int _atomic_dec_and_spin_lock(atomic_t *atomic, spinlock_t *lock)
{
rt_spin_lock(lock);
if (atomic_dec_and_test(atomic))
return 1;
rt_spin_unlock(lock);
return 0;
}
int atomic_dec_and_spin_lock(atomic_t *atomic, spinlock_t *lock)
{
/* Subtract 1 from counter unless that drops it to 0 (ie. it was 1) */
if (atomic_add_unless(atomic, -1, 1))
return 0;
rt_spin_lock(lock);
if (atomic_dec_and_test(atomic))
return 1;
rt_spin_unlock(lock);
return 0;
}
static void usi_spin_lock(spinlock_t *lock)
{
rt_spin_lock(lock);
}
/* The interrupt handler.
* This is called from the CPM handler, not the MPC core interrupt.
*/
static void
scc_enet_interrupt(int irq, unsigned long rtdev_id)
{
struct rtnet_device *rtdev = (struct rtnet_device *)rtdev_id;
int packets = 0;
volatile struct scc_enet_private *cep;
volatile cbd_t *bdp;
ushort int_events;
int must_restart;
cep = (struct scc_enet_private *)rtdev->priv;
/* Get the interrupt events that caused us to be here.
*/
int_events = cep->sccp->scc_scce;
cep->sccp->scc_scce = int_events;
must_restart = 0;
/* Handle receive event in its own function.
*/
if (int_events & SCCE_ENET_RXF) {
scc_enet_rx(rtdev, &packets);
}
/* Check for a transmit error. The manual is a little unclear
* about this, so the debug code until I get it figured out. It
* appears that if TXE is set, then TXB is not set. However,
* if carrier sense is lost during frame transmission, the TXE
* bit is set, "and continues the buffer transmission normally."
* I don't know if "normally" implies TXB is set when the buffer
* descriptor is closed.....trial and error :-).
*/
/* Transmit OK, or non-fatal error. Update the buffer descriptors.
*/
if (int_events & (SCCE_ENET_TXE | SCCE_ENET_TXB)) {
rt_spin_lock(&cep->lock);
bdp = cep->dirty_tx;
while ((bdp->cbd_sc&BD_ENET_TX_READY)==0) {
RT_DEBUG(__FUNCTION__": Tx ok\n");
if ((bdp==cep->cur_tx) && (cep->tx_full == 0))
break;
if (bdp->cbd_sc & BD_ENET_TX_HB) /* No heartbeat */
cep->stats.tx_heartbeat_errors++;
if (bdp->cbd_sc & BD_ENET_TX_LC) /* Late collision */
cep->stats.tx_window_errors++;
if (bdp->cbd_sc & BD_ENET_TX_RL) /* Retrans limit */
cep->stats.tx_aborted_errors++;
if (bdp->cbd_sc & BD_ENET_TX_UN) /* Underrun */
cep->stats.tx_fifo_errors++;
if (bdp->cbd_sc & BD_ENET_TX_CSL) /* Carrier lost */
cep->stats.tx_carrier_errors++;
/* No heartbeat or Lost carrier are not really bad errors.
* The others require a restart transmit command.
*/
if (bdp->cbd_sc &
(BD_ENET_TX_LC | BD_ENET_TX_RL | BD_ENET_TX_UN)) {
must_restart = 1;
cep->stats.tx_errors++;
}
cep->stats.tx_packets++;
/* Deferred means some collisions occurred during transmit,
* but we eventually sent the packet OK.
*/
if (bdp->cbd_sc & BD_ENET_TX_DEF)
cep->stats.collisions++;
/* Free the sk buffer associated with this last transmit.
*/
dev_kfree_rtskb(cep->tx_skbuff[cep->skb_dirty]);
cep->skb_dirty = (cep->skb_dirty + 1) & TX_RING_MOD_MASK;
/* Update pointer to next buffer descriptor to be transmitted.
*/
if (bdp->cbd_sc & BD_ENET_TX_WRAP)
bdp = cep->tx_bd_base;
else
bdp++;
/* I don't know if we can be held off from processing these
* interrupts for more than one frame time. I really hope
* not. In such a case, we would now want to check the
* currently available BD (cur_tx) and determine if any
* buffers between the dirty_tx and cur_tx have also been
* sent. We would want to process anything in between that
* does not have BD_ENET_TX_READY set.
*/
/* Since we have freed up a buffer, the ring is no longer
* full.
*/
if (cep->tx_full) {
cep->tx_full = 0;
if (rtnetif_queue_stopped(rtdev))
rtnetif_wake_queue(rtdev);
}
cep->dirty_tx = (cbd_t *)bdp;
}
if (must_restart) {
volatile cpm8xx_t *cp;
/* Some transmit errors cause the transmitter to shut
* down. We now issue a restart transmit. Since the
* errors close the BD and update the pointers, the restart
* _should_ pick up without having to reset any of our
* pointers either.
*/
cp = cpmp;
cp->cp_cpcr =
mk_cr_cmd(CPM_CR_ENET, CPM_CR_RESTART_TX) | CPM_CR_FLG;
while (cp->cp_cpcr & CPM_CR_FLG);
}
rt_spin_unlock(&cep->lock);
}
/* Check for receive busy, i.e. packets coming but no place to
* put them. This "can't happen" because the receive interrupt
* is tossing previous frames.
*/
if (int_events & SCCE_ENET_BSY) {
cep->stats.rx_dropped++;
printk("CPM ENET: BSY can't happen.\n");
}
if (packets > 0)
rt_mark_stack_mgr(rtdev);
rt_enable_irq(irq);
return;
}
static int
scc_enet_start_xmit(struct rtskb *skb, struct rtnet_device *rtdev)
{
struct scc_enet_private *cep = (struct scc_enet_private *)rtdev->priv;
volatile cbd_t *bdp;
RT_DEBUG(__FUNCTION__": ...\n");
/* Fill in a Tx ring entry */
bdp = cep->cur_tx;
#ifndef final_version
if (bdp->cbd_sc & BD_ENET_TX_READY) {
/* Ooops. All transmit buffers are full. Bail out.
* This should not happen, since cep->tx_busy should be set.
*/
printk("%s: tx queue full!.\n", rtdev->name);
return 1;
}
#endif
/* Clear all of the status flags.
*/
bdp->cbd_sc &= ~BD_ENET_TX_STATS;
/* If the frame is short, tell CPM to pad it.
*/
if (skb->len <= ETH_ZLEN)
bdp->cbd_sc |= BD_ENET_TX_PAD;
else
bdp->cbd_sc &= ~BD_ENET_TX_PAD;
/* Set buffer length and buffer pointer.
*/
bdp->cbd_datlen = skb->len;
bdp->cbd_bufaddr = __pa(skb->data);
/* Save skb pointer.
*/
cep->tx_skbuff[cep->skb_cur] = skb;
cep->stats.tx_bytes += skb->len;
cep->skb_cur = (cep->skb_cur+1) & TX_RING_MOD_MASK;
/* Push the data cache so the CPM does not get stale memory
* data.
*/
flush_dcache_range((unsigned long)(skb->data),
(unsigned long)(skb->data + skb->len));
/* Prevent interrupts from changing the Tx ring from underneath us. */
// *** RTnet ***
rt_sem_wait(&rtdev->xmit_sem);
rt_disable_irq(rtdev->irq);
rt_spin_lock(&cep->lock);
/* Send it on its way. Tell CPM its ready, interrupt when done,
* its the last BD of the frame, and to put the CRC on the end.
*/
bdp->cbd_sc |= (BD_ENET_TX_READY | BD_ENET_TX_INTR | BD_ENET_TX_LAST | BD_ENET_TX_TC);
#if 0
dev->trans_start = jiffies;
#endif
/* If this was the last BD in the ring, start at the beginning again.
*/
if (bdp->cbd_sc & BD_ENET_TX_WRAP)
bdp = cep->tx_bd_base;
else
bdp++;
if (bdp->cbd_sc & BD_ENET_TX_READY) {
rtnetif_stop_queue(rtdev);
cep->tx_full = 1;
}
cep->cur_tx = (cbd_t *)bdp;
rt_spin_unlock(&cep->lock);
rt_enable_irq(rtdev->irq);
rt_sem_signal(&rtdev->xmit_sem);
return 0;
}
