1 /*
2  * Copyright (c) 2016 Chelsio Communications, Inc.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  */
8 
9 #include <linux/workqueue.h>
10 #include <linux/kthread.h>
11 #include <asm/unaligned.h>
12 #include <net/tcp.h>
13 #include <target/target_core_base.h>
14 #include <target/target_core_fabric.h>
15 #include "cxgbit.h"
16 
17 struct sge_opaque_hdr {
18 	void *dev;
19 	dma_addr_t addr[MAX_SKB_FRAGS + 1];
20 };
21 
22 static const u8 cxgbit_digest_len[] = {0, 4, 4, 8};
23 
24 #define TX_HDR_LEN (sizeof(struct sge_opaque_hdr) + \
25 		    sizeof(struct fw_ofld_tx_data_wr))
26 
27 static struct sk_buff *
28 __cxgbit_alloc_skb(struct cxgbit_sock *csk, u32 len, bool iso)
29 {
30 	struct sk_buff *skb = NULL;
31 	u8 submode = 0;
32 	int errcode;
33 	static const u32 hdr_len = TX_HDR_LEN + ISCSI_HDR_LEN;
34 
35 	if (len) {
36 		skb = alloc_skb_with_frags(hdr_len, len,
37 					   0, &errcode,
38 					   GFP_KERNEL);
39 		if (!skb)
40 			return NULL;
41 
42 		skb_reserve(skb, TX_HDR_LEN);
43 		skb_reset_transport_header(skb);
44 		__skb_put(skb, ISCSI_HDR_LEN);
45 		skb->data_len = len;
46 		skb->len += len;
47 		submode |= (csk->submode & CXGBIT_SUBMODE_DCRC);
48 
49 	} else {
50 		u32 iso_len = iso ? sizeof(struct cpl_tx_data_iso) : 0;
51 
52 		skb = alloc_skb(hdr_len + iso_len, GFP_KERNEL);
53 		if (!skb)
54 			return NULL;
55 
56 		skb_reserve(skb, TX_HDR_LEN + iso_len);
57 		skb_reset_transport_header(skb);
58 		__skb_put(skb, ISCSI_HDR_LEN);
59 	}
60 
61 	submode |= (csk->submode & CXGBIT_SUBMODE_HCRC);
62 	cxgbit_skcb_submode(skb) = submode;
63 	cxgbit_skcb_tx_extralen(skb) = cxgbit_digest_len[submode];
64 	cxgbit_skcb_flags(skb) |= SKCBF_TX_NEED_HDR;
65 	return skb;
66 }
67 
68 static struct sk_buff *cxgbit_alloc_skb(struct cxgbit_sock *csk, u32 len)
69 {
70 	return __cxgbit_alloc_skb(csk, len, false);
71 }
72 
73 /*
74  * cxgbit_is_ofld_imm - check whether a packet can be sent as immediate data
75  * @skb: the packet
76  *
77  * Returns true if a packet can be sent as an offload WR with immediate
78  * data.  We currently use the same limit as for Ethernet packets.
79  */
80 static int cxgbit_is_ofld_imm(const struct sk_buff *skb)
81 {
82 	int length = skb->len;
83 
84 	if (likely(cxgbit_skcb_flags(skb) & SKCBF_TX_NEED_HDR))
85 		length += sizeof(struct fw_ofld_tx_data_wr);
86 
87 	if (likely(cxgbit_skcb_flags(skb) & SKCBF_TX_ISO))
88 		length += sizeof(struct cpl_tx_data_iso);
89 
90 #define MAX_IMM_TX_PKT_LEN	256
91 	return length <= MAX_IMM_TX_PKT_LEN;
92 }
93 
94 /*
95  * cxgbit_sgl_len - calculates the size of an SGL of the given capacity
96  * @n: the number of SGL entries
97  * Calculates the number of flits needed for a scatter/gather list that
98  * can hold the given number of entries.
99  */
100 static inline unsigned int cxgbit_sgl_len(unsigned int n)
101 {
102 	n--;
103 	return (3 * n) / 2 + (n & 1) + 2;
104 }
105 
106 /*
107  * cxgbit_calc_tx_flits_ofld - calculate # of flits for an offload packet
108  * @skb: the packet
109  *
110  * Returns the number of flits needed for the given offload packet.
111  * These packets are already fully constructed and no additional headers
112  * will be added.
113  */
114 static unsigned int cxgbit_calc_tx_flits_ofld(const struct sk_buff *skb)
115 {
116 	unsigned int flits, cnt;
117 
118 	if (cxgbit_is_ofld_imm(skb))
119 		return DIV_ROUND_UP(skb->len, 8);
120 	flits = skb_transport_offset(skb) / 8;
121 	cnt = skb_shinfo(skb)->nr_frags;
122 	if (skb_tail_pointer(skb) != skb_transport_header(skb))
123 		cnt++;
124 	return flits + cxgbit_sgl_len(cnt);
125 }
126 
127 #define CXGBIT_ISO_FSLICE 0x1
128 #define CXGBIT_ISO_LSLICE 0x2
129 static void
130 cxgbit_cpl_tx_data_iso(struct sk_buff *skb, struct cxgbit_iso_info *iso_info)
131 {
132 	struct cpl_tx_data_iso *cpl;
133 	unsigned int submode = cxgbit_skcb_submode(skb);
134 	unsigned int fslice = !!(iso_info->flags & CXGBIT_ISO_FSLICE);
135 	unsigned int lslice = !!(iso_info->flags & CXGBIT_ISO_LSLICE);
136 
137 	cpl = (struct cpl_tx_data_iso *)__skb_push(skb, sizeof(*cpl));
138 
139 	cpl->op_to_scsi = htonl(CPL_TX_DATA_ISO_OP_V(CPL_TX_DATA_ISO) |
140 			CPL_TX_DATA_ISO_FIRST_V(fslice) |
141 			CPL_TX_DATA_ISO_LAST_V(lslice) |
142 			CPL_TX_DATA_ISO_CPLHDRLEN_V(0) |
143 			CPL_TX_DATA_ISO_HDRCRC_V(submode & 1) |
144 			CPL_TX_DATA_ISO_PLDCRC_V(((submode >> 1) & 1)) |
145 			CPL_TX_DATA_ISO_IMMEDIATE_V(0) |
146 			CPL_TX_DATA_ISO_SCSI_V(2));
147 
148 	cpl->ahs_len = 0;
149 	cpl->mpdu = htons(DIV_ROUND_UP(iso_info->mpdu, 4));
150 	cpl->burst_size = htonl(DIV_ROUND_UP(iso_info->burst_len, 4));
151 	cpl->len = htonl(iso_info->len);
152 	cpl->reserved2_seglen_offset = htonl(0);
153 	cpl->datasn_offset = htonl(0);
154 	cpl->buffer_offset = htonl(0);
155 	cpl->reserved3 = 0;
156 
157 	__skb_pull(skb, sizeof(*cpl));
158 }
159 
160 static void
161 cxgbit_tx_data_wr(struct cxgbit_sock *csk, struct sk_buff *skb, u32 dlen,
162 		  u32 len, u32 credits, u32 compl)
163 {
164 	struct fw_ofld_tx_data_wr *req;
165 	u32 submode = cxgbit_skcb_submode(skb);
166 	u32 wr_ulp_mode = 0;
167 	u32 hdr_size = sizeof(*req);
168 	u32 opcode = FW_OFLD_TX_DATA_WR;
169 	u32 immlen = 0;
170 	u32 force = TX_FORCE_V(!submode);
171 
172 	if (cxgbit_skcb_flags(skb) & SKCBF_TX_ISO) {
173 		opcode = FW_ISCSI_TX_DATA_WR;
174 		immlen += sizeof(struct cpl_tx_data_iso);
175 		hdr_size += sizeof(struct cpl_tx_data_iso);
176 		submode |= 8;
177 	}
178 
179 	if (cxgbit_is_ofld_imm(skb))
180 		immlen += dlen;
181 
182 	req = (struct fw_ofld_tx_data_wr *)__skb_push(skb,
183 							hdr_size);
184 	req->op_to_immdlen = cpu_to_be32(FW_WR_OP_V(opcode) |
185 					FW_WR_COMPL_V(compl) |
186 					FW_WR_IMMDLEN_V(immlen));
187 	req->flowid_len16 = cpu_to_be32(FW_WR_FLOWID_V(csk->tid) |
188 					FW_WR_LEN16_V(credits));
189 	req->plen = htonl(len);
190 	wr_ulp_mode = FW_OFLD_TX_DATA_WR_ULPMODE_V(ULP_MODE_ISCSI) |
191 				FW_OFLD_TX_DATA_WR_ULPSUBMODE_V(submode);
192 
193 	req->tunnel_to_proxy = htonl((wr_ulp_mode) | force |
194 		 FW_OFLD_TX_DATA_WR_SHOVE_V(skb_peek(&csk->txq) ? 0 : 1));
195 }
196 
197 static void cxgbit_arp_failure_skb_discard(void *handle, struct sk_buff *skb)
198 {
199 	kfree_skb(skb);
200 }
201 
202 void cxgbit_push_tx_frames(struct cxgbit_sock *csk)
203 {
204 	struct sk_buff *skb;
205 
206 	while (csk->wr_cred && ((skb = skb_peek(&csk->txq)) != NULL)) {
207 		u32 dlen = skb->len;
208 		u32 len = skb->len;
209 		u32 credits_needed;
210 		u32 compl = 0;
211 		u32 flowclen16 = 0;
212 		u32 iso_cpl_len = 0;
213 
214 		if (cxgbit_skcb_flags(skb) & SKCBF_TX_ISO)
215 			iso_cpl_len = sizeof(struct cpl_tx_data_iso);
216 
217 		if (cxgbit_is_ofld_imm(skb))
218 			credits_needed = DIV_ROUND_UP(dlen + iso_cpl_len, 16);
219 		else
220 			credits_needed = DIV_ROUND_UP((8 *
221 					cxgbit_calc_tx_flits_ofld(skb)) +
222 					iso_cpl_len, 16);
223 
224 		if (likely(cxgbit_skcb_flags(skb) & SKCBF_TX_NEED_HDR))
225 			credits_needed += DIV_ROUND_UP(
226 				sizeof(struct fw_ofld_tx_data_wr), 16);
227 		/*
228 		 * Assumes the initial credits is large enough to support
229 		 * fw_flowc_wr plus largest possible first payload
230 		 */
231 
232 		if (!test_and_set_bit(CSK_TX_DATA_SENT, &csk->com.flags)) {
233 			flowclen16 = cxgbit_send_tx_flowc_wr(csk);
234 			csk->wr_cred -= flowclen16;
235 			csk->wr_una_cred += flowclen16;
236 		}
237 
238 		if (csk->wr_cred < credits_needed) {
239 			pr_debug("csk 0x%p, skb %u/%u, wr %d < %u.\n",
240 				 csk, skb->len, skb->data_len,
241 				 credits_needed, csk->wr_cred);
242 			break;
243 		}
244 		__skb_unlink(skb, &csk->txq);
245 		set_wr_txq(skb, CPL_PRIORITY_DATA, csk->txq_idx);
246 		skb->csum = credits_needed + flowclen16;
247 		csk->wr_cred -= credits_needed;
248 		csk->wr_una_cred += credits_needed;
249 
250 		pr_debug("csk 0x%p, skb %u/%u, wr %d, left %u, unack %u.\n",
251 			 csk, skb->len, skb->data_len, credits_needed,
252 			 csk->wr_cred, csk->wr_una_cred);
253 
254 		if (likely(cxgbit_skcb_flags(skb) & SKCBF_TX_NEED_HDR)) {
255 			len += cxgbit_skcb_tx_extralen(skb);
256 
257 			if ((csk->wr_una_cred >= (csk->wr_max_cred / 2)) ||
258 			    (!before(csk->write_seq,
259 				     csk->snd_una + csk->snd_win))) {
260 				compl = 1;
261 				csk->wr_una_cred = 0;
262 			}
263 
264 			cxgbit_tx_data_wr(csk, skb, dlen, len, credits_needed,
265 					  compl);
266 			csk->snd_nxt += len;
267 
268 		} else if ((cxgbit_skcb_flags(skb) & SKCBF_TX_FLAG_COMPL) ||
269 			   (csk->wr_una_cred >= (csk->wr_max_cred / 2))) {
270 			struct cpl_close_con_req *req =
271 				(struct cpl_close_con_req *)skb->data;
272 			req->wr.wr_hi |= htonl(FW_WR_COMPL_F);
273 			csk->wr_una_cred = 0;
274 		}
275 
276 		cxgbit_sock_enqueue_wr(csk, skb);
277 		t4_set_arp_err_handler(skb, csk,
278 				       cxgbit_arp_failure_skb_discard);
279 
280 		pr_debug("csk 0x%p,%u, skb 0x%p, %u.\n",
281 			 csk, csk->tid, skb, len);
282 
283 		cxgbit_l2t_send(csk->com.cdev, skb, csk->l2t);
284 	}
285 }
286 
287 static bool cxgbit_lock_sock(struct cxgbit_sock *csk)
288 {
289 	spin_lock_bh(&csk->lock);
290 
291 	if (before(csk->write_seq, csk->snd_una + csk->snd_win))
292 		csk->lock_owner = true;
293 
294 	spin_unlock_bh(&csk->lock);
295 
296 	return csk->lock_owner;
297 }
298 
299 static void cxgbit_unlock_sock(struct cxgbit_sock *csk)
300 {
301 	struct sk_buff_head backlogq;
302 	struct sk_buff *skb;
303 	void (*fn)(struct cxgbit_sock *, struct sk_buff *);
304 
305 	skb_queue_head_init(&backlogq);
306 
307 	spin_lock_bh(&csk->lock);
308 	while (skb_queue_len(&csk->backlogq)) {
309 		skb_queue_splice_init(&csk->backlogq, &backlogq);
310 		spin_unlock_bh(&csk->lock);
311 
312 		while ((skb = __skb_dequeue(&backlogq))) {
313 			fn = cxgbit_skcb_rx_backlog_fn(skb);
314 			fn(csk, skb);
315 		}
316 
317 		spin_lock_bh(&csk->lock);
318 	}
319 
320 	csk->lock_owner = false;
321 	spin_unlock_bh(&csk->lock);
322 }
323 
324 static int cxgbit_queue_skb(struct cxgbit_sock *csk, struct sk_buff *skb)
325 {
326 	int ret = 0;
327 
328 	wait_event_interruptible(csk->ack_waitq, cxgbit_lock_sock(csk));
329 
330 	if (unlikely((csk->com.state != CSK_STATE_ESTABLISHED) ||
331 		     signal_pending(current))) {
332 		__kfree_skb(skb);
333 		__skb_queue_purge(&csk->ppodq);
334 		ret = -1;
335 		spin_lock_bh(&csk->lock);
336 		if (csk->lock_owner) {
337 			spin_unlock_bh(&csk->lock);
338 			goto unlock;
339 		}
340 		spin_unlock_bh(&csk->lock);
341 		return ret;
342 	}
343 
344 	csk->write_seq += skb->len +
345 			  cxgbit_skcb_tx_extralen(skb);
346 
347 	skb_queue_splice_tail_init(&csk->ppodq, &csk->txq);
348 	__skb_queue_tail(&csk->txq, skb);
349 	cxgbit_push_tx_frames(csk);
350 
351 unlock:
352 	cxgbit_unlock_sock(csk);
353 	return ret;
354 }
355 
356 static int
357 cxgbit_map_skb(struct iscsi_cmd *cmd, struct sk_buff *skb, u32 data_offset,
358 	       u32 data_length)
359 {
360 	u32 i = 0, nr_frags = MAX_SKB_FRAGS;
361 	u32 padding = ((-data_length) & 3);
362 	struct scatterlist *sg;
363 	struct page *page;
364 	unsigned int page_off;
365 
366 	if (padding)
367 		nr_frags--;
368 
369 	/*
370 	 * We know each entry in t_data_sg contains a page.
371 	 */
372 	sg = &cmd->se_cmd.t_data_sg[data_offset / PAGE_SIZE];
373 	page_off = (data_offset % PAGE_SIZE);
374 
375 	while (data_length && (i < nr_frags)) {
376 		u32 cur_len = min_t(u32, data_length, sg->length - page_off);
377 
378 		page = sg_page(sg);
379 
380 		get_page(page);
381 		skb_fill_page_desc(skb, i, page, sg->offset + page_off,
382 				   cur_len);
383 		skb->data_len += cur_len;
384 		skb->len += cur_len;
385 		skb->truesize += cur_len;
386 
387 		data_length -= cur_len;
388 		page_off = 0;
389 		sg = sg_next(sg);
390 		i++;
391 	}
392 
393 	if (data_length)
394 		return -1;
395 
396 	if (padding) {
397 		page = alloc_page(GFP_KERNEL | __GFP_ZERO);
398 		if (!page)
399 			return -1;
400 		skb_fill_page_desc(skb, i, page, 0, padding);
401 		skb->data_len += padding;
402 		skb->len += padding;
403 		skb->truesize += padding;
404 	}
405 
406 	return 0;
407 }
408 
409 static int
410 cxgbit_tx_datain_iso(struct cxgbit_sock *csk, struct iscsi_cmd *cmd,
411 		     struct iscsi_datain_req *dr)
412 {
413 	struct iscsi_conn *conn = csk->conn;
414 	struct sk_buff *skb;
415 	struct iscsi_datain datain;
416 	struct cxgbit_iso_info iso_info;
417 	u32 data_length = cmd->se_cmd.data_length;
418 	u32 mrdsl = conn->conn_ops->MaxRecvDataSegmentLength;
419 	u32 num_pdu, plen, tx_data = 0;
420 	bool task_sense = !!(cmd->se_cmd.se_cmd_flags &
421 		SCF_TRANSPORT_TASK_SENSE);
422 	bool set_statsn = false;
423 	int ret = -1;
424 
425 	while (data_length) {
426 		num_pdu = (data_length + mrdsl - 1) / mrdsl;
427 		if (num_pdu > csk->max_iso_npdu)
428 			num_pdu = csk->max_iso_npdu;
429 
430 		plen = num_pdu * mrdsl;
431 		if (plen > data_length)
432 			plen = data_length;
433 
434 		skb = __cxgbit_alloc_skb(csk, 0, true);
435 		if (unlikely(!skb))
436 			return -ENOMEM;
437 
438 		memset(skb->data, 0, ISCSI_HDR_LEN);
439 		cxgbit_skcb_flags(skb) |= SKCBF_TX_ISO;
440 		cxgbit_skcb_submode(skb) |= (csk->submode &
441 				CXGBIT_SUBMODE_DCRC);
442 		cxgbit_skcb_tx_extralen(skb) = (num_pdu *
443 				cxgbit_digest_len[cxgbit_skcb_submode(skb)]) +
444 						((num_pdu - 1) * ISCSI_HDR_LEN);
445 
446 		memset(&datain, 0, sizeof(struct iscsi_datain));
447 		memset(&iso_info, 0, sizeof(iso_info));
448 
449 		if (!tx_data)
450 			iso_info.flags |= CXGBIT_ISO_FSLICE;
451 
452 		if (!(data_length - plen)) {
453 			iso_info.flags |= CXGBIT_ISO_LSLICE;
454 			if (!task_sense) {
455 				datain.flags = ISCSI_FLAG_DATA_STATUS;
456 				iscsit_increment_maxcmdsn(cmd, conn->sess);
457 				cmd->stat_sn = conn->stat_sn++;
458 				set_statsn = true;
459 			}
460 		}
461 
462 		iso_info.burst_len = num_pdu * mrdsl;
463 		iso_info.mpdu = mrdsl;
464 		iso_info.len = ISCSI_HDR_LEN + plen;
465 
466 		cxgbit_cpl_tx_data_iso(skb, &iso_info);
467 
468 		datain.offset = tx_data;
469 		datain.data_sn = cmd->data_sn - 1;
470 
471 		iscsit_build_datain_pdu(cmd, conn, &datain,
472 					(struct iscsi_data_rsp *)skb->data,
473 					set_statsn);
474 
475 		ret = cxgbit_map_skb(cmd, skb, tx_data, plen);
476 		if (unlikely(ret)) {
477 			__kfree_skb(skb);
478 			goto out;
479 		}
480 
481 		ret = cxgbit_queue_skb(csk, skb);
482 		if (unlikely(ret))
483 			goto out;
484 
485 		tx_data += plen;
486 		data_length -= plen;
487 
488 		cmd->read_data_done += plen;
489 		cmd->data_sn += num_pdu;
490 	}
491 
492 	dr->dr_complete = DATAIN_COMPLETE_NORMAL;
493 
494 	return 0;
495 
496 out:
497 	return ret;
498 }
499 
500 static int
501 cxgbit_tx_datain(struct cxgbit_sock *csk, struct iscsi_cmd *cmd,
502 		 const struct iscsi_datain *datain)
503 {
504 	struct sk_buff *skb;
505 	int ret = 0;
506 
507 	skb = cxgbit_alloc_skb(csk, 0);
508 	if (unlikely(!skb))
509 		return -ENOMEM;
510 
511 	memcpy(skb->data, cmd->pdu, ISCSI_HDR_LEN);
512 
513 	if (datain->length) {
514 		cxgbit_skcb_submode(skb) |= (csk->submode &
515 				CXGBIT_SUBMODE_DCRC);
516 		cxgbit_skcb_tx_extralen(skb) =
517 				cxgbit_digest_len[cxgbit_skcb_submode(skb)];
518 	}
519 
520 	ret = cxgbit_map_skb(cmd, skb, datain->offset, datain->length);
521 	if (ret < 0) {
522 		__kfree_skb(skb);
523 		return ret;
524 	}
525 
526 	return cxgbit_queue_skb(csk, skb);
527 }
528 
529 static int
530 cxgbit_xmit_datain_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
531 		       struct iscsi_datain_req *dr,
532 		       const struct iscsi_datain *datain)
533 {
534 	struct cxgbit_sock *csk = conn->context;
535 	u32 data_length = cmd->se_cmd.data_length;
536 	u32 padding = ((-data_length) & 3);
537 	u32 mrdsl = conn->conn_ops->MaxRecvDataSegmentLength;
538 
539 	if ((data_length > mrdsl) && (!dr->recovery) &&
540 	    (!padding) && (!datain->offset) && csk->max_iso_npdu) {
541 		atomic_long_add(data_length - datain->length,
542 				&conn->sess->tx_data_octets);
543 		return cxgbit_tx_datain_iso(csk, cmd, dr);
544 	}
545 
546 	return cxgbit_tx_datain(csk, cmd, datain);
547 }
548 
549 static int
550 cxgbit_xmit_nondatain_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
551 			  const void *data_buf, u32 data_buf_len)
552 {
553 	struct cxgbit_sock *csk = conn->context;
554 	struct sk_buff *skb;
555 	u32 padding = ((-data_buf_len) & 3);
556 
557 	skb = cxgbit_alloc_skb(csk, data_buf_len + padding);
558 	if (unlikely(!skb))
559 		return -ENOMEM;
560 
561 	memcpy(skb->data, cmd->pdu, ISCSI_HDR_LEN);
562 
563 	if (data_buf_len) {
564 		u32 pad_bytes = 0;
565 
566 		skb_store_bits(skb, ISCSI_HDR_LEN, data_buf, data_buf_len);
567 
568 		if (padding)
569 			skb_store_bits(skb, ISCSI_HDR_LEN + data_buf_len,
570 				       &pad_bytes, padding);
571 	}
572 
573 	cxgbit_skcb_tx_extralen(skb) = cxgbit_digest_len[
574 				       cxgbit_skcb_submode(skb)];
575 
576 	return cxgbit_queue_skb(csk, skb);
577 }
578 
579 int
580 cxgbit_xmit_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
581 		struct iscsi_datain_req *dr, const void *buf, u32 buf_len)
582 {
583 	if (dr)
584 		return cxgbit_xmit_datain_pdu(conn, cmd, dr, buf);
585 	else
586 		return cxgbit_xmit_nondatain_pdu(conn, cmd, buf, buf_len);
587 }
588 
589 int cxgbit_validate_params(struct iscsi_conn *conn)
590 {
591 	struct cxgbit_sock *csk = conn->context;
592 	struct cxgbit_device *cdev = csk->com.cdev;
593 	struct iscsi_param *param;
594 	u32 max_xmitdsl;
595 
596 	param = iscsi_find_param_from_key(MAXXMITDATASEGMENTLENGTH,
597 					  conn->param_list);
598 	if (!param)
599 		return -1;
600 
601 	if (kstrtou32(param->value, 0, &max_xmitdsl) < 0)
602 		return -1;
603 
604 	if (max_xmitdsl > cdev->mdsl) {
605 		if (iscsi_change_param_sprintf(
606 			conn, "MaxXmitDataSegmentLength=%u", cdev->mdsl))
607 			return -1;
608 	}
609 
610 	return 0;
611 }
612 
613 static int cxgbit_set_digest(struct cxgbit_sock *csk)
614 {
615 	struct iscsi_conn *conn = csk->conn;
616 	struct iscsi_param *param;
617 
618 	param = iscsi_find_param_from_key(HEADERDIGEST, conn->param_list);
619 	if (!param) {
620 		pr_err("param not found key %s\n", HEADERDIGEST);
621 		return -1;
622 	}
623 
624 	if (!strcmp(param->value, CRC32C))
625 		csk->submode |= CXGBIT_SUBMODE_HCRC;
626 
627 	param = iscsi_find_param_from_key(DATADIGEST, conn->param_list);
628 	if (!param) {
629 		csk->submode = 0;
630 		pr_err("param not found key %s\n", DATADIGEST);
631 		return -1;
632 	}
633 
634 	if (!strcmp(param->value, CRC32C))
635 		csk->submode |= CXGBIT_SUBMODE_DCRC;
636 
637 	if (cxgbit_setup_conn_digest(csk)) {
638 		csk->submode = 0;
639 		return -1;
640 	}
641 
642 	return 0;
643 }
644 
645 static int cxgbit_set_iso_npdu(struct cxgbit_sock *csk)
646 {
647 	struct iscsi_conn *conn = csk->conn;
648 	struct iscsi_conn_ops *conn_ops = conn->conn_ops;
649 	struct iscsi_param *param;
650 	u32 mrdsl, mbl;
651 	u32 max_npdu, max_iso_npdu;
652 
653 	if (conn->login->leading_connection) {
654 		param = iscsi_find_param_from_key(DATASEQUENCEINORDER,
655 						  conn->param_list);
656 		if (!param) {
657 			pr_err("param not found key %s\n", DATASEQUENCEINORDER);
658 			return -1;
659 		}
660 
661 		if (strcmp(param->value, YES))
662 			return 0;
663 
664 		param = iscsi_find_param_from_key(DATAPDUINORDER,
665 						  conn->param_list);
666 		if (!param) {
667 			pr_err("param not found key %s\n", DATAPDUINORDER);
668 			return -1;
669 		}
670 
671 		if (strcmp(param->value, YES))
672 			return 0;
673 
674 		param = iscsi_find_param_from_key(MAXBURSTLENGTH,
675 						  conn->param_list);
676 		if (!param) {
677 			pr_err("param not found key %s\n", MAXBURSTLENGTH);
678 			return -1;
679 		}
680 
681 		if (kstrtou32(param->value, 0, &mbl) < 0)
682 			return -1;
683 	} else {
684 		if (!conn->sess->sess_ops->DataSequenceInOrder)
685 			return 0;
686 		if (!conn->sess->sess_ops->DataPDUInOrder)
687 			return 0;
688 
689 		mbl = conn->sess->sess_ops->MaxBurstLength;
690 	}
691 
692 	mrdsl = conn_ops->MaxRecvDataSegmentLength;
693 	max_npdu = mbl / mrdsl;
694 
695 	max_iso_npdu = CXGBIT_MAX_ISO_PAYLOAD /
696 			(ISCSI_HDR_LEN + mrdsl +
697 			cxgbit_digest_len[csk->submode]);
698 
699 	csk->max_iso_npdu = min(max_npdu, max_iso_npdu);
700 
701 	if (csk->max_iso_npdu <= 1)
702 		csk->max_iso_npdu = 0;
703 
704 	return 0;
705 }
706 
707 static int cxgbit_set_params(struct iscsi_conn *conn)
708 {
709 	struct cxgbit_sock *csk = conn->context;
710 	struct cxgbit_device *cdev = csk->com.cdev;
711 	struct cxgbi_ppm *ppm = *csk->com.cdev->lldi.iscsi_ppm;
712 	struct iscsi_conn_ops *conn_ops = conn->conn_ops;
713 	struct iscsi_param *param;
714 	u8 erl;
715 
716 	if (conn_ops->MaxRecvDataSegmentLength > cdev->mdsl)
717 		conn_ops->MaxRecvDataSegmentLength = cdev->mdsl;
718 
719 	if (conn->login->leading_connection) {
720 		param = iscsi_find_param_from_key(ERRORRECOVERYLEVEL,
721 						  conn->param_list);
722 		if (!param) {
723 			pr_err("param not found key %s\n", ERRORRECOVERYLEVEL);
724 			return -1;
725 		}
726 		if (kstrtou8(param->value, 0, &erl) < 0)
727 			return -1;
728 	} else {
729 		erl = conn->sess->sess_ops->ErrorRecoveryLevel;
730 	}
731 
732 	if (!erl) {
733 		if (test_bit(CDEV_ISO_ENABLE, &cdev->flags)) {
734 			if (cxgbit_set_iso_npdu(csk))
735 				return -1;
736 		}
737 
738 		if (test_bit(CDEV_DDP_ENABLE, &cdev->flags)) {
739 			if (cxgbit_setup_conn_pgidx(csk,
740 						    ppm->tformat.pgsz_idx_dflt))
741 				return -1;
742 			set_bit(CSK_DDP_ENABLE, &csk->com.flags);
743 		}
744 	}
745 
746 	if (cxgbit_set_digest(csk))
747 		return -1;
748 
749 	return 0;
750 }
751 
752 int
753 cxgbit_put_login_tx(struct iscsi_conn *conn, struct iscsi_login *login,
754 		    u32 length)
755 {
756 	struct cxgbit_sock *csk = conn->context;
757 	struct sk_buff *skb;
758 	u32 padding_buf = 0;
759 	u8 padding = ((-length) & 3);
760 
761 	skb = cxgbit_alloc_skb(csk, length + padding);
762 	if (!skb)
763 		return -ENOMEM;
764 	skb_store_bits(skb, 0, login->rsp, ISCSI_HDR_LEN);
765 	skb_store_bits(skb, ISCSI_HDR_LEN, login->rsp_buf, length);
766 
767 	if (padding)
768 		skb_store_bits(skb, ISCSI_HDR_LEN + length,
769 			       &padding_buf, padding);
770 
771 	if (login->login_complete) {
772 		if (cxgbit_set_params(conn)) {
773 			kfree_skb(skb);
774 			return -1;
775 		}
776 
777 		set_bit(CSK_LOGIN_DONE, &csk->com.flags);
778 	}
779 
780 	if (cxgbit_queue_skb(csk, skb))
781 		return -1;
782 
783 	if ((!login->login_complete) && (!login->login_failed))
784 		schedule_delayed_work(&conn->login_work, 0);
785 
786 	return 0;
787 }
788 
789 static void
790 cxgbit_skb_copy_to_sg(struct sk_buff *skb, struct scatterlist *sg,
791 		      unsigned int nents)
792 {
793 	struct skb_seq_state st;
794 	const u8 *buf;
795 	unsigned int consumed = 0, buf_len;
796 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(skb);
797 
798 	skb_prepare_seq_read(skb, pdu_cb->doffset,
799 			     pdu_cb->doffset + pdu_cb->dlen,
800 			     &st);
801 
802 	while (true) {
803 		buf_len = skb_seq_read(consumed, &buf, &st);
804 		if (!buf_len) {
805 			skb_abort_seq_read(&st);
806 			break;
807 		}
808 
809 		consumed += sg_pcopy_from_buffer(sg, nents, (void *)buf,
810 						 buf_len, consumed);
811 	}
812 }
813 
814 static struct iscsi_cmd *cxgbit_allocate_cmd(struct cxgbit_sock *csk)
815 {
816 	struct iscsi_conn *conn = csk->conn;
817 	struct cxgbi_ppm *ppm = cdev2ppm(csk->com.cdev);
818 	struct cxgbit_cmd *ccmd;
819 	struct iscsi_cmd *cmd;
820 
821 	cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
822 	if (!cmd) {
823 		pr_err("Unable to allocate iscsi_cmd + cxgbit_cmd\n");
824 		return NULL;
825 	}
826 
827 	ccmd = iscsit_priv_cmd(cmd);
828 	ccmd->ttinfo.tag = ppm->tformat.no_ddp_mask;
829 	ccmd->setup_ddp = true;
830 
831 	return cmd;
832 }
833 
834 static int
835 cxgbit_handle_immediate_data(struct iscsi_cmd *cmd, struct iscsi_scsi_req *hdr,
836 			     u32 length)
837 {
838 	struct iscsi_conn *conn = cmd->conn;
839 	struct cxgbit_sock *csk = conn->context;
840 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
841 
842 	if (pdu_cb->flags & PDUCBF_RX_DCRC_ERR) {
843 		pr_err("ImmediateData CRC32C DataDigest error\n");
844 		if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
845 			pr_err("Unable to recover from"
846 			       " Immediate Data digest failure while"
847 			       " in ERL=0.\n");
848 			iscsit_reject_cmd(cmd, ISCSI_REASON_DATA_DIGEST_ERROR,
849 					  (unsigned char *)hdr);
850 			return IMMEDIATE_DATA_CANNOT_RECOVER;
851 		}
852 
853 		iscsit_reject_cmd(cmd, ISCSI_REASON_DATA_DIGEST_ERROR,
854 				  (unsigned char *)hdr);
855 		return IMMEDIATE_DATA_ERL1_CRC_FAILURE;
856 	}
857 
858 	if (cmd->se_cmd.se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
859 		struct cxgbit_cmd *ccmd = iscsit_priv_cmd(cmd);
860 		struct skb_shared_info *ssi = skb_shinfo(csk->skb);
861 		skb_frag_t *dfrag = &ssi->frags[pdu_cb->dfrag_idx];
862 
863 		sg_init_table(&ccmd->sg, 1);
864 		sg_set_page(&ccmd->sg, dfrag->page.p, skb_frag_size(dfrag),
865 			    dfrag->page_offset);
866 		get_page(dfrag->page.p);
867 
868 		cmd->se_cmd.t_data_sg = &ccmd->sg;
869 		cmd->se_cmd.t_data_nents = 1;
870 
871 		ccmd->release = true;
872 	} else {
873 		struct scatterlist *sg = &cmd->se_cmd.t_data_sg[0];
874 		u32 sg_nents = max(1UL, DIV_ROUND_UP(pdu_cb->dlen, PAGE_SIZE));
875 
876 		cxgbit_skb_copy_to_sg(csk->skb, sg, sg_nents);
877 	}
878 
879 	cmd->write_data_done += pdu_cb->dlen;
880 
881 	if (cmd->write_data_done == cmd->se_cmd.data_length) {
882 		spin_lock_bh(&cmd->istate_lock);
883 		cmd->cmd_flags |= ICF_GOT_LAST_DATAOUT;
884 		cmd->i_state = ISTATE_RECEIVED_LAST_DATAOUT;
885 		spin_unlock_bh(&cmd->istate_lock);
886 	}
887 
888 	return IMMEDIATE_DATA_NORMAL_OPERATION;
889 }
890 
891 static int
892 cxgbit_get_immediate_data(struct iscsi_cmd *cmd, struct iscsi_scsi_req *hdr,
893 			  bool dump_payload)
894 {
895 	struct iscsi_conn *conn = cmd->conn;
896 	int cmdsn_ret = 0, immed_ret = IMMEDIATE_DATA_NORMAL_OPERATION;
897 	/*
898 	 * Special case for Unsupported SAM WRITE Opcodes and ImmediateData=Yes.
899 	 */
900 	if (dump_payload)
901 		goto after_immediate_data;
902 
903 	immed_ret = cxgbit_handle_immediate_data(cmd, hdr,
904 						 cmd->first_burst_len);
905 after_immediate_data:
906 	if (immed_ret == IMMEDIATE_DATA_NORMAL_OPERATION) {
907 		/*
908 		 * A PDU/CmdSN carrying Immediate Data passed
909 		 * DataCRC, check against ExpCmdSN/MaxCmdSN if
910 		 * Immediate Bit is not set.
911 		 */
912 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd,
913 						(unsigned char *)hdr,
914 						hdr->cmdsn);
915 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
916 			return -1;
917 
918 		if (cmd->sense_reason || cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
919 			target_put_sess_cmd(&cmd->se_cmd);
920 			return 0;
921 		} else if (cmd->unsolicited_data) {
922 			iscsit_set_unsoliticed_dataout(cmd);
923 		}
924 
925 	} else if (immed_ret == IMMEDIATE_DATA_ERL1_CRC_FAILURE) {
926 		/*
927 		 * Immediate Data failed DataCRC and ERL>=1,
928 		 * silently drop this PDU and let the initiator
929 		 * plug the CmdSN gap.
930 		 *
931 		 * FIXME: Send Unsolicited NOPIN with reserved
932 		 * TTT here to help the initiator figure out
933 		 * the missing CmdSN, although they should be
934 		 * intelligent enough to determine the missing
935 		 * CmdSN and issue a retry to plug the sequence.
936 		 */
937 		cmd->i_state = ISTATE_REMOVE;
938 		iscsit_add_cmd_to_immediate_queue(cmd, conn, cmd->i_state);
939 	} else /* immed_ret == IMMEDIATE_DATA_CANNOT_RECOVER */
940 		return -1;
941 
942 	return 0;
943 }
944 
945 static int
946 cxgbit_handle_scsi_cmd(struct cxgbit_sock *csk, struct iscsi_cmd *cmd)
947 {
948 	struct iscsi_conn *conn = csk->conn;
949 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
950 	struct iscsi_scsi_req *hdr = (struct iscsi_scsi_req *)pdu_cb->hdr;
951 	int rc;
952 	bool dump_payload = false;
953 
954 	rc = iscsit_setup_scsi_cmd(conn, cmd, (unsigned char *)hdr);
955 	if (rc < 0)
956 		return rc;
957 
958 	if (pdu_cb->dlen && (pdu_cb->dlen == cmd->se_cmd.data_length) &&
959 	    (pdu_cb->nr_dfrags == 1))
960 		cmd->se_cmd.se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
961 
962 	rc = iscsit_process_scsi_cmd(conn, cmd, hdr);
963 	if (rc < 0)
964 		return 0;
965 	else if (rc > 0)
966 		dump_payload = true;
967 
968 	if (!pdu_cb->dlen)
969 		return 0;
970 
971 	return cxgbit_get_immediate_data(cmd, hdr, dump_payload);
972 }
973 
974 static int cxgbit_handle_iscsi_dataout(struct cxgbit_sock *csk)
975 {
976 	struct scatterlist *sg_start;
977 	struct iscsi_conn *conn = csk->conn;
978 	struct iscsi_cmd *cmd = NULL;
979 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
980 	struct iscsi_data *hdr = (struct iscsi_data *)pdu_cb->hdr;
981 	u32 data_offset = be32_to_cpu(hdr->offset);
982 	u32 data_len = pdu_cb->dlen;
983 	int rc, sg_nents, sg_off;
984 	bool dcrc_err = false;
985 
986 	rc = iscsit_check_dataout_hdr(conn, (unsigned char *)hdr, &cmd);
987 	if (rc < 0)
988 		return rc;
989 	else if (!cmd)
990 		return 0;
991 
992 	if (pdu_cb->flags & PDUCBF_RX_DCRC_ERR) {
993 		pr_err("ITT: 0x%08x, Offset: %u, Length: %u,"
994 		       " DataSN: 0x%08x\n",
995 		       hdr->itt, hdr->offset, data_len,
996 		       hdr->datasn);
997 
998 		dcrc_err = true;
999 		goto check_payload;
1000 	}
1001 
1002 	pr_debug("DataOut data_len: %u, "
1003 		"write_data_done: %u, data_length: %u\n",
1004 		  data_len,  cmd->write_data_done,
1005 		  cmd->se_cmd.data_length);
1006 
1007 	if (!(pdu_cb->flags & PDUCBF_RX_DATA_DDPD)) {
1008 		sg_off = data_offset / PAGE_SIZE;
1009 		sg_start = &cmd->se_cmd.t_data_sg[sg_off];
1010 		sg_nents = max(1UL, DIV_ROUND_UP(data_len, PAGE_SIZE));
1011 
1012 		cxgbit_skb_copy_to_sg(csk->skb, sg_start, sg_nents);
1013 	}
1014 
1015 check_payload:
1016 
1017 	rc = iscsit_check_dataout_payload(cmd, hdr, dcrc_err);
1018 	if (rc < 0)
1019 		return rc;
1020 
1021 	return 0;
1022 }
1023 
1024 static int cxgbit_handle_nop_out(struct cxgbit_sock *csk, struct iscsi_cmd *cmd)
1025 {
1026 	struct iscsi_conn *conn = csk->conn;
1027 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
1028 	struct iscsi_nopout *hdr = (struct iscsi_nopout *)pdu_cb->hdr;
1029 	unsigned char *ping_data = NULL;
1030 	u32 payload_length = pdu_cb->dlen;
1031 	int ret;
1032 
1033 	ret = iscsit_setup_nop_out(conn, cmd, hdr);
1034 	if (ret < 0)
1035 		return 0;
1036 
1037 	if (pdu_cb->flags & PDUCBF_RX_DCRC_ERR) {
1038 		if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
1039 			pr_err("Unable to recover from"
1040 			       " NOPOUT Ping DataCRC failure while in"
1041 			       " ERL=0.\n");
1042 			ret = -1;
1043 			goto out;
1044 		} else {
1045 			/*
1046 			 * drop this PDU and let the
1047 			 * initiator plug the CmdSN gap.
1048 			 */
1049 			pr_info("Dropping NOPOUT"
1050 				" Command CmdSN: 0x%08x due to"
1051 				" DataCRC error.\n", hdr->cmdsn);
1052 			ret = 0;
1053 			goto out;
1054 		}
1055 	}
1056 
1057 	/*
1058 	 * Handle NOP-OUT payload for traditional iSCSI sockets
1059 	 */
1060 	if (payload_length && hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
1061 		ping_data = kzalloc(payload_length + 1, GFP_KERNEL);
1062 		if (!ping_data) {
1063 			pr_err("Unable to allocate memory for"
1064 				" NOPOUT ping data.\n");
1065 			ret = -1;
1066 			goto out;
1067 		}
1068 
1069 		skb_copy_bits(csk->skb, pdu_cb->doffset,
1070 			      ping_data, payload_length);
1071 
1072 		ping_data[payload_length] = '\0';
1073 		/*
1074 		 * Attach ping data to struct iscsi_cmd->buf_ptr.
1075 		 */
1076 		cmd->buf_ptr = ping_data;
1077 		cmd->buf_ptr_size = payload_length;
1078 
1079 		pr_debug("Got %u bytes of NOPOUT ping"
1080 			" data.\n", payload_length);
1081 		pr_debug("Ping Data: \"%s\"\n", ping_data);
1082 	}
1083 
1084 	return iscsit_process_nop_out(conn, cmd, hdr);
1085 out:
1086 	if (cmd)
1087 		iscsit_free_cmd(cmd, false);
1088 	return ret;
1089 }
1090 
1091 static int
1092 cxgbit_handle_text_cmd(struct cxgbit_sock *csk, struct iscsi_cmd *cmd)
1093 {
1094 	struct iscsi_conn *conn = csk->conn;
1095 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
1096 	struct iscsi_text *hdr = (struct iscsi_text *)pdu_cb->hdr;
1097 	u32 payload_length = pdu_cb->dlen;
1098 	int rc;
1099 	unsigned char *text_in = NULL;
1100 
1101 	rc = iscsit_setup_text_cmd(conn, cmd, hdr);
1102 	if (rc < 0)
1103 		return rc;
1104 
1105 	if (pdu_cb->flags & PDUCBF_RX_DCRC_ERR) {
1106 		if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
1107 			pr_err("Unable to recover from"
1108 			       " Text Data digest failure while in"
1109 			       " ERL=0.\n");
1110 			goto reject;
1111 		} else {
1112 			/*
1113 			 * drop this PDU and let the
1114 			 * initiator plug the CmdSN gap.
1115 			 */
1116 			pr_info("Dropping Text"
1117 				" Command CmdSN: 0x%08x due to"
1118 				" DataCRC error.\n", hdr->cmdsn);
1119 			return 0;
1120 		}
1121 	}
1122 
1123 	if (payload_length) {
1124 		text_in = kzalloc(payload_length, GFP_KERNEL);
1125 		if (!text_in) {
1126 			pr_err("Unable to allocate text_in of payload_length: %u\n",
1127 			       payload_length);
1128 			return -ENOMEM;
1129 		}
1130 		skb_copy_bits(csk->skb, pdu_cb->doffset,
1131 			      text_in, payload_length);
1132 
1133 		text_in[payload_length - 1] = '\0';
1134 
1135 		cmd->text_in_ptr = text_in;
1136 	}
1137 
1138 	return iscsit_process_text_cmd(conn, cmd, hdr);
1139 
1140 reject:
1141 	return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
1142 				 pdu_cb->hdr);
1143 }
1144 
1145 static int cxgbit_target_rx_opcode(struct cxgbit_sock *csk)
1146 {
1147 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
1148 	struct iscsi_hdr *hdr = (struct iscsi_hdr *)pdu_cb->hdr;
1149 	struct iscsi_conn *conn = csk->conn;
1150 	struct iscsi_cmd *cmd = NULL;
1151 	u8 opcode = (hdr->opcode & ISCSI_OPCODE_MASK);
1152 	int ret = -EINVAL;
1153 
1154 	switch (opcode) {
1155 	case ISCSI_OP_SCSI_CMD:
1156 		cmd = cxgbit_allocate_cmd(csk);
1157 		if (!cmd)
1158 			goto reject;
1159 
1160 		ret = cxgbit_handle_scsi_cmd(csk, cmd);
1161 		break;
1162 	case ISCSI_OP_SCSI_DATA_OUT:
1163 		ret = cxgbit_handle_iscsi_dataout(csk);
1164 		break;
1165 	case ISCSI_OP_NOOP_OUT:
1166 		if (hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
1167 			cmd = cxgbit_allocate_cmd(csk);
1168 			if (!cmd)
1169 				goto reject;
1170 		}
1171 
1172 		ret = cxgbit_handle_nop_out(csk, cmd);
1173 		break;
1174 	case ISCSI_OP_SCSI_TMFUNC:
1175 		cmd = cxgbit_allocate_cmd(csk);
1176 		if (!cmd)
1177 			goto reject;
1178 
1179 		ret = iscsit_handle_task_mgt_cmd(conn, cmd,
1180 						 (unsigned char *)hdr);
1181 		break;
1182 	case ISCSI_OP_TEXT:
1183 		if (hdr->ttt != cpu_to_be32(0xFFFFFFFF)) {
1184 			cmd = iscsit_find_cmd_from_itt(conn, hdr->itt);
1185 			if (!cmd)
1186 				goto reject;
1187 		} else {
1188 			cmd = cxgbit_allocate_cmd(csk);
1189 			if (!cmd)
1190 				goto reject;
1191 		}
1192 
1193 		ret = cxgbit_handle_text_cmd(csk, cmd);
1194 		break;
1195 	case ISCSI_OP_LOGOUT:
1196 		cmd = cxgbit_allocate_cmd(csk);
1197 		if (!cmd)
1198 			goto reject;
1199 
1200 		ret = iscsit_handle_logout_cmd(conn, cmd, (unsigned char *)hdr);
1201 		if (ret > 0)
1202 			wait_for_completion_timeout(&conn->conn_logout_comp,
1203 						    SECONDS_FOR_LOGOUT_COMP
1204 						    * HZ);
1205 		break;
1206 	case ISCSI_OP_SNACK:
1207 		ret = iscsit_handle_snack(conn, (unsigned char *)hdr);
1208 		break;
1209 	default:
1210 		pr_err("Got unknown iSCSI OpCode: 0x%02x\n", opcode);
1211 		dump_stack();
1212 		break;
1213 	}
1214 
1215 	return ret;
1216 
1217 reject:
1218 	return iscsit_add_reject(conn, ISCSI_REASON_BOOKMARK_NO_RESOURCES,
1219 				 (unsigned char *)hdr);
1220 	return ret;
1221 }
1222 
1223 static int cxgbit_rx_opcode(struct cxgbit_sock *csk)
1224 {
1225 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
1226 	struct iscsi_conn *conn = csk->conn;
1227 	struct iscsi_hdr *hdr = pdu_cb->hdr;
1228 	u8 opcode;
1229 
1230 	if (pdu_cb->flags & PDUCBF_RX_HCRC_ERR) {
1231 		atomic_long_inc(&conn->sess->conn_digest_errors);
1232 		goto transport_err;
1233 	}
1234 
1235 	if (conn->conn_state == TARG_CONN_STATE_IN_LOGOUT)
1236 		goto transport_err;
1237 
1238 	opcode = hdr->opcode & ISCSI_OPCODE_MASK;
1239 
1240 	if (conn->sess->sess_ops->SessionType &&
1241 	    ((!(opcode & ISCSI_OP_TEXT)) ||
1242 	     (!(opcode & ISCSI_OP_LOGOUT)))) {
1243 		pr_err("Received illegal iSCSI Opcode: 0x%02x"
1244 			" while in Discovery Session, rejecting.\n", opcode);
1245 		iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1246 				  (unsigned char *)hdr);
1247 		goto transport_err;
1248 	}
1249 
1250 	if (cxgbit_target_rx_opcode(csk) < 0)
1251 		goto transport_err;
1252 
1253 	return 0;
1254 
1255 transport_err:
1256 	return -1;
1257 }
1258 
1259 static int cxgbit_rx_login_pdu(struct cxgbit_sock *csk)
1260 {
1261 	struct iscsi_conn *conn = csk->conn;
1262 	struct iscsi_login *login = conn->login;
1263 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
1264 	struct iscsi_login_req *login_req;
1265 
1266 	login_req = (struct iscsi_login_req *)login->req;
1267 	memcpy(login_req, pdu_cb->hdr, sizeof(*login_req));
1268 
1269 	pr_debug("Got Login Command, Flags 0x%02x, ITT: 0x%08x,"
1270 		" CmdSN: 0x%08x, ExpStatSN: 0x%08x, CID: %hu, Length: %u\n",
1271 		login_req->flags, login_req->itt, login_req->cmdsn,
1272 		login_req->exp_statsn, login_req->cid, pdu_cb->dlen);
1273 	/*
1274 	 * Setup the initial iscsi_login values from the leading
1275 	 * login request PDU.
1276 	 */
1277 	if (login->first_request) {
1278 		login_req = (struct iscsi_login_req *)login->req;
1279 		login->leading_connection = (!login_req->tsih) ? 1 : 0;
1280 		login->current_stage	= ISCSI_LOGIN_CURRENT_STAGE(
1281 				login_req->flags);
1282 		login->version_min	= login_req->min_version;
1283 		login->version_max	= login_req->max_version;
1284 		memcpy(login->isid, login_req->isid, 6);
1285 		login->cmd_sn		= be32_to_cpu(login_req->cmdsn);
1286 		login->init_task_tag	= login_req->itt;
1287 		login->initial_exp_statsn = be32_to_cpu(login_req->exp_statsn);
1288 		login->cid		= be16_to_cpu(login_req->cid);
1289 		login->tsih		= be16_to_cpu(login_req->tsih);
1290 	}
1291 
1292 	if (iscsi_target_check_login_request(conn, login) < 0)
1293 		return -1;
1294 
1295 	memset(login->req_buf, 0, MAX_KEY_VALUE_PAIRS);
1296 	skb_copy_bits(csk->skb, pdu_cb->doffset, login->req_buf, pdu_cb->dlen);
1297 
1298 	return 0;
1299 }
1300 
1301 static int
1302 cxgbit_process_iscsi_pdu(struct cxgbit_sock *csk, struct sk_buff *skb, int idx)
1303 {
1304 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_skb_lro_pdu_cb(skb, idx);
1305 	int ret;
1306 
1307 	cxgbit_rx_pdu_cb(skb) = pdu_cb;
1308 
1309 	csk->skb = skb;
1310 
1311 	if (!test_bit(CSK_LOGIN_DONE, &csk->com.flags)) {
1312 		ret = cxgbit_rx_login_pdu(csk);
1313 		set_bit(CSK_LOGIN_PDU_DONE, &csk->com.flags);
1314 	} else {
1315 		ret = cxgbit_rx_opcode(csk);
1316 	}
1317 
1318 	return ret;
1319 }
1320 
1321 static void cxgbit_lro_skb_dump(struct sk_buff *skb)
1322 {
1323 	struct skb_shared_info *ssi = skb_shinfo(skb);
1324 	struct cxgbit_lro_cb *lro_cb = cxgbit_skb_lro_cb(skb);
1325 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_skb_lro_pdu_cb(skb, 0);
1326 	u8 i;
1327 
1328 	pr_info("skb 0x%p, head 0x%p, 0x%p, len %u,%u, frags %u.\n",
1329 		skb, skb->head, skb->data, skb->len, skb->data_len,
1330 		ssi->nr_frags);
1331 	pr_info("skb 0x%p, lro_cb, csk 0x%p, pdu %u, %u.\n",
1332 		skb, lro_cb->csk, lro_cb->pdu_idx, lro_cb->pdu_totallen);
1333 
1334 	for (i = 0; i < lro_cb->pdu_idx; i++, pdu_cb++)
1335 		pr_info("skb 0x%p, pdu %d, %u, f 0x%x, seq 0x%x, dcrc 0x%x, "
1336 			"frags %u.\n",
1337 			skb, i, pdu_cb->pdulen, pdu_cb->flags, pdu_cb->seq,
1338 			pdu_cb->ddigest, pdu_cb->frags);
1339 	for (i = 0; i < ssi->nr_frags; i++)
1340 		pr_info("skb 0x%p, frag %d, off %u, sz %u.\n",
1341 			skb, i, ssi->frags[i].page_offset, ssi->frags[i].size);
1342 }
1343 
1344 static void cxgbit_lro_hskb_reset(struct cxgbit_sock *csk)
1345 {
1346 	struct sk_buff *skb = csk->lro_hskb;
1347 	struct skb_shared_info *ssi = skb_shinfo(skb);
1348 	u8 i;
1349 
1350 	memset(skb->data, 0, LRO_SKB_MIN_HEADROOM);
1351 	for (i = 0; i < ssi->nr_frags; i++)
1352 		put_page(skb_frag_page(&ssi->frags[i]));
1353 	ssi->nr_frags = 0;
1354 }
1355 
1356 static void
1357 cxgbit_lro_skb_merge(struct cxgbit_sock *csk, struct sk_buff *skb, u8 pdu_idx)
1358 {
1359 	struct sk_buff *hskb = csk->lro_hskb;
1360 	struct cxgbit_lro_pdu_cb *hpdu_cb = cxgbit_skb_lro_pdu_cb(hskb, 0);
1361 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_skb_lro_pdu_cb(skb, pdu_idx);
1362 	struct skb_shared_info *hssi = skb_shinfo(hskb);
1363 	struct skb_shared_info *ssi = skb_shinfo(skb);
1364 	unsigned int len = 0;
1365 
1366 	if (pdu_cb->flags & PDUCBF_RX_HDR) {
1367 		hpdu_cb->flags = pdu_cb->flags;
1368 		hpdu_cb->seq = pdu_cb->seq;
1369 		hpdu_cb->hdr = pdu_cb->hdr;
1370 		hpdu_cb->hlen = pdu_cb->hlen;
1371 
1372 		memcpy(&hssi->frags[0], &ssi->frags[pdu_cb->hfrag_idx],
1373 		       sizeof(skb_frag_t));
1374 
1375 		get_page(skb_frag_page(&hssi->frags[0]));
1376 		hssi->nr_frags = 1;
1377 		hpdu_cb->frags = 1;
1378 		hpdu_cb->hfrag_idx = 0;
1379 
1380 		len = hssi->frags[0].size;
1381 		hskb->len = len;
1382 		hskb->data_len = len;
1383 		hskb->truesize = len;
1384 	}
1385 
1386 	if (pdu_cb->flags & PDUCBF_RX_DATA) {
1387 		u8 hfrag_idx = 1, i;
1388 
1389 		hpdu_cb->flags |= pdu_cb->flags;
1390 
1391 		len = 0;
1392 		for (i = 0; i < pdu_cb->nr_dfrags; hfrag_idx++, i++) {
1393 			memcpy(&hssi->frags[hfrag_idx],
1394 			       &ssi->frags[pdu_cb->dfrag_idx + i],
1395 			       sizeof(skb_frag_t));
1396 
1397 			get_page(skb_frag_page(&hssi->frags[hfrag_idx]));
1398 
1399 			len += hssi->frags[hfrag_idx].size;
1400 
1401 			hssi->nr_frags++;
1402 			hpdu_cb->frags++;
1403 		}
1404 
1405 		hpdu_cb->dlen = pdu_cb->dlen;
1406 		hpdu_cb->doffset = hpdu_cb->hlen;
1407 		hpdu_cb->nr_dfrags = pdu_cb->nr_dfrags;
1408 		hpdu_cb->dfrag_idx = 1;
1409 		hskb->len += len;
1410 		hskb->data_len += len;
1411 		hskb->truesize += len;
1412 	}
1413 
1414 	if (pdu_cb->flags & PDUCBF_RX_STATUS) {
1415 		hpdu_cb->flags |= pdu_cb->flags;
1416 
1417 		if (hpdu_cb->flags & PDUCBF_RX_DATA)
1418 			hpdu_cb->flags &= ~PDUCBF_RX_DATA_DDPD;
1419 
1420 		hpdu_cb->ddigest = pdu_cb->ddigest;
1421 		hpdu_cb->pdulen = pdu_cb->pdulen;
1422 	}
1423 }
1424 
1425 static int cxgbit_process_lro_skb(struct cxgbit_sock *csk, struct sk_buff *skb)
1426 {
1427 	struct cxgbit_lro_cb *lro_cb = cxgbit_skb_lro_cb(skb);
1428 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_skb_lro_pdu_cb(skb, 0);
1429 	u8 pdu_idx = 0, last_idx = 0;
1430 	int ret = 0;
1431 
1432 	if (!pdu_cb->complete) {
1433 		cxgbit_lro_skb_merge(csk, skb, 0);
1434 
1435 		if (pdu_cb->flags & PDUCBF_RX_STATUS) {
1436 			struct sk_buff *hskb = csk->lro_hskb;
1437 
1438 			ret = cxgbit_process_iscsi_pdu(csk, hskb, 0);
1439 
1440 			cxgbit_lro_hskb_reset(csk);
1441 
1442 			if (ret < 0)
1443 				goto out;
1444 		}
1445 
1446 		pdu_idx = 1;
1447 	}
1448 
1449 	if (lro_cb->pdu_idx)
1450 		last_idx = lro_cb->pdu_idx - 1;
1451 
1452 	for (; pdu_idx <= last_idx; pdu_idx++) {
1453 		ret = cxgbit_process_iscsi_pdu(csk, skb, pdu_idx);
1454 		if (ret < 0)
1455 			goto out;
1456 	}
1457 
1458 	if ((!lro_cb->complete) && lro_cb->pdu_idx)
1459 		cxgbit_lro_skb_merge(csk, skb, lro_cb->pdu_idx);
1460 
1461 out:
1462 	return ret;
1463 }
1464 
1465 static int cxgbit_rx_lro_skb(struct cxgbit_sock *csk, struct sk_buff *skb)
1466 {
1467 	struct cxgbit_lro_cb *lro_cb = cxgbit_skb_lro_cb(skb);
1468 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_skb_lro_pdu_cb(skb, 0);
1469 	int ret = -1;
1470 
1471 	if ((pdu_cb->flags & PDUCBF_RX_HDR) &&
1472 	    (pdu_cb->seq != csk->rcv_nxt)) {
1473 		pr_info("csk 0x%p, tid 0x%x, seq 0x%x != 0x%x.\n",
1474 			csk, csk->tid, pdu_cb->seq, csk->rcv_nxt);
1475 		cxgbit_lro_skb_dump(skb);
1476 		return ret;
1477 	}
1478 
1479 	csk->rcv_nxt += lro_cb->pdu_totallen;
1480 
1481 	ret = cxgbit_process_lro_skb(csk, skb);
1482 
1483 	csk->rx_credits += lro_cb->pdu_totallen;
1484 
1485 	if (csk->rx_credits >= (csk->rcv_win / 4))
1486 		cxgbit_rx_data_ack(csk);
1487 
1488 	return ret;
1489 }
1490 
1491 static int cxgbit_rx_skb(struct cxgbit_sock *csk, struct sk_buff *skb)
1492 {
1493 	int ret = -1;
1494 
1495 	if (likely(cxgbit_skcb_flags(skb) & SKCBF_RX_LRO))
1496 		ret = cxgbit_rx_lro_skb(csk, skb);
1497 
1498 	__kfree_skb(skb);
1499 	return ret;
1500 }
1501 
1502 static bool cxgbit_rxq_len(struct cxgbit_sock *csk, struct sk_buff_head *rxq)
1503 {
1504 	spin_lock_bh(&csk->rxq.lock);
1505 	if (skb_queue_len(&csk->rxq)) {
1506 		skb_queue_splice_init(&csk->rxq, rxq);
1507 		spin_unlock_bh(&csk->rxq.lock);
1508 		return true;
1509 	}
1510 	spin_unlock_bh(&csk->rxq.lock);
1511 	return false;
1512 }
1513 
1514 static int cxgbit_wait_rxq(struct cxgbit_sock *csk)
1515 {
1516 	struct sk_buff *skb;
1517 	struct sk_buff_head rxq;
1518 
1519 	skb_queue_head_init(&rxq);
1520 
1521 	wait_event_interruptible(csk->waitq, cxgbit_rxq_len(csk, &rxq));
1522 
1523 	if (signal_pending(current))
1524 		goto out;
1525 
1526 	while ((skb = __skb_dequeue(&rxq))) {
1527 		if (cxgbit_rx_skb(csk, skb))
1528 			goto out;
1529 	}
1530 
1531 	return 0;
1532 out:
1533 	__skb_queue_purge(&rxq);
1534 	return -1;
1535 }
1536 
1537 int cxgbit_get_login_rx(struct iscsi_conn *conn, struct iscsi_login *login)
1538 {
1539 	struct cxgbit_sock *csk = conn->context;
1540 	int ret = -1;
1541 
1542 	while (!test_and_clear_bit(CSK_LOGIN_PDU_DONE, &csk->com.flags)) {
1543 		ret = cxgbit_wait_rxq(csk);
1544 		if (ret) {
1545 			clear_bit(CSK_LOGIN_PDU_DONE, &csk->com.flags);
1546 			break;
1547 		}
1548 	}
1549 
1550 	return ret;
1551 }
1552 
1553 void cxgbit_get_rx_pdu(struct iscsi_conn *conn)
1554 {
1555 	struct cxgbit_sock *csk = conn->context;
1556 
1557 	while (!kthread_should_stop()) {
1558 		iscsit_thread_check_cpumask(conn, current, 0);
1559 		if (cxgbit_wait_rxq(csk))
1560 			return;
1561 	}
1562 }
1563