1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2020-21 Intel Corporation. 4 */ 5 6 #include <linux/etherdevice.h> 7 #include <linux/if_arp.h> 8 #include <linux/if_link.h> 9 #include <linux/rtnetlink.h> 10 #include <linux/wwan.h> 11 #include <net/pkt_sched.h> 12 13 #include "iosm_ipc_chnl_cfg.h" 14 #include "iosm_ipc_imem_ops.h" 15 #include "iosm_ipc_wwan.h" 16 17 #define IOSM_IP_TYPE_MASK 0xF0 18 #define IOSM_IP_TYPE_IPV4 0x40 19 #define IOSM_IP_TYPE_IPV6 0x60 20 21 /** 22 * struct iosm_netdev_priv - netdev WWAN driver specific private data 23 * @ipc_wwan: Pointer to iosm_wwan struct 24 * @netdev: Pointer to network interface device structure 25 * @if_id: Interface id for device. 26 * @ch_id: IPC channel number for which interface device is created. 27 */ 28 struct iosm_netdev_priv { 29 struct iosm_wwan *ipc_wwan; 30 struct net_device *netdev; 31 int if_id; 32 int ch_id; 33 }; 34 35 /** 36 * struct iosm_wwan - This structure contains information about WWAN root device 37 * and interface to the IPC layer. 38 * @ipc_imem: Pointer to imem data-struct 39 * @sub_netlist: List of active netdevs 40 * @dev: Pointer device structure 41 */ 42 struct iosm_wwan { 43 struct iosm_imem *ipc_imem; 44 struct iosm_netdev_priv __rcu *sub_netlist[IP_MUX_SESSION_END + 1]; 45 struct device *dev; 46 }; 47 48 /* Bring-up the wwan net link */ 49 static int ipc_wwan_link_open(struct net_device *netdev) 50 { 51 struct iosm_netdev_priv *priv = wwan_netdev_drvpriv(netdev); 52 struct iosm_wwan *ipc_wwan = priv->ipc_wwan; 53 int if_id = priv->if_id; 54 55 if (if_id < IP_MUX_SESSION_START || 56 if_id >= ARRAY_SIZE(ipc_wwan->sub_netlist)) 57 return -EINVAL; 58 59 /* get channel id */ 60 priv->ch_id = ipc_imem_sys_wwan_open(ipc_wwan->ipc_imem, if_id); 61 62 if (priv->ch_id < 0) { 63 dev_err(ipc_wwan->dev, 64 "cannot connect wwan0 & id %d to the IPC mem layer", 65 if_id); 66 return -ENODEV; 67 } 68 69 /* enable tx path, DL data may follow */ 70 netif_start_queue(netdev); 71 72 dev_dbg(ipc_wwan->dev, "Channel id %d allocated to if_id %d", 73 priv->ch_id, priv->if_id); 74 75 return 0; 76 } 77 78 /* Bring-down the wwan net link */ 79 static int ipc_wwan_link_stop(struct net_device *netdev) 80 { 81 struct iosm_netdev_priv *priv = wwan_netdev_drvpriv(netdev); 82 83 netif_stop_queue(netdev); 84 85 ipc_imem_sys_wwan_close(priv->ipc_wwan->ipc_imem, priv->if_id, 86 priv->ch_id); 87 priv->ch_id = -1; 88 89 return 0; 90 } 91 92 /* Transmit a packet */ 93 static netdev_tx_t ipc_wwan_link_transmit(struct sk_buff *skb, 94 struct net_device *netdev) 95 { 96 struct iosm_netdev_priv *priv = wwan_netdev_drvpriv(netdev); 97 struct iosm_wwan *ipc_wwan = priv->ipc_wwan; 98 unsigned int len = skb->len; 99 int if_id = priv->if_id; 100 int ret; 101 102 /* Interface IDs from 1 to 8 are for IP data 103 * & from 257 to 261 are for non-IP data 104 */ 105 if (if_id < IP_MUX_SESSION_START || 106 if_id >= ARRAY_SIZE(ipc_wwan->sub_netlist)) 107 return -EINVAL; 108 109 /* Send the SKB to device for transmission */ 110 ret = ipc_imem_sys_wwan_transmit(ipc_wwan->ipc_imem, 111 if_id, priv->ch_id, skb); 112 113 /* Return code of zero is success */ 114 if (ret == 0) { 115 netdev->stats.tx_packets++; 116 netdev->stats.tx_bytes += len; 117 ret = NETDEV_TX_OK; 118 } else if (ret == -EBUSY) { 119 ret = NETDEV_TX_BUSY; 120 dev_err(ipc_wwan->dev, "unable to push packets"); 121 } else { 122 goto exit; 123 } 124 125 return ret; 126 127 exit: 128 /* Log any skb drop */ 129 if (if_id) 130 dev_dbg(ipc_wwan->dev, "skb dropped. IF_ID: %d, ret: %d", if_id, 131 ret); 132 133 dev_kfree_skb_any(skb); 134 netdev->stats.tx_dropped++; 135 return NETDEV_TX_OK; 136 } 137 138 /* Ops structure for wwan net link */ 139 static const struct net_device_ops ipc_inm_ops = { 140 .ndo_open = ipc_wwan_link_open, 141 .ndo_stop = ipc_wwan_link_stop, 142 .ndo_start_xmit = ipc_wwan_link_transmit, 143 }; 144 145 /* Setup function for creating new net link */ 146 static void ipc_wwan_setup(struct net_device *iosm_dev) 147 { 148 iosm_dev->header_ops = NULL; 149 iosm_dev->hard_header_len = 0; 150 iosm_dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN; 151 152 iosm_dev->type = ARPHRD_NONE; 153 iosm_dev->mtu = ETH_DATA_LEN; 154 iosm_dev->min_mtu = ETH_MIN_MTU; 155 iosm_dev->max_mtu = ETH_MAX_MTU; 156 157 iosm_dev->flags = IFF_POINTOPOINT | IFF_NOARP; 158 iosm_dev->needs_free_netdev = true; 159 160 iosm_dev->netdev_ops = &ipc_inm_ops; 161 } 162 163 /* Create new wwan net link */ 164 static int ipc_wwan_newlink(void *ctxt, struct net_device *dev, 165 u32 if_id, struct netlink_ext_ack *extack) 166 { 167 struct iosm_wwan *ipc_wwan = ctxt; 168 struct iosm_netdev_priv *priv; 169 int err; 170 171 if (if_id < IP_MUX_SESSION_START || 172 if_id >= ARRAY_SIZE(ipc_wwan->sub_netlist)) 173 return -EINVAL; 174 175 priv = wwan_netdev_drvpriv(dev); 176 priv->if_id = if_id; 177 priv->netdev = dev; 178 priv->ipc_wwan = ipc_wwan; 179 180 if (rcu_access_pointer(ipc_wwan->sub_netlist[if_id])) 181 return -EBUSY; 182 183 err = register_netdevice(dev); 184 if (err) 185 return err; 186 187 rcu_assign_pointer(ipc_wwan->sub_netlist[if_id], priv); 188 netif_device_attach(dev); 189 190 return 0; 191 } 192 193 static void ipc_wwan_dellink(void *ctxt, struct net_device *dev, 194 struct list_head *head) 195 { 196 struct iosm_netdev_priv *priv = wwan_netdev_drvpriv(dev); 197 struct iosm_wwan *ipc_wwan = ctxt; 198 int if_id = priv->if_id; 199 200 if (WARN_ON(if_id < IP_MUX_SESSION_START || 201 if_id >= ARRAY_SIZE(ipc_wwan->sub_netlist))) 202 return; 203 204 if (WARN_ON(rcu_access_pointer(ipc_wwan->sub_netlist[if_id]) != priv)) 205 return; 206 207 RCU_INIT_POINTER(ipc_wwan->sub_netlist[if_id], NULL); 208 /* unregistering includes synchronize_net() */ 209 unregister_netdevice_queue(dev, head); 210 } 211 212 static const struct wwan_ops iosm_wwan_ops = { 213 .priv_size = sizeof(struct iosm_netdev_priv), 214 .setup = ipc_wwan_setup, 215 .newlink = ipc_wwan_newlink, 216 .dellink = ipc_wwan_dellink, 217 }; 218 219 int ipc_wwan_receive(struct iosm_wwan *ipc_wwan, struct sk_buff *skb_arg, 220 bool dss, int if_id) 221 { 222 struct sk_buff *skb = skb_arg; 223 struct net_device_stats *stats; 224 struct iosm_netdev_priv *priv; 225 int ret; 226 227 if ((skb->data[0] & IOSM_IP_TYPE_MASK) == IOSM_IP_TYPE_IPV4) 228 skb->protocol = htons(ETH_P_IP); 229 else if ((skb->data[0] & IOSM_IP_TYPE_MASK) == 230 IOSM_IP_TYPE_IPV6) 231 skb->protocol = htons(ETH_P_IPV6); 232 233 skb->pkt_type = PACKET_HOST; 234 235 if (if_id < IP_MUX_SESSION_START || 236 if_id > IP_MUX_SESSION_END) { 237 ret = -EINVAL; 238 goto free; 239 } 240 241 rcu_read_lock(); 242 priv = rcu_dereference(ipc_wwan->sub_netlist[if_id]); 243 if (!priv) { 244 ret = -EINVAL; 245 goto unlock; 246 } 247 skb->dev = priv->netdev; 248 stats = &priv->netdev->stats; 249 stats->rx_packets++; 250 stats->rx_bytes += skb->len; 251 252 ret = netif_rx(skb); 253 skb = NULL; 254 unlock: 255 rcu_read_unlock(); 256 free: 257 dev_kfree_skb(skb); 258 return ret; 259 } 260 261 void ipc_wwan_tx_flowctrl(struct iosm_wwan *ipc_wwan, int if_id, bool on) 262 { 263 struct net_device *netdev; 264 struct iosm_netdev_priv *priv; 265 bool is_tx_blk; 266 267 rcu_read_lock(); 268 priv = rcu_dereference(ipc_wwan->sub_netlist[if_id]); 269 if (!priv) { 270 rcu_read_unlock(); 271 return; 272 } 273 274 netdev = priv->netdev; 275 276 is_tx_blk = netif_queue_stopped(netdev); 277 278 if (on) 279 dev_dbg(ipc_wwan->dev, "session id[%d]: flowctrl enable", 280 if_id); 281 282 if (on && !is_tx_blk) 283 netif_stop_queue(netdev); 284 else if (!on && is_tx_blk) 285 netif_wake_queue(netdev); 286 rcu_read_unlock(); 287 } 288 289 struct iosm_wwan *ipc_wwan_init(struct iosm_imem *ipc_imem, struct device *dev) 290 { 291 struct iosm_wwan *ipc_wwan; 292 293 ipc_wwan = kzalloc(sizeof(*ipc_wwan), GFP_KERNEL); 294 if (!ipc_wwan) 295 return NULL; 296 297 ipc_wwan->dev = dev; 298 ipc_wwan->ipc_imem = ipc_imem; 299 300 /* WWAN core will create a netdev for the default IP MUX channel */ 301 if (wwan_register_ops(ipc_wwan->dev, &iosm_wwan_ops, ipc_wwan, 302 IP_MUX_SESSION_DEFAULT)) { 303 kfree(ipc_wwan); 304 return NULL; 305 } 306 307 return ipc_wwan; 308 } 309 310 void ipc_wwan_deinit(struct iosm_wwan *ipc_wwan) 311 { 312 /* This call will remove all child netdev(s) */ 313 wwan_unregister_ops(ipc_wwan->dev); 314 315 kfree(ipc_wwan); 316 } 317