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authorAlexander Duyck <alexander.h.duyck@intel.com>2012-05-11 08:33:21 +0000
committerJeff Kirsher <jeffrey.t.kirsher@intel.com>2012-07-18 13:16:37 -0700
commit70a10e258ce3d45b294de9190dee9dcc73a495cb (patch)
treee397dbc180b68568d2c6766f9c091ace48cc0db7
parentfb40195cc975b14c5d4e44863ea996f999ba5aee (diff)
ixgbevf: Consolidate Tx context descriptor creation code
There is a good bit of redundancy between the Tx checksum and segmentation offloads. In order to reduce some of this I am moving the code for creating a context descriptor into a separate function. Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Signed-off-by: Greg Rose <gregory.v.rose@intel.com> Tested-by: Sibai Li <sibai.li@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
-rw-r--r--drivers/net/ethernet/intel/ixgbevf/defines.h1
-rw-r--r--drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c342
2 files changed, 163 insertions, 180 deletions
diff --git a/drivers/net/ethernet/intel/ixgbevf/defines.h b/drivers/net/ethernet/intel/ixgbevf/defines.h
index 10cede503fe..418af827b23 100644
--- a/drivers/net/ethernet/intel/ixgbevf/defines.h
+++ b/drivers/net/ethernet/intel/ixgbevf/defines.h
@@ -251,6 +251,7 @@ struct ixgbe_adv_tx_context_desc {
#define IXGBE_ADVTXD_TUCMD_L4T_TCP 0x00000800 /* L4 Packet TYPE of TCP */
#define IXGBE_ADVTXD_TUCMD_L4T_SCTP 0x00001000 /* L4 Packet TYPE of SCTP */
#define IXGBE_ADVTXD_IDX_SHIFT 4 /* Adv desc Index shift */
+#define IXGBE_ADVTXD_CC 0x00000080 /* Check Context */
#define IXGBE_ADVTXD_POPTS_SHIFT 8 /* Adv desc POPTS shift */
#define IXGBE_ADVTXD_POPTS_IXSM (IXGBE_TXD_POPTS_IXSM << \
IXGBE_ADVTXD_POPTS_SHIFT)
diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
index 1c53e13b466..ce81ce0698b 100644
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
@@ -42,6 +42,7 @@
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/tcp.h>
+#include <linux/sctp.h>
#include <linux/ipv6.h>
#include <linux/slab.h>
#include <net/checksum.h>
@@ -144,18 +145,18 @@ static void ixgbevf_set_ivar(struct ixgbevf_adapter *adapter, s8 direction,
}
}
-static void ixgbevf_unmap_and_free_tx_resource(struct ixgbevf_adapter *adapter,
+static void ixgbevf_unmap_and_free_tx_resource(struct ixgbevf_ring *tx_ring,
struct ixgbevf_tx_buffer
*tx_buffer_info)
{
if (tx_buffer_info->dma) {
if (tx_buffer_info->mapped_as_page)
- dma_unmap_page(&adapter->pdev->dev,
+ dma_unmap_page(tx_ring->dev,
tx_buffer_info->dma,
tx_buffer_info->length,
DMA_TO_DEVICE);
else
- dma_unmap_single(&adapter->pdev->dev,
+ dma_unmap_single(tx_ring->dev,
tx_buffer_info->dma,
tx_buffer_info->length,
DMA_TO_DEVICE);
@@ -222,7 +223,7 @@ static bool ixgbevf_clean_tx_irq(struct ixgbevf_q_vector *q_vector,
total_bytes += bytecount;
}
- ixgbevf_unmap_and_free_tx_resource(adapter,
+ ixgbevf_unmap_and_free_tx_resource(tx_ring,
tx_buffer_info);
tx_desc->wb.status = 0;
@@ -1443,7 +1444,7 @@ static void ixgbevf_clean_tx_ring(struct ixgbevf_adapter *adapter,
for (i = 0; i < tx_ring->count; i++) {
tx_buffer_info = &tx_ring->tx_buffer_info[i];
- ixgbevf_unmap_and_free_tx_resource(adapter, tx_buffer_info);
+ ixgbevf_unmap_and_free_tx_resource(tx_ring, tx_buffer_info);
}
size = sizeof(struct ixgbevf_tx_buffer) * tx_ring->count;
@@ -2389,172 +2390,153 @@ static int ixgbevf_close(struct net_device *netdev)
return 0;
}
-static int ixgbevf_tso(struct ixgbevf_adapter *adapter,
- struct ixgbevf_ring *tx_ring,
- struct sk_buff *skb, u32 tx_flags, u8 *hdr_len)
+static void ixgbevf_tx_ctxtdesc(struct ixgbevf_ring *tx_ring,
+ u32 vlan_macip_lens, u32 type_tucmd,
+ u32 mss_l4len_idx)
{
struct ixgbe_adv_tx_context_desc *context_desc;
- unsigned int i;
- int err;
- struct ixgbevf_tx_buffer *tx_buffer_info;
- u32 vlan_macip_lens = 0, type_tucmd_mlhl;
- u32 mss_l4len_idx, l4len;
+ u16 i = tx_ring->next_to_use;
- if (skb_is_gso(skb)) {
- if (skb_header_cloned(skb)) {
- err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
- if (err)
- return err;
- }
- l4len = tcp_hdrlen(skb);
- *hdr_len += l4len;
-
- if (skb->protocol == htons(ETH_P_IP)) {
- struct iphdr *iph = ip_hdr(skb);
- iph->tot_len = 0;
- iph->check = 0;
- tcp_hdr(skb)->check = ~csum_tcpudp_magic(iph->saddr,
- iph->daddr, 0,
- IPPROTO_TCP,
- 0);
- adapter->hw_tso_ctxt++;
- } else if (skb_is_gso_v6(skb)) {
- ipv6_hdr(skb)->payload_len = 0;
- tcp_hdr(skb)->check =
- ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
- &ipv6_hdr(skb)->daddr,
- 0, IPPROTO_TCP, 0);
- adapter->hw_tso6_ctxt++;
- }
+ context_desc = IXGBEVF_TX_CTXTDESC(tx_ring, i);
- i = tx_ring->next_to_use;
+ i++;
+ tx_ring->next_to_use = (i < tx_ring->count) ? i : 0;
- tx_buffer_info = &tx_ring->tx_buffer_info[i];
- context_desc = IXGBEVF_TX_CTXTDESC(tx_ring, i);
-
- /* VLAN MACLEN IPLEN */
- if (tx_flags & IXGBE_TX_FLAGS_VLAN)
- vlan_macip_lens |=
- (tx_flags & IXGBE_TX_FLAGS_VLAN_MASK);
- vlan_macip_lens |= ((skb_network_offset(skb)) <<
- IXGBE_ADVTXD_MACLEN_SHIFT);
- *hdr_len += skb_network_offset(skb);
- vlan_macip_lens |=
- (skb_transport_header(skb) - skb_network_header(skb));
- *hdr_len +=
- (skb_transport_header(skb) - skb_network_header(skb));
- context_desc->vlan_macip_lens = cpu_to_le32(vlan_macip_lens);
- context_desc->seqnum_seed = 0;
-
- /* ADV DTYP TUCMD MKRLOC/ISCSIHEDLEN */
- type_tucmd_mlhl = (IXGBE_TXD_CMD_DEXT |
- IXGBE_ADVTXD_DTYP_CTXT);
-
- if (skb->protocol == htons(ETH_P_IP))
- type_tucmd_mlhl |= IXGBE_ADVTXD_TUCMD_IPV4;
- type_tucmd_mlhl |= IXGBE_ADVTXD_TUCMD_L4T_TCP;
- context_desc->type_tucmd_mlhl = cpu_to_le32(type_tucmd_mlhl);
-
- /* MSS L4LEN IDX */
- mss_l4len_idx =
- (skb_shinfo(skb)->gso_size << IXGBE_ADVTXD_MSS_SHIFT);
- mss_l4len_idx |= (l4len << IXGBE_ADVTXD_L4LEN_SHIFT);
- /* use index 1 for TSO */
- mss_l4len_idx |= (1 << IXGBE_ADVTXD_IDX_SHIFT);
- context_desc->mss_l4len_idx = cpu_to_le32(mss_l4len_idx);
-
- tx_buffer_info->time_stamp = jiffies;
- tx_buffer_info->next_to_watch = i;
+ /* set bits to identify this as an advanced context descriptor */
+ type_tucmd |= IXGBE_TXD_CMD_DEXT | IXGBE_ADVTXD_DTYP_CTXT;
- i++;
- if (i == tx_ring->count)
- i = 0;
- tx_ring->next_to_use = i;
+ context_desc->vlan_macip_lens = cpu_to_le32(vlan_macip_lens);
+ context_desc->seqnum_seed = 0;
+ context_desc->type_tucmd_mlhl = cpu_to_le32(type_tucmd);
+ context_desc->mss_l4len_idx = cpu_to_le32(mss_l4len_idx);
+}
+
+static int ixgbevf_tso(struct ixgbevf_ring *tx_ring,
+ struct sk_buff *skb, u32 tx_flags, u8 *hdr_len)
+{
+ u32 vlan_macip_lens, type_tucmd;
+ u32 mss_l4len_idx, l4len;
+
+ if (!skb_is_gso(skb))
+ return 0;
- return true;
+ if (skb_header_cloned(skb)) {
+ int err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
+ if (err)
+ return err;
}
- return false;
+ /* ADV DTYP TUCMD MKRLOC/ISCSIHEDLEN */
+ type_tucmd = IXGBE_ADVTXD_TUCMD_L4T_TCP;
+
+ if (skb->protocol == htons(ETH_P_IP)) {
+ struct iphdr *iph = ip_hdr(skb);
+ iph->tot_len = 0;
+ iph->check = 0;
+ tcp_hdr(skb)->check = ~csum_tcpudp_magic(iph->saddr,
+ iph->daddr, 0,
+ IPPROTO_TCP,
+ 0);
+ type_tucmd |= IXGBE_ADVTXD_TUCMD_IPV4;
+ } else if (skb_is_gso_v6(skb)) {
+ ipv6_hdr(skb)->payload_len = 0;
+ tcp_hdr(skb)->check =
+ ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
+ &ipv6_hdr(skb)->daddr,
+ 0, IPPROTO_TCP, 0);
+ }
+
+ /* compute header lengths */
+ l4len = tcp_hdrlen(skb);
+ *hdr_len += l4len;
+ *hdr_len = skb_transport_offset(skb) + l4len;
+
+ /* mss_l4len_id: use 1 as index for TSO */
+ mss_l4len_idx = l4len << IXGBE_ADVTXD_L4LEN_SHIFT;
+ mss_l4len_idx |= skb_shinfo(skb)->gso_size << IXGBE_ADVTXD_MSS_SHIFT;
+ mss_l4len_idx |= 1 << IXGBE_ADVTXD_IDX_SHIFT;
+
+ /* vlan_macip_lens: HEADLEN, MACLEN, VLAN tag */
+ vlan_macip_lens = skb_network_header_len(skb);
+ vlan_macip_lens |= skb_network_offset(skb) << IXGBE_ADVTXD_MACLEN_SHIFT;
+ vlan_macip_lens |= tx_flags & IXGBE_TX_FLAGS_VLAN_MASK;
+
+ ixgbevf_tx_ctxtdesc(tx_ring, vlan_macip_lens,
+ type_tucmd, mss_l4len_idx);
+
+ return 1;
}
-static bool ixgbevf_tx_csum(struct ixgbevf_adapter *adapter,
- struct ixgbevf_ring *tx_ring,
+static bool ixgbevf_tx_csum(struct ixgbevf_ring *tx_ring,
struct sk_buff *skb, u32 tx_flags)
{
- struct ixgbe_adv_tx_context_desc *context_desc;
- unsigned int i;
- struct ixgbevf_tx_buffer *tx_buffer_info;
- u32 vlan_macip_lens = 0, type_tucmd_mlhl = 0;
- if (skb->ip_summed == CHECKSUM_PARTIAL ||
- (tx_flags & IXGBE_TX_FLAGS_VLAN)) {
- i = tx_ring->next_to_use;
- tx_buffer_info = &tx_ring->tx_buffer_info[i];
- context_desc = IXGBEVF_TX_CTXTDESC(tx_ring, i);
-
- if (tx_flags & IXGBE_TX_FLAGS_VLAN)
- vlan_macip_lens |= (tx_flags &
- IXGBE_TX_FLAGS_VLAN_MASK);
- vlan_macip_lens |= (skb_network_offset(skb) <<
- IXGBE_ADVTXD_MACLEN_SHIFT);
- if (skb->ip_summed == CHECKSUM_PARTIAL)
- vlan_macip_lens |= (skb_transport_header(skb) -
- skb_network_header(skb));
-
- context_desc->vlan_macip_lens = cpu_to_le32(vlan_macip_lens);
- context_desc->seqnum_seed = 0;
-
- type_tucmd_mlhl |= (IXGBE_TXD_CMD_DEXT |
- IXGBE_ADVTXD_DTYP_CTXT);
-
- if (skb->ip_summed == CHECKSUM_PARTIAL) {
- switch (skb->protocol) {
- case __constant_htons(ETH_P_IP):
- type_tucmd_mlhl |= IXGBE_ADVTXD_TUCMD_IPV4;
- if (ip_hdr(skb)->protocol == IPPROTO_TCP)
- type_tucmd_mlhl |=
- IXGBE_ADVTXD_TUCMD_L4T_TCP;
- break;
- case __constant_htons(ETH_P_IPV6):
- /* XXX what about other V6 headers?? */
- if (ipv6_hdr(skb)->nexthdr == IPPROTO_TCP)
- type_tucmd_mlhl |=
- IXGBE_ADVTXD_TUCMD_L4T_TCP;
- break;
- default:
- if (unlikely(net_ratelimit())) {
- pr_warn("partial checksum but "
- "proto=%x!\n", skb->protocol);
- }
- break;
- }
- }
- context_desc->type_tucmd_mlhl = cpu_to_le32(type_tucmd_mlhl);
- /* use index zero for tx checksum offload */
- context_desc->mss_l4len_idx = 0;
- tx_buffer_info->time_stamp = jiffies;
- tx_buffer_info->next_to_watch = i;
+ u32 vlan_macip_lens = 0;
+ u32 mss_l4len_idx = 0;
+ u32 type_tucmd = 0;
- adapter->hw_csum_tx_good++;
- i++;
- if (i == tx_ring->count)
- i = 0;
- tx_ring->next_to_use = i;
+ if (skb->ip_summed == CHECKSUM_PARTIAL) {
+ u8 l4_hdr = 0;
+ switch (skb->protocol) {
+ case __constant_htons(ETH_P_IP):
+ vlan_macip_lens |= skb_network_header_len(skb);
+ type_tucmd |= IXGBE_ADVTXD_TUCMD_IPV4;
+ l4_hdr = ip_hdr(skb)->protocol;
+ break;
+ case __constant_htons(ETH_P_IPV6):
+ vlan_macip_lens |= skb_network_header_len(skb);
+ l4_hdr = ipv6_hdr(skb)->nexthdr;
+ break;
+ default:
+ if (unlikely(net_ratelimit())) {
+ dev_warn(tx_ring->dev,
+ "partial checksum but proto=%x!\n",
+ skb->protocol);
+ }
+ break;
+ }
- return true;
+ switch (l4_hdr) {
+ case IPPROTO_TCP:
+ type_tucmd |= IXGBE_ADVTXD_TUCMD_L4T_TCP;
+ mss_l4len_idx = tcp_hdrlen(skb) <<
+ IXGBE_ADVTXD_L4LEN_SHIFT;
+ break;
+ case IPPROTO_SCTP:
+ type_tucmd |= IXGBE_ADVTXD_TUCMD_L4T_SCTP;
+ mss_l4len_idx = sizeof(struct sctphdr) <<
+ IXGBE_ADVTXD_L4LEN_SHIFT;
+ break;
+ case IPPROTO_UDP:
+ mss_l4len_idx = sizeof(struct udphdr) <<
+ IXGBE_ADVTXD_L4LEN_SHIFT;
+ break;
+ default:
+ if (unlikely(net_ratelimit())) {
+ dev_warn(tx_ring->dev,
+ "partial checksum but l4 proto=%x!\n",
+ l4_hdr);
+ }
+ break;
+ }
}
- return false;
+ /* vlan_macip_lens: MACLEN, VLAN tag */
+ vlan_macip_lens |= skb_network_offset(skb) << IXGBE_ADVTXD_MACLEN_SHIFT;
+ vlan_macip_lens |= tx_flags & IXGBE_TX_FLAGS_VLAN_MASK;
+
+ ixgbevf_tx_ctxtdesc(tx_ring, vlan_macip_lens,
+ type_tucmd, mss_l4len_idx);
+
+ return (skb->ip_summed == CHECKSUM_PARTIAL);
}
-static int ixgbevf_tx_map(struct ixgbevf_adapter *adapter,
- struct ixgbevf_ring *tx_ring,
+static int ixgbevf_tx_map(struct ixgbevf_ring *tx_ring,
struct sk_buff *skb, u32 tx_flags,
unsigned int first)
{
- struct pci_dev *pdev = adapter->pdev;
struct ixgbevf_tx_buffer *tx_buffer_info;
unsigned int len;
unsigned int total = skb->len;
@@ -2573,12 +2555,11 @@ static int ixgbevf_tx_map(struct ixgbevf_adapter *adapter,
tx_buffer_info->length = size;
tx_buffer_info->mapped_as_page = false;
- tx_buffer_info->dma = dma_map_single(&adapter->pdev->dev,
+ tx_buffer_info->dma = dma_map_single(tx_ring->dev,
skb->data + offset,
size, DMA_TO_DEVICE);
- if (dma_mapping_error(&pdev->dev, tx_buffer_info->dma))
+ if (dma_mapping_error(tx_ring->dev, tx_buffer_info->dma))
goto dma_error;
- tx_buffer_info->time_stamp = jiffies;
tx_buffer_info->next_to_watch = i;
len -= size;
@@ -2603,12 +2584,12 @@ static int ixgbevf_tx_map(struct ixgbevf_adapter *adapter,
tx_buffer_info->length = size;
tx_buffer_info->dma =
- skb_frag_dma_map(&adapter->pdev->dev, frag,
+ skb_frag_dma_map(tx_ring->dev, frag,
offset, size, DMA_TO_DEVICE);
tx_buffer_info->mapped_as_page = true;
- if (dma_mapping_error(&pdev->dev, tx_buffer_info->dma))
+ if (dma_mapping_error(tx_ring->dev,
+ tx_buffer_info->dma))
goto dma_error;
- tx_buffer_info->time_stamp = jiffies;
tx_buffer_info->next_to_watch = i;
len -= size;
@@ -2629,15 +2610,15 @@ static int ixgbevf_tx_map(struct ixgbevf_adapter *adapter,
i = i - 1;
tx_ring->tx_buffer_info[i].skb = skb;
tx_ring->tx_buffer_info[first].next_to_watch = i;
+ tx_ring->tx_buffer_info[first].time_stamp = jiffies;
return count;
dma_error:
- dev_err(&pdev->dev, "TX DMA map failed\n");
+ dev_err(tx_ring->dev, "TX DMA map failed\n");
/* clear timestamp and dma mappings for failed tx_buffer_info map */
tx_buffer_info->dma = 0;
- tx_buffer_info->time_stamp = 0;
tx_buffer_info->next_to_watch = 0;
count--;
@@ -2648,14 +2629,13 @@ dma_error:
if (i < 0)
i += tx_ring->count;
tx_buffer_info = &tx_ring->tx_buffer_info[i];
- ixgbevf_unmap_and_free_tx_resource(adapter, tx_buffer_info);
+ ixgbevf_unmap_and_free_tx_resource(tx_ring, tx_buffer_info);
}
return count;
}
-static void ixgbevf_tx_queue(struct ixgbevf_adapter *adapter,
- struct ixgbevf_ring *tx_ring, int tx_flags,
+static void ixgbevf_tx_queue(struct ixgbevf_ring *tx_ring, int tx_flags,
int count, u32 paylen, u8 hdr_len)
{
union ixgbe_adv_tx_desc *tx_desc = NULL;
@@ -2672,21 +2652,24 @@ static void ixgbevf_tx_queue(struct ixgbevf_adapter *adapter,
if (tx_flags & IXGBE_TX_FLAGS_VLAN)
cmd_type_len |= IXGBE_ADVTXD_DCMD_VLE;
+ if (tx_flags & IXGBE_TX_FLAGS_CSUM)
+ olinfo_status |= IXGBE_ADVTXD_POPTS_TXSM;
+
if (tx_flags & IXGBE_TX_FLAGS_TSO) {
cmd_type_len |= IXGBE_ADVTXD_DCMD_TSE;
- olinfo_status |= IXGBE_TXD_POPTS_TXSM <<
- IXGBE_ADVTXD_POPTS_SHIFT;
-
/* use index 1 context for tso */
olinfo_status |= (1 << IXGBE_ADVTXD_IDX_SHIFT);
if (tx_flags & IXGBE_TX_FLAGS_IPV4)
- olinfo_status |= IXGBE_TXD_POPTS_IXSM <<
- IXGBE_ADVTXD_POPTS_SHIFT;
+ olinfo_status |= IXGBE_ADVTXD_POPTS_IXSM;
+
+ }
- } else if (tx_flags & IXGBE_TX_FLAGS_CSUM)
- olinfo_status |= IXGBE_TXD_POPTS_TXSM <<
- IXGBE_ADVTXD_POPTS_SHIFT;
+ /*
+ * Check Context must be set if Tx switch is enabled, which it
+ * always is for case where virtual functions are running
+ */
+ olinfo_status |= IXGBE_ADVTXD_CC;
olinfo_status |= ((paylen - hdr_len) << IXGBE_ADVTXD_PAYLEN_SHIFT);
@@ -2705,16 +2688,7 @@ static void ixgbevf_tx_queue(struct ixgbevf_adapter *adapter,
tx_desc->read.cmd_type_len |= cpu_to_le32(txd_cmd);
- /*
- * Force memory writes to complete before letting h/w
- * know there are new descriptors to fetch. (Only
- * applicable for weak-ordered memory model archs,
- * such as IA-64).
- */
- wmb();
-
tx_ring->next_to_use = i;
- writel(i, adapter->hw.hw_addr + tx_ring->tail);
}
static int __ixgbevf_maybe_stop_tx(struct ixgbevf_ring *tx_ring, int size)
@@ -2788,21 +2762,29 @@ static int ixgbevf_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
if (skb->protocol == htons(ETH_P_IP))
tx_flags |= IXGBE_TX_FLAGS_IPV4;
- tso = ixgbevf_tso(adapter, tx_ring, skb, tx_flags, &hdr_len);
+ tso = ixgbevf_tso(tx_ring, skb, tx_flags, &hdr_len);
if (tso < 0) {
dev_kfree_skb_any(skb);
return NETDEV_TX_OK;
}
if (tso)
- tx_flags |= IXGBE_TX_FLAGS_TSO;
- else if (ixgbevf_tx_csum(adapter, tx_ring, skb, tx_flags) &&
- (skb->ip_summed == CHECKSUM_PARTIAL))
+ tx_flags |= IXGBE_TX_FLAGS_TSO | IXGBE_TX_FLAGS_CSUM;
+ else if (ixgbevf_tx_csum(tx_ring, skb, tx_flags))
tx_flags |= IXGBE_TX_FLAGS_CSUM;
- ixgbevf_tx_queue(adapter, tx_ring, tx_flags,
- ixgbevf_tx_map(adapter, tx_ring, skb, tx_flags, first),
+ ixgbevf_tx_queue(tx_ring, tx_flags,
+ ixgbevf_tx_map(tx_ring, skb, tx_flags, first),
skb->len, hdr_len);
+ /*
+ * Force memory writes to complete before letting h/w
+ * know there are new descriptors to fetch. (Only
+ * applicable for weak-ordered memory model archs,
+ * such as IA-64).
+ */
+ wmb();
+
+ writel(tx_ring->next_to_use, adapter->hw.hw_addr + tx_ring->tail);
ixgbevf_maybe_stop_tx(tx_ring, DESC_NEEDED);