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 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);