1 // SPDX-License-Identifier: GPL-2.0+
2 
3 #include "lan966x_main.h"
4 
5 static int lan966x_fdma_channel_active(struct lan966x *lan966x)
6 {
7 	return lan_rd(lan966x, FDMA_CH_ACTIVE);
8 }
9 
10 static struct page *lan966x_fdma_rx_alloc_page(struct lan966x_rx *rx,
11 					       struct lan966x_db *db)
12 {
13 	struct lan966x *lan966x = rx->lan966x;
14 	dma_addr_t dma_addr;
15 	struct page *page;
16 
17 	page = dev_alloc_pages(rx->page_order);
18 	if (unlikely(!page))
19 		return NULL;
20 
21 	dma_addr = dma_map_page(lan966x->dev, page, 0,
22 				PAGE_SIZE << rx->page_order,
23 				DMA_FROM_DEVICE);
24 	if (unlikely(dma_mapping_error(lan966x->dev, dma_addr)))
25 		goto free_page;
26 
27 	db->dataptr = dma_addr;
28 
29 	return page;
30 
31 free_page:
32 	__free_pages(page, rx->page_order);
33 	return NULL;
34 }
35 
36 static void lan966x_fdma_rx_free_pages(struct lan966x_rx *rx)
37 {
38 	struct lan966x *lan966x = rx->lan966x;
39 	struct lan966x_rx_dcb *dcb;
40 	struct lan966x_db *db;
41 	int i, j;
42 
43 	for (i = 0; i < FDMA_DCB_MAX; ++i) {
44 		dcb = &rx->dcbs[i];
45 
46 		for (j = 0; j < FDMA_RX_DCB_MAX_DBS; ++j) {
47 			db = &dcb->db[j];
48 			dma_unmap_single(lan966x->dev,
49 					 (dma_addr_t)db->dataptr,
50 					 PAGE_SIZE << rx->page_order,
51 					 DMA_FROM_DEVICE);
52 			__free_pages(rx->page[i][j], rx->page_order);
53 		}
54 	}
55 }
56 
57 static void lan966x_fdma_rx_add_dcb(struct lan966x_rx *rx,
58 				    struct lan966x_rx_dcb *dcb,
59 				    u64 nextptr)
60 {
61 	struct lan966x_db *db;
62 	int i;
63 
64 	for (i = 0; i < FDMA_RX_DCB_MAX_DBS; ++i) {
65 		db = &dcb->db[i];
66 		db->status = FDMA_DCB_STATUS_INTR;
67 	}
68 
69 	dcb->nextptr = FDMA_DCB_INVALID_DATA;
70 	dcb->info = FDMA_DCB_INFO_DATAL(PAGE_SIZE << rx->page_order);
71 
72 	rx->last_entry->nextptr = nextptr;
73 	rx->last_entry = dcb;
74 }
75 
76 static int lan966x_fdma_rx_alloc(struct lan966x_rx *rx)
77 {
78 	struct lan966x *lan966x = rx->lan966x;
79 	struct lan966x_rx_dcb *dcb;
80 	struct lan966x_db *db;
81 	struct page *page;
82 	int i, j;
83 	int size;
84 
85 	/* calculate how many pages are needed to allocate the dcbs */
86 	size = sizeof(struct lan966x_rx_dcb) * FDMA_DCB_MAX;
87 	size = ALIGN(size, PAGE_SIZE);
88 
89 	rx->dcbs = dma_alloc_coherent(lan966x->dev, size, &rx->dma, GFP_KERNEL);
90 	if (!rx->dcbs)
91 		return -ENOMEM;
92 
93 	rx->last_entry = rx->dcbs;
94 	rx->db_index = 0;
95 	rx->dcb_index = 0;
96 
97 	/* Now for each dcb allocate the dbs */
98 	for (i = 0; i < FDMA_DCB_MAX; ++i) {
99 		dcb = &rx->dcbs[i];
100 		dcb->info = 0;
101 
102 		/* For each db allocate a page and map it to the DB dataptr. */
103 		for (j = 0; j < FDMA_RX_DCB_MAX_DBS; ++j) {
104 			db = &dcb->db[j];
105 			page = lan966x_fdma_rx_alloc_page(rx, db);
106 			if (!page)
107 				return -ENOMEM;
108 
109 			db->status = 0;
110 			rx->page[i][j] = page;
111 		}
112 
113 		lan966x_fdma_rx_add_dcb(rx, dcb, rx->dma + sizeof(*dcb) * i);
114 	}
115 
116 	return 0;
117 }
118 
119 static void lan966x_fdma_rx_free(struct lan966x_rx *rx)
120 {
121 	struct lan966x *lan966x = rx->lan966x;
122 	u32 size;
123 
124 	/* Now it is possible to do the cleanup of dcb */
125 	size = sizeof(struct lan966x_tx_dcb) * FDMA_DCB_MAX;
126 	size = ALIGN(size, PAGE_SIZE);
127 	dma_free_coherent(lan966x->dev, size, rx->dcbs, rx->dma);
128 }
129 
130 static void lan966x_fdma_rx_start(struct lan966x_rx *rx)
131 {
132 	struct lan966x *lan966x = rx->lan966x;
133 	u32 mask;
134 
135 	/* When activating a channel, first is required to write the first DCB
136 	 * address and then to activate it
137 	 */
138 	lan_wr(lower_32_bits((u64)rx->dma), lan966x,
139 	       FDMA_DCB_LLP(rx->channel_id));
140 	lan_wr(upper_32_bits((u64)rx->dma), lan966x,
141 	       FDMA_DCB_LLP1(rx->channel_id));
142 
143 	lan_wr(FDMA_CH_CFG_CH_DCB_DB_CNT_SET(FDMA_RX_DCB_MAX_DBS) |
144 	       FDMA_CH_CFG_CH_INTR_DB_EOF_ONLY_SET(1) |
145 	       FDMA_CH_CFG_CH_INJ_PORT_SET(0) |
146 	       FDMA_CH_CFG_CH_MEM_SET(1),
147 	       lan966x, FDMA_CH_CFG(rx->channel_id));
148 
149 	/* Start fdma */
150 	lan_rmw(FDMA_PORT_CTRL_XTR_STOP_SET(0),
151 		FDMA_PORT_CTRL_XTR_STOP,
152 		lan966x, FDMA_PORT_CTRL(0));
153 
154 	/* Enable interrupts */
155 	mask = lan_rd(lan966x, FDMA_INTR_DB_ENA);
156 	mask = FDMA_INTR_DB_ENA_INTR_DB_ENA_GET(mask);
157 	mask |= BIT(rx->channel_id);
158 	lan_rmw(FDMA_INTR_DB_ENA_INTR_DB_ENA_SET(mask),
159 		FDMA_INTR_DB_ENA_INTR_DB_ENA,
160 		lan966x, FDMA_INTR_DB_ENA);
161 
162 	/* Activate the channel */
163 	lan_rmw(FDMA_CH_ACTIVATE_CH_ACTIVATE_SET(BIT(rx->channel_id)),
164 		FDMA_CH_ACTIVATE_CH_ACTIVATE,
165 		lan966x, FDMA_CH_ACTIVATE);
166 }
167 
168 static void lan966x_fdma_rx_disable(struct lan966x_rx *rx)
169 {
170 	struct lan966x *lan966x = rx->lan966x;
171 	u32 val;
172 
173 	/* Disable the channel */
174 	lan_rmw(FDMA_CH_DISABLE_CH_DISABLE_SET(BIT(rx->channel_id)),
175 		FDMA_CH_DISABLE_CH_DISABLE,
176 		lan966x, FDMA_CH_DISABLE);
177 
178 	readx_poll_timeout_atomic(lan966x_fdma_channel_active, lan966x,
179 				  val, !(val & BIT(rx->channel_id)),
180 				  READL_SLEEP_US, READL_TIMEOUT_US);
181 
182 	lan_rmw(FDMA_CH_DB_DISCARD_DB_DISCARD_SET(BIT(rx->channel_id)),
183 		FDMA_CH_DB_DISCARD_DB_DISCARD,
184 		lan966x, FDMA_CH_DB_DISCARD);
185 }
186 
187 static void lan966x_fdma_rx_reload(struct lan966x_rx *rx)
188 {
189 	struct lan966x *lan966x = rx->lan966x;
190 
191 	lan_rmw(FDMA_CH_RELOAD_CH_RELOAD_SET(BIT(rx->channel_id)),
192 		FDMA_CH_RELOAD_CH_RELOAD,
193 		lan966x, FDMA_CH_RELOAD);
194 }
195 
196 static void lan966x_fdma_tx_add_dcb(struct lan966x_tx *tx,
197 				    struct lan966x_tx_dcb *dcb)
198 {
199 	dcb->nextptr = FDMA_DCB_INVALID_DATA;
200 	dcb->info = 0;
201 }
202 
203 static int lan966x_fdma_tx_alloc(struct lan966x_tx *tx)
204 {
205 	struct lan966x *lan966x = tx->lan966x;
206 	struct lan966x_tx_dcb *dcb;
207 	struct lan966x_db *db;
208 	int size;
209 	int i, j;
210 
211 	tx->dcbs_buf = kcalloc(FDMA_DCB_MAX, sizeof(struct lan966x_tx_dcb_buf),
212 			       GFP_KERNEL);
213 	if (!tx->dcbs_buf)
214 		return -ENOMEM;
215 
216 	/* calculate how many pages are needed to allocate the dcbs */
217 	size = sizeof(struct lan966x_tx_dcb) * FDMA_DCB_MAX;
218 	size = ALIGN(size, PAGE_SIZE);
219 	tx->dcbs = dma_alloc_coherent(lan966x->dev, size, &tx->dma, GFP_KERNEL);
220 	if (!tx->dcbs)
221 		goto out;
222 
223 	/* Now for each dcb allocate the db */
224 	for (i = 0; i < FDMA_DCB_MAX; ++i) {
225 		dcb = &tx->dcbs[i];
226 
227 		for (j = 0; j < FDMA_TX_DCB_MAX_DBS; ++j) {
228 			db = &dcb->db[j];
229 			db->dataptr = 0;
230 			db->status = 0;
231 		}
232 
233 		lan966x_fdma_tx_add_dcb(tx, dcb);
234 	}
235 
236 	return 0;
237 
238 out:
239 	kfree(tx->dcbs_buf);
240 	return -ENOMEM;
241 }
242 
243 static void lan966x_fdma_tx_free(struct lan966x_tx *tx)
244 {
245 	struct lan966x *lan966x = tx->lan966x;
246 	int size;
247 
248 	kfree(tx->dcbs_buf);
249 
250 	size = sizeof(struct lan966x_tx_dcb) * FDMA_DCB_MAX;
251 	size = ALIGN(size, PAGE_SIZE);
252 	dma_free_coherent(lan966x->dev, size, tx->dcbs, tx->dma);
253 }
254 
255 static void lan966x_fdma_tx_activate(struct lan966x_tx *tx)
256 {
257 	struct lan966x *lan966x = tx->lan966x;
258 	u32 mask;
259 
260 	/* When activating a channel, first is required to write the first DCB
261 	 * address and then to activate it
262 	 */
263 	lan_wr(lower_32_bits((u64)tx->dma), lan966x,
264 	       FDMA_DCB_LLP(tx->channel_id));
265 	lan_wr(upper_32_bits((u64)tx->dma), lan966x,
266 	       FDMA_DCB_LLP1(tx->channel_id));
267 
268 	lan_wr(FDMA_CH_CFG_CH_DCB_DB_CNT_SET(FDMA_TX_DCB_MAX_DBS) |
269 	       FDMA_CH_CFG_CH_INTR_DB_EOF_ONLY_SET(1) |
270 	       FDMA_CH_CFG_CH_INJ_PORT_SET(0) |
271 	       FDMA_CH_CFG_CH_MEM_SET(1),
272 	       lan966x, FDMA_CH_CFG(tx->channel_id));
273 
274 	/* Start fdma */
275 	lan_rmw(FDMA_PORT_CTRL_INJ_STOP_SET(0),
276 		FDMA_PORT_CTRL_INJ_STOP,
277 		lan966x, FDMA_PORT_CTRL(0));
278 
279 	/* Enable interrupts */
280 	mask = lan_rd(lan966x, FDMA_INTR_DB_ENA);
281 	mask = FDMA_INTR_DB_ENA_INTR_DB_ENA_GET(mask);
282 	mask |= BIT(tx->channel_id);
283 	lan_rmw(FDMA_INTR_DB_ENA_INTR_DB_ENA_SET(mask),
284 		FDMA_INTR_DB_ENA_INTR_DB_ENA,
285 		lan966x, FDMA_INTR_DB_ENA);
286 
287 	/* Activate the channel */
288 	lan_rmw(FDMA_CH_ACTIVATE_CH_ACTIVATE_SET(BIT(tx->channel_id)),
289 		FDMA_CH_ACTIVATE_CH_ACTIVATE,
290 		lan966x, FDMA_CH_ACTIVATE);
291 }
292 
293 static void lan966x_fdma_tx_disable(struct lan966x_tx *tx)
294 {
295 	struct lan966x *lan966x = tx->lan966x;
296 	u32 val;
297 
298 	/* Disable the channel */
299 	lan_rmw(FDMA_CH_DISABLE_CH_DISABLE_SET(BIT(tx->channel_id)),
300 		FDMA_CH_DISABLE_CH_DISABLE,
301 		lan966x, FDMA_CH_DISABLE);
302 
303 	readx_poll_timeout_atomic(lan966x_fdma_channel_active, lan966x,
304 				  val, !(val & BIT(tx->channel_id)),
305 				  READL_SLEEP_US, READL_TIMEOUT_US);
306 
307 	lan_rmw(FDMA_CH_DB_DISCARD_DB_DISCARD_SET(BIT(tx->channel_id)),
308 		FDMA_CH_DB_DISCARD_DB_DISCARD,
309 		lan966x, FDMA_CH_DB_DISCARD);
310 
311 	tx->activated = false;
312 	tx->last_in_use = -1;
313 }
314 
315 static void lan966x_fdma_tx_reload(struct lan966x_tx *tx)
316 {
317 	struct lan966x *lan966x = tx->lan966x;
318 
319 	/* Write the registers to reload the channel */
320 	lan_rmw(FDMA_CH_RELOAD_CH_RELOAD_SET(BIT(tx->channel_id)),
321 		FDMA_CH_RELOAD_CH_RELOAD,
322 		lan966x, FDMA_CH_RELOAD);
323 }
324 
325 static void lan966x_fdma_wakeup_netdev(struct lan966x *lan966x)
326 {
327 	struct lan966x_port *port;
328 	int i;
329 
330 	for (i = 0; i < lan966x->num_phys_ports; ++i) {
331 		port = lan966x->ports[i];
332 		if (!port)
333 			continue;
334 
335 		if (netif_queue_stopped(port->dev))
336 			netif_wake_queue(port->dev);
337 	}
338 }
339 
340 static void lan966x_fdma_stop_netdev(struct lan966x *lan966x)
341 {
342 	struct lan966x_port *port;
343 	int i;
344 
345 	for (i = 0; i < lan966x->num_phys_ports; ++i) {
346 		port = lan966x->ports[i];
347 		if (!port)
348 			continue;
349 
350 		netif_stop_queue(port->dev);
351 	}
352 }
353 
354 static void lan966x_fdma_tx_clear_buf(struct lan966x *lan966x, int weight)
355 {
356 	struct lan966x_tx *tx = &lan966x->tx;
357 	struct lan966x_tx_dcb_buf *dcb_buf;
358 	struct lan966x_db *db;
359 	unsigned long flags;
360 	bool clear = false;
361 	int i;
362 
363 	spin_lock_irqsave(&lan966x->tx_lock, flags);
364 	for (i = 0; i < FDMA_DCB_MAX; ++i) {
365 		dcb_buf = &tx->dcbs_buf[i];
366 
367 		if (!dcb_buf->used)
368 			continue;
369 
370 		db = &tx->dcbs[i].db[0];
371 		if (!(db->status & FDMA_DCB_STATUS_DONE))
372 			continue;
373 
374 		dcb_buf->dev->stats.tx_packets++;
375 		dcb_buf->dev->stats.tx_bytes += dcb_buf->skb->len;
376 
377 		dcb_buf->used = false;
378 		dma_unmap_single(lan966x->dev,
379 				 dcb_buf->dma_addr,
380 				 dcb_buf->skb->len,
381 				 DMA_TO_DEVICE);
382 		if (!dcb_buf->ptp)
383 			dev_kfree_skb_any(dcb_buf->skb);
384 
385 		clear = true;
386 	}
387 
388 	if (clear)
389 		lan966x_fdma_wakeup_netdev(lan966x);
390 
391 	spin_unlock_irqrestore(&lan966x->tx_lock, flags);
392 }
393 
394 static bool lan966x_fdma_rx_more_frames(struct lan966x_rx *rx)
395 {
396 	struct lan966x_db *db;
397 
398 	/* Check if there is any data */
399 	db = &rx->dcbs[rx->dcb_index].db[rx->db_index];
400 	if (unlikely(!(db->status & FDMA_DCB_STATUS_DONE)))
401 		return false;
402 
403 	return true;
404 }
405 
406 static struct sk_buff *lan966x_fdma_rx_get_frame(struct lan966x_rx *rx)
407 {
408 	struct lan966x *lan966x = rx->lan966x;
409 	u64 src_port, timestamp;
410 	struct lan966x_db *db;
411 	struct sk_buff *skb;
412 	struct page *page;
413 
414 	/* Get the received frame and unmap it */
415 	db = &rx->dcbs[rx->dcb_index].db[rx->db_index];
416 	page = rx->page[rx->dcb_index][rx->db_index];
417 	skb = build_skb(page_address(page), PAGE_SIZE << rx->page_order);
418 	if (unlikely(!skb))
419 		goto unmap_page;
420 
421 	dma_unmap_single(lan966x->dev, (dma_addr_t)db->dataptr,
422 			 FDMA_DCB_STATUS_BLOCKL(db->status),
423 			 DMA_FROM_DEVICE);
424 	skb_put(skb, FDMA_DCB_STATUS_BLOCKL(db->status));
425 
426 	lan966x_ifh_get_src_port(skb->data, &src_port);
427 	lan966x_ifh_get_timestamp(skb->data, &timestamp);
428 
429 	if (WARN_ON(src_port >= lan966x->num_phys_ports))
430 		goto free_skb;
431 
432 	skb->dev = lan966x->ports[src_port]->dev;
433 	skb_pull(skb, IFH_LEN * sizeof(u32));
434 
435 	if (likely(!(skb->dev->features & NETIF_F_RXFCS)))
436 		skb_trim(skb, skb->len - ETH_FCS_LEN);
437 
438 	lan966x_ptp_rxtstamp(lan966x, skb, timestamp);
439 	skb->protocol = eth_type_trans(skb, skb->dev);
440 
441 	if (lan966x->bridge_mask & BIT(src_port)) {
442 		skb->offload_fwd_mark = 1;
443 
444 		skb_reset_network_header(skb);
445 		if (!lan966x_hw_offload(lan966x, src_port, skb))
446 			skb->offload_fwd_mark = 0;
447 	}
448 
449 	skb->dev->stats.rx_bytes += skb->len;
450 	skb->dev->stats.rx_packets++;
451 
452 	return skb;
453 
454 free_skb:
455 	kfree_skb(skb);
456 unmap_page:
457 	dma_unmap_page(lan966x->dev, (dma_addr_t)db->dataptr,
458 		       FDMA_DCB_STATUS_BLOCKL(db->status),
459 		       DMA_FROM_DEVICE);
460 	__free_pages(page, rx->page_order);
461 
462 	return NULL;
463 }
464 
465 static int lan966x_fdma_napi_poll(struct napi_struct *napi, int weight)
466 {
467 	struct lan966x *lan966x = container_of(napi, struct lan966x, napi);
468 	struct lan966x_rx *rx = &lan966x->rx;
469 	int dcb_reload = rx->dcb_index;
470 	struct lan966x_rx_dcb *old_dcb;
471 	struct lan966x_db *db;
472 	struct sk_buff *skb;
473 	struct page *page;
474 	int counter = 0;
475 	u64 nextptr;
476 
477 	lan966x_fdma_tx_clear_buf(lan966x, weight);
478 
479 	/* Get all received skb */
480 	while (counter < weight) {
481 		if (!lan966x_fdma_rx_more_frames(rx))
482 			break;
483 
484 		skb = lan966x_fdma_rx_get_frame(rx);
485 
486 		rx->page[rx->dcb_index][rx->db_index] = NULL;
487 		rx->dcb_index++;
488 		rx->dcb_index &= FDMA_DCB_MAX - 1;
489 
490 		if (!skb)
491 			break;
492 
493 		napi_gro_receive(&lan966x->napi, skb);
494 		counter++;
495 	}
496 
497 	/* Allocate new pages and map them */
498 	while (dcb_reload != rx->dcb_index) {
499 		db = &rx->dcbs[dcb_reload].db[rx->db_index];
500 		page = lan966x_fdma_rx_alloc_page(rx, db);
501 		if (unlikely(!page))
502 			break;
503 		rx->page[dcb_reload][rx->db_index] = page;
504 
505 		old_dcb = &rx->dcbs[dcb_reload];
506 		dcb_reload++;
507 		dcb_reload &= FDMA_DCB_MAX - 1;
508 
509 		nextptr = rx->dma + ((unsigned long)old_dcb -
510 				     (unsigned long)rx->dcbs);
511 		lan966x_fdma_rx_add_dcb(rx, old_dcb, nextptr);
512 		lan966x_fdma_rx_reload(rx);
513 	}
514 
515 	if (counter < weight && napi_complete_done(napi, counter))
516 		lan_wr(0xff, lan966x, FDMA_INTR_DB_ENA);
517 
518 	return counter;
519 }
520 
521 irqreturn_t lan966x_fdma_irq_handler(int irq, void *args)
522 {
523 	struct lan966x *lan966x = args;
524 	u32 db, err, err_type;
525 
526 	db = lan_rd(lan966x, FDMA_INTR_DB);
527 	err = lan_rd(lan966x, FDMA_INTR_ERR);
528 
529 	if (db) {
530 		lan_wr(0, lan966x, FDMA_INTR_DB_ENA);
531 		lan_wr(db, lan966x, FDMA_INTR_DB);
532 
533 		napi_schedule(&lan966x->napi);
534 	}
535 
536 	if (err) {
537 		err_type = lan_rd(lan966x, FDMA_ERRORS);
538 
539 		WARN(1, "Unexpected error: %d, error_type: %d\n", err, err_type);
540 
541 		lan_wr(err, lan966x, FDMA_INTR_ERR);
542 		lan_wr(err_type, lan966x, FDMA_ERRORS);
543 	}
544 
545 	return IRQ_HANDLED;
546 }
547 
548 static int lan966x_fdma_get_next_dcb(struct lan966x_tx *tx)
549 {
550 	struct lan966x_tx_dcb_buf *dcb_buf;
551 	int i;
552 
553 	for (i = 0; i < FDMA_DCB_MAX; ++i) {
554 		dcb_buf = &tx->dcbs_buf[i];
555 		if (!dcb_buf->used && i != tx->last_in_use)
556 			return i;
557 	}
558 
559 	return -1;
560 }
561 
562 int lan966x_fdma_xmit(struct sk_buff *skb, __be32 *ifh, struct net_device *dev)
563 {
564 	struct lan966x_port *port = netdev_priv(dev);
565 	struct lan966x *lan966x = port->lan966x;
566 	struct lan966x_tx_dcb_buf *next_dcb_buf;
567 	struct lan966x_tx_dcb *next_dcb, *dcb;
568 	struct lan966x_tx *tx = &lan966x->tx;
569 	struct lan966x_db *next_db;
570 	int needed_headroom;
571 	int needed_tailroom;
572 	dma_addr_t dma_addr;
573 	int next_to_use;
574 	int err;
575 
576 	/* Get next index */
577 	next_to_use = lan966x_fdma_get_next_dcb(tx);
578 	if (next_to_use < 0) {
579 		netif_stop_queue(dev);
580 		return NETDEV_TX_BUSY;
581 	}
582 
583 	if (skb_put_padto(skb, ETH_ZLEN)) {
584 		dev->stats.tx_dropped++;
585 		return NETDEV_TX_OK;
586 	}
587 
588 	/* skb processing */
589 	needed_headroom = max_t(int, IFH_LEN * sizeof(u32) - skb_headroom(skb), 0);
590 	needed_tailroom = max_t(int, ETH_FCS_LEN - skb_tailroom(skb), 0);
591 	if (needed_headroom || needed_tailroom || skb_header_cloned(skb)) {
592 		err = pskb_expand_head(skb, needed_headroom, needed_tailroom,
593 				       GFP_ATOMIC);
594 		if (unlikely(err)) {
595 			dev->stats.tx_dropped++;
596 			err = NETDEV_TX_OK;
597 			goto release;
598 		}
599 	}
600 
601 	skb_tx_timestamp(skb);
602 	skb_push(skb, IFH_LEN * sizeof(u32));
603 	memcpy(skb->data, ifh, IFH_LEN * sizeof(u32));
604 	skb_put(skb, 4);
605 
606 	dma_addr = dma_map_single(lan966x->dev, skb->data, skb->len,
607 				  DMA_TO_DEVICE);
608 	if (dma_mapping_error(lan966x->dev, dma_addr)) {
609 		dev->stats.tx_dropped++;
610 		err = NETDEV_TX_OK;
611 		goto release;
612 	}
613 
614 	/* Setup next dcb */
615 	next_dcb = &tx->dcbs[next_to_use];
616 	next_dcb->nextptr = FDMA_DCB_INVALID_DATA;
617 
618 	next_db = &next_dcb->db[0];
619 	next_db->dataptr = dma_addr;
620 	next_db->status = FDMA_DCB_STATUS_SOF |
621 			  FDMA_DCB_STATUS_EOF |
622 			  FDMA_DCB_STATUS_INTR |
623 			  FDMA_DCB_STATUS_BLOCKO(0) |
624 			  FDMA_DCB_STATUS_BLOCKL(skb->len);
625 
626 	/* Fill up the buffer */
627 	next_dcb_buf = &tx->dcbs_buf[next_to_use];
628 	next_dcb_buf->skb = skb;
629 	next_dcb_buf->dma_addr = dma_addr;
630 	next_dcb_buf->used = true;
631 	next_dcb_buf->ptp = false;
632 	next_dcb_buf->dev = dev;
633 
634 	if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP &&
635 	    LAN966X_SKB_CB(skb)->rew_op == IFH_REW_OP_TWO_STEP_PTP)
636 		next_dcb_buf->ptp = true;
637 
638 	if (likely(lan966x->tx.activated)) {
639 		/* Connect current dcb to the next db */
640 		dcb = &tx->dcbs[tx->last_in_use];
641 		dcb->nextptr = tx->dma + (next_to_use *
642 					  sizeof(struct lan966x_tx_dcb));
643 
644 		lan966x_fdma_tx_reload(tx);
645 	} else {
646 		/* Because it is first time, then just activate */
647 		lan966x->tx.activated = true;
648 		lan966x_fdma_tx_activate(tx);
649 	}
650 
651 	/* Move to next dcb because this last in use */
652 	tx->last_in_use = next_to_use;
653 
654 	return NETDEV_TX_OK;
655 
656 release:
657 	if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP &&
658 	    LAN966X_SKB_CB(skb)->rew_op == IFH_REW_OP_TWO_STEP_PTP)
659 		lan966x_ptp_txtstamp_release(port, skb);
660 
661 	dev_kfree_skb_any(skb);
662 	return err;
663 }
664 
665 static int lan966x_fdma_get_max_mtu(struct lan966x *lan966x)
666 {
667 	int max_mtu = 0;
668 	int i;
669 
670 	for (i = 0; i < lan966x->num_phys_ports; ++i) {
671 		int mtu;
672 
673 		if (!lan966x->ports[i])
674 			continue;
675 
676 		mtu = lan966x->ports[i]->dev->mtu;
677 		if (mtu > max_mtu)
678 			max_mtu = mtu;
679 	}
680 
681 	return max_mtu;
682 }
683 
684 static int lan966x_qsys_sw_status(struct lan966x *lan966x)
685 {
686 	return lan_rd(lan966x, QSYS_SW_STATUS(CPU_PORT));
687 }
688 
689 static int lan966x_fdma_reload(struct lan966x *lan966x, int new_mtu)
690 {
691 	dma_addr_t rx_dma;
692 	void *rx_dcbs;
693 	u32 size;
694 	int err;
695 
696 	/* Store these for later to free them */
697 	rx_dma = lan966x->rx.dma;
698 	rx_dcbs = lan966x->rx.dcbs;
699 
700 	napi_synchronize(&lan966x->napi);
701 	napi_disable(&lan966x->napi);
702 	lan966x_fdma_stop_netdev(lan966x);
703 
704 	lan966x_fdma_rx_disable(&lan966x->rx);
705 	lan966x_fdma_rx_free_pages(&lan966x->rx);
706 	lan966x->rx.page_order = round_up(new_mtu, PAGE_SIZE) / PAGE_SIZE - 1;
707 	err = lan966x_fdma_rx_alloc(&lan966x->rx);
708 	if (err)
709 		goto restore;
710 	lan966x_fdma_rx_start(&lan966x->rx);
711 
712 	size = sizeof(struct lan966x_rx_dcb) * FDMA_DCB_MAX;
713 	size = ALIGN(size, PAGE_SIZE);
714 	dma_free_coherent(lan966x->dev, size, rx_dcbs, rx_dma);
715 
716 	lan966x_fdma_wakeup_netdev(lan966x);
717 	napi_enable(&lan966x->napi);
718 
719 	return err;
720 restore:
721 	lan966x->rx.dma = rx_dma;
722 	lan966x->rx.dcbs = rx_dcbs;
723 	lan966x_fdma_rx_start(&lan966x->rx);
724 
725 	return err;
726 }
727 
728 int lan966x_fdma_change_mtu(struct lan966x *lan966x)
729 {
730 	int max_mtu;
731 	int err;
732 	u32 val;
733 
734 	max_mtu = lan966x_fdma_get_max_mtu(lan966x);
735 	max_mtu += IFH_LEN * sizeof(u32);
736 
737 	if (round_up(max_mtu, PAGE_SIZE) / PAGE_SIZE - 1 ==
738 	    lan966x->rx.page_order)
739 		return 0;
740 
741 	/* Disable the CPU port */
742 	lan_rmw(QSYS_SW_PORT_MODE_PORT_ENA_SET(0),
743 		QSYS_SW_PORT_MODE_PORT_ENA,
744 		lan966x, QSYS_SW_PORT_MODE(CPU_PORT));
745 
746 	/* Flush the CPU queues */
747 	readx_poll_timeout(lan966x_qsys_sw_status, lan966x,
748 			   val, !(QSYS_SW_STATUS_EQ_AVAIL_GET(val)),
749 			   READL_SLEEP_US, READL_TIMEOUT_US);
750 
751 	/* Add a sleep in case there are frames between the queues and the CPU
752 	 * port
753 	 */
754 	usleep_range(1000, 2000);
755 
756 	err = lan966x_fdma_reload(lan966x, max_mtu);
757 
758 	/* Enable back the CPU port */
759 	lan_rmw(QSYS_SW_PORT_MODE_PORT_ENA_SET(1),
760 		QSYS_SW_PORT_MODE_PORT_ENA,
761 		lan966x,  QSYS_SW_PORT_MODE(CPU_PORT));
762 
763 	return err;
764 }
765 
766 void lan966x_fdma_netdev_init(struct lan966x *lan966x, struct net_device *dev)
767 {
768 	if (lan966x->fdma_ndev)
769 		return;
770 
771 	lan966x->fdma_ndev = dev;
772 	netif_napi_add(dev, &lan966x->napi, lan966x_fdma_napi_poll);
773 	napi_enable(&lan966x->napi);
774 }
775 
776 void lan966x_fdma_netdev_deinit(struct lan966x *lan966x, struct net_device *dev)
777 {
778 	if (lan966x->fdma_ndev == dev) {
779 		netif_napi_del(&lan966x->napi);
780 		lan966x->fdma_ndev = NULL;
781 	}
782 }
783 
784 int lan966x_fdma_init(struct lan966x *lan966x)
785 {
786 	int err;
787 
788 	if (!lan966x->fdma)
789 		return 0;
790 
791 	lan966x->rx.lan966x = lan966x;
792 	lan966x->rx.channel_id = FDMA_XTR_CHANNEL;
793 	lan966x->tx.lan966x = lan966x;
794 	lan966x->tx.channel_id = FDMA_INJ_CHANNEL;
795 	lan966x->tx.last_in_use = -1;
796 
797 	err = lan966x_fdma_rx_alloc(&lan966x->rx);
798 	if (err)
799 		return err;
800 
801 	err = lan966x_fdma_tx_alloc(&lan966x->tx);
802 	if (err) {
803 		lan966x_fdma_rx_free(&lan966x->rx);
804 		return err;
805 	}
806 
807 	lan966x_fdma_rx_start(&lan966x->rx);
808 
809 	return 0;
810 }
811 
812 void lan966x_fdma_deinit(struct lan966x *lan966x)
813 {
814 	if (!lan966x->fdma)
815 		return;
816 
817 	lan966x_fdma_rx_disable(&lan966x->rx);
818 	lan966x_fdma_tx_disable(&lan966x->tx);
819 
820 	napi_synchronize(&lan966x->napi);
821 	napi_disable(&lan966x->napi);
822 
823 	lan966x_fdma_rx_free_pages(&lan966x->rx);
824 	lan966x_fdma_rx_free(&lan966x->rx);
825 	lan966x_fdma_tx_free(&lan966x->tx);
826 }
827