[PATCH net 2/3] net: ethernet: ave: Replace NET_IP_ALIGN with AVE_FRAME_HEADROOM

From: Kunihiko Hayashi
Date: Thu Nov 29 2018 - 03:08:49 EST


In commit 26a4676faa1a ("arm64: mm: define NET_IP_ALIGN to 0"),
AVE controller affects this modification because the controller forces
to ignore lower 2bits of buffer start address, and make 2-byte headroom,
that is, data reception starts from (buffer + 2).

This patch defines AVE_FRAME_HEADROOM macro as hardware-specific value,
and replaces NET_IP_ALIGN with it.

Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx>
---
drivers/net/ethernet/socionext/sni_ave.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/socionext/sni_ave.c b/drivers/net/ethernet/socionext/sni_ave.c
index 598b963..6710151 100644
--- a/drivers/net/ethernet/socionext/sni_ave.c
+++ b/drivers/net/ethernet/socionext/sni_ave.c
@@ -194,6 +194,7 @@

/* Parameter for ethernet frame */
#define AVE_MAX_ETHFRAME 1518
+#define AVE_FRAME_HEADROOM 2

/* Parameter for interrupt */
#define AVE_INTM_COUNT 20
@@ -577,12 +578,13 @@ static int ave_rxdesc_prepare(struct net_device *ndev, int entry)

skb = priv->rx.desc[entry].skbs;
if (!skb) {
- skb = netdev_alloc_skb_ip_align(ndev,
- AVE_MAX_ETHFRAME);
+ skb = netdev_alloc_skb(ndev, AVE_MAX_ETHFRAME);
if (!skb) {
netdev_err(ndev, "can't allocate skb for Rx\n");
return -ENOMEM;
}
+ skb->data += AVE_FRAME_HEADROOM;
+ skb->tail += AVE_FRAME_HEADROOM;
}

/* set disable to cmdsts */
@@ -595,12 +597,12 @@ static int ave_rxdesc_prepare(struct net_device *ndev, int entry)
* - Rx buffer begins with 2 byte headroom, and data will be put from
* (buffer + 2).
* To satisfy this, specify the address to put back the buffer
- * pointer advanced by NET_IP_ALIGN by netdev_alloc_skb_ip_align(),
- * and expand the map size by NET_IP_ALIGN.
+ * pointer advanced by AVE_FRAME_HEADROOM, and expand the map size
+ * by AVE_FRAME_HEADROOM.
*/
ret = ave_dma_map(ndev, &priv->rx.desc[entry],
- skb->data - NET_IP_ALIGN,
- AVE_MAX_ETHFRAME + NET_IP_ALIGN,
+ skb->data - AVE_FRAME_HEADROOM,
+ AVE_MAX_ETHFRAME + AVE_FRAME_HEADROOM,
DMA_FROM_DEVICE, &paddr);
if (ret) {
netdev_err(ndev, "can't map skb for Rx\n");
--
2.7.4