/*
 * OF NUMA Parsing support.
 *
 * Copyright (C) 2015 - 2016 Cavium Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#define pr_fmt(fmt) "OF: NUMA: " fmt

#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/nodemask.h>

#include <asm/numa.h>

/* define default numa node to 0 */
#define DEFAULT_NODE 0

/*
 * Even though we connect cpus to numa domains later in SMP
 * init, we need to know the node ids now for all cpus.
*/
static void __init of_numa_parse_cpu_nodes(void)
{
        u32 nid;
        int r;
        struct device_node *cpus;
        struct device_node *np = NULL;

        cpus = of_find_node_by_path("/cpus");
        if (!cpus)
                return;

        for_each_child_of_node(cpus, np) {
                /* Skip things that are not CPUs */
                if (of_node_cmp(np->type, "cpu") != 0)
                        continue;

                r = of_property_read_u32(np, "numa-node-id", &nid);
                if (r)
                        continue;

                pr_debug("CPU on %u\n", nid);
                if (nid >= MAX_NUMNODES)
                        pr_warn("Node id %u exceeds maximum value\n", nid);
                else
                        node_set(nid, numa_nodes_parsed);
        }
}

static int __init of_numa_parse_memory_nodes(void)
{
        struct device_node *np = NULL;
        struct resource rsrc;
        u32 nid;
        int i, r;

        for_each_node_by_type(np, "memory") {
                r = of_property_read_u32(np, "numa-node-id", &nid);
                if (r == -EINVAL)
                        /*
                         * property doesn't exist if -EINVAL, continue
                         * looking for more memory nodes with
                         * "numa-node-id" property
                         */
                        continue;

                if (nid >= MAX_NUMNODES) {
                        pr_warn("Node id %u exceeds maximum value\n", nid);
                        r = -EINVAL;
                }

                for (i = 0; !r && !of_address_to_resource(np, i, &rsrc); i++)
                        r = numa_add_memblk(nid, rsrc.start, rsrc.end + 1);

                if (!i || r) {
                        of_node_put(np);
                        pr_err("bad property in memory node\n");
                        return r ? : -EINVAL;
                }
        }

        return 0;
}

static int __init of_numa_parse_distance_map_v1(struct device_node *map)
{
        const __be32 *matrix;
        int entry_count;
        int i;

        pr_info("parsing numa-distance-map-v1\n");

        matrix = of_get_property(map, "distance-matrix", NULL);
        if (!matrix) {
                pr_err("No distance-matrix property in distance-map\n");
                return -EINVAL;
        }

        entry_count = of_property_count_u32_elems(map, "distance-matrix");
        if (entry_count <= 0) {
                pr_err("Invalid distance-matrix\n");
                return -EINVAL;
        }

        for (i = 0; i + 2 < entry_count; i += 3) {
                u32 nodea, nodeb, distance;

                nodea = of_read_number(matrix, 1);
                matrix++;
                nodeb = of_read_number(matrix, 1);
                matrix++;
                distance = of_read_number(matrix, 1);
                matrix++;

                numa_set_distance(nodea, nodeb, distance);
                pr_debug("distance[node%d -> node%d] = %d\n",
                         nodea, nodeb, distance);

                /* Set default distance of node B->A same as A->B */
                if (nodeb > nodea)
                        numa_set_distance(nodeb, nodea, distance);
        }

        return 0;
}

static int __init of_numa_parse_distance_map(void)
{
        int ret = 0;
        struct device_node *np;

        np = of_find_compatible_node(NULL, NULL,
                                     "numa-distance-map-v1");
        if (np)
                ret = of_numa_parse_distance_map_v1(np);

        of_node_put(np);
        return ret;
}

int of_node_to_nid(struct device_node *device)
{
        struct device_node *np;
        u32 nid;
        int r = -ENODATA;

        np = of_node_get(device);

        while (np) {
                r = of_property_read_u32(np, "numa-node-id", &nid);
                /*
                 * -EINVAL indicates the property was not found, and
                 *  we walk up the tree trying to find a parent with a
                 *  "numa-node-id".  Any other type of error indicates
                 *  a bad device tree and we give up.
                 */
                if (r != -EINVAL)
                        break;

                np = of_get_next_parent(np);
        }
        if (np && r)
                pr_warn("Invalid \"numa-node-id\" property in node %s\n",
                        np->name);
        of_node_put(np);

        if (!r)
                return nid;

        return NUMA_NO_NODE;
}
EXPORT_SYMBOL(of_node_to_nid);

int __init of_numa_init(void)
{
        int r;

        of_numa_parse_cpu_nodes();
        r = of_numa_parse_memory_nodes();
        if (r)
                return r;
        return of_numa_parse_distance_map();
}