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 #define IOSM_IF_ID_PAYLOAD 2
22
23 /**
24 * struct iosm_netdev_priv - netdev WWAN driver specific private data
25 * @ipc_wwan: Pointer to iosm_wwan struct
26 * @netdev: Pointer to network interface device structure
27 * @if_id: Interface id for device.
28 * @ch_id: IPC channel number for which interface device is created.
29 */
30 struct iosm_netdev_priv {
31 struct iosm_wwan *ipc_wwan;
32 struct net_device *netdev;
33 int if_id;
34 int ch_id;
35 };
36
37 /**
38 * struct iosm_wwan - This structure contains information about WWAN root device
39 * and interface to the IPC layer.
40 * @ipc_imem: Pointer to imem data-struct
41 * @sub_netlist: List of active netdevs
42 * @dev: Pointer device structure
43 * @if_mutex: Mutex used for add and remove interface id
44 */
45 struct iosm_wwan {
46 struct iosm_imem *ipc_imem;
47 struct iosm_netdev_priv __rcu *sub_netlist[IP_MUX_SESSION_END + 1];
48 struct device *dev;
49 struct mutex if_mutex; /* Mutex used for add and remove interface id */
50 };
51
52 /* Bring-up the wwan net link */
ipc_wwan_link_open(struct net_device * netdev)53 static int ipc_wwan_link_open(struct net_device *netdev)
54 {
55 struct iosm_netdev_priv *priv = wwan_netdev_drvpriv(netdev);
56 struct iosm_wwan *ipc_wwan = priv->ipc_wwan;
57 int if_id = priv->if_id;
58 int ret;
59
60 if (if_id < IP_MUX_SESSION_START ||
61 if_id >= ARRAY_SIZE(ipc_wwan->sub_netlist))
62 return -EINVAL;
63
64 mutex_lock(&ipc_wwan->if_mutex);
65
66 /* get channel id */
67 priv->ch_id = ipc_imem_sys_wwan_open(ipc_wwan->ipc_imem, if_id);
68
69 if (priv->ch_id < 0) {
70 dev_err(ipc_wwan->dev,
71 "cannot connect wwan0 & id %d to the IPC mem layer",
72 if_id);
73 ret = -ENODEV;
74 goto out;
75 }
76
77 /* enable tx path, DL data may follow */
78 netif_start_queue(netdev);
79
80 dev_dbg(ipc_wwan->dev, "Channel id %d allocated to if_id %d",
81 priv->ch_id, priv->if_id);
82
83 ret = 0;
84 out:
85 mutex_unlock(&ipc_wwan->if_mutex);
86 return ret;
87 }
88
89 /* Bring-down the wwan net link */
ipc_wwan_link_stop(struct net_device * netdev)90 static int ipc_wwan_link_stop(struct net_device *netdev)
91 {
92 struct iosm_netdev_priv *priv = wwan_netdev_drvpriv(netdev);
93
94 netif_stop_queue(netdev);
95
96 mutex_lock(&priv->ipc_wwan->if_mutex);
97 ipc_imem_sys_wwan_close(priv->ipc_wwan->ipc_imem, priv->if_id,
98 priv->ch_id);
99 priv->ch_id = -1;
100 mutex_unlock(&priv->ipc_wwan->if_mutex);
101
102 return 0;
103 }
104
105 /* Transmit a packet */
ipc_wwan_link_transmit(struct sk_buff * skb,struct net_device * netdev)106 static int ipc_wwan_link_transmit(struct sk_buff *skb,
107 struct net_device *netdev)
108 {
109 struct iosm_netdev_priv *priv = wwan_netdev_drvpriv(netdev);
110 struct iosm_wwan *ipc_wwan = priv->ipc_wwan;
111 unsigned int len = skb->len;
112 int if_id = priv->if_id;
113 int ret;
114
115 /* Interface IDs from 1 to 8 are for IP data
116 * & from 257 to 261 are for non-IP data
117 */
118 if (if_id < IP_MUX_SESSION_START ||
119 if_id >= ARRAY_SIZE(ipc_wwan->sub_netlist))
120 return -EINVAL;
121
122 /* Send the SKB to device for transmission */
123 ret = ipc_imem_sys_wwan_transmit(ipc_wwan->ipc_imem,
124 if_id, priv->ch_id, skb);
125
126 /* Return code of zero is success */
127 if (ret == 0) {
128 netdev->stats.tx_packets++;
129 netdev->stats.tx_bytes += len;
130 ret = NETDEV_TX_OK;
131 } else if (ret == -EBUSY) {
132 ret = NETDEV_TX_BUSY;
133 dev_err(ipc_wwan->dev, "unable to push packets");
134 } else {
135 goto exit;
136 }
137
138 return ret;
139
140 exit:
141 /* Log any skb drop */
142 if (if_id)
143 dev_dbg(ipc_wwan->dev, "skb dropped. IF_ID: %d, ret: %d", if_id,
144 ret);
145
146 dev_kfree_skb_any(skb);
147 netdev->stats.tx_dropped++;
148 return NETDEV_TX_OK;
149 }
150
151 /* Ops structure for wwan net link */
152 static const struct net_device_ops ipc_inm_ops = {
153 .ndo_open = ipc_wwan_link_open,
154 .ndo_stop = ipc_wwan_link_stop,
155 .ndo_start_xmit = ipc_wwan_link_transmit,
156 };
157
158 /* Setup function for creating new net link */
ipc_wwan_setup(struct net_device * iosm_dev)159 static void ipc_wwan_setup(struct net_device *iosm_dev)
160 {
161 iosm_dev->header_ops = NULL;
162 iosm_dev->hard_header_len = 0;
163 iosm_dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
164
165 iosm_dev->type = ARPHRD_NONE;
166 iosm_dev->mtu = ETH_DATA_LEN;
167 iosm_dev->min_mtu = ETH_MIN_MTU;
168 iosm_dev->max_mtu = ETH_MAX_MTU;
169
170 iosm_dev->flags = IFF_POINTOPOINT | IFF_NOARP;
171
172 iosm_dev->netdev_ops = &ipc_inm_ops;
173 }
174
175 /* Create new wwan net link */
ipc_wwan_newlink(void * ctxt,struct net_device * dev,u32 if_id,struct netlink_ext_ack * extack)176 static int ipc_wwan_newlink(void *ctxt, struct net_device *dev,
177 u32 if_id, struct netlink_ext_ack *extack)
178 {
179 struct iosm_wwan *ipc_wwan = ctxt;
180 struct iosm_netdev_priv *priv;
181 int err;
182
183 if (if_id < IP_MUX_SESSION_START ||
184 if_id >= ARRAY_SIZE(ipc_wwan->sub_netlist))
185 return -EINVAL;
186
187 priv = wwan_netdev_drvpriv(dev);
188 priv->if_id = if_id;
189 priv->netdev = dev;
190 priv->ipc_wwan = ipc_wwan;
191
192 mutex_lock(&ipc_wwan->if_mutex);
193 if (rcu_access_pointer(ipc_wwan->sub_netlist[if_id])) {
194 err = -EBUSY;
195 goto out_unlock;
196 }
197
198 err = register_netdevice(dev);
199 if (err)
200 goto out_unlock;
201
202 rcu_assign_pointer(ipc_wwan->sub_netlist[if_id], priv);
203 mutex_unlock(&ipc_wwan->if_mutex);
204
205 netif_device_attach(dev);
206
207 return 0;
208
209 out_unlock:
210 mutex_unlock(&ipc_wwan->if_mutex);
211 return err;
212 }
213
ipc_wwan_dellink(void * ctxt,struct net_device * dev,struct list_head * head)214 static void ipc_wwan_dellink(void *ctxt, struct net_device *dev,
215 struct list_head *head)
216 {
217 struct iosm_netdev_priv *priv = wwan_netdev_drvpriv(dev);
218 struct iosm_wwan *ipc_wwan = ctxt;
219 int if_id = priv->if_id;
220
221 if (WARN_ON(if_id < IP_MUX_SESSION_START ||
222 if_id >= ARRAY_SIZE(ipc_wwan->sub_netlist)))
223 return;
224
225 mutex_lock(&ipc_wwan->if_mutex);
226
227 if (WARN_ON(rcu_access_pointer(ipc_wwan->sub_netlist[if_id]) != priv))
228 goto unlock;
229
230 RCU_INIT_POINTER(ipc_wwan->sub_netlist[if_id], NULL);
231 /* unregistering includes synchronize_net() */
232 unregister_netdevice_queue(dev, head);
233
234 unlock:
235 mutex_unlock(&ipc_wwan->if_mutex);
236 }
237
238 static const struct wwan_ops iosm_wwan_ops = {
239 .priv_size = sizeof(struct iosm_netdev_priv),
240 .setup = ipc_wwan_setup,
241 .newlink = ipc_wwan_newlink,
242 .dellink = ipc_wwan_dellink,
243 };
244
ipc_wwan_receive(struct iosm_wwan * ipc_wwan,struct sk_buff * skb_arg,bool dss,int if_id)245 int ipc_wwan_receive(struct iosm_wwan *ipc_wwan, struct sk_buff *skb_arg,
246 bool dss, int if_id)
247 {
248 struct sk_buff *skb = skb_arg;
249 struct net_device_stats *stats;
250 struct iosm_netdev_priv *priv;
251 int ret;
252
253 if ((skb->data[0] & IOSM_IP_TYPE_MASK) == IOSM_IP_TYPE_IPV4)
254 skb->protocol = htons(ETH_P_IP);
255 else if ((skb->data[0] & IOSM_IP_TYPE_MASK) ==
256 IOSM_IP_TYPE_IPV6)
257 skb->protocol = htons(ETH_P_IPV6);
258
259 skb->pkt_type = PACKET_HOST;
260
261 if (if_id < IP_MUX_SESSION_START ||
262 if_id > IP_MUX_SESSION_END) {
263 ret = -EINVAL;
264 goto free;
265 }
266
267 rcu_read_lock();
268 priv = rcu_dereference(ipc_wwan->sub_netlist[if_id]);
269 if (!priv) {
270 ret = -EINVAL;
271 goto unlock;
272 }
273 skb->dev = priv->netdev;
274 stats = &priv->netdev->stats;
275 stats->rx_packets++;
276 stats->rx_bytes += skb->len;
277
278 ret = netif_rx(skb);
279 skb = NULL;
280 unlock:
281 rcu_read_unlock();
282 free:
283 dev_kfree_skb(skb);
284 return ret;
285 }
286
ipc_wwan_tx_flowctrl(struct iosm_wwan * ipc_wwan,int if_id,bool on)287 void ipc_wwan_tx_flowctrl(struct iosm_wwan *ipc_wwan, int if_id, bool on)
288 {
289 struct net_device *netdev;
290 struct iosm_netdev_priv *priv;
291 bool is_tx_blk;
292
293 rcu_read_lock();
294 priv = rcu_dereference(ipc_wwan->sub_netlist[if_id]);
295 if (!priv) {
296 rcu_read_unlock();
297 return;
298 }
299
300 netdev = priv->netdev;
301
302 is_tx_blk = netif_queue_stopped(netdev);
303
304 if (on)
305 dev_dbg(ipc_wwan->dev, "session id[%d]: flowctrl enable",
306 if_id);
307
308 if (on && !is_tx_blk)
309 netif_stop_queue(netdev);
310 else if (!on && is_tx_blk)
311 netif_wake_queue(netdev);
312 rcu_read_unlock();
313 }
314
ipc_wwan_init(struct iosm_imem * ipc_imem,struct device * dev)315 struct iosm_wwan *ipc_wwan_init(struct iosm_imem *ipc_imem, struct device *dev)
316 {
317 struct iosm_wwan *ipc_wwan;
318
319 ipc_wwan = kzalloc(sizeof(*ipc_wwan), GFP_KERNEL);
320 if (!ipc_wwan)
321 return NULL;
322
323 ipc_wwan->dev = dev;
324 ipc_wwan->ipc_imem = ipc_imem;
325
326 /* WWAN core will create a netdev for the default IP MUX channel */
327 if (wwan_register_ops(ipc_wwan->dev, &iosm_wwan_ops, ipc_wwan,
328 IP_MUX_SESSION_DEFAULT)) {
329 kfree(ipc_wwan);
330 return NULL;
331 }
332
333 mutex_init(&ipc_wwan->if_mutex);
334
335 return ipc_wwan;
336 }
337
ipc_wwan_deinit(struct iosm_wwan * ipc_wwan)338 void ipc_wwan_deinit(struct iosm_wwan *ipc_wwan)
339 {
340 /* This call will remove all child netdev(s) */
341 wwan_unregister_ops(ipc_wwan->dev);
342
343 mutex_destroy(&ipc_wwan->if_mutex);
344
345 kfree(ipc_wwan);
346 }
347