1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * aQuantia Corporation Network Driver
4 * Copyright (C) 2014-2017 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
14 #include <linux/netdevice.h>
15 #include <linux/etherdevice.h>
16
aq_free_rxpage(struct aq_rxpage * rxpage,struct device * dev)17 static inline void aq_free_rxpage(struct aq_rxpage *rxpage, struct device *dev)
18 {
19 unsigned int len = PAGE_SIZE << rxpage->order;
20
21 dma_unmap_page(dev, rxpage->daddr, len, DMA_FROM_DEVICE);
22
23 /* Drop the ref for being in the ring. */
24 __free_pages(rxpage->page, rxpage->order);
25 rxpage->page = NULL;
26 }
27
aq_get_rxpage(struct aq_rxpage * rxpage,unsigned int order,struct device * dev)28 static int aq_get_rxpage(struct aq_rxpage *rxpage, unsigned int order,
29 struct device *dev)
30 {
31 struct page *page;
32 dma_addr_t daddr;
33 int ret = -ENOMEM;
34
35 page = dev_alloc_pages(order);
36 if (unlikely(!page))
37 goto err_exit;
38
39 daddr = dma_map_page(dev, page, 0, PAGE_SIZE << order,
40 DMA_FROM_DEVICE);
41
42 if (unlikely(dma_mapping_error(dev, daddr)))
43 goto free_page;
44
45 rxpage->page = page;
46 rxpage->daddr = daddr;
47 rxpage->order = order;
48 rxpage->pg_off = 0;
49
50 return 0;
51
52 free_page:
53 __free_pages(page, order);
54
55 err_exit:
56 return ret;
57 }
58
aq_get_rxpages(struct aq_ring_s * self,struct aq_ring_buff_s * rxbuf,int order)59 static int aq_get_rxpages(struct aq_ring_s *self, struct aq_ring_buff_s *rxbuf,
60 int order)
61 {
62 int ret;
63
64 if (rxbuf->rxdata.page) {
65 /* One means ring is the only user and can reuse */
66 if (page_ref_count(rxbuf->rxdata.page) > 1) {
67 /* Try reuse buffer */
68 rxbuf->rxdata.pg_off += AQ_CFG_RX_FRAME_MAX;
69 if (rxbuf->rxdata.pg_off + AQ_CFG_RX_FRAME_MAX <=
70 (PAGE_SIZE << order)) {
71 self->stats.rx.pg_flips++;
72 } else {
73 /* Buffer exhausted. We have other users and
74 * should release this page and realloc
75 */
76 aq_free_rxpage(&rxbuf->rxdata,
77 aq_nic_get_dev(self->aq_nic));
78 self->stats.rx.pg_losts++;
79 }
80 } else {
81 rxbuf->rxdata.pg_off = 0;
82 self->stats.rx.pg_reuses++;
83 }
84 }
85
86 if (!rxbuf->rxdata.page) {
87 ret = aq_get_rxpage(&rxbuf->rxdata, order,
88 aq_nic_get_dev(self->aq_nic));
89 return ret;
90 }
91
92 return 0;
93 }
94
aq_ring_alloc(struct aq_ring_s * self,struct aq_nic_s * aq_nic)95 static struct aq_ring_s *aq_ring_alloc(struct aq_ring_s *self,
96 struct aq_nic_s *aq_nic)
97 {
98 int err = 0;
99
100 self->buff_ring =
101 kcalloc(self->size, sizeof(struct aq_ring_buff_s), GFP_KERNEL);
102
103 if (!self->buff_ring) {
104 err = -ENOMEM;
105 goto err_exit;
106 }
107 self->dx_ring = dma_alloc_coherent(aq_nic_get_dev(aq_nic),
108 self->size * self->dx_size,
109 &self->dx_ring_pa, GFP_KERNEL);
110 if (!self->dx_ring) {
111 err = -ENOMEM;
112 goto err_exit;
113 }
114
115 err_exit:
116 if (err < 0) {
117 aq_ring_free(self);
118 self = NULL;
119 }
120 return self;
121 }
122
aq_ring_tx_alloc(struct aq_ring_s * self,struct aq_nic_s * aq_nic,unsigned int idx,struct aq_nic_cfg_s * aq_nic_cfg)123 struct aq_ring_s *aq_ring_tx_alloc(struct aq_ring_s *self,
124 struct aq_nic_s *aq_nic,
125 unsigned int idx,
126 struct aq_nic_cfg_s *aq_nic_cfg)
127 {
128 int err = 0;
129
130 self->aq_nic = aq_nic;
131 self->idx = idx;
132 self->size = aq_nic_cfg->txds;
133 self->dx_size = aq_nic_cfg->aq_hw_caps->txd_size;
134
135 self = aq_ring_alloc(self, aq_nic);
136 if (!self) {
137 err = -ENOMEM;
138 goto err_exit;
139 }
140
141 err_exit:
142 if (err < 0) {
143 aq_ring_free(self);
144 self = NULL;
145 }
146 return self;
147 }
148
aq_ring_rx_alloc(struct aq_ring_s * self,struct aq_nic_s * aq_nic,unsigned int idx,struct aq_nic_cfg_s * aq_nic_cfg)149 struct aq_ring_s *aq_ring_rx_alloc(struct aq_ring_s *self,
150 struct aq_nic_s *aq_nic,
151 unsigned int idx,
152 struct aq_nic_cfg_s *aq_nic_cfg)
153 {
154 int err = 0;
155
156 self->aq_nic = aq_nic;
157 self->idx = idx;
158 self->size = aq_nic_cfg->rxds;
159 self->dx_size = aq_nic_cfg->aq_hw_caps->rxd_size;
160 self->page_order = fls(AQ_CFG_RX_FRAME_MAX / PAGE_SIZE +
161 (AQ_CFG_RX_FRAME_MAX % PAGE_SIZE ? 1 : 0)) - 1;
162
163 if (aq_nic_cfg->rxpageorder > self->page_order)
164 self->page_order = aq_nic_cfg->rxpageorder;
165
166 self = aq_ring_alloc(self, aq_nic);
167 if (!self) {
168 err = -ENOMEM;
169 goto err_exit;
170 }
171
172 err_exit:
173 if (err < 0) {
174 aq_ring_free(self);
175 self = NULL;
176 }
177 return self;
178 }
179
aq_ring_init(struct aq_ring_s * self)180 int aq_ring_init(struct aq_ring_s *self)
181 {
182 self->hw_head = 0;
183 self->sw_head = 0;
184 self->sw_tail = 0;
185 return 0;
186 }
187
aq_ring_dx_in_range(unsigned int h,unsigned int i,unsigned int t)188 static inline bool aq_ring_dx_in_range(unsigned int h, unsigned int i,
189 unsigned int t)
190 {
191 return (h < t) ? ((h < i) && (i < t)) : ((h < i) || (i < t));
192 }
193
aq_ring_update_queue_state(struct aq_ring_s * ring)194 void aq_ring_update_queue_state(struct aq_ring_s *ring)
195 {
196 if (aq_ring_avail_dx(ring) <= AQ_CFG_SKB_FRAGS_MAX)
197 aq_ring_queue_stop(ring);
198 else if (aq_ring_avail_dx(ring) > AQ_CFG_RESTART_DESC_THRES)
199 aq_ring_queue_wake(ring);
200 }
201
aq_ring_queue_wake(struct aq_ring_s * ring)202 void aq_ring_queue_wake(struct aq_ring_s *ring)
203 {
204 struct net_device *ndev = aq_nic_get_ndev(ring->aq_nic);
205
206 if (__netif_subqueue_stopped(ndev, ring->idx)) {
207 netif_wake_subqueue(ndev, ring->idx);
208 ring->stats.tx.queue_restarts++;
209 }
210 }
211
aq_ring_queue_stop(struct aq_ring_s * ring)212 void aq_ring_queue_stop(struct aq_ring_s *ring)
213 {
214 struct net_device *ndev = aq_nic_get_ndev(ring->aq_nic);
215
216 if (!__netif_subqueue_stopped(ndev, ring->idx))
217 netif_stop_subqueue(ndev, ring->idx);
218 }
219
aq_ring_tx_clean(struct aq_ring_s * self)220 bool aq_ring_tx_clean(struct aq_ring_s *self)
221 {
222 struct device *dev = aq_nic_get_dev(self->aq_nic);
223 unsigned int budget;
224
225 for (budget = AQ_CFG_TX_CLEAN_BUDGET;
226 budget && self->sw_head != self->hw_head; budget--) {
227 struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
228
229 if (likely(buff->is_mapped)) {
230 if (unlikely(buff->is_sop)) {
231 if (!buff->is_eop &&
232 buff->eop_index != 0xffffU &&
233 (!aq_ring_dx_in_range(self->sw_head,
234 buff->eop_index,
235 self->hw_head)))
236 break;
237
238 dma_unmap_single(dev, buff->pa, buff->len,
239 DMA_TO_DEVICE);
240 } else {
241 dma_unmap_page(dev, buff->pa, buff->len,
242 DMA_TO_DEVICE);
243 }
244 }
245
246 if (unlikely(buff->is_eop))
247 dev_kfree_skb_any(buff->skb);
248
249 buff->pa = 0U;
250 buff->eop_index = 0xffffU;
251 self->sw_head = aq_ring_next_dx(self, self->sw_head);
252 }
253
254 return !!budget;
255 }
256
aq_rx_checksum(struct aq_ring_s * self,struct aq_ring_buff_s * buff,struct sk_buff * skb)257 static void aq_rx_checksum(struct aq_ring_s *self,
258 struct aq_ring_buff_s *buff,
259 struct sk_buff *skb)
260 {
261 if (!(self->aq_nic->ndev->features & NETIF_F_RXCSUM))
262 return;
263
264 if (unlikely(buff->is_cso_err)) {
265 ++self->stats.rx.errors;
266 skb->ip_summed = CHECKSUM_NONE;
267 return;
268 }
269 if (buff->is_ip_cso) {
270 __skb_incr_checksum_unnecessary(skb);
271 } else {
272 skb->ip_summed = CHECKSUM_NONE;
273 }
274
275 if (buff->is_udp_cso || buff->is_tcp_cso)
276 __skb_incr_checksum_unnecessary(skb);
277 }
278
279 #define AQ_SKB_ALIGN SKB_DATA_ALIGN(sizeof(struct skb_shared_info))
aq_ring_rx_clean(struct aq_ring_s * self,struct napi_struct * napi,int * work_done,int budget)280 int aq_ring_rx_clean(struct aq_ring_s *self,
281 struct napi_struct *napi,
282 int *work_done,
283 int budget)
284 {
285 struct net_device *ndev = aq_nic_get_ndev(self->aq_nic);
286 bool is_rsc_completed = true;
287 int err = 0;
288
289 for (; (self->sw_head != self->hw_head) && budget;
290 self->sw_head = aq_ring_next_dx(self, self->sw_head),
291 --budget, ++(*work_done)) {
292 struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
293 struct aq_ring_buff_s *buff_ = NULL;
294 struct sk_buff *skb = NULL;
295 unsigned int next_ = 0U;
296 unsigned int i = 0U;
297 u16 hdr_len;
298
299 if (buff->is_cleaned)
300 continue;
301
302 if (!buff->is_eop) {
303 buff_ = buff;
304 do {
305 next_ = buff_->next,
306 buff_ = &self->buff_ring[next_];
307 is_rsc_completed =
308 aq_ring_dx_in_range(self->sw_head,
309 next_,
310 self->hw_head);
311
312 if (unlikely(!is_rsc_completed))
313 break;
314
315 buff->is_error |= buff_->is_error;
316 buff->is_cso_err |= buff_->is_cso_err;
317
318 } while (!buff_->is_eop);
319
320 if (!is_rsc_completed) {
321 err = 0;
322 goto err_exit;
323 }
324 if (buff->is_error || buff->is_cso_err) {
325 buff_ = buff;
326 do {
327 next_ = buff_->next,
328 buff_ = &self->buff_ring[next_];
329
330 buff_->is_cleaned = true;
331 } while (!buff_->is_eop);
332
333 ++self->stats.rx.errors;
334 continue;
335 }
336 }
337
338 if (buff->is_error) {
339 ++self->stats.rx.errors;
340 continue;
341 }
342
343 dma_sync_single_range_for_cpu(aq_nic_get_dev(self->aq_nic),
344 buff->rxdata.daddr,
345 buff->rxdata.pg_off,
346 buff->len, DMA_FROM_DEVICE);
347
348 /* for single fragment packets use build_skb() */
349 if (buff->is_eop &&
350 buff->len <= AQ_CFG_RX_FRAME_MAX - AQ_SKB_ALIGN) {
351 skb = build_skb(aq_buf_vaddr(&buff->rxdata),
352 AQ_CFG_RX_FRAME_MAX);
353 if (unlikely(!skb)) {
354 err = -ENOMEM;
355 goto err_exit;
356 }
357 skb_put(skb, buff->len);
358 page_ref_inc(buff->rxdata.page);
359 } else {
360 skb = napi_alloc_skb(napi, AQ_CFG_RX_HDR_SIZE);
361 if (unlikely(!skb)) {
362 err = -ENOMEM;
363 goto err_exit;
364 }
365
366 hdr_len = buff->len;
367 if (hdr_len > AQ_CFG_RX_HDR_SIZE)
368 hdr_len = eth_get_headlen(skb->dev,
369 aq_buf_vaddr(&buff->rxdata),
370 AQ_CFG_RX_HDR_SIZE);
371
372 memcpy(__skb_put(skb, hdr_len), aq_buf_vaddr(&buff->rxdata),
373 ALIGN(hdr_len, sizeof(long)));
374
375 if (buff->len - hdr_len > 0) {
376 skb_add_rx_frag(skb, 0, buff->rxdata.page,
377 buff->rxdata.pg_off + hdr_len,
378 buff->len - hdr_len,
379 AQ_CFG_RX_FRAME_MAX);
380 page_ref_inc(buff->rxdata.page);
381 }
382
383 if (!buff->is_eop) {
384 buff_ = buff;
385 i = 1U;
386 do {
387 next_ = buff_->next,
388 buff_ = &self->buff_ring[next_];
389
390 dma_sync_single_range_for_cpu(
391 aq_nic_get_dev(self->aq_nic),
392 buff_->rxdata.daddr,
393 buff_->rxdata.pg_off,
394 buff_->len,
395 DMA_FROM_DEVICE);
396 skb_add_rx_frag(skb, i++,
397 buff_->rxdata.page,
398 buff_->rxdata.pg_off,
399 buff_->len,
400 AQ_CFG_RX_FRAME_MAX);
401 page_ref_inc(buff_->rxdata.page);
402 buff_->is_cleaned = 1;
403
404 buff->is_ip_cso &= buff_->is_ip_cso;
405 buff->is_udp_cso &= buff_->is_udp_cso;
406 buff->is_tcp_cso &= buff_->is_tcp_cso;
407 buff->is_cso_err |= buff_->is_cso_err;
408
409 } while (!buff_->is_eop);
410 }
411 }
412
413 if (buff->is_vlan)
414 __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
415 buff->vlan_rx_tag);
416
417 skb->protocol = eth_type_trans(skb, ndev);
418
419 aq_rx_checksum(self, buff, skb);
420
421 skb_set_hash(skb, buff->rss_hash,
422 buff->is_hash_l4 ? PKT_HASH_TYPE_L4 :
423 PKT_HASH_TYPE_NONE);
424
425 skb_record_rx_queue(skb, self->idx);
426
427 ++self->stats.rx.packets;
428 self->stats.rx.bytes += skb->len;
429
430 napi_gro_receive(napi, skb);
431 }
432
433 err_exit:
434 return err;
435 }
436
aq_ring_rx_fill(struct aq_ring_s * self)437 int aq_ring_rx_fill(struct aq_ring_s *self)
438 {
439 unsigned int page_order = self->page_order;
440 struct aq_ring_buff_s *buff = NULL;
441 int err = 0;
442 int i = 0;
443
444 if (aq_ring_avail_dx(self) < min_t(unsigned int, AQ_CFG_RX_REFILL_THRES,
445 self->size / 2))
446 return err;
447
448 for (i = aq_ring_avail_dx(self); i--;
449 self->sw_tail = aq_ring_next_dx(self, self->sw_tail)) {
450 buff = &self->buff_ring[self->sw_tail];
451
452 buff->flags = 0U;
453 buff->len = AQ_CFG_RX_FRAME_MAX;
454
455 err = aq_get_rxpages(self, buff, page_order);
456 if (err)
457 goto err_exit;
458
459 buff->pa = aq_buf_daddr(&buff->rxdata);
460 buff = NULL;
461 }
462
463 err_exit:
464 return err;
465 }
466
aq_ring_rx_deinit(struct aq_ring_s * self)467 void aq_ring_rx_deinit(struct aq_ring_s *self)
468 {
469 if (!self)
470 goto err_exit;
471
472 for (; self->sw_head != self->sw_tail;
473 self->sw_head = aq_ring_next_dx(self, self->sw_head)) {
474 struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
475
476 aq_free_rxpage(&buff->rxdata, aq_nic_get_dev(self->aq_nic));
477 }
478
479 err_exit:;
480 }
481
aq_ring_free(struct aq_ring_s * self)482 void aq_ring_free(struct aq_ring_s *self)
483 {
484 if (!self)
485 goto err_exit;
486
487 kfree(self->buff_ring);
488
489 if (self->dx_ring)
490 dma_free_coherent(aq_nic_get_dev(self->aq_nic),
491 self->size * self->dx_size, self->dx_ring,
492 self->dx_ring_pa);
493
494 err_exit:;
495 }
496
