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