/*
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 */

/*
 * Copyright 2016 Tooams Soome <tsoome@me.com>
 */

#include <sys/cdefs.h>

#include <stand.h>
#include <sys/stdint.h>
#include <machine/stdarg.h>
#include <bootstrap.h>
#include <efi.h>
#include <efilib.h>
#include <Guid/Acpi.h>

#include "platform/acfreebsd.h"
#include "acconfig.h"
#define ACPI_SYSTEM_XFACE
#include "actypes.h"
#include "actbl.h"

ACPI_TABLE_RSDP *rsdp;
EFI_GUID gEfiAcpiTableGuid = ACPI_TABLE_GUID;
EFI_GUID gEfiAcpi20TableGuid = EFI_ACPI_TABLE_GUID;

static void *
acpi_map_sdt(vm_offset_t addr)
{
        /* PA == VA */
        return ((void *)addr);
}

static uint8_t
acpi_checksum(const void *p, size_t length)
{
        const uint8_t *bp;
        uint8_t sum;

        bp = p;
        sum = 0;
        while (length--)
                sum += *bp++;

        return (sum);
}

/*
 * We have duplication there, the same implementation is also
 * in libi386/biosacpi.c. We will address this duplication later.
 */
void *
acpi_find_table(const char *sig)
{
        uint_t entries, i;
        ACPI_TABLE_HEADER *sdp;
        ACPI_TABLE_RSDT *rsdt;
        ACPI_TABLE_XSDT *xsdt;

        if (rsdp == NULL)
                return (NULL);

        /*
         * Note, we need to check both address value and size there,
         * as 32-bit code can not access 64-bit address space.
         */
        if (rsdp->Revision >= 2 &&
            rsdp->XsdtPhysicalAddress != 0 &&
            rsdp->XsdtPhysicalAddress < UINTPTR_MAX) {
                xsdt = acpi_map_sdt(rsdp->XsdtPhysicalAddress);
                sdp = (ACPI_TABLE_HEADER *)xsdt;
                if (sdp->Length < sizeof (ACPI_TABLE_HEADER)) {
                        entries = 0;
                } else {
                        entries = sdp->Length - sizeof (ACPI_TABLE_HEADER);
                        entries /= ACPI_XSDT_ENTRY_SIZE;
                }
                for (i = 0; i < entries; i++) {
                        if (xsdt->TableOffsetEntry[i] == 0 ||
                            xsdt->TableOffsetEntry[i] >= UINTPTR_MAX)
                                continue;
                        sdp = acpi_map_sdt(xsdt->TableOffsetEntry[i]);
                        if (sdp->Length < sizeof (ACPI_TABLE_HEADER))
                                continue;

                        if (acpi_checksum(sdp, sdp->Length))
                                continue;

                        if (ACPI_COMPARE_NAME(sig, sdp->Signature))
                                return (sdp);
                }
        }

        if (rsdp->RsdtPhysicalAddress != 0) {
                rsdt = acpi_map_sdt(rsdp->RsdtPhysicalAddress);
                sdp = (ACPI_TABLE_HEADER *)rsdt;
                if (sdp->Length < sizeof (ACPI_TABLE_HEADER)) {
                        entries = 0;
                } else {
                        entries = sdp->Length - sizeof (ACPI_TABLE_HEADER);
                        entries /= ACPI_RSDT_ENTRY_SIZE;
                }
                for (i = 0; i < entries; i++) {
                        if (rsdt->TableOffsetEntry[i] == 0)
                                continue;
                        sdp = acpi_map_sdt(rsdt->TableOffsetEntry[i]);
                        if (sdp->Length < sizeof (ACPI_TABLE_HEADER))
                                continue;

                        if (acpi_checksum(sdp, sdp->Length))
                                continue;

                        if (ACPI_COMPARE_NAME(sig, sdp->Signature))
                                return (sdp);
                }
        }
        return (NULL);
}

void
acpi_detect(void)
{
        char    buf[24];
        int     revision;

        if ((rsdp = efi_get_table(&gEfiAcpi20TableGuid)) == NULL)
                rsdp = efi_get_table(&gEfiAcpiTableGuid);

        if (rsdp == NULL)
                return;

        /* export values from the RSDP */
#ifdef _LP64
        snprintf(buf, sizeof (buf), "0x%016llx", (unsigned long long)rsdp);
#else
        snprintf(buf, sizeof (buf), "0x%08x", (unsigned int)rsdp);
#endif
        setenv("acpi.rsdp", buf, 1);
        revision = rsdp->Revision;
        if (revision == 0)
                revision = 1;
        snprintf(buf, sizeof (buf), "%d", revision);
        setenv("acpi.revision", buf, 1);
        strncpy(buf, rsdp->OemId, sizeof (rsdp->OemId));
        buf[sizeof (rsdp->OemId)] = '\0';
        setenv("acpi.oem", buf, 1);
#ifdef _LP64
        snprintf(buf, sizeof (buf), "0x%016llx",
            (unsigned long long)rsdp->RsdtPhysicalAddress);
#else
        snprintf(buf, sizeof (buf), "0x%08x", rsdp->RsdtPhysicalAddress);
#endif
        setenv("acpi.rsdt", buf, 1);
        if (revision >= 2) {
                snprintf(buf, sizeof (buf), "0x%016llx",
                    (unsigned long long)rsdp->XsdtPhysicalAddress);
                setenv("acpi.xsdt", buf, 1);
                snprintf(buf, sizeof (buf), "%d", rsdp->Length);
                setenv("acpi.xsdt_length", buf, 1);
        }
}