tipc: eliminate redundant code with kfree_skb_list routine
[linux-2.6-block.git] / net / tipc / ib_media.c
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1/*
2 * net/tipc/ib_media.c: Infiniband bearer support for TIPC
3 *
4 * Copyright (c) 2013 Patrick McHardy <kaber@trash.net>
5 *
6 * Based on eth_media.c, which carries the following copyright notice:
7 *
8 * Copyright (c) 2001-2007, Ericsson AB
9 * Copyright (c) 2005-2008, 2011, Wind River Systems
10 * All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions are met:
14 *
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the names of the copyright holders nor the names of its
21 * contributors may be used to endorse or promote products derived from
22 * this software without specific prior written permission.
23 *
24 * Alternatively, this software may be distributed under the terms of the
25 * GNU General Public License ("GPL") version 2 as published by the Free
26 * Software Foundation.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
29 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
32 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
33 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
34 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
35 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
36 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
37 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
38 * POSSIBILITY OF SUCH DAMAGE.
39 */
40
41#include <linux/if_infiniband.h>
42#include "core.h"
43#include "bearer.h"
44
4babbaa8 45#define MAX_IB_MEDIA MAX_BEARERS
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46
47/**
4babbaa8 48 * struct ib_media - Infiniband media data structure
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49 * @bearer: ptr to associated "generic" bearer structure
50 * @dev: ptr to associated Infiniband network device
51 * @tipc_packet_type: used in binding TIPC to Infiniband driver
52 * @cleanup: work item used when disabling bearer
53 */
54
4babbaa8 55struct ib_media {
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56 struct tipc_bearer *bearer;
57 struct net_device *dev;
58 struct packet_type tipc_packet_type;
59 struct work_struct setup;
60 struct work_struct cleanup;
61};
62
63static struct tipc_media ib_media_info;
4babbaa8 64static struct ib_media ib_media_array[MAX_IB_MEDIA];
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65static int ib_started;
66
67/**
68 * ib_media_addr_set - initialize Infiniband media address structure
69 *
70 * Media-dependent "value" field stores MAC address in first 6 bytes
71 * and zeroes out the remaining bytes.
72 */
73static void ib_media_addr_set(const struct tipc_bearer *tb_ptr,
74 struct tipc_media_addr *a, char *mac)
75{
76 BUILD_BUG_ON(sizeof(a->value) < INFINIBAND_ALEN);
77 memcpy(a->value, mac, INFINIBAND_ALEN);
78 a->media_id = TIPC_MEDIA_TYPE_IB;
79 a->broadcast = !memcmp(mac, tb_ptr->bcast_addr.value, INFINIBAND_ALEN);
80}
81
82/**
83 * send_msg - send a TIPC message out over an InfiniBand interface
84 */
85static int send_msg(struct sk_buff *buf, struct tipc_bearer *tb_ptr,
86 struct tipc_media_addr *dest)
87{
88 struct sk_buff *clone;
89 struct net_device *dev;
90 int delta;
91
92 clone = skb_clone(buf, GFP_ATOMIC);
93 if (!clone)
94 return 0;
95
4babbaa8 96 dev = ((struct ib_media *)(tb_ptr->usr_handle))->dev;
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97 delta = dev->hard_header_len - skb_headroom(buf);
98
99 if ((delta > 0) &&
100 pskb_expand_head(clone, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) {
101 kfree_skb(clone);
102 return 0;
103 }
104
105 skb_reset_network_header(clone);
106 clone->dev = dev;
107 clone->protocol = htons(ETH_P_TIPC);
108 dev_hard_header(clone, dev, ETH_P_TIPC, dest->value,
109 dev->dev_addr, clone->len);
110 dev_queue_xmit(clone);
111 return 0;
112}
113
114/**
115 * recv_msg - handle incoming TIPC message from an InfiniBand interface
116 *
117 * Accept only packets explicitly sent to this node, or broadcast packets;
118 * ignores packets sent using InfiniBand multicast, and traffic sent to other
119 * nodes (which can happen if interface is running in promiscuous mode).
120 */
121static int recv_msg(struct sk_buff *buf, struct net_device *dev,
122 struct packet_type *pt, struct net_device *orig_dev)
123{
4babbaa8 124 struct ib_media *ib_ptr = (struct ib_media *)pt->af_packet_priv;
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125
126 if (!net_eq(dev_net(dev), &init_net)) {
127 kfree_skb(buf);
67981583 128 return NET_RX_DROP;
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129 }
130
131 if (likely(ib_ptr->bearer)) {
132 if (likely(buf->pkt_type <= PACKET_BROADCAST)) {
133 buf->next = NULL;
134 tipc_recv_msg(buf, ib_ptr->bearer);
67981583 135 return NET_RX_SUCCESS;
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136 }
137 }
138 kfree_skb(buf);
67981583 139 return NET_RX_DROP;
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140}
141
142/**
143 * setup_bearer - setup association between InfiniBand bearer and interface
144 */
4babbaa8 145static void setup_media(struct work_struct *work)
a29a194a 146{
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147 struct ib_media *ib_ptr =
148 container_of(work, struct ib_media, setup);
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149
150 dev_add_pack(&ib_ptr->tipc_packet_type);
151}
152
153/**
4babbaa8 154 * enable_media - attach TIPC bearer to an InfiniBand interface
a29a194a 155 */
4babbaa8 156static int enable_media(struct tipc_bearer *tb_ptr)
a29a194a 157{
2537af9d 158 struct net_device *dev;
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159 struct ib_media *ib_ptr = &ib_media_array[0];
160 struct ib_media *stop = &ib_media_array[MAX_IB_MEDIA];
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161 char *driver_name = strchr((const char *)tb_ptr->name, ':') + 1;
162 int pending_dev = 0;
163
164 /* Find unused InfiniBand bearer structure */
165 while (ib_ptr->dev) {
166 if (!ib_ptr->bearer)
167 pending_dev++;
168 if (++ib_ptr == stop)
169 return pending_dev ? -EAGAIN : -EDQUOT;
170 }
171
172 /* Find device with specified name */
2537af9d 173 dev = dev_get_by_name(&init_net, driver_name);
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174 if (!dev)
175 return -ENODEV;
176
177 /* Create InfiniBand bearer for device */
178 ib_ptr->dev = dev;
179 ib_ptr->tipc_packet_type.type = htons(ETH_P_TIPC);
180 ib_ptr->tipc_packet_type.dev = dev;
181 ib_ptr->tipc_packet_type.func = recv_msg;
182 ib_ptr->tipc_packet_type.af_packet_priv = ib_ptr;
183 INIT_LIST_HEAD(&(ib_ptr->tipc_packet_type.list));
4babbaa8 184 INIT_WORK(&ib_ptr->setup, setup_media);
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185 schedule_work(&ib_ptr->setup);
186
187 /* Associate TIPC bearer with InfiniBand bearer */
188 ib_ptr->bearer = tb_ptr;
189 tb_ptr->usr_handle = (void *)ib_ptr;
190 memset(tb_ptr->bcast_addr.value, 0, sizeof(tb_ptr->bcast_addr.value));
191 memcpy(tb_ptr->bcast_addr.value, dev->broadcast, INFINIBAND_ALEN);
192 tb_ptr->bcast_addr.media_id = TIPC_MEDIA_TYPE_IB;
193 tb_ptr->bcast_addr.broadcast = 1;
194 tb_ptr->mtu = dev->mtu;
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195 ib_media_addr_set(tb_ptr, &tb_ptr->addr, (char *)dev->dev_addr);
196 return 0;
197}
198
199/**
200 * cleanup_bearer - break association between InfiniBand bearer and interface
201 *
202 * This routine must be invoked from a work queue because it can sleep.
203 */
204static void cleanup_bearer(struct work_struct *work)
205{
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206 struct ib_media *ib_ptr =
207 container_of(work, struct ib_media, cleanup);
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208
209 dev_remove_pack(&ib_ptr->tipc_packet_type);
210 dev_put(ib_ptr->dev);
211 ib_ptr->dev = NULL;
212}
213
214/**
4babbaa8 215 * disable_media - detach TIPC bearer from an InfiniBand interface
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216 *
217 * Mark InfiniBand bearer as inactive so that incoming buffers are thrown away,
218 * then get worker thread to complete bearer cleanup. (Can't do cleanup
219 * here because cleanup code needs to sleep and caller holds spinlocks.)
220 */
4babbaa8 221static void disable_media(struct tipc_bearer *tb_ptr)
a29a194a 222{
4babbaa8 223 struct ib_media *ib_ptr = (struct ib_media *)tb_ptr->usr_handle;
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224
225 ib_ptr->bearer = NULL;
226 INIT_WORK(&ib_ptr->cleanup, cleanup_bearer);
227 schedule_work(&ib_ptr->cleanup);
228}
229
230/**
231 * recv_notification - handle device updates from OS
232 *
233 * Change the state of the InfiniBand bearer (if any) associated with the
234 * specified device.
235 */
236static int recv_notification(struct notifier_block *nb, unsigned long evt,
351638e7 237 void *ptr)
a29a194a 238{
351638e7 239 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
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240 struct ib_media *ib_ptr = &ib_media_array[0];
241 struct ib_media *stop = &ib_media_array[MAX_IB_MEDIA];
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242
243 if (!net_eq(dev_net(dev), &init_net))
244 return NOTIFY_DONE;
245
246 while ((ib_ptr->dev != dev)) {
247 if (++ib_ptr == stop)
248 return NOTIFY_DONE; /* couldn't find device */
249 }
250 if (!ib_ptr->bearer)
251 return NOTIFY_DONE; /* bearer had been disabled */
252
253 ib_ptr->bearer->mtu = dev->mtu;
254
255 switch (evt) {
256 case NETDEV_CHANGE:
257 if (netif_carrier_ok(dev))
512137ee 258 break;
a29a194a 259 case NETDEV_DOWN:
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260 case NETDEV_CHANGEMTU:
261 case NETDEV_CHANGEADDR:
512137ee 262 tipc_reset_bearer(ib_ptr->bearer);
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263 break;
264 case NETDEV_UNREGISTER:
265 case NETDEV_CHANGENAME:
266 tipc_disable_bearer(ib_ptr->bearer->name);
267 break;
268 }
269 return NOTIFY_OK;
270}
271
272static struct notifier_block notifier = {
273 .notifier_call = recv_notification,
274 .priority = 0,
275};
276
277/**
278 * ib_addr2str - convert InfiniBand address to string
279 */
280static int ib_addr2str(struct tipc_media_addr *a, char *str_buf, int str_size)
281{
282 if (str_size < 60) /* 60 = 19 * strlen("xx:") + strlen("xx\0") */
283 return 1;
284
d77e41e1 285 sprintf(str_buf, "%20phC", a->value);
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286
287 return 0;
288}
289
290/**
291 * ib_addr2msg - convert InfiniBand address format to message header format
292 */
293static int ib_addr2msg(struct tipc_media_addr *a, char *msg_area)
294{
295 memset(msg_area, 0, TIPC_MEDIA_ADDR_SIZE);
296 msg_area[TIPC_MEDIA_TYPE_OFFSET] = TIPC_MEDIA_TYPE_IB;
297 memcpy(msg_area, a->value, INFINIBAND_ALEN);
298 return 0;
299}
300
301/**
302 * ib_msg2addr - convert message header address format to InfiniBand format
303 */
304static int ib_msg2addr(const struct tipc_bearer *tb_ptr,
305 struct tipc_media_addr *a, char *msg_area)
306{
307 ib_media_addr_set(tb_ptr, a, msg_area);
308 return 0;
309}
310
311/*
312 * InfiniBand media registration info
313 */
314static struct tipc_media ib_media_info = {
315 .send_msg = send_msg,
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316 .enable_media = enable_media,
317 .disable_media = disable_media,
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318 .addr2str = ib_addr2str,
319 .addr2msg = ib_addr2msg,
320 .msg2addr = ib_msg2addr,
321 .priority = TIPC_DEF_LINK_PRI,
322 .tolerance = TIPC_DEF_LINK_TOL,
323 .window = TIPC_DEF_LINK_WIN,
324 .type_id = TIPC_MEDIA_TYPE_IB,
325 .name = "ib"
326};
327
328/**
329 * tipc_ib_media_start - activate InfiniBand bearer support
330 *
331 * Register InfiniBand media type with TIPC bearer code. Also register
332 * with OS for notifications about device state changes.
333 */
334int tipc_ib_media_start(void)
335{
336 int res;
337
338 if (ib_started)
339 return -EINVAL;
340
341 res = tipc_register_media(&ib_media_info);
342 if (res)
343 return res;
344
345 res = register_netdevice_notifier(&notifier);
346 if (!res)
347 ib_started = 1;
348 return res;
349}
350
351/**
352 * tipc_ib_media_stop - deactivate InfiniBand bearer support
353 */
354void tipc_ib_media_stop(void)
355{
356 if (!ib_started)
357 return;
358
359 flush_scheduled_work();
360 unregister_netdevice_notifier(&notifier);
361 ib_started = 0;
362}