xref: /openbmc/linux/net/ncsi/ncsi-cmd.c (revision bc5aa3a0)
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 
21 #include "internal.h"
22 #include "ncsi-pkt.h"
23 
24 u32 ncsi_calculate_checksum(unsigned char *data, int len)
25 {
26 	u32 checksum = 0;
27 	int i;
28 
29 	for (i = 0; i < len; i += 2)
30 		checksum += (((u32)data[i] << 8) | data[i + 1]);
31 
32 	checksum = (~checksum + 1);
33 	return checksum;
34 }
35 
36 /* This function should be called after the data area has been
37  * populated completely.
38  */
39 static void ncsi_cmd_build_header(struct ncsi_pkt_hdr *h,
40 				  struct ncsi_cmd_arg *nca)
41 {
42 	u32 checksum;
43 	__be32 *pchecksum;
44 
45 	h->mc_id        = 0;
46 	h->revision     = NCSI_PKT_REVISION;
47 	h->reserved     = 0;
48 	h->id           = nca->id;
49 	h->type         = nca->type;
50 	h->channel      = NCSI_TO_CHANNEL(nca->package,
51 					  nca->channel);
52 	h->length       = htons(nca->payload);
53 	h->reserved1[0] = 0;
54 	h->reserved1[1] = 0;
55 
56 	/* Fill with calculated checksum */
57 	checksum = ncsi_calculate_checksum((unsigned char *)h,
58 					   sizeof(*h) + nca->payload);
59 	pchecksum = (__be32 *)((void *)h + sizeof(struct ncsi_pkt_hdr) +
60 		    nca->payload);
61 	*pchecksum = htonl(checksum);
62 }
63 
64 static int ncsi_cmd_handler_default(struct sk_buff *skb,
65 				    struct ncsi_cmd_arg *nca)
66 {
67 	struct ncsi_cmd_pkt *cmd;
68 
69 	cmd = (struct ncsi_cmd_pkt *)skb_put(skb, sizeof(*cmd));
70 	memset(cmd, 0, 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 = (struct ncsi_cmd_sp_pkt *)skb_put(skb, sizeof(*cmd));
82 	memset(cmd, 0, sizeof(*cmd));
83 	cmd->hw_arbitration = nca->bytes[0];
84 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
85 
86 	return 0;
87 }
88 
89 static int ncsi_cmd_handler_dc(struct sk_buff *skb,
90 			       struct ncsi_cmd_arg *nca)
91 {
92 	struct ncsi_cmd_dc_pkt *cmd;
93 
94 	cmd = (struct ncsi_cmd_dc_pkt *)skb_put(skb, sizeof(*cmd));
95 	memset(cmd, 0, sizeof(*cmd));
96 	cmd->ald = nca->bytes[0];
97 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
98 
99 	return 0;
100 }
101 
102 static int ncsi_cmd_handler_rc(struct sk_buff *skb,
103 			       struct ncsi_cmd_arg *nca)
104 {
105 	struct ncsi_cmd_rc_pkt *cmd;
106 
107 	cmd = (struct ncsi_cmd_rc_pkt *)skb_put(skb, sizeof(*cmd));
108 	memset(cmd, 0, sizeof(*cmd));
109 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
110 
111 	return 0;
112 }
113 
114 static int ncsi_cmd_handler_ae(struct sk_buff *skb,
115 			       struct ncsi_cmd_arg *nca)
116 {
117 	struct ncsi_cmd_ae_pkt *cmd;
118 
119 	cmd = (struct ncsi_cmd_ae_pkt *)skb_put(skb, sizeof(*cmd));
120 	memset(cmd, 0, sizeof(*cmd));
121 	cmd->mc_id = nca->bytes[0];
122 	cmd->mode = htonl(nca->dwords[1]);
123 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
124 
125 	return 0;
126 }
127 
128 static int ncsi_cmd_handler_sl(struct sk_buff *skb,
129 			       struct ncsi_cmd_arg *nca)
130 {
131 	struct ncsi_cmd_sl_pkt *cmd;
132 
133 	cmd = (struct ncsi_cmd_sl_pkt *)skb_put(skb, sizeof(*cmd));
134 	memset(cmd, 0, sizeof(*cmd));
135 	cmd->mode = htonl(nca->dwords[0]);
136 	cmd->oem_mode = htonl(nca->dwords[1]);
137 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
138 
139 	return 0;
140 }
141 
142 static int ncsi_cmd_handler_svf(struct sk_buff *skb,
143 				struct ncsi_cmd_arg *nca)
144 {
145 	struct ncsi_cmd_svf_pkt *cmd;
146 
147 	cmd = (struct ncsi_cmd_svf_pkt *)skb_put(skb, sizeof(*cmd));
148 	memset(cmd, 0, sizeof(*cmd));
149 	cmd->vlan = htons(nca->words[0]);
150 	cmd->index = nca->bytes[2];
151 	cmd->enable = nca->bytes[3];
152 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
153 
154 	return 0;
155 }
156 
157 static int ncsi_cmd_handler_ev(struct sk_buff *skb,
158 			       struct ncsi_cmd_arg *nca)
159 {
160 	struct ncsi_cmd_ev_pkt *cmd;
161 
162 	cmd = (struct ncsi_cmd_ev_pkt *)skb_put(skb, sizeof(*cmd));
163 	memset(cmd, 0, sizeof(*cmd));
164 	cmd->mode = nca->bytes[0];
165 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
166 
167 	return 0;
168 }
169 
170 static int ncsi_cmd_handler_sma(struct sk_buff *skb,
171 				struct ncsi_cmd_arg *nca)
172 {
173 	struct ncsi_cmd_sma_pkt *cmd;
174 	int i;
175 
176 	cmd = (struct ncsi_cmd_sma_pkt *)skb_put(skb, sizeof(*cmd));
177 	memset(cmd, 0, sizeof(*cmd));
178 	for (i = 0; i < 6; i++)
179 		cmd->mac[i] = nca->bytes[i];
180 	cmd->index = nca->bytes[6];
181 	cmd->at_e = nca->bytes[7];
182 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
183 
184 	return 0;
185 }
186 
187 static int ncsi_cmd_handler_ebf(struct sk_buff *skb,
188 				struct ncsi_cmd_arg *nca)
189 {
190 	struct ncsi_cmd_ebf_pkt *cmd;
191 
192 	cmd = (struct ncsi_cmd_ebf_pkt *)skb_put(skb, sizeof(*cmd));
193 	memset(cmd, 0, sizeof(*cmd));
194 	cmd->mode = htonl(nca->dwords[0]);
195 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
196 
197 	return 0;
198 }
199 
200 static int ncsi_cmd_handler_egmf(struct sk_buff *skb,
201 				 struct ncsi_cmd_arg *nca)
202 {
203 	struct ncsi_cmd_egmf_pkt *cmd;
204 
205 	cmd = (struct ncsi_cmd_egmf_pkt *)skb_put(skb, sizeof(*cmd));
206 	memset(cmd, 0, sizeof(*cmd));
207 	cmd->mode = htonl(nca->dwords[0]);
208 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
209 
210 	return 0;
211 }
212 
213 static int ncsi_cmd_handler_snfc(struct sk_buff *skb,
214 				 struct ncsi_cmd_arg *nca)
215 {
216 	struct ncsi_cmd_snfc_pkt *cmd;
217 
218 	cmd = (struct ncsi_cmd_snfc_pkt *)skb_put(skb, sizeof(*cmd));
219 	memset(cmd, 0, sizeof(*cmd));
220 	cmd->mode = nca->bytes[0];
221 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
222 
223 	return 0;
224 }
225 
226 static struct ncsi_cmd_handler {
227 	unsigned char type;
228 	int           payload;
229 	int           (*handler)(struct sk_buff *skb,
230 				 struct ncsi_cmd_arg *nca);
231 } ncsi_cmd_handlers[] = {
232 	{ NCSI_PKT_CMD_CIS,    0, ncsi_cmd_handler_default },
233 	{ NCSI_PKT_CMD_SP,     4, ncsi_cmd_handler_sp      },
234 	{ NCSI_PKT_CMD_DP,     0, ncsi_cmd_handler_default },
235 	{ NCSI_PKT_CMD_EC,     0, ncsi_cmd_handler_default },
236 	{ NCSI_PKT_CMD_DC,     4, ncsi_cmd_handler_dc      },
237 	{ NCSI_PKT_CMD_RC,     4, ncsi_cmd_handler_rc      },
238 	{ NCSI_PKT_CMD_ECNT,   0, ncsi_cmd_handler_default },
239 	{ NCSI_PKT_CMD_DCNT,   0, ncsi_cmd_handler_default },
240 	{ NCSI_PKT_CMD_AE,     8, ncsi_cmd_handler_ae      },
241 	{ NCSI_PKT_CMD_SL,     8, ncsi_cmd_handler_sl      },
242 	{ NCSI_PKT_CMD_GLS,    0, ncsi_cmd_handler_default },
243 	{ NCSI_PKT_CMD_SVF,    4, ncsi_cmd_handler_svf     },
244 	{ NCSI_PKT_CMD_EV,     4, ncsi_cmd_handler_ev      },
245 	{ NCSI_PKT_CMD_DV,     0, ncsi_cmd_handler_default },
246 	{ NCSI_PKT_CMD_SMA,    8, ncsi_cmd_handler_sma     },
247 	{ NCSI_PKT_CMD_EBF,    4, ncsi_cmd_handler_ebf     },
248 	{ NCSI_PKT_CMD_DBF,    0, ncsi_cmd_handler_default },
249 	{ NCSI_PKT_CMD_EGMF,   4, ncsi_cmd_handler_egmf    },
250 	{ NCSI_PKT_CMD_DGMF,   0, ncsi_cmd_handler_default },
251 	{ NCSI_PKT_CMD_SNFC,   4, ncsi_cmd_handler_snfc    },
252 	{ NCSI_PKT_CMD_GVI,    0, ncsi_cmd_handler_default },
253 	{ NCSI_PKT_CMD_GC,     0, ncsi_cmd_handler_default },
254 	{ NCSI_PKT_CMD_GP,     0, ncsi_cmd_handler_default },
255 	{ NCSI_PKT_CMD_GCPS,   0, ncsi_cmd_handler_default },
256 	{ NCSI_PKT_CMD_GNS,    0, ncsi_cmd_handler_default },
257 	{ NCSI_PKT_CMD_GNPTS,  0, ncsi_cmd_handler_default },
258 	{ NCSI_PKT_CMD_GPS,    0, ncsi_cmd_handler_default },
259 	{ NCSI_PKT_CMD_OEM,    0, NULL                     },
260 	{ NCSI_PKT_CMD_PLDM,   0, NULL                     },
261 	{ NCSI_PKT_CMD_GPUUID, 0, ncsi_cmd_handler_default }
262 };
263 
264 static struct ncsi_request *ncsi_alloc_command(struct ncsi_cmd_arg *nca)
265 {
266 	struct ncsi_dev_priv *ndp = nca->ndp;
267 	struct ncsi_dev *nd = &ndp->ndev;
268 	struct net_device *dev = nd->dev;
269 	int hlen = LL_RESERVED_SPACE(dev);
270 	int tlen = dev->needed_tailroom;
271 	int len = hlen + tlen;
272 	struct sk_buff *skb;
273 	struct ncsi_request *nr;
274 
275 	nr = ncsi_alloc_request(ndp, nca->driven);
276 	if (!nr)
277 		return NULL;
278 
279 	/* NCSI command packet has 16-bytes header, payload, 4 bytes checksum.
280 	 * The packet needs padding if its payload is less than 26 bytes to
281 	 * meet 64 bytes minimal ethernet frame length.
282 	 */
283 	len += sizeof(struct ncsi_cmd_pkt_hdr) + 4;
284 	if (nca->payload < 26)
285 		len += 26;
286 	else
287 		len += nca->payload;
288 
289 	/* Allocate skb */
290 	skb = alloc_skb(len, GFP_ATOMIC);
291 	if (!skb) {
292 		ncsi_free_request(nr);
293 		return NULL;
294 	}
295 
296 	nr->cmd = skb;
297 	skb_reserve(skb, hlen);
298 	skb_reset_network_header(skb);
299 
300 	skb->dev = dev;
301 	skb->protocol = htons(ETH_P_NCSI);
302 
303 	return nr;
304 }
305 
306 int ncsi_xmit_cmd(struct ncsi_cmd_arg *nca)
307 {
308 	struct ncsi_request *nr;
309 	struct ethhdr *eh;
310 	struct ncsi_cmd_handler *nch = NULL;
311 	int i, ret;
312 
313 	/* Search for the handler */
314 	for (i = 0; i < ARRAY_SIZE(ncsi_cmd_handlers); i++) {
315 		if (ncsi_cmd_handlers[i].type == nca->type) {
316 			if (ncsi_cmd_handlers[i].handler)
317 				nch = &ncsi_cmd_handlers[i];
318 			else
319 				nch = NULL;
320 
321 			break;
322 		}
323 	}
324 
325 	if (!nch) {
326 		netdev_err(nca->ndp->ndev.dev,
327 			   "Cannot send packet with type 0x%02x\n", nca->type);
328 		return -ENOENT;
329 	}
330 
331 	/* Get packet payload length and allocate the request */
332 	nca->payload = nch->payload;
333 	nr = ncsi_alloc_command(nca);
334 	if (!nr)
335 		return -ENOMEM;
336 
337 	/* Prepare the packet */
338 	nca->id = nr->id;
339 	ret = nch->handler(nr->cmd, nca);
340 	if (ret) {
341 		ncsi_free_request(nr);
342 		return ret;
343 	}
344 
345 	/* Fill the ethernet header */
346 	eh = (struct ethhdr *)skb_push(nr->cmd, sizeof(*eh));
347 	eh->h_proto = htons(ETH_P_NCSI);
348 	eth_broadcast_addr(eh->h_dest);
349 	eth_broadcast_addr(eh->h_source);
350 
351 	/* Start the timer for the request that might not have
352 	 * corresponding response. Given NCSI is an internal
353 	 * connection a 1 second delay should be sufficient.
354 	 */
355 	nr->enabled = true;
356 	mod_timer(&nr->timer, jiffies + 1 * HZ);
357 
358 	/* Send NCSI packet */
359 	skb_get(nr->cmd);
360 	ret = dev_queue_xmit(nr->cmd);
361 	if (ret < 0) {
362 		ncsi_free_request(nr);
363 		return ret;
364 	}
365 
366 	return 0;
367 }
368