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 <linux/sched/signal.h>
12 
13 #include <asm/unaligned.h>
14 #include <net/tcp.h>
15 #include <target/target_core_base.h>
16 #include <target/target_core_fabric.h>
17 #include "cxgbit.h"
18 
19 struct sge_opaque_hdr {
20 	void *dev;
21 	dma_addr_t addr[MAX_SKB_FRAGS + 1];
22 };
23 
24 static const u8 cxgbit_digest_len[] = {0, 4, 4, 8};
25 
26 #define TX_HDR_LEN (sizeof(struct sge_opaque_hdr) + \
27 		    sizeof(struct fw_ofld_tx_data_wr))
28 
29 static struct sk_buff *
30 __cxgbit_alloc_skb(struct cxgbit_sock *csk, u32 len, bool iso)
31 {
32 	struct sk_buff *skb = NULL;
33 	u8 submode = 0;
34 	int errcode;
35 	static const u32 hdr_len = TX_HDR_LEN + ISCSI_HDR_LEN;
36 
37 	if (len) {
38 		skb = alloc_skb_with_frags(hdr_len, len,
39 					   0, &errcode,
40 					   GFP_KERNEL);
41 		if (!skb)
42 			return NULL;
43 
44 		skb_reserve(skb, TX_HDR_LEN);
45 		skb_reset_transport_header(skb);
46 		__skb_put(skb, ISCSI_HDR_LEN);
47 		skb->data_len = len;
48 		skb->len += len;
49 		submode |= (csk->submode & CXGBIT_SUBMODE_DCRC);
50 
51 	} else {
52 		u32 iso_len = iso ? sizeof(struct cpl_tx_data_iso) : 0;
53 
54 		skb = alloc_skb(hdr_len + iso_len, GFP_KERNEL);
55 		if (!skb)
56 			return NULL;
57 
58 		skb_reserve(skb, TX_HDR_LEN + iso_len);
59 		skb_reset_transport_header(skb);
60 		__skb_put(skb, ISCSI_HDR_LEN);
61 	}
62 
63 	submode |= (csk->submode & CXGBIT_SUBMODE_HCRC);
64 	cxgbit_skcb_submode(skb) = submode;
65 	cxgbit_skcb_tx_extralen(skb) = cxgbit_digest_len[submode];
66 	cxgbit_skcb_flags(skb) |= SKCBF_TX_NEED_HDR;
67 	return skb;
68 }
69 
70 static struct sk_buff *cxgbit_alloc_skb(struct cxgbit_sock *csk, u32 len)
71 {
72 	return __cxgbit_alloc_skb(csk, len, false);
73 }
74 
75 /*
76  * cxgbit_is_ofld_imm - check whether a packet can be sent as immediate data
77  * @skb: the packet
78  *
79  * Returns true if a packet can be sent as an offload WR with immediate
80  * data.  We currently use the same limit as for Ethernet packets.
81  */
82 static int cxgbit_is_ofld_imm(const struct sk_buff *skb)
83 {
84 	int length = skb->len;
85 
86 	if (likely(cxgbit_skcb_flags(skb) & SKCBF_TX_NEED_HDR))
87 		length += sizeof(struct fw_ofld_tx_data_wr);
88 
89 	if (likely(cxgbit_skcb_flags(skb) & SKCBF_TX_ISO))
90 		length += sizeof(struct cpl_tx_data_iso);
91 
92 #define MAX_IMM_TX_PKT_LEN	256
93 	return length <= MAX_IMM_TX_PKT_LEN;
94 }
95 
96 /*
97  * cxgbit_sgl_len - calculates the size of an SGL of the given capacity
98  * @n: the number of SGL entries
99  * Calculates the number of flits needed for a scatter/gather list that
100  * can hold the given number of entries.
101  */
102 static inline unsigned int cxgbit_sgl_len(unsigned int n)
103 {
104 	n--;
105 	return (3 * n) / 2 + (n & 1) + 2;
106 }
107 
108 /*
109  * cxgbit_calc_tx_flits_ofld - calculate # of flits for an offload packet
110  * @skb: the packet
111  *
112  * Returns the number of flits needed for the given offload packet.
113  * These packets are already fully constructed and no additional headers
114  * will be added.
115  */
116 static unsigned int cxgbit_calc_tx_flits_ofld(const struct sk_buff *skb)
117 {
118 	unsigned int flits, cnt;
119 
120 	if (cxgbit_is_ofld_imm(skb))
121 		return DIV_ROUND_UP(skb->len, 8);
122 	flits = skb_transport_offset(skb) / 8;
123 	cnt = skb_shinfo(skb)->nr_frags;
124 	if (skb_tail_pointer(skb) != skb_transport_header(skb))
125 		cnt++;
126 	return flits + cxgbit_sgl_len(cnt);
127 }
128 
129 #define CXGBIT_ISO_FSLICE 0x1
130 #define CXGBIT_ISO_LSLICE 0x2
131 static void
132 cxgbit_cpl_tx_data_iso(struct sk_buff *skb, struct cxgbit_iso_info *iso_info)
133 {
134 	struct cpl_tx_data_iso *cpl;
135 	unsigned int submode = cxgbit_skcb_submode(skb);
136 	unsigned int fslice = !!(iso_info->flags & CXGBIT_ISO_FSLICE);
137 	unsigned int lslice = !!(iso_info->flags & CXGBIT_ISO_LSLICE);
138 
139 	cpl = __skb_push(skb, sizeof(*cpl));
140 
141 	cpl->op_to_scsi = htonl(CPL_TX_DATA_ISO_OP_V(CPL_TX_DATA_ISO) |
142 			CPL_TX_DATA_ISO_FIRST_V(fslice) |
143 			CPL_TX_DATA_ISO_LAST_V(lslice) |
144 			CPL_TX_DATA_ISO_CPLHDRLEN_V(0) |
145 			CPL_TX_DATA_ISO_HDRCRC_V(submode & 1) |
146 			CPL_TX_DATA_ISO_PLDCRC_V(((submode >> 1) & 1)) |
147 			CPL_TX_DATA_ISO_IMMEDIATE_V(0) |
148 			CPL_TX_DATA_ISO_SCSI_V(2));
149 
150 	cpl->ahs_len = 0;
151 	cpl->mpdu = htons(DIV_ROUND_UP(iso_info->mpdu, 4));
152 	cpl->burst_size = htonl(DIV_ROUND_UP(iso_info->burst_len, 4));
153 	cpl->len = htonl(iso_info->len);
154 	cpl->reserved2_seglen_offset = htonl(0);
155 	cpl->datasn_offset = htonl(0);
156 	cpl->buffer_offset = htonl(0);
157 	cpl->reserved3 = 0;
158 
159 	__skb_pull(skb, sizeof(*cpl));
160 }
161 
162 static void
163 cxgbit_tx_data_wr(struct cxgbit_sock *csk, struct sk_buff *skb, u32 dlen,
164 		  u32 len, u32 credits, u32 compl)
165 {
166 	struct fw_ofld_tx_data_wr *req;
167 	const struct cxgb4_lld_info *lldi = &csk->com.cdev->lldi;
168 	u32 submode = cxgbit_skcb_submode(skb);
169 	u32 wr_ulp_mode = 0;
170 	u32 hdr_size = sizeof(*req);
171 	u32 opcode = FW_OFLD_TX_DATA_WR;
172 	u32 immlen = 0;
173 	u32 force = is_t5(lldi->adapter_type) ? TX_FORCE_V(!submode) :
174 		    T6_TX_FORCE_F;
175 
176 	if (cxgbit_skcb_flags(skb) & SKCBF_TX_ISO) {
177 		opcode = FW_ISCSI_TX_DATA_WR;
178 		immlen += sizeof(struct cpl_tx_data_iso);
179 		hdr_size += sizeof(struct cpl_tx_data_iso);
180 		submode |= 8;
181 	}
182 
183 	if (cxgbit_is_ofld_imm(skb))
184 		immlen += dlen;
185 
186 	req = __skb_push(skb, hdr_size);
187 	req->op_to_immdlen = cpu_to_be32(FW_WR_OP_V(opcode) |
188 					FW_WR_COMPL_V(compl) |
189 					FW_WR_IMMDLEN_V(immlen));
190 	req->flowid_len16 = cpu_to_be32(FW_WR_FLOWID_V(csk->tid) |
191 					FW_WR_LEN16_V(credits));
192 	req->plen = htonl(len);
193 	wr_ulp_mode = FW_OFLD_TX_DATA_WR_ULPMODE_V(ULP_MODE_ISCSI) |
194 				FW_OFLD_TX_DATA_WR_ULPSUBMODE_V(submode);
195 
196 	req->tunnel_to_proxy = htonl((wr_ulp_mode) | force |
197 		 FW_OFLD_TX_DATA_WR_SHOVE_V(skb_peek(&csk->txq) ? 0 : 1));
198 }
199 
200 static void cxgbit_arp_failure_skb_discard(void *handle, struct sk_buff *skb)
201 {
202 	kfree_skb(skb);
203 }
204 
205 void cxgbit_push_tx_frames(struct cxgbit_sock *csk)
206 {
207 	struct sk_buff *skb;
208 
209 	while (csk->wr_cred && ((skb = skb_peek(&csk->txq)) != NULL)) {
210 		u32 dlen = skb->len;
211 		u32 len = skb->len;
212 		u32 credits_needed;
213 		u32 compl = 0;
214 		u32 flowclen16 = 0;
215 		u32 iso_cpl_len = 0;
216 
217 		if (cxgbit_skcb_flags(skb) & SKCBF_TX_ISO)
218 			iso_cpl_len = sizeof(struct cpl_tx_data_iso);
219 
220 		if (cxgbit_is_ofld_imm(skb))
221 			credits_needed = DIV_ROUND_UP(dlen + iso_cpl_len, 16);
222 		else
223 			credits_needed = DIV_ROUND_UP((8 *
224 					cxgbit_calc_tx_flits_ofld(skb)) +
225 					iso_cpl_len, 16);
226 
227 		if (likely(cxgbit_skcb_flags(skb) & SKCBF_TX_NEED_HDR))
228 			credits_needed += DIV_ROUND_UP(
229 				sizeof(struct fw_ofld_tx_data_wr), 16);
230 		/*
231 		 * Assumes the initial credits is large enough to support
232 		 * fw_flowc_wr plus largest possible first payload
233 		 */
234 
235 		if (!test_and_set_bit(CSK_TX_DATA_SENT, &csk->com.flags)) {
236 			flowclen16 = cxgbit_send_tx_flowc_wr(csk);
237 			csk->wr_cred -= flowclen16;
238 			csk->wr_una_cred += flowclen16;
239 		}
240 
241 		if (csk->wr_cred < credits_needed) {
242 			pr_debug("csk 0x%p, skb %u/%u, wr %d < %u.\n",
243 				 csk, skb->len, skb->data_len,
244 				 credits_needed, csk->wr_cred);
245 			break;
246 		}
247 		__skb_unlink(skb, &csk->txq);
248 		set_wr_txq(skb, CPL_PRIORITY_DATA, csk->txq_idx);
249 		skb->csum = (__force __wsum)(credits_needed + flowclen16);
250 		csk->wr_cred -= credits_needed;
251 		csk->wr_una_cred += credits_needed;
252 
253 		pr_debug("csk 0x%p, skb %u/%u, wr %d, left %u, unack %u.\n",
254 			 csk, skb->len, skb->data_len, credits_needed,
255 			 csk->wr_cred, csk->wr_una_cred);
256 
257 		if (likely(cxgbit_skcb_flags(skb) & SKCBF_TX_NEED_HDR)) {
258 			len += cxgbit_skcb_tx_extralen(skb);
259 
260 			if ((csk->wr_una_cred >= (csk->wr_max_cred / 2)) ||
261 			    (!before(csk->write_seq,
262 				     csk->snd_una + csk->snd_win))) {
263 				compl = 1;
264 				csk->wr_una_cred = 0;
265 			}
266 
267 			cxgbit_tx_data_wr(csk, skb, dlen, len, credits_needed,
268 					  compl);
269 			csk->snd_nxt += len;
270 
271 		} else if ((cxgbit_skcb_flags(skb) & SKCBF_TX_FLAG_COMPL) ||
272 			   (csk->wr_una_cred >= (csk->wr_max_cred / 2))) {
273 			struct cpl_close_con_req *req =
274 				(struct cpl_close_con_req *)skb->data;
275 			req->wr.wr_hi |= htonl(FW_WR_COMPL_F);
276 			csk->wr_una_cred = 0;
277 		}
278 
279 		cxgbit_sock_enqueue_wr(csk, skb);
280 		t4_set_arp_err_handler(skb, csk,
281 				       cxgbit_arp_failure_skb_discard);
282 
283 		pr_debug("csk 0x%p,%u, skb 0x%p, %u.\n",
284 			 csk, csk->tid, skb, len);
285 
286 		cxgbit_l2t_send(csk->com.cdev, skb, csk->l2t);
287 	}
288 }
289 
290 static bool cxgbit_lock_sock(struct cxgbit_sock *csk)
291 {
292 	spin_lock_bh(&csk->lock);
293 
294 	if (before(csk->write_seq, csk->snd_una + csk->snd_win))
295 		csk->lock_owner = true;
296 
297 	spin_unlock_bh(&csk->lock);
298 
299 	return csk->lock_owner;
300 }
301 
302 static void cxgbit_unlock_sock(struct cxgbit_sock *csk)
303 {
304 	struct sk_buff_head backlogq;
305 	struct sk_buff *skb;
306 	void (*fn)(struct cxgbit_sock *, struct sk_buff *);
307 
308 	skb_queue_head_init(&backlogq);
309 
310 	spin_lock_bh(&csk->lock);
311 	while (skb_queue_len(&csk->backlogq)) {
312 		skb_queue_splice_init(&csk->backlogq, &backlogq);
313 		spin_unlock_bh(&csk->lock);
314 
315 		while ((skb = __skb_dequeue(&backlogq))) {
316 			fn = cxgbit_skcb_rx_backlog_fn(skb);
317 			fn(csk, skb);
318 		}
319 
320 		spin_lock_bh(&csk->lock);
321 	}
322 
323 	csk->lock_owner = false;
324 	spin_unlock_bh(&csk->lock);
325 }
326 
327 static int cxgbit_queue_skb(struct cxgbit_sock *csk, struct sk_buff *skb)
328 {
329 	int ret = 0;
330 
331 	wait_event_interruptible(csk->ack_waitq, cxgbit_lock_sock(csk));
332 
333 	if (unlikely((csk->com.state != CSK_STATE_ESTABLISHED) ||
334 		     signal_pending(current))) {
335 		__kfree_skb(skb);
336 		__skb_queue_purge(&csk->ppodq);
337 		ret = -1;
338 		spin_lock_bh(&csk->lock);
339 		if (csk->lock_owner) {
340 			spin_unlock_bh(&csk->lock);
341 			goto unlock;
342 		}
343 		spin_unlock_bh(&csk->lock);
344 		return ret;
345 	}
346 
347 	csk->write_seq += skb->len +
348 			  cxgbit_skcb_tx_extralen(skb);
349 
350 	skb_queue_splice_tail_init(&csk->ppodq, &csk->txq);
351 	__skb_queue_tail(&csk->txq, skb);
352 	cxgbit_push_tx_frames(csk);
353 
354 unlock:
355 	cxgbit_unlock_sock(csk);
356 	return ret;
357 }
358 
359 static int
360 cxgbit_map_skb(struct iscsi_cmd *cmd, struct sk_buff *skb, u32 data_offset,
361 	       u32 data_length)
362 {
363 	u32 i = 0, nr_frags = MAX_SKB_FRAGS;
364 	u32 padding = ((-data_length) & 3);
365 	struct scatterlist *sg;
366 	struct page *page;
367 	unsigned int page_off;
368 
369 	if (padding)
370 		nr_frags--;
371 
372 	/*
373 	 * We know each entry in t_data_sg contains a page.
374 	 */
375 	sg = &cmd->se_cmd.t_data_sg[data_offset / PAGE_SIZE];
376 	page_off = (data_offset % PAGE_SIZE);
377 
378 	while (data_length && (i < nr_frags)) {
379 		u32 cur_len = min_t(u32, data_length, sg->length - page_off);
380 
381 		page = sg_page(sg);
382 
383 		get_page(page);
384 		skb_fill_page_desc(skb, i, page, sg->offset + page_off,
385 				   cur_len);
386 		skb->data_len += cur_len;
387 		skb->len += cur_len;
388 		skb->truesize += cur_len;
389 
390 		data_length -= cur_len;
391 		page_off = 0;
392 		sg = sg_next(sg);
393 		i++;
394 	}
395 
396 	if (data_length)
397 		return -1;
398 
399 	if (padding) {
400 		page = alloc_page(GFP_KERNEL | __GFP_ZERO);
401 		if (!page)
402 			return -1;
403 		skb_fill_page_desc(skb, i, page, 0, padding);
404 		skb->data_len += padding;
405 		skb->len += padding;
406 		skb->truesize += padding;
407 	}
408 
409 	return 0;
410 }
411 
412 static int
413 cxgbit_tx_datain_iso(struct cxgbit_sock *csk, struct iscsi_cmd *cmd,
414 		     struct iscsi_datain_req *dr)
415 {
416 	struct iscsi_conn *conn = csk->conn;
417 	struct sk_buff *skb;
418 	struct iscsi_datain datain;
419 	struct cxgbit_iso_info iso_info;
420 	u32 data_length = cmd->se_cmd.data_length;
421 	u32 mrdsl = conn->conn_ops->MaxRecvDataSegmentLength;
422 	u32 num_pdu, plen, tx_data = 0;
423 	bool task_sense = !!(cmd->se_cmd.se_cmd_flags &
424 		SCF_TRANSPORT_TASK_SENSE);
425 	bool set_statsn = false;
426 	int ret = -1;
427 
428 	while (data_length) {
429 		num_pdu = (data_length + mrdsl - 1) / mrdsl;
430 		if (num_pdu > csk->max_iso_npdu)
431 			num_pdu = csk->max_iso_npdu;
432 
433 		plen = num_pdu * mrdsl;
434 		if (plen > data_length)
435 			plen = data_length;
436 
437 		skb = __cxgbit_alloc_skb(csk, 0, true);
438 		if (unlikely(!skb))
439 			return -ENOMEM;
440 
441 		memset(skb->data, 0, ISCSI_HDR_LEN);
442 		cxgbit_skcb_flags(skb) |= SKCBF_TX_ISO;
443 		cxgbit_skcb_submode(skb) |= (csk->submode &
444 				CXGBIT_SUBMODE_DCRC);
445 		cxgbit_skcb_tx_extralen(skb) = (num_pdu *
446 				cxgbit_digest_len[cxgbit_skcb_submode(skb)]) +
447 						((num_pdu - 1) * ISCSI_HDR_LEN);
448 
449 		memset(&datain, 0, sizeof(struct iscsi_datain));
450 		memset(&iso_info, 0, sizeof(iso_info));
451 
452 		if (!tx_data)
453 			iso_info.flags |= CXGBIT_ISO_FSLICE;
454 
455 		if (!(data_length - plen)) {
456 			iso_info.flags |= CXGBIT_ISO_LSLICE;
457 			if (!task_sense) {
458 				datain.flags = ISCSI_FLAG_DATA_STATUS;
459 				iscsit_increment_maxcmdsn(cmd, conn->sess);
460 				cmd->stat_sn = conn->stat_sn++;
461 				set_statsn = true;
462 			}
463 		}
464 
465 		iso_info.burst_len = num_pdu * mrdsl;
466 		iso_info.mpdu = mrdsl;
467 		iso_info.len = ISCSI_HDR_LEN + plen;
468 
469 		cxgbit_cpl_tx_data_iso(skb, &iso_info);
470 
471 		datain.offset = tx_data;
472 		datain.data_sn = cmd->data_sn - 1;
473 
474 		iscsit_build_datain_pdu(cmd, conn, &datain,
475 					(struct iscsi_data_rsp *)skb->data,
476 					set_statsn);
477 
478 		ret = cxgbit_map_skb(cmd, skb, tx_data, plen);
479 		if (unlikely(ret)) {
480 			__kfree_skb(skb);
481 			goto out;
482 		}
483 
484 		ret = cxgbit_queue_skb(csk, skb);
485 		if (unlikely(ret))
486 			goto out;
487 
488 		tx_data += plen;
489 		data_length -= plen;
490 
491 		cmd->read_data_done += plen;
492 		cmd->data_sn += num_pdu;
493 	}
494 
495 	dr->dr_complete = DATAIN_COMPLETE_NORMAL;
496 
497 	return 0;
498 
499 out:
500 	return ret;
501 }
502 
503 static int
504 cxgbit_tx_datain(struct cxgbit_sock *csk, struct iscsi_cmd *cmd,
505 		 const struct iscsi_datain *datain)
506 {
507 	struct sk_buff *skb;
508 	int ret = 0;
509 
510 	skb = cxgbit_alloc_skb(csk, 0);
511 	if (unlikely(!skb))
512 		return -ENOMEM;
513 
514 	memcpy(skb->data, cmd->pdu, ISCSI_HDR_LEN);
515 
516 	if (datain->length) {
517 		cxgbit_skcb_submode(skb) |= (csk->submode &
518 				CXGBIT_SUBMODE_DCRC);
519 		cxgbit_skcb_tx_extralen(skb) =
520 				cxgbit_digest_len[cxgbit_skcb_submode(skb)];
521 	}
522 
523 	ret = cxgbit_map_skb(cmd, skb, datain->offset, datain->length);
524 	if (ret < 0) {
525 		__kfree_skb(skb);
526 		return ret;
527 	}
528 
529 	return cxgbit_queue_skb(csk, skb);
530 }
531 
532 static int
533 cxgbit_xmit_datain_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
534 		       struct iscsi_datain_req *dr,
535 		       const struct iscsi_datain *datain)
536 {
537 	struct cxgbit_sock *csk = conn->context;
538 	u32 data_length = cmd->se_cmd.data_length;
539 	u32 padding = ((-data_length) & 3);
540 	u32 mrdsl = conn->conn_ops->MaxRecvDataSegmentLength;
541 
542 	if ((data_length > mrdsl) && (!dr->recovery) &&
543 	    (!padding) && (!datain->offset) && csk->max_iso_npdu) {
544 		atomic_long_add(data_length - datain->length,
545 				&conn->sess->tx_data_octets);
546 		return cxgbit_tx_datain_iso(csk, cmd, dr);
547 	}
548 
549 	return cxgbit_tx_datain(csk, cmd, datain);
550 }
551 
552 static int
553 cxgbit_xmit_nondatain_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
554 			  const void *data_buf, u32 data_buf_len)
555 {
556 	struct cxgbit_sock *csk = conn->context;
557 	struct sk_buff *skb;
558 	u32 padding = ((-data_buf_len) & 3);
559 
560 	skb = cxgbit_alloc_skb(csk, data_buf_len + padding);
561 	if (unlikely(!skb))
562 		return -ENOMEM;
563 
564 	memcpy(skb->data, cmd->pdu, ISCSI_HDR_LEN);
565 
566 	if (data_buf_len) {
567 		u32 pad_bytes = 0;
568 
569 		skb_store_bits(skb, ISCSI_HDR_LEN, data_buf, data_buf_len);
570 
571 		if (padding)
572 			skb_store_bits(skb, ISCSI_HDR_LEN + data_buf_len,
573 				       &pad_bytes, padding);
574 	}
575 
576 	cxgbit_skcb_tx_extralen(skb) = cxgbit_digest_len[
577 				       cxgbit_skcb_submode(skb)];
578 
579 	return cxgbit_queue_skb(csk, skb);
580 }
581 
582 int
583 cxgbit_xmit_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
584 		struct iscsi_datain_req *dr, const void *buf, u32 buf_len)
585 {
586 	if (dr)
587 		return cxgbit_xmit_datain_pdu(conn, cmd, dr, buf);
588 	else
589 		return cxgbit_xmit_nondatain_pdu(conn, cmd, buf, buf_len);
590 }
591 
592 int cxgbit_validate_params(struct iscsi_conn *conn)
593 {
594 	struct cxgbit_sock *csk = conn->context;
595 	struct cxgbit_device *cdev = csk->com.cdev;
596 	struct iscsi_param *param;
597 	u32 max_xmitdsl;
598 
599 	param = iscsi_find_param_from_key(MAXXMITDATASEGMENTLENGTH,
600 					  conn->param_list);
601 	if (!param)
602 		return -1;
603 
604 	if (kstrtou32(param->value, 0, &max_xmitdsl) < 0)
605 		return -1;
606 
607 	if (max_xmitdsl > cdev->mdsl) {
608 		if (iscsi_change_param_sprintf(
609 			conn, "MaxXmitDataSegmentLength=%u", cdev->mdsl))
610 			return -1;
611 	}
612 
613 	return 0;
614 }
615 
616 static int cxgbit_set_digest(struct cxgbit_sock *csk)
617 {
618 	struct iscsi_conn *conn = csk->conn;
619 	struct iscsi_param *param;
620 
621 	param = iscsi_find_param_from_key(HEADERDIGEST, conn->param_list);
622 	if (!param) {
623 		pr_err("param not found key %s\n", HEADERDIGEST);
624 		return -1;
625 	}
626 
627 	if (!strcmp(param->value, CRC32C))
628 		csk->submode |= CXGBIT_SUBMODE_HCRC;
629 
630 	param = iscsi_find_param_from_key(DATADIGEST, conn->param_list);
631 	if (!param) {
632 		csk->submode = 0;
633 		pr_err("param not found key %s\n", DATADIGEST);
634 		return -1;
635 	}
636 
637 	if (!strcmp(param->value, CRC32C))
638 		csk->submode |= CXGBIT_SUBMODE_DCRC;
639 
640 	if (cxgbit_setup_conn_digest(csk)) {
641 		csk->submode = 0;
642 		return -1;
643 	}
644 
645 	return 0;
646 }
647 
648 static int cxgbit_set_iso_npdu(struct cxgbit_sock *csk)
649 {
650 	struct iscsi_conn *conn = csk->conn;
651 	struct iscsi_conn_ops *conn_ops = conn->conn_ops;
652 	struct iscsi_param *param;
653 	u32 mrdsl, mbl;
654 	u32 max_npdu, max_iso_npdu;
655 	u32 max_iso_payload;
656 
657 	if (conn->login->leading_connection) {
658 		param = iscsi_find_param_from_key(MAXBURSTLENGTH,
659 						  conn->param_list);
660 		if (!param) {
661 			pr_err("param not found key %s\n", MAXBURSTLENGTH);
662 			return -1;
663 		}
664 
665 		if (kstrtou32(param->value, 0, &mbl) < 0)
666 			return -1;
667 	} else {
668 		mbl = conn->sess->sess_ops->MaxBurstLength;
669 	}
670 
671 	mrdsl = conn_ops->MaxRecvDataSegmentLength;
672 	max_npdu = mbl / mrdsl;
673 
674 	max_iso_payload = rounddown(CXGBIT_MAX_ISO_PAYLOAD, csk->emss);
675 
676 	max_iso_npdu = max_iso_payload /
677 		       (ISCSI_HDR_LEN + mrdsl +
678 			cxgbit_digest_len[csk->submode]);
679 
680 	csk->max_iso_npdu = min(max_npdu, max_iso_npdu);
681 
682 	if (csk->max_iso_npdu <= 1)
683 		csk->max_iso_npdu = 0;
684 
685 	return 0;
686 }
687 
688 /*
689  * cxgbit_seq_pdu_inorder()
690  * @csk: pointer to cxgbit socket structure
691  *
692  * This function checks whether data sequence and data
693  * pdu are in order.
694  *
695  * Return: returns -1 on error, 0 if data sequence and
696  * data pdu are in order, 1 if data sequence or data pdu
697  * is not in order.
698  */
699 static int cxgbit_seq_pdu_inorder(struct cxgbit_sock *csk)
700 {
701 	struct iscsi_conn *conn = csk->conn;
702 	struct iscsi_param *param;
703 
704 	if (conn->login->leading_connection) {
705 		param = iscsi_find_param_from_key(DATASEQUENCEINORDER,
706 						  conn->param_list);
707 		if (!param) {
708 			pr_err("param not found key %s\n", DATASEQUENCEINORDER);
709 			return -1;
710 		}
711 
712 		if (strcmp(param->value, YES))
713 			return 1;
714 
715 		param = iscsi_find_param_from_key(DATAPDUINORDER,
716 						  conn->param_list);
717 		if (!param) {
718 			pr_err("param not found key %s\n", DATAPDUINORDER);
719 			return -1;
720 		}
721 
722 		if (strcmp(param->value, YES))
723 			return 1;
724 
725 	} else {
726 		if (!conn->sess->sess_ops->DataSequenceInOrder)
727 			return 1;
728 		if (!conn->sess->sess_ops->DataPDUInOrder)
729 			return 1;
730 	}
731 
732 	return 0;
733 }
734 
735 static int cxgbit_set_params(struct iscsi_conn *conn)
736 {
737 	struct cxgbit_sock *csk = conn->context;
738 	struct cxgbit_device *cdev = csk->com.cdev;
739 	struct cxgbi_ppm *ppm = *csk->com.cdev->lldi.iscsi_ppm;
740 	struct iscsi_conn_ops *conn_ops = conn->conn_ops;
741 	struct iscsi_param *param;
742 	u8 erl;
743 
744 	if (conn_ops->MaxRecvDataSegmentLength > cdev->mdsl)
745 		conn_ops->MaxRecvDataSegmentLength = cdev->mdsl;
746 
747 	if (cxgbit_set_digest(csk))
748 		return -1;
749 
750 	if (conn->login->leading_connection) {
751 		param = iscsi_find_param_from_key(ERRORRECOVERYLEVEL,
752 						  conn->param_list);
753 		if (!param) {
754 			pr_err("param not found key %s\n", ERRORRECOVERYLEVEL);
755 			return -1;
756 		}
757 		if (kstrtou8(param->value, 0, &erl) < 0)
758 			return -1;
759 	} else {
760 		erl = conn->sess->sess_ops->ErrorRecoveryLevel;
761 	}
762 
763 	if (!erl) {
764 		int ret;
765 
766 		ret = cxgbit_seq_pdu_inorder(csk);
767 		if (ret < 0) {
768 			return -1;
769 		} else if (ret > 0) {
770 			if (is_t5(cdev->lldi.adapter_type))
771 				goto enable_ddp;
772 			else
773 				return 0;
774 		}
775 
776 		if (test_bit(CDEV_ISO_ENABLE, &cdev->flags)) {
777 			if (cxgbit_set_iso_npdu(csk))
778 				return -1;
779 		}
780 
781 enable_ddp:
782 		if (test_bit(CDEV_DDP_ENABLE, &cdev->flags)) {
783 			if (cxgbit_setup_conn_pgidx(csk,
784 						    ppm->tformat.pgsz_idx_dflt))
785 				return -1;
786 			set_bit(CSK_DDP_ENABLE, &csk->com.flags);
787 		}
788 	}
789 
790 	return 0;
791 }
792 
793 int
794 cxgbit_put_login_tx(struct iscsi_conn *conn, struct iscsi_login *login,
795 		    u32 length)
796 {
797 	struct cxgbit_sock *csk = conn->context;
798 	struct sk_buff *skb;
799 	u32 padding_buf = 0;
800 	u8 padding = ((-length) & 3);
801 
802 	skb = cxgbit_alloc_skb(csk, length + padding);
803 	if (!skb)
804 		return -ENOMEM;
805 	skb_store_bits(skb, 0, login->rsp, ISCSI_HDR_LEN);
806 	skb_store_bits(skb, ISCSI_HDR_LEN, login->rsp_buf, length);
807 
808 	if (padding)
809 		skb_store_bits(skb, ISCSI_HDR_LEN + length,
810 			       &padding_buf, padding);
811 
812 	if (login->login_complete) {
813 		if (cxgbit_set_params(conn)) {
814 			kfree_skb(skb);
815 			return -1;
816 		}
817 
818 		set_bit(CSK_LOGIN_DONE, &csk->com.flags);
819 	}
820 
821 	if (cxgbit_queue_skb(csk, skb))
822 		return -1;
823 
824 	if ((!login->login_complete) && (!login->login_failed))
825 		schedule_delayed_work(&conn->login_work, 0);
826 
827 	return 0;
828 }
829 
830 static void
831 cxgbit_skb_copy_to_sg(struct sk_buff *skb, struct scatterlist *sg,
832 		      unsigned int nents, u32 skip)
833 {
834 	struct skb_seq_state st;
835 	const u8 *buf;
836 	unsigned int consumed = 0, buf_len;
837 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(skb);
838 
839 	skb_prepare_seq_read(skb, pdu_cb->doffset,
840 			     pdu_cb->doffset + pdu_cb->dlen,
841 			     &st);
842 
843 	while (true) {
844 		buf_len = skb_seq_read(consumed, &buf, &st);
845 		if (!buf_len) {
846 			skb_abort_seq_read(&st);
847 			break;
848 		}
849 
850 		consumed += sg_pcopy_from_buffer(sg, nents, (void *)buf,
851 						 buf_len, skip + consumed);
852 	}
853 }
854 
855 static struct iscsi_cmd *cxgbit_allocate_cmd(struct cxgbit_sock *csk)
856 {
857 	struct iscsi_conn *conn = csk->conn;
858 	struct cxgbi_ppm *ppm = cdev2ppm(csk->com.cdev);
859 	struct cxgbit_cmd *ccmd;
860 	struct iscsi_cmd *cmd;
861 
862 	cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
863 	if (!cmd) {
864 		pr_err("Unable to allocate iscsi_cmd + cxgbit_cmd\n");
865 		return NULL;
866 	}
867 
868 	ccmd = iscsit_priv_cmd(cmd);
869 	ccmd->ttinfo.tag = ppm->tformat.no_ddp_mask;
870 	ccmd->setup_ddp = true;
871 
872 	return cmd;
873 }
874 
875 static int
876 cxgbit_handle_immediate_data(struct iscsi_cmd *cmd, struct iscsi_scsi_req *hdr,
877 			     u32 length)
878 {
879 	struct iscsi_conn *conn = cmd->conn;
880 	struct cxgbit_sock *csk = conn->context;
881 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
882 
883 	if (pdu_cb->flags & PDUCBF_RX_DCRC_ERR) {
884 		pr_err("ImmediateData CRC32C DataDigest error\n");
885 		if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
886 			pr_err("Unable to recover from"
887 			       " Immediate Data digest failure while"
888 			       " in ERL=0.\n");
889 			iscsit_reject_cmd(cmd, ISCSI_REASON_DATA_DIGEST_ERROR,
890 					  (unsigned char *)hdr);
891 			return IMMEDIATE_DATA_CANNOT_RECOVER;
892 		}
893 
894 		iscsit_reject_cmd(cmd, ISCSI_REASON_DATA_DIGEST_ERROR,
895 				  (unsigned char *)hdr);
896 		return IMMEDIATE_DATA_ERL1_CRC_FAILURE;
897 	}
898 
899 	if (cmd->se_cmd.se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
900 		struct cxgbit_cmd *ccmd = iscsit_priv_cmd(cmd);
901 		struct skb_shared_info *ssi = skb_shinfo(csk->skb);
902 		skb_frag_t *dfrag = &ssi->frags[pdu_cb->dfrag_idx];
903 
904 		sg_init_table(&ccmd->sg, 1);
905 		sg_set_page(&ccmd->sg, dfrag->page.p, skb_frag_size(dfrag),
906 			    dfrag->page_offset);
907 		get_page(dfrag->page.p);
908 
909 		cmd->se_cmd.t_data_sg = &ccmd->sg;
910 		cmd->se_cmd.t_data_nents = 1;
911 
912 		ccmd->release = true;
913 	} else {
914 		struct scatterlist *sg = &cmd->se_cmd.t_data_sg[0];
915 		u32 sg_nents = max(1UL, DIV_ROUND_UP(pdu_cb->dlen, PAGE_SIZE));
916 
917 		cxgbit_skb_copy_to_sg(csk->skb, sg, sg_nents, 0);
918 	}
919 
920 	cmd->write_data_done += pdu_cb->dlen;
921 
922 	if (cmd->write_data_done == cmd->se_cmd.data_length) {
923 		spin_lock_bh(&cmd->istate_lock);
924 		cmd->cmd_flags |= ICF_GOT_LAST_DATAOUT;
925 		cmd->i_state = ISTATE_RECEIVED_LAST_DATAOUT;
926 		spin_unlock_bh(&cmd->istate_lock);
927 	}
928 
929 	return IMMEDIATE_DATA_NORMAL_OPERATION;
930 }
931 
932 static int
933 cxgbit_get_immediate_data(struct iscsi_cmd *cmd, struct iscsi_scsi_req *hdr,
934 			  bool dump_payload)
935 {
936 	struct iscsi_conn *conn = cmd->conn;
937 	int cmdsn_ret = 0, immed_ret = IMMEDIATE_DATA_NORMAL_OPERATION;
938 	/*
939 	 * Special case for Unsupported SAM WRITE Opcodes and ImmediateData=Yes.
940 	 */
941 	if (dump_payload)
942 		goto after_immediate_data;
943 
944 	immed_ret = cxgbit_handle_immediate_data(cmd, hdr,
945 						 cmd->first_burst_len);
946 after_immediate_data:
947 	if (immed_ret == IMMEDIATE_DATA_NORMAL_OPERATION) {
948 		/*
949 		 * A PDU/CmdSN carrying Immediate Data passed
950 		 * DataCRC, check against ExpCmdSN/MaxCmdSN if
951 		 * Immediate Bit is not set.
952 		 */
953 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd,
954 						(unsigned char *)hdr,
955 						hdr->cmdsn);
956 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
957 			return -1;
958 
959 		if (cmd->sense_reason || cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
960 			target_put_sess_cmd(&cmd->se_cmd);
961 			return 0;
962 		} else if (cmd->unsolicited_data) {
963 			iscsit_set_unsoliticed_dataout(cmd);
964 		}
965 
966 	} else if (immed_ret == IMMEDIATE_DATA_ERL1_CRC_FAILURE) {
967 		/*
968 		 * Immediate Data failed DataCRC and ERL>=1,
969 		 * silently drop this PDU and let the initiator
970 		 * plug the CmdSN gap.
971 		 *
972 		 * FIXME: Send Unsolicited NOPIN with reserved
973 		 * TTT here to help the initiator figure out
974 		 * the missing CmdSN, although they should be
975 		 * intelligent enough to determine the missing
976 		 * CmdSN and issue a retry to plug the sequence.
977 		 */
978 		cmd->i_state = ISTATE_REMOVE;
979 		iscsit_add_cmd_to_immediate_queue(cmd, conn, cmd->i_state);
980 	} else /* immed_ret == IMMEDIATE_DATA_CANNOT_RECOVER */
981 		return -1;
982 
983 	return 0;
984 }
985 
986 static int
987 cxgbit_handle_scsi_cmd(struct cxgbit_sock *csk, struct iscsi_cmd *cmd)
988 {
989 	struct iscsi_conn *conn = csk->conn;
990 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
991 	struct iscsi_scsi_req *hdr = (struct iscsi_scsi_req *)pdu_cb->hdr;
992 	int rc;
993 	bool dump_payload = false;
994 
995 	rc = iscsit_setup_scsi_cmd(conn, cmd, (unsigned char *)hdr);
996 	if (rc < 0)
997 		return rc;
998 
999 	if (pdu_cb->dlen && (pdu_cb->dlen == cmd->se_cmd.data_length) &&
1000 	    (pdu_cb->nr_dfrags == 1))
1001 		cmd->se_cmd.se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1002 
1003 	rc = iscsit_process_scsi_cmd(conn, cmd, hdr);
1004 	if (rc < 0)
1005 		return 0;
1006 	else if (rc > 0)
1007 		dump_payload = true;
1008 
1009 	if (!pdu_cb->dlen)
1010 		return 0;
1011 
1012 	return cxgbit_get_immediate_data(cmd, hdr, dump_payload);
1013 }
1014 
1015 static int cxgbit_handle_iscsi_dataout(struct cxgbit_sock *csk)
1016 {
1017 	struct scatterlist *sg_start;
1018 	struct iscsi_conn *conn = csk->conn;
1019 	struct iscsi_cmd *cmd = NULL;
1020 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
1021 	struct iscsi_data *hdr = (struct iscsi_data *)pdu_cb->hdr;
1022 	u32 data_offset = be32_to_cpu(hdr->offset);
1023 	u32 data_len = pdu_cb->dlen;
1024 	int rc, sg_nents, sg_off;
1025 	bool dcrc_err = false;
1026 
1027 	if (pdu_cb->flags & PDUCBF_RX_DDP_CMP) {
1028 		u32 offset = be32_to_cpu(hdr->offset);
1029 		u32 ddp_data_len;
1030 		u32 payload_length = ntoh24(hdr->dlength);
1031 		bool success = false;
1032 
1033 		cmd = iscsit_find_cmd_from_itt_or_dump(conn, hdr->itt, 0);
1034 		if (!cmd)
1035 			return 0;
1036 
1037 		ddp_data_len = offset - cmd->write_data_done;
1038 		atomic_long_add(ddp_data_len, &conn->sess->rx_data_octets);
1039 
1040 		cmd->write_data_done = offset;
1041 		cmd->next_burst_len = ddp_data_len;
1042 		cmd->data_sn = be32_to_cpu(hdr->datasn);
1043 
1044 		rc = __iscsit_check_dataout_hdr(conn, (unsigned char *)hdr,
1045 						cmd, payload_length, &success);
1046 		if (rc < 0)
1047 			return rc;
1048 		else if (!success)
1049 			return 0;
1050 	} else {
1051 		rc = iscsit_check_dataout_hdr(conn, (unsigned char *)hdr, &cmd);
1052 		if (rc < 0)
1053 			return rc;
1054 		else if (!cmd)
1055 			return 0;
1056 	}
1057 
1058 	if (pdu_cb->flags & PDUCBF_RX_DCRC_ERR) {
1059 		pr_err("ITT: 0x%08x, Offset: %u, Length: %u,"
1060 		       " DataSN: 0x%08x\n",
1061 		       hdr->itt, hdr->offset, data_len,
1062 		       hdr->datasn);
1063 
1064 		dcrc_err = true;
1065 		goto check_payload;
1066 	}
1067 
1068 	pr_debug("DataOut data_len: %u, "
1069 		"write_data_done: %u, data_length: %u\n",
1070 		  data_len,  cmd->write_data_done,
1071 		  cmd->se_cmd.data_length);
1072 
1073 	if (!(pdu_cb->flags & PDUCBF_RX_DATA_DDPD)) {
1074 		u32 skip = data_offset % PAGE_SIZE;
1075 
1076 		sg_off = data_offset / PAGE_SIZE;
1077 		sg_start = &cmd->se_cmd.t_data_sg[sg_off];
1078 		sg_nents = max(1UL, DIV_ROUND_UP(skip + data_len, PAGE_SIZE));
1079 
1080 		cxgbit_skb_copy_to_sg(csk->skb, sg_start, sg_nents, skip);
1081 	}
1082 
1083 check_payload:
1084 
1085 	rc = iscsit_check_dataout_payload(cmd, hdr, dcrc_err);
1086 	if (rc < 0)
1087 		return rc;
1088 
1089 	return 0;
1090 }
1091 
1092 static int cxgbit_handle_nop_out(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_nopout *hdr = (struct iscsi_nopout *)pdu_cb->hdr;
1097 	unsigned char *ping_data = NULL;
1098 	u32 payload_length = pdu_cb->dlen;
1099 	int ret;
1100 
1101 	ret = iscsit_setup_nop_out(conn, cmd, hdr);
1102 	if (ret < 0)
1103 		return 0;
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 			       " NOPOUT Ping DataCRC failure while in"
1109 			       " ERL=0.\n");
1110 			ret = -1;
1111 			goto out;
1112 		} else {
1113 			/*
1114 			 * drop this PDU and let the
1115 			 * initiator plug the CmdSN gap.
1116 			 */
1117 			pr_info("Dropping NOPOUT"
1118 				" Command CmdSN: 0x%08x due to"
1119 				" DataCRC error.\n", hdr->cmdsn);
1120 			ret = 0;
1121 			goto out;
1122 		}
1123 	}
1124 
1125 	/*
1126 	 * Handle NOP-OUT payload for traditional iSCSI sockets
1127 	 */
1128 	if (payload_length && hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
1129 		ping_data = kzalloc(payload_length + 1, GFP_KERNEL);
1130 		if (!ping_data) {
1131 			pr_err("Unable to allocate memory for"
1132 				" NOPOUT ping data.\n");
1133 			ret = -1;
1134 			goto out;
1135 		}
1136 
1137 		skb_copy_bits(csk->skb, pdu_cb->doffset,
1138 			      ping_data, payload_length);
1139 
1140 		ping_data[payload_length] = '\0';
1141 		/*
1142 		 * Attach ping data to struct iscsi_cmd->buf_ptr.
1143 		 */
1144 		cmd->buf_ptr = ping_data;
1145 		cmd->buf_ptr_size = payload_length;
1146 
1147 		pr_debug("Got %u bytes of NOPOUT ping"
1148 			" data.\n", payload_length);
1149 		pr_debug("Ping Data: \"%s\"\n", ping_data);
1150 	}
1151 
1152 	return iscsit_process_nop_out(conn, cmd, hdr);
1153 out:
1154 	if (cmd)
1155 		iscsit_free_cmd(cmd, false);
1156 	return ret;
1157 }
1158 
1159 static int
1160 cxgbit_handle_text_cmd(struct cxgbit_sock *csk, struct iscsi_cmd *cmd)
1161 {
1162 	struct iscsi_conn *conn = csk->conn;
1163 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
1164 	struct iscsi_text *hdr = (struct iscsi_text *)pdu_cb->hdr;
1165 	u32 payload_length = pdu_cb->dlen;
1166 	int rc;
1167 	unsigned char *text_in = NULL;
1168 
1169 	rc = iscsit_setup_text_cmd(conn, cmd, hdr);
1170 	if (rc < 0)
1171 		return rc;
1172 
1173 	if (pdu_cb->flags & PDUCBF_RX_DCRC_ERR) {
1174 		if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
1175 			pr_err("Unable to recover from"
1176 			       " Text Data digest failure while in"
1177 			       " ERL=0.\n");
1178 			goto reject;
1179 		} else {
1180 			/*
1181 			 * drop this PDU and let the
1182 			 * initiator plug the CmdSN gap.
1183 			 */
1184 			pr_info("Dropping Text"
1185 				" Command CmdSN: 0x%08x due to"
1186 				" DataCRC error.\n", hdr->cmdsn);
1187 			return 0;
1188 		}
1189 	}
1190 
1191 	if (payload_length) {
1192 		text_in = kzalloc(payload_length, GFP_KERNEL);
1193 		if (!text_in) {
1194 			pr_err("Unable to allocate text_in of payload_length: %u\n",
1195 			       payload_length);
1196 			return -ENOMEM;
1197 		}
1198 		skb_copy_bits(csk->skb, pdu_cb->doffset,
1199 			      text_in, payload_length);
1200 
1201 		text_in[payload_length - 1] = '\0';
1202 
1203 		cmd->text_in_ptr = text_in;
1204 	}
1205 
1206 	return iscsit_process_text_cmd(conn, cmd, hdr);
1207 
1208 reject:
1209 	return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
1210 				 pdu_cb->hdr);
1211 }
1212 
1213 static int cxgbit_target_rx_opcode(struct cxgbit_sock *csk)
1214 {
1215 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
1216 	struct iscsi_hdr *hdr = (struct iscsi_hdr *)pdu_cb->hdr;
1217 	struct iscsi_conn *conn = csk->conn;
1218 	struct iscsi_cmd *cmd = NULL;
1219 	u8 opcode = (hdr->opcode & ISCSI_OPCODE_MASK);
1220 	int ret = -EINVAL;
1221 
1222 	switch (opcode) {
1223 	case ISCSI_OP_SCSI_CMD:
1224 		cmd = cxgbit_allocate_cmd(csk);
1225 		if (!cmd)
1226 			goto reject;
1227 
1228 		ret = cxgbit_handle_scsi_cmd(csk, cmd);
1229 		break;
1230 	case ISCSI_OP_SCSI_DATA_OUT:
1231 		ret = cxgbit_handle_iscsi_dataout(csk);
1232 		break;
1233 	case ISCSI_OP_NOOP_OUT:
1234 		if (hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
1235 			cmd = cxgbit_allocate_cmd(csk);
1236 			if (!cmd)
1237 				goto reject;
1238 		}
1239 
1240 		ret = cxgbit_handle_nop_out(csk, cmd);
1241 		break;
1242 	case ISCSI_OP_SCSI_TMFUNC:
1243 		cmd = cxgbit_allocate_cmd(csk);
1244 		if (!cmd)
1245 			goto reject;
1246 
1247 		ret = iscsit_handle_task_mgt_cmd(conn, cmd,
1248 						 (unsigned char *)hdr);
1249 		break;
1250 	case ISCSI_OP_TEXT:
1251 		if (hdr->ttt != cpu_to_be32(0xFFFFFFFF)) {
1252 			cmd = iscsit_find_cmd_from_itt(conn, hdr->itt);
1253 			if (!cmd)
1254 				goto reject;
1255 		} else {
1256 			cmd = cxgbit_allocate_cmd(csk);
1257 			if (!cmd)
1258 				goto reject;
1259 		}
1260 
1261 		ret = cxgbit_handle_text_cmd(csk, cmd);
1262 		break;
1263 	case ISCSI_OP_LOGOUT:
1264 		cmd = cxgbit_allocate_cmd(csk);
1265 		if (!cmd)
1266 			goto reject;
1267 
1268 		ret = iscsit_handle_logout_cmd(conn, cmd, (unsigned char *)hdr);
1269 		if (ret > 0)
1270 			wait_for_completion_timeout(&conn->conn_logout_comp,
1271 						    SECONDS_FOR_LOGOUT_COMP
1272 						    * HZ);
1273 		break;
1274 	case ISCSI_OP_SNACK:
1275 		ret = iscsit_handle_snack(conn, (unsigned char *)hdr);
1276 		break;
1277 	default:
1278 		pr_err("Got unknown iSCSI OpCode: 0x%02x\n", opcode);
1279 		dump_stack();
1280 		break;
1281 	}
1282 
1283 	return ret;
1284 
1285 reject:
1286 	return iscsit_add_reject(conn, ISCSI_REASON_BOOKMARK_NO_RESOURCES,
1287 				 (unsigned char *)hdr);
1288 	return ret;
1289 }
1290 
1291 static int cxgbit_rx_opcode(struct cxgbit_sock *csk)
1292 {
1293 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
1294 	struct iscsi_conn *conn = csk->conn;
1295 	struct iscsi_hdr *hdr = pdu_cb->hdr;
1296 	u8 opcode;
1297 
1298 	if (pdu_cb->flags & PDUCBF_RX_HCRC_ERR) {
1299 		atomic_long_inc(&conn->sess->conn_digest_errors);
1300 		goto transport_err;
1301 	}
1302 
1303 	if (conn->conn_state == TARG_CONN_STATE_IN_LOGOUT)
1304 		goto transport_err;
1305 
1306 	opcode = hdr->opcode & ISCSI_OPCODE_MASK;
1307 
1308 	if (conn->sess->sess_ops->SessionType &&
1309 	    ((!(opcode & ISCSI_OP_TEXT)) ||
1310 	     (!(opcode & ISCSI_OP_LOGOUT)))) {
1311 		pr_err("Received illegal iSCSI Opcode: 0x%02x"
1312 			" while in Discovery Session, rejecting.\n", opcode);
1313 		iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1314 				  (unsigned char *)hdr);
1315 		goto transport_err;
1316 	}
1317 
1318 	if (cxgbit_target_rx_opcode(csk) < 0)
1319 		goto transport_err;
1320 
1321 	return 0;
1322 
1323 transport_err:
1324 	return -1;
1325 }
1326 
1327 static int cxgbit_rx_login_pdu(struct cxgbit_sock *csk)
1328 {
1329 	struct iscsi_conn *conn = csk->conn;
1330 	struct iscsi_login *login = conn->login;
1331 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
1332 	struct iscsi_login_req *login_req;
1333 
1334 	login_req = (struct iscsi_login_req *)login->req;
1335 	memcpy(login_req, pdu_cb->hdr, sizeof(*login_req));
1336 
1337 	pr_debug("Got Login Command, Flags 0x%02x, ITT: 0x%08x,"
1338 		" CmdSN: 0x%08x, ExpStatSN: 0x%08x, CID: %hu, Length: %u\n",
1339 		login_req->flags, login_req->itt, login_req->cmdsn,
1340 		login_req->exp_statsn, login_req->cid, pdu_cb->dlen);
1341 	/*
1342 	 * Setup the initial iscsi_login values from the leading
1343 	 * login request PDU.
1344 	 */
1345 	if (login->first_request) {
1346 		login_req = (struct iscsi_login_req *)login->req;
1347 		login->leading_connection = (!login_req->tsih) ? 1 : 0;
1348 		login->current_stage	= ISCSI_LOGIN_CURRENT_STAGE(
1349 				login_req->flags);
1350 		login->version_min	= login_req->min_version;
1351 		login->version_max	= login_req->max_version;
1352 		memcpy(login->isid, login_req->isid, 6);
1353 		login->cmd_sn		= be32_to_cpu(login_req->cmdsn);
1354 		login->init_task_tag	= login_req->itt;
1355 		login->initial_exp_statsn = be32_to_cpu(login_req->exp_statsn);
1356 		login->cid		= be16_to_cpu(login_req->cid);
1357 		login->tsih		= be16_to_cpu(login_req->tsih);
1358 	}
1359 
1360 	if (iscsi_target_check_login_request(conn, login) < 0)
1361 		return -1;
1362 
1363 	memset(login->req_buf, 0, MAX_KEY_VALUE_PAIRS);
1364 	skb_copy_bits(csk->skb, pdu_cb->doffset, login->req_buf, pdu_cb->dlen);
1365 
1366 	return 0;
1367 }
1368 
1369 static int
1370 cxgbit_process_iscsi_pdu(struct cxgbit_sock *csk, struct sk_buff *skb, int idx)
1371 {
1372 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_skb_lro_pdu_cb(skb, idx);
1373 	int ret;
1374 
1375 	cxgbit_rx_pdu_cb(skb) = pdu_cb;
1376 
1377 	csk->skb = skb;
1378 
1379 	if (!test_bit(CSK_LOGIN_DONE, &csk->com.flags)) {
1380 		ret = cxgbit_rx_login_pdu(csk);
1381 		set_bit(CSK_LOGIN_PDU_DONE, &csk->com.flags);
1382 	} else {
1383 		ret = cxgbit_rx_opcode(csk);
1384 	}
1385 
1386 	return ret;
1387 }
1388 
1389 static void cxgbit_lro_skb_dump(struct sk_buff *skb)
1390 {
1391 	struct skb_shared_info *ssi = skb_shinfo(skb);
1392 	struct cxgbit_lro_cb *lro_cb = cxgbit_skb_lro_cb(skb);
1393 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_skb_lro_pdu_cb(skb, 0);
1394 	u8 i;
1395 
1396 	pr_info("skb 0x%p, head 0x%p, 0x%p, len %u,%u, frags %u.\n",
1397 		skb, skb->head, skb->data, skb->len, skb->data_len,
1398 		ssi->nr_frags);
1399 	pr_info("skb 0x%p, lro_cb, csk 0x%p, pdu %u, %u.\n",
1400 		skb, lro_cb->csk, lro_cb->pdu_idx, lro_cb->pdu_totallen);
1401 
1402 	for (i = 0; i < lro_cb->pdu_idx; i++, pdu_cb++)
1403 		pr_info("skb 0x%p, pdu %d, %u, f 0x%x, seq 0x%x, dcrc 0x%x, "
1404 			"frags %u.\n",
1405 			skb, i, pdu_cb->pdulen, pdu_cb->flags, pdu_cb->seq,
1406 			pdu_cb->ddigest, pdu_cb->frags);
1407 	for (i = 0; i < ssi->nr_frags; i++)
1408 		pr_info("skb 0x%p, frag %d, off %u, sz %u.\n",
1409 			skb, i, ssi->frags[i].page_offset, ssi->frags[i].size);
1410 }
1411 
1412 static void cxgbit_lro_hskb_reset(struct cxgbit_sock *csk)
1413 {
1414 	struct sk_buff *skb = csk->lro_hskb;
1415 	struct skb_shared_info *ssi = skb_shinfo(skb);
1416 	u8 i;
1417 
1418 	memset(skb->data, 0, LRO_SKB_MIN_HEADROOM);
1419 	for (i = 0; i < ssi->nr_frags; i++)
1420 		put_page(skb_frag_page(&ssi->frags[i]));
1421 	ssi->nr_frags = 0;
1422 	skb->data_len = 0;
1423 	skb->truesize -= skb->len;
1424 	skb->len = 0;
1425 }
1426 
1427 static void
1428 cxgbit_lro_skb_merge(struct cxgbit_sock *csk, struct sk_buff *skb, u8 pdu_idx)
1429 {
1430 	struct sk_buff *hskb = csk->lro_hskb;
1431 	struct cxgbit_lro_pdu_cb *hpdu_cb = cxgbit_skb_lro_pdu_cb(hskb, 0);
1432 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_skb_lro_pdu_cb(skb, pdu_idx);
1433 	struct skb_shared_info *hssi = skb_shinfo(hskb);
1434 	struct skb_shared_info *ssi = skb_shinfo(skb);
1435 	unsigned int len = 0;
1436 
1437 	if (pdu_cb->flags & PDUCBF_RX_HDR) {
1438 		u8 hfrag_idx = hssi->nr_frags;
1439 
1440 		hpdu_cb->flags |= pdu_cb->flags;
1441 		hpdu_cb->seq = pdu_cb->seq;
1442 		hpdu_cb->hdr = pdu_cb->hdr;
1443 		hpdu_cb->hlen = pdu_cb->hlen;
1444 
1445 		memcpy(&hssi->frags[hfrag_idx], &ssi->frags[pdu_cb->hfrag_idx],
1446 		       sizeof(skb_frag_t));
1447 
1448 		get_page(skb_frag_page(&hssi->frags[hfrag_idx]));
1449 		hssi->nr_frags++;
1450 		hpdu_cb->frags++;
1451 		hpdu_cb->hfrag_idx = hfrag_idx;
1452 
1453 		len = hssi->frags[hfrag_idx].size;
1454 		hskb->len += len;
1455 		hskb->data_len += len;
1456 		hskb->truesize += len;
1457 	}
1458 
1459 	if (pdu_cb->flags & PDUCBF_RX_DATA) {
1460 		u8 dfrag_idx = hssi->nr_frags, i;
1461 
1462 		hpdu_cb->flags |= pdu_cb->flags;
1463 		hpdu_cb->dfrag_idx = dfrag_idx;
1464 
1465 		len = 0;
1466 		for (i = 0; i < pdu_cb->nr_dfrags; dfrag_idx++, i++) {
1467 			memcpy(&hssi->frags[dfrag_idx],
1468 			       &ssi->frags[pdu_cb->dfrag_idx + i],
1469 			       sizeof(skb_frag_t));
1470 
1471 			get_page(skb_frag_page(&hssi->frags[dfrag_idx]));
1472 
1473 			len += hssi->frags[dfrag_idx].size;
1474 
1475 			hssi->nr_frags++;
1476 			hpdu_cb->frags++;
1477 		}
1478 
1479 		hpdu_cb->dlen = pdu_cb->dlen;
1480 		hpdu_cb->doffset = hpdu_cb->hlen;
1481 		hpdu_cb->nr_dfrags = pdu_cb->nr_dfrags;
1482 		hskb->len += len;
1483 		hskb->data_len += len;
1484 		hskb->truesize += len;
1485 	}
1486 
1487 	if (pdu_cb->flags & PDUCBF_RX_STATUS) {
1488 		hpdu_cb->flags |= pdu_cb->flags;
1489 
1490 		if (hpdu_cb->flags & PDUCBF_RX_DATA)
1491 			hpdu_cb->flags &= ~PDUCBF_RX_DATA_DDPD;
1492 
1493 		hpdu_cb->ddigest = pdu_cb->ddigest;
1494 		hpdu_cb->pdulen = pdu_cb->pdulen;
1495 	}
1496 }
1497 
1498 static int cxgbit_process_lro_skb(struct cxgbit_sock *csk, struct sk_buff *skb)
1499 {
1500 	struct cxgbit_lro_cb *lro_cb = cxgbit_skb_lro_cb(skb);
1501 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_skb_lro_pdu_cb(skb, 0);
1502 	u8 pdu_idx = 0, last_idx = 0;
1503 	int ret = 0;
1504 
1505 	if (!pdu_cb->complete) {
1506 		cxgbit_lro_skb_merge(csk, skb, 0);
1507 
1508 		if (pdu_cb->flags & PDUCBF_RX_STATUS) {
1509 			struct sk_buff *hskb = csk->lro_hskb;
1510 
1511 			ret = cxgbit_process_iscsi_pdu(csk, hskb, 0);
1512 
1513 			cxgbit_lro_hskb_reset(csk);
1514 
1515 			if (ret < 0)
1516 				goto out;
1517 		}
1518 
1519 		pdu_idx = 1;
1520 	}
1521 
1522 	if (lro_cb->pdu_idx)
1523 		last_idx = lro_cb->pdu_idx - 1;
1524 
1525 	for (; pdu_idx <= last_idx; pdu_idx++) {
1526 		ret = cxgbit_process_iscsi_pdu(csk, skb, pdu_idx);
1527 		if (ret < 0)
1528 			goto out;
1529 	}
1530 
1531 	if ((!lro_cb->complete) && lro_cb->pdu_idx)
1532 		cxgbit_lro_skb_merge(csk, skb, lro_cb->pdu_idx);
1533 
1534 out:
1535 	return ret;
1536 }
1537 
1538 static int cxgbit_rx_lro_skb(struct cxgbit_sock *csk, struct sk_buff *skb)
1539 {
1540 	struct cxgbit_lro_cb *lro_cb = cxgbit_skb_lro_cb(skb);
1541 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_skb_lro_pdu_cb(skb, 0);
1542 	int ret = -1;
1543 
1544 	if ((pdu_cb->flags & PDUCBF_RX_HDR) &&
1545 	    (pdu_cb->seq != csk->rcv_nxt)) {
1546 		pr_info("csk 0x%p, tid 0x%x, seq 0x%x != 0x%x.\n",
1547 			csk, csk->tid, pdu_cb->seq, csk->rcv_nxt);
1548 		cxgbit_lro_skb_dump(skb);
1549 		return ret;
1550 	}
1551 
1552 	csk->rcv_nxt += lro_cb->pdu_totallen;
1553 
1554 	ret = cxgbit_process_lro_skb(csk, skb);
1555 
1556 	csk->rx_credits += lro_cb->pdu_totallen;
1557 
1558 	if (csk->rx_credits >= (csk->rcv_win / 4))
1559 		cxgbit_rx_data_ack(csk);
1560 
1561 	return ret;
1562 }
1563 
1564 static int cxgbit_rx_skb(struct cxgbit_sock *csk, struct sk_buff *skb)
1565 {
1566 	struct cxgb4_lld_info *lldi = &csk->com.cdev->lldi;
1567 	int ret = -1;
1568 
1569 	if (likely(cxgbit_skcb_flags(skb) & SKCBF_RX_LRO)) {
1570 		if (is_t5(lldi->adapter_type))
1571 			ret = cxgbit_rx_lro_skb(csk, skb);
1572 		else
1573 			ret = cxgbit_process_lro_skb(csk, skb);
1574 	}
1575 
1576 	__kfree_skb(skb);
1577 	return ret;
1578 }
1579 
1580 static bool cxgbit_rxq_len(struct cxgbit_sock *csk, struct sk_buff_head *rxq)
1581 {
1582 	spin_lock_bh(&csk->rxq.lock);
1583 	if (skb_queue_len(&csk->rxq)) {
1584 		skb_queue_splice_init(&csk->rxq, rxq);
1585 		spin_unlock_bh(&csk->rxq.lock);
1586 		return true;
1587 	}
1588 	spin_unlock_bh(&csk->rxq.lock);
1589 	return false;
1590 }
1591 
1592 static int cxgbit_wait_rxq(struct cxgbit_sock *csk)
1593 {
1594 	struct sk_buff *skb;
1595 	struct sk_buff_head rxq;
1596 
1597 	skb_queue_head_init(&rxq);
1598 
1599 	wait_event_interruptible(csk->waitq, cxgbit_rxq_len(csk, &rxq));
1600 
1601 	if (signal_pending(current))
1602 		goto out;
1603 
1604 	while ((skb = __skb_dequeue(&rxq))) {
1605 		if (cxgbit_rx_skb(csk, skb))
1606 			goto out;
1607 	}
1608 
1609 	return 0;
1610 out:
1611 	__skb_queue_purge(&rxq);
1612 	return -1;
1613 }
1614 
1615 int cxgbit_get_login_rx(struct iscsi_conn *conn, struct iscsi_login *login)
1616 {
1617 	struct cxgbit_sock *csk = conn->context;
1618 	int ret = -1;
1619 
1620 	while (!test_and_clear_bit(CSK_LOGIN_PDU_DONE, &csk->com.flags)) {
1621 		ret = cxgbit_wait_rxq(csk);
1622 		if (ret) {
1623 			clear_bit(CSK_LOGIN_PDU_DONE, &csk->com.flags);
1624 			break;
1625 		}
1626 	}
1627 
1628 	return ret;
1629 }
1630 
1631 void cxgbit_get_rx_pdu(struct iscsi_conn *conn)
1632 {
1633 	struct cxgbit_sock *csk = conn->context;
1634 
1635 	while (!kthread_should_stop()) {
1636 		iscsit_thread_check_cpumask(conn, current, 0);
1637 		if (cxgbit_wait_rxq(csk))
1638 			return;
1639 	}
1640 }
1641