int ctcm_ch_alloc_buffer(struct channel *ch)
{
clear_normalized_cda(&ch->ccw[1]);
ch->trans_skb = __dev_alloc_skb(ch->max_bufsize, GFP_ATOMIC | GFP_DMA);
if (ch->trans_skb == NULL) {
CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
"%s(%s): %s trans_skb allocation error",
CTCM_FUNTAIL, ch->id,
(CHANNEL_DIRECTION(ch->flags) == READ) ? "RX" : "TX");
return -ENOMEM;
}
ch->ccw[1].count = ch->max_bufsize;
if (set_normalized_cda(&ch->ccw[1], ch->trans_skb->data)) {
dev_kfree_skb(ch->trans_skb);
ch->trans_skb = NULL;
CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
"%s(%s): %s set norm_cda failed",
CTCM_FUNTAIL, ch->id,
(CHANNEL_DIRECTION(ch->flags) == READ) ? "RX" : "TX");
return -ENOMEM;
}
ch->ccw[1].count = 0;
ch->trans_skb_data = ch->trans_skb->data;
ch->flags &= ~CHANNEL_FLAGS_BUFSIZE_CHANGED;
return 0;
}
/**
* Transmit a packet.
* This is a helper function for ctcm_tx().
*
* ch Channel to be used for sending.
* skb Pointer to struct sk_buff of packet to send.
* The linklevel header has already been set up
* by ctcm_tx().
*
* returns 0 on success, -ERRNO on failure. (Never fails.)
*/
static int ctcm_transmit_skb(struct channel *ch, struct sk_buff *skb)
{
unsigned long saveflags;
struct ll_header header;
int rc = 0;
__u16 block_len;
int ccw_idx;
struct sk_buff *nskb;
unsigned long hi;
/* we need to acquire the lock for testing the state
* otherwise we can have an IRQ changing the state to
* TXIDLE after the test but before acquiring the lock.
*/
spin_lock_irqsave(&ch->collect_lock, saveflags);
if (fsm_getstate(ch->fsm) != CTC_STATE_TXIDLE) {
int l = skb->len + LL_HEADER_LENGTH;
if (ch->collect_len + l > ch->max_bufsize - 2) {
spin_unlock_irqrestore(&ch->collect_lock, saveflags);
return -EBUSY;
} else {
atomic_inc(&skb->users);
header.length = l;
header.type = skb->protocol;
header.unused = 0;
memcpy(skb_push(skb, LL_HEADER_LENGTH), &header,
LL_HEADER_LENGTH);
skb_queue_tail(&ch->collect_queue, skb);
ch->collect_len += l;
}
spin_unlock_irqrestore(&ch->collect_lock, saveflags);
goto done;
}
spin_unlock_irqrestore(&ch->collect_lock, saveflags);
/*
* Protect skb against beeing free'd by upper
* layers.
*/
atomic_inc(&skb->users);
ch->prof.txlen += skb->len;
header.length = skb->len + LL_HEADER_LENGTH;
header.type = skb->protocol;
header.unused = 0;
memcpy(skb_push(skb, LL_HEADER_LENGTH), &header, LL_HEADER_LENGTH);
block_len = skb->len + 2;
*((__u16 *)skb_push(skb, 2)) = block_len;
/*
* IDAL support in CTCM is broken, so we have to
* care about skb's above 2G ourselves.
*/
hi = ((unsigned long)skb_tail_pointer(skb) + LL_HEADER_LENGTH) >> 31;
if (hi) {
nskb = alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
if (!nskb) {
atomic_dec(&skb->users);
skb_pull(skb, LL_HEADER_LENGTH + 2);
ctcm_clear_busy(ch->netdev);
return -ENOMEM;
} else {
memcpy(skb_put(nskb, skb->len), skb->data, skb->len);
atomic_inc(&nskb->users);
atomic_dec(&skb->users);
dev_kfree_skb_irq(skb);
skb = nskb;
}
}
ch->ccw[4].count = block_len;
if (set_normalized_cda(&ch->ccw[4], skb->data)) {
/*
* idal allocation failed, try via copying to
* trans_skb. trans_skb usually has a pre-allocated
* idal.
*/
if (ctcm_checkalloc_buffer(ch)) {
/*
* Remove our header. It gets added
* again on retransmit.
*/
atomic_dec(&skb->users);
skb_pull(skb, LL_HEADER_LENGTH + 2);
ctcm_clear_busy(ch->netdev);
return -ENOMEM;
}
skb_reset_tail_pointer(ch->trans_skb);
ch->trans_skb->len = 0;
ch->ccw[1].count = skb->len;
skb_copy_from_linear_data(skb,
skb_put(ch->trans_skb, skb->len), skb->len);
atomic_dec(&skb->users);
dev_kfree_skb_irq(skb);
ccw_idx = 0;
} else {
skb_queue_tail(&ch->io_queue, skb);
ccw_idx = 3;
}
ch->retry = 0;
fsm_newstate(ch->fsm, CTC_STATE_TX);
fsm_addtimer(&ch->timer, CTCM_TIME_5_SEC, CTC_EVENT_TIMER, ch);
spin_lock_irqsave(get_ccwdev_lock(ch->cdev), saveflags);
ch->prof.send_stamp = current_kernel_time(); /* xtime */
rc = ccw_device_start(ch->cdev, &ch->ccw[ccw_idx],
(unsigned long)ch, 0xff, 0);
spin_unlock_irqrestore(get_ccwdev_lock(ch->cdev), saveflags);
if (ccw_idx == 3)
ch->prof.doios_single++;
if (rc != 0) {
fsm_deltimer(&ch->timer);
ctcm_ccw_check_rc(ch, rc, "single skb TX");
if (ccw_idx == 3)
skb_dequeue_tail(&ch->io_queue);
/*
* Remove our header. It gets added
* again on retransmit.
*/
skb_pull(skb, LL_HEADER_LENGTH + 2);
} else if (ccw_idx == 0) {
struct net_device *dev = ch->netdev;
struct ctcm_priv *priv = dev->ml_priv;
priv->stats.tx_packets++;
priv->stats.tx_bytes += skb->len - LL_HEADER_LENGTH;
}
done:
ctcm_clear_busy(ch->netdev);
return rc;
}
static int ctcm_transmit_skb(struct channel *ch, struct sk_buff *skb)
{
unsigned long saveflags;
struct ll_header header;
int rc = 0;
__u16 block_len;
int ccw_idx;
struct sk_buff *nskb;
unsigned long hi;
spin_lock_irqsave(&ch->collect_lock, saveflags);
if (fsm_getstate(ch->fsm) != CTC_STATE_TXIDLE) {
int l = skb->len + LL_HEADER_LENGTH;
if (ch->collect_len + l > ch->max_bufsize - 2) {
spin_unlock_irqrestore(&ch->collect_lock, saveflags);
return -EBUSY;
} else {
atomic_inc(&skb->users);
header.length = l;
header.type = skb->protocol;
header.unused = 0;
memcpy(skb_push(skb, LL_HEADER_LENGTH), &header,
LL_HEADER_LENGTH);
skb_queue_tail(&ch->collect_queue, skb);
ch->collect_len += l;
}
spin_unlock_irqrestore(&ch->collect_lock, saveflags);
goto done;
}
spin_unlock_irqrestore(&ch->collect_lock, saveflags);
atomic_inc(&skb->users);
ch->prof.txlen += skb->len;
header.length = skb->len + LL_HEADER_LENGTH;
header.type = skb->protocol;
header.unused = 0;
memcpy(skb_push(skb, LL_HEADER_LENGTH), &header, LL_HEADER_LENGTH);
block_len = skb->len + 2;
*((__u16 *)skb_push(skb, 2)) = block_len;
hi = ((unsigned long)skb_tail_pointer(skb) + LL_HEADER_LENGTH) >> 31;
if (hi) {
nskb = alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
if (!nskb) {
atomic_dec(&skb->users);
skb_pull(skb, LL_HEADER_LENGTH + 2);
ctcm_clear_busy(ch->netdev);
return -ENOMEM;
} else {
memcpy(skb_put(nskb, skb->len), skb->data, skb->len);
atomic_inc(&nskb->users);
atomic_dec(&skb->users);
dev_kfree_skb_irq(skb);
skb = nskb;
}
}
ch->ccw[4].count = block_len;
if (set_normalized_cda(&ch->ccw[4], skb->data)) {
if (ctcm_checkalloc_buffer(ch)) {
atomic_dec(&skb->users);
skb_pull(skb, LL_HEADER_LENGTH + 2);
ctcm_clear_busy(ch->netdev);
return -ENOMEM;
}
skb_reset_tail_pointer(ch->trans_skb);
ch->trans_skb->len = 0;
ch->ccw[1].count = skb->len;
skb_copy_from_linear_data(skb,
skb_put(ch->trans_skb, skb->len), skb->len);
atomic_dec(&skb->users);
dev_kfree_skb_irq(skb);
ccw_idx = 0;
} else {
skb_queue_tail(&ch->io_queue, skb);
ccw_idx = 3;
}
ch->retry = 0;
fsm_newstate(ch->fsm, CTC_STATE_TX);
fsm_addtimer(&ch->timer, CTCM_TIME_5_SEC, CTC_EVENT_TIMER, ch);
spin_lock_irqsave(get_ccwdev_lock(ch->cdev), saveflags);
ch->prof.send_stamp = current_kernel_time();
rc = ccw_device_start(ch->cdev, &ch->ccw[ccw_idx],
(unsigned long)ch, 0xff, 0);
spin_unlock_irqrestore(get_ccwdev_lock(ch->cdev), saveflags);
if (ccw_idx == 3)
ch->prof.doios_single++;
if (rc != 0) {
fsm_deltimer(&ch->timer);
ctcm_ccw_check_rc(ch, rc, "single skb TX");
if (ccw_idx == 3)
skb_dequeue_tail(&ch->io_queue);
skb_pull(skb, LL_HEADER_LENGTH + 2);
} else if (ccw_idx == 0) {
struct net_device *dev = ch->netdev;
struct ctcm_priv *priv = dev->ml_priv;
priv->stats.tx_packets++;
priv->stats.tx_bytes += skb->len - LL_HEADER_LENGTH;
}
done:
ctcm_clear_busy(ch->netdev);
return rc;
}