From: Magnus Karlsson <magnus.karlsson@intel.com>
Date: Tue, 28 Aug 2018 14:44:33 +0200
Subject: i40e: move common Tx functions to i40e_txrx_common.h
Patch-mainline: v4.20-rc1
Git-commit: a96e7472732842d76af0132c5f87f531f312d7a9
References: bsc#1111981 FATE#326312 FATE#326313

This patch prepares for the upcoming zero-copy Tx functionality, by
moving common functions and refactor chunks of code into re-usable
functions, used both by the regular path and zero-copy path.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/intel/i40e/i40e_txrx.c        |   35 ------------
 drivers/net/ethernet/intel/i40e/i40e_txrx_common.h |   59 +++++++++++++++++++++
 2 files changed, 61 insertions(+), 33 deletions(-)

--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -34,16 +34,6 @@
 #include "i40e_txrx_common.h"
 #include "i40e_xsk.h"
 
-static inline __le64 build_ctob(u32 td_cmd, u32 td_offset, unsigned int size,
-				u32 td_tag)
-{
-	return cpu_to_le64(I40E_TX_DESC_DTYPE_DATA |
-			   ((u64)td_cmd  << I40E_TXD_QW1_CMD_SHIFT) |
-			   ((u64)td_offset << I40E_TXD_QW1_OFFSET_SHIFT) |
-			   ((u64)size  << I40E_TXD_QW1_TX_BUF_SZ_SHIFT) |
-			   ((u64)td_tag  << I40E_TXD_QW1_L2TAG1_SHIFT));
-}
-
 #define I40E_TXD_CMD (I40E_TX_DESC_CMD_EOP | I40E_TX_DESC_CMD_RS)
 /**
  * i40e_fdir - Generate a Flow Director descriptor based on fdata
@@ -792,8 +782,6 @@ void i40e_detect_recover_hung(struct i40
 	}
 }
 
-#define WB_STRIDE 4
-
 /**
  * i40e_clean_tx_irq - Reclaim resources after transmit completes
  * @vsi: the VSI we care about
@@ -898,27 +886,8 @@ static bool i40e_clean_tx_irq(struct i40
 
 	i += tx_ring->count;
 	tx_ring->next_to_clean = i;
-	u64_stats_update_begin(&tx_ring->syncp);
-	tx_ring->stats.bytes += total_bytes;
-	tx_ring->stats.packets += total_packets;
-	u64_stats_update_end(&tx_ring->syncp);
-	tx_ring->q_vector->tx.total_bytes += total_bytes;
-	tx_ring->q_vector->tx.total_packets += total_packets;
-
-	if (tx_ring->flags & I40E_TXR_FLAGS_WB_ON_ITR) {
-		/* check to see if there are < 4 descriptors
-		 * waiting to be written back, then kick the hardware to force
-		 * them to be written back in case we stay in NAPI.
-		 * In this mode on X722 we do not enable Interrupt.
-		 */
-		unsigned int j = i40e_get_tx_pending(tx_ring, false);
-
-		if (budget &&
-		    ((j / WB_STRIDE) == 0) && (j > 0) &&
-		    !test_bit(__I40E_VSI_DOWN, vsi->state) &&
-		    (I40E_DESC_UNUSED(tx_ring) != tx_ring->count))
-			tx_ring->arm_wb = true;
-	}
+	i40e_update_tx_stats(tx_ring, total_packets, total_bytes);
+	i40e_arm_wb(tx_ring, vsi, budget);
 
 	if (ring_is_xdp(tx_ring))
 		return !!budget;
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx_common.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx_common.h
@@ -28,4 +28,63 @@ void i40e_release_rx_desc(struct i40e_ri
 #define I40E_XDP_TX		BIT(1)
 #define I40E_XDP_REDIR		BIT(2)
 
+/**
+ * build_ctob - Builds the Tx descriptor (cmd, offset and type) qword
+ **/
+static inline __le64 build_ctob(u32 td_cmd, u32 td_offset, unsigned int size,
+				u32 td_tag)
+{
+	return cpu_to_le64(I40E_TX_DESC_DTYPE_DATA |
+			   ((u64)td_cmd  << I40E_TXD_QW1_CMD_SHIFT) |
+			   ((u64)td_offset << I40E_TXD_QW1_OFFSET_SHIFT) |
+			   ((u64)size  << I40E_TXD_QW1_TX_BUF_SZ_SHIFT) |
+			   ((u64)td_tag  << I40E_TXD_QW1_L2TAG1_SHIFT));
+}
+
+/**
+ * i40e_update_tx_stats - Update the egress statistics for the Tx ring
+ * @tx_ring: Tx ring to update
+ * @total_packet: total packets sent
+ * @total_bytes: total bytes sent
+ **/
+static inline void i40e_update_tx_stats(struct i40e_ring *tx_ring,
+					unsigned int total_packets,
+					unsigned int total_bytes)
+{
+	u64_stats_update_begin(&tx_ring->syncp);
+	tx_ring->stats.bytes += total_bytes;
+	tx_ring->stats.packets += total_packets;
+	u64_stats_update_end(&tx_ring->syncp);
+	tx_ring->q_vector->tx.total_bytes += total_bytes;
+	tx_ring->q_vector->tx.total_packets += total_packets;
+}
+
+#define WB_STRIDE 4
+
+/**
+ * i40e_arm_wb - (Possibly) arms Tx write-back
+ * @tx_ring: Tx ring to update
+ * @vsi: the VSI
+ * @budget: the NAPI budget left
+ **/
+static inline void i40e_arm_wb(struct i40e_ring *tx_ring,
+			       struct i40e_vsi *vsi,
+			       int budget)
+{
+	if (tx_ring->flags & I40E_TXR_FLAGS_WB_ON_ITR) {
+		/* check to see if there are < 4 descriptors
+		 * waiting to be written back, then kick the hardware to force
+		 * them to be written back in case we stay in NAPI.
+		 * In this mode on X722 we do not enable Interrupt.
+		 */
+		unsigned int j = i40e_get_tx_pending(tx_ring, false);
+
+		if (budget &&
+		    ((j / WB_STRIDE) == 0) && j > 0 &&
+		    !test_bit(__I40E_VSI_DOWN, vsi->state) &&
+		    (I40E_DESC_UNUSED(tx_ring) != tx_ring->count))
+			tx_ring->arm_wb = true;
+	}
+}
+
 #endif /* I40E_TXRX_COMMON_ */