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authorScott Feldman <scofeldm@cisco.com>2009-09-03 17:02:03 +0000
committerDavid S. Miller <davem@davemloft.net>2009-09-03 20:19:11 -0700
commitea0d7d9181b0831f1b570b02fa02a15f25520c12 (patch)
tree8ec141dc43dd2a8999a3dd69231854e90e11f309
parent4badc385d1a9e140ad0992537237fc22211adad0 (diff)
enic: bug fix: split TSO fragments larger than 16K into multiple descs
enic WQ desc supports a maximum 16K buf size, so split any send fragments larger than 16K into several descs. Signed-off-by: Scott Feldman <scofeldm@cisco.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/enic/enic_main.c87
1 files changed, 69 insertions, 18 deletions
diff --git a/drivers/net/enic/enic_main.c b/drivers/net/enic/enic_main.c
index 58cae6e6a59..bc5cb225dda 100644
--- a/drivers/net/enic/enic_main.c
+++ b/drivers/net/enic/enic_main.c
@@ -44,10 +44,15 @@
#include "enic.h"
#define ENIC_NOTIFY_TIMER_PERIOD (2 * HZ)
+#define WQ_ENET_MAX_DESC_LEN (1 << WQ_ENET_LEN_BITS)
+#define MAX_TSO (1 << 16)
+#define ENIC_DESC_MAX_SPLITS (MAX_TSO / WQ_ENET_MAX_DESC_LEN + 1)
+
+#define PCI_DEVICE_ID_CISCO_VIC_ENET 0x0043 /* ethernet vnic */
/* Supported devices */
static struct pci_device_id enic_id_table[] = {
- { PCI_VDEVICE(CISCO, 0x0043) },
+ { PCI_VDEVICE(CISCO, PCI_DEVICE_ID_CISCO_VIC_ENET) },
{ 0, } /* end of table */
};
@@ -310,7 +315,8 @@ static int enic_wq_service(struct vnic_dev *vdev, struct cq_desc *cq_desc,
opaque);
if (netif_queue_stopped(enic->netdev) &&
- vnic_wq_desc_avail(&enic->wq[q_number]) >= MAX_SKB_FRAGS + 1)
+ vnic_wq_desc_avail(&enic->wq[q_number]) >=
+ (MAX_SKB_FRAGS + ENIC_DESC_MAX_SPLITS))
netif_wake_queue(enic->netdev);
spin_unlock(&enic->wq_lock[q_number]);
@@ -525,7 +531,11 @@ static inline void enic_queue_wq_skb_vlan(struct enic *enic,
unsigned int len_left = skb->len - head_len;
int eop = (len_left == 0);
- /* Queue the main skb fragment */
+ /* Queue the main skb fragment. The fragments are no larger
+ * than max MTU(9000)+ETH_HDR_LEN(14) bytes, which is less
+ * than WQ_ENET_MAX_DESC_LEN length. So only one descriptor
+ * per fragment is queued.
+ */
enic_queue_wq_desc(wq, skb,
pci_map_single(enic->pdev, skb->data,
head_len, PCI_DMA_TODEVICE),
@@ -547,7 +557,11 @@ static inline void enic_queue_wq_skb_csum_l4(struct enic *enic,
unsigned int csum_offset = hdr_len + skb->csum_offset;
int eop = (len_left == 0);
- /* Queue the main skb fragment */
+ /* Queue the main skb fragment. The fragments are no larger
+ * than max MTU(9000)+ETH_HDR_LEN(14) bytes, which is less
+ * than WQ_ENET_MAX_DESC_LEN length. So only one descriptor
+ * per fragment is queued.
+ */
enic_queue_wq_desc_csum_l4(wq, skb,
pci_map_single(enic->pdev, skb->data,
head_len, PCI_DMA_TODEVICE),
@@ -565,10 +579,14 @@ static inline void enic_queue_wq_skb_tso(struct enic *enic,
struct vnic_wq *wq, struct sk_buff *skb, unsigned int mss,
int vlan_tag_insert, unsigned int vlan_tag)
{
- unsigned int head_len = skb_headlen(skb);
- unsigned int len_left = skb->len - head_len;
+ unsigned int frag_len_left = skb_headlen(skb);
+ unsigned int len_left = skb->len - frag_len_left;
unsigned int hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb);
int eop = (len_left == 0);
+ unsigned int len;
+ dma_addr_t dma_addr;
+ unsigned int offset = 0;
+ skb_frag_t *frag;
/* Preload TCP csum field with IP pseudo hdr calculated
* with IP length set to zero. HW will later add in length
@@ -584,17 +602,49 @@ static inline void enic_queue_wq_skb_tso(struct enic *enic,
&ipv6_hdr(skb)->daddr, 0, IPPROTO_TCP, 0);
}
- /* Queue the main skb fragment */
- enic_queue_wq_desc_tso(wq, skb,
- pci_map_single(enic->pdev, skb->data,
- head_len, PCI_DMA_TODEVICE),
- head_len,
- mss, hdr_len,
- vlan_tag_insert, vlan_tag,
- eop);
+ /* Queue WQ_ENET_MAX_DESC_LEN length descriptors
+ * for the main skb fragment
+ */
+ while (frag_len_left) {
+ len = min(frag_len_left, (unsigned int)WQ_ENET_MAX_DESC_LEN);
+ dma_addr = pci_map_single(enic->pdev, skb->data + offset,
+ len, PCI_DMA_TODEVICE);
+ enic_queue_wq_desc_tso(wq, skb,
+ dma_addr,
+ len,
+ mss, hdr_len,
+ vlan_tag_insert, vlan_tag,
+ eop && (len == frag_len_left));
+ frag_len_left -= len;
+ offset += len;
+ }
- if (!eop)
- enic_queue_wq_skb_cont(enic, wq, skb, len_left);
+ if (eop)
+ return;
+
+ /* Queue WQ_ENET_MAX_DESC_LEN length descriptors
+ * for additional data fragments
+ */
+ for (frag = skb_shinfo(skb)->frags; len_left; frag++) {
+ len_left -= frag->size;
+ frag_len_left = frag->size;
+ offset = frag->page_offset;
+
+ while (frag_len_left) {
+ len = min(frag_len_left,
+ (unsigned int)WQ_ENET_MAX_DESC_LEN);
+ dma_addr = pci_map_page(enic->pdev, frag->page,
+ offset, len,
+ PCI_DMA_TODEVICE);
+ enic_queue_wq_desc_cont(wq, skb,
+ dma_addr,
+ len,
+ (len_left == 0) &&
+ (len == frag_len_left)); /* EOP? */
+ frag_len_left -= len;
+ offset += len;
+ }
+ }
}
static inline void enic_queue_wq_skb(struct enic *enic,
@@ -648,7 +698,8 @@ static netdev_tx_t enic_hard_start_xmit(struct sk_buff *skb,
spin_lock_irqsave(&enic->wq_lock[0], flags);
- if (vnic_wq_desc_avail(wq) < skb_shinfo(skb)->nr_frags + 1) {
+ if (vnic_wq_desc_avail(wq) <
+ skb_shinfo(skb)->nr_frags + ENIC_DESC_MAX_SPLITS) {
netif_stop_queue(netdev);
/* This is a hard error, log it */
printk(KERN_ERR PFX "%s: BUG! Tx ring full when "
@@ -659,7 +710,7 @@ static netdev_tx_t enic_hard_start_xmit(struct sk_buff *skb,
enic_queue_wq_skb(enic, wq, skb);
- if (vnic_wq_desc_avail(wq) < MAX_SKB_FRAGS + 1)
+ if (vnic_wq_desc_avail(wq) < MAX_SKB_FRAGS + ENIC_DESC_MAX_SPLITS)
netif_stop_queue(netdev);
spin_unlock_irqrestore(&enic->wq_lock[0], flags);