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