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Message-ID: <1411976824-28824-1-git-send-email-b38611@freescale.com>
Date: Mon, 29 Sep 2014 15:47:04 +0800
From: Fugang Duan <b38611@...escale.com>
To: <b20596@...escale.com>, <davem@...emloft.net>,
<romieu@...zoreil.com>
CC: <netdev@...r.kernel.org>, <shawn.guo@...aro.org>,
<B20596@...escale.com>, <bhutchings@...arflare.com>,
<b38611@...escale.com>
Subject: [PATCH v2 1/1] net: fec: implement rx_copybreak to improve rx performance
- Copy short frames and keep the buffers mapped, re-allocate skb instead of
memory copy for long frames.
- Add support for setting/getting rx_copybreak using generic ethtool tunable
Changes V2:
* Implements rx_copybreak
* Rx_copybreak provides module parameter to change this value
* Add tunable_ops support for rx_copybreak
Signed-off-by: Fugang Duan <B38611@...escale.com>
Signed-off-by: Frank Li <Frank.Li@...escale.com>
---
drivers/net/ethernet/freescale/fec.h | 2 +
drivers/net/ethernet/freescale/fec_main.c | 212 ++++++++++++++++++++---------
2 files changed, 149 insertions(+), 65 deletions(-)
diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h
index 354a309..1d5e182 100644
--- a/drivers/net/ethernet/freescale/fec.h
+++ b/drivers/net/ethernet/freescale/fec.h
@@ -482,6 +482,8 @@ struct fec_enet_private {
unsigned int tx_pkts_itr;
unsigned int tx_time_itr;
unsigned int itr_clk_rate;
+
+ u32 rx_copybreak;
};
void fec_ptp_init(struct platform_device *pdev);
diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 2c73434..276a0aa 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -176,6 +176,12 @@ static unsigned char macaddr[ETH_ALEN];
module_param_array(macaddr, byte, NULL, 0);
MODULE_PARM_DESC(macaddr, "FEC Ethernet MAC address");
+#define COPYBREAK_DEFAULT 256
+static unsigned int copybreak __read_mostly = COPYBREAK_DEFAULT;
+module_param(copybreak, uint, 0644);
+MODULE_PARM_DESC(copybreak,
+ "Maximum packet size that is copied to a new buffer on receive");
+
#if defined(CONFIG_M5272)
/*
* Some hardware gets it MAC address out of local flash memory.
@@ -1322,6 +1328,50 @@ fec_enet_tx(struct net_device *ndev)
return;
}
+static int
+fec_enet_new_rxbdp(struct net_device *ndev, struct bufdesc *bdp, struct sk_buff *skb)
+{
+ struct fec_enet_private *fep = netdev_priv(ndev);
+ int off;
+
+ off = ((unsigned long)skb->data) & fep->rx_align;
+ if (off)
+ skb_reserve(skb, fep->rx_align + 1 - off);
+
+ bdp->cbd_bufaddr = dma_map_single(&fep->pdev->dev, skb->data,
+ FEC_ENET_RX_FRSIZE - fep->rx_align,
+ DMA_FROM_DEVICE);
+ if (dma_mapping_error(&fep->pdev->dev, bdp->cbd_bufaddr)) {
+ if (net_ratelimit())
+ netdev_err(ndev, "Rx DMA memory map failed\n");
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static bool fec_enet_copybreak(struct net_device *ndev, struct sk_buff **skb,
+ struct bufdesc *bdp, u32 length)
+{
+ struct fec_enet_private *fep = netdev_priv(ndev);
+ struct sk_buff *new_skb;
+
+ if (length > fep->rx_copybreak)
+ return false;
+
+ new_skb = netdev_alloc_skb(ndev, length);
+ if (!new_skb)
+ return false;
+
+ dma_sync_single_for_cpu(&fep->pdev->dev, bdp->cbd_bufaddr,
+ FEC_ENET_RX_FRSIZE - fep->rx_align,
+ DMA_FROM_DEVICE);
+ memcpy(new_skb->data, (*skb)->data, length);
+ *skb = new_skb;
+
+ return true;
+}
+
/* During a receive, the cur_rx points to the current incoming buffer.
* When we update through the ring, if the next incoming buffer has
* not been given to the system, we just set the empty indicator,
@@ -1336,7 +1386,8 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)
struct fec_enet_priv_rx_q *rxq;
struct bufdesc *bdp;
unsigned short status;
- struct sk_buff *skb;
+ struct sk_buff *skb_new = NULL;
+ struct sk_buff *skb;
ushort pkt_len;
__u8 *data;
int pkt_received = 0;
@@ -1344,6 +1395,7 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)
bool vlan_packet_rcvd = false;
u16 vlan_tag;
int index = 0;
+ bool is_copybreak;
#ifdef CONFIG_M532x
flush_cache_all();
@@ -1401,11 +1453,27 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)
ndev->stats.rx_bytes += pkt_len;
index = fec_enet_get_bd_index(rxq->rx_bd_base, bdp, fep);
- data = rxq->rx_skbuff[index]->data;
- dma_sync_single_for_cpu(&fep->pdev->dev, bdp->cbd_bufaddr,
- FEC_ENET_RX_FRSIZE - fep->rx_align,
- DMA_FROM_DEVICE);
+ skb = rxq->rx_skbuff[index];
+ /* The packet length includes FCS, but we don't want to
+ * include that when passing upstream as it messes up
+ * bridging applications.
+ */
+ is_copybreak = fec_enet_copybreak(ndev, &skb, bdp, pkt_len - 4);
+ if (!is_copybreak) {
+ skb_new = netdev_alloc_skb(ndev, FEC_ENET_RX_FRSIZE);
+ if (unlikely(!skb_new)) {
+ ndev->stats.rx_dropped++;
+ goto rx_processing_done;
+ }
+ dma_unmap_single(&fep->pdev->dev, bdp->cbd_bufaddr,
+ FEC_ENET_RX_FRSIZE - fep->rx_align,
+ DMA_FROM_DEVICE);
+ }
+
+ prefetch(skb->data - NET_IP_ALIGN);
+ skb_put(skb, pkt_len - 4);
+ data = skb->data;
if (id_entry->driver_data & FEC_QUIRK_SWAP_FRAME)
swap_buffer(data, pkt_len);
@@ -1422,62 +1490,48 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)
struct vlan_hdr *vlan_header =
(struct vlan_hdr *) (data + ETH_HLEN);
vlan_tag = ntohs(vlan_header->h_vlan_TCI);
- pkt_len -= VLAN_HLEN;
vlan_packet_rcvd = true;
+
+ skb_copy_to_linear_data_offset(skb, VLAN_HLEN,
+ data, (2 * ETH_ALEN));
+ skb_pull(skb, VLAN_HLEN);
}
- /* This does 16 byte alignment, exactly what we need.
- * The packet length includes FCS, but we don't want to
- * include that when passing upstream as it messes up
- * bridging applications.
- */
- skb = netdev_alloc_skb(ndev, pkt_len - 4 + NET_IP_ALIGN);
+ skb->protocol = eth_type_trans(skb, ndev);
- if (unlikely(!skb)) {
- ndev->stats.rx_dropped++;
- } else {
- int payload_offset = (2 * ETH_ALEN);
- skb_reserve(skb, NET_IP_ALIGN);
- skb_put(skb, pkt_len - 4); /* Make room */
-
- /* Extract the frame data without the VLAN header. */
- skb_copy_to_linear_data(skb, data, (2 * ETH_ALEN));
- if (vlan_packet_rcvd)
- payload_offset = (2 * ETH_ALEN) + VLAN_HLEN;
- skb_copy_to_linear_data_offset(skb, (2 * ETH_ALEN),
- data + payload_offset,
- pkt_len - 4 - (2 * ETH_ALEN));
-
- skb->protocol = eth_type_trans(skb, ndev);
-
- /* Get receive timestamp from the skb */
- if (fep->hwts_rx_en && fep->bufdesc_ex)
- fec_enet_hwtstamp(fep, ebdp->ts,
- skb_hwtstamps(skb));
-
- if (fep->bufdesc_ex &&
- (fep->csum_flags & FLAG_RX_CSUM_ENABLED)) {
- if (!(ebdp->cbd_esc & FLAG_RX_CSUM_ERROR)) {
- /* don't check it */
- skb->ip_summed = CHECKSUM_UNNECESSARY;
- } else {
- skb_checksum_none_assert(skb);
- }
+ /* Get receive timestamp from the skb */
+ if (fep->hwts_rx_en && fep->bufdesc_ex)
+ fec_enet_hwtstamp(fep, ebdp->ts,
+ skb_hwtstamps(skb));
+
+ if (fep->bufdesc_ex &&
+ (fep->csum_flags & FLAG_RX_CSUM_ENABLED)) {
+ if (!(ebdp->cbd_esc & FLAG_RX_CSUM_ERROR)) {
+ /* don't check it */
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+ } else {
+ skb_checksum_none_assert(skb);
}
+ }
- /* Handle received VLAN packets */
- if (vlan_packet_rcvd)
- __vlan_hwaccel_put_tag(skb,
- htons(ETH_P_8021Q),
- vlan_tag);
+ /* Handle received VLAN packets */
+ if (vlan_packet_rcvd)
+ __vlan_hwaccel_put_tag(skb,
+ htons(ETH_P_8021Q),
+ vlan_tag);
- napi_gro_receive(&fep->napi, skb);
+ napi_gro_receive(&fep->napi, skb);
+
+ if (is_copybreak) {
+ dma_sync_single_for_device(&fep->pdev->dev, bdp->cbd_bufaddr,
+ FEC_ENET_RX_FRSIZE - fep->rx_align,
+ DMA_FROM_DEVICE);
+ } else {
+ rxq->rx_skbuff[index] = skb_new;
+ fec_enet_new_rxbdp(ndev, bdp, skb_new);
}
- dma_sync_single_for_device(&fep->pdev->dev, bdp->cbd_bufaddr,
- FEC_ENET_RX_FRSIZE - fep->rx_align,
- DMA_FROM_DEVICE);
rx_processing_done:
/* Clear the status flags for this buffer */
status &= ~BD_ENET_RX_STATS;
@@ -2392,6 +2446,44 @@ static void fec_enet_itr_coal_init(struct net_device *ndev)
fec_enet_set_coalesce(ndev, &ec);
}
+static int fec_enet_get_tunable(struct net_device *netdev,
+ const struct ethtool_tunable *tuna,
+ void *data)
+{
+ struct fec_enet_private *fep = netdev_priv(netdev);
+ int ret = 0;
+
+ switch (tuna->id) {
+ case ETHTOOL_RX_COPYBREAK:
+ *(u32 *)data = fep->rx_copybreak;
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ return ret;
+}
+
+static int fec_enet_set_tunable(struct net_device *netdev,
+ const struct ethtool_tunable *tuna,
+ const void *data)
+{
+ struct fec_enet_private *fep = netdev_priv(netdev);
+ int ret = 0;
+
+ switch (tuna->id) {
+ case ETHTOOL_RX_COPYBREAK:
+ fep->rx_copybreak = *(u32 *)data;
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ return ret;
+}
+
static const struct ethtool_ops fec_enet_ethtool_ops = {
.get_settings = fec_enet_get_settings,
.set_settings = fec_enet_set_settings,
@@ -2408,6 +2500,8 @@ static const struct ethtool_ops fec_enet_ethtool_ops = {
.get_sset_count = fec_enet_get_sset_count,
#endif
.get_ts_info = fec_enet_get_ts_info,
+ .get_tunable = fec_enet_get_tunable,
+ .set_tunable = fec_enet_set_tunable,
};
static int fec_enet_ioctl(struct net_device *ndev, struct ifreq *rq, int cmd)
@@ -2553,33 +2647,20 @@ fec_enet_alloc_rxq_buffers(struct net_device *ndev, unsigned int queue)
struct sk_buff *skb;
struct bufdesc *bdp;
struct fec_enet_priv_rx_q *rxq;
- unsigned int off;
rxq = fep->rx_queue[queue];
bdp = rxq->rx_bd_base;
for (i = 0; i < rxq->rx_ring_size; i++) {
- dma_addr_t addr;
-
skb = netdev_alloc_skb(ndev, FEC_ENET_RX_FRSIZE);
if (!skb)
goto err_alloc;
- off = ((unsigned long)skb->data) & fep->rx_align;
- if (off)
- skb_reserve(skb, fep->rx_align + 1 - off);
-
- addr = dma_map_single(&fep->pdev->dev, skb->data,
- FEC_ENET_RX_FRSIZE - fep->rx_align, DMA_FROM_DEVICE);
-
- if (dma_mapping_error(&fep->pdev->dev, addr)) {
+ if (fec_enet_new_rxbdp(ndev, bdp, skb)) {
dev_kfree_skb(skb);
- if (net_ratelimit())
- netdev_err(ndev, "Rx DMA memory map failed\n");
goto err_alloc;
}
rxq->rx_skbuff[i] = skb;
- bdp->cbd_bufaddr = addr;
bdp->cbd_sc = BD_ENET_RX_EMPTY;
if (fep->bufdesc_ex) {
@@ -3240,6 +3321,7 @@ fec_probe(struct platform_device *pdev)
if (fep->bufdesc_ex && fep->ptp_clock)
netdev_info(ndev, "registered PHC device %d\n", fep->dev_id);
+ fep->rx_copybreak = copybreak;
INIT_WORK(&fep->tx_timeout_work, fec_enet_timeout_work);
return 0;
--
1.7.8
--
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