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 
7 #include "sparx5_main_regs.h"
8 #include "sparx5_main.h"
9 
10 #define XTR_EOF_0     ntohl((__force __be32)0x80000000u)
11 #define XTR_EOF_1     ntohl((__force __be32)0x80000001u)
12 #define XTR_EOF_2     ntohl((__force __be32)0x80000002u)
13 #define XTR_EOF_3     ntohl((__force __be32)0x80000003u)
14 #define XTR_PRUNED    ntohl((__force __be32)0x80000004u)
15 #define XTR_ABORT     ntohl((__force __be32)0x80000005u)
16 #define XTR_ESCAPE    ntohl((__force __be32)0x80000006u)
17 #define XTR_NOT_READY ntohl((__force __be32)0x80000007u)
18 
19 #define XTR_VALID_BYTES(x)      (4 - ((x) & 3))
20 
21 #define INJ_TIMEOUT_NS 50000
22 
23 void sparx5_xtr_flush(struct sparx5 *sparx5, u8 grp)
24 {
25 	/* Start flush */
26 	spx5_wr(QS_XTR_FLUSH_FLUSH_SET(BIT(grp)), sparx5, QS_XTR_FLUSH);
27 
28 	/* Allow to drain */
29 	mdelay(1);
30 
31 	/* All Queues normal */
32 	spx5_wr(0, sparx5, QS_XTR_FLUSH);
33 }
34 
35 void sparx5_ifh_parse(u32 *ifh, struct frame_info *info)
36 {
37 	u8 *xtr_hdr = (u8 *)ifh;
38 
39 	/* FWD is bit 45-72 (28 bits), but we only read the 27 LSB for now */
40 	u32 fwd =
41 		((u32)xtr_hdr[27] << 24) |
42 		((u32)xtr_hdr[28] << 16) |
43 		((u32)xtr_hdr[29] <<  8) |
44 		((u32)xtr_hdr[30] <<  0);
45 	fwd = (fwd >> 5);
46 	info->src_port = FIELD_GET(GENMASK(7, 1), fwd);
47 
48 	/*
49 	 * Bit 270-271 are occasionally unexpectedly set by the hardware,
50 	 * clear bits before extracting timestamp
51 	 */
52 	info->timestamp =
53 		((u64)(xtr_hdr[2] & GENMASK(5, 0)) << 24) |
54 		((u64)xtr_hdr[3] << 16) |
55 		((u64)xtr_hdr[4] <<  8) |
56 		((u64)xtr_hdr[5] <<  0);
57 }
58 
59 static void sparx5_xtr_grp(struct sparx5 *sparx5, u8 grp, bool byte_swap)
60 {
61 	bool eof_flag = false, pruned_flag = false, abort_flag = false;
62 	struct net_device *netdev;
63 	struct sparx5_port *port;
64 	struct frame_info fi;
65 	int i, byte_cnt = 0;
66 	struct sk_buff *skb;
67 	u32 ifh[IFH_LEN];
68 	u32 *rxbuf;
69 
70 	/* Get IFH */
71 	for (i = 0; i < IFH_LEN; i++)
72 		ifh[i] = spx5_rd(sparx5, QS_XTR_RD(grp));
73 
74 	/* Decode IFH (whats needed) */
75 	sparx5_ifh_parse(ifh, &fi);
76 
77 	/* Map to port netdev */
78 	port = fi.src_port < SPX5_PORTS ?
79 		sparx5->ports[fi.src_port] : NULL;
80 	if (!port || !port->ndev) {
81 		dev_err(sparx5->dev, "Data on inactive port %d\n", fi.src_port);
82 		sparx5_xtr_flush(sparx5, grp);
83 		return;
84 	}
85 
86 	/* Have netdev, get skb */
87 	netdev = port->ndev;
88 	skb = netdev_alloc_skb(netdev, netdev->mtu + ETH_HLEN);
89 	if (!skb) {
90 		sparx5_xtr_flush(sparx5, grp);
91 		dev_err(sparx5->dev, "No skb allocated\n");
92 		netdev->stats.rx_dropped++;
93 		return;
94 	}
95 	rxbuf = (u32 *)skb->data;
96 
97 	/* Now, pull frame data */
98 	while (!eof_flag) {
99 		u32 val = spx5_rd(sparx5, QS_XTR_RD(grp));
100 		u32 cmp = val;
101 
102 		if (byte_swap)
103 			cmp = ntohl((__force __be32)val);
104 
105 		switch (cmp) {
106 		case XTR_NOT_READY:
107 			break;
108 		case XTR_ABORT:
109 			/* No accompanying data */
110 			abort_flag = true;
111 			eof_flag = true;
112 			break;
113 		case XTR_EOF_0:
114 		case XTR_EOF_1:
115 		case XTR_EOF_2:
116 		case XTR_EOF_3:
117 			/* This assumes STATUS_WORD_POS == 1, Status
118 			 * just after last data
119 			 */
120 			if (!byte_swap)
121 				val = ntohl((__force __be32)val);
122 			byte_cnt -= (4 - XTR_VALID_BYTES(val));
123 			eof_flag = true;
124 			break;
125 		case XTR_PRUNED:
126 			/* But get the last 4 bytes as well */
127 			eof_flag = true;
128 			pruned_flag = true;
129 			fallthrough;
130 		case XTR_ESCAPE:
131 			*rxbuf = spx5_rd(sparx5, QS_XTR_RD(grp));
132 			byte_cnt += 4;
133 			rxbuf++;
134 			break;
135 		default:
136 			*rxbuf = val;
137 			byte_cnt += 4;
138 			rxbuf++;
139 		}
140 	}
141 
142 	if (abort_flag || pruned_flag || !eof_flag) {
143 		netdev_err(netdev, "Discarded frame: abort:%d pruned:%d eof:%d\n",
144 			   abort_flag, pruned_flag, eof_flag);
145 		kfree_skb(skb);
146 		netdev->stats.rx_dropped++;
147 		return;
148 	}
149 
150 	/* Everything we see on an interface that is in the HW bridge
151 	 * has already been forwarded
152 	 */
153 	if (test_bit(port->portno, sparx5->bridge_mask))
154 		skb->offload_fwd_mark = 1;
155 
156 	/* Finish up skb */
157 	skb_put(skb, byte_cnt - ETH_FCS_LEN);
158 	eth_skb_pad(skb);
159 	sparx5_ptp_rxtstamp(sparx5, skb, fi.timestamp);
160 	skb->protocol = eth_type_trans(skb, netdev);
161 	netdev->stats.rx_bytes += skb->len;
162 	netdev->stats.rx_packets++;
163 	netif_rx(skb);
164 }
165 
166 static int sparx5_inject(struct sparx5 *sparx5,
167 			 u32 *ifh,
168 			 struct sk_buff *skb,
169 			 struct net_device *ndev)
170 {
171 	int grp = INJ_QUEUE;
172 	u32 val, w, count;
173 	u8 *buf;
174 
175 	val = spx5_rd(sparx5, QS_INJ_STATUS);
176 	if (!(QS_INJ_STATUS_FIFO_RDY_GET(val) & BIT(grp))) {
177 		pr_err_ratelimited("Injection: Queue not ready: 0x%lx\n",
178 				   QS_INJ_STATUS_FIFO_RDY_GET(val));
179 		return -EBUSY;
180 	}
181 
182 	/* Indicate SOF */
183 	spx5_wr(QS_INJ_CTRL_SOF_SET(1) |
184 		QS_INJ_CTRL_GAP_SIZE_SET(1),
185 		sparx5, QS_INJ_CTRL(grp));
186 
187 	/* Write the IFH to the chip. */
188 	for (w = 0; w < IFH_LEN; w++)
189 		spx5_wr(ifh[w], sparx5, QS_INJ_WR(grp));
190 
191 	/* Write words, round up */
192 	count = DIV_ROUND_UP(skb->len, 4);
193 	buf = skb->data;
194 	for (w = 0; w < count; w++, buf += 4) {
195 		val = get_unaligned((const u32 *)buf);
196 		spx5_wr(val, sparx5, QS_INJ_WR(grp));
197 	}
198 
199 	/* Add padding */
200 	while (w < (60 / 4)) {
201 		spx5_wr(0, sparx5, QS_INJ_WR(grp));
202 		w++;
203 	}
204 
205 	/* Indicate EOF and valid bytes in last word */
206 	spx5_wr(QS_INJ_CTRL_GAP_SIZE_SET(1) |
207 		QS_INJ_CTRL_VLD_BYTES_SET(skb->len < 60 ? 0 : skb->len % 4) |
208 		QS_INJ_CTRL_EOF_SET(1),
209 		sparx5, QS_INJ_CTRL(grp));
210 
211 	/* Add dummy CRC */
212 	spx5_wr(0, sparx5, QS_INJ_WR(grp));
213 	w++;
214 
215 	val = spx5_rd(sparx5, QS_INJ_STATUS);
216 	if (QS_INJ_STATUS_WMARK_REACHED_GET(val) & BIT(grp)) {
217 		struct sparx5_port *port = netdev_priv(ndev);
218 
219 		pr_err_ratelimited("Injection: Watermark reached: 0x%lx\n",
220 				   QS_INJ_STATUS_WMARK_REACHED_GET(val));
221 		netif_stop_queue(ndev);
222 		hrtimer_start(&port->inj_timer, INJ_TIMEOUT_NS,
223 			      HRTIMER_MODE_REL);
224 	}
225 
226 	return NETDEV_TX_OK;
227 }
228 
229 netdev_tx_t sparx5_port_xmit_impl(struct sk_buff *skb, struct net_device *dev)
230 {
231 	struct net_device_stats *stats = &dev->stats;
232 	struct sparx5_port *port = netdev_priv(dev);
233 	struct sparx5 *sparx5 = port->sparx5;
234 	u32 ifh[IFH_LEN];
235 	netdev_tx_t ret;
236 
237 	memset(ifh, 0, IFH_LEN * 4);
238 	sparx5_set_port_ifh(ifh, port->portno);
239 
240 	if (sparx5->ptp && skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) {
241 		if (sparx5_ptp_txtstamp_request(port, skb) < 0)
242 			return NETDEV_TX_BUSY;
243 
244 		sparx5_set_port_ifh_rew_op(ifh, SPARX5_SKB_CB(skb)->rew_op);
245 		sparx5_set_port_ifh_pdu_type(ifh, SPARX5_SKB_CB(skb)->pdu_type);
246 		sparx5_set_port_ifh_pdu_w16_offset(ifh, SPARX5_SKB_CB(skb)->pdu_w16_offset);
247 		sparx5_set_port_ifh_timestamp(ifh, SPARX5_SKB_CB(skb)->ts_id);
248 	}
249 
250 	skb_tx_timestamp(skb);
251 	spin_lock(&sparx5->tx_lock);
252 	if (sparx5->fdma_irq > 0)
253 		ret = sparx5_fdma_xmit(sparx5, ifh, skb);
254 	else
255 		ret = sparx5_inject(sparx5, ifh, skb, dev);
256 	spin_unlock(&sparx5->tx_lock);
257 
258 	if (ret == -EBUSY)
259 		goto busy;
260 	if (ret < 0)
261 		goto drop;
262 
263 	stats->tx_bytes += skb->len;
264 	stats->tx_packets++;
265 	sparx5->tx.packets++;
266 
267 	if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP &&
268 	    SPARX5_SKB_CB(skb)->rew_op == IFH_REW_OP_TWO_STEP_PTP)
269 		return NETDEV_TX_OK;
270 
271 	dev_consume_skb_any(skb);
272 	return NETDEV_TX_OK;
273 drop:
274 	stats->tx_dropped++;
275 	sparx5->tx.dropped++;
276 	dev_kfree_skb_any(skb);
277 	return NETDEV_TX_OK;
278 busy:
279 	if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP &&
280 	    SPARX5_SKB_CB(skb)->rew_op == IFH_REW_OP_TWO_STEP_PTP)
281 		sparx5_ptp_txtstamp_release(port, skb);
282 	return NETDEV_TX_BUSY;
283 }
284 
285 static enum hrtimer_restart sparx5_injection_timeout(struct hrtimer *tmr)
286 {
287 	struct sparx5_port *port = container_of(tmr, struct sparx5_port,
288 						inj_timer);
289 	int grp = INJ_QUEUE;
290 	u32 val;
291 
292 	val = spx5_rd(port->sparx5, QS_INJ_STATUS);
293 	if (QS_INJ_STATUS_WMARK_REACHED_GET(val) & BIT(grp)) {
294 		pr_err_ratelimited("Injection: Reset watermark count\n");
295 		/* Reset Watermark count to restart */
296 		spx5_rmw(DSM_DEV_TX_STOP_WM_CFG_DEV_TX_CNT_CLR_SET(1),
297 			 DSM_DEV_TX_STOP_WM_CFG_DEV_TX_CNT_CLR,
298 			 port->sparx5,
299 			 DSM_DEV_TX_STOP_WM_CFG(port->portno));
300 	}
301 	netif_wake_queue(port->ndev);
302 	return HRTIMER_NORESTART;
303 }
304 
305 int sparx5_manual_injection_mode(struct sparx5 *sparx5)
306 {
307 	const int byte_swap = 1;
308 	int portno;
309 
310 	/* Change mode to manual extraction and injection */
311 	spx5_wr(QS_XTR_GRP_CFG_MODE_SET(1) |
312 		QS_XTR_GRP_CFG_STATUS_WORD_POS_SET(1) |
313 		QS_XTR_GRP_CFG_BYTE_SWAP_SET(byte_swap),
314 		sparx5, QS_XTR_GRP_CFG(XTR_QUEUE));
315 	spx5_wr(QS_INJ_GRP_CFG_MODE_SET(1) |
316 		QS_INJ_GRP_CFG_BYTE_SWAP_SET(byte_swap),
317 		sparx5, QS_INJ_GRP_CFG(INJ_QUEUE));
318 
319 	/* CPU ports capture setup */
320 	for (portno = SPX5_PORT_CPU_0; portno <= SPX5_PORT_CPU_1; portno++) {
321 		/* ASM CPU port: No preamble, IFH, enable padding */
322 		spx5_wr(ASM_PORT_CFG_PAD_ENA_SET(1) |
323 			ASM_PORT_CFG_NO_PREAMBLE_ENA_SET(1) |
324 			ASM_PORT_CFG_INJ_FORMAT_CFG_SET(1), /* 1 = IFH */
325 			sparx5, ASM_PORT_CFG(portno));
326 
327 		/* Reset WM cnt to unclog queued frames */
328 		spx5_rmw(DSM_DEV_TX_STOP_WM_CFG_DEV_TX_CNT_CLR_SET(1),
329 			 DSM_DEV_TX_STOP_WM_CFG_DEV_TX_CNT_CLR,
330 			 sparx5,
331 			 DSM_DEV_TX_STOP_WM_CFG(portno));
332 
333 		/* Set Disassembler Stop Watermark level */
334 		spx5_rmw(DSM_DEV_TX_STOP_WM_CFG_DEV_TX_STOP_WM_SET(0),
335 			 DSM_DEV_TX_STOP_WM_CFG_DEV_TX_STOP_WM,
336 			 sparx5,
337 			 DSM_DEV_TX_STOP_WM_CFG(portno));
338 
339 		/* Enable Disassembler buffer underrun watchdog
340 		 */
341 		spx5_rmw(DSM_BUF_CFG_UNDERFLOW_WATCHDOG_DIS_SET(0),
342 			 DSM_BUF_CFG_UNDERFLOW_WATCHDOG_DIS,
343 			 sparx5,
344 			 DSM_BUF_CFG(portno));
345 	}
346 	return 0;
347 }
348 
349 irqreturn_t sparx5_xtr_handler(int irq, void *_sparx5)
350 {
351 	struct sparx5 *s5 = _sparx5;
352 	int poll = 64;
353 
354 	/* Check data in queue */
355 	while (spx5_rd(s5, QS_XTR_DATA_PRESENT) & BIT(XTR_QUEUE) && poll-- > 0)
356 		sparx5_xtr_grp(s5, XTR_QUEUE, false);
357 
358 	return IRQ_HANDLED;
359 }
360 
361 void sparx5_port_inj_timer_setup(struct sparx5_port *port)
362 {
363 	hrtimer_init(&port->inj_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
364 	port->inj_timer.function = sparx5_injection_timeout;
365 }
366