1 // SPDX-License-Identifier: GPL-2.0
2
3 /* Copyright (c) 2014-2018, The Linux Foundation. All rights reserved.
4 * Copyright (C) 2018-2020 Linaro Ltd.
5 */
6
7 #include <linux/errno.h>
8 #include <linux/if_arp.h>
9 #include <linux/netdevice.h>
10 #include <linux/skbuff.h>
11 #include <linux/if_rmnet.h>
12 #include <linux/remoteproc/qcom_rproc.h>
13
14 #include "ipa.h"
15 #include "ipa_data.h"
16 #include "ipa_endpoint.h"
17 #include "ipa_table.h"
18 #include "ipa_mem.h"
19 #include "ipa_modem.h"
20 #include "ipa_smp2p.h"
21 #include "ipa_qmi.h"
22
23 #define IPA_NETDEV_NAME "rmnet_ipa%d"
24 #define IPA_NETDEV_TAILROOM 0 /* for padding by mux layer */
25 #define IPA_NETDEV_TIMEOUT 10 /* seconds */
26
27 enum ipa_modem_state {
28 IPA_MODEM_STATE_STOPPED = 0,
29 IPA_MODEM_STATE_STARTING,
30 IPA_MODEM_STATE_RUNNING,
31 IPA_MODEM_STATE_STOPPING,
32 };
33
34 /** struct ipa_priv - IPA network device private data */
35 struct ipa_priv {
36 struct ipa *ipa;
37 };
38
39 /** ipa_open() - Opens the modem network interface */
ipa_open(struct net_device * netdev)40 static int ipa_open(struct net_device *netdev)
41 {
42 struct ipa_priv *priv = netdev_priv(netdev);
43 struct ipa *ipa = priv->ipa;
44 int ret;
45
46 ret = ipa_endpoint_enable_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]);
47 if (ret)
48 return ret;
49 ret = ipa_endpoint_enable_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]);
50 if (ret)
51 goto err_disable_tx;
52
53 netif_start_queue(netdev);
54
55 return 0;
56
57 err_disable_tx:
58 ipa_endpoint_disable_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]);
59
60 return ret;
61 }
62
63 /** ipa_stop() - Stops the modem network interface. */
ipa_stop(struct net_device * netdev)64 static int ipa_stop(struct net_device *netdev)
65 {
66 struct ipa_priv *priv = netdev_priv(netdev);
67 struct ipa *ipa = priv->ipa;
68
69 netif_stop_queue(netdev);
70
71 ipa_endpoint_disable_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]);
72 ipa_endpoint_disable_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]);
73
74 return 0;
75 }
76
77 /** ipa_start_xmit() - Transmits an skb.
78 * @skb: skb to be transmitted
79 * @dev: network device
80 *
81 * Return codes:
82 * NETDEV_TX_OK: Success
83 * NETDEV_TX_BUSY: Error while transmitting the skb. Try again later
84 */
ipa_start_xmit(struct sk_buff * skb,struct net_device * netdev)85 static int ipa_start_xmit(struct sk_buff *skb, struct net_device *netdev)
86 {
87 struct net_device_stats *stats = &netdev->stats;
88 struct ipa_priv *priv = netdev_priv(netdev);
89 struct ipa_endpoint *endpoint;
90 struct ipa *ipa = priv->ipa;
91 u32 skb_len = skb->len;
92 int ret;
93
94 if (!skb_len)
95 goto err_drop_skb;
96
97 endpoint = ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX];
98 if (endpoint->data->qmap && skb->protocol != htons(ETH_P_MAP))
99 goto err_drop_skb;
100
101 ret = ipa_endpoint_skb_tx(endpoint, skb);
102 if (ret) {
103 if (ret != -E2BIG)
104 return NETDEV_TX_BUSY;
105 goto err_drop_skb;
106 }
107
108 stats->tx_packets++;
109 stats->tx_bytes += skb_len;
110
111 return NETDEV_TX_OK;
112
113 err_drop_skb:
114 dev_kfree_skb_any(skb);
115 stats->tx_dropped++;
116
117 return NETDEV_TX_OK;
118 }
119
ipa_modem_skb_rx(struct net_device * netdev,struct sk_buff * skb)120 void ipa_modem_skb_rx(struct net_device *netdev, struct sk_buff *skb)
121 {
122 struct net_device_stats *stats = &netdev->stats;
123
124 if (skb) {
125 skb->dev = netdev;
126 skb->protocol = htons(ETH_P_MAP);
127 stats->rx_packets++;
128 stats->rx_bytes += skb->len;
129
130 (void)netif_receive_skb(skb);
131 } else {
132 stats->rx_dropped++;
133 }
134 }
135
136 static const struct net_device_ops ipa_modem_ops = {
137 .ndo_open = ipa_open,
138 .ndo_stop = ipa_stop,
139 .ndo_start_xmit = ipa_start_xmit,
140 };
141
142 /** ipa_modem_netdev_setup() - netdev setup function for the modem */
ipa_modem_netdev_setup(struct net_device * netdev)143 static void ipa_modem_netdev_setup(struct net_device *netdev)
144 {
145 netdev->netdev_ops = &ipa_modem_ops;
146 ether_setup(netdev);
147 /* No header ops (override value set by ether_setup()) */
148 netdev->header_ops = NULL;
149 netdev->type = ARPHRD_RAWIP;
150 netdev->hard_header_len = 0;
151 netdev->max_mtu = IPA_MTU;
152 netdev->mtu = netdev->max_mtu;
153 netdev->addr_len = 0;
154 netdev->flags &= ~(IFF_BROADCAST | IFF_MULTICAST);
155 /* The endpoint is configured for QMAP */
156 netdev->needed_headroom = sizeof(struct rmnet_map_header);
157 netdev->needed_tailroom = IPA_NETDEV_TAILROOM;
158 netdev->watchdog_timeo = IPA_NETDEV_TIMEOUT * HZ;
159 netdev->hw_features = NETIF_F_SG;
160 }
161
162 /** ipa_modem_suspend() - suspend callback
163 * @netdev: Network device
164 *
165 * Suspend the modem's endpoints.
166 */
ipa_modem_suspend(struct net_device * netdev)167 void ipa_modem_suspend(struct net_device *netdev)
168 {
169 struct ipa_priv *priv = netdev_priv(netdev);
170 struct ipa *ipa = priv->ipa;
171
172 netif_stop_queue(netdev);
173
174 ipa_endpoint_suspend_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]);
175 ipa_endpoint_suspend_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]);
176 }
177
178 /** ipa_modem_resume() - resume callback for runtime_pm
179 * @dev: pointer to device
180 *
181 * Resume the modem's endpoints.
182 */
ipa_modem_resume(struct net_device * netdev)183 void ipa_modem_resume(struct net_device *netdev)
184 {
185 struct ipa_priv *priv = netdev_priv(netdev);
186 struct ipa *ipa = priv->ipa;
187
188 ipa_endpoint_resume_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]);
189 ipa_endpoint_resume_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]);
190
191 netif_wake_queue(netdev);
192 }
193
ipa_modem_start(struct ipa * ipa)194 int ipa_modem_start(struct ipa *ipa)
195 {
196 enum ipa_modem_state state;
197 struct net_device *netdev;
198 struct ipa_priv *priv;
199 int ret;
200
201 /* Only attempt to start the modem if it's stopped */
202 state = atomic_cmpxchg(&ipa->modem_state, IPA_MODEM_STATE_STOPPED,
203 IPA_MODEM_STATE_STARTING);
204
205 /* Silently ignore attempts when running, or when changing state */
206 if (state != IPA_MODEM_STATE_STOPPED)
207 return 0;
208
209 netdev = alloc_netdev(sizeof(struct ipa_priv), IPA_NETDEV_NAME,
210 NET_NAME_UNKNOWN, ipa_modem_netdev_setup);
211 if (!netdev) {
212 ret = -ENOMEM;
213 goto out_set_state;
214 }
215
216 ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]->netdev = netdev;
217 ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]->netdev = netdev;
218
219 priv = netdev_priv(netdev);
220 priv->ipa = ipa;
221
222 ret = register_netdev(netdev);
223 if (ret)
224 free_netdev(netdev);
225 else
226 ipa->modem_netdev = netdev;
227
228 out_set_state:
229 if (ret)
230 atomic_set(&ipa->modem_state, IPA_MODEM_STATE_STOPPED);
231 else
232 atomic_set(&ipa->modem_state, IPA_MODEM_STATE_RUNNING);
233 smp_mb__after_atomic();
234
235 return ret;
236 }
237
ipa_modem_stop(struct ipa * ipa)238 int ipa_modem_stop(struct ipa *ipa)
239 {
240 struct net_device *netdev = ipa->modem_netdev;
241 enum ipa_modem_state state;
242 int ret;
243
244 /* Only attempt to stop the modem if it's running */
245 state = atomic_cmpxchg(&ipa->modem_state, IPA_MODEM_STATE_RUNNING,
246 IPA_MODEM_STATE_STOPPING);
247
248 /* Silently ignore attempts when already stopped */
249 if (state == IPA_MODEM_STATE_STOPPED)
250 return 0;
251
252 /* If we're somewhere between stopped and starting, we're busy */
253 if (state != IPA_MODEM_STATE_RUNNING)
254 return -EBUSY;
255
256 /* Prevent the modem from triggering a call to ipa_setup() */
257 ipa_smp2p_disable(ipa);
258
259 if (netdev) {
260 /* Stop the queue and disable the endpoints if it's open */
261 ret = ipa_stop(netdev);
262 if (ret)
263 goto out_set_state;
264
265 ipa->modem_netdev = NULL;
266 unregister_netdev(netdev);
267 free_netdev(netdev);
268 } else {
269 ret = 0;
270 }
271
272 out_set_state:
273 if (ret)
274 atomic_set(&ipa->modem_state, IPA_MODEM_STATE_RUNNING);
275 else
276 atomic_set(&ipa->modem_state, IPA_MODEM_STATE_STOPPED);
277 smp_mb__after_atomic();
278
279 return ret;
280 }
281
282 /* Treat a "clean" modem stop the same as a crash */
ipa_modem_crashed(struct ipa * ipa)283 static void ipa_modem_crashed(struct ipa *ipa)
284 {
285 struct device *dev = &ipa->pdev->dev;
286 int ret;
287
288 ipa_endpoint_modem_pause_all(ipa, true);
289
290 ipa_endpoint_modem_hol_block_clear_all(ipa);
291
292 ipa_table_reset(ipa, true);
293
294 ret = ipa_table_hash_flush(ipa);
295 if (ret)
296 dev_err(dev, "error %d flushing hash caches\n", ret);
297
298 ret = ipa_endpoint_modem_exception_reset_all(ipa);
299 if (ret)
300 dev_err(dev, "error %d resetting exception endpoint\n", ret);
301
302 ipa_endpoint_modem_pause_all(ipa, false);
303
304 ret = ipa_modem_stop(ipa);
305 if (ret)
306 dev_err(dev, "error %d stopping modem\n", ret);
307
308 /* Now prepare for the next modem boot */
309 ret = ipa_mem_zero_modem(ipa);
310 if (ret)
311 dev_err(dev, "error %d zeroing modem memory regions\n", ret);
312 }
313
ipa_modem_notify(struct notifier_block * nb,unsigned long action,void * data)314 static int ipa_modem_notify(struct notifier_block *nb, unsigned long action,
315 void *data)
316 {
317 struct ipa *ipa = container_of(nb, struct ipa, nb);
318 struct qcom_ssr_notify_data *notify_data = data;
319 struct device *dev = &ipa->pdev->dev;
320
321 switch (action) {
322 case QCOM_SSR_BEFORE_POWERUP:
323 dev_info(dev, "received modem starting event\n");
324 ipa_smp2p_notify_reset(ipa);
325 break;
326
327 case QCOM_SSR_AFTER_POWERUP:
328 dev_info(dev, "received modem running event\n");
329 break;
330
331 case QCOM_SSR_BEFORE_SHUTDOWN:
332 dev_info(dev, "received modem %s event\n",
333 notify_data->crashed ? "crashed" : "stopping");
334 if (ipa->setup_complete)
335 ipa_modem_crashed(ipa);
336 break;
337
338 case QCOM_SSR_AFTER_SHUTDOWN:
339 dev_info(dev, "received modem offline event\n");
340 break;
341
342 default:
343 dev_err(dev, "received unrecognized event %lu\n", action);
344 break;
345 }
346
347 return NOTIFY_OK;
348 }
349
ipa_modem_init(struct ipa * ipa,bool modem_init)350 int ipa_modem_init(struct ipa *ipa, bool modem_init)
351 {
352 return ipa_smp2p_init(ipa, modem_init);
353 }
354
ipa_modem_exit(struct ipa * ipa)355 void ipa_modem_exit(struct ipa *ipa)
356 {
357 ipa_smp2p_exit(ipa);
358 }
359
ipa_modem_config(struct ipa * ipa)360 int ipa_modem_config(struct ipa *ipa)
361 {
362 void *notifier;
363
364 ipa->nb.notifier_call = ipa_modem_notify;
365
366 notifier = qcom_register_ssr_notifier("mpss", &ipa->nb);
367 if (IS_ERR(notifier))
368 return PTR_ERR(notifier);
369
370 ipa->notifier = notifier;
371
372 return 0;
373 }
374
ipa_modem_deconfig(struct ipa * ipa)375 void ipa_modem_deconfig(struct ipa *ipa)
376 {
377 struct device *dev = &ipa->pdev->dev;
378 int ret;
379
380 ret = qcom_unregister_ssr_notifier(ipa->notifier, &ipa->nb);
381 if (ret)
382 dev_err(dev, "error %d unregistering notifier", ret);
383
384 ipa->notifier = NULL;
385 memset(&ipa->nb, 0, sizeof(ipa->nb));
386 }
387
ipa_modem_setup(struct ipa * ipa)388 int ipa_modem_setup(struct ipa *ipa)
389 {
390 return ipa_qmi_setup(ipa);
391 }
392
ipa_modem_teardown(struct ipa * ipa)393 void ipa_modem_teardown(struct ipa *ipa)
394 {
395 ipa_qmi_teardown(ipa);
396 }
397