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1 /*
2  * Copyright (C) ST-Ericsson AB 2010
3  * Author:  Daniel Martensson
4  *	    Dmitry.Tarnyagin  / dmitry.tarnyagin@lockless.no
5  * License terms: GNU General Public License (GPL) version 2.
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(unsigned long arg)69 static void cfhsi_inactivity_tout(unsigned long arg)
70 {
71 	struct cfhsi *cfhsi = (struct cfhsi *)arg;
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 	pfrm = desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ;
268 	while (nfrms < CFHSI_MAX_PKTS) {
269 		struct caif_payload_info *info;
270 		int hpad;
271 		int tpad;
272 
273 		if (!skb)
274 			skb = cfhsi_dequeue(cfhsi);
275 
276 		if (!skb)
277 			break;
278 
279 		/* Calculate needed head alignment and tail alignment. */
280 		info = (struct caif_payload_info *)&skb->cb;
281 
282 		hpad = 1 + PAD_POW2((info->hdr_len + 1), cfhsi->cfg.head_align);
283 		tpad = PAD_POW2((skb->len + hpad), cfhsi->cfg.tail_align);
284 
285 		/* Fill in CAIF frame length in descriptor. */
286 		desc->cffrm_len[nfrms] = hpad + skb->len + tpad;
287 
288 		/* Fill head padding information. */
289 		*pfrm = (u8)(hpad - 1);
290 		pfrm += hpad;
291 
292 		/* Update network statistics. */
293 		spin_lock_bh(&cfhsi->lock);
294 		cfhsi->ndev->stats.tx_packets++;
295 		cfhsi->ndev->stats.tx_bytes += skb->len;
296 		cfhsi_update_aggregation_stats(cfhsi, skb, -1);
297 		spin_unlock_bh(&cfhsi->lock);
298 
299 		/* Copy in CAIF frame. */
300 		skb_copy_bits(skb, 0, pfrm, skb->len);
301 
302 		/* Update payload length. */
303 		pld_len += desc->cffrm_len[nfrms];
304 
305 		/* Update frame pointer. */
306 		pfrm += skb->len + tpad;
307 
308 		/* Consume the SKB */
309 		consume_skb(skb);
310 		skb = NULL;
311 
312 		/* Update number of frames. */
313 		nfrms++;
314 	}
315 
316 	/* Unused length fields should be zero-filled (according to SPEC). */
317 	while (nfrms < CFHSI_MAX_PKTS) {
318 		desc->cffrm_len[nfrms] = 0x0000;
319 		nfrms++;
320 	}
321 
322 	/* Check if we can piggy-back another descriptor. */
323 	if (cfhsi_can_send_aggregate(cfhsi))
324 		desc->header |= CFHSI_PIGGY_DESC;
325 	else
326 		desc->header &= ~CFHSI_PIGGY_DESC;
327 
328 	return CFHSI_DESC_SZ + pld_len;
329 }
330 
cfhsi_start_tx(struct cfhsi * cfhsi)331 static void cfhsi_start_tx(struct cfhsi *cfhsi)
332 {
333 	struct cfhsi_desc *desc = (struct cfhsi_desc *)cfhsi->tx_buf;
334 	int len, res;
335 
336 	netdev_dbg(cfhsi->ndev, "%s.\n", __func__);
337 
338 	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
339 		return;
340 
341 	do {
342 		/* Create HSI frame. */
343 		len = cfhsi_tx_frm(desc, cfhsi);
344 		if (!len) {
345 			spin_lock_bh(&cfhsi->lock);
346 			if (unlikely(cfhsi_tx_queue_len(cfhsi))) {
347 				spin_unlock_bh(&cfhsi->lock);
348 				res = -EAGAIN;
349 				continue;
350 			}
351 			cfhsi->tx_state = CFHSI_TX_STATE_IDLE;
352 			/* Start inactivity timer. */
353 			mod_timer(&cfhsi->inactivity_timer,
354 				jiffies + cfhsi->cfg.inactivity_timeout);
355 			spin_unlock_bh(&cfhsi->lock);
356 			break;
357 		}
358 
359 		/* Set up new transfer. */
360 		res = cfhsi->ops->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->ops);
361 		if (WARN_ON(res < 0))
362 			netdev_err(cfhsi->ndev, "%s: TX error %d.\n",
363 				__func__, res);
364 	} while (res < 0);
365 }
366 
cfhsi_tx_done(struct cfhsi * cfhsi)367 static void cfhsi_tx_done(struct cfhsi *cfhsi)
368 {
369 	netdev_dbg(cfhsi->ndev, "%s.\n", __func__);
370 
371 	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
372 		return;
373 
374 	/*
375 	 * Send flow on if flow off has been previously signalled
376 	 * and number of packets is below low water mark.
377 	 */
378 	spin_lock_bh(&cfhsi->lock);
379 	if (cfhsi->flow_off_sent &&
380 			cfhsi_tx_queue_len(cfhsi) <= cfhsi->cfg.q_low_mark &&
381 			cfhsi->cfdev.flowctrl) {
382 
383 		cfhsi->flow_off_sent = 0;
384 		cfhsi->cfdev.flowctrl(cfhsi->ndev, ON);
385 	}
386 
387 	if (cfhsi_can_send_aggregate(cfhsi)) {
388 		spin_unlock_bh(&cfhsi->lock);
389 		cfhsi_start_tx(cfhsi);
390 	} else {
391 		mod_timer(&cfhsi->aggregation_timer,
392 			jiffies + cfhsi->cfg.aggregation_timeout);
393 		spin_unlock_bh(&cfhsi->lock);
394 	}
395 
396 	return;
397 }
398 
cfhsi_tx_done_cb(struct cfhsi_cb_ops * cb_ops)399 static void cfhsi_tx_done_cb(struct cfhsi_cb_ops *cb_ops)
400 {
401 	struct cfhsi *cfhsi;
402 
403 	cfhsi = container_of(cb_ops, struct cfhsi, cb_ops);
404 	netdev_dbg(cfhsi->ndev, "%s.\n",
405 		__func__);
406 
407 	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
408 		return;
409 	cfhsi_tx_done(cfhsi);
410 }
411 
cfhsi_rx_desc(struct cfhsi_desc * desc,struct cfhsi * cfhsi)412 static int cfhsi_rx_desc(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
413 {
414 	int xfer_sz = 0;
415 	int nfrms = 0;
416 	u16 *plen = NULL;
417 	u8 *pfrm = NULL;
418 
419 	if ((desc->header & ~CFHSI_PIGGY_DESC) ||
420 			(desc->offset > CFHSI_MAX_EMB_FRM_SZ)) {
421 		netdev_err(cfhsi->ndev, "%s: Invalid descriptor.\n",
422 			__func__);
423 		return -EPROTO;
424 	}
425 
426 	/* Check for embedded CAIF frame. */
427 	if (desc->offset) {
428 		struct sk_buff *skb;
429 		u8 *dst = NULL;
430 		int len = 0;
431 		pfrm = ((u8 *)desc) + desc->offset;
432 
433 		/* Remove offset padding. */
434 		pfrm += *pfrm + 1;
435 
436 		/* Read length of CAIF frame (little endian). */
437 		len = *pfrm;
438 		len |= ((*(pfrm+1)) << 8) & 0xFF00;
439 		len += 2;	/* Add FCS fields. */
440 
441 		/* Sanity check length of CAIF frame. */
442 		if (unlikely(len > CFHSI_MAX_CAIF_FRAME_SZ)) {
443 			netdev_err(cfhsi->ndev, "%s: Invalid length.\n",
444 				__func__);
445 			return -EPROTO;
446 		}
447 
448 		/* Allocate SKB (OK even in IRQ context). */
449 		skb = alloc_skb(len + 1, GFP_ATOMIC);
450 		if (!skb) {
451 			netdev_err(cfhsi->ndev, "%s: Out of memory !\n",
452 				__func__);
453 			return -ENOMEM;
454 		}
455 		caif_assert(skb != NULL);
456 
457 		dst = skb_put(skb, len);
458 		memcpy(dst, pfrm, len);
459 
460 		skb->protocol = htons(ETH_P_CAIF);
461 		skb_reset_mac_header(skb);
462 		skb->dev = cfhsi->ndev;
463 
464 		/*
465 		 * We are in a callback handler and
466 		 * unfortunately we don't know what context we're
467 		 * running in.
468 		 */
469 		if (in_interrupt())
470 			netif_rx(skb);
471 		else
472 			netif_rx_ni(skb);
473 
474 		/* Update network statistics. */
475 		cfhsi->ndev->stats.rx_packets++;
476 		cfhsi->ndev->stats.rx_bytes += len;
477 	}
478 
479 	/* Calculate transfer length. */
480 	plen = desc->cffrm_len;
481 	while (nfrms < CFHSI_MAX_PKTS && *plen) {
482 		xfer_sz += *plen;
483 		plen++;
484 		nfrms++;
485 	}
486 
487 	/* Check for piggy-backed descriptor. */
488 	if (desc->header & CFHSI_PIGGY_DESC)
489 		xfer_sz += CFHSI_DESC_SZ;
490 
491 	if ((xfer_sz % 4) || (xfer_sz > (CFHSI_BUF_SZ_RX - CFHSI_DESC_SZ))) {
492 		netdev_err(cfhsi->ndev,
493 				"%s: Invalid payload len: %d, ignored.\n",
494 			__func__, xfer_sz);
495 		return -EPROTO;
496 	}
497 	return xfer_sz;
498 }
499 
cfhsi_rx_desc_len(struct cfhsi_desc * desc)500 static int cfhsi_rx_desc_len(struct cfhsi_desc *desc)
501 {
502 	int xfer_sz = 0;
503 	int nfrms = 0;
504 	u16 *plen;
505 
506 	if ((desc->header & ~CFHSI_PIGGY_DESC) ||
507 			(desc->offset > CFHSI_MAX_EMB_FRM_SZ)) {
508 
509 		pr_err("Invalid descriptor. %x %x\n", desc->header,
510 				desc->offset);
511 		return -EPROTO;
512 	}
513 
514 	/* Calculate transfer length. */
515 	plen = desc->cffrm_len;
516 	while (nfrms < CFHSI_MAX_PKTS && *plen) {
517 		xfer_sz += *plen;
518 		plen++;
519 		nfrms++;
520 	}
521 
522 	if (xfer_sz % 4) {
523 		pr_err("Invalid payload len: %d, ignored.\n", xfer_sz);
524 		return -EPROTO;
525 	}
526 	return xfer_sz;
527 }
528 
cfhsi_rx_pld(struct cfhsi_desc * desc,struct cfhsi * cfhsi)529 static int cfhsi_rx_pld(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
530 {
531 	int rx_sz = 0;
532 	int nfrms = 0;
533 	u16 *plen = NULL;
534 	u8 *pfrm = NULL;
535 
536 	/* Sanity check header and offset. */
537 	if (WARN_ON((desc->header & ~CFHSI_PIGGY_DESC) ||
538 			(desc->offset > CFHSI_MAX_EMB_FRM_SZ))) {
539 		netdev_err(cfhsi->ndev, "%s: Invalid descriptor.\n",
540 			__func__);
541 		return -EPROTO;
542 	}
543 
544 	/* Set frame pointer to start of payload. */
545 	pfrm = desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ;
546 	plen = desc->cffrm_len;
547 
548 	/* Skip already processed frames. */
549 	while (nfrms < cfhsi->rx_state.nfrms) {
550 		pfrm += *plen;
551 		rx_sz += *plen;
552 		plen++;
553 		nfrms++;
554 	}
555 
556 	/* Parse payload. */
557 	while (nfrms < CFHSI_MAX_PKTS && *plen) {
558 		struct sk_buff *skb;
559 		u8 *dst = NULL;
560 		u8 *pcffrm = NULL;
561 		int len;
562 
563 		/* CAIF frame starts after head padding. */
564 		pcffrm = pfrm + *pfrm + 1;
565 
566 		/* Read length of CAIF frame (little endian). */
567 		len = *pcffrm;
568 		len |= ((*(pcffrm + 1)) << 8) & 0xFF00;
569 		len += 2;	/* Add FCS fields. */
570 
571 		/* Sanity check length of CAIF frames. */
572 		if (unlikely(len > CFHSI_MAX_CAIF_FRAME_SZ)) {
573 			netdev_err(cfhsi->ndev, "%s: Invalid length.\n",
574 				__func__);
575 			return -EPROTO;
576 		}
577 
578 		/* Allocate SKB (OK even in IRQ context). */
579 		skb = alloc_skb(len + 1, GFP_ATOMIC);
580 		if (!skb) {
581 			netdev_err(cfhsi->ndev, "%s: Out of memory !\n",
582 				__func__);
583 			cfhsi->rx_state.nfrms = nfrms;
584 			return -ENOMEM;
585 		}
586 		caif_assert(skb != NULL);
587 
588 		dst = skb_put(skb, len);
589 		memcpy(dst, pcffrm, len);
590 
591 		skb->protocol = htons(ETH_P_CAIF);
592 		skb_reset_mac_header(skb);
593 		skb->dev = cfhsi->ndev;
594 
595 		/*
596 		 * We're called in callback from HSI
597 		 * and don't know the context we're running in.
598 		 */
599 		if (in_interrupt())
600 			netif_rx(skb);
601 		else
602 			netif_rx_ni(skb);
603 
604 		/* Update network statistics. */
605 		cfhsi->ndev->stats.rx_packets++;
606 		cfhsi->ndev->stats.rx_bytes += len;
607 
608 		pfrm += *plen;
609 		rx_sz += *plen;
610 		plen++;
611 		nfrms++;
612 	}
613 
614 	return rx_sz;
615 }
616 
cfhsi_rx_done(struct cfhsi * cfhsi)617 static void cfhsi_rx_done(struct cfhsi *cfhsi)
618 {
619 	int res;
620 	int desc_pld_len = 0, rx_len, rx_state;
621 	struct cfhsi_desc *desc = NULL;
622 	u8 *rx_ptr, *rx_buf;
623 	struct cfhsi_desc *piggy_desc = NULL;
624 
625 	desc = (struct cfhsi_desc *)cfhsi->rx_buf;
626 
627 	netdev_dbg(cfhsi->ndev, "%s\n", __func__);
628 
629 	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
630 		return;
631 
632 	/* Update inactivity timer if pending. */
633 	spin_lock_bh(&cfhsi->lock);
634 	mod_timer_pending(&cfhsi->inactivity_timer,
635 			jiffies + cfhsi->cfg.inactivity_timeout);
636 	spin_unlock_bh(&cfhsi->lock);
637 
638 	if (cfhsi->rx_state.state == CFHSI_RX_STATE_DESC) {
639 		desc_pld_len = cfhsi_rx_desc_len(desc);
640 
641 		if (desc_pld_len < 0)
642 			goto out_of_sync;
643 
644 		rx_buf = cfhsi->rx_buf;
645 		rx_len = desc_pld_len;
646 		if (desc_pld_len > 0 && (desc->header & CFHSI_PIGGY_DESC))
647 			rx_len += CFHSI_DESC_SZ;
648 		if (desc_pld_len == 0)
649 			rx_buf = cfhsi->rx_flip_buf;
650 	} else {
651 		rx_buf = cfhsi->rx_flip_buf;
652 
653 		rx_len = CFHSI_DESC_SZ;
654 		if (cfhsi->rx_state.pld_len > 0 &&
655 				(desc->header & CFHSI_PIGGY_DESC)) {
656 
657 			piggy_desc = (struct cfhsi_desc *)
658 				(desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ +
659 						cfhsi->rx_state.pld_len);
660 
661 			cfhsi->rx_state.piggy_desc = true;
662 
663 			/* Extract payload len from piggy-backed descriptor. */
664 			desc_pld_len = cfhsi_rx_desc_len(piggy_desc);
665 			if (desc_pld_len < 0)
666 				goto out_of_sync;
667 
668 			if (desc_pld_len > 0) {
669 				rx_len = desc_pld_len;
670 				if (piggy_desc->header & CFHSI_PIGGY_DESC)
671 					rx_len += CFHSI_DESC_SZ;
672 			}
673 
674 			/*
675 			 * Copy needed information from the piggy-backed
676 			 * descriptor to the descriptor in the start.
677 			 */
678 			memcpy(rx_buf, (u8 *)piggy_desc,
679 					CFHSI_DESC_SHORT_SZ);
680 		}
681 	}
682 
683 	if (desc_pld_len) {
684 		rx_state = CFHSI_RX_STATE_PAYLOAD;
685 		rx_ptr = rx_buf + CFHSI_DESC_SZ;
686 	} else {
687 		rx_state = CFHSI_RX_STATE_DESC;
688 		rx_ptr = rx_buf;
689 		rx_len = CFHSI_DESC_SZ;
690 	}
691 
692 	/* Initiate next read */
693 	if (test_bit(CFHSI_AWAKE, &cfhsi->bits)) {
694 		/* Set up new transfer. */
695 		netdev_dbg(cfhsi->ndev, "%s: Start RX.\n",
696 				__func__);
697 
698 		res = cfhsi->ops->cfhsi_rx(rx_ptr, rx_len,
699 				cfhsi->ops);
700 		if (WARN_ON(res < 0)) {
701 			netdev_err(cfhsi->ndev, "%s: RX error %d.\n",
702 				__func__, res);
703 			cfhsi->ndev->stats.rx_errors++;
704 			cfhsi->ndev->stats.rx_dropped++;
705 		}
706 	}
707 
708 	if (cfhsi->rx_state.state == CFHSI_RX_STATE_DESC) {
709 		/* Extract payload from descriptor */
710 		if (cfhsi_rx_desc(desc, cfhsi) < 0)
711 			goto out_of_sync;
712 	} else {
713 		/* Extract payload */
714 		if (cfhsi_rx_pld(desc, cfhsi) < 0)
715 			goto out_of_sync;
716 		if (piggy_desc) {
717 			/* Extract any payload in piggyback descriptor. */
718 			if (cfhsi_rx_desc(piggy_desc, cfhsi) < 0)
719 				goto out_of_sync;
720 			/* Mark no embedded frame after extracting it */
721 			piggy_desc->offset = 0;
722 		}
723 	}
724 
725 	/* Update state info */
726 	memset(&cfhsi->rx_state, 0, sizeof(cfhsi->rx_state));
727 	cfhsi->rx_state.state = rx_state;
728 	cfhsi->rx_ptr = rx_ptr;
729 	cfhsi->rx_len = rx_len;
730 	cfhsi->rx_state.pld_len = desc_pld_len;
731 	cfhsi->rx_state.piggy_desc = desc->header & CFHSI_PIGGY_DESC;
732 
733 	if (rx_buf != cfhsi->rx_buf)
734 		swap(cfhsi->rx_buf, cfhsi->rx_flip_buf);
735 	return;
736 
737 out_of_sync:
738 	netdev_err(cfhsi->ndev, "%s: Out of sync.\n", __func__);
739 	print_hex_dump_bytes("--> ", DUMP_PREFIX_NONE,
740 			cfhsi->rx_buf, CFHSI_DESC_SZ);
741 	schedule_work(&cfhsi->out_of_sync_work);
742 }
743 
cfhsi_rx_slowpath(unsigned long arg)744 static void cfhsi_rx_slowpath(unsigned long arg)
745 {
746 	struct cfhsi *cfhsi = (struct cfhsi *)arg;
747 
748 	netdev_dbg(cfhsi->ndev, "%s.\n",
749 		__func__);
750 
751 	cfhsi_rx_done(cfhsi);
752 }
753 
cfhsi_rx_done_cb(struct cfhsi_cb_ops * cb_ops)754 static void cfhsi_rx_done_cb(struct cfhsi_cb_ops *cb_ops)
755 {
756 	struct cfhsi *cfhsi;
757 
758 	cfhsi = container_of(cb_ops, struct cfhsi, cb_ops);
759 	netdev_dbg(cfhsi->ndev, "%s.\n",
760 		__func__);
761 
762 	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
763 		return;
764 
765 	if (test_and_clear_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits))
766 		wake_up_interruptible(&cfhsi->flush_fifo_wait);
767 	else
768 		cfhsi_rx_done(cfhsi);
769 }
770 
cfhsi_wake_up(struct work_struct * work)771 static void cfhsi_wake_up(struct work_struct *work)
772 {
773 	struct cfhsi *cfhsi = NULL;
774 	int res;
775 	int len;
776 	long ret;
777 
778 	cfhsi = container_of(work, struct cfhsi, wake_up_work);
779 
780 	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
781 		return;
782 
783 	if (unlikely(test_bit(CFHSI_AWAKE, &cfhsi->bits))) {
784 		/* It happenes when wakeup is requested by
785 		 * both ends at the same time. */
786 		clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
787 		clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
788 		return;
789 	}
790 
791 	/* Activate wake line. */
792 	cfhsi->ops->cfhsi_wake_up(cfhsi->ops);
793 
794 	netdev_dbg(cfhsi->ndev, "%s: Start waiting.\n",
795 		__func__);
796 
797 	/* Wait for acknowledge. */
798 	ret = CFHSI_WAKE_TOUT;
799 	ret = wait_event_interruptible_timeout(cfhsi->wake_up_wait,
800 					test_and_clear_bit(CFHSI_WAKE_UP_ACK,
801 							&cfhsi->bits), ret);
802 	if (unlikely(ret < 0)) {
803 		/* Interrupted by signal. */
804 		netdev_err(cfhsi->ndev, "%s: Signalled: %ld.\n",
805 			__func__, ret);
806 
807 		clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
808 		cfhsi->ops->cfhsi_wake_down(cfhsi->ops);
809 		return;
810 	} else if (!ret) {
811 		bool ca_wake = false;
812 		size_t fifo_occupancy = 0;
813 
814 		/* Wakeup timeout */
815 		netdev_dbg(cfhsi->ndev, "%s: Timeout.\n",
816 			__func__);
817 
818 		/* Check FIFO to check if modem has sent something. */
819 		WARN_ON(cfhsi->ops->cfhsi_fifo_occupancy(cfhsi->ops,
820 					&fifo_occupancy));
821 
822 		netdev_dbg(cfhsi->ndev, "%s: Bytes in FIFO: %u.\n",
823 				__func__, (unsigned) fifo_occupancy);
824 
825 		/* Check if we misssed the interrupt. */
826 		WARN_ON(cfhsi->ops->cfhsi_get_peer_wake(cfhsi->ops,
827 							&ca_wake));
828 
829 		if (ca_wake) {
830 			netdev_err(cfhsi->ndev, "%s: CA Wake missed !.\n",
831 				__func__);
832 
833 			/* Clear the CFHSI_WAKE_UP_ACK bit to prevent race. */
834 			clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
835 
836 			/* Continue execution. */
837 			goto wake_ack;
838 		}
839 
840 		clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
841 		cfhsi->ops->cfhsi_wake_down(cfhsi->ops);
842 		return;
843 	}
844 wake_ack:
845 	netdev_dbg(cfhsi->ndev, "%s: Woken.\n",
846 		__func__);
847 
848 	/* Clear power up bit. */
849 	set_bit(CFHSI_AWAKE, &cfhsi->bits);
850 	clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
851 
852 	/* Resume read operation. */
853 	netdev_dbg(cfhsi->ndev, "%s: Start RX.\n", __func__);
854 	res = cfhsi->ops->cfhsi_rx(cfhsi->rx_ptr, cfhsi->rx_len, cfhsi->ops);
855 
856 	if (WARN_ON(res < 0))
857 		netdev_err(cfhsi->ndev, "%s: RX err %d.\n", __func__, res);
858 
859 	/* Clear power up acknowledment. */
860 	clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
861 
862 	spin_lock_bh(&cfhsi->lock);
863 
864 	/* Resume transmit if queues are not empty. */
865 	if (!cfhsi_tx_queue_len(cfhsi)) {
866 		netdev_dbg(cfhsi->ndev, "%s: Peer wake, start timer.\n",
867 			__func__);
868 		/* Start inactivity timer. */
869 		mod_timer(&cfhsi->inactivity_timer,
870 				jiffies + cfhsi->cfg.inactivity_timeout);
871 		spin_unlock_bh(&cfhsi->lock);
872 		return;
873 	}
874 
875 	netdev_dbg(cfhsi->ndev, "%s: Host wake.\n",
876 		__func__);
877 
878 	spin_unlock_bh(&cfhsi->lock);
879 
880 	/* Create HSI frame. */
881 	len = cfhsi_tx_frm((struct cfhsi_desc *)cfhsi->tx_buf, cfhsi);
882 
883 	if (likely(len > 0)) {
884 		/* Set up new transfer. */
885 		res = cfhsi->ops->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->ops);
886 		if (WARN_ON(res < 0)) {
887 			netdev_err(cfhsi->ndev, "%s: TX error %d.\n",
888 				__func__, res);
889 			cfhsi_abort_tx(cfhsi);
890 		}
891 	} else {
892 		netdev_err(cfhsi->ndev,
893 				"%s: Failed to create HSI frame: %d.\n",
894 				__func__, len);
895 	}
896 }
897 
cfhsi_wake_down(struct work_struct * work)898 static void cfhsi_wake_down(struct work_struct *work)
899 {
900 	long ret;
901 	struct cfhsi *cfhsi = NULL;
902 	size_t fifo_occupancy = 0;
903 	int retry = CFHSI_WAKE_TOUT;
904 
905 	cfhsi = container_of(work, struct cfhsi, wake_down_work);
906 	netdev_dbg(cfhsi->ndev, "%s.\n", __func__);
907 
908 	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
909 		return;
910 
911 	/* Deactivate wake line. */
912 	cfhsi->ops->cfhsi_wake_down(cfhsi->ops);
913 
914 	/* Wait for acknowledge. */
915 	ret = CFHSI_WAKE_TOUT;
916 	ret = wait_event_interruptible_timeout(cfhsi->wake_down_wait,
917 					test_and_clear_bit(CFHSI_WAKE_DOWN_ACK,
918 							&cfhsi->bits), ret);
919 	if (ret < 0) {
920 		/* Interrupted by signal. */
921 		netdev_err(cfhsi->ndev, "%s: Signalled: %ld.\n",
922 			__func__, ret);
923 		return;
924 	} else if (!ret) {
925 		bool ca_wake = true;
926 
927 		/* Timeout */
928 		netdev_err(cfhsi->ndev, "%s: Timeout.\n", __func__);
929 
930 		/* Check if we misssed the interrupt. */
931 		WARN_ON(cfhsi->ops->cfhsi_get_peer_wake(cfhsi->ops,
932 							&ca_wake));
933 		if (!ca_wake)
934 			netdev_err(cfhsi->ndev, "%s: CA Wake missed !.\n",
935 				__func__);
936 	}
937 
938 	/* Check FIFO occupancy. */
939 	while (retry) {
940 		WARN_ON(cfhsi->ops->cfhsi_fifo_occupancy(cfhsi->ops,
941 							&fifo_occupancy));
942 
943 		if (!fifo_occupancy)
944 			break;
945 
946 		set_current_state(TASK_INTERRUPTIBLE);
947 		schedule_timeout(1);
948 		retry--;
949 	}
950 
951 	if (!retry)
952 		netdev_err(cfhsi->ndev, "%s: FIFO Timeout.\n", __func__);
953 
954 	/* Clear AWAKE condition. */
955 	clear_bit(CFHSI_AWAKE, &cfhsi->bits);
956 
957 	/* Cancel pending RX requests. */
958 	cfhsi->ops->cfhsi_rx_cancel(cfhsi->ops);
959 }
960 
cfhsi_out_of_sync(struct work_struct * work)961 static void cfhsi_out_of_sync(struct work_struct *work)
962 {
963 	struct cfhsi *cfhsi = NULL;
964 
965 	cfhsi = container_of(work, struct cfhsi, out_of_sync_work);
966 
967 	rtnl_lock();
968 	dev_close(cfhsi->ndev);
969 	rtnl_unlock();
970 }
971 
cfhsi_wake_up_cb(struct cfhsi_cb_ops * cb_ops)972 static void cfhsi_wake_up_cb(struct cfhsi_cb_ops *cb_ops)
973 {
974 	struct cfhsi *cfhsi = NULL;
975 
976 	cfhsi = container_of(cb_ops, struct cfhsi, cb_ops);
977 	netdev_dbg(cfhsi->ndev, "%s.\n",
978 		__func__);
979 
980 	set_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
981 	wake_up_interruptible(&cfhsi->wake_up_wait);
982 
983 	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
984 		return;
985 
986 	/* Schedule wake up work queue if the peer initiates. */
987 	if (!test_and_set_bit(CFHSI_WAKE_UP, &cfhsi->bits))
988 		queue_work(cfhsi->wq, &cfhsi->wake_up_work);
989 }
990 
cfhsi_wake_down_cb(struct cfhsi_cb_ops * cb_ops)991 static void cfhsi_wake_down_cb(struct cfhsi_cb_ops *cb_ops)
992 {
993 	struct cfhsi *cfhsi = NULL;
994 
995 	cfhsi = container_of(cb_ops, struct cfhsi, cb_ops);
996 	netdev_dbg(cfhsi->ndev, "%s.\n",
997 		__func__);
998 
999 	/* Initiating low power is only permitted by the host (us). */
1000 	set_bit(CFHSI_WAKE_DOWN_ACK, &cfhsi->bits);
1001 	wake_up_interruptible(&cfhsi->wake_down_wait);
1002 }
1003 
cfhsi_aggregation_tout(unsigned long arg)1004 static void cfhsi_aggregation_tout(unsigned long arg)
1005 {
1006 	struct cfhsi *cfhsi = (struct cfhsi *)arg;
1007 
1008 	netdev_dbg(cfhsi->ndev, "%s.\n",
1009 		__func__);
1010 
1011 	cfhsi_start_tx(cfhsi);
1012 }
1013 
cfhsi_xmit(struct sk_buff * skb,struct net_device * dev)1014 static int cfhsi_xmit(struct sk_buff *skb, struct net_device *dev)
1015 {
1016 	struct cfhsi *cfhsi = NULL;
1017 	int start_xfer = 0;
1018 	int timer_active;
1019 	int prio;
1020 
1021 	if (!dev)
1022 		return -EINVAL;
1023 
1024 	cfhsi = netdev_priv(dev);
1025 
1026 	switch (skb->priority) {
1027 	case TC_PRIO_BESTEFFORT:
1028 	case TC_PRIO_FILLER:
1029 	case TC_PRIO_BULK:
1030 		prio = CFHSI_PRIO_BEBK;
1031 		break;
1032 	case TC_PRIO_INTERACTIVE_BULK:
1033 		prio = CFHSI_PRIO_VI;
1034 		break;
1035 	case TC_PRIO_INTERACTIVE:
1036 		prio = CFHSI_PRIO_VO;
1037 		break;
1038 	case TC_PRIO_CONTROL:
1039 	default:
1040 		prio = CFHSI_PRIO_CTL;
1041 		break;
1042 	}
1043 
1044 	spin_lock_bh(&cfhsi->lock);
1045 
1046 	/* Update aggregation statistics  */
1047 	cfhsi_update_aggregation_stats(cfhsi, skb, 1);
1048 
1049 	/* Queue the SKB */
1050 	skb_queue_tail(&cfhsi->qhead[prio], skb);
1051 
1052 	/* Sanity check; xmit should not be called after unregister_netdev */
1053 	if (WARN_ON(test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))) {
1054 		spin_unlock_bh(&cfhsi->lock);
1055 		cfhsi_abort_tx(cfhsi);
1056 		return -EINVAL;
1057 	}
1058 
1059 	/* Send flow off if number of packets is above high water mark. */
1060 	if (!cfhsi->flow_off_sent &&
1061 		cfhsi_tx_queue_len(cfhsi) > cfhsi->cfg.q_high_mark &&
1062 		cfhsi->cfdev.flowctrl) {
1063 		cfhsi->flow_off_sent = 1;
1064 		cfhsi->cfdev.flowctrl(cfhsi->ndev, OFF);
1065 	}
1066 
1067 	if (cfhsi->tx_state == CFHSI_TX_STATE_IDLE) {
1068 		cfhsi->tx_state = CFHSI_TX_STATE_XFER;
1069 		start_xfer = 1;
1070 	}
1071 
1072 	if (!start_xfer) {
1073 		/* Send aggregate if it is possible */
1074 		bool aggregate_ready =
1075 			cfhsi_can_send_aggregate(cfhsi) &&
1076 			del_timer(&cfhsi->aggregation_timer) > 0;
1077 		spin_unlock_bh(&cfhsi->lock);
1078 		if (aggregate_ready)
1079 			cfhsi_start_tx(cfhsi);
1080 		return 0;
1081 	}
1082 
1083 	/* Delete inactivity timer if started. */
1084 	timer_active = del_timer_sync(&cfhsi->inactivity_timer);
1085 
1086 	spin_unlock_bh(&cfhsi->lock);
1087 
1088 	if (timer_active) {
1089 		struct cfhsi_desc *desc = (struct cfhsi_desc *)cfhsi->tx_buf;
1090 		int len;
1091 		int res;
1092 
1093 		/* Create HSI frame. */
1094 		len = cfhsi_tx_frm(desc, cfhsi);
1095 		WARN_ON(!len);
1096 
1097 		/* Set up new transfer. */
1098 		res = cfhsi->ops->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->ops);
1099 		if (WARN_ON(res < 0)) {
1100 			netdev_err(cfhsi->ndev, "%s: TX error %d.\n",
1101 				__func__, res);
1102 			cfhsi_abort_tx(cfhsi);
1103 		}
1104 	} else {
1105 		/* Schedule wake up work queue if the we initiate. */
1106 		if (!test_and_set_bit(CFHSI_WAKE_UP, &cfhsi->bits))
1107 			queue_work(cfhsi->wq, &cfhsi->wake_up_work);
1108 	}
1109 
1110 	return 0;
1111 }
1112 
1113 static const struct net_device_ops cfhsi_netdevops;
1114 
cfhsi_setup(struct net_device * dev)1115 static void cfhsi_setup(struct net_device *dev)
1116 {
1117 	int i;
1118 	struct cfhsi *cfhsi = netdev_priv(dev);
1119 	dev->features = 0;
1120 	dev->type = ARPHRD_CAIF;
1121 	dev->flags = IFF_POINTOPOINT | IFF_NOARP;
1122 	dev->mtu = CFHSI_MAX_CAIF_FRAME_SZ;
1123 	dev->tx_queue_len = 0;
1124 	dev->destructor = free_netdev;
1125 	dev->netdev_ops = &cfhsi_netdevops;
1126 	for (i = 0; i < CFHSI_PRIO_LAST; ++i)
1127 		skb_queue_head_init(&cfhsi->qhead[i]);
1128 	cfhsi->cfdev.link_select = CAIF_LINK_HIGH_BANDW;
1129 	cfhsi->cfdev.use_frag = false;
1130 	cfhsi->cfdev.use_stx = false;
1131 	cfhsi->cfdev.use_fcs = false;
1132 	cfhsi->ndev = dev;
1133 	cfhsi->cfg = hsi_default_config;
1134 }
1135 
cfhsi_open(struct net_device * ndev)1136 static int cfhsi_open(struct net_device *ndev)
1137 {
1138 	struct cfhsi *cfhsi = netdev_priv(ndev);
1139 	int res;
1140 
1141 	clear_bit(CFHSI_SHUTDOWN, &cfhsi->bits);
1142 
1143 	/* Initialize state vaiables. */
1144 	cfhsi->tx_state = CFHSI_TX_STATE_IDLE;
1145 	cfhsi->rx_state.state = CFHSI_RX_STATE_DESC;
1146 
1147 	/* Set flow info */
1148 	cfhsi->flow_off_sent = 0;
1149 
1150 	/*
1151 	 * Allocate a TX buffer with the size of a HSI packet descriptors
1152 	 * and the necessary room for CAIF payload frames.
1153 	 */
1154 	cfhsi->tx_buf = kzalloc(CFHSI_BUF_SZ_TX, GFP_KERNEL);
1155 	if (!cfhsi->tx_buf) {
1156 		res = -ENODEV;
1157 		goto err_alloc_tx;
1158 	}
1159 
1160 	/*
1161 	 * Allocate a RX buffer with the size of two HSI packet descriptors and
1162 	 * the necessary room for CAIF payload frames.
1163 	 */
1164 	cfhsi->rx_buf = kzalloc(CFHSI_BUF_SZ_RX, GFP_KERNEL);
1165 	if (!cfhsi->rx_buf) {
1166 		res = -ENODEV;
1167 		goto err_alloc_rx;
1168 	}
1169 
1170 	cfhsi->rx_flip_buf = kzalloc(CFHSI_BUF_SZ_RX, GFP_KERNEL);
1171 	if (!cfhsi->rx_flip_buf) {
1172 		res = -ENODEV;
1173 		goto err_alloc_rx_flip;
1174 	}
1175 
1176 	/* Initialize aggregation timeout */
1177 	cfhsi->cfg.aggregation_timeout = hsi_default_config.aggregation_timeout;
1178 
1179 	/* Initialize recieve vaiables. */
1180 	cfhsi->rx_ptr = cfhsi->rx_buf;
1181 	cfhsi->rx_len = CFHSI_DESC_SZ;
1182 
1183 	/* Initialize spin locks. */
1184 	spin_lock_init(&cfhsi->lock);
1185 
1186 	/* Set up the driver. */
1187 	cfhsi->cb_ops.tx_done_cb = cfhsi_tx_done_cb;
1188 	cfhsi->cb_ops.rx_done_cb = cfhsi_rx_done_cb;
1189 	cfhsi->cb_ops.wake_up_cb = cfhsi_wake_up_cb;
1190 	cfhsi->cb_ops.wake_down_cb = cfhsi_wake_down_cb;
1191 
1192 	/* Initialize the work queues. */
1193 	INIT_WORK(&cfhsi->wake_up_work, cfhsi_wake_up);
1194 	INIT_WORK(&cfhsi->wake_down_work, cfhsi_wake_down);
1195 	INIT_WORK(&cfhsi->out_of_sync_work, cfhsi_out_of_sync);
1196 
1197 	/* Clear all bit fields. */
1198 	clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
1199 	clear_bit(CFHSI_WAKE_DOWN_ACK, &cfhsi->bits);
1200 	clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
1201 	clear_bit(CFHSI_AWAKE, &cfhsi->bits);
1202 
1203 	/* Create work thread. */
1204 	cfhsi->wq = create_singlethread_workqueue(cfhsi->ndev->name);
1205 	if (!cfhsi->wq) {
1206 		netdev_err(cfhsi->ndev, "%s: Failed to create work queue.\n",
1207 			__func__);
1208 		res = -ENODEV;
1209 		goto err_create_wq;
1210 	}
1211 
1212 	/* Initialize wait queues. */
1213 	init_waitqueue_head(&cfhsi->wake_up_wait);
1214 	init_waitqueue_head(&cfhsi->wake_down_wait);
1215 	init_waitqueue_head(&cfhsi->flush_fifo_wait);
1216 
1217 	/* Setup the inactivity timer. */
1218 	init_timer(&cfhsi->inactivity_timer);
1219 	cfhsi->inactivity_timer.data = (unsigned long)cfhsi;
1220 	cfhsi->inactivity_timer.function = cfhsi_inactivity_tout;
1221 	/* Setup the slowpath RX timer. */
1222 	init_timer(&cfhsi->rx_slowpath_timer);
1223 	cfhsi->rx_slowpath_timer.data = (unsigned long)cfhsi;
1224 	cfhsi->rx_slowpath_timer.function = cfhsi_rx_slowpath;
1225 	/* Setup the aggregation timer. */
1226 	init_timer(&cfhsi->aggregation_timer);
1227 	cfhsi->aggregation_timer.data = (unsigned long)cfhsi;
1228 	cfhsi->aggregation_timer.function = cfhsi_aggregation_tout;
1229 
1230 	/* Activate HSI interface. */
1231 	res = cfhsi->ops->cfhsi_up(cfhsi->ops);
1232 	if (res) {
1233 		netdev_err(cfhsi->ndev,
1234 			"%s: can't activate HSI interface: %d.\n",
1235 			__func__, res);
1236 		goto err_activate;
1237 	}
1238 
1239 	/* Flush FIFO */
1240 	res = cfhsi_flush_fifo(cfhsi);
1241 	if (res) {
1242 		netdev_err(cfhsi->ndev, "%s: Can't flush FIFO: %d.\n",
1243 			__func__, res);
1244 		goto err_net_reg;
1245 	}
1246 	return res;
1247 
1248  err_net_reg:
1249 	cfhsi->ops->cfhsi_down(cfhsi->ops);
1250  err_activate:
1251 	destroy_workqueue(cfhsi->wq);
1252  err_create_wq:
1253 	kfree(cfhsi->rx_flip_buf);
1254  err_alloc_rx_flip:
1255 	kfree(cfhsi->rx_buf);
1256  err_alloc_rx:
1257 	kfree(cfhsi->tx_buf);
1258  err_alloc_tx:
1259 	return res;
1260 }
1261 
cfhsi_close(struct net_device * ndev)1262 static int cfhsi_close(struct net_device *ndev)
1263 {
1264 	struct cfhsi *cfhsi = netdev_priv(ndev);
1265 	u8 *tx_buf, *rx_buf, *flip_buf;
1266 
1267 	/* going to shutdown driver */
1268 	set_bit(CFHSI_SHUTDOWN, &cfhsi->bits);
1269 
1270 	/* Flush workqueue */
1271 	flush_workqueue(cfhsi->wq);
1272 
1273 	/* Delete timers if pending */
1274 	del_timer_sync(&cfhsi->inactivity_timer);
1275 	del_timer_sync(&cfhsi->rx_slowpath_timer);
1276 	del_timer_sync(&cfhsi->aggregation_timer);
1277 
1278 	/* Cancel pending RX request (if any) */
1279 	cfhsi->ops->cfhsi_rx_cancel(cfhsi->ops);
1280 
1281 	/* Destroy workqueue */
1282 	destroy_workqueue(cfhsi->wq);
1283 
1284 	/* Store bufferes: will be freed later. */
1285 	tx_buf = cfhsi->tx_buf;
1286 	rx_buf = cfhsi->rx_buf;
1287 	flip_buf = cfhsi->rx_flip_buf;
1288 	/* Flush transmit queues. */
1289 	cfhsi_abort_tx(cfhsi);
1290 
1291 	/* Deactivate interface */
1292 	cfhsi->ops->cfhsi_down(cfhsi->ops);
1293 
1294 	/* Free buffers. */
1295 	kfree(tx_buf);
1296 	kfree(rx_buf);
1297 	kfree(flip_buf);
1298 	return 0;
1299 }
1300 
cfhsi_uninit(struct net_device * dev)1301 static void cfhsi_uninit(struct net_device *dev)
1302 {
1303 	struct cfhsi *cfhsi = netdev_priv(dev);
1304 	ASSERT_RTNL();
1305 	symbol_put(cfhsi_get_device);
1306 	list_del(&cfhsi->list);
1307 }
1308 
1309 static const struct net_device_ops cfhsi_netdevops = {
1310 	.ndo_uninit = cfhsi_uninit,
1311 	.ndo_open = cfhsi_open,
1312 	.ndo_stop = cfhsi_close,
1313 	.ndo_start_xmit = cfhsi_xmit
1314 };
1315 
cfhsi_netlink_parms(struct nlattr * data[],struct cfhsi * cfhsi)1316 static void cfhsi_netlink_parms(struct nlattr *data[], struct cfhsi *cfhsi)
1317 {
1318 	int i;
1319 
1320 	if (!data) {
1321 		pr_debug("no params data found\n");
1322 		return;
1323 	}
1324 
1325 	i = __IFLA_CAIF_HSI_INACTIVITY_TOUT;
1326 	/*
1327 	 * Inactivity timeout in millisecs. Lowest possible value is 1,
1328 	 * and highest possible is NEXT_TIMER_MAX_DELTA.
1329 	 */
1330 	if (data[i]) {
1331 		u32 inactivity_timeout = nla_get_u32(data[i]);
1332 		/* Pre-calculate inactivity timeout. */
1333 		cfhsi->cfg.inactivity_timeout =	inactivity_timeout * HZ / 1000;
1334 		if (cfhsi->cfg.inactivity_timeout == 0)
1335 			cfhsi->cfg.inactivity_timeout = 1;
1336 		else if (cfhsi->cfg.inactivity_timeout > NEXT_TIMER_MAX_DELTA)
1337 			cfhsi->cfg.inactivity_timeout = NEXT_TIMER_MAX_DELTA;
1338 	}
1339 
1340 	i = __IFLA_CAIF_HSI_AGGREGATION_TOUT;
1341 	if (data[i])
1342 		cfhsi->cfg.aggregation_timeout = nla_get_u32(data[i]);
1343 
1344 	i = __IFLA_CAIF_HSI_HEAD_ALIGN;
1345 	if (data[i])
1346 		cfhsi->cfg.head_align = nla_get_u32(data[i]);
1347 
1348 	i = __IFLA_CAIF_HSI_TAIL_ALIGN;
1349 	if (data[i])
1350 		cfhsi->cfg.tail_align = nla_get_u32(data[i]);
1351 
1352 	i = __IFLA_CAIF_HSI_QHIGH_WATERMARK;
1353 	if (data[i])
1354 		cfhsi->cfg.q_high_mark = nla_get_u32(data[i]);
1355 
1356 	i = __IFLA_CAIF_HSI_QLOW_WATERMARK;
1357 	if (data[i])
1358 		cfhsi->cfg.q_low_mark = nla_get_u32(data[i]);
1359 }
1360 
caif_hsi_changelink(struct net_device * dev,struct nlattr * tb[],struct nlattr * data[])1361 static int caif_hsi_changelink(struct net_device *dev, struct nlattr *tb[],
1362 				struct nlattr *data[])
1363 {
1364 	cfhsi_netlink_parms(data, netdev_priv(dev));
1365 	netdev_state_change(dev);
1366 	return 0;
1367 }
1368 
1369 static const struct nla_policy caif_hsi_policy[__IFLA_CAIF_HSI_MAX + 1] = {
1370 	[__IFLA_CAIF_HSI_INACTIVITY_TOUT] = { .type = NLA_U32, .len = 4 },
1371 	[__IFLA_CAIF_HSI_AGGREGATION_TOUT] = { .type = NLA_U32, .len = 4 },
1372 	[__IFLA_CAIF_HSI_HEAD_ALIGN] = { .type = NLA_U32, .len = 4 },
1373 	[__IFLA_CAIF_HSI_TAIL_ALIGN] = { .type = NLA_U32, .len = 4 },
1374 	[__IFLA_CAIF_HSI_QHIGH_WATERMARK] = { .type = NLA_U32, .len = 4 },
1375 	[__IFLA_CAIF_HSI_QLOW_WATERMARK] = { .type = NLA_U32, .len = 4 },
1376 };
1377 
caif_hsi_get_size(const struct net_device * dev)1378 static size_t caif_hsi_get_size(const struct net_device *dev)
1379 {
1380 	int i;
1381 	size_t s = 0;
1382 	for (i = __IFLA_CAIF_HSI_UNSPEC + 1; i < __IFLA_CAIF_HSI_MAX; i++)
1383 		s += nla_total_size(caif_hsi_policy[i].len);
1384 	return s;
1385 }
1386 
caif_hsi_fill_info(struct sk_buff * skb,const struct net_device * dev)1387 static int caif_hsi_fill_info(struct sk_buff *skb, const struct net_device *dev)
1388 {
1389 	struct cfhsi *cfhsi = netdev_priv(dev);
1390 
1391 	if (nla_put_u32(skb, __IFLA_CAIF_HSI_INACTIVITY_TOUT,
1392 			cfhsi->cfg.inactivity_timeout) ||
1393 	    nla_put_u32(skb, __IFLA_CAIF_HSI_AGGREGATION_TOUT,
1394 			cfhsi->cfg.aggregation_timeout) ||
1395 	    nla_put_u32(skb, __IFLA_CAIF_HSI_HEAD_ALIGN,
1396 			cfhsi->cfg.head_align) ||
1397 	    nla_put_u32(skb, __IFLA_CAIF_HSI_TAIL_ALIGN,
1398 			cfhsi->cfg.tail_align) ||
1399 	    nla_put_u32(skb, __IFLA_CAIF_HSI_QHIGH_WATERMARK,
1400 			cfhsi->cfg.q_high_mark) ||
1401 	    nla_put_u32(skb, __IFLA_CAIF_HSI_QLOW_WATERMARK,
1402 			cfhsi->cfg.q_low_mark))
1403 		return -EMSGSIZE;
1404 
1405 	return 0;
1406 }
1407 
caif_hsi_newlink(struct net * src_net,struct net_device * dev,struct nlattr * tb[],struct nlattr * data[])1408 static int caif_hsi_newlink(struct net *src_net, struct net_device *dev,
1409 			  struct nlattr *tb[], struct nlattr *data[])
1410 {
1411 	struct cfhsi *cfhsi = NULL;
1412 	struct cfhsi_ops *(*get_ops)(void);
1413 
1414 	ASSERT_RTNL();
1415 
1416 	cfhsi = netdev_priv(dev);
1417 	cfhsi_netlink_parms(data, cfhsi);
1418 	dev_net_set(cfhsi->ndev, src_net);
1419 
1420 	get_ops = symbol_get(cfhsi_get_ops);
1421 	if (!get_ops) {
1422 		pr_err("%s: failed to get the cfhsi_ops\n", __func__);
1423 		return -ENODEV;
1424 	}
1425 
1426 	/* Assign the HSI device. */
1427 	cfhsi->ops = (*get_ops)();
1428 	if (!cfhsi->ops) {
1429 		pr_err("%s: failed to get the cfhsi_ops\n", __func__);
1430 		goto err;
1431 	}
1432 
1433 	/* Assign the driver to this HSI device. */
1434 	cfhsi->ops->cb_ops = &cfhsi->cb_ops;
1435 	if (register_netdevice(dev)) {
1436 		pr_warn("%s: caif_hsi device registration failed\n", __func__);
1437 		goto err;
1438 	}
1439 	/* Add CAIF HSI device to list. */
1440 	list_add_tail(&cfhsi->list, &cfhsi_list);
1441 
1442 	return 0;
1443 err:
1444 	symbol_put(cfhsi_get_ops);
1445 	return -ENODEV;
1446 }
1447 
1448 static struct rtnl_link_ops caif_hsi_link_ops __read_mostly = {
1449 	.kind		= "cfhsi",
1450 	.priv_size	= sizeof(struct cfhsi),
1451 	.setup		= cfhsi_setup,
1452 	.maxtype	= __IFLA_CAIF_HSI_MAX,
1453 	.policy	= caif_hsi_policy,
1454 	.newlink	= caif_hsi_newlink,
1455 	.changelink	= caif_hsi_changelink,
1456 	.get_size	= caif_hsi_get_size,
1457 	.fill_info	= caif_hsi_fill_info,
1458 };
1459 
cfhsi_exit_module(void)1460 static void __exit cfhsi_exit_module(void)
1461 {
1462 	struct list_head *list_node;
1463 	struct list_head *n;
1464 	struct cfhsi *cfhsi;
1465 
1466 	rtnl_link_unregister(&caif_hsi_link_ops);
1467 
1468 	rtnl_lock();
1469 	list_for_each_safe(list_node, n, &cfhsi_list) {
1470 		cfhsi = list_entry(list_node, struct cfhsi, list);
1471 		unregister_netdev(cfhsi->ndev);
1472 	}
1473 	rtnl_unlock();
1474 }
1475 
cfhsi_init_module(void)1476 static int __init cfhsi_init_module(void)
1477 {
1478 	return rtnl_link_register(&caif_hsi_link_ops);
1479 }
1480 
1481 module_init(cfhsi_init_module);
1482 module_exit(cfhsi_exit_module);
1483