1 /*
2  * Copyright (c) 2015-2016, Mellanox Technologies. All rights reserved.
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the
8  * OpenIB.org BSD license below:
9  *
10  *     Redistribution and use in source and binary forms, with or
11  *     without modification, are permitted provided that the following
12  *     conditions are met:
13  *
14  *      - Redistributions of source code must retain the above
15  *        copyright notice, this list of conditions and the following
16  *        disclaimer.
17  *
18  *      - Redistributions in binary form must reproduce the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer in the documentation and/or other materials
21  *        provided with the distribution.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30  * SOFTWARE.
31  */
32 
33 #include <linux/tcp.h>
34 #include <linux/if_vlan.h>
35 #include "en.h"
36 
37 #define MLX5E_SQ_NOPS_ROOM  MLX5_SEND_WQE_MAX_WQEBBS
38 #define MLX5E_SQ_STOP_ROOM (MLX5_SEND_WQE_MAX_WQEBBS +\
39 			    MLX5E_SQ_NOPS_ROOM)
40 
41 void mlx5e_send_nop(struct mlx5e_sq *sq, bool notify_hw)
42 {
43 	struct mlx5_wq_cyc                *wq  = &sq->wq;
44 
45 	u16 pi = sq->pc & wq->sz_m1;
46 	struct mlx5e_tx_wqe              *wqe  = mlx5_wq_cyc_get_wqe(wq, pi);
47 
48 	struct mlx5_wqe_ctrl_seg         *cseg = &wqe->ctrl;
49 
50 	memset(cseg, 0, sizeof(*cseg));
51 
52 	cseg->opmod_idx_opcode = cpu_to_be32((sq->pc << 8) | MLX5_OPCODE_NOP);
53 	cseg->qpn_ds           = cpu_to_be32((sq->sqn << 8) | 0x01);
54 
55 	sq->skb[pi] = NULL;
56 	sq->pc++;
57 	sq->stats.nop++;
58 
59 	if (notify_hw) {
60 		cseg->fm_ce_se = MLX5_WQE_CTRL_CQ_UPDATE;
61 		mlx5e_tx_notify_hw(sq, &wqe->ctrl, 0);
62 	}
63 }
64 
65 static inline void mlx5e_tx_dma_unmap(struct device *pdev,
66 				      struct mlx5e_sq_dma *dma)
67 {
68 	switch (dma->type) {
69 	case MLX5E_DMA_MAP_SINGLE:
70 		dma_unmap_single(pdev, dma->addr, dma->size, DMA_TO_DEVICE);
71 		break;
72 	case MLX5E_DMA_MAP_PAGE:
73 		dma_unmap_page(pdev, dma->addr, dma->size, DMA_TO_DEVICE);
74 		break;
75 	default:
76 		WARN_ONCE(true, "mlx5e_tx_dma_unmap unknown DMA type!\n");
77 	}
78 }
79 
80 static inline void mlx5e_dma_push(struct mlx5e_sq *sq,
81 				  dma_addr_t addr,
82 				  u32 size,
83 				  enum mlx5e_dma_map_type map_type)
84 {
85 	sq->dma_fifo[sq->dma_fifo_pc & sq->dma_fifo_mask].addr = addr;
86 	sq->dma_fifo[sq->dma_fifo_pc & sq->dma_fifo_mask].size = size;
87 	sq->dma_fifo[sq->dma_fifo_pc & sq->dma_fifo_mask].type = map_type;
88 	sq->dma_fifo_pc++;
89 }
90 
91 static inline struct mlx5e_sq_dma *mlx5e_dma_get(struct mlx5e_sq *sq, u32 i)
92 {
93 	return &sq->dma_fifo[i & sq->dma_fifo_mask];
94 }
95 
96 static void mlx5e_dma_unmap_wqe_err(struct mlx5e_sq *sq, u8 num_dma)
97 {
98 	int i;
99 
100 	for (i = 0; i < num_dma; i++) {
101 		struct mlx5e_sq_dma *last_pushed_dma =
102 			mlx5e_dma_get(sq, --sq->dma_fifo_pc);
103 
104 		mlx5e_tx_dma_unmap(sq->pdev, last_pushed_dma);
105 	}
106 }
107 
108 u16 mlx5e_select_queue(struct net_device *dev, struct sk_buff *skb,
109 		       void *accel_priv, select_queue_fallback_t fallback)
110 {
111 	struct mlx5e_priv *priv = netdev_priv(dev);
112 	int channel_ix = fallback(dev, skb);
113 	int up = 0;
114 
115 	if (!netdev_get_num_tc(dev))
116 		return channel_ix;
117 
118 	if (skb_vlan_tag_present(skb))
119 		up = skb->vlan_tci >> VLAN_PRIO_SHIFT;
120 
121 	/* channel_ix can be larger than num_channels since
122 	 * dev->num_real_tx_queues = num_channels * num_tc
123 	 */
124 	if (channel_ix >= priv->params.num_channels)
125 		channel_ix = reciprocal_scale(channel_ix,
126 					      priv->params.num_channels);
127 
128 	return priv->channeltc_to_txq_map[channel_ix][up];
129 }
130 
131 static inline int mlx5e_skb_l2_header_offset(struct sk_buff *skb)
132 {
133 #define MLX5E_MIN_INLINE (ETH_HLEN + VLAN_HLEN)
134 
135 	return max(skb_network_offset(skb), MLX5E_MIN_INLINE);
136 }
137 
138 static inline int mlx5e_skb_l3_header_offset(struct sk_buff *skb)
139 {
140 	struct flow_keys keys;
141 
142 	if (skb_transport_header_was_set(skb))
143 		return skb_transport_offset(skb);
144 	else if (skb_flow_dissect_flow_keys(skb, &keys, 0))
145 		return keys.control.thoff;
146 	else
147 		return mlx5e_skb_l2_header_offset(skb);
148 }
149 
150 static inline unsigned int mlx5e_calc_min_inline(enum mlx5_inline_modes mode,
151 						 struct sk_buff *skb)
152 {
153 	int hlen;
154 
155 	switch (mode) {
156 	case MLX5_INLINE_MODE_TCP_UDP:
157 		hlen = eth_get_headlen(skb->data, skb_headlen(skb));
158 		if (hlen == ETH_HLEN && !skb_vlan_tag_present(skb))
159 			hlen += VLAN_HLEN;
160 		return hlen;
161 	case MLX5_INLINE_MODE_IP:
162 		/* When transport header is set to zero, it means no transport
163 		 * header. When transport header is set to 0xff's, it means
164 		 * transport header wasn't set.
165 		 */
166 		if (skb_transport_offset(skb))
167 			return mlx5e_skb_l3_header_offset(skb);
168 		/* fall through */
169 	case MLX5_INLINE_MODE_L2:
170 	default:
171 		return mlx5e_skb_l2_header_offset(skb);
172 	}
173 }
174 
175 static inline u16 mlx5e_get_inline_hdr_size(struct mlx5e_sq *sq,
176 					    struct sk_buff *skb, bool bf)
177 {
178 	/* Some NIC TX decisions, e.g loopback, are based on the packet
179 	 * headers and occur before the data gather.
180 	 * Therefore these headers must be copied into the WQE
181 	 */
182 	if (bf) {
183 		u16 ihs = skb_headlen(skb);
184 
185 		if (skb_vlan_tag_present(skb))
186 			ihs += VLAN_HLEN;
187 
188 		if (ihs <= sq->max_inline)
189 			return skb_headlen(skb);
190 	}
191 	return mlx5e_calc_min_inline(sq->min_inline_mode, skb);
192 }
193 
194 static inline void mlx5e_tx_skb_pull_inline(unsigned char **skb_data,
195 					    unsigned int *skb_len,
196 					    unsigned int len)
197 {
198 	*skb_len -= len;
199 	*skb_data += len;
200 }
201 
202 static inline void mlx5e_insert_vlan(void *start, struct sk_buff *skb, u16 ihs,
203 				     unsigned char **skb_data,
204 				     unsigned int *skb_len)
205 {
206 	struct vlan_ethhdr *vhdr = (struct vlan_ethhdr *)start;
207 	int cpy1_sz = 2 * ETH_ALEN;
208 	int cpy2_sz = ihs - cpy1_sz;
209 
210 	memcpy(vhdr, *skb_data, cpy1_sz);
211 	mlx5e_tx_skb_pull_inline(skb_data, skb_len, cpy1_sz);
212 	vhdr->h_vlan_proto = skb->vlan_proto;
213 	vhdr->h_vlan_TCI = cpu_to_be16(skb_vlan_tag_get(skb));
214 	memcpy(&vhdr->h_vlan_encapsulated_proto, *skb_data, cpy2_sz);
215 	mlx5e_tx_skb_pull_inline(skb_data, skb_len, cpy2_sz);
216 }
217 
218 static netdev_tx_t mlx5e_sq_xmit(struct mlx5e_sq *sq, struct sk_buff *skb)
219 {
220 	struct mlx5_wq_cyc       *wq   = &sq->wq;
221 
222 	u16 pi = sq->pc & wq->sz_m1;
223 	struct mlx5e_tx_wqe      *wqe  = mlx5_wq_cyc_get_wqe(wq, pi);
224 	struct mlx5e_tx_wqe_info *wi   = &sq->wqe_info[pi];
225 
226 	struct mlx5_wqe_ctrl_seg *cseg = &wqe->ctrl;
227 	struct mlx5_wqe_eth_seg  *eseg = &wqe->eth;
228 	struct mlx5_wqe_data_seg *dseg;
229 
230 	unsigned char *skb_data = skb->data;
231 	unsigned int skb_len = skb->len;
232 	u8  opcode = MLX5_OPCODE_SEND;
233 	dma_addr_t dma_addr = 0;
234 	unsigned int num_bytes;
235 	bool bf = false;
236 	u16 headlen;
237 	u16 ds_cnt;
238 	u16 ihs;
239 	int i;
240 
241 	memset(wqe, 0, sizeof(*wqe));
242 
243 	if (likely(skb->ip_summed == CHECKSUM_PARTIAL)) {
244 		eseg->cs_flags = MLX5_ETH_WQE_L3_CSUM;
245 		if (skb->encapsulation) {
246 			eseg->cs_flags |= MLX5_ETH_WQE_L3_INNER_CSUM |
247 					  MLX5_ETH_WQE_L4_INNER_CSUM;
248 			sq->stats.csum_partial_inner++;
249 		} else {
250 			eseg->cs_flags |= MLX5_ETH_WQE_L4_CSUM;
251 		}
252 	} else
253 		sq->stats.csum_none++;
254 
255 	if (sq->cc != sq->prev_cc) {
256 		sq->prev_cc = sq->cc;
257 		sq->bf_budget = (sq->cc == sq->pc) ? MLX5E_SQ_BF_BUDGET : 0;
258 	}
259 
260 	if (skb_is_gso(skb)) {
261 		eseg->mss    = cpu_to_be16(skb_shinfo(skb)->gso_size);
262 		opcode       = MLX5_OPCODE_LSO;
263 
264 		if (skb->encapsulation) {
265 			ihs = skb_inner_transport_offset(skb) + inner_tcp_hdrlen(skb);
266 			sq->stats.tso_inner_packets++;
267 			sq->stats.tso_inner_bytes += skb->len - ihs;
268 		} else {
269 			ihs = skb_transport_offset(skb) + tcp_hdrlen(skb);
270 			sq->stats.tso_packets++;
271 			sq->stats.tso_bytes += skb->len - ihs;
272 		}
273 
274 		num_bytes = skb->len + (skb_shinfo(skb)->gso_segs - 1) * ihs;
275 	} else {
276 		bf = sq->bf_budget &&
277 		     !skb->xmit_more &&
278 		     !skb_shinfo(skb)->nr_frags;
279 		ihs = mlx5e_get_inline_hdr_size(sq, skb, bf);
280 		num_bytes = max_t(unsigned int, skb->len, ETH_ZLEN);
281 	}
282 
283 	wi->num_bytes = num_bytes;
284 
285 	if (skb_vlan_tag_present(skb)) {
286 		mlx5e_insert_vlan(eseg->inline_hdr_start, skb, ihs, &skb_data,
287 				  &skb_len);
288 		ihs += VLAN_HLEN;
289 	} else {
290 		memcpy(eseg->inline_hdr_start, skb_data, ihs);
291 		mlx5e_tx_skb_pull_inline(&skb_data, &skb_len, ihs);
292 	}
293 
294 	eseg->inline_hdr_sz = cpu_to_be16(ihs);
295 
296 	ds_cnt  = sizeof(*wqe) / MLX5_SEND_WQE_DS;
297 	ds_cnt += DIV_ROUND_UP(ihs - sizeof(eseg->inline_hdr_start),
298 			       MLX5_SEND_WQE_DS);
299 	dseg    = (struct mlx5_wqe_data_seg *)cseg + ds_cnt;
300 
301 	wi->num_dma = 0;
302 
303 	headlen = skb_len - skb->data_len;
304 	if (headlen) {
305 		dma_addr = dma_map_single(sq->pdev, skb_data, headlen,
306 					  DMA_TO_DEVICE);
307 		if (unlikely(dma_mapping_error(sq->pdev, dma_addr)))
308 			goto dma_unmap_wqe_err;
309 
310 		dseg->addr       = cpu_to_be64(dma_addr);
311 		dseg->lkey       = sq->mkey_be;
312 		dseg->byte_count = cpu_to_be32(headlen);
313 
314 		mlx5e_dma_push(sq, dma_addr, headlen, MLX5E_DMA_MAP_SINGLE);
315 		wi->num_dma++;
316 
317 		dseg++;
318 	}
319 
320 	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
321 		struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i];
322 		int fsz = skb_frag_size(frag);
323 
324 		dma_addr = skb_frag_dma_map(sq->pdev, frag, 0, fsz,
325 					    DMA_TO_DEVICE);
326 		if (unlikely(dma_mapping_error(sq->pdev, dma_addr)))
327 			goto dma_unmap_wqe_err;
328 
329 		dseg->addr       = cpu_to_be64(dma_addr);
330 		dseg->lkey       = sq->mkey_be;
331 		dseg->byte_count = cpu_to_be32(fsz);
332 
333 		mlx5e_dma_push(sq, dma_addr, fsz, MLX5E_DMA_MAP_PAGE);
334 		wi->num_dma++;
335 
336 		dseg++;
337 	}
338 
339 	ds_cnt += wi->num_dma;
340 
341 	cseg->opmod_idx_opcode = cpu_to_be32((sq->pc << 8) | opcode);
342 	cseg->qpn_ds           = cpu_to_be32((sq->sqn << 8) | ds_cnt);
343 
344 	sq->skb[pi] = skb;
345 
346 	wi->num_wqebbs = DIV_ROUND_UP(ds_cnt, MLX5_SEND_WQEBB_NUM_DS);
347 	sq->pc += wi->num_wqebbs;
348 
349 	netdev_tx_sent_queue(sq->txq, wi->num_bytes);
350 
351 	if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP))
352 		skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
353 
354 	if (unlikely(!mlx5e_sq_has_room_for(sq, MLX5E_SQ_STOP_ROOM))) {
355 		netif_tx_stop_queue(sq->txq);
356 		sq->stats.stopped++;
357 	}
358 
359 	if (!skb->xmit_more || netif_xmit_stopped(sq->txq)) {
360 		int bf_sz = 0;
361 
362 		if (bf && test_bit(MLX5E_SQ_STATE_BF_ENABLE, &sq->state))
363 			bf_sz = wi->num_wqebbs << 3;
364 
365 		cseg->fm_ce_se = MLX5_WQE_CTRL_CQ_UPDATE;
366 		mlx5e_tx_notify_hw(sq, &wqe->ctrl, bf_sz);
367 	}
368 
369 	/* fill sq edge with nops to avoid wqe wrap around */
370 	while ((sq->pc & wq->sz_m1) > sq->edge)
371 		mlx5e_send_nop(sq, false);
372 
373 	if (bf)
374 		sq->bf_budget--;
375 
376 	sq->stats.packets++;
377 	sq->stats.bytes += num_bytes;
378 	return NETDEV_TX_OK;
379 
380 dma_unmap_wqe_err:
381 	sq->stats.dropped++;
382 	mlx5e_dma_unmap_wqe_err(sq, wi->num_dma);
383 
384 	dev_kfree_skb_any(skb);
385 
386 	return NETDEV_TX_OK;
387 }
388 
389 netdev_tx_t mlx5e_xmit(struct sk_buff *skb, struct net_device *dev)
390 {
391 	struct mlx5e_priv *priv = netdev_priv(dev);
392 	struct mlx5e_sq *sq = priv->txq_to_sq_map[skb_get_queue_mapping(skb)];
393 
394 	return mlx5e_sq_xmit(sq, skb);
395 }
396 
397 void mlx5e_free_tx_descs(struct mlx5e_sq *sq)
398 {
399 	struct mlx5e_tx_wqe_info *wi;
400 	struct sk_buff *skb;
401 	u16 ci;
402 	int i;
403 
404 	while (sq->cc != sq->pc) {
405 		ci = sq->cc & sq->wq.sz_m1;
406 		skb = sq->skb[ci];
407 		wi = &sq->wqe_info[ci];
408 
409 		if (!skb) { /* nop */
410 			sq->cc++;
411 			continue;
412 		}
413 
414 		for (i = 0; i < wi->num_dma; i++) {
415 			struct mlx5e_sq_dma *dma =
416 				mlx5e_dma_get(sq, sq->dma_fifo_cc++);
417 
418 			mlx5e_tx_dma_unmap(sq->pdev, dma);
419 		}
420 
421 		dev_kfree_skb_any(skb);
422 		sq->cc += wi->num_wqebbs;
423 	}
424 }
425 
426 bool mlx5e_poll_tx_cq(struct mlx5e_cq *cq, int napi_budget)
427 {
428 	struct mlx5e_sq *sq;
429 	u32 dma_fifo_cc;
430 	u32 nbytes;
431 	u16 npkts;
432 	u16 sqcc;
433 	int i;
434 
435 	sq = container_of(cq, struct mlx5e_sq, cq);
436 
437 	if (unlikely(test_bit(MLX5E_SQ_STATE_TX_TIMEOUT, &sq->state)))
438 		return false;
439 
440 	npkts = 0;
441 	nbytes = 0;
442 
443 	/* sq->cc must be updated only after mlx5_cqwq_update_db_record(),
444 	 * otherwise a cq overrun may occur
445 	 */
446 	sqcc = sq->cc;
447 
448 	/* avoid dirtying sq cache line every cqe */
449 	dma_fifo_cc = sq->dma_fifo_cc;
450 
451 	for (i = 0; i < MLX5E_TX_CQ_POLL_BUDGET; i++) {
452 		struct mlx5_cqe64 *cqe;
453 		u16 wqe_counter;
454 		bool last_wqe;
455 
456 		cqe = mlx5e_get_cqe(cq);
457 		if (!cqe)
458 			break;
459 
460 		mlx5_cqwq_pop(&cq->wq);
461 
462 		wqe_counter = be16_to_cpu(cqe->wqe_counter);
463 
464 		do {
465 			struct mlx5e_tx_wqe_info *wi;
466 			struct sk_buff *skb;
467 			u16 ci;
468 			int j;
469 
470 			last_wqe = (sqcc == wqe_counter);
471 
472 			ci = sqcc & sq->wq.sz_m1;
473 			skb = sq->skb[ci];
474 			wi = &sq->wqe_info[ci];
475 
476 			if (unlikely(!skb)) { /* nop */
477 				sqcc++;
478 				continue;
479 			}
480 
481 			if (unlikely(skb_shinfo(skb)->tx_flags &
482 				     SKBTX_HW_TSTAMP)) {
483 				struct skb_shared_hwtstamps hwts = {};
484 
485 				mlx5e_fill_hwstamp(sq->tstamp,
486 						   get_cqe_ts(cqe), &hwts);
487 				skb_tstamp_tx(skb, &hwts);
488 			}
489 
490 			for (j = 0; j < wi->num_dma; j++) {
491 				struct mlx5e_sq_dma *dma =
492 					mlx5e_dma_get(sq, dma_fifo_cc++);
493 
494 				mlx5e_tx_dma_unmap(sq->pdev, dma);
495 			}
496 
497 			npkts++;
498 			nbytes += wi->num_bytes;
499 			sqcc += wi->num_wqebbs;
500 			napi_consume_skb(skb, napi_budget);
501 		} while (!last_wqe);
502 	}
503 
504 	mlx5_cqwq_update_db_record(&cq->wq);
505 
506 	/* ensure cq space is freed before enabling more cqes */
507 	wmb();
508 
509 	sq->dma_fifo_cc = dma_fifo_cc;
510 	sq->cc = sqcc;
511 
512 	netdev_tx_completed_queue(sq->txq, npkts, nbytes);
513 
514 	if (netif_tx_queue_stopped(sq->txq) &&
515 	    mlx5e_sq_has_room_for(sq, MLX5E_SQ_STOP_ROOM) &&
516 	    likely(test_bit(MLX5E_SQ_STATE_WAKE_TXQ_ENABLE, &sq->state))) {
517 				netif_tx_wake_queue(sq->txq);
518 				sq->stats.wake++;
519 	}
520 
521 	return (i == MLX5E_TX_CQ_POLL_BUDGET);
522 }
523