xref: /openbmc/linux/drivers/net/ethernet/aquantia/atlantic/aq_ring.c (revision 28efb0046512e8a13ed9f9bdf0d68d10bbfbe9cf)
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,
137 		     struct napi_struct *napi,
138 		     int *work_done,
139 		     int budget)
140 {
141 	struct net_device *ndev = aq_nic_get_ndev(self->aq_nic);
142 	int err = 0;
143 	bool is_rsc_completed = true;
144 
145 	for (; (self->sw_head != self->hw_head) && budget;
146 		self->sw_head = aq_ring_next_dx(self, self->sw_head),
147 		--budget, ++(*work_done)) {
148 		struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
149 		struct sk_buff *skb = NULL;
150 		unsigned int next_ = 0U;
151 		unsigned int i = 0U;
152 		struct aq_ring_buff_s *buff_ = NULL;
153 
154 		if (buff->is_error) {
155 			__free_pages(buff->page, 0);
156 			continue;
157 		}
158 
159 		if (buff->is_cleaned)
160 			continue;
161 
162 		if (!buff->is_eop) {
163 			for (next_ = buff->next,
164 			     buff_ = &self->buff_ring[next_]; true;
165 			     next_ = buff_->next,
166 			     buff_ = &self->buff_ring[next_]) {
167 				is_rsc_completed =
168 					aq_ring_dx_in_range(self->sw_head,
169 							    next_,
170 							    self->hw_head);
171 
172 				if (unlikely(!is_rsc_completed)) {
173 					is_rsc_completed = false;
174 					break;
175 				}
176 
177 				if (buff_->is_eop)
178 					break;
179 			}
180 
181 			if (!is_rsc_completed) {
182 				err = 0;
183 				goto err_exit;
184 			}
185 		}
186 
187 		/* for single fragment packets use build_skb() */
188 		if (buff->is_eop) {
189 			skb = build_skb(page_address(buff->page),
190 					buff->len + AQ_SKB_ALIGN);
191 			if (unlikely(!skb)) {
192 				err = -ENOMEM;
193 				goto err_exit;
194 			}
195 
196 			skb_put(skb, buff->len);
197 		} else {
198 			skb = netdev_alloc_skb(ndev, ETH_HLEN);
199 			if (unlikely(!skb)) {
200 				err = -ENOMEM;
201 				goto err_exit;
202 			}
203 			skb_put(skb, ETH_HLEN);
204 			memcpy(skb->data, page_address(buff->page), ETH_HLEN);
205 
206 			skb_add_rx_frag(skb, 0, buff->page, ETH_HLEN,
207 					buff->len - ETH_HLEN,
208 					SKB_TRUESIZE(buff->len - ETH_HLEN));
209 
210 			for (i = 1U, next_ = buff->next,
211 			     buff_ = &self->buff_ring[next_]; true;
212 			     next_ = buff_->next,
213 			     buff_ = &self->buff_ring[next_], ++i) {
214 				skb_add_rx_frag(skb, i, buff_->page, 0,
215 						buff_->len,
216 						SKB_TRUESIZE(buff->len -
217 						ETH_HLEN));
218 				buff_->is_cleaned = 1;
219 
220 				if (buff_->is_eop)
221 					break;
222 			}
223 		}
224 
225 		skb->protocol = eth_type_trans(skb, ndev);
226 		if (unlikely(buff->is_cso_err)) {
227 			++self->stats.rx.errors;
228 			skb->ip_summed = CHECKSUM_NONE;
229 		} else {
230 			if (buff->is_ip_cso) {
231 				__skb_incr_checksum_unnecessary(skb);
232 				if (buff->is_udp_cso || buff->is_tcp_cso)
233 					__skb_incr_checksum_unnecessary(skb);
234 			} else {
235 				skb->ip_summed = CHECKSUM_NONE;
236 			}
237 		}
238 
239 		skb_set_hash(skb, buff->rss_hash,
240 			     buff->is_hash_l4 ? PKT_HASH_TYPE_L4 :
241 			     PKT_HASH_TYPE_NONE);
242 
243 		skb_record_rx_queue(skb, self->idx);
244 
245 		napi_gro_receive(napi, skb);
246 
247 		++self->stats.rx.packets;
248 		self->stats.rx.bytes += skb->len;
249 	}
250 
251 err_exit:
252 	return err;
253 }
254 
255 int aq_ring_rx_fill(struct aq_ring_s *self)
256 {
257 	unsigned int pages_order = fls(AQ_CFG_RX_FRAME_MAX / PAGE_SIZE +
258 		(AQ_CFG_RX_FRAME_MAX % PAGE_SIZE ? 1 : 0)) - 1;
259 	struct aq_ring_buff_s *buff = NULL;
260 	int err = 0;
261 	int i = 0;
262 
263 	for (i = aq_ring_avail_dx(self); i--;
264 		self->sw_tail = aq_ring_next_dx(self, self->sw_tail)) {
265 		buff = &self->buff_ring[self->sw_tail];
266 
267 		buff->flags = 0U;
268 		buff->len = AQ_CFG_RX_FRAME_MAX;
269 
270 		buff->page = alloc_pages(GFP_ATOMIC | __GFP_COLD |
271 					 __GFP_COMP, pages_order);
272 		if (!buff->page) {
273 			err = -ENOMEM;
274 			goto err_exit;
275 		}
276 
277 		buff->pa = dma_map_page(aq_nic_get_dev(self->aq_nic),
278 					buff->page, 0,
279 					AQ_CFG_RX_FRAME_MAX, DMA_FROM_DEVICE);
280 
281 		if (dma_mapping_error(aq_nic_get_dev(self->aq_nic), buff->pa)) {
282 			err = -ENOMEM;
283 			goto err_exit;
284 		}
285 
286 		buff = NULL;
287 	}
288 
289 err_exit:
290 	if (err < 0) {
291 		if (buff && buff->page)
292 			__free_pages(buff->page, 0);
293 	}
294 
295 	return err;
296 }
297 
298 void aq_ring_rx_deinit(struct aq_ring_s *self)
299 {
300 	if (!self)
301 		goto err_exit;
302 
303 	for (; self->sw_head != self->sw_tail;
304 		self->sw_head = aq_ring_next_dx(self, self->sw_head)) {
305 		struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head];
306 
307 		dma_unmap_page(aq_nic_get_dev(self->aq_nic), buff->pa,
308 			       AQ_CFG_RX_FRAME_MAX, DMA_FROM_DEVICE);
309 
310 		__free_pages(buff->page, 0);
311 	}
312 
313 err_exit:;
314 }
315 
316 void aq_ring_free(struct aq_ring_s *self)
317 {
318 	if (!self)
319 		goto err_exit;
320 
321 	kfree(self->buff_ring);
322 
323 	if (self->dx_ring)
324 		dma_free_coherent(aq_nic_get_dev(self->aq_nic),
325 				  self->size * self->dx_size, self->dx_ring,
326 				  self->dx_ring_pa);
327 
328 err_exit:;
329 }
330