linux/drivers/target/target_core_user.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) 2013 Shaohua Li <shli@kernel.org>
   4 * Copyright (C) 2014 Red Hat, Inc.
   5 * Copyright (C) 2015 Arrikto, Inc.
   6 * Copyright (C) 2017 Chinamobile, Inc.
   7 */
   8
   9#include <linux/spinlock.h>
  10#include <linux/module.h>
  11#include <linux/kernel.h>
  12#include <linux/timer.h>
  13#include <linux/parser.h>
  14#include <linux/vmalloc.h>
  15#include <linux/uio_driver.h>
  16#include <linux/xarray.h>
  17#include <linux/stringify.h>
  18#include <linux/bitops.h>
  19#include <linux/highmem.h>
  20#include <linux/configfs.h>
  21#include <linux/mutex.h>
  22#include <linux/workqueue.h>
  23#include <net/genetlink.h>
  24#include <scsi/scsi_common.h>
  25#include <scsi/scsi_proto.h>
  26#include <target/target_core_base.h>
  27#include <target/target_core_fabric.h>
  28#include <target/target_core_backend.h>
  29
  30#include <linux/target_core_user.h>
  31
  32/**
  33 * DOC: Userspace I/O
  34 * Userspace I/O
  35 * -------------
  36 *
  37 * Define a shared-memory interface for LIO to pass SCSI commands and
  38 * data to userspace for processing. This is to allow backends that
  39 * are too complex for in-kernel support to be possible.
  40 *
  41 * It uses the UIO framework to do a lot of the device-creation and
  42 * introspection work for us.
  43 *
  44 * See the .h file for how the ring is laid out. Note that while the
  45 * command ring is defined, the particulars of the data area are
  46 * not. Offset values in the command entry point to other locations
  47 * internal to the mmap-ed area. There is separate space outside the
  48 * command ring for data buffers. This leaves maximum flexibility for
  49 * moving buffer allocations, or even page flipping or other
  50 * allocation techniques, without altering the command ring layout.
  51 *
  52 * SECURITY:
  53 * The user process must be assumed to be malicious. There's no way to
  54 * prevent it breaking the command ring protocol if it wants, but in
  55 * order to prevent other issues we must only ever read *data* from
  56 * the shared memory area, not offsets or sizes. This applies to
  57 * command ring entries as well as the mailbox. Extra code needed for
  58 * this may have a 'UAM' comment.
  59 */
  60
  61#define TCMU_TIME_OUT (30 * MSEC_PER_SEC)
  62
  63/* For mailbox plus cmd ring, the size is fixed 8MB */
  64#define MB_CMDR_SIZE (8 * 1024 * 1024)
  65/* Offset of cmd ring is size of mailbox */
  66#define CMDR_OFF sizeof(struct tcmu_mailbox)
  67#define CMDR_SIZE (MB_CMDR_SIZE - CMDR_OFF)
  68
  69/*
  70 * For data area, the default block size is PAGE_SIZE and
  71 * the default total size is 256K * PAGE_SIZE.
  72 */
  73#define DATA_PAGES_PER_BLK_DEF 1
  74#define DATA_AREA_PAGES_DEF (256 * 1024)
  75
  76#define TCMU_MBS_TO_PAGES(_mbs) ((size_t)_mbs << (20 - PAGE_SHIFT))
  77#define TCMU_PAGES_TO_MBS(_pages) (_pages >> (20 - PAGE_SHIFT))
  78
  79/*
  80 * Default number of global data blocks(512K * PAGE_SIZE)
  81 * when the unmap thread will be started.
  82 */
  83#define TCMU_GLOBAL_MAX_PAGES_DEF (512 * 1024)
  84
  85static u8 tcmu_kern_cmd_reply_supported;
  86static u8 tcmu_netlink_blocked;
  87
  88static struct device *tcmu_root_device;
  89
  90struct tcmu_hba {
  91        u32 host_id;
  92};
  93
  94#define TCMU_CONFIG_LEN 256
  95
  96static DEFINE_MUTEX(tcmu_nl_cmd_mutex);
  97static LIST_HEAD(tcmu_nl_cmd_list);
  98
  99struct tcmu_dev;
 100
 101struct tcmu_nl_cmd {
 102        /* wake up thread waiting for reply */
 103        struct completion complete;
 104        struct list_head nl_list;
 105        struct tcmu_dev *udev;
 106        int cmd;
 107        int status;
 108};
 109
 110struct tcmu_dev {
 111        struct list_head node;
 112        struct kref kref;
 113
 114        struct se_device se_dev;
 115        struct se_dev_plug se_plug;
 116
 117        char *name;
 118        struct se_hba *hba;
 119
 120#define TCMU_DEV_BIT_OPEN 0
 121#define TCMU_DEV_BIT_BROKEN 1
 122#define TCMU_DEV_BIT_BLOCKED 2
 123#define TCMU_DEV_BIT_TMR_NOTIFY 3
 124#define TCM_DEV_BIT_PLUGGED 4
 125        unsigned long flags;
 126
 127        struct uio_info uio_info;
 128
 129        struct inode *inode;
 130
 131        uint64_t dev_size;
 132
 133        struct tcmu_mailbox *mb_addr;
 134        void *cmdr;
 135        u32 cmdr_size;
 136        u32 cmdr_last_cleaned;
 137        /* Offset of data area from start of mb */
 138        /* Must add data_off and mb_addr to get the address */
 139        size_t data_off;
 140        int data_area_mb;
 141        uint32_t max_blocks;
 142        size_t mmap_pages;
 143
 144        struct mutex cmdr_lock;
 145        struct list_head qfull_queue;
 146        struct list_head tmr_queue;
 147
 148        uint32_t dbi_max;
 149        uint32_t dbi_thresh;
 150        unsigned long *data_bitmap;
 151        struct xarray data_pages;
 152        uint32_t data_pages_per_blk;
 153        uint32_t data_blk_size;
 154
 155        struct xarray commands;
 156
 157        struct timer_list cmd_timer;
 158        unsigned int cmd_time_out;
 159        struct list_head inflight_queue;
 160
 161        struct timer_list qfull_timer;
 162        int qfull_time_out;
 163
 164        struct list_head timedout_entry;
 165
 166        struct tcmu_nl_cmd curr_nl_cmd;
 167
 168        char dev_config[TCMU_CONFIG_LEN];
 169
 170        int nl_reply_supported;
 171};
 172
 173#define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev)
 174
 175struct tcmu_cmd {
 176        struct se_cmd *se_cmd;
 177        struct tcmu_dev *tcmu_dev;
 178        struct list_head queue_entry;
 179
 180        uint16_t cmd_id;
 181
 182        /* Can't use se_cmd when cleaning up expired cmds, because if
 183           cmd has been completed then accessing se_cmd is off limits */
 184        uint32_t dbi_cnt;
 185        uint32_t dbi_bidi_cnt;
 186        uint32_t dbi_cur;
 187        uint32_t *dbi;
 188
 189        uint32_t data_len_bidi;
 190
 191        unsigned long deadline;
 192
 193#define TCMU_CMD_BIT_EXPIRED 0
 194        unsigned long flags;
 195};
 196
 197struct tcmu_tmr {
 198        struct list_head queue_entry;
 199
 200        uint8_t tmr_type;
 201        uint32_t tmr_cmd_cnt;
 202        int16_t tmr_cmd_ids[];
 203};
 204
 205/*
 206 * To avoid dead lock the mutex lock order should always be:
 207 *
 208 * mutex_lock(&root_udev_mutex);
 209 * ...
 210 * mutex_lock(&tcmu_dev->cmdr_lock);
 211 * mutex_unlock(&tcmu_dev->cmdr_lock);
 212 * ...
 213 * mutex_unlock(&root_udev_mutex);
 214 */
 215static DEFINE_MUTEX(root_udev_mutex);
 216static LIST_HEAD(root_udev);
 217
 218static DEFINE_SPINLOCK(timed_out_udevs_lock);
 219static LIST_HEAD(timed_out_udevs);
 220
 221static struct kmem_cache *tcmu_cmd_cache;
 222
 223static atomic_t global_page_count = ATOMIC_INIT(0);
 224static struct delayed_work tcmu_unmap_work;
 225static int tcmu_global_max_pages = TCMU_GLOBAL_MAX_PAGES_DEF;
 226
 227static int tcmu_set_global_max_data_area(const char *str,
 228                                         const struct kernel_param *kp)
 229{
 230        int ret, max_area_mb;
 231
 232        ret = kstrtoint(str, 10, &max_area_mb);
 233        if (ret)
 234                return -EINVAL;
 235
 236        if (max_area_mb <= 0) {
 237                pr_err("global_max_data_area must be larger than 0.\n");
 238                return -EINVAL;
 239        }
 240
 241        tcmu_global_max_pages = TCMU_MBS_TO_PAGES(max_area_mb);
 242        if (atomic_read(&global_page_count) > tcmu_global_max_pages)
 243                schedule_delayed_work(&tcmu_unmap_work, 0);
 244        else
 245                cancel_delayed_work_sync(&tcmu_unmap_work);
 246
 247        return 0;
 248}
 249
 250static int tcmu_get_global_max_data_area(char *buffer,
 251                                         const struct kernel_param *kp)
 252{
 253        return sprintf(buffer, "%d\n", TCMU_PAGES_TO_MBS(tcmu_global_max_pages));
 254}
 255
 256static const struct kernel_param_ops tcmu_global_max_data_area_op = {
 257        .set = tcmu_set_global_max_data_area,
 258        .get = tcmu_get_global_max_data_area,
 259};
 260
 261module_param_cb(global_max_data_area_mb, &tcmu_global_max_data_area_op, NULL,
 262                S_IWUSR | S_IRUGO);
 263MODULE_PARM_DESC(global_max_data_area_mb,
 264                 "Max MBs allowed to be allocated to all the tcmu device's "
 265                 "data areas.");
 266
 267static int tcmu_get_block_netlink(char *buffer,
 268                                  const struct kernel_param *kp)
 269{
 270        return sprintf(buffer, "%s\n", tcmu_netlink_blocked ?
 271                       "blocked" : "unblocked");
 272}
 273
 274static int tcmu_set_block_netlink(const char *str,
 275                                  const struct kernel_param *kp)
 276{
 277        int ret;
 278        u8 val;
 279
 280        ret = kstrtou8(str, 0, &val);
 281        if (ret < 0)
 282                return ret;
 283
 284        if (val > 1) {
 285                pr_err("Invalid block netlink value %u\n", val);
 286                return -EINVAL;
 287        }
 288
 289        tcmu_netlink_blocked = val;
 290        return 0;
 291}
 292
 293static const struct kernel_param_ops tcmu_block_netlink_op = {
 294        .set = tcmu_set_block_netlink,
 295        .get = tcmu_get_block_netlink,
 296};
 297
 298module_param_cb(block_netlink, &tcmu_block_netlink_op, NULL, S_IWUSR | S_IRUGO);
 299MODULE_PARM_DESC(block_netlink, "Block new netlink commands.");
 300
 301static int tcmu_fail_netlink_cmd(struct tcmu_nl_cmd *nl_cmd)
 302{
 303        struct tcmu_dev *udev = nl_cmd->udev;
 304
 305        if (!tcmu_netlink_blocked) {
 306                pr_err("Could not reset device's netlink interface. Netlink is not blocked.\n");
 307                return -EBUSY;
 308        }
 309
 310        if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
 311                pr_debug("Aborting nl cmd %d on %s\n", nl_cmd->cmd, udev->name);
 312                nl_cmd->status = -EINTR;
 313                list_del(&nl_cmd->nl_list);
 314                complete(&nl_cmd->complete);
 315        }
 316        return 0;
 317}
 318
 319static int tcmu_set_reset_netlink(const char *str,
 320                                  const struct kernel_param *kp)
 321{
 322        struct tcmu_nl_cmd *nl_cmd, *tmp_cmd;
 323        int ret;
 324        u8 val;
 325
 326        ret = kstrtou8(str, 0, &val);
 327        if (ret < 0)
 328                return ret;
 329
 330        if (val != 1) {
 331                pr_err("Invalid reset netlink value %u\n", val);
 332                return -EINVAL;
 333        }
 334
 335        mutex_lock(&tcmu_nl_cmd_mutex);
 336        list_for_each_entry_safe(nl_cmd, tmp_cmd, &tcmu_nl_cmd_list, nl_list) {
 337                ret = tcmu_fail_netlink_cmd(nl_cmd);
 338                if (ret)
 339                        break;
 340        }
 341        mutex_unlock(&tcmu_nl_cmd_mutex);
 342
 343        return ret;
 344}
 345
 346static const struct kernel_param_ops tcmu_reset_netlink_op = {
 347        .set = tcmu_set_reset_netlink,
 348};
 349
 350module_param_cb(reset_netlink, &tcmu_reset_netlink_op, NULL, S_IWUSR);
 351MODULE_PARM_DESC(reset_netlink, "Reset netlink commands.");
 352
 353/* multicast group */
 354enum tcmu_multicast_groups {
 355        TCMU_MCGRP_CONFIG,
 356};
 357
 358static const struct genl_multicast_group tcmu_mcgrps[] = {
 359        [TCMU_MCGRP_CONFIG] = { .name = "config", },
 360};
 361
 362static struct nla_policy tcmu_attr_policy[TCMU_ATTR_MAX+1] = {
 363        [TCMU_ATTR_DEVICE]      = { .type = NLA_STRING },
 364        [TCMU_ATTR_MINOR]       = { .type = NLA_U32 },
 365        [TCMU_ATTR_CMD_STATUS]  = { .type = NLA_S32 },
 366        [TCMU_ATTR_DEVICE_ID]   = { .type = NLA_U32 },
 367        [TCMU_ATTR_SUPP_KERN_CMD_REPLY] = { .type = NLA_U8 },
 368};
 369
 370static int tcmu_genl_cmd_done(struct genl_info *info, int completed_cmd)
 371{
 372        struct tcmu_dev *udev = NULL;
 373        struct tcmu_nl_cmd *nl_cmd;
 374        int dev_id, rc, ret = 0;
 375
 376        if (!info->attrs[TCMU_ATTR_CMD_STATUS] ||
 377            !info->attrs[TCMU_ATTR_DEVICE_ID]) {
 378                printk(KERN_ERR "TCMU_ATTR_CMD_STATUS or TCMU_ATTR_DEVICE_ID not set, doing nothing\n");
 379                return -EINVAL;
 380        }
 381
 382        dev_id = nla_get_u32(info->attrs[TCMU_ATTR_DEVICE_ID]);
 383        rc = nla_get_s32(info->attrs[TCMU_ATTR_CMD_STATUS]);
 384
 385        mutex_lock(&tcmu_nl_cmd_mutex);
 386        list_for_each_entry(nl_cmd, &tcmu_nl_cmd_list, nl_list) {
 387                if (nl_cmd->udev->se_dev.dev_index == dev_id) {
 388                        udev = nl_cmd->udev;
 389                        break;
 390                }
 391        }
 392
 393        if (!udev) {
 394                pr_err("tcmu nl cmd %u/%d completion could not find device with dev id %u.\n",
 395                       completed_cmd, rc, dev_id);
 396                ret = -ENODEV;
 397                goto unlock;
 398        }
 399        list_del(&nl_cmd->nl_list);
 400
 401        pr_debug("%s genl cmd done got id %d curr %d done %d rc %d stat %d\n",
 402                 udev->name, dev_id, nl_cmd->cmd, completed_cmd, rc,
 403                 nl_cmd->status);
 404
 405        if (nl_cmd->cmd != completed_cmd) {
 406                pr_err("Mismatched commands on %s (Expecting reply for %d. Current %d).\n",
 407                       udev->name, completed_cmd, nl_cmd->cmd);
 408                ret = -EINVAL;
 409                goto unlock;
 410        }
 411
 412        nl_cmd->status = rc;
 413        complete(&nl_cmd->complete);
 414unlock:
 415        mutex_unlock(&tcmu_nl_cmd_mutex);
 416        return ret;
 417}
 418
 419static int tcmu_genl_rm_dev_done(struct sk_buff *skb, struct genl_info *info)
 420{
 421        return tcmu_genl_cmd_done(info, TCMU_CMD_REMOVED_DEVICE);
 422}
 423
 424static int tcmu_genl_add_dev_done(struct sk_buff *skb, struct genl_info *info)
 425{
 426        return tcmu_genl_cmd_done(info, TCMU_CMD_ADDED_DEVICE);
 427}
 428
 429static int tcmu_genl_reconfig_dev_done(struct sk_buff *skb,
 430                                       struct genl_info *info)
 431{
 432        return tcmu_genl_cmd_done(info, TCMU_CMD_RECONFIG_DEVICE);
 433}
 434
 435static int tcmu_genl_set_features(struct sk_buff *skb, struct genl_info *info)
 436{
 437        if (info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]) {
 438                tcmu_kern_cmd_reply_supported  =
 439                        nla_get_u8(info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]);
 440                printk(KERN_INFO "tcmu daemon: command reply support %u.\n",
 441                       tcmu_kern_cmd_reply_supported);
 442        }
 443
 444        return 0;
 445}
 446
 447static const struct genl_small_ops tcmu_genl_ops[] = {
 448        {
 449                .cmd    = TCMU_CMD_SET_FEATURES,
 450                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 451                .flags  = GENL_ADMIN_PERM,
 452                .doit   = tcmu_genl_set_features,
 453        },
 454        {
 455                .cmd    = TCMU_CMD_ADDED_DEVICE_DONE,
 456                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 457                .flags  = GENL_ADMIN_PERM,
 458                .doit   = tcmu_genl_add_dev_done,
 459        },
 460        {
 461                .cmd    = TCMU_CMD_REMOVED_DEVICE_DONE,
 462                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 463                .flags  = GENL_ADMIN_PERM,
 464                .doit   = tcmu_genl_rm_dev_done,
 465        },
 466        {
 467                .cmd    = TCMU_CMD_RECONFIG_DEVICE_DONE,
 468                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 469                .flags  = GENL_ADMIN_PERM,
 470                .doit   = tcmu_genl_reconfig_dev_done,
 471        },
 472};
 473
 474/* Our generic netlink family */
 475static struct genl_family tcmu_genl_family __ro_after_init = {
 476        .module = THIS_MODULE,
 477        .hdrsize = 0,
 478        .name = "TCM-USER",
 479        .version = 2,
 480        .maxattr = TCMU_ATTR_MAX,
 481        .policy = tcmu_attr_policy,
 482        .mcgrps = tcmu_mcgrps,
 483        .n_mcgrps = ARRAY_SIZE(tcmu_mcgrps),
 484        .netnsok = true,
 485        .small_ops = tcmu_genl_ops,
 486        .n_small_ops = ARRAY_SIZE(tcmu_genl_ops),
 487};
 488
 489#define tcmu_cmd_set_dbi_cur(cmd, index) ((cmd)->dbi_cur = (index))
 490#define tcmu_cmd_reset_dbi_cur(cmd) tcmu_cmd_set_dbi_cur(cmd, 0)
 491#define tcmu_cmd_set_dbi(cmd, index) ((cmd)->dbi[(cmd)->dbi_cur++] = (index))
 492#define tcmu_cmd_get_dbi(cmd) ((cmd)->dbi[(cmd)->dbi_cur++])
 493
 494static void tcmu_cmd_free_data(struct tcmu_cmd *tcmu_cmd, uint32_t len)
 495{
 496        struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
 497        uint32_t i;
 498
 499        for (i = 0; i < len; i++)
 500                clear_bit(tcmu_cmd->dbi[i], udev->data_bitmap);
 501}
 502
 503static inline int tcmu_get_empty_block(struct tcmu_dev *udev,
 504                                       struct tcmu_cmd *tcmu_cmd,
 505                                       int prev_dbi, int length, int *iov_cnt)
 506{
 507        XA_STATE(xas, &udev->data_pages, 0);
 508        struct page *page;
 509        int i, cnt, dbi, dpi;
 510        int page_cnt = DIV_ROUND_UP(length, PAGE_SIZE);
 511
 512        dbi = find_first_zero_bit(udev->data_bitmap, udev->dbi_thresh);
 513        if (dbi == udev->dbi_thresh)
 514                return -1;
 515
 516        dpi = dbi * udev->data_pages_per_blk;
 517        /* Count the number of already allocated pages */
 518        xas_set(&xas, dpi);
 519        rcu_read_lock();
 520        for (cnt = 0; xas_next(&xas) && cnt < page_cnt;)
 521                cnt++;
 522        rcu_read_unlock();
 523
 524        for (i = cnt; i < page_cnt; i++) {
 525                /* try to get new page from the mm */
 526                page = alloc_page(GFP_NOIO);
 527                if (!page)
 528                        break;
 529
 530                if (xa_store(&udev->data_pages, dpi + i, page, GFP_NOIO)) {
 531                        __free_page(page);
 532                        break;
 533                }
 534        }
 535        if (atomic_add_return(i - cnt, &global_page_count) >
 536                              tcmu_global_max_pages)
 537                schedule_delayed_work(&tcmu_unmap_work, 0);
 538
 539        if (i && dbi > udev->dbi_max)
 540                udev->dbi_max = dbi;
 541
 542        set_bit(dbi, udev->data_bitmap);
 543        tcmu_cmd_set_dbi(tcmu_cmd, dbi);
 544
 545        if (dbi != prev_dbi + 1)
 546                *iov_cnt += 1;
 547
 548        return i == page_cnt ? dbi : -1;
 549}
 550
 551static int tcmu_get_empty_blocks(struct tcmu_dev *udev,
 552                                 struct tcmu_cmd *tcmu_cmd, int length)
 553{
 554        /* start value of dbi + 1 must not be a valid dbi */
 555        int dbi = -2;
 556        int blk_data_len, iov_cnt = 0;
 557        uint32_t blk_size = udev->data_blk_size;
 558
 559        for (; length > 0; length -= blk_size) {
 560                blk_data_len = min_t(uint32_t, length, blk_size);
 561                dbi = tcmu_get_empty_block(udev, tcmu_cmd, dbi, blk_data_len,
 562                                           &iov_cnt);
 563                if (dbi < 0)
 564                        return -1;
 565        }
 566        return iov_cnt;
 567}
 568
 569static inline void tcmu_free_cmd(struct tcmu_cmd *tcmu_cmd)
 570{
 571        kfree(tcmu_cmd->dbi);
 572        kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
 573}
 574
 575static inline void tcmu_cmd_set_block_cnts(struct tcmu_cmd *cmd)
 576{
 577        int i, len;
 578        struct se_cmd *se_cmd = cmd->se_cmd;
 579        uint32_t blk_size = cmd->tcmu_dev->data_blk_size;
 580
 581        cmd->dbi_cnt = DIV_ROUND_UP(se_cmd->data_length, blk_size);
 582
 583        if (se_cmd->se_cmd_flags & SCF_BIDI) {
 584                BUG_ON(!(se_cmd->t_bidi_data_sg && se_cmd->t_bidi_data_nents));
 585                for (i = 0, len = 0; i < se_cmd->t_bidi_data_nents; i++)
 586                        len += se_cmd->t_bidi_data_sg[i].length;
 587                cmd->dbi_bidi_cnt = DIV_ROUND_UP(len, blk_size);
 588                cmd->dbi_cnt += cmd->dbi_bidi_cnt;
 589                cmd->data_len_bidi = len;
 590        }
 591}
 592
 593static int new_block_to_iov(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
 594                            struct iovec **iov, int prev_dbi, int len)
 595{
 596        /* Get the next dbi */
 597        int dbi = tcmu_cmd_get_dbi(cmd);
 598
 599        /* Do not add more than udev->data_blk_size to iov */
 600        len = min_t(int,  len, udev->data_blk_size);
 601
 602        /*
 603         * The following code will gather and map the blocks to the same iovec
 604         * when the blocks are all next to each other.
 605         */
 606        if (dbi != prev_dbi + 1) {
 607                /* dbi is not next to previous dbi, so start new iov */
 608                if (prev_dbi >= 0)
 609                        (*iov)++;
 610                /* write offset relative to mb_addr */
 611                (*iov)->iov_base = (void __user *)
 612                                   (udev->data_off + dbi * udev->data_blk_size);
 613        }
 614        (*iov)->iov_len += len;
 615
 616        return dbi;
 617}
 618
 619static void tcmu_setup_iovs(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
 620                            struct iovec **iov, int data_length)
 621{
 622        /* start value of dbi + 1 must not be a valid dbi */
 623        int dbi = -2;
 624
 625        /* We prepare the IOVs for DMA_FROM_DEVICE transfer direction */
 626        for (; data_length > 0; data_length -= udev->data_blk_size)
 627                dbi = new_block_to_iov(udev, cmd, iov, dbi, data_length);
 628}
 629
 630static struct tcmu_cmd *tcmu_alloc_cmd(struct se_cmd *se_cmd)
 631{
 632        struct se_device *se_dev = se_cmd->se_dev;
 633        struct tcmu_dev *udev = TCMU_DEV(se_dev);
 634        struct tcmu_cmd *tcmu_cmd;
 635
 636        tcmu_cmd = kmem_cache_zalloc(tcmu_cmd_cache, GFP_NOIO);
 637        if (!tcmu_cmd)
 638                return NULL;
 639
 640        INIT_LIST_HEAD(&tcmu_cmd->queue_entry);
 641        tcmu_cmd->se_cmd = se_cmd;
 642        tcmu_cmd->tcmu_dev = udev;
 643
 644        tcmu_cmd_set_block_cnts(tcmu_cmd);
 645        tcmu_cmd->dbi = kcalloc(tcmu_cmd->dbi_cnt, sizeof(uint32_t),
 646                                GFP_NOIO);
 647        if (!tcmu_cmd->dbi) {
 648                kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
 649                return NULL;
 650        }
 651
 652        return tcmu_cmd;
 653}
 654
 655static inline void tcmu_flush_dcache_range(void *vaddr, size_t size)
 656{
 657        unsigned long offset = offset_in_page(vaddr);
 658        void *start = vaddr - offset;
 659
 660        size = round_up(size+offset, PAGE_SIZE);
 661
 662        while (size) {
 663                flush_dcache_page(vmalloc_to_page(start));
 664                start += PAGE_SIZE;
 665                size -= PAGE_SIZE;
 666        }
 667}
 668
 669/*
 670 * Some ring helper functions. We don't assume size is a power of 2 so
 671 * we can't use circ_buf.h.
 672 */
 673static inline size_t spc_used(size_t head, size_t tail, size_t size)
 674{
 675        int diff = head - tail;
 676
 677        if (diff >= 0)
 678                return diff;
 679        else
 680                return size + diff;
 681}
 682
 683static inline size_t spc_free(size_t head, size_t tail, size_t size)
 684{
 685        /* Keep 1 byte unused or we can't tell full from empty */
 686        return (size - spc_used(head, tail, size) - 1);
 687}
 688
 689static inline size_t head_to_end(size_t head, size_t size)
 690{
 691        return size - head;
 692}
 693
 694#define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size)
 695
 696#define TCMU_SG_TO_DATA_AREA 1
 697#define TCMU_DATA_AREA_TO_SG 2
 698
 699static inline void tcmu_copy_data(struct tcmu_dev *udev,
 700                                  struct tcmu_cmd *tcmu_cmd, uint32_t direction,
 701                                  struct scatterlist *sg, unsigned int sg_nents,
 702                                  struct iovec **iov, size_t data_len)
 703{
 704        /* start value of dbi + 1 must not be a valid dbi */
 705        int dbi = -2;
 706        size_t page_remaining, cp_len;
 707        int page_cnt, page_inx, dpi;
 708        struct sg_mapping_iter sg_iter;
 709        unsigned int sg_flags;
 710        struct page *page;
 711        void *data_page_start, *data_addr;
 712
 713        if (direction == TCMU_SG_TO_DATA_AREA)
 714                sg_flags = SG_MITER_ATOMIC | SG_MITER_FROM_SG;
 715        else
 716                sg_flags = SG_MITER_ATOMIC | SG_MITER_TO_SG;
 717        sg_miter_start(&sg_iter, sg, sg_nents, sg_flags);
 718
 719        while (data_len) {
 720                if (direction == TCMU_SG_TO_DATA_AREA)
 721                        dbi = new_block_to_iov(udev, tcmu_cmd, iov, dbi,
 722                                               data_len);
 723                else
 724                        dbi = tcmu_cmd_get_dbi(tcmu_cmd);
 725
 726                page_cnt = DIV_ROUND_UP(data_len, PAGE_SIZE);
 727                if (page_cnt > udev->data_pages_per_blk)
 728                        page_cnt = udev->data_pages_per_blk;
 729
 730                dpi = dbi * udev->data_pages_per_blk;
 731                for (page_inx = 0; page_inx < page_cnt && data_len;
 732                     page_inx++, dpi++) {
 733                        page = xa_load(&udev->data_pages, dpi);
 734
 735                        if (direction == TCMU_DATA_AREA_TO_SG)
 736                                flush_dcache_page(page);
 737                        data_page_start = kmap_atomic(page);
 738                        page_remaining = PAGE_SIZE;
 739
 740                        while (page_remaining && data_len) {
 741                                if (!sg_miter_next(&sg_iter)) {
 742                                        /* set length to 0 to abort outer loop */
 743                                        data_len = 0;
 744                                        pr_debug("%s: aborting data copy due to exhausted sg_list\n",
 745                                                 __func__);
 746                                        break;
 747                                }
 748                                cp_len = min3(sg_iter.length, page_remaining,
 749                                              data_len);
 750
 751                                data_addr = data_page_start +
 752                                            PAGE_SIZE - page_remaining;
 753                                if (direction == TCMU_SG_TO_DATA_AREA)
 754                                        memcpy(data_addr, sg_iter.addr, cp_len);
 755                                else
 756                                        memcpy(sg_iter.addr, data_addr, cp_len);
 757
 758                                data_len -= cp_len;
 759                                page_remaining -= cp_len;
 760                                sg_iter.consumed = cp_len;
 761                        }
 762                        sg_miter_stop(&sg_iter);
 763
 764                        kunmap_atomic(data_page_start);
 765                        if (direction == TCMU_SG_TO_DATA_AREA)
 766                                flush_dcache_page(page);
 767                }
 768        }
 769}
 770
 771static void scatter_data_area(struct tcmu_dev *udev, struct tcmu_cmd *tcmu_cmd,
 772                              struct iovec **iov)
 773{
 774        struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
 775
 776        tcmu_copy_data(udev, tcmu_cmd, TCMU_SG_TO_DATA_AREA, se_cmd->t_data_sg,
 777                       se_cmd->t_data_nents, iov, se_cmd->data_length);
 778}
 779
 780static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *tcmu_cmd,
 781                             bool bidi, uint32_t read_len)
 782{
 783        struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
 784        struct scatterlist *data_sg;
 785        unsigned int data_nents;
 786
 787        if (!bidi) {
 788                data_sg = se_cmd->t_data_sg;
 789                data_nents = se_cmd->t_data_nents;
 790        } else {
 791                /*
 792                 * For bidi case, the first count blocks are for Data-Out
 793                 * buffer blocks, and before gathering the Data-In buffer
 794                 * the Data-Out buffer blocks should be skipped.
 795                 */
 796                tcmu_cmd_set_dbi_cur(tcmu_cmd,
 797                                     tcmu_cmd->dbi_cnt - tcmu_cmd->dbi_bidi_cnt);
 798
 799                data_sg = se_cmd->t_bidi_data_sg;
 800                data_nents = se_cmd->t_bidi_data_nents;
 801        }
 802
 803        tcmu_copy_data(udev, tcmu_cmd, TCMU_DATA_AREA_TO_SG, data_sg,
 804                       data_nents, NULL, read_len);
 805}
 806
 807static inline size_t spc_bitmap_free(unsigned long *bitmap, uint32_t thresh)
 808{
 809        return thresh - bitmap_weight(bitmap, thresh);
 810}
 811
 812/*
 813 * We can't queue a command until we have space available on the cmd ring.
 814 *
 815 * Called with ring lock held.
 816 */
 817static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size)
 818{
 819        struct tcmu_mailbox *mb = udev->mb_addr;
 820        size_t space, cmd_needed;
 821        u32 cmd_head;
 822
 823        tcmu_flush_dcache_range(mb, sizeof(*mb));
 824
 825        cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
 826
 827        /*
 828         * If cmd end-of-ring space is too small then we need space for a NOP plus
 829         * original cmd - cmds are internally contiguous.
 830         */
 831        if (head_to_end(cmd_head, udev->cmdr_size) >= cmd_size)
 832                cmd_needed = cmd_size;
 833        else
 834                cmd_needed = cmd_size + head_to_end(cmd_head, udev->cmdr_size);
 835
 836        space = spc_free(cmd_head, udev->cmdr_last_cleaned, udev->cmdr_size);
 837        if (space < cmd_needed) {
 838                pr_debug("no cmd space: %u %u %u\n", cmd_head,
 839                       udev->cmdr_last_cleaned, udev->cmdr_size);
 840                return false;
 841        }
 842        return true;
 843}
 844
 845/*
 846 * We have to allocate data buffers before we can queue a command.
 847 * Returns -1 on error (not enough space) or number of needed iovs on success
 848 *
 849 * Called with ring lock held.
 850 */
 851static int tcmu_alloc_data_space(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
 852                                  int *iov_bidi_cnt)
 853{
 854        int space, iov_cnt = 0, ret = 0;
 855
 856        if (!cmd->dbi_cnt)
 857                goto wr_iov_cnts;
 858
 859        /* try to check and get the data blocks as needed */
 860        space = spc_bitmap_free(udev->data_bitmap, udev->dbi_thresh);
 861        if (space < cmd->dbi_cnt) {
 862                unsigned long blocks_left =
 863                                (udev->max_blocks - udev->dbi_thresh) + space;
 864
 865                if (blocks_left < cmd->dbi_cnt) {
 866                        pr_debug("no data space: only %lu available, but ask for %u\n",
 867                                        blocks_left * udev->data_blk_size,
 868                                        cmd->dbi_cnt * udev->data_blk_size);
 869                        return -1;
 870                }
 871
 872                udev->dbi_thresh += cmd->dbi_cnt;
 873                if (udev->dbi_thresh > udev->max_blocks)
 874                        udev->dbi_thresh = udev->max_blocks;
 875        }
 876
 877        iov_cnt = tcmu_get_empty_blocks(udev, cmd, cmd->se_cmd->data_length);
 878        if (iov_cnt < 0)
 879                return -1;
 880
 881        if (cmd->dbi_bidi_cnt) {
 882                ret = tcmu_get_empty_blocks(udev, cmd, cmd->data_len_bidi);
 883                if (ret < 0)
 884                        return -1;
 885        }
 886wr_iov_cnts:
 887        *iov_bidi_cnt = ret;
 888        return iov_cnt + ret;
 889}
 890
 891static inline size_t tcmu_cmd_get_base_cmd_size(size_t iov_cnt)
 892{
 893        return max(offsetof(struct tcmu_cmd_entry, req.iov[iov_cnt]),
 894                        sizeof(struct tcmu_cmd_entry));
 895}
 896
 897static inline size_t tcmu_cmd_get_cmd_size(struct tcmu_cmd *tcmu_cmd,
 898                                           size_t base_command_size)
 899{
 900        struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
 901        size_t command_size;
 902
 903        command_size = base_command_size +
 904                round_up(scsi_command_size(se_cmd->t_task_cdb),
 905                                TCMU_OP_ALIGN_SIZE);
 906
 907        WARN_ON(command_size & (TCMU_OP_ALIGN_SIZE-1));
 908
 909        return command_size;
 910}
 911
 912static void tcmu_setup_cmd_timer(struct tcmu_cmd *tcmu_cmd, unsigned int tmo,
 913                                 struct timer_list *timer)
 914{
 915        if (!tmo)
 916                return;
 917
 918        tcmu_cmd->deadline = round_jiffies_up(jiffies + msecs_to_jiffies(tmo));
 919        if (!timer_pending(timer))
 920                mod_timer(timer, tcmu_cmd->deadline);
 921
 922        pr_debug("Timeout set up for cmd %p, dev = %s, tmo = %lu\n", tcmu_cmd,
 923                 tcmu_cmd->tcmu_dev->name, tmo / MSEC_PER_SEC);
 924}
 925
 926static int add_to_qfull_queue(struct tcmu_cmd *tcmu_cmd)
 927{
 928        struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
 929        unsigned int tmo;
 930
 931        /*
 932         * For backwards compat if qfull_time_out is not set use
 933         * cmd_time_out and if that's not set use the default time out.
 934         */
 935        if (!udev->qfull_time_out)
 936                return -ETIMEDOUT;
 937        else if (udev->qfull_time_out > 0)
 938                tmo = udev->qfull_time_out;
 939        else if (udev->cmd_time_out)
 940                tmo = udev->cmd_time_out;
 941        else
 942                tmo = TCMU_TIME_OUT;
 943
 944        tcmu_setup_cmd_timer(tcmu_cmd, tmo, &udev->qfull_timer);
 945
 946        list_add_tail(&tcmu_cmd->queue_entry, &udev->qfull_queue);
 947        pr_debug("adding cmd %p on dev %s to ring space wait queue\n",
 948                 tcmu_cmd, udev->name);
 949        return 0;
 950}
 951
 952static uint32_t ring_insert_padding(struct tcmu_dev *udev, size_t cmd_size)
 953{
 954        struct tcmu_cmd_entry_hdr *hdr;
 955        struct tcmu_mailbox *mb = udev->mb_addr;
 956        uint32_t cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
 957
 958        /* Insert a PAD if end-of-ring space is too small */
 959        if (head_to_end(cmd_head, udev->cmdr_size) < cmd_size) {
 960                size_t pad_size = head_to_end(cmd_head, udev->cmdr_size);
 961
 962                hdr = udev->cmdr + cmd_head;
 963                tcmu_hdr_set_op(&hdr->len_op, TCMU_OP_PAD);
 964                tcmu_hdr_set_len(&hdr->len_op, pad_size);
 965                hdr->cmd_id = 0; /* not used for PAD */
 966                hdr->kflags = 0;
 967                hdr->uflags = 0;
 968                tcmu_flush_dcache_range(hdr, sizeof(*hdr));
 969
 970                UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size);
 971                tcmu_flush_dcache_range(mb, sizeof(*mb));
 972
 973                cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
 974                WARN_ON(cmd_head != 0);
 975        }
 976
 977        return cmd_head;
 978}
 979
 980static void tcmu_unplug_device(struct se_dev_plug *se_plug)
 981{
 982        struct se_device *se_dev = se_plug->se_dev;
 983        struct tcmu_dev *udev = TCMU_DEV(se_dev);
 984
 985        clear_bit(TCM_DEV_BIT_PLUGGED, &udev->flags);
 986        uio_event_notify(&udev->uio_info);
 987}
 988
 989static struct se_dev_plug *tcmu_plug_device(struct se_device *se_dev)
 990{
 991        struct tcmu_dev *udev = TCMU_DEV(se_dev);
 992
 993        if (!test_and_set_bit(TCM_DEV_BIT_PLUGGED, &udev->flags))
 994                return &udev->se_plug;
 995
 996        return NULL;
 997}
 998
 999/**
1000 * queue_cmd_ring - queue cmd to ring or internally
1001 * @tcmu_cmd: cmd to queue
1002 * @scsi_err: TCM error code if failure (-1) returned.
1003 *
1004 * Returns:
1005 * -1 we cannot queue internally or to the ring.
1006 *  0 success
1007 *  1 internally queued to wait for ring memory to free.
1008 */
1009static int queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, sense_reason_t *scsi_err)
1010{
1011        struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
1012        struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
1013        size_t base_command_size, command_size;
1014        struct tcmu_mailbox *mb = udev->mb_addr;
1015        struct tcmu_cmd_entry *entry;
1016        struct iovec *iov;
1017        int iov_cnt, iov_bidi_cnt;
1018        uint32_t cmd_id, cmd_head;
1019        uint64_t cdb_off;
1020        uint32_t blk_size = udev->data_blk_size;
1021        /* size of data buffer needed */
1022        size_t data_length = (size_t)tcmu_cmd->dbi_cnt * blk_size;
1023
1024        *scsi_err = TCM_NO_SENSE;
1025
1026        if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags)) {
1027                *scsi_err = TCM_LUN_BUSY;
1028                return -1;
1029        }
1030
1031        if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
1032                *scsi_err = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1033                return -1;
1034        }
1035
1036        if (!list_empty(&udev->qfull_queue))
1037                goto queue;
1038
1039        if (data_length > (size_t)udev->max_blocks * blk_size) {
1040                pr_warn("TCMU: Request of size %zu is too big for %zu data area\n",
1041                        data_length, (size_t)udev->max_blocks * blk_size);
1042                *scsi_err = TCM_INVALID_CDB_FIELD;
1043                return -1;
1044        }
1045
1046        iov_cnt = tcmu_alloc_data_space(udev, tcmu_cmd, &iov_bidi_cnt);
1047        if (iov_cnt < 0)
1048                goto free_and_queue;
1049
1050        /*
1051         * Must be a certain minimum size for response sense info, but
1052         * also may be larger if the iov array is large.
1053         */
1054        base_command_size = tcmu_cmd_get_base_cmd_size(iov_cnt);
1055        command_size = tcmu_cmd_get_cmd_size(tcmu_cmd, base_command_size);
1056
1057        if (command_size > (udev->cmdr_size / 2)) {
1058                pr_warn("TCMU: Request of size %zu is too big for %u cmd ring\n",
1059                        command_size, udev->cmdr_size);
1060                tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cur);
1061                *scsi_err = TCM_INVALID_CDB_FIELD;
1062                return -1;
1063        }
1064
1065        if (!is_ring_space_avail(udev, command_size))
1066                /*
1067                 * Don't leave commands partially setup because the unmap
1068                 * thread might need the blocks to make forward progress.
1069                 */
1070                goto free_and_queue;
1071
1072        if (xa_alloc(&udev->commands, &cmd_id, tcmu_cmd, XA_LIMIT(1, 0xffff),
1073                     GFP_NOWAIT) < 0) {
1074                pr_err("tcmu: Could not allocate cmd id.\n");
1075
1076                tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cnt);
1077                *scsi_err = TCM_OUT_OF_RESOURCES;
1078                return -1;
1079        }
1080        tcmu_cmd->cmd_id = cmd_id;
1081
1082        pr_debug("allocated cmd id %u for cmd %p dev %s\n", tcmu_cmd->cmd_id,
1083                 tcmu_cmd, udev->name);
1084
1085        cmd_head = ring_insert_padding(udev, command_size);
1086
1087        entry = udev->cmdr + cmd_head;
1088        memset(entry, 0, command_size);
1089        tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_CMD);
1090
1091        /* prepare iov list and copy data to data area if necessary */
1092        tcmu_cmd_reset_dbi_cur(tcmu_cmd);
1093        iov = &entry->req.iov[0];
1094
1095        if (se_cmd->data_direction == DMA_TO_DEVICE ||
1096            se_cmd->se_cmd_flags & SCF_BIDI)
1097                scatter_data_area(udev, tcmu_cmd, &iov);
1098        else
1099                tcmu_setup_iovs(udev, tcmu_cmd, &iov, se_cmd->data_length);
1100
1101        entry->req.iov_cnt = iov_cnt - iov_bidi_cnt;
1102
1103        /* Handle BIDI commands */
1104        if (se_cmd->se_cmd_flags & SCF_BIDI) {
1105                iov++;
1106                tcmu_setup_iovs(udev, tcmu_cmd, &iov, tcmu_cmd->data_len_bidi);
1107                entry->req.iov_bidi_cnt = iov_bidi_cnt;
1108        }
1109
1110        tcmu_setup_cmd_timer(tcmu_cmd, udev->cmd_time_out, &udev->cmd_timer);
1111
1112        entry->hdr.cmd_id = tcmu_cmd->cmd_id;
1113
1114        tcmu_hdr_set_len(&entry->hdr.len_op, command_size);
1115
1116        /* All offsets relative to mb_addr, not start of entry! */
1117        cdb_off = CMDR_OFF + cmd_head + base_command_size;
1118        memcpy((void *) mb + cdb_off, se_cmd->t_task_cdb, scsi_command_size(se_cmd->t_task_cdb));
1119        entry->req.cdb_off = cdb_off;
1120        tcmu_flush_dcache_range(entry, command_size);
1121
1122        UPDATE_HEAD(mb->cmd_head, command_size, udev->cmdr_size);
1123        tcmu_flush_dcache_range(mb, sizeof(*mb));
1124
1125        list_add_tail(&tcmu_cmd->queue_entry, &udev->inflight_queue);
1126
1127        if (!test_bit(TCM_DEV_BIT_PLUGGED, &udev->flags))
1128                uio_event_notify(&udev->uio_info);
1129
1130        return 0;
1131
1132free_and_queue:
1133        tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cur);
1134        tcmu_cmd_reset_dbi_cur(tcmu_cmd);
1135
1136queue:
1137        if (add_to_qfull_queue(tcmu_cmd)) {
1138                *scsi_err = TCM_OUT_OF_RESOURCES;
1139                return -1;
1140        }
1141
1142        return 1;
1143}
1144
1145/**
1146 * queue_tmr_ring - queue tmr info to ring or internally
1147 * @udev: related tcmu_dev
1148 * @tmr: tcmu_tmr containing tmr info to queue
1149 *
1150 * Returns:
1151 *  0 success
1152 *  1 internally queued to wait for ring memory to free.
1153 */
1154static int
1155queue_tmr_ring(struct tcmu_dev *udev, struct tcmu_tmr *tmr)
1156{
1157        struct tcmu_tmr_entry *entry;
1158        int cmd_size;
1159        int id_list_sz;
1160        struct tcmu_mailbox *mb = udev->mb_addr;
1161        uint32_t cmd_head;
1162
1163        if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags))
1164                goto out_free;
1165
1166        id_list_sz = sizeof(tmr->tmr_cmd_ids[0]) * tmr->tmr_cmd_cnt;
1167        cmd_size = round_up(sizeof(*entry) + id_list_sz, TCMU_OP_ALIGN_SIZE);
1168
1169        if (!list_empty(&udev->tmr_queue) ||
1170            !is_ring_space_avail(udev, cmd_size)) {
1171                list_add_tail(&tmr->queue_entry, &udev->tmr_queue);
1172                pr_debug("adding tmr %p on dev %s to TMR ring space wait queue\n",
1173                         tmr, udev->name);
1174                return 1;
1175        }
1176
1177        cmd_head = ring_insert_padding(udev, cmd_size);
1178
1179        entry = udev->cmdr + cmd_head;
1180        memset(entry, 0, cmd_size);
1181        tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_TMR);
1182        tcmu_hdr_set_len(&entry->hdr.len_op, cmd_size);
1183        entry->tmr_type = tmr->tmr_type;
1184        entry->cmd_cnt = tmr->tmr_cmd_cnt;
1185        memcpy(&entry->cmd_ids[0], &tmr->tmr_cmd_ids[0], id_list_sz);
1186        tcmu_flush_dcache_range(entry, cmd_size);
1187
1188        UPDATE_HEAD(mb->cmd_head, cmd_size, udev->cmdr_size);
1189        tcmu_flush_dcache_range(mb, sizeof(*mb));
1190
1191        uio_event_notify(&udev->uio_info);
1192
1193out_free:
1194        kfree(tmr);
1195
1196        return 0;
1197}
1198
1199static sense_reason_t
1200tcmu_queue_cmd(struct se_cmd *se_cmd)
1201{
1202        struct se_device *se_dev = se_cmd->se_dev;
1203        struct tcmu_dev *udev = TCMU_DEV(se_dev);
1204        struct tcmu_cmd *tcmu_cmd;
1205        sense_reason_t scsi_ret = TCM_CHECK_CONDITION_ABORT_CMD;
1206        int ret = -1;
1207
1208        tcmu_cmd = tcmu_alloc_cmd(se_cmd);
1209        if (!tcmu_cmd)
1210                return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1211
1212        mutex_lock(&udev->cmdr_lock);
1213        if (!(se_cmd->transport_state & CMD_T_ABORTED))
1214                ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
1215        if (ret < 0)
1216                tcmu_free_cmd(tcmu_cmd);
1217        else
1218                se_cmd->priv = tcmu_cmd;
1219        mutex_unlock(&udev->cmdr_lock);
1220        return scsi_ret;
1221}
1222
1223static void tcmu_set_next_deadline(struct list_head *queue,
1224                                   struct timer_list *timer)
1225{
1226        struct tcmu_cmd *cmd;
1227
1228        if (!list_empty(queue)) {
1229                cmd = list_first_entry(queue, struct tcmu_cmd, queue_entry);
1230                mod_timer(timer, cmd->deadline);
1231        } else
1232                del_timer(timer);
1233}
1234
1235static int
1236tcmu_tmr_type(enum tcm_tmreq_table tmf)
1237{
1238        switch (tmf) {
1239        case TMR_ABORT_TASK:            return TCMU_TMR_ABORT_TASK;
1240        case TMR_ABORT_TASK_SET:        return TCMU_TMR_ABORT_TASK_SET;
1241        case TMR_CLEAR_ACA:             return TCMU_TMR_CLEAR_ACA;
1242        case TMR_CLEAR_TASK_SET:        return TCMU_TMR_CLEAR_TASK_SET;
1243        case TMR_LUN_RESET:             return TCMU_TMR_LUN_RESET;
1244        case TMR_TARGET_WARM_RESET:     return TCMU_TMR_TARGET_WARM_RESET;
1245        case TMR_TARGET_COLD_RESET:     return TCMU_TMR_TARGET_COLD_RESET;
1246        case TMR_LUN_RESET_PRO:         return TCMU_TMR_LUN_RESET_PRO;
1247        default:                        return TCMU_TMR_UNKNOWN;
1248        }
1249}
1250
1251static void
1252tcmu_tmr_notify(struct se_device *se_dev, enum tcm_tmreq_table tmf,
1253                struct list_head *cmd_list)
1254{
1255        int i = 0, cmd_cnt = 0;
1256        bool unqueued = false;
1257        uint16_t *cmd_ids = NULL;
1258        struct tcmu_cmd *cmd;
1259        struct se_cmd *se_cmd;
1260        struct tcmu_tmr *tmr;
1261        struct tcmu_dev *udev = TCMU_DEV(se_dev);
1262
1263        mutex_lock(&udev->cmdr_lock);
1264
1265        /* First we check for aborted commands in qfull_queue */
1266        list_for_each_entry(se_cmd, cmd_list, state_list) {
1267                i++;
1268                if (!se_cmd->priv)
1269                        continue;
1270                cmd = se_cmd->priv;
1271                /* Commands on qfull queue have no id yet */
1272                if (cmd->cmd_id) {
1273                        cmd_cnt++;
1274                        continue;
1275                }
1276                pr_debug("Removing aborted command %p from queue on dev %s.\n",
1277                         cmd, udev->name);
1278
1279                list_del_init(&cmd->queue_entry);
1280                tcmu_free_cmd(cmd);
1281                se_cmd->priv = NULL;
1282                target_complete_cmd(se_cmd, SAM_STAT_TASK_ABORTED);
1283                unqueued = true;
1284        }
1285        if (unqueued)
1286                tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
1287
1288        if (!test_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags))
1289                goto unlock;
1290
1291        pr_debug("TMR event %d on dev %s, aborted cmds %d, afflicted cmd_ids %d\n",
1292                 tcmu_tmr_type(tmf), udev->name, i, cmd_cnt);
1293
1294        tmr = kmalloc(sizeof(*tmr) + cmd_cnt * sizeof(*cmd_ids), GFP_NOIO);
1295        if (!tmr)
1296                goto unlock;
1297
1298        tmr->tmr_type = tcmu_tmr_type(tmf);
1299        tmr->tmr_cmd_cnt = cmd_cnt;
1300
1301        if (cmd_cnt != 0) {
1302                cmd_cnt = 0;
1303                list_for_each_entry(se_cmd, cmd_list, state_list) {
1304                        if (!se_cmd->priv)
1305                                continue;
1306                        cmd = se_cmd->priv;
1307                        if (cmd->cmd_id)
1308                                tmr->tmr_cmd_ids[cmd_cnt++] = cmd->cmd_id;
1309                }
1310        }
1311
1312        queue_tmr_ring(udev, tmr);
1313
1314unlock:
1315        mutex_unlock(&udev->cmdr_lock);
1316}
1317
1318static void tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry *entry)
1319{
1320        struct se_cmd *se_cmd = cmd->se_cmd;
1321        struct tcmu_dev *udev = cmd->tcmu_dev;
1322        bool read_len_valid = false;
1323        uint32_t read_len;
1324
1325        /*
1326         * cmd has been completed already from timeout, just reclaim
1327         * data area space and free cmd
1328         */
1329        if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
1330                WARN_ON_ONCE(se_cmd);
1331                goto out;
1332        }
1333
1334        list_del_init(&cmd->queue_entry);
1335
1336        tcmu_cmd_reset_dbi_cur(cmd);
1337
1338        if (entry->hdr.uflags & TCMU_UFLAG_UNKNOWN_OP) {
1339                pr_warn("TCMU: Userspace set UNKNOWN_OP flag on se_cmd %p\n",
1340                        cmd->se_cmd);
1341                entry->rsp.scsi_status = SAM_STAT_CHECK_CONDITION;
1342                goto done;
1343        }
1344
1345        read_len = se_cmd->data_length;
1346        if (se_cmd->data_direction == DMA_FROM_DEVICE &&
1347            (entry->hdr.uflags & TCMU_UFLAG_READ_LEN) && entry->rsp.read_len) {
1348                read_len_valid = true;
1349                if (entry->rsp.read_len < read_len)
1350                        read_len = entry->rsp.read_len;
1351        }
1352
1353        if (entry->rsp.scsi_status == SAM_STAT_CHECK_CONDITION) {
1354                transport_copy_sense_to_cmd(se_cmd, entry->rsp.sense_buffer);
1355                if (!read_len_valid )
1356                        goto done;
1357                else
1358                        se_cmd->se_cmd_flags |= SCF_TREAT_READ_AS_NORMAL;
1359        }
1360        if (se_cmd->se_cmd_flags & SCF_BIDI) {
1361                /* Get Data-In buffer before clean up */
1362                gather_data_area(udev, cmd, true, read_len);
1363        } else if (se_cmd->data_direction == DMA_FROM_DEVICE) {
1364                gather_data_area(udev, cmd, false, read_len);
1365        } else if (se_cmd->data_direction == DMA_TO_DEVICE) {
1366                /* TODO: */
1367        } else if (se_cmd->data_direction != DMA_NONE) {
1368                pr_warn("TCMU: data direction was %d!\n",
1369                        se_cmd->data_direction);
1370        }
1371
1372done:
1373        se_cmd->priv = NULL;
1374        if (read_len_valid) {
1375                pr_debug("read_len = %d\n", read_len);
1376                target_complete_cmd_with_length(cmd->se_cmd,
1377                                        entry->rsp.scsi_status, read_len);
1378        } else
1379                target_complete_cmd(cmd->se_cmd, entry->rsp.scsi_status);
1380
1381out:
1382        tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
1383        tcmu_free_cmd(cmd);
1384}
1385
1386static int tcmu_run_tmr_queue(struct tcmu_dev *udev)
1387{
1388        struct tcmu_tmr *tmr, *tmp;
1389        LIST_HEAD(tmrs);
1390
1391        if (list_empty(&udev->tmr_queue))
1392                return 1;
1393
1394        pr_debug("running %s's tmr queue\n", udev->name);
1395
1396        list_splice_init(&udev->tmr_queue, &tmrs);
1397
1398        list_for_each_entry_safe(tmr, tmp, &tmrs, queue_entry) {
1399                list_del_init(&tmr->queue_entry);
1400
1401                pr_debug("removing tmr %p on dev %s from queue\n",
1402                         tmr, udev->name);
1403
1404                if (queue_tmr_ring(udev, tmr)) {
1405                        pr_debug("ran out of space during tmr queue run\n");
1406                        /*
1407                         * tmr was requeued, so just put all tmrs back in
1408                         * the queue
1409                         */
1410                        list_splice_tail(&tmrs, &udev->tmr_queue);
1411                        return 0;
1412                }
1413        }
1414
1415        return 1;
1416}
1417
1418static bool tcmu_handle_completions(struct tcmu_dev *udev)
1419{
1420        struct tcmu_mailbox *mb;
1421        struct tcmu_cmd *cmd;
1422        bool free_space = false;
1423
1424        if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
1425                pr_err("ring broken, not handling completions\n");
1426                return 0;
1427        }
1428
1429        mb = udev->mb_addr;
1430        tcmu_flush_dcache_range(mb, sizeof(*mb));
1431
1432        while (udev->cmdr_last_cleaned != READ_ONCE(mb->cmd_tail)) {
1433
1434                struct tcmu_cmd_entry *entry = udev->cmdr + udev->cmdr_last_cleaned;
1435
1436                /*
1437                 * Flush max. up to end of cmd ring since current entry might
1438                 * be a padding that is shorter than sizeof(*entry)
1439                 */
1440                size_t ring_left = head_to_end(udev->cmdr_last_cleaned,
1441                                               udev->cmdr_size);
1442                tcmu_flush_dcache_range(entry, ring_left < sizeof(*entry) ?
1443                                        ring_left : sizeof(*entry));
1444
1445                free_space = true;
1446
1447                if (tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_PAD ||
1448                    tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_TMR) {
1449                        UPDATE_HEAD(udev->cmdr_last_cleaned,
1450                                    tcmu_hdr_get_len(entry->hdr.len_op),
1451                                    udev->cmdr_size);
1452                        continue;
1453                }
1454                WARN_ON(tcmu_hdr_get_op(entry->hdr.len_op) != TCMU_OP_CMD);
1455
1456                cmd = xa_erase(&udev->commands, entry->hdr.cmd_id);
1457                if (!cmd) {
1458                        pr_err("cmd_id %u not found, ring is broken\n",
1459                               entry->hdr.cmd_id);
1460                        set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
1461                        return false;
1462                }
1463
1464                tcmu_handle_completion(cmd, entry);
1465
1466                UPDATE_HEAD(udev->cmdr_last_cleaned,
1467                            tcmu_hdr_get_len(entry->hdr.len_op),
1468                            udev->cmdr_size);
1469        }
1470        if (free_space)
1471                free_space = tcmu_run_tmr_queue(udev);
1472
1473        if (atomic_read(&global_page_count) > tcmu_global_max_pages &&
1474            xa_empty(&udev->commands) && list_empty(&udev->qfull_queue)) {
1475                /*
1476                 * Allocated blocks exceeded global block limit, currently no
1477                 * more pending or waiting commands so try to reclaim blocks.
1478                 */
1479                schedule_delayed_work(&tcmu_unmap_work, 0);
1480        }
1481        if (udev->cmd_time_out)
1482                tcmu_set_next_deadline(&udev->inflight_queue, &udev->cmd_timer);
1483
1484        return free_space;
1485}
1486
1487static void tcmu_check_expired_ring_cmd(struct tcmu_cmd *cmd)
1488{
1489        struct se_cmd *se_cmd;
1490
1491        if (!time_after_eq(jiffies, cmd->deadline))
1492                return;
1493
1494        set_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags);
1495        list_del_init(&cmd->queue_entry);
1496        se_cmd = cmd->se_cmd;
1497        se_cmd->priv = NULL;
1498        cmd->se_cmd = NULL;
1499
1500        pr_debug("Timing out inflight cmd %u on dev %s.\n",
1501                 cmd->cmd_id, cmd->tcmu_dev->name);
1502
1503        target_complete_cmd(se_cmd, SAM_STAT_CHECK_CONDITION);
1504}
1505
1506static void tcmu_check_expired_queue_cmd(struct tcmu_cmd *cmd)
1507{
1508        struct se_cmd *se_cmd;
1509
1510        if (!time_after_eq(jiffies, cmd->deadline))
1511                return;
1512
1513        pr_debug("Timing out queued cmd %p on dev %s.\n",
1514                  cmd, cmd->tcmu_dev->name);
1515
1516        list_del_init(&cmd->queue_entry);
1517        se_cmd = cmd->se_cmd;
1518        tcmu_free_cmd(cmd);
1519
1520        se_cmd->priv = NULL;
1521        target_complete_cmd(se_cmd, SAM_STAT_TASK_SET_FULL);
1522}
1523
1524static void tcmu_device_timedout(struct tcmu_dev *udev)
1525{
1526        spin_lock(&timed_out_udevs_lock);
1527        if (list_empty(&udev->timedout_entry))
1528                list_add_tail(&udev->timedout_entry, &timed_out_udevs);
1529        spin_unlock(&timed_out_udevs_lock);
1530
1531        schedule_delayed_work(&tcmu_unmap_work, 0);
1532}
1533
1534static void tcmu_cmd_timedout(struct timer_list *t)
1535{
1536        struct tcmu_dev *udev = from_timer(udev, t, cmd_timer);
1537
1538        pr_debug("%s cmd timeout has expired\n", udev->name);
1539        tcmu_device_timedout(udev);
1540}
1541
1542static void tcmu_qfull_timedout(struct timer_list *t)
1543{
1544        struct tcmu_dev *udev = from_timer(udev, t, qfull_timer);
1545
1546        pr_debug("%s qfull timeout has expired\n", udev->name);
1547        tcmu_device_timedout(udev);
1548}
1549
1550static int tcmu_attach_hba(struct se_hba *hba, u32 host_id)
1551{
1552        struct tcmu_hba *tcmu_hba;
1553
1554        tcmu_hba = kzalloc(sizeof(struct tcmu_hba), GFP_KERNEL);
1555        if (!tcmu_hba)
1556                return -ENOMEM;
1557
1558        tcmu_hba->host_id = host_id;
1559        hba->hba_ptr = tcmu_hba;
1560
1561        return 0;
1562}
1563
1564static void tcmu_detach_hba(struct se_hba *hba)
1565{
1566        kfree(hba->hba_ptr);
1567        hba->hba_ptr = NULL;
1568}
1569
1570static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name)
1571{
1572        struct tcmu_dev *udev;
1573
1574        udev = kzalloc(sizeof(struct tcmu_dev), GFP_KERNEL);
1575        if (!udev)
1576                return NULL;
1577        kref_init(&udev->kref);
1578
1579        udev->name = kstrdup(name, GFP_KERNEL);
1580        if (!udev->name) {
1581                kfree(udev);
1582                return NULL;
1583        }
1584
1585        udev->hba = hba;
1586        udev->cmd_time_out = TCMU_TIME_OUT;
1587        udev->qfull_time_out = -1;
1588
1589        udev->data_pages_per_blk = DATA_PAGES_PER_BLK_DEF;
1590        udev->max_blocks = DATA_AREA_PAGES_DEF / udev->data_pages_per_blk;
1591        udev->data_area_mb = TCMU_PAGES_TO_MBS(DATA_AREA_PAGES_DEF);
1592
1593        mutex_init(&udev->cmdr_lock);
1594
1595        INIT_LIST_HEAD(&udev->node);
1596        INIT_LIST_HEAD(&udev->timedout_entry);
1597        INIT_LIST_HEAD(&udev->qfull_queue);
1598        INIT_LIST_HEAD(&udev->tmr_queue);
1599        INIT_LIST_HEAD(&udev->inflight_queue);
1600        xa_init_flags(&udev->commands, XA_FLAGS_ALLOC1);
1601
1602        timer_setup(&udev->qfull_timer, tcmu_qfull_timedout, 0);
1603        timer_setup(&udev->cmd_timer, tcmu_cmd_timedout, 0);
1604
1605        xa_init(&udev->data_pages);
1606
1607        return &udev->se_dev;
1608}
1609
1610static void tcmu_dev_call_rcu(struct rcu_head *p)
1611{
1612        struct se_device *dev = container_of(p, struct se_device, rcu_head);
1613        struct tcmu_dev *udev = TCMU_DEV(dev);
1614
1615        kfree(udev->uio_info.name);
1616        kfree(udev->name);
1617        kfree(udev);
1618}
1619
1620static int tcmu_check_and_free_pending_cmd(struct tcmu_cmd *cmd)
1621{
1622        if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
1623                kmem_cache_free(tcmu_cmd_cache, cmd);
1624                return 0;
1625        }
1626        return -EINVAL;
1627}
1628
1629static u32 tcmu_blocks_release(struct tcmu_dev *udev, unsigned long first,
1630                                unsigned long last)
1631{
1632        XA_STATE(xas, &udev->data_pages, first * udev->data_pages_per_blk);
1633        struct page *page;
1634        u32 pages_freed = 0;
1635
1636        xas_lock(&xas);
1637        xas_for_each(&xas, page, (last + 1) * udev->data_pages_per_blk - 1) {
1638                xas_store(&xas, NULL);
1639                __free_page(page);
1640                pages_freed++;
1641        }
1642        xas_unlock(&xas);
1643
1644        atomic_sub(pages_freed, &global_page_count);
1645
1646        return pages_freed;
1647}
1648
1649static void tcmu_remove_all_queued_tmr(struct tcmu_dev *udev)
1650{
1651        struct tcmu_tmr *tmr, *tmp;
1652
1653        list_for_each_entry_safe(tmr, tmp, &udev->tmr_queue, queue_entry) {
1654                list_del_init(&tmr->queue_entry);
1655                kfree(tmr);
1656        }
1657}
1658
1659static void tcmu_dev_kref_release(struct kref *kref)
1660{
1661        struct tcmu_dev *udev = container_of(kref, struct tcmu_dev, kref);
1662        struct se_device *dev = &udev->se_dev;
1663        struct tcmu_cmd *cmd;
1664        bool all_expired = true;
1665        unsigned long i;
1666
1667        vfree(udev->mb_addr);
1668        udev->mb_addr = NULL;
1669
1670        spin_lock_bh(&timed_out_udevs_lock);
1671        if (!list_empty(&udev->timedout_entry))
1672                list_del(&udev->timedout_entry);
1673        spin_unlock_bh(&timed_out_udevs_lock);
1674
1675        /* Upper layer should drain all requests before calling this */
1676        mutex_lock(&udev->cmdr_lock);
1677        xa_for_each(&udev->commands, i, cmd) {
1678                if (tcmu_check_and_free_pending_cmd(cmd) != 0)
1679                        all_expired = false;
1680        }
1681        /* There can be left over TMR cmds. Remove them. */
1682        tcmu_remove_all_queued_tmr(udev);
1683        if (!list_empty(&udev->qfull_queue))
1684                all_expired = false;
1685        xa_destroy(&udev->commands);
1686        WARN_ON(!all_expired);
1687
1688        tcmu_blocks_release(udev, 0, udev->dbi_max);
1689        bitmap_free(udev->data_bitmap);
1690        mutex_unlock(&udev->cmdr_lock);
1691
1692        pr_debug("dev_kref_release\n");
1693
1694        call_rcu(&dev->rcu_head, tcmu_dev_call_rcu);
1695}
1696
1697static void run_qfull_queue(struct tcmu_dev *udev, bool fail)
1698{
1699        struct tcmu_cmd *tcmu_cmd, *tmp_cmd;
1700        LIST_HEAD(cmds);
1701        sense_reason_t scsi_ret;
1702        int ret;
1703
1704        if (list_empty(&udev->qfull_queue))
1705                return;
1706
1707        pr_debug("running %s's cmdr queue forcefail %d\n", udev->name, fail);
1708
1709        list_splice_init(&udev->qfull_queue, &cmds);
1710
1711        list_for_each_entry_safe(tcmu_cmd, tmp_cmd, &cmds, queue_entry) {
1712                list_del_init(&tcmu_cmd->queue_entry);
1713
1714                pr_debug("removing cmd %p on dev %s from queue\n",
1715                         tcmu_cmd, udev->name);
1716
1717                if (fail) {
1718                        /*
1719                         * We were not able to even start the command, so
1720                         * fail with busy to allow a retry in case runner
1721                         * was only temporarily down. If the device is being
1722                         * removed then LIO core will do the right thing and
1723                         * fail the retry.
1724                         */
1725                        tcmu_cmd->se_cmd->priv = NULL;
1726                        target_complete_cmd(tcmu_cmd->se_cmd, SAM_STAT_BUSY);
1727                        tcmu_free_cmd(tcmu_cmd);
1728                        continue;
1729                }
1730
1731                ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
1732                if (ret < 0) {
1733                        pr_debug("cmd %p on dev %s failed with %u\n",
1734                                 tcmu_cmd, udev->name, scsi_ret);
1735                        /*
1736                         * Ignore scsi_ret for now. target_complete_cmd
1737                         * drops it.
1738                         */
1739                        tcmu_cmd->se_cmd->priv = NULL;
1740                        target_complete_cmd(tcmu_cmd->se_cmd,
1741                                            SAM_STAT_CHECK_CONDITION);
1742                        tcmu_free_cmd(tcmu_cmd);
1743                } else if (ret > 0) {
1744                        pr_debug("ran out of space during cmdr queue run\n");
1745                        /*
1746                         * cmd was requeued, so just put all cmds back in
1747                         * the queue
1748                         */
1749                        list_splice_tail(&cmds, &udev->qfull_queue);
1750                        break;
1751                }
1752        }
1753
1754        tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
1755}
1756
1757static int tcmu_irqcontrol(struct uio_info *info, s32 irq_on)
1758{
1759        struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1760
1761        mutex_lock(&udev->cmdr_lock);
1762        if (tcmu_handle_completions(udev))
1763                run_qfull_queue(udev, false);
1764        mutex_unlock(&udev->cmdr_lock);
1765
1766        return 0;
1767}
1768
1769/*
1770 * mmap code from uio.c. Copied here because we want to hook mmap()
1771 * and this stuff must come along.
1772 */
1773static int tcmu_find_mem_index(struct vm_area_struct *vma)
1774{
1775        struct tcmu_dev *udev = vma->vm_private_data;
1776        struct uio_info *info = &udev->uio_info;
1777
1778        if (vma->vm_pgoff < MAX_UIO_MAPS) {
1779                if (info->mem[vma->vm_pgoff].size == 0)
1780                        return -1;
1781                return (int)vma->vm_pgoff;
1782        }
1783        return -1;
1784}
1785
1786static struct page *tcmu_try_get_data_page(struct tcmu_dev *udev, uint32_t dpi)
1787{
1788        struct page *page;
1789
1790        mutex_lock(&udev->cmdr_lock);
1791        page = xa_load(&udev->data_pages, dpi);
1792        if (likely(page)) {
1793                mutex_unlock(&udev->cmdr_lock);
1794                return page;
1795        }
1796
1797        /*
1798         * Userspace messed up and passed in a address not in the
1799         * data iov passed to it.
1800         */
1801        pr_err("Invalid addr to data page mapping (dpi %u) on device %s\n",
1802               dpi, udev->name);
1803        mutex_unlock(&udev->cmdr_lock);
1804
1805        return NULL;
1806}
1807
1808static void tcmu_vma_open(struct vm_area_struct *vma)
1809{
1810        struct tcmu_dev *udev = vma->vm_private_data;
1811
1812        pr_debug("vma_open\n");
1813
1814        kref_get(&udev->kref);
1815}
1816
1817static void tcmu_vma_close(struct vm_area_struct *vma)
1818{
1819        struct tcmu_dev *udev = vma->vm_private_data;
1820
1821        pr_debug("vma_close\n");
1822
1823        /* release ref from tcmu_vma_open */
1824        kref_put(&udev->kref, tcmu_dev_kref_release);
1825}
1826
1827static vm_fault_t tcmu_vma_fault(struct vm_fault *vmf)
1828{
1829        struct tcmu_dev *udev = vmf->vma->vm_private_data;
1830        struct uio_info *info = &udev->uio_info;
1831        struct page *page;
1832        unsigned long offset;
1833        void *addr;
1834
1835        int mi = tcmu_find_mem_index(vmf->vma);
1836        if (mi < 0)
1837                return VM_FAULT_SIGBUS;
1838
1839        /*
1840         * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
1841         * to use mem[N].
1842         */
1843        offset = (vmf->pgoff - mi) << PAGE_SHIFT;
1844
1845        if (offset < udev->data_off) {
1846                /* For the vmalloc()ed cmd area pages */
1847                addr = (void *)(unsigned long)info->mem[mi].addr + offset;
1848                page = vmalloc_to_page(addr);
1849        } else {
1850                uint32_t dpi;
1851
1852                /* For the dynamically growing data area pages */
1853                dpi = (offset - udev->data_off) / PAGE_SIZE;
1854                page = tcmu_try_get_data_page(udev, dpi);
1855                if (!page)
1856                        return VM_FAULT_SIGBUS;
1857        }
1858
1859        get_page(page);
1860        vmf->page = page;
1861        return 0;
1862}
1863
1864static const struct vm_operations_struct tcmu_vm_ops = {
1865        .open = tcmu_vma_open,
1866        .close = tcmu_vma_close,
1867        .fault = tcmu_vma_fault,
1868};
1869
1870static int tcmu_mmap(struct uio_info *info, struct vm_area_struct *vma)
1871{
1872        struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1873
1874        vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
1875        vma->vm_ops = &tcmu_vm_ops;
1876
1877        vma->vm_private_data = udev;
1878
1879        /* Ensure the mmap is exactly the right size */
1880        if (vma_pages(vma) != udev->mmap_pages)
1881                return -EINVAL;
1882
1883        tcmu_vma_open(vma);
1884
1885        return 0;
1886}
1887
1888static int tcmu_open(struct uio_info *info, struct inode *inode)
1889{
1890        struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1891
1892        /* O_EXCL not supported for char devs, so fake it? */
1893        if (test_and_set_bit(TCMU_DEV_BIT_OPEN, &udev->flags))
1894                return -EBUSY;
1895
1896        udev->inode = inode;
1897
1898        pr_debug("open\n");
1899
1900        return 0;
1901}
1902
1903static int tcmu_release(struct uio_info *info, struct inode *inode)
1904{
1905        struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1906
1907        clear_bit(TCMU_DEV_BIT_OPEN, &udev->flags);
1908
1909        pr_debug("close\n");
1910
1911        return 0;
1912}
1913
1914static int tcmu_init_genl_cmd_reply(struct tcmu_dev *udev, int cmd)
1915{
1916        struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
1917
1918        if (!tcmu_kern_cmd_reply_supported)
1919                return 0;
1920
1921        if (udev->nl_reply_supported <= 0)
1922                return 0;
1923
1924        mutex_lock(&tcmu_nl_cmd_mutex);
1925
1926        if (tcmu_netlink_blocked) {
1927                mutex_unlock(&tcmu_nl_cmd_mutex);
1928                pr_warn("Failing nl cmd %d on %s. Interface is blocked.\n", cmd,
1929                        udev->name);
1930                return -EAGAIN;
1931        }
1932
1933        if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
1934                mutex_unlock(&tcmu_nl_cmd_mutex);
1935                pr_warn("netlink cmd %d already executing on %s\n",
1936                         nl_cmd->cmd, udev->name);
1937                return -EBUSY;
1938        }
1939
1940        memset(nl_cmd, 0, sizeof(*nl_cmd));
1941        nl_cmd->cmd = cmd;
1942        nl_cmd->udev = udev;
1943        init_completion(&nl_cmd->complete);
1944        INIT_LIST_HEAD(&nl_cmd->nl_list);
1945
1946        list_add_tail(&nl_cmd->nl_list, &tcmu_nl_cmd_list);
1947
1948        mutex_unlock(&tcmu_nl_cmd_mutex);
1949        return 0;
1950}
1951
1952static void tcmu_destroy_genl_cmd_reply(struct tcmu_dev *udev)
1953{
1954        struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
1955
1956        if (!tcmu_kern_cmd_reply_supported)
1957                return;
1958
1959        if (udev->nl_reply_supported <= 0)
1960                return;
1961
1962        mutex_lock(&tcmu_nl_cmd_mutex);
1963
1964        list_del(&nl_cmd->nl_list);
1965        memset(nl_cmd, 0, sizeof(*nl_cmd));
1966
1967        mutex_unlock(&tcmu_nl_cmd_mutex);
1968}
1969
1970static int tcmu_wait_genl_cmd_reply(struct tcmu_dev *udev)
1971{
1972        struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
1973        int ret;
1974
1975        if (!tcmu_kern_cmd_reply_supported)
1976                return 0;
1977
1978        if (udev->nl_reply_supported <= 0)
1979                return 0;
1980
1981        pr_debug("sleeping for nl reply\n");
1982        wait_for_completion(&nl_cmd->complete);
1983
1984        mutex_lock(&tcmu_nl_cmd_mutex);
1985        nl_cmd->cmd = TCMU_CMD_UNSPEC;
1986        ret = nl_cmd->status;
1987        mutex_unlock(&tcmu_nl_cmd_mutex);
1988
1989        return ret;
1990}
1991
1992static int tcmu_netlink_event_init(struct tcmu_dev *udev,
1993                                   enum tcmu_genl_cmd cmd,
1994                                   struct sk_buff **buf, void **hdr)
1995{
1996        struct sk_buff *skb;
1997        void *msg_header;
1998        int ret = -ENOMEM;
1999
2000        skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2001        if (!skb)
2002                return ret;
2003
2004        msg_header = genlmsg_put(skb, 0, 0, &tcmu_genl_family, 0, cmd);
2005        if (!msg_header)
2006                goto free_skb;
2007
2008        ret = nla_put_string(skb, TCMU_ATTR_DEVICE, udev->uio_info.name);
2009        if (ret < 0)
2010                goto free_skb;
2011
2012        ret = nla_put_u32(skb, TCMU_ATTR_MINOR, udev->uio_info.uio_dev->minor);
2013        if (ret < 0)
2014                goto free_skb;
2015
2016        ret = nla_put_u32(skb, TCMU_ATTR_DEVICE_ID, udev->se_dev.dev_index);
2017        if (ret < 0)
2018                goto free_skb;
2019
2020        *buf = skb;
2021        *hdr = msg_header;
2022        return ret;
2023
2024free_skb:
2025        nlmsg_free(skb);
2026        return ret;
2027}
2028
2029static int tcmu_netlink_event_send(struct tcmu_dev *udev,
2030                                   enum tcmu_genl_cmd cmd,
2031                                   struct sk_buff *skb, void *msg_header)
2032{
2033        int ret;
2034
2035        genlmsg_end(skb, msg_header);
2036
2037        ret = tcmu_init_genl_cmd_reply(udev, cmd);
2038        if (ret) {
2039                nlmsg_free(skb);
2040                return ret;
2041        }
2042
2043        ret = genlmsg_multicast_allns(&tcmu_genl_family, skb, 0,
2044                                      TCMU_MCGRP_CONFIG, GFP_KERNEL);
2045
2046        /* Wait during an add as the listener may not be up yet */
2047        if (ret == 0 ||
2048           (ret == -ESRCH && cmd == TCMU_CMD_ADDED_DEVICE))
2049                return tcmu_wait_genl_cmd_reply(udev);
2050        else
2051                tcmu_destroy_genl_cmd_reply(udev);
2052
2053        return ret;
2054}
2055
2056static int tcmu_send_dev_add_event(struct tcmu_dev *udev)
2057{
2058        struct sk_buff *skb = NULL;
2059        void *msg_header = NULL;
2060        int ret = 0;
2061
2062        ret = tcmu_netlink_event_init(udev, TCMU_CMD_ADDED_DEVICE, &skb,
2063                                      &msg_header);
2064        if (ret < 0)
2065                return ret;
2066        return tcmu_netlink_event_send(udev, TCMU_CMD_ADDED_DEVICE, skb,
2067                                       msg_header);
2068}
2069
2070static int tcmu_send_dev_remove_event(struct tcmu_dev *udev)
2071{
2072        struct sk_buff *skb = NULL;
2073        void *msg_header = NULL;
2074        int ret = 0;
2075
2076        ret = tcmu_netlink_event_init(udev, TCMU_CMD_REMOVED_DEVICE,
2077                                      &skb, &msg_header);
2078        if (ret < 0)
2079                return ret;
2080        return tcmu_netlink_event_send(udev, TCMU_CMD_REMOVED_DEVICE,
2081                                       skb, msg_header);
2082}
2083
2084static int tcmu_update_uio_info(struct tcmu_dev *udev)
2085{
2086        struct tcmu_hba *hba = udev->hba->hba_ptr;
2087        struct uio_info *info;
2088        char *str;
2089
2090        info = &udev->uio_info;
2091
2092        if (udev->dev_config[0])
2093                str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s/%s", hba->host_id,
2094                                udev->name, udev->dev_config);
2095        else
2096                str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s", hba->host_id,
2097                                udev->name);
2098        if (!str)
2099                return -ENOMEM;
2100
2101        /* If the old string exists, free it */
2102        kfree(info->name);
2103        info->name = str;
2104
2105        return 0;
2106}
2107
2108static int tcmu_configure_device(struct se_device *dev)
2109{
2110        struct tcmu_dev *udev = TCMU_DEV(dev);
2111        struct uio_info *info;
2112        struct tcmu_mailbox *mb;
2113        size_t data_size;
2114        int ret = 0;
2115
2116        ret = tcmu_update_uio_info(udev);
2117        if (ret)
2118                return ret;
2119
2120        info = &udev->uio_info;
2121
2122        mutex_lock(&udev->cmdr_lock);
2123        udev->data_bitmap = bitmap_zalloc(udev->max_blocks, GFP_KERNEL);
2124        mutex_unlock(&udev->cmdr_lock);
2125        if (!udev->data_bitmap) {
2126                ret = -ENOMEM;
2127                goto err_bitmap_alloc;
2128        }
2129
2130        mb = vzalloc(MB_CMDR_SIZE);
2131        if (!mb) {
2132                ret = -ENOMEM;
2133                goto err_vzalloc;
2134        }
2135
2136        /* mailbox fits in first part of CMDR space */
2137        udev->mb_addr = mb;
2138        udev->cmdr = (void *)mb + CMDR_OFF;
2139        udev->cmdr_size = CMDR_SIZE;
2140        udev->data_off = MB_CMDR_SIZE;
2141        data_size = TCMU_MBS_TO_PAGES(udev->data_area_mb) << PAGE_SHIFT;
2142        udev->mmap_pages = (data_size + MB_CMDR_SIZE) >> PAGE_SHIFT;
2143        udev->data_blk_size = udev->data_pages_per_blk * PAGE_SIZE;
2144        udev->dbi_thresh = 0; /* Default in Idle state */
2145
2146        /* Initialise the mailbox of the ring buffer */
2147        mb->version = TCMU_MAILBOX_VERSION;
2148        mb->flags = TCMU_MAILBOX_FLAG_CAP_OOOC |
2149                    TCMU_MAILBOX_FLAG_CAP_READ_LEN |
2150                    TCMU_MAILBOX_FLAG_CAP_TMR;
2151        mb->cmdr_off = CMDR_OFF;
2152        mb->cmdr_size = udev->cmdr_size;
2153
2154        WARN_ON(!PAGE_ALIGNED(udev->data_off));
2155        WARN_ON(data_size % PAGE_SIZE);
2156
2157        info->version = __stringify(TCMU_MAILBOX_VERSION);
2158
2159        info->mem[0].name = "tcm-user command & data buffer";
2160        info->mem[0].addr = (phys_addr_t)(uintptr_t)udev->mb_addr;
2161        info->mem[0].size = data_size + MB_CMDR_SIZE;
2162        info->mem[0].memtype = UIO_MEM_NONE;
2163
2164        info->irqcontrol = tcmu_irqcontrol;
2165        info->irq = UIO_IRQ_CUSTOM;
2166
2167        info->mmap = tcmu_mmap;
2168        info->open = tcmu_open;
2169        info->release = tcmu_release;
2170
2171        ret = uio_register_device(tcmu_root_device, info);
2172        if (ret)
2173                goto err_register;
2174
2175        /* User can set hw_block_size before enable the device */
2176        if (dev->dev_attrib.hw_block_size == 0)
2177                dev->dev_attrib.hw_block_size = 512;
2178        /* Other attributes can be configured in userspace */
2179        if (!dev->dev_attrib.hw_max_sectors)
2180                dev->dev_attrib.hw_max_sectors = 128;
2181        if (!dev->dev_attrib.emulate_write_cache)
2182                dev->dev_attrib.emulate_write_cache = 0;
2183        dev->dev_attrib.hw_queue_depth = 128;
2184
2185        /* If user didn't explicitly disable netlink reply support, use
2186         * module scope setting.
2187         */
2188        if (udev->nl_reply_supported >= 0)
2189                udev->nl_reply_supported = tcmu_kern_cmd_reply_supported;
2190
2191        /*
2192         * Get a ref incase userspace does a close on the uio device before
2193         * LIO has initiated tcmu_free_device.
2194         */
2195        kref_get(&udev->kref);
2196
2197        ret = tcmu_send_dev_add_event(udev);
2198        if (ret)
2199                goto err_netlink;
2200
2201        mutex_lock(&root_udev_mutex);
2202        list_add(&udev->node, &root_udev);
2203        mutex_unlock(&root_udev_mutex);
2204
2205        return 0;
2206
2207err_netlink:
2208        kref_put(&udev->kref, tcmu_dev_kref_release);
2209        uio_unregister_device(&udev->uio_info);
2210err_register:
2211        vfree(udev->mb_addr);
2212        udev->mb_addr = NULL;
2213err_vzalloc:
2214        bitmap_free(udev->data_bitmap);
2215        udev->data_bitmap = NULL;
2216err_bitmap_alloc:
2217        kfree(info->name);
2218        info->name = NULL;
2219
2220        return ret;
2221}
2222
2223static void tcmu_free_device(struct se_device *dev)
2224{
2225        struct tcmu_dev *udev = TCMU_DEV(dev);
2226
2227        /* release ref from init */
2228        kref_put(&udev->kref, tcmu_dev_kref_release);
2229}
2230
2231static void tcmu_destroy_device(struct se_device *dev)
2232{
2233        struct tcmu_dev *udev = TCMU_DEV(dev);
2234
2235        del_timer_sync(&udev->cmd_timer);
2236        del_timer_sync(&udev->qfull_timer);
2237
2238        mutex_lock(&root_udev_mutex);
2239        list_del(&udev->node);
2240        mutex_unlock(&root_udev_mutex);
2241
2242        tcmu_send_dev_remove_event(udev);
2243
2244        uio_unregister_device(&udev->uio_info);
2245
2246        /* release ref from configure */
2247        kref_put(&udev->kref, tcmu_dev_kref_release);
2248}
2249
2250static void tcmu_unblock_dev(struct tcmu_dev *udev)
2251{
2252        mutex_lock(&udev->cmdr_lock);
2253        clear_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags);
2254        mutex_unlock(&udev->cmdr_lock);
2255}
2256
2257static void tcmu_block_dev(struct tcmu_dev *udev)
2258{
2259        mutex_lock(&udev->cmdr_lock);
2260
2261        if (test_and_set_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
2262                goto unlock;
2263
2264        /* complete IO that has executed successfully */
2265        tcmu_handle_completions(udev);
2266        /* fail IO waiting to be queued */
2267        run_qfull_queue(udev, true);
2268
2269unlock:
2270        mutex_unlock(&udev->cmdr_lock);
2271}
2272
2273static void tcmu_reset_ring(struct tcmu_dev *udev, u8 err_level)
2274{
2275        struct tcmu_mailbox *mb;
2276        struct tcmu_cmd *cmd;
2277        unsigned long i;
2278
2279        mutex_lock(&udev->cmdr_lock);
2280
2281        xa_for_each(&udev->commands, i, cmd) {
2282                pr_debug("removing cmd %u on dev %s from ring (is expired %d)\n",
2283                          cmd->cmd_id, udev->name,
2284                          test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags));
2285
2286                xa_erase(&udev->commands, i);
2287                if (!test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
2288                        WARN_ON(!cmd->se_cmd);
2289                        list_del_init(&cmd->queue_entry);
2290                        cmd->se_cmd->priv = NULL;
2291                        if (err_level == 1) {
2292                                /*
2293                                 * Userspace was not able to start the
2294                                 * command or it is retryable.
2295                                 */
2296                                target_complete_cmd(cmd->se_cmd, SAM_STAT_BUSY);
2297                        } else {
2298                                /* hard failure */
2299                                target_complete_cmd(cmd->se_cmd,
2300                                                    SAM_STAT_CHECK_CONDITION);
2301                        }
2302                }
2303                tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
2304                tcmu_free_cmd(cmd);
2305        }
2306
2307        mb = udev->mb_addr;
2308        tcmu_flush_dcache_range(mb, sizeof(*mb));
2309        pr_debug("mb last %u head %u tail %u\n", udev->cmdr_last_cleaned,
2310                 mb->cmd_tail, mb->cmd_head);
2311
2312        udev->cmdr_last_cleaned = 0;
2313        mb->cmd_tail = 0;
2314        mb->cmd_head = 0;
2315        tcmu_flush_dcache_range(mb, sizeof(*mb));
2316        clear_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
2317
2318        del_timer(&udev->cmd_timer);
2319
2320        /*
2321         * ring is empty and qfull queue never contains aborted commands.
2322         * So TMRs in tmr queue do not contain relevant cmd_ids.
2323         * After a ring reset userspace should do a fresh start, so
2324         * even LUN RESET message is no longer relevant.
2325         * Therefore remove all TMRs from qfull queue
2326         */
2327        tcmu_remove_all_queued_tmr(udev);
2328
2329        run_qfull_queue(udev, false);
2330
2331        mutex_unlock(&udev->cmdr_lock);
2332}
2333
2334enum {
2335        Opt_dev_config, Opt_dev_size, Opt_hw_block_size, Opt_hw_max_sectors,
2336        Opt_nl_reply_supported, Opt_max_data_area_mb, Opt_data_pages_per_blk,
2337        Opt_err,
2338};
2339
2340static match_table_t tokens = {
2341        {Opt_dev_config, "dev_config=%s"},
2342        {Opt_dev_size, "dev_size=%s"},
2343        {Opt_hw_block_size, "hw_block_size=%d"},
2344        {Opt_hw_max_sectors, "hw_max_sectors=%d"},
2345        {Opt_nl_reply_supported, "nl_reply_supported=%d"},
2346        {Opt_max_data_area_mb, "max_data_area_mb=%d"},
2347        {Opt_data_pages_per_blk, "data_pages_per_blk=%d"},
2348        {Opt_err, NULL}
2349};
2350
2351static int tcmu_set_dev_attrib(substring_t *arg, u32 *dev_attrib)
2352{
2353        int val, ret;
2354
2355        ret = match_int(arg, &val);
2356        if (ret < 0) {
2357                pr_err("match_int() failed for dev attrib. Error %d.\n",
2358                       ret);
2359                return ret;
2360        }
2361
2362        if (val <= 0) {
2363                pr_err("Invalid dev attrib value %d. Must be greater than zero.\n",
2364                       val);
2365                return -EINVAL;
2366        }
2367        *dev_attrib = val;
2368        return 0;
2369}
2370
2371static int tcmu_set_max_blocks_param(struct tcmu_dev *udev, substring_t *arg)
2372{
2373        int val, ret;
2374        uint32_t pages_per_blk = udev->data_pages_per_blk;
2375
2376        ret = match_int(arg, &val);
2377        if (ret < 0) {
2378                pr_err("match_int() failed for max_data_area_mb=. Error %d.\n",
2379                       ret);
2380                return ret;
2381        }
2382        if (val <= 0) {
2383                pr_err("Invalid max_data_area %d.\n", val);
2384                return -EINVAL;
2385        }
2386        if (val > TCMU_PAGES_TO_MBS(tcmu_global_max_pages)) {
2387                pr_err("%d is too large. Adjusting max_data_area_mb to global limit of %u\n",
2388                       val, TCMU_PAGES_TO_MBS(tcmu_global_max_pages));
2389                val = TCMU_PAGES_TO_MBS(tcmu_global_max_pages);
2390        }
2391        if (TCMU_MBS_TO_PAGES(val) < pages_per_blk) {
2392                pr_err("Invalid max_data_area %d (%zu pages): smaller than data_pages_per_blk (%u pages).\n",
2393                       val, TCMU_MBS_TO_PAGES(val), pages_per_blk);
2394                return -EINVAL;
2395        }
2396
2397        mutex_lock(&udev->cmdr_lock);
2398        if (udev->data_bitmap) {
2399                pr_err("Cannot set max_data_area_mb after it has been enabled.\n");
2400                ret = -EINVAL;
2401                goto unlock;
2402        }
2403
2404        udev->data_area_mb = val;
2405        udev->max_blocks = TCMU_MBS_TO_PAGES(val) / pages_per_blk;
2406
2407unlock:
2408        mutex_unlock(&udev->cmdr_lock);
2409        return ret;
2410}
2411
2412static int tcmu_set_data_pages_per_blk(struct tcmu_dev *udev, substring_t *arg)
2413{
2414        int val, ret;
2415
2416        ret = match_int(arg, &val);
2417        if (ret < 0) {
2418                pr_err("match_int() failed for data_pages_per_blk=. Error %d.\n",
2419                       ret);
2420                return ret;
2421        }
2422
2423        if (val > TCMU_MBS_TO_PAGES(udev->data_area_mb)) {
2424                pr_err("Invalid data_pages_per_blk %d: greater than max_data_area_mb %d -> %zd pages).\n",
2425                       val, udev->data_area_mb,
2426                       TCMU_MBS_TO_PAGES(udev->data_area_mb));
2427                return -EINVAL;
2428        }
2429
2430        mutex_lock(&udev->cmdr_lock);
2431        if (udev->data_bitmap) {
2432                pr_err("Cannot set data_pages_per_blk after it has been enabled.\n");
2433                ret = -EINVAL;
2434                goto unlock;
2435        }
2436
2437        udev->data_pages_per_blk = val;
2438        udev->max_blocks = TCMU_MBS_TO_PAGES(udev->data_area_mb) / val;
2439
2440unlock:
2441        mutex_unlock(&udev->cmdr_lock);
2442        return ret;
2443}
2444
2445static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev,
2446                const char *page, ssize_t count)
2447{
2448        struct tcmu_dev *udev = TCMU_DEV(dev);
2449        char *orig, *ptr, *opts;
2450        substring_t args[MAX_OPT_ARGS];
2451        int ret = 0, token;
2452
2453        opts = kstrdup(page, GFP_KERNEL);
2454        if (!opts)
2455                return -ENOMEM;
2456
2457        orig = opts;
2458
2459        while ((ptr = strsep(&opts, ",\n")) != NULL) {
2460                if (!*ptr)
2461                        continue;
2462
2463                token = match_token(ptr, tokens, args);
2464                switch (token) {
2465                case Opt_dev_config:
2466                        if (match_strlcpy(udev->dev_config, &args[0],
2467                                          TCMU_CONFIG_LEN) == 0) {
2468                                ret = -EINVAL;
2469                                break;
2470                        }
2471                        pr_debug("TCMU: Referencing Path: %s\n", udev->dev_config);
2472                        break;
2473                case Opt_dev_size:
2474                        ret = match_u64(&args[0], &udev->dev_size);
2475                        if (ret < 0)
2476                                pr_err("match_u64() failed for dev_size=. Error %d.\n",
2477                                       ret);
2478                        break;
2479                case Opt_hw_block_size:
2480                        ret = tcmu_set_dev_attrib(&args[0],
2481                                        &(dev->dev_attrib.hw_block_size));
2482                        break;
2483                case Opt_hw_max_sectors:
2484                        ret = tcmu_set_dev_attrib(&args[0],
2485                                        &(dev->dev_attrib.hw_max_sectors));
2486                        break;
2487                case Opt_nl_reply_supported:
2488                        ret = match_int(&args[0], &udev->nl_reply_supported);
2489                        if (ret < 0)
2490                                pr_err("match_int() failed for nl_reply_supported=. Error %d.\n",
2491                                       ret);
2492                        break;
2493                case Opt_max_data_area_mb:
2494                        ret = tcmu_set_max_blocks_param(udev, &args[0]);
2495                        break;
2496                case Opt_data_pages_per_blk:
2497                        ret = tcmu_set_data_pages_per_blk(udev, &args[0]);
2498                        break;
2499                default:
2500                        break;
2501                }
2502
2503                if (ret)
2504                        break;
2505        }
2506
2507        kfree(orig);
2508        return (!ret) ? count : ret;
2509}
2510
2511static ssize_t tcmu_show_configfs_dev_params(struct se_device *dev, char *b)
2512{
2513        struct tcmu_dev *udev = TCMU_DEV(dev);
2514        ssize_t bl = 0;
2515
2516        bl = sprintf(b + bl, "Config: %s ",
2517                     udev->dev_config[0] ? udev->dev_config : "NULL");
2518        bl += sprintf(b + bl, "Size: %llu ", udev->dev_size);
2519        bl += sprintf(b + bl, "MaxDataAreaMB: %u ", udev->data_area_mb);
2520        bl += sprintf(b + bl, "DataPagesPerBlk: %u\n", udev->data_pages_per_blk);
2521
2522        return bl;
2523}
2524
2525static sector_t tcmu_get_blocks(struct se_device *dev)
2526{
2527        struct tcmu_dev *udev = TCMU_DEV(dev);
2528
2529        return div_u64(udev->dev_size - dev->dev_attrib.block_size,
2530                       dev->dev_attrib.block_size);
2531}
2532
2533static sense_reason_t
2534tcmu_parse_cdb(struct se_cmd *cmd)
2535{
2536        return passthrough_parse_cdb(cmd, tcmu_queue_cmd);
2537}
2538
2539static ssize_t tcmu_cmd_time_out_show(struct config_item *item, char *page)
2540{
2541        struct se_dev_attrib *da = container_of(to_config_group(item),
2542                                        struct se_dev_attrib, da_group);
2543        struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2544
2545        return snprintf(page, PAGE_SIZE, "%lu\n", udev->cmd_time_out / MSEC_PER_SEC);
2546}
2547
2548static ssize_t tcmu_cmd_time_out_store(struct config_item *item, const char *page,
2549                                       size_t count)
2550{
2551        struct se_dev_attrib *da = container_of(to_config_group(item),
2552                                        struct se_dev_attrib, da_group);
2553        struct tcmu_dev *udev = container_of(da->da_dev,
2554                                        struct tcmu_dev, se_dev);
2555        u32 val;
2556        int ret;
2557
2558        if (da->da_dev->export_count) {
2559                pr_err("Unable to set tcmu cmd_time_out while exports exist\n");
2560                return -EINVAL;
2561        }
2562
2563        ret = kstrtou32(page, 0, &val);
2564        if (ret < 0)
2565                return ret;
2566
2567        udev->cmd_time_out = val * MSEC_PER_SEC;
2568        return count;
2569}
2570CONFIGFS_ATTR(tcmu_, cmd_time_out);
2571
2572static ssize_t tcmu_qfull_time_out_show(struct config_item *item, char *page)
2573{
2574        struct se_dev_attrib *da = container_of(to_config_group(item),
2575                                                struct se_dev_attrib, da_group);
2576        struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2577
2578        return snprintf(page, PAGE_SIZE, "%ld\n", udev->qfull_time_out <= 0 ?
2579                        udev->qfull_time_out :
2580                        udev->qfull_time_out / MSEC_PER_SEC);
2581}
2582
2583static ssize_t tcmu_qfull_time_out_store(struct config_item *item,
2584                                         const char *page, size_t count)
2585{
2586        struct se_dev_attrib *da = container_of(to_config_group(item),
2587                                        struct se_dev_attrib, da_group);
2588        struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2589        s32 val;
2590        int ret;
2591
2592        ret = kstrtos32(page, 0, &val);
2593        if (ret < 0)
2594                return ret;
2595
2596        if (val >= 0) {
2597                udev->qfull_time_out = val * MSEC_PER_SEC;
2598        } else if (val == -1) {
2599                udev->qfull_time_out = val;
2600        } else {
2601                printk(KERN_ERR "Invalid qfull timeout value %d\n", val);
2602                return -EINVAL;
2603        }
2604        return count;
2605}
2606CONFIGFS_ATTR(tcmu_, qfull_time_out);
2607
2608static ssize_t tcmu_max_data_area_mb_show(struct config_item *item, char *page)
2609{
2610        struct se_dev_attrib *da = container_of(to_config_group(item),
2611                                                struct se_dev_attrib, da_group);
2612        struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2613
2614        return snprintf(page, PAGE_SIZE, "%u\n", udev->data_area_mb);
2615}
2616CONFIGFS_ATTR_RO(tcmu_, max_data_area_mb);
2617
2618static ssize_t tcmu_data_pages_per_blk_show(struct config_item *item,
2619                                            char *page)
2620{
2621        struct se_dev_attrib *da = container_of(to_config_group(item),
2622                                                struct se_dev_attrib, da_group);
2623        struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2624
2625        return snprintf(page, PAGE_SIZE, "%u\n", udev->data_pages_per_blk);
2626}
2627CONFIGFS_ATTR_RO(tcmu_, data_pages_per_blk);
2628
2629static ssize_t tcmu_dev_config_show(struct config_item *item, char *page)
2630{
2631        struct se_dev_attrib *da = container_of(to_config_group(item),
2632                                                struct se_dev_attrib, da_group);
2633        struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2634
2635        return snprintf(page, PAGE_SIZE, "%s\n", udev->dev_config);
2636}
2637
2638static int tcmu_send_dev_config_event(struct tcmu_dev *udev,
2639                                      const char *reconfig_data)
2640{
2641        struct sk_buff *skb = NULL;
2642        void *msg_header = NULL;
2643        int ret = 0;
2644
2645        ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2646                                      &skb, &msg_header);
2647        if (ret < 0)
2648                return ret;
2649        ret = nla_put_string(skb, TCMU_ATTR_DEV_CFG, reconfig_data);
2650        if (ret < 0) {
2651                nlmsg_free(skb);
2652                return ret;
2653        }
2654        return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2655                                       skb, msg_header);
2656}
2657
2658
2659static ssize_t tcmu_dev_config_store(struct config_item *item, const char *page,
2660                                     size_t count)
2661{
2662        struct se_dev_attrib *da = container_of(to_config_group(item),
2663                                                struct se_dev_attrib, da_group);
2664        struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2665        int ret, len;
2666
2667        len = strlen(page);
2668        if (!len || len > TCMU_CONFIG_LEN - 1)
2669                return -EINVAL;
2670
2671        /* Check if device has been configured before */
2672        if (target_dev_configured(&udev->se_dev)) {
2673                ret = tcmu_send_dev_config_event(udev, page);
2674                if (ret) {
2675                        pr_err("Unable to reconfigure device\n");
2676                        return ret;
2677                }
2678                strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2679
2680                ret = tcmu_update_uio_info(udev);
2681                if (ret)
2682                        return ret;
2683                return count;
2684        }
2685        strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2686
2687        return count;
2688}
2689CONFIGFS_ATTR(tcmu_, dev_config);
2690
2691static ssize_t tcmu_dev_size_show(struct config_item *item, char *page)
2692{
2693        struct se_dev_attrib *da = container_of(to_config_group(item),
2694                                                struct se_dev_attrib, da_group);
2695        struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2696
2697        return snprintf(page, PAGE_SIZE, "%llu\n", udev->dev_size);
2698}
2699
2700static int tcmu_send_dev_size_event(struct tcmu_dev *udev, u64 size)
2701{
2702        struct sk_buff *skb = NULL;
2703        void *msg_header = NULL;
2704        int ret = 0;
2705
2706        ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2707                                      &skb, &msg_header);
2708        if (ret < 0)
2709                return ret;
2710        ret = nla_put_u64_64bit(skb, TCMU_ATTR_DEV_SIZE,
2711                                size, TCMU_ATTR_PAD);
2712        if (ret < 0) {
2713                nlmsg_free(skb);
2714                return ret;
2715        }
2716        return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2717                                       skb, msg_header);
2718}
2719
2720static ssize_t tcmu_dev_size_store(struct config_item *item, const char *page,
2721                                   size_t count)
2722{
2723        struct se_dev_attrib *da = container_of(to_config_group(item),
2724                                                struct se_dev_attrib, da_group);
2725        struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2726        u64 val;
2727        int ret;
2728
2729        ret = kstrtou64(page, 0, &val);
2730        if (ret < 0)
2731                return ret;
2732
2733        /* Check if device has been configured before */
2734        if (target_dev_configured(&udev->se_dev)) {
2735                ret = tcmu_send_dev_size_event(udev, val);
2736                if (ret) {
2737                        pr_err("Unable to reconfigure device\n");
2738                        return ret;
2739                }
2740        }
2741        udev->dev_size = val;
2742        return count;
2743}
2744CONFIGFS_ATTR(tcmu_, dev_size);
2745
2746static ssize_t tcmu_nl_reply_supported_show(struct config_item *item,
2747                char *page)
2748{
2749        struct se_dev_attrib *da = container_of(to_config_group(item),
2750                                                struct se_dev_attrib, da_group);
2751        struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2752
2753        return snprintf(page, PAGE_SIZE, "%d\n", udev->nl_reply_supported);
2754}
2755
2756static ssize_t tcmu_nl_reply_supported_store(struct config_item *item,
2757                const char *page, size_t count)
2758{
2759        struct se_dev_attrib *da = container_of(to_config_group(item),
2760                                                struct se_dev_attrib, da_group);
2761        struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2762        s8 val;
2763        int ret;
2764
2765        ret = kstrtos8(page, 0, &val);
2766        if (ret < 0)
2767                return ret;
2768
2769        udev->nl_reply_supported = val;
2770        return count;
2771}
2772CONFIGFS_ATTR(tcmu_, nl_reply_supported);
2773
2774static ssize_t tcmu_emulate_write_cache_show(struct config_item *item,
2775                                             char *page)
2776{
2777        struct se_dev_attrib *da = container_of(to_config_group(item),
2778                                        struct se_dev_attrib, da_group);
2779
2780        return snprintf(page, PAGE_SIZE, "%i\n", da->emulate_write_cache);
2781}
2782
2783static int tcmu_send_emulate_write_cache(struct tcmu_dev *udev, u8 val)
2784{
2785        struct sk_buff *skb = NULL;
2786        void *msg_header = NULL;
2787        int ret = 0;
2788
2789        ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2790                                      &skb, &msg_header);
2791        if (ret < 0)
2792                return ret;
2793        ret = nla_put_u8(skb, TCMU_ATTR_WRITECACHE, val);
2794        if (ret < 0) {
2795                nlmsg_free(skb);
2796                return ret;
2797        }
2798        return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2799                                       skb, msg_header);
2800}
2801
2802static ssize_t tcmu_emulate_write_cache_store(struct config_item *item,
2803                                              const char *page, size_t count)
2804{
2805        struct se_dev_attrib *da = container_of(to_config_group(item),
2806                                        struct se_dev_attrib, da_group);
2807        struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2808        u8 val;
2809        int ret;
2810
2811        ret = kstrtou8(page, 0, &val);
2812        if (ret < 0)
2813                return ret;
2814
2815        /* Check if device has been configured before */
2816        if (target_dev_configured(&udev->se_dev)) {
2817                ret = tcmu_send_emulate_write_cache(udev, val);
2818                if (ret) {
2819                        pr_err("Unable to reconfigure device\n");
2820                        return ret;
2821                }
2822        }
2823
2824        da->emulate_write_cache = val;
2825        return count;
2826}
2827CONFIGFS_ATTR(tcmu_, emulate_write_cache);
2828
2829static ssize_t tcmu_tmr_notification_show(struct config_item *item, char *page)
2830{
2831        struct se_dev_attrib *da = container_of(to_config_group(item),
2832                                        struct se_dev_attrib, da_group);
2833        struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2834
2835        return snprintf(page, PAGE_SIZE, "%i\n",
2836                        test_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags));
2837}
2838
2839static ssize_t tcmu_tmr_notification_store(struct config_item *item,
2840                                           const char *page, size_t count)
2841{
2842        struct se_dev_attrib *da = container_of(to_config_group(item),
2843                                        struct se_dev_attrib, da_group);
2844        struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2845        u8 val;
2846        int ret;
2847
2848        ret = kstrtou8(page, 0, &val);
2849        if (ret < 0)
2850                return ret;
2851        if (val > 1)
2852                return -EINVAL;
2853
2854        if (val)
2855                set_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags);
2856        else
2857                clear_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags);
2858        return count;
2859}
2860CONFIGFS_ATTR(tcmu_, tmr_notification);
2861
2862static ssize_t tcmu_block_dev_show(struct config_item *item, char *page)
2863{
2864        struct se_device *se_dev = container_of(to_config_group(item),
2865                                                struct se_device,
2866                                                dev_action_group);
2867        struct tcmu_dev *udev = TCMU_DEV(se_dev);
2868
2869        if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
2870                return snprintf(page, PAGE_SIZE, "%s\n", "blocked");
2871        else
2872                return snprintf(page, PAGE_SIZE, "%s\n", "unblocked");
2873}
2874
2875static ssize_t tcmu_block_dev_store(struct config_item *item, const char *page,
2876                                    size_t count)
2877{
2878        struct se_device *se_dev = container_of(to_config_group(item),
2879                                                struct se_device,
2880                                                dev_action_group);
2881        struct tcmu_dev *udev = TCMU_DEV(se_dev);
2882        u8 val;
2883        int ret;
2884
2885        if (!target_dev_configured(&udev->se_dev)) {
2886                pr_err("Device is not configured.\n");
2887                return -EINVAL;
2888        }
2889
2890        ret = kstrtou8(page, 0, &val);
2891        if (ret < 0)
2892                return ret;
2893
2894        if (val > 1) {
2895                pr_err("Invalid block value %d\n", val);
2896                return -EINVAL;
2897        }
2898
2899        if (!val)
2900                tcmu_unblock_dev(udev);
2901        else
2902                tcmu_block_dev(udev);
2903        return count;
2904}
2905CONFIGFS_ATTR(tcmu_, block_dev);
2906
2907static ssize_t tcmu_reset_ring_store(struct config_item *item, const char *page,
2908                                     size_t count)
2909{
2910        struct se_device *se_dev = container_of(to_config_group(item),
2911                                                struct se_device,
2912                                                dev_action_group);
2913        struct tcmu_dev *udev = TCMU_DEV(se_dev);
2914        u8 val;
2915        int ret;
2916
2917        if (!target_dev_configured(&udev->se_dev)) {
2918                pr_err("Device is not configured.\n");
2919                return -EINVAL;
2920        }
2921
2922        ret = kstrtou8(page, 0, &val);
2923        if (ret < 0)
2924                return ret;
2925
2926        if (val != 1 && val != 2) {
2927                pr_err("Invalid reset ring value %d\n", val);
2928                return -EINVAL;
2929        }
2930
2931        tcmu_reset_ring(udev, val);
2932        return count;
2933}
2934CONFIGFS_ATTR_WO(tcmu_, reset_ring);
2935
2936static struct configfs_attribute *tcmu_attrib_attrs[] = {
2937        &tcmu_attr_cmd_time_out,
2938        &tcmu_attr_qfull_time_out,
2939        &tcmu_attr_max_data_area_mb,
2940        &tcmu_attr_data_pages_per_blk,
2941        &tcmu_attr_dev_config,
2942        &tcmu_attr_dev_size,
2943        &tcmu_attr_emulate_write_cache,
2944        &tcmu_attr_tmr_notification,
2945        &tcmu_attr_nl_reply_supported,
2946        NULL,
2947};
2948
2949static struct configfs_attribute **tcmu_attrs;
2950
2951static struct configfs_attribute *tcmu_action_attrs[] = {
2952        &tcmu_attr_block_dev,
2953        &tcmu_attr_reset_ring,
2954        NULL,
2955};
2956
2957static struct target_backend_ops tcmu_ops = {
2958        .name                   = "user",
2959        .owner                  = THIS_MODULE,
2960        .transport_flags_default = TRANSPORT_FLAG_PASSTHROUGH,
2961        .transport_flags_changeable = TRANSPORT_FLAG_PASSTHROUGH_PGR |
2962                                      TRANSPORT_FLAG_PASSTHROUGH_ALUA,
2963        .attach_hba             = tcmu_attach_hba,
2964        .detach_hba             = tcmu_detach_hba,
2965        .alloc_device           = tcmu_alloc_device,
2966        .configure_device       = tcmu_configure_device,
2967        .destroy_device         = tcmu_destroy_device,
2968        .free_device            = tcmu_free_device,
2969        .unplug_device          = tcmu_unplug_device,
2970        .plug_device            = tcmu_plug_device,
2971        .parse_cdb              = tcmu_parse_cdb,
2972        .tmr_notify             = tcmu_tmr_notify,
2973        .set_configfs_dev_params = tcmu_set_configfs_dev_params,
2974        .show_configfs_dev_params = tcmu_show_configfs_dev_params,
2975        .get_device_type        = sbc_get_device_type,
2976        .get_blocks             = tcmu_get_blocks,
2977        .tb_dev_action_attrs    = tcmu_action_attrs,
2978};
2979
2980static void find_free_blocks(void)
2981{
2982        struct tcmu_dev *udev;
2983        loff_t off;
2984        u32 pages_freed, total_pages_freed = 0;
2985        u32 start, end, block, total_blocks_freed = 0;
2986
2987        if (atomic_read(&global_page_count) <= tcmu_global_max_pages)
2988                return;
2989
2990        mutex_lock(&root_udev_mutex);
2991        list_for_each_entry(udev, &root_udev, node) {
2992                mutex_lock(&udev->cmdr_lock);
2993
2994                if (!target_dev_configured(&udev->se_dev)) {
2995                        mutex_unlock(&udev->cmdr_lock);
2996                        continue;
2997                }
2998
2999                /* Try to complete the finished commands first */
3000                if (tcmu_handle_completions(udev))
3001                        run_qfull_queue(udev, false);
3002
3003                /* Skip the udevs in idle */
3004                if (!udev->dbi_thresh) {
3005                        mutex_unlock(&udev->cmdr_lock);
3006                        continue;
3007                }
3008
3009                end = udev->dbi_max + 1;
3010                block = find_last_bit(udev->data_bitmap, end);
3011                if (block == udev->dbi_max) {
3012                        /*
3013                         * The last bit is dbi_max, so it is not possible
3014                         * reclaim any blocks.
3015                         */
3016                        mutex_unlock(&udev->cmdr_lock);
3017                        continue;
3018                } else if (block == end) {
3019                        /* The current udev will goto idle state */
3020                        udev->dbi_thresh = start = 0;
3021                        udev->dbi_max = 0;
3022                } else {
3023                        udev->dbi_thresh = start = block + 1;
3024                        udev->dbi_max = block;
3025                }
3026
3027                /* Here will truncate the data area from off */
3028                off = udev->data_off + (loff_t)start * udev->data_blk_size;
3029                unmap_mapping_range(udev->inode->i_mapping, off, 0, 1);
3030
3031                /* Release the block pages */
3032                pages_freed = tcmu_blocks_release(udev, start, end - 1);
3033                mutex_unlock(&udev->cmdr_lock);
3034
3035                total_pages_freed += pages_freed;
3036                total_blocks_freed += end - start;
3037                pr_debug("Freed %u pages (total %u) from %u blocks (total %u) from %s.\n",
3038                         pages_freed, total_pages_freed, end - start,
3039                         total_blocks_freed, udev->name);
3040        }
3041        mutex_unlock(&root_udev_mutex);
3042
3043        if (atomic_read(&global_page_count) > tcmu_global_max_pages)
3044                schedule_delayed_work(&tcmu_unmap_work, msecs_to_jiffies(5000));
3045}
3046
3047static void check_timedout_devices(void)
3048{
3049        struct tcmu_dev *udev, *tmp_dev;
3050        struct tcmu_cmd *cmd, *tmp_cmd;
3051        LIST_HEAD(devs);
3052
3053        spin_lock_bh(&timed_out_udevs_lock);
3054        list_splice_init(&timed_out_udevs, &devs);
3055
3056        list_for_each_entry_safe(udev, tmp_dev, &devs, timedout_entry) {
3057                list_del_init(&udev->timedout_entry);
3058                spin_unlock_bh(&timed_out_udevs_lock);
3059
3060                mutex_lock(&udev->cmdr_lock);
3061
3062                /*
3063                 * If cmd_time_out is disabled but qfull is set deadline
3064                 * will only reflect the qfull timeout. Ignore it.
3065                 */
3066                if (udev->cmd_time_out) {
3067                        list_for_each_entry_safe(cmd, tmp_cmd,
3068                                                 &udev->inflight_queue,
3069                                                 queue_entry) {
3070                                tcmu_check_expired_ring_cmd(cmd);
3071                        }
3072                        tcmu_set_next_deadline(&udev->inflight_queue,
3073                                               &udev->cmd_timer);
3074                }
3075                list_for_each_entry_safe(cmd, tmp_cmd, &udev->qfull_queue,
3076                                         queue_entry) {
3077                        tcmu_check_expired_queue_cmd(cmd);
3078                }
3079                tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
3080
3081                mutex_unlock(&udev->cmdr_lock);
3082
3083                spin_lock_bh(&timed_out_udevs_lock);
3084        }
3085
3086        spin_unlock_bh(&timed_out_udevs_lock);
3087}
3088
3089static void tcmu_unmap_work_fn(struct work_struct *work)
3090{
3091        check_timedout_devices();
3092        find_free_blocks();
3093}
3094
3095static int __init tcmu_module_init(void)
3096{
3097        int ret, i, k, len = 0;
3098
3099        BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry) % TCMU_OP_ALIGN_SIZE) != 0);
3100
3101        INIT_DELAYED_WORK(&tcmu_unmap_work, tcmu_unmap_work_fn);
3102
3103        tcmu_cmd_cache = kmem_cache_create("tcmu_cmd_cache",
3104                                sizeof(struct tcmu_cmd),
3105                                __alignof__(struct tcmu_cmd),
3106                                0, NULL);
3107        if (!tcmu_cmd_cache)
3108                return -ENOMEM;
3109
3110        tcmu_root_device = root_device_register("tcm_user");
3111        if (IS_ERR(tcmu_root_device)) {
3112                ret = PTR_ERR(tcmu_root_device);
3113                goto out_free_cache;
3114        }
3115
3116        ret = genl_register_family(&tcmu_genl_family);
3117        if (ret < 0) {
3118                goto out_unreg_device;
3119        }
3120
3121        for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
3122                len += sizeof(struct configfs_attribute *);
3123        for (i = 0; passthrough_pr_attrib_attrs[i] != NULL; i++)
3124                len += sizeof(struct configfs_attribute *);
3125        for (i = 0; tcmu_attrib_attrs[i] != NULL; i++)
3126                len += sizeof(struct configfs_attribute *);
3127        len += sizeof(struct configfs_attribute *);
3128
3129        tcmu_attrs = kzalloc(len, GFP_KERNEL);
3130        if (!tcmu_attrs) {
3131                ret = -ENOMEM;
3132                goto out_unreg_genl;
3133        }
3134
3135        for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
3136                tcmu_attrs[i] = passthrough_attrib_attrs[i];
3137        for (k = 0; passthrough_pr_attrib_attrs[k] != NULL; k++)
3138                tcmu_attrs[i++] = passthrough_pr_attrib_attrs[k];
3139        for (k = 0; tcmu_attrib_attrs[k] != NULL; k++)
3140                tcmu_attrs[i++] = tcmu_attrib_attrs[k];
3141        tcmu_ops.tb_dev_attrib_attrs = tcmu_attrs;
3142
3143        ret = transport_backend_register(&tcmu_ops);
3144        if (ret)
3145                goto out_attrs;
3146
3147        return 0;
3148
3149out_attrs:
3150        kfree(tcmu_attrs);
3151out_unreg_genl:
3152        genl_unregister_family(&tcmu_genl_family);
3153out_unreg_device:
3154        root_device_unregister(tcmu_root_device);
3155out_free_cache:
3156        kmem_cache_destroy(tcmu_cmd_cache);
3157
3158        return ret;
3159}
3160
3161static void __exit tcmu_module_exit(void)
3162{
3163        cancel_delayed_work_sync(&tcmu_unmap_work);
3164        target_backend_unregister(&tcmu_ops);
3165        kfree(tcmu_attrs);
3166        genl_unregister_family(&tcmu_genl_family);
3167        root_device_unregister(tcmu_root_device);
3168        kmem_cache_destroy(tcmu_cmd_cache);
3169}
3170
3171MODULE_DESCRIPTION("TCM USER subsystem plugin");
3172MODULE_AUTHOR("Shaohua Li <shli@kernel.org>");
3173MODULE_AUTHOR("Andy Grover <agrover@redhat.com>");
3174MODULE_LICENSE("GPL");
3175
3176module_init(tcmu_module_init);
3177module_exit(tcmu_module_exit);
3178