![Karsten Keil](/assets/img/avatar_default.png)
MISDN_CTRL_RX_OFF is a meachanism to discard RX data in the driver if the data is not needed by the application. It can be used when playing mesages, but not recording or with unidirectional protocols. Signed-off-by: Karsten Keil <kkeil@linux-pingi.de> Signed-off-by: David S. Miller <davem@davemloft.net>
528 lines
12 KiB
C
528 lines
12 KiB
C
/*
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*
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* Author Karsten Keil <kkeil@novell.com>
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*
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* Copyright 2008 by Karsten Keil <kkeil@novell.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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*/
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#include <linux/gfp.h>
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#include <linux/module.h>
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#include <linux/mISDNhw.h>
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static void
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dchannel_bh(struct work_struct *ws)
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{
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struct dchannel *dch = container_of(ws, struct dchannel, workq);
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struct sk_buff *skb;
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int err;
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if (test_and_clear_bit(FLG_RECVQUEUE, &dch->Flags)) {
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while ((skb = skb_dequeue(&dch->rqueue))) {
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if (likely(dch->dev.D.peer)) {
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err = dch->dev.D.recv(dch->dev.D.peer, skb);
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if (err)
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dev_kfree_skb(skb);
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} else
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dev_kfree_skb(skb);
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}
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}
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if (test_and_clear_bit(FLG_PHCHANGE, &dch->Flags)) {
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if (dch->phfunc)
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dch->phfunc(dch);
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}
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}
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static void
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bchannel_bh(struct work_struct *ws)
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{
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struct bchannel *bch = container_of(ws, struct bchannel, workq);
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struct sk_buff *skb;
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int err;
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if (test_and_clear_bit(FLG_RECVQUEUE, &bch->Flags)) {
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while ((skb = skb_dequeue(&bch->rqueue))) {
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bch->rcount--;
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if (likely(bch->ch.peer)) {
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err = bch->ch.recv(bch->ch.peer, skb);
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if (err)
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dev_kfree_skb(skb);
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} else
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dev_kfree_skb(skb);
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}
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}
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}
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int
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mISDN_initdchannel(struct dchannel *ch, int maxlen, void *phf)
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{
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test_and_set_bit(FLG_HDLC, &ch->Flags);
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ch->maxlen = maxlen;
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ch->hw = NULL;
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ch->rx_skb = NULL;
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ch->tx_skb = NULL;
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ch->tx_idx = 0;
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ch->phfunc = phf;
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skb_queue_head_init(&ch->squeue);
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skb_queue_head_init(&ch->rqueue);
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INIT_LIST_HEAD(&ch->dev.bchannels);
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INIT_WORK(&ch->workq, dchannel_bh);
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return 0;
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}
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EXPORT_SYMBOL(mISDN_initdchannel);
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int
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mISDN_initbchannel(struct bchannel *ch, unsigned short maxlen,
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unsigned short minlen)
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{
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ch->Flags = 0;
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ch->minlen = minlen;
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ch->next_minlen = minlen;
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ch->init_minlen = minlen;
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ch->maxlen = maxlen;
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ch->next_maxlen = maxlen;
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ch->init_maxlen = maxlen;
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ch->hw = NULL;
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ch->rx_skb = NULL;
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ch->tx_skb = NULL;
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ch->tx_idx = 0;
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skb_queue_head_init(&ch->rqueue);
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ch->rcount = 0;
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ch->next_skb = NULL;
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INIT_WORK(&ch->workq, bchannel_bh);
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return 0;
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}
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EXPORT_SYMBOL(mISDN_initbchannel);
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int
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mISDN_freedchannel(struct dchannel *ch)
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{
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if (ch->tx_skb) {
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dev_kfree_skb(ch->tx_skb);
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ch->tx_skb = NULL;
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}
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if (ch->rx_skb) {
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dev_kfree_skb(ch->rx_skb);
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ch->rx_skb = NULL;
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}
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skb_queue_purge(&ch->squeue);
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skb_queue_purge(&ch->rqueue);
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flush_work_sync(&ch->workq);
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return 0;
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}
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EXPORT_SYMBOL(mISDN_freedchannel);
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void
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mISDN_clear_bchannel(struct bchannel *ch)
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{
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if (ch->tx_skb) {
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dev_kfree_skb(ch->tx_skb);
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ch->tx_skb = NULL;
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}
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ch->tx_idx = 0;
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if (ch->rx_skb) {
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dev_kfree_skb(ch->rx_skb);
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ch->rx_skb = NULL;
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}
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if (ch->next_skb) {
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dev_kfree_skb(ch->next_skb);
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ch->next_skb = NULL;
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}
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test_and_clear_bit(FLG_TX_BUSY, &ch->Flags);
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test_and_clear_bit(FLG_TX_NEXT, &ch->Flags);
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test_and_clear_bit(FLG_ACTIVE, &ch->Flags);
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test_and_clear_bit(FLG_FILLEMPTY, &ch->Flags);
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test_and_clear_bit(FLG_TX_EMPTY, &ch->Flags);
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test_and_clear_bit(FLG_RX_OFF, &ch->Flags);
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ch->dropcnt = 0;
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ch->minlen = ch->init_minlen;
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ch->next_minlen = ch->init_minlen;
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ch->maxlen = ch->init_maxlen;
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ch->next_maxlen = ch->init_maxlen;
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}
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EXPORT_SYMBOL(mISDN_clear_bchannel);
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int
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mISDN_freebchannel(struct bchannel *ch)
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{
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mISDN_clear_bchannel(ch);
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skb_queue_purge(&ch->rqueue);
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ch->rcount = 0;
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flush_work_sync(&ch->workq);
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return 0;
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}
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EXPORT_SYMBOL(mISDN_freebchannel);
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int
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mISDN_ctrl_bchannel(struct bchannel *bch, struct mISDN_ctrl_req *cq)
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{
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int ret = 0;
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switch (cq->op) {
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case MISDN_CTRL_GETOP:
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cq->op = MISDN_CTRL_RX_BUFFER | MISDN_CTRL_FILL_EMPTY |
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MISDN_CTRL_RX_OFF;
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break;
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case MISDN_CTRL_FILL_EMPTY:
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if (cq->p1) {
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memset(bch->fill, cq->p2 & 0xff, MISDN_BCH_FILL_SIZE);
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test_and_set_bit(FLG_FILLEMPTY, &bch->Flags);
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} else {
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test_and_clear_bit(FLG_FILLEMPTY, &bch->Flags);
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}
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break;
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case MISDN_CTRL_RX_OFF:
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/* read back dropped byte count */
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cq->p2 = bch->dropcnt;
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if (cq->p1)
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test_and_set_bit(FLG_RX_OFF, &bch->Flags);
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else
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test_and_clear_bit(FLG_RX_OFF, &bch->Flags);
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bch->dropcnt = 0;
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break;
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case MISDN_CTRL_RX_BUFFER:
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if (cq->p2 > MISDN_CTRL_RX_SIZE_IGNORE)
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bch->next_maxlen = cq->p2;
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if (cq->p1 > MISDN_CTRL_RX_SIZE_IGNORE)
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bch->next_minlen = cq->p1;
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/* we return the old values */
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cq->p1 = bch->minlen;
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cq->p2 = bch->maxlen;
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break;
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default:
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pr_info("mISDN unhandled control %x operation\n", cq->op);
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ret = -EINVAL;
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break;
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}
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return ret;
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}
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EXPORT_SYMBOL(mISDN_ctrl_bchannel);
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static inline u_int
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get_sapi_tei(u_char *p)
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{
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u_int sapi, tei;
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sapi = *p >> 2;
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tei = p[1] >> 1;
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return sapi | (tei << 8);
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}
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void
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recv_Dchannel(struct dchannel *dch)
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{
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struct mISDNhead *hh;
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if (dch->rx_skb->len < 2) { /* at least 2 for sapi / tei */
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dev_kfree_skb(dch->rx_skb);
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dch->rx_skb = NULL;
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return;
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}
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hh = mISDN_HEAD_P(dch->rx_skb);
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hh->prim = PH_DATA_IND;
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hh->id = get_sapi_tei(dch->rx_skb->data);
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skb_queue_tail(&dch->rqueue, dch->rx_skb);
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dch->rx_skb = NULL;
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schedule_event(dch, FLG_RECVQUEUE);
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}
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EXPORT_SYMBOL(recv_Dchannel);
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void
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recv_Echannel(struct dchannel *ech, struct dchannel *dch)
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{
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struct mISDNhead *hh;
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if (ech->rx_skb->len < 2) { /* at least 2 for sapi / tei */
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dev_kfree_skb(ech->rx_skb);
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ech->rx_skb = NULL;
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return;
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}
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hh = mISDN_HEAD_P(ech->rx_skb);
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hh->prim = PH_DATA_E_IND;
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hh->id = get_sapi_tei(ech->rx_skb->data);
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skb_queue_tail(&dch->rqueue, ech->rx_skb);
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ech->rx_skb = NULL;
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schedule_event(dch, FLG_RECVQUEUE);
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}
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EXPORT_SYMBOL(recv_Echannel);
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void
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recv_Bchannel(struct bchannel *bch, unsigned int id, bool force)
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{
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struct mISDNhead *hh;
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/* if allocation did fail upper functions still may call us */
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if (unlikely(!bch->rx_skb))
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return;
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if (unlikely(!bch->rx_skb->len)) {
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/* we have no data to send - this may happen after recovery
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* from overflow or too small allocation.
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* We need to free the buffer here */
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dev_kfree_skb(bch->rx_skb);
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bch->rx_skb = NULL;
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} else {
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if (test_bit(FLG_TRANSPARENT, &bch->Flags) &&
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(bch->rx_skb->len < bch->minlen) && !force)
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return;
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hh = mISDN_HEAD_P(bch->rx_skb);
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hh->prim = PH_DATA_IND;
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hh->id = id;
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if (bch->rcount >= 64) {
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printk(KERN_WARNING
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"B%d receive queue overflow - flushing!\n",
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bch->nr);
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skb_queue_purge(&bch->rqueue);
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}
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bch->rcount++;
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skb_queue_tail(&bch->rqueue, bch->rx_skb);
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bch->rx_skb = NULL;
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schedule_event(bch, FLG_RECVQUEUE);
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}
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}
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EXPORT_SYMBOL(recv_Bchannel);
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void
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recv_Dchannel_skb(struct dchannel *dch, struct sk_buff *skb)
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{
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skb_queue_tail(&dch->rqueue, skb);
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schedule_event(dch, FLG_RECVQUEUE);
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}
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EXPORT_SYMBOL(recv_Dchannel_skb);
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void
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recv_Bchannel_skb(struct bchannel *bch, struct sk_buff *skb)
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{
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if (bch->rcount >= 64) {
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printk(KERN_WARNING "B-channel %p receive queue overflow, "
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"flushing!\n", bch);
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skb_queue_purge(&bch->rqueue);
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bch->rcount = 0;
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}
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bch->rcount++;
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skb_queue_tail(&bch->rqueue, skb);
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schedule_event(bch, FLG_RECVQUEUE);
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}
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EXPORT_SYMBOL(recv_Bchannel_skb);
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static void
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confirm_Dsend(struct dchannel *dch)
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{
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struct sk_buff *skb;
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skb = _alloc_mISDN_skb(PH_DATA_CNF, mISDN_HEAD_ID(dch->tx_skb),
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0, NULL, GFP_ATOMIC);
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if (!skb) {
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printk(KERN_ERR "%s: no skb id %x\n", __func__,
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mISDN_HEAD_ID(dch->tx_skb));
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return;
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}
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skb_queue_tail(&dch->rqueue, skb);
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schedule_event(dch, FLG_RECVQUEUE);
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}
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int
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get_next_dframe(struct dchannel *dch)
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{
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dch->tx_idx = 0;
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dch->tx_skb = skb_dequeue(&dch->squeue);
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if (dch->tx_skb) {
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confirm_Dsend(dch);
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return 1;
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}
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dch->tx_skb = NULL;
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test_and_clear_bit(FLG_TX_BUSY, &dch->Flags);
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return 0;
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}
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EXPORT_SYMBOL(get_next_dframe);
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static void
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confirm_Bsend(struct bchannel *bch)
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{
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struct sk_buff *skb;
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if (bch->rcount >= 64) {
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printk(KERN_WARNING "B-channel %p receive queue overflow, "
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"flushing!\n", bch);
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skb_queue_purge(&bch->rqueue);
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bch->rcount = 0;
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}
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skb = _alloc_mISDN_skb(PH_DATA_CNF, mISDN_HEAD_ID(bch->tx_skb),
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0, NULL, GFP_ATOMIC);
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if (!skb) {
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printk(KERN_ERR "%s: no skb id %x\n", __func__,
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mISDN_HEAD_ID(bch->tx_skb));
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return;
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}
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bch->rcount++;
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skb_queue_tail(&bch->rqueue, skb);
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schedule_event(bch, FLG_RECVQUEUE);
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}
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int
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get_next_bframe(struct bchannel *bch)
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{
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bch->tx_idx = 0;
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if (test_bit(FLG_TX_NEXT, &bch->Flags)) {
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bch->tx_skb = bch->next_skb;
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if (bch->tx_skb) {
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bch->next_skb = NULL;
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test_and_clear_bit(FLG_TX_NEXT, &bch->Flags);
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/* confirm imediately to allow next data */
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confirm_Bsend(bch);
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return 1;
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} else {
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test_and_clear_bit(FLG_TX_NEXT, &bch->Flags);
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printk(KERN_WARNING "B TX_NEXT without skb\n");
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}
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}
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bch->tx_skb = NULL;
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test_and_clear_bit(FLG_TX_BUSY, &bch->Flags);
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return 0;
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}
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EXPORT_SYMBOL(get_next_bframe);
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void
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queue_ch_frame(struct mISDNchannel *ch, u_int pr, int id, struct sk_buff *skb)
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{
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struct mISDNhead *hh;
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if (!skb) {
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_queue_data(ch, pr, id, 0, NULL, GFP_ATOMIC);
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} else {
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if (ch->peer) {
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hh = mISDN_HEAD_P(skb);
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hh->prim = pr;
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hh->id = id;
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if (!ch->recv(ch->peer, skb))
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return;
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}
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dev_kfree_skb(skb);
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}
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}
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EXPORT_SYMBOL(queue_ch_frame);
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int
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dchannel_senddata(struct dchannel *ch, struct sk_buff *skb)
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{
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/* check oversize */
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if (skb->len <= 0) {
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printk(KERN_WARNING "%s: skb too small\n", __func__);
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return -EINVAL;
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}
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if (skb->len > ch->maxlen) {
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printk(KERN_WARNING "%s: skb too large(%d/%d)\n",
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__func__, skb->len, ch->maxlen);
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return -EINVAL;
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}
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/* HW lock must be obtained */
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if (test_and_set_bit(FLG_TX_BUSY, &ch->Flags)) {
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skb_queue_tail(&ch->squeue, skb);
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return 0;
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} else {
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/* write to fifo */
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ch->tx_skb = skb;
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ch->tx_idx = 0;
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return 1;
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}
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}
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EXPORT_SYMBOL(dchannel_senddata);
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int
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bchannel_senddata(struct bchannel *ch, struct sk_buff *skb)
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{
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/* check oversize */
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if (skb->len <= 0) {
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printk(KERN_WARNING "%s: skb too small\n", __func__);
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return -EINVAL;
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}
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if (skb->len > ch->maxlen) {
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printk(KERN_WARNING "%s: skb too large(%d/%d)\n",
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__func__, skb->len, ch->maxlen);
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return -EINVAL;
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}
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/* HW lock must be obtained */
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/* check for pending next_skb */
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if (ch->next_skb) {
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printk(KERN_WARNING
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"%s: next_skb exist ERROR (skb->len=%d next_skb->len=%d)\n",
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__func__, skb->len, ch->next_skb->len);
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return -EBUSY;
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}
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if (test_and_set_bit(FLG_TX_BUSY, &ch->Flags)) {
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test_and_set_bit(FLG_TX_NEXT, &ch->Flags);
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ch->next_skb = skb;
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return 0;
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} else {
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/* write to fifo */
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ch->tx_skb = skb;
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ch->tx_idx = 0;
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confirm_Bsend(ch);
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return 1;
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}
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}
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EXPORT_SYMBOL(bchannel_senddata);
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/* The function allocates a new receive skb on demand with a size for the
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* requirements of the current protocol. It returns the tailroom of the
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* receive skb or an error.
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*/
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int
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bchannel_get_rxbuf(struct bchannel *bch, int reqlen)
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{
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int len;
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if (bch->rx_skb) {
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len = skb_tailroom(bch->rx_skb);
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if (len < reqlen) {
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pr_warning("B%d no space for %d (only %d) bytes\n",
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bch->nr, reqlen, len);
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if (test_bit(FLG_TRANSPARENT, &bch->Flags)) {
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/* send what we have now and try a new buffer */
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recv_Bchannel(bch, 0, true);
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} else {
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/* on HDLC we have to drop too big frames */
|
|
return -EMSGSIZE;
|
|
}
|
|
} else {
|
|
return len;
|
|
}
|
|
}
|
|
/* update current min/max length first */
|
|
if (unlikely(bch->maxlen != bch->next_maxlen))
|
|
bch->maxlen = bch->next_maxlen;
|
|
if (unlikely(bch->minlen != bch->next_minlen))
|
|
bch->minlen = bch->next_minlen;
|
|
if (unlikely(reqlen > bch->maxlen))
|
|
return -EMSGSIZE;
|
|
if (test_bit(FLG_TRANSPARENT, &bch->Flags)) {
|
|
if (reqlen >= bch->minlen) {
|
|
len = reqlen;
|
|
} else {
|
|
len = 2 * bch->minlen;
|
|
if (len > bch->maxlen)
|
|
len = bch->maxlen;
|
|
}
|
|
} else {
|
|
/* with HDLC we do not know the length yet */
|
|
len = bch->maxlen;
|
|
}
|
|
bch->rx_skb = mI_alloc_skb(len, GFP_ATOMIC);
|
|
if (!bch->rx_skb) {
|
|
pr_warning("B%d receive no memory for %d bytes\n",
|
|
bch->nr, len);
|
|
len = -ENOMEM;
|
|
}
|
|
return len;
|
|
}
|
|
EXPORT_SYMBOL(bchannel_get_rxbuf);
|