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7#include <linux/can/dev.h>
8#include <linux/can/rx-offload.h>
9
10struct can_rx_offload_cb {
11 u32 timestamp;
12};
13
14static inline struct can_rx_offload_cb *can_rx_offload_get_cb(struct sk_buff *skb)
15{
16 BUILD_BUG_ON(sizeof(struct can_rx_offload_cb) > sizeof(skb->cb));
17
18 return (struct can_rx_offload_cb *)skb->cb;
19}
20
21static inline bool can_rx_offload_le(struct can_rx_offload *offload, unsigned int a, unsigned int b)
22{
23 if (offload->inc)
24 return a <= b;
25 else
26 return a >= b;
27}
28
29static inline unsigned int can_rx_offload_inc(struct can_rx_offload *offload, unsigned int *val)
30{
31 if (offload->inc)
32 return (*val)++;
33 else
34 return (*val)--;
35}
36
37static int can_rx_offload_napi_poll(struct napi_struct *napi, int quota)
38{
39 struct can_rx_offload *offload = container_of(napi, struct can_rx_offload, napi);
40 struct net_device *dev = offload->dev;
41 struct net_device_stats *stats = &dev->stats;
42 struct sk_buff *skb;
43 int work_done = 0;
44
45 while ((work_done < quota) &&
46 (skb = skb_dequeue(&offload->skb_queue))) {
47 struct can_frame *cf = (struct can_frame *)skb->data;
48
49 work_done++;
50 stats->rx_packets++;
51 stats->rx_bytes += cf->can_dlc;
52 netif_receive_skb(skb);
53 }
54
55 if (work_done < quota) {
56 napi_complete_done(napi, work_done);
57
58
59 if (!skb_queue_empty(&offload->skb_queue))
60 napi_reschedule(&offload->napi);
61 }
62
63 can_led_event(offload->dev, CAN_LED_EVENT_RX);
64
65 return work_done;
66}
67
68static inline void __skb_queue_add_sort(struct sk_buff_head *head, struct sk_buff *new,
69 int (*compare)(struct sk_buff *a, struct sk_buff *b))
70{
71 struct sk_buff *pos, *insert = NULL;
72
73 skb_queue_reverse_walk(head, pos) {
74 const struct can_rx_offload_cb *cb_pos, *cb_new;
75
76 cb_pos = can_rx_offload_get_cb(pos);
77 cb_new = can_rx_offload_get_cb(new);
78
79 netdev_dbg(new->dev,
80 "%s: pos=0x%08x, new=0x%08x, diff=%10d, queue_len=%d\n",
81 __func__,
82 cb_pos->timestamp, cb_new->timestamp,
83 cb_new->timestamp - cb_pos->timestamp,
84 skb_queue_len(head));
85
86 if (compare(pos, new) < 0)
87 continue;
88 insert = pos;
89 break;
90 }
91 if (!insert)
92 __skb_queue_head(head, new);
93 else
94 __skb_queue_after(head, insert, new);
95}
96
97static int can_rx_offload_compare(struct sk_buff *a, struct sk_buff *b)
98{
99 const struct can_rx_offload_cb *cb_a, *cb_b;
100
101 cb_a = can_rx_offload_get_cb(a);
102 cb_b = can_rx_offload_get_cb(b);
103
104
105
106
107 return cb_b->timestamp - cb_a->timestamp;
108}
109
110static struct sk_buff *can_rx_offload_offload_one(struct can_rx_offload *offload, unsigned int n)
111{
112 struct sk_buff *skb = NULL;
113 struct can_rx_offload_cb *cb;
114 struct can_frame *cf;
115 int ret;
116
117
118 if (likely(skb_queue_len(&offload->skb_queue) <=
119 offload->skb_queue_len_max))
120 skb = alloc_can_skb(offload->dev, &cf);
121
122 if (!skb) {
123 struct can_frame cf_overflow;
124 u32 timestamp;
125
126 ret = offload->mailbox_read(offload, &cf_overflow,
127 ×tamp, n);
128 if (ret)
129 offload->dev->stats.rx_dropped++;
130
131 return NULL;
132 }
133
134 cb = can_rx_offload_get_cb(skb);
135 ret = offload->mailbox_read(offload, cf, &cb->timestamp, n);
136 if (!ret) {
137 kfree_skb(skb);
138 return NULL;
139 }
140
141 return skb;
142}
143
144int can_rx_offload_irq_offload_timestamp(struct can_rx_offload *offload, u64 pending)
145{
146 struct sk_buff_head skb_queue;
147 unsigned int i;
148
149 __skb_queue_head_init(&skb_queue);
150
151 for (i = offload->mb_first;
152 can_rx_offload_le(offload, i, offload->mb_last);
153 can_rx_offload_inc(offload, &i)) {
154 struct sk_buff *skb;
155
156 if (!(pending & BIT_ULL(i)))
157 continue;
158
159 skb = can_rx_offload_offload_one(offload, i);
160 if (!skb)
161 break;
162
163 __skb_queue_add_sort(&skb_queue, skb, can_rx_offload_compare);
164 }
165
166 if (!skb_queue_empty(&skb_queue)) {
167 unsigned long flags;
168 u32 queue_len;
169
170 spin_lock_irqsave(&offload->skb_queue.lock, flags);
171 skb_queue_splice_tail(&skb_queue, &offload->skb_queue);
172 spin_unlock_irqrestore(&offload->skb_queue.lock, flags);
173
174 if ((queue_len = skb_queue_len(&offload->skb_queue)) >
175 (offload->skb_queue_len_max / 8))
176 netdev_dbg(offload->dev, "%s: queue_len=%d\n",
177 __func__, queue_len);
178
179 can_rx_offload_schedule(offload);
180 }
181
182 return skb_queue_len(&skb_queue);
183}
184EXPORT_SYMBOL_GPL(can_rx_offload_irq_offload_timestamp);
185
186int can_rx_offload_irq_offload_fifo(struct can_rx_offload *offload)
187{
188 struct sk_buff *skb;
189 int received = 0;
190
191 while ((skb = can_rx_offload_offload_one(offload, 0))) {
192 skb_queue_tail(&offload->skb_queue, skb);
193 received++;
194 }
195
196 if (received)
197 can_rx_offload_schedule(offload);
198
199 return received;
200}
201EXPORT_SYMBOL_GPL(can_rx_offload_irq_offload_fifo);
202
203int can_rx_offload_queue_sorted(struct can_rx_offload *offload,
204 struct sk_buff *skb, u32 timestamp)
205{
206 struct can_rx_offload_cb *cb;
207 unsigned long flags;
208
209 if (skb_queue_len(&offload->skb_queue) >
210 offload->skb_queue_len_max)
211 return -ENOMEM;
212
213 cb = can_rx_offload_get_cb(skb);
214 cb->timestamp = timestamp;
215
216 spin_lock_irqsave(&offload->skb_queue.lock, flags);
217 __skb_queue_add_sort(&offload->skb_queue, skb, can_rx_offload_compare);
218 spin_unlock_irqrestore(&offload->skb_queue.lock, flags);
219
220 can_rx_offload_schedule(offload);
221
222 return 0;
223}
224EXPORT_SYMBOL_GPL(can_rx_offload_queue_sorted);
225
226unsigned int can_rx_offload_get_echo_skb(struct can_rx_offload *offload,
227 unsigned int idx, u32 timestamp)
228{
229 struct net_device *dev = offload->dev;
230 struct net_device_stats *stats = &dev->stats;
231 struct sk_buff *skb;
232 u8 len;
233 int err;
234
235 skb = __can_get_echo_skb(dev, idx, &len);
236 if (!skb)
237 return 0;
238
239 err = can_rx_offload_queue_sorted(offload, skb, timestamp);
240 if (err) {
241 stats->rx_errors++;
242 stats->tx_fifo_errors++;
243 }
244
245 return len;
246}
247EXPORT_SYMBOL_GPL(can_rx_offload_get_echo_skb);
248
249int can_rx_offload_queue_tail(struct can_rx_offload *offload,
250 struct sk_buff *skb)
251{
252 if (skb_queue_len(&offload->skb_queue) >
253 offload->skb_queue_len_max)
254 return -ENOMEM;
255
256 skb_queue_tail(&offload->skb_queue, skb);
257 can_rx_offload_schedule(offload);
258
259 return 0;
260}
261EXPORT_SYMBOL_GPL(can_rx_offload_queue_tail);
262
263static int can_rx_offload_init_queue(struct net_device *dev, struct can_rx_offload *offload, unsigned int weight)
264{
265 offload->dev = dev;
266
267
268 offload->skb_queue_len_max = 2 << fls(weight);
269 offload->skb_queue_len_max *= 4;
270 skb_queue_head_init(&offload->skb_queue);
271
272 can_rx_offload_reset(offload);
273 netif_napi_add(dev, &offload->napi, can_rx_offload_napi_poll, weight);
274
275 dev_dbg(dev->dev.parent, "%s: skb_queue_len_max=%d\n",
276 __func__, offload->skb_queue_len_max);
277
278 return 0;
279}
280
281int can_rx_offload_add_timestamp(struct net_device *dev, struct can_rx_offload *offload)
282{
283 unsigned int weight;
284
285 if (offload->mb_first > BITS_PER_LONG_LONG ||
286 offload->mb_last > BITS_PER_LONG_LONG || !offload->mailbox_read)
287 return -EINVAL;
288
289 if (offload->mb_first < offload->mb_last) {
290 offload->inc = true;
291 weight = offload->mb_last - offload->mb_first;
292 } else {
293 offload->inc = false;
294 weight = offload->mb_first - offload->mb_last;
295 }
296
297 return can_rx_offload_init_queue(dev, offload, weight);
298}
299EXPORT_SYMBOL_GPL(can_rx_offload_add_timestamp);
300
301int can_rx_offload_add_fifo(struct net_device *dev, struct can_rx_offload *offload, unsigned int weight)
302{
303 if (!offload->mailbox_read)
304 return -EINVAL;
305
306 return can_rx_offload_init_queue(dev, offload, weight);
307}
308EXPORT_SYMBOL_GPL(can_rx_offload_add_fifo);
309
310void can_rx_offload_enable(struct can_rx_offload *offload)
311{
312 can_rx_offload_reset(offload);
313 napi_enable(&offload->napi);
314}
315EXPORT_SYMBOL_GPL(can_rx_offload_enable);
316
317void can_rx_offload_del(struct can_rx_offload *offload)
318{
319 netif_napi_del(&offload->napi);
320 skb_queue_purge(&offload->skb_queue);
321}
322EXPORT_SYMBOL_GPL(can_rx_offload_del);
323
324void can_rx_offload_reset(struct can_rx_offload *offload)
325{
326}
327EXPORT_SYMBOL_GPL(can_rx_offload_reset);
328
