// SPDX-License-Identifier: GPL-2.0
/*
 * AMD NUMA support.
 * Discover the memory map and associated nodes.
 *
 * This version reads it directly from the AMD northbridge.
 *
 * Copyright 2002,2003 Andi Kleen, SuSE Labs.
 */
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/nodemask.h>
#include <linux/memblock.h>
#include <linux/numa_memblks.h>

#include <asm/io.h>
#include <linux/pci_ids.h>
#include <linux/acpi.h>
#include <asm/types.h>
#include <asm/mmzone.h>
#include <asm/proto.h>
#include <asm/e820/api.h>
#include <asm/pci-direct.h>
#include <asm/numa.h>
#include <asm/mpspec.h>
#include <asm/apic.h>
#include <asm/amd/nb.h>

static unsigned char __initdata nodeids[8];

static __init int find_northbridge(void)
{
        int num;

        for (num = 0; num < 32; num++) {
                u32 header;

                header = read_pci_config(0, num, 0, 0x00);
                if (header != (PCI_VENDOR_ID_AMD | (0x1100<<16)) &&
                        header != (PCI_VENDOR_ID_AMD | (0x1200<<16)) &&
                        header != (PCI_VENDOR_ID_AMD | (0x1300<<16)))
                        continue;

                header = read_pci_config(0, num, 1, 0x00);
                if (header != (PCI_VENDOR_ID_AMD | (0x1101<<16)) &&
                        header != (PCI_VENDOR_ID_AMD | (0x1201<<16)) &&
                        header != (PCI_VENDOR_ID_AMD | (0x1301<<16)))
                        continue;
                return num;
        }

        return -ENOENT;
}

int __init amd_numa_init(void)
{
        unsigned int numnodes, cores, apicid;
        u64 prevbase, start = PFN_PHYS(0);
        u64 end = PFN_PHYS(max_pfn);
        u32 nodeid, reg;
        int i, j, nb;

        if (!early_pci_allowed())
                return -EINVAL;

        nb = find_northbridge();
        if (nb < 0)
                return nb;

        pr_info("Scanning NUMA topology in Northbridge %d\n", nb);

        reg = read_pci_config(0, nb, 0, 0x60);
        numnodes = ((reg >> 4) & 0xF) + 1;
        if (numnodes <= 1)
                return -ENOENT;

        pr_info("Number of physical nodes %d\n", numnodes);

        prevbase = 0;
        for (i = 0; i < 8; i++) {
                u64 base, limit;

                base = read_pci_config(0, nb, 1, 0x40 + i*8);
                limit = read_pci_config(0, nb, 1, 0x44 + i*8);

                nodeids[i] = nodeid = limit & 7;
                if ((base & 3) == 0) {
                        if (i < numnodes)
                                pr_info("Skipping disabled node %d\n", i);
                        continue;
                }
                if (nodeid >= numnodes) {
                        pr_info("Ignoring excess node %d (%Lx:%Lx)\n", nodeid,
                                base, limit);
                        continue;
                }

                if (!limit) {
                        pr_info("Skipping node entry %d (base %Lx)\n",
                                i, base);
                        continue;
                }
                if ((base >> 8) & 3 || (limit >> 8) & 3) {
                        pr_err("Node %d using interleaving mode %Lx/%Lx\n",
                               nodeid, (base >> 8) & 3, (limit >> 8) & 3);
                        return -EINVAL;
                }
                if (node_isset(nodeid, numa_nodes_parsed)) {
                        pr_info("Node %d already present, skipping\n",
                                nodeid);
                        continue;
                }

                limit >>= 16;
                limit++;
                limit <<= 24;

                if (limit > end)
                        limit = end;
                if (limit <= base)
                        continue;

                base >>= 16;
                base <<= 24;

                if (base < start)
                        base = start;
                if (limit > end)
                        limit = end;
                if (limit == base) {
                        pr_err("Empty node %d\n", nodeid);
                        continue;
                }
                if (limit < base) {
                        pr_err("Node %d bogus settings %Lx-%Lx.\n",
                               nodeid, base, limit);
                        continue;
                }

                /* Could sort here, but pun for now. Should not happen anyroads. */
                if (prevbase > base) {
                        pr_err("Node map not sorted %Lx,%Lx\n",
                               prevbase, base);
                        return -EINVAL;
                }

                pr_info("Node %d MemBase %016Lx Limit %016Lx\n",
                        nodeid, base, limit);

                prevbase = base;
                numa_add_memblk(nodeid, base, limit);
                node_set(nodeid, numa_nodes_parsed);
        }

        if (nodes_empty(numa_nodes_parsed))
                return -ENOENT;

        /*
         * We seem to have valid NUMA configuration. Map apicids to nodes
         * using the size of the core domain in the APIC space.
         */
        cores = topology_get_domain_size(TOPO_CORE_DOMAIN);

        apicid = boot_cpu_physical_apicid;
        if (apicid > 0)
                pr_info("BSP APIC ID: %02x\n", apicid);

        for_each_node_mask(i, numa_nodes_parsed) {
                for (j = 0; j < cores; j++, apicid++)
                        set_apicid_to_node(apicid, i);
        }
        return 0;
}