[PATCH net-next,v2 21/24] net: ethernet: mtk_eth_soc: fix parsing packets in GDM

[Pablo Neira Ayuso]

From: Felix Fietkau <n...@nbd.name>

When using DSA, set the special tag in GDM ingress control to allow the MAC
to parse packets properly earlier. This affects rx DMA source port reporting.

Signed-off-by: Felix Fietkau <n...@nbd.name>
Signed-off-by: Pablo Neira Ayuso <pa...@netfilter.org>
---
v2: formely patch #23, now patch #21.

 drivers/net/ethernet/mediatek/mtk_eth_soc.c | 15 +++++++++------
 drivers/net/ethernet/mediatek/mtk_eth_soc.h |  2 ++
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c 
b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 01d3ee4b5829..cf65fbdf60e0 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -19,6 +19,7 @@
 #include <linux/interrupt.h>
 #include <linux/pinctrl/devinfo.h>
 #include <linux/phylink.h>
+#include <net/dsa.h>
 
 #include "mtk_eth_soc.h"
 
@@ -1264,13 +1265,12 @@ static int mtk_poll_rx(struct napi_struct *napi, int 
budget,
                        break;
 
                /* find out which mac the packet come from. values start at 1 */
-               if (MTK_HAS_CAPS(eth->soc->caps, MTK_SOC_MT7628)) {
+               if (MTK_HAS_CAPS(eth->soc->caps, MTK_SOC_MT7628) ||
+                   (trxd.rxd4 & RX_DMA_SPECIAL_TAG))
                        mac = 0;
-               } else {
-                       mac = (trxd.rxd4 >> RX_DMA_FPORT_SHIFT) &
-                               RX_DMA_FPORT_MASK;
-                       mac--;
-               }
+               else
+                       mac = ((trxd.rxd4 >> RX_DMA_FPORT_SHIFT) &
+                              RX_DMA_FPORT_MASK) - 1;
 
                if (unlikely(mac < 0 || mac >= MTK_MAC_COUNT ||
                             !eth->netdev[mac]))
@@ -2233,6 +2233,9 @@ static void mtk_gdm_config(struct mtk_eth *eth, u32 
config)
 
                val |= config;
 
+               if (!i && eth->netdev[0] && netdev_uses_dsa(eth->netdev[0]))
+                       val |= MTK_GDMA_SPECIAL_TAG;
+
                mtk_w32(eth, val, MTK_GDMA_FWD_CFG(i));
        }
        /* Reset and enable PSE */
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h 
b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index fd3cec8f06ba..2d065d47dbfd 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -82,6 +82,7 @@
 
 /* GDM Exgress Control Register */
 #define MTK_GDMA_FWD_CFG(x)    (0x500 + (x * 0x1000))
+#define MTK_GDMA_SPECIAL_TAG   BIT(24)
 #define MTK_GDMA_ICS_EN                BIT(22)
 #define MTK_GDMA_TCS_EN                BIT(21)
 #define MTK_GDMA_UCS_EN                BIT(20)
@@ -305,6 +306,7 @@
 #define RX_DMA_L4_VALID_PDMA   BIT(30)         /* when PDMA is used */
 #define RX_DMA_FPORT_SHIFT     19
 #define RX_DMA_FPORT_MASK      0x7
+#define RX_DMA_SPECIAL_TAG     BIT(22)
 
 /* PHY Indirect Access Control registers */
 #define MTK_PHY_IAC            0x10004
-- 
2.20.1