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
32enum 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 * @tx: Transmit endpoint pointer
43 * @rx: Receive endpoint pointer
44 * @work: Work structure used to wake the modem netdev TX queue
45 */
46struct ipa_priv {
47 struct ipa *ipa;
48 struct ipa_endpoint *tx;
49 struct ipa_endpoint *rx;
50 struct work_struct work;
51};
52
53/** ipa_open() - Opens the modem network interface */
54static int ipa_open(struct net_device *netdev)
55{
56 struct ipa_priv *priv = netdev_priv(dev: netdev);
57 struct ipa *ipa = priv->ipa;
58 struct device *dev;
59 int ret;
60
61 dev = ipa->dev;
62 ret = pm_runtime_get_sync(dev);
63 if (ret < 0)
64 goto err_power_put;
65
66 ret = ipa_endpoint_enable_one(endpoint: priv->tx);
67 if (ret)
68 goto err_power_put;
69
70 ret = ipa_endpoint_enable_one(endpoint: priv->rx);
71 if (ret)
72 goto err_disable_tx;
73
74 netif_start_queue(dev: netdev);
75
76 pm_runtime_mark_last_busy(dev);
77 (void)pm_runtime_put_autosuspend(dev);
78
79 return 0;
80
81err_disable_tx:
82 ipa_endpoint_disable_one(endpoint: priv->tx);
83err_power_put:
84 pm_runtime_put_noidle(dev);
85
86 return ret;
87}
88
89/** ipa_stop() - Stops the modem network interface. */
90static int ipa_stop(struct net_device *netdev)
91{
92 struct ipa_priv *priv = netdev_priv(dev: netdev);
93 struct ipa *ipa = priv->ipa;
94 struct device *dev;
95 int ret;
96
97 dev = ipa->dev;
98 ret = pm_runtime_get_sync(dev);
99 if (ret < 0)
100 goto out_power_put;
101
102 netif_stop_queue(dev: netdev);
103
104 ipa_endpoint_disable_one(endpoint: priv->rx);
105 ipa_endpoint_disable_one(endpoint: priv->tx);
106out_power_put:
107 pm_runtime_mark_last_busy(dev);
108 (void)pm_runtime_put_autosuspend(dev);
109
110 return 0;
111}
112
113/** ipa_start_xmit() - Transmit an skb
114 * @skb: Socket buffer to be transmitted
115 * @netdev: Network device
116 *
117 * Return: NETDEV_TX_OK if successful (or dropped), NETDEV_TX_BUSY otherwise
118
119 * Normally NETDEV_TX_OK indicates the buffer was successfully transmitted.
120 * If the buffer has an unexpected protocol or its size is out of range it
121 * is quietly dropped, returning NETDEV_TX_OK. NETDEV_TX_BUSY indicates
122 * the buffer cannot be sent at this time and should retried later.
123 */
124static netdev_tx_t
125ipa_start_xmit(struct sk_buff *skb, struct net_device *netdev)
126{
127 struct net_device_stats *stats = &netdev->stats;
128 struct ipa_priv *priv = netdev_priv(dev: netdev);
129 struct ipa_endpoint *endpoint;
130 struct ipa *ipa = priv->ipa;
131 u32 skb_len = skb->len;
132 struct device *dev;
133 int ret;
134
135 if (!skb_len)
136 goto err_drop_skb;
137
138 endpoint = ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX];
139 if (endpoint->config.qmap && skb->protocol != htons(ETH_P_MAP))
140 goto err_drop_skb;
141
142 /* The hardware must be powered for us to transmit, so if we're not
143 * ready we want the network stack to stop queueing until power is
144 * ACTIVE. Once runtime resume has completed, we inform the network
145 * stack it's OK to try transmitting again.
146 *
147 * We learn from pm_runtime_get() whether the hardware is powered.
148 * If it was not, powering up is either started or already underway.
149 * And in that case we want to disable queueing, expecting it to be
150 * re-enabled once power is ACTIVE. But runtime PM and network
151 * transmit run concurrently, and if we're not careful the requests
152 * to stop and start queueing could occur in the wrong order.
153 *
154 * For that reason we *always* stop queueing here, *before* the call
155 * to pm_runtime_get(). If we determine here that power is ACTIVE,
156 * we restart queueing before transmitting the SKB. Otherwise
157 * queueing will eventually be enabled after resume completes.
158 */
159 netif_stop_queue(dev: netdev);
160
161 dev = ipa->dev;
162 ret = pm_runtime_get(dev);
163 if (ret < 1) {
164 /* If a resume won't happen, just drop the packet */
165 if (ret < 0 && ret != -EINPROGRESS) {
166 netif_wake_queue(dev: netdev);
167 pm_runtime_put_noidle(dev);
168 goto err_drop_skb;
169 }
170
171 pm_runtime_put_noidle(dev);
172
173 return NETDEV_TX_BUSY;
174 }
175
176 netif_wake_queue(dev: netdev);
177
178 ret = ipa_endpoint_skb_tx(endpoint, skb);
179
180 pm_runtime_mark_last_busy(dev);
181 (void)pm_runtime_put_autosuspend(dev);
182
183 if (ret) {
184 if (ret != -E2BIG)
185 return NETDEV_TX_BUSY;
186 goto err_drop_skb;
187 }
188
189 stats->tx_packets++;
190 stats->tx_bytes += skb_len;
191
192 return NETDEV_TX_OK;
193
194err_drop_skb:
195 dev_kfree_skb_any(skb);
196 stats->tx_dropped++;
197
198 return NETDEV_TX_OK;
199}
200
201void ipa_modem_skb_rx(struct net_device *netdev, struct sk_buff *skb)
202{
203 struct net_device_stats *stats = &netdev->stats;
204
205 if (skb) {
206 skb->dev = netdev;
207 skb->protocol = htons(ETH_P_MAP);
208 stats->rx_packets++;
209 stats->rx_bytes += skb->len;
210
211 (void)netif_receive_skb(skb);
212 } else {
213 stats->rx_dropped++;
214 }
215}
216
217static const struct net_device_ops ipa_modem_ops = {
218 .ndo_open = ipa_open,
219 .ndo_stop = ipa_stop,
220 .ndo_start_xmit = ipa_start_xmit,
221};
222
223/** ipa_modem_netdev_setup() - netdev setup function for the modem */
224static void ipa_modem_netdev_setup(struct net_device *netdev)
225{
226 netdev->netdev_ops = &ipa_modem_ops;
227
228 netdev->header_ops = NULL;
229 netdev->type = ARPHRD_RAWIP;
230 netdev->hard_header_len = 0;
231 netdev->min_header_len = ETH_HLEN;
232 netdev->min_mtu = ETH_MIN_MTU;
233 netdev->max_mtu = IPA_MTU;
234 netdev->mtu = netdev->max_mtu;
235 netdev->addr_len = 0;
236 netdev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
237 netdev->flags &= ~(IFF_BROADCAST | IFF_MULTICAST);
238 netdev->priv_flags |= IFF_TX_SKB_SHARING;
239 eth_broadcast_addr(addr: netdev->broadcast);
240
241 /* The endpoint is configured for QMAP */
242 netdev->needed_headroom = sizeof(struct rmnet_map_header);
243 netdev->needed_tailroom = IPA_NETDEV_TAILROOM;
244 netdev->watchdog_timeo = IPA_NETDEV_TIMEOUT * HZ;
245 netdev->hw_features = NETIF_F_SG;
246}
247
248/** ipa_modem_suspend() - suspend callback
249 * @netdev: Network device
250 *
251 * Suspend the modem's endpoints.
252 */
253void ipa_modem_suspend(struct net_device *netdev)
254{
255 struct ipa_priv *priv;
256
257 if (!(netdev->flags & IFF_UP))
258 return;
259
260 priv = netdev_priv(dev: netdev);
261 ipa_endpoint_suspend_one(endpoint: priv->rx);
262 ipa_endpoint_suspend_one(endpoint: priv->tx);
263}
264
265/**
266 * ipa_modem_wake_queue_work() - enable modem netdev queue
267 * @work: Work structure
268 *
269 * Re-enable transmit on the modem network device. This is called
270 * in (power management) work queue context, scheduled when resuming
271 * the modem. We can't enable the queue directly in ipa_modem_resume()
272 * because transmits restart the instant the queue is awakened; but the
273 * device power state won't be ACTIVE until *after* ipa_modem_resume()
274 * returns.
275 */
276static void ipa_modem_wake_queue_work(struct work_struct *work)
277{
278 struct ipa_priv *priv = container_of(work, struct ipa_priv, work);
279
280 netif_wake_queue(dev: priv->tx->netdev);
281}
282
283/** ipa_modem_resume() - resume callback for runtime_pm
284 * @dev: pointer to device
285 *
286 * Resume the modem's endpoints.
287 */
288void ipa_modem_resume(struct net_device *netdev)
289{
290 struct ipa_priv *priv;
291
292 if (!(netdev->flags & IFF_UP))
293 return;
294
295 priv = netdev_priv(dev: netdev);
296 ipa_endpoint_resume_one(endpoint: priv->tx);
297 ipa_endpoint_resume_one(endpoint: priv->rx);
298
299 /* Arrange for the TX queue to be restarted */
300 (void)queue_pm_work(work: &priv->work);
301}
302
303int ipa_modem_start(struct ipa *ipa)
304{
305 enum ipa_modem_state state;
306 struct net_device *netdev;
307 struct ipa_priv *priv;
308 int ret;
309
310 /* Only attempt to start the modem if it's stopped */
311 state = atomic_cmpxchg(v: &ipa->modem_state, old: IPA_MODEM_STATE_STOPPED,
312 new: IPA_MODEM_STATE_STARTING);
313
314 /* Silently ignore attempts when running, or when changing state */
315 if (state != IPA_MODEM_STATE_STOPPED)
316 return 0;
317
318 netdev = alloc_netdev(sizeof(struct ipa_priv), IPA_NETDEV_NAME,
319 NET_NAME_UNKNOWN, ipa_modem_netdev_setup);
320 if (!netdev) {
321 ret = -ENOMEM;
322 goto out_set_state;
323 }
324
325 SET_NETDEV_DEV(netdev, ipa->dev);
326 priv = netdev_priv(dev: netdev);
327 priv->ipa = ipa;
328 priv->tx = ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX];
329 priv->rx = ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX];
330 INIT_WORK(&priv->work, ipa_modem_wake_queue_work);
331
332 priv->tx->netdev = netdev;
333 priv->rx->netdev = netdev;
334
335 ipa->modem_netdev = netdev;
336
337 ret = register_netdev(dev: netdev);
338 if (ret) {
339 ipa->modem_netdev = NULL;
340 priv->rx->netdev = NULL;
341 priv->tx->netdev = NULL;
342
343 free_netdev(dev: netdev);
344 }
345
346out_set_state:
347 if (ret)
348 atomic_set(v: &ipa->modem_state, i: IPA_MODEM_STATE_STOPPED);
349 else
350 atomic_set(v: &ipa->modem_state, i: IPA_MODEM_STATE_RUNNING);
351 smp_mb__after_atomic();
352
353 return ret;
354}
355
356int ipa_modem_stop(struct ipa *ipa)
357{
358 struct net_device *netdev = ipa->modem_netdev;
359 enum ipa_modem_state state;
360
361 /* Only attempt to stop the modem if it's running */
362 state = atomic_cmpxchg(v: &ipa->modem_state, old: IPA_MODEM_STATE_RUNNING,
363 new: IPA_MODEM_STATE_STOPPING);
364
365 /* Silently ignore attempts when already stopped */
366 if (state == IPA_MODEM_STATE_STOPPED)
367 return 0;
368
369 /* If we're somewhere between stopped and starting, we're busy */
370 if (state != IPA_MODEM_STATE_RUNNING)
371 return -EBUSY;
372
373 /* Clean up the netdev and endpoints if it was started */
374 if (netdev) {
375 struct ipa_priv *priv = netdev_priv(dev: netdev);
376
377 cancel_work_sync(work: &priv->work);
378 /* If it was opened, stop it first */
379 if (netdev->flags & IFF_UP)
380 (void)ipa_stop(netdev);
381 unregister_netdev(dev: netdev);
382
383 ipa->modem_netdev = NULL;
384 priv->rx->netdev = NULL;
385 priv->tx->netdev = NULL;
386
387 free_netdev(dev: netdev);
388 }
389
390 atomic_set(v: &ipa->modem_state, i: IPA_MODEM_STATE_STOPPED);
391 smp_mb__after_atomic();
392
393 return 0;
394}
395
396/* Treat a "clean" modem stop the same as a crash */
397static void ipa_modem_crashed(struct ipa *ipa)
398{
399 struct device *dev = ipa->dev;
400 int ret;
401
402 /* Prevent the modem from triggering a call to ipa_setup() */
403 ipa_smp2p_irq_disable_setup(ipa);
404
405 ret = pm_runtime_get_sync(dev);
406 if (ret < 0) {
407 dev_err(dev, "error %d getting power to handle crash\n", ret);
408 goto out_power_put;
409 }
410
411 ipa_endpoint_modem_pause_all(ipa, enable: true);
412
413 ipa_endpoint_modem_hol_block_clear_all(ipa);
414
415 ipa_table_reset(ipa, modem: true);
416
417 ret = ipa_table_hash_flush(ipa);
418 if (ret)
419 dev_err(dev, "error %d flushing hash caches\n", ret);
420
421 ret = ipa_endpoint_modem_exception_reset_all(ipa);
422 if (ret)
423 dev_err(dev, "error %d resetting exception endpoint\n", ret);
424
425 ipa_endpoint_modem_pause_all(ipa, enable: false);
426
427 ret = ipa_modem_stop(ipa);
428 if (ret)
429 dev_err(dev, "error %d stopping modem\n", ret);
430
431 /* Now prepare for the next modem boot */
432 ret = ipa_mem_zero_modem(ipa);
433 if (ret)
434 dev_err(dev, "error %d zeroing modem memory regions\n", ret);
435
436out_power_put:
437 pm_runtime_mark_last_busy(dev);
438 (void)pm_runtime_put_autosuspend(dev);
439}
440
441static int ipa_modem_notify(struct notifier_block *nb, unsigned long action,
442 void *data)
443{
444 struct ipa *ipa = container_of(nb, struct ipa, nb);
445 struct qcom_ssr_notify_data *notify_data = data;
446 struct device *dev = ipa->dev;
447
448 switch (action) {
449 case QCOM_SSR_BEFORE_POWERUP:
450 dev_info(dev, "received modem starting event\n");
451 ipa_uc_power(ipa);
452 ipa_smp2p_notify_reset(ipa);
453 break;
454
455 case QCOM_SSR_AFTER_POWERUP:
456 dev_info(dev, "received modem running event\n");
457 break;
458
459 case QCOM_SSR_BEFORE_SHUTDOWN:
460 dev_info(dev, "received modem %s event\n",
461 notify_data->crashed ? "crashed" : "stopping");
462 if (ipa->setup_complete)
463 ipa_modem_crashed(ipa);
464 break;
465
466 case QCOM_SSR_AFTER_SHUTDOWN:
467 dev_info(dev, "received modem offline event\n");
468 break;
469
470 default:
471 dev_err(dev, "received unrecognized event %lu\n", action);
472 break;
473 }
474
475 return NOTIFY_OK;
476}
477
478int ipa_modem_config(struct ipa *ipa)
479{
480 void *notifier;
481
482 ipa->nb.notifier_call = ipa_modem_notify;
483
484 notifier = qcom_register_ssr_notifier(name: "mpss", nb: &ipa->nb);
485 if (IS_ERR(ptr: notifier))
486 return PTR_ERR(ptr: notifier);
487
488 ipa->notifier = notifier;
489
490 return 0;
491}
492
493void ipa_modem_deconfig(struct ipa *ipa)
494{
495 struct device *dev = ipa->dev;
496 int ret;
497
498 ret = qcom_unregister_ssr_notifier(notify: ipa->notifier, nb: &ipa->nb);
499 if (ret)
500 dev_err(dev, "error %d unregistering notifier", ret);
501
502 ipa->notifier = NULL;
503 memset(&ipa->nb, 0, sizeof(ipa->nb));
504}
505

source code of linux/drivers/net/ipa/ipa_modem.c