xref: /openbmc/linux/drivers/of/of_numa.c (revision 3805e6a1)
1 /*
2  * OF NUMA Parsing support.
3  *
4  * Copyright (C) 2015 - 2016 Cavium Inc.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #include <linux/of.h>
20 #include <linux/of_address.h>
21 #include <linux/nodemask.h>
22 
23 #include <asm/numa.h>
24 
25 /* define default numa node to 0 */
26 #define DEFAULT_NODE 0
27 
28 /*
29  * Even though we connect cpus to numa domains later in SMP
30  * init, we need to know the node ids now for all cpus.
31 */
32 static void __init of_numa_parse_cpu_nodes(void)
33 {
34 	u32 nid;
35 	int r;
36 	struct device_node *cpus;
37 	struct device_node *np = NULL;
38 
39 	cpus = of_find_node_by_path("/cpus");
40 	if (!cpus)
41 		return;
42 
43 	for_each_child_of_node(cpus, np) {
44 		/* Skip things that are not CPUs */
45 		if (of_node_cmp(np->type, "cpu") != 0)
46 			continue;
47 
48 		r = of_property_read_u32(np, "numa-node-id", &nid);
49 		if (r)
50 			continue;
51 
52 		pr_debug("NUMA: CPU on %u\n", nid);
53 		if (nid >= MAX_NUMNODES)
54 			pr_warn("NUMA: Node id %u exceeds maximum value\n",
55 				nid);
56 		else
57 			node_set(nid, numa_nodes_parsed);
58 	}
59 }
60 
61 static int __init of_numa_parse_memory_nodes(void)
62 {
63 	struct device_node *np = NULL;
64 	struct resource rsrc;
65 	u32 nid;
66 	int r = 0;
67 
68 	for (;;) {
69 		np = of_find_node_by_type(np, "memory");
70 		if (!np)
71 			break;
72 
73 		r = of_property_read_u32(np, "numa-node-id", &nid);
74 		if (r == -EINVAL)
75 			/*
76 			 * property doesn't exist if -EINVAL, continue
77 			 * looking for more memory nodes with
78 			 * "numa-node-id" property
79 			 */
80 			continue;
81 		else if (r)
82 			/* some other error */
83 			break;
84 
85 		r = of_address_to_resource(np, 0, &rsrc);
86 		if (r) {
87 			pr_err("NUMA: bad reg property in memory node\n");
88 			break;
89 		}
90 
91 		pr_debug("NUMA:  base = %llx len = %llx, node = %u\n",
92 			 rsrc.start, rsrc.end - rsrc.start + 1, nid);
93 
94 		r = numa_add_memblk(nid, rsrc.start,
95 				    rsrc.end - rsrc.start + 1);
96 		if (r)
97 			break;
98 	}
99 	of_node_put(np);
100 
101 	return r;
102 }
103 
104 static int __init of_numa_parse_distance_map_v1(struct device_node *map)
105 {
106 	const __be32 *matrix;
107 	int entry_count;
108 	int i;
109 
110 	pr_info("NUMA: parsing numa-distance-map-v1\n");
111 
112 	matrix = of_get_property(map, "distance-matrix", NULL);
113 	if (!matrix) {
114 		pr_err("NUMA: No distance-matrix property in distance-map\n");
115 		return -EINVAL;
116 	}
117 
118 	entry_count = of_property_count_u32_elems(map, "distance-matrix");
119 	if (entry_count <= 0) {
120 		pr_err("NUMA: Invalid distance-matrix\n");
121 		return -EINVAL;
122 	}
123 
124 	for (i = 0; i + 2 < entry_count; i += 3) {
125 		u32 nodea, nodeb, distance;
126 
127 		nodea = of_read_number(matrix, 1);
128 		matrix++;
129 		nodeb = of_read_number(matrix, 1);
130 		matrix++;
131 		distance = of_read_number(matrix, 1);
132 		matrix++;
133 
134 		numa_set_distance(nodea, nodeb, distance);
135 		pr_debug("NUMA:  distance[node%d -> node%d] = %d\n",
136 			 nodea, nodeb, distance);
137 
138 		/* Set default distance of node B->A same as A->B */
139 		if (nodeb > nodea)
140 			numa_set_distance(nodeb, nodea, distance);
141 	}
142 
143 	return 0;
144 }
145 
146 static int __init of_numa_parse_distance_map(void)
147 {
148 	int ret = 0;
149 	struct device_node *np;
150 
151 	np = of_find_compatible_node(NULL, NULL,
152 				     "numa-distance-map-v1");
153 	if (np)
154 		ret = of_numa_parse_distance_map_v1(np);
155 
156 	of_node_put(np);
157 	return ret;
158 }
159 
160 int of_node_to_nid(struct device_node *device)
161 {
162 	struct device_node *np;
163 	u32 nid;
164 	int r = -ENODATA;
165 
166 	np = of_node_get(device);
167 
168 	while (np) {
169 		struct device_node *parent;
170 
171 		r = of_property_read_u32(np, "numa-node-id", &nid);
172 		/*
173 		 * -EINVAL indicates the property was not found, and
174 		 *  we walk up the tree trying to find a parent with a
175 		 *  "numa-node-id".  Any other type of error indicates
176 		 *  a bad device tree and we give up.
177 		 */
178 		if (r != -EINVAL)
179 			break;
180 
181 		parent = of_get_parent(np);
182 		of_node_put(np);
183 		np = parent;
184 	}
185 	if (np && r)
186 		pr_warn("NUMA: Invalid \"numa-node-id\" property in node %s\n",
187 			np->name);
188 	of_node_put(np);
189 
190 	if (!r) {
191 		if (nid >= MAX_NUMNODES)
192 			pr_warn("NUMA: Node id %u exceeds maximum value\n",
193 				nid);
194 		else
195 			return nid;
196 	}
197 
198 	return NUMA_NO_NODE;
199 }
200 EXPORT_SYMBOL(of_node_to_nid);
201 
202 int __init of_numa_init(void)
203 {
204 	int r;
205 
206 	of_numa_parse_cpu_nodes();
207 	r = of_numa_parse_memory_nodes();
208 	if (r)
209 		return r;
210 	return of_numa_parse_distance_map();
211 }
212