xref: /dpdk/drivers/net/intel/iavf/iavf_rxtx_vec_common.h (revision cef05386b08a19741f0559f7f072eefb8b59f0bb)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2017 Intel Corporation
3  */
4 
5 #ifndef _IAVF_RXTX_VEC_COMMON_H_
6 #define _IAVF_RXTX_VEC_COMMON_H_
7 #include <stdint.h>
8 #include <ethdev_driver.h>
9 #include <rte_malloc.h>
10 
11 #include "../common/rx.h"
12 #include "iavf.h"
13 #include "iavf_rxtx.h"
14 
15 static __rte_always_inline uint16_t
16 reassemble_packets(struct iavf_rx_queue *rxq, struct rte_mbuf **rx_bufs,
17 		   uint16_t nb_bufs, uint8_t *split_flags)
18 {
19 	struct rte_mbuf *pkts[IAVF_VPMD_RX_MAX_BURST];
20 	struct rte_mbuf *start = rxq->pkt_first_seg;
21 	struct rte_mbuf *end =  rxq->pkt_last_seg;
22 	unsigned int pkt_idx, buf_idx;
23 
24 	for (buf_idx = 0, pkt_idx = 0; buf_idx < nb_bufs; buf_idx++) {
25 		if (end) {
26 			/* processing a split packet */
27 			end->next = rx_bufs[buf_idx];
28 			rx_bufs[buf_idx]->data_len += rxq->crc_len;
29 
30 			start->nb_segs++;
31 			start->pkt_len += rx_bufs[buf_idx]->data_len;
32 			end = end->next;
33 
34 			if (!split_flags[buf_idx]) {
35 				/* it's the last packet of the set */
36 				start->hash = end->hash;
37 				start->vlan_tci = end->vlan_tci;
38 				start->ol_flags = end->ol_flags;
39 				/* we need to strip crc for the whole packet */
40 				start->pkt_len -= rxq->crc_len;
41 				if (end->data_len > rxq->crc_len) {
42 					end->data_len -= rxq->crc_len;
43 				} else {
44 					/* free up last mbuf */
45 					struct rte_mbuf *secondlast = start;
46 
47 					start->nb_segs--;
48 					while (secondlast->next != end)
49 						secondlast = secondlast->next;
50 					secondlast->data_len -= (rxq->crc_len -
51 							end->data_len);
52 					secondlast->next = NULL;
53 					rte_pktmbuf_free_seg(end);
54 				}
55 				pkts[pkt_idx++] = start;
56 				start = NULL;
57 				end = NULL;
58 			}
59 		} else {
60 			/* not processing a split packet */
61 			if (!split_flags[buf_idx]) {
62 				/* not a split packet, save and skip */
63 				pkts[pkt_idx++] = rx_bufs[buf_idx];
64 				continue;
65 			}
66 			end = start = rx_bufs[buf_idx];
67 			rx_bufs[buf_idx]->data_len += rxq->crc_len;
68 			rx_bufs[buf_idx]->pkt_len += rxq->crc_len;
69 		}
70 	}
71 
72 	/* save the partial packet for next time */
73 	rxq->pkt_first_seg = start;
74 	rxq->pkt_last_seg = end;
75 	memcpy(rx_bufs, pkts, pkt_idx * (sizeof(*pkts)));
76 	return pkt_idx;
77 }
78 
79 static inline int
80 iavf_tx_desc_done(struct ci_tx_queue *txq, uint16_t idx)
81 {
82 	return (txq->iavf_tx_ring[idx].cmd_type_offset_bsz &
83 			rte_cpu_to_le_64(IAVF_TXD_QW1_DTYPE_MASK)) ==
84 				rte_cpu_to_le_64(IAVF_TX_DESC_DTYPE_DESC_DONE);
85 }
86 
87 static __rte_always_inline int
88 iavf_tx_free_bufs(struct ci_tx_queue *txq)
89 {
90 	return ci_tx_free_bufs(txq, iavf_tx_desc_done);
91 }
92 
93 static inline void
94 _iavf_rx_queue_release_mbufs_vec(struct iavf_rx_queue *rxq)
95 {
96 	const unsigned int mask = rxq->nb_rx_desc - 1;
97 	unsigned int i;
98 
99 	if (!rxq->sw_ring || rxq->rxrearm_nb >= rxq->nb_rx_desc)
100 		return;
101 
102 	/* free all mbufs that are valid in the ring */
103 	if (rxq->rxrearm_nb == 0) {
104 		for (i = 0; i < rxq->nb_rx_desc; i++) {
105 			if (rxq->sw_ring[i])
106 				rte_pktmbuf_free_seg(rxq->sw_ring[i]);
107 		}
108 	} else {
109 		for (i = rxq->rx_tail;
110 		     i != rxq->rxrearm_start;
111 		     i = (i + 1) & mask) {
112 			if (rxq->sw_ring[i])
113 				rte_pktmbuf_free_seg(rxq->sw_ring[i]);
114 		}
115 	}
116 
117 	rxq->rxrearm_nb = rxq->nb_rx_desc;
118 
119 	/* set all entries to NULL */
120 	memset(rxq->sw_ring, 0, sizeof(rxq->sw_ring[0]) * rxq->nb_rx_desc);
121 }
122 
123 static inline int
124 iavf_rxq_vec_setup_default(struct iavf_rx_queue *rxq)
125 {
126 	uintptr_t p;
127 	struct rte_mbuf mb_def = { .buf_addr = 0 }; /* zeroed mbuf */
128 
129 	mb_def.nb_segs = 1;
130 	mb_def.data_off = RTE_PKTMBUF_HEADROOM;
131 	mb_def.port = rxq->port_id;
132 	rte_mbuf_refcnt_set(&mb_def, 1);
133 
134 	/* prevent compiler reordering: rearm_data covers previous fields */
135 	rte_compiler_barrier();
136 	p = (uintptr_t)&mb_def.rearm_data;
137 	rxq->mbuf_initializer = *(uint64_t *)p;
138 	return 0;
139 }
140 
141 static inline int
142 iavf_rx_vec_queue_default(struct iavf_rx_queue *rxq)
143 {
144 	if (!rxq)
145 		return -1;
146 
147 	if (!rte_is_power_of_2(rxq->nb_rx_desc))
148 		return -1;
149 
150 	if (rxq->rx_free_thresh < IAVF_VPMD_RX_MAX_BURST)
151 		return -1;
152 
153 	if (rxq->nb_rx_desc % rxq->rx_free_thresh)
154 		return -1;
155 
156 	if (rxq->proto_xtr != IAVF_PROTO_XTR_NONE)
157 		return -1;
158 
159 	if (rxq->offloads & IAVF_RX_VECTOR_OFFLOAD)
160 		return IAVF_VECTOR_OFFLOAD_PATH;
161 
162 	return IAVF_VECTOR_PATH;
163 }
164 
165 static inline int
166 iavf_tx_vec_queue_default(struct ci_tx_queue *txq)
167 {
168 	if (!txq)
169 		return -1;
170 
171 	if (txq->tx_rs_thresh < IAVF_VPMD_TX_MAX_BURST ||
172 	    txq->tx_rs_thresh > IAVF_VPMD_TX_MAX_FREE_BUF)
173 		return -1;
174 
175 	if (txq->offloads & IAVF_TX_NO_VECTOR_FLAGS)
176 		return -1;
177 
178 	if (rte_pmd_iavf_tx_lldp_dynfield_offset > 0) {
179 		txq->use_ctx = 1;
180 		return IAVF_VECTOR_CTX_PATH;
181 	}
182 
183 	/**
184 	 * Vlan tci needs to be inserted via ctx desc, if the vlan_flag is L2TAG2.
185 	 * Tunneling parameters and other fields need be configured in ctx desc
186 	 * if the outer checksum offload is enabled.
187 	 */
188 	if (txq->offloads & (IAVF_TX_VECTOR_OFFLOAD | IAVF_TX_VECTOR_OFFLOAD_CTX)) {
189 		if (txq->offloads & IAVF_TX_VECTOR_OFFLOAD_CTX) {
190 			if (txq->vlan_flag == IAVF_TX_FLAGS_VLAN_TAG_LOC_L2TAG2) {
191 				txq->use_ctx = 1;
192 				return IAVF_VECTOR_CTX_OFFLOAD_PATH;
193 			} else {
194 				return -1;
195 			}
196 		} else {
197 			return IAVF_VECTOR_OFFLOAD_PATH;
198 		}
199 	} else {
200 		return IAVF_VECTOR_PATH;
201 	}
202 }
203 
204 static inline int
205 iavf_rx_vec_dev_check_default(struct rte_eth_dev *dev)
206 {
207 	int i;
208 	struct iavf_rx_queue *rxq;
209 	int ret;
210 	int result = 0;
211 
212 	for (i = 0; i < dev->data->nb_rx_queues; i++) {
213 		rxq = dev->data->rx_queues[i];
214 		ret = iavf_rx_vec_queue_default(rxq);
215 
216 		if (ret < 0)
217 			return -1;
218 		if (ret > result)
219 			result = ret;
220 	}
221 
222 	return result;
223 }
224 
225 static inline int
226 iavf_tx_vec_dev_check_default(struct rte_eth_dev *dev)
227 {
228 	int i;
229 	struct ci_tx_queue *txq;
230 	int ret;
231 	int result = 0;
232 
233 	for (i = 0; i < dev->data->nb_tx_queues; i++) {
234 		txq = dev->data->tx_queues[i];
235 		ret = iavf_tx_vec_queue_default(txq);
236 
237 		if (ret < 0)
238 			return -1;
239 		if (ret > result)
240 			result = ret;
241 	}
242 
243 	return result;
244 }
245 
246 /******************************************************************************
247  * If user knows a specific offload is not enabled by APP,
248  * the macro can be commented to save the effort of fast path.
249  * Currently below 2 features are supported in TX path,
250  * 1, checksum offload
251  * 2, VLAN/QINQ insertion
252  ******************************************************************************/
253 #define IAVF_TX_CSUM_OFFLOAD
254 #define IAVF_TX_VLAN_QINQ_OFFLOAD
255 
256 static __rte_always_inline void
257 iavf_txd_enable_offload(__rte_unused struct rte_mbuf *tx_pkt,
258 			uint64_t *txd_hi)
259 {
260 #if defined(IAVF_TX_CSUM_OFFLOAD) || defined(IAVF_TX_VLAN_QINQ_OFFLOAD)
261 	uint64_t ol_flags = tx_pkt->ol_flags;
262 #endif
263 	uint32_t td_cmd = 0;
264 #ifdef IAVF_TX_CSUM_OFFLOAD
265 	uint32_t td_offset = 0;
266 #endif
267 
268 #ifdef IAVF_TX_CSUM_OFFLOAD
269 	/* Set MACLEN */
270 	if (ol_flags & RTE_MBUF_F_TX_TUNNEL_MASK)
271 		td_offset |= (tx_pkt->outer_l2_len >> 1)
272 			<< IAVF_TX_DESC_LENGTH_MACLEN_SHIFT;
273 	else
274 		td_offset |= (tx_pkt->l2_len >> 1)
275 			<< IAVF_TX_DESC_LENGTH_MACLEN_SHIFT;
276 
277 	/* Enable L3 checksum offloads */
278 	if (ol_flags & RTE_MBUF_F_TX_IP_CKSUM) {
279 		if (ol_flags & RTE_MBUF_F_TX_IPV4) {
280 			td_cmd |= IAVF_TX_DESC_CMD_IIPT_IPV4_CSUM;
281 			td_offset |= (tx_pkt->l3_len >> 2) <<
282 				     IAVF_TX_DESC_LENGTH_IPLEN_SHIFT;
283 		}
284 	} else if (ol_flags & RTE_MBUF_F_TX_IPV4) {
285 		td_cmd |= IAVF_TX_DESC_CMD_IIPT_IPV4;
286 		td_offset |= (tx_pkt->l3_len >> 2) <<
287 			     IAVF_TX_DESC_LENGTH_IPLEN_SHIFT;
288 	} else if (ol_flags & RTE_MBUF_F_TX_IPV6) {
289 		td_cmd |= IAVF_TX_DESC_CMD_IIPT_IPV6;
290 		td_offset |= (tx_pkt->l3_len >> 2) <<
291 			     IAVF_TX_DESC_LENGTH_IPLEN_SHIFT;
292 	}
293 
294 	/* Enable L4 checksum offloads */
295 	switch (ol_flags & RTE_MBUF_F_TX_L4_MASK) {
296 	case RTE_MBUF_F_TX_TCP_CKSUM:
297 		td_cmd |= IAVF_TX_DESC_CMD_L4T_EOFT_TCP;
298 		td_offset |= (sizeof(struct rte_tcp_hdr) >> 2) <<
299 			     IAVF_TX_DESC_LENGTH_L4_FC_LEN_SHIFT;
300 		break;
301 	case RTE_MBUF_F_TX_SCTP_CKSUM:
302 		td_cmd |= IAVF_TX_DESC_CMD_L4T_EOFT_SCTP;
303 		td_offset |= (sizeof(struct rte_sctp_hdr) >> 2) <<
304 			     IAVF_TX_DESC_LENGTH_L4_FC_LEN_SHIFT;
305 		break;
306 	case RTE_MBUF_F_TX_UDP_CKSUM:
307 		td_cmd |= IAVF_TX_DESC_CMD_L4T_EOFT_UDP;
308 		td_offset |= (sizeof(struct rte_udp_hdr) >> 2) <<
309 			     IAVF_TX_DESC_LENGTH_L4_FC_LEN_SHIFT;
310 		break;
311 	default:
312 		break;
313 	}
314 
315 	*txd_hi |= ((uint64_t)td_offset) << IAVF_TXD_QW1_OFFSET_SHIFT;
316 #endif
317 
318 #ifdef IAVF_TX_VLAN_QINQ_OFFLOAD
319 	if (ol_flags & (RTE_MBUF_F_TX_VLAN | RTE_MBUF_F_TX_QINQ)) {
320 		td_cmd |= IAVF_TX_DESC_CMD_IL2TAG1;
321 		*txd_hi |= ((uint64_t)tx_pkt->vlan_tci <<
322 			    IAVF_TXD_QW1_L2TAG1_SHIFT);
323 	}
324 #endif
325 
326 	*txd_hi |= ((uint64_t)td_cmd) << IAVF_TXD_QW1_CMD_SHIFT;
327 }
328 
329 #ifdef RTE_ARCH_X86
330 static __rte_always_inline void
331 iavf_rxq_rearm_common(struct iavf_rx_queue *rxq, __rte_unused bool avx512)
332 {
333 	int i;
334 	uint16_t rx_id;
335 	volatile union iavf_rx_desc *rxdp;
336 	struct rte_mbuf **rxp = &rxq->sw_ring[rxq->rxrearm_start];
337 
338 	rxdp = rxq->rx_ring + rxq->rxrearm_start;
339 
340 	/* Pull 'n' more MBUFs into the software ring */
341 	if (rte_mempool_get_bulk(rxq->mp,
342 				 (void *)rxp,
343 				 IAVF_RXQ_REARM_THRESH) < 0) {
344 		if (rxq->rxrearm_nb + IAVF_RXQ_REARM_THRESH >=
345 		    rxq->nb_rx_desc) {
346 			__m128i dma_addr0;
347 
348 			dma_addr0 = _mm_setzero_si128();
349 			for (i = 0; i < IAVF_VPMD_DESCS_PER_LOOP; i++) {
350 				rxp[i] = &rxq->fake_mbuf;
351 				_mm_store_si128(RTE_CAST_PTR(__m128i *, &rxdp[i].read),
352 						dma_addr0);
353 			}
354 		}
355 		rte_eth_devices[rxq->port_id].data->rx_mbuf_alloc_failed +=
356 			IAVF_RXQ_REARM_THRESH;
357 		return;
358 	}
359 
360 #ifndef RTE_LIBRTE_IAVF_16BYTE_RX_DESC
361 	struct rte_mbuf *mb0, *mb1;
362 	__m128i dma_addr0, dma_addr1;
363 	__m128i hdr_room = _mm_set_epi64x(RTE_PKTMBUF_HEADROOM,
364 			RTE_PKTMBUF_HEADROOM);
365 	/* Initialize the mbufs in vector, process 2 mbufs in one loop */
366 	for (i = 0; i < IAVF_RXQ_REARM_THRESH; i += 2, rxp += 2) {
367 		__m128i vaddr0, vaddr1;
368 
369 		mb0 = rxp[0];
370 		mb1 = rxp[1];
371 
372 		/* load buf_addr(lo 64bit) and buf_iova(hi 64bit) */
373 		RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, buf_iova) !=
374 				offsetof(struct rte_mbuf, buf_addr) + 8);
375 		vaddr0 = _mm_loadu_si128((__m128i *)&mb0->buf_addr);
376 		vaddr1 = _mm_loadu_si128((__m128i *)&mb1->buf_addr);
377 
378 		/* convert pa to dma_addr hdr/data */
379 		dma_addr0 = _mm_unpackhi_epi64(vaddr0, vaddr0);
380 		dma_addr1 = _mm_unpackhi_epi64(vaddr1, vaddr1);
381 
382 		/* add headroom to pa values */
383 		dma_addr0 = _mm_add_epi64(dma_addr0, hdr_room);
384 		dma_addr1 = _mm_add_epi64(dma_addr1, hdr_room);
385 
386 		/* flush desc with pa dma_addr */
387 		_mm_store_si128(RTE_CAST_PTR(__m128i *, &rxdp++->read), dma_addr0);
388 		_mm_store_si128(RTE_CAST_PTR(__m128i *, &rxdp++->read), dma_addr1);
389 	}
390 #else
391 #ifdef CC_AVX512_SUPPORT
392 	if (avx512) {
393 		struct rte_mbuf *mb0, *mb1, *mb2, *mb3;
394 		struct rte_mbuf *mb4, *mb5, *mb6, *mb7;
395 		__m512i dma_addr0_3, dma_addr4_7;
396 		__m512i hdr_room = _mm512_set1_epi64(RTE_PKTMBUF_HEADROOM);
397 		/* Initialize the mbufs in vector, process 8 mbufs in one loop */
398 		for (i = 0; i < IAVF_RXQ_REARM_THRESH;
399 				i += 8, rxp += 8, rxdp += 8) {
400 			__m128i vaddr0, vaddr1, vaddr2, vaddr3;
401 			__m128i vaddr4, vaddr5, vaddr6, vaddr7;
402 			__m256i vaddr0_1, vaddr2_3;
403 			__m256i vaddr4_5, vaddr6_7;
404 			__m512i vaddr0_3, vaddr4_7;
405 
406 			mb0 = rxp[0];
407 			mb1 = rxp[1];
408 			mb2 = rxp[2];
409 			mb3 = rxp[3];
410 			mb4 = rxp[4];
411 			mb5 = rxp[5];
412 			mb6 = rxp[6];
413 			mb7 = rxp[7];
414 
415 			/* load buf_addr(lo 64bit) and buf_iova(hi 64bit) */
416 			RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, buf_iova) !=
417 					offsetof(struct rte_mbuf, buf_addr) + 8);
418 			vaddr0 = _mm_loadu_si128((__m128i *)&mb0->buf_addr);
419 			vaddr1 = _mm_loadu_si128((__m128i *)&mb1->buf_addr);
420 			vaddr2 = _mm_loadu_si128((__m128i *)&mb2->buf_addr);
421 			vaddr3 = _mm_loadu_si128((__m128i *)&mb3->buf_addr);
422 			vaddr4 = _mm_loadu_si128((__m128i *)&mb4->buf_addr);
423 			vaddr5 = _mm_loadu_si128((__m128i *)&mb5->buf_addr);
424 			vaddr6 = _mm_loadu_si128((__m128i *)&mb6->buf_addr);
425 			vaddr7 = _mm_loadu_si128((__m128i *)&mb7->buf_addr);
426 
427 			/**
428 			 * merge 0 & 1, by casting 0 to 256-bit and inserting 1
429 			 * into the high lanes. Similarly for 2 & 3, and so on.
430 			 */
431 			vaddr0_1 =
432 				_mm256_inserti128_si256(_mm256_castsi128_si256(vaddr0),
433 							vaddr1, 1);
434 			vaddr2_3 =
435 				_mm256_inserti128_si256(_mm256_castsi128_si256(vaddr2),
436 							vaddr3, 1);
437 			vaddr4_5 =
438 				_mm256_inserti128_si256(_mm256_castsi128_si256(vaddr4),
439 							vaddr5, 1);
440 			vaddr6_7 =
441 				_mm256_inserti128_si256(_mm256_castsi128_si256(vaddr6),
442 							vaddr7, 1);
443 			vaddr0_3 =
444 				_mm512_inserti64x4(_mm512_castsi256_si512(vaddr0_1),
445 							vaddr2_3, 1);
446 			vaddr4_7 =
447 				_mm512_inserti64x4(_mm512_castsi256_si512(vaddr4_5),
448 							vaddr6_7, 1);
449 
450 			/* convert pa to dma_addr hdr/data */
451 			dma_addr0_3 = _mm512_unpackhi_epi64(vaddr0_3, vaddr0_3);
452 			dma_addr4_7 = _mm512_unpackhi_epi64(vaddr4_7, vaddr4_7);
453 
454 			/* add headroom to pa values */
455 			dma_addr0_3 = _mm512_add_epi64(dma_addr0_3, hdr_room);
456 			dma_addr4_7 = _mm512_add_epi64(dma_addr4_7, hdr_room);
457 
458 			/* flush desc with pa dma_addr */
459 			_mm512_store_si512((__m512i *)&rxdp->read, dma_addr0_3);
460 			_mm512_store_si512((__m512i *)&(rxdp + 4)->read, dma_addr4_7);
461 		}
462 	} else
463 #endif
464 	{
465 		struct rte_mbuf *mb0, *mb1, *mb2, *mb3;
466 		__m256i dma_addr0_1, dma_addr2_3;
467 		__m256i hdr_room = _mm256_set1_epi64x(RTE_PKTMBUF_HEADROOM);
468 		/* Initialize the mbufs in vector, process 4 mbufs in one loop */
469 		for (i = 0; i < IAVF_RXQ_REARM_THRESH;
470 				i += 4, rxp += 4, rxdp += 4) {
471 			__m128i vaddr0, vaddr1, vaddr2, vaddr3;
472 			__m256i vaddr0_1, vaddr2_3;
473 
474 			mb0 = rxp[0];
475 			mb1 = rxp[1];
476 			mb2 = rxp[2];
477 			mb3 = rxp[3];
478 
479 			/* load buf_addr(lo 64bit) and buf_iova(hi 64bit) */
480 			RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, buf_iova) !=
481 					offsetof(struct rte_mbuf, buf_addr) + 8);
482 			vaddr0 = _mm_loadu_si128((__m128i *)&mb0->buf_addr);
483 			vaddr1 = _mm_loadu_si128((__m128i *)&mb1->buf_addr);
484 			vaddr2 = _mm_loadu_si128((__m128i *)&mb2->buf_addr);
485 			vaddr3 = _mm_loadu_si128((__m128i *)&mb3->buf_addr);
486 
487 			/**
488 			 * merge 0 & 1, by casting 0 to 256-bit and inserting 1
489 			 * into the high lanes. Similarly for 2 & 3
490 			 */
491 			vaddr0_1 =
492 				_mm256_inserti128_si256(_mm256_castsi128_si256(vaddr0),
493 							vaddr1, 1);
494 			vaddr2_3 =
495 				_mm256_inserti128_si256(_mm256_castsi128_si256(vaddr2),
496 							vaddr3, 1);
497 
498 			/* convert pa to dma_addr hdr/data */
499 			dma_addr0_1 = _mm256_unpackhi_epi64(vaddr0_1, vaddr0_1);
500 			dma_addr2_3 = _mm256_unpackhi_epi64(vaddr2_3, vaddr2_3);
501 
502 			/* add headroom to pa values */
503 			dma_addr0_1 = _mm256_add_epi64(dma_addr0_1, hdr_room);
504 			dma_addr2_3 = _mm256_add_epi64(dma_addr2_3, hdr_room);
505 
506 			/* flush desc with pa dma_addr */
507 			_mm256_store_si256((__m256i *)&rxdp->read, dma_addr0_1);
508 			_mm256_store_si256((__m256i *)&(rxdp + 2)->read, dma_addr2_3);
509 		}
510 	}
511 
512 #endif
513 
514 	rxq->rxrearm_start += IAVF_RXQ_REARM_THRESH;
515 	if (rxq->rxrearm_start >= rxq->nb_rx_desc)
516 		rxq->rxrearm_start = 0;
517 
518 	rxq->rxrearm_nb -= IAVF_RXQ_REARM_THRESH;
519 
520 	rx_id = (uint16_t)((rxq->rxrearm_start == 0) ?
521 			     (rxq->nb_rx_desc - 1) : (rxq->rxrearm_start - 1));
522 
523 	/* Update the tail pointer on the NIC */
524 	IAVF_PCI_REG_WC_WRITE(rxq->qrx_tail, rx_id);
525 }
526 #endif
527 
528 #endif
529