/*
 * Copyright 2004 James Cleverdon, IBM.
 * Subject to the GNU Public License, v.2
 *
 * Flat APIC subarch code.
 *
 * Hacked for x86-64 by James Cleverdon from i386 architecture code by
 * Martin Bligh, Andi Kleen, James Bottomley, John Stultz, and
 * James Cleverdon.
 */
#include <linux/errno.h>
#include <linux/threads.h>
#include <linux/cpumask.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/ctype.h>
#include <linux/init.h>
#include <linux/hardirq.h>
#include <asm/smp.h>
#include <asm/ipi.h>
#include <asm/genapic.h>
#include <mach_apicdef.h>

#ifdef CONFIG_ACPI
#include <acpi/acpi_bus.h>
#endif

static int flat_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
{
        return 1;
}

static cpumask_t flat_target_cpus(void)
{
        return cpu_online_map;
}

static cpumask_t flat_vector_allocation_domain(int cpu)
{
        /* Careful. Some cpus do not strictly honor the set of cpus
         * specified in the interrupt destination when using lowest
         * priority interrupt delivery mode.
         *
         * In particular there was a hyperthreading cpu observed to
         * deliver interrupts to the wrong hyperthread when only one
         * hyperthread was specified in the interrupt desitination.
         */
        cpumask_t domain = { { [0] = APIC_ALL_CPUS, } };
        return domain;
}

/*
 * 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 flat_init_apic_ldr(void)
{
        unsigned long val;
        unsigned long num, id;

        num = smp_processor_id();
        id = 1UL << num;
        apic_write(APIC_DFR, APIC_DFR_FLAT);
        val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
        val |= SET_APIC_LOGICAL_ID(id);
        apic_write(APIC_LDR, val);
}

static void flat_send_IPI_mask(cpumask_t cpumask, int vector)
{
        unsigned long mask = cpus_addr(cpumask)[0];
        unsigned long flags;

        local_irq_save(flags);
        __send_IPI_dest_field(mask, vector, APIC_DEST_LOGICAL);
        local_irq_restore(flags);
}

static void flat_send_IPI_allbutself(int vector)
{
#ifdef  CONFIG_HOTPLUG_CPU
        int hotplug = 1;
#else
        int hotplug = 0;
#endif
        if (hotplug || vector == NMI_VECTOR) {
                cpumask_t allbutme = cpu_online_map;

                cpu_clear(smp_processor_id(), allbutme);

                if (!cpus_empty(allbutme))
                        flat_send_IPI_mask(allbutme, vector);
        } else if (num_online_cpus() > 1) {
                __send_IPI_shortcut(APIC_DEST_ALLBUT, vector,APIC_DEST_LOGICAL);
        }
}

static void flat_send_IPI_all(int vector)
{
        if (vector == NMI_VECTOR)
                flat_send_IPI_mask(cpu_online_map, vector);
        else
                __send_IPI_shortcut(APIC_DEST_ALLINC, vector, APIC_DEST_LOGICAL);
}

static unsigned int get_apic_id(unsigned long x)
{
        unsigned int id;

        id = (((x)>>24) & 0xFFu);
        return id;
}

static unsigned long set_apic_id(unsigned int id)
{
        unsigned long x;

        x = ((id & 0xFFu)<<24);
        return x;
}

static unsigned int read_xapic_id(void)
{
        unsigned int id;

        id = get_apic_id(apic_read(APIC_ID));
        return id;
}

static int flat_apic_id_registered(void)
{
        return physid_isset(read_xapic_id(), phys_cpu_present_map);
}

static unsigned int flat_cpu_mask_to_apicid(cpumask_t cpumask)
{
        return cpus_addr(cpumask)[0] & APIC_ALL_CPUS;
}

static unsigned int phys_pkg_id(int index_msb)
{
        return hard_smp_processor_id() >> index_msb;
}

struct genapic apic_flat =  {
        .name = "flat",
        .acpi_madt_oem_check = flat_acpi_madt_oem_check,
        .int_delivery_mode = dest_LowestPrio,
        .int_dest_mode = (APIC_DEST_LOGICAL != 0),
        .target_cpus = flat_target_cpus,
        .vector_allocation_domain = flat_vector_allocation_domain,
        .apic_id_registered = flat_apic_id_registered,
        .init_apic_ldr = flat_init_apic_ldr,
        .send_IPI_all = flat_send_IPI_all,
        .send_IPI_allbutself = flat_send_IPI_allbutself,
        .send_IPI_mask = flat_send_IPI_mask,
        .send_IPI_self = apic_send_IPI_self,
        .cpu_mask_to_apicid = flat_cpu_mask_to_apicid,
        .phys_pkg_id = phys_pkg_id,
        .get_apic_id = get_apic_id,
        .set_apic_id = set_apic_id,
        .apic_id_mask = (0xFFu<<24),
};

/*
 * Physflat mode is used when there are more than 8 CPUs on a AMD system.
 * We cannot use logical delivery in this case because the mask
 * overflows, so use physical mode.
 */
static int physflat_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
{
#ifdef CONFIG_ACPI
        /*
         * Quirk: some x86_64 machines can only use physical APIC mode
         * regardless of how many processors are present (x86_64 ES7000
         * is an example).
         */
        if (acpi_gbl_FADT.header.revision > FADT2_REVISION_ID &&
                (acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL)) {
                printk(KERN_DEBUG "system APIC only can use physical flat");
                return 1;
        }
#endif

        return 0;
}

static cpumask_t physflat_target_cpus(void)
{
        return cpu_online_map;
}

static cpumask_t physflat_vector_allocation_domain(int cpu)
{
        return cpumask_of_cpu(cpu);
}

static void physflat_send_IPI_mask(cpumask_t cpumask, int vector)
{
        send_IPI_mask_sequence(cpumask, vector);
}

static void physflat_send_IPI_allbutself(int vector)
{
        cpumask_t allbutme = cpu_online_map;

        cpu_clear(smp_processor_id(), allbutme);
        physflat_send_IPI_mask(allbutme, vector);
}

static void physflat_send_IPI_all(int vector)
{
        physflat_send_IPI_mask(cpu_online_map, vector);
}

static unsigned int physflat_cpu_mask_to_apicid(cpumask_t cpumask)
{
        int cpu;

        /*
         * We're using fixed IRQ delivery, can only return one phys APIC ID.
         * May as well be the first.
         */
        cpu = first_cpu(cpumask);
        if ((unsigned)cpu < nr_cpu_ids)
                return per_cpu(x86_cpu_to_apicid, cpu);
        else
                return BAD_APICID;
}

struct genapic apic_physflat =  {
        .name = "physical flat",
        .acpi_madt_oem_check = physflat_acpi_madt_oem_check,
        .int_delivery_mode = dest_Fixed,
        .int_dest_mode = (APIC_DEST_PHYSICAL != 0),
        .target_cpus = physflat_target_cpus,
        .vector_allocation_domain = physflat_vector_allocation_domain,
        .apic_id_registered = flat_apic_id_registered,
        .init_apic_ldr = flat_init_apic_ldr,/*not needed, but shouldn't hurt*/
        .send_IPI_all = physflat_send_IPI_all,
        .send_IPI_allbutself = physflat_send_IPI_allbutself,
        .send_IPI_mask = physflat_send_IPI_mask,
        .send_IPI_self = apic_send_IPI_self,
        .cpu_mask_to_apicid = physflat_cpu_mask_to_apicid,
        .phys_pkg_id = phys_pkg_id,
        .get_apic_id = get_apic_id,
        .set_apic_id = set_apic_id,
        .apic_id_mask = (0xFFu<<24),
};