xref: /linux/drivers/of/of_numa.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
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 
62 static int __init of_numa_parse_memory_nodes(void)
63 {
64 	struct device_node *np = NULL;
65 	struct resource rsrc;
66 	u32 nid;
67 	int i, r;
68 
69 	for_each_node_by_type(np, "memory") {
70 		r = of_property_read_u32(np, "numa-node-id", &nid);
71 		if (r == -EINVAL)
72 			/*
73 			 * property doesn't exist if -EINVAL, continue
74 			 * looking for more memory nodes with
75 			 * "numa-node-id" property
76 			 */
77 			continue;
78 
79 		if (nid >= MAX_NUMNODES) {
80 			pr_warn("Node id %u exceeds maximum value\n", nid);
81 			r = -EINVAL;
82 		}
83 
84 		for (i = 0; !r && !of_address_to_resource(np, i, &rsrc); i++)
85 			r = numa_add_memblk(nid, rsrc.start, rsrc.end + 1);
86 
87 		if (!i || r) {
88 			of_node_put(np);
89 			pr_err("bad property in memory node\n");
90 			return r ? : -EINVAL;
91 		}
92 	}
93 
94 	return 0;
95 }
96 
97 static int __init of_numa_parse_distance_map_v1(struct device_node *map)
98 {
99 	const __be32 *matrix;
100 	int entry_count;
101 	int i;
102 
103 	pr_info("parsing numa-distance-map-v1\n");
104 
105 	matrix = of_get_property(map, "distance-matrix", NULL);
106 	if (!matrix) {
107 		pr_err("No distance-matrix property in distance-map\n");
108 		return -EINVAL;
109 	}
110 
111 	entry_count = of_property_count_u32_elems(map, "distance-matrix");
112 	if (entry_count <= 0) {
113 		pr_err("Invalid distance-matrix\n");
114 		return -EINVAL;
115 	}
116 
117 	for (i = 0; i + 2 < entry_count; i += 3) {
118 		u32 nodea, nodeb, distance;
119 
120 		nodea = of_read_number(matrix, 1);
121 		matrix++;
122 		nodeb = of_read_number(matrix, 1);
123 		matrix++;
124 		distance = of_read_number(matrix, 1);
125 		matrix++;
126 
127 		numa_set_distance(nodea, nodeb, distance);
128 		pr_debug("distance[node%d -> node%d] = %d\n",
129 			 nodea, nodeb, distance);
130 
131 		/* Set default distance of node B->A same as A->B */
132 		if (nodeb > nodea)
133 			numa_set_distance(nodeb, nodea, distance);
134 	}
135 
136 	return 0;
137 }
138 
139 static int __init of_numa_parse_distance_map(void)
140 {
141 	int ret = 0;
142 	struct device_node *np;
143 
144 	np = of_find_compatible_node(NULL, NULL,
145 				     "numa-distance-map-v1");
146 	if (np)
147 		ret = of_numa_parse_distance_map_v1(np);
148 
149 	of_node_put(np);
150 	return ret;
151 }
152 
153 int of_node_to_nid(struct device_node *device)
154 {
155 	struct device_node *np;
156 	u32 nid;
157 	int r = -ENODATA;
158 
159 	np = of_node_get(device);
160 
161 	while (np) {
162 		r = of_property_read_u32(np, "numa-node-id", &nid);
163 		/*
164 		 * -EINVAL indicates the property was not found, and
165 		 *  we walk up the tree trying to find a parent with a
166 		 *  "numa-node-id".  Any other type of error indicates
167 		 *  a bad device tree and we give up.
168 		 */
169 		if (r != -EINVAL)
170 			break;
171 
172 		np = of_get_next_parent(np);
173 	}
174 	if (np && r)
175 		pr_warn("Invalid \"numa-node-id\" property in node %s\n",
176 			np->name);
177 	of_node_put(np);
178 
179 	/*
180 	 * If numa=off passed on command line, or with a defective
181 	 * device tree, the nid may not be in the set of possible
182 	 * nodes.  Check for this case and return NUMA_NO_NODE.
183 	 */
184 	if (!r && nid < MAX_NUMNODES && node_possible(nid))
185 		return nid;
186 
187 	return NUMA_NO_NODE;
188 }
189 EXPORT_SYMBOL(of_node_to_nid);
190 
191 int __init of_numa_init(void)
192 {
193 	int r;
194 
195 	of_numa_parse_cpu_nodes();
196 	r = of_numa_parse_memory_nodes();
197 	if (r)
198 		return r;
199 	return of_numa_parse_distance_map();
200 }
201