source: mainline/kernel/genarch/src/acpi/acpi.c

/*
 * Copyright (c) 2005 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup kernel_genarch
 * @{
 */

/**
 * @file
 * @brief Advanced Configuration and Power Interface (ACPI) initialization.
 */

#include <genarch/acpi/acpi.h>
#include <genarch/acpi/madt.h>
#include <arch/bios/bios.h>
#include <debug.h>
#include <mm/page.h>
#include <mm/km.h>
#include <log.h>
#include <memw.h>

#define RSDP_SIGNATURE      "RSD PTR "
#define RSDP_REVISION_OFFS  15

#define CMP_SIGNATURE(left, right) \
        (((left)[0] == (right)[0]) && \
        ((left)[1] == (right)[1]) && \
        ((left)[2] == (right)[2]) && \
        ((left)[3] == (right)[3]))

struct acpi_rsdp *acpi_rsdp = NULL;
struct acpi_rsdt *acpi_rsdt = NULL;
struct acpi_xsdt *acpi_xsdt = NULL;

struct acpi_signature_map signature_map[] = {
        {
                (uint8_t *) "APIC",
                (void *) &acpi_madt,
                "Multiple APIC Description Table"
        }
};

static int rsdp_check(uint8_t *_rsdp)
{
        struct acpi_rsdp *rsdp = (struct acpi_rsdp *) _rsdp;
        uint8_t sum = 0;
        uint32_t i;

        for (i = 0; i < 20; i++)
                sum = (uint8_t) (sum + _rsdp[i]);

        if (sum)
                return 0; /* bad checksum */

        if (rsdp->revision == 0)
                return 1; /* ACPI 1.0 */

        for (; i < rsdp->length; i++)
                sum = (uint8_t) (sum + _rsdp[i]);

        return !sum;
}

int acpi_sdt_check(uint8_t *sdt)
{
        struct acpi_sdt_header *hdr = (struct acpi_sdt_header *) sdt;
        uint8_t sum = 0;
        unsigned int i;

        for (i = 0; i < hdr->length; i++)
                sum = (uint8_t) (sum + sdt[i]);

        return !sum;
}

static struct acpi_sdt_header *map_sdt(struct acpi_sdt_header *psdt)
{
        struct acpi_sdt_header *vhdr;
        struct acpi_sdt_header *vsdt;

        /* Start with mapping the header only. */
        vhdr = (struct acpi_sdt_header *) km_map((uintptr_t) psdt,
            sizeof(struct acpi_sdt_header), KM_NATURAL_ALIGNMENT,
            PAGE_READ | PAGE_NOT_CACHEABLE);

        /* Now we can map the entire structure. */
        vsdt = (struct acpi_sdt_header *) km_map((uintptr_t) psdt,
            vhdr->length, KM_NATURAL_ALIGNMENT,
            PAGE_WRITE | PAGE_NOT_CACHEABLE);

        // TODO: do not leak vtmp

        return vsdt;
}

static void configure_via_rsdt(void)
{
        size_t i;
        size_t j;
        size_t cnt = (acpi_rsdt->header.length - sizeof(struct acpi_sdt_header)) /
            sizeof(uint32_t);

        for (i = 0; i < cnt; i++) {
                for (j = 0; j < sizeof(signature_map) /
                    sizeof(struct acpi_signature_map); j++) {
                        struct acpi_sdt_header *hdr =
                            (struct acpi_sdt_header *) (sysarg_t) acpi_rsdt->entry[i];

                        struct acpi_sdt_header *vhdr = map_sdt(hdr);
                        if (CMP_SIGNATURE(vhdr->signature, signature_map[j].signature)) {
                                if (!acpi_sdt_check((uint8_t *) vhdr))
                                        break;

                                *signature_map[j].sdt_ptr = vhdr;
                                LOG("%p: ACPI %s", *signature_map[j].sdt_ptr,
                                    signature_map[j].description);
                        }
                }
        }
}

static void configure_via_xsdt(void)
{
        size_t i;
        size_t j;
        size_t cnt = (acpi_xsdt->header.length - sizeof(struct acpi_sdt_header)) /
            sizeof(uint64_t);

        for (i = 0; i < cnt; i++) {
                for (j = 0; j < sizeof(signature_map) /
                    sizeof(struct acpi_signature_map); j++) {
                        struct acpi_sdt_header *hdr =
                            (struct acpi_sdt_header *) ((uintptr_t) acpi_xsdt->entry[i]);

                        struct acpi_sdt_header *vhdr = map_sdt(hdr);
                        if (CMP_SIGNATURE(vhdr->signature, signature_map[j].signature)) {
                                if (!acpi_sdt_check((uint8_t *) vhdr))
                                        break;

                                *signature_map[j].sdt_ptr = vhdr;
                                LOG("%p: ACPI %s", *signature_map[j].sdt_ptr,
                                    signature_map[j].description);
                        }
                }
        }
}

static uint8_t *search_rsdp(uint8_t *base, size_t len)
{
        for (size_t i = 0; i < len; i += 16) {
                if (!__builtin_memcmp(&base[i], RSDP_SIGNATURE, 8) &&
                    rsdp_check(&base[i]))
                        return &base[i];
        }

        return NULL;
}

void acpi_init(void)
{
        /*
         * Find Root System Description Pointer
         * 1. search first 1K of EBDA
         * 2. search 128K starting at 0xe0000
         */

        uint8_t *rsdp = NULL;

        if (ebda)
                rsdp = search_rsdp((uint8_t *) PA2KA(ebda), 1024);

        if (!rsdp)
                rsdp = search_rsdp((uint8_t *) PA2KA(0xe0000), 128 * 1024);

        if (!rsdp)
                return;

        acpi_rsdp = (struct acpi_rsdp *) rsdp;

        LOG("%p: ACPI Root System Description Pointer", acpi_rsdp);

        uintptr_t acpi_rsdt_p = (uintptr_t) acpi_rsdp->rsdt_address;
        uintptr_t acpi_xsdt_p = 0;

        if (acpi_rsdp->revision)
                acpi_xsdt_p = (uintptr_t) acpi_rsdp->xsdt_address;

        if (acpi_rsdt_p)
                acpi_rsdt = (struct acpi_rsdt *) map_sdt(
                    (struct acpi_sdt_header *) acpi_rsdt_p);

        if (acpi_xsdt_p)
                acpi_xsdt = (struct acpi_xsdt *) map_sdt(
                    (struct acpi_sdt_header *) acpi_xsdt_p);

        if ((acpi_rsdt) && (!acpi_sdt_check((uint8_t *) acpi_rsdt))) {
                log(LF_ARCH, LVL_ERROR, "RSDT: bad checksum");
                return;
        }

        if ((acpi_xsdt) && (!acpi_sdt_check((uint8_t *) acpi_xsdt))) {
                log(LF_ARCH, LVL_ERROR, "XSDT: bad checksum");
                return;
        }

        if (acpi_xsdt)
                configure_via_xsdt();
        else if (acpi_rsdt)
                configure_via_rsdt();
}

/** @}
 */