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/kernel.h>
  12 #include <linux/timer.h>
  13 #include <linux/parser.h>
  14 #include <linux/vmalloc.h>
  15 #include <linux/uio_driver.h>
  16 #include <linux/xarray.h>
  17 #include <linux/stringify.h>
  18 #include <linux/bitops.h>
  19 #include <linux/highmem.h>
  20 #include <linux/configfs.h>
  21 #include <linux/mutex.h>
  22 #include <linux/workqueue.h>
  23 #include <net/genetlink.h>
  24 #include <scsi/scsi_common.h>
  25 #include <scsi/scsi_proto.h>
  26 #include <target/target_core_base.h>
  27 #include <target/target_core_fabric.h>
  28 #include <target/target_core_backend.h>
  29
  30 #include <linux/target_core_user.h>
  31
  32 /**
  33  * DOC: Userspace I/O
  34  * Userspace I/O
  35  * -------------
  36  *
  37  * Define a shared-memory interface for LIO to pass SCSI commands and
  38  * data to userspace for processing. This is to allow backends that
  39  * are too complex for in-kernel support to be possible.
  40  *
  41  * It uses the UIO framework to do a lot of the device-creation and
  42  * introspection work for us.
  43  *
  44  * See the .h file for how the ring is laid out. Note that while the
  45  * command ring is defined, the particulars of the data area are
  46  * not. Offset values in the command entry point to other locations
  47  * internal to the mmap-ed area. There is separate space outside the
  48  * command ring for data buffers. This leaves maximum flexibility for
  49  * moving buffer allocations, or even page flipping or other
  50  * allocation techniques, without altering the command ring layout.
  51  *
  52  * SECURITY:
  53  * The user process must be assumed to be malicious. There's no way to
  54  * prevent it breaking the command ring protocol if it wants, but in
  55  * order to prevent other issues we must only ever read *data* from
  56  * the shared memory area, not offsets or sizes. This applies to
  57  * command ring entries as well as the mailbox. Extra code needed for
  58  * this may have a 'UAM' comment.
  59  */
  60
  61 #define TCMU_TIME_OUT (30 * MSEC_PER_SEC)
  62
  63 /* For mailbox plus cmd ring, the size is fixed 8MB */
  64 #define MB_CMDR_SIZE (8 * 1024 * 1024)
  65 /* Offset of cmd ring is size of mailbox */
  66 #define CMDR_OFF sizeof(struct tcmu_mailbox)
  67 #define CMDR_SIZE (MB_CMDR_SIZE - CMDR_OFF)
  68
  69 /*
  70  * For data area, the default block size is PAGE_SIZE and
  71  * the default total size is 256K * PAGE_SIZE.
  72  */
  73 #define DATA_PAGES_PER_BLK_DEF 1
  74 #define DATA_AREA_PAGES_DEF (256 * 1024)
  75
  76 #define TCMU_MBS_TO_PAGES(_mbs) ((size_t)_mbs << (20 - PAGE_SHIFT))
  77 #define TCMU_PAGES_TO_MBS(_pages) (_pages >> (20 - PAGE_SHIFT))
  78
  79 /*
  80  * Default number of global data blocks(512K * PAGE_SIZE)
  81  * when the unmap thread will be started.
  82  */
  83 #define TCMU_GLOBAL_MAX_PAGES_DEF (512 * 1024)
  84
  85 static u8 tcmu_kern_cmd_reply_supported;
  86 static u8 tcmu_netlink_blocked;
  87
  88 static struct device *tcmu_root_device;
  89
  90 struct tcmu_hba {
  91         u32 host_id;
  92 };
  93
  94 #define TCMU_CONFIG_LEN 256
  95
  96 static DEFINE_MUTEX(tcmu_nl_cmd_mutex);
  97 static LIST_HEAD(tcmu_nl_cmd_list);
  98
  99 struct tcmu_dev;
 100
 101 struct tcmu_nl_cmd {
 102         /* wake up thread waiting for reply */
 103         struct completion complete;
 104         struct list_head nl_list;
 105         struct tcmu_dev *udev;
 106         int cmd;
 107         int status;
 108 };
 109
 110 struct tcmu_dev {
 111         struct list_head node;
 112         struct kref kref;
 113
 114         struct se_device se_dev;
 115         struct se_dev_plug se_plug;
 116
 117         char *name;
 118         struct se_hba *hba;
 119
 120 #define TCMU_DEV_BIT_OPEN 0
 121 #define TCMU_DEV_BIT_BROKEN 1
 122 #define TCMU_DEV_BIT_BLOCKED 2
 123 #define TCMU_DEV_BIT_TMR_NOTIFY 3
 124 #define TCMU_DEV_BIT_PLUGGED 4
 125         unsigned long flags;
 126
 127         struct uio_info uio_info;
 128
 129         struct inode *inode;
 130
 131         uint64_t dev_size;
 132
 133         struct tcmu_mailbox *mb_addr;
 134         void *cmdr;
 135         u32 cmdr_size;
 136         u32 cmdr_last_cleaned;
 137         /* Offset of data area from start of mb */
 138         /* Must add data_off and mb_addr to get the address */
 139         size_t data_off;
 140         int data_area_mb;
 141         uint32_t max_blocks;
 142         size_t mmap_pages;
 143
 144         struct mutex cmdr_lock;
 145         struct list_head qfull_queue;
 146         struct list_head tmr_queue;
 147
 148         uint32_t dbi_max;
 149         uint32_t dbi_thresh;
 150         unsigned long *data_bitmap;
 151         struct xarray data_pages;
 152         uint32_t data_pages_per_blk;
 153         uint32_t data_blk_size;
 154
 155         struct xarray commands;
 156
 157         struct timer_list cmd_timer;
 158         unsigned int cmd_time_out;
 159         struct list_head inflight_queue;
 160
 161         struct timer_list qfull_timer;
 162         int qfull_time_out;
 163
 164         struct list_head timedout_entry;
 165
 166         struct tcmu_nl_cmd curr_nl_cmd;
 167
 168         char dev_config[TCMU_CONFIG_LEN];
 169
 170         int nl_reply_supported;
 171 };
 172
 173 #define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev)
 174
 175 struct tcmu_cmd {
 176         struct se_cmd *se_cmd;
 177         struct tcmu_dev *tcmu_dev;
 178         struct list_head queue_entry;
 179
 180         uint16_t cmd_id;
 181
 182         /* Can't use se_cmd when cleaning up expired cmds, because if
 183            cmd has been completed then accessing se_cmd is off limits */
 184         uint32_t dbi_cnt;
 185         uint32_t dbi_bidi_cnt;
 186         uint32_t dbi_cur;
 187         uint32_t *dbi;
 188
 189         uint32_t data_len_bidi;
 190
 191         unsigned long deadline;
 192
 193 #define TCMU_CMD_BIT_EXPIRED 0
 194 #define TCMU_CMD_BIT_KEEP_BUF 1
 195         unsigned long flags;
 196 };
 197
 198 struct tcmu_tmr {
 199         struct list_head queue_entry;
 200
 201         uint8_t tmr_type;
 202         uint32_t tmr_cmd_cnt;
 203         int16_t tmr_cmd_ids[];
 204 };
 205
 206 /*
 207  * To avoid dead lock the mutex lock order should always be:
 208  *
 209  * mutex_lock(&root_udev_mutex);
 210  * ...
 211  * mutex_lock(&tcmu_dev->cmdr_lock);
 212  * mutex_unlock(&tcmu_dev->cmdr_lock);
 213  * ...
 214  * mutex_unlock(&root_udev_mutex);
 215  */
 216 static DEFINE_MUTEX(root_udev_mutex);
 217 static LIST_HEAD(root_udev);
 218
 219 static DEFINE_SPINLOCK(timed_out_udevs_lock);
 220 static LIST_HEAD(timed_out_udevs);
 221
 222 static struct kmem_cache *tcmu_cmd_cache;
 223
 224 static atomic_t global_page_count = ATOMIC_INIT(0);
 225 static struct delayed_work tcmu_unmap_work;
 226 static int tcmu_global_max_pages = TCMU_GLOBAL_MAX_PAGES_DEF;
 227
 228 static int tcmu_set_global_max_data_area(const char *str,
 229                                          const struct kernel_param *kp)
 230 {
 231         int ret, max_area_mb;
 232
 233         ret = kstrtoint(str, 10, &max_area_mb);
 234         if (ret)
 235                 return -EINVAL;
 236
 237         if (max_area_mb <= 0) {
 238                 pr_err("global_max_data_area must be larger than 0.\n");
 239                 return -EINVAL;
 240         }
 241
 242         tcmu_global_max_pages = TCMU_MBS_TO_PAGES(max_area_mb);
 243         if (atomic_read(&global_page_count) > tcmu_global_max_pages)
 244                 schedule_delayed_work(&tcmu_unmap_work, 0);
 245         else
 246                 cancel_delayed_work_sync(&tcmu_unmap_work);
 247
 248         return 0;
 249 }
 250
 251 static int tcmu_get_global_max_data_area(char *buffer,
 252                                          const struct kernel_param *kp)
 253 {
 254         return sprintf(buffer, "%d\n", TCMU_PAGES_TO_MBS(tcmu_global_max_pages));
 255 }
 256
 257 static const struct kernel_param_ops tcmu_global_max_data_area_op = {
 258         .set = tcmu_set_global_max_data_area,
 259         .get = tcmu_get_global_max_data_area,
 260 };
 261
 262 module_param_cb(global_max_data_area_mb, &tcmu_global_max_data_area_op, NULL,
 263                 S_IWUSR | S_IRUGO);
 264 MODULE_PARM_DESC(global_max_data_area_mb,
 265                  "Max MBs allowed to be allocated to all the tcmu device's "
 266                  "data areas.");
 267
 268 static int tcmu_get_block_netlink(char *buffer,
 269                                   const struct kernel_param *kp)
 270 {
 271         return sprintf(buffer, "%s\n", tcmu_netlink_blocked ?
 272                        "blocked" : "unblocked");
 273 }
 274
 275 static int tcmu_set_block_netlink(const char *str,
 276                                   const struct kernel_param *kp)
 277 {
 278         int ret;
 279         u8 val;
 280
 281         ret = kstrtou8(str, 0, &val);
 282         if (ret < 0)
 283                 return ret;
 284
 285         if (val > 1) {
 286                 pr_err("Invalid block netlink value %u\n", val);
 287                 return -EINVAL;
 288         }
 289
 290         tcmu_netlink_blocked = val;
 291         return 0;
 292 }
 293
 294 static const struct kernel_param_ops tcmu_block_netlink_op = {
 295         .set = tcmu_set_block_netlink,
 296         .get = tcmu_get_block_netlink,
 297 };
 298
 299 module_param_cb(block_netlink, &tcmu_block_netlink_op, NULL, S_IWUSR | S_IRUGO);
 300 MODULE_PARM_DESC(block_netlink, "Block new netlink commands.");
 301
 302 static int tcmu_fail_netlink_cmd(struct tcmu_nl_cmd *nl_cmd)
 303 {
 304         struct tcmu_dev *udev = nl_cmd->udev;
 305
 306         if (!tcmu_netlink_blocked) {
 307                 pr_err("Could not reset device's netlink interface. Netlink is not blocked.\n");
 308                 return -EBUSY;
 309         }
 310
 311         if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
 312                 pr_debug("Aborting nl cmd %d on %s\n", nl_cmd->cmd, udev->name);
 313                 nl_cmd->status = -EINTR;
 314                 list_del(&nl_cmd->nl_list);
 315                 complete(&nl_cmd->complete);
 316         }
 317         return 0;
 318 }
 319
 320 static int tcmu_set_reset_netlink(const char *str,
 321                                   const struct kernel_param *kp)
 322 {
 323         struct tcmu_nl_cmd *nl_cmd, *tmp_cmd;
 324         int ret;
 325         u8 val;
 326
 327         ret = kstrtou8(str, 0, &val);
 328         if (ret < 0)
 329                 return ret;
 330
 331         if (val != 1) {
 332                 pr_err("Invalid reset netlink value %u\n", val);
 333                 return -EINVAL;
 334         }
 335
 336         mutex_lock(&tcmu_nl_cmd_mutex);
 337         list_for_each_entry_safe(nl_cmd, tmp_cmd, &tcmu_nl_cmd_list, nl_list) {
 338                 ret = tcmu_fail_netlink_cmd(nl_cmd);
 339                 if (ret)
 340                         break;
 341         }
 342         mutex_unlock(&tcmu_nl_cmd_mutex);
 343
 344         return ret;
 345 }
 346
 347 static const struct kernel_param_ops tcmu_reset_netlink_op = {
 348         .set = tcmu_set_reset_netlink,
 349 };
 350
 351 module_param_cb(reset_netlink, &tcmu_reset_netlink_op, NULL, S_IWUSR);
 352 MODULE_PARM_DESC(reset_netlink, "Reset netlink commands.");
 353
 354 /* multicast group */
 355 enum tcmu_multicast_groups {
 356         TCMU_MCGRP_CONFIG,
 357 };
 358
 359 static const struct genl_multicast_group tcmu_mcgrps[] = {
 360         [TCMU_MCGRP_CONFIG] = { .name = "config", },
 361 };
 362
 363 static struct nla_policy tcmu_attr_policy[TCMU_ATTR_MAX+1] = {
 364         [TCMU_ATTR_DEVICE]      = { .type = NLA_STRING },
 365         [TCMU_ATTR_MINOR]       = { .type = NLA_U32 },
 366         [TCMU_ATTR_CMD_STATUS]  = { .type = NLA_S32 },
 367         [TCMU_ATTR_DEVICE_ID]   = { .type = NLA_U32 },
 368         [TCMU_ATTR_SUPP_KERN_CMD_REPLY] = { .type = NLA_U8 },
 369 };
 370
 371 static int tcmu_genl_cmd_done(struct genl_info *info, int completed_cmd)
 372 {
 373         struct tcmu_dev *udev = NULL;
 374         struct tcmu_nl_cmd *nl_cmd;
 375         int dev_id, rc, ret = 0;
 376
 377         if (!info->attrs[TCMU_ATTR_CMD_STATUS] ||
 378             !info->attrs[TCMU_ATTR_DEVICE_ID]) {
 379                 printk(KERN_ERR "TCMU_ATTR_CMD_STATUS or TCMU_ATTR_DEVICE_ID not set, doing nothing\n");
 380                 return -EINVAL;
 381         }
 382
 383         dev_id = nla_get_u32(info->attrs[TCMU_ATTR_DEVICE_ID]);
 384         rc = nla_get_s32(info->attrs[TCMU_ATTR_CMD_STATUS]);
 385
 386         mutex_lock(&tcmu_nl_cmd_mutex);
 387         list_for_each_entry(nl_cmd, &tcmu_nl_cmd_list, nl_list) {
 388                 if (nl_cmd->udev->se_dev.dev_index == dev_id) {
 389                         udev = nl_cmd->udev;
 390                         break;
 391                 }
 392         }
 393
 394         if (!udev) {
 395                 pr_err("tcmu nl cmd %u/%d completion could not find device with dev id %u.\n",
 396                        completed_cmd, rc, dev_id);
 397                 ret = -ENODEV;
 398                 goto unlock;
 399         }
 400         list_del(&nl_cmd->nl_list);
 401
 402         pr_debug("%s genl cmd done got id %d curr %d done %d rc %d stat %d\n",
 403                  udev->name, dev_id, nl_cmd->cmd, completed_cmd, rc,
 404                  nl_cmd->status);
 405
 406         if (nl_cmd->cmd != completed_cmd) {
 407                 pr_err("Mismatched commands on %s (Expecting reply for %d. Current %d).\n",
 408                        udev->name, completed_cmd, nl_cmd->cmd);
 409                 ret = -EINVAL;
 410                 goto unlock;
 411         }
 412
 413         nl_cmd->status = rc;
 414         complete(&nl_cmd->complete);
 415 unlock:
 416         mutex_unlock(&tcmu_nl_cmd_mutex);
 417         return ret;
 418 }
 419
 420 static int tcmu_genl_rm_dev_done(struct sk_buff *skb, struct genl_info *info)
 421 {
 422         return tcmu_genl_cmd_done(info, TCMU_CMD_REMOVED_DEVICE);
 423 }
 424
 425 static int tcmu_genl_add_dev_done(struct sk_buff *skb, struct genl_info *info)
 426 {
 427         return tcmu_genl_cmd_done(info, TCMU_CMD_ADDED_DEVICE);
 428 }
 429
 430 static int tcmu_genl_reconfig_dev_done(struct sk_buff *skb,
 431                                        struct genl_info *info)
 432 {
 433         return tcmu_genl_cmd_done(info, TCMU_CMD_RECONFIG_DEVICE);
 434 }
 435
 436 static int tcmu_genl_set_features(struct sk_buff *skb, struct genl_info *info)
 437 {
 438         if (info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]) {
 439                 tcmu_kern_cmd_reply_supported  =
 440                         nla_get_u8(info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]);
 441                 printk(KERN_INFO "tcmu daemon: command reply support %u.\n",
 442                        tcmu_kern_cmd_reply_supported);
 443         }
 444
 445         return 0;
 446 }
 447
 448 static const struct genl_small_ops tcmu_genl_ops[] = {
 449         {
 450                 .cmd    = TCMU_CMD_SET_FEATURES,
 451                 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 452                 .flags  = GENL_ADMIN_PERM,
 453                 .doit   = tcmu_genl_set_features,
 454         },
 455         {
 456                 .cmd    = TCMU_CMD_ADDED_DEVICE_DONE,
 457                 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 458                 .flags  = GENL_ADMIN_PERM,
 459                 .doit   = tcmu_genl_add_dev_done,
 460         },
 461         {
 462                 .cmd    = TCMU_CMD_REMOVED_DEVICE_DONE,
 463                 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 464                 .flags  = GENL_ADMIN_PERM,
 465                 .doit   = tcmu_genl_rm_dev_done,
 466         },
 467         {
 468                 .cmd    = TCMU_CMD_RECONFIG_DEVICE_DONE,
 469                 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 470                 .flags  = GENL_ADMIN_PERM,
 471                 .doit   = tcmu_genl_reconfig_dev_done,
 472         },
 473 };
 474
 475 /* Our generic netlink family */
 476 static struct genl_family tcmu_genl_family __ro_after_init = {
 477         .module = THIS_MODULE,
 478         .hdrsize = 0,
 479         .name = "TCM-USER",
 480         .version = 2,
 481         .maxattr = TCMU_ATTR_MAX,
 482         .policy = tcmu_attr_policy,
 483         .mcgrps = tcmu_mcgrps,
 484         .n_mcgrps = ARRAY_SIZE(tcmu_mcgrps),
 485         .netnsok = true,
 486         .small_ops = tcmu_genl_ops,
 487         .n_small_ops = ARRAY_SIZE(tcmu_genl_ops),
 488 };
 489
 490 #define tcmu_cmd_set_dbi_cur(cmd, index) ((cmd)->dbi_cur = (index))
 491 #define tcmu_cmd_reset_dbi_cur(cmd) tcmu_cmd_set_dbi_cur(cmd, 0)
 492 #define tcmu_cmd_set_dbi(cmd, index) ((cmd)->dbi[(cmd)->dbi_cur++] = (index))
 493 #define tcmu_cmd_get_dbi(cmd) ((cmd)->dbi[(cmd)->dbi_cur++])
 494
 495 static void tcmu_cmd_free_data(struct tcmu_cmd *tcmu_cmd, uint32_t len)
 496 {
 497         struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
 498         uint32_t i;
 499
 500         for (i = 0; i < len; i++)
 501                 clear_bit(tcmu_cmd->dbi[i], udev->data_bitmap);
 502 }
 503
 504 static inline int tcmu_get_empty_block(struct tcmu_dev *udev,
 505                                        struct tcmu_cmd *tcmu_cmd,
 506                                        int prev_dbi, int length, int *iov_cnt)
 507 {
 508         XA_STATE(xas, &udev->data_pages, 0);
 509         struct page *page;
 510         int i, cnt, dbi, dpi;
 511         int page_cnt = DIV_ROUND_UP(length, PAGE_SIZE);
 512
 513         dbi = find_first_zero_bit(udev->data_bitmap, udev->dbi_thresh);
 514         if (dbi == udev->dbi_thresh)
 515                 return -1;
 516
 517         dpi = dbi * udev->data_pages_per_blk;
 518         /* Count the number of already allocated pages */
 519         xas_set(&xas, dpi);
 520         rcu_read_lock();
 521         for (cnt = 0; xas_next(&xas) && cnt < page_cnt;)
 522                 cnt++;
 523         rcu_read_unlock();
 524
 525         for (i = cnt; i < page_cnt; i++) {
 526                 /* try to get new page from the mm */
 527                 page = alloc_page(GFP_NOIO);
 528                 if (!page)
 529                         break;
 530
 531                 if (xa_store(&udev->data_pages, dpi + i, page, GFP_NOIO)) {
 532                         __free_page(page);
 533                         break;
 534                 }
 535         }
 536         if (atomic_add_return(i - cnt, &global_page_count) >
 537                               tcmu_global_max_pages)
 538                 schedule_delayed_work(&tcmu_unmap_work, 0);
 539
 540         if (i && dbi > udev->dbi_max)
 541                 udev->dbi_max = dbi;
 542
 543         set_bit(dbi, udev->data_bitmap);
 544         tcmu_cmd_set_dbi(tcmu_cmd, dbi);
 545
 546         if (dbi != prev_dbi + 1)
 547                 *iov_cnt += 1;
 548
 549         return i == page_cnt ? dbi : -1;
 550 }
 551
 552 static int tcmu_get_empty_blocks(struct tcmu_dev *udev,
 553                                  struct tcmu_cmd *tcmu_cmd, int length)
 554 {
 555         /* start value of dbi + 1 must not be a valid dbi */
 556         int dbi = -2;
 557         int blk_data_len, iov_cnt = 0;
 558         uint32_t blk_size = udev->data_blk_size;
 559
 560         for (; length > 0; length -= blk_size) {
 561                 blk_data_len = min_t(uint32_t, length, blk_size);
 562                 dbi = tcmu_get_empty_block(udev, tcmu_cmd, dbi, blk_data_len,
 563                                            &iov_cnt);
 564                 if (dbi < 0)
 565                         return -1;
 566         }
 567         return iov_cnt;
 568 }
 569
 570 static inline void tcmu_free_cmd(struct tcmu_cmd *tcmu_cmd)
 571 {
 572         kfree(tcmu_cmd->dbi);
 573         kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
 574 }
 575
 576 static inline void tcmu_cmd_set_block_cnts(struct tcmu_cmd *cmd)
 577 {
 578         int i, len;
 579         struct se_cmd *se_cmd = cmd->se_cmd;
 580         uint32_t blk_size = cmd->tcmu_dev->data_blk_size;
 581
 582         cmd->dbi_cnt = DIV_ROUND_UP(se_cmd->data_length, blk_size);
 583
 584         if (se_cmd->se_cmd_flags & SCF_BIDI) {
 585                 BUG_ON(!(se_cmd->t_bidi_data_sg && se_cmd->t_bidi_data_nents));
 586                 for (i = 0, len = 0; i < se_cmd->t_bidi_data_nents; i++)
 587                         len += se_cmd->t_bidi_data_sg[i].length;
 588                 cmd->dbi_bidi_cnt = DIV_ROUND_UP(len, blk_size);
 589                 cmd->dbi_cnt += cmd->dbi_bidi_cnt;
 590                 cmd->data_len_bidi = len;
 591         }
 592 }
 593
 594 static int new_block_to_iov(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
 595                             struct iovec **iov, int prev_dbi, int len)
 596 {
 597         /* Get the next dbi */
 598         int dbi = tcmu_cmd_get_dbi(cmd);
 599
 600         /* Do not add more than udev->data_blk_size to iov */
 601         len = min_t(int,  len, udev->data_blk_size);
 602
 603         /*
 604          * The following code will gather and map the blocks to the same iovec
 605          * when the blocks are all next to each other.
 606          */
 607         if (dbi != prev_dbi + 1) {
 608                 /* dbi is not next to previous dbi, so start new iov */
 609                 if (prev_dbi >= 0)
 610                         (*iov)++;
 611                 /* write offset relative to mb_addr */
 612                 (*iov)->iov_base = (void __user *)
 613                                    (udev->data_off + dbi * udev->data_blk_size);
 614         }
 615         (*iov)->iov_len += len;
 616
 617         return dbi;
 618 }
 619
 620 static void tcmu_setup_iovs(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
 621                             struct iovec **iov, int data_length)
 622 {
 623         /* start value of dbi + 1 must not be a valid dbi */
 624         int dbi = -2;
 625
 626         /* We prepare the IOVs for DMA_FROM_DEVICE transfer direction */
 627         for (; data_length > 0; data_length -= udev->data_blk_size)
 628                 dbi = new_block_to_iov(udev, cmd, iov, dbi, data_length);
 629 }
 630
 631 static struct tcmu_cmd *tcmu_alloc_cmd(struct se_cmd *se_cmd)
 632 {
 633         struct se_device *se_dev = se_cmd->se_dev;
 634         struct tcmu_dev *udev = TCMU_DEV(se_dev);
 635         struct tcmu_cmd *tcmu_cmd;
 636
 637         tcmu_cmd = kmem_cache_zalloc(tcmu_cmd_cache, GFP_NOIO);
 638         if (!tcmu_cmd)
 639                 return NULL;
 640
 641         INIT_LIST_HEAD(&tcmu_cmd->queue_entry);
 642         tcmu_cmd->se_cmd = se_cmd;
 643         tcmu_cmd->tcmu_dev = udev;
 644
 645         tcmu_cmd_set_block_cnts(tcmu_cmd);
 646         tcmu_cmd->dbi = kcalloc(tcmu_cmd->dbi_cnt, sizeof(uint32_t),
 647                                 GFP_NOIO);
 648         if (!tcmu_cmd->dbi) {
 649                 kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
 650                 return NULL;
 651         }
 652
 653         return tcmu_cmd;
 654 }
 655
 656 static inline void tcmu_flush_dcache_range(void *vaddr, size_t size)
 657 {
 658         unsigned long offset = offset_in_page(vaddr);
 659         void *start = vaddr - offset;
 660
 661         size = round_up(size+offset, PAGE_SIZE);
 662
 663         while (size) {
 664                 flush_dcache_page(vmalloc_to_page(start));
 665                 start += PAGE_SIZE;
 666                 size -= PAGE_SIZE;
 667         }
 668 }
 669
 670 /*
 671  * Some ring helper functions. We don't assume size is a power of 2 so
 672  * we can't use circ_buf.h.
 673  */
 674 static inline size_t spc_used(size_t head, size_t tail, size_t size)
 675 {
 676         int diff = head - tail;
 677
 678         if (diff >= 0)
 679                 return diff;
 680         else
 681                 return size + diff;
 682 }
 683
 684 static inline size_t spc_free(size_t head, size_t tail, size_t size)
 685 {
 686         /* Keep 1 byte unused or we can't tell full from empty */
 687         return (size - spc_used(head, tail, size) - 1);
 688 }
 689
 690 static inline size_t head_to_end(size_t head, size_t size)
 691 {
 692         return size - head;
 693 }
 694
 695 #define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size)
 696
 697 #define TCMU_SG_TO_DATA_AREA 1
 698 #define TCMU_DATA_AREA_TO_SG 2
 699
 700 static inline void tcmu_copy_data(struct tcmu_dev *udev,
 701                                   struct tcmu_cmd *tcmu_cmd, uint32_t direction,
 702                                   struct scatterlist *sg, unsigned int sg_nents,
 703                                   struct iovec **iov, size_t data_len)
 704 {
 705         /* start value of dbi + 1 must not be a valid dbi */
 706         int dbi = -2;
 707         size_t page_remaining, cp_len;
 708         int page_cnt, page_inx, dpi;
 709         struct sg_mapping_iter sg_iter;
 710         unsigned int sg_flags;
 711         struct page *page;
 712         void *data_page_start, *data_addr;
 713
 714         if (direction == TCMU_SG_TO_DATA_AREA)
 715                 sg_flags = SG_MITER_ATOMIC | SG_MITER_FROM_SG;
 716         else
 717                 sg_flags = SG_MITER_ATOMIC | SG_MITER_TO_SG;
 718         sg_miter_start(&sg_iter, sg, sg_nents, sg_flags);
 719
 720         while (data_len) {
 721                 if (direction == TCMU_SG_TO_DATA_AREA)
 722                         dbi = new_block_to_iov(udev, tcmu_cmd, iov, dbi,
 723                                                data_len);
 724                 else
 725                         dbi = tcmu_cmd_get_dbi(tcmu_cmd);
 726
 727                 page_cnt = DIV_ROUND_UP(data_len, PAGE_SIZE);
 728                 if (page_cnt > udev->data_pages_per_blk)
 729                         page_cnt = udev->data_pages_per_blk;
 730
 731                 dpi = dbi * udev->data_pages_per_blk;
 732                 for (page_inx = 0; page_inx < page_cnt && data_len;
 733                      page_inx++, dpi++) {
 734                         page = xa_load(&udev->data_pages, dpi);
 735
 736                         if (direction == TCMU_DATA_AREA_TO_SG)
 737                                 flush_dcache_page(page);
 738                         data_page_start = kmap_atomic(page);
 739                         page_remaining = PAGE_SIZE;
 740
 741                         while (page_remaining && data_len) {
 742                                 if (!sg_miter_next(&sg_iter)) {
 743                                         /* set length to 0 to abort outer loop */
 744                                         data_len = 0;
 745                                         pr_debug("%s: aborting data copy due to exhausted sg_list\n",
 746                                                  __func__);
 747                                         break;
 748                                 }
 749                                 cp_len = min3(sg_iter.length, page_remaining,
 750                                               data_len);
 751
 752                                 data_addr = data_page_start +
 753                                             PAGE_SIZE - page_remaining;
 754                                 if (direction == TCMU_SG_TO_DATA_AREA)
 755                                         memcpy(data_addr, sg_iter.addr, cp_len);
 756                                 else
 757                                         memcpy(sg_iter.addr, data_addr, cp_len);
 758
 759                                 data_len -= cp_len;
 760                                 page_remaining -= cp_len;
 761                                 sg_iter.consumed = cp_len;
 762                         }
 763                         sg_miter_stop(&sg_iter);
 764
 765                         kunmap_atomic(data_page_start);
 766                         if (direction == TCMU_SG_TO_DATA_AREA)
 767                                 flush_dcache_page(page);
 768                 }
 769         }
 770 }
 771
 772 static void scatter_data_area(struct tcmu_dev *udev, struct tcmu_cmd *tcmu_cmd,
 773                               struct iovec **iov)
 774 {
 775         struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
 776
 777         tcmu_copy_data(udev, tcmu_cmd, TCMU_SG_TO_DATA_AREA, se_cmd->t_data_sg,
 778                        se_cmd->t_data_nents, iov, se_cmd->data_length);
 779 }
 780
 781 static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *tcmu_cmd,
 782                              bool bidi, uint32_t read_len)
 783 {
 784         struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
 785         struct scatterlist *data_sg;
 786         unsigned int data_nents;
 787
 788         if (!bidi) {
 789                 data_sg = se_cmd->t_data_sg;
 790                 data_nents = se_cmd->t_data_nents;
 791         } else {
 792                 /*
 793                  * For bidi case, the first count blocks are for Data-Out
 794                  * buffer blocks, and before gathering the Data-In buffer
 795                  * the Data-Out buffer blocks should be skipped.
 796                  */
 797                 tcmu_cmd_set_dbi_cur(tcmu_cmd,
 798                                      tcmu_cmd->dbi_cnt - tcmu_cmd->dbi_bidi_cnt);
 799
 800                 data_sg = se_cmd->t_bidi_data_sg;
 801                 data_nents = se_cmd->t_bidi_data_nents;
 802         }
 803
 804         tcmu_copy_data(udev, tcmu_cmd, TCMU_DATA_AREA_TO_SG, data_sg,
 805                        data_nents, NULL, read_len);
 806 }
 807
 808 static inline size_t spc_bitmap_free(unsigned long *bitmap, uint32_t thresh)
 809 {
 810         return thresh - bitmap_weight(bitmap, thresh);
 811 }
 812
 813 /*
 814  * We can't queue a command until we have space available on the cmd ring.
 815  *
 816  * Called with ring lock held.
 817  */
 818 static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size)
 819 {
 820         struct tcmu_mailbox *mb = udev->mb_addr;
 821         size_t space, cmd_needed;
 822         u32 cmd_head;
 823
 824         tcmu_flush_dcache_range(mb, sizeof(*mb));
 825
 826         cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
 827
 828         /*
 829          * If cmd end-of-ring space is too small then we need space for a NOP plus
 830          * original cmd - cmds are internally contiguous.
 831          */
 832         if (head_to_end(cmd_head, udev->cmdr_size) >= cmd_size)
 833                 cmd_needed = cmd_size;
 834         else
 835                 cmd_needed = cmd_size + head_to_end(cmd_head, udev->cmdr_size);
 836
 837         space = spc_free(cmd_head, udev->cmdr_last_cleaned, udev->cmdr_size);
 838         if (space < cmd_needed) {
 839                 pr_debug("no cmd space: %u %u %u\n", cmd_head,
 840                        udev->cmdr_last_cleaned, udev->cmdr_size);
 841                 return false;
 842         }
 843         return true;
 844 }
 845
 846 /*
 847  * We have to allocate data buffers before we can queue a command.
 848  * Returns -1 on error (not enough space) or number of needed iovs on success
 849  *
 850  * Called with ring lock held.
 851  */
 852 static int tcmu_alloc_data_space(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
 853                                   int *iov_bidi_cnt)
 854 {
 855         int space, iov_cnt = 0, ret = 0;
 856
 857         if (!cmd->dbi_cnt)
 858                 goto wr_iov_cnts;
 859
 860         /* try to check and get the data blocks as needed */
 861         space = spc_bitmap_free(udev->data_bitmap, udev->dbi_thresh);
 862         if (space < cmd->dbi_cnt) {
 863                 unsigned long blocks_left =
 864                                 (udev->max_blocks - udev->dbi_thresh) + space;
 865
 866                 if (blocks_left < cmd->dbi_cnt) {
 867                         pr_debug("no data space: only %lu available, but ask for %u\n",
 868                                         blocks_left * udev->data_blk_size,
 869                                         cmd->dbi_cnt * udev->data_blk_size);
 870                         return -1;
 871                 }
 872
 873                 udev->dbi_thresh += cmd->dbi_cnt;
 874                 if (udev->dbi_thresh > udev->max_blocks)
 875                         udev->dbi_thresh = udev->max_blocks;
 876         }
 877
 878         iov_cnt = tcmu_get_empty_blocks(udev, cmd, cmd->se_cmd->data_length);
 879         if (iov_cnt < 0)
 880                 return -1;
 881
 882         if (cmd->dbi_bidi_cnt) {
 883                 ret = tcmu_get_empty_blocks(udev, cmd, cmd->data_len_bidi);
 884                 if (ret < 0)
 885                         return -1;
 886         }
 887 wr_iov_cnts:
 888         *iov_bidi_cnt = ret;
 889         return iov_cnt + ret;
 890 }
 891
 892 static inline size_t tcmu_cmd_get_base_cmd_size(size_t iov_cnt)
 893 {
 894         return max(offsetof(struct tcmu_cmd_entry, req.iov[iov_cnt]),
 895                         sizeof(struct tcmu_cmd_entry));
 896 }
 897
 898 static inline size_t tcmu_cmd_get_cmd_size(struct tcmu_cmd *tcmu_cmd,
 899                                            size_t base_command_size)
 900 {
 901         struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
 902         size_t command_size;
 903
 904         command_size = base_command_size +
 905                 round_up(scsi_command_size(se_cmd->t_task_cdb),
 906                                 TCMU_OP_ALIGN_SIZE);
 907
 908         WARN_ON(command_size & (TCMU_OP_ALIGN_SIZE-1));
 909
 910         return command_size;
 911 }
 912
 913 static void tcmu_setup_cmd_timer(struct tcmu_cmd *tcmu_cmd, unsigned int tmo,
 914                                  struct timer_list *timer)
 915 {
 916         if (!tmo)
 917                 return;
 918
 919         tcmu_cmd->deadline = round_jiffies_up(jiffies + msecs_to_jiffies(tmo));
 920         if (!timer_pending(timer))
 921                 mod_timer(timer, tcmu_cmd->deadline);
 922
 923         pr_debug("Timeout set up for cmd %p, dev = %s, tmo = %lu\n", tcmu_cmd,
 924                  tcmu_cmd->tcmu_dev->name, tmo / MSEC_PER_SEC);
 925 }
 926
 927 static int add_to_qfull_queue(struct tcmu_cmd *tcmu_cmd)
 928 {
 929         struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
 930         unsigned int tmo;
 931
 932         /*
 933          * For backwards compat if qfull_time_out is not set use
 934          * cmd_time_out and if that's not set use the default time out.
 935          */
 936         if (!udev->qfull_time_out)
 937                 return -ETIMEDOUT;
 938         else if (udev->qfull_time_out > 0)
 939                 tmo = udev->qfull_time_out;
 940         else if (udev->cmd_time_out)
 941                 tmo = udev->cmd_time_out;
 942         else
 943                 tmo = TCMU_TIME_OUT;
 944
 945         tcmu_setup_cmd_timer(tcmu_cmd, tmo, &udev->qfull_timer);
 946
 947         list_add_tail(&tcmu_cmd->queue_entry, &udev->qfull_queue);
 948         pr_debug("adding cmd %p on dev %s to ring space wait queue\n",
 949                  tcmu_cmd, udev->name);
 950         return 0;
 951 }
 952
 953 static uint32_t ring_insert_padding(struct tcmu_dev *udev, size_t cmd_size)
 954 {
 955         struct tcmu_cmd_entry_hdr *hdr;
 956         struct tcmu_mailbox *mb = udev->mb_addr;
 957         uint32_t cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
 958
 959         /* Insert a PAD if end-of-ring space is too small */
 960         if (head_to_end(cmd_head, udev->cmdr_size) < cmd_size) {
 961                 size_t pad_size = head_to_end(cmd_head, udev->cmdr_size);
 962
 963                 hdr = udev->cmdr + cmd_head;
 964                 tcmu_hdr_set_op(&hdr->len_op, TCMU_OP_PAD);
 965                 tcmu_hdr_set_len(&hdr->len_op, pad_size);
 966                 hdr->cmd_id = 0; /* not used for PAD */
 967                 hdr->kflags = 0;
 968                 hdr->uflags = 0;
 969                 tcmu_flush_dcache_range(hdr, sizeof(*hdr));
 970
 971                 UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size);
 972                 tcmu_flush_dcache_range(mb, sizeof(*mb));
 973
 974                 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
 975                 WARN_ON(cmd_head != 0);
 976         }
 977
 978         return cmd_head;
 979 }
 980
 981 static void tcmu_unplug_device(struct se_dev_plug *se_plug)
 982 {
 983         struct se_device *se_dev = se_plug->se_dev;
 984         struct tcmu_dev *udev = TCMU_DEV(se_dev);
 985
 986         clear_bit(TCMU_DEV_BIT_PLUGGED, &udev->flags);
 987         uio_event_notify(&udev->uio_info);
 988 }
 989
 990 static struct se_dev_plug *tcmu_plug_device(struct se_device *se_dev)
 991 {
 992         struct tcmu_dev *udev = TCMU_DEV(se_dev);
 993
 994         if (!test_and_set_bit(TCMU_DEV_BIT_PLUGGED, &udev->flags))
 995                 return &udev->se_plug;
 996
 997         return NULL;
 998 }
 999
1000 /**
1001  * queue_cmd_ring - queue cmd to ring or internally
1002  * @tcmu_cmd: cmd to queue
1003  * @scsi_err: TCM error code if failure (-1) returned.
1004  *
1005  * Returns:
1006  * -1 we cannot queue internally or to the ring.
1007  *  0 success
1008  *  1 internally queued to wait for ring memory to free.
1009  */
1010 static int queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, sense_reason_t *scsi_err)
1011 {
1012         struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
1013         struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
1014         size_t base_command_size, command_size;
1015         struct tcmu_mailbox *mb = udev->mb_addr;
1016         struct tcmu_cmd_entry *entry;
1017         struct iovec *iov;
1018         int iov_cnt, iov_bidi_cnt;
1019         uint32_t cmd_id, cmd_head;
1020         uint64_t cdb_off;
1021         uint32_t blk_size = udev->data_blk_size;
1022         /* size of data buffer needed */
1023         size_t data_length = (size_t)tcmu_cmd->dbi_cnt * blk_size;
1024
1025         *scsi_err = TCM_NO_SENSE;
1026
1027         if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags)) {
1028                 *scsi_err = TCM_LUN_BUSY;
1029                 return -1;
1030         }
1031
1032         if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
1033                 *scsi_err = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1034                 return -1;
1035         }
1036
1037         if (!list_empty(&udev->qfull_queue))
1038                 goto queue;
1039
1040         if (data_length > (size_t)udev->max_blocks * blk_size) {
1041                 pr_warn("TCMU: Request of size %zu is too big for %zu data area\n",
1042                         data_length, (size_t)udev->max_blocks * blk_size);
1043                 *scsi_err = TCM_INVALID_CDB_FIELD;
1044                 return -1;
1045         }
1046
1047         iov_cnt = tcmu_alloc_data_space(udev, tcmu_cmd, &iov_bidi_cnt);
1048         if (iov_cnt < 0)
1049                 goto free_and_queue;
1050
1051         /*
1052          * Must be a certain minimum size for response sense info, but
1053          * also may be larger if the iov array is large.
1054          */
1055         base_command_size = tcmu_cmd_get_base_cmd_size(iov_cnt);
1056         command_size = tcmu_cmd_get_cmd_size(tcmu_cmd, base_command_size);
1057
1058         if (command_size > (udev->cmdr_size / 2)) {
1059                 pr_warn("TCMU: Request of size %zu is too big for %u cmd ring\n",
1060                         command_size, udev->cmdr_size);
1061                 tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cur);
1062                 *scsi_err = TCM_INVALID_CDB_FIELD;
1063                 return -1;
1064         }
1065
1066         if (!is_ring_space_avail(udev, command_size))
1067                 /*
1068                  * Don't leave commands partially setup because the unmap
1069                  * thread might need the blocks to make forward progress.
1070                  */
1071                 goto free_and_queue;
1072
1073         if (xa_alloc(&udev->commands, &cmd_id, tcmu_cmd, XA_LIMIT(1, 0xffff),
1074                      GFP_NOWAIT) < 0) {
1075                 pr_err("tcmu: Could not allocate cmd id.\n");
1076
1077                 tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cnt);
1078                 *scsi_err = TCM_OUT_OF_RESOURCES;
1079                 return -1;
1080         }
1081         tcmu_cmd->cmd_id = cmd_id;
1082
1083         pr_debug("allocated cmd id %u for cmd %p dev %s\n", tcmu_cmd->cmd_id,
1084                  tcmu_cmd, udev->name);
1085
1086         cmd_head = ring_insert_padding(udev, command_size);
1087
1088         entry = udev->cmdr + cmd_head;
1089         memset(entry, 0, command_size);
1090         tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_CMD);
1091
1092         /* prepare iov list and copy data to data area if necessary */
1093         tcmu_cmd_reset_dbi_cur(tcmu_cmd);
1094         iov = &entry->req.iov[0];
1095
1096         if (se_cmd->data_direction == DMA_TO_DEVICE ||
1097             se_cmd->se_cmd_flags & SCF_BIDI)
1098                 scatter_data_area(udev, tcmu_cmd, &iov);
1099         else
1100                 tcmu_setup_iovs(udev, tcmu_cmd, &iov, se_cmd->data_length);
1101
1102         entry->req.iov_cnt = iov_cnt - iov_bidi_cnt;
1103
1104         /* Handle BIDI commands */
1105         if (se_cmd->se_cmd_flags & SCF_BIDI) {
1106                 iov++;
1107                 tcmu_setup_iovs(udev, tcmu_cmd, &iov, tcmu_cmd->data_len_bidi);
1108                 entry->req.iov_bidi_cnt = iov_bidi_cnt;
1109         }
1110
1111         tcmu_setup_cmd_timer(tcmu_cmd, udev->cmd_time_out, &udev->cmd_timer);
1112
1113         entry->hdr.cmd_id = tcmu_cmd->cmd_id;
1114
1115         tcmu_hdr_set_len(&entry->hdr.len_op, command_size);
1116
1117         /* All offsets relative to mb_addr, not start of entry! */
1118         cdb_off = CMDR_OFF + cmd_head + base_command_size;
1119         memcpy((void *) mb + cdb_off, se_cmd->t_task_cdb, scsi_command_size(se_cmd->t_task_cdb));
1120         entry->req.cdb_off = cdb_off;
1121         tcmu_flush_dcache_range(entry, command_size);
1122
1123         UPDATE_HEAD(mb->cmd_head, command_size, udev->cmdr_size);
1124         tcmu_flush_dcache_range(mb, sizeof(*mb));
1125
1126         list_add_tail(&tcmu_cmd->queue_entry, &udev->inflight_queue);
1127
1128         if (!test_bit(TCMU_DEV_BIT_PLUGGED, &udev->flags))
1129                 uio_event_notify(&udev->uio_info);
1130
1131         return 0;
1132
1133 free_and_queue:
1134         tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cur);
1135         tcmu_cmd_reset_dbi_cur(tcmu_cmd);
1136
1137 queue:
1138         if (add_to_qfull_queue(tcmu_cmd)) {
1139                 *scsi_err = TCM_OUT_OF_RESOURCES;
1140                 return -1;
1141         }
1142
1143         return 1;
1144 }
1145
1146 /**
1147  * queue_tmr_ring - queue tmr info to ring or internally
1148  * @udev: related tcmu_dev
1149  * @tmr: tcmu_tmr containing tmr info to queue
1150  *
1151  * Returns:
1152  *  0 success
1153  *  1 internally queued to wait for ring memory to free.
1154  */
1155 static int
1156 queue_tmr_ring(struct tcmu_dev *udev, struct tcmu_tmr *tmr)
1157 {
1158         struct tcmu_tmr_entry *entry;
1159         int cmd_size;
1160         int id_list_sz;
1161         struct tcmu_mailbox *mb = udev->mb_addr;
1162         uint32_t cmd_head;
1163
1164         if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags))
1165                 goto out_free;
1166
1167         id_list_sz = sizeof(tmr->tmr_cmd_ids[0]) * tmr->tmr_cmd_cnt;
1168         cmd_size = round_up(sizeof(*entry) + id_list_sz, TCMU_OP_ALIGN_SIZE);
1169
1170         if (!list_empty(&udev->tmr_queue) ||
1171             !is_ring_space_avail(udev, cmd_size)) {
1172                 list_add_tail(&tmr->queue_entry, &udev->tmr_queue);
1173                 pr_debug("adding tmr %p on dev %s to TMR ring space wait queue\n",
1174                          tmr, udev->name);
1175                 return 1;
1176         }
1177
1178         cmd_head = ring_insert_padding(udev, cmd_size);
1179
1180         entry = udev->cmdr + cmd_head;
1181         memset(entry, 0, cmd_size);
1182         tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_TMR);
1183         tcmu_hdr_set_len(&entry->hdr.len_op, cmd_size);
1184         entry->tmr_type = tmr->tmr_type;
1185         entry->cmd_cnt = tmr->tmr_cmd_cnt;
1186         memcpy(&entry->cmd_ids[0], &tmr->tmr_cmd_ids[0], id_list_sz);
1187         tcmu_flush_dcache_range(entry, cmd_size);
1188
1189         UPDATE_HEAD(mb->cmd_head, cmd_size, udev->cmdr_size);
1190         tcmu_flush_dcache_range(mb, sizeof(*mb));
1191
1192         uio_event_notify(&udev->uio_info);
1193
1194 out_free:
1195         kfree(tmr);
1196
1197         return 0;
1198 }
1199
1200 static sense_reason_t
1201 tcmu_queue_cmd(struct se_cmd *se_cmd)
1202 {
1203         struct se_device *se_dev = se_cmd->se_dev;
1204         struct tcmu_dev *udev = TCMU_DEV(se_dev);
1205         struct tcmu_cmd *tcmu_cmd;
1206         sense_reason_t scsi_ret = TCM_CHECK_CONDITION_ABORT_CMD;
1207         int ret = -1;
1208
1209         tcmu_cmd = tcmu_alloc_cmd(se_cmd);
1210         if (!tcmu_cmd)
1211                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1212
1213         mutex_lock(&udev->cmdr_lock);
1214         if (!(se_cmd->transport_state & CMD_T_ABORTED))
1215                 ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
1216         if (ret < 0)
1217                 tcmu_free_cmd(tcmu_cmd);
1218         else
1219                 se_cmd->priv = tcmu_cmd;
1220         mutex_unlock(&udev->cmdr_lock);
1221         return scsi_ret;
1222 }
1223
1224 static void tcmu_set_next_deadline(struct list_head *queue,
1225                                    struct timer_list *timer)
1226 {
1227         struct tcmu_cmd *cmd;
1228
1229         if (!list_empty(queue)) {
1230                 cmd = list_first_entry(queue, struct tcmu_cmd, queue_entry);
1231                 mod_timer(timer, cmd->deadline);
1232         } else
1233                 del_timer(timer);
1234 }
1235
1236 static int
1237 tcmu_tmr_type(enum tcm_tmreq_table tmf)
1238 {
1239         switch (tmf) {
1240         case TMR_ABORT_TASK:            return TCMU_TMR_ABORT_TASK;
1241         case TMR_ABORT_TASK_SET:        return TCMU_TMR_ABORT_TASK_SET;
1242         case TMR_CLEAR_ACA:             return TCMU_TMR_CLEAR_ACA;
1243         case TMR_CLEAR_TASK_SET:        return TCMU_TMR_CLEAR_TASK_SET;
1244         case TMR_LUN_RESET:             return TCMU_TMR_LUN_RESET;
1245         case TMR_TARGET_WARM_RESET:     return TCMU_TMR_TARGET_WARM_RESET;
1246         case TMR_TARGET_COLD_RESET:     return TCMU_TMR_TARGET_COLD_RESET;
1247         case TMR_LUN_RESET_PRO:         return TCMU_TMR_LUN_RESET_PRO;
1248         default:                        return TCMU_TMR_UNKNOWN;
1249         }
1250 }
1251
1252 static void
1253 tcmu_tmr_notify(struct se_device *se_dev, enum tcm_tmreq_table tmf,
1254                 struct list_head *cmd_list)
1255 {
1256         int i = 0, cmd_cnt = 0;
1257         bool unqueued = false;
1258         uint16_t *cmd_ids = NULL;
1259         struct tcmu_cmd *cmd;
1260         struct se_cmd *se_cmd;
1261         struct tcmu_tmr *tmr;
1262         struct tcmu_dev *udev = TCMU_DEV(se_dev);
1263
1264         mutex_lock(&udev->cmdr_lock);
1265
1266         /* First we check for aborted commands in qfull_queue */
1267         list_for_each_entry(se_cmd, cmd_list, state_list) {
1268                 i++;
1269                 if (!se_cmd->priv)
1270                         continue;
1271                 cmd = se_cmd->priv;
1272                 /* Commands on qfull queue have no id yet */
1273                 if (cmd->cmd_id) {
1274                         cmd_cnt++;
1275                         continue;
1276                 }
1277                 pr_debug("Removing aborted command %p from queue on dev %s.\n",
1278                          cmd, udev->name);
1279
1280                 list_del_init(&cmd->queue_entry);
1281                 tcmu_free_cmd(cmd);
1282                 se_cmd->priv = NULL;
1283                 target_complete_cmd(se_cmd, SAM_STAT_TASK_ABORTED);
1284                 unqueued = true;
1285         }
1286         if (unqueued)
1287                 tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
1288
1289         if (!test_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags))
1290                 goto unlock;
1291
1292         pr_debug("TMR event %d on dev %s, aborted cmds %d, afflicted cmd_ids %d\n",
1293                  tcmu_tmr_type(tmf), udev->name, i, cmd_cnt);
1294
1295         tmr = kmalloc(sizeof(*tmr) + cmd_cnt * sizeof(*cmd_ids), GFP_NOIO);
1296         if (!tmr)
1297                 goto unlock;
1298
1299         tmr->tmr_type = tcmu_tmr_type(tmf);
1300         tmr->tmr_cmd_cnt = cmd_cnt;
1301
1302         if (cmd_cnt != 0) {
1303                 cmd_cnt = 0;
1304                 list_for_each_entry(se_cmd, cmd_list, state_list) {
1305                         if (!se_cmd->priv)
1306                                 continue;
1307                         cmd = se_cmd->priv;
1308                         if (cmd->cmd_id)
1309                                 tmr->tmr_cmd_ids[cmd_cnt++] = cmd->cmd_id;
1310                 }
1311         }
1312
1313         queue_tmr_ring(udev, tmr);
1314
1315 unlock:
1316         mutex_unlock(&udev->cmdr_lock);
1317 }
1318
1319 static bool tcmu_handle_completion(struct tcmu_cmd *cmd,
1320                                    struct tcmu_cmd_entry *entry, bool keep_buf)
1321 {
1322         struct se_cmd *se_cmd = cmd->se_cmd;
1323         struct tcmu_dev *udev = cmd->tcmu_dev;
1324         bool read_len_valid = false;
1325         bool ret = true;
1326         uint32_t read_len;
1327
1328         /*
1329          * cmd has been completed already from timeout, just reclaim
1330          * data area space and free cmd
1331          */
1332         if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
1333                 WARN_ON_ONCE(se_cmd);
1334                 goto out;
1335         }
1336         if (test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags)) {
1337                 pr_err("cmd_id %u already completed with KEEP_BUF, ring is broken\n",
1338                        entry->hdr.cmd_id);
1339                 set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
1340                 ret = false;
1341                 goto out;
1342         }
1343
1344         list_del_init(&cmd->queue_entry);
1345
1346         tcmu_cmd_reset_dbi_cur(cmd);
1347
1348         if (entry->hdr.uflags & TCMU_UFLAG_UNKNOWN_OP) {
1349                 pr_warn("TCMU: Userspace set UNKNOWN_OP flag on se_cmd %p\n",
1350                         cmd->se_cmd);
1351                 entry->rsp.scsi_status = SAM_STAT_CHECK_CONDITION;
1352                 goto done;
1353         }
1354
1355         read_len = se_cmd->data_length;
1356         if (se_cmd->data_direction == DMA_FROM_DEVICE &&
1357             (entry->hdr.uflags & TCMU_UFLAG_READ_LEN) && entry->rsp.read_len) {
1358                 read_len_valid = true;
1359                 if (entry->rsp.read_len < read_len)
1360                         read_len = entry->rsp.read_len;
1361         }
1362
1363         if (entry->rsp.scsi_status == SAM_STAT_CHECK_CONDITION) {
1364                 transport_copy_sense_to_cmd(se_cmd, entry->rsp.sense_buffer);
1365                 if (!read_len_valid )
1366                         goto done;
1367                 else
1368                         se_cmd->se_cmd_flags |= SCF_TREAT_READ_AS_NORMAL;
1369         }
1370         if (se_cmd->se_cmd_flags & SCF_BIDI) {
1371                 /* Get Data-In buffer before clean up */
1372                 gather_data_area(udev, cmd, true, read_len);
1373         } else if (se_cmd->data_direction == DMA_FROM_DEVICE) {
1374                 gather_data_area(udev, cmd, false, read_len);
1375         } else if (se_cmd->data_direction == DMA_TO_DEVICE) {
1376                 /* TODO: */
1377         } else if (se_cmd->data_direction != DMA_NONE) {
1378                 pr_warn("TCMU: data direction was %d!\n",
1379                         se_cmd->data_direction);
1380         }
1381
1382 done:
1383         se_cmd->priv = NULL;
1384         if (read_len_valid) {
1385                 pr_debug("read_len = %d\n", read_len);
1386                 target_complete_cmd_with_length(cmd->se_cmd,
1387                                         entry->rsp.scsi_status, read_len);
1388         } else
1389                 target_complete_cmd(cmd->se_cmd, entry->rsp.scsi_status);
1390
1391 out:
1392         if (!keep_buf) {
1393                 tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
1394                 tcmu_free_cmd(cmd);
1395         } else {
1396                 /*
1397                  * Keep this command after completion, since userspace still
1398                  * needs the data buffer. Mark it with TCMU_CMD_BIT_KEEP_BUF
1399                  * and reset potential TCMU_CMD_BIT_EXPIRED, so we don't accept
1400                  * a second completion later.
1401                  * Userspace can free the buffer later by writing the cmd_id
1402                  * to new action attribute free_kept_buf.
1403                  */
1404                 clear_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags);
1405                 set_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags);
1406         }
1407         return ret;
1408 }
1409
1410 static int tcmu_run_tmr_queue(struct tcmu_dev *udev)
1411 {
1412         struct tcmu_tmr *tmr, *tmp;
1413         LIST_HEAD(tmrs);
1414
1415         if (list_empty(&udev->tmr_queue))
1416                 return 1;
1417
1418         pr_debug("running %s's tmr queue\n", udev->name);
1419
1420         list_splice_init(&udev->tmr_queue, &tmrs);
1421
1422         list_for_each_entry_safe(tmr, tmp, &tmrs, queue_entry) {
1423                 list_del_init(&tmr->queue_entry);
1424
1425                 pr_debug("removing tmr %p on dev %s from queue\n",
1426                          tmr, udev->name);
1427
1428                 if (queue_tmr_ring(udev, tmr)) {
1429                         pr_debug("ran out of space during tmr queue run\n");
1430                         /*
1431                          * tmr was requeued, so just put all tmrs back in
1432                          * the queue
1433                          */
1434                         list_splice_tail(&tmrs, &udev->tmr_queue);
1435                         return 0;
1436                 }
1437         }
1438
1439         return 1;
1440 }
1441
1442 static bool tcmu_handle_completions(struct tcmu_dev *udev)
1443 {
1444         struct tcmu_mailbox *mb;
1445         struct tcmu_cmd *cmd;
1446         bool free_space = false;
1447
1448         if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
1449                 pr_err("ring broken, not handling completions\n");
1450                 return false;
1451         }
1452
1453         mb = udev->mb_addr;
1454         tcmu_flush_dcache_range(mb, sizeof(*mb));
1455
1456         while (udev->cmdr_last_cleaned != READ_ONCE(mb->cmd_tail)) {
1457
1458                 struct tcmu_cmd_entry *entry = udev->cmdr + udev->cmdr_last_cleaned;
1459                 bool keep_buf;
1460
1461                 /*
1462                  * Flush max. up to end of cmd ring since current entry might
1463                  * be a padding that is shorter than sizeof(*entry)
1464                  */
1465                 size_t ring_left = head_to_end(udev->cmdr_last_cleaned,
1466                                                udev->cmdr_size);
1467                 tcmu_flush_dcache_range(entry, ring_left < sizeof(*entry) ?
1468                                         ring_left : sizeof(*entry));
1469
1470                 free_space = true;
1471
1472                 if (tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_PAD ||
1473                     tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_TMR) {
1474                         UPDATE_HEAD(udev->cmdr_last_cleaned,
1475                                     tcmu_hdr_get_len(entry->hdr.len_op),
1476                                     udev->cmdr_size);
1477                         continue;
1478                 }
1479                 WARN_ON(tcmu_hdr_get_op(entry->hdr.len_op) != TCMU_OP_CMD);
1480
1481                 keep_buf = !!(entry->hdr.uflags & TCMU_UFLAG_KEEP_BUF);
1482                 if (keep_buf)
1483                         cmd = xa_load(&udev->commands, entry->hdr.cmd_id);
1484                 else
1485                         cmd = xa_erase(&udev->commands, entry->hdr.cmd_id);
1486                 if (!cmd) {
1487                         pr_err("cmd_id %u not found, ring is broken\n",
1488                                entry->hdr.cmd_id);
1489                         set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
1490                         return false;
1491                 }
1492
1493                 if (!tcmu_handle_completion(cmd, entry, keep_buf))
1494                         break;
1495
1496                 UPDATE_HEAD(udev->cmdr_last_cleaned,
1497                             tcmu_hdr_get_len(entry->hdr.len_op),
1498                             udev->cmdr_size);
1499         }
1500         if (free_space)
1501                 free_space = tcmu_run_tmr_queue(udev);
1502
1503         if (atomic_read(&global_page_count) > tcmu_global_max_pages &&
1504             xa_empty(&udev->commands) && list_empty(&udev->qfull_queue)) {
1505                 /*
1506                  * Allocated blocks exceeded global block limit, currently no
1507                  * more pending or waiting commands so try to reclaim blocks.
1508                  */
1509                 schedule_delayed_work(&tcmu_unmap_work, 0);
1510         }
1511         if (udev->cmd_time_out)
1512                 tcmu_set_next_deadline(&udev->inflight_queue, &udev->cmd_timer);
1513
1514         return free_space;
1515 }
1516
1517 static void tcmu_check_expired_ring_cmd(struct tcmu_cmd *cmd)
1518 {
1519         struct se_cmd *se_cmd;
1520
1521         if (!time_after_eq(jiffies, cmd->deadline))
1522                 return;
1523
1524         set_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags);
1525         list_del_init(&cmd->queue_entry);
1526         se_cmd = cmd->se_cmd;
1527         se_cmd->priv = NULL;
1528         cmd->se_cmd = NULL;
1529
1530         pr_debug("Timing out inflight cmd %u on dev %s.\n",
1531                  cmd->cmd_id, cmd->tcmu_dev->name);
1532
1533         target_complete_cmd(se_cmd, SAM_STAT_CHECK_CONDITION);
1534 }
1535
1536 static void tcmu_check_expired_queue_cmd(struct tcmu_cmd *cmd)
1537 {
1538         struct se_cmd *se_cmd;
1539
1540         if (!time_after_eq(jiffies, cmd->deadline))
1541                 return;
1542
1543         pr_debug("Timing out queued cmd %p on dev %s.\n",
1544                   cmd, cmd->tcmu_dev->name);
1545
1546         list_del_init(&cmd->queue_entry);
1547         se_cmd = cmd->se_cmd;
1548         tcmu_free_cmd(cmd);
1549
1550         se_cmd->priv = NULL;
1551         target_complete_cmd(se_cmd, SAM_STAT_TASK_SET_FULL);
1552 }
1553
1554 static void tcmu_device_timedout(struct tcmu_dev *udev)
1555 {
1556         spin_lock(&timed_out_udevs_lock);
1557         if (list_empty(&udev->timedout_entry))
1558                 list_add_tail(&udev->timedout_entry, &timed_out_udevs);
1559         spin_unlock(&timed_out_udevs_lock);
1560
1561         schedule_delayed_work(&tcmu_unmap_work, 0);
1562 }
1563
1564 static void tcmu_cmd_timedout(struct timer_list *t)
1565 {
1566         struct tcmu_dev *udev = from_timer(udev, t, cmd_timer);
1567
1568         pr_debug("%s cmd timeout has expired\n", udev->name);
1569         tcmu_device_timedout(udev);
1570 }
1571
1572 static void tcmu_qfull_timedout(struct timer_list *t)
1573 {
1574         struct tcmu_dev *udev = from_timer(udev, t, qfull_timer);
1575
1576         pr_debug("%s qfull timeout has expired\n", udev->name);
1577         tcmu_device_timedout(udev);
1578 }
1579
1580 static int tcmu_attach_hba(struct se_hba *hba, u32 host_id)
1581 {
1582         struct tcmu_hba *tcmu_hba;
1583
1584         tcmu_hba = kzalloc(sizeof(struct tcmu_hba), GFP_KERNEL);
1585         if (!tcmu_hba)
1586                 return -ENOMEM;
1587
1588         tcmu_hba->host_id = host_id;
1589         hba->hba_ptr = tcmu_hba;
1590
1591         return 0;
1592 }
1593
1594 static void tcmu_detach_hba(struct se_hba *hba)
1595 {
1596         kfree(hba->hba_ptr);
1597         hba->hba_ptr = NULL;
1598 }
1599
1600 static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name)
1601 {
1602         struct tcmu_dev *udev;
1603
1604         udev = kzalloc(sizeof(struct tcmu_dev), GFP_KERNEL);
1605         if (!udev)
1606                 return NULL;
1607         kref_init(&udev->kref);
1608
1609         udev->name = kstrdup(name, GFP_KERNEL);
1610         if (!udev->name) {
1611                 kfree(udev);
1612                 return NULL;
1613         }
1614
1615         udev->hba = hba;
1616         udev->cmd_time_out = TCMU_TIME_OUT;
1617         udev->qfull_time_out = -1;
1618
1619         udev->data_pages_per_blk = DATA_PAGES_PER_BLK_DEF;
1620         udev->max_blocks = DATA_AREA_PAGES_DEF / udev->data_pages_per_blk;
1621         udev->data_area_mb = TCMU_PAGES_TO_MBS(DATA_AREA_PAGES_DEF);
1622
1623         mutex_init(&udev->cmdr_lock);
1624
1625         INIT_LIST_HEAD(&udev->node);
1626         INIT_LIST_HEAD(&udev->timedout_entry);
1627         INIT_LIST_HEAD(&udev->qfull_queue);
1628         INIT_LIST_HEAD(&udev->tmr_queue);
1629         INIT_LIST_HEAD(&udev->inflight_queue);
1630         xa_init_flags(&udev->commands, XA_FLAGS_ALLOC1);
1631
1632         timer_setup(&udev->qfull_timer, tcmu_qfull_timedout, 0);
1633         timer_setup(&udev->cmd_timer, tcmu_cmd_timedout, 0);
1634
1635         xa_init(&udev->data_pages);
1636
1637         return &udev->se_dev;
1638 }
1639
1640 static void tcmu_dev_call_rcu(struct rcu_head *p)
1641 {
1642         struct se_device *dev = container_of(p, struct se_device, rcu_head);
1643         struct tcmu_dev *udev = TCMU_DEV(dev);
1644
1645         kfree(udev->uio_info.name);
1646         kfree(udev->name);
1647         kfree(udev);
1648 }
1649
1650 static int tcmu_check_and_free_pending_cmd(struct tcmu_cmd *cmd)
1651 {
1652         if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags) ||
1653             test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags)) {
1654                 kmem_cache_free(tcmu_cmd_cache, cmd);
1655                 return 0;
1656         }
1657         return -EINVAL;
1658 }
1659
1660 static u32 tcmu_blocks_release(struct tcmu_dev *udev, unsigned long first,
1661                                 unsigned long last)
1662 {
1663         XA_STATE(xas, &udev->data_pages, first * udev->data_pages_per_blk);
1664         struct page *page;
1665         u32 pages_freed = 0;
1666
1667         xas_lock(&xas);
1668         xas_for_each(&xas, page, (last + 1) * udev->data_pages_per_blk - 1) {
1669                 xas_store(&xas, NULL);
1670                 __free_page(page);
1671                 pages_freed++;
1672         }
1673         xas_unlock(&xas);
1674
1675         atomic_sub(pages_freed, &global_page_count);
1676
1677         return pages_freed;
1678 }
1679
1680 static void tcmu_remove_all_queued_tmr(struct tcmu_dev *udev)
1681 {
1682         struct tcmu_tmr *tmr, *tmp;
1683
1684         list_for_each_entry_safe(tmr, tmp, &udev->tmr_queue, queue_entry) {
1685                 list_del_init(&tmr->queue_entry);
1686                 kfree(tmr);
1687         }
1688 }
1689
1690 static void tcmu_dev_kref_release(struct kref *kref)
1691 {
1692         struct tcmu_dev *udev = container_of(kref, struct tcmu_dev, kref);
1693         struct se_device *dev = &udev->se_dev;
1694         struct tcmu_cmd *cmd;
1695         bool all_expired = true;
1696         unsigned long i;
1697
1698         vfree(udev->mb_addr);
1699         udev->mb_addr = NULL;
1700
1701         spin_lock_bh(&timed_out_udevs_lock);
1702         if (!list_empty(&udev->timedout_entry))
1703                 list_del(&udev->timedout_entry);
1704         spin_unlock_bh(&timed_out_udevs_lock);
1705
1706         /* Upper layer should drain all requests before calling this */
1707         mutex_lock(&udev->cmdr_lock);
1708         xa_for_each(&udev->commands, i, cmd) {
1709                 if (tcmu_check_and_free_pending_cmd(cmd) != 0)
1710                         all_expired = false;
1711         }
1712         /* There can be left over TMR cmds. Remove them. */
1713         tcmu_remove_all_queued_tmr(udev);
1714         if (!list_empty(&udev->qfull_queue))
1715                 all_expired = false;
1716         xa_destroy(&udev->commands);
1717         WARN_ON(!all_expired);
1718
1719         tcmu_blocks_release(udev, 0, udev->dbi_max);
1720         bitmap_free(udev->data_bitmap);
1721         mutex_unlock(&udev->cmdr_lock);
1722
1723         pr_debug("dev_kref_release\n");
1724
1725         call_rcu(&dev->rcu_head, tcmu_dev_call_rcu);
1726 }
1727
1728 static void run_qfull_queue(struct tcmu_dev *udev, bool fail)
1729 {
1730         struct tcmu_cmd *tcmu_cmd, *tmp_cmd;
1731         LIST_HEAD(cmds);
1732         sense_reason_t scsi_ret;
1733         int ret;
1734
1735         if (list_empty(&udev->qfull_queue))
1736                 return;
1737
1738         pr_debug("running %s's cmdr queue forcefail %d\n", udev->name, fail);
1739
1740         list_splice_init(&udev->qfull_queue, &cmds);
1741
1742         list_for_each_entry_safe(tcmu_cmd, tmp_cmd, &cmds, queue_entry) {
1743                 list_del_init(&tcmu_cmd->queue_entry);
1744
1745                 pr_debug("removing cmd %p on dev %s from queue\n",
1746                          tcmu_cmd, udev->name);
1747
1748                 if (fail) {
1749                         /*
1750                          * We were not able to even start the command, so
1751                          * fail with busy to allow a retry in case runner
1752                          * was only temporarily down. If the device is being
1753                          * removed then LIO core will do the right thing and
1754                          * fail the retry.
1755                          */
1756                         tcmu_cmd->se_cmd->priv = NULL;
1757                         target_complete_cmd(tcmu_cmd->se_cmd, SAM_STAT_BUSY);
1758                         tcmu_free_cmd(tcmu_cmd);
1759                         continue;
1760                 }
1761
1762                 ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
1763                 if (ret < 0) {
1764                         pr_debug("cmd %p on dev %s failed with %u\n",
1765                                  tcmu_cmd, udev->name, scsi_ret);
1766                         /*
1767                          * Ignore scsi_ret for now. target_complete_cmd
1768                          * drops it.
1769                          */
1770                         tcmu_cmd->se_cmd->priv = NULL;
1771                         target_complete_cmd(tcmu_cmd->se_cmd,
1772                                             SAM_STAT_CHECK_CONDITION);
1773                         tcmu_free_cmd(tcmu_cmd);
1774                 } else if (ret > 0) {
1775                         pr_debug("ran out of space during cmdr queue run\n");
1776                         /*
1777                          * cmd was requeued, so just put all cmds back in
1778                          * the queue
1779                          */
1780                         list_splice_tail(&cmds, &udev->qfull_queue);
1781                         break;
1782                 }
1783         }
1784
1785         tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
1786 }
1787
1788 static int tcmu_irqcontrol(struct uio_info *info, s32 irq_on)
1789 {
1790         struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1791
1792         mutex_lock(&udev->cmdr_lock);
1793         if (tcmu_handle_completions(udev))
1794                 run_qfull_queue(udev, false);
1795         mutex_unlock(&udev->cmdr_lock);
1796
1797         return 0;
1798 }
1799
1800 /*
1801  * mmap code from uio.c. Copied here because we want to hook mmap()
1802  * and this stuff must come along.
1803  */
1804 static int tcmu_find_mem_index(struct vm_area_struct *vma)
1805 {
1806         struct tcmu_dev *udev = vma->vm_private_data;
1807         struct uio_info *info = &udev->uio_info;
1808
1809         if (vma->vm_pgoff < MAX_UIO_MAPS) {
1810                 if (info->mem[vma->vm_pgoff].size == 0)
1811                         return -1;
1812                 return (int)vma->vm_pgoff;
1813         }
1814         return -1;
1815 }
1816
1817 static struct page *tcmu_try_get_data_page(struct tcmu_dev *udev, uint32_t dpi)
1818 {
1819         struct page *page;
1820
1821         mutex_lock(&udev->cmdr_lock);
1822         page = xa_load(&udev->data_pages, dpi);
1823         if (likely(page)) {
1824                 mutex_unlock(&udev->cmdr_lock);
1825                 return page;
1826         }
1827
1828         /*
1829          * Userspace messed up and passed in a address not in the
1830          * data iov passed to it.
1831          */
1832         pr_err("Invalid addr to data page mapping (dpi %u) on device %s\n",
1833                dpi, udev->name);
1834         mutex_unlock(&udev->cmdr_lock);
1835
1836         return NULL;
1837 }
1838
1839 static void tcmu_vma_open(struct vm_area_struct *vma)
1840 {
1841         struct tcmu_dev *udev = vma->vm_private_data;
1842
1843         pr_debug("vma_open\n");
1844
1845         kref_get(&udev->kref);
1846 }
1847
1848 static void tcmu_vma_close(struct vm_area_struct *vma)
1849 {
1850         struct tcmu_dev *udev = vma->vm_private_data;
1851
1852         pr_debug("vma_close\n");
1853
1854         /* release ref from tcmu_vma_open */
1855         kref_put(&udev->kref, tcmu_dev_kref_release);
1856 }
1857
1858 static vm_fault_t tcmu_vma_fault(struct vm_fault *vmf)
1859 {
1860         struct tcmu_dev *udev = vmf->vma->vm_private_data;
1861         struct uio_info *info = &udev->uio_info;
1862         struct page *page;
1863         unsigned long offset;
1864         void *addr;
1865
1866         int mi = tcmu_find_mem_index(vmf->vma);
1867         if (mi < 0)
1868                 return VM_FAULT_SIGBUS;
1869
1870         /*
1871          * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
1872          * to use mem[N].
1873          */
1874         offset = (vmf->pgoff - mi) << PAGE_SHIFT;
1875
1876         if (offset < udev->data_off) {
1877                 /* For the vmalloc()ed cmd area pages */
1878                 addr = (void *)(unsigned long)info->mem[mi].addr + offset;
1879                 page = vmalloc_to_page(addr);
1880         } else {
1881                 uint32_t dpi;
1882
1883                 /* For the dynamically growing data area pages */
1884                 dpi = (offset - udev->data_off) / PAGE_SIZE;
1885                 page = tcmu_try_get_data_page(udev, dpi);
1886                 if (!page)
1887                         return VM_FAULT_SIGBUS;
1888         }
1889
1890         get_page(page);
1891         vmf->page = page;
1892         return 0;
1893 }
1894
1895 static const struct vm_operations_struct tcmu_vm_ops = {
1896         .open = tcmu_vma_open,
1897         .close = tcmu_vma_close,
1898         .fault = tcmu_vma_fault,
1899 };
1900
1901 static int tcmu_mmap(struct uio_info *info, struct vm_area_struct *vma)
1902 {
1903         struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1904
1905         vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
1906         vma->vm_ops = &tcmu_vm_ops;
1907
1908         vma->vm_private_data = udev;
1909
1910         /* Ensure the mmap is exactly the right size */
1911         if (vma_pages(vma) != udev->mmap_pages)
1912                 return -EINVAL;
1913
1914         tcmu_vma_open(vma);
1915
1916         return 0;
1917 }
1918
1919 static int tcmu_open(struct uio_info *info, struct inode *inode)
1920 {
1921         struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1922
1923         /* O_EXCL not supported for char devs, so fake it? */
1924         if (test_and_set_bit(TCMU_DEV_BIT_OPEN, &udev->flags))
1925                 return -EBUSY;
1926
1927         udev->inode = inode;
1928
1929         pr_debug("open\n");
1930
1931         return 0;
1932 }
1933
1934 static int tcmu_release(struct uio_info *info, struct inode *inode)
1935 {
1936         struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1937         struct tcmu_cmd *cmd;
1938         unsigned long i;
1939         bool freed = false;
1940
1941         mutex_lock(&udev->cmdr_lock);
1942
1943         xa_for_each(&udev->commands, i, cmd) {
1944                 /* Cmds with KEEP_BUF set are no longer on the ring, but
1945                  * userspace still holds the data buffer. If userspace closes
1946                  * we implicitly free these cmds and buffers, since after new
1947                  * open the (new ?) userspace cannot find the cmd in the ring
1948                  * and thus never will release the buffer by writing cmd_id to
1949                  * free_kept_buf action attribute.
1950                  */
1951                 if (!test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags))
1952                         continue;
1953                 pr_debug("removing KEEP_BUF cmd %u on dev %s from ring\n",
1954                          cmd->cmd_id, udev->name);
1955                 freed = true;
1956
1957                 xa_erase(&udev->commands, i);
1958                 tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
1959                 tcmu_free_cmd(cmd);
1960         }
1961         /*
1962          * We only freed data space, not ring space. Therefore we dont call
1963          * run_tmr_queue, but call run_qfull_queue if tmr_list is empty.
1964          */
1965         if (freed && list_empty(&udev->tmr_queue))
1966                 run_qfull_queue(udev, false);
1967
1968         mutex_unlock(&udev->cmdr_lock);
1969
1970         clear_bit(TCMU_DEV_BIT_OPEN, &udev->flags);
1971
1972         pr_debug("close\n");
1973
1974         return 0;
1975 }
1976
1977 static int tcmu_init_genl_cmd_reply(struct tcmu_dev *udev, int cmd)
1978 {
1979         struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
1980
1981         if (!tcmu_kern_cmd_reply_supported)
1982                 return 0;
1983
1984         if (udev->nl_reply_supported <= 0)
1985                 return 0;
1986
1987         mutex_lock(&tcmu_nl_cmd_mutex);
1988
1989         if (tcmu_netlink_blocked) {
1990                 mutex_unlock(&tcmu_nl_cmd_mutex);
1991                 pr_warn("Failing nl cmd %d on %s. Interface is blocked.\n", cmd,
1992                         udev->name);
1993                 return -EAGAIN;
1994         }
1995
1996         if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
1997                 mutex_unlock(&tcmu_nl_cmd_mutex);
1998                 pr_warn("netlink cmd %d already executing on %s\n",
1999                          nl_cmd->cmd, udev->name);
2000                 return -EBUSY;
2001         }
2002
2003         memset(nl_cmd, 0, sizeof(*nl_cmd));
2004         nl_cmd->cmd = cmd;
2005         nl_cmd->udev = udev;
2006         init_completion(&nl_cmd->complete);
2007         INIT_LIST_HEAD(&nl_cmd->nl_list);
2008
2009         list_add_tail(&nl_cmd->nl_list, &tcmu_nl_cmd_list);
2010
2011         mutex_unlock(&tcmu_nl_cmd_mutex);
2012         return 0;
2013 }
2014
2015 static void tcmu_destroy_genl_cmd_reply(struct tcmu_dev *udev)
2016 {
2017         struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
2018
2019         if (!tcmu_kern_cmd_reply_supported)
2020                 return;
2021
2022         if (udev->nl_reply_supported <= 0)
2023                 return;
2024
2025         mutex_lock(&tcmu_nl_cmd_mutex);
2026
2027         list_del(&nl_cmd->nl_list);
2028         memset(nl_cmd, 0, sizeof(*nl_cmd));
2029
2030         mutex_unlock(&tcmu_nl_cmd_mutex);
2031 }
2032
2033 static int tcmu_wait_genl_cmd_reply(struct tcmu_dev *udev)
2034 {
2035         struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
2036         int ret;
2037
2038         if (!tcmu_kern_cmd_reply_supported)
2039                 return 0;
2040
2041         if (udev->nl_reply_supported <= 0)
2042                 return 0;
2043
2044         pr_debug("sleeping for nl reply\n");
2045         wait_for_completion(&nl_cmd->complete);
2046
2047         mutex_lock(&tcmu_nl_cmd_mutex);
2048         nl_cmd->cmd = TCMU_CMD_UNSPEC;
2049         ret = nl_cmd->status;
2050         mutex_unlock(&tcmu_nl_cmd_mutex);
2051
2052         return ret;
2053 }
2054
2055 static int tcmu_netlink_event_init(struct tcmu_dev *udev,
2056                                    enum tcmu_genl_cmd cmd,
2057                                    struct sk_buff **buf, void **hdr)
2058 {
2059         struct sk_buff *skb;
2060         void *msg_header;
2061         int ret = -ENOMEM;
2062
2063         skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2064         if (!skb)
2065                 return ret;
2066
2067         msg_header = genlmsg_put(skb, 0, 0, &tcmu_genl_family, 0, cmd);
2068         if (!msg_header)
2069                 goto free_skb;
2070
2071         ret = nla_put_string(skb, TCMU_ATTR_DEVICE, udev->uio_info.name);
2072         if (ret < 0)
2073                 goto free_skb;
2074
2075         ret = nla_put_u32(skb, TCMU_ATTR_MINOR, udev->uio_info.uio_dev->minor);
2076         if (ret < 0)
2077                 goto free_skb;
2078
2079         ret = nla_put_u32(skb, TCMU_ATTR_DEVICE_ID, udev->se_dev.dev_index);
2080         if (ret < 0)
2081                 goto free_skb;
2082
2083         *buf = skb;
2084         *hdr = msg_header;
2085         return ret;
2086
2087 free_skb:
2088         nlmsg_free(skb);
2089         return ret;
2090 }
2091
2092 static int tcmu_netlink_event_send(struct tcmu_dev *udev,
2093                                    enum tcmu_genl_cmd cmd,
2094                                    struct sk_buff *skb, void *msg_header)
2095 {
2096         int ret;
2097
2098         genlmsg_end(skb, msg_header);
2099
2100         ret = tcmu_init_genl_cmd_reply(udev, cmd);
2101         if (ret) {
2102                 nlmsg_free(skb);
2103                 return ret;
2104         }
2105
2106         ret = genlmsg_multicast_allns(&tcmu_genl_family, skb, 0,
2107                                       TCMU_MCGRP_CONFIG, GFP_KERNEL);
2108
2109         /* Wait during an add as the listener may not be up yet */
2110         if (ret == 0 ||
2111            (ret == -ESRCH && cmd == TCMU_CMD_ADDED_DEVICE))
2112                 return tcmu_wait_genl_cmd_reply(udev);
2113         else
2114                 tcmu_destroy_genl_cmd_reply(udev);
2115
2116         return ret;
2117 }
2118
2119 static int tcmu_send_dev_add_event(struct tcmu_dev *udev)
2120 {
2121         struct sk_buff *skb = NULL;
2122         void *msg_header = NULL;
2123         int ret = 0;
2124
2125         ret = tcmu_netlink_event_init(udev, TCMU_CMD_ADDED_DEVICE, &skb,
2126                                       &msg_header);
2127         if (ret < 0)
2128                 return ret;
2129         return tcmu_netlink_event_send(udev, TCMU_CMD_ADDED_DEVICE, skb,
2130                                        msg_header);
2131 }
2132
2133 static int tcmu_send_dev_remove_event(struct tcmu_dev *udev)
2134 {
2135         struct sk_buff *skb = NULL;
2136         void *msg_header = NULL;
2137         int ret = 0;
2138
2139         ret = tcmu_netlink_event_init(udev, TCMU_CMD_REMOVED_DEVICE,
2140                                       &skb, &msg_header);
2141         if (ret < 0)
2142                 return ret;
2143         return tcmu_netlink_event_send(udev, TCMU_CMD_REMOVED_DEVICE,
2144                                        skb, msg_header);
2145 }
2146
2147 static int tcmu_update_uio_info(struct tcmu_dev *udev)
2148 {
2149         struct tcmu_hba *hba = udev->hba->hba_ptr;
2150         struct uio_info *info;
2151         char *str;
2152
2153         info = &udev->uio_info;
2154
2155         if (udev->dev_config[0])
2156                 str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s/%s", hba->host_id,
2157                                 udev->name, udev->dev_config);
2158         else
2159                 str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s", hba->host_id,
2160                                 udev->name);
2161         if (!str)
2162                 return -ENOMEM;
2163
2164         /* If the old string exists, free it */
2165         kfree(info->name);
2166         info->name = str;
2167
2168         return 0;
2169 }
2170
2171 static int tcmu_configure_device(struct se_device *dev)
2172 {
2173         struct tcmu_dev *udev = TCMU_DEV(dev);
2174         struct uio_info *info;
2175         struct tcmu_mailbox *mb;
2176         size_t data_size;
2177         int ret = 0;
2178
2179         ret = tcmu_update_uio_info(udev);
2180         if (ret)
2181                 return ret;
2182
2183         info = &udev->uio_info;
2184
2185         mutex_lock(&udev->cmdr_lock);
2186         udev->data_bitmap = bitmap_zalloc(udev->max_blocks, GFP_KERNEL);
2187         mutex_unlock(&udev->cmdr_lock);
2188         if (!udev->data_bitmap) {
2189                 ret = -ENOMEM;
2190                 goto err_bitmap_alloc;
2191         }
2192
2193         mb = vzalloc(MB_CMDR_SIZE);
2194         if (!mb) {
2195                 ret = -ENOMEM;
2196                 goto err_vzalloc;
2197         }
2198
2199         /* mailbox fits in first part of CMDR space */
2200         udev->mb_addr = mb;
2201         udev->cmdr = (void *)mb + CMDR_OFF;
2202         udev->cmdr_size = CMDR_SIZE;
2203         udev->data_off = MB_CMDR_SIZE;
2204         data_size = TCMU_MBS_TO_PAGES(udev->data_area_mb) << PAGE_SHIFT;
2205         udev->mmap_pages = (data_size + MB_CMDR_SIZE) >> PAGE_SHIFT;
2206         udev->data_blk_size = udev->data_pages_per_blk * PAGE_SIZE;
2207         udev->dbi_thresh = 0; /* Default in Idle state */
2208
2209         /* Initialise the mailbox of the ring buffer */
2210         mb->version = TCMU_MAILBOX_VERSION;
2211         mb->flags = TCMU_MAILBOX_FLAG_CAP_OOOC |
2212                     TCMU_MAILBOX_FLAG_CAP_READ_LEN |
2213                     TCMU_MAILBOX_FLAG_CAP_TMR |
2214                     TCMU_MAILBOX_FLAG_CAP_KEEP_BUF;
2215         mb->cmdr_off = CMDR_OFF;
2216         mb->cmdr_size = udev->cmdr_size;
2217
2218         WARN_ON(!PAGE_ALIGNED(udev->data_off));
2219         WARN_ON(data_size % PAGE_SIZE);
2220
2221         info->version = __stringify(TCMU_MAILBOX_VERSION);
2222
2223         info->mem[0].name = "tcm-user command & data buffer";
2224         info->mem[0].addr = (phys_addr_t)(uintptr_t)udev->mb_addr;
2225         info->mem[0].size = data_size + MB_CMDR_SIZE;
2226         info->mem[0].memtype = UIO_MEM_NONE;
2227
2228         info->irqcontrol = tcmu_irqcontrol;
2229         info->irq = UIO_IRQ_CUSTOM;
2230
2231         info->mmap = tcmu_mmap;
2232         info->open = tcmu_open;
2233         info->release = tcmu_release;
2234
2235         ret = uio_register_device(tcmu_root_device, info);
2236         if (ret)
2237                 goto err_register;
2238
2239         /* User can set hw_block_size before enable the device */
2240         if (dev->dev_attrib.hw_block_size == 0)
2241                 dev->dev_attrib.hw_block_size = 512;
2242         /* Other attributes can be configured in userspace */
2243         if (!dev->dev_attrib.hw_max_sectors)
2244                 dev->dev_attrib.hw_max_sectors = 128;
2245         if (!dev->dev_attrib.emulate_write_cache)
2246                 dev->dev_attrib.emulate_write_cache = 0;
2247         dev->dev_attrib.hw_queue_depth = 128;
2248
2249         /* If user didn't explicitly disable netlink reply support, use
2250          * module scope setting.
2251          */
2252         if (udev->nl_reply_supported >= 0)
2253                 udev->nl_reply_supported = tcmu_kern_cmd_reply_supported;
2254
2255         /*
2256          * Get a ref incase userspace does a close on the uio device before
2257          * LIO has initiated tcmu_free_device.
2258          */
2259         kref_get(&udev->kref);
2260
2261         ret = tcmu_send_dev_add_event(udev);
2262         if (ret)
2263                 goto err_netlink;
2264
2265         mutex_lock(&root_udev_mutex);
2266         list_add(&udev->node, &root_udev);
2267         mutex_unlock(&root_udev_mutex);
2268
2269         return 0;
2270
2271 err_netlink:
2272         kref_put(&udev->kref, tcmu_dev_kref_release);
2273         uio_unregister_device(&udev->uio_info);
2274 err_register:
2275         vfree(udev->mb_addr);
2276         udev->mb_addr = NULL;
2277 err_vzalloc:
2278         bitmap_free(udev->data_bitmap);
2279         udev->data_bitmap = NULL;
2280 err_bitmap_alloc:
2281         kfree(info->name);
2282         info->name = NULL;
2283
2284         return ret;
2285 }
2286
2287 static void tcmu_free_device(struct se_device *dev)
2288 {
2289         struct tcmu_dev *udev = TCMU_DEV(dev);
2290
2291         /* release ref from init */
2292         kref_put(&udev->kref, tcmu_dev_kref_release);
2293 }
2294
2295 static void tcmu_destroy_device(struct se_device *dev)
2296 {
2297         struct tcmu_dev *udev = TCMU_DEV(dev);
2298
2299         del_timer_sync(&udev->cmd_timer);
2300         del_timer_sync(&udev->qfull_timer);
2301
2302         mutex_lock(&root_udev_mutex);
2303         list_del(&udev->node);
2304         mutex_unlock(&root_udev_mutex);
2305
2306         tcmu_send_dev_remove_event(udev);
2307
2308         uio_unregister_device(&udev->uio_info);
2309
2310         /* release ref from configure */
2311         kref_put(&udev->kref, tcmu_dev_kref_release);
2312 }
2313
2314 static void tcmu_unblock_dev(struct tcmu_dev *udev)
2315 {
2316         mutex_lock(&udev->cmdr_lock);
2317         clear_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags);
2318         mutex_unlock(&udev->cmdr_lock);
2319 }
2320
2321 static void tcmu_block_dev(struct tcmu_dev *udev)
2322 {
2323         mutex_lock(&udev->cmdr_lock);
2324
2325         if (test_and_set_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
2326                 goto unlock;
2327
2328         /* complete IO that has executed successfully */
2329         tcmu_handle_completions(udev);
2330         /* fail IO waiting to be queued */
2331         run_qfull_queue(udev, true);
2332
2333 unlock:
2334         mutex_unlock(&udev->cmdr_lock);
2335 }
2336
2337 static void tcmu_reset_ring(struct tcmu_dev *udev, u8 err_level)
2338 {
2339         struct tcmu_mailbox *mb;
2340         struct tcmu_cmd *cmd;
2341         unsigned long i;
2342
2343         mutex_lock(&udev->cmdr_lock);
2344
2345         xa_for_each(&udev->commands, i, cmd) {
2346                 pr_debug("removing cmd %u on dev %s from ring %s\n",
2347                          cmd->cmd_id, udev->name,
2348                          test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags) ?
2349                          "(is expired)" :
2350                          (test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags) ?
2351                          "(is keep buffer)" : ""));
2352
2353                 xa_erase(&udev->commands, i);
2354                 if (!test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags) &&
2355                     !test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags)) {
2356                         WARN_ON(!cmd->se_cmd);
2357                         list_del_init(&cmd->queue_entry);
2358                         cmd->se_cmd->priv = NULL;
2359                         if (err_level == 1) {
2360                                 /*
2361                                  * Userspace was not able to start the
2362                                  * command or it is retryable.
2363                                  */
2364                                 target_complete_cmd(cmd->se_cmd, SAM_STAT_BUSY);
2365                         } else {
2366                                 /* hard failure */
2367                                 target_complete_cmd(cmd->se_cmd,
2368                                                     SAM_STAT_CHECK_CONDITION);
2369                         }
2370                 }
2371                 tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
2372                 tcmu_free_cmd(cmd);
2373         }
2374
2375         mb = udev->mb_addr;
2376         tcmu_flush_dcache_range(mb, sizeof(*mb));
2377         pr_debug("mb last %u head %u tail %u\n", udev->cmdr_last_cleaned,
2378                  mb->cmd_tail, mb->cmd_head);
2379
2380         udev->cmdr_last_cleaned = 0;
2381         mb->cmd_tail = 0;
2382         mb->cmd_head = 0;
2383         tcmu_flush_dcache_range(mb, sizeof(*mb));
2384         clear_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
2385
2386         del_timer(&udev->cmd_timer);
2387
2388         /*
2389          * ring is empty and qfull queue never contains aborted commands.
2390          * So TMRs in tmr queue do not contain relevant cmd_ids.
2391          * After a ring reset userspace should do a fresh start, so
2392          * even LUN RESET message is no longer relevant.
2393          * Therefore remove all TMRs from qfull queue
2394          */
2395         tcmu_remove_all_queued_tmr(udev);
2396
2397         run_qfull_queue(udev, false);
2398
2399         mutex_unlock(&udev->cmdr_lock);
2400 }
2401
2402 enum {
2403         Opt_dev_config, Opt_dev_size, Opt_hw_block_size, Opt_hw_max_sectors,
2404         Opt_nl_reply_supported, Opt_max_data_area_mb, Opt_data_pages_per_blk,
2405         Opt_err,
2406 };
2407
2408 static match_table_t tokens = {
2409         {Opt_dev_config, "dev_config=%s"},
2410         {Opt_dev_size, "dev_size=%s"},
2411         {Opt_hw_block_size, "hw_block_size=%d"},
2412         {Opt_hw_max_sectors, "hw_max_sectors=%d"},
2413         {Opt_nl_reply_supported, "nl_reply_supported=%d"},
2414         {Opt_max_data_area_mb, "max_data_area_mb=%d"},
2415         {Opt_data_pages_per_blk, "data_pages_per_blk=%d"},
2416         {Opt_err, NULL}
2417 };
2418
2419 static int tcmu_set_dev_attrib(substring_t *arg, u32 *dev_attrib)
2420 {
2421         int val, ret;
2422
2423         ret = match_int(arg, &val);
2424         if (ret < 0) {
2425                 pr_err("match_int() failed for dev attrib. Error %d.\n",
2426                        ret);
2427                 return ret;
2428         }
2429
2430         if (val <= 0) {
2431                 pr_err("Invalid dev attrib value %d. Must be greater than zero.\n",
2432                        val);
2433                 return -EINVAL;
2434         }
2435         *dev_attrib = val;
2436         return 0;
2437 }
2438
2439 static int tcmu_set_max_blocks_param(struct tcmu_dev *udev, substring_t *arg)
2440 {
2441         int val, ret;
2442         uint32_t pages_per_blk = udev->data_pages_per_blk;
2443
2444         ret = match_int(arg, &val);
2445         if (ret < 0) {
2446                 pr_err("match_int() failed for max_data_area_mb=. Error %d.\n",
2447                        ret);
2448                 return ret;
2449         }
2450         if (val <= 0) {
2451                 pr_err("Invalid max_data_area %d.\n", val);
2452                 return -EINVAL;
2453         }
2454         if (val > TCMU_PAGES_TO_MBS(tcmu_global_max_pages)) {
2455                 pr_err("%d is too large. Adjusting max_data_area_mb to global limit of %u\n",
2456                        val, TCMU_PAGES_TO_MBS(tcmu_global_max_pages));
2457                 val = TCMU_PAGES_TO_MBS(tcmu_global_max_pages);
2458         }
2459         if (TCMU_MBS_TO_PAGES(val) < pages_per_blk) {
2460                 pr_err("Invalid max_data_area %d (%zu pages): smaller than data_pages_per_blk (%u pages).\n",
2461                        val, TCMU_MBS_TO_PAGES(val), pages_per_blk);
2462                 return -EINVAL;
2463         }
2464
2465         mutex_lock(&udev->cmdr_lock);
2466         if (udev->data_bitmap) {
2467                 pr_err("Cannot set max_data_area_mb after it has been enabled.\n");
2468                 ret = -EINVAL;
2469                 goto unlock;
2470         }
2471
2472         udev->data_area_mb = val;
2473         udev->max_blocks = TCMU_MBS_TO_PAGES(val) / pages_per_blk;
2474
2475 unlock:
2476         mutex_unlock(&udev->cmdr_lock);
2477         return ret;
2478 }
2479
2480 static int tcmu_set_data_pages_per_blk(struct tcmu_dev *udev, substring_t *arg)
2481 {
2482         int val, ret;
2483
2484         ret = match_int(arg, &val);
2485         if (ret < 0) {
2486                 pr_err("match_int() failed for data_pages_per_blk=. Error %d.\n",
2487                        ret);
2488                 return ret;
2489         }
2490
2491         if (val > TCMU_MBS_TO_PAGES(udev->data_area_mb)) {
2492                 pr_err("Invalid data_pages_per_blk %d: greater than max_data_area_mb %d -> %zd pages).\n",
2493                        val, udev->data_area_mb,
2494                        TCMU_MBS_TO_PAGES(udev->data_area_mb));
2495                 return -EINVAL;
2496         }
2497
2498         mutex_lock(&udev->cmdr_lock);
2499         if (udev->data_bitmap) {
2500                 pr_err("Cannot set data_pages_per_blk after it has been enabled.\n");
2501                 ret = -EINVAL;
2502                 goto unlock;
2503         }
2504
2505         udev->data_pages_per_blk = val;
2506         udev->max_blocks = TCMU_MBS_TO_PAGES(udev->data_area_mb) / val;
2507
2508 unlock:
2509         mutex_unlock(&udev->cmdr_lock);
2510         return ret;
2511 }
2512
2513 static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev,
2514                 const char *page, ssize_t count)
2515 {
2516         struct tcmu_dev *udev = TCMU_DEV(dev);
2517         char *orig, *ptr, *opts;
2518         substring_t args[MAX_OPT_ARGS];
2519         int ret = 0, token;
2520
2521         opts = kstrdup(page, GFP_KERNEL);
2522         if (!opts)
2523                 return -ENOMEM;
2524
2525         orig = opts;
2526
2527         while ((ptr = strsep(&opts, ",\n")) != NULL) {
2528                 if (!*ptr)
2529                         continue;
2530
2531                 token = match_token(ptr, tokens, args);
2532                 switch (token) {
2533                 case Opt_dev_config:
2534                         if (match_strlcpy(udev->dev_config, &args[0],
2535                                           TCMU_CONFIG_LEN) == 0) {
2536                                 ret = -EINVAL;
2537                                 break;
2538                         }
2539                         pr_debug("TCMU: Referencing Path: %s\n", udev->dev_config);
2540                         break;
2541                 case Opt_dev_size:
2542                         ret = match_u64(&args[0], &udev->dev_size);
2543                         if (ret < 0)
2544                                 pr_err("match_u64() failed for dev_size=. Error %d.\n",
2545                                        ret);
2546                         break;
2547                 case Opt_hw_block_size:
2548                         ret = tcmu_set_dev_attrib(&args[0],
2549                                         &(dev->dev_attrib.hw_block_size));
2550                         break;
2551                 case Opt_hw_max_sectors:
2552                         ret = tcmu_set_dev_attrib(&args[0],
2553                                         &(dev->dev_attrib.hw_max_sectors));
2554                         break;
2555                 case Opt_nl_reply_supported:
2556                         ret = match_int(&args[0], &udev->nl_reply_supported);
2557                         if (ret < 0)
2558                                 pr_err("match_int() failed for nl_reply_supported=. Error %d.\n",
2559                                        ret);
2560                         break;
2561                 case Opt_max_data_area_mb:
2562                         ret = tcmu_set_max_blocks_param(udev, &args[0]);
2563                         break;
2564                 case Opt_data_pages_per_blk:
2565                         ret = tcmu_set_data_pages_per_blk(udev, &args[0]);
2566                         break;
2567                 default:
2568                         break;
2569                 }
2570
2571                 if (ret)
2572                         break;
2573         }
2574
2575         kfree(orig);
2576         return (!ret) ? count : ret;
2577 }
2578
2579 static ssize_t tcmu_show_configfs_dev_params(struct se_device *dev, char *b)
2580 {
2581         struct tcmu_dev *udev = TCMU_DEV(dev);
2582         ssize_t bl = 0;
2583
2584         bl = sprintf(b + bl, "Config: %s ",
2585                      udev->dev_config[0] ? udev->dev_config : "NULL");
2586         bl += sprintf(b + bl, "Size: %llu ", udev->dev_size);
2587         bl += sprintf(b + bl, "MaxDataAreaMB: %u ", udev->data_area_mb);
2588         bl += sprintf(b + bl, "DataPagesPerBlk: %u\n", udev->data_pages_per_blk);
2589
2590         return bl;
2591 }
2592
2593 static sector_t tcmu_get_blocks(struct se_device *dev)
2594 {
2595         struct tcmu_dev *udev = TCMU_DEV(dev);
2596
2597         return div_u64(udev->dev_size - dev->dev_attrib.block_size,
2598                        dev->dev_attrib.block_size);
2599 }
2600
2601 static sense_reason_t
2602 tcmu_parse_cdb(struct se_cmd *cmd)
2603 {
2604         return passthrough_parse_cdb(cmd, tcmu_queue_cmd);
2605 }
2606
2607 static ssize_t tcmu_cmd_time_out_show(struct config_item *item, char *page)
2608 {
2609         struct se_dev_attrib *da = container_of(to_config_group(item),
2610                                         struct se_dev_attrib, da_group);
2611         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2612
2613         return snprintf(page, PAGE_SIZE, "%lu\n", udev->cmd_time_out / MSEC_PER_SEC);
2614 }
2615
2616 static ssize_t tcmu_cmd_time_out_store(struct config_item *item, const char *page,
2617                                        size_t count)
2618 {
2619         struct se_dev_attrib *da = container_of(to_config_group(item),
2620                                         struct se_dev_attrib, da_group);
2621         struct tcmu_dev *udev = container_of(da->da_dev,
2622                                         struct tcmu_dev, se_dev);
2623         u32 val;
2624         int ret;
2625
2626         if (da->da_dev->export_count) {
2627                 pr_err("Unable to set tcmu cmd_time_out while exports exist\n");
2628                 return -EINVAL;
2629         }
2630
2631         ret = kstrtou32(page, 0, &val);
2632         if (ret < 0)
2633                 return ret;
2634
2635         udev->cmd_time_out = val * MSEC_PER_SEC;
2636         return count;
2637 }
2638 CONFIGFS_ATTR(tcmu_, cmd_time_out);
2639
2640 static ssize_t tcmu_qfull_time_out_show(struct config_item *item, char *page)
2641 {
2642         struct se_dev_attrib *da = container_of(to_config_group(item),
2643                                                 struct se_dev_attrib, da_group);
2644         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2645
2646         return snprintf(page, PAGE_SIZE, "%ld\n", udev->qfull_time_out <= 0 ?
2647                         udev->qfull_time_out :
2648                         udev->qfull_time_out / MSEC_PER_SEC);
2649 }
2650
2651 static ssize_t tcmu_qfull_time_out_store(struct config_item *item,
2652                                          const char *page, size_t count)
2653 {
2654         struct se_dev_attrib *da = container_of(to_config_group(item),
2655                                         struct se_dev_attrib, da_group);
2656         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2657         s32 val;
2658         int ret;
2659
2660         ret = kstrtos32(page, 0, &val);
2661         if (ret < 0)
2662                 return ret;
2663
2664         if (val >= 0) {
2665                 udev->qfull_time_out = val * MSEC_PER_SEC;
2666         } else if (val == -1) {
2667                 udev->qfull_time_out = val;
2668         } else {
2669                 printk(KERN_ERR "Invalid qfull timeout value %d\n", val);
2670                 return -EINVAL;
2671         }
2672         return count;
2673 }
2674 CONFIGFS_ATTR(tcmu_, qfull_time_out);
2675
2676 static ssize_t tcmu_max_data_area_mb_show(struct config_item *item, char *page)
2677 {
2678         struct se_dev_attrib *da = container_of(to_config_group(item),
2679                                                 struct se_dev_attrib, da_group);
2680         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2681
2682         return snprintf(page, PAGE_SIZE, "%u\n", udev->data_area_mb);
2683 }
2684 CONFIGFS_ATTR_RO(tcmu_, max_data_area_mb);
2685
2686 static ssize_t tcmu_data_pages_per_blk_show(struct config_item *item,
2687                                             char *page)
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
2693         return snprintf(page, PAGE_SIZE, "%u\n", udev->data_pages_per_blk);
2694 }
2695 CONFIGFS_ATTR_RO(tcmu_, data_pages_per_blk);
2696
2697 static ssize_t tcmu_dev_config_show(struct config_item *item, char *page)
2698 {
2699         struct se_dev_attrib *da = container_of(to_config_group(item),
2700                                                 struct se_dev_attrib, da_group);
2701         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2702
2703         return snprintf(page, PAGE_SIZE, "%s\n", udev->dev_config);
2704 }
2705
2706 static int tcmu_send_dev_config_event(struct tcmu_dev *udev,
2707                                       const char *reconfig_data)
2708 {
2709         struct sk_buff *skb = NULL;
2710         void *msg_header = NULL;
2711         int ret = 0;
2712
2713         ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2714                                       &skb, &msg_header);
2715         if (ret < 0)
2716                 return ret;
2717         ret = nla_put_string(skb, TCMU_ATTR_DEV_CFG, reconfig_data);
2718         if (ret < 0) {
2719                 nlmsg_free(skb);
2720                 return ret;
2721         }
2722         return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2723                                        skb, msg_header);
2724 }
2725
2726
2727 static ssize_t tcmu_dev_config_store(struct config_item *item, const char *page,
2728                                      size_t count)
2729 {
2730         struct se_dev_attrib *da = container_of(to_config_group(item),
2731                                                 struct se_dev_attrib, da_group);
2732         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2733         int ret, len;
2734
2735         len = strlen(page);
2736         if (!len || len > TCMU_CONFIG_LEN - 1)
2737                 return -EINVAL;
2738
2739         /* Check if device has been configured before */
2740         if (target_dev_configured(&udev->se_dev)) {
2741                 ret = tcmu_send_dev_config_event(udev, page);
2742                 if (ret) {
2743                         pr_err("Unable to reconfigure device\n");
2744                         return ret;
2745                 }
2746                 strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2747
2748                 ret = tcmu_update_uio_info(udev);
2749                 if (ret)
2750                         return ret;
2751                 return count;
2752         }
2753         strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2754
2755         return count;
2756 }
2757 CONFIGFS_ATTR(tcmu_, dev_config);
2758
2759 static ssize_t tcmu_dev_size_show(struct config_item *item, char *page)
2760 {
2761         struct se_dev_attrib *da = container_of(to_config_group(item),
2762                                                 struct se_dev_attrib, da_group);
2763         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2764
2765         return snprintf(page, PAGE_SIZE, "%llu\n", udev->dev_size);
2766 }
2767
2768 static int tcmu_send_dev_size_event(struct tcmu_dev *udev, u64 size)
2769 {
2770         struct sk_buff *skb = NULL;
2771         void *msg_header = NULL;
2772         int ret = 0;
2773
2774         ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2775                                       &skb, &msg_header);
2776         if (ret < 0)
2777                 return ret;
2778         ret = nla_put_u64_64bit(skb, TCMU_ATTR_DEV_SIZE,
2779                                 size, TCMU_ATTR_PAD);
2780         if (ret < 0) {
2781                 nlmsg_free(skb);
2782                 return ret;
2783         }
2784         return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2785                                        skb, msg_header);
2786 }
2787
2788 static ssize_t tcmu_dev_size_store(struct config_item *item, const char *page,
2789                                    size_t count)
2790 {
2791         struct se_dev_attrib *da = container_of(to_config_group(item),
2792                                                 struct se_dev_attrib, da_group);
2793         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2794         u64 val;
2795         int ret;
2796
2797         ret = kstrtou64(page, 0, &val);
2798         if (ret < 0)
2799                 return ret;
2800
2801         /* Check if device has been configured before */
2802         if (target_dev_configured(&udev->se_dev)) {
2803                 ret = tcmu_send_dev_size_event(udev, val);
2804                 if (ret) {
2805                         pr_err("Unable to reconfigure device\n");
2806                         return ret;
2807                 }
2808         }
2809         udev->dev_size = val;
2810         return count;
2811 }
2812 CONFIGFS_ATTR(tcmu_, dev_size);
2813
2814 static ssize_t tcmu_nl_reply_supported_show(struct config_item *item,
2815                 char *page)
2816 {
2817         struct se_dev_attrib *da = container_of(to_config_group(item),
2818                                                 struct se_dev_attrib, da_group);
2819         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2820
2821         return snprintf(page, PAGE_SIZE, "%d\n", udev->nl_reply_supported);
2822 }
2823
2824 static ssize_t tcmu_nl_reply_supported_store(struct config_item *item,
2825                 const char *page, size_t count)
2826 {
2827         struct se_dev_attrib *da = container_of(to_config_group(item),
2828                                                 struct se_dev_attrib, da_group);
2829         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2830         s8 val;
2831         int ret;
2832
2833         ret = kstrtos8(page, 0, &val);
2834         if (ret < 0)
2835                 return ret;
2836
2837         udev->nl_reply_supported = val;
2838         return count;
2839 }
2840 CONFIGFS_ATTR(tcmu_, nl_reply_supported);
2841
2842 static ssize_t tcmu_emulate_write_cache_show(struct config_item *item,
2843                                              char *page)
2844 {
2845         struct se_dev_attrib *da = container_of(to_config_group(item),
2846                                         struct se_dev_attrib, da_group);
2847
2848         return snprintf(page, PAGE_SIZE, "%i\n", da->emulate_write_cache);
2849 }
2850
2851 static int tcmu_send_emulate_write_cache(struct tcmu_dev *udev, u8 val)
2852 {
2853         struct sk_buff *skb = NULL;
2854         void *msg_header = NULL;
2855         int ret = 0;
2856
2857         ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2858                                       &skb, &msg_header);
2859         if (ret < 0)
2860                 return ret;
2861         ret = nla_put_u8(skb, TCMU_ATTR_WRITECACHE, val);
2862         if (ret < 0) {
2863                 nlmsg_free(skb);
2864                 return ret;
2865         }
2866         return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2867                                        skb, msg_header);
2868 }
2869
2870 static ssize_t tcmu_emulate_write_cache_store(struct config_item *item,
2871                                               const char *page, size_t count)
2872 {
2873         struct se_dev_attrib *da = container_of(to_config_group(item),
2874                                         struct se_dev_attrib, da_group);
2875         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2876         u8 val;
2877         int ret;
2878
2879         ret = kstrtou8(page, 0, &val);
2880         if (ret < 0)
2881                 return ret;
2882
2883         /* Check if device has been configured before */
2884         if (target_dev_configured(&udev->se_dev)) {
2885                 ret = tcmu_send_emulate_write_cache(udev, val);
2886                 if (ret) {
2887                         pr_err("Unable to reconfigure device\n");
2888                         return ret;
2889                 }
2890         }
2891
2892         da->emulate_write_cache = val;
2893         return count;
2894 }
2895 CONFIGFS_ATTR(tcmu_, emulate_write_cache);
2896
2897 static ssize_t tcmu_tmr_notification_show(struct config_item *item, char *page)
2898 {
2899         struct se_dev_attrib *da = container_of(to_config_group(item),
2900                                         struct se_dev_attrib, da_group);
2901         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2902
2903         return snprintf(page, PAGE_SIZE, "%i\n",
2904                         test_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags));
2905 }
2906
2907 static ssize_t tcmu_tmr_notification_store(struct config_item *item,
2908                                            const char *page, size_t count)
2909 {
2910         struct se_dev_attrib *da = container_of(to_config_group(item),
2911                                         struct se_dev_attrib, da_group);
2912         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2913         u8 val;
2914         int ret;
2915
2916         ret = kstrtou8(page, 0, &val);
2917         if (ret < 0)
2918                 return ret;
2919         if (val > 1)
2920                 return -EINVAL;
2921
2922         if (val)
2923                 set_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags);
2924         else
2925                 clear_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags);
2926         return count;
2927 }
2928 CONFIGFS_ATTR(tcmu_, tmr_notification);
2929
2930 static ssize_t tcmu_block_dev_show(struct config_item *item, char *page)
2931 {
2932         struct se_device *se_dev = container_of(to_config_group(item),
2933                                                 struct se_device,
2934                                                 dev_action_group);
2935         struct tcmu_dev *udev = TCMU_DEV(se_dev);
2936
2937         if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
2938                 return snprintf(page, PAGE_SIZE, "%s\n", "blocked");
2939         else
2940                 return snprintf(page, PAGE_SIZE, "%s\n", "unblocked");
2941 }
2942
2943 static ssize_t tcmu_block_dev_store(struct config_item *item, const char *page,
2944                                     size_t count)
2945 {
2946         struct se_device *se_dev = container_of(to_config_group(item),
2947                                                 struct se_device,
2948                                                 dev_action_group);
2949         struct tcmu_dev *udev = TCMU_DEV(se_dev);
2950         u8 val;
2951         int ret;
2952
2953         if (!target_dev_configured(&udev->se_dev)) {
2954                 pr_err("Device is not configured.\n");
2955                 return -EINVAL;
2956         }
2957
2958         ret = kstrtou8(page, 0, &val);
2959         if (ret < 0)
2960                 return ret;
2961
2962         if (val > 1) {
2963                 pr_err("Invalid block value %d\n", val);
2964                 return -EINVAL;
2965         }
2966
2967         if (!val)
2968                 tcmu_unblock_dev(udev);
2969         else
2970                 tcmu_block_dev(udev);
2971         return count;
2972 }
2973 CONFIGFS_ATTR(tcmu_, block_dev);
2974
2975 static ssize_t tcmu_reset_ring_store(struct config_item *item, const char *page,
2976                                      size_t count)
2977 {
2978         struct se_device *se_dev = container_of(to_config_group(item),
2979                                                 struct se_device,
2980                                                 dev_action_group);
2981         struct tcmu_dev *udev = TCMU_DEV(se_dev);
2982         u8 val;
2983         int ret;
2984
2985         if (!target_dev_configured(&udev->se_dev)) {
2986                 pr_err("Device is not configured.\n");
2987                 return -EINVAL;
2988         }
2989
2990         ret = kstrtou8(page, 0, &val);
2991         if (ret < 0)
2992                 return ret;
2993
2994         if (val != 1 && val != 2) {
2995                 pr_err("Invalid reset ring value %d\n", val);
2996                 return -EINVAL;
2997         }
2998
2999         tcmu_reset_ring(udev, val);
3000         return count;
3001 }
3002 CONFIGFS_ATTR_WO(tcmu_, reset_ring);
3003
3004 static ssize_t tcmu_free_kept_buf_store(struct config_item *item, const char *page,
3005                                         size_t count)
3006 {
3007         struct se_device *se_dev = container_of(to_config_group(item),
3008                                                 struct se_device,
3009                                                 dev_action_group);
3010         struct tcmu_dev *udev = TCMU_DEV(se_dev);
3011         struct tcmu_cmd *cmd;
3012         u16 cmd_id;
3013         int ret;
3014
3015         if (!target_dev_configured(&udev->se_dev)) {
3016                 pr_err("Device is not configured.\n");
3017                 return -EINVAL;
3018         }
3019
3020         ret = kstrtou16(page, 0, &cmd_id);
3021         if (ret < 0)
3022                 return ret;
3023
3024         mutex_lock(&udev->cmdr_lock);
3025
3026         {
3027                 XA_STATE(xas, &udev->commands, cmd_id);
3028
3029                 xas_lock(&xas);
3030                 cmd = xas_load(&xas);
3031                 if (!cmd) {
3032                         pr_err("free_kept_buf: cmd_id %d not found\n", cmd_id);
3033                         count = -EINVAL;
3034                         xas_unlock(&xas);
3035                         goto out_unlock;
3036                 }
3037                 if (!test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags)) {
3038                         pr_err("free_kept_buf: cmd_id %d was not completed with KEEP_BUF\n",
3039                                cmd_id);
3040                         count = -EINVAL;
3041                         xas_unlock(&xas);
3042                         goto out_unlock;
3043                 }
3044                 xas_store(&xas, NULL);
3045                 xas_unlock(&xas);
3046         }
3047
3048         tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
3049         tcmu_free_cmd(cmd);
3050         /*
3051          * We only freed data space, not ring space. Therefore we dont call
3052          * run_tmr_queue, but call run_qfull_queue if tmr_list is empty.
3053          */
3054         if (list_empty(&udev->tmr_queue))
3055                 run_qfull_queue(udev, false);
3056
3057 out_unlock:
3058         mutex_unlock(&udev->cmdr_lock);
3059         return count;
3060 }
3061 CONFIGFS_ATTR_WO(tcmu_, free_kept_buf);
3062
3063 static struct configfs_attribute *tcmu_attrib_attrs[] = {
3064         &tcmu_attr_cmd_time_out,
3065         &tcmu_attr_qfull_time_out,
3066         &tcmu_attr_max_data_area_mb,
3067         &tcmu_attr_data_pages_per_blk,
3068         &tcmu_attr_dev_config,
3069         &tcmu_attr_dev_size,
3070         &tcmu_attr_emulate_write_cache,
3071         &tcmu_attr_tmr_notification,
3072         &tcmu_attr_nl_reply_supported,
3073         NULL,
3074 };
3075
3076 static struct configfs_attribute **tcmu_attrs;
3077
3078 static struct configfs_attribute *tcmu_action_attrs[] = {
3079         &tcmu_attr_block_dev,
3080         &tcmu_attr_reset_ring,
3081         &tcmu_attr_free_kept_buf,
3082         NULL,
3083 };
3084
3085 static struct target_backend_ops tcmu_ops = {
3086         .name                   = "user",
3087         .owner                  = THIS_MODULE,
3088         .transport_flags_default = TRANSPORT_FLAG_PASSTHROUGH,
3089         .transport_flags_changeable = TRANSPORT_FLAG_PASSTHROUGH_PGR |
3090                                       TRANSPORT_FLAG_PASSTHROUGH_ALUA,
3091         .attach_hba             = tcmu_attach_hba,
3092         .detach_hba             = tcmu_detach_hba,
3093         .alloc_device           = tcmu_alloc_device,
3094         .configure_device       = tcmu_configure_device,
3095         .destroy_device         = tcmu_destroy_device,
3096         .free_device            = tcmu_free_device,
3097         .unplug_device          = tcmu_unplug_device,
3098         .plug_device            = tcmu_plug_device,
3099         .parse_cdb              = tcmu_parse_cdb,
3100         .tmr_notify             = tcmu_tmr_notify,
3101         .set_configfs_dev_params = tcmu_set_configfs_dev_params,
3102         .show_configfs_dev_params = tcmu_show_configfs_dev_params,
3103         .get_device_type        = sbc_get_device_type,
3104         .get_blocks             = tcmu_get_blocks,
3105         .tb_dev_action_attrs    = tcmu_action_attrs,
3106 };
3107
3108 static void find_free_blocks(void)
3109 {
3110         struct tcmu_dev *udev;
3111         loff_t off;
3112         u32 pages_freed, total_pages_freed = 0;
3113         u32 start, end, block, total_blocks_freed = 0;
3114
3115         if (atomic_read(&global_page_count) <= tcmu_global_max_pages)
3116                 return;
3117
3118         mutex_lock(&root_udev_mutex);
3119         list_for_each_entry(udev, &root_udev, node) {
3120                 mutex_lock(&udev->cmdr_lock);
3121
3122                 if (!target_dev_configured(&udev->se_dev)) {
3123                         mutex_unlock(&udev->cmdr_lock);
3124                         continue;
3125                 }
3126
3127                 /* Try to complete the finished commands first */
3128                 if (tcmu_handle_completions(udev))
3129                         run_qfull_queue(udev, false);
3130
3131                 /* Skip the udevs in idle */
3132                 if (!udev->dbi_thresh) {
3133                         mutex_unlock(&udev->cmdr_lock);
3134                         continue;
3135                 }
3136
3137                 end = udev->dbi_max + 1;
3138                 block = find_last_bit(udev->data_bitmap, end);
3139                 if (block == udev->dbi_max) {
3140                         /*
3141                          * The last bit is dbi_max, so it is not possible
3142                          * reclaim any blocks.
3143                          */
3144                         mutex_unlock(&udev->cmdr_lock);
3145                         continue;
3146                 } else if (block == end) {
3147                         /* The current udev will goto idle state */
3148                         udev->dbi_thresh = start = 0;
3149                         udev->dbi_max = 0;
3150                 } else {
3151                         udev->dbi_thresh = start = block + 1;
3152                         udev->dbi_max = block;
3153                 }
3154
3155                 /* Here will truncate the data area from off */
3156                 off = udev->data_off + (loff_t)start * udev->data_blk_size;
3157                 unmap_mapping_range(udev->inode->i_mapping, off, 0, 1);
3158
3159                 /* Release the block pages */
3160                 pages_freed = tcmu_blocks_release(udev, start, end - 1);
3161                 mutex_unlock(&udev->cmdr_lock);
3162
3163                 total_pages_freed += pages_freed;
3164                 total_blocks_freed += end - start;
3165                 pr_debug("Freed %u pages (total %u) from %u blocks (total %u) from %s.\n",
3166                          pages_freed, total_pages_freed, end - start,
3167                          total_blocks_freed, udev->name);
3168         }
3169         mutex_unlock(&root_udev_mutex);
3170
3171         if (atomic_read(&global_page_count) > tcmu_global_max_pages)
3172                 schedule_delayed_work(&tcmu_unmap_work, msecs_to_jiffies(5000));
3173 }
3174
3175 static void check_timedout_devices(void)
3176 {
3177         struct tcmu_dev *udev, *tmp_dev;
3178         struct tcmu_cmd *cmd, *tmp_cmd;
3179         LIST_HEAD(devs);
3180
3181         spin_lock_bh(&timed_out_udevs_lock);
3182         list_splice_init(&timed_out_udevs, &devs);
3183
3184         list_for_each_entry_safe(udev, tmp_dev, &devs, timedout_entry) {
3185                 list_del_init(&udev->timedout_entry);
3186                 spin_unlock_bh(&timed_out_udevs_lock);
3187
3188                 mutex_lock(&udev->cmdr_lock);
3189
3190                 /*
3191                  * If cmd_time_out is disabled but qfull is set deadline
3192                  * will only reflect the qfull timeout. Ignore it.
3193                  */
3194                 if (udev->cmd_time_out) {
3195                         list_for_each_entry_safe(cmd, tmp_cmd,
3196                                                  &udev->inflight_queue,
3197                                                  queue_entry) {
3198                                 tcmu_check_expired_ring_cmd(cmd);
3199                         }
3200                         tcmu_set_next_deadline(&udev->inflight_queue,
3201                                                &udev->cmd_timer);
3202                 }
3203                 list_for_each_entry_safe(cmd, tmp_cmd, &udev->qfull_queue,
3204                                          queue_entry) {
3205                         tcmu_check_expired_queue_cmd(cmd);
3206                 }
3207                 tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
3208
3209                 mutex_unlock(&udev->cmdr_lock);
3210
3211                 spin_lock_bh(&timed_out_udevs_lock);
3212         }
3213
3214         spin_unlock_bh(&timed_out_udevs_lock);
3215 }
3216
3217 static void tcmu_unmap_work_fn(struct work_struct *work)
3218 {
3219         check_timedout_devices();
3220         find_free_blocks();
3221 }
3222
3223 static int __init tcmu_module_init(void)
3224 {
3225         int ret, i, k, len = 0;
3226
3227         BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry) % TCMU_OP_ALIGN_SIZE) != 0);
3228
3229         INIT_DELAYED_WORK(&tcmu_unmap_work, tcmu_unmap_work_fn);
3230
3231         tcmu_cmd_cache = kmem_cache_create("tcmu_cmd_cache",
3232                                 sizeof(struct tcmu_cmd),
3233                                 __alignof__(struct tcmu_cmd),
3234                                 0, NULL);
3235         if (!tcmu_cmd_cache)
3236                 return -ENOMEM;
3237
3238         tcmu_root_device = root_device_register("tcm_user");
3239         if (IS_ERR(tcmu_root_device)) {
3240                 ret = PTR_ERR(tcmu_root_device);
3241                 goto out_free_cache;
3242         }
3243
3244         ret = genl_register_family(&tcmu_genl_family);
3245         if (ret < 0) {
3246                 goto out_unreg_device;
3247         }
3248
3249         for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
3250                 len += sizeof(struct configfs_attribute *);
3251         for (i = 0; passthrough_pr_attrib_attrs[i] != NULL; i++)
3252                 len += sizeof(struct configfs_attribute *);
3253         for (i = 0; tcmu_attrib_attrs[i] != NULL; i++)
3254                 len += sizeof(struct configfs_attribute *);
3255         len += sizeof(struct configfs_attribute *);
3256
3257         tcmu_attrs = kzalloc(len, GFP_KERNEL);
3258         if (!tcmu_attrs) {
3259                 ret = -ENOMEM;
3260                 goto out_unreg_genl;
3261         }
3262
3263         for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
3264                 tcmu_attrs[i] = passthrough_attrib_attrs[i];
3265         for (k = 0; passthrough_pr_attrib_attrs[k] != NULL; k++)
3266                 tcmu_attrs[i++] = passthrough_pr_attrib_attrs[k];
3267         for (k = 0; tcmu_attrib_attrs[k] != NULL; k++)
3268                 tcmu_attrs[i++] = tcmu_attrib_attrs[k];
3269         tcmu_ops.tb_dev_attrib_attrs = tcmu_attrs;
3270
3271         ret = transport_backend_register(&tcmu_ops);
3272         if (ret)
3273                 goto out_attrs;
3274
3275         return 0;
3276
3277 out_attrs:
3278         kfree(tcmu_attrs);
3279 out_unreg_genl:
3280         genl_unregister_family(&tcmu_genl_family);
3281 out_unreg_device:
3282         root_device_unregister(tcmu_root_device);
3283 out_free_cache:
3284         kmem_cache_destroy(tcmu_cmd_cache);
3285
3286         return ret;
3287 }
3288
3289 static void __exit tcmu_module_exit(void)
3290 {
3291         cancel_delayed_work_sync(&tcmu_unmap_work);
3292         target_backend_unregister(&tcmu_ops);
3293         kfree(tcmu_attrs);
3294         genl_unregister_family(&tcmu_genl_family);
3295         root_device_unregister(tcmu_root_device);
3296         kmem_cache_destroy(tcmu_cmd_cache);
3297 }
3298
3299 MODULE_DESCRIPTION("TCM USER subsystem plugin");
3300 MODULE_AUTHOR("Shaohua Li <shli@kernel.org>");
3301 MODULE_AUTHOR("Andy Grover <agrover@redhat.com>");
3302 MODULE_LICENSE("GPL");
3303
3304 module_init(tcmu_module_init);
3305 module_exit(tcmu_module_exit);