1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) 2013 Shaohua Li <shli@kernel.org>
   4 * Copyright (C) 2014 Red Hat, Inc.
   5 * Copyright (C) 2015 Arrikto, Inc.
   6 * Copyright (C) 2017 Chinamobile, Inc.
   7 */
   8
   9#include <linux/spinlock.h>
  10#include <linux/module.h>
  11#include <linux/kernel.h>
  12#include <linux/timer.h>
  13#include <linux/parser.h>
  14#include <linux/vmalloc.h>
  15#include <linux/uio_driver.h>
  16#include <linux/xarray.h>
  17#include <linux/stringify.h>
  18#include <linux/bitops.h>
  19#include <linux/highmem.h>
  20#include <linux/configfs.h>
  21#include <linux/mutex.h>
  22#include <linux/workqueue.h>
  23#include <linux/pagemap.h>
  24#include <net/genetlink.h>
  25#include <scsi/scsi_common.h>
  26#include <scsi/scsi_proto.h>
  27#include <target/target_core_base.h>
  28#include <target/target_core_fabric.h>
  29#include <target/target_core_backend.h>
  30
  31#include <linux/target_core_user.h>
  32
  33/**
  34 * DOC: Userspace I/O
  35 * Userspace I/O
  36 * -------------
  37 *
  38 * Define a shared-memory interface for LIO to pass SCSI commands and
  39 * data to userspace for processing. This is to allow backends that
  40 * are too complex for in-kernel support to be possible.
  41 *
  42 * It uses the UIO framework to do a lot of the device-creation and
  43 * introspection work for us.
  44 *
  45 * See the .h file for how the ring is laid out. Note that while the
  46 * command ring is defined, the particulars of the data area are
  47 * not. Offset values in the command entry point to other locations
  48 * internal to the mmap-ed area. There is separate space outside the
  49 * command ring for data buffers. This leaves maximum flexibility for
  50 * moving buffer allocations, or even page flipping or other
  51 * allocation techniques, without altering the command ring layout.
  52 *
  53 * SECURITY:
  54 * The user process must be assumed to be malicious. There's no way to
  55 * prevent it breaking the command ring protocol if it wants, but in
  56 * order to prevent other issues we must only ever read *data* from
  57 * the shared memory area, not offsets or sizes. This applies to
  58 * command ring entries as well as the mailbox. Extra code needed for
  59 * this may have a 'UAM' comment.
  60 */
  61
  62#define TCMU_TIME_OUT (30 * MSEC_PER_SEC)
  63
  64/* For mailbox plus cmd ring, the size is fixed 8MB */
  65#define MB_CMDR_SIZE_DEF (8 * 1024 * 1024)
  66/* Offset of cmd ring is size of mailbox */
  67#define CMDR_OFF ((__u32)sizeof(struct tcmu_mailbox))
  68#define CMDR_SIZE_DEF (MB_CMDR_SIZE_DEF - CMDR_OFF)
  69
  70/*
  71 * For data area, the default block size is PAGE_SIZE and
  72 * the default total size is 256K * PAGE_SIZE.
  73 */
  74#define DATA_PAGES_PER_BLK_DEF 1
  75#define DATA_AREA_PAGES_DEF (256 * 1024)
  76
  77#define TCMU_MBS_TO_PAGES(_mbs) ((size_t)_mbs << (20 - PAGE_SHIFT))
  78#define TCMU_PAGES_TO_MBS(_pages) (_pages >> (20 - PAGE_SHIFT))
  79
  80/*
  81 * Default number of global data blocks(512K * PAGE_SIZE)
  82 * when the unmap thread will be started.
  83 */
  84#define TCMU_GLOBAL_MAX_PAGES_DEF (512 * 1024)
  85
  86static u8 tcmu_kern_cmd_reply_supported;
  87static u8 tcmu_netlink_blocked;
  88
  89static struct device *tcmu_root_device;
  90
  91struct tcmu_hba {
  92	u32 host_id;
  93};
  94
  95#define TCMU_CONFIG_LEN 256
  96
  97static DEFINE_MUTEX(tcmu_nl_cmd_mutex);
  98static LIST_HEAD(tcmu_nl_cmd_list);
  99
 100struct tcmu_dev;
 101
 102struct tcmu_nl_cmd {
 103	/* wake up thread waiting for reply */
 104	struct completion complete;
 105	struct list_head nl_list;
 106	struct tcmu_dev *udev;
 107	int cmd;
 108	int status;
 109};
 110
 111struct tcmu_dev {
 112	struct list_head node;
 113	struct kref kref;
 114
 115	struct se_device se_dev;
 116	struct se_dev_plug se_plug;
 117
 118	char *name;
 119	struct se_hba *hba;
 120
 121#define TCMU_DEV_BIT_OPEN 0
 122#define TCMU_DEV_BIT_BROKEN 1
 123#define TCMU_DEV_BIT_BLOCKED 2
 124#define TCMU_DEV_BIT_TMR_NOTIFY 3
 125#define TCMU_DEV_BIT_PLUGGED 4
 126	unsigned long flags;
 127
 128	struct uio_info uio_info;
 129
 130	struct inode *inode;
 131
 132	uint64_t dev_size;
 133
 134	struct tcmu_mailbox *mb_addr;
 135	void *cmdr;
 136	u32 cmdr_size;
 137	u32 cmdr_last_cleaned;
 138	/* Offset of data area from start of mb */
 139	/* Must add data_off and mb_addr to get the address */
 140	size_t data_off;
 141	int data_area_mb;
 142	uint32_t max_blocks;
 143	size_t mmap_pages;
 144
 145	struct mutex cmdr_lock;
 146	struct list_head qfull_queue;
 147	struct list_head tmr_queue;
 148
 149	uint32_t dbi_max;
 150	uint32_t dbi_thresh;
 151	unsigned long *data_bitmap;
 152	struct xarray data_pages;
 153	uint32_t data_pages_per_blk;
 154	uint32_t data_blk_size;
 155
 156	struct xarray commands;
 157
 158	struct timer_list cmd_timer;
 159	unsigned int cmd_time_out;
 160	struct list_head inflight_queue;
 161
 162	struct timer_list qfull_timer;
 163	int qfull_time_out;
 164
 165	struct list_head timedout_entry;
 166
 167	struct tcmu_nl_cmd curr_nl_cmd;
 168
 169	char dev_config[TCMU_CONFIG_LEN];
 170
 171	int nl_reply_supported;
 172};
 173
 174#define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev)
 175
 176struct tcmu_cmd {
 177	struct se_cmd *se_cmd;
 178	struct tcmu_dev *tcmu_dev;
 179	struct list_head queue_entry;
 180
 181	uint16_t cmd_id;
 182
 183	/* Can't use se_cmd when cleaning up expired cmds, because if
 184	   cmd has been completed then accessing se_cmd is off limits */
 185	uint32_t dbi_cnt;
 186	uint32_t dbi_bidi_cnt;
 187	uint32_t dbi_cur;
 188	uint32_t *dbi;
 189
 190	uint32_t data_len_bidi;
 191
 192	unsigned long deadline;
 193
 194#define TCMU_CMD_BIT_EXPIRED 0
 195#define TCMU_CMD_BIT_KEEP_BUF 1
 196	unsigned long flags;
 197};
 198
 199struct tcmu_tmr {
 200	struct list_head queue_entry;
 201
 202	uint8_t tmr_type;
 203	uint32_t tmr_cmd_cnt;
 204	int16_t tmr_cmd_ids[] __counted_by(tmr_cmd_cnt);
 205};
 206
 207/*
 208 * To avoid dead lock the mutex lock order should always be:
 209 *
 210 * mutex_lock(&root_udev_mutex);
 211 * ...
 212 * mutex_lock(&tcmu_dev->cmdr_lock);
 213 * mutex_unlock(&tcmu_dev->cmdr_lock);
 214 * ...
 215 * mutex_unlock(&root_udev_mutex);
 216 */
 217static DEFINE_MUTEX(root_udev_mutex);
 218static LIST_HEAD(root_udev);
 219
 220static DEFINE_SPINLOCK(timed_out_udevs_lock);
 221static LIST_HEAD(timed_out_udevs);
 222
 223static struct kmem_cache *tcmu_cmd_cache;
 224
 225static atomic_t global_page_count = ATOMIC_INIT(0);
 226static struct delayed_work tcmu_unmap_work;
 227static int tcmu_global_max_pages = TCMU_GLOBAL_MAX_PAGES_DEF;
 228
 229static int tcmu_set_global_max_data_area(const char *str,
 230					 const struct kernel_param *kp)
 231{
 232	int ret, max_area_mb;
 233
 234	ret = kstrtoint(str, 10, &max_area_mb);
 235	if (ret)
 236		return -EINVAL;
 237
 238	if (max_area_mb <= 0) {
 239		pr_err("global_max_data_area must be larger than 0.\n");
 240		return -EINVAL;
 241	}
 242
 243	tcmu_global_max_pages = TCMU_MBS_TO_PAGES(max_area_mb);
 244	if (atomic_read(&global_page_count) > tcmu_global_max_pages)
 245		schedule_delayed_work(&tcmu_unmap_work, 0);
 246	else
 247		cancel_delayed_work_sync(&tcmu_unmap_work);
 248
 249	return 0;
 250}
 251
 252static int tcmu_get_global_max_data_area(char *buffer,
 253					 const struct kernel_param *kp)
 254{
 255	return sprintf(buffer, "%d\n", TCMU_PAGES_TO_MBS(tcmu_global_max_pages));
 256}
 257
 258static const struct kernel_param_ops tcmu_global_max_data_area_op = {
 259	.set = tcmu_set_global_max_data_area,
 260	.get = tcmu_get_global_max_data_area,
 261};
 262
 263module_param_cb(global_max_data_area_mb, &tcmu_global_max_data_area_op, NULL,
 264		S_IWUSR | S_IRUGO);
 265MODULE_PARM_DESC(global_max_data_area_mb,
 266		 "Max MBs allowed to be allocated to all the tcmu device's "
 267		 "data areas.");
 268
 269static int tcmu_get_block_netlink(char *buffer,
 270				  const struct kernel_param *kp)
 271{
 272	return sprintf(buffer, "%s\n", tcmu_netlink_blocked ?
 273		       "blocked" : "unblocked");
 274}
 275
 276static int tcmu_set_block_netlink(const char *str,
 277				  const struct kernel_param *kp)
 278{
 279	int ret;
 280	u8 val;
 281
 282	ret = kstrtou8(str, 0, &val);
 283	if (ret < 0)
 284		return ret;
 285
 286	if (val > 1) {
 287		pr_err("Invalid block netlink value %u\n", val);
 288		return -EINVAL;
 289	}
 290
 291	tcmu_netlink_blocked = val;
 292	return 0;
 293}
 294
 295static const struct kernel_param_ops tcmu_block_netlink_op = {
 296	.set = tcmu_set_block_netlink,
 297	.get = tcmu_get_block_netlink,
 298};
 299
 300module_param_cb(block_netlink, &tcmu_block_netlink_op, NULL, S_IWUSR | S_IRUGO);
 301MODULE_PARM_DESC(block_netlink, "Block new netlink commands.");
 302
 303static int tcmu_fail_netlink_cmd(struct tcmu_nl_cmd *nl_cmd)
 304{
 305	struct tcmu_dev *udev = nl_cmd->udev;
 306
 307	if (!tcmu_netlink_blocked) {
 308		pr_err("Could not reset device's netlink interface. Netlink is not blocked.\n");
 309		return -EBUSY;
 310	}
 311
 312	if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
 313		pr_debug("Aborting nl cmd %d on %s\n", nl_cmd->cmd, udev->name);
 314		nl_cmd->status = -EINTR;
 315		list_del(&nl_cmd->nl_list);
 316		complete(&nl_cmd->complete);
 317	}
 318	return 0;
 319}
 320
 321static int tcmu_set_reset_netlink(const char *str,
 322				  const struct kernel_param *kp)
 323{
 324	struct tcmu_nl_cmd *nl_cmd, *tmp_cmd;
 325	int ret;
 326	u8 val;
 327
 328	ret = kstrtou8(str, 0, &val);
 329	if (ret < 0)
 330		return ret;
 331
 332	if (val != 1) {
 333		pr_err("Invalid reset netlink value %u\n", val);
 334		return -EINVAL;
 335	}
 336
 337	mutex_lock(&tcmu_nl_cmd_mutex);
 338	list_for_each_entry_safe(nl_cmd, tmp_cmd, &tcmu_nl_cmd_list, nl_list) {
 339		ret = tcmu_fail_netlink_cmd(nl_cmd);
 340		if (ret)
 341			break;
 342	}
 343	mutex_unlock(&tcmu_nl_cmd_mutex);
 344
 345	return ret;
 346}
 347
 348static const struct kernel_param_ops tcmu_reset_netlink_op = {
 349	.set = tcmu_set_reset_netlink,
 350};
 351
 352module_param_cb(reset_netlink, &tcmu_reset_netlink_op, NULL, S_IWUSR);
 353MODULE_PARM_DESC(reset_netlink, "Reset netlink commands.");
 354
 355/* multicast group */
 356enum tcmu_multicast_groups {
 357	TCMU_MCGRP_CONFIG,
 358};
 359
 360static const struct genl_multicast_group tcmu_mcgrps[] = {
 361	[TCMU_MCGRP_CONFIG] = { .name = "config", },
 362};
 363
 364static const struct nla_policy tcmu_attr_policy[TCMU_ATTR_MAX + 1] = {
 365	[TCMU_ATTR_DEVICE]	= { .type = NLA_STRING },
 366	[TCMU_ATTR_MINOR]	= { .type = NLA_U32 },
 367	[TCMU_ATTR_CMD_STATUS]	= { .type = NLA_S32 },
 368	[TCMU_ATTR_DEVICE_ID]	= { .type = NLA_U32 },
 369	[TCMU_ATTR_SUPP_KERN_CMD_REPLY] = { .type = NLA_U8 },
 370};
 371
 372static int tcmu_genl_cmd_done(struct genl_info *info, int completed_cmd)
 373{
 374	struct tcmu_dev *udev = NULL;
 375	struct tcmu_nl_cmd *nl_cmd;
 376	int dev_id, rc, ret = 0;
 377
 378	if (!info->attrs[TCMU_ATTR_CMD_STATUS] ||
 379	    !info->attrs[TCMU_ATTR_DEVICE_ID]) {
 380		printk(KERN_ERR "TCMU_ATTR_CMD_STATUS or TCMU_ATTR_DEVICE_ID not set, doing nothing\n");
 381		return -EINVAL;
 382        }
 383
 384	dev_id = nla_get_u32(info->attrs[TCMU_ATTR_DEVICE_ID]);
 385	rc = nla_get_s32(info->attrs[TCMU_ATTR_CMD_STATUS]);
 386
 387	mutex_lock(&tcmu_nl_cmd_mutex);
 388	list_for_each_entry(nl_cmd, &tcmu_nl_cmd_list, nl_list) {
 389		if (nl_cmd->udev->se_dev.dev_index == dev_id) {
 390			udev = nl_cmd->udev;
 391			break;
 392		}
 393	}
 394
 395	if (!udev) {
 396		pr_err("tcmu nl cmd %u/%d completion could not find device with dev id %u.\n",
 397		       completed_cmd, rc, dev_id);
 398		ret = -ENODEV;
 399		goto unlock;
 400	}
 401	list_del(&nl_cmd->nl_list);
 402
 403	pr_debug("%s genl cmd done got id %d curr %d done %d rc %d stat %d\n",
 404		 udev->name, dev_id, nl_cmd->cmd, completed_cmd, rc,
 405		 nl_cmd->status);
 406
 407	if (nl_cmd->cmd != completed_cmd) {
 408		pr_err("Mismatched commands on %s (Expecting reply for %d. Current %d).\n",
 409		       udev->name, completed_cmd, nl_cmd->cmd);
 410		ret = -EINVAL;
 411		goto unlock;
 412	}
 413
 414	nl_cmd->status = rc;
 415	complete(&nl_cmd->complete);
 416unlock:
 417	mutex_unlock(&tcmu_nl_cmd_mutex);
 418	return ret;
 419}
 420
 421static int tcmu_genl_rm_dev_done(struct sk_buff *skb, struct genl_info *info)
 422{
 423	return tcmu_genl_cmd_done(info, TCMU_CMD_REMOVED_DEVICE);
 424}
 425
 426static int tcmu_genl_add_dev_done(struct sk_buff *skb, struct genl_info *info)
 427{
 428	return tcmu_genl_cmd_done(info, TCMU_CMD_ADDED_DEVICE);
 429}
 430
 431static int tcmu_genl_reconfig_dev_done(struct sk_buff *skb,
 432				       struct genl_info *info)
 433{
 434	return tcmu_genl_cmd_done(info, TCMU_CMD_RECONFIG_DEVICE);
 435}
 436
 437static int tcmu_genl_set_features(struct sk_buff *skb, struct genl_info *info)
 438{
 439	if (info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]) {
 440		tcmu_kern_cmd_reply_supported  =
 441			nla_get_u8(info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]);
 442		printk(KERN_INFO "tcmu daemon: command reply support %u.\n",
 443		       tcmu_kern_cmd_reply_supported);
 444	}
 445
 446	return 0;
 447}
 448
 449static const struct genl_small_ops tcmu_genl_ops[] = {
 450	{
 451		.cmd	= TCMU_CMD_SET_FEATURES,
 452		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 453		.flags	= GENL_ADMIN_PERM,
 454		.doit	= tcmu_genl_set_features,
 455	},
 456	{
 457		.cmd	= TCMU_CMD_ADDED_DEVICE_DONE,
 458		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 459		.flags	= GENL_ADMIN_PERM,
 460		.doit	= tcmu_genl_add_dev_done,
 461	},
 462	{
 463		.cmd	= TCMU_CMD_REMOVED_DEVICE_DONE,
 464		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 465		.flags	= GENL_ADMIN_PERM,
 466		.doit	= tcmu_genl_rm_dev_done,
 467	},
 468	{
 469		.cmd	= TCMU_CMD_RECONFIG_DEVICE_DONE,
 470		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 471		.flags	= GENL_ADMIN_PERM,
 472		.doit	= tcmu_genl_reconfig_dev_done,
 473	},
 474};
 475
 476/* Our generic netlink family */
 477static struct genl_family tcmu_genl_family __ro_after_init = {
 478	.module = THIS_MODULE,
 479	.hdrsize = 0,
 480	.name = "TCM-USER",
 481	.version = 2,
 482	.maxattr = TCMU_ATTR_MAX,
 483	.policy = tcmu_attr_policy,
 484	.mcgrps = tcmu_mcgrps,
 485	.n_mcgrps = ARRAY_SIZE(tcmu_mcgrps),
 486	.netnsok = true,
 487	.small_ops = tcmu_genl_ops,
 488	.n_small_ops = ARRAY_SIZE(tcmu_genl_ops),
 489	.resv_start_op = TCMU_CMD_SET_FEATURES + 1,
 490};
 491
 492#define tcmu_cmd_set_dbi_cur(cmd, index) ((cmd)->dbi_cur = (index))
 493#define tcmu_cmd_reset_dbi_cur(cmd) tcmu_cmd_set_dbi_cur(cmd, 0)
 494#define tcmu_cmd_set_dbi(cmd, index) ((cmd)->dbi[(cmd)->dbi_cur++] = (index))
 495#define tcmu_cmd_get_dbi(cmd) ((cmd)->dbi[(cmd)->dbi_cur++])
 496
 497static void tcmu_cmd_free_data(struct tcmu_cmd *tcmu_cmd, uint32_t len)
 498{
 499	struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
 500	uint32_t i;
 501
 502	for (i = 0; i < len; i++)
 503		clear_bit(tcmu_cmd->dbi[i], udev->data_bitmap);
 504}
 505
 506static inline int tcmu_get_empty_block(struct tcmu_dev *udev,
 507				       struct tcmu_cmd *tcmu_cmd,
 508				       int prev_dbi, int length, int *iov_cnt)
 509{
 510	XA_STATE(xas, &udev->data_pages, 0);
 511	struct page *page;
 512	int i, cnt, dbi, dpi;
 513	int page_cnt = DIV_ROUND_UP(length, PAGE_SIZE);
 514
 515	dbi = find_first_zero_bit(udev->data_bitmap, udev->dbi_thresh);
 516	if (dbi == udev->dbi_thresh)
 517		return -1;
 518
 519	dpi = dbi * udev->data_pages_per_blk;
 520	/* Count the number of already allocated pages */
 521	xas_set(&xas, dpi);
 522	rcu_read_lock();
 523	for (cnt = 0; xas_next(&xas) && cnt < page_cnt;)
 524		cnt++;
 525	rcu_read_unlock();
 526
 527	for (i = cnt; i < page_cnt; i++) {
 528		/* try to get new zeroed page from the mm */
 529		page = alloc_page(GFP_NOIO | __GFP_ZERO);
 530		if (!page)
 531			break;
 532
 533		if (xa_store(&udev->data_pages, dpi + i, page, GFP_NOIO)) {
 534			__free_page(page);
 535			break;
 536		}
 537	}
 538	if (atomic_add_return(i - cnt, &global_page_count) >
 539			      tcmu_global_max_pages)
 540		schedule_delayed_work(&tcmu_unmap_work, 0);
 541
 542	if (i && dbi > udev->dbi_max)
 543		udev->dbi_max = dbi;
 544
 545	set_bit(dbi, udev->data_bitmap);
 546	tcmu_cmd_set_dbi(tcmu_cmd, dbi);
 547
 548	if (dbi != prev_dbi + 1)
 549		*iov_cnt += 1;
 550
 551	return i == page_cnt ? dbi : -1;
 552}
 553
 554static int tcmu_get_empty_blocks(struct tcmu_dev *udev,
 555				 struct tcmu_cmd *tcmu_cmd, int length)
 556{
 557	/* start value of dbi + 1 must not be a valid dbi */
 558	int dbi = -2;
 559	int blk_data_len, iov_cnt = 0;
 560	uint32_t blk_size = udev->data_blk_size;
 561
 562	for (; length > 0; length -= blk_size) {
 563		blk_data_len = min_t(uint32_t, length, blk_size);
 564		dbi = tcmu_get_empty_block(udev, tcmu_cmd, dbi, blk_data_len,
 565					   &iov_cnt);
 566		if (dbi < 0)
 567			return -1;
 568	}
 569	return iov_cnt;
 570}
 571
 572static inline void tcmu_free_cmd(struct tcmu_cmd *tcmu_cmd)
 573{
 574	kfree(tcmu_cmd->dbi);
 575	kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
 576}
 577
 578static inline void tcmu_cmd_set_block_cnts(struct tcmu_cmd *cmd)
 579{
 580	int i, len;
 581	struct se_cmd *se_cmd = cmd->se_cmd;
 582	uint32_t blk_size = cmd->tcmu_dev->data_blk_size;
 583
 584	cmd->dbi_cnt = DIV_ROUND_UP(se_cmd->data_length, blk_size);
 585
 586	if (se_cmd->se_cmd_flags & SCF_BIDI) {
 587		BUG_ON(!(se_cmd->t_bidi_data_sg && se_cmd->t_bidi_data_nents));
 588		for (i = 0, len = 0; i < se_cmd->t_bidi_data_nents; i++)
 589			len += se_cmd->t_bidi_data_sg[i].length;
 590		cmd->dbi_bidi_cnt = DIV_ROUND_UP(len, blk_size);
 591		cmd->dbi_cnt += cmd->dbi_bidi_cnt;
 592		cmd->data_len_bidi = len;
 593	}
 594}
 595
 596static int new_block_to_iov(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
 597			    struct iovec **iov, int prev_dbi, int len)
 598{
 599	/* Get the next dbi */
 600	int dbi = tcmu_cmd_get_dbi(cmd);
 601
 602	/* Do not add more than udev->data_blk_size to iov */
 603	len = min_t(int,  len, udev->data_blk_size);
 604
 605	/*
 606	 * The following code will gather and map the blocks to the same iovec
 607	 * when the blocks are all next to each other.
 608	 */
 609	if (dbi != prev_dbi + 1) {
 610		/* dbi is not next to previous dbi, so start new iov */
 611		if (prev_dbi >= 0)
 612			(*iov)++;
 613		/* write offset relative to mb_addr */
 614		(*iov)->iov_base = (void __user *)
 615				   (udev->data_off + dbi * udev->data_blk_size);
 616	}
 617	(*iov)->iov_len += len;
 618
 619	return dbi;
 620}
 621
 622static void tcmu_setup_iovs(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
 623			    struct iovec **iov, int data_length)
 624{
 625	/* start value of dbi + 1 must not be a valid dbi */
 626	int dbi = -2;
 627
 628	/* We prepare the IOVs for DMA_FROM_DEVICE transfer direction */
 629	for (; data_length > 0; data_length -= udev->data_blk_size)
 630		dbi = new_block_to_iov(udev, cmd, iov, dbi, data_length);
 631}
 632
 633static struct tcmu_cmd *tcmu_alloc_cmd(struct se_cmd *se_cmd)
 634{
 635	struct se_device *se_dev = se_cmd->se_dev;
 636	struct tcmu_dev *udev = TCMU_DEV(se_dev);
 637	struct tcmu_cmd *tcmu_cmd;
 638
 639	tcmu_cmd = kmem_cache_zalloc(tcmu_cmd_cache, GFP_NOIO);
 640	if (!tcmu_cmd)
 641		return NULL;
 642
 643	INIT_LIST_HEAD(&tcmu_cmd->queue_entry);
 644	tcmu_cmd->se_cmd = se_cmd;
 645	tcmu_cmd->tcmu_dev = udev;
 646
 647	tcmu_cmd_set_block_cnts(tcmu_cmd);
 648	tcmu_cmd->dbi = kcalloc(tcmu_cmd->dbi_cnt, sizeof(uint32_t),
 649				GFP_NOIO);
 650	if (!tcmu_cmd->dbi) {
 651		kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
 652		return NULL;
 653	}
 654
 655	return tcmu_cmd;
 656}
 657
 658static inline void tcmu_flush_dcache_range(void *vaddr, size_t size)
 659{
 660	unsigned long offset = offset_in_page(vaddr);
 661	void *start = vaddr - offset;
 662
 663	size = round_up(size+offset, PAGE_SIZE);
 664
 665	while (size) {
 666		flush_dcache_page(vmalloc_to_page(start));
 667		start += PAGE_SIZE;
 668		size -= PAGE_SIZE;
 669	}
 670}
 671
 672/*
 673 * Some ring helper functions. We don't assume size is a power of 2 so
 674 * we can't use circ_buf.h.
 675 */
 676static inline size_t spc_used(size_t head, size_t tail, size_t size)
 677{
 678	int diff = head - tail;
 679
 680	if (diff >= 0)
 681		return diff;
 682	else
 683		return size + diff;
 684}
 685
 686static inline size_t spc_free(size_t head, size_t tail, size_t size)
 687{
 688	/* Keep 1 byte unused or we can't tell full from empty */
 689	return (size - spc_used(head, tail, size) - 1);
 690}
 691
 692static inline size_t head_to_end(size_t head, size_t size)
 693{
 694	return size - head;
 695}
 696
 697#define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size)
 698
 699#define TCMU_SG_TO_DATA_AREA 1
 700#define TCMU_DATA_AREA_TO_SG 2
 701
 702static inline void tcmu_copy_data(struct tcmu_dev *udev,
 703				  struct tcmu_cmd *tcmu_cmd, uint32_t direction,
 704				  struct scatterlist *sg, unsigned int sg_nents,
 705				  struct iovec **iov, size_t data_len)
 706{
 707	/* start value of dbi + 1 must not be a valid dbi */
 708	int dbi = -2;
 709	size_t page_remaining, cp_len;
 710	int page_cnt, page_inx, dpi;
 711	struct sg_mapping_iter sg_iter;
 712	unsigned int sg_flags;
 713	struct page *page;
 714	void *data_page_start, *data_addr;
 715
 716	if (direction == TCMU_SG_TO_DATA_AREA)
 717		sg_flags = SG_MITER_ATOMIC | SG_MITER_FROM_SG;
 718	else
 719		sg_flags = SG_MITER_ATOMIC | SG_MITER_TO_SG;
 720	sg_miter_start(&sg_iter, sg, sg_nents, sg_flags);
 721
 722	while (data_len) {
 723		if (direction == TCMU_SG_TO_DATA_AREA)
 724			dbi = new_block_to_iov(udev, tcmu_cmd, iov, dbi,
 725					       data_len);
 726		else
 727			dbi = tcmu_cmd_get_dbi(tcmu_cmd);
 728
 729		page_cnt = DIV_ROUND_UP(data_len, PAGE_SIZE);
 730		if (page_cnt > udev->data_pages_per_blk)
 731			page_cnt = udev->data_pages_per_blk;
 732
 733		dpi = dbi * udev->data_pages_per_blk;
 734		for (page_inx = 0; page_inx < page_cnt && data_len;
 735		     page_inx++, dpi++) {
 736			page = xa_load(&udev->data_pages, dpi);
 737
 738			if (direction == TCMU_DATA_AREA_TO_SG)
 739				flush_dcache_page(page);
 740			data_page_start = kmap_atomic(page);
 741			page_remaining = PAGE_SIZE;
 742
 743			while (page_remaining && data_len) {
 744				if (!sg_miter_next(&sg_iter)) {
 745					/* set length to 0 to abort outer loop */
 746					data_len = 0;
 747					pr_debug("%s: aborting data copy due to exhausted sg_list\n",
 748						 __func__);
 749					break;
 750				}
 751				cp_len = min3(sg_iter.length, page_remaining,
 752					      data_len);
 753
 754				data_addr = data_page_start +
 755					    PAGE_SIZE - page_remaining;
 756				if (direction == TCMU_SG_TO_DATA_AREA)
 757					memcpy(data_addr, sg_iter.addr, cp_len);
 758				else
 759					memcpy(sg_iter.addr, data_addr, cp_len);
 760
 761				data_len -= cp_len;
 762				page_remaining -= cp_len;
 763				sg_iter.consumed = cp_len;
 764			}
 765			sg_miter_stop(&sg_iter);
 766
 767			kunmap_atomic(data_page_start);
 768			if (direction == TCMU_SG_TO_DATA_AREA)
 769				flush_dcache_page(page);
 770		}
 771	}
 772}
 773
 774static void scatter_data_area(struct tcmu_dev *udev, struct tcmu_cmd *tcmu_cmd,
 775			      struct iovec **iov)
 776{
 777	struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
 778
 779	tcmu_copy_data(udev, tcmu_cmd, TCMU_SG_TO_DATA_AREA, se_cmd->t_data_sg,
 780		       se_cmd->t_data_nents, iov, se_cmd->data_length);
 781}
 782
 783static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *tcmu_cmd,
 784			     bool bidi, uint32_t read_len)
 785{
 786	struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
 787	struct scatterlist *data_sg;
 788	unsigned int data_nents;
 789
 790	if (!bidi) {
 791		data_sg = se_cmd->t_data_sg;
 792		data_nents = se_cmd->t_data_nents;
 793	} else {
 794		/*
 795		 * For bidi case, the first count blocks are for Data-Out
 796		 * buffer blocks, and before gathering the Data-In buffer
 797		 * the Data-Out buffer blocks should be skipped.
 798		 */
 799		tcmu_cmd_set_dbi_cur(tcmu_cmd,
 800				     tcmu_cmd->dbi_cnt - tcmu_cmd->dbi_bidi_cnt);
 801
 802		data_sg = se_cmd->t_bidi_data_sg;
 803		data_nents = se_cmd->t_bidi_data_nents;
 804	}
 805
 806	tcmu_copy_data(udev, tcmu_cmd, TCMU_DATA_AREA_TO_SG, data_sg,
 807		       data_nents, NULL, read_len);
 808}
 809
 810static inline size_t spc_bitmap_free(unsigned long *bitmap, uint32_t thresh)
 811{
 812	return thresh - bitmap_weight(bitmap, thresh);
 813}
 814
 815/*
 816 * We can't queue a command until we have space available on the cmd ring.
 817 *
 818 * Called with ring lock held.
 819 */
 820static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size)
 821{
 822	struct tcmu_mailbox *mb = udev->mb_addr;
 823	size_t space, cmd_needed;
 824	u32 cmd_head;
 825
 826	tcmu_flush_dcache_range(mb, sizeof(*mb));
 827
 828	cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
 829
 830	/*
 831	 * If cmd end-of-ring space is too small then we need space for a NOP plus
 832	 * original cmd - cmds are internally contiguous.
 833	 */
 834	if (head_to_end(cmd_head, udev->cmdr_size) >= cmd_size)
 835		cmd_needed = cmd_size;
 836	else
 837		cmd_needed = cmd_size + head_to_end(cmd_head, udev->cmdr_size);
 838
 839	space = spc_free(cmd_head, udev->cmdr_last_cleaned, udev->cmdr_size);
 840	if (space < cmd_needed) {
 841		pr_debug("no cmd space: %u %u %u\n", cmd_head,
 842		       udev->cmdr_last_cleaned, udev->cmdr_size);
 843		return false;
 844	}
 845	return true;
 846}
 847
 848/*
 849 * We have to allocate data buffers before we can queue a command.
 850 * Returns -1 on error (not enough space) or number of needed iovs on success
 851 *
 852 * Called with ring lock held.
 853 */
 854static int tcmu_alloc_data_space(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
 855				  int *iov_bidi_cnt)
 856{
 857	int space, iov_cnt = 0, ret = 0;
 858
 859	if (!cmd->dbi_cnt)
 860		goto wr_iov_cnts;
 861
 862	/* try to check and get the data blocks as needed */
 863	space = spc_bitmap_free(udev->data_bitmap, udev->dbi_thresh);
 864	if (space < cmd->dbi_cnt) {
 865		unsigned long blocks_left =
 866				(udev->max_blocks - udev->dbi_thresh) + space;
 867
 868		if (blocks_left < cmd->dbi_cnt) {
 869			pr_debug("no data space: only %lu available, but ask for %u\n",
 870					blocks_left * udev->data_blk_size,
 871					cmd->dbi_cnt * udev->data_blk_size);
 872			return -1;
 873		}
 874
 875		udev->dbi_thresh += cmd->dbi_cnt;
 876		if (udev->dbi_thresh > udev->max_blocks)
 877			udev->dbi_thresh = udev->max_blocks;
 878	}
 879
 880	iov_cnt = tcmu_get_empty_blocks(udev, cmd, cmd->se_cmd->data_length);
 881	if (iov_cnt < 0)
 882		return -1;
 883
 884	if (cmd->dbi_bidi_cnt) {
 885		ret = tcmu_get_empty_blocks(udev, cmd, cmd->data_len_bidi);
 886		if (ret < 0)
 887			return -1;
 888	}
 889wr_iov_cnts:
 890	*iov_bidi_cnt = ret;
 891	return iov_cnt + ret;
 892}
 893
 894static inline size_t tcmu_cmd_get_base_cmd_size(size_t iov_cnt)
 895{
 896	return max(offsetof(struct tcmu_cmd_entry, req.iov[iov_cnt]),
 897			sizeof(struct tcmu_cmd_entry));
 898}
 899
 900static inline size_t tcmu_cmd_get_cmd_size(struct tcmu_cmd *tcmu_cmd,
 901					   size_t base_command_size)
 902{
 903	struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
 904	size_t command_size;
 905
 906	command_size = base_command_size +
 907		round_up(scsi_command_size(se_cmd->t_task_cdb),
 908				TCMU_OP_ALIGN_SIZE);
 909
 910	WARN_ON(command_size & (TCMU_OP_ALIGN_SIZE-1));
 911
 912	return command_size;
 913}
 914
 915static void tcmu_setup_cmd_timer(struct tcmu_cmd *tcmu_cmd, unsigned int tmo,
 916				 struct timer_list *timer)
 917{
 918	if (!tmo)
 919		return;
 920
 921	tcmu_cmd->deadline = round_jiffies_up(jiffies + msecs_to_jiffies(tmo));
 922	if (!timer_pending(timer))
 923		mod_timer(timer, tcmu_cmd->deadline);
 924
 925	pr_debug("Timeout set up for cmd %p, dev = %s, tmo = %lu\n", tcmu_cmd,
 926		 tcmu_cmd->tcmu_dev->name, tmo / MSEC_PER_SEC);
 927}
 928
 929static int add_to_qfull_queue(struct tcmu_cmd *tcmu_cmd)
 930{
 931	struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
 932	unsigned int tmo;
 933
 934	/*
 935	 * For backwards compat if qfull_time_out is not set use
 936	 * cmd_time_out and if that's not set use the default time out.
 937	 */
 938	if (!udev->qfull_time_out)
 939		return -ETIMEDOUT;
 940	else if (udev->qfull_time_out > 0)
 941		tmo = udev->qfull_time_out;
 942	else if (udev->cmd_time_out)
 943		tmo = udev->cmd_time_out;
 944	else
 945		tmo = TCMU_TIME_OUT;
 946
 947	tcmu_setup_cmd_timer(tcmu_cmd, tmo, &udev->qfull_timer);
 948
 949	list_add_tail(&tcmu_cmd->queue_entry, &udev->qfull_queue);
 950	pr_debug("adding cmd %p on dev %s to ring space wait queue\n",
 951		 tcmu_cmd, udev->name);
 952	return 0;
 953}
 954
 955static uint32_t ring_insert_padding(struct tcmu_dev *udev, size_t cmd_size)
 956{
 957	struct tcmu_cmd_entry_hdr *hdr;
 958	struct tcmu_mailbox *mb = udev->mb_addr;
 959	uint32_t cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
 960
 961	/* Insert a PAD if end-of-ring space is too small */
 962	if (head_to_end(cmd_head, udev->cmdr_size) < cmd_size) {
 963		size_t pad_size = head_to_end(cmd_head, udev->cmdr_size);
 964
 965		hdr = udev->cmdr + cmd_head;
 966		tcmu_hdr_set_op(&hdr->len_op, TCMU_OP_PAD);
 967		tcmu_hdr_set_len(&hdr->len_op, pad_size);
 968		hdr->cmd_id = 0; /* not used for PAD */
 969		hdr->kflags = 0;
 970		hdr->uflags = 0;
 971		tcmu_flush_dcache_range(hdr, sizeof(*hdr));
 972
 973		UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size);
 974		tcmu_flush_dcache_range(mb, sizeof(*mb));
 975
 976		cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
 977		WARN_ON(cmd_head != 0);
 978	}
 979
 980	return cmd_head;
 981}
 982
 983static void tcmu_unplug_device(struct se_dev_plug *se_plug)
 984{
 985	struct se_device *se_dev = se_plug->se_dev;
 986	struct tcmu_dev *udev = TCMU_DEV(se_dev);
 987
 988	clear_bit(TCMU_DEV_BIT_PLUGGED, &udev->flags);
 989	uio_event_notify(&udev->uio_info);
 990}
 991
 992static struct se_dev_plug *tcmu_plug_device(struct se_device *se_dev)
 993{
 994	struct tcmu_dev *udev = TCMU_DEV(se_dev);
 995
 996	if (!test_and_set_bit(TCMU_DEV_BIT_PLUGGED, &udev->flags))
 997		return &udev->se_plug;
 998
 999	return NULL;
1000}
1001
1002/**
1003 * queue_cmd_ring - queue cmd to ring or internally
1004 * @tcmu_cmd: cmd to queue
1005 * @scsi_err: TCM error code if failure (-1) returned.
1006 *
1007 * Returns:
1008 * -1 we cannot queue internally or to the ring.
1009 *  0 success
1010 *  1 internally queued to wait for ring memory to free.
1011 */
1012static int queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, sense_reason_t *scsi_err)
1013{
1014	struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
1015	struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
1016	size_t base_command_size, command_size;
1017	struct tcmu_mailbox *mb = udev->mb_addr;
1018	struct tcmu_cmd_entry *entry;
1019	struct iovec *iov;
1020	int iov_cnt, iov_bidi_cnt;
1021	uint32_t cmd_id, cmd_head;
1022	uint64_t cdb_off;
1023	uint32_t blk_size = udev->data_blk_size;
1024	/* size of data buffer needed */
1025	size_t data_length = (size_t)tcmu_cmd->dbi_cnt * blk_size;
1026
1027	*scsi_err = TCM_NO_SENSE;
1028
1029	if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags)) {
1030		*scsi_err = TCM_LUN_BUSY;
1031		return -1;
1032	}
1033
1034	if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
1035		*scsi_err = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1036		return -1;
1037	}
1038
1039	if (!list_empty(&udev->qfull_queue))
1040		goto queue;
1041
1042	if (data_length > (size_t)udev->max_blocks * blk_size) {
1043		pr_warn("TCMU: Request of size %zu is too big for %zu data area\n",
1044			data_length, (size_t)udev->max_blocks * blk_size);
1045		*scsi_err = TCM_INVALID_CDB_FIELD;
1046		return -1;
1047	}
1048
1049	iov_cnt = tcmu_alloc_data_space(udev, tcmu_cmd, &iov_bidi_cnt);
1050	if (iov_cnt < 0)
1051		goto free_and_queue;
1052
1053	/*
1054	 * Must be a certain minimum size for response sense info, but
1055	 * also may be larger if the iov array is large.
1056	 */
1057	base_command_size = tcmu_cmd_get_base_cmd_size(iov_cnt);
1058	command_size = tcmu_cmd_get_cmd_size(tcmu_cmd, base_command_size);
1059
1060	if (command_size > (udev->cmdr_size / 2)) {
1061		pr_warn("TCMU: Request of size %zu is too big for %u cmd ring\n",
1062			command_size, udev->cmdr_size);
1063		tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cur);
1064		*scsi_err = TCM_INVALID_CDB_FIELD;
1065		return -1;
1066	}
1067
1068	if (!is_ring_space_avail(udev, command_size))
1069		/*
1070		 * Don't leave commands partially setup because the unmap
1071		 * thread might need the blocks to make forward progress.
1072		 */
1073		goto free_and_queue;
1074
1075	if (xa_alloc(&udev->commands, &cmd_id, tcmu_cmd, XA_LIMIT(1, 0xffff),
1076		     GFP_NOWAIT) < 0) {
1077		pr_err("tcmu: Could not allocate cmd id.\n");
1078
1079		tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cnt);
1080		*scsi_err = TCM_OUT_OF_RESOURCES;
1081		return -1;
1082	}
1083	tcmu_cmd->cmd_id = cmd_id;
1084
1085	pr_debug("allocated cmd id %u for cmd %p dev %s\n", tcmu_cmd->cmd_id,
1086		 tcmu_cmd, udev->name);
1087
1088	cmd_head = ring_insert_padding(udev, command_size);
1089
1090	entry = udev->cmdr + cmd_head;
1091	memset(entry, 0, command_size);
1092	tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_CMD);
1093
1094	/* prepare iov list and copy data to data area if necessary */
1095	tcmu_cmd_reset_dbi_cur(tcmu_cmd);
1096	iov = &entry->req.iov[0];
1097
1098	if (se_cmd->data_direction == DMA_TO_DEVICE ||
1099	    se_cmd->se_cmd_flags & SCF_BIDI)
1100		scatter_data_area(udev, tcmu_cmd, &iov);
1101	else
1102		tcmu_setup_iovs(udev, tcmu_cmd, &iov, se_cmd->data_length);
1103
1104	entry->req.iov_cnt = iov_cnt - iov_bidi_cnt;
1105
1106	/* Handle BIDI commands */
1107	if (se_cmd->se_cmd_flags & SCF_BIDI) {
1108		iov++;
1109		tcmu_setup_iovs(udev, tcmu_cmd, &iov, tcmu_cmd->data_len_bidi);
1110		entry->req.iov_bidi_cnt = iov_bidi_cnt;
1111	}
1112
1113	tcmu_setup_cmd_timer(tcmu_cmd, udev->cmd_time_out, &udev->cmd_timer);
1114
1115	entry->hdr.cmd_id = tcmu_cmd->cmd_id;
1116
1117	tcmu_hdr_set_len(&entry->hdr.len_op, command_size);
1118
1119	/* All offsets relative to mb_addr, not start of entry! */
1120	cdb_off = CMDR_OFF + cmd_head + base_command_size;
1121	memcpy((void *) mb + cdb_off, se_cmd->t_task_cdb, scsi_command_size(se_cmd->t_task_cdb));
1122	entry->req.cdb_off = cdb_off;
1123	tcmu_flush_dcache_range(entry, command_size);
1124
1125	UPDATE_HEAD(mb->cmd_head, command_size, udev->cmdr_size);
1126	tcmu_flush_dcache_range(mb, sizeof(*mb));
1127
1128	list_add_tail(&tcmu_cmd->queue_entry, &udev->inflight_queue);
1129
1130	if (!test_bit(TCMU_DEV_BIT_PLUGGED, &udev->flags))
1131		uio_event_notify(&udev->uio_info);
1132
1133	return 0;
1134
1135free_and_queue:
1136	tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cur);
1137	tcmu_cmd_reset_dbi_cur(tcmu_cmd);
1138
1139queue:
1140	if (add_to_qfull_queue(tcmu_cmd)) {
1141		*scsi_err = TCM_OUT_OF_RESOURCES;
1142		return -1;
1143	}
1144
1145	return 1;
1146}
1147
1148/**
1149 * queue_tmr_ring - queue tmr info to ring or internally
1150 * @udev: related tcmu_dev
1151 * @tmr: tcmu_tmr containing tmr info to queue
1152 *
1153 * Returns:
1154 *  0 success
1155 *  1 internally queued to wait for ring memory to free.
1156 */
1157static int
1158queue_tmr_ring(struct tcmu_dev *udev, struct tcmu_tmr *tmr)
1159{
1160	struct tcmu_tmr_entry *entry;
1161	int cmd_size;
1162	int id_list_sz;
1163	struct tcmu_mailbox *mb = udev->mb_addr;
1164	uint32_t cmd_head;
1165
1166	if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags))
1167		goto out_free;
1168
1169	id_list_sz = sizeof(tmr->tmr_cmd_ids[0]) * tmr->tmr_cmd_cnt;
1170	cmd_size = round_up(sizeof(*entry) + id_list_sz, TCMU_OP_ALIGN_SIZE);
1171
1172	if (!list_empty(&udev->tmr_queue) ||
1173	    !is_ring_space_avail(udev, cmd_size)) {
1174		list_add_tail(&tmr->queue_entry, &udev->tmr_queue);
1175		pr_debug("adding tmr %p on dev %s to TMR ring space wait queue\n",
1176			 tmr, udev->name);
1177		return 1;
1178	}
1179
1180	cmd_head = ring_insert_padding(udev, cmd_size);
1181
1182	entry = udev->cmdr + cmd_head;
1183	memset(entry, 0, cmd_size);
1184	tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_TMR);
1185	tcmu_hdr_set_len(&entry->hdr.len_op, cmd_size);
1186	entry->tmr_type = tmr->tmr_type;
1187	entry->cmd_cnt = tmr->tmr_cmd_cnt;
1188	memcpy(&entry->cmd_ids[0], &tmr->tmr_cmd_ids[0], id_list_sz);
1189	tcmu_flush_dcache_range(entry, cmd_size);
1190
1191	UPDATE_HEAD(mb->cmd_head, cmd_size, udev->cmdr_size);
1192	tcmu_flush_dcache_range(mb, sizeof(*mb));
1193
1194	uio_event_notify(&udev->uio_info);
1195
1196out_free:
1197	kfree(tmr);
1198
1199	return 0;
1200}
1201
1202static sense_reason_t
1203tcmu_queue_cmd(struct se_cmd *se_cmd)
1204{
1205	struct se_device *se_dev = se_cmd->se_dev;
1206	struct tcmu_dev *udev = TCMU_DEV(se_dev);
1207	struct tcmu_cmd *tcmu_cmd;
1208	sense_reason_t scsi_ret = TCM_CHECK_CONDITION_ABORT_CMD;
1209	int ret = -1;
1210
1211	tcmu_cmd = tcmu_alloc_cmd(se_cmd);
1212	if (!tcmu_cmd)
1213		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1214
1215	mutex_lock(&udev->cmdr_lock);
1216	if (!(se_cmd->transport_state & CMD_T_ABORTED))
1217		ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
1218	if (ret < 0)
1219		tcmu_free_cmd(tcmu_cmd);
1220	else
1221		se_cmd->priv = tcmu_cmd;
1222	mutex_unlock(&udev->cmdr_lock);
1223	return scsi_ret;
1224}
1225
1226static void tcmu_set_next_deadline(struct list_head *queue,
1227				   struct timer_list *timer)
1228{
1229	struct tcmu_cmd *cmd;
1230
1231	if (!list_empty(queue)) {
1232		cmd = list_first_entry(queue, struct tcmu_cmd, queue_entry);
1233		mod_timer(timer, cmd->deadline);
1234	} else
1235		del_timer(timer);
1236}
1237
1238static int
1239tcmu_tmr_type(enum tcm_tmreq_table tmf)
1240{
1241	switch (tmf) {
1242	case TMR_ABORT_TASK:		return TCMU_TMR_ABORT_TASK;
1243	case TMR_ABORT_TASK_SET:	return TCMU_TMR_ABORT_TASK_SET;
1244	case TMR_CLEAR_ACA:		return TCMU_TMR_CLEAR_ACA;
1245	case TMR_CLEAR_TASK_SET:	return TCMU_TMR_CLEAR_TASK_SET;
1246	case TMR_LUN_RESET:		return TCMU_TMR_LUN_RESET;
1247	case TMR_TARGET_WARM_RESET:	return TCMU_TMR_TARGET_WARM_RESET;
1248	case TMR_TARGET_COLD_RESET:	return TCMU_TMR_TARGET_COLD_RESET;
1249	case TMR_LUN_RESET_PRO:		return TCMU_TMR_LUN_RESET_PRO;
1250	default:			return TCMU_TMR_UNKNOWN;
1251	}
1252}
1253
1254static void
1255tcmu_tmr_notify(struct se_device *se_dev, enum tcm_tmreq_table tmf,
1256		struct list_head *cmd_list)
1257{
1258	int i = 0, cmd_cnt = 0;
1259	bool unqueued = false;
 
1260	struct tcmu_cmd *cmd;
1261	struct se_cmd *se_cmd;
1262	struct tcmu_tmr *tmr;
1263	struct tcmu_dev *udev = TCMU_DEV(se_dev);
1264
1265	mutex_lock(&udev->cmdr_lock);
1266
1267	/* First we check for aborted commands in qfull_queue */
1268	list_for_each_entry(se_cmd, cmd_list, state_list) {
1269		i++;
1270		if (!se_cmd->priv)
1271			continue;
1272		cmd = se_cmd->priv;
1273		/* Commands on qfull queue have no id yet */
1274		if (cmd->cmd_id) {
1275			cmd_cnt++;
1276			continue;
1277		}
1278		pr_debug("Removing aborted command %p from queue on dev %s.\n",
1279			 cmd, udev->name);
1280
1281		list_del_init(&cmd->queue_entry);
1282		tcmu_free_cmd(cmd);
1283		se_cmd->priv = NULL;
1284		target_complete_cmd(se_cmd, SAM_STAT_TASK_ABORTED);
1285		unqueued = true;
1286	}
1287	if (unqueued)
1288		tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
1289
1290	if (!test_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags))
1291		goto unlock;
1292
1293	pr_debug("TMR event %d on dev %s, aborted cmds %d, afflicted cmd_ids %d\n",
1294		 tcmu_tmr_type(tmf), udev->name, i, cmd_cnt);
1295
1296	tmr = kmalloc(struct_size(tmr, tmr_cmd_ids, cmd_cnt), GFP_NOIO);
1297	if (!tmr)
1298		goto unlock;
1299
1300	tmr->tmr_type = tcmu_tmr_type(tmf);
1301	tmr->tmr_cmd_cnt = cmd_cnt;
1302
1303	if (cmd_cnt != 0) {
1304		cmd_cnt = 0;
1305		list_for_each_entry(se_cmd, cmd_list, state_list) {
1306			if (!se_cmd->priv)
1307				continue;
1308			cmd = se_cmd->priv;
1309			if (cmd->cmd_id)
1310				tmr->tmr_cmd_ids[cmd_cnt++] = cmd->cmd_id;
1311		}
1312	}
1313
1314	queue_tmr_ring(udev, tmr);
1315
1316unlock:
1317	mutex_unlock(&udev->cmdr_lock);
1318}
1319
1320static bool tcmu_handle_completion(struct tcmu_cmd *cmd,
1321				   struct tcmu_cmd_entry *entry, bool keep_buf)
1322{
1323	struct se_cmd *se_cmd = cmd->se_cmd;
1324	struct tcmu_dev *udev = cmd->tcmu_dev;
1325	bool read_len_valid = false;
1326	bool ret = true;
1327	uint32_t read_len;
1328
1329	/*
1330	 * cmd has been completed already from timeout, just reclaim
1331	 * data area space and free cmd
1332	 */
1333	if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
1334		WARN_ON_ONCE(se_cmd);
1335		goto out;
1336	}
1337	if (test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags)) {
1338		pr_err("cmd_id %u already completed with KEEP_BUF, ring is broken\n",
1339		       entry->hdr.cmd_id);
1340		set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
1341		ret = false;
1342		goto out;
1343	}
1344
1345	list_del_init(&cmd->queue_entry);
1346
1347	tcmu_cmd_reset_dbi_cur(cmd);
1348
1349	if (entry->hdr.uflags & TCMU_UFLAG_UNKNOWN_OP) {
1350		pr_warn("TCMU: Userspace set UNKNOWN_OP flag on se_cmd %p\n",
1351			cmd->se_cmd);
1352		entry->rsp.scsi_status = SAM_STAT_CHECK_CONDITION;
1353		goto done;
1354	}
1355
1356	read_len = se_cmd->data_length;
1357	if (se_cmd->data_direction == DMA_FROM_DEVICE &&
1358	    (entry->hdr.uflags & TCMU_UFLAG_READ_LEN) && entry->rsp.read_len) {
1359		read_len_valid = true;
1360		if (entry->rsp.read_len < read_len)
1361			read_len = entry->rsp.read_len;
1362	}
1363
1364	if (entry->rsp.scsi_status == SAM_STAT_CHECK_CONDITION) {
1365		transport_copy_sense_to_cmd(se_cmd, entry->rsp.sense_buffer);
1366		if (!read_len_valid )
1367			goto done;
1368		else
1369			se_cmd->se_cmd_flags |= SCF_TREAT_READ_AS_NORMAL;
1370	}
1371	if (se_cmd->se_cmd_flags & SCF_BIDI) {
1372		/* Get Data-In buffer before clean up */
1373		gather_data_area(udev, cmd, true, read_len);
1374	} else if (se_cmd->data_direction == DMA_FROM_DEVICE) {
1375		gather_data_area(udev, cmd, false, read_len);
1376	} else if (se_cmd->data_direction == DMA_TO_DEVICE) {
1377		/* TODO: */
1378	} else if (se_cmd->data_direction != DMA_NONE) {
1379		pr_warn("TCMU: data direction was %d!\n",
1380			se_cmd->data_direction);
1381	}
1382
1383done:
1384	se_cmd->priv = NULL;
1385	if (read_len_valid) {
1386		pr_debug("read_len = %d\n", read_len);
1387		target_complete_cmd_with_length(cmd->se_cmd,
1388					entry->rsp.scsi_status, read_len);
1389	} else
1390		target_complete_cmd(cmd->se_cmd, entry->rsp.scsi_status);
1391
1392out:
1393	if (!keep_buf) {
1394		tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
1395		tcmu_free_cmd(cmd);
1396	} else {
1397		/*
1398		 * Keep this command after completion, since userspace still
1399		 * needs the data buffer. Mark it with TCMU_CMD_BIT_KEEP_BUF
1400		 * and reset potential TCMU_CMD_BIT_EXPIRED, so we don't accept
1401		 * a second completion later.
1402		 * Userspace can free the buffer later by writing the cmd_id
1403		 * to new action attribute free_kept_buf.
1404		 */
1405		clear_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags);
1406		set_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags);
1407	}
1408	return ret;
1409}
1410
1411static int tcmu_run_tmr_queue(struct tcmu_dev *udev)
1412{
1413	struct tcmu_tmr *tmr, *tmp;
1414	LIST_HEAD(tmrs);
1415
1416	if (list_empty(&udev->tmr_queue))
1417		return 1;
1418
1419	pr_debug("running %s's tmr queue\n", udev->name);
1420
1421	list_splice_init(&udev->tmr_queue, &tmrs);
1422
1423	list_for_each_entry_safe(tmr, tmp, &tmrs, queue_entry) {
1424		list_del_init(&tmr->queue_entry);
1425
1426		pr_debug("removing tmr %p on dev %s from queue\n",
1427			 tmr, udev->name);
1428
1429		if (queue_tmr_ring(udev, tmr)) {
1430			pr_debug("ran out of space during tmr queue run\n");
1431			/*
1432			 * tmr was requeued, so just put all tmrs back in
1433			 * the queue
1434			 */
1435			list_splice_tail(&tmrs, &udev->tmr_queue);
1436			return 0;
1437		}
1438	}
1439
1440	return 1;
1441}
1442
1443static bool tcmu_handle_completions(struct tcmu_dev *udev)
1444{
1445	struct tcmu_mailbox *mb;
1446	struct tcmu_cmd *cmd;
1447	bool free_space = false;
1448
1449	if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
1450		pr_err("ring broken, not handling completions\n");
1451		return false;
1452	}
1453
1454	mb = udev->mb_addr;
1455	tcmu_flush_dcache_range(mb, sizeof(*mb));
1456
1457	while (udev->cmdr_last_cleaned != READ_ONCE(mb->cmd_tail)) {
1458
1459		struct tcmu_cmd_entry *entry = udev->cmdr + udev->cmdr_last_cleaned;
1460		bool keep_buf;
1461
1462		/*
1463		 * Flush max. up to end of cmd ring since current entry might
1464		 * be a padding that is shorter than sizeof(*entry)
1465		 */
1466		size_t ring_left = head_to_end(udev->cmdr_last_cleaned,
1467					       udev->cmdr_size);
1468		tcmu_flush_dcache_range(entry, ring_left < sizeof(*entry) ?
1469					ring_left : sizeof(*entry));
1470
1471		free_space = true;
1472
1473		if (tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_PAD ||
1474		    tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_TMR) {
1475			UPDATE_HEAD(udev->cmdr_last_cleaned,
1476				    tcmu_hdr_get_len(entry->hdr.len_op),
1477				    udev->cmdr_size);
1478			continue;
1479		}
1480		WARN_ON(tcmu_hdr_get_op(entry->hdr.len_op) != TCMU_OP_CMD);
1481
1482		keep_buf = !!(entry->hdr.uflags & TCMU_UFLAG_KEEP_BUF);
1483		if (keep_buf)
1484			cmd = xa_load(&udev->commands, entry->hdr.cmd_id);
1485		else
1486			cmd = xa_erase(&udev->commands, entry->hdr.cmd_id);
1487		if (!cmd) {
1488			pr_err("cmd_id %u not found, ring is broken\n",
1489			       entry->hdr.cmd_id);
1490			set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
1491			return false;
1492		}
1493
1494		if (!tcmu_handle_completion(cmd, entry, keep_buf))
1495			break;
1496
1497		UPDATE_HEAD(udev->cmdr_last_cleaned,
1498			    tcmu_hdr_get_len(entry->hdr.len_op),
1499			    udev->cmdr_size);
1500	}
1501	if (free_space)
1502		free_space = tcmu_run_tmr_queue(udev);
1503
1504	if (atomic_read(&global_page_count) > tcmu_global_max_pages &&
1505	    xa_empty(&udev->commands) && list_empty(&udev->qfull_queue)) {
1506		/*
1507		 * Allocated blocks exceeded global block limit, currently no
1508		 * more pending or waiting commands so try to reclaim blocks.
1509		 */
1510		schedule_delayed_work(&tcmu_unmap_work, 0);
1511	}
1512	if (udev->cmd_time_out)
1513		tcmu_set_next_deadline(&udev->inflight_queue, &udev->cmd_timer);
1514
1515	return free_space;
1516}
1517
1518static void tcmu_check_expired_ring_cmd(struct tcmu_cmd *cmd)
1519{
1520	struct se_cmd *se_cmd;
1521
1522	if (!time_after_eq(jiffies, cmd->deadline))
1523		return;
1524
1525	set_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags);
1526	list_del_init(&cmd->queue_entry);
1527	se_cmd = cmd->se_cmd;
1528	se_cmd->priv = NULL;
1529	cmd->se_cmd = NULL;
1530
1531	pr_debug("Timing out inflight cmd %u on dev %s.\n",
1532		 cmd->cmd_id, cmd->tcmu_dev->name);
1533
1534	target_complete_cmd(se_cmd, SAM_STAT_CHECK_CONDITION);
1535}
1536
1537static void tcmu_check_expired_queue_cmd(struct tcmu_cmd *cmd)
1538{
1539	struct se_cmd *se_cmd;
1540
1541	if (!time_after_eq(jiffies, cmd->deadline))
1542		return;
1543
1544	pr_debug("Timing out queued cmd %p on dev %s.\n",
1545		  cmd, cmd->tcmu_dev->name);
1546
1547	list_del_init(&cmd->queue_entry);
1548	se_cmd = cmd->se_cmd;
1549	tcmu_free_cmd(cmd);
1550
1551	se_cmd->priv = NULL;
1552	target_complete_cmd(se_cmd, SAM_STAT_TASK_SET_FULL);
1553}
1554
1555static void tcmu_device_timedout(struct tcmu_dev *udev)
1556{
1557	spin_lock(&timed_out_udevs_lock);
1558	if (list_empty(&udev->timedout_entry))
1559		list_add_tail(&udev->timedout_entry, &timed_out_udevs);
1560	spin_unlock(&timed_out_udevs_lock);
1561
1562	schedule_delayed_work(&tcmu_unmap_work, 0);
1563}
1564
1565static void tcmu_cmd_timedout(struct timer_list *t)
1566{
1567	struct tcmu_dev *udev = from_timer(udev, t, cmd_timer);
1568
1569	pr_debug("%s cmd timeout has expired\n", udev->name);
1570	tcmu_device_timedout(udev);
1571}
1572
1573static void tcmu_qfull_timedout(struct timer_list *t)
1574{
1575	struct tcmu_dev *udev = from_timer(udev, t, qfull_timer);
1576
1577	pr_debug("%s qfull timeout has expired\n", udev->name);
1578	tcmu_device_timedout(udev);
1579}
1580
1581static int tcmu_attach_hba(struct se_hba *hba, u32 host_id)
1582{
1583	struct tcmu_hba *tcmu_hba;
1584
1585	tcmu_hba = kzalloc(sizeof(struct tcmu_hba), GFP_KERNEL);
1586	if (!tcmu_hba)
1587		return -ENOMEM;
1588
1589	tcmu_hba->host_id = host_id;
1590	hba->hba_ptr = tcmu_hba;
1591
1592	return 0;
1593}
1594
1595static void tcmu_detach_hba(struct se_hba *hba)
1596{
1597	kfree(hba->hba_ptr);
1598	hba->hba_ptr = NULL;
1599}
1600
1601static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name)
1602{
1603	struct tcmu_dev *udev;
1604
1605	udev = kzalloc(sizeof(struct tcmu_dev), GFP_KERNEL);
1606	if (!udev)
1607		return NULL;
1608	kref_init(&udev->kref);
1609
1610	udev->name = kstrdup(name, GFP_KERNEL);
1611	if (!udev->name) {
1612		kfree(udev);
1613		return NULL;
1614	}
1615
1616	udev->hba = hba;
1617	udev->cmd_time_out = TCMU_TIME_OUT;
1618	udev->qfull_time_out = -1;
1619
1620	udev->data_pages_per_blk = DATA_PAGES_PER_BLK_DEF;
1621	udev->max_blocks = DATA_AREA_PAGES_DEF / udev->data_pages_per_blk;
1622	udev->cmdr_size = CMDR_SIZE_DEF;
1623	udev->data_area_mb = TCMU_PAGES_TO_MBS(DATA_AREA_PAGES_DEF);
1624
1625	mutex_init(&udev->cmdr_lock);
1626
1627	INIT_LIST_HEAD(&udev->node);
1628	INIT_LIST_HEAD(&udev->timedout_entry);
1629	INIT_LIST_HEAD(&udev->qfull_queue);
1630	INIT_LIST_HEAD(&udev->tmr_queue);
1631	INIT_LIST_HEAD(&udev->inflight_queue);
1632	xa_init_flags(&udev->commands, XA_FLAGS_ALLOC1);
1633
1634	timer_setup(&udev->qfull_timer, tcmu_qfull_timedout, 0);
1635	timer_setup(&udev->cmd_timer, tcmu_cmd_timedout, 0);
1636
1637	xa_init(&udev->data_pages);
1638
1639	return &udev->se_dev;
1640}
1641
1642static void tcmu_dev_call_rcu(struct rcu_head *p)
1643{
1644	struct se_device *dev = container_of(p, struct se_device, rcu_head);
1645	struct tcmu_dev *udev = TCMU_DEV(dev);
1646
1647	kfree(udev->uio_info.name);
1648	kfree(udev->name);
1649	kfree(udev);
1650}
1651
1652static int tcmu_check_and_free_pending_cmd(struct tcmu_cmd *cmd)
1653{
1654	if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags) ||
1655	    test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags)) {
1656		kmem_cache_free(tcmu_cmd_cache, cmd);
1657		return 0;
1658	}
1659	return -EINVAL;
1660}
1661
1662static u32 tcmu_blocks_release(struct tcmu_dev *udev, unsigned long first,
1663				unsigned long last)
1664{
 
1665	struct page *page;
1666	unsigned long dpi;
1667	u32 pages_freed = 0;
1668
1669	first = first * udev->data_pages_per_blk;
1670	last = (last + 1) * udev->data_pages_per_blk - 1;
1671	xa_for_each_range(&udev->data_pages, dpi, page, first, last) {
1672		xa_erase(&udev->data_pages, dpi);
1673		/*
1674		 * While reaching here there may be page faults occurring on
1675		 * the to-be-released pages. A race condition may occur if
1676		 * unmap_mapping_range() is called before page faults on these
1677		 * pages have completed; a valid but stale map is created.
1678		 *
1679		 * If another command subsequently runs and needs to extend
1680		 * dbi_thresh, it may reuse the slot corresponding to the
1681		 * previous page in data_bitmap. Though we will allocate a new
1682		 * page for the slot in data_area, no page fault will happen
1683		 * because we have a valid map. Therefore the command's data
1684		 * will be lost.
1685		 *
1686		 * We lock and unlock pages that are to be released to ensure
1687		 * all page faults have completed. This way
1688		 * unmap_mapping_range() can ensure stale maps are cleanly
1689		 * removed.
1690		 */
1691		lock_page(page);
1692		unlock_page(page);
1693		__free_page(page);
1694		pages_freed++;
1695	}
 
1696
1697	atomic_sub(pages_freed, &global_page_count);
1698
1699	return pages_freed;
1700}
1701
1702static void tcmu_remove_all_queued_tmr(struct tcmu_dev *udev)
1703{
1704	struct tcmu_tmr *tmr, *tmp;
1705
1706	list_for_each_entry_safe(tmr, tmp, &udev->tmr_queue, queue_entry) {
1707		list_del_init(&tmr->queue_entry);
1708		kfree(tmr);
1709	}
1710}
1711
1712static void tcmu_dev_kref_release(struct kref *kref)
1713{
1714	struct tcmu_dev *udev = container_of(kref, struct tcmu_dev, kref);
1715	struct se_device *dev = &udev->se_dev;
1716	struct tcmu_cmd *cmd;
1717	bool all_expired = true;
1718	unsigned long i;
1719
1720	vfree(udev->mb_addr);
1721	udev->mb_addr = NULL;
1722
1723	spin_lock_bh(&timed_out_udevs_lock);
1724	if (!list_empty(&udev->timedout_entry))
1725		list_del(&udev->timedout_entry);
1726	spin_unlock_bh(&timed_out_udevs_lock);
1727
1728	/* Upper layer should drain all requests before calling this */
1729	mutex_lock(&udev->cmdr_lock);
1730	xa_for_each(&udev->commands, i, cmd) {
1731		if (tcmu_check_and_free_pending_cmd(cmd) != 0)
1732			all_expired = false;
1733	}
1734	/* There can be left over TMR cmds. Remove them. */
1735	tcmu_remove_all_queued_tmr(udev);
1736	if (!list_empty(&udev->qfull_queue))
1737		all_expired = false;
1738	xa_destroy(&udev->commands);
1739	WARN_ON(!all_expired);
1740
1741	tcmu_blocks_release(udev, 0, udev->dbi_max);
1742	bitmap_free(udev->data_bitmap);
1743	mutex_unlock(&udev->cmdr_lock);
1744
1745	pr_debug("dev_kref_release\n");
1746
1747	call_rcu(&dev->rcu_head, tcmu_dev_call_rcu);
1748}
1749
1750static void run_qfull_queue(struct tcmu_dev *udev, bool fail)
1751{
1752	struct tcmu_cmd *tcmu_cmd, *tmp_cmd;
1753	LIST_HEAD(cmds);
1754	sense_reason_t scsi_ret;
1755	int ret;
1756
1757	if (list_empty(&udev->qfull_queue))
1758		return;
1759
1760	pr_debug("running %s's cmdr queue forcefail %d\n", udev->name, fail);
1761
1762	list_splice_init(&udev->qfull_queue, &cmds);
1763
1764	list_for_each_entry_safe(tcmu_cmd, tmp_cmd, &cmds, queue_entry) {
1765		list_del_init(&tcmu_cmd->queue_entry);
1766
1767		pr_debug("removing cmd %p on dev %s from queue\n",
1768			 tcmu_cmd, udev->name);
1769
1770		if (fail) {
1771			/*
1772			 * We were not able to even start the command, so
1773			 * fail with busy to allow a retry in case runner
1774			 * was only temporarily down. If the device is being
1775			 * removed then LIO core will do the right thing and
1776			 * fail the retry.
1777			 */
1778			tcmu_cmd->se_cmd->priv = NULL;
1779			target_complete_cmd(tcmu_cmd->se_cmd, SAM_STAT_BUSY);
1780			tcmu_free_cmd(tcmu_cmd);
1781			continue;
1782		}
1783
1784		ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
1785		if (ret < 0) {
1786			pr_debug("cmd %p on dev %s failed with %u\n",
1787				 tcmu_cmd, udev->name, scsi_ret);
1788			/*
1789			 * Ignore scsi_ret for now. target_complete_cmd
1790			 * drops it.
1791			 */
1792			tcmu_cmd->se_cmd->priv = NULL;
1793			target_complete_cmd(tcmu_cmd->se_cmd,
1794					    SAM_STAT_CHECK_CONDITION);
1795			tcmu_free_cmd(tcmu_cmd);
1796		} else if (ret > 0) {
1797			pr_debug("ran out of space during cmdr queue run\n");
1798			/*
1799			 * cmd was requeued, so just put all cmds back in
1800			 * the queue
1801			 */
1802			list_splice_tail(&cmds, &udev->qfull_queue);
1803			break;
1804		}
1805	}
1806
1807	tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
1808}
1809
1810static int tcmu_irqcontrol(struct uio_info *info, s32 irq_on)
1811{
1812	struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1813
1814	mutex_lock(&udev->cmdr_lock);
1815	if (tcmu_handle_completions(udev))
1816		run_qfull_queue(udev, false);
1817	mutex_unlock(&udev->cmdr_lock);
1818
1819	return 0;
1820}
1821
1822/*
1823 * mmap code from uio.c. Copied here because we want to hook mmap()
1824 * and this stuff must come along.
1825 */
1826static int tcmu_find_mem_index(struct vm_area_struct *vma)
1827{
1828	struct tcmu_dev *udev = vma->vm_private_data;
1829	struct uio_info *info = &udev->uio_info;
1830
1831	if (vma->vm_pgoff < MAX_UIO_MAPS) {
1832		if (info->mem[vma->vm_pgoff].size == 0)
1833			return -1;
1834		return (int)vma->vm_pgoff;
1835	}
1836	return -1;
1837}
1838
1839static struct page *tcmu_try_get_data_page(struct tcmu_dev *udev, uint32_t dpi)
1840{
1841	struct page *page;
1842
1843	mutex_lock(&udev->cmdr_lock);
1844	page = xa_load(&udev->data_pages, dpi);
1845	if (likely(page)) {
1846		get_page(page);
1847		lock_page(page);
1848		mutex_unlock(&udev->cmdr_lock);
1849		return page;
1850	}
1851
1852	/*
1853	 * Userspace messed up and passed in a address not in the
1854	 * data iov passed to it.
1855	 */
1856	pr_err("Invalid addr to data page mapping (dpi %u) on device %s\n",
1857	       dpi, udev->name);
1858	mutex_unlock(&udev->cmdr_lock);
1859
1860	return NULL;
1861}
1862
1863static void tcmu_vma_open(struct vm_area_struct *vma)
1864{
1865	struct tcmu_dev *udev = vma->vm_private_data;
1866
1867	pr_debug("vma_open\n");
1868
1869	kref_get(&udev->kref);
1870}
1871
1872static void tcmu_vma_close(struct vm_area_struct *vma)
1873{
1874	struct tcmu_dev *udev = vma->vm_private_data;
1875
1876	pr_debug("vma_close\n");
1877
1878	/* release ref from tcmu_vma_open */
1879	kref_put(&udev->kref, tcmu_dev_kref_release);
1880}
1881
1882static vm_fault_t tcmu_vma_fault(struct vm_fault *vmf)
1883{
1884	struct tcmu_dev *udev = vmf->vma->vm_private_data;
1885	struct uio_info *info = &udev->uio_info;
1886	struct page *page;
1887	unsigned long offset;
1888	void *addr;
1889	vm_fault_t ret = 0;
1890
1891	int mi = tcmu_find_mem_index(vmf->vma);
1892	if (mi < 0)
1893		return VM_FAULT_SIGBUS;
1894
1895	/*
1896	 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
1897	 * to use mem[N].
1898	 */
1899	offset = (vmf->pgoff - mi) << PAGE_SHIFT;
1900
1901	if (offset < udev->data_off) {
1902		/* For the vmalloc()ed cmd area pages */
1903		addr = (void *)(unsigned long)info->mem[mi].addr + offset;
1904		page = vmalloc_to_page(addr);
1905		get_page(page);
1906	} else {
1907		uint32_t dpi;
1908
1909		/* For the dynamically growing data area pages */
1910		dpi = (offset - udev->data_off) / PAGE_SIZE;
1911		page = tcmu_try_get_data_page(udev, dpi);
1912		if (!page)
1913			return VM_FAULT_SIGBUS;
1914		ret = VM_FAULT_LOCKED;
1915	}
1916
 
1917	vmf->page = page;
1918	return ret;
1919}
1920
1921static const struct vm_operations_struct tcmu_vm_ops = {
1922	.open = tcmu_vma_open,
1923	.close = tcmu_vma_close,
1924	.fault = tcmu_vma_fault,
1925};
1926
1927static int tcmu_mmap(struct uio_info *info, struct vm_area_struct *vma)
1928{
1929	struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1930
1931	vm_flags_set(vma, VM_DONTEXPAND | VM_DONTDUMP);
1932	vma->vm_ops = &tcmu_vm_ops;
1933
1934	vma->vm_private_data = udev;
1935
1936	/* Ensure the mmap is exactly the right size */
1937	if (vma_pages(vma) != udev->mmap_pages)
1938		return -EINVAL;
1939
1940	tcmu_vma_open(vma);
1941
1942	return 0;
1943}
1944
1945static int tcmu_open(struct uio_info *info, struct inode *inode)
1946{
1947	struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1948
1949	/* O_EXCL not supported for char devs, so fake it? */
1950	if (test_and_set_bit(TCMU_DEV_BIT_OPEN, &udev->flags))
1951		return -EBUSY;
1952
1953	udev->inode = inode;
1954
1955	pr_debug("open\n");
1956
1957	return 0;
1958}
1959
1960static int tcmu_release(struct uio_info *info, struct inode *inode)
1961{
1962	struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1963	struct tcmu_cmd *cmd;
1964	unsigned long i;
1965	bool freed = false;
1966
1967	mutex_lock(&udev->cmdr_lock);
1968
1969	xa_for_each(&udev->commands, i, cmd) {
1970		/* Cmds with KEEP_BUF set are no longer on the ring, but
1971		 * userspace still holds the data buffer. If userspace closes
1972		 * we implicitly free these cmds and buffers, since after new
1973		 * open the (new ?) userspace cannot find the cmd in the ring
1974		 * and thus never will release the buffer by writing cmd_id to
1975		 * free_kept_buf action attribute.
1976		 */
1977		if (!test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags))
1978			continue;
1979		pr_debug("removing KEEP_BUF cmd %u on dev %s from ring\n",
1980			 cmd->cmd_id, udev->name);
1981		freed = true;
1982
1983		xa_erase(&udev->commands, i);
1984		tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
1985		tcmu_free_cmd(cmd);
1986	}
1987	/*
1988	 * We only freed data space, not ring space. Therefore we dont call
1989	 * run_tmr_queue, but call run_qfull_queue if tmr_list is empty.
1990	 */
1991	if (freed && list_empty(&udev->tmr_queue))
1992		run_qfull_queue(udev, false);
1993
1994	mutex_unlock(&udev->cmdr_lock);
1995
1996	clear_bit(TCMU_DEV_BIT_OPEN, &udev->flags);
1997
1998	pr_debug("close\n");
1999
2000	return 0;
2001}
2002
2003static int tcmu_init_genl_cmd_reply(struct tcmu_dev *udev, int cmd)
2004{
2005	struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
2006
2007	if (!tcmu_kern_cmd_reply_supported)
2008		return 0;
2009
2010	if (udev->nl_reply_supported <= 0)
2011		return 0;
2012
2013	mutex_lock(&tcmu_nl_cmd_mutex);
2014
2015	if (tcmu_netlink_blocked) {
2016		mutex_unlock(&tcmu_nl_cmd_mutex);
2017		pr_warn("Failing nl cmd %d on %s. Interface is blocked.\n", cmd,
2018			udev->name);
2019		return -EAGAIN;
2020	}
2021
2022	if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
2023		mutex_unlock(&tcmu_nl_cmd_mutex);
2024		pr_warn("netlink cmd %d already executing on %s\n",
2025			 nl_cmd->cmd, udev->name);
2026		return -EBUSY;
2027	}
2028
2029	memset(nl_cmd, 0, sizeof(*nl_cmd));
2030	nl_cmd->cmd = cmd;
2031	nl_cmd->udev = udev;
2032	init_completion(&nl_cmd->complete);
2033	INIT_LIST_HEAD(&nl_cmd->nl_list);
2034
2035	list_add_tail(&nl_cmd->nl_list, &tcmu_nl_cmd_list);
2036
2037	mutex_unlock(&tcmu_nl_cmd_mutex);
2038	return 0;
2039}
2040
2041static void tcmu_destroy_genl_cmd_reply(struct tcmu_dev *udev)
2042{
2043	struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
2044
2045	if (!tcmu_kern_cmd_reply_supported)
2046		return;
2047
2048	if (udev->nl_reply_supported <= 0)
2049		return;
2050
2051	mutex_lock(&tcmu_nl_cmd_mutex);
2052
2053	list_del(&nl_cmd->nl_list);
2054	memset(nl_cmd, 0, sizeof(*nl_cmd));
2055
2056	mutex_unlock(&tcmu_nl_cmd_mutex);
2057}
2058
2059static int tcmu_wait_genl_cmd_reply(struct tcmu_dev *udev)
2060{
2061	struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
2062	int ret;
2063
2064	if (!tcmu_kern_cmd_reply_supported)
2065		return 0;
2066
2067	if (udev->nl_reply_supported <= 0)
2068		return 0;
2069
2070	pr_debug("sleeping for nl reply\n");
2071	wait_for_completion(&nl_cmd->complete);
2072
2073	mutex_lock(&tcmu_nl_cmd_mutex);
2074	nl_cmd->cmd = TCMU_CMD_UNSPEC;
2075	ret = nl_cmd->status;
2076	mutex_unlock(&tcmu_nl_cmd_mutex);
2077
2078	return ret;
2079}
2080
2081static int tcmu_netlink_event_init(struct tcmu_dev *udev,
2082				   enum tcmu_genl_cmd cmd,
2083				   struct sk_buff **buf, void **hdr)
2084{
2085	struct sk_buff *skb;
2086	void *msg_header;
2087	int ret = -ENOMEM;
2088
2089	skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2090	if (!skb)
2091		return ret;
2092
2093	msg_header = genlmsg_put(skb, 0, 0, &tcmu_genl_family, 0, cmd);
2094	if (!msg_header)
2095		goto free_skb;
2096
2097	ret = nla_put_string(skb, TCMU_ATTR_DEVICE, udev->uio_info.name);
2098	if (ret < 0)
2099		goto free_skb;
2100
2101	ret = nla_put_u32(skb, TCMU_ATTR_MINOR, udev->uio_info.uio_dev->minor);
2102	if (ret < 0)
2103		goto free_skb;
2104
2105	ret = nla_put_u32(skb, TCMU_ATTR_DEVICE_ID, udev->se_dev.dev_index);
2106	if (ret < 0)
2107		goto free_skb;
2108
2109	*buf = skb;
2110	*hdr = msg_header;
2111	return ret;
2112
2113free_skb:
2114	nlmsg_free(skb);
2115	return ret;
2116}
2117
2118static int tcmu_netlink_event_send(struct tcmu_dev *udev,
2119				   enum tcmu_genl_cmd cmd,
2120				   struct sk_buff *skb, void *msg_header)
2121{
2122	int ret;
2123
2124	genlmsg_end(skb, msg_header);
2125
2126	ret = tcmu_init_genl_cmd_reply(udev, cmd);
2127	if (ret) {
2128		nlmsg_free(skb);
2129		return ret;
2130	}
2131
2132	ret = genlmsg_multicast_allns(&tcmu_genl_family, skb, 0,
2133				      TCMU_MCGRP_CONFIG);
2134
2135	/* Wait during an add as the listener may not be up yet */
2136	if (ret == 0 ||
2137	   (ret == -ESRCH && cmd == TCMU_CMD_ADDED_DEVICE))
2138		return tcmu_wait_genl_cmd_reply(udev);
2139	else
2140		tcmu_destroy_genl_cmd_reply(udev);
2141
2142	return ret;
2143}
2144
2145static int tcmu_send_dev_add_event(struct tcmu_dev *udev)
2146{
2147	struct sk_buff *skb = NULL;
2148	void *msg_header = NULL;
2149	int ret = 0;
2150
2151	ret = tcmu_netlink_event_init(udev, TCMU_CMD_ADDED_DEVICE, &skb,
2152				      &msg_header);
2153	if (ret < 0)
2154		return ret;
2155	return tcmu_netlink_event_send(udev, TCMU_CMD_ADDED_DEVICE, skb,
2156				       msg_header);
2157}
2158
2159static int tcmu_send_dev_remove_event(struct tcmu_dev *udev)
2160{
2161	struct sk_buff *skb = NULL;
2162	void *msg_header = NULL;
2163	int ret = 0;
2164
2165	ret = tcmu_netlink_event_init(udev, TCMU_CMD_REMOVED_DEVICE,
2166				      &skb, &msg_header);
2167	if (ret < 0)
2168		return ret;
2169	return tcmu_netlink_event_send(udev, TCMU_CMD_REMOVED_DEVICE,
2170				       skb, msg_header);
2171}
2172
2173static int tcmu_update_uio_info(struct tcmu_dev *udev)
2174{
2175	struct tcmu_hba *hba = udev->hba->hba_ptr;
2176	struct uio_info *info;
2177	char *str;
2178
2179	info = &udev->uio_info;
2180
2181	if (udev->dev_config[0])
2182		str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s/%s", hba->host_id,
2183				udev->name, udev->dev_config);
2184	else
2185		str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s", hba->host_id,
2186				udev->name);
2187	if (!str)
2188		return -ENOMEM;
2189
2190	/* If the old string exists, free it */
2191	kfree(info->name);
2192	info->name = str;
2193
2194	return 0;
2195}
2196
2197static int tcmu_configure_device(struct se_device *dev)
2198{
2199	struct tcmu_dev *udev = TCMU_DEV(dev);
2200	struct uio_info *info;
2201	struct tcmu_mailbox *mb;
2202	size_t data_size;
2203	int ret = 0;
2204
2205	ret = tcmu_update_uio_info(udev);
2206	if (ret)
2207		return ret;
2208
2209	info = &udev->uio_info;
2210
2211	mutex_lock(&udev->cmdr_lock);
2212	udev->data_bitmap = bitmap_zalloc(udev->max_blocks, GFP_KERNEL);
2213	mutex_unlock(&udev->cmdr_lock);
2214	if (!udev->data_bitmap) {
2215		ret = -ENOMEM;
2216		goto err_bitmap_alloc;
2217	}
2218
2219	mb = vzalloc(udev->cmdr_size + CMDR_OFF);
2220	if (!mb) {
2221		ret = -ENOMEM;
2222		goto err_vzalloc;
2223	}
2224
2225	/* mailbox fits in first part of CMDR space */
2226	udev->mb_addr = mb;
2227	udev->cmdr = (void *)mb + CMDR_OFF;
2228	udev->data_off = udev->cmdr_size + CMDR_OFF;
 
2229	data_size = TCMU_MBS_TO_PAGES(udev->data_area_mb) << PAGE_SHIFT;
2230	udev->mmap_pages = (data_size + udev->cmdr_size + CMDR_OFF) >> PAGE_SHIFT;
2231	udev->data_blk_size = udev->data_pages_per_blk * PAGE_SIZE;
2232	udev->dbi_thresh = 0; /* Default in Idle state */
2233
2234	/* Initialise the mailbox of the ring buffer */
2235	mb->version = TCMU_MAILBOX_VERSION;
2236	mb->flags = TCMU_MAILBOX_FLAG_CAP_OOOC |
2237		    TCMU_MAILBOX_FLAG_CAP_READ_LEN |
2238		    TCMU_MAILBOX_FLAG_CAP_TMR |
2239		    TCMU_MAILBOX_FLAG_CAP_KEEP_BUF;
2240	mb->cmdr_off = CMDR_OFF;
2241	mb->cmdr_size = udev->cmdr_size;
2242
2243	WARN_ON(!PAGE_ALIGNED(udev->data_off));
2244	WARN_ON(data_size % PAGE_SIZE);
2245
2246	info->version = __stringify(TCMU_MAILBOX_VERSION);
2247
2248	info->mem[0].name = "tcm-user command & data buffer";
2249	info->mem[0].addr = (phys_addr_t)(uintptr_t)udev->mb_addr;
2250	info->mem[0].size = data_size + udev->cmdr_size + CMDR_OFF;
2251	info->mem[0].memtype = UIO_MEM_NONE;
2252
2253	info->irqcontrol = tcmu_irqcontrol;
2254	info->irq = UIO_IRQ_CUSTOM;
2255
2256	info->mmap = tcmu_mmap;
2257	info->open = tcmu_open;
2258	info->release = tcmu_release;
2259
2260	ret = uio_register_device(tcmu_root_device, info);
2261	if (ret)
2262		goto err_register;
2263
2264	/* User can set hw_block_size before enable the device */
2265	if (dev->dev_attrib.hw_block_size == 0)
2266		dev->dev_attrib.hw_block_size = 512;
2267	/* Other attributes can be configured in userspace */
2268	if (!dev->dev_attrib.hw_max_sectors)
2269		dev->dev_attrib.hw_max_sectors = 128;
2270	if (!dev->dev_attrib.emulate_write_cache)
2271		dev->dev_attrib.emulate_write_cache = 0;
2272	dev->dev_attrib.hw_queue_depth = 128;
2273
2274	/* If user didn't explicitly disable netlink reply support, use
2275	 * module scope setting.
2276	 */
2277	if (udev->nl_reply_supported >= 0)
2278		udev->nl_reply_supported = tcmu_kern_cmd_reply_supported;
2279
2280	/*
2281	 * Get a ref incase userspace does a close on the uio device before
2282	 * LIO has initiated tcmu_free_device.
2283	 */
2284	kref_get(&udev->kref);
2285
2286	ret = tcmu_send_dev_add_event(udev);
2287	if (ret)
2288		goto err_netlink;
2289
2290	mutex_lock(&root_udev_mutex);
2291	list_add(&udev->node, &root_udev);
2292	mutex_unlock(&root_udev_mutex);
2293
2294	return 0;
2295
2296err_netlink:
2297	kref_put(&udev->kref, tcmu_dev_kref_release);
2298	uio_unregister_device(&udev->uio_info);
2299err_register:
2300	vfree(udev->mb_addr);
2301	udev->mb_addr = NULL;
2302err_vzalloc:
2303	bitmap_free(udev->data_bitmap);
2304	udev->data_bitmap = NULL;
2305err_bitmap_alloc:
2306	kfree(info->name);
2307	info->name = NULL;
2308
2309	return ret;
2310}
2311
2312static void tcmu_free_device(struct se_device *dev)
2313{
2314	struct tcmu_dev *udev = TCMU_DEV(dev);
2315
2316	/* release ref from init */
2317	kref_put(&udev->kref, tcmu_dev_kref_release);
2318}
2319
2320static void tcmu_destroy_device(struct se_device *dev)
2321{
2322	struct tcmu_dev *udev = TCMU_DEV(dev);
2323
2324	del_timer_sync(&udev->cmd_timer);
2325	del_timer_sync(&udev->qfull_timer);
2326
2327	mutex_lock(&root_udev_mutex);
2328	list_del(&udev->node);
2329	mutex_unlock(&root_udev_mutex);
2330
2331	tcmu_send_dev_remove_event(udev);
2332
2333	uio_unregister_device(&udev->uio_info);
2334
2335	/* release ref from configure */
2336	kref_put(&udev->kref, tcmu_dev_kref_release);
2337}
2338
2339static void tcmu_unblock_dev(struct tcmu_dev *udev)
2340{
2341	mutex_lock(&udev->cmdr_lock);
2342	clear_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags);
2343	mutex_unlock(&udev->cmdr_lock);
2344}
2345
2346static void tcmu_block_dev(struct tcmu_dev *udev)
2347{
2348	mutex_lock(&udev->cmdr_lock);
2349
2350	if (test_and_set_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
2351		goto unlock;
2352
2353	/* complete IO that has executed successfully */
2354	tcmu_handle_completions(udev);
2355	/* fail IO waiting to be queued */
2356	run_qfull_queue(udev, true);
2357
2358unlock:
2359	mutex_unlock(&udev->cmdr_lock);
2360}
2361
2362static void tcmu_reset_ring(struct tcmu_dev *udev, u8 err_level)
2363{
2364	struct tcmu_mailbox *mb;
2365	struct tcmu_cmd *cmd;
2366	unsigned long i;
2367
2368	mutex_lock(&udev->cmdr_lock);
2369
2370	xa_for_each(&udev->commands, i, cmd) {
2371		pr_debug("removing cmd %u on dev %s from ring %s\n",
2372			 cmd->cmd_id, udev->name,
2373			 test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags) ?
2374			 "(is expired)" :
2375			 (test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags) ?
2376			 "(is keep buffer)" : ""));
2377
2378		xa_erase(&udev->commands, i);
2379		if (!test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags) &&
2380		    !test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags)) {
2381			WARN_ON(!cmd->se_cmd);
2382			list_del_init(&cmd->queue_entry);
2383			cmd->se_cmd->priv = NULL;
2384			if (err_level == 1) {
2385				/*
2386				 * Userspace was not able to start the
2387				 * command or it is retryable.
2388				 */
2389				target_complete_cmd(cmd->se_cmd, SAM_STAT_BUSY);
2390			} else {
2391				/* hard failure */
2392				target_complete_cmd(cmd->se_cmd,
2393						    SAM_STAT_CHECK_CONDITION);
2394			}
2395		}
2396		tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
2397		tcmu_free_cmd(cmd);
2398	}
2399
2400	mb = udev->mb_addr;
2401	tcmu_flush_dcache_range(mb, sizeof(*mb));
2402	pr_debug("mb last %u head %u tail %u\n", udev->cmdr_last_cleaned,
2403		 mb->cmd_tail, mb->cmd_head);
2404
2405	udev->cmdr_last_cleaned = 0;
2406	mb->cmd_tail = 0;
2407	mb->cmd_head = 0;
2408	tcmu_flush_dcache_range(mb, sizeof(*mb));
2409	clear_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
2410
2411	del_timer(&udev->cmd_timer);
2412
2413	/*
2414	 * ring is empty and qfull queue never contains aborted commands.
2415	 * So TMRs in tmr queue do not contain relevant cmd_ids.
2416	 * After a ring reset userspace should do a fresh start, so
2417	 * even LUN RESET message is no longer relevant.
2418	 * Therefore remove all TMRs from qfull queue
2419	 */
2420	tcmu_remove_all_queued_tmr(udev);
2421
2422	run_qfull_queue(udev, false);
2423
2424	mutex_unlock(&udev->cmdr_lock);
2425}
2426
2427enum {
2428	Opt_dev_config, Opt_dev_size, Opt_hw_block_size, Opt_hw_max_sectors,
2429	Opt_nl_reply_supported, Opt_max_data_area_mb, Opt_data_pages_per_blk,
2430	Opt_cmd_ring_size_mb, Opt_err,
2431};
2432
2433static const match_table_t tokens = {
2434	{Opt_dev_config, "dev_config=%s"},
2435	{Opt_dev_size, "dev_size=%s"},
2436	{Opt_hw_block_size, "hw_block_size=%d"},
2437	{Opt_hw_max_sectors, "hw_max_sectors=%d"},
2438	{Opt_nl_reply_supported, "nl_reply_supported=%d"},
2439	{Opt_max_data_area_mb, "max_data_area_mb=%d"},
2440	{Opt_data_pages_per_blk, "data_pages_per_blk=%d"},
2441	{Opt_cmd_ring_size_mb, "cmd_ring_size_mb=%d"},
2442	{Opt_err, NULL}
2443};
2444
2445static int tcmu_set_dev_attrib(substring_t *arg, u32 *dev_attrib)
2446{
2447	int val, ret;
2448
2449	ret = match_int(arg, &val);
2450	if (ret < 0) {
2451		pr_err("match_int() failed for dev attrib. Error %d.\n",
2452		       ret);
2453		return ret;
2454	}
2455
2456	if (val <= 0) {
2457		pr_err("Invalid dev attrib value %d. Must be greater than zero.\n",
2458		       val);
2459		return -EINVAL;
2460	}
2461	*dev_attrib = val;
2462	return 0;
2463}
2464
2465static int tcmu_set_max_blocks_param(struct tcmu_dev *udev, substring_t *arg)
2466{
2467	int val, ret;
2468	uint32_t pages_per_blk = udev->data_pages_per_blk;
2469
2470	ret = match_int(arg, &val);
2471	if (ret < 0) {
2472		pr_err("match_int() failed for max_data_area_mb=. Error %d.\n",
2473		       ret);
2474		return ret;
2475	}
2476	if (val <= 0) {
2477		pr_err("Invalid max_data_area %d.\n", val);
2478		return -EINVAL;
2479	}
2480	if (val > TCMU_PAGES_TO_MBS(tcmu_global_max_pages)) {
2481		pr_err("%d is too large. Adjusting max_data_area_mb to global limit of %u\n",
2482		       val, TCMU_PAGES_TO_MBS(tcmu_global_max_pages));
2483		val = TCMU_PAGES_TO_MBS(tcmu_global_max_pages);
2484	}
2485	if (TCMU_MBS_TO_PAGES(val) < pages_per_blk) {
2486		pr_err("Invalid max_data_area %d (%zu pages): smaller than data_pages_per_blk (%u pages).\n",
2487		       val, TCMU_MBS_TO_PAGES(val), pages_per_blk);
2488		return -EINVAL;
2489	}
2490
2491	mutex_lock(&udev->cmdr_lock);
2492	if (udev->data_bitmap) {
2493		pr_err("Cannot set max_data_area_mb after it has been enabled.\n");
2494		ret = -EINVAL;
2495		goto unlock;
2496	}
2497
2498	udev->data_area_mb = val;
2499	udev->max_blocks = TCMU_MBS_TO_PAGES(val) / pages_per_blk;
2500
2501unlock:
2502	mutex_unlock(&udev->cmdr_lock);
2503	return ret;
2504}
2505
2506static int tcmu_set_data_pages_per_blk(struct tcmu_dev *udev, substring_t *arg)
2507{
2508	int val, ret;
2509
2510	ret = match_int(arg, &val);
2511	if (ret < 0) {
2512		pr_err("match_int() failed for data_pages_per_blk=. Error %d.\n",
2513		       ret);
2514		return ret;
2515	}
2516
2517	if (val > TCMU_MBS_TO_PAGES(udev->data_area_mb)) {
2518		pr_err("Invalid data_pages_per_blk %d: greater than max_data_area_mb %d -> %zd pages).\n",
2519		       val, udev->data_area_mb,
2520		       TCMU_MBS_TO_PAGES(udev->data_area_mb));
2521		return -EINVAL;
2522	}
2523
2524	mutex_lock(&udev->cmdr_lock);
2525	if (udev->data_bitmap) {
2526		pr_err("Cannot set data_pages_per_blk after it has been enabled.\n");
2527		ret = -EINVAL;
2528		goto unlock;
2529	}
2530
2531	udev->data_pages_per_blk = val;
2532	udev->max_blocks = TCMU_MBS_TO_PAGES(udev->data_area_mb) / val;
2533
2534unlock:
2535	mutex_unlock(&udev->cmdr_lock);
2536	return ret;
2537}
2538
2539static int tcmu_set_cmd_ring_size(struct tcmu_dev *udev, substring_t *arg)
2540{
2541	int val, ret;
2542
2543	ret = match_int(arg, &val);
2544	if (ret < 0) {
2545		pr_err("match_int() failed for cmd_ring_size_mb=. Error %d.\n",
2546		       ret);
2547		return ret;
2548	}
2549
2550	if (val <= 0) {
2551		pr_err("Invalid cmd_ring_size_mb %d.\n", val);
2552		return -EINVAL;
2553	}
2554
2555	mutex_lock(&udev->cmdr_lock);
2556	if (udev->data_bitmap) {
2557		pr_err("Cannot set cmd_ring_size_mb after it has been enabled.\n");
2558		ret = -EINVAL;
2559		goto unlock;
2560	}
2561
2562	udev->cmdr_size = (val << 20) - CMDR_OFF;
2563	if (val > (MB_CMDR_SIZE_DEF >> 20)) {
2564		pr_err("%d is too large. Adjusting cmd_ring_size_mb to global limit of %u\n",
2565		       val, (MB_CMDR_SIZE_DEF >> 20));
2566		udev->cmdr_size = CMDR_SIZE_DEF;
2567	}
2568
2569unlock:
2570	mutex_unlock(&udev->cmdr_lock);
2571	return ret;
2572}
2573
2574static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev,
2575		const char *page, ssize_t count)
2576{
2577	struct tcmu_dev *udev = TCMU_DEV(dev);
2578	char *orig, *ptr, *opts;
2579	substring_t args[MAX_OPT_ARGS];
2580	int ret = 0, token;
2581
2582	opts = kstrdup(page, GFP_KERNEL);
2583	if (!opts)
2584		return -ENOMEM;
2585
2586	orig = opts;
2587
2588	while ((ptr = strsep(&opts, ",\n")) != NULL) {
2589		if (!*ptr)
2590			continue;
2591
2592		token = match_token(ptr, tokens, args);
2593		switch (token) {
2594		case Opt_dev_config:
2595			if (match_strlcpy(udev->dev_config, &args[0],
2596					  TCMU_CONFIG_LEN) == 0) {
2597				ret = -EINVAL;
2598				break;
2599			}
2600			pr_debug("TCMU: Referencing Path: %s\n", udev->dev_config);
2601			break;
2602		case Opt_dev_size:
2603			ret = match_u64(&args[0], &udev->dev_size);
2604			if (ret < 0)
2605				pr_err("match_u64() failed for dev_size=. Error %d.\n",
2606				       ret);
2607			break;
2608		case Opt_hw_block_size:
2609			ret = tcmu_set_dev_attrib(&args[0],
2610					&(dev->dev_attrib.hw_block_size));
2611			break;
2612		case Opt_hw_max_sectors:
2613			ret = tcmu_set_dev_attrib(&args[0],
2614					&(dev->dev_attrib.hw_max_sectors));
2615			break;
2616		case Opt_nl_reply_supported:
2617			ret = match_int(&args[0], &udev->nl_reply_supported);
2618			if (ret < 0)
2619				pr_err("match_int() failed for nl_reply_supported=. Error %d.\n",
2620				       ret);
2621			break;
2622		case Opt_max_data_area_mb:
2623			ret = tcmu_set_max_blocks_param(udev, &args[0]);
2624			break;
2625		case Opt_data_pages_per_blk:
2626			ret = tcmu_set_data_pages_per_blk(udev, &args[0]);
2627			break;
2628		case Opt_cmd_ring_size_mb:
2629			ret = tcmu_set_cmd_ring_size(udev, &args[0]);
2630			break;
2631		default:
2632			break;
2633		}
2634
2635		if (ret)
2636			break;
2637	}
2638
2639	kfree(orig);
2640	return (!ret) ? count : ret;
2641}
2642
2643static ssize_t tcmu_show_configfs_dev_params(struct se_device *dev, char *b)
2644{
2645	struct tcmu_dev *udev = TCMU_DEV(dev);
2646	ssize_t bl = 0;
2647
2648	bl = sprintf(b + bl, "Config: %s ",
2649		     udev->dev_config[0] ? udev->dev_config : "NULL");
2650	bl += sprintf(b + bl, "Size: %llu ", udev->dev_size);
2651	bl += sprintf(b + bl, "MaxDataAreaMB: %u ", udev->data_area_mb);
2652	bl += sprintf(b + bl, "DataPagesPerBlk: %u ", udev->data_pages_per_blk);
2653	bl += sprintf(b + bl, "CmdRingSizeMB: %u\n",
2654		      (udev->cmdr_size + CMDR_OFF) >> 20);
2655
2656	return bl;
2657}
2658
2659static sector_t tcmu_get_blocks(struct se_device *dev)
2660{
2661	struct tcmu_dev *udev = TCMU_DEV(dev);
2662
2663	return div_u64(udev->dev_size - dev->dev_attrib.block_size,
2664		       dev->dev_attrib.block_size);
2665}
2666
2667static sense_reason_t
2668tcmu_parse_cdb(struct se_cmd *cmd)
2669{
2670	return passthrough_parse_cdb(cmd, tcmu_queue_cmd);
2671}
2672
2673static ssize_t tcmu_cmd_time_out_show(struct config_item *item, char *page)
2674{
2675	struct se_dev_attrib *da = container_of(to_config_group(item),
2676					struct se_dev_attrib, da_group);
2677	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2678
2679	return snprintf(page, PAGE_SIZE, "%lu\n", udev->cmd_time_out / MSEC_PER_SEC);
2680}
2681
2682static ssize_t tcmu_cmd_time_out_store(struct config_item *item, const char *page,
2683				       size_t count)
2684{
2685	struct se_dev_attrib *da = container_of(to_config_group(item),
2686					struct se_dev_attrib, da_group);
2687	struct tcmu_dev *udev = container_of(da->da_dev,
2688					struct tcmu_dev, se_dev);
2689	u32 val;
2690	int ret;
2691
2692	if (da->da_dev->export_count) {
2693		pr_err("Unable to set tcmu cmd_time_out while exports exist\n");
2694		return -EINVAL;
2695	}
2696
2697	ret = kstrtou32(page, 0, &val);
2698	if (ret < 0)
2699		return ret;
2700
2701	udev->cmd_time_out = val * MSEC_PER_SEC;
2702	return count;
2703}
2704CONFIGFS_ATTR(tcmu_, cmd_time_out);
2705
2706static ssize_t tcmu_qfull_time_out_show(struct config_item *item, char *page)
2707{
2708	struct se_dev_attrib *da = container_of(to_config_group(item),
2709						struct se_dev_attrib, da_group);
2710	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2711
2712	return snprintf(page, PAGE_SIZE, "%ld\n", udev->qfull_time_out <= 0 ?
2713			udev->qfull_time_out :
2714			udev->qfull_time_out / MSEC_PER_SEC);
2715}
2716
2717static ssize_t tcmu_qfull_time_out_store(struct config_item *item,
2718					 const char *page, size_t count)
2719{
2720	struct se_dev_attrib *da = container_of(to_config_group(item),
2721					struct se_dev_attrib, da_group);
2722	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2723	s32 val;
2724	int ret;
2725
2726	ret = kstrtos32(page, 0, &val);
2727	if (ret < 0)
2728		return ret;
2729
2730	if (val >= 0) {
2731		udev->qfull_time_out = val * MSEC_PER_SEC;
2732	} else if (val == -1) {
2733		udev->qfull_time_out = val;
2734	} else {
2735		printk(KERN_ERR "Invalid qfull timeout value %d\n", val);
2736		return -EINVAL;
2737	}
2738	return count;
2739}
2740CONFIGFS_ATTR(tcmu_, qfull_time_out);
2741
2742static ssize_t tcmu_max_data_area_mb_show(struct config_item *item, char *page)
2743{
2744	struct se_dev_attrib *da = container_of(to_config_group(item),
2745						struct se_dev_attrib, da_group);
2746	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2747
2748	return snprintf(page, PAGE_SIZE, "%u\n", udev->data_area_mb);
2749}
2750CONFIGFS_ATTR_RO(tcmu_, max_data_area_mb);
2751
2752static ssize_t tcmu_data_pages_per_blk_show(struct config_item *item,
2753					    char *page)
2754{
2755	struct se_dev_attrib *da = container_of(to_config_group(item),
2756						struct se_dev_attrib, da_group);
2757	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2758
2759	return snprintf(page, PAGE_SIZE, "%u\n", udev->data_pages_per_blk);
2760}
2761CONFIGFS_ATTR_RO(tcmu_, data_pages_per_blk);
2762
2763static ssize_t tcmu_cmd_ring_size_mb_show(struct config_item *item, char *page)
2764{
2765	struct se_dev_attrib *da = container_of(to_config_group(item),
2766						struct se_dev_attrib, da_group);
2767	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2768
2769	return snprintf(page, PAGE_SIZE, "%u\n",
2770			(udev->cmdr_size + CMDR_OFF) >> 20);
2771}
2772CONFIGFS_ATTR_RO(tcmu_, cmd_ring_size_mb);
2773
2774static ssize_t tcmu_dev_config_show(struct config_item *item, char *page)
2775{
2776	struct se_dev_attrib *da = container_of(to_config_group(item),
2777						struct se_dev_attrib, da_group);
2778	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2779
2780	return snprintf(page, PAGE_SIZE, "%s\n", udev->dev_config);
2781}
2782
2783static int tcmu_send_dev_config_event(struct tcmu_dev *udev,
2784				      const char *reconfig_data)
2785{
2786	struct sk_buff *skb = NULL;
2787	void *msg_header = NULL;
2788	int ret = 0;
2789
2790	ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2791				      &skb, &msg_header);
2792	if (ret < 0)
2793		return ret;
2794	ret = nla_put_string(skb, TCMU_ATTR_DEV_CFG, reconfig_data);
2795	if (ret < 0) {
2796		nlmsg_free(skb);
2797		return ret;
2798	}
2799	return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2800				       skb, msg_header);
2801}
2802
2803
2804static ssize_t tcmu_dev_config_store(struct config_item *item, const char *page,
2805				     size_t count)
2806{
2807	struct se_dev_attrib *da = container_of(to_config_group(item),
2808						struct se_dev_attrib, da_group);
2809	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2810	int ret, len;
2811
2812	len = strlen(page);
2813	if (!len || len > TCMU_CONFIG_LEN - 1)
2814		return -EINVAL;
2815
2816	/* Check if device has been configured before */
2817	if (target_dev_configured(&udev->se_dev)) {
2818		ret = tcmu_send_dev_config_event(udev, page);
2819		if (ret) {
2820			pr_err("Unable to reconfigure device\n");
2821			return ret;
2822		}
2823		strscpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2824
2825		ret = tcmu_update_uio_info(udev);
2826		if (ret)
2827			return ret;
2828		return count;
2829	}
2830	strscpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2831
2832	return count;
2833}
2834CONFIGFS_ATTR(tcmu_, dev_config);
2835
2836static ssize_t tcmu_dev_size_show(struct config_item *item, char *page)
2837{
2838	struct se_dev_attrib *da = container_of(to_config_group(item),
2839						struct se_dev_attrib, da_group);
2840	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2841
2842	return snprintf(page, PAGE_SIZE, "%llu\n", udev->dev_size);
2843}
2844
2845static int tcmu_send_dev_size_event(struct tcmu_dev *udev, u64 size)
2846{
2847	struct sk_buff *skb = NULL;
2848	void *msg_header = NULL;
2849	int ret = 0;
2850
2851	ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2852				      &skb, &msg_header);
2853	if (ret < 0)
2854		return ret;
2855	ret = nla_put_u64_64bit(skb, TCMU_ATTR_DEV_SIZE,
2856				size, TCMU_ATTR_PAD);
2857	if (ret < 0) {
2858		nlmsg_free(skb);
2859		return ret;
2860	}
2861	return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2862				       skb, msg_header);
2863}
2864
2865static ssize_t tcmu_dev_size_store(struct config_item *item, const char *page,
2866				   size_t count)
2867{
2868	struct se_dev_attrib *da = container_of(to_config_group(item),
2869						struct se_dev_attrib, da_group);
2870	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2871	u64 val;
2872	int ret;
2873
2874	ret = kstrtou64(page, 0, &val);
2875	if (ret < 0)
2876		return ret;
2877
2878	/* Check if device has been configured before */
2879	if (target_dev_configured(&udev->se_dev)) {
2880		ret = tcmu_send_dev_size_event(udev, val);
2881		if (ret) {
2882			pr_err("Unable to reconfigure device\n");
2883			return ret;
2884		}
2885	}
2886	udev->dev_size = val;
2887	return count;
2888}
2889CONFIGFS_ATTR(tcmu_, dev_size);
2890
2891static ssize_t tcmu_nl_reply_supported_show(struct config_item *item,
2892		char *page)
2893{
2894	struct se_dev_attrib *da = container_of(to_config_group(item),
2895						struct se_dev_attrib, da_group);
2896	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2897
2898	return snprintf(page, PAGE_SIZE, "%d\n", udev->nl_reply_supported);
2899}
2900
2901static ssize_t tcmu_nl_reply_supported_store(struct config_item *item,
2902		const char *page, size_t count)
2903{
2904	struct se_dev_attrib *da = container_of(to_config_group(item),
2905						struct se_dev_attrib, da_group);
2906	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2907	s8 val;
2908	int ret;
2909
2910	ret = kstrtos8(page, 0, &val);
2911	if (ret < 0)
2912		return ret;
2913
2914	udev->nl_reply_supported = val;
2915	return count;
2916}
2917CONFIGFS_ATTR(tcmu_, nl_reply_supported);
2918
2919static ssize_t tcmu_emulate_write_cache_show(struct config_item *item,
2920					     char *page)
2921{
2922	struct se_dev_attrib *da = container_of(to_config_group(item),
2923					struct se_dev_attrib, da_group);
2924
2925	return snprintf(page, PAGE_SIZE, "%i\n", da->emulate_write_cache);
2926}
2927
2928static int tcmu_send_emulate_write_cache(struct tcmu_dev *udev, u8 val)
2929{
2930	struct sk_buff *skb = NULL;
2931	void *msg_header = NULL;
2932	int ret = 0;
2933
2934	ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2935				      &skb, &msg_header);
2936	if (ret < 0)
2937		return ret;
2938	ret = nla_put_u8(skb, TCMU_ATTR_WRITECACHE, val);
2939	if (ret < 0) {
2940		nlmsg_free(skb);
2941		return ret;
2942	}
2943	return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2944				       skb, msg_header);
2945}
2946
2947static ssize_t tcmu_emulate_write_cache_store(struct config_item *item,
2948					      const char *page, size_t count)
2949{
2950	struct se_dev_attrib *da = container_of(to_config_group(item),
2951					struct se_dev_attrib, da_group);
2952	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2953	u8 val;
2954	int ret;
2955
2956	ret = kstrtou8(page, 0, &val);
2957	if (ret < 0)
2958		return ret;
2959
2960	/* Check if device has been configured before */
2961	if (target_dev_configured(&udev->se_dev)) {
2962		ret = tcmu_send_emulate_write_cache(udev, val);
2963		if (ret) {
2964			pr_err("Unable to reconfigure device\n");
2965			return ret;
2966		}
2967	}
2968
2969	da->emulate_write_cache = val;
2970	return count;
2971}
2972CONFIGFS_ATTR(tcmu_, emulate_write_cache);
2973
2974static ssize_t tcmu_tmr_notification_show(struct config_item *item, char *page)
2975{
2976	struct se_dev_attrib *da = container_of(to_config_group(item),
2977					struct se_dev_attrib, da_group);
2978	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2979
2980	return snprintf(page, PAGE_SIZE, "%i\n",
2981			test_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags));
2982}
2983
2984static ssize_t tcmu_tmr_notification_store(struct config_item *item,
2985					   const char *page, size_t count)
2986{
2987	struct se_dev_attrib *da = container_of(to_config_group(item),
2988					struct se_dev_attrib, da_group);
2989	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2990	u8 val;
2991	int ret;
2992
2993	ret = kstrtou8(page, 0, &val);
2994	if (ret < 0)
2995		return ret;
2996	if (val > 1)
2997		return -EINVAL;
2998
2999	if (val)
3000		set_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags);
3001	else
3002		clear_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags);
3003	return count;
3004}
3005CONFIGFS_ATTR(tcmu_, tmr_notification);
3006
3007static ssize_t tcmu_block_dev_show(struct config_item *item, char *page)
3008{
3009	struct se_device *se_dev = container_of(to_config_group(item),
3010						struct se_device,
3011						dev_action_group);
3012	struct tcmu_dev *udev = TCMU_DEV(se_dev);
3013
3014	if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
3015		return snprintf(page, PAGE_SIZE, "%s\n", "blocked");
3016	else
3017		return snprintf(page, PAGE_SIZE, "%s\n", "unblocked");
3018}
3019
3020static ssize_t tcmu_block_dev_store(struct config_item *item, const char *page,
3021				    size_t count)
3022{
3023	struct se_device *se_dev = container_of(to_config_group(item),
3024						struct se_device,
3025						dev_action_group);
3026	struct tcmu_dev *udev = TCMU_DEV(se_dev);
3027	u8 val;
3028	int ret;
3029
3030	if (!target_dev_configured(&udev->se_dev)) {
3031		pr_err("Device is not configured.\n");
3032		return -EINVAL;
3033	}
3034
3035	ret = kstrtou8(page, 0, &val);
3036	if (ret < 0)
3037		return ret;
3038
3039	if (val > 1) {
3040		pr_err("Invalid block value %d\n", val);
3041		return -EINVAL;
3042	}
3043
3044	if (!val)
3045		tcmu_unblock_dev(udev);
3046	else
3047		tcmu_block_dev(udev);
3048	return count;
3049}
3050CONFIGFS_ATTR(tcmu_, block_dev);
3051
3052static ssize_t tcmu_reset_ring_store(struct config_item *item, const char *page,
3053				     size_t count)
3054{
3055	struct se_device *se_dev = container_of(to_config_group(item),
3056						struct se_device,
3057						dev_action_group);
3058	struct tcmu_dev *udev = TCMU_DEV(se_dev);
3059	u8 val;
3060	int ret;
3061
3062	if (!target_dev_configured(&udev->se_dev)) {
3063		pr_err("Device is not configured.\n");
3064		return -EINVAL;
3065	}
3066
3067	ret = kstrtou8(page, 0, &val);
3068	if (ret < 0)
3069		return ret;
3070
3071	if (val != 1 && val != 2) {
3072		pr_err("Invalid reset ring value %d\n", val);
3073		return -EINVAL;
3074	}
3075
3076	tcmu_reset_ring(udev, val);
3077	return count;
3078}
3079CONFIGFS_ATTR_WO(tcmu_, reset_ring);
3080
3081static ssize_t tcmu_free_kept_buf_store(struct config_item *item, const char *page,
3082					size_t count)
3083{
3084	struct se_device *se_dev = container_of(to_config_group(item),
3085						struct se_device,
3086						dev_action_group);
3087	struct tcmu_dev *udev = TCMU_DEV(se_dev);
3088	struct tcmu_cmd *cmd;
3089	u16 cmd_id;
3090	int ret;
3091
3092	if (!target_dev_configured(&udev->se_dev)) {
3093		pr_err("Device is not configured.\n");
3094		return -EINVAL;
3095	}
3096
3097	ret = kstrtou16(page, 0, &cmd_id);
3098	if (ret < 0)
3099		return ret;
3100
3101	mutex_lock(&udev->cmdr_lock);
3102
3103	{
3104		XA_STATE(xas, &udev->commands, cmd_id);
3105
3106		xas_lock(&xas);
3107		cmd = xas_load(&xas);
3108		if (!cmd) {
3109			pr_err("free_kept_buf: cmd_id %d not found\n", cmd_id);
3110			count = -EINVAL;
3111			xas_unlock(&xas);
3112			goto out_unlock;
3113		}
3114		if (!test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags)) {
3115			pr_err("free_kept_buf: cmd_id %d was not completed with KEEP_BUF\n",
3116			       cmd_id);
3117			count = -EINVAL;
3118			xas_unlock(&xas);
3119			goto out_unlock;
3120		}
3121		xas_store(&xas, NULL);
3122		xas_unlock(&xas);
3123	}
3124
3125	tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
3126	tcmu_free_cmd(cmd);
3127	/*
3128	 * We only freed data space, not ring space. Therefore we dont call
3129	 * run_tmr_queue, but call run_qfull_queue if tmr_list is empty.
3130	 */
3131	if (list_empty(&udev->tmr_queue))
3132		run_qfull_queue(udev, false);
3133
3134out_unlock:
3135	mutex_unlock(&udev->cmdr_lock);
3136	return count;
3137}
3138CONFIGFS_ATTR_WO(tcmu_, free_kept_buf);
3139
3140static struct configfs_attribute *tcmu_attrib_attrs[] = {
3141	&tcmu_attr_cmd_time_out,
3142	&tcmu_attr_qfull_time_out,
3143	&tcmu_attr_max_data_area_mb,
3144	&tcmu_attr_data_pages_per_blk,
3145	&tcmu_attr_cmd_ring_size_mb,
3146	&tcmu_attr_dev_config,
3147	&tcmu_attr_dev_size,
3148	&tcmu_attr_emulate_write_cache,
3149	&tcmu_attr_tmr_notification,
3150	&tcmu_attr_nl_reply_supported,
3151	NULL,
3152};
3153
3154static struct configfs_attribute **tcmu_attrs;
3155
3156static struct configfs_attribute *tcmu_action_attrs[] = {
3157	&tcmu_attr_block_dev,
3158	&tcmu_attr_reset_ring,
3159	&tcmu_attr_free_kept_buf,
3160	NULL,
3161};
3162
3163static struct target_backend_ops tcmu_ops = {
3164	.name			= "user",
3165	.owner			= THIS_MODULE,
3166	.transport_flags_default = TRANSPORT_FLAG_PASSTHROUGH,
3167	.transport_flags_changeable = TRANSPORT_FLAG_PASSTHROUGH_PGR |
3168				      TRANSPORT_FLAG_PASSTHROUGH_ALUA,
3169	.attach_hba		= tcmu_attach_hba,
3170	.detach_hba		= tcmu_detach_hba,
3171	.alloc_device		= tcmu_alloc_device,
3172	.configure_device	= tcmu_configure_device,
3173	.destroy_device		= tcmu_destroy_device,
3174	.free_device		= tcmu_free_device,
3175	.unplug_device		= tcmu_unplug_device,
3176	.plug_device		= tcmu_plug_device,
3177	.parse_cdb		= tcmu_parse_cdb,
3178	.tmr_notify		= tcmu_tmr_notify,
3179	.set_configfs_dev_params = tcmu_set_configfs_dev_params,
3180	.show_configfs_dev_params = tcmu_show_configfs_dev_params,
3181	.get_device_type	= sbc_get_device_type,
3182	.get_blocks		= tcmu_get_blocks,
3183	.tb_dev_action_attrs	= tcmu_action_attrs,
3184};
3185
3186static void find_free_blocks(void)
3187{
3188	struct tcmu_dev *udev;
3189	loff_t off;
3190	u32 pages_freed, total_pages_freed = 0;
3191	u32 start, end, block, total_blocks_freed = 0;
3192
3193	if (atomic_read(&global_page_count) <= tcmu_global_max_pages)
3194		return;
3195
3196	mutex_lock(&root_udev_mutex);
3197	list_for_each_entry(udev, &root_udev, node) {
3198		mutex_lock(&udev->cmdr_lock);
3199
3200		if (!target_dev_configured(&udev->se_dev)) {
3201			mutex_unlock(&udev->cmdr_lock);
3202			continue;
3203		}
3204
3205		/* Try to complete the finished commands first */
3206		if (tcmu_handle_completions(udev))
3207			run_qfull_queue(udev, false);
3208
3209		/* Skip the udevs in idle */
3210		if (!udev->dbi_thresh) {
3211			mutex_unlock(&udev->cmdr_lock);
3212			continue;
3213		}
3214
3215		end = udev->dbi_max + 1;
3216		block = find_last_bit(udev->data_bitmap, end);
3217		if (block == udev->dbi_max) {
3218			/*
3219			 * The last bit is dbi_max, so it is not possible
3220			 * reclaim any blocks.
3221			 */
3222			mutex_unlock(&udev->cmdr_lock);
3223			continue;
3224		} else if (block == end) {
3225			/* The current udev will goto idle state */
3226			udev->dbi_thresh = start = 0;
3227			udev->dbi_max = 0;
3228		} else {
3229			udev->dbi_thresh = start = block + 1;
3230			udev->dbi_max = block;
3231		}
3232
3233		/*
3234		 * Release the block pages.
3235		 *
3236		 * Also note that since tcmu_vma_fault() gets an extra page
3237		 * refcount, tcmu_blocks_release() won't free pages if pages
3238		 * are mapped. This means it is safe to call
3239		 * tcmu_blocks_release() before unmap_mapping_range() which
3240		 * drops the refcount of any pages it unmaps and thus releases
3241		 * them.
3242		 */
3243		pages_freed = tcmu_blocks_release(udev, start, end - 1);
3244
3245		/* Here will truncate the data area from off */
3246		off = udev->data_off + (loff_t)start * udev->data_blk_size;
3247		unmap_mapping_range(udev->inode->i_mapping, off, 0, 1);
3248
 
 
3249		mutex_unlock(&udev->cmdr_lock);
3250
3251		total_pages_freed += pages_freed;
3252		total_blocks_freed += end - start;
3253		pr_debug("Freed %u pages (total %u) from %u blocks (total %u) from %s.\n",
3254			 pages_freed, total_pages_freed, end - start,
3255			 total_blocks_freed, udev->name);
3256	}
3257	mutex_unlock(&root_udev_mutex);
3258
3259	if (atomic_read(&global_page_count) > tcmu_global_max_pages)
3260		schedule_delayed_work(&tcmu_unmap_work, msecs_to_jiffies(5000));
3261}
3262
3263static void check_timedout_devices(void)
3264{
3265	struct tcmu_dev *udev, *tmp_dev;
3266	struct tcmu_cmd *cmd, *tmp_cmd;
3267	LIST_HEAD(devs);
3268
3269	spin_lock_bh(&timed_out_udevs_lock);
3270	list_splice_init(&timed_out_udevs, &devs);
3271
3272	list_for_each_entry_safe(udev, tmp_dev, &devs, timedout_entry) {
3273		list_del_init(&udev->timedout_entry);
3274		spin_unlock_bh(&timed_out_udevs_lock);
3275
3276		mutex_lock(&udev->cmdr_lock);
3277
3278		/*
3279		 * If cmd_time_out is disabled but qfull is set deadline
3280		 * will only reflect the qfull timeout. Ignore it.
3281		 */
3282		if (udev->cmd_time_out) {
3283			list_for_each_entry_safe(cmd, tmp_cmd,
3284						 &udev->inflight_queue,
3285						 queue_entry) {
3286				tcmu_check_expired_ring_cmd(cmd);
3287			}
3288			tcmu_set_next_deadline(&udev->inflight_queue,
3289					       &udev->cmd_timer);
3290		}
3291		list_for_each_entry_safe(cmd, tmp_cmd, &udev->qfull_queue,
3292					 queue_entry) {
3293			tcmu_check_expired_queue_cmd(cmd);
3294		}
3295		tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
3296
3297		mutex_unlock(&udev->cmdr_lock);
3298
3299		spin_lock_bh(&timed_out_udevs_lock);
3300	}
3301
3302	spin_unlock_bh(&timed_out_udevs_lock);
3303}
3304
3305static void tcmu_unmap_work_fn(struct work_struct *work)
3306{
3307	check_timedout_devices();
3308	find_free_blocks();
3309}
3310
3311static int __init tcmu_module_init(void)
3312{
3313	int ret, i, k, len = 0;
3314
3315	BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry) % TCMU_OP_ALIGN_SIZE) != 0);
3316
3317	INIT_DELAYED_WORK(&tcmu_unmap_work, tcmu_unmap_work_fn);
3318
3319	tcmu_cmd_cache = kmem_cache_create("tcmu_cmd_cache",
3320				sizeof(struct tcmu_cmd),
3321				__alignof__(struct tcmu_cmd),
3322				0, NULL);
3323	if (!tcmu_cmd_cache)
3324		return -ENOMEM;
3325
3326	tcmu_root_device = root_device_register("tcm_user");
3327	if (IS_ERR(tcmu_root_device)) {
3328		ret = PTR_ERR(tcmu_root_device);
3329		goto out_free_cache;
3330	}
3331
3332	ret = genl_register_family(&tcmu_genl_family);
3333	if (ret < 0) {
3334		goto out_unreg_device;
3335	}
3336
3337	for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
3338		len += sizeof(struct configfs_attribute *);
3339	for (i = 0; passthrough_pr_attrib_attrs[i] != NULL; i++)
3340		len += sizeof(struct configfs_attribute *);
3341	for (i = 0; tcmu_attrib_attrs[i] != NULL; i++)
3342		len += sizeof(struct configfs_attribute *);
3343	len += sizeof(struct configfs_attribute *);
3344
3345	tcmu_attrs = kzalloc(len, GFP_KERNEL);
3346	if (!tcmu_attrs) {
3347		ret = -ENOMEM;
3348		goto out_unreg_genl;
3349	}
3350
3351	for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
3352		tcmu_attrs[i] = passthrough_attrib_attrs[i];
3353	for (k = 0; passthrough_pr_attrib_attrs[k] != NULL; k++)
3354		tcmu_attrs[i++] = passthrough_pr_attrib_attrs[k];
3355	for (k = 0; tcmu_attrib_attrs[k] != NULL; k++)
3356		tcmu_attrs[i++] = tcmu_attrib_attrs[k];
3357	tcmu_ops.tb_dev_attrib_attrs = tcmu_attrs;
3358
3359	ret = transport_backend_register(&tcmu_ops);
3360	if (ret)
3361		goto out_attrs;
3362
3363	return 0;
3364
3365out_attrs:
3366	kfree(tcmu_attrs);
3367out_unreg_genl:
3368	genl_unregister_family(&tcmu_genl_family);
3369out_unreg_device:
3370	root_device_unregister(tcmu_root_device);
3371out_free_cache:
3372	kmem_cache_destroy(tcmu_cmd_cache);
3373
3374	return ret;
3375}
3376
3377static void __exit tcmu_module_exit(void)
3378{
3379	cancel_delayed_work_sync(&tcmu_unmap_work);
3380	target_backend_unregister(&tcmu_ops);
3381	kfree(tcmu_attrs);
3382	genl_unregister_family(&tcmu_genl_family);
3383	root_device_unregister(tcmu_root_device);
3384	kmem_cache_destroy(tcmu_cmd_cache);
3385}
3386
3387MODULE_DESCRIPTION("TCM USER subsystem plugin");
3388MODULE_AUTHOR("Shaohua Li <shli@kernel.org>");
3389MODULE_AUTHOR("Andy Grover <agrover@redhat.com>");
3390MODULE_LICENSE("GPL");
3391
3392module_init(tcmu_module_init);
3393module_exit(tcmu_module_exit);