1 // SPDX-License-Identifier: GPL-2.0
2
3 /* Copyright (c) 2014-2018, The Linux Foundation. All rights reserved.
4 * Copyright (C) 2018-2024 Linaro Ltd.
5 */
6
7 #include <linux/errno.h>
8 #include <linux/etherdevice.h>
9 #include <linux/if_arp.h>
10 #include <linux/if_rmnet.h>
11 #include <linux/netdevice.h>
12 #include <linux/pm_runtime.h>
13 #include <linux/skbuff.h>
14 #include <net/pkt_sched.h>
15
16 #include <linux/remoteproc/qcom_rproc.h>
17
18 #include "ipa.h"
19 #include "ipa_endpoint.h"
20 #include "ipa_mem.h"
21 #include "ipa_modem.h"
22 #include "ipa_smp2p.h"
23 #include "ipa_table.h"
24 #include "ipa_uc.h"
25
26 #define IPA_NETDEV_NAME "rmnet_ipa%d"
27 #define IPA_NETDEV_TAILROOM 0 /* for padding by mux layer */
28 #define IPA_NETDEV_TIMEOUT 10 /* seconds */
29
30 enum ipa_modem_state {
31 IPA_MODEM_STATE_STOPPED = 0,
32 IPA_MODEM_STATE_STARTING,
33 IPA_MODEM_STATE_RUNNING,
34 IPA_MODEM_STATE_STOPPING,
35 };
36
37 /**
38 * struct ipa_priv - IPA network device private data
39 * @ipa: IPA pointer
40 * @tx: Transmit endpoint pointer
41 * @rx: Receive endpoint pointer
42 * @work: Work structure used to wake the modem netdev TX queue
43 */
44 struct ipa_priv {
45 struct ipa *ipa;
46 struct ipa_endpoint *tx;
47 struct ipa_endpoint *rx;
48 struct work_struct work;
49 };
50
51 /** ipa_open() - Opens the modem network interface */
ipa_open(struct net_device * netdev)52 static int ipa_open(struct net_device *netdev)
53 {
54 struct ipa_priv *priv = netdev_priv(netdev);
55 struct ipa *ipa = priv->ipa;
56 struct device *dev;
57 int ret;
58
59 dev = ipa->dev;
60 ret = pm_runtime_get_sync(dev);
61 if (ret < 0)
62 goto err_power_put;
63
64 ret = ipa_endpoint_enable_one(priv->tx);
65 if (ret)
66 goto err_power_put;
67
68 ret = ipa_endpoint_enable_one(priv->rx);
69 if (ret)
70 goto err_disable_tx;
71
72 netif_start_queue(netdev);
73
74 pm_runtime_mark_last_busy(dev);
75 (void)pm_runtime_put_autosuspend(dev);
76
77 return 0;
78
79 err_disable_tx:
80 ipa_endpoint_disable_one(priv->tx);
81 err_power_put:
82 pm_runtime_put_noidle(dev);
83
84 return ret;
85 }
86
87 /** ipa_stop() - Stops the modem network interface. */
ipa_stop(struct net_device * netdev)88 static int ipa_stop(struct net_device *netdev)
89 {
90 struct ipa_priv *priv = netdev_priv(netdev);
91 struct ipa *ipa = priv->ipa;
92 struct device *dev;
93 int ret;
94
95 dev = ipa->dev;
96 ret = pm_runtime_get_sync(dev);
97 if (ret < 0)
98 goto out_power_put;
99
100 netif_stop_queue(netdev);
101
102 ipa_endpoint_disable_one(priv->rx);
103 ipa_endpoint_disable_one(priv->tx);
104 out_power_put:
105 pm_runtime_mark_last_busy(dev);
106 (void)pm_runtime_put_autosuspend(dev);
107
108 return 0;
109 }
110
111 /** ipa_start_xmit() - Transmit an skb
112 * @skb: Socket buffer to be transmitted
113 * @netdev: Network device
114 *
115 * Return: NETDEV_TX_OK if successful (or dropped), NETDEV_TX_BUSY otherwise
116
117 * Normally NETDEV_TX_OK indicates the buffer was successfully transmitted.
118 * If the buffer has an unexpected protocol or its size is out of range it
119 * is quietly dropped, returning NETDEV_TX_OK. NETDEV_TX_BUSY indicates
120 * the buffer cannot be sent at this time and should retried later.
121 */
122 static netdev_tx_t
ipa_start_xmit(struct sk_buff * skb,struct net_device * netdev)123 ipa_start_xmit(struct sk_buff *skb, struct net_device *netdev)
124 {
125 struct net_device_stats *stats = &netdev->stats;
126 struct ipa_priv *priv = netdev_priv(netdev);
127 struct ipa_endpoint *endpoint;
128 struct ipa *ipa = priv->ipa;
129 u32 skb_len = skb->len;
130 struct device *dev;
131 int ret;
132
133 if (!skb_len)
134 goto err_drop_skb;
135
136 endpoint = ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX];
137 if (endpoint->config.qmap && skb->protocol != htons(ETH_P_MAP))
138 goto err_drop_skb;
139
140 /* The hardware must be powered for us to transmit, so if we're not
141 * ready we want the network stack to stop queueing until power is
142 * ACTIVE. Once runtime resume has completed, we inform the network
143 * stack it's OK to try transmitting again.
144 *
145 * We learn from pm_runtime_get() whether the hardware is powered.
146 * If it was not, powering up is either started or already underway.
147 * And in that case we want to disable queueing, expecting it to be
148 * re-enabled once power is ACTIVE. But runtime PM and network
149 * transmit run concurrently, and if we're not careful the requests
150 * to stop and start queueing could occur in the wrong order.
151 *
152 * For that reason we *always* stop queueing here, *before* the call
153 * to pm_runtime_get(). If we determine here that power is ACTIVE,
154 * we restart queueing before transmitting the SKB. Otherwise
155 * queueing will eventually be enabled after resume completes.
156 */
157 netif_stop_queue(netdev);
158
159 dev = ipa->dev;
160 ret = pm_runtime_get(dev);
161 if (ret < 1) {
162 /* If a resume won't happen, just drop the packet */
163 if (ret < 0 && ret != -EINPROGRESS) {
164 netif_wake_queue(netdev);
165 pm_runtime_put_noidle(dev);
166 goto err_drop_skb;
167 }
168
169 pm_runtime_put_noidle(dev);
170
171 return NETDEV_TX_BUSY;
172 }
173
174 netif_wake_queue(netdev);
175
176 ret = ipa_endpoint_skb_tx(endpoint, skb);
177
178 pm_runtime_mark_last_busy(dev);
179 (void)pm_runtime_put_autosuspend(dev);
180
181 if (ret) {
182 if (ret != -E2BIG)
183 return NETDEV_TX_BUSY;
184 goto err_drop_skb;
185 }
186
187 stats->tx_packets++;
188 stats->tx_bytes += skb_len;
189
190 return NETDEV_TX_OK;
191
192 err_drop_skb:
193 dev_kfree_skb_any(skb);
194 stats->tx_dropped++;
195
196 return NETDEV_TX_OK;
197 }
198
ipa_modem_skb_rx(struct net_device * netdev,struct sk_buff * skb)199 void ipa_modem_skb_rx(struct net_device *netdev, struct sk_buff *skb)
200 {
201 struct net_device_stats *stats = &netdev->stats;
202
203 if (skb) {
204 skb->dev = netdev;
205 skb->protocol = htons(ETH_P_MAP);
206 stats->rx_packets++;
207 stats->rx_bytes += skb->len;
208
209 (void)netif_receive_skb(skb);
210 } else {
211 stats->rx_dropped++;
212 }
213 }
214
215 static const struct net_device_ops ipa_modem_ops = {
216 .ndo_open = ipa_open,
217 .ndo_stop = ipa_stop,
218 .ndo_start_xmit = ipa_start_xmit,
219 };
220
221 /** ipa_modem_netdev_setup() - netdev setup function for the modem */
ipa_modem_netdev_setup(struct net_device * netdev)222 static void ipa_modem_netdev_setup(struct net_device *netdev)
223 {
224 netdev->netdev_ops = &ipa_modem_ops;
225
226 netdev->header_ops = NULL;
227 netdev->type = ARPHRD_RAWIP;
228 netdev->hard_header_len = 0;
229 netdev->min_header_len = ETH_HLEN;
230 netdev->min_mtu = ETH_MIN_MTU;
231 netdev->max_mtu = IPA_MTU;
232 netdev->mtu = netdev->max_mtu;
233 netdev->addr_len = 0;
234 netdev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
235 netdev->flags &= ~(IFF_BROADCAST | IFF_MULTICAST);
236 netdev->priv_flags |= IFF_TX_SKB_SHARING;
237 eth_broadcast_addr(netdev->broadcast);
238
239 /* The endpoint is configured for QMAP */
240 netdev->needed_headroom = sizeof(struct rmnet_map_header);
241 netdev->needed_tailroom = IPA_NETDEV_TAILROOM;
242 netdev->watchdog_timeo = IPA_NETDEV_TIMEOUT * HZ;
243 netdev->hw_features = NETIF_F_SG;
244 }
245
246 /** ipa_modem_suspend() - suspend callback
247 * @netdev: Network device
248 *
249 * Suspend the modem's endpoints.
250 */
ipa_modem_suspend(struct net_device * netdev)251 void ipa_modem_suspend(struct net_device *netdev)
252 {
253 struct ipa_priv *priv;
254
255 if (!(netdev->flags & IFF_UP))
256 return;
257
258 priv = netdev_priv(netdev);
259 ipa_endpoint_suspend_one(priv->rx);
260 ipa_endpoint_suspend_one(priv->tx);
261 }
262
263 /**
264 * ipa_modem_wake_queue_work() - enable modem netdev queue
265 * @work: Work structure
266 *
267 * Re-enable transmit on the modem network device. This is called
268 * in (power management) work queue context, scheduled when resuming
269 * the modem. We can't enable the queue directly in ipa_modem_resume()
270 * because transmits restart the instant the queue is awakened; but the
271 * device power state won't be ACTIVE until *after* ipa_modem_resume()
272 * returns.
273 */
ipa_modem_wake_queue_work(struct work_struct * work)274 static void ipa_modem_wake_queue_work(struct work_struct *work)
275 {
276 struct ipa_priv *priv = container_of(work, struct ipa_priv, work);
277
278 netif_wake_queue(priv->tx->netdev);
279 }
280
281 /** ipa_modem_resume() - resume callback for runtime_pm
282 * @dev: pointer to device
283 *
284 * Resume the modem's endpoints.
285 */
ipa_modem_resume(struct net_device * netdev)286 void ipa_modem_resume(struct net_device *netdev)
287 {
288 struct ipa_priv *priv;
289
290 if (!(netdev->flags & IFF_UP))
291 return;
292
293 priv = netdev_priv(netdev);
294 ipa_endpoint_resume_one(priv->tx);
295 ipa_endpoint_resume_one(priv->rx);
296
297 /* Arrange for the TX queue to be restarted */
298 (void)queue_pm_work(&priv->work);
299 }
300
ipa_modem_start(struct ipa * ipa)301 int ipa_modem_start(struct ipa *ipa)
302 {
303 enum ipa_modem_state state;
304 struct net_device *netdev;
305 struct ipa_priv *priv;
306 int ret;
307
308 /* Only attempt to start the modem if it's stopped */
309 state = atomic_cmpxchg(&ipa->modem_state, IPA_MODEM_STATE_STOPPED,
310 IPA_MODEM_STATE_STARTING);
311
312 /* Silently ignore attempts when running, or when changing state */
313 if (state != IPA_MODEM_STATE_STOPPED)
314 return 0;
315
316 netdev = alloc_netdev(sizeof(struct ipa_priv), IPA_NETDEV_NAME,
317 NET_NAME_UNKNOWN, ipa_modem_netdev_setup);
318 if (!netdev) {
319 ret = -ENOMEM;
320 goto out_set_state;
321 }
322
323 SET_NETDEV_DEV(netdev, ipa->dev);
324 priv = netdev_priv(netdev);
325 priv->ipa = ipa;
326 priv->tx = ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX];
327 priv->rx = ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX];
328 INIT_WORK(&priv->work, ipa_modem_wake_queue_work);
329
330 priv->tx->netdev = netdev;
331 priv->rx->netdev = netdev;
332
333 ipa->modem_netdev = netdev;
334
335 ret = register_netdev(netdev);
336 if (ret) {
337 ipa->modem_netdev = NULL;
338 priv->rx->netdev = NULL;
339 priv->tx->netdev = NULL;
340
341 free_netdev(netdev);
342 }
343
344 out_set_state:
345 if (ret)
346 atomic_set(&ipa->modem_state, IPA_MODEM_STATE_STOPPED);
347 else
348 atomic_set(&ipa->modem_state, IPA_MODEM_STATE_RUNNING);
349 smp_mb__after_atomic();
350
351 return ret;
352 }
353
ipa_modem_stop(struct ipa * ipa)354 int ipa_modem_stop(struct ipa *ipa)
355 {
356 struct net_device *netdev = ipa->modem_netdev;
357 enum ipa_modem_state state;
358
359 /* Only attempt to stop the modem if it's running */
360 state = atomic_cmpxchg(&ipa->modem_state, IPA_MODEM_STATE_RUNNING,
361 IPA_MODEM_STATE_STOPPING);
362
363 /* Silently ignore attempts when already stopped */
364 if (state == IPA_MODEM_STATE_STOPPED)
365 return 0;
366
367 /* If we're somewhere between stopped and starting, we're busy */
368 if (state != IPA_MODEM_STATE_RUNNING)
369 return -EBUSY;
370
371 /* Clean up the netdev and endpoints if it was started */
372 if (netdev) {
373 struct ipa_priv *priv = netdev_priv(netdev);
374
375 cancel_work_sync(&priv->work);
376 /* If it was opened, stop it first */
377 if (netdev->flags & IFF_UP)
378 (void)ipa_stop(netdev);
379 unregister_netdev(netdev);
380
381 ipa->modem_netdev = NULL;
382 priv->rx->netdev = NULL;
383 priv->tx->netdev = NULL;
384
385 free_netdev(netdev);
386 }
387
388 atomic_set(&ipa->modem_state, IPA_MODEM_STATE_STOPPED);
389 smp_mb__after_atomic();
390
391 return 0;
392 }
393
394 /* Treat a "clean" modem stop the same as a crash */
ipa_modem_crashed(struct ipa * ipa)395 static void ipa_modem_crashed(struct ipa *ipa)
396 {
397 struct device *dev = ipa->dev;
398 int ret;
399
400 /* Prevent the modem from triggering a call to ipa_setup() */
401 ipa_smp2p_irq_disable_setup(ipa);
402
403 ret = pm_runtime_get_sync(dev);
404 if (ret < 0) {
405 dev_err(dev, "error %d getting power to handle crash\n", ret);
406 goto out_power_put;
407 }
408
409 ipa_endpoint_modem_pause_all(ipa, true);
410
411 ipa_endpoint_modem_hol_block_clear_all(ipa);
412
413 ipa_table_reset(ipa, true);
414
415 ret = ipa_table_hash_flush(ipa);
416 if (ret)
417 dev_err(dev, "error %d flushing hash caches\n", ret);
418
419 ret = ipa_endpoint_modem_exception_reset_all(ipa);
420 if (ret)
421 dev_err(dev, "error %d resetting exception endpoint\n", ret);
422
423 ipa_endpoint_modem_pause_all(ipa, false);
424
425 ret = ipa_modem_stop(ipa);
426 if (ret)
427 dev_err(dev, "error %d stopping modem\n", ret);
428
429 /* Now prepare for the next modem boot */
430 ret = ipa_mem_zero_modem(ipa);
431 if (ret)
432 dev_err(dev, "error %d zeroing modem memory regions\n", ret);
433
434 out_power_put:
435 pm_runtime_mark_last_busy(dev);
436 (void)pm_runtime_put_autosuspend(dev);
437 }
438
ipa_modem_notify(struct notifier_block * nb,unsigned long action,void * data)439 static int ipa_modem_notify(struct notifier_block *nb, unsigned long action,
440 void *data)
441 {
442 struct ipa *ipa = container_of(nb, struct ipa, nb);
443 struct qcom_ssr_notify_data *notify_data = data;
444 struct device *dev = ipa->dev;
445
446 switch (action) {
447 case QCOM_SSR_BEFORE_POWERUP:
448 dev_info(dev, "received modem starting event\n");
449 ipa_uc_power(ipa);
450 ipa_smp2p_notify_reset(ipa);
451 break;
452
453 case QCOM_SSR_AFTER_POWERUP:
454 dev_info(dev, "received modem running event\n");
455 break;
456
457 case QCOM_SSR_BEFORE_SHUTDOWN:
458 dev_info(dev, "received modem %s event\n",
459 notify_data->crashed ? "crashed" : "stopping");
460 if (ipa->setup_complete)
461 ipa_modem_crashed(ipa);
462 break;
463
464 case QCOM_SSR_AFTER_SHUTDOWN:
465 dev_info(dev, "received modem offline event\n");
466 break;
467
468 default:
469 dev_err(dev, "received unrecognized event %lu\n", action);
470 break;
471 }
472
473 return NOTIFY_OK;
474 }
475
ipa_modem_config(struct ipa * ipa)476 int ipa_modem_config(struct ipa *ipa)
477 {
478 void *notifier;
479
480 ipa->nb.notifier_call = ipa_modem_notify;
481
482 notifier = qcom_register_ssr_notifier("mpss", &ipa->nb);
483 if (IS_ERR(notifier))
484 return PTR_ERR(notifier);
485
486 ipa->notifier = notifier;
487
488 return 0;
489 }
490
ipa_modem_deconfig(struct ipa * ipa)491 void ipa_modem_deconfig(struct ipa *ipa)
492 {
493 struct device *dev = ipa->dev;
494 int ret;
495
496 ret = qcom_unregister_ssr_notifier(ipa->notifier, &ipa->nb);
497 if (ret)
498 dev_err(dev, "error %d unregistering notifier", ret);
499
500 ipa->notifier = NULL;
501 memset(&ipa->nb, 0, sizeof(ipa->nb));
502 }
503