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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) ST-Ericsson AB 2010
4  * Author:  Daniel Martensson
5  *	    Dmitry.Tarnyagin  / dmitry.tarnyagin@lockless.no
6  */
7 
8 #define pr_fmt(fmt) KBUILD_MODNAME fmt
9 
10 #include <linux/init.h>
11 #include <linux/module.h>
12 #include <linux/device.h>
13 #include <linux/netdevice.h>
14 #include <linux/string.h>
15 #include <linux/list.h>
16 #include <linux/interrupt.h>
17 #include <linux/delay.h>
18 #include <linux/sched.h>
19 #include <linux/if_arp.h>
20 #include <linux/timer.h>
21 #include <net/rtnetlink.h>
22 #include <linux/pkt_sched.h>
23 #include <net/caif/caif_layer.h>
24 #include <net/caif/caif_hsi.h>
25 
26 MODULE_LICENSE("GPL");
27 MODULE_AUTHOR("Daniel Martensson");
28 MODULE_DESCRIPTION("CAIF HSI driver");
29 
30 /* Returns the number of padding bytes for alignment. */
31 #define PAD_POW2(x, pow) ((((x)&((pow)-1)) == 0) ? 0 :\
32 				(((pow)-((x)&((pow)-1)))))
33 
34 static const struct cfhsi_config  hsi_default_config = {
35 
36 	/* Inactivity timeout on HSI, ms */
37 	.inactivity_timeout = HZ,
38 
39 	/* Aggregation timeout (ms) of zero means no aggregation is done*/
40 	.aggregation_timeout = 1,
41 
42 	/*
43 	 * HSI link layer flow-control thresholds.
44 	 * Threshold values for the HSI packet queue. Flow-control will be
45 	 * asserted when the number of packets exceeds q_high_mark. It will
46 	 * not be de-asserted before the number of packets drops below
47 	 * q_low_mark.
48 	 * Warning: A high threshold value might increase throughput but it
49 	 * will at the same time prevent channel prioritization and increase
50 	 * the risk of flooding the modem. The high threshold should be above
51 	 * the low.
52 	 */
53 	.q_high_mark = 100,
54 	.q_low_mark = 50,
55 
56 	/*
57 	 * HSI padding options.
58 	 * Warning: must be a base of 2 (& operation used) and can not be zero !
59 	 */
60 	.head_align = 4,
61 	.tail_align = 4,
62 };
63 
64 #define ON 1
65 #define OFF 0
66 
67 static LIST_HEAD(cfhsi_list);
68 
cfhsi_inactivity_tout(struct timer_list * t)69 static void cfhsi_inactivity_tout(struct timer_list *t)
70 {
71 	struct cfhsi *cfhsi = from_timer(cfhsi, t, inactivity_timer);
72 
73 	netdev_dbg(cfhsi->ndev, "%s.\n",
74 		__func__);
75 
76 	/* Schedule power down work queue. */
77 	if (!test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
78 		queue_work(cfhsi->wq, &cfhsi->wake_down_work);
79 }
80 
cfhsi_update_aggregation_stats(struct cfhsi * cfhsi,const struct sk_buff * skb,int direction)81 static void cfhsi_update_aggregation_stats(struct cfhsi *cfhsi,
82 					   const struct sk_buff *skb,
83 					   int direction)
84 {
85 	struct caif_payload_info *info;
86 	int hpad, tpad, len;
87 
88 	info = (struct caif_payload_info *)&skb->cb;
89 	hpad = 1 + PAD_POW2((info->hdr_len + 1), cfhsi->cfg.head_align);
90 	tpad = PAD_POW2((skb->len + hpad), cfhsi->cfg.tail_align);
91 	len = skb->len + hpad + tpad;
92 
93 	if (direction > 0)
94 		cfhsi->aggregation_len += len;
95 	else if (direction < 0)
96 		cfhsi->aggregation_len -= len;
97 }
98 
cfhsi_can_send_aggregate(struct cfhsi * cfhsi)99 static bool cfhsi_can_send_aggregate(struct cfhsi *cfhsi)
100 {
101 	int i;
102 
103 	if (cfhsi->cfg.aggregation_timeout == 0)
104 		return true;
105 
106 	for (i = 0; i < CFHSI_PRIO_BEBK; ++i) {
107 		if (cfhsi->qhead[i].qlen)
108 			return true;
109 	}
110 
111 	/* TODO: Use aggregation_len instead */
112 	if (cfhsi->qhead[CFHSI_PRIO_BEBK].qlen >= CFHSI_MAX_PKTS)
113 		return true;
114 
115 	return false;
116 }
117 
cfhsi_dequeue(struct cfhsi * cfhsi)118 static struct sk_buff *cfhsi_dequeue(struct cfhsi *cfhsi)
119 {
120 	struct sk_buff *skb;
121 	int i;
122 
123 	for (i = 0; i < CFHSI_PRIO_LAST; ++i) {
124 		skb = skb_dequeue(&cfhsi->qhead[i]);
125 		if (skb)
126 			break;
127 	}
128 
129 	return skb;
130 }
131 
cfhsi_tx_queue_len(struct cfhsi * cfhsi)132 static int cfhsi_tx_queue_len(struct cfhsi *cfhsi)
133 {
134 	int i, len = 0;
135 	for (i = 0; i < CFHSI_PRIO_LAST; ++i)
136 		len += skb_queue_len(&cfhsi->qhead[i]);
137 	return len;
138 }
139 
cfhsi_abort_tx(struct cfhsi * cfhsi)140 static void cfhsi_abort_tx(struct cfhsi *cfhsi)
141 {
142 	struct sk_buff *skb;
143 
144 	for (;;) {
145 		spin_lock_bh(&cfhsi->lock);
146 		skb = cfhsi_dequeue(cfhsi);
147 		if (!skb)
148 			break;
149 
150 		cfhsi->ndev->stats.tx_errors++;
151 		cfhsi->ndev->stats.tx_dropped++;
152 		cfhsi_update_aggregation_stats(cfhsi, skb, -1);
153 		spin_unlock_bh(&cfhsi->lock);
154 		kfree_skb(skb);
155 	}
156 	cfhsi->tx_state = CFHSI_TX_STATE_IDLE;
157 	if (!test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
158 		mod_timer(&cfhsi->inactivity_timer,
159 			jiffies + cfhsi->cfg.inactivity_timeout);
160 	spin_unlock_bh(&cfhsi->lock);
161 }
162 
cfhsi_flush_fifo(struct cfhsi * cfhsi)163 static int cfhsi_flush_fifo(struct cfhsi *cfhsi)
164 {
165 	char buffer[32]; /* Any reasonable value */
166 	size_t fifo_occupancy;
167 	int ret;
168 
169 	netdev_dbg(cfhsi->ndev, "%s.\n",
170 		__func__);
171 
172 	do {
173 		ret = cfhsi->ops->cfhsi_fifo_occupancy(cfhsi->ops,
174 				&fifo_occupancy);
175 		if (ret) {
176 			netdev_warn(cfhsi->ndev,
177 				"%s: can't get FIFO occupancy: %d.\n",
178 				__func__, ret);
179 			break;
180 		} else if (!fifo_occupancy)
181 			/* No more data, exitting normally */
182 			break;
183 
184 		fifo_occupancy = min(sizeof(buffer), fifo_occupancy);
185 		set_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits);
186 		ret = cfhsi->ops->cfhsi_rx(buffer, fifo_occupancy,
187 				cfhsi->ops);
188 		if (ret) {
189 			clear_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits);
190 			netdev_warn(cfhsi->ndev,
191 				"%s: can't read data: %d.\n",
192 				__func__, ret);
193 			break;
194 		}
195 
196 		ret = 5 * HZ;
197 		ret = wait_event_interruptible_timeout(cfhsi->flush_fifo_wait,
198 			 !test_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits), ret);
199 
200 		if (ret < 0) {
201 			netdev_warn(cfhsi->ndev,
202 				"%s: can't wait for flush complete: %d.\n",
203 				__func__, ret);
204 			break;
205 		} else if (!ret) {
206 			ret = -ETIMEDOUT;
207 			netdev_warn(cfhsi->ndev,
208 				"%s: timeout waiting for flush complete.\n",
209 				__func__);
210 			break;
211 		}
212 	} while (1);
213 
214 	return ret;
215 }
216 
cfhsi_tx_frm(struct cfhsi_desc * desc,struct cfhsi * cfhsi)217 static int cfhsi_tx_frm(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
218 {
219 	int nfrms = 0;
220 	int pld_len = 0;
221 	struct sk_buff *skb;
222 	u8 *pfrm = desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ;
223 
224 	skb = cfhsi_dequeue(cfhsi);
225 	if (!skb)
226 		return 0;
227 
228 	/* Clear offset. */
229 	desc->offset = 0;
230 
231 	/* Check if we can embed a CAIF frame. */
232 	if (skb->len < CFHSI_MAX_EMB_FRM_SZ) {
233 		struct caif_payload_info *info;
234 		int hpad;
235 		int tpad;
236 
237 		/* Calculate needed head alignment and tail alignment. */
238 		info = (struct caif_payload_info *)&skb->cb;
239 
240 		hpad = 1 + PAD_POW2((info->hdr_len + 1), cfhsi->cfg.head_align);
241 		tpad = PAD_POW2((skb->len + hpad), cfhsi->cfg.tail_align);
242 
243 		/* Check if frame still fits with added alignment. */
244 		if ((skb->len + hpad + tpad) <= CFHSI_MAX_EMB_FRM_SZ) {
245 			u8 *pemb = desc->emb_frm;
246 			desc->offset = CFHSI_DESC_SHORT_SZ;
247 			*pemb = (u8)(hpad - 1);
248 			pemb += hpad;
249 
250 			/* Update network statistics. */
251 			spin_lock_bh(&cfhsi->lock);
252 			cfhsi->ndev->stats.tx_packets++;
253 			cfhsi->ndev->stats.tx_bytes += skb->len;
254 			cfhsi_update_aggregation_stats(cfhsi, skb, -1);
255 			spin_unlock_bh(&cfhsi->lock);
256 
257 			/* Copy in embedded CAIF frame. */
258 			skb_copy_bits(skb, 0, pemb, skb->len);
259 
260 			/* Consume the SKB */
261 			consume_skb(skb);
262 			skb = NULL;
263 		}
264 	}
265 
266 	/* Create payload CAIF frames. */
267 	while (nfrms < CFHSI_MAX_PKTS) {
268 		struct caif_payload_info *info;
269 		int hpad;
270 		int tpad;
271 
272 		if (!skb)
273 			skb = cfhsi_dequeue(cfhsi);
274 
275 		if (!skb)
276 			break;
277 
278 		/* Calculate needed head alignment and tail alignment. */
279 		info = (struct caif_payload_info *)&skb->cb;
280 
281 		hpad = 1 + PAD_POW2((info->hdr_len + 1), cfhsi->cfg.head_align);
282 		tpad = PAD_POW2((skb->len + hpad), cfhsi->cfg.tail_align);
283 
284 		/* Fill in CAIF frame length in descriptor. */
285 		desc->cffrm_len[nfrms] = hpad + skb->len + tpad;
286 
287 		/* Fill head padding information. */
288 		*pfrm = (u8)(hpad - 1);
289 		pfrm += hpad;
290 
291 		/* Update network statistics. */
292 		spin_lock_bh(&cfhsi->lock);
293 		cfhsi->ndev->stats.tx_packets++;
294 		cfhsi->ndev->stats.tx_bytes += skb->len;
295 		cfhsi_update_aggregation_stats(cfhsi, skb, -1);
296 		spin_unlock_bh(&cfhsi->lock);
297 
298 		/* Copy in CAIF frame. */
299 		skb_copy_bits(skb, 0, pfrm, skb->len);
300 
301 		/* Update payload length. */
302 		pld_len += desc->cffrm_len[nfrms];
303 
304 		/* Update frame pointer. */
305 		pfrm += skb->len + tpad;
306 
307 		/* Consume the SKB */
308 		consume_skb(skb);
309 		skb = NULL;
310 
311 		/* Update number of frames. */
312 		nfrms++;
313 	}
314 
315 	/* Unused length fields should be zero-filled (according to SPEC). */
316 	while (nfrms < CFHSI_MAX_PKTS) {
317 		desc->cffrm_len[nfrms] = 0x0000;
318 		nfrms++;
319 	}
320 
321 	/* Check if we can piggy-back another descriptor. */
322 	if (cfhsi_can_send_aggregate(cfhsi))
323 		desc->header |= CFHSI_PIGGY_DESC;
324 	else
325 		desc->header &= ~CFHSI_PIGGY_DESC;
326 
327 	return CFHSI_DESC_SZ + pld_len;
328 }
329 
cfhsi_start_tx(struct cfhsi * cfhsi)330 static void cfhsi_start_tx(struct cfhsi *cfhsi)
331 {
332 	struct cfhsi_desc *desc = (struct cfhsi_desc *)cfhsi->tx_buf;
333 	int len, res;
334 
335 	netdev_dbg(cfhsi->ndev, "%s.\n", __func__);
336 
337 	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
338 		return;
339 
340 	do {
341 		/* Create HSI frame. */
342 		len = cfhsi_tx_frm(desc, cfhsi);
343 		if (!len) {
344 			spin_lock_bh(&cfhsi->lock);
345 			if (unlikely(cfhsi_tx_queue_len(cfhsi))) {
346 				spin_unlock_bh(&cfhsi->lock);
347 				res = -EAGAIN;
348 				continue;
349 			}
350 			cfhsi->tx_state = CFHSI_TX_STATE_IDLE;
351 			/* Start inactivity timer. */
352 			mod_timer(&cfhsi->inactivity_timer,
353 				jiffies + cfhsi->cfg.inactivity_timeout);
354 			spin_unlock_bh(&cfhsi->lock);
355 			break;
356 		}
357 
358 		/* Set up new transfer. */
359 		res = cfhsi->ops->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->ops);
360 		if (WARN_ON(res < 0))
361 			netdev_err(cfhsi->ndev, "%s: TX error %d.\n",
362 				__func__, res);
363 	} while (res < 0);
364 }
365 
cfhsi_tx_done(struct cfhsi * cfhsi)366 static void cfhsi_tx_done(struct cfhsi *cfhsi)
367 {
368 	netdev_dbg(cfhsi->ndev, "%s.\n", __func__);
369 
370 	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
371 		return;
372 
373 	/*
374 	 * Send flow on if flow off has been previously signalled
375 	 * and number of packets is below low water mark.
376 	 */
377 	spin_lock_bh(&cfhsi->lock);
378 	if (cfhsi->flow_off_sent &&
379 			cfhsi_tx_queue_len(cfhsi) <= cfhsi->cfg.q_low_mark &&
380 			cfhsi->cfdev.flowctrl) {
381 
382 		cfhsi->flow_off_sent = 0;
383 		cfhsi->cfdev.flowctrl(cfhsi->ndev, ON);
384 	}
385 
386 	if (cfhsi_can_send_aggregate(cfhsi)) {
387 		spin_unlock_bh(&cfhsi->lock);
388 		cfhsi_start_tx(cfhsi);
389 	} else {
390 		mod_timer(&cfhsi->aggregation_timer,
391 			jiffies + cfhsi->cfg.aggregation_timeout);
392 		spin_unlock_bh(&cfhsi->lock);
393 	}
394 
395 	return;
396 }
397 
cfhsi_tx_done_cb(struct cfhsi_cb_ops * cb_ops)398 static void cfhsi_tx_done_cb(struct cfhsi_cb_ops *cb_ops)
399 {
400 	struct cfhsi *cfhsi;
401 
402 	cfhsi = container_of(cb_ops, struct cfhsi, cb_ops);
403 	netdev_dbg(cfhsi->ndev, "%s.\n",
404 		__func__);
405 
406 	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
407 		return;
408 	cfhsi_tx_done(cfhsi);
409 }
410 
cfhsi_rx_desc(struct cfhsi_desc * desc,struct cfhsi * cfhsi)411 static int cfhsi_rx_desc(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
412 {
413 	int xfer_sz = 0;
414 	int nfrms = 0;
415 	u16 *plen = NULL;
416 	u8 *pfrm = NULL;
417 
418 	if ((desc->header & ~CFHSI_PIGGY_DESC) ||
419 			(desc->offset > CFHSI_MAX_EMB_FRM_SZ)) {
420 		netdev_err(cfhsi->ndev, "%s: Invalid descriptor.\n",
421 			__func__);
422 		return -EPROTO;
423 	}
424 
425 	/* Check for embedded CAIF frame. */
426 	if (desc->offset) {
427 		struct sk_buff *skb;
428 		int len = 0;
429 		pfrm = ((u8 *)desc) + desc->offset;
430 
431 		/* Remove offset padding. */
432 		pfrm += *pfrm + 1;
433 
434 		/* Read length of CAIF frame (little endian). */
435 		len = *pfrm;
436 		len |= ((*(pfrm+1)) << 8) & 0xFF00;
437 		len += 2;	/* Add FCS fields. */
438 
439 		/* Sanity check length of CAIF frame. */
440 		if (unlikely(len > CFHSI_MAX_CAIF_FRAME_SZ)) {
441 			netdev_err(cfhsi->ndev, "%s: Invalid length.\n",
442 				__func__);
443 			return -EPROTO;
444 		}
445 
446 		/* Allocate SKB (OK even in IRQ context). */
447 		skb = alloc_skb(len + 1, GFP_ATOMIC);
448 		if (!skb) {
449 			netdev_err(cfhsi->ndev, "%s: Out of memory !\n",
450 				__func__);
451 			return -ENOMEM;
452 		}
453 		caif_assert(skb != NULL);
454 
455 		skb_put_data(skb, pfrm, len);
456 
457 		skb->protocol = htons(ETH_P_CAIF);
458 		skb_reset_mac_header(skb);
459 		skb->dev = cfhsi->ndev;
460 
461 		netif_rx_any_context(skb);
462 
463 		/* Update network statistics. */
464 		cfhsi->ndev->stats.rx_packets++;
465 		cfhsi->ndev->stats.rx_bytes += len;
466 	}
467 
468 	/* Calculate transfer length. */
469 	plen = desc->cffrm_len;
470 	while (nfrms < CFHSI_MAX_PKTS && *plen) {
471 		xfer_sz += *plen;
472 		plen++;
473 		nfrms++;
474 	}
475 
476 	/* Check for piggy-backed descriptor. */
477 	if (desc->header & CFHSI_PIGGY_DESC)
478 		xfer_sz += CFHSI_DESC_SZ;
479 
480 	if ((xfer_sz % 4) || (xfer_sz > (CFHSI_BUF_SZ_RX - CFHSI_DESC_SZ))) {
481 		netdev_err(cfhsi->ndev,
482 				"%s: Invalid payload len: %d, ignored.\n",
483 			__func__, xfer_sz);
484 		return -EPROTO;
485 	}
486 	return xfer_sz;
487 }
488 
cfhsi_rx_desc_len(struct cfhsi_desc * desc)489 static int cfhsi_rx_desc_len(struct cfhsi_desc *desc)
490 {
491 	int xfer_sz = 0;
492 	int nfrms = 0;
493 	u16 *plen;
494 
495 	if ((desc->header & ~CFHSI_PIGGY_DESC) ||
496 			(desc->offset > CFHSI_MAX_EMB_FRM_SZ)) {
497 
498 		pr_err("Invalid descriptor. %x %x\n", desc->header,
499 				desc->offset);
500 		return -EPROTO;
501 	}
502 
503 	/* Calculate transfer length. */
504 	plen = desc->cffrm_len;
505 	while (nfrms < CFHSI_MAX_PKTS && *plen) {
506 		xfer_sz += *plen;
507 		plen++;
508 		nfrms++;
509 	}
510 
511 	if (xfer_sz % 4) {
512 		pr_err("Invalid payload len: %d, ignored.\n", xfer_sz);
513 		return -EPROTO;
514 	}
515 	return xfer_sz;
516 }
517 
cfhsi_rx_pld(struct cfhsi_desc * desc,struct cfhsi * cfhsi)518 static int cfhsi_rx_pld(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
519 {
520 	int rx_sz = 0;
521 	int nfrms = 0;
522 	u16 *plen = NULL;
523 	u8 *pfrm = NULL;
524 
525 	/* Sanity check header and offset. */
526 	if (WARN_ON((desc->header & ~CFHSI_PIGGY_DESC) ||
527 			(desc->offset > CFHSI_MAX_EMB_FRM_SZ))) {
528 		netdev_err(cfhsi->ndev, "%s: Invalid descriptor.\n",
529 			__func__);
530 		return -EPROTO;
531 	}
532 
533 	/* Set frame pointer to start of payload. */
534 	pfrm = desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ;
535 	plen = desc->cffrm_len;
536 
537 	/* Skip already processed frames. */
538 	while (nfrms < cfhsi->rx_state.nfrms) {
539 		pfrm += *plen;
540 		rx_sz += *plen;
541 		plen++;
542 		nfrms++;
543 	}
544 
545 	/* Parse payload. */
546 	while (nfrms < CFHSI_MAX_PKTS && *plen) {
547 		struct sk_buff *skb;
548 		u8 *pcffrm = NULL;
549 		int len;
550 
551 		/* CAIF frame starts after head padding. */
552 		pcffrm = pfrm + *pfrm + 1;
553 
554 		/* Read length of CAIF frame (little endian). */
555 		len = *pcffrm;
556 		len |= ((*(pcffrm + 1)) << 8) & 0xFF00;
557 		len += 2;	/* Add FCS fields. */
558 
559 		/* Sanity check length of CAIF frames. */
560 		if (unlikely(len > CFHSI_MAX_CAIF_FRAME_SZ)) {
561 			netdev_err(cfhsi->ndev, "%s: Invalid length.\n",
562 				__func__);
563 			return -EPROTO;
564 		}
565 
566 		/* Allocate SKB (OK even in IRQ context). */
567 		skb = alloc_skb(len + 1, GFP_ATOMIC);
568 		if (!skb) {
569 			netdev_err(cfhsi->ndev, "%s: Out of memory !\n",
570 				__func__);
571 			cfhsi->rx_state.nfrms = nfrms;
572 			return -ENOMEM;
573 		}
574 		caif_assert(skb != NULL);
575 
576 		skb_put_data(skb, pcffrm, len);
577 
578 		skb->protocol = htons(ETH_P_CAIF);
579 		skb_reset_mac_header(skb);
580 		skb->dev = cfhsi->ndev;
581 
582 		netif_rx_any_context(skb);
583 
584 		/* Update network statistics. */
585 		cfhsi->ndev->stats.rx_packets++;
586 		cfhsi->ndev->stats.rx_bytes += len;
587 
588 		pfrm += *plen;
589 		rx_sz += *plen;
590 		plen++;
591 		nfrms++;
592 	}
593 
594 	return rx_sz;
595 }
596 
cfhsi_rx_done(struct cfhsi * cfhsi)597 static void cfhsi_rx_done(struct cfhsi *cfhsi)
598 {
599 	int res;
600 	int desc_pld_len = 0, rx_len, rx_state;
601 	struct cfhsi_desc *desc = NULL;
602 	u8 *rx_ptr, *rx_buf;
603 	struct cfhsi_desc *piggy_desc = NULL;
604 
605 	desc = (struct cfhsi_desc *)cfhsi->rx_buf;
606 
607 	netdev_dbg(cfhsi->ndev, "%s\n", __func__);
608 
609 	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
610 		return;
611 
612 	/* Update inactivity timer if pending. */
613 	spin_lock_bh(&cfhsi->lock);
614 	mod_timer_pending(&cfhsi->inactivity_timer,
615 			jiffies + cfhsi->cfg.inactivity_timeout);
616 	spin_unlock_bh(&cfhsi->lock);
617 
618 	if (cfhsi->rx_state.state == CFHSI_RX_STATE_DESC) {
619 		desc_pld_len = cfhsi_rx_desc_len(desc);
620 
621 		if (desc_pld_len < 0)
622 			goto out_of_sync;
623 
624 		rx_buf = cfhsi->rx_buf;
625 		rx_len = desc_pld_len;
626 		if (desc_pld_len > 0 && (desc->header & CFHSI_PIGGY_DESC))
627 			rx_len += CFHSI_DESC_SZ;
628 		if (desc_pld_len == 0)
629 			rx_buf = cfhsi->rx_flip_buf;
630 	} else {
631 		rx_buf = cfhsi->rx_flip_buf;
632 
633 		rx_len = CFHSI_DESC_SZ;
634 		if (cfhsi->rx_state.pld_len > 0 &&
635 				(desc->header & CFHSI_PIGGY_DESC)) {
636 
637 			piggy_desc = (struct cfhsi_desc *)
638 				(desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ +
639 						cfhsi->rx_state.pld_len);
640 
641 			cfhsi->rx_state.piggy_desc = true;
642 
643 			/* Extract payload len from piggy-backed descriptor. */
644 			desc_pld_len = cfhsi_rx_desc_len(piggy_desc);
645 			if (desc_pld_len < 0)
646 				goto out_of_sync;
647 
648 			if (desc_pld_len > 0) {
649 				rx_len = desc_pld_len;
650 				if (piggy_desc->header & CFHSI_PIGGY_DESC)
651 					rx_len += CFHSI_DESC_SZ;
652 			}
653 
654 			/*
655 			 * Copy needed information from the piggy-backed
656 			 * descriptor to the descriptor in the start.
657 			 */
658 			memcpy(rx_buf, (u8 *)piggy_desc,
659 					CFHSI_DESC_SHORT_SZ);
660 		}
661 	}
662 
663 	if (desc_pld_len) {
664 		rx_state = CFHSI_RX_STATE_PAYLOAD;
665 		rx_ptr = rx_buf + CFHSI_DESC_SZ;
666 	} else {
667 		rx_state = CFHSI_RX_STATE_DESC;
668 		rx_ptr = rx_buf;
669 		rx_len = CFHSI_DESC_SZ;
670 	}
671 
672 	/* Initiate next read */
673 	if (test_bit(CFHSI_AWAKE, &cfhsi->bits)) {
674 		/* Set up new transfer. */
675 		netdev_dbg(cfhsi->ndev, "%s: Start RX.\n",
676 				__func__);
677 
678 		res = cfhsi->ops->cfhsi_rx(rx_ptr, rx_len,
679 				cfhsi->ops);
680 		if (WARN_ON(res < 0)) {
681 			netdev_err(cfhsi->ndev, "%s: RX error %d.\n",
682 				__func__, res);
683 			cfhsi->ndev->stats.rx_errors++;
684 			cfhsi->ndev->stats.rx_dropped++;
685 		}
686 	}
687 
688 	if (cfhsi->rx_state.state == CFHSI_RX_STATE_DESC) {
689 		/* Extract payload from descriptor */
690 		if (cfhsi_rx_desc(desc, cfhsi) < 0)
691 			goto out_of_sync;
692 	} else {
693 		/* Extract payload */
694 		if (cfhsi_rx_pld(desc, cfhsi) < 0)
695 			goto out_of_sync;
696 		if (piggy_desc) {
697 			/* Extract any payload in piggyback descriptor. */
698 			if (cfhsi_rx_desc(piggy_desc, cfhsi) < 0)
699 				goto out_of_sync;
700 			/* Mark no embedded frame after extracting it */
701 			piggy_desc->offset = 0;
702 		}
703 	}
704 
705 	/* Update state info */
706 	memset(&cfhsi->rx_state, 0, sizeof(cfhsi->rx_state));
707 	cfhsi->rx_state.state = rx_state;
708 	cfhsi->rx_ptr = rx_ptr;
709 	cfhsi->rx_len = rx_len;
710 	cfhsi->rx_state.pld_len = desc_pld_len;
711 	cfhsi->rx_state.piggy_desc = desc->header & CFHSI_PIGGY_DESC;
712 
713 	if (rx_buf != cfhsi->rx_buf)
714 		swap(cfhsi->rx_buf, cfhsi->rx_flip_buf);
715 	return;
716 
717 out_of_sync:
718 	netdev_err(cfhsi->ndev, "%s: Out of sync.\n", __func__);
719 	print_hex_dump_bytes("--> ", DUMP_PREFIX_NONE,
720 			cfhsi->rx_buf, CFHSI_DESC_SZ);
721 	schedule_work(&cfhsi->out_of_sync_work);
722 }
723 
cfhsi_rx_slowpath(struct timer_list * t)724 static void cfhsi_rx_slowpath(struct timer_list *t)
725 {
726 	struct cfhsi *cfhsi = from_timer(cfhsi, t, rx_slowpath_timer);
727 
728 	netdev_dbg(cfhsi->ndev, "%s.\n",
729 		__func__);
730 
731 	cfhsi_rx_done(cfhsi);
732 }
733 
cfhsi_rx_done_cb(struct cfhsi_cb_ops * cb_ops)734 static void cfhsi_rx_done_cb(struct cfhsi_cb_ops *cb_ops)
735 {
736 	struct cfhsi *cfhsi;
737 
738 	cfhsi = container_of(cb_ops, struct cfhsi, cb_ops);
739 	netdev_dbg(cfhsi->ndev, "%s.\n",
740 		__func__);
741 
742 	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
743 		return;
744 
745 	if (test_and_clear_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits))
746 		wake_up_interruptible(&cfhsi->flush_fifo_wait);
747 	else
748 		cfhsi_rx_done(cfhsi);
749 }
750 
cfhsi_wake_up(struct work_struct * work)751 static void cfhsi_wake_up(struct work_struct *work)
752 {
753 	struct cfhsi *cfhsi = NULL;
754 	int res;
755 	int len;
756 	long ret;
757 
758 	cfhsi = container_of(work, struct cfhsi, wake_up_work);
759 
760 	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
761 		return;
762 
763 	if (unlikely(test_bit(CFHSI_AWAKE, &cfhsi->bits))) {
764 		/* It happenes when wakeup is requested by
765 		 * both ends at the same time. */
766 		clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
767 		clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
768 		return;
769 	}
770 
771 	/* Activate wake line. */
772 	cfhsi->ops->cfhsi_wake_up(cfhsi->ops);
773 
774 	netdev_dbg(cfhsi->ndev, "%s: Start waiting.\n",
775 		__func__);
776 
777 	/* Wait for acknowledge. */
778 	ret = CFHSI_WAKE_TOUT;
779 	ret = wait_event_interruptible_timeout(cfhsi->wake_up_wait,
780 					test_and_clear_bit(CFHSI_WAKE_UP_ACK,
781 							&cfhsi->bits), ret);
782 	if (unlikely(ret < 0)) {
783 		/* Interrupted by signal. */
784 		netdev_err(cfhsi->ndev, "%s: Signalled: %ld.\n",
785 			__func__, ret);
786 
787 		clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
788 		cfhsi->ops->cfhsi_wake_down(cfhsi->ops);
789 		return;
790 	} else if (!ret) {
791 		bool ca_wake = false;
792 		size_t fifo_occupancy = 0;
793 
794 		/* Wakeup timeout */
795 		netdev_dbg(cfhsi->ndev, "%s: Timeout.\n",
796 			__func__);
797 
798 		/* Check FIFO to check if modem has sent something. */
799 		WARN_ON(cfhsi->ops->cfhsi_fifo_occupancy(cfhsi->ops,
800 					&fifo_occupancy));
801 
802 		netdev_dbg(cfhsi->ndev, "%s: Bytes in FIFO: %u.\n",
803 				__func__, (unsigned) fifo_occupancy);
804 
805 		/* Check if we misssed the interrupt. */
806 		WARN_ON(cfhsi->ops->cfhsi_get_peer_wake(cfhsi->ops,
807 							&ca_wake));
808 
809 		if (ca_wake) {
810 			netdev_err(cfhsi->ndev, "%s: CA Wake missed !.\n",
811 				__func__);
812 
813 			/* Clear the CFHSI_WAKE_UP_ACK bit to prevent race. */
814 			clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
815 
816 			/* Continue execution. */
817 			goto wake_ack;
818 		}
819 
820 		clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
821 		cfhsi->ops->cfhsi_wake_down(cfhsi->ops);
822 		return;
823 	}
824 wake_ack:
825 	netdev_dbg(cfhsi->ndev, "%s: Woken.\n",
826 		__func__);
827 
828 	/* Clear power up bit. */
829 	set_bit(CFHSI_AWAKE, &cfhsi->bits);
830 	clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
831 
832 	/* Resume read operation. */
833 	netdev_dbg(cfhsi->ndev, "%s: Start RX.\n", __func__);
834 	res = cfhsi->ops->cfhsi_rx(cfhsi->rx_ptr, cfhsi->rx_len, cfhsi->ops);
835 
836 	if (WARN_ON(res < 0))
837 		netdev_err(cfhsi->ndev, "%s: RX err %d.\n", __func__, res);
838 
839 	/* Clear power up acknowledment. */
840 	clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
841 
842 	spin_lock_bh(&cfhsi->lock);
843 
844 	/* Resume transmit if queues are not empty. */
845 	if (!cfhsi_tx_queue_len(cfhsi)) {
846 		netdev_dbg(cfhsi->ndev, "%s: Peer wake, start timer.\n",
847 			__func__);
848 		/* Start inactivity timer. */
849 		mod_timer(&cfhsi->inactivity_timer,
850 				jiffies + cfhsi->cfg.inactivity_timeout);
851 		spin_unlock_bh(&cfhsi->lock);
852 		return;
853 	}
854 
855 	netdev_dbg(cfhsi->ndev, "%s: Host wake.\n",
856 		__func__);
857 
858 	spin_unlock_bh(&cfhsi->lock);
859 
860 	/* Create HSI frame. */
861 	len = cfhsi_tx_frm((struct cfhsi_desc *)cfhsi->tx_buf, cfhsi);
862 
863 	if (likely(len > 0)) {
864 		/* Set up new transfer. */
865 		res = cfhsi->ops->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->ops);
866 		if (WARN_ON(res < 0)) {
867 			netdev_err(cfhsi->ndev, "%s: TX error %d.\n",
868 				__func__, res);
869 			cfhsi_abort_tx(cfhsi);
870 		}
871 	} else {
872 		netdev_err(cfhsi->ndev,
873 				"%s: Failed to create HSI frame: %d.\n",
874 				__func__, len);
875 	}
876 }
877 
cfhsi_wake_down(struct work_struct * work)878 static void cfhsi_wake_down(struct work_struct *work)
879 {
880 	long ret;
881 	struct cfhsi *cfhsi = NULL;
882 	size_t fifo_occupancy = 0;
883 	int retry = CFHSI_WAKE_TOUT;
884 
885 	cfhsi = container_of(work, struct cfhsi, wake_down_work);
886 	netdev_dbg(cfhsi->ndev, "%s.\n", __func__);
887 
888 	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
889 		return;
890 
891 	/* Deactivate wake line. */
892 	cfhsi->ops->cfhsi_wake_down(cfhsi->ops);
893 
894 	/* Wait for acknowledge. */
895 	ret = CFHSI_WAKE_TOUT;
896 	ret = wait_event_interruptible_timeout(cfhsi->wake_down_wait,
897 					test_and_clear_bit(CFHSI_WAKE_DOWN_ACK,
898 							&cfhsi->bits), ret);
899 	if (ret < 0) {
900 		/* Interrupted by signal. */
901 		netdev_err(cfhsi->ndev, "%s: Signalled: %ld.\n",
902 			__func__, ret);
903 		return;
904 	} else if (!ret) {
905 		bool ca_wake = true;
906 
907 		/* Timeout */
908 		netdev_err(cfhsi->ndev, "%s: Timeout.\n", __func__);
909 
910 		/* Check if we misssed the interrupt. */
911 		WARN_ON(cfhsi->ops->cfhsi_get_peer_wake(cfhsi->ops,
912 							&ca_wake));
913 		if (!ca_wake)
914 			netdev_err(cfhsi->ndev, "%s: CA Wake missed !.\n",
915 				__func__);
916 	}
917 
918 	/* Check FIFO occupancy. */
919 	while (retry) {
920 		WARN_ON(cfhsi->ops->cfhsi_fifo_occupancy(cfhsi->ops,
921 							&fifo_occupancy));
922 
923 		if (!fifo_occupancy)
924 			break;
925 
926 		set_current_state(TASK_INTERRUPTIBLE);
927 		schedule_timeout(1);
928 		retry--;
929 	}
930 
931 	if (!retry)
932 		netdev_err(cfhsi->ndev, "%s: FIFO Timeout.\n", __func__);
933 
934 	/* Clear AWAKE condition. */
935 	clear_bit(CFHSI_AWAKE, &cfhsi->bits);
936 
937 	/* Cancel pending RX requests. */
938 	cfhsi->ops->cfhsi_rx_cancel(cfhsi->ops);
939 }
940 
cfhsi_out_of_sync(struct work_struct * work)941 static void cfhsi_out_of_sync(struct work_struct *work)
942 {
943 	struct cfhsi *cfhsi = NULL;
944 
945 	cfhsi = container_of(work, struct cfhsi, out_of_sync_work);
946 
947 	rtnl_lock();
948 	dev_close(cfhsi->ndev);
949 	rtnl_unlock();
950 }
951 
cfhsi_wake_up_cb(struct cfhsi_cb_ops * cb_ops)952 static void cfhsi_wake_up_cb(struct cfhsi_cb_ops *cb_ops)
953 {
954 	struct cfhsi *cfhsi = NULL;
955 
956 	cfhsi = container_of(cb_ops, struct cfhsi, cb_ops);
957 	netdev_dbg(cfhsi->ndev, "%s.\n",
958 		__func__);
959 
960 	set_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
961 	wake_up_interruptible(&cfhsi->wake_up_wait);
962 
963 	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
964 		return;
965 
966 	/* Schedule wake up work queue if the peer initiates. */
967 	if (!test_and_set_bit(CFHSI_WAKE_UP, &cfhsi->bits))
968 		queue_work(cfhsi->wq, &cfhsi->wake_up_work);
969 }
970 
cfhsi_wake_down_cb(struct cfhsi_cb_ops * cb_ops)971 static void cfhsi_wake_down_cb(struct cfhsi_cb_ops *cb_ops)
972 {
973 	struct cfhsi *cfhsi = NULL;
974 
975 	cfhsi = container_of(cb_ops, struct cfhsi, cb_ops);
976 	netdev_dbg(cfhsi->ndev, "%s.\n",
977 		__func__);
978 
979 	/* Initiating low power is only permitted by the host (us). */
980 	set_bit(CFHSI_WAKE_DOWN_ACK, &cfhsi->bits);
981 	wake_up_interruptible(&cfhsi->wake_down_wait);
982 }
983 
cfhsi_aggregation_tout(struct timer_list * t)984 static void cfhsi_aggregation_tout(struct timer_list *t)
985 {
986 	struct cfhsi *cfhsi = from_timer(cfhsi, t, aggregation_timer);
987 
988 	netdev_dbg(cfhsi->ndev, "%s.\n",
989 		__func__);
990 
991 	cfhsi_start_tx(cfhsi);
992 }
993 
cfhsi_xmit(struct sk_buff * skb,struct net_device * dev)994 static netdev_tx_t cfhsi_xmit(struct sk_buff *skb, struct net_device *dev)
995 {
996 	struct cfhsi *cfhsi = NULL;
997 	int start_xfer = 0;
998 	int timer_active;
999 	int prio;
1000 
1001 	if (!dev)
1002 		return -EINVAL;
1003 
1004 	cfhsi = netdev_priv(dev);
1005 
1006 	switch (skb->priority) {
1007 	case TC_PRIO_BESTEFFORT:
1008 	case TC_PRIO_FILLER:
1009 	case TC_PRIO_BULK:
1010 		prio = CFHSI_PRIO_BEBK;
1011 		break;
1012 	case TC_PRIO_INTERACTIVE_BULK:
1013 		prio = CFHSI_PRIO_VI;
1014 		break;
1015 	case TC_PRIO_INTERACTIVE:
1016 		prio = CFHSI_PRIO_VO;
1017 		break;
1018 	case TC_PRIO_CONTROL:
1019 	default:
1020 		prio = CFHSI_PRIO_CTL;
1021 		break;
1022 	}
1023 
1024 	spin_lock_bh(&cfhsi->lock);
1025 
1026 	/* Update aggregation statistics  */
1027 	cfhsi_update_aggregation_stats(cfhsi, skb, 1);
1028 
1029 	/* Queue the SKB */
1030 	skb_queue_tail(&cfhsi->qhead[prio], skb);
1031 
1032 	/* Sanity check; xmit should not be called after unregister_netdev */
1033 	if (WARN_ON(test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))) {
1034 		spin_unlock_bh(&cfhsi->lock);
1035 		cfhsi_abort_tx(cfhsi);
1036 		return -EINVAL;
1037 	}
1038 
1039 	/* Send flow off if number of packets is above high water mark. */
1040 	if (!cfhsi->flow_off_sent &&
1041 		cfhsi_tx_queue_len(cfhsi) > cfhsi->cfg.q_high_mark &&
1042 		cfhsi->cfdev.flowctrl) {
1043 		cfhsi->flow_off_sent = 1;
1044 		cfhsi->cfdev.flowctrl(cfhsi->ndev, OFF);
1045 	}
1046 
1047 	if (cfhsi->tx_state == CFHSI_TX_STATE_IDLE) {
1048 		cfhsi->tx_state = CFHSI_TX_STATE_XFER;
1049 		start_xfer = 1;
1050 	}
1051 
1052 	if (!start_xfer) {
1053 		/* Send aggregate if it is possible */
1054 		bool aggregate_ready =
1055 			cfhsi_can_send_aggregate(cfhsi) &&
1056 			del_timer(&cfhsi->aggregation_timer) > 0;
1057 		spin_unlock_bh(&cfhsi->lock);
1058 		if (aggregate_ready)
1059 			cfhsi_start_tx(cfhsi);
1060 		return NETDEV_TX_OK;
1061 	}
1062 
1063 	/* Delete inactivity timer if started. */
1064 	timer_active = del_timer_sync(&cfhsi->inactivity_timer);
1065 
1066 	spin_unlock_bh(&cfhsi->lock);
1067 
1068 	if (timer_active) {
1069 		struct cfhsi_desc *desc = (struct cfhsi_desc *)cfhsi->tx_buf;
1070 		int len;
1071 		int res;
1072 
1073 		/* Create HSI frame. */
1074 		len = cfhsi_tx_frm(desc, cfhsi);
1075 		WARN_ON(!len);
1076 
1077 		/* Set up new transfer. */
1078 		res = cfhsi->ops->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->ops);
1079 		if (WARN_ON(res < 0)) {
1080 			netdev_err(cfhsi->ndev, "%s: TX error %d.\n",
1081 				__func__, res);
1082 			cfhsi_abort_tx(cfhsi);
1083 		}
1084 	} else {
1085 		/* Schedule wake up work queue if the we initiate. */
1086 		if (!test_and_set_bit(CFHSI_WAKE_UP, &cfhsi->bits))
1087 			queue_work(cfhsi->wq, &cfhsi->wake_up_work);
1088 	}
1089 
1090 	return NETDEV_TX_OK;
1091 }
1092 
1093 static const struct net_device_ops cfhsi_netdevops;
1094 
cfhsi_setup(struct net_device * dev)1095 static void cfhsi_setup(struct net_device *dev)
1096 {
1097 	int i;
1098 	struct cfhsi *cfhsi = netdev_priv(dev);
1099 	dev->features = 0;
1100 	dev->type = ARPHRD_CAIF;
1101 	dev->flags = IFF_POINTOPOINT | IFF_NOARP;
1102 	dev->mtu = CFHSI_MAX_CAIF_FRAME_SZ;
1103 	dev->priv_flags |= IFF_NO_QUEUE;
1104 	dev->needs_free_netdev = true;
1105 	dev->netdev_ops = &cfhsi_netdevops;
1106 	for (i = 0; i < CFHSI_PRIO_LAST; ++i)
1107 		skb_queue_head_init(&cfhsi->qhead[i]);
1108 	cfhsi->cfdev.link_select = CAIF_LINK_HIGH_BANDW;
1109 	cfhsi->cfdev.use_frag = false;
1110 	cfhsi->cfdev.use_stx = false;
1111 	cfhsi->cfdev.use_fcs = false;
1112 	cfhsi->ndev = dev;
1113 	cfhsi->cfg = hsi_default_config;
1114 }
1115 
cfhsi_open(struct net_device * ndev)1116 static int cfhsi_open(struct net_device *ndev)
1117 {
1118 	struct cfhsi *cfhsi = netdev_priv(ndev);
1119 	int res;
1120 
1121 	clear_bit(CFHSI_SHUTDOWN, &cfhsi->bits);
1122 
1123 	/* Initialize state vaiables. */
1124 	cfhsi->tx_state = CFHSI_TX_STATE_IDLE;
1125 	cfhsi->rx_state.state = CFHSI_RX_STATE_DESC;
1126 
1127 	/* Set flow info */
1128 	cfhsi->flow_off_sent = 0;
1129 
1130 	/*
1131 	 * Allocate a TX buffer with the size of a HSI packet descriptors
1132 	 * and the necessary room for CAIF payload frames.
1133 	 */
1134 	cfhsi->tx_buf = kzalloc(CFHSI_BUF_SZ_TX, GFP_KERNEL);
1135 	if (!cfhsi->tx_buf) {
1136 		res = -ENODEV;
1137 		goto err_alloc_tx;
1138 	}
1139 
1140 	/*
1141 	 * Allocate a RX buffer with the size of two HSI packet descriptors and
1142 	 * the necessary room for CAIF payload frames.
1143 	 */
1144 	cfhsi->rx_buf = kzalloc(CFHSI_BUF_SZ_RX, GFP_KERNEL);
1145 	if (!cfhsi->rx_buf) {
1146 		res = -ENODEV;
1147 		goto err_alloc_rx;
1148 	}
1149 
1150 	cfhsi->rx_flip_buf = kzalloc(CFHSI_BUF_SZ_RX, GFP_KERNEL);
1151 	if (!cfhsi->rx_flip_buf) {
1152 		res = -ENODEV;
1153 		goto err_alloc_rx_flip;
1154 	}
1155 
1156 	/* Initialize aggregation timeout */
1157 	cfhsi->cfg.aggregation_timeout = hsi_default_config.aggregation_timeout;
1158 
1159 	/* Initialize recieve vaiables. */
1160 	cfhsi->rx_ptr = cfhsi->rx_buf;
1161 	cfhsi->rx_len = CFHSI_DESC_SZ;
1162 
1163 	/* Initialize spin locks. */
1164 	spin_lock_init(&cfhsi->lock);
1165 
1166 	/* Set up the driver. */
1167 	cfhsi->cb_ops.tx_done_cb = cfhsi_tx_done_cb;
1168 	cfhsi->cb_ops.rx_done_cb = cfhsi_rx_done_cb;
1169 	cfhsi->cb_ops.wake_up_cb = cfhsi_wake_up_cb;
1170 	cfhsi->cb_ops.wake_down_cb = cfhsi_wake_down_cb;
1171 
1172 	/* Initialize the work queues. */
1173 	INIT_WORK(&cfhsi->wake_up_work, cfhsi_wake_up);
1174 	INIT_WORK(&cfhsi->wake_down_work, cfhsi_wake_down);
1175 	INIT_WORK(&cfhsi->out_of_sync_work, cfhsi_out_of_sync);
1176 
1177 	/* Clear all bit fields. */
1178 	clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
1179 	clear_bit(CFHSI_WAKE_DOWN_ACK, &cfhsi->bits);
1180 	clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
1181 	clear_bit(CFHSI_AWAKE, &cfhsi->bits);
1182 
1183 	/* Create work thread. */
1184 	cfhsi->wq = alloc_ordered_workqueue(cfhsi->ndev->name, WQ_MEM_RECLAIM);
1185 	if (!cfhsi->wq) {
1186 		netdev_err(cfhsi->ndev, "%s: Failed to create work queue.\n",
1187 			__func__);
1188 		res = -ENODEV;
1189 		goto err_create_wq;
1190 	}
1191 
1192 	/* Initialize wait queues. */
1193 	init_waitqueue_head(&cfhsi->wake_up_wait);
1194 	init_waitqueue_head(&cfhsi->wake_down_wait);
1195 	init_waitqueue_head(&cfhsi->flush_fifo_wait);
1196 
1197 	/* Setup the inactivity timer. */
1198 	timer_setup(&cfhsi->inactivity_timer, cfhsi_inactivity_tout, 0);
1199 	/* Setup the slowpath RX timer. */
1200 	timer_setup(&cfhsi->rx_slowpath_timer, cfhsi_rx_slowpath, 0);
1201 	/* Setup the aggregation timer. */
1202 	timer_setup(&cfhsi->aggregation_timer, cfhsi_aggregation_tout, 0);
1203 
1204 	/* Activate HSI interface. */
1205 	res = cfhsi->ops->cfhsi_up(cfhsi->ops);
1206 	if (res) {
1207 		netdev_err(cfhsi->ndev,
1208 			"%s: can't activate HSI interface: %d.\n",
1209 			__func__, res);
1210 		goto err_activate;
1211 	}
1212 
1213 	/* Flush FIFO */
1214 	res = cfhsi_flush_fifo(cfhsi);
1215 	if (res) {
1216 		netdev_err(cfhsi->ndev, "%s: Can't flush FIFO: %d.\n",
1217 			__func__, res);
1218 		goto err_net_reg;
1219 	}
1220 	return res;
1221 
1222  err_net_reg:
1223 	cfhsi->ops->cfhsi_down(cfhsi->ops);
1224  err_activate:
1225 	destroy_workqueue(cfhsi->wq);
1226  err_create_wq:
1227 	kfree(cfhsi->rx_flip_buf);
1228  err_alloc_rx_flip:
1229 	kfree(cfhsi->rx_buf);
1230  err_alloc_rx:
1231 	kfree(cfhsi->tx_buf);
1232  err_alloc_tx:
1233 	return res;
1234 }
1235 
cfhsi_close(struct net_device * ndev)1236 static int cfhsi_close(struct net_device *ndev)
1237 {
1238 	struct cfhsi *cfhsi = netdev_priv(ndev);
1239 	u8 *tx_buf, *rx_buf, *flip_buf;
1240 
1241 	/* going to shutdown driver */
1242 	set_bit(CFHSI_SHUTDOWN, &cfhsi->bits);
1243 
1244 	/* Delete timers if pending */
1245 	del_timer_sync(&cfhsi->inactivity_timer);
1246 	del_timer_sync(&cfhsi->rx_slowpath_timer);
1247 	del_timer_sync(&cfhsi->aggregation_timer);
1248 
1249 	/* Cancel pending RX request (if any) */
1250 	cfhsi->ops->cfhsi_rx_cancel(cfhsi->ops);
1251 
1252 	/* Destroy workqueue */
1253 	destroy_workqueue(cfhsi->wq);
1254 
1255 	/* Store bufferes: will be freed later. */
1256 	tx_buf = cfhsi->tx_buf;
1257 	rx_buf = cfhsi->rx_buf;
1258 	flip_buf = cfhsi->rx_flip_buf;
1259 	/* Flush transmit queues. */
1260 	cfhsi_abort_tx(cfhsi);
1261 
1262 	/* Deactivate interface */
1263 	cfhsi->ops->cfhsi_down(cfhsi->ops);
1264 
1265 	/* Free buffers. */
1266 	kfree(tx_buf);
1267 	kfree(rx_buf);
1268 	kfree(flip_buf);
1269 	return 0;
1270 }
1271 
cfhsi_uninit(struct net_device * dev)1272 static void cfhsi_uninit(struct net_device *dev)
1273 {
1274 	struct cfhsi *cfhsi = netdev_priv(dev);
1275 	ASSERT_RTNL();
1276 	symbol_put(cfhsi_get_device);
1277 	list_del(&cfhsi->list);
1278 }
1279 
1280 static const struct net_device_ops cfhsi_netdevops = {
1281 	.ndo_uninit = cfhsi_uninit,
1282 	.ndo_open = cfhsi_open,
1283 	.ndo_stop = cfhsi_close,
1284 	.ndo_start_xmit = cfhsi_xmit
1285 };
1286 
cfhsi_netlink_parms(struct nlattr * data[],struct cfhsi * cfhsi)1287 static void cfhsi_netlink_parms(struct nlattr *data[], struct cfhsi *cfhsi)
1288 {
1289 	int i;
1290 
1291 	if (!data) {
1292 		pr_debug("no params data found\n");
1293 		return;
1294 	}
1295 
1296 	i = __IFLA_CAIF_HSI_INACTIVITY_TOUT;
1297 	/*
1298 	 * Inactivity timeout in millisecs. Lowest possible value is 1,
1299 	 * and highest possible is NEXT_TIMER_MAX_DELTA.
1300 	 */
1301 	if (data[i]) {
1302 		u32 inactivity_timeout = nla_get_u32(data[i]);
1303 		/* Pre-calculate inactivity timeout. */
1304 		cfhsi->cfg.inactivity_timeout =	inactivity_timeout * HZ / 1000;
1305 		if (cfhsi->cfg.inactivity_timeout == 0)
1306 			cfhsi->cfg.inactivity_timeout = 1;
1307 		else if (cfhsi->cfg.inactivity_timeout > NEXT_TIMER_MAX_DELTA)
1308 			cfhsi->cfg.inactivity_timeout = NEXT_TIMER_MAX_DELTA;
1309 	}
1310 
1311 	i = __IFLA_CAIF_HSI_AGGREGATION_TOUT;
1312 	if (data[i])
1313 		cfhsi->cfg.aggregation_timeout = nla_get_u32(data[i]);
1314 
1315 	i = __IFLA_CAIF_HSI_HEAD_ALIGN;
1316 	if (data[i])
1317 		cfhsi->cfg.head_align = nla_get_u32(data[i]);
1318 
1319 	i = __IFLA_CAIF_HSI_TAIL_ALIGN;
1320 	if (data[i])
1321 		cfhsi->cfg.tail_align = nla_get_u32(data[i]);
1322 
1323 	i = __IFLA_CAIF_HSI_QHIGH_WATERMARK;
1324 	if (data[i])
1325 		cfhsi->cfg.q_high_mark = nla_get_u32(data[i]);
1326 
1327 	i = __IFLA_CAIF_HSI_QLOW_WATERMARK;
1328 	if (data[i])
1329 		cfhsi->cfg.q_low_mark = nla_get_u32(data[i]);
1330 }
1331 
caif_hsi_changelink(struct net_device * dev,struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)1332 static int caif_hsi_changelink(struct net_device *dev, struct nlattr *tb[],
1333 			       struct nlattr *data[],
1334 			       struct netlink_ext_ack *extack)
1335 {
1336 	cfhsi_netlink_parms(data, netdev_priv(dev));
1337 	netdev_state_change(dev);
1338 	return 0;
1339 }
1340 
1341 static const struct nla_policy caif_hsi_policy[__IFLA_CAIF_HSI_MAX + 1] = {
1342 	[__IFLA_CAIF_HSI_INACTIVITY_TOUT] = { .type = NLA_U32, .len = 4 },
1343 	[__IFLA_CAIF_HSI_AGGREGATION_TOUT] = { .type = NLA_U32, .len = 4 },
1344 	[__IFLA_CAIF_HSI_HEAD_ALIGN] = { .type = NLA_U32, .len = 4 },
1345 	[__IFLA_CAIF_HSI_TAIL_ALIGN] = { .type = NLA_U32, .len = 4 },
1346 	[__IFLA_CAIF_HSI_QHIGH_WATERMARK] = { .type = NLA_U32, .len = 4 },
1347 	[__IFLA_CAIF_HSI_QLOW_WATERMARK] = { .type = NLA_U32, .len = 4 },
1348 };
1349 
caif_hsi_get_size(const struct net_device * dev)1350 static size_t caif_hsi_get_size(const struct net_device *dev)
1351 {
1352 	int i;
1353 	size_t s = 0;
1354 	for (i = __IFLA_CAIF_HSI_UNSPEC + 1; i < __IFLA_CAIF_HSI_MAX; i++)
1355 		s += nla_total_size(caif_hsi_policy[i].len);
1356 	return s;
1357 }
1358 
caif_hsi_fill_info(struct sk_buff * skb,const struct net_device * dev)1359 static int caif_hsi_fill_info(struct sk_buff *skb, const struct net_device *dev)
1360 {
1361 	struct cfhsi *cfhsi = netdev_priv(dev);
1362 
1363 	if (nla_put_u32(skb, __IFLA_CAIF_HSI_INACTIVITY_TOUT,
1364 			cfhsi->cfg.inactivity_timeout) ||
1365 	    nla_put_u32(skb, __IFLA_CAIF_HSI_AGGREGATION_TOUT,
1366 			cfhsi->cfg.aggregation_timeout) ||
1367 	    nla_put_u32(skb, __IFLA_CAIF_HSI_HEAD_ALIGN,
1368 			cfhsi->cfg.head_align) ||
1369 	    nla_put_u32(skb, __IFLA_CAIF_HSI_TAIL_ALIGN,
1370 			cfhsi->cfg.tail_align) ||
1371 	    nla_put_u32(skb, __IFLA_CAIF_HSI_QHIGH_WATERMARK,
1372 			cfhsi->cfg.q_high_mark) ||
1373 	    nla_put_u32(skb, __IFLA_CAIF_HSI_QLOW_WATERMARK,
1374 			cfhsi->cfg.q_low_mark))
1375 		return -EMSGSIZE;
1376 
1377 	return 0;
1378 }
1379 
caif_hsi_newlink(struct net * src_net,struct net_device * dev,struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)1380 static int caif_hsi_newlink(struct net *src_net, struct net_device *dev,
1381 			    struct nlattr *tb[], struct nlattr *data[],
1382 			    struct netlink_ext_ack *extack)
1383 {
1384 	struct cfhsi *cfhsi = NULL;
1385 	struct cfhsi_ops *(*get_ops)(void);
1386 
1387 	ASSERT_RTNL();
1388 
1389 	cfhsi = netdev_priv(dev);
1390 	cfhsi_netlink_parms(data, cfhsi);
1391 
1392 	get_ops = symbol_get(cfhsi_get_ops);
1393 	if (!get_ops) {
1394 		pr_err("%s: failed to get the cfhsi_ops\n", __func__);
1395 		return -ENODEV;
1396 	}
1397 
1398 	/* Assign the HSI device. */
1399 	cfhsi->ops = (*get_ops)();
1400 	if (!cfhsi->ops) {
1401 		pr_err("%s: failed to get the cfhsi_ops\n", __func__);
1402 		goto err;
1403 	}
1404 
1405 	/* Assign the driver to this HSI device. */
1406 	cfhsi->ops->cb_ops = &cfhsi->cb_ops;
1407 	if (register_netdevice(dev)) {
1408 		pr_warn("%s: caif_hsi device registration failed\n", __func__);
1409 		goto err;
1410 	}
1411 	/* Add CAIF HSI device to list. */
1412 	list_add_tail(&cfhsi->list, &cfhsi_list);
1413 
1414 	return 0;
1415 err:
1416 	symbol_put(cfhsi_get_ops);
1417 	return -ENODEV;
1418 }
1419 
1420 static struct rtnl_link_ops caif_hsi_link_ops __read_mostly = {
1421 	.kind		= "cfhsi",
1422 	.priv_size	= sizeof(struct cfhsi),
1423 	.setup		= cfhsi_setup,
1424 	.maxtype	= __IFLA_CAIF_HSI_MAX,
1425 	.policy	= caif_hsi_policy,
1426 	.newlink	= caif_hsi_newlink,
1427 	.changelink	= caif_hsi_changelink,
1428 	.get_size	= caif_hsi_get_size,
1429 	.fill_info	= caif_hsi_fill_info,
1430 };
1431 
cfhsi_exit_module(void)1432 static void __exit cfhsi_exit_module(void)
1433 {
1434 	struct list_head *list_node;
1435 	struct list_head *n;
1436 	struct cfhsi *cfhsi;
1437 
1438 	rtnl_link_unregister(&caif_hsi_link_ops);
1439 
1440 	rtnl_lock();
1441 	list_for_each_safe(list_node, n, &cfhsi_list) {
1442 		cfhsi = list_entry(list_node, struct cfhsi, list);
1443 		unregister_netdevice(cfhsi->ndev);
1444 	}
1445 	rtnl_unlock();
1446 }
1447 
cfhsi_init_module(void)1448 static int __init cfhsi_init_module(void)
1449 {
1450 	return rtnl_link_register(&caif_hsi_link_ops);
1451 }
1452 
1453 module_init(cfhsi_init_module);
1454 module_exit(cfhsi_exit_module);
1455