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