1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright Gavin Shan, IBM Corporation 2016.
4 */
5
6 #include <linux/module.h>
7 #include <linux/kernel.h>
8 #include <linux/init.h>
9 #include <linux/netdevice.h>
10 #include <linux/skbuff.h>
11
12 #include <net/ncsi.h>
13 #include <net/net_namespace.h>
14 #include <net/sock.h>
15
16 #include "internal.h"
17 #include "ncsi-pkt.h"
18
19 static int ncsi_validate_aen_pkt(struct ncsi_aen_pkt_hdr *h,
20 const unsigned short payload)
21 {
22 u32 checksum;
23 __be32 *pchecksum;
24
25 if (h->common.revision != NCSI_PKT_REVISION)
26 return -EINVAL;
27 if (ntohs(h->common.length) != payload)
28 return -EINVAL;
29
30 /* Validate checksum, which might be zeroes if the
31 * sender doesn't support checksum according to NCSI
32 * specification.
33 */
34 pchecksum = (__be32 *)((void *)(h + 1) + payload - 4);
35 if (ntohl(*pchecksum) == 0)
36 return 0;
37
38 checksum = ncsi_calculate_checksum((unsigned char *)h,
39 sizeof(*h) + payload - 4);
40 if (*pchecksum != htonl(checksum))
41 return -EINVAL;
42
43 return 0;
44 }
45
46 static int ncsi_aen_handler_lsc(struct ncsi_dev_priv *ndp,
47 struct ncsi_aen_pkt_hdr *h)
48 {
49 struct ncsi_channel *nc, *tmp;
50 struct ncsi_channel_mode *ncm;
51 unsigned long old_data, data;
52 struct ncsi_aen_lsc_pkt *lsc;
53 struct ncsi_package *np;
54 bool had_link, has_link;
55 unsigned long flags;
56 bool chained;
57 int state;
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 lsc = (struct ncsi_aen_lsc_pkt *)h;
66
67 spin_lock_irqsave(&nc->lock, flags);
68 ncm = &nc->modes[NCSI_MODE_LINK];
69 old_data = ncm->data[2];
70 data = ntohl(lsc->status);
71 ncm->data[2] = data;
72 ncm->data[4] = ntohl(lsc->oem_status);
73
74 had_link = !!(old_data & 0x1);
75 has_link = !!(data & 0x1);
76
77 netdev_dbg(ndp->ndev.dev, "NCSI: LSC AEN - channel %u state %s\n",
78 nc->id, data & 0x1 ? "up" : "down");
79
80 chained = !list_empty(&nc->link);
81 state = nc->state;
82 spin_unlock_irqrestore(&nc->lock, flags);
83
84 if (state == NCSI_CHANNEL_INACTIVE)
85 netdev_warn(ndp->ndev.dev,
86 "NCSI: Inactive channel %u received AEN!\n",
87 nc->id);
88
89 if ((had_link == has_link) || chained)
90 return 0;
91
92 if (!ndp->multi_package && !nc->package->multi_channel) {
93 if (had_link) {
94 ndp->flags |= NCSI_DEV_RESHUFFLE;
95 ncsi_stop_channel_monitor(nc);
96 spin_lock_irqsave(&ndp->lock, flags);
97 list_add_tail_rcu(&nc->link, &ndp->channel_queue);
98 spin_unlock_irqrestore(&ndp->lock, flags);
99 return ncsi_process_next_channel(ndp);
100 }
101 /* Configured channel came up */
102 return 0;
103 }
104
105 if (had_link) {
106 ncm = &nc->modes[NCSI_MODE_TX_ENABLE];
107 if (ncsi_channel_is_last(ndp, nc)) {
108 /* No channels left, reconfigure */
109 return ncsi_reset_dev(&ndp->ndev);
110 } else if (ncm->enable) {
111 /* Need to failover Tx channel */
112 ncsi_update_tx_channel(ndp, nc->package, nc, NULL);
113 }
114 } else if (has_link && nc->package->preferred_channel == nc) {
115 /* Return Tx to preferred channel */
116 ncsi_update_tx_channel(ndp, nc->package, NULL, nc);
117 } else if (has_link) {
118 NCSI_FOR_EACH_PACKAGE(ndp, np) {
119 NCSI_FOR_EACH_CHANNEL(np, tmp) {
120 /* Enable Tx on this channel if the current Tx
121 * channel is down.
122 */
123 ncm = &tmp->modes[NCSI_MODE_TX_ENABLE];
124 if (ncm->enable &&
125 !ncsi_channel_has_link(tmp)) {
126 ncsi_update_tx_channel(ndp, nc->package,
127 tmp, nc);
128 break;
129 }
130 }
131 }
132 }
133
134 /* Leave configured channels active in a multi-channel scenario so
135 * AEN events are still received.
136 */
137 return 0;
138 }
139
140 static int ncsi_aen_handler_cr(struct ncsi_dev_priv *ndp,
141 struct ncsi_aen_pkt_hdr *h)
142 {
143 struct ncsi_channel *nc;
144 unsigned long flags;
145
146 /* Find the NCSI channel */
147 ncsi_find_package_and_channel(ndp, h->common.channel, NULL, &nc);
148 if (!nc)
149 return -ENODEV;
150
151 spin_lock_irqsave(&nc->lock, flags);
152 if (!list_empty(&nc->link) ||
153 nc->state != NCSI_CHANNEL_ACTIVE) {
154 spin_unlock_irqrestore(&nc->lock, flags);
155 return 0;
156 }
157 spin_unlock_irqrestore(&nc->lock, flags);
158
159 ncsi_stop_channel_monitor(nc);
160 spin_lock_irqsave(&nc->lock, flags);
161 nc->state = NCSI_CHANNEL_INVISIBLE;
162 spin_unlock_irqrestore(&nc->lock, flags);
163
164 spin_lock_irqsave(&ndp->lock, flags);
165 nc->state = NCSI_CHANNEL_INACTIVE;
166 list_add_tail_rcu(&nc->link, &ndp->channel_queue);
167 spin_unlock_irqrestore(&ndp->lock, flags);
168 nc->modes[NCSI_MODE_TX_ENABLE].enable = 0;
169
170 return ncsi_process_next_channel(ndp);
171 }
172
173 static int ncsi_aen_handler_hncdsc(struct ncsi_dev_priv *ndp,
174 struct ncsi_aen_pkt_hdr *h)
175 {
176 struct ncsi_channel *nc;
177 struct ncsi_channel_mode *ncm;
178 struct ncsi_aen_hncdsc_pkt *hncdsc;
179 unsigned long flags;
180
181 /* Find the NCSI channel */
182 ncsi_find_package_and_channel(ndp, h->common.channel, NULL, &nc);
183 if (!nc)
184 return -ENODEV;
185
186 spin_lock_irqsave(&nc->lock, flags);
187 ncm = &nc->modes[NCSI_MODE_LINK];
188 hncdsc = (struct ncsi_aen_hncdsc_pkt *)h;
189 ncm->data[3] = ntohl(hncdsc->status);
190 spin_unlock_irqrestore(&nc->lock, flags);
191 netdev_dbg(ndp->ndev.dev,
192 "NCSI: host driver %srunning on channel %u\n",
193 ncm->data[3] & 0x1 ? "" : "not ", nc->id);
194
195 return 0;
196 }
197
198 static struct ncsi_aen_handler {
199 unsigned char type;
200 int payload;
201 int (*handler)(struct ncsi_dev_priv *ndp,
202 struct ncsi_aen_pkt_hdr *h);
203 } ncsi_aen_handlers[] = {
204 { NCSI_PKT_AEN_LSC, 12, ncsi_aen_handler_lsc },
205 { NCSI_PKT_AEN_CR, 4, ncsi_aen_handler_cr },
206 { NCSI_PKT_AEN_HNCDSC, 8, ncsi_aen_handler_hncdsc }
207 };
208
209 int ncsi_aen_handler(struct ncsi_dev_priv *ndp, struct sk_buff *skb)
210 {
211 struct ncsi_aen_pkt_hdr *h;
212 struct ncsi_aen_handler *nah = NULL;
213 int i, ret;
214
215 /* Find the handler */
216 h = (struct ncsi_aen_pkt_hdr *)skb_network_header(skb);
217 for (i = 0; i < ARRAY_SIZE(ncsi_aen_handlers); i++) {
218 if (ncsi_aen_handlers[i].type == h->type) {
219 nah = &ncsi_aen_handlers[i];
220 break;
221 }
222 }
223
224 if (!nah) {
225 netdev_warn(ndp->ndev.dev, "Invalid AEN (0x%x) received\n",
226 h->type);
227 return -ENOENT;
228 }
229
230 ret = ncsi_validate_aen_pkt(h, nah->payload);
231 if (ret) {
232 netdev_warn(ndp->ndev.dev,
233 "NCSI: 'bad' packet ignored for AEN type 0x%x\n",
234 h->type);
235 goto out;
236 }
237
238 ret = nah->handler(ndp, h);
239 if (ret)
240 netdev_err(ndp->ndev.dev,
241 "NCSI: Handler for AEN type 0x%x returned %d\n",
242 h->type, ret);
243 out:
244 consume_skb(skb);
245 return ret;
246 }
247
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.