drivers/target/target_core_user.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2013 Shaohua Li <shli@kernel.org>
   4  * Copyright (C) 2014 Red Hat, Inc.
   5  * Copyright (C) 2015 Arrikto, Inc.
   6  * Copyright (C) 2017 Chinamobile, Inc.
   7  */
   8
   9 #include <linux/spinlock.h>
  10 #include <linux/module.h>
  11 #include <linux/idr.h>
  12 #include <linux/kernel.h>
  13 #include <linux/timer.h>
  14 #include <linux/parser.h>
  15 #include <linux/vmalloc.h>
  16 #include <linux/uio_driver.h>
  17 #include <linux/radix-tree.h>
  18 #include <linux/stringify.h>
  19 #include <linux/bitops.h>
  20 #include <linux/highmem.h>
  21 #include <linux/configfs.h>
  22 #include <linux/mutex.h>
  23 #include <linux/workqueue.h>
  24 #include <net/genetlink.h>
  25 #include <scsi/scsi_common.h>
  26 #include <scsi/scsi_proto.h>
  27 #include <target/target_core_base.h>
  28 #include <target/target_core_fabric.h>
  29 #include <target/target_core_backend.h>
  30
  31 #include <linux/target_core_user.h>
  32
  33 /**
  34  * DOC: Userspace I/O
  35  * Userspace I/O
  36  * -------------
  37  *
  38  * Define a shared-memory interface for LIO to pass SCSI commands and
  39  * data to userspace for processing. This is to allow backends that
  40  * are too complex for in-kernel support to be possible.
  41  *
  42  * It uses the UIO framework to do a lot of the device-creation and
  43  * introspection work for us.
  44  *
  45  * See the .h file for how the ring is laid out. Note that while the
  46  * command ring is defined, the particulars of the data area are
  47  * not. Offset values in the command entry point to other locations
  48  * internal to the mmap-ed area. There is separate space outside the
  49  * command ring for data buffers. This leaves maximum flexibility for
  50  * moving buffer allocations, or even page flipping or other
  51  * allocation techniques, without altering the command ring layout.
  52  *
  53  * SECURITY:
  54  * The user process must be assumed to be malicious. There's no way to
  55  * prevent it breaking the command ring protocol if it wants, but in
  56  * order to prevent other issues we must only ever read *data* from
  57  * the shared memory area, not offsets or sizes. This applies to
  58  * command ring entries as well as the mailbox. Extra code needed for
  59  * this may have a 'UAM' comment.
  60  */
  61
  62 #define TCMU_TIME_OUT (30 * MSEC_PER_SEC)
  63
  64 /* For cmd area, the size is fixed 8MB */
  65 #define CMDR_SIZE (8 * 1024 * 1024)
  66
  67 /*
  68  * For data area, the block size is PAGE_SIZE and
  69  * the total size is 256K * PAGE_SIZE.
  70  */
  71 #define DATA_BLOCK_SIZE PAGE_SIZE
  72 #define DATA_BLOCK_SHIFT PAGE_SHIFT
  73 #define DATA_BLOCK_BITS_DEF (256 * 1024)
  74
  75 #define TCMU_MBS_TO_BLOCKS(_mbs) (_mbs << (20 - DATA_BLOCK_SHIFT))
  76 #define TCMU_BLOCKS_TO_MBS(_blocks) (_blocks >> (20 - DATA_BLOCK_SHIFT))
  77
  78 /*
  79  * Default number of global data blocks(512K * PAGE_SIZE)
  80  * when the unmap thread will be started.
  81  */
  82 #define TCMU_GLOBAL_MAX_BLOCKS_DEF (512 * 1024)
  83
  84 static u8 tcmu_kern_cmd_reply_supported;
  85 static u8 tcmu_netlink_blocked;
  86
  87 static struct device *tcmu_root_device;
  88
  89 struct tcmu_hba {
  90         u32 host_id;
  91 };
  92
  93 #define TCMU_CONFIG_LEN 256
  94
  95 static DEFINE_MUTEX(tcmu_nl_cmd_mutex);
  96 static LIST_HEAD(tcmu_nl_cmd_list);
  97
  98 struct tcmu_dev;
  99
 100 struct tcmu_nl_cmd {
 101         /* wake up thread waiting for reply */
 102         struct completion complete;
 103         struct list_head nl_list;
 104         struct tcmu_dev *udev;
 105         int cmd;
 106         int status;
 107 };
 108
 109 struct tcmu_dev {
 110         struct list_head node;
 111         struct kref kref;
 112
 113         struct se_device se_dev;
 114
 115         char *name;
 116         struct se_hba *hba;
 117
 118 #define TCMU_DEV_BIT_OPEN 0
 119 #define TCMU_DEV_BIT_BROKEN 1
 120 #define TCMU_DEV_BIT_BLOCKED 2
 121 #define TCMU_DEV_BIT_TMR_NOTIFY 3
 122         unsigned long flags;
 123
 124         struct uio_info uio_info;
 125
 126         struct inode *inode;
 127
 128         struct tcmu_mailbox *mb_addr;
 129         uint64_t dev_size;
 130         u32 cmdr_size;
 131         u32 cmdr_last_cleaned;
 132         /* Offset of data area from start of mb */
 133         /* Must add data_off and mb_addr to get the address */
 134         size_t data_off;
 135         size_t data_size;
 136         uint32_t max_blocks;
 137         size_t ring_size;
 138
 139         struct mutex cmdr_lock;
 140         struct list_head qfull_queue;
 141         struct list_head tmr_queue;
 142
 143         uint32_t dbi_max;
 144         uint32_t dbi_thresh;
 145         unsigned long *data_bitmap;
 146         struct radix_tree_root data_blocks;
 147
 148         struct idr commands;
 149
 150         struct timer_list cmd_timer;
 151         unsigned int cmd_time_out;
 152         struct list_head inflight_queue;
 153
 154         struct timer_list qfull_timer;
 155         int qfull_time_out;
 156
 157         struct list_head timedout_entry;
 158
 159         struct tcmu_nl_cmd curr_nl_cmd;
 160
 161         char dev_config[TCMU_CONFIG_LEN];
 162
 163         int nl_reply_supported;
 164 };
 165
 166 #define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev)
 167
 168 #define CMDR_OFF sizeof(struct tcmu_mailbox)
 169
 170 struct tcmu_cmd {
 171         struct se_cmd *se_cmd;
 172         struct tcmu_dev *tcmu_dev;
 173         struct list_head queue_entry;
 174
 175         uint16_t cmd_id;
 176
 177         /* Can't use se_cmd when cleaning up expired cmds, because if
 178            cmd has been completed then accessing se_cmd is off limits */
 179         uint32_t dbi_cnt;
 180         uint32_t dbi_bidi_cnt;
 181         uint32_t dbi_cur;
 182         uint32_t *dbi;
 183
 184         uint32_t data_len_bidi;
 185
 186         unsigned long deadline;
 187
 188 #define TCMU_CMD_BIT_EXPIRED 0
 189         unsigned long flags;
 190 };
 191
 192 struct tcmu_tmr {
 193         struct list_head queue_entry;
 194
 195         uint8_t tmr_type;
 196         uint32_t tmr_cmd_cnt;
 197         int16_t tmr_cmd_ids[0];
 198 };
 199
 200 /*
 201  * To avoid dead lock the mutex lock order should always be:
 202  *
 203  * mutex_lock(&root_udev_mutex);
 204  * ...
 205  * mutex_lock(&tcmu_dev->cmdr_lock);
 206  * mutex_unlock(&tcmu_dev->cmdr_lock);
 207  * ...
 208  * mutex_unlock(&root_udev_mutex);
 209  */
 210 static DEFINE_MUTEX(root_udev_mutex);
 211 static LIST_HEAD(root_udev);
 212
 213 static DEFINE_SPINLOCK(timed_out_udevs_lock);
 214 static LIST_HEAD(timed_out_udevs);
 215
 216 static struct kmem_cache *tcmu_cmd_cache;
 217
 218 static atomic_t global_db_count = ATOMIC_INIT(0);
 219 static struct delayed_work tcmu_unmap_work;
 220 static int tcmu_global_max_blocks = TCMU_GLOBAL_MAX_BLOCKS_DEF;
 221
 222 static int tcmu_set_global_max_data_area(const char *str,
 223                                          const struct kernel_param *kp)
 224 {
 225         int ret, max_area_mb;
 226
 227         ret = kstrtoint(str, 10, &max_area_mb);
 228         if (ret)
 229                 return -EINVAL;
 230
 231         if (max_area_mb <= 0) {
 232                 pr_err("global_max_data_area must be larger than 0.\n");
 233                 return -EINVAL;
 234         }
 235
 236         tcmu_global_max_blocks = TCMU_MBS_TO_BLOCKS(max_area_mb);
 237         if (atomic_read(&global_db_count) > tcmu_global_max_blocks)
 238                 schedule_delayed_work(&tcmu_unmap_work, 0);
 239         else
 240                 cancel_delayed_work_sync(&tcmu_unmap_work);
 241
 242         return 0;
 243 }
 244
 245 static int tcmu_get_global_max_data_area(char *buffer,
 246                                          const struct kernel_param *kp)
 247 {
 248         return sprintf(buffer, "%d\n", TCMU_BLOCKS_TO_MBS(tcmu_global_max_blocks));
 249 }
 250
 251 static const struct kernel_param_ops tcmu_global_max_data_area_op = {
 252         .set = tcmu_set_global_max_data_area,
 253         .get = tcmu_get_global_max_data_area,
 254 };
 255
 256 module_param_cb(global_max_data_area_mb, &tcmu_global_max_data_area_op, NULL,
 257                 S_IWUSR | S_IRUGO);
 258 MODULE_PARM_DESC(global_max_data_area_mb,
 259                  "Max MBs allowed to be allocated to all the tcmu device's "
 260                  "data areas.");
 261
 262 static int tcmu_get_block_netlink(char *buffer,
 263                                   const struct kernel_param *kp)
 264 {
 265         return sprintf(buffer, "%s\n", tcmu_netlink_blocked ?
 266                        "blocked" : "unblocked");
 267 }
 268
 269 static int tcmu_set_block_netlink(const char *str,
 270                                   const struct kernel_param *kp)
 271 {
 272         int ret;
 273         u8 val;
 274
 275         ret = kstrtou8(str, 0, &val);
 276         if (ret < 0)
 277                 return ret;
 278
 279         if (val > 1) {
 280                 pr_err("Invalid block netlink value %u\n", val);
 281                 return -EINVAL;
 282         }
 283
 284         tcmu_netlink_blocked = val;
 285         return 0;
 286 }
 287
 288 static const struct kernel_param_ops tcmu_block_netlink_op = {
 289         .set = tcmu_set_block_netlink,
 290         .get = tcmu_get_block_netlink,
 291 };
 292
 293 module_param_cb(block_netlink, &tcmu_block_netlink_op, NULL, S_IWUSR | S_IRUGO);
 294 MODULE_PARM_DESC(block_netlink, "Block new netlink commands.");
 295
 296 static int tcmu_fail_netlink_cmd(struct tcmu_nl_cmd *nl_cmd)
 297 {
 298         struct tcmu_dev *udev = nl_cmd->udev;
 299
 300         if (!tcmu_netlink_blocked) {
 301                 pr_err("Could not reset device's netlink interface. Netlink is not blocked.\n");
 302                 return -EBUSY;
 303         }
 304
 305         if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
 306                 pr_debug("Aborting nl cmd %d on %s\n", nl_cmd->cmd, udev->name);
 307                 nl_cmd->status = -EINTR;
 308                 list_del(&nl_cmd->nl_list);
 309                 complete(&nl_cmd->complete);
 310         }
 311         return 0;
 312 }
 313
 314 static int tcmu_set_reset_netlink(const char *str,
 315                                   const struct kernel_param *kp)
 316 {
 317         struct tcmu_nl_cmd *nl_cmd, *tmp_cmd;
 318         int ret;
 319         u8 val;
 320
 321         ret = kstrtou8(str, 0, &val);
 322         if (ret < 0)
 323                 return ret;
 324
 325         if (val != 1) {
 326                 pr_err("Invalid reset netlink value %u\n", val);
 327                 return -EINVAL;
 328         }
 329
 330         mutex_lock(&tcmu_nl_cmd_mutex);
 331         list_for_each_entry_safe(nl_cmd, tmp_cmd, &tcmu_nl_cmd_list, nl_list) {
 332                 ret = tcmu_fail_netlink_cmd(nl_cmd);
 333                 if (ret)
 334                         break;
 335         }
 336         mutex_unlock(&tcmu_nl_cmd_mutex);
 337
 338         return ret;
 339 }
 340
 341 static const struct kernel_param_ops tcmu_reset_netlink_op = {
 342         .set = tcmu_set_reset_netlink,
 343 };
 344
 345 module_param_cb(reset_netlink, &tcmu_reset_netlink_op, NULL, S_IWUSR);
 346 MODULE_PARM_DESC(reset_netlink, "Reset netlink commands.");
 347
 348 /* multicast group */
 349 enum tcmu_multicast_groups {
 350         TCMU_MCGRP_CONFIG,
 351 };
 352
 353 static const struct genl_multicast_group tcmu_mcgrps[] = {
 354         [TCMU_MCGRP_CONFIG] = { .name = "config", },
 355 };
 356
 357 static struct nla_policy tcmu_attr_policy[TCMU_ATTR_MAX+1] = {
 358         [TCMU_ATTR_DEVICE]      = { .type = NLA_STRING },
 359         [TCMU_ATTR_MINOR]       = { .type = NLA_U32 },
 360         [TCMU_ATTR_CMD_STATUS]  = { .type = NLA_S32 },
 361         [TCMU_ATTR_DEVICE_ID]   = { .type = NLA_U32 },
 362         [TCMU_ATTR_SUPP_KERN_CMD_REPLY] = { .type = NLA_U8 },
 363 };
 364
 365 static int tcmu_genl_cmd_done(struct genl_info *info, int completed_cmd)
 366 {
 367         struct tcmu_dev *udev = NULL;
 368         struct tcmu_nl_cmd *nl_cmd;
 369         int dev_id, rc, ret = 0;
 370
 371         if (!info->attrs[TCMU_ATTR_CMD_STATUS] ||
 372             !info->attrs[TCMU_ATTR_DEVICE_ID]) {
 373                 printk(KERN_ERR "TCMU_ATTR_CMD_STATUS or TCMU_ATTR_DEVICE_ID not set, doing nothing\n");
 374                 return -EINVAL;
 375         }
 376
 377         dev_id = nla_get_u32(info->attrs[TCMU_ATTR_DEVICE_ID]);
 378         rc = nla_get_s32(info->attrs[TCMU_ATTR_CMD_STATUS]);
 379
 380         mutex_lock(&tcmu_nl_cmd_mutex);
 381         list_for_each_entry(nl_cmd, &tcmu_nl_cmd_list, nl_list) {
 382                 if (nl_cmd->udev->se_dev.dev_index == dev_id) {
 383                         udev = nl_cmd->udev;
 384                         break;
 385                 }
 386         }
 387
 388         if (!udev) {
 389                 pr_err("tcmu nl cmd %u/%d completion could not find device with dev id %u.\n",
 390                        completed_cmd, rc, dev_id);
 391                 ret = -ENODEV;
 392                 goto unlock;
 393         }
 394         list_del(&nl_cmd->nl_list);
 395
 396         pr_debug("%s genl cmd done got id %d curr %d done %d rc %d stat %d\n",
 397                  udev->name, dev_id, nl_cmd->cmd, completed_cmd, rc,
 398                  nl_cmd->status);
 399
 400         if (nl_cmd->cmd != completed_cmd) {
 401                 pr_err("Mismatched commands on %s (Expecting reply for %d. Current %d).\n",
 402                        udev->name, completed_cmd, nl_cmd->cmd);
 403                 ret = -EINVAL;
 404                 goto unlock;
 405         }
 406
 407         nl_cmd->status = rc;
 408         complete(&nl_cmd->complete);
 409 unlock:
 410         mutex_unlock(&tcmu_nl_cmd_mutex);
 411         return ret;
 412 }
 413
 414 static int tcmu_genl_rm_dev_done(struct sk_buff *skb, struct genl_info *info)
 415 {
 416         return tcmu_genl_cmd_done(info, TCMU_CMD_REMOVED_DEVICE);
 417 }
 418
 419 static int tcmu_genl_add_dev_done(struct sk_buff *skb, struct genl_info *info)
 420 {
 421         return tcmu_genl_cmd_done(info, TCMU_CMD_ADDED_DEVICE);
 422 }
 423
 424 static int tcmu_genl_reconfig_dev_done(struct sk_buff *skb,
 425                                        struct genl_info *info)
 426 {
 427         return tcmu_genl_cmd_done(info, TCMU_CMD_RECONFIG_DEVICE);
 428 }
 429
 430 static int tcmu_genl_set_features(struct sk_buff *skb, struct genl_info *info)
 431 {
 432         if (info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]) {
 433                 tcmu_kern_cmd_reply_supported  =
 434                         nla_get_u8(info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]);
 435                 printk(KERN_INFO "tcmu daemon: command reply support %u.\n",
 436                        tcmu_kern_cmd_reply_supported);
 437         }
 438
 439         return 0;
 440 }
 441
 442 static const struct genl_small_ops tcmu_genl_ops[] = {
 443         {
 444                 .cmd    = TCMU_CMD_SET_FEATURES,
 445                 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 446                 .flags  = GENL_ADMIN_PERM,
 447                 .doit   = tcmu_genl_set_features,
 448         },
 449         {
 450                 .cmd    = TCMU_CMD_ADDED_DEVICE_DONE,
 451                 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 452                 .flags  = GENL_ADMIN_PERM,
 453                 .doit   = tcmu_genl_add_dev_done,
 454         },
 455         {
 456                 .cmd    = TCMU_CMD_REMOVED_DEVICE_DONE,
 457                 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 458                 .flags  = GENL_ADMIN_PERM,
 459                 .doit   = tcmu_genl_rm_dev_done,
 460         },
 461         {
 462                 .cmd    = TCMU_CMD_RECONFIG_DEVICE_DONE,
 463                 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 464                 .flags  = GENL_ADMIN_PERM,
 465                 .doit   = tcmu_genl_reconfig_dev_done,
 466         },
 467 };
 468
 469 /* Our generic netlink family */
 470 static struct genl_family tcmu_genl_family __ro_after_init = {
 471         .module = THIS_MODULE,
 472         .hdrsize = 0,
 473         .name = "TCM-USER",
 474         .version = 2,
 475         .maxattr = TCMU_ATTR_MAX,
 476         .policy = tcmu_attr_policy,
 477         .mcgrps = tcmu_mcgrps,
 478         .n_mcgrps = ARRAY_SIZE(tcmu_mcgrps),
 479         .netnsok = true,
 480         .small_ops = tcmu_genl_ops,
 481         .n_small_ops = ARRAY_SIZE(tcmu_genl_ops),
 482 };
 483
 484 #define tcmu_cmd_set_dbi_cur(cmd, index) ((cmd)->dbi_cur = (index))
 485 #define tcmu_cmd_reset_dbi_cur(cmd) tcmu_cmd_set_dbi_cur(cmd, 0)
 486 #define tcmu_cmd_set_dbi(cmd, index) ((cmd)->dbi[(cmd)->dbi_cur++] = (index))
 487 #define tcmu_cmd_get_dbi(cmd) ((cmd)->dbi[(cmd)->dbi_cur++])
 488
 489 static void tcmu_cmd_free_data(struct tcmu_cmd *tcmu_cmd, uint32_t len)
 490 {
 491         struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
 492         uint32_t i;
 493
 494         for (i = 0; i < len; i++)
 495                 clear_bit(tcmu_cmd->dbi[i], udev->data_bitmap);
 496 }
 497
 498 static inline int tcmu_get_empty_block(struct tcmu_dev *udev,
 499                                        struct tcmu_cmd *tcmu_cmd,
 500                                        int prev_dbi, int *iov_cnt)
 501 {
 502         struct page *page;
 503         int ret, dbi;
 504
 505         dbi = find_first_zero_bit(udev->data_bitmap, udev->dbi_thresh);
 506         if (dbi == udev->dbi_thresh)
 507                 return -1;
 508
 509         page = radix_tree_lookup(&udev->data_blocks, dbi);
 510         if (!page) {
 511                 if (atomic_add_return(1, &global_db_count) >
 512                                       tcmu_global_max_blocks)
 513                         schedule_delayed_work(&tcmu_unmap_work, 0);
 514
 515                 /* try to get new page from the mm */
 516                 page = alloc_page(GFP_NOIO);
 517                 if (!page)
 518                         goto err_alloc;
 519
 520                 ret = radix_tree_insert(&udev->data_blocks, dbi, page);
 521                 if (ret)
 522                         goto err_insert;
 523         }
 524
 525         if (dbi > udev->dbi_max)
 526                 udev->dbi_max = dbi;
 527
 528         set_bit(dbi, udev->data_bitmap);
 529         tcmu_cmd_set_dbi(tcmu_cmd, dbi);
 530
 531         if (dbi != prev_dbi + 1)
 532                 *iov_cnt += 1;
 533
 534         return dbi;
 535 err_insert:
 536         __free_page(page);
 537 err_alloc:
 538         atomic_dec(&global_db_count);
 539         return -1;
 540 }
 541
 542 static int tcmu_get_empty_blocks(struct tcmu_dev *udev,
 543                                  struct tcmu_cmd *tcmu_cmd, int dbi_cnt)
 544 {
 545         /* start value of dbi + 1 must not be a valid dbi */
 546         int dbi = -2;
 547         int i, iov_cnt = 0;
 548
 549         for (i = 0; i < dbi_cnt; i++) {
 550                 dbi = tcmu_get_empty_block(udev, tcmu_cmd, dbi, &iov_cnt);
 551                 if (dbi < 0)
 552                         return -1;
 553         }
 554         return iov_cnt;
 555 }
 556
 557 static inline struct page *
 558 tcmu_get_block_page(struct tcmu_dev *udev, uint32_t dbi)
 559 {
 560         return radix_tree_lookup(&udev->data_blocks, dbi);
 561 }
 562
 563 static inline void tcmu_free_cmd(struct tcmu_cmd *tcmu_cmd)
 564 {
 565         if (tcmu_cmd->se_cmd)
 566                 tcmu_cmd->se_cmd->priv = NULL;
 567         kfree(tcmu_cmd->dbi);
 568         kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
 569 }
 570
 571 static inline void tcmu_cmd_set_block_cnts(struct tcmu_cmd *cmd)
 572 {
 573         int i, len;
 574         struct se_cmd *se_cmd = cmd->se_cmd;
 575
 576         cmd->dbi_cnt = DIV_ROUND_UP(se_cmd->data_length, DATA_BLOCK_SIZE);
 577
 578         if (se_cmd->se_cmd_flags & SCF_BIDI) {
 579                 BUG_ON(!(se_cmd->t_bidi_data_sg && se_cmd->t_bidi_data_nents));
 580                 for (i = 0, len = 0; i < se_cmd->t_bidi_data_nents; i++)
 581                         len += se_cmd->t_bidi_data_sg[i].length;
 582                 cmd->dbi_bidi_cnt = DIV_ROUND_UP(len, DATA_BLOCK_SIZE);
 583                 cmd->dbi_cnt += cmd->dbi_bidi_cnt;
 584                 cmd->data_len_bidi = len;
 585         }
 586 }
 587
 588 static int new_block_to_iov(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
 589                             struct iovec **iov, int prev_dbi, int len)
 590 {
 591         /* Get the next dbi */
 592         int dbi = tcmu_cmd_get_dbi(cmd);
 593
 594         /* Do not add more than DATA_BLOCK_SIZE to iov */
 595         if (len > DATA_BLOCK_SIZE)
 596                 len = DATA_BLOCK_SIZE;
 597
 598         /*
 599          * The following code will gather and map the blocks to the same iovec
 600          * when the blocks are all next to each other.
 601          */
 602         if (dbi != prev_dbi + 1) {
 603                 /* dbi is not next to previous dbi, so start new iov */
 604                 if (prev_dbi >= 0)
 605                         (*iov)++;
 606                 /* write offset relative to mb_addr */
 607                 (*iov)->iov_base = (void __user *)
 608                                 (udev->data_off + dbi * DATA_BLOCK_SIZE);
 609         }
 610         (*iov)->iov_len += len;
 611
 612         return dbi;
 613 }
 614
 615 static void tcmu_setup_iovs(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
 616                             struct iovec **iov, int data_length)
 617 {
 618         /* start value of dbi + 1 must not be a valid dbi */
 619         int dbi = -2;
 620
 621         /* We prepare the IOVs for DMA_FROM_DEVICE transfer direction */
 622         for (; data_length > 0; data_length -= DATA_BLOCK_SIZE)
 623                 dbi = new_block_to_iov(udev, cmd, iov, dbi, data_length);
 624 }
 625
 626 static struct tcmu_cmd *tcmu_alloc_cmd(struct se_cmd *se_cmd)
 627 {
 628         struct se_device *se_dev = se_cmd->se_dev;
 629         struct tcmu_dev *udev = TCMU_DEV(se_dev);
 630         struct tcmu_cmd *tcmu_cmd;
 631
 632         tcmu_cmd = kmem_cache_zalloc(tcmu_cmd_cache, GFP_NOIO);
 633         if (!tcmu_cmd)
 634                 return NULL;
 635
 636         INIT_LIST_HEAD(&tcmu_cmd->queue_entry);
 637         tcmu_cmd->se_cmd = se_cmd;
 638         tcmu_cmd->tcmu_dev = udev;
 639
 640         tcmu_cmd_set_block_cnts(tcmu_cmd);
 641         tcmu_cmd->dbi = kcalloc(tcmu_cmd->dbi_cnt, sizeof(uint32_t),
 642                                 GFP_NOIO);
 643         if (!tcmu_cmd->dbi) {
 644                 kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
 645                 return NULL;
 646         }
 647
 648         return tcmu_cmd;
 649 }
 650
 651 static inline void tcmu_flush_dcache_range(void *vaddr, size_t size)
 652 {
 653         unsigned long offset = offset_in_page(vaddr);
 654         void *start = vaddr - offset;
 655
 656         size = round_up(size+offset, PAGE_SIZE);
 657
 658         while (size) {
 659                 flush_dcache_page(vmalloc_to_page(start));
 660                 start += PAGE_SIZE;
 661                 size -= PAGE_SIZE;
 662         }
 663 }
 664
 665 /*
 666  * Some ring helper functions. We don't assume size is a power of 2 so
 667  * we can't use circ_buf.h.
 668  */
 669 static inline size_t spc_used(size_t head, size_t tail, size_t size)
 670 {
 671         int diff = head - tail;
 672
 673         if (diff >= 0)
 674                 return diff;
 675         else
 676                 return size + diff;
 677 }
 678
 679 static inline size_t spc_free(size_t head, size_t tail, size_t size)
 680 {
 681         /* Keep 1 byte unused or we can't tell full from empty */
 682         return (size - spc_used(head, tail, size) - 1);
 683 }
 684
 685 static inline size_t head_to_end(size_t head, size_t size)
 686 {
 687         return size - head;
 688 }
 689
 690 #define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size)
 691
 692 #define TCMU_SG_TO_DATA_AREA 1
 693 #define TCMU_DATA_AREA_TO_SG 2
 694
 695 static inline void tcmu_copy_data(struct tcmu_dev *udev,
 696                                   struct tcmu_cmd *tcmu_cmd, uint32_t direction,
 697                                   struct scatterlist *sg, unsigned int sg_nents,
 698                                   struct iovec **iov, size_t data_len)
 699 {
 700         /* start value of dbi + 1 must not be a valid dbi */
 701         int dbi = -2;
 702         size_t block_remaining, cp_len;
 703         struct sg_mapping_iter sg_iter;
 704         unsigned int sg_flags;
 705         struct page *page;
 706         void *data_page_start, *data_addr;
 707
 708         if (direction == TCMU_SG_TO_DATA_AREA)
 709                 sg_flags = SG_MITER_ATOMIC | SG_MITER_FROM_SG;
 710         else
 711                 sg_flags = SG_MITER_ATOMIC | SG_MITER_TO_SG;
 712         sg_miter_start(&sg_iter, sg, sg_nents, sg_flags);
 713
 714         while (data_len) {
 715                 if (direction == TCMU_SG_TO_DATA_AREA)
 716                         dbi = new_block_to_iov(udev, tcmu_cmd, iov, dbi,
 717                                                data_len);
 718                 else
 719                         dbi = tcmu_cmd_get_dbi(tcmu_cmd);
 720                 page = tcmu_get_block_page(udev, dbi);
 721                 if (direction == TCMU_DATA_AREA_TO_SG)
 722                         flush_dcache_page(page);
 723                 data_page_start = kmap_atomic(page);
 724                 block_remaining = DATA_BLOCK_SIZE;
 725
 726                 while (block_remaining && data_len) {
 727                         if (!sg_miter_next(&sg_iter)) {
 728                                 /* set length to 0 to abort outer loop */
 729                                 data_len = 0;
 730                                 pr_debug("tcmu_move_data: aborting data copy due to exhausted sg_list\n");
 731                                 break;
 732                         }
 733                         cp_len = min3(sg_iter.length, block_remaining, data_len);
 734
 735                         data_addr = data_page_start +
 736                                     DATA_BLOCK_SIZE - block_remaining;
 737                         if (direction == TCMU_SG_TO_DATA_AREA)
 738                                 memcpy(data_addr, sg_iter.addr, cp_len);
 739                         else
 740                                 memcpy(sg_iter.addr, data_addr, cp_len);
 741
 742                         data_len -= cp_len;
 743                         block_remaining -= cp_len;
 744                         sg_iter.consumed = cp_len;
 745                 }
 746                 sg_miter_stop(&sg_iter);
 747
 748                 kunmap_atomic(data_page_start);
 749                 if (direction == TCMU_SG_TO_DATA_AREA)
 750                         flush_dcache_page(page);
 751         }
 752 }
 753
 754 static void scatter_data_area(struct tcmu_dev *udev, struct tcmu_cmd *tcmu_cmd,
 755                               struct iovec **iov)
 756 {
 757         struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
 758
 759         tcmu_copy_data(udev, tcmu_cmd, TCMU_SG_TO_DATA_AREA, se_cmd->t_data_sg,
 760                        se_cmd->t_data_nents, iov, se_cmd->data_length);
 761 }
 762
 763 static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *tcmu_cmd,
 764                              bool bidi, uint32_t read_len)
 765 {
 766         struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
 767         struct scatterlist *data_sg;
 768         unsigned int data_nents;
 769
 770         if (!bidi) {
 771                 data_sg = se_cmd->t_data_sg;
 772                 data_nents = se_cmd->t_data_nents;
 773         } else {
 774                 /*
 775                  * For bidi case, the first count blocks are for Data-Out
 776                  * buffer blocks, and before gathering the Data-In buffer
 777                  * the Data-Out buffer blocks should be skipped.
 778                  */
 779                 tcmu_cmd_set_dbi_cur(tcmu_cmd,
 780                                      tcmu_cmd->dbi_cnt - tcmu_cmd->dbi_bidi_cnt);
 781
 782                 data_sg = se_cmd->t_bidi_data_sg;
 783                 data_nents = se_cmd->t_bidi_data_nents;
 784         }
 785
 786         tcmu_copy_data(udev, tcmu_cmd, TCMU_DATA_AREA_TO_SG, data_sg,
 787                        data_nents, NULL, read_len);
 788 }
 789
 790 static inline size_t spc_bitmap_free(unsigned long *bitmap, uint32_t thresh)
 791 {
 792         return thresh - bitmap_weight(bitmap, thresh);
 793 }
 794
 795 /*
 796  * We can't queue a command until we have space available on the cmd ring.
 797  *
 798  * Called with ring lock held.
 799  */
 800 static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size)
 801 {
 802         struct tcmu_mailbox *mb = udev->mb_addr;
 803         size_t space, cmd_needed;
 804         u32 cmd_head;
 805
 806         tcmu_flush_dcache_range(mb, sizeof(*mb));
 807
 808         cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
 809
 810         /*
 811          * If cmd end-of-ring space is too small then we need space for a NOP plus
 812          * original cmd - cmds are internally contiguous.
 813          */
 814         if (head_to_end(cmd_head, udev->cmdr_size) >= cmd_size)
 815                 cmd_needed = cmd_size;
 816         else
 817                 cmd_needed = cmd_size + head_to_end(cmd_head, udev->cmdr_size);
 818
 819         space = spc_free(cmd_head, udev->cmdr_last_cleaned, udev->cmdr_size);
 820         if (space < cmd_needed) {
 821                 pr_debug("no cmd space: %u %u %u\n", cmd_head,
 822                        udev->cmdr_last_cleaned, udev->cmdr_size);
 823                 return false;
 824         }
 825         return true;
 826 }
 827
 828 /*
 829  * We have to allocate data buffers before we can queue a command.
 830  * Returns -1 on error (not enough space) or number of needed iovs on success
 831  *
 832  * Called with ring lock held.
 833  */
 834 static int tcmu_alloc_data_space(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
 835                                   int *iov_bidi_cnt)
 836 {
 837         int space, iov_cnt = 0, ret = 0;
 838
 839         if (!cmd->dbi_cnt)
 840                 goto wr_iov_cnts;
 841
 842         /* try to check and get the data blocks as needed */
 843         space = spc_bitmap_free(udev->data_bitmap, udev->dbi_thresh);
 844         if (space < cmd->dbi_cnt) {
 845                 unsigned long blocks_left =
 846                                 (udev->max_blocks - udev->dbi_thresh) + space;
 847
 848                 if (blocks_left < cmd->dbi_cnt) {
 849                         pr_debug("no data space: only %lu available, but ask for %lu\n",
 850                                         blocks_left * DATA_BLOCK_SIZE,
 851                                         cmd->dbi_cnt * DATA_BLOCK_SIZE);
 852                         return -1;
 853                 }
 854
 855                 udev->dbi_thresh += cmd->dbi_cnt;
 856                 if (udev->dbi_thresh > udev->max_blocks)
 857                         udev->dbi_thresh = udev->max_blocks;
 858         }
 859
 860         iov_cnt = tcmu_get_empty_blocks(udev, cmd,
 861                                         cmd->dbi_cnt - cmd->dbi_bidi_cnt);
 862         if (iov_cnt < 0)
 863                 return -1;
 864
 865         if (cmd->dbi_bidi_cnt) {
 866                 ret = tcmu_get_empty_blocks(udev, cmd, cmd->dbi_bidi_cnt);
 867                 if (ret < 0)
 868                         return -1;
 869         }
 870 wr_iov_cnts:
 871         *iov_bidi_cnt = ret;
 872         return iov_cnt + ret;
 873 }
 874
 875 static inline size_t tcmu_cmd_get_base_cmd_size(size_t iov_cnt)
 876 {
 877         return max(offsetof(struct tcmu_cmd_entry, req.iov[iov_cnt]),
 878                         sizeof(struct tcmu_cmd_entry));
 879 }
 880
 881 static inline size_t tcmu_cmd_get_cmd_size(struct tcmu_cmd *tcmu_cmd,
 882                                            size_t base_command_size)
 883 {
 884         struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
 885         size_t command_size;
 886
 887         command_size = base_command_size +
 888                 round_up(scsi_command_size(se_cmd->t_task_cdb),
 889                                 TCMU_OP_ALIGN_SIZE);
 890
 891         WARN_ON(command_size & (TCMU_OP_ALIGN_SIZE-1));
 892
 893         return command_size;
 894 }
 895
 896 static void tcmu_setup_cmd_timer(struct tcmu_cmd *tcmu_cmd, unsigned int tmo,
 897                                  struct timer_list *timer)
 898 {
 899         if (!tmo)
 900                 return;
 901
 902         tcmu_cmd->deadline = round_jiffies_up(jiffies + msecs_to_jiffies(tmo));
 903         if (!timer_pending(timer))
 904                 mod_timer(timer, tcmu_cmd->deadline);
 905
 906         pr_debug("Timeout set up for cmd %p, dev = %s, tmo = %lu\n", tcmu_cmd,
 907                  tcmu_cmd->tcmu_dev->name, tmo / MSEC_PER_SEC);
 908 }
 909
 910 static int add_to_qfull_queue(struct tcmu_cmd *tcmu_cmd)
 911 {
 912         struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
 913         unsigned int tmo;
 914
 915         /*
 916          * For backwards compat if qfull_time_out is not set use
 917          * cmd_time_out and if that's not set use the default time out.
 918          */
 919         if (!udev->qfull_time_out)
 920                 return -ETIMEDOUT;
 921         else if (udev->qfull_time_out > 0)
 922                 tmo = udev->qfull_time_out;
 923         else if (udev->cmd_time_out)
 924                 tmo = udev->cmd_time_out;
 925         else
 926                 tmo = TCMU_TIME_OUT;
 927
 928         tcmu_setup_cmd_timer(tcmu_cmd, tmo, &udev->qfull_timer);
 929
 930         list_add_tail(&tcmu_cmd->queue_entry, &udev->qfull_queue);
 931         pr_debug("adding cmd %p on dev %s to ring space wait queue\n",
 932                  tcmu_cmd, udev->name);
 933         return 0;
 934 }
 935
 936 static uint32_t ring_insert_padding(struct tcmu_dev *udev, size_t cmd_size)
 937 {
 938         struct tcmu_cmd_entry_hdr *hdr;
 939         struct tcmu_mailbox *mb = udev->mb_addr;
 940         uint32_t cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
 941
 942         /* Insert a PAD if end-of-ring space is too small */
 943         if (head_to_end(cmd_head, udev->cmdr_size) < cmd_size) {
 944                 size_t pad_size = head_to_end(cmd_head, udev->cmdr_size);
 945
 946                 hdr = (void *) mb + CMDR_OFF + cmd_head;
 947                 tcmu_hdr_set_op(&hdr->len_op, TCMU_OP_PAD);
 948                 tcmu_hdr_set_len(&hdr->len_op, pad_size);
 949                 hdr->cmd_id = 0; /* not used for PAD */
 950                 hdr->kflags = 0;
 951                 hdr->uflags = 0;
 952                 tcmu_flush_dcache_range(hdr, sizeof(*hdr));
 953
 954                 UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size);
 955                 tcmu_flush_dcache_range(mb, sizeof(*mb));
 956
 957                 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
 958                 WARN_ON(cmd_head != 0);
 959         }
 960
 961         return cmd_head;
 962 }
 963
 964 /**
 965  * queue_cmd_ring - queue cmd to ring or internally
 966  * @tcmu_cmd: cmd to queue
 967  * @scsi_err: TCM error code if failure (-1) returned.
 968  *
 969  * Returns:
 970  * -1 we cannot queue internally or to the ring.
 971  *  0 success
 972  *  1 internally queued to wait for ring memory to free.
 973  */
 974 static int queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, sense_reason_t *scsi_err)
 975 {
 976         struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
 977         struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
 978         size_t base_command_size, command_size;
 979         struct tcmu_mailbox *mb = udev->mb_addr;
 980         struct tcmu_cmd_entry *entry;
 981         struct iovec *iov;
 982         int iov_cnt, iov_bidi_cnt, cmd_id;
 983         uint32_t cmd_head;
 984         uint64_t cdb_off;
 985         /* size of data buffer needed */
 986         size_t data_length = (size_t)tcmu_cmd->dbi_cnt * DATA_BLOCK_SIZE;
 987
 988         *scsi_err = TCM_NO_SENSE;
 989
 990         if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags)) {
 991                 *scsi_err = TCM_LUN_BUSY;
 992                 return -1;
 993         }
 994
 995         if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
 996                 *scsi_err = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 997                 return -1;
 998         }
 999
1000         if (!list_empty(&udev->qfull_queue))
1001                 goto queue;
1002
1003         if (data_length > udev->data_size) {
1004                 pr_warn("TCMU: Request of size %zu is too big for %zu data area\n",
1005                         data_length, udev->data_size);
1006                 *scsi_err = TCM_INVALID_CDB_FIELD;
1007                 return -1;
1008         }
1009
1010         iov_cnt = tcmu_alloc_data_space(udev, tcmu_cmd, &iov_bidi_cnt);
1011         if (iov_cnt < 0)
1012                 goto free_and_queue;
1013
1014         /*
1015          * Must be a certain minimum size for response sense info, but
1016          * also may be larger if the iov array is large.
1017          */
1018         base_command_size = tcmu_cmd_get_base_cmd_size(iov_cnt);
1019         command_size = tcmu_cmd_get_cmd_size(tcmu_cmd, base_command_size);
1020
1021         if (command_size > (udev->cmdr_size / 2)) {
1022                 pr_warn("TCMU: Request of size %zu is too big for %u cmd ring\n",
1023                         command_size, udev->cmdr_size);
1024                 tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cur);
1025                 *scsi_err = TCM_INVALID_CDB_FIELD;
1026                 return -1;
1027         }
1028
1029         if (!is_ring_space_avail(udev, command_size))
1030                 /*
1031                  * Don't leave commands partially setup because the unmap
1032                  * thread might need the blocks to make forward progress.
1033                  */
1034                 goto free_and_queue;
1035
1036         cmd_id = idr_alloc(&udev->commands, tcmu_cmd, 1, USHRT_MAX, GFP_NOWAIT);
1037         if (cmd_id < 0) {
1038                 pr_err("tcmu: Could not allocate cmd id.\n");
1039
1040                 tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cnt);
1041                 *scsi_err = TCM_OUT_OF_RESOURCES;
1042                 return -1;
1043         }
1044         tcmu_cmd->cmd_id = cmd_id;
1045
1046         pr_debug("allocated cmd id %u for cmd %p dev %s\n", tcmu_cmd->cmd_id,
1047                  tcmu_cmd, udev->name);
1048
1049         cmd_head = ring_insert_padding(udev, command_size);
1050
1051         entry = (void *) mb + CMDR_OFF + cmd_head;
1052         memset(entry, 0, command_size);
1053         tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_CMD);
1054
1055         /* prepare iov list and copy data to data area if necessary */
1056         tcmu_cmd_reset_dbi_cur(tcmu_cmd);
1057         iov = &entry->req.iov[0];
1058
1059         if (se_cmd->data_direction == DMA_TO_DEVICE ||
1060             se_cmd->se_cmd_flags & SCF_BIDI)
1061                 scatter_data_area(udev, tcmu_cmd, &iov);
1062         else
1063                 tcmu_setup_iovs(udev, tcmu_cmd, &iov, se_cmd->data_length);
1064
1065         entry->req.iov_cnt = iov_cnt - iov_bidi_cnt;
1066
1067         /* Handle BIDI commands */
1068         if (se_cmd->se_cmd_flags & SCF_BIDI) {
1069                 iov++;
1070                 tcmu_setup_iovs(udev, tcmu_cmd, &iov, tcmu_cmd->data_len_bidi);
1071                 entry->req.iov_bidi_cnt = iov_bidi_cnt;
1072         }
1073
1074         tcmu_setup_cmd_timer(tcmu_cmd, udev->cmd_time_out, &udev->cmd_timer);
1075
1076         entry->hdr.cmd_id = tcmu_cmd->cmd_id;
1077
1078         tcmu_hdr_set_len(&entry->hdr.len_op, command_size);
1079
1080         /* All offsets relative to mb_addr, not start of entry! */
1081         cdb_off = CMDR_OFF + cmd_head + base_command_size;
1082         memcpy((void *) mb + cdb_off, se_cmd->t_task_cdb, scsi_command_size(se_cmd->t_task_cdb));
1083         entry->req.cdb_off = cdb_off;
1084         tcmu_flush_dcache_range(entry, command_size);
1085
1086         UPDATE_HEAD(mb->cmd_head, command_size, udev->cmdr_size);
1087         tcmu_flush_dcache_range(mb, sizeof(*mb));
1088
1089         list_add_tail(&tcmu_cmd->queue_entry, &udev->inflight_queue);
1090
1091         /* TODO: only if FLUSH and FUA? */
1092         uio_event_notify(&udev->uio_info);
1093
1094         return 0;
1095
1096 free_and_queue:
1097         tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cur);
1098         tcmu_cmd_reset_dbi_cur(tcmu_cmd);
1099
1100 queue:
1101         if (add_to_qfull_queue(tcmu_cmd)) {
1102                 *scsi_err = TCM_OUT_OF_RESOURCES;
1103                 return -1;
1104         }
1105
1106         return 1;
1107 }
1108
1109 /**
1110  * queue_tmr_ring - queue tmr info to ring or internally
1111  * @udev: related tcmu_dev
1112  * @tmr: tcmu_tmr containing tmr info to queue
1113  *
1114  * Returns:
1115  *  0 success
1116  *  1 internally queued to wait for ring memory to free.
1117  */
1118 static int
1119 queue_tmr_ring(struct tcmu_dev *udev, struct tcmu_tmr *tmr)
1120 {
1121         struct tcmu_tmr_entry *entry;
1122         int cmd_size;
1123         int id_list_sz;
1124         struct tcmu_mailbox *mb = udev->mb_addr;
1125         uint32_t cmd_head;
1126
1127         if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags))
1128                 goto out_free;
1129
1130         id_list_sz = sizeof(tmr->tmr_cmd_ids[0]) * tmr->tmr_cmd_cnt;
1131         cmd_size = round_up(sizeof(*entry) + id_list_sz, TCMU_OP_ALIGN_SIZE);
1132
1133         if (!list_empty(&udev->tmr_queue) ||
1134             !is_ring_space_avail(udev, cmd_size)) {
1135                 list_add_tail(&tmr->queue_entry, &udev->tmr_queue);
1136                 pr_debug("adding tmr %p on dev %s to TMR ring space wait queue\n",
1137                          tmr, udev->name);
1138                 return 1;
1139         }
1140
1141         cmd_head = ring_insert_padding(udev, cmd_size);
1142
1143         entry = (void *)mb + CMDR_OFF + cmd_head;
1144         memset(entry, 0, cmd_size);
1145         tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_TMR);
1146         tcmu_hdr_set_len(&entry->hdr.len_op, cmd_size);
1147         entry->tmr_type = tmr->tmr_type;
1148         entry->cmd_cnt = tmr->tmr_cmd_cnt;
1149         memcpy(&entry->cmd_ids[0], &tmr->tmr_cmd_ids[0], id_list_sz);
1150         tcmu_flush_dcache_range(entry, cmd_size);
1151
1152         UPDATE_HEAD(mb->cmd_head, cmd_size, udev->cmdr_size);
1153         tcmu_flush_dcache_range(mb, sizeof(*mb));
1154
1155         uio_event_notify(&udev->uio_info);
1156
1157 out_free:
1158         kfree(tmr);
1159
1160         return 0;
1161 }
1162
1163 static sense_reason_t
1164 tcmu_queue_cmd(struct se_cmd *se_cmd)
1165 {
1166         struct se_device *se_dev = se_cmd->se_dev;
1167         struct tcmu_dev *udev = TCMU_DEV(se_dev);
1168         struct tcmu_cmd *tcmu_cmd;
1169         sense_reason_t scsi_ret = TCM_CHECK_CONDITION_ABORT_CMD;
1170         int ret = -1;
1171
1172         tcmu_cmd = tcmu_alloc_cmd(se_cmd);
1173         if (!tcmu_cmd)
1174                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1175
1176         mutex_lock(&udev->cmdr_lock);
1177         se_cmd->priv = tcmu_cmd;
1178         if (!(se_cmd->transport_state & CMD_T_ABORTED))
1179                 ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
1180         if (ret < 0)
1181                 tcmu_free_cmd(tcmu_cmd);
1182         mutex_unlock(&udev->cmdr_lock);
1183         return scsi_ret;
1184 }
1185
1186 static void tcmu_set_next_deadline(struct list_head *queue,
1187                                    struct timer_list *timer)
1188 {
1189         struct tcmu_cmd *cmd;
1190
1191         if (!list_empty(queue)) {
1192                 cmd = list_first_entry(queue, struct tcmu_cmd, queue_entry);
1193                 mod_timer(timer, cmd->deadline);
1194         } else
1195                 del_timer(timer);
1196 }
1197
1198 static int
1199 tcmu_tmr_type(enum tcm_tmreq_table tmf)
1200 {
1201         switch (tmf) {
1202         case TMR_ABORT_TASK:            return TCMU_TMR_ABORT_TASK;
1203         case TMR_ABORT_TASK_SET:        return TCMU_TMR_ABORT_TASK_SET;
1204         case TMR_CLEAR_ACA:             return TCMU_TMR_CLEAR_ACA;
1205         case TMR_CLEAR_TASK_SET:        return TCMU_TMR_CLEAR_TASK_SET;
1206         case TMR_LUN_RESET:             return TCMU_TMR_LUN_RESET;
1207         case TMR_TARGET_WARM_RESET:     return TCMU_TMR_TARGET_WARM_RESET;
1208         case TMR_TARGET_COLD_RESET:     return TCMU_TMR_TARGET_COLD_RESET;
1209         case TMR_LUN_RESET_PRO:         return TCMU_TMR_LUN_RESET_PRO;
1210         default:                        return TCMU_TMR_UNKNOWN;
1211         }
1212 }
1213
1214 static void
1215 tcmu_tmr_notify(struct se_device *se_dev, enum tcm_tmreq_table tmf,
1216                 struct list_head *cmd_list)
1217 {
1218         int i = 0, cmd_cnt = 0;
1219         bool unqueued = false;
1220         uint16_t *cmd_ids = NULL;
1221         struct tcmu_cmd *cmd;
1222         struct se_cmd *se_cmd;
1223         struct tcmu_tmr *tmr;
1224         struct tcmu_dev *udev = TCMU_DEV(se_dev);
1225
1226         mutex_lock(&udev->cmdr_lock);
1227
1228         /* First we check for aborted commands in qfull_queue */
1229         list_for_each_entry(se_cmd, cmd_list, state_list) {
1230                 i++;
1231                 if (!se_cmd->priv)
1232                         continue;
1233                 cmd = se_cmd->priv;
1234                 /* Commands on qfull queue have no id yet */
1235                 if (cmd->cmd_id) {
1236                         cmd_cnt++;
1237                         continue;
1238                 }
1239                 pr_debug("Removing aborted command %p from queue on dev %s.\n",
1240                          cmd, udev->name);
1241
1242                 list_del_init(&cmd->queue_entry);
1243                 tcmu_free_cmd(cmd);
1244                 target_complete_cmd(se_cmd, SAM_STAT_TASK_ABORTED);
1245                 unqueued = true;
1246         }
1247         if (unqueued)
1248                 tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
1249
1250         if (!test_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags))
1251                 goto unlock;
1252
1253         pr_debug("TMR event %d on dev %s, aborted cmds %d, afflicted cmd_ids %d\n",
1254                  tcmu_tmr_type(tmf), udev->name, i, cmd_cnt);
1255
1256         tmr = kmalloc(sizeof(*tmr) + cmd_cnt * sizeof(*cmd_ids), GFP_KERNEL);
1257         if (!tmr)
1258                 goto unlock;
1259
1260         tmr->tmr_type = tcmu_tmr_type(tmf);
1261         tmr->tmr_cmd_cnt = cmd_cnt;
1262
1263         if (cmd_cnt != 0) {
1264                 cmd_cnt = 0;
1265                 list_for_each_entry(se_cmd, cmd_list, state_list) {
1266                         if (!se_cmd->priv)
1267                                 continue;
1268                         cmd = se_cmd->priv;
1269                         if (cmd->cmd_id)
1270                                 tmr->tmr_cmd_ids[cmd_cnt++] = cmd->cmd_id;
1271                 }
1272         }
1273
1274         queue_tmr_ring(udev, tmr);
1275
1276 unlock:
1277         mutex_unlock(&udev->cmdr_lock);
1278 }
1279
1280 static void tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry *entry)
1281 {
1282         struct se_cmd *se_cmd = cmd->se_cmd;
1283         struct tcmu_dev *udev = cmd->tcmu_dev;
1284         bool read_len_valid = false;
1285         uint32_t read_len;
1286
1287         /*
1288          * cmd has been completed already from timeout, just reclaim
1289          * data area space and free cmd
1290          */
1291         if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
1292                 WARN_ON_ONCE(se_cmd);
1293                 goto out;
1294         }
1295
1296         list_del_init(&cmd->queue_entry);
1297
1298         tcmu_cmd_reset_dbi_cur(cmd);
1299
1300         if (entry->hdr.uflags & TCMU_UFLAG_UNKNOWN_OP) {
1301                 pr_warn("TCMU: Userspace set UNKNOWN_OP flag on se_cmd %p\n",
1302                         cmd->se_cmd);
1303                 entry->rsp.scsi_status = SAM_STAT_CHECK_CONDITION;
1304                 goto done;
1305         }
1306
1307         read_len = se_cmd->data_length;
1308         if (se_cmd->data_direction == DMA_FROM_DEVICE &&
1309             (entry->hdr.uflags & TCMU_UFLAG_READ_LEN) && entry->rsp.read_len) {
1310                 read_len_valid = true;
1311                 if (entry->rsp.read_len < read_len)
1312                         read_len = entry->rsp.read_len;
1313         }
1314
1315         if (entry->rsp.scsi_status == SAM_STAT_CHECK_CONDITION) {
1316                 transport_copy_sense_to_cmd(se_cmd, entry->rsp.sense_buffer);
1317                 if (!read_len_valid )
1318                         goto done;
1319                 else
1320                         se_cmd->se_cmd_flags |= SCF_TREAT_READ_AS_NORMAL;
1321         }
1322         if (se_cmd->se_cmd_flags & SCF_BIDI) {
1323                 /* Get Data-In buffer before clean up */
1324                 gather_data_area(udev, cmd, true, read_len);
1325         } else if (se_cmd->data_direction == DMA_FROM_DEVICE) {
1326                 gather_data_area(udev, cmd, false, read_len);
1327         } else if (se_cmd->data_direction == DMA_TO_DEVICE) {
1328                 /* TODO: */
1329         } else if (se_cmd->data_direction != DMA_NONE) {
1330                 pr_warn("TCMU: data direction was %d!\n",
1331                         se_cmd->data_direction);
1332         }
1333
1334 done:
1335         if (read_len_valid) {
1336                 pr_debug("read_len = %d\n", read_len);
1337                 target_complete_cmd_with_length(cmd->se_cmd,
1338                                         entry->rsp.scsi_status, read_len);
1339         } else
1340                 target_complete_cmd(cmd->se_cmd, entry->rsp.scsi_status);
1341
1342 out:
1343         tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
1344         tcmu_free_cmd(cmd);
1345 }
1346
1347 static int tcmu_run_tmr_queue(struct tcmu_dev *udev)
1348 {
1349         struct tcmu_tmr *tmr, *tmp;
1350         LIST_HEAD(tmrs);
1351
1352         if (list_empty(&udev->tmr_queue))
1353                 return 1;
1354
1355         pr_debug("running %s's tmr queue\n", udev->name);
1356
1357         list_splice_init(&udev->tmr_queue, &tmrs);
1358
1359         list_for_each_entry_safe(tmr, tmp, &tmrs, queue_entry) {
1360                 list_del_init(&tmr->queue_entry);
1361
1362                 pr_debug("removing tmr %p on dev %s from queue\n",
1363                          tmr, udev->name);
1364
1365                 if (queue_tmr_ring(udev, tmr)) {
1366                         pr_debug("ran out of space during tmr queue run\n");
1367                         /*
1368                          * tmr was requeued, so just put all tmrs back in
1369                          * the queue
1370                          */
1371                         list_splice_tail(&tmrs, &udev->tmr_queue);
1372                         return 0;
1373                 }
1374         }
1375
1376         return 1;
1377 }
1378
1379 static unsigned int tcmu_handle_completions(struct tcmu_dev *udev)
1380 {
1381         struct tcmu_mailbox *mb;
1382         struct tcmu_cmd *cmd;
1383         bool free_space = false;
1384
1385         if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
1386                 pr_err("ring broken, not handling completions\n");
1387                 return 0;
1388         }
1389
1390         mb = udev->mb_addr;
1391         tcmu_flush_dcache_range(mb, sizeof(*mb));
1392
1393         while (udev->cmdr_last_cleaned != READ_ONCE(mb->cmd_tail)) {
1394
1395                 struct tcmu_cmd_entry *entry = (void *) mb + CMDR_OFF + udev->cmdr_last_cleaned;
1396
1397                 /*
1398                  * Flush max. up to end of cmd ring since current entry might
1399                  * be a padding that is shorter than sizeof(*entry)
1400                  */
1401                 size_t ring_left = head_to_end(udev->cmdr_last_cleaned,
1402                                                udev->cmdr_size);
1403                 tcmu_flush_dcache_range(entry, ring_left < sizeof(*entry) ?
1404                                         ring_left : sizeof(*entry));
1405
1406                 free_space = true;
1407
1408                 if (tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_PAD ||
1409                     tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_TMR) {
1410                         UPDATE_HEAD(udev->cmdr_last_cleaned,
1411                                     tcmu_hdr_get_len(entry->hdr.len_op),
1412                                     udev->cmdr_size);
1413                         continue;
1414                 }
1415                 WARN_ON(tcmu_hdr_get_op(entry->hdr.len_op) != TCMU_OP_CMD);
1416
1417                 cmd = idr_remove(&udev->commands, entry->hdr.cmd_id);
1418                 if (!cmd) {
1419                         pr_err("cmd_id %u not found, ring is broken\n",
1420                                entry->hdr.cmd_id);
1421                         set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
1422                         break;
1423                 }
1424
1425                 tcmu_handle_completion(cmd, entry);
1426
1427                 UPDATE_HEAD(udev->cmdr_last_cleaned,
1428                             tcmu_hdr_get_len(entry->hdr.len_op),
1429                             udev->cmdr_size);
1430         }
1431         if (free_space)
1432                 free_space = tcmu_run_tmr_queue(udev);
1433
1434         if (atomic_read(&global_db_count) > tcmu_global_max_blocks &&
1435             idr_is_empty(&udev->commands) && list_empty(&udev->qfull_queue)) {
1436                 /*
1437                  * Allocated blocks exceeded global block limit, currently no
1438                  * more pending or waiting commands so try to reclaim blocks.
1439                  */
1440                 schedule_delayed_work(&tcmu_unmap_work, 0);
1441         }
1442         if (udev->cmd_time_out)
1443                 tcmu_set_next_deadline(&udev->inflight_queue, &udev->cmd_timer);
1444
1445         return free_space;
1446 }
1447
1448 static void tcmu_check_expired_ring_cmd(struct tcmu_cmd *cmd)
1449 {
1450         struct se_cmd *se_cmd;
1451
1452         if (!time_after_eq(jiffies, cmd->deadline))
1453                 return;
1454
1455         set_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags);
1456         list_del_init(&cmd->queue_entry);
1457         se_cmd = cmd->se_cmd;
1458         se_cmd->priv = NULL;
1459         cmd->se_cmd = NULL;
1460
1461         pr_debug("Timing out inflight cmd %u on dev %s.\n",
1462                  cmd->cmd_id, cmd->tcmu_dev->name);
1463
1464         target_complete_cmd(se_cmd, SAM_STAT_CHECK_CONDITION);
1465 }
1466
1467 static void tcmu_check_expired_queue_cmd(struct tcmu_cmd *cmd)
1468 {
1469         struct se_cmd *se_cmd;
1470
1471         if (!time_after_eq(jiffies, cmd->deadline))
1472                 return;
1473
1474         pr_debug("Timing out queued cmd %p on dev %s.\n",
1475                   cmd, cmd->tcmu_dev->name);
1476
1477         list_del_init(&cmd->queue_entry);
1478         se_cmd = cmd->se_cmd;
1479         tcmu_free_cmd(cmd);
1480
1481         target_complete_cmd(se_cmd, SAM_STAT_TASK_SET_FULL);
1482 }
1483
1484 static void tcmu_device_timedout(struct tcmu_dev *udev)
1485 {
1486         spin_lock(&timed_out_udevs_lock);
1487         if (list_empty(&udev->timedout_entry))
1488                 list_add_tail(&udev->timedout_entry, &timed_out_udevs);
1489         spin_unlock(&timed_out_udevs_lock);
1490
1491         schedule_delayed_work(&tcmu_unmap_work, 0);
1492 }
1493
1494 static void tcmu_cmd_timedout(struct timer_list *t)
1495 {
1496         struct tcmu_dev *udev = from_timer(udev, t, cmd_timer);
1497
1498         pr_debug("%s cmd timeout has expired\n", udev->name);
1499         tcmu_device_timedout(udev);
1500 }
1501
1502 static void tcmu_qfull_timedout(struct timer_list *t)
1503 {
1504         struct tcmu_dev *udev = from_timer(udev, t, qfull_timer);
1505
1506         pr_debug("%s qfull timeout has expired\n", udev->name);
1507         tcmu_device_timedout(udev);
1508 }
1509
1510 static int tcmu_attach_hba(struct se_hba *hba, u32 host_id)
1511 {
1512         struct tcmu_hba *tcmu_hba;
1513
1514         tcmu_hba = kzalloc(sizeof(struct tcmu_hba), GFP_KERNEL);
1515         if (!tcmu_hba)
1516                 return -ENOMEM;
1517
1518         tcmu_hba->host_id = host_id;
1519         hba->hba_ptr = tcmu_hba;
1520
1521         return 0;
1522 }
1523
1524 static void tcmu_detach_hba(struct se_hba *hba)
1525 {
1526         kfree(hba->hba_ptr);
1527         hba->hba_ptr = NULL;
1528 }
1529
1530 static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name)
1531 {
1532         struct tcmu_dev *udev;
1533
1534         udev = kzalloc(sizeof(struct tcmu_dev), GFP_KERNEL);
1535         if (!udev)
1536                 return NULL;
1537         kref_init(&udev->kref);
1538
1539         udev->name = kstrdup(name, GFP_KERNEL);
1540         if (!udev->name) {
1541                 kfree(udev);
1542                 return NULL;
1543         }
1544
1545         udev->hba = hba;
1546         udev->cmd_time_out = TCMU_TIME_OUT;
1547         udev->qfull_time_out = -1;
1548
1549         udev->max_blocks = DATA_BLOCK_BITS_DEF;
1550         mutex_init(&udev->cmdr_lock);
1551
1552         INIT_LIST_HEAD(&udev->node);
1553         INIT_LIST_HEAD(&udev->timedout_entry);
1554         INIT_LIST_HEAD(&udev->qfull_queue);
1555         INIT_LIST_HEAD(&udev->tmr_queue);
1556         INIT_LIST_HEAD(&udev->inflight_queue);
1557         idr_init(&udev->commands);
1558
1559         timer_setup(&udev->qfull_timer, tcmu_qfull_timedout, 0);
1560         timer_setup(&udev->cmd_timer, tcmu_cmd_timedout, 0);
1561
1562         INIT_RADIX_TREE(&udev->data_blocks, GFP_KERNEL);
1563
1564         return &udev->se_dev;
1565 }
1566
1567 static void run_qfull_queue(struct tcmu_dev *udev, bool fail)
1568 {
1569         struct tcmu_cmd *tcmu_cmd, *tmp_cmd;
1570         LIST_HEAD(cmds);
1571         sense_reason_t scsi_ret;
1572         int ret;
1573
1574         if (list_empty(&udev->qfull_queue))
1575                 return;
1576
1577         pr_debug("running %s's cmdr queue forcefail %d\n", udev->name, fail);
1578
1579         list_splice_init(&udev->qfull_queue, &cmds);
1580
1581         list_for_each_entry_safe(tcmu_cmd, tmp_cmd, &cmds, queue_entry) {
1582                 list_del_init(&tcmu_cmd->queue_entry);
1583
1584                 pr_debug("removing cmd %p on dev %s from queue\n",
1585                          tcmu_cmd, udev->name);
1586
1587                 if (fail) {
1588                         /*
1589                          * We were not able to even start the command, so
1590                          * fail with busy to allow a retry in case runner
1591                          * was only temporarily down. If the device is being
1592                          * removed then LIO core will do the right thing and
1593                          * fail the retry.
1594                          */
1595                         target_complete_cmd(tcmu_cmd->se_cmd, SAM_STAT_BUSY);
1596                         tcmu_free_cmd(tcmu_cmd);
1597                         continue;
1598                 }
1599
1600                 ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
1601                 if (ret < 0) {
1602                         pr_debug("cmd %p on dev %s failed with %u\n",
1603                                  tcmu_cmd, udev->name, scsi_ret);
1604                         /*
1605                          * Ignore scsi_ret for now. target_complete_cmd
1606                          * drops it.
1607                          */
1608                         target_complete_cmd(tcmu_cmd->se_cmd,
1609                                             SAM_STAT_CHECK_CONDITION);
1610                         tcmu_free_cmd(tcmu_cmd);
1611                 } else if (ret > 0) {
1612                         pr_debug("ran out of space during cmdr queue run\n");
1613                         /*
1614                          * cmd was requeued, so just put all cmds back in
1615                          * the queue
1616                          */
1617                         list_splice_tail(&cmds, &udev->qfull_queue);
1618                         break;
1619                 }
1620         }
1621
1622         tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
1623 }
1624
1625 static int tcmu_irqcontrol(struct uio_info *info, s32 irq_on)
1626 {
1627         struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1628
1629         mutex_lock(&udev->cmdr_lock);
1630         if (tcmu_handle_completions(udev))
1631                 run_qfull_queue(udev, false);
1632         mutex_unlock(&udev->cmdr_lock);
1633
1634         return 0;
1635 }
1636
1637 /*
1638  * mmap code from uio.c. Copied here because we want to hook mmap()
1639  * and this stuff must come along.
1640  */
1641 static int tcmu_find_mem_index(struct vm_area_struct *vma)
1642 {
1643         struct tcmu_dev *udev = vma->vm_private_data;
1644         struct uio_info *info = &udev->uio_info;
1645
1646         if (vma->vm_pgoff < MAX_UIO_MAPS) {
1647                 if (info->mem[vma->vm_pgoff].size == 0)
1648                         return -1;
1649                 return (int)vma->vm_pgoff;
1650         }
1651         return -1;
1652 }
1653
1654 static struct page *tcmu_try_get_block_page(struct tcmu_dev *udev, uint32_t dbi)
1655 {
1656         struct page *page;
1657
1658         mutex_lock(&udev->cmdr_lock);
1659         page = tcmu_get_block_page(udev, dbi);
1660         if (likely(page)) {
1661                 mutex_unlock(&udev->cmdr_lock);
1662                 return page;
1663         }
1664
1665         /*
1666          * Userspace messed up and passed in a address not in the
1667          * data iov passed to it.
1668          */
1669         pr_err("Invalid addr to data block mapping  (dbi %u) on device %s\n",
1670                dbi, udev->name);
1671         page = NULL;
1672         mutex_unlock(&udev->cmdr_lock);
1673
1674         return page;
1675 }
1676
1677 static vm_fault_t tcmu_vma_fault(struct vm_fault *vmf)
1678 {
1679         struct tcmu_dev *udev = vmf->vma->vm_private_data;
1680         struct uio_info *info = &udev->uio_info;
1681         struct page *page;
1682         unsigned long offset;
1683         void *addr;
1684
1685         int mi = tcmu_find_mem_index(vmf->vma);
1686         if (mi < 0)
1687                 return VM_FAULT_SIGBUS;
1688
1689         /*
1690          * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
1691          * to use mem[N].
1692          */
1693         offset = (vmf->pgoff - mi) << PAGE_SHIFT;
1694
1695         if (offset < udev->data_off) {
1696                 /* For the vmalloc()ed cmd area pages */
1697                 addr = (void *)(unsigned long)info->mem[mi].addr + offset;
1698                 page = vmalloc_to_page(addr);
1699         } else {
1700                 uint32_t dbi;
1701
1702                 /* For the dynamically growing data area pages */
1703                 dbi = (offset - udev->data_off) / DATA_BLOCK_SIZE;
1704                 page = tcmu_try_get_block_page(udev, dbi);
1705                 if (!page)
1706                         return VM_FAULT_SIGBUS;
1707         }
1708
1709         get_page(page);
1710         vmf->page = page;
1711         return 0;
1712 }
1713
1714 static const struct vm_operations_struct tcmu_vm_ops = {
1715         .fault = tcmu_vma_fault,
1716 };
1717
1718 static int tcmu_mmap(struct uio_info *info, struct vm_area_struct *vma)
1719 {
1720         struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1721
1722         vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
1723         vma->vm_ops = &tcmu_vm_ops;
1724
1725         vma->vm_private_data = udev;
1726
1727         /* Ensure the mmap is exactly the right size */
1728         if (vma_pages(vma) != (udev->ring_size >> PAGE_SHIFT))
1729                 return -EINVAL;
1730
1731         return 0;
1732 }
1733
1734 static int tcmu_open(struct uio_info *info, struct inode *inode)
1735 {
1736         struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1737
1738         /* O_EXCL not supported for char devs, so fake it? */
1739         if (test_and_set_bit(TCMU_DEV_BIT_OPEN, &udev->flags))
1740                 return -EBUSY;
1741
1742         udev->inode = inode;
1743         kref_get(&udev->kref);
1744
1745         pr_debug("open\n");
1746
1747         return 0;
1748 }
1749
1750 static void tcmu_dev_call_rcu(struct rcu_head *p)
1751 {
1752         struct se_device *dev = container_of(p, struct se_device, rcu_head);
1753         struct tcmu_dev *udev = TCMU_DEV(dev);
1754
1755         kfree(udev->uio_info.name);
1756         kfree(udev->name);
1757         kfree(udev);
1758 }
1759
1760 static int tcmu_check_and_free_pending_cmd(struct tcmu_cmd *cmd)
1761 {
1762         if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
1763                 kmem_cache_free(tcmu_cmd_cache, cmd);
1764                 return 0;
1765         }
1766         return -EINVAL;
1767 }
1768
1769 static void tcmu_blocks_release(struct radix_tree_root *blocks,
1770                                 int start, int end)
1771 {
1772         int i;
1773         struct page *page;
1774
1775         for (i = start; i < end; i++) {
1776                 page = radix_tree_delete(blocks, i);
1777                 if (page) {
1778                         __free_page(page);
1779                         atomic_dec(&global_db_count);
1780                 }
1781         }
1782 }
1783
1784 static void tcmu_remove_all_queued_tmr(struct tcmu_dev *udev)
1785 {
1786         struct tcmu_tmr *tmr, *tmp;
1787
1788         list_for_each_entry_safe(tmr, tmp, &udev->tmr_queue, queue_entry) {
1789                 list_del_init(&tmr->queue_entry);
1790                 kfree(tmr);
1791         }
1792 }
1793
1794 static void tcmu_dev_kref_release(struct kref *kref)
1795 {
1796         struct tcmu_dev *udev = container_of(kref, struct tcmu_dev, kref);
1797         struct se_device *dev = &udev->se_dev;
1798         struct tcmu_cmd *cmd;
1799         bool all_expired = true;
1800         int i;
1801
1802         vfree(udev->mb_addr);
1803         udev->mb_addr = NULL;
1804
1805         spin_lock_bh(&timed_out_udevs_lock);
1806         if (!list_empty(&udev->timedout_entry))
1807                 list_del(&udev->timedout_entry);
1808         spin_unlock_bh(&timed_out_udevs_lock);
1809
1810         /* Upper layer should drain all requests before calling this */
1811         mutex_lock(&udev->cmdr_lock);
1812         idr_for_each_entry(&udev->commands, cmd, i) {
1813                 if (tcmu_check_and_free_pending_cmd(cmd) != 0)
1814                         all_expired = false;
1815         }
1816         /* There can be left over TMR cmds. Remove them. */
1817         tcmu_remove_all_queued_tmr(udev);
1818         if (!list_empty(&udev->qfull_queue))
1819                 all_expired = false;
1820         idr_destroy(&udev->commands);
1821         WARN_ON(!all_expired);
1822
1823         tcmu_blocks_release(&udev->data_blocks, 0, udev->dbi_max + 1);
1824         bitmap_free(udev->data_bitmap);
1825         mutex_unlock(&udev->cmdr_lock);
1826
1827         call_rcu(&dev->rcu_head, tcmu_dev_call_rcu);
1828 }
1829
1830 static int tcmu_release(struct uio_info *info, struct inode *inode)
1831 {
1832         struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1833
1834         clear_bit(TCMU_DEV_BIT_OPEN, &udev->flags);
1835
1836         pr_debug("close\n");
1837         /* release ref from open */
1838         kref_put(&udev->kref, tcmu_dev_kref_release);
1839         return 0;
1840 }
1841
1842 static int tcmu_init_genl_cmd_reply(struct tcmu_dev *udev, int cmd)
1843 {
1844         struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
1845
1846         if (!tcmu_kern_cmd_reply_supported)
1847                 return 0;
1848
1849         if (udev->nl_reply_supported <= 0)
1850                 return 0;
1851
1852         mutex_lock(&tcmu_nl_cmd_mutex);
1853
1854         if (tcmu_netlink_blocked) {
1855                 mutex_unlock(&tcmu_nl_cmd_mutex);
1856                 pr_warn("Failing nl cmd %d on %s. Interface is blocked.\n", cmd,
1857                         udev->name);
1858                 return -EAGAIN;
1859         }
1860
1861         if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
1862                 mutex_unlock(&tcmu_nl_cmd_mutex);
1863                 pr_warn("netlink cmd %d already executing on %s\n",
1864                          nl_cmd->cmd, udev->name);
1865                 return -EBUSY;
1866         }
1867
1868         memset(nl_cmd, 0, sizeof(*nl_cmd));
1869         nl_cmd->cmd = cmd;
1870         nl_cmd->udev = udev;
1871         init_completion(&nl_cmd->complete);
1872         INIT_LIST_HEAD(&nl_cmd->nl_list);
1873
1874         list_add_tail(&nl_cmd->nl_list, &tcmu_nl_cmd_list);
1875
1876         mutex_unlock(&tcmu_nl_cmd_mutex);
1877         return 0;
1878 }
1879
1880 static void tcmu_destroy_genl_cmd_reply(struct tcmu_dev *udev)
1881 {
1882         struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
1883
1884         if (!tcmu_kern_cmd_reply_supported)
1885                 return;
1886
1887         if (udev->nl_reply_supported <= 0)
1888                 return;
1889
1890         mutex_lock(&tcmu_nl_cmd_mutex);
1891
1892         list_del(&nl_cmd->nl_list);
1893         memset(nl_cmd, 0, sizeof(*nl_cmd));
1894
1895         mutex_unlock(&tcmu_nl_cmd_mutex);
1896 }
1897
1898 static int tcmu_wait_genl_cmd_reply(struct tcmu_dev *udev)
1899 {
1900         struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
1901         int ret;
1902
1903         if (!tcmu_kern_cmd_reply_supported)
1904                 return 0;
1905
1906         if (udev->nl_reply_supported <= 0)
1907                 return 0;
1908
1909         pr_debug("sleeping for nl reply\n");
1910         wait_for_completion(&nl_cmd->complete);
1911
1912         mutex_lock(&tcmu_nl_cmd_mutex);
1913         nl_cmd->cmd = TCMU_CMD_UNSPEC;
1914         ret = nl_cmd->status;
1915         mutex_unlock(&tcmu_nl_cmd_mutex);
1916
1917         return ret;
1918 }
1919
1920 static int tcmu_netlink_event_init(struct tcmu_dev *udev,
1921                                    enum tcmu_genl_cmd cmd,
1922                                    struct sk_buff **buf, void **hdr)
1923 {
1924         struct sk_buff *skb;
1925         void *msg_header;
1926         int ret = -ENOMEM;
1927
1928         skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
1929         if (!skb)
1930                 return ret;
1931
1932         msg_header = genlmsg_put(skb, 0, 0, &tcmu_genl_family, 0, cmd);
1933         if (!msg_header)
1934                 goto free_skb;
1935
1936         ret = nla_put_string(skb, TCMU_ATTR_DEVICE, udev->uio_info.name);
1937         if (ret < 0)
1938                 goto free_skb;
1939
1940         ret = nla_put_u32(skb, TCMU_ATTR_MINOR, udev->uio_info.uio_dev->minor);
1941         if (ret < 0)
1942                 goto free_skb;
1943
1944         ret = nla_put_u32(skb, TCMU_ATTR_DEVICE_ID, udev->se_dev.dev_index);
1945         if (ret < 0)
1946                 goto free_skb;
1947
1948         *buf = skb;
1949         *hdr = msg_header;
1950         return ret;
1951
1952 free_skb:
1953         nlmsg_free(skb);
1954         return ret;
1955 }
1956
1957 static int tcmu_netlink_event_send(struct tcmu_dev *udev,
1958                                    enum tcmu_genl_cmd cmd,
1959                                    struct sk_buff *skb, void *msg_header)
1960 {
1961         int ret;
1962
1963         genlmsg_end(skb, msg_header);
1964
1965         ret = tcmu_init_genl_cmd_reply(udev, cmd);
1966         if (ret) {
1967                 nlmsg_free(skb);
1968                 return ret;
1969         }
1970
1971         ret = genlmsg_multicast_allns(&tcmu_genl_family, skb, 0,
1972                                       TCMU_MCGRP_CONFIG, GFP_KERNEL);
1973
1974         /* Wait during an add as the listener may not be up yet */
1975         if (ret == 0 ||
1976            (ret == -ESRCH && cmd == TCMU_CMD_ADDED_DEVICE))
1977                 return tcmu_wait_genl_cmd_reply(udev);
1978         else
1979                 tcmu_destroy_genl_cmd_reply(udev);
1980
1981         return ret;
1982 }
1983
1984 static int tcmu_send_dev_add_event(struct tcmu_dev *udev)
1985 {
1986         struct sk_buff *skb = NULL;
1987         void *msg_header = NULL;
1988         int ret = 0;
1989
1990         ret = tcmu_netlink_event_init(udev, TCMU_CMD_ADDED_DEVICE, &skb,
1991                                       &msg_header);
1992         if (ret < 0)
1993                 return ret;
1994         return tcmu_netlink_event_send(udev, TCMU_CMD_ADDED_DEVICE, skb,
1995                                        msg_header);
1996 }
1997
1998 static int tcmu_send_dev_remove_event(struct tcmu_dev *udev)
1999 {
2000         struct sk_buff *skb = NULL;
2001         void *msg_header = NULL;
2002         int ret = 0;
2003
2004         ret = tcmu_netlink_event_init(udev, TCMU_CMD_REMOVED_DEVICE,
2005                                       &skb, &msg_header);
2006         if (ret < 0)
2007                 return ret;
2008         return tcmu_netlink_event_send(udev, TCMU_CMD_REMOVED_DEVICE,
2009                                        skb, msg_header);
2010 }
2011
2012 static int tcmu_update_uio_info(struct tcmu_dev *udev)
2013 {
2014         struct tcmu_hba *hba = udev->hba->hba_ptr;
2015         struct uio_info *info;
2016         char *str;
2017
2018         info = &udev->uio_info;
2019
2020         if (udev->dev_config[0])
2021                 str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s/%s", hba->host_id,
2022                                 udev->name, udev->dev_config);
2023         else
2024                 str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s", hba->host_id,
2025                                 udev->name);
2026         if (!str)
2027                 return -ENOMEM;
2028
2029         /* If the old string exists, free it */
2030         kfree(info->name);
2031         info->name = str;
2032
2033         return 0;
2034 }
2035
2036 static int tcmu_configure_device(struct se_device *dev)
2037 {
2038         struct tcmu_dev *udev = TCMU_DEV(dev);
2039         struct uio_info *info;
2040         struct tcmu_mailbox *mb;
2041         int ret = 0;
2042
2043         ret = tcmu_update_uio_info(udev);
2044         if (ret)
2045                 return ret;
2046
2047         info = &udev->uio_info;
2048
2049         mutex_lock(&udev->cmdr_lock);
2050         udev->data_bitmap = bitmap_zalloc(udev->max_blocks, GFP_KERNEL);
2051         mutex_unlock(&udev->cmdr_lock);
2052         if (!udev->data_bitmap) {
2053                 ret = -ENOMEM;
2054                 goto err_bitmap_alloc;
2055         }
2056
2057         udev->mb_addr = vzalloc(CMDR_SIZE);
2058         if (!udev->mb_addr) {
2059                 ret = -ENOMEM;
2060                 goto err_vzalloc;
2061         }
2062
2063         /* mailbox fits in first part of CMDR space */
2064         udev->cmdr_size = CMDR_SIZE - CMDR_OFF;
2065         udev->data_off = CMDR_SIZE;
2066         udev->data_size = udev->max_blocks * DATA_BLOCK_SIZE;
2067         udev->dbi_thresh = 0; /* Default in Idle state */
2068
2069         /* Initialise the mailbox of the ring buffer */
2070         mb = udev->mb_addr;
2071         mb->version = TCMU_MAILBOX_VERSION;
2072         mb->flags = TCMU_MAILBOX_FLAG_CAP_OOOC |
2073                     TCMU_MAILBOX_FLAG_CAP_READ_LEN |
2074                     TCMU_MAILBOX_FLAG_CAP_TMR;
2075         mb->cmdr_off = CMDR_OFF;
2076         mb->cmdr_size = udev->cmdr_size;
2077
2078         WARN_ON(!PAGE_ALIGNED(udev->data_off));
2079         WARN_ON(udev->data_size % PAGE_SIZE);
2080         WARN_ON(udev->data_size % DATA_BLOCK_SIZE);
2081
2082         info->version = __stringify(TCMU_MAILBOX_VERSION);
2083
2084         info->mem[0].name = "tcm-user command & data buffer";
2085         info->mem[0].addr = (phys_addr_t)(uintptr_t)udev->mb_addr;
2086         info->mem[0].size = udev->ring_size = udev->data_size + CMDR_SIZE;
2087         info->mem[0].memtype = UIO_MEM_NONE;
2088
2089         info->irqcontrol = tcmu_irqcontrol;
2090         info->irq = UIO_IRQ_CUSTOM;
2091
2092         info->mmap = tcmu_mmap;
2093         info->open = tcmu_open;
2094         info->release = tcmu_release;
2095
2096         ret = uio_register_device(tcmu_root_device, info);
2097         if (ret)
2098                 goto err_register;
2099
2100         /* User can set hw_block_size before enable the device */
2101         if (dev->dev_attrib.hw_block_size == 0)
2102                 dev->dev_attrib.hw_block_size = 512;
2103         /* Other attributes can be configured in userspace */
2104         if (!dev->dev_attrib.hw_max_sectors)
2105                 dev->dev_attrib.hw_max_sectors = 128;
2106         if (!dev->dev_attrib.emulate_write_cache)
2107                 dev->dev_attrib.emulate_write_cache = 0;
2108         dev->dev_attrib.hw_queue_depth = 128;
2109
2110         /* If user didn't explicitly disable netlink reply support, use
2111          * module scope setting.
2112          */
2113         if (udev->nl_reply_supported >= 0)
2114                 udev->nl_reply_supported = tcmu_kern_cmd_reply_supported;
2115
2116         /*
2117          * Get a ref incase userspace does a close on the uio device before
2118          * LIO has initiated tcmu_free_device.
2119          */
2120         kref_get(&udev->kref);
2121
2122         ret = tcmu_send_dev_add_event(udev);
2123         if (ret)
2124                 goto err_netlink;
2125
2126         mutex_lock(&root_udev_mutex);
2127         list_add(&udev->node, &root_udev);
2128         mutex_unlock(&root_udev_mutex);
2129
2130         return 0;
2131
2132 err_netlink:
2133         kref_put(&udev->kref, tcmu_dev_kref_release);
2134         uio_unregister_device(&udev->uio_info);
2135 err_register:
2136         vfree(udev->mb_addr);
2137         udev->mb_addr = NULL;
2138 err_vzalloc:
2139         bitmap_free(udev->data_bitmap);
2140         udev->data_bitmap = NULL;
2141 err_bitmap_alloc:
2142         kfree(info->name);
2143         info->name = NULL;
2144
2145         return ret;
2146 }
2147
2148 static void tcmu_free_device(struct se_device *dev)
2149 {
2150         struct tcmu_dev *udev = TCMU_DEV(dev);
2151
2152         /* release ref from init */
2153         kref_put(&udev->kref, tcmu_dev_kref_release);
2154 }
2155
2156 static void tcmu_destroy_device(struct se_device *dev)
2157 {
2158         struct tcmu_dev *udev = TCMU_DEV(dev);
2159
2160         del_timer_sync(&udev->cmd_timer);
2161         del_timer_sync(&udev->qfull_timer);
2162
2163         mutex_lock(&root_udev_mutex);
2164         list_del(&udev->node);
2165         mutex_unlock(&root_udev_mutex);
2166
2167         tcmu_send_dev_remove_event(udev);
2168
2169         uio_unregister_device(&udev->uio_info);
2170
2171         /* release ref from configure */
2172         kref_put(&udev->kref, tcmu_dev_kref_release);
2173 }
2174
2175 static void tcmu_unblock_dev(struct tcmu_dev *udev)
2176 {
2177         mutex_lock(&udev->cmdr_lock);
2178         clear_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags);
2179         mutex_unlock(&udev->cmdr_lock);
2180 }
2181
2182 static void tcmu_block_dev(struct tcmu_dev *udev)
2183 {
2184         mutex_lock(&udev->cmdr_lock);
2185
2186         if (test_and_set_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
2187                 goto unlock;
2188
2189         /* complete IO that has executed successfully */
2190         tcmu_handle_completions(udev);
2191         /* fail IO waiting to be queued */
2192         run_qfull_queue(udev, true);
2193
2194 unlock:
2195         mutex_unlock(&udev->cmdr_lock);
2196 }
2197
2198 static void tcmu_reset_ring(struct tcmu_dev *udev, u8 err_level)
2199 {
2200         struct tcmu_mailbox *mb;
2201         struct tcmu_cmd *cmd;
2202         int i;
2203
2204         mutex_lock(&udev->cmdr_lock);
2205
2206         idr_for_each_entry(&udev->commands, cmd, i) {
2207                 pr_debug("removing cmd %u on dev %s from ring (is expired %d)\n",
2208                           cmd->cmd_id, udev->name,
2209                           test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags));
2210
2211                 idr_remove(&udev->commands, i);
2212                 if (!test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
2213                         WARN_ON(!cmd->se_cmd);
2214                         list_del_init(&cmd->queue_entry);
2215                         if (err_level == 1) {
2216                                 /*
2217                                  * Userspace was not able to start the
2218                                  * command or it is retryable.
2219                                  */
2220                                 target_complete_cmd(cmd->se_cmd, SAM_STAT_BUSY);
2221                         } else {
2222                                 /* hard failure */
2223                                 target_complete_cmd(cmd->se_cmd,
2224                                                     SAM_STAT_CHECK_CONDITION);
2225                         }
2226                 }
2227                 tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
2228                 tcmu_free_cmd(cmd);
2229         }
2230
2231         mb = udev->mb_addr;
2232         tcmu_flush_dcache_range(mb, sizeof(*mb));
2233         pr_debug("mb last %u head %u tail %u\n", udev->cmdr_last_cleaned,
2234                  mb->cmd_tail, mb->cmd_head);
2235
2236         udev->cmdr_last_cleaned = 0;
2237         mb->cmd_tail = 0;
2238         mb->cmd_head = 0;
2239         tcmu_flush_dcache_range(mb, sizeof(*mb));
2240         clear_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
2241
2242         del_timer(&udev->cmd_timer);
2243
2244         /*
2245          * ring is empty and qfull queue never contains aborted commands.
2246          * So TMRs in tmr queue do not contain relevant cmd_ids.
2247          * After a ring reset userspace should do a fresh start, so
2248          * even LUN RESET message is no longer relevant.
2249          * Therefore remove all TMRs from qfull queue
2250          */
2251         tcmu_remove_all_queued_tmr(udev);
2252
2253         run_qfull_queue(udev, false);
2254
2255         mutex_unlock(&udev->cmdr_lock);
2256 }
2257
2258 enum {
2259         Opt_dev_config, Opt_dev_size, Opt_hw_block_size, Opt_hw_max_sectors,
2260         Opt_nl_reply_supported, Opt_max_data_area_mb, Opt_err,
2261 };
2262
2263 static match_table_t tokens = {
2264         {Opt_dev_config, "dev_config=%s"},
2265         {Opt_dev_size, "dev_size=%s"},
2266         {Opt_hw_block_size, "hw_block_size=%d"},
2267         {Opt_hw_max_sectors, "hw_max_sectors=%d"},
2268         {Opt_nl_reply_supported, "nl_reply_supported=%d"},
2269         {Opt_max_data_area_mb, "max_data_area_mb=%d"},
2270         {Opt_err, NULL}
2271 };
2272
2273 static int tcmu_set_dev_attrib(substring_t *arg, u32 *dev_attrib)
2274 {
2275         int val, ret;
2276
2277         ret = match_int(arg, &val);
2278         if (ret < 0) {
2279                 pr_err("match_int() failed for dev attrib. Error %d.\n",
2280                        ret);
2281                 return ret;
2282         }
2283
2284         if (val <= 0) {
2285                 pr_err("Invalid dev attrib value %d. Must be greater than zero.\n",
2286                        val);
2287                 return -EINVAL;
2288         }
2289         *dev_attrib = val;
2290         return 0;
2291 }
2292
2293 static int tcmu_set_max_blocks_param(struct tcmu_dev *udev, substring_t *arg)
2294 {
2295         int val, ret;
2296
2297         ret = match_int(arg, &val);
2298         if (ret < 0) {
2299                 pr_err("match_int() failed for max_data_area_mb=. Error %d.\n",
2300                        ret);
2301                 return ret;
2302         }
2303
2304         if (val <= 0) {
2305                 pr_err("Invalid max_data_area %d.\n", val);
2306                 return -EINVAL;
2307         }
2308
2309         mutex_lock(&udev->cmdr_lock);
2310         if (udev->data_bitmap) {
2311                 pr_err("Cannot set max_data_area_mb after it has been enabled.\n");
2312                 ret = -EINVAL;
2313                 goto unlock;
2314         }
2315
2316         udev->max_blocks = TCMU_MBS_TO_BLOCKS(val);
2317         if (udev->max_blocks > tcmu_global_max_blocks) {
2318                 pr_err("%d is too large. Adjusting max_data_area_mb to global limit of %u\n",
2319                        val, TCMU_BLOCKS_TO_MBS(tcmu_global_max_blocks));
2320                 udev->max_blocks = tcmu_global_max_blocks;
2321         }
2322
2323 unlock:
2324         mutex_unlock(&udev->cmdr_lock);
2325         return ret;
2326 }
2327
2328 static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev,
2329                 const char *page, ssize_t count)
2330 {
2331         struct tcmu_dev *udev = TCMU_DEV(dev);
2332         char *orig, *ptr, *opts;
2333         substring_t args[MAX_OPT_ARGS];
2334         int ret = 0, token;
2335
2336         opts = kstrdup(page, GFP_KERNEL);
2337         if (!opts)
2338                 return -ENOMEM;
2339
2340         orig = opts;
2341
2342         while ((ptr = strsep(&opts, ",\n")) != NULL) {
2343                 if (!*ptr)
2344                         continue;
2345
2346                 token = match_token(ptr, tokens, args);
2347                 switch (token) {
2348                 case Opt_dev_config:
2349                         if (match_strlcpy(udev->dev_config, &args[0],
2350                                           TCMU_CONFIG_LEN) == 0) {
2351                                 ret = -EINVAL;
2352                                 break;
2353                         }
2354                         pr_debug("TCMU: Referencing Path: %s\n", udev->dev_config);
2355                         break;
2356                 case Opt_dev_size:
2357                         ret = match_u64(&args[0], &udev->dev_size);
2358                         if (ret < 0)
2359                                 pr_err("match_u64() failed for dev_size=. Error %d.\n",
2360                                        ret);
2361                         break;
2362                 case Opt_hw_block_size:
2363                         ret = tcmu_set_dev_attrib(&args[0],
2364                                         &(dev->dev_attrib.hw_block_size));
2365                         break;
2366                 case Opt_hw_max_sectors:
2367                         ret = tcmu_set_dev_attrib(&args[0],
2368                                         &(dev->dev_attrib.hw_max_sectors));
2369                         break;
2370                 case Opt_nl_reply_supported:
2371                         ret = match_int(&args[0], &udev->nl_reply_supported);
2372                         if (ret < 0)
2373                                 pr_err("match_int() failed for nl_reply_supported=. Error %d.\n",
2374                                        ret);
2375                         break;
2376                 case Opt_max_data_area_mb:
2377                         ret = tcmu_set_max_blocks_param(udev, &args[0]);
2378                         break;
2379                 default:
2380                         break;
2381                 }
2382
2383                 if (ret)
2384                         break;
2385         }
2386
2387         kfree(orig);
2388         return (!ret) ? count : ret;
2389 }
2390
2391 static ssize_t tcmu_show_configfs_dev_params(struct se_device *dev, char *b)
2392 {
2393         struct tcmu_dev *udev = TCMU_DEV(dev);
2394         ssize_t bl = 0;
2395
2396         bl = sprintf(b + bl, "Config: %s ",
2397                      udev->dev_config[0] ? udev->dev_config : "NULL");
2398         bl += sprintf(b + bl, "Size: %llu ", udev->dev_size);
2399         bl += sprintf(b + bl, "MaxDataAreaMB: %u\n",
2400                       TCMU_BLOCKS_TO_MBS(udev->max_blocks));
2401
2402         return bl;
2403 }
2404
2405 static sector_t tcmu_get_blocks(struct se_device *dev)
2406 {
2407         struct tcmu_dev *udev = TCMU_DEV(dev);
2408
2409         return div_u64(udev->dev_size - dev->dev_attrib.block_size,
2410                        dev->dev_attrib.block_size);
2411 }
2412
2413 static sense_reason_t
2414 tcmu_parse_cdb(struct se_cmd *cmd)
2415 {
2416         return passthrough_parse_cdb(cmd, tcmu_queue_cmd);
2417 }
2418
2419 static ssize_t tcmu_cmd_time_out_show(struct config_item *item, char *page)
2420 {
2421         struct se_dev_attrib *da = container_of(to_config_group(item),
2422                                         struct se_dev_attrib, da_group);
2423         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2424
2425         return snprintf(page, PAGE_SIZE, "%lu\n", udev->cmd_time_out / MSEC_PER_SEC);
2426 }
2427
2428 static ssize_t tcmu_cmd_time_out_store(struct config_item *item, const char *page,
2429                                        size_t count)
2430 {
2431         struct se_dev_attrib *da = container_of(to_config_group(item),
2432                                         struct se_dev_attrib, da_group);
2433         struct tcmu_dev *udev = container_of(da->da_dev,
2434                                         struct tcmu_dev, se_dev);
2435         u32 val;
2436         int ret;
2437
2438         if (da->da_dev->export_count) {
2439                 pr_err("Unable to set tcmu cmd_time_out while exports exist\n");
2440                 return -EINVAL;
2441         }
2442
2443         ret = kstrtou32(page, 0, &val);
2444         if (ret < 0)
2445                 return ret;
2446
2447         udev->cmd_time_out = val * MSEC_PER_SEC;
2448         return count;
2449 }
2450 CONFIGFS_ATTR(tcmu_, cmd_time_out);
2451
2452 static ssize_t tcmu_qfull_time_out_show(struct config_item *item, char *page)
2453 {
2454         struct se_dev_attrib *da = container_of(to_config_group(item),
2455                                                 struct se_dev_attrib, da_group);
2456         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2457
2458         return snprintf(page, PAGE_SIZE, "%ld\n", udev->qfull_time_out <= 0 ?
2459                         udev->qfull_time_out :
2460                         udev->qfull_time_out / MSEC_PER_SEC);
2461 }
2462
2463 static ssize_t tcmu_qfull_time_out_store(struct config_item *item,
2464                                          const char *page, size_t count)
2465 {
2466         struct se_dev_attrib *da = container_of(to_config_group(item),
2467                                         struct se_dev_attrib, da_group);
2468         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2469         s32 val;
2470         int ret;
2471
2472         ret = kstrtos32(page, 0, &val);
2473         if (ret < 0)
2474                 return ret;
2475
2476         if (val >= 0) {
2477                 udev->qfull_time_out = val * MSEC_PER_SEC;
2478         } else if (val == -1) {
2479                 udev->qfull_time_out = val;
2480         } else {
2481                 printk(KERN_ERR "Invalid qfull timeout value %d\n", val);
2482                 return -EINVAL;
2483         }
2484         return count;
2485 }
2486 CONFIGFS_ATTR(tcmu_, qfull_time_out);
2487
2488 static ssize_t tcmu_max_data_area_mb_show(struct config_item *item, char *page)
2489 {
2490         struct se_dev_attrib *da = container_of(to_config_group(item),
2491                                                 struct se_dev_attrib, da_group);
2492         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2493
2494         return snprintf(page, PAGE_SIZE, "%u\n",
2495                         TCMU_BLOCKS_TO_MBS(udev->max_blocks));
2496 }
2497 CONFIGFS_ATTR_RO(tcmu_, max_data_area_mb);
2498
2499 static ssize_t tcmu_dev_config_show(struct config_item *item, char *page)
2500 {
2501         struct se_dev_attrib *da = container_of(to_config_group(item),
2502                                                 struct se_dev_attrib, da_group);
2503         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2504
2505         return snprintf(page, PAGE_SIZE, "%s\n", udev->dev_config);
2506 }
2507
2508 static int tcmu_send_dev_config_event(struct tcmu_dev *udev,
2509                                       const char *reconfig_data)
2510 {
2511         struct sk_buff *skb = NULL;
2512         void *msg_header = NULL;
2513         int ret = 0;
2514
2515         ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2516                                       &skb, &msg_header);
2517         if (ret < 0)
2518                 return ret;
2519         ret = nla_put_string(skb, TCMU_ATTR_DEV_CFG, reconfig_data);
2520         if (ret < 0) {
2521                 nlmsg_free(skb);
2522                 return ret;
2523         }
2524         return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2525                                        skb, msg_header);
2526 }
2527
2528
2529 static ssize_t tcmu_dev_config_store(struct config_item *item, const char *page,
2530                                      size_t count)
2531 {
2532         struct se_dev_attrib *da = container_of(to_config_group(item),
2533                                                 struct se_dev_attrib, da_group);
2534         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2535         int ret, len;
2536
2537         len = strlen(page);
2538         if (!len || len > TCMU_CONFIG_LEN - 1)
2539                 return -EINVAL;
2540
2541         /* Check if device has been configured before */
2542         if (target_dev_configured(&udev->se_dev)) {
2543                 ret = tcmu_send_dev_config_event(udev, page);
2544                 if (ret) {
2545                         pr_err("Unable to reconfigure device\n");
2546                         return ret;
2547                 }
2548                 strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2549
2550                 ret = tcmu_update_uio_info(udev);
2551                 if (ret)
2552                         return ret;
2553                 return count;
2554         }
2555         strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2556
2557         return count;
2558 }
2559 CONFIGFS_ATTR(tcmu_, dev_config);
2560
2561 static ssize_t tcmu_dev_size_show(struct config_item *item, char *page)
2562 {
2563         struct se_dev_attrib *da = container_of(to_config_group(item),
2564                                                 struct se_dev_attrib, da_group);
2565         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2566
2567         return snprintf(page, PAGE_SIZE, "%llu\n", udev->dev_size);
2568 }
2569
2570 static int tcmu_send_dev_size_event(struct tcmu_dev *udev, u64 size)
2571 {
2572         struct sk_buff *skb = NULL;
2573         void *msg_header = NULL;
2574         int ret = 0;
2575
2576         ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2577                                       &skb, &msg_header);
2578         if (ret < 0)
2579                 return ret;
2580         ret = nla_put_u64_64bit(skb, TCMU_ATTR_DEV_SIZE,
2581                                 size, TCMU_ATTR_PAD);
2582         if (ret < 0) {
2583                 nlmsg_free(skb);
2584                 return ret;
2585         }
2586         return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2587                                        skb, msg_header);
2588 }
2589
2590 static ssize_t tcmu_dev_size_store(struct config_item *item, const char *page,
2591                                    size_t count)
2592 {
2593         struct se_dev_attrib *da = container_of(to_config_group(item),
2594                                                 struct se_dev_attrib, da_group);
2595         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2596         u64 val;
2597         int ret;
2598
2599         ret = kstrtou64(page, 0, &val);
2600         if (ret < 0)
2601                 return ret;
2602
2603         /* Check if device has been configured before */
2604         if (target_dev_configured(&udev->se_dev)) {
2605                 ret = tcmu_send_dev_size_event(udev, val);
2606                 if (ret) {
2607                         pr_err("Unable to reconfigure device\n");
2608                         return ret;
2609                 }
2610         }
2611         udev->dev_size = val;
2612         return count;
2613 }
2614 CONFIGFS_ATTR(tcmu_, dev_size);
2615
2616 static ssize_t tcmu_nl_reply_supported_show(struct config_item *item,
2617                 char *page)
2618 {
2619         struct se_dev_attrib *da = container_of(to_config_group(item),
2620                                                 struct se_dev_attrib, da_group);
2621         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2622
2623         return snprintf(page, PAGE_SIZE, "%d\n", udev->nl_reply_supported);
2624 }
2625
2626 static ssize_t tcmu_nl_reply_supported_store(struct config_item *item,
2627                 const char *page, size_t count)
2628 {
2629         struct se_dev_attrib *da = container_of(to_config_group(item),
2630                                                 struct se_dev_attrib, da_group);
2631         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2632         s8 val;
2633         int ret;
2634
2635         ret = kstrtos8(page, 0, &val);
2636         if (ret < 0)
2637                 return ret;
2638
2639         udev->nl_reply_supported = val;
2640         return count;
2641 }
2642 CONFIGFS_ATTR(tcmu_, nl_reply_supported);
2643
2644 static ssize_t tcmu_emulate_write_cache_show(struct config_item *item,
2645                                              char *page)
2646 {
2647         struct se_dev_attrib *da = container_of(to_config_group(item),
2648                                         struct se_dev_attrib, da_group);
2649
2650         return snprintf(page, PAGE_SIZE, "%i\n", da->emulate_write_cache);
2651 }
2652
2653 static int tcmu_send_emulate_write_cache(struct tcmu_dev *udev, u8 val)
2654 {
2655         struct sk_buff *skb = NULL;
2656         void *msg_header = NULL;
2657         int ret = 0;
2658
2659         ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2660                                       &skb, &msg_header);
2661         if (ret < 0)
2662                 return ret;
2663         ret = nla_put_u8(skb, TCMU_ATTR_WRITECACHE, val);
2664         if (ret < 0) {
2665                 nlmsg_free(skb);
2666                 return ret;
2667         }
2668         return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2669                                        skb, msg_header);
2670 }
2671
2672 static ssize_t tcmu_emulate_write_cache_store(struct config_item *item,
2673                                               const char *page, size_t count)
2674 {
2675         struct se_dev_attrib *da = container_of(to_config_group(item),
2676                                         struct se_dev_attrib, da_group);
2677         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2678         u8 val;
2679         int ret;
2680
2681         ret = kstrtou8(page, 0, &val);
2682         if (ret < 0)
2683                 return ret;
2684
2685         /* Check if device has been configured before */
2686         if (target_dev_configured(&udev->se_dev)) {
2687                 ret = tcmu_send_emulate_write_cache(udev, val);
2688                 if (ret) {
2689                         pr_err("Unable to reconfigure device\n");
2690                         return ret;
2691                 }
2692         }
2693
2694         da->emulate_write_cache = val;
2695         return count;
2696 }
2697 CONFIGFS_ATTR(tcmu_, emulate_write_cache);
2698
2699 static ssize_t tcmu_tmr_notification_show(struct config_item *item, char *page)
2700 {
2701         struct se_dev_attrib *da = container_of(to_config_group(item),
2702                                         struct se_dev_attrib, da_group);
2703         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2704
2705         return snprintf(page, PAGE_SIZE, "%i\n",
2706                         test_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags));
2707 }
2708
2709 static ssize_t tcmu_tmr_notification_store(struct config_item *item,
2710                                            const char *page, size_t count)
2711 {
2712         struct se_dev_attrib *da = container_of(to_config_group(item),
2713                                         struct se_dev_attrib, da_group);
2714         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2715         u8 val;
2716         int ret;
2717
2718         ret = kstrtou8(page, 0, &val);
2719         if (ret < 0)
2720                 return ret;
2721         if (val > 1)
2722                 return -EINVAL;
2723
2724         if (val)
2725                 set_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags);
2726         else
2727                 clear_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags);
2728         return count;
2729 }
2730 CONFIGFS_ATTR(tcmu_, tmr_notification);
2731
2732 static ssize_t tcmu_block_dev_show(struct config_item *item, char *page)
2733 {
2734         struct se_device *se_dev = container_of(to_config_group(item),
2735                                                 struct se_device,
2736                                                 dev_action_group);
2737         struct tcmu_dev *udev = TCMU_DEV(se_dev);
2738
2739         if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
2740                 return snprintf(page, PAGE_SIZE, "%s\n", "blocked");
2741         else
2742                 return snprintf(page, PAGE_SIZE, "%s\n", "unblocked");
2743 }
2744
2745 static ssize_t tcmu_block_dev_store(struct config_item *item, const char *page,
2746                                     size_t count)
2747 {
2748         struct se_device *se_dev = container_of(to_config_group(item),
2749                                                 struct se_device,
2750                                                 dev_action_group);
2751         struct tcmu_dev *udev = TCMU_DEV(se_dev);
2752         u8 val;
2753         int ret;
2754
2755         if (!target_dev_configured(&udev->se_dev)) {
2756                 pr_err("Device is not configured.\n");
2757                 return -EINVAL;
2758         }
2759
2760         ret = kstrtou8(page, 0, &val);
2761         if (ret < 0)
2762                 return ret;
2763
2764         if (val > 1) {
2765                 pr_err("Invalid block value %d\n", val);
2766                 return -EINVAL;
2767         }
2768
2769         if (!val)
2770                 tcmu_unblock_dev(udev);
2771         else
2772                 tcmu_block_dev(udev);
2773         return count;
2774 }
2775 CONFIGFS_ATTR(tcmu_, block_dev);
2776
2777 static ssize_t tcmu_reset_ring_store(struct config_item *item, const char *page,
2778                                      size_t count)
2779 {
2780         struct se_device *se_dev = container_of(to_config_group(item),
2781                                                 struct se_device,
2782                                                 dev_action_group);
2783         struct tcmu_dev *udev = TCMU_DEV(se_dev);
2784         u8 val;
2785         int ret;
2786
2787         if (!target_dev_configured(&udev->se_dev)) {
2788                 pr_err("Device is not configured.\n");
2789                 return -EINVAL;
2790         }
2791
2792         ret = kstrtou8(page, 0, &val);
2793         if (ret < 0)
2794                 return ret;
2795
2796         if (val != 1 && val != 2) {
2797                 pr_err("Invalid reset ring value %d\n", val);
2798                 return -EINVAL;
2799         }
2800
2801         tcmu_reset_ring(udev, val);
2802         return count;
2803 }
2804 CONFIGFS_ATTR_WO(tcmu_, reset_ring);
2805
2806 static struct configfs_attribute *tcmu_attrib_attrs[] = {
2807         &tcmu_attr_cmd_time_out,
2808         &tcmu_attr_qfull_time_out,
2809         &tcmu_attr_max_data_area_mb,
2810         &tcmu_attr_dev_config,
2811         &tcmu_attr_dev_size,
2812         &tcmu_attr_emulate_write_cache,
2813         &tcmu_attr_tmr_notification,
2814         &tcmu_attr_nl_reply_supported,
2815         NULL,
2816 };
2817
2818 static struct configfs_attribute **tcmu_attrs;
2819
2820 static struct configfs_attribute *tcmu_action_attrs[] = {
2821         &tcmu_attr_block_dev,
2822         &tcmu_attr_reset_ring,
2823         NULL,
2824 };
2825
2826 static struct target_backend_ops tcmu_ops = {
2827         .name                   = "user",
2828         .owner                  = THIS_MODULE,
2829         .transport_flags_default = TRANSPORT_FLAG_PASSTHROUGH,
2830         .transport_flags_changeable = TRANSPORT_FLAG_PASSTHROUGH_PGR |
2831                                       TRANSPORT_FLAG_PASSTHROUGH_ALUA,
2832         .attach_hba             = tcmu_attach_hba,
2833         .detach_hba             = tcmu_detach_hba,
2834         .alloc_device           = tcmu_alloc_device,
2835         .configure_device       = tcmu_configure_device,
2836         .destroy_device         = tcmu_destroy_device,
2837         .free_device            = tcmu_free_device,
2838         .parse_cdb              = tcmu_parse_cdb,
2839         .tmr_notify             = tcmu_tmr_notify,
2840         .set_configfs_dev_params = tcmu_set_configfs_dev_params,
2841         .show_configfs_dev_params = tcmu_show_configfs_dev_params,
2842         .get_device_type        = sbc_get_device_type,
2843         .get_blocks             = tcmu_get_blocks,
2844         .tb_dev_action_attrs    = tcmu_action_attrs,
2845 };
2846
2847 static void find_free_blocks(void)
2848 {
2849         struct tcmu_dev *udev;
2850         loff_t off;
2851         u32 start, end, block, total_freed = 0;
2852
2853         if (atomic_read(&global_db_count) <= tcmu_global_max_blocks)
2854                 return;
2855
2856         mutex_lock(&root_udev_mutex);
2857         list_for_each_entry(udev, &root_udev, node) {
2858                 mutex_lock(&udev->cmdr_lock);
2859
2860                 if (!target_dev_configured(&udev->se_dev)) {
2861                         mutex_unlock(&udev->cmdr_lock);
2862                         continue;
2863                 }
2864
2865                 /* Try to complete the finished commands first */
2866                 if (tcmu_handle_completions(udev))
2867                         run_qfull_queue(udev, false);
2868
2869                 /* Skip the udevs in idle */
2870                 if (!udev->dbi_thresh) {
2871                         mutex_unlock(&udev->cmdr_lock);
2872                         continue;
2873                 }
2874
2875                 end = udev->dbi_max + 1;
2876                 block = find_last_bit(udev->data_bitmap, end);
2877                 if (block == udev->dbi_max) {
2878                         /*
2879                          * The last bit is dbi_max, so it is not possible
2880                          * reclaim any blocks.
2881                          */
2882                         mutex_unlock(&udev->cmdr_lock);
2883                         continue;
2884                 } else if (block == end) {
2885                         /* The current udev will goto idle state */
2886                         udev->dbi_thresh = start = 0;
2887                         udev->dbi_max = 0;
2888                 } else {
2889                         udev->dbi_thresh = start = block + 1;
2890                         udev->dbi_max = block;
2891                 }
2892
2893                 /* Here will truncate the data area from off */
2894                 off = udev->data_off + start * DATA_BLOCK_SIZE;
2895                 unmap_mapping_range(udev->inode->i_mapping, off, 0, 1);
2896
2897                 /* Release the block pages */
2898                 tcmu_blocks_release(&udev->data_blocks, start, end);
2899                 mutex_unlock(&udev->cmdr_lock);
2900
2901                 total_freed += end - start;
2902                 pr_debug("Freed %u blocks (total %u) from %s.\n", end - start,
2903                          total_freed, udev->name);
2904         }
2905         mutex_unlock(&root_udev_mutex);
2906
2907         if (atomic_read(&global_db_count) > tcmu_global_max_blocks)
2908                 schedule_delayed_work(&tcmu_unmap_work, msecs_to_jiffies(5000));
2909 }
2910
2911 static void check_timedout_devices(void)
2912 {
2913         struct tcmu_dev *udev, *tmp_dev;
2914         struct tcmu_cmd *cmd, *tmp_cmd;
2915         LIST_HEAD(devs);
2916
2917         spin_lock_bh(&timed_out_udevs_lock);
2918         list_splice_init(&timed_out_udevs, &devs);
2919
2920         list_for_each_entry_safe(udev, tmp_dev, &devs, timedout_entry) {
2921                 list_del_init(&udev->timedout_entry);
2922                 spin_unlock_bh(&timed_out_udevs_lock);
2923
2924                 mutex_lock(&udev->cmdr_lock);
2925
2926                 /*
2927                  * If cmd_time_out is disabled but qfull is set deadline
2928                  * will only reflect the qfull timeout. Ignore it.
2929                  */
2930                 if (udev->cmd_time_out) {
2931                         list_for_each_entry_safe(cmd, tmp_cmd,
2932                                                  &udev->inflight_queue,
2933                                                  queue_entry) {
2934                                 tcmu_check_expired_ring_cmd(cmd);
2935                         }
2936                         tcmu_set_next_deadline(&udev->inflight_queue,
2937                                                &udev->cmd_timer);
2938                 }
2939                 list_for_each_entry_safe(cmd, tmp_cmd, &udev->qfull_queue,
2940                                          queue_entry) {
2941                         tcmu_check_expired_queue_cmd(cmd);
2942                 }
2943                 tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
2944
2945                 mutex_unlock(&udev->cmdr_lock);
2946
2947                 spin_lock_bh(&timed_out_udevs_lock);
2948         }
2949
2950         spin_unlock_bh(&timed_out_udevs_lock);
2951 }
2952
2953 static void tcmu_unmap_work_fn(struct work_struct *work)
2954 {
2955         check_timedout_devices();
2956         find_free_blocks();
2957 }
2958
2959 static int __init tcmu_module_init(void)
2960 {
2961         int ret, i, k, len = 0;
2962
2963         BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry) % TCMU_OP_ALIGN_SIZE) != 0);
2964
2965         INIT_DELAYED_WORK(&tcmu_unmap_work, tcmu_unmap_work_fn);
2966
2967         tcmu_cmd_cache = kmem_cache_create("tcmu_cmd_cache",
2968                                 sizeof(struct tcmu_cmd),
2969                                 __alignof__(struct tcmu_cmd),
2970                                 0, NULL);
2971         if (!tcmu_cmd_cache)
2972                 return -ENOMEM;
2973
2974         tcmu_root_device = root_device_register("tcm_user");
2975         if (IS_ERR(tcmu_root_device)) {
2976                 ret = PTR_ERR(tcmu_root_device);
2977                 goto out_free_cache;
2978         }
2979
2980         ret = genl_register_family(&tcmu_genl_family);
2981         if (ret < 0) {
2982                 goto out_unreg_device;
2983         }
2984
2985         for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
2986                 len += sizeof(struct configfs_attribute *);
2987         for (i = 0; passthrough_pr_attrib_attrs[i] != NULL; i++)
2988                 len += sizeof(struct configfs_attribute *);
2989         for (i = 0; tcmu_attrib_attrs[i] != NULL; i++)
2990                 len += sizeof(struct configfs_attribute *);
2991         len += sizeof(struct configfs_attribute *);
2992
2993         tcmu_attrs = kzalloc(len, GFP_KERNEL);
2994         if (!tcmu_attrs) {
2995                 ret = -ENOMEM;
2996                 goto out_unreg_genl;
2997         }
2998
2999         for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
3000                 tcmu_attrs[i] = passthrough_attrib_attrs[i];
3001         for (k = 0; passthrough_pr_attrib_attrs[k] != NULL; k++)
3002                 tcmu_attrs[i++] = passthrough_pr_attrib_attrs[k];
3003         for (k = 0; tcmu_attrib_attrs[k] != NULL; k++)
3004                 tcmu_attrs[i++] = tcmu_attrib_attrs[k];
3005         tcmu_ops.tb_dev_attrib_attrs = tcmu_attrs;
3006
3007         ret = transport_backend_register(&tcmu_ops);
3008         if (ret)
3009                 goto out_attrs;
3010
3011         return 0;
3012
3013 out_attrs:
3014         kfree(tcmu_attrs);
3015 out_unreg_genl:
3016         genl_unregister_family(&tcmu_genl_family);
3017 out_unreg_device:
3018         root_device_unregister(tcmu_root_device);
3019 out_free_cache:
3020         kmem_cache_destroy(tcmu_cmd_cache);
3021
3022         return ret;
3023 }
3024
3025 static void __exit tcmu_module_exit(void)
3026 {
3027         cancel_delayed_work_sync(&tcmu_unmap_work);
3028         target_backend_unregister(&tcmu_ops);
3029         kfree(tcmu_attrs);
3030         genl_unregister_family(&tcmu_genl_family);
3031         root_device_unregister(tcmu_root_device);
3032         kmem_cache_destroy(tcmu_cmd_cache);
3033 }
3034
3035 MODULE_DESCRIPTION("TCM USER subsystem plugin");
3036 MODULE_AUTHOR("Shaohua Li <shli@kernel.org>");
3037 MODULE_AUTHOR("Andy Grover <agrover@redhat.com>");
3038 MODULE_LICENSE("GPL");
3039
3040 module_init(tcmu_module_init);
3041 module_exit(tcmu_module_exit);