xref: /dpdk/drivers/net/sfc/sfc_ef10_tx.c (revision 089e5ed727a15da2729cfee9b63533dd120bd04c)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  *
3  * Copyright (c) 2016-2018 Solarflare Communications Inc.
4  * All rights reserved.
5  *
6  * This software was jointly developed between OKTET Labs (under contract
7  * for Solarflare) and Solarflare Communications, Inc.
8  */
9 
10 #include <stdbool.h>
11 
12 #include <rte_mbuf.h>
13 #include <rte_io.h>
14 #include <rte_ip.h>
15 #include <rte_tcp.h>
16 
17 #include "efx.h"
18 #include "efx_types.h"
19 #include "efx_regs.h"
20 #include "efx_regs_ef10.h"
21 
22 #include "sfc_dp_tx.h"
23 #include "sfc_tweak.h"
24 #include "sfc_kvargs.h"
25 #include "sfc_ef10.h"
26 #include "sfc_tso.h"
27 
28 #define sfc_ef10_tx_err(dpq, ...) \
29 	SFC_DP_LOG(SFC_KVARG_DATAPATH_EF10, ERR, dpq, __VA_ARGS__)
30 
31 /** Maximum length of the DMA descriptor data */
32 #define SFC_EF10_TX_DMA_DESC_LEN_MAX \
33 	((1u << ESF_DZ_TX_KER_BYTE_CNT_WIDTH) - 1)
34 
35 /**
36  * Maximum number of descriptors/buffers in the Tx ring.
37  * It should guarantee that corresponding event queue never overfill.
38  * EF10 native datapath uses event queue of the same size as Tx queue.
39  * Maximum number of events on datapath can be estimated as number of
40  * Tx queue entries (one event per Tx buffer in the worst case) plus
41  * Tx error and flush events.
42  */
43 #define SFC_EF10_TXQ_LIMIT(_ndesc) \
44 	((_ndesc) - 1 /* head must not step on tail */ - \
45 	 (SFC_EF10_EV_PER_CACHE_LINE - 1) /* max unused EvQ entries */ - \
46 	 1 /* Rx error */ - 1 /* flush */)
47 
48 struct sfc_ef10_tx_sw_desc {
49 	struct rte_mbuf			*mbuf;
50 };
51 
52 struct sfc_ef10_txq {
53 	unsigned int			flags;
54 #define SFC_EF10_TXQ_STARTED		0x1
55 #define SFC_EF10_TXQ_NOT_RUNNING	0x2
56 #define SFC_EF10_TXQ_EXCEPTION		0x4
57 
58 	unsigned int			ptr_mask;
59 	unsigned int			added;
60 	unsigned int			completed;
61 	unsigned int			max_fill_level;
62 	unsigned int			free_thresh;
63 	unsigned int			evq_read_ptr;
64 	struct sfc_ef10_tx_sw_desc	*sw_ring;
65 	efx_qword_t			*txq_hw_ring;
66 	volatile void			*doorbell;
67 	efx_qword_t			*evq_hw_ring;
68 	uint8_t				*tsoh;
69 	rte_iova_t			tsoh_iova;
70 	uint16_t			tso_tcp_header_offset_limit;
71 
72 	/* Datapath transmit queue anchor */
73 	struct sfc_dp_txq		dp;
74 };
75 
76 static inline struct sfc_ef10_txq *
77 sfc_ef10_txq_by_dp_txq(struct sfc_dp_txq *dp_txq)
78 {
79 	return container_of(dp_txq, struct sfc_ef10_txq, dp);
80 }
81 
82 static bool
83 sfc_ef10_tx_get_event(struct sfc_ef10_txq *txq, efx_qword_t *tx_ev)
84 {
85 	volatile efx_qword_t *evq_hw_ring = txq->evq_hw_ring;
86 
87 	/*
88 	 * Exception flag is set when reap is done.
89 	 * It is never done twice per packet burst get and absence of
90 	 * the flag is checked on burst get entry.
91 	 */
92 	SFC_ASSERT((txq->flags & SFC_EF10_TXQ_EXCEPTION) == 0);
93 
94 	*tx_ev = evq_hw_ring[txq->evq_read_ptr & txq->ptr_mask];
95 
96 	if (!sfc_ef10_ev_present(*tx_ev))
97 		return false;
98 
99 	if (unlikely(EFX_QWORD_FIELD(*tx_ev, FSF_AZ_EV_CODE) !=
100 		     FSE_AZ_EV_CODE_TX_EV)) {
101 		/*
102 		 * Do not move read_ptr to keep the event for exception
103 		 * handling by the control path.
104 		 */
105 		txq->flags |= SFC_EF10_TXQ_EXCEPTION;
106 		sfc_ef10_tx_err(&txq->dp.dpq,
107 				"TxQ exception at EvQ read ptr %#x",
108 				txq->evq_read_ptr);
109 		return false;
110 	}
111 
112 	txq->evq_read_ptr++;
113 	return true;
114 }
115 
116 static unsigned int
117 sfc_ef10_tx_process_events(struct sfc_ef10_txq *txq)
118 {
119 	const unsigned int curr_done = txq->completed - 1;
120 	unsigned int anew_done = curr_done;
121 	efx_qword_t tx_ev;
122 
123 	while (sfc_ef10_tx_get_event(txq, &tx_ev)) {
124 		/*
125 		 * DROP_EVENT is an internal to the NIC, software should
126 		 * never see it and, therefore, may ignore it.
127 		 */
128 
129 		/* Update the latest done descriptor */
130 		anew_done = EFX_QWORD_FIELD(tx_ev, ESF_DZ_TX_DESCR_INDX);
131 	}
132 	return (anew_done - curr_done) & txq->ptr_mask;
133 }
134 
135 static void
136 sfc_ef10_tx_reap(struct sfc_ef10_txq *txq)
137 {
138 	const unsigned int old_read_ptr = txq->evq_read_ptr;
139 	const unsigned int ptr_mask = txq->ptr_mask;
140 	unsigned int completed = txq->completed;
141 	unsigned int pending = completed;
142 
143 	pending += sfc_ef10_tx_process_events(txq);
144 
145 	if (pending != completed) {
146 		struct rte_mbuf *bulk[SFC_TX_REAP_BULK_SIZE];
147 		unsigned int nb = 0;
148 
149 		do {
150 			struct sfc_ef10_tx_sw_desc *txd;
151 			struct rte_mbuf *m;
152 
153 			txd = &txq->sw_ring[completed & ptr_mask];
154 			if (txd->mbuf == NULL)
155 				continue;
156 
157 			m = rte_pktmbuf_prefree_seg(txd->mbuf);
158 			txd->mbuf = NULL;
159 			if (m == NULL)
160 				continue;
161 
162 			if ((nb == RTE_DIM(bulk)) ||
163 			    ((nb != 0) && (m->pool != bulk[0]->pool))) {
164 				rte_mempool_put_bulk(bulk[0]->pool,
165 						     (void *)bulk, nb);
166 				nb = 0;
167 			}
168 
169 			bulk[nb++] = m;
170 		} while (++completed != pending);
171 
172 		if (nb != 0)
173 			rte_mempool_put_bulk(bulk[0]->pool, (void *)bulk, nb);
174 
175 		txq->completed = completed;
176 	}
177 
178 	sfc_ef10_ev_qclear(txq->evq_hw_ring, ptr_mask, old_read_ptr,
179 			   txq->evq_read_ptr);
180 }
181 
182 static void
183 sfc_ef10_tx_qdesc_dma_create(rte_iova_t addr, uint16_t size, bool eop,
184 			     efx_qword_t *edp)
185 {
186 	EFX_POPULATE_QWORD_4(*edp,
187 			     ESF_DZ_TX_KER_TYPE, 0,
188 			     ESF_DZ_TX_KER_CONT, !eop,
189 			     ESF_DZ_TX_KER_BYTE_CNT, size,
190 			     ESF_DZ_TX_KER_BUF_ADDR, addr);
191 }
192 
193 static void
194 sfc_ef10_tx_qdesc_tso2_create(struct sfc_ef10_txq * const txq,
195 			      unsigned int added, uint16_t ipv4_id,
196 			      uint16_t outer_ipv4_id, uint32_t tcp_seq,
197 			      uint16_t tcp_mss)
198 {
199 	EFX_POPULATE_QWORD_5(txq->txq_hw_ring[added & txq->ptr_mask],
200 			    ESF_DZ_TX_DESC_IS_OPT, 1,
201 			    ESF_DZ_TX_OPTION_TYPE,
202 			    ESE_DZ_TX_OPTION_DESC_TSO,
203 			    ESF_DZ_TX_TSO_OPTION_TYPE,
204 			    ESE_DZ_TX_TSO_OPTION_DESC_FATSO2A,
205 			    ESF_DZ_TX_TSO_IP_ID, ipv4_id,
206 			    ESF_DZ_TX_TSO_TCP_SEQNO, tcp_seq);
207 	EFX_POPULATE_QWORD_5(txq->txq_hw_ring[(added + 1) & txq->ptr_mask],
208 			    ESF_DZ_TX_DESC_IS_OPT, 1,
209 			    ESF_DZ_TX_OPTION_TYPE,
210 			    ESE_DZ_TX_OPTION_DESC_TSO,
211 			    ESF_DZ_TX_TSO_OPTION_TYPE,
212 			    ESE_DZ_TX_TSO_OPTION_DESC_FATSO2B,
213 			    ESF_DZ_TX_TSO_TCP_MSS, tcp_mss,
214 			    ESF_DZ_TX_TSO_OUTER_IPID, outer_ipv4_id);
215 }
216 
217 static inline void
218 sfc_ef10_tx_qpush(struct sfc_ef10_txq *txq, unsigned int added,
219 		  unsigned int pushed)
220 {
221 	efx_qword_t desc;
222 	efx_oword_t oword;
223 
224 	/*
225 	 * This improves performance by pushing a TX descriptor at the same
226 	 * time as the doorbell. The descriptor must be added to the TXQ,
227 	 * so that can be used if the hardware decides not to use the pushed
228 	 * descriptor.
229 	 */
230 	desc.eq_u64[0] = txq->txq_hw_ring[pushed & txq->ptr_mask].eq_u64[0];
231 	EFX_POPULATE_OWORD_3(oword,
232 		ERF_DZ_TX_DESC_WPTR, added & txq->ptr_mask,
233 		ERF_DZ_TX_DESC_HWORD, EFX_QWORD_FIELD(desc, EFX_DWORD_1),
234 		ERF_DZ_TX_DESC_LWORD, EFX_QWORD_FIELD(desc, EFX_DWORD_0));
235 
236 	/* DMA sync to device is not required */
237 
238 	/*
239 	 * rte_io_wmb() which guarantees that the STORE operations
240 	 * (i.e. Tx and event descriptor updates) that precede
241 	 * the rte_io_wmb() call are visible to NIC before the STORE
242 	 * operations that follow it (i.e. doorbell write).
243 	 */
244 	rte_io_wmb();
245 
246 	*(volatile __m128i *)txq->doorbell = oword.eo_u128[0];
247 }
248 
249 static unsigned int
250 sfc_ef10_tx_pkt_descs_max(const struct rte_mbuf *m)
251 {
252 	unsigned int extra_descs_per_seg;
253 	unsigned int extra_descs_per_pkt;
254 
255 	/*
256 	 * VLAN offload is not supported yet, so no extra descriptors
257 	 * are required for VLAN option descriptor.
258 	 */
259 
260 /** Maximum length of the mbuf segment data */
261 #define SFC_MBUF_SEG_LEN_MAX		UINT16_MAX
262 	RTE_BUILD_BUG_ON(sizeof(m->data_len) != 2);
263 
264 	/*
265 	 * Each segment is already counted once below.  So, calculate
266 	 * how many extra DMA descriptors may be required per segment in
267 	 * the worst case because of maximum DMA descriptor length limit.
268 	 * If maximum segment length is less or equal to maximum DMA
269 	 * descriptor length, no extra DMA descriptors are required.
270 	 */
271 	extra_descs_per_seg =
272 		(SFC_MBUF_SEG_LEN_MAX - 1) / SFC_EF10_TX_DMA_DESC_LEN_MAX;
273 
274 /** Maximum length of the packet */
275 #define SFC_MBUF_PKT_LEN_MAX		UINT32_MAX
276 	RTE_BUILD_BUG_ON(sizeof(m->pkt_len) != 4);
277 
278 	/*
279 	 * One more limitation on maximum number of extra DMA descriptors
280 	 * comes from slicing entire packet because of DMA descriptor length
281 	 * limit taking into account that there is at least one segment
282 	 * which is already counted below (so division of the maximum
283 	 * packet length minus one with round down).
284 	 * TSO is not supported yet, so packet length is limited by
285 	 * maximum PDU size.
286 	 */
287 	extra_descs_per_pkt =
288 		(RTE_MIN((unsigned int)EFX_MAC_PDU_MAX,
289 			 SFC_MBUF_PKT_LEN_MAX) - 1) /
290 		SFC_EF10_TX_DMA_DESC_LEN_MAX;
291 
292 	return m->nb_segs + RTE_MIN(m->nb_segs * extra_descs_per_seg,
293 				    extra_descs_per_pkt);
294 }
295 
296 static bool
297 sfc_ef10_try_reap(struct sfc_ef10_txq * const txq, unsigned int added,
298 		  unsigned int needed_desc, unsigned int *dma_desc_space,
299 		  bool *reap_done)
300 {
301 	if (*reap_done)
302 		return false;
303 
304 	if (added != txq->added) {
305 		sfc_ef10_tx_qpush(txq, added, txq->added);
306 		txq->added = added;
307 	}
308 
309 	sfc_ef10_tx_reap(txq);
310 	*reap_done = true;
311 
312 	/*
313 	 * Recalculate DMA descriptor space since Tx reap may change
314 	 * the number of completed descriptors
315 	 */
316 	*dma_desc_space = txq->max_fill_level -
317 		(added - txq->completed);
318 
319 	return (needed_desc <= *dma_desc_space);
320 }
321 
322 static uint16_t
323 sfc_ef10_prepare_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
324 		      uint16_t nb_pkts)
325 {
326 	struct sfc_ef10_txq * const txq = sfc_ef10_txq_by_dp_txq(tx_queue);
327 	uint16_t i;
328 
329 	for (i = 0; i < nb_pkts; i++) {
330 		struct rte_mbuf *m = tx_pkts[i];
331 		int ret;
332 
333 #ifdef RTE_LIBRTE_SFC_EFX_DEBUG
334 		/*
335 		 * In non-TSO case, check that a packet segments do not exceed
336 		 * the size limit. Perform the check in debug mode since MTU
337 		 * more than 9k is not supported, but the limit here is 16k-1.
338 		 */
339 		if (!(m->ol_flags & PKT_TX_TCP_SEG)) {
340 			struct rte_mbuf *m_seg;
341 
342 			for (m_seg = m; m_seg != NULL; m_seg = m_seg->next) {
343 				if (m_seg->data_len >
344 				    SFC_EF10_TX_DMA_DESC_LEN_MAX) {
345 					rte_errno = EINVAL;
346 					break;
347 				}
348 			}
349 		}
350 #endif
351 		ret = sfc_dp_tx_prepare_pkt(m,
352 				txq->tso_tcp_header_offset_limit,
353 				txq->max_fill_level,
354 				SFC_EF10_TSO_OPT_DESCS_NUM, 0);
355 		if (unlikely(ret != 0)) {
356 			rte_errno = ret;
357 			break;
358 		}
359 	}
360 
361 	return i;
362 }
363 
364 static int
365 sfc_ef10_xmit_tso_pkt(struct sfc_ef10_txq * const txq, struct rte_mbuf *m_seg,
366 		      unsigned int *added, unsigned int *dma_desc_space,
367 		      bool *reap_done)
368 {
369 	size_t iph_off = ((m_seg->ol_flags & PKT_TX_TUNNEL_MASK) ?
370 			  m_seg->outer_l2_len + m_seg->outer_l3_len : 0) +
371 			 m_seg->l2_len;
372 	size_t tcph_off = iph_off + m_seg->l3_len;
373 	size_t header_len = tcph_off + m_seg->l4_len;
374 	/* Offset of the payload in the last segment that contains the header */
375 	size_t in_off = 0;
376 	const struct rte_tcp_hdr *th;
377 	uint16_t packet_id = 0;
378 	uint16_t outer_packet_id = 0;
379 	uint32_t sent_seq;
380 	uint8_t *hdr_addr;
381 	rte_iova_t hdr_iova;
382 	struct rte_mbuf *first_m_seg = m_seg;
383 	unsigned int pkt_start = *added;
384 	unsigned int needed_desc;
385 	struct rte_mbuf *m_seg_to_free_up_to = first_m_seg;
386 	bool eop;
387 
388 	/*
389 	 * Preliminary estimation of required DMA descriptors, including extra
390 	 * descriptor for TSO header that is needed when the header is
391 	 * separated from payload in one segment. It does not include
392 	 * extra descriptors that may appear when a big segment is split across
393 	 * several descriptors.
394 	 */
395 	needed_desc = m_seg->nb_segs +
396 			(unsigned int)SFC_EF10_TSO_OPT_DESCS_NUM +
397 			(unsigned int)SFC_EF10_TSO_HDR_DESCS_NUM;
398 
399 	if (needed_desc > *dma_desc_space &&
400 	    !sfc_ef10_try_reap(txq, pkt_start, needed_desc,
401 			       dma_desc_space, reap_done)) {
402 		/*
403 		 * If a future Tx reap may increase available DMA descriptor
404 		 * space, do not try to send the packet.
405 		 */
406 		if (txq->completed != pkt_start)
407 			return ENOSPC;
408 		/*
409 		 * Do not allow to send packet if the maximum DMA
410 		 * descriptor space is not sufficient to hold TSO
411 		 * descriptors, header descriptor and at least 1
412 		 * segment descriptor.
413 		 */
414 		if (*dma_desc_space < SFC_EF10_TSO_OPT_DESCS_NUM +
415 				SFC_EF10_TSO_HDR_DESCS_NUM + 1)
416 			return EMSGSIZE;
417 	}
418 
419 	/* Check if the header is not fragmented */
420 	if (rte_pktmbuf_data_len(m_seg) >= header_len) {
421 		hdr_addr = rte_pktmbuf_mtod(m_seg, uint8_t *);
422 		hdr_iova = rte_mbuf_data_iova(m_seg);
423 		if (rte_pktmbuf_data_len(m_seg) == header_len) {
424 			/* Cannot send a packet that consists only of header */
425 			if (unlikely(m_seg->next == NULL))
426 				return EMSGSIZE;
427 			/*
428 			 * Associate header mbuf with header descriptor
429 			 * which is located after TSO descriptors.
430 			 */
431 			txq->sw_ring[(pkt_start + SFC_EF10_TSO_OPT_DESCS_NUM) &
432 				     txq->ptr_mask].mbuf = m_seg;
433 			m_seg = m_seg->next;
434 			in_off = 0;
435 
436 			/*
437 			 * If there is no payload offset (payload starts at the
438 			 * beginning of a segment) then an extra descriptor for
439 			 * separated header is not needed.
440 			 */
441 			needed_desc--;
442 		} else {
443 			in_off = header_len;
444 		}
445 	} else {
446 		unsigned int copied_segs;
447 		unsigned int hdr_addr_off = (*added & txq->ptr_mask) *
448 				SFC_TSOH_STD_LEN;
449 
450 		/*
451 		 * Discard a packet if header linearization is needed but
452 		 * the header is too big.
453 		 * Duplicate Tx prepare check here to avoid spoil of
454 		 * memory if Tx prepare is skipped.
455 		 */
456 		if (unlikely(header_len > SFC_TSOH_STD_LEN))
457 			return EMSGSIZE;
458 
459 		hdr_addr = txq->tsoh + hdr_addr_off;
460 		hdr_iova = txq->tsoh_iova + hdr_addr_off;
461 		copied_segs = sfc_tso_prepare_header(hdr_addr, header_len,
462 						     &m_seg, &in_off);
463 
464 		/* Cannot send a packet that consists only of header */
465 		if (unlikely(m_seg == NULL))
466 			return EMSGSIZE;
467 
468 		m_seg_to_free_up_to = m_seg;
469 		/*
470 		 * Reduce the number of needed descriptors by the number of
471 		 * segments that entirely consist of header data.
472 		 */
473 		needed_desc -= copied_segs;
474 
475 		/* Extra descriptor for separated header is not needed */
476 		if (in_off == 0)
477 			needed_desc--;
478 	}
479 
480 	/*
481 	 * Tx prepare has debug-only checks that offload flags are correctly
482 	 * filled in in TSO mbuf. Use zero IPID if there is no IPv4 flag.
483 	 * If the packet is still IPv4, HW will simply start from zero IPID.
484 	 */
485 	if (first_m_seg->ol_flags & PKT_TX_IPV4)
486 		packet_id = sfc_tso_ip4_get_ipid(hdr_addr, iph_off);
487 
488 	if (first_m_seg->ol_flags & PKT_TX_OUTER_IPV4)
489 		outer_packet_id = sfc_tso_ip4_get_ipid(hdr_addr,
490 						first_m_seg->outer_l2_len);
491 
492 	th = (const struct rte_tcp_hdr *)(hdr_addr + tcph_off);
493 	rte_memcpy(&sent_seq, &th->sent_seq, sizeof(uint32_t));
494 	sent_seq = rte_be_to_cpu_32(sent_seq);
495 
496 	sfc_ef10_tx_qdesc_tso2_create(txq, *added, packet_id, outer_packet_id,
497 			sent_seq, first_m_seg->tso_segsz);
498 	(*added) += SFC_EF10_TSO_OPT_DESCS_NUM;
499 
500 	sfc_ef10_tx_qdesc_dma_create(hdr_iova, header_len, false,
501 			&txq->txq_hw_ring[(*added) & txq->ptr_mask]);
502 	(*added)++;
503 
504 	do {
505 		rte_iova_t next_frag = rte_mbuf_data_iova(m_seg);
506 		unsigned int seg_len = rte_pktmbuf_data_len(m_seg);
507 		unsigned int id;
508 
509 		next_frag += in_off;
510 		seg_len -= in_off;
511 		in_off = 0;
512 
513 		do {
514 			rte_iova_t frag_addr = next_frag;
515 			size_t frag_len;
516 
517 			frag_len = RTE_MIN(seg_len,
518 					   SFC_EF10_TX_DMA_DESC_LEN_MAX);
519 
520 			next_frag += frag_len;
521 			seg_len -= frag_len;
522 
523 			eop = (seg_len == 0 && m_seg->next == NULL);
524 
525 			id = (*added) & txq->ptr_mask;
526 			(*added)++;
527 
528 			/*
529 			 * Initially we assume that one DMA descriptor is needed
530 			 * for every segment. When the segment is split across
531 			 * several DMA descriptors, increase the estimation.
532 			 */
533 			needed_desc += (seg_len != 0);
534 
535 			/*
536 			 * When no more descriptors can be added, but not all
537 			 * segments are processed.
538 			 */
539 			if (*added - pkt_start == *dma_desc_space &&
540 			    !eop &&
541 			    !sfc_ef10_try_reap(txq, pkt_start, needed_desc,
542 						dma_desc_space, reap_done)) {
543 				struct rte_mbuf *m;
544 				struct rte_mbuf *m_next;
545 
546 				if (txq->completed != pkt_start) {
547 					unsigned int i;
548 
549 					/*
550 					 * Reset mbuf associations with added
551 					 * descriptors.
552 					 */
553 					for (i = pkt_start; i != *added; i++) {
554 						id = i & txq->ptr_mask;
555 						txq->sw_ring[id].mbuf = NULL;
556 					}
557 					return ENOSPC;
558 				}
559 
560 				/* Free the segments that cannot be sent */
561 				for (m = m_seg->next; m != NULL; m = m_next) {
562 					m_next = m->next;
563 					rte_pktmbuf_free_seg(m);
564 				}
565 				eop = true;
566 				/* Ignore the rest of the segment */
567 				seg_len = 0;
568 			}
569 
570 			sfc_ef10_tx_qdesc_dma_create(frag_addr, frag_len,
571 					eop, &txq->txq_hw_ring[id]);
572 
573 		} while (seg_len != 0);
574 
575 		txq->sw_ring[id].mbuf = m_seg;
576 
577 		m_seg = m_seg->next;
578 	} while (!eop);
579 
580 	/*
581 	 * Free segments which content was entirely copied to the TSO header
582 	 * memory space of Tx queue
583 	 */
584 	for (m_seg = first_m_seg; m_seg != m_seg_to_free_up_to;) {
585 		struct rte_mbuf *seg_to_free = m_seg;
586 
587 		m_seg = m_seg->next;
588 		rte_pktmbuf_free_seg(seg_to_free);
589 	}
590 
591 	return 0;
592 }
593 
594 static uint16_t
595 sfc_ef10_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
596 {
597 	struct sfc_ef10_txq * const txq = sfc_ef10_txq_by_dp_txq(tx_queue);
598 	unsigned int added;
599 	unsigned int dma_desc_space;
600 	bool reap_done;
601 	struct rte_mbuf **pktp;
602 	struct rte_mbuf **pktp_end;
603 
604 	if (unlikely(txq->flags &
605 		     (SFC_EF10_TXQ_NOT_RUNNING | SFC_EF10_TXQ_EXCEPTION)))
606 		return 0;
607 
608 	added = txq->added;
609 	dma_desc_space = txq->max_fill_level - (added - txq->completed);
610 
611 	reap_done = (dma_desc_space < txq->free_thresh);
612 	if (reap_done) {
613 		sfc_ef10_tx_reap(txq);
614 		dma_desc_space = txq->max_fill_level - (added - txq->completed);
615 	}
616 
617 	for (pktp = &tx_pkts[0], pktp_end = &tx_pkts[nb_pkts];
618 	     pktp != pktp_end;
619 	     ++pktp) {
620 		struct rte_mbuf *m_seg = *pktp;
621 		unsigned int pkt_start = added;
622 		uint32_t pkt_len;
623 
624 		if (likely(pktp + 1 != pktp_end))
625 			rte_mbuf_prefetch_part1(pktp[1]);
626 
627 		if (m_seg->ol_flags & PKT_TX_TCP_SEG) {
628 			int rc;
629 
630 			rc = sfc_ef10_xmit_tso_pkt(txq, m_seg, &added,
631 					&dma_desc_space, &reap_done);
632 			if (rc != 0) {
633 				added = pkt_start;
634 
635 				/* Packet can be sent in following xmit calls */
636 				if (likely(rc == ENOSPC))
637 					break;
638 
639 				/*
640 				 * Packet cannot be sent, tell RTE that
641 				 * it is sent, but actually drop it and
642 				 * continue with another packet
643 				 */
644 				rte_pktmbuf_free(*pktp);
645 				continue;
646 			}
647 
648 			goto dma_desc_space_update;
649 		}
650 
651 		if (sfc_ef10_tx_pkt_descs_max(m_seg) > dma_desc_space) {
652 			if (reap_done)
653 				break;
654 
655 			/* Push already prepared descriptors before polling */
656 			if (added != txq->added) {
657 				sfc_ef10_tx_qpush(txq, added, txq->added);
658 				txq->added = added;
659 			}
660 
661 			sfc_ef10_tx_reap(txq);
662 			reap_done = true;
663 			dma_desc_space = txq->max_fill_level -
664 				(added - txq->completed);
665 			if (sfc_ef10_tx_pkt_descs_max(m_seg) > dma_desc_space)
666 				break;
667 		}
668 
669 		pkt_len = m_seg->pkt_len;
670 		do {
671 			rte_iova_t seg_addr = rte_mbuf_data_iova(m_seg);
672 			unsigned int seg_len = rte_pktmbuf_data_len(m_seg);
673 			unsigned int id = added & txq->ptr_mask;
674 
675 			SFC_ASSERT(seg_len <= SFC_EF10_TX_DMA_DESC_LEN_MAX);
676 
677 			pkt_len -= seg_len;
678 
679 			sfc_ef10_tx_qdesc_dma_create(seg_addr,
680 				seg_len, (pkt_len == 0),
681 				&txq->txq_hw_ring[id]);
682 
683 			/*
684 			 * rte_pktmbuf_free() is commonly used in DPDK for
685 			 * recycling packets - the function checks every
686 			 * segment's reference counter and returns the
687 			 * buffer to its pool whenever possible;
688 			 * nevertheless, freeing mbuf segments one by one
689 			 * may entail some performance decline;
690 			 * from this point, sfc_efx_tx_reap() does the same job
691 			 * on its own and frees buffers in bulks (all mbufs
692 			 * within a bulk belong to the same pool);
693 			 * from this perspective, individual segment pointers
694 			 * must be associated with the corresponding SW
695 			 * descriptors independently so that only one loop
696 			 * is sufficient on reap to inspect all the buffers
697 			 */
698 			txq->sw_ring[id].mbuf = m_seg;
699 
700 			++added;
701 
702 		} while ((m_seg = m_seg->next) != 0);
703 
704 dma_desc_space_update:
705 		dma_desc_space -= (added - pkt_start);
706 	}
707 
708 	if (likely(added != txq->added)) {
709 		sfc_ef10_tx_qpush(txq, added, txq->added);
710 		txq->added = added;
711 	}
712 
713 #if SFC_TX_XMIT_PKTS_REAP_AT_LEAST_ONCE
714 	if (!reap_done)
715 		sfc_ef10_tx_reap(txq);
716 #endif
717 
718 	return pktp - &tx_pkts[0];
719 }
720 
721 static void
722 sfc_ef10_simple_tx_reap(struct sfc_ef10_txq *txq)
723 {
724 	const unsigned int old_read_ptr = txq->evq_read_ptr;
725 	const unsigned int ptr_mask = txq->ptr_mask;
726 	unsigned int completed = txq->completed;
727 	unsigned int pending = completed;
728 
729 	pending += sfc_ef10_tx_process_events(txq);
730 
731 	if (pending != completed) {
732 		struct rte_mbuf *bulk[SFC_TX_REAP_BULK_SIZE];
733 		unsigned int nb = 0;
734 
735 		do {
736 			struct sfc_ef10_tx_sw_desc *txd;
737 
738 			txd = &txq->sw_ring[completed & ptr_mask];
739 
740 			if (nb == RTE_DIM(bulk)) {
741 				rte_mempool_put_bulk(bulk[0]->pool,
742 						     (void *)bulk, nb);
743 				nb = 0;
744 			}
745 
746 			bulk[nb++] = txd->mbuf;
747 		} while (++completed != pending);
748 
749 		rte_mempool_put_bulk(bulk[0]->pool, (void *)bulk, nb);
750 
751 		txq->completed = completed;
752 	}
753 
754 	sfc_ef10_ev_qclear(txq->evq_hw_ring, ptr_mask, old_read_ptr,
755 			   txq->evq_read_ptr);
756 }
757 
758 #ifdef RTE_LIBRTE_SFC_EFX_DEBUG
759 static uint16_t
760 sfc_ef10_simple_prepare_pkts(__rte_unused void *tx_queue,
761 			     struct rte_mbuf **tx_pkts,
762 			     uint16_t nb_pkts)
763 {
764 	uint16_t i;
765 
766 	for (i = 0; i < nb_pkts; i++) {
767 		struct rte_mbuf *m = tx_pkts[i];
768 		int ret;
769 
770 		ret = rte_validate_tx_offload(m);
771 		if (unlikely(ret != 0)) {
772 			/*
773 			 * Negative error code is returned by
774 			 * rte_validate_tx_offload(), but positive are used
775 			 * inside net/sfc PMD.
776 			 */
777 			SFC_ASSERT(ret < 0);
778 			rte_errno = -ret;
779 			break;
780 		}
781 
782 		/* ef10_simple does not support TSO and VLAN insertion */
783 		if (unlikely(m->ol_flags &
784 			     (PKT_TX_TCP_SEG | PKT_TX_VLAN_PKT))) {
785 			rte_errno = ENOTSUP;
786 			break;
787 		}
788 
789 		/* ef10_simple does not support scattered packets */
790 		if (unlikely(m->nb_segs != 1)) {
791 			rte_errno = ENOTSUP;
792 			break;
793 		}
794 
795 		/*
796 		 * ef10_simple requires fast-free which ignores reference
797 		 * counters
798 		 */
799 		if (unlikely(rte_mbuf_refcnt_read(m) != 1)) {
800 			rte_errno = ENOTSUP;
801 			break;
802 		}
803 
804 		/* ef10_simple requires single pool for all packets */
805 		if (unlikely(m->pool != tx_pkts[0]->pool)) {
806 			rte_errno = ENOTSUP;
807 			break;
808 		}
809 	}
810 
811 	return i;
812 }
813 #endif
814 
815 static uint16_t
816 sfc_ef10_simple_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
817 			  uint16_t nb_pkts)
818 {
819 	struct sfc_ef10_txq * const txq = sfc_ef10_txq_by_dp_txq(tx_queue);
820 	unsigned int ptr_mask;
821 	unsigned int added;
822 	unsigned int dma_desc_space;
823 	bool reap_done;
824 	struct rte_mbuf **pktp;
825 	struct rte_mbuf **pktp_end;
826 
827 	if (unlikely(txq->flags &
828 		     (SFC_EF10_TXQ_NOT_RUNNING | SFC_EF10_TXQ_EXCEPTION)))
829 		return 0;
830 
831 	ptr_mask = txq->ptr_mask;
832 	added = txq->added;
833 	dma_desc_space = txq->max_fill_level - (added - txq->completed);
834 
835 	reap_done = (dma_desc_space < RTE_MAX(txq->free_thresh, nb_pkts));
836 	if (reap_done) {
837 		sfc_ef10_simple_tx_reap(txq);
838 		dma_desc_space = txq->max_fill_level - (added - txq->completed);
839 	}
840 
841 	pktp_end = &tx_pkts[MIN(nb_pkts, dma_desc_space)];
842 	for (pktp = &tx_pkts[0]; pktp != pktp_end; ++pktp) {
843 		struct rte_mbuf *pkt = *pktp;
844 		unsigned int id = added & ptr_mask;
845 
846 		SFC_ASSERT(rte_pktmbuf_data_len(pkt) <=
847 			   SFC_EF10_TX_DMA_DESC_LEN_MAX);
848 
849 		sfc_ef10_tx_qdesc_dma_create(rte_mbuf_data_iova(pkt),
850 					     rte_pktmbuf_data_len(pkt),
851 					     true, &txq->txq_hw_ring[id]);
852 
853 		txq->sw_ring[id].mbuf = pkt;
854 
855 		++added;
856 	}
857 
858 	if (likely(added != txq->added)) {
859 		sfc_ef10_tx_qpush(txq, added, txq->added);
860 		txq->added = added;
861 	}
862 
863 #if SFC_TX_XMIT_PKTS_REAP_AT_LEAST_ONCE
864 	if (!reap_done)
865 		sfc_ef10_simple_tx_reap(txq);
866 #endif
867 
868 	return pktp - &tx_pkts[0];
869 }
870 
871 static sfc_dp_tx_get_dev_info_t sfc_ef10_get_dev_info;
872 static void
873 sfc_ef10_get_dev_info(struct rte_eth_dev_info *dev_info)
874 {
875 	/*
876 	 * Number of descriptors just defines maximum number of pushed
877 	 * descriptors (fill level).
878 	 */
879 	dev_info->tx_desc_lim.nb_min = 1;
880 	dev_info->tx_desc_lim.nb_align = 1;
881 }
882 
883 static sfc_dp_tx_qsize_up_rings_t sfc_ef10_tx_qsize_up_rings;
884 static int
885 sfc_ef10_tx_qsize_up_rings(uint16_t nb_tx_desc,
886 			   struct sfc_dp_tx_hw_limits *limits,
887 			   unsigned int *txq_entries,
888 			   unsigned int *evq_entries,
889 			   unsigned int *txq_max_fill_level)
890 {
891 	/*
892 	 * rte_ethdev API guarantees that the number meets min, max and
893 	 * alignment requirements.
894 	 */
895 	if (nb_tx_desc <= limits->txq_min_entries)
896 		*txq_entries = limits->txq_min_entries;
897 	else
898 		*txq_entries = rte_align32pow2(nb_tx_desc);
899 
900 	*evq_entries = *txq_entries;
901 
902 	*txq_max_fill_level = RTE_MIN(nb_tx_desc,
903 				      SFC_EF10_TXQ_LIMIT(*evq_entries));
904 	return 0;
905 }
906 
907 static sfc_dp_tx_qcreate_t sfc_ef10_tx_qcreate;
908 static int
909 sfc_ef10_tx_qcreate(uint16_t port_id, uint16_t queue_id,
910 		    const struct rte_pci_addr *pci_addr, int socket_id,
911 		    const struct sfc_dp_tx_qcreate_info *info,
912 		    struct sfc_dp_txq **dp_txqp)
913 {
914 	struct sfc_ef10_txq *txq;
915 	int rc;
916 
917 	rc = EINVAL;
918 	if (info->txq_entries != info->evq_entries)
919 		goto fail_bad_args;
920 
921 	rc = ENOMEM;
922 	txq = rte_zmalloc_socket("sfc-ef10-txq", sizeof(*txq),
923 				 RTE_CACHE_LINE_SIZE, socket_id);
924 	if (txq == NULL)
925 		goto fail_txq_alloc;
926 
927 	sfc_dp_queue_init(&txq->dp.dpq, port_id, queue_id, pci_addr);
928 
929 	rc = ENOMEM;
930 	txq->sw_ring = rte_calloc_socket("sfc-ef10-txq-sw_ring",
931 					 info->txq_entries,
932 					 sizeof(*txq->sw_ring),
933 					 RTE_CACHE_LINE_SIZE, socket_id);
934 	if (txq->sw_ring == NULL)
935 		goto fail_sw_ring_alloc;
936 
937 	if (info->offloads & (DEV_TX_OFFLOAD_TCP_TSO |
938 			      DEV_TX_OFFLOAD_VXLAN_TNL_TSO |
939 			      DEV_TX_OFFLOAD_GENEVE_TNL_TSO)) {
940 		txq->tsoh = rte_calloc_socket("sfc-ef10-txq-tsoh",
941 					      info->txq_entries,
942 					      SFC_TSOH_STD_LEN,
943 					      RTE_CACHE_LINE_SIZE,
944 					      socket_id);
945 		if (txq->tsoh == NULL)
946 			goto fail_tsoh_alloc;
947 
948 		txq->tsoh_iova = rte_malloc_virt2iova(txq->tsoh);
949 	}
950 
951 	txq->flags = SFC_EF10_TXQ_NOT_RUNNING;
952 	txq->ptr_mask = info->txq_entries - 1;
953 	txq->max_fill_level = info->max_fill_level;
954 	txq->free_thresh = info->free_thresh;
955 	txq->txq_hw_ring = info->txq_hw_ring;
956 	txq->doorbell = (volatile uint8_t *)info->mem_bar +
957 			ER_DZ_TX_DESC_UPD_REG_OFST +
958 			(info->hw_index << info->vi_window_shift);
959 	txq->evq_hw_ring = info->evq_hw_ring;
960 	txq->tso_tcp_header_offset_limit = info->tso_tcp_header_offset_limit;
961 
962 	*dp_txqp = &txq->dp;
963 	return 0;
964 
965 fail_tsoh_alloc:
966 	rte_free(txq->sw_ring);
967 
968 fail_sw_ring_alloc:
969 	rte_free(txq);
970 
971 fail_txq_alloc:
972 fail_bad_args:
973 	return rc;
974 }
975 
976 static sfc_dp_tx_qdestroy_t sfc_ef10_tx_qdestroy;
977 static void
978 sfc_ef10_tx_qdestroy(struct sfc_dp_txq *dp_txq)
979 {
980 	struct sfc_ef10_txq *txq = sfc_ef10_txq_by_dp_txq(dp_txq);
981 
982 	rte_free(txq->tsoh);
983 	rte_free(txq->sw_ring);
984 	rte_free(txq);
985 }
986 
987 static sfc_dp_tx_qstart_t sfc_ef10_tx_qstart;
988 static int
989 sfc_ef10_tx_qstart(struct sfc_dp_txq *dp_txq, unsigned int evq_read_ptr,
990 		   unsigned int txq_desc_index)
991 {
992 	struct sfc_ef10_txq *txq = sfc_ef10_txq_by_dp_txq(dp_txq);
993 
994 	txq->evq_read_ptr = evq_read_ptr;
995 	txq->added = txq->completed = txq_desc_index;
996 
997 	txq->flags |= SFC_EF10_TXQ_STARTED;
998 	txq->flags &= ~(SFC_EF10_TXQ_NOT_RUNNING | SFC_EF10_TXQ_EXCEPTION);
999 
1000 	return 0;
1001 }
1002 
1003 static sfc_dp_tx_qstop_t sfc_ef10_tx_qstop;
1004 static void
1005 sfc_ef10_tx_qstop(struct sfc_dp_txq *dp_txq, unsigned int *evq_read_ptr)
1006 {
1007 	struct sfc_ef10_txq *txq = sfc_ef10_txq_by_dp_txq(dp_txq);
1008 
1009 	txq->flags |= SFC_EF10_TXQ_NOT_RUNNING;
1010 
1011 	*evq_read_ptr = txq->evq_read_ptr;
1012 }
1013 
1014 static sfc_dp_tx_qtx_ev_t sfc_ef10_tx_qtx_ev;
1015 static bool
1016 sfc_ef10_tx_qtx_ev(struct sfc_dp_txq *dp_txq, __rte_unused unsigned int id)
1017 {
1018 	__rte_unused struct sfc_ef10_txq *txq = sfc_ef10_txq_by_dp_txq(dp_txq);
1019 
1020 	SFC_ASSERT(txq->flags & SFC_EF10_TXQ_NOT_RUNNING);
1021 
1022 	/*
1023 	 * It is safe to ignore Tx event since we reap all mbufs on
1024 	 * queue purge anyway.
1025 	 */
1026 
1027 	return false;
1028 }
1029 
1030 static sfc_dp_tx_qreap_t sfc_ef10_tx_qreap;
1031 static void
1032 sfc_ef10_tx_qreap(struct sfc_dp_txq *dp_txq)
1033 {
1034 	struct sfc_ef10_txq *txq = sfc_ef10_txq_by_dp_txq(dp_txq);
1035 	unsigned int completed;
1036 
1037 	for (completed = txq->completed; completed != txq->added; ++completed) {
1038 		struct sfc_ef10_tx_sw_desc *txd;
1039 
1040 		txd = &txq->sw_ring[completed & txq->ptr_mask];
1041 		if (txd->mbuf != NULL) {
1042 			rte_pktmbuf_free_seg(txd->mbuf);
1043 			txd->mbuf = NULL;
1044 		}
1045 	}
1046 
1047 	txq->flags &= ~SFC_EF10_TXQ_STARTED;
1048 }
1049 
1050 static unsigned int
1051 sfc_ef10_tx_qdesc_npending(struct sfc_ef10_txq *txq)
1052 {
1053 	const unsigned int curr_done = txq->completed - 1;
1054 	unsigned int anew_done = curr_done;
1055 	efx_qword_t tx_ev;
1056 	const unsigned int evq_old_read_ptr = txq->evq_read_ptr;
1057 
1058 	if (unlikely(txq->flags &
1059 		     (SFC_EF10_TXQ_NOT_RUNNING | SFC_EF10_TXQ_EXCEPTION)))
1060 		return 0;
1061 
1062 	while (sfc_ef10_tx_get_event(txq, &tx_ev))
1063 		anew_done = EFX_QWORD_FIELD(tx_ev, ESF_DZ_TX_DESCR_INDX);
1064 
1065 	/*
1066 	 * The function does not process events, so return event queue read
1067 	 * pointer to the original position to allow the events that were
1068 	 * read to be processed later
1069 	 */
1070 	txq->evq_read_ptr = evq_old_read_ptr;
1071 
1072 	return (anew_done - curr_done) & txq->ptr_mask;
1073 }
1074 
1075 static sfc_dp_tx_qdesc_status_t sfc_ef10_tx_qdesc_status;
1076 static int
1077 sfc_ef10_tx_qdesc_status(struct sfc_dp_txq *dp_txq,
1078 			 uint16_t offset)
1079 {
1080 	struct sfc_ef10_txq *txq = sfc_ef10_txq_by_dp_txq(dp_txq);
1081 	unsigned int npending = sfc_ef10_tx_qdesc_npending(txq);
1082 
1083 	if (unlikely(offset > txq->ptr_mask))
1084 		return -EINVAL;
1085 
1086 	if (unlikely(offset >= txq->max_fill_level))
1087 		return RTE_ETH_TX_DESC_UNAVAIL;
1088 
1089 	if (unlikely(offset < npending))
1090 		return RTE_ETH_TX_DESC_FULL;
1091 
1092 	return RTE_ETH_TX_DESC_DONE;
1093 }
1094 
1095 struct sfc_dp_tx sfc_ef10_tx = {
1096 	.dp = {
1097 		.name		= SFC_KVARG_DATAPATH_EF10,
1098 		.type		= SFC_DP_TX,
1099 		.hw_fw_caps	= SFC_DP_HW_FW_CAP_EF10,
1100 	},
1101 	.features		= SFC_DP_TX_FEAT_MULTI_PROCESS,
1102 	.dev_offload_capa	= DEV_TX_OFFLOAD_MULTI_SEGS,
1103 	.queue_offload_capa	= DEV_TX_OFFLOAD_IPV4_CKSUM |
1104 				  DEV_TX_OFFLOAD_UDP_CKSUM |
1105 				  DEV_TX_OFFLOAD_TCP_CKSUM |
1106 				  DEV_TX_OFFLOAD_OUTER_IPV4_CKSUM |
1107 				  DEV_TX_OFFLOAD_TCP_TSO |
1108 				  DEV_TX_OFFLOAD_VXLAN_TNL_TSO |
1109 				  DEV_TX_OFFLOAD_GENEVE_TNL_TSO,
1110 	.get_dev_info		= sfc_ef10_get_dev_info,
1111 	.qsize_up_rings		= sfc_ef10_tx_qsize_up_rings,
1112 	.qcreate		= sfc_ef10_tx_qcreate,
1113 	.qdestroy		= sfc_ef10_tx_qdestroy,
1114 	.qstart			= sfc_ef10_tx_qstart,
1115 	.qtx_ev			= sfc_ef10_tx_qtx_ev,
1116 	.qstop			= sfc_ef10_tx_qstop,
1117 	.qreap			= sfc_ef10_tx_qreap,
1118 	.qdesc_status		= sfc_ef10_tx_qdesc_status,
1119 	.pkt_prepare		= sfc_ef10_prepare_pkts,
1120 	.pkt_burst		= sfc_ef10_xmit_pkts,
1121 };
1122 
1123 struct sfc_dp_tx sfc_ef10_simple_tx = {
1124 	.dp = {
1125 		.name		= SFC_KVARG_DATAPATH_EF10_SIMPLE,
1126 		.type		= SFC_DP_TX,
1127 	},
1128 	.features		= SFC_DP_TX_FEAT_MULTI_PROCESS,
1129 	.dev_offload_capa	= DEV_TX_OFFLOAD_MBUF_FAST_FREE,
1130 	.queue_offload_capa	= DEV_TX_OFFLOAD_IPV4_CKSUM |
1131 				  DEV_TX_OFFLOAD_UDP_CKSUM |
1132 				  DEV_TX_OFFLOAD_TCP_CKSUM |
1133 				  DEV_TX_OFFLOAD_OUTER_IPV4_CKSUM,
1134 	.get_dev_info		= sfc_ef10_get_dev_info,
1135 	.qsize_up_rings		= sfc_ef10_tx_qsize_up_rings,
1136 	.qcreate		= sfc_ef10_tx_qcreate,
1137 	.qdestroy		= sfc_ef10_tx_qdestroy,
1138 	.qstart			= sfc_ef10_tx_qstart,
1139 	.qtx_ev			= sfc_ef10_tx_qtx_ev,
1140 	.qstop			= sfc_ef10_tx_qstop,
1141 	.qreap			= sfc_ef10_tx_qreap,
1142 	.qdesc_status		= sfc_ef10_tx_qdesc_status,
1143 #ifdef RTE_LIBRTE_SFC_EFX_DEBUG
1144 	.pkt_prepare		= sfc_ef10_simple_prepare_pkts,
1145 #endif
1146 	.pkt_burst		= sfc_ef10_simple_xmit_pkts,
1147 };
1148