pasemi_mac: Fix TX ring wrap checking
The old logic didn't detect full (tx) ring cases properly, causing overruns and general badness. Clean it up a bit and abstract out the ring size checks, always making sure to leave 1 slot open. Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Jeff Garzik <jeff@garzik.org>
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02df6cfa09
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021fa22e01
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@ -69,6 +69,10 @@
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#define RX_DESC_INFO(mac, num) ((mac)->rx->desc_info[(num) & (RX_RING_SIZE-1)])
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#define RX_BUFF(mac, num) ((mac)->rx->buffers[(num) & (RX_RING_SIZE-1)])
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#define RING_USED(ring) (((ring)->next_to_fill - (ring)->next_to_clean) \
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& ((ring)->size - 1))
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#define RING_AVAIL(ring) ((ring->size) - RING_USED(ring))
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#define BUF_SIZE 1646 /* 1500 MTU + ETH_HLEN + VLAN_HLEN + 2 64B cachelines */
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MODULE_LICENSE("GPL");
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@ -174,6 +178,7 @@ static int pasemi_mac_setup_rx_resources(struct net_device *dev)
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spin_lock_init(&ring->lock);
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ring->size = RX_RING_SIZE;
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ring->desc_info = kzalloc(sizeof(struct pasemi_mac_buffer) *
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RX_RING_SIZE, GFP_KERNEL);
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@ -253,6 +258,7 @@ static int pasemi_mac_setup_tx_resources(struct net_device *dev)
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spin_lock_init(&ring->lock);
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ring->size = TX_RING_SIZE;
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ring->desc_info = kzalloc(sizeof(struct pasemi_mac_buffer) *
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TX_RING_SIZE, GFP_KERNEL);
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if (!ring->desc_info)
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@ -281,7 +287,7 @@ static int pasemi_mac_setup_tx_resources(struct net_device *dev)
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PAS_DMA_TXCHAN_CFG_UP |
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PAS_DMA_TXCHAN_CFG_WT(2));
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ring->next_to_use = 0;
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ring->next_to_fill = 0;
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ring->next_to_clean = 0;
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snprintf(ring->irq_name, sizeof(ring->irq_name),
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@ -376,9 +382,7 @@ static void pasemi_mac_replenish_rx_ring(struct net_device *dev)
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int start = mac->rx->next_to_fill;
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unsigned int limit, count;
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limit = (mac->rx->next_to_clean + RX_RING_SIZE -
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mac->rx->next_to_fill) & (RX_RING_SIZE - 1);
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limit = RING_AVAIL(mac->rx);
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/* Check to see if we're doing first-time setup */
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if (unlikely(mac->rx->next_to_clean == 0 && mac->rx->next_to_fill == 0))
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limit = RX_RING_SIZE;
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@ -562,7 +566,7 @@ restart:
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spin_lock_irqsave(&mac->tx->lock, flags);
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start = mac->tx->next_to_clean;
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limit = min(mac->tx->next_to_use, start+32);
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limit = min(mac->tx->next_to_fill, start+32);
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count = 0;
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@ -1004,14 +1008,13 @@ static int pasemi_mac_start_tx(struct sk_buff *skb, struct net_device *dev)
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spin_lock_irqsave(&txring->lock, flags);
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if (txring->next_to_clean - txring->next_to_use == TX_RING_SIZE) {
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if (RING_AVAIL(txring) <= 1) {
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spin_unlock_irqrestore(&txring->lock, flags);
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pasemi_mac_clean_tx(mac);
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pasemi_mac_restart_tx_intr(mac);
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spin_lock_irqsave(&txring->lock, flags);
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if (txring->next_to_clean - txring->next_to_use ==
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TX_RING_SIZE) {
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if (RING_AVAIL(txring) <= 1) {
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/* Still no room -- stop the queue and wait for tx
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* intr when there's room.
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*/
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@ -1020,15 +1023,15 @@ static int pasemi_mac_start_tx(struct sk_buff *skb, struct net_device *dev)
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}
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}
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dp = &TX_DESC(mac, txring->next_to_use);
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info = &TX_DESC_INFO(mac, txring->next_to_use);
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dp = &TX_DESC(mac, txring->next_to_fill);
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info = &TX_DESC_INFO(mac, txring->next_to_fill);
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dp->mactx = mactx;
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dp->ptr = ptr;
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info->dma = map;
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info->skb = skb;
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txring->next_to_use++;
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txring->next_to_fill++;
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mac->stats.tx_packets++;
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mac->stats.tx_bytes += skb->len;
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@ -31,7 +31,7 @@ struct pasemi_mac_txring {
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struct pas_dma_xct_descr *desc;
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dma_addr_t dma;
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unsigned int size;
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unsigned int next_to_use;
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unsigned int next_to_fill;
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unsigned int next_to_clean;
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struct pasemi_mac_buffer *desc_info;
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char irq_name[10]; /* "eth%d tx" */
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