1 /*
2 * aQuantia Corporation Network Driver
3 * Copyright (C) 2014-2017 aQuantia Corporation. All rights reserved
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms and conditions of the GNU General Public License,
7 * version 2, as published by the Free Software Foundation.
8 */
9
10 /* File aq_ring.c: Definition of functions for Rx/Tx rings. */
11
12 #include "aq_ring.h"
13 #include "aq_nic.h"
14 #include "aq_hw.h"
15
16 #include <linux/netdevice.h>
17 #include <linux/etherdevice.h>
18
aq_ring_alloc(struct aq_ring_s * self,struct aq_nic_s * aq_nic)19 static struct aq_ring_s *aq_ring_alloc(struct aq_ring_s *self,
20 struct aq_nic_s *aq_nic)
21 {
22 int err = 0;
23
24 self->buff_ring =
25 kcalloc(self->size, sizeof(struct aq_ring_buff_s), GFP_KERNEL);
26
27 if (!self->buff_ring) {
28 err = -ENOMEM;
29 goto err_exit;
30 }
31 self->dx_ring = dma_alloc_coherent(aq_nic_get_dev(aq_nic),
32 self->size * self->dx_size,
33 &self->dx_ring_pa, GFP_KERNEL);
34 if (!self->dx_ring) {
35 err = -ENOMEM;
36 goto err_exit;
37 }
38
39 err_exit:
40 if (err < 0) {
41 aq_ring_free(self);
42 self = NULL;
43 }
44 return self;
45 }
46
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)47 struct aq_ring_s *aq_ring_tx_alloc(struct aq_ring_s *self,
48 struct aq_nic_s *aq_nic,
49 unsigned int idx,
50 struct aq_nic_cfg_s *aq_nic_cfg)
51 {
52 int err = 0;
53
54 self->aq_nic = aq_nic;
55 self->idx = idx;
56 self->size = aq_nic_cfg->txds;
57 self->dx_size = aq_nic_cfg->aq_hw_caps->txd_size;
58
59 self = aq_ring_alloc(self, aq_nic);
60 if (!self) {
61 err = -ENOMEM;
62 goto err_exit;
63 }
64
65 err_exit:
66 if (err < 0) {
67 aq_ring_free(self);
68 self = NULL;
69 }
70 return self;
71 }
72
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)73 struct aq_ring_s *aq_ring_rx_alloc(struct aq_ring_s *self,
74 struct aq_nic_s *aq_nic,
75 unsigned int idx,
76 struct aq_nic_cfg_s *aq_nic_cfg)
77 {
78 int err = 0;
79
80 self->aq_nic = aq_nic;
81 self->idx = idx;
82 self->size = aq_nic_cfg->rxds;
83 self->dx_size = aq_nic_cfg->aq_hw_caps->rxd_size;
84
85 self = aq_ring_alloc(self, aq_nic);
86 if (!self) {
87 err = -ENOMEM;
88 goto err_exit;
89 }
90
91 err_exit:
92 if (err < 0) {
93 aq_ring_free(self);
94 self = NULL;
95 }
96 return self;
97 }
98
aq_ring_init(struct aq_ring_s * self)99 int aq_ring_init(struct aq_ring_s *self)
100 {
101 self->hw_head = 0;
102 self->sw_head = 0;
103 self->sw_tail = 0;
104 return 0;
105 }
106
aq_ring_dx_in_range(unsigned int h,unsigned int i,unsigned int t)107 static inline bool aq_ring_dx_in_range(unsigned int h, unsigned int i,
108 unsigned int t)
109 {
110 return (h < t) ? ((h < i) && (i < t)) : ((h < i) || (i < t));
111 }
112
aq_ring_update_queue_state(struct aq_ring_s * ring)113 void aq_ring_update_queue_state(struct aq_ring_s *ring)
114 {
115 if (aq_ring_avail_dx(ring) <= AQ_CFG_SKB_FRAGS_MAX)
116 aq_ring_queue_stop(ring);
117 else if (aq_ring_avail_dx(ring) > AQ_CFG_RESTART_DESC_THRES)
118 aq_ring_queue_wake(ring);
119 }
120
aq_ring_queue_wake(struct aq_ring_s * ring)121 void aq_ring_queue_wake(struct aq_ring_s *ring)
122 {
123 struct net_device *ndev = aq_nic_get_ndev(ring->aq_nic);
124
125 if (__netif_subqueue_stopped(ndev, ring->idx)) {
126 netif_wake_subqueue(ndev, ring->idx);
127 ring->stats.tx.queue_restarts++;
128 }
129 }
130
aq_ring_queue_stop(struct aq_ring_s * ring)131 void aq_ring_queue_stop(struct aq_ring_s *ring)
132 {
133 struct net_device *ndev = aq_nic_get_ndev(ring->aq_nic);
134
135 if (!__netif_subqueue_stopped(ndev, ring->idx))
136 netif_stop_subqueue(ndev, ring->idx);
137 }
138
aq_ring_tx_clean(struct aq_ring_s * self)139 bool aq_ring_tx_clean(struct aq_ring_s *self)
140 {
141 struct device *dev = aq_nic_get_dev(self->aq_nic);
142 unsigned int budget;
143
144 for (budget = AQ_CFG_TX_CLEAN_BUDGET;
145 budget && self->sw_head != self->hw_head; budget--) {
146 struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
147
148 if (likely(buff->is_mapped)) {
149 if (unlikely(buff->is_sop)) {
150 if (!buff->is_eop &&
151 buff->eop_index != 0xffffU &&
152 (!aq_ring_dx_in_range(self->sw_head,
153 buff->eop_index,
154 self->hw_head)))
155 break;
156
157 dma_unmap_single(dev, buff->pa, buff->len,
158 DMA_TO_DEVICE);
159 } else {
160 dma_unmap_page(dev, buff->pa, buff->len,
161 DMA_TO_DEVICE);
162 }
163 }
164
165 if (unlikely(buff->is_eop)) {
166 ++self->stats.rx.packets;
167 self->stats.tx.bytes += buff->skb->len;
168
169 dev_kfree_skb_any(buff->skb);
170 }
171 buff->pa = 0U;
172 buff->eop_index = 0xffffU;
173 self->sw_head = aq_ring_next_dx(self, self->sw_head);
174 }
175
176 return !!budget;
177 }
178
aq_rx_checksum(struct aq_ring_s * self,struct aq_ring_buff_s * buff,struct sk_buff * skb)179 static void aq_rx_checksum(struct aq_ring_s *self,
180 struct aq_ring_buff_s *buff,
181 struct sk_buff *skb)
182 {
183 if (!(self->aq_nic->ndev->features & NETIF_F_RXCSUM))
184 return;
185
186 if (unlikely(buff->is_cso_err)) {
187 ++self->stats.rx.errors;
188 skb->ip_summed = CHECKSUM_NONE;
189 return;
190 }
191 if (buff->is_ip_cso) {
192 __skb_incr_checksum_unnecessary(skb);
193 } else {
194 skb->ip_summed = CHECKSUM_NONE;
195 }
196
197 if (buff->is_udp_cso || buff->is_tcp_cso)
198 __skb_incr_checksum_unnecessary(skb);
199 }
200
201 #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)202 int aq_ring_rx_clean(struct aq_ring_s *self,
203 struct napi_struct *napi,
204 int *work_done,
205 int budget)
206 {
207 struct net_device *ndev = aq_nic_get_ndev(self->aq_nic);
208 int err = 0;
209 bool is_rsc_completed = true;
210
211 for (; (self->sw_head != self->hw_head) && budget;
212 self->sw_head = aq_ring_next_dx(self, self->sw_head),
213 --budget, ++(*work_done)) {
214 struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
215 struct sk_buff *skb = NULL;
216 unsigned int next_ = 0U;
217 unsigned int i = 0U;
218 struct aq_ring_buff_s *buff_ = NULL;
219
220 if (buff->is_error) {
221 __free_pages(buff->page, 0);
222 continue;
223 }
224
225 if (buff->is_cleaned)
226 continue;
227
228 if (!buff->is_eop) {
229 for (next_ = buff->next,
230 buff_ = &self->buff_ring[next_]; true;
231 next_ = buff_->next,
232 buff_ = &self->buff_ring[next_]) {
233 is_rsc_completed =
234 aq_ring_dx_in_range(self->sw_head,
235 next_,
236 self->hw_head);
237
238 if (unlikely(!is_rsc_completed)) {
239 is_rsc_completed = false;
240 break;
241 }
242
243 if (buff_->is_eop)
244 break;
245 }
246
247 if (!is_rsc_completed) {
248 err = 0;
249 goto err_exit;
250 }
251 }
252
253 /* for single fragment packets use build_skb() */
254 if (buff->is_eop &&
255 buff->len <= AQ_CFG_RX_FRAME_MAX - AQ_SKB_ALIGN) {
256 skb = build_skb(page_address(buff->page),
257 AQ_CFG_RX_FRAME_MAX);
258 if (unlikely(!skb)) {
259 err = -ENOMEM;
260 goto err_exit;
261 }
262
263 skb_put(skb, buff->len);
264 } else {
265 skb = netdev_alloc_skb(ndev, ETH_HLEN);
266 if (unlikely(!skb)) {
267 err = -ENOMEM;
268 goto err_exit;
269 }
270 skb_put(skb, ETH_HLEN);
271 memcpy(skb->data, page_address(buff->page), ETH_HLEN);
272
273 skb_add_rx_frag(skb, 0, buff->page, ETH_HLEN,
274 buff->len - ETH_HLEN,
275 SKB_TRUESIZE(buff->len - ETH_HLEN));
276
277 if (!buff->is_eop) {
278 for (i = 1U, next_ = buff->next,
279 buff_ = &self->buff_ring[next_];
280 true; next_ = buff_->next,
281 buff_ = &self->buff_ring[next_], ++i) {
282 skb_add_rx_frag(skb, i,
283 buff_->page, 0,
284 buff_->len,
285 SKB_TRUESIZE(buff->len -
286 ETH_HLEN));
287 buff_->is_cleaned = 1;
288
289 if (buff_->is_eop)
290 break;
291 }
292 }
293 }
294
295 skb->protocol = eth_type_trans(skb, ndev);
296
297 aq_rx_checksum(self, buff, skb);
298
299 skb_set_hash(skb, buff->rss_hash,
300 buff->is_hash_l4 ? PKT_HASH_TYPE_L4 :
301 PKT_HASH_TYPE_NONE);
302
303 skb_record_rx_queue(skb, self->idx);
304
305 ++self->stats.rx.packets;
306 self->stats.rx.bytes += skb->len;
307
308 napi_gro_receive(napi, skb);
309 }
310
311 err_exit:
312 return err;
313 }
314
aq_ring_rx_fill(struct aq_ring_s * self)315 int aq_ring_rx_fill(struct aq_ring_s *self)
316 {
317 unsigned int pages_order = fls(AQ_CFG_RX_FRAME_MAX / PAGE_SIZE +
318 (AQ_CFG_RX_FRAME_MAX % PAGE_SIZE ? 1 : 0)) - 1;
319 struct aq_ring_buff_s *buff = NULL;
320 int err = 0;
321 int i = 0;
322
323 for (i = aq_ring_avail_dx(self); i--;
324 self->sw_tail = aq_ring_next_dx(self, self->sw_tail)) {
325 buff = &self->buff_ring[self->sw_tail];
326
327 buff->flags = 0U;
328 buff->len = AQ_CFG_RX_FRAME_MAX;
329
330 buff->page = alloc_pages(GFP_ATOMIC | __GFP_COMP, pages_order);
331 if (!buff->page) {
332 err = -ENOMEM;
333 goto err_exit;
334 }
335
336 buff->pa = dma_map_page(aq_nic_get_dev(self->aq_nic),
337 buff->page, 0,
338 AQ_CFG_RX_FRAME_MAX, DMA_FROM_DEVICE);
339
340 if (dma_mapping_error(aq_nic_get_dev(self->aq_nic), buff->pa)) {
341 err = -ENOMEM;
342 goto err_exit;
343 }
344
345 buff = NULL;
346 }
347
348 err_exit:
349 if (err < 0) {
350 if (buff && buff->page)
351 __free_pages(buff->page, 0);
352 }
353
354 return err;
355 }
356
aq_ring_rx_deinit(struct aq_ring_s * self)357 void aq_ring_rx_deinit(struct aq_ring_s *self)
358 {
359 if (!self)
360 goto err_exit;
361
362 for (; self->sw_head != self->sw_tail;
363 self->sw_head = aq_ring_next_dx(self, self->sw_head)) {
364 struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
365
366 dma_unmap_page(aq_nic_get_dev(self->aq_nic), buff->pa,
367 AQ_CFG_RX_FRAME_MAX, DMA_FROM_DEVICE);
368
369 __free_pages(buff->page, 0);
370 }
371
372 err_exit:;
373 }
374
aq_ring_free(struct aq_ring_s * self)375 void aq_ring_free(struct aq_ring_s *self)
376 {
377 if (!self)
378 goto err_exit;
379
380 kfree(self->buff_ring);
381
382 if (self->dx_ring)
383 dma_free_coherent(aq_nic_get_dev(self->aq_nic),
384 self->size * self->dx_size, self->dx_ring,
385 self->dx_ring_pa);
386
387 err_exit:;
388 }
389