1 // SPDX-License-Identifier: GPL-2.0
2 /* Target based USB-Gadget
3  *
4  * UAS protocol handling, target callbacks, configfs handling,
5  * BBB (USB Mass Storage Class Bulk-Only (BBB) and Transport protocol handling.
6  *
7  * Author: Sebastian Andrzej Siewior <bigeasy at linutronix dot de>
8  */
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/types.h>
12 #include <linux/string.h>
13 #include <linux/configfs.h>
14 #include <linux/ctype.h>
15 #include <linux/usb/ch9.h>
16 #include <linux/usb/composite.h>
17 #include <linux/usb/gadget.h>
18 #include <linux/usb/storage.h>
19 #include <scsi/scsi_tcq.h>
20 #include <target/target_core_base.h>
21 #include <target/target_core_fabric.h>
22 #include <asm/unaligned.h>
23 
24 #include "tcm.h"
25 #include "u_tcm.h"
26 #include "configfs.h"
27 
28 #define TPG_INSTANCES		1
29 
30 struct tpg_instance {
31 	struct usb_function_instance	*func_inst;
32 	struct usbg_tpg			*tpg;
33 };
34 
35 static struct tpg_instance tpg_instances[TPG_INSTANCES];
36 
37 static DEFINE_MUTEX(tpg_instances_lock);
38 
39 static inline struct f_uas *to_f_uas(struct usb_function *f)
40 {
41 	return container_of(f, struct f_uas, function);
42 }
43 
44 /* Start bot.c code */
45 
46 static int bot_enqueue_cmd_cbw(struct f_uas *fu)
47 {
48 	int ret;
49 
50 	if (fu->flags & USBG_BOT_CMD_PEND)
51 		return 0;
52 
53 	ret = usb_ep_queue(fu->ep_out, fu->cmd.req, GFP_ATOMIC);
54 	if (!ret)
55 		fu->flags |= USBG_BOT_CMD_PEND;
56 	return ret;
57 }
58 
59 static void bot_status_complete(struct usb_ep *ep, struct usb_request *req)
60 {
61 	struct usbg_cmd *cmd = req->context;
62 	struct f_uas *fu = cmd->fu;
63 
64 	transport_generic_free_cmd(&cmd->se_cmd, 0);
65 	if (req->status < 0) {
66 		pr_err("ERR %s(%d)\n", __func__, __LINE__);
67 		return;
68 	}
69 
70 	/* CSW completed, wait for next CBW */
71 	bot_enqueue_cmd_cbw(fu);
72 }
73 
74 static void bot_enqueue_sense_code(struct f_uas *fu, struct usbg_cmd *cmd)
75 {
76 	struct bulk_cs_wrap *csw = &fu->bot_status.csw;
77 	int ret;
78 	unsigned int csw_stat;
79 
80 	csw_stat = cmd->csw_code;
81 	csw->Tag = cmd->bot_tag;
82 	csw->Status = csw_stat;
83 	fu->bot_status.req->context = cmd;
84 	ret = usb_ep_queue(fu->ep_in, fu->bot_status.req, GFP_ATOMIC);
85 	if (ret)
86 		pr_err("%s(%d) ERR: %d\n", __func__, __LINE__, ret);
87 }
88 
89 static void bot_err_compl(struct usb_ep *ep, struct usb_request *req)
90 {
91 	struct usbg_cmd *cmd = req->context;
92 	struct f_uas *fu = cmd->fu;
93 
94 	if (req->status < 0)
95 		pr_err("ERR %s(%d)\n", __func__, __LINE__);
96 
97 	if (cmd->data_len) {
98 		if (cmd->data_len > ep->maxpacket) {
99 			req->length = ep->maxpacket;
100 			cmd->data_len -= ep->maxpacket;
101 		} else {
102 			req->length = cmd->data_len;
103 			cmd->data_len = 0;
104 		}
105 
106 		usb_ep_queue(ep, req, GFP_ATOMIC);
107 		return;
108 	}
109 	bot_enqueue_sense_code(fu, cmd);
110 }
111 
112 static void bot_send_bad_status(struct usbg_cmd *cmd)
113 {
114 	struct f_uas *fu = cmd->fu;
115 	struct bulk_cs_wrap *csw = &fu->bot_status.csw;
116 	struct usb_request *req;
117 	struct usb_ep *ep;
118 
119 	csw->Residue = cpu_to_le32(cmd->data_len);
120 
121 	if (cmd->data_len) {
122 		if (cmd->is_read) {
123 			ep = fu->ep_in;
124 			req = fu->bot_req_in;
125 		} else {
126 			ep = fu->ep_out;
127 			req = fu->bot_req_out;
128 		}
129 
130 		if (cmd->data_len > fu->ep_in->maxpacket) {
131 			req->length = ep->maxpacket;
132 			cmd->data_len -= ep->maxpacket;
133 		} else {
134 			req->length = cmd->data_len;
135 			cmd->data_len = 0;
136 		}
137 		req->complete = bot_err_compl;
138 		req->context = cmd;
139 		req->buf = fu->cmd.buf;
140 		usb_ep_queue(ep, req, GFP_KERNEL);
141 	} else {
142 		bot_enqueue_sense_code(fu, cmd);
143 	}
144 }
145 
146 static int bot_send_status(struct usbg_cmd *cmd, bool moved_data)
147 {
148 	struct f_uas *fu = cmd->fu;
149 	struct bulk_cs_wrap *csw = &fu->bot_status.csw;
150 	int ret;
151 
152 	if (cmd->se_cmd.scsi_status == SAM_STAT_GOOD) {
153 		if (!moved_data && cmd->data_len) {
154 			/*
155 			 * the host wants to move data, we don't. Fill / empty
156 			 * the pipe and then send the csw with reside set.
157 			 */
158 			cmd->csw_code = US_BULK_STAT_OK;
159 			bot_send_bad_status(cmd);
160 			return 0;
161 		}
162 
163 		csw->Tag = cmd->bot_tag;
164 		csw->Residue = cpu_to_le32(0);
165 		csw->Status = US_BULK_STAT_OK;
166 		fu->bot_status.req->context = cmd;
167 
168 		ret = usb_ep_queue(fu->ep_in, fu->bot_status.req, GFP_KERNEL);
169 		if (ret)
170 			pr_err("%s(%d) ERR: %d\n", __func__, __LINE__, ret);
171 	} else {
172 		cmd->csw_code = US_BULK_STAT_FAIL;
173 		bot_send_bad_status(cmd);
174 	}
175 	return 0;
176 }
177 
178 /*
179  * Called after command (no data transfer) or after the write (to device)
180  * operation is completed
181  */
182 static int bot_send_status_response(struct usbg_cmd *cmd)
183 {
184 	bool moved_data = false;
185 
186 	if (!cmd->is_read)
187 		moved_data = true;
188 	return bot_send_status(cmd, moved_data);
189 }
190 
191 /* Read request completed, now we have to send the CSW */
192 static void bot_read_compl(struct usb_ep *ep, struct usb_request *req)
193 {
194 	struct usbg_cmd *cmd = req->context;
195 
196 	if (req->status < 0)
197 		pr_err("ERR %s(%d)\n", __func__, __LINE__);
198 
199 	bot_send_status(cmd, true);
200 }
201 
202 static int bot_send_read_response(struct usbg_cmd *cmd)
203 {
204 	struct f_uas *fu = cmd->fu;
205 	struct se_cmd *se_cmd = &cmd->se_cmd;
206 	struct usb_gadget *gadget = fuas_to_gadget(fu);
207 	int ret;
208 
209 	if (!cmd->data_len) {
210 		cmd->csw_code = US_BULK_STAT_PHASE;
211 		bot_send_bad_status(cmd);
212 		return 0;
213 	}
214 
215 	if (!gadget->sg_supported) {
216 		cmd->data_buf = kmalloc(se_cmd->data_length, GFP_ATOMIC);
217 		if (!cmd->data_buf)
218 			return -ENOMEM;
219 
220 		sg_copy_to_buffer(se_cmd->t_data_sg,
221 				se_cmd->t_data_nents,
222 				cmd->data_buf,
223 				se_cmd->data_length);
224 
225 		fu->bot_req_in->buf = cmd->data_buf;
226 	} else {
227 		fu->bot_req_in->buf = NULL;
228 		fu->bot_req_in->num_sgs = se_cmd->t_data_nents;
229 		fu->bot_req_in->sg = se_cmd->t_data_sg;
230 	}
231 
232 	fu->bot_req_in->complete = bot_read_compl;
233 	fu->bot_req_in->length = se_cmd->data_length;
234 	fu->bot_req_in->context = cmd;
235 	ret = usb_ep_queue(fu->ep_in, fu->bot_req_in, GFP_ATOMIC);
236 	if (ret)
237 		pr_err("%s(%d)\n", __func__, __LINE__);
238 	return 0;
239 }
240 
241 static void usbg_data_write_cmpl(struct usb_ep *, struct usb_request *);
242 static int usbg_prepare_w_request(struct usbg_cmd *, struct usb_request *);
243 
244 static int bot_send_write_request(struct usbg_cmd *cmd)
245 {
246 	struct f_uas *fu = cmd->fu;
247 	struct se_cmd *se_cmd = &cmd->se_cmd;
248 	struct usb_gadget *gadget = fuas_to_gadget(fu);
249 	int ret;
250 
251 	init_completion(&cmd->write_complete);
252 	cmd->fu = fu;
253 
254 	if (!cmd->data_len) {
255 		cmd->csw_code = US_BULK_STAT_PHASE;
256 		return -EINVAL;
257 	}
258 
259 	if (!gadget->sg_supported) {
260 		cmd->data_buf = kmalloc(se_cmd->data_length, GFP_KERNEL);
261 		if (!cmd->data_buf)
262 			return -ENOMEM;
263 
264 		fu->bot_req_out->buf = cmd->data_buf;
265 	} else {
266 		fu->bot_req_out->buf = NULL;
267 		fu->bot_req_out->num_sgs = se_cmd->t_data_nents;
268 		fu->bot_req_out->sg = se_cmd->t_data_sg;
269 	}
270 
271 	fu->bot_req_out->complete = usbg_data_write_cmpl;
272 	fu->bot_req_out->length = se_cmd->data_length;
273 	fu->bot_req_out->context = cmd;
274 
275 	ret = usbg_prepare_w_request(cmd, fu->bot_req_out);
276 	if (ret)
277 		goto cleanup;
278 	ret = usb_ep_queue(fu->ep_out, fu->bot_req_out, GFP_KERNEL);
279 	if (ret)
280 		pr_err("%s(%d)\n", __func__, __LINE__);
281 
282 	wait_for_completion(&cmd->write_complete);
283 	target_execute_cmd(se_cmd);
284 cleanup:
285 	return ret;
286 }
287 
288 static int bot_submit_command(struct f_uas *, void *, unsigned int);
289 
290 static void bot_cmd_complete(struct usb_ep *ep, struct usb_request *req)
291 {
292 	struct f_uas *fu = req->context;
293 	int ret;
294 
295 	fu->flags &= ~USBG_BOT_CMD_PEND;
296 
297 	if (req->status < 0)
298 		return;
299 
300 	ret = bot_submit_command(fu, req->buf, req->actual);
301 	if (ret)
302 		pr_err("%s(%d): %d\n", __func__, __LINE__, ret);
303 }
304 
305 static int bot_prepare_reqs(struct f_uas *fu)
306 {
307 	int ret;
308 
309 	fu->bot_req_in = usb_ep_alloc_request(fu->ep_in, GFP_KERNEL);
310 	if (!fu->bot_req_in)
311 		goto err;
312 
313 	fu->bot_req_out = usb_ep_alloc_request(fu->ep_out, GFP_KERNEL);
314 	if (!fu->bot_req_out)
315 		goto err_out;
316 
317 	fu->cmd.req = usb_ep_alloc_request(fu->ep_out, GFP_KERNEL);
318 	if (!fu->cmd.req)
319 		goto err_cmd;
320 
321 	fu->bot_status.req = usb_ep_alloc_request(fu->ep_in, GFP_KERNEL);
322 	if (!fu->bot_status.req)
323 		goto err_sts;
324 
325 	fu->bot_status.req->buf = &fu->bot_status.csw;
326 	fu->bot_status.req->length = US_BULK_CS_WRAP_LEN;
327 	fu->bot_status.req->complete = bot_status_complete;
328 	fu->bot_status.csw.Signature = cpu_to_le32(US_BULK_CS_SIGN);
329 
330 	fu->cmd.buf = kmalloc(fu->ep_out->maxpacket, GFP_KERNEL);
331 	if (!fu->cmd.buf)
332 		goto err_buf;
333 
334 	fu->cmd.req->complete = bot_cmd_complete;
335 	fu->cmd.req->buf = fu->cmd.buf;
336 	fu->cmd.req->length = fu->ep_out->maxpacket;
337 	fu->cmd.req->context = fu;
338 
339 	ret = bot_enqueue_cmd_cbw(fu);
340 	if (ret)
341 		goto err_queue;
342 	return 0;
343 err_queue:
344 	kfree(fu->cmd.buf);
345 	fu->cmd.buf = NULL;
346 err_buf:
347 	usb_ep_free_request(fu->ep_in, fu->bot_status.req);
348 err_sts:
349 	usb_ep_free_request(fu->ep_out, fu->cmd.req);
350 	fu->cmd.req = NULL;
351 err_cmd:
352 	usb_ep_free_request(fu->ep_out, fu->bot_req_out);
353 	fu->bot_req_out = NULL;
354 err_out:
355 	usb_ep_free_request(fu->ep_in, fu->bot_req_in);
356 	fu->bot_req_in = NULL;
357 err:
358 	pr_err("BOT: endpoint setup failed\n");
359 	return -ENOMEM;
360 }
361 
362 static void bot_cleanup_old_alt(struct f_uas *fu)
363 {
364 	if (!(fu->flags & USBG_ENABLED))
365 		return;
366 
367 	usb_ep_disable(fu->ep_in);
368 	usb_ep_disable(fu->ep_out);
369 
370 	if (!fu->bot_req_in)
371 		return;
372 
373 	usb_ep_free_request(fu->ep_in, fu->bot_req_in);
374 	usb_ep_free_request(fu->ep_out, fu->bot_req_out);
375 	usb_ep_free_request(fu->ep_out, fu->cmd.req);
376 	usb_ep_free_request(fu->ep_in, fu->bot_status.req);
377 
378 	kfree(fu->cmd.buf);
379 
380 	fu->bot_req_in = NULL;
381 	fu->bot_req_out = NULL;
382 	fu->cmd.req = NULL;
383 	fu->bot_status.req = NULL;
384 	fu->cmd.buf = NULL;
385 }
386 
387 static void bot_set_alt(struct f_uas *fu)
388 {
389 	struct usb_function *f = &fu->function;
390 	struct usb_gadget *gadget = f->config->cdev->gadget;
391 	int ret;
392 
393 	fu->flags = USBG_IS_BOT;
394 
395 	config_ep_by_speed_and_alt(gadget, f, fu->ep_in, USB_G_ALT_INT_BBB);
396 	ret = usb_ep_enable(fu->ep_in);
397 	if (ret)
398 		goto err_b_in;
399 
400 	config_ep_by_speed_and_alt(gadget, f, fu->ep_out, USB_G_ALT_INT_BBB);
401 	ret = usb_ep_enable(fu->ep_out);
402 	if (ret)
403 		goto err_b_out;
404 
405 	ret = bot_prepare_reqs(fu);
406 	if (ret)
407 		goto err_wq;
408 	fu->flags |= USBG_ENABLED;
409 	pr_info("Using the BOT protocol\n");
410 	return;
411 err_wq:
412 	usb_ep_disable(fu->ep_out);
413 err_b_out:
414 	usb_ep_disable(fu->ep_in);
415 err_b_in:
416 	fu->flags = USBG_IS_BOT;
417 }
418 
419 static int usbg_bot_setup(struct usb_function *f,
420 		const struct usb_ctrlrequest *ctrl)
421 {
422 	struct f_uas *fu = to_f_uas(f);
423 	struct usb_composite_dev *cdev = f->config->cdev;
424 	u16 w_value = le16_to_cpu(ctrl->wValue);
425 	u16 w_length = le16_to_cpu(ctrl->wLength);
426 	int luns;
427 	u8 *ret_lun;
428 
429 	switch (ctrl->bRequest) {
430 	case US_BULK_GET_MAX_LUN:
431 		if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_CLASS |
432 					USB_RECIP_INTERFACE))
433 			return -ENOTSUPP;
434 
435 		if (w_length < 1)
436 			return -EINVAL;
437 		if (w_value != 0)
438 			return -EINVAL;
439 		luns = atomic_read(&fu->tpg->tpg_port_count);
440 		if (!luns) {
441 			pr_err("No LUNs configured?\n");
442 			return -EINVAL;
443 		}
444 		/*
445 		 * If 4 LUNs are present we return 3 i.e. LUN 0..3 can be
446 		 * accessed. The upper limit is 0xf
447 		 */
448 		luns--;
449 		if (luns > 0xf) {
450 			pr_info_once("Limiting the number of luns to 16\n");
451 			luns = 0xf;
452 		}
453 		ret_lun = cdev->req->buf;
454 		*ret_lun = luns;
455 		cdev->req->length = 1;
456 		return usb_ep_queue(cdev->gadget->ep0, cdev->req, GFP_ATOMIC);
457 
458 	case US_BULK_RESET_REQUEST:
459 		/* XXX maybe we should remove previous requests for IN + OUT */
460 		bot_enqueue_cmd_cbw(fu);
461 		return 0;
462 	}
463 	return -ENOTSUPP;
464 }
465 
466 /* Start uas.c code */
467 
468 static void uasp_cleanup_one_stream(struct f_uas *fu, struct uas_stream *stream)
469 {
470 	/* We have either all three allocated or none */
471 	if (!stream->req_in)
472 		return;
473 
474 	usb_ep_free_request(fu->ep_in, stream->req_in);
475 	usb_ep_free_request(fu->ep_out, stream->req_out);
476 	usb_ep_free_request(fu->ep_status, stream->req_status);
477 
478 	stream->req_in = NULL;
479 	stream->req_out = NULL;
480 	stream->req_status = NULL;
481 }
482 
483 static void uasp_free_cmdreq(struct f_uas *fu)
484 {
485 	usb_ep_free_request(fu->ep_cmd, fu->cmd.req);
486 	kfree(fu->cmd.buf);
487 	fu->cmd.req = NULL;
488 	fu->cmd.buf = NULL;
489 }
490 
491 static void uasp_cleanup_old_alt(struct f_uas *fu)
492 {
493 	int i;
494 
495 	if (!(fu->flags & USBG_ENABLED))
496 		return;
497 
498 	usb_ep_disable(fu->ep_in);
499 	usb_ep_disable(fu->ep_out);
500 	usb_ep_disable(fu->ep_status);
501 	usb_ep_disable(fu->ep_cmd);
502 
503 	for (i = 0; i < UASP_SS_EP_COMP_NUM_STREAMS; i++)
504 		uasp_cleanup_one_stream(fu, &fu->stream[i]);
505 	uasp_free_cmdreq(fu);
506 }
507 
508 static void uasp_status_data_cmpl(struct usb_ep *ep, struct usb_request *req);
509 
510 static int uasp_prepare_r_request(struct usbg_cmd *cmd)
511 {
512 	struct se_cmd *se_cmd = &cmd->se_cmd;
513 	struct f_uas *fu = cmd->fu;
514 	struct usb_gadget *gadget = fuas_to_gadget(fu);
515 	struct uas_stream *stream = cmd->stream;
516 
517 	if (!gadget->sg_supported) {
518 		cmd->data_buf = kmalloc(se_cmd->data_length, GFP_ATOMIC);
519 		if (!cmd->data_buf)
520 			return -ENOMEM;
521 
522 		sg_copy_to_buffer(se_cmd->t_data_sg,
523 				se_cmd->t_data_nents,
524 				cmd->data_buf,
525 				se_cmd->data_length);
526 
527 		stream->req_in->buf = cmd->data_buf;
528 	} else {
529 		stream->req_in->buf = NULL;
530 		stream->req_in->num_sgs = se_cmd->t_data_nents;
531 		stream->req_in->sg = se_cmd->t_data_sg;
532 	}
533 
534 	stream->req_in->is_last = 1;
535 	stream->req_in->complete = uasp_status_data_cmpl;
536 	stream->req_in->length = se_cmd->data_length;
537 	stream->req_in->context = cmd;
538 
539 	cmd->state = UASP_SEND_STATUS;
540 	return 0;
541 }
542 
543 static void uasp_prepare_status(struct usbg_cmd *cmd)
544 {
545 	struct se_cmd *se_cmd = &cmd->se_cmd;
546 	struct sense_iu *iu = &cmd->sense_iu;
547 	struct uas_stream *stream = cmd->stream;
548 
549 	cmd->state = UASP_QUEUE_COMMAND;
550 	iu->iu_id = IU_ID_STATUS;
551 	iu->tag = cpu_to_be16(cmd->tag);
552 
553 	/*
554 	 * iu->status_qual = cpu_to_be16(STATUS QUALIFIER SAM-4. Where R U?);
555 	 */
556 	iu->len = cpu_to_be16(se_cmd->scsi_sense_length);
557 	iu->status = se_cmd->scsi_status;
558 	stream->req_status->is_last = 1;
559 	stream->req_status->context = cmd;
560 	stream->req_status->length = se_cmd->scsi_sense_length + 16;
561 	stream->req_status->buf = iu;
562 	stream->req_status->complete = uasp_status_data_cmpl;
563 }
564 
565 static void uasp_status_data_cmpl(struct usb_ep *ep, struct usb_request *req)
566 {
567 	struct usbg_cmd *cmd = req->context;
568 	struct uas_stream *stream = cmd->stream;
569 	struct f_uas *fu = cmd->fu;
570 	int ret;
571 
572 	if (req->status < 0)
573 		goto cleanup;
574 
575 	switch (cmd->state) {
576 	case UASP_SEND_DATA:
577 		ret = uasp_prepare_r_request(cmd);
578 		if (ret)
579 			goto cleanup;
580 		ret = usb_ep_queue(fu->ep_in, stream->req_in, GFP_ATOMIC);
581 		if (ret)
582 			pr_err("%s(%d) => %d\n", __func__, __LINE__, ret);
583 		break;
584 
585 	case UASP_RECEIVE_DATA:
586 		ret = usbg_prepare_w_request(cmd, stream->req_out);
587 		if (ret)
588 			goto cleanup;
589 		ret = usb_ep_queue(fu->ep_out, stream->req_out, GFP_ATOMIC);
590 		if (ret)
591 			pr_err("%s(%d) => %d\n", __func__, __LINE__, ret);
592 		break;
593 
594 	case UASP_SEND_STATUS:
595 		uasp_prepare_status(cmd);
596 		ret = usb_ep_queue(fu->ep_status, stream->req_status,
597 				GFP_ATOMIC);
598 		if (ret)
599 			pr_err("%s(%d) => %d\n", __func__, __LINE__, ret);
600 		break;
601 
602 	case UASP_QUEUE_COMMAND:
603 		transport_generic_free_cmd(&cmd->se_cmd, 0);
604 		usb_ep_queue(fu->ep_cmd, fu->cmd.req, GFP_ATOMIC);
605 		break;
606 
607 	default:
608 		BUG();
609 	}
610 	return;
611 
612 cleanup:
613 	transport_generic_free_cmd(&cmd->se_cmd, 0);
614 }
615 
616 static int uasp_send_status_response(struct usbg_cmd *cmd)
617 {
618 	struct f_uas *fu = cmd->fu;
619 	struct uas_stream *stream = cmd->stream;
620 	struct sense_iu *iu = &cmd->sense_iu;
621 
622 	iu->tag = cpu_to_be16(cmd->tag);
623 	stream->req_status->complete = uasp_status_data_cmpl;
624 	stream->req_status->context = cmd;
625 	cmd->fu = fu;
626 	uasp_prepare_status(cmd);
627 	return usb_ep_queue(fu->ep_status, stream->req_status, GFP_ATOMIC);
628 }
629 
630 static int uasp_send_read_response(struct usbg_cmd *cmd)
631 {
632 	struct f_uas *fu = cmd->fu;
633 	struct uas_stream *stream = cmd->stream;
634 	struct sense_iu *iu = &cmd->sense_iu;
635 	int ret;
636 
637 	cmd->fu = fu;
638 
639 	iu->tag = cpu_to_be16(cmd->tag);
640 	if (fu->flags & USBG_USE_STREAMS) {
641 
642 		ret = uasp_prepare_r_request(cmd);
643 		if (ret)
644 			goto out;
645 		ret = usb_ep_queue(fu->ep_in, stream->req_in, GFP_ATOMIC);
646 		if (ret) {
647 			pr_err("%s(%d) => %d\n", __func__, __LINE__, ret);
648 			kfree(cmd->data_buf);
649 			cmd->data_buf = NULL;
650 		}
651 
652 	} else {
653 
654 		iu->iu_id = IU_ID_READ_READY;
655 		iu->tag = cpu_to_be16(cmd->tag);
656 
657 		stream->req_status->complete = uasp_status_data_cmpl;
658 		stream->req_status->context = cmd;
659 
660 		cmd->state = UASP_SEND_DATA;
661 		stream->req_status->buf = iu;
662 		stream->req_status->length = sizeof(struct iu);
663 
664 		ret = usb_ep_queue(fu->ep_status, stream->req_status,
665 				GFP_ATOMIC);
666 		if (ret)
667 			pr_err("%s(%d) => %d\n", __func__, __LINE__, ret);
668 	}
669 out:
670 	return ret;
671 }
672 
673 static int uasp_send_write_request(struct usbg_cmd *cmd)
674 {
675 	struct f_uas *fu = cmd->fu;
676 	struct se_cmd *se_cmd = &cmd->se_cmd;
677 	struct uas_stream *stream = cmd->stream;
678 	struct sense_iu *iu = &cmd->sense_iu;
679 	int ret;
680 
681 	init_completion(&cmd->write_complete);
682 	cmd->fu = fu;
683 
684 	iu->tag = cpu_to_be16(cmd->tag);
685 
686 	if (fu->flags & USBG_USE_STREAMS) {
687 
688 		ret = usbg_prepare_w_request(cmd, stream->req_out);
689 		if (ret)
690 			goto cleanup;
691 		ret = usb_ep_queue(fu->ep_out, stream->req_out, GFP_ATOMIC);
692 		if (ret)
693 			pr_err("%s(%d)\n", __func__, __LINE__);
694 
695 	} else {
696 
697 		iu->iu_id = IU_ID_WRITE_READY;
698 		iu->tag = cpu_to_be16(cmd->tag);
699 
700 		stream->req_status->complete = uasp_status_data_cmpl;
701 		stream->req_status->context = cmd;
702 
703 		cmd->state = UASP_RECEIVE_DATA;
704 		stream->req_status->buf = iu;
705 		stream->req_status->length = sizeof(struct iu);
706 
707 		ret = usb_ep_queue(fu->ep_status, stream->req_status,
708 				GFP_ATOMIC);
709 		if (ret)
710 			pr_err("%s(%d)\n", __func__, __LINE__);
711 	}
712 
713 	wait_for_completion(&cmd->write_complete);
714 	target_execute_cmd(se_cmd);
715 cleanup:
716 	return ret;
717 }
718 
719 static int usbg_submit_command(struct f_uas *, void *, unsigned int);
720 
721 static void uasp_cmd_complete(struct usb_ep *ep, struct usb_request *req)
722 {
723 	struct f_uas *fu = req->context;
724 	int ret;
725 
726 	if (req->status < 0)
727 		return;
728 
729 	ret = usbg_submit_command(fu, req->buf, req->actual);
730 	/*
731 	 * Once we tune for performance enqueue the command req here again so
732 	 * we can receive a second command while we processing this one. Pay
733 	 * attention to properly sync STAUS endpoint with DATA IN + OUT so you
734 	 * don't break HS.
735 	 */
736 	if (!ret)
737 		return;
738 	usb_ep_queue(fu->ep_cmd, fu->cmd.req, GFP_ATOMIC);
739 }
740 
741 static int uasp_alloc_stream_res(struct f_uas *fu, struct uas_stream *stream)
742 {
743 	stream->req_in = usb_ep_alloc_request(fu->ep_in, GFP_KERNEL);
744 	if (!stream->req_in)
745 		goto out;
746 
747 	stream->req_out = usb_ep_alloc_request(fu->ep_out, GFP_KERNEL);
748 	if (!stream->req_out)
749 		goto err_out;
750 
751 	stream->req_status = usb_ep_alloc_request(fu->ep_status, GFP_KERNEL);
752 	if (!stream->req_status)
753 		goto err_sts;
754 
755 	return 0;
756 
757 err_sts:
758 	usb_ep_free_request(fu->ep_out, stream->req_out);
759 	stream->req_out = NULL;
760 err_out:
761 	usb_ep_free_request(fu->ep_in, stream->req_in);
762 	stream->req_in = NULL;
763 out:
764 	return -ENOMEM;
765 }
766 
767 static int uasp_alloc_cmd(struct f_uas *fu)
768 {
769 	fu->cmd.req = usb_ep_alloc_request(fu->ep_cmd, GFP_KERNEL);
770 	if (!fu->cmd.req)
771 		goto err;
772 
773 	fu->cmd.buf = kmalloc(fu->ep_cmd->maxpacket, GFP_KERNEL);
774 	if (!fu->cmd.buf)
775 		goto err_buf;
776 
777 	fu->cmd.req->complete = uasp_cmd_complete;
778 	fu->cmd.req->buf = fu->cmd.buf;
779 	fu->cmd.req->length = fu->ep_cmd->maxpacket;
780 	fu->cmd.req->context = fu;
781 	return 0;
782 
783 err_buf:
784 	usb_ep_free_request(fu->ep_cmd, fu->cmd.req);
785 err:
786 	return -ENOMEM;
787 }
788 
789 static void uasp_setup_stream_res(struct f_uas *fu, int max_streams)
790 {
791 	int i;
792 
793 	for (i = 0; i < max_streams; i++) {
794 		struct uas_stream *s = &fu->stream[i];
795 
796 		s->req_in->stream_id = i + 1;
797 		s->req_out->stream_id = i + 1;
798 		s->req_status->stream_id = i + 1;
799 	}
800 }
801 
802 static int uasp_prepare_reqs(struct f_uas *fu)
803 {
804 	int ret;
805 	int i;
806 	int max_streams;
807 
808 	if (fu->flags & USBG_USE_STREAMS)
809 		max_streams = UASP_SS_EP_COMP_NUM_STREAMS;
810 	else
811 		max_streams = 1;
812 
813 	for (i = 0; i < max_streams; i++) {
814 		ret = uasp_alloc_stream_res(fu, &fu->stream[i]);
815 		if (ret)
816 			goto err_cleanup;
817 	}
818 
819 	ret = uasp_alloc_cmd(fu);
820 	if (ret)
821 		goto err_free_stream;
822 	uasp_setup_stream_res(fu, max_streams);
823 
824 	ret = usb_ep_queue(fu->ep_cmd, fu->cmd.req, GFP_ATOMIC);
825 	if (ret)
826 		goto err_free_stream;
827 
828 	return 0;
829 
830 err_free_stream:
831 	uasp_free_cmdreq(fu);
832 
833 err_cleanup:
834 	if (i) {
835 		do {
836 			uasp_cleanup_one_stream(fu, &fu->stream[i - 1]);
837 			i--;
838 		} while (i);
839 	}
840 	pr_err("UASP: endpoint setup failed\n");
841 	return ret;
842 }
843 
844 static void uasp_set_alt(struct f_uas *fu)
845 {
846 	struct usb_function *f = &fu->function;
847 	struct usb_gadget *gadget = f->config->cdev->gadget;
848 	int ret;
849 
850 	fu->flags = USBG_IS_UAS;
851 
852 	if (gadget->speed >= USB_SPEED_SUPER)
853 		fu->flags |= USBG_USE_STREAMS;
854 
855 	config_ep_by_speed_and_alt(gadget, f, fu->ep_in, USB_G_ALT_INT_UAS);
856 	ret = usb_ep_enable(fu->ep_in);
857 	if (ret)
858 		goto err_b_in;
859 
860 	config_ep_by_speed_and_alt(gadget, f, fu->ep_out, USB_G_ALT_INT_UAS);
861 	ret = usb_ep_enable(fu->ep_out);
862 	if (ret)
863 		goto err_b_out;
864 
865 	config_ep_by_speed_and_alt(gadget, f, fu->ep_cmd, USB_G_ALT_INT_UAS);
866 	ret = usb_ep_enable(fu->ep_cmd);
867 	if (ret)
868 		goto err_cmd;
869 	config_ep_by_speed_and_alt(gadget, f, fu->ep_status, USB_G_ALT_INT_UAS);
870 	ret = usb_ep_enable(fu->ep_status);
871 	if (ret)
872 		goto err_status;
873 
874 	ret = uasp_prepare_reqs(fu);
875 	if (ret)
876 		goto err_wq;
877 	fu->flags |= USBG_ENABLED;
878 
879 	pr_info("Using the UAS protocol\n");
880 	return;
881 err_wq:
882 	usb_ep_disable(fu->ep_status);
883 err_status:
884 	usb_ep_disable(fu->ep_cmd);
885 err_cmd:
886 	usb_ep_disable(fu->ep_out);
887 err_b_out:
888 	usb_ep_disable(fu->ep_in);
889 err_b_in:
890 	fu->flags = 0;
891 }
892 
893 static int get_cmd_dir(const unsigned char *cdb)
894 {
895 	int ret;
896 
897 	switch (cdb[0]) {
898 	case READ_6:
899 	case READ_10:
900 	case READ_12:
901 	case READ_16:
902 	case INQUIRY:
903 	case MODE_SENSE:
904 	case MODE_SENSE_10:
905 	case SERVICE_ACTION_IN_16:
906 	case MAINTENANCE_IN:
907 	case PERSISTENT_RESERVE_IN:
908 	case SECURITY_PROTOCOL_IN:
909 	case ACCESS_CONTROL_IN:
910 	case REPORT_LUNS:
911 	case READ_BLOCK_LIMITS:
912 	case READ_POSITION:
913 	case READ_CAPACITY:
914 	case READ_TOC:
915 	case READ_FORMAT_CAPACITIES:
916 	case REQUEST_SENSE:
917 		ret = DMA_FROM_DEVICE;
918 		break;
919 
920 	case WRITE_6:
921 	case WRITE_10:
922 	case WRITE_12:
923 	case WRITE_16:
924 	case MODE_SELECT:
925 	case MODE_SELECT_10:
926 	case WRITE_VERIFY:
927 	case WRITE_VERIFY_12:
928 	case PERSISTENT_RESERVE_OUT:
929 	case MAINTENANCE_OUT:
930 	case SECURITY_PROTOCOL_OUT:
931 	case ACCESS_CONTROL_OUT:
932 		ret = DMA_TO_DEVICE;
933 		break;
934 	case ALLOW_MEDIUM_REMOVAL:
935 	case TEST_UNIT_READY:
936 	case SYNCHRONIZE_CACHE:
937 	case START_STOP:
938 	case ERASE:
939 	case REZERO_UNIT:
940 	case SEEK_10:
941 	case SPACE:
942 	case VERIFY:
943 	case WRITE_FILEMARKS:
944 		ret = DMA_NONE;
945 		break;
946 	default:
947 #define CMD_DIR_MSG "target: Unknown data direction for SCSI Opcode 0x%02x\n"
948 		pr_warn(CMD_DIR_MSG, cdb[0]);
949 #undef CMD_DIR_MSG
950 		ret = -EINVAL;
951 	}
952 	return ret;
953 }
954 
955 static void usbg_data_write_cmpl(struct usb_ep *ep, struct usb_request *req)
956 {
957 	struct usbg_cmd *cmd = req->context;
958 	struct se_cmd *se_cmd = &cmd->se_cmd;
959 
960 	if (req->status < 0) {
961 		pr_err("%s() state %d transfer failed\n", __func__, cmd->state);
962 		goto cleanup;
963 	}
964 
965 	if (req->num_sgs == 0) {
966 		sg_copy_from_buffer(se_cmd->t_data_sg,
967 				se_cmd->t_data_nents,
968 				cmd->data_buf,
969 				se_cmd->data_length);
970 	}
971 
972 	complete(&cmd->write_complete);
973 	return;
974 
975 cleanup:
976 	transport_generic_free_cmd(&cmd->se_cmd, 0);
977 }
978 
979 static int usbg_prepare_w_request(struct usbg_cmd *cmd, struct usb_request *req)
980 {
981 	struct se_cmd *se_cmd = &cmd->se_cmd;
982 	struct f_uas *fu = cmd->fu;
983 	struct usb_gadget *gadget = fuas_to_gadget(fu);
984 
985 	if (!gadget->sg_supported) {
986 		cmd->data_buf = kmalloc(se_cmd->data_length, GFP_ATOMIC);
987 		if (!cmd->data_buf)
988 			return -ENOMEM;
989 
990 		req->buf = cmd->data_buf;
991 	} else {
992 		req->buf = NULL;
993 		req->num_sgs = se_cmd->t_data_nents;
994 		req->sg = se_cmd->t_data_sg;
995 	}
996 
997 	req->is_last = 1;
998 	req->complete = usbg_data_write_cmpl;
999 	req->length = se_cmd->data_length;
1000 	req->context = cmd;
1001 	return 0;
1002 }
1003 
1004 static int usbg_send_status_response(struct se_cmd *se_cmd)
1005 {
1006 	struct usbg_cmd *cmd = container_of(se_cmd, struct usbg_cmd,
1007 			se_cmd);
1008 	struct f_uas *fu = cmd->fu;
1009 
1010 	if (fu->flags & USBG_IS_BOT)
1011 		return bot_send_status_response(cmd);
1012 	else
1013 		return uasp_send_status_response(cmd);
1014 }
1015 
1016 static int usbg_send_write_request(struct se_cmd *se_cmd)
1017 {
1018 	struct usbg_cmd *cmd = container_of(se_cmd, struct usbg_cmd,
1019 			se_cmd);
1020 	struct f_uas *fu = cmd->fu;
1021 
1022 	if (fu->flags & USBG_IS_BOT)
1023 		return bot_send_write_request(cmd);
1024 	else
1025 		return uasp_send_write_request(cmd);
1026 }
1027 
1028 static int usbg_send_read_response(struct se_cmd *se_cmd)
1029 {
1030 	struct usbg_cmd *cmd = container_of(se_cmd, struct usbg_cmd,
1031 			se_cmd);
1032 	struct f_uas *fu = cmd->fu;
1033 
1034 	if (fu->flags & USBG_IS_BOT)
1035 		return bot_send_read_response(cmd);
1036 	else
1037 		return uasp_send_read_response(cmd);
1038 }
1039 
1040 static void usbg_cmd_work(struct work_struct *work)
1041 {
1042 	struct usbg_cmd *cmd = container_of(work, struct usbg_cmd, work);
1043 	struct se_cmd *se_cmd;
1044 	struct tcm_usbg_nexus *tv_nexus;
1045 	struct usbg_tpg *tpg;
1046 	int dir, flags = (TARGET_SCF_UNKNOWN_SIZE | TARGET_SCF_ACK_KREF);
1047 
1048 	se_cmd = &cmd->se_cmd;
1049 	tpg = cmd->fu->tpg;
1050 	tv_nexus = tpg->tpg_nexus;
1051 	dir = get_cmd_dir(cmd->cmd_buf);
1052 	if (dir < 0) {
1053 		__target_init_cmd(se_cmd,
1054 				  tv_nexus->tvn_se_sess->se_tpg->se_tpg_tfo,
1055 				  tv_nexus->tvn_se_sess, cmd->data_len, DMA_NONE,
1056 				  cmd->prio_attr, cmd->sense_iu.sense,
1057 				  cmd->unpacked_lun);
1058 		goto out;
1059 	}
1060 
1061 	target_submit_cmd(se_cmd, tv_nexus->tvn_se_sess, cmd->cmd_buf,
1062 			  cmd->sense_iu.sense, cmd->unpacked_lun, 0,
1063 			  cmd->prio_attr, dir, flags);
1064 	return;
1065 
1066 out:
1067 	transport_send_check_condition_and_sense(se_cmd,
1068 			TCM_UNSUPPORTED_SCSI_OPCODE, 1);
1069 	transport_generic_free_cmd(&cmd->se_cmd, 0);
1070 }
1071 
1072 static struct usbg_cmd *usbg_get_cmd(struct f_uas *fu,
1073 		struct tcm_usbg_nexus *tv_nexus, u32 scsi_tag)
1074 {
1075 	struct se_session *se_sess = tv_nexus->tvn_se_sess;
1076 	struct usbg_cmd *cmd;
1077 	int tag, cpu;
1078 
1079 	tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
1080 	if (tag < 0)
1081 		return ERR_PTR(-ENOMEM);
1082 
1083 	cmd = &((struct usbg_cmd *)se_sess->sess_cmd_map)[tag];
1084 	memset(cmd, 0, sizeof(*cmd));
1085 	cmd->se_cmd.map_tag = tag;
1086 	cmd->se_cmd.map_cpu = cpu;
1087 	cmd->se_cmd.tag = cmd->tag = scsi_tag;
1088 	cmd->fu = fu;
1089 
1090 	return cmd;
1091 }
1092 
1093 static void usbg_release_cmd(struct se_cmd *);
1094 
1095 static int usbg_submit_command(struct f_uas *fu,
1096 		void *cmdbuf, unsigned int len)
1097 {
1098 	struct command_iu *cmd_iu = cmdbuf;
1099 	struct usbg_cmd *cmd;
1100 	struct usbg_tpg *tpg = fu->tpg;
1101 	struct tcm_usbg_nexus *tv_nexus;
1102 	u32 cmd_len;
1103 	u16 scsi_tag;
1104 
1105 	if (cmd_iu->iu_id != IU_ID_COMMAND) {
1106 		pr_err("Unsupported type %d\n", cmd_iu->iu_id);
1107 		return -EINVAL;
1108 	}
1109 
1110 	tv_nexus = tpg->tpg_nexus;
1111 	if (!tv_nexus) {
1112 		pr_err("Missing nexus, ignoring command\n");
1113 		return -EINVAL;
1114 	}
1115 
1116 	cmd_len = (cmd_iu->len & ~0x3) + 16;
1117 	if (cmd_len > USBG_MAX_CMD)
1118 		return -EINVAL;
1119 
1120 	scsi_tag = be16_to_cpup(&cmd_iu->tag);
1121 	cmd = usbg_get_cmd(fu, tv_nexus, scsi_tag);
1122 	if (IS_ERR(cmd)) {
1123 		pr_err("usbg_get_cmd failed\n");
1124 		return -ENOMEM;
1125 	}
1126 	memcpy(cmd->cmd_buf, cmd_iu->cdb, cmd_len);
1127 
1128 	if (fu->flags & USBG_USE_STREAMS) {
1129 		if (cmd->tag > UASP_SS_EP_COMP_NUM_STREAMS)
1130 			goto err;
1131 		if (!cmd->tag)
1132 			cmd->stream = &fu->stream[0];
1133 		else
1134 			cmd->stream = &fu->stream[cmd->tag - 1];
1135 	} else {
1136 		cmd->stream = &fu->stream[0];
1137 	}
1138 
1139 	switch (cmd_iu->prio_attr & 0x7) {
1140 	case UAS_HEAD_TAG:
1141 		cmd->prio_attr = TCM_HEAD_TAG;
1142 		break;
1143 	case UAS_ORDERED_TAG:
1144 		cmd->prio_attr = TCM_ORDERED_TAG;
1145 		break;
1146 	case UAS_ACA:
1147 		cmd->prio_attr = TCM_ACA_TAG;
1148 		break;
1149 	default:
1150 		pr_debug_once("Unsupported prio_attr: %02x.\n",
1151 				cmd_iu->prio_attr);
1152 		fallthrough;
1153 	case UAS_SIMPLE_TAG:
1154 		cmd->prio_attr = TCM_SIMPLE_TAG;
1155 		break;
1156 	}
1157 
1158 	cmd->unpacked_lun = scsilun_to_int(&cmd_iu->lun);
1159 
1160 	INIT_WORK(&cmd->work, usbg_cmd_work);
1161 	queue_work(tpg->workqueue, &cmd->work);
1162 
1163 	return 0;
1164 err:
1165 	usbg_release_cmd(&cmd->se_cmd);
1166 	return -EINVAL;
1167 }
1168 
1169 static void bot_cmd_work(struct work_struct *work)
1170 {
1171 	struct usbg_cmd *cmd = container_of(work, struct usbg_cmd, work);
1172 	struct se_cmd *se_cmd;
1173 	struct tcm_usbg_nexus *tv_nexus;
1174 	struct usbg_tpg *tpg;
1175 	int dir;
1176 
1177 	se_cmd = &cmd->se_cmd;
1178 	tpg = cmd->fu->tpg;
1179 	tv_nexus = tpg->tpg_nexus;
1180 	dir = get_cmd_dir(cmd->cmd_buf);
1181 	if (dir < 0) {
1182 		__target_init_cmd(se_cmd,
1183 				  tv_nexus->tvn_se_sess->se_tpg->se_tpg_tfo,
1184 				  tv_nexus->tvn_se_sess, cmd->data_len, DMA_NONE,
1185 				  cmd->prio_attr, cmd->sense_iu.sense,
1186 				  cmd->unpacked_lun);
1187 		goto out;
1188 	}
1189 
1190 	target_submit_cmd(se_cmd, tv_nexus->tvn_se_sess,
1191 			  cmd->cmd_buf, cmd->sense_iu.sense, cmd->unpacked_lun,
1192 			  cmd->data_len, cmd->prio_attr, dir, 0);
1193 	return;
1194 
1195 out:
1196 	transport_send_check_condition_and_sense(se_cmd,
1197 				TCM_UNSUPPORTED_SCSI_OPCODE, 1);
1198 	transport_generic_free_cmd(&cmd->se_cmd, 0);
1199 }
1200 
1201 static int bot_submit_command(struct f_uas *fu,
1202 		void *cmdbuf, unsigned int len)
1203 {
1204 	struct bulk_cb_wrap *cbw = cmdbuf;
1205 	struct usbg_cmd *cmd;
1206 	struct usbg_tpg *tpg = fu->tpg;
1207 	struct tcm_usbg_nexus *tv_nexus;
1208 	u32 cmd_len;
1209 
1210 	if (cbw->Signature != cpu_to_le32(US_BULK_CB_SIGN)) {
1211 		pr_err("Wrong signature on CBW\n");
1212 		return -EINVAL;
1213 	}
1214 	if (len != 31) {
1215 		pr_err("Wrong length for CBW\n");
1216 		return -EINVAL;
1217 	}
1218 
1219 	cmd_len = cbw->Length;
1220 	if (cmd_len < 1 || cmd_len > 16)
1221 		return -EINVAL;
1222 
1223 	tv_nexus = tpg->tpg_nexus;
1224 	if (!tv_nexus) {
1225 		pr_err("Missing nexus, ignoring command\n");
1226 		return -ENODEV;
1227 	}
1228 
1229 	cmd = usbg_get_cmd(fu, tv_nexus, cbw->Tag);
1230 	if (IS_ERR(cmd)) {
1231 		pr_err("usbg_get_cmd failed\n");
1232 		return -ENOMEM;
1233 	}
1234 	memcpy(cmd->cmd_buf, cbw->CDB, cmd_len);
1235 
1236 	cmd->bot_tag = cbw->Tag;
1237 	cmd->prio_attr = TCM_SIMPLE_TAG;
1238 	cmd->unpacked_lun = cbw->Lun;
1239 	cmd->is_read = cbw->Flags & US_BULK_FLAG_IN ? 1 : 0;
1240 	cmd->data_len = le32_to_cpu(cbw->DataTransferLength);
1241 	cmd->se_cmd.tag = le32_to_cpu(cmd->bot_tag);
1242 
1243 	INIT_WORK(&cmd->work, bot_cmd_work);
1244 	queue_work(tpg->workqueue, &cmd->work);
1245 
1246 	return 0;
1247 }
1248 
1249 /* Start fabric.c code */
1250 
1251 static int usbg_check_true(struct se_portal_group *se_tpg)
1252 {
1253 	return 1;
1254 }
1255 
1256 static int usbg_check_false(struct se_portal_group *se_tpg)
1257 {
1258 	return 0;
1259 }
1260 
1261 static char *usbg_get_fabric_wwn(struct se_portal_group *se_tpg)
1262 {
1263 	struct usbg_tpg *tpg = container_of(se_tpg,
1264 				struct usbg_tpg, se_tpg);
1265 	struct usbg_tport *tport = tpg->tport;
1266 
1267 	return &tport->tport_name[0];
1268 }
1269 
1270 static u16 usbg_get_tag(struct se_portal_group *se_tpg)
1271 {
1272 	struct usbg_tpg *tpg = container_of(se_tpg,
1273 				struct usbg_tpg, se_tpg);
1274 	return tpg->tport_tpgt;
1275 }
1276 
1277 static u32 usbg_tpg_get_inst_index(struct se_portal_group *se_tpg)
1278 {
1279 	return 1;
1280 }
1281 
1282 static void usbg_release_cmd(struct se_cmd *se_cmd)
1283 {
1284 	struct usbg_cmd *cmd = container_of(se_cmd, struct usbg_cmd,
1285 			se_cmd);
1286 	struct se_session *se_sess = se_cmd->se_sess;
1287 
1288 	kfree(cmd->data_buf);
1289 	target_free_tag(se_sess, se_cmd);
1290 }
1291 
1292 static u32 usbg_sess_get_index(struct se_session *se_sess)
1293 {
1294 	return 0;
1295 }
1296 
1297 static void usbg_set_default_node_attrs(struct se_node_acl *nacl)
1298 {
1299 }
1300 
1301 static int usbg_get_cmd_state(struct se_cmd *se_cmd)
1302 {
1303 	return 0;
1304 }
1305 
1306 static void usbg_queue_tm_rsp(struct se_cmd *se_cmd)
1307 {
1308 }
1309 
1310 static void usbg_aborted_task(struct se_cmd *se_cmd)
1311 {
1312 }
1313 
1314 static const char *usbg_check_wwn(const char *name)
1315 {
1316 	const char *n;
1317 	unsigned int len;
1318 
1319 	n = strstr(name, "naa.");
1320 	if (!n)
1321 		return NULL;
1322 	n += 4;
1323 	len = strlen(n);
1324 	if (len == 0 || len > USBG_NAMELEN - 1)
1325 		return NULL;
1326 	return n;
1327 }
1328 
1329 static int usbg_init_nodeacl(struct se_node_acl *se_nacl, const char *name)
1330 {
1331 	if (!usbg_check_wwn(name))
1332 		return -EINVAL;
1333 	return 0;
1334 }
1335 
1336 static struct se_portal_group *usbg_make_tpg(struct se_wwn *wwn,
1337 					     const char *name)
1338 {
1339 	struct usbg_tport *tport = container_of(wwn, struct usbg_tport,
1340 			tport_wwn);
1341 	struct usbg_tpg *tpg;
1342 	unsigned long tpgt;
1343 	int ret;
1344 	struct f_tcm_opts *opts;
1345 	unsigned i;
1346 
1347 	if (strstr(name, "tpgt_") != name)
1348 		return ERR_PTR(-EINVAL);
1349 	if (kstrtoul(name + 5, 0, &tpgt) || tpgt > UINT_MAX)
1350 		return ERR_PTR(-EINVAL);
1351 	ret = -ENODEV;
1352 	mutex_lock(&tpg_instances_lock);
1353 	for (i = 0; i < TPG_INSTANCES; ++i)
1354 		if (tpg_instances[i].func_inst && !tpg_instances[i].tpg)
1355 			break;
1356 	if (i == TPG_INSTANCES)
1357 		goto unlock_inst;
1358 
1359 	opts = container_of(tpg_instances[i].func_inst, struct f_tcm_opts,
1360 		func_inst);
1361 	mutex_lock(&opts->dep_lock);
1362 	if (!opts->ready)
1363 		goto unlock_dep;
1364 
1365 	if (opts->has_dep) {
1366 		if (!try_module_get(opts->dependent))
1367 			goto unlock_dep;
1368 	} else {
1369 		ret = configfs_depend_item_unlocked(
1370 			wwn->wwn_group.cg_subsys,
1371 			&opts->func_inst.group.cg_item);
1372 		if (ret)
1373 			goto unlock_dep;
1374 	}
1375 
1376 	tpg = kzalloc(sizeof(struct usbg_tpg), GFP_KERNEL);
1377 	ret = -ENOMEM;
1378 	if (!tpg)
1379 		goto unref_dep;
1380 	mutex_init(&tpg->tpg_mutex);
1381 	atomic_set(&tpg->tpg_port_count, 0);
1382 	tpg->workqueue = alloc_workqueue("tcm_usb_gadget", 0, 1);
1383 	if (!tpg->workqueue)
1384 		goto free_tpg;
1385 
1386 	tpg->tport = tport;
1387 	tpg->tport_tpgt = tpgt;
1388 
1389 	/*
1390 	 * SPC doesn't assign a protocol identifier for USB-SCSI, so we
1391 	 * pretend to be SAS..
1392 	 */
1393 	ret = core_tpg_register(wwn, &tpg->se_tpg, SCSI_PROTOCOL_SAS);
1394 	if (ret < 0)
1395 		goto free_workqueue;
1396 
1397 	tpg_instances[i].tpg = tpg;
1398 	tpg->fi = tpg_instances[i].func_inst;
1399 	mutex_unlock(&opts->dep_lock);
1400 	mutex_unlock(&tpg_instances_lock);
1401 	return &tpg->se_tpg;
1402 
1403 free_workqueue:
1404 	destroy_workqueue(tpg->workqueue);
1405 free_tpg:
1406 	kfree(tpg);
1407 unref_dep:
1408 	if (opts->has_dep)
1409 		module_put(opts->dependent);
1410 	else
1411 		configfs_undepend_item_unlocked(&opts->func_inst.group.cg_item);
1412 unlock_dep:
1413 	mutex_unlock(&opts->dep_lock);
1414 unlock_inst:
1415 	mutex_unlock(&tpg_instances_lock);
1416 
1417 	return ERR_PTR(ret);
1418 }
1419 
1420 static int tcm_usbg_drop_nexus(struct usbg_tpg *);
1421 
1422 static void usbg_drop_tpg(struct se_portal_group *se_tpg)
1423 {
1424 	struct usbg_tpg *tpg = container_of(se_tpg,
1425 				struct usbg_tpg, se_tpg);
1426 	unsigned i;
1427 	struct f_tcm_opts *opts;
1428 
1429 	tcm_usbg_drop_nexus(tpg);
1430 	core_tpg_deregister(se_tpg);
1431 	destroy_workqueue(tpg->workqueue);
1432 
1433 	mutex_lock(&tpg_instances_lock);
1434 	for (i = 0; i < TPG_INSTANCES; ++i)
1435 		if (tpg_instances[i].tpg == tpg)
1436 			break;
1437 	if (i < TPG_INSTANCES) {
1438 		tpg_instances[i].tpg = NULL;
1439 		opts = container_of(tpg_instances[i].func_inst,
1440 			struct f_tcm_opts, func_inst);
1441 		mutex_lock(&opts->dep_lock);
1442 		if (opts->has_dep)
1443 			module_put(opts->dependent);
1444 		else
1445 			configfs_undepend_item_unlocked(
1446 				&opts->func_inst.group.cg_item);
1447 		mutex_unlock(&opts->dep_lock);
1448 	}
1449 	mutex_unlock(&tpg_instances_lock);
1450 
1451 	kfree(tpg);
1452 }
1453 
1454 static struct se_wwn *usbg_make_tport(
1455 	struct target_fabric_configfs *tf,
1456 	struct config_group *group,
1457 	const char *name)
1458 {
1459 	struct usbg_tport *tport;
1460 	const char *wnn_name;
1461 	u64 wwpn = 0;
1462 
1463 	wnn_name = usbg_check_wwn(name);
1464 	if (!wnn_name)
1465 		return ERR_PTR(-EINVAL);
1466 
1467 	tport = kzalloc(sizeof(struct usbg_tport), GFP_KERNEL);
1468 	if (!(tport))
1469 		return ERR_PTR(-ENOMEM);
1470 
1471 	tport->tport_wwpn = wwpn;
1472 	snprintf(tport->tport_name, sizeof(tport->tport_name), "%s", wnn_name);
1473 	return &tport->tport_wwn;
1474 }
1475 
1476 static void usbg_drop_tport(struct se_wwn *wwn)
1477 {
1478 	struct usbg_tport *tport = container_of(wwn,
1479 				struct usbg_tport, tport_wwn);
1480 	kfree(tport);
1481 }
1482 
1483 /*
1484  * If somebody feels like dropping the version property, go ahead.
1485  */
1486 static ssize_t usbg_wwn_version_show(struct config_item *item,  char *page)
1487 {
1488 	return sprintf(page, "usb-gadget fabric module\n");
1489 }
1490 
1491 CONFIGFS_ATTR_RO(usbg_wwn_, version);
1492 
1493 static struct configfs_attribute *usbg_wwn_attrs[] = {
1494 	&usbg_wwn_attr_version,
1495 	NULL,
1496 };
1497 
1498 static int usbg_attach(struct usbg_tpg *);
1499 static void usbg_detach(struct usbg_tpg *);
1500 
1501 static int usbg_enable_tpg(struct se_portal_group *se_tpg, bool enable)
1502 {
1503 	struct usbg_tpg  *tpg = container_of(se_tpg, struct usbg_tpg, se_tpg);
1504 	int ret = 0;
1505 
1506 	if (enable)
1507 		ret = usbg_attach(tpg);
1508 	else
1509 		usbg_detach(tpg);
1510 	if (ret)
1511 		return ret;
1512 
1513 	tpg->gadget_connect = enable;
1514 
1515 	return 0;
1516 }
1517 
1518 static ssize_t tcm_usbg_tpg_nexus_show(struct config_item *item, char *page)
1519 {
1520 	struct se_portal_group *se_tpg = to_tpg(item);
1521 	struct usbg_tpg *tpg = container_of(se_tpg, struct usbg_tpg, se_tpg);
1522 	struct tcm_usbg_nexus *tv_nexus;
1523 	ssize_t ret;
1524 
1525 	mutex_lock(&tpg->tpg_mutex);
1526 	tv_nexus = tpg->tpg_nexus;
1527 	if (!tv_nexus) {
1528 		ret = -ENODEV;
1529 		goto out;
1530 	}
1531 	ret = snprintf(page, PAGE_SIZE, "%s\n",
1532 			tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1533 out:
1534 	mutex_unlock(&tpg->tpg_mutex);
1535 	return ret;
1536 }
1537 
1538 static int usbg_alloc_sess_cb(struct se_portal_group *se_tpg,
1539 			      struct se_session *se_sess, void *p)
1540 {
1541 	struct usbg_tpg *tpg = container_of(se_tpg,
1542 				struct usbg_tpg, se_tpg);
1543 
1544 	tpg->tpg_nexus = p;
1545 	return 0;
1546 }
1547 
1548 static int tcm_usbg_make_nexus(struct usbg_tpg *tpg, char *name)
1549 {
1550 	struct tcm_usbg_nexus *tv_nexus;
1551 	int ret = 0;
1552 
1553 	mutex_lock(&tpg->tpg_mutex);
1554 	if (tpg->tpg_nexus) {
1555 		ret = -EEXIST;
1556 		pr_debug("tpg->tpg_nexus already exists\n");
1557 		goto out_unlock;
1558 	}
1559 
1560 	tv_nexus = kzalloc(sizeof(*tv_nexus), GFP_KERNEL);
1561 	if (!tv_nexus) {
1562 		ret = -ENOMEM;
1563 		goto out_unlock;
1564 	}
1565 
1566 	tv_nexus->tvn_se_sess = target_setup_session(&tpg->se_tpg,
1567 						     USB_G_DEFAULT_SESSION_TAGS,
1568 						     sizeof(struct usbg_cmd),
1569 						     TARGET_PROT_NORMAL, name,
1570 						     tv_nexus, usbg_alloc_sess_cb);
1571 	if (IS_ERR(tv_nexus->tvn_se_sess)) {
1572 #define MAKE_NEXUS_MSG "core_tpg_check_initiator_node_acl() failed for %s\n"
1573 		pr_debug(MAKE_NEXUS_MSG, name);
1574 #undef MAKE_NEXUS_MSG
1575 		ret = PTR_ERR(tv_nexus->tvn_se_sess);
1576 		kfree(tv_nexus);
1577 	}
1578 
1579 out_unlock:
1580 	mutex_unlock(&tpg->tpg_mutex);
1581 	return ret;
1582 }
1583 
1584 static int tcm_usbg_drop_nexus(struct usbg_tpg *tpg)
1585 {
1586 	struct se_session *se_sess;
1587 	struct tcm_usbg_nexus *tv_nexus;
1588 	int ret = -ENODEV;
1589 
1590 	mutex_lock(&tpg->tpg_mutex);
1591 	tv_nexus = tpg->tpg_nexus;
1592 	if (!tv_nexus)
1593 		goto out;
1594 
1595 	se_sess = tv_nexus->tvn_se_sess;
1596 	if (!se_sess)
1597 		goto out;
1598 
1599 	if (atomic_read(&tpg->tpg_port_count)) {
1600 		ret = -EPERM;
1601 #define MSG "Unable to remove Host I_T Nexus with active TPG port count: %d\n"
1602 		pr_err(MSG, atomic_read(&tpg->tpg_port_count));
1603 #undef MSG
1604 		goto out;
1605 	}
1606 
1607 	pr_debug("Removing I_T Nexus to Initiator Port: %s\n",
1608 			tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1609 	/*
1610 	 * Release the SCSI I_T Nexus to the emulated vHost Target Port
1611 	 */
1612 	target_remove_session(se_sess);
1613 	tpg->tpg_nexus = NULL;
1614 
1615 	kfree(tv_nexus);
1616 	ret = 0;
1617 out:
1618 	mutex_unlock(&tpg->tpg_mutex);
1619 	return ret;
1620 }
1621 
1622 static ssize_t tcm_usbg_tpg_nexus_store(struct config_item *item,
1623 		const char *page, size_t count)
1624 {
1625 	struct se_portal_group *se_tpg = to_tpg(item);
1626 	struct usbg_tpg *tpg = container_of(se_tpg, struct usbg_tpg, se_tpg);
1627 	unsigned char i_port[USBG_NAMELEN], *ptr;
1628 	int ret;
1629 
1630 	if (!strncmp(page, "NULL", 4)) {
1631 		ret = tcm_usbg_drop_nexus(tpg);
1632 		return (!ret) ? count : ret;
1633 	}
1634 	if (strlen(page) >= USBG_NAMELEN) {
1635 
1636 #define NEXUS_STORE_MSG "Emulated NAA Sas Address: %s, exceeds max: %d\n"
1637 		pr_err(NEXUS_STORE_MSG, page, USBG_NAMELEN);
1638 #undef NEXUS_STORE_MSG
1639 		return -EINVAL;
1640 	}
1641 	snprintf(i_port, USBG_NAMELEN, "%s", page);
1642 
1643 	ptr = strstr(i_port, "naa.");
1644 	if (!ptr) {
1645 		pr_err("Missing 'naa.' prefix\n");
1646 		return -EINVAL;
1647 	}
1648 
1649 	if (i_port[strlen(i_port) - 1] == '\n')
1650 		i_port[strlen(i_port) - 1] = '\0';
1651 
1652 	ret = tcm_usbg_make_nexus(tpg, &i_port[0]);
1653 	if (ret < 0)
1654 		return ret;
1655 	return count;
1656 }
1657 
1658 CONFIGFS_ATTR(tcm_usbg_tpg_, nexus);
1659 
1660 static struct configfs_attribute *usbg_base_attrs[] = {
1661 	&tcm_usbg_tpg_attr_nexus,
1662 	NULL,
1663 };
1664 
1665 static int usbg_port_link(struct se_portal_group *se_tpg, struct se_lun *lun)
1666 {
1667 	struct usbg_tpg *tpg = container_of(se_tpg, struct usbg_tpg, se_tpg);
1668 
1669 	atomic_inc(&tpg->tpg_port_count);
1670 	smp_mb__after_atomic();
1671 	return 0;
1672 }
1673 
1674 static void usbg_port_unlink(struct se_portal_group *se_tpg,
1675 		struct se_lun *se_lun)
1676 {
1677 	struct usbg_tpg *tpg = container_of(se_tpg, struct usbg_tpg, se_tpg);
1678 
1679 	atomic_dec(&tpg->tpg_port_count);
1680 	smp_mb__after_atomic();
1681 }
1682 
1683 static int usbg_check_stop_free(struct se_cmd *se_cmd)
1684 {
1685 	return target_put_sess_cmd(se_cmd);
1686 }
1687 
1688 static const struct target_core_fabric_ops usbg_ops = {
1689 	.module				= THIS_MODULE,
1690 	.fabric_name			= "usb_gadget",
1691 	.tpg_get_wwn			= usbg_get_fabric_wwn,
1692 	.tpg_get_tag			= usbg_get_tag,
1693 	.tpg_check_demo_mode		= usbg_check_true,
1694 	.tpg_check_demo_mode_cache	= usbg_check_false,
1695 	.tpg_check_demo_mode_write_protect = usbg_check_false,
1696 	.tpg_check_prod_mode_write_protect = usbg_check_false,
1697 	.tpg_get_inst_index		= usbg_tpg_get_inst_index,
1698 	.release_cmd			= usbg_release_cmd,
1699 	.sess_get_index			= usbg_sess_get_index,
1700 	.sess_get_initiator_sid		= NULL,
1701 	.write_pending			= usbg_send_write_request,
1702 	.set_default_node_attributes	= usbg_set_default_node_attrs,
1703 	.get_cmd_state			= usbg_get_cmd_state,
1704 	.queue_data_in			= usbg_send_read_response,
1705 	.queue_status			= usbg_send_status_response,
1706 	.queue_tm_rsp			= usbg_queue_tm_rsp,
1707 	.aborted_task			= usbg_aborted_task,
1708 	.check_stop_free		= usbg_check_stop_free,
1709 
1710 	.fabric_make_wwn		= usbg_make_tport,
1711 	.fabric_drop_wwn		= usbg_drop_tport,
1712 	.fabric_make_tpg		= usbg_make_tpg,
1713 	.fabric_enable_tpg		= usbg_enable_tpg,
1714 	.fabric_drop_tpg		= usbg_drop_tpg,
1715 	.fabric_post_link		= usbg_port_link,
1716 	.fabric_pre_unlink		= usbg_port_unlink,
1717 	.fabric_init_nodeacl		= usbg_init_nodeacl,
1718 
1719 	.tfc_wwn_attrs			= usbg_wwn_attrs,
1720 	.tfc_tpg_base_attrs		= usbg_base_attrs,
1721 };
1722 
1723 /* Start gadget.c code */
1724 
1725 static struct usb_interface_descriptor bot_intf_desc = {
1726 	.bLength =              sizeof(bot_intf_desc),
1727 	.bDescriptorType =      USB_DT_INTERFACE,
1728 	.bNumEndpoints =        2,
1729 	.bAlternateSetting =	USB_G_ALT_INT_BBB,
1730 	.bInterfaceClass =      USB_CLASS_MASS_STORAGE,
1731 	.bInterfaceSubClass =   USB_SC_SCSI,
1732 	.bInterfaceProtocol =   USB_PR_BULK,
1733 };
1734 
1735 static struct usb_interface_descriptor uasp_intf_desc = {
1736 	.bLength =		sizeof(uasp_intf_desc),
1737 	.bDescriptorType =	USB_DT_INTERFACE,
1738 	.bNumEndpoints =	4,
1739 	.bAlternateSetting =	USB_G_ALT_INT_UAS,
1740 	.bInterfaceClass =	USB_CLASS_MASS_STORAGE,
1741 	.bInterfaceSubClass =	USB_SC_SCSI,
1742 	.bInterfaceProtocol =	USB_PR_UAS,
1743 };
1744 
1745 static struct usb_endpoint_descriptor uasp_bi_desc = {
1746 	.bLength =		USB_DT_ENDPOINT_SIZE,
1747 	.bDescriptorType =	USB_DT_ENDPOINT,
1748 	.bEndpointAddress =	USB_DIR_IN,
1749 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
1750 	.wMaxPacketSize =	cpu_to_le16(512),
1751 };
1752 
1753 static struct usb_endpoint_descriptor uasp_fs_bi_desc = {
1754 	.bLength =		USB_DT_ENDPOINT_SIZE,
1755 	.bDescriptorType =	USB_DT_ENDPOINT,
1756 	.bEndpointAddress =	USB_DIR_IN,
1757 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
1758 };
1759 
1760 static struct usb_pipe_usage_descriptor uasp_bi_pipe_desc = {
1761 	.bLength =		sizeof(uasp_bi_pipe_desc),
1762 	.bDescriptorType =	USB_DT_PIPE_USAGE,
1763 	.bPipeID =		DATA_IN_PIPE_ID,
1764 };
1765 
1766 static struct usb_endpoint_descriptor uasp_ss_bi_desc = {
1767 	.bLength =		USB_DT_ENDPOINT_SIZE,
1768 	.bDescriptorType =	USB_DT_ENDPOINT,
1769 	.bEndpointAddress =	USB_DIR_IN,
1770 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
1771 	.wMaxPacketSize =	cpu_to_le16(1024),
1772 };
1773 
1774 static struct usb_ss_ep_comp_descriptor uasp_bi_ep_comp_desc = {
1775 	.bLength =		sizeof(uasp_bi_ep_comp_desc),
1776 	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
1777 	.bMaxBurst =		0,
1778 	.bmAttributes =		UASP_SS_EP_COMP_LOG_STREAMS,
1779 	.wBytesPerInterval =	0,
1780 };
1781 
1782 static struct usb_ss_ep_comp_descriptor bot_bi_ep_comp_desc = {
1783 	.bLength =		sizeof(bot_bi_ep_comp_desc),
1784 	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
1785 	.bMaxBurst =		0,
1786 };
1787 
1788 static struct usb_endpoint_descriptor uasp_bo_desc = {
1789 	.bLength =		USB_DT_ENDPOINT_SIZE,
1790 	.bDescriptorType =	USB_DT_ENDPOINT,
1791 	.bEndpointAddress =	USB_DIR_OUT,
1792 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
1793 	.wMaxPacketSize =	cpu_to_le16(512),
1794 };
1795 
1796 static struct usb_endpoint_descriptor uasp_fs_bo_desc = {
1797 	.bLength =		USB_DT_ENDPOINT_SIZE,
1798 	.bDescriptorType =	USB_DT_ENDPOINT,
1799 	.bEndpointAddress =	USB_DIR_OUT,
1800 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
1801 };
1802 
1803 static struct usb_pipe_usage_descriptor uasp_bo_pipe_desc = {
1804 	.bLength =		sizeof(uasp_bo_pipe_desc),
1805 	.bDescriptorType =	USB_DT_PIPE_USAGE,
1806 	.bPipeID =		DATA_OUT_PIPE_ID,
1807 };
1808 
1809 static struct usb_endpoint_descriptor uasp_ss_bo_desc = {
1810 	.bLength =		USB_DT_ENDPOINT_SIZE,
1811 	.bDescriptorType =	USB_DT_ENDPOINT,
1812 	.bEndpointAddress =	USB_DIR_OUT,
1813 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
1814 	.wMaxPacketSize =	cpu_to_le16(0x400),
1815 };
1816 
1817 static struct usb_ss_ep_comp_descriptor uasp_bo_ep_comp_desc = {
1818 	.bLength =		sizeof(uasp_bo_ep_comp_desc),
1819 	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
1820 	.bmAttributes =		UASP_SS_EP_COMP_LOG_STREAMS,
1821 };
1822 
1823 static struct usb_ss_ep_comp_descriptor bot_bo_ep_comp_desc = {
1824 	.bLength =		sizeof(bot_bo_ep_comp_desc),
1825 	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
1826 };
1827 
1828 static struct usb_endpoint_descriptor uasp_status_desc = {
1829 	.bLength =		USB_DT_ENDPOINT_SIZE,
1830 	.bDescriptorType =	USB_DT_ENDPOINT,
1831 	.bEndpointAddress =	USB_DIR_IN,
1832 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
1833 	.wMaxPacketSize =	cpu_to_le16(512),
1834 };
1835 
1836 static struct usb_endpoint_descriptor uasp_fs_status_desc = {
1837 	.bLength =		USB_DT_ENDPOINT_SIZE,
1838 	.bDescriptorType =	USB_DT_ENDPOINT,
1839 	.bEndpointAddress =	USB_DIR_IN,
1840 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
1841 };
1842 
1843 static struct usb_pipe_usage_descriptor uasp_status_pipe_desc = {
1844 	.bLength =		sizeof(uasp_status_pipe_desc),
1845 	.bDescriptorType =	USB_DT_PIPE_USAGE,
1846 	.bPipeID =		STATUS_PIPE_ID,
1847 };
1848 
1849 static struct usb_endpoint_descriptor uasp_ss_status_desc = {
1850 	.bLength =		USB_DT_ENDPOINT_SIZE,
1851 	.bDescriptorType =	USB_DT_ENDPOINT,
1852 	.bEndpointAddress =	USB_DIR_IN,
1853 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
1854 	.wMaxPacketSize =	cpu_to_le16(1024),
1855 };
1856 
1857 static struct usb_ss_ep_comp_descriptor uasp_status_in_ep_comp_desc = {
1858 	.bLength =		sizeof(uasp_status_in_ep_comp_desc),
1859 	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
1860 	.bmAttributes =		UASP_SS_EP_COMP_LOG_STREAMS,
1861 };
1862 
1863 static struct usb_endpoint_descriptor uasp_cmd_desc = {
1864 	.bLength =		USB_DT_ENDPOINT_SIZE,
1865 	.bDescriptorType =	USB_DT_ENDPOINT,
1866 	.bEndpointAddress =	USB_DIR_OUT,
1867 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
1868 	.wMaxPacketSize =	cpu_to_le16(512),
1869 };
1870 
1871 static struct usb_endpoint_descriptor uasp_fs_cmd_desc = {
1872 	.bLength =		USB_DT_ENDPOINT_SIZE,
1873 	.bDescriptorType =	USB_DT_ENDPOINT,
1874 	.bEndpointAddress =	USB_DIR_OUT,
1875 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
1876 };
1877 
1878 static struct usb_pipe_usage_descriptor uasp_cmd_pipe_desc = {
1879 	.bLength =		sizeof(uasp_cmd_pipe_desc),
1880 	.bDescriptorType =	USB_DT_PIPE_USAGE,
1881 	.bPipeID =		CMD_PIPE_ID,
1882 };
1883 
1884 static struct usb_endpoint_descriptor uasp_ss_cmd_desc = {
1885 	.bLength =		USB_DT_ENDPOINT_SIZE,
1886 	.bDescriptorType =	USB_DT_ENDPOINT,
1887 	.bEndpointAddress =	USB_DIR_OUT,
1888 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
1889 	.wMaxPacketSize =	cpu_to_le16(1024),
1890 };
1891 
1892 static struct usb_ss_ep_comp_descriptor uasp_cmd_comp_desc = {
1893 	.bLength =		sizeof(uasp_cmd_comp_desc),
1894 	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
1895 };
1896 
1897 static struct usb_descriptor_header *uasp_fs_function_desc[] = {
1898 	(struct usb_descriptor_header *) &bot_intf_desc,
1899 	(struct usb_descriptor_header *) &uasp_fs_bi_desc,
1900 	(struct usb_descriptor_header *) &uasp_fs_bo_desc,
1901 
1902 	(struct usb_descriptor_header *) &uasp_intf_desc,
1903 	(struct usb_descriptor_header *) &uasp_fs_bi_desc,
1904 	(struct usb_descriptor_header *) &uasp_bi_pipe_desc,
1905 	(struct usb_descriptor_header *) &uasp_fs_bo_desc,
1906 	(struct usb_descriptor_header *) &uasp_bo_pipe_desc,
1907 	(struct usb_descriptor_header *) &uasp_fs_status_desc,
1908 	(struct usb_descriptor_header *) &uasp_status_pipe_desc,
1909 	(struct usb_descriptor_header *) &uasp_fs_cmd_desc,
1910 	(struct usb_descriptor_header *) &uasp_cmd_pipe_desc,
1911 	NULL,
1912 };
1913 
1914 static struct usb_descriptor_header *uasp_hs_function_desc[] = {
1915 	(struct usb_descriptor_header *) &bot_intf_desc,
1916 	(struct usb_descriptor_header *) &uasp_bi_desc,
1917 	(struct usb_descriptor_header *) &uasp_bo_desc,
1918 
1919 	(struct usb_descriptor_header *) &uasp_intf_desc,
1920 	(struct usb_descriptor_header *) &uasp_bi_desc,
1921 	(struct usb_descriptor_header *) &uasp_bi_pipe_desc,
1922 	(struct usb_descriptor_header *) &uasp_bo_desc,
1923 	(struct usb_descriptor_header *) &uasp_bo_pipe_desc,
1924 	(struct usb_descriptor_header *) &uasp_status_desc,
1925 	(struct usb_descriptor_header *) &uasp_status_pipe_desc,
1926 	(struct usb_descriptor_header *) &uasp_cmd_desc,
1927 	(struct usb_descriptor_header *) &uasp_cmd_pipe_desc,
1928 	NULL,
1929 };
1930 
1931 static struct usb_descriptor_header *uasp_ss_function_desc[] = {
1932 	(struct usb_descriptor_header *) &bot_intf_desc,
1933 	(struct usb_descriptor_header *) &uasp_ss_bi_desc,
1934 	(struct usb_descriptor_header *) &bot_bi_ep_comp_desc,
1935 	(struct usb_descriptor_header *) &uasp_ss_bo_desc,
1936 	(struct usb_descriptor_header *) &bot_bo_ep_comp_desc,
1937 
1938 	(struct usb_descriptor_header *) &uasp_intf_desc,
1939 	(struct usb_descriptor_header *) &uasp_ss_bi_desc,
1940 	(struct usb_descriptor_header *) &uasp_bi_ep_comp_desc,
1941 	(struct usb_descriptor_header *) &uasp_bi_pipe_desc,
1942 	(struct usb_descriptor_header *) &uasp_ss_bo_desc,
1943 	(struct usb_descriptor_header *) &uasp_bo_ep_comp_desc,
1944 	(struct usb_descriptor_header *) &uasp_bo_pipe_desc,
1945 	(struct usb_descriptor_header *) &uasp_ss_status_desc,
1946 	(struct usb_descriptor_header *) &uasp_status_in_ep_comp_desc,
1947 	(struct usb_descriptor_header *) &uasp_status_pipe_desc,
1948 	(struct usb_descriptor_header *) &uasp_ss_cmd_desc,
1949 	(struct usb_descriptor_header *) &uasp_cmd_comp_desc,
1950 	(struct usb_descriptor_header *) &uasp_cmd_pipe_desc,
1951 	NULL,
1952 };
1953 
1954 static struct usb_string	tcm_us_strings[] = {
1955 	[USB_G_STR_INT_UAS].s		= "USB Attached SCSI",
1956 	[USB_G_STR_INT_BBB].s		= "Bulk Only Transport",
1957 	{ },
1958 };
1959 
1960 static struct usb_gadget_strings tcm_stringtab = {
1961 	.language = 0x0409,
1962 	.strings = tcm_us_strings,
1963 };
1964 
1965 static struct usb_gadget_strings *tcm_strings[] = {
1966 	&tcm_stringtab,
1967 	NULL,
1968 };
1969 
1970 static int tcm_bind(struct usb_configuration *c, struct usb_function *f)
1971 {
1972 	struct f_uas		*fu = to_f_uas(f);
1973 	struct usb_string	*us;
1974 	struct usb_gadget	*gadget = c->cdev->gadget;
1975 	struct usb_ep		*ep;
1976 	struct f_tcm_opts	*opts;
1977 	int			iface;
1978 	int			ret;
1979 
1980 	opts = container_of(f->fi, struct f_tcm_opts, func_inst);
1981 
1982 	mutex_lock(&opts->dep_lock);
1983 	if (!opts->can_attach) {
1984 		mutex_unlock(&opts->dep_lock);
1985 		return -ENODEV;
1986 	}
1987 	mutex_unlock(&opts->dep_lock);
1988 	us = usb_gstrings_attach(c->cdev, tcm_strings,
1989 		ARRAY_SIZE(tcm_us_strings));
1990 	if (IS_ERR(us))
1991 		return PTR_ERR(us);
1992 	bot_intf_desc.iInterface = us[USB_G_STR_INT_BBB].id;
1993 	uasp_intf_desc.iInterface = us[USB_G_STR_INT_UAS].id;
1994 
1995 	iface = usb_interface_id(c, f);
1996 	if (iface < 0)
1997 		return iface;
1998 
1999 	bot_intf_desc.bInterfaceNumber = iface;
2000 	uasp_intf_desc.bInterfaceNumber = iface;
2001 	fu->iface = iface;
2002 	ep = usb_ep_autoconfig_ss(gadget, &uasp_ss_bi_desc,
2003 			&uasp_bi_ep_comp_desc);
2004 	if (!ep)
2005 		goto ep_fail;
2006 
2007 	fu->ep_in = ep;
2008 
2009 	ep = usb_ep_autoconfig_ss(gadget, &uasp_ss_bo_desc,
2010 			&uasp_bo_ep_comp_desc);
2011 	if (!ep)
2012 		goto ep_fail;
2013 	fu->ep_out = ep;
2014 
2015 	ep = usb_ep_autoconfig_ss(gadget, &uasp_ss_status_desc,
2016 			&uasp_status_in_ep_comp_desc);
2017 	if (!ep)
2018 		goto ep_fail;
2019 	fu->ep_status = ep;
2020 
2021 	ep = usb_ep_autoconfig_ss(gadget, &uasp_ss_cmd_desc,
2022 			&uasp_cmd_comp_desc);
2023 	if (!ep)
2024 		goto ep_fail;
2025 	fu->ep_cmd = ep;
2026 
2027 	/* Assume endpoint addresses are the same for both speeds */
2028 	uasp_bi_desc.bEndpointAddress =	uasp_ss_bi_desc.bEndpointAddress;
2029 	uasp_bo_desc.bEndpointAddress = uasp_ss_bo_desc.bEndpointAddress;
2030 	uasp_status_desc.bEndpointAddress =
2031 		uasp_ss_status_desc.bEndpointAddress;
2032 	uasp_cmd_desc.bEndpointAddress = uasp_ss_cmd_desc.bEndpointAddress;
2033 
2034 	uasp_fs_bi_desc.bEndpointAddress = uasp_ss_bi_desc.bEndpointAddress;
2035 	uasp_fs_bo_desc.bEndpointAddress = uasp_ss_bo_desc.bEndpointAddress;
2036 	uasp_fs_status_desc.bEndpointAddress =
2037 		uasp_ss_status_desc.bEndpointAddress;
2038 	uasp_fs_cmd_desc.bEndpointAddress = uasp_ss_cmd_desc.bEndpointAddress;
2039 
2040 	ret = usb_assign_descriptors(f, uasp_fs_function_desc,
2041 			uasp_hs_function_desc, uasp_ss_function_desc,
2042 			uasp_ss_function_desc);
2043 	if (ret)
2044 		goto ep_fail;
2045 
2046 	return 0;
2047 ep_fail:
2048 	pr_err("Can't claim all required eps\n");
2049 
2050 	return -ENOTSUPP;
2051 }
2052 
2053 struct guas_setup_wq {
2054 	struct work_struct work;
2055 	struct f_uas *fu;
2056 	unsigned int alt;
2057 };
2058 
2059 static void tcm_delayed_set_alt(struct work_struct *wq)
2060 {
2061 	struct guas_setup_wq *work = container_of(wq, struct guas_setup_wq,
2062 			work);
2063 	struct f_uas *fu = work->fu;
2064 	int alt = work->alt;
2065 
2066 	kfree(work);
2067 
2068 	if (fu->flags & USBG_IS_BOT)
2069 		bot_cleanup_old_alt(fu);
2070 	if (fu->flags & USBG_IS_UAS)
2071 		uasp_cleanup_old_alt(fu);
2072 
2073 	if (alt == USB_G_ALT_INT_BBB)
2074 		bot_set_alt(fu);
2075 	else if (alt == USB_G_ALT_INT_UAS)
2076 		uasp_set_alt(fu);
2077 	usb_composite_setup_continue(fu->function.config->cdev);
2078 }
2079 
2080 static int tcm_get_alt(struct usb_function *f, unsigned intf)
2081 {
2082 	if (intf == bot_intf_desc.bInterfaceNumber)
2083 		return USB_G_ALT_INT_BBB;
2084 	if (intf == uasp_intf_desc.bInterfaceNumber)
2085 		return USB_G_ALT_INT_UAS;
2086 
2087 	return -EOPNOTSUPP;
2088 }
2089 
2090 static int tcm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
2091 {
2092 	struct f_uas *fu = to_f_uas(f);
2093 
2094 	if ((alt == USB_G_ALT_INT_BBB) || (alt == USB_G_ALT_INT_UAS)) {
2095 		struct guas_setup_wq *work;
2096 
2097 		work = kmalloc(sizeof(*work), GFP_ATOMIC);
2098 		if (!work)
2099 			return -ENOMEM;
2100 		INIT_WORK(&work->work, tcm_delayed_set_alt);
2101 		work->fu = fu;
2102 		work->alt = alt;
2103 		schedule_work(&work->work);
2104 		return USB_GADGET_DELAYED_STATUS;
2105 	}
2106 	return -EOPNOTSUPP;
2107 }
2108 
2109 static void tcm_disable(struct usb_function *f)
2110 {
2111 	struct f_uas *fu = to_f_uas(f);
2112 
2113 	if (fu->flags & USBG_IS_UAS)
2114 		uasp_cleanup_old_alt(fu);
2115 	else if (fu->flags & USBG_IS_BOT)
2116 		bot_cleanup_old_alt(fu);
2117 	fu->flags = 0;
2118 }
2119 
2120 static int tcm_setup(struct usb_function *f,
2121 		const struct usb_ctrlrequest *ctrl)
2122 {
2123 	struct f_uas *fu = to_f_uas(f);
2124 
2125 	if (!(fu->flags & USBG_IS_BOT))
2126 		return -EOPNOTSUPP;
2127 
2128 	return usbg_bot_setup(f, ctrl);
2129 }
2130 
2131 static inline struct f_tcm_opts *to_f_tcm_opts(struct config_item *item)
2132 {
2133 	return container_of(to_config_group(item), struct f_tcm_opts,
2134 		func_inst.group);
2135 }
2136 
2137 static void tcm_attr_release(struct config_item *item)
2138 {
2139 	struct f_tcm_opts *opts = to_f_tcm_opts(item);
2140 
2141 	usb_put_function_instance(&opts->func_inst);
2142 }
2143 
2144 static struct configfs_item_operations tcm_item_ops = {
2145 	.release		= tcm_attr_release,
2146 };
2147 
2148 static const struct config_item_type tcm_func_type = {
2149 	.ct_item_ops	= &tcm_item_ops,
2150 	.ct_owner	= THIS_MODULE,
2151 };
2152 
2153 static void tcm_free_inst(struct usb_function_instance *f)
2154 {
2155 	struct f_tcm_opts *opts;
2156 	unsigned i;
2157 
2158 	opts = container_of(f, struct f_tcm_opts, func_inst);
2159 
2160 	mutex_lock(&tpg_instances_lock);
2161 	for (i = 0; i < TPG_INSTANCES; ++i)
2162 		if (tpg_instances[i].func_inst == f)
2163 			break;
2164 	if (i < TPG_INSTANCES)
2165 		tpg_instances[i].func_inst = NULL;
2166 	mutex_unlock(&tpg_instances_lock);
2167 
2168 	kfree(opts);
2169 }
2170 
2171 static int tcm_register_callback(struct usb_function_instance *f)
2172 {
2173 	struct f_tcm_opts *opts = container_of(f, struct f_tcm_opts, func_inst);
2174 
2175 	mutex_lock(&opts->dep_lock);
2176 	opts->can_attach = true;
2177 	mutex_unlock(&opts->dep_lock);
2178 
2179 	return 0;
2180 }
2181 
2182 static void tcm_unregister_callback(struct usb_function_instance *f)
2183 {
2184 	struct f_tcm_opts *opts = container_of(f, struct f_tcm_opts, func_inst);
2185 
2186 	mutex_lock(&opts->dep_lock);
2187 	unregister_gadget_item(opts->
2188 		func_inst.group.cg_item.ci_parent->ci_parent);
2189 	opts->can_attach = false;
2190 	mutex_unlock(&opts->dep_lock);
2191 }
2192 
2193 static int usbg_attach(struct usbg_tpg *tpg)
2194 {
2195 	struct usb_function_instance *f = tpg->fi;
2196 	struct f_tcm_opts *opts = container_of(f, struct f_tcm_opts, func_inst);
2197 
2198 	if (opts->tcm_register_callback)
2199 		return opts->tcm_register_callback(f);
2200 
2201 	return 0;
2202 }
2203 
2204 static void usbg_detach(struct usbg_tpg *tpg)
2205 {
2206 	struct usb_function_instance *f = tpg->fi;
2207 	struct f_tcm_opts *opts = container_of(f, struct f_tcm_opts, func_inst);
2208 
2209 	if (opts->tcm_unregister_callback)
2210 		opts->tcm_unregister_callback(f);
2211 }
2212 
2213 static int tcm_set_name(struct usb_function_instance *f, const char *name)
2214 {
2215 	struct f_tcm_opts *opts = container_of(f, struct f_tcm_opts, func_inst);
2216 
2217 	pr_debug("tcm: Activating %s\n", name);
2218 
2219 	mutex_lock(&opts->dep_lock);
2220 	opts->ready = true;
2221 	mutex_unlock(&opts->dep_lock);
2222 
2223 	return 0;
2224 }
2225 
2226 static struct usb_function_instance *tcm_alloc_inst(void)
2227 {
2228 	struct f_tcm_opts *opts;
2229 	int i;
2230 
2231 
2232 	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
2233 	if (!opts)
2234 		return ERR_PTR(-ENOMEM);
2235 
2236 	mutex_lock(&tpg_instances_lock);
2237 	for (i = 0; i < TPG_INSTANCES; ++i)
2238 		if (!tpg_instances[i].func_inst)
2239 			break;
2240 
2241 	if (i == TPG_INSTANCES) {
2242 		mutex_unlock(&tpg_instances_lock);
2243 		kfree(opts);
2244 		return ERR_PTR(-EBUSY);
2245 	}
2246 	tpg_instances[i].func_inst = &opts->func_inst;
2247 	mutex_unlock(&tpg_instances_lock);
2248 
2249 	mutex_init(&opts->dep_lock);
2250 	opts->func_inst.set_inst_name = tcm_set_name;
2251 	opts->func_inst.free_func_inst = tcm_free_inst;
2252 	opts->tcm_register_callback = tcm_register_callback;
2253 	opts->tcm_unregister_callback = tcm_unregister_callback;
2254 
2255 	config_group_init_type_name(&opts->func_inst.group, "",
2256 			&tcm_func_type);
2257 
2258 	return &opts->func_inst;
2259 }
2260 
2261 static void tcm_free(struct usb_function *f)
2262 {
2263 	struct f_uas *tcm = to_f_uas(f);
2264 
2265 	kfree(tcm);
2266 }
2267 
2268 static void tcm_unbind(struct usb_configuration *c, struct usb_function *f)
2269 {
2270 	usb_free_all_descriptors(f);
2271 }
2272 
2273 static struct usb_function *tcm_alloc(struct usb_function_instance *fi)
2274 {
2275 	struct f_uas *fu;
2276 	unsigned i;
2277 
2278 	mutex_lock(&tpg_instances_lock);
2279 	for (i = 0; i < TPG_INSTANCES; ++i)
2280 		if (tpg_instances[i].func_inst == fi)
2281 			break;
2282 	if (i == TPG_INSTANCES) {
2283 		mutex_unlock(&tpg_instances_lock);
2284 		return ERR_PTR(-ENODEV);
2285 	}
2286 
2287 	fu = kzalloc(sizeof(*fu), GFP_KERNEL);
2288 	if (!fu) {
2289 		mutex_unlock(&tpg_instances_lock);
2290 		return ERR_PTR(-ENOMEM);
2291 	}
2292 
2293 	fu->function.name = "Target Function";
2294 	fu->function.bind = tcm_bind;
2295 	fu->function.unbind = tcm_unbind;
2296 	fu->function.set_alt = tcm_set_alt;
2297 	fu->function.get_alt = tcm_get_alt;
2298 	fu->function.setup = tcm_setup;
2299 	fu->function.disable = tcm_disable;
2300 	fu->function.free_func = tcm_free;
2301 	fu->tpg = tpg_instances[i].tpg;
2302 	mutex_unlock(&tpg_instances_lock);
2303 
2304 	return &fu->function;
2305 }
2306 
2307 DECLARE_USB_FUNCTION(tcm, tcm_alloc_inst, tcm_alloc);
2308 
2309 static int tcm_init(void)
2310 {
2311 	int ret;
2312 
2313 	ret = usb_function_register(&tcmusb_func);
2314 	if (ret)
2315 		return ret;
2316 
2317 	ret = target_register_template(&usbg_ops);
2318 	if (ret)
2319 		usb_function_unregister(&tcmusb_func);
2320 
2321 	return ret;
2322 }
2323 module_init(tcm_init);
2324 
2325 static void tcm_exit(void)
2326 {
2327 	target_unregister_template(&usbg_ops);
2328 	usb_function_unregister(&tcmusb_func);
2329 }
2330 module_exit(tcm_exit);
2331 
2332 MODULE_LICENSE("GPL");
2333 MODULE_AUTHOR("Sebastian Andrzej Siewior");
2334