xref: /dpdk/drivers/net/mlx4/mlx4_rxtx.c (revision 68a03efeed657e6e05f281479b33b51102797e15)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright 2017 6WIND S.A.
3  * Copyright 2017 Mellanox Technologies, Ltd
4  */
5 
6 /**
7  * @file
8  * Data plane functions for mlx4 driver.
9  */
10 
11 #include <stdbool.h>
12 #include <stdint.h>
13 #include <string.h>
14 
15 /* Verbs headers do not support -pedantic. */
16 #ifdef PEDANTIC
17 #pragma GCC diagnostic ignored "-Wpedantic"
18 #endif
19 #include <infiniband/verbs.h>
20 #ifdef PEDANTIC
21 #pragma GCC diagnostic error "-Wpedantic"
22 #endif
23 
24 #include <rte_branch_prediction.h>
25 #include <rte_common.h>
26 #include <rte_io.h>
27 #include <rte_mbuf.h>
28 #include <rte_mempool.h>
29 #include <rte_prefetch.h>
30 
31 #include "mlx4.h"
32 #include "mlx4_prm.h"
33 #include "mlx4_rxtx.h"
34 #include "mlx4_utils.h"
35 
36 /**
37  * Pointer-value pair structure used in tx_post_send for saving the first
38  * DWORD (32 byte) of a TXBB.
39  */
40 struct pv {
41 	union {
42 		volatile struct mlx4_wqe_data_seg *dseg;
43 		volatile uint32_t *dst;
44 	};
45 	uint32_t val;
46 };
47 
48 /** A helper structure for TSO packet handling. */
49 struct tso_info {
50 	/** Pointer to the array of saved first DWORD (32 byte) of a TXBB. */
51 	struct pv *pv;
52 	/** Current entry in the pv array. */
53 	int pv_counter;
54 	/** Total size of the WQE including padding. */
55 	uint32_t wqe_size;
56 	/** Size of TSO header to prepend to each packet to send. */
57 	uint16_t tso_header_size;
58 	/** Total size of the TSO segment in the WQE. */
59 	uint16_t wqe_tso_seg_size;
60 	/** Raw WQE size in units of 16 Bytes and without padding. */
61 	uint8_t fence_size;
62 };
63 
64 /** A table to translate Rx completion flags to packet type. */
65 uint32_t mlx4_ptype_table[0x100] __rte_cache_aligned = {
66 	/*
67 	 * The index to the array should have:
68 	 *  bit[7] - MLX4_CQE_L2_TUNNEL
69 	 *  bit[6] - MLX4_CQE_L2_TUNNEL_IPV4
70 	 *  bit[5] - MLX4_CQE_STATUS_UDP
71 	 *  bit[4] - MLX4_CQE_STATUS_TCP
72 	 *  bit[3] - MLX4_CQE_STATUS_IPV4OPT
73 	 *  bit[2] - MLX4_CQE_STATUS_IPV6
74 	 *  bit[1] - MLX4_CQE_STATUS_IPF
75 	 *  bit[0] - MLX4_CQE_STATUS_IPV4
76 	 * giving a total of up to 256 entries.
77 	 */
78 	/* L2 */
79 	[0x00] = RTE_PTYPE_L2_ETHER,
80 	/* L3 */
81 	[0x01] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
82 		     RTE_PTYPE_L4_NONFRAG,
83 	[0x02] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
84 		     RTE_PTYPE_L4_FRAG,
85 	[0x03] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
86 		     RTE_PTYPE_L4_FRAG,
87 	[0x04] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
88 		     RTE_PTYPE_L4_NONFRAG,
89 	[0x06] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
90 		     RTE_PTYPE_L4_FRAG,
91 	[0x08] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT |
92 		     RTE_PTYPE_L4_NONFRAG,
93 	[0x09] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT |
94 		     RTE_PTYPE_L4_NONFRAG,
95 	[0x0a] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT |
96 		     RTE_PTYPE_L4_FRAG,
97 	[0x0b] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT |
98 		     RTE_PTYPE_L4_FRAG,
99 	/* TCP */
100 	[0x11] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
101 		     RTE_PTYPE_L4_TCP,
102 	[0x14] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
103 		     RTE_PTYPE_L4_TCP,
104 	[0x16] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
105 		     RTE_PTYPE_L4_FRAG,
106 	[0x18] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT |
107 		     RTE_PTYPE_L4_TCP,
108 	[0x19] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT |
109 		     RTE_PTYPE_L4_TCP,
110 	/* UDP */
111 	[0x21] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
112 		     RTE_PTYPE_L4_UDP,
113 	[0x24] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
114 		     RTE_PTYPE_L4_UDP,
115 	[0x26] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
116 		     RTE_PTYPE_L4_FRAG,
117 	[0x28] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT |
118 		     RTE_PTYPE_L4_UDP,
119 	[0x29] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT |
120 		     RTE_PTYPE_L4_UDP,
121 	/* Tunneled - L3 IPV6 */
122 	[0x80] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN,
123 	[0x81] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
124 		     RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN |
125 		     RTE_PTYPE_INNER_L4_NONFRAG,
126 	[0x82] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
127 		     RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN |
128 		     RTE_PTYPE_INNER_L4_FRAG,
129 	[0x83] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
130 		     RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN |
131 		     RTE_PTYPE_INNER_L4_FRAG,
132 	[0x84] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
133 		     RTE_PTYPE_INNER_L3_IPV6_EXT_UNKNOWN |
134 		     RTE_PTYPE_INNER_L4_NONFRAG,
135 	[0x86] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
136 		     RTE_PTYPE_INNER_L3_IPV6_EXT_UNKNOWN |
137 		     RTE_PTYPE_INNER_L4_FRAG,
138 	[0x88] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
139 		     RTE_PTYPE_INNER_L3_IPV4_EXT |
140 		     RTE_PTYPE_INNER_L4_NONFRAG,
141 	[0x89] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
142 		     RTE_PTYPE_INNER_L3_IPV4_EXT |
143 		     RTE_PTYPE_INNER_L4_NONFRAG,
144 	[0x8a] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
145 		     RTE_PTYPE_INNER_L3_IPV4_EXT |
146 		     RTE_PTYPE_INNER_L4_FRAG,
147 	[0x8b] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
148 		     RTE_PTYPE_INNER_L3_IPV4_EXT |
149 		     RTE_PTYPE_INNER_L4_FRAG,
150 	/* Tunneled - L3 IPV6, TCP */
151 	[0x91] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
152 		     RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN |
153 		     RTE_PTYPE_INNER_L4_TCP,
154 	[0x94] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
155 		     RTE_PTYPE_INNER_L3_IPV6_EXT_UNKNOWN |
156 		     RTE_PTYPE_INNER_L4_TCP,
157 	[0x96] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
158 		     RTE_PTYPE_INNER_L3_IPV6_EXT_UNKNOWN |
159 		     RTE_PTYPE_INNER_L4_FRAG,
160 	[0x98] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
161 		     RTE_PTYPE_INNER_L3_IPV4_EXT | RTE_PTYPE_INNER_L4_TCP,
162 	[0x99] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
163 		     RTE_PTYPE_INNER_L3_IPV4_EXT | RTE_PTYPE_INNER_L4_TCP,
164 	/* Tunneled - L3 IPV6, UDP */
165 	[0xa1] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
166 		     RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN |
167 		     RTE_PTYPE_INNER_L4_UDP,
168 	[0xa4] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
169 		     RTE_PTYPE_INNER_L3_IPV6_EXT_UNKNOWN |
170 		     RTE_PTYPE_INNER_L4_UDP,
171 	[0xa6] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
172 		     RTE_PTYPE_INNER_L3_IPV6_EXT_UNKNOWN |
173 		     RTE_PTYPE_INNER_L4_FRAG,
174 	[0xa8] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
175 		     RTE_PTYPE_INNER_L3_IPV4_EXT |
176 		     RTE_PTYPE_INNER_L4_UDP,
177 	[0xa9] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
178 		     RTE_PTYPE_INNER_L3_IPV4_EXT |
179 		     RTE_PTYPE_INNER_L4_UDP,
180 	/* Tunneled - L3 IPV4 */
181 	[0xc0] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN,
182 	[0xc1] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
183 		     RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN |
184 		     RTE_PTYPE_INNER_L4_NONFRAG,
185 	[0xc2] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
186 		     RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN |
187 		     RTE_PTYPE_INNER_L4_FRAG,
188 	[0xc3] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
189 		     RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN |
190 		     RTE_PTYPE_INNER_L4_FRAG,
191 	[0xc4] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
192 		     RTE_PTYPE_INNER_L3_IPV6_EXT_UNKNOWN |
193 		     RTE_PTYPE_INNER_L4_NONFRAG,
194 	[0xc6] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
195 		     RTE_PTYPE_INNER_L3_IPV6_EXT_UNKNOWN |
196 		     RTE_PTYPE_INNER_L4_FRAG,
197 	[0xc8] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
198 		     RTE_PTYPE_INNER_L3_IPV4_EXT |
199 		     RTE_PTYPE_INNER_L4_NONFRAG,
200 	[0xc9] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
201 		     RTE_PTYPE_INNER_L3_IPV4_EXT |
202 		     RTE_PTYPE_INNER_L4_NONFRAG,
203 	[0xca] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
204 		     RTE_PTYPE_INNER_L3_IPV4_EXT |
205 		     RTE_PTYPE_INNER_L4_FRAG,
206 	[0xcb] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
207 		     RTE_PTYPE_INNER_L3_IPV4_EXT |
208 		     RTE_PTYPE_INNER_L4_FRAG,
209 	/* Tunneled - L3 IPV4, TCP */
210 	[0xd1] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
211 		     RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN |
212 		     RTE_PTYPE_INNER_L4_TCP,
213 	[0xd4] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
214 		     RTE_PTYPE_INNER_L3_IPV6_EXT_UNKNOWN |
215 		     RTE_PTYPE_INNER_L4_TCP,
216 	[0xd6] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
217 		     RTE_PTYPE_INNER_L3_IPV6_EXT_UNKNOWN |
218 		     RTE_PTYPE_INNER_L4_FRAG,
219 	[0xd8] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
220 		     RTE_PTYPE_INNER_L3_IPV4_EXT |
221 		     RTE_PTYPE_INNER_L4_TCP,
222 	[0xd9] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
223 		     RTE_PTYPE_INNER_L3_IPV4_EXT |
224 		     RTE_PTYPE_INNER_L4_TCP,
225 	/* Tunneled - L3 IPV4, UDP */
226 	[0xe1] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
227 		     RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN |
228 		     RTE_PTYPE_INNER_L4_UDP,
229 	[0xe4] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
230 		     RTE_PTYPE_INNER_L3_IPV6_EXT_UNKNOWN |
231 		     RTE_PTYPE_INNER_L4_UDP,
232 	[0xe6] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
233 		     RTE_PTYPE_INNER_L3_IPV6_EXT_UNKNOWN |
234 		     RTE_PTYPE_INNER_L4_FRAG,
235 	[0xe8] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
236 		     RTE_PTYPE_INNER_L3_IPV4_EXT |
237 		     RTE_PTYPE_INNER_L4_UDP,
238 	[0xe9] = RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
239 		     RTE_PTYPE_INNER_L3_IPV4_EXT |
240 		     RTE_PTYPE_INNER_L4_UDP,
241 };
242 
243 /**
244  * Stamp TXBB burst so it won't be reused by the HW.
245  *
246  * Routine is used when freeing WQE used by the chip or when failing
247  * building an WQ entry has failed leaving partial information on the queue.
248  *
249  * @param sq
250  *   Pointer to the SQ structure.
251  * @param start
252  *   Pointer to the first TXBB to stamp.
253  * @param end
254  *   Pointer to the followed end TXBB to stamp.
255  *
256  * @return
257  *   Stamping burst size in byte units.
258  */
259 static uint32_t
260 mlx4_txq_stamp_freed_wqe(struct mlx4_sq *sq, volatile uint32_t *start,
261 			 volatile uint32_t *end)
262 {
263 	uint32_t stamp = sq->stamp;
264 	int32_t size = (intptr_t)end - (intptr_t)start;
265 
266 	MLX4_ASSERT(start != end);
267 	/* Hold SQ ring wrap around. */
268 	if (size < 0) {
269 		size = (int32_t)sq->size + size;
270 		do {
271 			*start = stamp;
272 			start += MLX4_SQ_STAMP_DWORDS;
273 		} while (start != (volatile uint32_t *)sq->eob);
274 		start = (volatile uint32_t *)sq->buf;
275 		/* Flip invalid stamping ownership. */
276 		stamp ^= RTE_BE32(1u << MLX4_SQ_OWNER_BIT);
277 		sq->stamp = stamp;
278 		if (start == end)
279 			return size;
280 	}
281 	do {
282 		*start = stamp;
283 		start += MLX4_SQ_STAMP_DWORDS;
284 	} while (start != end);
285 	return (uint32_t)size;
286 }
287 
288 /**
289  * Manage Tx completions.
290  *
291  * When sending a burst, mlx4_tx_burst() posts several WRs.
292  * To improve performance, a completion event is only required once every
293  * MLX4_PMD_TX_PER_COMP_REQ sends. Doing so discards completion information
294  * for other WRs, but this information would not be used anyway.
295  *
296  * @param txq
297  *   Pointer to Tx queue structure.
298  * @param elts_m
299  *   Tx elements number mask.
300  * @param sq
301  *   Pointer to the SQ structure.
302  */
303 static void
304 mlx4_txq_complete(struct txq *txq, const unsigned int elts_m,
305 		  struct mlx4_sq *sq)
306 {
307 	unsigned int elts_tail = txq->elts_tail;
308 	struct mlx4_cq *cq = &txq->mcq;
309 	volatile struct mlx4_cqe *cqe;
310 	uint32_t completed;
311 	uint32_t cons_index = cq->cons_index;
312 	volatile uint32_t *first_txbb;
313 
314 	/*
315 	 * Traverse over all CQ entries reported and handle each WQ entry
316 	 * reported by them.
317 	 */
318 	do {
319 		cqe = (volatile struct mlx4_cqe *)mlx4_get_cqe(cq, cons_index);
320 		if (unlikely(!!(cqe->owner_sr_opcode & MLX4_CQE_OWNER_MASK) ^
321 		    !!(cons_index & cq->cqe_cnt)))
322 			break;
323 #ifdef RTE_LIBRTE_MLX4_DEBUG
324 		/*
325 		 * Make sure we read the CQE after we read the ownership bit.
326 		 */
327 		rte_io_rmb();
328 		if (unlikely((cqe->owner_sr_opcode & MLX4_CQE_OPCODE_MASK) ==
329 			     MLX4_CQE_OPCODE_ERROR)) {
330 			volatile struct mlx4_err_cqe *cqe_err =
331 				(volatile struct mlx4_err_cqe *)cqe;
332 			ERROR("%p CQE error - vendor syndrome: 0x%x"
333 			      " syndrome: 0x%x\n",
334 			      (void *)txq, cqe_err->vendor_err,
335 			      cqe_err->syndrome);
336 			break;
337 		}
338 #endif /* RTE_LIBRTE_MLX4_DEBUG */
339 		cons_index++;
340 	} while (1);
341 	completed = (cons_index - cq->cons_index) * txq->elts_comp_cd_init;
342 	if (unlikely(!completed))
343 		return;
344 	/* First stamping address is the end of the last one. */
345 	first_txbb = (&(*txq->elts)[elts_tail & elts_m])->eocb;
346 	elts_tail += completed;
347 	/* The new tail element holds the end address. */
348 	sq->remain_size += mlx4_txq_stamp_freed_wqe(sq, first_txbb,
349 		(&(*txq->elts)[elts_tail & elts_m])->eocb);
350 	/* Update CQ consumer index. */
351 	cq->cons_index = cons_index;
352 	*cq->set_ci_db = rte_cpu_to_be_32(cons_index & MLX4_CQ_DB_CI_MASK);
353 	txq->elts_tail = elts_tail;
354 }
355 
356 /**
357  * Write Tx data segment to the SQ.
358  *
359  * @param dseg
360  *   Pointer to data segment in SQ.
361  * @param lkey
362  *   Memory region lkey.
363  * @param addr
364  *   Data address.
365  * @param byte_count
366  *   Big endian bytes count of the data to send.
367  */
368 static inline void
369 mlx4_fill_tx_data_seg(volatile struct mlx4_wqe_data_seg *dseg,
370 		       uint32_t lkey, uintptr_t addr, rte_be32_t  byte_count)
371 {
372 	dseg->addr = rte_cpu_to_be_64(addr);
373 	dseg->lkey = lkey;
374 #if RTE_CACHE_LINE_SIZE < 64
375 	/*
376 	 * Need a barrier here before writing the byte_count
377 	 * fields to make sure that all the data is visible
378 	 * before the byte_count field is set.
379 	 * Otherwise, if the segment begins a new cacheline,
380 	 * the HCA prefetcher could grab the 64-byte chunk and
381 	 * get a valid (!= 0xffffffff) byte count but stale
382 	 * data, and end up sending the wrong data.
383 	 */
384 	rte_io_wmb();
385 #endif /* RTE_CACHE_LINE_SIZE */
386 	dseg->byte_count = byte_count;
387 }
388 
389 /**
390  * Obtain and calculate TSO information needed for assembling a TSO WQE.
391  *
392  * @param buf
393  *   Pointer to the first packet mbuf.
394  * @param txq
395  *   Pointer to Tx queue structure.
396  * @param tinfo
397  *   Pointer to a structure to fill the info with.
398  *
399  * @return
400  *   0 on success, negative value upon error.
401  */
402 static inline int
403 mlx4_tx_burst_tso_get_params(struct rte_mbuf *buf,
404 			     struct txq *txq,
405 			     struct tso_info *tinfo)
406 {
407 	struct mlx4_sq *sq = &txq->msq;
408 	const uint8_t tunneled = txq->priv->hw_csum_l2tun &&
409 				 (buf->ol_flags & PKT_TX_TUNNEL_MASK);
410 
411 	tinfo->tso_header_size = buf->l2_len + buf->l3_len + buf->l4_len;
412 	if (tunneled)
413 		tinfo->tso_header_size +=
414 				buf->outer_l2_len + buf->outer_l3_len;
415 	if (unlikely(buf->tso_segsz == 0 ||
416 		     tinfo->tso_header_size == 0 ||
417 		     tinfo->tso_header_size > MLX4_MAX_TSO_HEADER ||
418 		     tinfo->tso_header_size > buf->data_len))
419 		return -EINVAL;
420 	/*
421 	 * Calculate the WQE TSO segment size
422 	 * Note:
423 	 * 1. An LSO segment must be padded such that the subsequent data
424 	 *    segment is 16-byte aligned.
425 	 * 2. The start address of the TSO segment is always 16 Bytes aligned.
426 	 */
427 	tinfo->wqe_tso_seg_size = RTE_ALIGN(sizeof(struct mlx4_wqe_lso_seg) +
428 					    tinfo->tso_header_size,
429 					    sizeof(struct mlx4_wqe_data_seg));
430 	tinfo->fence_size = ((sizeof(struct mlx4_wqe_ctrl_seg) +
431 			     tinfo->wqe_tso_seg_size) >> MLX4_SEG_SHIFT) +
432 			     buf->nb_segs;
433 	tinfo->wqe_size =
434 		RTE_ALIGN((uint32_t)(tinfo->fence_size << MLX4_SEG_SHIFT),
435 			  MLX4_TXBB_SIZE);
436 	/* Validate WQE size and WQE space in the send queue. */
437 	if (sq->remain_size < tinfo->wqe_size ||
438 	    tinfo->wqe_size > MLX4_MAX_WQE_SIZE)
439 		return -ENOMEM;
440 	/* Init pv. */
441 	tinfo->pv = (struct pv *)txq->bounce_buf;
442 	tinfo->pv_counter = 0;
443 	return 0;
444 }
445 
446 /**
447  * Fill the TSO WQE data segments with info on buffers to transmit .
448  *
449  * @param buf
450  *   Pointer to the first packet mbuf.
451  * @param txq
452  *   Pointer to Tx queue structure.
453  * @param tinfo
454  *   Pointer to TSO info to use.
455  * @param dseg
456  *   Pointer to the first data segment in the TSO WQE.
457  * @param ctrl
458  *   Pointer to the control segment in the TSO WQE.
459  *
460  * @return
461  *   0 on success, negative value upon error.
462  */
463 static inline volatile struct mlx4_wqe_ctrl_seg *
464 mlx4_tx_burst_fill_tso_dsegs(struct rte_mbuf *buf,
465 			     struct txq *txq,
466 			     struct tso_info *tinfo,
467 			     volatile struct mlx4_wqe_data_seg *dseg,
468 			     volatile struct mlx4_wqe_ctrl_seg *ctrl)
469 {
470 	uint32_t lkey;
471 	int nb_segs = buf->nb_segs;
472 	int nb_segs_txbb;
473 	struct mlx4_sq *sq = &txq->msq;
474 	struct rte_mbuf *sbuf = buf;
475 	struct pv *pv = tinfo->pv;
476 	int *pv_counter = &tinfo->pv_counter;
477 	volatile struct mlx4_wqe_ctrl_seg *ctrl_next =
478 			(volatile struct mlx4_wqe_ctrl_seg *)
479 				((volatile uint8_t *)ctrl + tinfo->wqe_size);
480 	uint16_t data_len = sbuf->data_len - tinfo->tso_header_size;
481 	uintptr_t data_addr = rte_pktmbuf_mtod_offset(sbuf, uintptr_t,
482 						      tinfo->tso_header_size);
483 
484 	do {
485 		/* how many dseg entries do we have in the current TXBB ? */
486 		nb_segs_txbb = (MLX4_TXBB_SIZE -
487 				((uintptr_t)dseg & (MLX4_TXBB_SIZE - 1))) >>
488 			       MLX4_SEG_SHIFT;
489 		switch (nb_segs_txbb) {
490 #ifdef RTE_LIBRTE_MLX4_DEBUG
491 		default:
492 			/* Should never happen. */
493 			rte_panic("%p: Invalid number of SGEs(%d) for a TXBB",
494 			(void *)txq, nb_segs_txbb);
495 			/* rte_panic never returns. */
496 			break;
497 #endif /* RTE_LIBRTE_MLX4_DEBUG */
498 		case 4:
499 			/* Memory region key for this memory pool. */
500 			lkey = mlx4_tx_mb2mr(txq, sbuf);
501 			if (unlikely(lkey == (uint32_t)-1))
502 				goto err;
503 			dseg->addr = rte_cpu_to_be_64(data_addr);
504 			dseg->lkey = lkey;
505 			/*
506 			 * This data segment starts at the beginning of a new
507 			 * TXBB, so we need to postpone its byte_count writing
508 			 * for later.
509 			 */
510 			pv[*pv_counter].dseg = dseg;
511 			/*
512 			 * Zero length segment is treated as inline segment
513 			 * with zero data.
514 			 */
515 			pv[(*pv_counter)++].val =
516 				rte_cpu_to_be_32(data_len ?
517 						 data_len :
518 						 0x80000000);
519 			if (--nb_segs == 0)
520 				return ctrl_next;
521 			/* Prepare next buf info */
522 			sbuf = sbuf->next;
523 			dseg++;
524 			data_len = sbuf->data_len;
525 			data_addr = rte_pktmbuf_mtod(sbuf, uintptr_t);
526 			/* fallthrough */
527 		case 3:
528 			lkey = mlx4_tx_mb2mr(txq, sbuf);
529 			if (unlikely(lkey == (uint32_t)-1))
530 				goto err;
531 			mlx4_fill_tx_data_seg(dseg, lkey, data_addr,
532 					rte_cpu_to_be_32(data_len ?
533 							 data_len :
534 							 0x80000000));
535 			if (--nb_segs == 0)
536 				return ctrl_next;
537 			/* Prepare next buf info */
538 			sbuf = sbuf->next;
539 			dseg++;
540 			data_len = sbuf->data_len;
541 			data_addr = rte_pktmbuf_mtod(sbuf, uintptr_t);
542 			/* fallthrough */
543 		case 2:
544 			lkey = mlx4_tx_mb2mr(txq, sbuf);
545 			if (unlikely(lkey == (uint32_t)-1))
546 				goto err;
547 			mlx4_fill_tx_data_seg(dseg, lkey, data_addr,
548 					rte_cpu_to_be_32(data_len ?
549 							 data_len :
550 							 0x80000000));
551 			if (--nb_segs == 0)
552 				return ctrl_next;
553 			/* Prepare next buf info */
554 			sbuf = sbuf->next;
555 			dseg++;
556 			data_len = sbuf->data_len;
557 			data_addr = rte_pktmbuf_mtod(sbuf, uintptr_t);
558 			/* fallthrough */
559 		case 1:
560 			lkey = mlx4_tx_mb2mr(txq, sbuf);
561 			if (unlikely(lkey == (uint32_t)-1))
562 				goto err;
563 			mlx4_fill_tx_data_seg(dseg, lkey, data_addr,
564 					rte_cpu_to_be_32(data_len ?
565 							 data_len :
566 							 0x80000000));
567 			if (--nb_segs == 0)
568 				return ctrl_next;
569 			/* Prepare next buf info */
570 			sbuf = sbuf->next;
571 			dseg++;
572 			data_len = sbuf->data_len;
573 			data_addr = rte_pktmbuf_mtod(sbuf, uintptr_t);
574 			/* fallthrough */
575 		}
576 		/* Wrap dseg if it points at the end of the queue. */
577 		if ((volatile uint8_t *)dseg >= sq->eob)
578 			dseg = (volatile struct mlx4_wqe_data_seg *)
579 					((volatile uint8_t *)dseg - sq->size);
580 	} while (true);
581 err:
582 	return NULL;
583 }
584 
585 /**
586  * Fill the packet's l2, l3 and l4 headers to the WQE.
587  *
588  * This will be used as the header for each TSO segment that is transmitted.
589  *
590  * @param buf
591  *   Pointer to the first packet mbuf.
592  * @param txq
593  *   Pointer to Tx queue structure.
594  * @param tinfo
595  *   Pointer to TSO info to use.
596  * @param ctrl
597  *   Pointer to the control segment in the TSO WQE.
598  *
599  * @return
600  *   0 on success, negative value upon error.
601  */
602 static inline volatile struct mlx4_wqe_data_seg *
603 mlx4_tx_burst_fill_tso_hdr(struct rte_mbuf *buf,
604 			   struct txq *txq,
605 			   struct tso_info *tinfo,
606 			   volatile struct mlx4_wqe_ctrl_seg *ctrl)
607 {
608 	volatile struct mlx4_wqe_lso_seg *tseg =
609 		(volatile struct mlx4_wqe_lso_seg *)(ctrl + 1);
610 	struct mlx4_sq *sq = &txq->msq;
611 	struct pv *pv = tinfo->pv;
612 	int *pv_counter = &tinfo->pv_counter;
613 	int remain_size = tinfo->tso_header_size;
614 	char *from = rte_pktmbuf_mtod(buf, char *);
615 	uint16_t txbb_avail_space;
616 	/* Union to overcome volatile constraints when copying TSO header. */
617 	union {
618 		volatile uint8_t *vto;
619 		uint8_t *to;
620 	} thdr = { .vto = (volatile uint8_t *)tseg->header, };
621 
622 	/*
623 	 * TSO data always starts at offset 20 from the beginning of the TXBB
624 	 * (16 byte ctrl + 4byte TSO desc). Since each TXBB is 64Byte aligned
625 	 * we can write the first 44 TSO header bytes without worry for TxQ
626 	 * wrapping or overwriting the first TXBB 32bit word.
627 	 */
628 	txbb_avail_space = MLX4_TXBB_SIZE -
629 			   (sizeof(struct mlx4_wqe_ctrl_seg) +
630 			    sizeof(struct mlx4_wqe_lso_seg));
631 	while (remain_size >= (int)(txbb_avail_space + sizeof(uint32_t))) {
632 		/* Copy to end of txbb. */
633 		rte_memcpy(thdr.to, from, txbb_avail_space);
634 		from += txbb_avail_space;
635 		thdr.to += txbb_avail_space;
636 		/* New TXBB, Check for TxQ wrap. */
637 		if (thdr.to >= sq->eob)
638 			thdr.vto = sq->buf;
639 		/* New TXBB, stash the first 32bits for later use. */
640 		pv[*pv_counter].dst = (volatile uint32_t *)thdr.to;
641 		pv[(*pv_counter)++].val = *(uint32_t *)from,
642 		from += sizeof(uint32_t);
643 		thdr.to += sizeof(uint32_t);
644 		remain_size -= txbb_avail_space + sizeof(uint32_t);
645 		/* Avail space in new TXBB is TXBB size - 4 */
646 		txbb_avail_space = MLX4_TXBB_SIZE - sizeof(uint32_t);
647 	}
648 	if (remain_size > txbb_avail_space) {
649 		rte_memcpy(thdr.to, from, txbb_avail_space);
650 		from += txbb_avail_space;
651 		thdr.to += txbb_avail_space;
652 		remain_size -= txbb_avail_space;
653 		/* New TXBB, Check for TxQ wrap. */
654 		if (thdr.to >= sq->eob)
655 			thdr.vto = sq->buf;
656 		pv[*pv_counter].dst = (volatile uint32_t *)thdr.to;
657 		rte_memcpy(&pv[*pv_counter].val, from, remain_size);
658 		(*pv_counter)++;
659 	} else if (remain_size) {
660 		rte_memcpy(thdr.to, from, remain_size);
661 	}
662 	tseg->mss_hdr_size = rte_cpu_to_be_32((buf->tso_segsz << 16) |
663 					      tinfo->tso_header_size);
664 	/* Calculate data segment location */
665 	return (volatile struct mlx4_wqe_data_seg *)
666 				((uintptr_t)tseg + tinfo->wqe_tso_seg_size);
667 }
668 
669 /**
670  * Write data segments and header for TSO uni/multi segment packet.
671  *
672  * @param buf
673  *   Pointer to the first packet mbuf.
674  * @param txq
675  *   Pointer to Tx queue structure.
676  * @param ctrl
677  *   Pointer to the WQE control segment.
678  *
679  * @return
680  *   Pointer to the next WQE control segment on success, NULL otherwise.
681  */
682 static volatile struct mlx4_wqe_ctrl_seg *
683 mlx4_tx_burst_tso(struct rte_mbuf *buf, struct txq *txq,
684 		  volatile struct mlx4_wqe_ctrl_seg *ctrl)
685 {
686 	volatile struct mlx4_wqe_data_seg *dseg;
687 	volatile struct mlx4_wqe_ctrl_seg *ctrl_next;
688 	struct mlx4_sq *sq = &txq->msq;
689 	struct tso_info tinfo;
690 	struct pv *pv;
691 	int pv_counter;
692 	int ret;
693 
694 	ret = mlx4_tx_burst_tso_get_params(buf, txq, &tinfo);
695 	if (unlikely(ret))
696 		goto error;
697 	dseg = mlx4_tx_burst_fill_tso_hdr(buf, txq, &tinfo, ctrl);
698 	if (unlikely(dseg == NULL))
699 		goto error;
700 	if ((uintptr_t)dseg >= (uintptr_t)sq->eob)
701 		dseg = (volatile struct mlx4_wqe_data_seg *)
702 					((uintptr_t)dseg - sq->size);
703 	ctrl_next = mlx4_tx_burst_fill_tso_dsegs(buf, txq, &tinfo, dseg, ctrl);
704 	if (unlikely(ctrl_next == NULL))
705 		goto error;
706 	/* Write the first DWORD of each TXBB save earlier. */
707 	if (likely(tinfo.pv_counter)) {
708 		pv = tinfo.pv;
709 		pv_counter = tinfo.pv_counter;
710 		/* Need a barrier here before writing the first TXBB word. */
711 		rte_io_wmb();
712 		do {
713 			--pv_counter;
714 			*pv[pv_counter].dst = pv[pv_counter].val;
715 		} while (pv_counter > 0);
716 	}
717 	ctrl->fence_size = tinfo.fence_size;
718 	sq->remain_size -= tinfo.wqe_size;
719 	return ctrl_next;
720 error:
721 	txq->stats.odropped++;
722 	return NULL;
723 }
724 
725 /**
726  * Write data segments of multi-segment packet.
727  *
728  * @param buf
729  *   Pointer to the first packet mbuf.
730  * @param txq
731  *   Pointer to Tx queue structure.
732  * @param ctrl
733  *   Pointer to the WQE control segment.
734  *
735  * @return
736  *   Pointer to the next WQE control segment on success, NULL otherwise.
737  */
738 static volatile struct mlx4_wqe_ctrl_seg *
739 mlx4_tx_burst_segs(struct rte_mbuf *buf, struct txq *txq,
740 		   volatile struct mlx4_wqe_ctrl_seg *ctrl)
741 {
742 	struct pv *pv = (struct pv *)txq->bounce_buf;
743 	struct mlx4_sq *sq = &txq->msq;
744 	struct rte_mbuf *sbuf = buf;
745 	uint32_t lkey;
746 	int pv_counter = 0;
747 	int nb_segs = buf->nb_segs;
748 	uint32_t wqe_size;
749 	volatile struct mlx4_wqe_data_seg *dseg =
750 		(volatile struct mlx4_wqe_data_seg *)(ctrl + 1);
751 
752 	ctrl->fence_size = 1 + nb_segs;
753 	wqe_size = RTE_ALIGN((uint32_t)(ctrl->fence_size << MLX4_SEG_SHIFT),
754 			     MLX4_TXBB_SIZE);
755 	/* Validate WQE size and WQE space in the send queue. */
756 	if (sq->remain_size < wqe_size ||
757 	    wqe_size > MLX4_MAX_WQE_SIZE)
758 		return NULL;
759 	/*
760 	 * Fill the data segments with buffer information.
761 	 * First WQE TXBB head segment is always control segment,
762 	 * so jump to tail TXBB data segments code for the first
763 	 * WQE data segments filling.
764 	 */
765 	goto txbb_tail_segs;
766 txbb_head_seg:
767 	/* Memory region key (big endian) for this memory pool. */
768 	lkey = mlx4_tx_mb2mr(txq, sbuf);
769 	if (unlikely(lkey == (uint32_t)-1)) {
770 		DEBUG("%p: unable to get MP <-> MR association",
771 		      (void *)txq);
772 		return NULL;
773 	}
774 	/* Handle WQE wraparound. */
775 	if (dseg >=
776 		(volatile struct mlx4_wqe_data_seg *)sq->eob)
777 		dseg = (volatile struct mlx4_wqe_data_seg *)
778 			sq->buf;
779 	dseg->addr = rte_cpu_to_be_64(rte_pktmbuf_mtod(sbuf, uintptr_t));
780 	dseg->lkey = lkey;
781 	/*
782 	 * This data segment starts at the beginning of a new
783 	 * TXBB, so we need to postpone its byte_count writing
784 	 * for later.
785 	 */
786 	pv[pv_counter].dseg = dseg;
787 	/*
788 	 * Zero length segment is treated as inline segment
789 	 * with zero data.
790 	 */
791 	pv[pv_counter++].val = rte_cpu_to_be_32(sbuf->data_len ?
792 						sbuf->data_len : 0x80000000);
793 	sbuf = sbuf->next;
794 	dseg++;
795 	nb_segs--;
796 txbb_tail_segs:
797 	/* Jump to default if there are more than two segments remaining. */
798 	switch (nb_segs) {
799 	default:
800 		lkey = mlx4_tx_mb2mr(txq, sbuf);
801 		if (unlikely(lkey == (uint32_t)-1)) {
802 			DEBUG("%p: unable to get MP <-> MR association",
803 			      (void *)txq);
804 			return NULL;
805 		}
806 		mlx4_fill_tx_data_seg(dseg, lkey,
807 				      rte_pktmbuf_mtod(sbuf, uintptr_t),
808 				      rte_cpu_to_be_32(sbuf->data_len ?
809 						       sbuf->data_len :
810 						       0x80000000));
811 		sbuf = sbuf->next;
812 		dseg++;
813 		nb_segs--;
814 		/* fallthrough */
815 	case 2:
816 		lkey = mlx4_tx_mb2mr(txq, sbuf);
817 		if (unlikely(lkey == (uint32_t)-1)) {
818 			DEBUG("%p: unable to get MP <-> MR association",
819 			      (void *)txq);
820 			return NULL;
821 		}
822 		mlx4_fill_tx_data_seg(dseg, lkey,
823 				      rte_pktmbuf_mtod(sbuf, uintptr_t),
824 				      rte_cpu_to_be_32(sbuf->data_len ?
825 						       sbuf->data_len :
826 						       0x80000000));
827 		sbuf = sbuf->next;
828 		dseg++;
829 		nb_segs--;
830 		/* fallthrough */
831 	case 1:
832 		lkey = mlx4_tx_mb2mr(txq, sbuf);
833 		if (unlikely(lkey == (uint32_t)-1)) {
834 			DEBUG("%p: unable to get MP <-> MR association",
835 			      (void *)txq);
836 			return NULL;
837 		}
838 		mlx4_fill_tx_data_seg(dseg, lkey,
839 				      rte_pktmbuf_mtod(sbuf, uintptr_t),
840 				      rte_cpu_to_be_32(sbuf->data_len ?
841 						       sbuf->data_len :
842 						       0x80000000));
843 		nb_segs--;
844 		if (nb_segs) {
845 			sbuf = sbuf->next;
846 			dseg++;
847 			goto txbb_head_seg;
848 		}
849 		/* fallthrough */
850 	case 0:
851 		break;
852 	}
853 	/* Write the first DWORD of each TXBB save earlier. */
854 	if (pv_counter) {
855 		/* Need a barrier here before writing the byte_count. */
856 		rte_io_wmb();
857 		for (--pv_counter; pv_counter  >= 0; pv_counter--)
858 			pv[pv_counter].dseg->byte_count = pv[pv_counter].val;
859 	}
860 	sq->remain_size -= wqe_size;
861 	/* Align next WQE address to the next TXBB. */
862 	return (volatile struct mlx4_wqe_ctrl_seg *)
863 		((volatile uint8_t *)ctrl + wqe_size);
864 }
865 
866 /**
867  * DPDK callback for Tx.
868  *
869  * @param dpdk_txq
870  *   Generic pointer to Tx queue structure.
871  * @param[in] pkts
872  *   Packets to transmit.
873  * @param pkts_n
874  *   Number of packets in array.
875  *
876  * @return
877  *   Number of packets successfully transmitted (<= pkts_n).
878  */
879 uint16_t
880 mlx4_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
881 {
882 	struct txq *txq = (struct txq *)dpdk_txq;
883 	unsigned int elts_head = txq->elts_head;
884 	const unsigned int elts_n = txq->elts_n;
885 	const unsigned int elts_m = elts_n - 1;
886 	unsigned int bytes_sent = 0;
887 	unsigned int i;
888 	unsigned int max = elts_head - txq->elts_tail;
889 	struct mlx4_sq *sq = &txq->msq;
890 	volatile struct mlx4_wqe_ctrl_seg *ctrl;
891 	struct txq_elt *elt;
892 
893 	MLX4_ASSERT(txq->elts_comp_cd != 0);
894 	if (likely(max >= txq->elts_comp_cd_init))
895 		mlx4_txq_complete(txq, elts_m, sq);
896 	max = elts_n - max;
897 	MLX4_ASSERT(max >= 1);
898 	MLX4_ASSERT(max <= elts_n);
899 	/* Always leave one free entry in the ring. */
900 	--max;
901 	if (max > pkts_n)
902 		max = pkts_n;
903 	elt = &(*txq->elts)[elts_head & elts_m];
904 	/* First Tx burst element saves the next WQE control segment. */
905 	ctrl = elt->wqe;
906 	for (i = 0; (i != max); ++i) {
907 		struct rte_mbuf *buf = pkts[i];
908 		struct txq_elt *elt_next = &(*txq->elts)[++elts_head & elts_m];
909 		uint32_t owner_opcode = sq->owner_opcode;
910 		volatile struct mlx4_wqe_data_seg *dseg =
911 				(volatile struct mlx4_wqe_data_seg *)(ctrl + 1);
912 		volatile struct mlx4_wqe_ctrl_seg *ctrl_next;
913 		union {
914 			uint32_t flags;
915 			uint16_t flags16[2];
916 		} srcrb;
917 		uint32_t lkey;
918 		bool tso = txq->priv->tso && (buf->ol_flags & PKT_TX_TCP_SEG);
919 
920 		/* Clean up old buffer. */
921 		if (likely(elt->buf != NULL)) {
922 			struct rte_mbuf *tmp = elt->buf;
923 
924 #ifdef RTE_LIBRTE_MLX4_DEBUG
925 			/* Poisoning. */
926 			memset(&elt->buf, 0x66, sizeof(struct rte_mbuf *));
927 #endif
928 			/* Faster than rte_pktmbuf_free(). */
929 			do {
930 				struct rte_mbuf *next = tmp->next;
931 
932 				rte_pktmbuf_free_seg(tmp);
933 				tmp = next;
934 			} while (tmp != NULL);
935 		}
936 		RTE_MBUF_PREFETCH_TO_FREE(elt_next->buf);
937 		if (tso) {
938 			/* Change opcode to TSO */
939 			owner_opcode &= ~MLX4_OPCODE_CONFIG_CMD;
940 			owner_opcode |= MLX4_OPCODE_LSO | MLX4_WQE_CTRL_RR;
941 			ctrl_next = mlx4_tx_burst_tso(buf, txq, ctrl);
942 			if (!ctrl_next) {
943 				elt->buf = NULL;
944 				break;
945 			}
946 		} else if (buf->nb_segs == 1) {
947 			/* Validate WQE space in the send queue. */
948 			if (sq->remain_size < MLX4_TXBB_SIZE) {
949 				elt->buf = NULL;
950 				break;
951 			}
952 			lkey = mlx4_tx_mb2mr(txq, buf);
953 			if (unlikely(lkey == (uint32_t)-1)) {
954 				/* MR does not exist. */
955 				DEBUG("%p: unable to get MP <-> MR association",
956 				      (void *)txq);
957 				elt->buf = NULL;
958 				break;
959 			}
960 			mlx4_fill_tx_data_seg(dseg++, lkey,
961 					      rte_pktmbuf_mtod(buf, uintptr_t),
962 					      rte_cpu_to_be_32(buf->data_len));
963 			/* Set WQE size in 16-byte units. */
964 			ctrl->fence_size = 0x2;
965 			sq->remain_size -= MLX4_TXBB_SIZE;
966 			/* Align next WQE address to the next TXBB. */
967 			ctrl_next = ctrl + 0x4;
968 		} else {
969 			ctrl_next = mlx4_tx_burst_segs(buf, txq, ctrl);
970 			if (!ctrl_next) {
971 				elt->buf = NULL;
972 				break;
973 			}
974 		}
975 		/* Hold SQ ring wrap around. */
976 		if ((volatile uint8_t *)ctrl_next >= sq->eob) {
977 			ctrl_next = (volatile struct mlx4_wqe_ctrl_seg *)
978 				((volatile uint8_t *)ctrl_next - sq->size);
979 			/* Flip HW valid ownership. */
980 			sq->owner_opcode ^= 1u << MLX4_SQ_OWNER_BIT;
981 		}
982 		/*
983 		 * For raw Ethernet, the SOLICIT flag is used to indicate
984 		 * that no ICRC should be calculated.
985 		 */
986 		if (--txq->elts_comp_cd == 0) {
987 			/* Save the completion burst end address. */
988 			elt_next->eocb = (volatile uint32_t *)ctrl_next;
989 			txq->elts_comp_cd = txq->elts_comp_cd_init;
990 			srcrb.flags = RTE_BE32(MLX4_WQE_CTRL_SOLICIT |
991 					       MLX4_WQE_CTRL_CQ_UPDATE);
992 		} else {
993 			srcrb.flags = RTE_BE32(MLX4_WQE_CTRL_SOLICIT);
994 		}
995 		/* Enable HW checksum offload if requested */
996 		if (txq->csum &&
997 		    (buf->ol_flags &
998 		     (PKT_TX_IP_CKSUM | PKT_TX_TCP_CKSUM | PKT_TX_UDP_CKSUM))) {
999 			const uint64_t is_tunneled = (buf->ol_flags &
1000 						      (PKT_TX_TUNNEL_GRE |
1001 						       PKT_TX_TUNNEL_VXLAN));
1002 
1003 			if (is_tunneled && txq->csum_l2tun) {
1004 				owner_opcode |= MLX4_WQE_CTRL_IIP_HDR_CSUM |
1005 						MLX4_WQE_CTRL_IL4_HDR_CSUM;
1006 				if (buf->ol_flags & PKT_TX_OUTER_IP_CKSUM)
1007 					srcrb.flags |=
1008 					    RTE_BE32(MLX4_WQE_CTRL_IP_HDR_CSUM);
1009 			} else {
1010 				srcrb.flags |=
1011 					RTE_BE32(MLX4_WQE_CTRL_IP_HDR_CSUM |
1012 						MLX4_WQE_CTRL_TCP_UDP_CSUM);
1013 			}
1014 		}
1015 		if (txq->lb) {
1016 			/*
1017 			 * Copy destination MAC address to the WQE, this allows
1018 			 * loopback in eSwitch, so that VFs and PF can
1019 			 * communicate with each other.
1020 			 */
1021 			srcrb.flags16[0] = *(rte_pktmbuf_mtod(buf, uint16_t *));
1022 			ctrl->imm = *(rte_pktmbuf_mtod_offset(buf, uint32_t *,
1023 					      sizeof(uint16_t)));
1024 		} else {
1025 			ctrl->imm = 0;
1026 		}
1027 		ctrl->srcrb_flags = srcrb.flags;
1028 		/*
1029 		 * Make sure descriptor is fully written before
1030 		 * setting ownership bit (because HW can start
1031 		 * executing as soon as we do).
1032 		 */
1033 		rte_io_wmb();
1034 		ctrl->owner_opcode = rte_cpu_to_be_32(owner_opcode);
1035 		elt->buf = buf;
1036 		bytes_sent += buf->pkt_len;
1037 		ctrl = ctrl_next;
1038 		elt = elt_next;
1039 	}
1040 	/* Take a shortcut if nothing must be sent. */
1041 	if (unlikely(i == 0))
1042 		return 0;
1043 	/* Save WQE address of the next Tx burst element. */
1044 	elt->wqe = ctrl;
1045 	/* Increment send statistics counters. */
1046 	txq->stats.opackets += i;
1047 	txq->stats.obytes += bytes_sent;
1048 	/* Make sure that descriptors are written before doorbell record. */
1049 	rte_wmb();
1050 	/* Ring QP doorbell. */
1051 	rte_write32(txq->msq.doorbell_qpn, MLX4_TX_BFREG(txq));
1052 	txq->elts_head += i;
1053 	return i;
1054 }
1055 
1056 /**
1057  * Translate Rx completion flags to packet type.
1058  *
1059  * @param[in] cqe
1060  *   Pointer to CQE.
1061  *
1062  * @return
1063  *   Packet type for struct rte_mbuf.
1064  */
1065 static inline uint32_t
1066 rxq_cq_to_pkt_type(volatile struct mlx4_cqe *cqe,
1067 		   uint32_t l2tun_offload)
1068 {
1069 	uint8_t idx = 0;
1070 	uint32_t pinfo = rte_be_to_cpu_32(cqe->vlan_my_qpn);
1071 	uint32_t status = rte_be_to_cpu_32(cqe->status);
1072 
1073 	/*
1074 	 * The index to the array should have:
1075 	 *  bit[7] - MLX4_CQE_L2_TUNNEL
1076 	 *  bit[6] - MLX4_CQE_L2_TUNNEL_IPV4
1077 	 */
1078 	if (l2tun_offload && (pinfo & MLX4_CQE_L2_TUNNEL))
1079 		idx |= ((pinfo & MLX4_CQE_L2_TUNNEL) >> 20) |
1080 		       ((pinfo & MLX4_CQE_L2_TUNNEL_IPV4) >> 19);
1081 	/*
1082 	 * The index to the array should have:
1083 	 *  bit[5] - MLX4_CQE_STATUS_UDP
1084 	 *  bit[4] - MLX4_CQE_STATUS_TCP
1085 	 *  bit[3] - MLX4_CQE_STATUS_IPV4OPT
1086 	 *  bit[2] - MLX4_CQE_STATUS_IPV6
1087 	 *  bit[1] - MLX4_CQE_STATUS_IPF
1088 	 *  bit[0] - MLX4_CQE_STATUS_IPV4
1089 	 * giving a total of up to 256 entries.
1090 	 */
1091 	idx |= ((status & MLX4_CQE_STATUS_PTYPE_MASK) >> 22);
1092 	if (status & MLX4_CQE_STATUS_IPV6)
1093 		idx |= ((status & MLX4_CQE_STATUS_IPV6F) >> 11);
1094 	return mlx4_ptype_table[idx];
1095 }
1096 
1097 /**
1098  * Translate Rx completion flags to offload flags.
1099  *
1100  * @param flags
1101  *   Rx completion flags returned by mlx4_cqe_flags().
1102  * @param csum
1103  *   Whether Rx checksums are enabled.
1104  * @param csum_l2tun
1105  *   Whether Rx L2 tunnel checksums are enabled.
1106  *
1107  * @return
1108  *   Offload flags (ol_flags) in mbuf format.
1109  */
1110 static inline uint32_t
1111 rxq_cq_to_ol_flags(uint32_t flags, int csum, int csum_l2tun)
1112 {
1113 	uint32_t ol_flags = 0;
1114 
1115 	if (csum)
1116 		ol_flags |=
1117 			mlx4_transpose(flags,
1118 				       MLX4_CQE_STATUS_IP_HDR_CSUM_OK,
1119 				       PKT_RX_IP_CKSUM_GOOD) |
1120 			mlx4_transpose(flags,
1121 				       MLX4_CQE_STATUS_TCP_UDP_CSUM_OK,
1122 				       PKT_RX_L4_CKSUM_GOOD);
1123 	if ((flags & MLX4_CQE_L2_TUNNEL) && csum_l2tun)
1124 		ol_flags |=
1125 			mlx4_transpose(flags,
1126 				       MLX4_CQE_L2_TUNNEL_IPOK,
1127 				       PKT_RX_IP_CKSUM_GOOD) |
1128 			mlx4_transpose(flags,
1129 				       MLX4_CQE_L2_TUNNEL_L4_CSUM,
1130 				       PKT_RX_L4_CKSUM_GOOD);
1131 	return ol_flags;
1132 }
1133 
1134 /**
1135  * Extract checksum information from CQE flags.
1136  *
1137  * @param cqe
1138  *   Pointer to CQE structure.
1139  * @param csum
1140  *   Whether Rx checksums are enabled.
1141  * @param csum_l2tun
1142  *   Whether Rx L2 tunnel checksums are enabled.
1143  *
1144  * @return
1145  *   CQE checksum information.
1146  */
1147 static inline uint32_t
1148 mlx4_cqe_flags(volatile struct mlx4_cqe *cqe, int csum, int csum_l2tun)
1149 {
1150 	uint32_t flags = 0;
1151 
1152 	/*
1153 	 * The relevant bits are in different locations on their
1154 	 * CQE fields therefore we can join them in one 32bit
1155 	 * variable.
1156 	 */
1157 	if (csum)
1158 		flags = (rte_be_to_cpu_32(cqe->status) &
1159 			 MLX4_CQE_STATUS_IPV4_CSUM_OK);
1160 	if (csum_l2tun)
1161 		flags |= (rte_be_to_cpu_32(cqe->vlan_my_qpn) &
1162 			  (MLX4_CQE_L2_TUNNEL |
1163 			   MLX4_CQE_L2_TUNNEL_IPOK |
1164 			   MLX4_CQE_L2_TUNNEL_L4_CSUM |
1165 			   MLX4_CQE_L2_TUNNEL_IPV4));
1166 	return flags;
1167 }
1168 
1169 /**
1170  * Poll one CQE from CQ.
1171  *
1172  * @param rxq
1173  *   Pointer to the receive queue structure.
1174  * @param[out] out
1175  *   Just polled CQE.
1176  *
1177  * @return
1178  *   Number of bytes of the CQE, 0 in case there is no completion.
1179  */
1180 static unsigned int
1181 mlx4_cq_poll_one(struct rxq *rxq, volatile struct mlx4_cqe **out)
1182 {
1183 	int ret = 0;
1184 	volatile struct mlx4_cqe *cqe = NULL;
1185 	struct mlx4_cq *cq = &rxq->mcq;
1186 
1187 	cqe = (volatile struct mlx4_cqe *)mlx4_get_cqe(cq, cq->cons_index);
1188 	if (!!(cqe->owner_sr_opcode & MLX4_CQE_OWNER_MASK) ^
1189 	    !!(cq->cons_index & cq->cqe_cnt))
1190 		goto out;
1191 	/*
1192 	 * Make sure we read CQ entry contents after we've checked the
1193 	 * ownership bit.
1194 	 */
1195 	rte_rmb();
1196 	MLX4_ASSERT(!(cqe->owner_sr_opcode & MLX4_CQE_IS_SEND_MASK));
1197 	MLX4_ASSERT((cqe->owner_sr_opcode & MLX4_CQE_OPCODE_MASK) !=
1198 		    MLX4_CQE_OPCODE_ERROR);
1199 	ret = rte_be_to_cpu_32(cqe->byte_cnt);
1200 	++cq->cons_index;
1201 out:
1202 	*out = cqe;
1203 	return ret;
1204 }
1205 
1206 /**
1207  * DPDK callback for Rx with scattered packets support.
1208  *
1209  * @param dpdk_rxq
1210  *   Generic pointer to Rx queue structure.
1211  * @param[out] pkts
1212  *   Array to store received packets.
1213  * @param pkts_n
1214  *   Maximum number of packets in array.
1215  *
1216  * @return
1217  *   Number of packets successfully received (<= pkts_n).
1218  */
1219 uint16_t
1220 mlx4_rx_burst(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
1221 {
1222 	struct rxq *rxq = dpdk_rxq;
1223 	const uint32_t wr_cnt = (1 << rxq->elts_n) - 1;
1224 	const uint16_t sges_n = rxq->sges_n;
1225 	struct rte_mbuf *pkt = NULL;
1226 	struct rte_mbuf *seg = NULL;
1227 	unsigned int i = 0;
1228 	uint32_t rq_ci = rxq->rq_ci << sges_n;
1229 	int len = 0;
1230 
1231 	while (pkts_n) {
1232 		volatile struct mlx4_cqe *cqe;
1233 		uint32_t idx = rq_ci & wr_cnt;
1234 		struct rte_mbuf *rep = (*rxq->elts)[idx];
1235 		volatile struct mlx4_wqe_data_seg *scat = &(*rxq->wqes)[idx];
1236 
1237 		/* Update the 'next' pointer of the previous segment. */
1238 		if (pkt)
1239 			seg->next = rep;
1240 		seg = rep;
1241 		rte_prefetch0(seg);
1242 		rte_prefetch0(scat);
1243 		rep = rte_mbuf_raw_alloc(rxq->mp);
1244 		if (unlikely(rep == NULL)) {
1245 			++rxq->stats.rx_nombuf;
1246 			if (!pkt) {
1247 				/*
1248 				 * No buffers before we even started,
1249 				 * bail out silently.
1250 				 */
1251 				break;
1252 			}
1253 			while (pkt != seg) {
1254 				MLX4_ASSERT(pkt != (*rxq->elts)[idx]);
1255 				rep = pkt->next;
1256 				pkt->next = NULL;
1257 				pkt->nb_segs = 1;
1258 				rte_mbuf_raw_free(pkt);
1259 				pkt = rep;
1260 			}
1261 			break;
1262 		}
1263 		if (!pkt) {
1264 			/* Looking for the new packet. */
1265 			len = mlx4_cq_poll_one(rxq, &cqe);
1266 			if (!len) {
1267 				rte_mbuf_raw_free(rep);
1268 				break;
1269 			}
1270 			if (unlikely(len < 0)) {
1271 				/* Rx error, packet is likely too large. */
1272 				rte_mbuf_raw_free(rep);
1273 				++rxq->stats.idropped;
1274 				goto skip;
1275 			}
1276 			pkt = seg;
1277 			MLX4_ASSERT(len >= (rxq->crc_present << 2));
1278 			/* Update packet information. */
1279 			pkt->packet_type =
1280 				rxq_cq_to_pkt_type(cqe, rxq->l2tun_offload);
1281 			pkt->ol_flags = PKT_RX_RSS_HASH;
1282 			pkt->hash.rss = cqe->immed_rss_invalid;
1283 			if (rxq->crc_present)
1284 				len -= RTE_ETHER_CRC_LEN;
1285 			pkt->pkt_len = len;
1286 			if (rxq->csum | rxq->csum_l2tun) {
1287 				uint32_t flags =
1288 					mlx4_cqe_flags(cqe,
1289 						       rxq->csum,
1290 						       rxq->csum_l2tun);
1291 
1292 				pkt->ol_flags =
1293 					rxq_cq_to_ol_flags(flags,
1294 							   rxq->csum,
1295 							   rxq->csum_l2tun);
1296 			}
1297 		}
1298 		rep->nb_segs = 1;
1299 		rep->port = rxq->port_id;
1300 		rep->data_len = seg->data_len;
1301 		rep->data_off = seg->data_off;
1302 		(*rxq->elts)[idx] = rep;
1303 		/*
1304 		 * Fill NIC descriptor with the new buffer. The lkey and size
1305 		 * of the buffers are already known, only the buffer address
1306 		 * changes.
1307 		 */
1308 		scat->addr = rte_cpu_to_be_64(rte_pktmbuf_mtod(rep, uintptr_t));
1309 		/* If there's only one MR, no need to replace LKey in WQE. */
1310 		if (unlikely(mlx4_mr_btree_len(&rxq->mr_ctrl.cache_bh) > 1))
1311 			scat->lkey = mlx4_rx_mb2mr(rxq, rep);
1312 		if (len > seg->data_len) {
1313 			len -= seg->data_len;
1314 			++pkt->nb_segs;
1315 			++rq_ci;
1316 			continue;
1317 		}
1318 		/* The last segment. */
1319 		seg->data_len = len;
1320 		/* Increment bytes counter. */
1321 		rxq->stats.ibytes += pkt->pkt_len;
1322 		/* Return packet. */
1323 		*(pkts++) = pkt;
1324 		pkt = NULL;
1325 		--pkts_n;
1326 		++i;
1327 skip:
1328 		/* Align consumer index to the next stride. */
1329 		rq_ci >>= sges_n;
1330 		++rq_ci;
1331 		rq_ci <<= sges_n;
1332 	}
1333 	if (unlikely(i == 0 && (rq_ci >> sges_n) == rxq->rq_ci))
1334 		return 0;
1335 	/* Update the consumer index. */
1336 	rxq->rq_ci = rq_ci >> sges_n;
1337 	rte_wmb();
1338 	*rxq->rq_db = rte_cpu_to_be_32(rxq->rq_ci);
1339 	*rxq->mcq.set_ci_db =
1340 		rte_cpu_to_be_32(rxq->mcq.cons_index & MLX4_CQ_DB_CI_MASK);
1341 	/* Increment packets counter. */
1342 	rxq->stats.ipackets += i;
1343 	return i;
1344 }
1345 
1346 /**
1347  * Dummy DPDK callback for Tx.
1348  *
1349  * This function is used to temporarily replace the real callback during
1350  * unsafe control operations on the queue, or in case of error.
1351  *
1352  * @param dpdk_txq
1353  *   Generic pointer to Tx queue structure.
1354  * @param[in] pkts
1355  *   Packets to transmit.
1356  * @param pkts_n
1357  *   Number of packets in array.
1358  *
1359  * @return
1360  *   Number of packets successfully transmitted (<= pkts_n).
1361  */
1362 uint16_t
1363 mlx4_tx_burst_removed(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
1364 {
1365 	(void)dpdk_txq;
1366 	(void)pkts;
1367 	(void)pkts_n;
1368 	rte_mb();
1369 	return 0;
1370 }
1371 
1372 /**
1373  * Dummy DPDK callback for Rx.
1374  *
1375  * This function is used to temporarily replace the real callback during
1376  * unsafe control operations on the queue, or in case of error.
1377  *
1378  * @param dpdk_rxq
1379  *   Generic pointer to Rx queue structure.
1380  * @param[out] pkts
1381  *   Array to store received packets.
1382  * @param pkts_n
1383  *   Maximum number of packets in array.
1384  *
1385  * @return
1386  *   Number of packets successfully received (<= pkts_n).
1387  */
1388 uint16_t
1389 mlx4_rx_burst_removed(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
1390 {
1391 	(void)dpdk_rxq;
1392 	(void)pkts;
1393 	(void)pkts_n;
1394 	rte_mb();
1395 	return 0;
1396 }
1397