drivers/of/of_numa.c

   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 }