1 // SPDX-License-Identifier: GPL-2.0+
2 /* Microchip Sparx5 Switch driver
3  *
4  * Copyright (c) 2021 Microchip Technology Inc. and its subsidiaries.
5  *
6  * The Sparx5 Chip Register Model can be browsed at this location:
7  * https://github.com/microchip-ung/sparx-5_reginfo
8  */
9 
10 #include <linux/types.h>
11 #include <linux/skbuff.h>
12 #include <linux/netdevice.h>
13 #include <linux/interrupt.h>
14 #include <linux/ip.h>
15 #include <linux/dma-mapping.h>
16 
17 #include "sparx5_main_regs.h"
18 #include "sparx5_main.h"
19 #include "sparx5_port.h"
20 
21 #define FDMA_XTR_CHANNEL		6
22 #define FDMA_INJ_CHANNEL		0
23 
24 #define FDMA_DCB_INFO_DATAL(x)		((x) & GENMASK(15, 0))
25 #define FDMA_DCB_INFO_TOKEN		BIT(17)
26 #define FDMA_DCB_INFO_INTR		BIT(18)
27 #define FDMA_DCB_INFO_SW(x)		(((x) << 24) & GENMASK(31, 24))
28 
29 #define FDMA_DCB_STATUS_BLOCKL(x)	((x) & GENMASK(15, 0))
30 #define FDMA_DCB_STATUS_SOF		BIT(16)
31 #define FDMA_DCB_STATUS_EOF		BIT(17)
32 #define FDMA_DCB_STATUS_INTR		BIT(18)
33 #define FDMA_DCB_STATUS_DONE		BIT(19)
34 #define FDMA_DCB_STATUS_BLOCKO(x)	(((x) << 20) & GENMASK(31, 20))
35 #define FDMA_DCB_INVALID_DATA		0x1
36 
37 #define FDMA_XTR_BUFFER_SIZE		2048
38 #define FDMA_WEIGHT			4
39 
40 /* Frame DMA DCB format
41  *
42  * +---------------------------+
43  * |         Next Ptr          |
44  * +---------------------------+
45  * |   Reserved  |    Info     |
46  * +---------------------------+
47  * |         Data0 Ptr         |
48  * +---------------------------+
49  * |   Reserved  |    Status0  |
50  * +---------------------------+
51  * |         Data1 Ptr         |
52  * +---------------------------+
53  * |   Reserved  |    Status1  |
54  * +---------------------------+
55  * |         Data2 Ptr         |
56  * +---------------------------+
57  * |   Reserved  |    Status2  |
58  * |-------------|-------------|
59  * |                           |
60  * |                           |
61  * |                           |
62  * |                           |
63  * |                           |
64  * |---------------------------|
65  * |         Data14 Ptr        |
66  * +-------------|-------------+
67  * |   Reserved  |    Status14 |
68  * +-------------|-------------+
69  */
70 
71 /* For each hardware DB there is an entry in this list and when the HW DB
72  * entry is used, this SW DB entry is moved to the back of the list
73  */
74 struct sparx5_db {
75 	struct list_head list;
76 	void *cpu_addr;
77 };
78 
79 static void sparx5_fdma_rx_add_dcb(struct sparx5_rx *rx,
80 				   struct sparx5_rx_dcb_hw *dcb,
81 				   u64 nextptr)
82 {
83 	int idx = 0;
84 
85 	/* Reset the status of the DB */
86 	for (idx = 0; idx < FDMA_RX_DCB_MAX_DBS; ++idx) {
87 		struct sparx5_db_hw *db = &dcb->db[idx];
88 
89 		db->status = FDMA_DCB_STATUS_INTR;
90 	}
91 	dcb->nextptr = FDMA_DCB_INVALID_DATA;
92 	dcb->info = FDMA_DCB_INFO_DATAL(FDMA_XTR_BUFFER_SIZE);
93 	rx->last_entry->nextptr = nextptr;
94 	rx->last_entry = dcb;
95 }
96 
97 static void sparx5_fdma_tx_add_dcb(struct sparx5_tx *tx,
98 				   struct sparx5_tx_dcb_hw *dcb,
99 				   u64 nextptr)
100 {
101 	int idx = 0;
102 
103 	/* Reset the status of the DB */
104 	for (idx = 0; idx < FDMA_TX_DCB_MAX_DBS; ++idx) {
105 		struct sparx5_db_hw *db = &dcb->db[idx];
106 
107 		db->status = FDMA_DCB_STATUS_DONE;
108 	}
109 	dcb->nextptr = FDMA_DCB_INVALID_DATA;
110 	dcb->info = FDMA_DCB_INFO_DATAL(FDMA_XTR_BUFFER_SIZE);
111 }
112 
113 static void sparx5_fdma_rx_activate(struct sparx5 *sparx5, struct sparx5_rx *rx)
114 {
115 	/* Write the buffer address in the LLP and LLP1 regs */
116 	spx5_wr(((u64)rx->dma) & GENMASK(31, 0), sparx5,
117 		FDMA_DCB_LLP(rx->channel_id));
118 	spx5_wr(((u64)rx->dma) >> 32, sparx5, FDMA_DCB_LLP1(rx->channel_id));
119 
120 	/* Set the number of RX DBs to be used, and DB end-of-frame interrupt */
121 	spx5_wr(FDMA_CH_CFG_CH_DCB_DB_CNT_SET(FDMA_RX_DCB_MAX_DBS) |
122 		FDMA_CH_CFG_CH_INTR_DB_EOF_ONLY_SET(1) |
123 		FDMA_CH_CFG_CH_INJ_PORT_SET(XTR_QUEUE),
124 		sparx5, FDMA_CH_CFG(rx->channel_id));
125 
126 	/* Set the RX Watermark to max */
127 	spx5_rmw(FDMA_XTR_CFG_XTR_FIFO_WM_SET(31), FDMA_XTR_CFG_XTR_FIFO_WM,
128 		 sparx5,
129 		 FDMA_XTR_CFG);
130 
131 	/* Start RX fdma */
132 	spx5_rmw(FDMA_PORT_CTRL_XTR_STOP_SET(0), FDMA_PORT_CTRL_XTR_STOP,
133 		 sparx5, FDMA_PORT_CTRL(0));
134 
135 	/* Enable RX channel DB interrupt */
136 	spx5_rmw(BIT(rx->channel_id),
137 		 BIT(rx->channel_id) & FDMA_INTR_DB_ENA_INTR_DB_ENA,
138 		 sparx5, FDMA_INTR_DB_ENA);
139 
140 	/* Activate the RX channel */
141 	spx5_wr(BIT(rx->channel_id), sparx5, FDMA_CH_ACTIVATE);
142 }
143 
144 static void sparx5_fdma_rx_deactivate(struct sparx5 *sparx5, struct sparx5_rx *rx)
145 {
146 	/* Dectivate the RX channel */
147 	spx5_rmw(0, BIT(rx->channel_id) & FDMA_CH_ACTIVATE_CH_ACTIVATE,
148 		 sparx5, FDMA_CH_ACTIVATE);
149 
150 	/* Disable RX channel DB interrupt */
151 	spx5_rmw(0, BIT(rx->channel_id) & FDMA_INTR_DB_ENA_INTR_DB_ENA,
152 		 sparx5, FDMA_INTR_DB_ENA);
153 
154 	/* Stop RX fdma */
155 	spx5_rmw(FDMA_PORT_CTRL_XTR_STOP_SET(1), FDMA_PORT_CTRL_XTR_STOP,
156 		 sparx5, FDMA_PORT_CTRL(0));
157 }
158 
159 static void sparx5_fdma_tx_activate(struct sparx5 *sparx5, struct sparx5_tx *tx)
160 {
161 	/* Write the buffer address in the LLP and LLP1 regs */
162 	spx5_wr(((u64)tx->dma) & GENMASK(31, 0), sparx5,
163 		FDMA_DCB_LLP(tx->channel_id));
164 	spx5_wr(((u64)tx->dma) >> 32, sparx5, FDMA_DCB_LLP1(tx->channel_id));
165 
166 	/* Set the number of TX DBs to be used, and DB end-of-frame interrupt */
167 	spx5_wr(FDMA_CH_CFG_CH_DCB_DB_CNT_SET(FDMA_TX_DCB_MAX_DBS) |
168 		FDMA_CH_CFG_CH_INTR_DB_EOF_ONLY_SET(1) |
169 		FDMA_CH_CFG_CH_INJ_PORT_SET(INJ_QUEUE),
170 		sparx5, FDMA_CH_CFG(tx->channel_id));
171 
172 	/* Start TX fdma */
173 	spx5_rmw(FDMA_PORT_CTRL_INJ_STOP_SET(0), FDMA_PORT_CTRL_INJ_STOP,
174 		 sparx5, FDMA_PORT_CTRL(0));
175 
176 	/* Activate the channel */
177 	spx5_wr(BIT(tx->channel_id), sparx5, FDMA_CH_ACTIVATE);
178 }
179 
180 static void sparx5_fdma_tx_deactivate(struct sparx5 *sparx5, struct sparx5_tx *tx)
181 {
182 	/* Disable the channel */
183 	spx5_rmw(0, BIT(tx->channel_id) & FDMA_CH_ACTIVATE_CH_ACTIVATE,
184 		 sparx5, FDMA_CH_ACTIVATE);
185 }
186 
187 static void sparx5_fdma_rx_reload(struct sparx5 *sparx5, struct sparx5_rx *rx)
188 {
189 	/* Reload the RX channel */
190 	spx5_wr(BIT(rx->channel_id), sparx5, FDMA_CH_RELOAD);
191 }
192 
193 static void sparx5_fdma_tx_reload(struct sparx5 *sparx5, struct sparx5_tx *tx)
194 {
195 	/* Reload the TX channel */
196 	spx5_wr(BIT(tx->channel_id), sparx5, FDMA_CH_RELOAD);
197 }
198 
199 static struct sk_buff *sparx5_fdma_rx_alloc_skb(struct sparx5_rx *rx)
200 {
201 	return __netdev_alloc_skb(rx->ndev, FDMA_XTR_BUFFER_SIZE,
202 				  GFP_ATOMIC);
203 }
204 
205 static bool sparx5_fdma_rx_get_frame(struct sparx5 *sparx5, struct sparx5_rx *rx)
206 {
207 	struct sparx5_db_hw *db_hw;
208 	unsigned int packet_size;
209 	struct sparx5_port *port;
210 	struct sk_buff *new_skb;
211 	struct frame_info fi;
212 	struct sk_buff *skb;
213 	dma_addr_t dma_addr;
214 
215 	/* Check if the DCB is done */
216 	db_hw = &rx->dcb_entries[rx->dcb_index].db[rx->db_index];
217 	if (unlikely(!(db_hw->status & FDMA_DCB_STATUS_DONE)))
218 		return false;
219 	skb = rx->skb[rx->dcb_index][rx->db_index];
220 	/* Replace the DB entry with a new SKB */
221 	new_skb = sparx5_fdma_rx_alloc_skb(rx);
222 	if (unlikely(!new_skb))
223 		return false;
224 	/* Map the new skb data and set the new skb */
225 	dma_addr = virt_to_phys(new_skb->data);
226 	rx->skb[rx->dcb_index][rx->db_index] = new_skb;
227 	db_hw->dataptr = dma_addr;
228 	packet_size = FDMA_DCB_STATUS_BLOCKL(db_hw->status);
229 	skb_put(skb, packet_size);
230 	/* Now do the normal processing of the skb */
231 	sparx5_ifh_parse((u32 *)skb->data, &fi);
232 	/* Map to port netdev */
233 	port = fi.src_port < SPX5_PORTS ?  sparx5->ports[fi.src_port] : NULL;
234 	if (!port || !port->ndev) {
235 		dev_err(sparx5->dev, "Data on inactive port %d\n", fi.src_port);
236 		sparx5_xtr_flush(sparx5, XTR_QUEUE);
237 		return false;
238 	}
239 	skb->dev = port->ndev;
240 	skb_pull(skb, IFH_LEN * sizeof(u32));
241 	if (likely(!(skb->dev->features & NETIF_F_RXFCS)))
242 		skb_trim(skb, skb->len - ETH_FCS_LEN);
243 
244 	sparx5_ptp_rxtstamp(sparx5, skb, fi.timestamp);
245 	skb->protocol = eth_type_trans(skb, skb->dev);
246 	/* Everything we see on an interface that is in the HW bridge
247 	 * has already been forwarded
248 	 */
249 	if (test_bit(port->portno, sparx5->bridge_mask))
250 		skb->offload_fwd_mark = 1;
251 	skb->dev->stats.rx_bytes += skb->len;
252 	skb->dev->stats.rx_packets++;
253 	rx->packets++;
254 	netif_receive_skb(skb);
255 	return true;
256 }
257 
258 static int sparx5_fdma_napi_callback(struct napi_struct *napi, int weight)
259 {
260 	struct sparx5_rx *rx = container_of(napi, struct sparx5_rx, napi);
261 	struct sparx5 *sparx5 = container_of(rx, struct sparx5, rx);
262 	int counter = 0;
263 
264 	while (counter < weight && sparx5_fdma_rx_get_frame(sparx5, rx)) {
265 		struct sparx5_rx_dcb_hw *old_dcb;
266 
267 		rx->db_index++;
268 		counter++;
269 		/* Check if the DCB can be reused */
270 		if (rx->db_index != FDMA_RX_DCB_MAX_DBS)
271 			continue;
272 		/* As the DCB  can be reused, just advance the dcb_index
273 		 * pointer and set the nextptr in the DCB
274 		 */
275 		rx->db_index = 0;
276 		old_dcb = &rx->dcb_entries[rx->dcb_index];
277 		rx->dcb_index++;
278 		rx->dcb_index &= FDMA_DCB_MAX - 1;
279 		sparx5_fdma_rx_add_dcb(rx, old_dcb,
280 				       rx->dma +
281 				       ((unsigned long)old_dcb -
282 					(unsigned long)rx->dcb_entries));
283 	}
284 	if (counter < weight) {
285 		napi_complete_done(&rx->napi, counter);
286 		spx5_rmw(BIT(rx->channel_id),
287 			 BIT(rx->channel_id) & FDMA_INTR_DB_ENA_INTR_DB_ENA,
288 			 sparx5, FDMA_INTR_DB_ENA);
289 	}
290 	if (counter)
291 		sparx5_fdma_rx_reload(sparx5, rx);
292 	return counter;
293 }
294 
295 static struct sparx5_tx_dcb_hw *sparx5_fdma_next_dcb(struct sparx5_tx *tx,
296 						     struct sparx5_tx_dcb_hw *dcb)
297 {
298 	struct sparx5_tx_dcb_hw *next_dcb;
299 
300 	next_dcb = dcb;
301 	next_dcb++;
302 	/* Handle wrap-around */
303 	if ((unsigned long)next_dcb >=
304 	    ((unsigned long)tx->first_entry + FDMA_DCB_MAX * sizeof(*dcb)))
305 		next_dcb = tx->first_entry;
306 	return next_dcb;
307 }
308 
309 int sparx5_fdma_xmit(struct sparx5 *sparx5, u32 *ifh, struct sk_buff *skb)
310 {
311 	struct sparx5_tx_dcb_hw *next_dcb_hw;
312 	struct sparx5_tx *tx = &sparx5->tx;
313 	static bool first_time = true;
314 	struct sparx5_db_hw *db_hw;
315 	struct sparx5_db *db;
316 
317 	next_dcb_hw = sparx5_fdma_next_dcb(tx, tx->curr_entry);
318 	db_hw = &next_dcb_hw->db[0];
319 	if (!(db_hw->status & FDMA_DCB_STATUS_DONE))
320 		return -EINVAL;
321 	db = list_first_entry(&tx->db_list, struct sparx5_db, list);
322 	list_move_tail(&db->list, &tx->db_list);
323 	next_dcb_hw->nextptr = FDMA_DCB_INVALID_DATA;
324 	tx->curr_entry->nextptr = tx->dma +
325 		((unsigned long)next_dcb_hw -
326 		 (unsigned long)tx->first_entry);
327 	tx->curr_entry = next_dcb_hw;
328 	memset(db->cpu_addr, 0, FDMA_XTR_BUFFER_SIZE);
329 	memcpy(db->cpu_addr, ifh, IFH_LEN * 4);
330 	memcpy(db->cpu_addr + IFH_LEN * 4, skb->data, skb->len);
331 	db_hw->status = FDMA_DCB_STATUS_SOF |
332 			FDMA_DCB_STATUS_EOF |
333 			FDMA_DCB_STATUS_BLOCKO(0) |
334 			FDMA_DCB_STATUS_BLOCKL(skb->len + IFH_LEN * 4 + 4);
335 	if (first_time) {
336 		sparx5_fdma_tx_activate(sparx5, tx);
337 		first_time = false;
338 	} else {
339 		sparx5_fdma_tx_reload(sparx5, tx);
340 	}
341 	return NETDEV_TX_OK;
342 }
343 
344 static int sparx5_fdma_rx_alloc(struct sparx5 *sparx5)
345 {
346 	struct sparx5_rx *rx = &sparx5->rx;
347 	struct sparx5_rx_dcb_hw *dcb;
348 	int idx, jdx;
349 	int size;
350 
351 	size = sizeof(struct sparx5_rx_dcb_hw) * FDMA_DCB_MAX;
352 	size = ALIGN(size, PAGE_SIZE);
353 	rx->dcb_entries = devm_kzalloc(sparx5->dev, size, GFP_KERNEL);
354 	if (!rx->dcb_entries)
355 		return -ENOMEM;
356 	rx->dma = virt_to_phys(rx->dcb_entries);
357 	rx->last_entry = rx->dcb_entries;
358 	rx->db_index = 0;
359 	rx->dcb_index = 0;
360 	/* Now for each dcb allocate the db */
361 	for (idx = 0; idx < FDMA_DCB_MAX; ++idx) {
362 		dcb = &rx->dcb_entries[idx];
363 		dcb->info = 0;
364 		/* For each db allocate an skb and map skb data pointer to the DB
365 		 * dataptr. In this way when the frame is received the skb->data
366 		 * will contain the frame, so no memcpy is needed
367 		 */
368 		for (jdx = 0; jdx < FDMA_RX_DCB_MAX_DBS; ++jdx) {
369 			struct sparx5_db_hw *db_hw = &dcb->db[jdx];
370 			dma_addr_t dma_addr;
371 			struct sk_buff *skb;
372 
373 			skb = sparx5_fdma_rx_alloc_skb(rx);
374 			if (!skb)
375 				return -ENOMEM;
376 
377 			dma_addr = virt_to_phys(skb->data);
378 			db_hw->dataptr = dma_addr;
379 			db_hw->status = 0;
380 			rx->skb[idx][jdx] = skb;
381 		}
382 		sparx5_fdma_rx_add_dcb(rx, dcb, rx->dma + sizeof(*dcb) * idx);
383 	}
384 	netif_napi_add_weight(rx->ndev, &rx->napi, sparx5_fdma_napi_callback,
385 			      FDMA_WEIGHT);
386 	napi_enable(&rx->napi);
387 	sparx5_fdma_rx_activate(sparx5, rx);
388 	return 0;
389 }
390 
391 static int sparx5_fdma_tx_alloc(struct sparx5 *sparx5)
392 {
393 	struct sparx5_tx *tx = &sparx5->tx;
394 	struct sparx5_tx_dcb_hw *dcb;
395 	int idx, jdx;
396 	int size;
397 
398 	size = sizeof(struct sparx5_tx_dcb_hw) * FDMA_DCB_MAX;
399 	size = ALIGN(size, PAGE_SIZE);
400 	tx->curr_entry = devm_kzalloc(sparx5->dev, size, GFP_KERNEL);
401 	if (!tx->curr_entry)
402 		return -ENOMEM;
403 	tx->dma = virt_to_phys(tx->curr_entry);
404 	tx->first_entry = tx->curr_entry;
405 	INIT_LIST_HEAD(&tx->db_list);
406 	/* Now for each dcb allocate the db */
407 	for (idx = 0; idx < FDMA_DCB_MAX; ++idx) {
408 		dcb = &tx->curr_entry[idx];
409 		dcb->info = 0;
410 		/* TX databuffers must be 16byte aligned */
411 		for (jdx = 0; jdx < FDMA_TX_DCB_MAX_DBS; ++jdx) {
412 			struct sparx5_db_hw *db_hw = &dcb->db[jdx];
413 			struct sparx5_db *db;
414 			dma_addr_t phys;
415 			void *cpu_addr;
416 
417 			cpu_addr = devm_kzalloc(sparx5->dev,
418 						FDMA_XTR_BUFFER_SIZE,
419 						GFP_KERNEL);
420 			if (!cpu_addr)
421 				return -ENOMEM;
422 			phys = virt_to_phys(cpu_addr);
423 			db_hw->dataptr = phys;
424 			db_hw->status = 0;
425 			db = devm_kzalloc(sparx5->dev, sizeof(*db), GFP_KERNEL);
426 			if (!db)
427 				return -ENOMEM;
428 			db->cpu_addr = cpu_addr;
429 			list_add_tail(&db->list, &tx->db_list);
430 		}
431 		sparx5_fdma_tx_add_dcb(tx, dcb, tx->dma + sizeof(*dcb) * idx);
432 		/* Let the curr_entry to point to the last allocated entry */
433 		if (idx == FDMA_DCB_MAX - 1)
434 			tx->curr_entry = dcb;
435 	}
436 	return 0;
437 }
438 
439 static void sparx5_fdma_rx_init(struct sparx5 *sparx5,
440 				struct sparx5_rx *rx, int channel)
441 {
442 	int idx;
443 
444 	rx->channel_id = channel;
445 	/* Fetch a netdev for SKB and NAPI use, any will do */
446 	for (idx = 0; idx < SPX5_PORTS; ++idx) {
447 		struct sparx5_port *port = sparx5->ports[idx];
448 
449 		if (port && port->ndev) {
450 			rx->ndev = port->ndev;
451 			break;
452 		}
453 	}
454 }
455 
456 static void sparx5_fdma_tx_init(struct sparx5 *sparx5,
457 				struct sparx5_tx *tx, int channel)
458 {
459 	tx->channel_id = channel;
460 }
461 
462 irqreturn_t sparx5_fdma_handler(int irq, void *args)
463 {
464 	struct sparx5 *sparx5 = args;
465 	u32 db = 0, err = 0;
466 
467 	db = spx5_rd(sparx5, FDMA_INTR_DB);
468 	err = spx5_rd(sparx5, FDMA_INTR_ERR);
469 	/* Clear interrupt */
470 	if (db) {
471 		spx5_wr(0, sparx5, FDMA_INTR_DB_ENA);
472 		spx5_wr(db, sparx5, FDMA_INTR_DB);
473 		napi_schedule(&sparx5->rx.napi);
474 	}
475 	if (err) {
476 		u32 err_type = spx5_rd(sparx5, FDMA_ERRORS);
477 
478 		dev_err_ratelimited(sparx5->dev,
479 				    "ERR: int: %#x, type: %#x\n",
480 				    err, err_type);
481 		spx5_wr(err, sparx5, FDMA_INTR_ERR);
482 		spx5_wr(err_type, sparx5, FDMA_ERRORS);
483 	}
484 	return IRQ_HANDLED;
485 }
486 
487 static void sparx5_fdma_injection_mode(struct sparx5 *sparx5)
488 {
489 	const int byte_swap = 1;
490 	int portno;
491 	int urgency;
492 
493 	/* Change mode to fdma extraction and injection */
494 	spx5_wr(QS_XTR_GRP_CFG_MODE_SET(2) |
495 		QS_XTR_GRP_CFG_STATUS_WORD_POS_SET(1) |
496 		QS_XTR_GRP_CFG_BYTE_SWAP_SET(byte_swap),
497 		sparx5, QS_XTR_GRP_CFG(XTR_QUEUE));
498 	spx5_wr(QS_INJ_GRP_CFG_MODE_SET(2) |
499 		QS_INJ_GRP_CFG_BYTE_SWAP_SET(byte_swap),
500 		sparx5, QS_INJ_GRP_CFG(INJ_QUEUE));
501 
502 	/* CPU ports capture setup */
503 	for (portno = SPX5_PORT_CPU_0; portno <= SPX5_PORT_CPU_1; portno++) {
504 		/* ASM CPU port: No preamble, IFH, enable padding */
505 		spx5_wr(ASM_PORT_CFG_PAD_ENA_SET(1) |
506 			ASM_PORT_CFG_NO_PREAMBLE_ENA_SET(1) |
507 			ASM_PORT_CFG_INJ_FORMAT_CFG_SET(1), /* 1 = IFH */
508 			sparx5, ASM_PORT_CFG(portno));
509 
510 		/* Reset WM cnt to unclog queued frames */
511 		spx5_rmw(DSM_DEV_TX_STOP_WM_CFG_DEV_TX_CNT_CLR_SET(1),
512 			 DSM_DEV_TX_STOP_WM_CFG_DEV_TX_CNT_CLR,
513 			 sparx5,
514 			 DSM_DEV_TX_STOP_WM_CFG(portno));
515 
516 		/* Set Disassembler Stop Watermark level */
517 		spx5_rmw(DSM_DEV_TX_STOP_WM_CFG_DEV_TX_STOP_WM_SET(100),
518 			 DSM_DEV_TX_STOP_WM_CFG_DEV_TX_STOP_WM,
519 			 sparx5,
520 			 DSM_DEV_TX_STOP_WM_CFG(portno));
521 
522 		/* Enable port in queue system */
523 		urgency = sparx5_port_fwd_urg(sparx5, SPEED_2500);
524 		spx5_rmw(QFWD_SWITCH_PORT_MODE_PORT_ENA_SET(1) |
525 			 QFWD_SWITCH_PORT_MODE_FWD_URGENCY_SET(urgency),
526 			 QFWD_SWITCH_PORT_MODE_PORT_ENA |
527 			 QFWD_SWITCH_PORT_MODE_FWD_URGENCY,
528 			 sparx5,
529 			 QFWD_SWITCH_PORT_MODE(portno));
530 
531 		/* Disable Disassembler buffer underrun watchdog
532 		 * to avoid truncated packets in XTR
533 		 */
534 		spx5_rmw(DSM_BUF_CFG_UNDERFLOW_WATCHDOG_DIS_SET(1),
535 			 DSM_BUF_CFG_UNDERFLOW_WATCHDOG_DIS,
536 			 sparx5,
537 			 DSM_BUF_CFG(portno));
538 
539 		/* Disabling frame aging */
540 		spx5_rmw(HSCH_PORT_MODE_AGE_DIS_SET(1),
541 			 HSCH_PORT_MODE_AGE_DIS,
542 			 sparx5,
543 			 HSCH_PORT_MODE(portno));
544 	}
545 }
546 
547 int sparx5_fdma_start(struct sparx5 *sparx5)
548 {
549 	int err;
550 
551 	/* Reset FDMA state */
552 	spx5_wr(FDMA_CTRL_NRESET_SET(0), sparx5, FDMA_CTRL);
553 	spx5_wr(FDMA_CTRL_NRESET_SET(1), sparx5, FDMA_CTRL);
554 
555 	/* Force ACP caching but disable read/write allocation */
556 	spx5_rmw(CPU_PROC_CTRL_ACP_CACHE_FORCE_ENA_SET(1) |
557 		 CPU_PROC_CTRL_ACP_AWCACHE_SET(0) |
558 		 CPU_PROC_CTRL_ACP_ARCACHE_SET(0),
559 		 CPU_PROC_CTRL_ACP_CACHE_FORCE_ENA |
560 		 CPU_PROC_CTRL_ACP_AWCACHE |
561 		 CPU_PROC_CTRL_ACP_ARCACHE,
562 		 sparx5, CPU_PROC_CTRL);
563 
564 	sparx5_fdma_injection_mode(sparx5);
565 	sparx5_fdma_rx_init(sparx5, &sparx5->rx, FDMA_XTR_CHANNEL);
566 	sparx5_fdma_tx_init(sparx5, &sparx5->tx, FDMA_INJ_CHANNEL);
567 	err = sparx5_fdma_rx_alloc(sparx5);
568 	if (err) {
569 		dev_err(sparx5->dev, "Could not allocate RX buffers: %d\n", err);
570 		return err;
571 	}
572 	err = sparx5_fdma_tx_alloc(sparx5);
573 	if (err) {
574 		dev_err(sparx5->dev, "Could not allocate TX buffers: %d\n", err);
575 		return err;
576 	}
577 	return err;
578 }
579 
580 static u32 sparx5_fdma_port_ctrl(struct sparx5 *sparx5)
581 {
582 	return spx5_rd(sparx5, FDMA_PORT_CTRL(0));
583 }
584 
585 int sparx5_fdma_stop(struct sparx5 *sparx5)
586 {
587 	u32 val;
588 
589 	napi_disable(&sparx5->rx.napi);
590 	/* Stop the fdma and channel interrupts */
591 	sparx5_fdma_rx_deactivate(sparx5, &sparx5->rx);
592 	sparx5_fdma_tx_deactivate(sparx5, &sparx5->tx);
593 	/* Wait for the RX channel to stop */
594 	read_poll_timeout(sparx5_fdma_port_ctrl, val,
595 			  FDMA_PORT_CTRL_XTR_BUF_IS_EMPTY_GET(val) == 0,
596 			  500, 10000, 0, sparx5);
597 	return 0;
598 }
599