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