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/gfp.h>
19 #include <linux/module.h>
20 #include <linux/mISDNhw.h>
21
22 static void
dchannel_bh(struct work_struct * ws)23 dchannel_bh(struct work_struct *ws)
24 {
25 struct dchannel *dch = container_of(ws, struct dchannel, workq);
26 struct sk_buff *skb;
27 int err;
28
29 if (test_and_clear_bit(FLG_RECVQUEUE, &dch->Flags)) {
30 while ((skb = skb_dequeue(&dch->rqueue))) {
31 if (likely(dch->dev.D.peer)) {
32 err = dch->dev.D.recv(dch->dev.D.peer, skb);
33 if (err)
34 dev_kfree_skb(skb);
35 } else
36 dev_kfree_skb(skb);
37 }
38 }
39 if (test_and_clear_bit(FLG_PHCHANGE, &dch->Flags)) {
40 if (dch->phfunc)
41 dch->phfunc(dch);
42 }
43 }
44
45 static void
bchannel_bh(struct work_struct * ws)46 bchannel_bh(struct work_struct *ws)
47 {
48 struct bchannel *bch = container_of(ws, struct bchannel, workq);
49 struct sk_buff *skb;
50 int err;
51
52 if (test_and_clear_bit(FLG_RECVQUEUE, &bch->Flags)) {
53 while ((skb = skb_dequeue(&bch->rqueue))) {
54 bch->rcount--;
55 if (likely(bch->ch.peer)) {
56 err = bch->ch.recv(bch->ch.peer, skb);
57 if (err)
58 dev_kfree_skb(skb);
59 } else
60 dev_kfree_skb(skb);
61 }
62 }
63 }
64
65 int
mISDN_initdchannel(struct dchannel * ch,int maxlen,void * phf)66 mISDN_initdchannel(struct dchannel *ch, int maxlen, void *phf)
67 {
68 test_and_set_bit(FLG_HDLC, &ch->Flags);
69 ch->maxlen = maxlen;
70 ch->hw = NULL;
71 ch->rx_skb = NULL;
72 ch->tx_skb = NULL;
73 ch->tx_idx = 0;
74 ch->phfunc = phf;
75 skb_queue_head_init(&ch->squeue);
76 skb_queue_head_init(&ch->rqueue);
77 INIT_LIST_HEAD(&ch->dev.bchannels);
78 INIT_WORK(&ch->workq, dchannel_bh);
79 return 0;
80 }
81 EXPORT_SYMBOL(mISDN_initdchannel);
82
83 int
mISDN_initbchannel(struct bchannel * ch,unsigned short maxlen,unsigned short minlen)84 mISDN_initbchannel(struct bchannel *ch, unsigned short maxlen,
85 unsigned short minlen)
86 {
87 ch->Flags = 0;
88 ch->minlen = minlen;
89 ch->next_minlen = minlen;
90 ch->init_minlen = minlen;
91 ch->maxlen = maxlen;
92 ch->next_maxlen = maxlen;
93 ch->init_maxlen = maxlen;
94 ch->hw = NULL;
95 ch->rx_skb = NULL;
96 ch->tx_skb = NULL;
97 ch->tx_idx = 0;
98 skb_queue_head_init(&ch->rqueue);
99 ch->rcount = 0;
100 ch->next_skb = NULL;
101 INIT_WORK(&ch->workq, bchannel_bh);
102 return 0;
103 }
104 EXPORT_SYMBOL(mISDN_initbchannel);
105
106 int
mISDN_freedchannel(struct dchannel * ch)107 mISDN_freedchannel(struct dchannel *ch)
108 {
109 if (ch->tx_skb) {
110 dev_kfree_skb(ch->tx_skb);
111 ch->tx_skb = NULL;
112 }
113 if (ch->rx_skb) {
114 dev_kfree_skb(ch->rx_skb);
115 ch->rx_skb = NULL;
116 }
117 skb_queue_purge(&ch->squeue);
118 skb_queue_purge(&ch->rqueue);
119 flush_work(&ch->workq);
120 return 0;
121 }
122 EXPORT_SYMBOL(mISDN_freedchannel);
123
124 void
mISDN_clear_bchannel(struct bchannel * ch)125 mISDN_clear_bchannel(struct bchannel *ch)
126 {
127 if (ch->tx_skb) {
128 dev_kfree_skb(ch->tx_skb);
129 ch->tx_skb = NULL;
130 }
131 ch->tx_idx = 0;
132 if (ch->rx_skb) {
133 dev_kfree_skb(ch->rx_skb);
134 ch->rx_skb = NULL;
135 }
136 if (ch->next_skb) {
137 dev_kfree_skb(ch->next_skb);
138 ch->next_skb = NULL;
139 }
140 test_and_clear_bit(FLG_TX_BUSY, &ch->Flags);
141 test_and_clear_bit(FLG_TX_NEXT, &ch->Flags);
142 test_and_clear_bit(FLG_ACTIVE, &ch->Flags);
143 test_and_clear_bit(FLG_FILLEMPTY, &ch->Flags);
144 test_and_clear_bit(FLG_TX_EMPTY, &ch->Flags);
145 test_and_clear_bit(FLG_RX_OFF, &ch->Flags);
146 ch->dropcnt = 0;
147 ch->minlen = ch->init_minlen;
148 ch->next_minlen = ch->init_minlen;
149 ch->maxlen = ch->init_maxlen;
150 ch->next_maxlen = ch->init_maxlen;
151 skb_queue_purge(&ch->rqueue);
152 ch->rcount = 0;
153 }
154 EXPORT_SYMBOL(mISDN_clear_bchannel);
155
156 void
mISDN_freebchannel(struct bchannel * ch)157 mISDN_freebchannel(struct bchannel *ch)
158 {
159 cancel_work_sync(&ch->workq);
160 mISDN_clear_bchannel(ch);
161 }
162 EXPORT_SYMBOL(mISDN_freebchannel);
163
164 int
mISDN_ctrl_bchannel(struct bchannel * bch,struct mISDN_ctrl_req * cq)165 mISDN_ctrl_bchannel(struct bchannel *bch, struct mISDN_ctrl_req *cq)
166 {
167 int ret = 0;
168
169 switch (cq->op) {
170 case MISDN_CTRL_GETOP:
171 cq->op = MISDN_CTRL_RX_BUFFER | MISDN_CTRL_FILL_EMPTY |
172 MISDN_CTRL_RX_OFF;
173 break;
174 case MISDN_CTRL_FILL_EMPTY:
175 if (cq->p1) {
176 memset(bch->fill, cq->p2 & 0xff, MISDN_BCH_FILL_SIZE);
177 test_and_set_bit(FLG_FILLEMPTY, &bch->Flags);
178 } else {
179 test_and_clear_bit(FLG_FILLEMPTY, &bch->Flags);
180 }
181 break;
182 case MISDN_CTRL_RX_OFF:
183 /* read back dropped byte count */
184 cq->p2 = bch->dropcnt;
185 if (cq->p1)
186 test_and_set_bit(FLG_RX_OFF, &bch->Flags);
187 else
188 test_and_clear_bit(FLG_RX_OFF, &bch->Flags);
189 bch->dropcnt = 0;
190 break;
191 case MISDN_CTRL_RX_BUFFER:
192 if (cq->p2 > MISDN_CTRL_RX_SIZE_IGNORE)
193 bch->next_maxlen = cq->p2;
194 if (cq->p1 > MISDN_CTRL_RX_SIZE_IGNORE)
195 bch->next_minlen = cq->p1;
196 /* we return the old values */
197 cq->p1 = bch->minlen;
198 cq->p2 = bch->maxlen;
199 break;
200 default:
201 pr_info("mISDN unhandled control %x operation\n", cq->op);
202 ret = -EINVAL;
203 break;
204 }
205 return ret;
206 }
207 EXPORT_SYMBOL(mISDN_ctrl_bchannel);
208
209 static inline u_int
get_sapi_tei(u_char * p)210 get_sapi_tei(u_char *p)
211 {
212 u_int sapi, tei;
213
214 sapi = *p >> 2;
215 tei = p[1] >> 1;
216 return sapi | (tei << 8);
217 }
218
219 void
recv_Dchannel(struct dchannel * dch)220 recv_Dchannel(struct dchannel *dch)
221 {
222 struct mISDNhead *hh;
223
224 if (dch->rx_skb->len < 2) { /* at least 2 for sapi / tei */
225 dev_kfree_skb(dch->rx_skb);
226 dch->rx_skb = NULL;
227 return;
228 }
229 hh = mISDN_HEAD_P(dch->rx_skb);
230 hh->prim = PH_DATA_IND;
231 hh->id = get_sapi_tei(dch->rx_skb->data);
232 skb_queue_tail(&dch->rqueue, dch->rx_skb);
233 dch->rx_skb = NULL;
234 schedule_event(dch, FLG_RECVQUEUE);
235 }
236 EXPORT_SYMBOL(recv_Dchannel);
237
238 void
recv_Echannel(struct dchannel * ech,struct dchannel * dch)239 recv_Echannel(struct dchannel *ech, struct dchannel *dch)
240 {
241 struct mISDNhead *hh;
242
243 if (ech->rx_skb->len < 2) { /* at least 2 for sapi / tei */
244 dev_kfree_skb(ech->rx_skb);
245 ech->rx_skb = NULL;
246 return;
247 }
248 hh = mISDN_HEAD_P(ech->rx_skb);
249 hh->prim = PH_DATA_E_IND;
250 hh->id = get_sapi_tei(ech->rx_skb->data);
251 skb_queue_tail(&dch->rqueue, ech->rx_skb);
252 ech->rx_skb = NULL;
253 schedule_event(dch, FLG_RECVQUEUE);
254 }
255 EXPORT_SYMBOL(recv_Echannel);
256
257 void
recv_Bchannel(struct bchannel * bch,unsigned int id,bool force)258 recv_Bchannel(struct bchannel *bch, unsigned int id, bool force)
259 {
260 struct mISDNhead *hh;
261
262 /* if allocation did fail upper functions still may call us */
263 if (unlikely(!bch->rx_skb))
264 return;
265 if (unlikely(!bch->rx_skb->len)) {
266 /* we have no data to send - this may happen after recovery
267 * from overflow or too small allocation.
268 * We need to free the buffer here */
269 dev_kfree_skb(bch->rx_skb);
270 bch->rx_skb = NULL;
271 } else {
272 if (test_bit(FLG_TRANSPARENT, &bch->Flags) &&
273 (bch->rx_skb->len < bch->minlen) && !force)
274 return;
275 hh = mISDN_HEAD_P(bch->rx_skb);
276 hh->prim = PH_DATA_IND;
277 hh->id = id;
278 if (bch->rcount >= 64) {
279 printk(KERN_WARNING
280 "B%d receive queue overflow - flushing!\n",
281 bch->nr);
282 skb_queue_purge(&bch->rqueue);
283 }
284 bch->rcount++;
285 skb_queue_tail(&bch->rqueue, bch->rx_skb);
286 bch->rx_skb = NULL;
287 schedule_event(bch, FLG_RECVQUEUE);
288 }
289 }
290 EXPORT_SYMBOL(recv_Bchannel);
291
292 void
recv_Dchannel_skb(struct dchannel * dch,struct sk_buff * skb)293 recv_Dchannel_skb(struct dchannel *dch, struct sk_buff *skb)
294 {
295 skb_queue_tail(&dch->rqueue, skb);
296 schedule_event(dch, FLG_RECVQUEUE);
297 }
298 EXPORT_SYMBOL(recv_Dchannel_skb);
299
300 void
recv_Bchannel_skb(struct bchannel * bch,struct sk_buff * skb)301 recv_Bchannel_skb(struct bchannel *bch, struct sk_buff *skb)
302 {
303 if (bch->rcount >= 64) {
304 printk(KERN_WARNING "B-channel %p receive queue overflow, "
305 "flushing!\n", bch);
306 skb_queue_purge(&bch->rqueue);
307 bch->rcount = 0;
308 }
309 bch->rcount++;
310 skb_queue_tail(&bch->rqueue, skb);
311 schedule_event(bch, FLG_RECVQUEUE);
312 }
313 EXPORT_SYMBOL(recv_Bchannel_skb);
314
315 static void
confirm_Dsend(struct dchannel * dch)316 confirm_Dsend(struct dchannel *dch)
317 {
318 struct sk_buff *skb;
319
320 skb = _alloc_mISDN_skb(PH_DATA_CNF, mISDN_HEAD_ID(dch->tx_skb),
321 0, NULL, GFP_ATOMIC);
322 if (!skb) {
323 printk(KERN_ERR "%s: no skb id %x\n", __func__,
324 mISDN_HEAD_ID(dch->tx_skb));
325 return;
326 }
327 skb_queue_tail(&dch->rqueue, skb);
328 schedule_event(dch, FLG_RECVQUEUE);
329 }
330
331 int
get_next_dframe(struct dchannel * dch)332 get_next_dframe(struct dchannel *dch)
333 {
334 dch->tx_idx = 0;
335 dch->tx_skb = skb_dequeue(&dch->squeue);
336 if (dch->tx_skb) {
337 confirm_Dsend(dch);
338 return 1;
339 }
340 dch->tx_skb = NULL;
341 test_and_clear_bit(FLG_TX_BUSY, &dch->Flags);
342 return 0;
343 }
344 EXPORT_SYMBOL(get_next_dframe);
345
346 static void
confirm_Bsend(struct bchannel * bch)347 confirm_Bsend(struct bchannel *bch)
348 {
349 struct sk_buff *skb;
350
351 if (bch->rcount >= 64) {
352 printk(KERN_WARNING "B-channel %p receive queue overflow, "
353 "flushing!\n", bch);
354 skb_queue_purge(&bch->rqueue);
355 bch->rcount = 0;
356 }
357 skb = _alloc_mISDN_skb(PH_DATA_CNF, mISDN_HEAD_ID(bch->tx_skb),
358 0, NULL, GFP_ATOMIC);
359 if (!skb) {
360 printk(KERN_ERR "%s: no skb id %x\n", __func__,
361 mISDN_HEAD_ID(bch->tx_skb));
362 return;
363 }
364 bch->rcount++;
365 skb_queue_tail(&bch->rqueue, skb);
366 schedule_event(bch, FLG_RECVQUEUE);
367 }
368
369 int
get_next_bframe(struct bchannel * bch)370 get_next_bframe(struct bchannel *bch)
371 {
372 bch->tx_idx = 0;
373 if (test_bit(FLG_TX_NEXT, &bch->Flags)) {
374 bch->tx_skb = bch->next_skb;
375 if (bch->tx_skb) {
376 bch->next_skb = NULL;
377 test_and_clear_bit(FLG_TX_NEXT, &bch->Flags);
378 /* confirm imediately to allow next data */
379 confirm_Bsend(bch);
380 return 1;
381 } else {
382 test_and_clear_bit(FLG_TX_NEXT, &bch->Flags);
383 printk(KERN_WARNING "B TX_NEXT without skb\n");
384 }
385 }
386 bch->tx_skb = NULL;
387 test_and_clear_bit(FLG_TX_BUSY, &bch->Flags);
388 return 0;
389 }
390 EXPORT_SYMBOL(get_next_bframe);
391
392 void
queue_ch_frame(struct mISDNchannel * ch,u_int pr,int id,struct sk_buff * skb)393 queue_ch_frame(struct mISDNchannel *ch, u_int pr, int id, struct sk_buff *skb)
394 {
395 struct mISDNhead *hh;
396
397 if (!skb) {
398 _queue_data(ch, pr, id, 0, NULL, GFP_ATOMIC);
399 } else {
400 if (ch->peer) {
401 hh = mISDN_HEAD_P(skb);
402 hh->prim = pr;
403 hh->id = id;
404 if (!ch->recv(ch->peer, skb))
405 return;
406 }
407 dev_kfree_skb(skb);
408 }
409 }
410 EXPORT_SYMBOL(queue_ch_frame);
411
412 int
dchannel_senddata(struct dchannel * ch,struct sk_buff * skb)413 dchannel_senddata(struct dchannel *ch, struct sk_buff *skb)
414 {
415 /* check oversize */
416 if (skb->len <= 0) {
417 printk(KERN_WARNING "%s: skb too small\n", __func__);
418 return -EINVAL;
419 }
420 if (skb->len > ch->maxlen) {
421 printk(KERN_WARNING "%s: skb too large(%d/%d)\n",
422 __func__, skb->len, ch->maxlen);
423 return -EINVAL;
424 }
425 /* HW lock must be obtained */
426 if (test_and_set_bit(FLG_TX_BUSY, &ch->Flags)) {
427 skb_queue_tail(&ch->squeue, skb);
428 return 0;
429 } else {
430 /* write to fifo */
431 ch->tx_skb = skb;
432 ch->tx_idx = 0;
433 return 1;
434 }
435 }
436 EXPORT_SYMBOL(dchannel_senddata);
437
438 int
bchannel_senddata(struct bchannel * ch,struct sk_buff * skb)439 bchannel_senddata(struct bchannel *ch, struct sk_buff *skb)
440 {
441
442 /* check oversize */
443 if (skb->len <= 0) {
444 printk(KERN_WARNING "%s: skb too small\n", __func__);
445 return -EINVAL;
446 }
447 if (skb->len > ch->maxlen) {
448 printk(KERN_WARNING "%s: skb too large(%d/%d)\n",
449 __func__, skb->len, ch->maxlen);
450 return -EINVAL;
451 }
452 /* HW lock must be obtained */
453 /* check for pending next_skb */
454 if (ch->next_skb) {
455 printk(KERN_WARNING
456 "%s: next_skb exist ERROR (skb->len=%d next_skb->len=%d)\n",
457 __func__, skb->len, ch->next_skb->len);
458 return -EBUSY;
459 }
460 if (test_and_set_bit(FLG_TX_BUSY, &ch->Flags)) {
461 test_and_set_bit(FLG_TX_NEXT, &ch->Flags);
462 ch->next_skb = skb;
463 return 0;
464 } else {
465 /* write to fifo */
466 ch->tx_skb = skb;
467 ch->tx_idx = 0;
468 confirm_Bsend(ch);
469 return 1;
470 }
471 }
472 EXPORT_SYMBOL(bchannel_senddata);
473
474 /* The function allocates a new receive skb on demand with a size for the
475 * requirements of the current protocol. It returns the tailroom of the
476 * receive skb or an error.
477 */
478 int
bchannel_get_rxbuf(struct bchannel * bch,int reqlen)479 bchannel_get_rxbuf(struct bchannel *bch, int reqlen)
480 {
481 int len;
482
483 if (bch->rx_skb) {
484 len = skb_tailroom(bch->rx_skb);
485 if (len < reqlen) {
486 pr_warning("B%d no space for %d (only %d) bytes\n",
487 bch->nr, reqlen, len);
488 if (test_bit(FLG_TRANSPARENT, &bch->Flags)) {
489 /* send what we have now and try a new buffer */
490 recv_Bchannel(bch, 0, true);
491 } else {
492 /* on HDLC we have to drop too big frames */
493 return -EMSGSIZE;
494 }
495 } else {
496 return len;
497 }
498 }
499 /* update current min/max length first */
500 if (unlikely(bch->maxlen != bch->next_maxlen))
501 bch->maxlen = bch->next_maxlen;
502 if (unlikely(bch->minlen != bch->next_minlen))
503 bch->minlen = bch->next_minlen;
504 if (unlikely(reqlen > bch->maxlen))
505 return -EMSGSIZE;
506 if (test_bit(FLG_TRANSPARENT, &bch->Flags)) {
507 if (reqlen >= bch->minlen) {
508 len = reqlen;
509 } else {
510 len = 2 * bch->minlen;
511 if (len > bch->maxlen)
512 len = bch->maxlen;
513 }
514 } else {
515 /* with HDLC we do not know the length yet */
516 len = bch->maxlen;
517 }
518 bch->rx_skb = mI_alloc_skb(len, GFP_ATOMIC);
519 if (!bch->rx_skb) {
520 pr_warning("B%d receive no memory for %d bytes\n",
521 bch->nr, len);
522 len = -ENOMEM;
523 }
524 return len;
525 }
526 EXPORT_SYMBOL(bchannel_get_rxbuf);
527