1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Atlantic Network Driver
3  *
4  * Copyright (C) 2014-2019 aQuantia Corporation
5  * Copyright (C) 2019-2020 Marvell International Ltd.
6  */
7 
8 /* File aq_ring.c: Definition of functions for Rx/Tx rings. */
9 
10 #include "aq_ring.h"
11 #include "aq_nic.h"
12 #include "aq_hw.h"
13 #include "aq_hw_utils.h"
14 #include "aq_ptp.h"
15 
16 #include <linux/netdevice.h>
17 #include <linux/etherdevice.h>
18 
19 static inline void aq_free_rxpage(struct aq_rxpage *rxpage, struct device *dev)
20 {
21 	unsigned int len = PAGE_SIZE << rxpage->order;
22 
23 	dma_unmap_page(dev, rxpage->daddr, len, DMA_FROM_DEVICE);
24 
25 	/* Drop the ref for being in the ring. */
26 	__free_pages(rxpage->page, rxpage->order);
27 	rxpage->page = NULL;
28 }
29 
30 static int aq_get_rxpage(struct aq_rxpage *rxpage, unsigned int order,
31 			 struct device *dev)
32 {
33 	struct page *page;
34 	int ret = -ENOMEM;
35 	dma_addr_t daddr;
36 
37 	page = dev_alloc_pages(order);
38 	if (unlikely(!page))
39 		goto err_exit;
40 
41 	daddr = dma_map_page(dev, page, 0, PAGE_SIZE << order,
42 			     DMA_FROM_DEVICE);
43 
44 	if (unlikely(dma_mapping_error(dev, daddr)))
45 		goto free_page;
46 
47 	rxpage->page = page;
48 	rxpage->daddr = daddr;
49 	rxpage->order = order;
50 	rxpage->pg_off = 0;
51 
52 	return 0;
53 
54 free_page:
55 	__free_pages(page, order);
56 
57 err_exit:
58 	return ret;
59 }
60 
61 static int aq_get_rxpages(struct aq_ring_s *self, struct aq_ring_buff_s *rxbuf,
62 			  int order)
63 {
64 	int ret;
65 
66 	if (rxbuf->rxdata.page) {
67 		/* One means ring is the only user and can reuse */
68 		if (page_ref_count(rxbuf->rxdata.page) > 1) {
69 			/* Try reuse buffer */
70 			rxbuf->rxdata.pg_off += AQ_CFG_RX_FRAME_MAX;
71 			if (rxbuf->rxdata.pg_off + AQ_CFG_RX_FRAME_MAX <=
72 				(PAGE_SIZE << order)) {
73 				u64_stats_update_begin(&self->stats.rx.syncp);
74 				self->stats.rx.pg_flips++;
75 				u64_stats_update_end(&self->stats.rx.syncp);
76 			} else {
77 				/* Buffer exhausted. We have other users and
78 				 * should release this page and realloc
79 				 */
80 				aq_free_rxpage(&rxbuf->rxdata,
81 					       aq_nic_get_dev(self->aq_nic));
82 				u64_stats_update_begin(&self->stats.rx.syncp);
83 				self->stats.rx.pg_losts++;
84 				u64_stats_update_end(&self->stats.rx.syncp);
85 			}
86 		} else {
87 			rxbuf->rxdata.pg_off = 0;
88 			u64_stats_update_begin(&self->stats.rx.syncp);
89 			self->stats.rx.pg_reuses++;
90 			u64_stats_update_end(&self->stats.rx.syncp);
91 		}
92 	}
93 
94 	if (!rxbuf->rxdata.page) {
95 		ret = aq_get_rxpage(&rxbuf->rxdata, order,
96 				    aq_nic_get_dev(self->aq_nic));
97 		if (ret) {
98 			u64_stats_update_begin(&self->stats.rx.syncp);
99 			self->stats.rx.alloc_fails++;
100 			u64_stats_update_end(&self->stats.rx.syncp);
101 		}
102 		return ret;
103 	}
104 
105 	return 0;
106 }
107 
108 static struct aq_ring_s *aq_ring_alloc(struct aq_ring_s *self,
109 				       struct aq_nic_s *aq_nic)
110 {
111 	int err = 0;
112 
113 	self->buff_ring =
114 		kcalloc(self->size, sizeof(struct aq_ring_buff_s), GFP_KERNEL);
115 
116 	if (!self->buff_ring) {
117 		err = -ENOMEM;
118 		goto err_exit;
119 	}
120 	self->dx_ring = dma_alloc_coherent(aq_nic_get_dev(aq_nic),
121 					   self->size * self->dx_size,
122 					   &self->dx_ring_pa, GFP_KERNEL);
123 	if (!self->dx_ring) {
124 		err = -ENOMEM;
125 		goto err_exit;
126 	}
127 
128 err_exit:
129 	if (err < 0) {
130 		aq_ring_free(self);
131 		self = NULL;
132 	}
133 
134 	return self;
135 }
136 
137 struct aq_ring_s *aq_ring_tx_alloc(struct aq_ring_s *self,
138 				   struct aq_nic_s *aq_nic,
139 				   unsigned int idx,
140 				   struct aq_nic_cfg_s *aq_nic_cfg)
141 {
142 	int err = 0;
143 
144 	self->aq_nic = aq_nic;
145 	self->idx = idx;
146 	self->size = aq_nic_cfg->txds;
147 	self->dx_size = aq_nic_cfg->aq_hw_caps->txd_size;
148 
149 	self = aq_ring_alloc(self, aq_nic);
150 	if (!self) {
151 		err = -ENOMEM;
152 		goto err_exit;
153 	}
154 
155 err_exit:
156 	if (err < 0) {
157 		aq_ring_free(self);
158 		self = NULL;
159 	}
160 
161 	return self;
162 }
163 
164 struct aq_ring_s *aq_ring_rx_alloc(struct aq_ring_s *self,
165 				   struct aq_nic_s *aq_nic,
166 				   unsigned int idx,
167 				   struct aq_nic_cfg_s *aq_nic_cfg)
168 {
169 	int err = 0;
170 
171 	self->aq_nic = aq_nic;
172 	self->idx = idx;
173 	self->size = aq_nic_cfg->rxds;
174 	self->dx_size = aq_nic_cfg->aq_hw_caps->rxd_size;
175 	self->page_order = fls(AQ_CFG_RX_FRAME_MAX / PAGE_SIZE +
176 			       (AQ_CFG_RX_FRAME_MAX % PAGE_SIZE ? 1 : 0)) - 1;
177 
178 	if (aq_nic_cfg->rxpageorder > self->page_order)
179 		self->page_order = aq_nic_cfg->rxpageorder;
180 
181 	self = aq_ring_alloc(self, aq_nic);
182 	if (!self) {
183 		err = -ENOMEM;
184 		goto err_exit;
185 	}
186 
187 err_exit:
188 	if (err < 0) {
189 		aq_ring_free(self);
190 		self = NULL;
191 	}
192 
193 	return self;
194 }
195 
196 struct aq_ring_s *
197 aq_ring_hwts_rx_alloc(struct aq_ring_s *self, struct aq_nic_s *aq_nic,
198 		      unsigned int idx, unsigned int size, unsigned int dx_size)
199 {
200 	struct device *dev = aq_nic_get_dev(aq_nic);
201 	size_t sz = size * dx_size + AQ_CFG_RXDS_DEF;
202 
203 	memset(self, 0, sizeof(*self));
204 
205 	self->aq_nic = aq_nic;
206 	self->idx = idx;
207 	self->size = size;
208 	self->dx_size = dx_size;
209 
210 	self->dx_ring = dma_alloc_coherent(dev, sz, &self->dx_ring_pa,
211 					   GFP_KERNEL);
212 	if (!self->dx_ring) {
213 		aq_ring_free(self);
214 		return NULL;
215 	}
216 
217 	return self;
218 }
219 
220 int aq_ring_init(struct aq_ring_s *self, const enum atl_ring_type ring_type)
221 {
222 	self->hw_head = 0;
223 	self->sw_head = 0;
224 	self->sw_tail = 0;
225 	self->ring_type = ring_type;
226 
227 	if (self->ring_type == ATL_RING_RX)
228 		u64_stats_init(&self->stats.rx.syncp);
229 	else
230 		u64_stats_init(&self->stats.tx.syncp);
231 
232 	return 0;
233 }
234 
235 static inline bool aq_ring_dx_in_range(unsigned int h, unsigned int i,
236 				       unsigned int t)
237 {
238 	return (h < t) ? ((h < i) && (i < t)) : ((h < i) || (i < t));
239 }
240 
241 void aq_ring_update_queue_state(struct aq_ring_s *ring)
242 {
243 	if (aq_ring_avail_dx(ring) <= AQ_CFG_SKB_FRAGS_MAX)
244 		aq_ring_queue_stop(ring);
245 	else if (aq_ring_avail_dx(ring) > AQ_CFG_RESTART_DESC_THRES)
246 		aq_ring_queue_wake(ring);
247 }
248 
249 void aq_ring_queue_wake(struct aq_ring_s *ring)
250 {
251 	struct net_device *ndev = aq_nic_get_ndev(ring->aq_nic);
252 
253 	if (__netif_subqueue_stopped(ndev,
254 				     AQ_NIC_RING2QMAP(ring->aq_nic,
255 						      ring->idx))) {
256 		netif_wake_subqueue(ndev,
257 				    AQ_NIC_RING2QMAP(ring->aq_nic, ring->idx));
258 		u64_stats_update_begin(&ring->stats.tx.syncp);
259 		ring->stats.tx.queue_restarts++;
260 		u64_stats_update_end(&ring->stats.tx.syncp);
261 	}
262 }
263 
264 void aq_ring_queue_stop(struct aq_ring_s *ring)
265 {
266 	struct net_device *ndev = aq_nic_get_ndev(ring->aq_nic);
267 
268 	if (!__netif_subqueue_stopped(ndev,
269 				      AQ_NIC_RING2QMAP(ring->aq_nic,
270 						       ring->idx)))
271 		netif_stop_subqueue(ndev,
272 				    AQ_NIC_RING2QMAP(ring->aq_nic, ring->idx));
273 }
274 
275 bool aq_ring_tx_clean(struct aq_ring_s *self)
276 {
277 	struct device *dev = aq_nic_get_dev(self->aq_nic);
278 	unsigned int budget;
279 
280 	for (budget = AQ_CFG_TX_CLEAN_BUDGET;
281 	     budget && self->sw_head != self->hw_head; budget--) {
282 		struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
283 
284 		if (likely(buff->is_mapped)) {
285 			if (unlikely(buff->is_sop)) {
286 				if (!buff->is_eop &&
287 				    buff->eop_index != 0xffffU &&
288 				    (!aq_ring_dx_in_range(self->sw_head,
289 						buff->eop_index,
290 						self->hw_head)))
291 					break;
292 
293 				dma_unmap_single(dev, buff->pa, buff->len,
294 						 DMA_TO_DEVICE);
295 			} else {
296 				dma_unmap_page(dev, buff->pa, buff->len,
297 					       DMA_TO_DEVICE);
298 			}
299 		}
300 
301 		if (unlikely(buff->is_eop && buff->skb)) {
302 			u64_stats_update_begin(&self->stats.tx.syncp);
303 			++self->stats.tx.packets;
304 			self->stats.tx.bytes += buff->skb->len;
305 			u64_stats_update_end(&self->stats.tx.syncp);
306 
307 			dev_kfree_skb_any(buff->skb);
308 			buff->skb = NULL;
309 		}
310 		buff->pa = 0U;
311 		buff->eop_index = 0xffffU;
312 		self->sw_head = aq_ring_next_dx(self, self->sw_head);
313 	}
314 
315 	return !!budget;
316 }
317 
318 static void aq_rx_checksum(struct aq_ring_s *self,
319 			   struct aq_ring_buff_s *buff,
320 			   struct sk_buff *skb)
321 {
322 	if (!(self->aq_nic->ndev->features & NETIF_F_RXCSUM))
323 		return;
324 
325 	if (unlikely(buff->is_cso_err)) {
326 		u64_stats_update_begin(&self->stats.rx.syncp);
327 		++self->stats.rx.errors;
328 		u64_stats_update_end(&self->stats.rx.syncp);
329 		skb->ip_summed = CHECKSUM_NONE;
330 		return;
331 	}
332 	if (buff->is_ip_cso) {
333 		__skb_incr_checksum_unnecessary(skb);
334 	} else {
335 		skb->ip_summed = CHECKSUM_NONE;
336 	}
337 
338 	if (buff->is_udp_cso || buff->is_tcp_cso)
339 		__skb_incr_checksum_unnecessary(skb);
340 }
341 
342 #define AQ_SKB_ALIGN SKB_DATA_ALIGN(sizeof(struct skb_shared_info))
343 int aq_ring_rx_clean(struct aq_ring_s *self,
344 		     struct napi_struct *napi,
345 		     int *work_done,
346 		     int budget)
347 {
348 	struct net_device *ndev = aq_nic_get_ndev(self->aq_nic);
349 	bool is_rsc_completed = true;
350 	int err = 0;
351 
352 	for (; (self->sw_head != self->hw_head) && budget;
353 		self->sw_head = aq_ring_next_dx(self, self->sw_head),
354 		--budget, ++(*work_done)) {
355 		struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
356 		bool is_ptp_ring = aq_ptp_ring(self->aq_nic, self);
357 		struct aq_ring_buff_s *buff_ = NULL;
358 		struct sk_buff *skb = NULL;
359 		unsigned int next_ = 0U;
360 		unsigned int i = 0U;
361 		u16 hdr_len;
362 
363 		if (buff->is_cleaned)
364 			continue;
365 
366 		if (!buff->is_eop) {
367 			buff_ = buff;
368 			do {
369 				if (buff_->next >= self->size) {
370 					err = -EIO;
371 					goto err_exit;
372 				}
373 				next_ = buff_->next,
374 				buff_ = &self->buff_ring[next_];
375 				is_rsc_completed =
376 					aq_ring_dx_in_range(self->sw_head,
377 							    next_,
378 							    self->hw_head);
379 
380 				if (unlikely(!is_rsc_completed))
381 					break;
382 
383 				buff->is_error |= buff_->is_error;
384 				buff->is_cso_err |= buff_->is_cso_err;
385 
386 			} while (!buff_->is_eop);
387 
388 			if (!is_rsc_completed) {
389 				err = 0;
390 				goto err_exit;
391 			}
392 			if (buff->is_error ||
393 			    (buff->is_lro && buff->is_cso_err)) {
394 				buff_ = buff;
395 				do {
396 					if (buff_->next >= self->size) {
397 						err = -EIO;
398 						goto err_exit;
399 					}
400 					next_ = buff_->next,
401 					buff_ = &self->buff_ring[next_];
402 
403 					buff_->is_cleaned = true;
404 				} while (!buff_->is_eop);
405 
406 				u64_stats_update_begin(&self->stats.rx.syncp);
407 				++self->stats.rx.errors;
408 				u64_stats_update_end(&self->stats.rx.syncp);
409 				continue;
410 			}
411 		}
412 
413 		if (buff->is_error) {
414 			u64_stats_update_begin(&self->stats.rx.syncp);
415 			++self->stats.rx.errors;
416 			u64_stats_update_end(&self->stats.rx.syncp);
417 			continue;
418 		}
419 
420 		dma_sync_single_range_for_cpu(aq_nic_get_dev(self->aq_nic),
421 					      buff->rxdata.daddr,
422 					      buff->rxdata.pg_off,
423 					      buff->len, DMA_FROM_DEVICE);
424 
425 		skb = napi_alloc_skb(napi, AQ_CFG_RX_HDR_SIZE);
426 		if (unlikely(!skb)) {
427 			u64_stats_update_begin(&self->stats.rx.syncp);
428 			self->stats.rx.skb_alloc_fails++;
429 			u64_stats_update_end(&self->stats.rx.syncp);
430 			err = -ENOMEM;
431 			goto err_exit;
432 		}
433 		if (is_ptp_ring)
434 			buff->len -=
435 				aq_ptp_extract_ts(self->aq_nic, skb,
436 						  aq_buf_vaddr(&buff->rxdata),
437 						  buff->len);
438 
439 		hdr_len = buff->len;
440 		if (hdr_len > AQ_CFG_RX_HDR_SIZE)
441 			hdr_len = eth_get_headlen(skb->dev,
442 						  aq_buf_vaddr(&buff->rxdata),
443 						  AQ_CFG_RX_HDR_SIZE);
444 
445 		memcpy(__skb_put(skb, hdr_len), aq_buf_vaddr(&buff->rxdata),
446 		       ALIGN(hdr_len, sizeof(long)));
447 
448 		if (buff->len - hdr_len > 0) {
449 			skb_add_rx_frag(skb, 0, buff->rxdata.page,
450 					buff->rxdata.pg_off + hdr_len,
451 					buff->len - hdr_len,
452 					AQ_CFG_RX_FRAME_MAX);
453 			page_ref_inc(buff->rxdata.page);
454 		}
455 
456 		if (!buff->is_eop) {
457 			buff_ = buff;
458 			i = 1U;
459 			do {
460 				next_ = buff_->next;
461 				buff_ = &self->buff_ring[next_];
462 
463 				dma_sync_single_range_for_cpu(aq_nic_get_dev(self->aq_nic),
464 							      buff_->rxdata.daddr,
465 							      buff_->rxdata.pg_off,
466 							      buff_->len,
467 							      DMA_FROM_DEVICE);
468 				skb_add_rx_frag(skb, i++,
469 						buff_->rxdata.page,
470 						buff_->rxdata.pg_off,
471 						buff_->len,
472 						AQ_CFG_RX_FRAME_MAX);
473 				page_ref_inc(buff_->rxdata.page);
474 				buff_->is_cleaned = 1;
475 
476 				buff->is_ip_cso &= buff_->is_ip_cso;
477 				buff->is_udp_cso &= buff_->is_udp_cso;
478 				buff->is_tcp_cso &= buff_->is_tcp_cso;
479 				buff->is_cso_err |= buff_->is_cso_err;
480 
481 			} while (!buff_->is_eop);
482 		}
483 
484 		if (buff->is_vlan)
485 			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
486 					       buff->vlan_rx_tag);
487 
488 		skb->protocol = eth_type_trans(skb, ndev);
489 
490 		aq_rx_checksum(self, buff, skb);
491 
492 		skb_set_hash(skb, buff->rss_hash,
493 			     buff->is_hash_l4 ? PKT_HASH_TYPE_L4 :
494 			     PKT_HASH_TYPE_NONE);
495 		/* Send all PTP traffic to 0 queue */
496 		skb_record_rx_queue(skb,
497 				    is_ptp_ring ? 0
498 						: AQ_NIC_RING2QMAP(self->aq_nic,
499 								   self->idx));
500 
501 		u64_stats_update_begin(&self->stats.rx.syncp);
502 		++self->stats.rx.packets;
503 		self->stats.rx.bytes += skb->len;
504 		u64_stats_update_end(&self->stats.rx.syncp);
505 
506 		napi_gro_receive(napi, skb);
507 	}
508 
509 err_exit:
510 	return err;
511 }
512 
513 void aq_ring_hwts_rx_clean(struct aq_ring_s *self, struct aq_nic_s *aq_nic)
514 {
515 #if IS_REACHABLE(CONFIG_PTP_1588_CLOCK)
516 	while (self->sw_head != self->hw_head) {
517 		u64 ns;
518 
519 		aq_nic->aq_hw_ops->extract_hwts(aq_nic->aq_hw,
520 						self->dx_ring +
521 						(self->sw_head * self->dx_size),
522 						self->dx_size, &ns);
523 		aq_ptp_tx_hwtstamp(aq_nic, ns);
524 
525 		self->sw_head = aq_ring_next_dx(self, self->sw_head);
526 	}
527 #endif
528 }
529 
530 int aq_ring_rx_fill(struct aq_ring_s *self)
531 {
532 	unsigned int page_order = self->page_order;
533 	struct aq_ring_buff_s *buff = NULL;
534 	int err = 0;
535 	int i = 0;
536 
537 	if (aq_ring_avail_dx(self) < min_t(unsigned int, AQ_CFG_RX_REFILL_THRES,
538 					   self->size / 2))
539 		return err;
540 
541 	for (i = aq_ring_avail_dx(self); i--;
542 		self->sw_tail = aq_ring_next_dx(self, self->sw_tail)) {
543 		buff = &self->buff_ring[self->sw_tail];
544 
545 		buff->flags = 0U;
546 		buff->len = AQ_CFG_RX_FRAME_MAX;
547 
548 		err = aq_get_rxpages(self, buff, page_order);
549 		if (err)
550 			goto err_exit;
551 
552 		buff->pa = aq_buf_daddr(&buff->rxdata);
553 		buff = NULL;
554 	}
555 
556 err_exit:
557 	return err;
558 }
559 
560 void aq_ring_rx_deinit(struct aq_ring_s *self)
561 {
562 	if (!self)
563 		return;
564 
565 	for (; self->sw_head != self->sw_tail;
566 		self->sw_head = aq_ring_next_dx(self, self->sw_head)) {
567 		struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
568 
569 		aq_free_rxpage(&buff->rxdata, aq_nic_get_dev(self->aq_nic));
570 	}
571 }
572 
573 void aq_ring_free(struct aq_ring_s *self)
574 {
575 	if (!self)
576 		return;
577 
578 	kfree(self->buff_ring);
579 
580 	if (self->dx_ring)
581 		dma_free_coherent(aq_nic_get_dev(self->aq_nic),
582 				  self->size * self->dx_size, self->dx_ring,
583 				  self->dx_ring_pa);
584 }
585 
586 unsigned int aq_ring_fill_stats_data(struct aq_ring_s *self, u64 *data)
587 {
588 	unsigned int count;
589 	unsigned int start;
590 
591 	if (self->ring_type == ATL_RING_RX) {
592 		/* This data should mimic aq_ethtool_queue_rx_stat_names structure */
593 		do {
594 			count = 0;
595 			start = u64_stats_fetch_begin_irq(&self->stats.rx.syncp);
596 			data[count] = self->stats.rx.packets;
597 			data[++count] = self->stats.rx.jumbo_packets;
598 			data[++count] = self->stats.rx.lro_packets;
599 			data[++count] = self->stats.rx.errors;
600 			data[++count] = self->stats.rx.alloc_fails;
601 			data[++count] = self->stats.rx.skb_alloc_fails;
602 			data[++count] = self->stats.rx.polls;
603 		} while (u64_stats_fetch_retry_irq(&self->stats.rx.syncp, start));
604 	} else {
605 		/* This data should mimic aq_ethtool_queue_tx_stat_names structure */
606 		do {
607 			count = 0;
608 			start = u64_stats_fetch_begin_irq(&self->stats.tx.syncp);
609 			data[count] = self->stats.tx.packets;
610 			data[++count] = self->stats.tx.queue_restarts;
611 		} while (u64_stats_fetch_retry_irq(&self->stats.tx.syncp, start));
612 	}
613 
614 	return ++count;
615 }
616