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
27enum 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 */
35struct ipa_priv {
36	struct ipa *ipa;
37};
38
39/** ipa_open() - Opens the modem network interface */
40static 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
57err_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. */
64static 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 */
85static 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
113err_drop_skb:
114	dev_kfree_skb_any(skb);
115	stats->tx_dropped++;
116
117	return NETDEV_TX_OK;
118}
119
120void 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
136static 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 */
143static 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 */
167void 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 */
183void 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
194int 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	SET_NETDEV_DEV(netdev, &ipa->pdev->dev);
220	priv = netdev_priv(netdev);
221	priv->ipa = ipa;
222
223	ret = register_netdev(netdev);
224	if (ret)
225		free_netdev(netdev);
226	else
227		ipa->modem_netdev = netdev;
228
229out_set_state:
230	if (ret)
231		atomic_set(&ipa->modem_state, IPA_MODEM_STATE_STOPPED);
232	else
233		atomic_set(&ipa->modem_state, IPA_MODEM_STATE_RUNNING);
234	smp_mb__after_atomic();
235
236	return ret;
237}
238
239int ipa_modem_stop(struct ipa *ipa)
240{
241	struct net_device *netdev = ipa->modem_netdev;
242	enum ipa_modem_state state;
243	int ret;
244
245	/* Only attempt to stop the modem if it's running */
246	state = atomic_cmpxchg(&ipa->modem_state, IPA_MODEM_STATE_RUNNING,
247			       IPA_MODEM_STATE_STOPPING);
248
249	/* Silently ignore attempts when already stopped */
250	if (state == IPA_MODEM_STATE_STOPPED)
251		return 0;
252
253	/* If we're somewhere between stopped and starting, we're busy */
254	if (state != IPA_MODEM_STATE_RUNNING)
255		return -EBUSY;
256
257	/* Prevent the modem from triggering a call to ipa_setup() */
258	ipa_smp2p_disable(ipa);
259
260	if (netdev) {
261		/* Stop the queue and disable the endpoints if it's open */
262		ret = ipa_stop(netdev);
263		if (ret)
264			goto out_set_state;
265
266		ipa->modem_netdev = NULL;
267		unregister_netdev(netdev);
268		free_netdev(netdev);
269	} else {
270		ret = 0;
271	}
272
273out_set_state:
274	if (ret)
275		atomic_set(&ipa->modem_state, IPA_MODEM_STATE_RUNNING);
276	else
277		atomic_set(&ipa->modem_state, IPA_MODEM_STATE_STOPPED);
278	smp_mb__after_atomic();
279
280	return ret;
281}
282
283/* Treat a "clean" modem stop the same as a crash */
284static void ipa_modem_crashed(struct ipa *ipa)
285{
286	struct device *dev = &ipa->pdev->dev;
287	int ret;
288
289	ipa_endpoint_modem_pause_all(ipa, true);
290
291	ipa_endpoint_modem_hol_block_clear_all(ipa);
292
293	ipa_table_reset(ipa, true);
294
295	ret = ipa_table_hash_flush(ipa);
296	if (ret)
297		dev_err(dev, "error %d flushing hash caches\n", ret);
298
299	ret = ipa_endpoint_modem_exception_reset_all(ipa);
300	if (ret)
301		dev_err(dev, "error %d resetting exception endpoint\n", ret);
302
303	ipa_endpoint_modem_pause_all(ipa, false);
304
305	ret = ipa_modem_stop(ipa);
306	if (ret)
307		dev_err(dev, "error %d stopping modem\n", ret);
308
309	/* Now prepare for the next modem boot */
310	ret = ipa_mem_zero_modem(ipa);
311	if (ret)
312		dev_err(dev, "error %d zeroing modem memory regions\n", ret);
313}
314
315static int ipa_modem_notify(struct notifier_block *nb, unsigned long action,
316			    void *data)
317{
318	struct ipa *ipa = container_of(nb, struct ipa, nb);
319	struct qcom_ssr_notify_data *notify_data = data;
320	struct device *dev = &ipa->pdev->dev;
321
322	switch (action) {
323	case QCOM_SSR_BEFORE_POWERUP:
324		dev_info(dev, "received modem starting event\n");
325		ipa_smp2p_notify_reset(ipa);
326		break;
327
328	case QCOM_SSR_AFTER_POWERUP:
329		dev_info(dev, "received modem running event\n");
330		break;
331
332	case QCOM_SSR_BEFORE_SHUTDOWN:
333		dev_info(dev, "received modem %s event\n",
334			 notify_data->crashed ? "crashed" : "stopping");
335		if (ipa->setup_complete)
336			ipa_modem_crashed(ipa);
337		break;
338
339	case QCOM_SSR_AFTER_SHUTDOWN:
340		dev_info(dev, "received modem offline event\n");
341		break;
342
343	default:
344		dev_err(dev, "received unrecognized event %lu\n", action);
345		break;
346	}
347
348	return NOTIFY_OK;
349}
350
351int ipa_modem_init(struct ipa *ipa, bool modem_init)
352{
353	return ipa_smp2p_init(ipa, modem_init);
354}
355
356void ipa_modem_exit(struct ipa *ipa)
357{
358	ipa_smp2p_exit(ipa);
359}
360
361int ipa_modem_config(struct ipa *ipa)
362{
363	void *notifier;
364
365	ipa->nb.notifier_call = ipa_modem_notify;
366
367	notifier = qcom_register_ssr_notifier("mpss", &ipa->nb);
368	if (IS_ERR(notifier))
369		return PTR_ERR(notifier);
370
371	ipa->notifier = notifier;
372
373	return 0;
374}
375
376void ipa_modem_deconfig(struct ipa *ipa)
377{
378	struct device *dev = &ipa->pdev->dev;
379	int ret;
380
381	ret = qcom_unregister_ssr_notifier(ipa->notifier, &ipa->nb);
382	if (ret)
383		dev_err(dev, "error %d unregistering notifier", ret);
384
385	ipa->notifier = NULL;
386	memset(&ipa->nb, 0, sizeof(ipa->nb));
387}
388
389int ipa_modem_setup(struct ipa *ipa)
390{
391	return ipa_qmi_setup(ipa);
392}
393
394void ipa_modem_teardown(struct ipa *ipa)
395{
396	ipa_qmi_teardown(ipa);
397}
398