[deliverable/linux.git] / arch / x86 / kernel / mpparse.c

/*
 *      Intel Multiprocessor Specification 1.1 and 1.4
 *      compliant MP-table parsing routines.
 *
 *      (c) 1995 Alan Cox, Building #3 <alan@lxorguk.ukuu.org.uk>
 *      (c) 1998, 1999, 2000, 2009 Ingo Molnar <mingo@redhat.com>
 *      (c) 2008 Alexey Starikovskiy <astarikovskiy@suse.de>
 */

#include <linux/mm.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/bootmem.h>
#include <linux/kernel_stat.h>
#include <linux/mc146818rtc.h>
#include <linux/bitops.h>
#include <linux/acpi.h>
#include <linux/module.h>
#include <linux/smp.h>
#include <linux/pci.h>

#include <asm/mtrr.h>
#include <asm/mpspec.h>
#include <asm/pgalloc.h>
#include <asm/io_apic.h>
#include <asm/proto.h>
#include <asm/bios_ebda.h>
#include <asm/e820.h>
#include <asm/trampoline.h>
#include <asm/setup.h>
#include <asm/smp.h>

#include <asm/apic.h>
/*
 * Checksum an MP configuration block.
 */

static int __init mpf_checksum(unsigned char *mp, int len)
{
        int sum = 0;

        while (len--)
                sum += *mp++;

        return sum & 0xFF;
}

int __init default_mpc_apic_id(struct mpc_cpu *m)
{
        return m->apicid;
}

static void __init MP_processor_info(struct mpc_cpu *m)
{
        int apicid;
        char *bootup_cpu = "";

        if (!(m->cpuflag & CPU_ENABLED)) {
                disabled_cpus++;
                return;
        }

        apicid = x86_init.mpparse.mpc_apic_id(m);

        if (m->cpuflag & CPU_BOOTPROCESSOR) {
                bootup_cpu = " (Bootup-CPU)";
                boot_cpu_physical_apicid = m->apicid;
        }

        printk(KERN_INFO "Processor #%d%s\n", m->apicid, bootup_cpu);
        generic_processor_info(apicid, m->apicver);
}

#ifdef CONFIG_X86_IO_APIC
void __init default_mpc_oem_bus_info(struct mpc_bus *m, char *str)
{
        memcpy(str, m->bustype, 6);
        str[6] = 0;
        apic_printk(APIC_VERBOSE, "Bus #%d is %s\n", m->busid, str);
}

static void __init MP_bus_info(struct mpc_bus *m)
{
        char str[7];

        x86_init.mpparse.mpc_oem_bus_info(m, str);

#if MAX_MP_BUSSES < 256
        if (m->busid >= MAX_MP_BUSSES) {
                printk(KERN_WARNING "MP table busid value (%d) for bustype %s "
                       " is too large, max. supported is %d\n",
                       m->busid, str, MAX_MP_BUSSES - 1);
                return;
        }
#endif

        if (strncmp(str, BUSTYPE_ISA, sizeof(BUSTYPE_ISA) - 1) == 0) {
                set_bit(m->busid, mp_bus_not_pci);
#if defined(CONFIG_EISA) || defined(CONFIG_MCA)
                mp_bus_id_to_type[m->busid] = MP_BUS_ISA;
#endif
        } else if (strncmp(str, BUSTYPE_PCI, sizeof(BUSTYPE_PCI) - 1) == 0) {
                if (x86_init.mpparse.mpc_oem_pci_bus)
                        x86_init.mpparse.mpc_oem_pci_bus(m);

                clear_bit(m->busid, mp_bus_not_pci);
#if defined(CONFIG_EISA) || defined(CONFIG_MCA)
                mp_bus_id_to_type[m->busid] = MP_BUS_PCI;
        } else if (strncmp(str, BUSTYPE_EISA, sizeof(BUSTYPE_EISA) - 1) == 0) {
                mp_bus_id_to_type[m->busid] = MP_BUS_EISA;
        } else if (strncmp(str, BUSTYPE_MCA, sizeof(BUSTYPE_MCA) - 1) == 0) {
                mp_bus_id_to_type[m->busid] = MP_BUS_MCA;
#endif
        } else
                printk(KERN_WARNING "Unknown bustype %s - ignoring\n", str);
}

static int bad_ioapic(unsigned long address)
{
        if (nr_ioapics >= MAX_IO_APICS) {
                printk(KERN_ERR "ERROR: Max # of I/O APICs (%d) exceeded "
                       "(found %d)\n", MAX_IO_APICS, nr_ioapics);
                panic("Recompile kernel with bigger MAX_IO_APICS!\n");
        }
        if (!address) {
                printk(KERN_ERR "WARNING: Bogus (zero) I/O APIC address"
                       " found in table, skipping!\n");
                return 1;
        }
        return 0;
}

static void __init MP_ioapic_info(struct mpc_ioapic *m)
{
        if (!(m->flags & MPC_APIC_USABLE))
                return;

        printk(KERN_INFO "I/O APIC #%d Version %d at 0x%X.\n",
               m->apicid, m->apicver, m->apicaddr);

        if (bad_ioapic(m->apicaddr))
                return;

        mp_ioapics[nr_ioapics].apicaddr = m->apicaddr;
        mp_ioapics[nr_ioapics].apicid = m->apicid;
        mp_ioapics[nr_ioapics].type = m->type;
        mp_ioapics[nr_ioapics].apicver = m->apicver;
        mp_ioapics[nr_ioapics].flags = m->flags;
        nr_ioapics++;
}

static void print_MP_intsrc_info(struct mpc_intsrc *m)
{
        apic_printk(APIC_VERBOSE, "Int: type %d, pol %d, trig %d, bus %02x,"
                " IRQ %02x, APIC ID %x, APIC INT %02x\n",
                m->irqtype, m->irqflag & 3, (m->irqflag >> 2) & 3, m->srcbus,
                m->srcbusirq, m->dstapic, m->dstirq);
}

static void __init print_mp_irq_info(struct mpc_intsrc *mp_irq)
{
        apic_printk(APIC_VERBOSE, "Int: type %d, pol %d, trig %d, bus %02x,"
                " IRQ %02x, APIC ID %x, APIC INT %02x\n",
                mp_irq->irqtype, mp_irq->irqflag & 3,
                (mp_irq->irqflag >> 2) & 3, mp_irq->srcbus,
                mp_irq->srcbusirq, mp_irq->dstapic, mp_irq->dstirq);
}

static void __init assign_to_mp_irq(struct mpc_intsrc *m,
                                    struct mpc_intsrc *mp_irq)
{
        mp_irq->dstapic = m->dstapic;
        mp_irq->type = m->type;
        mp_irq->irqtype = m->irqtype;
        mp_irq->irqflag = m->irqflag;
        mp_irq->srcbus = m->srcbus;
        mp_irq->srcbusirq = m->srcbusirq;
        mp_irq->dstirq = m->dstirq;
}

static void __init assign_to_mpc_intsrc(struct mpc_intsrc *mp_irq,
                                        struct mpc_intsrc *m)
{
        m->dstapic = mp_irq->dstapic;
        m->type = mp_irq->type;
        m->irqtype = mp_irq->irqtype;
        m->irqflag = mp_irq->irqflag;
        m->srcbus = mp_irq->srcbus;
        m->srcbusirq = mp_irq->srcbusirq;
        m->dstirq = mp_irq->dstirq;
}

static int __init mp_irq_mpc_intsrc_cmp(struct mpc_intsrc *mp_irq,
                                        struct mpc_intsrc *m)
{
        if (mp_irq->dstapic != m->dstapic)
                return 1;
        if (mp_irq->type != m->type)
                return 2;
        if (mp_irq->irqtype != m->irqtype)
                return 3;
        if (mp_irq->irqflag != m->irqflag)
                return 4;
        if (mp_irq->srcbus != m->srcbus)
                return 5;
        if (mp_irq->srcbusirq != m->srcbusirq)
                return 6;
        if (mp_irq->dstirq != m->dstirq)
                return 7;

        return 0;
}

static void __init MP_intsrc_info(struct mpc_intsrc *m)
{
        int i;

        print_MP_intsrc_info(m);

        for (i = 0; i < mp_irq_entries; i++) {
                if (!mp_irq_mpc_intsrc_cmp(&mp_irqs[i], m))
                        return;
        }

        assign_to_mp_irq(m, &mp_irqs[mp_irq_entries]);
        if (++mp_irq_entries == MAX_IRQ_SOURCES)
                panic("Max # of irq sources exceeded!!\n");
}
#else /* CONFIG_X86_IO_APIC */
static inline void __init MP_bus_info(struct mpc_bus *m) {}
static inline void __init MP_ioapic_info(struct mpc_ioapic *m) {}
static inline void __init MP_intsrc_info(struct mpc_intsrc *m) {}
#endif /* CONFIG_X86_IO_APIC */


static void __init MP_lintsrc_info(struct mpc_lintsrc *m)
{
        apic_printk(APIC_VERBOSE, "Lint: type %d, pol %d, trig %d, bus %02x,"
                " IRQ %02x, APIC ID %x, APIC LINT %02x\n",
                m->irqtype, m->irqflag & 3, (m->irqflag >> 2) & 3, m->srcbusid,
                m->srcbusirq, m->destapic, m->destapiclint);
}

/*
 * Read/parse the MPC
 */

static int __init smp_check_mpc(struct mpc_table *mpc, char *oem, char *str)
{

        if (memcmp(mpc->signature, MPC_SIGNATURE, 4)) {
                printk(KERN_ERR "MPTABLE: bad signature [%c%c%c%c]!\n",
                       mpc->signature[0], mpc->signature[1],
                       mpc->signature[2], mpc->signature[3]);
                return 0;
        }
        if (mpf_checksum((unsigned char *)mpc, mpc->length)) {
                printk(KERN_ERR "MPTABLE: checksum error!\n");
                return 0;
        }
        if (mpc->spec != 0x01 && mpc->spec != 0x04) {
                printk(KERN_ERR "MPTABLE: bad table version (%d)!!\n",
                       mpc->spec);
                return 0;
        }
        if (!mpc->lapic) {
                printk(KERN_ERR "MPTABLE: null local APIC address!\n");
                return 0;
        }
        memcpy(oem, mpc->oem, 8);
        oem[8] = 0;
        printk(KERN_INFO "MPTABLE: OEM ID: %s\n", oem);

        memcpy(str, mpc->productid, 12);
        str[12] = 0;

        printk(KERN_INFO "MPTABLE: Product ID: %s\n", str);

        printk(KERN_INFO "MPTABLE: APIC at: 0x%X\n", mpc->lapic);

        return 1;
}

static void skip_entry(unsigned char **ptr, int *count, int size)
{
        *ptr += size;
        *count += size;
}

static void __init smp_dump_mptable(struct mpc_table *mpc, unsigned char *mpt)
{
        printk(KERN_ERR "Your mptable is wrong, contact your HW vendor!\n"
                "type %x\n", *mpt);
        print_hex_dump(KERN_ERR, "  ", DUMP_PREFIX_ADDRESS, 16,
                        1, mpc, mpc->length, 1);
}

void __init default_smp_read_mpc_oem(struct mpc_table *mpc) { }

static int __init smp_read_mpc(struct mpc_table *mpc, unsigned early)
{
        char str[16];
        char oem[10];

        int count = sizeof(*mpc);
        unsigned char *mpt = ((unsigned char *)mpc) + count;

        if (!smp_check_mpc(mpc, oem, str))
                return 0;

#ifdef CONFIG_X86_32
        generic_mps_oem_check(mpc, oem, str);
#endif
        /* save the local APIC address, it might be non-default */
        if (!acpi_lapic)
                mp_lapic_addr = mpc->lapic;

        if (early)
                return 1;

        if (mpc->oemptr)
                x86_init.mpparse.smp_read_mpc_oem(mpc);

        /*
         *      Now process the configuration blocks.
         */
        x86_init.mpparse.mpc_record(0);

        while (count < mpc->length) {
                switch (*mpt) {
                case MP_PROCESSOR:
                        /* ACPI may have already provided this data */
                        if (!acpi_lapic)
                                MP_processor_info((struct mpc_cpu *)mpt);
                        skip_entry(&mpt, &count, sizeof(struct mpc_cpu));
                        break;
                case MP_BUS:
                        MP_bus_info((struct mpc_bus *)mpt);
                        skip_entry(&mpt, &count, sizeof(struct mpc_bus));
                        break;
                case MP_IOAPIC:
                        MP_ioapic_info((struct mpc_ioapic *)mpt);
                        skip_entry(&mpt, &count, sizeof(struct mpc_ioapic));
                        break;
                case MP_INTSRC:
                        MP_intsrc_info((struct mpc_intsrc *)mpt);
                        skip_entry(&mpt, &count, sizeof(struct mpc_intsrc));
                        break;
                case MP_LINTSRC:
                        MP_lintsrc_info((struct mpc_lintsrc *)mpt);
                        skip_entry(&mpt, &count, sizeof(struct mpc_lintsrc));
                        break;
                default:
                        /* wrong mptable */
                        smp_dump_mptable(mpc, mpt);
                        count = mpc->length;
                        break;
                }
                x86_init.mpparse.mpc_record(1);
        }

#ifdef CONFIG_X86_BIGSMP
        generic_bigsmp_probe();
#endif

        if (apic->setup_apic_routing)
                apic->setup_apic_routing();

        if (!num_processors)
                printk(KERN_ERR "MPTABLE: no processors registered!\n");
        return num_processors;
}

#ifdef CONFIG_X86_IO_APIC

static int __init ELCR_trigger(unsigned int irq)
{
        unsigned int port;

        port = 0x4d0 + (irq >> 3);
        return (inb(port) >> (irq & 7)) & 1;
}

static void __init construct_default_ioirq_mptable(int mpc_default_type)
{
        struct mpc_intsrc intsrc;
        int i;
        int ELCR_fallback = 0;

        intsrc.type = MP_INTSRC;
        intsrc.irqflag = 0;     /* conforming */
        intsrc.srcbus = 0;
        intsrc.dstapic = mp_ioapics[0].apicid;

        intsrc.irqtype = mp_INT;

        /*
         *  If true, we have an ISA/PCI system with no IRQ entries
         *  in the MP table. To prevent the PCI interrupts from being set up
         *  incorrectly, we try to use the ELCR. The sanity check to see if
         *  there is good ELCR data is very simple - IRQ0, 1, 2 and 13 can
         *  never be level sensitive, so we simply see if the ELCR agrees.
         *  If it does, we assume it's valid.
         */
        if (mpc_default_type == 5) {
                printk(KERN_INFO "ISA/PCI bus type with no IRQ information... "
                       "falling back to ELCR\n");

                if (ELCR_trigger(0) || ELCR_trigger(1) || ELCR_trigger(2) ||
                    ELCR_trigger(13))
                        printk(KERN_ERR "ELCR contains invalid data... "
                               "not using ELCR\n");
                else {
                        printk(KERN_INFO
                               "Using ELCR to identify PCI interrupts\n");
                        ELCR_fallback = 1;
                }
        }

        for (i = 0; i < 16; i++) {
                switch (mpc_default_type) {
                case 2:
                        if (i == 0 || i == 13)
                                continue;       /* IRQ0 & IRQ13 not connected */
                        /* fall through */
                default:
                        if (i == 2)
                                continue;       /* IRQ2 is never connected */
                }

                if (ELCR_fallback) {
                        /*
                         *  If the ELCR indicates a level-sensitive interrupt, we
                         *  copy that information over to the MP table in the
                         *  irqflag field (level sensitive, active high polarity).
                         */
                        if (ELCR_trigger(i))
                                intsrc.irqflag = 13;
                        else
                                intsrc.irqflag = 0;
                }

                intsrc.srcbusirq = i;
                intsrc.dstirq = i ? i : 2;      /* IRQ0 to INTIN2 */
                MP_intsrc_info(&intsrc);
        }

        intsrc.irqtype = mp_ExtINT;
        intsrc.srcbusirq = 0;
        intsrc.dstirq = 0;      /* 8259A to INTIN0 */
        MP_intsrc_info(&intsrc);
}


static void __init construct_ioapic_table(int mpc_default_type)
{
        struct mpc_ioapic ioapic;
        struct mpc_bus bus;

        bus.type = MP_BUS;
        bus.busid = 0;
        switch (mpc_default_type) {
        default:
                printk(KERN_ERR "???\nUnknown standard configuration %d\n",
                       mpc_default_type);
                /* fall through */
        case 1:
        case 5:
                memcpy(bus.bustype, "ISA   ", 6);
                break;
        case 2:
        case 6:
        case 3:
                memcpy(bus.bustype, "EISA  ", 6);
                break;
        case 4:
        case 7:
                memcpy(bus.bustype, "MCA   ", 6);
        }
        MP_bus_info(&bus);
        if (mpc_default_type > 4) {
                bus.busid = 1;
                memcpy(bus.bustype, "PCI   ", 6);
                MP_bus_info(&bus);
        }

        ioapic.type = MP_IOAPIC;
        ioapic.apicid = 2;
        ioapic.apicver = mpc_default_type > 4 ? 0x10 : 0x01;
        ioapic.flags = MPC_APIC_USABLE;
        ioapic.apicaddr = 0xFEC00000;
        MP_ioapic_info(&ioapic);

        /*
         * We set up most of the low 16 IO-APIC pins according to MPS rules.
         */
        construct_default_ioirq_mptable(mpc_default_type);
}
#else
static inline void __init construct_ioapic_table(int mpc_default_type) { }
#endif

static inline void __init construct_default_ISA_mptable(int mpc_default_type)
{
        struct mpc_cpu processor;
        struct mpc_lintsrc lintsrc;
        int linttypes[2] = { mp_ExtINT, mp_NMI };
        int i;

        /*
         * local APIC has default address
         */
        mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;

        /*
         * 2 CPUs, numbered 0 & 1.
         */
        processor.type = MP_PROCESSOR;
        /* Either an integrated APIC or a discrete 82489DX. */
        processor.apicver = mpc_default_type > 4 ? 0x10 : 0x01;
        processor.cpuflag = CPU_ENABLED;
        processor.cpufeature = (boot_cpu_data.x86 << 8) |
            (boot_cpu_data.x86_model << 4) | boot_cpu_data.x86_mask;
        processor.featureflag = boot_cpu_data.x86_capability[0];
        processor.reserved[0] = 0;
        processor.reserved[1] = 0;
        for (i = 0; i < 2; i++) {
                processor.apicid = i;
                MP_processor_info(&processor);
        }

        construct_ioapic_table(mpc_default_type);

        lintsrc.type = MP_LINTSRC;
        lintsrc.irqflag = 0;            /* conforming */
        lintsrc.srcbusid = 0;
        lintsrc.srcbusirq = 0;
        lintsrc.destapic = MP_APIC_ALL;
        for (i = 0; i < 2; i++) {
                lintsrc.irqtype = linttypes[i];
                lintsrc.destapiclint = i;
                MP_lintsrc_info(&lintsrc);
        }
}

static struct mpf_intel *mpf_found;

static unsigned long __init get_mpc_size(unsigned long physptr)
{
        struct mpc_table *mpc;
        unsigned long size;

        mpc = early_ioremap(physptr, PAGE_SIZE);
        size = mpc->length;
        early_iounmap(mpc, PAGE_SIZE);
        apic_printk(APIC_VERBOSE, "  mpc: %lx-%lx\n", physptr, physptr + size);

        return size;
}

static int __init check_physptr(struct mpf_intel *mpf, unsigned int early)
{
        struct mpc_table *mpc;
        unsigned long size;

        size = get_mpc_size(mpf->physptr);
        mpc = early_ioremap(mpf->physptr, size);
        /*
         * Read the physical hardware table.  Anything here will
         * override the defaults.
         */
        if (!smp_read_mpc(mpc, early)) {
#ifdef CONFIG_X86_LOCAL_APIC
                smp_found_config = 0;
#endif
                printk(KERN_ERR "BIOS bug, MP table errors detected!...\n"
                        "... disabling SMP support. (tell your hw vendor)\n");
                early_iounmap(mpc, size);
                return -1;
        }
        early_iounmap(mpc, size);

        if (early)
                return -1;

#ifdef CONFIG_X86_IO_APIC
        /*
         * If there are no explicit MP IRQ entries, then we are
         * broken.  We set up most of the low 16 IO-APIC pins to
         * ISA defaults and hope it will work.
         */
        if (!mp_irq_entries) {
                struct mpc_bus bus;

                printk(KERN_ERR "BIOS bug, no explicit IRQ entries, "
                       "using default mptable. (tell your hw vendor)\n");

                bus.type = MP_BUS;
                bus.busid = 0;
                memcpy(bus.bustype, "ISA   ", 6);
                MP_bus_info(&bus);

                construct_default_ioirq_mptable(0);
        }
#endif

        return 0;
}

/*
 * Scan the memory blocks for an SMP configuration block.
 */
static void __init __get_smp_config(unsigned int early)
{
        struct mpf_intel *mpf = mpf_found;

        if (!mpf)
                return;

        if (acpi_lapic && early)
                return;

        /*
         * MPS doesn't support hyperthreading, aka only have
         * thread 0 apic id in MPS table
         */
        if (acpi_lapic && acpi_ioapic)
                return;

        if (x86_quirks->mach_get_smp_config) {
                if (x86_quirks->mach_get_smp_config(early))
                        return;
        }

        printk(KERN_INFO "Intel MultiProcessor Specification v1.%d\n",
               mpf->specification);
#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86_32)
        if (mpf->feature2 & (1 << 7)) {
                printk(KERN_INFO "    IMCR and PIC compatibility mode.\n");
                pic_mode = 1;
        } else {
                printk(KERN_INFO "    Virtual Wire compatibility mode.\n");
                pic_mode = 0;
        }
#endif
        /*
         * Now see if we need to read further.
         */
        if (mpf->feature1 != 0) {
                if (early) {
                        /*
                         * local APIC has default address
                         */
                        mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
                        return;
                }

                printk(KERN_INFO "Default MP configuration #%d\n",
                       mpf->feature1);
                construct_default_ISA_mptable(mpf->feature1);

        } else if (mpf->physptr) {
                if (check_physptr(mpf, early))
                        return;
        } else
                BUG();

        if (!early)
                printk(KERN_INFO "Processors: %d\n", num_processors);
        /*
         * Only use the first configuration found.
         */
}

void __init early_get_smp_config(void)
{
        __get_smp_config(1);
}

void __init get_smp_config(void)
{
        __get_smp_config(0);
}

static void __init smp_reserve_bootmem(struct mpf_intel *mpf)
{
        unsigned long size = get_mpc_size(mpf->physptr);
#ifdef CONFIG_X86_32
        /*
         * We cannot access to MPC table to compute table size yet,
         * as only few megabytes from the bottom is mapped now.
         * PC-9800's MPC table places on the very last of physical
         * memory; so that simply reserving PAGE_SIZE from mpf->physptr
         * yields BUG() in reserve_bootmem.
         * also need to make sure physptr is below than max_low_pfn
         * we don't need reserve the area above max_low_pfn
         */
        unsigned long end = max_low_pfn * PAGE_SIZE;

        if (mpf->physptr < end) {
                if (mpf->physptr + size > end)
                        size = end - mpf->physptr;
                reserve_bootmem_generic(mpf->physptr, size, BOOTMEM_DEFAULT);
        }
#else
        reserve_bootmem_generic(mpf->physptr, size, BOOTMEM_DEFAULT);
#endif
}

static int __init smp_scan_config(unsigned long base, unsigned long length,
                                  unsigned reserve)
{
        unsigned int *bp = phys_to_virt(base);
        struct mpf_intel *mpf;

        apic_printk(APIC_VERBOSE, "Scan SMP from %p for %ld bytes.\n",
                        bp, length);
        BUILD_BUG_ON(sizeof(*mpf) != 16);

        while (length > 0) {
                mpf = (struct mpf_intel *)bp;
                if ((*bp == SMP_MAGIC_IDENT) &&
                    (mpf->length == 1) &&
                    !mpf_checksum((unsigned char *)bp, 16) &&
                    ((mpf->specification == 1)
                     || (mpf->specification == 4))) {
#ifdef CONFIG_X86_LOCAL_APIC
                        smp_found_config = 1;
#endif
                        mpf_found = mpf;

                        printk(KERN_INFO "found SMP MP-table at [%p] %llx\n",
                               mpf, (u64)virt_to_phys(mpf));

                        if (!reserve)
                                return 1;
                        reserve_bootmem_generic(virt_to_phys(mpf), sizeof(*mpf),
                                                BOOTMEM_DEFAULT);
                        if (mpf->physptr)
                                smp_reserve_bootmem(mpf);

                        return 1;
                }
                bp += 4;
                length -= 16;
        }
        return 0;
}

static void __init __find_smp_config(unsigned int reserve)
{
        unsigned int address;

        if (x86_quirks->mach_find_smp_config) {
                if (x86_quirks->mach_find_smp_config(reserve))
                        return;
        }
        /*
         * FIXME: Linux assumes you have 640K of base ram..
         * this continues the error...
         *
         * 1) Scan the bottom 1K for a signature
         * 2) Scan the top 1K of base RAM
         * 3) Scan the 64K of bios
         */
        if (smp_scan_config(0x0, 0x400, reserve) ||
            smp_scan_config(639 * 0x400, 0x400, reserve) ||
            smp_scan_config(0xF0000, 0x10000, reserve))
                return;
        /*
         * If it is an SMP machine we should know now, unless the
         * configuration is in an EISA/MCA bus machine with an
         * extended bios data area.
         *
         * there is a real-mode segmented pointer pointing to the
         * 4K EBDA area at 0x40E, calculate and scan it here.
         *
         * NOTE! There are Linux loaders that will corrupt the EBDA
         * area, and as such this kind of SMP config may be less
         * trustworthy, simply because the SMP table may have been
         * stomped on during early boot. These loaders are buggy and
         * should be fixed.
         *
         * MP1.4 SPEC states to only scan first 1K of 4K EBDA.
         */

        address = get_bios_ebda();
        if (address)
                smp_scan_config(address, 0x400, reserve);
}

void __init early_find_smp_config(void)
{
        __find_smp_config(0);
}

void __init find_smp_config(void)
{
        __find_smp_config(1);
}

#ifdef CONFIG_X86_IO_APIC
static u8 __initdata irq_used[MAX_IRQ_SOURCES];

static int  __init get_MP_intsrc_index(struct mpc_intsrc *m)
{
        int i;

        if (m->irqtype != mp_INT)
                return 0;

        if (m->irqflag != 0x0f)
                return 0;

        /* not legacy */

        for (i = 0; i < mp_irq_entries; i++) {
                if (mp_irqs[i].irqtype != mp_INT)
                        continue;

                if (mp_irqs[i].irqflag != 0x0f)
                        continue;

                if (mp_irqs[i].srcbus != m->srcbus)
                        continue;
                if (mp_irqs[i].srcbusirq != m->srcbusirq)
                        continue;
                if (irq_used[i]) {
                        /* already claimed */
                        return -2;
                }
                irq_used[i] = 1;
                return i;
        }

        /* not found */
        return -1;
}

#define SPARE_SLOT_NUM 20

static struct mpc_intsrc __initdata *m_spare[SPARE_SLOT_NUM];

static void __init check_irq_src(struct mpc_intsrc *m, int *nr_m_spare)
{
        int i;

        apic_printk(APIC_VERBOSE, "OLD ");
        print_MP_intsrc_info(m);

        i = get_MP_intsrc_index(m);
        if (i > 0) {
                assign_to_mpc_intsrc(&mp_irqs[i], m);
                apic_printk(APIC_VERBOSE, "NEW ");
                print_mp_irq_info(&mp_irqs[i]);
                return;
        }
        if (!i) {
                /* legacy, do nothing */
                return;
        }
        if (*nr_m_spare < SPARE_SLOT_NUM) {
                /*
                 * not found (-1), or duplicated (-2) are invalid entries,
                 * we need to use the slot later
                 */
                m_spare[*nr_m_spare] = m;
                *nr_m_spare += 1;
        }
}
#else /* CONFIG_X86_IO_APIC */
static
inline void __init check_irq_src(struct mpc_intsrc *m, int *nr_m_spare) {}
#endif /* CONFIG_X86_IO_APIC */

static int
check_slot(unsigned long mpc_new_phys, unsigned long mpc_new_length, int count)
{
        int ret = 0;

        if (!mpc_new_phys || count <= mpc_new_length) {
                WARN(1, "update_mptable: No spare slots (length: %x)\n", count);
                return -1;
        }

        return ret;
}

static int  __init replace_intsrc_all(struct mpc_table *mpc,
                                        unsigned long mpc_new_phys,
                                        unsigned long mpc_new_length)
{
#ifdef CONFIG_X86_IO_APIC
        int i;
#endif
        int count = sizeof(*mpc);
        int nr_m_spare = 0;
        unsigned char *mpt = ((unsigned char *)mpc) + count;

        printk(KERN_INFO "mpc_length %x\n", mpc->length);
        while (count < mpc->length) {
                switch (*mpt) {
                case MP_PROCESSOR:
                        skip_entry(&mpt, &count, sizeof(struct mpc_cpu));
                        break;
                case MP_BUS:
                        skip_entry(&mpt, &count, sizeof(struct mpc_bus));
                        break;
                case MP_IOAPIC:
                        skip_entry(&mpt, &count, sizeof(struct mpc_ioapic));
                        break;
                case MP_INTSRC:
                        check_irq_src((struct mpc_intsrc *)mpt, &nr_m_spare);
                        skip_entry(&mpt, &count, sizeof(struct mpc_intsrc));
                        break;
                case MP_LINTSRC:
                        skip_entry(&mpt, &count, sizeof(struct mpc_lintsrc));
                        break;
                default:
                        /* wrong mptable */
                        smp_dump_mptable(mpc, mpt);
                        goto out;
                }
        }

#ifdef CONFIG_X86_IO_APIC
        for (i = 0; i < mp_irq_entries; i++) {
                if (irq_used[i])
                        continue;

                if (mp_irqs[i].irqtype != mp_INT)
                        continue;

                if (mp_irqs[i].irqflag != 0x0f)
                        continue;

                if (nr_m_spare > 0) {
                        apic_printk(APIC_VERBOSE, "*NEW* found\n");
                        nr_m_spare--;
                        assign_to_mpc_intsrc(&mp_irqs[i], m_spare[nr_m_spare]);
                        m_spare[nr_m_spare] = NULL;
                } else {
                        struct mpc_intsrc *m = (struct mpc_intsrc *)mpt;
                        count += sizeof(struct mpc_intsrc);
                        if (check_slot(mpc_new_phys, mpc_new_length, count) < 0)
                                goto out;
                        assign_to_mpc_intsrc(&mp_irqs[i], m);
                        mpc->length = count;
                        mpt += sizeof(struct mpc_intsrc);
                }
                print_mp_irq_info(&mp_irqs[i]);
        }
#endif
out:
        /* update checksum */
        mpc->checksum = 0;
        mpc->checksum -= mpf_checksum((unsigned char *)mpc, mpc->length);

        return 0;
}

int enable_update_mptable;

static int __init update_mptable_setup(char *str)
{
        enable_update_mptable = 1;
#ifdef CONFIG_PCI
        pci_routeirq = 1;
#endif
        return 0;
}
early_param("update_mptable", update_mptable_setup);

static unsigned long __initdata mpc_new_phys;
static unsigned long mpc_new_length __initdata = 4096;

/* alloc_mptable or alloc_mptable=4k */
static int __initdata alloc_mptable;
static int __init parse_alloc_mptable_opt(char *p)
{
        enable_update_mptable = 1;
#ifdef CONFIG_PCI
        pci_routeirq = 1;
#endif
        alloc_mptable = 1;
        if (!p)
                return 0;
        mpc_new_length = memparse(p, &p);
        return 0;
}
early_param("alloc_mptable", parse_alloc_mptable_opt);

void __init early_reserve_e820_mpc_new(void)
{
        if (enable_update_mptable && alloc_mptable) {
                u64 startt = 0;
#ifdef CONFIG_X86_TRAMPOLINE
                startt = TRAMPOLINE_BASE;
#endif
                mpc_new_phys = early_reserve_e820(startt, mpc_new_length, 4);
        }
}

static int __init update_mp_table(void)
{
        char str[16];
        char oem[10];
        struct mpf_intel *mpf;
        struct mpc_table *mpc, *mpc_new;

        if (!enable_update_mptable)
                return 0;

        mpf = mpf_found;
        if (!mpf)
                return 0;

        /*
         * Now see if we need to go further.
         */
        if (mpf->feature1 != 0)
                return 0;

        if (!mpf->physptr)
                return 0;

        mpc = phys_to_virt(mpf->physptr);

        if (!smp_check_mpc(mpc, oem, str))
                return 0;

        printk(KERN_INFO "mpf: %llx\n", (u64)virt_to_phys(mpf));
        printk(KERN_INFO "physptr: %x\n", mpf->physptr);

        if (mpc_new_phys && mpc->length > mpc_new_length) {
                mpc_new_phys = 0;
                printk(KERN_INFO "mpc_new_length is %ld, please use alloc_mptable=8k\n",
                         mpc_new_length);
        }

        if (!mpc_new_phys) {
                unsigned char old, new;
                /* check if we can change the postion */
                mpc->checksum = 0;
                old = mpf_checksum((unsigned char *)mpc, mpc->length);
                mpc->checksum = 0xff;
                new = mpf_checksum((unsigned char *)mpc, mpc->length);
                if (old == new) {
                        printk(KERN_INFO "mpc is readonly, please try alloc_mptable instead\n");
                        return 0;
                }
                printk(KERN_INFO "use in-positon replacing\n");
        } else {
                mpf->physptr = mpc_new_phys;
                mpc_new = phys_to_virt(mpc_new_phys);
                memcpy(mpc_new, mpc, mpc->length);
                mpc = mpc_new;
                /* check if we can modify that */
                if (mpc_new_phys - mpf->physptr) {
                        struct mpf_intel *mpf_new;
                        /* steal 16 bytes from [0, 1k) */
                        printk(KERN_INFO "mpf new: %x\n", 0x400 - 16);
                        mpf_new = phys_to_virt(0x400 - 16);
                        memcpy(mpf_new, mpf, 16);
                        mpf = mpf_new;
                        mpf->physptr = mpc_new_phys;
                }
                mpf->checksum = 0;
                mpf->checksum -= mpf_checksum((unsigned char *)mpf, 16);
                printk(KERN_INFO "physptr new: %x\n", mpf->physptr);
        }

        /*
         * only replace the one with mp_INT and
         *       MP_IRQ_TRIGGER_LEVEL|MP_IRQ_POLARITY_LOW,
         * already in mp_irqs , stored by ... and mp_config_acpi_gsi,
         * may need pci=routeirq for all coverage
         */
        replace_intsrc_all(mpc, mpc_new_phys, mpc_new_length);

        return 0;
}

late_initcall(update_mp_table);