xref: /openbmc/linux/net/ncsi/ncsi-aen.c (revision 93032e31)
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/netdevice.h>
14 #include <linux/skbuff.h>
15 
16 #include <net/ncsi.h>
17 #include <net/net_namespace.h>
18 #include <net/sock.h>
19 
20 #include "internal.h"
21 #include "ncsi-pkt.h"
22 
23 static int ncsi_validate_aen_pkt(struct ncsi_aen_pkt_hdr *h,
24 				 const unsigned short payload)
25 {
26 	u32 checksum;
27 	__be32 *pchecksum;
28 
29 	if (h->common.revision != NCSI_PKT_REVISION)
30 		return -EINVAL;
31 	if (ntohs(h->common.length) != payload)
32 		return -EINVAL;
33 
34 	/* Validate checksum, which might be zeroes if the
35 	 * sender doesn't support checksum according to NCSI
36 	 * specification.
37 	 */
38 	pchecksum = (__be32 *)((void *)(h + 1) + payload - 4);
39 	if (ntohl(*pchecksum) == 0)
40 		return 0;
41 
42 	checksum = ncsi_calculate_checksum((unsigned char *)h,
43 					   sizeof(*h) + payload - 4);
44 	if (*pchecksum != htonl(checksum))
45 		return -EINVAL;
46 
47 	return 0;
48 }
49 
50 static int ncsi_aen_handler_lsc(struct ncsi_dev_priv *ndp,
51 				struct ncsi_aen_pkt_hdr *h)
52 {
53 	struct ncsi_aen_lsc_pkt *lsc;
54 	struct ncsi_channel *nc;
55 	struct ncsi_channel_mode *ncm;
56 	bool chained;
57 	int state;
58 	unsigned long old_data, data;
59 	unsigned long flags;
60 
61 	/* Find the NCSI channel */
62 	ncsi_find_package_and_channel(ndp, h->common.channel, NULL, &nc);
63 	if (!nc)
64 		return -ENODEV;
65 
66 	/* Update the link status */
67 	lsc = (struct ncsi_aen_lsc_pkt *)h;
68 
69 	spin_lock_irqsave(&nc->lock, flags);
70 	ncm = &nc->modes[NCSI_MODE_LINK];
71 	old_data = ncm->data[2];
72 	data = ntohl(lsc->status);
73 	ncm->data[2] = data;
74 	ncm->data[4] = ntohl(lsc->oem_status);
75 
76 	chained = !list_empty(&nc->link);
77 	state = nc->state;
78 	spin_unlock_irqrestore(&nc->lock, flags);
79 
80 	if (!((old_data ^ data) & 0x1) || chained)
81 		return 0;
82 	if (!(state == NCSI_CHANNEL_INACTIVE && (data & 0x1)) &&
83 	    !(state == NCSI_CHANNEL_ACTIVE && !(data & 0x1)))
84 		return 0;
85 
86 	if (!(ndp->flags & NCSI_DEV_HWA) &&
87 	    state == NCSI_CHANNEL_ACTIVE)
88 		ndp->flags |= NCSI_DEV_RESHUFFLE;
89 
90 	ncsi_stop_channel_monitor(nc);
91 	spin_lock_irqsave(&ndp->lock, flags);
92 	list_add_tail_rcu(&nc->link, &ndp->channel_queue);
93 	spin_unlock_irqrestore(&ndp->lock, flags);
94 
95 	return ncsi_process_next_channel(ndp);
96 }
97 
98 static int ncsi_aen_handler_cr(struct ncsi_dev_priv *ndp,
99 			       struct ncsi_aen_pkt_hdr *h)
100 {
101 	struct ncsi_channel *nc;
102 	unsigned long flags;
103 
104 	/* Find the NCSI channel */
105 	ncsi_find_package_and_channel(ndp, h->common.channel, NULL, &nc);
106 	if (!nc)
107 		return -ENODEV;
108 
109 	spin_lock_irqsave(&nc->lock, flags);
110 	if (!list_empty(&nc->link) ||
111 	    nc->state != NCSI_CHANNEL_ACTIVE) {
112 		spin_unlock_irqrestore(&nc->lock, flags);
113 		return 0;
114 	}
115 	spin_unlock_irqrestore(&nc->lock, flags);
116 
117 	ncsi_stop_channel_monitor(nc);
118 	spin_lock_irqsave(&nc->lock, flags);
119 	nc->state = NCSI_CHANNEL_INVISIBLE;
120 	spin_unlock_irqrestore(&nc->lock, flags);
121 
122 	spin_lock_irqsave(&ndp->lock, flags);
123 	nc->state = NCSI_CHANNEL_INACTIVE;
124 	list_add_tail_rcu(&nc->link, &ndp->channel_queue);
125 	spin_unlock_irqrestore(&ndp->lock, flags);
126 
127 	return ncsi_process_next_channel(ndp);
128 }
129 
130 static int ncsi_aen_handler_hncdsc(struct ncsi_dev_priv *ndp,
131 				   struct ncsi_aen_pkt_hdr *h)
132 {
133 	struct ncsi_channel *nc;
134 	struct ncsi_channel_mode *ncm;
135 	struct ncsi_aen_hncdsc_pkt *hncdsc;
136 	unsigned long flags;
137 
138 	/* Find the NCSI channel */
139 	ncsi_find_package_and_channel(ndp, h->common.channel, NULL, &nc);
140 	if (!nc)
141 		return -ENODEV;
142 
143 	/* If the channel is active one, we need reconfigure it */
144 	ncm = &nc->modes[NCSI_MODE_LINK];
145 	hncdsc = (struct ncsi_aen_hncdsc_pkt *)h;
146 	ncm->data[3] = ntohl(hncdsc->status);
147 	if (!list_empty(&nc->link) ||
148 	    nc->state != NCSI_CHANNEL_ACTIVE ||
149 	    (ncm->data[3] & 0x1))
150 		return 0;
151 
152 	if (ndp->flags & NCSI_DEV_HWA)
153 		ndp->flags |= NCSI_DEV_RESHUFFLE;
154 
155 	/* If this channel is the active one and the link doesn't
156 	 * work, we have to choose another channel to be active one.
157 	 * The logic here is exactly similar to what we do when link
158 	 * is down on the active channel.
159 	 */
160 	ncsi_stop_channel_monitor(nc);
161 	spin_lock_irqsave(&ndp->lock, flags);
162 	list_add_tail_rcu(&nc->link, &ndp->channel_queue);
163 	spin_unlock_irqrestore(&ndp->lock, flags);
164 
165 	ncsi_process_next_channel(ndp);
166 
167 	return 0;
168 }
169 
170 static struct ncsi_aen_handler {
171 	unsigned char type;
172 	int           payload;
173 	int           (*handler)(struct ncsi_dev_priv *ndp,
174 				 struct ncsi_aen_pkt_hdr *h);
175 } ncsi_aen_handlers[] = {
176 	{ NCSI_PKT_AEN_LSC,    12, ncsi_aen_handler_lsc    },
177 	{ NCSI_PKT_AEN_CR,      4, ncsi_aen_handler_cr     },
178 	{ NCSI_PKT_AEN_HNCDSC,  4, ncsi_aen_handler_hncdsc }
179 };
180 
181 int ncsi_aen_handler(struct ncsi_dev_priv *ndp, struct sk_buff *skb)
182 {
183 	struct ncsi_aen_pkt_hdr *h;
184 	struct ncsi_aen_handler *nah = NULL;
185 	int i, ret;
186 
187 	/* Find the handler */
188 	h = (struct ncsi_aen_pkt_hdr *)skb_network_header(skb);
189 	for (i = 0; i < ARRAY_SIZE(ncsi_aen_handlers); i++) {
190 		if (ncsi_aen_handlers[i].type == h->type) {
191 			nah = &ncsi_aen_handlers[i];
192 			break;
193 		}
194 	}
195 
196 	if (!nah) {
197 		netdev_warn(ndp->ndev.dev, "Invalid AEN (0x%x) received\n",
198 			    h->type);
199 		return -ENOENT;
200 	}
201 
202 	ret = ncsi_validate_aen_pkt(h, nah->payload);
203 	if (ret)
204 		goto out;
205 
206 	ret = nah->handler(ndp, h);
207 out:
208 	consume_skb(skb);
209 	return ret;
210 }
211