// SPDX-License-Identifier: GPL-2.0-only
/* Common code for 32 and 64-bit NUMA */
#include <linux/acpi.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/of.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/memblock.h>
#include <linux/mmzone.h>
#include <linux/ctype.h>
#include <linux/nodemask.h>
#include <linux/sched.h>
#include <linux/topology.h>
#include <linux/sort.h>
#include <linux/numa_memblks.h>

#include <asm/e820/api.h>
#include <asm/proto.h>
#include <asm/dma.h>
#include <asm/numa.h>
#include <asm/amd/nb.h>

#include "mm_internal.h"

int numa_off;

static __init int numa_setup(char *opt)
{
        if (!opt)
                return -EINVAL;
        if (!strncmp(opt, "off", 3))
                numa_off = 1;
        if (!strncmp(opt, "fake=", 5))
                return numa_emu_cmdline(opt + 5);
        if (!strncmp(opt, "noacpi", 6))
                disable_srat();
        if (!strncmp(opt, "nohmat", 6))
                disable_hmat();
        return 0;
}
early_param("numa", numa_setup);

/*
 * apicid, cpu, node mappings
 */
s16 __apicid_to_node[MAX_LOCAL_APIC] = {
        [0 ... MAX_LOCAL_APIC-1] = NUMA_NO_NODE
};

nodemask_t numa_phys_nodes_parsed __initdata;

int numa_cpu_node(int cpu)
{
        u32 apicid = early_per_cpu(x86_cpu_to_apicid, cpu);

        if (apicid != BAD_APICID)
                return __apicid_to_node[apicid];
        return NUMA_NO_NODE;
}

int __init num_phys_nodes(void)
{
        return bitmap_weight(numa_phys_nodes_parsed.bits, MAX_NUMNODES);
}

cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
EXPORT_SYMBOL(node_to_cpumask_map);

/*
 * Map cpu index to node index
 */
DEFINE_EARLY_PER_CPU(int, x86_cpu_to_node_map, NUMA_NO_NODE);
EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_node_map);

void numa_set_node(int cpu, int node)
{
        int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map);

        /* early setting, no percpu area yet */
        if (cpu_to_node_map) {
                cpu_to_node_map[cpu] = node;
                return;
        }

#ifdef CONFIG_DEBUG_PER_CPU_MAPS
        if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) {
                printk(KERN_ERR "numa_set_node: invalid cpu# (%d)\n", cpu);
                dump_stack();
                return;
        }
#endif
        per_cpu(x86_cpu_to_node_map, cpu) = node;

        set_cpu_numa_node(cpu, node);
}

void numa_clear_node(int cpu)
{
        numa_set_node(cpu, NUMA_NO_NODE);
}

/*
 * Allocate node_to_cpumask_map based on number of available nodes
 * Requires node_possible_map to be valid.
 *
 * Note: cpumask_of_node() is not valid until after this is done.
 * (Use CONFIG_DEBUG_PER_CPU_MAPS to check this.)
 */
void __init setup_node_to_cpumask_map(void)
{
        unsigned int node;

        /* setup nr_node_ids if not done yet */
        if (nr_node_ids == MAX_NUMNODES)
                setup_nr_node_ids();

        /* allocate the map */
        for (node = 0; node < nr_node_ids; node++)
                alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);

        /* cpumask_of_node() will now work */
        pr_debug("Node to cpumask map for %u nodes\n", nr_node_ids);
}

static int __init numa_register_nodes(void)
{
        int nid;

        if (!memblock_validate_numa_coverage(SZ_1M))
                return -EINVAL;

        /* Finally register nodes. */
        for_each_node_mask(nid, node_possible_map) {
                unsigned long start_pfn, end_pfn;

                /*
                 * Note, get_pfn_range_for_nid() depends on
                 * memblock_set_node() having already happened
                 */
                get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
                if (start_pfn >= end_pfn)
                        continue;

                alloc_node_data(nid);
                node_set_online(nid);
        }

        /* Dump memblock with node info and return. */
        memblock_dump_all();
        return 0;
}

/*
 * There are unfortunately some poorly designed mainboards around that
 * only connect memory to a single CPU. This breaks the 1:1 cpu->node
 * mapping. To avoid this fill in the mapping for all possible CPUs,
 * as the number of CPUs is not known yet. We round robin the existing
 * nodes.
 */
static void __init numa_init_array(void)
{
        int rr, i;

        rr = first_node(node_online_map);
        for (i = 0; i < nr_cpu_ids; i++) {
                if (early_cpu_to_node(i) != NUMA_NO_NODE)
                        continue;
                numa_set_node(i, rr);
                rr = next_node_in(rr, node_online_map);
        }
}

static int __init numa_init(int (*init_func)(void))
{
        int i;
        int ret;

        for (i = 0; i < MAX_LOCAL_APIC; i++)
                set_apicid_to_node(i, NUMA_NO_NODE);

        ret = numa_memblks_init(init_func, /* memblock_force_top_down */ true);
        if (ret < 0)
                return ret;

        ret = numa_register_nodes();
        if (ret < 0)
                return ret;

        for (i = 0; i < nr_cpu_ids; i++) {
                int nid = early_cpu_to_node(i);

                if (nid == NUMA_NO_NODE)
                        continue;
                if (!node_online(nid))
                        numa_clear_node(i);
        }
        numa_init_array();

        return 0;
}

/**
 * dummy_numa_init - Fallback dummy NUMA init
 *
 * Used if there's no underlying NUMA architecture, NUMA initialization
 * fails, or NUMA is disabled on the command line.
 *
 * Must online at least one node and add memory blocks that cover all
 * allowed memory.  This function must not fail.
 */
static int __init dummy_numa_init(void)
{
        printk(KERN_INFO "%s\n",
               numa_off ? "NUMA turned off" : "No NUMA configuration found");
        printk(KERN_INFO "Faking a node at [mem %#018Lx-%#018Lx]\n",
               0LLU, PFN_PHYS(max_pfn) - 1);

        node_set(0, numa_nodes_parsed);
        node_set(0, numa_phys_nodes_parsed);
        numa_add_memblk(0, 0, PFN_PHYS(max_pfn));

        return 0;
}

/**
 * x86_numa_init - Initialize NUMA
 *
 * Try each configured NUMA initialization method until one succeeds.  The
 * last fallback is dummy single node config encompassing whole memory and
 * never fails.
 */
void __init x86_numa_init(void)
{
        if (!numa_off) {
#ifdef CONFIG_ACPI_NUMA
                if (!numa_init(x86_acpi_numa_init))
                        return;
#endif
#ifdef CONFIG_AMD_NUMA
                if (!numa_init(amd_numa_init))
                        return;
#endif
                if (acpi_disabled && !numa_init(of_numa_init))
                        return;
        }

        numa_init(dummy_numa_init);
}


/*
 * A node may exist which has one or more Generic Initiators but no CPUs and no
 * memory.
 *
 * This function must be called after init_cpu_to_node(), to ensure that any
 * memoryless CPU nodes have already been brought online, and before the
 * node_data[nid] is needed for zone list setup in build_all_zonelists().
 *
 * When this function is called, any nodes containing either memory and/or CPUs
 * will already be online and there is no need to do anything extra, even if
 * they also contain one or more Generic Initiators.
 */
void __init init_gi_nodes(void)
{
        int nid;

        /*
         * Exclude this node from
         * bringup_nonboot_cpus
         *  cpu_up
         *   __try_online_node
         *    register_node
         * because node_subsys is not initialized yet.
         * TODO remove dependency on node_online
         */
        for_each_node_state(nid, N_GENERIC_INITIATOR)
                if (!node_online(nid))
                        node_set_online(nid);
}

/*
 * Setup early cpu_to_node.
 *
 * Populate cpu_to_node[] only if x86_cpu_to_apicid[],
 * and apicid_to_node[] tables have valid entries for a CPU.
 * This means we skip cpu_to_node[] initialisation for NUMA
 * emulation and faking node case (when running a kernel compiled
 * for NUMA on a non NUMA box), which is OK as cpu_to_node[]
 * is already initialized in a round robin manner at numa_init_array,
 * prior to this call, and this initialization is good enough
 * for the fake NUMA cases.
 *
 * Called before the per_cpu areas are setup.
 */
void __init init_cpu_to_node(void)
{
        int cpu;
        u32 *cpu_to_apicid = early_per_cpu_ptr(x86_cpu_to_apicid);

        BUG_ON(cpu_to_apicid == NULL);

        for_each_possible_cpu(cpu) {
                int node = numa_cpu_node(cpu);

                if (node == NUMA_NO_NODE)
                        continue;

                /*
                 * Exclude this node from
                 * bringup_nonboot_cpus
                 *  cpu_up
                 *   __try_online_node
                 *    register_node
                 * because node_subsys is not initialized yet.
                 * TODO remove dependency on node_online
                 */
                if (!node_online(node))
                        node_set_online(node);

                numa_set_node(cpu, node);
        }
}

#ifndef CONFIG_DEBUG_PER_CPU_MAPS

# ifndef CONFIG_NUMA_EMU
void numa_add_cpu(unsigned int cpu)
{
        cpumask_set_cpu(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
}

void numa_remove_cpu(unsigned int cpu)
{
        cpumask_clear_cpu(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
}
# endif /* !CONFIG_NUMA_EMU */

#else   /* !CONFIG_DEBUG_PER_CPU_MAPS */

int __cpu_to_node(int cpu)
{
        if (early_per_cpu_ptr(x86_cpu_to_node_map)) {
                printk(KERN_WARNING
                        "cpu_to_node(%d): usage too early!\n", cpu);
                dump_stack();
                return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
        }
        return per_cpu(x86_cpu_to_node_map, cpu);
}
EXPORT_SYMBOL(__cpu_to_node);

/*
 * Same function as cpu_to_node() but used if called before the
 * per_cpu areas are setup.
 */
int early_cpu_to_node(int cpu)
{
        if (early_per_cpu_ptr(x86_cpu_to_node_map))
                return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];

        if (!cpu_possible(cpu)) {
                printk(KERN_WARNING
                        "early_cpu_to_node(%d): no per_cpu area!\n", cpu);
                dump_stack();
                return NUMA_NO_NODE;
        }
        return per_cpu(x86_cpu_to_node_map, cpu);
}

void debug_cpumask_set_cpu(unsigned int cpu, int node, bool enable)
{
        struct cpumask *mask;

        if (node == NUMA_NO_NODE) {
                /* early_cpu_to_node() already emits a warning and trace */
                return;
        }
        mask = node_to_cpumask_map[node];
        if (!cpumask_available(mask)) {
                pr_err("node_to_cpumask_map[%i] NULL\n", node);
                dump_stack();
                return;
        }

        if (enable)
                cpumask_set_cpu(cpu, mask);
        else
                cpumask_clear_cpu(cpu, mask);

        printk(KERN_DEBUG "%s cpu %d node %d: mask now %*pbl\n",
                enable ? "numa_add_cpu" : "numa_remove_cpu",
                cpu, node, cpumask_pr_args(mask));
        return;
}

# ifndef CONFIG_NUMA_EMU
static void numa_set_cpumask(int cpu, bool enable)
{
        debug_cpumask_set_cpu(cpu, early_cpu_to_node(cpu), enable);
}

void numa_add_cpu(unsigned int cpu)
{
        numa_set_cpumask(cpu, true);
}

void numa_remove_cpu(unsigned int cpu)
{
        numa_set_cpumask(cpu, false);
}
# endif /* !CONFIG_NUMA_EMU */

/*
 * Returns a pointer to the bitmask of CPUs on Node 'node'.
 */
const struct cpumask *cpumask_of_node(int node)
{
        if ((unsigned)node >= nr_node_ids) {
                printk(KERN_WARNING
                        "cpumask_of_node(%d): (unsigned)node >= nr_node_ids(%u)\n",
                        node, nr_node_ids);
                dump_stack();
                return cpu_none_mask;
        }
        if (!cpumask_available(node_to_cpumask_map[node])) {
                printk(KERN_WARNING
                        "cpumask_of_node(%d): no node_to_cpumask_map!\n",
                        node);
                dump_stack();
                return cpu_online_mask;
        }
        return node_to_cpumask_map[node];
}
EXPORT_SYMBOL(cpumask_of_node);

#endif  /* !CONFIG_DEBUG_PER_CPU_MAPS */

#ifdef CONFIG_NUMA_EMU
void __init numa_emu_update_cpu_to_node(int *emu_nid_to_phys,
                                        unsigned int nr_emu_nids)
{
        int i, j;

        /*
         * Transform __apicid_to_node table to use emulated nids by
         * reverse-mapping phys_nid.  The maps should always exist but fall
         * back to zero just in case.
         */
        for (i = 0; i < ARRAY_SIZE(__apicid_to_node); i++) {
                if (__apicid_to_node[i] == NUMA_NO_NODE)
                        continue;
                for (j = 0; j < nr_emu_nids; j++)
                        if (__apicid_to_node[i] == emu_nid_to_phys[j])
                                break;
                __apicid_to_node[i] = j < nr_emu_nids ? j : 0;
        }
}

u64 __init numa_emu_dma_end(void)
{
        return PFN_PHYS(MAX_DMA32_PFN);
}
#endif /* CONFIG_NUMA_EMU */