1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * |
4 | * Author Karsten Keil <kkeil@novell.com> |
5 | * |
6 | * Copyright 2008 by Karsten Keil <kkeil@novell.com> |
7 | */ |
8 | |
9 | #include <linux/gfp.h> |
10 | #include <linux/module.h> |
11 | #include <linux/mISDNhw.h> |
12 | |
13 | static void |
14 | dchannel_bh(struct work_struct *ws) |
15 | { |
16 | struct dchannel *dch = container_of(ws, struct dchannel, workq); |
17 | struct sk_buff *skb; |
18 | int err; |
19 | |
20 | if (test_and_clear_bit(FLG_RECVQUEUE, addr: &dch->Flags)) { |
21 | while ((skb = skb_dequeue(list: &dch->rqueue))) { |
22 | if (likely(dch->dev.D.peer)) { |
23 | err = dch->dev.D.recv(dch->dev.D.peer, skb); |
24 | if (err) |
25 | dev_kfree_skb(skb); |
26 | } else |
27 | dev_kfree_skb(skb); |
28 | } |
29 | } |
30 | if (test_and_clear_bit(FLG_PHCHANGE, addr: &dch->Flags)) { |
31 | if (dch->phfunc) |
32 | dch->phfunc(dch); |
33 | } |
34 | } |
35 | |
36 | static void |
37 | bchannel_bh(struct work_struct *ws) |
38 | { |
39 | struct bchannel *bch = container_of(ws, struct bchannel, workq); |
40 | struct sk_buff *skb; |
41 | int err; |
42 | |
43 | if (test_and_clear_bit(FLG_RECVQUEUE, addr: &bch->Flags)) { |
44 | while ((skb = skb_dequeue(list: &bch->rqueue))) { |
45 | bch->rcount--; |
46 | if (likely(bch->ch.peer)) { |
47 | err = bch->ch.recv(bch->ch.peer, skb); |
48 | if (err) |
49 | dev_kfree_skb(skb); |
50 | } else |
51 | dev_kfree_skb(skb); |
52 | } |
53 | } |
54 | } |
55 | |
56 | int |
57 | mISDN_initdchannel(struct dchannel *ch, int maxlen, void *phf) |
58 | { |
59 | test_and_set_bit(FLG_HDLC, addr: &ch->Flags); |
60 | ch->maxlen = maxlen; |
61 | ch->hw = NULL; |
62 | ch->rx_skb = NULL; |
63 | ch->tx_skb = NULL; |
64 | ch->tx_idx = 0; |
65 | ch->phfunc = phf; |
66 | skb_queue_head_init(list: &ch->squeue); |
67 | skb_queue_head_init(list: &ch->rqueue); |
68 | INIT_LIST_HEAD(list: &ch->dev.bchannels); |
69 | INIT_WORK(&ch->workq, dchannel_bh); |
70 | return 0; |
71 | } |
72 | EXPORT_SYMBOL(mISDN_initdchannel); |
73 | |
74 | int |
75 | mISDN_initbchannel(struct bchannel *ch, unsigned short maxlen, |
76 | unsigned short minlen) |
77 | { |
78 | ch->Flags = 0; |
79 | ch->minlen = minlen; |
80 | ch->next_minlen = minlen; |
81 | ch->init_minlen = minlen; |
82 | ch->maxlen = maxlen; |
83 | ch->next_maxlen = maxlen; |
84 | ch->init_maxlen = maxlen; |
85 | ch->hw = NULL; |
86 | ch->rx_skb = NULL; |
87 | ch->tx_skb = NULL; |
88 | ch->tx_idx = 0; |
89 | skb_queue_head_init(list: &ch->rqueue); |
90 | ch->rcount = 0; |
91 | ch->next_skb = NULL; |
92 | INIT_WORK(&ch->workq, bchannel_bh); |
93 | return 0; |
94 | } |
95 | EXPORT_SYMBOL(mISDN_initbchannel); |
96 | |
97 | int |
98 | mISDN_freedchannel(struct dchannel *ch) |
99 | { |
100 | if (ch->tx_skb) { |
101 | dev_kfree_skb(ch->tx_skb); |
102 | ch->tx_skb = NULL; |
103 | } |
104 | if (ch->rx_skb) { |
105 | dev_kfree_skb(ch->rx_skb); |
106 | ch->rx_skb = NULL; |
107 | } |
108 | skb_queue_purge(list: &ch->squeue); |
109 | skb_queue_purge(list: &ch->rqueue); |
110 | flush_work(work: &ch->workq); |
111 | return 0; |
112 | } |
113 | EXPORT_SYMBOL(mISDN_freedchannel); |
114 | |
115 | void |
116 | mISDN_clear_bchannel(struct bchannel *ch) |
117 | { |
118 | if (ch->tx_skb) { |
119 | dev_kfree_skb(ch->tx_skb); |
120 | ch->tx_skb = NULL; |
121 | } |
122 | ch->tx_idx = 0; |
123 | if (ch->rx_skb) { |
124 | dev_kfree_skb(ch->rx_skb); |
125 | ch->rx_skb = NULL; |
126 | } |
127 | if (ch->next_skb) { |
128 | dev_kfree_skb(ch->next_skb); |
129 | ch->next_skb = NULL; |
130 | } |
131 | test_and_clear_bit(FLG_TX_BUSY, addr: &ch->Flags); |
132 | test_and_clear_bit(FLG_TX_NEXT, addr: &ch->Flags); |
133 | test_and_clear_bit(FLG_ACTIVE, addr: &ch->Flags); |
134 | test_and_clear_bit(FLG_FILLEMPTY, addr: &ch->Flags); |
135 | test_and_clear_bit(FLG_TX_EMPTY, addr: &ch->Flags); |
136 | test_and_clear_bit(FLG_RX_OFF, addr: &ch->Flags); |
137 | ch->dropcnt = 0; |
138 | ch->minlen = ch->init_minlen; |
139 | ch->next_minlen = ch->init_minlen; |
140 | ch->maxlen = ch->init_maxlen; |
141 | ch->next_maxlen = ch->init_maxlen; |
142 | skb_queue_purge(list: &ch->rqueue); |
143 | ch->rcount = 0; |
144 | } |
145 | EXPORT_SYMBOL(mISDN_clear_bchannel); |
146 | |
147 | void |
148 | mISDN_freebchannel(struct bchannel *ch) |
149 | { |
150 | cancel_work_sync(work: &ch->workq); |
151 | mISDN_clear_bchannel(ch); |
152 | } |
153 | EXPORT_SYMBOL(mISDN_freebchannel); |
154 | |
155 | int |
156 | mISDN_ctrl_bchannel(struct bchannel *bch, struct mISDN_ctrl_req *cq) |
157 | { |
158 | int ret = 0; |
159 | |
160 | switch (cq->op) { |
161 | case MISDN_CTRL_GETOP: |
162 | cq->op = MISDN_CTRL_RX_BUFFER | MISDN_CTRL_FILL_EMPTY | |
163 | MISDN_CTRL_RX_OFF; |
164 | break; |
165 | case MISDN_CTRL_FILL_EMPTY: |
166 | if (cq->p1) { |
167 | memset(bch->fill, cq->p2 & 0xff, MISDN_BCH_FILL_SIZE); |
168 | test_and_set_bit(FLG_FILLEMPTY, addr: &bch->Flags); |
169 | } else { |
170 | test_and_clear_bit(FLG_FILLEMPTY, addr: &bch->Flags); |
171 | } |
172 | break; |
173 | case MISDN_CTRL_RX_OFF: |
174 | /* read back dropped byte count */ |
175 | cq->p2 = bch->dropcnt; |
176 | if (cq->p1) |
177 | test_and_set_bit(FLG_RX_OFF, addr: &bch->Flags); |
178 | else |
179 | test_and_clear_bit(FLG_RX_OFF, addr: &bch->Flags); |
180 | bch->dropcnt = 0; |
181 | break; |
182 | case MISDN_CTRL_RX_BUFFER: |
183 | if (cq->p2 > MISDN_CTRL_RX_SIZE_IGNORE) |
184 | bch->next_maxlen = cq->p2; |
185 | if (cq->p1 > MISDN_CTRL_RX_SIZE_IGNORE) |
186 | bch->next_minlen = cq->p1; |
187 | /* we return the old values */ |
188 | cq->p1 = bch->minlen; |
189 | cq->p2 = bch->maxlen; |
190 | break; |
191 | default: |
192 | pr_info("mISDN unhandled control %x operation\n" , cq->op); |
193 | ret = -EINVAL; |
194 | break; |
195 | } |
196 | return ret; |
197 | } |
198 | EXPORT_SYMBOL(mISDN_ctrl_bchannel); |
199 | |
200 | static inline u_int |
201 | get_sapi_tei(u_char *p) |
202 | { |
203 | u_int sapi, tei; |
204 | |
205 | sapi = *p >> 2; |
206 | tei = p[1] >> 1; |
207 | return sapi | (tei << 8); |
208 | } |
209 | |
210 | void |
211 | recv_Dchannel(struct dchannel *dch) |
212 | { |
213 | struct mISDNhead *hh; |
214 | |
215 | if (dch->rx_skb->len < 2) { /* at least 2 for sapi / tei */ |
216 | dev_kfree_skb(dch->rx_skb); |
217 | dch->rx_skb = NULL; |
218 | return; |
219 | } |
220 | hh = mISDN_HEAD_P(dch->rx_skb); |
221 | hh->prim = PH_DATA_IND; |
222 | hh->id = get_sapi_tei(p: dch->rx_skb->data); |
223 | skb_queue_tail(list: &dch->rqueue, newsk: dch->rx_skb); |
224 | dch->rx_skb = NULL; |
225 | schedule_event(dch, FLG_RECVQUEUE); |
226 | } |
227 | EXPORT_SYMBOL(recv_Dchannel); |
228 | |
229 | void |
230 | recv_Echannel(struct dchannel *ech, struct dchannel *dch) |
231 | { |
232 | struct mISDNhead *hh; |
233 | |
234 | if (ech->rx_skb->len < 2) { /* at least 2 for sapi / tei */ |
235 | dev_kfree_skb(ech->rx_skb); |
236 | ech->rx_skb = NULL; |
237 | return; |
238 | } |
239 | hh = mISDN_HEAD_P(ech->rx_skb); |
240 | hh->prim = PH_DATA_E_IND; |
241 | hh->id = get_sapi_tei(p: ech->rx_skb->data); |
242 | skb_queue_tail(list: &dch->rqueue, newsk: ech->rx_skb); |
243 | ech->rx_skb = NULL; |
244 | schedule_event(dch, FLG_RECVQUEUE); |
245 | } |
246 | EXPORT_SYMBOL(recv_Echannel); |
247 | |
248 | void |
249 | recv_Bchannel(struct bchannel *bch, unsigned int id, bool force) |
250 | { |
251 | struct mISDNhead *hh; |
252 | |
253 | /* if allocation did fail upper functions still may call us */ |
254 | if (unlikely(!bch->rx_skb)) |
255 | return; |
256 | if (unlikely(!bch->rx_skb->len)) { |
257 | /* we have no data to send - this may happen after recovery |
258 | * from overflow or too small allocation. |
259 | * We need to free the buffer here */ |
260 | dev_kfree_skb(bch->rx_skb); |
261 | bch->rx_skb = NULL; |
262 | } else { |
263 | if (test_bit(FLG_TRANSPARENT, &bch->Flags) && |
264 | (bch->rx_skb->len < bch->minlen) && !force) |
265 | return; |
266 | hh = mISDN_HEAD_P(bch->rx_skb); |
267 | hh->prim = PH_DATA_IND; |
268 | hh->id = id; |
269 | if (bch->rcount >= 64) { |
270 | printk(KERN_WARNING |
271 | "B%d receive queue overflow - flushing!\n" , |
272 | bch->nr); |
273 | skb_queue_purge(list: &bch->rqueue); |
274 | } |
275 | bch->rcount++; |
276 | skb_queue_tail(list: &bch->rqueue, newsk: bch->rx_skb); |
277 | bch->rx_skb = NULL; |
278 | schedule_event(bch, FLG_RECVQUEUE); |
279 | } |
280 | } |
281 | EXPORT_SYMBOL(recv_Bchannel); |
282 | |
283 | void |
284 | recv_Dchannel_skb(struct dchannel *dch, struct sk_buff *skb) |
285 | { |
286 | skb_queue_tail(list: &dch->rqueue, newsk: skb); |
287 | schedule_event(dch, FLG_RECVQUEUE); |
288 | } |
289 | EXPORT_SYMBOL(recv_Dchannel_skb); |
290 | |
291 | void |
292 | recv_Bchannel_skb(struct bchannel *bch, struct sk_buff *skb) |
293 | { |
294 | if (bch->rcount >= 64) { |
295 | printk(KERN_WARNING "B-channel %p receive queue overflow, " |
296 | "flushing!\n" , bch); |
297 | skb_queue_purge(list: &bch->rqueue); |
298 | bch->rcount = 0; |
299 | } |
300 | bch->rcount++; |
301 | skb_queue_tail(list: &bch->rqueue, newsk: skb); |
302 | schedule_event(bch, FLG_RECVQUEUE); |
303 | } |
304 | EXPORT_SYMBOL(recv_Bchannel_skb); |
305 | |
306 | static void |
307 | confirm_Dsend(struct dchannel *dch) |
308 | { |
309 | struct sk_buff *skb; |
310 | |
311 | skb = _alloc_mISDN_skb(PH_DATA_CNF, mISDN_HEAD_ID(dch->tx_skb), |
312 | len: 0, NULL, GFP_ATOMIC); |
313 | if (!skb) { |
314 | printk(KERN_ERR "%s: no skb id %x\n" , __func__, |
315 | mISDN_HEAD_ID(dch->tx_skb)); |
316 | return; |
317 | } |
318 | skb_queue_tail(list: &dch->rqueue, newsk: skb); |
319 | schedule_event(dch, FLG_RECVQUEUE); |
320 | } |
321 | |
322 | int |
323 | get_next_dframe(struct dchannel *dch) |
324 | { |
325 | dch->tx_idx = 0; |
326 | dch->tx_skb = skb_dequeue(list: &dch->squeue); |
327 | if (dch->tx_skb) { |
328 | confirm_Dsend(dch); |
329 | return 1; |
330 | } |
331 | dch->tx_skb = NULL; |
332 | test_and_clear_bit(FLG_TX_BUSY, addr: &dch->Flags); |
333 | return 0; |
334 | } |
335 | EXPORT_SYMBOL(get_next_dframe); |
336 | |
337 | static void |
338 | confirm_Bsend(struct bchannel *bch) |
339 | { |
340 | struct sk_buff *skb; |
341 | |
342 | if (bch->rcount >= 64) { |
343 | printk(KERN_WARNING "B-channel %p receive queue overflow, " |
344 | "flushing!\n" , bch); |
345 | skb_queue_purge(list: &bch->rqueue); |
346 | bch->rcount = 0; |
347 | } |
348 | skb = _alloc_mISDN_skb(PH_DATA_CNF, mISDN_HEAD_ID(bch->tx_skb), |
349 | len: 0, NULL, GFP_ATOMIC); |
350 | if (!skb) { |
351 | printk(KERN_ERR "%s: no skb id %x\n" , __func__, |
352 | mISDN_HEAD_ID(bch->tx_skb)); |
353 | return; |
354 | } |
355 | bch->rcount++; |
356 | skb_queue_tail(list: &bch->rqueue, newsk: skb); |
357 | schedule_event(bch, FLG_RECVQUEUE); |
358 | } |
359 | |
360 | int |
361 | get_next_bframe(struct bchannel *bch) |
362 | { |
363 | bch->tx_idx = 0; |
364 | if (test_bit(FLG_TX_NEXT, &bch->Flags)) { |
365 | bch->tx_skb = bch->next_skb; |
366 | if (bch->tx_skb) { |
367 | bch->next_skb = NULL; |
368 | test_and_clear_bit(FLG_TX_NEXT, addr: &bch->Flags); |
369 | /* confirm imediately to allow next data */ |
370 | confirm_Bsend(bch); |
371 | return 1; |
372 | } else { |
373 | test_and_clear_bit(FLG_TX_NEXT, addr: &bch->Flags); |
374 | printk(KERN_WARNING "B TX_NEXT without skb\n" ); |
375 | } |
376 | } |
377 | bch->tx_skb = NULL; |
378 | test_and_clear_bit(FLG_TX_BUSY, addr: &bch->Flags); |
379 | return 0; |
380 | } |
381 | EXPORT_SYMBOL(get_next_bframe); |
382 | |
383 | void |
384 | queue_ch_frame(struct mISDNchannel *ch, u_int pr, int id, struct sk_buff *skb) |
385 | { |
386 | struct mISDNhead *hh; |
387 | |
388 | if (!skb) { |
389 | _queue_data(ch, prim: pr, id, len: 0, NULL, GFP_ATOMIC); |
390 | } else { |
391 | if (ch->peer) { |
392 | hh = mISDN_HEAD_P(skb); |
393 | hh->prim = pr; |
394 | hh->id = id; |
395 | if (!ch->recv(ch->peer, skb)) |
396 | return; |
397 | } |
398 | dev_kfree_skb(skb); |
399 | } |
400 | } |
401 | EXPORT_SYMBOL(queue_ch_frame); |
402 | |
403 | int |
404 | dchannel_senddata(struct dchannel *ch, struct sk_buff *skb) |
405 | { |
406 | /* check oversize */ |
407 | if (skb->len <= 0) { |
408 | printk(KERN_WARNING "%s: skb too small\n" , __func__); |
409 | return -EINVAL; |
410 | } |
411 | if (skb->len > ch->maxlen) { |
412 | printk(KERN_WARNING "%s: skb too large(%d/%d)\n" , |
413 | __func__, skb->len, ch->maxlen); |
414 | return -EINVAL; |
415 | } |
416 | /* HW lock must be obtained */ |
417 | if (test_and_set_bit(FLG_TX_BUSY, addr: &ch->Flags)) { |
418 | skb_queue_tail(list: &ch->squeue, newsk: skb); |
419 | return 0; |
420 | } else { |
421 | /* write to fifo */ |
422 | ch->tx_skb = skb; |
423 | ch->tx_idx = 0; |
424 | return 1; |
425 | } |
426 | } |
427 | EXPORT_SYMBOL(dchannel_senddata); |
428 | |
429 | int |
430 | bchannel_senddata(struct bchannel *ch, struct sk_buff *skb) |
431 | { |
432 | |
433 | /* check oversize */ |
434 | if (skb->len <= 0) { |
435 | printk(KERN_WARNING "%s: skb too small\n" , __func__); |
436 | return -EINVAL; |
437 | } |
438 | if (skb->len > ch->maxlen) { |
439 | printk(KERN_WARNING "%s: skb too large(%d/%d)\n" , |
440 | __func__, skb->len, ch->maxlen); |
441 | return -EINVAL; |
442 | } |
443 | /* HW lock must be obtained */ |
444 | /* check for pending next_skb */ |
445 | if (ch->next_skb) { |
446 | printk(KERN_WARNING |
447 | "%s: next_skb exist ERROR (skb->len=%d next_skb->len=%d)\n" , |
448 | __func__, skb->len, ch->next_skb->len); |
449 | return -EBUSY; |
450 | } |
451 | if (test_and_set_bit(FLG_TX_BUSY, addr: &ch->Flags)) { |
452 | test_and_set_bit(FLG_TX_NEXT, addr: &ch->Flags); |
453 | ch->next_skb = skb; |
454 | return 0; |
455 | } else { |
456 | /* write to fifo */ |
457 | ch->tx_skb = skb; |
458 | ch->tx_idx = 0; |
459 | confirm_Bsend(bch: ch); |
460 | return 1; |
461 | } |
462 | } |
463 | EXPORT_SYMBOL(bchannel_senddata); |
464 | |
465 | /* The function allocates a new receive skb on demand with a size for the |
466 | * requirements of the current protocol. It returns the tailroom of the |
467 | * receive skb or an error. |
468 | */ |
469 | int |
470 | bchannel_get_rxbuf(struct bchannel *bch, int reqlen) |
471 | { |
472 | int len; |
473 | |
474 | if (bch->rx_skb) { |
475 | len = skb_tailroom(skb: bch->rx_skb); |
476 | if (len < reqlen) { |
477 | pr_warn("B%d no space for %d (only %d) bytes\n" , |
478 | bch->nr, reqlen, len); |
479 | if (test_bit(FLG_TRANSPARENT, &bch->Flags)) { |
480 | /* send what we have now and try a new buffer */ |
481 | recv_Bchannel(bch, 0, true); |
482 | } else { |
483 | /* on HDLC we have to drop too big frames */ |
484 | return -EMSGSIZE; |
485 | } |
486 | } else { |
487 | return len; |
488 | } |
489 | } |
490 | /* update current min/max length first */ |
491 | if (unlikely(bch->maxlen != bch->next_maxlen)) |
492 | bch->maxlen = bch->next_maxlen; |
493 | if (unlikely(bch->minlen != bch->next_minlen)) |
494 | bch->minlen = bch->next_minlen; |
495 | if (unlikely(reqlen > bch->maxlen)) |
496 | return -EMSGSIZE; |
497 | if (test_bit(FLG_TRANSPARENT, &bch->Flags)) { |
498 | if (reqlen >= bch->minlen) { |
499 | len = reqlen; |
500 | } else { |
501 | len = 2 * bch->minlen; |
502 | if (len > bch->maxlen) |
503 | len = bch->maxlen; |
504 | } |
505 | } else { |
506 | /* with HDLC we do not know the length yet */ |
507 | len = bch->maxlen; |
508 | } |
509 | bch->rx_skb = mI_alloc_skb(len, GFP_ATOMIC); |
510 | if (!bch->rx_skb) { |
511 | pr_warn("B%d receive no memory for %d bytes\n" , bch->nr, len); |
512 | len = -ENOMEM; |
513 | } |
514 | return len; |
515 | } |
516 | EXPORT_SYMBOL(bchannel_get_rxbuf); |
517 | |