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/gfp.h>
  19 #include <linux/module.h>
  20 #include <linux/mISDNhw.h>
  21
  22 static void
  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
  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
  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
  84 mISDN_initbchannel(struct bchannel *ch, int maxlen)
  85 {
  86         ch->Flags = 0;
  87         ch->maxlen = maxlen;
  88         ch->hw = NULL;
  89         ch->rx_skb = NULL;
  90         ch->tx_skb = NULL;
  91         ch->tx_idx = 0;
  92         skb_queue_head_init(&ch->rqueue);
  93         ch->rcount = 0;
  94         ch->next_skb = NULL;
  95         INIT_WORK(&ch->workq, bchannel_bh);
  96         return 0;
  97 }
  98 EXPORT_SYMBOL(mISDN_initbchannel);
  99
 100 int
 101 mISDN_freedchannel(struct dchannel *ch)
 102 {
 103         if (ch->tx_skb) {
 104                 dev_kfree_skb(ch->tx_skb);
 105                 ch->tx_skb = NULL;
 106         }
 107         if (ch->rx_skb) {
 108                 dev_kfree_skb(ch->rx_skb);
 109                 ch->rx_skb = NULL;
 110         }
 111         skb_queue_purge(&ch->squeue);
 112         skb_queue_purge(&ch->rqueue);
 113         flush_work_sync(&ch->workq);
 114         return 0;
 115 }
 116 EXPORT_SYMBOL(mISDN_freedchannel);
 117
 118 void
 119 mISDN_clear_bchannel(struct bchannel *ch)
 120 {
 121         if (ch->tx_skb) {
 122                 dev_kfree_skb(ch->tx_skb);
 123                 ch->tx_skb = NULL;
 124         }
 125         ch->tx_idx = 0;
 126         if (ch->rx_skb) {
 127                 dev_kfree_skb(ch->rx_skb);
 128                 ch->rx_skb = NULL;
 129         }
 130         if (ch->next_skb) {
 131                 dev_kfree_skb(ch->next_skb);
 132                 ch->next_skb = NULL;
 133         }
 134         test_and_clear_bit(FLG_TX_BUSY, &ch->Flags);
 135         test_and_clear_bit(FLG_TX_NEXT, &ch->Flags);
 136         test_and_clear_bit(FLG_ACTIVE, &ch->Flags);
 137 }
 138 EXPORT_SYMBOL(mISDN_clear_bchannel);
 139
 140 int
 141 mISDN_freebchannel(struct bchannel *ch)
 142 {
 143         mISDN_clear_bchannel(ch);
 144         skb_queue_purge(&ch->rqueue);
 145         ch->rcount = 0;
 146         flush_work_sync(&ch->workq);
 147         return 0;
 148 }
 149 EXPORT_SYMBOL(mISDN_freebchannel);
 150
 151 static inline u_int
 152 get_sapi_tei(u_char *p)
 153 {
 154         u_int   sapi, tei;
 155
 156         sapi = *p >> 2;
 157         tei = p[1] >> 1;
 158         return sapi | (tei << 8);
 159 }
 160
 161 void
 162 recv_Dchannel(struct dchannel *dch)
 163 {
 164         struct mISDNhead *hh;
 165
 166         if (dch->rx_skb->len < 2) { /* at least 2 for sapi / tei */
 167                 dev_kfree_skb(dch->rx_skb);
 168                 dch->rx_skb = NULL;
 169                 return;
 170         }
 171         hh = mISDN_HEAD_P(dch->rx_skb);
 172         hh->prim = PH_DATA_IND;
 173         hh->id = get_sapi_tei(dch->rx_skb->data);
 174         skb_queue_tail(&dch->rqueue, dch->rx_skb);
 175         dch->rx_skb = NULL;
 176         schedule_event(dch, FLG_RECVQUEUE);
 177 }
 178 EXPORT_SYMBOL(recv_Dchannel);
 179
 180 void
 181 recv_Echannel(struct dchannel *ech, struct dchannel *dch)
 182 {
 183         struct mISDNhead *hh;
 184
 185         if (ech->rx_skb->len < 2) { /* at least 2 for sapi / tei */
 186                 dev_kfree_skb(ech->rx_skb);
 187                 ech->rx_skb = NULL;
 188                 return;
 189         }
 190         hh = mISDN_HEAD_P(ech->rx_skb);
 191         hh->prim = PH_DATA_E_IND;
 192         hh->id = get_sapi_tei(ech->rx_skb->data);
 193         skb_queue_tail(&dch->rqueue, ech->rx_skb);
 194         ech->rx_skb = NULL;
 195         schedule_event(dch, FLG_RECVQUEUE);
 196 }
 197 EXPORT_SYMBOL(recv_Echannel);
 198
 199 void
 200 recv_Bchannel(struct bchannel *bch, unsigned int id)
 201 {
 202         struct mISDNhead *hh;
 203
 204         hh = mISDN_HEAD_P(bch->rx_skb);
 205         hh->prim = PH_DATA_IND;
 206         hh->id = id;
 207         if (bch->rcount >= 64) {
 208                 printk(KERN_WARNING "B-channel %p receive queue overflow, "
 209                         "flushing!\n", bch);
 210                 skb_queue_purge(&bch->rqueue);
 211                 bch->rcount = 0;
 212                 return;
 213         }
 214         bch->rcount++;
 215         skb_queue_tail(&bch->rqueue, bch->rx_skb);
 216         bch->rx_skb = NULL;
 217         schedule_event(bch, FLG_RECVQUEUE);
 218 }
 219 EXPORT_SYMBOL(recv_Bchannel);
 220
 221 void
 222 recv_Dchannel_skb(struct dchannel *dch, struct sk_buff *skb)
 223 {
 224         skb_queue_tail(&dch->rqueue, skb);
 225         schedule_event(dch, FLG_RECVQUEUE);
 226 }
 227 EXPORT_SYMBOL(recv_Dchannel_skb);
 228
 229 void
 230 recv_Bchannel_skb(struct bchannel *bch, struct sk_buff *skb)
 231 {
 232         if (bch->rcount >= 64) {
 233                 printk(KERN_WARNING "B-channel %p receive queue overflow, "
 234                         "flushing!\n", bch);
 235                 skb_queue_purge(&bch->rqueue);
 236                 bch->rcount = 0;
 237         }
 238         bch->rcount++;
 239         skb_queue_tail(&bch->rqueue, skb);
 240         schedule_event(bch, FLG_RECVQUEUE);
 241 }
 242 EXPORT_SYMBOL(recv_Bchannel_skb);
 243
 244 static void
 245 confirm_Dsend(struct dchannel *dch)
 246 {
 247         struct sk_buff  *skb;
 248
 249         skb = _alloc_mISDN_skb(PH_DATA_CNF, mISDN_HEAD_ID(dch->tx_skb),
 250             0, NULL, GFP_ATOMIC);
 251         if (!skb) {
 252                 printk(KERN_ERR "%s: no skb id %x\n", __func__,
 253                     mISDN_HEAD_ID(dch->tx_skb));
 254                 return;
 255         }
 256         skb_queue_tail(&dch->rqueue, skb);
 257         schedule_event(dch, FLG_RECVQUEUE);
 258 }
 259
 260 int
 261 get_next_dframe(struct dchannel *dch)
 262 {
 263         dch->tx_idx = 0;
 264         dch->tx_skb = skb_dequeue(&dch->squeue);
 265         if (dch->tx_skb) {
 266                 confirm_Dsend(dch);
 267                 return 1;
 268         }
 269         dch->tx_skb = NULL;
 270         test_and_clear_bit(FLG_TX_BUSY, &dch->Flags);
 271         return 0;
 272 }
 273 EXPORT_SYMBOL(get_next_dframe);
 274
 275 void
 276 confirm_Bsend(struct bchannel *bch)
 277 {
 278         struct sk_buff  *skb;
 279
 280         if (bch->rcount >= 64) {
 281                 printk(KERN_WARNING "B-channel %p receive queue overflow, "
 282                         "flushing!\n", bch);
 283                 skb_queue_purge(&bch->rqueue);
 284                 bch->rcount = 0;
 285         }
 286         skb = _alloc_mISDN_skb(PH_DATA_CNF, mISDN_HEAD_ID(bch->tx_skb),
 287             0, NULL, GFP_ATOMIC);
 288         if (!skb) {
 289                 printk(KERN_ERR "%s: no skb id %x\n", __func__,
 290                     mISDN_HEAD_ID(bch->tx_skb));
 291                 return;
 292         }
 293         bch->rcount++;
 294         skb_queue_tail(&bch->rqueue, skb);
 295         schedule_event(bch, FLG_RECVQUEUE);
 296 }
 297 EXPORT_SYMBOL(confirm_Bsend);
 298
 299 int
 300 get_next_bframe(struct bchannel *bch)
 301 {
 302         bch->tx_idx = 0;
 303         if (test_bit(FLG_TX_NEXT, &bch->Flags)) {
 304                 bch->tx_skb = bch->next_skb;
 305                 if (bch->tx_skb) {
 306                         bch->next_skb = NULL;
 307                         test_and_clear_bit(FLG_TX_NEXT, &bch->Flags);
 308                         if (!test_bit(FLG_TRANSPARENT, &bch->Flags))
 309                                 confirm_Bsend(bch); /* not for transparent */
 310                         return 1;
 311                 } else {
 312                         test_and_clear_bit(FLG_TX_NEXT, &bch->Flags);
 313                         printk(KERN_WARNING "B TX_NEXT without skb\n");
 314                 }
 315         }
 316         bch->tx_skb = NULL;
 317         test_and_clear_bit(FLG_TX_BUSY, &bch->Flags);
 318         return 0;
 319 }
 320 EXPORT_SYMBOL(get_next_bframe);
 321
 322 void
 323 queue_ch_frame(struct mISDNchannel *ch, u_int pr, int id, struct sk_buff *skb)
 324 {
 325         struct mISDNhead *hh;
 326
 327         if (!skb) {
 328                 _queue_data(ch, pr, id, 0, NULL, GFP_ATOMIC);
 329         } else {
 330                 if (ch->peer) {
 331                         hh = mISDN_HEAD_P(skb);
 332                         hh->prim = pr;
 333                         hh->id = id;
 334                         if (!ch->recv(ch->peer, skb))
 335                                 return;
 336                 }
 337                 dev_kfree_skb(skb);
 338         }
 339 }
 340 EXPORT_SYMBOL(queue_ch_frame);
 341
 342 int
 343 dchannel_senddata(struct dchannel *ch, struct sk_buff *skb)
 344 {
 345         /* check oversize */
 346         if (skb->len <= 0) {
 347                 printk(KERN_WARNING "%s: skb too small\n", __func__);
 348                 return -EINVAL;
 349         }
 350         if (skb->len > ch->maxlen) {
 351                 printk(KERN_WARNING "%s: skb too large(%d/%d)\n",
 352                         __func__, skb->len, ch->maxlen);
 353                 return -EINVAL;
 354         }
 355         /* HW lock must be obtained */
 356         if (test_and_set_bit(FLG_TX_BUSY, &ch->Flags)) {
 357                 skb_queue_tail(&ch->squeue, skb);
 358                 return 0;
 359         } else {
 360                 /* write to fifo */
 361                 ch->tx_skb = skb;
 362                 ch->tx_idx = 0;
 363                 return 1;
 364         }
 365 }
 366 EXPORT_SYMBOL(dchannel_senddata);
 367
 368 int
 369 bchannel_senddata(struct bchannel *ch, struct sk_buff *skb)
 370 {
 371
 372         /* check oversize */
 373         if (skb->len <= 0) {
 374                 printk(KERN_WARNING "%s: skb too small\n", __func__);
 375                 return -EINVAL;
 376         }
 377         if (skb->len > ch->maxlen) {
 378                 printk(KERN_WARNING "%s: skb too large(%d/%d)\n",
 379                         __func__, skb->len, ch->maxlen);
 380                 return -EINVAL;
 381         }
 382         /* HW lock must be obtained */
 383         /* check for pending next_skb */
 384         if (ch->next_skb) {
 385                 printk(KERN_WARNING
 386                     "%s: next_skb exist ERROR (skb->len=%d next_skb->len=%d)\n",
 387                     __func__, skb->len, ch->next_skb->len);
 388                 return -EBUSY;
 389         }
 390         if (test_and_set_bit(FLG_TX_BUSY, &ch->Flags)) {
 391                 test_and_set_bit(FLG_TX_NEXT, &ch->Flags);
 392                 ch->next_skb = skb;
 393                 return 0;
 394         } else {
 395                 /* write to fifo */
 396                 ch->tx_skb = skb;
 397                 ch->tx_idx = 0;
 398                 return 1;
 399         }
 400 }
 401 EXPORT_SYMBOL(bchannel_senddata);