xref: /linux/drivers/target/target_core_xcopy.c (revision 3932b9ca55b0be314a36d3e84faff3e823c081f5)
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_device.c
44  */
45 extern struct mutex g_device_mutex;
46 extern struct list_head g_device_list;
47 /*
48  * From target_core_configfs.c
49  */
50 extern struct configfs_subsystem *target_core_subsystem[];
51 
52 static int target_xcopy_gen_naa_ieee(struct se_device *dev, unsigned char *buf)
53 {
54 	int off = 0;
55 
56 	buf[off++] = (0x6 << 4);
57 	buf[off++] = 0x01;
58 	buf[off++] = 0x40;
59 	buf[off] = (0x5 << 4);
60 
61 	spc_parse_naa_6h_vendor_specific(dev, &buf[off]);
62 	return 0;
63 }
64 
65 static int target_xcopy_locate_se_dev_e4(struct se_cmd *se_cmd, struct xcopy_op *xop,
66 					bool src)
67 {
68 	struct se_device *se_dev;
69 	struct configfs_subsystem *subsys = target_core_subsystem[0];
70 	unsigned char tmp_dev_wwn[XCOPY_NAA_IEEE_REGEX_LEN], *dev_wwn;
71 	int rc;
72 
73 	if (src)
74 		dev_wwn = &xop->dst_tid_wwn[0];
75 	else
76 		dev_wwn = &xop->src_tid_wwn[0];
77 
78 	mutex_lock(&g_device_mutex);
79 	list_for_each_entry(se_dev, &g_device_list, g_dev_node) {
80 
81 		if (!se_dev->dev_attrib.emulate_3pc)
82 			continue;
83 
84 		memset(&tmp_dev_wwn[0], 0, XCOPY_NAA_IEEE_REGEX_LEN);
85 		target_xcopy_gen_naa_ieee(se_dev, &tmp_dev_wwn[0]);
86 
87 		rc = memcmp(&tmp_dev_wwn[0], dev_wwn, XCOPY_NAA_IEEE_REGEX_LEN);
88 		if (rc != 0)
89 			continue;
90 
91 		if (src) {
92 			xop->dst_dev = se_dev;
93 			pr_debug("XCOPY 0xe4: Setting xop->dst_dev: %p from located"
94 				" se_dev\n", xop->dst_dev);
95 		} else {
96 			xop->src_dev = se_dev;
97 			pr_debug("XCOPY 0xe4: Setting xop->src_dev: %p from located"
98 				" se_dev\n", xop->src_dev);
99 		}
100 
101 		rc = configfs_depend_item(subsys,
102 				&se_dev->dev_group.cg_item);
103 		if (rc != 0) {
104 			pr_err("configfs_depend_item attempt failed:"
105 				" %d for se_dev: %p\n", rc, se_dev);
106 			mutex_unlock(&g_device_mutex);
107 			return rc;
108 		}
109 
110 		pr_debug("Called configfs_depend_item for subsys: %p se_dev: %p"
111 			" se_dev->se_dev_group: %p\n", subsys, se_dev,
112 			&se_dev->dev_group);
113 
114 		mutex_unlock(&g_device_mutex);
115 		return 0;
116 	}
117 	mutex_unlock(&g_device_mutex);
118 
119 	pr_err("Unable to locate 0xe4 descriptor for EXTENDED_COPY\n");
120 	return -EINVAL;
121 }
122 
123 static int target_xcopy_parse_tiddesc_e4(struct se_cmd *se_cmd, struct xcopy_op *xop,
124 				unsigned char *p, bool src)
125 {
126 	unsigned char *desc = p;
127 	unsigned short ript;
128 	u8 desig_len;
129 	/*
130 	 * Extract RELATIVE INITIATOR PORT IDENTIFIER
131 	 */
132 	ript = get_unaligned_be16(&desc[2]);
133 	pr_debug("XCOPY 0xe4: RELATIVE INITIATOR PORT IDENTIFIER: %hu\n", ript);
134 	/*
135 	 * Check for supported code set, association, and designator type
136 	 */
137 	if ((desc[4] & 0x0f) != 0x1) {
138 		pr_err("XCOPY 0xe4: code set of non binary type not supported\n");
139 		return -EINVAL;
140 	}
141 	if ((desc[5] & 0x30) != 0x00) {
142 		pr_err("XCOPY 0xe4: association other than LUN not supported\n");
143 		return -EINVAL;
144 	}
145 	if ((desc[5] & 0x0f) != 0x3) {
146 		pr_err("XCOPY 0xe4: designator type unsupported: 0x%02x\n",
147 				(desc[5] & 0x0f));
148 		return -EINVAL;
149 	}
150 	/*
151 	 * Check for matching 16 byte length for NAA IEEE Registered Extended
152 	 * Assigned designator
153 	 */
154 	desig_len = desc[7];
155 	if (desig_len != 16) {
156 		pr_err("XCOPY 0xe4: invalid desig_len: %d\n", (int)desig_len);
157 		return -EINVAL;
158 	}
159 	pr_debug("XCOPY 0xe4: desig_len: %d\n", (int)desig_len);
160 	/*
161 	 * Check for NAA IEEE Registered Extended Assigned header..
162 	 */
163 	if ((desc[8] & 0xf0) != 0x60) {
164 		pr_err("XCOPY 0xe4: Unsupported DESIGNATOR TYPE: 0x%02x\n",
165 					(desc[8] & 0xf0));
166 		return -EINVAL;
167 	}
168 
169 	if (src) {
170 		memcpy(&xop->src_tid_wwn[0], &desc[8], XCOPY_NAA_IEEE_REGEX_LEN);
171 		/*
172 		 * Determine if the source designator matches the local device
173 		 */
174 		if (!memcmp(&xop->local_dev_wwn[0], &xop->src_tid_wwn[0],
175 				XCOPY_NAA_IEEE_REGEX_LEN)) {
176 			xop->op_origin = XCOL_SOURCE_RECV_OP;
177 			xop->src_dev = se_cmd->se_dev;
178 			pr_debug("XCOPY 0xe4: Set xop->src_dev %p from source"
179 					" received xop\n", xop->src_dev);
180 		}
181 	} else {
182 		memcpy(&xop->dst_tid_wwn[0], &desc[8], XCOPY_NAA_IEEE_REGEX_LEN);
183 		/*
184 		 * Determine if the destination designator matches the local device
185 		 */
186 		if (!memcmp(&xop->local_dev_wwn[0], &xop->dst_tid_wwn[0],
187 				XCOPY_NAA_IEEE_REGEX_LEN)) {
188 			xop->op_origin = XCOL_DEST_RECV_OP;
189 			xop->dst_dev = se_cmd->se_dev;
190 			pr_debug("XCOPY 0xe4: Set xop->dst_dev: %p from destination"
191 				" received xop\n", xop->dst_dev);
192 		}
193 	}
194 
195 	return 0;
196 }
197 
198 static int target_xcopy_parse_target_descriptors(struct se_cmd *se_cmd,
199 				struct xcopy_op *xop, unsigned char *p,
200 				unsigned short tdll)
201 {
202 	struct se_device *local_dev = se_cmd->se_dev;
203 	unsigned char *desc = p;
204 	int offset = tdll % XCOPY_TARGET_DESC_LEN, rc, ret = 0;
205 	unsigned short start = 0;
206 	bool src = true;
207 
208 	if (offset != 0) {
209 		pr_err("XCOPY target descriptor list length is not"
210 			" multiple of %d\n", XCOPY_TARGET_DESC_LEN);
211 		return -EINVAL;
212 	}
213 	if (tdll > 64) {
214 		pr_err("XCOPY target descriptor supports a maximum"
215 			" two src/dest descriptors, tdll: %hu too large..\n", tdll);
216 		return -EINVAL;
217 	}
218 	/*
219 	 * Generate an IEEE Registered Extended designator based upon the
220 	 * se_device the XCOPY was received upon..
221 	 */
222 	memset(&xop->local_dev_wwn[0], 0, XCOPY_NAA_IEEE_REGEX_LEN);
223 	target_xcopy_gen_naa_ieee(local_dev, &xop->local_dev_wwn[0]);
224 
225 	while (start < tdll) {
226 		/*
227 		 * Check target descriptor identification with 0xE4 type with
228 		 * use VPD 0x83 WWPN matching ..
229 		 */
230 		switch (desc[0]) {
231 		case 0xe4:
232 			rc = target_xcopy_parse_tiddesc_e4(se_cmd, xop,
233 							&desc[0], src);
234 			if (rc != 0)
235 				goto out;
236 			/*
237 			 * Assume target descriptors are in source -> destination order..
238 			 */
239 			if (src)
240 				src = false;
241 			else
242 				src = true;
243 			start += XCOPY_TARGET_DESC_LEN;
244 			desc += XCOPY_TARGET_DESC_LEN;
245 			ret++;
246 			break;
247 		default:
248 			pr_err("XCOPY unsupported descriptor type code:"
249 					" 0x%02x\n", desc[0]);
250 			goto out;
251 		}
252 	}
253 
254 	if (xop->op_origin == XCOL_SOURCE_RECV_OP)
255 		rc = target_xcopy_locate_se_dev_e4(se_cmd, xop, true);
256 	else
257 		rc = target_xcopy_locate_se_dev_e4(se_cmd, xop, false);
258 
259 	if (rc < 0)
260 		goto out;
261 
262 	pr_debug("XCOPY TGT desc: Source dev: %p NAA IEEE WWN: 0x%16phN\n",
263 		 xop->src_dev, &xop->src_tid_wwn[0]);
264 	pr_debug("XCOPY TGT desc: Dest dev: %p NAA IEEE WWN: 0x%16phN\n",
265 		 xop->dst_dev, &xop->dst_tid_wwn[0]);
266 
267 	return ret;
268 
269 out:
270 	return -EINVAL;
271 }
272 
273 static int target_xcopy_parse_segdesc_02(struct se_cmd *se_cmd, struct xcopy_op *xop,
274 					unsigned char *p)
275 {
276 	unsigned char *desc = p;
277 	int dc = (desc[1] & 0x02);
278 	unsigned short desc_len;
279 
280 	desc_len = get_unaligned_be16(&desc[2]);
281 	if (desc_len != 0x18) {
282 		pr_err("XCOPY segment desc 0x02: Illegal desc_len:"
283 				" %hu\n", desc_len);
284 		return -EINVAL;
285 	}
286 
287 	xop->stdi = get_unaligned_be16(&desc[4]);
288 	xop->dtdi = get_unaligned_be16(&desc[6]);
289 	pr_debug("XCOPY seg desc 0x02: desc_len: %hu stdi: %hu dtdi: %hu, DC: %d\n",
290 		desc_len, xop->stdi, xop->dtdi, dc);
291 
292 	xop->nolb = get_unaligned_be16(&desc[10]);
293 	xop->src_lba = get_unaligned_be64(&desc[12]);
294 	xop->dst_lba = get_unaligned_be64(&desc[20]);
295 	pr_debug("XCOPY seg desc 0x02: nolb: %hu src_lba: %llu dst_lba: %llu\n",
296 		xop->nolb, (unsigned long long)xop->src_lba,
297 		(unsigned long long)xop->dst_lba);
298 
299 	if (dc != 0) {
300 		xop->dbl = (desc[29] & 0xff) << 16;
301 		xop->dbl |= (desc[30] & 0xff) << 8;
302 		xop->dbl |= desc[31] & 0xff;
303 
304 		pr_debug("XCOPY seg desc 0x02: DC=1 w/ dbl: %u\n", xop->dbl);
305 	}
306 	return 0;
307 }
308 
309 static int target_xcopy_parse_segment_descriptors(struct se_cmd *se_cmd,
310 				struct xcopy_op *xop, unsigned char *p,
311 				unsigned int sdll)
312 {
313 	unsigned char *desc = p;
314 	unsigned int start = 0;
315 	int offset = sdll % XCOPY_SEGMENT_DESC_LEN, rc, ret = 0;
316 
317 	if (offset != 0) {
318 		pr_err("XCOPY segment descriptor list length is not"
319 			" multiple of %d\n", XCOPY_SEGMENT_DESC_LEN);
320 		return -EINVAL;
321 	}
322 
323 	while (start < sdll) {
324 		/*
325 		 * Check segment descriptor type code for block -> block
326 		 */
327 		switch (desc[0]) {
328 		case 0x02:
329 			rc = target_xcopy_parse_segdesc_02(se_cmd, xop, desc);
330 			if (rc < 0)
331 				goto out;
332 
333 			ret++;
334 			start += XCOPY_SEGMENT_DESC_LEN;
335 			desc += XCOPY_SEGMENT_DESC_LEN;
336 			break;
337 		default:
338 			pr_err("XCOPY unspported segment descriptor"
339 				"type: 0x%02x\n", desc[0]);
340 			goto out;
341 		}
342 	}
343 
344 	return ret;
345 
346 out:
347 	return -EINVAL;
348 }
349 
350 /*
351  * Start xcopy_pt ops
352  */
353 
354 struct xcopy_pt_cmd {
355 	bool remote_port;
356 	struct se_cmd se_cmd;
357 	struct xcopy_op *xcopy_op;
358 	struct completion xpt_passthrough_sem;
359 	unsigned char sense_buffer[TRANSPORT_SENSE_BUFFER];
360 };
361 
362 static struct se_port xcopy_pt_port;
363 static struct se_portal_group xcopy_pt_tpg;
364 static struct se_session xcopy_pt_sess;
365 static struct se_node_acl xcopy_pt_nacl;
366 
367 static char *xcopy_pt_get_fabric_name(void)
368 {
369         return "xcopy-pt";
370 }
371 
372 static u32 xcopy_pt_get_tag(struct se_cmd *se_cmd)
373 {
374         return 0;
375 }
376 
377 static int xcopy_pt_get_cmd_state(struct se_cmd *se_cmd)
378 {
379         return 0;
380 }
381 
382 static void xcopy_pt_undepend_remotedev(struct xcopy_op *xop)
383 {
384 	struct configfs_subsystem *subsys = target_core_subsystem[0];
385 	struct se_device *remote_dev;
386 
387 	if (xop->op_origin == XCOL_SOURCE_RECV_OP)
388 		remote_dev = xop->dst_dev;
389 	else
390 		remote_dev = xop->src_dev;
391 
392 	pr_debug("Calling configfs_undepend_item for subsys: %p"
393 		  " remote_dev: %p remote_dev->dev_group: %p\n",
394 		  subsys, remote_dev, &remote_dev->dev_group.cg_item);
395 
396 	configfs_undepend_item(subsys, &remote_dev->dev_group.cg_item);
397 }
398 
399 static void xcopy_pt_release_cmd(struct se_cmd *se_cmd)
400 {
401 	struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,
402 				struct xcopy_pt_cmd, se_cmd);
403 
404 	kfree(xpt_cmd);
405 }
406 
407 static int xcopy_pt_check_stop_free(struct se_cmd *se_cmd)
408 {
409 	struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,
410 				struct xcopy_pt_cmd, se_cmd);
411 
412 	complete(&xpt_cmd->xpt_passthrough_sem);
413 	return 0;
414 }
415 
416 static int xcopy_pt_write_pending(struct se_cmd *se_cmd)
417 {
418 	return 0;
419 }
420 
421 static int xcopy_pt_write_pending_status(struct se_cmd *se_cmd)
422 {
423 	return 0;
424 }
425 
426 static int xcopy_pt_queue_data_in(struct se_cmd *se_cmd)
427 {
428 	return 0;
429 }
430 
431 static int xcopy_pt_queue_status(struct se_cmd *se_cmd)
432 {
433 	return 0;
434 }
435 
436 static struct target_core_fabric_ops xcopy_pt_tfo = {
437 	.get_fabric_name	= xcopy_pt_get_fabric_name,
438 	.get_task_tag		= xcopy_pt_get_tag,
439 	.get_cmd_state		= xcopy_pt_get_cmd_state,
440 	.release_cmd		= xcopy_pt_release_cmd,
441 	.check_stop_free	= xcopy_pt_check_stop_free,
442 	.write_pending		= xcopy_pt_write_pending,
443 	.write_pending_status	= xcopy_pt_write_pending_status,
444 	.queue_data_in		= xcopy_pt_queue_data_in,
445 	.queue_status		= xcopy_pt_queue_status,
446 };
447 
448 /*
449  * End xcopy_pt_ops
450  */
451 
452 int target_xcopy_setup_pt(void)
453 {
454 	xcopy_wq = alloc_workqueue("xcopy_wq", WQ_MEM_RECLAIM, 0);
455 	if (!xcopy_wq) {
456 		pr_err("Unable to allocate xcopy_wq\n");
457 		return -ENOMEM;
458 	}
459 
460 	memset(&xcopy_pt_port, 0, sizeof(struct se_port));
461 	INIT_LIST_HEAD(&xcopy_pt_port.sep_alua_list);
462 	INIT_LIST_HEAD(&xcopy_pt_port.sep_list);
463 	mutex_init(&xcopy_pt_port.sep_tg_pt_md_mutex);
464 
465 	memset(&xcopy_pt_tpg, 0, sizeof(struct se_portal_group));
466 	INIT_LIST_HEAD(&xcopy_pt_tpg.se_tpg_node);
467 	INIT_LIST_HEAD(&xcopy_pt_tpg.acl_node_list);
468 	INIT_LIST_HEAD(&xcopy_pt_tpg.tpg_sess_list);
469 
470 	xcopy_pt_port.sep_tpg = &xcopy_pt_tpg;
471 	xcopy_pt_tpg.se_tpg_tfo = &xcopy_pt_tfo;
472 
473 	memset(&xcopy_pt_nacl, 0, sizeof(struct se_node_acl));
474 	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_list);
475 	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_sess_list);
476 	memset(&xcopy_pt_sess, 0, sizeof(struct se_session));
477 	INIT_LIST_HEAD(&xcopy_pt_sess.sess_list);
478 	INIT_LIST_HEAD(&xcopy_pt_sess.sess_acl_list);
479 
480 	xcopy_pt_nacl.se_tpg = &xcopy_pt_tpg;
481 	xcopy_pt_nacl.nacl_sess = &xcopy_pt_sess;
482 
483 	xcopy_pt_sess.se_tpg = &xcopy_pt_tpg;
484 	xcopy_pt_sess.se_node_acl = &xcopy_pt_nacl;
485 
486 	return 0;
487 }
488 
489 void target_xcopy_release_pt(void)
490 {
491 	if (xcopy_wq)
492 		destroy_workqueue(xcopy_wq);
493 }
494 
495 static void target_xcopy_setup_pt_port(
496 	struct xcopy_pt_cmd *xpt_cmd,
497 	struct xcopy_op *xop,
498 	bool remote_port)
499 {
500 	struct se_cmd *ec_cmd = xop->xop_se_cmd;
501 	struct se_cmd *pt_cmd = &xpt_cmd->se_cmd;
502 
503 	if (xop->op_origin == XCOL_SOURCE_RECV_OP) {
504 		/*
505 		 * Honor destination port reservations for X-COPY PUSH emulation
506 		 * when CDB is received on local source port, and READs blocks to
507 		 * WRITE on remote destination port.
508 		 */
509 		if (remote_port) {
510 			xpt_cmd->remote_port = remote_port;
511 			pt_cmd->se_lun->lun_sep = &xcopy_pt_port;
512 			pr_debug("Setup emulated remote DEST xcopy_pt_port: %p to"
513 				" cmd->se_lun->lun_sep for X-COPY data PUSH\n",
514 				pt_cmd->se_lun->lun_sep);
515 		} else {
516 			pt_cmd->se_lun = ec_cmd->se_lun;
517 			pt_cmd->se_dev = ec_cmd->se_dev;
518 
519 			pr_debug("Honoring local SRC port from ec_cmd->se_dev:"
520 				" %p\n", pt_cmd->se_dev);
521 			pt_cmd->se_lun = ec_cmd->se_lun;
522 			pr_debug("Honoring local SRC port from ec_cmd->se_lun: %p\n",
523 				pt_cmd->se_lun);
524 		}
525 	} else {
526 		/*
527 		 * Honor source port reservation for X-COPY PULL emulation
528 		 * when CDB is received on local desintation port, and READs
529 		 * blocks from the remote source port to WRITE on local
530 		 * destination port.
531 		 */
532 		if (remote_port) {
533 			xpt_cmd->remote_port = remote_port;
534 			pt_cmd->se_lun->lun_sep = &xcopy_pt_port;
535 			pr_debug("Setup emulated remote SRC xcopy_pt_port: %p to"
536 				" cmd->se_lun->lun_sep for X-COPY data PULL\n",
537 				pt_cmd->se_lun->lun_sep);
538 		} else {
539 			pt_cmd->se_lun = ec_cmd->se_lun;
540 			pt_cmd->se_dev = ec_cmd->se_dev;
541 
542 			pr_debug("Honoring local DST port from ec_cmd->se_dev:"
543 				" %p\n", pt_cmd->se_dev);
544 			pt_cmd->se_lun = ec_cmd->se_lun;
545 			pr_debug("Honoring local DST port from ec_cmd->se_lun: %p\n",
546 				pt_cmd->se_lun);
547 		}
548 	}
549 }
550 
551 static int target_xcopy_init_pt_lun(
552 	struct xcopy_pt_cmd *xpt_cmd,
553 	struct xcopy_op *xop,
554 	struct se_device *se_dev,
555 	struct se_cmd *pt_cmd,
556 	bool remote_port)
557 {
558 	/*
559 	 * Don't allocate + init an pt_cmd->se_lun if honoring local port for
560 	 * reservations.  The pt_cmd->se_lun pointer will be setup from within
561 	 * target_xcopy_setup_pt_port()
562 	 */
563 	if (!remote_port) {
564 		pt_cmd->se_cmd_flags |= SCF_SE_LUN_CMD | SCF_CMD_XCOPY_PASSTHROUGH;
565 		return 0;
566 	}
567 
568 	pt_cmd->se_lun = &se_dev->xcopy_lun;
569 	pt_cmd->se_dev = se_dev;
570 
571 	pr_debug("Setup emulated se_dev: %p from se_dev\n", pt_cmd->se_dev);
572 	pt_cmd->se_cmd_flags |= SCF_SE_LUN_CMD | SCF_CMD_XCOPY_PASSTHROUGH;
573 
574 	pr_debug("Setup emulated se_dev: %p to pt_cmd->se_lun->lun_se_dev\n",
575 		pt_cmd->se_lun->lun_se_dev);
576 
577 	return 0;
578 }
579 
580 static int target_xcopy_setup_pt_cmd(
581 	struct xcopy_pt_cmd *xpt_cmd,
582 	struct xcopy_op *xop,
583 	struct se_device *se_dev,
584 	unsigned char *cdb,
585 	bool remote_port,
586 	bool alloc_mem)
587 {
588 	struct se_cmd *cmd = &xpt_cmd->se_cmd;
589 	sense_reason_t sense_rc;
590 	int ret = 0, rc;
591 	/*
592 	 * Setup LUN+port to honor reservations based upon xop->op_origin for
593 	 * X-COPY PUSH or X-COPY PULL based upon where the CDB was received.
594 	 */
595 	rc = target_xcopy_init_pt_lun(xpt_cmd, xop, se_dev, cmd, remote_port);
596 	if (rc < 0) {
597 		ret = rc;
598 		goto out;
599 	}
600 	xpt_cmd->xcopy_op = xop;
601 	target_xcopy_setup_pt_port(xpt_cmd, xop, remote_port);
602 
603 	sense_rc = target_setup_cmd_from_cdb(cmd, cdb);
604 	if (sense_rc) {
605 		ret = -EINVAL;
606 		goto out;
607 	}
608 
609 	if (alloc_mem) {
610 		rc = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
611 				      cmd->data_length, false);
612 		if (rc < 0) {
613 			ret = rc;
614 			goto out;
615 		}
616 		/*
617 		 * Set this bit so that transport_free_pages() allows the
618 		 * caller to release SGLs + physical memory allocated by
619 		 * transport_generic_get_mem()..
620 		 */
621 		cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
622 	} else {
623 		/*
624 		 * Here the previously allocated SGLs for the internal READ
625 		 * are mapped zero-copy to the internal WRITE.
626 		 */
627 		sense_rc = transport_generic_map_mem_to_cmd(cmd,
628 					xop->xop_data_sg, xop->xop_data_nents,
629 					NULL, 0);
630 		if (sense_rc) {
631 			ret = -EINVAL;
632 			goto out;
633 		}
634 
635 		pr_debug("Setup PASSTHROUGH_NOALLOC t_data_sg: %p t_data_nents:"
636 			 " %u\n", cmd->t_data_sg, cmd->t_data_nents);
637 	}
638 
639 	return 0;
640 
641 out:
642 	return ret;
643 }
644 
645 static int target_xcopy_issue_pt_cmd(struct xcopy_pt_cmd *xpt_cmd)
646 {
647 	struct se_cmd *se_cmd = &xpt_cmd->se_cmd;
648 	sense_reason_t sense_rc;
649 
650 	sense_rc = transport_generic_new_cmd(se_cmd);
651 	if (sense_rc)
652 		return -EINVAL;
653 
654 	if (se_cmd->data_direction == DMA_TO_DEVICE)
655 		target_execute_cmd(se_cmd);
656 
657 	wait_for_completion_interruptible(&xpt_cmd->xpt_passthrough_sem);
658 
659 	pr_debug("target_xcopy_issue_pt_cmd(): SCSI status: 0x%02x\n",
660 			se_cmd->scsi_status);
661 
662 	return (se_cmd->scsi_status) ? -EINVAL : 0;
663 }
664 
665 static int target_xcopy_read_source(
666 	struct se_cmd *ec_cmd,
667 	struct xcopy_op *xop,
668 	struct se_device *src_dev,
669 	sector_t src_lba,
670 	u32 src_sectors)
671 {
672 	struct xcopy_pt_cmd *xpt_cmd;
673 	struct se_cmd *se_cmd;
674 	u32 length = (src_sectors * src_dev->dev_attrib.block_size);
675 	int rc;
676 	unsigned char cdb[16];
677 	bool remote_port = (xop->op_origin == XCOL_DEST_RECV_OP);
678 
679 	xpt_cmd = kzalloc(sizeof(struct xcopy_pt_cmd), GFP_KERNEL);
680 	if (!xpt_cmd) {
681 		pr_err("Unable to allocate xcopy_pt_cmd\n");
682 		return -ENOMEM;
683 	}
684 	init_completion(&xpt_cmd->xpt_passthrough_sem);
685 	se_cmd = &xpt_cmd->se_cmd;
686 
687 	memset(&cdb[0], 0, 16);
688 	cdb[0] = READ_16;
689 	put_unaligned_be64(src_lba, &cdb[2]);
690 	put_unaligned_be32(src_sectors, &cdb[10]);
691 	pr_debug("XCOPY: Built READ_16: LBA: %llu Sectors: %u Length: %u\n",
692 		(unsigned long long)src_lba, src_sectors, length);
693 
694 	transport_init_se_cmd(se_cmd, &xcopy_pt_tfo, NULL, length,
695 			      DMA_FROM_DEVICE, 0, &xpt_cmd->sense_buffer[0]);
696 	xop->src_pt_cmd = xpt_cmd;
697 
698 	rc = target_xcopy_setup_pt_cmd(xpt_cmd, xop, src_dev, &cdb[0],
699 				remote_port, true);
700 	if (rc < 0) {
701 		transport_generic_free_cmd(se_cmd, 0);
702 		return rc;
703 	}
704 
705 	xop->xop_data_sg = se_cmd->t_data_sg;
706 	xop->xop_data_nents = se_cmd->t_data_nents;
707 	pr_debug("XCOPY-READ: Saved xop->xop_data_sg: %p, num: %u for READ"
708 		" memory\n", xop->xop_data_sg, xop->xop_data_nents);
709 
710 	rc = target_xcopy_issue_pt_cmd(xpt_cmd);
711 	if (rc < 0) {
712 		transport_generic_free_cmd(se_cmd, 0);
713 		return rc;
714 	}
715 	/*
716 	 * Clear off the allocated t_data_sg, that has been saved for
717 	 * zero-copy WRITE submission reuse in struct xcopy_op..
718 	 */
719 	se_cmd->t_data_sg = NULL;
720 	se_cmd->t_data_nents = 0;
721 
722 	return 0;
723 }
724 
725 static int target_xcopy_write_destination(
726 	struct se_cmd *ec_cmd,
727 	struct xcopy_op *xop,
728 	struct se_device *dst_dev,
729 	sector_t dst_lba,
730 	u32 dst_sectors)
731 {
732 	struct xcopy_pt_cmd *xpt_cmd;
733 	struct se_cmd *se_cmd;
734 	u32 length = (dst_sectors * dst_dev->dev_attrib.block_size);
735 	int rc;
736 	unsigned char cdb[16];
737 	bool remote_port = (xop->op_origin == XCOL_SOURCE_RECV_OP);
738 
739 	xpt_cmd = kzalloc(sizeof(struct xcopy_pt_cmd), GFP_KERNEL);
740 	if (!xpt_cmd) {
741 		pr_err("Unable to allocate xcopy_pt_cmd\n");
742 		return -ENOMEM;
743 	}
744 	init_completion(&xpt_cmd->xpt_passthrough_sem);
745 	se_cmd = &xpt_cmd->se_cmd;
746 
747 	memset(&cdb[0], 0, 16);
748 	cdb[0] = WRITE_16;
749 	put_unaligned_be64(dst_lba, &cdb[2]);
750 	put_unaligned_be32(dst_sectors, &cdb[10]);
751 	pr_debug("XCOPY: Built WRITE_16: LBA: %llu Sectors: %u Length: %u\n",
752 		(unsigned long long)dst_lba, dst_sectors, length);
753 
754 	transport_init_se_cmd(se_cmd, &xcopy_pt_tfo, NULL, length,
755 			      DMA_TO_DEVICE, 0, &xpt_cmd->sense_buffer[0]);
756 	xop->dst_pt_cmd = xpt_cmd;
757 
758 	rc = target_xcopy_setup_pt_cmd(xpt_cmd, xop, dst_dev, &cdb[0],
759 				remote_port, false);
760 	if (rc < 0) {
761 		struct se_cmd *src_cmd = &xop->src_pt_cmd->se_cmd;
762 		/*
763 		 * If the failure happened before the t_mem_list hand-off in
764 		 * target_xcopy_setup_pt_cmd(), Reset memory + clear flag so that
765 		 * core releases this memory on error during X-COPY WRITE I/O.
766 		 */
767 		src_cmd->se_cmd_flags &= ~SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
768 		src_cmd->t_data_sg = xop->xop_data_sg;
769 		src_cmd->t_data_nents = xop->xop_data_nents;
770 
771 		transport_generic_free_cmd(se_cmd, 0);
772 		return rc;
773 	}
774 
775 	rc = target_xcopy_issue_pt_cmd(xpt_cmd);
776 	if (rc < 0) {
777 		se_cmd->se_cmd_flags &= ~SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
778 		transport_generic_free_cmd(se_cmd, 0);
779 		return rc;
780 	}
781 
782 	return 0;
783 }
784 
785 static void target_xcopy_do_work(struct work_struct *work)
786 {
787 	struct xcopy_op *xop = container_of(work, struct xcopy_op, xop_work);
788 	struct se_device *src_dev = xop->src_dev, *dst_dev = xop->dst_dev;
789 	struct se_cmd *ec_cmd = xop->xop_se_cmd;
790 	sector_t src_lba = xop->src_lba, dst_lba = xop->dst_lba, end_lba;
791 	unsigned int max_sectors;
792 	int rc;
793 	unsigned short nolb = xop->nolb, cur_nolb, max_nolb, copied_nolb = 0;
794 
795 	end_lba = src_lba + nolb;
796 	/*
797 	 * Break up XCOPY I/O into hw_max_sectors sized I/O based on the
798 	 * smallest max_sectors between src_dev + dev_dev, or
799 	 */
800 	max_sectors = min(src_dev->dev_attrib.hw_max_sectors,
801 			  dst_dev->dev_attrib.hw_max_sectors);
802 	max_sectors = min_t(u32, max_sectors, XCOPY_MAX_SECTORS);
803 
804 	max_nolb = min_t(u16, max_sectors, ((u16)(~0U)));
805 
806 	pr_debug("target_xcopy_do_work: nolb: %hu, max_nolb: %hu end_lba: %llu\n",
807 			nolb, max_nolb, (unsigned long long)end_lba);
808 	pr_debug("target_xcopy_do_work: Starting src_lba: %llu, dst_lba: %llu\n",
809 			(unsigned long long)src_lba, (unsigned long long)dst_lba);
810 
811 	while (src_lba < end_lba) {
812 		cur_nolb = min(nolb, max_nolb);
813 
814 		pr_debug("target_xcopy_do_work: Calling read src_dev: %p src_lba: %llu,"
815 			" cur_nolb: %hu\n", src_dev, (unsigned long long)src_lba, cur_nolb);
816 
817 		rc = target_xcopy_read_source(ec_cmd, xop, src_dev, src_lba, cur_nolb);
818 		if (rc < 0)
819 			goto out;
820 
821 		src_lba += cur_nolb;
822 		pr_debug("target_xcopy_do_work: Incremented READ src_lba to %llu\n",
823 				(unsigned long long)src_lba);
824 
825 		pr_debug("target_xcopy_do_work: Calling write dst_dev: %p dst_lba: %llu,"
826 			" cur_nolb: %hu\n", dst_dev, (unsigned long long)dst_lba, cur_nolb);
827 
828 		rc = target_xcopy_write_destination(ec_cmd, xop, dst_dev,
829 						dst_lba, cur_nolb);
830 		if (rc < 0) {
831 			transport_generic_free_cmd(&xop->src_pt_cmd->se_cmd, 0);
832 			goto out;
833 		}
834 
835 		dst_lba += cur_nolb;
836 		pr_debug("target_xcopy_do_work: Incremented WRITE dst_lba to %llu\n",
837 				(unsigned long long)dst_lba);
838 
839 		copied_nolb += cur_nolb;
840 		nolb -= cur_nolb;
841 
842 		transport_generic_free_cmd(&xop->src_pt_cmd->se_cmd, 0);
843 		xop->dst_pt_cmd->se_cmd.se_cmd_flags &= ~SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
844 
845 		transport_generic_free_cmd(&xop->dst_pt_cmd->se_cmd, 0);
846 	}
847 
848 	xcopy_pt_undepend_remotedev(xop);
849 	kfree(xop);
850 
851 	pr_debug("target_xcopy_do_work: Final src_lba: %llu, dst_lba: %llu\n",
852 		(unsigned long long)src_lba, (unsigned long long)dst_lba);
853 	pr_debug("target_xcopy_do_work: Blocks copied: %hu, Bytes Copied: %u\n",
854 		copied_nolb, copied_nolb * dst_dev->dev_attrib.block_size);
855 
856 	pr_debug("target_xcopy_do_work: Setting X-COPY GOOD status -> sending response\n");
857 	target_complete_cmd(ec_cmd, SAM_STAT_GOOD);
858 	return;
859 
860 out:
861 	xcopy_pt_undepend_remotedev(xop);
862 	kfree(xop);
863 
864 	pr_warn("target_xcopy_do_work: Setting X-COPY CHECK_CONDITION -> sending response\n");
865 	ec_cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
866 	target_complete_cmd(ec_cmd, SAM_STAT_CHECK_CONDITION);
867 }
868 
869 sense_reason_t target_do_xcopy(struct se_cmd *se_cmd)
870 {
871 	struct se_device *dev = se_cmd->se_dev;
872 	struct xcopy_op *xop = NULL;
873 	unsigned char *p = NULL, *seg_desc;
874 	unsigned int list_id, list_id_usage, sdll, inline_dl, sa;
875 	sense_reason_t ret = TCM_INVALID_PARAMETER_LIST;
876 	int rc;
877 	unsigned short tdll;
878 
879 	if (!dev->dev_attrib.emulate_3pc) {
880 		pr_err("EXTENDED_COPY operation explicitly disabled\n");
881 		return TCM_UNSUPPORTED_SCSI_OPCODE;
882 	}
883 
884 	sa = se_cmd->t_task_cdb[1] & 0x1f;
885 	if (sa != 0x00) {
886 		pr_err("EXTENDED_COPY(LID4) not supported\n");
887 		return TCM_UNSUPPORTED_SCSI_OPCODE;
888 	}
889 
890 	xop = kzalloc(sizeof(struct xcopy_op), GFP_KERNEL);
891 	if (!xop) {
892 		pr_err("Unable to allocate xcopy_op\n");
893 		return TCM_OUT_OF_RESOURCES;
894 	}
895 	xop->xop_se_cmd = se_cmd;
896 
897 	p = transport_kmap_data_sg(se_cmd);
898 	if (!p) {
899 		pr_err("transport_kmap_data_sg() failed in target_do_xcopy\n");
900 		kfree(xop);
901 		return TCM_OUT_OF_RESOURCES;
902 	}
903 
904 	list_id = p[0];
905 	list_id_usage = (p[1] & 0x18) >> 3;
906 
907 	/*
908 	 * Determine TARGET DESCRIPTOR LIST LENGTH + SEGMENT DESCRIPTOR LIST LENGTH
909 	 */
910 	tdll = get_unaligned_be16(&p[2]);
911 	sdll = get_unaligned_be32(&p[8]);
912 
913 	inline_dl = get_unaligned_be32(&p[12]);
914 	if (inline_dl != 0) {
915 		pr_err("XCOPY with non zero inline data length\n");
916 		goto out;
917 	}
918 
919 	pr_debug("Processing XCOPY with list_id: 0x%02x list_id_usage: 0x%02x"
920 		" tdll: %hu sdll: %u inline_dl: %u\n", list_id, list_id_usage,
921 		tdll, sdll, inline_dl);
922 
923 	rc = target_xcopy_parse_target_descriptors(se_cmd, xop, &p[16], tdll);
924 	if (rc <= 0)
925 		goto out;
926 
927 	if (xop->src_dev->dev_attrib.block_size !=
928 	    xop->dst_dev->dev_attrib.block_size) {
929 		pr_err("XCOPY: Non matching src_dev block_size: %u + dst_dev"
930 		       " block_size: %u currently unsupported\n",
931 			xop->src_dev->dev_attrib.block_size,
932 			xop->dst_dev->dev_attrib.block_size);
933 		xcopy_pt_undepend_remotedev(xop);
934 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
935 		goto out;
936 	}
937 
938 	pr_debug("XCOPY: Processed %d target descriptors, length: %u\n", rc,
939 				rc * XCOPY_TARGET_DESC_LEN);
940 	seg_desc = &p[16];
941 	seg_desc += (rc * XCOPY_TARGET_DESC_LEN);
942 
943 	rc = target_xcopy_parse_segment_descriptors(se_cmd, xop, seg_desc, sdll);
944 	if (rc <= 0) {
945 		xcopy_pt_undepend_remotedev(xop);
946 		goto out;
947 	}
948 	transport_kunmap_data_sg(se_cmd);
949 
950 	pr_debug("XCOPY: Processed %d segment descriptors, length: %u\n", rc,
951 				rc * XCOPY_SEGMENT_DESC_LEN);
952 	INIT_WORK(&xop->xop_work, target_xcopy_do_work);
953 	queue_work(xcopy_wq, &xop->xop_work);
954 	return TCM_NO_SENSE;
955 
956 out:
957 	if (p)
958 		transport_kunmap_data_sg(se_cmd);
959 	kfree(xop);
960 	return ret;
961 }
962 
963 static sense_reason_t target_rcr_operating_parameters(struct se_cmd *se_cmd)
964 {
965 	unsigned char *p;
966 
967 	p = transport_kmap_data_sg(se_cmd);
968 	if (!p) {
969 		pr_err("transport_kmap_data_sg failed in"
970 		       " target_rcr_operating_parameters\n");
971 		return TCM_OUT_OF_RESOURCES;
972 	}
973 
974 	if (se_cmd->data_length < 54) {
975 		pr_err("Receive Copy Results Op Parameters length"
976 		       " too small: %u\n", se_cmd->data_length);
977 		transport_kunmap_data_sg(se_cmd);
978 		return TCM_INVALID_CDB_FIELD;
979 	}
980 	/*
981 	 * Set SNLID=1 (Supports no List ID)
982 	 */
983 	p[4] = 0x1;
984 	/*
985 	 * MAXIMUM TARGET DESCRIPTOR COUNT
986 	 */
987 	put_unaligned_be16(RCR_OP_MAX_TARGET_DESC_COUNT, &p[8]);
988 	/*
989 	 * MAXIMUM SEGMENT DESCRIPTOR COUNT
990 	 */
991 	put_unaligned_be16(RCR_OP_MAX_SG_DESC_COUNT, &p[10]);
992 	/*
993 	 * MAXIMUM DESCRIPTOR LIST LENGTH
994 	 */
995 	put_unaligned_be32(RCR_OP_MAX_DESC_LIST_LEN, &p[12]);
996 	/*
997 	 * MAXIMUM SEGMENT LENGTH
998 	 */
999 	put_unaligned_be32(RCR_OP_MAX_SEGMENT_LEN, &p[16]);
1000 	/*
1001 	 * MAXIMUM INLINE DATA LENGTH for SA 0x04 (NOT SUPPORTED)
1002 	 */
1003 	put_unaligned_be32(0x0, &p[20]);
1004 	/*
1005 	 * HELD DATA LIMIT
1006 	 */
1007 	put_unaligned_be32(0x0, &p[24]);
1008 	/*
1009 	 * MAXIMUM STREAM DEVICE TRANSFER SIZE
1010 	 */
1011 	put_unaligned_be32(0x0, &p[28]);
1012 	/*
1013 	 * TOTAL CONCURRENT COPIES
1014 	 */
1015 	put_unaligned_be16(RCR_OP_TOTAL_CONCURR_COPIES, &p[34]);
1016 	/*
1017 	 * MAXIMUM CONCURRENT COPIES
1018 	 */
1019 	p[36] = RCR_OP_MAX_CONCURR_COPIES;
1020 	/*
1021 	 * DATA SEGMENT GRANULARITY (log 2)
1022 	 */
1023 	p[37] = RCR_OP_DATA_SEG_GRAN_LOG2;
1024 	/*
1025 	 * INLINE DATA GRANULARITY log 2)
1026 	 */
1027 	p[38] = RCR_OP_INLINE_DATA_GRAN_LOG2;
1028 	/*
1029 	 * HELD DATA GRANULARITY
1030 	 */
1031 	p[39] = RCR_OP_HELD_DATA_GRAN_LOG2;
1032 	/*
1033 	 * IMPLEMENTED DESCRIPTOR LIST LENGTH
1034 	 */
1035 	p[43] = 0x2;
1036 	/*
1037 	 * List of implemented descriptor type codes (ordered)
1038 	 */
1039 	p[44] = 0x02; /* Copy Block to Block device */
1040 	p[45] = 0xe4; /* Identification descriptor target descriptor */
1041 
1042 	/*
1043 	 * AVAILABLE DATA (n-3)
1044 	 */
1045 	put_unaligned_be32(42, &p[0]);
1046 
1047 	transport_kunmap_data_sg(se_cmd);
1048 	target_complete_cmd(se_cmd, GOOD);
1049 
1050 	return TCM_NO_SENSE;
1051 }
1052 
1053 sense_reason_t target_do_receive_copy_results(struct se_cmd *se_cmd)
1054 {
1055 	unsigned char *cdb = &se_cmd->t_task_cdb[0];
1056 	int sa = (cdb[1] & 0x1f), list_id = cdb[2];
1057 	sense_reason_t rc = TCM_NO_SENSE;
1058 
1059 	pr_debug("Entering target_do_receive_copy_results: SA: 0x%02x, List ID:"
1060 		" 0x%02x, AL: %u\n", sa, list_id, se_cmd->data_length);
1061 
1062 	if (list_id != 0) {
1063 		pr_err("Receive Copy Results with non zero list identifier"
1064 		       " not supported\n");
1065 		return TCM_INVALID_CDB_FIELD;
1066 	}
1067 
1068 	switch (sa) {
1069 	case RCR_SA_OPERATING_PARAMETERS:
1070 		rc = target_rcr_operating_parameters(se_cmd);
1071 		break;
1072 	case RCR_SA_COPY_STATUS:
1073 	case RCR_SA_RECEIVE_DATA:
1074 	case RCR_SA_FAILED_SEGMENT_DETAILS:
1075 	default:
1076 		pr_err("Unsupported SA for receive copy results: 0x%02x\n", sa);
1077 		return TCM_INVALID_CDB_FIELD;
1078 	}
1079 
1080 	return rc;
1081 }
1082