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 *remain)
 590 {
 591         /* Get the next dbi */
 592         int dbi = tcmu_cmd_get_dbi(cmd);
 593         /* Do not add more than DATA_BLOCK_SIZE to iov */
 594         int len = min_t(int, DATA_BLOCK_SIZE, *remain);
 595
 596         *remain -= len;
 597         /*
 598          * The following code will gather and map the blocks to the same iovec
 599          * when the blocks are all next to each other.
 600          */
 601         if (dbi != prev_dbi + 1) {
 602                 /* dbi is not next to previous dbi, so start new iov */
 603                 if (prev_dbi >= 0)
 604                         (*iov)++;
 605                 /* write offset relative to mb_addr */
 606                 (*iov)->iov_base = (void __user *)
 607                                 (udev->data_off + dbi * DATA_BLOCK_SIZE);
 608         }
 609         (*iov)->iov_len += len;
 610
 611         return dbi;
 612 }
 613
 614 static void tcmu_setup_iovs(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
 615                             struct iovec **iov, int data_length)
 616 {
 617         /* start value of dbi + 1 must not be a valid dbi */
 618         int dbi = -2;
 619
 620         /* We prepare the IOVs for DMA_FROM_DEVICE transfer direction */
 621         while (data_length > 0)
 622                 dbi = new_block_to_iov(udev, cmd, iov, dbi, &data_length);
 623 }
 624
 625 static struct tcmu_cmd *tcmu_alloc_cmd(struct se_cmd *se_cmd)
 626 {
 627         struct se_device *se_dev = se_cmd->se_dev;
 628         struct tcmu_dev *udev = TCMU_DEV(se_dev);
 629         struct tcmu_cmd *tcmu_cmd;
 630
 631         tcmu_cmd = kmem_cache_zalloc(tcmu_cmd_cache, GFP_NOIO);
 632         if (!tcmu_cmd)
 633                 return NULL;
 634
 635         INIT_LIST_HEAD(&tcmu_cmd->queue_entry);
 636         tcmu_cmd->se_cmd = se_cmd;
 637         tcmu_cmd->tcmu_dev = udev;
 638
 639         tcmu_cmd_set_block_cnts(tcmu_cmd);
 640         tcmu_cmd->dbi = kcalloc(tcmu_cmd->dbi_cnt, sizeof(uint32_t),
 641                                 GFP_NOIO);
 642         if (!tcmu_cmd->dbi) {
 643                 kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
 644                 return NULL;
 645         }
 646
 647         return tcmu_cmd;
 648 }
 649
 650 static inline void tcmu_flush_dcache_range(void *vaddr, size_t size)
 651 {
 652         unsigned long offset = offset_in_page(vaddr);
 653         void *start = vaddr - offset;
 654
 655         size = round_up(size+offset, PAGE_SIZE);
 656
 657         while (size) {
 658                 flush_dcache_page(vmalloc_to_page(start));
 659                 start += PAGE_SIZE;
 660                 size -= PAGE_SIZE;
 661         }
 662 }
 663
 664 /*
 665  * Some ring helper functions. We don't assume size is a power of 2 so
 666  * we can't use circ_buf.h.
 667  */
 668 static inline size_t spc_used(size_t head, size_t tail, size_t size)
 669 {
 670         int diff = head - tail;
 671
 672         if (diff >= 0)
 673                 return diff;
 674         else
 675                 return size + diff;
 676 }
 677
 678 static inline size_t spc_free(size_t head, size_t tail, size_t size)
 679 {
 680         /* Keep 1 byte unused or we can't tell full from empty */
 681         return (size - spc_used(head, tail, size) - 1);
 682 }
 683
 684 static inline size_t head_to_end(size_t head, size_t size)
 685 {
 686         return size - head;
 687 }
 688
 689 #define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size)
 690
 691 static void scatter_data_area(struct tcmu_dev *udev, struct tcmu_cmd *tcmu_cmd,
 692                               struct iovec **iov)
 693 {
 694         struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
 695         /* start value of dbi + 1 must not be a valid dbi */
 696         int i, dbi = -2;
 697         int block_remaining = 0;
 698         int data_len = se_cmd->data_length;
 699         void *from, *to = NULL;
 700         size_t copy_bytes, offset;
 701         struct scatterlist *sg;
 702         struct page *page = NULL;
 703
 704         for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, i) {
 705                 int sg_remaining = sg->length;
 706                 from = kmap_atomic(sg_page(sg)) + sg->offset;
 707                 while (sg_remaining > 0) {
 708                         if (block_remaining == 0) {
 709                                 if (to) {
 710                                         flush_dcache_page(page);
 711                                         kunmap_atomic(to);
 712                                 }
 713
 714                                 /* get next dbi and add to IOVs */
 715                                 dbi = new_block_to_iov(udev, tcmu_cmd, iov, dbi,
 716                                                        &data_len);
 717                                 page = tcmu_get_block_page(udev, dbi);
 718                                 to = kmap_atomic(page);
 719                                 block_remaining = DATA_BLOCK_SIZE;
 720                         }
 721
 722                         copy_bytes = min_t(size_t, sg_remaining,
 723                                         block_remaining);
 724                         offset = DATA_BLOCK_SIZE - block_remaining;
 725                         memcpy(to + offset, from + sg->length - sg_remaining,
 726                                copy_bytes);
 727
 728                         sg_remaining -= copy_bytes;
 729                         block_remaining -= copy_bytes;
 730                 }
 731                 kunmap_atomic(from - sg->offset);
 732         }
 733
 734         if (to) {
 735                 flush_dcache_page(page);
 736                 kunmap_atomic(to);
 737         }
 738 }
 739
 740 static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
 741                              bool bidi, uint32_t read_len)
 742 {
 743         struct se_cmd *se_cmd = cmd->se_cmd;
 744         int i, dbi;
 745         int block_remaining = 0;
 746         void *from = NULL, *to;
 747         size_t copy_bytes, offset;
 748         struct scatterlist *sg, *data_sg;
 749         struct page *page;
 750         unsigned int data_nents;
 751         uint32_t count = 0;
 752
 753         if (!bidi) {
 754                 data_sg = se_cmd->t_data_sg;
 755                 data_nents = se_cmd->t_data_nents;
 756         } else {
 757                 /*
 758                  * For bidi case, the first count blocks are for Data-Out
 759                  * buffer blocks, and before gathering the Data-In buffer
 760                  * the Data-Out buffer blocks should be skipped.
 761                  */
 762                 count = cmd->dbi_cnt - cmd->dbi_bidi_cnt;
 763
 764                 data_sg = se_cmd->t_bidi_data_sg;
 765                 data_nents = se_cmd->t_bidi_data_nents;
 766         }
 767
 768         tcmu_cmd_set_dbi_cur(cmd, count);
 769
 770         for_each_sg(data_sg, sg, data_nents, i) {
 771                 int sg_remaining = sg->length;
 772                 to = kmap_atomic(sg_page(sg)) + sg->offset;
 773                 while (sg_remaining > 0 && read_len > 0) {
 774                         if (block_remaining == 0) {
 775                                 if (from)
 776                                         kunmap_atomic(from);
 777
 778                                 block_remaining = DATA_BLOCK_SIZE;
 779                                 dbi = tcmu_cmd_get_dbi(cmd);
 780                                 page = tcmu_get_block_page(udev, dbi);
 781                                 from = kmap_atomic(page);
 782                                 flush_dcache_page(page);
 783                         }
 784                         copy_bytes = min_t(size_t, sg_remaining,
 785                                         block_remaining);
 786                         if (read_len < copy_bytes)
 787                                 copy_bytes = read_len;
 788                         offset = DATA_BLOCK_SIZE - block_remaining;
 789                         memcpy(to + sg->length - sg_remaining, from + offset,
 790                                         copy_bytes);
 791
 792                         sg_remaining -= copy_bytes;
 793                         block_remaining -= copy_bytes;
 794                         read_len -= copy_bytes;
 795                 }
 796                 kunmap_atomic(to - sg->offset);
 797                 if (read_len == 0)
 798                         break;
 799         }
 800         if (from)
 801                 kunmap_atomic(from);
 802 }
 803
 804 static inline size_t spc_bitmap_free(unsigned long *bitmap, uint32_t thresh)
 805 {
 806         return thresh - bitmap_weight(bitmap, thresh);
 807 }
 808
 809 /*
 810  * We can't queue a command until we have space available on the cmd ring.
 811  *
 812  * Called with ring lock held.
 813  */
 814 static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size)
 815 {
 816         struct tcmu_mailbox *mb = udev->mb_addr;
 817         size_t space, cmd_needed;
 818         u32 cmd_head;
 819
 820         tcmu_flush_dcache_range(mb, sizeof(*mb));
 821
 822         cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
 823
 824         /*
 825          * If cmd end-of-ring space is too small then we need space for a NOP plus
 826          * original cmd - cmds are internally contiguous.
 827          */
 828         if (head_to_end(cmd_head, udev->cmdr_size) >= cmd_size)
 829                 cmd_needed = cmd_size;
 830         else
 831                 cmd_needed = cmd_size + head_to_end(cmd_head, udev->cmdr_size);
 832
 833         space = spc_free(cmd_head, udev->cmdr_last_cleaned, udev->cmdr_size);
 834         if (space < cmd_needed) {
 835                 pr_debug("no cmd space: %u %u %u\n", cmd_head,
 836                        udev->cmdr_last_cleaned, udev->cmdr_size);
 837                 return false;
 838         }
 839         return true;
 840 }
 841
 842 /*
 843  * We have to allocate data buffers before we can queue a command.
 844  * Returns -1 on error (not enough space) or number of needed iovs on success
 845  *
 846  * Called with ring lock held.
 847  */
 848 static int tcmu_alloc_data_space(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
 849                                   int *iov_bidi_cnt)
 850 {
 851         int space, iov_cnt = 0, ret = 0;
 852
 853         if (!cmd->dbi_cnt)
 854                 goto wr_iov_cnts;
 855
 856         /* try to check and get the data blocks as needed */
 857         space = spc_bitmap_free(udev->data_bitmap, udev->dbi_thresh);
 858         if (space < cmd->dbi_cnt) {
 859                 unsigned long blocks_left =
 860                                 (udev->max_blocks - udev->dbi_thresh) + space;
 861
 862                 if (blocks_left < cmd->dbi_cnt) {
 863                         pr_debug("no data space: only %lu available, but ask for %lu\n",
 864                                         blocks_left * DATA_BLOCK_SIZE,
 865                                         cmd->dbi_cnt * DATA_BLOCK_SIZE);
 866                         return -1;
 867                 }
 868
 869                 udev->dbi_thresh += cmd->dbi_cnt;
 870                 if (udev->dbi_thresh > udev->max_blocks)
 871                         udev->dbi_thresh = udev->max_blocks;
 872         }
 873
 874         iov_cnt = tcmu_get_empty_blocks(udev, cmd,
 875                                         cmd->dbi_cnt - cmd->dbi_bidi_cnt);
 876         if (iov_cnt < 0)
 877                 return -1;
 878
 879         if (cmd->dbi_bidi_cnt) {
 880                 ret = tcmu_get_empty_blocks(udev, cmd, cmd->dbi_bidi_cnt);
 881                 if (ret < 0)
 882                         return -1;
 883         }
 884 wr_iov_cnts:
 885         *iov_bidi_cnt = ret;
 886         return iov_cnt + ret;
 887 }
 888
 889 static inline size_t tcmu_cmd_get_base_cmd_size(size_t iov_cnt)
 890 {
 891         return max(offsetof(struct tcmu_cmd_entry, req.iov[iov_cnt]),
 892                         sizeof(struct tcmu_cmd_entry));
 893 }
 894
 895 static inline size_t tcmu_cmd_get_cmd_size(struct tcmu_cmd *tcmu_cmd,
 896                                            size_t base_command_size)
 897 {
 898         struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
 899         size_t command_size;
 900
 901         command_size = base_command_size +
 902                 round_up(scsi_command_size(se_cmd->t_task_cdb),
 903                                 TCMU_OP_ALIGN_SIZE);
 904
 905         WARN_ON(command_size & (TCMU_OP_ALIGN_SIZE-1));
 906
 907         return command_size;
 908 }
 909
 910 static void tcmu_setup_cmd_timer(struct tcmu_cmd *tcmu_cmd, unsigned int tmo,
 911                                  struct timer_list *timer)
 912 {
 913         if (!tmo)
 914                 return;
 915
 916         tcmu_cmd->deadline = round_jiffies_up(jiffies + msecs_to_jiffies(tmo));
 917         if (!timer_pending(timer))
 918                 mod_timer(timer, tcmu_cmd->deadline);
 919
 920         pr_debug("Timeout set up for cmd %p, dev = %s, tmo = %lu\n", tcmu_cmd,
 921                  tcmu_cmd->tcmu_dev->name, tmo / MSEC_PER_SEC);
 922 }
 923
 924 static int add_to_qfull_queue(struct tcmu_cmd *tcmu_cmd)
 925 {
 926         struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
 927         unsigned int tmo;
 928
 929         /*
 930          * For backwards compat if qfull_time_out is not set use
 931          * cmd_time_out and if that's not set use the default time out.
 932          */
 933         if (!udev->qfull_time_out)
 934                 return -ETIMEDOUT;
 935         else if (udev->qfull_time_out > 0)
 936                 tmo = udev->qfull_time_out;
 937         else if (udev->cmd_time_out)
 938                 tmo = udev->cmd_time_out;
 939         else
 940                 tmo = TCMU_TIME_OUT;
 941
 942         tcmu_setup_cmd_timer(tcmu_cmd, tmo, &udev->qfull_timer);
 943
 944         list_add_tail(&tcmu_cmd->queue_entry, &udev->qfull_queue);
 945         pr_debug("adding cmd %p on dev %s to ring space wait queue\n",
 946                  tcmu_cmd, udev->name);
 947         return 0;
 948 }
 949
 950 static uint32_t ring_insert_padding(struct tcmu_dev *udev, size_t cmd_size)
 951 {
 952         struct tcmu_cmd_entry_hdr *hdr;
 953         struct tcmu_mailbox *mb = udev->mb_addr;
 954         uint32_t cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
 955
 956         /* Insert a PAD if end-of-ring space is too small */
 957         if (head_to_end(cmd_head, udev->cmdr_size) < cmd_size) {
 958                 size_t pad_size = head_to_end(cmd_head, udev->cmdr_size);
 959
 960                 hdr = (void *) mb + CMDR_OFF + cmd_head;
 961                 tcmu_hdr_set_op(&hdr->len_op, TCMU_OP_PAD);
 962                 tcmu_hdr_set_len(&hdr->len_op, pad_size);
 963                 hdr->cmd_id = 0; /* not used for PAD */
 964                 hdr->kflags = 0;
 965                 hdr->uflags = 0;
 966                 tcmu_flush_dcache_range(hdr, sizeof(*hdr));
 967
 968                 UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size);
 969                 tcmu_flush_dcache_range(mb, sizeof(*mb));
 970
 971                 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
 972                 WARN_ON(cmd_head != 0);
 973         }
 974
 975         return cmd_head;
 976 }
 977
 978 /**
 979  * queue_cmd_ring - queue cmd to ring or internally
 980  * @tcmu_cmd: cmd to queue
 981  * @scsi_err: TCM error code if failure (-1) returned.
 982  *
 983  * Returns:
 984  * -1 we cannot queue internally or to the ring.
 985  *  0 success
 986  *  1 internally queued to wait for ring memory to free.
 987  */
 988 static int queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, sense_reason_t *scsi_err)
 989 {
 990         struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
 991         struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
 992         size_t base_command_size, command_size;
 993         struct tcmu_mailbox *mb = udev->mb_addr;
 994         struct tcmu_cmd_entry *entry;
 995         struct iovec *iov;
 996         int iov_cnt, iov_bidi_cnt, cmd_id;
 997         uint32_t cmd_head;
 998         uint64_t cdb_off;
 999         /* size of data buffer needed */
1000         size_t data_length = (size_t)tcmu_cmd->dbi_cnt * DATA_BLOCK_SIZE;
1001
1002         *scsi_err = TCM_NO_SENSE;
1003
1004         if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags)) {
1005                 *scsi_err = TCM_LUN_BUSY;
1006                 return -1;
1007         }
1008
1009         if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
1010                 *scsi_err = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1011                 return -1;
1012         }
1013
1014         if (!list_empty(&udev->qfull_queue))
1015                 goto queue;
1016
1017         if (data_length > udev->data_size) {
1018                 pr_warn("TCMU: Request of size %zu is too big for %zu data area\n",
1019                         data_length, udev->data_size);
1020                 *scsi_err = TCM_INVALID_CDB_FIELD;
1021                 return -1;
1022         }
1023
1024         iov_cnt = tcmu_alloc_data_space(udev, tcmu_cmd, &iov_bidi_cnt);
1025         if (iov_cnt < 0)
1026                 goto free_and_queue;
1027
1028         /*
1029          * Must be a certain minimum size for response sense info, but
1030          * also may be larger if the iov array is large.
1031          */
1032         base_command_size = tcmu_cmd_get_base_cmd_size(iov_cnt);
1033         command_size = tcmu_cmd_get_cmd_size(tcmu_cmd, base_command_size);
1034
1035         if (command_size > (udev->cmdr_size / 2)) {
1036                 pr_warn("TCMU: Request of size %zu is too big for %u cmd ring\n",
1037                         command_size, udev->cmdr_size);
1038                 tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cur);
1039                 *scsi_err = TCM_INVALID_CDB_FIELD;
1040                 return -1;
1041         }
1042
1043         if (!is_ring_space_avail(udev, command_size))
1044                 /*
1045                  * Don't leave commands partially setup because the unmap
1046                  * thread might need the blocks to make forward progress.
1047                  */
1048                 goto free_and_queue;
1049
1050         cmd_id = idr_alloc(&udev->commands, tcmu_cmd, 1, USHRT_MAX, GFP_NOWAIT);
1051         if (cmd_id < 0) {
1052                 pr_err("tcmu: Could not allocate cmd id.\n");
1053
1054                 tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cnt);
1055                 *scsi_err = TCM_OUT_OF_RESOURCES;
1056                 return -1;
1057         }
1058         tcmu_cmd->cmd_id = cmd_id;
1059
1060         pr_debug("allocated cmd id %u for cmd %p dev %s\n", tcmu_cmd->cmd_id,
1061                  tcmu_cmd, udev->name);
1062
1063         cmd_head = ring_insert_padding(udev, command_size);
1064
1065         entry = (void *) mb + CMDR_OFF + cmd_head;
1066         memset(entry, 0, command_size);
1067         tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_CMD);
1068
1069         /* prepare iov list and copy data to data area if necessary */
1070         tcmu_cmd_reset_dbi_cur(tcmu_cmd);
1071         iov = &entry->req.iov[0];
1072
1073         if (se_cmd->data_direction == DMA_TO_DEVICE ||
1074             se_cmd->se_cmd_flags & SCF_BIDI)
1075                 scatter_data_area(udev, tcmu_cmd, &iov);
1076         else
1077                 tcmu_setup_iovs(udev, tcmu_cmd, &iov, se_cmd->data_length);
1078
1079         entry->req.iov_cnt = iov_cnt - iov_bidi_cnt;
1080
1081         /* Handle BIDI commands */
1082         if (se_cmd->se_cmd_flags & SCF_BIDI) {
1083                 iov++;
1084                 tcmu_setup_iovs(udev, tcmu_cmd, &iov, tcmu_cmd->data_len_bidi);
1085                 entry->req.iov_bidi_cnt = iov_bidi_cnt;
1086         }
1087
1088         tcmu_setup_cmd_timer(tcmu_cmd, udev->cmd_time_out, &udev->cmd_timer);
1089
1090         entry->hdr.cmd_id = tcmu_cmd->cmd_id;
1091
1092         tcmu_hdr_set_len(&entry->hdr.len_op, command_size);
1093
1094         /* All offsets relative to mb_addr, not start of entry! */
1095         cdb_off = CMDR_OFF + cmd_head + base_command_size;
1096         memcpy((void *) mb + cdb_off, se_cmd->t_task_cdb, scsi_command_size(se_cmd->t_task_cdb));
1097         entry->req.cdb_off = cdb_off;
1098         tcmu_flush_dcache_range(entry, command_size);
1099
1100         UPDATE_HEAD(mb->cmd_head, command_size, udev->cmdr_size);
1101         tcmu_flush_dcache_range(mb, sizeof(*mb));
1102
1103         list_add_tail(&tcmu_cmd->queue_entry, &udev->inflight_queue);
1104
1105         /* TODO: only if FLUSH and FUA? */
1106         uio_event_notify(&udev->uio_info);
1107
1108         return 0;
1109
1110 free_and_queue:
1111         tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cur);
1112         tcmu_cmd_reset_dbi_cur(tcmu_cmd);
1113
1114 queue:
1115         if (add_to_qfull_queue(tcmu_cmd)) {
1116                 *scsi_err = TCM_OUT_OF_RESOURCES;
1117                 return -1;
1118         }
1119
1120         return 1;
1121 }
1122
1123 /**
1124  * queue_tmr_ring - queue tmr info to ring or internally
1125  * @udev: related tcmu_dev
1126  * @tmr: tcmu_tmr containing tmr info to queue
1127  *
1128  * Returns:
1129  *  0 success
1130  *  1 internally queued to wait for ring memory to free.
1131  */
1132 static int
1133 queue_tmr_ring(struct tcmu_dev *udev, struct tcmu_tmr *tmr)
1134 {
1135         struct tcmu_tmr_entry *entry;
1136         int cmd_size;
1137         int id_list_sz;
1138         struct tcmu_mailbox *mb = udev->mb_addr;
1139         uint32_t cmd_head;
1140
1141         if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags))
1142                 goto out_free;
1143
1144         id_list_sz = sizeof(tmr->tmr_cmd_ids[0]) * tmr->tmr_cmd_cnt;
1145         cmd_size = round_up(sizeof(*entry) + id_list_sz, TCMU_OP_ALIGN_SIZE);
1146
1147         if (!list_empty(&udev->tmr_queue) ||
1148             !is_ring_space_avail(udev, cmd_size)) {
1149                 list_add_tail(&tmr->queue_entry, &udev->tmr_queue);
1150                 pr_debug("adding tmr %p on dev %s to TMR ring space wait queue\n",
1151                          tmr, udev->name);
1152                 return 1;
1153         }
1154
1155         cmd_head = ring_insert_padding(udev, cmd_size);
1156
1157         entry = (void *)mb + CMDR_OFF + cmd_head;
1158         memset(entry, 0, cmd_size);
1159         tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_TMR);
1160         tcmu_hdr_set_len(&entry->hdr.len_op, cmd_size);
1161         entry->tmr_type = tmr->tmr_type;
1162         entry->cmd_cnt = tmr->tmr_cmd_cnt;
1163         memcpy(&entry->cmd_ids[0], &tmr->tmr_cmd_ids[0], id_list_sz);
1164         tcmu_flush_dcache_range(entry, cmd_size);
1165
1166         UPDATE_HEAD(mb->cmd_head, cmd_size, udev->cmdr_size);
1167         tcmu_flush_dcache_range(mb, sizeof(*mb));
1168
1169         uio_event_notify(&udev->uio_info);
1170
1171 out_free:
1172         kfree(tmr);
1173
1174         return 0;
1175 }
1176
1177 static sense_reason_t
1178 tcmu_queue_cmd(struct se_cmd *se_cmd)
1179 {
1180         struct se_device *se_dev = se_cmd->se_dev;
1181         struct tcmu_dev *udev = TCMU_DEV(se_dev);
1182         struct tcmu_cmd *tcmu_cmd;
1183         sense_reason_t scsi_ret = TCM_CHECK_CONDITION_ABORT_CMD;
1184         int ret = -1;
1185
1186         tcmu_cmd = tcmu_alloc_cmd(se_cmd);
1187         if (!tcmu_cmd)
1188                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1189
1190         mutex_lock(&udev->cmdr_lock);
1191         se_cmd->priv = tcmu_cmd;
1192         if (!(se_cmd->transport_state & CMD_T_ABORTED))
1193                 ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
1194         if (ret < 0)
1195                 tcmu_free_cmd(tcmu_cmd);
1196         mutex_unlock(&udev->cmdr_lock);
1197         return scsi_ret;
1198 }
1199
1200 static void tcmu_set_next_deadline(struct list_head *queue,
1201                                    struct timer_list *timer)
1202 {
1203         struct tcmu_cmd *cmd;
1204
1205         if (!list_empty(queue)) {
1206                 cmd = list_first_entry(queue, struct tcmu_cmd, queue_entry);
1207                 mod_timer(timer, cmd->deadline);
1208         } else
1209                 del_timer(timer);
1210 }
1211
1212 static int
1213 tcmu_tmr_type(enum tcm_tmreq_table tmf)
1214 {
1215         switch (tmf) {
1216         case TMR_ABORT_TASK:            return TCMU_TMR_ABORT_TASK;
1217         case TMR_ABORT_TASK_SET:        return TCMU_TMR_ABORT_TASK_SET;
1218         case TMR_CLEAR_ACA:             return TCMU_TMR_CLEAR_ACA;
1219         case TMR_CLEAR_TASK_SET:        return TCMU_TMR_CLEAR_TASK_SET;
1220         case TMR_LUN_RESET:             return TCMU_TMR_LUN_RESET;
1221         case TMR_TARGET_WARM_RESET:     return TCMU_TMR_TARGET_WARM_RESET;
1222         case TMR_TARGET_COLD_RESET:     return TCMU_TMR_TARGET_COLD_RESET;
1223         case TMR_LUN_RESET_PRO:         return TCMU_TMR_LUN_RESET_PRO;
1224         default:                        return TCMU_TMR_UNKNOWN;
1225         }
1226 }
1227
1228 static void
1229 tcmu_tmr_notify(struct se_device *se_dev, enum tcm_tmreq_table tmf,
1230                 struct list_head *cmd_list)
1231 {
1232         int i = 0, cmd_cnt = 0;
1233         bool unqueued = false;
1234         uint16_t *cmd_ids = NULL;
1235         struct tcmu_cmd *cmd;
1236         struct se_cmd *se_cmd;
1237         struct tcmu_tmr *tmr;
1238         struct tcmu_dev *udev = TCMU_DEV(se_dev);
1239
1240         mutex_lock(&udev->cmdr_lock);
1241
1242         /* First we check for aborted commands in qfull_queue */
1243         list_for_each_entry(se_cmd, cmd_list, state_list) {
1244                 i++;
1245                 if (!se_cmd->priv)
1246                         continue;
1247                 cmd = se_cmd->priv;
1248                 /* Commands on qfull queue have no id yet */
1249                 if (cmd->cmd_id) {
1250                         cmd_cnt++;
1251                         continue;
1252                 }
1253                 pr_debug("Removing aborted command %p from queue on dev %s.\n",
1254                          cmd, udev->name);
1255
1256                 list_del_init(&cmd->queue_entry);
1257                 tcmu_free_cmd(cmd);
1258                 target_complete_cmd(se_cmd, SAM_STAT_TASK_ABORTED);
1259                 unqueued = true;
1260         }
1261         if (unqueued)
1262                 tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
1263
1264         if (!test_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags))
1265                 goto unlock;
1266
1267         pr_debug("TMR event %d on dev %s, aborted cmds %d, afflicted cmd_ids %d\n",
1268                  tcmu_tmr_type(tmf), udev->name, i, cmd_cnt);
1269
1270         tmr = kmalloc(sizeof(*tmr) + cmd_cnt * sizeof(*cmd_ids), GFP_KERNEL);
1271         if (!tmr)
1272                 goto unlock;
1273
1274         tmr->tmr_type = tcmu_tmr_type(tmf);
1275         tmr->tmr_cmd_cnt = cmd_cnt;
1276
1277         if (cmd_cnt != 0) {
1278                 cmd_cnt = 0;
1279                 list_for_each_entry(se_cmd, cmd_list, state_list) {
1280                         if (!se_cmd->priv)
1281                                 continue;
1282                         cmd = se_cmd->priv;
1283                         if (cmd->cmd_id)
1284                                 tmr->tmr_cmd_ids[cmd_cnt++] = cmd->cmd_id;
1285                 }
1286         }
1287
1288         queue_tmr_ring(udev, tmr);
1289
1290 unlock:
1291         mutex_unlock(&udev->cmdr_lock);
1292 }
1293
1294 static void tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry *entry)
1295 {
1296         struct se_cmd *se_cmd = cmd->se_cmd;
1297         struct tcmu_dev *udev = cmd->tcmu_dev;
1298         bool read_len_valid = false;
1299         uint32_t read_len;
1300
1301         /*
1302          * cmd has been completed already from timeout, just reclaim
1303          * data area space and free cmd
1304          */
1305         if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
1306                 WARN_ON_ONCE(se_cmd);
1307                 goto out;
1308         }
1309
1310         list_del_init(&cmd->queue_entry);
1311
1312         tcmu_cmd_reset_dbi_cur(cmd);
1313
1314         if (entry->hdr.uflags & TCMU_UFLAG_UNKNOWN_OP) {
1315                 pr_warn("TCMU: Userspace set UNKNOWN_OP flag on se_cmd %p\n",
1316                         cmd->se_cmd);
1317                 entry->rsp.scsi_status = SAM_STAT_CHECK_CONDITION;
1318                 goto done;
1319         }
1320
1321         read_len = se_cmd->data_length;
1322         if (se_cmd->data_direction == DMA_FROM_DEVICE &&
1323             (entry->hdr.uflags & TCMU_UFLAG_READ_LEN) && entry->rsp.read_len) {
1324                 read_len_valid = true;
1325                 if (entry->rsp.read_len < read_len)
1326                         read_len = entry->rsp.read_len;
1327         }
1328
1329         if (entry->rsp.scsi_status == SAM_STAT_CHECK_CONDITION) {
1330                 transport_copy_sense_to_cmd(se_cmd, entry->rsp.sense_buffer);
1331                 if (!read_len_valid )
1332                         goto done;
1333                 else
1334                         se_cmd->se_cmd_flags |= SCF_TREAT_READ_AS_NORMAL;
1335         }
1336         if (se_cmd->se_cmd_flags & SCF_BIDI) {
1337                 /* Get Data-In buffer before clean up */
1338                 gather_data_area(udev, cmd, true, read_len);
1339         } else if (se_cmd->data_direction == DMA_FROM_DEVICE) {
1340                 gather_data_area(udev, cmd, false, read_len);
1341         } else if (se_cmd->data_direction == DMA_TO_DEVICE) {
1342                 /* TODO: */
1343         } else if (se_cmd->data_direction != DMA_NONE) {
1344                 pr_warn("TCMU: data direction was %d!\n",
1345                         se_cmd->data_direction);
1346         }
1347
1348 done:
1349         if (read_len_valid) {
1350                 pr_debug("read_len = %d\n", read_len);
1351                 target_complete_cmd_with_length(cmd->se_cmd,
1352                                         entry->rsp.scsi_status, read_len);
1353         } else
1354                 target_complete_cmd(cmd->se_cmd, entry->rsp.scsi_status);
1355
1356 out:
1357         tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
1358         tcmu_free_cmd(cmd);
1359 }
1360
1361 static int tcmu_run_tmr_queue(struct tcmu_dev *udev)
1362 {
1363         struct tcmu_tmr *tmr, *tmp;
1364         LIST_HEAD(tmrs);
1365
1366         if (list_empty(&udev->tmr_queue))
1367                 return 1;
1368
1369         pr_debug("running %s's tmr queue\n", udev->name);
1370
1371         list_splice_init(&udev->tmr_queue, &tmrs);
1372
1373         list_for_each_entry_safe(tmr, tmp, &tmrs, queue_entry) {
1374                 list_del_init(&tmr->queue_entry);
1375
1376                 pr_debug("removing tmr %p on dev %s from queue\n",
1377                          tmr, udev->name);
1378
1379                 if (queue_tmr_ring(udev, tmr)) {
1380                         pr_debug("ran out of space during tmr queue run\n");
1381                         /*
1382                          * tmr was requeued, so just put all tmrs back in
1383                          * the queue
1384                          */
1385                         list_splice_tail(&tmrs, &udev->tmr_queue);
1386                         return 0;
1387                 }
1388         }
1389
1390         return 1;
1391 }
1392
1393 static unsigned int tcmu_handle_completions(struct tcmu_dev *udev)
1394 {
1395         struct tcmu_mailbox *mb;
1396         struct tcmu_cmd *cmd;
1397         bool free_space = false;
1398
1399         if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
1400                 pr_err("ring broken, not handling completions\n");
1401                 return 0;
1402         }
1403
1404         mb = udev->mb_addr;
1405         tcmu_flush_dcache_range(mb, sizeof(*mb));
1406
1407         while (udev->cmdr_last_cleaned != READ_ONCE(mb->cmd_tail)) {
1408
1409                 struct tcmu_cmd_entry *entry = (void *) mb + CMDR_OFF + udev->cmdr_last_cleaned;
1410
1411                 /*
1412                  * Flush max. up to end of cmd ring since current entry might
1413                  * be a padding that is shorter than sizeof(*entry)
1414                  */
1415                 size_t ring_left = head_to_end(udev->cmdr_last_cleaned,
1416                                                udev->cmdr_size);
1417                 tcmu_flush_dcache_range(entry, ring_left < sizeof(*entry) ?
1418                                         ring_left : sizeof(*entry));
1419
1420                 free_space = true;
1421
1422                 if (tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_PAD ||
1423                     tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_TMR) {
1424                         UPDATE_HEAD(udev->cmdr_last_cleaned,
1425                                     tcmu_hdr_get_len(entry->hdr.len_op),
1426                                     udev->cmdr_size);
1427                         continue;
1428                 }
1429                 WARN_ON(tcmu_hdr_get_op(entry->hdr.len_op) != TCMU_OP_CMD);
1430
1431                 cmd = idr_remove(&udev->commands, entry->hdr.cmd_id);
1432                 if (!cmd) {
1433                         pr_err("cmd_id %u not found, ring is broken\n",
1434                                entry->hdr.cmd_id);
1435                         set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
1436                         break;
1437                 }
1438
1439                 tcmu_handle_completion(cmd, entry);
1440
1441                 UPDATE_HEAD(udev->cmdr_last_cleaned,
1442                             tcmu_hdr_get_len(entry->hdr.len_op),
1443                             udev->cmdr_size);
1444         }
1445         if (free_space)
1446                 free_space = tcmu_run_tmr_queue(udev);
1447
1448         if (atomic_read(&global_db_count) > tcmu_global_max_blocks &&
1449             idr_is_empty(&udev->commands) && list_empty(&udev->qfull_queue)) {
1450                 /*
1451                  * Allocated blocks exceeded global block limit, currently no
1452                  * more pending or waiting commands so try to reclaim blocks.
1453                  */
1454                 schedule_delayed_work(&tcmu_unmap_work, 0);
1455         }
1456         if (udev->cmd_time_out)
1457                 tcmu_set_next_deadline(&udev->inflight_queue, &udev->cmd_timer);
1458
1459         return free_space;
1460 }
1461
1462 static void tcmu_check_expired_ring_cmd(struct tcmu_cmd *cmd)
1463 {
1464         struct se_cmd *se_cmd;
1465
1466         if (!time_after_eq(jiffies, cmd->deadline))
1467                 return;
1468
1469         set_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags);
1470         list_del_init(&cmd->queue_entry);
1471         se_cmd = cmd->se_cmd;
1472         se_cmd->priv = NULL;
1473         cmd->se_cmd = NULL;
1474
1475         pr_debug("Timing out inflight cmd %u on dev %s.\n",
1476                  cmd->cmd_id, cmd->tcmu_dev->name);
1477
1478         target_complete_cmd(se_cmd, SAM_STAT_CHECK_CONDITION);
1479 }
1480
1481 static void tcmu_check_expired_queue_cmd(struct tcmu_cmd *cmd)
1482 {
1483         struct se_cmd *se_cmd;
1484
1485         if (!time_after_eq(jiffies, cmd->deadline))
1486                 return;
1487
1488         pr_debug("Timing out queued cmd %p on dev %s.\n",
1489                   cmd, cmd->tcmu_dev->name);
1490
1491         list_del_init(&cmd->queue_entry);
1492         se_cmd = cmd->se_cmd;
1493         tcmu_free_cmd(cmd);
1494
1495         target_complete_cmd(se_cmd, SAM_STAT_TASK_SET_FULL);
1496 }
1497
1498 static void tcmu_device_timedout(struct tcmu_dev *udev)
1499 {
1500         spin_lock(&timed_out_udevs_lock);
1501         if (list_empty(&udev->timedout_entry))
1502                 list_add_tail(&udev->timedout_entry, &timed_out_udevs);
1503         spin_unlock(&timed_out_udevs_lock);
1504
1505         schedule_delayed_work(&tcmu_unmap_work, 0);
1506 }
1507
1508 static void tcmu_cmd_timedout(struct timer_list *t)
1509 {
1510         struct tcmu_dev *udev = from_timer(udev, t, cmd_timer);
1511
1512         pr_debug("%s cmd timeout has expired\n", udev->name);
1513         tcmu_device_timedout(udev);
1514 }
1515
1516 static void tcmu_qfull_timedout(struct timer_list *t)
1517 {
1518         struct tcmu_dev *udev = from_timer(udev, t, qfull_timer);
1519
1520         pr_debug("%s qfull timeout has expired\n", udev->name);
1521         tcmu_device_timedout(udev);
1522 }
1523
1524 static int tcmu_attach_hba(struct se_hba *hba, u32 host_id)
1525 {
1526         struct tcmu_hba *tcmu_hba;
1527
1528         tcmu_hba = kzalloc(sizeof(struct tcmu_hba), GFP_KERNEL);
1529         if (!tcmu_hba)
1530                 return -ENOMEM;
1531
1532         tcmu_hba->host_id = host_id;
1533         hba->hba_ptr = tcmu_hba;
1534
1535         return 0;
1536 }
1537
1538 static void tcmu_detach_hba(struct se_hba *hba)
1539 {
1540         kfree(hba->hba_ptr);
1541         hba->hba_ptr = NULL;
1542 }
1543
1544 static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name)
1545 {
1546         struct tcmu_dev *udev;
1547
1548         udev = kzalloc(sizeof(struct tcmu_dev), GFP_KERNEL);
1549         if (!udev)
1550                 return NULL;
1551         kref_init(&udev->kref);
1552
1553         udev->name = kstrdup(name, GFP_KERNEL);
1554         if (!udev->name) {
1555                 kfree(udev);
1556                 return NULL;
1557         }
1558
1559         udev->hba = hba;
1560         udev->cmd_time_out = TCMU_TIME_OUT;
1561         udev->qfull_time_out = -1;
1562
1563         udev->max_blocks = DATA_BLOCK_BITS_DEF;
1564         mutex_init(&udev->cmdr_lock);
1565
1566         INIT_LIST_HEAD(&udev->node);
1567         INIT_LIST_HEAD(&udev->timedout_entry);
1568         INIT_LIST_HEAD(&udev->qfull_queue);
1569         INIT_LIST_HEAD(&udev->tmr_queue);
1570         INIT_LIST_HEAD(&udev->inflight_queue);
1571         idr_init(&udev->commands);
1572
1573         timer_setup(&udev->qfull_timer, tcmu_qfull_timedout, 0);
1574         timer_setup(&udev->cmd_timer, tcmu_cmd_timedout, 0);
1575
1576         INIT_RADIX_TREE(&udev->data_blocks, GFP_KERNEL);
1577
1578         return &udev->se_dev;
1579 }
1580
1581 static void run_qfull_queue(struct tcmu_dev *udev, bool fail)
1582 {
1583         struct tcmu_cmd *tcmu_cmd, *tmp_cmd;
1584         LIST_HEAD(cmds);
1585         sense_reason_t scsi_ret;
1586         int ret;
1587
1588         if (list_empty(&udev->qfull_queue))
1589                 return;
1590
1591         pr_debug("running %s's cmdr queue forcefail %d\n", udev->name, fail);
1592
1593         list_splice_init(&udev->qfull_queue, &cmds);
1594
1595         list_for_each_entry_safe(tcmu_cmd, tmp_cmd, &cmds, queue_entry) {
1596                 list_del_init(&tcmu_cmd->queue_entry);
1597
1598                 pr_debug("removing cmd %p on dev %s from queue\n",
1599                          tcmu_cmd, udev->name);
1600
1601                 if (fail) {
1602                         /*
1603                          * We were not able to even start the command, so
1604                          * fail with busy to allow a retry in case runner
1605                          * was only temporarily down. If the device is being
1606                          * removed then LIO core will do the right thing and
1607                          * fail the retry.
1608                          */
1609                         target_complete_cmd(tcmu_cmd->se_cmd, SAM_STAT_BUSY);
1610                         tcmu_free_cmd(tcmu_cmd);
1611                         continue;
1612                 }
1613
1614                 ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
1615                 if (ret < 0) {
1616                         pr_debug("cmd %p on dev %s failed with %u\n",
1617                                  tcmu_cmd, udev->name, scsi_ret);
1618                         /*
1619                          * Ignore scsi_ret for now. target_complete_cmd
1620                          * drops it.
1621                          */
1622                         target_complete_cmd(tcmu_cmd->se_cmd,
1623                                             SAM_STAT_CHECK_CONDITION);
1624                         tcmu_free_cmd(tcmu_cmd);
1625                 } else if (ret > 0) {
1626                         pr_debug("ran out of space during cmdr queue run\n");
1627                         /*
1628                          * cmd was requeued, so just put all cmds back in
1629                          * the queue
1630                          */
1631                         list_splice_tail(&cmds, &udev->qfull_queue);
1632                         break;
1633                 }
1634         }
1635
1636         tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
1637 }
1638
1639 static int tcmu_irqcontrol(struct uio_info *info, s32 irq_on)
1640 {
1641         struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1642
1643         mutex_lock(&udev->cmdr_lock);
1644         if (tcmu_handle_completions(udev))
1645                 run_qfull_queue(udev, false);
1646         mutex_unlock(&udev->cmdr_lock);
1647
1648         return 0;
1649 }
1650
1651 /*
1652  * mmap code from uio.c. Copied here because we want to hook mmap()
1653  * and this stuff must come along.
1654  */
1655 static int tcmu_find_mem_index(struct vm_area_struct *vma)
1656 {
1657         struct tcmu_dev *udev = vma->vm_private_data;
1658         struct uio_info *info = &udev->uio_info;
1659
1660         if (vma->vm_pgoff < MAX_UIO_MAPS) {
1661                 if (info->mem[vma->vm_pgoff].size == 0)
1662                         return -1;
1663                 return (int)vma->vm_pgoff;
1664         }
1665         return -1;
1666 }
1667
1668 static struct page *tcmu_try_get_block_page(struct tcmu_dev *udev, uint32_t dbi)
1669 {
1670         struct page *page;
1671
1672         mutex_lock(&udev->cmdr_lock);
1673         page = tcmu_get_block_page(udev, dbi);
1674         if (likely(page)) {
1675                 mutex_unlock(&udev->cmdr_lock);
1676                 return page;
1677         }
1678
1679         /*
1680          * Userspace messed up and passed in a address not in the
1681          * data iov passed to it.
1682          */
1683         pr_err("Invalid addr to data block mapping  (dbi %u) on device %s\n",
1684                dbi, udev->name);
1685         page = NULL;
1686         mutex_unlock(&udev->cmdr_lock);
1687
1688         return page;
1689 }
1690
1691 static vm_fault_t tcmu_vma_fault(struct vm_fault *vmf)
1692 {
1693         struct tcmu_dev *udev = vmf->vma->vm_private_data;
1694         struct uio_info *info = &udev->uio_info;
1695         struct page *page;
1696         unsigned long offset;
1697         void *addr;
1698
1699         int mi = tcmu_find_mem_index(vmf->vma);
1700         if (mi < 0)
1701                 return VM_FAULT_SIGBUS;
1702
1703         /*
1704          * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
1705          * to use mem[N].
1706          */
1707         offset = (vmf->pgoff - mi) << PAGE_SHIFT;
1708
1709         if (offset < udev->data_off) {
1710                 /* For the vmalloc()ed cmd area pages */
1711                 addr = (void *)(unsigned long)info->mem[mi].addr + offset;
1712                 page = vmalloc_to_page(addr);
1713         } else {
1714                 uint32_t dbi;
1715
1716                 /* For the dynamically growing data area pages */
1717                 dbi = (offset - udev->data_off) / DATA_BLOCK_SIZE;
1718                 page = tcmu_try_get_block_page(udev, dbi);
1719                 if (!page)
1720                         return VM_FAULT_SIGBUS;
1721         }
1722
1723         get_page(page);
1724         vmf->page = page;
1725         return 0;
1726 }
1727
1728 static const struct vm_operations_struct tcmu_vm_ops = {
1729         .fault = tcmu_vma_fault,
1730 };
1731
1732 static int tcmu_mmap(struct uio_info *info, struct vm_area_struct *vma)
1733 {
1734         struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1735
1736         vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
1737         vma->vm_ops = &tcmu_vm_ops;
1738
1739         vma->vm_private_data = udev;
1740
1741         /* Ensure the mmap is exactly the right size */
1742         if (vma_pages(vma) != (udev->ring_size >> PAGE_SHIFT))
1743                 return -EINVAL;
1744
1745         return 0;
1746 }
1747
1748 static int tcmu_open(struct uio_info *info, struct inode *inode)
1749 {
1750         struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1751
1752         /* O_EXCL not supported for char devs, so fake it? */
1753         if (test_and_set_bit(TCMU_DEV_BIT_OPEN, &udev->flags))
1754                 return -EBUSY;
1755
1756         udev->inode = inode;
1757         kref_get(&udev->kref);
1758
1759         pr_debug("open\n");
1760
1761         return 0;
1762 }
1763
1764 static void tcmu_dev_call_rcu(struct rcu_head *p)
1765 {
1766         struct se_device *dev = container_of(p, struct se_device, rcu_head);
1767         struct tcmu_dev *udev = TCMU_DEV(dev);
1768
1769         kfree(udev->uio_info.name);
1770         kfree(udev->name);
1771         kfree(udev);
1772 }
1773
1774 static int tcmu_check_and_free_pending_cmd(struct tcmu_cmd *cmd)
1775 {
1776         if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
1777                 kmem_cache_free(tcmu_cmd_cache, cmd);
1778                 return 0;
1779         }
1780         return -EINVAL;
1781 }
1782
1783 static void tcmu_blocks_release(struct radix_tree_root *blocks,
1784                                 int start, int end)
1785 {
1786         int i;
1787         struct page *page;
1788
1789         for (i = start; i < end; i++) {
1790                 page = radix_tree_delete(blocks, i);
1791                 if (page) {
1792                         __free_page(page);
1793                         atomic_dec(&global_db_count);
1794                 }
1795         }
1796 }
1797
1798 static void tcmu_remove_all_queued_tmr(struct tcmu_dev *udev)
1799 {
1800         struct tcmu_tmr *tmr, *tmp;
1801
1802         list_for_each_entry_safe(tmr, tmp, &udev->tmr_queue, queue_entry) {
1803                 list_del_init(&tmr->queue_entry);
1804                 kfree(tmr);
1805         }
1806 }
1807
1808 static void tcmu_dev_kref_release(struct kref *kref)
1809 {
1810         struct tcmu_dev *udev = container_of(kref, struct tcmu_dev, kref);
1811         struct se_device *dev = &udev->se_dev;
1812         struct tcmu_cmd *cmd;
1813         bool all_expired = true;
1814         int i;
1815
1816         vfree(udev->mb_addr);
1817         udev->mb_addr = NULL;
1818
1819         spin_lock_bh(&timed_out_udevs_lock);
1820         if (!list_empty(&udev->timedout_entry))
1821                 list_del(&udev->timedout_entry);
1822         spin_unlock_bh(&timed_out_udevs_lock);
1823
1824         /* Upper layer should drain all requests before calling this */
1825         mutex_lock(&udev->cmdr_lock);
1826         idr_for_each_entry(&udev->commands, cmd, i) {
1827                 if (tcmu_check_and_free_pending_cmd(cmd) != 0)
1828                         all_expired = false;
1829         }
1830         /* There can be left over TMR cmds. Remove them. */
1831         tcmu_remove_all_queued_tmr(udev);
1832         if (!list_empty(&udev->qfull_queue))
1833                 all_expired = false;
1834         idr_destroy(&udev->commands);
1835         WARN_ON(!all_expired);
1836
1837         tcmu_blocks_release(&udev->data_blocks, 0, udev->dbi_max + 1);
1838         bitmap_free(udev->data_bitmap);
1839         mutex_unlock(&udev->cmdr_lock);
1840
1841         call_rcu(&dev->rcu_head, tcmu_dev_call_rcu);
1842 }
1843
1844 static int tcmu_release(struct uio_info *info, struct inode *inode)
1845 {
1846         struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1847
1848         clear_bit(TCMU_DEV_BIT_OPEN, &udev->flags);
1849
1850         pr_debug("close\n");
1851         /* release ref from open */
1852         kref_put(&udev->kref, tcmu_dev_kref_release);
1853         return 0;
1854 }
1855
1856 static int tcmu_init_genl_cmd_reply(struct tcmu_dev *udev, int cmd)
1857 {
1858         struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
1859
1860         if (!tcmu_kern_cmd_reply_supported)
1861                 return 0;
1862
1863         if (udev->nl_reply_supported <= 0)
1864                 return 0;
1865
1866         mutex_lock(&tcmu_nl_cmd_mutex);
1867
1868         if (tcmu_netlink_blocked) {
1869                 mutex_unlock(&tcmu_nl_cmd_mutex);
1870                 pr_warn("Failing nl cmd %d on %s. Interface is blocked.\n", cmd,
1871                         udev->name);
1872                 return -EAGAIN;
1873         }
1874
1875         if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
1876                 mutex_unlock(&tcmu_nl_cmd_mutex);
1877                 pr_warn("netlink cmd %d already executing on %s\n",
1878                          nl_cmd->cmd, udev->name);
1879                 return -EBUSY;
1880         }
1881
1882         memset(nl_cmd, 0, sizeof(*nl_cmd));
1883         nl_cmd->cmd = cmd;
1884         nl_cmd->udev = udev;
1885         init_completion(&nl_cmd->complete);
1886         INIT_LIST_HEAD(&nl_cmd->nl_list);
1887
1888         list_add_tail(&nl_cmd->nl_list, &tcmu_nl_cmd_list);
1889
1890         mutex_unlock(&tcmu_nl_cmd_mutex);
1891         return 0;
1892 }
1893
1894 static void tcmu_destroy_genl_cmd_reply(struct tcmu_dev *udev)
1895 {
1896         struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
1897
1898         if (!tcmu_kern_cmd_reply_supported)
1899                 return;
1900
1901         if (udev->nl_reply_supported <= 0)
1902                 return;
1903
1904         mutex_lock(&tcmu_nl_cmd_mutex);
1905
1906         list_del(&nl_cmd->nl_list);
1907         memset(nl_cmd, 0, sizeof(*nl_cmd));
1908
1909         mutex_unlock(&tcmu_nl_cmd_mutex);
1910 }
1911
1912 static int tcmu_wait_genl_cmd_reply(struct tcmu_dev *udev)
1913 {
1914         struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
1915         int ret;
1916
1917         if (!tcmu_kern_cmd_reply_supported)
1918                 return 0;
1919
1920         if (udev->nl_reply_supported <= 0)
1921                 return 0;
1922
1923         pr_debug("sleeping for nl reply\n");
1924         wait_for_completion(&nl_cmd->complete);
1925
1926         mutex_lock(&tcmu_nl_cmd_mutex);
1927         nl_cmd->cmd = TCMU_CMD_UNSPEC;
1928         ret = nl_cmd->status;
1929         mutex_unlock(&tcmu_nl_cmd_mutex);
1930
1931         return ret;
1932 }
1933
1934 static int tcmu_netlink_event_init(struct tcmu_dev *udev,
1935                                    enum tcmu_genl_cmd cmd,
1936                                    struct sk_buff **buf, void **hdr)
1937 {
1938         struct sk_buff *skb;
1939         void *msg_header;
1940         int ret = -ENOMEM;
1941
1942         skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
1943         if (!skb)
1944                 return ret;
1945
1946         msg_header = genlmsg_put(skb, 0, 0, &tcmu_genl_family, 0, cmd);
1947         if (!msg_header)
1948                 goto free_skb;
1949
1950         ret = nla_put_string(skb, TCMU_ATTR_DEVICE, udev->uio_info.name);
1951         if (ret < 0)
1952                 goto free_skb;
1953
1954         ret = nla_put_u32(skb, TCMU_ATTR_MINOR, udev->uio_info.uio_dev->minor);
1955         if (ret < 0)
1956                 goto free_skb;
1957
1958         ret = nla_put_u32(skb, TCMU_ATTR_DEVICE_ID, udev->se_dev.dev_index);
1959         if (ret < 0)
1960                 goto free_skb;
1961
1962         *buf = skb;
1963         *hdr = msg_header;
1964         return ret;
1965
1966 free_skb:
1967         nlmsg_free(skb);
1968         return ret;
1969 }
1970
1971 static int tcmu_netlink_event_send(struct tcmu_dev *udev,
1972                                    enum tcmu_genl_cmd cmd,
1973                                    struct sk_buff *skb, void *msg_header)
1974 {
1975         int ret;
1976
1977         genlmsg_end(skb, msg_header);
1978
1979         ret = tcmu_init_genl_cmd_reply(udev, cmd);
1980         if (ret) {
1981                 nlmsg_free(skb);
1982                 return ret;
1983         }
1984
1985         ret = genlmsg_multicast_allns(&tcmu_genl_family, skb, 0,
1986                                       TCMU_MCGRP_CONFIG, GFP_KERNEL);
1987
1988         /* Wait during an add as the listener may not be up yet */
1989         if (ret == 0 ||
1990            (ret == -ESRCH && cmd == TCMU_CMD_ADDED_DEVICE))
1991                 return tcmu_wait_genl_cmd_reply(udev);
1992         else
1993                 tcmu_destroy_genl_cmd_reply(udev);
1994
1995         return ret;
1996 }
1997
1998 static int tcmu_send_dev_add_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_ADDED_DEVICE, &skb,
2005                                       &msg_header);
2006         if (ret < 0)
2007                 return ret;
2008         return tcmu_netlink_event_send(udev, TCMU_CMD_ADDED_DEVICE, skb,
2009                                        msg_header);
2010 }
2011
2012 static int tcmu_send_dev_remove_event(struct tcmu_dev *udev)
2013 {
2014         struct sk_buff *skb = NULL;
2015         void *msg_header = NULL;
2016         int ret = 0;
2017
2018         ret = tcmu_netlink_event_init(udev, TCMU_CMD_REMOVED_DEVICE,
2019                                       &skb, &msg_header);
2020         if (ret < 0)
2021                 return ret;
2022         return tcmu_netlink_event_send(udev, TCMU_CMD_REMOVED_DEVICE,
2023                                        skb, msg_header);
2024 }
2025
2026 static int tcmu_update_uio_info(struct tcmu_dev *udev)
2027 {
2028         struct tcmu_hba *hba = udev->hba->hba_ptr;
2029         struct uio_info *info;
2030         char *str;
2031
2032         info = &udev->uio_info;
2033
2034         if (udev->dev_config[0])
2035                 str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s/%s", hba->host_id,
2036                                 udev->name, udev->dev_config);
2037         else
2038                 str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s", hba->host_id,
2039                                 udev->name);
2040         if (!str)
2041                 return -ENOMEM;
2042
2043         /* If the old string exists, free it */
2044         kfree(info->name);
2045         info->name = str;
2046
2047         return 0;
2048 }
2049
2050 static int tcmu_configure_device(struct se_device *dev)
2051 {
2052         struct tcmu_dev *udev = TCMU_DEV(dev);
2053         struct uio_info *info;
2054         struct tcmu_mailbox *mb;
2055         int ret = 0;
2056
2057         ret = tcmu_update_uio_info(udev);
2058         if (ret)
2059                 return ret;
2060
2061         info = &udev->uio_info;
2062
2063         mutex_lock(&udev->cmdr_lock);
2064         udev->data_bitmap = bitmap_zalloc(udev->max_blocks, GFP_KERNEL);
2065         mutex_unlock(&udev->cmdr_lock);
2066         if (!udev->data_bitmap) {
2067                 ret = -ENOMEM;
2068                 goto err_bitmap_alloc;
2069         }
2070
2071         udev->mb_addr = vzalloc(CMDR_SIZE);
2072         if (!udev->mb_addr) {
2073                 ret = -ENOMEM;
2074                 goto err_vzalloc;
2075         }
2076
2077         /* mailbox fits in first part of CMDR space */
2078         udev->cmdr_size = CMDR_SIZE - CMDR_OFF;
2079         udev->data_off = CMDR_SIZE;
2080         udev->data_size = udev->max_blocks * DATA_BLOCK_SIZE;
2081         udev->dbi_thresh = 0; /* Default in Idle state */
2082
2083         /* Initialise the mailbox of the ring buffer */
2084         mb = udev->mb_addr;
2085         mb->version = TCMU_MAILBOX_VERSION;
2086         mb->flags = TCMU_MAILBOX_FLAG_CAP_OOOC |
2087                     TCMU_MAILBOX_FLAG_CAP_READ_LEN |
2088                     TCMU_MAILBOX_FLAG_CAP_TMR;
2089         mb->cmdr_off = CMDR_OFF;
2090         mb->cmdr_size = udev->cmdr_size;
2091
2092         WARN_ON(!PAGE_ALIGNED(udev->data_off));
2093         WARN_ON(udev->data_size % PAGE_SIZE);
2094         WARN_ON(udev->data_size % DATA_BLOCK_SIZE);
2095
2096         info->version = __stringify(TCMU_MAILBOX_VERSION);
2097
2098         info->mem[0].name = "tcm-user command & data buffer";
2099         info->mem[0].addr = (phys_addr_t)(uintptr_t)udev->mb_addr;
2100         info->mem[0].size = udev->ring_size = udev->data_size + CMDR_SIZE;
2101         info->mem[0].memtype = UIO_MEM_NONE;
2102
2103         info->irqcontrol = tcmu_irqcontrol;
2104         info->irq = UIO_IRQ_CUSTOM;
2105
2106         info->mmap = tcmu_mmap;
2107         info->open = tcmu_open;
2108         info->release = tcmu_release;
2109
2110         ret = uio_register_device(tcmu_root_device, info);
2111         if (ret)
2112                 goto err_register;
2113
2114         /* User can set hw_block_size before enable the device */
2115         if (dev->dev_attrib.hw_block_size == 0)
2116                 dev->dev_attrib.hw_block_size = 512;
2117         /* Other attributes can be configured in userspace */
2118         if (!dev->dev_attrib.hw_max_sectors)
2119                 dev->dev_attrib.hw_max_sectors = 128;
2120         if (!dev->dev_attrib.emulate_write_cache)
2121                 dev->dev_attrib.emulate_write_cache = 0;
2122         dev->dev_attrib.hw_queue_depth = 128;
2123
2124         /* If user didn't explicitly disable netlink reply support, use
2125          * module scope setting.
2126          */
2127         if (udev->nl_reply_supported >= 0)
2128                 udev->nl_reply_supported = tcmu_kern_cmd_reply_supported;
2129
2130         /*
2131          * Get a ref incase userspace does a close on the uio device before
2132          * LIO has initiated tcmu_free_device.
2133          */
2134         kref_get(&udev->kref);
2135
2136         ret = tcmu_send_dev_add_event(udev);
2137         if (ret)
2138                 goto err_netlink;
2139
2140         mutex_lock(&root_udev_mutex);
2141         list_add(&udev->node, &root_udev);
2142         mutex_unlock(&root_udev_mutex);
2143
2144         return 0;
2145
2146 err_netlink:
2147         kref_put(&udev->kref, tcmu_dev_kref_release);
2148         uio_unregister_device(&udev->uio_info);
2149 err_register:
2150         vfree(udev->mb_addr);
2151         udev->mb_addr = NULL;
2152 err_vzalloc:
2153         bitmap_free(udev->data_bitmap);
2154         udev->data_bitmap = NULL;
2155 err_bitmap_alloc:
2156         kfree(info->name);
2157         info->name = NULL;
2158
2159         return ret;
2160 }
2161
2162 static void tcmu_free_device(struct se_device *dev)
2163 {
2164         struct tcmu_dev *udev = TCMU_DEV(dev);
2165
2166         /* release ref from init */
2167         kref_put(&udev->kref, tcmu_dev_kref_release);
2168 }
2169
2170 static void tcmu_destroy_device(struct se_device *dev)
2171 {
2172         struct tcmu_dev *udev = TCMU_DEV(dev);
2173
2174         del_timer_sync(&udev->cmd_timer);
2175         del_timer_sync(&udev->qfull_timer);
2176
2177         mutex_lock(&root_udev_mutex);
2178         list_del(&udev->node);
2179         mutex_unlock(&root_udev_mutex);
2180
2181         tcmu_send_dev_remove_event(udev);
2182
2183         uio_unregister_device(&udev->uio_info);
2184
2185         /* release ref from configure */
2186         kref_put(&udev->kref, tcmu_dev_kref_release);
2187 }
2188
2189 static void tcmu_unblock_dev(struct tcmu_dev *udev)
2190 {
2191         mutex_lock(&udev->cmdr_lock);
2192         clear_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags);
2193         mutex_unlock(&udev->cmdr_lock);
2194 }
2195
2196 static void tcmu_block_dev(struct tcmu_dev *udev)
2197 {
2198         mutex_lock(&udev->cmdr_lock);
2199
2200         if (test_and_set_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
2201                 goto unlock;
2202
2203         /* complete IO that has executed successfully */
2204         tcmu_handle_completions(udev);
2205         /* fail IO waiting to be queued */
2206         run_qfull_queue(udev, true);
2207
2208 unlock:
2209         mutex_unlock(&udev->cmdr_lock);
2210 }
2211
2212 static void tcmu_reset_ring(struct tcmu_dev *udev, u8 err_level)
2213 {
2214         struct tcmu_mailbox *mb;
2215         struct tcmu_cmd *cmd;
2216         int i;
2217
2218         mutex_lock(&udev->cmdr_lock);
2219
2220         idr_for_each_entry(&udev->commands, cmd, i) {
2221                 pr_debug("removing cmd %u on dev %s from ring (is expired %d)\n",
2222                           cmd->cmd_id, udev->name,
2223                           test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags));
2224
2225                 idr_remove(&udev->commands, i);
2226                 if (!test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
2227                         WARN_ON(!cmd->se_cmd);
2228                         list_del_init(&cmd->queue_entry);
2229                         if (err_level == 1) {
2230                                 /*
2231                                  * Userspace was not able to start the
2232                                  * command or it is retryable.
2233                                  */
2234                                 target_complete_cmd(cmd->se_cmd, SAM_STAT_BUSY);
2235                         } else {
2236                                 /* hard failure */
2237                                 target_complete_cmd(cmd->se_cmd,
2238                                                     SAM_STAT_CHECK_CONDITION);
2239                         }
2240                 }
2241                 tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
2242                 tcmu_free_cmd(cmd);
2243         }
2244
2245         mb = udev->mb_addr;
2246         tcmu_flush_dcache_range(mb, sizeof(*mb));
2247         pr_debug("mb last %u head %u tail %u\n", udev->cmdr_last_cleaned,
2248                  mb->cmd_tail, mb->cmd_head);
2249
2250         udev->cmdr_last_cleaned = 0;
2251         mb->cmd_tail = 0;
2252         mb->cmd_head = 0;
2253         tcmu_flush_dcache_range(mb, sizeof(*mb));
2254         clear_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
2255
2256         del_timer(&udev->cmd_timer);
2257
2258         /*
2259          * ring is empty and qfull queue never contains aborted commands.
2260          * So TMRs in tmr queue do not contain relevant cmd_ids.
2261          * After a ring reset userspace should do a fresh start, so
2262          * even LUN RESET message is no longer relevant.
2263          * Therefore remove all TMRs from qfull queue
2264          */
2265         tcmu_remove_all_queued_tmr(udev);
2266
2267         run_qfull_queue(udev, false);
2268
2269         mutex_unlock(&udev->cmdr_lock);
2270 }
2271
2272 enum {
2273         Opt_dev_config, Opt_dev_size, Opt_hw_block_size, Opt_hw_max_sectors,
2274         Opt_nl_reply_supported, Opt_max_data_area_mb, Opt_err,
2275 };
2276
2277 static match_table_t tokens = {
2278         {Opt_dev_config, "dev_config=%s"},
2279         {Opt_dev_size, "dev_size=%s"},
2280         {Opt_hw_block_size, "hw_block_size=%d"},
2281         {Opt_hw_max_sectors, "hw_max_sectors=%d"},
2282         {Opt_nl_reply_supported, "nl_reply_supported=%d"},
2283         {Opt_max_data_area_mb, "max_data_area_mb=%d"},
2284         {Opt_err, NULL}
2285 };
2286
2287 static int tcmu_set_dev_attrib(substring_t *arg, u32 *dev_attrib)
2288 {
2289         int val, ret;
2290
2291         ret = match_int(arg, &val);
2292         if (ret < 0) {
2293                 pr_err("match_int() failed for dev attrib. Error %d.\n",
2294                        ret);
2295                 return ret;
2296         }
2297
2298         if (val <= 0) {
2299                 pr_err("Invalid dev attrib value %d. Must be greater than zero.\n",
2300                        val);
2301                 return -EINVAL;
2302         }
2303         *dev_attrib = val;
2304         return 0;
2305 }
2306
2307 static int tcmu_set_max_blocks_param(struct tcmu_dev *udev, substring_t *arg)
2308 {
2309         int val, ret;
2310
2311         ret = match_int(arg, &val);
2312         if (ret < 0) {
2313                 pr_err("match_int() failed for max_data_area_mb=. Error %d.\n",
2314                        ret);
2315                 return ret;
2316         }
2317
2318         if (val <= 0) {
2319                 pr_err("Invalid max_data_area %d.\n", val);
2320                 return -EINVAL;
2321         }
2322
2323         mutex_lock(&udev->cmdr_lock);
2324         if (udev->data_bitmap) {
2325                 pr_err("Cannot set max_data_area_mb after it has been enabled.\n");
2326                 ret = -EINVAL;
2327                 goto unlock;
2328         }
2329
2330         udev->max_blocks = TCMU_MBS_TO_BLOCKS(val);
2331         if (udev->max_blocks > tcmu_global_max_blocks) {
2332                 pr_err("%d is too large. Adjusting max_data_area_mb to global limit of %u\n",
2333                        val, TCMU_BLOCKS_TO_MBS(tcmu_global_max_blocks));
2334                 udev->max_blocks = tcmu_global_max_blocks;
2335         }
2336
2337 unlock:
2338         mutex_unlock(&udev->cmdr_lock);
2339         return ret;
2340 }
2341
2342 static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev,
2343                 const char *page, ssize_t count)
2344 {
2345         struct tcmu_dev *udev = TCMU_DEV(dev);
2346         char *orig, *ptr, *opts;
2347         substring_t args[MAX_OPT_ARGS];
2348         int ret = 0, token;
2349
2350         opts = kstrdup(page, GFP_KERNEL);
2351         if (!opts)
2352                 return -ENOMEM;
2353
2354         orig = opts;
2355
2356         while ((ptr = strsep(&opts, ",\n")) != NULL) {
2357                 if (!*ptr)
2358                         continue;
2359
2360                 token = match_token(ptr, tokens, args);
2361                 switch (token) {
2362                 case Opt_dev_config:
2363                         if (match_strlcpy(udev->dev_config, &args[0],
2364                                           TCMU_CONFIG_LEN) == 0) {
2365                                 ret = -EINVAL;
2366                                 break;
2367                         }
2368                         pr_debug("TCMU: Referencing Path: %s\n", udev->dev_config);
2369                         break;
2370                 case Opt_dev_size:
2371                         ret = match_u64(&args[0], &udev->dev_size);
2372                         if (ret < 0)
2373                                 pr_err("match_u64() failed for dev_size=. Error %d.\n",
2374                                        ret);
2375                         break;
2376                 case Opt_hw_block_size:
2377                         ret = tcmu_set_dev_attrib(&args[0],
2378                                         &(dev->dev_attrib.hw_block_size));
2379                         break;
2380                 case Opt_hw_max_sectors:
2381                         ret = tcmu_set_dev_attrib(&args[0],
2382                                         &(dev->dev_attrib.hw_max_sectors));
2383                         break;
2384                 case Opt_nl_reply_supported:
2385                         ret = match_int(&args[0], &udev->nl_reply_supported);
2386                         if (ret < 0)
2387                                 pr_err("match_int() failed for nl_reply_supported=. Error %d.\n",
2388                                        ret);
2389                         break;
2390                 case Opt_max_data_area_mb:
2391                         ret = tcmu_set_max_blocks_param(udev, &args[0]);
2392                         break;
2393                 default:
2394                         break;
2395                 }
2396
2397                 if (ret)
2398                         break;
2399         }
2400
2401         kfree(orig);
2402         return (!ret) ? count : ret;
2403 }
2404
2405 static ssize_t tcmu_show_configfs_dev_params(struct se_device *dev, char *b)
2406 {
2407         struct tcmu_dev *udev = TCMU_DEV(dev);
2408         ssize_t bl = 0;
2409
2410         bl = sprintf(b + bl, "Config: %s ",
2411                      udev->dev_config[0] ? udev->dev_config : "NULL");
2412         bl += sprintf(b + bl, "Size: %llu ", udev->dev_size);
2413         bl += sprintf(b + bl, "MaxDataAreaMB: %u\n",
2414                       TCMU_BLOCKS_TO_MBS(udev->max_blocks));
2415
2416         return bl;
2417 }
2418
2419 static sector_t tcmu_get_blocks(struct se_device *dev)
2420 {
2421         struct tcmu_dev *udev = TCMU_DEV(dev);
2422
2423         return div_u64(udev->dev_size - dev->dev_attrib.block_size,
2424                        dev->dev_attrib.block_size);
2425 }
2426
2427 static sense_reason_t
2428 tcmu_parse_cdb(struct se_cmd *cmd)
2429 {
2430         return passthrough_parse_cdb(cmd, tcmu_queue_cmd);
2431 }
2432
2433 static ssize_t tcmu_cmd_time_out_show(struct config_item *item, char *page)
2434 {
2435         struct se_dev_attrib *da = container_of(to_config_group(item),
2436                                         struct se_dev_attrib, da_group);
2437         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2438
2439         return snprintf(page, PAGE_SIZE, "%lu\n", udev->cmd_time_out / MSEC_PER_SEC);
2440 }
2441
2442 static ssize_t tcmu_cmd_time_out_store(struct config_item *item, const char *page,
2443                                        size_t count)
2444 {
2445         struct se_dev_attrib *da = container_of(to_config_group(item),
2446                                         struct se_dev_attrib, da_group);
2447         struct tcmu_dev *udev = container_of(da->da_dev,
2448                                         struct tcmu_dev, se_dev);
2449         u32 val;
2450         int ret;
2451
2452         if (da->da_dev->export_count) {
2453                 pr_err("Unable to set tcmu cmd_time_out while exports exist\n");
2454                 return -EINVAL;
2455         }
2456
2457         ret = kstrtou32(page, 0, &val);
2458         if (ret < 0)
2459                 return ret;
2460
2461         udev->cmd_time_out = val * MSEC_PER_SEC;
2462         return count;
2463 }
2464 CONFIGFS_ATTR(tcmu_, cmd_time_out);
2465
2466 static ssize_t tcmu_qfull_time_out_show(struct config_item *item, char *page)
2467 {
2468         struct se_dev_attrib *da = container_of(to_config_group(item),
2469                                                 struct se_dev_attrib, da_group);
2470         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2471
2472         return snprintf(page, PAGE_SIZE, "%ld\n", udev->qfull_time_out <= 0 ?
2473                         udev->qfull_time_out :
2474                         udev->qfull_time_out / MSEC_PER_SEC);
2475 }
2476
2477 static ssize_t tcmu_qfull_time_out_store(struct config_item *item,
2478                                          const char *page, size_t count)
2479 {
2480         struct se_dev_attrib *da = container_of(to_config_group(item),
2481                                         struct se_dev_attrib, da_group);
2482         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2483         s32 val;
2484         int ret;
2485
2486         ret = kstrtos32(page, 0, &val);
2487         if (ret < 0)
2488                 return ret;
2489
2490         if (val >= 0) {
2491                 udev->qfull_time_out = val * MSEC_PER_SEC;
2492         } else if (val == -1) {
2493                 udev->qfull_time_out = val;
2494         } else {
2495                 printk(KERN_ERR "Invalid qfull timeout value %d\n", val);
2496                 return -EINVAL;
2497         }
2498         return count;
2499 }
2500 CONFIGFS_ATTR(tcmu_, qfull_time_out);
2501
2502 static ssize_t tcmu_max_data_area_mb_show(struct config_item *item, char *page)
2503 {
2504         struct se_dev_attrib *da = container_of(to_config_group(item),
2505                                                 struct se_dev_attrib, da_group);
2506         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2507
2508         return snprintf(page, PAGE_SIZE, "%u\n",
2509                         TCMU_BLOCKS_TO_MBS(udev->max_blocks));
2510 }
2511 CONFIGFS_ATTR_RO(tcmu_, max_data_area_mb);
2512
2513 static ssize_t tcmu_dev_config_show(struct config_item *item, char *page)
2514 {
2515         struct se_dev_attrib *da = container_of(to_config_group(item),
2516                                                 struct se_dev_attrib, da_group);
2517         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2518
2519         return snprintf(page, PAGE_SIZE, "%s\n", udev->dev_config);
2520 }
2521
2522 static int tcmu_send_dev_config_event(struct tcmu_dev *udev,
2523                                       const char *reconfig_data)
2524 {
2525         struct sk_buff *skb = NULL;
2526         void *msg_header = NULL;
2527         int ret = 0;
2528
2529         ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2530                                       &skb, &msg_header);
2531         if (ret < 0)
2532                 return ret;
2533         ret = nla_put_string(skb, TCMU_ATTR_DEV_CFG, reconfig_data);
2534         if (ret < 0) {
2535                 nlmsg_free(skb);
2536                 return ret;
2537         }
2538         return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2539                                        skb, msg_header);
2540 }
2541
2542
2543 static ssize_t tcmu_dev_config_store(struct config_item *item, const char *page,
2544                                      size_t count)
2545 {
2546         struct se_dev_attrib *da = container_of(to_config_group(item),
2547                                                 struct se_dev_attrib, da_group);
2548         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2549         int ret, len;
2550
2551         len = strlen(page);
2552         if (!len || len > TCMU_CONFIG_LEN - 1)
2553                 return -EINVAL;
2554
2555         /* Check if device has been configured before */
2556         if (target_dev_configured(&udev->se_dev)) {
2557                 ret = tcmu_send_dev_config_event(udev, page);
2558                 if (ret) {
2559                         pr_err("Unable to reconfigure device\n");
2560                         return ret;
2561                 }
2562                 strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2563
2564                 ret = tcmu_update_uio_info(udev);
2565                 if (ret)
2566                         return ret;
2567                 return count;
2568         }
2569         strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2570
2571         return count;
2572 }
2573 CONFIGFS_ATTR(tcmu_, dev_config);
2574
2575 static ssize_t tcmu_dev_size_show(struct config_item *item, char *page)
2576 {
2577         struct se_dev_attrib *da = container_of(to_config_group(item),
2578                                                 struct se_dev_attrib, da_group);
2579         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2580
2581         return snprintf(page, PAGE_SIZE, "%llu\n", udev->dev_size);
2582 }
2583
2584 static int tcmu_send_dev_size_event(struct tcmu_dev *udev, u64 size)
2585 {
2586         struct sk_buff *skb = NULL;
2587         void *msg_header = NULL;
2588         int ret = 0;
2589
2590         ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2591                                       &skb, &msg_header);
2592         if (ret < 0)
2593                 return ret;
2594         ret = nla_put_u64_64bit(skb, TCMU_ATTR_DEV_SIZE,
2595                                 size, TCMU_ATTR_PAD);
2596         if (ret < 0) {
2597                 nlmsg_free(skb);
2598                 return ret;
2599         }
2600         return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2601                                        skb, msg_header);
2602 }
2603
2604 static ssize_t tcmu_dev_size_store(struct config_item *item, const char *page,
2605                                    size_t count)
2606 {
2607         struct se_dev_attrib *da = container_of(to_config_group(item),
2608                                                 struct se_dev_attrib, da_group);
2609         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2610         u64 val;
2611         int ret;
2612
2613         ret = kstrtou64(page, 0, &val);
2614         if (ret < 0)
2615                 return ret;
2616
2617         /* Check if device has been configured before */
2618         if (target_dev_configured(&udev->se_dev)) {
2619                 ret = tcmu_send_dev_size_event(udev, val);
2620                 if (ret) {
2621                         pr_err("Unable to reconfigure device\n");
2622                         return ret;
2623                 }
2624         }
2625         udev->dev_size = val;
2626         return count;
2627 }
2628 CONFIGFS_ATTR(tcmu_, dev_size);
2629
2630 static ssize_t tcmu_nl_reply_supported_show(struct config_item *item,
2631                 char *page)
2632 {
2633         struct se_dev_attrib *da = container_of(to_config_group(item),
2634                                                 struct se_dev_attrib, da_group);
2635         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2636
2637         return snprintf(page, PAGE_SIZE, "%d\n", udev->nl_reply_supported);
2638 }
2639
2640 static ssize_t tcmu_nl_reply_supported_store(struct config_item *item,
2641                 const char *page, size_t count)
2642 {
2643         struct se_dev_attrib *da = container_of(to_config_group(item),
2644                                                 struct se_dev_attrib, da_group);
2645         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2646         s8 val;
2647         int ret;
2648
2649         ret = kstrtos8(page, 0, &val);
2650         if (ret < 0)
2651                 return ret;
2652
2653         udev->nl_reply_supported = val;
2654         return count;
2655 }
2656 CONFIGFS_ATTR(tcmu_, nl_reply_supported);
2657
2658 static ssize_t tcmu_emulate_write_cache_show(struct config_item *item,
2659                                              char *page)
2660 {
2661         struct se_dev_attrib *da = container_of(to_config_group(item),
2662                                         struct se_dev_attrib, da_group);
2663
2664         return snprintf(page, PAGE_SIZE, "%i\n", da->emulate_write_cache);
2665 }
2666
2667 static int tcmu_send_emulate_write_cache(struct tcmu_dev *udev, u8 val)
2668 {
2669         struct sk_buff *skb = NULL;
2670         void *msg_header = NULL;
2671         int ret = 0;
2672
2673         ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2674                                       &skb, &msg_header);
2675         if (ret < 0)
2676                 return ret;
2677         ret = nla_put_u8(skb, TCMU_ATTR_WRITECACHE, val);
2678         if (ret < 0) {
2679                 nlmsg_free(skb);
2680                 return ret;
2681         }
2682         return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2683                                        skb, msg_header);
2684 }
2685
2686 static ssize_t tcmu_emulate_write_cache_store(struct config_item *item,
2687                                               const char *page, size_t count)
2688 {
2689         struct se_dev_attrib *da = container_of(to_config_group(item),
2690                                         struct se_dev_attrib, da_group);
2691         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2692         u8 val;
2693         int ret;
2694
2695         ret = kstrtou8(page, 0, &val);
2696         if (ret < 0)
2697                 return ret;
2698
2699         /* Check if device has been configured before */
2700         if (target_dev_configured(&udev->se_dev)) {
2701                 ret = tcmu_send_emulate_write_cache(udev, val);
2702                 if (ret) {
2703                         pr_err("Unable to reconfigure device\n");
2704                         return ret;
2705                 }
2706         }
2707
2708         da->emulate_write_cache = val;
2709         return count;
2710 }
2711 CONFIGFS_ATTR(tcmu_, emulate_write_cache);
2712
2713 static ssize_t tcmu_tmr_notification_show(struct config_item *item, char *page)
2714 {
2715         struct se_dev_attrib *da = container_of(to_config_group(item),
2716                                         struct se_dev_attrib, da_group);
2717         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2718
2719         return snprintf(page, PAGE_SIZE, "%i\n",
2720                         test_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags));
2721 }
2722
2723 static ssize_t tcmu_tmr_notification_store(struct config_item *item,
2724                                            const char *page, size_t count)
2725 {
2726         struct se_dev_attrib *da = container_of(to_config_group(item),
2727                                         struct se_dev_attrib, da_group);
2728         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2729         u8 val;
2730         int ret;
2731
2732         ret = kstrtou8(page, 0, &val);
2733         if (ret < 0)
2734                 return ret;
2735         if (val > 1)
2736                 return -EINVAL;
2737
2738         if (val)
2739                 set_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags);
2740         else
2741                 clear_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags);
2742         return count;
2743 }
2744 CONFIGFS_ATTR(tcmu_, tmr_notification);
2745
2746 static ssize_t tcmu_block_dev_show(struct config_item *item, char *page)
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
2753         if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
2754                 return snprintf(page, PAGE_SIZE, "%s\n", "blocked");
2755         else
2756                 return snprintf(page, PAGE_SIZE, "%s\n", "unblocked");
2757 }
2758
2759 static ssize_t tcmu_block_dev_store(struct config_item *item, const char *page,
2760                                     size_t count)
2761 {
2762         struct se_device *se_dev = container_of(to_config_group(item),
2763                                                 struct se_device,
2764                                                 dev_action_group);
2765         struct tcmu_dev *udev = TCMU_DEV(se_dev);
2766         u8 val;
2767         int ret;
2768
2769         if (!target_dev_configured(&udev->se_dev)) {
2770                 pr_err("Device is not configured.\n");
2771                 return -EINVAL;
2772         }
2773
2774         ret = kstrtou8(page, 0, &val);
2775         if (ret < 0)
2776                 return ret;
2777
2778         if (val > 1) {
2779                 pr_err("Invalid block value %d\n", val);
2780                 return -EINVAL;
2781         }
2782
2783         if (!val)
2784                 tcmu_unblock_dev(udev);
2785         else
2786                 tcmu_block_dev(udev);
2787         return count;
2788 }
2789 CONFIGFS_ATTR(tcmu_, block_dev);
2790
2791 static ssize_t tcmu_reset_ring_store(struct config_item *item, const char *page,
2792                                      size_t count)
2793 {
2794         struct se_device *se_dev = container_of(to_config_group(item),
2795                                                 struct se_device,
2796                                                 dev_action_group);
2797         struct tcmu_dev *udev = TCMU_DEV(se_dev);
2798         u8 val;
2799         int ret;
2800
2801         if (!target_dev_configured(&udev->se_dev)) {
2802                 pr_err("Device is not configured.\n");
2803                 return -EINVAL;
2804         }
2805
2806         ret = kstrtou8(page, 0, &val);
2807         if (ret < 0)
2808                 return ret;
2809
2810         if (val != 1 && val != 2) {
2811                 pr_err("Invalid reset ring value %d\n", val);
2812                 return -EINVAL;
2813         }
2814
2815         tcmu_reset_ring(udev, val);
2816         return count;
2817 }
2818 CONFIGFS_ATTR_WO(tcmu_, reset_ring);
2819
2820 static struct configfs_attribute *tcmu_attrib_attrs[] = {
2821         &tcmu_attr_cmd_time_out,
2822         &tcmu_attr_qfull_time_out,
2823         &tcmu_attr_max_data_area_mb,
2824         &tcmu_attr_dev_config,
2825         &tcmu_attr_dev_size,
2826         &tcmu_attr_emulate_write_cache,
2827         &tcmu_attr_tmr_notification,
2828         &tcmu_attr_nl_reply_supported,
2829         NULL,
2830 };
2831
2832 static struct configfs_attribute **tcmu_attrs;
2833
2834 static struct configfs_attribute *tcmu_action_attrs[] = {
2835         &tcmu_attr_block_dev,
2836         &tcmu_attr_reset_ring,
2837         NULL,
2838 };
2839
2840 static struct target_backend_ops tcmu_ops = {
2841         .name                   = "user",
2842         .owner                  = THIS_MODULE,
2843         .transport_flags_default = TRANSPORT_FLAG_PASSTHROUGH,
2844         .transport_flags_changeable = TRANSPORT_FLAG_PASSTHROUGH_PGR |
2845                                       TRANSPORT_FLAG_PASSTHROUGH_ALUA,
2846         .attach_hba             = tcmu_attach_hba,
2847         .detach_hba             = tcmu_detach_hba,
2848         .alloc_device           = tcmu_alloc_device,
2849         .configure_device       = tcmu_configure_device,
2850         .destroy_device         = tcmu_destroy_device,
2851         .free_device            = tcmu_free_device,
2852         .parse_cdb              = tcmu_parse_cdb,
2853         .tmr_notify             = tcmu_tmr_notify,
2854         .set_configfs_dev_params = tcmu_set_configfs_dev_params,
2855         .show_configfs_dev_params = tcmu_show_configfs_dev_params,
2856         .get_device_type        = sbc_get_device_type,
2857         .get_blocks             = tcmu_get_blocks,
2858         .tb_dev_action_attrs    = tcmu_action_attrs,
2859 };
2860
2861 static void find_free_blocks(void)
2862 {
2863         struct tcmu_dev *udev;
2864         loff_t off;
2865         u32 start, end, block, total_freed = 0;
2866
2867         if (atomic_read(&global_db_count) <= tcmu_global_max_blocks)
2868                 return;
2869
2870         mutex_lock(&root_udev_mutex);
2871         list_for_each_entry(udev, &root_udev, node) {
2872                 mutex_lock(&udev->cmdr_lock);
2873
2874                 if (!target_dev_configured(&udev->se_dev)) {
2875                         mutex_unlock(&udev->cmdr_lock);
2876                         continue;
2877                 }
2878
2879                 /* Try to complete the finished commands first */
2880                 if (tcmu_handle_completions(udev))
2881                         run_qfull_queue(udev, false);
2882
2883                 /* Skip the udevs in idle */
2884                 if (!udev->dbi_thresh) {
2885                         mutex_unlock(&udev->cmdr_lock);
2886                         continue;
2887                 }
2888
2889                 end = udev->dbi_max + 1;
2890                 block = find_last_bit(udev->data_bitmap, end);
2891                 if (block == udev->dbi_max) {
2892                         /*
2893                          * The last bit is dbi_max, so it is not possible
2894                          * reclaim any blocks.
2895                          */
2896                         mutex_unlock(&udev->cmdr_lock);
2897                         continue;
2898                 } else if (block == end) {
2899                         /* The current udev will goto idle state */
2900                         udev->dbi_thresh = start = 0;
2901                         udev->dbi_max = 0;
2902                 } else {
2903                         udev->dbi_thresh = start = block + 1;
2904                         udev->dbi_max = block;
2905                 }
2906
2907                 /* Here will truncate the data area from off */
2908                 off = udev->data_off + start * DATA_BLOCK_SIZE;
2909                 unmap_mapping_range(udev->inode->i_mapping, off, 0, 1);
2910
2911                 /* Release the block pages */
2912                 tcmu_blocks_release(&udev->data_blocks, start, end);
2913                 mutex_unlock(&udev->cmdr_lock);
2914
2915                 total_freed += end - start;
2916                 pr_debug("Freed %u blocks (total %u) from %s.\n", end - start,
2917                          total_freed, udev->name);
2918         }
2919         mutex_unlock(&root_udev_mutex);
2920
2921         if (atomic_read(&global_db_count) > tcmu_global_max_blocks)
2922                 schedule_delayed_work(&tcmu_unmap_work, msecs_to_jiffies(5000));
2923 }
2924
2925 static void check_timedout_devices(void)
2926 {
2927         struct tcmu_dev *udev, *tmp_dev;
2928         struct tcmu_cmd *cmd, *tmp_cmd;
2929         LIST_HEAD(devs);
2930
2931         spin_lock_bh(&timed_out_udevs_lock);
2932         list_splice_init(&timed_out_udevs, &devs);
2933
2934         list_for_each_entry_safe(udev, tmp_dev, &devs, timedout_entry) {
2935                 list_del_init(&udev->timedout_entry);
2936                 spin_unlock_bh(&timed_out_udevs_lock);
2937
2938                 mutex_lock(&udev->cmdr_lock);
2939
2940                 /*
2941                  * If cmd_time_out is disabled but qfull is set deadline
2942                  * will only reflect the qfull timeout. Ignore it.
2943                  */
2944                 if (udev->cmd_time_out) {
2945                         list_for_each_entry_safe(cmd, tmp_cmd,
2946                                                  &udev->inflight_queue,
2947                                                  queue_entry) {
2948                                 tcmu_check_expired_ring_cmd(cmd);
2949                         }
2950                         tcmu_set_next_deadline(&udev->inflight_queue,
2951                                                &udev->cmd_timer);
2952                 }
2953                 list_for_each_entry_safe(cmd, tmp_cmd, &udev->qfull_queue,
2954                                          queue_entry) {
2955                         tcmu_check_expired_queue_cmd(cmd);
2956                 }
2957                 tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
2958
2959                 mutex_unlock(&udev->cmdr_lock);
2960
2961                 spin_lock_bh(&timed_out_udevs_lock);
2962         }
2963
2964         spin_unlock_bh(&timed_out_udevs_lock);
2965 }
2966
2967 static void tcmu_unmap_work_fn(struct work_struct *work)
2968 {
2969         check_timedout_devices();
2970         find_free_blocks();
2971 }
2972
2973 static int __init tcmu_module_init(void)
2974 {
2975         int ret, i, k, len = 0;
2976
2977         BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry) % TCMU_OP_ALIGN_SIZE) != 0);
2978
2979         INIT_DELAYED_WORK(&tcmu_unmap_work, tcmu_unmap_work_fn);
2980
2981         tcmu_cmd_cache = kmem_cache_create("tcmu_cmd_cache",
2982                                 sizeof(struct tcmu_cmd),
2983                                 __alignof__(struct tcmu_cmd),
2984                                 0, NULL);
2985         if (!tcmu_cmd_cache)
2986                 return -ENOMEM;
2987
2988         tcmu_root_device = root_device_register("tcm_user");
2989         if (IS_ERR(tcmu_root_device)) {
2990                 ret = PTR_ERR(tcmu_root_device);
2991                 goto out_free_cache;
2992         }
2993
2994         ret = genl_register_family(&tcmu_genl_family);
2995         if (ret < 0) {
2996                 goto out_unreg_device;
2997         }
2998
2999         for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
3000                 len += sizeof(struct configfs_attribute *);
3001         for (i = 0; passthrough_pr_attrib_attrs[i] != NULL; i++)
3002                 len += sizeof(struct configfs_attribute *);
3003         for (i = 0; tcmu_attrib_attrs[i] != NULL; i++)
3004                 len += sizeof(struct configfs_attribute *);
3005         len += sizeof(struct configfs_attribute *);
3006
3007         tcmu_attrs = kzalloc(len, GFP_KERNEL);
3008         if (!tcmu_attrs) {
3009                 ret = -ENOMEM;
3010                 goto out_unreg_genl;
3011         }
3012
3013         for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
3014                 tcmu_attrs[i] = passthrough_attrib_attrs[i];
3015         for (k = 0; passthrough_pr_attrib_attrs[k] != NULL; k++)
3016                 tcmu_attrs[i++] = passthrough_pr_attrib_attrs[k];
3017         for (k = 0; tcmu_attrib_attrs[k] != NULL; k++)
3018                 tcmu_attrs[i++] = tcmu_attrib_attrs[k];
3019         tcmu_ops.tb_dev_attrib_attrs = tcmu_attrs;
3020
3021         ret = transport_backend_register(&tcmu_ops);
3022         if (ret)
3023                 goto out_attrs;
3024
3025         return 0;
3026
3027 out_attrs:
3028         kfree(tcmu_attrs);
3029 out_unreg_genl:
3030         genl_unregister_family(&tcmu_genl_family);
3031 out_unreg_device:
3032         root_device_unregister(tcmu_root_device);
3033 out_free_cache:
3034         kmem_cache_destroy(tcmu_cmd_cache);
3035
3036         return ret;
3037 }
3038
3039 static void __exit tcmu_module_exit(void)
3040 {
3041         cancel_delayed_work_sync(&tcmu_unmap_work);
3042         target_backend_unregister(&tcmu_ops);
3043         kfree(tcmu_attrs);
3044         genl_unregister_family(&tcmu_genl_family);
3045         root_device_unregister(tcmu_root_device);
3046         kmem_cache_destroy(tcmu_cmd_cache);
3047 }
3048
3049 MODULE_DESCRIPTION("TCM USER subsystem plugin");
3050 MODULE_AUTHOR("Shaohua Li <shli@kernel.org>");
3051 MODULE_AUTHOR("Andy Grover <agrover@redhat.com>");
3052 MODULE_LICENSE("GPL");
3053
3054 module_init(tcmu_module_init);
3055 module_exit(tcmu_module_exit);