+offset, PAGE_SIZE); 202 vaddr -= offset; 203 204 while (size) { 205 flush_dcache_page(virt_to_page(vaddr)); 206 size -= PAGE_SIZE; 207 } 208 } 209 210 /* 211 * Some ring helper functions. We don't assume size is a power of 2 so 212 * we can't use circ_buf.h. 213 */ 214 static inline size_t spc_used(size_t head, size_t tail, size_t size) 215 { 216 int diff = head - tail; 217 218 if (diff >= 0) 219 return diff; 220 else 221 return size + diff; 222 } 223 224 static inline size_t spc_free(size_t head, size_t tail, size_t size) 225 { 226 /* Keep 1 byte unused or we can't tell full from empty */ 227 return (size - spc_used(head, tail, size) - 1); 228 } 229 230 static inline size_t head_to_end(size_t head, size_t size) 231 { 232 return size - head; 233 } 234 235 static inline void new_iov(struct iovec **iov, int *iov_cnt, 236 struct tcmu_dev *udev) 237 { 238 struct iovec *iovec; 239 240 if (*iov_cnt != 0) 241 (*iov)++; 242 (*iov_cnt)++; 243 244 iovec = *iov; 245 memset(iovec, 0, sizeof(struct iovec)); 246 } 247 248 #define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size) 249 250 /* offset is relative to mb_addr */ 251 static inline size_t get_block_offset(struct tcmu_dev *dev, 252 int block, int remaining) 253 { 254 return dev->data_off + block * DATA_BLOCK_SIZE + 255 DATA_BLOCK_SIZE - remaining; 256 } 257 258 static inline size_t iov_tail(struct tcmu_dev *udev, struct iovec *iov) 259 { 260 return (size_t)iov->iov_base + iov->iov_len; 261 } 262 263 static void alloc_and_scatter_data_area(struct tcmu_dev *udev, 264 struct scatterlist *data_sg, unsigned int data_nents, 265 struct iovec **iov, int *iov_cnt, bool copy_data) 266 { 267 int i, block; 268 int block_remaining = 0; 269 void *from, *to; 270 size_t copy_bytes, to_offset; 271 struct scatterlist *sg; 272 273 for_each_sg(data_sg, sg, data_nents, i) { 274 int sg_remaining = sg->length; 275 from = kmap_atomic(sg_page(sg)) + sg->offset; 276 while (sg_remaining > 0) { 277 if (block_remaining == 0) { 278 block = find_first_zero_bit(udev->data_bitmap, 279 DATA_BLOCK_BITS); 280 block_remaining = DATA_BLOCK_SIZE; 281 set_bit(block, udev->data_bitmap); 282 } 283 copy_bytes = min_t(size_t, sg_remaining, 284 block_remaining); 285 to_offset = get_block_offset(udev, block, 286 block_remaining); 287 to = (void *)udev->mb_addr + to_offset; 288 if (*iov_cnt != 0 && 289 to_offset == iov_tail(udev, *iov)) { 290 (*iov)->iov_len += copy_bytes; 291 } else { 292 new_iov(iov, iov_cnt, udev); 293 (*iov)->iov_base = (void __user *) to_offset; 294 (*iov)->iov_len = copy_bytes; 295 } 296 if (copy_data) { 297 memcpy(to, from + sg->length - sg_remaining, 298 copy_bytes); 299 tcmu_flush_dcache_range(to, copy_bytes); 300 } 301 sg_remaining -= copy_bytes; 302 block_remaining -= copy_bytes; 303 } 304 kunmap_atomic(from - sg->offset); 305 } 306 } 307 308 static void free_data_area(struct tcmu_dev *udev, struct tcmu_cmd *cmd) 309 { 310 bitmap_xor(udev->data_bitmap, udev->data_bitmap, cmd->data_bitmap, 311 DATA_BLOCK_BITS); 312 } 313 314 static void gather_data_area(struct tcmu_dev *udev, unsigned long *cmd_bitmap, 315 struct scatterlist *data_sg, unsigned int data_nents) 316 { 317 int i, block; 318 int block_remaining = 0; 319 void *from, *to; 320 size_t copy_bytes, from_offset; 321 struct scatterlist *sg; 322 323 for_each_sg(data_sg, sg, data_nents, i) { 324 int sg_remaining = sg->length; 325 to = kmap_atomic(sg_page(sg)) + sg->offset; 326 while (sg_remaining > 0) { 327 if (block_remaining == 0) { 328 block = find_first_bit(cmd_bitmap, 329 DATA_BLOCK_BITS); 330 block_remaining = DATA_BLOCK_SIZE; 331 clear_bit(block, cmd_bitmap); 332 } 333 copy_bytes = min_t(size_t, sg_remaining, 334 block_remaining); 335 from_offset = get_block_offset(udev, block, 336 block_remaining); 337 from = (void *) udev->mb_addr + from_offset; 338 tcmu_flush_dcache_range(from, copy_bytes); 339 memcpy(to + sg->length - sg_remaining, from, 340 copy_bytes); 341 342 sg_remaining -= copy_bytes; 343 block_remaining -= copy_bytes; 344 } 345 kunmap_atomic(to - sg->offset); 346 } 347 } 348 349 static inline size_t spc_bitmap_free(unsigned long *bitmap) 350 { 351 return DATA_BLOCK_SIZE * (DATA_BLOCK_BITS - 352 bitmap_weight(bitmap, DATA_BLOCK_BITS)); 353 } 354 355 /* 356 * We can't queue a command until we have space available on the cmd ring *and* 357 * space available on the data area. 358 * 359 * Called with ring lock held. 360 */ 361 static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size, size_t data_needed) 362 { 363 struct tcmu_mailbox *mb = udev->mb_addr; 364 size_t space, cmd_needed; 365 u32 cmd_head; 366 367 tcmu_flush_dcache_range(mb, sizeof(*mb)); 368 369 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */ 370 371 /* 372 * If cmd end-of-ring space is too small then we need space for a NOP plus 373 * original cmd - cmds are internally contiguous. 374 */ 375 if (head_to_end(cmd_head, udev->cmdr_size) >= cmd_size) 376 cmd_needed = cmd_size; 377 else 378 cmd_needed = cmd_size + head_to_end(cmd_head, udev->cmdr_size); 379 380 space = spc_free(cmd_head, udev->cmdr_last_cleaned, udev->cmdr_size); 381 if (space < cmd_needed) { 382 pr_debug("no cmd space: %u %u %u\n", cmd_head, 383 udev->cmdr_last_cleaned, udev->cmdr_size); 384 return false; 385 } 386 387 space = spc_bitmap_free(udev->data_bitmap); 388 if (space < data_needed) { 389 pr_debug("no data space: only %zu available, but ask for %zu\n", 390 space, data_needed); 391 return false; 392 } 393 394 return true; 395 } 396 397 static sense_reason_t 398 tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd) 399 { 400 struct tcmu_dev *udev = tcmu_cmd->tcmu_dev; 401 struct se_cmd *se_cmd = tcmu_cmd->se_cmd; 402 size_t base_command_size, command_size; 403 struct tcmu_mailbox *mb; 404 struct tcmu_cmd_entry *entry; 405 struct iovec *iov; 406 int iov_cnt; 407 uint32_t cmd_head; 408 uint64_t cdb_off; 409 bool copy_to_data_area; 410 size_t data_length; 411 DECLARE_BITMAP(old_bitmap, DATA_BLOCK_BITS); 412 413 if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) 414 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 415 416 /* 417 * Must be a certain minimum size for response sense info, but 418 * also may be larger if the iov array is large. 419 * 420 * We prepare way too many iovs for potential uses here, because it's 421 * expensive to tell how many regions are freed in the bitmap 422 */ 423 base_command_size = max(offsetof(struct tcmu_cmd_entry, 424 req.iov[se_cmd->t_bidi_data_nents + 425 se_cmd->t_data_nents]), 426 sizeof(struct tcmu_cmd_entry)); 427 command_size = base_command_size 428 + round_up(scsi_command_size(se_cmd->t_task_cdb), TCMU_OP_ALIGN_SIZE); 429 430 WARN_ON(command_size & (TCMU_OP_ALIGN_SIZE-1)); 431 432 spin_lock_irq(&udev->cmdr_lock); 433 434 mb = udev->mb_addr; 435 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */ 436 data_length = se_cmd->data_length; 437 if (se_cmd->se_cmd_flags & SCF_BIDI) { 438 BUG_ON(!(se_cmd->t_bidi_data_sg && se_cmd->t_bidi_data_nents)); 439 data_length += se_cmd->t_bidi_data_sg->length; 440 } 441 if ((command_size > (udev->cmdr_size / 2)) || 442 data_length > udev->data_size) { 443 pr_warn("TCMU: Request of size %zu/%zu is too big for %u/%zu " 444 "cmd ring/data area\n", command_size, data_length, 445 udev->cmdr_size, udev->data_size); 446 spin_unlock_irq(&udev->cmdr_lock); 447 return TCM_INVALID_CDB_FIELD; 448 } 449 450 while (!is_ring_space_avail(udev, command_size, data_length)) { 451 int ret; 452 DEFINE_WAIT(__wait); 453 454 prepare_to_wait(&udev->wait_cmdr, &__wait, TASK_INTERRUPTIBLE); 455 456 pr_debug("sleeping for ring space\n"); 457 spin_unlock_irq(&udev->cmdr_lock); 458 if (udev->cmd_time_out) 459 ret = schedule_timeout( 460 msecs_to_jiffies(udev->cmd_time_out)); 461 else 462 ret = schedule_timeout(msecs_to_jiffies(TCMU_TIME_OUT)); 463 finish_wait(&udev->wait_cmdr, &__wait); 464 if (!ret) { 465 pr_warn("tcmu: command timed out\n"); 466 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 467 } 468 469 spin_lock_irq(&udev->cmdr_lock); 470 471 /* We dropped cmdr_lock, cmd_head is stale */ 472 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */ 473 } 474 475 /* Insert a PAD if end-of-ring space is too small */ 476 if (head_to_end(cmd_head, udev->cmdr_size) < command_size) { 477 size_t pad_size = head_to_end(cmd_head, udev->cmdr_size); 478 479 entry = (void *) mb + CMDR_OFF + cmd_head; 480 tcmu_flush_dcache_range(entry, sizeof(*entry)); 481 tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_PAD); 482 tcmu_hdr_set_len(&entry->hdr.len_op, pad_size); 483 entry->hdr.cmd_id = 0; /* not used for PAD */ 484 entry->hdr.kflags = 0; 485 entry->hdr.uflags = 0; 486 487 UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size); 488 489 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */ 490 WARN_ON(cmd_head != 0); 491 } 492 493 entry = (void *) mb + CMDR_OFF + cmd_head; 494 tcmu_flush_dcache_range(entry, sizeof(*entry)); 495 tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_CMD); 496 tcmu_hdr_set_len(&entry->hdr.len_op, command_size); 497 entry->hdr.cmd_id = tcmu_cmd->cmd_id; 498 entry->hdr.kflags = 0; 499 entry->hdr.uflags = 0; 500 501 bitmap_copy(old_bitmap, udev->data_bitmap, DATA_BLOCK_BITS); 502 503 /* Handle allocating space from the data area */ 504 iov = &entry->req.iov[0]; 505 iov_cnt = 0; 506 copy_to_data_area = (se_cmd->data_direction == DMA_TO_DEVICE 507 || se_cmd->se_cmd_flags & SCF_BIDI); 508 alloc_and_scatter_data_area(udev, se_cmd->t_data_sg, 509 se_cmd->t_data_nents, &iov, &iov_cnt, copy_to_data_area); 510 entry->req.iov_cnt = iov_cnt; 511 entry->req.iov_dif_cnt = 0; 512 513 /* Handle BIDI commands */ 514 iov_cnt = 0; 515 alloc_and_scatter_data_area(udev, se_cmd->t_bidi_data_sg, 516 se_cmd->t_bidi_data_nents, &iov, &iov_cnt, false); 517 entry->req.iov_bidi_cnt = iov_cnt; 518 519 /* cmd's data_bitmap is what changed in process */ 520 bitmap_xor(tcmu_cmd->data_bitmap, old_bitmap, udev->data_bitmap, 521 DATA_BLOCK_BITS); 522 523 /* All offsets relative to mb_addr, not start of entry! */ 524 cdb_off = CMDR_OFF + cmd_head + base_command_size; 525 memcpy((void *) mb + cdb_off, se_cmd->t_task_cdb, scsi_command_size(se_cmd->t_task_cdb)); 526 entry->req.cdb_off = cdb_off; 527 tcmu_flush_dcache_range(entry, sizeof(*entry)); 528 529 UPDATE_HEAD(mb->cmd_head, command_size, udev->cmdr_size); 530 tcmu_flush_dcache_range(mb, sizeof(*mb)); 531 532 spin_unlock_irq(&udev->cmdr_lock); 533 534 /* TODO: only if FLUSH and FUA? */ 535 uio_event_notify(&udev->uio_info); 536 537 if (udev->cmd_time_out) 538 mod_timer(&udev->timeout, round_jiffies_up(jiffies + 539 msecs_to_jiffies(udev->cmd_time_out))); 540 541 return TCM_NO_SENSE; 542 } 543 544 static sense_reason_t 545 tcmu_queue_cmd(struct se_cmd *se_cmd) 546 { 547 struct se_device *se_dev = se_cmd->se_dev; 548 struct tcmu_dev *udev = TCMU_DEV(se_dev); 549 struct tcmu_cmd *tcmu_cmd; 550 sense_reason_t ret; 551 552 tcmu_cmd = tcmu_alloc_cmd(se_cmd); 553 if (!tcmu_cmd) 554 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 555 556 ret = tcmu_queue_cmd_ring(tcmu_cmd); 557 if (ret != TCM_NO_SENSE) { 558 pr_err("TCMU: Could not queue command\n"); 559 spin_lock_irq(&udev->commands_lock); 560 idr_remove(&udev->commands, tcmu_cmd->cmd_id); 561 spin_unlock_irq(&udev->commands_lock); 562 563 kmem_cache_free(tcmu_cmd_cache, tcmu_cmd); 564 } 565 566 return ret; 567 } 568 569 static void tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry *entry) 570 { 571 struct se_cmd *se_cmd = cmd->se_cmd; 572 struct tcmu_dev *udev = cmd->tcmu_dev; 573 574 if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) { 575 /* 576 * cmd has been completed already from timeout, just reclaim 577 * data area space and free cmd 578 */ 579 free_data_area(udev, cmd); 580 581 kmem_cache_free(tcmu_cmd_cache, cmd); 582 return; 583 } 584 585 if (entry->hdr.uflags & TCMU_UFLAG_UNKNOWN_OP) { 586 free_data_area(udev, cmd); 587 pr_warn("TCMU: Userspace set UNKNOWN_OP flag on se_cmd %p\n", 588 cmd->se_cmd); 589 entry->rsp.scsi_status = SAM_STAT_CHECK_CONDITION; 590 } else if (entry->rsp.scsi_status == SAM_STAT_CHECK_CONDITION) { 591 memcpy(se_cmd->sense_buffer, entry->rsp.sense_buffer, 592 se_cmd->scsi_sense_length); 593 free_data_area(udev, cmd); 594 } else if (se_cmd->se_cmd_flags & SCF_BIDI) { 595 DECLARE_BITMAP(bitmap, DATA_BLOCK_BITS); 596 597 /* Get Data-In buffer before clean up */ 598 bitmap_copy(bitmap, cmd->data_bitmap, DATA_BLOCK_BITS); 599 gather_data_area(udev, bitmap, 600 se_cmd->t_bidi_data_sg, se_cmd->t_bidi_data_nents); 601 free_data_area(udev, cmd); 602 } else if (se_cmd->data_direction == DMA_FROM_DEVICE) { 603 DECLARE_BITMAP(bitmap, DATA_BLOCK_BITS); 604 605 bitmap_copy(bitmap, cmd->data_bitmap, DATA_BLOCK_BITS); 606 gather_data_area(udev, bitmap, 607 se_cmd->t_data_sg, se_cmd->t_data_nents); 608 free_data_area(udev, cmd); 609 } else if (se_cmd->data_direction == DMA_TO_DEVICE) { 610 free_data_area(udev, cmd); 611 } else if (se_cmd->data_direction != DMA_NONE) { 612 pr_warn("TCMU: data direction was %d!\n", 613 se_cmd->data_direction); 614 } 615 616 target_complete_cmd(cmd->se_cmd, entry->rsp.scsi_status); 617 cmd->se_cmd = NULL; 618 619 kmem_cache_free(tcmu_cmd_cache, cmd); 620 } 621 622 static unsigned int tcmu_handle_completions(struct tcmu_dev *udev) 623 { 624 struct tcmu_mailbox *mb; 625 unsigned long flags; 626 int handled = 0; 627 628 if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) { 629 pr_err("ring broken, not handling completions\n"); 630 return 0; 631 } 632 633 spin_lock_irqsave(&udev->cmdr_lock, flags); 634 635 mb = udev->mb_addr; 636 tcmu_flush_dcache_range(mb, sizeof(*mb)); 637 638 while (udev->cmdr_last_cleaned != ACCESS_ONCE(mb->cmd_tail)) { 639 640 struct tcmu_cmd_entry *entry = (void *) mb + CMDR_OFF + udev->cmdr_last_cleaned; 641 struct tcmu_cmd *cmd; 642 643 tcmu_flush_dcache_range(entry, sizeof(*entry)); 644 645 if (tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_PAD) { 646 UPDATE_HEAD(udev->cmdr_last_cleaned, 647 tcmu_hdr_get_len(entry->hdr.len_op), 648 udev->cmdr_size); 649 continue; 650 } 651 WARN_ON(tcmu_hdr_get_op(entry->hdr.len_op) != TCMU_OP_CMD); 652 653 spin_lock(&udev->commands_lock); 654 cmd = idr_remove(&udev->commands, entry->hdr.cmd_id); 655 spin_unlock(&udev->commands_lock); 656 657 if (!cmd) { 658 pr_err("cmd_id not found, ring is broken\n"); 659 set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags); 660 break; 661 } 662 663 tcmu_handle_completion(cmd, entry); 664 665 UPDATE_HEAD(udev->cmdr_last_cleaned, 666 tcmu_hdr_get_len(entry->hdr.len_op), 667 udev->cmdr_size); 668 669 handled++; 670 } 671 672 if (mb->cmd_tail == mb->cmd_head) 673 del_timer(&udev->timeout); /* no more pending cmds */ 674 675 spin_unlock_irqrestore(&udev->cmdr_lock, flags); 676 677 wake_up(&udev->wait_cmdr); 678 679 return handled; 680 } 681 682 static int tcmu_check_expired_cmd(int id, void *p, void *data) 683 { 684 struct tcmu_cmd *cmd = p; 685 686 if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) 687 return 0; 688 689 if (!time_after(jiffies, cmd->deadline)) 690 return 0; 691 692 set_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags); 693 target_complete_cmd(cmd->se_cmd, SAM_STAT_CHECK_CONDITION); 694 cmd->se_cmd = NULL; 695 696 return 0; 697 } 698 699 static void tcmu_device_timedout(unsigned long data) 700 { 701 struct tcmu_dev *udev = (struct tcmu_dev *)data; 702 unsigned long flags; 703 int handled; 704 705 handled = tcmu_handle_completions(udev); 706 707 pr_warn("%d completions handled from timeout\n", handled); 708 709 spin_lock_irqsave(&udev->commands_lock, flags); 710 idr_for_each(&udev->commands, tcmu_check_expired_cmd, NULL); 711 spin_unlock_irqrestore(&udev->commands_lock, flags); 712 713 /* 714 * We don't need to wakeup threads on wait_cmdr since they have their 715 * own timeout. 716 */ 717 } 718 719 static int tcmu_attach_hba(struct se_hba *hba, u32 host_id) 720 { 721 struct tcmu_hba *tcmu_hba; 722 723 tcmu_hba = kzalloc(sizeof(struct tcmu_hba), GFP_KERNEL); 724 if (!tcmu_hba) 725 return -ENOMEM; 726 727 tcmu_hba->host_id = host_id; 728 hba->hba_ptr = tcmu_hba; 729 730 return 0; 731 } 732 733 static void tcmu_detach_hba(struct se_hba *hba) 734 { 735 kfree(hba->hba_ptr); 736 hba->hba_ptr = NULL; 737 } 738 739 static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name) 740 { 741 struct tcmu_dev *udev; 742 743 udev = kzalloc(sizeof(struct tcmu_dev), GFP_KERNEL); 744 if (!udev) 745 return NULL; 746 747 udev->name = kstrdup(name, GFP_KERNEL); 748 if (!udev->name) { 749 kfree(udev); 750 return NULL; 751 } 752 753 udev->hba = hba; 754 udev->cmd_time_out = TCMU_TIME_OUT; 755 756 init_waitqueue_head(&udev->wait_cmdr); 757 spin_lock_init(&udev->cmdr_lock); 758 759 idr_init(&udev->commands); 760 spin_lock_init(&udev->commands_lock); 761 762 setup_timer(&udev->timeout, tcmu_device_timedout, 763 (unsigned long)udev); 764 765 return &udev->se_dev; 766 } 767 768 static int tcmu_irqcontrol(struct uio_info *info, s32 irq_on) 769 { 770 struct tcmu_dev *tcmu_dev = container_of(info, struct tcmu_dev, uio_info); 771 772 tcmu_handle_completions(tcmu_dev); 773 774 return 0; 775 } 776 777 /* 778 * mmap code from uio.c. Copied here because we want to hook mmap() 779 * and this stuff must come along. 780 */ 781 static int tcmu_find_mem_index(struct vm_area_struct *vma) 782 { 783 struct tcmu_dev *udev = vma->vm_private_data; 784 struct uio_info *info = &udev->uio_info; 785 786 if (vma->vm_pgoff < MAX_UIO_MAPS) { 787 if (info->mem[vma->vm_pgoff].size == 0) 788 return -1; 789 return (int)vma->vm_pgoff; 790 } 791 return -1; 792 } 793 794 static int tcmu_vma_fault(struct vm_fault *vmf) 795 { 796 struct tcmu_dev *udev = vmf->vma->vm_private_data; 797 struct uio_info *info = &udev->uio_info; 798 struct page *page; 799 unsigned long offset; 800 void *addr; 801 802 int mi = tcmu_find_mem_index(vmf->vma); 803 if (mi < 0) 804 return VM_FAULT_SIGBUS; 805 806 /* 807 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE 808 * to use mem[N]. 809 */ 810 offset = (vmf->pgoff - mi) << PAGE_SHIFT; 811 812 addr = (void *)(unsigned long)info->mem[mi].addr + offset; 813 if (info->mem[mi].memtype == UIO_MEM_LOGICAL) 814 page = virt_to_page(addr); 815 else 816 page = vmalloc_to_page(addr); 817 get_page(page); 818 vmf->page = page; 819 return 0; 820 } 821 822 static const struct vm_operations_struct tcmu_vm_ops = { 823 .fault = tcmu_vma_fault, 824 }; 825 826 static int tcmu_mmap(struct uio_info *info, struct vm_area_struct *vma) 827 { 828 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info); 829 830 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; 831 vma->vm_ops = &tcmu_vm_ops; 832 833 vma->vm_private_data = udev; 834 835 /* Ensure the mmap is exactly the right size */ 836 if (vma_pages(vma) != (TCMU_RING_SIZE >> PAGE_SHIFT)) 837 return -EINVAL; 838 839 return 0; 840 } 841 842 static int tcmu_open(struct uio_info *info, struct inode *inode) 843 { 844 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info); 845 846 /* O_EXCL not supported for char devs, so fake it? */ 847 if (test_and_set_bit(TCMU_DEV_BIT_OPEN, &udev->flags)) 848 return -EBUSY; 849 850 pr_debug("open\n"); 851 852 return 0; 853 } 854 855 static int tcmu_release(struct uio_info *info, struct inode *inode) 856 { 857 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info); 858 859 clear_bit(TCMU_DEV_BIT_OPEN, &udev->flags); 860 861 pr_debug("close\n"); 862 863 return 0; 864 } 865 866 static int tcmu_netlink_event(enum tcmu_genl_cmd cmd, const char *name, int minor) 867 { 868 struct sk_buff *skb; 869 void *msg_header; 870 int ret = -ENOMEM; 871 872 skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL); 873 if (!skb) 874 return ret; 875 876 msg_header = genlmsg_put(skb, 0, 0, &tcmu_genl_family, 0, cmd); 877 if (!msg_header) 878 goto free_skb; 879 880 ret = nla_put_string(skb, TCMU_ATTR_DEVICE, name); 881 if (ret < 0) 882 goto free_skb; 883 884 ret = nla_put_u32(skb, TCMU_ATTR_MINOR, minor); 885 if (ret < 0) 886 goto free_skb; 887 888 genlmsg_end(skb, msg_header); 889 890 ret = genlmsg_multicast_allns(&tcmu_genl_family, skb, 0, 891 TCMU_MCGRP_CONFIG, GFP_KERNEL); 892 893 /* We don't care if no one is listening */ 894 if (ret == -ESRCH) 895 ret = 0; 896 897 return ret; 898 free_skb: 899 nlmsg_free(skb); 900 return ret; 901 } 902 903 static int tcmu_configure_device(struct se_device *dev) 904 { 905 struct tcmu_dev *udev = TCMU_DEV(dev); 906 struct tcmu_hba *hba = udev->hba->hba_ptr; 907 struct uio_info *info; 908 struct tcmu_mailbox *mb; 909 size_t size; 910 size_t used; 911 int ret = 0; 912 char *str; 913 914 info = &udev->uio_info; 915 916 size = snprintf(NULL, 0, "tcm-user/%u/%s/%s", hba->host_id, udev->name, 917 udev->dev_config); 918 size += 1; /* for \0 */ 919 str = kmalloc(size, GFP_KERNEL); 920 if (!str) 921 return -ENOMEM; 922 923 used = snprintf(str, size, "tcm-user/%u/%s", hba->host_id, udev->name); 924 925 if (udev->dev_config[0]) 926 snprintf(str + used, size - used, "/%s", udev->dev_config); 927 928 info->name = str; 929 930 udev->mb_addr = vzalloc(TCMU_RING_SIZE); 931 if (!udev->mb_addr) { 932 ret = -ENOMEM; 933 goto err_vzalloc; 934 } 935 936 /* mailbox fits in first part of CMDR space */ 937 udev->cmdr_size = CMDR_SIZE - CMDR_OFF; 938 udev->data_off = CMDR_SIZE; 939 udev->data_size = TCMU_RING_SIZE - CMDR_SIZE; 940 941 mb = udev->mb_addr; 942 mb->version = TCMU_MAILBOX_VERSION; 943 mb->flags = TCMU_MAILBOX_FLAG_CAP_OOOC; 944 mb->cmdr_off = CMDR_OFF; 945 mb->cmdr_size = udev->cmdr_size; 946 947 WARN_ON(!PAGE_ALIGNED(udev->data_off)); 948 WARN_ON(udev->data_size % PAGE_SIZE); 949 WARN_ON(udev->data_size % DATA_BLOCK_SIZE); 950 951 info->version = __stringify(TCMU_MAILBOX_VERSION); 952 953 info->mem[0].name = "tcm-user command & data buffer"; 954 info->mem[0].addr = (phys_addr_t)(uintptr_t)udev->mb_addr; 955 info->mem[0].size = TCMU_RING_SIZE; 956 info->mem[0].memtype = UIO_MEM_VIRTUAL; 957 958 info->irqcontrol = tcmu_irqcontrol; 959 info->irq = UIO_IRQ_CUSTOM; 960 961 info->mmap = tcmu_mmap; 962 info->open = tcmu_open; 963 info->release = tcmu_release; 964 965 ret = uio_register_device(tcmu_root_device, info); 966 if (ret) 967 goto err_register; 968 969 /* User can set hw_block_size before enable the device */ 970 if (dev->dev_attrib.hw_block_size == 0) 971 dev->dev_attrib.hw_block_size = 512; 972 /* Other attributes can be configured in userspace */ 973 if (!dev->dev_attrib.hw_max_sectors) 974 dev->dev_attrib.hw_max_sectors = 128; 975 dev->dev_attrib.hw_queue_depth = 128; 976 977 ret = tcmu_netlink_event(TCMU_CMD_ADDED_DEVICE, udev->uio_info.name, 978 udev->uio_info.uio_dev->minor); 979 if (ret) 980 goto err_netlink; 981 982 return 0; 983 984 err_netlink: 985 uio_unregister_device(&udev->uio_info); 986 err_register: 987 vfree(udev->mb_addr); 988 err_vzalloc: 989 kfree(info->name); 990 991 return ret; 992 } 993 994 static int tcmu_check_and_free_pending_cmd(struct tcmu_cmd *cmd) 995 { 996 if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) { 997 kmem_cache_free(tcmu_cmd_cache, cmd); 998 return 0; 999 } 1000 return -EINVAL; 1001 } 1002 1003 static void tcmu_dev_call_rcu(struct rcu_head *p) 1004 { 1005 struct se_device *dev = container_of(p, struct se_device, rcu_head); 1006 struct tcmu_dev *udev = TCMU_DEV(dev); 1007 1008 kfree(udev); 1009 } 1010 1011 static bool tcmu_dev_configured(struct tcmu_dev *udev) 1012 { 1013 return udev->uio_info.uio_dev ? true : false; 1014 } 1015 1016 static void tcmu_free_device(struct se_device *dev) 1017 { 1018 struct tcmu_dev *udev = TCMU_DEV(dev); 1019 struct tcmu_cmd *cmd; 1020 bool all_expired = true; 1021 int i; 1022 1023 del_timer_sync(&udev->timeout); 1024 1025 vfree(udev->mb_addr); 1026 1027 /* Upper layer should drain all requests before calling this */ 1028 spin_lock_irq(&udev->commands_lock); 1029 idr_for_each_entry(&udev->commands, cmd, i) { 1030 if (tcmu_check_and_free_pending_cmd(cmd) != 0) 1031 all_expired = false; 1032 } 1033 idr_destroy(&udev->commands); 1034 spin_unlock_irq(&udev->commands_lock); 1035 WARN_ON(!all_expired); 1036 1037 if (tcmu_dev_configured(udev)) { 1038 tcmu_netlink_event(TCMU_CMD_REMOVED_DEVICE, udev->uio_info.name, 1039 udev->uio_info.uio_dev->minor); 1040 1041 uio_unregister_device(&udev->uio_info); 1042 kfree(udev->uio_info.name); 1043 kfree(udev->name); 1044 } 1045 call_rcu(&dev->rcu_head, tcmu_dev_call_rcu); 1046 } 1047 1048 enum { 1049 Opt_dev_config, Opt_dev_size, Opt_hw_block_size, Opt_hw_max_sectors, 1050 Opt_err, 1051 }; 1052 1053 static match_table_t tokens = { 1054 {Opt_dev_config, "dev_config=%s"}, 1055 {Opt_dev_size, "dev_size=%u"}, 1056 {Opt_hw_block_size, "hw_block_size=%u"}, 1057 {Opt_hw_max_sectors, "hw_max_sectors=%u"}, 1058 {Opt_err, NULL} 1059 }; 1060 1061 static int tcmu_set_dev_attrib(substring_t *arg, u32 *dev_attrib) 1062 { 1063 unsigned long tmp_ul; 1064 char *arg_p; 1065 int ret; 1066 1067 arg_p = match_strdup(arg); 1068 if (!arg_p) 1069 return -ENOMEM; 1070 1071 ret = kstrtoul(arg_p, 0, &tmp_ul); 1072 kfree(arg_p); 1073 if (ret < 0) { 1074 pr_err("kstrtoul() failed for dev attrib\n"); 1075 return ret; 1076 } 1077 if (!tmp_ul) { 1078 pr_err("dev attrib must be nonzero\n"); 1079 return -EINVAL; 1080 } 1081 *dev_attrib = tmp_ul; 1082 return 0; 1083 } 1084 1085 static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev, 1086 const char *page, ssize_t count) 1087 { 1088 struct tcmu_dev *udev = TCMU_DEV(dev); 1089 char *orig, *ptr, *opts, *arg_p; 1090 substring_t args[MAX_OPT_ARGS]; 1091 int ret = 0, token; 1092 1093 opts = kstrdup(page, GFP_KERNEL); 1094 if (!opts) 1095 return -ENOMEM; 1096 1097 orig = opts; 1098 1099 while ((ptr = strsep(&opts, ",\n")) != NULL) { 1100 if (!*ptr) 1101 continue; 1102 1103 token = match_token(ptr, tokens, args); 1104 switch (token) { 1105 case Opt_dev_config: 1106 if (match_strlcpy(udev->dev_config, &args[0], 1107 TCMU_CONFIG_LEN) == 0) { 1108 ret = -EINVAL; 1109 break; 1110 } 1111 pr_debug("TCMU: Referencing Path: %s\n", udev->dev_config); 1112 break; 1113 case Opt_dev_size: 1114 arg_p = match_strdup(&args[0]); 1115 if (!arg_p) { 1116 ret = -ENOMEM; 1117 break; 1118 } 1119 ret = kstrtoul(arg_p, 0, (unsigned long *) &udev->dev_size); 1120 kfree(arg_p); 1121 if (ret < 0) 1122 pr_err("kstrtoul() failed for dev_size=\n"); 1123 break; 1124 case Opt_hw_block_size: 1125 ret = tcmu_set_dev_attrib(&args[0], 1126 &(dev->dev_attrib.hw_block_size)); 1127 break; 1128 case Opt_hw_max_sectors: 1129 ret = tcmu_set_dev_attrib(&args[0], 1130 &(dev->dev_attrib.hw_max_sectors)); 1131 break; 1132 default: 1133 break; 1134 } 1135 1136 if (ret) 1137 break; 1138 } 1139 1140 kfree(orig); 1141 return (!ret) ? count : ret; 1142 } 1143 1144 static ssize_t tcmu_show_configfs_dev_params(struct se_device *dev, char *b) 1145 { 1146 struct tcmu_dev *udev = TCMU_DEV(dev); 1147 ssize_t bl = 0; 1148 1149 bl = sprintf(b + bl, "Config: %s ", 1150 udev->dev_config[0] ? udev->dev_config : "NULL"); 1151 bl += sprintf(b + bl, "Size: %zu\n", udev->dev_size); 1152 1153 return bl; 1154 } 1155 1156 static sector_t tcmu_get_blocks(struct se_device *dev) 1157 { 1158 struct tcmu_dev *udev = TCMU_DEV(dev); 1159 1160 return div_u64(udev->dev_size - dev->dev_attrib.block_size, 1161 dev->dev_attrib.block_size); 1162 } 1163 1164 static sense_reason_t 1165 tcmu_parse_cdb(struct se_cmd *cmd) 1166 { 1167 return passthrough_parse_cdb(cmd, tcmu_queue_cmd); 1168 } 1169 1170 static ssize_t tcmu_cmd_time_out_show(struct config_item *item, char *page) 1171 { 1172 struct se_dev_attrib *da = container_of(to_config_group(item), 1173 struct se_dev_attrib, da_group); 1174 struct tcmu_dev *udev = container_of(da->da_dev, 1175 struct tcmu_dev, se_dev); 1176 1177 return snprintf(page, PAGE_SIZE, "%lu\n", udev->cmd_time_out / MSEC_PER_SEC); 1178 } 1179 1180 static ssize_t tcmu_cmd_time_out_store(struct config_item *item, const char *page, 1181 size_t count) 1182 { 1183 struct se_dev_attrib *da = container_of(to_config_group(item), 1184 struct se_dev_attrib, da_group); 1185 struct tcmu_dev *udev = container_of(da->da_dev, 1186 struct tcmu_dev, se_dev); 1187 u32 val; 1188 int ret; 1189 1190 if (da->da_dev->export_count) { 1191 pr_err("Unable to set tcmu cmd_time_out while exports exist\n"); 1192 return -EINVAL; 1193 } 1194 1195 ret = kstrtou32(page, 0, &val); 1196 if (ret < 0) 1197 return ret; 1198 1199 if (!val) { 1200 pr_err("Illegal value for cmd_time_out\n"); 1201 return -EINVAL; 1202 } 1203 1204 udev->cmd_time_out = val * MSEC_PER_SEC; 1205 return count; 1206 } 1207 CONFIGFS_ATTR(tcmu_, cmd_time_out); 1208 1209 static struct configfs_attribute **tcmu_attrs; 1210 1211 static struct target_backend_ops tcmu_ops = { 1212 .name = "user", 1213 .owner = THIS_MODULE, 1214 .transport_flags = TRANSPORT_FLAG_PASSTHROUGH, 1215 .attach_hba = tcmu_attach_hba, 1216 .detach_hba = tcmu_detach_hba, 1217 .alloc_device = tcmu_alloc_device, 1218 .configure_device = tcmu_configure_device, 1219 .free_device = tcmu_free_device, 1220 .parse_cdb = tcmu_parse_cdb, 1221 .set_configfs_dev_params = tcmu_set_configfs_dev_params, 1222 .show_configfs_dev_params = tcmu_show_configfs_dev_params, 1223 .get_device_type = sbc_get_device_type, 1224 .get_blocks = tcmu_get_blocks, 1225 .tb_dev_attrib_attrs = NULL, 1226 }; 1227 1228 static int __init tcmu_module_init(void) 1229 { 1230 int ret, i, len = 0; 1231 1232 BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry) % TCMU_OP_ALIGN_SIZE) != 0); 1233 1234 tcmu_cmd_cache = kmem_cache_create("tcmu_cmd_cache", 1235 sizeof(struct tcmu_cmd), 1236 __alignof__(struct tcmu_cmd), 1237 0, NULL); 1238 if (!tcmu_cmd_cache) 1239 return -ENOMEM; 1240 1241 tcmu_root_device = root_device_register("tcm_user"); 1242 if (IS_ERR(tcmu_root_device)) { 1243 ret = PTR_ERR(tcmu_root_device); 1244 goto out_free_cache; 1245 } 1246 1247 ret = genl_register_family(&tcmu_genl_family); 1248 if (ret < 0) { 1249 goto out_unreg_device; 1250 } 1251 1252 for (i = 0; passthrough_attrib_attrs[i] != NULL; i++) { 1253 len += sizeof(struct configfs_attribute *); 1254 } 1255 len += sizeof(struct configfs_attribute *) * 2; 1256 1257 tcmu_attrs = kzalloc(len, GFP_KERNEL); 1258 if (!tcmu_attrs) { 1259 ret = -ENOMEM; 1260 goto out_unreg_genl; 1261 } 1262 1263 for (i = 0; passthrough_attrib_attrs[i] != NULL; i++) { 1264 tcmu_attrs[i] = passthrough_attrib_attrs[i]; 1265 } 1266 tcmu_attrs[i] = &tcmu_attr_cmd_time_out; 1267 tcmu_ops.tb_dev_attrib_attrs = tcmu_attrs; 1268 1269 ret = transport_backend_register(&tcmu_ops); 1270 if (ret) 1271 goto out_attrs; 1272 1273 return 0; 1274 1275 out_attrs: 1276 kfree(tcmu_attrs); 1277 out_unreg_genl: 1278 genl_unregister_family(&tcmu_genl_family); 1279 out_unreg_device: 1280 root_device_unregister(tcmu_root_device); 1281 out_free_cache: 1282 kmem_cache_destroy(tcmu_cmd_cache); 1283 1284 return ret; 1285 } 1286 1287 static void __exit tcmu_module_exit(void) 1288 { 1289 target_backend_unregister(&tcmu_ops); 1290 kfree(tcmu_attrs); 1291 genl_unregister_family(&tcmu_genl_family); 1292 root_device_unregister(tcmu_root_device); 1293 kmem_cache_destroy(tcmu_cmd_cache); 1294 } 1295 1296 MODULE_DESCRIPTION("TCM USER subsystem plugin"); 1297 MODULE_AUTHOR("Shaohua Li <shli@kernel.org>"); 1298 MODULE_AUTHOR("Andy Grover <agrover@redhat.com>"); 1299 MODULE_LICENSE("GPL"); 1300 1301 module_init(tcmu_module_init); 1302 module_exit(tcmu_module_exit); 1303