// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright 2012 IBM Corporation
 *
 * Author: Ashley Lai <ashleydlai@gmail.com>
 *         Nayna Jain <nayna@linux.vnet.ibm.com>
 *
 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
 *
 * Read the event log created by the firmware on PPC64
 */

#include <linux/device.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_reserved_mem.h>
#include <linux/tpm_eventlog.h>

#include "../tpm.h"
#include "common.h"

static int tpm_read_log_memory_region(struct tpm_chip *chip)
{
        struct resource res;
        int rc;

        rc = of_reserved_mem_region_to_resource(chip->dev.parent->of_node, 0, &res);
        if (rc)
                return rc;

        chip->log.bios_event_log = devm_memremap(&chip->dev, res.start, resource_size(&res),
                                                 MEMREMAP_WB);
        if (IS_ERR(chip->log.bios_event_log))
                return -ENOMEM;

        chip->log.bios_event_log_end = chip->log.bios_event_log + resource_size(&res);

        return chip->flags & TPM_CHIP_FLAG_TPM2 ? EFI_TCG2_EVENT_LOG_FORMAT_TCG_2 :
                EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
}

int tpm_read_log_of(struct tpm_chip *chip)
{
        struct device_node *np;
        const u32 *sizep;
        const u64 *basep;
        struct tpm_bios_log *log;
        u32 size;
        u64 base;

        log = &chip->log;
        if (chip->dev.parent && chip->dev.parent->of_node)
                np = chip->dev.parent->of_node;
        else
                return -ENODEV;

        if (of_property_read_bool(np, "powered-while-suspended"))
                chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;

        sizep = of_get_property(np, "linux,sml-size", NULL);
        basep = of_get_property(np, "linux,sml-base", NULL);
        if (sizep == NULL && basep == NULL)
                return tpm_read_log_memory_region(chip);
        if (sizep == NULL || basep == NULL)
                return -EIO;

        /*
         * For both vtpm/tpm, firmware has log addr and log size in big
         * endian format. But in case of vtpm, there is a method called
         * sml-handover which is run during kernel init even before
         * device tree is setup. This sml-handover function takes care
         * of endianness and writes to sml-base and sml-size in little
         * endian format. For this reason, vtpm doesn't need conversion
         * but physical tpm needs the conversion.
         */
        if (of_property_match_string(np, "compatible", "IBM,vtpm") < 0 &&
            of_property_match_string(np, "compatible", "IBM,vtpm20") < 0) {
                size = be32_to_cpup((__force __be32 *)sizep);
                base = be64_to_cpup((__force __be64 *)basep);
        } else {
                size = *sizep;
                base = *basep;
        }

        if (size == 0) {
                dev_warn(&chip->dev, "%s: Event log area empty\n", __func__);
                return -EIO;
        }

        log->bios_event_log = devm_kmemdup(&chip->dev, __va(base), size, GFP_KERNEL);
        if (!log->bios_event_log)
                return -ENOMEM;

        log->bios_event_log_end = log->bios_event_log + size;

        if (chip->flags & TPM_CHIP_FLAG_TPM2)
                return EFI_TCG2_EVENT_LOG_FORMAT_TCG_2;
        return EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
}