drivers/isdn/mISDN/hwchannel.c

   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 void
 118 mISDN_clear_bchannel(struct bchannel *ch)
 119 {
 120         if (ch->tx_skb) {
 121                 dev_kfree_skb(ch->tx_skb);
 122                 ch->tx_skb = NULL;
 123         }
 124         ch->tx_idx = 0;
 125         if (ch->rx_skb) {
 126                 dev_kfree_skb(ch->rx_skb);
 127                 ch->rx_skb = NULL;
 128         }
 129         if (ch->next_skb) {
 130                 dev_kfree_skb(ch->next_skb);
 131                 ch->next_skb = NULL;
 132         }
 133         test_and_clear_bit(FLG_TX_BUSY, &ch->Flags);
 134         test_and_clear_bit(FLG_TX_NEXT, &ch->Flags);
 135         test_and_clear_bit(FLG_ACTIVE, &ch->Flags);
 136 }
 137 EXPORT_SYMBOL(mISDN_clear_bchannel);
 138
 139 int
 140 mISDN_freebchannel(struct bchannel *ch)
 141 {
 142         mISDN_clear_bchannel(ch);
 143         skb_queue_purge(&ch->rqueue);
 144         ch->rcount = 0;
 145         flush_scheduled_work();
 146         return 0;
 147 }
 148 EXPORT_SYMBOL(mISDN_freebchannel);
 149
 150 static inline u_int
 151 get_sapi_tei(u_char *p)
 152 {
 153         u_int   sapi, tei;
 154
 155         sapi = *p >> 2;
 156         tei = p[1] >> 1;
 157         return sapi | (tei << 8);
 158 }
 159
 160 void
 161 recv_Dchannel(struct dchannel *dch)
 162 {
 163         struct mISDNhead *hh;
 164
 165         if (dch->rx_skb->len < 2) { /* at least 2 for sapi / tei */
 166                 dev_kfree_skb(dch->rx_skb);
 167                 dch->rx_skb = NULL;
 168                 return;
 169         }
 170         hh = mISDN_HEAD_P(dch->rx_skb);
 171         hh->prim = PH_DATA_IND;
 172         hh->id = get_sapi_tei(dch->rx_skb->data);
 173         skb_queue_tail(&dch->rqueue, dch->rx_skb);
 174         dch->rx_skb = NULL;
 175         schedule_event(dch, FLG_RECVQUEUE);
 176 }
 177 EXPORT_SYMBOL(recv_Dchannel);
 178
 179 void
 180 recv_Echannel(struct dchannel *ech, struct dchannel *dch)
 181 {
 182         struct mISDNhead *hh;
 183
 184         if (ech->rx_skb->len < 2) { /* at least 2 for sapi / tei */
 185                 dev_kfree_skb(ech->rx_skb);
 186                 ech->rx_skb = NULL;
 187                 return;
 188         }
 189         hh = mISDN_HEAD_P(ech->rx_skb);
 190         hh->prim = PH_DATA_E_IND;
 191         hh->id = get_sapi_tei(ech->rx_skb->data);
 192         skb_queue_tail(&dch->rqueue, ech->rx_skb);
 193         ech->rx_skb = NULL;
 194         schedule_event(dch, FLG_RECVQUEUE);
 195 }
 196 EXPORT_SYMBOL(recv_Echannel);
 197
 198 void
 199 recv_Bchannel(struct bchannel *bch, unsigned int id)
 200 {
 201         struct mISDNhead *hh;
 202
 203         hh = mISDN_HEAD_P(bch->rx_skb);
 204         hh->prim = PH_DATA_IND;
 205         hh->id = id;
 206         if (bch->rcount >= 64) {
 207                 printk(KERN_WARNING "B-channel %p receive queue overflow, "
 208                         "fushing!\n", bch);
 209                 skb_queue_purge(&bch->rqueue);
 210                 bch->rcount = 0;
 211                 return;
 212         }
 213         bch->rcount++;
 214         skb_queue_tail(&bch->rqueue, bch->rx_skb);
 215         bch->rx_skb = NULL;
 216         schedule_event(bch, FLG_RECVQUEUE);
 217 }
 218 EXPORT_SYMBOL(recv_Bchannel);
 219
 220 void
 221 recv_Dchannel_skb(struct dchannel *dch, struct sk_buff *skb)
 222 {
 223         skb_queue_tail(&dch->rqueue, skb);
 224         schedule_event(dch, FLG_RECVQUEUE);
 225 }
 226 EXPORT_SYMBOL(recv_Dchannel_skb);
 227
 228 void
 229 recv_Bchannel_skb(struct bchannel *bch, struct sk_buff *skb)
 230 {
 231         if (bch->rcount >= 64) {
 232                 printk(KERN_WARNING "B-channel %p receive queue overflow, "
 233                         "fushing!\n", bch);
 234                 skb_queue_purge(&bch->rqueue);
 235                 bch->rcount = 0;
 236         }
 237         bch->rcount++;
 238         skb_queue_tail(&bch->rqueue, skb);
 239         schedule_event(bch, FLG_RECVQUEUE);
 240 }
 241 EXPORT_SYMBOL(recv_Bchannel_skb);
 242
 243 static void
 244 confirm_Dsend(struct dchannel *dch)
 245 {
 246         struct sk_buff  *skb;
 247
 248         skb = _alloc_mISDN_skb(PH_DATA_CNF, mISDN_HEAD_ID(dch->tx_skb),
 249             0, NULL, GFP_ATOMIC);
 250         if (!skb) {
 251                 printk(KERN_ERR "%s: no skb id %x\n", __func__,
 252                     mISDN_HEAD_ID(dch->tx_skb));
 253                 return;
 254         }
 255         skb_queue_tail(&dch->rqueue, skb);
 256         schedule_event(dch, FLG_RECVQUEUE);
 257 }
 258
 259 int
 260 get_next_dframe(struct dchannel *dch)
 261 {
 262         dch->tx_idx = 0;
 263         dch->tx_skb = skb_dequeue(&dch->squeue);
 264         if (dch->tx_skb) {
 265                 confirm_Dsend(dch);
 266                 return 1;
 267         }
 268         dch->tx_skb = NULL;
 269         test_and_clear_bit(FLG_TX_BUSY, &dch->Flags);
 270         return 0;
 271 }
 272 EXPORT_SYMBOL(get_next_dframe);
 273
 274 void
 275 confirm_Bsend(struct bchannel *bch)
 276 {
 277         struct sk_buff  *skb;
 278
 279         if (bch->rcount >= 64) {
 280                 printk(KERN_WARNING "B-channel %p receive queue overflow, "
 281                         "fushing!\n", bch);
 282                 skb_queue_purge(&bch->rqueue);
 283                 bch->rcount = 0;
 284         }
 285         skb = _alloc_mISDN_skb(PH_DATA_CNF, mISDN_HEAD_ID(bch->tx_skb),
 286             0, NULL, GFP_ATOMIC);
 287         if (!skb) {
 288                 printk(KERN_ERR "%s: no skb id %x\n", __func__,
 289                     mISDN_HEAD_ID(bch->tx_skb));
 290                 return;
 291         }
 292         bch->rcount++;
 293         skb_queue_tail(&bch->rqueue, skb);
 294         schedule_event(bch, FLG_RECVQUEUE);
 295 }
 296 EXPORT_SYMBOL(confirm_Bsend);
 297
 298 int
 299 get_next_bframe(struct bchannel *bch)
 300 {
 301         bch->tx_idx = 0;
 302         if (test_bit(FLG_TX_NEXT, &bch->Flags)) {
 303                 bch->tx_skb = bch->next_skb;
 304                 if (bch->tx_skb) {
 305                         bch->next_skb = NULL;
 306                         test_and_clear_bit(FLG_TX_NEXT, &bch->Flags);
 307                         if (!test_bit(FLG_TRANSPARENT, &bch->Flags))
 308                                 confirm_Bsend(bch); /* not for transparent */
 309                         return 1;
 310                 } else {
 311                         test_and_clear_bit(FLG_TX_NEXT, &bch->Flags);
 312                         printk(KERN_WARNING "B TX_NEXT without skb\n");
 313                 }
 314         }
 315         bch->tx_skb = NULL;
 316         test_and_clear_bit(FLG_TX_BUSY, &bch->Flags);
 317         return 0;
 318 }
 319 EXPORT_SYMBOL(get_next_bframe);
 320
 321 void
 322 queue_ch_frame(struct mISDNchannel *ch, u_int pr, int id, struct sk_buff *skb)
 323 {
 324         struct mISDNhead *hh;
 325
 326         if (!skb) {
 327                 _queue_data(ch, pr, id, 0, NULL, GFP_ATOMIC);
 328         } else {
 329                 if (ch->peer) {
 330                         hh = mISDN_HEAD_P(skb);
 331                         hh->prim = pr;
 332                         hh->id = id;
 333                         if (!ch->recv(ch->peer, skb))
 334                                 return;
 335                 }
 336                 dev_kfree_skb(skb);
 337         }
 338 }
 339 EXPORT_SYMBOL(queue_ch_frame);
 340
 341 int
 342 dchannel_senddata(struct dchannel *ch, struct sk_buff *skb)
 343 {
 344         /* check oversize */
 345         if (skb->len <= 0) {
 346                 printk(KERN_WARNING "%s: skb too small\n", __func__);
 347                 return -EINVAL;
 348         }
 349         if (skb->len > ch->maxlen) {
 350                 printk(KERN_WARNING "%s: skb too large(%d/%d)\n",
 351                         __func__, skb->len, ch->maxlen);
 352                 return -EINVAL;
 353         }
 354         /* HW lock must be obtained */
 355         if (test_and_set_bit(FLG_TX_BUSY, &ch->Flags)) {
 356                 skb_queue_tail(&ch->squeue, skb);
 357                 return 0;
 358         } else {
 359                 /* write to fifo */
 360                 ch->tx_skb = skb;
 361                 ch->tx_idx = 0;
 362                 return 1;
 363         }
 364 }
 365 EXPORT_SYMBOL(dchannel_senddata);
 366
 367 int
 368 bchannel_senddata(struct bchannel *ch, struct sk_buff *skb)
 369 {
 370
 371         /* check oversize */
 372         if (skb->len <= 0) {
 373                 printk(KERN_WARNING "%s: skb too small\n", __func__);
 374                 return -EINVAL;
 375         }
 376         if (skb->len > ch->maxlen) {
 377                 printk(KERN_WARNING "%s: skb too large(%d/%d)\n",
 378                         __func__, skb->len, ch->maxlen);
 379                 return -EINVAL;
 380         }
 381         /* HW lock must be obtained */
 382         /* check for pending next_skb */
 383         if (ch->next_skb) {
 384                 printk(KERN_WARNING
 385                     "%s: next_skb exist ERROR (skb->len=%d next_skb->len=%d)\n",
 386                     __func__, skb->len, ch->next_skb->len);
 387                 return -EBUSY;
 388         }
 389         if (test_and_set_bit(FLG_TX_BUSY, &ch->Flags)) {
 390                 test_and_set_bit(FLG_TX_NEXT, &ch->Flags);
 391                 ch->next_skb = skb;
 392                 return 0;
 393         } else {
 394                 /* write to fifo */
 395                 ch->tx_skb = skb;
 396                 ch->tx_idx = 0;
 397                 return 1;
 398         }
 399 }
 400 EXPORT_SYMBOL(bchannel_senddata);