1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2021, MediaTek Inc.
4 * Copyright (c) 2021-2022, Intel Corporation.
5 *
6 * Authors:
7 *  Chandrashekar Devegowda <chandrashekar.devegowda@intel.com>
8 *  Haijun Liu <haijun.liu@mediatek.com>
9 *  Ricardo Martinez <ricardo.martinez@linux.intel.com>
10 *
11 * Contributors:
12 *  Amir Hanania <amir.hanania@intel.com>
13 *  Andy Shevchenko <andriy.shevchenko@linux.intel.com>
14 *  Chiranjeevi Rapolu <chiranjeevi.rapolu@intel.com>
15 *  Eliot Lee <eliot.lee@intel.com>
16 *  Moises Veleta <moises.veleta@intel.com>
17 *  Sreehari Kancharla <sreehari.kancharla@intel.com>
18 */
19
20#include <linux/atomic.h>
21#include <linux/device.h>
22#include <linux/gfp.h>
23#include <linux/if_arp.h>
24#include <linux/if_ether.h>
25#include <linux/ip.h>
26#include <linux/kernel.h>
27#include <linux/list.h>
28#include <linux/netdev_features.h>
29#include <linux/netdevice.h>
30#include <linux/pm_runtime.h>
31#include <linux/skbuff.h>
32#include <linux/types.h>
33#include <linux/wwan.h>
34#include <net/ipv6.h>
35#include <net/pkt_sched.h>
36
37#include "t7xx_hif_dpmaif_rx.h"
38#include "t7xx_hif_dpmaif_tx.h"
39#include "t7xx_netdev.h"
40#include "t7xx_pci.h"
41#include "t7xx_port_proxy.h"
42#include "t7xx_state_monitor.h"
43
44#define IP_MUX_SESSION_DEFAULT	0
45#define SBD_PACKET_TYPE_MASK	GENMASK(7, 4)
46
47static void t7xx_ccmni_enable_napi(struct t7xx_ccmni_ctrl *ctlb)
48{
49	struct dpmaif_ctrl *ctrl;
50	int i, ret;
51
52	ctrl =  ctlb->hif_ctrl;
53
54	if (ctlb->is_napi_en)
55		return;
56
57	for (i = 0; i < RXQ_NUM; i++) {
58		/* The usage count has to be bumped every time before calling
59		 * napi_schedule. It will be decresed in the poll routine,
60		 * right after napi_complete_done is called.
61		 */
62		ret = pm_runtime_resume_and_get(ctrl->dev);
63		if (ret < 0) {
64			dev_err(ctrl->dev, "Failed to resume device: %d\n",
65				ret);
66			return;
67		}
68		napi_enable(ctlb->napi[i]);
69		napi_schedule(ctlb->napi[i]);
70	}
71	ctlb->is_napi_en = true;
72}
73
74static void t7xx_ccmni_disable_napi(struct t7xx_ccmni_ctrl *ctlb)
75{
76	int i;
77
78	if (!ctlb->is_napi_en)
79		return;
80
81	for (i = 0; i < RXQ_NUM; i++) {
82		napi_synchronize(ctlb->napi[i]);
83		napi_disable(ctlb->napi[i]);
84	}
85
86	ctlb->is_napi_en = false;
87}
88
89static int t7xx_ccmni_open(struct net_device *dev)
90{
91	struct t7xx_ccmni *ccmni = wwan_netdev_drvpriv(dev);
92	struct t7xx_ccmni_ctrl *ccmni_ctl = ccmni->ctlb;
93
94	netif_carrier_on(dev);
95	netif_tx_start_all_queues(dev);
96	if (!atomic_fetch_inc(&ccmni_ctl->napi_usr_refcnt))
97		t7xx_ccmni_enable_napi(ccmni_ctl);
98
99	atomic_inc(&ccmni->usage);
100	return 0;
101}
102
103static int t7xx_ccmni_close(struct net_device *dev)
104{
105	struct t7xx_ccmni *ccmni = wwan_netdev_drvpriv(dev);
106	struct t7xx_ccmni_ctrl *ccmni_ctl = ccmni->ctlb;
107
108	atomic_dec(&ccmni->usage);
109	if (atomic_dec_and_test(&ccmni_ctl->napi_usr_refcnt))
110		t7xx_ccmni_disable_napi(ccmni_ctl);
111
112	netif_carrier_off(dev);
113	netif_tx_disable(dev);
114	return 0;
115}
116
117static int t7xx_ccmni_send_packet(struct t7xx_ccmni *ccmni, struct sk_buff *skb,
118				  unsigned int txq_number)
119{
120	struct t7xx_ccmni_ctrl *ctlb = ccmni->ctlb;
121	struct t7xx_skb_cb *skb_cb = T7XX_SKB_CB(skb);
122
123	skb_cb->netif_idx = ccmni->index;
124
125	if (t7xx_dpmaif_tx_send_skb(ctlb->hif_ctrl, txq_number, skb))
126		return NETDEV_TX_BUSY;
127
128	return 0;
129}
130
131static netdev_tx_t t7xx_ccmni_start_xmit(struct sk_buff *skb, struct net_device *dev)
132{
133	struct t7xx_ccmni *ccmni = wwan_netdev_drvpriv(dev);
134	int skb_len = skb->len;
135
136	/* If MTU is changed or there is no headroom, drop the packet */
137	if (skb->len > dev->mtu || skb_headroom(skb) < sizeof(struct ccci_header)) {
138		dev_kfree_skb(skb);
139		dev->stats.tx_dropped++;
140		return NETDEV_TX_OK;
141	}
142
143	if (t7xx_ccmni_send_packet(ccmni, skb, DPMAIF_TX_DEFAULT_QUEUE))
144		return NETDEV_TX_BUSY;
145
146	dev->stats.tx_packets++;
147	dev->stats.tx_bytes += skb_len;
148
149	return NETDEV_TX_OK;
150}
151
152static void t7xx_ccmni_tx_timeout(struct net_device *dev, unsigned int __always_unused txqueue)
153{
154	struct t7xx_ccmni *ccmni = netdev_priv(dev);
155
156	dev->stats.tx_errors++;
157
158	if (atomic_read(&ccmni->usage) > 0)
159		netif_tx_wake_all_queues(dev);
160}
161
162static const struct net_device_ops ccmni_netdev_ops = {
163	.ndo_open	  = t7xx_ccmni_open,
164	.ndo_stop	  = t7xx_ccmni_close,
165	.ndo_start_xmit   = t7xx_ccmni_start_xmit,
166	.ndo_tx_timeout   = t7xx_ccmni_tx_timeout,
167};
168
169static void t7xx_ccmni_start(struct t7xx_ccmni_ctrl *ctlb)
170{
171	struct t7xx_ccmni *ccmni;
172	int i;
173
174	for (i = 0; i < ctlb->nic_dev_num; i++) {
175		ccmni = ctlb->ccmni_inst[i];
176		if (!ccmni)
177			continue;
178
179		if (atomic_read(&ccmni->usage) > 0) {
180			netif_tx_start_all_queues(ccmni->dev);
181			netif_carrier_on(ccmni->dev);
182		}
183	}
184
185	if (atomic_read(&ctlb->napi_usr_refcnt))
186		t7xx_ccmni_enable_napi(ctlb);
187}
188
189static void t7xx_ccmni_pre_stop(struct t7xx_ccmni_ctrl *ctlb)
190{
191	struct t7xx_ccmni *ccmni;
192	int i;
193
194	for (i = 0; i < ctlb->nic_dev_num; i++) {
195		ccmni = ctlb->ccmni_inst[i];
196		if (!ccmni)
197			continue;
198
199		if (atomic_read(&ccmni->usage) > 0)
200			netif_tx_disable(ccmni->dev);
201	}
202}
203
204static void t7xx_ccmni_post_stop(struct t7xx_ccmni_ctrl *ctlb)
205{
206	struct t7xx_ccmni *ccmni;
207	int i;
208
209	if (atomic_read(&ctlb->napi_usr_refcnt))
210		t7xx_ccmni_disable_napi(ctlb);
211
212	for (i = 0; i < ctlb->nic_dev_num; i++) {
213		ccmni = ctlb->ccmni_inst[i];
214		if (!ccmni)
215			continue;
216
217		if (atomic_read(&ccmni->usage) > 0)
218			netif_carrier_off(ccmni->dev);
219	}
220}
221
222static void t7xx_ccmni_wwan_setup(struct net_device *dev)
223{
224	dev->needed_headroom += sizeof(struct ccci_header);
225
226	dev->mtu = ETH_DATA_LEN;
227	dev->max_mtu = CCMNI_MTU_MAX;
228	BUILD_BUG_ON(CCMNI_MTU_MAX > DPMAIF_HW_MTU_SIZE);
229
230	dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
231	dev->watchdog_timeo = CCMNI_NETDEV_WDT_TO;
232
233	dev->flags = IFF_POINTOPOINT | IFF_NOARP;
234
235	dev->features = NETIF_F_VLAN_CHALLENGED;
236
237	dev->features |= NETIF_F_SG;
238	dev->hw_features |= NETIF_F_SG;
239
240	dev->features |= NETIF_F_HW_CSUM;
241	dev->hw_features |= NETIF_F_HW_CSUM;
242
243	dev->features |= NETIF_F_RXCSUM;
244	dev->hw_features |= NETIF_F_RXCSUM;
245
246	dev->features |= NETIF_F_GRO;
247	dev->hw_features |= NETIF_F_GRO;
248
249	dev->needs_free_netdev = true;
250
251	dev->type = ARPHRD_NONE;
252
253	dev->netdev_ops = &ccmni_netdev_ops;
254}
255
256static void t7xx_init_netdev_napi(struct t7xx_ccmni_ctrl *ctlb)
257{
258	int i;
259
260	/* one HW, but shared with multiple net devices,
261	 * so add a dummy device for NAPI.
262	 */
263	init_dummy_netdev(&ctlb->dummy_dev);
264	atomic_set(&ctlb->napi_usr_refcnt, 0);
265	ctlb->is_napi_en = false;
266
267	for (i = 0; i < RXQ_NUM; i++) {
268		ctlb->napi[i] = &ctlb->hif_ctrl->rxq[i].napi;
269		netif_napi_add_weight(&ctlb->dummy_dev, ctlb->napi[i], t7xx_dpmaif_napi_rx_poll,
270				      NIC_NAPI_POLL_BUDGET);
271	}
272}
273
274static void t7xx_uninit_netdev_napi(struct t7xx_ccmni_ctrl *ctlb)
275{
276	int i;
277
278	for (i = 0; i < RXQ_NUM; i++) {
279		netif_napi_del(ctlb->napi[i]);
280		ctlb->napi[i] = NULL;
281	}
282}
283
284static int t7xx_ccmni_wwan_newlink(void *ctxt, struct net_device *dev, u32 if_id,
285				   struct netlink_ext_ack *extack)
286{
287	struct t7xx_ccmni_ctrl *ctlb = ctxt;
288	struct t7xx_ccmni *ccmni;
289	int ret;
290
291	if (if_id >= ARRAY_SIZE(ctlb->ccmni_inst))
292		return -EINVAL;
293
294	ccmni = wwan_netdev_drvpriv(dev);
295	ccmni->index = if_id;
296	ccmni->ctlb = ctlb;
297	ccmni->dev = dev;
298	atomic_set(&ccmni->usage, 0);
299	ctlb->ccmni_inst[if_id] = ccmni;
300
301	ret = register_netdevice(dev);
302	if (ret)
303		return ret;
304
305	netif_device_attach(dev);
306	return 0;
307}
308
309static void t7xx_ccmni_wwan_dellink(void *ctxt, struct net_device *dev, struct list_head *head)
310{
311	struct t7xx_ccmni *ccmni = wwan_netdev_drvpriv(dev);
312	struct t7xx_ccmni_ctrl *ctlb = ctxt;
313	u8 if_id = ccmni->index;
314
315	if (if_id >= ARRAY_SIZE(ctlb->ccmni_inst))
316		return;
317
318	if (WARN_ON(ctlb->ccmni_inst[if_id] != ccmni))
319		return;
320
321	unregister_netdevice(dev);
322}
323
324static const struct wwan_ops ccmni_wwan_ops = {
325	.priv_size = sizeof(struct t7xx_ccmni),
326	.setup     = t7xx_ccmni_wwan_setup,
327	.newlink   = t7xx_ccmni_wwan_newlink,
328	.dellink   = t7xx_ccmni_wwan_dellink,
329};
330
331static int t7xx_ccmni_register_wwan(struct t7xx_ccmni_ctrl *ctlb)
332{
333	struct device *dev = ctlb->hif_ctrl->dev;
334	int ret;
335
336	if (ctlb->wwan_is_registered)
337		return 0;
338
339	/* WWAN core will create a netdev for the default IP MUX channel */
340	ret = wwan_register_ops(dev, &ccmni_wwan_ops, ctlb, IP_MUX_SESSION_DEFAULT);
341	if (ret < 0) {
342		dev_err(dev, "Unable to register WWAN ops, %d\n", ret);
343		return ret;
344	}
345
346	ctlb->wwan_is_registered = true;
347	return 0;
348}
349
350static int t7xx_ccmni_md_state_callback(enum md_state state, void *para)
351{
352	struct t7xx_ccmni_ctrl *ctlb = para;
353	struct device *dev;
354	int ret = 0;
355
356	dev = ctlb->hif_ctrl->dev;
357	ctlb->md_sta = state;
358
359	switch (state) {
360	case MD_STATE_READY:
361		ret = t7xx_ccmni_register_wwan(ctlb);
362		if (!ret)
363			t7xx_ccmni_start(ctlb);
364		break;
365
366	case MD_STATE_EXCEPTION:
367	case MD_STATE_STOPPED:
368		t7xx_ccmni_pre_stop(ctlb);
369
370		ret = t7xx_dpmaif_md_state_callback(ctlb->hif_ctrl, state);
371		if (ret < 0)
372			dev_err(dev, "DPMAIF md state callback err, state=%d\n", state);
373
374		t7xx_ccmni_post_stop(ctlb);
375		break;
376
377	case MD_STATE_WAITING_FOR_HS1:
378	case MD_STATE_WAITING_TO_STOP:
379		ret = t7xx_dpmaif_md_state_callback(ctlb->hif_ctrl, state);
380		if (ret < 0)
381			dev_err(dev, "DPMAIF md state callback err, state=%d\n", state);
382
383		break;
384
385	default:
386		break;
387	}
388
389	return ret;
390}
391
392static void init_md_status_notifier(struct t7xx_pci_dev *t7xx_dev)
393{
394	struct t7xx_ccmni_ctrl	*ctlb = t7xx_dev->ccmni_ctlb;
395	struct t7xx_fsm_notifier *md_status_notifier;
396
397	md_status_notifier = &ctlb->md_status_notify;
398	INIT_LIST_HEAD(&md_status_notifier->entry);
399	md_status_notifier->notifier_fn = t7xx_ccmni_md_state_callback;
400	md_status_notifier->data = ctlb;
401
402	t7xx_fsm_notifier_register(t7xx_dev->md, md_status_notifier);
403}
404
405static void t7xx_ccmni_recv_skb(struct t7xx_ccmni_ctrl *ccmni_ctlb, struct sk_buff *skb,
406				struct napi_struct *napi)
407{
408	struct t7xx_skb_cb *skb_cb;
409	struct net_device *net_dev;
410	struct t7xx_ccmni *ccmni;
411	int pkt_type, skb_len;
412	u8 netif_id;
413
414	skb_cb = T7XX_SKB_CB(skb);
415	netif_id = skb_cb->netif_idx;
416	ccmni = ccmni_ctlb->ccmni_inst[netif_id];
417	if (!ccmni) {
418		dev_kfree_skb(skb);
419		return;
420	}
421
422	net_dev = ccmni->dev;
423	pkt_type = skb_cb->rx_pkt_type;
424	skb->dev = net_dev;
425	if (pkt_type == PKT_TYPE_IP6)
426		skb->protocol = htons(ETH_P_IPV6);
427	else
428		skb->protocol = htons(ETH_P_IP);
429
430	skb_len = skb->len;
431	napi_gro_receive(napi, skb);
432	net_dev->stats.rx_packets++;
433	net_dev->stats.rx_bytes += skb_len;
434}
435
436static void t7xx_ccmni_queue_tx_irq_notify(struct t7xx_ccmni_ctrl *ctlb, int qno)
437{
438	struct t7xx_ccmni *ccmni = ctlb->ccmni_inst[0];
439	struct netdev_queue *net_queue;
440
441	if (netif_running(ccmni->dev) && atomic_read(&ccmni->usage) > 0) {
442		net_queue = netdev_get_tx_queue(ccmni->dev, qno);
443		if (netif_tx_queue_stopped(net_queue))
444			netif_tx_wake_queue(net_queue);
445	}
446}
447
448static void t7xx_ccmni_queue_tx_full_notify(struct t7xx_ccmni_ctrl *ctlb, int qno)
449{
450	struct t7xx_ccmni *ccmni = ctlb->ccmni_inst[0];
451	struct netdev_queue *net_queue;
452
453	if (atomic_read(&ccmni->usage) > 0) {
454		netdev_err(ccmni->dev, "TX queue %d is full\n", qno);
455		net_queue = netdev_get_tx_queue(ccmni->dev, qno);
456		netif_tx_stop_queue(net_queue);
457	}
458}
459
460static void t7xx_ccmni_queue_state_notify(struct t7xx_pci_dev *t7xx_dev,
461					  enum dpmaif_txq_state state, int qno)
462{
463	struct t7xx_ccmni_ctrl *ctlb = t7xx_dev->ccmni_ctlb;
464
465	if (ctlb->md_sta != MD_STATE_READY)
466		return;
467
468	if (!ctlb->ccmni_inst[0]) {
469		dev_warn(&t7xx_dev->pdev->dev, "No netdev registered yet\n");
470		return;
471	}
472
473	if (state == DMPAIF_TXQ_STATE_IRQ)
474		t7xx_ccmni_queue_tx_irq_notify(ctlb, qno);
475	else if (state == DMPAIF_TXQ_STATE_FULL)
476		t7xx_ccmni_queue_tx_full_notify(ctlb, qno);
477}
478
479int t7xx_ccmni_init(struct t7xx_pci_dev *t7xx_dev)
480{
481	struct device *dev = &t7xx_dev->pdev->dev;
482	struct t7xx_ccmni_ctrl *ctlb;
483
484	ctlb = devm_kzalloc(dev, sizeof(*ctlb), GFP_KERNEL);
485	if (!ctlb)
486		return -ENOMEM;
487
488	t7xx_dev->ccmni_ctlb = ctlb;
489	ctlb->t7xx_dev = t7xx_dev;
490	ctlb->callbacks.state_notify = t7xx_ccmni_queue_state_notify;
491	ctlb->callbacks.recv_skb = t7xx_ccmni_recv_skb;
492	ctlb->nic_dev_num = NIC_DEV_DEFAULT;
493
494	ctlb->hif_ctrl = t7xx_dpmaif_hif_init(t7xx_dev, &ctlb->callbacks);
495	if (!ctlb->hif_ctrl)
496		return -ENOMEM;
497
498	t7xx_init_netdev_napi(ctlb);
499	init_md_status_notifier(t7xx_dev);
500	return 0;
501}
502
503void t7xx_ccmni_exit(struct t7xx_pci_dev *t7xx_dev)
504{
505	struct t7xx_ccmni_ctrl *ctlb = t7xx_dev->ccmni_ctlb;
506
507	t7xx_fsm_notifier_unregister(t7xx_dev->md, &ctlb->md_status_notify);
508
509	if (ctlb->wwan_is_registered) {
510		wwan_unregister_ops(&t7xx_dev->pdev->dev);
511		ctlb->wwan_is_registered = false;
512	}
513
514	t7xx_uninit_netdev_napi(ctlb);
515	t7xx_dpmaif_hif_exit(ctlb->hif_ctrl);
516}
517