#include <linux/init.h>
#include <linux/pci.h>
#include <linux/topology.h>
#include <linux/cpu.h>
#include <linux/range.h>

#include <asm/amd_nb.h>
#include <asm/pci_x86.h>

#include <asm/pci-direct.h>

#include "bus_numa.h"

/*
 * This discovers the pcibus <-> node mapping on AMD K8.
 * also get peer root bus resource for io,mmio
 */

struct pci_hostbridge_probe {
        u32 bus;
        u32 slot;
        u32 vendor;
        u32 device;
};

static struct pci_hostbridge_probe pci_probes[] __initdata = {
        { 0, 0x18, PCI_VENDOR_ID_AMD, 0x1100 },
        { 0, 0x18, PCI_VENDOR_ID_AMD, 0x1200 },
        { 0xff, 0, PCI_VENDOR_ID_AMD, 0x1200 },
        { 0, 0x18, PCI_VENDOR_ID_AMD, 0x1300 },
};

static u64 __initdata fam10h_mmconf_start;
static u64 __initdata fam10h_mmconf_end;
static void __init get_pci_mmcfg_amd_fam10h_range(void)
{
        u32 address;
        u64 base, msr;
        unsigned segn_busn_bits;

        /* assume all cpus from fam10h have mmconf */
        if (boot_cpu_data.x86 < 0x10)
                return;

        address = MSR_FAM10H_MMIO_CONF_BASE;
        rdmsrl(address, msr);

        /* mmconfig is not enable */
        if (!(msr & FAM10H_MMIO_CONF_ENABLE))
                return;

        base = msr & (FAM10H_MMIO_CONF_BASE_MASK<<FAM10H_MMIO_CONF_BASE_SHIFT);

        segn_busn_bits = (msr >> FAM10H_MMIO_CONF_BUSRANGE_SHIFT) &
                         FAM10H_MMIO_CONF_BUSRANGE_MASK;

        fam10h_mmconf_start = base;
        fam10h_mmconf_end = base + (1ULL<<(segn_busn_bits + 20)) - 1;
}

#define RANGE_NUM 16

/**
 * early_fill_mp_bus_to_node()
 * called before pcibios_scan_root and pci_scan_bus
 * fills the mp_bus_to_cpumask array based according to the LDT Bus Number
 * Registers found in the K8 northbridge
 */
static int __init early_fill_mp_bus_info(void)
{
        int i;
        int j;
        unsigned bus;
        unsigned slot;
        int node;
        int link;
        int def_node;
        int def_link;
        struct pci_root_info *info;
        u32 reg;
        struct resource *res;
        u64 start;
        u64 end;
        struct range range[RANGE_NUM];
        u64 val;
        u32 address;
        bool found;

        if (!early_pci_allowed())
                return -1;

        found = false;
        for (i = 0; i < ARRAY_SIZE(pci_probes); i++) {
                u32 id;
                u16 device;
                u16 vendor;

                bus = pci_probes[i].bus;
                slot = pci_probes[i].slot;
                id = read_pci_config(bus, slot, 0, PCI_VENDOR_ID);

                vendor = id & 0xffff;
                device = (id>>16) & 0xffff;
                if (pci_probes[i].vendor == vendor &&
                    pci_probes[i].device == device) {
                        found = true;
                        break;
                }
        }

        if (!found)
                return 0;

        pci_root_num = 0;
        for (i = 0; i < 4; i++) {
                int min_bus;
                int max_bus;
                reg = read_pci_config(bus, slot, 1, 0xe0 + (i << 2));

                /* Check if that register is enabled for bus range */
                if ((reg & 7) != 3)
                        continue;

                min_bus = (reg >> 16) & 0xff;
                max_bus = (reg >> 24) & 0xff;
                node = (reg >> 4) & 0x07;
#ifdef CONFIG_NUMA
                for (j = min_bus; j <= max_bus; j++)
                        set_mp_bus_to_node(j, node);
#endif
                link = (reg >> 8) & 0x03;

                info = &pci_root_info[pci_root_num];
                info->bus_min = min_bus;
                info->bus_max = max_bus;
                info->node = node;
                info->link = link;
                sprintf(info->name, "PCI Bus #%02x", min_bus);
                pci_root_num++;
        }

        /* get the default node and link for left over res */
        reg = read_pci_config(bus, slot, 0, 0x60);
        def_node = (reg >> 8) & 0x07;
        reg = read_pci_config(bus, slot, 0, 0x64);
        def_link = (reg >> 8) & 0x03;

        memset(range, 0, sizeof(range));
        add_range(range, RANGE_NUM, 0, 0, 0xffff + 1);
        /* io port resource */
        for (i = 0; i < 4; i++) {
                reg = read_pci_config(bus, slot, 1, 0xc0 + (i << 3));
                if (!(reg & 3))
                        continue;

                start = reg & 0xfff000;
                reg = read_pci_config(bus, slot, 1, 0xc4 + (i << 3));
                node = reg & 0x07;
                link = (reg >> 4) & 0x03;
                end = (reg & 0xfff000) | 0xfff;

                /* find the position */
                for (j = 0; j < pci_root_num; j++) {
                        info = &pci_root_info[j];
                        if (info->node == node && info->link == link)
                                break;
                }
                if (j == pci_root_num)
                        continue; /* not found */

                info = &pci_root_info[j];
                printk(KERN_DEBUG "node %d link %d: io port [%llx, %llx]\n",
                       node, link, start, end);

                /* kernel only handle 16 bit only */
                if (end > 0xffff)
                        end = 0xffff;
                update_res(info, start, end, IORESOURCE_IO, 1);
                subtract_range(range, RANGE_NUM, start, end + 1);
        }
        /* add left over io port range to def node/link, [0, 0xffff] */
        /* find the position */
        for (j = 0; j < pci_root_num; j++) {
                info = &pci_root_info[j];
                if (info->node == def_node && info->link == def_link)
                        break;
        }
        if (j < pci_root_num) {
                info = &pci_root_info[j];
                for (i = 0; i < RANGE_NUM; i++) {
                        if (!range[i].end)
                                continue;

                        update_res(info, range[i].start, range[i].end - 1,
                                   IORESOURCE_IO, 1);
                }
        }

        memset(range, 0, sizeof(range));
        /* 0xfd00000000-0xffffffffff for HT */
        end = cap_resource((0xfdULL<<32) - 1);
        end++;
        add_range(range, RANGE_NUM, 0, 0, end);

        /* need to take out [0, TOM) for RAM*/
        address = MSR_K8_TOP_MEM1;
        rdmsrl(address, val);
        end = (val & 0xffffff800000ULL);
        printk(KERN_INFO "TOM: %016llx aka %lldM\n", end, end>>20);
        if (end < (1ULL<<32))
                subtract_range(range, RANGE_NUM, 0, end);

        /* get mmconfig */
        get_pci_mmcfg_amd_fam10h_range();
        /* need to take out mmconf range */
        if (fam10h_mmconf_end) {
                printk(KERN_DEBUG "Fam 10h mmconf [%llx, %llx]\n", fam10h_mmconf_start, fam10h_mmconf_end);
                subtract_range(range, RANGE_NUM, fam10h_mmconf_start,
                                 fam10h_mmconf_end + 1);
        }

        /* mmio resource */
        for (i = 0; i < 8; i++) {
                reg = read_pci_config(bus, slot, 1, 0x80 + (i << 3));
                if (!(reg & 3))
                        continue;

                start = reg & 0xffffff00; /* 39:16 on 31:8*/
                start <<= 8;
                reg = read_pci_config(bus, slot, 1, 0x84 + (i << 3));
                node = reg & 0x07;
                link = (reg >> 4) & 0x03;
                end = (reg & 0xffffff00);
                end <<= 8;
                end |= 0xffff;

                /* find the position */
                for (j = 0; j < pci_root_num; j++) {
                        info = &pci_root_info[j];
                        if (info->node == node && info->link == link)
                                break;
                }
                if (j == pci_root_num)
                        continue; /* not found */

                info = &pci_root_info[j];

                printk(KERN_DEBUG "node %d link %d: mmio [%llx, %llx]",
                       node, link, start, end);
                /*
                 * some sick allocation would have range overlap with fam10h
                 * mmconf range, so need to update start and end.
                 */
                if (fam10h_mmconf_end) {
                        int changed = 0;
                        u64 endx = 0;
                        if (start >= fam10h_mmconf_start &&
                            start <= fam10h_mmconf_end) {
                                start = fam10h_mmconf_end + 1;
                                changed = 1;
                        }

                        if (end >= fam10h_mmconf_start &&
                            end <= fam10h_mmconf_end) {
                                end = fam10h_mmconf_start - 1;
                                changed = 1;
                        }

                        if (start < fam10h_mmconf_start &&
                            end > fam10h_mmconf_end) {
                                /* we got a hole */
                                endx = fam10h_mmconf_start - 1;
                                update_res(info, start, endx, IORESOURCE_MEM, 0);
                                subtract_range(range, RANGE_NUM, start,
                                                 endx + 1);
                                printk(KERN_CONT " ==> [%llx, %llx]", start, endx);
                                start = fam10h_mmconf_end + 1;
                                changed = 1;
                        }
                        if (changed) {
                                if (start <= end) {
                                        printk(KERN_CONT " %s [%llx, %llx]", endx ? "and" : "==>", start, end);
                                } else {
                                        printk(KERN_CONT "%s\n", endx?"":" ==> none");
                                        continue;
                                }
                        }
                }

                update_res(info, cap_resource(start), cap_resource(end),
                                 IORESOURCE_MEM, 1);
                subtract_range(range, RANGE_NUM, start, end + 1);
                printk(KERN_CONT "\n");
        }

        /* need to take out [4G, TOM2) for RAM*/
        /* SYS_CFG */
        address = MSR_K8_SYSCFG;
        rdmsrl(address, val);
        /* TOP_MEM2 is enabled? */
        if (val & (1<<21)) {
                /* TOP_MEM2 */
                address = MSR_K8_TOP_MEM2;
                rdmsrl(address, val);
                end = (val & 0xffffff800000ULL);
                printk(KERN_INFO "TOM2: %016llx aka %lldM\n", end, end>>20);
                subtract_range(range, RANGE_NUM, 1ULL<<32, end);
        }

        /*
         * add left over mmio range to def node/link ?
         * that is tricky, just record range in from start_min to 4G
         */
        for (j = 0; j < pci_root_num; j++) {
                info = &pci_root_info[j];
                if (info->node == def_node && info->link == def_link)
                        break;
        }
        if (j < pci_root_num) {
                info = &pci_root_info[j];

                for (i = 0; i < RANGE_NUM; i++) {
                        if (!range[i].end)
                                continue;

                        update_res(info, cap_resource(range[i].start),
                                   cap_resource(range[i].end - 1),
                                   IORESOURCE_MEM, 1);
                }
        }

        for (i = 0; i < pci_root_num; i++) {
                int res_num;
                int busnum;

                info = &pci_root_info[i];
                res_num = info->res_num;
                busnum = info->bus_min;
                printk(KERN_DEBUG "bus: [%02x, %02x] on node %x link %x\n",
                       info->bus_min, info->bus_max, info->node, info->link);
                for (j = 0; j < res_num; j++) {
                        res = &info->res[j];
                        printk(KERN_DEBUG "bus: %02x index %x %pR\n",
                                       busnum, j, res);
                }
        }

        return 0;
}

#define ENABLE_CF8_EXT_CFG      (1ULL << 46)

static void enable_pci_io_ecs(void *unused)
{
        u64 reg;
        rdmsrl(MSR_AMD64_NB_CFG, reg);
        if (!(reg & ENABLE_CF8_EXT_CFG)) {
                reg |= ENABLE_CF8_EXT_CFG;
                wrmsrl(MSR_AMD64_NB_CFG, reg);
        }
}

static int __cpuinit amd_cpu_notify(struct notifier_block *self,
                                    unsigned long action, void *hcpu)
{
        int cpu = (long)hcpu;
        switch (action) {
        case CPU_ONLINE:
        case CPU_ONLINE_FROZEN:
                smp_call_function_single(cpu, enable_pci_io_ecs, NULL, 0);
                break;
        default:
                break;
        }
        return NOTIFY_OK;
}

static struct notifier_block __cpuinitdata amd_cpu_notifier = {
        .notifier_call  = amd_cpu_notify,
};

static void __init pci_enable_pci_io_ecs(void)
{
#ifdef CONFIG_AMD_NB
        unsigned int i, n;

        for (n = i = 0; !n && amd_nb_bus_dev_ranges[i].dev_limit; ++i) {
                u8 bus = amd_nb_bus_dev_ranges[i].bus;
                u8 slot = amd_nb_bus_dev_ranges[i].dev_base;
                u8 limit = amd_nb_bus_dev_ranges[i].dev_limit;

                for (; slot < limit; ++slot) {
                        u32 val = read_pci_config(bus, slot, 3, 0);

                        if (!early_is_amd_nb(val))
                                continue;

                        val = read_pci_config(bus, slot, 3, 0x8c);
                        if (!(val & (ENABLE_CF8_EXT_CFG >> 32))) {
                                val |= ENABLE_CF8_EXT_CFG >> 32;
                                write_pci_config(bus, slot, 3, 0x8c, val);
                        }
                        ++n;
                }
        }
        pr_info("Extended Config Space enabled on %u nodes\n", n);
#endif
}

static int __init pci_io_ecs_init(void)
{
        int cpu;

        /* assume all cpus from fam10h have IO ECS */
        if (boot_cpu_data.x86 < 0x10)
                return 0;

        /* Try the PCI method first. */
        if (early_pci_allowed())
                pci_enable_pci_io_ecs();

        register_cpu_notifier(&amd_cpu_notifier);
        for_each_online_cpu(cpu)
                amd_cpu_notify(&amd_cpu_notifier, (unsigned long)CPU_ONLINE,
                               (void *)(long)cpu);
        pci_probe |= PCI_HAS_IO_ECS;

        return 0;
}

static int __init amd_postcore_init(void)
{
        if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
                return 0;

        early_fill_mp_bus_info();
        pci_io_ecs_init();

        return 0;
}

postcore_initcall(amd_postcore_init);