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 (whats 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 			byte_cnt -= (4 - XTR_VALID_BYTES(val));
117 			eof_flag = true;
118 			break;
119 		case XTR_PRUNED:
120 			/* But get the last 4 bytes as well */
121 			eof_flag = true;
122 			pruned_flag = true;
123 			fallthrough;
124 		case XTR_ESCAPE:
125 			*rxbuf = spx5_rd(sparx5, QS_XTR_RD(grp));
126 			byte_cnt += 4;
127 			rxbuf++;
128 			break;
129 		default:
130 			*rxbuf = val;
131 			byte_cnt += 4;
132 			rxbuf++;
133 		}
134 	}
135 
136 	if (abort_flag || pruned_flag || !eof_flag) {
137 		netdev_err(netdev, "Discarded frame: abort:%d pruned:%d eof:%d\n",
138 			   abort_flag, pruned_flag, eof_flag);
139 		kfree_skb(skb);
140 		netdev->stats.rx_dropped++;
141 		return;
142 	}
143 
144 	/* Everything we see on an interface that is in the HW bridge
145 	 * has already been forwarded
146 	 */
147 	if (test_bit(port->portno, sparx5->bridge_mask))
148 		skb->offload_fwd_mark = 1;
149 
150 	/* Finish up skb */
151 	skb_put(skb, byte_cnt - ETH_FCS_LEN);
152 	eth_skb_pad(skb);
153 	sparx5_ptp_rxtstamp(sparx5, skb, fi.timestamp);
154 	skb->protocol = eth_type_trans(skb, netdev);
155 	netdev->stats.rx_bytes += skb->len;
156 	netdev->stats.rx_packets++;
157 	netif_rx(skb);
158 }
159 
160 static int sparx5_inject(struct sparx5 *sparx5,
161 			 u32 *ifh,
162 			 struct sk_buff *skb,
163 			 struct net_device *ndev)
164 {
165 	int grp = INJ_QUEUE;
166 	u32 val, w, count;
167 	u8 *buf;
168 
169 	val = spx5_rd(sparx5, QS_INJ_STATUS);
170 	if (!(QS_INJ_STATUS_FIFO_RDY_GET(val) & BIT(grp))) {
171 		pr_err_ratelimited("Injection: Queue not ready: 0x%lx\n",
172 				   QS_INJ_STATUS_FIFO_RDY_GET(val));
173 		return -EBUSY;
174 	}
175 
176 	/* Indicate SOF */
177 	spx5_wr(QS_INJ_CTRL_SOF_SET(1) |
178 		QS_INJ_CTRL_GAP_SIZE_SET(1),
179 		sparx5, QS_INJ_CTRL(grp));
180 
181 	/* Write the IFH to the chip. */
182 	for (w = 0; w < IFH_LEN; w++)
183 		spx5_wr(ifh[w], sparx5, QS_INJ_WR(grp));
184 
185 	/* Write words, round up */
186 	count = DIV_ROUND_UP(skb->len, 4);
187 	buf = skb->data;
188 	for (w = 0; w < count; w++, buf += 4) {
189 		val = get_unaligned((const u32 *)buf);
190 		spx5_wr(val, sparx5, QS_INJ_WR(grp));
191 	}
192 
193 	/* Add padding */
194 	while (w < (60 / 4)) {
195 		spx5_wr(0, sparx5, QS_INJ_WR(grp));
196 		w++;
197 	}
198 
199 	/* Indicate EOF and valid bytes in last word */
200 	spx5_wr(QS_INJ_CTRL_GAP_SIZE_SET(1) |
201 		QS_INJ_CTRL_VLD_BYTES_SET(skb->len < 60 ? 0 : skb->len % 4) |
202 		QS_INJ_CTRL_EOF_SET(1),
203 		sparx5, QS_INJ_CTRL(grp));
204 
205 	/* Add dummy CRC */
206 	spx5_wr(0, sparx5, QS_INJ_WR(grp));
207 	w++;
208 
209 	val = spx5_rd(sparx5, QS_INJ_STATUS);
210 	if (QS_INJ_STATUS_WMARK_REACHED_GET(val) & BIT(grp)) {
211 		struct sparx5_port *port = netdev_priv(ndev);
212 
213 		pr_err_ratelimited("Injection: Watermark reached: 0x%lx\n",
214 				   QS_INJ_STATUS_WMARK_REACHED_GET(val));
215 		netif_stop_queue(ndev);
216 		hrtimer_start(&port->inj_timer, INJ_TIMEOUT_NS,
217 			      HRTIMER_MODE_REL);
218 	}
219 
220 	return NETDEV_TX_OK;
221 }
222 
223 int sparx5_port_xmit_impl(struct sk_buff *skb, struct net_device *dev)
224 {
225 	struct net_device_stats *stats = &dev->stats;
226 	struct sparx5_port *port = netdev_priv(dev);
227 	struct sparx5 *sparx5 = port->sparx5;
228 	u32 ifh[IFH_LEN];
229 	int ret;
230 
231 	memset(ifh, 0, IFH_LEN * 4);
232 	sparx5_set_port_ifh(ifh, port->portno);
233 
234 	if (sparx5->ptp && skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) {
235 		ret = sparx5_ptp_txtstamp_request(port, skb);
236 		if (ret)
237 			return ret;
238 
239 		sparx5_set_port_ifh_rew_op(ifh, SPARX5_SKB_CB(skb)->rew_op);
240 		sparx5_set_port_ifh_pdu_type(ifh, SPARX5_SKB_CB(skb)->pdu_type);
241 		sparx5_set_port_ifh_pdu_w16_offset(ifh, SPARX5_SKB_CB(skb)->pdu_w16_offset);
242 		sparx5_set_port_ifh_timestamp(ifh, SPARX5_SKB_CB(skb)->ts_id);
243 	}
244 
245 	skb_tx_timestamp(skb);
246 	if (sparx5->fdma_irq > 0)
247 		ret = sparx5_fdma_xmit(sparx5, ifh, skb);
248 	else
249 		ret = sparx5_inject(sparx5, ifh, skb, dev);
250 
251 	if (ret == NETDEV_TX_OK) {
252 		stats->tx_bytes += skb->len;
253 		stats->tx_packets++;
254 
255 		if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP &&
256 		    SPARX5_SKB_CB(skb)->rew_op == IFH_REW_OP_TWO_STEP_PTP)
257 			return ret;
258 
259 		dev_kfree_skb_any(skb);
260 	} else {
261 		stats->tx_dropped++;
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 			sparx5_ptp_txtstamp_release(port, skb);
266 	}
267 	return ret;
268 }
269 
270 static enum hrtimer_restart sparx5_injection_timeout(struct hrtimer *tmr)
271 {
272 	struct sparx5_port *port = container_of(tmr, struct sparx5_port,
273 						inj_timer);
274 	int grp = INJ_QUEUE;
275 	u32 val;
276 
277 	val = spx5_rd(port->sparx5, QS_INJ_STATUS);
278 	if (QS_INJ_STATUS_WMARK_REACHED_GET(val) & BIT(grp)) {
279 		pr_err_ratelimited("Injection: Reset watermark count\n");
280 		/* Reset Watermark count to restart */
281 		spx5_rmw(DSM_DEV_TX_STOP_WM_CFG_DEV_TX_CNT_CLR_SET(1),
282 			 DSM_DEV_TX_STOP_WM_CFG_DEV_TX_CNT_CLR,
283 			 port->sparx5,
284 			 DSM_DEV_TX_STOP_WM_CFG(port->portno));
285 	}
286 	netif_wake_queue(port->ndev);
287 	return HRTIMER_NORESTART;
288 }
289 
290 int sparx5_manual_injection_mode(struct sparx5 *sparx5)
291 {
292 	const int byte_swap = 1;
293 	int portno;
294 
295 	/* Change mode to manual extraction and injection */
296 	spx5_wr(QS_XTR_GRP_CFG_MODE_SET(1) |
297 		QS_XTR_GRP_CFG_STATUS_WORD_POS_SET(1) |
298 		QS_XTR_GRP_CFG_BYTE_SWAP_SET(byte_swap),
299 		sparx5, QS_XTR_GRP_CFG(XTR_QUEUE));
300 	spx5_wr(QS_INJ_GRP_CFG_MODE_SET(1) |
301 		QS_INJ_GRP_CFG_BYTE_SWAP_SET(byte_swap),
302 		sparx5, QS_INJ_GRP_CFG(INJ_QUEUE));
303 
304 	/* CPU ports capture setup */
305 	for (portno = SPX5_PORT_CPU_0; portno <= SPX5_PORT_CPU_1; portno++) {
306 		/* ASM CPU port: No preamble, IFH, enable padding */
307 		spx5_wr(ASM_PORT_CFG_PAD_ENA_SET(1) |
308 			ASM_PORT_CFG_NO_PREAMBLE_ENA_SET(1) |
309 			ASM_PORT_CFG_INJ_FORMAT_CFG_SET(1), /* 1 = IFH */
310 			sparx5, ASM_PORT_CFG(portno));
311 
312 		/* Reset WM cnt to unclog queued frames */
313 		spx5_rmw(DSM_DEV_TX_STOP_WM_CFG_DEV_TX_CNT_CLR_SET(1),
314 			 DSM_DEV_TX_STOP_WM_CFG_DEV_TX_CNT_CLR,
315 			 sparx5,
316 			 DSM_DEV_TX_STOP_WM_CFG(portno));
317 
318 		/* Set Disassembler Stop Watermark level */
319 		spx5_rmw(DSM_DEV_TX_STOP_WM_CFG_DEV_TX_STOP_WM_SET(0),
320 			 DSM_DEV_TX_STOP_WM_CFG_DEV_TX_STOP_WM,
321 			 sparx5,
322 			 DSM_DEV_TX_STOP_WM_CFG(portno));
323 
324 		/* Enable Disassembler buffer underrun watchdog
325 		 */
326 		spx5_rmw(DSM_BUF_CFG_UNDERFLOW_WATCHDOG_DIS_SET(0),
327 			 DSM_BUF_CFG_UNDERFLOW_WATCHDOG_DIS,
328 			 sparx5,
329 			 DSM_BUF_CFG(portno));
330 	}
331 	return 0;
332 }
333 
334 irqreturn_t sparx5_xtr_handler(int irq, void *_sparx5)
335 {
336 	struct sparx5 *s5 = _sparx5;
337 	int poll = 64;
338 
339 	/* Check data in queue */
340 	while (spx5_rd(s5, QS_XTR_DATA_PRESENT) & BIT(XTR_QUEUE) && poll-- > 0)
341 		sparx5_xtr_grp(s5, XTR_QUEUE, false);
342 
343 	return IRQ_HANDLED;
344 }
345 
346 void sparx5_port_inj_timer_setup(struct sparx5_port *port)
347 {
348 	hrtimer_init(&port->inj_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
349 	port->inj_timer.function = sparx5_injection_timeout;
350 }
351