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d254586c DJ |
1 | /* |
2 | * Copyright (c) 2014 David Jander, Protonic Holland | |
3 | * Copyright (C) 2014-2017 Pengutronix, Marc Kleine-Budde <kernel@pengutronix.de> | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the version 2 of the GNU General Public License | |
7 | * as published by the Free Software Foundation | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, see <http://www.gnu.org/licenses/>. | |
16 | */ | |
17 | ||
18 | #include <linux/can/dev.h> | |
19 | #include <linux/can/rx-offload.h> | |
20 | ||
3abbac0b MKB |
21 | struct can_rx_offload_cb { |
22 | u32 timestamp; | |
23 | }; | |
24 | ||
25 | static inline struct can_rx_offload_cb *can_rx_offload_get_cb(struct sk_buff *skb) | |
26 | { | |
27 | BUILD_BUG_ON(sizeof(struct can_rx_offload_cb) > sizeof(skb->cb)); | |
28 | ||
29 | return (struct can_rx_offload_cb *)skb->cb; | |
30 | } | |
31 | ||
32 | static inline bool can_rx_offload_le(struct can_rx_offload *offload, unsigned int a, unsigned int b) | |
33 | { | |
34 | if (offload->inc) | |
35 | return a <= b; | |
36 | else | |
37 | return a >= b; | |
38 | } | |
39 | ||
40 | static inline unsigned int can_rx_offload_inc(struct can_rx_offload *offload, unsigned int *val) | |
41 | { | |
42 | if (offload->inc) | |
43 | return (*val)++; | |
44 | else | |
45 | return (*val)--; | |
46 | } | |
47 | ||
d254586c DJ |
48 | static int can_rx_offload_napi_poll(struct napi_struct *napi, int quota) |
49 | { | |
50 | struct can_rx_offload *offload = container_of(napi, struct can_rx_offload, napi); | |
51 | struct net_device *dev = offload->dev; | |
52 | struct net_device_stats *stats = &dev->stats; | |
53 | struct sk_buff *skb; | |
54 | int work_done = 0; | |
55 | ||
56 | while ((work_done < quota) && | |
57 | (skb = skb_dequeue(&offload->skb_queue))) { | |
58 | struct can_frame *cf = (struct can_frame *)skb->data; | |
59 | ||
60 | work_done++; | |
61 | stats->rx_packets++; | |
62 | stats->rx_bytes += cf->can_dlc; | |
63 | netif_receive_skb(skb); | |
64 | } | |
65 | ||
66 | if (work_done < quota) { | |
67 | napi_complete_done(napi, work_done); | |
68 | ||
69 | /* Check if there was another interrupt */ | |
70 | if (!skb_queue_empty(&offload->skb_queue)) | |
71 | napi_reschedule(&offload->napi); | |
72 | } | |
73 | ||
74 | can_led_event(offload->dev, CAN_LED_EVENT_RX); | |
75 | ||
76 | return work_done; | |
77 | } | |
78 | ||
3abbac0b MKB |
79 | static inline void __skb_queue_add_sort(struct sk_buff_head *head, struct sk_buff *new, |
80 | int (*compare)(struct sk_buff *a, struct sk_buff *b)) | |
81 | { | |
82 | struct sk_buff *pos, *insert = (struct sk_buff *)head; | |
83 | ||
84 | skb_queue_reverse_walk(head, pos) { | |
85 | const struct can_rx_offload_cb *cb_pos, *cb_new; | |
86 | ||
87 | cb_pos = can_rx_offload_get_cb(pos); | |
88 | cb_new = can_rx_offload_get_cb(new); | |
89 | ||
90 | netdev_dbg(new->dev, | |
91 | "%s: pos=0x%08x, new=0x%08x, diff=%10d, queue_len=%d\n", | |
92 | __func__, | |
93 | cb_pos->timestamp, cb_new->timestamp, | |
94 | cb_new->timestamp - cb_pos->timestamp, | |
95 | skb_queue_len(head)); | |
96 | ||
97 | if (compare(pos, new) < 0) | |
98 | continue; | |
99 | insert = pos; | |
100 | break; | |
101 | } | |
102 | ||
103 | __skb_queue_after(head, insert, new); | |
104 | } | |
105 | ||
106 | static int can_rx_offload_compare(struct sk_buff *a, struct sk_buff *b) | |
107 | { | |
108 | const struct can_rx_offload_cb *cb_a, *cb_b; | |
109 | ||
110 | cb_a = can_rx_offload_get_cb(a); | |
111 | cb_b = can_rx_offload_get_cb(b); | |
112 | ||
113 | /* Substract two u32 and return result as int, to keep | |
114 | * difference steady around the u32 overflow. | |
115 | */ | |
116 | return cb_b->timestamp - cb_a->timestamp; | |
117 | } | |
118 | ||
d254586c DJ |
119 | static struct sk_buff *can_rx_offload_offload_one(struct can_rx_offload *offload, unsigned int n) |
120 | { | |
121 | struct sk_buff *skb = NULL; | |
3abbac0b | 122 | struct can_rx_offload_cb *cb; |
d254586c DJ |
123 | struct can_frame *cf; |
124 | int ret; | |
125 | ||
126 | /* If queue is full or skb not available, read to discard mailbox */ | |
127 | if (likely(skb_queue_len(&offload->skb_queue) <= | |
128 | offload->skb_queue_len_max)) | |
129 | skb = alloc_can_skb(offload->dev, &cf); | |
130 | ||
131 | if (!skb) { | |
132 | struct can_frame cf_overflow; | |
3abbac0b | 133 | u32 timestamp; |
d254586c | 134 | |
3abbac0b MKB |
135 | ret = offload->mailbox_read(offload, &cf_overflow, |
136 | ×tamp, n); | |
d254586c DJ |
137 | if (ret) |
138 | offload->dev->stats.rx_dropped++; | |
139 | ||
140 | return NULL; | |
141 | } | |
142 | ||
3abbac0b MKB |
143 | cb = can_rx_offload_get_cb(skb); |
144 | ret = offload->mailbox_read(offload, cf, &cb->timestamp, n); | |
d254586c DJ |
145 | if (!ret) { |
146 | kfree_skb(skb); | |
147 | return NULL; | |
148 | } | |
149 | ||
150 | return skb; | |
151 | } | |
152 | ||
3abbac0b MKB |
153 | int can_rx_offload_irq_offload_timestamp(struct can_rx_offload *offload, u64 pending) |
154 | { | |
155 | struct sk_buff_head skb_queue; | |
156 | unsigned int i; | |
157 | ||
158 | __skb_queue_head_init(&skb_queue); | |
159 | ||
160 | for (i = offload->mb_first; | |
161 | can_rx_offload_le(offload, i, offload->mb_last); | |
162 | can_rx_offload_inc(offload, &i)) { | |
163 | struct sk_buff *skb; | |
164 | ||
165 | if (!(pending & BIT_ULL(i))) | |
166 | continue; | |
167 | ||
168 | skb = can_rx_offload_offload_one(offload, i); | |
169 | if (!skb) | |
170 | break; | |
171 | ||
172 | __skb_queue_add_sort(&skb_queue, skb, can_rx_offload_compare); | |
173 | } | |
174 | ||
175 | if (!skb_queue_empty(&skb_queue)) { | |
176 | unsigned long flags; | |
177 | u32 queue_len; | |
178 | ||
179 | spin_lock_irqsave(&offload->skb_queue.lock, flags); | |
180 | skb_queue_splice_tail(&skb_queue, &offload->skb_queue); | |
181 | spin_unlock_irqrestore(&offload->skb_queue.lock, flags); | |
182 | ||
183 | if ((queue_len = skb_queue_len(&offload->skb_queue)) > | |
184 | (offload->skb_queue_len_max / 8)) | |
185 | netdev_dbg(offload->dev, "%s: queue_len=%d\n", | |
186 | __func__, queue_len); | |
187 | ||
188 | can_rx_offload_schedule(offload); | |
189 | } | |
190 | ||
191 | return skb_queue_len(&skb_queue); | |
192 | } | |
193 | EXPORT_SYMBOL_GPL(can_rx_offload_irq_offload_timestamp); | |
194 | ||
d254586c DJ |
195 | int can_rx_offload_irq_offload_fifo(struct can_rx_offload *offload) |
196 | { | |
197 | struct sk_buff *skb; | |
198 | int received = 0; | |
199 | ||
200 | while ((skb = can_rx_offload_offload_one(offload, 0))) { | |
201 | skb_queue_tail(&offload->skb_queue, skb); | |
202 | received++; | |
203 | } | |
204 | ||
205 | if (received) | |
206 | can_rx_offload_schedule(offload); | |
207 | ||
208 | return received; | |
209 | } | |
210 | EXPORT_SYMBOL_GPL(can_rx_offload_irq_offload_fifo); | |
211 | ||
212 | int can_rx_offload_irq_queue_err_skb(struct can_rx_offload *offload, struct sk_buff *skb) | |
213 | { | |
214 | if (skb_queue_len(&offload->skb_queue) > | |
215 | offload->skb_queue_len_max) | |
216 | return -ENOMEM; | |
217 | ||
218 | skb_queue_tail(&offload->skb_queue, skb); | |
219 | can_rx_offload_schedule(offload); | |
220 | ||
221 | return 0; | |
222 | } | |
223 | EXPORT_SYMBOL_GPL(can_rx_offload_irq_queue_err_skb); | |
224 | ||
225 | static int can_rx_offload_init_queue(struct net_device *dev, struct can_rx_offload *offload, unsigned int weight) | |
226 | { | |
227 | offload->dev = dev; | |
228 | ||
229 | /* Limit queue len to 4x the weight (rounted to next power of two) */ | |
230 | offload->skb_queue_len_max = 2 << fls(weight); | |
231 | offload->skb_queue_len_max *= 4; | |
232 | skb_queue_head_init(&offload->skb_queue); | |
233 | ||
234 | can_rx_offload_reset(offload); | |
235 | netif_napi_add(dev, &offload->napi, can_rx_offload_napi_poll, weight); | |
236 | ||
237 | dev_dbg(dev->dev.parent, "%s: skb_queue_len_max=%d\n", | |
238 | __func__, offload->skb_queue_len_max); | |
239 | ||
240 | return 0; | |
241 | } | |
242 | ||
3abbac0b MKB |
243 | int can_rx_offload_add_timestamp(struct net_device *dev, struct can_rx_offload *offload) |
244 | { | |
245 | unsigned int weight; | |
246 | ||
247 | if (offload->mb_first > BITS_PER_LONG_LONG || | |
248 | offload->mb_last > BITS_PER_LONG_LONG || !offload->mailbox_read) | |
249 | return -EINVAL; | |
250 | ||
251 | if (offload->mb_first < offload->mb_last) { | |
252 | offload->inc = true; | |
253 | weight = offload->mb_last - offload->mb_first; | |
254 | } else { | |
255 | offload->inc = false; | |
256 | weight = offload->mb_first - offload->mb_last; | |
257 | } | |
258 | ||
41e0a3fd | 259 | return can_rx_offload_init_queue(dev, offload, weight); |
3abbac0b MKB |
260 | } |
261 | EXPORT_SYMBOL_GPL(can_rx_offload_add_timestamp); | |
262 | ||
d254586c DJ |
263 | int can_rx_offload_add_fifo(struct net_device *dev, struct can_rx_offload *offload, unsigned int weight) |
264 | { | |
265 | if (!offload->mailbox_read) | |
266 | return -EINVAL; | |
267 | ||
268 | return can_rx_offload_init_queue(dev, offload, weight); | |
269 | } | |
270 | EXPORT_SYMBOL_GPL(can_rx_offload_add_fifo); | |
271 | ||
272 | void can_rx_offload_enable(struct can_rx_offload *offload) | |
273 | { | |
274 | can_rx_offload_reset(offload); | |
275 | napi_enable(&offload->napi); | |
276 | } | |
277 | EXPORT_SYMBOL_GPL(can_rx_offload_enable); | |
278 | ||
279 | void can_rx_offload_del(struct can_rx_offload *offload) | |
280 | { | |
281 | netif_napi_del(&offload->napi); | |
282 | skb_queue_purge(&offload->skb_queue); | |
283 | } | |
284 | EXPORT_SYMBOL_GPL(can_rx_offload_del); | |
285 | ||
286 | void can_rx_offload_reset(struct can_rx_offload *offload) | |
287 | { | |
288 | } | |
289 | EXPORT_SYMBOL_GPL(can_rx_offload_reset); |