xref: /linux/drivers/net/ethernet/microchip/sparx5/sparx5_fdma.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
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_XTR_BUFFER_SIZE		2048
25 #define FDMA_WEIGHT			4
26 
27 static int sparx5_fdma_tx_dataptr_cb(struct fdma *fdma, int dcb, int db,
28 				     u64 *dataptr)
29 {
30 	*dataptr = fdma->dma + (sizeof(struct fdma_dcb) * fdma->n_dcbs) +
31 		   ((dcb * fdma->n_dbs + db) * fdma->db_size);
32 
33 	return 0;
34 }
35 
36 static int sparx5_fdma_rx_dataptr_cb(struct fdma *fdma, int dcb, int db,
37 				     u64 *dataptr)
38 {
39 	struct sparx5 *sparx5 = fdma->priv;
40 	struct sparx5_rx *rx = &sparx5->rx;
41 	struct sk_buff *skb;
42 
43 	skb = __netdev_alloc_skb(rx->ndev, fdma->db_size, GFP_ATOMIC);
44 	if (unlikely(!skb))
45 		return -ENOMEM;
46 
47 	*dataptr = virt_to_phys(skb->data);
48 
49 	rx->skb[dcb][db] = skb;
50 
51 	return 0;
52 }
53 
54 static void sparx5_fdma_rx_activate(struct sparx5 *sparx5, struct sparx5_rx *rx)
55 {
56 	struct fdma *fdma = &rx->fdma;
57 
58 	/* Write the buffer address in the LLP and LLP1 regs */
59 	spx5_wr(((u64)fdma->dma) & GENMASK(31, 0), sparx5,
60 		FDMA_DCB_LLP(fdma->channel_id));
61 	spx5_wr(((u64)fdma->dma) >> 32, sparx5,
62 		FDMA_DCB_LLP1(fdma->channel_id));
63 
64 	/* Set the number of RX DBs to be used, and DB end-of-frame interrupt */
65 	spx5_wr(FDMA_CH_CFG_CH_DCB_DB_CNT_SET(fdma->n_dbs) |
66 		FDMA_CH_CFG_CH_INTR_DB_EOF_ONLY_SET(1) |
67 		FDMA_CH_CFG_CH_INJ_PORT_SET(XTR_QUEUE),
68 		sparx5, FDMA_CH_CFG(fdma->channel_id));
69 
70 	/* Set the RX Watermark to max */
71 	spx5_rmw(FDMA_XTR_CFG_XTR_FIFO_WM_SET(31), FDMA_XTR_CFG_XTR_FIFO_WM,
72 		 sparx5,
73 		 FDMA_XTR_CFG);
74 
75 	/* Start RX fdma */
76 	spx5_rmw(FDMA_PORT_CTRL_XTR_STOP_SET(0), FDMA_PORT_CTRL_XTR_STOP,
77 		 sparx5, FDMA_PORT_CTRL(0));
78 
79 	/* Enable RX channel DB interrupt */
80 	spx5_rmw(BIT(fdma->channel_id),
81 		 BIT(fdma->channel_id) & FDMA_INTR_DB_ENA_INTR_DB_ENA,
82 		 sparx5, FDMA_INTR_DB_ENA);
83 
84 	/* Activate the RX channel */
85 	spx5_wr(BIT(fdma->channel_id), sparx5, FDMA_CH_ACTIVATE);
86 }
87 
88 static void sparx5_fdma_rx_deactivate(struct sparx5 *sparx5, struct sparx5_rx *rx)
89 {
90 	struct fdma *fdma = &rx->fdma;
91 
92 	/* Deactivate the RX channel */
93 	spx5_rmw(0, BIT(fdma->channel_id) & FDMA_CH_ACTIVATE_CH_ACTIVATE,
94 		 sparx5, FDMA_CH_ACTIVATE);
95 
96 	/* Disable RX channel DB interrupt */
97 	spx5_rmw(0, BIT(fdma->channel_id) & FDMA_INTR_DB_ENA_INTR_DB_ENA,
98 		 sparx5, FDMA_INTR_DB_ENA);
99 
100 	/* Stop RX fdma */
101 	spx5_rmw(FDMA_PORT_CTRL_XTR_STOP_SET(1), FDMA_PORT_CTRL_XTR_STOP,
102 		 sparx5, FDMA_PORT_CTRL(0));
103 }
104 
105 static void sparx5_fdma_tx_activate(struct sparx5 *sparx5, struct sparx5_tx *tx)
106 {
107 	struct fdma *fdma = &tx->fdma;
108 
109 	/* Write the buffer address in the LLP and LLP1 regs */
110 	spx5_wr(((u64)fdma->dma) & GENMASK(31, 0), sparx5,
111 		FDMA_DCB_LLP(fdma->channel_id));
112 	spx5_wr(((u64)fdma->dma) >> 32, sparx5,
113 		FDMA_DCB_LLP1(fdma->channel_id));
114 
115 	/* Set the number of TX DBs to be used, and DB end-of-frame interrupt */
116 	spx5_wr(FDMA_CH_CFG_CH_DCB_DB_CNT_SET(fdma->n_dbs) |
117 		FDMA_CH_CFG_CH_INTR_DB_EOF_ONLY_SET(1) |
118 		FDMA_CH_CFG_CH_INJ_PORT_SET(INJ_QUEUE),
119 		sparx5, FDMA_CH_CFG(fdma->channel_id));
120 
121 	/* Start TX fdma */
122 	spx5_rmw(FDMA_PORT_CTRL_INJ_STOP_SET(0), FDMA_PORT_CTRL_INJ_STOP,
123 		 sparx5, FDMA_PORT_CTRL(0));
124 
125 	/* Activate the channel */
126 	spx5_wr(BIT(fdma->channel_id), sparx5, FDMA_CH_ACTIVATE);
127 }
128 
129 static void sparx5_fdma_tx_deactivate(struct sparx5 *sparx5, struct sparx5_tx *tx)
130 {
131 	/* Disable the channel */
132 	spx5_rmw(0, BIT(tx->fdma.channel_id) & FDMA_CH_ACTIVATE_CH_ACTIVATE,
133 		 sparx5, FDMA_CH_ACTIVATE);
134 }
135 
136 static void sparx5_fdma_reload(struct sparx5 *sparx5, struct fdma *fdma)
137 {
138 	/* Reload the RX channel */
139 	spx5_wr(BIT(fdma->channel_id), sparx5, FDMA_CH_RELOAD);
140 }
141 
142 static bool sparx5_fdma_rx_get_frame(struct sparx5 *sparx5, struct sparx5_rx *rx)
143 {
144 	struct fdma *fdma = &rx->fdma;
145 	struct sparx5_port *port;
146 	struct fdma_db *db_hw;
147 	struct frame_info fi;
148 	struct sk_buff *skb;
149 
150 	/* Check if the DCB is done */
151 	db_hw = fdma_db_next_get(fdma);
152 	if (unlikely(!fdma_db_is_done(db_hw)))
153 		return false;
154 	skb = rx->skb[fdma->dcb_index][fdma->db_index];
155 	skb_put(skb, fdma_db_len_get(db_hw));
156 	/* Now do the normal processing of the skb */
157 	sparx5_ifh_parse((u32 *)skb->data, &fi);
158 	/* Map to port netdev */
159 	port = fi.src_port < SPX5_PORTS ?  sparx5->ports[fi.src_port] : NULL;
160 	if (!port || !port->ndev) {
161 		dev_err(sparx5->dev, "Data on inactive port %d\n", fi.src_port);
162 		sparx5_xtr_flush(sparx5, XTR_QUEUE);
163 		return false;
164 	}
165 	skb->dev = port->ndev;
166 	skb_pull(skb, IFH_LEN * sizeof(u32));
167 	if (likely(!(skb->dev->features & NETIF_F_RXFCS)))
168 		skb_trim(skb, skb->len - ETH_FCS_LEN);
169 
170 	sparx5_ptp_rxtstamp(sparx5, skb, fi.timestamp);
171 	skb->protocol = eth_type_trans(skb, skb->dev);
172 	/* Everything we see on an interface that is in the HW bridge
173 	 * has already been forwarded
174 	 */
175 	if (test_bit(port->portno, sparx5->bridge_mask))
176 		skb->offload_fwd_mark = 1;
177 	skb->dev->stats.rx_bytes += skb->len;
178 	skb->dev->stats.rx_packets++;
179 	rx->packets++;
180 	netif_receive_skb(skb);
181 	return true;
182 }
183 
184 static int sparx5_fdma_napi_callback(struct napi_struct *napi, int weight)
185 {
186 	struct sparx5_rx *rx = container_of(napi, struct sparx5_rx, napi);
187 	struct sparx5 *sparx5 = container_of(rx, struct sparx5, rx);
188 	struct fdma *fdma = &rx->fdma;
189 	int counter = 0;
190 
191 	while (counter < weight && sparx5_fdma_rx_get_frame(sparx5, rx)) {
192 		fdma_db_advance(fdma);
193 		counter++;
194 		/* Check if the DCB can be reused */
195 		if (fdma_dcb_is_reusable(fdma))
196 			continue;
197 		fdma_dcb_add(fdma, fdma->dcb_index,
198 			     FDMA_DCB_INFO_DATAL(fdma->db_size),
199 			     FDMA_DCB_STATUS_INTR);
200 		fdma_db_reset(fdma);
201 		fdma_dcb_advance(fdma);
202 	}
203 	if (counter < weight) {
204 		napi_complete_done(&rx->napi, counter);
205 		spx5_rmw(BIT(fdma->channel_id),
206 			 BIT(fdma->channel_id) & FDMA_INTR_DB_ENA_INTR_DB_ENA,
207 			 sparx5, FDMA_INTR_DB_ENA);
208 	}
209 	if (counter)
210 		sparx5_fdma_reload(sparx5, fdma);
211 	return counter;
212 }
213 
214 int sparx5_fdma_xmit(struct sparx5 *sparx5, u32 *ifh, struct sk_buff *skb)
215 {
216 	struct sparx5_tx *tx = &sparx5->tx;
217 	struct fdma *fdma = &tx->fdma;
218 	static bool first_time = true;
219 	void *virt_addr;
220 
221 	fdma_dcb_advance(fdma);
222 	if (!fdma_db_is_done(fdma_db_get(fdma, fdma->dcb_index, 0)))
223 		return -EINVAL;
224 
225 	/* Get the virtual address of the dataptr for the next DB */
226 	virt_addr = ((u8 *)fdma->dcbs +
227 		     (sizeof(struct fdma_dcb) * fdma->n_dcbs) +
228 		     ((fdma->dcb_index * fdma->n_dbs) * fdma->db_size));
229 
230 	memcpy(virt_addr, ifh, IFH_LEN * 4);
231 	memcpy(virt_addr + IFH_LEN * 4, skb->data, skb->len);
232 
233 	fdma_dcb_add(fdma, fdma->dcb_index, 0,
234 		     FDMA_DCB_STATUS_SOF |
235 		     FDMA_DCB_STATUS_EOF |
236 		     FDMA_DCB_STATUS_BLOCKO(0) |
237 		     FDMA_DCB_STATUS_BLOCKL(skb->len + IFH_LEN * 4 + 4));
238 
239 	if (first_time) {
240 		sparx5_fdma_tx_activate(sparx5, tx);
241 		first_time = false;
242 	} else {
243 		sparx5_fdma_reload(sparx5, fdma);
244 	}
245 	return NETDEV_TX_OK;
246 }
247 
248 static int sparx5_fdma_rx_alloc(struct sparx5 *sparx5)
249 {
250 	struct sparx5_rx *rx = &sparx5->rx;
251 	struct fdma *fdma = &rx->fdma;
252 	int err;
253 
254 	err = fdma_alloc_phys(fdma);
255 	if (err)
256 		return err;
257 
258 	fdma_dcbs_init(fdma, FDMA_DCB_INFO_DATAL(fdma->db_size),
259 		       FDMA_DCB_STATUS_INTR);
260 
261 	netif_napi_add_weight(rx->ndev, &rx->napi, sparx5_fdma_napi_callback,
262 			      FDMA_WEIGHT);
263 	napi_enable(&rx->napi);
264 	sparx5_fdma_rx_activate(sparx5, rx);
265 	return 0;
266 }
267 
268 static int sparx5_fdma_tx_alloc(struct sparx5 *sparx5)
269 {
270 	struct sparx5_tx *tx = &sparx5->tx;
271 	struct fdma *fdma = &tx->fdma;
272 	int err;
273 
274 	err = fdma_alloc_phys(fdma);
275 	if (err)
276 		return err;
277 
278 	fdma_dcbs_init(fdma, FDMA_DCB_INFO_DATAL(fdma->db_size),
279 		       FDMA_DCB_STATUS_DONE);
280 
281 	return 0;
282 }
283 
284 static void sparx5_fdma_rx_init(struct sparx5 *sparx5,
285 				struct sparx5_rx *rx, int channel)
286 {
287 	struct fdma *fdma = &rx->fdma;
288 	int idx;
289 
290 	fdma->channel_id = channel;
291 	fdma->n_dcbs = FDMA_DCB_MAX;
292 	fdma->n_dbs = FDMA_RX_DCB_MAX_DBS;
293 	fdma->priv = sparx5;
294 	fdma->db_size = ALIGN(FDMA_XTR_BUFFER_SIZE, PAGE_SIZE);
295 	fdma->size = fdma_get_size(&sparx5->rx.fdma);
296 	fdma->ops.dataptr_cb = &sparx5_fdma_rx_dataptr_cb;
297 	fdma->ops.nextptr_cb = &fdma_nextptr_cb;
298 	/* Fetch a netdev for SKB and NAPI use, any will do */
299 	for (idx = 0; idx < SPX5_PORTS; ++idx) {
300 		struct sparx5_port *port = sparx5->ports[idx];
301 
302 		if (port && port->ndev) {
303 			rx->ndev = port->ndev;
304 			break;
305 		}
306 	}
307 }
308 
309 static void sparx5_fdma_tx_init(struct sparx5 *sparx5,
310 				struct sparx5_tx *tx, int channel)
311 {
312 	struct fdma *fdma = &tx->fdma;
313 
314 	fdma->channel_id = channel;
315 	fdma->n_dcbs = FDMA_DCB_MAX;
316 	fdma->n_dbs = FDMA_TX_DCB_MAX_DBS;
317 	fdma->priv = sparx5;
318 	fdma->db_size = ALIGN(FDMA_XTR_BUFFER_SIZE, PAGE_SIZE);
319 	fdma->size = fdma_get_size_contiguous(&sparx5->tx.fdma);
320 	fdma->ops.dataptr_cb = &sparx5_fdma_tx_dataptr_cb;
321 	fdma->ops.nextptr_cb = &fdma_nextptr_cb;
322 }
323 
324 irqreturn_t sparx5_fdma_handler(int irq, void *args)
325 {
326 	struct sparx5 *sparx5 = args;
327 	u32 db = 0, err = 0;
328 
329 	db = spx5_rd(sparx5, FDMA_INTR_DB);
330 	err = spx5_rd(sparx5, FDMA_INTR_ERR);
331 	/* Clear interrupt */
332 	if (db) {
333 		spx5_wr(0, sparx5, FDMA_INTR_DB_ENA);
334 		spx5_wr(db, sparx5, FDMA_INTR_DB);
335 		napi_schedule(&sparx5->rx.napi);
336 	}
337 	if (err) {
338 		u32 err_type = spx5_rd(sparx5, FDMA_ERRORS);
339 
340 		dev_err_ratelimited(sparx5->dev,
341 				    "ERR: int: %#x, type: %#x\n",
342 				    err, err_type);
343 		spx5_wr(err, sparx5, FDMA_INTR_ERR);
344 		spx5_wr(err_type, sparx5, FDMA_ERRORS);
345 	}
346 	return IRQ_HANDLED;
347 }
348 
349 static void sparx5_fdma_injection_mode(struct sparx5 *sparx5)
350 {
351 	const int byte_swap = 1;
352 	int portno;
353 	int urgency;
354 
355 	/* Change mode to fdma extraction and injection */
356 	spx5_wr(QS_XTR_GRP_CFG_MODE_SET(2) |
357 		QS_XTR_GRP_CFG_STATUS_WORD_POS_SET(1) |
358 		QS_XTR_GRP_CFG_BYTE_SWAP_SET(byte_swap),
359 		sparx5, QS_XTR_GRP_CFG(XTR_QUEUE));
360 	spx5_wr(QS_INJ_GRP_CFG_MODE_SET(2) |
361 		QS_INJ_GRP_CFG_BYTE_SWAP_SET(byte_swap),
362 		sparx5, QS_INJ_GRP_CFG(INJ_QUEUE));
363 
364 	/* CPU ports capture setup */
365 	for (portno = SPX5_PORT_CPU_0; portno <= SPX5_PORT_CPU_1; portno++) {
366 		/* ASM CPU port: No preamble, IFH, enable padding */
367 		spx5_wr(ASM_PORT_CFG_PAD_ENA_SET(1) |
368 			ASM_PORT_CFG_NO_PREAMBLE_ENA_SET(1) |
369 			ASM_PORT_CFG_INJ_FORMAT_CFG_SET(1), /* 1 = IFH */
370 			sparx5, ASM_PORT_CFG(portno));
371 
372 		/* Reset WM cnt to unclog queued frames */
373 		spx5_rmw(DSM_DEV_TX_STOP_WM_CFG_DEV_TX_CNT_CLR_SET(1),
374 			 DSM_DEV_TX_STOP_WM_CFG_DEV_TX_CNT_CLR,
375 			 sparx5,
376 			 DSM_DEV_TX_STOP_WM_CFG(portno));
377 
378 		/* Set Disassembler Stop Watermark level */
379 		spx5_rmw(DSM_DEV_TX_STOP_WM_CFG_DEV_TX_STOP_WM_SET(100),
380 			 DSM_DEV_TX_STOP_WM_CFG_DEV_TX_STOP_WM,
381 			 sparx5,
382 			 DSM_DEV_TX_STOP_WM_CFG(portno));
383 
384 		/* Enable port in queue system */
385 		urgency = sparx5_port_fwd_urg(sparx5, SPEED_2500);
386 		spx5_rmw(QFWD_SWITCH_PORT_MODE_PORT_ENA_SET(1) |
387 			 QFWD_SWITCH_PORT_MODE_FWD_URGENCY_SET(urgency),
388 			 QFWD_SWITCH_PORT_MODE_PORT_ENA |
389 			 QFWD_SWITCH_PORT_MODE_FWD_URGENCY,
390 			 sparx5,
391 			 QFWD_SWITCH_PORT_MODE(portno));
392 
393 		/* Disable Disassembler buffer underrun watchdog
394 		 * to avoid truncated packets in XTR
395 		 */
396 		spx5_rmw(DSM_BUF_CFG_UNDERFLOW_WATCHDOG_DIS_SET(1),
397 			 DSM_BUF_CFG_UNDERFLOW_WATCHDOG_DIS,
398 			 sparx5,
399 			 DSM_BUF_CFG(portno));
400 
401 		/* Disabling frame aging */
402 		spx5_rmw(HSCH_PORT_MODE_AGE_DIS_SET(1),
403 			 HSCH_PORT_MODE_AGE_DIS,
404 			 sparx5,
405 			 HSCH_PORT_MODE(portno));
406 	}
407 }
408 
409 int sparx5_fdma_start(struct sparx5 *sparx5)
410 {
411 	int err;
412 
413 	/* Reset FDMA state */
414 	spx5_wr(FDMA_CTRL_NRESET_SET(0), sparx5, FDMA_CTRL);
415 	spx5_wr(FDMA_CTRL_NRESET_SET(1), sparx5, FDMA_CTRL);
416 
417 	/* Force ACP caching but disable read/write allocation */
418 	spx5_rmw(CPU_PROC_CTRL_ACP_CACHE_FORCE_ENA_SET(1) |
419 		 CPU_PROC_CTRL_ACP_AWCACHE_SET(0) |
420 		 CPU_PROC_CTRL_ACP_ARCACHE_SET(0),
421 		 CPU_PROC_CTRL_ACP_CACHE_FORCE_ENA |
422 		 CPU_PROC_CTRL_ACP_AWCACHE |
423 		 CPU_PROC_CTRL_ACP_ARCACHE,
424 		 sparx5, CPU_PROC_CTRL);
425 
426 	sparx5_fdma_injection_mode(sparx5);
427 	sparx5_fdma_rx_init(sparx5, &sparx5->rx, FDMA_XTR_CHANNEL);
428 	sparx5_fdma_tx_init(sparx5, &sparx5->tx, FDMA_INJ_CHANNEL);
429 	err = sparx5_fdma_rx_alloc(sparx5);
430 	if (err) {
431 		dev_err(sparx5->dev, "Could not allocate RX buffers: %d\n", err);
432 		return err;
433 	}
434 	err = sparx5_fdma_tx_alloc(sparx5);
435 	if (err) {
436 		dev_err(sparx5->dev, "Could not allocate TX buffers: %d\n", err);
437 		return err;
438 	}
439 	return err;
440 }
441 
442 static u32 sparx5_fdma_port_ctrl(struct sparx5 *sparx5)
443 {
444 	return spx5_rd(sparx5, FDMA_PORT_CTRL(0));
445 }
446 
447 int sparx5_fdma_stop(struct sparx5 *sparx5)
448 {
449 	u32 val;
450 
451 	napi_disable(&sparx5->rx.napi);
452 	/* Stop the fdma and channel interrupts */
453 	sparx5_fdma_rx_deactivate(sparx5, &sparx5->rx);
454 	sparx5_fdma_tx_deactivate(sparx5, &sparx5->tx);
455 	/* Wait for the RX channel to stop */
456 	read_poll_timeout(sparx5_fdma_port_ctrl, val,
457 			  FDMA_PORT_CTRL_XTR_BUF_IS_EMPTY_GET(val) == 0,
458 			  500, 10000, 0, sparx5);
459 	fdma_free_phys(&sparx5->rx.fdma);
460 	fdma_free_phys(&sparx5->tx.fdma);
461 	return 0;
462 }
463