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*/
 23static 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
 53static 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
 88static 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
130static 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
144int 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}
180EXPORT_SYMBOL(of_node_to_nid);
181
182int __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}