xref: /linux/drivers/of/of_numa.c (revision 9cc8d0ecdd2aad42e377e971e3bb114339df609e)
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 #include <linux/numa_memblks.h>
14 
15 #include <asm/numa.h>
16 
17 /*
18  * Even though we connect cpus to numa domains later in SMP
19  * init, we need to know the node ids now for all cpus.
20 */
21 static void __init of_numa_parse_cpu_nodes(void)
22 {
23 	u32 nid;
24 	int r;
25 	struct device_node *np;
26 
27 	for_each_of_cpu_node(np) {
28 		r = of_property_read_u32(np, "numa-node-id", &nid);
29 		if (r)
30 			continue;
31 
32 		pr_debug("CPU on %u\n", nid);
33 		if (nid >= MAX_NUMNODES)
34 			pr_warn("Node id %u exceeds maximum value\n", nid);
35 		else
36 			node_set(nid, numa_nodes_parsed);
37 	}
38 }
39 
40 static int __init of_numa_parse_memory_nodes(void)
41 {
42 	struct device_node *np = NULL;
43 	struct resource rsrc;
44 	u32 nid;
45 	int i, r = -EINVAL;
46 
47 	for_each_node_by_type(np, "memory") {
48 		r = of_property_read_u32(np, "numa-node-id", &nid);
49 		if (r == -EINVAL)
50 			/*
51 			 * property doesn't exist if -EINVAL, continue
52 			 * looking for more memory nodes with
53 			 * "numa-node-id" property
54 			 */
55 			continue;
56 
57 		if (nid >= MAX_NUMNODES) {
58 			pr_warn("Node id %u exceeds maximum value\n", nid);
59 			r = -EINVAL;
60 		}
61 
62 		for (i = 0; !r && !of_address_to_resource(np, i, &rsrc); i++)
63 			r = numa_add_memblk(nid, rsrc.start, rsrc.end + 1);
64 
65 		if (!i || r) {
66 			of_node_put(np);
67 			pr_err("bad property in memory node\n");
68 			return r ? : -EINVAL;
69 		}
70 	}
71 
72 	return r;
73 }
74 
75 static int __init of_numa_parse_distance_map_v1(struct device_node *map)
76 {
77 	const __be32 *matrix;
78 	int entry_count;
79 	int i;
80 
81 	pr_info("parsing numa-distance-map-v1\n");
82 
83 	matrix = of_get_property(map, "distance-matrix", NULL);
84 	if (!matrix) {
85 		pr_err("No distance-matrix property in distance-map\n");
86 		return -EINVAL;
87 	}
88 
89 	entry_count = of_property_count_u32_elems(map, "distance-matrix");
90 	if (entry_count <= 0) {
91 		pr_err("Invalid distance-matrix\n");
92 		return -EINVAL;
93 	}
94 
95 	for (i = 0; i + 2 < entry_count; i += 3) {
96 		u32 nodea, nodeb, distance;
97 
98 		nodea = of_read_number(matrix, 1);
99 		matrix++;
100 		nodeb = of_read_number(matrix, 1);
101 		matrix++;
102 		distance = of_read_number(matrix, 1);
103 		matrix++;
104 
105 		if ((nodea == nodeb && distance != LOCAL_DISTANCE) ||
106 		    (nodea != nodeb && distance <= LOCAL_DISTANCE)) {
107 			pr_err("Invalid distance[node%d -> node%d] = %d\n",
108 			       nodea, nodeb, distance);
109 			return -EINVAL;
110 		}
111 
112 		node_set(nodea, numa_nodes_parsed);
113 
114 		numa_set_distance(nodea, nodeb, distance);
115 
116 		/* Set default distance of node B->A same as A->B */
117 		if (nodeb > nodea)
118 			numa_set_distance(nodeb, nodea, distance);
119 	}
120 
121 	return 0;
122 }
123 
124 static int __init of_numa_parse_distance_map(void)
125 {
126 	int ret = 0;
127 	struct device_node *np;
128 
129 	np = of_find_compatible_node(NULL, NULL,
130 				     "numa-distance-map-v1");
131 	if (np)
132 		ret = of_numa_parse_distance_map_v1(np);
133 
134 	of_node_put(np);
135 	return ret;
136 }
137 
138 int of_node_to_nid(struct device_node *device)
139 {
140 	struct device_node *np;
141 	u32 nid;
142 	int r = -ENODATA;
143 
144 	np = of_node_get(device);
145 
146 	while (np) {
147 		r = of_property_read_u32(np, "numa-node-id", &nid);
148 		/*
149 		 * -EINVAL indicates the property was not found, and
150 		 *  we walk up the tree trying to find a parent with a
151 		 *  "numa-node-id".  Any other type of error indicates
152 		 *  a bad device tree and we give up.
153 		 */
154 		if (r != -EINVAL)
155 			break;
156 
157 		np = of_get_next_parent(np);
158 	}
159 	if (np && r)
160 		pr_warn("Invalid \"numa-node-id\" property in node %pOFn\n",
161 			np);
162 	of_node_put(np);
163 
164 	/*
165 	 * If numa=off passed on command line, or with a defective
166 	 * device tree, the nid may not be in the set of possible
167 	 * nodes.  Check for this case and return NUMA_NO_NODE.
168 	 */
169 	if (!r && nid < MAX_NUMNODES && node_possible(nid))
170 		return nid;
171 
172 	return NUMA_NO_NODE;
173 }
174 
175 int __init of_numa_init(void)
176 {
177 	int r;
178 
179 	of_numa_parse_cpu_nodes();
180 	r = of_numa_parse_memory_nodes();
181 	if (r)
182 		return r;
183 	return of_numa_parse_distance_map();
184 }
185