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 "tag.h" 11 12 #define AR9331_NAME "ar9331" 13 14 #define AR9331_HDR_LEN 2 15 #define AR9331_HDR_VERSION 1 16 17 #define AR9331_HDR_VERSION_MASK GENMASK(15, 14) 18 #define AR9331_HDR_PRIORITY_MASK GENMASK(13, 12) 19 #define AR9331_HDR_TYPE_MASK GENMASK(10, 8) 20 #define AR9331_HDR_BROADCAST BIT(7) 21 #define AR9331_HDR_FROM_CPU BIT(6) 22 /* AR9331_HDR_RESERVED - not used or may be version field. 23 * According to the AR8216 doc it should 0b10. On AR9331 it is 0b11 on RX path 24 * and should be set to 0b11 to make it work. 25 */ 26 #define AR9331_HDR_RESERVED_MASK GENMASK(5, 4) 27 #define AR9331_HDR_PORT_NUM_MASK GENMASK(3, 0) 28 29 static struct sk_buff *ar9331_tag_xmit(struct sk_buff *skb, 30 struct net_device *dev) 31 { 32 struct dsa_port *dp = dsa_slave_to_port(dev); 33 __le16 *phdr; 34 u16 hdr; 35 36 phdr = skb_push(skb, AR9331_HDR_LEN); 37 38 hdr = FIELD_PREP(AR9331_HDR_VERSION_MASK, AR9331_HDR_VERSION); 39 hdr |= AR9331_HDR_FROM_CPU | dp->index; 40 /* 0b10 for AR8216 and 0b11 for AR9331 */ 41 hdr |= AR9331_HDR_RESERVED_MASK; 42 43 phdr[0] = cpu_to_le16(hdr); 44 45 return skb; 46 } 47 48 static struct sk_buff *ar9331_tag_rcv(struct sk_buff *skb, 49 struct net_device *ndev) 50 { 51 u8 ver, port; 52 u16 hdr; 53 54 if (unlikely(!pskb_may_pull(skb, AR9331_HDR_LEN))) 55 return NULL; 56 57 hdr = le16_to_cpu(*(__le16 *)skb_mac_header(skb)); 58 59 ver = FIELD_GET(AR9331_HDR_VERSION_MASK, hdr); 60 if (unlikely(ver != AR9331_HDR_VERSION)) { 61 netdev_warn_once(ndev, "%s:%i wrong header version 0x%2x\n", 62 __func__, __LINE__, hdr); 63 return NULL; 64 } 65 66 if (unlikely(hdr & AR9331_HDR_FROM_CPU)) { 67 netdev_warn_once(ndev, "%s:%i packet should not be from cpu 0x%2x\n", 68 __func__, __LINE__, hdr); 69 return NULL; 70 } 71 72 skb_pull_rcsum(skb, AR9331_HDR_LEN); 73 74 /* Get source port information */ 75 port = FIELD_GET(AR9331_HDR_PORT_NUM_MASK, hdr); 76 77 skb->dev = dsa_master_find_slave(ndev, 0, port); 78 if (!skb->dev) 79 return NULL; 80 81 return skb; 82 } 83 84 static const struct dsa_device_ops ar9331_netdev_ops = { 85 .name = AR9331_NAME, 86 .proto = DSA_TAG_PROTO_AR9331, 87 .xmit = ar9331_tag_xmit, 88 .rcv = ar9331_tag_rcv, 89 .needed_headroom = AR9331_HDR_LEN, 90 }; 91 92 MODULE_LICENSE("GPL v2"); 93 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_AR9331, AR9331_NAME); 94 module_dsa_tag_driver(ar9331_netdev_ops); 95