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_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  * From target_core_spc.c
44  */
45 extern void spc_parse_naa_6h_vendor_specific(struct se_device *, unsigned char *);
46 /*
47  * From target_core_device.c
48  */
49 extern struct mutex g_device_mutex;
50 extern struct list_head g_device_list;
51 /*
52  * From target_core_configfs.c
53  */
54 extern struct configfs_subsystem *target_core_subsystem[];
55 
56 static int target_xcopy_gen_naa_ieee(struct se_device *dev, unsigned char *buf)
57 {
58 	int off = 0;
59 
60 	buf[off++] = (0x6 << 4);
61 	buf[off++] = 0x01;
62 	buf[off++] = 0x40;
63 	buf[off] = (0x5 << 4);
64 
65 	spc_parse_naa_6h_vendor_specific(dev, &buf[off]);
66 	return 0;
67 }
68 
69 static int target_xcopy_locate_se_dev_e4(struct se_cmd *se_cmd, struct xcopy_op *xop,
70 					bool src)
71 {
72 	struct se_device *se_dev;
73 	struct configfs_subsystem *subsys = target_core_subsystem[0];
74 	unsigned char tmp_dev_wwn[XCOPY_NAA_IEEE_REGEX_LEN], *dev_wwn;
75 	int rc;
76 
77 	if (src == true)
78 		dev_wwn = &xop->dst_tid_wwn[0];
79 	else
80 		dev_wwn = &xop->src_tid_wwn[0];
81 
82 	mutex_lock(&g_device_mutex);
83 	list_for_each_entry(se_dev, &g_device_list, g_dev_node) {
84 
85 		memset(&tmp_dev_wwn[0], 0, XCOPY_NAA_IEEE_REGEX_LEN);
86 		target_xcopy_gen_naa_ieee(se_dev, &tmp_dev_wwn[0]);
87 
88 		rc = memcmp(&tmp_dev_wwn[0], dev_wwn, XCOPY_NAA_IEEE_REGEX_LEN);
89 		if (rc != 0)
90 			continue;
91 
92 		if (src == true) {
93 			xop->dst_dev = se_dev;
94 			pr_debug("XCOPY 0xe4: Setting xop->dst_dev: %p from located"
95 				" se_dev\n", xop->dst_dev);
96 		} else {
97 			xop->src_dev = se_dev;
98 			pr_debug("XCOPY 0xe4: Setting xop->src_dev: %p from located"
99 				" se_dev\n", xop->src_dev);
100 		}
101 
102 		rc = configfs_depend_item(subsys,
103 				&se_dev->dev_group.cg_item);
104 		if (rc != 0) {
105 			pr_err("configfs_depend_item attempt failed:"
106 				" %d for se_dev: %p\n", rc, se_dev);
107 			mutex_unlock(&g_device_mutex);
108 			return rc;
109 		}
110 
111 		pr_debug("Called configfs_depend_item for subsys: %p se_dev: %p"
112 			" se_dev->se_dev_group: %p\n", subsys, se_dev,
113 			&se_dev->dev_group);
114 
115 		mutex_unlock(&g_device_mutex);
116 		return 0;
117 	}
118 	mutex_unlock(&g_device_mutex);
119 
120 	pr_err("Unable to locate 0xe4 descriptor for EXTENDED_COPY\n");
121 	return -EINVAL;
122 }
123 
124 static int target_xcopy_parse_tiddesc_e4(struct se_cmd *se_cmd, struct xcopy_op *xop,
125 				unsigned char *p, bool src)
126 {
127 	unsigned char *desc = p;
128 	unsigned short ript;
129 	u8 desig_len;
130 	/*
131 	 * Extract RELATIVE INITIATOR PORT IDENTIFIER
132 	 */
133 	ript = get_unaligned_be16(&desc[2]);
134 	pr_debug("XCOPY 0xe4: RELATIVE INITIATOR PORT IDENTIFIER: %hu\n", ript);
135 	/*
136 	 * Check for supported code set, association, and designator type
137 	 */
138 	if ((desc[4] & 0x0f) != 0x1) {
139 		pr_err("XCOPY 0xe4: code set of non binary type not supported\n");
140 		return -EINVAL;
141 	}
142 	if ((desc[5] & 0x30) != 0x00) {
143 		pr_err("XCOPY 0xe4: association other than LUN not supported\n");
144 		return -EINVAL;
145 	}
146 	if ((desc[5] & 0x0f) != 0x3) {
147 		pr_err("XCOPY 0xe4: designator type unsupported: 0x%02x\n",
148 				(desc[5] & 0x0f));
149 		return -EINVAL;
150 	}
151 	/*
152 	 * Check for matching 16 byte length for NAA IEEE Registered Extended
153 	 * Assigned designator
154 	 */
155 	desig_len = desc[7];
156 	if (desig_len != 16) {
157 		pr_err("XCOPY 0xe4: invalid desig_len: %d\n", (int)desig_len);
158 		return -EINVAL;
159 	}
160 	pr_debug("XCOPY 0xe4: desig_len: %d\n", (int)desig_len);
161 	/*
162 	 * Check for NAA IEEE Registered Extended Assigned header..
163 	 */
164 	if ((desc[8] & 0xf0) != 0x60) {
165 		pr_err("XCOPY 0xe4: Unsupported DESIGNATOR TYPE: 0x%02x\n",
166 					(desc[8] & 0xf0));
167 		return -EINVAL;
168 	}
169 
170 	if (src == true) {
171 		memcpy(&xop->src_tid_wwn[0], &desc[8], XCOPY_NAA_IEEE_REGEX_LEN);
172 		/*
173 		 * Determine if the source designator matches the local device
174 		 */
175 		if (!memcmp(&xop->local_dev_wwn[0], &xop->src_tid_wwn[0],
176 				XCOPY_NAA_IEEE_REGEX_LEN)) {
177 			xop->op_origin = XCOL_SOURCE_RECV_OP;
178 			xop->src_dev = se_cmd->se_dev;
179 			pr_debug("XCOPY 0xe4: Set xop->src_dev %p from source"
180 					" received xop\n", xop->src_dev);
181 		}
182 	} else {
183 		memcpy(&xop->dst_tid_wwn[0], &desc[8], XCOPY_NAA_IEEE_REGEX_LEN);
184 		/*
185 		 * Determine if the destination designator matches the local device
186 		 */
187 		if (!memcmp(&xop->local_dev_wwn[0], &xop->dst_tid_wwn[0],
188 				XCOPY_NAA_IEEE_REGEX_LEN)) {
189 			xop->op_origin = XCOL_DEST_RECV_OP;
190 			xop->dst_dev = se_cmd->se_dev;
191 			pr_debug("XCOPY 0xe4: Set xop->dst_dev: %p from destination"
192 				" received xop\n", xop->dst_dev);
193 		}
194 	}
195 
196 	return 0;
197 }
198 
199 static int target_xcopy_parse_target_descriptors(struct se_cmd *se_cmd,
200 				struct xcopy_op *xop, unsigned char *p,
201 				unsigned short tdll)
202 {
203 	struct se_device *local_dev = se_cmd->se_dev;
204 	unsigned char *desc = p;
205 	int offset = tdll % XCOPY_TARGET_DESC_LEN, rc, ret = 0;
206 	unsigned short start = 0;
207 	bool src = true;
208 
209 	if (offset != 0) {
210 		pr_err("XCOPY target descriptor list length is not"
211 			" multiple of %d\n", XCOPY_TARGET_DESC_LEN);
212 		return -EINVAL;
213 	}
214 	if (tdll > 64) {
215 		pr_err("XCOPY target descriptor supports a maximum"
216 			" two src/dest descriptors, tdll: %hu too large..\n", tdll);
217 		return -EINVAL;
218 	}
219 	/*
220 	 * Generate an IEEE Registered Extended designator based upon the
221 	 * se_device the XCOPY was received upon..
222 	 */
223 	memset(&xop->local_dev_wwn[0], 0, XCOPY_NAA_IEEE_REGEX_LEN);
224 	target_xcopy_gen_naa_ieee(local_dev, &xop->local_dev_wwn[0]);
225 
226 	while (start < tdll) {
227 		/*
228 		 * Check target descriptor identification with 0xE4 type with
229 		 * use VPD 0x83 WWPN matching ..
230 		 */
231 		switch (desc[0]) {
232 		case 0xe4:
233 			rc = target_xcopy_parse_tiddesc_e4(se_cmd, xop,
234 							&desc[0], src);
235 			if (rc != 0)
236 				goto out;
237 			/*
238 			 * Assume target descriptors are in source -> destination order..
239 			 */
240 			if (src == true)
241 				src = false;
242 			else
243 				src = true;
244 			start += XCOPY_TARGET_DESC_LEN;
245 			desc += XCOPY_TARGET_DESC_LEN;
246 			ret++;
247 			break;
248 		default:
249 			pr_err("XCOPY unsupported descriptor type code:"
250 					" 0x%02x\n", desc[0]);
251 			goto out;
252 		}
253 	}
254 
255 	if (xop->op_origin == XCOL_SOURCE_RECV_OP)
256 		rc = target_xcopy_locate_se_dev_e4(se_cmd, xop, true);
257 	else
258 		rc = target_xcopy_locate_se_dev_e4(se_cmd, xop, false);
259 
260 	if (rc < 0)
261 		goto out;
262 
263 	pr_debug("XCOPY TGT desc: Source dev: %p NAA IEEE WWN: 0x%16phN\n",
264 		 xop->src_dev, &xop->src_tid_wwn[0]);
265 	pr_debug("XCOPY TGT desc: Dest dev: %p NAA IEEE WWN: 0x%16phN\n",
266 		 xop->dst_dev, &xop->dst_tid_wwn[0]);
267 
268 	return ret;
269 
270 out:
271 	return -EINVAL;
272 }
273 
274 static int target_xcopy_parse_segdesc_02(struct se_cmd *se_cmd, struct xcopy_op *xop,
275 					unsigned char *p)
276 {
277 	unsigned char *desc = p;
278 	int dc = (desc[1] & 0x02);
279 	unsigned short desc_len;
280 
281 	desc_len = get_unaligned_be16(&desc[2]);
282 	if (desc_len != 0x18) {
283 		pr_err("XCOPY segment desc 0x02: Illegal desc_len:"
284 				" %hu\n", desc_len);
285 		return -EINVAL;
286 	}
287 
288 	xop->stdi = get_unaligned_be16(&desc[4]);
289 	xop->dtdi = get_unaligned_be16(&desc[6]);
290 	pr_debug("XCOPY seg desc 0x02: desc_len: %hu stdi: %hu dtdi: %hu, DC: %d\n",
291 		desc_len, xop->stdi, xop->dtdi, dc);
292 
293 	xop->nolb = get_unaligned_be16(&desc[10]);
294 	xop->src_lba = get_unaligned_be64(&desc[12]);
295 	xop->dst_lba = get_unaligned_be64(&desc[20]);
296 	pr_debug("XCOPY seg desc 0x02: nolb: %hu src_lba: %llu dst_lba: %llu\n",
297 		xop->nolb, (unsigned long long)xop->src_lba,
298 		(unsigned long long)xop->dst_lba);
299 
300 	if (dc != 0) {
301 		xop->dbl = (desc[29] << 16) & 0xff;
302 		xop->dbl |= (desc[30] << 8) & 0xff;
303 		xop->dbl |= desc[31] & 0xff;
304 
305 		pr_debug("XCOPY seg desc 0x02: DC=1 w/ dbl: %u\n", xop->dbl);
306 	}
307 	return 0;
308 }
309 
310 static int target_xcopy_parse_segment_descriptors(struct se_cmd *se_cmd,
311 				struct xcopy_op *xop, unsigned char *p,
312 				unsigned int sdll)
313 {
314 	unsigned char *desc = p;
315 	unsigned int start = 0;
316 	int offset = sdll % XCOPY_SEGMENT_DESC_LEN, rc, ret = 0;
317 
318 	if (offset != 0) {
319 		pr_err("XCOPY segment descriptor list length is not"
320 			" multiple of %d\n", XCOPY_SEGMENT_DESC_LEN);
321 		return -EINVAL;
322 	}
323 
324 	while (start < sdll) {
325 		/*
326 		 * Check segment descriptor type code for block -> block
327 		 */
328 		switch (desc[0]) {
329 		case 0x02:
330 			rc = target_xcopy_parse_segdesc_02(se_cmd, xop, desc);
331 			if (rc < 0)
332 				goto out;
333 
334 			ret++;
335 			start += XCOPY_SEGMENT_DESC_LEN;
336 			desc += XCOPY_SEGMENT_DESC_LEN;
337 			break;
338 		default:
339 			pr_err("XCOPY unspported segment descriptor"
340 				"type: 0x%02x\n", desc[0]);
341 			goto out;
342 		}
343 	}
344 
345 	return ret;
346 
347 out:
348 	return -EINVAL;
349 }
350 
351 /*
352  * Start xcopy_pt ops
353  */
354 
355 struct xcopy_pt_cmd {
356 	bool remote_port;
357 	struct se_cmd se_cmd;
358 	struct xcopy_op *xcopy_op;
359 	struct completion xpt_passthrough_sem;
360 };
361 
362 static struct se_port xcopy_pt_port;
363 static struct se_portal_group xcopy_pt_tpg;
364 static struct se_session xcopy_pt_sess;
365 static struct se_node_acl xcopy_pt_nacl;
366 
367 static char *xcopy_pt_get_fabric_name(void)
368 {
369         return "xcopy-pt";
370 }
371 
372 static u32 xcopy_pt_get_tag(struct se_cmd *se_cmd)
373 {
374         return 0;
375 }
376 
377 static int xcopy_pt_get_cmd_state(struct se_cmd *se_cmd)
378 {
379         return 0;
380 }
381 
382 static void xcopy_pt_undepend_remotedev(struct xcopy_op *xop)
383 {
384 	struct configfs_subsystem *subsys = target_core_subsystem[0];
385 	struct se_device *remote_dev;
386 
387 	if (xop->op_origin == XCOL_SOURCE_RECV_OP)
388 		remote_dev = xop->dst_dev;
389 	else
390 		remote_dev = xop->src_dev;
391 
392 	pr_debug("Calling configfs_undepend_item for subsys: %p"
393 		  " remote_dev: %p remote_dev->dev_group: %p\n",
394 		  subsys, remote_dev, &remote_dev->dev_group.cg_item);
395 
396 	configfs_undepend_item(subsys, &remote_dev->dev_group.cg_item);
397 }
398 
399 static void xcopy_pt_release_cmd(struct se_cmd *se_cmd)
400 {
401 	struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,
402 				struct xcopy_pt_cmd, se_cmd);
403 
404 	if (xpt_cmd->remote_port)
405 		kfree(se_cmd->se_lun);
406 
407 	kfree(xpt_cmd);
408 }
409 
410 static int xcopy_pt_check_stop_free(struct se_cmd *se_cmd)
411 {
412 	struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,
413 				struct xcopy_pt_cmd, se_cmd);
414 
415 	complete(&xpt_cmd->xpt_passthrough_sem);
416 	return 0;
417 }
418 
419 static int xcopy_pt_write_pending(struct se_cmd *se_cmd)
420 {
421 	return 0;
422 }
423 
424 static int xcopy_pt_write_pending_status(struct se_cmd *se_cmd)
425 {
426 	return 0;
427 }
428 
429 static int xcopy_pt_queue_data_in(struct se_cmd *se_cmd)
430 {
431 	return 0;
432 }
433 
434 static int xcopy_pt_queue_status(struct se_cmd *se_cmd)
435 {
436 	return 0;
437 }
438 
439 static struct target_core_fabric_ops xcopy_pt_tfo = {
440 	.get_fabric_name	= xcopy_pt_get_fabric_name,
441 	.get_task_tag		= xcopy_pt_get_tag,
442 	.get_cmd_state		= xcopy_pt_get_cmd_state,
443 	.release_cmd		= xcopy_pt_release_cmd,
444 	.check_stop_free	= xcopy_pt_check_stop_free,
445 	.write_pending		= xcopy_pt_write_pending,
446 	.write_pending_status	= xcopy_pt_write_pending_status,
447 	.queue_data_in		= xcopy_pt_queue_data_in,
448 	.queue_status		= xcopy_pt_queue_status,
449 };
450 
451 /*
452  * End xcopy_pt_ops
453  */
454 
455 int target_xcopy_setup_pt(void)
456 {
457 	xcopy_wq = alloc_workqueue("xcopy_wq", WQ_MEM_RECLAIM, 0);
458 	if (!xcopy_wq) {
459 		pr_err("Unable to allocate xcopy_wq\n");
460 		return -ENOMEM;
461 	}
462 
463 	memset(&xcopy_pt_port, 0, sizeof(struct se_port));
464 	INIT_LIST_HEAD(&xcopy_pt_port.sep_alua_list);
465 	INIT_LIST_HEAD(&xcopy_pt_port.sep_list);
466 	mutex_init(&xcopy_pt_port.sep_tg_pt_md_mutex);
467 
468 	memset(&xcopy_pt_tpg, 0, sizeof(struct se_portal_group));
469 	INIT_LIST_HEAD(&xcopy_pt_tpg.se_tpg_node);
470 	INIT_LIST_HEAD(&xcopy_pt_tpg.acl_node_list);
471 	INIT_LIST_HEAD(&xcopy_pt_tpg.tpg_sess_list);
472 
473 	xcopy_pt_port.sep_tpg = &xcopy_pt_tpg;
474 	xcopy_pt_tpg.se_tpg_tfo = &xcopy_pt_tfo;
475 
476 	memset(&xcopy_pt_nacl, 0, sizeof(struct se_node_acl));
477 	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_list);
478 	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_sess_list);
479 	memset(&xcopy_pt_sess, 0, sizeof(struct se_session));
480 	INIT_LIST_HEAD(&xcopy_pt_sess.sess_list);
481 	INIT_LIST_HEAD(&xcopy_pt_sess.sess_acl_list);
482 
483 	xcopy_pt_nacl.se_tpg = &xcopy_pt_tpg;
484 	xcopy_pt_nacl.nacl_sess = &xcopy_pt_sess;
485 
486 	xcopy_pt_sess.se_tpg = &xcopy_pt_tpg;
487 	xcopy_pt_sess.se_node_acl = &xcopy_pt_nacl;
488 
489 	return 0;
490 }
491 
492 void target_xcopy_release_pt(void)
493 {
494 	if (xcopy_wq)
495 		destroy_workqueue(xcopy_wq);
496 }
497 
498 static void target_xcopy_setup_pt_port(
499 	struct xcopy_pt_cmd *xpt_cmd,
500 	struct xcopy_op *xop,
501 	bool remote_port)
502 {
503 	struct se_cmd *ec_cmd = xop->xop_se_cmd;
504 	struct se_cmd *pt_cmd = &xpt_cmd->se_cmd;
505 
506 	if (xop->op_origin == XCOL_SOURCE_RECV_OP) {
507 		/*
508 		 * Honor destination port reservations for X-COPY PUSH emulation
509 		 * when CDB is received on local source port, and READs blocks to
510 		 * WRITE on remote destination port.
511 		 */
512 		if (remote_port) {
513 			xpt_cmd->remote_port = remote_port;
514 			pt_cmd->se_lun->lun_sep = &xcopy_pt_port;
515 			pr_debug("Setup emulated remote DEST xcopy_pt_port: %p to"
516 				" cmd->se_lun->lun_sep for X-COPY data PUSH\n",
517 				pt_cmd->se_lun->lun_sep);
518 		} else {
519 			pt_cmd->se_lun = ec_cmd->se_lun;
520 			pt_cmd->se_dev = ec_cmd->se_dev;
521 
522 			pr_debug("Honoring local SRC port from ec_cmd->se_dev:"
523 				" %p\n", pt_cmd->se_dev);
524 			pt_cmd->se_lun = ec_cmd->se_lun;
525 			pr_debug("Honoring local SRC port from ec_cmd->se_lun: %p\n",
526 				pt_cmd->se_lun);
527 		}
528 	} else {
529 		/*
530 		 * Honor source port reservation for X-COPY PULL emulation
531 		 * when CDB is received on local desintation port, and READs
532 		 * blocks from the remote source port to WRITE on local
533 		 * destination port.
534 		 */
535 		if (remote_port) {
536 			xpt_cmd->remote_port = remote_port;
537 			pt_cmd->se_lun->lun_sep = &xcopy_pt_port;
538 			pr_debug("Setup emulated remote SRC xcopy_pt_port: %p to"
539 				" cmd->se_lun->lun_sep for X-COPY data PULL\n",
540 				pt_cmd->se_lun->lun_sep);
541 		} else {
542 			pt_cmd->se_lun = ec_cmd->se_lun;
543 			pt_cmd->se_dev = ec_cmd->se_dev;
544 
545 			pr_debug("Honoring local DST port from ec_cmd->se_dev:"
546 				" %p\n", pt_cmd->se_dev);
547 			pt_cmd->se_lun = ec_cmd->se_lun;
548 			pr_debug("Honoring local DST port from ec_cmd->se_lun: %p\n",
549 				pt_cmd->se_lun);
550 		}
551 	}
552 }
553 
554 static int target_xcopy_init_pt_lun(
555 	struct xcopy_pt_cmd *xpt_cmd,
556 	struct xcopy_op *xop,
557 	struct se_device *se_dev,
558 	struct se_cmd *pt_cmd,
559 	bool remote_port)
560 {
561 	/*
562 	 * Don't allocate + init an pt_cmd->se_lun if honoring local port for
563 	 * reservations.  The pt_cmd->se_lun pointer will be setup from within
564 	 * target_xcopy_setup_pt_port()
565 	 */
566 	if (remote_port == false) {
567 		pt_cmd->se_cmd_flags |= SCF_SE_LUN_CMD | SCF_CMD_XCOPY_PASSTHROUGH;
568 		return 0;
569 	}
570 
571 	pt_cmd->se_lun = kzalloc(sizeof(struct se_lun), GFP_KERNEL);
572 	if (!pt_cmd->se_lun) {
573 		pr_err("Unable to allocate pt_cmd->se_lun\n");
574 		return -ENOMEM;
575 	}
576 	init_completion(&pt_cmd->se_lun->lun_shutdown_comp);
577 	INIT_LIST_HEAD(&pt_cmd->se_lun->lun_cmd_list);
578 	INIT_LIST_HEAD(&pt_cmd->se_lun->lun_acl_list);
579 	spin_lock_init(&pt_cmd->se_lun->lun_acl_lock);
580 	spin_lock_init(&pt_cmd->se_lun->lun_cmd_lock);
581 	spin_lock_init(&pt_cmd->se_lun->lun_sep_lock);
582 
583 	pt_cmd->se_dev = se_dev;
584 
585 	pr_debug("Setup emulated se_dev: %p from se_dev\n", pt_cmd->se_dev);
586 	pt_cmd->se_lun->lun_se_dev = se_dev;
587 	pt_cmd->se_cmd_flags |= SCF_SE_LUN_CMD | SCF_CMD_XCOPY_PASSTHROUGH;
588 
589 	pr_debug("Setup emulated se_dev: %p to pt_cmd->se_lun->lun_se_dev\n",
590 		pt_cmd->se_lun->lun_se_dev);
591 
592 	return 0;
593 }
594 
595 static int target_xcopy_setup_pt_cmd(
596 	struct xcopy_pt_cmd *xpt_cmd,
597 	struct xcopy_op *xop,
598 	struct se_device *se_dev,
599 	unsigned char *cdb,
600 	bool remote_port,
601 	bool alloc_mem)
602 {
603 	struct se_cmd *cmd = &xpt_cmd->se_cmd;
604 	sense_reason_t sense_rc;
605 	int ret = 0, rc;
606 	/*
607 	 * Setup LUN+port to honor reservations based upon xop->op_origin for
608 	 * X-COPY PUSH or X-COPY PULL based upon where the CDB was received.
609 	 */
610 	rc = target_xcopy_init_pt_lun(xpt_cmd, xop, se_dev, cmd, remote_port);
611 	if (rc < 0) {
612 		ret = rc;
613 		goto out;
614 	}
615 	xpt_cmd->xcopy_op = xop;
616 	target_xcopy_setup_pt_port(xpt_cmd, xop, remote_port);
617 
618 	sense_rc = target_setup_cmd_from_cdb(cmd, cdb);
619 	if (sense_rc) {
620 		ret = -EINVAL;
621 		goto out;
622 	}
623 
624 	if (alloc_mem) {
625 		rc = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
626 				      cmd->data_length, false);
627 		if (rc < 0) {
628 			ret = rc;
629 			goto out;
630 		}
631 		/*
632 		 * Set this bit so that transport_free_pages() allows the
633 		 * caller to release SGLs + physical memory allocated by
634 		 * transport_generic_get_mem()..
635 		 */
636 		cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
637 	} else {
638 		/*
639 		 * Here the previously allocated SGLs for the internal READ
640 		 * are mapped zero-copy to the internal WRITE.
641 		 */
642 		sense_rc = transport_generic_map_mem_to_cmd(cmd,
643 					xop->xop_data_sg, xop->xop_data_nents,
644 					NULL, 0);
645 		if (sense_rc) {
646 			ret = -EINVAL;
647 			goto out;
648 		}
649 
650 		pr_debug("Setup PASSTHROUGH_NOALLOC t_data_sg: %p t_data_nents:"
651 			 " %u\n", cmd->t_data_sg, cmd->t_data_nents);
652 	}
653 
654 	return 0;
655 
656 out:
657 	if (remote_port == true)
658 		kfree(cmd->se_lun);
659 	return ret;
660 }
661 
662 static int target_xcopy_issue_pt_cmd(struct xcopy_pt_cmd *xpt_cmd)
663 {
664 	struct se_cmd *se_cmd = &xpt_cmd->se_cmd;
665 	sense_reason_t sense_rc;
666 
667 	sense_rc = transport_generic_new_cmd(se_cmd);
668 	if (sense_rc)
669 		return -EINVAL;
670 
671 	if (se_cmd->data_direction == DMA_TO_DEVICE)
672 		target_execute_cmd(se_cmd);
673 
674 	wait_for_completion_interruptible(&xpt_cmd->xpt_passthrough_sem);
675 
676 	pr_debug("target_xcopy_issue_pt_cmd(): SCSI status: 0x%02x\n",
677 			se_cmd->scsi_status);
678 	return 0;
679 }
680 
681 static int target_xcopy_read_source(
682 	struct se_cmd *ec_cmd,
683 	struct xcopy_op *xop,
684 	struct se_device *src_dev,
685 	sector_t src_lba,
686 	u32 src_sectors)
687 {
688 	struct xcopy_pt_cmd *xpt_cmd;
689 	struct se_cmd *se_cmd;
690 	u32 length = (src_sectors * src_dev->dev_attrib.block_size);
691 	int rc;
692 	unsigned char cdb[16];
693 	bool remote_port = (xop->op_origin == XCOL_DEST_RECV_OP);
694 
695 	xpt_cmd = kzalloc(sizeof(struct xcopy_pt_cmd), GFP_KERNEL);
696 	if (!xpt_cmd) {
697 		pr_err("Unable to allocate xcopy_pt_cmd\n");
698 		return -ENOMEM;
699 	}
700 	init_completion(&xpt_cmd->xpt_passthrough_sem);
701 	se_cmd = &xpt_cmd->se_cmd;
702 
703 	memset(&cdb[0], 0, 16);
704 	cdb[0] = READ_16;
705 	put_unaligned_be64(src_lba, &cdb[2]);
706 	put_unaligned_be32(src_sectors, &cdb[10]);
707 	pr_debug("XCOPY: Built READ_16: LBA: %llu Sectors: %u Length: %u\n",
708 		(unsigned long long)src_lba, src_sectors, length);
709 
710 	transport_init_se_cmd(se_cmd, &xcopy_pt_tfo, NULL, length,
711 				DMA_FROM_DEVICE, 0, NULL);
712 	xop->src_pt_cmd = xpt_cmd;
713 
714 	rc = target_xcopy_setup_pt_cmd(xpt_cmd, xop, src_dev, &cdb[0],
715 				remote_port, true);
716 	if (rc < 0) {
717 		transport_generic_free_cmd(se_cmd, 0);
718 		return rc;
719 	}
720 
721 	xop->xop_data_sg = se_cmd->t_data_sg;
722 	xop->xop_data_nents = se_cmd->t_data_nents;
723 	pr_debug("XCOPY-READ: Saved xop->xop_data_sg: %p, num: %u for READ"
724 		" memory\n", xop->xop_data_sg, xop->xop_data_nents);
725 
726 	rc = target_xcopy_issue_pt_cmd(xpt_cmd);
727 	if (rc < 0) {
728 		transport_generic_free_cmd(se_cmd, 0);
729 		return rc;
730 	}
731 	/*
732 	 * Clear off the allocated t_data_sg, that has been saved for
733 	 * zero-copy WRITE submission reuse in struct xcopy_op..
734 	 */
735 	se_cmd->t_data_sg = NULL;
736 	se_cmd->t_data_nents = 0;
737 
738 	return 0;
739 }
740 
741 static int target_xcopy_write_destination(
742 	struct se_cmd *ec_cmd,
743 	struct xcopy_op *xop,
744 	struct se_device *dst_dev,
745 	sector_t dst_lba,
746 	u32 dst_sectors)
747 {
748 	struct xcopy_pt_cmd *xpt_cmd;
749 	struct se_cmd *se_cmd;
750 	u32 length = (dst_sectors * dst_dev->dev_attrib.block_size);
751 	int rc;
752 	unsigned char cdb[16];
753 	bool remote_port = (xop->op_origin == XCOL_SOURCE_RECV_OP);
754 
755 	xpt_cmd = kzalloc(sizeof(struct xcopy_pt_cmd), GFP_KERNEL);
756 	if (!xpt_cmd) {
757 		pr_err("Unable to allocate xcopy_pt_cmd\n");
758 		return -ENOMEM;
759 	}
760 	init_completion(&xpt_cmd->xpt_passthrough_sem);
761 	se_cmd = &xpt_cmd->se_cmd;
762 
763 	memset(&cdb[0], 0, 16);
764 	cdb[0] = WRITE_16;
765 	put_unaligned_be64(dst_lba, &cdb[2]);
766 	put_unaligned_be32(dst_sectors, &cdb[10]);
767 	pr_debug("XCOPY: Built WRITE_16: LBA: %llu Sectors: %u Length: %u\n",
768 		(unsigned long long)dst_lba, dst_sectors, length);
769 
770 	transport_init_se_cmd(se_cmd, &xcopy_pt_tfo, NULL, length,
771 				DMA_TO_DEVICE, 0, NULL);
772 	xop->dst_pt_cmd = xpt_cmd;
773 
774 	rc = target_xcopy_setup_pt_cmd(xpt_cmd, xop, dst_dev, &cdb[0],
775 				remote_port, false);
776 	if (rc < 0) {
777 		struct se_cmd *src_cmd = &xop->src_pt_cmd->se_cmd;
778 		/*
779 		 * If the failure happened before the t_mem_list hand-off in
780 		 * target_xcopy_setup_pt_cmd(), Reset memory + clear flag so that
781 		 * core releases this memory on error during X-COPY WRITE I/O.
782 		 */
783 		src_cmd->se_cmd_flags &= ~SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
784 		src_cmd->t_data_sg = xop->xop_data_sg;
785 		src_cmd->t_data_nents = xop->xop_data_nents;
786 
787 		transport_generic_free_cmd(se_cmd, 0);
788 		return rc;
789 	}
790 
791 	rc = target_xcopy_issue_pt_cmd(xpt_cmd);
792 	if (rc < 0) {
793 		se_cmd->se_cmd_flags &= ~SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
794 		transport_generic_free_cmd(se_cmd, 0);
795 		return rc;
796 	}
797 
798 	return 0;
799 }
800 
801 static void target_xcopy_do_work(struct work_struct *work)
802 {
803 	struct xcopy_op *xop = container_of(work, struct xcopy_op, xop_work);
804 	struct se_device *src_dev = xop->src_dev, *dst_dev = xop->dst_dev;
805 	struct se_cmd *ec_cmd = xop->xop_se_cmd;
806 	sector_t src_lba = xop->src_lba, dst_lba = xop->dst_lba, end_lba;
807 	unsigned int max_sectors;
808 	int rc;
809 	unsigned short nolb = xop->nolb, cur_nolb, max_nolb, copied_nolb = 0;
810 
811 	end_lba = src_lba + nolb;
812 	/*
813 	 * Break up XCOPY I/O into hw_max_sectors sized I/O based on the
814 	 * smallest max_sectors between src_dev + dev_dev, or
815 	 */
816 	max_sectors = min(src_dev->dev_attrib.hw_max_sectors,
817 			  dst_dev->dev_attrib.hw_max_sectors);
818 	max_sectors = min_t(u32, max_sectors, XCOPY_MAX_SECTORS);
819 
820 	max_nolb = min_t(u16, max_sectors, ((u16)(~0U)));
821 
822 	pr_debug("target_xcopy_do_work: nolb: %hu, max_nolb: %hu end_lba: %llu\n",
823 			nolb, max_nolb, (unsigned long long)end_lba);
824 	pr_debug("target_xcopy_do_work: Starting src_lba: %llu, dst_lba: %llu\n",
825 			(unsigned long long)src_lba, (unsigned long long)dst_lba);
826 
827 	while (src_lba < end_lba) {
828 		cur_nolb = min(nolb, max_nolb);
829 
830 		pr_debug("target_xcopy_do_work: Calling read src_dev: %p src_lba: %llu,"
831 			" cur_nolb: %hu\n", src_dev, (unsigned long long)src_lba, cur_nolb);
832 
833 		rc = target_xcopy_read_source(ec_cmd, xop, src_dev, src_lba, cur_nolb);
834 		if (rc < 0)
835 			goto out;
836 
837 		src_lba += cur_nolb;
838 		pr_debug("target_xcopy_do_work: Incremented READ src_lba to %llu\n",
839 				(unsigned long long)src_lba);
840 
841 		pr_debug("target_xcopy_do_work: Calling write dst_dev: %p dst_lba: %llu,"
842 			" cur_nolb: %hu\n", dst_dev, (unsigned long long)dst_lba, cur_nolb);
843 
844 		rc = target_xcopy_write_destination(ec_cmd, xop, dst_dev,
845 						dst_lba, cur_nolb);
846 		if (rc < 0) {
847 			transport_generic_free_cmd(&xop->src_pt_cmd->se_cmd, 0);
848 			goto out;
849 		}
850 
851 		dst_lba += cur_nolb;
852 		pr_debug("target_xcopy_do_work: Incremented WRITE dst_lba to %llu\n",
853 				(unsigned long long)dst_lba);
854 
855 		copied_nolb += cur_nolb;
856 		nolb -= cur_nolb;
857 
858 		transport_generic_free_cmd(&xop->src_pt_cmd->se_cmd, 0);
859 		xop->dst_pt_cmd->se_cmd.se_cmd_flags &= ~SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
860 
861 		transport_generic_free_cmd(&xop->dst_pt_cmd->se_cmd, 0);
862 	}
863 
864 	xcopy_pt_undepend_remotedev(xop);
865 	kfree(xop);
866 
867 	pr_debug("target_xcopy_do_work: Final src_lba: %llu, dst_lba: %llu\n",
868 		(unsigned long long)src_lba, (unsigned long long)dst_lba);
869 	pr_debug("target_xcopy_do_work: Blocks copied: %hu, Bytes Copied: %u\n",
870 		copied_nolb, copied_nolb * dst_dev->dev_attrib.block_size);
871 
872 	pr_debug("target_xcopy_do_work: Setting X-COPY GOOD status -> sending response\n");
873 	target_complete_cmd(ec_cmd, SAM_STAT_GOOD);
874 	return;
875 
876 out:
877 	xcopy_pt_undepend_remotedev(xop);
878 	kfree(xop);
879 
880 	pr_warn("target_xcopy_do_work: Setting X-COPY CHECK_CONDITION -> sending response\n");
881 	ec_cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
882 	target_complete_cmd(ec_cmd, SAM_STAT_CHECK_CONDITION);
883 }
884 
885 sense_reason_t target_do_xcopy(struct se_cmd *se_cmd)
886 {
887 	struct xcopy_op *xop = NULL;
888 	unsigned char *p = NULL, *seg_desc;
889 	unsigned int list_id, list_id_usage, sdll, inline_dl, sa;
890 	int rc;
891 	unsigned short tdll;
892 
893 	sa = se_cmd->t_task_cdb[1] & 0x1f;
894 	if (sa != 0x00) {
895 		pr_err("EXTENDED_COPY(LID4) not supported\n");
896 		return TCM_UNSUPPORTED_SCSI_OPCODE;
897 	}
898 
899 	p = transport_kmap_data_sg(se_cmd);
900 	if (!p) {
901 		pr_err("transport_kmap_data_sg() failed in target_do_xcopy\n");
902 		return TCM_OUT_OF_RESOURCES;
903 	}
904 
905 	list_id = p[0];
906 	if (list_id != 0x00) {
907 		pr_err("XCOPY with non zero list_id: 0x%02x\n", list_id);
908 		goto out;
909 	}
910 	list_id_usage = (p[1] & 0x18);
911 	/*
912 	 * Determine TARGET DESCRIPTOR LIST LENGTH + SEGMENT DESCRIPTOR LIST LENGTH
913 	 */
914 	tdll = get_unaligned_be16(&p[2]);
915 	sdll = get_unaligned_be32(&p[8]);
916 
917 	inline_dl = get_unaligned_be32(&p[12]);
918 	if (inline_dl != 0) {
919 		pr_err("XCOPY with non zero inline data length\n");
920 		goto out;
921 	}
922 
923 	xop = kzalloc(sizeof(struct xcopy_op), GFP_KERNEL);
924 	if (!xop) {
925 		pr_err("Unable to allocate xcopy_op\n");
926 		goto out;
927 	}
928 	xop->xop_se_cmd = se_cmd;
929 
930 	pr_debug("Processing XCOPY with list_id: 0x%02x list_id_usage: 0x%02x"
931 		" tdll: %hu sdll: %u inline_dl: %u\n", list_id, list_id_usage,
932 		tdll, sdll, inline_dl);
933 
934 	rc = target_xcopy_parse_target_descriptors(se_cmd, xop, &p[16], tdll);
935 	if (rc <= 0)
936 		goto out;
937 
938 	pr_debug("XCOPY: Processed %d target descriptors, length: %u\n", rc,
939 				rc * XCOPY_TARGET_DESC_LEN);
940 	seg_desc = &p[16];
941 	seg_desc += (rc * XCOPY_TARGET_DESC_LEN);
942 
943 	rc = target_xcopy_parse_segment_descriptors(se_cmd, xop, seg_desc, sdll);
944 	if (rc <= 0) {
945 		xcopy_pt_undepend_remotedev(xop);
946 		goto out;
947 	}
948 	transport_kunmap_data_sg(se_cmd);
949 
950 	pr_debug("XCOPY: Processed %d segment descriptors, length: %u\n", rc,
951 				rc * XCOPY_SEGMENT_DESC_LEN);
952 	INIT_WORK(&xop->xop_work, target_xcopy_do_work);
953 	queue_work(xcopy_wq, &xop->xop_work);
954 	return TCM_NO_SENSE;
955 
956 out:
957 	if (p)
958 		transport_kunmap_data_sg(se_cmd);
959 	kfree(xop);
960 	return TCM_INVALID_CDB_FIELD;
961 }
962 
963 static sense_reason_t target_rcr_operating_parameters(struct se_cmd *se_cmd)
964 {
965 	unsigned char *p;
966 
967 	p = transport_kmap_data_sg(se_cmd);
968 	if (!p) {
969 		pr_err("transport_kmap_data_sg failed in"
970 		       " target_rcr_operating_parameters\n");
971 		return TCM_OUT_OF_RESOURCES;
972 	}
973 
974 	if (se_cmd->data_length < 54) {
975 		pr_err("Receive Copy Results Op Parameters length"
976 		       " too small: %u\n", se_cmd->data_length);
977 		transport_kunmap_data_sg(se_cmd);
978 		return TCM_INVALID_CDB_FIELD;
979 	}
980 	/*
981 	 * Set SNLID=1 (Supports no List ID)
982 	 */
983 	p[4] = 0x1;
984 	/*
985 	 * MAXIMUM TARGET DESCRIPTOR COUNT
986 	 */
987 	put_unaligned_be16(RCR_OP_MAX_TARGET_DESC_COUNT, &p[8]);
988 	/*
989 	 * MAXIMUM SEGMENT DESCRIPTOR COUNT
990 	 */
991 	put_unaligned_be16(RCR_OP_MAX_SG_DESC_COUNT, &p[10]);
992 	/*
993 	 * MAXIMUM DESCRIPTOR LIST LENGTH
994 	 */
995 	put_unaligned_be32(RCR_OP_MAX_DESC_LIST_LEN, &p[12]);
996 	/*
997 	 * MAXIMUM SEGMENT LENGTH
998 	 */
999 	put_unaligned_be32(RCR_OP_MAX_SEGMENT_LEN, &p[16]);
1000 	/*
1001 	 * MAXIMUM INLINE DATA LENGTH for SA 0x04 (NOT SUPPORTED)
1002 	 */
1003 	put_unaligned_be32(0x0, &p[20]);
1004 	/*
1005 	 * HELD DATA LIMIT
1006 	 */
1007 	put_unaligned_be32(0x0, &p[24]);
1008 	/*
1009 	 * MAXIMUM STREAM DEVICE TRANSFER SIZE
1010 	 */
1011 	put_unaligned_be32(0x0, &p[28]);
1012 	/*
1013 	 * TOTAL CONCURRENT COPIES
1014 	 */
1015 	put_unaligned_be16(RCR_OP_TOTAL_CONCURR_COPIES, &p[34]);
1016 	/*
1017 	 * MAXIMUM CONCURRENT COPIES
1018 	 */
1019 	p[36] = RCR_OP_MAX_CONCURR_COPIES;
1020 	/*
1021 	 * DATA SEGMENT GRANULARITY (log 2)
1022 	 */
1023 	p[37] = RCR_OP_DATA_SEG_GRAN_LOG2;
1024 	/*
1025 	 * INLINE DATA GRANULARITY log 2)
1026 	 */
1027 	p[38] = RCR_OP_INLINE_DATA_GRAN_LOG2;
1028 	/*
1029 	 * HELD DATA GRANULARITY
1030 	 */
1031 	p[39] = RCR_OP_HELD_DATA_GRAN_LOG2;
1032 	/*
1033 	 * IMPLEMENTED DESCRIPTOR LIST LENGTH
1034 	 */
1035 	p[43] = 0x2;
1036 	/*
1037 	 * List of implemented descriptor type codes (ordered)
1038 	 */
1039 	p[44] = 0x02; /* Copy Block to Block device */
1040 	p[45] = 0xe4; /* Identification descriptor target descriptor */
1041 
1042 	/*
1043 	 * AVAILABLE DATA (n-3)
1044 	 */
1045 	put_unaligned_be32(42, &p[0]);
1046 
1047 	transport_kunmap_data_sg(se_cmd);
1048 	target_complete_cmd(se_cmd, GOOD);
1049 
1050 	return TCM_NO_SENSE;
1051 }
1052 
1053 sense_reason_t target_do_receive_copy_results(struct se_cmd *se_cmd)
1054 {
1055 	unsigned char *cdb = &se_cmd->t_task_cdb[0];
1056 	int sa = (cdb[1] & 0x1f), list_id = cdb[2];
1057 	sense_reason_t rc = TCM_NO_SENSE;
1058 
1059 	pr_debug("Entering target_do_receive_copy_results: SA: 0x%02x, List ID:"
1060 		" 0x%02x, AL: %u\n", sa, list_id, se_cmd->data_length);
1061 
1062 	if (list_id != 0) {
1063 		pr_err("Receive Copy Results with non zero list identifier"
1064 		       " not supported\n");
1065 		return TCM_INVALID_CDB_FIELD;
1066 	}
1067 
1068 	switch (sa) {
1069 	case RCR_SA_OPERATING_PARAMETERS:
1070 		rc = target_rcr_operating_parameters(se_cmd);
1071 		break;
1072 	case RCR_SA_COPY_STATUS:
1073 	case RCR_SA_RECEIVE_DATA:
1074 	case RCR_SA_FAILED_SEGMENT_DETAILS:
1075 	default:
1076 		pr_err("Unsupported SA for receive copy results: 0x%02x\n", sa);
1077 		return TCM_INVALID_CDB_FIELD;
1078 	}
1079 
1080 	return rc;
1081 }
1082