/*
 * AMD K8 NUMA support.
 * Discover the memory map and associated nodes.
 *
 * This version reads it directly from the K8 northbridge.
 *
 * Copyright 2002,2003 Andi Kleen, SuSE Labs.
 */
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/module.h>
#include <linux/nodemask.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.h>
#include <asm/pci-direct.h>
#include <asm/numa.h>
#include <asm/mpspec.h>
#include <asm/apic.h>
#include <asm/k8.h>

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 -1;
}

static __init void early_get_boot_cpu_id(void)
{
        /*
         * need to get boot_cpu_id so can use that to create apicid_to_node
         * in k8_scan_nodes()
         */
        /*
         * Find possible boot-time SMP configuration:
         */
#ifdef CONFIG_X86_MPPARSE
        early_find_smp_config();
#endif
#ifdef CONFIG_ACPI
        /*
         * Read APIC information from ACPI tables.
         */
        early_acpi_boot_init();
#endif
#ifdef CONFIG_X86_MPPARSE
        /*
         * get boot-time SMP configuration:
         */
        if (smp_found_config)
                early_get_smp_config();
#endif
        early_init_lapic_mapping();
}

int __init k8_scan_nodes(unsigned long start, unsigned long end)
{
        unsigned numnodes, cores, bits, apicid_base;
        unsigned long prevbase;
        struct bootnode nodes[8];
        int i, j, nb, found = 0;
        u32 nodeid, reg;

        if (!early_pci_allowed())
                return -1;

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

        printk(KERN_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 -1;

        printk(KERN_INFO "Number of nodes %d\n", numnodes);

        memset(&nodes, 0, sizeof(nodes));
        prevbase = 0;
        for (i = 0; i < 8; i++) {
                unsigned long base, limit;

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

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

                if (!limit) {
                        printk(KERN_INFO "Skipping node entry %d (base %lx)\n",
                               i, base);
                        continue;
                }
                if ((base >> 8) & 3 || (limit >> 8) & 3) {
                        printk(KERN_ERR "Node %d using interleaving mode %lx/%lx\n",
                               nodeid, (base>>8)&3, (limit>>8) & 3);
                        return -1;
                }
                if (node_isset(nodeid, node_possible_map)) {
                        printk(KERN_INFO "Node %d already present. Skipping\n",
                               nodeid);
                        continue;
                }

                limit >>= 16;
                limit <<= 24;
                limit |= (1<<24)-1;
                limit++;

                if (limit > max_pfn << PAGE_SHIFT)
                        limit = max_pfn << PAGE_SHIFT;
                if (limit <= base)
                        continue;

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

                if (base < start)
                        base = start;
                if (limit > end)
                        limit = end;
                if (limit == base) {
                        printk(KERN_ERR "Empty node %d\n", nodeid);
                        continue;
                }
                if (limit < base) {
                        printk(KERN_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) {
                        printk(KERN_ERR "Node map not sorted %lx,%lx\n",
                               prevbase, base);
                        return -1;
                }

                printk(KERN_INFO "Node %d MemBase %016lx Limit %016lx\n",
                       nodeid, base, limit);

                found++;

                nodes[nodeid].start = base;
                nodes[nodeid].end = limit;

                prevbase = base;

                node_set(nodeid, node_possible_map);
        }

        if (!found)
                return -1;

        memnode_shift = compute_hash_shift(nodes, 8, NULL);
        if (memnode_shift < 0) {
                printk(KERN_ERR "No NUMA node hash function found. Contact maintainer\n");
                return -1;
        }
        printk(KERN_INFO "Using node hash shift of %d\n", memnode_shift);

        /* use the coreid bits from early_identify_cpu */
        bits = boot_cpu_data.x86_coreid_bits;
        cores = (1<<bits);
        apicid_base = 0;
        /* need to get boot_cpu_id early for system with apicid lifting */
        early_get_boot_cpu_id();
        if (boot_cpu_physical_apicid > 0) {
                printk(KERN_INFO "BSP APIC ID: %02x\n",
                                 boot_cpu_physical_apicid);
                apicid_base = boot_cpu_physical_apicid;
        }

        for (i = 0; i < 8; i++) {
                if (nodes[i].start == nodes[i].end)
                        continue;

                e820_register_active_regions(i,
                                nodes[i].start >> PAGE_SHIFT,
                                nodes[i].end >> PAGE_SHIFT);
                for (j = apicid_base; j < cores + apicid_base; j++)
                        apicid_to_node[(i << bits) + j] = i;
                setup_node_bootmem(i, nodes[i].start, nodes[i].end);
        }

        numa_init_array();
        return 0;
}