xref: /linux/drivers/target/iscsi/cxgbit/cxgbit_target.c (revision 0883c2c06fb5bcf5b9e008270827e63c09a88c1e)
1 /*
2  * Copyright (c) 2016 Chelsio Communications, Inc.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  */
8 
9 #include <linux/workqueue.h>
10 #include <linux/kthread.h>
11 #include <asm/unaligned.h>
12 #include <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 #define MAX_IMM_TX_PKT_LEN	256
90 	return length <= MAX_IMM_TX_PKT_LEN;
91 }
92 
93 /*
94  * cxgbit_sgl_len - calculates the size of an SGL of the given capacity
95  * @n: the number of SGL entries
96  * Calculates the number of flits needed for a scatter/gather list that
97  * can hold the given number of entries.
98  */
99 static inline unsigned int cxgbit_sgl_len(unsigned int n)
100 {
101 	n--;
102 	return (3 * n) / 2 + (n & 1) + 2;
103 }
104 
105 /*
106  * cxgbit_calc_tx_flits_ofld - calculate # of flits for an offload packet
107  * @skb: the packet
108  *
109  * Returns the number of flits needed for the given offload packet.
110  * These packets are already fully constructed and no additional headers
111  * will be added.
112  */
113 static unsigned int cxgbit_calc_tx_flits_ofld(const struct sk_buff *skb)
114 {
115 	unsigned int flits, cnt;
116 
117 	if (cxgbit_is_ofld_imm(skb))
118 		return DIV_ROUND_UP(skb->len, 8);
119 	flits = skb_transport_offset(skb) / 8;
120 	cnt = skb_shinfo(skb)->nr_frags;
121 	if (skb_tail_pointer(skb) != skb_transport_header(skb))
122 		cnt++;
123 	return flits + cxgbit_sgl_len(cnt);
124 }
125 
126 #define CXGBIT_ISO_FSLICE 0x1
127 #define CXGBIT_ISO_LSLICE 0x2
128 static void
129 cxgbit_cpl_tx_data_iso(struct sk_buff *skb, struct cxgbit_iso_info *iso_info)
130 {
131 	struct cpl_tx_data_iso *cpl;
132 	unsigned int submode = cxgbit_skcb_submode(skb);
133 	unsigned int fslice = !!(iso_info->flags & CXGBIT_ISO_FSLICE);
134 	unsigned int lslice = !!(iso_info->flags & CXGBIT_ISO_LSLICE);
135 
136 	cpl = (struct cpl_tx_data_iso *)__skb_push(skb, sizeof(*cpl));
137 
138 	cpl->op_to_scsi = htonl(CPL_TX_DATA_ISO_OP_V(CPL_TX_DATA_ISO) |
139 			CPL_TX_DATA_ISO_FIRST_V(fslice) |
140 			CPL_TX_DATA_ISO_LAST_V(lslice) |
141 			CPL_TX_DATA_ISO_CPLHDRLEN_V(0) |
142 			CPL_TX_DATA_ISO_HDRCRC_V(submode & 1) |
143 			CPL_TX_DATA_ISO_PLDCRC_V(((submode >> 1) & 1)) |
144 			CPL_TX_DATA_ISO_IMMEDIATE_V(0) |
145 			CPL_TX_DATA_ISO_SCSI_V(2));
146 
147 	cpl->ahs_len = 0;
148 	cpl->mpdu = htons(DIV_ROUND_UP(iso_info->mpdu, 4));
149 	cpl->burst_size = htonl(DIV_ROUND_UP(iso_info->burst_len, 4));
150 	cpl->len = htonl(iso_info->len);
151 	cpl->reserved2_seglen_offset = htonl(0);
152 	cpl->datasn_offset = htonl(0);
153 	cpl->buffer_offset = htonl(0);
154 	cpl->reserved3 = 0;
155 
156 	__skb_pull(skb, sizeof(*cpl));
157 }
158 
159 static void
160 cxgbit_tx_data_wr(struct cxgbit_sock *csk, struct sk_buff *skb, u32 dlen,
161 		  u32 len, u32 credits, u32 compl)
162 {
163 	struct fw_ofld_tx_data_wr *req;
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 = TX_FORCE_V(!submode);
170 
171 	if (cxgbit_skcb_flags(skb) & SKCBF_TX_ISO) {
172 		opcode = FW_ISCSI_TX_DATA_WR;
173 		immlen += sizeof(struct cpl_tx_data_iso);
174 		hdr_size += sizeof(struct cpl_tx_data_iso);
175 		submode |= 8;
176 	}
177 
178 	if (cxgbit_is_ofld_imm(skb))
179 		immlen += dlen;
180 
181 	req = (struct fw_ofld_tx_data_wr *)__skb_push(skb,
182 							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 = 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 bool cxgbit_lock_sock(struct cxgbit_sock *csk)
287 {
288 	spin_lock_bh(&csk->lock);
289 
290 	if (before(csk->write_seq, csk->snd_una + csk->snd_win))
291 		csk->lock_owner = true;
292 
293 	spin_unlock_bh(&csk->lock);
294 
295 	return csk->lock_owner;
296 }
297 
298 static void cxgbit_unlock_sock(struct cxgbit_sock *csk)
299 {
300 	struct sk_buff_head backlogq;
301 	struct sk_buff *skb;
302 	void (*fn)(struct cxgbit_sock *, struct sk_buff *);
303 
304 	skb_queue_head_init(&backlogq);
305 
306 	spin_lock_bh(&csk->lock);
307 	while (skb_queue_len(&csk->backlogq)) {
308 		skb_queue_splice_init(&csk->backlogq, &backlogq);
309 		spin_unlock_bh(&csk->lock);
310 
311 		while ((skb = __skb_dequeue(&backlogq))) {
312 			fn = cxgbit_skcb_rx_backlog_fn(skb);
313 			fn(csk, skb);
314 		}
315 
316 		spin_lock_bh(&csk->lock);
317 	}
318 
319 	csk->lock_owner = false;
320 	spin_unlock_bh(&csk->lock);
321 }
322 
323 static int cxgbit_queue_skb(struct cxgbit_sock *csk, struct sk_buff *skb)
324 {
325 	int ret = 0;
326 
327 	wait_event_interruptible(csk->ack_waitq, cxgbit_lock_sock(csk));
328 
329 	if (unlikely((csk->com.state != CSK_STATE_ESTABLISHED) ||
330 		     signal_pending(current))) {
331 		__kfree_skb(skb);
332 		__skb_queue_purge(&csk->ppodq);
333 		ret = -1;
334 		spin_lock_bh(&csk->lock);
335 		if (csk->lock_owner) {
336 			spin_unlock_bh(&csk->lock);
337 			goto unlock;
338 		}
339 		spin_unlock_bh(&csk->lock);
340 		return ret;
341 	}
342 
343 	csk->write_seq += skb->len +
344 			  cxgbit_skcb_tx_extralen(skb);
345 
346 	skb_queue_splice_tail_init(&csk->ppodq, &csk->txq);
347 	__skb_queue_tail(&csk->txq, skb);
348 	cxgbit_push_tx_frames(csk);
349 
350 unlock:
351 	cxgbit_unlock_sock(csk);
352 	return ret;
353 }
354 
355 static int
356 cxgbit_map_skb(struct iscsi_cmd *cmd, struct sk_buff *skb, u32 data_offset,
357 	       u32 data_length)
358 {
359 	u32 i = 0, nr_frags = MAX_SKB_FRAGS;
360 	u32 padding = ((-data_length) & 3);
361 	struct scatterlist *sg;
362 	struct page *page;
363 	unsigned int page_off;
364 
365 	if (padding)
366 		nr_frags--;
367 
368 	/*
369 	 * We know each entry in t_data_sg contains a page.
370 	 */
371 	sg = &cmd->se_cmd.t_data_sg[data_offset / PAGE_SIZE];
372 	page_off = (data_offset % PAGE_SIZE);
373 
374 	while (data_length && (i < nr_frags)) {
375 		u32 cur_len = min_t(u32, data_length, sg->length - page_off);
376 
377 		page = sg_page(sg);
378 
379 		get_page(page);
380 		skb_fill_page_desc(skb, i, page, sg->offset + page_off,
381 				   cur_len);
382 		skb->data_len += cur_len;
383 		skb->len += cur_len;
384 		skb->truesize += cur_len;
385 
386 		data_length -= cur_len;
387 		page_off = 0;
388 		sg = sg_next(sg);
389 		i++;
390 	}
391 
392 	if (data_length)
393 		return -1;
394 
395 	if (padding) {
396 		page = alloc_page(GFP_KERNEL | __GFP_ZERO);
397 		if (!page)
398 			return -1;
399 		skb_fill_page_desc(skb, i, page, 0, padding);
400 		skb->data_len += padding;
401 		skb->len += padding;
402 		skb->truesize += padding;
403 	}
404 
405 	return 0;
406 }
407 
408 static int
409 cxgbit_tx_datain_iso(struct cxgbit_sock *csk, struct iscsi_cmd *cmd,
410 		     struct iscsi_datain_req *dr)
411 {
412 	struct iscsi_conn *conn = csk->conn;
413 	struct sk_buff *skb;
414 	struct iscsi_datain datain;
415 	struct cxgbit_iso_info iso_info;
416 	u32 data_length = cmd->se_cmd.data_length;
417 	u32 mrdsl = conn->conn_ops->MaxRecvDataSegmentLength;
418 	u32 num_pdu, plen, tx_data = 0;
419 	bool task_sense = !!(cmd->se_cmd.se_cmd_flags &
420 		SCF_TRANSPORT_TASK_SENSE);
421 	bool set_statsn = false;
422 	int ret = -1;
423 
424 	while (data_length) {
425 		num_pdu = (data_length + mrdsl - 1) / mrdsl;
426 		if (num_pdu > csk->max_iso_npdu)
427 			num_pdu = csk->max_iso_npdu;
428 
429 		plen = num_pdu * mrdsl;
430 		if (plen > data_length)
431 			plen = data_length;
432 
433 		skb = __cxgbit_alloc_skb(csk, 0, true);
434 		if (unlikely(!skb))
435 			return -ENOMEM;
436 
437 		memset(skb->data, 0, ISCSI_HDR_LEN);
438 		cxgbit_skcb_flags(skb) |= SKCBF_TX_ISO;
439 		cxgbit_skcb_submode(skb) |= (csk->submode &
440 				CXGBIT_SUBMODE_DCRC);
441 		cxgbit_skcb_tx_extralen(skb) = (num_pdu *
442 				cxgbit_digest_len[cxgbit_skcb_submode(skb)]) +
443 						((num_pdu - 1) * ISCSI_HDR_LEN);
444 
445 		memset(&datain, 0, sizeof(struct iscsi_datain));
446 		memset(&iso_info, 0, sizeof(iso_info));
447 
448 		if (!tx_data)
449 			iso_info.flags |= CXGBIT_ISO_FSLICE;
450 
451 		if (!(data_length - plen)) {
452 			iso_info.flags |= CXGBIT_ISO_LSLICE;
453 			if (!task_sense) {
454 				datain.flags = ISCSI_FLAG_DATA_STATUS;
455 				iscsit_increment_maxcmdsn(cmd, conn->sess);
456 				cmd->stat_sn = conn->stat_sn++;
457 				set_statsn = true;
458 			}
459 		}
460 
461 		iso_info.burst_len = num_pdu * mrdsl;
462 		iso_info.mpdu = mrdsl;
463 		iso_info.len = ISCSI_HDR_LEN + plen;
464 
465 		cxgbit_cpl_tx_data_iso(skb, &iso_info);
466 
467 		datain.offset = tx_data;
468 		datain.data_sn = cmd->data_sn - 1;
469 
470 		iscsit_build_datain_pdu(cmd, conn, &datain,
471 					(struct iscsi_data_rsp *)skb->data,
472 					set_statsn);
473 
474 		ret = cxgbit_map_skb(cmd, skb, tx_data, plen);
475 		if (unlikely(ret)) {
476 			__kfree_skb(skb);
477 			goto out;
478 		}
479 
480 		ret = cxgbit_queue_skb(csk, skb);
481 		if (unlikely(ret))
482 			goto out;
483 
484 		tx_data += plen;
485 		data_length -= plen;
486 
487 		cmd->read_data_done += plen;
488 		cmd->data_sn += num_pdu;
489 	}
490 
491 	dr->dr_complete = DATAIN_COMPLETE_NORMAL;
492 
493 	return 0;
494 
495 out:
496 	return ret;
497 }
498 
499 static int
500 cxgbit_tx_datain(struct cxgbit_sock *csk, struct iscsi_cmd *cmd,
501 		 const struct iscsi_datain *datain)
502 {
503 	struct sk_buff *skb;
504 	int ret = 0;
505 
506 	skb = cxgbit_alloc_skb(csk, 0);
507 	if (unlikely(!skb))
508 		return -ENOMEM;
509 
510 	memcpy(skb->data, cmd->pdu, ISCSI_HDR_LEN);
511 
512 	if (datain->length) {
513 		cxgbit_skcb_submode(skb) |= (csk->submode &
514 				CXGBIT_SUBMODE_DCRC);
515 		cxgbit_skcb_tx_extralen(skb) =
516 				cxgbit_digest_len[cxgbit_skcb_submode(skb)];
517 	}
518 
519 	ret = cxgbit_map_skb(cmd, skb, datain->offset, datain->length);
520 	if (ret < 0) {
521 		__kfree_skb(skb);
522 		return ret;
523 	}
524 
525 	return cxgbit_queue_skb(csk, skb);
526 }
527 
528 static int
529 cxgbit_xmit_datain_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
530 		       struct iscsi_datain_req *dr,
531 		       const struct iscsi_datain *datain)
532 {
533 	struct cxgbit_sock *csk = conn->context;
534 	u32 data_length = cmd->se_cmd.data_length;
535 	u32 padding = ((-data_length) & 3);
536 	u32 mrdsl = conn->conn_ops->MaxRecvDataSegmentLength;
537 
538 	if ((data_length > mrdsl) && (!dr->recovery) &&
539 	    (!padding) && (!datain->offset) && csk->max_iso_npdu) {
540 		atomic_long_add(data_length - datain->length,
541 				&conn->sess->tx_data_octets);
542 		return cxgbit_tx_datain_iso(csk, cmd, dr);
543 	}
544 
545 	return cxgbit_tx_datain(csk, cmd, datain);
546 }
547 
548 static int
549 cxgbit_xmit_nondatain_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
550 			  const void *data_buf, u32 data_buf_len)
551 {
552 	struct cxgbit_sock *csk = conn->context;
553 	struct sk_buff *skb;
554 	u32 padding = ((-data_buf_len) & 3);
555 
556 	skb = cxgbit_alloc_skb(csk, data_buf_len + padding);
557 	if (unlikely(!skb))
558 		return -ENOMEM;
559 
560 	memcpy(skb->data, cmd->pdu, ISCSI_HDR_LEN);
561 
562 	if (data_buf_len) {
563 		u32 pad_bytes = 0;
564 
565 		skb_store_bits(skb, ISCSI_HDR_LEN, data_buf, data_buf_len);
566 
567 		if (padding)
568 			skb_store_bits(skb, ISCSI_HDR_LEN + data_buf_len,
569 				       &pad_bytes, padding);
570 	}
571 
572 	cxgbit_skcb_tx_extralen(skb) = cxgbit_digest_len[
573 				       cxgbit_skcb_submode(skb)];
574 
575 	return cxgbit_queue_skb(csk, skb);
576 }
577 
578 int
579 cxgbit_xmit_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
580 		struct iscsi_datain_req *dr, const void *buf, u32 buf_len)
581 {
582 	if (dr)
583 		return cxgbit_xmit_datain_pdu(conn, cmd, dr, buf);
584 	else
585 		return cxgbit_xmit_nondatain_pdu(conn, cmd, buf, buf_len);
586 }
587 
588 int cxgbit_validate_params(struct iscsi_conn *conn)
589 {
590 	struct cxgbit_sock *csk = conn->context;
591 	struct cxgbit_device *cdev = csk->com.cdev;
592 	struct iscsi_param *param;
593 	u32 max_xmitdsl;
594 
595 	param = iscsi_find_param_from_key(MAXXMITDATASEGMENTLENGTH,
596 					  conn->param_list);
597 	if (!param)
598 		return -1;
599 
600 	if (kstrtou32(param->value, 0, &max_xmitdsl) < 0)
601 		return -1;
602 
603 	if (max_xmitdsl > cdev->mdsl) {
604 		if (iscsi_change_param_sprintf(
605 			conn, "MaxXmitDataSegmentLength=%u", cdev->mdsl))
606 			return -1;
607 	}
608 
609 	return 0;
610 }
611 
612 static int cxgbit_set_digest(struct cxgbit_sock *csk)
613 {
614 	struct iscsi_conn *conn = csk->conn;
615 	struct iscsi_param *param;
616 
617 	param = iscsi_find_param_from_key(HEADERDIGEST, conn->param_list);
618 	if (!param) {
619 		pr_err("param not found key %s\n", HEADERDIGEST);
620 		return -1;
621 	}
622 
623 	if (!strcmp(param->value, CRC32C))
624 		csk->submode |= CXGBIT_SUBMODE_HCRC;
625 
626 	param = iscsi_find_param_from_key(DATADIGEST, conn->param_list);
627 	if (!param) {
628 		csk->submode = 0;
629 		pr_err("param not found key %s\n", DATADIGEST);
630 		return -1;
631 	}
632 
633 	if (!strcmp(param->value, CRC32C))
634 		csk->submode |= CXGBIT_SUBMODE_DCRC;
635 
636 	if (cxgbit_setup_conn_digest(csk)) {
637 		csk->submode = 0;
638 		return -1;
639 	}
640 
641 	return 0;
642 }
643 
644 static int cxgbit_set_iso_npdu(struct cxgbit_sock *csk)
645 {
646 	struct iscsi_conn *conn = csk->conn;
647 	struct iscsi_conn_ops *conn_ops = conn->conn_ops;
648 	struct iscsi_param *param;
649 	u32 mrdsl, mbl;
650 	u32 max_npdu, max_iso_npdu;
651 
652 	if (conn->login->leading_connection) {
653 		param = iscsi_find_param_from_key(DATASEQUENCEINORDER,
654 						  conn->param_list);
655 		if (!param) {
656 			pr_err("param not found key %s\n", DATASEQUENCEINORDER);
657 			return -1;
658 		}
659 
660 		if (strcmp(param->value, YES))
661 			return 0;
662 
663 		param = iscsi_find_param_from_key(DATAPDUINORDER,
664 						  conn->param_list);
665 		if (!param) {
666 			pr_err("param not found key %s\n", DATAPDUINORDER);
667 			return -1;
668 		}
669 
670 		if (strcmp(param->value, YES))
671 			return 0;
672 
673 		param = iscsi_find_param_from_key(MAXBURSTLENGTH,
674 						  conn->param_list);
675 		if (!param) {
676 			pr_err("param not found key %s\n", MAXBURSTLENGTH);
677 			return -1;
678 		}
679 
680 		if (kstrtou32(param->value, 0, &mbl) < 0)
681 			return -1;
682 	} else {
683 		if (!conn->sess->sess_ops->DataSequenceInOrder)
684 			return 0;
685 		if (!conn->sess->sess_ops->DataPDUInOrder)
686 			return 0;
687 
688 		mbl = conn->sess->sess_ops->MaxBurstLength;
689 	}
690 
691 	mrdsl = conn_ops->MaxRecvDataSegmentLength;
692 	max_npdu = mbl / mrdsl;
693 
694 	max_iso_npdu = CXGBIT_MAX_ISO_PAYLOAD /
695 			(ISCSI_HDR_LEN + mrdsl +
696 			cxgbit_digest_len[csk->submode]);
697 
698 	csk->max_iso_npdu = min(max_npdu, max_iso_npdu);
699 
700 	if (csk->max_iso_npdu <= 1)
701 		csk->max_iso_npdu = 0;
702 
703 	return 0;
704 }
705 
706 static int cxgbit_set_params(struct iscsi_conn *conn)
707 {
708 	struct cxgbit_sock *csk = conn->context;
709 	struct cxgbit_device *cdev = csk->com.cdev;
710 	struct cxgbi_ppm *ppm = *csk->com.cdev->lldi.iscsi_ppm;
711 	struct iscsi_conn_ops *conn_ops = conn->conn_ops;
712 	struct iscsi_param *param;
713 	u8 erl;
714 
715 	if (conn_ops->MaxRecvDataSegmentLength > cdev->mdsl)
716 		conn_ops->MaxRecvDataSegmentLength = cdev->mdsl;
717 
718 	if (conn->login->leading_connection) {
719 		param = iscsi_find_param_from_key(ERRORRECOVERYLEVEL,
720 						  conn->param_list);
721 		if (!param) {
722 			pr_err("param not found key %s\n", ERRORRECOVERYLEVEL);
723 			return -1;
724 		}
725 		if (kstrtou8(param->value, 0, &erl) < 0)
726 			return -1;
727 	} else {
728 		erl = conn->sess->sess_ops->ErrorRecoveryLevel;
729 	}
730 
731 	if (!erl) {
732 		if (test_bit(CDEV_ISO_ENABLE, &cdev->flags)) {
733 			if (cxgbit_set_iso_npdu(csk))
734 				return -1;
735 		}
736 
737 		if (test_bit(CDEV_DDP_ENABLE, &cdev->flags)) {
738 			if (cxgbit_setup_conn_pgidx(csk,
739 						    ppm->tformat.pgsz_idx_dflt))
740 				return -1;
741 			set_bit(CSK_DDP_ENABLE, &csk->com.flags);
742 		}
743 	}
744 
745 	if (cxgbit_set_digest(csk))
746 		return -1;
747 
748 	return 0;
749 }
750 
751 int
752 cxgbit_put_login_tx(struct iscsi_conn *conn, struct iscsi_login *login,
753 		    u32 length)
754 {
755 	struct cxgbit_sock *csk = conn->context;
756 	struct sk_buff *skb;
757 	u32 padding_buf = 0;
758 	u8 padding = ((-length) & 3);
759 
760 	skb = cxgbit_alloc_skb(csk, length + padding);
761 	if (!skb)
762 		return -ENOMEM;
763 	skb_store_bits(skb, 0, login->rsp, ISCSI_HDR_LEN);
764 	skb_store_bits(skb, ISCSI_HDR_LEN, login->rsp_buf, length);
765 
766 	if (padding)
767 		skb_store_bits(skb, ISCSI_HDR_LEN + length,
768 			       &padding_buf, padding);
769 
770 	if (login->login_complete) {
771 		if (cxgbit_set_params(conn)) {
772 			kfree_skb(skb);
773 			return -1;
774 		}
775 
776 		set_bit(CSK_LOGIN_DONE, &csk->com.flags);
777 	}
778 
779 	if (cxgbit_queue_skb(csk, skb))
780 		return -1;
781 
782 	if ((!login->login_complete) && (!login->login_failed))
783 		schedule_delayed_work(&conn->login_work, 0);
784 
785 	return 0;
786 }
787 
788 static void
789 cxgbit_skb_copy_to_sg(struct sk_buff *skb, struct scatterlist *sg,
790 		      unsigned int nents)
791 {
792 	struct skb_seq_state st;
793 	const u8 *buf;
794 	unsigned int consumed = 0, buf_len;
795 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(skb);
796 
797 	skb_prepare_seq_read(skb, pdu_cb->doffset,
798 			     pdu_cb->doffset + pdu_cb->dlen,
799 			     &st);
800 
801 	while (true) {
802 		buf_len = skb_seq_read(consumed, &buf, &st);
803 		if (!buf_len) {
804 			skb_abort_seq_read(&st);
805 			break;
806 		}
807 
808 		consumed += sg_pcopy_from_buffer(sg, nents, (void *)buf,
809 						 buf_len, consumed);
810 	}
811 }
812 
813 static struct iscsi_cmd *cxgbit_allocate_cmd(struct cxgbit_sock *csk)
814 {
815 	struct iscsi_conn *conn = csk->conn;
816 	struct cxgbi_ppm *ppm = cdev2ppm(csk->com.cdev);
817 	struct cxgbit_cmd *ccmd;
818 	struct iscsi_cmd *cmd;
819 
820 	cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
821 	if (!cmd) {
822 		pr_err("Unable to allocate iscsi_cmd + cxgbit_cmd\n");
823 		return NULL;
824 	}
825 
826 	ccmd = iscsit_priv_cmd(cmd);
827 	ccmd->ttinfo.tag = ppm->tformat.no_ddp_mask;
828 	ccmd->setup_ddp = true;
829 
830 	return cmd;
831 }
832 
833 static int
834 cxgbit_handle_immediate_data(struct iscsi_cmd *cmd, struct iscsi_scsi_req *hdr,
835 			     u32 length)
836 {
837 	struct iscsi_conn *conn = cmd->conn;
838 	struct cxgbit_sock *csk = conn->context;
839 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
840 
841 	if (pdu_cb->flags & PDUCBF_RX_DCRC_ERR) {
842 		pr_err("ImmediateData CRC32C DataDigest error\n");
843 		if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
844 			pr_err("Unable to recover from"
845 			       " Immediate Data digest failure while"
846 			       " in ERL=0.\n");
847 			iscsit_reject_cmd(cmd, ISCSI_REASON_DATA_DIGEST_ERROR,
848 					  (unsigned char *)hdr);
849 			return IMMEDIATE_DATA_CANNOT_RECOVER;
850 		}
851 
852 		iscsit_reject_cmd(cmd, ISCSI_REASON_DATA_DIGEST_ERROR,
853 				  (unsigned char *)hdr);
854 		return IMMEDIATE_DATA_ERL1_CRC_FAILURE;
855 	}
856 
857 	if (cmd->se_cmd.se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
858 		struct cxgbit_cmd *ccmd = iscsit_priv_cmd(cmd);
859 		struct skb_shared_info *ssi = skb_shinfo(csk->skb);
860 		skb_frag_t *dfrag = &ssi->frags[pdu_cb->dfrag_idx];
861 
862 		sg_init_table(&ccmd->sg, 1);
863 		sg_set_page(&ccmd->sg, dfrag->page.p, skb_frag_size(dfrag),
864 			    dfrag->page_offset);
865 		get_page(dfrag->page.p);
866 
867 		cmd->se_cmd.t_data_sg = &ccmd->sg;
868 		cmd->se_cmd.t_data_nents = 1;
869 
870 		ccmd->release = true;
871 	} else {
872 		struct scatterlist *sg = &cmd->se_cmd.t_data_sg[0];
873 		u32 sg_nents = max(1UL, DIV_ROUND_UP(pdu_cb->dlen, PAGE_SIZE));
874 
875 		cxgbit_skb_copy_to_sg(csk->skb, sg, sg_nents);
876 	}
877 
878 	cmd->write_data_done += pdu_cb->dlen;
879 
880 	if (cmd->write_data_done == cmd->se_cmd.data_length) {
881 		spin_lock_bh(&cmd->istate_lock);
882 		cmd->cmd_flags |= ICF_GOT_LAST_DATAOUT;
883 		cmd->i_state = ISTATE_RECEIVED_LAST_DATAOUT;
884 		spin_unlock_bh(&cmd->istate_lock);
885 	}
886 
887 	return IMMEDIATE_DATA_NORMAL_OPERATION;
888 }
889 
890 static int
891 cxgbit_get_immediate_data(struct iscsi_cmd *cmd, struct iscsi_scsi_req *hdr,
892 			  bool dump_payload)
893 {
894 	struct iscsi_conn *conn = cmd->conn;
895 	int cmdsn_ret = 0, immed_ret = IMMEDIATE_DATA_NORMAL_OPERATION;
896 	/*
897 	 * Special case for Unsupported SAM WRITE Opcodes and ImmediateData=Yes.
898 	 */
899 	if (dump_payload)
900 		goto after_immediate_data;
901 
902 	immed_ret = cxgbit_handle_immediate_data(cmd, hdr,
903 						 cmd->first_burst_len);
904 after_immediate_data:
905 	if (immed_ret == IMMEDIATE_DATA_NORMAL_OPERATION) {
906 		/*
907 		 * A PDU/CmdSN carrying Immediate Data passed
908 		 * DataCRC, check against ExpCmdSN/MaxCmdSN if
909 		 * Immediate Bit is not set.
910 		 */
911 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd,
912 						(unsigned char *)hdr,
913 						hdr->cmdsn);
914 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
915 			return -1;
916 
917 		if (cmd->sense_reason || cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
918 			target_put_sess_cmd(&cmd->se_cmd);
919 			return 0;
920 		} else if (cmd->unsolicited_data) {
921 			iscsit_set_unsoliticed_dataout(cmd);
922 		}
923 
924 	} else if (immed_ret == IMMEDIATE_DATA_ERL1_CRC_FAILURE) {
925 		/*
926 		 * Immediate Data failed DataCRC and ERL>=1,
927 		 * silently drop this PDU and let the initiator
928 		 * plug the CmdSN gap.
929 		 *
930 		 * FIXME: Send Unsolicited NOPIN with reserved
931 		 * TTT here to help the initiator figure out
932 		 * the missing CmdSN, although they should be
933 		 * intelligent enough to determine the missing
934 		 * CmdSN and issue a retry to plug the sequence.
935 		 */
936 		cmd->i_state = ISTATE_REMOVE;
937 		iscsit_add_cmd_to_immediate_queue(cmd, conn, cmd->i_state);
938 	} else /* immed_ret == IMMEDIATE_DATA_CANNOT_RECOVER */
939 		return -1;
940 
941 	return 0;
942 }
943 
944 static int
945 cxgbit_handle_scsi_cmd(struct cxgbit_sock *csk, struct iscsi_cmd *cmd)
946 {
947 	struct iscsi_conn *conn = csk->conn;
948 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
949 	struct iscsi_scsi_req *hdr = (struct iscsi_scsi_req *)pdu_cb->hdr;
950 	int rc;
951 	bool dump_payload = false;
952 
953 	rc = iscsit_setup_scsi_cmd(conn, cmd, (unsigned char *)hdr);
954 	if (rc < 0)
955 		return rc;
956 
957 	if (pdu_cb->dlen && (pdu_cb->dlen == cmd->se_cmd.data_length) &&
958 	    (pdu_cb->nr_dfrags == 1))
959 		cmd->se_cmd.se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
960 
961 	rc = iscsit_process_scsi_cmd(conn, cmd, hdr);
962 	if (rc < 0)
963 		return 0;
964 	else if (rc > 0)
965 		dump_payload = true;
966 
967 	if (!pdu_cb->dlen)
968 		return 0;
969 
970 	return cxgbit_get_immediate_data(cmd, hdr, dump_payload);
971 }
972 
973 static int cxgbit_handle_iscsi_dataout(struct cxgbit_sock *csk)
974 {
975 	struct scatterlist *sg_start;
976 	struct iscsi_conn *conn = csk->conn;
977 	struct iscsi_cmd *cmd = NULL;
978 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
979 	struct iscsi_data *hdr = (struct iscsi_data *)pdu_cb->hdr;
980 	u32 data_offset = be32_to_cpu(hdr->offset);
981 	u32 data_len = pdu_cb->dlen;
982 	int rc, sg_nents, sg_off;
983 	bool dcrc_err = false;
984 
985 	rc = iscsit_check_dataout_hdr(conn, (unsigned char *)hdr, &cmd);
986 	if (rc < 0)
987 		return rc;
988 	else if (!cmd)
989 		return 0;
990 
991 	if (pdu_cb->flags & PDUCBF_RX_DCRC_ERR) {
992 		pr_err("ITT: 0x%08x, Offset: %u, Length: %u,"
993 		       " DataSN: 0x%08x\n",
994 		       hdr->itt, hdr->offset, data_len,
995 		       hdr->datasn);
996 
997 		dcrc_err = true;
998 		goto check_payload;
999 	}
1000 
1001 	pr_debug("DataOut data_len: %u, "
1002 		"write_data_done: %u, data_length: %u\n",
1003 		  data_len,  cmd->write_data_done,
1004 		  cmd->se_cmd.data_length);
1005 
1006 	if (!(pdu_cb->flags & PDUCBF_RX_DATA_DDPD)) {
1007 		sg_off = data_offset / PAGE_SIZE;
1008 		sg_start = &cmd->se_cmd.t_data_sg[sg_off];
1009 		sg_nents = max(1UL, DIV_ROUND_UP(data_len, PAGE_SIZE));
1010 
1011 		cxgbit_skb_copy_to_sg(csk->skb, sg_start, sg_nents);
1012 	}
1013 
1014 check_payload:
1015 
1016 	rc = iscsit_check_dataout_payload(cmd, hdr, dcrc_err);
1017 	if (rc < 0)
1018 		return rc;
1019 
1020 	return 0;
1021 }
1022 
1023 static int cxgbit_handle_nop_out(struct cxgbit_sock *csk, struct iscsi_cmd *cmd)
1024 {
1025 	struct iscsi_conn *conn = csk->conn;
1026 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
1027 	struct iscsi_nopout *hdr = (struct iscsi_nopout *)pdu_cb->hdr;
1028 	unsigned char *ping_data = NULL;
1029 	u32 payload_length = pdu_cb->dlen;
1030 	int ret;
1031 
1032 	ret = iscsit_setup_nop_out(conn, cmd, hdr);
1033 	if (ret < 0)
1034 		return 0;
1035 
1036 	if (pdu_cb->flags & PDUCBF_RX_DCRC_ERR) {
1037 		if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
1038 			pr_err("Unable to recover from"
1039 			       " NOPOUT Ping DataCRC failure while in"
1040 			       " ERL=0.\n");
1041 			ret = -1;
1042 			goto out;
1043 		} else {
1044 			/*
1045 			 * drop this PDU and let the
1046 			 * initiator plug the CmdSN gap.
1047 			 */
1048 			pr_info("Dropping NOPOUT"
1049 				" Command CmdSN: 0x%08x due to"
1050 				" DataCRC error.\n", hdr->cmdsn);
1051 			ret = 0;
1052 			goto out;
1053 		}
1054 	}
1055 
1056 	/*
1057 	 * Handle NOP-OUT payload for traditional iSCSI sockets
1058 	 */
1059 	if (payload_length && hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
1060 		ping_data = kzalloc(payload_length + 1, GFP_KERNEL);
1061 		if (!ping_data) {
1062 			pr_err("Unable to allocate memory for"
1063 				" NOPOUT ping data.\n");
1064 			ret = -1;
1065 			goto out;
1066 		}
1067 
1068 		skb_copy_bits(csk->skb, pdu_cb->doffset,
1069 			      ping_data, payload_length);
1070 
1071 		ping_data[payload_length] = '\0';
1072 		/*
1073 		 * Attach ping data to struct iscsi_cmd->buf_ptr.
1074 		 */
1075 		cmd->buf_ptr = ping_data;
1076 		cmd->buf_ptr_size = payload_length;
1077 
1078 		pr_debug("Got %u bytes of NOPOUT ping"
1079 			" data.\n", payload_length);
1080 		pr_debug("Ping Data: \"%s\"\n", ping_data);
1081 	}
1082 
1083 	return iscsit_process_nop_out(conn, cmd, hdr);
1084 out:
1085 	if (cmd)
1086 		iscsit_free_cmd(cmd, false);
1087 	return ret;
1088 }
1089 
1090 static int
1091 cxgbit_handle_text_cmd(struct cxgbit_sock *csk, struct iscsi_cmd *cmd)
1092 {
1093 	struct iscsi_conn *conn = csk->conn;
1094 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
1095 	struct iscsi_text *hdr = (struct iscsi_text *)pdu_cb->hdr;
1096 	u32 payload_length = pdu_cb->dlen;
1097 	int rc;
1098 	unsigned char *text_in = NULL;
1099 
1100 	rc = iscsit_setup_text_cmd(conn, cmd, hdr);
1101 	if (rc < 0)
1102 		return rc;
1103 
1104 	if (pdu_cb->flags & PDUCBF_RX_DCRC_ERR) {
1105 		if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
1106 			pr_err("Unable to recover from"
1107 			       " Text Data digest failure while in"
1108 			       " ERL=0.\n");
1109 			goto reject;
1110 		} else {
1111 			/*
1112 			 * drop this PDU and let the
1113 			 * initiator plug the CmdSN gap.
1114 			 */
1115 			pr_info("Dropping Text"
1116 				" Command CmdSN: 0x%08x due to"
1117 				" DataCRC error.\n", hdr->cmdsn);
1118 			return 0;
1119 		}
1120 	}
1121 
1122 	if (payload_length) {
1123 		text_in = kzalloc(payload_length, GFP_KERNEL);
1124 		if (!text_in) {
1125 			pr_err("Unable to allocate text_in of payload_length: %u\n",
1126 			       payload_length);
1127 			return -ENOMEM;
1128 		}
1129 		skb_copy_bits(csk->skb, pdu_cb->doffset,
1130 			      text_in, payload_length);
1131 
1132 		text_in[payload_length - 1] = '\0';
1133 
1134 		cmd->text_in_ptr = text_in;
1135 	}
1136 
1137 	return iscsit_process_text_cmd(conn, cmd, hdr);
1138 
1139 reject:
1140 	return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
1141 				 pdu_cb->hdr);
1142 }
1143 
1144 static int cxgbit_target_rx_opcode(struct cxgbit_sock *csk)
1145 {
1146 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
1147 	struct iscsi_hdr *hdr = (struct iscsi_hdr *)pdu_cb->hdr;
1148 	struct iscsi_conn *conn = csk->conn;
1149 	struct iscsi_cmd *cmd = NULL;
1150 	u8 opcode = (hdr->opcode & ISCSI_OPCODE_MASK);
1151 	int ret = -EINVAL;
1152 
1153 	switch (opcode) {
1154 	case ISCSI_OP_SCSI_CMD:
1155 		cmd = cxgbit_allocate_cmd(csk);
1156 		if (!cmd)
1157 			goto reject;
1158 
1159 		ret = cxgbit_handle_scsi_cmd(csk, cmd);
1160 		break;
1161 	case ISCSI_OP_SCSI_DATA_OUT:
1162 		ret = cxgbit_handle_iscsi_dataout(csk);
1163 		break;
1164 	case ISCSI_OP_NOOP_OUT:
1165 		if (hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
1166 			cmd = cxgbit_allocate_cmd(csk);
1167 			if (!cmd)
1168 				goto reject;
1169 		}
1170 
1171 		ret = cxgbit_handle_nop_out(csk, cmd);
1172 		break;
1173 	case ISCSI_OP_SCSI_TMFUNC:
1174 		cmd = cxgbit_allocate_cmd(csk);
1175 		if (!cmd)
1176 			goto reject;
1177 
1178 		ret = iscsit_handle_task_mgt_cmd(conn, cmd,
1179 						 (unsigned char *)hdr);
1180 		break;
1181 	case ISCSI_OP_TEXT:
1182 		if (hdr->ttt != cpu_to_be32(0xFFFFFFFF)) {
1183 			cmd = iscsit_find_cmd_from_itt(conn, hdr->itt);
1184 			if (!cmd)
1185 				goto reject;
1186 		} else {
1187 			cmd = cxgbit_allocate_cmd(csk);
1188 			if (!cmd)
1189 				goto reject;
1190 		}
1191 
1192 		ret = cxgbit_handle_text_cmd(csk, cmd);
1193 		break;
1194 	case ISCSI_OP_LOGOUT:
1195 		cmd = cxgbit_allocate_cmd(csk);
1196 		if (!cmd)
1197 			goto reject;
1198 
1199 		ret = iscsit_handle_logout_cmd(conn, cmd, (unsigned char *)hdr);
1200 		if (ret > 0)
1201 			wait_for_completion_timeout(&conn->conn_logout_comp,
1202 						    SECONDS_FOR_LOGOUT_COMP
1203 						    * HZ);
1204 		break;
1205 	case ISCSI_OP_SNACK:
1206 		ret = iscsit_handle_snack(conn, (unsigned char *)hdr);
1207 		break;
1208 	default:
1209 		pr_err("Got unknown iSCSI OpCode: 0x%02x\n", opcode);
1210 		dump_stack();
1211 		break;
1212 	}
1213 
1214 	return ret;
1215 
1216 reject:
1217 	return iscsit_add_reject(conn, ISCSI_REASON_BOOKMARK_NO_RESOURCES,
1218 				 (unsigned char *)hdr);
1219 	return ret;
1220 }
1221 
1222 static int cxgbit_rx_opcode(struct cxgbit_sock *csk)
1223 {
1224 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
1225 	struct iscsi_conn *conn = csk->conn;
1226 	struct iscsi_hdr *hdr = pdu_cb->hdr;
1227 	u8 opcode;
1228 
1229 	if (pdu_cb->flags & PDUCBF_RX_HCRC_ERR) {
1230 		atomic_long_inc(&conn->sess->conn_digest_errors);
1231 		goto transport_err;
1232 	}
1233 
1234 	if (conn->conn_state == TARG_CONN_STATE_IN_LOGOUT)
1235 		goto transport_err;
1236 
1237 	opcode = hdr->opcode & ISCSI_OPCODE_MASK;
1238 
1239 	if (conn->sess->sess_ops->SessionType &&
1240 	    ((!(opcode & ISCSI_OP_TEXT)) ||
1241 	     (!(opcode & ISCSI_OP_LOGOUT)))) {
1242 		pr_err("Received illegal iSCSI Opcode: 0x%02x"
1243 			" while in Discovery Session, rejecting.\n", opcode);
1244 		iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1245 				  (unsigned char *)hdr);
1246 		goto transport_err;
1247 	}
1248 
1249 	if (cxgbit_target_rx_opcode(csk) < 0)
1250 		goto transport_err;
1251 
1252 	return 0;
1253 
1254 transport_err:
1255 	return -1;
1256 }
1257 
1258 static int cxgbit_rx_login_pdu(struct cxgbit_sock *csk)
1259 {
1260 	struct iscsi_conn *conn = csk->conn;
1261 	struct iscsi_login *login = conn->login;
1262 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
1263 	struct iscsi_login_req *login_req;
1264 
1265 	login_req = (struct iscsi_login_req *)login->req;
1266 	memcpy(login_req, pdu_cb->hdr, sizeof(*login_req));
1267 
1268 	pr_debug("Got Login Command, Flags 0x%02x, ITT: 0x%08x,"
1269 		" CmdSN: 0x%08x, ExpStatSN: 0x%08x, CID: %hu, Length: %u\n",
1270 		login_req->flags, login_req->itt, login_req->cmdsn,
1271 		login_req->exp_statsn, login_req->cid, pdu_cb->dlen);
1272 	/*
1273 	 * Setup the initial iscsi_login values from the leading
1274 	 * login request PDU.
1275 	 */
1276 	if (login->first_request) {
1277 		login_req = (struct iscsi_login_req *)login->req;
1278 		login->leading_connection = (!login_req->tsih) ? 1 : 0;
1279 		login->current_stage	= ISCSI_LOGIN_CURRENT_STAGE(
1280 				login_req->flags);
1281 		login->version_min	= login_req->min_version;
1282 		login->version_max	= login_req->max_version;
1283 		memcpy(login->isid, login_req->isid, 6);
1284 		login->cmd_sn		= be32_to_cpu(login_req->cmdsn);
1285 		login->init_task_tag	= login_req->itt;
1286 		login->initial_exp_statsn = be32_to_cpu(login_req->exp_statsn);
1287 		login->cid		= be16_to_cpu(login_req->cid);
1288 		login->tsih		= be16_to_cpu(login_req->tsih);
1289 	}
1290 
1291 	if (iscsi_target_check_login_request(conn, login) < 0)
1292 		return -1;
1293 
1294 	memset(login->req_buf, 0, MAX_KEY_VALUE_PAIRS);
1295 	skb_copy_bits(csk->skb, pdu_cb->doffset, login->req_buf, pdu_cb->dlen);
1296 
1297 	return 0;
1298 }
1299 
1300 static int
1301 cxgbit_process_iscsi_pdu(struct cxgbit_sock *csk, struct sk_buff *skb, int idx)
1302 {
1303 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_skb_lro_pdu_cb(skb, idx);
1304 	int ret;
1305 
1306 	cxgbit_rx_pdu_cb(skb) = pdu_cb;
1307 
1308 	csk->skb = skb;
1309 
1310 	if (!test_bit(CSK_LOGIN_DONE, &csk->com.flags)) {
1311 		ret = cxgbit_rx_login_pdu(csk);
1312 		set_bit(CSK_LOGIN_PDU_DONE, &csk->com.flags);
1313 	} else {
1314 		ret = cxgbit_rx_opcode(csk);
1315 	}
1316 
1317 	return ret;
1318 }
1319 
1320 static void cxgbit_lro_skb_dump(struct sk_buff *skb)
1321 {
1322 	struct skb_shared_info *ssi = skb_shinfo(skb);
1323 	struct cxgbit_lro_cb *lro_cb = cxgbit_skb_lro_cb(skb);
1324 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_skb_lro_pdu_cb(skb, 0);
1325 	u8 i;
1326 
1327 	pr_info("skb 0x%p, head 0x%p, 0x%p, len %u,%u, frags %u.\n",
1328 		skb, skb->head, skb->data, skb->len, skb->data_len,
1329 		ssi->nr_frags);
1330 	pr_info("skb 0x%p, lro_cb, csk 0x%p, pdu %u, %u.\n",
1331 		skb, lro_cb->csk, lro_cb->pdu_idx, lro_cb->pdu_totallen);
1332 
1333 	for (i = 0; i < lro_cb->pdu_idx; i++, pdu_cb++)
1334 		pr_info("skb 0x%p, pdu %d, %u, f 0x%x, seq 0x%x, dcrc 0x%x, "
1335 			"frags %u.\n",
1336 			skb, i, pdu_cb->pdulen, pdu_cb->flags, pdu_cb->seq,
1337 			pdu_cb->ddigest, pdu_cb->frags);
1338 	for (i = 0; i < ssi->nr_frags; i++)
1339 		pr_info("skb 0x%p, frag %d, off %u, sz %u.\n",
1340 			skb, i, ssi->frags[i].page_offset, ssi->frags[i].size);
1341 }
1342 
1343 static void cxgbit_lro_hskb_reset(struct cxgbit_sock *csk)
1344 {
1345 	struct sk_buff *skb = csk->lro_hskb;
1346 	struct skb_shared_info *ssi = skb_shinfo(skb);
1347 	u8 i;
1348 
1349 	memset(skb->data, 0, LRO_SKB_MIN_HEADROOM);
1350 	for (i = 0; i < ssi->nr_frags; i++)
1351 		put_page(skb_frag_page(&ssi->frags[i]));
1352 	ssi->nr_frags = 0;
1353 }
1354 
1355 static void
1356 cxgbit_lro_skb_merge(struct cxgbit_sock *csk, struct sk_buff *skb, u8 pdu_idx)
1357 {
1358 	struct sk_buff *hskb = csk->lro_hskb;
1359 	struct cxgbit_lro_pdu_cb *hpdu_cb = cxgbit_skb_lro_pdu_cb(hskb, 0);
1360 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_skb_lro_pdu_cb(skb, pdu_idx);
1361 	struct skb_shared_info *hssi = skb_shinfo(hskb);
1362 	struct skb_shared_info *ssi = skb_shinfo(skb);
1363 	unsigned int len = 0;
1364 
1365 	if (pdu_cb->flags & PDUCBF_RX_HDR) {
1366 		hpdu_cb->flags = pdu_cb->flags;
1367 		hpdu_cb->seq = pdu_cb->seq;
1368 		hpdu_cb->hdr = pdu_cb->hdr;
1369 		hpdu_cb->hlen = pdu_cb->hlen;
1370 
1371 		memcpy(&hssi->frags[0], &ssi->frags[pdu_cb->hfrag_idx],
1372 		       sizeof(skb_frag_t));
1373 
1374 		get_page(skb_frag_page(&hssi->frags[0]));
1375 		hssi->nr_frags = 1;
1376 		hpdu_cb->frags = 1;
1377 		hpdu_cb->hfrag_idx = 0;
1378 
1379 		len = hssi->frags[0].size;
1380 		hskb->len = len;
1381 		hskb->data_len = len;
1382 		hskb->truesize = len;
1383 	}
1384 
1385 	if (pdu_cb->flags & PDUCBF_RX_DATA) {
1386 		u8 hfrag_idx = 1, i;
1387 
1388 		hpdu_cb->flags |= pdu_cb->flags;
1389 
1390 		len = 0;
1391 		for (i = 0; i < pdu_cb->nr_dfrags; hfrag_idx++, i++) {
1392 			memcpy(&hssi->frags[hfrag_idx],
1393 			       &ssi->frags[pdu_cb->dfrag_idx + i],
1394 			       sizeof(skb_frag_t));
1395 
1396 			get_page(skb_frag_page(&hssi->frags[hfrag_idx]));
1397 
1398 			len += hssi->frags[hfrag_idx].size;
1399 
1400 			hssi->nr_frags++;
1401 			hpdu_cb->frags++;
1402 		}
1403 
1404 		hpdu_cb->dlen = pdu_cb->dlen;
1405 		hpdu_cb->doffset = hpdu_cb->hlen;
1406 		hpdu_cb->nr_dfrags = pdu_cb->nr_dfrags;
1407 		hpdu_cb->dfrag_idx = 1;
1408 		hskb->len += len;
1409 		hskb->data_len += len;
1410 		hskb->truesize += len;
1411 	}
1412 
1413 	if (pdu_cb->flags & PDUCBF_RX_STATUS) {
1414 		hpdu_cb->flags |= pdu_cb->flags;
1415 
1416 		if (hpdu_cb->flags & PDUCBF_RX_DATA)
1417 			hpdu_cb->flags &= ~PDUCBF_RX_DATA_DDPD;
1418 
1419 		hpdu_cb->ddigest = pdu_cb->ddigest;
1420 		hpdu_cb->pdulen = pdu_cb->pdulen;
1421 	}
1422 }
1423 
1424 static int cxgbit_process_lro_skb(struct cxgbit_sock *csk, struct sk_buff *skb)
1425 {
1426 	struct cxgbit_lro_cb *lro_cb = cxgbit_skb_lro_cb(skb);
1427 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_skb_lro_pdu_cb(skb, 0);
1428 	u8 pdu_idx = 0, last_idx = 0;
1429 	int ret = 0;
1430 
1431 	if (!pdu_cb->complete) {
1432 		cxgbit_lro_skb_merge(csk, skb, 0);
1433 
1434 		if (pdu_cb->flags & PDUCBF_RX_STATUS) {
1435 			struct sk_buff *hskb = csk->lro_hskb;
1436 
1437 			ret = cxgbit_process_iscsi_pdu(csk, hskb, 0);
1438 
1439 			cxgbit_lro_hskb_reset(csk);
1440 
1441 			if (ret < 0)
1442 				goto out;
1443 		}
1444 
1445 		pdu_idx = 1;
1446 	}
1447 
1448 	if (lro_cb->pdu_idx)
1449 		last_idx = lro_cb->pdu_idx - 1;
1450 
1451 	for (; pdu_idx <= last_idx; pdu_idx++) {
1452 		ret = cxgbit_process_iscsi_pdu(csk, skb, pdu_idx);
1453 		if (ret < 0)
1454 			goto out;
1455 	}
1456 
1457 	if ((!lro_cb->complete) && lro_cb->pdu_idx)
1458 		cxgbit_lro_skb_merge(csk, skb, lro_cb->pdu_idx);
1459 
1460 out:
1461 	return ret;
1462 }
1463 
1464 static int cxgbit_rx_lro_skb(struct cxgbit_sock *csk, struct sk_buff *skb)
1465 {
1466 	struct cxgbit_lro_cb *lro_cb = cxgbit_skb_lro_cb(skb);
1467 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_skb_lro_pdu_cb(skb, 0);
1468 	int ret = -1;
1469 
1470 	if ((pdu_cb->flags & PDUCBF_RX_HDR) &&
1471 	    (pdu_cb->seq != csk->rcv_nxt)) {
1472 		pr_info("csk 0x%p, tid 0x%x, seq 0x%x != 0x%x.\n",
1473 			csk, csk->tid, pdu_cb->seq, csk->rcv_nxt);
1474 		cxgbit_lro_skb_dump(skb);
1475 		return ret;
1476 	}
1477 
1478 	csk->rcv_nxt += lro_cb->pdu_totallen;
1479 
1480 	ret = cxgbit_process_lro_skb(csk, skb);
1481 
1482 	csk->rx_credits += lro_cb->pdu_totallen;
1483 
1484 	if (csk->rx_credits >= (csk->rcv_win / 4))
1485 		cxgbit_rx_data_ack(csk);
1486 
1487 	return ret;
1488 }
1489 
1490 static int cxgbit_rx_skb(struct cxgbit_sock *csk, struct sk_buff *skb)
1491 {
1492 	int ret = -1;
1493 
1494 	if (likely(cxgbit_skcb_flags(skb) & SKCBF_RX_LRO))
1495 		ret = cxgbit_rx_lro_skb(csk, skb);
1496 
1497 	__kfree_skb(skb);
1498 	return ret;
1499 }
1500 
1501 static bool cxgbit_rxq_len(struct cxgbit_sock *csk, struct sk_buff_head *rxq)
1502 {
1503 	spin_lock_bh(&csk->rxq.lock);
1504 	if (skb_queue_len(&csk->rxq)) {
1505 		skb_queue_splice_init(&csk->rxq, rxq);
1506 		spin_unlock_bh(&csk->rxq.lock);
1507 		return true;
1508 	}
1509 	spin_unlock_bh(&csk->rxq.lock);
1510 	return false;
1511 }
1512 
1513 static int cxgbit_wait_rxq(struct cxgbit_sock *csk)
1514 {
1515 	struct sk_buff *skb;
1516 	struct sk_buff_head rxq;
1517 
1518 	skb_queue_head_init(&rxq);
1519 
1520 	wait_event_interruptible(csk->waitq, cxgbit_rxq_len(csk, &rxq));
1521 
1522 	if (signal_pending(current))
1523 		goto out;
1524 
1525 	while ((skb = __skb_dequeue(&rxq))) {
1526 		if (cxgbit_rx_skb(csk, skb))
1527 			goto out;
1528 	}
1529 
1530 	return 0;
1531 out:
1532 	__skb_queue_purge(&rxq);
1533 	return -1;
1534 }
1535 
1536 int cxgbit_get_login_rx(struct iscsi_conn *conn, struct iscsi_login *login)
1537 {
1538 	struct cxgbit_sock *csk = conn->context;
1539 	int ret = -1;
1540 
1541 	while (!test_and_clear_bit(CSK_LOGIN_PDU_DONE, &csk->com.flags)) {
1542 		ret = cxgbit_wait_rxq(csk);
1543 		if (ret) {
1544 			clear_bit(CSK_LOGIN_PDU_DONE, &csk->com.flags);
1545 			break;
1546 		}
1547 	}
1548 
1549 	return ret;
1550 }
1551 
1552 void cxgbit_get_rx_pdu(struct iscsi_conn *conn)
1553 {
1554 	struct cxgbit_sock *csk = conn->context;
1555 
1556 	while (!kthread_should_stop()) {
1557 		iscsit_thread_check_cpumask(conn, current, 0);
1558 		if (cxgbit_wait_rxq(csk))
1559 			return;
1560 	}
1561 }
1562