[PATCH v4 11/20] net/txgbe: fix traffic class priority configuration

[Zaiyu Wang <zaiyuwang@trustnetic.com>]

After applying the following testpmd command, 802.1Q packets with specific
priorities were not properly directed to the corresponding traffic classes:
    port config 0 dcb vt off 4 pfc off

The old driver had two issues:
1. The hardware uses a 4-bit mapping register per traffic class for
   priority-to-TC mapping, but the driver incorrectly configured it
   as 3 bits.
2. The DCB TX configuration mistakenly wrote to the RX register.

Fix both issues, ensuring that tc-prio mapping works as expected.
Additionally, remove the stale and inconsistent TXGBE_DCBUP2TC_DEC macro as
it has no callers.

Fixes: 8bdc7882f376 ("net/txgbe: support DCB")
Cc: stable@dpdk.org

Signed-off-by: Zaiyu Wang <zaiyuwang@trustnetic.com>
---
 drivers/net/txgbe/base/txgbe_dcb_hw.c | 2 +-
 drivers/net/txgbe/base/txgbe_regs.h   | 6 ++----
 drivers/net/txgbe/txgbe_rxtx.c        | 7 ++-----
 3 files changed, 5 insertions(+), 10 deletions(-)

diff --git a/drivers/net/txgbe/base/txgbe_dcb_hw.c b/drivers/net/txgbe/base/txgbe_dcb_hw.c
index 75c91a6b6a..79e1da447b 100644
--- a/drivers/net/txgbe/base/txgbe_dcb_hw.c
+++ b/drivers/net/txgbe/base/txgbe_dcb_hw.c
@@ -154,7 +154,7 @@ s32 txgbe_dcb_config_tx_data_arbiter_raptor(struct txgbe_hw *hw, u16 *refill,
 	for (i = 0; i < TXGBE_DCB_UP_MAX; i++)
 		reg |= TXGBE_DCBUP2TC_MAP(i, map[i]);
 
-	wr32(hw, TXGBE_PBRXUP2TC, reg);
+	wr32(hw, TXGBE_PBTXUP2TC, reg);
 
 	/* Configure traffic class credits and priority */
 	for (i = 0; i < TXGBE_DCB_TC_MAX; i++) {
diff --git a/drivers/net/txgbe/base/txgbe_regs.h b/drivers/net/txgbe/base/txgbe_regs.h
index de382601c9..25aaf8ea68 100644
--- a/drivers/net/txgbe/base/txgbe_regs.h
+++ b/drivers/net/txgbe/base/txgbe_regs.h
@@ -503,10 +503,8 @@
 #define TXGBE_PBRXCTL                   0x019000
 #define   TXGBE_PBRXCTL_ST              MS(0, 0x1)
 #define   TXGBE_PBRXCTL_ENA             MS(31, 0x1)
-#define TXGBE_PBRXUP2TC                 0x019008
 #define TXGBE_PBTXUP2TC                 0x01C800
-#define   TXGBE_DCBUP2TC_MAP(tc, v)     LS(v, 3 * (tc), 0x7)
-#define   TXGBE_DCBUP2TC_DEC(tc, r)     RS(r, 3 * (tc), 0x7)
+#define   TXGBE_DCBUP2TC_MAP(tc, v)     LS(v, 4 * (tc), 0x7)
 #define TXGBE_PBRXSIZE(tc)              (0x019020 + (tc) * 4)
 #define   TXGBE_PBRXSIZE_KB(v)          LS(v, 10, 0x3FF)
 
@@ -1703,7 +1701,7 @@ enum txgbe_5tuple_protocol {
 #define TXGBE_RDM_PF_HIDE(_i)   (0x12090 + ((_i) * 4))
 
 #define TXGBE_RPUP2TC                   0x019008
-#define   TXGBE_RPUP2TC_UP_SHIFT        3
+#define   TXGBE_RPUP2TC_UP_SHIFT        4
 #define   TXGBE_RPUP2TC_UP_MASK         0x7
 
 #define TXGBE_RDM_DCACHE_CTL             0x0120A8
diff --git a/drivers/net/txgbe/txgbe_rxtx.c b/drivers/net/txgbe/txgbe_rxtx.c
index be279dc4ec..851cd122d8 100644
--- a/drivers/net/txgbe/txgbe_rxtx.c
+++ b/drivers/net/txgbe/txgbe_rxtx.c
@@ -3385,11 +3385,8 @@ txgbe_vmdq_dcb_configure(struct rte_eth_dev *dev)
 
 	queue_mapping = 0;
 	for (i = 0; i < RTE_ETH_DCB_NUM_USER_PRIORITIES; i++)
-		/*
-		 * mapping is done with 3 bits per priority,
-		 * so shift by i*3 each time
-		 */
-		queue_mapping |= ((cfg->dcb_tc[i] & 0x07) << (i * 3));
+		queue_mapping |= ((cfg->dcb_tc[i] & TXGBE_RPUP2TC_UP_MASK) <<
+				  (i * TXGBE_RPUP2TC_UP_SHIFT));
 
 	wr32(hw, TXGBE_RPUP2TC, queue_mapping);
 
-- 
2.21.0.windows.1