1 /*******************************************************************************
2  * Filename: target_core_xcopy.c
3  *
4  * This file contains support for SPC-4 Extended-Copy offload with generic
5  * TCM backends.
6  *
7  * Copyright (c) 2011-2013 Datera, Inc. All rights reserved.
8  *
9  * Author:
10  * Nicholas A. Bellinger <nab@daterainc.com>
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation; either version 2 of the License, or
15  * (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  *
22  ******************************************************************************/
23 
24 #include <linux/slab.h>
25 #include <linux/spinlock.h>
26 #include <linux/list.h>
27 #include <linux/configfs.h>
28 #include <scsi/scsi.h>
29 #include <scsi/scsi_cmnd.h>
30 #include <asm/unaligned.h>
31 
32 #include <target/target_core_base.h>
33 #include <target/target_core_backend.h>
34 #include <target/target_core_fabric.h>
35 #include <target/target_core_configfs.h>
36 
37 #include "target_core_internal.h"
38 #include "target_core_pr.h"
39 #include "target_core_ua.h"
40 #include "target_core_xcopy.h"
41 
42 static struct workqueue_struct *xcopy_wq = NULL;
43 
44 static int target_xcopy_gen_naa_ieee(struct se_device *dev, unsigned char *buf)
45 {
46 	int off = 0;
47 
48 	buf[off++] = (0x6 << 4);
49 	buf[off++] = 0x01;
50 	buf[off++] = 0x40;
51 	buf[off] = (0x5 << 4);
52 
53 	spc_parse_naa_6h_vendor_specific(dev, &buf[off]);
54 	return 0;
55 }
56 
57 static int target_xcopy_locate_se_dev_e4(struct se_cmd *se_cmd, struct xcopy_op *xop,
58 					bool src)
59 {
60 	struct se_device *se_dev;
61 	struct configfs_subsystem *subsys = target_core_subsystem[0];
62 	unsigned char tmp_dev_wwn[XCOPY_NAA_IEEE_REGEX_LEN], *dev_wwn;
63 	int rc;
64 
65 	if (src)
66 		dev_wwn = &xop->dst_tid_wwn[0];
67 	else
68 		dev_wwn = &xop->src_tid_wwn[0];
69 
70 	mutex_lock(&g_device_mutex);
71 	list_for_each_entry(se_dev, &g_device_list, g_dev_node) {
72 
73 		if (!se_dev->dev_attrib.emulate_3pc)
74 			continue;
75 
76 		memset(&tmp_dev_wwn[0], 0, XCOPY_NAA_IEEE_REGEX_LEN);
77 		target_xcopy_gen_naa_ieee(se_dev, &tmp_dev_wwn[0]);
78 
79 		rc = memcmp(&tmp_dev_wwn[0], dev_wwn, XCOPY_NAA_IEEE_REGEX_LEN);
80 		if (rc != 0)
81 			continue;
82 
83 		if (src) {
84 			xop->dst_dev = se_dev;
85 			pr_debug("XCOPY 0xe4: Setting xop->dst_dev: %p from located"
86 				" se_dev\n", xop->dst_dev);
87 		} else {
88 			xop->src_dev = se_dev;
89 			pr_debug("XCOPY 0xe4: Setting xop->src_dev: %p from located"
90 				" se_dev\n", xop->src_dev);
91 		}
92 
93 		rc = configfs_depend_item(subsys,
94 				&se_dev->dev_group.cg_item);
95 		if (rc != 0) {
96 			pr_err("configfs_depend_item attempt failed:"
97 				" %d for se_dev: %p\n", rc, se_dev);
98 			mutex_unlock(&g_device_mutex);
99 			return rc;
100 		}
101 
102 		pr_debug("Called configfs_depend_item for subsys: %p se_dev: %p"
103 			" se_dev->se_dev_group: %p\n", subsys, se_dev,
104 			&se_dev->dev_group);
105 
106 		mutex_unlock(&g_device_mutex);
107 		return 0;
108 	}
109 	mutex_unlock(&g_device_mutex);
110 
111 	pr_err("Unable to locate 0xe4 descriptor for EXTENDED_COPY\n");
112 	return -EINVAL;
113 }
114 
115 static int target_xcopy_parse_tiddesc_e4(struct se_cmd *se_cmd, struct xcopy_op *xop,
116 				unsigned char *p, bool src)
117 {
118 	unsigned char *desc = p;
119 	unsigned short ript;
120 	u8 desig_len;
121 	/*
122 	 * Extract RELATIVE INITIATOR PORT IDENTIFIER
123 	 */
124 	ript = get_unaligned_be16(&desc[2]);
125 	pr_debug("XCOPY 0xe4: RELATIVE INITIATOR PORT IDENTIFIER: %hu\n", ript);
126 	/*
127 	 * Check for supported code set, association, and designator type
128 	 */
129 	if ((desc[4] & 0x0f) != 0x1) {
130 		pr_err("XCOPY 0xe4: code set of non binary type not supported\n");
131 		return -EINVAL;
132 	}
133 	if ((desc[5] & 0x30) != 0x00) {
134 		pr_err("XCOPY 0xe4: association other than LUN not supported\n");
135 		return -EINVAL;
136 	}
137 	if ((desc[5] & 0x0f) != 0x3) {
138 		pr_err("XCOPY 0xe4: designator type unsupported: 0x%02x\n",
139 				(desc[5] & 0x0f));
140 		return -EINVAL;
141 	}
142 	/*
143 	 * Check for matching 16 byte length for NAA IEEE Registered Extended
144 	 * Assigned designator
145 	 */
146 	desig_len = desc[7];
147 	if (desig_len != 16) {
148 		pr_err("XCOPY 0xe4: invalid desig_len: %d\n", (int)desig_len);
149 		return -EINVAL;
150 	}
151 	pr_debug("XCOPY 0xe4: desig_len: %d\n", (int)desig_len);
152 	/*
153 	 * Check for NAA IEEE Registered Extended Assigned header..
154 	 */
155 	if ((desc[8] & 0xf0) != 0x60) {
156 		pr_err("XCOPY 0xe4: Unsupported DESIGNATOR TYPE: 0x%02x\n",
157 					(desc[8] & 0xf0));
158 		return -EINVAL;
159 	}
160 
161 	if (src) {
162 		memcpy(&xop->src_tid_wwn[0], &desc[8], XCOPY_NAA_IEEE_REGEX_LEN);
163 		/*
164 		 * Determine if the source designator matches the local device
165 		 */
166 		if (!memcmp(&xop->local_dev_wwn[0], &xop->src_tid_wwn[0],
167 				XCOPY_NAA_IEEE_REGEX_LEN)) {
168 			xop->op_origin = XCOL_SOURCE_RECV_OP;
169 			xop->src_dev = se_cmd->se_dev;
170 			pr_debug("XCOPY 0xe4: Set xop->src_dev %p from source"
171 					" received xop\n", xop->src_dev);
172 		}
173 	} else {
174 		memcpy(&xop->dst_tid_wwn[0], &desc[8], XCOPY_NAA_IEEE_REGEX_LEN);
175 		/*
176 		 * Determine if the destination designator matches the local device
177 		 */
178 		if (!memcmp(&xop->local_dev_wwn[0], &xop->dst_tid_wwn[0],
179 				XCOPY_NAA_IEEE_REGEX_LEN)) {
180 			xop->op_origin = XCOL_DEST_RECV_OP;
181 			xop->dst_dev = se_cmd->se_dev;
182 			pr_debug("XCOPY 0xe4: Set xop->dst_dev: %p from destination"
183 				" received xop\n", xop->dst_dev);
184 		}
185 	}
186 
187 	return 0;
188 }
189 
190 static int target_xcopy_parse_target_descriptors(struct se_cmd *se_cmd,
191 				struct xcopy_op *xop, unsigned char *p,
192 				unsigned short tdll)
193 {
194 	struct se_device *local_dev = se_cmd->se_dev;
195 	unsigned char *desc = p;
196 	int offset = tdll % XCOPY_TARGET_DESC_LEN, rc, ret = 0;
197 	unsigned short start = 0;
198 	bool src = true;
199 
200 	if (offset != 0) {
201 		pr_err("XCOPY target descriptor list length is not"
202 			" multiple of %d\n", XCOPY_TARGET_DESC_LEN);
203 		return -EINVAL;
204 	}
205 	if (tdll > 64) {
206 		pr_err("XCOPY target descriptor supports a maximum"
207 			" two src/dest descriptors, tdll: %hu too large..\n", tdll);
208 		return -EINVAL;
209 	}
210 	/*
211 	 * Generate an IEEE Registered Extended designator based upon the
212 	 * se_device the XCOPY was received upon..
213 	 */
214 	memset(&xop->local_dev_wwn[0], 0, XCOPY_NAA_IEEE_REGEX_LEN);
215 	target_xcopy_gen_naa_ieee(local_dev, &xop->local_dev_wwn[0]);
216 
217 	while (start < tdll) {
218 		/*
219 		 * Check target descriptor identification with 0xE4 type with
220 		 * use VPD 0x83 WWPN matching ..
221 		 */
222 		switch (desc[0]) {
223 		case 0xe4:
224 			rc = target_xcopy_parse_tiddesc_e4(se_cmd, xop,
225 							&desc[0], src);
226 			if (rc != 0)
227 				goto out;
228 			/*
229 			 * Assume target descriptors are in source -> destination order..
230 			 */
231 			if (src)
232 				src = false;
233 			else
234 				src = true;
235 			start += XCOPY_TARGET_DESC_LEN;
236 			desc += XCOPY_TARGET_DESC_LEN;
237 			ret++;
238 			break;
239 		default:
240 			pr_err("XCOPY unsupported descriptor type code:"
241 					" 0x%02x\n", desc[0]);
242 			goto out;
243 		}
244 	}
245 
246 	if (xop->op_origin == XCOL_SOURCE_RECV_OP)
247 		rc = target_xcopy_locate_se_dev_e4(se_cmd, xop, true);
248 	else
249 		rc = target_xcopy_locate_se_dev_e4(se_cmd, xop, false);
250 
251 	if (rc < 0)
252 		goto out;
253 
254 	pr_debug("XCOPY TGT desc: Source dev: %p NAA IEEE WWN: 0x%16phN\n",
255 		 xop->src_dev, &xop->src_tid_wwn[0]);
256 	pr_debug("XCOPY TGT desc: Dest dev: %p NAA IEEE WWN: 0x%16phN\n",
257 		 xop->dst_dev, &xop->dst_tid_wwn[0]);
258 
259 	return ret;
260 
261 out:
262 	return -EINVAL;
263 }
264 
265 static int target_xcopy_parse_segdesc_02(struct se_cmd *se_cmd, struct xcopy_op *xop,
266 					unsigned char *p)
267 {
268 	unsigned char *desc = p;
269 	int dc = (desc[1] & 0x02);
270 	unsigned short desc_len;
271 
272 	desc_len = get_unaligned_be16(&desc[2]);
273 	if (desc_len != 0x18) {
274 		pr_err("XCOPY segment desc 0x02: Illegal desc_len:"
275 				" %hu\n", desc_len);
276 		return -EINVAL;
277 	}
278 
279 	xop->stdi = get_unaligned_be16(&desc[4]);
280 	xop->dtdi = get_unaligned_be16(&desc[6]);
281 	pr_debug("XCOPY seg desc 0x02: desc_len: %hu stdi: %hu dtdi: %hu, DC: %d\n",
282 		desc_len, xop->stdi, xop->dtdi, dc);
283 
284 	xop->nolb = get_unaligned_be16(&desc[10]);
285 	xop->src_lba = get_unaligned_be64(&desc[12]);
286 	xop->dst_lba = get_unaligned_be64(&desc[20]);
287 	pr_debug("XCOPY seg desc 0x02: nolb: %hu src_lba: %llu dst_lba: %llu\n",
288 		xop->nolb, (unsigned long long)xop->src_lba,
289 		(unsigned long long)xop->dst_lba);
290 
291 	if (dc != 0) {
292 		xop->dbl = (desc[29] & 0xff) << 16;
293 		xop->dbl |= (desc[30] & 0xff) << 8;
294 		xop->dbl |= desc[31] & 0xff;
295 
296 		pr_debug("XCOPY seg desc 0x02: DC=1 w/ dbl: %u\n", xop->dbl);
297 	}
298 	return 0;
299 }
300 
301 static int target_xcopy_parse_segment_descriptors(struct se_cmd *se_cmd,
302 				struct xcopy_op *xop, unsigned char *p,
303 				unsigned int sdll)
304 {
305 	unsigned char *desc = p;
306 	unsigned int start = 0;
307 	int offset = sdll % XCOPY_SEGMENT_DESC_LEN, rc, ret = 0;
308 
309 	if (offset != 0) {
310 		pr_err("XCOPY segment descriptor list length is not"
311 			" multiple of %d\n", XCOPY_SEGMENT_DESC_LEN);
312 		return -EINVAL;
313 	}
314 
315 	while (start < sdll) {
316 		/*
317 		 * Check segment descriptor type code for block -> block
318 		 */
319 		switch (desc[0]) {
320 		case 0x02:
321 			rc = target_xcopy_parse_segdesc_02(se_cmd, xop, desc);
322 			if (rc < 0)
323 				goto out;
324 
325 			ret++;
326 			start += XCOPY_SEGMENT_DESC_LEN;
327 			desc += XCOPY_SEGMENT_DESC_LEN;
328 			break;
329 		default:
330 			pr_err("XCOPY unsupported segment descriptor"
331 				"type: 0x%02x\n", desc[0]);
332 			goto out;
333 		}
334 	}
335 
336 	return ret;
337 
338 out:
339 	return -EINVAL;
340 }
341 
342 /*
343  * Start xcopy_pt ops
344  */
345 
346 struct xcopy_pt_cmd {
347 	bool remote_port;
348 	struct se_cmd se_cmd;
349 	struct xcopy_op *xcopy_op;
350 	struct completion xpt_passthrough_sem;
351 	unsigned char sense_buffer[TRANSPORT_SENSE_BUFFER];
352 };
353 
354 static struct se_port xcopy_pt_port;
355 static struct se_portal_group xcopy_pt_tpg;
356 static struct se_session xcopy_pt_sess;
357 static struct se_node_acl xcopy_pt_nacl;
358 
359 static char *xcopy_pt_get_fabric_name(void)
360 {
361         return "xcopy-pt";
362 }
363 
364 static u32 xcopy_pt_get_tag(struct se_cmd *se_cmd)
365 {
366         return 0;
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 configfs_subsystem *subsys = target_core_subsystem[0];
377 	struct se_device *remote_dev;
378 
379 	if (xop->op_origin == XCOL_SOURCE_RECV_OP)
380 		remote_dev = xop->dst_dev;
381 	else
382 		remote_dev = xop->src_dev;
383 
384 	pr_debug("Calling configfs_undepend_item for subsys: %p"
385 		  " remote_dev: %p remote_dev->dev_group: %p\n",
386 		  subsys, remote_dev, &remote_dev->dev_group.cg_item);
387 
388 	configfs_undepend_item(subsys, &remote_dev->dev_group.cg_item);
389 }
390 
391 static void xcopy_pt_release_cmd(struct se_cmd *se_cmd)
392 {
393 	struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,
394 				struct xcopy_pt_cmd, se_cmd);
395 
396 	kfree(xpt_cmd);
397 }
398 
399 static int xcopy_pt_check_stop_free(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 	complete(&xpt_cmd->xpt_passthrough_sem);
405 	return 0;
406 }
407 
408 static int xcopy_pt_write_pending(struct se_cmd *se_cmd)
409 {
410 	return 0;
411 }
412 
413 static int xcopy_pt_write_pending_status(struct se_cmd *se_cmd)
414 {
415 	return 0;
416 }
417 
418 static int xcopy_pt_queue_data_in(struct se_cmd *se_cmd)
419 {
420 	return 0;
421 }
422 
423 static int xcopy_pt_queue_status(struct se_cmd *se_cmd)
424 {
425 	return 0;
426 }
427 
428 static const struct target_core_fabric_ops xcopy_pt_tfo = {
429 	.get_fabric_name	= xcopy_pt_get_fabric_name,
430 	.get_task_tag		= xcopy_pt_get_tag,
431 	.get_cmd_state		= xcopy_pt_get_cmd_state,
432 	.release_cmd		= xcopy_pt_release_cmd,
433 	.check_stop_free	= xcopy_pt_check_stop_free,
434 	.write_pending		= xcopy_pt_write_pending,
435 	.write_pending_status	= xcopy_pt_write_pending_status,
436 	.queue_data_in		= xcopy_pt_queue_data_in,
437 	.queue_status		= xcopy_pt_queue_status,
438 };
439 
440 /*
441  * End xcopy_pt_ops
442  */
443 
444 int target_xcopy_setup_pt(void)
445 {
446 	xcopy_wq = alloc_workqueue("xcopy_wq", WQ_MEM_RECLAIM, 0);
447 	if (!xcopy_wq) {
448 		pr_err("Unable to allocate xcopy_wq\n");
449 		return -ENOMEM;
450 	}
451 
452 	memset(&xcopy_pt_port, 0, sizeof(struct se_port));
453 	INIT_LIST_HEAD(&xcopy_pt_port.sep_alua_list);
454 	INIT_LIST_HEAD(&xcopy_pt_port.sep_list);
455 	mutex_init(&xcopy_pt_port.sep_tg_pt_md_mutex);
456 
457 	memset(&xcopy_pt_tpg, 0, sizeof(struct se_portal_group));
458 	INIT_LIST_HEAD(&xcopy_pt_tpg.se_tpg_node);
459 	INIT_LIST_HEAD(&xcopy_pt_tpg.acl_node_list);
460 	INIT_LIST_HEAD(&xcopy_pt_tpg.tpg_sess_list);
461 
462 	xcopy_pt_port.sep_tpg = &xcopy_pt_tpg;
463 	xcopy_pt_tpg.se_tpg_tfo = &xcopy_pt_tfo;
464 
465 	memset(&xcopy_pt_nacl, 0, sizeof(struct se_node_acl));
466 	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_list);
467 	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_sess_list);
468 	memset(&xcopy_pt_sess, 0, sizeof(struct se_session));
469 	INIT_LIST_HEAD(&xcopy_pt_sess.sess_list);
470 	INIT_LIST_HEAD(&xcopy_pt_sess.sess_acl_list);
471 
472 	xcopy_pt_nacl.se_tpg = &xcopy_pt_tpg;
473 	xcopy_pt_nacl.nacl_sess = &xcopy_pt_sess;
474 
475 	xcopy_pt_sess.se_tpg = &xcopy_pt_tpg;
476 	xcopy_pt_sess.se_node_acl = &xcopy_pt_nacl;
477 
478 	return 0;
479 }
480 
481 void target_xcopy_release_pt(void)
482 {
483 	if (xcopy_wq)
484 		destroy_workqueue(xcopy_wq);
485 }
486 
487 static void target_xcopy_setup_pt_port(
488 	struct xcopy_pt_cmd *xpt_cmd,
489 	struct xcopy_op *xop,
490 	bool remote_port)
491 {
492 	struct se_cmd *ec_cmd = xop->xop_se_cmd;
493 	struct se_cmd *pt_cmd = &xpt_cmd->se_cmd;
494 
495 	if (xop->op_origin == XCOL_SOURCE_RECV_OP) {
496 		/*
497 		 * Honor destination port reservations for X-COPY PUSH emulation
498 		 * when CDB is received on local source port, and READs blocks to
499 		 * WRITE on remote destination port.
500 		 */
501 		if (remote_port) {
502 			xpt_cmd->remote_port = remote_port;
503 			pt_cmd->se_lun->lun_sep = &xcopy_pt_port;
504 			pr_debug("Setup emulated remote DEST xcopy_pt_port: %p to"
505 				" cmd->se_lun->lun_sep for X-COPY data PUSH\n",
506 				pt_cmd->se_lun->lun_sep);
507 		} else {
508 			pt_cmd->se_lun = ec_cmd->se_lun;
509 			pt_cmd->se_dev = ec_cmd->se_dev;
510 
511 			pr_debug("Honoring local SRC port from ec_cmd->se_dev:"
512 				" %p\n", pt_cmd->se_dev);
513 			pt_cmd->se_lun = ec_cmd->se_lun;
514 			pr_debug("Honoring local SRC port from ec_cmd->se_lun: %p\n",
515 				pt_cmd->se_lun);
516 		}
517 	} else {
518 		/*
519 		 * Honor source port reservation for X-COPY PULL emulation
520 		 * when CDB is received on local desintation port, and READs
521 		 * blocks from the remote source port to WRITE on local
522 		 * destination port.
523 		 */
524 		if (remote_port) {
525 			xpt_cmd->remote_port = remote_port;
526 			pt_cmd->se_lun->lun_sep = &xcopy_pt_port;
527 			pr_debug("Setup emulated remote SRC xcopy_pt_port: %p to"
528 				" cmd->se_lun->lun_sep for X-COPY data PULL\n",
529 				pt_cmd->se_lun->lun_sep);
530 		} else {
531 			pt_cmd->se_lun = ec_cmd->se_lun;
532 			pt_cmd->se_dev = ec_cmd->se_dev;
533 
534 			pr_debug("Honoring local DST port from ec_cmd->se_dev:"
535 				" %p\n", pt_cmd->se_dev);
536 			pt_cmd->se_lun = ec_cmd->se_lun;
537 			pr_debug("Honoring local DST port from ec_cmd->se_lun: %p\n",
538 				pt_cmd->se_lun);
539 		}
540 	}
541 }
542 
543 static void target_xcopy_init_pt_lun(struct se_device *se_dev,
544 		struct se_cmd *pt_cmd, bool remote_port)
545 {
546 	/*
547 	 * Don't allocate + init an pt_cmd->se_lun if honoring local port for
548 	 * reservations.  The pt_cmd->se_lun pointer will be setup from within
549 	 * target_xcopy_setup_pt_port()
550 	 */
551 	if (remote_port) {
552 		pr_debug("Setup emulated se_dev: %p from se_dev\n",
553 			pt_cmd->se_dev);
554 		pt_cmd->se_lun = &se_dev->xcopy_lun;
555 		pt_cmd->se_dev = se_dev;
556 	}
557 
558 	pt_cmd->se_cmd_flags |= SCF_SE_LUN_CMD;
559 }
560 
561 static int target_xcopy_setup_pt_cmd(
562 	struct xcopy_pt_cmd *xpt_cmd,
563 	struct xcopy_op *xop,
564 	struct se_device *se_dev,
565 	unsigned char *cdb,
566 	bool remote_port,
567 	bool alloc_mem)
568 {
569 	struct se_cmd *cmd = &xpt_cmd->se_cmd;
570 	sense_reason_t sense_rc;
571 	int ret = 0, rc;
572 	/*
573 	 * Setup LUN+port to honor reservations based upon xop->op_origin for
574 	 * X-COPY PUSH or X-COPY PULL based upon where the CDB was received.
575 	 */
576 	target_xcopy_init_pt_lun(se_dev, cmd, remote_port);
577 
578 	xpt_cmd->xcopy_op = xop;
579 	target_xcopy_setup_pt_port(xpt_cmd, xop, remote_port);
580 
581 	sense_rc = target_setup_cmd_from_cdb(cmd, cdb);
582 	if (sense_rc) {
583 		ret = -EINVAL;
584 		goto out;
585 	}
586 
587 	if (alloc_mem) {
588 		rc = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
589 				      cmd->data_length, false);
590 		if (rc < 0) {
591 			ret = rc;
592 			goto out;
593 		}
594 		/*
595 		 * Set this bit so that transport_free_pages() allows the
596 		 * caller to release SGLs + physical memory allocated by
597 		 * transport_generic_get_mem()..
598 		 */
599 		cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
600 	} else {
601 		/*
602 		 * Here the previously allocated SGLs for the internal READ
603 		 * are mapped zero-copy to the internal WRITE.
604 		 */
605 		sense_rc = transport_generic_map_mem_to_cmd(cmd,
606 					xop->xop_data_sg, xop->xop_data_nents,
607 					NULL, 0);
608 		if (sense_rc) {
609 			ret = -EINVAL;
610 			goto out;
611 		}
612 
613 		pr_debug("Setup PASSTHROUGH_NOALLOC t_data_sg: %p t_data_nents:"
614 			 " %u\n", cmd->t_data_sg, cmd->t_data_nents);
615 	}
616 
617 	return 0;
618 
619 out:
620 	return ret;
621 }
622 
623 static int target_xcopy_issue_pt_cmd(struct xcopy_pt_cmd *xpt_cmd)
624 {
625 	struct se_cmd *se_cmd = &xpt_cmd->se_cmd;
626 	sense_reason_t sense_rc;
627 
628 	sense_rc = transport_generic_new_cmd(se_cmd);
629 	if (sense_rc)
630 		return -EINVAL;
631 
632 	if (se_cmd->data_direction == DMA_TO_DEVICE)
633 		target_execute_cmd(se_cmd);
634 
635 	wait_for_completion_interruptible(&xpt_cmd->xpt_passthrough_sem);
636 
637 	pr_debug("target_xcopy_issue_pt_cmd(): SCSI status: 0x%02x\n",
638 			se_cmd->scsi_status);
639 
640 	return (se_cmd->scsi_status) ? -EINVAL : 0;
641 }
642 
643 static int target_xcopy_read_source(
644 	struct se_cmd *ec_cmd,
645 	struct xcopy_op *xop,
646 	struct se_device *src_dev,
647 	sector_t src_lba,
648 	u32 src_sectors)
649 {
650 	struct xcopy_pt_cmd *xpt_cmd;
651 	struct se_cmd *se_cmd;
652 	u32 length = (src_sectors * src_dev->dev_attrib.block_size);
653 	int rc;
654 	unsigned char cdb[16];
655 	bool remote_port = (xop->op_origin == XCOL_DEST_RECV_OP);
656 
657 	xpt_cmd = kzalloc(sizeof(struct xcopy_pt_cmd), GFP_KERNEL);
658 	if (!xpt_cmd) {
659 		pr_err("Unable to allocate xcopy_pt_cmd\n");
660 		return -ENOMEM;
661 	}
662 	init_completion(&xpt_cmd->xpt_passthrough_sem);
663 	se_cmd = &xpt_cmd->se_cmd;
664 
665 	memset(&cdb[0], 0, 16);
666 	cdb[0] = READ_16;
667 	put_unaligned_be64(src_lba, &cdb[2]);
668 	put_unaligned_be32(src_sectors, &cdb[10]);
669 	pr_debug("XCOPY: Built READ_16: LBA: %llu Sectors: %u Length: %u\n",
670 		(unsigned long long)src_lba, src_sectors, length);
671 
672 	transport_init_se_cmd(se_cmd, &xcopy_pt_tfo, NULL, length,
673 			      DMA_FROM_DEVICE, 0, &xpt_cmd->sense_buffer[0]);
674 	xop->src_pt_cmd = xpt_cmd;
675 
676 	rc = target_xcopy_setup_pt_cmd(xpt_cmd, xop, src_dev, &cdb[0],
677 				remote_port, true);
678 	if (rc < 0) {
679 		transport_generic_free_cmd(se_cmd, 0);
680 		return rc;
681 	}
682 
683 	xop->xop_data_sg = se_cmd->t_data_sg;
684 	xop->xop_data_nents = se_cmd->t_data_nents;
685 	pr_debug("XCOPY-READ: Saved xop->xop_data_sg: %p, num: %u for READ"
686 		" memory\n", xop->xop_data_sg, xop->xop_data_nents);
687 
688 	rc = target_xcopy_issue_pt_cmd(xpt_cmd);
689 	if (rc < 0) {
690 		transport_generic_free_cmd(se_cmd, 0);
691 		return rc;
692 	}
693 	/*
694 	 * Clear off the allocated t_data_sg, that has been saved for
695 	 * zero-copy WRITE submission reuse in struct xcopy_op..
696 	 */
697 	se_cmd->t_data_sg = NULL;
698 	se_cmd->t_data_nents = 0;
699 
700 	return 0;
701 }
702 
703 static int target_xcopy_write_destination(
704 	struct se_cmd *ec_cmd,
705 	struct xcopy_op *xop,
706 	struct se_device *dst_dev,
707 	sector_t dst_lba,
708 	u32 dst_sectors)
709 {
710 	struct xcopy_pt_cmd *xpt_cmd;
711 	struct se_cmd *se_cmd;
712 	u32 length = (dst_sectors * dst_dev->dev_attrib.block_size);
713 	int rc;
714 	unsigned char cdb[16];
715 	bool remote_port = (xop->op_origin == XCOL_SOURCE_RECV_OP);
716 
717 	xpt_cmd = kzalloc(sizeof(struct xcopy_pt_cmd), GFP_KERNEL);
718 	if (!xpt_cmd) {
719 		pr_err("Unable to allocate xcopy_pt_cmd\n");
720 		return -ENOMEM;
721 	}
722 	init_completion(&xpt_cmd->xpt_passthrough_sem);
723 	se_cmd = &xpt_cmd->se_cmd;
724 
725 	memset(&cdb[0], 0, 16);
726 	cdb[0] = WRITE_16;
727 	put_unaligned_be64(dst_lba, &cdb[2]);
728 	put_unaligned_be32(dst_sectors, &cdb[10]);
729 	pr_debug("XCOPY: Built WRITE_16: LBA: %llu Sectors: %u Length: %u\n",
730 		(unsigned long long)dst_lba, dst_sectors, length);
731 
732 	transport_init_se_cmd(se_cmd, &xcopy_pt_tfo, NULL, length,
733 			      DMA_TO_DEVICE, 0, &xpt_cmd->sense_buffer[0]);
734 	xop->dst_pt_cmd = xpt_cmd;
735 
736 	rc = target_xcopy_setup_pt_cmd(xpt_cmd, xop, dst_dev, &cdb[0],
737 				remote_port, false);
738 	if (rc < 0) {
739 		struct se_cmd *src_cmd = &xop->src_pt_cmd->se_cmd;
740 		/*
741 		 * If the failure happened before the t_mem_list hand-off in
742 		 * target_xcopy_setup_pt_cmd(), Reset memory + clear flag so that
743 		 * core releases this memory on error during X-COPY WRITE I/O.
744 		 */
745 		src_cmd->se_cmd_flags &= ~SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
746 		src_cmd->t_data_sg = xop->xop_data_sg;
747 		src_cmd->t_data_nents = xop->xop_data_nents;
748 
749 		transport_generic_free_cmd(se_cmd, 0);
750 		return rc;
751 	}
752 
753 	rc = target_xcopy_issue_pt_cmd(xpt_cmd);
754 	if (rc < 0) {
755 		se_cmd->se_cmd_flags &= ~SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
756 		transport_generic_free_cmd(se_cmd, 0);
757 		return rc;
758 	}
759 
760 	return 0;
761 }
762 
763 static void target_xcopy_do_work(struct work_struct *work)
764 {
765 	struct xcopy_op *xop = container_of(work, struct xcopy_op, xop_work);
766 	struct se_device *src_dev = xop->src_dev, *dst_dev = xop->dst_dev;
767 	struct se_cmd *ec_cmd = xop->xop_se_cmd;
768 	sector_t src_lba = xop->src_lba, dst_lba = xop->dst_lba, end_lba;
769 	unsigned int max_sectors;
770 	int rc;
771 	unsigned short nolb = xop->nolb, cur_nolb, max_nolb, copied_nolb = 0;
772 
773 	end_lba = src_lba + nolb;
774 	/*
775 	 * Break up XCOPY I/O into hw_max_sectors sized I/O based on the
776 	 * smallest max_sectors between src_dev + dev_dev, or
777 	 */
778 	max_sectors = min(src_dev->dev_attrib.hw_max_sectors,
779 			  dst_dev->dev_attrib.hw_max_sectors);
780 	max_sectors = min_t(u32, max_sectors, XCOPY_MAX_SECTORS);
781 
782 	max_nolb = min_t(u16, max_sectors, ((u16)(~0U)));
783 
784 	pr_debug("target_xcopy_do_work: nolb: %hu, max_nolb: %hu end_lba: %llu\n",
785 			nolb, max_nolb, (unsigned long long)end_lba);
786 	pr_debug("target_xcopy_do_work: Starting src_lba: %llu, dst_lba: %llu\n",
787 			(unsigned long long)src_lba, (unsigned long long)dst_lba);
788 
789 	while (src_lba < end_lba) {
790 		cur_nolb = min(nolb, max_nolb);
791 
792 		pr_debug("target_xcopy_do_work: Calling read src_dev: %p src_lba: %llu,"
793 			" cur_nolb: %hu\n", src_dev, (unsigned long long)src_lba, cur_nolb);
794 
795 		rc = target_xcopy_read_source(ec_cmd, xop, src_dev, src_lba, cur_nolb);
796 		if (rc < 0)
797 			goto out;
798 
799 		src_lba += cur_nolb;
800 		pr_debug("target_xcopy_do_work: Incremented READ src_lba to %llu\n",
801 				(unsigned long long)src_lba);
802 
803 		pr_debug("target_xcopy_do_work: Calling write dst_dev: %p dst_lba: %llu,"
804 			" cur_nolb: %hu\n", dst_dev, (unsigned long long)dst_lba, cur_nolb);
805 
806 		rc = target_xcopy_write_destination(ec_cmd, xop, dst_dev,
807 						dst_lba, cur_nolb);
808 		if (rc < 0) {
809 			transport_generic_free_cmd(&xop->src_pt_cmd->se_cmd, 0);
810 			goto out;
811 		}
812 
813 		dst_lba += cur_nolb;
814 		pr_debug("target_xcopy_do_work: Incremented WRITE dst_lba to %llu\n",
815 				(unsigned long long)dst_lba);
816 
817 		copied_nolb += cur_nolb;
818 		nolb -= cur_nolb;
819 
820 		transport_generic_free_cmd(&xop->src_pt_cmd->se_cmd, 0);
821 		xop->dst_pt_cmd->se_cmd.se_cmd_flags &= ~SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
822 
823 		transport_generic_free_cmd(&xop->dst_pt_cmd->se_cmd, 0);
824 	}
825 
826 	xcopy_pt_undepend_remotedev(xop);
827 	kfree(xop);
828 
829 	pr_debug("target_xcopy_do_work: Final src_lba: %llu, dst_lba: %llu\n",
830 		(unsigned long long)src_lba, (unsigned long long)dst_lba);
831 	pr_debug("target_xcopy_do_work: Blocks copied: %hu, Bytes Copied: %u\n",
832 		copied_nolb, copied_nolb * dst_dev->dev_attrib.block_size);
833 
834 	pr_debug("target_xcopy_do_work: Setting X-COPY GOOD status -> sending response\n");
835 	target_complete_cmd(ec_cmd, SAM_STAT_GOOD);
836 	return;
837 
838 out:
839 	xcopy_pt_undepend_remotedev(xop);
840 	kfree(xop);
841 
842 	pr_warn("target_xcopy_do_work: Setting X-COPY CHECK_CONDITION -> sending response\n");
843 	ec_cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
844 	target_complete_cmd(ec_cmd, SAM_STAT_CHECK_CONDITION);
845 }
846 
847 sense_reason_t target_do_xcopy(struct se_cmd *se_cmd)
848 {
849 	struct se_device *dev = se_cmd->se_dev;
850 	struct xcopy_op *xop = NULL;
851 	unsigned char *p = NULL, *seg_desc;
852 	unsigned int list_id, list_id_usage, sdll, inline_dl, sa;
853 	sense_reason_t ret = TCM_INVALID_PARAMETER_LIST;
854 	int rc;
855 	unsigned short tdll;
856 
857 	if (!dev->dev_attrib.emulate_3pc) {
858 		pr_err("EXTENDED_COPY operation explicitly disabled\n");
859 		return TCM_UNSUPPORTED_SCSI_OPCODE;
860 	}
861 
862 	sa = se_cmd->t_task_cdb[1] & 0x1f;
863 	if (sa != 0x00) {
864 		pr_err("EXTENDED_COPY(LID4) not supported\n");
865 		return TCM_UNSUPPORTED_SCSI_OPCODE;
866 	}
867 
868 	xop = kzalloc(sizeof(struct xcopy_op), GFP_KERNEL);
869 	if (!xop) {
870 		pr_err("Unable to allocate xcopy_op\n");
871 		return TCM_OUT_OF_RESOURCES;
872 	}
873 	xop->xop_se_cmd = se_cmd;
874 
875 	p = transport_kmap_data_sg(se_cmd);
876 	if (!p) {
877 		pr_err("transport_kmap_data_sg() failed in target_do_xcopy\n");
878 		kfree(xop);
879 		return TCM_OUT_OF_RESOURCES;
880 	}
881 
882 	list_id = p[0];
883 	list_id_usage = (p[1] & 0x18) >> 3;
884 
885 	/*
886 	 * Determine TARGET DESCRIPTOR LIST LENGTH + SEGMENT DESCRIPTOR LIST LENGTH
887 	 */
888 	tdll = get_unaligned_be16(&p[2]);
889 	sdll = get_unaligned_be32(&p[8]);
890 
891 	inline_dl = get_unaligned_be32(&p[12]);
892 	if (inline_dl != 0) {
893 		pr_err("XCOPY with non zero inline data length\n");
894 		goto out;
895 	}
896 
897 	pr_debug("Processing XCOPY with list_id: 0x%02x list_id_usage: 0x%02x"
898 		" tdll: %hu sdll: %u inline_dl: %u\n", list_id, list_id_usage,
899 		tdll, sdll, inline_dl);
900 
901 	rc = target_xcopy_parse_target_descriptors(se_cmd, xop, &p[16], tdll);
902 	if (rc <= 0)
903 		goto out;
904 
905 	if (xop->src_dev->dev_attrib.block_size !=
906 	    xop->dst_dev->dev_attrib.block_size) {
907 		pr_err("XCOPY: Non matching src_dev block_size: %u + dst_dev"
908 		       " block_size: %u currently unsupported\n",
909 			xop->src_dev->dev_attrib.block_size,
910 			xop->dst_dev->dev_attrib.block_size);
911 		xcopy_pt_undepend_remotedev(xop);
912 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
913 		goto out;
914 	}
915 
916 	pr_debug("XCOPY: Processed %d target descriptors, length: %u\n", rc,
917 				rc * XCOPY_TARGET_DESC_LEN);
918 	seg_desc = &p[16];
919 	seg_desc += (rc * XCOPY_TARGET_DESC_LEN);
920 
921 	rc = target_xcopy_parse_segment_descriptors(se_cmd, xop, seg_desc, sdll);
922 	if (rc <= 0) {
923 		xcopy_pt_undepend_remotedev(xop);
924 		goto out;
925 	}
926 	transport_kunmap_data_sg(se_cmd);
927 
928 	pr_debug("XCOPY: Processed %d segment descriptors, length: %u\n", rc,
929 				rc * XCOPY_SEGMENT_DESC_LEN);
930 	INIT_WORK(&xop->xop_work, target_xcopy_do_work);
931 	queue_work(xcopy_wq, &xop->xop_work);
932 	return TCM_NO_SENSE;
933 
934 out:
935 	if (p)
936 		transport_kunmap_data_sg(se_cmd);
937 	kfree(xop);
938 	return ret;
939 }
940 
941 static sense_reason_t target_rcr_operating_parameters(struct se_cmd *se_cmd)
942 {
943 	unsigned char *p;
944 
945 	p = transport_kmap_data_sg(se_cmd);
946 	if (!p) {
947 		pr_err("transport_kmap_data_sg failed in"
948 		       " target_rcr_operating_parameters\n");
949 		return TCM_OUT_OF_RESOURCES;
950 	}
951 
952 	if (se_cmd->data_length < 54) {
953 		pr_err("Receive Copy Results Op Parameters length"
954 		       " too small: %u\n", se_cmd->data_length);
955 		transport_kunmap_data_sg(se_cmd);
956 		return TCM_INVALID_CDB_FIELD;
957 	}
958 	/*
959 	 * Set SNLID=1 (Supports no List ID)
960 	 */
961 	p[4] = 0x1;
962 	/*
963 	 * MAXIMUM TARGET DESCRIPTOR COUNT
964 	 */
965 	put_unaligned_be16(RCR_OP_MAX_TARGET_DESC_COUNT, &p[8]);
966 	/*
967 	 * MAXIMUM SEGMENT DESCRIPTOR COUNT
968 	 */
969 	put_unaligned_be16(RCR_OP_MAX_SG_DESC_COUNT, &p[10]);
970 	/*
971 	 * MAXIMUM DESCRIPTOR LIST LENGTH
972 	 */
973 	put_unaligned_be32(RCR_OP_MAX_DESC_LIST_LEN, &p[12]);
974 	/*
975 	 * MAXIMUM SEGMENT LENGTH
976 	 */
977 	put_unaligned_be32(RCR_OP_MAX_SEGMENT_LEN, &p[16]);
978 	/*
979 	 * MAXIMUM INLINE DATA LENGTH for SA 0x04 (NOT SUPPORTED)
980 	 */
981 	put_unaligned_be32(0x0, &p[20]);
982 	/*
983 	 * HELD DATA LIMIT
984 	 */
985 	put_unaligned_be32(0x0, &p[24]);
986 	/*
987 	 * MAXIMUM STREAM DEVICE TRANSFER SIZE
988 	 */
989 	put_unaligned_be32(0x0, &p[28]);
990 	/*
991 	 * TOTAL CONCURRENT COPIES
992 	 */
993 	put_unaligned_be16(RCR_OP_TOTAL_CONCURR_COPIES, &p[34]);
994 	/*
995 	 * MAXIMUM CONCURRENT COPIES
996 	 */
997 	p[36] = RCR_OP_MAX_CONCURR_COPIES;
998 	/*
999 	 * DATA SEGMENT GRANULARITY (log 2)
1000 	 */
1001 	p[37] = RCR_OP_DATA_SEG_GRAN_LOG2;
1002 	/*
1003 	 * INLINE DATA GRANULARITY log 2)
1004 	 */
1005 	p[38] = RCR_OP_INLINE_DATA_GRAN_LOG2;
1006 	/*
1007 	 * HELD DATA GRANULARITY
1008 	 */
1009 	p[39] = RCR_OP_HELD_DATA_GRAN_LOG2;
1010 	/*
1011 	 * IMPLEMENTED DESCRIPTOR LIST LENGTH
1012 	 */
1013 	p[43] = 0x2;
1014 	/*
1015 	 * List of implemented descriptor type codes (ordered)
1016 	 */
1017 	p[44] = 0x02; /* Copy Block to Block device */
1018 	p[45] = 0xe4; /* Identification descriptor target descriptor */
1019 
1020 	/*
1021 	 * AVAILABLE DATA (n-3)
1022 	 */
1023 	put_unaligned_be32(42, &p[0]);
1024 
1025 	transport_kunmap_data_sg(se_cmd);
1026 	target_complete_cmd(se_cmd, GOOD);
1027 
1028 	return TCM_NO_SENSE;
1029 }
1030 
1031 sense_reason_t target_do_receive_copy_results(struct se_cmd *se_cmd)
1032 {
1033 	unsigned char *cdb = &se_cmd->t_task_cdb[0];
1034 	int sa = (cdb[1] & 0x1f), list_id = cdb[2];
1035 	sense_reason_t rc = TCM_NO_SENSE;
1036 
1037 	pr_debug("Entering target_do_receive_copy_results: SA: 0x%02x, List ID:"
1038 		" 0x%02x, AL: %u\n", sa, list_id, se_cmd->data_length);
1039 
1040 	if (list_id != 0) {
1041 		pr_err("Receive Copy Results with non zero list identifier"
1042 		       " not supported\n");
1043 		return TCM_INVALID_CDB_FIELD;
1044 	}
1045 
1046 	switch (sa) {
1047 	case RCR_SA_OPERATING_PARAMETERS:
1048 		rc = target_rcr_operating_parameters(se_cmd);
1049 		break;
1050 	case RCR_SA_COPY_STATUS:
1051 	case RCR_SA_RECEIVE_DATA:
1052 	case RCR_SA_FAILED_SEGMENT_DETAILS:
1053 	default:
1054 		pr_err("Unsupported SA for receive copy results: 0x%02x\n", sa);
1055 		return TCM_INVALID_CDB_FIELD;
1056 	}
1057 
1058 	return rc;
1059 }
1060