Commit a03bb56e authored by Govindarajulu Varadarajan's avatar Govindarajulu Varadarajan Committed by David S. Miller

enic: implement rx_copybreak

Calling dma_map_single()/dma_unmap_single() is quite expensive compared
to copying a small packet. So let's copy short frames and keep the buffers
mapped.
Signed-off-by: default avatarGovindarajulu Varadarajan <_govind@gmx.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e020836d
...@@ -186,6 +186,7 @@ struct enic { ...@@ -186,6 +186,7 @@ struct enic {
____cacheline_aligned struct vnic_cq cq[ENIC_CQ_MAX]; ____cacheline_aligned struct vnic_cq cq[ENIC_CQ_MAX];
unsigned int cq_count; unsigned int cq_count;
struct enic_rfs_flw_tbl rfs_h; struct enic_rfs_flw_tbl rfs_h;
u32 rx_copybreak;
}; };
static inline struct device *enic_get_dev(struct enic *enic) static inline struct device *enic_get_dev(struct enic *enic)
......
...@@ -66,6 +66,8 @@ ...@@ -66,6 +66,8 @@
#define PCI_DEVICE_ID_CISCO_VIC_ENET_DYN 0x0044 /* enet dynamic vnic */ #define PCI_DEVICE_ID_CISCO_VIC_ENET_DYN 0x0044 /* enet dynamic vnic */
#define PCI_DEVICE_ID_CISCO_VIC_ENET_VF 0x0071 /* enet SRIOV VF */ #define PCI_DEVICE_ID_CISCO_VIC_ENET_VF 0x0071 /* enet SRIOV VF */
#define RX_COPYBREAK_DEFAULT 256
/* Supported devices */ /* Supported devices */
static const struct pci_device_id enic_id_table[] = { static const struct pci_device_id enic_id_table[] = {
{ PCI_VDEVICE(CISCO, PCI_DEVICE_ID_CISCO_VIC_ENET) }, { PCI_VDEVICE(CISCO, PCI_DEVICE_ID_CISCO_VIC_ENET) },
...@@ -924,6 +926,7 @@ static void enic_free_rq_buf(struct vnic_rq *rq, struct vnic_rq_buf *buf) ...@@ -924,6 +926,7 @@ static void enic_free_rq_buf(struct vnic_rq *rq, struct vnic_rq_buf *buf)
pci_unmap_single(enic->pdev, buf->dma_addr, pci_unmap_single(enic->pdev, buf->dma_addr,
buf->len, PCI_DMA_FROMDEVICE); buf->len, PCI_DMA_FROMDEVICE);
dev_kfree_skb_any(buf->os_buf); dev_kfree_skb_any(buf->os_buf);
buf->os_buf = NULL;
} }
static int enic_rq_alloc_buf(struct vnic_rq *rq) static int enic_rq_alloc_buf(struct vnic_rq *rq)
...@@ -934,7 +937,24 @@ static int enic_rq_alloc_buf(struct vnic_rq *rq) ...@@ -934,7 +937,24 @@ static int enic_rq_alloc_buf(struct vnic_rq *rq)
unsigned int len = netdev->mtu + VLAN_ETH_HLEN; unsigned int len = netdev->mtu + VLAN_ETH_HLEN;
unsigned int os_buf_index = 0; unsigned int os_buf_index = 0;
dma_addr_t dma_addr; dma_addr_t dma_addr;
struct vnic_rq_buf *buf = rq->to_use;
if (buf->os_buf) {
buf = buf->next;
rq->to_use = buf;
rq->ring.desc_avail--;
if ((buf->index & VNIC_RQ_RETURN_RATE) == 0) {
/* Adding write memory barrier prevents compiler and/or
* CPU reordering, thus avoiding descriptor posting
* before descriptor is initialized. Otherwise, hardware
* can read stale descriptor fields.
*/
wmb();
iowrite32(buf->index, &rq->ctrl->posted_index);
}
return 0;
}
skb = netdev_alloc_skb_ip_align(netdev, len); skb = netdev_alloc_skb_ip_align(netdev, len);
if (!skb) if (!skb)
return -ENOMEM; return -ENOMEM;
...@@ -957,6 +977,25 @@ static void enic_intr_update_pkt_size(struct vnic_rx_bytes_counter *pkt_size, ...@@ -957,6 +977,25 @@ static void enic_intr_update_pkt_size(struct vnic_rx_bytes_counter *pkt_size,
pkt_size->small_pkt_bytes_cnt += pkt_len; pkt_size->small_pkt_bytes_cnt += pkt_len;
} }
static bool enic_rxcopybreak(struct net_device *netdev, struct sk_buff **skb,
struct vnic_rq_buf *buf, u16 len)
{
struct enic *enic = netdev_priv(netdev);
struct sk_buff *new_skb;
if (len > enic->rx_copybreak)
return false;
new_skb = netdev_alloc_skb_ip_align(netdev, len);
if (!new_skb)
return false;
pci_dma_sync_single_for_cpu(enic->pdev, buf->dma_addr, len,
DMA_FROM_DEVICE);
memcpy(new_skb->data, (*skb)->data, len);
*skb = new_skb;
return true;
}
static void enic_rq_indicate_buf(struct vnic_rq *rq, static void enic_rq_indicate_buf(struct vnic_rq *rq,
struct cq_desc *cq_desc, struct vnic_rq_buf *buf, struct cq_desc *cq_desc, struct vnic_rq_buf *buf,
int skipped, void *opaque) int skipped, void *opaque)
...@@ -978,9 +1017,6 @@ static void enic_rq_indicate_buf(struct vnic_rq *rq, ...@@ -978,9 +1017,6 @@ static void enic_rq_indicate_buf(struct vnic_rq *rq,
return; return;
skb = buf->os_buf; skb = buf->os_buf;
prefetch(skb->data - NET_IP_ALIGN);
pci_unmap_single(enic->pdev, buf->dma_addr,
buf->len, PCI_DMA_FROMDEVICE);
cq_enet_rq_desc_dec((struct cq_enet_rq_desc *)cq_desc, cq_enet_rq_desc_dec((struct cq_enet_rq_desc *)cq_desc,
&type, &color, &q_number, &completed_index, &type, &color, &q_number, &completed_index,
...@@ -1011,6 +1047,13 @@ static void enic_rq_indicate_buf(struct vnic_rq *rq, ...@@ -1011,6 +1047,13 @@ static void enic_rq_indicate_buf(struct vnic_rq *rq,
/* Good receive /* Good receive
*/ */
if (!enic_rxcopybreak(netdev, &skb, buf, bytes_written)) {
buf->os_buf = NULL;
pci_unmap_single(enic->pdev, buf->dma_addr, buf->len,
PCI_DMA_FROMDEVICE);
}
prefetch(skb->data - NET_IP_ALIGN);
skb_put(skb, bytes_written); skb_put(skb, bytes_written);
skb->protocol = eth_type_trans(skb, netdev); skb->protocol = eth_type_trans(skb, netdev);
skb_record_rx_queue(skb, q_number); skb_record_rx_queue(skb, q_number);
...@@ -2531,6 +2574,7 @@ static int enic_probe(struct pci_dev *pdev, const struct pci_device_id *ent) ...@@ -2531,6 +2574,7 @@ static int enic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
dev_err(dev, "Cannot register net device, aborting\n"); dev_err(dev, "Cannot register net device, aborting\n");
goto err_out_dev_deinit; goto err_out_dev_deinit;
} }
enic->rx_copybreak = RX_COPYBREAK_DEFAULT;
return 0; return 0;
......
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