xref: /linux/drivers/of/of_numa.c (revision fd639726bf15fca8ee1a00dce8e0096d0ad9bd18)
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 #define pr_fmt(fmt) "OF: NUMA: " fmt
20 
21 #include <linux/of.h>
22 #include <linux/of_address.h>
23 #include <linux/nodemask.h>
24 
25 #include <asm/numa.h>
26 
27 /* define default numa node to 0 */
28 #define DEFAULT_NODE 0
29 
30 /*
31  * Even though we connect cpus to numa domains later in SMP
32  * init, we need to know the node ids now for all cpus.
33 */
34 static void __init of_numa_parse_cpu_nodes(void)
35 {
36 	u32 nid;
37 	int r;
38 	struct device_node *cpus;
39 	struct device_node *np = NULL;
40 
41 	cpus = of_find_node_by_path("/cpus");
42 	if (!cpus)
43 		return;
44 
45 	for_each_child_of_node(cpus, np) {
46 		/* Skip things that are not CPUs */
47 		if (of_node_cmp(np->type, "cpu") != 0)
48 			continue;
49 
50 		r = of_property_read_u32(np, "numa-node-id", &nid);
51 		if (r)
52 			continue;
53 
54 		pr_debug("CPU on %u\n", nid);
55 		if (nid >= MAX_NUMNODES)
56 			pr_warn("Node id %u exceeds maximum value\n", nid);
57 		else
58 			node_set(nid, numa_nodes_parsed);
59 	}
60 
61 	of_node_put(cpus);
62 }
63 
64 static int __init of_numa_parse_memory_nodes(void)
65 {
66 	struct device_node *np = NULL;
67 	struct resource rsrc;
68 	u32 nid;
69 	int i, r;
70 
71 	for_each_node_by_type(np, "memory") {
72 		r = of_property_read_u32(np, "numa-node-id", &nid);
73 		if (r == -EINVAL)
74 			/*
75 			 * property doesn't exist if -EINVAL, continue
76 			 * looking for more memory nodes with
77 			 * "numa-node-id" property
78 			 */
79 			continue;
80 
81 		if (nid >= MAX_NUMNODES) {
82 			pr_warn("Node id %u exceeds maximum value\n", nid);
83 			r = -EINVAL;
84 		}
85 
86 		for (i = 0; !r && !of_address_to_resource(np, i, &rsrc); i++)
87 			r = numa_add_memblk(nid, rsrc.start, rsrc.end + 1);
88 
89 		if (!i || r) {
90 			of_node_put(np);
91 			pr_err("bad property in memory node\n");
92 			return r ? : -EINVAL;
93 		}
94 	}
95 
96 	return 0;
97 }
98 
99 static int __init of_numa_parse_distance_map_v1(struct device_node *map)
100 {
101 	const __be32 *matrix;
102 	int entry_count;
103 	int i;
104 
105 	pr_info("parsing numa-distance-map-v1\n");
106 
107 	matrix = of_get_property(map, "distance-matrix", NULL);
108 	if (!matrix) {
109 		pr_err("No distance-matrix property in distance-map\n");
110 		return -EINVAL;
111 	}
112 
113 	entry_count = of_property_count_u32_elems(map, "distance-matrix");
114 	if (entry_count <= 0) {
115 		pr_err("Invalid distance-matrix\n");
116 		return -EINVAL;
117 	}
118 
119 	for (i = 0; i + 2 < entry_count; i += 3) {
120 		u32 nodea, nodeb, distance;
121 
122 		nodea = of_read_number(matrix, 1);
123 		matrix++;
124 		nodeb = of_read_number(matrix, 1);
125 		matrix++;
126 		distance = of_read_number(matrix, 1);
127 		matrix++;
128 
129 		numa_set_distance(nodea, nodeb, distance);
130 		pr_debug("distance[node%d -> node%d] = %d\n",
131 			 nodea, nodeb, distance);
132 
133 		/* Set default distance of node B->A same as A->B */
134 		if (nodeb > nodea)
135 			numa_set_distance(nodeb, nodea, distance);
136 	}
137 
138 	return 0;
139 }
140 
141 static int __init of_numa_parse_distance_map(void)
142 {
143 	int ret = 0;
144 	struct device_node *np;
145 
146 	np = of_find_compatible_node(NULL, NULL,
147 				     "numa-distance-map-v1");
148 	if (np)
149 		ret = of_numa_parse_distance_map_v1(np);
150 
151 	of_node_put(np);
152 	return ret;
153 }
154 
155 int of_node_to_nid(struct device_node *device)
156 {
157 	struct device_node *np;
158 	u32 nid;
159 	int r = -ENODATA;
160 
161 	np = of_node_get(device);
162 
163 	while (np) {
164 		r = of_property_read_u32(np, "numa-node-id", &nid);
165 		/*
166 		 * -EINVAL indicates the property was not found, and
167 		 *  we walk up the tree trying to find a parent with a
168 		 *  "numa-node-id".  Any other type of error indicates
169 		 *  a bad device tree and we give up.
170 		 */
171 		if (r != -EINVAL)
172 			break;
173 
174 		np = of_get_next_parent(np);
175 	}
176 	if (np && r)
177 		pr_warn("Invalid \"numa-node-id\" property in node %s\n",
178 			np->name);
179 	of_node_put(np);
180 
181 	/*
182 	 * If numa=off passed on command line, or with a defective
183 	 * device tree, the nid may not be in the set of possible
184 	 * nodes.  Check for this case and return NUMA_NO_NODE.
185 	 */
186 	if (!r && nid < MAX_NUMNODES && node_possible(nid))
187 		return nid;
188 
189 	return NUMA_NO_NODE;
190 }
191 EXPORT_SYMBOL(of_node_to_nid);
192 
193 int __init of_numa_init(void)
194 {
195 	int r;
196 
197 	of_numa_parse_cpu_nodes();
198 	r = of_numa_parse_memory_nodes();
199 	if (r)
200 		return r;
201 	return of_numa_parse_distance_map();
202 }
203