xref: /openbmc/linux/net/dsa/tag_ksz.c (revision 499b2491)
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 
27 struct ksz_tagger_private {
28 	struct ksz_tagger_data data; /* Must be first */
29 	unsigned long state;
30 	struct kthread_worker *xmit_worker;
31 };
32 
33 static struct ksz_tagger_private *
ksz_tagger_private(struct dsa_switch * ds)34 ksz_tagger_private(struct dsa_switch *ds)
35 {
36 	return ds->tagger_data;
37 }
38 
ksz_hwtstamp_set_state(struct dsa_switch * ds,bool on)39 static 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 
ksz_disconnect(struct dsa_switch * ds)49 static 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 
ksz_connect(struct dsa_switch * ds)58 static 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_create_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 
ksz_common_rcv(struct sk_buff * skb,struct net_device * dev,unsigned int port,unsigned int len)86 static 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_master_find_slave(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, 0x00=port1, 0x02=port3, 0x06=port7)
115  */
116 
117 #define KSZ8795_TAIL_TAG_OVERRIDE	BIT(6)
118 #define KSZ8795_TAIL_TAG_LOOKUP		BIT(7)
119 
ksz8795_xmit(struct sk_buff * skb,struct net_device * dev)120 static struct sk_buff *ksz8795_xmit(struct sk_buff *skb, struct net_device *dev)
121 {
122 	struct dsa_port *dp = dsa_slave_to_port(dev);
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 = 1 << dp->index;
134 	if (is_link_local_ether_addr(hdr->h_dest))
135 		*tag |= KSZ8795_TAIL_TAG_OVERRIDE;
136 
137 	return skb;
138 }
139 
ksz8795_rcv(struct sk_buff * skb,struct net_device * dev)140 static struct sk_buff *ksz8795_rcv(struct sk_buff *skb, struct net_device *dev)
141 {
142 	u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
143 
144 	return ksz_common_rcv(skb, dev, tag[0] & 7, KSZ_EGRESS_TAG_LEN);
145 }
146 
147 static const struct dsa_device_ops ksz8795_netdev_ops = {
148 	.name	= KSZ8795_NAME,
149 	.proto	= DSA_TAG_PROTO_KSZ8795,
150 	.xmit	= ksz8795_xmit,
151 	.rcv	= ksz8795_rcv,
152 	.needed_tailroom = KSZ_INGRESS_TAG_LEN,
153 };
154 
155 DSA_TAG_DRIVER(ksz8795_netdev_ops);
156 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ8795, KSZ8795_NAME);
157 
158 /*
159  * For Ingress (Host -> KSZ9477), 2/6 bytes are added before FCS.
160  * ---------------------------------------------------------------------------
161  * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|ts(4bytes)|tag0(1byte)|tag1(1byte)|
162  * FCS(4bytes)
163  * ---------------------------------------------------------------------------
164  * ts   : time stamp (Present only if PTP is enabled in the Hardware)
165  * tag0 : Prioritization (not used now)
166  * tag1 : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x10=port5)
167  *
168  * For Egress (KSZ9477 -> Host), 1/5 bytes is added before FCS.
169  * ---------------------------------------------------------------------------
170  * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|ts(4bytes)|tag0(1byte)|FCS(4bytes)
171  * ---------------------------------------------------------------------------
172  * ts   : time stamp (Present only if bit 7 of tag0 is set)
173  * tag0 : zero-based value represents port
174  *	  (eg, 0x00=port1, 0x02=port3, 0x06=port7)
175  */
176 
177 #define KSZ9477_INGRESS_TAG_LEN		2
178 #define KSZ9477_PTP_TAG_LEN		4
179 #define KSZ9477_PTP_TAG_INDICATION	0x80
180 
181 #define KSZ9477_TAIL_TAG_PRIO		GENMASK(8, 7)
182 #define KSZ9477_TAIL_TAG_OVERRIDE	BIT(9)
183 #define KSZ9477_TAIL_TAG_LOOKUP		BIT(10)
184 
ksz_rcv_timestamp(struct sk_buff * skb,u8 * tag)185 static void ksz_rcv_timestamp(struct sk_buff *skb, u8 *tag)
186 {
187 	u8 *tstamp_raw = tag - KSZ_PTP_TAG_LEN;
188 	ktime_t tstamp;
189 
190 	tstamp = ksz_decode_tstamp(get_unaligned_be32(tstamp_raw));
191 	KSZ_SKB_CB(skb)->tstamp = tstamp;
192 }
193 
194 /* Time stamp tag *needs* to be inserted if PTP is enabled in hardware.
195  * Regardless of Whether it is a PTP frame or not.
196  */
ksz_xmit_timestamp(struct dsa_port * dp,struct sk_buff * skb)197 static void ksz_xmit_timestamp(struct dsa_port *dp, struct sk_buff *skb)
198 {
199 	struct ksz_tagger_private *priv;
200 	struct ptp_header *ptp_hdr;
201 	unsigned int ptp_type;
202 	u32 tstamp_raw = 0;
203 	s64 correction;
204 
205 	priv = ksz_tagger_private(dp->ds);
206 
207 	if (!test_bit(KSZ_HWTS_EN, &priv->state))
208 		return;
209 
210 	if (!KSZ_SKB_CB(skb)->update_correction)
211 		goto output_tag;
212 
213 	ptp_type = KSZ_SKB_CB(skb)->ptp_type;
214 
215 	ptp_hdr = ptp_parse_header(skb, ptp_type);
216 	if (!ptp_hdr)
217 		goto output_tag;
218 
219 	correction = (s64)get_unaligned_be64(&ptp_hdr->correction);
220 
221 	if (correction < 0) {
222 		struct timespec64 ts;
223 
224 		ts = ns_to_timespec64(-correction >> 16);
225 		tstamp_raw = ((ts.tv_sec & 3) << 30) | ts.tv_nsec;
226 
227 		/* Set correction field to 0 and update UDP checksum */
228 		ptp_header_update_correction(skb, ptp_type, ptp_hdr, 0);
229 	}
230 
231 output_tag:
232 	put_unaligned_be32(tstamp_raw, skb_put(skb, KSZ_PTP_TAG_LEN));
233 }
234 
235 /* Defer transmit if waiting for egress time stamp is required.  */
ksz_defer_xmit(struct dsa_port * dp,struct sk_buff * skb)236 static struct sk_buff *ksz_defer_xmit(struct dsa_port *dp, struct sk_buff *skb)
237 {
238 	struct ksz_tagger_data *tagger_data = ksz_tagger_data(dp->ds);
239 	struct ksz_tagger_private *priv = ksz_tagger_private(dp->ds);
240 	void (*xmit_work_fn)(struct kthread_work *work);
241 	struct sk_buff *clone = KSZ_SKB_CB(skb)->clone;
242 	struct ksz_deferred_xmit_work *xmit_work;
243 	struct kthread_worker *xmit_worker;
244 
245 	if (!clone)
246 		return skb;  /* no deferred xmit for this packet */
247 
248 	xmit_work_fn = tagger_data->xmit_work_fn;
249 	xmit_worker = priv->xmit_worker;
250 
251 	if (!xmit_work_fn || !xmit_worker)
252 		return NULL;
253 
254 	xmit_work = kzalloc(sizeof(*xmit_work), GFP_ATOMIC);
255 	if (!xmit_work)
256 		return NULL;
257 
258 	kthread_init_work(&xmit_work->work, xmit_work_fn);
259 	/* Increase refcount so the kfree_skb in dsa_slave_xmit
260 	 * won't really free the packet.
261 	 */
262 	xmit_work->dp = dp;
263 	xmit_work->skb = skb_get(skb);
264 
265 	kthread_queue_work(xmit_worker, &xmit_work->work);
266 
267 	return NULL;
268 }
269 
ksz9477_xmit(struct sk_buff * skb,struct net_device * dev)270 static struct sk_buff *ksz9477_xmit(struct sk_buff *skb,
271 				    struct net_device *dev)
272 {
273 	u16 queue_mapping = skb_get_queue_mapping(skb);
274 	u8 prio = netdev_txq_to_tc(dev, queue_mapping);
275 	struct dsa_port *dp = dsa_slave_to_port(dev);
276 	struct ethhdr *hdr;
277 	__be16 *tag;
278 	u16 val;
279 
280 	if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
281 		return NULL;
282 
283 	/* Tag encoding */
284 	ksz_xmit_timestamp(dp, skb);
285 
286 	tag = skb_put(skb, KSZ9477_INGRESS_TAG_LEN);
287 	hdr = skb_eth_hdr(skb);
288 
289 	val = BIT(dp->index);
290 
291 	val |= FIELD_PREP(KSZ9477_TAIL_TAG_PRIO, prio);
292 
293 	if (is_link_local_ether_addr(hdr->h_dest))
294 		val |= KSZ9477_TAIL_TAG_OVERRIDE;
295 
296 	*tag = cpu_to_be16(val);
297 
298 	return ksz_defer_xmit(dp, skb);
299 }
300 
ksz9477_rcv(struct sk_buff * skb,struct net_device * dev)301 static struct sk_buff *ksz9477_rcv(struct sk_buff *skb, struct net_device *dev)
302 {
303 	/* Tag decoding */
304 	u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
305 	unsigned int port = tag[0] & 7;
306 	unsigned int len = KSZ_EGRESS_TAG_LEN;
307 
308 	/* Extra 4-bytes PTP timestamp */
309 	if (tag[0] & KSZ9477_PTP_TAG_INDICATION) {
310 		ksz_rcv_timestamp(skb, tag);
311 		len += KSZ_PTP_TAG_LEN;
312 	}
313 
314 	return ksz_common_rcv(skb, dev, port, len);
315 }
316 
317 static const struct dsa_device_ops ksz9477_netdev_ops = {
318 	.name	= KSZ9477_NAME,
319 	.proto	= DSA_TAG_PROTO_KSZ9477,
320 	.xmit	= ksz9477_xmit,
321 	.rcv	= ksz9477_rcv,
322 	.connect = ksz_connect,
323 	.disconnect = ksz_disconnect,
324 	.needed_tailroom = KSZ9477_INGRESS_TAG_LEN + KSZ_PTP_TAG_LEN,
325 };
326 
327 DSA_TAG_DRIVER(ksz9477_netdev_ops);
328 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9477, KSZ9477_NAME);
329 
330 #define KSZ9893_TAIL_TAG_PRIO		GENMASK(4, 3)
331 #define KSZ9893_TAIL_TAG_OVERRIDE	BIT(5)
332 #define KSZ9893_TAIL_TAG_LOOKUP		BIT(6)
333 
ksz9893_xmit(struct sk_buff * skb,struct net_device * dev)334 static struct sk_buff *ksz9893_xmit(struct sk_buff *skb,
335 				    struct net_device *dev)
336 {
337 	u16 queue_mapping = skb_get_queue_mapping(skb);
338 	u8 prio = netdev_txq_to_tc(dev, queue_mapping);
339 	struct dsa_port *dp = dsa_slave_to_port(dev);
340 	struct ethhdr *hdr;
341 	u8 *tag;
342 
343 	if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
344 		return NULL;
345 
346 	/* Tag encoding */
347 	ksz_xmit_timestamp(dp, skb);
348 
349 	tag = skb_put(skb, KSZ_INGRESS_TAG_LEN);
350 	hdr = skb_eth_hdr(skb);
351 
352 	*tag = BIT(dp->index);
353 
354 	*tag |= FIELD_PREP(KSZ9893_TAIL_TAG_PRIO, prio);
355 
356 	if (is_link_local_ether_addr(hdr->h_dest))
357 		*tag |= KSZ9893_TAIL_TAG_OVERRIDE;
358 
359 	return ksz_defer_xmit(dp, skb);
360 }
361 
362 static const struct dsa_device_ops ksz9893_netdev_ops = {
363 	.name	= KSZ9893_NAME,
364 	.proto	= DSA_TAG_PROTO_KSZ9893,
365 	.xmit	= ksz9893_xmit,
366 	.rcv	= ksz9477_rcv,
367 	.connect = ksz_connect,
368 	.disconnect = ksz_disconnect,
369 	.needed_tailroom = KSZ_INGRESS_TAG_LEN + KSZ_PTP_TAG_LEN,
370 };
371 
372 DSA_TAG_DRIVER(ksz9893_netdev_ops);
373 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9893, KSZ9893_NAME);
374 
375 /* For xmit, 2/6 bytes are added before FCS.
376  * ---------------------------------------------------------------------------
377  * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|ts(4bytes)|tag0(1byte)|tag1(1byte)|
378  * FCS(4bytes)
379  * ---------------------------------------------------------------------------
380  * ts   : time stamp (Present only if PTP is enabled in the Hardware)
381  * tag0 : represents tag override, lookup and valid
382  * tag1 : each bit represents port (eg, 0x01=port1, 0x02=port2, 0x80=port8)
383  *
384  * For rcv, 1/5 bytes is added before FCS.
385  * ---------------------------------------------------------------------------
386  * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|ts(4bytes)|tag0(1byte)|FCS(4bytes)
387  * ---------------------------------------------------------------------------
388  * ts   : time stamp (Present only if bit 7 of tag0 is set)
389  * tag0 : zero-based value represents port
390  *	  (eg, 0x00=port1, 0x02=port3, 0x07=port8)
391  */
392 #define LAN937X_EGRESS_TAG_LEN		2
393 
394 #define LAN937X_TAIL_TAG_BLOCKING_OVERRIDE	BIT(11)
395 #define LAN937X_TAIL_TAG_LOOKUP			BIT(12)
396 #define LAN937X_TAIL_TAG_VALID			BIT(13)
397 #define LAN937X_TAIL_TAG_PRIO			GENMASK(10, 8)
398 #define LAN937X_TAIL_TAG_PORT_MASK		7
399 
lan937x_xmit(struct sk_buff * skb,struct net_device * dev)400 static struct sk_buff *lan937x_xmit(struct sk_buff *skb,
401 				    struct net_device *dev)
402 {
403 	u16 queue_mapping = skb_get_queue_mapping(skb);
404 	u8 prio = netdev_txq_to_tc(dev, queue_mapping);
405 	struct dsa_port *dp = dsa_slave_to_port(dev);
406 	const struct ethhdr *hdr = eth_hdr(skb);
407 	__be16 *tag;
408 	u16 val;
409 
410 	if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
411 		return NULL;
412 
413 	ksz_xmit_timestamp(dp, skb);
414 
415 	tag = skb_put(skb, LAN937X_EGRESS_TAG_LEN);
416 
417 	val = BIT(dp->index);
418 
419 	val |= FIELD_PREP(LAN937X_TAIL_TAG_PRIO, prio);
420 
421 	if (is_link_local_ether_addr(hdr->h_dest))
422 		val |= LAN937X_TAIL_TAG_BLOCKING_OVERRIDE;
423 
424 	/* Tail tag valid bit - This bit should always be set by the CPU */
425 	val |= LAN937X_TAIL_TAG_VALID;
426 
427 	put_unaligned_be16(val, tag);
428 
429 	return ksz_defer_xmit(dp, skb);
430 }
431 
432 static const struct dsa_device_ops lan937x_netdev_ops = {
433 	.name	= LAN937X_NAME,
434 	.proto	= DSA_TAG_PROTO_LAN937X,
435 	.xmit	= lan937x_xmit,
436 	.rcv	= ksz9477_rcv,
437 	.connect = ksz_connect,
438 	.disconnect = ksz_disconnect,
439 	.needed_tailroom = LAN937X_EGRESS_TAG_LEN + KSZ_PTP_TAG_LEN,
440 };
441 
442 DSA_TAG_DRIVER(lan937x_netdev_ops);
443 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_LAN937X, LAN937X_NAME);
444 
445 static struct dsa_tag_driver *dsa_tag_driver_array[] = {
446 	&DSA_TAG_DRIVER_NAME(ksz8795_netdev_ops),
447 	&DSA_TAG_DRIVER_NAME(ksz9477_netdev_ops),
448 	&DSA_TAG_DRIVER_NAME(ksz9893_netdev_ops),
449 	&DSA_TAG_DRIVER_NAME(lan937x_netdev_ops),
450 };
451 
452 module_dsa_tag_drivers(dsa_tag_driver_array);
453 
454 MODULE_LICENSE("GPL");
455