xref: /openbmc/linux/drivers/isdn/mISDN/hwchannel.c (revision 4b2a108c)
1 /*
2  *
3  * Author	Karsten Keil <kkeil@novell.com>
4  *
5  * Copyright 2008  by Karsten Keil <kkeil@novell.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  */
17 
18 #include <linux/module.h>
19 #include <linux/mISDNhw.h>
20 
21 static void
22 dchannel_bh(struct work_struct *ws)
23 {
24 	struct dchannel	*dch  = container_of(ws, struct dchannel, workq);
25 	struct sk_buff	*skb;
26 	int		err;
27 
28 	if (test_and_clear_bit(FLG_RECVQUEUE, &dch->Flags)) {
29 		while ((skb = skb_dequeue(&dch->rqueue))) {
30 			if (likely(dch->dev.D.peer)) {
31 				err = dch->dev.D.recv(dch->dev.D.peer, skb);
32 				if (err)
33 					dev_kfree_skb(skb);
34 			} else
35 				dev_kfree_skb(skb);
36 		}
37 	}
38 	if (test_and_clear_bit(FLG_PHCHANGE, &dch->Flags)) {
39 		if (dch->phfunc)
40 			dch->phfunc(dch);
41 	}
42 }
43 
44 static void
45 bchannel_bh(struct work_struct *ws)
46 {
47 	struct bchannel	*bch  = container_of(ws, struct bchannel, workq);
48 	struct sk_buff	*skb;
49 	int		err;
50 
51 	if (test_and_clear_bit(FLG_RECVQUEUE, &bch->Flags)) {
52 		while ((skb = skb_dequeue(&bch->rqueue))) {
53 			bch->rcount--;
54 			if (likely(bch->ch.peer)) {
55 				err = bch->ch.recv(bch->ch.peer, skb);
56 				if (err)
57 					dev_kfree_skb(skb);
58 			} else
59 				dev_kfree_skb(skb);
60 		}
61 	}
62 }
63 
64 int
65 mISDN_initdchannel(struct dchannel *ch, int maxlen, void *phf)
66 {
67 	test_and_set_bit(FLG_HDLC, &ch->Flags);
68 	ch->maxlen = maxlen;
69 	ch->hw = NULL;
70 	ch->rx_skb = NULL;
71 	ch->tx_skb = NULL;
72 	ch->tx_idx = 0;
73 	ch->phfunc = phf;
74 	skb_queue_head_init(&ch->squeue);
75 	skb_queue_head_init(&ch->rqueue);
76 	INIT_LIST_HEAD(&ch->dev.bchannels);
77 	INIT_WORK(&ch->workq, dchannel_bh);
78 	return 0;
79 }
80 EXPORT_SYMBOL(mISDN_initdchannel);
81 
82 int
83 mISDN_initbchannel(struct bchannel *ch, int maxlen)
84 {
85 	ch->Flags = 0;
86 	ch->maxlen = maxlen;
87 	ch->hw = NULL;
88 	ch->rx_skb = NULL;
89 	ch->tx_skb = NULL;
90 	ch->tx_idx = 0;
91 	skb_queue_head_init(&ch->rqueue);
92 	ch->rcount = 0;
93 	ch->next_skb = NULL;
94 	INIT_WORK(&ch->workq, bchannel_bh);
95 	return 0;
96 }
97 EXPORT_SYMBOL(mISDN_initbchannel);
98 
99 int
100 mISDN_freedchannel(struct dchannel *ch)
101 {
102 	if (ch->tx_skb) {
103 		dev_kfree_skb(ch->tx_skb);
104 		ch->tx_skb = NULL;
105 	}
106 	if (ch->rx_skb) {
107 		dev_kfree_skb(ch->rx_skb);
108 		ch->rx_skb = NULL;
109 	}
110 	skb_queue_purge(&ch->squeue);
111 	skb_queue_purge(&ch->rqueue);
112 	flush_scheduled_work();
113 	return 0;
114 }
115 EXPORT_SYMBOL(mISDN_freedchannel);
116 
117 int
118 mISDN_freebchannel(struct bchannel *ch)
119 {
120 	if (ch->tx_skb) {
121 		dev_kfree_skb(ch->tx_skb);
122 		ch->tx_skb = NULL;
123 	}
124 	if (ch->rx_skb) {
125 		dev_kfree_skb(ch->rx_skb);
126 		ch->rx_skb = NULL;
127 	}
128 	if (ch->next_skb) {
129 		dev_kfree_skb(ch->next_skb);
130 		ch->next_skb = NULL;
131 	}
132 	skb_queue_purge(&ch->rqueue);
133 	ch->rcount = 0;
134 	flush_scheduled_work();
135 	return 0;
136 }
137 EXPORT_SYMBOL(mISDN_freebchannel);
138 
139 static inline u_int
140 get_sapi_tei(u_char *p)
141 {
142 	u_int	sapi, tei;
143 
144 	sapi = *p >> 2;
145 	tei = p[1] >> 1;
146 	return sapi | (tei << 8);
147 }
148 
149 void
150 recv_Dchannel(struct dchannel *dch)
151 {
152 	struct mISDNhead *hh;
153 
154 	if (dch->rx_skb->len < 2) { /* at least 2 for sapi / tei */
155 		dev_kfree_skb(dch->rx_skb);
156 		dch->rx_skb = NULL;
157 		return;
158 	}
159 	hh = mISDN_HEAD_P(dch->rx_skb);
160 	hh->prim = PH_DATA_IND;
161 	hh->id = get_sapi_tei(dch->rx_skb->data);
162 	skb_queue_tail(&dch->rqueue, dch->rx_skb);
163 	dch->rx_skb = NULL;
164 	schedule_event(dch, FLG_RECVQUEUE);
165 }
166 EXPORT_SYMBOL(recv_Dchannel);
167 
168 void
169 recv_Echannel(struct dchannel *ech, struct dchannel *dch)
170 {
171 	struct mISDNhead *hh;
172 
173 	if (ech->rx_skb->len < 2) { /* at least 2 for sapi / tei */
174 		dev_kfree_skb(ech->rx_skb);
175 		ech->rx_skb = NULL;
176 		return;
177 	}
178 	hh = mISDN_HEAD_P(ech->rx_skb);
179 	hh->prim = PH_DATA_E_IND;
180 	hh->id = get_sapi_tei(ech->rx_skb->data);
181 	skb_queue_tail(&dch->rqueue, ech->rx_skb);
182 	ech->rx_skb = NULL;
183 	schedule_event(dch, FLG_RECVQUEUE);
184 }
185 EXPORT_SYMBOL(recv_Echannel);
186 
187 void
188 recv_Bchannel(struct bchannel *bch, unsigned int id)
189 {
190 	struct mISDNhead *hh;
191 
192 	hh = mISDN_HEAD_P(bch->rx_skb);
193 	hh->prim = PH_DATA_IND;
194 	hh->id = id;
195 	if (bch->rcount >= 64) {
196 		printk(KERN_WARNING "B-channel %p receive queue overflow, "
197 			"fushing!\n", bch);
198 		skb_queue_purge(&bch->rqueue);
199 		bch->rcount = 0;
200 		return;
201 	}
202 	bch->rcount++;
203 	skb_queue_tail(&bch->rqueue, bch->rx_skb);
204 	bch->rx_skb = NULL;
205 	schedule_event(bch, FLG_RECVQUEUE);
206 }
207 EXPORT_SYMBOL(recv_Bchannel);
208 
209 void
210 recv_Dchannel_skb(struct dchannel *dch, struct sk_buff *skb)
211 {
212 	skb_queue_tail(&dch->rqueue, skb);
213 	schedule_event(dch, FLG_RECVQUEUE);
214 }
215 EXPORT_SYMBOL(recv_Dchannel_skb);
216 
217 void
218 recv_Bchannel_skb(struct bchannel *bch, struct sk_buff *skb)
219 {
220 	if (bch->rcount >= 64) {
221 		printk(KERN_WARNING "B-channel %p receive queue overflow, "
222 			"fushing!\n", bch);
223 		skb_queue_purge(&bch->rqueue);
224 		bch->rcount = 0;
225 	}
226 	bch->rcount++;
227 	skb_queue_tail(&bch->rqueue, skb);
228 	schedule_event(bch, FLG_RECVQUEUE);
229 }
230 EXPORT_SYMBOL(recv_Bchannel_skb);
231 
232 static void
233 confirm_Dsend(struct dchannel *dch)
234 {
235 	struct sk_buff	*skb;
236 
237 	skb = _alloc_mISDN_skb(PH_DATA_CNF, mISDN_HEAD_ID(dch->tx_skb),
238 	    0, NULL, GFP_ATOMIC);
239 	if (!skb) {
240 		printk(KERN_ERR "%s: no skb id %x\n", __func__,
241 		    mISDN_HEAD_ID(dch->tx_skb));
242 		return;
243 	}
244 	skb_queue_tail(&dch->rqueue, skb);
245 	schedule_event(dch, FLG_RECVQUEUE);
246 }
247 
248 int
249 get_next_dframe(struct dchannel *dch)
250 {
251 	dch->tx_idx = 0;
252 	dch->tx_skb = skb_dequeue(&dch->squeue);
253 	if (dch->tx_skb) {
254 		confirm_Dsend(dch);
255 		return 1;
256 	}
257 	dch->tx_skb = NULL;
258 	test_and_clear_bit(FLG_TX_BUSY, &dch->Flags);
259 	return 0;
260 }
261 EXPORT_SYMBOL(get_next_dframe);
262 
263 void
264 confirm_Bsend(struct bchannel *bch)
265 {
266 	struct sk_buff	*skb;
267 
268 	if (bch->rcount >= 64) {
269 		printk(KERN_WARNING "B-channel %p receive queue overflow, "
270 			"fushing!\n", bch);
271 		skb_queue_purge(&bch->rqueue);
272 		bch->rcount = 0;
273 	}
274 	skb = _alloc_mISDN_skb(PH_DATA_CNF, mISDN_HEAD_ID(bch->tx_skb),
275 	    0, NULL, GFP_ATOMIC);
276 	if (!skb) {
277 		printk(KERN_ERR "%s: no skb id %x\n", __func__,
278 		    mISDN_HEAD_ID(bch->tx_skb));
279 		return;
280 	}
281 	bch->rcount++;
282 	skb_queue_tail(&bch->rqueue, skb);
283 	schedule_event(bch, FLG_RECVQUEUE);
284 }
285 EXPORT_SYMBOL(confirm_Bsend);
286 
287 int
288 get_next_bframe(struct bchannel *bch)
289 {
290 	bch->tx_idx = 0;
291 	if (test_bit(FLG_TX_NEXT, &bch->Flags)) {
292 		bch->tx_skb = bch->next_skb;
293 		if (bch->tx_skb) {
294 			bch->next_skb = NULL;
295 			test_and_clear_bit(FLG_TX_NEXT, &bch->Flags);
296 			if (!test_bit(FLG_TRANSPARENT, &bch->Flags))
297 				confirm_Bsend(bch); /* not for transparent */
298 			return 1;
299 		} else {
300 			test_and_clear_bit(FLG_TX_NEXT, &bch->Flags);
301 			printk(KERN_WARNING "B TX_NEXT without skb\n");
302 		}
303 	}
304 	bch->tx_skb = NULL;
305 	test_and_clear_bit(FLG_TX_BUSY, &bch->Flags);
306 	return 0;
307 }
308 EXPORT_SYMBOL(get_next_bframe);
309 
310 void
311 queue_ch_frame(struct mISDNchannel *ch, u_int pr, int id, struct sk_buff *skb)
312 {
313 	struct mISDNhead *hh;
314 
315 	if (!skb) {
316 		_queue_data(ch, pr, id, 0, NULL, GFP_ATOMIC);
317 	} else {
318 		if (ch->peer) {
319 			hh = mISDN_HEAD_P(skb);
320 			hh->prim = pr;
321 			hh->id = id;
322 			if (!ch->recv(ch->peer, skb))
323 				return;
324 		}
325 		dev_kfree_skb(skb);
326 	}
327 }
328 EXPORT_SYMBOL(queue_ch_frame);
329 
330 int
331 dchannel_senddata(struct dchannel *ch, struct sk_buff *skb)
332 {
333 	/* check oversize */
334 	if (skb->len <= 0) {
335 		printk(KERN_WARNING "%s: skb too small\n", __func__);
336 		return -EINVAL;
337 	}
338 	if (skb->len > ch->maxlen) {
339 		printk(KERN_WARNING "%s: skb too large(%d/%d)\n",
340 			__func__, skb->len, ch->maxlen);
341 		return -EINVAL;
342 	}
343 	/* HW lock must be obtained */
344 	if (test_and_set_bit(FLG_TX_BUSY, &ch->Flags)) {
345 		skb_queue_tail(&ch->squeue, skb);
346 		return 0;
347 	} else {
348 		/* write to fifo */
349 		ch->tx_skb = skb;
350 		ch->tx_idx = 0;
351 		return 1;
352 	}
353 }
354 EXPORT_SYMBOL(dchannel_senddata);
355 
356 int
357 bchannel_senddata(struct bchannel *ch, struct sk_buff *skb)
358 {
359 
360 	/* check oversize */
361 	if (skb->len <= 0) {
362 		printk(KERN_WARNING "%s: skb too small\n", __func__);
363 		return -EINVAL;
364 	}
365 	if (skb->len > ch->maxlen) {
366 		printk(KERN_WARNING "%s: skb too large(%d/%d)\n",
367 			__func__, skb->len, ch->maxlen);
368 		return -EINVAL;
369 	}
370 	/* HW lock must be obtained */
371 	/* check for pending next_skb */
372 	if (ch->next_skb) {
373 		printk(KERN_WARNING
374 		    "%s: next_skb exist ERROR (skb->len=%d next_skb->len=%d)\n",
375 		    __func__, skb->len, ch->next_skb->len);
376 		return -EBUSY;
377 	}
378 	if (test_and_set_bit(FLG_TX_BUSY, &ch->Flags)) {
379 		test_and_set_bit(FLG_TX_NEXT, &ch->Flags);
380 		ch->next_skb = skb;
381 		return 0;
382 	} else {
383 		/* write to fifo */
384 		ch->tx_skb = skb;
385 		ch->tx_idx = 0;
386 		return 1;
387 	}
388 }
389 EXPORT_SYMBOL(bchannel_senddata);
390