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 = AQ_CFG_TX_CLEAN_BUDGET;
143
144 for (; self->sw_head != self->hw_head && budget--;
145 self->sw_head = aq_ring_next_dx(self, self->sw_head)) {
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 dev_kfree_skb_any(buff->skb);
167
168 buff->pa = 0U;
169 buff->eop_index = 0xffffU;
170 }
171
172 return !!budget;
173 }
174
175 #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)176 int aq_ring_rx_clean(struct aq_ring_s *self,
177 struct napi_struct *napi,
178 int *work_done,
179 int budget)
180 {
181 struct net_device *ndev = aq_nic_get_ndev(self->aq_nic);
182 int err = 0;
183 bool is_rsc_completed = true;
184
185 for (; (self->sw_head != self->hw_head) && budget;
186 self->sw_head = aq_ring_next_dx(self, self->sw_head),
187 --budget, ++(*work_done)) {
188 struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
189 struct sk_buff *skb = NULL;
190 unsigned int next_ = 0U;
191 unsigned int i = 0U;
192 struct aq_ring_buff_s *buff_ = NULL;
193
194 if (buff->is_error) {
195 __free_pages(buff->page, 0);
196 continue;
197 }
198
199 if (buff->is_cleaned)
200 continue;
201
202 if (!buff->is_eop) {
203 for (next_ = buff->next,
204 buff_ = &self->buff_ring[next_]; true;
205 next_ = buff_->next,
206 buff_ = &self->buff_ring[next_]) {
207 is_rsc_completed =
208 aq_ring_dx_in_range(self->sw_head,
209 next_,
210 self->hw_head);
211
212 if (unlikely(!is_rsc_completed)) {
213 is_rsc_completed = false;
214 break;
215 }
216
217 if (buff_->is_eop)
218 break;
219 }
220
221 if (!is_rsc_completed) {
222 err = 0;
223 goto err_exit;
224 }
225 }
226
227 /* for single fragment packets use build_skb() */
228 if (buff->is_eop &&
229 buff->len <= AQ_CFG_RX_FRAME_MAX - AQ_SKB_ALIGN) {
230 skb = build_skb(page_address(buff->page),
231 AQ_CFG_RX_FRAME_MAX);
232 if (unlikely(!skb)) {
233 err = -ENOMEM;
234 goto err_exit;
235 }
236
237 skb_put(skb, buff->len);
238 } else {
239 skb = netdev_alloc_skb(ndev, ETH_HLEN);
240 if (unlikely(!skb)) {
241 err = -ENOMEM;
242 goto err_exit;
243 }
244 skb_put(skb, ETH_HLEN);
245 memcpy(skb->data, page_address(buff->page), ETH_HLEN);
246
247 skb_add_rx_frag(skb, 0, buff->page, ETH_HLEN,
248 buff->len - ETH_HLEN,
249 SKB_TRUESIZE(buff->len - ETH_HLEN));
250
251 if (!buff->is_eop) {
252 for (i = 1U, next_ = buff->next,
253 buff_ = &self->buff_ring[next_];
254 true; next_ = buff_->next,
255 buff_ = &self->buff_ring[next_], ++i) {
256 skb_add_rx_frag(skb, i,
257 buff_->page, 0,
258 buff_->len,
259 SKB_TRUESIZE(buff->len -
260 ETH_HLEN));
261 buff_->is_cleaned = 1;
262
263 if (buff_->is_eop)
264 break;
265 }
266 }
267 }
268
269 skb->protocol = eth_type_trans(skb, ndev);
270 if (unlikely(buff->is_cso_err)) {
271 ++self->stats.rx.errors;
272 skb->ip_summed = CHECKSUM_NONE;
273 } else {
274 if (buff->is_ip_cso) {
275 __skb_incr_checksum_unnecessary(skb);
276 if (buff->is_udp_cso || buff->is_tcp_cso)
277 __skb_incr_checksum_unnecessary(skb);
278 } else {
279 skb->ip_summed = CHECKSUM_NONE;
280 }
281 }
282
283 skb_set_hash(skb, buff->rss_hash,
284 buff->is_hash_l4 ? PKT_HASH_TYPE_L4 :
285 PKT_HASH_TYPE_NONE);
286
287 skb_record_rx_queue(skb, self->idx);
288
289 ++self->stats.rx.packets;
290 self->stats.rx.bytes += skb->len;
291
292 napi_gro_receive(napi, skb);
293 }
294
295 err_exit:
296 return err;
297 }
298
aq_ring_rx_fill(struct aq_ring_s * self)299 int aq_ring_rx_fill(struct aq_ring_s *self)
300 {
301 unsigned int pages_order = fls(AQ_CFG_RX_FRAME_MAX / PAGE_SIZE +
302 (AQ_CFG_RX_FRAME_MAX % PAGE_SIZE ? 1 : 0)) - 1;
303 struct aq_ring_buff_s *buff = NULL;
304 int err = 0;
305 int i = 0;
306
307 for (i = aq_ring_avail_dx(self); i--;
308 self->sw_tail = aq_ring_next_dx(self, self->sw_tail)) {
309 buff = &self->buff_ring[self->sw_tail];
310
311 buff->flags = 0U;
312 buff->len = AQ_CFG_RX_FRAME_MAX;
313
314 buff->page = alloc_pages(GFP_ATOMIC | __GFP_COMP, pages_order);
315 if (!buff->page) {
316 err = -ENOMEM;
317 goto err_exit;
318 }
319
320 buff->pa = dma_map_page(aq_nic_get_dev(self->aq_nic),
321 buff->page, 0,
322 AQ_CFG_RX_FRAME_MAX, DMA_FROM_DEVICE);
323
324 if (dma_mapping_error(aq_nic_get_dev(self->aq_nic), buff->pa)) {
325 err = -ENOMEM;
326 goto err_exit;
327 }
328
329 buff = NULL;
330 }
331
332 err_exit:
333 if (err < 0) {
334 if (buff && buff->page)
335 __free_pages(buff->page, 0);
336 }
337
338 return err;
339 }
340
aq_ring_rx_deinit(struct aq_ring_s * self)341 void aq_ring_rx_deinit(struct aq_ring_s *self)
342 {
343 if (!self)
344 goto err_exit;
345
346 for (; self->sw_head != self->sw_tail;
347 self->sw_head = aq_ring_next_dx(self, self->sw_head)) {
348 struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
349
350 dma_unmap_page(aq_nic_get_dev(self->aq_nic), buff->pa,
351 AQ_CFG_RX_FRAME_MAX, DMA_FROM_DEVICE);
352
353 __free_pages(buff->page, 0);
354 }
355
356 err_exit:;
357 }
358
aq_ring_free(struct aq_ring_s * self)359 void aq_ring_free(struct aq_ring_s *self)
360 {
361 if (!self)
362 goto err_exit;
363
364 kfree(self->buff_ring);
365
366 if (self->dx_ring)
367 dma_free_coherent(aq_nic_get_dev(self->aq_nic),
368 self->size * self->dx_size, self->dx_ring,
369 self->dx_ring_pa);
370
371 err_exit:;
372 }
373
