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 			dev_kfree_skb_any(buff->skb);
277 
278 		buff->pa = 0U;
279 		buff->eop_index = 0xffffU;
280 		self->sw_head = aq_ring_next_dx(self, self->sw_head);
281 	}
282 
283 	return !!budget;
284 }
285 
286 static void aq_rx_checksum(struct aq_ring_s *self,
287 			   struct aq_ring_buff_s *buff,
288 			   struct sk_buff *skb)
289 {
290 	if (!(self->aq_nic->ndev->features & NETIF_F_RXCSUM))
291 		return;
292 
293 	if (unlikely(buff->is_cso_err)) {
294 		++self->stats.rx.errors;
295 		skb->ip_summed = CHECKSUM_NONE;
296 		return;
297 	}
298 	if (buff->is_ip_cso) {
299 		__skb_incr_checksum_unnecessary(skb);
300 	} else {
301 		skb->ip_summed = CHECKSUM_NONE;
302 	}
303 
304 	if (buff->is_udp_cso || buff->is_tcp_cso)
305 		__skb_incr_checksum_unnecessary(skb);
306 }
307 
308 #define AQ_SKB_ALIGN SKB_DATA_ALIGN(sizeof(struct skb_shared_info))
309 int aq_ring_rx_clean(struct aq_ring_s *self,
310 		     struct napi_struct *napi,
311 		     int *work_done,
312 		     int budget)
313 {
314 	struct net_device *ndev = aq_nic_get_ndev(self->aq_nic);
315 	bool is_rsc_completed = true;
316 	int err = 0;
317 
318 	for (; (self->sw_head != self->hw_head) && budget;
319 		self->sw_head = aq_ring_next_dx(self, self->sw_head),
320 		--budget, ++(*work_done)) {
321 		struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
322 		bool is_ptp_ring = aq_ptp_ring(self->aq_nic, self);
323 		struct aq_ring_buff_s *buff_ = NULL;
324 		struct sk_buff *skb = NULL;
325 		unsigned int next_ = 0U;
326 		unsigned int i = 0U;
327 		u16 hdr_len;
328 
329 		if (buff->is_cleaned)
330 			continue;
331 
332 		if (!buff->is_eop) {
333 			buff_ = buff;
334 			do {
335 				next_ = buff_->next,
336 				buff_ = &self->buff_ring[next_];
337 				is_rsc_completed =
338 					aq_ring_dx_in_range(self->sw_head,
339 							    next_,
340 							    self->hw_head);
341 
342 				if (unlikely(!is_rsc_completed))
343 					break;
344 
345 				buff->is_error |= buff_->is_error;
346 				buff->is_cso_err |= buff_->is_cso_err;
347 
348 			} while (!buff_->is_eop);
349 
350 			if (!is_rsc_completed) {
351 				err = 0;
352 				goto err_exit;
353 			}
354 			if (buff->is_error || buff->is_cso_err) {
355 				buff_ = buff;
356 				do {
357 					next_ = buff_->next,
358 					buff_ = &self->buff_ring[next_];
359 
360 					buff_->is_cleaned = true;
361 				} while (!buff_->is_eop);
362 
363 				++self->stats.rx.errors;
364 				continue;
365 			}
366 		}
367 
368 		if (buff->is_error) {
369 			++self->stats.rx.errors;
370 			continue;
371 		}
372 
373 		dma_sync_single_range_for_cpu(aq_nic_get_dev(self->aq_nic),
374 					      buff->rxdata.daddr,
375 					      buff->rxdata.pg_off,
376 					      buff->len, DMA_FROM_DEVICE);
377 
378 		/* for single fragment packets use build_skb() */
379 		if (buff->is_eop &&
380 		    buff->len <= AQ_CFG_RX_FRAME_MAX - AQ_SKB_ALIGN) {
381 			skb = build_skb(aq_buf_vaddr(&buff->rxdata),
382 					AQ_CFG_RX_FRAME_MAX);
383 			if (unlikely(!skb)) {
384 				err = -ENOMEM;
385 				goto err_exit;
386 			}
387 			if (is_ptp_ring)
388 				buff->len -=
389 					aq_ptp_extract_ts(self->aq_nic, skb,
390 						aq_buf_vaddr(&buff->rxdata),
391 						buff->len);
392 			skb_put(skb, buff->len);
393 			page_ref_inc(buff->rxdata.page);
394 		} else {
395 			skb = napi_alloc_skb(napi, AQ_CFG_RX_HDR_SIZE);
396 			if (unlikely(!skb)) {
397 				err = -ENOMEM;
398 				goto err_exit;
399 			}
400 			if (is_ptp_ring)
401 				buff->len -=
402 					aq_ptp_extract_ts(self->aq_nic, skb,
403 						aq_buf_vaddr(&buff->rxdata),
404 						buff->len);
405 
406 			hdr_len = buff->len;
407 			if (hdr_len > AQ_CFG_RX_HDR_SIZE)
408 				hdr_len = eth_get_headlen(skb->dev,
409 							  aq_buf_vaddr(&buff->rxdata),
410 							  AQ_CFG_RX_HDR_SIZE);
411 
412 			memcpy(__skb_put(skb, hdr_len), aq_buf_vaddr(&buff->rxdata),
413 			       ALIGN(hdr_len, sizeof(long)));
414 
415 			if (buff->len - hdr_len > 0) {
416 				skb_add_rx_frag(skb, 0, buff->rxdata.page,
417 						buff->rxdata.pg_off + hdr_len,
418 						buff->len - hdr_len,
419 						AQ_CFG_RX_FRAME_MAX);
420 				page_ref_inc(buff->rxdata.page);
421 			}
422 
423 			if (!buff->is_eop) {
424 				buff_ = buff;
425 				i = 1U;
426 				do {
427 					next_ = buff_->next,
428 					buff_ = &self->buff_ring[next_];
429 
430 					dma_sync_single_range_for_cpu(
431 							aq_nic_get_dev(self->aq_nic),
432 							buff_->rxdata.daddr,
433 							buff_->rxdata.pg_off,
434 							buff_->len,
435 							DMA_FROM_DEVICE);
436 					skb_add_rx_frag(skb, i++,
437 							buff_->rxdata.page,
438 							buff_->rxdata.pg_off,
439 							buff_->len,
440 							AQ_CFG_RX_FRAME_MAX);
441 					page_ref_inc(buff_->rxdata.page);
442 					buff_->is_cleaned = 1;
443 
444 					buff->is_ip_cso &= buff_->is_ip_cso;
445 					buff->is_udp_cso &= buff_->is_udp_cso;
446 					buff->is_tcp_cso &= buff_->is_tcp_cso;
447 					buff->is_cso_err |= buff_->is_cso_err;
448 
449 				} while (!buff_->is_eop);
450 			}
451 		}
452 
453 		if (buff->is_vlan)
454 			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
455 					       buff->vlan_rx_tag);
456 
457 		skb->protocol = eth_type_trans(skb, ndev);
458 
459 		aq_rx_checksum(self, buff, skb);
460 
461 		skb_set_hash(skb, buff->rss_hash,
462 			     buff->is_hash_l4 ? PKT_HASH_TYPE_L4 :
463 			     PKT_HASH_TYPE_NONE);
464 		/* Send all PTP traffic to 0 queue */
465 		skb_record_rx_queue(skb, is_ptp_ring ? 0 : self->idx);
466 
467 		++self->stats.rx.packets;
468 		self->stats.rx.bytes += skb->len;
469 
470 		napi_gro_receive(napi, skb);
471 	}
472 
473 err_exit:
474 	return err;
475 }
476 
477 void aq_ring_hwts_rx_clean(struct aq_ring_s *self, struct aq_nic_s *aq_nic)
478 {
479 	while (self->sw_head != self->hw_head) {
480 		u64 ns;
481 
482 		aq_nic->aq_hw_ops->extract_hwts(aq_nic->aq_hw,
483 						self->dx_ring +
484 						(self->sw_head * self->dx_size),
485 						self->dx_size, &ns);
486 		aq_ptp_tx_hwtstamp(aq_nic, ns);
487 
488 		self->sw_head = aq_ring_next_dx(self, self->sw_head);
489 	}
490 }
491 
492 int aq_ring_rx_fill(struct aq_ring_s *self)
493 {
494 	unsigned int page_order = self->page_order;
495 	struct aq_ring_buff_s *buff = NULL;
496 	int err = 0;
497 	int i = 0;
498 
499 	if (aq_ring_avail_dx(self) < min_t(unsigned int, AQ_CFG_RX_REFILL_THRES,
500 					   self->size / 2))
501 		return err;
502 
503 	for (i = aq_ring_avail_dx(self); i--;
504 		self->sw_tail = aq_ring_next_dx(self, self->sw_tail)) {
505 		buff = &self->buff_ring[self->sw_tail];
506 
507 		buff->flags = 0U;
508 		buff->len = AQ_CFG_RX_FRAME_MAX;
509 
510 		err = aq_get_rxpages(self, buff, page_order);
511 		if (err)
512 			goto err_exit;
513 
514 		buff->pa = aq_buf_daddr(&buff->rxdata);
515 		buff = NULL;
516 	}
517 
518 err_exit:
519 	return err;
520 }
521 
522 void aq_ring_rx_deinit(struct aq_ring_s *self)
523 {
524 	if (!self)
525 		goto err_exit;
526 
527 	for (; self->sw_head != self->sw_tail;
528 		self->sw_head = aq_ring_next_dx(self, self->sw_head)) {
529 		struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
530 
531 		aq_free_rxpage(&buff->rxdata, aq_nic_get_dev(self->aq_nic));
532 	}
533 
534 err_exit:;
535 }
536 
537 void aq_ring_free(struct aq_ring_s *self)
538 {
539 	if (!self)
540 		goto err_exit;
541 
542 	kfree(self->buff_ring);
543 
544 	if (self->dx_ring)
545 		dma_free_coherent(aq_nic_get_dev(self->aq_nic),
546 				  self->size * self->dx_size, self->dx_ring,
547 				  self->dx_ring_pa);
548 
549 err_exit:;
550 }
551