xref: /openbmc/linux/drivers/infiniband/core/smi.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
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 	if (!ib_get_smp_direction(smp)) {
56 		/* C14-9:1 */
57 		if (hop_cnt && hop_ptr == 0) {
58 			smp->hop_ptr++;
59 			return (smp->initial_path[smp->hop_ptr] ==
60 				port_num ? IB_SMI_HANDLE : IB_SMI_DISCARD);
61 		}
62 
63 		/* C14-9:2 */
64 		if (hop_ptr && hop_ptr < hop_cnt) {
65 			if (node_type != RDMA_NODE_IB_SWITCH)
66 				return IB_SMI_DISCARD;
67 
68 			/* smp->return_path set when received */
69 			smp->hop_ptr++;
70 			return (smp->initial_path[smp->hop_ptr] ==
71 				port_num ? IB_SMI_HANDLE : IB_SMI_DISCARD);
72 		}
73 
74 		/* C14-9:3 -- We're at the end of the DR segment of path */
75 		if (hop_ptr == hop_cnt) {
76 			/* smp->return_path set when received */
77 			smp->hop_ptr++;
78 			return (node_type == RDMA_NODE_IB_SWITCH ||
79 				smp->dr_dlid == IB_LID_PERMISSIVE ?
80 				IB_SMI_HANDLE : IB_SMI_DISCARD);
81 		}
82 
83 		/* C14-9:4 -- hop_ptr = hop_cnt + 1 -> give to SMA/SM */
84 		/* C14-9:5 -- Fail unreasonable hop pointer */
85 		return (hop_ptr == hop_cnt + 1 ? IB_SMI_HANDLE : IB_SMI_DISCARD);
86 
87 	} else {
88 		/* C14-13:1 */
89 		if (hop_cnt && hop_ptr == hop_cnt + 1) {
90 			smp->hop_ptr--;
91 			return (smp->return_path[smp->hop_ptr] ==
92 				port_num ? IB_SMI_HANDLE : IB_SMI_DISCARD);
93 		}
94 
95 		/* C14-13:2 */
96 		if (2 <= hop_ptr && hop_ptr <= hop_cnt) {
97 			if (node_type != RDMA_NODE_IB_SWITCH)
98 				return IB_SMI_DISCARD;
99 
100 			smp->hop_ptr--;
101 			return (smp->return_path[smp->hop_ptr] ==
102 				port_num ? IB_SMI_HANDLE : IB_SMI_DISCARD);
103 		}
104 
105 		/* C14-13:3 -- at the end of the DR segment of path */
106 		if (hop_ptr == 1) {
107 			smp->hop_ptr--;
108 			/* C14-13:3 -- SMPs destined for SM shouldn't be here */
109 			return (node_type == RDMA_NODE_IB_SWITCH ||
110 				smp->dr_slid == IB_LID_PERMISSIVE ?
111 				IB_SMI_HANDLE : IB_SMI_DISCARD);
112 		}
113 
114 		/* C14-13:4 -- hop_ptr = 0 -> should have gone to SM */
115 		if (hop_ptr == 0)
116 			return IB_SMI_HANDLE;
117 
118 		/* C14-13:5 -- Check for unreasonable hop pointer */
119 		return IB_SMI_DISCARD;
120 	}
121 }
122 
123 /*
124  * Adjust information for a received SMP
125  * Return 0 if the SMP should be dropped
126  */
127 enum smi_action smi_handle_dr_smp_recv(struct ib_smp *smp, u8 node_type,
128 				       int port_num, int phys_port_cnt)
129 {
130 	u8 hop_ptr, hop_cnt;
131 
132 	hop_ptr = smp->hop_ptr;
133 	hop_cnt = smp->hop_cnt;
134 
135 	/* See section 14.2.2.2, Vol 1 IB spec */
136 	if (!ib_get_smp_direction(smp)) {
137 		/* C14-9:1 -- sender should have incremented hop_ptr */
138 		if (hop_cnt && hop_ptr == 0)
139 			return IB_SMI_DISCARD;
140 
141 		/* C14-9:2 -- intermediate hop */
142 		if (hop_ptr && hop_ptr < hop_cnt) {
143 			if (node_type != RDMA_NODE_IB_SWITCH)
144 				return IB_SMI_DISCARD;
145 
146 			smp->return_path[hop_ptr] = port_num;
147 			/* smp->hop_ptr updated when sending */
148 			return (smp->initial_path[hop_ptr+1] <= phys_port_cnt ?
149 				IB_SMI_HANDLE : IB_SMI_DISCARD);
150 		}
151 
152 		/* C14-9:3 -- We're at the end of the DR segment of path */
153 		if (hop_ptr == hop_cnt) {
154 			if (hop_cnt)
155 				smp->return_path[hop_ptr] = port_num;
156 			/* smp->hop_ptr updated when sending */
157 
158 			return (node_type == RDMA_NODE_IB_SWITCH ||
159 				smp->dr_dlid == IB_LID_PERMISSIVE ?
160 				IB_SMI_HANDLE : IB_SMI_DISCARD);
161 		}
162 
163 		/* C14-9:4 -- hop_ptr = hop_cnt + 1 -> give to SMA/SM */
164 		/* C14-9:5 -- fail unreasonable hop pointer */
165 		return (hop_ptr == hop_cnt + 1 ? IB_SMI_HANDLE : IB_SMI_DISCARD);
166 
167 	} else {
168 
169 		/* C14-13:1 */
170 		if (hop_cnt && hop_ptr == hop_cnt + 1) {
171 			smp->hop_ptr--;
172 			return (smp->return_path[smp->hop_ptr] ==
173 				port_num ? IB_SMI_HANDLE : IB_SMI_DISCARD);
174 		}
175 
176 		/* C14-13:2 */
177 		if (2 <= hop_ptr && hop_ptr <= hop_cnt) {
178 			if (node_type != RDMA_NODE_IB_SWITCH)
179 				return IB_SMI_DISCARD;
180 
181 			/* smp->hop_ptr updated when sending */
182 			return (smp->return_path[hop_ptr-1] <= phys_port_cnt ?
183 				IB_SMI_HANDLE : IB_SMI_DISCARD);
184 		}
185 
186 		/* C14-13:3 -- We're at the end of the DR segment of path */
187 		if (hop_ptr == 1) {
188 			if (smp->dr_slid == IB_LID_PERMISSIVE) {
189 				/* giving SMP to SM - update hop_ptr */
190 				smp->hop_ptr--;
191 				return IB_SMI_HANDLE;
192 			}
193 			/* smp->hop_ptr updated when sending */
194 			return (node_type == RDMA_NODE_IB_SWITCH ?
195 				IB_SMI_HANDLE : IB_SMI_DISCARD);
196 		}
197 
198 		/* C14-13:4 -- hop_ptr = 0 -> give to SM */
199 		/* C14-13:5 -- Check for unreasonable hop pointer */
200 		return (hop_ptr == 0 ? IB_SMI_HANDLE : IB_SMI_DISCARD);
201 	}
202 }
203 
204 enum smi_forward_action smi_check_forward_dr_smp(struct ib_smp *smp)
205 {
206 	u8 hop_ptr, hop_cnt;
207 
208 	hop_ptr = smp->hop_ptr;
209 	hop_cnt = smp->hop_cnt;
210 
211 	if (!ib_get_smp_direction(smp)) {
212 		/* C14-9:2 -- intermediate hop */
213 		if (hop_ptr && hop_ptr < hop_cnt)
214 			return IB_SMI_FORWARD;
215 
216 		/* C14-9:3 -- at the end of the DR segment of path */
217 		if (hop_ptr == hop_cnt)
218 			return (smp->dr_dlid == IB_LID_PERMISSIVE ?
219 				IB_SMI_SEND : IB_SMI_LOCAL);
220 
221 		/* C14-9:4 -- hop_ptr = hop_cnt + 1 -> give to SMA/SM */
222 		if (hop_ptr == hop_cnt + 1)
223 			return IB_SMI_SEND;
224 	} else {
225 		/* C14-13:2  -- intermediate hop */
226 		if (2 <= hop_ptr && hop_ptr <= hop_cnt)
227 			return IB_SMI_FORWARD;
228 
229 		/* C14-13:3 -- at the end of the DR segment of path */
230 		if (hop_ptr == 1)
231 			return (smp->dr_slid != IB_LID_PERMISSIVE ?
232 				IB_SMI_SEND : IB_SMI_LOCAL);
233 	}
234 	return IB_SMI_LOCAL;
235 }
236 
237 /*
238  * Return the forwarding port number from initial_path for outgoing SMP and
239  * from return_path for returning SMP
240  */
241 int smi_get_fwd_port(struct ib_smp *smp)
242 {
243 	return (!ib_get_smp_direction(smp) ? smp->initial_path[smp->hop_ptr+1] :
244 		smp->return_path[smp->hop_ptr-1]);
245 }
246