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 */
ipc_wwan_link_open(struct net_device * netdev)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 */
ipc_wwan_link_stop(struct net_device * netdev)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 */
ipc_wwan_link_transmit(struct sk_buff * skb,struct net_device * netdev)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 */
ipc_wwan_setup(struct net_device * iosm_dev)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 */
ipc_wwan_newlink(void * ctxt,struct net_device * dev,u32 if_id,struct netlink_ext_ack * extack)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
ipc_wwan_dellink(void * ctxt,struct net_device * dev,struct list_head * head)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
ipc_wwan_receive(struct iosm_wwan * ipc_wwan,struct sk_buff * skb_arg,bool dss,int if_id)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
ipc_wwan_tx_flowctrl(struct iosm_wwan * ipc_wwan,int if_id,bool on)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
ipc_wwan_init(struct iosm_imem * ipc_imem,struct device * dev)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
ipc_wwan_deinit(struct iosm_wwan * ipc_wwan)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