xref: /linux/net/ncsi/ncsi-aen.c (revision fd639726bf15fca8ee1a00dce8e0096d0ad9bd18)
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 	netdev_info(ndp->ndev.dev, "NCSI: LSC AEN - channel %u state %s\n",
77 		    nc->id, data & 0x1 ? "up" : "down");
78 
79 	chained = !list_empty(&nc->link);
80 	state = nc->state;
81 	spin_unlock_irqrestore(&nc->lock, flags);
82 
83 	if (!((old_data ^ data) & 0x1) || chained)
84 		return 0;
85 	if (!(state == NCSI_CHANNEL_INACTIVE && (data & 0x1)) &&
86 	    !(state == NCSI_CHANNEL_ACTIVE && !(data & 0x1)))
87 		return 0;
88 
89 	if (!(ndp->flags & NCSI_DEV_HWA) &&
90 	    state == NCSI_CHANNEL_ACTIVE)
91 		ndp->flags |= NCSI_DEV_RESHUFFLE;
92 
93 	ncsi_stop_channel_monitor(nc);
94 	spin_lock_irqsave(&ndp->lock, flags);
95 	list_add_tail_rcu(&nc->link, &ndp->channel_queue);
96 	spin_unlock_irqrestore(&ndp->lock, flags);
97 
98 	return ncsi_process_next_channel(ndp);
99 }
100 
101 static int ncsi_aen_handler_cr(struct ncsi_dev_priv *ndp,
102 			       struct ncsi_aen_pkt_hdr *h)
103 {
104 	struct ncsi_channel *nc;
105 	unsigned long flags;
106 
107 	/* Find the NCSI channel */
108 	ncsi_find_package_and_channel(ndp, h->common.channel, NULL, &nc);
109 	if (!nc)
110 		return -ENODEV;
111 
112 	spin_lock_irqsave(&nc->lock, flags);
113 	if (!list_empty(&nc->link) ||
114 	    nc->state != NCSI_CHANNEL_ACTIVE) {
115 		spin_unlock_irqrestore(&nc->lock, flags);
116 		return 0;
117 	}
118 	spin_unlock_irqrestore(&nc->lock, flags);
119 
120 	ncsi_stop_channel_monitor(nc);
121 	spin_lock_irqsave(&nc->lock, flags);
122 	nc->state = NCSI_CHANNEL_INVISIBLE;
123 	spin_unlock_irqrestore(&nc->lock, flags);
124 
125 	spin_lock_irqsave(&ndp->lock, flags);
126 	nc->state = NCSI_CHANNEL_INACTIVE;
127 	list_add_tail_rcu(&nc->link, &ndp->channel_queue);
128 	spin_unlock_irqrestore(&ndp->lock, flags);
129 
130 	return ncsi_process_next_channel(ndp);
131 }
132 
133 static int ncsi_aen_handler_hncdsc(struct ncsi_dev_priv *ndp,
134 				   struct ncsi_aen_pkt_hdr *h)
135 {
136 	struct ncsi_channel *nc;
137 	struct ncsi_channel_mode *ncm;
138 	struct ncsi_aen_hncdsc_pkt *hncdsc;
139 	unsigned long flags;
140 
141 	/* Find the NCSI channel */
142 	ncsi_find_package_and_channel(ndp, h->common.channel, NULL, &nc);
143 	if (!nc)
144 		return -ENODEV;
145 
146 	/* If the channel is active one, we need reconfigure it */
147 	spin_lock_irqsave(&nc->lock, flags);
148 	ncm = &nc->modes[NCSI_MODE_LINK];
149 	hncdsc = (struct ncsi_aen_hncdsc_pkt *)h;
150 	ncm->data[3] = ntohl(hncdsc->status);
151 	netdev_info(ndp->ndev.dev, "NCSI: HNCDSC AEN - channel %u state %s\n",
152 		    nc->id, ncm->data[3] & 0x3 ? "up" : "down");
153 	if (!list_empty(&nc->link) ||
154 	    nc->state != NCSI_CHANNEL_ACTIVE) {
155 		spin_unlock_irqrestore(&nc->lock, flags);
156 		return 0;
157 	}
158 
159 	spin_unlock_irqrestore(&nc->lock, flags);
160 	if (!(ndp->flags & NCSI_DEV_HWA) && !(ncm->data[3] & 0x1))
161 		ndp->flags |= NCSI_DEV_RESHUFFLE;
162 
163 	/* If this channel is the active one and the link doesn't
164 	 * work, we have to choose another channel to be active one.
165 	 * The logic here is exactly similar to what we do when link
166 	 * is down on the active channel.
167 	 *
168 	 * On the other hand, we need configure it when host driver
169 	 * state on the active channel becomes ready.
170 	 */
171 	ncsi_stop_channel_monitor(nc);
172 
173 	spin_lock_irqsave(&nc->lock, flags);
174 	nc->state = (ncm->data[3] & 0x1) ? NCSI_CHANNEL_INACTIVE :
175 					   NCSI_CHANNEL_ACTIVE;
176 	spin_unlock_irqrestore(&nc->lock, flags);
177 
178 	spin_lock_irqsave(&ndp->lock, flags);
179 	list_add_tail_rcu(&nc->link, &ndp->channel_queue);
180 	spin_unlock_irqrestore(&ndp->lock, flags);
181 
182 	ncsi_process_next_channel(ndp);
183 
184 	return 0;
185 }
186 
187 static struct ncsi_aen_handler {
188 	unsigned char type;
189 	int           payload;
190 	int           (*handler)(struct ncsi_dev_priv *ndp,
191 				 struct ncsi_aen_pkt_hdr *h);
192 } ncsi_aen_handlers[] = {
193 	{ NCSI_PKT_AEN_LSC,    12, ncsi_aen_handler_lsc    },
194 	{ NCSI_PKT_AEN_CR,      4, ncsi_aen_handler_cr     },
195 	{ NCSI_PKT_AEN_HNCDSC,  8, ncsi_aen_handler_hncdsc }
196 };
197 
198 int ncsi_aen_handler(struct ncsi_dev_priv *ndp, struct sk_buff *skb)
199 {
200 	struct ncsi_aen_pkt_hdr *h;
201 	struct ncsi_aen_handler *nah = NULL;
202 	int i, ret;
203 
204 	/* Find the handler */
205 	h = (struct ncsi_aen_pkt_hdr *)skb_network_header(skb);
206 	for (i = 0; i < ARRAY_SIZE(ncsi_aen_handlers); i++) {
207 		if (ncsi_aen_handlers[i].type == h->type) {
208 			nah = &ncsi_aen_handlers[i];
209 			break;
210 		}
211 	}
212 
213 	if (!nah) {
214 		netdev_warn(ndp->ndev.dev, "Invalid AEN (0x%x) received\n",
215 			    h->type);
216 		return -ENOENT;
217 	}
218 
219 	ret = ncsi_validate_aen_pkt(h, nah->payload);
220 	if (ret) {
221 		netdev_warn(ndp->ndev.dev,
222 			    "NCSI: 'bad' packet ignored for AEN type 0x%x\n",
223 			    h->type);
224 		goto out;
225 	}
226 
227 	ret = nah->handler(ndp, h);
228 	if (ret)
229 		netdev_err(ndp->ndev.dev,
230 			   "NCSI: Handler for AEN type 0x%x returned %d\n",
231 			   h->type, ret);
232 out:
233 	consume_skb(skb);
234 	return ret;
235 }
236