xref: /openbmc/linux/net/ncsi/ncsi-aen.c (revision 1c2dd16a)
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 	spin_lock_irqsave(&nc->lock, flags);
145 	ncm = &nc->modes[NCSI_MODE_LINK];
146 	hncdsc = (struct ncsi_aen_hncdsc_pkt *)h;
147 	ncm->data[3] = ntohl(hncdsc->status);
148 	if (!list_empty(&nc->link) ||
149 	    nc->state != NCSI_CHANNEL_ACTIVE) {
150 		spin_unlock_irqrestore(&nc->lock, flags);
151 		return 0;
152 	}
153 
154 	spin_unlock_irqrestore(&nc->lock, flags);
155 	if (!(ndp->flags & NCSI_DEV_HWA) && !(ncm->data[3] & 0x1))
156 		ndp->flags |= NCSI_DEV_RESHUFFLE;
157 
158 	/* If this channel is the active one and the link doesn't
159 	 * work, we have to choose another channel to be active one.
160 	 * The logic here is exactly similar to what we do when link
161 	 * is down on the active channel.
162 	 *
163 	 * On the other hand, we need configure it when host driver
164 	 * state on the active channel becomes ready.
165 	 */
166 	ncsi_stop_channel_monitor(nc);
167 
168 	spin_lock_irqsave(&nc->lock, flags);
169 	nc->state = (ncm->data[3] & 0x1) ? NCSI_CHANNEL_INACTIVE :
170 					   NCSI_CHANNEL_ACTIVE;
171 	spin_unlock_irqrestore(&nc->lock, flags);
172 
173 	spin_lock_irqsave(&ndp->lock, flags);
174 	list_add_tail_rcu(&nc->link, &ndp->channel_queue);
175 	spin_unlock_irqrestore(&ndp->lock, flags);
176 
177 	ncsi_process_next_channel(ndp);
178 
179 	return 0;
180 }
181 
182 static struct ncsi_aen_handler {
183 	unsigned char type;
184 	int           payload;
185 	int           (*handler)(struct ncsi_dev_priv *ndp,
186 				 struct ncsi_aen_pkt_hdr *h);
187 } ncsi_aen_handlers[] = {
188 	{ NCSI_PKT_AEN_LSC,    12, ncsi_aen_handler_lsc    },
189 	{ NCSI_PKT_AEN_CR,      4, ncsi_aen_handler_cr     },
190 	{ NCSI_PKT_AEN_HNCDSC,  4, ncsi_aen_handler_hncdsc }
191 };
192 
193 int ncsi_aen_handler(struct ncsi_dev_priv *ndp, struct sk_buff *skb)
194 {
195 	struct ncsi_aen_pkt_hdr *h;
196 	struct ncsi_aen_handler *nah = NULL;
197 	int i, ret;
198 
199 	/* Find the handler */
200 	h = (struct ncsi_aen_pkt_hdr *)skb_network_header(skb);
201 	for (i = 0; i < ARRAY_SIZE(ncsi_aen_handlers); i++) {
202 		if (ncsi_aen_handlers[i].type == h->type) {
203 			nah = &ncsi_aen_handlers[i];
204 			break;
205 		}
206 	}
207 
208 	if (!nah) {
209 		netdev_warn(ndp->ndev.dev, "Invalid AEN (0x%x) received\n",
210 			    h->type);
211 		return -ENOENT;
212 	}
213 
214 	ret = ncsi_validate_aen_pkt(h, nah->payload);
215 	if (ret)
216 		goto out;
217 
218 	ret = nah->handler(ndp, h);
219 out:
220 	consume_skb(skb);
221 	return ret;
222 }
223