enic: Feature Add: Add loopback capability to enic devices

Hardware has the loopback capability to queue the packets transmitted from
a device to the receive queue of the same device. enic now supports the
loopback capability.

Signed-off-by: Scott Feldman <scofeldm@cisco.com>
Signed-off-by: Vasanthy Kolluri <vkolluri@cisco.com>
Signed-off-by: Roopa Prabhu <roprabhu@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 45 insertions, 27 deletions

diff --git a/drivers/net/enic/enic.h b/drivers/net/enic/enic.h
index 3588ef5e7e4c..7280314804a3 100644
--- a/drivers/net/enic/enic.h
+++ b/drivers/net/enic/enic.h
@@ -110,6 +110,8 @@ struct enic {
         spinlock_t wq_lock[ENIC_WQ_MAX];
         unsigned int wq_count;
         struct vlan_group *vlan_group;
+        u16 loop_enable;
+        u16 loop_tag;
 
         /* receive queue cache line section */
         ____cacheline_aligned struct vnic_rq rq[ENIC_RQ_MAX];
diff --git a/drivers/net/enic/enic_main.c b/drivers/net/enic/enic_main.c
index 413e362e3275..eda5530004dc 100644
--- a/drivers/net/enic/enic_main.c
+++ b/drivers/net/enic/enic_main.c
@@ -594,7 +594,7 @@ static irqreturn_t enic_isr_msix_notify(int irq, void *data)
 
 static inline void enic_queue_wq_skb_cont(struct enic *enic,
         struct vnic_wq *wq, struct sk_buff *skb,
-        unsigned int len_left)
+        unsigned int len_left, int loopback)
 {
         skb_frag_t *frag;
 
@@ -606,13 +606,14 @@ static inline void enic_queue_wq_skb_cont(struct enic *enic,
                                 frag->page_offset, frag->size,
                                 PCI_DMA_TODEVICE),
                         frag->size,
-                        (len_left == 0));       /* EOP? */
+                        (len_left == 0),        /* EOP? */
+                        loopback);
         }
 }
 
 static inline void enic_queue_wq_skb_vlan(struct enic *enic,
         struct vnic_wq *wq, struct sk_buff *skb,
-        int vlan_tag_insert, unsigned int vlan_tag)
+        int vlan_tag_insert, unsigned int vlan_tag, int loopback)
 {
         unsigned int head_len = skb_headlen(skb);
         unsigned int len_left = skb->len - head_len;
@@ -628,15 +629,15 @@ static inline void enic_queue_wq_skb_vlan(struct enic *enic,
                         head_len, PCI_DMA_TODEVICE),
                 head_len,
                 vlan_tag_insert, vlan_tag,
-                eop);
+                eop, loopback);
 
         if (!eop)
-                enic_queue_wq_skb_cont(enic, wq, skb, len_left);
+                enic_queue_wq_skb_cont(enic, wq, skb, len_left, loopback);
 }
 
 static inline void enic_queue_wq_skb_csum_l4(struct enic *enic,
         struct vnic_wq *wq, struct sk_buff *skb,
-        int vlan_tag_insert, unsigned int vlan_tag)
+        int vlan_tag_insert, unsigned int vlan_tag, int loopback)
 {
         unsigned int head_len = skb_headlen(skb);
         unsigned int len_left = skb->len - head_len;
@@ -656,15 +657,15 @@ static inline void enic_queue_wq_skb_csum_l4(struct enic *enic,
                 csum_offset,
                 hdr_len,
                 vlan_tag_insert, vlan_tag,
-                eop);
+                eop, loopback);
 
         if (!eop)
-                enic_queue_wq_skb_cont(enic, wq, skb, len_left);
+                enic_queue_wq_skb_cont(enic, wq, skb, len_left, loopback);
 }
 
 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)
+        int vlan_tag_insert, unsigned int vlan_tag, int loopback)
 {
         unsigned int frag_len_left = skb_headlen(skb);
         unsigned int len_left = skb->len - frag_len_left;
@@ -701,7 +702,7 @@ static inline void enic_queue_wq_skb_tso(struct enic *enic,
                         len,
                         mss, hdr_len,
                         vlan_tag_insert, vlan_tag,
-                        eop && (len == frag_len_left));
+                        eop && (len == frag_len_left), loopback);
                 frag_len_left -= len;
                 offset += len;
         }
@@ -727,7 +728,8 @@ static inline void enic_queue_wq_skb_tso(struct enic *enic,
                                 dma_addr,
                                 len,
                                 (len_left == 0) &&
-                                (len == frag_len_left));        /* EOP? */
+                                (len == frag_len_left),         /* EOP? */
+                                loopback);
                         frag_len_left -= len;
                         offset += len;
                 }
@@ -740,22 +742,26 @@ static inline void enic_queue_wq_skb(struct enic *enic,
         unsigned int mss = skb_shinfo(skb)->gso_size;
         unsigned int vlan_tag = 0;
         int vlan_tag_insert = 0;
+        int loopback = 0;
 
         if (enic->vlan_group && vlan_tx_tag_present(skb)) {
                 /* VLAN tag from trunking driver */
                 vlan_tag_insert = 1;
                 vlan_tag = vlan_tx_tag_get(skb);
+        } else if (enic->loop_enable) {
+                vlan_tag = enic->loop_tag;
+                loopback = 1;
         }
 
         if (mss)
                 enic_queue_wq_skb_tso(enic, wq, skb, mss,
-                        vlan_tag_insert, vlan_tag);
+                        vlan_tag_insert, vlan_tag, loopback);
         else if (skb->ip_summed == CHECKSUM_PARTIAL)
                 enic_queue_wq_skb_csum_l4(enic, wq, skb,
-                        vlan_tag_insert, vlan_tag);
+                        vlan_tag_insert, vlan_tag, loopback);
         else
                 enic_queue_wq_skb_vlan(enic, wq, skb,
-                        vlan_tag_insert, vlan_tag);
+                        vlan_tag_insert, vlan_tag, loopback);
 }
 
 /* netif_tx_lock held, process context with BHs disabled, or BH */
@@ -1275,7 +1281,7 @@ static int enic_rq_alloc_buf(struct vnic_rq *rq)
         struct enic *enic = vnic_dev_priv(rq->vdev);
         struct net_device *netdev = enic->netdev;
         struct sk_buff *skb;
-        unsigned int len = netdev->mtu + ETH_HLEN;
+        unsigned int len = netdev->mtu + VLAN_ETH_HLEN;
         unsigned int os_buf_index = 0;
         dma_addr_t dma_addr;
 
@@ -2441,6 +2447,12 @@ static int __devinit enic_probe(struct pci_dev *pdev,
         netdev->ethtool_ops = &enic_ethtool_ops;
 
         netdev->features |= NETIF_F_HW_VLAN_TX | NETIF_F_HW_VLAN_RX;
+        if (ENIC_SETTING(enic, LOOP)) {
+                netdev->features &= ~NETIF_F_HW_VLAN_TX;
+                enic->loop_enable = 1;
+                enic->loop_tag = enic->config.loop_tag;
+                dev_info(dev, "loopback tag=0x%04x\n", enic->loop_tag);
+        }
         if (ENIC_SETTING(enic, TXCSUM))
                 netdev->features |= NETIF_F_SG | NETIF_F_HW_CSUM;
         if (ENIC_SETTING(enic, TSO))
diff --git a/drivers/net/enic/enic_res.c b/drivers/net/enic/enic_res.c
index 478928b7cc09..2cc7e278caae 100644
--- a/drivers/net/enic/enic_res.c
+++ b/drivers/net/enic/enic_res.c
@@ -70,6 +70,7 @@ int enic_get_vnic_config(struct enic *enic)
         GET_CONFIG(intr_timer_type);
         GET_CONFIG(intr_mode);
         GET_CONFIG(intr_timer_usec);
+        GET_CONFIG(loop_tag);
 
         c->wq_desc_count =
                 min_t(u32, ENIC_MAX_WQ_DESCS,
diff --git a/drivers/net/enic/enic_res.h b/drivers/net/enic/enic_res.h
index 3f6e039c2fd2..8b25a07a67d1 100644
--- a/drivers/net/enic/enic_res.h
+++ b/drivers/net/enic/enic_res.h
@@ -43,7 +43,7 @@ static inline void enic_queue_wq_desc_ex(struct vnic_wq *wq,
         void *os_buf, dma_addr_t dma_addr, unsigned int len,
         unsigned int mss_or_csum_offset, unsigned int hdr_len,
         int vlan_tag_insert, unsigned int vlan_tag,
-        int offload_mode, int cq_entry, int sop, int eop)
+        int offload_mode, int cq_entry, int sop, int eop, int loopback)
 {
         struct wq_enet_desc *desc = vnic_wq_next_desc(wq);
 
@@ -56,61 +56,62 @@ static inline void enic_queue_wq_desc_ex(struct vnic_wq *wq,
                 0, /* fcoe_encap */
                 (u8)vlan_tag_insert,
                 (u16)vlan_tag,
-                0 /* loopback */);
+                (u8)loopback);
 
         vnic_wq_post(wq, os_buf, dma_addr, len, sop, eop);
 }
 
 static inline void enic_queue_wq_desc_cont(struct vnic_wq *wq,
-        void *os_buf, dma_addr_t dma_addr, unsigned int len, int eop)
+        void *os_buf, dma_addr_t dma_addr, unsigned int len,
+        int eop, int loopback)
 {
         enic_queue_wq_desc_ex(wq, os_buf, dma_addr, len,
                 0, 0, 0, 0, 0,
-                eop, 0 /* !SOP */, eop);
+                eop, 0 /* !SOP */, eop, loopback);
 }
 
 static inline void enic_queue_wq_desc(struct vnic_wq *wq, void *os_buf,
         dma_addr_t dma_addr, unsigned int len, int vlan_tag_insert,
-        unsigned int vlan_tag, int eop)
+        unsigned int vlan_tag, int eop, int loopback)
 {
         enic_queue_wq_desc_ex(wq, os_buf, dma_addr, len,
                 0, 0, vlan_tag_insert, vlan_tag,
                 WQ_ENET_OFFLOAD_MODE_CSUM,
-                eop, 1 /* SOP */, eop);
+                eop, 1 /* SOP */, eop, loopback);
 }
 
 static inline void enic_queue_wq_desc_csum(struct vnic_wq *wq,
         void *os_buf, dma_addr_t dma_addr, unsigned int len,
         int ip_csum, int tcpudp_csum, int vlan_tag_insert,
-        unsigned int vlan_tag, int eop)
+        unsigned int vlan_tag, int eop, int loopback)
 {
         enic_queue_wq_desc_ex(wq, os_buf, dma_addr, len,
                 (ip_csum ? 1 : 0) + (tcpudp_csum ? 2 : 0),
                 0, vlan_tag_insert, vlan_tag,
                 WQ_ENET_OFFLOAD_MODE_CSUM,
-                eop, 1 /* SOP */, eop);
+                eop, 1 /* SOP */, eop, loopback);
 }
 
 static inline void enic_queue_wq_desc_csum_l4(struct vnic_wq *wq,
         void *os_buf, dma_addr_t dma_addr, unsigned int len,
         unsigned int csum_offset, unsigned int hdr_len,
-        int vlan_tag_insert, unsigned int vlan_tag, int eop)
+        int vlan_tag_insert, unsigned int vlan_tag, int eop, int loopback)
 {
         enic_queue_wq_desc_ex(wq, os_buf, dma_addr, len,
                 csum_offset, hdr_len, vlan_tag_insert, vlan_tag,
                 WQ_ENET_OFFLOAD_MODE_CSUM_L4,
-                eop, 1 /* SOP */, eop);
+                eop, 1 /* SOP */, eop, loopback);
 }
 
 static inline void enic_queue_wq_desc_tso(struct vnic_wq *wq,
         void *os_buf, dma_addr_t dma_addr, unsigned int len,
         unsigned int mss, unsigned int hdr_len, int vlan_tag_insert,
-        unsigned int vlan_tag, int eop)
+        unsigned int vlan_tag, int eop, int loopback)
 {
         enic_queue_wq_desc_ex(wq, os_buf, dma_addr, len,
                 mss, hdr_len, vlan_tag_insert, vlan_tag,
                 WQ_ENET_OFFLOAD_MODE_TSO,
-                eop, 1 /* SOP */, eop);
+                eop, 1 /* SOP */, eop, loopback);
 }
 
 static inline void enic_queue_rq_desc(struct vnic_rq *rq,
diff --git a/drivers/net/enic/vnic_enet.h b/drivers/net/enic/vnic_enet.h
index 8eeb6758491b..42baaa13ce59 100644
--- a/drivers/net/enic/vnic_enet.h
+++ b/drivers/net/enic/vnic_enet.h
@@ -35,6 +35,7 @@ struct vnic_enet_config {
         u8 intr_mode;
         char devname[16];
         u32 intr_timer_usec;
+        u16 loop_tag;
 };
 
 #define VENETF_TSO              0x1     /* TSO enabled */
@@ -48,5 +49,6 @@ struct vnic_enet_config {
 #define VENETF_RSSHASH_TCPIPV6  0x100   /* Hash on TCP + IPv6 fields */
 #define VENETF_RSSHASH_IPV6_EX  0x200   /* Hash on IPv6 extended fields */
 #define VENETF_RSSHASH_TCPIPV6_EX 0x400 /* Hash on TCP + IPv6 ext. fields */
+#define VENETF_LOOP             0x800   /* Loopback enabled */
 
 #endif /* _VNIC_ENIC_H_ */