mv643xx_eth: replace array of skbs awaiting transmit completion with a queue
Get rid of the skb pointer array that we currently use for transmit
reclaim, and replace it with an skb queue, to which skbuffs are appended
when they are passed to the xmit function, and removed from the front
and freed when we do transmit queue reclaim and hit a descriptor with
the 'owned by device' bit clear and 'last descriptor' bit set.
Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
diff --git a/drivers/net/mv643xx_eth.c b/drivers/net/mv643xx_eth.c
index 7410eca..099e0be 100644
--- a/drivers/net/mv643xx_eth.c
+++ b/drivers/net/mv643xx_eth.c
@@ -336,7 +336,8 @@
struct tx_desc *tx_desc_area;
dma_addr_t tx_desc_dma;
int tx_desc_area_size;
- struct sk_buff **tx_skb;
+
+ struct sk_buff_head tx_skb;
unsigned long tx_packets;
unsigned long tx_bytes;
@@ -676,10 +677,8 @@
desc->cmd_sts = BUFFER_OWNED_BY_DMA |
ZERO_PADDING | TX_LAST_DESC |
TX_ENABLE_INTERRUPT;
- txq->tx_skb[tx_index] = skb;
} else {
desc->cmd_sts = BUFFER_OWNED_BY_DMA;
- txq->tx_skb[tx_index] = NULL;
}
desc->l4i_chk = 0;
@@ -712,13 +711,10 @@
if (nr_frags) {
txq_submit_frag_skb(txq, skb);
-
length = skb_headlen(skb);
- txq->tx_skb[tx_index] = NULL;
} else {
cmd_sts |= ZERO_PADDING | TX_LAST_DESC | TX_ENABLE_INTERRUPT;
length = skb->len;
- txq->tx_skb[tx_index] = skb;
}
desc->byte_cnt = length;
@@ -772,6 +768,8 @@
desc->l4i_chk = 0;
}
+ __skb_queue_tail(&txq->tx_skb, skb);
+
/* ensure all other descriptors are written before first cmd_sts */
wmb();
desc->cmd_sts = cmd_sts;
@@ -884,8 +882,9 @@
reclaimed++;
txq->tx_desc_count--;
- skb = txq->tx_skb[tx_index];
- txq->tx_skb[tx_index] = NULL;
+ skb = NULL;
+ if (cmd_sts & TX_LAST_DESC)
+ skb = __skb_dequeue(&txq->tx_skb);
if (cmd_sts & ERROR_SUMMARY) {
dev_printk(KERN_INFO, &mp->dev->dev, "tx error\n");
@@ -1692,18 +1691,11 @@
if (txq->tx_desc_area == NULL) {
dev_printk(KERN_ERR, &mp->dev->dev,
"can't allocate tx ring (%d bytes)\n", size);
- goto out;
+ return -ENOMEM;
}
memset(txq->tx_desc_area, 0, size);
txq->tx_desc_area_size = size;
- txq->tx_skb = kmalloc(txq->tx_ring_size * sizeof(*txq->tx_skb),
- GFP_KERNEL);
- if (txq->tx_skb == NULL) {
- dev_printk(KERN_ERR, &mp->dev->dev,
- "can't allocate tx skb ring\n");
- goto out_free;
- }
tx_desc = (struct tx_desc *)txq->tx_desc_area;
for (i = 0; i < txq->tx_ring_size; i++) {
@@ -1719,18 +1711,9 @@
nexti * sizeof(struct tx_desc);
}
+ skb_queue_head_init(&txq->tx_skb);
+
return 0;
-
-out_free:
- if (index == 0 && size <= mp->tx_desc_sram_size)
- iounmap(txq->tx_desc_area);
- else
- dma_free_coherent(NULL, size,
- txq->tx_desc_area,
- txq->tx_desc_dma);
-
-out:
- return -ENOMEM;
}
static void txq_deinit(struct tx_queue *txq)
@@ -1748,8 +1731,6 @@
else
dma_free_coherent(NULL, txq->tx_desc_area_size,
txq->tx_desc_area, txq->tx_desc_dma);
-
- kfree(txq->tx_skb);
}