xref: /openbmc/linux/net/ncsi/ncsi-cmd.c (revision 9a29f5fc)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright Gavin Shan, IBM Corporation 2016.
4  */
5 
6 #include <linux/module.h>
7 #include <linux/kernel.h>
8 #include <linux/init.h>
9 #include <linux/etherdevice.h>
10 #include <linux/netdevice.h>
11 #include <linux/skbuff.h>
12 
13 #include <net/ncsi.h>
14 #include <net/net_namespace.h>
15 #include <net/sock.h>
16 #include <net/genetlink.h>
17 
18 #include "internal.h"
19 #include "ncsi-pkt.h"
20 
21 static const int padding_bytes = 26;
22 
23 u32 ncsi_calculate_checksum(unsigned char *data, int len)
24 {
25 	u32 checksum = 0;
26 	int i;
27 
28 	for (i = 0; i < len; i += 2)
29 		checksum += (((u32)data[i] << 8) | data[i + 1]);
30 
31 	checksum = (~checksum + 1);
32 	return checksum;
33 }
34 
35 /* This function should be called after the data area has been
36  * populated completely.
37  */
38 static void ncsi_cmd_build_header(struct ncsi_pkt_hdr *h,
39 				  struct ncsi_cmd_arg *nca)
40 {
41 	u32 checksum;
42 	__be32 *pchecksum;
43 
44 	h->mc_id        = 0;
45 	h->revision     = NCSI_PKT_REVISION;
46 	h->reserved     = 0;
47 	h->id           = nca->id;
48 	h->type         = nca->type;
49 	h->channel      = NCSI_TO_CHANNEL(nca->package,
50 					  nca->channel);
51 	h->length       = htons(nca->payload);
52 	h->reserved1[0] = 0;
53 	h->reserved1[1] = 0;
54 
55 	/* Fill with calculated checksum */
56 	checksum = ncsi_calculate_checksum((unsigned char *)h,
57 					   sizeof(*h) + nca->payload);
58 	pchecksum = (__be32 *)((void *)h + sizeof(struct ncsi_pkt_hdr) +
59 		    ALIGN(nca->payload, 4));
60 	*pchecksum = htonl(checksum);
61 }
62 
63 static int ncsi_cmd_handler_default(struct sk_buff *skb,
64 				    struct ncsi_cmd_arg *nca)
65 {
66 	struct ncsi_cmd_pkt *cmd;
67 
68 	cmd = skb_put_zero(skb, sizeof(*cmd));
69 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
70 
71 	return 0;
72 }
73 
74 static int ncsi_cmd_handler_sp(struct sk_buff *skb,
75 			       struct ncsi_cmd_arg *nca)
76 {
77 	struct ncsi_cmd_sp_pkt *cmd;
78 
79 	cmd = skb_put_zero(skb, sizeof(*cmd));
80 	cmd->hw_arbitration = nca->bytes[0];
81 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
82 
83 	return 0;
84 }
85 
86 static int ncsi_cmd_handler_dc(struct sk_buff *skb,
87 			       struct ncsi_cmd_arg *nca)
88 {
89 	struct ncsi_cmd_dc_pkt *cmd;
90 
91 	cmd = skb_put_zero(skb, sizeof(*cmd));
92 	cmd->ald = nca->bytes[0];
93 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
94 
95 	return 0;
96 }
97 
98 static int ncsi_cmd_handler_rc(struct sk_buff *skb,
99 			       struct ncsi_cmd_arg *nca)
100 {
101 	struct ncsi_cmd_rc_pkt *cmd;
102 
103 	cmd = skb_put_zero(skb, sizeof(*cmd));
104 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
105 
106 	return 0;
107 }
108 
109 static int ncsi_cmd_handler_ae(struct sk_buff *skb,
110 			       struct ncsi_cmd_arg *nca)
111 {
112 	struct ncsi_cmd_ae_pkt *cmd;
113 
114 	cmd = skb_put_zero(skb, sizeof(*cmd));
115 	cmd->mc_id = nca->bytes[0];
116 	cmd->mode = htonl(nca->dwords[1]);
117 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
118 
119 	return 0;
120 }
121 
122 static int ncsi_cmd_handler_sl(struct sk_buff *skb,
123 			       struct ncsi_cmd_arg *nca)
124 {
125 	struct ncsi_cmd_sl_pkt *cmd;
126 
127 	cmd = skb_put_zero(skb, sizeof(*cmd));
128 	cmd->mode = htonl(nca->dwords[0]);
129 	cmd->oem_mode = htonl(nca->dwords[1]);
130 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
131 
132 	return 0;
133 }
134 
135 static int ncsi_cmd_handler_svf(struct sk_buff *skb,
136 				struct ncsi_cmd_arg *nca)
137 {
138 	struct ncsi_cmd_svf_pkt *cmd;
139 
140 	cmd = skb_put_zero(skb, sizeof(*cmd));
141 	cmd->vlan = htons(nca->words[1]);
142 	cmd->index = nca->bytes[6];
143 	cmd->enable = nca->bytes[7];
144 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
145 
146 	return 0;
147 }
148 
149 static int ncsi_cmd_handler_ev(struct sk_buff *skb,
150 			       struct ncsi_cmd_arg *nca)
151 {
152 	struct ncsi_cmd_ev_pkt *cmd;
153 
154 	cmd = skb_put_zero(skb, sizeof(*cmd));
155 	cmd->mode = nca->bytes[3];
156 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
157 
158 	return 0;
159 }
160 
161 static int ncsi_cmd_handler_sma(struct sk_buff *skb,
162 				struct ncsi_cmd_arg *nca)
163 {
164 	struct ncsi_cmd_sma_pkt *cmd;
165 	int i;
166 
167 	cmd = skb_put_zero(skb, sizeof(*cmd));
168 	for (i = 0; i < 6; i++)
169 		cmd->mac[i] = nca->bytes[i];
170 	cmd->index = nca->bytes[6];
171 	cmd->at_e = nca->bytes[7];
172 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
173 
174 	return 0;
175 }
176 
177 static int ncsi_cmd_handler_ebf(struct sk_buff *skb,
178 				struct ncsi_cmd_arg *nca)
179 {
180 	struct ncsi_cmd_ebf_pkt *cmd;
181 
182 	cmd = skb_put_zero(skb, sizeof(*cmd));
183 	cmd->mode = htonl(nca->dwords[0]);
184 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
185 
186 	return 0;
187 }
188 
189 static int ncsi_cmd_handler_egmf(struct sk_buff *skb,
190 				 struct ncsi_cmd_arg *nca)
191 {
192 	struct ncsi_cmd_egmf_pkt *cmd;
193 
194 	cmd = skb_put_zero(skb, sizeof(*cmd));
195 	cmd->mode = htonl(nca->dwords[0]);
196 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
197 
198 	return 0;
199 }
200 
201 static int ncsi_cmd_handler_snfc(struct sk_buff *skb,
202 				 struct ncsi_cmd_arg *nca)
203 {
204 	struct ncsi_cmd_snfc_pkt *cmd;
205 
206 	cmd = skb_put_zero(skb, sizeof(*cmd));
207 	cmd->mode = nca->bytes[0];
208 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
209 
210 	return 0;
211 }
212 
213 static int ncsi_cmd_handler_oem(struct sk_buff *skb,
214 				struct ncsi_cmd_arg *nca)
215 {
216 	struct ncsi_cmd_oem_pkt *cmd;
217 	unsigned int len;
218 	int payload;
219 	/* NC-SI spec DSP_0222_1.2.0, section 8.2.2.2
220 	 * requires payload to be padded with 0 to
221 	 * 32-bit boundary before the checksum field.
222 	 * Ensure the padding bytes are accounted for in
223 	 * skb allocation
224 	 */
225 
226 	payload = ALIGN(nca->payload, 4);
227 	len = sizeof(struct ncsi_cmd_pkt_hdr) + 4;
228 	len += max(payload, padding_bytes);
229 
230 	cmd = skb_put_zero(skb, len);
231 	memcpy(&cmd->mfr_id, nca->data, nca->payload);
232 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
233 
234 	return 0;
235 }
236 
237 static struct ncsi_cmd_handler {
238 	unsigned char type;
239 	int           payload;
240 	int           (*handler)(struct sk_buff *skb,
241 				 struct ncsi_cmd_arg *nca);
242 } ncsi_cmd_handlers[] = {
243 	{ NCSI_PKT_CMD_CIS,    0, ncsi_cmd_handler_default },
244 	{ NCSI_PKT_CMD_SP,     4, ncsi_cmd_handler_sp      },
245 	{ NCSI_PKT_CMD_DP,     0, ncsi_cmd_handler_default },
246 	{ NCSI_PKT_CMD_EC,     0, ncsi_cmd_handler_default },
247 	{ NCSI_PKT_CMD_DC,     4, ncsi_cmd_handler_dc      },
248 	{ NCSI_PKT_CMD_RC,     4, ncsi_cmd_handler_rc      },
249 	{ NCSI_PKT_CMD_ECNT,   0, ncsi_cmd_handler_default },
250 	{ NCSI_PKT_CMD_DCNT,   0, ncsi_cmd_handler_default },
251 	{ NCSI_PKT_CMD_AE,     8, ncsi_cmd_handler_ae      },
252 	{ NCSI_PKT_CMD_SL,     8, ncsi_cmd_handler_sl      },
253 	{ NCSI_PKT_CMD_GLS,    0, ncsi_cmd_handler_default },
254 	{ NCSI_PKT_CMD_SVF,    8, ncsi_cmd_handler_svf     },
255 	{ NCSI_PKT_CMD_EV,     4, ncsi_cmd_handler_ev      },
256 	{ NCSI_PKT_CMD_DV,     0, ncsi_cmd_handler_default },
257 	{ NCSI_PKT_CMD_SMA,    8, ncsi_cmd_handler_sma     },
258 	{ NCSI_PKT_CMD_EBF,    4, ncsi_cmd_handler_ebf     },
259 	{ NCSI_PKT_CMD_DBF,    0, ncsi_cmd_handler_default },
260 	{ NCSI_PKT_CMD_EGMF,   4, ncsi_cmd_handler_egmf    },
261 	{ NCSI_PKT_CMD_DGMF,   0, ncsi_cmd_handler_default },
262 	{ NCSI_PKT_CMD_SNFC,   4, ncsi_cmd_handler_snfc    },
263 	{ NCSI_PKT_CMD_GVI,    0, ncsi_cmd_handler_default },
264 	{ NCSI_PKT_CMD_GC,     0, ncsi_cmd_handler_default },
265 	{ NCSI_PKT_CMD_GP,     0, ncsi_cmd_handler_default },
266 	{ NCSI_PKT_CMD_GCPS,   0, ncsi_cmd_handler_default },
267 	{ NCSI_PKT_CMD_GNS,    0, ncsi_cmd_handler_default },
268 	{ NCSI_PKT_CMD_GNPTS,  0, ncsi_cmd_handler_default },
269 	{ NCSI_PKT_CMD_GPS,    0, ncsi_cmd_handler_default },
270 	{ NCSI_PKT_CMD_OEM,   -1, ncsi_cmd_handler_oem     },
271 	{ NCSI_PKT_CMD_PLDM,   0, NULL                     },
272 	{ NCSI_PKT_CMD_GPUUID, 0, ncsi_cmd_handler_default }
273 };
274 
275 static struct ncsi_request *ncsi_alloc_command(struct ncsi_cmd_arg *nca)
276 {
277 	struct ncsi_dev_priv *ndp = nca->ndp;
278 	struct ncsi_dev *nd = &ndp->ndev;
279 	struct net_device *dev = nd->dev;
280 	int hlen = LL_RESERVED_SPACE(dev);
281 	int tlen = dev->needed_tailroom;
282 	int payload;
283 	int len = hlen + tlen;
284 	struct sk_buff *skb;
285 	struct ncsi_request *nr;
286 
287 	nr = ncsi_alloc_request(ndp, nca->req_flags);
288 	if (!nr)
289 		return NULL;
290 
291 	/* NCSI command packet has 16-bytes header, payload, 4 bytes checksum.
292 	 * Payload needs padding so that the checksum field following payload is
293 	 * aligned to 32-bit boundary.
294 	 * The packet needs padding if its payload is less than 26 bytes to
295 	 * meet 64 bytes minimal ethernet frame length.
296 	 */
297 	len += sizeof(struct ncsi_cmd_pkt_hdr) + 4;
298 	payload = ALIGN(nca->payload, 4);
299 	len += max(payload, padding_bytes);
300 
301 	/* Allocate skb */
302 	skb = alloc_skb(len, GFP_ATOMIC);
303 	if (!skb) {
304 		ncsi_free_request(nr);
305 		return NULL;
306 	}
307 
308 	nr->cmd = skb;
309 	skb_reserve(skb, hlen);
310 	skb_reset_network_header(skb);
311 
312 	skb->dev = dev;
313 	skb->protocol = htons(ETH_P_NCSI);
314 
315 	return nr;
316 }
317 
318 int ncsi_xmit_cmd(struct ncsi_cmd_arg *nca)
319 {
320 	struct ncsi_cmd_handler *nch = NULL;
321 	struct ncsi_request *nr;
322 	unsigned char type;
323 	struct ethhdr *eh;
324 	int i, ret;
325 
326 	/* Use OEM generic handler for Netlink request */
327 	if (nca->req_flags == NCSI_REQ_FLAG_NETLINK_DRIVEN)
328 		type = NCSI_PKT_CMD_OEM;
329 	else
330 		type = nca->type;
331 
332 	/* Search for the handler */
333 	for (i = 0; i < ARRAY_SIZE(ncsi_cmd_handlers); i++) {
334 		if (ncsi_cmd_handlers[i].type == type) {
335 			if (ncsi_cmd_handlers[i].handler)
336 				nch = &ncsi_cmd_handlers[i];
337 			else
338 				nch = NULL;
339 
340 			break;
341 		}
342 	}
343 
344 	if (!nch) {
345 		netdev_err(nca->ndp->ndev.dev,
346 			   "Cannot send packet with type 0x%02x\n", nca->type);
347 		return -ENOENT;
348 	}
349 
350 	/* Get packet payload length and allocate the request
351 	 * It is expected that if length set as negative in
352 	 * handler structure means caller is initializing it
353 	 * and setting length in nca before calling xmit function
354 	 */
355 	if (nch->payload >= 0)
356 		nca->payload = nch->payload;
357 	nr = ncsi_alloc_command(nca);
358 	if (!nr)
359 		return -ENOMEM;
360 
361 	/* track netlink information */
362 	if (nca->req_flags == NCSI_REQ_FLAG_NETLINK_DRIVEN) {
363 		nr->snd_seq = nca->info->snd_seq;
364 		nr->snd_portid = nca->info->snd_portid;
365 		nr->nlhdr = *nca->info->nlhdr;
366 	}
367 
368 	/* Prepare the packet */
369 	nca->id = nr->id;
370 	ret = nch->handler(nr->cmd, nca);
371 	if (ret) {
372 		ncsi_free_request(nr);
373 		return ret;
374 	}
375 
376 	/* Fill the ethernet header */
377 	eh = skb_push(nr->cmd, sizeof(*eh));
378 	eh->h_proto = htons(ETH_P_NCSI);
379 	eth_broadcast_addr(eh->h_dest);
380 
381 	/* If mac address received from device then use it for
382 	 * source address as unicast address else use broadcast
383 	 * address as source address
384 	 */
385 	if (nca->ndp->gma_flag == 1)
386 		memcpy(eh->h_source, nca->ndp->ndev.dev->dev_addr, ETH_ALEN);
387 	else
388 		eth_broadcast_addr(eh->h_source);
389 
390 	/* Start the timer for the request that might not have
391 	 * corresponding response. Given NCSI is an internal
392 	 * connection a 1 second delay should be sufficient.
393 	 */
394 	nr->enabled = true;
395 	mod_timer(&nr->timer, jiffies + 1 * HZ);
396 
397 	/* Send NCSI packet */
398 	skb_get(nr->cmd);
399 	ret = dev_queue_xmit(nr->cmd);
400 	if (ret < 0) {
401 		ncsi_free_request(nr);
402 		return ret;
403 	}
404 
405 	return 0;
406 }
407