1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2020-21 Intel Corporation.
4 */
5
6#include "iosm_ipc_mux_codec.h"
7
8/* At the begin of the runtime phase the IP MUX channel shall created. */
9static int ipc_mux_channel_create(struct iosm_mux *ipc_mux)
10{
11	int channel_id;
12
13	channel_id = ipc_imem_channel_alloc(ipc_mux->imem, ipc_mux->instance_id,
14					    IPC_CTYPE_WWAN);
15
16	if (channel_id < 0) {
17		dev_err(ipc_mux->dev,
18			"allocation of the MUX channel id failed");
19		ipc_mux->state = MUX_S_ERROR;
20		ipc_mux->event = MUX_E_NOT_APPLICABLE;
21		goto no_channel;
22	}
23
24	/* Establish the MUX channel in blocking mode. */
25	ipc_mux->channel = ipc_imem_channel_open(ipc_mux->imem, channel_id,
26						 IPC_HP_NET_CHANNEL_INIT);
27
28	if (!ipc_mux->channel) {
29		dev_err(ipc_mux->dev, "ipc_imem_channel_open failed");
30		ipc_mux->state = MUX_S_ERROR;
31		ipc_mux->event = MUX_E_NOT_APPLICABLE;
32		return -ENODEV; /* MUX channel is not available. */
33	}
34
35	/* Define the MUX active state properties. */
36	ipc_mux->state = MUX_S_ACTIVE;
37	ipc_mux->event = MUX_E_NO_ORDERS;
38
39no_channel:
40	return channel_id;
41}
42
43/* Reset the session/if id state. */
44static void ipc_mux_session_free(struct iosm_mux *ipc_mux, int if_id)
45{
46	struct mux_session *if_entry;
47
48	if_entry = &ipc_mux->session[if_id];
49	/* Reset the session state. */
50	if_entry->wwan = NULL;
51}
52
53/* Create and send the session open command. */
54static struct mux_cmd_open_session_resp *
55ipc_mux_session_open_send(struct iosm_mux *ipc_mux, int if_id)
56{
57	struct mux_cmd_open_session_resp *open_session_resp;
58	struct mux_acb *acb = &ipc_mux->acb;
59	union mux_cmd_param param;
60
61	/* open_session commands to one ACB and start transmission. */
62	param.open_session.flow_ctrl = 0;
63	param.open_session.ipv4v6_hints = 0;
64	param.open_session.reserved2 = 0;
65	param.open_session.dl_head_pad_len = cpu_to_le32(IPC_MEM_DL_ETH_OFFSET);
66
67	/* Finish and transfer ACB. The user thread is suspended.
68	 * It is a blocking function call, until CP responds or timeout.
69	 */
70	acb->wanted_response = MUX_CMD_OPEN_SESSION_RESP;
71	if (ipc_mux_dl_acb_send_cmds(ipc_mux, MUX_CMD_OPEN_SESSION, if_id, 0,
72				     &param, sizeof(param.open_session), true,
73				 false) ||
74	    acb->got_response != MUX_CMD_OPEN_SESSION_RESP) {
75		dev_err(ipc_mux->dev, "if_id %d: OPEN_SESSION send failed",
76			if_id);
77		return NULL;
78	}
79
80	open_session_resp = &ipc_mux->acb.got_param.open_session_resp;
81	if (open_session_resp->response != cpu_to_le32(MUX_CMD_RESP_SUCCESS)) {
82		dev_err(ipc_mux->dev,
83			"if_id %d,session open failed,response=%d", if_id,
84			open_session_resp->response);
85		return NULL;
86	}
87
88	return open_session_resp;
89}
90
91/* Open the first IP session. */
92static bool ipc_mux_session_open(struct iosm_mux *ipc_mux,
93				 struct mux_session_open *session_open)
94{
95	struct mux_cmd_open_session_resp *open_session_resp;
96	int if_id;
97
98	/* Search for a free session interface id. */
99	if_id = le32_to_cpu(session_open->if_id);
100	if (if_id < 0 || if_id >= IPC_MEM_MUX_IP_SESSION_ENTRIES) {
101		dev_err(ipc_mux->dev, "invalid interface id=%d", if_id);
102		return false;
103	}
104
105	/* Create and send the session open command.
106	 * It is a blocking function call, until CP responds or timeout.
107	 */
108	open_session_resp = ipc_mux_session_open_send(ipc_mux, if_id);
109	if (!open_session_resp) {
110		ipc_mux_session_free(ipc_mux, if_id);
111		session_open->if_id = cpu_to_le32(-1);
112		return false;
113	}
114
115	/* Initialize the uplink skb accumulator. */
116	skb_queue_head_init(&ipc_mux->session[if_id].ul_list);
117
118	ipc_mux->session[if_id].dl_head_pad_len = IPC_MEM_DL_ETH_OFFSET;
119	ipc_mux->session[if_id].ul_head_pad_len =
120		le32_to_cpu(open_session_resp->ul_head_pad_len);
121	ipc_mux->session[if_id].wwan = ipc_mux->wwan;
122
123	/* Reset the flow ctrl stats of the session */
124	ipc_mux->session[if_id].flow_ctl_en_cnt = 0;
125	ipc_mux->session[if_id].flow_ctl_dis_cnt = 0;
126	ipc_mux->session[if_id].ul_flow_credits = 0;
127	ipc_mux->session[if_id].net_tx_stop = false;
128	ipc_mux->session[if_id].flow_ctl_mask = 0;
129
130	/* Save and return the assigned if id. */
131	session_open->if_id = cpu_to_le32(if_id);
132	ipc_mux->nr_sessions++;
133
134	return true;
135}
136
137/* Free pending session UL packet. */
138static void ipc_mux_session_reset(struct iosm_mux *ipc_mux, int if_id)
139{
140	/* Reset the session/if id state. */
141	ipc_mux_session_free(ipc_mux, if_id);
142
143	/* Empty the uplink skb accumulator. */
144	skb_queue_purge(&ipc_mux->session[if_id].ul_list);
145}
146
147static void ipc_mux_session_close(struct iosm_mux *ipc_mux,
148				  struct mux_session_close *msg)
149{
150	int if_id;
151
152	/* Copy the session interface id. */
153	if_id = le32_to_cpu(msg->if_id);
154
155	if (if_id < 0 || if_id >= IPC_MEM_MUX_IP_SESSION_ENTRIES) {
156		dev_err(ipc_mux->dev, "invalid session id %d", if_id);
157		return;
158	}
159
160	/* Create and send the session close command.
161	 * It is a blocking function call, until CP responds or timeout.
162	 */
163	if (ipc_mux_dl_acb_send_cmds(ipc_mux, MUX_CMD_CLOSE_SESSION, if_id, 0,
164				     NULL, 0, true, false))
165		dev_err(ipc_mux->dev, "if_id %d: CLOSE_SESSION send failed",
166			if_id);
167
168	/* Reset the flow ctrl stats of the session */
169	ipc_mux->session[if_id].flow_ctl_en_cnt = 0;
170	ipc_mux->session[if_id].flow_ctl_dis_cnt = 0;
171	ipc_mux->session[if_id].flow_ctl_mask = 0;
172
173	ipc_mux_session_reset(ipc_mux, if_id);
174	ipc_mux->nr_sessions--;
175}
176
177static void ipc_mux_channel_close(struct iosm_mux *ipc_mux,
178				  struct mux_channel_close *channel_close_p)
179{
180	int i;
181
182	/* Free pending session UL packet. */
183	for (i = 0; i < IPC_MEM_MUX_IP_SESSION_ENTRIES; i++)
184		if (ipc_mux->session[i].wwan)
185			ipc_mux_session_reset(ipc_mux, i);
186
187	ipc_imem_channel_close(ipc_mux->imem, ipc_mux->channel_id);
188
189	/* Reset the MUX object. */
190	ipc_mux->state = MUX_S_INACTIVE;
191	ipc_mux->event = MUX_E_INACTIVE;
192}
193
194/* CP has interrupted AP. If AP is in IP MUX mode, execute the pending ops. */
195static int ipc_mux_schedule(struct iosm_mux *ipc_mux, union mux_msg *msg)
196{
197	enum mux_event order;
198	bool success;
199	int ret = -EIO;
200
201	if (!ipc_mux->initialized) {
202		ret = -EAGAIN;
203		goto out;
204	}
205
206	order = msg->common.event;
207
208	switch (ipc_mux->state) {
209	case MUX_S_INACTIVE:
210		if (order != MUX_E_MUX_SESSION_OPEN)
211			goto out; /* Wait for the request to open a session */
212
213		if (ipc_mux->event == MUX_E_INACTIVE)
214			/* Establish the MUX channel and the new state. */
215			ipc_mux->channel_id = ipc_mux_channel_create(ipc_mux);
216
217		if (ipc_mux->state != MUX_S_ACTIVE) {
218			ret = ipc_mux->channel_id; /* Missing the MUX channel */
219			goto out;
220		}
221
222		/* Disable the TD update timer and open the first IP session. */
223		ipc_imem_td_update_timer_suspend(ipc_mux->imem, true);
224		ipc_mux->event = MUX_E_MUX_SESSION_OPEN;
225		success = ipc_mux_session_open(ipc_mux, &msg->session_open);
226
227		ipc_imem_td_update_timer_suspend(ipc_mux->imem, false);
228		if (success)
229			ret = ipc_mux->channel_id;
230		goto out;
231
232	case MUX_S_ACTIVE:
233		switch (order) {
234		case MUX_E_MUX_SESSION_OPEN:
235			/* Disable the TD update timer and open a session */
236			ipc_imem_td_update_timer_suspend(ipc_mux->imem, true);
237			ipc_mux->event = MUX_E_MUX_SESSION_OPEN;
238			success = ipc_mux_session_open(ipc_mux,
239						       &msg->session_open);
240			ipc_imem_td_update_timer_suspend(ipc_mux->imem, false);
241			if (success)
242				ret = ipc_mux->channel_id;
243			goto out;
244
245		case MUX_E_MUX_SESSION_CLOSE:
246			/* Release an IP session. */
247			ipc_mux->event = MUX_E_MUX_SESSION_CLOSE;
248			ipc_mux_session_close(ipc_mux, &msg->session_close);
249			if (!ipc_mux->nr_sessions) {
250				ipc_mux->event = MUX_E_MUX_CHANNEL_CLOSE;
251				ipc_mux_channel_close(ipc_mux,
252						      &msg->channel_close);
253			}
254			ret = ipc_mux->channel_id;
255			goto out;
256
257		case MUX_E_MUX_CHANNEL_CLOSE:
258			/* Close the MUX channel pipes. */
259			ipc_mux->event = MUX_E_MUX_CHANNEL_CLOSE;
260			ipc_mux_channel_close(ipc_mux, &msg->channel_close);
261			ret = ipc_mux->channel_id;
262			goto out;
263
264		default:
265			/* Invalid order. */
266			goto out;
267		}
268
269	default:
270		dev_err(ipc_mux->dev,
271			"unexpected MUX transition: state=%d, event=%d",
272			ipc_mux->state, ipc_mux->event);
273	}
274out:
275	return ret;
276}
277
278struct iosm_mux *ipc_mux_init(struct ipc_mux_config *mux_cfg,
279			      struct iosm_imem *imem)
280{
281	struct iosm_mux *ipc_mux = kzalloc(sizeof(*ipc_mux), GFP_KERNEL);
282	int i, j, ul_tds, ul_td_size;
283	struct sk_buff_head *free_list;
284	struct sk_buff *skb;
285	int qlt_size;
286
287	if (!ipc_mux)
288		return NULL;
289
290	ipc_mux->protocol = mux_cfg->protocol;
291	ipc_mux->ul_flow = mux_cfg->ul_flow;
292	ipc_mux->instance_id = mux_cfg->instance_id;
293	ipc_mux->wwan_q_offset = 0;
294
295	ipc_mux->pcie = imem->pcie;
296	ipc_mux->imem = imem;
297	ipc_mux->ipc_protocol = imem->ipc_protocol;
298	ipc_mux->dev = imem->dev;
299	ipc_mux->wwan = imem->wwan;
300
301	/* Get the reference to the UL ADB list. */
302	free_list = &ipc_mux->ul_adb.free_list;
303
304	/* Initialize the list with free ADB. */
305	skb_queue_head_init(free_list);
306
307	ul_td_size = IPC_MEM_MAX_DL_MUX_LITE_BUF_SIZE;
308
309	ul_tds = IPC_MEM_MAX_TDS_MUX_LITE_UL;
310
311	ipc_mux->ul_adb.dest_skb = NULL;
312
313	ipc_mux->initialized = true;
314	ipc_mux->adb_prep_ongoing = false;
315	ipc_mux->size_needed = 0;
316	ipc_mux->ul_data_pend_bytes = 0;
317	ipc_mux->state = MUX_S_INACTIVE;
318	ipc_mux->ev_mux_net_transmit_pending = false;
319	ipc_mux->tx_transaction_id = 0;
320	ipc_mux->rr_next_session = 0;
321	ipc_mux->event = MUX_E_INACTIVE;
322	ipc_mux->channel_id = -1;
323	ipc_mux->channel = NULL;
324
325	if (ipc_mux->protocol != MUX_LITE) {
326		qlt_size = offsetof(struct mux_qlth, ql) +
327				MUX_QUEUE_LEVEL * sizeof(struct mux_qlth_ql);
328
329		for (i = 0; i < IPC_MEM_MUX_IP_SESSION_ENTRIES; i++) {
330			ipc_mux->ul_adb.pp_qlt[i] = kzalloc(qlt_size,
331							    GFP_ATOMIC);
332			if (!ipc_mux->ul_adb.pp_qlt[i]) {
333				for (j = i - 1; j >= 0; j--)
334					kfree(ipc_mux->ul_adb.pp_qlt[j]);
335				kfree(ipc_mux);
336				return NULL;
337			}
338		}
339
340		ul_td_size = IPC_MEM_MAX_UL_ADB_BUF_SIZE;
341		ul_tds = IPC_MEM_MAX_TDS_MUX_AGGR_UL;
342	}
343
344	/* Allocate the list of UL ADB. */
345	for (i = 0; i < ul_tds; i++) {
346		dma_addr_t mapping;
347
348		skb = ipc_pcie_alloc_skb(ipc_mux->pcie, ul_td_size, GFP_ATOMIC,
349					 &mapping, DMA_TO_DEVICE, 0);
350		if (!skb) {
351			ipc_mux_deinit(ipc_mux);
352			return NULL;
353		}
354		/* Extend the UL ADB list. */
355		skb_queue_tail(free_list, skb);
356	}
357
358	return ipc_mux;
359}
360
361/* Informs the network stack to restart transmission for all opened session if
362 * Flow Control is not ON for that session.
363 */
364static void ipc_mux_restart_tx_for_all_sessions(struct iosm_mux *ipc_mux)
365{
366	struct mux_session *session;
367	int idx;
368
369	for (idx = 0; idx < IPC_MEM_MUX_IP_SESSION_ENTRIES; idx++) {
370		session = &ipc_mux->session[idx];
371
372		if (!session->wwan)
373			continue;
374
375		/* If flow control of the session is OFF and if there was tx
376		 * stop then restart. Inform the network interface to restart
377		 * sending data.
378		 */
379		if (session->flow_ctl_mask == 0) {
380			session->net_tx_stop = false;
381			ipc_mux_netif_tx_flowctrl(session, idx, false);
382		}
383	}
384}
385
386/* Informs the network stack to stop sending further pkt for all opened
387 * sessions
388 */
389static void ipc_mux_stop_netif_for_all_sessions(struct iosm_mux *ipc_mux)
390{
391	struct mux_session *session;
392	int idx;
393
394	for (idx = 0; idx < IPC_MEM_MUX_IP_SESSION_ENTRIES; idx++) {
395		session = &ipc_mux->session[idx];
396
397		if (!session->wwan)
398			continue;
399
400		ipc_mux_netif_tx_flowctrl(session, session->if_id, true);
401	}
402}
403
404void ipc_mux_check_n_restart_tx(struct iosm_mux *ipc_mux)
405{
406	if (ipc_mux->ul_flow == MUX_UL) {
407		int low_thresh = IPC_MEM_MUX_UL_FLOWCTRL_LOW_B;
408
409		if (ipc_mux->ul_data_pend_bytes < low_thresh)
410			ipc_mux_restart_tx_for_all_sessions(ipc_mux);
411	}
412}
413
414int ipc_mux_get_max_sessions(struct iosm_mux *ipc_mux)
415{
416	return ipc_mux ? IPC_MEM_MUX_IP_SESSION_ENTRIES : -EFAULT;
417}
418
419enum ipc_mux_protocol ipc_mux_get_active_protocol(struct iosm_mux *ipc_mux)
420{
421	return ipc_mux ? ipc_mux->protocol : MUX_UNKNOWN;
422}
423
424int ipc_mux_open_session(struct iosm_mux *ipc_mux, int session_nr)
425{
426	struct mux_session_open *session_open;
427	union mux_msg mux_msg;
428
429	session_open = &mux_msg.session_open;
430	session_open->event = MUX_E_MUX_SESSION_OPEN;
431
432	session_open->if_id = cpu_to_le32(session_nr);
433	ipc_mux->session[session_nr].flags |= IPC_MEM_WWAN_MUX;
434	return ipc_mux_schedule(ipc_mux, &mux_msg);
435}
436
437int ipc_mux_close_session(struct iosm_mux *ipc_mux, int session_nr)
438{
439	struct mux_session_close *session_close;
440	union mux_msg mux_msg;
441	int ret_val;
442
443	session_close = &mux_msg.session_close;
444	session_close->event = MUX_E_MUX_SESSION_CLOSE;
445
446	session_close->if_id = cpu_to_le32(session_nr);
447	ret_val = ipc_mux_schedule(ipc_mux, &mux_msg);
448	ipc_mux->session[session_nr].flags &= ~IPC_MEM_WWAN_MUX;
449
450	return ret_val;
451}
452
453void ipc_mux_deinit(struct iosm_mux *ipc_mux)
454{
455	struct mux_channel_close *channel_close;
456	struct sk_buff_head *free_list;
457	union mux_msg mux_msg;
458	struct sk_buff *skb;
459
460	if (!ipc_mux->initialized)
461		return;
462	ipc_mux_stop_netif_for_all_sessions(ipc_mux);
463
464	if (ipc_mux->state == MUX_S_ACTIVE) {
465		channel_close = &mux_msg.channel_close;
466		channel_close->event = MUX_E_MUX_CHANNEL_CLOSE;
467		ipc_mux_schedule(ipc_mux, &mux_msg);
468	}
469
470	/* Empty the ADB free list. */
471	free_list = &ipc_mux->ul_adb.free_list;
472
473	/* Remove from the head of the downlink queue. */
474	while ((skb = skb_dequeue(free_list)))
475		ipc_pcie_kfree_skb(ipc_mux->pcie, skb);
476
477	if (ipc_mux->channel) {
478		ipc_mux->channel->ul_pipe.is_open = false;
479		ipc_mux->channel->dl_pipe.is_open = false;
480	}
481
482	kfree(ipc_mux);
483}
484