1 /*******************************************************************************
2  * Filename: target_core_xcopy.c
3  *
4  * This file contains support for SPC-4 Extended-Copy offload with generic
5  * TCM backends.
6  *
7  * Copyright (c) 2011-2013 Datera, Inc. All rights reserved.
8  *
9  * Author:
10  * Nicholas A. Bellinger <nab@daterainc.com>
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation; either version 2 of the License, or
15  * (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  *
22  ******************************************************************************/
23 
24 #include <linux/slab.h>
25 #include <linux/spinlock.h>
26 #include <linux/list.h>
27 #include <linux/configfs.h>
28 #include <scsi/scsi.h>
29 #include <scsi/scsi_cmnd.h>
30 #include <asm/unaligned.h>
31 
32 #include <target/target_core_base.h>
33 #include <target/target_core_backend.h>
34 #include <target/target_core_fabric.h>
35 #include <target/target_core_configfs.h>
36 
37 #include "target_core_pr.h"
38 #include "target_core_ua.h"
39 #include "target_core_xcopy.h"
40 
41 static struct workqueue_struct *xcopy_wq = NULL;
42 /*
43  * From target_core_spc.c
44  */
45 extern void spc_parse_naa_6h_vendor_specific(struct se_device *, unsigned char *);
46 /*
47  * From target_core_device.c
48  */
49 extern struct mutex g_device_mutex;
50 extern struct list_head g_device_list;
51 /*
52  * From target_core_configfs.c
53  */
54 extern struct configfs_subsystem *target_core_subsystem[];
55 
56 static int target_xcopy_gen_naa_ieee(struct se_device *dev, unsigned char *buf)
57 {
58 	int off = 0;
59 
60 	buf[off++] = (0x6 << 4);
61 	buf[off++] = 0x01;
62 	buf[off++] = 0x40;
63 	buf[off] = (0x5 << 4);
64 
65 	spc_parse_naa_6h_vendor_specific(dev, &buf[off]);
66 	return 0;
67 }
68 
69 static int target_xcopy_locate_se_dev_e4(struct se_cmd *se_cmd, struct xcopy_op *xop,
70 					bool src)
71 {
72 	struct se_device *se_dev;
73 	struct configfs_subsystem *subsys = target_core_subsystem[0];
74 	unsigned char tmp_dev_wwn[XCOPY_NAA_IEEE_REGEX_LEN], *dev_wwn;
75 	int rc;
76 
77 	if (src == true)
78 		dev_wwn = &xop->dst_tid_wwn[0];
79 	else
80 		dev_wwn = &xop->src_tid_wwn[0];
81 
82 	mutex_lock(&g_device_mutex);
83 	list_for_each_entry(se_dev, &g_device_list, g_dev_node) {
84 
85 		if (!se_dev->dev_attrib.emulate_3pc)
86 			continue;
87 
88 		memset(&tmp_dev_wwn[0], 0, XCOPY_NAA_IEEE_REGEX_LEN);
89 		target_xcopy_gen_naa_ieee(se_dev, &tmp_dev_wwn[0]);
90 
91 		rc = memcmp(&tmp_dev_wwn[0], dev_wwn, XCOPY_NAA_IEEE_REGEX_LEN);
92 		if (rc != 0)
93 			continue;
94 
95 		if (src == true) {
96 			xop->dst_dev = se_dev;
97 			pr_debug("XCOPY 0xe4: Setting xop->dst_dev: %p from located"
98 				" se_dev\n", xop->dst_dev);
99 		} else {
100 			xop->src_dev = se_dev;
101 			pr_debug("XCOPY 0xe4: Setting xop->src_dev: %p from located"
102 				" se_dev\n", xop->src_dev);
103 		}
104 
105 		rc = configfs_depend_item(subsys,
106 				&se_dev->dev_group.cg_item);
107 		if (rc != 0) {
108 			pr_err("configfs_depend_item attempt failed:"
109 				" %d for se_dev: %p\n", rc, se_dev);
110 			mutex_unlock(&g_device_mutex);
111 			return rc;
112 		}
113 
114 		pr_debug("Called configfs_depend_item for subsys: %p se_dev: %p"
115 			" se_dev->se_dev_group: %p\n", subsys, se_dev,
116 			&se_dev->dev_group);
117 
118 		mutex_unlock(&g_device_mutex);
119 		return 0;
120 	}
121 	mutex_unlock(&g_device_mutex);
122 
123 	pr_err("Unable to locate 0xe4 descriptor for EXTENDED_COPY\n");
124 	return -EINVAL;
125 }
126 
127 static int target_xcopy_parse_tiddesc_e4(struct se_cmd *se_cmd, struct xcopy_op *xop,
128 				unsigned char *p, bool src)
129 {
130 	unsigned char *desc = p;
131 	unsigned short ript;
132 	u8 desig_len;
133 	/*
134 	 * Extract RELATIVE INITIATOR PORT IDENTIFIER
135 	 */
136 	ript = get_unaligned_be16(&desc[2]);
137 	pr_debug("XCOPY 0xe4: RELATIVE INITIATOR PORT IDENTIFIER: %hu\n", ript);
138 	/*
139 	 * Check for supported code set, association, and designator type
140 	 */
141 	if ((desc[4] & 0x0f) != 0x1) {
142 		pr_err("XCOPY 0xe4: code set of non binary type not supported\n");
143 		return -EINVAL;
144 	}
145 	if ((desc[5] & 0x30) != 0x00) {
146 		pr_err("XCOPY 0xe4: association other than LUN not supported\n");
147 		return -EINVAL;
148 	}
149 	if ((desc[5] & 0x0f) != 0x3) {
150 		pr_err("XCOPY 0xe4: designator type unsupported: 0x%02x\n",
151 				(desc[5] & 0x0f));
152 		return -EINVAL;
153 	}
154 	/*
155 	 * Check for matching 16 byte length for NAA IEEE Registered Extended
156 	 * Assigned designator
157 	 */
158 	desig_len = desc[7];
159 	if (desig_len != 16) {
160 		pr_err("XCOPY 0xe4: invalid desig_len: %d\n", (int)desig_len);
161 		return -EINVAL;
162 	}
163 	pr_debug("XCOPY 0xe4: desig_len: %d\n", (int)desig_len);
164 	/*
165 	 * Check for NAA IEEE Registered Extended Assigned header..
166 	 */
167 	if ((desc[8] & 0xf0) != 0x60) {
168 		pr_err("XCOPY 0xe4: Unsupported DESIGNATOR TYPE: 0x%02x\n",
169 					(desc[8] & 0xf0));
170 		return -EINVAL;
171 	}
172 
173 	if (src == true) {
174 		memcpy(&xop->src_tid_wwn[0], &desc[8], XCOPY_NAA_IEEE_REGEX_LEN);
175 		/*
176 		 * Determine if the source designator matches the local device
177 		 */
178 		if (!memcmp(&xop->local_dev_wwn[0], &xop->src_tid_wwn[0],
179 				XCOPY_NAA_IEEE_REGEX_LEN)) {
180 			xop->op_origin = XCOL_SOURCE_RECV_OP;
181 			xop->src_dev = se_cmd->se_dev;
182 			pr_debug("XCOPY 0xe4: Set xop->src_dev %p from source"
183 					" received xop\n", xop->src_dev);
184 		}
185 	} else {
186 		memcpy(&xop->dst_tid_wwn[0], &desc[8], XCOPY_NAA_IEEE_REGEX_LEN);
187 		/*
188 		 * Determine if the destination designator matches the local device
189 		 */
190 		if (!memcmp(&xop->local_dev_wwn[0], &xop->dst_tid_wwn[0],
191 				XCOPY_NAA_IEEE_REGEX_LEN)) {
192 			xop->op_origin = XCOL_DEST_RECV_OP;
193 			xop->dst_dev = se_cmd->se_dev;
194 			pr_debug("XCOPY 0xe4: Set xop->dst_dev: %p from destination"
195 				" received xop\n", xop->dst_dev);
196 		}
197 	}
198 
199 	return 0;
200 }
201 
202 static int target_xcopy_parse_target_descriptors(struct se_cmd *se_cmd,
203 				struct xcopy_op *xop, unsigned char *p,
204 				unsigned short tdll)
205 {
206 	struct se_device *local_dev = se_cmd->se_dev;
207 	unsigned char *desc = p;
208 	int offset = tdll % XCOPY_TARGET_DESC_LEN, rc, ret = 0;
209 	unsigned short start = 0;
210 	bool src = true;
211 
212 	if (offset != 0) {
213 		pr_err("XCOPY target descriptor list length is not"
214 			" multiple of %d\n", XCOPY_TARGET_DESC_LEN);
215 		return -EINVAL;
216 	}
217 	if (tdll > 64) {
218 		pr_err("XCOPY target descriptor supports a maximum"
219 			" two src/dest descriptors, tdll: %hu too large..\n", tdll);
220 		return -EINVAL;
221 	}
222 	/*
223 	 * Generate an IEEE Registered Extended designator based upon the
224 	 * se_device the XCOPY was received upon..
225 	 */
226 	memset(&xop->local_dev_wwn[0], 0, XCOPY_NAA_IEEE_REGEX_LEN);
227 	target_xcopy_gen_naa_ieee(local_dev, &xop->local_dev_wwn[0]);
228 
229 	while (start < tdll) {
230 		/*
231 		 * Check target descriptor identification with 0xE4 type with
232 		 * use VPD 0x83 WWPN matching ..
233 		 */
234 		switch (desc[0]) {
235 		case 0xe4:
236 			rc = target_xcopy_parse_tiddesc_e4(se_cmd, xop,
237 							&desc[0], src);
238 			if (rc != 0)
239 				goto out;
240 			/*
241 			 * Assume target descriptors are in source -> destination order..
242 			 */
243 			if (src == true)
244 				src = false;
245 			else
246 				src = true;
247 			start += XCOPY_TARGET_DESC_LEN;
248 			desc += XCOPY_TARGET_DESC_LEN;
249 			ret++;
250 			break;
251 		default:
252 			pr_err("XCOPY unsupported descriptor type code:"
253 					" 0x%02x\n", desc[0]);
254 			goto out;
255 		}
256 	}
257 
258 	if (xop->op_origin == XCOL_SOURCE_RECV_OP)
259 		rc = target_xcopy_locate_se_dev_e4(se_cmd, xop, true);
260 	else
261 		rc = target_xcopy_locate_se_dev_e4(se_cmd, xop, false);
262 
263 	if (rc < 0)
264 		goto out;
265 
266 	pr_debug("XCOPY TGT desc: Source dev: %p NAA IEEE WWN: 0x%16phN\n",
267 		 xop->src_dev, &xop->src_tid_wwn[0]);
268 	pr_debug("XCOPY TGT desc: Dest dev: %p NAA IEEE WWN: 0x%16phN\n",
269 		 xop->dst_dev, &xop->dst_tid_wwn[0]);
270 
271 	return ret;
272 
273 out:
274 	return -EINVAL;
275 }
276 
277 static int target_xcopy_parse_segdesc_02(struct se_cmd *se_cmd, struct xcopy_op *xop,
278 					unsigned char *p)
279 {
280 	unsigned char *desc = p;
281 	int dc = (desc[1] & 0x02);
282 	unsigned short desc_len;
283 
284 	desc_len = get_unaligned_be16(&desc[2]);
285 	if (desc_len != 0x18) {
286 		pr_err("XCOPY segment desc 0x02: Illegal desc_len:"
287 				" %hu\n", desc_len);
288 		return -EINVAL;
289 	}
290 
291 	xop->stdi = get_unaligned_be16(&desc[4]);
292 	xop->dtdi = get_unaligned_be16(&desc[6]);
293 	pr_debug("XCOPY seg desc 0x02: desc_len: %hu stdi: %hu dtdi: %hu, DC: %d\n",
294 		desc_len, xop->stdi, xop->dtdi, dc);
295 
296 	xop->nolb = get_unaligned_be16(&desc[10]);
297 	xop->src_lba = get_unaligned_be64(&desc[12]);
298 	xop->dst_lba = get_unaligned_be64(&desc[20]);
299 	pr_debug("XCOPY seg desc 0x02: nolb: %hu src_lba: %llu dst_lba: %llu\n",
300 		xop->nolb, (unsigned long long)xop->src_lba,
301 		(unsigned long long)xop->dst_lba);
302 
303 	if (dc != 0) {
304 		xop->dbl = (desc[29] & 0xff) << 16;
305 		xop->dbl |= (desc[30] & 0xff) << 8;
306 		xop->dbl |= desc[31] & 0xff;
307 
308 		pr_debug("XCOPY seg desc 0x02: DC=1 w/ dbl: %u\n", xop->dbl);
309 	}
310 	return 0;
311 }
312 
313 static int target_xcopy_parse_segment_descriptors(struct se_cmd *se_cmd,
314 				struct xcopy_op *xop, unsigned char *p,
315 				unsigned int sdll)
316 {
317 	unsigned char *desc = p;
318 	unsigned int start = 0;
319 	int offset = sdll % XCOPY_SEGMENT_DESC_LEN, rc, ret = 0;
320 
321 	if (offset != 0) {
322 		pr_err("XCOPY segment descriptor list length is not"
323 			" multiple of %d\n", XCOPY_SEGMENT_DESC_LEN);
324 		return -EINVAL;
325 	}
326 
327 	while (start < sdll) {
328 		/*
329 		 * Check segment descriptor type code for block -> block
330 		 */
331 		switch (desc[0]) {
332 		case 0x02:
333 			rc = target_xcopy_parse_segdesc_02(se_cmd, xop, desc);
334 			if (rc < 0)
335 				goto out;
336 
337 			ret++;
338 			start += XCOPY_SEGMENT_DESC_LEN;
339 			desc += XCOPY_SEGMENT_DESC_LEN;
340 			break;
341 		default:
342 			pr_err("XCOPY unspported segment descriptor"
343 				"type: 0x%02x\n", desc[0]);
344 			goto out;
345 		}
346 	}
347 
348 	return ret;
349 
350 out:
351 	return -EINVAL;
352 }
353 
354 /*
355  * Start xcopy_pt ops
356  */
357 
358 struct xcopy_pt_cmd {
359 	bool remote_port;
360 	struct se_cmd se_cmd;
361 	struct xcopy_op *xcopy_op;
362 	struct completion xpt_passthrough_sem;
363 	unsigned char sense_buffer[TRANSPORT_SENSE_BUFFER];
364 };
365 
366 static struct se_port xcopy_pt_port;
367 static struct se_portal_group xcopy_pt_tpg;
368 static struct se_session xcopy_pt_sess;
369 static struct se_node_acl xcopy_pt_nacl;
370 
371 static char *xcopy_pt_get_fabric_name(void)
372 {
373         return "xcopy-pt";
374 }
375 
376 static u32 xcopy_pt_get_tag(struct se_cmd *se_cmd)
377 {
378         return 0;
379 }
380 
381 static int xcopy_pt_get_cmd_state(struct se_cmd *se_cmd)
382 {
383         return 0;
384 }
385 
386 static void xcopy_pt_undepend_remotedev(struct xcopy_op *xop)
387 {
388 	struct configfs_subsystem *subsys = target_core_subsystem[0];
389 	struct se_device *remote_dev;
390 
391 	if (xop->op_origin == XCOL_SOURCE_RECV_OP)
392 		remote_dev = xop->dst_dev;
393 	else
394 		remote_dev = xop->src_dev;
395 
396 	pr_debug("Calling configfs_undepend_item for subsys: %p"
397 		  " remote_dev: %p remote_dev->dev_group: %p\n",
398 		  subsys, remote_dev, &remote_dev->dev_group.cg_item);
399 
400 	configfs_undepend_item(subsys, &remote_dev->dev_group.cg_item);
401 }
402 
403 static void xcopy_pt_release_cmd(struct se_cmd *se_cmd)
404 {
405 	struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,
406 				struct xcopy_pt_cmd, se_cmd);
407 
408 	kfree(xpt_cmd);
409 }
410 
411 static int xcopy_pt_check_stop_free(struct se_cmd *se_cmd)
412 {
413 	struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,
414 				struct xcopy_pt_cmd, se_cmd);
415 
416 	complete(&xpt_cmd->xpt_passthrough_sem);
417 	return 0;
418 }
419 
420 static int xcopy_pt_write_pending(struct se_cmd *se_cmd)
421 {
422 	return 0;
423 }
424 
425 static int xcopy_pt_write_pending_status(struct se_cmd *se_cmd)
426 {
427 	return 0;
428 }
429 
430 static int xcopy_pt_queue_data_in(struct se_cmd *se_cmd)
431 {
432 	return 0;
433 }
434 
435 static int xcopy_pt_queue_status(struct se_cmd *se_cmd)
436 {
437 	return 0;
438 }
439 
440 static struct target_core_fabric_ops xcopy_pt_tfo = {
441 	.get_fabric_name	= xcopy_pt_get_fabric_name,
442 	.get_task_tag		= xcopy_pt_get_tag,
443 	.get_cmd_state		= xcopy_pt_get_cmd_state,
444 	.release_cmd		= xcopy_pt_release_cmd,
445 	.check_stop_free	= xcopy_pt_check_stop_free,
446 	.write_pending		= xcopy_pt_write_pending,
447 	.write_pending_status	= xcopy_pt_write_pending_status,
448 	.queue_data_in		= xcopy_pt_queue_data_in,
449 	.queue_status		= xcopy_pt_queue_status,
450 };
451 
452 /*
453  * End xcopy_pt_ops
454  */
455 
456 int target_xcopy_setup_pt(void)
457 {
458 	xcopy_wq = alloc_workqueue("xcopy_wq", WQ_MEM_RECLAIM, 0);
459 	if (!xcopy_wq) {
460 		pr_err("Unable to allocate xcopy_wq\n");
461 		return -ENOMEM;
462 	}
463 
464 	memset(&xcopy_pt_port, 0, sizeof(struct se_port));
465 	INIT_LIST_HEAD(&xcopy_pt_port.sep_alua_list);
466 	INIT_LIST_HEAD(&xcopy_pt_port.sep_list);
467 	mutex_init(&xcopy_pt_port.sep_tg_pt_md_mutex);
468 
469 	memset(&xcopy_pt_tpg, 0, sizeof(struct se_portal_group));
470 	INIT_LIST_HEAD(&xcopy_pt_tpg.se_tpg_node);
471 	INIT_LIST_HEAD(&xcopy_pt_tpg.acl_node_list);
472 	INIT_LIST_HEAD(&xcopy_pt_tpg.tpg_sess_list);
473 
474 	xcopy_pt_port.sep_tpg = &xcopy_pt_tpg;
475 	xcopy_pt_tpg.se_tpg_tfo = &xcopy_pt_tfo;
476 
477 	memset(&xcopy_pt_nacl, 0, sizeof(struct se_node_acl));
478 	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_list);
479 	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_sess_list);
480 	memset(&xcopy_pt_sess, 0, sizeof(struct se_session));
481 	INIT_LIST_HEAD(&xcopy_pt_sess.sess_list);
482 	INIT_LIST_HEAD(&xcopy_pt_sess.sess_acl_list);
483 
484 	xcopy_pt_nacl.se_tpg = &xcopy_pt_tpg;
485 	xcopy_pt_nacl.nacl_sess = &xcopy_pt_sess;
486 
487 	xcopy_pt_sess.se_tpg = &xcopy_pt_tpg;
488 	xcopy_pt_sess.se_node_acl = &xcopy_pt_nacl;
489 
490 	return 0;
491 }
492 
493 void target_xcopy_release_pt(void)
494 {
495 	if (xcopy_wq)
496 		destroy_workqueue(xcopy_wq);
497 }
498 
499 static void target_xcopy_setup_pt_port(
500 	struct xcopy_pt_cmd *xpt_cmd,
501 	struct xcopy_op *xop,
502 	bool remote_port)
503 {
504 	struct se_cmd *ec_cmd = xop->xop_se_cmd;
505 	struct se_cmd *pt_cmd = &xpt_cmd->se_cmd;
506 
507 	if (xop->op_origin == XCOL_SOURCE_RECV_OP) {
508 		/*
509 		 * Honor destination port reservations for X-COPY PUSH emulation
510 		 * when CDB is received on local source port, and READs blocks to
511 		 * WRITE on remote destination port.
512 		 */
513 		if (remote_port) {
514 			xpt_cmd->remote_port = remote_port;
515 			pt_cmd->se_lun->lun_sep = &xcopy_pt_port;
516 			pr_debug("Setup emulated remote DEST xcopy_pt_port: %p to"
517 				" cmd->se_lun->lun_sep for X-COPY data PUSH\n",
518 				pt_cmd->se_lun->lun_sep);
519 		} else {
520 			pt_cmd->se_lun = ec_cmd->se_lun;
521 			pt_cmd->se_dev = ec_cmd->se_dev;
522 
523 			pr_debug("Honoring local SRC port from ec_cmd->se_dev:"
524 				" %p\n", pt_cmd->se_dev);
525 			pt_cmd->se_lun = ec_cmd->se_lun;
526 			pr_debug("Honoring local SRC port from ec_cmd->se_lun: %p\n",
527 				pt_cmd->se_lun);
528 		}
529 	} else {
530 		/*
531 		 * Honor source port reservation for X-COPY PULL emulation
532 		 * when CDB is received on local desintation port, and READs
533 		 * blocks from the remote source port to WRITE on local
534 		 * destination port.
535 		 */
536 		if (remote_port) {
537 			xpt_cmd->remote_port = remote_port;
538 			pt_cmd->se_lun->lun_sep = &xcopy_pt_port;
539 			pr_debug("Setup emulated remote SRC xcopy_pt_port: %p to"
540 				" cmd->se_lun->lun_sep for X-COPY data PULL\n",
541 				pt_cmd->se_lun->lun_sep);
542 		} else {
543 			pt_cmd->se_lun = ec_cmd->se_lun;
544 			pt_cmd->se_dev = ec_cmd->se_dev;
545 
546 			pr_debug("Honoring local DST port from ec_cmd->se_dev:"
547 				" %p\n", pt_cmd->se_dev);
548 			pt_cmd->se_lun = ec_cmd->se_lun;
549 			pr_debug("Honoring local DST port from ec_cmd->se_lun: %p\n",
550 				pt_cmd->se_lun);
551 		}
552 	}
553 }
554 
555 static int target_xcopy_init_pt_lun(
556 	struct xcopy_pt_cmd *xpt_cmd,
557 	struct xcopy_op *xop,
558 	struct se_device *se_dev,
559 	struct se_cmd *pt_cmd,
560 	bool remote_port)
561 {
562 	/*
563 	 * Don't allocate + init an pt_cmd->se_lun if honoring local port for
564 	 * reservations.  The pt_cmd->se_lun pointer will be setup from within
565 	 * target_xcopy_setup_pt_port()
566 	 */
567 	if (remote_port == false) {
568 		pt_cmd->se_cmd_flags |= SCF_SE_LUN_CMD | SCF_CMD_XCOPY_PASSTHROUGH;
569 		return 0;
570 	}
571 
572 	pt_cmd->se_lun = &se_dev->xcopy_lun;
573 	pt_cmd->se_dev = se_dev;
574 
575 	pr_debug("Setup emulated se_dev: %p from se_dev\n", pt_cmd->se_dev);
576 	pt_cmd->se_cmd_flags |= SCF_SE_LUN_CMD | SCF_CMD_XCOPY_PASSTHROUGH;
577 
578 	pr_debug("Setup emulated se_dev: %p to pt_cmd->se_lun->lun_se_dev\n",
579 		pt_cmd->se_lun->lun_se_dev);
580 
581 	return 0;
582 }
583 
584 static int target_xcopy_setup_pt_cmd(
585 	struct xcopy_pt_cmd *xpt_cmd,
586 	struct xcopy_op *xop,
587 	struct se_device *se_dev,
588 	unsigned char *cdb,
589 	bool remote_port,
590 	bool alloc_mem)
591 {
592 	struct se_cmd *cmd = &xpt_cmd->se_cmd;
593 	sense_reason_t sense_rc;
594 	int ret = 0, rc;
595 	/*
596 	 * Setup LUN+port to honor reservations based upon xop->op_origin for
597 	 * X-COPY PUSH or X-COPY PULL based upon where the CDB was received.
598 	 */
599 	rc = target_xcopy_init_pt_lun(xpt_cmd, xop, se_dev, cmd, remote_port);
600 	if (rc < 0) {
601 		ret = rc;
602 		goto out;
603 	}
604 	xpt_cmd->xcopy_op = xop;
605 	target_xcopy_setup_pt_port(xpt_cmd, xop, remote_port);
606 
607 	sense_rc = target_setup_cmd_from_cdb(cmd, cdb);
608 	if (sense_rc) {
609 		ret = -EINVAL;
610 		goto out;
611 	}
612 
613 	if (alloc_mem) {
614 		rc = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
615 				      cmd->data_length, false);
616 		if (rc < 0) {
617 			ret = rc;
618 			goto out;
619 		}
620 		/*
621 		 * Set this bit so that transport_free_pages() allows the
622 		 * caller to release SGLs + physical memory allocated by
623 		 * transport_generic_get_mem()..
624 		 */
625 		cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
626 	} else {
627 		/*
628 		 * Here the previously allocated SGLs for the internal READ
629 		 * are mapped zero-copy to the internal WRITE.
630 		 */
631 		sense_rc = transport_generic_map_mem_to_cmd(cmd,
632 					xop->xop_data_sg, xop->xop_data_nents,
633 					NULL, 0);
634 		if (sense_rc) {
635 			ret = -EINVAL;
636 			goto out;
637 		}
638 
639 		pr_debug("Setup PASSTHROUGH_NOALLOC t_data_sg: %p t_data_nents:"
640 			 " %u\n", cmd->t_data_sg, cmd->t_data_nents);
641 	}
642 
643 	return 0;
644 
645 out:
646 	return ret;
647 }
648 
649 static int target_xcopy_issue_pt_cmd(struct xcopy_pt_cmd *xpt_cmd)
650 {
651 	struct se_cmd *se_cmd = &xpt_cmd->se_cmd;
652 	sense_reason_t sense_rc;
653 
654 	sense_rc = transport_generic_new_cmd(se_cmd);
655 	if (sense_rc)
656 		return -EINVAL;
657 
658 	if (se_cmd->data_direction == DMA_TO_DEVICE)
659 		target_execute_cmd(se_cmd);
660 
661 	wait_for_completion_interruptible(&xpt_cmd->xpt_passthrough_sem);
662 
663 	pr_debug("target_xcopy_issue_pt_cmd(): SCSI status: 0x%02x\n",
664 			se_cmd->scsi_status);
665 
666 	return (se_cmd->scsi_status) ? -EINVAL : 0;
667 }
668 
669 static int target_xcopy_read_source(
670 	struct se_cmd *ec_cmd,
671 	struct xcopy_op *xop,
672 	struct se_device *src_dev,
673 	sector_t src_lba,
674 	u32 src_sectors)
675 {
676 	struct xcopy_pt_cmd *xpt_cmd;
677 	struct se_cmd *se_cmd;
678 	u32 length = (src_sectors * src_dev->dev_attrib.block_size);
679 	int rc;
680 	unsigned char cdb[16];
681 	bool remote_port = (xop->op_origin == XCOL_DEST_RECV_OP);
682 
683 	xpt_cmd = kzalloc(sizeof(struct xcopy_pt_cmd), GFP_KERNEL);
684 	if (!xpt_cmd) {
685 		pr_err("Unable to allocate xcopy_pt_cmd\n");
686 		return -ENOMEM;
687 	}
688 	init_completion(&xpt_cmd->xpt_passthrough_sem);
689 	se_cmd = &xpt_cmd->se_cmd;
690 
691 	memset(&cdb[0], 0, 16);
692 	cdb[0] = READ_16;
693 	put_unaligned_be64(src_lba, &cdb[2]);
694 	put_unaligned_be32(src_sectors, &cdb[10]);
695 	pr_debug("XCOPY: Built READ_16: LBA: %llu Sectors: %u Length: %u\n",
696 		(unsigned long long)src_lba, src_sectors, length);
697 
698 	transport_init_se_cmd(se_cmd, &xcopy_pt_tfo, NULL, length,
699 			      DMA_FROM_DEVICE, 0, &xpt_cmd->sense_buffer[0]);
700 	xop->src_pt_cmd = xpt_cmd;
701 
702 	rc = target_xcopy_setup_pt_cmd(xpt_cmd, xop, src_dev, &cdb[0],
703 				remote_port, true);
704 	if (rc < 0) {
705 		transport_generic_free_cmd(se_cmd, 0);
706 		return rc;
707 	}
708 
709 	xop->xop_data_sg = se_cmd->t_data_sg;
710 	xop->xop_data_nents = se_cmd->t_data_nents;
711 	pr_debug("XCOPY-READ: Saved xop->xop_data_sg: %p, num: %u for READ"
712 		" memory\n", xop->xop_data_sg, xop->xop_data_nents);
713 
714 	rc = target_xcopy_issue_pt_cmd(xpt_cmd);
715 	if (rc < 0) {
716 		transport_generic_free_cmd(se_cmd, 0);
717 		return rc;
718 	}
719 	/*
720 	 * Clear off the allocated t_data_sg, that has been saved for
721 	 * zero-copy WRITE submission reuse in struct xcopy_op..
722 	 */
723 	se_cmd->t_data_sg = NULL;
724 	se_cmd->t_data_nents = 0;
725 
726 	return 0;
727 }
728 
729 static int target_xcopy_write_destination(
730 	struct se_cmd *ec_cmd,
731 	struct xcopy_op *xop,
732 	struct se_device *dst_dev,
733 	sector_t dst_lba,
734 	u32 dst_sectors)
735 {
736 	struct xcopy_pt_cmd *xpt_cmd;
737 	struct se_cmd *se_cmd;
738 	u32 length = (dst_sectors * dst_dev->dev_attrib.block_size);
739 	int rc;
740 	unsigned char cdb[16];
741 	bool remote_port = (xop->op_origin == XCOL_SOURCE_RECV_OP);
742 
743 	xpt_cmd = kzalloc(sizeof(struct xcopy_pt_cmd), GFP_KERNEL);
744 	if (!xpt_cmd) {
745 		pr_err("Unable to allocate xcopy_pt_cmd\n");
746 		return -ENOMEM;
747 	}
748 	init_completion(&xpt_cmd->xpt_passthrough_sem);
749 	se_cmd = &xpt_cmd->se_cmd;
750 
751 	memset(&cdb[0], 0, 16);
752 	cdb[0] = WRITE_16;
753 	put_unaligned_be64(dst_lba, &cdb[2]);
754 	put_unaligned_be32(dst_sectors, &cdb[10]);
755 	pr_debug("XCOPY: Built WRITE_16: LBA: %llu Sectors: %u Length: %u\n",
756 		(unsigned long long)dst_lba, dst_sectors, length);
757 
758 	transport_init_se_cmd(se_cmd, &xcopy_pt_tfo, NULL, length,
759 			      DMA_TO_DEVICE, 0, &xpt_cmd->sense_buffer[0]);
760 	xop->dst_pt_cmd = xpt_cmd;
761 
762 	rc = target_xcopy_setup_pt_cmd(xpt_cmd, xop, dst_dev, &cdb[0],
763 				remote_port, false);
764 	if (rc < 0) {
765 		struct se_cmd *src_cmd = &xop->src_pt_cmd->se_cmd;
766 		/*
767 		 * If the failure happened before the t_mem_list hand-off in
768 		 * target_xcopy_setup_pt_cmd(), Reset memory + clear flag so that
769 		 * core releases this memory on error during X-COPY WRITE I/O.
770 		 */
771 		src_cmd->se_cmd_flags &= ~SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
772 		src_cmd->t_data_sg = xop->xop_data_sg;
773 		src_cmd->t_data_nents = xop->xop_data_nents;
774 
775 		transport_generic_free_cmd(se_cmd, 0);
776 		return rc;
777 	}
778 
779 	rc = target_xcopy_issue_pt_cmd(xpt_cmd);
780 	if (rc < 0) {
781 		se_cmd->se_cmd_flags &= ~SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
782 		transport_generic_free_cmd(se_cmd, 0);
783 		return rc;
784 	}
785 
786 	return 0;
787 }
788 
789 static void target_xcopy_do_work(struct work_struct *work)
790 {
791 	struct xcopy_op *xop = container_of(work, struct xcopy_op, xop_work);
792 	struct se_device *src_dev = xop->src_dev, *dst_dev = xop->dst_dev;
793 	struct se_cmd *ec_cmd = xop->xop_se_cmd;
794 	sector_t src_lba = xop->src_lba, dst_lba = xop->dst_lba, end_lba;
795 	unsigned int max_sectors;
796 	int rc;
797 	unsigned short nolb = xop->nolb, cur_nolb, max_nolb, copied_nolb = 0;
798 
799 	end_lba = src_lba + nolb;
800 	/*
801 	 * Break up XCOPY I/O into hw_max_sectors sized I/O based on the
802 	 * smallest max_sectors between src_dev + dev_dev, or
803 	 */
804 	max_sectors = min(src_dev->dev_attrib.hw_max_sectors,
805 			  dst_dev->dev_attrib.hw_max_sectors);
806 	max_sectors = min_t(u32, max_sectors, XCOPY_MAX_SECTORS);
807 
808 	max_nolb = min_t(u16, max_sectors, ((u16)(~0U)));
809 
810 	pr_debug("target_xcopy_do_work: nolb: %hu, max_nolb: %hu end_lba: %llu\n",
811 			nolb, max_nolb, (unsigned long long)end_lba);
812 	pr_debug("target_xcopy_do_work: Starting src_lba: %llu, dst_lba: %llu\n",
813 			(unsigned long long)src_lba, (unsigned long long)dst_lba);
814 
815 	while (src_lba < end_lba) {
816 		cur_nolb = min(nolb, max_nolb);
817 
818 		pr_debug("target_xcopy_do_work: Calling read src_dev: %p src_lba: %llu,"
819 			" cur_nolb: %hu\n", src_dev, (unsigned long long)src_lba, cur_nolb);
820 
821 		rc = target_xcopy_read_source(ec_cmd, xop, src_dev, src_lba, cur_nolb);
822 		if (rc < 0)
823 			goto out;
824 
825 		src_lba += cur_nolb;
826 		pr_debug("target_xcopy_do_work: Incremented READ src_lba to %llu\n",
827 				(unsigned long long)src_lba);
828 
829 		pr_debug("target_xcopy_do_work: Calling write dst_dev: %p dst_lba: %llu,"
830 			" cur_nolb: %hu\n", dst_dev, (unsigned long long)dst_lba, cur_nolb);
831 
832 		rc = target_xcopy_write_destination(ec_cmd, xop, dst_dev,
833 						dst_lba, cur_nolb);
834 		if (rc < 0) {
835 			transport_generic_free_cmd(&xop->src_pt_cmd->se_cmd, 0);
836 			goto out;
837 		}
838 
839 		dst_lba += cur_nolb;
840 		pr_debug("target_xcopy_do_work: Incremented WRITE dst_lba to %llu\n",
841 				(unsigned long long)dst_lba);
842 
843 		copied_nolb += cur_nolb;
844 		nolb -= cur_nolb;
845 
846 		transport_generic_free_cmd(&xop->src_pt_cmd->se_cmd, 0);
847 		xop->dst_pt_cmd->se_cmd.se_cmd_flags &= ~SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
848 
849 		transport_generic_free_cmd(&xop->dst_pt_cmd->se_cmd, 0);
850 	}
851 
852 	xcopy_pt_undepend_remotedev(xop);
853 	kfree(xop);
854 
855 	pr_debug("target_xcopy_do_work: Final src_lba: %llu, dst_lba: %llu\n",
856 		(unsigned long long)src_lba, (unsigned long long)dst_lba);
857 	pr_debug("target_xcopy_do_work: Blocks copied: %hu, Bytes Copied: %u\n",
858 		copied_nolb, copied_nolb * dst_dev->dev_attrib.block_size);
859 
860 	pr_debug("target_xcopy_do_work: Setting X-COPY GOOD status -> sending response\n");
861 	target_complete_cmd(ec_cmd, SAM_STAT_GOOD);
862 	return;
863 
864 out:
865 	xcopy_pt_undepend_remotedev(xop);
866 	kfree(xop);
867 
868 	pr_warn("target_xcopy_do_work: Setting X-COPY CHECK_CONDITION -> sending response\n");
869 	ec_cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
870 	target_complete_cmd(ec_cmd, SAM_STAT_CHECK_CONDITION);
871 }
872 
873 sense_reason_t target_do_xcopy(struct se_cmd *se_cmd)
874 {
875 	struct se_device *dev = se_cmd->se_dev;
876 	struct xcopy_op *xop = NULL;
877 	unsigned char *p = NULL, *seg_desc;
878 	unsigned int list_id, list_id_usage, sdll, inline_dl, sa;
879 	sense_reason_t ret = TCM_INVALID_PARAMETER_LIST;
880 	int rc;
881 	unsigned short tdll;
882 
883 	if (!dev->dev_attrib.emulate_3pc) {
884 		pr_err("EXTENDED_COPY operation explicitly disabled\n");
885 		return TCM_UNSUPPORTED_SCSI_OPCODE;
886 	}
887 
888 	sa = se_cmd->t_task_cdb[1] & 0x1f;
889 	if (sa != 0x00) {
890 		pr_err("EXTENDED_COPY(LID4) not supported\n");
891 		return TCM_UNSUPPORTED_SCSI_OPCODE;
892 	}
893 
894 	xop = kzalloc(sizeof(struct xcopy_op), GFP_KERNEL);
895 	if (!xop) {
896 		pr_err("Unable to allocate xcopy_op\n");
897 		return TCM_OUT_OF_RESOURCES;
898 	}
899 	xop->xop_se_cmd = se_cmd;
900 
901 	p = transport_kmap_data_sg(se_cmd);
902 	if (!p) {
903 		pr_err("transport_kmap_data_sg() failed in target_do_xcopy\n");
904 		kfree(xop);
905 		return TCM_OUT_OF_RESOURCES;
906 	}
907 
908 	list_id = p[0];
909 	list_id_usage = (p[1] & 0x18) >> 3;
910 
911 	/*
912 	 * Determine TARGET DESCRIPTOR LIST LENGTH + SEGMENT DESCRIPTOR LIST LENGTH
913 	 */
914 	tdll = get_unaligned_be16(&p[2]);
915 	sdll = get_unaligned_be32(&p[8]);
916 
917 	inline_dl = get_unaligned_be32(&p[12]);
918 	if (inline_dl != 0) {
919 		pr_err("XCOPY with non zero inline data length\n");
920 		goto out;
921 	}
922 
923 	pr_debug("Processing XCOPY with list_id: 0x%02x list_id_usage: 0x%02x"
924 		" tdll: %hu sdll: %u inline_dl: %u\n", list_id, list_id_usage,
925 		tdll, sdll, inline_dl);
926 
927 	rc = target_xcopy_parse_target_descriptors(se_cmd, xop, &p[16], tdll);
928 	if (rc <= 0)
929 		goto out;
930 
931 	if (xop->src_dev->dev_attrib.block_size !=
932 	    xop->dst_dev->dev_attrib.block_size) {
933 		pr_err("XCOPY: Non matching src_dev block_size: %u + dst_dev"
934 		       " block_size: %u currently unsupported\n",
935 			xop->src_dev->dev_attrib.block_size,
936 			xop->dst_dev->dev_attrib.block_size);
937 		xcopy_pt_undepend_remotedev(xop);
938 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
939 		goto out;
940 	}
941 
942 	pr_debug("XCOPY: Processed %d target descriptors, length: %u\n", rc,
943 				rc * XCOPY_TARGET_DESC_LEN);
944 	seg_desc = &p[16];
945 	seg_desc += (rc * XCOPY_TARGET_DESC_LEN);
946 
947 	rc = target_xcopy_parse_segment_descriptors(se_cmd, xop, seg_desc, sdll);
948 	if (rc <= 0) {
949 		xcopy_pt_undepend_remotedev(xop);
950 		goto out;
951 	}
952 	transport_kunmap_data_sg(se_cmd);
953 
954 	pr_debug("XCOPY: Processed %d segment descriptors, length: %u\n", rc,
955 				rc * XCOPY_SEGMENT_DESC_LEN);
956 	INIT_WORK(&xop->xop_work, target_xcopy_do_work);
957 	queue_work(xcopy_wq, &xop->xop_work);
958 	return TCM_NO_SENSE;
959 
960 out:
961 	if (p)
962 		transport_kunmap_data_sg(se_cmd);
963 	kfree(xop);
964 	return ret;
965 }
966 
967 static sense_reason_t target_rcr_operating_parameters(struct se_cmd *se_cmd)
968 {
969 	unsigned char *p;
970 
971 	p = transport_kmap_data_sg(se_cmd);
972 	if (!p) {
973 		pr_err("transport_kmap_data_sg failed in"
974 		       " target_rcr_operating_parameters\n");
975 		return TCM_OUT_OF_RESOURCES;
976 	}
977 
978 	if (se_cmd->data_length < 54) {
979 		pr_err("Receive Copy Results Op Parameters length"
980 		       " too small: %u\n", se_cmd->data_length);
981 		transport_kunmap_data_sg(se_cmd);
982 		return TCM_INVALID_CDB_FIELD;
983 	}
984 	/*
985 	 * Set SNLID=1 (Supports no List ID)
986 	 */
987 	p[4] = 0x1;
988 	/*
989 	 * MAXIMUM TARGET DESCRIPTOR COUNT
990 	 */
991 	put_unaligned_be16(RCR_OP_MAX_TARGET_DESC_COUNT, &p[8]);
992 	/*
993 	 * MAXIMUM SEGMENT DESCRIPTOR COUNT
994 	 */
995 	put_unaligned_be16(RCR_OP_MAX_SG_DESC_COUNT, &p[10]);
996 	/*
997 	 * MAXIMUM DESCRIPTOR LIST LENGTH
998 	 */
999 	put_unaligned_be32(RCR_OP_MAX_DESC_LIST_LEN, &p[12]);
1000 	/*
1001 	 * MAXIMUM SEGMENT LENGTH
1002 	 */
1003 	put_unaligned_be32(RCR_OP_MAX_SEGMENT_LEN, &p[16]);
1004 	/*
1005 	 * MAXIMUM INLINE DATA LENGTH for SA 0x04 (NOT SUPPORTED)
1006 	 */
1007 	put_unaligned_be32(0x0, &p[20]);
1008 	/*
1009 	 * HELD DATA LIMIT
1010 	 */
1011 	put_unaligned_be32(0x0, &p[24]);
1012 	/*
1013 	 * MAXIMUM STREAM DEVICE TRANSFER SIZE
1014 	 */
1015 	put_unaligned_be32(0x0, &p[28]);
1016 	/*
1017 	 * TOTAL CONCURRENT COPIES
1018 	 */
1019 	put_unaligned_be16(RCR_OP_TOTAL_CONCURR_COPIES, &p[34]);
1020 	/*
1021 	 * MAXIMUM CONCURRENT COPIES
1022 	 */
1023 	p[36] = RCR_OP_MAX_CONCURR_COPIES;
1024 	/*
1025 	 * DATA SEGMENT GRANULARITY (log 2)
1026 	 */
1027 	p[37] = RCR_OP_DATA_SEG_GRAN_LOG2;
1028 	/*
1029 	 * INLINE DATA GRANULARITY log 2)
1030 	 */
1031 	p[38] = RCR_OP_INLINE_DATA_GRAN_LOG2;
1032 	/*
1033 	 * HELD DATA GRANULARITY
1034 	 */
1035 	p[39] = RCR_OP_HELD_DATA_GRAN_LOG2;
1036 	/*
1037 	 * IMPLEMENTED DESCRIPTOR LIST LENGTH
1038 	 */
1039 	p[43] = 0x2;
1040 	/*
1041 	 * List of implemented descriptor type codes (ordered)
1042 	 */
1043 	p[44] = 0x02; /* Copy Block to Block device */
1044 	p[45] = 0xe4; /* Identification descriptor target descriptor */
1045 
1046 	/*
1047 	 * AVAILABLE DATA (n-3)
1048 	 */
1049 	put_unaligned_be32(42, &p[0]);
1050 
1051 	transport_kunmap_data_sg(se_cmd);
1052 	target_complete_cmd(se_cmd, GOOD);
1053 
1054 	return TCM_NO_SENSE;
1055 }
1056 
1057 sense_reason_t target_do_receive_copy_results(struct se_cmd *se_cmd)
1058 {
1059 	unsigned char *cdb = &se_cmd->t_task_cdb[0];
1060 	int sa = (cdb[1] & 0x1f), list_id = cdb[2];
1061 	sense_reason_t rc = TCM_NO_SENSE;
1062 
1063 	pr_debug("Entering target_do_receive_copy_results: SA: 0x%02x, List ID:"
1064 		" 0x%02x, AL: %u\n", sa, list_id, se_cmd->data_length);
1065 
1066 	if (list_id != 0) {
1067 		pr_err("Receive Copy Results with non zero list identifier"
1068 		       " not supported\n");
1069 		return TCM_INVALID_CDB_FIELD;
1070 	}
1071 
1072 	switch (sa) {
1073 	case RCR_SA_OPERATING_PARAMETERS:
1074 		rc = target_rcr_operating_parameters(se_cmd);
1075 		break;
1076 	case RCR_SA_COPY_STATUS:
1077 	case RCR_SA_RECEIVE_DATA:
1078 	case RCR_SA_FAILED_SEGMENT_DETAILS:
1079 	default:
1080 		pr_err("Unsupported SA for receive copy results: 0x%02x\n", sa);
1081 		return TCM_INVALID_CDB_FIELD;
1082 	}
1083 
1084 	return rc;
1085 }
1086