xref: /openbmc/linux/drivers/of/of_numa.c (revision 01a6e126)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * OF NUMA Parsing support.
4  *
5  * Copyright (C) 2015 - 2016 Cavium Inc.
6  */
7 
8 #define pr_fmt(fmt) "OF: NUMA: " fmt
9 
10 #include <linux/of.h>
11 #include <linux/of_address.h>
12 #include <linux/nodemask.h>
13 
14 #include <asm/numa.h>
15 
16 /* define default numa node to 0 */
17 #define DEFAULT_NODE 0
18 
19 /*
20  * Even though we connect cpus to numa domains later in SMP
21  * init, we need to know the node ids now for all cpus.
22 */
23 static void __init of_numa_parse_cpu_nodes(void)
24 {
25 	u32 nid;
26 	int r;
27 	struct device_node *cpus;
28 	struct device_node *np = NULL;
29 
30 	cpus = of_find_node_by_path("/cpus");
31 	if (!cpus)
32 		return;
33 
34 	for_each_child_of_node(cpus, np) {
35 		/* Skip things that are not CPUs */
36 		if (of_node_cmp(np->type, "cpu") != 0)
37 			continue;
38 
39 		r = of_property_read_u32(np, "numa-node-id", &nid);
40 		if (r)
41 			continue;
42 
43 		pr_debug("CPU on %u\n", nid);
44 		if (nid >= MAX_NUMNODES)
45 			pr_warn("Node id %u exceeds maximum value\n", nid);
46 		else
47 			node_set(nid, numa_nodes_parsed);
48 	}
49 
50 	of_node_put(cpus);
51 }
52 
53 static int __init of_numa_parse_memory_nodes(void)
54 {
55 	struct device_node *np = NULL;
56 	struct resource rsrc;
57 	u32 nid;
58 	int i, r;
59 
60 	for_each_node_by_type(np, "memory") {
61 		r = of_property_read_u32(np, "numa-node-id", &nid);
62 		if (r == -EINVAL)
63 			/*
64 			 * property doesn't exist if -EINVAL, continue
65 			 * looking for more memory nodes with
66 			 * "numa-node-id" property
67 			 */
68 			continue;
69 
70 		if (nid >= MAX_NUMNODES) {
71 			pr_warn("Node id %u exceeds maximum value\n", nid);
72 			r = -EINVAL;
73 		}
74 
75 		for (i = 0; !r && !of_address_to_resource(np, i, &rsrc); i++)
76 			r = numa_add_memblk(nid, rsrc.start, rsrc.end + 1);
77 
78 		if (!i || r) {
79 			of_node_put(np);
80 			pr_err("bad property in memory node\n");
81 			return r ? : -EINVAL;
82 		}
83 	}
84 
85 	return 0;
86 }
87 
88 static int __init of_numa_parse_distance_map_v1(struct device_node *map)
89 {
90 	const __be32 *matrix;
91 	int entry_count;
92 	int i;
93 
94 	pr_info("parsing numa-distance-map-v1\n");
95 
96 	matrix = of_get_property(map, "distance-matrix", NULL);
97 	if (!matrix) {
98 		pr_err("No distance-matrix property in distance-map\n");
99 		return -EINVAL;
100 	}
101 
102 	entry_count = of_property_count_u32_elems(map, "distance-matrix");
103 	if (entry_count <= 0) {
104 		pr_err("Invalid distance-matrix\n");
105 		return -EINVAL;
106 	}
107 
108 	for (i = 0; i + 2 < entry_count; i += 3) {
109 		u32 nodea, nodeb, distance;
110 
111 		nodea = of_read_number(matrix, 1);
112 		matrix++;
113 		nodeb = of_read_number(matrix, 1);
114 		matrix++;
115 		distance = of_read_number(matrix, 1);
116 		matrix++;
117 
118 		numa_set_distance(nodea, nodeb, distance);
119 		pr_debug("distance[node%d -> node%d] = %d\n",
120 			 nodea, nodeb, distance);
121 
122 		/* Set default distance of node B->A same as A->B */
123 		if (nodeb > nodea)
124 			numa_set_distance(nodeb, nodea, distance);
125 	}
126 
127 	return 0;
128 }
129 
130 static int __init of_numa_parse_distance_map(void)
131 {
132 	int ret = 0;
133 	struct device_node *np;
134 
135 	np = of_find_compatible_node(NULL, NULL,
136 				     "numa-distance-map-v1");
137 	if (np)
138 		ret = of_numa_parse_distance_map_v1(np);
139 
140 	of_node_put(np);
141 	return ret;
142 }
143 
144 int of_node_to_nid(struct device_node *device)
145 {
146 	struct device_node *np;
147 	u32 nid;
148 	int r = -ENODATA;
149 
150 	np = of_node_get(device);
151 
152 	while (np) {
153 		r = of_property_read_u32(np, "numa-node-id", &nid);
154 		/*
155 		 * -EINVAL indicates the property was not found, and
156 		 *  we walk up the tree trying to find a parent with a
157 		 *  "numa-node-id".  Any other type of error indicates
158 		 *  a bad device tree and we give up.
159 		 */
160 		if (r != -EINVAL)
161 			break;
162 
163 		np = of_get_next_parent(np);
164 	}
165 	if (np && r)
166 		pr_warn("Invalid \"numa-node-id\" property in node %s\n",
167 			np->name);
168 	of_node_put(np);
169 
170 	/*
171 	 * If numa=off passed on command line, or with a defective
172 	 * device tree, the nid may not be in the set of possible
173 	 * nodes.  Check for this case and return NUMA_NO_NODE.
174 	 */
175 	if (!r && nid < MAX_NUMNODES && node_possible(nid))
176 		return nid;
177 
178 	return NUMA_NO_NODE;
179 }
180 EXPORT_SYMBOL(of_node_to_nid);
181 
182 int __init of_numa_init(void)
183 {
184 	int r;
185 
186 	of_numa_parse_cpu_nodes();
187 	r = of_numa_parse_memory_nodes();
188 	if (r)
189 		return r;
190 	return of_numa_parse_distance_map();
191 }
192