diff options
Diffstat (limited to 'drivers/net/ethernet/mediatek/mtk_ppe.c')
| -rw-r--r-- | drivers/net/ethernet/mediatek/mtk_ppe.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/drivers/net/ethernet/mediatek/mtk_ppe.c b/drivers/net/ethernet/mediatek/mtk_ppe.c index 75f7728fc796..18279e2a7022 100644 --- a/drivers/net/ethernet/mediatek/mtk_ppe.c +++ b/drivers/net/ethernet/mediatek/mtk_ppe.c @@ -973,6 +973,36 @@ static void mtk_ppe_init_foe_table(struct mtk_ppe *ppe) } } +void mtk_ppe_update_mtu(struct mtk_ppe *ppe, int mtu) +{ + int base; + u32 val; + + if (!ppe) + return; + + /* The PPE checks output frame size against per-tag-layer MTU limits, + * treating PPPoE and DSA tags just like 802.1Q VLAN tags. The Linux + * device MTU already accounts for PPPoE (PPPOE_SES_HLEN) and DSA tag + * overhead, but 802.1Q VLAN tags are handled transparently without + * being reflected by the lower device MTU being increased by 4. + * Use the maximum MTU across all GMAC interfaces so that PPE output + * frame limits are sufficiently high regardless of which port a flow + * egresses through. + */ + base = ETH_HLEN + mtu; + + val = FIELD_PREP(MTK_PPE_VLAN_MTU0_NONE, base) | + FIELD_PREP(MTK_PPE_VLAN_MTU0_1TAG, base + VLAN_HLEN); + ppe_w32(ppe, MTK_PPE_VLAN_MTU0, val); + + val = FIELD_PREP(MTK_PPE_VLAN_MTU1_2TAG, + base + 2 * VLAN_HLEN) | + FIELD_PREP(MTK_PPE_VLAN_MTU1_3TAG, + base + 3 * VLAN_HLEN); + ppe_w32(ppe, MTK_PPE_VLAN_MTU1, val); +} + void mtk_ppe_start(struct mtk_ppe *ppe) { u32 val; |