1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (c) 2019 Pengutronix, Oleksij Rempel <kernel@pengutronix.de> 4 */ 5 6 7 #include <linux/bitfield.h> 8 #include <linux/etherdevice.h> 9 10 #include "dsa_priv.h" 11 12 #define AR9331_HDR_LEN 2 13 #define AR9331_HDR_VERSION 1 14 15 #define AR9331_HDR_VERSION_MASK GENMASK(15, 14) 16 #define AR9331_HDR_PRIORITY_MASK GENMASK(13, 12) 17 #define AR9331_HDR_TYPE_MASK GENMASK(10, 8) 18 #define AR9331_HDR_BROADCAST BIT(7) 19 #define AR9331_HDR_FROM_CPU BIT(6) 20 /* AR9331_HDR_RESERVED - not used or may be version field. 21 * According to the AR8216 doc it should 0b10. On AR9331 it is 0b11 on RX path 22 * and should be set to 0b11 to make it work. 23 */ 24 #define AR9331_HDR_RESERVED_MASK GENMASK(5, 4) 25 #define AR9331_HDR_PORT_NUM_MASK GENMASK(3, 0) 26 27 static struct sk_buff *ar9331_tag_xmit(struct sk_buff *skb, 28 struct net_device *dev) 29 { 30 struct dsa_port *dp = dsa_slave_to_port(dev); 31 __le16 *phdr; 32 u16 hdr; 33 34 if (skb_cow_head(skb, AR9331_HDR_LEN) < 0) 35 return NULL; 36 37 phdr = skb_push(skb, AR9331_HDR_LEN); 38 39 hdr = FIELD_PREP(AR9331_HDR_VERSION_MASK, AR9331_HDR_VERSION); 40 hdr |= AR9331_HDR_FROM_CPU | dp->index; 41 /* 0b10 for AR8216 and 0b11 for AR9331 */ 42 hdr |= AR9331_HDR_RESERVED_MASK; 43 44 phdr[0] = cpu_to_le16(hdr); 45 46 return skb; 47 } 48 49 static struct sk_buff *ar9331_tag_rcv(struct sk_buff *skb, 50 struct net_device *ndev, 51 struct packet_type *pt) 52 { 53 u8 ver, port; 54 u16 hdr; 55 56 if (unlikely(!pskb_may_pull(skb, AR9331_HDR_LEN))) 57 return NULL; 58 59 hdr = le16_to_cpu(*(__le16 *)skb_mac_header(skb)); 60 61 ver = FIELD_GET(AR9331_HDR_VERSION_MASK, hdr); 62 if (unlikely(ver != AR9331_HDR_VERSION)) { 63 netdev_warn_once(ndev, "%s:%i wrong header version 0x%2x\n", 64 __func__, __LINE__, hdr); 65 return NULL; 66 } 67 68 if (unlikely(hdr & AR9331_HDR_FROM_CPU)) { 69 netdev_warn_once(ndev, "%s:%i packet should not be from cpu 0x%2x\n", 70 __func__, __LINE__, hdr); 71 return NULL; 72 } 73 74 skb_pull_rcsum(skb, AR9331_HDR_LEN); 75 76 /* Get source port information */ 77 port = FIELD_GET(AR9331_HDR_PORT_NUM_MASK, hdr); 78 79 skb->dev = dsa_master_find_slave(ndev, 0, port); 80 if (!skb->dev) 81 return NULL; 82 83 return skb; 84 } 85 86 static const struct dsa_device_ops ar9331_netdev_ops = { 87 .name = "ar9331", 88 .proto = DSA_TAG_PROTO_AR9331, 89 .xmit = ar9331_tag_xmit, 90 .rcv = ar9331_tag_rcv, 91 .overhead = AR9331_HDR_LEN, 92 }; 93 94 MODULE_LICENSE("GPL v2"); 95 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_AR9331); 96 module_dsa_tag_driver(ar9331_netdev_ops); 97