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_Bchannel(struct bchannel *bch)
 170 {
 171         struct mISDNhead *hh;
 172
 173         hh = mISDN_HEAD_P(bch->rx_skb);
 174         hh->prim = PH_DATA_IND;
 175         hh->id = MISDN_ID_ANY;
 176         if (bch->rcount >= 64) {
 177                 printk(KERN_WARNING "B-channel %p receive queue overflow, "
 178                         "fushing!\n", bch);
 179                 skb_queue_purge(&bch->rqueue);
 180                 bch->rcount = 0;
 181                 return;
 182         }
 183         bch->rcount++;
 184         skb_queue_tail(&bch->rqueue, bch->rx_skb);
 185         bch->rx_skb = NULL;
 186         schedule_event(bch, FLG_RECVQUEUE);
 187 }
 188 EXPORT_SYMBOL(recv_Bchannel);
 189
 190 void
 191 recv_Dchannel_skb(struct dchannel *dch, struct sk_buff *skb)
 192 {
 193         skb_queue_tail(&dch->rqueue, skb);
 194         schedule_event(dch, FLG_RECVQUEUE);
 195 }
 196 EXPORT_SYMBOL(recv_Dchannel_skb);
 197
 198 void
 199 recv_Bchannel_skb(struct bchannel *bch, struct sk_buff *skb)
 200 {
 201         if (bch->rcount >= 64) {
 202                 printk(KERN_WARNING "B-channel %p receive queue overflow, "
 203                         "fushing!\n", bch);
 204                 skb_queue_purge(&bch->rqueue);
 205                 bch->rcount = 0;
 206         }
 207         bch->rcount++;
 208         skb_queue_tail(&bch->rqueue, skb);
 209         schedule_event(bch, FLG_RECVQUEUE);
 210 }
 211 EXPORT_SYMBOL(recv_Bchannel_skb);
 212
 213 static void
 214 confirm_Dsend(struct dchannel *dch)
 215 {
 216         struct sk_buff  *skb;
 217
 218         skb = _alloc_mISDN_skb(PH_DATA_CNF, mISDN_HEAD_ID(dch->tx_skb),
 219             0, NULL, GFP_ATOMIC);
 220         if (!skb) {
 221                 printk(KERN_ERR "%s: no skb id %x\n", __func__,
 222                     mISDN_HEAD_ID(dch->tx_skb));
 223                 return;
 224         }
 225         skb_queue_tail(&dch->rqueue, skb);
 226         schedule_event(dch, FLG_RECVQUEUE);
 227 }
 228
 229 int
 230 get_next_dframe(struct dchannel *dch)
 231 {
 232         dch->tx_idx = 0;
 233         dch->tx_skb = skb_dequeue(&dch->squeue);
 234         if (dch->tx_skb) {
 235                 confirm_Dsend(dch);
 236                 return 1;
 237         }
 238         dch->tx_skb = NULL;
 239         test_and_clear_bit(FLG_TX_BUSY, &dch->Flags);
 240         return 0;
 241 }
 242 EXPORT_SYMBOL(get_next_dframe);
 243
 244 void
 245 confirm_Bsend(struct bchannel *bch)
 246 {
 247         struct sk_buff  *skb;
 248
 249         if (bch->rcount >= 64) {
 250                 printk(KERN_WARNING "B-channel %p receive queue overflow, "
 251                         "fushing!\n", bch);
 252                 skb_queue_purge(&bch->rqueue);
 253                 bch->rcount = 0;
 254         }
 255         skb = _alloc_mISDN_skb(PH_DATA_CNF, mISDN_HEAD_ID(bch->tx_skb),
 256             0, NULL, GFP_ATOMIC);
 257         if (!skb) {
 258                 printk(KERN_ERR "%s: no skb id %x\n", __func__,
 259                     mISDN_HEAD_ID(bch->tx_skb));
 260                 return;
 261         }
 262         bch->rcount++;
 263         skb_queue_tail(&bch->rqueue, skb);
 264         schedule_event(bch, FLG_RECVQUEUE);
 265 }
 266 EXPORT_SYMBOL(confirm_Bsend);
 267
 268 int
 269 get_next_bframe(struct bchannel *bch)
 270 {
 271         bch->tx_idx = 0;
 272         if (test_bit(FLG_TX_NEXT, &bch->Flags)) {
 273                 bch->tx_skb = bch->next_skb;
 274                 if (bch->tx_skb) {
 275                         bch->next_skb = NULL;
 276                         test_and_clear_bit(FLG_TX_NEXT, &bch->Flags);
 277                         if (!test_bit(FLG_TRANSPARENT, &bch->Flags))
 278                                 confirm_Bsend(bch); /* not for transparent */
 279                         return 1;
 280                 } else {
 281                         test_and_clear_bit(FLG_TX_NEXT, &bch->Flags);
 282                         printk(KERN_WARNING "B TX_NEXT without skb\n");
 283                 }
 284         }
 285         bch->tx_skb = NULL;
 286         test_and_clear_bit(FLG_TX_BUSY, &bch->Flags);
 287         return 0;
 288 }
 289 EXPORT_SYMBOL(get_next_bframe);
 290
 291 void
 292 queue_ch_frame(struct mISDNchannel *ch, u_int pr, int id, struct sk_buff *skb)
 293 {
 294         struct mISDNhead *hh;
 295
 296         if (!skb) {
 297                 _queue_data(ch, pr, id, 0, NULL, GFP_ATOMIC);
 298         } else {
 299                 if (ch->peer) {
 300                         hh = mISDN_HEAD_P(skb);
 301                         hh->prim = pr;
 302                         hh->id = id;
 303                         if (!ch->recv(ch->peer, skb))
 304                                 return;
 305                 }
 306                 dev_kfree_skb(skb);
 307         }
 308 }
 309 EXPORT_SYMBOL(queue_ch_frame);
 310
 311 int
 312 dchannel_senddata(struct dchannel *ch, struct sk_buff *skb)
 313 {
 314         /* check oversize */
 315         if (skb->len <= 0) {
 316                 printk(KERN_WARNING "%s: skb too small\n", __func__);
 317                 return -EINVAL;
 318         }
 319         if (skb->len > ch->maxlen) {
 320                 printk(KERN_WARNING "%s: skb too large(%d/%d)\n",
 321                         __func__, skb->len, ch->maxlen);
 322                 return -EINVAL;
 323         }
 324         /* HW lock must be obtained */
 325         if (test_and_set_bit(FLG_TX_BUSY, &ch->Flags)) {
 326                 skb_queue_tail(&ch->squeue, skb);
 327                 return 0;
 328         } else {
 329                 /* write to fifo */
 330                 ch->tx_skb = skb;
 331                 ch->tx_idx = 0;
 332                 return 1;
 333         }
 334 }
 335 EXPORT_SYMBOL(dchannel_senddata);
 336
 337 int
 338 bchannel_senddata(struct bchannel *ch, struct sk_buff *skb)
 339 {
 340
 341         /* check oversize */
 342         if (skb->len <= 0) {
 343                 printk(KERN_WARNING "%s: skb too small\n", __func__);
 344                 return -EINVAL;
 345         }
 346         if (skb->len > ch->maxlen) {
 347                 printk(KERN_WARNING "%s: skb too large(%d/%d)\n",
 348                         __func__, skb->len, ch->maxlen);
 349                 return -EINVAL;
 350         }
 351         /* HW lock must be obtained */
 352         /* check for pending next_skb */
 353         if (ch->next_skb) {
 354                 printk(KERN_WARNING
 355                     "%s: next_skb exist ERROR (skb->len=%d next_skb->len=%d)\n",
 356                     __func__, skb->len, ch->next_skb->len);
 357                 return -EBUSY;
 358         }
 359         if (test_and_set_bit(FLG_TX_BUSY, &ch->Flags)) {
 360                 test_and_set_bit(FLG_TX_NEXT, &ch->Flags);
 361                 ch->next_skb = skb;
 362                 return 0;
 363         } else {
 364                 /* write to fifo */
 365                 ch->tx_skb = skb;
 366                 ch->tx_idx = 0;
 367                 return 1;
 368         }
 369 }
 370 EXPORT_SYMBOL(bchannel_senddata);