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 
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 
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 
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 
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 
107 void aq_ring_tx_clean(struct aq_ring_s *self)
108 {
109 	struct device *dev = aq_nic_get_dev(self->aq_nic);
110 
111 	for (; self->sw_head != self->hw_head;
112 		self->sw_head = aq_ring_next_dx(self, self->sw_head)) {
113 		struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
114 
115 		if (likely(buff->is_mapped)) {
116 			if (unlikely(buff->is_sop))
117 				dma_unmap_single(dev, buff->pa, buff->len,
118 						 DMA_TO_DEVICE);
119 			else
120 				dma_unmap_page(dev, buff->pa, buff->len,
121 					       DMA_TO_DEVICE);
122 		}
123 
124 		if (unlikely(buff->is_eop))
125 			dev_kfree_skb_any(buff->skb);
126 	}
127 }
128 
129 static inline unsigned int aq_ring_dx_in_range(unsigned int h, unsigned int i,
130 					       unsigned int t)
131 {
132 	return (h < t) ? ((h < i) && (i < t)) : ((h < i) || (i < t));
133 }
134 
135 #define AQ_SKB_ALIGN SKB_DATA_ALIGN(sizeof(struct skb_shared_info))
136 int aq_ring_rx_clean(struct aq_ring_s *self, int *work_done, int budget)
137 {
138 	struct net_device *ndev = aq_nic_get_ndev(self->aq_nic);
139 	int err = 0;
140 	bool is_rsc_completed = true;
141 
142 	for (; (self->sw_head != self->hw_head) && budget;
143 		self->sw_head = aq_ring_next_dx(self, self->sw_head),
144 		--budget, ++(*work_done)) {
145 		struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
146 		struct sk_buff *skb = NULL;
147 		unsigned int next_ = 0U;
148 		unsigned int i = 0U;
149 		struct aq_ring_buff_s *buff_ = NULL;
150 
151 		if (buff->is_error) {
152 			__free_pages(buff->page, 0);
153 			continue;
154 		}
155 
156 		if (buff->is_cleaned)
157 			continue;
158 
159 		if (!buff->is_eop) {
160 			for (next_ = buff->next,
161 			     buff_ = &self->buff_ring[next_]; true;
162 			     next_ = buff_->next,
163 			     buff_ = &self->buff_ring[next_]) {
164 				is_rsc_completed =
165 					aq_ring_dx_in_range(self->sw_head,
166 							    next_,
167 							    self->hw_head);
168 
169 				if (unlikely(!is_rsc_completed)) {
170 					is_rsc_completed = false;
171 					break;
172 				}
173 
174 				if (buff_->is_eop)
175 					break;
176 			}
177 
178 			if (!is_rsc_completed) {
179 				err = 0;
180 				goto err_exit;
181 			}
182 		}
183 
184 		/* for single fragment packets use build_skb() */
185 		if (buff->is_eop) {
186 			skb = build_skb(page_address(buff->page),
187 					buff->len + AQ_SKB_ALIGN);
188 			if (unlikely(!skb)) {
189 				err = -ENOMEM;
190 				goto err_exit;
191 			}
192 
193 			skb_put(skb, buff->len);
194 		} else {
195 			skb = netdev_alloc_skb(ndev, ETH_HLEN);
196 			if (unlikely(!skb)) {
197 				err = -ENOMEM;
198 				goto err_exit;
199 			}
200 			skb_put(skb, ETH_HLEN);
201 			memcpy(skb->data, page_address(buff->page), ETH_HLEN);
202 
203 			skb_add_rx_frag(skb, 0, buff->page, ETH_HLEN,
204 					buff->len - ETH_HLEN,
205 					SKB_TRUESIZE(buff->len - ETH_HLEN));
206 
207 			for (i = 1U, next_ = buff->next,
208 			     buff_ = &self->buff_ring[next_]; true;
209 			     next_ = buff_->next,
210 			     buff_ = &self->buff_ring[next_], ++i) {
211 				skb_add_rx_frag(skb, i, buff_->page, 0,
212 						buff_->len,
213 						SKB_TRUESIZE(buff->len -
214 						ETH_HLEN));
215 				buff_->is_cleaned = 1;
216 
217 				if (buff_->is_eop)
218 					break;
219 			}
220 		}
221 
222 		skb->protocol = eth_type_trans(skb, ndev);
223 		if (unlikely(buff->is_cso_err)) {
224 			++self->stats.rx.errors;
225 			__skb_mark_checksum_bad(skb);
226 		} else {
227 			if (buff->is_ip_cso) {
228 				__skb_incr_checksum_unnecessary(skb);
229 				if (buff->is_udp_cso || buff->is_tcp_cso)
230 					__skb_incr_checksum_unnecessary(skb);
231 			} else {
232 				skb->ip_summed = CHECKSUM_NONE;
233 			}
234 		}
235 
236 		skb_set_hash(skb, buff->rss_hash,
237 			     buff->is_hash_l4 ? PKT_HASH_TYPE_L4 :
238 			     PKT_HASH_TYPE_NONE);
239 
240 		skb_record_rx_queue(skb, self->idx);
241 
242 		netif_receive_skb(skb);
243 
244 		++self->stats.rx.packets;
245 		self->stats.rx.bytes += skb->len;
246 	}
247 
248 err_exit:
249 	return err;
250 }
251 
252 int aq_ring_rx_fill(struct aq_ring_s *self)
253 {
254 	unsigned int pages_order = fls(AQ_CFG_RX_FRAME_MAX / PAGE_SIZE +
255 		(AQ_CFG_RX_FRAME_MAX % PAGE_SIZE ? 1 : 0)) - 1;
256 	struct aq_ring_buff_s *buff = NULL;
257 	int err = 0;
258 	int i = 0;
259 
260 	for (i = aq_ring_avail_dx(self); i--;
261 		self->sw_tail = aq_ring_next_dx(self, self->sw_tail)) {
262 		buff = &self->buff_ring[self->sw_tail];
263 
264 		buff->flags = 0U;
265 		buff->len = AQ_CFG_RX_FRAME_MAX;
266 
267 		buff->page = alloc_pages(GFP_ATOMIC | __GFP_COLD |
268 					 __GFP_COMP, pages_order);
269 		if (!buff->page) {
270 			err = -ENOMEM;
271 			goto err_exit;
272 		}
273 
274 		buff->pa = dma_map_page(aq_nic_get_dev(self->aq_nic),
275 					buff->page, 0,
276 					AQ_CFG_RX_FRAME_MAX, DMA_FROM_DEVICE);
277 
278 		if (dma_mapping_error(aq_nic_get_dev(self->aq_nic), buff->pa)) {
279 			err = -ENOMEM;
280 			goto err_exit;
281 		}
282 
283 		buff = NULL;
284 	}
285 
286 err_exit:
287 	if (err < 0) {
288 		if (buff && buff->page)
289 			__free_pages(buff->page, 0);
290 	}
291 
292 	return err;
293 }
294 
295 void aq_ring_rx_deinit(struct aq_ring_s *self)
296 {
297 	if (!self)
298 		goto err_exit;
299 
300 	for (; self->sw_head != self->sw_tail;
301 		self->sw_head = aq_ring_next_dx(self, self->sw_head)) {
302 		struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
303 
304 		dma_unmap_page(aq_nic_get_dev(self->aq_nic), buff->pa,
305 			       AQ_CFG_RX_FRAME_MAX, DMA_FROM_DEVICE);
306 
307 		__free_pages(buff->page, 0);
308 	}
309 
310 err_exit:;
311 }
312 
313 void aq_ring_free(struct aq_ring_s *self)
314 {
315 	if (!self)
316 		goto err_exit;
317 
318 	kfree(self->buff_ring);
319 
320 	if (self->dx_ring)
321 		dma_free_coherent(aq_nic_get_dev(self->aq_nic),
322 				  self->size * self->dx_size, self->dx_ring,
323 				  self->dx_ring_pa);
324 
325 err_exit:;
326 }
327