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
26MODULE_LICENSE("GPL");
27MODULE_AUTHOR("Daniel Martensson");
28MODULE_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
34static 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
67static LIST_HEAD(cfhsi_list);
68
69static 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
81static 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
99static 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
118static 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
132static 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
140static 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
163static 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
217static 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
331static 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
367static 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
399static 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
412static 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
500static 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
529static 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
617static 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
737out_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
744static 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
754static 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
771static 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	}
844wake_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
898static 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
961static 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
972static 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
991static 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
1004static 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
1014static 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
1113static const struct net_device_ops cfhsi_netdevops;
1114
1115static 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
1136static 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
1262static 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
1301static 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
1309static 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
1316static 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
1361static 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
1369static 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
1378static 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
1387static 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
1408static 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
1419	get_ops = symbol_get(cfhsi_get_ops);
1420	if (!get_ops) {
1421		pr_err("%s: failed to get the cfhsi_ops\n", __func__);
1422		return -ENODEV;
1423	}
1424
1425	/* Assign the HSI device. */
1426	cfhsi->ops = (*get_ops)();
1427	if (!cfhsi->ops) {
1428		pr_err("%s: failed to get the cfhsi_ops\n", __func__);
1429		goto err;
1430	}
1431
1432	/* Assign the driver to this HSI device. */
1433	cfhsi->ops->cb_ops = &cfhsi->cb_ops;
1434	if (register_netdevice(dev)) {
1435		pr_warn("%s: caif_hsi device registration failed\n", __func__);
1436		goto err;
1437	}
1438	/* Add CAIF HSI device to list. */
1439	list_add_tail(&cfhsi->list, &cfhsi_list);
1440
1441	return 0;
1442err:
1443	symbol_put(cfhsi_get_ops);
1444	return -ENODEV;
1445}
1446
1447static struct rtnl_link_ops caif_hsi_link_ops __read_mostly = {
1448	.kind		= "cfhsi",
1449	.priv_size	= sizeof(struct cfhsi),
1450	.setup		= cfhsi_setup,
1451	.maxtype	= __IFLA_CAIF_HSI_MAX,
1452	.policy	= caif_hsi_policy,
1453	.newlink	= caif_hsi_newlink,
1454	.changelink	= caif_hsi_changelink,
1455	.get_size	= caif_hsi_get_size,
1456	.fill_info	= caif_hsi_fill_info,
1457};
1458
1459static void __exit cfhsi_exit_module(void)
1460{
1461	struct list_head *list_node;
1462	struct list_head *n;
1463	struct cfhsi *cfhsi;
1464
1465	rtnl_link_unregister(&caif_hsi_link_ops);
1466
1467	rtnl_lock();
1468	list_for_each_safe(list_node, n, &cfhsi_list) {
1469		cfhsi = list_entry(list_node, struct cfhsi, list);
1470		unregister_netdev(cfhsi->ndev);
1471	}
1472	rtnl_unlock();
1473}
1474
1475static int __init cfhsi_init_module(void)
1476{
1477	return rtnl_link_register(&caif_hsi_link_ops);
1478}
1479
1480module_init(cfhsi_init_module);
1481module_exit(cfhsi_exit_module);
1482