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 TCMU_DEV_BIT_PLUGGED 4
 125	unsigned long flags;
 126
 127	struct uio_info uio_info;
 128
 129	struct inode *inode;
 130
 131	uint64_t dev_size;
 132
 133	struct tcmu_mailbox *mb_addr;
 134	void *cmdr;
 135	u32 cmdr_size;
 136	u32 cmdr_last_cleaned;
 137	/* Offset of data area from start of mb */
 138	/* Must add data_off and mb_addr to get the address */
 139	size_t data_off;
 140	int data_area_mb;
 141	uint32_t max_blocks;
 142	size_t mmap_pages;
 143
 144	struct mutex cmdr_lock;
 145	struct list_head qfull_queue;
 146	struct list_head tmr_queue;
 147
 148	uint32_t dbi_max;
 149	uint32_t dbi_thresh;
 150	unsigned long *data_bitmap;
 151	struct xarray data_pages;
 152	uint32_t data_pages_per_blk;
 153	uint32_t data_blk_size;
 154
 155	struct xarray commands;
 156
 157	struct timer_list cmd_timer;
 158	unsigned int cmd_time_out;
 159	struct list_head inflight_queue;
 160
 161	struct timer_list qfull_timer;
 162	int qfull_time_out;
 163
 164	struct list_head timedout_entry;
 165
 166	struct tcmu_nl_cmd curr_nl_cmd;
 167
 168	char dev_config[TCMU_CONFIG_LEN];
 169
 170	int nl_reply_supported;
 171};
 172
 173#define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev)
 174
 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(TCMU_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(TCMU_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(TCMU_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 false;
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);