xref: /openbmc/linux/drivers/target/target_core_xcopy.c (revision e4781421e883340b796da5a724bda7226817990b)
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 <linux/ratelimit.h>
29 #include <scsi/scsi_proto.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 
36 #include "target_core_internal.h"
37 #include "target_core_pr.h"
38 #include "target_core_ua.h"
39 #include "target_core_xcopy.h"
40 
41 static struct workqueue_struct *xcopy_wq = NULL;
42 
43 static int target_xcopy_gen_naa_ieee(struct se_device *dev, unsigned char *buf)
44 {
45 	int off = 0;
46 
47 	buf[off++] = (0x6 << 4);
48 	buf[off++] = 0x01;
49 	buf[off++] = 0x40;
50 	buf[off] = (0x5 << 4);
51 
52 	spc_parse_naa_6h_vendor_specific(dev, &buf[off]);
53 	return 0;
54 }
55 
56 static int target_xcopy_locate_se_dev_e4(struct se_cmd *se_cmd, struct xcopy_op *xop,
57 					bool src)
58 {
59 	struct se_device *se_dev;
60 	unsigned char tmp_dev_wwn[XCOPY_NAA_IEEE_REGEX_LEN], *dev_wwn;
61 	int rc;
62 
63 	if (src)
64 		dev_wwn = &xop->dst_tid_wwn[0];
65 	else
66 		dev_wwn = &xop->src_tid_wwn[0];
67 
68 	mutex_lock(&g_device_mutex);
69 	list_for_each_entry(se_dev, &g_device_list, g_dev_node) {
70 
71 		if (!se_dev->dev_attrib.emulate_3pc)
72 			continue;
73 
74 		memset(&tmp_dev_wwn[0], 0, XCOPY_NAA_IEEE_REGEX_LEN);
75 		target_xcopy_gen_naa_ieee(se_dev, &tmp_dev_wwn[0]);
76 
77 		rc = memcmp(&tmp_dev_wwn[0], dev_wwn, XCOPY_NAA_IEEE_REGEX_LEN);
78 		if (rc != 0)
79 			continue;
80 
81 		if (src) {
82 			xop->dst_dev = se_dev;
83 			pr_debug("XCOPY 0xe4: Setting xop->dst_dev: %p from located"
84 				" se_dev\n", xop->dst_dev);
85 		} else {
86 			xop->src_dev = se_dev;
87 			pr_debug("XCOPY 0xe4: Setting xop->src_dev: %p from located"
88 				" se_dev\n", xop->src_dev);
89 		}
90 
91 		rc = target_depend_item(&se_dev->dev_group.cg_item);
92 		if (rc != 0) {
93 			pr_err("configfs_depend_item attempt failed:"
94 				" %d for se_dev: %p\n", rc, se_dev);
95 			mutex_unlock(&g_device_mutex);
96 			return rc;
97 		}
98 
99 		pr_debug("Called configfs_depend_item for se_dev: %p"
100 			" se_dev->se_dev_group: %p\n", se_dev,
101 			&se_dev->dev_group);
102 
103 		mutex_unlock(&g_device_mutex);
104 		return 0;
105 	}
106 	mutex_unlock(&g_device_mutex);
107 
108 	pr_debug_ratelimited("Unable to locate 0xe4 descriptor for EXTENDED_COPY\n");
109 	return -EINVAL;
110 }
111 
112 static int target_xcopy_parse_tiddesc_e4(struct se_cmd *se_cmd, struct xcopy_op *xop,
113 				unsigned char *p, bool src)
114 {
115 	unsigned char *desc = p;
116 	unsigned short ript;
117 	u8 desig_len;
118 	/*
119 	 * Extract RELATIVE INITIATOR PORT IDENTIFIER
120 	 */
121 	ript = get_unaligned_be16(&desc[2]);
122 	pr_debug("XCOPY 0xe4: RELATIVE INITIATOR PORT IDENTIFIER: %hu\n", ript);
123 	/*
124 	 * Check for supported code set, association, and designator type
125 	 */
126 	if ((desc[4] & 0x0f) != 0x1) {
127 		pr_err("XCOPY 0xe4: code set of non binary type not supported\n");
128 		return -EINVAL;
129 	}
130 	if ((desc[5] & 0x30) != 0x00) {
131 		pr_err("XCOPY 0xe4: association other than LUN not supported\n");
132 		return -EINVAL;
133 	}
134 	if ((desc[5] & 0x0f) != 0x3) {
135 		pr_err("XCOPY 0xe4: designator type unsupported: 0x%02x\n",
136 				(desc[5] & 0x0f));
137 		return -EINVAL;
138 	}
139 	/*
140 	 * Check for matching 16 byte length for NAA IEEE Registered Extended
141 	 * Assigned designator
142 	 */
143 	desig_len = desc[7];
144 	if (desig_len != 16) {
145 		pr_err("XCOPY 0xe4: invalid desig_len: %d\n", (int)desig_len);
146 		return -EINVAL;
147 	}
148 	pr_debug("XCOPY 0xe4: desig_len: %d\n", (int)desig_len);
149 	/*
150 	 * Check for NAA IEEE Registered Extended Assigned header..
151 	 */
152 	if ((desc[8] & 0xf0) != 0x60) {
153 		pr_err("XCOPY 0xe4: Unsupported DESIGNATOR TYPE: 0x%02x\n",
154 					(desc[8] & 0xf0));
155 		return -EINVAL;
156 	}
157 
158 	if (src) {
159 		memcpy(&xop->src_tid_wwn[0], &desc[8], XCOPY_NAA_IEEE_REGEX_LEN);
160 		/*
161 		 * Determine if the source designator matches the local device
162 		 */
163 		if (!memcmp(&xop->local_dev_wwn[0], &xop->src_tid_wwn[0],
164 				XCOPY_NAA_IEEE_REGEX_LEN)) {
165 			xop->op_origin = XCOL_SOURCE_RECV_OP;
166 			xop->src_dev = se_cmd->se_dev;
167 			pr_debug("XCOPY 0xe4: Set xop->src_dev %p from source"
168 					" received xop\n", xop->src_dev);
169 		}
170 	} else {
171 		memcpy(&xop->dst_tid_wwn[0], &desc[8], XCOPY_NAA_IEEE_REGEX_LEN);
172 		/*
173 		 * Determine if the destination designator matches the local device
174 		 */
175 		if (!memcmp(&xop->local_dev_wwn[0], &xop->dst_tid_wwn[0],
176 				XCOPY_NAA_IEEE_REGEX_LEN)) {
177 			xop->op_origin = XCOL_DEST_RECV_OP;
178 			xop->dst_dev = se_cmd->se_dev;
179 			pr_debug("XCOPY 0xe4: Set xop->dst_dev: %p from destination"
180 				" received xop\n", xop->dst_dev);
181 		}
182 	}
183 
184 	return 0;
185 }
186 
187 static int target_xcopy_parse_target_descriptors(struct se_cmd *se_cmd,
188 				struct xcopy_op *xop, unsigned char *p,
189 				unsigned short tdll, sense_reason_t *sense_ret)
190 {
191 	struct se_device *local_dev = se_cmd->se_dev;
192 	unsigned char *desc = p;
193 	int offset = tdll % XCOPY_TARGET_DESC_LEN, rc, ret = 0;
194 	unsigned short start = 0;
195 	bool src = true;
196 
197 	*sense_ret = TCM_INVALID_PARAMETER_LIST;
198 
199 	if (offset != 0) {
200 		pr_err("XCOPY target descriptor list length is not"
201 			" multiple of %d\n", XCOPY_TARGET_DESC_LEN);
202 		return -EINVAL;
203 	}
204 	if (tdll > 64) {
205 		pr_err("XCOPY target descriptor supports a maximum"
206 			" two src/dest descriptors, tdll: %hu too large..\n", tdll);
207 		return -EINVAL;
208 	}
209 	/*
210 	 * Generate an IEEE Registered Extended designator based upon the
211 	 * se_device the XCOPY was received upon..
212 	 */
213 	memset(&xop->local_dev_wwn[0], 0, XCOPY_NAA_IEEE_REGEX_LEN);
214 	target_xcopy_gen_naa_ieee(local_dev, &xop->local_dev_wwn[0]);
215 
216 	while (start < tdll) {
217 		/*
218 		 * Check target descriptor identification with 0xE4 type with
219 		 * use VPD 0x83 WWPN matching ..
220 		 */
221 		switch (desc[0]) {
222 		case 0xe4:
223 			rc = target_xcopy_parse_tiddesc_e4(se_cmd, xop,
224 							&desc[0], src);
225 			if (rc != 0)
226 				goto out;
227 			/*
228 			 * Assume target descriptors are in source -> destination order..
229 			 */
230 			if (src)
231 				src = false;
232 			else
233 				src = true;
234 			start += XCOPY_TARGET_DESC_LEN;
235 			desc += XCOPY_TARGET_DESC_LEN;
236 			ret++;
237 			break;
238 		default:
239 			pr_err("XCOPY unsupported descriptor type code:"
240 					" 0x%02x\n", desc[0]);
241 			goto out;
242 		}
243 	}
244 
245 	if (xop->op_origin == XCOL_SOURCE_RECV_OP)
246 		rc = target_xcopy_locate_se_dev_e4(se_cmd, xop, true);
247 	else
248 		rc = target_xcopy_locate_se_dev_e4(se_cmd, xop, false);
249 	/*
250 	 * If a matching IEEE NAA 0x83 descriptor for the requested device
251 	 * is not located on this node, return COPY_ABORTED with ASQ/ASQC
252 	 * 0x0d/0x02 - COPY_TARGET_DEVICE_NOT_REACHABLE to request the
253 	 * initiator to fall back to normal copy method.
254 	 */
255 	if (rc < 0) {
256 		*sense_ret = TCM_COPY_TARGET_DEVICE_NOT_REACHABLE;
257 		goto out;
258 	}
259 
260 	pr_debug("XCOPY TGT desc: Source dev: %p NAA IEEE WWN: 0x%16phN\n",
261 		 xop->src_dev, &xop->src_tid_wwn[0]);
262 	pr_debug("XCOPY TGT desc: Dest dev: %p NAA IEEE WWN: 0x%16phN\n",
263 		 xop->dst_dev, &xop->dst_tid_wwn[0]);
264 
265 	return ret;
266 
267 out:
268 	return -EINVAL;
269 }
270 
271 static int target_xcopy_parse_segdesc_02(struct se_cmd *se_cmd, struct xcopy_op *xop,
272 					unsigned char *p)
273 {
274 	unsigned char *desc = p;
275 	int dc = (desc[1] & 0x02);
276 	unsigned short desc_len;
277 
278 	desc_len = get_unaligned_be16(&desc[2]);
279 	if (desc_len != 0x18) {
280 		pr_err("XCOPY segment desc 0x02: Illegal desc_len:"
281 				" %hu\n", desc_len);
282 		return -EINVAL;
283 	}
284 
285 	xop->stdi = get_unaligned_be16(&desc[4]);
286 	xop->dtdi = get_unaligned_be16(&desc[6]);
287 	pr_debug("XCOPY seg desc 0x02: desc_len: %hu stdi: %hu dtdi: %hu, DC: %d\n",
288 		desc_len, xop->stdi, xop->dtdi, dc);
289 
290 	xop->nolb = get_unaligned_be16(&desc[10]);
291 	xop->src_lba = get_unaligned_be64(&desc[12]);
292 	xop->dst_lba = get_unaligned_be64(&desc[20]);
293 	pr_debug("XCOPY seg desc 0x02: nolb: %hu src_lba: %llu dst_lba: %llu\n",
294 		xop->nolb, (unsigned long long)xop->src_lba,
295 		(unsigned long long)xop->dst_lba);
296 
297 	if (dc != 0) {
298 		xop->dbl = (desc[29] & 0xff) << 16;
299 		xop->dbl |= (desc[30] & 0xff) << 8;
300 		xop->dbl |= desc[31] & 0xff;
301 
302 		pr_debug("XCOPY seg desc 0x02: DC=1 w/ dbl: %u\n", xop->dbl);
303 	}
304 	return 0;
305 }
306 
307 static int target_xcopy_parse_segment_descriptors(struct se_cmd *se_cmd,
308 				struct xcopy_op *xop, unsigned char *p,
309 				unsigned int sdll)
310 {
311 	unsigned char *desc = p;
312 	unsigned int start = 0;
313 	int offset = sdll % XCOPY_SEGMENT_DESC_LEN, rc, ret = 0;
314 
315 	if (offset != 0) {
316 		pr_err("XCOPY segment descriptor list length is not"
317 			" multiple of %d\n", XCOPY_SEGMENT_DESC_LEN);
318 		return -EINVAL;
319 	}
320 
321 	while (start < sdll) {
322 		/*
323 		 * Check segment descriptor type code for block -> block
324 		 */
325 		switch (desc[0]) {
326 		case 0x02:
327 			rc = target_xcopy_parse_segdesc_02(se_cmd, xop, desc);
328 			if (rc < 0)
329 				goto out;
330 
331 			ret++;
332 			start += XCOPY_SEGMENT_DESC_LEN;
333 			desc += XCOPY_SEGMENT_DESC_LEN;
334 			break;
335 		default:
336 			pr_err("XCOPY unsupported segment descriptor"
337 				"type: 0x%02x\n", desc[0]);
338 			goto out;
339 		}
340 	}
341 
342 	return ret;
343 
344 out:
345 	return -EINVAL;
346 }
347 
348 /*
349  * Start xcopy_pt ops
350  */
351 
352 struct xcopy_pt_cmd {
353 	bool remote_port;
354 	struct se_cmd se_cmd;
355 	struct xcopy_op *xcopy_op;
356 	struct completion xpt_passthrough_sem;
357 	unsigned char sense_buffer[TRANSPORT_SENSE_BUFFER];
358 };
359 
360 struct se_portal_group xcopy_pt_tpg;
361 static struct se_session xcopy_pt_sess;
362 static struct se_node_acl xcopy_pt_nacl;
363 
364 static char *xcopy_pt_get_fabric_name(void)
365 {
366         return "xcopy-pt";
367 }
368 
369 static int xcopy_pt_get_cmd_state(struct se_cmd *se_cmd)
370 {
371         return 0;
372 }
373 
374 static void xcopy_pt_undepend_remotedev(struct xcopy_op *xop)
375 {
376 	struct se_device *remote_dev;
377 
378 	if (xop->op_origin == XCOL_SOURCE_RECV_OP)
379 		remote_dev = xop->dst_dev;
380 	else
381 		remote_dev = xop->src_dev;
382 
383 	pr_debug("Calling configfs_undepend_item for"
384 		  " remote_dev: %p remote_dev->dev_group: %p\n",
385 		  remote_dev, &remote_dev->dev_group.cg_item);
386 
387 	target_undepend_item(&remote_dev->dev_group.cg_item);
388 }
389 
390 static void xcopy_pt_release_cmd(struct se_cmd *se_cmd)
391 {
392 	struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,
393 				struct xcopy_pt_cmd, se_cmd);
394 
395 	kfree(xpt_cmd);
396 }
397 
398 static int xcopy_pt_check_stop_free(struct se_cmd *se_cmd)
399 {
400 	struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,
401 				struct xcopy_pt_cmd, se_cmd);
402 
403 	complete(&xpt_cmd->xpt_passthrough_sem);
404 	return 0;
405 }
406 
407 static int xcopy_pt_write_pending(struct se_cmd *se_cmd)
408 {
409 	return 0;
410 }
411 
412 static int xcopy_pt_write_pending_status(struct se_cmd *se_cmd)
413 {
414 	return 0;
415 }
416 
417 static int xcopy_pt_queue_data_in(struct se_cmd *se_cmd)
418 {
419 	return 0;
420 }
421 
422 static int xcopy_pt_queue_status(struct se_cmd *se_cmd)
423 {
424 	return 0;
425 }
426 
427 static const struct target_core_fabric_ops xcopy_pt_tfo = {
428 	.get_fabric_name	= xcopy_pt_get_fabric_name,
429 	.get_cmd_state		= xcopy_pt_get_cmd_state,
430 	.release_cmd		= xcopy_pt_release_cmd,
431 	.check_stop_free	= xcopy_pt_check_stop_free,
432 	.write_pending		= xcopy_pt_write_pending,
433 	.write_pending_status	= xcopy_pt_write_pending_status,
434 	.queue_data_in		= xcopy_pt_queue_data_in,
435 	.queue_status		= xcopy_pt_queue_status,
436 };
437 
438 /*
439  * End xcopy_pt_ops
440  */
441 
442 int target_xcopy_setup_pt(void)
443 {
444 	xcopy_wq = alloc_workqueue("xcopy_wq", WQ_MEM_RECLAIM, 0);
445 	if (!xcopy_wq) {
446 		pr_err("Unable to allocate xcopy_wq\n");
447 		return -ENOMEM;
448 	}
449 
450 	memset(&xcopy_pt_tpg, 0, sizeof(struct se_portal_group));
451 	INIT_LIST_HEAD(&xcopy_pt_tpg.se_tpg_node);
452 	INIT_LIST_HEAD(&xcopy_pt_tpg.acl_node_list);
453 	INIT_LIST_HEAD(&xcopy_pt_tpg.tpg_sess_list);
454 
455 	xcopy_pt_tpg.se_tpg_tfo = &xcopy_pt_tfo;
456 
457 	memset(&xcopy_pt_nacl, 0, sizeof(struct se_node_acl));
458 	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_list);
459 	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_sess_list);
460 	memset(&xcopy_pt_sess, 0, sizeof(struct se_session));
461 	INIT_LIST_HEAD(&xcopy_pt_sess.sess_list);
462 	INIT_LIST_HEAD(&xcopy_pt_sess.sess_acl_list);
463 	INIT_LIST_HEAD(&xcopy_pt_sess.sess_cmd_list);
464 	spin_lock_init(&xcopy_pt_sess.sess_cmd_lock);
465 
466 	xcopy_pt_nacl.se_tpg = &xcopy_pt_tpg;
467 	xcopy_pt_nacl.nacl_sess = &xcopy_pt_sess;
468 
469 	xcopy_pt_sess.se_tpg = &xcopy_pt_tpg;
470 	xcopy_pt_sess.se_node_acl = &xcopy_pt_nacl;
471 
472 	return 0;
473 }
474 
475 void target_xcopy_release_pt(void)
476 {
477 	if (xcopy_wq)
478 		destroy_workqueue(xcopy_wq);
479 }
480 
481 static void target_xcopy_setup_pt_port(
482 	struct xcopy_pt_cmd *xpt_cmd,
483 	struct xcopy_op *xop,
484 	bool remote_port)
485 {
486 	struct se_cmd *ec_cmd = xop->xop_se_cmd;
487 	struct se_cmd *pt_cmd = &xpt_cmd->se_cmd;
488 
489 	if (xop->op_origin == XCOL_SOURCE_RECV_OP) {
490 		/*
491 		 * Honor destination port reservations for X-COPY PUSH emulation
492 		 * when CDB is received on local source port, and READs blocks to
493 		 * WRITE on remote destination port.
494 		 */
495 		if (remote_port) {
496 			xpt_cmd->remote_port = remote_port;
497 		} else {
498 			pt_cmd->se_lun = ec_cmd->se_lun;
499 			pt_cmd->se_dev = ec_cmd->se_dev;
500 
501 			pr_debug("Honoring local SRC port from ec_cmd->se_dev:"
502 				" %p\n", pt_cmd->se_dev);
503 			pt_cmd->se_lun = ec_cmd->se_lun;
504 			pr_debug("Honoring local SRC port from ec_cmd->se_lun: %p\n",
505 				pt_cmd->se_lun);
506 		}
507 	} else {
508 		/*
509 		 * Honor source port reservation for X-COPY PULL emulation
510 		 * when CDB is received on local desintation port, and READs
511 		 * blocks from the remote source port to WRITE on local
512 		 * destination port.
513 		 */
514 		if (remote_port) {
515 			xpt_cmd->remote_port = remote_port;
516 		} else {
517 			pt_cmd->se_lun = ec_cmd->se_lun;
518 			pt_cmd->se_dev = ec_cmd->se_dev;
519 
520 			pr_debug("Honoring local DST port from ec_cmd->se_dev:"
521 				" %p\n", pt_cmd->se_dev);
522 			pt_cmd->se_lun = ec_cmd->se_lun;
523 			pr_debug("Honoring local DST port from ec_cmd->se_lun: %p\n",
524 				pt_cmd->se_lun);
525 		}
526 	}
527 }
528 
529 static void target_xcopy_init_pt_lun(struct se_device *se_dev,
530 		struct se_cmd *pt_cmd, bool remote_port)
531 {
532 	/*
533 	 * Don't allocate + init an pt_cmd->se_lun if honoring local port for
534 	 * reservations.  The pt_cmd->se_lun pointer will be setup from within
535 	 * target_xcopy_setup_pt_port()
536 	 */
537 	if (remote_port) {
538 		pr_debug("Setup emulated se_dev: %p from se_dev\n",
539 			pt_cmd->se_dev);
540 		pt_cmd->se_lun = &se_dev->xcopy_lun;
541 		pt_cmd->se_dev = se_dev;
542 	}
543 
544 	pt_cmd->se_cmd_flags |= SCF_SE_LUN_CMD;
545 }
546 
547 static int target_xcopy_setup_pt_cmd(
548 	struct xcopy_pt_cmd *xpt_cmd,
549 	struct xcopy_op *xop,
550 	struct se_device *se_dev,
551 	unsigned char *cdb,
552 	bool remote_port,
553 	bool alloc_mem)
554 {
555 	struct se_cmd *cmd = &xpt_cmd->se_cmd;
556 	sense_reason_t sense_rc;
557 	int ret = 0, rc;
558 	/*
559 	 * Setup LUN+port to honor reservations based upon xop->op_origin for
560 	 * X-COPY PUSH or X-COPY PULL based upon where the CDB was received.
561 	 */
562 	target_xcopy_init_pt_lun(se_dev, cmd, remote_port);
563 
564 	xpt_cmd->xcopy_op = xop;
565 	target_xcopy_setup_pt_port(xpt_cmd, xop, remote_port);
566 
567 	cmd->tag = 0;
568 	sense_rc = target_setup_cmd_from_cdb(cmd, cdb);
569 	if (sense_rc) {
570 		ret = -EINVAL;
571 		goto out;
572 	}
573 
574 	if (alloc_mem) {
575 		rc = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
576 				      cmd->data_length, false, false);
577 		if (rc < 0) {
578 			ret = rc;
579 			goto out;
580 		}
581 		/*
582 		 * Set this bit so that transport_free_pages() allows the
583 		 * caller to release SGLs + physical memory allocated by
584 		 * transport_generic_get_mem()..
585 		 */
586 		cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
587 	} else {
588 		/*
589 		 * Here the previously allocated SGLs for the internal READ
590 		 * are mapped zero-copy to the internal WRITE.
591 		 */
592 		sense_rc = transport_generic_map_mem_to_cmd(cmd,
593 					xop->xop_data_sg, xop->xop_data_nents,
594 					NULL, 0);
595 		if (sense_rc) {
596 			ret = -EINVAL;
597 			goto out;
598 		}
599 
600 		pr_debug("Setup PASSTHROUGH_NOALLOC t_data_sg: %p t_data_nents:"
601 			 " %u\n", cmd->t_data_sg, cmd->t_data_nents);
602 	}
603 
604 	return 0;
605 
606 out:
607 	return ret;
608 }
609 
610 static int target_xcopy_issue_pt_cmd(struct xcopy_pt_cmd *xpt_cmd)
611 {
612 	struct se_cmd *se_cmd = &xpt_cmd->se_cmd;
613 	sense_reason_t sense_rc;
614 
615 	sense_rc = transport_generic_new_cmd(se_cmd);
616 	if (sense_rc)
617 		return -EINVAL;
618 
619 	if (se_cmd->data_direction == DMA_TO_DEVICE)
620 		target_execute_cmd(se_cmd);
621 
622 	wait_for_completion_interruptible(&xpt_cmd->xpt_passthrough_sem);
623 
624 	pr_debug("target_xcopy_issue_pt_cmd(): SCSI status: 0x%02x\n",
625 			se_cmd->scsi_status);
626 
627 	return (se_cmd->scsi_status) ? -EINVAL : 0;
628 }
629 
630 static int target_xcopy_read_source(
631 	struct se_cmd *ec_cmd,
632 	struct xcopy_op *xop,
633 	struct se_device *src_dev,
634 	sector_t src_lba,
635 	u32 src_sectors)
636 {
637 	struct xcopy_pt_cmd *xpt_cmd;
638 	struct se_cmd *se_cmd;
639 	u32 length = (src_sectors * src_dev->dev_attrib.block_size);
640 	int rc;
641 	unsigned char cdb[16];
642 	bool remote_port = (xop->op_origin == XCOL_DEST_RECV_OP);
643 
644 	xpt_cmd = kzalloc(sizeof(struct xcopy_pt_cmd), GFP_KERNEL);
645 	if (!xpt_cmd) {
646 		pr_err("Unable to allocate xcopy_pt_cmd\n");
647 		return -ENOMEM;
648 	}
649 	init_completion(&xpt_cmd->xpt_passthrough_sem);
650 	se_cmd = &xpt_cmd->se_cmd;
651 
652 	memset(&cdb[0], 0, 16);
653 	cdb[0] = READ_16;
654 	put_unaligned_be64(src_lba, &cdb[2]);
655 	put_unaligned_be32(src_sectors, &cdb[10]);
656 	pr_debug("XCOPY: Built READ_16: LBA: %llu Sectors: %u Length: %u\n",
657 		(unsigned long long)src_lba, src_sectors, length);
658 
659 	transport_init_se_cmd(se_cmd, &xcopy_pt_tfo, &xcopy_pt_sess, length,
660 			      DMA_FROM_DEVICE, 0, &xpt_cmd->sense_buffer[0]);
661 	xop->src_pt_cmd = xpt_cmd;
662 
663 	rc = target_xcopy_setup_pt_cmd(xpt_cmd, xop, src_dev, &cdb[0],
664 				remote_port, true);
665 	if (rc < 0) {
666 		ec_cmd->scsi_status = xpt_cmd->se_cmd.scsi_status;
667 		transport_generic_free_cmd(se_cmd, 0);
668 		return rc;
669 	}
670 
671 	xop->xop_data_sg = se_cmd->t_data_sg;
672 	xop->xop_data_nents = se_cmd->t_data_nents;
673 	pr_debug("XCOPY-READ: Saved xop->xop_data_sg: %p, num: %u for READ"
674 		" memory\n", xop->xop_data_sg, xop->xop_data_nents);
675 
676 	rc = target_xcopy_issue_pt_cmd(xpt_cmd);
677 	if (rc < 0) {
678 		ec_cmd->scsi_status = xpt_cmd->se_cmd.scsi_status;
679 		transport_generic_free_cmd(se_cmd, 0);
680 		return rc;
681 	}
682 	/*
683 	 * Clear off the allocated t_data_sg, that has been saved for
684 	 * zero-copy WRITE submission reuse in struct xcopy_op..
685 	 */
686 	se_cmd->t_data_sg = NULL;
687 	se_cmd->t_data_nents = 0;
688 
689 	return 0;
690 }
691 
692 static int target_xcopy_write_destination(
693 	struct se_cmd *ec_cmd,
694 	struct xcopy_op *xop,
695 	struct se_device *dst_dev,
696 	sector_t dst_lba,
697 	u32 dst_sectors)
698 {
699 	struct xcopy_pt_cmd *xpt_cmd;
700 	struct se_cmd *se_cmd;
701 	u32 length = (dst_sectors * dst_dev->dev_attrib.block_size);
702 	int rc;
703 	unsigned char cdb[16];
704 	bool remote_port = (xop->op_origin == XCOL_SOURCE_RECV_OP);
705 
706 	xpt_cmd = kzalloc(sizeof(struct xcopy_pt_cmd), GFP_KERNEL);
707 	if (!xpt_cmd) {
708 		pr_err("Unable to allocate xcopy_pt_cmd\n");
709 		return -ENOMEM;
710 	}
711 	init_completion(&xpt_cmd->xpt_passthrough_sem);
712 	se_cmd = &xpt_cmd->se_cmd;
713 
714 	memset(&cdb[0], 0, 16);
715 	cdb[0] = WRITE_16;
716 	put_unaligned_be64(dst_lba, &cdb[2]);
717 	put_unaligned_be32(dst_sectors, &cdb[10]);
718 	pr_debug("XCOPY: Built WRITE_16: LBA: %llu Sectors: %u Length: %u\n",
719 		(unsigned long long)dst_lba, dst_sectors, length);
720 
721 	transport_init_se_cmd(se_cmd, &xcopy_pt_tfo, &xcopy_pt_sess, length,
722 			      DMA_TO_DEVICE, 0, &xpt_cmd->sense_buffer[0]);
723 	xop->dst_pt_cmd = xpt_cmd;
724 
725 	rc = target_xcopy_setup_pt_cmd(xpt_cmd, xop, dst_dev, &cdb[0],
726 				remote_port, false);
727 	if (rc < 0) {
728 		struct se_cmd *src_cmd = &xop->src_pt_cmd->se_cmd;
729 		ec_cmd->scsi_status = xpt_cmd->se_cmd.scsi_status;
730 		/*
731 		 * If the failure happened before the t_mem_list hand-off in
732 		 * target_xcopy_setup_pt_cmd(), Reset memory + clear flag so that
733 		 * core releases this memory on error during X-COPY WRITE I/O.
734 		 */
735 		src_cmd->se_cmd_flags &= ~SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
736 		src_cmd->t_data_sg = xop->xop_data_sg;
737 		src_cmd->t_data_nents = xop->xop_data_nents;
738 
739 		transport_generic_free_cmd(se_cmd, 0);
740 		return rc;
741 	}
742 
743 	rc = target_xcopy_issue_pt_cmd(xpt_cmd);
744 	if (rc < 0) {
745 		ec_cmd->scsi_status = xpt_cmd->se_cmd.scsi_status;
746 		se_cmd->se_cmd_flags &= ~SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
747 		transport_generic_free_cmd(se_cmd, 0);
748 		return rc;
749 	}
750 
751 	return 0;
752 }
753 
754 static void target_xcopy_do_work(struct work_struct *work)
755 {
756 	struct xcopy_op *xop = container_of(work, struct xcopy_op, xop_work);
757 	struct se_device *src_dev = xop->src_dev, *dst_dev = xop->dst_dev;
758 	struct se_cmd *ec_cmd = xop->xop_se_cmd;
759 	sector_t src_lba = xop->src_lba, dst_lba = xop->dst_lba, end_lba;
760 	unsigned int max_sectors;
761 	int rc;
762 	unsigned short nolb = xop->nolb, cur_nolb, max_nolb, copied_nolb = 0;
763 
764 	end_lba = src_lba + nolb;
765 	/*
766 	 * Break up XCOPY I/O into hw_max_sectors sized I/O based on the
767 	 * smallest max_sectors between src_dev + dev_dev, or
768 	 */
769 	max_sectors = min(src_dev->dev_attrib.hw_max_sectors,
770 			  dst_dev->dev_attrib.hw_max_sectors);
771 	max_sectors = min_t(u32, max_sectors, XCOPY_MAX_SECTORS);
772 
773 	max_nolb = min_t(u16, max_sectors, ((u16)(~0U)));
774 
775 	pr_debug("target_xcopy_do_work: nolb: %hu, max_nolb: %hu end_lba: %llu\n",
776 			nolb, max_nolb, (unsigned long long)end_lba);
777 	pr_debug("target_xcopy_do_work: Starting src_lba: %llu, dst_lba: %llu\n",
778 			(unsigned long long)src_lba, (unsigned long long)dst_lba);
779 
780 	while (src_lba < end_lba) {
781 		cur_nolb = min(nolb, max_nolb);
782 
783 		pr_debug("target_xcopy_do_work: Calling read src_dev: %p src_lba: %llu,"
784 			" cur_nolb: %hu\n", src_dev, (unsigned long long)src_lba, cur_nolb);
785 
786 		rc = target_xcopy_read_source(ec_cmd, xop, src_dev, src_lba, cur_nolb);
787 		if (rc < 0)
788 			goto out;
789 
790 		src_lba += cur_nolb;
791 		pr_debug("target_xcopy_do_work: Incremented READ src_lba to %llu\n",
792 				(unsigned long long)src_lba);
793 
794 		pr_debug("target_xcopy_do_work: Calling write dst_dev: %p dst_lba: %llu,"
795 			" cur_nolb: %hu\n", dst_dev, (unsigned long long)dst_lba, cur_nolb);
796 
797 		rc = target_xcopy_write_destination(ec_cmd, xop, dst_dev,
798 						dst_lba, cur_nolb);
799 		if (rc < 0) {
800 			transport_generic_free_cmd(&xop->src_pt_cmd->se_cmd, 0);
801 			goto out;
802 		}
803 
804 		dst_lba += cur_nolb;
805 		pr_debug("target_xcopy_do_work: Incremented WRITE dst_lba to %llu\n",
806 				(unsigned long long)dst_lba);
807 
808 		copied_nolb += cur_nolb;
809 		nolb -= cur_nolb;
810 
811 		transport_generic_free_cmd(&xop->src_pt_cmd->se_cmd, 0);
812 		xop->dst_pt_cmd->se_cmd.se_cmd_flags &= ~SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
813 
814 		transport_generic_free_cmd(&xop->dst_pt_cmd->se_cmd, 0);
815 	}
816 
817 	xcopy_pt_undepend_remotedev(xop);
818 	kfree(xop);
819 
820 	pr_debug("target_xcopy_do_work: Final src_lba: %llu, dst_lba: %llu\n",
821 		(unsigned long long)src_lba, (unsigned long long)dst_lba);
822 	pr_debug("target_xcopy_do_work: Blocks copied: %hu, Bytes Copied: %u\n",
823 		copied_nolb, copied_nolb * dst_dev->dev_attrib.block_size);
824 
825 	pr_debug("target_xcopy_do_work: Setting X-COPY GOOD status -> sending response\n");
826 	target_complete_cmd(ec_cmd, SAM_STAT_GOOD);
827 	return;
828 
829 out:
830 	xcopy_pt_undepend_remotedev(xop);
831 	kfree(xop);
832 	/*
833 	 * Don't override an error scsi status if it has already been set
834 	 */
835 	if (ec_cmd->scsi_status == SAM_STAT_GOOD) {
836 		pr_warn_ratelimited("target_xcopy_do_work: rc: %d, Setting X-COPY"
837 			" CHECK_CONDITION -> sending response\n", rc);
838 		ec_cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
839 	}
840 	target_complete_cmd(ec_cmd, SAM_STAT_CHECK_CONDITION);
841 }
842 
843 sense_reason_t target_do_xcopy(struct se_cmd *se_cmd)
844 {
845 	struct se_device *dev = se_cmd->se_dev;
846 	struct xcopy_op *xop = NULL;
847 	unsigned char *p = NULL, *seg_desc;
848 	unsigned int list_id, list_id_usage, sdll, inline_dl, sa;
849 	sense_reason_t ret = TCM_INVALID_PARAMETER_LIST;
850 	int rc;
851 	unsigned short tdll;
852 
853 	if (!dev->dev_attrib.emulate_3pc) {
854 		pr_err("EXTENDED_COPY operation explicitly disabled\n");
855 		return TCM_UNSUPPORTED_SCSI_OPCODE;
856 	}
857 
858 	sa = se_cmd->t_task_cdb[1] & 0x1f;
859 	if (sa != 0x00) {
860 		pr_err("EXTENDED_COPY(LID4) not supported\n");
861 		return TCM_UNSUPPORTED_SCSI_OPCODE;
862 	}
863 
864 	xop = kzalloc(sizeof(struct xcopy_op), GFP_KERNEL);
865 	if (!xop) {
866 		pr_err("Unable to allocate xcopy_op\n");
867 		return TCM_OUT_OF_RESOURCES;
868 	}
869 	xop->xop_se_cmd = se_cmd;
870 
871 	p = transport_kmap_data_sg(se_cmd);
872 	if (!p) {
873 		pr_err("transport_kmap_data_sg() failed in target_do_xcopy\n");
874 		kfree(xop);
875 		return TCM_OUT_OF_RESOURCES;
876 	}
877 
878 	list_id = p[0];
879 	list_id_usage = (p[1] & 0x18) >> 3;
880 
881 	/*
882 	 * Determine TARGET DESCRIPTOR LIST LENGTH + SEGMENT DESCRIPTOR LIST LENGTH
883 	 */
884 	tdll = get_unaligned_be16(&p[2]);
885 	sdll = get_unaligned_be32(&p[8]);
886 
887 	inline_dl = get_unaligned_be32(&p[12]);
888 	if (inline_dl != 0) {
889 		pr_err("XCOPY with non zero inline data length\n");
890 		goto out;
891 	}
892 
893 	pr_debug("Processing XCOPY with list_id: 0x%02x list_id_usage: 0x%02x"
894 		" tdll: %hu sdll: %u inline_dl: %u\n", list_id, list_id_usage,
895 		tdll, sdll, inline_dl);
896 
897 	rc = target_xcopy_parse_target_descriptors(se_cmd, xop, &p[16], tdll, &ret);
898 	if (rc <= 0)
899 		goto out;
900 
901 	if (xop->src_dev->dev_attrib.block_size !=
902 	    xop->dst_dev->dev_attrib.block_size) {
903 		pr_err("XCOPY: Non matching src_dev block_size: %u + dst_dev"
904 		       " block_size: %u currently unsupported\n",
905 			xop->src_dev->dev_attrib.block_size,
906 			xop->dst_dev->dev_attrib.block_size);
907 		xcopy_pt_undepend_remotedev(xop);
908 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
909 		goto out;
910 	}
911 
912 	pr_debug("XCOPY: Processed %d target descriptors, length: %u\n", rc,
913 				rc * XCOPY_TARGET_DESC_LEN);
914 	seg_desc = &p[16];
915 	seg_desc += (rc * XCOPY_TARGET_DESC_LEN);
916 
917 	rc = target_xcopy_parse_segment_descriptors(se_cmd, xop, seg_desc, sdll);
918 	if (rc <= 0) {
919 		xcopy_pt_undepend_remotedev(xop);
920 		goto out;
921 	}
922 	transport_kunmap_data_sg(se_cmd);
923 
924 	pr_debug("XCOPY: Processed %d segment descriptors, length: %u\n", rc,
925 				rc * XCOPY_SEGMENT_DESC_LEN);
926 	INIT_WORK(&xop->xop_work, target_xcopy_do_work);
927 	queue_work(xcopy_wq, &xop->xop_work);
928 	return TCM_NO_SENSE;
929 
930 out:
931 	if (p)
932 		transport_kunmap_data_sg(se_cmd);
933 	kfree(xop);
934 	return ret;
935 }
936 
937 static sense_reason_t target_rcr_operating_parameters(struct se_cmd *se_cmd)
938 {
939 	unsigned char *p;
940 
941 	p = transport_kmap_data_sg(se_cmd);
942 	if (!p) {
943 		pr_err("transport_kmap_data_sg failed in"
944 		       " target_rcr_operating_parameters\n");
945 		return TCM_OUT_OF_RESOURCES;
946 	}
947 
948 	if (se_cmd->data_length < 54) {
949 		pr_err("Receive Copy Results Op Parameters length"
950 		       " too small: %u\n", se_cmd->data_length);
951 		transport_kunmap_data_sg(se_cmd);
952 		return TCM_INVALID_CDB_FIELD;
953 	}
954 	/*
955 	 * Set SNLID=1 (Supports no List ID)
956 	 */
957 	p[4] = 0x1;
958 	/*
959 	 * MAXIMUM TARGET DESCRIPTOR COUNT
960 	 */
961 	put_unaligned_be16(RCR_OP_MAX_TARGET_DESC_COUNT, &p[8]);
962 	/*
963 	 * MAXIMUM SEGMENT DESCRIPTOR COUNT
964 	 */
965 	put_unaligned_be16(RCR_OP_MAX_SG_DESC_COUNT, &p[10]);
966 	/*
967 	 * MAXIMUM DESCRIPTOR LIST LENGTH
968 	 */
969 	put_unaligned_be32(RCR_OP_MAX_DESC_LIST_LEN, &p[12]);
970 	/*
971 	 * MAXIMUM SEGMENT LENGTH
972 	 */
973 	put_unaligned_be32(RCR_OP_MAX_SEGMENT_LEN, &p[16]);
974 	/*
975 	 * MAXIMUM INLINE DATA LENGTH for SA 0x04 (NOT SUPPORTED)
976 	 */
977 	put_unaligned_be32(0x0, &p[20]);
978 	/*
979 	 * HELD DATA LIMIT
980 	 */
981 	put_unaligned_be32(0x0, &p[24]);
982 	/*
983 	 * MAXIMUM STREAM DEVICE TRANSFER SIZE
984 	 */
985 	put_unaligned_be32(0x0, &p[28]);
986 	/*
987 	 * TOTAL CONCURRENT COPIES
988 	 */
989 	put_unaligned_be16(RCR_OP_TOTAL_CONCURR_COPIES, &p[34]);
990 	/*
991 	 * MAXIMUM CONCURRENT COPIES
992 	 */
993 	p[36] = RCR_OP_MAX_CONCURR_COPIES;
994 	/*
995 	 * DATA SEGMENT GRANULARITY (log 2)
996 	 */
997 	p[37] = RCR_OP_DATA_SEG_GRAN_LOG2;
998 	/*
999 	 * INLINE DATA GRANULARITY log 2)
1000 	 */
1001 	p[38] = RCR_OP_INLINE_DATA_GRAN_LOG2;
1002 	/*
1003 	 * HELD DATA GRANULARITY
1004 	 */
1005 	p[39] = RCR_OP_HELD_DATA_GRAN_LOG2;
1006 	/*
1007 	 * IMPLEMENTED DESCRIPTOR LIST LENGTH
1008 	 */
1009 	p[43] = 0x2;
1010 	/*
1011 	 * List of implemented descriptor type codes (ordered)
1012 	 */
1013 	p[44] = 0x02; /* Copy Block to Block device */
1014 	p[45] = 0xe4; /* Identification descriptor target descriptor */
1015 
1016 	/*
1017 	 * AVAILABLE DATA (n-3)
1018 	 */
1019 	put_unaligned_be32(42, &p[0]);
1020 
1021 	transport_kunmap_data_sg(se_cmd);
1022 	target_complete_cmd(se_cmd, GOOD);
1023 
1024 	return TCM_NO_SENSE;
1025 }
1026 
1027 sense_reason_t target_do_receive_copy_results(struct se_cmd *se_cmd)
1028 {
1029 	unsigned char *cdb = &se_cmd->t_task_cdb[0];
1030 	int sa = (cdb[1] & 0x1f), list_id = cdb[2];
1031 	sense_reason_t rc = TCM_NO_SENSE;
1032 
1033 	pr_debug("Entering target_do_receive_copy_results: SA: 0x%02x, List ID:"
1034 		" 0x%02x, AL: %u\n", sa, list_id, se_cmd->data_length);
1035 
1036 	if (list_id != 0) {
1037 		pr_err("Receive Copy Results with non zero list identifier"
1038 		       " not supported\n");
1039 		return TCM_INVALID_CDB_FIELD;
1040 	}
1041 
1042 	switch (sa) {
1043 	case RCR_SA_OPERATING_PARAMETERS:
1044 		rc = target_rcr_operating_parameters(se_cmd);
1045 		break;
1046 	case RCR_SA_COPY_STATUS:
1047 	case RCR_SA_RECEIVE_DATA:
1048 	case RCR_SA_FAILED_SEGMENT_DETAILS:
1049 	default:
1050 		pr_err("Unsupported SA for receive copy results: 0x%02x\n", sa);
1051 		return TCM_INVALID_CDB_FIELD;
1052 	}
1053 
1054 	return rc;
1055 }
1056