ixgbe: add support to FCoE DDP in target mode

Add support to the ndo_fcoe_ddp_target() to allow the Intel 82599 device to
also provide DDP offload capability when the upper FCoE protocol stack is
operating as a target.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Kiran Patil <kiran.patil@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

4 files changed, 81 insertions, 12 deletions

diff --git a/drivers/net/ixgbe/ixgbe.h b/drivers/net/ixgbe/ixgbe.h
index b60b81bc2b15..1e546fc127d0 100644
--- a/drivers/net/ixgbe/ixgbe.h
+++ b/drivers/net/ixgbe/ixgbe.h
@@ -552,6 +552,8 @@ extern int ixgbe_fcoe_ddp(struct ixgbe_adapter *adapter,
                           struct sk_buff *skb);
 extern int ixgbe_fcoe_ddp_get(struct net_device *netdev, u16 xid,
                               struct scatterlist *sgl, unsigned int sgc);
+extern int ixgbe_fcoe_ddp_target(struct net_device *netdev, u16 xid,
+                                 struct scatterlist *sgl, unsigned int sgc);
 extern int ixgbe_fcoe_ddp_put(struct net_device *netdev, u16 xid);
 extern int ixgbe_fcoe_enable(struct net_device *netdev);
 extern int ixgbe_fcoe_disable(struct net_device *netdev);
diff --git a/drivers/net/ixgbe/ixgbe_fcoe.c b/drivers/net/ixgbe/ixgbe_fcoe.c
index 27203c87ea14..00af15a9cdc6 100644
--- a/drivers/net/ixgbe/ixgbe_fcoe.c
+++ b/drivers/net/ixgbe/ixgbe_fcoe.c
@@ -135,22 +135,19 @@ out_ddp_put:
         return len;
 }
 
+
 /**
- * ixgbe_fcoe_ddp_get - called to set up ddp context
+ * ixgbe_fcoe_ddp_setup - called to set up ddp context
  * @netdev: the corresponding net_device
  * @xid: the exchange id requesting ddp
  * @sgl: the scatter-gather list for this request
  * @sgc: the number of scatter-gather items
  *
- * This is the implementation of net_device_ops.ndo_fcoe_ddp_setup
- * and is expected to be called from ULD, e.g., FCP layer of libfc
- * to set up ddp for the corresponding xid of the given sglist for
- * the corresponding I/O.
- *
  * Returns : 1 for success and 0 for no ddp
  */
-int ixgbe_fcoe_ddp_get(struct net_device *netdev, u16 xid,
-                       struct scatterlist *sgl, unsigned int sgc)
+static int ixgbe_fcoe_ddp_setup(struct net_device *netdev, u16 xid,
+                                struct scatterlist *sgl, unsigned int sgc,
+                                int target_mode)
 {
         struct ixgbe_adapter *adapter;
         struct ixgbe_hw *hw;
@@ -164,7 +161,7 @@ int ixgbe_fcoe_ddp_get(struct net_device *netdev, u16 xid,
         unsigned int lastsize;
         unsigned int thisoff = 0;
         unsigned int thislen = 0;
-        u32 fcbuff, fcdmarw, fcfltrw;
+        u32 fcbuff, fcdmarw, fcfltrw, fcrxctl;
         dma_addr_t addr = 0;
 
         if (!netdev || !sgl)
@@ -275,6 +272,9 @@ int ixgbe_fcoe_ddp_get(struct net_device *netdev, u16 xid,
         fcbuff = (IXGBE_FCBUFF_4KB << IXGBE_FCBUFF_BUFFSIZE_SHIFT);
         fcbuff |= ((j & 0xff) << IXGBE_FCBUFF_BUFFCNT_SHIFT);
         fcbuff |= (firstoff << IXGBE_FCBUFF_OFFSET_SHIFT);
+        /* Set WRCONTX bit to allow DDP for target */
+        if (target_mode)
+                fcbuff |= (IXGBE_FCBUFF_WRCONTX);
         fcbuff |= (IXGBE_FCBUFF_VALID);
 
         fcdmarw = xid;
@@ -287,6 +287,16 @@ int ixgbe_fcoe_ddp_get(struct net_device *netdev, u16 xid,
         /* program DMA context */
         hw = &adapter->hw;
         spin_lock_bh(&fcoe->lock);
+
+        /* turn on last frame indication for target mode as FCP_RSPtarget is
+         * supposed to send FCP_RSP when it is done. */
+        if (target_mode && !test_bit(__IXGBE_FCOE_TARGET, &fcoe->mode)) {
+                set_bit(__IXGBE_FCOE_TARGET, &fcoe->mode);
+                fcrxctl = IXGBE_READ_REG(hw, IXGBE_FCRXCTRL);
+                fcrxctl |= IXGBE_FCRXCTRL_LASTSEQH;
+                IXGBE_WRITE_REG(hw, IXGBE_FCRXCTRL, fcrxctl);
+        }
+
         IXGBE_WRITE_REG(hw, IXGBE_FCPTRL, ddp->udp & DMA_BIT_MASK(32));
         IXGBE_WRITE_REG(hw, IXGBE_FCPTRH, (u64)ddp->udp >> 32);
         IXGBE_WRITE_REG(hw, IXGBE_FCBUFF, fcbuff);
@@ -295,6 +305,7 @@ int ixgbe_fcoe_ddp_get(struct net_device *netdev, u16 xid,
         IXGBE_WRITE_REG(hw, IXGBE_FCPARAM, 0);
         IXGBE_WRITE_REG(hw, IXGBE_FCFLT, IXGBE_FCFLT_VALID);
         IXGBE_WRITE_REG(hw, IXGBE_FCFLTRW, fcfltrw);
+
         spin_unlock_bh(&fcoe->lock);
 
         return 1;
@@ -309,6 +320,47 @@ out_noddp_unmap:
 }
 
 /**
+ * ixgbe_fcoe_ddp_get - called to set up ddp context in initiator mode
+ * @netdev: the corresponding net_device
+ * @xid: the exchange id requesting ddp
+ * @sgl: the scatter-gather list for this request
+ * @sgc: the number of scatter-gather items
+ *
+ * This is the implementation of net_device_ops.ndo_fcoe_ddp_setup
+ * and is expected to be called from ULD, e.g., FCP layer of libfc
+ * to set up ddp for the corresponding xid of the given sglist for
+ * the corresponding I/O.
+ *
+ * Returns : 1 for success and 0 for no ddp
+ */
+int ixgbe_fcoe_ddp_get(struct net_device *netdev, u16 xid,
+                       struct scatterlist *sgl, unsigned int sgc)
+{
+        return ixgbe_fcoe_ddp_setup(netdev, xid, sgl, sgc, 0);
+}
+
+/**
+ * ixgbe_fcoe_ddp_target - called to set up ddp context in target mode
+ * @netdev: the corresponding net_device
+ * @xid: the exchange id requesting ddp
+ * @sgl: the scatter-gather list for this request
+ * @sgc: the number of scatter-gather items
+ *
+ * This is the implementation of net_device_ops.ndo_fcoe_ddp_target
+ * and is expected to be called from ULD, e.g., FCP layer of libfc
+ * to set up ddp for the corresponding xid of the given sglist for
+ * the corresponding I/O. The DDP in target mode is a write I/O request
+ * from the initiator.
+ *
+ * Returns : 1 for success and 0 for no ddp
+ */
+int ixgbe_fcoe_ddp_target(struct net_device *netdev, u16 xid,
+                            struct scatterlist *sgl, unsigned int sgc)
+{
+        return ixgbe_fcoe_ddp_setup(netdev, xid, sgl, sgc, 1);
+}
+
+/**
  * ixgbe_fcoe_ddp - check ddp status and mark it done
  * @adapter: ixgbe adapter
  * @rx_desc: advanced rx descriptor
@@ -331,6 +383,7 @@ int ixgbe_fcoe_ddp(struct ixgbe_adapter *adapter,
         struct ixgbe_fcoe *fcoe;
         struct ixgbe_fcoe_ddp *ddp;
         struct fc_frame_header *fh;
+        struct fcoe_crc_eof *crc;
 
         if (!ixgbe_rx_is_fcoe(rx_desc))
                 goto ddp_out;
@@ -384,7 +437,18 @@ int ixgbe_fcoe_ddp(struct ixgbe_adapter *adapter,
                 else if (ddp->len)
                         rc = ddp->len;
         }
-
+        /* In target mode, check the last data frame of the sequence.
+         * For DDP in target mode, data is already DDPed but the header
+         * indication of the last data frame ould allow is to tell if we
+         * got all the data and the ULP can send FCP_RSP back, as this is
+         * not a full fcoe frame, we fill the trailer here so it won't be
+         * dropped by the ULP stack.
+         */
+        if ((fh->fh_r_ctl == FC_RCTL_DD_SOL_DATA) &&
+            (fctl & FC_FC_END_SEQ)) {
+                crc = (struct fcoe_crc_eof *)skb_put(skb, sizeof(*crc));
+                crc->fcoe_eof = FC_EOF_T;
+        }
 ddp_out:
         return rc;
 }
@@ -840,5 +904,3 @@ int ixgbe_fcoe_get_wwn(struct net_device *netdev, u64 *wwn, int type)
         }
         return rc;
 }
-
-
diff --git a/drivers/net/ixgbe/ixgbe_fcoe.h b/drivers/net/ixgbe/ixgbe_fcoe.h
index 02a00d2415d9..5a650a4ace66 100644
--- a/drivers/net/ixgbe/ixgbe_fcoe.h
+++ b/drivers/net/ixgbe/ixgbe_fcoe.h
@@ -52,6 +52,9 @@
 /* fcerr */
 #define IXGBE_FCERR_BADCRC       0x00100000
 
+/* FCoE DDP for target mode */
+#define __IXGBE_FCOE_TARGET     1
+
 struct ixgbe_fcoe_ddp {
         int len;
         u32 err;
@@ -66,6 +69,7 @@ struct ixgbe_fcoe {
         u8 tc;
         u8 up;
 #endif
+        unsigned long mode;
         atomic_t refcnt;
         spinlock_t lock;
         struct pci_pool *pool;
diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c
index 32231ffe0717..5e8c39decca1 100644
--- a/drivers/net/ixgbe/ixgbe_main.c
+++ b/drivers/net/ixgbe/ixgbe_main.c
@@ -7019,6 +7019,7 @@ static const struct net_device_ops ixgbe_netdev_ops = {
 #endif
 #ifdef IXGBE_FCOE
         .ndo_fcoe_ddp_setup = ixgbe_fcoe_ddp_get,
+        .ndo_fcoe_ddp_target = ixgbe_fcoe_ddp_target,
         .ndo_fcoe_ddp_done = ixgbe_fcoe_ddp_put,
         .ndo_fcoe_enable = ixgbe_fcoe_enable,
         .ndo_fcoe_disable = ixgbe_fcoe_disable,