xref: /linux/drivers/net/ethernet/aquantia/atlantic/aq_ring.c (revision 37744feebc086908fd89760650f458ab19071750)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * aQuantia Corporation Network Driver
4  * Copyright (C) 2014-2019 aQuantia Corporation. All rights reserved
5  */
6 
7 /* File aq_ring.c: Definition of functions for Rx/Tx rings. */
8 
9 #include "aq_ring.h"
10 #include "aq_nic.h"
11 #include "aq_hw.h"
12 #include "aq_hw_utils.h"
13 #include "aq_ptp.h"
14 
15 #include <linux/netdevice.h>
16 #include <linux/etherdevice.h>
17 
18 static inline void aq_free_rxpage(struct aq_rxpage *rxpage, struct device *dev)
19 {
20 	unsigned int len = PAGE_SIZE << rxpage->order;
21 
22 	dma_unmap_page(dev, rxpage->daddr, len, DMA_FROM_DEVICE);
23 
24 	/* Drop the ref for being in the ring. */
25 	__free_pages(rxpage->page, rxpage->order);
26 	rxpage->page = NULL;
27 }
28 
29 static int aq_get_rxpage(struct aq_rxpage *rxpage, unsigned int order,
30 			 struct device *dev)
31 {
32 	struct page *page;
33 	int ret = -ENOMEM;
34 	dma_addr_t daddr;
35 
36 	page = dev_alloc_pages(order);
37 	if (unlikely(!page))
38 		goto err_exit;
39 
40 	daddr = dma_map_page(dev, page, 0, PAGE_SIZE << order,
41 			     DMA_FROM_DEVICE);
42 
43 	if (unlikely(dma_mapping_error(dev, daddr)))
44 		goto free_page;
45 
46 	rxpage->page = page;
47 	rxpage->daddr = daddr;
48 	rxpage->order = order;
49 	rxpage->pg_off = 0;
50 
51 	return 0;
52 
53 free_page:
54 	__free_pages(page, order);
55 
56 err_exit:
57 	return ret;
58 }
59 
60 static int aq_get_rxpages(struct aq_ring_s *self, struct aq_ring_buff_s *rxbuf,
61 			  int order)
62 {
63 	int ret;
64 
65 	if (rxbuf->rxdata.page) {
66 		/* One means ring is the only user and can reuse */
67 		if (page_ref_count(rxbuf->rxdata.page) > 1) {
68 			/* Try reuse buffer */
69 			rxbuf->rxdata.pg_off += AQ_CFG_RX_FRAME_MAX;
70 			if (rxbuf->rxdata.pg_off + AQ_CFG_RX_FRAME_MAX <=
71 				(PAGE_SIZE << order)) {
72 				self->stats.rx.pg_flips++;
73 			} else {
74 				/* Buffer exhausted. We have other users and
75 				 * should release this page and realloc
76 				 */
77 				aq_free_rxpage(&rxbuf->rxdata,
78 					       aq_nic_get_dev(self->aq_nic));
79 				self->stats.rx.pg_losts++;
80 			}
81 		} else {
82 			rxbuf->rxdata.pg_off = 0;
83 			self->stats.rx.pg_reuses++;
84 		}
85 	}
86 
87 	if (!rxbuf->rxdata.page) {
88 		ret = aq_get_rxpage(&rxbuf->rxdata, order,
89 				    aq_nic_get_dev(self->aq_nic));
90 		return ret;
91 	}
92 
93 	return 0;
94 }
95 
96 static struct aq_ring_s *aq_ring_alloc(struct aq_ring_s *self,
97 				       struct aq_nic_s *aq_nic)
98 {
99 	int err = 0;
100 
101 	self->buff_ring =
102 		kcalloc(self->size, sizeof(struct aq_ring_buff_s), GFP_KERNEL);
103 
104 	if (!self->buff_ring) {
105 		err = -ENOMEM;
106 		goto err_exit;
107 	}
108 	self->dx_ring = dma_alloc_coherent(aq_nic_get_dev(aq_nic),
109 					   self->size * self->dx_size,
110 					   &self->dx_ring_pa, GFP_KERNEL);
111 	if (!self->dx_ring) {
112 		err = -ENOMEM;
113 		goto err_exit;
114 	}
115 
116 err_exit:
117 	if (err < 0) {
118 		aq_ring_free(self);
119 		self = NULL;
120 	}
121 
122 	return self;
123 }
124 
125 struct aq_ring_s *aq_ring_tx_alloc(struct aq_ring_s *self,
126 				   struct aq_nic_s *aq_nic,
127 				   unsigned int idx,
128 				   struct aq_nic_cfg_s *aq_nic_cfg)
129 {
130 	int err = 0;
131 
132 	self->aq_nic = aq_nic;
133 	self->idx = idx;
134 	self->size = aq_nic_cfg->txds;
135 	self->dx_size = aq_nic_cfg->aq_hw_caps->txd_size;
136 
137 	self = aq_ring_alloc(self, aq_nic);
138 	if (!self) {
139 		err = -ENOMEM;
140 		goto err_exit;
141 	}
142 
143 err_exit:
144 	if (err < 0) {
145 		aq_ring_free(self);
146 		self = NULL;
147 	}
148 
149 	return self;
150 }
151 
152 struct aq_ring_s *aq_ring_rx_alloc(struct aq_ring_s *self,
153 				   struct aq_nic_s *aq_nic,
154 				   unsigned int idx,
155 				   struct aq_nic_cfg_s *aq_nic_cfg)
156 {
157 	int err = 0;
158 
159 	self->aq_nic = aq_nic;
160 	self->idx = idx;
161 	self->size = aq_nic_cfg->rxds;
162 	self->dx_size = aq_nic_cfg->aq_hw_caps->rxd_size;
163 	self->page_order = fls(AQ_CFG_RX_FRAME_MAX / PAGE_SIZE +
164 			       (AQ_CFG_RX_FRAME_MAX % PAGE_SIZE ? 1 : 0)) - 1;
165 
166 	if (aq_nic_cfg->rxpageorder > self->page_order)
167 		self->page_order = aq_nic_cfg->rxpageorder;
168 
169 	self = aq_ring_alloc(self, aq_nic);
170 	if (!self) {
171 		err = -ENOMEM;
172 		goto err_exit;
173 	}
174 
175 err_exit:
176 	if (err < 0) {
177 		aq_ring_free(self);
178 		self = NULL;
179 	}
180 
181 	return self;
182 }
183 
184 struct aq_ring_s *
185 aq_ring_hwts_rx_alloc(struct aq_ring_s *self, struct aq_nic_s *aq_nic,
186 		      unsigned int idx, unsigned int size, unsigned int dx_size)
187 {
188 	struct device *dev = aq_nic_get_dev(aq_nic);
189 	size_t sz = size * dx_size + AQ_CFG_RXDS_DEF;
190 
191 	memset(self, 0, sizeof(*self));
192 
193 	self->aq_nic = aq_nic;
194 	self->idx = idx;
195 	self->size = size;
196 	self->dx_size = dx_size;
197 
198 	self->dx_ring = dma_alloc_coherent(dev, sz, &self->dx_ring_pa,
199 					   GFP_KERNEL);
200 	if (!self->dx_ring) {
201 		aq_ring_free(self);
202 		return NULL;
203 	}
204 
205 	return self;
206 }
207 
208 int aq_ring_init(struct aq_ring_s *self)
209 {
210 	self->hw_head = 0;
211 	self->sw_head = 0;
212 	self->sw_tail = 0;
213 
214 	return 0;
215 }
216 
217 static inline bool aq_ring_dx_in_range(unsigned int h, unsigned int i,
218 				       unsigned int t)
219 {
220 	return (h < t) ? ((h < i) && (i < t)) : ((h < i) || (i < t));
221 }
222 
223 void aq_ring_update_queue_state(struct aq_ring_s *ring)
224 {
225 	if (aq_ring_avail_dx(ring) <= AQ_CFG_SKB_FRAGS_MAX)
226 		aq_ring_queue_stop(ring);
227 	else if (aq_ring_avail_dx(ring) > AQ_CFG_RESTART_DESC_THRES)
228 		aq_ring_queue_wake(ring);
229 }
230 
231 void aq_ring_queue_wake(struct aq_ring_s *ring)
232 {
233 	struct net_device *ndev = aq_nic_get_ndev(ring->aq_nic);
234 
235 	if (__netif_subqueue_stopped(ndev, ring->idx)) {
236 		netif_wake_subqueue(ndev, ring->idx);
237 		ring->stats.tx.queue_restarts++;
238 	}
239 }
240 
241 void aq_ring_queue_stop(struct aq_ring_s *ring)
242 {
243 	struct net_device *ndev = aq_nic_get_ndev(ring->aq_nic);
244 
245 	if (!__netif_subqueue_stopped(ndev, ring->idx))
246 		netif_stop_subqueue(ndev, ring->idx);
247 }
248 
249 bool aq_ring_tx_clean(struct aq_ring_s *self)
250 {
251 	struct device *dev = aq_nic_get_dev(self->aq_nic);
252 	unsigned int budget;
253 
254 	for (budget = AQ_CFG_TX_CLEAN_BUDGET;
255 	     budget && self->sw_head != self->hw_head; budget--) {
256 		struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
257 
258 		if (likely(buff->is_mapped)) {
259 			if (unlikely(buff->is_sop)) {
260 				if (!buff->is_eop &&
261 				    buff->eop_index != 0xffffU &&
262 				    (!aq_ring_dx_in_range(self->sw_head,
263 						buff->eop_index,
264 						self->hw_head)))
265 					break;
266 
267 				dma_unmap_single(dev, buff->pa, buff->len,
268 						 DMA_TO_DEVICE);
269 			} else {
270 				dma_unmap_page(dev, buff->pa, buff->len,
271 					       DMA_TO_DEVICE);
272 			}
273 		}
274 
275 		if (unlikely(buff->is_eop)) {
276 			++self->stats.rx.packets;
277 			self->stats.tx.bytes += buff->skb->len;
278 
279 			dev_kfree_skb_any(buff->skb);
280 		}
281 		buff->pa = 0U;
282 		buff->eop_index = 0xffffU;
283 		self->sw_head = aq_ring_next_dx(self, self->sw_head);
284 	}
285 
286 	return !!budget;
287 }
288 
289 static void aq_rx_checksum(struct aq_ring_s *self,
290 			   struct aq_ring_buff_s *buff,
291 			   struct sk_buff *skb)
292 {
293 	if (!(self->aq_nic->ndev->features & NETIF_F_RXCSUM))
294 		return;
295 
296 	if (unlikely(buff->is_cso_err)) {
297 		++self->stats.rx.errors;
298 		skb->ip_summed = CHECKSUM_NONE;
299 		return;
300 	}
301 	if (buff->is_ip_cso) {
302 		__skb_incr_checksum_unnecessary(skb);
303 	} else {
304 		skb->ip_summed = CHECKSUM_NONE;
305 	}
306 
307 	if (buff->is_udp_cso || buff->is_tcp_cso)
308 		__skb_incr_checksum_unnecessary(skb);
309 }
310 
311 #define AQ_SKB_ALIGN SKB_DATA_ALIGN(sizeof(struct skb_shared_info))
312 int aq_ring_rx_clean(struct aq_ring_s *self,
313 		     struct napi_struct *napi,
314 		     int *work_done,
315 		     int budget)
316 {
317 	struct net_device *ndev = aq_nic_get_ndev(self->aq_nic);
318 	bool is_rsc_completed = true;
319 	int err = 0;
320 
321 	for (; (self->sw_head != self->hw_head) && budget;
322 		self->sw_head = aq_ring_next_dx(self, self->sw_head),
323 		--budget, ++(*work_done)) {
324 		struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
325 		bool is_ptp_ring = aq_ptp_ring(self->aq_nic, self);
326 		struct aq_ring_buff_s *buff_ = NULL;
327 		struct sk_buff *skb = NULL;
328 		unsigned int next_ = 0U;
329 		unsigned int i = 0U;
330 		u16 hdr_len;
331 
332 		if (buff->is_cleaned)
333 			continue;
334 
335 		if (!buff->is_eop) {
336 			buff_ = buff;
337 			do {
338 				next_ = buff_->next,
339 				buff_ = &self->buff_ring[next_];
340 				is_rsc_completed =
341 					aq_ring_dx_in_range(self->sw_head,
342 							    next_,
343 							    self->hw_head);
344 
345 				if (unlikely(!is_rsc_completed))
346 					break;
347 
348 				buff->is_error |= buff_->is_error;
349 				buff->is_cso_err |= buff_->is_cso_err;
350 
351 			} while (!buff_->is_eop);
352 
353 			if (!is_rsc_completed) {
354 				err = 0;
355 				goto err_exit;
356 			}
357 			if (buff->is_error ||
358 			    (buff->is_lro && buff->is_cso_err)) {
359 				buff_ = buff;
360 				do {
361 					next_ = buff_->next,
362 					buff_ = &self->buff_ring[next_];
363 
364 					buff_->is_cleaned = true;
365 				} while (!buff_->is_eop);
366 
367 				++self->stats.rx.errors;
368 				continue;
369 			}
370 		}
371 
372 		if (buff->is_error) {
373 			++self->stats.rx.errors;
374 			continue;
375 		}
376 
377 		dma_sync_single_range_for_cpu(aq_nic_get_dev(self->aq_nic),
378 					      buff->rxdata.daddr,
379 					      buff->rxdata.pg_off,
380 					      buff->len, DMA_FROM_DEVICE);
381 
382 		/* for single fragment packets use build_skb() */
383 		if (buff->is_eop &&
384 		    buff->len <= AQ_CFG_RX_FRAME_MAX - AQ_SKB_ALIGN) {
385 			skb = build_skb(aq_buf_vaddr(&buff->rxdata),
386 					AQ_CFG_RX_FRAME_MAX);
387 			if (unlikely(!skb)) {
388 				err = -ENOMEM;
389 				goto err_exit;
390 			}
391 			if (is_ptp_ring)
392 				buff->len -=
393 					aq_ptp_extract_ts(self->aq_nic, skb,
394 						aq_buf_vaddr(&buff->rxdata),
395 						buff->len);
396 			skb_put(skb, buff->len);
397 			page_ref_inc(buff->rxdata.page);
398 		} else {
399 			skb = napi_alloc_skb(napi, AQ_CFG_RX_HDR_SIZE);
400 			if (unlikely(!skb)) {
401 				err = -ENOMEM;
402 				goto err_exit;
403 			}
404 			if (is_ptp_ring)
405 				buff->len -=
406 					aq_ptp_extract_ts(self->aq_nic, skb,
407 						aq_buf_vaddr(&buff->rxdata),
408 						buff->len);
409 
410 			hdr_len = buff->len;
411 			if (hdr_len > AQ_CFG_RX_HDR_SIZE)
412 				hdr_len = eth_get_headlen(skb->dev,
413 							  aq_buf_vaddr(&buff->rxdata),
414 							  AQ_CFG_RX_HDR_SIZE);
415 
416 			memcpy(__skb_put(skb, hdr_len), aq_buf_vaddr(&buff->rxdata),
417 			       ALIGN(hdr_len, sizeof(long)));
418 
419 			if (buff->len - hdr_len > 0) {
420 				skb_add_rx_frag(skb, 0, buff->rxdata.page,
421 						buff->rxdata.pg_off + hdr_len,
422 						buff->len - hdr_len,
423 						AQ_CFG_RX_FRAME_MAX);
424 				page_ref_inc(buff->rxdata.page);
425 			}
426 
427 			if (!buff->is_eop) {
428 				buff_ = buff;
429 				i = 1U;
430 				do {
431 					next_ = buff_->next,
432 					buff_ = &self->buff_ring[next_];
433 
434 					dma_sync_single_range_for_cpu(
435 							aq_nic_get_dev(self->aq_nic),
436 							buff_->rxdata.daddr,
437 							buff_->rxdata.pg_off,
438 							buff_->len,
439 							DMA_FROM_DEVICE);
440 					skb_add_rx_frag(skb, i++,
441 							buff_->rxdata.page,
442 							buff_->rxdata.pg_off,
443 							buff_->len,
444 							AQ_CFG_RX_FRAME_MAX);
445 					page_ref_inc(buff_->rxdata.page);
446 					buff_->is_cleaned = 1;
447 
448 					buff->is_ip_cso &= buff_->is_ip_cso;
449 					buff->is_udp_cso &= buff_->is_udp_cso;
450 					buff->is_tcp_cso &= buff_->is_tcp_cso;
451 					buff->is_cso_err |= buff_->is_cso_err;
452 
453 				} while (!buff_->is_eop);
454 			}
455 		}
456 
457 		if (buff->is_vlan)
458 			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
459 					       buff->vlan_rx_tag);
460 
461 		skb->protocol = eth_type_trans(skb, ndev);
462 
463 		aq_rx_checksum(self, buff, skb);
464 
465 		skb_set_hash(skb, buff->rss_hash,
466 			     buff->is_hash_l4 ? PKT_HASH_TYPE_L4 :
467 			     PKT_HASH_TYPE_NONE);
468 		/* Send all PTP traffic to 0 queue */
469 		skb_record_rx_queue(skb, is_ptp_ring ? 0 : self->idx);
470 
471 		++self->stats.rx.packets;
472 		self->stats.rx.bytes += skb->len;
473 
474 		napi_gro_receive(napi, skb);
475 	}
476 
477 err_exit:
478 	return err;
479 }
480 
481 void aq_ring_hwts_rx_clean(struct aq_ring_s *self, struct aq_nic_s *aq_nic)
482 {
483 	while (self->sw_head != self->hw_head) {
484 		u64 ns;
485 
486 		aq_nic->aq_hw_ops->extract_hwts(aq_nic->aq_hw,
487 						self->dx_ring +
488 						(self->sw_head * self->dx_size),
489 						self->dx_size, &ns);
490 		aq_ptp_tx_hwtstamp(aq_nic, ns);
491 
492 		self->sw_head = aq_ring_next_dx(self, self->sw_head);
493 	}
494 }
495 
496 int aq_ring_rx_fill(struct aq_ring_s *self)
497 {
498 	unsigned int page_order = self->page_order;
499 	struct aq_ring_buff_s *buff = NULL;
500 	int err = 0;
501 	int i = 0;
502 
503 	if (aq_ring_avail_dx(self) < min_t(unsigned int, AQ_CFG_RX_REFILL_THRES,
504 					   self->size / 2))
505 		return err;
506 
507 	for (i = aq_ring_avail_dx(self); i--;
508 		self->sw_tail = aq_ring_next_dx(self, self->sw_tail)) {
509 		buff = &self->buff_ring[self->sw_tail];
510 
511 		buff->flags = 0U;
512 		buff->len = AQ_CFG_RX_FRAME_MAX;
513 
514 		err = aq_get_rxpages(self, buff, page_order);
515 		if (err)
516 			goto err_exit;
517 
518 		buff->pa = aq_buf_daddr(&buff->rxdata);
519 		buff = NULL;
520 	}
521 
522 err_exit:
523 	return err;
524 }
525 
526 void aq_ring_rx_deinit(struct aq_ring_s *self)
527 {
528 	if (!self)
529 		goto err_exit;
530 
531 	for (; self->sw_head != self->sw_tail;
532 		self->sw_head = aq_ring_next_dx(self, self->sw_head)) {
533 		struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
534 
535 		aq_free_rxpage(&buff->rxdata, aq_nic_get_dev(self->aq_nic));
536 	}
537 
538 err_exit:;
539 }
540 
541 void aq_ring_free(struct aq_ring_s *self)
542 {
543 	if (!self)
544 		goto err_exit;
545 
546 	kfree(self->buff_ring);
547 
548 	if (self->dx_ring)
549 		dma_free_coherent(aq_nic_get_dev(self->aq_nic),
550 				  self->size * self->dx_size, self->dx_ring,
551 				  self->dx_ring_pa);
552 
553 err_exit:;
554 }
555