xref: /dpdk/drivers/net/virtio/virtio_rxtx_simple.c (revision ebee5594a35e2af743ff03cde7d4bac67ac772f2)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright(c) 2010-2015 Intel Corporation. All rights reserved.
5  *   All rights reserved.
6  *
7  *   Redistribution and use in source and binary forms, with or without
8  *   modification, are permitted provided that the following conditions
9  *   are met:
10  *
11  *     * Redistributions of source code must retain the above copyright
12  *       notice, this list of conditions and the following disclaimer.
13  *     * Redistributions in binary form must reproduce the above copyright
14  *       notice, this list of conditions and the following disclaimer in
15  *       the documentation and/or other materials provided with the
16  *       distribution.
17  *     * Neither the name of Intel Corporation nor the names of its
18  *       contributors may be used to endorse or promote products derived
19  *       from this software without specific prior written permission.
20  *
21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include <stdint.h>
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <errno.h>
39 
40 #include <tmmintrin.h>
41 
42 #include <rte_cycles.h>
43 #include <rte_memory.h>
44 #include <rte_memzone.h>
45 #include <rte_branch_prediction.h>
46 #include <rte_mempool.h>
47 #include <rte_malloc.h>
48 #include <rte_mbuf.h>
49 #include <rte_ether.h>
50 #include <rte_ethdev.h>
51 #include <rte_prefetch.h>
52 #include <rte_string_fns.h>
53 #include <rte_errno.h>
54 #include <rte_byteorder.h>
55 
56 #include "virtio_logs.h"
57 #include "virtio_ethdev.h"
58 #include "virtqueue.h"
59 #include "virtio_rxtx.h"
60 
61 #define RTE_VIRTIO_VPMD_RX_BURST 32
62 #define RTE_VIRTIO_DESC_PER_LOOP 8
63 #define RTE_VIRTIO_VPMD_RX_REARM_THRESH RTE_VIRTIO_VPMD_RX_BURST
64 
65 #ifndef __INTEL_COMPILER
66 #pragma GCC diagnostic ignored "-Wcast-qual"
67 #endif
68 
69 int __attribute__((cold))
70 virtqueue_enqueue_recv_refill_simple(struct virtqueue *vq,
71 	struct rte_mbuf *cookie)
72 {
73 	struct vq_desc_extra *dxp;
74 	struct vring_desc *start_dp;
75 	uint16_t desc_idx;
76 
77 	desc_idx = vq->vq_avail_idx & (vq->vq_nentries - 1);
78 	dxp = &vq->vq_descx[desc_idx];
79 	dxp->cookie = (void *)cookie;
80 	vq->sw_ring[desc_idx] = cookie;
81 
82 	start_dp = vq->vq_ring.desc;
83 	start_dp[desc_idx].addr = MBUF_DATA_DMA_ADDR(cookie, vq->offset) -
84 				  vq->hw->vtnet_hdr_size;
85 	start_dp[desc_idx].len = cookie->buf_len -
86 		RTE_PKTMBUF_HEADROOM + vq->hw->vtnet_hdr_size;
87 
88 	vq->vq_free_cnt--;
89 	vq->vq_avail_idx++;
90 
91 	return 0;
92 }
93 
94 static inline void
95 virtio_rxq_rearm_vec(struct virtnet_rx *rxvq)
96 {
97 	int i;
98 	uint16_t desc_idx;
99 	struct rte_mbuf **sw_ring;
100 	struct vring_desc *start_dp;
101 	int ret;
102 	struct virtqueue *vq = rxvq->vq;
103 
104 	desc_idx = vq->vq_avail_idx & (vq->vq_nentries - 1);
105 	sw_ring = &vq->sw_ring[desc_idx];
106 	start_dp = &vq->vq_ring.desc[desc_idx];
107 
108 	ret = rte_mempool_get_bulk(rxvq->mpool, (void **)sw_ring,
109 		RTE_VIRTIO_VPMD_RX_REARM_THRESH);
110 	if (unlikely(ret)) {
111 		rte_eth_devices[rxvq->port_id].data->rx_mbuf_alloc_failed +=
112 			RTE_VIRTIO_VPMD_RX_REARM_THRESH;
113 		return;
114 	}
115 
116 	for (i = 0; i < RTE_VIRTIO_VPMD_RX_REARM_THRESH; i++) {
117 		uintptr_t p;
118 
119 		p = (uintptr_t)&sw_ring[i]->rearm_data;
120 		*(uint64_t *)p = rxvq->mbuf_initializer;
121 
122 		start_dp[i].addr =
123 			MBUF_DATA_DMA_ADDR(sw_ring[i], vq->offset) -
124 			vq->hw->vtnet_hdr_size;
125 		start_dp[i].len = sw_ring[i]->buf_len -
126 			RTE_PKTMBUF_HEADROOM + vq->hw->vtnet_hdr_size;
127 	}
128 
129 	vq->vq_avail_idx += RTE_VIRTIO_VPMD_RX_REARM_THRESH;
130 	vq->vq_free_cnt -= RTE_VIRTIO_VPMD_RX_REARM_THRESH;
131 	vq_update_avail_idx(vq);
132 }
133 
134 /* virtio vPMD receive routine, only accept(nb_pkts >= RTE_VIRTIO_DESC_PER_LOOP)
135  *
136  * This routine is for non-mergeable RX, one desc for each guest buffer.
137  * This routine is based on the RX ring layout optimization. Each entry in the
138  * avail ring points to the desc with the same index in the desc ring and this
139  * will never be changed in the driver.
140  *
141  * - nb_pkts < RTE_VIRTIO_DESC_PER_LOOP, just return no packet
142  */
143 uint16_t
144 virtio_recv_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
145 	uint16_t nb_pkts)
146 {
147 	struct virtnet_rx *rxvq = rx_queue;
148 	struct virtqueue *vq = rxvq->vq;
149 	uint16_t nb_used;
150 	uint16_t desc_idx;
151 	struct vring_used_elem *rused;
152 	struct rte_mbuf **sw_ring;
153 	struct rte_mbuf **sw_ring_end;
154 	uint16_t nb_pkts_received;
155 	__m128i shuf_msk1, shuf_msk2, len_adjust;
156 
157 	shuf_msk1 = _mm_set_epi8(
158 		0xFF, 0xFF, 0xFF, 0xFF,
159 		0xFF, 0xFF,		/* vlan tci */
160 		5, 4,			/* dat len */
161 		0xFF, 0xFF, 5, 4,	/* pkt len */
162 		0xFF, 0xFF, 0xFF, 0xFF	/* packet type */
163 
164 	);
165 
166 	shuf_msk2 = _mm_set_epi8(
167 		0xFF, 0xFF, 0xFF, 0xFF,
168 		0xFF, 0xFF,		/* vlan tci */
169 		13, 12,			/* dat len */
170 		0xFF, 0xFF, 13, 12,	/* pkt len */
171 		0xFF, 0xFF, 0xFF, 0xFF	/* packet type */
172 	);
173 
174 	/* Subtract the header length.
175 	*  In which case do we need the header length in used->len ?
176 	*/
177 	len_adjust = _mm_set_epi16(
178 		0, 0,
179 		0,
180 		(uint16_t)-vq->hw->vtnet_hdr_size,
181 		0, (uint16_t)-vq->hw->vtnet_hdr_size,
182 		0, 0);
183 
184 	if (unlikely(nb_pkts < RTE_VIRTIO_DESC_PER_LOOP))
185 		return 0;
186 
187 	nb_used = VIRTQUEUE_NUSED(vq);
188 
189 	rte_compiler_barrier();
190 
191 	if (unlikely(nb_used == 0))
192 		return 0;
193 
194 	nb_pkts = RTE_ALIGN_FLOOR(nb_pkts, RTE_VIRTIO_DESC_PER_LOOP);
195 	nb_used = RTE_MIN(nb_used, nb_pkts);
196 
197 	desc_idx = (uint16_t)(vq->vq_used_cons_idx & (vq->vq_nentries - 1));
198 	rused = &vq->vq_ring.used->ring[desc_idx];
199 	sw_ring  = &vq->sw_ring[desc_idx];
200 	sw_ring_end = &vq->sw_ring[vq->vq_nentries];
201 
202 	_mm_prefetch((const void *)rused, _MM_HINT_T0);
203 
204 	if (vq->vq_free_cnt >= RTE_VIRTIO_VPMD_RX_REARM_THRESH) {
205 		virtio_rxq_rearm_vec(rxvq);
206 		if (unlikely(virtqueue_kick_prepare(vq)))
207 			virtqueue_notify(vq);
208 	}
209 
210 	for (nb_pkts_received = 0;
211 		nb_pkts_received < nb_used;) {
212 		__m128i desc[RTE_VIRTIO_DESC_PER_LOOP / 2];
213 		__m128i mbp[RTE_VIRTIO_DESC_PER_LOOP / 2];
214 		__m128i pkt_mb[RTE_VIRTIO_DESC_PER_LOOP];
215 
216 		mbp[0] = _mm_loadu_si128((__m128i *)(sw_ring + 0));
217 		desc[0] = _mm_loadu_si128((__m128i *)(rused + 0));
218 		_mm_storeu_si128((__m128i *)&rx_pkts[0], mbp[0]);
219 
220 		mbp[1] = _mm_loadu_si128((__m128i *)(sw_ring + 2));
221 		desc[1] = _mm_loadu_si128((__m128i *)(rused + 2));
222 		_mm_storeu_si128((__m128i *)&rx_pkts[2], mbp[1]);
223 
224 		mbp[2] = _mm_loadu_si128((__m128i *)(sw_ring + 4));
225 		desc[2] = _mm_loadu_si128((__m128i *)(rused + 4));
226 		_mm_storeu_si128((__m128i *)&rx_pkts[4], mbp[2]);
227 
228 		mbp[3] = _mm_loadu_si128((__m128i *)(sw_ring + 6));
229 		desc[3] = _mm_loadu_si128((__m128i *)(rused + 6));
230 		_mm_storeu_si128((__m128i *)&rx_pkts[6], mbp[3]);
231 
232 		pkt_mb[1] = _mm_shuffle_epi8(desc[0], shuf_msk2);
233 		pkt_mb[0] = _mm_shuffle_epi8(desc[0], shuf_msk1);
234 		pkt_mb[1] = _mm_add_epi16(pkt_mb[1], len_adjust);
235 		pkt_mb[0] = _mm_add_epi16(pkt_mb[0], len_adjust);
236 		_mm_storeu_si128((void *)&rx_pkts[1]->rx_descriptor_fields1,
237 			pkt_mb[1]);
238 		_mm_storeu_si128((void *)&rx_pkts[0]->rx_descriptor_fields1,
239 			pkt_mb[0]);
240 
241 		pkt_mb[3] = _mm_shuffle_epi8(desc[1], shuf_msk2);
242 		pkt_mb[2] = _mm_shuffle_epi8(desc[1], shuf_msk1);
243 		pkt_mb[3] = _mm_add_epi16(pkt_mb[3], len_adjust);
244 		pkt_mb[2] = _mm_add_epi16(pkt_mb[2], len_adjust);
245 		_mm_storeu_si128((void *)&rx_pkts[3]->rx_descriptor_fields1,
246 			pkt_mb[3]);
247 		_mm_storeu_si128((void *)&rx_pkts[2]->rx_descriptor_fields1,
248 			pkt_mb[2]);
249 
250 		pkt_mb[5] = _mm_shuffle_epi8(desc[2], shuf_msk2);
251 		pkt_mb[4] = _mm_shuffle_epi8(desc[2], shuf_msk1);
252 		pkt_mb[5] = _mm_add_epi16(pkt_mb[5], len_adjust);
253 		pkt_mb[4] = _mm_add_epi16(pkt_mb[4], len_adjust);
254 		_mm_storeu_si128((void *)&rx_pkts[5]->rx_descriptor_fields1,
255 			pkt_mb[5]);
256 		_mm_storeu_si128((void *)&rx_pkts[4]->rx_descriptor_fields1,
257 			pkt_mb[4]);
258 
259 		pkt_mb[7] = _mm_shuffle_epi8(desc[3], shuf_msk2);
260 		pkt_mb[6] = _mm_shuffle_epi8(desc[3], shuf_msk1);
261 		pkt_mb[7] = _mm_add_epi16(pkt_mb[7], len_adjust);
262 		pkt_mb[6] = _mm_add_epi16(pkt_mb[6], len_adjust);
263 		_mm_storeu_si128((void *)&rx_pkts[7]->rx_descriptor_fields1,
264 			pkt_mb[7]);
265 		_mm_storeu_si128((void *)&rx_pkts[6]->rx_descriptor_fields1,
266 			pkt_mb[6]);
267 
268 		if (unlikely(nb_used <= RTE_VIRTIO_DESC_PER_LOOP)) {
269 			if (sw_ring + nb_used <= sw_ring_end)
270 				nb_pkts_received += nb_used;
271 			else
272 				nb_pkts_received += sw_ring_end - sw_ring;
273 			break;
274 		} else {
275 			if (unlikely(sw_ring + RTE_VIRTIO_DESC_PER_LOOP >=
276 				sw_ring_end)) {
277 				nb_pkts_received += sw_ring_end - sw_ring;
278 				break;
279 			} else {
280 				nb_pkts_received += RTE_VIRTIO_DESC_PER_LOOP;
281 
282 				rx_pkts += RTE_VIRTIO_DESC_PER_LOOP;
283 				sw_ring += RTE_VIRTIO_DESC_PER_LOOP;
284 				rused   += RTE_VIRTIO_DESC_PER_LOOP;
285 				nb_used -= RTE_VIRTIO_DESC_PER_LOOP;
286 			}
287 		}
288 	}
289 
290 	vq->vq_used_cons_idx += nb_pkts_received;
291 	vq->vq_free_cnt += nb_pkts_received;
292 	rxvq->stats.packets += nb_pkts_received;
293 	return nb_pkts_received;
294 }
295 
296 #define VIRTIO_TX_FREE_THRESH 32
297 #define VIRTIO_TX_MAX_FREE_BUF_SZ 32
298 #define VIRTIO_TX_FREE_NR 32
299 /* TODO: vq->tx_free_cnt could mean num of free slots so we could avoid shift */
300 static inline void
301 virtio_xmit_cleanup(struct virtqueue *vq)
302 {
303 	uint16_t i, desc_idx;
304 	int nb_free = 0;
305 	struct rte_mbuf *m, *free[VIRTIO_TX_MAX_FREE_BUF_SZ];
306 
307 	desc_idx = (uint16_t)(vq->vq_used_cons_idx &
308 		   ((vq->vq_nentries >> 1) - 1));
309 	m = (struct rte_mbuf *)vq->vq_descx[desc_idx++].cookie;
310 	m = __rte_pktmbuf_prefree_seg(m);
311 	if (likely(m != NULL)) {
312 		free[0] = m;
313 		nb_free = 1;
314 		for (i = 1; i < VIRTIO_TX_FREE_NR; i++) {
315 			m = (struct rte_mbuf *)vq->vq_descx[desc_idx++].cookie;
316 			m = __rte_pktmbuf_prefree_seg(m);
317 			if (likely(m != NULL)) {
318 				if (likely(m->pool == free[0]->pool))
319 					free[nb_free++] = m;
320 				else {
321 					rte_mempool_put_bulk(free[0]->pool,
322 						(void **)free, nb_free);
323 					free[0] = m;
324 					nb_free = 1;
325 				}
326 			}
327 		}
328 		rte_mempool_put_bulk(free[0]->pool, (void **)free, nb_free);
329 	} else {
330 		for (i = 1; i < VIRTIO_TX_FREE_NR; i++) {
331 			m = (struct rte_mbuf *)vq->vq_descx[desc_idx++].cookie;
332 			m = __rte_pktmbuf_prefree_seg(m);
333 			if (m != NULL)
334 				rte_mempool_put(m->pool, m);
335 		}
336 	}
337 
338 	vq->vq_used_cons_idx += VIRTIO_TX_FREE_NR;
339 	vq->vq_free_cnt += (VIRTIO_TX_FREE_NR << 1);
340 }
341 
342 uint16_t
343 virtio_xmit_pkts_simple(void *tx_queue, struct rte_mbuf **tx_pkts,
344 	uint16_t nb_pkts)
345 {
346 	struct virtnet_tx *txvq = tx_queue;
347 	struct virtqueue *vq = txvq->vq;
348 	uint16_t nb_used;
349 	uint16_t desc_idx;
350 	struct vring_desc *start_dp;
351 	uint16_t nb_tail, nb_commit;
352 	int i;
353 	uint16_t desc_idx_max = (vq->vq_nentries >> 1) - 1;
354 
355 	nb_used = VIRTQUEUE_NUSED(vq);
356 	rte_compiler_barrier();
357 
358 	if (nb_used >= VIRTIO_TX_FREE_THRESH)
359 		virtio_xmit_cleanup(vq);
360 
361 	nb_commit = nb_pkts = RTE_MIN((vq->vq_free_cnt >> 1), nb_pkts);
362 	desc_idx = (uint16_t)(vq->vq_avail_idx & desc_idx_max);
363 	start_dp = vq->vq_ring.desc;
364 	nb_tail = (uint16_t) (desc_idx_max + 1 - desc_idx);
365 
366 	if (nb_commit >= nb_tail) {
367 		for (i = 0; i < nb_tail; i++)
368 			vq->vq_descx[desc_idx + i].cookie = tx_pkts[i];
369 		for (i = 0; i < nb_tail; i++) {
370 			start_dp[desc_idx].addr =
371 				MBUF_DATA_DMA_ADDR(*tx_pkts, vq->offset);
372 			start_dp[desc_idx].len = (*tx_pkts)->pkt_len;
373 			tx_pkts++;
374 			desc_idx++;
375 		}
376 		nb_commit -= nb_tail;
377 		desc_idx = 0;
378 	}
379 	for (i = 0; i < nb_commit; i++)
380 		vq->vq_descx[desc_idx + i].cookie = tx_pkts[i];
381 	for (i = 0; i < nb_commit; i++) {
382 		start_dp[desc_idx].addr =
383 			MBUF_DATA_DMA_ADDR(*tx_pkts, vq->offset);
384 		start_dp[desc_idx].len = (*tx_pkts)->pkt_len;
385 		tx_pkts++;
386 		desc_idx++;
387 	}
388 
389 	rte_compiler_barrier();
390 
391 	vq->vq_free_cnt -= (uint16_t)(nb_pkts << 1);
392 	vq->vq_avail_idx += nb_pkts;
393 	vq->vq_ring.avail->idx = vq->vq_avail_idx;
394 	txvq->stats.packets += nb_pkts;
395 
396 	if (likely(nb_pkts)) {
397 		if (unlikely(virtqueue_kick_prepare(vq)))
398 			virtqueue_notify(vq);
399 	}
400 
401 	return nb_pkts;
402 }
403 
404 int __attribute__((cold))
405 virtio_rxq_vec_setup(struct virtnet_rx *rxq)
406 {
407 	uintptr_t p;
408 	struct rte_mbuf mb_def = { .buf_addr = 0 }; /* zeroed mbuf */
409 
410 	mb_def.nb_segs = 1;
411 	mb_def.data_off = RTE_PKTMBUF_HEADROOM;
412 	mb_def.port = rxq->port_id;
413 	rte_mbuf_refcnt_set(&mb_def, 1);
414 
415 	/* prevent compiler reordering: rearm_data covers previous fields */
416 	rte_compiler_barrier();
417 	p = (uintptr_t)&mb_def.rearm_data;
418 	rxq->mbuf_initializer = *(uint64_t *)p;
419 
420 	return 0;
421 }
422