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 */
of_numa_parse_cpu_nodes(void)23 static void __init of_numa_parse_cpu_nodes(void)
24 {
25 	u32 nid;
26 	int r;
27 	struct device_node *np;
28 
29 	for_each_of_cpu_node(np) {
30 		r = of_property_read_u32(np, "numa-node-id", &nid);
31 		if (r)
32 			continue;
33 
34 		pr_debug("CPU on %u\n", nid);
35 		if (nid >= MAX_NUMNODES)
36 			pr_warn("Node id %u exceeds maximum value\n", nid);
37 		else
38 			node_set(nid, numa_nodes_parsed);
39 	}
40 }
41 
of_numa_parse_memory_nodes(void)42 static int __init of_numa_parse_memory_nodes(void)
43 {
44 	struct device_node *np = NULL;
45 	struct resource rsrc;
46 	u32 nid;
47 	int i, r;
48 
49 	for_each_node_by_type(np, "memory") {
50 		r = of_property_read_u32(np, "numa-node-id", &nid);
51 		if (r == -EINVAL)
52 			/*
53 			 * property doesn't exist if -EINVAL, continue
54 			 * looking for more memory nodes with
55 			 * "numa-node-id" property
56 			 */
57 			continue;
58 
59 		if (nid >= MAX_NUMNODES) {
60 			pr_warn("Node id %u exceeds maximum value\n", nid);
61 			r = -EINVAL;
62 		}
63 
64 		for (i = 0; !r && !of_address_to_resource(np, i, &rsrc); i++)
65 			r = numa_add_memblk(nid, rsrc.start, rsrc.end + 1);
66 
67 		if (!i || r) {
68 			of_node_put(np);
69 			pr_err("bad property in memory node\n");
70 			return r ? : -EINVAL;
71 		}
72 	}
73 
74 	return 0;
75 }
76 
of_numa_parse_distance_map_v1(struct device_node * map)77 static int __init of_numa_parse_distance_map_v1(struct device_node *map)
78 {
79 	const __be32 *matrix;
80 	int entry_count;
81 	int i;
82 
83 	pr_info("parsing numa-distance-map-v1\n");
84 
85 	matrix = of_get_property(map, "distance-matrix", NULL);
86 	if (!matrix) {
87 		pr_err("No distance-matrix property in distance-map\n");
88 		return -EINVAL;
89 	}
90 
91 	entry_count = of_property_count_u32_elems(map, "distance-matrix");
92 	if (entry_count <= 0) {
93 		pr_err("Invalid distance-matrix\n");
94 		return -EINVAL;
95 	}
96 
97 	for (i = 0; i + 2 < entry_count; i += 3) {
98 		u32 nodea, nodeb, distance;
99 
100 		nodea = of_read_number(matrix, 1);
101 		matrix++;
102 		nodeb = of_read_number(matrix, 1);
103 		matrix++;
104 		distance = of_read_number(matrix, 1);
105 		matrix++;
106 
107 		if ((nodea == nodeb && distance != LOCAL_DISTANCE) ||
108 		    (nodea != nodeb && distance <= LOCAL_DISTANCE)) {
109 			pr_err("Invalid distance[node%d -> node%d] = %d\n",
110 			       nodea, nodeb, distance);
111 			return -EINVAL;
112 		}
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 
of_numa_parse_distance_map(void)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 
of_node_to_nid(struct device_node * device)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 
of_numa_init(void)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