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