// SPDX-License-Identifier: GPL-2.0

#include <linux/cpumask.h>
#include <linux/acpi.h>

#include "local.h"

int x2apic_phys;

static struct apic apic_x2apic_phys;
static u32 x2apic_max_apicid __ro_after_init;

void __init x2apic_set_max_apicid(u32 apicid)
{
        x2apic_max_apicid = apicid;
}

static int __init set_x2apic_phys_mode(char *arg)
{
        x2apic_phys = 1;
        return 0;
}
early_param("x2apic_phys", set_x2apic_phys_mode);

static bool x2apic_fadt_phys(void)
{
#ifdef CONFIG_ACPI
        if ((acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID) &&
                (acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL)) {
                printk(KERN_DEBUG "System requires x2apic physical mode\n");
                return true;
        }
#endif
        return false;
}

static int x2apic_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
{
        return x2apic_enabled() && (x2apic_phys || x2apic_fadt_phys());
}

static void x2apic_send_IPI(int cpu, int vector)
{
        u32 dest = per_cpu(x86_cpu_to_apicid, cpu);

        /* x2apic MSRs are special and need a special fence: */
        weak_wrmsr_fence();
        __x2apic_send_IPI_dest(dest, vector, APIC_DEST_PHYSICAL);
}

static void
__x2apic_send_IPI_mask(const struct cpumask *mask, int vector, int apic_dest)
{
        unsigned long query_cpu;
        unsigned long this_cpu;
        unsigned long flags;

        /* x2apic MSRs are special and need a special fence: */
        weak_wrmsr_fence();

        local_irq_save(flags);

        this_cpu = smp_processor_id();
        for_each_cpu(query_cpu, mask) {
                if (apic_dest == APIC_DEST_ALLBUT && this_cpu == query_cpu)
                        continue;
                __x2apic_send_IPI_dest(per_cpu(x86_cpu_to_apicid, query_cpu),
                                       vector, APIC_DEST_PHYSICAL);
        }
        local_irq_restore(flags);
}

static void x2apic_send_IPI_mask(const struct cpumask *mask, int vector)
{
        __x2apic_send_IPI_mask(mask, vector, APIC_DEST_ALLINC);
}

static void
 x2apic_send_IPI_mask_allbutself(const struct cpumask *mask, int vector)
{
        __x2apic_send_IPI_mask(mask, vector, APIC_DEST_ALLBUT);
}

static void x2apic_send_IPI_allbutself(int vector)
{
        __x2apic_send_IPI_shorthand(vector, APIC_DEST_ALLBUT);
}

static void x2apic_send_IPI_all(int vector)
{
        __x2apic_send_IPI_shorthand(vector, APIC_DEST_ALLINC);
}

static void init_x2apic_ldr(void)
{
}

static int x2apic_phys_probe(void)
{
        if (x2apic_mode && (x2apic_phys || x2apic_fadt_phys()))
                return 1;

        return apic == &apic_x2apic_phys;
}

/* Common x2apic functions, also used by x2apic_cluster */
int x2apic_apic_id_valid(u32 apicid)
{
        if (x2apic_max_apicid && apicid > x2apic_max_apicid)
                return 0;

        return 1;
}

int x2apic_apic_id_registered(void)
{
        return 1;
}

void __x2apic_send_IPI_dest(unsigned int apicid, int vector, unsigned int dest)
{
        unsigned long cfg = __prepare_ICR(0, vector, dest);
        native_x2apic_icr_write(cfg, apicid);
}

void __x2apic_send_IPI_shorthand(int vector, u32 which)
{
        unsigned long cfg = __prepare_ICR(which, vector, 0);

        /* x2apic MSRs are special and need a special fence: */
        weak_wrmsr_fence();
        native_x2apic_icr_write(cfg, 0);
}

unsigned int x2apic_get_apic_id(unsigned long id)
{
        return id;
}

u32 x2apic_set_apic_id(unsigned int id)
{
        return id;
}

int x2apic_phys_pkg_id(int initial_apicid, int index_msb)
{
        return initial_apicid >> index_msb;
}

void x2apic_send_IPI_self(int vector)
{
        apic_write(APIC_SELF_IPI, vector);
}

static struct apic apic_x2apic_phys __ro_after_init = {

        .name                           = "physical x2apic",
        .probe                          = x2apic_phys_probe,
        .acpi_madt_oem_check            = x2apic_acpi_madt_oem_check,
        .apic_id_valid                  = x2apic_apic_id_valid,
        .apic_id_registered             = x2apic_apic_id_registered,

        .delivery_mode                  = APIC_DELIVERY_MODE_FIXED,
        .dest_mode_logical              = false,

        .disable_esr                    = 0,

        .check_apicid_used              = NULL,
        .init_apic_ldr                  = init_x2apic_ldr,
        .ioapic_phys_id_map             = NULL,
        .setup_apic_routing             = NULL,
        .cpu_present_to_apicid          = default_cpu_present_to_apicid,
        .apicid_to_cpu_present          = NULL,
        .check_phys_apicid_present      = default_check_phys_apicid_present,
        .phys_pkg_id                    = x2apic_phys_pkg_id,

        .get_apic_id                    = x2apic_get_apic_id,
        .set_apic_id                    = x2apic_set_apic_id,

        .calc_dest_apicid               = apic_default_calc_apicid,

        .send_IPI                       = x2apic_send_IPI,
        .send_IPI_mask                  = x2apic_send_IPI_mask,
        .send_IPI_mask_allbutself       = x2apic_send_IPI_mask_allbutself,
        .send_IPI_allbutself            = x2apic_send_IPI_allbutself,
        .send_IPI_all                   = x2apic_send_IPI_all,
        .send_IPI_self                  = x2apic_send_IPI_self,

        .inquire_remote_apic            = NULL,

        .read                           = native_apic_msr_read,
        .write                          = native_apic_msr_write,
        .eoi_write                      = native_apic_msr_eoi_write,
        .icr_read                       = native_x2apic_icr_read,
        .icr_write                      = native_x2apic_icr_write,
        .wait_icr_idle                  = native_x2apic_wait_icr_idle,
        .safe_wait_icr_idle             = native_safe_x2apic_wait_icr_idle,
};

apic_driver(apic_x2apic_phys);