xref: /openbmc/linux/drivers/infiniband/core/smi.c (revision 4f3db074)
1 /*
2  * Copyright (c) 2004, 2005 Mellanox Technologies Ltd.  All rights reserved.
3  * Copyright (c) 2004, 2005 Infinicon Corporation.  All rights reserved.
4  * Copyright (c) 2004, 2005 Intel Corporation.  All rights reserved.
5  * Copyright (c) 2004, 2005 Topspin Corporation.  All rights reserved.
6  * Copyright (c) 2004-2007 Voltaire Corporation.  All rights reserved.
7  * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
8  *
9  * This software is available to you under a choice of one of two
10  * licenses.  You may choose to be licensed under the terms of the GNU
11  * General Public License (GPL) Version 2, available from the file
12  * COPYING in the main directory of this source tree, or the
13  * OpenIB.org BSD license below:
14  *
15  *     Redistribution and use in source and binary forms, with or
16  *     without modification, are permitted provided that the following
17  *     conditions are met:
18  *
19  *      - Redistributions of source code must retain the above
20  *        copyright notice, this list of conditions and the following
21  *        disclaimer.
22  *
23  *      - Redistributions in binary form must reproduce the above
24  *        copyright notice, this list of conditions and the following
25  *        disclaimer in the documentation and/or other materials
26  *        provided with the distribution.
27  *
28  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
29  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
30  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
31  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
32  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
33  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
34  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
35  * SOFTWARE.
36  *
37  */
38 
39 #include <rdma/ib_smi.h>
40 #include "smi.h"
41 
42 /*
43  * Fixup a directed route SMP for sending
44  * Return 0 if the SMP should be discarded
45  */
46 enum smi_action smi_handle_dr_smp_send(struct ib_smp *smp,
47 				       u8 node_type, int port_num)
48 {
49 	u8 hop_ptr, hop_cnt;
50 
51 	hop_ptr = smp->hop_ptr;
52 	hop_cnt = smp->hop_cnt;
53 
54 	/* See section 14.2.2.2, Vol 1 IB spec */
55 	/* C14-6 -- valid hop_cnt values are from 0 to 63 */
56 	if (hop_cnt >= IB_SMP_MAX_PATH_HOPS)
57 		return IB_SMI_DISCARD;
58 
59 	if (!ib_get_smp_direction(smp)) {
60 		/* C14-9:1 */
61 		if (hop_cnt && hop_ptr == 0) {
62 			smp->hop_ptr++;
63 			return (smp->initial_path[smp->hop_ptr] ==
64 				port_num ? IB_SMI_HANDLE : IB_SMI_DISCARD);
65 		}
66 
67 		/* C14-9:2 */
68 		if (hop_ptr && hop_ptr < hop_cnt) {
69 			if (node_type != RDMA_NODE_IB_SWITCH)
70 				return IB_SMI_DISCARD;
71 
72 			/* smp->return_path set when received */
73 			smp->hop_ptr++;
74 			return (smp->initial_path[smp->hop_ptr] ==
75 				port_num ? IB_SMI_HANDLE : IB_SMI_DISCARD);
76 		}
77 
78 		/* C14-9:3 -- We're at the end of the DR segment of path */
79 		if (hop_ptr == hop_cnt) {
80 			/* smp->return_path set when received */
81 			smp->hop_ptr++;
82 			return (node_type == RDMA_NODE_IB_SWITCH ||
83 				smp->dr_dlid == IB_LID_PERMISSIVE ?
84 				IB_SMI_HANDLE : IB_SMI_DISCARD);
85 		}
86 
87 		/* C14-9:4 -- hop_ptr = hop_cnt + 1 -> give to SMA/SM */
88 		/* C14-9:5 -- Fail unreasonable hop pointer */
89 		return (hop_ptr == hop_cnt + 1 ? IB_SMI_HANDLE : IB_SMI_DISCARD);
90 
91 	} else {
92 		/* C14-13:1 */
93 		if (hop_cnt && hop_ptr == hop_cnt + 1) {
94 			smp->hop_ptr--;
95 			return (smp->return_path[smp->hop_ptr] ==
96 				port_num ? IB_SMI_HANDLE : IB_SMI_DISCARD);
97 		}
98 
99 		/* C14-13:2 */
100 		if (2 <= hop_ptr && hop_ptr <= hop_cnt) {
101 			if (node_type != RDMA_NODE_IB_SWITCH)
102 				return IB_SMI_DISCARD;
103 
104 			smp->hop_ptr--;
105 			return (smp->return_path[smp->hop_ptr] ==
106 				port_num ? IB_SMI_HANDLE : IB_SMI_DISCARD);
107 		}
108 
109 		/* C14-13:3 -- at the end of the DR segment of path */
110 		if (hop_ptr == 1) {
111 			smp->hop_ptr--;
112 			/* C14-13:3 -- SMPs destined for SM shouldn't be here */
113 			return (node_type == RDMA_NODE_IB_SWITCH ||
114 				smp->dr_slid == IB_LID_PERMISSIVE ?
115 				IB_SMI_HANDLE : IB_SMI_DISCARD);
116 		}
117 
118 		/* C14-13:4 -- hop_ptr = 0 -> should have gone to SM */
119 		if (hop_ptr == 0)
120 			return IB_SMI_HANDLE;
121 
122 		/* C14-13:5 -- Check for unreasonable hop pointer */
123 		return IB_SMI_DISCARD;
124 	}
125 }
126 
127 /*
128  * Adjust information for a received SMP
129  * Return 0 if the SMP should be dropped
130  */
131 enum smi_action smi_handle_dr_smp_recv(struct ib_smp *smp, u8 node_type,
132 				       int port_num, int phys_port_cnt)
133 {
134 	u8 hop_ptr, hop_cnt;
135 
136 	hop_ptr = smp->hop_ptr;
137 	hop_cnt = smp->hop_cnt;
138 
139 	/* See section 14.2.2.2, Vol 1 IB spec */
140 	/* C14-6 -- valid hop_cnt values are from 0 to 63 */
141 	if (hop_cnt >= IB_SMP_MAX_PATH_HOPS)
142 		return IB_SMI_DISCARD;
143 
144 	if (!ib_get_smp_direction(smp)) {
145 		/* C14-9:1 -- sender should have incremented hop_ptr */
146 		if (hop_cnt && hop_ptr == 0)
147 			return IB_SMI_DISCARD;
148 
149 		/* C14-9:2 -- intermediate hop */
150 		if (hop_ptr && hop_ptr < hop_cnt) {
151 			if (node_type != RDMA_NODE_IB_SWITCH)
152 				return IB_SMI_DISCARD;
153 
154 			smp->return_path[hop_ptr] = port_num;
155 			/* smp->hop_ptr updated when sending */
156 			return (smp->initial_path[hop_ptr+1] <= phys_port_cnt ?
157 				IB_SMI_HANDLE : IB_SMI_DISCARD);
158 		}
159 
160 		/* C14-9:3 -- We're at the end of the DR segment of path */
161 		if (hop_ptr == hop_cnt) {
162 			if (hop_cnt)
163 				smp->return_path[hop_ptr] = port_num;
164 			/* smp->hop_ptr updated when sending */
165 
166 			return (node_type == RDMA_NODE_IB_SWITCH ||
167 				smp->dr_dlid == IB_LID_PERMISSIVE ?
168 				IB_SMI_HANDLE : IB_SMI_DISCARD);
169 		}
170 
171 		/* C14-9:4 -- hop_ptr = hop_cnt + 1 -> give to SMA/SM */
172 		/* C14-9:5 -- fail unreasonable hop pointer */
173 		return (hop_ptr == hop_cnt + 1 ? IB_SMI_HANDLE : IB_SMI_DISCARD);
174 
175 	} else {
176 
177 		/* C14-13:1 */
178 		if (hop_cnt && hop_ptr == hop_cnt + 1) {
179 			smp->hop_ptr--;
180 			return (smp->return_path[smp->hop_ptr] ==
181 				port_num ? IB_SMI_HANDLE : IB_SMI_DISCARD);
182 		}
183 
184 		/* C14-13:2 */
185 		if (2 <= hop_ptr && hop_ptr <= hop_cnt) {
186 			if (node_type != RDMA_NODE_IB_SWITCH)
187 				return IB_SMI_DISCARD;
188 
189 			/* smp->hop_ptr updated when sending */
190 			return (smp->return_path[hop_ptr-1] <= phys_port_cnt ?
191 				IB_SMI_HANDLE : IB_SMI_DISCARD);
192 		}
193 
194 		/* C14-13:3 -- We're at the end of the DR segment of path */
195 		if (hop_ptr == 1) {
196 			if (smp->dr_slid == IB_LID_PERMISSIVE) {
197 				/* giving SMP to SM - update hop_ptr */
198 				smp->hop_ptr--;
199 				return IB_SMI_HANDLE;
200 			}
201 			/* smp->hop_ptr updated when sending */
202 			return (node_type == RDMA_NODE_IB_SWITCH ?
203 				IB_SMI_HANDLE : IB_SMI_DISCARD);
204 		}
205 
206 		/* C14-13:4 -- hop_ptr = 0 -> give to SM */
207 		/* C14-13:5 -- Check for unreasonable hop pointer */
208 		return (hop_ptr == 0 ? IB_SMI_HANDLE : IB_SMI_DISCARD);
209 	}
210 }
211 
212 enum smi_forward_action smi_check_forward_dr_smp(struct ib_smp *smp)
213 {
214 	u8 hop_ptr, hop_cnt;
215 
216 	hop_ptr = smp->hop_ptr;
217 	hop_cnt = smp->hop_cnt;
218 
219 	if (!ib_get_smp_direction(smp)) {
220 		/* C14-9:2 -- intermediate hop */
221 		if (hop_ptr && hop_ptr < hop_cnt)
222 			return IB_SMI_FORWARD;
223 
224 		/* C14-9:3 -- at the end of the DR segment of path */
225 		if (hop_ptr == hop_cnt)
226 			return (smp->dr_dlid == IB_LID_PERMISSIVE ?
227 				IB_SMI_SEND : IB_SMI_LOCAL);
228 
229 		/* C14-9:4 -- hop_ptr = hop_cnt + 1 -> give to SMA/SM */
230 		if (hop_ptr == hop_cnt + 1)
231 			return IB_SMI_SEND;
232 	} else {
233 		/* C14-13:2  -- intermediate hop */
234 		if (2 <= hop_ptr && hop_ptr <= hop_cnt)
235 			return IB_SMI_FORWARD;
236 
237 		/* C14-13:3 -- at the end of the DR segment of path */
238 		if (hop_ptr == 1)
239 			return (smp->dr_slid != IB_LID_PERMISSIVE ?
240 				IB_SMI_SEND : IB_SMI_LOCAL);
241 	}
242 	return IB_SMI_LOCAL;
243 }
244 
245 /*
246  * Return the forwarding port number from initial_path for outgoing SMP and
247  * from return_path for returning SMP
248  */
249 int smi_get_fwd_port(struct ib_smp *smp)
250 {
251 	return (!ib_get_smp_direction(smp) ? smp->initial_path[smp->hop_ptr+1] :
252 		smp->return_path[smp->hop_ptr-1]);
253 }
254