xref: /linux/net/dsa/tag_ksz.c (revision 8f7aa3d3c7323f4ca2768a9e74ebbe359c4f8f88)
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 *
34 ksz_tagger_private(struct dsa_switch *ds)
35 {
36 	return ds->tagger_data;
37 }
38 
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 
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 
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_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 
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_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 
121 static 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 
140 static 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 
153 static 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 
161 DSA_TAG_DRIVER(ksz8795_netdev_ops);
162 MODULE_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 
192 static 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  */
204 static 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 
238 output_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.  */
243 static 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 
277 static 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 
307 static 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 
329 static 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 
339 DSA_TAG_DRIVER(ksz9477_netdev_ops);
340 MODULE_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 
346 static 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 
373 static 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 
383 DSA_TAG_DRIVER(ksz9893_netdev_ops);
384 MODULE_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 
411 static 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 
442 static 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 
452 DSA_TAG_DRIVER(lan937x_netdev_ops);
453 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_LAN937X, LAN937X_NAME);
454 
455 static 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 
462 module_dsa_tag_drivers(dsa_tag_driver_array);
463 
464 MODULE_DESCRIPTION("DSA tag driver for Microchip 8795/937x/9477/9893 families of switches");
465 MODULE_LICENSE("GPL");
466