1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*******************************************************************************
3  * Filename: target_core_xcopy.c
4  *
5  * This file contains support for SPC-4 Extended-Copy offload with generic
6  * TCM backends.
7  *
8  * Copyright (c) 2011-2013 Datera, Inc. All rights reserved.
9  *
10  * Author:
11  * Nicholas A. Bellinger <nab@daterainc.com>
12  *
13  ******************************************************************************/
14 
15 #include <linux/slab.h>
16 #include <linux/spinlock.h>
17 #include <linux/list.h>
18 #include <linux/configfs.h>
19 #include <linux/ratelimit.h>
20 #include <scsi/scsi_proto.h>
21 #include <asm/unaligned.h>
22 
23 #include <target/target_core_base.h>
24 #include <target/target_core_backend.h>
25 #include <target/target_core_fabric.h>
26 
27 #include "target_core_internal.h"
28 #include "target_core_pr.h"
29 #include "target_core_ua.h"
30 #include "target_core_xcopy.h"
31 
32 static struct workqueue_struct *xcopy_wq = NULL;
33 
34 static sense_reason_t target_parse_xcopy_cmd(struct xcopy_op *xop);
35 
36 static int target_xcopy_gen_naa_ieee(struct se_device *dev, unsigned char *buf)
37 {
38 	int off = 0;
39 
40 	buf[off++] = (0x6 << 4);
41 	buf[off++] = 0x01;
42 	buf[off++] = 0x40;
43 	buf[off] = (0x5 << 4);
44 
45 	spc_parse_naa_6h_vendor_specific(dev, &buf[off]);
46 	return 0;
47 }
48 
49 struct xcopy_dev_search_info {
50 	const unsigned char *dev_wwn;
51 	struct se_device *found_dev;
52 };
53 
54 static int target_xcopy_locate_se_dev_e4_iter(struct se_device *se_dev,
55 					      void *data)
56 {
57 	struct xcopy_dev_search_info *info = data;
58 	unsigned char tmp_dev_wwn[XCOPY_NAA_IEEE_REGEX_LEN];
59 	int rc;
60 
61 	if (!se_dev->dev_attrib.emulate_3pc)
62 		return 0;
63 
64 	memset(&tmp_dev_wwn[0], 0, XCOPY_NAA_IEEE_REGEX_LEN);
65 	target_xcopy_gen_naa_ieee(se_dev, &tmp_dev_wwn[0]);
66 
67 	rc = memcmp(&tmp_dev_wwn[0], info->dev_wwn, XCOPY_NAA_IEEE_REGEX_LEN);
68 	if (rc != 0)
69 		return 0;
70 
71 	info->found_dev = se_dev;
72 	pr_debug("XCOPY 0xe4: located se_dev: %p\n", se_dev);
73 
74 	rc = target_depend_item(&se_dev->dev_group.cg_item);
75 	if (rc != 0) {
76 		pr_err("configfs_depend_item attempt failed: %d for se_dev: %p\n",
77 		       rc, se_dev);
78 		return rc;
79 	}
80 
81 	pr_debug("Called configfs_depend_item for se_dev: %p se_dev->se_dev_group: %p\n",
82 		 se_dev, &se_dev->dev_group);
83 	return 1;
84 }
85 
86 static int target_xcopy_locate_se_dev_e4(const unsigned char *dev_wwn,
87 					struct se_device **found_dev)
88 {
89 	struct xcopy_dev_search_info info;
90 	int ret;
91 
92 	memset(&info, 0, sizeof(info));
93 	info.dev_wwn = dev_wwn;
94 
95 	ret = target_for_each_device(target_xcopy_locate_se_dev_e4_iter, &info);
96 	if (ret == 1) {
97 		*found_dev = info.found_dev;
98 		return 0;
99 	} else {
100 		pr_debug_ratelimited("Unable to locate 0xe4 descriptor for EXTENDED_COPY\n");
101 		return -EINVAL;
102 	}
103 }
104 
105 static int target_xcopy_parse_tiddesc_e4(struct se_cmd *se_cmd, struct xcopy_op *xop,
106 				unsigned char *p, unsigned short cscd_index)
107 {
108 	unsigned char *desc = p;
109 	unsigned short ript;
110 	u8 desig_len;
111 	/*
112 	 * Extract RELATIVE INITIATOR PORT IDENTIFIER
113 	 */
114 	ript = get_unaligned_be16(&desc[2]);
115 	pr_debug("XCOPY 0xe4: RELATIVE INITIATOR PORT IDENTIFIER: %hu\n", ript);
116 	/*
117 	 * Check for supported code set, association, and designator type
118 	 */
119 	if ((desc[4] & 0x0f) != 0x1) {
120 		pr_err("XCOPY 0xe4: code set of non binary type not supported\n");
121 		return -EINVAL;
122 	}
123 	if ((desc[5] & 0x30) != 0x00) {
124 		pr_err("XCOPY 0xe4: association other than LUN not supported\n");
125 		return -EINVAL;
126 	}
127 	if ((desc[5] & 0x0f) != 0x3) {
128 		pr_err("XCOPY 0xe4: designator type unsupported: 0x%02x\n",
129 				(desc[5] & 0x0f));
130 		return -EINVAL;
131 	}
132 	/*
133 	 * Check for matching 16 byte length for NAA IEEE Registered Extended
134 	 * Assigned designator
135 	 */
136 	desig_len = desc[7];
137 	if (desig_len != 16) {
138 		pr_err("XCOPY 0xe4: invalid desig_len: %d\n", (int)desig_len);
139 		return -EINVAL;
140 	}
141 	pr_debug("XCOPY 0xe4: desig_len: %d\n", (int)desig_len);
142 	/*
143 	 * Check for NAA IEEE Registered Extended Assigned header..
144 	 */
145 	if ((desc[8] & 0xf0) != 0x60) {
146 		pr_err("XCOPY 0xe4: Unsupported DESIGNATOR TYPE: 0x%02x\n",
147 					(desc[8] & 0xf0));
148 		return -EINVAL;
149 	}
150 
151 	if (cscd_index != xop->stdi && cscd_index != xop->dtdi) {
152 		pr_debug("XCOPY 0xe4: ignoring CSCD entry %d - neither src nor "
153 			 "dest\n", cscd_index);
154 		return 0;
155 	}
156 
157 	if (cscd_index == xop->stdi) {
158 		memcpy(&xop->src_tid_wwn[0], &desc[8], XCOPY_NAA_IEEE_REGEX_LEN);
159 		/*
160 		 * Determine if the source designator matches the local device
161 		 */
162 		if (!memcmp(&xop->local_dev_wwn[0], &xop->src_tid_wwn[0],
163 				XCOPY_NAA_IEEE_REGEX_LEN)) {
164 			xop->op_origin = XCOL_SOURCE_RECV_OP;
165 			xop->src_dev = se_cmd->se_dev;
166 			pr_debug("XCOPY 0xe4: Set xop->src_dev %p from source"
167 					" received xop\n", xop->src_dev);
168 		}
169 	}
170 
171 	if (cscd_index == xop->dtdi) {
172 		memcpy(&xop->dst_tid_wwn[0], &desc[8], XCOPY_NAA_IEEE_REGEX_LEN);
173 		/*
174 		 * Determine if the destination designator matches the local
175 		 * device. If @cscd_index corresponds to both source (stdi) and
176 		 * destination (dtdi), or dtdi comes after stdi, then
177 		 * XCOL_DEST_RECV_OP wins.
178 		 */
179 		if (!memcmp(&xop->local_dev_wwn[0], &xop->dst_tid_wwn[0],
180 				XCOPY_NAA_IEEE_REGEX_LEN)) {
181 			xop->op_origin = XCOL_DEST_RECV_OP;
182 			xop->dst_dev = se_cmd->se_dev;
183 			pr_debug("XCOPY 0xe4: Set xop->dst_dev: %p from destination"
184 				" received xop\n", xop->dst_dev);
185 		}
186 	}
187 
188 	return 0;
189 }
190 
191 static int target_xcopy_parse_target_descriptors(struct se_cmd *se_cmd,
192 				struct xcopy_op *xop, unsigned char *p,
193 				unsigned short tdll, sense_reason_t *sense_ret)
194 {
195 	struct se_device *local_dev = se_cmd->se_dev;
196 	unsigned char *desc = p;
197 	int offset = tdll % XCOPY_TARGET_DESC_LEN, rc;
198 	unsigned short cscd_index = 0;
199 	unsigned short start = 0;
200 
201 	*sense_ret = TCM_INVALID_PARAMETER_LIST;
202 
203 	if (offset != 0) {
204 		pr_err("XCOPY target descriptor list length is not"
205 			" multiple of %d\n", XCOPY_TARGET_DESC_LEN);
206 		*sense_ret = TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE;
207 		return -EINVAL;
208 	}
209 	if (tdll > RCR_OP_MAX_TARGET_DESC_COUNT * XCOPY_TARGET_DESC_LEN) {
210 		pr_err("XCOPY target descriptor supports a maximum"
211 			" two src/dest descriptors, tdll: %hu too large..\n", tdll);
212 		/* spc4r37 6.4.3.4 CSCD DESCRIPTOR LIST LENGTH field */
213 		*sense_ret = TCM_TOO_MANY_TARGET_DESCS;
214 		return -EINVAL;
215 	}
216 	/*
217 	 * Generate an IEEE Registered Extended designator based upon the
218 	 * se_device the XCOPY was received upon..
219 	 */
220 	memset(&xop->local_dev_wwn[0], 0, XCOPY_NAA_IEEE_REGEX_LEN);
221 	target_xcopy_gen_naa_ieee(local_dev, &xop->local_dev_wwn[0]);
222 
223 	while (start < tdll) {
224 		/*
225 		 * Check target descriptor identification with 0xE4 type, and
226 		 * compare the current index with the CSCD descriptor IDs in
227 		 * the segment descriptor. Use VPD 0x83 WWPN matching ..
228 		 */
229 		switch (desc[0]) {
230 		case 0xe4:
231 			rc = target_xcopy_parse_tiddesc_e4(se_cmd, xop,
232 							&desc[0], cscd_index);
233 			if (rc != 0)
234 				goto out;
235 			start += XCOPY_TARGET_DESC_LEN;
236 			desc += XCOPY_TARGET_DESC_LEN;
237 			cscd_index++;
238 			break;
239 		default:
240 			pr_err("XCOPY unsupported descriptor type code:"
241 					" 0x%02x\n", desc[0]);
242 			*sense_ret = TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE;
243 			goto out;
244 		}
245 	}
246 
247 	switch (xop->op_origin) {
248 	case XCOL_SOURCE_RECV_OP:
249 		rc = target_xcopy_locate_se_dev_e4(xop->dst_tid_wwn,
250 						&xop->dst_dev);
251 		break;
252 	case XCOL_DEST_RECV_OP:
253 		rc = target_xcopy_locate_se_dev_e4(xop->src_tid_wwn,
254 						&xop->src_dev);
255 		break;
256 	default:
257 		pr_err("XCOPY CSCD descriptor IDs not found in CSCD list - "
258 			"stdi: %hu dtdi: %hu\n", xop->stdi, xop->dtdi);
259 		rc = -EINVAL;
260 		break;
261 	}
262 	/*
263 	 * If a matching IEEE NAA 0x83 descriptor for the requested device
264 	 * is not located on this node, return COPY_ABORTED with ASQ/ASQC
265 	 * 0x0d/0x02 - COPY_TARGET_DEVICE_NOT_REACHABLE to request the
266 	 * initiator to fall back to normal copy method.
267 	 */
268 	if (rc < 0) {
269 		*sense_ret = TCM_COPY_TARGET_DEVICE_NOT_REACHABLE;
270 		goto out;
271 	}
272 
273 	pr_debug("XCOPY TGT desc: Source dev: %p NAA IEEE WWN: 0x%16phN\n",
274 		 xop->src_dev, &xop->src_tid_wwn[0]);
275 	pr_debug("XCOPY TGT desc: Dest dev: %p NAA IEEE WWN: 0x%16phN\n",
276 		 xop->dst_dev, &xop->dst_tid_wwn[0]);
277 
278 	return cscd_index;
279 
280 out:
281 	return -EINVAL;
282 }
283 
284 static int target_xcopy_parse_segdesc_02(struct se_cmd *se_cmd, struct xcopy_op *xop,
285 					unsigned char *p)
286 {
287 	unsigned char *desc = p;
288 	int dc = (desc[1] & 0x02);
289 	unsigned short desc_len;
290 
291 	desc_len = get_unaligned_be16(&desc[2]);
292 	if (desc_len != 0x18) {
293 		pr_err("XCOPY segment desc 0x02: Illegal desc_len:"
294 				" %hu\n", desc_len);
295 		return -EINVAL;
296 	}
297 
298 	xop->stdi = get_unaligned_be16(&desc[4]);
299 	xop->dtdi = get_unaligned_be16(&desc[6]);
300 
301 	if (xop->stdi > XCOPY_CSCD_DESC_ID_LIST_OFF_MAX ||
302 	    xop->dtdi > XCOPY_CSCD_DESC_ID_LIST_OFF_MAX) {
303 		pr_err("XCOPY segment desc 0x02: unsupported CSCD ID > 0x%x; stdi: %hu dtdi: %hu\n",
304 			XCOPY_CSCD_DESC_ID_LIST_OFF_MAX, xop->stdi, xop->dtdi);
305 		return -EINVAL;
306 	}
307 
308 	pr_debug("XCOPY seg desc 0x02: desc_len: %hu stdi: %hu dtdi: %hu, DC: %d\n",
309 		desc_len, xop->stdi, xop->dtdi, dc);
310 
311 	xop->nolb = get_unaligned_be16(&desc[10]);
312 	xop->src_lba = get_unaligned_be64(&desc[12]);
313 	xop->dst_lba = get_unaligned_be64(&desc[20]);
314 	pr_debug("XCOPY seg desc 0x02: nolb: %hu src_lba: %llu dst_lba: %llu\n",
315 		xop->nolb, (unsigned long long)xop->src_lba,
316 		(unsigned long long)xop->dst_lba);
317 
318 	if (dc != 0) {
319 		xop->dbl = get_unaligned_be24(&desc[29]);
320 
321 		pr_debug("XCOPY seg desc 0x02: DC=1 w/ dbl: %u\n", xop->dbl);
322 	}
323 	return 0;
324 }
325 
326 static int target_xcopy_parse_segment_descriptors(struct se_cmd *se_cmd,
327 				struct xcopy_op *xop, unsigned char *p,
328 				unsigned int sdll, sense_reason_t *sense_ret)
329 {
330 	unsigned char *desc = p;
331 	unsigned int start = 0;
332 	int offset = sdll % XCOPY_SEGMENT_DESC_LEN, rc, ret = 0;
333 
334 	*sense_ret = TCM_INVALID_PARAMETER_LIST;
335 
336 	if (offset != 0) {
337 		pr_err("XCOPY segment descriptor list length is not"
338 			" multiple of %d\n", XCOPY_SEGMENT_DESC_LEN);
339 		*sense_ret = TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE;
340 		return -EINVAL;
341 	}
342 	if (sdll > RCR_OP_MAX_SG_DESC_COUNT * XCOPY_SEGMENT_DESC_LEN) {
343 		pr_err("XCOPY supports %u segment descriptor(s), sdll: %u too"
344 			" large..\n", RCR_OP_MAX_SG_DESC_COUNT, sdll);
345 		/* spc4r37 6.4.3.5 SEGMENT DESCRIPTOR LIST LENGTH field */
346 		*sense_ret = TCM_TOO_MANY_SEGMENT_DESCS;
347 		return -EINVAL;
348 	}
349 
350 	while (start < sdll) {
351 		/*
352 		 * Check segment descriptor type code for block -> block
353 		 */
354 		switch (desc[0]) {
355 		case 0x02:
356 			rc = target_xcopy_parse_segdesc_02(se_cmd, xop, desc);
357 			if (rc < 0)
358 				goto out;
359 
360 			ret++;
361 			start += XCOPY_SEGMENT_DESC_LEN;
362 			desc += XCOPY_SEGMENT_DESC_LEN;
363 			break;
364 		default:
365 			pr_err("XCOPY unsupported segment descriptor"
366 				"type: 0x%02x\n", desc[0]);
367 			*sense_ret = TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE;
368 			goto out;
369 		}
370 	}
371 
372 	return ret;
373 
374 out:
375 	return -EINVAL;
376 }
377 
378 /*
379  * Start xcopy_pt ops
380  */
381 
382 struct xcopy_pt_cmd {
383 	struct se_cmd se_cmd;
384 	struct completion xpt_passthrough_sem;
385 	unsigned char sense_buffer[TRANSPORT_SENSE_BUFFER];
386 };
387 
388 struct se_portal_group xcopy_pt_tpg;
389 static struct se_session xcopy_pt_sess;
390 static struct se_node_acl xcopy_pt_nacl;
391 
392 static int xcopy_pt_get_cmd_state(struct se_cmd *se_cmd)
393 {
394         return 0;
395 }
396 
397 static void xcopy_pt_undepend_remotedev(struct xcopy_op *xop)
398 {
399 	struct se_device *remote_dev;
400 
401 	if (xop->op_origin == XCOL_SOURCE_RECV_OP)
402 		remote_dev = xop->dst_dev;
403 	else
404 		remote_dev = xop->src_dev;
405 
406 	pr_debug("Calling configfs_undepend_item for"
407 		  " remote_dev: %p remote_dev->dev_group: %p\n",
408 		  remote_dev, &remote_dev->dev_group.cg_item);
409 
410 	target_undepend_item(&remote_dev->dev_group.cg_item);
411 }
412 
413 static void xcopy_pt_release_cmd(struct se_cmd *se_cmd)
414 {
415 	struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,
416 				struct xcopy_pt_cmd, se_cmd);
417 
418 	kfree(xpt_cmd);
419 }
420 
421 static int xcopy_pt_check_stop_free(struct se_cmd *se_cmd)
422 {
423 	struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,
424 				struct xcopy_pt_cmd, se_cmd);
425 
426 	complete(&xpt_cmd->xpt_passthrough_sem);
427 	return 0;
428 }
429 
430 static int xcopy_pt_write_pending(struct se_cmd *se_cmd)
431 {
432 	return 0;
433 }
434 
435 static int xcopy_pt_queue_data_in(struct se_cmd *se_cmd)
436 {
437 	return 0;
438 }
439 
440 static int xcopy_pt_queue_status(struct se_cmd *se_cmd)
441 {
442 	return 0;
443 }
444 
445 static const struct target_core_fabric_ops xcopy_pt_tfo = {
446 	.fabric_name		= "xcopy-pt",
447 	.get_cmd_state		= xcopy_pt_get_cmd_state,
448 	.release_cmd		= xcopy_pt_release_cmd,
449 	.check_stop_free	= xcopy_pt_check_stop_free,
450 	.write_pending		= xcopy_pt_write_pending,
451 	.queue_data_in		= xcopy_pt_queue_data_in,
452 	.queue_status		= xcopy_pt_queue_status,
453 };
454 
455 /*
456  * End xcopy_pt_ops
457  */
458 
459 int target_xcopy_setup_pt(void)
460 {
461 	int ret;
462 
463 	xcopy_wq = alloc_workqueue("xcopy_wq", WQ_MEM_RECLAIM, 0);
464 	if (!xcopy_wq) {
465 		pr_err("Unable to allocate xcopy_wq\n");
466 		return -ENOMEM;
467 	}
468 
469 	memset(&xcopy_pt_tpg, 0, sizeof(struct se_portal_group));
470 	INIT_LIST_HEAD(&xcopy_pt_tpg.acl_node_list);
471 	INIT_LIST_HEAD(&xcopy_pt_tpg.tpg_sess_list);
472 
473 	xcopy_pt_tpg.se_tpg_tfo = &xcopy_pt_tfo;
474 
475 	memset(&xcopy_pt_nacl, 0, sizeof(struct se_node_acl));
476 	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_list);
477 	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_sess_list);
478 	memset(&xcopy_pt_sess, 0, sizeof(struct se_session));
479 	ret = transport_init_session(&xcopy_pt_sess);
480 	if (ret < 0)
481 		return ret;
482 
483 	xcopy_pt_nacl.se_tpg = &xcopy_pt_tpg;
484 	xcopy_pt_nacl.nacl_sess = &xcopy_pt_sess;
485 
486 	xcopy_pt_sess.se_tpg = &xcopy_pt_tpg;
487 	xcopy_pt_sess.se_node_acl = &xcopy_pt_nacl;
488 
489 	return 0;
490 }
491 
492 void target_xcopy_release_pt(void)
493 {
494 	if (xcopy_wq)
495 		destroy_workqueue(xcopy_wq);
496 }
497 
498 /*
499  * target_xcopy_setup_pt_cmd - set up a pass-through command
500  * @xpt_cmd:	 Data structure to initialize.
501  * @xop:	 Describes the XCOPY operation received from an initiator.
502  * @se_dev:	 Backend device to associate with @xpt_cmd if
503  *		 @remote_port == true.
504  * @cdb:	 SCSI CDB to be copied into @xpt_cmd.
505  * @remote_port: If false, use the LUN through which the XCOPY command has
506  *		 been received. If true, use @se_dev->xcopy_lun.
507  * @alloc_mem:	 Whether or not to allocate an SGL list.
508  *
509  * Set up a SCSI command (READ or WRITE) that will be used to execute an
510  * XCOPY command.
511  */
512 static int target_xcopy_setup_pt_cmd(
513 	struct xcopy_pt_cmd *xpt_cmd,
514 	struct xcopy_op *xop,
515 	struct se_device *se_dev,
516 	unsigned char *cdb,
517 	bool remote_port,
518 	bool alloc_mem)
519 {
520 	struct se_cmd *cmd = &xpt_cmd->se_cmd;
521 	sense_reason_t sense_rc;
522 	int ret = 0, rc;
523 
524 	/*
525 	 * Setup LUN+port to honor reservations based upon xop->op_origin for
526 	 * X-COPY PUSH or X-COPY PULL based upon where the CDB was received.
527 	 */
528 	if (remote_port) {
529 		cmd->se_lun = &se_dev->xcopy_lun;
530 		cmd->se_dev = se_dev;
531 	} else {
532 		cmd->se_lun = xop->xop_se_cmd->se_lun;
533 		cmd->se_dev = xop->xop_se_cmd->se_dev;
534 	}
535 	cmd->se_cmd_flags |= SCF_SE_LUN_CMD;
536 
537 	cmd->tag = 0;
538 	sense_rc = target_setup_cmd_from_cdb(cmd, cdb);
539 	if (sense_rc) {
540 		ret = -EINVAL;
541 		goto out;
542 	}
543 
544 	if (alloc_mem) {
545 		rc = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
546 				      cmd->data_length, false, false);
547 		if (rc < 0) {
548 			ret = rc;
549 			goto out;
550 		}
551 		/*
552 		 * Set this bit so that transport_free_pages() allows the
553 		 * caller to release SGLs + physical memory allocated by
554 		 * transport_generic_get_mem()..
555 		 */
556 		cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
557 	} else {
558 		/*
559 		 * Here the previously allocated SGLs for the internal READ
560 		 * are mapped zero-copy to the internal WRITE.
561 		 */
562 		sense_rc = transport_generic_map_mem_to_cmd(cmd,
563 					xop->xop_data_sg, xop->xop_data_nents,
564 					NULL, 0);
565 		if (sense_rc) {
566 			ret = -EINVAL;
567 			goto out;
568 		}
569 
570 		pr_debug("Setup PASSTHROUGH_NOALLOC t_data_sg: %p t_data_nents:"
571 			 " %u\n", cmd->t_data_sg, cmd->t_data_nents);
572 	}
573 
574 	return 0;
575 
576 out:
577 	return ret;
578 }
579 
580 static int target_xcopy_issue_pt_cmd(struct xcopy_pt_cmd *xpt_cmd)
581 {
582 	struct se_cmd *se_cmd = &xpt_cmd->se_cmd;
583 	sense_reason_t sense_rc;
584 
585 	sense_rc = transport_generic_new_cmd(se_cmd);
586 	if (sense_rc)
587 		return -EINVAL;
588 
589 	if (se_cmd->data_direction == DMA_TO_DEVICE)
590 		target_execute_cmd(se_cmd);
591 
592 	wait_for_completion_interruptible(&xpt_cmd->xpt_passthrough_sem);
593 
594 	pr_debug("target_xcopy_issue_pt_cmd(): SCSI status: 0x%02x\n",
595 			se_cmd->scsi_status);
596 
597 	return (se_cmd->scsi_status) ? -EINVAL : 0;
598 }
599 
600 static int target_xcopy_read_source(
601 	struct se_cmd *ec_cmd,
602 	struct xcopy_op *xop,
603 	struct se_device *src_dev,
604 	sector_t src_lba,
605 	u32 src_sectors)
606 {
607 	struct xcopy_pt_cmd *xpt_cmd;
608 	struct se_cmd *se_cmd;
609 	u32 length = (src_sectors * src_dev->dev_attrib.block_size);
610 	int rc;
611 	unsigned char cdb[16];
612 	bool remote_port = (xop->op_origin == XCOL_DEST_RECV_OP);
613 
614 	xpt_cmd = kzalloc(sizeof(struct xcopy_pt_cmd), GFP_KERNEL);
615 	if (!xpt_cmd) {
616 		pr_err("Unable to allocate xcopy_pt_cmd\n");
617 		return -ENOMEM;
618 	}
619 	init_completion(&xpt_cmd->xpt_passthrough_sem);
620 	se_cmd = &xpt_cmd->se_cmd;
621 
622 	memset(&cdb[0], 0, 16);
623 	cdb[0] = READ_16;
624 	put_unaligned_be64(src_lba, &cdb[2]);
625 	put_unaligned_be32(src_sectors, &cdb[10]);
626 	pr_debug("XCOPY: Built READ_16: LBA: %llu Sectors: %u Length: %u\n",
627 		(unsigned long long)src_lba, src_sectors, length);
628 
629 	transport_init_se_cmd(se_cmd, &xcopy_pt_tfo, &xcopy_pt_sess, length,
630 			      DMA_FROM_DEVICE, 0, &xpt_cmd->sense_buffer[0]);
631 	xop->src_pt_cmd = xpt_cmd;
632 
633 	rc = target_xcopy_setup_pt_cmd(xpt_cmd, xop, src_dev, &cdb[0],
634 				remote_port, true);
635 	if (rc < 0) {
636 		ec_cmd->scsi_status = xpt_cmd->se_cmd.scsi_status;
637 		transport_generic_free_cmd(se_cmd, 0);
638 		return rc;
639 	}
640 
641 	xop->xop_data_sg = se_cmd->t_data_sg;
642 	xop->xop_data_nents = se_cmd->t_data_nents;
643 	pr_debug("XCOPY-READ: Saved xop->xop_data_sg: %p, num: %u for READ"
644 		" memory\n", xop->xop_data_sg, xop->xop_data_nents);
645 
646 	rc = target_xcopy_issue_pt_cmd(xpt_cmd);
647 	if (rc < 0) {
648 		ec_cmd->scsi_status = xpt_cmd->se_cmd.scsi_status;
649 		transport_generic_free_cmd(se_cmd, 0);
650 		return rc;
651 	}
652 	/*
653 	 * Clear off the allocated t_data_sg, that has been saved for
654 	 * zero-copy WRITE submission reuse in struct xcopy_op..
655 	 */
656 	se_cmd->t_data_sg = NULL;
657 	se_cmd->t_data_nents = 0;
658 
659 	return 0;
660 }
661 
662 static int target_xcopy_write_destination(
663 	struct se_cmd *ec_cmd,
664 	struct xcopy_op *xop,
665 	struct se_device *dst_dev,
666 	sector_t dst_lba,
667 	u32 dst_sectors)
668 {
669 	struct xcopy_pt_cmd *xpt_cmd;
670 	struct se_cmd *se_cmd;
671 	u32 length = (dst_sectors * dst_dev->dev_attrib.block_size);
672 	int rc;
673 	unsigned char cdb[16];
674 	bool remote_port = (xop->op_origin == XCOL_SOURCE_RECV_OP);
675 
676 	xpt_cmd = kzalloc(sizeof(struct xcopy_pt_cmd), GFP_KERNEL);
677 	if (!xpt_cmd) {
678 		pr_err("Unable to allocate xcopy_pt_cmd\n");
679 		return -ENOMEM;
680 	}
681 	init_completion(&xpt_cmd->xpt_passthrough_sem);
682 	se_cmd = &xpt_cmd->se_cmd;
683 
684 	memset(&cdb[0], 0, 16);
685 	cdb[0] = WRITE_16;
686 	put_unaligned_be64(dst_lba, &cdb[2]);
687 	put_unaligned_be32(dst_sectors, &cdb[10]);
688 	pr_debug("XCOPY: Built WRITE_16: LBA: %llu Sectors: %u Length: %u\n",
689 		(unsigned long long)dst_lba, dst_sectors, length);
690 
691 	transport_init_se_cmd(se_cmd, &xcopy_pt_tfo, &xcopy_pt_sess, length,
692 			      DMA_TO_DEVICE, 0, &xpt_cmd->sense_buffer[0]);
693 	xop->dst_pt_cmd = xpt_cmd;
694 
695 	rc = target_xcopy_setup_pt_cmd(xpt_cmd, xop, dst_dev, &cdb[0],
696 				remote_port, false);
697 	if (rc < 0) {
698 		struct se_cmd *src_cmd = &xop->src_pt_cmd->se_cmd;
699 		ec_cmd->scsi_status = xpt_cmd->se_cmd.scsi_status;
700 		/*
701 		 * If the failure happened before the t_mem_list hand-off in
702 		 * target_xcopy_setup_pt_cmd(), Reset memory + clear flag so that
703 		 * core releases this memory on error during X-COPY WRITE I/O.
704 		 */
705 		src_cmd->se_cmd_flags &= ~SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
706 		src_cmd->t_data_sg = xop->xop_data_sg;
707 		src_cmd->t_data_nents = xop->xop_data_nents;
708 
709 		transport_generic_free_cmd(se_cmd, 0);
710 		return rc;
711 	}
712 
713 	rc = target_xcopy_issue_pt_cmd(xpt_cmd);
714 	if (rc < 0) {
715 		ec_cmd->scsi_status = xpt_cmd->se_cmd.scsi_status;
716 		se_cmd->se_cmd_flags &= ~SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
717 		transport_generic_free_cmd(se_cmd, 0);
718 		return rc;
719 	}
720 
721 	return 0;
722 }
723 
724 static void target_xcopy_do_work(struct work_struct *work)
725 {
726 	struct xcopy_op *xop = container_of(work, struct xcopy_op, xop_work);
727 	struct se_cmd *ec_cmd = xop->xop_se_cmd;
728 	struct se_device *src_dev, *dst_dev;
729 	sector_t src_lba, dst_lba, end_lba;
730 	unsigned int max_sectors;
731 	int rc = 0;
732 	unsigned short nolb, cur_nolb, max_nolb, copied_nolb = 0;
733 
734 	if (target_parse_xcopy_cmd(xop) != TCM_NO_SENSE)
735 		goto err_free;
736 
737 	if (WARN_ON_ONCE(!xop->src_dev) || WARN_ON_ONCE(!xop->dst_dev))
738 		goto err_free;
739 
740 	src_dev = xop->src_dev;
741 	dst_dev = xop->dst_dev;
742 	src_lba = xop->src_lba;
743 	dst_lba = xop->dst_lba;
744 	nolb = xop->nolb;
745 	end_lba = src_lba + nolb;
746 	/*
747 	 * Break up XCOPY I/O into hw_max_sectors sized I/O based on the
748 	 * smallest max_sectors between src_dev + dev_dev, or
749 	 */
750 	max_sectors = min(src_dev->dev_attrib.hw_max_sectors,
751 			  dst_dev->dev_attrib.hw_max_sectors);
752 	max_sectors = min_t(u32, max_sectors, XCOPY_MAX_SECTORS);
753 
754 	max_nolb = min_t(u16, max_sectors, ((u16)(~0U)));
755 
756 	pr_debug("target_xcopy_do_work: nolb: %hu, max_nolb: %hu end_lba: %llu\n",
757 			nolb, max_nolb, (unsigned long long)end_lba);
758 	pr_debug("target_xcopy_do_work: Starting src_lba: %llu, dst_lba: %llu\n",
759 			(unsigned long long)src_lba, (unsigned long long)dst_lba);
760 
761 	while (src_lba < end_lba) {
762 		cur_nolb = min(nolb, max_nolb);
763 
764 		pr_debug("target_xcopy_do_work: Calling read src_dev: %p src_lba: %llu,"
765 			" cur_nolb: %hu\n", src_dev, (unsigned long long)src_lba, cur_nolb);
766 
767 		rc = target_xcopy_read_source(ec_cmd, xop, src_dev, src_lba, cur_nolb);
768 		if (rc < 0)
769 			goto out;
770 
771 		src_lba += cur_nolb;
772 		pr_debug("target_xcopy_do_work: Incremented READ src_lba to %llu\n",
773 				(unsigned long long)src_lba);
774 
775 		pr_debug("target_xcopy_do_work: Calling write dst_dev: %p dst_lba: %llu,"
776 			" cur_nolb: %hu\n", dst_dev, (unsigned long long)dst_lba, cur_nolb);
777 
778 		rc = target_xcopy_write_destination(ec_cmd, xop, dst_dev,
779 						dst_lba, cur_nolb);
780 		if (rc < 0) {
781 			transport_generic_free_cmd(&xop->src_pt_cmd->se_cmd, 0);
782 			goto out;
783 		}
784 
785 		dst_lba += cur_nolb;
786 		pr_debug("target_xcopy_do_work: Incremented WRITE dst_lba to %llu\n",
787 				(unsigned long long)dst_lba);
788 
789 		copied_nolb += cur_nolb;
790 		nolb -= cur_nolb;
791 
792 		transport_generic_free_cmd(&xop->src_pt_cmd->se_cmd, 0);
793 		xop->dst_pt_cmd->se_cmd.se_cmd_flags &= ~SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
794 
795 		transport_generic_free_cmd(&xop->dst_pt_cmd->se_cmd, 0);
796 	}
797 
798 	xcopy_pt_undepend_remotedev(xop);
799 	kfree(xop);
800 
801 	pr_debug("target_xcopy_do_work: Final src_lba: %llu, dst_lba: %llu\n",
802 		(unsigned long long)src_lba, (unsigned long long)dst_lba);
803 	pr_debug("target_xcopy_do_work: Blocks copied: %hu, Bytes Copied: %u\n",
804 		copied_nolb, copied_nolb * dst_dev->dev_attrib.block_size);
805 
806 	pr_debug("target_xcopy_do_work: Setting X-COPY GOOD status -> sending response\n");
807 	target_complete_cmd(ec_cmd, SAM_STAT_GOOD);
808 	return;
809 
810 out:
811 	xcopy_pt_undepend_remotedev(xop);
812 
813 err_free:
814 	kfree(xop);
815 	/*
816 	 * Don't override an error scsi status if it has already been set
817 	 */
818 	if (ec_cmd->scsi_status == SAM_STAT_GOOD) {
819 		pr_warn_ratelimited("target_xcopy_do_work: rc: %d, Setting X-COPY"
820 			" CHECK_CONDITION -> sending response\n", rc);
821 		ec_cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
822 	}
823 	target_complete_cmd(ec_cmd, ec_cmd->scsi_status);
824 }
825 
826 /*
827  * Returns TCM_NO_SENSE upon success or a sense code != TCM_NO_SENSE if parsing
828  * fails.
829  */
830 static sense_reason_t target_parse_xcopy_cmd(struct xcopy_op *xop)
831 {
832 	struct se_cmd *se_cmd = xop->xop_se_cmd;
833 	unsigned char *p = NULL, *seg_desc;
834 	unsigned int list_id, list_id_usage, sdll, inline_dl;
835 	sense_reason_t ret = TCM_INVALID_PARAMETER_LIST;
836 	int rc;
837 	unsigned short tdll;
838 
839 	p = transport_kmap_data_sg(se_cmd);
840 	if (!p) {
841 		pr_err("transport_kmap_data_sg() failed in target_do_xcopy\n");
842 		return TCM_OUT_OF_RESOURCES;
843 	}
844 
845 	list_id = p[0];
846 	list_id_usage = (p[1] & 0x18) >> 3;
847 
848 	/*
849 	 * Determine TARGET DESCRIPTOR LIST LENGTH + SEGMENT DESCRIPTOR LIST LENGTH
850 	 */
851 	tdll = get_unaligned_be16(&p[2]);
852 	sdll = get_unaligned_be32(&p[8]);
853 	if (tdll + sdll > RCR_OP_MAX_DESC_LIST_LEN) {
854 		pr_err("XCOPY descriptor list length %u exceeds maximum %u\n",
855 		       tdll + sdll, RCR_OP_MAX_DESC_LIST_LEN);
856 		ret = TCM_PARAMETER_LIST_LENGTH_ERROR;
857 		goto out;
858 	}
859 
860 	inline_dl = get_unaligned_be32(&p[12]);
861 	if (inline_dl != 0) {
862 		pr_err("XCOPY with non zero inline data length\n");
863 		goto out;
864 	}
865 
866 	if (se_cmd->data_length < (XCOPY_HDR_LEN + tdll + sdll + inline_dl)) {
867 		pr_err("XCOPY parameter truncation: data length %u too small "
868 			"for tdll: %hu sdll: %u inline_dl: %u\n",
869 			se_cmd->data_length, tdll, sdll, inline_dl);
870 		ret = TCM_PARAMETER_LIST_LENGTH_ERROR;
871 		goto out;
872 	}
873 
874 	pr_debug("Processing XCOPY with list_id: 0x%02x list_id_usage: 0x%02x"
875 		" tdll: %hu sdll: %u inline_dl: %u\n", list_id, list_id_usage,
876 		tdll, sdll, inline_dl);
877 
878 	/*
879 	 * skip over the target descriptors until segment descriptors
880 	 * have been passed - CSCD ids are needed to determine src and dest.
881 	 */
882 	seg_desc = &p[16] + tdll;
883 
884 	rc = target_xcopy_parse_segment_descriptors(se_cmd, xop, seg_desc,
885 						    sdll, &ret);
886 	if (rc <= 0)
887 		goto out;
888 
889 	pr_debug("XCOPY: Processed %d segment descriptors, length: %u\n", rc,
890 				rc * XCOPY_SEGMENT_DESC_LEN);
891 
892 	rc = target_xcopy_parse_target_descriptors(se_cmd, xop, &p[16], tdll, &ret);
893 	if (rc <= 0)
894 		goto out;
895 
896 	if (xop->src_dev->dev_attrib.block_size !=
897 	    xop->dst_dev->dev_attrib.block_size) {
898 		pr_err("XCOPY: Non matching src_dev block_size: %u + dst_dev"
899 		       " block_size: %u currently unsupported\n",
900 			xop->src_dev->dev_attrib.block_size,
901 			xop->dst_dev->dev_attrib.block_size);
902 		xcopy_pt_undepend_remotedev(xop);
903 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
904 		goto out;
905 	}
906 
907 	pr_debug("XCOPY: Processed %d target descriptors, length: %u\n", rc,
908 				rc * XCOPY_TARGET_DESC_LEN);
909 	transport_kunmap_data_sg(se_cmd);
910 	return TCM_NO_SENSE;
911 
912 out:
913 	if (p)
914 		transport_kunmap_data_sg(se_cmd);
915 	return ret;
916 }
917 
918 sense_reason_t target_do_xcopy(struct se_cmd *se_cmd)
919 {
920 	struct se_device *dev = se_cmd->se_dev;
921 	struct xcopy_op *xop;
922 	unsigned int sa;
923 
924 	if (!dev->dev_attrib.emulate_3pc) {
925 		pr_err("EXTENDED_COPY operation explicitly disabled\n");
926 		return TCM_UNSUPPORTED_SCSI_OPCODE;
927 	}
928 
929 	sa = se_cmd->t_task_cdb[1] & 0x1f;
930 	if (sa != 0x00) {
931 		pr_err("EXTENDED_COPY(LID4) not supported\n");
932 		return TCM_UNSUPPORTED_SCSI_OPCODE;
933 	}
934 
935 	if (se_cmd->data_length == 0) {
936 		target_complete_cmd(se_cmd, SAM_STAT_GOOD);
937 		return TCM_NO_SENSE;
938 	}
939 	if (se_cmd->data_length < XCOPY_HDR_LEN) {
940 		pr_err("XCOPY parameter truncation: length %u < hdr_len %u\n",
941 				se_cmd->data_length, XCOPY_HDR_LEN);
942 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
943 	}
944 
945 	xop = kzalloc(sizeof(struct xcopy_op), GFP_KERNEL);
946 	if (!xop)
947 		goto err;
948 	xop->xop_se_cmd = se_cmd;
949 	INIT_WORK(&xop->xop_work, target_xcopy_do_work);
950 	if (WARN_ON_ONCE(!queue_work(xcopy_wq, &xop->xop_work)))
951 		goto free;
952 	return TCM_NO_SENSE;
953 
954 free:
955 	kfree(xop);
956 
957 err:
958 	return TCM_OUT_OF_RESOURCES;
959 }
960 
961 static sense_reason_t target_rcr_operating_parameters(struct se_cmd *se_cmd)
962 {
963 	unsigned char *p;
964 
965 	p = transport_kmap_data_sg(se_cmd);
966 	if (!p) {
967 		pr_err("transport_kmap_data_sg failed in"
968 		       " target_rcr_operating_parameters\n");
969 		return TCM_OUT_OF_RESOURCES;
970 	}
971 
972 	if (se_cmd->data_length < 54) {
973 		pr_err("Receive Copy Results Op Parameters length"
974 		       " too small: %u\n", se_cmd->data_length);
975 		transport_kunmap_data_sg(se_cmd);
976 		return TCM_INVALID_CDB_FIELD;
977 	}
978 	/*
979 	 * Set SNLID=1 (Supports no List ID)
980 	 */
981 	p[4] = 0x1;
982 	/*
983 	 * MAXIMUM TARGET DESCRIPTOR COUNT
984 	 */
985 	put_unaligned_be16(RCR_OP_MAX_TARGET_DESC_COUNT, &p[8]);
986 	/*
987 	 * MAXIMUM SEGMENT DESCRIPTOR COUNT
988 	 */
989 	put_unaligned_be16(RCR_OP_MAX_SG_DESC_COUNT, &p[10]);
990 	/*
991 	 * MAXIMUM DESCRIPTOR LIST LENGTH
992 	 */
993 	put_unaligned_be32(RCR_OP_MAX_DESC_LIST_LEN, &p[12]);
994 	/*
995 	 * MAXIMUM SEGMENT LENGTH
996 	 */
997 	put_unaligned_be32(RCR_OP_MAX_SEGMENT_LEN, &p[16]);
998 	/*
999 	 * MAXIMUM INLINE DATA LENGTH for SA 0x04 (NOT SUPPORTED)
1000 	 */
1001 	put_unaligned_be32(0x0, &p[20]);
1002 	/*
1003 	 * HELD DATA LIMIT
1004 	 */
1005 	put_unaligned_be32(0x0, &p[24]);
1006 	/*
1007 	 * MAXIMUM STREAM DEVICE TRANSFER SIZE
1008 	 */
1009 	put_unaligned_be32(0x0, &p[28]);
1010 	/*
1011 	 * TOTAL CONCURRENT COPIES
1012 	 */
1013 	put_unaligned_be16(RCR_OP_TOTAL_CONCURR_COPIES, &p[34]);
1014 	/*
1015 	 * MAXIMUM CONCURRENT COPIES
1016 	 */
1017 	p[36] = RCR_OP_MAX_CONCURR_COPIES;
1018 	/*
1019 	 * DATA SEGMENT GRANULARITY (log 2)
1020 	 */
1021 	p[37] = RCR_OP_DATA_SEG_GRAN_LOG2;
1022 	/*
1023 	 * INLINE DATA GRANULARITY log 2)
1024 	 */
1025 	p[38] = RCR_OP_INLINE_DATA_GRAN_LOG2;
1026 	/*
1027 	 * HELD DATA GRANULARITY
1028 	 */
1029 	p[39] = RCR_OP_HELD_DATA_GRAN_LOG2;
1030 	/*
1031 	 * IMPLEMENTED DESCRIPTOR LIST LENGTH
1032 	 */
1033 	p[43] = 0x2;
1034 	/*
1035 	 * List of implemented descriptor type codes (ordered)
1036 	 */
1037 	p[44] = 0x02; /* Copy Block to Block device */
1038 	p[45] = 0xe4; /* Identification descriptor target descriptor */
1039 
1040 	/*
1041 	 * AVAILABLE DATA (n-3)
1042 	 */
1043 	put_unaligned_be32(42, &p[0]);
1044 
1045 	transport_kunmap_data_sg(se_cmd);
1046 	target_complete_cmd(se_cmd, GOOD);
1047 
1048 	return TCM_NO_SENSE;
1049 }
1050 
1051 sense_reason_t target_do_receive_copy_results(struct se_cmd *se_cmd)
1052 {
1053 	unsigned char *cdb = &se_cmd->t_task_cdb[0];
1054 	int sa = (cdb[1] & 0x1f), list_id = cdb[2];
1055 	sense_reason_t rc = TCM_NO_SENSE;
1056 
1057 	pr_debug("Entering target_do_receive_copy_results: SA: 0x%02x, List ID:"
1058 		" 0x%02x, AL: %u\n", sa, list_id, se_cmd->data_length);
1059 
1060 	if (list_id != 0) {
1061 		pr_err("Receive Copy Results with non zero list identifier"
1062 		       " not supported\n");
1063 		return TCM_INVALID_CDB_FIELD;
1064 	}
1065 
1066 	switch (sa) {
1067 	case RCR_SA_OPERATING_PARAMETERS:
1068 		rc = target_rcr_operating_parameters(se_cmd);
1069 		break;
1070 	case RCR_SA_COPY_STATUS:
1071 	case RCR_SA_RECEIVE_DATA:
1072 	case RCR_SA_FAILED_SEGMENT_DETAILS:
1073 	default:
1074 		pr_err("Unsupported SA for receive copy results: 0x%02x\n", sa);
1075 		return TCM_INVALID_CDB_FIELD;
1076 	}
1077 
1078 	return rc;
1079 }
1080