// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2005 Intel Corporation
 * Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
 *
 *      Alex Chiang <achiang@hp.com>
 *      - Unified x86/ia64 implementations
 *
 * I/O APIC hotplug support
 *      Yinghai Lu <yinghai@kernel.org>
 *      Jiang Liu <jiang.liu@intel.com>
 */
#include <linux/export.h>
#include <linux/acpi.h>
#include <acpi/processor.h>

static struct acpi_table_madt *get_madt_table(void)
{
        static struct acpi_table_madt *madt;
        static int read_madt;

        if (!read_madt) {
                if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_MADT, 0,
                                        (struct acpi_table_header **)&madt)))
                        madt = NULL;
                read_madt++;
        }

        return madt;
}

static int map_lapic_id(struct acpi_subtable_header *entry,
                 u32 acpi_id, phys_cpuid_t *apic_id)
{
        struct acpi_madt_local_apic *lapic =
                container_of(entry, struct acpi_madt_local_apic, header);

        if (!(lapic->lapic_flags & ACPI_MADT_ENABLED))
                return -ENODEV;

        if (lapic->processor_id != acpi_id)
                return -EINVAL;

        *apic_id = lapic->id;
        return 0;
}

static int map_x2apic_id(struct acpi_subtable_header *entry,
                int device_declaration, u32 acpi_id, phys_cpuid_t *apic_id)
{
        struct acpi_madt_local_x2apic *apic =
                container_of(entry, struct acpi_madt_local_x2apic, header);

        if (!(apic->lapic_flags & ACPI_MADT_ENABLED))
                return -ENODEV;

        if (apic->uid == acpi_id && (device_declaration || acpi_id < 255)) {
                *apic_id = apic->local_apic_id;
                return 0;
        }

        return -EINVAL;
}

static int map_lsapic_id(struct acpi_subtable_header *entry,
                int device_declaration, u32 acpi_id, phys_cpuid_t *apic_id)
{
        struct acpi_madt_local_sapic *lsapic =
                container_of(entry, struct acpi_madt_local_sapic, header);

        if (!(lsapic->lapic_flags & ACPI_MADT_ENABLED))
                return -ENODEV;

        if (device_declaration) {
                if ((entry->length < 16) || (lsapic->uid != acpi_id))
                        return -EINVAL;
        } else if (lsapic->processor_id != acpi_id)
                return -EINVAL;

        *apic_id = (lsapic->id << 8) | lsapic->eid;
        return 0;
}

/*
 * Retrieve the ARM CPU physical identifier (MPIDR)
 */
static int map_gicc_mpidr(struct acpi_subtable_header *entry,
                int device_declaration, u32 acpi_id, phys_cpuid_t *mpidr)
{
        struct acpi_madt_generic_interrupt *gicc =
            container_of(entry, struct acpi_madt_generic_interrupt, header);

        if (!(gicc->flags &
              (ACPI_MADT_ENABLED | ACPI_MADT_GICC_ONLINE_CAPABLE)))
                return -ENODEV;

        /* device_declaration means Device object in DSDT, in the
         * GIC interrupt model, logical processors are required to
         * have a Processor Device object in the DSDT, so we should
         * check device_declaration here
         */
        if (device_declaration && (gicc->uid == acpi_id)) {
                *mpidr = gicc->arm_mpidr;
                return 0;
        }

        return -EINVAL;
}

/*
 * Retrieve the RISC-V hartid for the processor
 */
static int map_rintc_hartid(struct acpi_subtable_header *entry,
                            int device_declaration, u32 acpi_id,
                            phys_cpuid_t *hartid)
{
        struct acpi_madt_rintc *rintc =
            container_of(entry, struct acpi_madt_rintc, header);

        if (!(rintc->flags & ACPI_MADT_ENABLED))
                return -ENODEV;

        /* device_declaration means Device object in DSDT, in the
         * RISC-V, logical processors are required to
         * have a Processor Device object in the DSDT, so we should
         * check device_declaration here
         */
        if (device_declaration && rintc->uid == acpi_id) {
                *hartid = rintc->hart_id;
                return 0;
        }

        return -EINVAL;
}

/*
 * Retrieve LoongArch CPU physical id
 */
static int map_core_pic_id(struct acpi_subtable_header *entry,
                int device_declaration, u32 acpi_id, phys_cpuid_t *phys_id)
{
        struct acpi_madt_core_pic *core_pic =
                container_of(entry, struct acpi_madt_core_pic, header);

        if (!(core_pic->flags & ACPI_MADT_ENABLED))
                return -ENODEV;

        /* device_declaration means Device object in DSDT, in LoongArch
         * system, logical processor acpi_id is required in _UID property
         * of DSDT table, so we should check device_declaration here
         */
        if (device_declaration && (core_pic->processor_id == acpi_id)) {
                *phys_id = core_pic->core_id;
                return 0;
        }

        return -EINVAL;
}

static phys_cpuid_t map_madt_entry(struct acpi_table_madt *madt,
                                   int type, u32 acpi_id)
{
        unsigned long madt_end, entry;
        phys_cpuid_t phys_id = PHYS_CPUID_INVALID;      /* CPU hardware ID */

        if (!madt)
                return phys_id;

        entry = (unsigned long)madt;
        madt_end = entry + madt->header.length;

        /* Parse all entries looking for a match. */

        entry += sizeof(struct acpi_table_madt);
        while (entry + sizeof(struct acpi_subtable_header) < madt_end) {
                struct acpi_subtable_header *header =
                        (struct acpi_subtable_header *)entry;
                if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
                        if (!map_lapic_id(header, acpi_id, &phys_id))
                                break;
                } else if (header->type == ACPI_MADT_TYPE_LOCAL_X2APIC) {
                        if (!map_x2apic_id(header, type, acpi_id, &phys_id))
                                break;
                } else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
                        if (!map_lsapic_id(header, type, acpi_id, &phys_id))
                                break;
                } else if (header->type == ACPI_MADT_TYPE_GENERIC_INTERRUPT) {
                        if (!map_gicc_mpidr(header, type, acpi_id, &phys_id))
                                break;
                } else if (header->type == ACPI_MADT_TYPE_RINTC) {
                        if (!map_rintc_hartid(header, type, acpi_id, &phys_id))
                                break;
                } else if (header->type == ACPI_MADT_TYPE_CORE_PIC) {
                        if (!map_core_pic_id(header, type, acpi_id, &phys_id))
                                break;
                }
                entry += header->length;
        }
        return phys_id;
}

phys_cpuid_t __init acpi_map_madt_entry(u32 acpi_id)
{
        struct acpi_table_madt *madt = NULL;
        phys_cpuid_t rv;

        acpi_get_table(ACPI_SIG_MADT, 0,
                       (struct acpi_table_header **)&madt);
        if (!madt)
                return PHYS_CPUID_INVALID;

        rv = map_madt_entry(madt, 1, acpi_id);

        acpi_put_table((struct acpi_table_header *)madt);

        return rv;
}

int __init acpi_get_madt_revision(void)
{
        struct acpi_table_header *madt = NULL;
        int revision;

        if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_MADT, 0, &madt)))
                return -EINVAL;

        revision = madt->revision;

        acpi_put_table(madt);

        return revision;
}

static phys_cpuid_t map_mat_entry(acpi_handle handle, int type, u32 acpi_id)
{
        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
        union acpi_object *obj;
        struct acpi_subtable_header *header;
        phys_cpuid_t phys_id = PHYS_CPUID_INVALID;

        if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
                goto exit;

        if (!buffer.length || !buffer.pointer)
                goto exit;

        obj = buffer.pointer;
        if (obj->type != ACPI_TYPE_BUFFER ||
            obj->buffer.length < sizeof(struct acpi_subtable_header)) {
                goto exit;
        }

        header = (struct acpi_subtable_header *)obj->buffer.pointer;
        if (header->type == ACPI_MADT_TYPE_LOCAL_APIC)
                map_lapic_id(header, acpi_id, &phys_id);
        else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC)
                map_lsapic_id(header, type, acpi_id, &phys_id);
        else if (header->type == ACPI_MADT_TYPE_LOCAL_X2APIC)
                map_x2apic_id(header, type, acpi_id, &phys_id);
        else if (header->type == ACPI_MADT_TYPE_GENERIC_INTERRUPT)
                map_gicc_mpidr(header, type, acpi_id, &phys_id);
        else if (header->type == ACPI_MADT_TYPE_CORE_PIC)
                map_core_pic_id(header, type, acpi_id, &phys_id);

exit:
        kfree(buffer.pointer);
        return phys_id;
}

phys_cpuid_t acpi_get_phys_id(acpi_handle handle, int type, u32 acpi_id)
{
        phys_cpuid_t phys_id;

        phys_id = map_mat_entry(handle, type, acpi_id);
        if (invalid_phys_cpuid(phys_id))
                phys_id = map_madt_entry(get_madt_table(), type, acpi_id);

        return phys_id;
}
EXPORT_SYMBOL_GPL(acpi_get_phys_id);

int acpi_map_cpuid(phys_cpuid_t phys_id, u32 acpi_id)
{
#ifdef CONFIG_SMP
        int i;
#endif

        if (invalid_phys_cpuid(phys_id)) {
                /*
                 * On UP processor, there is no _MAT or MADT table.
                 * So above phys_id is always set to PHYS_CPUID_INVALID.
                 *
                 * BIOS may define multiple CPU handles even for UP processor.
                 * For example,
                 *
                 * Scope (_PR)
                 * {
                 *     Processor (CPU0, 0x00, 0x00000410, 0x06) {}
                 *     Processor (CPU1, 0x01, 0x00000410, 0x06) {}
                 *     Processor (CPU2, 0x02, 0x00000410, 0x06) {}
                 *     Processor (CPU3, 0x03, 0x00000410, 0x06) {}
                 * }
                 *
                 * Ignores phys_id and always returns 0 for the processor
                 * handle with acpi id 0 if nr_cpu_ids is 1.
                 * This should be the case if SMP tables are not found.
                 * Return -EINVAL for other CPU's handle.
                 */
                if (nr_cpu_ids <= 1 && acpi_id == 0)
                        return acpi_id;
                else
                        return -EINVAL;
        }

#ifdef CONFIG_SMP
        for_each_possible_cpu(i) {
                if (cpu_physical_id(i) == phys_id)
                        return i;
        }
#else
        /* In UP kernel, only processor 0 is valid */
        if (phys_id == 0)
                return phys_id;
#endif
        return -ENODEV;
}

int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
{
        phys_cpuid_t phys_id;

        phys_id = acpi_get_phys_id(handle, type, acpi_id);

        return acpi_map_cpuid(phys_id, acpi_id);
}
EXPORT_SYMBOL_GPL(acpi_get_cpuid);

#ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
static int get_ioapic_id(struct acpi_subtable_header *entry, u32 gsi_base,
                         u64 *phys_addr, int *ioapic_id)
{
        struct acpi_madt_io_apic *ioapic = (struct acpi_madt_io_apic *)entry;

        if (ioapic->global_irq_base != gsi_base)
                return 0;

        *phys_addr = ioapic->address;
        *ioapic_id = ioapic->id;
        return 1;
}

static int parse_madt_ioapic_entry(u32 gsi_base, u64 *phys_addr)
{
        struct acpi_subtable_header *hdr;
        unsigned long madt_end, entry;
        struct acpi_table_madt *madt;
        int apic_id = -1;

        madt = get_madt_table();
        if (!madt)
                return apic_id;

        entry = (unsigned long)madt;
        madt_end = entry + madt->header.length;

        /* Parse all entries looking for a match. */
        entry += sizeof(struct acpi_table_madt);
        while (entry + sizeof(struct acpi_subtable_header) < madt_end) {
                hdr = (struct acpi_subtable_header *)entry;
                if (hdr->type == ACPI_MADT_TYPE_IO_APIC &&
                    get_ioapic_id(hdr, gsi_base, phys_addr, &apic_id))
                        break;
                else
                        entry += hdr->length;
        }

        return apic_id;
}

static int parse_mat_ioapic_entry(acpi_handle handle, u32 gsi_base,
                                  u64 *phys_addr)
{
        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
        struct acpi_subtable_header *header;
        union acpi_object *obj;
        int apic_id = -1;

        if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
                goto exit;

        if (!buffer.length || !buffer.pointer)
                goto exit;

        obj = buffer.pointer;
        if (obj->type != ACPI_TYPE_BUFFER ||
            obj->buffer.length < sizeof(struct acpi_subtable_header))
                goto exit;

        header = (struct acpi_subtable_header *)obj->buffer.pointer;
        if (header->type == ACPI_MADT_TYPE_IO_APIC)
                get_ioapic_id(header, gsi_base, phys_addr, &apic_id);

exit:
        kfree(buffer.pointer);
        return apic_id;
}

/**
 * acpi_get_ioapic_id - Get IOAPIC ID and physical address matching @gsi_base
 * @handle:     ACPI object for IOAPIC device
 * @gsi_base:   GSI base to match with
 * @phys_addr:  Pointer to store physical address of matching IOAPIC record
 *
 * Walk resources returned by ACPI_MAT method, then ACPI MADT table, to search
 * for an ACPI IOAPIC record matching @gsi_base.
 * Return IOAPIC id and store physical address in @phys_addr if found a match,
 * otherwise return <0.
 */
int acpi_get_ioapic_id(acpi_handle handle, u32 gsi_base, u64 *phys_addr)
{
        int apic_id;

        apic_id = parse_mat_ioapic_entry(handle, gsi_base, phys_addr);
        if (apic_id == -1)
                apic_id = parse_madt_ioapic_entry(gsi_base, phys_addr);

        return apic_id;
}
#endif /* CONFIG_ACPI_HOTPLUG_IOAPIC */