xref: /openbmc/linux/net/ncsi/ncsi-aen.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/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 	unsigned long old_data;
57 	unsigned long flags;
58 
59 	/* Find the NCSI channel */
60 	ncsi_find_package_and_channel(ndp, h->common.channel, NULL, &nc);
61 	if (!nc)
62 		return -ENODEV;
63 
64 	/* Update the link status */
65 	ncm = &nc->modes[NCSI_MODE_LINK];
66 	lsc = (struct ncsi_aen_lsc_pkt *)h;
67 	old_data = ncm->data[2];
68 	ncm->data[2] = ntohl(lsc->status);
69 	ncm->data[4] = ntohl(lsc->oem_status);
70 	if (!((old_data ^ ncm->data[2]) & 0x1) ||
71 	    !list_empty(&nc->link))
72 		return 0;
73 	if (!(nc->state == NCSI_CHANNEL_INACTIVE && (ncm->data[2] & 0x1)) &&
74 	    !(nc->state == NCSI_CHANNEL_ACTIVE && !(ncm->data[2] & 0x1)))
75 		return 0;
76 
77 	if (!(ndp->flags & NCSI_DEV_HWA) &&
78 	    nc->state == NCSI_CHANNEL_ACTIVE)
79 		ndp->flags |= NCSI_DEV_RESHUFFLE;
80 
81 	ncsi_stop_channel_monitor(nc);
82 	spin_lock_irqsave(&ndp->lock, flags);
83 	list_add_tail_rcu(&nc->link, &ndp->channel_queue);
84 	spin_unlock_irqrestore(&ndp->lock, flags);
85 
86 	return ncsi_process_next_channel(ndp);
87 }
88 
89 static int ncsi_aen_handler_cr(struct ncsi_dev_priv *ndp,
90 			       struct ncsi_aen_pkt_hdr *h)
91 {
92 	struct ncsi_channel *nc;
93 	unsigned long flags;
94 
95 	/* Find the NCSI channel */
96 	ncsi_find_package_and_channel(ndp, h->common.channel, NULL, &nc);
97 	if (!nc)
98 		return -ENODEV;
99 
100 	if (!list_empty(&nc->link) ||
101 	    nc->state != NCSI_CHANNEL_ACTIVE)
102 		return 0;
103 
104 	ncsi_stop_channel_monitor(nc);
105 	spin_lock_irqsave(&ndp->lock, flags);
106 	xchg(&nc->state, NCSI_CHANNEL_INACTIVE);
107 	list_add_tail_rcu(&nc->link, &ndp->channel_queue);
108 	spin_unlock_irqrestore(&ndp->lock, flags);
109 
110 	return ncsi_process_next_channel(ndp);
111 }
112 
113 static int ncsi_aen_handler_hncdsc(struct ncsi_dev_priv *ndp,
114 				   struct ncsi_aen_pkt_hdr *h)
115 {
116 	struct ncsi_channel *nc;
117 	struct ncsi_channel_mode *ncm;
118 	struct ncsi_aen_hncdsc_pkt *hncdsc;
119 	unsigned long flags;
120 
121 	/* Find the NCSI channel */
122 	ncsi_find_package_and_channel(ndp, h->common.channel, NULL, &nc);
123 	if (!nc)
124 		return -ENODEV;
125 
126 	/* If the channel is active one, we need reconfigure it */
127 	ncm = &nc->modes[NCSI_MODE_LINK];
128 	hncdsc = (struct ncsi_aen_hncdsc_pkt *)h;
129 	ncm->data[3] = ntohl(hncdsc->status);
130 	if (!list_empty(&nc->link) ||
131 	    nc->state != NCSI_CHANNEL_ACTIVE ||
132 	    (ncm->data[3] & 0x1))
133 		return 0;
134 
135 	if (ndp->flags & NCSI_DEV_HWA)
136 		ndp->flags |= NCSI_DEV_RESHUFFLE;
137 
138 	/* If this channel is the active one and the link doesn't
139 	 * work, we have to choose another channel to be active one.
140 	 * The logic here is exactly similar to what we do when link
141 	 * is down on the active channel.
142 	 */
143 	ncsi_stop_channel_monitor(nc);
144 	spin_lock_irqsave(&ndp->lock, flags);
145 	list_add_tail_rcu(&nc->link, &ndp->channel_queue);
146 	spin_unlock_irqrestore(&ndp->lock, flags);
147 
148 	ncsi_process_next_channel(ndp);
149 
150 	return 0;
151 }
152 
153 static struct ncsi_aen_handler {
154 	unsigned char type;
155 	int           payload;
156 	int           (*handler)(struct ncsi_dev_priv *ndp,
157 				 struct ncsi_aen_pkt_hdr *h);
158 } ncsi_aen_handlers[] = {
159 	{ NCSI_PKT_AEN_LSC,    12, ncsi_aen_handler_lsc    },
160 	{ NCSI_PKT_AEN_CR,      4, ncsi_aen_handler_cr     },
161 	{ NCSI_PKT_AEN_HNCDSC,  4, ncsi_aen_handler_hncdsc }
162 };
163 
164 int ncsi_aen_handler(struct ncsi_dev_priv *ndp, struct sk_buff *skb)
165 {
166 	struct ncsi_aen_pkt_hdr *h;
167 	struct ncsi_aen_handler *nah = NULL;
168 	int i, ret;
169 
170 	/* Find the handler */
171 	h = (struct ncsi_aen_pkt_hdr *)skb_network_header(skb);
172 	for (i = 0; i < ARRAY_SIZE(ncsi_aen_handlers); i++) {
173 		if (ncsi_aen_handlers[i].type == h->type) {
174 			nah = &ncsi_aen_handlers[i];
175 			break;
176 		}
177 	}
178 
179 	if (!nah) {
180 		netdev_warn(ndp->ndev.dev, "Invalid AEN (0x%x) received\n",
181 			    h->type);
182 		return -ENOENT;
183 	}
184 
185 	ret = ncsi_validate_aen_pkt(h, nah->payload);
186 	if (ret)
187 		goto out;
188 
189 	ret = nah->handler(ndp, h);
190 out:
191 	consume_skb(skb);
192 	return ret;
193 }
194