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 != XCOPY_NAA_IEEE_REGEX_LEN) {
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 	return 0;
319 }
320 
321 static int target_xcopy_parse_segment_descriptors(struct se_cmd *se_cmd,
322 				struct xcopy_op *xop, unsigned char *p,
323 				unsigned int sdll, sense_reason_t *sense_ret)
324 {
325 	unsigned char *desc = p;
326 	unsigned int start = 0;
327 	int offset = sdll % XCOPY_SEGMENT_DESC_LEN, rc, ret = 0;
328 
329 	*sense_ret = TCM_INVALID_PARAMETER_LIST;
330 
331 	if (offset != 0) {
332 		pr_err("XCOPY segment descriptor list length is not"
333 			" multiple of %d\n", XCOPY_SEGMENT_DESC_LEN);
334 		*sense_ret = TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE;
335 		return -EINVAL;
336 	}
337 	if (sdll > RCR_OP_MAX_SG_DESC_COUNT * XCOPY_SEGMENT_DESC_LEN) {
338 		pr_err("XCOPY supports %u segment descriptor(s), sdll: %u too"
339 			" large..\n", RCR_OP_MAX_SG_DESC_COUNT, sdll);
340 		/* spc4r37 6.4.3.5 SEGMENT DESCRIPTOR LIST LENGTH field */
341 		*sense_ret = TCM_TOO_MANY_SEGMENT_DESCS;
342 		return -EINVAL;
343 	}
344 
345 	while (start < sdll) {
346 		/*
347 		 * Check segment descriptor type code for block -> block
348 		 */
349 		switch (desc[0]) {
350 		case 0x02:
351 			rc = target_xcopy_parse_segdesc_02(se_cmd, xop, desc);
352 			if (rc < 0)
353 				goto out;
354 
355 			ret++;
356 			start += XCOPY_SEGMENT_DESC_LEN;
357 			desc += XCOPY_SEGMENT_DESC_LEN;
358 			break;
359 		default:
360 			pr_err("XCOPY unsupported segment descriptor"
361 				"type: 0x%02x\n", desc[0]);
362 			*sense_ret = TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE;
363 			goto out;
364 		}
365 	}
366 
367 	return ret;
368 
369 out:
370 	return -EINVAL;
371 }
372 
373 /*
374  * Start xcopy_pt ops
375  */
376 
377 struct xcopy_pt_cmd {
378 	struct se_cmd se_cmd;
379 	struct completion xpt_passthrough_sem;
380 	unsigned char sense_buffer[TRANSPORT_SENSE_BUFFER];
381 };
382 
383 struct se_portal_group xcopy_pt_tpg;
384 static struct se_session xcopy_pt_sess;
385 static struct se_node_acl xcopy_pt_nacl;
386 
387 static int xcopy_pt_get_cmd_state(struct se_cmd *se_cmd)
388 {
389         return 0;
390 }
391 
392 static void xcopy_pt_undepend_remotedev(struct xcopy_op *xop)
393 {
394 	struct se_device *remote_dev;
395 
396 	if (xop->op_origin == XCOL_SOURCE_RECV_OP)
397 		remote_dev = xop->dst_dev;
398 	else
399 		remote_dev = xop->src_dev;
400 
401 	pr_debug("Calling configfs_undepend_item for"
402 		  " remote_dev: %p remote_dev->dev_group: %p\n",
403 		  remote_dev, &remote_dev->dev_group.cg_item);
404 
405 	target_undepend_item(&remote_dev->dev_group.cg_item);
406 }
407 
408 static void xcopy_pt_release_cmd(struct se_cmd *se_cmd)
409 {
410 	struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,
411 				struct xcopy_pt_cmd, se_cmd);
412 
413 	/* xpt_cmd is on the stack, nothing to free here */
414 	pr_debug("xpt_cmd done: %p\n", xpt_cmd);
415 }
416 
417 static int xcopy_pt_check_stop_free(struct se_cmd *se_cmd)
418 {
419 	struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,
420 				struct xcopy_pt_cmd, se_cmd);
421 
422 	complete(&xpt_cmd->xpt_passthrough_sem);
423 	return 0;
424 }
425 
426 static int xcopy_pt_write_pending(struct se_cmd *se_cmd)
427 {
428 	return 0;
429 }
430 
431 static int xcopy_pt_queue_data_in(struct se_cmd *se_cmd)
432 {
433 	return 0;
434 }
435 
436 static int xcopy_pt_queue_status(struct se_cmd *se_cmd)
437 {
438 	return 0;
439 }
440 
441 static const struct target_core_fabric_ops xcopy_pt_tfo = {
442 	.fabric_name		= "xcopy-pt",
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 	.queue_data_in		= xcopy_pt_queue_data_in,
448 	.queue_status		= xcopy_pt_queue_status,
449 };
450 
451 /*
452  * End xcopy_pt_ops
453  */
454 
455 int target_xcopy_setup_pt(void)
456 {
457 	int ret;
458 
459 	xcopy_wq = alloc_workqueue("xcopy_wq", WQ_MEM_RECLAIM, 0);
460 	if (!xcopy_wq) {
461 		pr_err("Unable to allocate xcopy_wq\n");
462 		return -ENOMEM;
463 	}
464 
465 	memset(&xcopy_pt_tpg, 0, sizeof(struct se_portal_group));
466 	INIT_LIST_HEAD(&xcopy_pt_tpg.acl_node_list);
467 	INIT_LIST_HEAD(&xcopy_pt_tpg.tpg_sess_list);
468 
469 	xcopy_pt_tpg.se_tpg_tfo = &xcopy_pt_tfo;
470 
471 	memset(&xcopy_pt_nacl, 0, sizeof(struct se_node_acl));
472 	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_list);
473 	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_sess_list);
474 	memset(&xcopy_pt_sess, 0, sizeof(struct se_session));
475 	ret = transport_init_session(&xcopy_pt_sess);
476 	if (ret < 0)
477 		return ret;
478 
479 	xcopy_pt_nacl.se_tpg = &xcopy_pt_tpg;
480 	xcopy_pt_nacl.nacl_sess = &xcopy_pt_sess;
481 
482 	xcopy_pt_sess.se_tpg = &xcopy_pt_tpg;
483 	xcopy_pt_sess.se_node_acl = &xcopy_pt_nacl;
484 
485 	return 0;
486 }
487 
488 void target_xcopy_release_pt(void)
489 {
490 	if (xcopy_wq)
491 		destroy_workqueue(xcopy_wq);
492 }
493 
494 /*
495  * target_xcopy_setup_pt_cmd - set up a pass-through command
496  * @xpt_cmd:	 Data structure to initialize.
497  * @xop:	 Describes the XCOPY operation received from an initiator.
498  * @se_dev:	 Backend device to associate with @xpt_cmd if
499  *		 @remote_port == true.
500  * @cdb:	 SCSI CDB to be copied into @xpt_cmd.
501  * @remote_port: If false, use the LUN through which the XCOPY command has
502  *		 been received. If true, use @se_dev->xcopy_lun.
503  *
504  * Set up a SCSI command (READ or WRITE) that will be used to execute an
505  * XCOPY command.
506  */
507 static int target_xcopy_setup_pt_cmd(
508 	struct xcopy_pt_cmd *xpt_cmd,
509 	struct xcopy_op *xop,
510 	struct se_device *se_dev,
511 	unsigned char *cdb,
512 	bool remote_port)
513 {
514 	struct se_cmd *cmd = &xpt_cmd->se_cmd;
515 
516 	/*
517 	 * Setup LUN+port to honor reservations based upon xop->op_origin for
518 	 * X-COPY PUSH or X-COPY PULL based upon where the CDB was received.
519 	 */
520 	if (remote_port) {
521 		cmd->se_lun = &se_dev->xcopy_lun;
522 		cmd->se_dev = se_dev;
523 	} else {
524 		cmd->se_lun = xop->xop_se_cmd->se_lun;
525 		cmd->se_dev = xop->xop_se_cmd->se_dev;
526 	}
527 	cmd->se_cmd_flags |= SCF_SE_LUN_CMD;
528 
529 	if (target_cmd_init_cdb(cmd, cdb))
530 		return -EINVAL;
531 
532 	cmd->tag = 0;
533 	if (target_cmd_parse_cdb(cmd))
534 		return -EINVAL;
535 
536 	if (transport_generic_map_mem_to_cmd(cmd, xop->xop_data_sg,
537 					xop->xop_data_nents, NULL, 0))
538 		return -EINVAL;
539 
540 	pr_debug("Setup PASSTHROUGH_NOALLOC t_data_sg: %p t_data_nents:"
541 		 " %u\n", cmd->t_data_sg, cmd->t_data_nents);
542 
543 	return 0;
544 }
545 
546 static int target_xcopy_issue_pt_cmd(struct xcopy_pt_cmd *xpt_cmd)
547 {
548 	struct se_cmd *se_cmd = &xpt_cmd->se_cmd;
549 	sense_reason_t sense_rc;
550 
551 	sense_rc = transport_generic_new_cmd(se_cmd);
552 	if (sense_rc)
553 		return -EINVAL;
554 
555 	if (se_cmd->data_direction == DMA_TO_DEVICE)
556 		target_execute_cmd(se_cmd);
557 
558 	wait_for_completion_interruptible(&xpt_cmd->xpt_passthrough_sem);
559 
560 	pr_debug("target_xcopy_issue_pt_cmd(): SCSI status: 0x%02x\n",
561 			se_cmd->scsi_status);
562 
563 	return (se_cmd->scsi_status) ? -EINVAL : 0;
564 }
565 
566 static int target_xcopy_read_source(
567 	struct se_cmd *ec_cmd,
568 	struct xcopy_op *xop,
569 	struct se_device *src_dev,
570 	sector_t src_lba,
571 	u32 src_sectors)
572 {
573 	struct xcopy_pt_cmd xpt_cmd;
574 	struct se_cmd *se_cmd = &xpt_cmd.se_cmd;
575 	u32 length = (src_sectors * src_dev->dev_attrib.block_size);
576 	int rc;
577 	unsigned char cdb[16];
578 	bool remote_port = (xop->op_origin == XCOL_DEST_RECV_OP);
579 
580 	memset(&xpt_cmd, 0, sizeof(xpt_cmd));
581 	init_completion(&xpt_cmd.xpt_passthrough_sem);
582 
583 	memset(&cdb[0], 0, 16);
584 	cdb[0] = READ_16;
585 	put_unaligned_be64(src_lba, &cdb[2]);
586 	put_unaligned_be32(src_sectors, &cdb[10]);
587 	pr_debug("XCOPY: Built READ_16: LBA: %llu Sectors: %u Length: %u\n",
588 		(unsigned long long)src_lba, src_sectors, length);
589 
590 	transport_init_se_cmd(se_cmd, &xcopy_pt_tfo, &xcopy_pt_sess, length,
591 			      DMA_FROM_DEVICE, 0, &xpt_cmd.sense_buffer[0], 0);
592 
593 	rc = target_xcopy_setup_pt_cmd(&xpt_cmd, xop, src_dev, &cdb[0],
594 				remote_port);
595 	if (rc < 0) {
596 		ec_cmd->scsi_status = se_cmd->scsi_status;
597 		goto out;
598 	}
599 
600 	pr_debug("XCOPY-READ: Saved xop->xop_data_sg: %p, num: %u for READ"
601 		" memory\n", xop->xop_data_sg, xop->xop_data_nents);
602 
603 	rc = target_xcopy_issue_pt_cmd(&xpt_cmd);
604 	if (rc < 0)
605 		ec_cmd->scsi_status = se_cmd->scsi_status;
606 out:
607 	transport_generic_free_cmd(se_cmd, 0);
608 	return rc;
609 }
610 
611 static int target_xcopy_write_destination(
612 	struct se_cmd *ec_cmd,
613 	struct xcopy_op *xop,
614 	struct se_device *dst_dev,
615 	sector_t dst_lba,
616 	u32 dst_sectors)
617 {
618 	struct xcopy_pt_cmd xpt_cmd;
619 	struct se_cmd *se_cmd = &xpt_cmd.se_cmd;
620 	u32 length = (dst_sectors * dst_dev->dev_attrib.block_size);
621 	int rc;
622 	unsigned char cdb[16];
623 	bool remote_port = (xop->op_origin == XCOL_SOURCE_RECV_OP);
624 
625 	memset(&xpt_cmd, 0, sizeof(xpt_cmd));
626 	init_completion(&xpt_cmd.xpt_passthrough_sem);
627 
628 	memset(&cdb[0], 0, 16);
629 	cdb[0] = WRITE_16;
630 	put_unaligned_be64(dst_lba, &cdb[2]);
631 	put_unaligned_be32(dst_sectors, &cdb[10]);
632 	pr_debug("XCOPY: Built WRITE_16: LBA: %llu Sectors: %u Length: %u\n",
633 		(unsigned long long)dst_lba, dst_sectors, length);
634 
635 	transport_init_se_cmd(se_cmd, &xcopy_pt_tfo, &xcopy_pt_sess, length,
636 			      DMA_TO_DEVICE, 0, &xpt_cmd.sense_buffer[0], 0);
637 
638 	rc = target_xcopy_setup_pt_cmd(&xpt_cmd, xop, dst_dev, &cdb[0],
639 				remote_port);
640 	if (rc < 0) {
641 		ec_cmd->scsi_status = se_cmd->scsi_status;
642 		goto out;
643 	}
644 
645 	rc = target_xcopy_issue_pt_cmd(&xpt_cmd);
646 	if (rc < 0)
647 		ec_cmd->scsi_status = se_cmd->scsi_status;
648 out:
649 	transport_generic_free_cmd(se_cmd, 0);
650 	return rc;
651 }
652 
653 static void target_xcopy_do_work(struct work_struct *work)
654 {
655 	struct xcopy_op *xop = container_of(work, struct xcopy_op, xop_work);
656 	struct se_cmd *ec_cmd = xop->xop_se_cmd;
657 	struct se_device *src_dev, *dst_dev;
658 	sector_t src_lba, dst_lba, end_lba;
659 	unsigned int max_sectors;
660 	int rc = 0;
661 	unsigned short nolb, max_nolb, copied_nolb = 0;
662 
663 	if (target_parse_xcopy_cmd(xop) != TCM_NO_SENSE)
664 		goto err_free;
665 
666 	if (WARN_ON_ONCE(!xop->src_dev) || WARN_ON_ONCE(!xop->dst_dev))
667 		goto err_free;
668 
669 	src_dev = xop->src_dev;
670 	dst_dev = xop->dst_dev;
671 	src_lba = xop->src_lba;
672 	dst_lba = xop->dst_lba;
673 	nolb = xop->nolb;
674 	end_lba = src_lba + nolb;
675 	/*
676 	 * Break up XCOPY I/O into hw_max_sectors sized I/O based on the
677 	 * smallest max_sectors between src_dev + dev_dev, or
678 	 */
679 	max_sectors = min(src_dev->dev_attrib.hw_max_sectors,
680 			  dst_dev->dev_attrib.hw_max_sectors);
681 	max_sectors = min_t(u32, max_sectors, XCOPY_MAX_SECTORS);
682 
683 	max_nolb = min_t(u16, max_sectors, ((u16)(~0U)));
684 
685 	pr_debug("target_xcopy_do_work: nolb: %hu, max_nolb: %hu end_lba: %llu\n",
686 			nolb, max_nolb, (unsigned long long)end_lba);
687 	pr_debug("target_xcopy_do_work: Starting src_lba: %llu, dst_lba: %llu\n",
688 			(unsigned long long)src_lba, (unsigned long long)dst_lba);
689 
690 	while (src_lba < end_lba) {
691 		unsigned short cur_nolb = min(nolb, max_nolb);
692 		u32 cur_bytes = cur_nolb * src_dev->dev_attrib.block_size;
693 
694 		if (cur_bytes != xop->xop_data_bytes) {
695 			/*
696 			 * (Re)allocate a buffer large enough to hold the XCOPY
697 			 * I/O size, which can be reused each read / write loop.
698 			 */
699 			target_free_sgl(xop->xop_data_sg, xop->xop_data_nents);
700 			rc = target_alloc_sgl(&xop->xop_data_sg,
701 					      &xop->xop_data_nents,
702 					      cur_bytes,
703 					      false, false);
704 			if (rc < 0)
705 				goto out;
706 			xop->xop_data_bytes = cur_bytes;
707 		}
708 
709 		pr_debug("target_xcopy_do_work: Calling read src_dev: %p src_lba: %llu,"
710 			" cur_nolb: %hu\n", src_dev, (unsigned long long)src_lba, cur_nolb);
711 
712 		rc = target_xcopy_read_source(ec_cmd, xop, src_dev, src_lba, cur_nolb);
713 		if (rc < 0)
714 			goto out;
715 
716 		src_lba += cur_nolb;
717 		pr_debug("target_xcopy_do_work: Incremented READ src_lba to %llu\n",
718 				(unsigned long long)src_lba);
719 
720 		pr_debug("target_xcopy_do_work: Calling write dst_dev: %p dst_lba: %llu,"
721 			" cur_nolb: %hu\n", dst_dev, (unsigned long long)dst_lba, cur_nolb);
722 
723 		rc = target_xcopy_write_destination(ec_cmd, xop, dst_dev,
724 						dst_lba, cur_nolb);
725 		if (rc < 0)
726 			goto out;
727 
728 		dst_lba += cur_nolb;
729 		pr_debug("target_xcopy_do_work: Incremented WRITE dst_lba to %llu\n",
730 				(unsigned long long)dst_lba);
731 
732 		copied_nolb += cur_nolb;
733 		nolb -= cur_nolb;
734 	}
735 
736 	xcopy_pt_undepend_remotedev(xop);
737 	target_free_sgl(xop->xop_data_sg, xop->xop_data_nents);
738 	kfree(xop);
739 
740 	pr_debug("target_xcopy_do_work: Final src_lba: %llu, dst_lba: %llu\n",
741 		(unsigned long long)src_lba, (unsigned long long)dst_lba);
742 	pr_debug("target_xcopy_do_work: Blocks copied: %hu, Bytes Copied: %u\n",
743 		copied_nolb, copied_nolb * dst_dev->dev_attrib.block_size);
744 
745 	pr_debug("target_xcopy_do_work: Setting X-COPY GOOD status -> sending response\n");
746 	target_complete_cmd(ec_cmd, SAM_STAT_GOOD);
747 	return;
748 
749 out:
750 	xcopy_pt_undepend_remotedev(xop);
751 	target_free_sgl(xop->xop_data_sg, xop->xop_data_nents);
752 
753 err_free:
754 	kfree(xop);
755 	/*
756 	 * Don't override an error scsi status if it has already been set
757 	 */
758 	if (ec_cmd->scsi_status == SAM_STAT_GOOD) {
759 		pr_warn_ratelimited("target_xcopy_do_work: rc: %d, Setting X-COPY"
760 			" CHECK_CONDITION -> sending response\n", rc);
761 		ec_cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
762 	}
763 	target_complete_cmd(ec_cmd, ec_cmd->scsi_status);
764 }
765 
766 /*
767  * Returns TCM_NO_SENSE upon success or a sense code != TCM_NO_SENSE if parsing
768  * fails.
769  */
770 static sense_reason_t target_parse_xcopy_cmd(struct xcopy_op *xop)
771 {
772 	struct se_cmd *se_cmd = xop->xop_se_cmd;
773 	unsigned char *p = NULL, *seg_desc;
774 	unsigned int list_id, list_id_usage, sdll, inline_dl;
775 	sense_reason_t ret = TCM_INVALID_PARAMETER_LIST;
776 	int rc;
777 	unsigned short tdll;
778 
779 	p = transport_kmap_data_sg(se_cmd);
780 	if (!p) {
781 		pr_err("transport_kmap_data_sg() failed in target_do_xcopy\n");
782 		return TCM_OUT_OF_RESOURCES;
783 	}
784 
785 	list_id = p[0];
786 	list_id_usage = (p[1] & 0x18) >> 3;
787 
788 	/*
789 	 * Determine TARGET DESCRIPTOR LIST LENGTH + SEGMENT DESCRIPTOR LIST LENGTH
790 	 */
791 	tdll = get_unaligned_be16(&p[2]);
792 	sdll = get_unaligned_be32(&p[8]);
793 	if (tdll + sdll > RCR_OP_MAX_DESC_LIST_LEN) {
794 		pr_err("XCOPY descriptor list length %u exceeds maximum %u\n",
795 		       tdll + sdll, RCR_OP_MAX_DESC_LIST_LEN);
796 		ret = TCM_PARAMETER_LIST_LENGTH_ERROR;
797 		goto out;
798 	}
799 
800 	inline_dl = get_unaligned_be32(&p[12]);
801 	if (inline_dl != 0) {
802 		pr_err("XCOPY with non zero inline data length\n");
803 		goto out;
804 	}
805 
806 	if (se_cmd->data_length < (XCOPY_HDR_LEN + tdll + sdll + inline_dl)) {
807 		pr_err("XCOPY parameter truncation: data length %u too small "
808 			"for tdll: %hu sdll: %u inline_dl: %u\n",
809 			se_cmd->data_length, tdll, sdll, inline_dl);
810 		ret = TCM_PARAMETER_LIST_LENGTH_ERROR;
811 		goto out;
812 	}
813 
814 	pr_debug("Processing XCOPY with list_id: 0x%02x list_id_usage: 0x%02x"
815 		" tdll: %hu sdll: %u inline_dl: %u\n", list_id, list_id_usage,
816 		tdll, sdll, inline_dl);
817 
818 	/*
819 	 * skip over the target descriptors until segment descriptors
820 	 * have been passed - CSCD ids are needed to determine src and dest.
821 	 */
822 	seg_desc = &p[16] + tdll;
823 
824 	rc = target_xcopy_parse_segment_descriptors(se_cmd, xop, seg_desc,
825 						    sdll, &ret);
826 	if (rc <= 0)
827 		goto out;
828 
829 	pr_debug("XCOPY: Processed %d segment descriptors, length: %u\n", rc,
830 				rc * XCOPY_SEGMENT_DESC_LEN);
831 
832 	rc = target_xcopy_parse_target_descriptors(se_cmd, xop, &p[16], tdll, &ret);
833 	if (rc <= 0)
834 		goto out;
835 
836 	if (xop->src_dev->dev_attrib.block_size !=
837 	    xop->dst_dev->dev_attrib.block_size) {
838 		pr_err("XCOPY: Non matching src_dev block_size: %u + dst_dev"
839 		       " block_size: %u currently unsupported\n",
840 			xop->src_dev->dev_attrib.block_size,
841 			xop->dst_dev->dev_attrib.block_size);
842 		xcopy_pt_undepend_remotedev(xop);
843 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
844 		goto out;
845 	}
846 
847 	pr_debug("XCOPY: Processed %d target descriptors, length: %u\n", rc,
848 				rc * XCOPY_TARGET_DESC_LEN);
849 	transport_kunmap_data_sg(se_cmd);
850 	return TCM_NO_SENSE;
851 
852 out:
853 	if (p)
854 		transport_kunmap_data_sg(se_cmd);
855 	return ret;
856 }
857 
858 sense_reason_t target_do_xcopy(struct se_cmd *se_cmd)
859 {
860 	struct se_device *dev = se_cmd->se_dev;
861 	struct xcopy_op *xop;
862 	unsigned int sa;
863 
864 	if (!dev->dev_attrib.emulate_3pc) {
865 		pr_err("EXTENDED_COPY operation explicitly disabled\n");
866 		return TCM_UNSUPPORTED_SCSI_OPCODE;
867 	}
868 
869 	sa = se_cmd->t_task_cdb[1] & 0x1f;
870 	if (sa != 0x00) {
871 		pr_err("EXTENDED_COPY(LID4) not supported\n");
872 		return TCM_UNSUPPORTED_SCSI_OPCODE;
873 	}
874 
875 	if (se_cmd->data_length == 0) {
876 		target_complete_cmd(se_cmd, SAM_STAT_GOOD);
877 		return TCM_NO_SENSE;
878 	}
879 	if (se_cmd->data_length < XCOPY_HDR_LEN) {
880 		pr_err("XCOPY parameter truncation: length %u < hdr_len %u\n",
881 				se_cmd->data_length, XCOPY_HDR_LEN);
882 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
883 	}
884 
885 	xop = kzalloc(sizeof(struct xcopy_op), GFP_KERNEL);
886 	if (!xop)
887 		goto err;
888 	xop->xop_se_cmd = se_cmd;
889 	INIT_WORK(&xop->xop_work, target_xcopy_do_work);
890 	if (WARN_ON_ONCE(!queue_work(xcopy_wq, &xop->xop_work)))
891 		goto free;
892 	return TCM_NO_SENSE;
893 
894 free:
895 	kfree(xop);
896 
897 err:
898 	return TCM_OUT_OF_RESOURCES;
899 }
900 
901 static sense_reason_t target_rcr_operating_parameters(struct se_cmd *se_cmd)
902 {
903 	unsigned char *p;
904 
905 	p = transport_kmap_data_sg(se_cmd);
906 	if (!p) {
907 		pr_err("transport_kmap_data_sg failed in"
908 		       " target_rcr_operating_parameters\n");
909 		return TCM_OUT_OF_RESOURCES;
910 	}
911 
912 	if (se_cmd->data_length < 54) {
913 		pr_err("Receive Copy Results Op Parameters length"
914 		       " too small: %u\n", se_cmd->data_length);
915 		transport_kunmap_data_sg(se_cmd);
916 		return TCM_INVALID_CDB_FIELD;
917 	}
918 	/*
919 	 * Set SNLID=1 (Supports no List ID)
920 	 */
921 	p[4] = 0x1;
922 	/*
923 	 * MAXIMUM TARGET DESCRIPTOR COUNT
924 	 */
925 	put_unaligned_be16(RCR_OP_MAX_TARGET_DESC_COUNT, &p[8]);
926 	/*
927 	 * MAXIMUM SEGMENT DESCRIPTOR COUNT
928 	 */
929 	put_unaligned_be16(RCR_OP_MAX_SG_DESC_COUNT, &p[10]);
930 	/*
931 	 * MAXIMUM DESCRIPTOR LIST LENGTH
932 	 */
933 	put_unaligned_be32(RCR_OP_MAX_DESC_LIST_LEN, &p[12]);
934 	/*
935 	 * MAXIMUM SEGMENT LENGTH
936 	 */
937 	put_unaligned_be32(RCR_OP_MAX_SEGMENT_LEN, &p[16]);
938 	/*
939 	 * MAXIMUM INLINE DATA LENGTH for SA 0x04 (NOT SUPPORTED)
940 	 */
941 	put_unaligned_be32(0x0, &p[20]);
942 	/*
943 	 * HELD DATA LIMIT
944 	 */
945 	put_unaligned_be32(0x0, &p[24]);
946 	/*
947 	 * MAXIMUM STREAM DEVICE TRANSFER SIZE
948 	 */
949 	put_unaligned_be32(0x0, &p[28]);
950 	/*
951 	 * TOTAL CONCURRENT COPIES
952 	 */
953 	put_unaligned_be16(RCR_OP_TOTAL_CONCURR_COPIES, &p[34]);
954 	/*
955 	 * MAXIMUM CONCURRENT COPIES
956 	 */
957 	p[36] = RCR_OP_MAX_CONCURR_COPIES;
958 	/*
959 	 * DATA SEGMENT GRANULARITY (log 2)
960 	 */
961 	p[37] = RCR_OP_DATA_SEG_GRAN_LOG2;
962 	/*
963 	 * INLINE DATA GRANULARITY log 2)
964 	 */
965 	p[38] = RCR_OP_INLINE_DATA_GRAN_LOG2;
966 	/*
967 	 * HELD DATA GRANULARITY
968 	 */
969 	p[39] = RCR_OP_HELD_DATA_GRAN_LOG2;
970 	/*
971 	 * IMPLEMENTED DESCRIPTOR LIST LENGTH
972 	 */
973 	p[43] = 0x2;
974 	/*
975 	 * List of implemented descriptor type codes (ordered)
976 	 */
977 	p[44] = 0x02; /* Copy Block to Block device */
978 	p[45] = 0xe4; /* Identification descriptor target descriptor */
979 
980 	/*
981 	 * AVAILABLE DATA (n-3)
982 	 */
983 	put_unaligned_be32(42, &p[0]);
984 
985 	transport_kunmap_data_sg(se_cmd);
986 	target_complete_cmd(se_cmd, GOOD);
987 
988 	return TCM_NO_SENSE;
989 }
990 
991 sense_reason_t target_do_receive_copy_results(struct se_cmd *se_cmd)
992 {
993 	unsigned char *cdb = &se_cmd->t_task_cdb[0];
994 	int sa = (cdb[1] & 0x1f), list_id = cdb[2];
995 	sense_reason_t rc = TCM_NO_SENSE;
996 
997 	pr_debug("Entering target_do_receive_copy_results: SA: 0x%02x, List ID:"
998 		" 0x%02x, AL: %u\n", sa, list_id, se_cmd->data_length);
999 
1000 	if (list_id != 0) {
1001 		pr_err("Receive Copy Results with non zero list identifier"
1002 		       " not supported\n");
1003 		return TCM_INVALID_CDB_FIELD;
1004 	}
1005 
1006 	switch (sa) {
1007 	case RCR_SA_OPERATING_PARAMETERS:
1008 		rc = target_rcr_operating_parameters(se_cmd);
1009 		break;
1010 	case RCR_SA_COPY_STATUS:
1011 	case RCR_SA_RECEIVE_DATA:
1012 	case RCR_SA_FAILED_SEGMENT_DETAILS:
1013 	default:
1014 		pr_err("Unsupported SA for receive copy results: 0x%02x\n", sa);
1015 		return TCM_INVALID_CDB_FIELD;
1016 	}
1017 
1018 	return rc;
1019 }
1020