tag_ksz.c

  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * net/dsa/tag_ksz.c - Microchip KSZ Switch tag format handling
  4 * Copyright (c) 2017 Microchip Technology
  5 */
  6
  7#include <linux/dsa/ksz_common.h>
  8#include <linux/etherdevice.h>
  9#include <linux/list.h>
 10#include <linux/ptp_classify.h>
 11#include <net/dsa.h>
 12
 13#include "tag.h"
 14
 15#define KSZ8795_NAME "ksz8795"
 16#define KSZ9477_NAME "ksz9477"
 17#define KSZ9893_NAME "ksz9893"
 18#define LAN937X_NAME "lan937x"
 19
 20/* Typically only one byte is used for tail tag. */
 21#define KSZ_PTP_TAG_LEN			4
 22#define KSZ_EGRESS_TAG_LEN		1
 23#define KSZ_INGRESS_TAG_LEN		1
 24
 25#define KSZ_HWTS_EN  0
 26
 27struct ksz_tagger_private {
 28	struct ksz_tagger_data data; /* Must be first */
 29	unsigned long state;
 30	struct kthread_worker *xmit_worker;
 31};
 32
 33static struct ksz_tagger_private *
 34ksz_tagger_private(struct dsa_switch *ds)
 35{
 36	return ds->tagger_data;
 37}
 38
 39static void ksz_hwtstamp_set_state(struct dsa_switch *ds, bool on)
 40{
 41	struct ksz_tagger_private *priv = ksz_tagger_private(ds);
 42
 43	if (on)
 44		set_bit(KSZ_HWTS_EN, &priv->state);
 45	else
 46		clear_bit(KSZ_HWTS_EN, &priv->state);
 47}
 48
 49static void ksz_disconnect(struct dsa_switch *ds)
 50{
 51	struct ksz_tagger_private *priv = ds->tagger_data;
 52
 53	kthread_destroy_worker(priv->xmit_worker);
 54	kfree(priv);
 55	ds->tagger_data = NULL;
 56}
 57
 58static int ksz_connect(struct dsa_switch *ds)
 59{
 60	struct ksz_tagger_data *tagger_data;
 61	struct kthread_worker *xmit_worker;
 62	struct ksz_tagger_private *priv;
 63	int ret;
 64
 65	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 66	if (!priv)
 67		return -ENOMEM;
 68
 69	xmit_worker = kthread_run_worker(0, "dsa%d:%d_xmit",
 70					    ds->dst->index, ds->index);
 71	if (IS_ERR(xmit_worker)) {
 72		ret = PTR_ERR(xmit_worker);
 73		kfree(priv);
 74		return ret;
 75	}
 76
 77	priv->xmit_worker = xmit_worker;
 78	/* Export functions for switch driver use */
 79	tagger_data = &priv->data;
 80	tagger_data->hwtstamp_set_state = ksz_hwtstamp_set_state;
 81	ds->tagger_data = priv;
 82
 83	return 0;
 84}
 85
 86static struct sk_buff *ksz_common_rcv(struct sk_buff *skb,
 87				      struct net_device *dev,
 88				      unsigned int port, unsigned int len)
 89{
 90	skb->dev = dsa_conduit_find_user(dev, 0, port);
 91	if (!skb->dev)
 92		return NULL;
 93
 94	if (pskb_trim_rcsum(skb, skb->len - len))
 95		return NULL;
 96
 97	dsa_default_offload_fwd_mark(skb);
 98
 99	return skb;
100}
101
102/*
103 * For Ingress (Host -> KSZ8795), 1 byte is added before FCS.
104 * ---------------------------------------------------------------------------
105 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag(1byte)|FCS(4bytes)
106 * ---------------------------------------------------------------------------
107 * tag : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x10=port5)
108 *
109 * For Egress (KSZ8795 -> Host), 1 byte is added before FCS.
110 * ---------------------------------------------------------------------------
111 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|tag0(1byte)|FCS(4bytes)
112 * ---------------------------------------------------------------------------
113 * tag0 : zero-based value represents port
114 *	  (eg, 0x0=port1, 0x2=port3, 0x3=port4)
115 */
116
117#define KSZ8795_TAIL_TAG_EG_PORT_M	GENMASK(1, 0)
118#define KSZ8795_TAIL_TAG_OVERRIDE	BIT(6)
119#define KSZ8795_TAIL_TAG_LOOKUP		BIT(7)
120
121static struct sk_buff *ksz8795_xmit(struct sk_buff *skb, struct net_device *dev)
122{
123	struct ethhdr *hdr;
124	u8 *tag;
125
126	if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
127		return NULL;
128
129	/* Tag encoding */
130	tag = skb_put(skb, KSZ_INGRESS_TAG_LEN);
131	hdr = skb_eth_hdr(skb);
132
133	*tag = dsa_xmit_port_mask(skb, dev);
134	if (is_link_local_ether_addr(hdr->h_dest))
135		*tag |= KSZ8795_TAIL_TAG_OVERRIDE;
136
137	return skb;
138}
139
140static struct sk_buff *ksz8795_rcv(struct sk_buff *skb, struct net_device *dev)
141{
142	u8 *tag;
143
144	if (skb_linearize(skb))
145		return NULL;
146
147	tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
148
149	return ksz_common_rcv(skb, dev, tag[0] & KSZ8795_TAIL_TAG_EG_PORT_M,
150			      KSZ_EGRESS_TAG_LEN);
151}
152
153static const struct dsa_device_ops ksz8795_netdev_ops = {
154	.name	= KSZ8795_NAME,
155	.proto	= DSA_TAG_PROTO_KSZ8795,
156	.xmit	= ksz8795_xmit,
157	.rcv	= ksz8795_rcv,
158	.needed_tailroom = KSZ_INGRESS_TAG_LEN,
159};
160
161DSA_TAG_DRIVER(ksz8795_netdev_ops);
162MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ8795, KSZ8795_NAME);
163
164/*
165 * For Ingress (Host -> KSZ9477), 2/6 bytes are added before FCS.
166 * ---------------------------------------------------------------------------
167 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|ts(4bytes)|tag0(1byte)|tag1(1byte)|
168 * FCS(4bytes)
169 * ---------------------------------------------------------------------------
170 * ts   : time stamp (Present only if PTP is enabled in the Hardware)
171 * tag0 : Prioritization (not used now)
172 * tag1 : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x10=port5)
173 *
174 * For Egress (KSZ9477 -> Host), 1/5 bytes is added before FCS.
175 * ---------------------------------------------------------------------------
176 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|ts(4bytes)|tag0(1byte)|FCS(4bytes)
177 * ---------------------------------------------------------------------------
178 * ts   : time stamp (Present only if bit 7 of tag0 is set)
179 * tag0 : zero-based value represents port
180 *	  (eg, 0x00=port1, 0x02=port3, 0x06=port7)
181 */
182
183#define KSZ9477_INGRESS_TAG_LEN		2
184#define KSZ9477_PTP_TAG_LEN		4
185#define KSZ9477_PTP_TAG_INDICATION	BIT(7)
186
187#define KSZ9477_TAIL_TAG_EG_PORT_M	GENMASK(2, 0)
188#define KSZ9477_TAIL_TAG_PRIO		GENMASK(8, 7)
189#define KSZ9477_TAIL_TAG_OVERRIDE	BIT(9)
190#define KSZ9477_TAIL_TAG_LOOKUP		BIT(10)
191
192static void ksz_rcv_timestamp(struct sk_buff *skb, u8 *tag)
193{
194	u8 *tstamp_raw = tag - KSZ_PTP_TAG_LEN;
195	ktime_t tstamp;
196
197	tstamp = ksz_decode_tstamp(get_unaligned_be32(tstamp_raw));
198	KSZ_SKB_CB(skb)->tstamp = tstamp;
199}
200
201/* Time stamp tag *needs* to be inserted if PTP is enabled in hardware.
202 * Regardless of Whether it is a PTP frame or not.
203 */
204static void ksz_xmit_timestamp(struct dsa_port *dp, struct sk_buff *skb)
205{
206	struct ksz_tagger_private *priv;
207	struct ptp_header *ptp_hdr;
208	unsigned int ptp_type;
209	u32 tstamp_raw = 0;
210	s64 correction;
211
212	priv = ksz_tagger_private(dp->ds);
213
214	if (!test_bit(KSZ_HWTS_EN, &priv->state))
215		return;
216
217	if (!KSZ_SKB_CB(skb)->update_correction)
218		goto output_tag;
219
220	ptp_type = KSZ_SKB_CB(skb)->ptp_type;
221
222	ptp_hdr = ptp_parse_header(skb, ptp_type);
223	if (!ptp_hdr)
224		goto output_tag;
225
226	correction = (s64)get_unaligned_be64(&ptp_hdr->correction);
227
228	if (correction < 0) {
229		struct timespec64 ts;
230
231		ts = ns_to_timespec64(-correction >> 16);
232		tstamp_raw = ((ts.tv_sec & 3) << 30) | ts.tv_nsec;
233
234		/* Set correction field to 0 and update UDP checksum */
235		ptp_header_update_correction(skb, ptp_type, ptp_hdr, 0);
236	}
237
238output_tag:
239	put_unaligned_be32(tstamp_raw, skb_put(skb, KSZ_PTP_TAG_LEN));
240}
241
242/* Defer transmit if waiting for egress time stamp is required.  */
243static struct sk_buff *ksz_defer_xmit(struct dsa_port *dp, struct sk_buff *skb)
244{
245	struct ksz_tagger_data *tagger_data = ksz_tagger_data(dp->ds);
246	struct ksz_tagger_private *priv = ksz_tagger_private(dp->ds);
247	void (*xmit_work_fn)(struct kthread_work *work);
248	struct sk_buff *clone = KSZ_SKB_CB(skb)->clone;
249	struct ksz_deferred_xmit_work *xmit_work;
250	struct kthread_worker *xmit_worker;
251
252	if (!clone)
253		return skb;  /* no deferred xmit for this packet */
254
255	xmit_work_fn = tagger_data->xmit_work_fn;
256	xmit_worker = priv->xmit_worker;
257
258	if (!xmit_work_fn || !xmit_worker)
259		return NULL;
260
261	xmit_work = kzalloc(sizeof(*xmit_work), GFP_ATOMIC);
262	if (!xmit_work)
263		return NULL;
264
265	kthread_init_work(&xmit_work->work, xmit_work_fn);
266	/* Increase refcount so the kfree_skb in dsa_user_xmit
267	 * won't really free the packet.
268	 */
269	xmit_work->dp = dp;
270	xmit_work->skb = skb_get(skb);
271
272	kthread_queue_work(xmit_worker, &xmit_work->work);
273
274	return NULL;
275}
276
277static struct sk_buff *ksz9477_xmit(struct sk_buff *skb,
278				    struct net_device *dev)
279{
280	u16 queue_mapping = skb_get_queue_mapping(skb);
281	u8 prio = netdev_txq_to_tc(dev, queue_mapping);
282	struct dsa_port *dp = dsa_user_to_port(dev);
283	struct ethhdr *hdr;
284	__be16 *tag;
285	u16 val;
286
287	if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
288		return NULL;
289
290	/* Tag encoding */
291	ksz_xmit_timestamp(dp, skb);
292
293	tag = skb_put(skb, KSZ9477_INGRESS_TAG_LEN);
294	hdr = skb_eth_hdr(skb);
295
296	val = dsa_xmit_port_mask(skb, dev);
297	val |= FIELD_PREP(KSZ9477_TAIL_TAG_PRIO, prio);
298
299	if (is_link_local_ether_addr(hdr->h_dest))
300		val |= KSZ9477_TAIL_TAG_OVERRIDE;
301
302	*tag = cpu_to_be16(val);
303
304	return ksz_defer_xmit(dp, skb);
305}
306
307static struct sk_buff *ksz9477_rcv(struct sk_buff *skb, struct net_device *dev)
308{
309	unsigned int len = KSZ_EGRESS_TAG_LEN;
310	unsigned int port;
311	u8 *tag;
312
313	if (skb_linearize(skb))
314		return NULL;
315
316	/* Tag decoding */
317	tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
318	port = tag[0] & KSZ9477_TAIL_TAG_EG_PORT_M;
319
320	/* Extra 4-bytes PTP timestamp */
321	if (tag[0] & KSZ9477_PTP_TAG_INDICATION) {
322		ksz_rcv_timestamp(skb, tag);
323		len += KSZ_PTP_TAG_LEN;
324	}
325
326	return ksz_common_rcv(skb, dev, port, len);
327}
328
329static const struct dsa_device_ops ksz9477_netdev_ops = {
330	.name	= KSZ9477_NAME,
331	.proto	= DSA_TAG_PROTO_KSZ9477,
332	.xmit	= ksz9477_xmit,
333	.rcv	= ksz9477_rcv,
334	.connect = ksz_connect,
335	.disconnect = ksz_disconnect,
336	.needed_tailroom = KSZ9477_INGRESS_TAG_LEN + KSZ_PTP_TAG_LEN,
337};
338
339DSA_TAG_DRIVER(ksz9477_netdev_ops);
340MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9477, KSZ9477_NAME);
341
342#define KSZ9893_TAIL_TAG_PRIO		GENMASK(4, 3)
343#define KSZ9893_TAIL_TAG_OVERRIDE	BIT(5)
344#define KSZ9893_TAIL_TAG_LOOKUP		BIT(6)
345
346static struct sk_buff *ksz9893_xmit(struct sk_buff *skb,
347				    struct net_device *dev)
348{
349	u16 queue_mapping = skb_get_queue_mapping(skb);
350	u8 prio = netdev_txq_to_tc(dev, queue_mapping);
351	struct dsa_port *dp = dsa_user_to_port(dev);
352	struct ethhdr *hdr;
353	u8 *tag;
354
355	if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
356		return NULL;
357
358	/* Tag encoding */
359	ksz_xmit_timestamp(dp, skb);
360
361	tag = skb_put(skb, KSZ_INGRESS_TAG_LEN);
362	hdr = skb_eth_hdr(skb);
363
364	*tag = dsa_xmit_port_mask(skb, dev);
365	*tag |= FIELD_PREP(KSZ9893_TAIL_TAG_PRIO, prio);
366
367	if (is_link_local_ether_addr(hdr->h_dest))
368		*tag |= KSZ9893_TAIL_TAG_OVERRIDE;
369
370	return ksz_defer_xmit(dp, skb);
371}
372
373static const struct dsa_device_ops ksz9893_netdev_ops = {
374	.name	= KSZ9893_NAME,
375	.proto	= DSA_TAG_PROTO_KSZ9893,
376	.xmit	= ksz9893_xmit,
377	.rcv	= ksz9477_rcv,
378	.connect = ksz_connect,
379	.disconnect = ksz_disconnect,
380	.needed_tailroom = KSZ_INGRESS_TAG_LEN + KSZ_PTP_TAG_LEN,
381};
382
383DSA_TAG_DRIVER(ksz9893_netdev_ops);
384MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9893, KSZ9893_NAME);
385
386/* For xmit, 2/6 bytes are added before FCS.
387 * ---------------------------------------------------------------------------
388 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|ts(4bytes)|tag0(1byte)|tag1(1byte)|
389 * FCS(4bytes)
390 * ---------------------------------------------------------------------------
391 * ts   : time stamp (Present only if PTP is enabled in the Hardware)
392 * tag0 : represents tag override, lookup and valid
393 * tag1 : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x80=port8)
394 *
395 * For rcv, 1/5 bytes is added before FCS.
396 * ---------------------------------------------------------------------------
397 * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|ts(4bytes)|tag0(1byte)|FCS(4bytes)
398 * ---------------------------------------------------------------------------
399 * ts   : time stamp (Present only if bit 7 of tag0 is set)
400 * tag0 : zero-based value represents port
401 *	  (eg, 0x00=port1, 0x02=port3, 0x07=port8)
402 */
403#define LAN937X_EGRESS_TAG_LEN		2
404
405#define LAN937X_TAIL_TAG_BLOCKING_OVERRIDE	BIT(11)
406#define LAN937X_TAIL_TAG_LOOKUP			BIT(12)
407#define LAN937X_TAIL_TAG_VALID			BIT(13)
408#define LAN937X_TAIL_TAG_PRIO			GENMASK(10, 8)
409#define LAN937X_TAIL_TAG_PORT_MASK		7
410
411static struct sk_buff *lan937x_xmit(struct sk_buff *skb,
412				    struct net_device *dev)
413{
414	u16 queue_mapping = skb_get_queue_mapping(skb);
415	u8 prio = netdev_txq_to_tc(dev, queue_mapping);
416	struct dsa_port *dp = dsa_user_to_port(dev);
417	const struct ethhdr *hdr = eth_hdr(skb);
418	__be16 *tag;
419	u16 val;
420
421	if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
422		return NULL;
423
424	ksz_xmit_timestamp(dp, skb);
425
426	tag = skb_put(skb, LAN937X_EGRESS_TAG_LEN);
427
428	val = dsa_xmit_port_mask(skb, dev);
429	val |= FIELD_PREP(LAN937X_TAIL_TAG_PRIO, prio);
430
431	if (is_link_local_ether_addr(hdr->h_dest))
432		val |= LAN937X_TAIL_TAG_BLOCKING_OVERRIDE;
433
434	/* Tail tag valid bit - This bit should always be set by the CPU */
435	val |= LAN937X_TAIL_TAG_VALID;
436
437	put_unaligned_be16(val, tag);
438
439	return ksz_defer_xmit(dp, skb);
440}
441
442static const struct dsa_device_ops lan937x_netdev_ops = {
443	.name	= LAN937X_NAME,
444	.proto	= DSA_TAG_PROTO_LAN937X,
445	.xmit	= lan937x_xmit,
446	.rcv	= ksz9477_rcv,
447	.connect = ksz_connect,
448	.disconnect = ksz_disconnect,
449	.needed_tailroom = LAN937X_EGRESS_TAG_LEN + KSZ_PTP_TAG_LEN,
450};
451
452DSA_TAG_DRIVER(lan937x_netdev_ops);
453MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_LAN937X, LAN937X_NAME);
454
455static struct dsa_tag_driver *dsa_tag_driver_array[] = {
456	&DSA_TAG_DRIVER_NAME(ksz8795_netdev_ops),
457	&DSA_TAG_DRIVER_NAME(ksz9477_netdev_ops),
458	&DSA_TAG_DRIVER_NAME(ksz9893_netdev_ops),
459	&DSA_TAG_DRIVER_NAME(lan937x_netdev_ops),
460};
461
462module_dsa_tag_drivers(dsa_tag_driver_array);
463
464MODULE_DESCRIPTION("DSA tag driver for Microchip 8795/937x/9477/9893 families of switches");
465MODULE_LICENSE("GPL");