netdev: bfin_mac: fix performance issue found by netperf

- Remove dead long delay
- Use proper defines
- Remove broken implementation of the TX DMA Data Alignment TXDWA feature

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/bfin_mac.c

@@ -194,13 +194,13 @@ static int desc_list_init(void)
 		struct dma_descriptor *b = &(r->desc_b);
 
 		/* allocate a new skb for next time receive */
-		new_skb = dev_alloc_skb(PKT_BUF_SZ + 2);
+		new_skb = dev_alloc_skb(PKT_BUF_SZ + NET_IP_ALIGN);
 		if (!new_skb) {
 			printk(KERN_NOTICE DRV_NAME
 			       ": init: low on mem - packet dropped\n");
 			goto init_error;
 		}
-		skb_reserve(new_skb, 2);
+		skb_reserve(new_skb, NET_IP_ALIGN);
 		r->skb = new_skb;
 
 		/*
@@ -566,9 +566,9 @@ static void adjust_tx_list(void)
 	 */
 	if (current_tx_ptr->next->next == tx_list_head) {
 		while (tx_list_head->status.status_word == 0) {
-			mdelay(1);
+			udelay(10);
 			if (tx_list_head->status.status_word != 0
-			    || !(bfin_read_DMA2_IRQ_STATUS() & 0x08)) {
+			    || !(bfin_read_DMA2_IRQ_STATUS() & DMA_RUN)) {
 				goto adjust_head;
 			}
 			if (timeout_cnt-- < 0) {
@@ -606,18 +606,9 @@ static int bfin_mac_hard_start_xmit(struct sk_buff *skb,
 				struct net_device *dev)
 {
 	u16 *data;
-
+	u32 data_align = (unsigned long)(skb->data) & 0x3;
 	current_tx_ptr->skb = skb;
 
-	if (ANOMALY_05000285) {
-		/*
-		 * TXDWA feature is not avaible to older revision < 0.3 silicon
-		 * of BF537
-		 *
-		 * Only if data buffer is ODD WORD alignment, we do not
-		 * need to memcpy
-		 */
-		u32 data_align = (u32)(skb->data) & 0x3;
 	if (data_align == 0x2) {
 		/* move skb->data to current_tx_ptr payload */
 		data = (u16 *)(skb->data) - 1;
@@ -638,55 +629,6 @@ static int bfin_mac_hard_start_xmit(struct sk_buff *skb,
 			(u32)current_tx_ptr->packet,
 			(u32)(current_tx_ptr->packet + skb->len + 2));
 	}
-	} else {
-		/*
-		 * TXDWA feature is avaible to revision < 0.3 silicon of
-		 * BF537 and always avaible to BF52x
-		 */
-		u32 data_align = (u32)(skb->data) & 0x3;
-		if (data_align == 0x0) {
-			u16 sysctl = bfin_read_EMAC_SYSCTL();
-			sysctl |= TXDWA;
-			bfin_write_EMAC_SYSCTL(sysctl);
-
-			/* move skb->data to current_tx_ptr payload */
-			data = (u16 *)(skb->data) - 2;
-			*data = (u16)(skb->len);
-			current_tx_ptr->desc_a.start_addr = (u32)data;
-			/* this is important! */
-			blackfin_dcache_flush_range(
-					(u32)data,
-					(u32)((u8 *)data + skb->len + 4));
-		} else if (data_align == 0x2) {
-			u16 sysctl = bfin_read_EMAC_SYSCTL();
-			sysctl &= ~TXDWA;
-			bfin_write_EMAC_SYSCTL(sysctl);
-
-			/* move skb->data to current_tx_ptr payload */
-			data = (u16 *)(skb->data) - 1;
-			*data = (u16)(skb->len);
-			current_tx_ptr->desc_a.start_addr = (u32)data;
-			/* this is important! */
-			blackfin_dcache_flush_range(
-					(u32)data,
-					(u32)((u8 *)data + skb->len + 4));
-		} else {
-			u16 sysctl = bfin_read_EMAC_SYSCTL();
-			sysctl &= ~TXDWA;
-			bfin_write_EMAC_SYSCTL(sysctl);
-
-			*((u16 *)(current_tx_ptr->packet)) = (u16)(skb->len);
-			memcpy((u8 *)(current_tx_ptr->packet + 2), skb->data,
-				skb->len);
-			current_tx_ptr->desc_a.start_addr =
-				(u32)current_tx_ptr->packet;
-			if (current_tx_ptr->status.status_word != 0)
-				current_tx_ptr->status.status_word = 0;
-			blackfin_dcache_flush_range(
-				(u32)current_tx_ptr->packet,
-				(u32)(current_tx_ptr->packet + skb->len + 2));
-		}
-	}
 
 	/* make sure the internal data buffers in the core are drained
 	 * so that the DMA descriptors are completely written when the
@@ -698,7 +640,7 @@ static int bfin_mac_hard_start_xmit(struct sk_buff *skb,
 	current_tx_ptr->desc_a.config |= DMAEN;
 
 	/* tx dma is running, just return */
-	if (bfin_read_DMA2_IRQ_STATUS() & 0x08)
+	if (bfin_read_DMA2_IRQ_STATUS() & DMA_RUN)
 		goto out;
 
 	/* tx dma is not running */
@@ -724,7 +666,7 @@ static void bfin_mac_rx(struct net_device *dev)
 
 	/* allocate a new skb for next time receive */
 	skb = current_rx_ptr->skb;
-	new_skb = dev_alloc_skb(PKT_BUF_SZ + 2);
+	new_skb = dev_alloc_skb(PKT_BUF_SZ + NET_IP_ALIGN);
 	if (!new_skb) {
 		printk(KERN_NOTICE DRV_NAME
 		       ": rx: low on mem - packet dropped\n");
@@ -732,7 +674,7 @@ static void bfin_mac_rx(struct net_device *dev)
 		goto out;
 	}
 	/* reserve 2 bytes for RXDWA padding */
-	skb_reserve(new_skb, 2);
+	skb_reserve(new_skb, NET_IP_ALIGN);
 	current_rx_ptr->skb = new_skb;
 	current_rx_ptr->desc_a.start_addr = (unsigned long)new_skb->data - 2;