1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2016 Chelsio Communications, Inc.
4  */
5 
6 #include <linux/workqueue.h>
7 #include <linux/kthread.h>
8 #include <linux/sched/signal.h>
9 
10 #include <asm/unaligned.h>
11 #include <net/tcp.h>
12 #include <target/target_core_base.h>
13 #include <target/target_core_fabric.h>
14 #include "cxgbit.h"
15 
16 struct sge_opaque_hdr {
17 	void *dev;
18 	dma_addr_t addr[MAX_SKB_FRAGS + 1];
19 };
20 
21 static const u8 cxgbit_digest_len[] = {0, 4, 4, 8};
22 
23 #define TX_HDR_LEN (sizeof(struct sge_opaque_hdr) + \
24 		    sizeof(struct fw_ofld_tx_data_wr))
25 
26 static struct sk_buff *
27 __cxgbit_alloc_skb(struct cxgbit_sock *csk, u32 len, bool iso)
28 {
29 	struct sk_buff *skb = NULL;
30 	u8 submode = 0;
31 	int errcode;
32 	static const u32 hdr_len = TX_HDR_LEN + ISCSI_HDR_LEN;
33 
34 	if (len) {
35 		skb = alloc_skb_with_frags(hdr_len, len,
36 					   0, &errcode,
37 					   GFP_KERNEL);
38 		if (!skb)
39 			return NULL;
40 
41 		skb_reserve(skb, TX_HDR_LEN);
42 		skb_reset_transport_header(skb);
43 		__skb_put(skb, ISCSI_HDR_LEN);
44 		skb->data_len = len;
45 		skb->len += len;
46 		submode |= (csk->submode & CXGBIT_SUBMODE_DCRC);
47 
48 	} else {
49 		u32 iso_len = iso ? sizeof(struct cpl_tx_data_iso) : 0;
50 
51 		skb = alloc_skb(hdr_len + iso_len, GFP_KERNEL);
52 		if (!skb)
53 			return NULL;
54 
55 		skb_reserve(skb, TX_HDR_LEN + iso_len);
56 		skb_reset_transport_header(skb);
57 		__skb_put(skb, ISCSI_HDR_LEN);
58 	}
59 
60 	submode |= (csk->submode & CXGBIT_SUBMODE_HCRC);
61 	cxgbit_skcb_submode(skb) = submode;
62 	cxgbit_skcb_tx_extralen(skb) = cxgbit_digest_len[submode];
63 	cxgbit_skcb_flags(skb) |= SKCBF_TX_NEED_HDR;
64 	return skb;
65 }
66 
67 static struct sk_buff *cxgbit_alloc_skb(struct cxgbit_sock *csk, u32 len)
68 {
69 	return __cxgbit_alloc_skb(csk, len, false);
70 }
71 
72 /*
73  * cxgbit_is_ofld_imm - check whether a packet can be sent as immediate data
74  * @skb: the packet
75  *
76  * Returns true if a packet can be sent as an offload WR with immediate
77  * data.  We currently use the same limit as for Ethernet packets.
78  */
79 static int cxgbit_is_ofld_imm(const struct sk_buff *skb)
80 {
81 	int length = skb->len;
82 
83 	if (likely(cxgbit_skcb_flags(skb) & SKCBF_TX_NEED_HDR))
84 		length += sizeof(struct fw_ofld_tx_data_wr);
85 
86 	if (likely(cxgbit_skcb_flags(skb) & SKCBF_TX_ISO))
87 		length += sizeof(struct cpl_tx_data_iso);
88 
89 #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 = __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 	const struct cxgb4_lld_info *lldi = &csk->com.cdev->lldi;
165 	u32 submode = cxgbit_skcb_submode(skb);
166 	u32 wr_ulp_mode = 0;
167 	u32 hdr_size = sizeof(*req);
168 	u32 opcode = FW_OFLD_TX_DATA_WR;
169 	u32 immlen = 0;
170 	u32 force = is_t5(lldi->adapter_type) ? TX_FORCE_V(!submode) :
171 		    T6_TX_FORCE_F;
172 
173 	if (cxgbit_skcb_flags(skb) & SKCBF_TX_ISO) {
174 		opcode = FW_ISCSI_TX_DATA_WR;
175 		immlen += sizeof(struct cpl_tx_data_iso);
176 		hdr_size += sizeof(struct cpl_tx_data_iso);
177 		submode |= 8;
178 	}
179 
180 	if (cxgbit_is_ofld_imm(skb))
181 		immlen += dlen;
182 
183 	req = __skb_push(skb, hdr_size);
184 	req->op_to_immdlen = cpu_to_be32(FW_WR_OP_V(opcode) |
185 					FW_WR_COMPL_V(compl) |
186 					FW_WR_IMMDLEN_V(immlen));
187 	req->flowid_len16 = cpu_to_be32(FW_WR_FLOWID_V(csk->tid) |
188 					FW_WR_LEN16_V(credits));
189 	req->plen = htonl(len);
190 	wr_ulp_mode = FW_OFLD_TX_DATA_WR_ULPMODE_V(ULP_MODE_ISCSI) |
191 				FW_OFLD_TX_DATA_WR_ULPSUBMODE_V(submode);
192 
193 	req->tunnel_to_proxy = htonl((wr_ulp_mode) | force |
194 		 FW_OFLD_TX_DATA_WR_SHOVE_V(skb_peek(&csk->txq) ? 0 : 1));
195 }
196 
197 static void cxgbit_arp_failure_skb_discard(void *handle, struct sk_buff *skb)
198 {
199 	kfree_skb(skb);
200 }
201 
202 void cxgbit_push_tx_frames(struct cxgbit_sock *csk)
203 {
204 	struct sk_buff *skb;
205 
206 	while (csk->wr_cred && ((skb = skb_peek(&csk->txq)) != NULL)) {
207 		u32 dlen = skb->len;
208 		u32 len = skb->len;
209 		u32 credits_needed;
210 		u32 compl = 0;
211 		u32 flowclen16 = 0;
212 		u32 iso_cpl_len = 0;
213 
214 		if (cxgbit_skcb_flags(skb) & SKCBF_TX_ISO)
215 			iso_cpl_len = sizeof(struct cpl_tx_data_iso);
216 
217 		if (cxgbit_is_ofld_imm(skb))
218 			credits_needed = DIV_ROUND_UP(dlen + iso_cpl_len, 16);
219 		else
220 			credits_needed = DIV_ROUND_UP((8 *
221 					cxgbit_calc_tx_flits_ofld(skb)) +
222 					iso_cpl_len, 16);
223 
224 		if (likely(cxgbit_skcb_flags(skb) & SKCBF_TX_NEED_HDR))
225 			credits_needed += DIV_ROUND_UP(
226 				sizeof(struct fw_ofld_tx_data_wr), 16);
227 		/*
228 		 * Assumes the initial credits is large enough to support
229 		 * fw_flowc_wr plus largest possible first payload
230 		 */
231 
232 		if (!test_and_set_bit(CSK_TX_DATA_SENT, &csk->com.flags)) {
233 			flowclen16 = cxgbit_send_tx_flowc_wr(csk);
234 			csk->wr_cred -= flowclen16;
235 			csk->wr_una_cred += flowclen16;
236 		}
237 
238 		if (csk->wr_cred < credits_needed) {
239 			pr_debug("csk 0x%p, skb %u/%u, wr %d < %u.\n",
240 				 csk, skb->len, skb->data_len,
241 				 credits_needed, csk->wr_cred);
242 			break;
243 		}
244 		__skb_unlink(skb, &csk->txq);
245 		set_wr_txq(skb, CPL_PRIORITY_DATA, csk->txq_idx);
246 		skb->csum = (__force __wsum)(credits_needed + flowclen16);
247 		csk->wr_cred -= credits_needed;
248 		csk->wr_una_cred += credits_needed;
249 
250 		pr_debug("csk 0x%p, skb %u/%u, wr %d, left %u, unack %u.\n",
251 			 csk, skb->len, skb->data_len, credits_needed,
252 			 csk->wr_cred, csk->wr_una_cred);
253 
254 		if (likely(cxgbit_skcb_flags(skb) & SKCBF_TX_NEED_HDR)) {
255 			len += cxgbit_skcb_tx_extralen(skb);
256 
257 			if ((csk->wr_una_cred >= (csk->wr_max_cred / 2)) ||
258 			    (!before(csk->write_seq,
259 				     csk->snd_una + csk->snd_win))) {
260 				compl = 1;
261 				csk->wr_una_cred = 0;
262 			}
263 
264 			cxgbit_tx_data_wr(csk, skb, dlen, len, credits_needed,
265 					  compl);
266 			csk->snd_nxt += len;
267 
268 		} else if ((cxgbit_skcb_flags(skb) & SKCBF_TX_FLAG_COMPL) ||
269 			   (csk->wr_una_cred >= (csk->wr_max_cred / 2))) {
270 			struct cpl_close_con_req *req =
271 				(struct cpl_close_con_req *)skb->data;
272 			req->wr.wr_hi |= htonl(FW_WR_COMPL_F);
273 			csk->wr_una_cred = 0;
274 		}
275 
276 		cxgbit_sock_enqueue_wr(csk, skb);
277 		t4_set_arp_err_handler(skb, csk,
278 				       cxgbit_arp_failure_skb_discard);
279 
280 		pr_debug("csk 0x%p,%u, skb 0x%p, %u.\n",
281 			 csk, csk->tid, skb, len);
282 
283 		cxgbit_l2t_send(csk->com.cdev, skb, csk->l2t);
284 	}
285 }
286 
287 static void cxgbit_unlock_sock(struct cxgbit_sock *csk)
288 {
289 	struct sk_buff_head backlogq;
290 	struct sk_buff *skb;
291 	void (*fn)(struct cxgbit_sock *, struct sk_buff *);
292 
293 	skb_queue_head_init(&backlogq);
294 
295 	spin_lock_bh(&csk->lock);
296 	while (skb_queue_len(&csk->backlogq)) {
297 		skb_queue_splice_init(&csk->backlogq, &backlogq);
298 		spin_unlock_bh(&csk->lock);
299 
300 		while ((skb = __skb_dequeue(&backlogq))) {
301 			fn = cxgbit_skcb_rx_backlog_fn(skb);
302 			fn(csk, skb);
303 		}
304 
305 		spin_lock_bh(&csk->lock);
306 	}
307 
308 	csk->lock_owner = false;
309 	spin_unlock_bh(&csk->lock);
310 }
311 
312 static int cxgbit_queue_skb(struct cxgbit_sock *csk, struct sk_buff *skb)
313 {
314 	int ret = 0;
315 
316 	spin_lock_bh(&csk->lock);
317 	csk->lock_owner = true;
318 	spin_unlock_bh(&csk->lock);
319 
320 	if (unlikely((csk->com.state != CSK_STATE_ESTABLISHED) ||
321 		     signal_pending(current))) {
322 		__kfree_skb(skb);
323 		__skb_queue_purge(&csk->ppodq);
324 		ret = -1;
325 		goto unlock;
326 	}
327 
328 	csk->write_seq += skb->len +
329 			  cxgbit_skcb_tx_extralen(skb);
330 
331 	skb_queue_splice_tail_init(&csk->ppodq, &csk->txq);
332 	__skb_queue_tail(&csk->txq, skb);
333 	cxgbit_push_tx_frames(csk);
334 
335 unlock:
336 	cxgbit_unlock_sock(csk);
337 	return ret;
338 }
339 
340 static int
341 cxgbit_map_skb(struct iscsi_cmd *cmd, struct sk_buff *skb, u32 data_offset,
342 	       u32 data_length)
343 {
344 	u32 i = 0, nr_frags = MAX_SKB_FRAGS;
345 	u32 padding = ((-data_length) & 3);
346 	struct scatterlist *sg;
347 	struct page *page;
348 	unsigned int page_off;
349 
350 	if (padding)
351 		nr_frags--;
352 
353 	/*
354 	 * We know each entry in t_data_sg contains a page.
355 	 */
356 	sg = &cmd->se_cmd.t_data_sg[data_offset / PAGE_SIZE];
357 	page_off = (data_offset % PAGE_SIZE);
358 
359 	while (data_length && (i < nr_frags)) {
360 		u32 cur_len = min_t(u32, data_length, sg->length - page_off);
361 
362 		page = sg_page(sg);
363 
364 		get_page(page);
365 		skb_fill_page_desc(skb, i, page, sg->offset + page_off,
366 				   cur_len);
367 		skb->data_len += cur_len;
368 		skb->len += cur_len;
369 		skb->truesize += cur_len;
370 
371 		data_length -= cur_len;
372 		page_off = 0;
373 		sg = sg_next(sg);
374 		i++;
375 	}
376 
377 	if (data_length)
378 		return -1;
379 
380 	if (padding) {
381 		page = alloc_page(GFP_KERNEL | __GFP_ZERO);
382 		if (!page)
383 			return -1;
384 		skb_fill_page_desc(skb, i, page, 0, padding);
385 		skb->data_len += padding;
386 		skb->len += padding;
387 		skb->truesize += padding;
388 	}
389 
390 	return 0;
391 }
392 
393 static int
394 cxgbit_tx_datain_iso(struct cxgbit_sock *csk, struct iscsi_cmd *cmd,
395 		     struct iscsi_datain_req *dr)
396 {
397 	struct iscsi_conn *conn = csk->conn;
398 	struct sk_buff *skb;
399 	struct iscsi_datain datain;
400 	struct cxgbit_iso_info iso_info;
401 	u32 data_length = cmd->se_cmd.data_length;
402 	u32 mrdsl = conn->conn_ops->MaxRecvDataSegmentLength;
403 	u32 num_pdu, plen, tx_data = 0;
404 	bool task_sense = !!(cmd->se_cmd.se_cmd_flags &
405 		SCF_TRANSPORT_TASK_SENSE);
406 	bool set_statsn = false;
407 	int ret = -1;
408 
409 	while (data_length) {
410 		num_pdu = (data_length + mrdsl - 1) / mrdsl;
411 		if (num_pdu > csk->max_iso_npdu)
412 			num_pdu = csk->max_iso_npdu;
413 
414 		plen = num_pdu * mrdsl;
415 		if (plen > data_length)
416 			plen = data_length;
417 
418 		skb = __cxgbit_alloc_skb(csk, 0, true);
419 		if (unlikely(!skb))
420 			return -ENOMEM;
421 
422 		memset(skb->data, 0, ISCSI_HDR_LEN);
423 		cxgbit_skcb_flags(skb) |= SKCBF_TX_ISO;
424 		cxgbit_skcb_submode(skb) |= (csk->submode &
425 				CXGBIT_SUBMODE_DCRC);
426 		cxgbit_skcb_tx_extralen(skb) = (num_pdu *
427 				cxgbit_digest_len[cxgbit_skcb_submode(skb)]) +
428 						((num_pdu - 1) * ISCSI_HDR_LEN);
429 
430 		memset(&datain, 0, sizeof(struct iscsi_datain));
431 		memset(&iso_info, 0, sizeof(iso_info));
432 
433 		if (!tx_data)
434 			iso_info.flags |= CXGBIT_ISO_FSLICE;
435 
436 		if (!(data_length - plen)) {
437 			iso_info.flags |= CXGBIT_ISO_LSLICE;
438 			if (!task_sense) {
439 				datain.flags = ISCSI_FLAG_DATA_STATUS;
440 				iscsit_increment_maxcmdsn(cmd, conn->sess);
441 				cmd->stat_sn = conn->stat_sn++;
442 				set_statsn = true;
443 			}
444 		}
445 
446 		iso_info.burst_len = num_pdu * mrdsl;
447 		iso_info.mpdu = mrdsl;
448 		iso_info.len = ISCSI_HDR_LEN + plen;
449 
450 		cxgbit_cpl_tx_data_iso(skb, &iso_info);
451 
452 		datain.offset = tx_data;
453 		datain.data_sn = cmd->data_sn - 1;
454 
455 		iscsit_build_datain_pdu(cmd, conn, &datain,
456 					(struct iscsi_data_rsp *)skb->data,
457 					set_statsn);
458 
459 		ret = cxgbit_map_skb(cmd, skb, tx_data, plen);
460 		if (unlikely(ret)) {
461 			__kfree_skb(skb);
462 			goto out;
463 		}
464 
465 		ret = cxgbit_queue_skb(csk, skb);
466 		if (unlikely(ret))
467 			goto out;
468 
469 		tx_data += plen;
470 		data_length -= plen;
471 
472 		cmd->read_data_done += plen;
473 		cmd->data_sn += num_pdu;
474 	}
475 
476 	dr->dr_complete = DATAIN_COMPLETE_NORMAL;
477 
478 	return 0;
479 
480 out:
481 	return ret;
482 }
483 
484 static int
485 cxgbit_tx_datain(struct cxgbit_sock *csk, struct iscsi_cmd *cmd,
486 		 const struct iscsi_datain *datain)
487 {
488 	struct sk_buff *skb;
489 	int ret = 0;
490 
491 	skb = cxgbit_alloc_skb(csk, 0);
492 	if (unlikely(!skb))
493 		return -ENOMEM;
494 
495 	memcpy(skb->data, cmd->pdu, ISCSI_HDR_LEN);
496 
497 	if (datain->length) {
498 		cxgbit_skcb_submode(skb) |= (csk->submode &
499 				CXGBIT_SUBMODE_DCRC);
500 		cxgbit_skcb_tx_extralen(skb) =
501 				cxgbit_digest_len[cxgbit_skcb_submode(skb)];
502 	}
503 
504 	ret = cxgbit_map_skb(cmd, skb, datain->offset, datain->length);
505 	if (ret < 0) {
506 		__kfree_skb(skb);
507 		return ret;
508 	}
509 
510 	return cxgbit_queue_skb(csk, skb);
511 }
512 
513 static int
514 cxgbit_xmit_datain_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
515 		       struct iscsi_datain_req *dr,
516 		       const struct iscsi_datain *datain)
517 {
518 	struct cxgbit_sock *csk = conn->context;
519 	u32 data_length = cmd->se_cmd.data_length;
520 	u32 padding = ((-data_length) & 3);
521 	u32 mrdsl = conn->conn_ops->MaxRecvDataSegmentLength;
522 
523 	if ((data_length > mrdsl) && (!dr->recovery) &&
524 	    (!padding) && (!datain->offset) && csk->max_iso_npdu) {
525 		atomic_long_add(data_length - datain->length,
526 				&conn->sess->tx_data_octets);
527 		return cxgbit_tx_datain_iso(csk, cmd, dr);
528 	}
529 
530 	return cxgbit_tx_datain(csk, cmd, datain);
531 }
532 
533 static int
534 cxgbit_xmit_nondatain_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
535 			  const void *data_buf, u32 data_buf_len)
536 {
537 	struct cxgbit_sock *csk = conn->context;
538 	struct sk_buff *skb;
539 	u32 padding = ((-data_buf_len) & 3);
540 
541 	skb = cxgbit_alloc_skb(csk, data_buf_len + padding);
542 	if (unlikely(!skb))
543 		return -ENOMEM;
544 
545 	memcpy(skb->data, cmd->pdu, ISCSI_HDR_LEN);
546 
547 	if (data_buf_len) {
548 		u32 pad_bytes = 0;
549 
550 		skb_store_bits(skb, ISCSI_HDR_LEN, data_buf, data_buf_len);
551 
552 		if (padding)
553 			skb_store_bits(skb, ISCSI_HDR_LEN + data_buf_len,
554 				       &pad_bytes, padding);
555 	}
556 
557 	cxgbit_skcb_tx_extralen(skb) = cxgbit_digest_len[
558 				       cxgbit_skcb_submode(skb)];
559 
560 	return cxgbit_queue_skb(csk, skb);
561 }
562 
563 int
564 cxgbit_xmit_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
565 		struct iscsi_datain_req *dr, const void *buf, u32 buf_len)
566 {
567 	if (dr)
568 		return cxgbit_xmit_datain_pdu(conn, cmd, dr, buf);
569 	else
570 		return cxgbit_xmit_nondatain_pdu(conn, cmd, buf, buf_len);
571 }
572 
573 int cxgbit_validate_params(struct iscsi_conn *conn)
574 {
575 	struct cxgbit_sock *csk = conn->context;
576 	struct cxgbit_device *cdev = csk->com.cdev;
577 	struct iscsi_param *param;
578 	u32 max_xmitdsl;
579 
580 	param = iscsi_find_param_from_key(MAXXMITDATASEGMENTLENGTH,
581 					  conn->param_list);
582 	if (!param)
583 		return -1;
584 
585 	if (kstrtou32(param->value, 0, &max_xmitdsl) < 0)
586 		return -1;
587 
588 	if (max_xmitdsl > cdev->mdsl) {
589 		if (iscsi_change_param_sprintf(
590 			conn, "MaxXmitDataSegmentLength=%u", cdev->mdsl))
591 			return -1;
592 	}
593 
594 	return 0;
595 }
596 
597 static int cxgbit_set_digest(struct cxgbit_sock *csk)
598 {
599 	struct iscsi_conn *conn = csk->conn;
600 	struct iscsi_param *param;
601 
602 	param = iscsi_find_param_from_key(HEADERDIGEST, conn->param_list);
603 	if (!param) {
604 		pr_err("param not found key %s\n", HEADERDIGEST);
605 		return -1;
606 	}
607 
608 	if (!strcmp(param->value, CRC32C))
609 		csk->submode |= CXGBIT_SUBMODE_HCRC;
610 
611 	param = iscsi_find_param_from_key(DATADIGEST, conn->param_list);
612 	if (!param) {
613 		csk->submode = 0;
614 		pr_err("param not found key %s\n", DATADIGEST);
615 		return -1;
616 	}
617 
618 	if (!strcmp(param->value, CRC32C))
619 		csk->submode |= CXGBIT_SUBMODE_DCRC;
620 
621 	if (cxgbit_setup_conn_digest(csk)) {
622 		csk->submode = 0;
623 		return -1;
624 	}
625 
626 	return 0;
627 }
628 
629 static int cxgbit_set_iso_npdu(struct cxgbit_sock *csk)
630 {
631 	struct iscsi_conn *conn = csk->conn;
632 	struct iscsi_conn_ops *conn_ops = conn->conn_ops;
633 	struct iscsi_param *param;
634 	u32 mrdsl, mbl;
635 	u32 max_npdu, max_iso_npdu;
636 	u32 max_iso_payload;
637 
638 	if (conn->login->leading_connection) {
639 		param = iscsi_find_param_from_key(MAXBURSTLENGTH,
640 						  conn->param_list);
641 		if (!param) {
642 			pr_err("param not found key %s\n", MAXBURSTLENGTH);
643 			return -1;
644 		}
645 
646 		if (kstrtou32(param->value, 0, &mbl) < 0)
647 			return -1;
648 	} else {
649 		mbl = conn->sess->sess_ops->MaxBurstLength;
650 	}
651 
652 	mrdsl = conn_ops->MaxRecvDataSegmentLength;
653 	max_npdu = mbl / mrdsl;
654 
655 	max_iso_payload = rounddown(CXGBIT_MAX_ISO_PAYLOAD, csk->emss);
656 
657 	max_iso_npdu = max_iso_payload /
658 		       (ISCSI_HDR_LEN + mrdsl +
659 			cxgbit_digest_len[csk->submode]);
660 
661 	csk->max_iso_npdu = min(max_npdu, max_iso_npdu);
662 
663 	if (csk->max_iso_npdu <= 1)
664 		csk->max_iso_npdu = 0;
665 
666 	return 0;
667 }
668 
669 /*
670  * cxgbit_seq_pdu_inorder()
671  * @csk: pointer to cxgbit socket structure
672  *
673  * This function checks whether data sequence and data
674  * pdu are in order.
675  *
676  * Return: returns -1 on error, 0 if data sequence and
677  * data pdu are in order, 1 if data sequence or data pdu
678  * is not in order.
679  */
680 static int cxgbit_seq_pdu_inorder(struct cxgbit_sock *csk)
681 {
682 	struct iscsi_conn *conn = csk->conn;
683 	struct iscsi_param *param;
684 
685 	if (conn->login->leading_connection) {
686 		param = iscsi_find_param_from_key(DATASEQUENCEINORDER,
687 						  conn->param_list);
688 		if (!param) {
689 			pr_err("param not found key %s\n", DATASEQUENCEINORDER);
690 			return -1;
691 		}
692 
693 		if (strcmp(param->value, YES))
694 			return 1;
695 
696 		param = iscsi_find_param_from_key(DATAPDUINORDER,
697 						  conn->param_list);
698 		if (!param) {
699 			pr_err("param not found key %s\n", DATAPDUINORDER);
700 			return -1;
701 		}
702 
703 		if (strcmp(param->value, YES))
704 			return 1;
705 
706 	} else {
707 		if (!conn->sess->sess_ops->DataSequenceInOrder)
708 			return 1;
709 		if (!conn->sess->sess_ops->DataPDUInOrder)
710 			return 1;
711 	}
712 
713 	return 0;
714 }
715 
716 static int cxgbit_set_params(struct iscsi_conn *conn)
717 {
718 	struct cxgbit_sock *csk = conn->context;
719 	struct cxgbit_device *cdev = csk->com.cdev;
720 	struct cxgbi_ppm *ppm = *csk->com.cdev->lldi.iscsi_ppm;
721 	struct iscsi_conn_ops *conn_ops = conn->conn_ops;
722 	struct iscsi_param *param;
723 	u8 erl;
724 
725 	if (conn_ops->MaxRecvDataSegmentLength > cdev->mdsl)
726 		conn_ops->MaxRecvDataSegmentLength = cdev->mdsl;
727 
728 	if (cxgbit_set_digest(csk))
729 		return -1;
730 
731 	if (conn->login->leading_connection) {
732 		param = iscsi_find_param_from_key(ERRORRECOVERYLEVEL,
733 						  conn->param_list);
734 		if (!param) {
735 			pr_err("param not found key %s\n", ERRORRECOVERYLEVEL);
736 			return -1;
737 		}
738 		if (kstrtou8(param->value, 0, &erl) < 0)
739 			return -1;
740 	} else {
741 		erl = conn->sess->sess_ops->ErrorRecoveryLevel;
742 	}
743 
744 	if (!erl) {
745 		int ret;
746 
747 		ret = cxgbit_seq_pdu_inorder(csk);
748 		if (ret < 0) {
749 			return -1;
750 		} else if (ret > 0) {
751 			if (is_t5(cdev->lldi.adapter_type))
752 				goto enable_ddp;
753 			else
754 				return 0;
755 		}
756 
757 		if (test_bit(CDEV_ISO_ENABLE, &cdev->flags)) {
758 			if (cxgbit_set_iso_npdu(csk))
759 				return -1;
760 		}
761 
762 enable_ddp:
763 		if (test_bit(CDEV_DDP_ENABLE, &cdev->flags)) {
764 			if (cxgbit_setup_conn_pgidx(csk,
765 						    ppm->tformat.pgsz_idx_dflt))
766 				return -1;
767 			set_bit(CSK_DDP_ENABLE, &csk->com.flags);
768 		}
769 	}
770 
771 	return 0;
772 }
773 
774 int
775 cxgbit_put_login_tx(struct iscsi_conn *conn, struct iscsi_login *login,
776 		    u32 length)
777 {
778 	struct cxgbit_sock *csk = conn->context;
779 	struct sk_buff *skb;
780 	u32 padding_buf = 0;
781 	u8 padding = ((-length) & 3);
782 
783 	skb = cxgbit_alloc_skb(csk, length + padding);
784 	if (!skb)
785 		return -ENOMEM;
786 	skb_store_bits(skb, 0, login->rsp, ISCSI_HDR_LEN);
787 	skb_store_bits(skb, ISCSI_HDR_LEN, login->rsp_buf, length);
788 
789 	if (padding)
790 		skb_store_bits(skb, ISCSI_HDR_LEN + length,
791 			       &padding_buf, padding);
792 
793 	if (login->login_complete) {
794 		if (cxgbit_set_params(conn)) {
795 			kfree_skb(skb);
796 			return -1;
797 		}
798 
799 		set_bit(CSK_LOGIN_DONE, &csk->com.flags);
800 	}
801 
802 	if (cxgbit_queue_skb(csk, skb))
803 		return -1;
804 
805 	if ((!login->login_complete) && (!login->login_failed))
806 		schedule_delayed_work(&conn->login_work, 0);
807 
808 	return 0;
809 }
810 
811 static void
812 cxgbit_skb_copy_to_sg(struct sk_buff *skb, struct scatterlist *sg,
813 		      unsigned int nents, u32 skip)
814 {
815 	struct skb_seq_state st;
816 	const u8 *buf;
817 	unsigned int consumed = 0, buf_len;
818 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(skb);
819 
820 	skb_prepare_seq_read(skb, pdu_cb->doffset,
821 			     pdu_cb->doffset + pdu_cb->dlen,
822 			     &st);
823 
824 	while (true) {
825 		buf_len = skb_seq_read(consumed, &buf, &st);
826 		if (!buf_len) {
827 			skb_abort_seq_read(&st);
828 			break;
829 		}
830 
831 		consumed += sg_pcopy_from_buffer(sg, nents, (void *)buf,
832 						 buf_len, skip + consumed);
833 	}
834 }
835 
836 static struct iscsi_cmd *cxgbit_allocate_cmd(struct cxgbit_sock *csk)
837 {
838 	struct iscsi_conn *conn = csk->conn;
839 	struct cxgbi_ppm *ppm = cdev2ppm(csk->com.cdev);
840 	struct cxgbit_cmd *ccmd;
841 	struct iscsi_cmd *cmd;
842 
843 	cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
844 	if (!cmd) {
845 		pr_err("Unable to allocate iscsi_cmd + cxgbit_cmd\n");
846 		return NULL;
847 	}
848 
849 	ccmd = iscsit_priv_cmd(cmd);
850 	ccmd->ttinfo.tag = ppm->tformat.no_ddp_mask;
851 	ccmd->setup_ddp = true;
852 
853 	return cmd;
854 }
855 
856 static int
857 cxgbit_handle_immediate_data(struct iscsi_cmd *cmd, struct iscsi_scsi_req *hdr,
858 			     u32 length)
859 {
860 	struct iscsi_conn *conn = cmd->conn;
861 	struct cxgbit_sock *csk = conn->context;
862 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
863 
864 	if (pdu_cb->flags & PDUCBF_RX_DCRC_ERR) {
865 		pr_err("ImmediateData CRC32C DataDigest error\n");
866 		if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
867 			pr_err("Unable to recover from"
868 			       " Immediate Data digest failure while"
869 			       " in ERL=0.\n");
870 			iscsit_reject_cmd(cmd, ISCSI_REASON_DATA_DIGEST_ERROR,
871 					  (unsigned char *)hdr);
872 			return IMMEDIATE_DATA_CANNOT_RECOVER;
873 		}
874 
875 		iscsit_reject_cmd(cmd, ISCSI_REASON_DATA_DIGEST_ERROR,
876 				  (unsigned char *)hdr);
877 		return IMMEDIATE_DATA_ERL1_CRC_FAILURE;
878 	}
879 
880 	if (cmd->se_cmd.se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
881 		struct cxgbit_cmd *ccmd = iscsit_priv_cmd(cmd);
882 		struct skb_shared_info *ssi = skb_shinfo(csk->skb);
883 		skb_frag_t *dfrag = &ssi->frags[pdu_cb->dfrag_idx];
884 
885 		sg_init_table(&ccmd->sg, 1);
886 		sg_set_page(&ccmd->sg, skb_frag_page(dfrag),
887 				skb_frag_size(dfrag), skb_frag_off(dfrag));
888 		get_page(skb_frag_page(dfrag));
889 
890 		cmd->se_cmd.t_data_sg = &ccmd->sg;
891 		cmd->se_cmd.t_data_nents = 1;
892 
893 		ccmd->release = true;
894 	} else {
895 		struct scatterlist *sg = &cmd->se_cmd.t_data_sg[0];
896 		u32 sg_nents = max(1UL, DIV_ROUND_UP(pdu_cb->dlen, PAGE_SIZE));
897 
898 		cxgbit_skb_copy_to_sg(csk->skb, sg, sg_nents, 0);
899 	}
900 
901 	cmd->write_data_done += pdu_cb->dlen;
902 
903 	if (cmd->write_data_done == cmd->se_cmd.data_length) {
904 		spin_lock_bh(&cmd->istate_lock);
905 		cmd->cmd_flags |= ICF_GOT_LAST_DATAOUT;
906 		cmd->i_state = ISTATE_RECEIVED_LAST_DATAOUT;
907 		spin_unlock_bh(&cmd->istate_lock);
908 	}
909 
910 	return IMMEDIATE_DATA_NORMAL_OPERATION;
911 }
912 
913 static int
914 cxgbit_get_immediate_data(struct iscsi_cmd *cmd, struct iscsi_scsi_req *hdr,
915 			  bool dump_payload)
916 {
917 	struct iscsi_conn *conn = cmd->conn;
918 	int cmdsn_ret = 0, immed_ret = IMMEDIATE_DATA_NORMAL_OPERATION;
919 	/*
920 	 * Special case for Unsupported SAM WRITE Opcodes and ImmediateData=Yes.
921 	 */
922 	if (dump_payload)
923 		goto after_immediate_data;
924 
925 	immed_ret = cxgbit_handle_immediate_data(cmd, hdr,
926 						 cmd->first_burst_len);
927 after_immediate_data:
928 	if (immed_ret == IMMEDIATE_DATA_NORMAL_OPERATION) {
929 		/*
930 		 * A PDU/CmdSN carrying Immediate Data passed
931 		 * DataCRC, check against ExpCmdSN/MaxCmdSN if
932 		 * Immediate Bit is not set.
933 		 */
934 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd,
935 						(unsigned char *)hdr,
936 						hdr->cmdsn);
937 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
938 			return -1;
939 
940 		if (cmd->sense_reason || cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
941 			target_put_sess_cmd(&cmd->se_cmd);
942 			return 0;
943 		} else if (cmd->unsolicited_data) {
944 			iscsit_set_unsolicited_dataout(cmd);
945 		}
946 
947 	} else if (immed_ret == IMMEDIATE_DATA_ERL1_CRC_FAILURE) {
948 		/*
949 		 * Immediate Data failed DataCRC and ERL>=1,
950 		 * silently drop this PDU and let the initiator
951 		 * plug the CmdSN gap.
952 		 *
953 		 * FIXME: Send Unsolicited NOPIN with reserved
954 		 * TTT here to help the initiator figure out
955 		 * the missing CmdSN, although they should be
956 		 * intelligent enough to determine the missing
957 		 * CmdSN and issue a retry to plug the sequence.
958 		 */
959 		cmd->i_state = ISTATE_REMOVE;
960 		iscsit_add_cmd_to_immediate_queue(cmd, conn, cmd->i_state);
961 	} else /* immed_ret == IMMEDIATE_DATA_CANNOT_RECOVER */
962 		return -1;
963 
964 	return 0;
965 }
966 
967 static int
968 cxgbit_handle_scsi_cmd(struct cxgbit_sock *csk, struct iscsi_cmd *cmd)
969 {
970 	struct iscsi_conn *conn = csk->conn;
971 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
972 	struct iscsi_scsi_req *hdr = (struct iscsi_scsi_req *)pdu_cb->hdr;
973 	int rc;
974 	bool dump_payload = false;
975 
976 	rc = iscsit_setup_scsi_cmd(conn, cmd, (unsigned char *)hdr);
977 	if (rc < 0)
978 		return rc;
979 
980 	if (pdu_cb->dlen && (pdu_cb->dlen == cmd->se_cmd.data_length) &&
981 	    (pdu_cb->nr_dfrags == 1))
982 		cmd->se_cmd.se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
983 
984 	rc = iscsit_process_scsi_cmd(conn, cmd, hdr);
985 	if (rc < 0)
986 		return 0;
987 	else if (rc > 0)
988 		dump_payload = true;
989 
990 	if (!pdu_cb->dlen)
991 		return 0;
992 
993 	return cxgbit_get_immediate_data(cmd, hdr, dump_payload);
994 }
995 
996 static int cxgbit_handle_iscsi_dataout(struct cxgbit_sock *csk)
997 {
998 	struct scatterlist *sg_start;
999 	struct iscsi_conn *conn = csk->conn;
1000 	struct iscsi_cmd *cmd = NULL;
1001 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
1002 	struct iscsi_data *hdr = (struct iscsi_data *)pdu_cb->hdr;
1003 	u32 data_offset = be32_to_cpu(hdr->offset);
1004 	u32 data_len = pdu_cb->dlen;
1005 	int rc, sg_nents, sg_off;
1006 	bool dcrc_err = false;
1007 
1008 	if (pdu_cb->flags & PDUCBF_RX_DDP_CMP) {
1009 		u32 offset = be32_to_cpu(hdr->offset);
1010 		u32 ddp_data_len;
1011 		u32 payload_length = ntoh24(hdr->dlength);
1012 		bool success = false;
1013 
1014 		cmd = iscsit_find_cmd_from_itt_or_dump(conn, hdr->itt, 0);
1015 		if (!cmd)
1016 			return 0;
1017 
1018 		ddp_data_len = offset - cmd->write_data_done;
1019 		atomic_long_add(ddp_data_len, &conn->sess->rx_data_octets);
1020 
1021 		cmd->write_data_done = offset;
1022 		cmd->next_burst_len = ddp_data_len;
1023 		cmd->data_sn = be32_to_cpu(hdr->datasn);
1024 
1025 		rc = __iscsit_check_dataout_hdr(conn, (unsigned char *)hdr,
1026 						cmd, payload_length, &success);
1027 		if (rc < 0)
1028 			return rc;
1029 		else if (!success)
1030 			return 0;
1031 	} else {
1032 		rc = iscsit_check_dataout_hdr(conn, (unsigned char *)hdr, &cmd);
1033 		if (rc < 0)
1034 			return rc;
1035 		else if (!cmd)
1036 			return 0;
1037 	}
1038 
1039 	if (pdu_cb->flags & PDUCBF_RX_DCRC_ERR) {
1040 		pr_err("ITT: 0x%08x, Offset: %u, Length: %u,"
1041 		       " DataSN: 0x%08x\n",
1042 		       hdr->itt, hdr->offset, data_len,
1043 		       hdr->datasn);
1044 
1045 		dcrc_err = true;
1046 		goto check_payload;
1047 	}
1048 
1049 	pr_debug("DataOut data_len: %u, "
1050 		"write_data_done: %u, data_length: %u\n",
1051 		  data_len,  cmd->write_data_done,
1052 		  cmd->se_cmd.data_length);
1053 
1054 	if (!(pdu_cb->flags & PDUCBF_RX_DATA_DDPD)) {
1055 		u32 skip = data_offset % PAGE_SIZE;
1056 
1057 		sg_off = data_offset / PAGE_SIZE;
1058 		sg_start = &cmd->se_cmd.t_data_sg[sg_off];
1059 		sg_nents = max(1UL, DIV_ROUND_UP(skip + data_len, PAGE_SIZE));
1060 
1061 		cxgbit_skb_copy_to_sg(csk->skb, sg_start, sg_nents, skip);
1062 	}
1063 
1064 check_payload:
1065 
1066 	rc = iscsit_check_dataout_payload(cmd, hdr, dcrc_err);
1067 	if (rc < 0)
1068 		return rc;
1069 
1070 	return 0;
1071 }
1072 
1073 static int cxgbit_handle_nop_out(struct cxgbit_sock *csk, struct iscsi_cmd *cmd)
1074 {
1075 	struct iscsi_conn *conn = csk->conn;
1076 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
1077 	struct iscsi_nopout *hdr = (struct iscsi_nopout *)pdu_cb->hdr;
1078 	unsigned char *ping_data = NULL;
1079 	u32 payload_length = pdu_cb->dlen;
1080 	int ret;
1081 
1082 	ret = iscsit_setup_nop_out(conn, cmd, hdr);
1083 	if (ret < 0)
1084 		return 0;
1085 
1086 	if (pdu_cb->flags & PDUCBF_RX_DCRC_ERR) {
1087 		if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
1088 			pr_err("Unable to recover from"
1089 			       " NOPOUT Ping DataCRC failure while in"
1090 			       " ERL=0.\n");
1091 			ret = -1;
1092 			goto out;
1093 		} else {
1094 			/*
1095 			 * drop this PDU and let the
1096 			 * initiator plug the CmdSN gap.
1097 			 */
1098 			pr_info("Dropping NOPOUT"
1099 				" Command CmdSN: 0x%08x due to"
1100 				" DataCRC error.\n", hdr->cmdsn);
1101 			ret = 0;
1102 			goto out;
1103 		}
1104 	}
1105 
1106 	/*
1107 	 * Handle NOP-OUT payload for traditional iSCSI sockets
1108 	 */
1109 	if (payload_length && hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
1110 		ping_data = kzalloc(payload_length + 1, GFP_KERNEL);
1111 		if (!ping_data) {
1112 			pr_err("Unable to allocate memory for"
1113 				" NOPOUT ping data.\n");
1114 			ret = -1;
1115 			goto out;
1116 		}
1117 
1118 		skb_copy_bits(csk->skb, pdu_cb->doffset,
1119 			      ping_data, payload_length);
1120 
1121 		ping_data[payload_length] = '\0';
1122 		/*
1123 		 * Attach ping data to struct iscsi_cmd->buf_ptr.
1124 		 */
1125 		cmd->buf_ptr = ping_data;
1126 		cmd->buf_ptr_size = payload_length;
1127 
1128 		pr_debug("Got %u bytes of NOPOUT ping"
1129 			" data.\n", payload_length);
1130 		pr_debug("Ping Data: \"%s\"\n", ping_data);
1131 	}
1132 
1133 	return iscsit_process_nop_out(conn, cmd, hdr);
1134 out:
1135 	if (cmd)
1136 		iscsit_free_cmd(cmd, false);
1137 	return ret;
1138 }
1139 
1140 static int
1141 cxgbit_handle_text_cmd(struct cxgbit_sock *csk, struct iscsi_cmd *cmd)
1142 {
1143 	struct iscsi_conn *conn = csk->conn;
1144 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
1145 	struct iscsi_text *hdr = (struct iscsi_text *)pdu_cb->hdr;
1146 	u32 payload_length = pdu_cb->dlen;
1147 	int rc;
1148 	unsigned char *text_in = NULL;
1149 
1150 	rc = iscsit_setup_text_cmd(conn, cmd, hdr);
1151 	if (rc < 0)
1152 		return rc;
1153 
1154 	if (pdu_cb->flags & PDUCBF_RX_DCRC_ERR) {
1155 		if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
1156 			pr_err("Unable to recover from"
1157 			       " Text Data digest failure while in"
1158 			       " ERL=0.\n");
1159 			goto reject;
1160 		} else {
1161 			/*
1162 			 * drop this PDU and let the
1163 			 * initiator plug the CmdSN gap.
1164 			 */
1165 			pr_info("Dropping Text"
1166 				" Command CmdSN: 0x%08x due to"
1167 				" DataCRC error.\n", hdr->cmdsn);
1168 			return 0;
1169 		}
1170 	}
1171 
1172 	if (payload_length) {
1173 		text_in = kzalloc(payload_length, GFP_KERNEL);
1174 		if (!text_in) {
1175 			pr_err("Unable to allocate text_in of payload_length: %u\n",
1176 			       payload_length);
1177 			return -ENOMEM;
1178 		}
1179 		skb_copy_bits(csk->skb, pdu_cb->doffset,
1180 			      text_in, payload_length);
1181 
1182 		text_in[payload_length - 1] = '\0';
1183 
1184 		cmd->text_in_ptr = text_in;
1185 	}
1186 
1187 	return iscsit_process_text_cmd(conn, cmd, hdr);
1188 
1189 reject:
1190 	return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
1191 				 pdu_cb->hdr);
1192 }
1193 
1194 static int cxgbit_target_rx_opcode(struct cxgbit_sock *csk)
1195 {
1196 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
1197 	struct iscsi_hdr *hdr = (struct iscsi_hdr *)pdu_cb->hdr;
1198 	struct iscsi_conn *conn = csk->conn;
1199 	struct iscsi_cmd *cmd = NULL;
1200 	u8 opcode = (hdr->opcode & ISCSI_OPCODE_MASK);
1201 	int ret = -EINVAL;
1202 
1203 	switch (opcode) {
1204 	case ISCSI_OP_SCSI_CMD:
1205 		cmd = cxgbit_allocate_cmd(csk);
1206 		if (!cmd)
1207 			goto reject;
1208 
1209 		ret = cxgbit_handle_scsi_cmd(csk, cmd);
1210 		break;
1211 	case ISCSI_OP_SCSI_DATA_OUT:
1212 		ret = cxgbit_handle_iscsi_dataout(csk);
1213 		break;
1214 	case ISCSI_OP_NOOP_OUT:
1215 		if (hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
1216 			cmd = cxgbit_allocate_cmd(csk);
1217 			if (!cmd)
1218 				goto reject;
1219 		}
1220 
1221 		ret = cxgbit_handle_nop_out(csk, cmd);
1222 		break;
1223 	case ISCSI_OP_SCSI_TMFUNC:
1224 		cmd = cxgbit_allocate_cmd(csk);
1225 		if (!cmd)
1226 			goto reject;
1227 
1228 		ret = iscsit_handle_task_mgt_cmd(conn, cmd,
1229 						 (unsigned char *)hdr);
1230 		break;
1231 	case ISCSI_OP_TEXT:
1232 		if (hdr->ttt != cpu_to_be32(0xFFFFFFFF)) {
1233 			cmd = iscsit_find_cmd_from_itt(conn, hdr->itt);
1234 			if (!cmd)
1235 				goto reject;
1236 		} else {
1237 			cmd = cxgbit_allocate_cmd(csk);
1238 			if (!cmd)
1239 				goto reject;
1240 		}
1241 
1242 		ret = cxgbit_handle_text_cmd(csk, cmd);
1243 		break;
1244 	case ISCSI_OP_LOGOUT:
1245 		cmd = cxgbit_allocate_cmd(csk);
1246 		if (!cmd)
1247 			goto reject;
1248 
1249 		ret = iscsit_handle_logout_cmd(conn, cmd, (unsigned char *)hdr);
1250 		if (ret > 0)
1251 			wait_for_completion_timeout(&conn->conn_logout_comp,
1252 						    SECONDS_FOR_LOGOUT_COMP
1253 						    * HZ);
1254 		break;
1255 	case ISCSI_OP_SNACK:
1256 		ret = iscsit_handle_snack(conn, (unsigned char *)hdr);
1257 		break;
1258 	default:
1259 		pr_err("Got unknown iSCSI OpCode: 0x%02x\n", opcode);
1260 		dump_stack();
1261 		break;
1262 	}
1263 
1264 	return ret;
1265 
1266 reject:
1267 	return iscsit_add_reject(conn, ISCSI_REASON_BOOKMARK_NO_RESOURCES,
1268 				 (unsigned char *)hdr);
1269 	return ret;
1270 }
1271 
1272 static int cxgbit_rx_opcode(struct cxgbit_sock *csk)
1273 {
1274 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
1275 	struct iscsi_conn *conn = csk->conn;
1276 	struct iscsi_hdr *hdr = pdu_cb->hdr;
1277 	u8 opcode;
1278 
1279 	if (pdu_cb->flags & PDUCBF_RX_HCRC_ERR) {
1280 		atomic_long_inc(&conn->sess->conn_digest_errors);
1281 		goto transport_err;
1282 	}
1283 
1284 	if (conn->conn_state == TARG_CONN_STATE_IN_LOGOUT)
1285 		goto transport_err;
1286 
1287 	opcode = hdr->opcode & ISCSI_OPCODE_MASK;
1288 
1289 	if (conn->sess->sess_ops->SessionType &&
1290 	    ((!(opcode & ISCSI_OP_TEXT)) ||
1291 	     (!(opcode & ISCSI_OP_LOGOUT)))) {
1292 		pr_err("Received illegal iSCSI Opcode: 0x%02x"
1293 			" while in Discovery Session, rejecting.\n", opcode);
1294 		iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1295 				  (unsigned char *)hdr);
1296 		goto transport_err;
1297 	}
1298 
1299 	if (cxgbit_target_rx_opcode(csk) < 0)
1300 		goto transport_err;
1301 
1302 	return 0;
1303 
1304 transport_err:
1305 	return -1;
1306 }
1307 
1308 static int cxgbit_rx_login_pdu(struct cxgbit_sock *csk)
1309 {
1310 	struct iscsi_conn *conn = csk->conn;
1311 	struct iscsi_login *login = conn->login;
1312 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_rx_pdu_cb(csk->skb);
1313 	struct iscsi_login_req *login_req;
1314 
1315 	login_req = (struct iscsi_login_req *)login->req;
1316 	memcpy(login_req, pdu_cb->hdr, sizeof(*login_req));
1317 
1318 	pr_debug("Got Login Command, Flags 0x%02x, ITT: 0x%08x,"
1319 		" CmdSN: 0x%08x, ExpStatSN: 0x%08x, CID: %hu, Length: %u\n",
1320 		login_req->flags, login_req->itt, login_req->cmdsn,
1321 		login_req->exp_statsn, login_req->cid, pdu_cb->dlen);
1322 	/*
1323 	 * Setup the initial iscsi_login values from the leading
1324 	 * login request PDU.
1325 	 */
1326 	if (login->first_request) {
1327 		login_req = (struct iscsi_login_req *)login->req;
1328 		login->leading_connection = (!login_req->tsih) ? 1 : 0;
1329 		login->current_stage	= ISCSI_LOGIN_CURRENT_STAGE(
1330 				login_req->flags);
1331 		login->version_min	= login_req->min_version;
1332 		login->version_max	= login_req->max_version;
1333 		memcpy(login->isid, login_req->isid, 6);
1334 		login->cmd_sn		= be32_to_cpu(login_req->cmdsn);
1335 		login->init_task_tag	= login_req->itt;
1336 		login->initial_exp_statsn = be32_to_cpu(login_req->exp_statsn);
1337 		login->cid		= be16_to_cpu(login_req->cid);
1338 		login->tsih		= be16_to_cpu(login_req->tsih);
1339 	}
1340 
1341 	if (iscsi_target_check_login_request(conn, login) < 0)
1342 		return -1;
1343 
1344 	memset(login->req_buf, 0, MAX_KEY_VALUE_PAIRS);
1345 	skb_copy_bits(csk->skb, pdu_cb->doffset, login->req_buf, pdu_cb->dlen);
1346 
1347 	return 0;
1348 }
1349 
1350 static int
1351 cxgbit_process_iscsi_pdu(struct cxgbit_sock *csk, struct sk_buff *skb, int idx)
1352 {
1353 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_skb_lro_pdu_cb(skb, idx);
1354 	int ret;
1355 
1356 	cxgbit_rx_pdu_cb(skb) = pdu_cb;
1357 
1358 	csk->skb = skb;
1359 
1360 	if (!test_bit(CSK_LOGIN_DONE, &csk->com.flags)) {
1361 		ret = cxgbit_rx_login_pdu(csk);
1362 		set_bit(CSK_LOGIN_PDU_DONE, &csk->com.flags);
1363 	} else {
1364 		ret = cxgbit_rx_opcode(csk);
1365 	}
1366 
1367 	return ret;
1368 }
1369 
1370 static void cxgbit_lro_skb_dump(struct sk_buff *skb)
1371 {
1372 	struct skb_shared_info *ssi = skb_shinfo(skb);
1373 	struct cxgbit_lro_cb *lro_cb = cxgbit_skb_lro_cb(skb);
1374 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_skb_lro_pdu_cb(skb, 0);
1375 	u8 i;
1376 
1377 	pr_info("skb 0x%p, head 0x%p, 0x%p, len %u,%u, frags %u.\n",
1378 		skb, skb->head, skb->data, skb->len, skb->data_len,
1379 		ssi->nr_frags);
1380 	pr_info("skb 0x%p, lro_cb, csk 0x%p, pdu %u, %u.\n",
1381 		skb, lro_cb->csk, lro_cb->pdu_idx, lro_cb->pdu_totallen);
1382 
1383 	for (i = 0; i < lro_cb->pdu_idx; i++, pdu_cb++)
1384 		pr_info("skb 0x%p, pdu %d, %u, f 0x%x, seq 0x%x, dcrc 0x%x, "
1385 			"frags %u.\n",
1386 			skb, i, pdu_cb->pdulen, pdu_cb->flags, pdu_cb->seq,
1387 			pdu_cb->ddigest, pdu_cb->frags);
1388 	for (i = 0; i < ssi->nr_frags; i++)
1389 		pr_info("skb 0x%p, frag %d, off %u, sz %u.\n",
1390 			skb, i, skb_frag_off(&ssi->frags[i]),
1391 			skb_frag_size(&ssi->frags[i]));
1392 }
1393 
1394 static void cxgbit_lro_hskb_reset(struct cxgbit_sock *csk)
1395 {
1396 	struct sk_buff *skb = csk->lro_hskb;
1397 	struct skb_shared_info *ssi = skb_shinfo(skb);
1398 	u8 i;
1399 
1400 	memset(skb->data, 0, LRO_SKB_MIN_HEADROOM);
1401 	for (i = 0; i < ssi->nr_frags; i++)
1402 		put_page(skb_frag_page(&ssi->frags[i]));
1403 	ssi->nr_frags = 0;
1404 	skb->data_len = 0;
1405 	skb->truesize -= skb->len;
1406 	skb->len = 0;
1407 }
1408 
1409 static void
1410 cxgbit_lro_skb_merge(struct cxgbit_sock *csk, struct sk_buff *skb, u8 pdu_idx)
1411 {
1412 	struct sk_buff *hskb = csk->lro_hskb;
1413 	struct cxgbit_lro_pdu_cb *hpdu_cb = cxgbit_skb_lro_pdu_cb(hskb, 0);
1414 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_skb_lro_pdu_cb(skb, pdu_idx);
1415 	struct skb_shared_info *hssi = skb_shinfo(hskb);
1416 	struct skb_shared_info *ssi = skb_shinfo(skb);
1417 	unsigned int len = 0;
1418 
1419 	if (pdu_cb->flags & PDUCBF_RX_HDR) {
1420 		u8 hfrag_idx = hssi->nr_frags;
1421 
1422 		hpdu_cb->flags |= pdu_cb->flags;
1423 		hpdu_cb->seq = pdu_cb->seq;
1424 		hpdu_cb->hdr = pdu_cb->hdr;
1425 		hpdu_cb->hlen = pdu_cb->hlen;
1426 
1427 		memcpy(&hssi->frags[hfrag_idx], &ssi->frags[pdu_cb->hfrag_idx],
1428 		       sizeof(skb_frag_t));
1429 
1430 		get_page(skb_frag_page(&hssi->frags[hfrag_idx]));
1431 		hssi->nr_frags++;
1432 		hpdu_cb->frags++;
1433 		hpdu_cb->hfrag_idx = hfrag_idx;
1434 
1435 		len = skb_frag_size(&hssi->frags[hfrag_idx]);
1436 		hskb->len += len;
1437 		hskb->data_len += len;
1438 		hskb->truesize += len;
1439 	}
1440 
1441 	if (pdu_cb->flags & PDUCBF_RX_DATA) {
1442 		u8 dfrag_idx = hssi->nr_frags, i;
1443 
1444 		hpdu_cb->flags |= pdu_cb->flags;
1445 		hpdu_cb->dfrag_idx = dfrag_idx;
1446 
1447 		len = 0;
1448 		for (i = 0; i < pdu_cb->nr_dfrags; dfrag_idx++, i++) {
1449 			memcpy(&hssi->frags[dfrag_idx],
1450 			       &ssi->frags[pdu_cb->dfrag_idx + i],
1451 			       sizeof(skb_frag_t));
1452 
1453 			get_page(skb_frag_page(&hssi->frags[dfrag_idx]));
1454 
1455 			len += skb_frag_size(&hssi->frags[dfrag_idx]);
1456 
1457 			hssi->nr_frags++;
1458 			hpdu_cb->frags++;
1459 		}
1460 
1461 		hpdu_cb->dlen = pdu_cb->dlen;
1462 		hpdu_cb->doffset = hpdu_cb->hlen;
1463 		hpdu_cb->nr_dfrags = pdu_cb->nr_dfrags;
1464 		hskb->len += len;
1465 		hskb->data_len += len;
1466 		hskb->truesize += len;
1467 	}
1468 
1469 	if (pdu_cb->flags & PDUCBF_RX_STATUS) {
1470 		hpdu_cb->flags |= pdu_cb->flags;
1471 
1472 		if (hpdu_cb->flags & PDUCBF_RX_DATA)
1473 			hpdu_cb->flags &= ~PDUCBF_RX_DATA_DDPD;
1474 
1475 		hpdu_cb->ddigest = pdu_cb->ddigest;
1476 		hpdu_cb->pdulen = pdu_cb->pdulen;
1477 	}
1478 }
1479 
1480 static int cxgbit_process_lro_skb(struct cxgbit_sock *csk, struct sk_buff *skb)
1481 {
1482 	struct cxgbit_lro_cb *lro_cb = cxgbit_skb_lro_cb(skb);
1483 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_skb_lro_pdu_cb(skb, 0);
1484 	u8 pdu_idx = 0, last_idx = 0;
1485 	int ret = 0;
1486 
1487 	if (!pdu_cb->complete) {
1488 		cxgbit_lro_skb_merge(csk, skb, 0);
1489 
1490 		if (pdu_cb->flags & PDUCBF_RX_STATUS) {
1491 			struct sk_buff *hskb = csk->lro_hskb;
1492 
1493 			ret = cxgbit_process_iscsi_pdu(csk, hskb, 0);
1494 
1495 			cxgbit_lro_hskb_reset(csk);
1496 
1497 			if (ret < 0)
1498 				goto out;
1499 		}
1500 
1501 		pdu_idx = 1;
1502 	}
1503 
1504 	if (lro_cb->pdu_idx)
1505 		last_idx = lro_cb->pdu_idx - 1;
1506 
1507 	for (; pdu_idx <= last_idx; pdu_idx++) {
1508 		ret = cxgbit_process_iscsi_pdu(csk, skb, pdu_idx);
1509 		if (ret < 0)
1510 			goto out;
1511 	}
1512 
1513 	if ((!lro_cb->complete) && lro_cb->pdu_idx)
1514 		cxgbit_lro_skb_merge(csk, skb, lro_cb->pdu_idx);
1515 
1516 out:
1517 	return ret;
1518 }
1519 
1520 static int cxgbit_rx_lro_skb(struct cxgbit_sock *csk, struct sk_buff *skb)
1521 {
1522 	struct cxgbit_lro_cb *lro_cb = cxgbit_skb_lro_cb(skb);
1523 	struct cxgbit_lro_pdu_cb *pdu_cb = cxgbit_skb_lro_pdu_cb(skb, 0);
1524 	int ret = -1;
1525 
1526 	if ((pdu_cb->flags & PDUCBF_RX_HDR) &&
1527 	    (pdu_cb->seq != csk->rcv_nxt)) {
1528 		pr_info("csk 0x%p, tid 0x%x, seq 0x%x != 0x%x.\n",
1529 			csk, csk->tid, pdu_cb->seq, csk->rcv_nxt);
1530 		cxgbit_lro_skb_dump(skb);
1531 		return ret;
1532 	}
1533 
1534 	csk->rcv_nxt += lro_cb->pdu_totallen;
1535 
1536 	ret = cxgbit_process_lro_skb(csk, skb);
1537 
1538 	csk->rx_credits += lro_cb->pdu_totallen;
1539 
1540 	if (csk->rx_credits >= (csk->rcv_win / 4))
1541 		cxgbit_rx_data_ack(csk);
1542 
1543 	return ret;
1544 }
1545 
1546 static int cxgbit_rx_skb(struct cxgbit_sock *csk, struct sk_buff *skb)
1547 {
1548 	struct cxgb4_lld_info *lldi = &csk->com.cdev->lldi;
1549 	int ret = -1;
1550 
1551 	if (likely(cxgbit_skcb_flags(skb) & SKCBF_RX_LRO)) {
1552 		if (is_t5(lldi->adapter_type))
1553 			ret = cxgbit_rx_lro_skb(csk, skb);
1554 		else
1555 			ret = cxgbit_process_lro_skb(csk, skb);
1556 	}
1557 
1558 	__kfree_skb(skb);
1559 	return ret;
1560 }
1561 
1562 static bool cxgbit_rxq_len(struct cxgbit_sock *csk, struct sk_buff_head *rxq)
1563 {
1564 	spin_lock_bh(&csk->rxq.lock);
1565 	if (skb_queue_len(&csk->rxq)) {
1566 		skb_queue_splice_init(&csk->rxq, rxq);
1567 		spin_unlock_bh(&csk->rxq.lock);
1568 		return true;
1569 	}
1570 	spin_unlock_bh(&csk->rxq.lock);
1571 	return false;
1572 }
1573 
1574 static int cxgbit_wait_rxq(struct cxgbit_sock *csk)
1575 {
1576 	struct sk_buff *skb;
1577 	struct sk_buff_head rxq;
1578 
1579 	skb_queue_head_init(&rxq);
1580 
1581 	wait_event_interruptible(csk->waitq, cxgbit_rxq_len(csk, &rxq));
1582 
1583 	if (signal_pending(current))
1584 		goto out;
1585 
1586 	while ((skb = __skb_dequeue(&rxq))) {
1587 		if (cxgbit_rx_skb(csk, skb))
1588 			goto out;
1589 	}
1590 
1591 	return 0;
1592 out:
1593 	__skb_queue_purge(&rxq);
1594 	return -1;
1595 }
1596 
1597 int cxgbit_get_login_rx(struct iscsi_conn *conn, struct iscsi_login *login)
1598 {
1599 	struct cxgbit_sock *csk = conn->context;
1600 	int ret = -1;
1601 
1602 	while (!test_and_clear_bit(CSK_LOGIN_PDU_DONE, &csk->com.flags)) {
1603 		ret = cxgbit_wait_rxq(csk);
1604 		if (ret) {
1605 			clear_bit(CSK_LOGIN_PDU_DONE, &csk->com.flags);
1606 			break;
1607 		}
1608 	}
1609 
1610 	return ret;
1611 }
1612 
1613 void cxgbit_get_rx_pdu(struct iscsi_conn *conn)
1614 {
1615 	struct cxgbit_sock *csk = conn->context;
1616 
1617 	while (!kthread_should_stop()) {
1618 		iscsit_thread_check_cpumask(conn, current, 0);
1619 		if (cxgbit_wait_rxq(csk))
1620 			return;
1621 	}
1622 }
1623