1	// SPDX-License-Identifier: GPL-2.0-only
2	/*
3	* Copyright (C) 2013 Shaohua Li <shli@kernel.org>
4	* Copyright (C) 2014 Red Hat, Inc.
5	* Copyright (C) 2015 Arrikto, Inc.
6	* Copyright (C) 2017 Chinamobile, Inc.
7	*/
8
9	#include <linux/spinlock.h>
10	#include <linux/module.h>
11	#include <linux/kernel.h>
12	#include <linux/timer.h>
13	#include <linux/parser.h>
14	#include <linux/vmalloc.h>
15	#include <linux/uio_driver.h>
16	#include <linux/xarray.h>
17	#include <linux/stringify.h>
18	#include <linux/bitops.h>
19	#include <linux/highmem.h>
20	#include <linux/configfs.h>
21	#include <linux/mutex.h>
22	#include <linux/workqueue.h>
23	#include <linux/pagemap.h>
24	#include <net/genetlink.h>
25	#include <scsi/scsi_common.h>
26	#include <scsi/scsi_proto.h>
27	#include <target/target_core_base.h>
28	#include <target/target_core_fabric.h>
29	#include <target/target_core_backend.h>
30
31	#include <linux/target_core_user.h>
32
33	/**
34	* DOC: Userspace I/O
35	* Userspace I/O
36	* -------------
37	*
38	* Define a shared-memory interface for LIO to pass SCSI commands and
39	* data to userspace for processing. This is to allow backends that
40	* are too complex for in-kernel support to be possible.
41	*
42	* It uses the UIO framework to do a lot of the device-creation and
43	* introspection work for us.
44	*
45	* See the .h file for how the ring is laid out. Note that while the
46	* command ring is defined, the particulars of the data area are
47	* not. Offset values in the command entry point to other locations
48	* internal to the mmap-ed area. There is separate space outside the
49	* command ring for data buffers. This leaves maximum flexibility for
50	* moving buffer allocations, or even page flipping or other
51	* allocation techniques, without altering the command ring layout.
52	*
53	* SECURITY:
54	* The user process must be assumed to be malicious. There's no way to
55	* prevent it breaking the command ring protocol if it wants, but in
56	* order to prevent other issues we must only ever read *data* from
57	* the shared memory area, not offsets or sizes. This applies to
58	* command ring entries as well as the mailbox. Extra code needed for
59	* this may have a 'UAM' comment.
60	*/
61
62	#define TCMU_TIME_OUT (30 * MSEC_PER_SEC)
63
64	/* For mailbox plus cmd ring, the size is fixed 8MB */
65	#define MB_CMDR_SIZE_DEF (8 * 1024 * 1024)
66	/* Offset of cmd ring is size of mailbox */
67	#define CMDR_OFF ((__u32)sizeof(struct tcmu_mailbox))
68	#define CMDR_SIZE_DEF (MB_CMDR_SIZE_DEF - CMDR_OFF)
69
70	/*
71	* For data area, the default block size is PAGE_SIZE and
72	* the default total size is 256K * PAGE_SIZE.
73	*/
74	#define DATA_PAGES_PER_BLK_DEF 1
75	#define DATA_AREA_PAGES_DEF (256 * 1024)
76
77	#define TCMU_MBS_TO_PAGES(_mbs) ((size_t)_mbs << (20 - PAGE_SHIFT))
78	#define TCMU_PAGES_TO_MBS(_pages) (_pages >> (20 - PAGE_SHIFT))
79
80	/*
81	* Default number of global data blocks(512K * PAGE_SIZE)
82	* when the unmap thread will be started.
83	*/
84	#define TCMU_GLOBAL_MAX_PAGES_DEF (512 * 1024)
85
86	static u8 tcmu_kern_cmd_reply_supported;
87	static u8 tcmu_netlink_blocked;
88
89	static struct device *tcmu_root_device;
90
91	struct tcmu_hba {
92	u32 host_id;
93	};
94
95	#define TCMU_CONFIG_LEN 256
96
97	static DEFINE_MUTEX(tcmu_nl_cmd_mutex);
98	static LIST_HEAD(tcmu_nl_cmd_list);
99
100	struct tcmu_dev;
101
102	struct tcmu_nl_cmd {
103	/* wake up thread waiting for reply */
104	struct completion complete;
105	struct list_head nl_list;
106	struct tcmu_dev *udev;
107	int cmd;
108	int status;
109	};
110
111	struct tcmu_dev {
112	struct list_head node;
113	struct kref kref;
114
115	struct se_device se_dev;
116	struct se_dev_plug se_plug;
117
118	char *name;
119	struct se_hba *hba;
120
121	#define TCMU_DEV_BIT_OPEN 0
122	#define TCMU_DEV_BIT_BROKEN 1
123	#define TCMU_DEV_BIT_BLOCKED 2
124	#define TCMU_DEV_BIT_TMR_NOTIFY 3
125	#define TCMU_DEV_BIT_PLUGGED 4
126	unsigned long flags;
127
128	struct uio_info uio_info;
129
130	struct inode *inode;
131
132	uint64_t dev_size;
133
134	struct tcmu_mailbox *mb_addr;
135	void *cmdr;
136	u32 cmdr_size;
137	u32 cmdr_last_cleaned;
138	/* Offset of data area from start of mb */
139	/* Must add data_off and mb_addr to get the address */
140	size_t data_off;
141	int data_area_mb;
142	uint32_t max_blocks;
143	size_t mmap_pages;
144
145	struct mutex cmdr_lock;
146	struct list_head qfull_queue;
147	struct list_head tmr_queue;
148
149	uint32_t dbi_max;
150	uint32_t dbi_thresh;
151	unsigned long *data_bitmap;
152	struct xarray data_pages;
153	uint32_t data_pages_per_blk;
154	uint32_t data_blk_size;
155
156	struct xarray commands;
157
158	struct timer_list cmd_timer;
159	unsigned int cmd_time_out;
160	struct list_head inflight_queue;
161
162	struct timer_list qfull_timer;
163	int qfull_time_out;
164
165	struct list_head timedout_entry;
166
167	struct tcmu_nl_cmd curr_nl_cmd;
168
169	char dev_config[TCMU_CONFIG_LEN];
170
171	int nl_reply_supported;
172	};
173
174	#define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev)
175
176	struct tcmu_cmd {
177	struct se_cmd *se_cmd;
178	struct tcmu_dev *tcmu_dev;
179	struct list_head queue_entry;
180
181	uint16_t cmd_id;
182
183	/* Can't use se_cmd when cleaning up expired cmds, because if
184	cmd has been completed then accessing se_cmd is off limits */
185	uint32_t dbi_cnt;
186	uint32_t dbi_bidi_cnt;
187	uint32_t dbi_cur;
188	uint32_t *dbi;
189
190	uint32_t data_len_bidi;
191
192	unsigned long deadline;
193
194	#define TCMU_CMD_BIT_EXPIRED 0
195	#define TCMU_CMD_BIT_KEEP_BUF 1
196	unsigned long flags;
197	};
198
199	struct tcmu_tmr {
200	struct list_head queue_entry;
201
202	uint8_t tmr_type;
203	uint32_t tmr_cmd_cnt;
204	int16_t tmr_cmd_ids[] __counted_by(tmr_cmd_cnt);
205	};
206
207	/*
208	* To avoid dead lock the mutex lock order should always be:
209	*
210	* mutex_lock(&root_udev_mutex);
211	* ...
212	* mutex_lock(&tcmu_dev->cmdr_lock);
213	* mutex_unlock(&tcmu_dev->cmdr_lock);
214	* ...
215	* mutex_unlock(&root_udev_mutex);
216	*/
217	static DEFINE_MUTEX(root_udev_mutex);
218	static LIST_HEAD(root_udev);
219
220	static DEFINE_SPINLOCK(timed_out_udevs_lock);
221	static LIST_HEAD(timed_out_udevs);
222
223	static struct kmem_cache *tcmu_cmd_cache;
224
225	static atomic_t global_page_count = ATOMIC_INIT(0);
226	static struct delayed_work tcmu_unmap_work;
227	static int tcmu_global_max_pages = TCMU_GLOBAL_MAX_PAGES_DEF;
228
229	static int tcmu_set_global_max_data_area(const char *str,
230	const struct kernel_param *kp)
231	{
232	int ret, max_area_mb;
233
234	ret = kstrtoint(s: str, base: 10, res: &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(v: &global_page_count) > tcmu_global_max_pages)
245	schedule_delayed_work(dwork: &tcmu_unmap_work, delay: 0);
246	else
247	cancel_delayed_work_sync(dwork: &tcmu_unmap_work);
248
249	return 0;
250	}
251
252	static int tcmu_get_global_max_data_area(char *buffer,
253	const struct kernel_param *kp)
254	{
255	return sprintf(buf: buffer, fmt: "%d\n", TCMU_PAGES_TO_MBS(tcmu_global_max_pages));
256	}
257
258	static const struct kernel_param_ops tcmu_global_max_data_area_op = {
259	.set = tcmu_set_global_max_data_area,
260	.get = tcmu_get_global_max_data_area,
261	};
262
263	module_param_cb(global_max_data_area_mb, &tcmu_global_max_data_area_op, NULL,
264	S_IWUSR | S_IRUGO);
265	MODULE_PARM_DESC(global_max_data_area_mb,
266	"Max MBs allowed to be allocated to all the tcmu device's "
267	"data areas.");
268
269	static int tcmu_get_block_netlink(char *buffer,
270	const struct kernel_param *kp)
271	{
272	return sprintf(buf: buffer, fmt: "%s\n", tcmu_netlink_blocked ?
273	"blocked" : "unblocked");
274	}
275
276	static int tcmu_set_block_netlink(const char *str,
277	const struct kernel_param *kp)
278	{
279	int ret;
280	u8 val;
281
282	ret = kstrtou8(s: str, base: 0, res: &val);
283	if (ret < 0)
284	return ret;
285
286	if (val > 1) {
287	pr_err("Invalid block netlink value %u\n", val);
288	return -EINVAL;
289	}
290
291	tcmu_netlink_blocked = val;
292	return 0;
293	}
294
295	static const struct kernel_param_ops tcmu_block_netlink_op = {
296	.set = tcmu_set_block_netlink,
297	.get = tcmu_get_block_netlink,
298	};
299
300	module_param_cb(block_netlink, &tcmu_block_netlink_op, NULL, S_IWUSR | S_IRUGO);
301	MODULE_PARM_DESC(block_netlink, "Block new netlink commands.");
302
303	static int tcmu_fail_netlink_cmd(struct tcmu_nl_cmd *nl_cmd)
304	{
305	struct tcmu_dev *udev = nl_cmd->udev;
306
307	if (!tcmu_netlink_blocked) {
308	pr_err("Could not reset device's netlink interface. Netlink is not blocked.\n");
309	return -EBUSY;
310	}
311
312	if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
313	pr_debug("Aborting nl cmd %d on %s\n", nl_cmd->cmd, udev->name);
314	nl_cmd->status = -EINTR;
315	list_del(entry: &nl_cmd->nl_list);
316	complete(&nl_cmd->complete);
317	}
318	return 0;
319	}
320
321	static int tcmu_set_reset_netlink(const char *str,
322	const struct kernel_param *kp)
323	{
324	struct tcmu_nl_cmd *nl_cmd, *tmp_cmd;
325	int ret;
326	u8 val;
327
328	ret = kstrtou8(s: str, base: 0, res: &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(lock: &tcmu_nl_cmd_mutex);
344
345	return ret;
346	}
347
348	static const struct kernel_param_ops tcmu_reset_netlink_op = {
349	.set = tcmu_set_reset_netlink,
350	};
351
352	module_param_cb(reset_netlink, &tcmu_reset_netlink_op, NULL, S_IWUSR);
353	MODULE_PARM_DESC(reset_netlink, "Reset netlink commands.");
354
355	/* multicast group */
356	enum tcmu_multicast_groups {
357	TCMU_MCGRP_CONFIG,
358	};
359
360	static const struct genl_multicast_group tcmu_mcgrps[] = {
361	[TCMU_MCGRP_CONFIG] = { .name = "config", },
362	};
363
364	static 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
372	static int tcmu_genl_cmd_done(struct genl_info *info, int completed_cmd)
373	{
374	struct tcmu_dev *udev = NULL;
375	struct tcmu_nl_cmd *nl_cmd;
376	int dev_id, rc, ret = 0;
377
378	if (!info->attrs[TCMU_ATTR_CMD_STATUS] ||
379	!info->attrs[TCMU_ATTR_DEVICE_ID]) {
380	printk(KERN_ERR "TCMU_ATTR_CMD_STATUS or TCMU_ATTR_DEVICE_ID not set, doing nothing\n");
381	return -EINVAL;
382	}
383
384	dev_id = nla_get_u32(nla: info->attrs[TCMU_ATTR_DEVICE_ID]);
385	rc = nla_get_s32(nla: 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(entry: &nl_cmd->nl_list);
402
403	pr_debug("%s genl cmd done got id %d curr %d done %d rc %d stat %d\n",
404	udev->name, dev_id, nl_cmd->cmd, completed_cmd, rc,
405	nl_cmd->status);
406
407	if (nl_cmd->cmd != completed_cmd) {
408	pr_err("Mismatched commands on %s (Expecting reply for %d. Current %d).\n",
409	udev->name, completed_cmd, nl_cmd->cmd);
410	ret = -EINVAL;
411	goto unlock;
412	}
413
414	nl_cmd->status = rc;
415	complete(&nl_cmd->complete);
416	unlock:
417	mutex_unlock(lock: &tcmu_nl_cmd_mutex);
418	return ret;
419	}
420
421	static int tcmu_genl_rm_dev_done(struct sk_buff *skb, struct genl_info *info)
422	{
423	return tcmu_genl_cmd_done(info, completed_cmd: TCMU_CMD_REMOVED_DEVICE);
424	}
425
426	static int tcmu_genl_add_dev_done(struct sk_buff *skb, struct genl_info *info)
427	{
428	return tcmu_genl_cmd_done(info, completed_cmd: TCMU_CMD_ADDED_DEVICE);
429	}
430
431	static int tcmu_genl_reconfig_dev_done(struct sk_buff *skb,
432	struct genl_info *info)
433	{
434	return tcmu_genl_cmd_done(info, completed_cmd: TCMU_CMD_RECONFIG_DEVICE);
435	}
436
437	static int tcmu_genl_set_features(struct sk_buff *skb, struct genl_info *info)
438	{
439	if (info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]) {
440	tcmu_kern_cmd_reply_supported =
441	nla_get_u8(nla: info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]);
442	printk(KERN_INFO "tcmu daemon: command reply support %u.\n",
443	tcmu_kern_cmd_reply_supported);
444	}
445
446	return 0;
447	}
448
449	static const struct genl_small_ops tcmu_genl_ops[] = {
450	{
451	.cmd = TCMU_CMD_SET_FEATURES,
452	.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
453	.flags = GENL_ADMIN_PERM,
454	.doit = tcmu_genl_set_features,
455	},
456	{
457	.cmd = TCMU_CMD_ADDED_DEVICE_DONE,
458	.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
459	.flags = GENL_ADMIN_PERM,
460	.doit = tcmu_genl_add_dev_done,
461	},
462	{
463	.cmd = TCMU_CMD_REMOVED_DEVICE_DONE,
464	.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
465	.flags = GENL_ADMIN_PERM,
466	.doit = tcmu_genl_rm_dev_done,
467	},
468	{
469	.cmd = TCMU_CMD_RECONFIG_DEVICE_DONE,
470	.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
471	.flags = GENL_ADMIN_PERM,
472	.doit = tcmu_genl_reconfig_dev_done,
473	},
474	};
475
476	/* Our generic netlink family */
477	static struct genl_family tcmu_genl_family __ro_after_init = {
478	.module = THIS_MODULE,
479	.hdrsize = 0,
480	.name = "TCM-USER",
481	.version = 2,
482	.maxattr = TCMU_ATTR_MAX,
483	.policy = tcmu_attr_policy,
484	.mcgrps = tcmu_mcgrps,
485	.n_mcgrps = ARRAY_SIZE(tcmu_mcgrps),
486	.netnsok = true,
487	.small_ops = tcmu_genl_ops,
488	.n_small_ops = ARRAY_SIZE(tcmu_genl_ops),
489	.resv_start_op = TCMU_CMD_SET_FEATURES + 1,
490	};
491
492	#define tcmu_cmd_set_dbi_cur(cmd, index) ((cmd)->dbi_cur = (index))
493	#define tcmu_cmd_reset_dbi_cur(cmd) tcmu_cmd_set_dbi_cur(cmd, 0)
494	#define tcmu_cmd_set_dbi(cmd, index) ((cmd)->dbi[(cmd)->dbi_cur++] = (index))
495	#define tcmu_cmd_get_dbi(cmd) ((cmd)->dbi[(cmd)->dbi_cur++])
496
497	static void tcmu_cmd_free_data(struct tcmu_cmd *tcmu_cmd, uint32_t len)
498	{
499	struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
500	uint32_t i;
501
502	for (i = 0; i < len; i++)
503	clear_bit(nr: tcmu_cmd->dbi[i], addr: udev->data_bitmap);
504	}
505
506	static inline int tcmu_get_empty_block(struct tcmu_dev *udev,
507	struct tcmu_cmd *tcmu_cmd,
508	int prev_dbi, int length, int *iov_cnt)
509	{
510	XA_STATE(xas, &udev->data_pages, 0);
511	struct page *page;
512	int i, cnt, dbi, dpi;
513	int page_cnt = DIV_ROUND_UP(length, PAGE_SIZE);
514
515	dbi = find_first_zero_bit(addr: udev->data_bitmap, size: 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: &xas, index: dpi);
522	rcu_read_lock();
523	for (cnt = 0; xas_next(xas: &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, index: dpi + i, entry: page, GFP_NOIO)) {
534	__free_page(page);
535	break;
536	}
537	}
538	if (atomic_add_return(i: i - cnt, v: &global_page_count) >
539	tcmu_global_max_pages)
540	schedule_delayed_work(dwork: &tcmu_unmap_work, delay: 0);
541
542	if (i && dbi > udev->dbi_max)
543	udev->dbi_max = dbi;
544
545	set_bit(nr: dbi, addr: udev->data_bitmap);
546	tcmu_cmd_set_dbi(tcmu_cmd, dbi);
547
548	if (dbi != prev_dbi + 1)
549	*iov_cnt += 1;
550
551	return i == page_cnt ? dbi : -1;
552	}
553
554	static int tcmu_get_empty_blocks(struct tcmu_dev *udev,
555	struct tcmu_cmd *tcmu_cmd, int length)
556	{
557	/* start value of dbi + 1 must not be a valid dbi */
558	int dbi = -2;
559	int blk_data_len, iov_cnt = 0;
560	uint32_t blk_size = udev->data_blk_size;
561
562	for (; length > 0; length -= blk_size) {
563	blk_data_len = min_t(uint32_t, length, blk_size);
564	dbi = tcmu_get_empty_block(udev, tcmu_cmd, prev_dbi: dbi, length: blk_data_len,
565	iov_cnt: &iov_cnt);
566	if (dbi < 0)
567	return -1;
568	}
569	return iov_cnt;
570	}
571
572	static inline void tcmu_free_cmd(struct tcmu_cmd *tcmu_cmd)
573	{
574	kfree(objp: tcmu_cmd->dbi);
575	kmem_cache_free(s: tcmu_cmd_cache, objp: tcmu_cmd);
576	}
577
578	static inline void tcmu_cmd_set_block_cnts(struct tcmu_cmd *cmd)
579	{
580	int i, len;
581	struct se_cmd *se_cmd = cmd->se_cmd;
582	uint32_t blk_size = cmd->tcmu_dev->data_blk_size;
583
584	cmd->dbi_cnt = DIV_ROUND_UP(se_cmd->data_length, blk_size);
585
586	if (se_cmd->se_cmd_flags & SCF_BIDI) {
587	BUG_ON(!(se_cmd->t_bidi_data_sg && se_cmd->t_bidi_data_nents));
588	for (i = 0, len = 0; i < se_cmd->t_bidi_data_nents; i++)
589	len += se_cmd->t_bidi_data_sg[i].length;
590	cmd->dbi_bidi_cnt = DIV_ROUND_UP(len, blk_size);
591	cmd->dbi_cnt += cmd->dbi_bidi_cnt;
592	cmd->data_len_bidi = len;
593	}
594	}
595
596	static int new_block_to_iov(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
597	struct iovec **iov, int prev_dbi, int len)
598	{
599	/* Get the next dbi */
600	int dbi = tcmu_cmd_get_dbi(cmd);
601
602	/* Do not add more than udev->data_blk_size to iov */
603	len = min_t(int, len, udev->data_blk_size);
604
605	/*
606	* The following code will gather and map the blocks to the same iovec
607	* when the blocks are all next to each other.
608	*/
609	if (dbi != prev_dbi + 1) {
610	/* dbi is not next to previous dbi, so start new iov */
611	if (prev_dbi >= 0)
612	(*iov)++;
613	/* write offset relative to mb_addr */
614	(*iov)->iov_base = (void __user *)
615	(udev->data_off + dbi * udev->data_blk_size);
616	}
617	(*iov)->iov_len += len;
618
619	return dbi;
620	}
621
622	static void tcmu_setup_iovs(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
623	struct iovec **iov, int data_length)
624	{
625	/* start value of dbi + 1 must not be a valid dbi */
626	int dbi = -2;
627
628	/* We prepare the IOVs for DMA_FROM_DEVICE transfer direction */
629	for (; data_length > 0; data_length -= udev->data_blk_size)
630	dbi = new_block_to_iov(udev, cmd, iov, prev_dbi: dbi, len: data_length);
631	}
632
633	static struct tcmu_cmd *tcmu_alloc_cmd(struct se_cmd *se_cmd)
634	{
635	struct se_device *se_dev = se_cmd->se_dev;
636	struct tcmu_dev *udev = TCMU_DEV(se_dev);
637	struct tcmu_cmd *tcmu_cmd;
638
639	tcmu_cmd = kmem_cache_zalloc(tcmu_cmd_cache, GFP_NOIO);
640	if (!tcmu_cmd)
641	return NULL;
642
643	INIT_LIST_HEAD(list: &tcmu_cmd->queue_entry);
644	tcmu_cmd->se_cmd = se_cmd;
645	tcmu_cmd->tcmu_dev = udev;
646
647	tcmu_cmd_set_block_cnts(cmd: 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(s: tcmu_cmd_cache, objp: tcmu_cmd);
652	return NULL;
653	}
654
655	return tcmu_cmd;
656	}
657
658	static inline void tcmu_flush_dcache_range(void *vaddr, size_t size)
659	{
660	unsigned long offset = offset_in_page(vaddr);
661	void *start = vaddr - offset;
662
663	size = round_up(size+offset, PAGE_SIZE);
664
665	while (size) {
666	flush_dcache_page(page: vmalloc_to_page(addr: start));
667	start += PAGE_SIZE;
668	size -= PAGE_SIZE;
669	}
670	}
671
672	/*
673	* Some ring helper functions. We don't assume size is a power of 2 so
674	* we can't use circ_buf.h.
675	*/
676	static inline size_t spc_used(size_t head, size_t tail, size_t size)
677	{
678	int diff = head - tail;
679
680	if (diff >= 0)
681	return diff;
682	else
683	return size + diff;
684	}
685
686	static inline size_t spc_free(size_t head, size_t tail, size_t size)
687	{
688	/* Keep 1 byte unused or we can't tell full from empty */
689	return (size - spc_used(head, tail, size) - 1);
690	}
691
692	static inline size_t head_to_end(size_t head, size_t size)
693	{
694	return size - head;
695	}
696
697	#define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size)
698
699	#define TCMU_SG_TO_DATA_AREA 1
700	#define TCMU_DATA_AREA_TO_SG 2
701
702	static inline void tcmu_copy_data(struct tcmu_dev *udev,
703	struct tcmu_cmd *tcmu_cmd, uint32_t direction,
704	struct scatterlist *sg, unsigned int sg_nents,
705	struct iovec **iov, size_t data_len)
706	{
707	/* start value of dbi + 1 must not be a valid dbi */
708	int dbi = -2;
709	size_t page_remaining, cp_len;
710	int page_cnt, page_inx, dpi;
711	struct sg_mapping_iter sg_iter;
712	unsigned int sg_flags;
713	struct page *page;
714	void *data_page_start, *data_addr;
715
716	if (direction == TCMU_SG_TO_DATA_AREA)
717	sg_flags = SG_MITER_ATOMIC | SG_MITER_FROM_SG;
718	else
719	sg_flags = SG_MITER_ATOMIC | SG_MITER_TO_SG;
720	sg_miter_start(miter: &sg_iter, sgl: sg, nents: sg_nents, flags: sg_flags);
721
722	while (data_len) {
723	if (direction == TCMU_SG_TO_DATA_AREA)
724	dbi = new_block_to_iov(udev, cmd: tcmu_cmd, iov, prev_dbi: dbi,
725	len: 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, index: 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(miter: &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(miter: &sg_iter);
766
767	kunmap_atomic(data_page_start);
768	if (direction == TCMU_SG_TO_DATA_AREA)
769	flush_dcache_page(page);
770	}
771	}
772	}
773
774	static void scatter_data_area(struct tcmu_dev *udev, struct tcmu_cmd *tcmu_cmd,
775	struct iovec **iov)
776	{
777	struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
778
779	tcmu_copy_data(udev, tcmu_cmd, TCMU_SG_TO_DATA_AREA, sg: se_cmd->t_data_sg,
780	sg_nents: se_cmd->t_data_nents, iov, data_len: se_cmd->data_length);
781	}
782
783	static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *tcmu_cmd,
784	bool bidi, uint32_t read_len)
785	{
786	struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
787	struct scatterlist *data_sg;
788	unsigned int data_nents;
789
790	if (!bidi) {
791	data_sg = se_cmd->t_data_sg;
792	data_nents = se_cmd->t_data_nents;
793	} else {
794	/*
795	* For bidi case, the first count blocks are for Data-Out
796	* buffer blocks, and before gathering the Data-In buffer
797	* the Data-Out buffer blocks should be skipped.
798	*/
799	tcmu_cmd_set_dbi_cur(tcmu_cmd,
800	tcmu_cmd->dbi_cnt - tcmu_cmd->dbi_bidi_cnt);
801
802	data_sg = se_cmd->t_bidi_data_sg;
803	data_nents = se_cmd->t_bidi_data_nents;
804	}
805
806	tcmu_copy_data(udev, tcmu_cmd, TCMU_DATA_AREA_TO_SG, sg: data_sg,
807	sg_nents: data_nents, NULL, data_len: read_len);
808	}
809
810	static inline size_t spc_bitmap_free(unsigned long *bitmap, uint32_t thresh)
811	{
812	return thresh - bitmap_weight(src: bitmap, nbits: thresh);
813	}
814
815	/*
816	* We can't queue a command until we have space available on the cmd ring.
817	*
818	* Called with ring lock held.
819	*/
820	static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size)
821	{
822	struct tcmu_mailbox *mb = udev->mb_addr;
823	size_t space, cmd_needed;
824	u32 cmd_head;
825
826	tcmu_flush_dcache_range(vaddr: mb, size: 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(head: cmd_head, size: udev->cmdr_size) >= cmd_size)
835	cmd_needed = cmd_size;
836	else
837	cmd_needed = cmd_size + head_to_end(head: cmd_head, size: udev->cmdr_size);
838
839	space = spc_free(head: cmd_head, tail: udev->cmdr_last_cleaned, size: udev->cmdr_size);
840	if (space < cmd_needed) {
841	pr_debug("no cmd space: %u %u %u\n", cmd_head,
842	udev->cmdr_last_cleaned, udev->cmdr_size);
843	return false;
844	}
845	return true;
846	}
847
848	/*
849	* We have to allocate data buffers before we can queue a command.
850	* Returns -1 on error (not enough space) or number of needed iovs on success
851	*
852	* Called with ring lock held.
853	*/
854	static int tcmu_alloc_data_space(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
855	int *iov_bidi_cnt)
856	{
857	int space, iov_cnt = 0, ret = 0;
858
859	if (!cmd->dbi_cnt)
860	goto wr_iov_cnts;
861
862	/* try to check and get the data blocks as needed */
863	space = spc_bitmap_free(bitmap: udev->data_bitmap, thresh: 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, tcmu_cmd: cmd, length: 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, tcmu_cmd: cmd, length: cmd->data_len_bidi);
886	if (ret < 0)
887	return -1;
888	}
889	wr_iov_cnts:
890	*iov_bidi_cnt = ret;
891	return iov_cnt + ret;
892	}
893
894	static inline size_t tcmu_cmd_get_base_cmd_size(size_t iov_cnt)
895	{
896	return max(offsetof(struct tcmu_cmd_entry, req.iov[iov_cnt]),
897	sizeof(struct tcmu_cmd_entry));
898	}
899
900	static inline size_t tcmu_cmd_get_cmd_size(struct tcmu_cmd *tcmu_cmd,
901	size_t base_command_size)
902	{
903	struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
904	size_t command_size;
905
906	command_size = base_command_size +
907	round_up(scsi_command_size(se_cmd->t_task_cdb),
908	TCMU_OP_ALIGN_SIZE);
909
910	WARN_ON(command_size & (TCMU_OP_ALIGN_SIZE-1));
911
912	return command_size;
913	}
914
915	static void tcmu_setup_cmd_timer(struct tcmu_cmd *tcmu_cmd, unsigned int tmo,
916	struct timer_list *timer)
917	{
918	if (!tmo)
919	return;
920
921	tcmu_cmd->deadline = round_jiffies_up(j: jiffies + msecs_to_jiffies(m: tmo));
922	if (!timer_pending(timer))
923	mod_timer(timer, expires: tcmu_cmd->deadline);
924
925	pr_debug("Timeout set up for cmd %p, dev = %s, tmo = %lu\n", tcmu_cmd,
926	tcmu_cmd->tcmu_dev->name, tmo / MSEC_PER_SEC);
927	}
928
929	static int add_to_qfull_queue(struct tcmu_cmd *tcmu_cmd)
930	{
931	struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
932	unsigned int tmo;
933
934	/*
935	* For backwards compat if qfull_time_out is not set use
936	* cmd_time_out and if that's not set use the default time out.
937	*/
938	if (!udev->qfull_time_out)
939	return -ETIMEDOUT;
940	else if (udev->qfull_time_out > 0)
941	tmo = udev->qfull_time_out;
942	else if (udev->cmd_time_out)
943	tmo = udev->cmd_time_out;
944	else
945	tmo = TCMU_TIME_OUT;
946
947	tcmu_setup_cmd_timer(tcmu_cmd, tmo, timer: &udev->qfull_timer);
948
949	list_add_tail(new: &tcmu_cmd->queue_entry, head: &udev->qfull_queue);
950	pr_debug("adding cmd %p on dev %s to ring space wait queue\n",
951	tcmu_cmd, udev->name);
952	return 0;
953	}
954
955	static uint32_t ring_insert_padding(struct tcmu_dev *udev, size_t cmd_size)
956	{
957	struct tcmu_cmd_entry_hdr *hdr;
958	struct tcmu_mailbox *mb = udev->mb_addr;
959	uint32_t cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
960
961	/* Insert a PAD if end-of-ring space is too small */
962	if (head_to_end(head: cmd_head, size: udev->cmdr_size) < cmd_size) {
963	size_t pad_size = head_to_end(head: cmd_head, size: udev->cmdr_size);
964
965	hdr = udev->cmdr + cmd_head;
966	tcmu_hdr_set_op(len_op: &hdr->len_op, op: TCMU_OP_PAD);
967	tcmu_hdr_set_len(len_op: &hdr->len_op, len: pad_size);
968	hdr->cmd_id = 0; /* not used for PAD */
969	hdr->kflags = 0;
970	hdr->uflags = 0;
971	tcmu_flush_dcache_range(vaddr: hdr, size: sizeof(*hdr));
972
973	UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size);
974	tcmu_flush_dcache_range(vaddr: mb, size: sizeof(*mb));
975
976	cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
977	WARN_ON(cmd_head != 0);
978	}
979
980	return cmd_head;
981	}
982
983	static void tcmu_unplug_device(struct se_dev_plug *se_plug)
984	{
985	struct se_device *se_dev = se_plug->se_dev;
986	struct tcmu_dev *udev = TCMU_DEV(se_dev);
987
988	clear_bit(TCMU_DEV_BIT_PLUGGED, addr: &udev->flags);
989	uio_event_notify(info: &udev->uio_info);
990	}
991
992	static struct se_dev_plug *tcmu_plug_device(struct se_device *se_dev)
993	{
994	struct tcmu_dev *udev = TCMU_DEV(se_dev);
995
996	if (!test_and_set_bit(TCMU_DEV_BIT_PLUGGED, addr: &udev->flags))
997	return &udev->se_plug;
998
999	return NULL;
1000	}
1001
1002	/**
1003	* queue_cmd_ring - queue cmd to ring or internally
1004	* @tcmu_cmd: cmd to queue
1005	* @scsi_err: TCM error code if failure (-1) returned.
1006	*
1007	* Returns:
1008	* -1 we cannot queue internally or to the ring.
1009	* 0 success
1010	* 1 internally queued to wait for ring memory to free.
1011	*/
1012	static int queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, sense_reason_t *scsi_err)
1013	{
1014	struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
1015	struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
1016	size_t base_command_size, command_size;
1017	struct tcmu_mailbox *mb = udev->mb_addr;
1018	struct tcmu_cmd_entry *entry;
1019	struct iovec *iov;
1020	int iov_cnt, iov_bidi_cnt;
1021	uint32_t cmd_id, cmd_head;
1022	uint64_t cdb_off;
1023	uint32_t blk_size = udev->data_blk_size;
1024	/* size of data buffer needed */
1025	size_t data_length = (size_t)tcmu_cmd->dbi_cnt * blk_size;
1026
1027	*scsi_err = TCM_NO_SENSE;
1028
1029	if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags)) {
1030	*scsi_err = TCM_LUN_BUSY;
1031	return -1;
1032	}
1033
1034	if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
1035	*scsi_err = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1036	return -1;
1037	}
1038
1039	if (!list_empty(head: &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, cmd: tcmu_cmd, iov_bidi_cnt: &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, len: tcmu_cmd->dbi_cur);
1064	*scsi_err = TCM_INVALID_CDB_FIELD;
1065	return -1;
1066	}
1067
1068	if (!is_ring_space_avail(udev, cmd_size: 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(xa: &udev->commands, id: &cmd_id, entry: 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, len: 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, cmd_size: command_size);
1089
1090	entry = udev->cmdr + cmd_head;
1091	memset(entry, 0, command_size);
1092	tcmu_hdr_set_op(len_op: &entry->hdr.len_op, 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: &iov);
1101	else
1102	tcmu_setup_iovs(udev, cmd: tcmu_cmd, iov: &iov, data_length: 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, cmd: tcmu_cmd, iov: &iov, data_length: tcmu_cmd->data_len_bidi);
1110	entry->req.iov_bidi_cnt = iov_bidi_cnt;
1111	}
1112
1113	tcmu_setup_cmd_timer(tcmu_cmd, tmo: udev->cmd_time_out, timer: &udev->cmd_timer);
1114
1115	entry->hdr.cmd_id = tcmu_cmd->cmd_id;
1116
1117	tcmu_hdr_set_len(len_op: &entry->hdr.len_op, len: 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(vaddr: entry, size: command_size);
1124
1125	UPDATE_HEAD(mb->cmd_head, command_size, udev->cmdr_size);
1126	tcmu_flush_dcache_range(vaddr: mb, size: sizeof(*mb));
1127
1128	list_add_tail(new: &tcmu_cmd->queue_entry, head: &udev->inflight_queue);
1129
1130	if (!test_bit(TCMU_DEV_BIT_PLUGGED, &udev->flags))
1131	uio_event_notify(info: &udev->uio_info);
1132
1133	return 0;
1134
1135	free_and_queue:
1136	tcmu_cmd_free_data(tcmu_cmd, len: tcmu_cmd->dbi_cur);
1137	tcmu_cmd_reset_dbi_cur(tcmu_cmd);
1138
1139	queue:
1140	if (add_to_qfull_queue(tcmu_cmd)) {
1141	*scsi_err = TCM_OUT_OF_RESOURCES;
1142	return -1;
1143	}
1144
1145	return 1;
1146	}
1147
1148	/**
1149	* queue_tmr_ring - queue tmr info to ring or internally
1150	* @udev: related tcmu_dev
1151	* @tmr: tcmu_tmr containing tmr info to queue
1152	*
1153	* Returns:
1154	* 0 success
1155	* 1 internally queued to wait for ring memory to free.
1156	*/
1157	static int
1158	queue_tmr_ring(struct tcmu_dev *udev, struct tcmu_tmr *tmr)
1159	{
1160	struct tcmu_tmr_entry *entry;
1161	int cmd_size;
1162	int id_list_sz;
1163	struct tcmu_mailbox *mb = udev->mb_addr;
1164	uint32_t cmd_head;
1165
1166	if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags))
1167	goto out_free;
1168
1169	id_list_sz = sizeof(tmr->tmr_cmd_ids[0]) * tmr->tmr_cmd_cnt;
1170	cmd_size = round_up(sizeof(*entry) + id_list_sz, TCMU_OP_ALIGN_SIZE);
1171
1172	if (!list_empty(head: &udev->tmr_queue) ||
1173	!is_ring_space_avail(udev, cmd_size)) {
1174	list_add_tail(new: &tmr->queue_entry, head: &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(len_op: &entry->hdr.len_op, op: TCMU_OP_TMR);
1185	tcmu_hdr_set_len(len_op: &entry->hdr.len_op, len: 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(vaddr: entry, size: cmd_size);
1190
1191	UPDATE_HEAD(mb->cmd_head, cmd_size, udev->cmdr_size);
1192	tcmu_flush_dcache_range(vaddr: mb, size: sizeof(*mb));
1193
1194	uio_event_notify(info: &udev->uio_info);
1195
1196	out_free:
1197	kfree(objp: tmr);
1198
1199	return 0;
1200	}
1201
1202	static sense_reason_t
1203	tcmu_queue_cmd(struct se_cmd *se_cmd)
1204	{
1205	struct se_device *se_dev = se_cmd->se_dev;
1206	struct tcmu_dev *udev = TCMU_DEV(se_dev);
1207	struct tcmu_cmd *tcmu_cmd;
1208	sense_reason_t scsi_ret = TCM_CHECK_CONDITION_ABORT_CMD;
1209	int ret = -1;
1210
1211	tcmu_cmd = tcmu_alloc_cmd(se_cmd);
1212	if (!tcmu_cmd)
1213	return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1214
1215	mutex_lock(&udev->cmdr_lock);
1216	if (!(se_cmd->transport_state & CMD_T_ABORTED))
1217	ret = queue_cmd_ring(tcmu_cmd, scsi_err: &scsi_ret);
1218	if (ret < 0)
1219	tcmu_free_cmd(tcmu_cmd);
1220	else
1221	se_cmd->priv = tcmu_cmd;
1222	mutex_unlock(lock: &udev->cmdr_lock);
1223	return scsi_ret;
1224	}
1225
1226	static void tcmu_set_next_deadline(struct list_head *queue,
1227	struct timer_list *timer)
1228	{
1229	struct tcmu_cmd *cmd;
1230
1231	if (!list_empty(head: queue)) {
1232	cmd = list_first_entry(queue, struct tcmu_cmd, queue_entry);
1233	mod_timer(timer, expires: cmd->deadline);
1234	} else
1235	timer_delete(timer);
1236	}
1237
1238	static int
1239	tcmu_tmr_type(enum tcm_tmreq_table tmf)
1240	{
1241	switch (tmf) {
1242	case TMR_ABORT_TASK: return TCMU_TMR_ABORT_TASK;
1243	case TMR_ABORT_TASK_SET: return TCMU_TMR_ABORT_TASK_SET;
1244	case TMR_CLEAR_ACA: return TCMU_TMR_CLEAR_ACA;
1245	case TMR_CLEAR_TASK_SET: return TCMU_TMR_CLEAR_TASK_SET;
1246	case TMR_LUN_RESET: return TCMU_TMR_LUN_RESET;
1247	case TMR_TARGET_WARM_RESET: return TCMU_TMR_TARGET_WARM_RESET;
1248	case TMR_TARGET_COLD_RESET: return TCMU_TMR_TARGET_COLD_RESET;
1249	case TMR_LUN_RESET_PRO: return TCMU_TMR_LUN_RESET_PRO;
1250	default: return TCMU_TMR_UNKNOWN;
1251	}
1252	}
1253
1254	static void
1255	tcmu_tmr_notify(struct se_device *se_dev, enum tcm_tmreq_table tmf,
1256	struct list_head *cmd_list)
1257	{
1258	int i = 0, cmd_cnt = 0;
1259	bool unqueued = false;
1260	struct tcmu_cmd *cmd;
1261	struct se_cmd *se_cmd;
1262	struct tcmu_tmr *tmr;
1263	struct tcmu_dev *udev = TCMU_DEV(se_dev);
1264
1265	mutex_lock(&udev->cmdr_lock);
1266
1267	/* First we check for aborted commands in qfull_queue */
1268	list_for_each_entry(se_cmd, cmd_list, state_list) {
1269	i++;
1270	if (!se_cmd->priv)
1271	continue;
1272	cmd = se_cmd->priv;
1273	/* Commands on qfull queue have no id yet */
1274	if (cmd->cmd_id) {
1275	cmd_cnt++;
1276	continue;
1277	}
1278	pr_debug("Removing aborted command %p from queue on dev %s.\n",
1279	cmd, udev->name);
1280
1281	list_del_init(entry: &cmd->queue_entry);
1282	tcmu_free_cmd(tcmu_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(queue: &udev->qfull_queue, timer: &udev->qfull_timer);
1289
1290	if (!test_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags))
1291	goto unlock;
1292
1293	pr_debug("TMR event %d on dev %s, aborted cmds %d, afflicted cmd_ids %d\n",
1294	tcmu_tmr_type(tmf), udev->name, i, cmd_cnt);
1295
1296	tmr = kmalloc(struct_size(tmr, tmr_cmd_ids, cmd_cnt), GFP_NOIO);
1297	if (!tmr)
1298	goto unlock;
1299
1300	tmr->tmr_type = tcmu_tmr_type(tmf);
1301	tmr->tmr_cmd_cnt = cmd_cnt;
1302
1303	if (cmd_cnt != 0) {
1304	cmd_cnt = 0;
1305	list_for_each_entry(se_cmd, cmd_list, state_list) {
1306	if (!se_cmd->priv)
1307	continue;
1308	cmd = se_cmd->priv;
1309	if (cmd->cmd_id)
1310	tmr->tmr_cmd_ids[cmd_cnt++] = cmd->cmd_id;
1311	}
1312	}
1313
1314	queue_tmr_ring(udev, tmr);
1315
1316	unlock:
1317	mutex_unlock(lock: &udev->cmdr_lock);
1318	}
1319
1320	static bool tcmu_handle_completion(struct tcmu_cmd *cmd,
1321	struct tcmu_cmd_entry *entry, bool keep_buf)
1322	{
1323	struct se_cmd *se_cmd = cmd->se_cmd;
1324	struct tcmu_dev *udev = cmd->tcmu_dev;
1325	bool read_len_valid = false;
1326	bool ret = true;
1327	uint32_t read_len;
1328
1329	/*
1330	* cmd has been completed already from timeout, just reclaim
1331	* data area space and free cmd
1332	*/
1333	if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
1334	WARN_ON_ONCE(se_cmd);
1335	goto out;
1336	}
1337	if (test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags)) {
1338	pr_err("cmd_id %u already completed with KEEP_BUF, ring is broken\n",
1339	entry->hdr.cmd_id);
1340	set_bit(TCMU_DEV_BIT_BROKEN, addr: &udev->flags);
1341	ret = false;
1342	goto out;
1343	}
1344
1345	list_del_init(entry: &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, tcmu_cmd: cmd, bidi: true, read_len);
1374	} else if (se_cmd->data_direction == DMA_FROM_DEVICE) {
1375	gather_data_area(udev, tcmu_cmd: cmd, bidi: false, read_len);
1376	} else if (se_cmd->data_direction == DMA_TO_DEVICE) {
1377	/* TODO: */
1378	} else if (se_cmd->data_direction != DMA_NONE) {
1379	pr_warn("TCMU: data direction was %d!\n",
1380	se_cmd->data_direction);
1381	}
1382
1383	done:
1384	se_cmd->priv = NULL;
1385	if (read_len_valid) {
1386	pr_debug("read_len = %d\n", read_len);
1387	target_complete_cmd_with_length(cmd->se_cmd,
1388	entry->rsp.scsi_status, read_len);
1389	} else
1390	target_complete_cmd(cmd->se_cmd, entry->rsp.scsi_status);
1391
1392	out:
1393	if (!keep_buf) {
1394	tcmu_cmd_free_data(tcmu_cmd: cmd, len: cmd->dbi_cnt);
1395	tcmu_free_cmd(tcmu_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, addr: &cmd->flags);
1406	set_bit(TCMU_CMD_BIT_KEEP_BUF, addr: &cmd->flags);
1407	}
1408	return ret;
1409	}
1410
1411	static int tcmu_run_tmr_queue(struct tcmu_dev *udev)
1412	{
1413	struct tcmu_tmr *tmr, *tmp;
1414	LIST_HEAD(tmrs);
1415
1416	if (list_empty(head: &udev->tmr_queue))
1417	return 1;
1418
1419	pr_debug("running %s's tmr queue\n", udev->name);
1420
1421	list_splice_init(list: &udev->tmr_queue, head: &tmrs);
1422
1423	list_for_each_entry_safe(tmr, tmp, &tmrs, queue_entry) {
1424	list_del_init(entry: &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(list: &tmrs, head: &udev->tmr_queue);
1436	return 0;
1437	}
1438	}
1439
1440	return 1;
1441	}
1442
1443	static bool tcmu_handle_completions(struct tcmu_dev *udev)
1444	{
1445	struct tcmu_mailbox *mb;
1446	struct tcmu_cmd *cmd;
1447	bool free_space = false;
1448
1449	if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
1450	pr_err("ring broken, not handling completions\n");
1451	return false;
1452	}
1453
1454	mb = udev->mb_addr;
1455	tcmu_flush_dcache_range(vaddr: mb, size: 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(head: udev->cmdr_last_cleaned,
1467	size: udev->cmdr_size);
1468	tcmu_flush_dcache_range(vaddr: entry, size: ring_left < sizeof(*entry) ?
1469	ring_left : sizeof(*entry));
1470
1471	free_space = true;
1472
1473	if (tcmu_hdr_get_op(len_op: entry->hdr.len_op) == TCMU_OP_PAD ||
1474	tcmu_hdr_get_op(len_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, index: entry->hdr.cmd_id);
1485	else
1486	cmd = xa_erase(&udev->commands, index: 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, addr: &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(v: &global_page_count) > tcmu_global_max_pages &&
1505	xa_empty(xa: &udev->commands) && list_empty(head: &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(dwork: &tcmu_unmap_work, delay: 0);
1511	}
1512	if (udev->cmd_time_out)
1513	tcmu_set_next_deadline(queue: &udev->inflight_queue, timer: &udev->cmd_timer);
1514
1515	return free_space;
1516	}
1517
1518	static void tcmu_check_expired_ring_cmd(struct tcmu_cmd *cmd)
1519	{
1520	struct se_cmd *se_cmd;
1521
1522	if (!time_after_eq(jiffies, cmd->deadline))
1523	return;
1524
1525	set_bit(TCMU_CMD_BIT_EXPIRED, addr: &cmd->flags);
1526	list_del_init(entry: &cmd->queue_entry);
1527	se_cmd = cmd->se_cmd;
1528	se_cmd->priv = NULL;
1529	cmd->se_cmd = NULL;
1530
1531	pr_debug("Timing out inflight cmd %u on dev %s.\n",
1532	cmd->cmd_id, cmd->tcmu_dev->name);
1533
1534	target_complete_cmd(se_cmd, SAM_STAT_CHECK_CONDITION);
1535	}
1536
1537	static void tcmu_check_expired_queue_cmd(struct tcmu_cmd *cmd)
1538	{
1539	struct se_cmd *se_cmd;
1540
1541	if (!time_after_eq(jiffies, cmd->deadline))
1542	return;
1543
1544	pr_debug("Timing out queued cmd %p on dev %s.\n",
1545	cmd, cmd->tcmu_dev->name);
1546
1547	list_del_init(entry: &cmd->queue_entry);
1548	se_cmd = cmd->se_cmd;
1549	tcmu_free_cmd(tcmu_cmd: cmd);
1550
1551	se_cmd->priv = NULL;
1552	target_complete_cmd(se_cmd, SAM_STAT_TASK_SET_FULL);
1553	}
1554
1555	static void tcmu_device_timedout(struct tcmu_dev *udev)
1556	{
1557	spin_lock(lock: &timed_out_udevs_lock);
1558	if (list_empty(head: &udev->timedout_entry))
1559	list_add_tail(new: &udev->timedout_entry, head: &timed_out_udevs);
1560	spin_unlock(lock: &timed_out_udevs_lock);
1561
1562	schedule_delayed_work(dwork: &tcmu_unmap_work, delay: 0);
1563	}
1564
1565	static void tcmu_cmd_timedout(struct timer_list *t)
1566	{
1567	struct tcmu_dev *udev = timer_container_of(udev, t, cmd_timer);
1568
1569	pr_debug("%s cmd timeout has expired\n", udev->name);
1570	tcmu_device_timedout(udev);
1571	}
1572
1573	static void tcmu_qfull_timedout(struct timer_list *t)
1574	{
1575	struct tcmu_dev *udev = timer_container_of(udev, t, qfull_timer);
1576
1577	pr_debug("%s qfull timeout has expired\n", udev->name);
1578	tcmu_device_timedout(udev);
1579	}
1580
1581	static int tcmu_attach_hba(struct se_hba *hba, u32 host_id)
1582	{
1583	struct tcmu_hba *tcmu_hba;
1584
1585	tcmu_hba = kzalloc(sizeof(struct tcmu_hba), GFP_KERNEL);
1586	if (!tcmu_hba)
1587	return -ENOMEM;
1588
1589	tcmu_hba->host_id = host_id;
1590	hba->hba_ptr = tcmu_hba;
1591
1592	return 0;
1593	}
1594
1595	static void tcmu_detach_hba(struct se_hba *hba)
1596	{
1597	kfree(objp: hba->hba_ptr);
1598	hba->hba_ptr = NULL;
1599	}
1600
1601	static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name)
1602	{
1603	struct tcmu_dev *udev;
1604
1605	udev = kzalloc(sizeof(struct tcmu_dev), GFP_KERNEL);
1606	if (!udev)
1607	return NULL;
1608	kref_init(kref: &udev->kref);
1609
1610	udev->name = kstrdup(s: name, GFP_KERNEL);
1611	if (!udev->name) {
1612	kfree(objp: 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(list: &udev->node);
1628	INIT_LIST_HEAD(list: &udev->timedout_entry);
1629	INIT_LIST_HEAD(list: &udev->qfull_queue);
1630	INIT_LIST_HEAD(list: &udev->tmr_queue);
1631	INIT_LIST_HEAD(list: &udev->inflight_queue);
1632	xa_init_flags(xa: &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(xa: &udev->data_pages);
1638
1639	return &udev->se_dev;
1640	}
1641
1642	static void tcmu_dev_call_rcu(struct rcu_head *p)
1643	{
1644	struct se_device *dev = container_of(p, struct se_device, rcu_head);
1645	struct tcmu_dev *udev = TCMU_DEV(dev);
1646
1647	kfree(objp: udev->uio_info.name);
1648	kfree(objp: udev->name);
1649	kfree(objp: udev);
1650	}
1651
1652	static int tcmu_check_and_free_pending_cmd(struct tcmu_cmd *cmd)
1653	{
1654	if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags) ||
1655	test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags)) {
1656	kmem_cache_free(s: tcmu_cmd_cache, objp: cmd);
1657	return 0;
1658	}
1659	return -EINVAL;
1660	}
1661
1662	static u32 tcmu_blocks_release(struct tcmu_dev *udev, unsigned long first,
1663	unsigned long last)
1664	{
1665	struct page *page;
1666	unsigned long dpi;
1667	u32 pages_freed = 0;
1668
1669	first = first * udev->data_pages_per_blk;
1670	last = (last + 1) * udev->data_pages_per_blk - 1;
1671	xa_for_each_range(&udev->data_pages, dpi, page, first, last) {
1672	xa_erase(&udev->data_pages, index: 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(i: pages_freed, v: &global_page_count);
1698
1699	return pages_freed;
1700	}
1701
1702	static void tcmu_remove_all_queued_tmr(struct tcmu_dev *udev)
1703	{
1704	struct tcmu_tmr *tmr, *tmp;
1705
1706	list_for_each_entry_safe(tmr, tmp, &udev->tmr_queue, queue_entry) {
1707	list_del_init(entry: &tmr->queue_entry);
1708	kfree(objp: tmr);
1709	}
1710	}
1711
1712	static void tcmu_dev_kref_release(struct kref *kref)
1713	{
1714	struct tcmu_dev *udev = container_of(kref, struct tcmu_dev, kref);
1715	struct se_device *dev = &udev->se_dev;
1716	struct tcmu_cmd *cmd;
1717	bool all_expired = true;
1718	unsigned long i;
1719
1720	vfree(addr: udev->mb_addr);
1721	udev->mb_addr = NULL;
1722
1723	spin_lock_bh(lock: &timed_out_udevs_lock);
1724	if (!list_empty(head: &udev->timedout_entry))
1725	list_del(entry: &udev->timedout_entry);
1726	spin_unlock_bh(lock: &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(head: &udev->qfull_queue))
1737	all_expired = false;
1738	xa_destroy(&udev->commands);
1739	WARN_ON(!all_expired);
1740
1741	tcmu_blocks_release(udev, first: 0, last: udev->dbi_max);
1742	bitmap_free(bitmap: udev->data_bitmap);
1743	mutex_unlock(lock: &udev->cmdr_lock);
1744
1745	pr_debug("dev_kref_release\n");
1746
1747	call_rcu(head: &dev->rcu_head, func: tcmu_dev_call_rcu);
1748	}
1749
1750	static void run_qfull_queue(struct tcmu_dev *udev, bool fail)
1751	{
1752	struct tcmu_cmd *tcmu_cmd, *tmp_cmd;
1753	LIST_HEAD(cmds);
1754	sense_reason_t scsi_ret;
1755	int ret;
1756
1757	if (list_empty(head: &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(list: &udev->qfull_queue, head: &cmds);
1763
1764	list_for_each_entry_safe(tcmu_cmd, tmp_cmd, &cmds, queue_entry) {
1765	list_del_init(entry: &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_err: &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(list: &cmds, head: &udev->qfull_queue);
1803	break;
1804	}
1805	}
1806
1807	tcmu_set_next_deadline(queue: &udev->qfull_queue, timer: &udev->qfull_timer);
1808	}
1809
1810	static int tcmu_irqcontrol(struct uio_info *info, s32 irq_on)
1811	{
1812	struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1813
1814	mutex_lock(&udev->cmdr_lock);
1815	if (tcmu_handle_completions(udev))
1816	run_qfull_queue(udev, fail: false);
1817	mutex_unlock(lock: &udev->cmdr_lock);
1818
1819	return 0;
1820	}
1821
1822	/*
1823	* mmap code from uio.c. Copied here because we want to hook mmap()
1824	* and this stuff must come along.
1825	*/
1826	static int tcmu_find_mem_index(struct vm_area_struct *vma)
1827	{
1828	struct tcmu_dev *udev = vma->vm_private_data;
1829	struct uio_info *info = &udev->uio_info;
1830
1831	if (vma->vm_pgoff < MAX_UIO_MAPS) {
1832	if (info->mem[vma->vm_pgoff].size == 0)
1833	return -1;
1834	return (int)vma->vm_pgoff;
1835	}
1836	return -1;
1837	}
1838
1839	static struct page *tcmu_try_get_data_page(struct tcmu_dev *udev, uint32_t dpi)
1840	{
1841	struct page *page;
1842
1843	mutex_lock(&udev->cmdr_lock);
1844	page = xa_load(&udev->data_pages, index: dpi);
1845	if (likely(page)) {
1846	get_page(page);
1847	lock_page(page);
1848	mutex_unlock(lock: &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(lock: &udev->cmdr_lock);
1859
1860	return NULL;
1861	}
1862
1863	static void tcmu_vma_open(struct vm_area_struct *vma)
1864	{
1865	struct tcmu_dev *udev = vma->vm_private_data;
1866
1867	pr_debug("vma_open\n");
1868
1869	kref_get(kref: &udev->kref);
1870	}
1871
1872	static void tcmu_vma_close(struct vm_area_struct *vma)
1873	{
1874	struct tcmu_dev *udev = vma->vm_private_data;
1875
1876	pr_debug("vma_close\n");
1877
1878	/* release ref from tcmu_vma_open */
1879	kref_put(kref: &udev->kref, release: tcmu_dev_kref_release);
1880	}
1881
1882	static vm_fault_t tcmu_vma_fault(struct vm_fault *vmf)
1883	{
1884	struct tcmu_dev *udev = vmf->vma->vm_private_data;
1885	struct uio_info *info = &udev->uio_info;
1886	struct page *page;
1887	unsigned long offset;
1888	void *addr;
1889	vm_fault_t ret = 0;
1890
1891	int mi = tcmu_find_mem_index(vma: vmf->vma);
1892	if (mi < 0)
1893	return VM_FAULT_SIGBUS;
1894
1895	/*
1896	* We need to subtract mi because userspace uses offset = N*PAGE_SIZE
1897	* to use mem[N].
1898	*/
1899	offset = (vmf->pgoff - mi) << PAGE_SHIFT;
1900
1901	if (offset < udev->data_off) {
1902	/* For the vmalloc()ed cmd area pages */
1903	addr = (void *)(unsigned long)info->mem[mi].addr + offset;
1904	page = vmalloc_to_page(addr);
1905	get_page(page);
1906	} else {
1907	uint32_t dpi;
1908
1909	/* For the dynamically growing data area pages */
1910	dpi = (offset - udev->data_off) / PAGE_SIZE;
1911	page = tcmu_try_get_data_page(udev, dpi);
1912	if (!page)
1913	return VM_FAULT_SIGBUS;
1914	ret = VM_FAULT_LOCKED;
1915	}
1916
1917	vmf->page = page;
1918	return ret;
1919	}
1920
1921	static const struct vm_operations_struct tcmu_vm_ops = {
1922	.open = tcmu_vma_open,
1923	.close = tcmu_vma_close,
1924	.fault = tcmu_vma_fault,
1925	};
1926
1927	static int tcmu_mmap(struct uio_info *info, struct vm_area_struct *vma)
1928	{
1929	struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1930
1931	vm_flags_set(vma, VM_DONTEXPAND | VM_DONTDUMP);
1932	vma->vm_ops = &tcmu_vm_ops;
1933
1934	vma->vm_private_data = udev;
1935
1936	/* Ensure the mmap is exactly the right size */
1937	if (vma_pages(vma) != udev->mmap_pages)
1938	return -EINVAL;
1939
1940	tcmu_vma_open(vma);
1941
1942	return 0;
1943	}
1944
1945	static int tcmu_open(struct uio_info *info, struct inode *inode)
1946	{
1947	struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1948
1949	/* O_EXCL not supported for char devs, so fake it? */
1950	if (test_and_set_bit(TCMU_DEV_BIT_OPEN, addr: &udev->flags))
1951	return -EBUSY;
1952
1953	udev->inode = inode;
1954
1955	pr_debug("open\n");
1956
1957	return 0;
1958	}
1959
1960	static int tcmu_release(struct uio_info *info, struct inode *inode)
1961	{
1962	struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1963	struct tcmu_cmd *cmd;
1964	unsigned long i;
1965	bool freed = false;
1966
1967	mutex_lock(&udev->cmdr_lock);
1968
1969	xa_for_each(&udev->commands, i, cmd) {
1970	/* Cmds with KEEP_BUF set are no longer on the ring, but
1971	* userspace still holds the data buffer. If userspace closes
1972	* we implicitly free these cmds and buffers, since after new
1973	* open the (new ?) userspace cannot find the cmd in the ring
1974	* and thus never will release the buffer by writing cmd_id to
1975	* free_kept_buf action attribute.
1976	*/
1977	if (!test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags))
1978	continue;
1979	pr_debug("removing KEEP_BUF cmd %u on dev %s from ring\n",
1980	cmd->cmd_id, udev->name);
1981	freed = true;
1982
1983	xa_erase(&udev->commands, index: i);
1984	tcmu_cmd_free_data(tcmu_cmd: cmd, len: cmd->dbi_cnt);
1985	tcmu_free_cmd(tcmu_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(head: &udev->tmr_queue))
1992	run_qfull_queue(udev, fail: false);
1993
1994	mutex_unlock(lock: &udev->cmdr_lock);
1995
1996	clear_bit(TCMU_DEV_BIT_OPEN, addr: &udev->flags);
1997
1998	pr_debug("close\n");
1999
2000	return 0;
2001	}
2002
2003	static int tcmu_init_genl_cmd_reply(struct tcmu_dev *udev, int cmd)
2004	{
2005	struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
2006
2007	if (!tcmu_kern_cmd_reply_supported)
2008	return 0;
2009
2010	if (udev->nl_reply_supported <= 0)
2011	return 0;
2012
2013	mutex_lock(&tcmu_nl_cmd_mutex);
2014
2015	if (tcmu_netlink_blocked) {
2016	mutex_unlock(lock: &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(lock: &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(x: &nl_cmd->complete);
2033	INIT_LIST_HEAD(list: &nl_cmd->nl_list);
2034
2035	list_add_tail(new: &nl_cmd->nl_list, head: &tcmu_nl_cmd_list);
2036
2037	mutex_unlock(lock: &tcmu_nl_cmd_mutex);
2038	return 0;
2039	}
2040
2041	static void tcmu_destroy_genl_cmd_reply(struct tcmu_dev *udev)
2042	{
2043	struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
2044
2045	if (!tcmu_kern_cmd_reply_supported)
2046	return;
2047
2048	if (udev->nl_reply_supported <= 0)
2049	return;
2050
2051	mutex_lock(&tcmu_nl_cmd_mutex);
2052
2053	list_del(entry: &nl_cmd->nl_list);
2054	memset(nl_cmd, 0, sizeof(*nl_cmd));
2055
2056	mutex_unlock(lock: &tcmu_nl_cmd_mutex);
2057	}
2058
2059	static int tcmu_wait_genl_cmd_reply(struct tcmu_dev *udev)
2060	{
2061	struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
2062	int ret;
2063
2064	if (!tcmu_kern_cmd_reply_supported)
2065	return 0;
2066
2067	if (udev->nl_reply_supported <= 0)
2068	return 0;
2069
2070	pr_debug("sleeping for nl reply\n");
2071	wait_for_completion(&nl_cmd->complete);
2072
2073	mutex_lock(&tcmu_nl_cmd_mutex);
2074	nl_cmd->cmd = TCMU_CMD_UNSPEC;
2075	ret = nl_cmd->status;
2076	mutex_unlock(lock: &tcmu_nl_cmd_mutex);
2077
2078	return ret;
2079	}
2080
2081	static int tcmu_netlink_event_init(struct tcmu_dev *udev,
2082	enum tcmu_genl_cmd cmd,
2083	struct sk_buff **buf, void **hdr)
2084	{
2085	struct sk_buff *skb;
2086	void *msg_header;
2087	int ret = -ENOMEM;
2088
2089	skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2090	if (!skb)
2091	return ret;
2092
2093	msg_header = genlmsg_put(skb, portid: 0, seq: 0, family: &tcmu_genl_family, flags: 0, cmd);
2094	if (!msg_header)
2095	goto free_skb;
2096
2097	ret = nla_put_string(skb, attrtype: TCMU_ATTR_DEVICE, str: udev->uio_info.name);
2098	if (ret < 0)
2099	goto free_skb;
2100
2101	ret = nla_put_u32(skb, attrtype: TCMU_ATTR_MINOR, value: udev->uio_info.uio_dev->minor);
2102	if (ret < 0)
2103	goto free_skb;
2104
2105	ret = nla_put_u32(skb, attrtype: TCMU_ATTR_DEVICE_ID, value: udev->se_dev.dev_index);
2106	if (ret < 0)
2107	goto free_skb;
2108
2109	*buf = skb;
2110	*hdr = msg_header;
2111	return ret;
2112
2113	free_skb:
2114	nlmsg_free(skb);
2115	return ret;
2116	}
2117
2118	static int tcmu_netlink_event_send(struct tcmu_dev *udev,
2119	enum tcmu_genl_cmd cmd,
2120	struct sk_buff *skb, void *msg_header)
2121	{
2122	int ret;
2123
2124	genlmsg_end(skb, hdr: 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(family: &tcmu_genl_family, skb, portid: 0,
2133	group: 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
2145	static int tcmu_send_dev_add_event(struct tcmu_dev *udev)
2146	{
2147	struct sk_buff *skb = NULL;
2148	void *msg_header = NULL;
2149	int ret = 0;
2150
2151	ret = tcmu_netlink_event_init(udev, cmd: TCMU_CMD_ADDED_DEVICE, buf: &skb,
2152	hdr: &msg_header);
2153	if (ret < 0)
2154	return ret;
2155	return tcmu_netlink_event_send(udev, cmd: TCMU_CMD_ADDED_DEVICE, skb,
2156	msg_header);
2157	}
2158
2159	static int tcmu_send_dev_remove_event(struct tcmu_dev *udev)
2160	{
2161	struct sk_buff *skb = NULL;
2162	void *msg_header = NULL;
2163	int ret = 0;
2164
2165	ret = tcmu_netlink_event_init(udev, cmd: TCMU_CMD_REMOVED_DEVICE,
2166	buf: &skb, hdr: &msg_header);
2167	if (ret < 0)
2168	return ret;
2169	return tcmu_netlink_event_send(udev, cmd: TCMU_CMD_REMOVED_DEVICE,
2170	skb, msg_header);
2171	}
2172
2173	static int tcmu_update_uio_info(struct tcmu_dev *udev)
2174	{
2175	struct tcmu_hba *hba = udev->hba->hba_ptr;
2176	struct uio_info *info;
2177	char *str;
2178
2179	info = &udev->uio_info;
2180
2181	if (udev->dev_config[0])
2182	str = kasprintf(GFP_KERNEL, fmt: "tcm-user/%u/%s/%s", hba->host_id,
2183	udev->name, udev->dev_config);
2184	else
2185	str = kasprintf(GFP_KERNEL, fmt: "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(objp: info->name);
2192	info->name = str;
2193
2194	return 0;
2195	}
2196
2197	static int tcmu_configure_device(struct se_device *dev)
2198	{
2199	struct tcmu_dev *udev = TCMU_DEV(dev);
2200	struct uio_info *info;
2201	struct tcmu_mailbox *mb;
2202	size_t data_size;
2203	int ret = 0;
2204
2205	ret = tcmu_update_uio_info(udev);
2206	if (ret)
2207	return ret;
2208
2209	info = &udev->uio_info;
2210
2211	mutex_lock(&udev->cmdr_lock);
2212	udev->data_bitmap = bitmap_zalloc(nbits: udev->max_blocks, GFP_KERNEL);
2213	mutex_unlock(lock: &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(kref: &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(new: &udev->node, head: &root_udev);
2292	mutex_unlock(lock: &root_udev_mutex);
2293
2294	return 0;
2295
2296	err_netlink:
2297	kref_put(kref: &udev->kref, release: tcmu_dev_kref_release);
2298	uio_unregister_device(info: &udev->uio_info);
2299	err_register:
2300	vfree(addr: udev->mb_addr);
2301	udev->mb_addr = NULL;
2302	err_vzalloc:
2303	bitmap_free(bitmap: udev->data_bitmap);
2304	udev->data_bitmap = NULL;
2305	err_bitmap_alloc:
2306	kfree(objp: info->name);
2307	info->name = NULL;
2308
2309	return ret;
2310	}
2311
2312	static void tcmu_free_device(struct se_device *dev)
2313	{
2314	struct tcmu_dev *udev = TCMU_DEV(dev);
2315
2316	/* release ref from init */
2317	kref_put(kref: &udev->kref, release: tcmu_dev_kref_release);
2318	}
2319
2320	static void tcmu_destroy_device(struct se_device *dev)
2321	{
2322	struct tcmu_dev *udev = TCMU_DEV(dev);
2323
2324	timer_delete_sync(timer: &udev->cmd_timer);
2325	timer_delete_sync(timer: &udev->qfull_timer);
2326
2327	mutex_lock(&root_udev_mutex);
2328	list_del(entry: &udev->node);
2329	mutex_unlock(lock: &root_udev_mutex);
2330
2331	tcmu_send_dev_remove_event(udev);
2332
2333	uio_unregister_device(info: &udev->uio_info);
2334
2335	/* release ref from configure */
2336	kref_put(kref: &udev->kref, release: tcmu_dev_kref_release);
2337	}
2338
2339	static void tcmu_unblock_dev(struct tcmu_dev *udev)
2340	{
2341	mutex_lock(&udev->cmdr_lock);
2342	clear_bit(TCMU_DEV_BIT_BLOCKED, addr: &udev->flags);
2343	mutex_unlock(lock: &udev->cmdr_lock);
2344	}
2345
2346	static void tcmu_block_dev(struct tcmu_dev *udev)
2347	{
2348	mutex_lock(&udev->cmdr_lock);
2349
2350	if (test_and_set_bit(TCMU_DEV_BIT_BLOCKED, addr: &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, fail: true);
2357
2358	unlock:
2359	mutex_unlock(lock: &udev->cmdr_lock);
2360	}
2361
2362	static void tcmu_reset_ring(struct tcmu_dev *udev, u8 err_level)
2363	{
2364	struct tcmu_mailbox *mb;
2365	struct tcmu_cmd *cmd;
2366	unsigned long i;
2367
2368	mutex_lock(&udev->cmdr_lock);
2369
2370	xa_for_each(&udev->commands, i, cmd) {
2371	pr_debug("removing cmd %u on dev %s from ring %s\n",
2372	cmd->cmd_id, udev->name,
2373	test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags) ?
2374	"(is expired)" :
2375	(test_bit(TCMU_CMD_BIT_KEEP_BUF, &cmd->flags) ?
2376	"(is keep buffer)" : ""));
2377
2378	xa_erase(&udev->commands, index: 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(entry: &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(tcmu_cmd: cmd, len: cmd->dbi_cnt);
2397	tcmu_free_cmd(tcmu_cmd: cmd);
2398	}
2399
2400	mb = udev->mb_addr;
2401	tcmu_flush_dcache_range(vaddr: mb, size: 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(vaddr: mb, size: sizeof(*mb));
2409	clear_bit(TCMU_DEV_BIT_BROKEN, addr: &udev->flags);
2410
2411	timer_delete(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, fail: false);
2423
2424	mutex_unlock(lock: &udev->cmdr_lock);
2425	}
2426
2427	enum {
2428	Opt_dev_config, Opt_dev_size, Opt_hw_block_size, Opt_hw_max_sectors,
2429	Opt_nl_reply_supported, Opt_max_data_area_mb, Opt_data_pages_per_blk,
2430	Opt_cmd_ring_size_mb, Opt_err,
2431	};
2432
2433	static 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
2445	static int tcmu_set_dev_attrib(substring_t *arg, u32 *dev_attrib)
2446	{
2447	int val, ret;
2448
2449	ret = match_int(arg, result: &val);
2450	if (ret < 0) {
2451	pr_err("match_int() failed for dev attrib. Error %d.\n",
2452	ret);
2453	return ret;
2454	}
2455
2456	if (val <= 0) {
2457	pr_err("Invalid dev attrib value %d. Must be greater than zero.\n",
2458	val);
2459	return -EINVAL;
2460	}
2461	*dev_attrib = val;
2462	return 0;
2463	}
2464
2465	static int tcmu_set_max_blocks_param(struct tcmu_dev *udev, substring_t *arg)
2466	{
2467	int val, ret;
2468	uint32_t pages_per_blk = udev->data_pages_per_blk;
2469
2470	ret = match_int(arg, result: &val);
2471	if (ret < 0) {
2472	pr_err("match_int() failed for max_data_area_mb=. Error %d.\n",
2473	ret);
2474	return ret;
2475	}
2476	if (val <= 0) {
2477	pr_err("Invalid max_data_area %d.\n", val);
2478	return -EINVAL;
2479	}
2480	if (val > TCMU_PAGES_TO_MBS(tcmu_global_max_pages)) {
2481	pr_err("%d is too large. Adjusting max_data_area_mb to global limit of %u\n",
2482	val, TCMU_PAGES_TO_MBS(tcmu_global_max_pages));
2483	val = TCMU_PAGES_TO_MBS(tcmu_global_max_pages);
2484	}
2485	if (TCMU_MBS_TO_PAGES(val) < pages_per_blk) {
2486	pr_err("Invalid max_data_area %d (%zu pages): smaller than data_pages_per_blk (%u pages).\n",
2487	val, TCMU_MBS_TO_PAGES(val), pages_per_blk);
2488	return -EINVAL;
2489	}
2490
2491	mutex_lock(&udev->cmdr_lock);
2492	if (udev->data_bitmap) {
2493	pr_err("Cannot set max_data_area_mb after it has been enabled.\n");
2494	ret = -EINVAL;
2495	goto unlock;
2496	}
2497
2498	udev->data_area_mb = val;
2499	udev->max_blocks = TCMU_MBS_TO_PAGES(val) / pages_per_blk;
2500
2501	unlock:
2502	mutex_unlock(lock: &udev->cmdr_lock);
2503	return ret;
2504	}
2505
2506	static int tcmu_set_data_pages_per_blk(struct tcmu_dev *udev, substring_t *arg)
2507	{
2508	int val, ret;
2509
2510	ret = match_int(arg, result: &val);
2511	if (ret < 0) {
2512	pr_err("match_int() failed for data_pages_per_blk=. Error %d.\n",
2513	ret);
2514	return ret;
2515	}
2516
2517	if (val > TCMU_MBS_TO_PAGES(udev->data_area_mb)) {
2518	pr_err("Invalid data_pages_per_blk %d: greater than max_data_area_mb %d -> %zd pages).\n",
2519	val, udev->data_area_mb,
2520	TCMU_MBS_TO_PAGES(udev->data_area_mb));
2521	return -EINVAL;
2522	}
2523
2524	mutex_lock(&udev->cmdr_lock);
2525	if (udev->data_bitmap) {
2526	pr_err("Cannot set data_pages_per_blk after it has been enabled.\n");
2527	ret = -EINVAL;
2528	goto unlock;
2529	}
2530
2531	udev->data_pages_per_blk = val;
2532	udev->max_blocks = TCMU_MBS_TO_PAGES(udev->data_area_mb) / val;
2533
2534	unlock:
2535	mutex_unlock(lock: &udev->cmdr_lock);
2536	return ret;
2537	}
2538
2539	static int tcmu_set_cmd_ring_size(struct tcmu_dev *udev, substring_t *arg)
2540	{
2541	int val, ret;
2542
2543	ret = match_int(arg, result: &val);
2544	if (ret < 0) {
2545	pr_err("match_int() failed for cmd_ring_size_mb=. Error %d.\n",
2546	ret);
2547	return ret;
2548	}
2549
2550	if (val <= 0) {
2551	pr_err("Invalid cmd_ring_size_mb %d.\n", val);
2552	return -EINVAL;
2553	}
2554
2555	mutex_lock(&udev->cmdr_lock);
2556	if (udev->data_bitmap) {
2557	pr_err("Cannot set cmd_ring_size_mb after it has been enabled.\n");
2558	ret = -EINVAL;
2559	goto unlock;
2560	}
2561
2562	udev->cmdr_size = (val << 20) - CMDR_OFF;
2563	if (val > (MB_CMDR_SIZE_DEF >> 20)) {
2564	pr_err("%d is too large. Adjusting cmd_ring_size_mb to global limit of %u\n",
2565	val, (MB_CMDR_SIZE_DEF >> 20));
2566	udev->cmdr_size = CMDR_SIZE_DEF;
2567	}
2568
2569	unlock:
2570	mutex_unlock(lock: &udev->cmdr_lock);
2571	return ret;
2572	}
2573
2574	static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev,
2575	const char *page, ssize_t count)
2576	{
2577	struct tcmu_dev *udev = TCMU_DEV(dev);
2578	char *orig, *ptr, *opts;
2579	substring_t args[MAX_OPT_ARGS];
2580	int ret = 0, token;
2581
2582	opts = kstrdup(s: 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, table: 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], result: &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(arg: &args[0],
2610	dev_attrib: &(dev->dev_attrib.hw_block_size));
2611	break;
2612	case Opt_hw_max_sectors:
2613	ret = tcmu_set_dev_attrib(arg: &args[0],
2614	dev_attrib: &(dev->dev_attrib.hw_max_sectors));
2615	break;
2616	case Opt_nl_reply_supported:
2617	ret = match_int(&args[0], result: &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, arg: &args[0]);
2624	break;
2625	case Opt_data_pages_per_blk:
2626	ret = tcmu_set_data_pages_per_blk(udev, arg: &args[0]);
2627	break;
2628	case Opt_cmd_ring_size_mb:
2629	ret = tcmu_set_cmd_ring_size(udev, arg: &args[0]);
2630	break;
2631	default:
2632	break;
2633	}
2634
2635	if (ret)
2636	break;
2637	}
2638
2639	kfree(objp: orig);
2640	return (!ret) ? count : ret;
2641	}
2642
2643	static ssize_t tcmu_show_configfs_dev_params(struct se_device *dev, char *b)
2644	{
2645	struct tcmu_dev *udev = TCMU_DEV(dev);
2646	ssize_t bl = 0;
2647
2648	bl = sprintf(buf: b + bl, fmt: "Config: %s ",
2649	udev->dev_config[0] ? udev->dev_config : "NULL");
2650	bl += sprintf(buf: b + bl, fmt: "Size: %llu ", udev->dev_size);
2651	bl += sprintf(buf: b + bl, fmt: "MaxDataAreaMB: %u ", udev->data_area_mb);
2652	bl += sprintf(buf: b + bl, fmt: "DataPagesPerBlk: %u ", udev->data_pages_per_blk);
2653	bl += sprintf(buf: b + bl, fmt: "CmdRingSizeMB: %u\n",
2654	(udev->cmdr_size + CMDR_OFF) >> 20);
2655
2656	return bl;
2657	}
2658
2659	static sector_t tcmu_get_blocks(struct se_device *dev)
2660	{
2661	struct tcmu_dev *udev = TCMU_DEV(dev);
2662
2663	return div_u64(dividend: udev->dev_size - dev->dev_attrib.block_size,
2664	divisor: dev->dev_attrib.block_size);
2665	}
2666
2667	static sense_reason_t
2668	tcmu_parse_cdb(struct se_cmd *cmd)
2669	{
2670	return passthrough_parse_cdb(cmd, exec_cmd: tcmu_queue_cmd);
2671	}
2672
2673	static ssize_t tcmu_cmd_time_out_show(struct config_item *item, char *page)
2674	{
2675	struct se_dev_attrib *da = container_of(to_config_group(item),
2676	struct se_dev_attrib, da_group);
2677	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2678
2679	return snprintf(buf: page, PAGE_SIZE, fmt: "%lu\n", udev->cmd_time_out / MSEC_PER_SEC);
2680	}
2681
2682	static ssize_t tcmu_cmd_time_out_store(struct config_item *item, const char *page,
2683	size_t count)
2684	{
2685	struct se_dev_attrib *da = container_of(to_config_group(item),
2686	struct se_dev_attrib, da_group);
2687	struct tcmu_dev *udev = container_of(da->da_dev,
2688	struct tcmu_dev, se_dev);
2689	u32 val;
2690	int ret;
2691
2692	if (da->da_dev->export_count) {
2693	pr_err("Unable to set tcmu cmd_time_out while exports exist\n");
2694	return -EINVAL;
2695	}
2696
2697	ret = kstrtou32(s: page, base: 0, res: &val);
2698	if (ret < 0)
2699	return ret;
2700
2701	udev->cmd_time_out = val * MSEC_PER_SEC;
2702	return count;
2703	}
2704	CONFIGFS_ATTR(tcmu_, cmd_time_out);
2705
2706	static ssize_t tcmu_qfull_time_out_show(struct config_item *item, char *page)
2707	{
2708	struct se_dev_attrib *da = container_of(to_config_group(item),
2709	struct se_dev_attrib, da_group);
2710	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2711
2712	return snprintf(buf: page, PAGE_SIZE, fmt: "%ld\n", udev->qfull_time_out <= 0 ?
2713	udev->qfull_time_out :
2714	udev->qfull_time_out / MSEC_PER_SEC);
2715	}
2716
2717	static ssize_t tcmu_qfull_time_out_store(struct config_item *item,
2718	const char *page, size_t count)
2719	{
2720	struct se_dev_attrib *da = container_of(to_config_group(item),
2721	struct se_dev_attrib, da_group);
2722	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2723	s32 val;
2724	int ret;
2725
2726	ret = kstrtos32(s: page, base: 0, res: &val);
2727	if (ret < 0)
2728	return ret;
2729
2730	if (val >= 0) {
2731	udev->qfull_time_out = val * MSEC_PER_SEC;
2732	} else if (val == -1) {
2733	udev->qfull_time_out = val;
2734	} else {
2735	printk(KERN_ERR "Invalid qfull timeout value %d\n", val);
2736	return -EINVAL;
2737	}
2738	return count;
2739	}
2740	CONFIGFS_ATTR(tcmu_, qfull_time_out);
2741
2742	static ssize_t tcmu_max_data_area_mb_show(struct config_item *item, char *page)
2743	{
2744	struct se_dev_attrib *da = container_of(to_config_group(item),
2745	struct se_dev_attrib, da_group);
2746	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2747
2748	return snprintf(buf: page, PAGE_SIZE, fmt: "%u\n", udev->data_area_mb);
2749	}
2750	CONFIGFS_ATTR_RO(tcmu_, max_data_area_mb);
2751
2752	static ssize_t tcmu_data_pages_per_blk_show(struct config_item *item,
2753	char *page)
2754	{
2755	struct se_dev_attrib *da = container_of(to_config_group(item),
2756	struct se_dev_attrib, da_group);
2757	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2758
2759	return snprintf(buf: page, PAGE_SIZE, fmt: "%u\n", udev->data_pages_per_blk);
2760	}
2761	CONFIGFS_ATTR_RO(tcmu_, data_pages_per_blk);
2762
2763	static ssize_t tcmu_cmd_ring_size_mb_show(struct config_item *item, char *page)
2764	{
2765	struct se_dev_attrib *da = container_of(to_config_group(item),
2766	struct se_dev_attrib, da_group);
2767	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2768
2769	return snprintf(buf: page, PAGE_SIZE, fmt: "%u\n",
2770	(udev->cmdr_size + CMDR_OFF) >> 20);
2771	}
2772	CONFIGFS_ATTR_RO(tcmu_, cmd_ring_size_mb);
2773
2774	static ssize_t tcmu_dev_config_show(struct config_item *item, char *page)
2775	{
2776	struct se_dev_attrib *da = container_of(to_config_group(item),
2777	struct se_dev_attrib, da_group);
2778	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2779
2780	return snprintf(buf: page, PAGE_SIZE, fmt: "%s\n", udev->dev_config);
2781	}
2782
2783	static int tcmu_send_dev_config_event(struct tcmu_dev *udev,
2784	const char *reconfig_data)
2785	{
2786	struct sk_buff *skb = NULL;
2787	void *msg_header = NULL;
2788	int ret = 0;
2789
2790	ret = tcmu_netlink_event_init(udev, cmd: TCMU_CMD_RECONFIG_DEVICE,
2791	buf: &skb, hdr: &msg_header);
2792	if (ret < 0)
2793	return ret;
2794	ret = nla_put_string(skb, attrtype: TCMU_ATTR_DEV_CFG, str: reconfig_data);
2795	if (ret < 0) {
2796	nlmsg_free(skb);
2797	return ret;
2798	}
2799	return tcmu_netlink_event_send(udev, cmd: TCMU_CMD_RECONFIG_DEVICE,
2800	skb, msg_header);
2801	}
2802
2803
2804	static ssize_t tcmu_dev_config_store(struct config_item *item, const char *page,
2805	size_t count)
2806	{
2807	struct se_dev_attrib *da = container_of(to_config_group(item),
2808	struct se_dev_attrib, da_group);
2809	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2810	int ret, len;
2811
2812	len = strlen(page);
2813	if (!len || len > TCMU_CONFIG_LEN - 1)
2814	return -EINVAL;
2815
2816	/* Check if device has been configured before */
2817	if (target_dev_configured(se_dev: &udev->se_dev)) {
2818	ret = tcmu_send_dev_config_event(udev, reconfig_data: page);
2819	if (ret) {
2820	pr_err("Unable to reconfigure device\n");
2821	return ret;
2822	}
2823	strscpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2824
2825	ret = tcmu_update_uio_info(udev);
2826	if (ret)
2827	return ret;
2828	return count;
2829	}
2830	strscpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2831
2832	return count;
2833	}
2834	CONFIGFS_ATTR(tcmu_, dev_config);
2835
2836	static ssize_t tcmu_dev_size_show(struct config_item *item, char *page)
2837	{
2838	struct se_dev_attrib *da = container_of(to_config_group(item),
2839	struct se_dev_attrib, da_group);
2840	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2841
2842	return snprintf(buf: page, PAGE_SIZE, fmt: "%llu\n", udev->dev_size);
2843	}
2844
2845	static int tcmu_send_dev_size_event(struct tcmu_dev *udev, u64 size)
2846	{
2847	struct sk_buff *skb = NULL;
2848	void *msg_header = NULL;
2849	int ret = 0;
2850
2851	ret = tcmu_netlink_event_init(udev, cmd: TCMU_CMD_RECONFIG_DEVICE,
2852	buf: &skb, hdr: &msg_header);
2853	if (ret < 0)
2854	return ret;
2855	ret = nla_put_u64_64bit(skb, attrtype: TCMU_ATTR_DEV_SIZE,
2856	value: size, padattr: TCMU_ATTR_PAD);
2857	if (ret < 0) {
2858	nlmsg_free(skb);
2859	return ret;
2860	}
2861	return tcmu_netlink_event_send(udev, cmd: TCMU_CMD_RECONFIG_DEVICE,
2862	skb, msg_header);
2863	}
2864
2865	static ssize_t tcmu_dev_size_store(struct config_item *item, const char *page,
2866	size_t count)
2867	{
2868	struct se_dev_attrib *da = container_of(to_config_group(item),
2869	struct se_dev_attrib, da_group);
2870	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2871	u64 val;
2872	int ret;
2873
2874	ret = kstrtou64(s: page, base: 0, res: &val);
2875	if (ret < 0)
2876	return ret;
2877
2878	/* Check if device has been configured before */
2879	if (target_dev_configured(se_dev: &udev->se_dev)) {
2880	ret = tcmu_send_dev_size_event(udev, size: val);
2881	if (ret) {
2882	pr_err("Unable to reconfigure device\n");
2883	return ret;
2884	}
2885	}
2886	udev->dev_size = val;
2887	return count;
2888	}
2889	CONFIGFS_ATTR(tcmu_, dev_size);
2890
2891	static ssize_t tcmu_nl_reply_supported_show(struct config_item *item,
2892	char *page)
2893	{
2894	struct se_dev_attrib *da = container_of(to_config_group(item),
2895	struct se_dev_attrib, da_group);
2896	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2897
2898	return snprintf(buf: page, PAGE_SIZE, fmt: "%d\n", udev->nl_reply_supported);
2899	}
2900
2901	static ssize_t tcmu_nl_reply_supported_store(struct config_item *item,
2902	const char *page, size_t count)
2903	{
2904	struct se_dev_attrib *da = container_of(to_config_group(item),
2905	struct se_dev_attrib, da_group);
2906	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2907	s8 val;
2908	int ret;
2909
2910	ret = kstrtos8(s: page, base: 0, res: &val);
2911	if (ret < 0)
2912	return ret;
2913
2914	udev->nl_reply_supported = val;
2915	return count;
2916	}
2917	CONFIGFS_ATTR(tcmu_, nl_reply_supported);
2918
2919	static ssize_t tcmu_emulate_write_cache_show(struct config_item *item,
2920	char *page)
2921	{
2922	struct se_dev_attrib *da = container_of(to_config_group(item),
2923	struct se_dev_attrib, da_group);
2924
2925	return snprintf(buf: page, PAGE_SIZE, fmt: "%i\n", da->emulate_write_cache);
2926	}
2927
2928	static int tcmu_send_emulate_write_cache(struct tcmu_dev *udev, u8 val)
2929	{
2930	struct sk_buff *skb = NULL;
2931	void *msg_header = NULL;
2932	int ret = 0;
2933
2934	ret = tcmu_netlink_event_init(udev, cmd: TCMU_CMD_RECONFIG_DEVICE,
2935	buf: &skb, hdr: &msg_header);
2936	if (ret < 0)
2937	return ret;
2938	ret = nla_put_u8(skb, attrtype: TCMU_ATTR_WRITECACHE, value: val);
2939	if (ret < 0) {
2940	nlmsg_free(skb);
2941	return ret;
2942	}
2943	return tcmu_netlink_event_send(udev, cmd: TCMU_CMD_RECONFIG_DEVICE,
2944	skb, msg_header);
2945	}
2946
2947	static ssize_t tcmu_emulate_write_cache_store(struct config_item *item,
2948	const char *page, size_t count)
2949	{
2950	struct se_dev_attrib *da = container_of(to_config_group(item),
2951	struct se_dev_attrib, da_group);
2952	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2953	u8 val;
2954	int ret;
2955
2956	ret = kstrtou8(s: page, base: 0, res: &val);
2957	if (ret < 0)
2958	return ret;
2959
2960	/* Check if device has been configured before */
2961	if (target_dev_configured(se_dev: &udev->se_dev)) {
2962	ret = tcmu_send_emulate_write_cache(udev, val);
2963	if (ret) {
2964	pr_err("Unable to reconfigure device\n");
2965	return ret;
2966	}
2967	}
2968
2969	da->emulate_write_cache = val;
2970	return count;
2971	}
2972	CONFIGFS_ATTR(tcmu_, emulate_write_cache);
2973
2974	static ssize_t tcmu_tmr_notification_show(struct config_item *item, char *page)
2975	{
2976	struct se_dev_attrib *da = container_of(to_config_group(item),
2977	struct se_dev_attrib, da_group);
2978	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2979
2980	return snprintf(buf: page, PAGE_SIZE, fmt: "%i\n",
2981	test_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags));
2982	}
2983
2984	static ssize_t tcmu_tmr_notification_store(struct config_item *item,
2985	const char *page, size_t count)
2986	{
2987	struct se_dev_attrib *da = container_of(to_config_group(item),
2988	struct se_dev_attrib, da_group);
2989	struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2990	u8 val;
2991	int ret;
2992
2993	ret = kstrtou8(s: page, base: 0, res: &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, addr: &udev->flags);
3001	else
3002	clear_bit(TCMU_DEV_BIT_TMR_NOTIFY, addr: &udev->flags);
3003	return count;
3004	}
3005	CONFIGFS_ATTR(tcmu_, tmr_notification);
3006
3007	static ssize_t tcmu_block_dev_show(struct config_item *item, char *page)
3008	{
3009	struct se_device *se_dev = container_of(to_config_group(item),
3010	struct se_device,
3011	dev_action_group);
3012	struct tcmu_dev *udev = TCMU_DEV(se_dev);
3013
3014	if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
3015	return snprintf(buf: page, PAGE_SIZE, fmt: "%s\n", "blocked");
3016	else
3017	return snprintf(buf: page, PAGE_SIZE, fmt: "%s\n", "unblocked");
3018	}
3019
3020	static ssize_t tcmu_block_dev_store(struct config_item *item, const char *page,
3021	size_t count)
3022	{
3023	struct se_device *se_dev = container_of(to_config_group(item),
3024	struct se_device,
3025	dev_action_group);
3026	struct tcmu_dev *udev = TCMU_DEV(se_dev);
3027	u8 val;
3028	int ret;
3029
3030	if (!target_dev_configured(se_dev: &udev->se_dev)) {
3031	pr_err("Device is not configured.\n");
3032	return -EINVAL;
3033	}
3034
3035	ret = kstrtou8(s: page, base: 0, res: &val);
3036	if (ret < 0)
3037	return ret;
3038
3039	if (val > 1) {
3040	pr_err("Invalid block value %d\n", val);
3041	return -EINVAL;
3042	}
3043
3044	if (!val)
3045	tcmu_unblock_dev(udev);
3046	else
3047	tcmu_block_dev(udev);
3048	return count;
3049	}
3050	CONFIGFS_ATTR(tcmu_, block_dev);
3051
3052	static ssize_t tcmu_reset_ring_store(struct config_item *item, const char *page,
3053	size_t count)
3054	{
3055	struct se_device *se_dev = container_of(to_config_group(item),
3056	struct se_device,
3057	dev_action_group);
3058	struct tcmu_dev *udev = TCMU_DEV(se_dev);
3059	u8 val;
3060	int ret;
3061
3062	if (!target_dev_configured(se_dev: &udev->se_dev)) {
3063	pr_err("Device is not configured.\n");
3064	return -EINVAL;
3065	}
3066
3067	ret = kstrtou8(s: page, base: 0, res: &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, err_level: val);
3077	return count;
3078	}
3079	CONFIGFS_ATTR_WO(tcmu_, reset_ring);
3080
3081	static ssize_t tcmu_free_kept_buf_store(struct config_item *item, const char *page,
3082	size_t count)
3083	{
3084	struct se_device *se_dev = container_of(to_config_group(item),
3085	struct se_device,
3086	dev_action_group);
3087	struct tcmu_dev *udev = TCMU_DEV(se_dev);
3088	struct tcmu_cmd *cmd;
3089	u16 cmd_id;
3090	int ret;
3091
3092	if (!target_dev_configured(se_dev: &udev->se_dev)) {
3093	pr_err("Device is not configured.\n");
3094	return -EINVAL;
3095	}
3096
3097	ret = kstrtou16(s: page, base: 0, res: &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(tcmu_cmd: cmd, len: cmd->dbi_cnt);
3126	tcmu_free_cmd(tcmu_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(head: &udev->tmr_queue))
3132	run_qfull_queue(udev, fail: false);
3133
3134	out_unlock:
3135	mutex_unlock(lock: &udev->cmdr_lock);
3136	return count;
3137	}
3138	CONFIGFS_ATTR_WO(tcmu_, free_kept_buf);
3139
3140	static struct configfs_attribute *tcmu_attrib_attrs[] = {
3141	&tcmu_attr_cmd_time_out,
3142	&tcmu_attr_qfull_time_out,
3143	&tcmu_attr_max_data_area_mb,
3144	&tcmu_attr_data_pages_per_blk,
3145	&tcmu_attr_cmd_ring_size_mb,
3146	&tcmu_attr_dev_config,
3147	&tcmu_attr_dev_size,
3148	&tcmu_attr_emulate_write_cache,
3149	&tcmu_attr_tmr_notification,
3150	&tcmu_attr_nl_reply_supported,
3151	NULL,
3152	};
3153
3154	static struct configfs_attribute **tcmu_attrs;
3155
3156	static struct configfs_attribute *tcmu_action_attrs[] = {
3157	&tcmu_attr_block_dev,
3158	&tcmu_attr_reset_ring,
3159	&tcmu_attr_free_kept_buf,
3160	NULL,
3161	};
3162
3163	static struct target_backend_ops tcmu_ops = {
3164	.name = "user",
3165	.owner = THIS_MODULE,
3166	.transport_flags_default = TRANSPORT_FLAG_PASSTHROUGH,
3167	.transport_flags_changeable = TRANSPORT_FLAG_PASSTHROUGH_PGR |
3168	TRANSPORT_FLAG_PASSTHROUGH_ALUA,
3169	.attach_hba = tcmu_attach_hba,
3170	.detach_hba = tcmu_detach_hba,
3171	.alloc_device = tcmu_alloc_device,
3172	.configure_device = tcmu_configure_device,
3173	.destroy_device = tcmu_destroy_device,
3174	.free_device = tcmu_free_device,
3175	.unplug_device = tcmu_unplug_device,
3176	.plug_device = tcmu_plug_device,
3177	.parse_cdb = tcmu_parse_cdb,
3178	.tmr_notify = tcmu_tmr_notify,
3179	.set_configfs_dev_params = tcmu_set_configfs_dev_params,
3180	.show_configfs_dev_params = tcmu_show_configfs_dev_params,
3181	.get_device_type = sbc_get_device_type,
3182	.get_blocks = tcmu_get_blocks,
3183	.tb_dev_action_attrs = tcmu_action_attrs,
3184	};
3185
3186	static void find_free_blocks(void)
3187	{
3188	struct tcmu_dev *udev;
3189	loff_t off;
3190	u32 pages_freed, total_pages_freed = 0;
3191	u32 start, end, block, total_blocks_freed = 0;
3192
3193	if (atomic_read(v: &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(se_dev: &udev->se_dev)) {
3201	mutex_unlock(lock: &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, fail: false);
3208
3209	/* Skip the udevs in idle */
3210	if (!udev->dbi_thresh) {
3211	mutex_unlock(lock: &udev->cmdr_lock);
3212	continue;
3213	}
3214
3215	end = udev->dbi_max + 1;
3216	block = find_last_bit(addr: udev->data_bitmap, size: 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(lock: &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, first: start, last: 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(mapping: udev->inode->i_mapping, holebegin: off, holelen: 0, even_cows: 1);
3248
3249	mutex_unlock(lock: &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(lock: &root_udev_mutex);
3258
3259	if (atomic_read(v: &global_page_count) > tcmu_global_max_pages)
3260	schedule_delayed_work(dwork: &tcmu_unmap_work, delay: msecs_to_jiffies(m: 5000));
3261	}
3262
3263	static void check_timedout_devices(void)
3264	{
3265	struct tcmu_dev *udev, *tmp_dev;
3266	struct tcmu_cmd *cmd, *tmp_cmd;
3267	LIST_HEAD(devs);
3268
3269	spin_lock_bh(lock: &timed_out_udevs_lock);
3270	list_splice_init(list: &timed_out_udevs, head: &devs);
3271
3272	list_for_each_entry_safe(udev, tmp_dev, &devs, timedout_entry) {
3273	list_del_init(entry: &udev->timedout_entry);
3274	spin_unlock_bh(lock: &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(queue: &udev->inflight_queue,
3289	timer: &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(queue: &udev->qfull_queue, timer: &udev->qfull_timer);
3296
3297	mutex_unlock(lock: &udev->cmdr_lock);
3298
3299	spin_lock_bh(lock: &timed_out_udevs_lock);
3300	}
3301
3302	spin_unlock_bh(lock: &timed_out_udevs_lock);
3303	}
3304
3305	static void tcmu_unmap_work_fn(struct work_struct *work)
3306	{
3307	check_timedout_devices();
3308	find_free_blocks();
3309	}
3310
3311	static int __init tcmu_module_init(void)
3312	{
3313	int ret, i, k, len = 0;
3314
3315	BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry) % TCMU_OP_ALIGN_SIZE) != 0);
3316
3317	INIT_DELAYED_WORK(&tcmu_unmap_work, tcmu_unmap_work_fn);
3318
3319	tcmu_cmd_cache = kmem_cache_create("tcmu_cmd_cache",
3320	sizeof(struct tcmu_cmd),
3321	__alignof__(struct tcmu_cmd),
3322	0, NULL);
3323	if (!tcmu_cmd_cache)
3324	return -ENOMEM;
3325
3326	tcmu_root_device = root_device_register("tcm_user");
3327	if (IS_ERR(ptr: tcmu_root_device)) {
3328	ret = PTR_ERR(ptr: tcmu_root_device);
3329	goto out_free_cache;
3330	}
3331
3332	ret = genl_register_family(family: &tcmu_genl_family);
3333	if (ret < 0) {
3334	goto out_unreg_device;
3335	}
3336
3337	for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
3338	len += sizeof(struct configfs_attribute *);
3339	for (i = 0; passthrough_pr_attrib_attrs[i] != NULL; i++)
3340	len += sizeof(struct configfs_attribute *);
3341	for (i = 0; tcmu_attrib_attrs[i] != NULL; i++)
3342	len += sizeof(struct configfs_attribute *);
3343	len += sizeof(struct configfs_attribute *);
3344
3345	tcmu_attrs = kzalloc(len, GFP_KERNEL);
3346	if (!tcmu_attrs) {
3347	ret = -ENOMEM;
3348	goto out_unreg_genl;
3349	}
3350
3351	for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
3352	tcmu_attrs[i] = passthrough_attrib_attrs[i];
3353	for (k = 0; passthrough_pr_attrib_attrs[k] != NULL; k++)
3354	tcmu_attrs[i++] = passthrough_pr_attrib_attrs[k];
3355	for (k = 0; tcmu_attrib_attrs[k] != NULL; k++)
3356	tcmu_attrs[i++] = tcmu_attrib_attrs[k];
3357	tcmu_ops.tb_dev_attrib_attrs = tcmu_attrs;
3358
3359	ret = transport_backend_register(&tcmu_ops);
3360	if (ret)
3361	goto out_attrs;
3362
3363	return 0;
3364
3365	out_attrs:
3366	kfree(objp: tcmu_attrs);
3367	out_unreg_genl:
3368	genl_unregister_family(family: &tcmu_genl_family);
3369	out_unreg_device:
3370	root_device_unregister(root: tcmu_root_device);
3371	out_free_cache:
3372	kmem_cache_destroy(s: tcmu_cmd_cache);
3373
3374	return ret;
3375	}
3376
3377	static void __exit tcmu_module_exit(void)
3378	{
3379	cancel_delayed_work_sync(dwork: &tcmu_unmap_work);
3380	target_backend_unregister(&tcmu_ops);
3381	kfree(objp: tcmu_attrs);
3382	genl_unregister_family(family: &tcmu_genl_family);
3383	root_device_unregister(root: tcmu_root_device);
3384	kmem_cache_destroy(s: tcmu_cmd_cache);
3385	}
3386
3387	MODULE_DESCRIPTION("TCM USER subsystem plugin");
3388	MODULE_AUTHOR("Shaohua Li <shli@kernel.org>");
3389	MODULE_AUTHOR("Andy Grover <agrover@redhat.com>");
3390	MODULE_LICENSE("GPL");
3391
3392	module_init(tcmu_module_init);
3393	module_exit(tcmu_module_exit);
3394