Linux Audio

Check our new training course

Loading...
Note: File does not exist in v3.1.
  1// SPDX-License-Identifier: GPL-2.0
  2/* Copyright (c) 2019, Vladimir Oltean <olteanv@gmail.com>
  3 */
  4#include <linux/if_vlan.h>
  5#include <linux/dsa/sja1105.h>
  6#include <linux/dsa/8021q.h>
  7#include <linux/packing.h>
  8
  9#include "tag.h"
 10#include "tag_8021q.h"
 11
 12#define SJA1105_NAME				"sja1105"
 13#define SJA1110_NAME				"sja1110"
 14
 15/* Is this a TX or an RX header? */
 16#define SJA1110_HEADER_HOST_TO_SWITCH		BIT(15)
 17
 18/* RX header */
 19#define SJA1110_RX_HEADER_IS_METADATA		BIT(14)
 20#define SJA1110_RX_HEADER_HOST_ONLY		BIT(13)
 21#define SJA1110_RX_HEADER_HAS_TRAILER		BIT(12)
 22
 23/* Trap-to-host format (no trailer present) */
 24#define SJA1110_RX_HEADER_SRC_PORT(x)		(((x) & GENMASK(7, 4)) >> 4)
 25#define SJA1110_RX_HEADER_SWITCH_ID(x)		((x) & GENMASK(3, 0))
 26
 27/* Timestamp format (trailer present) */
 28#define SJA1110_RX_HEADER_TRAILER_POS(x)	((x) & GENMASK(11, 0))
 29
 30#define SJA1110_RX_TRAILER_SWITCH_ID(x)		(((x) & GENMASK(7, 4)) >> 4)
 31#define SJA1110_RX_TRAILER_SRC_PORT(x)		((x) & GENMASK(3, 0))
 32
 33/* Meta frame format (for 2-step TX timestamps) */
 34#define SJA1110_RX_HEADER_N_TS(x)		(((x) & GENMASK(8, 4)) >> 4)
 35
 36/* TX header */
 37#define SJA1110_TX_HEADER_UPDATE_TC		BIT(14)
 38#define SJA1110_TX_HEADER_TAKE_TS		BIT(13)
 39#define SJA1110_TX_HEADER_TAKE_TS_CASC		BIT(12)
 40#define SJA1110_TX_HEADER_HAS_TRAILER		BIT(11)
 41
 42/* Only valid if SJA1110_TX_HEADER_HAS_TRAILER is false */
 43#define SJA1110_TX_HEADER_PRIO(x)		(((x) << 7) & GENMASK(10, 7))
 44#define SJA1110_TX_HEADER_TSTAMP_ID(x)		((x) & GENMASK(7, 0))
 45
 46/* Only valid if SJA1110_TX_HEADER_HAS_TRAILER is true */
 47#define SJA1110_TX_HEADER_TRAILER_POS(x)	((x) & GENMASK(10, 0))
 48
 49#define SJA1110_TX_TRAILER_TSTAMP_ID(x)		(((x) << 24) & GENMASK(31, 24))
 50#define SJA1110_TX_TRAILER_PRIO(x)		(((x) << 21) & GENMASK(23, 21))
 51#define SJA1110_TX_TRAILER_SWITCHID(x)		(((x) << 12) & GENMASK(15, 12))
 52#define SJA1110_TX_TRAILER_DESTPORTS(x)		(((x) << 1) & GENMASK(11, 1))
 53
 54#define SJA1110_META_TSTAMP_SIZE		10
 55
 56#define SJA1110_HEADER_LEN			4
 57#define SJA1110_RX_TRAILER_LEN			13
 58#define SJA1110_TX_TRAILER_LEN			4
 59#define SJA1110_MAX_PADDING_LEN			15
 60
 61struct sja1105_tagger_private {
 62	struct sja1105_tagger_data data; /* Must be first */
 63	/* Protects concurrent access to the meta state machine
 64	 * from taggers running on multiple ports on SMP systems
 65	 */
 66	spinlock_t meta_lock;
 67	struct sk_buff *stampable_skb;
 68	struct kthread_worker *xmit_worker;
 69};
 70
 71static struct sja1105_tagger_private *
 72sja1105_tagger_private(struct dsa_switch *ds)
 73{
 74	return ds->tagger_data;
 75}
 76
 77/* Similar to is_link_local_ether_addr(hdr->h_dest) but also covers PTP */
 78static bool sja1105_is_link_local(const struct sk_buff *skb)
 79{
 80	const struct ethhdr *hdr = eth_hdr(skb);
 81	u64 dmac = ether_addr_to_u64(hdr->h_dest);
 82
 83	if (ntohs(hdr->h_proto) == ETH_P_SJA1105_META)
 84		return false;
 85	if ((dmac & SJA1105_LINKLOCAL_FILTER_A_MASK) ==
 86		    SJA1105_LINKLOCAL_FILTER_A)
 87		return true;
 88	if ((dmac & SJA1105_LINKLOCAL_FILTER_B_MASK) ==
 89		    SJA1105_LINKLOCAL_FILTER_B)
 90		return true;
 91	return false;
 92}
 93
 94struct sja1105_meta {
 95	u64 tstamp;
 96	u64 dmac_byte_4;
 97	u64 dmac_byte_3;
 98	u64 source_port;
 99	u64 switch_id;
100};
101
102static void sja1105_meta_unpack(const struct sk_buff *skb,
103				struct sja1105_meta *meta)
104{
105	u8 *buf = skb_mac_header(skb) + ETH_HLEN;
106
107	/* UM10944.pdf section 4.2.17 AVB Parameters:
108	 * Structure of the meta-data follow-up frame.
109	 * It is in network byte order, so there are no quirks
110	 * while unpacking the meta frame.
111	 *
112	 * Also SJA1105 E/T only populates bits 23:0 of the timestamp
113	 * whereas P/Q/R/S does 32 bits. Since the structure is the
114	 * same and the E/T puts zeroes in the high-order byte, use
115	 * a unified unpacking command for both device series.
116	 */
117	packing(buf,     &meta->tstamp,     31, 0, 4, UNPACK, 0);
118	packing(buf + 4, &meta->dmac_byte_3, 7, 0, 1, UNPACK, 0);
119	packing(buf + 5, &meta->dmac_byte_4, 7, 0, 1, UNPACK, 0);
120	packing(buf + 6, &meta->source_port, 7, 0, 1, UNPACK, 0);
121	packing(buf + 7, &meta->switch_id,   7, 0, 1, UNPACK, 0);
122}
123
124static bool sja1105_is_meta_frame(const struct sk_buff *skb)
125{
126	const struct ethhdr *hdr = eth_hdr(skb);
127	u64 smac = ether_addr_to_u64(hdr->h_source);
128	u64 dmac = ether_addr_to_u64(hdr->h_dest);
129
130	if (smac != SJA1105_META_SMAC)
131		return false;
132	if (dmac != SJA1105_META_DMAC)
133		return false;
134	if (ntohs(hdr->h_proto) != ETH_P_SJA1105_META)
135		return false;
136	return true;
137}
138
139/* Calls sja1105_port_deferred_xmit in sja1105_main.c */
140static struct sk_buff *sja1105_defer_xmit(struct dsa_port *dp,
141					  struct sk_buff *skb)
142{
143	struct sja1105_tagger_data *tagger_data = sja1105_tagger_data(dp->ds);
144	struct sja1105_tagger_private *priv = sja1105_tagger_private(dp->ds);
145	void (*xmit_work_fn)(struct kthread_work *work);
146	struct sja1105_deferred_xmit_work *xmit_work;
147	struct kthread_worker *xmit_worker;
148
149	xmit_work_fn = tagger_data->xmit_work_fn;
150	xmit_worker = priv->xmit_worker;
151
152	if (!xmit_work_fn || !xmit_worker)
153		return NULL;
154
155	xmit_work = kzalloc(sizeof(*xmit_work), GFP_ATOMIC);
156	if (!xmit_work)
157		return NULL;
158
159	kthread_init_work(&xmit_work->work, xmit_work_fn);
160	/* Increase refcount so the kfree_skb in dsa_user_xmit
161	 * won't really free the packet.
162	 */
163	xmit_work->dp = dp;
164	xmit_work->skb = skb_get(skb);
165
166	kthread_queue_work(xmit_worker, &xmit_work->work);
167
168	return NULL;
169}
170
171/* Send VLAN tags with a TPID that blends in with whatever VLAN protocol a
172 * bridge spanning ports of this switch might have.
173 */
174static u16 sja1105_xmit_tpid(struct dsa_port *dp)
175{
176	struct dsa_switch *ds = dp->ds;
177	struct dsa_port *other_dp;
178	u16 proto;
179
180	/* Since VLAN awareness is global, then if this port is VLAN-unaware,
181	 * all ports are. Use the VLAN-unaware TPID used for tag_8021q.
182	 */
183	if (!dsa_port_is_vlan_filtering(dp))
184		return ETH_P_SJA1105;
185
186	/* Port is VLAN-aware, so there is a bridge somewhere (a single one,
187	 * we're sure about that). It may not be on this port though, so we
188	 * need to find it.
189	 */
190	dsa_switch_for_each_port(other_dp, ds) {
191		struct net_device *br = dsa_port_bridge_dev_get(other_dp);
192
193		if (!br)
194			continue;
195
196		/* Error is returned only if CONFIG_BRIDGE_VLAN_FILTERING,
197		 * which seems pointless to handle, as our port cannot become
198		 * VLAN-aware in that case.
199		 */
200		br_vlan_get_proto(br, &proto);
201
202		return proto;
203	}
204
205	WARN_ONCE(1, "Port is VLAN-aware but cannot find associated bridge!\n");
206
207	return ETH_P_SJA1105;
208}
209
210static struct sk_buff *sja1105_imprecise_xmit(struct sk_buff *skb,
211					      struct net_device *netdev)
212{
213	struct dsa_port *dp = dsa_user_to_port(netdev);
214	unsigned int bridge_num = dsa_port_bridge_num_get(dp);
215	struct net_device *br = dsa_port_bridge_dev_get(dp);
216	u16 tx_vid;
217
218	/* If the port is under a VLAN-aware bridge, just slide the
219	 * VLAN-tagged packet into the FDB and hope for the best.
220	 * This works because we support a single VLAN-aware bridge
221	 * across the entire dst, and its VLANs cannot be shared with
222	 * any standalone port.
223	 */
224	if (br_vlan_enabled(br))
225		return skb;
226
227	/* If the port is under a VLAN-unaware bridge, use an imprecise
228	 * TX VLAN that targets the bridge's entire broadcast domain,
229	 * instead of just the specific port.
230	 */
231	tx_vid = dsa_tag_8021q_bridge_vid(bridge_num);
232
233	return dsa_8021q_xmit(skb, netdev, sja1105_xmit_tpid(dp), tx_vid);
234}
235
236/* Transform untagged control packets into pvid-tagged control packets so that
237 * all packets sent by this tagger are VLAN-tagged and we can configure the
238 * switch to drop untagged packets coming from the DSA conduit.
239 */
240static struct sk_buff *sja1105_pvid_tag_control_pkt(struct dsa_port *dp,
241						    struct sk_buff *skb, u8 pcp)
242{
243	__be16 xmit_tpid = htons(sja1105_xmit_tpid(dp));
244	struct vlan_ethhdr *hdr;
245
246	/* If VLAN tag is in hwaccel area, move it to the payload
247	 * to deal with both cases uniformly and to ensure that
248	 * the VLANs are added in the right order.
249	 */
250	if (unlikely(skb_vlan_tag_present(skb))) {
251		skb = __vlan_hwaccel_push_inside(skb);
252		if (!skb)
253			return NULL;
254	}
255
256	hdr = skb_vlan_eth_hdr(skb);
257
258	/* If skb is already VLAN-tagged, leave that VLAN ID in place */
259	if (hdr->h_vlan_proto == xmit_tpid)
260		return skb;
261
262	return vlan_insert_tag(skb, xmit_tpid, (pcp << VLAN_PRIO_SHIFT) |
263			       SJA1105_DEFAULT_VLAN);
264}
265
266static struct sk_buff *sja1105_xmit(struct sk_buff *skb,
267				    struct net_device *netdev)
268{
269	struct dsa_port *dp = dsa_user_to_port(netdev);
270	u16 queue_mapping = skb_get_queue_mapping(skb);
271	u8 pcp = netdev_txq_to_tc(netdev, queue_mapping);
272	u16 tx_vid = dsa_tag_8021q_standalone_vid(dp);
273
274	if (skb->offload_fwd_mark)
275		return sja1105_imprecise_xmit(skb, netdev);
276
277	/* Transmitting management traffic does not rely upon switch tagging,
278	 * but instead SPI-installed management routes. Part 2 of this
279	 * is the .port_deferred_xmit driver callback.
280	 */
281	if (unlikely(sja1105_is_link_local(skb))) {
282		skb = sja1105_pvid_tag_control_pkt(dp, skb, pcp);
283		if (!skb)
284			return NULL;
285
286		return sja1105_defer_xmit(dp, skb);
287	}
288
289	return dsa_8021q_xmit(skb, netdev, sja1105_xmit_tpid(dp),
290			     ((pcp << VLAN_PRIO_SHIFT) | tx_vid));
291}
292
293static struct sk_buff *sja1110_xmit(struct sk_buff *skb,
294				    struct net_device *netdev)
295{
296	struct sk_buff *clone = SJA1105_SKB_CB(skb)->clone;
297	struct dsa_port *dp = dsa_user_to_port(netdev);
298	u16 queue_mapping = skb_get_queue_mapping(skb);
299	u8 pcp = netdev_txq_to_tc(netdev, queue_mapping);
300	u16 tx_vid = dsa_tag_8021q_standalone_vid(dp);
301	__be32 *tx_trailer;
302	__be16 *tx_header;
303	int trailer_pos;
304
305	if (skb->offload_fwd_mark)
306		return sja1105_imprecise_xmit(skb, netdev);
307
308	/* Transmitting control packets is done using in-band control
309	 * extensions, while data packets are transmitted using
310	 * tag_8021q TX VLANs.
311	 */
312	if (likely(!sja1105_is_link_local(skb)))
313		return dsa_8021q_xmit(skb, netdev, sja1105_xmit_tpid(dp),
314				     ((pcp << VLAN_PRIO_SHIFT) | tx_vid));
315
316	skb = sja1105_pvid_tag_control_pkt(dp, skb, pcp);
317	if (!skb)
318		return NULL;
319
320	skb_push(skb, SJA1110_HEADER_LEN);
321
322	dsa_alloc_etype_header(skb, SJA1110_HEADER_LEN);
323
324	trailer_pos = skb->len;
325
326	tx_header = dsa_etype_header_pos_tx(skb);
327	tx_trailer = skb_put(skb, SJA1110_TX_TRAILER_LEN);
328
329	tx_header[0] = htons(ETH_P_SJA1110);
330	tx_header[1] = htons(SJA1110_HEADER_HOST_TO_SWITCH |
331			     SJA1110_TX_HEADER_HAS_TRAILER |
332			     SJA1110_TX_HEADER_TRAILER_POS(trailer_pos));
333	*tx_trailer = cpu_to_be32(SJA1110_TX_TRAILER_PRIO(pcp) |
334				  SJA1110_TX_TRAILER_SWITCHID(dp->ds->index) |
335				  SJA1110_TX_TRAILER_DESTPORTS(BIT(dp->index)));
336	if (clone) {
337		u8 ts_id = SJA1105_SKB_CB(clone)->ts_id;
338
339		tx_header[1] |= htons(SJA1110_TX_HEADER_TAKE_TS);
340		*tx_trailer |= cpu_to_be32(SJA1110_TX_TRAILER_TSTAMP_ID(ts_id));
341	}
342
343	return skb;
344}
345
346static void sja1105_transfer_meta(struct sk_buff *skb,
347				  const struct sja1105_meta *meta)
348{
349	struct ethhdr *hdr = eth_hdr(skb);
350
351	hdr->h_dest[3] = meta->dmac_byte_3;
352	hdr->h_dest[4] = meta->dmac_byte_4;
353	SJA1105_SKB_CB(skb)->tstamp = meta->tstamp;
354}
355
356/* This is a simple state machine which follows the hardware mechanism of
357 * generating RX timestamps:
358 *
359 * After each timestampable skb (all traffic for which send_meta1 and
360 * send_meta0 is true, aka all MAC-filtered link-local traffic) a meta frame
361 * containing a partial timestamp is immediately generated by the switch and
362 * sent as a follow-up to the link-local frame on the CPU port.
363 *
364 * The meta frames have no unique identifier (such as sequence number) by which
365 * one may pair them to the correct timestampable frame.
366 * Instead, the switch has internal logic that ensures no frames are sent on
367 * the CPU port between a link-local timestampable frame and its corresponding
368 * meta follow-up. It also ensures strict ordering between ports (lower ports
369 * have higher priority towards the CPU port). For this reason, a per-port
370 * data structure is not needed/desirable.
371 *
372 * This function pairs the link-local frame with its partial timestamp from the
373 * meta follow-up frame. The full timestamp will be reconstructed later in a
374 * work queue.
375 */
376static struct sk_buff
377*sja1105_rcv_meta_state_machine(struct sk_buff *skb,
378				struct sja1105_meta *meta,
379				bool is_link_local,
380				bool is_meta)
381{
382	/* Step 1: A timestampable frame was received.
383	 * Buffer it until we get its meta frame.
384	 */
385	if (is_link_local) {
386		struct dsa_port *dp = dsa_user_to_port(skb->dev);
387		struct sja1105_tagger_private *priv;
388		struct dsa_switch *ds = dp->ds;
389
390		priv = sja1105_tagger_private(ds);
391
392		spin_lock(&priv->meta_lock);
393		/* Was this a link-local frame instead of the meta
394		 * that we were expecting?
395		 */
396		if (priv->stampable_skb) {
397			dev_err_ratelimited(ds->dev,
398					    "Expected meta frame, is %12llx "
399					    "in the DSA conduit multicast filter?\n",
400					    SJA1105_META_DMAC);
401			kfree_skb(priv->stampable_skb);
402		}
403
404		/* Hold a reference to avoid dsa_switch_rcv
405		 * from freeing the skb.
406		 */
407		priv->stampable_skb = skb_get(skb);
408		spin_unlock(&priv->meta_lock);
409
410		/* Tell DSA we got nothing */
411		return NULL;
412
413	/* Step 2: The meta frame arrived.
414	 * Time to take the stampable skb out of the closet, annotate it
415	 * with the partial timestamp, and pretend that we received it
416	 * just now (basically masquerade the buffered frame as the meta
417	 * frame, which serves no further purpose).
418	 */
419	} else if (is_meta) {
420		struct dsa_port *dp = dsa_user_to_port(skb->dev);
421		struct sja1105_tagger_private *priv;
422		struct dsa_switch *ds = dp->ds;
423		struct sk_buff *stampable_skb;
424
425		priv = sja1105_tagger_private(ds);
426
427		spin_lock(&priv->meta_lock);
428
429		stampable_skb = priv->stampable_skb;
430		priv->stampable_skb = NULL;
431
432		/* Was this a meta frame instead of the link-local
433		 * that we were expecting?
434		 */
435		if (!stampable_skb) {
436			dev_err_ratelimited(ds->dev,
437					    "Unexpected meta frame\n");
438			spin_unlock(&priv->meta_lock);
439			return NULL;
440		}
441
442		if (stampable_skb->dev != skb->dev) {
443			dev_err_ratelimited(ds->dev,
444					    "Meta frame on wrong port\n");
445			spin_unlock(&priv->meta_lock);
446			return NULL;
447		}
448
449		/* Free the meta frame and give DSA the buffered stampable_skb
450		 * for further processing up the network stack.
451		 */
452		kfree_skb(skb);
453		skb = stampable_skb;
454		sja1105_transfer_meta(skb, meta);
455
456		spin_unlock(&priv->meta_lock);
457	}
458
459	return skb;
460}
461
462static bool sja1105_skb_has_tag_8021q(const struct sk_buff *skb)
463{
464	u16 tpid = ntohs(eth_hdr(skb)->h_proto);
465
466	return tpid == ETH_P_SJA1105 || tpid == ETH_P_8021Q ||
467	       skb_vlan_tag_present(skb);
468}
469
470static bool sja1110_skb_has_inband_control_extension(const struct sk_buff *skb)
471{
472	return ntohs(eth_hdr(skb)->h_proto) == ETH_P_SJA1110;
473}
474
475static struct sk_buff *sja1105_rcv(struct sk_buff *skb,
476				   struct net_device *netdev)
477{
478	int source_port = -1, switch_id = -1, vbid = -1, vid = -1;
479	struct sja1105_meta meta = {0};
480	struct ethhdr *hdr;
481	bool is_link_local;
482	bool is_meta;
483
484	hdr = eth_hdr(skb);
485	is_link_local = sja1105_is_link_local(skb);
486	is_meta = sja1105_is_meta_frame(skb);
487
488	if (is_link_local) {
489		/* Management traffic path. Switch embeds the switch ID and
490		 * port ID into bytes of the destination MAC, courtesy of
491		 * the incl_srcpt options.
492		 */
493		source_port = hdr->h_dest[3];
494		switch_id = hdr->h_dest[4];
495	} else if (is_meta) {
496		sja1105_meta_unpack(skb, &meta);
497		source_port = meta.source_port;
498		switch_id = meta.switch_id;
499	}
500
501	/* Normal data plane traffic and link-local frames are tagged with
502	 * a tag_8021q VLAN which we have to strip
503	 */
504	if (sja1105_skb_has_tag_8021q(skb))
505		dsa_8021q_rcv(skb, &source_port, &switch_id, &vbid, &vid);
506	else if (source_port == -1 && switch_id == -1)
507		/* Packets with no source information have no chance of
508		 * getting accepted, drop them straight away.
509		 */
510		return NULL;
511
512	skb->dev = dsa_tag_8021q_find_user(netdev, source_port, switch_id,
513					   vid, vbid);
514	if (!skb->dev) {
515		netdev_warn(netdev, "Couldn't decode source port\n");
516		return NULL;
517	}
518
519	if (!is_link_local)
520		dsa_default_offload_fwd_mark(skb);
521
522	return sja1105_rcv_meta_state_machine(skb, &meta, is_link_local,
523					      is_meta);
524}
525
526static struct sk_buff *sja1110_rcv_meta(struct sk_buff *skb, u16 rx_header)
527{
528	u8 *buf = dsa_etype_header_pos_rx(skb) + SJA1110_HEADER_LEN;
529	int switch_id = SJA1110_RX_HEADER_SWITCH_ID(rx_header);
530	int n_ts = SJA1110_RX_HEADER_N_TS(rx_header);
531	struct sja1105_tagger_data *tagger_data;
532	struct net_device *conduit = skb->dev;
533	struct dsa_port *cpu_dp;
534	struct dsa_switch *ds;
535	int i;
536
537	cpu_dp = conduit->dsa_ptr;
538	ds = dsa_switch_find(cpu_dp->dst->index, switch_id);
539	if (!ds) {
540		net_err_ratelimited("%s: cannot find switch id %d\n",
541				    conduit->name, switch_id);
542		return NULL;
543	}
544
545	tagger_data = sja1105_tagger_data(ds);
546	if (!tagger_data->meta_tstamp_handler)
547		return NULL;
548
549	for (i = 0; i <= n_ts; i++) {
550		u8 ts_id, source_port, dir;
551		u64 tstamp;
552
553		ts_id = buf[0];
554		source_port = (buf[1] & GENMASK(7, 4)) >> 4;
555		dir = (buf[1] & BIT(3)) >> 3;
556		tstamp = be64_to_cpu(*(__be64 *)(buf + 2));
557
558		tagger_data->meta_tstamp_handler(ds, source_port, ts_id, dir,
559						 tstamp);
560
561		buf += SJA1110_META_TSTAMP_SIZE;
562	}
563
564	/* Discard the meta frame, we've consumed the timestamps it contained */
565	return NULL;
566}
567
568static struct sk_buff *sja1110_rcv_inband_control_extension(struct sk_buff *skb,
569							    int *source_port,
570							    int *switch_id,
571							    bool *host_only)
572{
573	u16 rx_header;
574
575	if (unlikely(!pskb_may_pull(skb, SJA1110_HEADER_LEN)))
576		return NULL;
577
578	/* skb->data points to skb_mac_header(skb) + ETH_HLEN, which is exactly
579	 * what we need because the caller has checked the EtherType (which is
580	 * located 2 bytes back) and we just need a pointer to the header that
581	 * comes afterwards.
582	 */
583	rx_header = ntohs(*(__be16 *)skb->data);
584
585	if (rx_header & SJA1110_RX_HEADER_HOST_ONLY)
586		*host_only = true;
587
588	if (rx_header & SJA1110_RX_HEADER_IS_METADATA)
589		return sja1110_rcv_meta(skb, rx_header);
590
591	/* Timestamp frame, we have a trailer */
592	if (rx_header & SJA1110_RX_HEADER_HAS_TRAILER) {
593		int start_of_padding = SJA1110_RX_HEADER_TRAILER_POS(rx_header);
594		u8 *rx_trailer = skb_tail_pointer(skb) - SJA1110_RX_TRAILER_LEN;
595		u64 *tstamp = &SJA1105_SKB_CB(skb)->tstamp;
596		u8 last_byte = rx_trailer[12];
597
598		/* The timestamp is unaligned, so we need to use packing()
599		 * to get it
600		 */
601		packing(rx_trailer, tstamp, 63, 0, 8, UNPACK, 0);
602
603		*source_port = SJA1110_RX_TRAILER_SRC_PORT(last_byte);
604		*switch_id = SJA1110_RX_TRAILER_SWITCH_ID(last_byte);
605
606		/* skb->len counts from skb->data, while start_of_padding
607		 * counts from the destination MAC address. Right now skb->data
608		 * is still as set by the DSA conduit, so to trim away the
609		 * padding and trailer we need to account for the fact that
610		 * skb->data points to skb_mac_header(skb) + ETH_HLEN.
611		 */
612		if (pskb_trim_rcsum(skb, start_of_padding - ETH_HLEN))
613			return NULL;
614	/* Trap-to-host frame, no timestamp trailer */
615	} else {
616		*source_port = SJA1110_RX_HEADER_SRC_PORT(rx_header);
617		*switch_id = SJA1110_RX_HEADER_SWITCH_ID(rx_header);
618	}
619
620	/* Advance skb->data past the DSA header */
621	skb_pull_rcsum(skb, SJA1110_HEADER_LEN);
622
623	dsa_strip_etype_header(skb, SJA1110_HEADER_LEN);
624
625	/* With skb->data in its final place, update the MAC header
626	 * so that eth_hdr() continues to works properly.
627	 */
628	skb_set_mac_header(skb, -ETH_HLEN);
629
630	return skb;
631}
632
633static struct sk_buff *sja1110_rcv(struct sk_buff *skb,
634				   struct net_device *netdev)
635{
636	int source_port = -1, switch_id = -1, vbid = -1, vid = -1;
637	bool host_only = false;
638
639	if (sja1110_skb_has_inband_control_extension(skb)) {
640		skb = sja1110_rcv_inband_control_extension(skb, &source_port,
641							   &switch_id,
642							   &host_only);
643		if (!skb)
644			return NULL;
645	}
646
647	/* Packets with in-band control extensions might still have RX VLANs */
648	if (likely(sja1105_skb_has_tag_8021q(skb)))
649		dsa_8021q_rcv(skb, &source_port, &switch_id, &vbid, &vid);
650
651	skb->dev = dsa_tag_8021q_find_user(netdev, source_port, switch_id,
652					   vid, vbid);
653
654	if (!skb->dev) {
655		netdev_warn(netdev, "Couldn't decode source port\n");
656		return NULL;
657	}
658
659	if (!host_only)
660		dsa_default_offload_fwd_mark(skb);
661
662	return skb;
663}
664
665static void sja1105_flow_dissect(const struct sk_buff *skb, __be16 *proto,
666				 int *offset)
667{
668	/* No tag added for management frames, all ok */
669	if (unlikely(sja1105_is_link_local(skb)))
670		return;
671
672	dsa_tag_generic_flow_dissect(skb, proto, offset);
673}
674
675static void sja1110_flow_dissect(const struct sk_buff *skb, __be16 *proto,
676				 int *offset)
677{
678	/* Management frames have 2 DSA tags on RX, so the needed_headroom we
679	 * declared is fine for the generic dissector adjustment procedure.
680	 */
681	if (unlikely(sja1105_is_link_local(skb)))
682		return dsa_tag_generic_flow_dissect(skb, proto, offset);
683
684	/* For the rest, there is a single DSA tag, the tag_8021q one */
685	*offset = VLAN_HLEN;
686	*proto = ((__be16 *)skb->data)[(VLAN_HLEN / 2) - 1];
687}
688
689static void sja1105_disconnect(struct dsa_switch *ds)
690{
691	struct sja1105_tagger_private *priv = ds->tagger_data;
692
693	kthread_destroy_worker(priv->xmit_worker);
694	kfree(priv);
695	ds->tagger_data = NULL;
696}
697
698static int sja1105_connect(struct dsa_switch *ds)
699{
700	struct sja1105_tagger_private *priv;
701	struct kthread_worker *xmit_worker;
702	int err;
703
704	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
705	if (!priv)
706		return -ENOMEM;
707
708	spin_lock_init(&priv->meta_lock);
709
710	xmit_worker = kthread_create_worker(0, "dsa%d:%d_xmit",
711					    ds->dst->index, ds->index);
712	if (IS_ERR(xmit_worker)) {
713		err = PTR_ERR(xmit_worker);
714		kfree(priv);
715		return err;
716	}
717
718	priv->xmit_worker = xmit_worker;
719	ds->tagger_data = priv;
720
721	return 0;
722}
723
724static const struct dsa_device_ops sja1105_netdev_ops = {
725	.name = SJA1105_NAME,
726	.proto = DSA_TAG_PROTO_SJA1105,
727	.xmit = sja1105_xmit,
728	.rcv = sja1105_rcv,
729	.connect = sja1105_connect,
730	.disconnect = sja1105_disconnect,
731	.needed_headroom = VLAN_HLEN,
732	.flow_dissect = sja1105_flow_dissect,
733	.promisc_on_conduit = true,
734};
735
736DSA_TAG_DRIVER(sja1105_netdev_ops);
737MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_SJA1105, SJA1105_NAME);
738
739static const struct dsa_device_ops sja1110_netdev_ops = {
740	.name = SJA1110_NAME,
741	.proto = DSA_TAG_PROTO_SJA1110,
742	.xmit = sja1110_xmit,
743	.rcv = sja1110_rcv,
744	.connect = sja1105_connect,
745	.disconnect = sja1105_disconnect,
746	.flow_dissect = sja1110_flow_dissect,
747	.needed_headroom = SJA1110_HEADER_LEN + VLAN_HLEN,
748	.needed_tailroom = SJA1110_RX_TRAILER_LEN + SJA1110_MAX_PADDING_LEN,
749};
750
751DSA_TAG_DRIVER(sja1110_netdev_ops);
752MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_SJA1110, SJA1110_NAME);
753
754static struct dsa_tag_driver *sja1105_tag_driver_array[] = {
755	&DSA_TAG_DRIVER_NAME(sja1105_netdev_ops),
756	&DSA_TAG_DRIVER_NAME(sja1110_netdev_ops),
757};
758
759module_dsa_tag_drivers(sja1105_tag_driver_array);
760
761MODULE_DESCRIPTION("DSA tag driver for NXP SJA1105 switches");
762MODULE_LICENSE("GPL v2");