1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2016 Chelsio Communications, Inc.
4  */
5 
6 #include <linux/workqueue.h>
7 #include <linux/kthread.h>
8 #include <linux/sched/signal.h>
9 
10 #include <asm/unaligned.h>
11 #include <net/tcp.h>
12 #include <target/target_core_base.h>
13 #include <target/target_core_fabric.h>
14 #include "cxgbit.h"
15 
16 struct sge_opaque_hdr {
17 	void *dev;
18 	dma_addr_t addr[MAX_SKB_FRAGS + 1];
19 };
20 
21 static const u8 cxgbit_digest_len[] = {0, 4, 4, 8};
22 
23 #define TX_HDR_LEN (sizeof(struct sge_opaque_hdr) + \
24 		    sizeof(struct fw_ofld_tx_data_wr))
25 
26 static struct sk_buff *
27 __cxgbit_alloc_skb(struct cxgbit_sock *csk, u32 len, bool iso)
28 {
29 	struct sk_buff *skb = NULL;
30 	u8 submode = 0;
31 	int errcode;
32 	static const u32 hdr_len = TX_HDR_LEN + ISCSI_HDR_LEN;
33 
34 	if (len) {
35 		skb = alloc_skb_with_frags(hdr_len, len,
36 					   0, &errcode,
37 					   GFP_KERNEL);
38 		if (!skb)
39 			return NULL;
40 
41 		skb_reserve(skb, TX_HDR_LEN);
42 		skb_reset_transport_header(skb);
43 		__skb_put(skb, ISCSI_HDR_LEN);
44 		skb->data_len = len;
45 		skb->len += len;
46 		submode |= (csk->submode & CXGBIT_SUBMODE_DCRC);
47 
48 	} else {
49 		u32 iso_len = iso ? sizeof(struct cpl_tx_data_iso) : 0;
50 
51 		skb = alloc_skb(hdr_len + iso_len, GFP_KERNEL);
52 		if (!skb)
53 			return NULL;
54 
55 		skb_reserve(skb, TX_HDR_LEN + iso_len);
56 		skb_reset_transport_header(skb);
57 		__skb_put(skb, ISCSI_HDR_LEN);
58 	}
59 
60 	submode |= (csk->submode & CXGBIT_SUBMODE_HCRC);
61 	cxgbit_skcb_submode(skb) = submode;
62 	cxgbit_skcb_tx_extralen(skb) = cxgbit_digest_len[submode];
63 	cxgbit_skcb_flags(skb) |= SKCBF_TX_NEED_HDR;
64 	return skb;
65 }
66 
67 static struct sk_buff *cxgbit_alloc_skb(struct cxgbit_sock *csk, u32 len)
68 {
69 	return __cxgbit_alloc_skb(csk, len, false);
70 }
71 
72 /*
73  * cxgbit_is_ofld_imm - check whether a packet can be sent as immediate data
74  * @skb: the packet
75  *
76  * Returns true if a packet can be sent as an offload WR with immediate
77  * data.  We currently use the same limit as for Ethernet packets.
78  */
79 static int cxgbit_is_ofld_imm(const struct sk_buff *skb)
80 {
81 	int length = skb->len;
82 
83 	if (likely(cxgbit_skcb_flags(skb) & SKCBF_TX_NEED_HDR))
84 		length += sizeof(struct fw_ofld_tx_data_wr);
85 
86 	if (likely(cxgbit_skcb_flags(skb) & SKCBF_TX_ISO))
87 		length += sizeof(struct cpl_tx_data_iso);
88 
89 	return length <= MAX_IMM_OFLD_TX_DATA_WR_LEN;
90 }
91 
92 /*
93  * cxgbit_sgl_len - calculates the size of an SGL of the given capacity
94  * @n: the number of SGL entries
95  * Calculates the number of flits needed for a scatter/gather list that
96  * can hold the given number of entries.
97  */
98 static inline unsigned int cxgbit_sgl_len(unsigned int n)
99 {
100 	n--;
101 	return (3 * n) / 2 + (n & 1) + 2;
102 }
103 
104 /*
105  * cxgbit_calc_tx_flits_ofld - calculate # of flits for an offload packet
106  * @skb: the packet
107  *
108  * Returns the number of flits needed for the given offload packet.
109  * These packets are already fully constructed and no additional headers
110  * will be added.
111  */
112 static unsigned int cxgbit_calc_tx_flits_ofld(const struct sk_buff *skb)
113 {
114 	unsigned int flits, cnt;
115 
116 	if (cxgbit_is_ofld_imm(skb))
117 		return DIV_ROUND_UP(skb->len, 8);
118 	flits = skb_transport_offset(skb) / 8;
119 	cnt = skb_shinfo(skb)->nr_frags;
120 	if (skb_tail_pointer(skb) != skb_transport_header(skb))
121 		cnt++;
122 	return flits + cxgbit_sgl_len(cnt);
123 }
124 
125 #define CXGBIT_ISO_FSLICE 0x1
126 #define CXGBIT_ISO_LSLICE 0x2
127 static void
128 cxgbit_cpl_tx_data_iso(struct sk_buff *skb, struct cxgbit_iso_info *iso_info)
129 {
130 	struct cpl_tx_data_iso *cpl;
131 	unsigned int submode = cxgbit_skcb_submode(skb);
132 	unsigned int fslice = !!(iso_info->flags & CXGBIT_ISO_FSLICE);
133 	unsigned int lslice = !!(iso_info->flags & CXGBIT_ISO_LSLICE);
134 
135 	cpl = __skb_push(skb, sizeof(*cpl));
136 
137 	cpl->op_to_scsi = htonl(CPL_TX_DATA_ISO_OP_V(CPL_TX_DATA_ISO) |
138 			CPL_TX_DATA_ISO_FIRST_V(fslice) |
139 			CPL_TX_DATA_ISO_LAST_V(lslice) |
140 			CPL_TX_DATA_ISO_CPLHDRLEN_V(0) |
141 			CPL_TX_DATA_ISO_HDRCRC_V(submode & 1) |
142 			CPL_TX_DATA_ISO_PLDCRC_V(((submode >> 1) & 1)) |
143 			CPL_TX_DATA_ISO_IMMEDIATE_V(0) |
144 			CPL_TX_DATA_ISO_SCSI_V(2));
145 
146 	cpl->ahs_len = 0;
147 	cpl->mpdu = htons(DIV_ROUND_UP(iso_info->mpdu, 4));
148 	cpl->burst_size = htonl(DIV_ROUND_UP(iso_info->burst_len, 4));
149 	cpl->len = htonl(iso_info->len);
150 	cpl->reserved2_seglen_offset = htonl(0);
151 	cpl->datasn_offset = htonl(0);
152 	cpl->buffer_offset = htonl(0);
153 	cpl->reserved3 = 0;
154 
155 	__skb_pull(skb, sizeof(*cpl));
156 }
157 
158 static void
159 cxgbit_tx_data_wr(struct cxgbit_sock *csk, struct sk_buff *skb, u32 dlen,
160 		  u32 len, u32 credits, u32 compl)
161 {
162 	struct fw_ofld_tx_data_wr *req;
163 	const struct cxgb4_lld_info *lldi = &csk->com.cdev->lldi;
164 	u32 submode = cxgbit_skcb_submode(skb);
165 	u32 wr_ulp_mode = 0;
166 	u32 hdr_size = sizeof(*req);
167 	u32 opcode = FW_OFLD_TX_DATA_WR;
168 	u32 immlen = 0;
169 	u32 force = is_t5(lldi->adapter_type) ? TX_FORCE_V(!submode) :
170 		    T6_TX_FORCE_F;
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 = __skb_push(skb, hdr_size);
183 	req->op_to_immdlen = cpu_to_be32(FW_WR_OP_V(opcode) |
184 					FW_WR_COMPL_V(compl) |
185 					FW_WR_IMMDLEN_V(immlen));
186 	req->flowid_len16 = cpu_to_be32(FW_WR_FLOWID_V(csk->tid) |
187 					FW_WR_LEN16_V(credits));
188 	req->plen = htonl(len);
189 	wr_ulp_mode = FW_OFLD_TX_DATA_WR_ULPMODE_V(ULP_MODE_ISCSI) |
190 				FW_OFLD_TX_DATA_WR_ULPSUBMODE_V(submode);
191 
192 	req->tunnel_to_proxy = htonl((wr_ulp_mode) | force |
193 		 FW_OFLD_TX_DATA_WR_SHOVE_V(skb_peek(&csk->txq) ? 0 : 1));
194 }
195 
196 static void cxgbit_arp_failure_skb_discard(void *handle, struct sk_buff *skb)
197 {
198 	kfree_skb(skb);
199 }
200 
201 void cxgbit_push_tx_frames(struct cxgbit_sock *csk)
202 {
203 	struct sk_buff *skb;
204 
205 	while (csk->wr_cred && ((skb = skb_peek(&csk->txq)) != NULL)) {
206 		u32 dlen = skb->len;
207 		u32 len = skb->len;
208 		u32 credits_needed;
209 		u32 compl = 0;
210 		u32 flowclen16 = 0;
211 		u32 iso_cpl_len = 0;
212 
213 		if (cxgbit_skcb_flags(skb) & SKCBF_TX_ISO)
214 			iso_cpl_len = sizeof(struct cpl_tx_data_iso);
215 
216 		if (cxgbit_is_ofld_imm(skb))
217 			credits_needed = DIV_ROUND_UP(dlen + iso_cpl_len, 16);
218 		else
219 			credits_needed = DIV_ROUND_UP((8 *
220 					cxgbit_calc_tx_flits_ofld(skb)) +
221 					iso_cpl_len, 16);
222 
223 		if (likely(cxgbit_skcb_flags(skb) & SKCBF_TX_NEED_HDR))
224 			credits_needed += DIV_ROUND_UP(
225 				sizeof(struct fw_ofld_tx_data_wr), 16);
226 		/*
227 		 * Assumes the initial credits is large enough to support
228 		 * fw_flowc_wr plus largest possible first payload
229 		 */
230 
231 		if (!test_and_set_bit(CSK_TX_DATA_SENT, &csk->com.flags)) {
232 			flowclen16 = cxgbit_send_tx_flowc_wr(csk);
233 			csk->wr_cred -= flowclen16;
234 			csk->wr_una_cred += flowclen16;
235 		}
236 
237 		if (csk->wr_cred < credits_needed) {
238 			pr_debug("csk 0x%p, skb %u/%u, wr %d < %u.\n",
239 				 csk, skb->len, skb->data_len,
240 				 credits_needed, csk->wr_cred);
241 			break;
242 		}
243 		__skb_unlink(skb, &csk->txq);
244 		set_wr_txq(skb, CPL_PRIORITY_DATA, csk->txq_idx);
245 		skb->csum = (__force __wsum)(credits_needed + flowclen16);
246 		csk->wr_cred -= credits_needed;
247 		csk->wr_una_cred += credits_needed;
248 
249 		pr_debug("csk 0x%p, skb %u/%u, wr %d, left %u, unack %u.\n",
250 			 csk, skb->len, skb->data_len, credits_needed,
251 			 csk->wr_cred, csk->wr_una_cred);
252 
253 		if (likely(cxgbit_skcb_flags(skb) & SKCBF_TX_NEED_HDR)) {
254 			len += cxgbit_skcb_tx_extralen(skb);
255 
256 			if ((csk->wr_una_cred >= (csk->wr_max_cred / 2)) ||
257 			    (!before(csk->write_seq,
258 				     csk->snd_una + csk->snd_win))) {
259 				compl = 1;
260 				csk->wr_una_cred = 0;
261 			}
262 
263 			cxgbit_tx_data_wr(csk, skb, dlen, len, credits_needed,
264 					  compl);
265 			csk->snd_nxt += len;
266 
267 		} else if ((cxgbit_skcb_flags(skb) & SKCBF_TX_FLAG_COMPL) ||
268 			   (csk->wr_una_cred >= (csk->wr_max_cred / 2))) {
269 			struct cpl_close_con_req *req =
270 				(struct cpl_close_con_req *)skb->data;
271 			req->wr.wr_hi |= htonl(FW_WR_COMPL_F);
272 			csk->wr_una_cred = 0;
273 		}
274 
275 		cxgbit_sock_enqueue_wr(csk, skb);
276 		t4_set_arp_err_handler(skb, csk,
277 				       cxgbit_arp_failure_skb_discard);
278 
279 		pr_debug("csk 0x%p,%u, skb 0x%p, %u.\n",
280 			 csk, csk->tid, skb, len);
281 
282 		cxgbit_l2t_send(csk->com.cdev, skb, csk->l2t);
283 	}
284 }
285 
286 static void cxgbit_unlock_sock(struct cxgbit_sock *csk)
287 {
288 	struct sk_buff_head backlogq;
289 	struct sk_buff *skb;
290 	void (*fn)(struct cxgbit_sock *, struct sk_buff *);
291 
292 	skb_queue_head_init(&backlogq);
293 
294 	spin_lock_bh(&csk->lock);
295 	while (skb_queue_len(&csk->backlogq)) {
296 		skb_queue_splice_init(&csk->backlogq, &backlogq);
297 		spin_unlock_bh(&csk->lock);
298 
299 		while ((skb = __skb_dequeue(&backlogq))) {
300 			fn = cxgbit_skcb_rx_backlog_fn(skb);
301 			fn(csk, skb);
302 		}
303 
304 		spin_lock_bh(&csk->lock);
305 	}
306 
307 	csk->lock_owner = false;
308 	spin_unlock_bh(&csk->lock);
309 }
310 
311 static int cxgbit_queue_skb(struct cxgbit_sock *csk, struct sk_buff *skb)
312 {
313 	int ret = 0;
314 
315 	spin_lock_bh(&csk->lock);
316 	csk->lock_owner = true;
317 	spin_unlock_bh(&csk->lock);
318 
319 	if (unlikely((csk->com.state != CSK_STATE_ESTABLISHED) ||
320 		     signal_pending(current))) {
321 		__kfree_skb(skb);
322 		__skb_queue_purge(&csk->ppodq);
323 		ret = -1;
324 		goto unlock;
325 	}
326 
327 	csk->write_seq += skb->len +
328 			  cxgbit_skcb_tx_extralen(skb);
329 
330 	skb_queue_splice_tail_init(&csk->ppodq, &csk->txq);
331 	__skb_queue_tail(&csk->txq, skb);
332 	cxgbit_push_tx_frames(csk);
333 
334 unlock:
335 	cxgbit_unlock_sock(csk);
336 	return ret;
337 }
338 
339 static int
340 cxgbit_map_skb(struct iscsi_cmd *cmd, struct sk_buff *skb, u32 data_offset,
341 	       u32 data_length)
342 {
343 	u32 i = 0, nr_frags = MAX_SKB_FRAGS;
344 	u32 padding = ((-data_length) & 3);
345 	struct scatterlist *sg;
346 	struct page *page;
347 	unsigned int page_off;
348 
349 	if (padding)
350 		nr_frags--;
351 
352 	/*
353 	 * We know each entry in t_data_sg contains a page.
354 	 */
355 	sg = &cmd->se_cmd.t_data_sg[data_offset / PAGE_SIZE];
356 	page_off = (data_offset % PAGE_SIZE);
357 
358 	while (data_length && (i < nr_frags)) {
359 		u32 cur_len = min_t(u32, data_length, sg->length - page_off);
360 
361 		page = sg_page(sg);
362 
363 		get_page(page);
364 		skb_fill_page_desc(skb, i, page, sg->offset + page_off,
365 				   cur_len);
366 		skb->data_len += cur_len;
367 		skb->len += cur_len;
368 		skb->truesize += cur_len;
369 
370 		data_length -= cur_len;
371 		page_off = 0;
372 		sg = sg_next(sg);
373 		i++;
374 	}
375 
376 	if (data_length)
377 		return -1;
378 
379 	if (padding) {
380 		page = alloc_page(GFP_KERNEL | __GFP_ZERO);
381 		if (!page)
382 			return -1;
383 		skb_fill_page_desc(skb, i, page, 0, padding);
384 		skb->data_len += padding;
385 		skb->len += padding;
386 		skb->truesize += padding;
387 	}
388 
389 	return 0;
390 }
391 
392 static int
393 cxgbit_tx_datain_iso(struct cxgbit_sock *csk, struct iscsi_cmd *cmd,
394 		     struct iscsi_datain_req *dr)
395 {
396 	struct iscsi_conn *conn = csk->conn;
397 	struct sk_buff *skb;
398 	struct iscsi_datain datain;
399 	struct cxgbit_iso_info iso_info;
400 	u32 data_length = cmd->se_cmd.data_length;
401 	u32 mrdsl = conn->conn_ops->MaxRecvDataSegmentLength;
402 	u32 num_pdu, plen, tx_data = 0;
403 	bool task_sense = !!(cmd->se_cmd.se_cmd_flags &
404 		SCF_TRANSPORT_TASK_SENSE);
405 	bool set_statsn = false;
406 	int ret = -1;
407 
408 	while (data_length) {
409 		num_pdu = (data_length + mrdsl - 1) / mrdsl;
410 		if (num_pdu > csk->max_iso_npdu)
411 			num_pdu = csk->max_iso_npdu;
412 
413 		plen = num_pdu * mrdsl;
414 		if (plen > data_length)
415 			plen = data_length;
416 
417 		skb = __cxgbit_alloc_skb(csk, 0, true);
418 		if (unlikely(!skb))
419 			return -ENOMEM;
420 
421 		memset(skb->data, 0, ISCSI_HDR_LEN);
422 		cxgbit_skcb_flags(skb) |= SKCBF_TX_ISO;
423 		cxgbit_skcb_submode(skb) |= (csk->submode &
424 				CXGBIT_SUBMODE_DCRC);
425 		cxgbit_skcb_tx_extralen(skb) = (num_pdu *
426 				cxgbit_digest_len[cxgbit_skcb_submode(skb)]) +
427 						((num_pdu - 1) * ISCSI_HDR_LEN);
428 
429 		memset(&datain, 0, sizeof(struct iscsi_datain));
430 		memset(&iso_info, 0, sizeof(iso_info));
431 
432 		if (!tx_data)
433 			iso_info.flags |= CXGBIT_ISO_FSLICE;
434 
435 		if (!(data_length - plen)) {
436 			iso_info.flags |= CXGBIT_ISO_LSLICE;
437 			if (!task_sense) {
438 				datain.flags = ISCSI_FLAG_DATA_STATUS;
439 				iscsit_increment_maxcmdsn(cmd, conn->sess);
440 				cmd->stat_sn = conn->stat_sn++;
441 				set_statsn = true;
442 			}
443 		}
444 
445 		iso_info.burst_len = num_pdu * mrdsl;
446 		iso_info.mpdu = mrdsl;
447 		iso_info.len = ISCSI_HDR_LEN + plen;
448 
449 		cxgbit_cpl_tx_data_iso(skb, &iso_info);
450 
451 		datain.offset = tx_data;
452 		datain.data_sn = cmd->data_sn - 1;
453 
454 		iscsit_build_datain_pdu(cmd, conn, &datain,
455 					(struct iscsi_data_rsp *)skb->data,
456 					set_statsn);
457 
458 		ret = cxgbit_map_skb(cmd, skb, tx_data, plen);
459 		if (unlikely(ret)) {
460 			__kfree_skb(skb);
461 			goto out;
462 		}
463 
464 		ret = cxgbit_queue_skb(csk, skb);
465 		if (unlikely(ret))
466 			goto out;
467 
468 		tx_data += plen;
469 		data_length -= plen;
470 
471 		cmd->read_data_done += plen;
472 		cmd->data_sn += num_pdu;
473 	}
474 
475 	dr->dr_complete = DATAIN_COMPLETE_NORMAL;
476 
477 	return 0;
478 
479 out:
480 	return ret;
481 }
482 
483 static int
484 cxgbit_tx_datain(struct cxgbit_sock *csk, struct iscsi_cmd *cmd,
485 		 const struct iscsi_datain *datain)
486 {
487 	struct sk_buff *skb;
488 	int ret = 0;
489 
490 	skb = cxgbit_alloc_skb(csk, 0);
491 	if (unlikely(!skb))
492 		return -ENOMEM;
493 
494 	memcpy(skb->data, cmd->pdu, ISCSI_HDR_LEN);
495 
496 	if (datain->length) {
497 		cxgbit_skcb_submode(skb) |= (csk->submode &
498 				CXGBIT_SUBMODE_DCRC);
499 		cxgbit_skcb_tx_extralen(skb) =
500 				cxgbit_digest_len[cxgbit_skcb_submode(skb)];
501 	}
502 
503 	ret = cxgbit_map_skb(cmd, skb, datain->offset, datain->length);
504 	if (ret < 0) {
505 		__kfree_skb(skb);
506 		return ret;
507 	}
508 
509 	return cxgbit_queue_skb(csk, skb);
510 }
511 
512 static int
513 cxgbit_xmit_datain_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
514 		       struct iscsi_datain_req *dr,
515 		       const struct iscsi_datain *datain)
516 {
517 	struct cxgbit_sock *csk = conn->context;
518 	u32 data_length = cmd->se_cmd.data_length;
519 	u32 padding = ((-data_length) & 3);
520 	u32 mrdsl = conn->conn_ops->MaxRecvDataSegmentLength;
521 
522 	if ((data_length > mrdsl) && (!dr->recovery) &&
523 	    (!padding) && (!datain->offset) && csk->max_iso_npdu) {
524 		atomic_long_add(data_length - datain->length,
525 				&conn->sess->tx_data_octets);
526 		return cxgbit_tx_datain_iso(csk, cmd, dr);
527 	}
528 
529 	return cxgbit_tx_datain(csk, cmd, datain);
530 }
531 
532 static int
533 cxgbit_xmit_nondatain_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
534 			  const void *data_buf, u32 data_buf_len)
535 {
536 	struct cxgbit_sock *csk = conn->context;
537 	struct sk_buff *skb;
538 	u32 padding = ((-data_buf_len) & 3);
539 
540 	skb = cxgbit_alloc_skb(csk, data_buf_len + padding);
541 	if (unlikely(!skb))
542 		return -ENOMEM;
543 
544 	memcpy(skb->data, cmd->pdu, ISCSI_HDR_LEN);
545 
546 	if (data_buf_len) {
547 		u32 pad_bytes = 0;
548 
549 		skb_store_bits(skb, ISCSI_HDR_LEN, data_buf, data_buf_len);
550 
551 		if (padding)
552 			skb_store_bits(skb, ISCSI_HDR_LEN + data_buf_len,
553 				       &pad_bytes, padding);
554 	}
555 
556 	cxgbit_skcb_tx_extralen(skb) = cxgbit_digest_len[
557 				       cxgbit_skcb_submode(skb)];
558 
559 	return cxgbit_queue_skb(csk, skb);
560 }
561 
562 int
563 cxgbit_xmit_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
564 		struct iscsi_datain_req *dr, const void *buf, u32 buf_len)
565 {
566 	if (dr)
567 		return cxgbit_xmit_datain_pdu(conn, cmd, dr, buf);
568 	else
569 		return cxgbit_xmit_nondatain_pdu(conn, cmd, buf, buf_len);
570 }
571 
572 int cxgbit_validate_params(struct iscsi_conn *conn)
573 {
574 	struct cxgbit_sock *csk = conn->context;
575 	struct cxgbit_device *cdev = csk->com.cdev;
576 	struct iscsi_param *param;
577 	u32 max_xmitdsl;
578 
579 	param = iscsi_find_param_from_key(MAXXMITDATASEGMENTLENGTH,
580 					  conn->param_list);
581 	if (!param)
582 		return -1;
583 
584 	if (kstrtou32(param->value, 0, &max_xmitdsl) < 0)
585 		return -1;
586 
587 	if (max_xmitdsl > cdev->mdsl) {
588 		if (iscsi_change_param_sprintf(
589 			conn, "MaxXmitDataSegmentLength=%u", cdev->mdsl))
590 			return -1;
591 	}
592 
593 	return 0;
594 }
595 
596 static int cxgbit_set_digest(struct cxgbit_sock *csk)
597 {
598 	struct iscsi_conn *conn = csk->conn;
599 	struct iscsi_param *param;
600 
601 	param = iscsi_find_param_from_key(HEADERDIGEST, conn->param_list);
602 	if (!param) {
603 		pr_err("param not found key %s\n", HEADERDIGEST);
604 		return -1;
605 	}
606 
607 	if (!strcmp(param->value, CRC32C))
608 		csk->submode |= CXGBIT_SUBMODE_HCRC;
609 
610 	param = iscsi_find_param_from_key(DATADIGEST, conn->param_list);
611 	if (!param) {
612 		csk->submode = 0;
613 		pr_err("param not found key %s\n", DATADIGEST);
614 		return -1;
615 	}
616 
617 	if (!strcmp(param->value, CRC32C))
618 		csk->submode |= CXGBIT_SUBMODE_DCRC;
619 
620 	if (cxgbit_setup_conn_digest(csk)) {
621 		csk->submode = 0;
622 		return -1;
623 	}
624 
625 	return 0;
626 }
627 
628 static int cxgbit_set_iso_npdu(struct cxgbit_sock *csk)
629 {
630 	struct iscsi_conn *conn = csk->conn;
631 	struct iscsi_conn_ops *conn_ops = conn->conn_ops;
632 	struct iscsi_param *param;
633 	u32 mrdsl, mbl;
634 	u32 max_npdu, max_iso_npdu;
635 	u32 max_iso_payload;
636 
637 	if (conn->login->leading_connection) {
638 		param = iscsi_find_param_from_key(MAXBURSTLENGTH,
639 						  conn->param_list);
640 		if (!param) {
641 			pr_err("param not found key %s\n", MAXBURSTLENGTH);
642 			return -1;
643 		}
644 
645 		if (kstrtou32(param->value, 0, &mbl) < 0)
646 			return -1;
647 	} else {
648 		mbl = conn->sess->sess_ops->MaxBurstLength;
649 	}
650 
651 	mrdsl = conn_ops->MaxRecvDataSegmentLength;
652 	max_npdu = mbl / mrdsl;
653 
654 	max_iso_payload = rounddown(CXGBIT_MAX_ISO_PAYLOAD, csk->emss);
655 
656 	max_iso_npdu = max_iso_payload /
657 		       (ISCSI_HDR_LEN + mrdsl +
658 			cxgbit_digest_len[csk->submode]);
659 
660 	csk->max_iso_npdu = min(max_npdu, max_iso_npdu);
661 
662 	if (csk->max_iso_npdu <= 1)
663 		csk->max_iso_npdu = 0;
664 
665 	return 0;
666 }
667 
668 /*
669  * cxgbit_seq_pdu_inorder()
670  * @csk: pointer to cxgbit socket structure
671  *
672  * This function checks whether data sequence and data
673  * pdu are in order.
674  *
675  * Return: returns -1 on error, 0 if data sequence and
676  * data pdu are in order, 1 if data sequence or data pdu
677  * is not in order.
678  */
679 static int cxgbit_seq_pdu_inorder(struct cxgbit_sock *csk)
680 {
681 	struct iscsi_conn *conn = csk->conn;
682 	struct iscsi_param *param;
683 
684 	if (conn->login->leading_connection) {
685 		param = iscsi_find_param_from_key(DATASEQUENCEINORDER,
686 						  conn->param_list);
687 		if (!param) {
688 			pr_err("param not found key %s\n", DATASEQUENCEINORDER);
689 			return -1;
690 		}
691 
692 		if (strcmp(param->value, YES))
693 			return 1;
694 
695 		param = iscsi_find_param_from_key(DATAPDUINORDER,
696 						  conn->param_list);
697 		if (!param) {
698 			pr_err("param not found key %s\n", DATAPDUINORDER);
699 			return -1;
700 		}
701 
702 		if (strcmp(param->value, YES))
703 			return 1;
704 
705 	} else {
706 		if (!conn->sess->sess_ops->DataSequenceInOrder)
707 			return 1;
708 		if (!conn->sess->sess_ops->DataPDUInOrder)
709 			return 1;
710 	}
711 
712 	return 0;
713 }
714 
715 static int cxgbit_set_params(struct iscsi_conn *conn)
716 {
717 	struct cxgbit_sock *csk = conn->context;
718 	struct cxgbit_device *cdev = csk->com.cdev;
719 	struct cxgbi_ppm *ppm = *csk->com.cdev->lldi.iscsi_ppm;
720 	struct iscsi_conn_ops *conn_ops = conn->conn_ops;
721 	struct iscsi_param *param;
722 	u8 erl;
723 
724 	if (conn_ops->MaxRecvDataSegmentLength > cdev->mdsl)
725 		conn_ops->MaxRecvDataSegmentLength = cdev->mdsl;
726 
727 	if (cxgbit_set_digest(csk))
728 		return -1;
729 
730 	if (conn->login->leading_connection) {
731 		param = iscsi_find_param_from_key(ERRORRECOVERYLEVEL,
732 						  conn->param_list);
733 		if (!param) {
734 			pr_err("param not found key %s\n", ERRORRECOVERYLEVEL);
735 			return -1;
736 		}
737 		if (kstrtou8(param->value, 0, &erl) < 0)
738 			return -1;
739 	} else {
740 		erl = conn->sess->sess_ops->ErrorRecoveryLevel;
741 	}
742 
743 	if (!erl) {
744 		int ret;
745 
746 		ret = cxgbit_seq_pdu_inorder(csk);
747 		if (ret < 0) {
748 			return -1;
749 		} else if (ret > 0) {
750 			if (is_t5(cdev->lldi.adapter_type))
751 				goto enable_ddp;
752 			else
753 				return 0;
754 		}
755 
756 		if (test_bit(CDEV_ISO_ENABLE, &cdev->flags)) {
757 			if (cxgbit_set_iso_npdu(csk))
758 				return -1;
759 		}
760 
761 enable_ddp:
762 		if (test_bit(CDEV_DDP_ENABLE, &cdev->flags)) {
763 			if (cxgbit_setup_conn_pgidx(csk,
764 						    ppm->tformat.pgsz_idx_dflt))
765 				return -1;
766 			set_bit(CSK_DDP_ENABLE, &csk->com.flags);
767 		}
768 	}
769 
770 	return 0;
771 }
772 
773 int
774 cxgbit_put_login_tx(struct iscsi_conn *conn, struct iscsi_login *login,
775 		    u32 length)
776 {
777 	struct cxgbit_sock *csk = conn->context;
778 	struct sk_buff *skb;
779 	u32 padding_buf = 0;
780 	u8 padding = ((-length) & 3);
781 
782 	skb = cxgbit_alloc_skb(csk, length + padding);
783 	if (!skb)
784 		return -ENOMEM;
785 	skb_store_bits(skb, 0, login->rsp, ISCSI_HDR_LEN);
786 	skb_store_bits(skb, ISCSI_HDR_LEN, login->rsp_buf, length);
787 
788 	if (padding)
789 		skb_store_bits(skb, ISCSI_HDR_LEN + length,
790 			       &padding_buf, padding);
791 
792 	if (login->login_complete) {
793 		if (cxgbit_set_params(conn)) {
794 			kfree_skb(skb);
795 			return -1;
796 		}
797 
798 		set_bit(CSK_LOGIN_DONE, &csk->com.flags);
799 	}
800 
801 	if (cxgbit_queue_skb(csk, skb))
802 		return -1;
803 
804 	if ((!login->login_complete) && (!login->login_failed))
805 		schedule_delayed_work(&conn->login_work, 0);
806 
807 	return 0;
808 }
809 
810 static void
811 cxgbit_skb_copy_to_sg(struct sk_buff *skb, struct scatterlist *sg,
812 		      unsigned int nents, u32 skip)
813 {
814 	struct skb_seq_state st;
815 	const u8 *buf;
816 	unsigned int consumed = 0, buf_len;
817 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(skb);
818 
819 	skb_prepare_seq_read(skb, pdu_cb->doffset,
820 			     pdu_cb->doffset + pdu_cb->dlen,
821 			     &st);
822 
823 	while (true) {
824 		buf_len = skb_seq_read(consumed, &buf, &st);
825 		if (!buf_len) {
826 			skb_abort_seq_read(&st);
827 			break;
828 		}
829 
830 		consumed += sg_pcopy_from_buffer(sg, nents, (void *)buf,
831 						 buf_len, skip + consumed);
832 	}
833 }
834 
835 static struct iscsi_cmd *cxgbit_allocate_cmd(struct cxgbit_sock *csk)
836 {
837 	struct iscsi_conn *conn = csk->conn;
838 	struct cxgbi_ppm *ppm = cdev2ppm(csk->com.cdev);
839 	struct cxgbit_cmd *ccmd;
840 	struct iscsi_cmd *cmd;
841 
842 	cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
843 	if (!cmd) {
844 		pr_err("Unable to allocate iscsi_cmd + cxgbit_cmd\n");
845 		return NULL;
846 	}
847 
848 	ccmd = iscsit_priv_cmd(cmd);
849 	ccmd->ttinfo.tag = ppm->tformat.no_ddp_mask;
850 	ccmd->setup_ddp = true;
851 
852 	return cmd;
853 }
854 
855 static int
856 cxgbit_handle_immediate_data(struct iscsi_cmd *cmd, struct iscsi_scsi_req *hdr,
857 			     u32 length)
858 {
859 	struct iscsi_conn *conn = cmd->conn;
860 	struct cxgbit_sock *csk = conn->context;
861 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
862 
863 	if (pdu_cb->flags & PDUCBF_RX_DCRC_ERR) {
864 		pr_err("ImmediateData CRC32C DataDigest error\n");
865 		if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
866 			pr_err("Unable to recover from"
867 			       " Immediate Data digest failure while"
868 			       " in ERL=0.\n");
869 			iscsit_reject_cmd(cmd, ISCSI_REASON_DATA_DIGEST_ERROR,
870 					  (unsigned char *)hdr);
871 			return IMMEDIATE_DATA_CANNOT_RECOVER;
872 		}
873 
874 		iscsit_reject_cmd(cmd, ISCSI_REASON_DATA_DIGEST_ERROR,
875 				  (unsigned char *)hdr);
876 		return IMMEDIATE_DATA_ERL1_CRC_FAILURE;
877 	}
878 
879 	if (cmd->se_cmd.se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
880 		struct cxgbit_cmd *ccmd = iscsit_priv_cmd(cmd);
881 		struct skb_shared_info *ssi = skb_shinfo(csk->skb);
882 		skb_frag_t *dfrag = &ssi->frags[pdu_cb->dfrag_idx];
883 
884 		sg_init_table(&ccmd->sg, 1);
885 		sg_set_page(&ccmd->sg, skb_frag_page(dfrag),
886 				skb_frag_size(dfrag), skb_frag_off(dfrag));
887 		get_page(skb_frag_page(dfrag));
888 
889 		cmd->se_cmd.t_data_sg = &ccmd->sg;
890 		cmd->se_cmd.t_data_nents = 1;
891 
892 		ccmd->release = true;
893 	} else {
894 		struct scatterlist *sg = &cmd->se_cmd.t_data_sg[0];
895 		u32 sg_nents = max(1UL, DIV_ROUND_UP(pdu_cb->dlen, PAGE_SIZE));
896 
897 		cxgbit_skb_copy_to_sg(csk->skb, sg, sg_nents, 0);
898 	}
899 
900 	cmd->write_data_done += pdu_cb->dlen;
901 
902 	if (cmd->write_data_done == cmd->se_cmd.data_length) {
903 		spin_lock_bh(&cmd->istate_lock);
904 		cmd->cmd_flags |= ICF_GOT_LAST_DATAOUT;
905 		cmd->i_state = ISTATE_RECEIVED_LAST_DATAOUT;
906 		spin_unlock_bh(&cmd->istate_lock);
907 	}
908 
909 	return IMMEDIATE_DATA_NORMAL_OPERATION;
910 }
911 
912 static int
913 cxgbit_get_immediate_data(struct iscsi_cmd *cmd, struct iscsi_scsi_req *hdr,
914 			  bool dump_payload)
915 {
916 	struct iscsi_conn *conn = cmd->conn;
917 	int cmdsn_ret = 0, immed_ret = IMMEDIATE_DATA_NORMAL_OPERATION;
918 	/*
919 	 * Special case for Unsupported SAM WRITE Opcodes and ImmediateData=Yes.
920 	 */
921 	if (dump_payload)
922 		goto after_immediate_data;
923 
924 	immed_ret = cxgbit_handle_immediate_data(cmd, hdr,
925 						 cmd->first_burst_len);
926 after_immediate_data:
927 	if (immed_ret == IMMEDIATE_DATA_NORMAL_OPERATION) {
928 		/*
929 		 * A PDU/CmdSN carrying Immediate Data passed
930 		 * DataCRC, check against ExpCmdSN/MaxCmdSN if
931 		 * Immediate Bit is not set.
932 		 */
933 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd,
934 						(unsigned char *)hdr,
935 						hdr->cmdsn);
936 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
937 			return -1;
938 
939 		if (cmd->sense_reason || cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
940 			target_put_sess_cmd(&cmd->se_cmd);
941 			return 0;
942 		} else if (cmd->unsolicited_data) {
943 			iscsit_set_unsolicited_dataout(cmd);
944 		}
945 
946 	} else if (immed_ret == IMMEDIATE_DATA_ERL1_CRC_FAILURE) {
947 		/*
948 		 * Immediate Data failed DataCRC and ERL>=1,
949 		 * silently drop this PDU and let the initiator
950 		 * plug the CmdSN gap.
951 		 *
952 		 * FIXME: Send Unsolicited NOPIN with reserved
953 		 * TTT here to help the initiator figure out
954 		 * the missing CmdSN, although they should be
955 		 * intelligent enough to determine the missing
956 		 * CmdSN and issue a retry to plug the sequence.
957 		 */
958 		cmd->i_state = ISTATE_REMOVE;
959 		iscsit_add_cmd_to_immediate_queue(cmd, conn, cmd->i_state);
960 	} else /* immed_ret == IMMEDIATE_DATA_CANNOT_RECOVER */
961 		return -1;
962 
963 	return 0;
964 }
965 
966 static int
967 cxgbit_handle_scsi_cmd(struct cxgbit_sock *csk, struct iscsi_cmd *cmd)
968 {
969 	struct iscsi_conn *conn = csk->conn;
970 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
971 	struct iscsi_scsi_req *hdr = (struct iscsi_scsi_req *)pdu_cb->hdr;
972 	int rc;
973 	bool dump_payload = false;
974 
975 	rc = iscsit_setup_scsi_cmd(conn, cmd, (unsigned char *)hdr);
976 	if (rc < 0)
977 		return rc;
978 
979 	if (pdu_cb->dlen && (pdu_cb->dlen == cmd->se_cmd.data_length) &&
980 	    (pdu_cb->nr_dfrags == 1))
981 		cmd->se_cmd.se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
982 
983 	rc = iscsit_process_scsi_cmd(conn, cmd, hdr);
984 	if (rc < 0)
985 		return 0;
986 	else if (rc > 0)
987 		dump_payload = true;
988 
989 	if (!pdu_cb->dlen)
990 		return 0;
991 
992 	return cxgbit_get_immediate_data(cmd, hdr, dump_payload);
993 }
994 
995 static int cxgbit_handle_iscsi_dataout(struct cxgbit_sock *csk)
996 {
997 	struct scatterlist *sg_start;
998 	struct iscsi_conn *conn = csk->conn;
999 	struct iscsi_cmd *cmd = NULL;
1000 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
1001 	struct iscsi_data *hdr = (struct iscsi_data *)pdu_cb->hdr;
1002 	u32 data_offset = be32_to_cpu(hdr->offset);
1003 	u32 data_len = pdu_cb->dlen;
1004 	int rc, sg_nents, sg_off;
1005 	bool dcrc_err = false;
1006 
1007 	if (pdu_cb->flags & PDUCBF_RX_DDP_CMP) {
1008 		u32 offset = be32_to_cpu(hdr->offset);
1009 		u32 ddp_data_len;
1010 		u32 payload_length = ntoh24(hdr->dlength);
1011 		bool success = false;
1012 
1013 		cmd = iscsit_find_cmd_from_itt_or_dump(conn, hdr->itt, 0);
1014 		if (!cmd)
1015 			return 0;
1016 
1017 		ddp_data_len = offset - cmd->write_data_done;
1018 		atomic_long_add(ddp_data_len, &conn->sess->rx_data_octets);
1019 
1020 		cmd->write_data_done = offset;
1021 		cmd->next_burst_len = ddp_data_len;
1022 		cmd->data_sn = be32_to_cpu(hdr->datasn);
1023 
1024 		rc = __iscsit_check_dataout_hdr(conn, (unsigned char *)hdr,
1025 						cmd, payload_length, &success);
1026 		if (rc < 0)
1027 			return rc;
1028 		else if (!success)
1029 			return 0;
1030 	} else {
1031 		rc = iscsit_check_dataout_hdr(conn, (unsigned char *)hdr, &cmd);
1032 		if (rc < 0)
1033 			return rc;
1034 		else if (!cmd)
1035 			return 0;
1036 	}
1037 
1038 	if (pdu_cb->flags & PDUCBF_RX_DCRC_ERR) {
1039 		pr_err("ITT: 0x%08x, Offset: %u, Length: %u,"
1040 		       " DataSN: 0x%08x\n",
1041 		       hdr->itt, hdr->offset, data_len,
1042 		       hdr->datasn);
1043 
1044 		dcrc_err = true;
1045 		goto check_payload;
1046 	}
1047 
1048 	pr_debug("DataOut data_len: %u, "
1049 		"write_data_done: %u, data_length: %u\n",
1050 		  data_len,  cmd->write_data_done,
1051 		  cmd->se_cmd.data_length);
1052 
1053 	if (!(pdu_cb->flags & PDUCBF_RX_DATA_DDPD)) {
1054 		u32 skip = data_offset % PAGE_SIZE;
1055 
1056 		sg_off = data_offset / PAGE_SIZE;
1057 		sg_start = &cmd->se_cmd.t_data_sg[sg_off];
1058 		sg_nents = max(1UL, DIV_ROUND_UP(skip + data_len, PAGE_SIZE));
1059 
1060 		cxgbit_skb_copy_to_sg(csk->skb, sg_start, sg_nents, skip);
1061 	}
1062 
1063 check_payload:
1064 
1065 	rc = iscsit_check_dataout_payload(cmd, hdr, dcrc_err);
1066 	if (rc < 0)
1067 		return rc;
1068 
1069 	return 0;
1070 }
1071 
1072 static int cxgbit_handle_nop_out(struct cxgbit_sock *csk, struct iscsi_cmd *cmd)
1073 {
1074 	struct iscsi_conn *conn = csk->conn;
1075 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
1076 	struct iscsi_nopout *hdr = (struct iscsi_nopout *)pdu_cb->hdr;
1077 	unsigned char *ping_data = NULL;
1078 	u32 payload_length = pdu_cb->dlen;
1079 	int ret;
1080 
1081 	ret = iscsit_setup_nop_out(conn, cmd, hdr);
1082 	if (ret < 0)
1083 		return 0;
1084 
1085 	if (pdu_cb->flags & PDUCBF_RX_DCRC_ERR) {
1086 		if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
1087 			pr_err("Unable to recover from"
1088 			       " NOPOUT Ping DataCRC failure while in"
1089 			       " ERL=0.\n");
1090 			ret = -1;
1091 			goto out;
1092 		} else {
1093 			/*
1094 			 * drop this PDU and let the
1095 			 * initiator plug the CmdSN gap.
1096 			 */
1097 			pr_info("Dropping NOPOUT"
1098 				" Command CmdSN: 0x%08x due to"
1099 				" DataCRC error.\n", hdr->cmdsn);
1100 			ret = 0;
1101 			goto out;
1102 		}
1103 	}
1104 
1105 	/*
1106 	 * Handle NOP-OUT payload for traditional iSCSI sockets
1107 	 */
1108 	if (payload_length && hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
1109 		ping_data = kzalloc(payload_length + 1, GFP_KERNEL);
1110 		if (!ping_data) {
1111 			pr_err("Unable to allocate memory for"
1112 				" NOPOUT ping data.\n");
1113 			ret = -1;
1114 			goto out;
1115 		}
1116 
1117 		skb_copy_bits(csk->skb, pdu_cb->doffset,
1118 			      ping_data, payload_length);
1119 
1120 		ping_data[payload_length] = '\0';
1121 		/*
1122 		 * Attach ping data to struct iscsi_cmd->buf_ptr.
1123 		 */
1124 		cmd->buf_ptr = ping_data;
1125 		cmd->buf_ptr_size = payload_length;
1126 
1127 		pr_debug("Got %u bytes of NOPOUT ping"
1128 			" data.\n", payload_length);
1129 		pr_debug("Ping Data: \"%s\"\n", ping_data);
1130 	}
1131 
1132 	return iscsit_process_nop_out(conn, cmd, hdr);
1133 out:
1134 	if (cmd)
1135 		iscsit_free_cmd(cmd, false);
1136 	return ret;
1137 }
1138 
1139 static int
1140 cxgbit_handle_text_cmd(struct cxgbit_sock *csk, struct iscsi_cmd *cmd)
1141 {
1142 	struct iscsi_conn *conn = csk->conn;
1143 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
1144 	struct iscsi_text *hdr = (struct iscsi_text *)pdu_cb->hdr;
1145 	u32 payload_length = pdu_cb->dlen;
1146 	int rc;
1147 	unsigned char *text_in = NULL;
1148 
1149 	rc = iscsit_setup_text_cmd(conn, cmd, hdr);
1150 	if (rc < 0)
1151 		return rc;
1152 
1153 	if (pdu_cb->flags & PDUCBF_RX_DCRC_ERR) {
1154 		if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
1155 			pr_err("Unable to recover from"
1156 			       " Text Data digest failure while in"
1157 			       " ERL=0.\n");
1158 			goto reject;
1159 		} else {
1160 			/*
1161 			 * drop this PDU and let the
1162 			 * initiator plug the CmdSN gap.
1163 			 */
1164 			pr_info("Dropping Text"
1165 				" Command CmdSN: 0x%08x due to"
1166 				" DataCRC error.\n", hdr->cmdsn);
1167 			return 0;
1168 		}
1169 	}
1170 
1171 	if (payload_length) {
1172 		text_in = kzalloc(payload_length, GFP_KERNEL);
1173 		if (!text_in) {
1174 			pr_err("Unable to allocate text_in of payload_length: %u\n",
1175 			       payload_length);
1176 			return -ENOMEM;
1177 		}
1178 		skb_copy_bits(csk->skb, pdu_cb->doffset,
1179 			      text_in, payload_length);
1180 
1181 		text_in[payload_length - 1] = '\0';
1182 
1183 		cmd->text_in_ptr = text_in;
1184 	}
1185 
1186 	return iscsit_process_text_cmd(conn, cmd, hdr);
1187 
1188 reject:
1189 	return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
1190 				 pdu_cb->hdr);
1191 }
1192 
1193 static int cxgbit_target_rx_opcode(struct cxgbit_sock *csk)
1194 {
1195 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
1196 	struct iscsi_hdr *hdr = (struct iscsi_hdr *)pdu_cb->hdr;
1197 	struct iscsi_conn *conn = csk->conn;
1198 	struct iscsi_cmd *cmd = NULL;
1199 	u8 opcode = (hdr->opcode & ISCSI_OPCODE_MASK);
1200 	int ret = -EINVAL;
1201 
1202 	switch (opcode) {
1203 	case ISCSI_OP_SCSI_CMD:
1204 		cmd = cxgbit_allocate_cmd(csk);
1205 		if (!cmd)
1206 			goto reject;
1207 
1208 		ret = cxgbit_handle_scsi_cmd(csk, cmd);
1209 		break;
1210 	case ISCSI_OP_SCSI_DATA_OUT:
1211 		ret = cxgbit_handle_iscsi_dataout(csk);
1212 		break;
1213 	case ISCSI_OP_NOOP_OUT:
1214 		if (hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
1215 			cmd = cxgbit_allocate_cmd(csk);
1216 			if (!cmd)
1217 				goto reject;
1218 		}
1219 
1220 		ret = cxgbit_handle_nop_out(csk, cmd);
1221 		break;
1222 	case ISCSI_OP_SCSI_TMFUNC:
1223 		cmd = cxgbit_allocate_cmd(csk);
1224 		if (!cmd)
1225 			goto reject;
1226 
1227 		ret = iscsit_handle_task_mgt_cmd(conn, cmd,
1228 						 (unsigned char *)hdr);
1229 		break;
1230 	case ISCSI_OP_TEXT:
1231 		if (hdr->ttt != cpu_to_be32(0xFFFFFFFF)) {
1232 			cmd = iscsit_find_cmd_from_itt(conn, hdr->itt);
1233 			if (!cmd)
1234 				goto reject;
1235 		} else {
1236 			cmd = cxgbit_allocate_cmd(csk);
1237 			if (!cmd)
1238 				goto reject;
1239 		}
1240 
1241 		ret = cxgbit_handle_text_cmd(csk, cmd);
1242 		break;
1243 	case ISCSI_OP_LOGOUT:
1244 		cmd = cxgbit_allocate_cmd(csk);
1245 		if (!cmd)
1246 			goto reject;
1247 
1248 		ret = iscsit_handle_logout_cmd(conn, cmd, (unsigned char *)hdr);
1249 		if (ret > 0)
1250 			wait_for_completion_timeout(&conn->conn_logout_comp,
1251 						    SECONDS_FOR_LOGOUT_COMP
1252 						    * HZ);
1253 		break;
1254 	case ISCSI_OP_SNACK:
1255 		ret = iscsit_handle_snack(conn, (unsigned char *)hdr);
1256 		break;
1257 	default:
1258 		pr_err("Got unknown iSCSI OpCode: 0x%02x\n", opcode);
1259 		dump_stack();
1260 		break;
1261 	}
1262 
1263 	return ret;
1264 
1265 reject:
1266 	return iscsit_add_reject(conn, ISCSI_REASON_BOOKMARK_NO_RESOURCES,
1267 				 (unsigned char *)hdr);
1268 	return ret;
1269 }
1270 
1271 static int cxgbit_rx_opcode(struct cxgbit_sock *csk)
1272 {
1273 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
1274 	struct iscsi_conn *conn = csk->conn;
1275 	struct iscsi_hdr *hdr = pdu_cb->hdr;
1276 	u8 opcode;
1277 
1278 	if (pdu_cb->flags & PDUCBF_RX_HCRC_ERR) {
1279 		atomic_long_inc(&conn->sess->conn_digest_errors);
1280 		goto transport_err;
1281 	}
1282 
1283 	if (conn->conn_state == TARG_CONN_STATE_IN_LOGOUT)
1284 		goto transport_err;
1285 
1286 	opcode = hdr->opcode & ISCSI_OPCODE_MASK;
1287 
1288 	if (conn->sess->sess_ops->SessionType &&
1289 	    ((!(opcode & ISCSI_OP_TEXT)) ||
1290 	     (!(opcode & ISCSI_OP_LOGOUT)))) {
1291 		pr_err("Received illegal iSCSI Opcode: 0x%02x"
1292 			" while in Discovery Session, rejecting.\n", opcode);
1293 		iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1294 				  (unsigned char *)hdr);
1295 		goto transport_err;
1296 	}
1297 
1298 	if (cxgbit_target_rx_opcode(csk) < 0)
1299 		goto transport_err;
1300 
1301 	return 0;
1302 
1303 transport_err:
1304 	return -1;
1305 }
1306 
1307 static int cxgbit_rx_login_pdu(struct cxgbit_sock *csk)
1308 {
1309 	struct iscsi_conn *conn = csk->conn;
1310 	struct iscsi_login *login = conn->login;
1311 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
1312 	struct iscsi_login_req *login_req;
1313 
1314 	login_req = (struct iscsi_login_req *)login->req;
1315 	memcpy(login_req, pdu_cb->hdr, sizeof(*login_req));
1316 
1317 	pr_debug("Got Login Command, Flags 0x%02x, ITT: 0x%08x,"
1318 		" CmdSN: 0x%08x, ExpStatSN: 0x%08x, CID: %hu, Length: %u\n",
1319 		login_req->flags, login_req->itt, login_req->cmdsn,
1320 		login_req->exp_statsn, login_req->cid, pdu_cb->dlen);
1321 	/*
1322 	 * Setup the initial iscsi_login values from the leading
1323 	 * login request PDU.
1324 	 */
1325 	if (login->first_request) {
1326 		login_req = (struct iscsi_login_req *)login->req;
1327 		login->leading_connection = (!login_req->tsih) ? 1 : 0;
1328 		login->current_stage	= ISCSI_LOGIN_CURRENT_STAGE(
1329 				login_req->flags);
1330 		login->version_min	= login_req->min_version;
1331 		login->version_max	= login_req->max_version;
1332 		memcpy(login->isid, login_req->isid, 6);
1333 		login->cmd_sn		= be32_to_cpu(login_req->cmdsn);
1334 		login->init_task_tag	= login_req->itt;
1335 		login->initial_exp_statsn = be32_to_cpu(login_req->exp_statsn);
1336 		login->cid		= be16_to_cpu(login_req->cid);
1337 		login->tsih		= be16_to_cpu(login_req->tsih);
1338 	}
1339 
1340 	if (iscsi_target_check_login_request(conn, login) < 0)
1341 		return -1;
1342 
1343 	memset(login->req_buf, 0, MAX_KEY_VALUE_PAIRS);
1344 	skb_copy_bits(csk->skb, pdu_cb->doffset, login->req_buf, pdu_cb->dlen);
1345 
1346 	return 0;
1347 }
1348 
1349 static int
1350 cxgbit_process_iscsi_pdu(struct cxgbit_sock *csk, struct sk_buff *skb, int idx)
1351 {
1352 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_skb_lro_pdu_cb(skb, idx);
1353 	int ret;
1354 
1355 	cxgbit_rx_pdu_cb(skb) = pdu_cb;
1356 
1357 	csk->skb = skb;
1358 
1359 	if (!test_bit(CSK_LOGIN_DONE, &csk->com.flags)) {
1360 		ret = cxgbit_rx_login_pdu(csk);
1361 		set_bit(CSK_LOGIN_PDU_DONE, &csk->com.flags);
1362 	} else {
1363 		ret = cxgbit_rx_opcode(csk);
1364 	}
1365 
1366 	return ret;
1367 }
1368 
1369 static void cxgbit_lro_skb_dump(struct sk_buff *skb)
1370 {
1371 	struct skb_shared_info *ssi = skb_shinfo(skb);
1372 	struct cxgbit_lro_cb *lro_cb = cxgbit_skb_lro_cb(skb);
1373 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_skb_lro_pdu_cb(skb, 0);
1374 	u8 i;
1375 
1376 	pr_info("skb 0x%p, head 0x%p, 0x%p, len %u,%u, frags %u.\n",
1377 		skb, skb->head, skb->data, skb->len, skb->data_len,
1378 		ssi->nr_frags);
1379 	pr_info("skb 0x%p, lro_cb, csk 0x%p, pdu %u, %u.\n",
1380 		skb, lro_cb->csk, lro_cb->pdu_idx, lro_cb->pdu_totallen);
1381 
1382 	for (i = 0; i < lro_cb->pdu_idx; i++, pdu_cb++)
1383 		pr_info("skb 0x%p, pdu %d, %u, f 0x%x, seq 0x%x, dcrc 0x%x, "
1384 			"frags %u.\n",
1385 			skb, i, pdu_cb->pdulen, pdu_cb->flags, pdu_cb->seq,
1386 			pdu_cb->ddigest, pdu_cb->frags);
1387 	for (i = 0; i < ssi->nr_frags; i++)
1388 		pr_info("skb 0x%p, frag %d, off %u, sz %u.\n",
1389 			skb, i, skb_frag_off(&ssi->frags[i]),
1390 			skb_frag_size(&ssi->frags[i]));
1391 }
1392 
1393 static void cxgbit_lro_hskb_reset(struct cxgbit_sock *csk)
1394 {
1395 	struct sk_buff *skb = csk->lro_hskb;
1396 	struct skb_shared_info *ssi = skb_shinfo(skb);
1397 	u8 i;
1398 
1399 	memset(skb->data, 0, LRO_SKB_MIN_HEADROOM);
1400 	for (i = 0; i < ssi->nr_frags; i++)
1401 		put_page(skb_frag_page(&ssi->frags[i]));
1402 	ssi->nr_frags = 0;
1403 	skb->data_len = 0;
1404 	skb->truesize -= skb->len;
1405 	skb->len = 0;
1406 }
1407 
1408 static void
1409 cxgbit_lro_skb_merge(struct cxgbit_sock *csk, struct sk_buff *skb, u8 pdu_idx)
1410 {
1411 	struct sk_buff *hskb = csk->lro_hskb;
1412 	struct cxgbit_lro_pdu_cb *hpdu_cb = cxgbit_skb_lro_pdu_cb(hskb, 0);
1413 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_skb_lro_pdu_cb(skb, pdu_idx);
1414 	struct skb_shared_info *hssi = skb_shinfo(hskb);
1415 	struct skb_shared_info *ssi = skb_shinfo(skb);
1416 	unsigned int len = 0;
1417 
1418 	if (pdu_cb->flags & PDUCBF_RX_HDR) {
1419 		u8 hfrag_idx = hssi->nr_frags;
1420 
1421 		hpdu_cb->flags |= pdu_cb->flags;
1422 		hpdu_cb->seq = pdu_cb->seq;
1423 		hpdu_cb->hdr = pdu_cb->hdr;
1424 		hpdu_cb->hlen = pdu_cb->hlen;
1425 
1426 		memcpy(&hssi->frags[hfrag_idx], &ssi->frags[pdu_cb->hfrag_idx],
1427 		       sizeof(skb_frag_t));
1428 
1429 		get_page(skb_frag_page(&hssi->frags[hfrag_idx]));
1430 		hssi->nr_frags++;
1431 		hpdu_cb->frags++;
1432 		hpdu_cb->hfrag_idx = hfrag_idx;
1433 
1434 		len = skb_frag_size(&hssi->frags[hfrag_idx]);
1435 		hskb->len += len;
1436 		hskb->data_len += len;
1437 		hskb->truesize += len;
1438 	}
1439 
1440 	if (pdu_cb->flags & PDUCBF_RX_DATA) {
1441 		u8 dfrag_idx = hssi->nr_frags, i;
1442 
1443 		hpdu_cb->flags |= pdu_cb->flags;
1444 		hpdu_cb->dfrag_idx = dfrag_idx;
1445 
1446 		len = 0;
1447 		for (i = 0; i < pdu_cb->nr_dfrags; dfrag_idx++, i++) {
1448 			memcpy(&hssi->frags[dfrag_idx],
1449 			       &ssi->frags[pdu_cb->dfrag_idx + i],
1450 			       sizeof(skb_frag_t));
1451 
1452 			get_page(skb_frag_page(&hssi->frags[dfrag_idx]));
1453 
1454 			len += skb_frag_size(&hssi->frags[dfrag_idx]);
1455 
1456 			hssi->nr_frags++;
1457 			hpdu_cb->frags++;
1458 		}
1459 
1460 		hpdu_cb->dlen = pdu_cb->dlen;
1461 		hpdu_cb->doffset = hpdu_cb->hlen;
1462 		hpdu_cb->nr_dfrags = pdu_cb->nr_dfrags;
1463 		hskb->len += len;
1464 		hskb->data_len += len;
1465 		hskb->truesize += len;
1466 	}
1467 
1468 	if (pdu_cb->flags & PDUCBF_RX_STATUS) {
1469 		hpdu_cb->flags |= pdu_cb->flags;
1470 
1471 		if (hpdu_cb->flags & PDUCBF_RX_DATA)
1472 			hpdu_cb->flags &= ~PDUCBF_RX_DATA_DDPD;
1473 
1474 		hpdu_cb->ddigest = pdu_cb->ddigest;
1475 		hpdu_cb->pdulen = pdu_cb->pdulen;
1476 	}
1477 }
1478 
1479 static int cxgbit_process_lro_skb(struct cxgbit_sock *csk, struct sk_buff *skb)
1480 {
1481 	struct cxgbit_lro_cb *lro_cb = cxgbit_skb_lro_cb(skb);
1482 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_skb_lro_pdu_cb(skb, 0);
1483 	u8 pdu_idx = 0, last_idx = 0;
1484 	int ret = 0;
1485 
1486 	if (!pdu_cb->complete) {
1487 		cxgbit_lro_skb_merge(csk, skb, 0);
1488 
1489 		if (pdu_cb->flags & PDUCBF_RX_STATUS) {
1490 			struct sk_buff *hskb = csk->lro_hskb;
1491 
1492 			ret = cxgbit_process_iscsi_pdu(csk, hskb, 0);
1493 
1494 			cxgbit_lro_hskb_reset(csk);
1495 
1496 			if (ret < 0)
1497 				goto out;
1498 		}
1499 
1500 		pdu_idx = 1;
1501 	}
1502 
1503 	if (lro_cb->pdu_idx)
1504 		last_idx = lro_cb->pdu_idx - 1;
1505 
1506 	for (; pdu_idx <= last_idx; pdu_idx++) {
1507 		ret = cxgbit_process_iscsi_pdu(csk, skb, pdu_idx);
1508 		if (ret < 0)
1509 			goto out;
1510 	}
1511 
1512 	if ((!lro_cb->complete) && lro_cb->pdu_idx)
1513 		cxgbit_lro_skb_merge(csk, skb, lro_cb->pdu_idx);
1514 
1515 out:
1516 	return ret;
1517 }
1518 
1519 static int cxgbit_rx_lro_skb(struct cxgbit_sock *csk, struct sk_buff *skb)
1520 {
1521 	struct cxgbit_lro_cb *lro_cb = cxgbit_skb_lro_cb(skb);
1522 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_skb_lro_pdu_cb(skb, 0);
1523 	int ret = -1;
1524 
1525 	if ((pdu_cb->flags & PDUCBF_RX_HDR) &&
1526 	    (pdu_cb->seq != csk->rcv_nxt)) {
1527 		pr_info("csk 0x%p, tid 0x%x, seq 0x%x != 0x%x.\n",
1528 			csk, csk->tid, pdu_cb->seq, csk->rcv_nxt);
1529 		cxgbit_lro_skb_dump(skb);
1530 		return ret;
1531 	}
1532 
1533 	csk->rcv_nxt += lro_cb->pdu_totallen;
1534 
1535 	ret = cxgbit_process_lro_skb(csk, skb);
1536 
1537 	csk->rx_credits += lro_cb->pdu_totallen;
1538 
1539 	if (csk->rx_credits >= (csk->rcv_win / 4))
1540 		cxgbit_rx_data_ack(csk);
1541 
1542 	return ret;
1543 }
1544 
1545 static int cxgbit_rx_skb(struct cxgbit_sock *csk, struct sk_buff *skb)
1546 {
1547 	struct cxgb4_lld_info *lldi = &csk->com.cdev->lldi;
1548 	int ret = -1;
1549 
1550 	if (likely(cxgbit_skcb_flags(skb) & SKCBF_RX_LRO)) {
1551 		if (is_t5(lldi->adapter_type))
1552 			ret = cxgbit_rx_lro_skb(csk, skb);
1553 		else
1554 			ret = cxgbit_process_lro_skb(csk, skb);
1555 	}
1556 
1557 	__kfree_skb(skb);
1558 	return ret;
1559 }
1560 
1561 static bool cxgbit_rxq_len(struct cxgbit_sock *csk, struct sk_buff_head *rxq)
1562 {
1563 	spin_lock_bh(&csk->rxq.lock);
1564 	if (skb_queue_len(&csk->rxq)) {
1565 		skb_queue_splice_init(&csk->rxq, rxq);
1566 		spin_unlock_bh(&csk->rxq.lock);
1567 		return true;
1568 	}
1569 	spin_unlock_bh(&csk->rxq.lock);
1570 	return false;
1571 }
1572 
1573 static int cxgbit_wait_rxq(struct cxgbit_sock *csk)
1574 {
1575 	struct sk_buff *skb;
1576 	struct sk_buff_head rxq;
1577 
1578 	skb_queue_head_init(&rxq);
1579 
1580 	wait_event_interruptible(csk->waitq, cxgbit_rxq_len(csk, &rxq));
1581 
1582 	if (signal_pending(current))
1583 		goto out;
1584 
1585 	while ((skb = __skb_dequeue(&rxq))) {
1586 		if (cxgbit_rx_skb(csk, skb))
1587 			goto out;
1588 	}
1589 
1590 	return 0;
1591 out:
1592 	__skb_queue_purge(&rxq);
1593 	return -1;
1594 }
1595 
1596 int cxgbit_get_login_rx(struct iscsi_conn *conn, struct iscsi_login *login)
1597 {
1598 	struct cxgbit_sock *csk = conn->context;
1599 	int ret = -1;
1600 
1601 	while (!test_and_clear_bit(CSK_LOGIN_PDU_DONE, &csk->com.flags)) {
1602 		ret = cxgbit_wait_rxq(csk);
1603 		if (ret) {
1604 			clear_bit(CSK_LOGIN_PDU_DONE, &csk->com.flags);
1605 			break;
1606 		}
1607 	}
1608 
1609 	return ret;
1610 }
1611 
1612 void cxgbit_get_rx_pdu(struct iscsi_conn *conn)
1613 {
1614 	struct cxgbit_sock *csk = conn->context;
1615 
1616 	while (!kthread_should_stop()) {
1617 		iscsit_thread_check_cpumask(conn, current, 0);
1618 		if (cxgbit_wait_rxq(csk))
1619 			return;
1620 	}
1621 }
1622