xref: /openbmc/linux/net/ncsi/ncsi-cmd.c (revision 3213486f)
1 /*
2  * Copyright Gavin Shan, IBM Corporation 2016.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  */
9 
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/init.h>
13 #include <linux/etherdevice.h>
14 #include <linux/netdevice.h>
15 #include <linux/skbuff.h>
16 
17 #include <net/ncsi.h>
18 #include <net/net_namespace.h>
19 #include <net/sock.h>
20 #include <net/genetlink.h>
21 
22 #include "internal.h"
23 #include "ncsi-pkt.h"
24 
25 u32 ncsi_calculate_checksum(unsigned char *data, int len)
26 {
27 	u32 checksum = 0;
28 	int i;
29 
30 	for (i = 0; i < len; i += 2)
31 		checksum += (((u32)data[i] << 8) | data[i + 1]);
32 
33 	checksum = (~checksum + 1);
34 	return checksum;
35 }
36 
37 /* This function should be called after the data area has been
38  * populated completely.
39  */
40 static void ncsi_cmd_build_header(struct ncsi_pkt_hdr *h,
41 				  struct ncsi_cmd_arg *nca)
42 {
43 	u32 checksum;
44 	__be32 *pchecksum;
45 
46 	h->mc_id        = 0;
47 	h->revision     = NCSI_PKT_REVISION;
48 	h->reserved     = 0;
49 	h->id           = nca->id;
50 	h->type         = nca->type;
51 	h->channel      = NCSI_TO_CHANNEL(nca->package,
52 					  nca->channel);
53 	h->length       = htons(nca->payload);
54 	h->reserved1[0] = 0;
55 	h->reserved1[1] = 0;
56 
57 	/* Fill with calculated checksum */
58 	checksum = ncsi_calculate_checksum((unsigned char *)h,
59 					   sizeof(*h) + nca->payload);
60 	pchecksum = (__be32 *)((void *)h + sizeof(struct ncsi_pkt_hdr) +
61 		    nca->payload);
62 	*pchecksum = htonl(checksum);
63 }
64 
65 static int ncsi_cmd_handler_default(struct sk_buff *skb,
66 				    struct ncsi_cmd_arg *nca)
67 {
68 	struct ncsi_cmd_pkt *cmd;
69 
70 	cmd = skb_put_zero(skb, sizeof(*cmd));
71 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
72 
73 	return 0;
74 }
75 
76 static int ncsi_cmd_handler_sp(struct sk_buff *skb,
77 			       struct ncsi_cmd_arg *nca)
78 {
79 	struct ncsi_cmd_sp_pkt *cmd;
80 
81 	cmd = skb_put_zero(skb, sizeof(*cmd));
82 	cmd->hw_arbitration = nca->bytes[0];
83 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
84 
85 	return 0;
86 }
87 
88 static int ncsi_cmd_handler_dc(struct sk_buff *skb,
89 			       struct ncsi_cmd_arg *nca)
90 {
91 	struct ncsi_cmd_dc_pkt *cmd;
92 
93 	cmd = skb_put_zero(skb, sizeof(*cmd));
94 	cmd->ald = nca->bytes[0];
95 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
96 
97 	return 0;
98 }
99 
100 static int ncsi_cmd_handler_rc(struct sk_buff *skb,
101 			       struct ncsi_cmd_arg *nca)
102 {
103 	struct ncsi_cmd_rc_pkt *cmd;
104 
105 	cmd = skb_put_zero(skb, sizeof(*cmd));
106 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
107 
108 	return 0;
109 }
110 
111 static int ncsi_cmd_handler_ae(struct sk_buff *skb,
112 			       struct ncsi_cmd_arg *nca)
113 {
114 	struct ncsi_cmd_ae_pkt *cmd;
115 
116 	cmd = skb_put_zero(skb, sizeof(*cmd));
117 	cmd->mc_id = nca->bytes[0];
118 	cmd->mode = htonl(nca->dwords[1]);
119 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
120 
121 	return 0;
122 }
123 
124 static int ncsi_cmd_handler_sl(struct sk_buff *skb,
125 			       struct ncsi_cmd_arg *nca)
126 {
127 	struct ncsi_cmd_sl_pkt *cmd;
128 
129 	cmd = skb_put_zero(skb, sizeof(*cmd));
130 	cmd->mode = htonl(nca->dwords[0]);
131 	cmd->oem_mode = htonl(nca->dwords[1]);
132 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
133 
134 	return 0;
135 }
136 
137 static int ncsi_cmd_handler_svf(struct sk_buff *skb,
138 				struct ncsi_cmd_arg *nca)
139 {
140 	struct ncsi_cmd_svf_pkt *cmd;
141 
142 	cmd = skb_put_zero(skb, sizeof(*cmd));
143 	cmd->vlan = htons(nca->words[1]);
144 	cmd->index = nca->bytes[6];
145 	cmd->enable = nca->bytes[7];
146 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
147 
148 	return 0;
149 }
150 
151 static int ncsi_cmd_handler_ev(struct sk_buff *skb,
152 			       struct ncsi_cmd_arg *nca)
153 {
154 	struct ncsi_cmd_ev_pkt *cmd;
155 
156 	cmd = skb_put_zero(skb, sizeof(*cmd));
157 	cmd->mode = nca->bytes[3];
158 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
159 
160 	return 0;
161 }
162 
163 static int ncsi_cmd_handler_sma(struct sk_buff *skb,
164 				struct ncsi_cmd_arg *nca)
165 {
166 	struct ncsi_cmd_sma_pkt *cmd;
167 	int i;
168 
169 	cmd = skb_put_zero(skb, sizeof(*cmd));
170 	for (i = 0; i < 6; i++)
171 		cmd->mac[i] = nca->bytes[i];
172 	cmd->index = nca->bytes[6];
173 	cmd->at_e = nca->bytes[7];
174 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
175 
176 	return 0;
177 }
178 
179 static int ncsi_cmd_handler_ebf(struct sk_buff *skb,
180 				struct ncsi_cmd_arg *nca)
181 {
182 	struct ncsi_cmd_ebf_pkt *cmd;
183 
184 	cmd = skb_put_zero(skb, sizeof(*cmd));
185 	cmd->mode = htonl(nca->dwords[0]);
186 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
187 
188 	return 0;
189 }
190 
191 static int ncsi_cmd_handler_egmf(struct sk_buff *skb,
192 				 struct ncsi_cmd_arg *nca)
193 {
194 	struct ncsi_cmd_egmf_pkt *cmd;
195 
196 	cmd = skb_put_zero(skb, sizeof(*cmd));
197 	cmd->mode = htonl(nca->dwords[0]);
198 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
199 
200 	return 0;
201 }
202 
203 static int ncsi_cmd_handler_snfc(struct sk_buff *skb,
204 				 struct ncsi_cmd_arg *nca)
205 {
206 	struct ncsi_cmd_snfc_pkt *cmd;
207 
208 	cmd = skb_put_zero(skb, sizeof(*cmd));
209 	cmd->mode = nca->bytes[0];
210 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
211 
212 	return 0;
213 }
214 
215 static int ncsi_cmd_handler_oem(struct sk_buff *skb,
216 				struct ncsi_cmd_arg *nca)
217 {
218 	struct ncsi_cmd_oem_pkt *cmd;
219 	unsigned int len;
220 
221 	len = sizeof(struct ncsi_cmd_pkt_hdr) + 4;
222 	if (nca->payload < 26)
223 		len += 26;
224 	else
225 		len += nca->payload;
226 
227 	cmd = skb_put_zero(skb, len);
228 	memcpy(&cmd->mfr_id, nca->data, nca->payload);
229 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
230 
231 	return 0;
232 }
233 
234 static struct ncsi_cmd_handler {
235 	unsigned char type;
236 	int           payload;
237 	int           (*handler)(struct sk_buff *skb,
238 				 struct ncsi_cmd_arg *nca);
239 } ncsi_cmd_handlers[] = {
240 	{ NCSI_PKT_CMD_CIS,    0, ncsi_cmd_handler_default },
241 	{ NCSI_PKT_CMD_SP,     4, ncsi_cmd_handler_sp      },
242 	{ NCSI_PKT_CMD_DP,     0, ncsi_cmd_handler_default },
243 	{ NCSI_PKT_CMD_EC,     0, ncsi_cmd_handler_default },
244 	{ NCSI_PKT_CMD_DC,     4, ncsi_cmd_handler_dc      },
245 	{ NCSI_PKT_CMD_RC,     4, ncsi_cmd_handler_rc      },
246 	{ NCSI_PKT_CMD_ECNT,   0, ncsi_cmd_handler_default },
247 	{ NCSI_PKT_CMD_DCNT,   0, ncsi_cmd_handler_default },
248 	{ NCSI_PKT_CMD_AE,     8, ncsi_cmd_handler_ae      },
249 	{ NCSI_PKT_CMD_SL,     8, ncsi_cmd_handler_sl      },
250 	{ NCSI_PKT_CMD_GLS,    0, ncsi_cmd_handler_default },
251 	{ NCSI_PKT_CMD_SVF,    8, ncsi_cmd_handler_svf     },
252 	{ NCSI_PKT_CMD_EV,     4, ncsi_cmd_handler_ev      },
253 	{ NCSI_PKT_CMD_DV,     0, ncsi_cmd_handler_default },
254 	{ NCSI_PKT_CMD_SMA,    8, ncsi_cmd_handler_sma     },
255 	{ NCSI_PKT_CMD_EBF,    4, ncsi_cmd_handler_ebf     },
256 	{ NCSI_PKT_CMD_DBF,    0, ncsi_cmd_handler_default },
257 	{ NCSI_PKT_CMD_EGMF,   4, ncsi_cmd_handler_egmf    },
258 	{ NCSI_PKT_CMD_DGMF,   0, ncsi_cmd_handler_default },
259 	{ NCSI_PKT_CMD_SNFC,   4, ncsi_cmd_handler_snfc    },
260 	{ NCSI_PKT_CMD_GVI,    0, ncsi_cmd_handler_default },
261 	{ NCSI_PKT_CMD_GC,     0, ncsi_cmd_handler_default },
262 	{ NCSI_PKT_CMD_GP,     0, ncsi_cmd_handler_default },
263 	{ NCSI_PKT_CMD_GCPS,   0, ncsi_cmd_handler_default },
264 	{ NCSI_PKT_CMD_GNS,    0, ncsi_cmd_handler_default },
265 	{ NCSI_PKT_CMD_GNPTS,  0, ncsi_cmd_handler_default },
266 	{ NCSI_PKT_CMD_GPS,    0, ncsi_cmd_handler_default },
267 	{ NCSI_PKT_CMD_OEM,   -1, ncsi_cmd_handler_oem     },
268 	{ NCSI_PKT_CMD_PLDM,   0, NULL                     },
269 	{ NCSI_PKT_CMD_GPUUID, 0, ncsi_cmd_handler_default }
270 };
271 
272 static struct ncsi_request *ncsi_alloc_command(struct ncsi_cmd_arg *nca)
273 {
274 	struct ncsi_dev_priv *ndp = nca->ndp;
275 	struct ncsi_dev *nd = &ndp->ndev;
276 	struct net_device *dev = nd->dev;
277 	int hlen = LL_RESERVED_SPACE(dev);
278 	int tlen = dev->needed_tailroom;
279 	int len = hlen + tlen;
280 	struct sk_buff *skb;
281 	struct ncsi_request *nr;
282 
283 	nr = ncsi_alloc_request(ndp, nca->req_flags);
284 	if (!nr)
285 		return NULL;
286 
287 	/* NCSI command packet has 16-bytes header, payload, 4 bytes checksum.
288 	 * The packet needs padding if its payload is less than 26 bytes to
289 	 * meet 64 bytes minimal ethernet frame length.
290 	 */
291 	len += sizeof(struct ncsi_cmd_pkt_hdr) + 4;
292 	if (nca->payload < 26)
293 		len += 26;
294 	else
295 		len += nca->payload;
296 
297 	/* Allocate skb */
298 	skb = alloc_skb(len, GFP_ATOMIC);
299 	if (!skb) {
300 		ncsi_free_request(nr);
301 		return NULL;
302 	}
303 
304 	nr->cmd = skb;
305 	skb_reserve(skb, hlen);
306 	skb_reset_network_header(skb);
307 
308 	skb->dev = dev;
309 	skb->protocol = htons(ETH_P_NCSI);
310 
311 	return nr;
312 }
313 
314 int ncsi_xmit_cmd(struct ncsi_cmd_arg *nca)
315 {
316 	struct ncsi_request *nr;
317 	struct ethhdr *eh;
318 	struct ncsi_cmd_handler *nch = NULL;
319 	int i, ret;
320 
321 	/* Search for the handler */
322 	for (i = 0; i < ARRAY_SIZE(ncsi_cmd_handlers); i++) {
323 		if (ncsi_cmd_handlers[i].type == nca->type) {
324 			if (ncsi_cmd_handlers[i].handler)
325 				nch = &ncsi_cmd_handlers[i];
326 			else
327 				nch = NULL;
328 
329 			break;
330 		}
331 	}
332 
333 	if (!nch) {
334 		netdev_err(nca->ndp->ndev.dev,
335 			   "Cannot send packet with type 0x%02x\n", nca->type);
336 		return -ENOENT;
337 	}
338 
339 	/* Get packet payload length and allocate the request
340 	 * It is expected that if length set as negative in
341 	 * handler structure means caller is initializing it
342 	 * and setting length in nca before calling xmit function
343 	 */
344 	if (nch->payload >= 0)
345 		nca->payload = nch->payload;
346 	nr = ncsi_alloc_command(nca);
347 	if (!nr)
348 		return -ENOMEM;
349 
350 	/* track netlink information */
351 	if (nca->req_flags == NCSI_REQ_FLAG_NETLINK_DRIVEN) {
352 		nr->snd_seq = nca->info->snd_seq;
353 		nr->snd_portid = nca->info->snd_portid;
354 		nr->nlhdr = *nca->info->nlhdr;
355 	}
356 
357 	/* Prepare the packet */
358 	nca->id = nr->id;
359 	ret = nch->handler(nr->cmd, nca);
360 	if (ret) {
361 		ncsi_free_request(nr);
362 		return ret;
363 	}
364 
365 	/* Fill the ethernet header */
366 	eh = skb_push(nr->cmd, sizeof(*eh));
367 	eh->h_proto = htons(ETH_P_NCSI);
368 	eth_broadcast_addr(eh->h_dest);
369 	eth_broadcast_addr(eh->h_source);
370 
371 	/* Start the timer for the request that might not have
372 	 * corresponding response. Given NCSI is an internal
373 	 * connection a 1 second delay should be sufficient.
374 	 */
375 	nr->enabled = true;
376 	mod_timer(&nr->timer, jiffies + 1 * HZ);
377 
378 	/* Send NCSI packet */
379 	skb_get(nr->cmd);
380 	ret = dev_queue_xmit(nr->cmd);
381 	if (ret < 0) {
382 		ncsi_free_request(nr);
383 		return ret;
384 	}
385 
386 	return 0;
387 }
388