1 ============================================== 1 ==============================================================================
2 NUMA binding description. 2 NUMA binding description.
3 ============================================== 3 ==============================================================================
4 4
5 ============================================== 5 ==============================================================================
6 1 - Introduction 6 1 - Introduction
7 ============================================== 7 ==============================================================================
8 8
9 Systems employing a Non Uniform Memory Access 9 Systems employing a Non Uniform Memory Access (NUMA) architecture contain
10 collections of hardware resources including pr 10 collections of hardware resources including processors, memory, and I/O buses,
11 that comprise what is commonly known as a NUMA 11 that comprise what is commonly known as a NUMA node.
12 Processor accesses to memory within the local 12 Processor accesses to memory within the local NUMA node is generally faster
13 than processor accesses to memory outside of t 13 than processor accesses to memory outside of the local NUMA node.
14 DT defines interfaces that allow the platform 14 DT defines interfaces that allow the platform to convey NUMA node
15 topology information to OS. 15 topology information to OS.
16 16
17 ============================================== 17 ==============================================================================
18 2 - numa-node-id 18 2 - numa-node-id
19 ============================================== 19 ==============================================================================
20 20
21 For the purpose of identification, each NUMA n 21 For the purpose of identification, each NUMA node is associated with a unique
22 token known as a node id. For the purpose of t 22 token known as a node id. For the purpose of this binding
23 a node id is a 32-bit integer. 23 a node id is a 32-bit integer.
24 24
25 A device node is associated with a NUMA node b 25 A device node is associated with a NUMA node by the presence of a
26 numa-node-id property which contains the node 26 numa-node-id property which contains the node id of the device.
27 27
28 Example: 28 Example:
29 /* numa node 0 */ 29 /* numa node 0 */
30 numa-node-id = <0>; 30 numa-node-id = <0>;
31 31
32 /* numa node 1 */ 32 /* numa node 1 */
33 numa-node-id = <1>; 33 numa-node-id = <1>;
34 34
35 ============================================== 35 ==============================================================================
36 3 - distance-map 36 3 - distance-map
37 ============================================== 37 ==============================================================================
38 38
39 The optional device tree node distance-map des 39 The optional device tree node distance-map describes the relative
40 distance (memory latency) between all numa nod 40 distance (memory latency) between all numa nodes.
41 41
42 - compatible : Should at least contain "numa-d 42 - compatible : Should at least contain "numa-distance-map-v1".
43 43
44 - distance-matrix 44 - distance-matrix
45 This property defines a matrix to describe t 45 This property defines a matrix to describe the relative distances
46 between all numa nodes. 46 between all numa nodes.
47 It is represented as a list of node pairs an 47 It is represented as a list of node pairs and their relative distance.
48 48
49 Note: 49 Note:
50 1. Each entry represents distance from 50 1. Each entry represents distance from first node to second node.
51 The distances are equal in either dire 51 The distances are equal in either direction.
52 2. The distance from a node to self (l 52 2. The distance from a node to self (local distance) is represented
53 with value 10 and all internode distan 53 with value 10 and all internode distance should be represented with
54 a value greater than 10. 54 a value greater than 10.
55 3. distance-matrix should have entries 55 3. distance-matrix should have entries in lexicographical ascending
56 order of nodes. 56 order of nodes.
57 4. There must be only one device node 57 4. There must be only one device node distance-map which must
58 reside in the root node. 58 reside in the root node.
59 5. If the distance-map node is not pre 59 5. If the distance-map node is not present, a default
60 distance-matrix is used. 60 distance-matrix is used.
61 61
62 Example: 62 Example:
63 4 nodes connected in mesh/ring topolog 63 4 nodes connected in mesh/ring topology as below,
64 64
65 0_______20______1 65 0_______20______1
66 | | 66 | |
67 | | 67 | |
68 20 20 68 20 20
69 | | 69 | |
70 | | 70 | |
71 |_______________| 71 |_______________|
72 3 20 2 72 3 20 2
73 73
74 if relative distance for each hop is 2 74 if relative distance for each hop is 20,
75 then internode distance would be, 75 then internode distance would be,
76 0 -> 1 = 20 76 0 -> 1 = 20
77 1 -> 2 = 20 77 1 -> 2 = 20
78 2 -> 3 = 20 78 2 -> 3 = 20
79 3 -> 0 = 20 79 3 -> 0 = 20
80 0 -> 2 = 40 80 0 -> 2 = 40
81 1 -> 3 = 40 81 1 -> 3 = 40
82 82
83 and dt presentation for this distance mat 83 and dt presentation for this distance matrix is,
84 84
85 distance-map { 85 distance-map {
86 compatible = "numa-di 86 compatible = "numa-distance-map-v1";
87 distance-matrix = <0 87 distance-matrix = <0 0 10>,
88 <0 88 <0 1 20>,
89 <0 89 <0 2 40>,
90 <0 90 <0 3 20>,
91 <1 91 <1 0 20>,
92 <1 92 <1 1 10>,
93 <1 93 <1 2 20>,
94 <1 94 <1 3 40>,
95 <2 95 <2 0 40>,
96 <2 96 <2 1 20>,
97 <2 97 <2 2 10>,
98 <2 98 <2 3 20>,
99 <3 99 <3 0 20>,
100 <3 100 <3 1 40>,
101 <3 101 <3 2 20>,
102 <3 102 <3 3 10>;
103 }; 103 };
104 104
105 ============================================== 105 ==============================================================================
106 4 - Empty memory nodes !! 106 4 - Example dts
107 ============================================== <<
108 <<
109 Empty memory nodes, which no memory resides in <<
110 device nodes for these empty memory nodes. How <<
111 distance maps are still valid and memory may b <<
112 hotplug afterwards. <<
113 <<
114 Example: <<
115 <<
116 memory@0 { <<
117 device_type = "memory"; <<
118 reg = <0x0 0x0 0x0 0x80000000> <<
119 numa-node-id = <0>; <<
120 }; <<
121 <<
122 memory@80000000 { <<
123 device_type = "memory"; <<
124 reg = <0x0 0x80000000 0x0 0x80 <<
125 numa-node-id = <1>; <<
126 }; <<
127 <<
128 /* Empty memory node 2 and 3 */ <<
129 distance-map { <<
130 compatible = "numa-distance-ma <<
131 distance-matrix = <0 0 10>, <<
132 <0 1 20>, <<
133 <0 2 40>, <<
134 <0 3 20>, <<
135 <1 0 20>, <<
136 <1 1 10>, <<
137 <1 2 20>, <<
138 <1 3 40>, <<
139 <2 0 40>, <<
140 <2 1 20>, <<
141 <2 2 10>, <<
142 <2 3 20>, <<
143 <3 0 20>, <<
144 <3 1 40>, <<
145 <3 2 20>, <<
146 <3 3 10>; <<
147 }; <<
148 <<
149 ============================================== <<
150 5 - Example dts <<
151 ============================================== 107 ==============================================================================
152 108
153 Dual socket system consists of 2 boards connec 109 Dual socket system consists of 2 boards connected through ccn bus and
154 each board having one socket/soc of 8 cpus, me 110 each board having one socket/soc of 8 cpus, memory and pci bus.
155 111
156 memory@c00000 { 112 memory@c00000 {
157 device_type = "memory"; 113 device_type = "memory";
158 reg = <0x0 0xc00000 0x0 0x8000 114 reg = <0x0 0xc00000 0x0 0x80000000>;
159 /* node 0 */ 115 /* node 0 */
160 numa-node-id = <0>; 116 numa-node-id = <0>;
161 }; 117 };
162 118
163 memory@10000000000 { 119 memory@10000000000 {
164 device_type = "memory"; 120 device_type = "memory";
165 reg = <0x100 0x0 0x0 0x8000000 121 reg = <0x100 0x0 0x0 0x80000000>;
166 /* node 1 */ 122 /* node 1 */
167 numa-node-id = <1>; 123 numa-node-id = <1>;
168 }; 124 };
169 125
170 cpus { 126 cpus {
171 #address-cells = <2>; 127 #address-cells = <2>;
172 #size-cells = <0>; 128 #size-cells = <0>;
173 129
174 cpu@0 { 130 cpu@0 {
175 device_type = "cpu"; 131 device_type = "cpu";
176 compatible = "arm,arm 132 compatible = "arm,armv8";
177 reg = <0x0 0x0>; 133 reg = <0x0 0x0>;
178 enable-method = "psci" 134 enable-method = "psci";
179 /* node 0 */ 135 /* node 0 */
180 numa-node-id = <0>; 136 numa-node-id = <0>;
181 }; 137 };
182 cpu@1 { 138 cpu@1 {
183 device_type = "cpu"; 139 device_type = "cpu";
184 compatible = "arm,arm 140 compatible = "arm,armv8";
185 reg = <0x0 0x1>; 141 reg = <0x0 0x1>;
186 enable-method = "psci" 142 enable-method = "psci";
187 numa-node-id = <0>; 143 numa-node-id = <0>;
188 }; 144 };
189 cpu@2 { 145 cpu@2 {
190 device_type = "cpu"; 146 device_type = "cpu";
191 compatible = "arm,arm 147 compatible = "arm,armv8";
192 reg = <0x0 0x2>; 148 reg = <0x0 0x2>;
193 enable-method = "psci" 149 enable-method = "psci";
194 numa-node-id = <0>; 150 numa-node-id = <0>;
195 }; 151 };
196 cpu@3 { 152 cpu@3 {
197 device_type = "cpu"; 153 device_type = "cpu";
198 compatible = "arm,arm 154 compatible = "arm,armv8";
199 reg = <0x0 0x3>; 155 reg = <0x0 0x3>;
200 enable-method = "psci" 156 enable-method = "psci";
201 numa-node-id = <0>; 157 numa-node-id = <0>;
202 }; 158 };
203 cpu@4 { 159 cpu@4 {
204 device_type = "cpu"; 160 device_type = "cpu";
205 compatible = "arm,arm 161 compatible = "arm,armv8";
206 reg = <0x0 0x4>; 162 reg = <0x0 0x4>;
207 enable-method = "psci" 163 enable-method = "psci";
208 numa-node-id = <0>; 164 numa-node-id = <0>;
209 }; 165 };
210 cpu@5 { 166 cpu@5 {
211 device_type = "cpu"; 167 device_type = "cpu";
212 compatible = "arm,arm 168 compatible = "arm,armv8";
213 reg = <0x0 0x5>; 169 reg = <0x0 0x5>;
214 enable-method = "psci" 170 enable-method = "psci";
215 numa-node-id = <0>; 171 numa-node-id = <0>;
216 }; 172 };
217 cpu@6 { 173 cpu@6 {
218 device_type = "cpu"; 174 device_type = "cpu";
219 compatible = "arm,arm 175 compatible = "arm,armv8";
220 reg = <0x0 0x6>; 176 reg = <0x0 0x6>;
221 enable-method = "psci" 177 enable-method = "psci";
222 numa-node-id = <0>; 178 numa-node-id = <0>;
223 }; 179 };
224 cpu@7 { 180 cpu@7 {
225 device_type = "cpu"; 181 device_type = "cpu";
226 compatible = "arm,arm 182 compatible = "arm,armv8";
227 reg = <0x0 0x7>; 183 reg = <0x0 0x7>;
228 enable-method = "psci" 184 enable-method = "psci";
229 numa-node-id = <0>; 185 numa-node-id = <0>;
230 }; 186 };
231 cpu@8 { 187 cpu@8 {
232 device_type = "cpu"; 188 device_type = "cpu";
233 compatible = "arm,arm 189 compatible = "arm,armv8";
234 reg = <0x0 0x8>; 190 reg = <0x0 0x8>;
235 enable-method = "psci" 191 enable-method = "psci";
236 /* node 1 */ 192 /* node 1 */
237 numa-node-id = <1>; 193 numa-node-id = <1>;
238 }; 194 };
239 cpu@9 { 195 cpu@9 {
240 device_type = "cpu"; 196 device_type = "cpu";
241 compatible = "arm,arm 197 compatible = "arm,armv8";
242 reg = <0x0 0x9>; 198 reg = <0x0 0x9>;
243 enable-method = "psci" 199 enable-method = "psci";
244 numa-node-id = <1>; 200 numa-node-id = <1>;
245 }; 201 };
246 cpu@a { 202 cpu@a {
247 device_type = "cpu"; 203 device_type = "cpu";
248 compatible = "arm,arm 204 compatible = "arm,armv8";
249 reg = <0x0 0xa>; 205 reg = <0x0 0xa>;
250 enable-method = "psci" 206 enable-method = "psci";
251 numa-node-id = <1>; 207 numa-node-id = <1>;
252 }; 208 };
253 cpu@b { 209 cpu@b {
254 device_type = "cpu"; 210 device_type = "cpu";
255 compatible = "arm,arm 211 compatible = "arm,armv8";
256 reg = <0x0 0xb>; 212 reg = <0x0 0xb>;
257 enable-method = "psci" 213 enable-method = "psci";
258 numa-node-id = <1>; 214 numa-node-id = <1>;
259 }; 215 };
260 cpu@c { 216 cpu@c {
261 device_type = "cpu"; 217 device_type = "cpu";
262 compatible = "arm,arm 218 compatible = "arm,armv8";
263 reg = <0x0 0xc>; 219 reg = <0x0 0xc>;
264 enable-method = "psci" 220 enable-method = "psci";
265 numa-node-id = <1>; 221 numa-node-id = <1>;
266 }; 222 };
267 cpu@d { 223 cpu@d {
268 device_type = "cpu"; 224 device_type = "cpu";
269 compatible = "arm,arm 225 compatible = "arm,armv8";
270 reg = <0x0 0xd>; 226 reg = <0x0 0xd>;
271 enable-method = "psci" 227 enable-method = "psci";
272 numa-node-id = <1>; 228 numa-node-id = <1>;
273 }; 229 };
274 cpu@e { 230 cpu@e {
275 device_type = "cpu"; 231 device_type = "cpu";
276 compatible = "arm,arm 232 compatible = "arm,armv8";
277 reg = <0x0 0xe>; 233 reg = <0x0 0xe>;
278 enable-method = "psci" 234 enable-method = "psci";
279 numa-node-id = <1>; 235 numa-node-id = <1>;
280 }; 236 };
281 cpu@f { 237 cpu@f {
282 device_type = "cpu"; 238 device_type = "cpu";
283 compatible = "arm,arm 239 compatible = "arm,armv8";
284 reg = <0x0 0xf>; 240 reg = <0x0 0xf>;
285 enable-method = "psci" 241 enable-method = "psci";
286 numa-node-id = <1>; 242 numa-node-id = <1>;
287 }; 243 };
288 }; 244 };
289 245
290 pcie0: pcie0@848000000000 { 246 pcie0: pcie0@848000000000 {
291 compatible = "arm,armv8"; 247 compatible = "arm,armv8";
292 device_type = "pci"; 248 device_type = "pci";
293 bus-range = <0 255>; 249 bus-range = <0 255>;
294 #size-cells = <2>; 250 #size-cells = <2>;
295 #address-cells = <3>; 251 #address-cells = <3>;
296 reg = <0x8480 0x00000000 0 0x1 252 reg = <0x8480 0x00000000 0 0x10000000>; /* Configuration space */
297 ranges = <0x03000000 0x8010 0x 253 ranges = <0x03000000 0x8010 0x00000000 0x8010 0x00000000 0x70 0x00000000>;
298 /* node 0 */ 254 /* node 0 */
299 numa-node-id = <0>; 255 numa-node-id = <0>;
300 }; 256 };
301 257
302 pcie1: pcie1@948000000000 { 258 pcie1: pcie1@948000000000 {
303 compatible = "arm,armv8"; 259 compatible = "arm,armv8";
304 device_type = "pci"; 260 device_type = "pci";
305 bus-range = <0 255>; 261 bus-range = <0 255>;
306 #size-cells = <2>; 262 #size-cells = <2>;
307 #address-cells = <3>; 263 #address-cells = <3>;
308 reg = <0x9480 0x00000000 0 0x1 264 reg = <0x9480 0x00000000 0 0x10000000>; /* Configuration space */
309 ranges = <0x03000000 0x9010 0x 265 ranges = <0x03000000 0x9010 0x00000000 0x9010 0x00000000 0x70 0x00000000>;
310 /* node 1 */ 266 /* node 1 */
311 numa-node-id = <1>; 267 numa-node-id = <1>;
312 }; 268 };
313 269
314 distance-map { 270 distance-map {
315 compatible = "numa-distance-ma 271 compatible = "numa-distance-map-v1";
316 distance-matrix = <0 0 10>, 272 distance-matrix = <0 0 10>,
317 <0 1 20>, 273 <0 1 20>,
318 <1 1 10>; 274 <1 1 10>;
319 }; 275 };
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