1 // SPDX-License-Identifier: GPL-2.0
2
3 /* Copyright (c) 2014-2018, The Linux Foundation. All rights reserved.
4 * Copyright (C) 2018-2022 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/etherdevice.h>
13 #include <net/pkt_sched.h>
14 #include <linux/pm_runtime.h>
15 #include <linux/remoteproc/qcom_rproc.h>
16
17 #include "ipa.h"
18 #include "ipa_data.h"
19 #include "ipa_endpoint.h"
20 #include "ipa_table.h"
21 #include "ipa_mem.h"
22 #include "ipa_modem.h"
23 #include "ipa_smp2p.h"
24 #include "ipa_qmi.h"
25 #include "ipa_uc.h"
26 #include "ipa_power.h"
27
28 #define IPA_NETDEV_NAME "rmnet_ipa%d"
29 #define IPA_NETDEV_TAILROOM 0 /* for padding by mux layer */
30 #define IPA_NETDEV_TIMEOUT 10 /* seconds */
31
32 enum ipa_modem_state {
33 IPA_MODEM_STATE_STOPPED = 0,
34 IPA_MODEM_STATE_STARTING,
35 IPA_MODEM_STATE_RUNNING,
36 IPA_MODEM_STATE_STOPPING,
37 };
38
39 /**
40 * struct ipa_priv - IPA network device private data
41 * @ipa: IPA pointer
42 * @work: Work structure used to wake the modem netdev TX queue
43 */
44 struct ipa_priv {
45 struct ipa *ipa;
46 struct work_struct work;
47 };
48
49 /** ipa_open() - Opens the modem network interface */
ipa_open(struct net_device * netdev)50 static int ipa_open(struct net_device *netdev)
51 {
52 struct ipa_priv *priv = netdev_priv(netdev);
53 struct ipa *ipa = priv->ipa;
54 struct device *dev;
55 int ret;
56
57 dev = &ipa->pdev->dev;
58 ret = pm_runtime_get_sync(dev);
59 if (ret < 0)
60 goto err_power_put;
61
62 ret = ipa_endpoint_enable_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]);
63 if (ret)
64 goto err_power_put;
65
66 ret = ipa_endpoint_enable_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]);
67 if (ret)
68 goto err_disable_tx;
69
70 netif_start_queue(netdev);
71
72 pm_runtime_mark_last_busy(dev);
73 (void)pm_runtime_put_autosuspend(dev);
74
75 return 0;
76
77 err_disable_tx:
78 ipa_endpoint_disable_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]);
79 err_power_put:
80 pm_runtime_put_noidle(dev);
81
82 return ret;
83 }
84
85 /** ipa_stop() - Stops the modem network interface. */
ipa_stop(struct net_device * netdev)86 static int ipa_stop(struct net_device *netdev)
87 {
88 struct ipa_priv *priv = netdev_priv(netdev);
89 struct ipa *ipa = priv->ipa;
90 struct device *dev;
91 int ret;
92
93 dev = &ipa->pdev->dev;
94 ret = pm_runtime_get_sync(dev);
95 if (ret < 0)
96 goto out_power_put;
97
98 netif_stop_queue(netdev);
99
100 ipa_endpoint_disable_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]);
101 ipa_endpoint_disable_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]);
102 out_power_put:
103 pm_runtime_mark_last_busy(dev);
104 (void)pm_runtime_put_autosuspend(dev);
105
106 return 0;
107 }
108
109 /** ipa_start_xmit() - Transmits an skb.
110 * @skb: skb to be transmitted
111 * @dev: network device
112 *
113 * Return codes:
114 * NETDEV_TX_OK: Success
115 * NETDEV_TX_BUSY: Error while transmitting the skb. Try again later
116 */
117 static netdev_tx_t
ipa_start_xmit(struct sk_buff * skb,struct net_device * netdev)118 ipa_start_xmit(struct sk_buff *skb, struct net_device *netdev)
119 {
120 struct net_device_stats *stats = &netdev->stats;
121 struct ipa_priv *priv = netdev_priv(netdev);
122 struct ipa_endpoint *endpoint;
123 struct ipa *ipa = priv->ipa;
124 u32 skb_len = skb->len;
125 struct device *dev;
126 int ret;
127
128 if (!skb_len)
129 goto err_drop_skb;
130
131 endpoint = ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX];
132 if (endpoint->config.qmap && skb->protocol != htons(ETH_P_MAP))
133 goto err_drop_skb;
134
135 /* The hardware must be powered for us to transmit */
136 dev = &ipa->pdev->dev;
137 ret = pm_runtime_get(dev);
138 if (ret < 1) {
139 /* If a resume won't happen, just drop the packet */
140 if (ret < 0 && ret != -EINPROGRESS) {
141 ipa_power_modem_queue_active(ipa);
142 pm_runtime_put_noidle(dev);
143 goto err_drop_skb;
144 }
145
146 /* No power (yet). Stop the network stack from transmitting
147 * until we're resumed; ipa_modem_resume() arranges for the
148 * TX queue to be started again.
149 */
150 ipa_power_modem_queue_stop(ipa);
151
152 pm_runtime_put_noidle(dev);
153
154 return NETDEV_TX_BUSY;
155 }
156
157 ipa_power_modem_queue_active(ipa);
158
159 ret = ipa_endpoint_skb_tx(endpoint, skb);
160
161 pm_runtime_mark_last_busy(dev);
162 (void)pm_runtime_put_autosuspend(dev);
163
164 if (ret) {
165 if (ret != -E2BIG)
166 return NETDEV_TX_BUSY;
167 goto err_drop_skb;
168 }
169
170 stats->tx_packets++;
171 stats->tx_bytes += skb_len;
172
173 return NETDEV_TX_OK;
174
175 err_drop_skb:
176 dev_kfree_skb_any(skb);
177 stats->tx_dropped++;
178
179 return NETDEV_TX_OK;
180 }
181
ipa_modem_skb_rx(struct net_device * netdev,struct sk_buff * skb)182 void ipa_modem_skb_rx(struct net_device *netdev, struct sk_buff *skb)
183 {
184 struct net_device_stats *stats = &netdev->stats;
185
186 if (skb) {
187 skb->dev = netdev;
188 skb->protocol = htons(ETH_P_MAP);
189 stats->rx_packets++;
190 stats->rx_bytes += skb->len;
191
192 (void)netif_receive_skb(skb);
193 } else {
194 stats->rx_dropped++;
195 }
196 }
197
198 static const struct net_device_ops ipa_modem_ops = {
199 .ndo_open = ipa_open,
200 .ndo_stop = ipa_stop,
201 .ndo_start_xmit = ipa_start_xmit,
202 };
203
204 /** ipa_modem_netdev_setup() - netdev setup function for the modem */
ipa_modem_netdev_setup(struct net_device * netdev)205 static void ipa_modem_netdev_setup(struct net_device *netdev)
206 {
207 netdev->netdev_ops = &ipa_modem_ops;
208
209 netdev->header_ops = NULL;
210 netdev->type = ARPHRD_RAWIP;
211 netdev->hard_header_len = 0;
212 netdev->min_header_len = ETH_HLEN;
213 netdev->min_mtu = ETH_MIN_MTU;
214 netdev->max_mtu = IPA_MTU;
215 netdev->mtu = netdev->max_mtu;
216 netdev->addr_len = 0;
217 netdev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
218 netdev->flags &= ~(IFF_BROADCAST | IFF_MULTICAST);
219 netdev->priv_flags |= IFF_TX_SKB_SHARING;
220 eth_broadcast_addr(netdev->broadcast);
221
222 /* The endpoint is configured for QMAP */
223 netdev->needed_headroom = sizeof(struct rmnet_map_header);
224 netdev->needed_tailroom = IPA_NETDEV_TAILROOM;
225 netdev->watchdog_timeo = IPA_NETDEV_TIMEOUT * HZ;
226 netdev->hw_features = NETIF_F_SG;
227 }
228
229 /** ipa_modem_suspend() - suspend callback
230 * @netdev: Network device
231 *
232 * Suspend the modem's endpoints.
233 */
ipa_modem_suspend(struct net_device * netdev)234 void ipa_modem_suspend(struct net_device *netdev)
235 {
236 struct ipa_priv *priv = netdev_priv(netdev);
237 struct ipa *ipa = priv->ipa;
238
239 if (!(netdev->flags & IFF_UP))
240 return;
241
242 ipa_endpoint_suspend_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]);
243 ipa_endpoint_suspend_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]);
244 }
245
246 /**
247 * ipa_modem_wake_queue_work() - enable modem netdev queue
248 * @work: Work structure
249 *
250 * Re-enable transmit on the modem network device. This is called
251 * in (power management) work queue context, scheduled when resuming
252 * the modem. We can't enable the queue directly in ipa_modem_resume()
253 * because transmits restart the instant the queue is awakened; but the
254 * device power state won't be ACTIVE until *after* ipa_modem_resume()
255 * returns.
256 */
ipa_modem_wake_queue_work(struct work_struct * work)257 static void ipa_modem_wake_queue_work(struct work_struct *work)
258 {
259 struct ipa_priv *priv = container_of(work, struct ipa_priv, work);
260
261 ipa_power_modem_queue_wake(priv->ipa);
262 }
263
264 /** ipa_modem_resume() - resume callback for runtime_pm
265 * @dev: pointer to device
266 *
267 * Resume the modem's endpoints.
268 */
ipa_modem_resume(struct net_device * netdev)269 void ipa_modem_resume(struct net_device *netdev)
270 {
271 struct ipa_priv *priv = netdev_priv(netdev);
272 struct ipa *ipa = priv->ipa;
273
274 if (!(netdev->flags & IFF_UP))
275 return;
276
277 ipa_endpoint_resume_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]);
278 ipa_endpoint_resume_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]);
279
280 /* Arrange for the TX queue to be restarted */
281 (void)queue_pm_work(&priv->work);
282 }
283
ipa_modem_start(struct ipa * ipa)284 int ipa_modem_start(struct ipa *ipa)
285 {
286 enum ipa_modem_state state;
287 struct net_device *netdev;
288 struct ipa_priv *priv;
289 int ret;
290
291 /* Only attempt to start the modem if it's stopped */
292 state = atomic_cmpxchg(&ipa->modem_state, IPA_MODEM_STATE_STOPPED,
293 IPA_MODEM_STATE_STARTING);
294
295 /* Silently ignore attempts when running, or when changing state */
296 if (state != IPA_MODEM_STATE_STOPPED)
297 return 0;
298
299 netdev = alloc_netdev(sizeof(struct ipa_priv), IPA_NETDEV_NAME,
300 NET_NAME_UNKNOWN, ipa_modem_netdev_setup);
301 if (!netdev) {
302 ret = -ENOMEM;
303 goto out_set_state;
304 }
305
306 SET_NETDEV_DEV(netdev, &ipa->pdev->dev);
307 priv = netdev_priv(netdev);
308 priv->ipa = ipa;
309 INIT_WORK(&priv->work, ipa_modem_wake_queue_work);
310 ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]->netdev = netdev;
311 ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]->netdev = netdev;
312 ipa->modem_netdev = netdev;
313
314 ret = register_netdev(netdev);
315 if (ret) {
316 ipa->modem_netdev = NULL;
317 ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]->netdev = NULL;
318 ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]->netdev = NULL;
319 free_netdev(netdev);
320 }
321
322 out_set_state:
323 if (ret)
324 atomic_set(&ipa->modem_state, IPA_MODEM_STATE_STOPPED);
325 else
326 atomic_set(&ipa->modem_state, IPA_MODEM_STATE_RUNNING);
327 smp_mb__after_atomic();
328
329 return ret;
330 }
331
ipa_modem_stop(struct ipa * ipa)332 int ipa_modem_stop(struct ipa *ipa)
333 {
334 struct net_device *netdev = ipa->modem_netdev;
335 enum ipa_modem_state state;
336
337 /* Only attempt to stop the modem if it's running */
338 state = atomic_cmpxchg(&ipa->modem_state, IPA_MODEM_STATE_RUNNING,
339 IPA_MODEM_STATE_STOPPING);
340
341 /* Silently ignore attempts when already stopped */
342 if (state == IPA_MODEM_STATE_STOPPED)
343 return 0;
344
345 /* If we're somewhere between stopped and starting, we're busy */
346 if (state != IPA_MODEM_STATE_RUNNING)
347 return -EBUSY;
348
349 /* Clean up the netdev and endpoints if it was started */
350 if (netdev) {
351 struct ipa_priv *priv = netdev_priv(netdev);
352
353 cancel_work_sync(&priv->work);
354 /* If it was opened, stop it first */
355 if (netdev->flags & IFF_UP)
356 (void)ipa_stop(netdev);
357 unregister_netdev(netdev);
358 ipa->modem_netdev = NULL;
359 ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]->netdev = NULL;
360 ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]->netdev = NULL;
361 free_netdev(netdev);
362 }
363
364 atomic_set(&ipa->modem_state, IPA_MODEM_STATE_STOPPED);
365 smp_mb__after_atomic();
366
367 return 0;
368 }
369
370 /* Treat a "clean" modem stop the same as a crash */
ipa_modem_crashed(struct ipa * ipa)371 static void ipa_modem_crashed(struct ipa *ipa)
372 {
373 struct device *dev = &ipa->pdev->dev;
374 int ret;
375
376 /* Prevent the modem from triggering a call to ipa_setup() */
377 ipa_smp2p_irq_disable_setup(ipa);
378
379 ret = pm_runtime_get_sync(dev);
380 if (ret < 0) {
381 dev_err(dev, "error %d getting power to handle crash\n", ret);
382 goto out_power_put;
383 }
384
385 ipa_endpoint_modem_pause_all(ipa, true);
386
387 ipa_endpoint_modem_hol_block_clear_all(ipa);
388
389 ipa_table_reset(ipa, true);
390
391 ret = ipa_table_hash_flush(ipa);
392 if (ret)
393 dev_err(dev, "error %d flushing hash caches\n", ret);
394
395 ret = ipa_endpoint_modem_exception_reset_all(ipa);
396 if (ret)
397 dev_err(dev, "error %d resetting exception endpoint\n", ret);
398
399 ipa_endpoint_modem_pause_all(ipa, false);
400
401 ret = ipa_modem_stop(ipa);
402 if (ret)
403 dev_err(dev, "error %d stopping modem\n", ret);
404
405 /* Now prepare for the next modem boot */
406 ret = ipa_mem_zero_modem(ipa);
407 if (ret)
408 dev_err(dev, "error %d zeroing modem memory regions\n", ret);
409
410 out_power_put:
411 pm_runtime_mark_last_busy(dev);
412 (void)pm_runtime_put_autosuspend(dev);
413 }
414
ipa_modem_notify(struct notifier_block * nb,unsigned long action,void * data)415 static int ipa_modem_notify(struct notifier_block *nb, unsigned long action,
416 void *data)
417 {
418 struct ipa *ipa = container_of(nb, struct ipa, nb);
419 struct qcom_ssr_notify_data *notify_data = data;
420 struct device *dev = &ipa->pdev->dev;
421
422 switch (action) {
423 case QCOM_SSR_BEFORE_POWERUP:
424 dev_info(dev, "received modem starting event\n");
425 ipa_uc_power(ipa);
426 ipa_smp2p_notify_reset(ipa);
427 break;
428
429 case QCOM_SSR_AFTER_POWERUP:
430 dev_info(dev, "received modem running event\n");
431 break;
432
433 case QCOM_SSR_BEFORE_SHUTDOWN:
434 dev_info(dev, "received modem %s event\n",
435 notify_data->crashed ? "crashed" : "stopping");
436 if (ipa->setup_complete)
437 ipa_modem_crashed(ipa);
438 break;
439
440 case QCOM_SSR_AFTER_SHUTDOWN:
441 dev_info(dev, "received modem offline event\n");
442 break;
443
444 default:
445 dev_err(dev, "received unrecognized event %lu\n", action);
446 break;
447 }
448
449 return NOTIFY_OK;
450 }
451
ipa_modem_config(struct ipa * ipa)452 int ipa_modem_config(struct ipa *ipa)
453 {
454 void *notifier;
455
456 ipa->nb.notifier_call = ipa_modem_notify;
457
458 notifier = qcom_register_ssr_notifier("mpss", &ipa->nb);
459 if (IS_ERR(notifier))
460 return PTR_ERR(notifier);
461
462 ipa->notifier = notifier;
463
464 return 0;
465 }
466
ipa_modem_deconfig(struct ipa * ipa)467 void ipa_modem_deconfig(struct ipa *ipa)
468 {
469 struct device *dev = &ipa->pdev->dev;
470 int ret;
471
472 ret = qcom_unregister_ssr_notifier(ipa->notifier, &ipa->nb);
473 if (ret)
474 dev_err(dev, "error %d unregistering notifier", ret);
475
476 ipa->notifier = NULL;
477 memset(&ipa->nb, 0, sizeof(ipa->nb));
478 }
479