/*
 * Written by: Garry Forsgren, Unisys Corporation
 *             Natalie Protasevich, Unisys Corporation
 *
 * This file contains the code to configure and interface
 * with Unisys ES7000 series hardware system manager.
 *
 * Copyright (c) 2003 Unisys Corporation.
 * Copyright (C) 2009, Red Hat, Inc., Ingo Molnar
 *
 *   All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write the Free Software Foundation, Inc., 59
 * Temple Place - Suite 330, Boston MA 02111-1307, USA.
 *
 * Contact information: Unisys Corporation, Township Line & Union Meeting
 * Roads-A, Unisys Way, Blue Bell, Pennsylvania, 19424, or:
 *
 * http://www.unisys.com
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/notifier.h>
#include <linux/spinlock.h>
#include <linux/cpumask.h>
#include <linux/threads.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/reboot.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/acpi.h>
#include <linux/init.h>
#include <linux/gfp.h>
#include <linux/nmi.h>
#include <linux/smp.h>
#include <linux/io.h>

#include <asm/apicdef.h>
#include <linux/atomic.h>
#include <asm/fixmap.h>
#include <asm/mpspec.h>
#include <asm/setup.h>
#include <asm/apic.h>
#include <asm/ipi.h>

/*
 * ES7000 chipsets
 */

#define NON_UNISYS                      0
#define ES7000_CLASSIC                  1
#define ES7000_ZORRO                    2

#define MIP_REG                         1
#define MIP_PSAI_REG                    4

#define MIP_BUSY                        1
#define MIP_SPIN                        0xf0000
#define MIP_VALID                       0x0100000000000000ULL
#define MIP_SW_APIC                     0x1020b

#define MIP_PORT(val)                   ((val >> 32) & 0xffff)

#define MIP_RD_LO(val)                  (val & 0xffffffff)

struct mip_reg {
        unsigned long long              off_0x00;
        unsigned long long              off_0x08;
        unsigned long long              off_0x10;
        unsigned long long              off_0x18;
        unsigned long long              off_0x20;
        unsigned long long              off_0x28;
        unsigned long long              off_0x30;
        unsigned long long              off_0x38;
};

struct mip_reg_info {
        unsigned long long              mip_info;
        unsigned long long              delivery_info;
        unsigned long long              host_reg;
        unsigned long long              mip_reg;
};

struct psai {
        unsigned long long              entry_type;
        unsigned long long              addr;
        unsigned long long              bep_addr;
};

#ifdef CONFIG_ACPI

struct es7000_oem_table {
        struct acpi_table_header        Header;
        u32                             OEMTableAddr;
        u32                             OEMTableSize;
};

static unsigned long                    oem_addrX;
static unsigned long                    oem_size;

#endif

/*
 * ES7000 Globals
 */

static volatile unsigned long           *psai;
static struct mip_reg                   *mip_reg;
static struct mip_reg                   *host_reg;
static int                              mip_port;
static unsigned long                    mip_addr;
static unsigned long                    host_addr;

int                                     es7000_plat;

/*
 * GSI override for ES7000 platforms.
 */


static int __cpuinit wakeup_secondary_cpu_via_mip(int cpu, unsigned long eip)
{
        unsigned long vect = 0, psaival = 0;

        if (psai == NULL)
                return -1;

        vect = ((unsigned long)__pa(eip)/0x1000) << 16;
        psaival = (0x1000000 | vect | cpu);

        while (*psai & 0x1000000)
                ;

        *psai = psaival;

        return 0;
}

static int es7000_apic_is_cluster(void)
{
        /* MPENTIUMIII */
        if (boot_cpu_data.x86 == 6 &&
            (boot_cpu_data.x86_model >= 7 && boot_cpu_data.x86_model <= 11))
                return 1;

        return 0;
}

static void setup_unisys(void)
{
        /*
         * Determine the generation of the ES7000 currently running.
         *
         * es7000_plat = 1 if the machine is a 5xx ES7000 box
         * es7000_plat = 2 if the machine is a x86_64 ES7000 box
         *
         */
        if (!(boot_cpu_data.x86 <= 15 && boot_cpu_data.x86_model <= 2))
                es7000_plat = ES7000_ZORRO;
        else
                es7000_plat = ES7000_CLASSIC;
}

/*
 * Parse the OEM Table:
 */
static int parse_unisys_oem(char *oemptr)
{
        int                     i;
        int                     success = 0;
        unsigned char           type, size;
        unsigned long           val;
        char                    *tp = NULL;
        struct psai             *psaip = NULL;
        struct mip_reg_info     *mi;
        struct mip_reg          *host, *mip;

        tp = oemptr;

        tp += 8;

        for (i = 0; i <= 6; i++) {
                type = *tp++;
                size = *tp++;
                tp -= 2;
                switch (type) {
                case MIP_REG:
                        mi = (struct mip_reg_info *)tp;
                        val = MIP_RD_LO(mi->host_reg);
                        host_addr = val;
                        host = (struct mip_reg *)val;
                        host_reg = __va(host);
                        val = MIP_RD_LO(mi->mip_reg);
                        mip_port = MIP_PORT(mi->mip_info);
                        mip_addr = val;
                        mip = (struct mip_reg *)val;
                        mip_reg = __va(mip);
                        pr_debug("host_reg = 0x%lx\n",
                                 (unsigned long)host_reg);
                        pr_debug("mip_reg = 0x%lx\n",
                                 (unsigned long)mip_reg);
                        success++;
                        break;
                case MIP_PSAI_REG:
                        psaip = (struct psai *)tp;
                        if (tp != NULL) {
                                if (psaip->addr)
                                        psai = __va(psaip->addr);
                                else
                                        psai = NULL;
                                success++;
                        }
                        break;
                default:
                        break;
                }
                tp += size;
        }

        if (success < 2)
                es7000_plat = NON_UNISYS;
        else
                setup_unisys();

        return es7000_plat;
}

#ifdef CONFIG_ACPI
static int __init find_unisys_acpi_oem_table(unsigned long *oem_addr)
{
        struct acpi_table_header *header = NULL;
        struct es7000_oem_table *table;
        acpi_size tbl_size;
        acpi_status ret;
        int i = 0;

        for (;;) {
                ret = acpi_get_table_with_size("OEM1", i++, &header, &tbl_size);
                if (!ACPI_SUCCESS(ret))
                        return -1;

                if (!memcmp((char *) &header->oem_id, "UNISYS", 6))
                        break;

                early_acpi_os_unmap_memory(header, tbl_size);
        }

        table = (void *)header;

        oem_addrX       = table->OEMTableAddr;
        oem_size        = table->OEMTableSize;

        early_acpi_os_unmap_memory(header, tbl_size);

        *oem_addr       = (unsigned long)__acpi_map_table(oem_addrX, oem_size);

        return 0;
}

static void __init unmap_unisys_acpi_oem_table(unsigned long oem_addr)
{
        if (!oem_addr)
                return;

        __acpi_unmap_table((char *)oem_addr, oem_size);
}

static int es7000_check_dsdt(void)
{
        struct acpi_table_header header;

        if (ACPI_SUCCESS(acpi_get_table_header(ACPI_SIG_DSDT, 0, &header)) &&
            !strncmp(header.oem_id, "UNISYS", 6))
                return 1;
        return 0;
}

static int es7000_acpi_ret;

/* Hook from generic ACPI tables.c */
static int __init es7000_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
{
        unsigned long oem_addr = 0;
        int check_dsdt;
        int ret = 0;

        /* check dsdt at first to avoid clear fix_map for oem_addr */
        check_dsdt = es7000_check_dsdt();

        if (!find_unisys_acpi_oem_table(&oem_addr)) {
                if (check_dsdt) {
                        ret = parse_unisys_oem((char *)oem_addr);
                } else {
                        setup_unisys();
                        ret = 1;
                }
                /*
                 * we need to unmap it
                 */
                unmap_unisys_acpi_oem_table(oem_addr);
        }

        es7000_acpi_ret = ret;

        return ret && !es7000_apic_is_cluster();
}

static int es7000_acpi_madt_oem_check_cluster(char *oem_id, char *oem_table_id)
{
        int ret = es7000_acpi_ret;

        return ret && es7000_apic_is_cluster();
}

#else /* !CONFIG_ACPI: */
static int es7000_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
{
        return 0;
}

static int es7000_acpi_madt_oem_check_cluster(char *oem_id, char *oem_table_id)
{
        return 0;
}
#endif /* !CONFIG_ACPI */

static void es7000_spin(int n)
{
        int i = 0;

        while (i++ < n)
                rep_nop();
}

static int es7000_mip_write(struct mip_reg *mip_reg)
{
        int status = 0;
        int spin;

        spin = MIP_SPIN;
        while ((host_reg->off_0x38 & MIP_VALID) != 0) {
                if (--spin <= 0) {
                        WARN(1, "Timeout waiting for Host Valid Flag\n");
                        return -1;
                }
                es7000_spin(MIP_SPIN);
        }

        memcpy(host_reg, mip_reg, sizeof(struct mip_reg));
        outb(1, mip_port);

        spin = MIP_SPIN;

        while ((mip_reg->off_0x38 & MIP_VALID) == 0) {
                if (--spin <= 0) {
                        WARN(1, "Timeout waiting for MIP Valid Flag\n");
                        return -1;
                }
                es7000_spin(MIP_SPIN);
        }

        status = (mip_reg->off_0x00 & 0xffff0000000000ULL) >> 48;
        mip_reg->off_0x38 &= ~MIP_VALID;

        return status;
}

static void es7000_enable_apic_mode(void)
{
        struct mip_reg es7000_mip_reg;
        int mip_status;

        if (!es7000_plat)
                return;

        pr_info("Enabling APIC mode.\n");
        memset(&es7000_mip_reg, 0, sizeof(struct mip_reg));
        es7000_mip_reg.off_0x00 = MIP_SW_APIC;
        es7000_mip_reg.off_0x38 = MIP_VALID;

        while ((mip_status = es7000_mip_write(&es7000_mip_reg)) != 0)
                WARN(1, "Command failed, status = %x\n", mip_status);
}

static void es7000_wait_for_init_deassert(atomic_t *deassert)
{
        while (!atomic_read(deassert))
                cpu_relax();
}

static unsigned int es7000_get_apic_id(unsigned long x)
{
        return (x >> 24) & 0xFF;
}

static void es7000_send_IPI_mask(const struct cpumask *mask, int vector)
{
        default_send_IPI_mask_sequence_phys(mask, vector);
}

static void es7000_send_IPI_allbutself(int vector)
{
        default_send_IPI_mask_allbutself_phys(cpu_online_mask, vector);
}

static void es7000_send_IPI_all(int vector)
{
        es7000_send_IPI_mask(cpu_online_mask, vector);
}

static int es7000_apic_id_registered(void)
{
        return 1;
}

static const struct cpumask *target_cpus_cluster(void)
{
        return cpu_all_mask;
}

static const struct cpumask *es7000_target_cpus(void)
{
        return cpumask_of(smp_processor_id());
}

static unsigned long es7000_check_apicid_used(physid_mask_t *map, int apicid)
{
        return 0;
}

static unsigned long es7000_check_apicid_present(int bit)
{
        return physid_isset(bit, phys_cpu_present_map);
}

static int es7000_early_logical_apicid(int cpu)
{
        /* on es7000, logical apicid is the same as physical */
        return early_per_cpu(x86_bios_cpu_apicid, cpu);
}

static unsigned long calculate_ldr(int cpu)
{
        unsigned long id = per_cpu(x86_bios_cpu_apicid, cpu);

        return SET_APIC_LOGICAL_ID(id);
}

/*
 * Set up the logical destination ID.
 *
 * Intel recommends to set DFR, LdR and TPR before enabling
 * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel
 * document number 292116).  So here it goes...
 */
static void es7000_init_apic_ldr_cluster(void)
{
        unsigned long val;
        int cpu = smp_processor_id();

        apic_write(APIC_DFR, APIC_DFR_CLUSTER);
        val = calculate_ldr(cpu);
        apic_write(APIC_LDR, val);
}

static void es7000_init_apic_ldr(void)
{
        unsigned long val;
        int cpu = smp_processor_id();

        apic_write(APIC_DFR, APIC_DFR_FLAT);
        val = calculate_ldr(cpu);
        apic_write(APIC_LDR, val);
}

static void es7000_setup_apic_routing(void)
{
        int apic = per_cpu(x86_bios_cpu_apicid, smp_processor_id());

        pr_info("Enabling APIC mode:  %s. Using %d I/O APICs, target cpus %lx\n",
                (apic_version[apic] == 0x14) ?
                        "Physical Cluster" : "Logical Cluster",
                nr_ioapics, cpumask_bits(es7000_target_cpus())[0]);
}

static int es7000_cpu_present_to_apicid(int mps_cpu)
{
        if (!mps_cpu)
                return boot_cpu_physical_apicid;
        else if (mps_cpu < nr_cpu_ids)
                return per_cpu(x86_bios_cpu_apicid, mps_cpu);
        else
                return BAD_APICID;
}

static int cpu_id;

static void es7000_apicid_to_cpu_present(int phys_apicid, physid_mask_t *retmap)
{
        physid_set_mask_of_physid(cpu_id, retmap);
        ++cpu_id;
}

static void es7000_ioapic_phys_id_map(physid_mask_t *phys_map, physid_mask_t *retmap)
{
        /* For clustered we don't have a good way to do this yet - hack */
        physids_promote(0xFFL, retmap);
}

static int es7000_check_phys_apicid_present(int cpu_physical_apicid)
{
        boot_cpu_physical_apicid = read_apic_id();
        return 1;
}

static inline int
es7000_cpu_mask_to_apicid(const struct cpumask *cpumask, unsigned int *dest_id)
{
        unsigned int round = 0;
        unsigned int cpu, uninitialized_var(apicid);

        /*
         * The cpus in the mask must all be on the apic cluster.
         */
        for_each_cpu_and(cpu, cpumask, cpu_online_mask) {
                int new_apicid = early_per_cpu(x86_cpu_to_logical_apicid, cpu);

                if (round && APIC_CLUSTER(apicid) != APIC_CLUSTER(new_apicid)) {
                        WARN(1, "Not a valid mask!");

                        return -EINVAL;
                }
                apicid |= new_apicid;
                round++;
        }
        if (!round)
                return -EINVAL;
        *dest_id = apicid;
        return 0;
}

static int
es7000_cpu_mask_to_apicid_and(const struct cpumask *inmask,
                              const struct cpumask *andmask,
                              unsigned int *apicid)
{
        cpumask_var_t cpumask;
        *apicid = early_per_cpu(x86_cpu_to_logical_apicid, 0);

        if (!alloc_cpumask_var(&cpumask, GFP_ATOMIC))
                return 0;

        cpumask_and(cpumask, inmask, andmask);
        es7000_cpu_mask_to_apicid(cpumask, apicid);

        free_cpumask_var(cpumask);

        return 0;
}

static int es7000_phys_pkg_id(int cpuid_apic, int index_msb)
{
        return cpuid_apic >> index_msb;
}

static int probe_es7000(void)
{
        /* probed later in mptable/ACPI hooks */
        return 0;
}

static int es7000_mps_ret;
static int es7000_mps_oem_check(struct mpc_table *mpc, char *oem,
                char *productid)
{
        int ret = 0;

        if (mpc->oemptr) {
                struct mpc_oemtable *oem_table =
                        (struct mpc_oemtable *)mpc->oemptr;

                if (!strncmp(oem, "UNISYS", 6))
                        ret = parse_unisys_oem((char *)oem_table);
        }

        es7000_mps_ret = ret;

        return ret && !es7000_apic_is_cluster();
}

static int es7000_mps_oem_check_cluster(struct mpc_table *mpc, char *oem,
                char *productid)
{
        int ret = es7000_mps_ret;

        return ret && es7000_apic_is_cluster();
}

/* We've been warned by a false positive warning.Use __refdata to keep calm. */
static struct apic __refdata apic_es7000_cluster = {

        .name                           = "es7000",
        .probe                          = probe_es7000,
        .acpi_madt_oem_check            = es7000_acpi_madt_oem_check_cluster,
        .apic_id_valid                  = default_apic_id_valid,
        .apic_id_registered             = es7000_apic_id_registered,

        .irq_delivery_mode              = dest_LowestPrio,
        /* logical delivery broadcast to all procs: */
        .irq_dest_mode                  = 1,

        .target_cpus                    = target_cpus_cluster,
        .disable_esr                    = 1,
        .dest_logical                   = 0,
        .check_apicid_used              = es7000_check_apicid_used,
        .check_apicid_present           = es7000_check_apicid_present,

        .vector_allocation_domain       = flat_vector_allocation_domain,
        .init_apic_ldr                  = es7000_init_apic_ldr_cluster,

        .ioapic_phys_id_map             = es7000_ioapic_phys_id_map,
        .setup_apic_routing             = es7000_setup_apic_routing,
        .multi_timer_check              = NULL,
        .cpu_present_to_apicid          = es7000_cpu_present_to_apicid,
        .apicid_to_cpu_present          = es7000_apicid_to_cpu_present,
        .setup_portio_remap             = NULL,
        .check_phys_apicid_present      = es7000_check_phys_apicid_present,
        .enable_apic_mode               = es7000_enable_apic_mode,
        .phys_pkg_id                    = es7000_phys_pkg_id,
        .mps_oem_check                  = es7000_mps_oem_check_cluster,

        .get_apic_id                    = es7000_get_apic_id,
        .set_apic_id                    = NULL,
        .apic_id_mask                   = 0xFF << 24,

        .cpu_mask_to_apicid_and         = es7000_cpu_mask_to_apicid_and,

        .send_IPI_mask                  = es7000_send_IPI_mask,
        .send_IPI_mask_allbutself       = NULL,
        .send_IPI_allbutself            = es7000_send_IPI_allbutself,
        .send_IPI_all                   = es7000_send_IPI_all,
        .send_IPI_self                  = default_send_IPI_self,

        .wakeup_secondary_cpu           = wakeup_secondary_cpu_via_mip,

        .trampoline_phys_low            = 0x467,
        .trampoline_phys_high           = 0x469,

        .wait_for_init_deassert         = NULL,

        /* Nothing to do for most platforms, since cleared by the INIT cycle: */
        .smp_callin_clear_local_apic    = NULL,
        .inquire_remote_apic            = default_inquire_remote_apic,

        .read                           = native_apic_mem_read,
        .write                          = native_apic_mem_write,
        .eoi_write                      = native_apic_mem_write,
        .icr_read                       = native_apic_icr_read,
        .icr_write                      = native_apic_icr_write,
        .wait_icr_idle                  = native_apic_wait_icr_idle,
        .safe_wait_icr_idle             = native_safe_apic_wait_icr_idle,

        .x86_32_early_logical_apicid    = es7000_early_logical_apicid,
};

static struct apic __refdata apic_es7000 = {

        .name                           = "es7000",
        .probe                          = probe_es7000,
        .acpi_madt_oem_check            = es7000_acpi_madt_oem_check,
        .apic_id_valid                  = default_apic_id_valid,
        .apic_id_registered             = es7000_apic_id_registered,

        .irq_delivery_mode              = dest_Fixed,
        /* phys delivery to target CPUs: */
        .irq_dest_mode                  = 0,

        .target_cpus                    = es7000_target_cpus,
        .disable_esr                    = 1,
        .dest_logical                   = 0,
        .check_apicid_used              = es7000_check_apicid_used,
        .check_apicid_present           = es7000_check_apicid_present,

        .vector_allocation_domain       = flat_vector_allocation_domain,
        .init_apic_ldr                  = es7000_init_apic_ldr,

        .ioapic_phys_id_map             = es7000_ioapic_phys_id_map,
        .setup_apic_routing             = es7000_setup_apic_routing,
        .multi_timer_check              = NULL,
        .cpu_present_to_apicid          = es7000_cpu_present_to_apicid,
        .apicid_to_cpu_present          = es7000_apicid_to_cpu_present,
        .setup_portio_remap             = NULL,
        .check_phys_apicid_present      = es7000_check_phys_apicid_present,
        .enable_apic_mode               = es7000_enable_apic_mode,
        .phys_pkg_id                    = es7000_phys_pkg_id,
        .mps_oem_check                  = es7000_mps_oem_check,

        .get_apic_id                    = es7000_get_apic_id,
        .set_apic_id                    = NULL,
        .apic_id_mask                   = 0xFF << 24,

        .cpu_mask_to_apicid_and         = es7000_cpu_mask_to_apicid_and,

        .send_IPI_mask                  = es7000_send_IPI_mask,
        .send_IPI_mask_allbutself       = NULL,
        .send_IPI_allbutself            = es7000_send_IPI_allbutself,
        .send_IPI_all                   = es7000_send_IPI_all,
        .send_IPI_self                  = default_send_IPI_self,

        .trampoline_phys_low            = 0x467,
        .trampoline_phys_high           = 0x469,

        .wait_for_init_deassert         = es7000_wait_for_init_deassert,

        /* Nothing to do for most platforms, since cleared by the INIT cycle: */
        .smp_callin_clear_local_apic    = NULL,
        .inquire_remote_apic            = default_inquire_remote_apic,

        .read                           = native_apic_mem_read,
        .write                          = native_apic_mem_write,
        .eoi_write                      = native_apic_mem_write,
        .icr_read                       = native_apic_icr_read,
        .icr_write                      = native_apic_icr_write,
        .wait_icr_idle                  = native_apic_wait_icr_idle,
        .safe_wait_icr_idle             = native_safe_apic_wait_icr_idle,

        .x86_32_early_logical_apicid    = es7000_early_logical_apicid,
};

/*
 * Need to check for es7000 followed by es7000_cluster, so this order
 * in apic_drivers is important.
 */
apic_drivers(apic_es7000, apic_es7000_cluster);