xref: /openbmc/linux/net/ncsi/ncsi-cmd.c (revision e3b9f1e8)
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 = skb_put_zero(skb, sizeof(*cmd));
70 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
71 
72 	return 0;
73 }
74 
75 static int ncsi_cmd_handler_sp(struct sk_buff *skb,
76 			       struct ncsi_cmd_arg *nca)
77 {
78 	struct ncsi_cmd_sp_pkt *cmd;
79 
80 	cmd = skb_put_zero(skb, sizeof(*cmd));
81 	cmd->hw_arbitration = nca->bytes[0];
82 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
83 
84 	return 0;
85 }
86 
87 static int ncsi_cmd_handler_dc(struct sk_buff *skb,
88 			       struct ncsi_cmd_arg *nca)
89 {
90 	struct ncsi_cmd_dc_pkt *cmd;
91 
92 	cmd = skb_put_zero(skb, sizeof(*cmd));
93 	cmd->ald = nca->bytes[0];
94 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
95 
96 	return 0;
97 }
98 
99 static int ncsi_cmd_handler_rc(struct sk_buff *skb,
100 			       struct ncsi_cmd_arg *nca)
101 {
102 	struct ncsi_cmd_rc_pkt *cmd;
103 
104 	cmd = skb_put_zero(skb, sizeof(*cmd));
105 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
106 
107 	return 0;
108 }
109 
110 static int ncsi_cmd_handler_ae(struct sk_buff *skb,
111 			       struct ncsi_cmd_arg *nca)
112 {
113 	struct ncsi_cmd_ae_pkt *cmd;
114 
115 	cmd = skb_put_zero(skb, sizeof(*cmd));
116 	cmd->mc_id = nca->bytes[0];
117 	cmd->mode = htonl(nca->dwords[1]);
118 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
119 
120 	return 0;
121 }
122 
123 static int ncsi_cmd_handler_sl(struct sk_buff *skb,
124 			       struct ncsi_cmd_arg *nca)
125 {
126 	struct ncsi_cmd_sl_pkt *cmd;
127 
128 	cmd = skb_put_zero(skb, sizeof(*cmd));
129 	cmd->mode = htonl(nca->dwords[0]);
130 	cmd->oem_mode = htonl(nca->dwords[1]);
131 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
132 
133 	return 0;
134 }
135 
136 static int ncsi_cmd_handler_svf(struct sk_buff *skb,
137 				struct ncsi_cmd_arg *nca)
138 {
139 	struct ncsi_cmd_svf_pkt *cmd;
140 
141 	cmd = skb_put_zero(skb, sizeof(*cmd));
142 	cmd->vlan = htons(nca->words[1]);
143 	cmd->index = nca->bytes[6];
144 	cmd->enable = nca->bytes[7];
145 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
146 
147 	return 0;
148 }
149 
150 static int ncsi_cmd_handler_ev(struct sk_buff *skb,
151 			       struct ncsi_cmd_arg *nca)
152 {
153 	struct ncsi_cmd_ev_pkt *cmd;
154 
155 	cmd = skb_put_zero(skb, sizeof(*cmd));
156 	cmd->mode = nca->bytes[3];
157 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
158 
159 	return 0;
160 }
161 
162 static int ncsi_cmd_handler_sma(struct sk_buff *skb,
163 				struct ncsi_cmd_arg *nca)
164 {
165 	struct ncsi_cmd_sma_pkt *cmd;
166 	int i;
167 
168 	cmd = skb_put_zero(skb, sizeof(*cmd));
169 	for (i = 0; i < 6; i++)
170 		cmd->mac[i] = nca->bytes[i];
171 	cmd->index = nca->bytes[6];
172 	cmd->at_e = nca->bytes[7];
173 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
174 
175 	return 0;
176 }
177 
178 static int ncsi_cmd_handler_ebf(struct sk_buff *skb,
179 				struct ncsi_cmd_arg *nca)
180 {
181 	struct ncsi_cmd_ebf_pkt *cmd;
182 
183 	cmd = skb_put_zero(skb, sizeof(*cmd));
184 	cmd->mode = htonl(nca->dwords[0]);
185 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
186 
187 	return 0;
188 }
189 
190 static int ncsi_cmd_handler_egmf(struct sk_buff *skb,
191 				 struct ncsi_cmd_arg *nca)
192 {
193 	struct ncsi_cmd_egmf_pkt *cmd;
194 
195 	cmd = skb_put_zero(skb, sizeof(*cmd));
196 	cmd->mode = htonl(nca->dwords[0]);
197 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
198 
199 	return 0;
200 }
201 
202 static int ncsi_cmd_handler_snfc(struct sk_buff *skb,
203 				 struct ncsi_cmd_arg *nca)
204 {
205 	struct ncsi_cmd_snfc_pkt *cmd;
206 
207 	cmd = skb_put_zero(skb, sizeof(*cmd));
208 	cmd->mode = nca->bytes[0];
209 	ncsi_cmd_build_header(&cmd->cmd.common, nca);
210 
211 	return 0;
212 }
213 
214 static struct ncsi_cmd_handler {
215 	unsigned char type;
216 	int           payload;
217 	int           (*handler)(struct sk_buff *skb,
218 				 struct ncsi_cmd_arg *nca);
219 } ncsi_cmd_handlers[] = {
220 	{ NCSI_PKT_CMD_CIS,    0, ncsi_cmd_handler_default },
221 	{ NCSI_PKT_CMD_SP,     4, ncsi_cmd_handler_sp      },
222 	{ NCSI_PKT_CMD_DP,     0, ncsi_cmd_handler_default },
223 	{ NCSI_PKT_CMD_EC,     0, ncsi_cmd_handler_default },
224 	{ NCSI_PKT_CMD_DC,     4, ncsi_cmd_handler_dc      },
225 	{ NCSI_PKT_CMD_RC,     4, ncsi_cmd_handler_rc      },
226 	{ NCSI_PKT_CMD_ECNT,   0, ncsi_cmd_handler_default },
227 	{ NCSI_PKT_CMD_DCNT,   0, ncsi_cmd_handler_default },
228 	{ NCSI_PKT_CMD_AE,     8, ncsi_cmd_handler_ae      },
229 	{ NCSI_PKT_CMD_SL,     8, ncsi_cmd_handler_sl      },
230 	{ NCSI_PKT_CMD_GLS,    0, ncsi_cmd_handler_default },
231 	{ NCSI_PKT_CMD_SVF,    8, ncsi_cmd_handler_svf     },
232 	{ NCSI_PKT_CMD_EV,     4, ncsi_cmd_handler_ev      },
233 	{ NCSI_PKT_CMD_DV,     0, ncsi_cmd_handler_default },
234 	{ NCSI_PKT_CMD_SMA,    8, ncsi_cmd_handler_sma     },
235 	{ NCSI_PKT_CMD_EBF,    4, ncsi_cmd_handler_ebf     },
236 	{ NCSI_PKT_CMD_DBF,    0, ncsi_cmd_handler_default },
237 	{ NCSI_PKT_CMD_EGMF,   4, ncsi_cmd_handler_egmf    },
238 	{ NCSI_PKT_CMD_DGMF,   0, ncsi_cmd_handler_default },
239 	{ NCSI_PKT_CMD_SNFC,   4, ncsi_cmd_handler_snfc    },
240 	{ NCSI_PKT_CMD_GVI,    0, ncsi_cmd_handler_default },
241 	{ NCSI_PKT_CMD_GC,     0, ncsi_cmd_handler_default },
242 	{ NCSI_PKT_CMD_GP,     0, ncsi_cmd_handler_default },
243 	{ NCSI_PKT_CMD_GCPS,   0, ncsi_cmd_handler_default },
244 	{ NCSI_PKT_CMD_GNS,    0, ncsi_cmd_handler_default },
245 	{ NCSI_PKT_CMD_GNPTS,  0, ncsi_cmd_handler_default },
246 	{ NCSI_PKT_CMD_GPS,    0, ncsi_cmd_handler_default },
247 	{ NCSI_PKT_CMD_OEM,    0, NULL                     },
248 	{ NCSI_PKT_CMD_PLDM,   0, NULL                     },
249 	{ NCSI_PKT_CMD_GPUUID, 0, ncsi_cmd_handler_default }
250 };
251 
252 static struct ncsi_request *ncsi_alloc_command(struct ncsi_cmd_arg *nca)
253 {
254 	struct ncsi_dev_priv *ndp = nca->ndp;
255 	struct ncsi_dev *nd = &ndp->ndev;
256 	struct net_device *dev = nd->dev;
257 	int hlen = LL_RESERVED_SPACE(dev);
258 	int tlen = dev->needed_tailroom;
259 	int len = hlen + tlen;
260 	struct sk_buff *skb;
261 	struct ncsi_request *nr;
262 
263 	nr = ncsi_alloc_request(ndp, nca->req_flags);
264 	if (!nr)
265 		return NULL;
266 
267 	/* NCSI command packet has 16-bytes header, payload, 4 bytes checksum.
268 	 * The packet needs padding if its payload is less than 26 bytes to
269 	 * meet 64 bytes minimal ethernet frame length.
270 	 */
271 	len += sizeof(struct ncsi_cmd_pkt_hdr) + 4;
272 	if (nca->payload < 26)
273 		len += 26;
274 	else
275 		len += nca->payload;
276 
277 	/* Allocate skb */
278 	skb = alloc_skb(len, GFP_ATOMIC);
279 	if (!skb) {
280 		ncsi_free_request(nr);
281 		return NULL;
282 	}
283 
284 	nr->cmd = skb;
285 	skb_reserve(skb, hlen);
286 	skb_reset_network_header(skb);
287 
288 	skb->dev = dev;
289 	skb->protocol = htons(ETH_P_NCSI);
290 
291 	return nr;
292 }
293 
294 int ncsi_xmit_cmd(struct ncsi_cmd_arg *nca)
295 {
296 	struct ncsi_request *nr;
297 	struct ethhdr *eh;
298 	struct ncsi_cmd_handler *nch = NULL;
299 	int i, ret;
300 
301 	/* Search for the handler */
302 	for (i = 0; i < ARRAY_SIZE(ncsi_cmd_handlers); i++) {
303 		if (ncsi_cmd_handlers[i].type == nca->type) {
304 			if (ncsi_cmd_handlers[i].handler)
305 				nch = &ncsi_cmd_handlers[i];
306 			else
307 				nch = NULL;
308 
309 			break;
310 		}
311 	}
312 
313 	if (!nch) {
314 		netdev_err(nca->ndp->ndev.dev,
315 			   "Cannot send packet with type 0x%02x\n", nca->type);
316 		return -ENOENT;
317 	}
318 
319 	/* Get packet payload length and allocate the request */
320 	nca->payload = nch->payload;
321 	nr = ncsi_alloc_command(nca);
322 	if (!nr)
323 		return -ENOMEM;
324 
325 	/* Prepare the packet */
326 	nca->id = nr->id;
327 	ret = nch->handler(nr->cmd, nca);
328 	if (ret) {
329 		ncsi_free_request(nr);
330 		return ret;
331 	}
332 
333 	/* Fill the ethernet header */
334 	eh = skb_push(nr->cmd, sizeof(*eh));
335 	eh->h_proto = htons(ETH_P_NCSI);
336 	eth_broadcast_addr(eh->h_dest);
337 	eth_broadcast_addr(eh->h_source);
338 
339 	/* Start the timer for the request that might not have
340 	 * corresponding response. Given NCSI is an internal
341 	 * connection a 1 second delay should be sufficient.
342 	 */
343 	nr->enabled = true;
344 	mod_timer(&nr->timer, jiffies + 1 * HZ);
345 
346 	/* Send NCSI packet */
347 	skb_get(nr->cmd);
348 	ret = dev_queue_xmit(nr->cmd);
349 	if (ret < 0) {
350 		ncsi_free_request(nr);
351 		return ret;
352 	}
353 
354 	return 0;
355 }
356