/*      $NetBSD: apei_bert.c,v 1.1 2024/03/20 17:11:43 riastradh Exp $  */

/*-
* Copyright (c) 2024 The NetBSD Foundation, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``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 FOUNDATION OR CONTRIBUTORS
* 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.
*/

/*
* APEI BERT -- Boot Error Record Table
*
* https://uefi.org/specs/ACPI/6.5/18_Platform_Error_Interfaces.html#boot-error-source
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: apei_bert.c,v 1.1 2024/03/20 17:11:43 riastradh Exp $");

#include <sys/types.h>

#include <sys/systm.h>

#include <dev/acpi/acpivar.h>
#include <dev/acpi/apeivar.h>
#include <dev/acpi/apei_bertvar.h>

#define _COMPONENT      ACPI_RESOURCE_COMPONENT
ACPI_MODULE_NAME        ("apei")

/*
* apei_bert_attach(sc)
*
*      Scan the Boot Error Record Table for hardware errors that
*      happened early at boot or on the previous boot.
*/
void
apei_bert_attach(struct apei_softc *sc)
{
       const ACPI_TABLE_BERT *bert = sc->sc_tab.bert;
       struct apei_bert_softc *bsc = &sc->sc_bert;
       bool fatal = false;

       /*
        * Verify the table is large enough.
        */
       if (bert->Header.Length < sizeof(*bert)) {
               aprint_error_dev(sc->sc_dev, "BERT: truncated table:"
                   " %"PRIu32" < %zu bytes\n",
                   bert->Header.Length, sizeof(*bert));
               return;
       }

       /*
        * In verbose boots, print the BERT physical address and
        * length.  The operator might find this handy for dd'ing it
        * from /dev/mem, if allowed.
        */
       aprint_verbose_dev(sc->sc_dev, "BERT: 0x%x bytes at 0x%"PRIx64"\n",
           bert->RegionLength, bert->Address);

       /*
        * Verify the length is enough for a Generic Error Status Block
        * header, at least.
        */
       if (bert->RegionLength < sizeof(*bsc->bsc_gesb)) {
               aprint_error_dev(sc->sc_dev,
                   "BERT: truncated boot error region, %"PRIu32" < %zu bytes",
                   bert->RegionLength, sizeof(*bsc->bsc_gesb));
               return;
       }

       /*
        * Map the GESB and process it, but don't acknowledge it --
        * this is a one-time polled source; it won't (or at least,
        * shouldn't) change after boot.
        */
       bsc->bsc_gesb = AcpiOsMapMemory(bert->Address, bert->RegionLength);
       const uint32_t status = apei_gesb_report(sc, bsc->bsc_gesb,
           bert->RegionLength, "boot error record", &fatal);
       if (status == 0) {
               /*
                * If there were no boot errors, leave a note in dmesg
                * to this effect without cluttering up the console
                * unless you asked for it by `boot -v'.
                */
               aprint_verbose_dev(sc->sc_dev,
                   "BERT: no boot errors recorded\n");
       }

       /*
        * If the error was fatal, print a warning to the console.
        * Probably not actually fatal now since it is usually related
        * to early or previous boot.
        */
       if (fatal) {
               aprint_error_dev(sc->sc_dev, "BERT:"
                   " fatal pre-boot error recorded\n");
       }

       /* XXX expose content via sysctl? */
}

/*
* apei_bert_detach(sc)
*
*      Free any software resources associated with the Boot Error
*      Record Table.
*/
void
apei_bert_detach(struct apei_softc *sc)
{
       const ACPI_TABLE_BERT *bert = sc->sc_tab.bert;
       struct apei_bert_softc *bsc = &sc->sc_bert;

       if (bsc->bsc_gesb) {
               AcpiOsUnmapMemory(bsc->bsc_gesb, bert->RegionLength);
               bsc->bsc_gesb = NULL;
       }
}