linux/drivers/of/of_numa.c
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   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}
 180
 181int __init of_numa_init(void)
 182{
 183        int r;
 184
 185        of_numa_parse_cpu_nodes();
 186        r = of_numa_parse_memory_nodes();
 187        if (r)
 188                return r;
 189        return of_numa_parse_distance_map();
 190}
 191