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 <linux/pagemap.h>
  24 #include <net/genetlink.h>
  25 #include <scsi/scsi_common.h>
  26 #include <scsi/scsi_proto.h>
  27 #include <target/target_core_base.h>
  28 #include <target/target_core_fabric.h>
  29 #include <target/target_core_backend.h>
  30
  31 #include <linux/target_core_user.h>
  32
  33 /**
  34  * DOC: Userspace I/O
  35  * Userspace I/O
  36  * -------------
  37  *
  38  * Define a shared-memory interface for LIO to pass SCSI commands and
  39  * data to userspace for processing. This is to allow backends that
  40  * are too complex for in-kernel support to be possible.
  41  *
  42  * It uses the UIO framework to do a lot of the device-creation and
  43  * introspection work for us.
  44  *
  45  * See the .h file for how the ring is laid out. Note that while the
  46  * command ring is defined, the particulars of the data area are
  47  * not. Offset values in the command entry point to other locations
  48  * internal to the mmap-ed area. There is separate space outside the
  49  * command ring for data buffers. This leaves maximum flexibility for
  50  * moving buffer allocations, or even page flipping or other
  51  * allocation techniques, without altering the command ring layout.
  52  *
  53  * SECURITY:
  54  * The user process must be assumed to be malicious. There's no way to
  55  * prevent it breaking the command ring protocol if it wants, but in
  56  * order to prevent other issues we must only ever read *data* from
  57  * the shared memory area, not offsets or sizes. This applies to
  58  * command ring entries as well as the mailbox. Extra code needed for
  59  * this may have a 'UAM' comment.
  60  */
  61
  62 #define TCMU_TIME_OUT (30 * MSEC_PER_SEC)
  63
  64 /* For mailbox plus cmd ring, the size is fixed 8MB */
  65 #define MB_CMDR_SIZE_DEF (8 * 1024 * 1024)
  66 /* Offset of cmd ring is size of mailbox */
  67 #define CMDR_OFF ((__u32)sizeof(struct tcmu_mailbox))
  68 #define CMDR_SIZE_DEF (MB_CMDR_SIZE_DEF - CMDR_OFF)
  69
  70 /*
  71  * For data area, the default block size is PAGE_SIZE and
  72  * the default total size is 256K * PAGE_SIZE.
  73  */
  74 #define DATA_PAGES_PER_BLK_DEF 1
  75 #define DATA_AREA_PAGES_DEF (256 * 1024)
  76
  77 #define TCMU_MBS_TO_PAGES(_mbs) ((size_t)_mbs << (20 - PAGE_SHIFT))
  78 #define TCMU_PAGES_TO_MBS(_pages) (_pages >> (20 - PAGE_SHIFT))
  79
  80 /*
  81  * Default number of global data blocks(512K * PAGE_SIZE)
  82  * when the unmap thread will be started.
  83  */
  84 #define TCMU_GLOBAL_MAX_PAGES_DEF (512 * 1024)
  85
  86 static u8 tcmu_kern_cmd_reply_supported;
  87 static u8 tcmu_netlink_blocked;
  88
  89 static struct device *tcmu_root_device;
  90
  91 struct tcmu_hba {
  92         u32 host_id;
  93 };
  94
  95 #define TCMU_CONFIG_LEN 256
  96
  97 static DEFINE_MUTEX(tcmu_nl_cmd_mutex);
  98 static LIST_HEAD(tcmu_nl_cmd_list);
  99
 100 struct tcmu_dev;
 101
 102 struct tcmu_nl_cmd {
 103         /* wake up thread waiting for reply */
 104         struct completion complete;
 105         struct list_head nl_list;
 106         struct tcmu_dev *udev;
 107         int cmd;
 108         int status;
 109 };
 110
 111 struct tcmu_dev {
 112         struct list_head node;
 113         struct kref kref;
 114
 115         struct se_device se_dev;
 116         struct se_dev_plug se_plug;
 117
 118         char *name;
 119         struct se_hba *hba;
 120
 121 #define TCMU_DEV_BIT_OPEN 0
 122 #define TCMU_DEV_BIT_BROKEN 1
 123 #define TCMU_DEV_BIT_BLOCKED 2
 124 #define TCMU_DEV_BIT_TMR_NOTIFY 3
 125 #define TCMU_DEV_BIT_PLUGGED 4
 126         unsigned long flags;
 127
 128         struct uio_info uio_info;
 129
 130         struct inode *inode;
 131
 132         uint64_t dev_size;
 133
 134         struct tcmu_mailbox *mb_addr;
 135         void *cmdr;
 136         u32 cmdr_size;
 137         u32 cmdr_last_cleaned;
 138         /* Offset of data area from start of mb */
 139         /* Must add data_off and mb_addr to get the address */
 140         size_t data_off;
 141         int data_area_mb;
 142         uint32_t max_blocks;
 143         size_t mmap_pages;
 144
 145         struct mutex cmdr_lock;
 146         struct list_head qfull_queue;
 147         struct list_head tmr_queue;
 148
 149         uint32_t dbi_max;
 150         uint32_t dbi_thresh;
 151         unsigned long *data_bitmap;
 152         struct xarray data_pages;
 153         uint32_t data_pages_per_blk;
 154         uint32_t data_blk_size;
 155
 156         struct xarray commands;
 157
 158         struct timer_list cmd_timer;
 159         unsigned int cmd_time_out;
 160         struct list_head inflight_queue;
 161
 162         struct timer_list qfull_timer;
 163         int qfull_time_out;
 164
 165         struct list_head timedout_entry;
 166
 167         struct tcmu_nl_cmd curr_nl_cmd;
 168
 169         char dev_config[TCMU_CONFIG_LEN];
 170
 171         int nl_reply_supported;
 172 };
 173
 174 #define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev)
 175
 176 struct tcmu_cmd {
 177         struct se_cmd *se_cmd;
 178         struct tcmu_dev *tcmu_dev;
 179         struct list_head queue_entry;
 180
 181         uint16_t cmd_id;
 182
 183         /* Can't use se_cmd when cleaning up expired cmds, because if
 184            cmd has been completed then accessing se_cmd is off limits */
 185         uint32_t dbi_cnt;
 186         uint32_t dbi_bidi_cnt;
 187         uint32_t dbi_cur;
 188         uint32_t *dbi;
 189
 190         uint32_t data_len_bidi;
 191
 192         unsigned long deadline;
 193
 194 #define TCMU_CMD_BIT_EXPIRED 0
 195 #define TCMU_CMD_BIT_KEEP_BUF 1
 196         unsigned long flags;
 197 };
 198
 199 struct tcmu_tmr {
 200         struct list_head queue_entry;
 201
 202         uint8_t tmr_type;
 203         uint32_t tmr_cmd_cnt;
 204         int16_t tmr_cmd_ids[] __counted_by(tmr_cmd_cnt);
 205 };
 206
 207 /*
 208  * To avoid dead lock the mutex lock order should always be:
 209  *
 210  * mutex_lock(&root_udev_mutex);
 211  * ...
 212  * mutex_lock(&tcmu_dev->cmdr_lock);
 213  * mutex_unlock(&tcmu_dev->cmdr_lock);
 214  * ...
 215  * mutex_unlock(&root_udev_mutex);
 216  */
 217 static DEFINE_MUTEX(root_udev_mutex);
 218 static LIST_HEAD(root_udev);
 219
 220 static DEFINE_SPINLOCK(timed_out_udevs_lock);
 221 static LIST_HEAD(timed_out_udevs);
 222
 223 static struct kmem_cache *tcmu_cmd_cache;
 224
 225 static atomic_t global_page_count = ATOMIC_INIT(0);
 226 static struct delayed_work tcmu_unmap_work;
 227 static int tcmu_global_max_pages = TCMU_GLOBAL_MAX_PAGES_DEF;
 228
 229 static int tcmu_set_global_max_data_area(const char *str,
 230                                          const struct kernel_param *kp)
 231 {
 232         int ret, max_area_mb;
 233
 234         ret = kstrtoint(str, 10, &max_area_mb);
 235         if (ret)
 236                 return -EINVAL;
 237
 238         if (max_area_mb <= 0) {
 239                 pr_err("global_max_data_area must be larger than 0.\n");
 240                 return -EINVAL;
 241         }
 242
 243         tcmu_global_max_pages = TCMU_MBS_TO_PAGES(max_area_mb);
 244         if (atomic_read(&global_page_count) > tcmu_global_max_pages)
 245                 schedule_delayed_work(&tcmu_unmap_work, 0);
 246         else
 247                 cancel_delayed_work_sync(&tcmu_unmap_work);
 248
 249         return 0;
 250 }
 251
 252 static int tcmu_get_global_max_data_area(char *buffer,
 253                                          const struct kernel_param *kp)
 254 {
 255         return sprintf(buffer, "%d\n", TCMU_PAGES_TO_MBS(tcmu_global_max_pages));
 256 }
 257
 258 static const struct kernel_param_ops tcmu_global_max_data_area_op = {
 259         .set = tcmu_set_global_max_data_area,
 260         .get = tcmu_get_global_max_data_area,
 261 };
 262
 263 module_param_cb(global_max_data_area_mb, &tcmu_global_max_data_area_op, NULL,
 264                 S_IWUSR | S_IRUGO);
 265 MODULE_PARM_DESC(global_max_data_area_mb,
 266                  "Max MBs allowed to be allocated to all the tcmu device's "
 267                  "data areas.");
 268
 269 static int tcmu_get_block_netlink(char *buffer,
 270                                   const struct kernel_param *kp)
 271 {
 272         return sprintf(buffer, "%s\n", tcmu_netlink_blocked ?
 273                        "blocked" : "unblocked");
 274 }
 275
 276 static int tcmu_set_block_netlink(const char *str,
 277                                   const struct kernel_param *kp)
 278 {
 279         int ret;
 280         u8 val;
 281
 282         ret = kstrtou8(str, 0, &val);
 283         if (ret < 0)
 284                 return ret;
 285
 286         if (val > 1) {
 287                 pr_err("Invalid block netlink value %u\n", val);
 288                 return -EINVAL;
 289         }
 290
 291         tcmu_netlink_blocked = val;
 292         return 0;
 293 }
 294
 295 static const struct kernel_param_ops tcmu_block_netlink_op = {
 296         .set = tcmu_set_block_netlink,
 297         .get = tcmu_get_block_netlink,
 298 };
 299
 300 module_param_cb(block_netlink, &tcmu_block_netlink_op, NULL, S_IWUSR | S_IRUGO);
 301 MODULE_PARM_DESC(block_netlink, "Block new netlink commands.");
 302
 303 static int tcmu_fail_netlink_cmd(struct tcmu_nl_cmd *nl_cmd)
 304 {
 305         struct tcmu_dev *udev = nl_cmd->udev;
 306
 307         if (!tcmu_netlink_blocked) {
 308                 pr_err("Could not reset device's netlink interface. Netlink is not blocked.\n");
 309                 return -EBUSY;
 310         }
 311
 312         if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
 313                 pr_debug("Aborting nl cmd %d on %s\n", nl_cmd->cmd, udev->name);
 314                 nl_cmd->status = -EINTR;
 315                 list_del(&nl_cmd->nl_list);
 316                 complete(&nl_cmd->complete);
 317         }
 318         return 0;
 319 }
 320
 321 static int tcmu_set_reset_netlink(const char *str,
 322                                   const struct kernel_param *kp)
 323 {
 324         struct tcmu_nl_cmd *nl_cmd, *tmp_cmd;
 325         int ret;
 326         u8 val;
 327
 328         ret = kstrtou8(str, 0, &val);
 329         if (ret < 0)
 330                 return ret;
 331
 332         if (val != 1) {
 333                 pr_err("Invalid reset netlink value %u\n", val);
 334                 return -EINVAL;
 335         }
 336
 337         mutex_lock(&tcmu_nl_cmd_mutex);
 338         list_for_each_entry_safe(nl_cmd, tmp_cmd, &tcmu_nl_cmd_list, nl_list) {
 339                 ret = tcmu_fail_netlink_cmd(nl_cmd);
 340                 if (ret)
 341                         break;
 342         }
 343         mutex_unlock(&tcmu_nl_cmd_mutex);
 344
 345         return ret;
 346 }
 347
 348 static const struct kernel_param_ops tcmu_reset_netlink_op = {
 349         .set = tcmu_set_reset_netlink,
 350 };
 351
 352 module_param_cb(reset_netlink, &tcmu_reset_netlink_op, NULL, S_IWUSR);
 353 MODULE_PARM_DESC(reset_netlink, "Reset netlink commands.");
 354
 355 /* multicast group */
 356 enum tcmu_multicast_groups {
 357         TCMU_MCGRP_CONFIG,
 358 };
 359
 360 static const struct genl_multicast_group tcmu_mcgrps[] = {
 361         [TCMU_MCGRP_CONFIG] = { .name = "config", },
 362 };
 363
 364 static struct nla_policy tcmu_attr_policy[TCMU_ATTR_MAX+1] = {
 365         [TCMU_ATTR_DEVICE]      = { .type = NLA_STRING },
 366         [TCMU_ATTR_MINOR]       = { .type = NLA_U32 },
 367         [TCMU_ATTR_CMD_STATUS]  = { .type = NLA_S32 },
 368         [TCMU_ATTR_DEVICE_ID]   = { .type = NLA_U32 },
 369         [TCMU_ATTR_SUPP_KERN_CMD_REPLY] = { .type = NLA_U8 },
 370 };
 371
 372 static int tcmu_genl_cmd_done(struct genl_info *info, int completed_cmd)
 373 {
 374         struct tcmu_dev *udev = NULL;
 375         struct tcmu_nl_cmd *nl_cmd;
 376         int dev_id, rc, ret = 0;
 377
 378         if (!info->attrs[TCMU_ATTR_CMD_STATUS] ||
 379             !info->attrs[TCMU_ATTR_DEVICE_ID]) {
 380                 printk(KERN_ERR "TCMU_ATTR_CMD_STATUS or TCMU_ATTR_DEVICE_ID not set, doing nothing\n");
 381                 return -EINVAL;
 382         }
 383
 384         dev_id = nla_get_u32(info->attrs[TCMU_ATTR_DEVICE_ID]);
 385         rc = nla_get_s32(info->attrs[TCMU_ATTR_CMD_STATUS]);
 386
 387         mutex_lock(&tcmu_nl_cmd_mutex);
 388         list_for_each_entry(nl_cmd, &tcmu_nl_cmd_list, nl_list) {
 389                 if (nl_cmd->udev->se_dev.dev_index == dev_id) {
 390                         udev = nl_cmd->udev;
 391                         break;
 392                 }
 393         }
 394
 395         if (!udev) {
 396                 pr_err("tcmu nl cmd %u/%d completion could not find device with dev id %u.\n",
 397                        completed_cmd, rc, dev_id);
 398                 ret = -ENODEV;
 399                 goto unlock;
 400         }
 401         list_del(&nl_cmd->nl_list);
 402
 403         pr_debug("%s genl cmd done got id %d curr %d done %d rc %d stat %d\n",
 404                  udev->name, dev_id, nl_cmd->cmd, completed_cmd, rc,
 405                  nl_cmd->status);
 406
 407         if (nl_cmd->cmd != completed_cmd) {
 408                 pr_err("Mismatched commands on %s (Expecting reply for %d. Current %d).\n",
 409                        udev->name, completed_cmd, nl_cmd->cmd);
 410                 ret = -EINVAL;
 411                 goto unlock;
 412         }
 413
 414         nl_cmd->status = rc;
 415         complete(&nl_cmd->complete);
 416 unlock:
 417         mutex_unlock(&tcmu_nl_cmd_mutex);
 418         return ret;
 419 }
 420
 421 static int tcmu_genl_rm_dev_done(struct sk_buff *skb, struct genl_info *info)
 422 {
 423         return tcmu_genl_cmd_done(info, TCMU_CMD_REMOVED_DEVICE);
 424 }
 425
 426 static int tcmu_genl_add_dev_done(struct sk_buff *skb, struct genl_info *info)
 427 {
 428         return tcmu_genl_cmd_done(info, TCMU_CMD_ADDED_DEVICE);
 429 }
 430
 431 static int tcmu_genl_reconfig_dev_done(struct sk_buff *skb,
 432                                        struct genl_info *info)
 433 {
 434         return tcmu_genl_cmd_done(info, TCMU_CMD_RECONFIG_DEVICE);
 435 }
 436
 437 static int tcmu_genl_set_features(struct sk_buff *skb, struct genl_info *info)
 438 {
 439         if (info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]) {
 440                 tcmu_kern_cmd_reply_supported  =
 441                         nla_get_u8(info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]);
 442                 printk(KERN_INFO "tcmu daemon: command reply support %u.\n",
 443                        tcmu_kern_cmd_reply_supported);
 444         }
 445
 446         return 0;
 447 }
 448
 449 static const struct genl_small_ops tcmu_genl_ops[] = {
 450         {
 451                 .cmd    = TCMU_CMD_SET_FEATURES,
 452                 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 453                 .flags  = GENL_ADMIN_PERM,
 454                 .doit   = tcmu_genl_set_features,
 455         },
 456         {
 457                 .cmd    = TCMU_CMD_ADDED_DEVICE_DONE,
 458                 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 459                 .flags  = GENL_ADMIN_PERM,
 460                 .doit   = tcmu_genl_add_dev_done,
 461         },
 462         {
 463                 .cmd    = TCMU_CMD_REMOVED_DEVICE_DONE,
 464                 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 465                 .flags  = GENL_ADMIN_PERM,
 466                 .doit   = tcmu_genl_rm_dev_done,
 467         },
 468         {
 469                 .cmd    = TCMU_CMD_RECONFIG_DEVICE_DONE,
 470                 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 471                 .flags  = GENL_ADMIN_PERM,
 472                 .doit   = tcmu_genl_reconfig_dev_done,
 473         },
 474 };
 475
 476 /* Our generic netlink family */
 477 static struct genl_family tcmu_genl_family __ro_after_init = {
 478         .module = THIS_MODULE,
 479         .hdrsize = 0,
 480         .name = "TCM-USER",
 481         .version = 2,
 482         .maxattr = TCMU_ATTR_MAX,
 483         .policy = tcmu_attr_policy,
 484         .mcgrps = tcmu_mcgrps,
 485         .n_mcgrps = ARRAY_SIZE(tcmu_mcgrps),
 486         .netnsok = true,
 487         .small_ops = tcmu_genl_ops,
 488         .n_small_ops = ARRAY_SIZE(tcmu_genl_ops),
 489         .resv_start_op = TCMU_CMD_SET_FEATURES + 1,
 490 };
 491
 492 #define tcmu_cmd_set_dbi_cur(cmd, index) ((cmd)->dbi_cur = (index))
 493 #define tcmu_cmd_reset_dbi_cur(cmd) tcmu_cmd_set_dbi_cur(cmd, 0)
 494 #define tcmu_cmd_set_dbi(cmd, index) ((cmd)->dbi[(cmd)->dbi_cur++] = (index))
 495 #define tcmu_cmd_get_dbi(cmd) ((cmd)->dbi[(cmd)->dbi_cur++])
 496
 497 static void tcmu_cmd_free_data(struct tcmu_cmd *tcmu_cmd, uint32_t len)
 498 {
 499         struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
 500         uint32_t i;
 501
 502         for (i = 0; i < len; i++)
 503                 clear_bit(tcmu_cmd->dbi[i], udev->data_bitmap);
 504 }
 505
 506 static inline int tcmu_get_empty_block(struct tcmu_dev *udev,
 507                                        struct tcmu_cmd *tcmu_cmd,
 508                                        int prev_dbi, int length, int *iov_cnt)
 509 {
 510         XA_STATE(xas, &udev->data_pages, 0);
 511         struct page *page;
 512         int i, cnt, dbi, dpi;
 513         int page_cnt = DIV_ROUND_UP(length, PAGE_SIZE);
 514
 515         dbi = find_first_zero_bit(udev->data_bitmap, udev->dbi_thresh);
 516         if (dbi == udev->dbi_thresh)
 517                 return -1;
 518
 519         dpi = dbi * udev->data_pages_per_blk;
 520         /* Count the number of already allocated pages */
 521         xas_set(&xas, dpi);
 522         rcu_read_lock();
 523         for (cnt = 0; xas_next(&xas) && cnt < page_cnt;)
 524                 cnt++;
 525         rcu_read_unlock();
 526
 527         for (i = cnt; i < page_cnt; i++) {
 528                 /* try to get new zeroed page from the mm */
 529                 page = alloc_page(GFP_NOIO | __GFP_ZERO);
 530                 if (!page)
 531                         break;
 532
 533                 if (xa_store(&udev->data_pages, dpi + i, page, GFP_NOIO)) {
 534                         __free_page(page);
 535                         break;
 536                 }
 537         }
 538         if (atomic_add_return(i - cnt, &global_page_count) >
 539                               tcmu_global_max_pages)
 540                 schedule_delayed_work(&tcmu_unmap_work, 0);
 541
 542         if (i && dbi > udev->dbi_max)
 543                 udev->dbi_max = dbi;
 544
 545         set_bit(dbi, udev->data_bitmap);
 546         tcmu_cmd_set_dbi(tcmu_cmd, dbi);
 547
 548         if (dbi != prev_dbi + 1)
 549                 *iov_cnt += 1;
 550
 551         return i == page_cnt ? dbi : -1;
 552 }
 553
 554 static int tcmu_get_empty_blocks(struct tcmu_dev *udev,
 555                                  struct tcmu_cmd *tcmu_cmd, int length)
 556 {
 557         /* start value of dbi + 1 must not be a valid dbi */
 558         int dbi = -2;
 559         int blk_data_len, iov_cnt = 0;
 560         uint32_t blk_size = udev->data_blk_size;
 561
 562         for (; length > 0; length -= blk_size) {
 563                 blk_data_len = min_t(uint32_t, length, blk_size);
 564                 dbi = tcmu_get_empty_block(udev, tcmu_cmd, dbi, blk_data_len,
 565                                            &iov_cnt);
 566                 if (dbi < 0)
 567                         return -1;
 568         }
 569         return iov_cnt;
 570 }
 571
 572 static inline void tcmu_free_cmd(struct tcmu_cmd *tcmu_cmd)
 573 {
 574         kfree(tcmu_cmd->dbi);
 575         kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
 576 }
 577
 578 static inline void tcmu_cmd_set_block_cnts(struct tcmu_cmd *cmd)
 579 {
 580         int i, len;
 581         struct se_cmd *se_cmd = cmd->se_cmd;
 582         uint32_t blk_size = cmd->tcmu_dev->data_blk_size;
 583
 584         cmd->dbi_cnt = DIV_ROUND_UP(se_cmd->data_length, blk_size);
 585
 586         if (se_cmd->se_cmd_flags & SCF_BIDI) {
 587                 BUG_ON(!(se_cmd->t_bidi_data_sg && se_cmd->t_bidi_data_nents));
 588                 for (i = 0, len = 0; i < se_cmd->t_bidi_data_nents; i++)
 589                         len += se_cmd->t_bidi_data_sg[i].length;
 590                 cmd->dbi_bidi_cnt = DIV_ROUND_UP(len, blk_size);
 591                 cmd->dbi_cnt += cmd->dbi_bidi_cnt;
 592                 cmd->data_len_bidi = len;
 593         }
 594 }
 595
 596 static int new_block_to_iov(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
 597                             struct iovec **iov, int prev_dbi, int len)
 598 {
 599         /* Get the next dbi */
 600         int dbi = tcmu_cmd_get_dbi(cmd);
 601
 602         /* Do not add more than udev->data_blk_size to iov */
 603         len = min_t(int,  len, udev->data_blk_size);
 604
 605         /*
 606          * The following code will gather and map the blocks to the same iovec
 607          * when the blocks are all next to each other.
 608          */
 609         if (dbi != prev_dbi + 1) {
 610                 /* dbi is not next to previous dbi, so start new iov */
 611                 if (prev_dbi >= 0)
 612                         (*iov)++;
 613                 /* write offset relative to mb_addr */
 614                 (*iov)->iov_base = (void __user *)
 615                                    (udev->data_off + dbi * udev->data_blk_size);
 616         }
 617         (*iov)->iov_len += len;
 618
 619         return dbi;
 620 }
 621
 622 static void tcmu_setup_iovs(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
 623                             struct iovec **iov, int data_length)
 624 {
 625         /* start value of dbi + 1 must not be a valid dbi */
 626         int dbi = -2;
 627
 628         /* We prepare the IOVs for DMA_FROM_DEVICE transfer direction */
 629         for (; data_length > 0; data_length -= udev->data_blk_size)
 630                 dbi = new_block_to_iov(udev, cmd, iov, dbi, data_length);
 631 }
 632
 633 static struct tcmu_cmd *tcmu_alloc_cmd(struct se_cmd *se_cmd)
 634 {
 635         struct se_device *se_dev = se_cmd->se_dev;
 636         struct tcmu_dev *udev = TCMU_DEV(se_dev);
 637         struct tcmu_cmd *tcmu_cmd;
 638
 639         tcmu_cmd = kmem_cache_zalloc(tcmu_cmd_cache, GFP_NOIO);
 640         if (!tcmu_cmd)
 641                 return NULL;
 642
 643         INIT_LIST_HEAD(&tcmu_cmd->queue_entry);
 644         tcmu_cmd->se_cmd = se_cmd;
 645         tcmu_cmd->tcmu_dev = udev;
 646
 647         tcmu_cmd_set_block_cnts(tcmu_cmd);
 648         tcmu_cmd->dbi = kcalloc(tcmu_cmd->dbi_cnt, sizeof(uint32_t),
 649                                 GFP_NOIO);
 650         if (!tcmu_cmd->dbi) {
 651                 kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
 652                 return NULL;
 653         }
 654
 655         return tcmu_cmd;
 656 }
 657
 658 static inline void tcmu_flush_dcache_range(void *vaddr, size_t size)
 659 {
 660         unsigned long offset = offset_in_page(vaddr);
 661         void *start = vaddr - offset;
 662
 663         size = round_up(size+offset, PAGE_SIZE);
 664
 665         while (size) {
 666                 flush_dcache_page(vmalloc_to_page(start));
 667                 start += PAGE_SIZE;
 668                 size -= PAGE_SIZE;
 669         }
 670 }
 671
 672 /*
 673  * Some ring helper functions. We don't assume size is a power of 2 so
 674  * we can't use circ_buf.h.
 675  */
 676 static inline size_t spc_used(size_t head, size_t tail, size_t size)
 677 {
 678         int diff = head - tail;
 679
 680         if (diff >= 0)
 681                 return diff;
 682         else
 683                 return size + diff;
 684 }
 685
 686 static inline size_t spc_free(size_t head, size_t tail, size_t size)
 687 {
 688         /* Keep 1 byte unused or we can't tell full from empty */
 689         return (size - spc_used(head, tail, size) - 1);
 690 }
 691
 692 static inline size_t head_to_end(size_t head, size_t size)
 693 {
 694         return size - head;
 695 }
 696
 697 #define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size)
 698
 699 #define TCMU_SG_TO_DATA_AREA 1
 700 #define TCMU_DATA_AREA_TO_SG 2
 701
 702 static inline void tcmu_copy_data(struct tcmu_dev *udev,
 703                                   struct tcmu_cmd *tcmu_cmd, uint32_t direction,
 704                                   struct scatterlist *sg, unsigned int sg_nents,
 705                                   struct iovec **iov, size_t data_len)
 706 {
 707         /* start value of dbi + 1 must not be a valid dbi */
 708         int dbi = -2;
 709         size_t page_remaining, cp_len;
 710         int page_cnt, page_inx, dpi;
 711         struct sg_mapping_iter sg_iter;
 712         unsigned int sg_flags;
 713         struct page *page;
 714         void *data_page_start, *data_addr;
 715
 716         if (direction == TCMU_SG_TO_DATA_AREA)
 717                 sg_flags = SG_MITER_ATOMIC | SG_MITER_FROM_SG;
 718         else
 719                 sg_flags = SG_MITER_ATOMIC | SG_MITER_TO_SG;
 720         sg_miter_start(&sg_iter, sg, sg_nents, sg_flags);
 721
 722         while (data_len) {
 723                 if (direction == TCMU_SG_TO_DATA_AREA)
 724                         dbi = new_block_to_iov(udev, tcmu_cmd, iov, dbi,
 725                                                data_len);
 726                 else
 727                         dbi = tcmu_cmd_get_dbi(tcmu_cmd);
 728
 729                 page_cnt = DIV_ROUND_UP(data_len, PAGE_SIZE);
 730                 if (page_cnt > udev->data_pages_per_blk)
 731                         page_cnt = udev->data_pages_per_blk;
 732
 733                 dpi = dbi * udev->data_pages_per_blk;
 734                 for (page_inx = 0; page_inx < page_cnt && data_len;
 735                      page_inx++, dpi++) {
 736                         page = xa_load(&udev->data_pages, dpi);
 737
 738                         if (direction == TCMU_DATA_AREA_TO_SG)
 739                                 flush_dcache_page(page);
 740                         data_page_start = kmap_atomic(page);
 741                         page_remaining = PAGE_SIZE;
 742
 743                         while (page_remaining && data_len) {
 744                                 if (!sg_miter_next(&sg_iter)) {
 745                                         /* set length to 0 to abort outer loop */
 746                                         data_len = 0;
 747                                         pr_debug("%s: aborting data copy due to exhausted sg_list\n",
 748                                                  __func__);
 749                                         break;
 750                                 }
 751                                 cp_len = min3(sg_iter.length, page_remaining,
 752                                               data_len);
 753
 754                                 data_addr = data_page_start +
 755                                             PAGE_SIZE - page_remaining;
 756                                 if (direction == TCMU_SG_TO_DATA_AREA)
 757                                         memcpy(data_addr, sg_iter.addr, cp_len);
 758                                 else
 759                                         memcpy(sg_iter.addr, data_addr, cp_len);
 760
 761                                 data_len -= cp_len;
 762                                 page_remaining -= cp_len;
 763                                 sg_iter.consumed = cp_len;
 764                         }
 765                         sg_miter_stop(&sg_iter);
 766
 767                         kunmap_atomic(data_page_start);
 768                         if (direction == TCMU_SG_TO_DATA_AREA)
 769                                 flush_dcache_page(page);
 770                 }
 771         }
 772 }
 773
 774 static void scatter_data_area(struct tcmu_dev *udev, struct tcmu_cmd *tcmu_cmd,
 775                               struct iovec **iov)
 776 {
 777         struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
 778
 779         tcmu_copy_data(udev, tcmu_cmd, TCMU_SG_TO_DATA_AREA, se_cmd->t_data_sg,
 780                        se_cmd->t_data_nents, iov, se_cmd->data_length);
 781 }
 782
 783 static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *tcmu_cmd,
 784                              bool bidi, uint32_t read_len)
 785 {
 786         struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
 787         struct scatterlist *data_sg;
 788         unsigned int data_nents;
 789
 790         if (!bidi) {
 791                 data_sg = se_cmd->t_data_sg;
 792                 data_nents = se_cmd->t_data_nents;
 793         } else {
 794                 /*
 795                  * For bidi case, the first count blocks are for Data-Out
 796                  * buffer blocks, and before gathering the Data-In buffer
 797                  * the Data-Out buffer blocks should be skipped.
 798                  */
 799                 tcmu_cmd_set_dbi_cur(tcmu_cmd,
 800                                      tcmu_cmd->dbi_cnt - tcmu_cmd->dbi_bidi_cnt);
 801
 802                 data_sg = se_cmd->t_bidi_data_sg;
 803                 data_nents = se_cmd->t_bidi_data_nents;
 804         }
 805
 806         tcmu_copy_data(udev, tcmu_cmd, TCMU_DATA_AREA_TO_SG, data_sg,
 807                        data_nents, NULL, read_len);
 808 }
 809
 810 static inline size_t spc_bitmap_free(unsigned long *bitmap, uint32_t thresh)
 811 {
 812         return thresh - bitmap_weight(bitmap, thresh);
 813 }
 814
 815 /*
 816  * We can't queue a command until we have space available on the cmd ring.
 817  *
 818  * Called with ring lock held.
 819  */
 820 static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size)
 821 {
 822         struct tcmu_mailbox *mb = udev->mb_addr;
 823         size_t space, cmd_needed;
 824         u32 cmd_head;
 825
 826         tcmu_flush_dcache_range(mb, sizeof(*mb));
 827
 828         cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
 829
 830         /*
 831          * If cmd end-of-ring space is too small then we need space for a NOP plus
 832          * original cmd - cmds are internally contiguous.
 833          */
 834         if (head_to_end(cmd_head, udev->cmdr_size) >= cmd_size)
 835                 cmd_needed = cmd_size;
 836         else
 837                 cmd_needed = cmd_size + head_to_end(cmd_head, udev->cmdr_size);
 838
 839         space = spc_free(cmd_head, udev->cmdr_last_cleaned, udev->cmdr_size);
 840         if (space < cmd_needed) {
 841                 pr_debug("no cmd space: %u %u %u\n", cmd_head,
 842                        udev->cmdr_last_cleaned, udev->cmdr_size);
 843                 return false;
 844         }
 845         return true;
 846 }
 847
 848 /*
 849  * We have to allocate data buffers before we can queue a command.
 850  * Returns -1 on error (not enough space) or number of needed iovs on success
 851  *
 852  * Called with ring lock held.
 853  */
 854 static int tcmu_alloc_data_space(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
 855                                   int *iov_bidi_cnt)
 856 {
 857         int space, iov_cnt = 0, ret = 0;
 858
 859         if (!cmd->dbi_cnt)
 860                 goto wr_iov_cnts;
 861
 862         /* try to check and get the data blocks as needed */
 863         space = spc_bitmap_free(udev->data_bitmap, udev->dbi_thresh);
 864         if (space < cmd->dbi_cnt) {
 865                 unsigned long blocks_left =
 866                                 (udev->max_blocks - udev->dbi_thresh) + space;
 867
 868                 if (blocks_left < cmd->dbi_cnt) {
 869                         pr_debug("no data space: only %lu available, but ask for %u\n",
 870                                         blocks_left * udev->data_blk_size,
 871                                         cmd->dbi_cnt * udev->data_blk_size);
 872                         return -1;
 873                 }
 874
 875                 udev->dbi_thresh += cmd->dbi_cnt;
 876                 if (udev->dbi_thresh > udev->max_blocks)
 877                         udev->dbi_thresh = udev->max_blocks;
 878         }
 879
 880         iov_cnt = tcmu_get_empty_blocks(udev, cmd, cmd->se_cmd->data_length);
 881         if (iov_cnt < 0)
 882                 return -1;
 883
 884         if (cmd->dbi_bidi_cnt) {
 885                 ret = tcmu_get_empty_blocks(udev, cmd, cmd->data_len_bidi);
 886                 if (ret < 0)
 887                         return -1;
 888         }
 889 wr_iov_cnts:
 890         *iov_bidi_cnt = ret;
 891         return iov_cnt + ret;
 892 }
 893
 894 static inline size_t tcmu_cmd_get_base_cmd_size(size_t iov_cnt)
 895 {
 896         return max(offsetof(struct tcmu_cmd_entry, req.iov[iov_cnt]),
 897                         sizeof(struct tcmu_cmd_entry));
 898 }
 899
 900 static inline size_t tcmu_cmd_get_cmd_size(struct tcmu_cmd *tcmu_cmd,
 901                                            size_t base_command_size)
 902 {
 903         struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
 904         size_t command_size;
 905
 906         command_size = base_command_size +
 907                 round_up(scsi_command_size(se_cmd->t_task_cdb),
 908                                 TCMU_OP_ALIGN_SIZE);
 909
 910         WARN_ON(command_size & (TCMU_OP_ALIGN_SIZE-1));
 911
 912         return command_size;
 913 }
 914
 915 static void tcmu_setup_cmd_timer(struct tcmu_cmd *tcmu_cmd, unsigned int tmo,
 916                                  struct timer_list *timer)
 917 {
 918         if (!tmo)
 919                 return;
 920
 921         tcmu_cmd->deadline = round_jiffies_up(jiffies + msecs_to_jiffies(tmo));
 922         if (!timer_pending(timer))
 923                 mod_timer(timer, tcmu_cmd->deadline);
 924
 925         pr_debug("Timeout set up for cmd %p, dev = %s, tmo = %lu\n", tcmu_cmd,
 926                  tcmu_cmd->tcmu_dev->name, tmo / MSEC_PER_SEC);
 927 }
 928
 929 static int add_to_qfull_queue(struct tcmu_cmd *tcmu_cmd)
 930 {
 931         struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
 932         unsigned int tmo;
 933
 934         /*
 935          * For backwards compat if qfull_time_out is not set use
 936          * cmd_time_out and if that's not set use the default time out.
 937          */
 938         if (!udev->qfull_time_out)
 939                 return -ETIMEDOUT;
 940         else if (udev->qfull_time_out > 0)
 941                 tmo = udev->qfull_time_out;
 942         else if (udev->cmd_time_out)
 943                 tmo = udev->cmd_time_out;
 944         else
 945                 tmo = TCMU_TIME_OUT;
 946
 947         tcmu_setup_cmd_timer(tcmu_cmd, tmo, &udev->qfull_timer);
 948
 949         list_add_tail(&tcmu_cmd->queue_entry, &udev->qfull_queue);
 950         pr_debug("adding cmd %p on dev %s to ring space wait queue\n",
 951                  tcmu_cmd, udev->name);
 952         return 0;
 953 }
 954
 955 static uint32_t ring_insert_padding(struct tcmu_dev *udev, size_t cmd_size)
 956 {
 957         struct tcmu_cmd_entry_hdr *hdr;
 958         struct tcmu_mailbox *mb = udev->mb_addr;
 959         uint32_t cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
 960
 961         /* Insert a PAD if end-of-ring space is too small */
 962         if (head_to_end(cmd_head, udev->cmdr_size) < cmd_size) {
 963                 size_t pad_size = head_to_end(cmd_head, udev->cmdr_size);
 964
 965                 hdr = udev->cmdr + cmd_head;
 966                 tcmu_hdr_set_op(&hdr->len_op, TCMU_OP_PAD);
 967                 tcmu_hdr_set_len(&hdr->len_op, pad_size);
 968                 hdr->cmd_id = 0; /* not used for PAD */
 969                 hdr->kflags = 0;
 970                 hdr->uflags = 0;
 971                 tcmu_flush_dcache_range(hdr, sizeof(*hdr));
 972
 973                 UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size);
 974                 tcmu_flush_dcache_range(mb, sizeof(*mb));
 975
 976                 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
 977                 WARN_ON(cmd_head != 0);
 978         }
 979
 980         return cmd_head;
 981 }
 982
 983 static void tcmu_unplug_device(struct se_dev_plug *se_plug)
 984 {
 985         struct se_device *se_dev = se_plug->se_dev;
 986         struct tcmu_dev *udev = TCMU_DEV(se_dev);
 987
 988         clear_bit(TCMU_DEV_BIT_PLUGGED, &udev->flags);
 989         uio_event_notify(&udev->uio_info);
 990 }
 991
 992 static struct se_dev_plug *tcmu_plug_device(struct se_device *se_dev)
 993 {
 994         struct tcmu_dev *udev = TCMU_DEV(se_dev);
 995
 996         if (!test_and_set_bit(TCMU_DEV_BIT_PLUGGED, &udev->flags))
 997                 return &udev->se_plug;
 998
 999         return NULL;
1000 }
1001
1002 /**
1003  * queue_cmd_ring - queue cmd to ring or internally
1004  * @tcmu_cmd: cmd to queue
1005  * @scsi_err: TCM error code if failure (-1) returned.
1006  *
1007  * Returns:
1008  * -1 we cannot queue internally or to the ring.
1009  *  0 success
1010  *  1 internally queued to wait for ring memory to free.
1011  */
1012 static int queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, sense_reason_t *scsi_err)
1013 {
1014         struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
1015         struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
1016         size_t base_command_size, command_size;
1017         struct tcmu_mailbox *mb = udev->mb_addr;
1018         struct tcmu_cmd_entry *entry;
1019         struct iovec *iov;
1020         int iov_cnt, iov_bidi_cnt;
1021         uint32_t cmd_id, cmd_head;
1022         uint64_t cdb_off;
1023         uint32_t blk_size = udev->data_blk_size;
1024         /* size of data buffer needed */
1025         size_t data_length = (size_t)tcmu_cmd->dbi_cnt * blk_size;
1026
1027         *scsi_err = TCM_NO_SENSE;
1028
1029         if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags)) {
1030                 *scsi_err = TCM_LUN_BUSY;
1031                 return -1;
1032         }
1033
1034         if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
1035                 *scsi_err = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1036                 return -1;
1037         }
1038
1039         if (!list_empty(&udev->qfull_queue))
1040                 goto queue;
1041
1042         if (data_length > (size_t)udev->max_blocks * blk_size) {
1043                 pr_warn("TCMU: Request of size %zu is too big for %zu data area\n",
1044                         data_length, (size_t)udev->max_blocks * blk_size);
1045                 *scsi_err = TCM_INVALID_CDB_FIELD;
1046                 return -1;
1047         }
1048
1049         iov_cnt = tcmu_alloc_data_space(udev, tcmu_cmd, &iov_bidi_cnt);
1050         if (iov_cnt < 0)
1051                 goto free_and_queue;
1052
1053         /*
1054          * Must be a certain minimum size for response sense info, but
1055          * also may be larger if the iov array is large.
1056          */
1057         base_command_size = tcmu_cmd_get_base_cmd_size(iov_cnt);
1058         command_size = tcmu_cmd_get_cmd_size(tcmu_cmd, base_command_size);
1059
1060         if (command_size > (udev->cmdr_size / 2)) {
1061                 pr_warn("TCMU: Request of size %zu is too big for %u cmd ring\n",
1062                         command_size, udev->cmdr_size);
1063                 tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cur);
1064                 *scsi_err = TCM_INVALID_CDB_FIELD;
1065                 return -1;
1066         }
1067
1068         if (!is_ring_space_avail(udev, command_size))
1069                 /*
1070                  * Don't leave commands partially setup because the unmap
1071                  * thread might need the blocks to make forward progress.
1072                  */
1073                 goto free_and_queue;
1074
1075         if (xa_alloc(&udev->commands, &cmd_id, tcmu_cmd, XA_LIMIT(1, 0xffff),
1076                      GFP_NOWAIT) < 0) {
1077                 pr_err("tcmu: Could not allocate cmd id.\n");
1078
1079                 tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cnt);
1080                 *scsi_err = TCM_OUT_OF_RESOURCES;
1081                 return -1;
1082         }
1083         tcmu_cmd->cmd_id = cmd_id;
1084
1085         pr_debug("allocated cmd id %u for cmd %p dev %s\n", tcmu_cmd->cmd_id,
1086                  tcmu_cmd, udev->name);
1087
1088         cmd_head = ring_insert_padding(udev, command_size);
1089
1090         entry = udev->cmdr + cmd_head;
1091         memset(entry, 0, command_size);
1092         tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_CMD);
1093
1094         /* prepare iov list and copy data to data area if necessary */
1095         tcmu_cmd_reset_dbi_cur(tcmu_cmd);
1096         iov = &entry->req.iov[0];
1097
1098         if (se_cmd->data_direction == DMA_TO_DEVICE ||
1099             se_cmd->se_cmd_flags & SCF_BIDI)
1100                 scatter_data_area(udev, tcmu_cmd, &iov);
1101         else
1102                 tcmu_setup_iovs(udev, tcmu_cmd, &iov, se_cmd->data_length);
1103
1104         entry->req.iov_cnt = iov_cnt - iov_bidi_cnt;
1105
1106         /* Handle BIDI commands */
1107         if (se_cmd->se_cmd_flags & SCF_BIDI) {
1108                 iov++;
1109                 tcmu_setup_iovs(udev, tcmu_cmd, &iov, tcmu_cmd->data_len_bidi);
1110                 entry->req.iov_bidi_cnt = iov_bidi_cnt;
1111         }
1112
1113         tcmu_setup_cmd_timer(tcmu_cmd, udev->cmd_time_out, &udev->cmd_timer);
1114
1115         entry->hdr.cmd_id = tcmu_cmd->cmd_id;
1116
1117         tcmu_hdr_set_len(&entry->hdr.len_op, command_size);
1118
1119         /* All offsets relative to mb_addr, not start of entry! */
1120         cdb_off = CMDR_OFF + cmd_head + base_command_size;
1121         memcpy((void *) mb + cdb_off, se_cmd->t_task_cdb, scsi_command_size(se_cmd->t_task_cdb));
1122         entry->req.cdb_off = cdb_off;
1123         tcmu_flush_dcache_range(entry, command_size);
1124
1125         UPDATE_HEAD(mb->cmd_head, command_size, udev->cmdr_size);
1126         tcmu_flush_dcache_range(mb, sizeof(*mb));
1127
1128         list_add_tail(&tcmu_cmd->queue_entry, &udev->inflight_queue);
1129
1130         if (!test_bit(TCMU_DEV_BIT_PLUGGED, &udev->flags))
1131                 uio_event_notify(&udev->uio_info);
1132
1133         return 0;
1134
1135 free_and_queue:
1136         tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cur);
1137         tcmu_cmd_reset_dbi_cur(tcmu_cmd);
1138
1139 queue:
1140         if (add_to_qfull_queue(tcmu_cmd)) {
1141                 *scsi_err = TCM_OUT_OF_RESOURCES;
1142                 return -1;
1143         }
1144
1145         return 1;
1146 }
1147
1148 /**
1149  * queue_tmr_ring - queue tmr info to ring or internally
1150  * @udev: related tcmu_dev
1151  * @tmr: tcmu_tmr containing tmr info to queue
1152  *
1153  * Returns:
1154  *  0 success
1155  *  1 internally queued to wait for ring memory to free.
1156  */
1157 static int
1158 queue_tmr_ring(struct tcmu_dev *udev, struct tcmu_tmr *tmr)
1159 {
1160         struct tcmu_tmr_entry *entry;
1161         int cmd_size;
1162         int id_list_sz;
1163         struct tcmu_mailbox *mb = udev->mb_addr;
1164         uint32_t cmd_head;
1165
1166         if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags))
1167                 goto out_free;
1168
1169         id_list_sz = sizeof(tmr->tmr_cmd_ids[0]) * tmr->tmr_cmd_cnt;
1170         cmd_size = round_up(sizeof(*entry) + id_list_sz, TCMU_OP_ALIGN_SIZE);
1171
1172         if (!list_empty(&udev->tmr_queue) ||
1173             !is_ring_space_avail(udev, cmd_size)) {
1174                 list_add_tail(&tmr->queue_entry, &udev->tmr_queue);
1175                 pr_debug("adding tmr %p on dev %s to TMR ring space wait queue\n",
1176                          tmr, udev->name);
1177                 return 1;
1178         }
1179
1180         cmd_head = ring_insert_padding(udev, cmd_size);
1181
1182         entry = udev->cmdr + cmd_head;
1183         memset(entry, 0, cmd_size);
1184         tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_TMR);
1185         tcmu_hdr_set_len(&entry->hdr.len_op, cmd_size);
1186         entry->tmr_type = tmr->tmr_type;
1187         entry->cmd_cnt = tmr->tmr_cmd_cnt;
1188         memcpy(&entry->cmd_ids[0], &tmr->tmr_cmd_ids[0], id_list_sz);
1189         tcmu_flush_dcache_range(entry, cmd_size);
1190
1191         UPDATE_HEAD(mb->cmd_head, cmd_size, udev->cmdr_size);
1192         tcmu_flush_dcache_range(mb, sizeof(*mb));
1193
1194         uio_event_notify(&udev->uio_info);
1195
1196 out_free:
1197         kfree(tmr);
1198
1199         return 0;
1200 }
1201
1202 static sense_reason_t
1203 tcmu_queue_cmd(struct se_cmd *se_cmd)
1204 {
1205         struct se_device *se_dev = se_cmd->se_dev;
1206         struct tcmu_dev *udev = TCMU_DEV(se_dev);
1207         struct tcmu_cmd *tcmu_cmd;
1208         sense_reason_t scsi_ret = TCM_CHECK_CONDITION_ABORT_CMD;
1209         int ret = -1;
1210
1211         tcmu_cmd = tcmu_alloc_cmd(se_cmd);
1212         if (!tcmu_cmd)
1213                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1214
1215         mutex_lock(&udev->cmdr_lock);
1216         if (!(se_cmd->transport_state & CMD_T_ABORTED))
1217                 ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
1218         if (ret < 0)
1219                 tcmu_free_cmd(tcmu_cmd);
1220         else
1221                 se_cmd->priv = tcmu_cmd;
1222         mutex_unlock(&udev->cmdr_lock);
1223         return scsi_ret;
1224 }
1225
1226 static void tcmu_set_next_deadline(struct list_head *queue,
1227                                    struct timer_list *timer)
1228 {
1229         struct tcmu_cmd *cmd;
1230
1231         if (!list_empty(queue)) {
1232                 cmd = list_first_entry(queue, struct tcmu_cmd, queue_entry);
1233                 mod_timer(timer, cmd->deadline);
1234         } else
1235                 del_timer(timer);
1236 }
1237
1238 static int
1239 tcmu_tmr_type(enum tcm_tmreq_table tmf)
1240 {
1241         switch (tmf) {
1242         case TMR_ABORT_TASK:            return TCMU_TMR_ABORT_TASK;
1243         case TMR_ABORT_TASK_SET:        return TCMU_TMR_ABORT_TASK_SET;
1244         case TMR_CLEAR_ACA:             return TCMU_TMR_CLEAR_ACA;
1245         case TMR_CLEAR_TASK_SET:        return TCMU_TMR_CLEAR_TASK_SET;
1246         case TMR_LUN_RESET:             return TCMU_TMR_LUN_RESET;
1247         case TMR_TARGET_WARM_RESET:     return TCMU_TMR_TARGET_WARM_RESET;
1248         case TMR_TARGET_COLD_RESET:     return TCMU_TMR_TARGET_COLD_RESET;
1249         case TMR_LUN_RESET_PRO:         return TCMU_TMR_LUN_RESET_PRO;
1250         default:                        return TCMU_TMR_UNKNOWN;
1251         }
1252 }
1253
1254 static void
1255 tcmu_tmr_notify(struct se_device *se_dev, enum tcm_tmreq_table tmf,
1256                 struct list_head *cmd_list)
1257 {
1258         int i = 0, cmd_cnt = 0;
1259         bool unqueued = false;
1260         struct tcmu_cmd *cmd;
1261         struct se_cmd *se_cmd;
1262         struct tcmu_tmr *tmr;
1263         struct tcmu_dev *udev = TCMU_DEV(se_dev);
1264
1265         mutex_lock(&udev->cmdr_lock);
1266
1267         /* First we check for aborted commands in qfull_queue */
1268         list_for_each_entry(se_cmd, cmd_list, state_list) {
1269                 i++;
1270                 if (!se_cmd->priv)
1271                         continue;
1272                 cmd = se_cmd->priv;
1273                 /* Commands on qfull queue have no id yet */
1274                 if (cmd->cmd_id) {
1275                         cmd_cnt++;
1276                         continue;
1277                 }
1278                 pr_debug("Removing aborted command %p from queue on dev %s.\n",
1279                          cmd, udev->name);
1280
1281                 list_del_init(&cmd->queue_entry);
1282                 tcmu_free_cmd(cmd);
1283                 se_cmd->priv = NULL;
1284                 target_complete_cmd(se_cmd, SAM_STAT_TASK_ABORTED);
1285                 unqueued = true;
1286         }
1287         if (unqueued)
1288                 tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
1289
1290         if (!test_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags))
1291                 goto unlock;
1292
1293         pr_debug("TMR event %d on dev %s, aborted cmds %d, afflicted cmd_ids %d\n",
1294                  tcmu_tmr_type(tmf), udev->name, i, cmd_cnt);
1295
1296         tmr = kmalloc(struct_size(tmr, tmr_cmd_ids, cmd_cnt), GFP_NOIO);
1297         if (!tmr)
1298                 goto unlock;
1299
1300         tmr->tmr_type = tcmu_tmr_type(tmf);
1301         tmr->tmr_cmd_cnt = cmd_cnt;
1302
1303         if (cmd_cnt != 0) {
1304                 cmd_cnt = 0;
1305                 list_for_each_entry(se_cmd, cmd_list, state_list) {
1306                         if (!se_cmd->priv)
1307                                 continue;
1308                         cmd = se_cmd->priv;
1309                         if (cmd->cmd_id)
1310                                 tmr->tmr_cmd_ids[cmd_cnt++] = cmd->cmd_id;
1311                 }
1312         }
1313
1314         queue_tmr_ring(udev, tmr);
1315
1316 unlock:
1317         mutex_unlock(&udev->cmdr_lock);
1318 }
1319
1320 static bool tcmu_handle_completion(struct tcmu_cmd *cmd,
1321                                    struct tcmu_cmd_entry *entry, bool keep_buf)
1322 {
1323         struct se_cmd *se_cmd = cmd->se_cmd;
1324         struct tcmu_dev *udev = cmd->tcmu_dev;
1325         bool read_len_valid = false;
1326         bool ret = true;
1327         uint32_t read_len;
1328
1329         /*
1330          * cmd has been completed already from timeout, just reclaim
1331          * data area space and free cmd
1332          */
1333         if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
1334                 WARN_ON_ONCE(se_cmd);
1335                 goto out;
1336         }
1337         if (test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags)) {
1338                 pr_err("cmd_id %u already completed with KEEP_BUF, ring is broken\n",
1339                        entry->hdr.cmd_id);
1340                 set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
1341                 ret = false;
1342                 goto out;
1343         }
1344
1345         list_del_init(&cmd->queue_entry);
1346
1347         tcmu_cmd_reset_dbi_cur(cmd);
1348
1349         if (entry->hdr.uflags & TCMU_UFLAG_UNKNOWN_OP) {
1350                 pr_warn("TCMU: Userspace set UNKNOWN_OP flag on se_cmd %p\n",
1351                         cmd->se_cmd);
1352                 entry->rsp.scsi_status = SAM_STAT_CHECK_CONDITION;
1353                 goto done;
1354         }
1355
1356         read_len = se_cmd->data_length;
1357         if (se_cmd->data_direction == DMA_FROM_DEVICE &&
1358             (entry->hdr.uflags & TCMU_UFLAG_READ_LEN) && entry->rsp.read_len) {
1359                 read_len_valid = true;
1360                 if (entry->rsp.read_len < read_len)
1361                         read_len = entry->rsp.read_len;
1362         }
1363
1364         if (entry->rsp.scsi_status == SAM_STAT_CHECK_CONDITION) {
1365                 transport_copy_sense_to_cmd(se_cmd, entry->rsp.sense_buffer);
1366                 if (!read_len_valid )
1367                         goto done;
1368                 else
1369                         se_cmd->se_cmd_flags |= SCF_TREAT_READ_AS_NORMAL;
1370         }
1371         if (se_cmd->se_cmd_flags & SCF_BIDI) {
1372                 /* Get Data-In buffer before clean up */
1373                 gather_data_area(udev, cmd, true, read_len);
1374         } else if (se_cmd->data_direction == DMA_FROM_DEVICE) {
1375                 gather_data_area(udev, cmd, false, read_len);
1376         } else if (se_cmd->data_direction == DMA_TO_DEVICE) {
1377                 /* TODO: */
1378         } else if (se_cmd->data_direction != DMA_NONE) {
1379                 pr_warn("TCMU: data direction was %d!\n",
1380                         se_cmd->data_direction);
1381         }
1382
1383 done:
1384         se_cmd->priv = NULL;
1385         if (read_len_valid) {
1386                 pr_debug("read_len = %d\n", read_len);
1387                 target_complete_cmd_with_length(cmd->se_cmd,
1388                                         entry->rsp.scsi_status, read_len);
1389         } else
1390                 target_complete_cmd(cmd->se_cmd, entry->rsp.scsi_status);
1391
1392 out:
1393         if (!keep_buf) {
1394                 tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
1395                 tcmu_free_cmd(cmd);
1396         } else {
1397                 /*
1398                  * Keep this command after completion, since userspace still
1399                  * needs the data buffer. Mark it with TCMU_CMD_BIT_KEEP_BUF
1400                  * and reset potential TCMU_CMD_BIT_EXPIRED, so we don't accept
1401                  * a second completion later.
1402                  * Userspace can free the buffer later by writing the cmd_id
1403                  * to new action attribute free_kept_buf.
1404                  */
1405                 clear_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags);
1406                 set_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags);
1407         }
1408         return ret;
1409 }
1410
1411 static int tcmu_run_tmr_queue(struct tcmu_dev *udev)
1412 {
1413         struct tcmu_tmr *tmr, *tmp;
1414         LIST_HEAD(tmrs);
1415
1416         if (list_empty(&udev->tmr_queue))
1417                 return 1;
1418
1419         pr_debug("running %s's tmr queue\n", udev->name);
1420
1421         list_splice_init(&udev->tmr_queue, &tmrs);
1422
1423         list_for_each_entry_safe(tmr, tmp, &tmrs, queue_entry) {
1424                 list_del_init(&tmr->queue_entry);
1425
1426                 pr_debug("removing tmr %p on dev %s from queue\n",
1427                          tmr, udev->name);
1428
1429                 if (queue_tmr_ring(udev, tmr)) {
1430                         pr_debug("ran out of space during tmr queue run\n");
1431                         /*
1432                          * tmr was requeued, so just put all tmrs back in
1433                          * the queue
1434                          */
1435                         list_splice_tail(&tmrs, &udev->tmr_queue);
1436                         return 0;
1437                 }
1438         }
1439
1440         return 1;
1441 }
1442
1443 static bool tcmu_handle_completions(struct tcmu_dev *udev)
1444 {
1445         struct tcmu_mailbox *mb;
1446         struct tcmu_cmd *cmd;
1447         bool free_space = false;
1448
1449         if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
1450                 pr_err("ring broken, not handling completions\n");
1451                 return false;
1452         }
1453
1454         mb = udev->mb_addr;
1455         tcmu_flush_dcache_range(mb, sizeof(*mb));
1456
1457         while (udev->cmdr_last_cleaned != READ_ONCE(mb->cmd_tail)) {
1458
1459                 struct tcmu_cmd_entry *entry = udev->cmdr + udev->cmdr_last_cleaned;
1460                 bool keep_buf;
1461
1462                 /*
1463                  * Flush max. up to end of cmd ring since current entry might
1464                  * be a padding that is shorter than sizeof(*entry)
1465                  */
1466                 size_t ring_left = head_to_end(udev->cmdr_last_cleaned,
1467                                                udev->cmdr_size);
1468                 tcmu_flush_dcache_range(entry, ring_left < sizeof(*entry) ?
1469                                         ring_left : sizeof(*entry));
1470
1471                 free_space = true;
1472
1473                 if (tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_PAD ||
1474                     tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_TMR) {
1475                         UPDATE_HEAD(udev->cmdr_last_cleaned,
1476                                     tcmu_hdr_get_len(entry->hdr.len_op),
1477                                     udev->cmdr_size);
1478                         continue;
1479                 }
1480                 WARN_ON(tcmu_hdr_get_op(entry->hdr.len_op) != TCMU_OP_CMD);
1481
1482                 keep_buf = !!(entry->hdr.uflags & TCMU_UFLAG_KEEP_BUF);
1483                 if (keep_buf)
1484                         cmd = xa_load(&udev->commands, entry->hdr.cmd_id);
1485                 else
1486                         cmd = xa_erase(&udev->commands, entry->hdr.cmd_id);
1487                 if (!cmd) {
1488                         pr_err("cmd_id %u not found, ring is broken\n",
1489                                entry->hdr.cmd_id);
1490                         set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
1491                         return false;
1492                 }
1493
1494                 if (!tcmu_handle_completion(cmd, entry, keep_buf))
1495                         break;
1496
1497                 UPDATE_HEAD(udev->cmdr_last_cleaned,
1498                             tcmu_hdr_get_len(entry->hdr.len_op),
1499                             udev->cmdr_size);
1500         }
1501         if (free_space)
1502                 free_space = tcmu_run_tmr_queue(udev);
1503
1504         if (atomic_read(&global_page_count) > tcmu_global_max_pages &&
1505             xa_empty(&udev->commands) && list_empty(&udev->qfull_queue)) {
1506                 /*
1507                  * Allocated blocks exceeded global block limit, currently no
1508                  * more pending or waiting commands so try to reclaim blocks.
1509                  */
1510                 schedule_delayed_work(&tcmu_unmap_work, 0);
1511         }
1512         if (udev->cmd_time_out)
1513                 tcmu_set_next_deadline(&udev->inflight_queue, &udev->cmd_timer);
1514
1515         return free_space;
1516 }
1517
1518 static void tcmu_check_expired_ring_cmd(struct tcmu_cmd *cmd)
1519 {
1520         struct se_cmd *se_cmd;
1521
1522         if (!time_after_eq(jiffies, cmd->deadline))
1523                 return;
1524
1525         set_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags);
1526         list_del_init(&cmd->queue_entry);
1527         se_cmd = cmd->se_cmd;
1528         se_cmd->priv = NULL;
1529         cmd->se_cmd = NULL;
1530
1531         pr_debug("Timing out inflight cmd %u on dev %s.\n",
1532                  cmd->cmd_id, cmd->tcmu_dev->name);
1533
1534         target_complete_cmd(se_cmd, SAM_STAT_CHECK_CONDITION);
1535 }
1536
1537 static void tcmu_check_expired_queue_cmd(struct tcmu_cmd *cmd)
1538 {
1539         struct se_cmd *se_cmd;
1540
1541         if (!time_after_eq(jiffies, cmd->deadline))
1542                 return;
1543
1544         pr_debug("Timing out queued cmd %p on dev %s.\n",
1545                   cmd, cmd->tcmu_dev->name);
1546
1547         list_del_init(&cmd->queue_entry);
1548         se_cmd = cmd->se_cmd;
1549         tcmu_free_cmd(cmd);
1550
1551         se_cmd->priv = NULL;
1552         target_complete_cmd(se_cmd, SAM_STAT_TASK_SET_FULL);
1553 }
1554
1555 static void tcmu_device_timedout(struct tcmu_dev *udev)
1556 {
1557         spin_lock(&timed_out_udevs_lock);
1558         if (list_empty(&udev->timedout_entry))
1559                 list_add_tail(&udev->timedout_entry, &timed_out_udevs);
1560         spin_unlock(&timed_out_udevs_lock);
1561
1562         schedule_delayed_work(&tcmu_unmap_work, 0);
1563 }
1564
1565 static void tcmu_cmd_timedout(struct timer_list *t)
1566 {
1567         struct tcmu_dev *udev = from_timer(udev, t, cmd_timer);
1568
1569         pr_debug("%s cmd timeout has expired\n", udev->name);
1570         tcmu_device_timedout(udev);
1571 }
1572
1573 static void tcmu_qfull_timedout(struct timer_list *t)
1574 {
1575         struct tcmu_dev *udev = from_timer(udev, t, qfull_timer);
1576
1577         pr_debug("%s qfull timeout has expired\n", udev->name);
1578         tcmu_device_timedout(udev);
1579 }
1580
1581 static int tcmu_attach_hba(struct se_hba *hba, u32 host_id)
1582 {
1583         struct tcmu_hba *tcmu_hba;
1584
1585         tcmu_hba = kzalloc(sizeof(struct tcmu_hba), GFP_KERNEL);
1586         if (!tcmu_hba)
1587                 return -ENOMEM;
1588
1589         tcmu_hba->host_id = host_id;
1590         hba->hba_ptr = tcmu_hba;
1591
1592         return 0;
1593 }
1594
1595 static void tcmu_detach_hba(struct se_hba *hba)
1596 {
1597         kfree(hba->hba_ptr);
1598         hba->hba_ptr = NULL;
1599 }
1600
1601 static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name)
1602 {
1603         struct tcmu_dev *udev;
1604
1605         udev = kzalloc(sizeof(struct tcmu_dev), GFP_KERNEL);
1606         if (!udev)
1607                 return NULL;
1608         kref_init(&udev->kref);
1609
1610         udev->name = kstrdup(name, GFP_KERNEL);
1611         if (!udev->name) {
1612                 kfree(udev);
1613                 return NULL;
1614         }
1615
1616         udev->hba = hba;
1617         udev->cmd_time_out = TCMU_TIME_OUT;
1618         udev->qfull_time_out = -1;
1619
1620         udev->data_pages_per_blk = DATA_PAGES_PER_BLK_DEF;
1621         udev->max_blocks = DATA_AREA_PAGES_DEF / udev->data_pages_per_blk;
1622         udev->cmdr_size = CMDR_SIZE_DEF;
1623         udev->data_area_mb = TCMU_PAGES_TO_MBS(DATA_AREA_PAGES_DEF);
1624
1625         mutex_init(&udev->cmdr_lock);
1626
1627         INIT_LIST_HEAD(&udev->node);
1628         INIT_LIST_HEAD(&udev->timedout_entry);
1629         INIT_LIST_HEAD(&udev->qfull_queue);
1630         INIT_LIST_HEAD(&udev->tmr_queue);
1631         INIT_LIST_HEAD(&udev->inflight_queue);
1632         xa_init_flags(&udev->commands, XA_FLAGS_ALLOC1);
1633
1634         timer_setup(&udev->qfull_timer, tcmu_qfull_timedout, 0);
1635         timer_setup(&udev->cmd_timer, tcmu_cmd_timedout, 0);
1636
1637         xa_init(&udev->data_pages);
1638
1639         return &udev->se_dev;
1640 }
1641
1642 static void tcmu_dev_call_rcu(struct rcu_head *p)
1643 {
1644         struct se_device *dev = container_of(p, struct se_device, rcu_head);
1645         struct tcmu_dev *udev = TCMU_DEV(dev);
1646
1647         kfree(udev->uio_info.name);
1648         kfree(udev->name);
1649         kfree(udev);
1650 }
1651
1652 static int tcmu_check_and_free_pending_cmd(struct tcmu_cmd *cmd)
1653 {
1654         if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags) ||
1655             test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags)) {
1656                 kmem_cache_free(tcmu_cmd_cache, cmd);
1657                 return 0;
1658         }
1659         return -EINVAL;
1660 }
1661
1662 static u32 tcmu_blocks_release(struct tcmu_dev *udev, unsigned long first,
1663                                 unsigned long last)
1664 {
1665         struct page *page;
1666         unsigned long dpi;
1667         u32 pages_freed = 0;
1668
1669         first = first * udev->data_pages_per_blk;
1670         last = (last + 1) * udev->data_pages_per_blk - 1;
1671         xa_for_each_range(&udev->data_pages, dpi, page, first, last) {
1672                 xa_erase(&udev->data_pages, dpi);
1673                 /*
1674                  * While reaching here there may be page faults occurring on
1675                  * the to-be-released pages. A race condition may occur if
1676                  * unmap_mapping_range() is called before page faults on these
1677                  * pages have completed; a valid but stale map is created.
1678                  *
1679                  * If another command subsequently runs and needs to extend
1680                  * dbi_thresh, it may reuse the slot corresponding to the
1681                  * previous page in data_bitmap. Though we will allocate a new
1682                  * page for the slot in data_area, no page fault will happen
1683                  * because we have a valid map. Therefore the command's data
1684                  * will be lost.
1685                  *
1686                  * We lock and unlock pages that are to be released to ensure
1687                  * all page faults have completed. This way
1688                  * unmap_mapping_range() can ensure stale maps are cleanly
1689                  * removed.
1690                  */
1691                 lock_page(page);
1692                 unlock_page(page);
1693                 __free_page(page);
1694                 pages_freed++;
1695         }
1696
1697         atomic_sub(pages_freed, &global_page_count);
1698
1699         return pages_freed;
1700 }
1701
1702 static void tcmu_remove_all_queued_tmr(struct tcmu_dev *udev)
1703 {
1704         struct tcmu_tmr *tmr, *tmp;
1705
1706         list_for_each_entry_safe(tmr, tmp, &udev->tmr_queue, queue_entry) {
1707                 list_del_init(&tmr->queue_entry);
1708                 kfree(tmr);
1709         }
1710 }
1711
1712 static void tcmu_dev_kref_release(struct kref *kref)
1713 {
1714         struct tcmu_dev *udev = container_of(kref, struct tcmu_dev, kref);
1715         struct se_device *dev = &udev->se_dev;
1716         struct tcmu_cmd *cmd;
1717         bool all_expired = true;
1718         unsigned long i;
1719
1720         vfree(udev->mb_addr);
1721         udev->mb_addr = NULL;
1722
1723         spin_lock_bh(&timed_out_udevs_lock);
1724         if (!list_empty(&udev->timedout_entry))
1725                 list_del(&udev->timedout_entry);
1726         spin_unlock_bh(&timed_out_udevs_lock);
1727
1728         /* Upper layer should drain all requests before calling this */
1729         mutex_lock(&udev->cmdr_lock);
1730         xa_for_each(&udev->commands, i, cmd) {
1731                 if (tcmu_check_and_free_pending_cmd(cmd) != 0)
1732                         all_expired = false;
1733         }
1734         /* There can be left over TMR cmds. Remove them. */
1735         tcmu_remove_all_queued_tmr(udev);
1736         if (!list_empty(&udev->qfull_queue))
1737                 all_expired = false;
1738         xa_destroy(&udev->commands);
1739         WARN_ON(!all_expired);
1740
1741         tcmu_blocks_release(udev, 0, udev->dbi_max);
1742         bitmap_free(udev->data_bitmap);
1743         mutex_unlock(&udev->cmdr_lock);
1744
1745         pr_debug("dev_kref_release\n");
1746
1747         call_rcu(&dev->rcu_head, tcmu_dev_call_rcu);
1748 }
1749
1750 static void run_qfull_queue(struct tcmu_dev *udev, bool fail)
1751 {
1752         struct tcmu_cmd *tcmu_cmd, *tmp_cmd;
1753         LIST_HEAD(cmds);
1754         sense_reason_t scsi_ret;
1755         int ret;
1756
1757         if (list_empty(&udev->qfull_queue))
1758                 return;
1759
1760         pr_debug("running %s's cmdr queue forcefail %d\n", udev->name, fail);
1761
1762         list_splice_init(&udev->qfull_queue, &cmds);
1763
1764         list_for_each_entry_safe(tcmu_cmd, tmp_cmd, &cmds, queue_entry) {
1765                 list_del_init(&tcmu_cmd->queue_entry);
1766
1767                 pr_debug("removing cmd %p on dev %s from queue\n",
1768                          tcmu_cmd, udev->name);
1769
1770                 if (fail) {
1771                         /*
1772                          * We were not able to even start the command, so
1773                          * fail with busy to allow a retry in case runner
1774                          * was only temporarily down. If the device is being
1775                          * removed then LIO core will do the right thing and
1776                          * fail the retry.
1777                          */
1778                         tcmu_cmd->se_cmd->priv = NULL;
1779                         target_complete_cmd(tcmu_cmd->se_cmd, SAM_STAT_BUSY);
1780                         tcmu_free_cmd(tcmu_cmd);
1781                         continue;
1782                 }
1783
1784                 ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
1785                 if (ret < 0) {
1786                         pr_debug("cmd %p on dev %s failed with %u\n",
1787                                  tcmu_cmd, udev->name, scsi_ret);
1788                         /*
1789                          * Ignore scsi_ret for now. target_complete_cmd
1790                          * drops it.
1791                          */
1792                         tcmu_cmd->se_cmd->priv = NULL;
1793                         target_complete_cmd(tcmu_cmd->se_cmd,
1794                                             SAM_STAT_CHECK_CONDITION);
1795                         tcmu_free_cmd(tcmu_cmd);
1796                 } else if (ret > 0) {
1797                         pr_debug("ran out of space during cmdr queue run\n");
1798                         /*
1799                          * cmd was requeued, so just put all cmds back in
1800                          * the queue
1801                          */
1802                         list_splice_tail(&cmds, &udev->qfull_queue);
1803                         break;
1804                 }
1805         }
1806
1807         tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
1808 }
1809
1810 static int tcmu_irqcontrol(struct uio_info *info, s32 irq_on)
1811 {
1812         struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1813
1814         mutex_lock(&udev->cmdr_lock);
1815         if (tcmu_handle_completions(udev))
1816                 run_qfull_queue(udev, false);
1817         mutex_unlock(&udev->cmdr_lock);
1818
1819         return 0;
1820 }
1821
1822 /*
1823  * mmap code from uio.c. Copied here because we want to hook mmap()
1824  * and this stuff must come along.
1825  */
1826 static int tcmu_find_mem_index(struct vm_area_struct *vma)
1827 {
1828         struct tcmu_dev *udev = vma->vm_private_data;
1829         struct uio_info *info = &udev->uio_info;
1830
1831         if (vma->vm_pgoff < MAX_UIO_MAPS) {
1832                 if (info->mem[vma->vm_pgoff].size == 0)
1833                         return -1;
1834                 return (int)vma->vm_pgoff;
1835         }
1836         return -1;
1837 }
1838
1839 static struct page *tcmu_try_get_data_page(struct tcmu_dev *udev, uint32_t dpi)
1840 {
1841         struct page *page;
1842
1843         mutex_lock(&udev->cmdr_lock);
1844         page = xa_load(&udev->data_pages, dpi);
1845         if (likely(page)) {
1846                 get_page(page);
1847                 lock_page(page);
1848                 mutex_unlock(&udev->cmdr_lock);
1849                 return page;
1850         }
1851
1852         /*
1853          * Userspace messed up and passed in a address not in the
1854          * data iov passed to it.
1855          */
1856         pr_err("Invalid addr to data page mapping (dpi %u) on device %s\n",
1857                dpi, udev->name);
1858         mutex_unlock(&udev->cmdr_lock);
1859
1860         return NULL;
1861 }
1862
1863 static void tcmu_vma_open(struct vm_area_struct *vma)
1864 {
1865         struct tcmu_dev *udev = vma->vm_private_data;
1866
1867         pr_debug("vma_open\n");
1868
1869         kref_get(&udev->kref);
1870 }
1871
1872 static void tcmu_vma_close(struct vm_area_struct *vma)
1873 {
1874         struct tcmu_dev *udev = vma->vm_private_data;
1875
1876         pr_debug("vma_close\n");
1877
1878         /* release ref from tcmu_vma_open */
1879         kref_put(&udev->kref, tcmu_dev_kref_release);
1880 }
1881
1882 static vm_fault_t tcmu_vma_fault(struct vm_fault *vmf)
1883 {
1884         struct tcmu_dev *udev = vmf->vma->vm_private_data;
1885         struct uio_info *info = &udev->uio_info;
1886         struct page *page;
1887         unsigned long offset;
1888         void *addr;
1889         vm_fault_t ret = 0;
1890
1891         int mi = tcmu_find_mem_index(vmf->vma);
1892         if (mi < 0)
1893                 return VM_FAULT_SIGBUS;
1894
1895         /*
1896          * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
1897          * to use mem[N].
1898          */
1899         offset = (vmf->pgoff - mi) << PAGE_SHIFT;
1900
1901         if (offset < udev->data_off) {
1902                 /* For the vmalloc()ed cmd area pages */
1903                 addr = (void *)(unsigned long)info->mem[mi].addr + offset;
1904                 page = vmalloc_to_page(addr);
1905                 get_page(page);
1906         } else {
1907                 uint32_t dpi;
1908
1909                 /* For the dynamically growing data area pages */
1910                 dpi = (offset - udev->data_off) / PAGE_SIZE;
1911                 page = tcmu_try_get_data_page(udev, dpi);
1912                 if (!page)
1913                         return VM_FAULT_SIGBUS;
1914                 ret = VM_FAULT_LOCKED;
1915         }
1916
1917         vmf->page = page;
1918         return ret;
1919 }
1920
1921 static const struct vm_operations_struct tcmu_vm_ops = {
1922         .open = tcmu_vma_open,
1923         .close = tcmu_vma_close,
1924         .fault = tcmu_vma_fault,
1925 };
1926
1927 static int tcmu_mmap(struct uio_info *info, struct vm_area_struct *vma)
1928 {
1929         struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1930
1931         vm_flags_set(vma, VM_DONTEXPAND | VM_DONTDUMP);
1932         vma->vm_ops = &tcmu_vm_ops;
1933
1934         vma->vm_private_data = udev;
1935
1936         /* Ensure the mmap is exactly the right size */
1937         if (vma_pages(vma) != udev->mmap_pages)
1938                 return -EINVAL;
1939
1940         tcmu_vma_open(vma);
1941
1942         return 0;
1943 }
1944
1945 static int tcmu_open(struct uio_info *info, struct inode *inode)
1946 {
1947         struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1948
1949         /* O_EXCL not supported for char devs, so fake it? */
1950         if (test_and_set_bit(TCMU_DEV_BIT_OPEN, &udev->flags))
1951                 return -EBUSY;
1952
1953         udev->inode = inode;
1954
1955         pr_debug("open\n");
1956
1957         return 0;
1958 }
1959
1960 static int tcmu_release(struct uio_info *info, struct inode *inode)
1961 {
1962         struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1963         struct tcmu_cmd *cmd;
1964         unsigned long i;
1965         bool freed = false;
1966
1967         mutex_lock(&udev->cmdr_lock);
1968
1969         xa_for_each(&udev->commands, i, cmd) {
1970                 /* Cmds with KEEP_BUF set are no longer on the ring, but
1971                  * userspace still holds the data buffer. If userspace closes
1972                  * we implicitly free these cmds and buffers, since after new
1973                  * open the (new ?) userspace cannot find the cmd in the ring
1974                  * and thus never will release the buffer by writing cmd_id to
1975                  * free_kept_buf action attribute.
1976                  */
1977                 if (!test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags))
1978                         continue;
1979                 pr_debug("removing KEEP_BUF cmd %u on dev %s from ring\n",
1980                          cmd->cmd_id, udev->name);
1981                 freed = true;
1982
1983                 xa_erase(&udev->commands, i);
1984                 tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
1985                 tcmu_free_cmd(cmd);
1986         }
1987         /*
1988          * We only freed data space, not ring space. Therefore we dont call
1989          * run_tmr_queue, but call run_qfull_queue if tmr_list is empty.
1990          */
1991         if (freed && list_empty(&udev->tmr_queue))
1992                 run_qfull_queue(udev, false);
1993
1994         mutex_unlock(&udev->cmdr_lock);
1995
1996         clear_bit(TCMU_DEV_BIT_OPEN, &udev->flags);
1997
1998         pr_debug("close\n");
1999
2000         return 0;
2001 }
2002
2003 static int tcmu_init_genl_cmd_reply(struct tcmu_dev *udev, int cmd)
2004 {
2005         struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
2006
2007         if (!tcmu_kern_cmd_reply_supported)
2008                 return 0;
2009
2010         if (udev->nl_reply_supported <= 0)
2011                 return 0;
2012
2013         mutex_lock(&tcmu_nl_cmd_mutex);
2014
2015         if (tcmu_netlink_blocked) {
2016                 mutex_unlock(&tcmu_nl_cmd_mutex);
2017                 pr_warn("Failing nl cmd %d on %s. Interface is blocked.\n", cmd,
2018                         udev->name);
2019                 return -EAGAIN;
2020         }
2021
2022         if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
2023                 mutex_unlock(&tcmu_nl_cmd_mutex);
2024                 pr_warn("netlink cmd %d already executing on %s\n",
2025                          nl_cmd->cmd, udev->name);
2026                 return -EBUSY;
2027         }
2028
2029         memset(nl_cmd, 0, sizeof(*nl_cmd));
2030         nl_cmd->cmd = cmd;
2031         nl_cmd->udev = udev;
2032         init_completion(&nl_cmd->complete);
2033         INIT_LIST_HEAD(&nl_cmd->nl_list);
2034
2035         list_add_tail(&nl_cmd->nl_list, &tcmu_nl_cmd_list);
2036
2037         mutex_unlock(&tcmu_nl_cmd_mutex);
2038         return 0;
2039 }
2040
2041 static void tcmu_destroy_genl_cmd_reply(struct tcmu_dev *udev)
2042 {
2043         struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
2044
2045         if (!tcmu_kern_cmd_reply_supported)
2046                 return;
2047
2048         if (udev->nl_reply_supported <= 0)
2049                 return;
2050
2051         mutex_lock(&tcmu_nl_cmd_mutex);
2052
2053         list_del(&nl_cmd->nl_list);
2054         memset(nl_cmd, 0, sizeof(*nl_cmd));
2055
2056         mutex_unlock(&tcmu_nl_cmd_mutex);
2057 }
2058
2059 static int tcmu_wait_genl_cmd_reply(struct tcmu_dev *udev)
2060 {
2061         struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
2062         int ret;
2063
2064         if (!tcmu_kern_cmd_reply_supported)
2065                 return 0;
2066
2067         if (udev->nl_reply_supported <= 0)
2068                 return 0;
2069
2070         pr_debug("sleeping for nl reply\n");
2071         wait_for_completion(&nl_cmd->complete);
2072
2073         mutex_lock(&tcmu_nl_cmd_mutex);
2074         nl_cmd->cmd = TCMU_CMD_UNSPEC;
2075         ret = nl_cmd->status;
2076         mutex_unlock(&tcmu_nl_cmd_mutex);
2077
2078         return ret;
2079 }
2080
2081 static int tcmu_netlink_event_init(struct tcmu_dev *udev,
2082                                    enum tcmu_genl_cmd cmd,
2083                                    struct sk_buff **buf, void **hdr)
2084 {
2085         struct sk_buff *skb;
2086         void *msg_header;
2087         int ret = -ENOMEM;
2088
2089         skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2090         if (!skb)
2091                 return ret;
2092
2093         msg_header = genlmsg_put(skb, 0, 0, &tcmu_genl_family, 0, cmd);
2094         if (!msg_header)
2095                 goto free_skb;
2096
2097         ret = nla_put_string(skb, TCMU_ATTR_DEVICE, udev->uio_info.name);
2098         if (ret < 0)
2099                 goto free_skb;
2100
2101         ret = nla_put_u32(skb, TCMU_ATTR_MINOR, udev->uio_info.uio_dev->minor);
2102         if (ret < 0)
2103                 goto free_skb;
2104
2105         ret = nla_put_u32(skb, TCMU_ATTR_DEVICE_ID, udev->se_dev.dev_index);
2106         if (ret < 0)
2107                 goto free_skb;
2108
2109         *buf = skb;
2110         *hdr = msg_header;
2111         return ret;
2112
2113 free_skb:
2114         nlmsg_free(skb);
2115         return ret;
2116 }
2117
2118 static int tcmu_netlink_event_send(struct tcmu_dev *udev,
2119                                    enum tcmu_genl_cmd cmd,
2120                                    struct sk_buff *skb, void *msg_header)
2121 {
2122         int ret;
2123
2124         genlmsg_end(skb, msg_header);
2125
2126         ret = tcmu_init_genl_cmd_reply(udev, cmd);
2127         if (ret) {
2128                 nlmsg_free(skb);
2129                 return ret;
2130         }
2131
2132         ret = genlmsg_multicast_allns(&tcmu_genl_family, skb, 0,
2133                                       TCMU_MCGRP_CONFIG, GFP_KERNEL);
2134
2135         /* Wait during an add as the listener may not be up yet */
2136         if (ret == 0 ||
2137            (ret == -ESRCH && cmd == TCMU_CMD_ADDED_DEVICE))
2138                 return tcmu_wait_genl_cmd_reply(udev);
2139         else
2140                 tcmu_destroy_genl_cmd_reply(udev);
2141
2142         return ret;
2143 }
2144
2145 static int tcmu_send_dev_add_event(struct tcmu_dev *udev)
2146 {
2147         struct sk_buff *skb = NULL;
2148         void *msg_header = NULL;
2149         int ret = 0;
2150
2151         ret = tcmu_netlink_event_init(udev, TCMU_CMD_ADDED_DEVICE, &skb,
2152                                       &msg_header);
2153         if (ret < 0)
2154                 return ret;
2155         return tcmu_netlink_event_send(udev, TCMU_CMD_ADDED_DEVICE, skb,
2156                                        msg_header);
2157 }
2158
2159 static int tcmu_send_dev_remove_event(struct tcmu_dev *udev)
2160 {
2161         struct sk_buff *skb = NULL;
2162         void *msg_header = NULL;
2163         int ret = 0;
2164
2165         ret = tcmu_netlink_event_init(udev, TCMU_CMD_REMOVED_DEVICE,
2166                                       &skb, &msg_header);
2167         if (ret < 0)
2168                 return ret;
2169         return tcmu_netlink_event_send(udev, TCMU_CMD_REMOVED_DEVICE,
2170                                        skb, msg_header);
2171 }
2172
2173 static int tcmu_update_uio_info(struct tcmu_dev *udev)
2174 {
2175         struct tcmu_hba *hba = udev->hba->hba_ptr;
2176         struct uio_info *info;
2177         char *str;
2178
2179         info = &udev->uio_info;
2180
2181         if (udev->dev_config[0])
2182                 str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s/%s", hba->host_id,
2183                                 udev->name, udev->dev_config);
2184         else
2185                 str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s", hba->host_id,
2186                                 udev->name);
2187         if (!str)
2188                 return -ENOMEM;
2189
2190         /* If the old string exists, free it */
2191         kfree(info->name);
2192         info->name = str;
2193
2194         return 0;
2195 }
2196
2197 static int tcmu_configure_device(struct se_device *dev)
2198 {
2199         struct tcmu_dev *udev = TCMU_DEV(dev);
2200         struct uio_info *info;
2201         struct tcmu_mailbox *mb;
2202         size_t data_size;
2203         int ret = 0;
2204
2205         ret = tcmu_update_uio_info(udev);
2206         if (ret)
2207                 return ret;
2208
2209         info = &udev->uio_info;
2210
2211         mutex_lock(&udev->cmdr_lock);
2212         udev->data_bitmap = bitmap_zalloc(udev->max_blocks, GFP_KERNEL);
2213         mutex_unlock(&udev->cmdr_lock);
2214         if (!udev->data_bitmap) {
2215                 ret = -ENOMEM;
2216                 goto err_bitmap_alloc;
2217         }
2218
2219         mb = vzalloc(udev->cmdr_size + CMDR_OFF);
2220         if (!mb) {
2221                 ret = -ENOMEM;
2222                 goto err_vzalloc;
2223         }
2224
2225         /* mailbox fits in first part of CMDR space */
2226         udev->mb_addr = mb;
2227         udev->cmdr = (void *)mb + CMDR_OFF;
2228         udev->data_off = udev->cmdr_size + CMDR_OFF;
2229         data_size = TCMU_MBS_TO_PAGES(udev->data_area_mb) << PAGE_SHIFT;
2230         udev->mmap_pages = (data_size + udev->cmdr_size + CMDR_OFF) >> PAGE_SHIFT;
2231         udev->data_blk_size = udev->data_pages_per_blk * PAGE_SIZE;
2232         udev->dbi_thresh = 0; /* Default in Idle state */
2233
2234         /* Initialise the mailbox of the ring buffer */
2235         mb->version = TCMU_MAILBOX_VERSION;
2236         mb->flags = TCMU_MAILBOX_FLAG_CAP_OOOC |
2237                     TCMU_MAILBOX_FLAG_CAP_READ_LEN |
2238                     TCMU_MAILBOX_FLAG_CAP_TMR |
2239                     TCMU_MAILBOX_FLAG_CAP_KEEP_BUF;
2240         mb->cmdr_off = CMDR_OFF;
2241         mb->cmdr_size = udev->cmdr_size;
2242
2243         WARN_ON(!PAGE_ALIGNED(udev->data_off));
2244         WARN_ON(data_size % PAGE_SIZE);
2245
2246         info->version = __stringify(TCMU_MAILBOX_VERSION);
2247
2248         info->mem[0].name = "tcm-user command & data buffer";
2249         info->mem[0].addr = (phys_addr_t)(uintptr_t)udev->mb_addr;
2250         info->mem[0].size = data_size + udev->cmdr_size + CMDR_OFF;
2251         info->mem[0].memtype = UIO_MEM_NONE;
2252
2253         info->irqcontrol = tcmu_irqcontrol;
2254         info->irq = UIO_IRQ_CUSTOM;
2255
2256         info->mmap = tcmu_mmap;
2257         info->open = tcmu_open;
2258         info->release = tcmu_release;
2259
2260         ret = uio_register_device(tcmu_root_device, info);
2261         if (ret)
2262                 goto err_register;
2263
2264         /* User can set hw_block_size before enable the device */
2265         if (dev->dev_attrib.hw_block_size == 0)
2266                 dev->dev_attrib.hw_block_size = 512;
2267         /* Other attributes can be configured in userspace */
2268         if (!dev->dev_attrib.hw_max_sectors)
2269                 dev->dev_attrib.hw_max_sectors = 128;
2270         if (!dev->dev_attrib.emulate_write_cache)
2271                 dev->dev_attrib.emulate_write_cache = 0;
2272         dev->dev_attrib.hw_queue_depth = 128;
2273
2274         /* If user didn't explicitly disable netlink reply support, use
2275          * module scope setting.
2276          */
2277         if (udev->nl_reply_supported >= 0)
2278                 udev->nl_reply_supported = tcmu_kern_cmd_reply_supported;
2279
2280         /*
2281          * Get a ref incase userspace does a close on the uio device before
2282          * LIO has initiated tcmu_free_device.
2283          */
2284         kref_get(&udev->kref);
2285
2286         ret = tcmu_send_dev_add_event(udev);
2287         if (ret)
2288                 goto err_netlink;
2289
2290         mutex_lock(&root_udev_mutex);
2291         list_add(&udev->node, &root_udev);
2292         mutex_unlock(&root_udev_mutex);
2293
2294         return 0;
2295
2296 err_netlink:
2297         kref_put(&udev->kref, tcmu_dev_kref_release);
2298         uio_unregister_device(&udev->uio_info);
2299 err_register:
2300         vfree(udev->mb_addr);
2301         udev->mb_addr = NULL;
2302 err_vzalloc:
2303         bitmap_free(udev->data_bitmap);
2304         udev->data_bitmap = NULL;
2305 err_bitmap_alloc:
2306         kfree(info->name);
2307         info->name = NULL;
2308
2309         return ret;
2310 }
2311
2312 static void tcmu_free_device(struct se_device *dev)
2313 {
2314         struct tcmu_dev *udev = TCMU_DEV(dev);
2315
2316         /* release ref from init */
2317         kref_put(&udev->kref, tcmu_dev_kref_release);
2318 }
2319
2320 static void tcmu_destroy_device(struct se_device *dev)
2321 {
2322         struct tcmu_dev *udev = TCMU_DEV(dev);
2323
2324         del_timer_sync(&udev->cmd_timer);
2325         del_timer_sync(&udev->qfull_timer);
2326
2327         mutex_lock(&root_udev_mutex);
2328         list_del(&udev->node);
2329         mutex_unlock(&root_udev_mutex);
2330
2331         tcmu_send_dev_remove_event(udev);
2332
2333         uio_unregister_device(&udev->uio_info);
2334
2335         /* release ref from configure */
2336         kref_put(&udev->kref, tcmu_dev_kref_release);
2337 }
2338
2339 static void tcmu_unblock_dev(struct tcmu_dev *udev)
2340 {
2341         mutex_lock(&udev->cmdr_lock);
2342         clear_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags);
2343         mutex_unlock(&udev->cmdr_lock);
2344 }
2345
2346 static void tcmu_block_dev(struct tcmu_dev *udev)
2347 {
2348         mutex_lock(&udev->cmdr_lock);
2349
2350         if (test_and_set_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
2351                 goto unlock;
2352
2353         /* complete IO that has executed successfully */
2354         tcmu_handle_completions(udev);
2355         /* fail IO waiting to be queued */
2356         run_qfull_queue(udev, true);
2357
2358 unlock:
2359         mutex_unlock(&udev->cmdr_lock);
2360 }
2361
2362 static void tcmu_reset_ring(struct tcmu_dev *udev, u8 err_level)
2363 {
2364         struct tcmu_mailbox *mb;
2365         struct tcmu_cmd *cmd;
2366         unsigned long i;
2367
2368         mutex_lock(&udev->cmdr_lock);
2369
2370         xa_for_each(&udev->commands, i, cmd) {
2371                 pr_debug("removing cmd %u on dev %s from ring %s\n",
2372                          cmd->cmd_id, udev->name,
2373                          test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags) ?
2374                          "(is expired)" :
2375                          (test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags) ?
2376                          "(is keep buffer)" : ""));
2377
2378                 xa_erase(&udev->commands, i);
2379                 if (!test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags) &&
2380                     !test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags)) {
2381                         WARN_ON(!cmd->se_cmd);
2382                         list_del_init(&cmd->queue_entry);
2383                         cmd->se_cmd->priv = NULL;
2384                         if (err_level == 1) {
2385                                 /*
2386                                  * Userspace was not able to start the
2387                                  * command or it is retryable.
2388                                  */
2389                                 target_complete_cmd(cmd->se_cmd, SAM_STAT_BUSY);
2390                         } else {
2391                                 /* hard failure */
2392                                 target_complete_cmd(cmd->se_cmd,
2393                                                     SAM_STAT_CHECK_CONDITION);
2394                         }
2395                 }
2396                 tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
2397                 tcmu_free_cmd(cmd);
2398         }
2399
2400         mb = udev->mb_addr;
2401         tcmu_flush_dcache_range(mb, sizeof(*mb));
2402         pr_debug("mb last %u head %u tail %u\n", udev->cmdr_last_cleaned,
2403                  mb->cmd_tail, mb->cmd_head);
2404
2405         udev->cmdr_last_cleaned = 0;
2406         mb->cmd_tail = 0;
2407         mb->cmd_head = 0;
2408         tcmu_flush_dcache_range(mb, sizeof(*mb));
2409         clear_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
2410
2411         del_timer(&udev->cmd_timer);
2412
2413         /*
2414          * ring is empty and qfull queue never contains aborted commands.
2415          * So TMRs in tmr queue do not contain relevant cmd_ids.
2416          * After a ring reset userspace should do a fresh start, so
2417          * even LUN RESET message is no longer relevant.
2418          * Therefore remove all TMRs from qfull queue
2419          */
2420         tcmu_remove_all_queued_tmr(udev);
2421
2422         run_qfull_queue(udev, false);
2423
2424         mutex_unlock(&udev->cmdr_lock);
2425 }
2426
2427 enum {
2428         Opt_dev_config, Opt_dev_size, Opt_hw_block_size, Opt_hw_max_sectors,
2429         Opt_nl_reply_supported, Opt_max_data_area_mb, Opt_data_pages_per_blk,
2430         Opt_cmd_ring_size_mb, Opt_err,
2431 };
2432
2433 static match_table_t tokens = {
2434         {Opt_dev_config, "dev_config=%s"},
2435         {Opt_dev_size, "dev_size=%s"},
2436         {Opt_hw_block_size, "hw_block_size=%d"},
2437         {Opt_hw_max_sectors, "hw_max_sectors=%d"},
2438         {Opt_nl_reply_supported, "nl_reply_supported=%d"},
2439         {Opt_max_data_area_mb, "max_data_area_mb=%d"},
2440         {Opt_data_pages_per_blk, "data_pages_per_blk=%d"},
2441         {Opt_cmd_ring_size_mb, "cmd_ring_size_mb=%d"},
2442         {Opt_err, NULL}
2443 };
2444
2445 static int tcmu_set_dev_attrib(substring_t *arg, u32 *dev_attrib)
2446 {
2447         int val, ret;
2448
2449         ret = match_int(arg, &val);
2450         if (ret < 0) {
2451                 pr_err("match_int() failed for dev attrib. Error %d.\n",
2452                        ret);
2453                 return ret;
2454         }
2455
2456         if (val <= 0) {
2457                 pr_err("Invalid dev attrib value %d. Must be greater than zero.\n",
2458                        val);
2459                 return -EINVAL;
2460         }
2461         *dev_attrib = val;
2462         return 0;
2463 }
2464
2465 static int tcmu_set_max_blocks_param(struct tcmu_dev *udev, substring_t *arg)
2466 {
2467         int val, ret;
2468         uint32_t pages_per_blk = udev->data_pages_per_blk;
2469
2470         ret = match_int(arg, &val);
2471         if (ret < 0) {
2472                 pr_err("match_int() failed for max_data_area_mb=. Error %d.\n",
2473                        ret);
2474                 return ret;
2475         }
2476         if (val <= 0) {
2477                 pr_err("Invalid max_data_area %d.\n", val);
2478                 return -EINVAL;
2479         }
2480         if (val > TCMU_PAGES_TO_MBS(tcmu_global_max_pages)) {
2481                 pr_err("%d is too large. Adjusting max_data_area_mb to global limit of %u\n",
2482                        val, TCMU_PAGES_TO_MBS(tcmu_global_max_pages));
2483                 val = TCMU_PAGES_TO_MBS(tcmu_global_max_pages);
2484         }
2485         if (TCMU_MBS_TO_PAGES(val) < pages_per_blk) {
2486                 pr_err("Invalid max_data_area %d (%zu pages): smaller than data_pages_per_blk (%u pages).\n",
2487                        val, TCMU_MBS_TO_PAGES(val), pages_per_blk);
2488                 return -EINVAL;
2489         }
2490
2491         mutex_lock(&udev->cmdr_lock);
2492         if (udev->data_bitmap) {
2493                 pr_err("Cannot set max_data_area_mb after it has been enabled.\n");
2494                 ret = -EINVAL;
2495                 goto unlock;
2496         }
2497
2498         udev->data_area_mb = val;
2499         udev->max_blocks = TCMU_MBS_TO_PAGES(val) / pages_per_blk;
2500
2501 unlock:
2502         mutex_unlock(&udev->cmdr_lock);
2503         return ret;
2504 }
2505
2506 static int tcmu_set_data_pages_per_blk(struct tcmu_dev *udev, substring_t *arg)
2507 {
2508         int val, ret;
2509
2510         ret = match_int(arg, &val);
2511         if (ret < 0) {
2512                 pr_err("match_int() failed for data_pages_per_blk=. Error %d.\n",
2513                        ret);
2514                 return ret;
2515         }
2516
2517         if (val > TCMU_MBS_TO_PAGES(udev->data_area_mb)) {
2518                 pr_err("Invalid data_pages_per_blk %d: greater than max_data_area_mb %d -> %zd pages).\n",
2519                        val, udev->data_area_mb,
2520                        TCMU_MBS_TO_PAGES(udev->data_area_mb));
2521                 return -EINVAL;
2522         }
2523
2524         mutex_lock(&udev->cmdr_lock);
2525         if (udev->data_bitmap) {
2526                 pr_err("Cannot set data_pages_per_blk after it has been enabled.\n");
2527                 ret = -EINVAL;
2528                 goto unlock;
2529         }
2530
2531         udev->data_pages_per_blk = val;
2532         udev->max_blocks = TCMU_MBS_TO_PAGES(udev->data_area_mb) / val;
2533
2534 unlock:
2535         mutex_unlock(&udev->cmdr_lock);
2536         return ret;
2537 }
2538
2539 static int tcmu_set_cmd_ring_size(struct tcmu_dev *udev, substring_t *arg)
2540 {
2541         int val, ret;
2542
2543         ret = match_int(arg, &val);
2544         if (ret < 0) {
2545                 pr_err("match_int() failed for cmd_ring_size_mb=. Error %d.\n",
2546                        ret);
2547                 return ret;
2548         }
2549
2550         if (val <= 0) {
2551                 pr_err("Invalid cmd_ring_size_mb %d.\n", val);
2552                 return -EINVAL;
2553         }
2554
2555         mutex_lock(&udev->cmdr_lock);
2556         if (udev->data_bitmap) {
2557                 pr_err("Cannot set cmd_ring_size_mb after it has been enabled.\n");
2558                 ret = -EINVAL;
2559                 goto unlock;
2560         }
2561
2562         udev->cmdr_size = (val << 20) - CMDR_OFF;
2563         if (val > (MB_CMDR_SIZE_DEF >> 20)) {
2564                 pr_err("%d is too large. Adjusting cmd_ring_size_mb to global limit of %u\n",
2565                        val, (MB_CMDR_SIZE_DEF >> 20));
2566                 udev->cmdr_size = CMDR_SIZE_DEF;
2567         }
2568
2569 unlock:
2570         mutex_unlock(&udev->cmdr_lock);
2571         return ret;
2572 }
2573
2574 static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev,
2575                 const char *page, ssize_t count)
2576 {
2577         struct tcmu_dev *udev = TCMU_DEV(dev);
2578         char *orig, *ptr, *opts;
2579         substring_t args[MAX_OPT_ARGS];
2580         int ret = 0, token;
2581
2582         opts = kstrdup(page, GFP_KERNEL);
2583         if (!opts)
2584                 return -ENOMEM;
2585
2586         orig = opts;
2587
2588         while ((ptr = strsep(&opts, ",\n")) != NULL) {
2589                 if (!*ptr)
2590                         continue;
2591
2592                 token = match_token(ptr, tokens, args);
2593                 switch (token) {
2594                 case Opt_dev_config:
2595                         if (match_strlcpy(udev->dev_config, &args[0],
2596                                           TCMU_CONFIG_LEN) == 0) {
2597                                 ret = -EINVAL;
2598                                 break;
2599                         }
2600                         pr_debug("TCMU: Referencing Path: %s\n", udev->dev_config);
2601                         break;
2602                 case Opt_dev_size:
2603                         ret = match_u64(&args[0], &udev->dev_size);
2604                         if (ret < 0)
2605                                 pr_err("match_u64() failed for dev_size=. Error %d.\n",
2606                                        ret);
2607                         break;
2608                 case Opt_hw_block_size:
2609                         ret = tcmu_set_dev_attrib(&args[0],
2610                                         &(dev->dev_attrib.hw_block_size));
2611                         break;
2612                 case Opt_hw_max_sectors:
2613                         ret = tcmu_set_dev_attrib(&args[0],
2614                                         &(dev->dev_attrib.hw_max_sectors));
2615                         break;
2616                 case Opt_nl_reply_supported:
2617                         ret = match_int(&args[0], &udev->nl_reply_supported);
2618                         if (ret < 0)
2619                                 pr_err("match_int() failed for nl_reply_supported=. Error %d.\n",
2620                                        ret);
2621                         break;
2622                 case Opt_max_data_area_mb:
2623                         ret = tcmu_set_max_blocks_param(udev, &args[0]);
2624                         break;
2625                 case Opt_data_pages_per_blk:
2626                         ret = tcmu_set_data_pages_per_blk(udev, &args[0]);
2627                         break;
2628                 case Opt_cmd_ring_size_mb:
2629                         ret = tcmu_set_cmd_ring_size(udev, &args[0]);
2630                         break;
2631                 default:
2632                         break;
2633                 }
2634
2635                 if (ret)
2636                         break;
2637         }
2638
2639         kfree(orig);
2640         return (!ret) ? count : ret;
2641 }
2642
2643 static ssize_t tcmu_show_configfs_dev_params(struct se_device *dev, char *b)
2644 {
2645         struct tcmu_dev *udev = TCMU_DEV(dev);
2646         ssize_t bl = 0;
2647
2648         bl = sprintf(b + bl, "Config: %s ",
2649                      udev->dev_config[0] ? udev->dev_config : "NULL");
2650         bl += sprintf(b + bl, "Size: %llu ", udev->dev_size);
2651         bl += sprintf(b + bl, "MaxDataAreaMB: %u ", udev->data_area_mb);
2652         bl += sprintf(b + bl, "DataPagesPerBlk: %u ", udev->data_pages_per_blk);
2653         bl += sprintf(b + bl, "CmdRingSizeMB: %u\n",
2654                       (udev->cmdr_size + CMDR_OFF) >> 20);
2655
2656         return bl;
2657 }
2658
2659 static sector_t tcmu_get_blocks(struct se_device *dev)
2660 {
2661         struct tcmu_dev *udev = TCMU_DEV(dev);
2662
2663         return div_u64(udev->dev_size - dev->dev_attrib.block_size,
2664                        dev->dev_attrib.block_size);
2665 }
2666
2667 static sense_reason_t
2668 tcmu_parse_cdb(struct se_cmd *cmd)
2669 {
2670         return passthrough_parse_cdb(cmd, tcmu_queue_cmd);
2671 }
2672
2673 static ssize_t tcmu_cmd_time_out_show(struct config_item *item, char *page)
2674 {
2675         struct se_dev_attrib *da = container_of(to_config_group(item),
2676                                         struct se_dev_attrib, da_group);
2677         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2678
2679         return snprintf(page, PAGE_SIZE, "%lu\n", udev->cmd_time_out / MSEC_PER_SEC);
2680 }
2681
2682 static ssize_t tcmu_cmd_time_out_store(struct config_item *item, const char *page,
2683                                        size_t count)
2684 {
2685         struct se_dev_attrib *da = container_of(to_config_group(item),
2686                                         struct se_dev_attrib, da_group);
2687         struct tcmu_dev *udev = container_of(da->da_dev,
2688                                         struct tcmu_dev, se_dev);
2689         u32 val;
2690         int ret;
2691
2692         if (da->da_dev->export_count) {
2693                 pr_err("Unable to set tcmu cmd_time_out while exports exist\n");
2694                 return -EINVAL;
2695         }
2696
2697         ret = kstrtou32(page, 0, &val);
2698         if (ret < 0)
2699                 return ret;
2700
2701         udev->cmd_time_out = val * MSEC_PER_SEC;
2702         return count;
2703 }
2704 CONFIGFS_ATTR(tcmu_, cmd_time_out);
2705
2706 static ssize_t tcmu_qfull_time_out_show(struct config_item *item, char *page)
2707 {
2708         struct se_dev_attrib *da = container_of(to_config_group(item),
2709                                                 struct se_dev_attrib, da_group);
2710         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2711
2712         return snprintf(page, PAGE_SIZE, "%ld\n", udev->qfull_time_out <= 0 ?
2713                         udev->qfull_time_out :
2714                         udev->qfull_time_out / MSEC_PER_SEC);
2715 }
2716
2717 static ssize_t tcmu_qfull_time_out_store(struct config_item *item,
2718                                          const char *page, size_t count)
2719 {
2720         struct se_dev_attrib *da = container_of(to_config_group(item),
2721                                         struct se_dev_attrib, da_group);
2722         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2723         s32 val;
2724         int ret;
2725
2726         ret = kstrtos32(page, 0, &val);
2727         if (ret < 0)
2728                 return ret;
2729
2730         if (val >= 0) {
2731                 udev->qfull_time_out = val * MSEC_PER_SEC;
2732         } else if (val == -1) {
2733                 udev->qfull_time_out = val;
2734         } else {
2735                 printk(KERN_ERR "Invalid qfull timeout value %d\n", val);
2736                 return -EINVAL;
2737         }
2738         return count;
2739 }
2740 CONFIGFS_ATTR(tcmu_, qfull_time_out);
2741
2742 static ssize_t tcmu_max_data_area_mb_show(struct config_item *item, char *page)
2743 {
2744         struct se_dev_attrib *da = container_of(to_config_group(item),
2745                                                 struct se_dev_attrib, da_group);
2746         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2747
2748         return snprintf(page, PAGE_SIZE, "%u\n", udev->data_area_mb);
2749 }
2750 CONFIGFS_ATTR_RO(tcmu_, max_data_area_mb);
2751
2752 static ssize_t tcmu_data_pages_per_blk_show(struct config_item *item,
2753                                             char *page)
2754 {
2755         struct se_dev_attrib *da = container_of(to_config_group(item),
2756                                                 struct se_dev_attrib, da_group);
2757         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2758
2759         return snprintf(page, PAGE_SIZE, "%u\n", udev->data_pages_per_blk);
2760 }
2761 CONFIGFS_ATTR_RO(tcmu_, data_pages_per_blk);
2762
2763 static ssize_t tcmu_cmd_ring_size_mb_show(struct config_item *item, char *page)
2764 {
2765         struct se_dev_attrib *da = container_of(to_config_group(item),
2766                                                 struct se_dev_attrib, da_group);
2767         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2768
2769         return snprintf(page, PAGE_SIZE, "%u\n",
2770                         (udev->cmdr_size + CMDR_OFF) >> 20);
2771 }
2772 CONFIGFS_ATTR_RO(tcmu_, cmd_ring_size_mb);
2773
2774 static ssize_t tcmu_dev_config_show(struct config_item *item, char *page)
2775 {
2776         struct se_dev_attrib *da = container_of(to_config_group(item),
2777                                                 struct se_dev_attrib, da_group);
2778         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2779
2780         return snprintf(page, PAGE_SIZE, "%s\n", udev->dev_config);
2781 }
2782
2783 static int tcmu_send_dev_config_event(struct tcmu_dev *udev,
2784                                       const char *reconfig_data)
2785 {
2786         struct sk_buff *skb = NULL;
2787         void *msg_header = NULL;
2788         int ret = 0;
2789
2790         ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2791                                       &skb, &msg_header);
2792         if (ret < 0)
2793                 return ret;
2794         ret = nla_put_string(skb, TCMU_ATTR_DEV_CFG, reconfig_data);
2795         if (ret < 0) {
2796                 nlmsg_free(skb);
2797                 return ret;
2798         }
2799         return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2800                                        skb, msg_header);
2801 }
2802
2803
2804 static ssize_t tcmu_dev_config_store(struct config_item *item, const char *page,
2805                                      size_t count)
2806 {
2807         struct se_dev_attrib *da = container_of(to_config_group(item),
2808                                                 struct se_dev_attrib, da_group);
2809         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2810         int ret, len;
2811
2812         len = strlen(page);
2813         if (!len || len > TCMU_CONFIG_LEN - 1)
2814                 return -EINVAL;
2815
2816         /* Check if device has been configured before */
2817         if (target_dev_configured(&udev->se_dev)) {
2818                 ret = tcmu_send_dev_config_event(udev, page);
2819                 if (ret) {
2820                         pr_err("Unable to reconfigure device\n");
2821                         return ret;
2822                 }
2823                 strscpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2824
2825                 ret = tcmu_update_uio_info(udev);
2826                 if (ret)
2827                         return ret;
2828                 return count;
2829         }
2830         strscpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2831
2832         return count;
2833 }
2834 CONFIGFS_ATTR(tcmu_, dev_config);
2835
2836 static ssize_t tcmu_dev_size_show(struct config_item *item, char *page)
2837 {
2838         struct se_dev_attrib *da = container_of(to_config_group(item),
2839                                                 struct se_dev_attrib, da_group);
2840         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2841
2842         return snprintf(page, PAGE_SIZE, "%llu\n", udev->dev_size);
2843 }
2844
2845 static int tcmu_send_dev_size_event(struct tcmu_dev *udev, u64 size)
2846 {
2847         struct sk_buff *skb = NULL;
2848         void *msg_header = NULL;
2849         int ret = 0;
2850
2851         ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2852                                       &skb, &msg_header);
2853         if (ret < 0)
2854                 return ret;
2855         ret = nla_put_u64_64bit(skb, TCMU_ATTR_DEV_SIZE,
2856                                 size, TCMU_ATTR_PAD);
2857         if (ret < 0) {
2858                 nlmsg_free(skb);
2859                 return ret;
2860         }
2861         return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2862                                        skb, msg_header);
2863 }
2864
2865 static ssize_t tcmu_dev_size_store(struct config_item *item, const char *page,
2866                                    size_t count)
2867 {
2868         struct se_dev_attrib *da = container_of(to_config_group(item),
2869                                                 struct se_dev_attrib, da_group);
2870         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2871         u64 val;
2872         int ret;
2873
2874         ret = kstrtou64(page, 0, &val);
2875         if (ret < 0)
2876                 return ret;
2877
2878         /* Check if device has been configured before */
2879         if (target_dev_configured(&udev->se_dev)) {
2880                 ret = tcmu_send_dev_size_event(udev, val);
2881                 if (ret) {
2882                         pr_err("Unable to reconfigure device\n");
2883                         return ret;
2884                 }
2885         }
2886         udev->dev_size = val;
2887         return count;
2888 }
2889 CONFIGFS_ATTR(tcmu_, dev_size);
2890
2891 static ssize_t tcmu_nl_reply_supported_show(struct config_item *item,
2892                 char *page)
2893 {
2894         struct se_dev_attrib *da = container_of(to_config_group(item),
2895                                                 struct se_dev_attrib, da_group);
2896         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2897
2898         return snprintf(page, PAGE_SIZE, "%d\n", udev->nl_reply_supported);
2899 }
2900
2901 static ssize_t tcmu_nl_reply_supported_store(struct config_item *item,
2902                 const char *page, size_t count)
2903 {
2904         struct se_dev_attrib *da = container_of(to_config_group(item),
2905                                                 struct se_dev_attrib, da_group);
2906         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2907         s8 val;
2908         int ret;
2909
2910         ret = kstrtos8(page, 0, &val);
2911         if (ret < 0)
2912                 return ret;
2913
2914         udev->nl_reply_supported = val;
2915         return count;
2916 }
2917 CONFIGFS_ATTR(tcmu_, nl_reply_supported);
2918
2919 static ssize_t tcmu_emulate_write_cache_show(struct config_item *item,
2920                                              char *page)
2921 {
2922         struct se_dev_attrib *da = container_of(to_config_group(item),
2923                                         struct se_dev_attrib, da_group);
2924
2925         return snprintf(page, PAGE_SIZE, "%i\n", da->emulate_write_cache);
2926 }
2927
2928 static int tcmu_send_emulate_write_cache(struct tcmu_dev *udev, u8 val)
2929 {
2930         struct sk_buff *skb = NULL;
2931         void *msg_header = NULL;
2932         int ret = 0;
2933
2934         ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2935                                       &skb, &msg_header);
2936         if (ret < 0)
2937                 return ret;
2938         ret = nla_put_u8(skb, TCMU_ATTR_WRITECACHE, val);
2939         if (ret < 0) {
2940                 nlmsg_free(skb);
2941                 return ret;
2942         }
2943         return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2944                                        skb, msg_header);
2945 }
2946
2947 static ssize_t tcmu_emulate_write_cache_store(struct config_item *item,
2948                                               const char *page, size_t count)
2949 {
2950         struct se_dev_attrib *da = container_of(to_config_group(item),
2951                                         struct se_dev_attrib, da_group);
2952         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2953         u8 val;
2954         int ret;
2955
2956         ret = kstrtou8(page, 0, &val);
2957         if (ret < 0)
2958                 return ret;
2959
2960         /* Check if device has been configured before */
2961         if (target_dev_configured(&udev->se_dev)) {
2962                 ret = tcmu_send_emulate_write_cache(udev, val);
2963                 if (ret) {
2964                         pr_err("Unable to reconfigure device\n");
2965                         return ret;
2966                 }
2967         }
2968
2969         da->emulate_write_cache = val;
2970         return count;
2971 }
2972 CONFIGFS_ATTR(tcmu_, emulate_write_cache);
2973
2974 static ssize_t tcmu_tmr_notification_show(struct config_item *item, char *page)
2975 {
2976         struct se_dev_attrib *da = container_of(to_config_group(item),
2977                                         struct se_dev_attrib, da_group);
2978         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2979
2980         return snprintf(page, PAGE_SIZE, "%i\n",
2981                         test_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags));
2982 }
2983
2984 static ssize_t tcmu_tmr_notification_store(struct config_item *item,
2985                                            const char *page, size_t count)
2986 {
2987         struct se_dev_attrib *da = container_of(to_config_group(item),
2988                                         struct se_dev_attrib, da_group);
2989         struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2990         u8 val;
2991         int ret;
2992
2993         ret = kstrtou8(page, 0, &val);
2994         if (ret < 0)
2995                 return ret;
2996         if (val > 1)
2997                 return -EINVAL;
2998
2999         if (val)
3000                 set_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags);
3001         else
3002                 clear_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags);
3003         return count;
3004 }
3005 CONFIGFS_ATTR(tcmu_, tmr_notification);
3006
3007 static ssize_t tcmu_block_dev_show(struct config_item *item, char *page)
3008 {
3009         struct se_device *se_dev = container_of(to_config_group(item),
3010                                                 struct se_device,
3011                                                 dev_action_group);
3012         struct tcmu_dev *udev = TCMU_DEV(se_dev);
3013
3014         if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
3015                 return snprintf(page, PAGE_SIZE, "%s\n", "blocked");
3016         else
3017                 return snprintf(page, PAGE_SIZE, "%s\n", "unblocked");
3018 }
3019
3020 static ssize_t tcmu_block_dev_store(struct config_item *item, const char *page,
3021                                     size_t count)
3022 {
3023         struct se_device *se_dev = container_of(to_config_group(item),
3024                                                 struct se_device,
3025                                                 dev_action_group);
3026         struct tcmu_dev *udev = TCMU_DEV(se_dev);
3027         u8 val;
3028         int ret;
3029
3030         if (!target_dev_configured(&udev->se_dev)) {
3031                 pr_err("Device is not configured.\n");
3032                 return -EINVAL;
3033         }
3034
3035         ret = kstrtou8(page, 0, &val);
3036         if (ret < 0)
3037                 return ret;
3038
3039         if (val > 1) {
3040                 pr_err("Invalid block value %d\n", val);
3041                 return -EINVAL;
3042         }
3043
3044         if (!val)
3045                 tcmu_unblock_dev(udev);
3046         else
3047                 tcmu_block_dev(udev);
3048         return count;
3049 }
3050 CONFIGFS_ATTR(tcmu_, block_dev);
3051
3052 static ssize_t tcmu_reset_ring_store(struct config_item *item, const char *page,
3053                                      size_t count)
3054 {
3055         struct se_device *se_dev = container_of(to_config_group(item),
3056                                                 struct se_device,
3057                                                 dev_action_group);
3058         struct tcmu_dev *udev = TCMU_DEV(se_dev);
3059         u8 val;
3060         int ret;
3061
3062         if (!target_dev_configured(&udev->se_dev)) {
3063                 pr_err("Device is not configured.\n");
3064                 return -EINVAL;
3065         }
3066
3067         ret = kstrtou8(page, 0, &val);
3068         if (ret < 0)
3069                 return ret;
3070
3071         if (val != 1 && val != 2) {
3072                 pr_err("Invalid reset ring value %d\n", val);
3073                 return -EINVAL;
3074         }
3075
3076         tcmu_reset_ring(udev, val);
3077         return count;
3078 }
3079 CONFIGFS_ATTR_WO(tcmu_, reset_ring);
3080
3081 static ssize_t tcmu_free_kept_buf_store(struct config_item *item, const char *page,
3082                                         size_t count)
3083 {
3084         struct se_device *se_dev = container_of(to_config_group(item),
3085                                                 struct se_device,
3086                                                 dev_action_group);
3087         struct tcmu_dev *udev = TCMU_DEV(se_dev);
3088         struct tcmu_cmd *cmd;
3089         u16 cmd_id;
3090         int ret;
3091
3092         if (!target_dev_configured(&udev->se_dev)) {
3093                 pr_err("Device is not configured.\n");
3094                 return -EINVAL;
3095         }
3096
3097         ret = kstrtou16(page, 0, &cmd_id);
3098         if (ret < 0)
3099                 return ret;
3100
3101         mutex_lock(&udev->cmdr_lock);
3102
3103         {
3104                 XA_STATE(xas, &udev->commands, cmd_id);
3105
3106                 xas_lock(&xas);
3107                 cmd = xas_load(&xas);
3108                 if (!cmd) {
3109                         pr_err("free_kept_buf: cmd_id %d not found\n", cmd_id);
3110                         count = -EINVAL;
3111                         xas_unlock(&xas);
3112                         goto out_unlock;
3113                 }
3114                 if (!test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags)) {
3115                         pr_err("free_kept_buf: cmd_id %d was not completed with KEEP_BUF\n",
3116                                cmd_id);
3117                         count = -EINVAL;
3118                         xas_unlock(&xas);
3119                         goto out_unlock;
3120                 }
3121                 xas_store(&xas, NULL);
3122                 xas_unlock(&xas);
3123         }
3124
3125         tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
3126         tcmu_free_cmd(cmd);
3127         /*
3128          * We only freed data space, not ring space. Therefore we dont call
3129          * run_tmr_queue, but call run_qfull_queue if tmr_list is empty.
3130          */
3131         if (list_empty(&udev->tmr_queue))
3132                 run_qfull_queue(udev, false);
3133
3134 out_unlock:
3135         mutex_unlock(&udev->cmdr_lock);
3136         return count;
3137 }
3138 CONFIGFS_ATTR_WO(tcmu_, free_kept_buf);
3139
3140 static struct configfs_attribute *tcmu_attrib_attrs[] = {
3141         &tcmu_attr_cmd_time_out,
3142         &tcmu_attr_qfull_time_out,
3143         &tcmu_attr_max_data_area_mb,
3144         &tcmu_attr_data_pages_per_blk,
3145         &tcmu_attr_cmd_ring_size_mb,
3146         &tcmu_attr_dev_config,
3147         &tcmu_attr_dev_size,
3148         &tcmu_attr_emulate_write_cache,
3149         &tcmu_attr_tmr_notification,
3150         &tcmu_attr_nl_reply_supported,
3151         NULL,
3152 };
3153
3154 static struct configfs_attribute **tcmu_attrs;
3155
3156 static struct configfs_attribute *tcmu_action_attrs[] = {
3157         &tcmu_attr_block_dev,
3158         &tcmu_attr_reset_ring,
3159         &tcmu_attr_free_kept_buf,
3160         NULL,
3161 };
3162
3163 static struct target_backend_ops tcmu_ops = {
3164         .name                   = "user",
3165         .owner                  = THIS_MODULE,
3166         .transport_flags_default = TRANSPORT_FLAG_PASSTHROUGH,
3167         .transport_flags_changeable = TRANSPORT_FLAG_PASSTHROUGH_PGR |
3168                                       TRANSPORT_FLAG_PASSTHROUGH_ALUA,
3169         .attach_hba             = tcmu_attach_hba,
3170         .detach_hba             = tcmu_detach_hba,
3171         .alloc_device           = tcmu_alloc_device,
3172         .configure_device       = tcmu_configure_device,
3173         .destroy_device         = tcmu_destroy_device,
3174         .free_device            = tcmu_free_device,
3175         .unplug_device          = tcmu_unplug_device,
3176         .plug_device            = tcmu_plug_device,
3177         .parse_cdb              = tcmu_parse_cdb,
3178         .tmr_notify             = tcmu_tmr_notify,
3179         .set_configfs_dev_params = tcmu_set_configfs_dev_params,
3180         .show_configfs_dev_params = tcmu_show_configfs_dev_params,
3181         .get_device_type        = sbc_get_device_type,
3182         .get_blocks             = tcmu_get_blocks,
3183         .tb_dev_action_attrs    = tcmu_action_attrs,
3184 };
3185
3186 static void find_free_blocks(void)
3187 {
3188         struct tcmu_dev *udev;
3189         loff_t off;
3190         u32 pages_freed, total_pages_freed = 0;
3191         u32 start, end, block, total_blocks_freed = 0;
3192
3193         if (atomic_read(&global_page_count) <= tcmu_global_max_pages)
3194                 return;
3195
3196         mutex_lock(&root_udev_mutex);
3197         list_for_each_entry(udev, &root_udev, node) {
3198                 mutex_lock(&udev->cmdr_lock);
3199
3200                 if (!target_dev_configured(&udev->se_dev)) {
3201                         mutex_unlock(&udev->cmdr_lock);
3202                         continue;
3203                 }
3204
3205                 /* Try to complete the finished commands first */
3206                 if (tcmu_handle_completions(udev))
3207                         run_qfull_queue(udev, false);
3208
3209                 /* Skip the udevs in idle */
3210                 if (!udev->dbi_thresh) {
3211                         mutex_unlock(&udev->cmdr_lock);
3212                         continue;
3213                 }
3214
3215                 end = udev->dbi_max + 1;
3216                 block = find_last_bit(udev->data_bitmap, end);
3217                 if (block == udev->dbi_max) {
3218                         /*
3219                          * The last bit is dbi_max, so it is not possible
3220                          * reclaim any blocks.
3221                          */
3222                         mutex_unlock(&udev->cmdr_lock);
3223                         continue;
3224                 } else if (block == end) {
3225                         /* The current udev will goto idle state */
3226                         udev->dbi_thresh = start = 0;
3227                         udev->dbi_max = 0;
3228                 } else {
3229                         udev->dbi_thresh = start = block + 1;
3230                         udev->dbi_max = block;
3231                 }
3232
3233                 /*
3234                  * Release the block pages.
3235                  *
3236                  * Also note that since tcmu_vma_fault() gets an extra page
3237                  * refcount, tcmu_blocks_release() won't free pages if pages
3238                  * are mapped. This means it is safe to call
3239                  * tcmu_blocks_release() before unmap_mapping_range() which
3240                  * drops the refcount of any pages it unmaps and thus releases
3241                  * them.
3242                  */
3243                 pages_freed = tcmu_blocks_release(udev, start, end - 1);
3244
3245                 /* Here will truncate the data area from off */
3246                 off = udev->data_off + (loff_t)start * udev->data_blk_size;
3247                 unmap_mapping_range(udev->inode->i_mapping, off, 0, 1);
3248
3249                 mutex_unlock(&udev->cmdr_lock);
3250
3251                 total_pages_freed += pages_freed;
3252                 total_blocks_freed += end - start;
3253                 pr_debug("Freed %u pages (total %u) from %u blocks (total %u) from %s.\n",
3254                          pages_freed, total_pages_freed, end - start,
3255                          total_blocks_freed, udev->name);
3256         }
3257         mutex_unlock(&root_udev_mutex);
3258
3259         if (atomic_read(&global_page_count) > tcmu_global_max_pages)
3260                 schedule_delayed_work(&tcmu_unmap_work, msecs_to_jiffies(5000));
3261 }
3262
3263 static void check_timedout_devices(void)
3264 {
3265         struct tcmu_dev *udev, *tmp_dev;
3266         struct tcmu_cmd *cmd, *tmp_cmd;
3267         LIST_HEAD(devs);
3268
3269         spin_lock_bh(&timed_out_udevs_lock);
3270         list_splice_init(&timed_out_udevs, &devs);
3271
3272         list_for_each_entry_safe(udev, tmp_dev, &devs, timedout_entry) {
3273                 list_del_init(&udev->timedout_entry);
3274                 spin_unlock_bh(&timed_out_udevs_lock);
3275
3276                 mutex_lock(&udev->cmdr_lock);
3277
3278                 /*
3279                  * If cmd_time_out is disabled but qfull is set deadline
3280                  * will only reflect the qfull timeout. Ignore it.
3281                  */
3282                 if (udev->cmd_time_out) {
3283                         list_for_each_entry_safe(cmd, tmp_cmd,
3284                                                  &udev->inflight_queue,
3285                                                  queue_entry) {
3286                                 tcmu_check_expired_ring_cmd(cmd);
3287                         }
3288                         tcmu_set_next_deadline(&udev->inflight_queue,
3289                                                &udev->cmd_timer);
3290                 }
3291                 list_for_each_entry_safe(cmd, tmp_cmd, &udev->qfull_queue,
3292                                          queue_entry) {
3293                         tcmu_check_expired_queue_cmd(cmd);
3294                 }
3295                 tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
3296
3297                 mutex_unlock(&udev->cmdr_lock);
3298
3299                 spin_lock_bh(&timed_out_udevs_lock);
3300         }
3301
3302         spin_unlock_bh(&timed_out_udevs_lock);
3303 }
3304
3305 static void tcmu_unmap_work_fn(struct work_struct *work)
3306 {
3307         check_timedout_devices();
3308         find_free_blocks();
3309 }
3310
3311 static int __init tcmu_module_init(void)
3312 {
3313         int ret, i, k, len = 0;
3314
3315         BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry) % TCMU_OP_ALIGN_SIZE) != 0);
3316
3317         INIT_DELAYED_WORK(&tcmu_unmap_work, tcmu_unmap_work_fn);
3318
3319         tcmu_cmd_cache = kmem_cache_create("tcmu_cmd_cache",
3320                                 sizeof(struct tcmu_cmd),
3321                                 __alignof__(struct tcmu_cmd),
3322                                 0, NULL);
3323         if (!tcmu_cmd_cache)
3324                 return -ENOMEM;
3325
3326         tcmu_root_device = root_device_register("tcm_user");
3327         if (IS_ERR(tcmu_root_device)) {
3328                 ret = PTR_ERR(tcmu_root_device);
3329                 goto out_free_cache;
3330         }
3331
3332         ret = genl_register_family(&tcmu_genl_family);
3333         if (ret < 0) {
3334                 goto out_unreg_device;
3335         }
3336
3337         for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
3338                 len += sizeof(struct configfs_attribute *);
3339         for (i = 0; passthrough_pr_attrib_attrs[i] != NULL; i++)
3340                 len += sizeof(struct configfs_attribute *);
3341         for (i = 0; tcmu_attrib_attrs[i] != NULL; i++)
3342                 len += sizeof(struct configfs_attribute *);
3343         len += sizeof(struct configfs_attribute *);
3344
3345         tcmu_attrs = kzalloc(len, GFP_KERNEL);
3346         if (!tcmu_attrs) {
3347                 ret = -ENOMEM;
3348                 goto out_unreg_genl;
3349         }
3350
3351         for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
3352                 tcmu_attrs[i] = passthrough_attrib_attrs[i];
3353         for (k = 0; passthrough_pr_attrib_attrs[k] != NULL; k++)
3354                 tcmu_attrs[i++] = passthrough_pr_attrib_attrs[k];
3355         for (k = 0; tcmu_attrib_attrs[k] != NULL; k++)
3356                 tcmu_attrs[i++] = tcmu_attrib_attrs[k];
3357         tcmu_ops.tb_dev_attrib_attrs = tcmu_attrs;
3358
3359         ret = transport_backend_register(&tcmu_ops);
3360         if (ret)
3361                 goto out_attrs;
3362
3363         return 0;
3364
3365 out_attrs:
3366         kfree(tcmu_attrs);
3367 out_unreg_genl:
3368         genl_unregister_family(&tcmu_genl_family);
3369 out_unreg_device:
3370         root_device_unregister(tcmu_root_device);
3371 out_free_cache:
3372         kmem_cache_destroy(tcmu_cmd_cache);
3373
3374         return ret;
3375 }
3376
3377 static void __exit tcmu_module_exit(void)
3378 {
3379         cancel_delayed_work_sync(&tcmu_unmap_work);
3380         target_backend_unregister(&tcmu_ops);
3381         kfree(tcmu_attrs);
3382         genl_unregister_family(&tcmu_genl_family);
3383         root_device_unregister(tcmu_root_device);
3384         kmem_cache_destroy(tcmu_cmd_cache);
3385 }
3386
3387 MODULE_DESCRIPTION("TCM USER subsystem plugin");
3388 MODULE_AUTHOR("Shaohua Li <shli@kernel.org>");
3389 MODULE_AUTHOR("Andy Grover <agrover@redhat.com>");
3390 MODULE_LICENSE("GPL");
3391
3392 module_init(tcmu_module_init);
3393 module_exit(tcmu_module_exit);