/*-
 * Copyright (c) 2017 The FreeBSD Foundation
 * All rights reserved.
 * Copyright (c) 2018, 2019 Intel Corporation
 *
 * This software was developed by Konstantin Belousov <kib@FreeBSD.org>
 * under sponsorship from the FreeBSD Foundation.
 *
 * 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 AUTHOR 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 AUTHOR 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.
 */

#include <sys/cdefs.h>
#include "opt_acpi.h"
#include "opt_ddb.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bio.h>
#include <sys/bitstring.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/sbuf.h>
#include <sys/sysctl.h>
#include <sys/uuid.h>

#include <contrib/dev/acpica/include/acpi.h>
#include <contrib/dev/acpica/include/accommon.h>
#include <contrib/dev/acpica/include/acuuid.h>
#include <dev/acpica/acpivar.h>

#include <dev/nvdimm/nvdimm_var.h>

#define _COMPONENT      ACPI_OEM
ACPI_MODULE_NAME("NVDIMM")

static struct uuid intel_nvdimm_dsm_uuid =
    {0x4309AC30,0x0D11,0x11E4,0x91,0x91,{0x08,0x00,0x20,0x0C,0x9A,0x66}};
#define INTEL_NVDIMM_DSM_REV 1
#define INTEL_NVDIMM_DSM_GET_LABEL_SIZE 4
#define INTEL_NVDIMM_DSM_GET_LABEL_DATA 5

MALLOC_DEFINE(M_NVDIMM, "nvdimm", "NVDIMM driver memory");

static int
read_label_area_size(struct nvdimm_dev *nv)
{
        ACPI_OBJECT *result_buffer;
        ACPI_HANDLE handle;
        ACPI_STATUS status;
        ACPI_BUFFER result;
        uint32_t *out;
        int error;

        handle = nvdimm_root_get_acpi_handle(nv->nv_dev);
        if (handle == NULL)
                return (ENODEV);
        result.Length = ACPI_ALLOCATE_BUFFER;
        result.Pointer = NULL;
        status = acpi_EvaluateDSM(handle, (uint8_t *)&intel_nvdimm_dsm_uuid,
            INTEL_NVDIMM_DSM_REV, INTEL_NVDIMM_DSM_GET_LABEL_SIZE, NULL,
            &result);
        error = ENXIO;
        if (ACPI_SUCCESS(status) && result.Pointer != NULL &&
            result.Length >= sizeof(ACPI_OBJECT)) {
                result_buffer = result.Pointer;
                if (result_buffer->Type == ACPI_TYPE_BUFFER &&
                    result_buffer->Buffer.Length >= 12) {
                        out = (uint32_t *)result_buffer->Buffer.Pointer;
                        nv->label_area_size = out[1];
                        nv->max_label_xfer = out[2];
                        error = 0;
                }
        }
        if (result.Pointer != NULL)
                AcpiOsFree(result.Pointer);
        return (error);
}

static int
read_label_area(struct nvdimm_dev *nv, uint8_t *dest, off_t offset,
    off_t length)
{
        ACPI_BUFFER result;
        ACPI_HANDLE handle;
        ACPI_OBJECT params_pkg, params_buf, *result_buf;
        ACPI_STATUS status;
        uint32_t params[2];
        off_t to_read;
        int error;

        error = 0;
        handle = nvdimm_root_get_acpi_handle(nv->nv_dev);
        if (offset < 0 || length <= 0 ||
            offset + length > nv->label_area_size ||
            handle == NULL)
                return (ENODEV);
        params_pkg.Type = ACPI_TYPE_PACKAGE;
        params_pkg.Package.Count = 1;
        params_pkg.Package.Elements = &params_buf;
        params_buf.Type = ACPI_TYPE_BUFFER;
        params_buf.Buffer.Length = sizeof(params);
        params_buf.Buffer.Pointer = (UINT8 *)params;
        while (length > 0) {
                to_read = MIN(length, nv->max_label_xfer);
                params[0] = offset;
                params[1] = to_read;
                result.Length = ACPI_ALLOCATE_BUFFER;
                result.Pointer = NULL;
                status = acpi_EvaluateDSM(handle,
                    (uint8_t *)&intel_nvdimm_dsm_uuid, INTEL_NVDIMM_DSM_REV,
                    INTEL_NVDIMM_DSM_GET_LABEL_DATA, &params_pkg, &result);
                if (ACPI_FAILURE(status) ||
                    result.Length < sizeof(ACPI_OBJECT) ||
                    result.Pointer == NULL) {
                        error = ENXIO;
                        break;
                }
                result_buf = (ACPI_OBJECT *)result.Pointer;
                if (result_buf->Type != ACPI_TYPE_BUFFER ||
                    result_buf->Buffer.Pointer == NULL ||
                    result_buf->Buffer.Length != 4 + to_read ||
                    ((uint16_t *)result_buf->Buffer.Pointer)[0] != 0) {
                        error = ENXIO;
                        break;
                }
                bcopy(result_buf->Buffer.Pointer + 4, dest, to_read);
                dest += to_read;
                offset += to_read;
                length -= to_read;
                if (result.Pointer != NULL) {
                        AcpiOsFree(result.Pointer);
                        result.Pointer = NULL;
                }
        }
        if (result.Pointer != NULL)
                AcpiOsFree(result.Pointer);
        return (error);
}

static uint64_t
fletcher64(const void *data, size_t length)
{
        size_t i;
        uint32_t a, b;
        const uint32_t *d;

        a = 0;
        b = 0;
        d = (const uint32_t *)data;
        length = length / sizeof(uint32_t);
        for (i = 0; i < length; i++) {
                a += d[i];
                b += a;
        }
        return ((uint64_t)b << 32 | a);
}

static bool
label_index_is_valid(struct nvdimm_label_index *index, uint32_t max_labels,
    size_t size, size_t offset)
{
        uint64_t checksum;

        index = (struct nvdimm_label_index *)((uint8_t *)index + size * offset);
        if (strcmp(index->signature, NVDIMM_INDEX_BLOCK_SIGNATURE) != 0)
                return false;
        checksum = index->checksum;
        index->checksum = 0;
        if (checksum != fletcher64(index, size) ||
            index->this_offset != size * offset || index->this_size != size ||
            index->other_offset != size * (offset == 0 ? 1 : 0) ||
            index->seq == 0 || index->seq > 3 || index->slot_cnt > max_labels ||
            index->label_size != 1)
                return false;
        return true;
}

static int
read_label(struct nvdimm_dev *nv, int num)
{
        struct nvdimm_label_entry *entry, *i, *next;
        uint64_t checksum;
        off_t offset;
        int error;

        offset = nv->label_index->label_offset +
            num * (128 << nv->label_index->label_size);
        entry = malloc(sizeof(*entry), M_NVDIMM, M_WAITOK);
        error = read_label_area(nv, (uint8_t *)&entry->label, offset,
            sizeof(struct nvdimm_label));
        if (error != 0) {
                free(entry, M_NVDIMM);
                return (error);
        }
        checksum = entry->label.checksum;
        entry->label.checksum = 0;
        if (checksum != fletcher64(&entry->label, sizeof(entry->label)) ||
            entry->label.slot != num) {
                free(entry, M_NVDIMM);
                return (ENXIO);
        }

        /* Insertion ordered by dimm_phys_addr */
        if (SLIST_EMPTY(&nv->labels) ||
            entry->label.dimm_phys_addr <=
            SLIST_FIRST(&nv->labels)->label.dimm_phys_addr) {
                SLIST_INSERT_HEAD(&nv->labels, entry, link);
                return (0);
        }
        SLIST_FOREACH_SAFE(i, &nv->labels, link, next) {
                if (next == NULL ||
                    entry->label.dimm_phys_addr <= next->label.dimm_phys_addr) {
                        SLIST_INSERT_AFTER(i, entry, link);
                        return (0);
                }
        }
        __assert_unreachable();
}

static int
read_labels(struct nvdimm_dev *nv)
{
        struct nvdimm_label_index *indices, *index1;
        size_t index_size, num_labels;
        int error, n;
        bool index_0_valid, index_1_valid;

        for (index_size = 256; ; index_size += 256) {
                num_labels = 8 * (index_size -
                    sizeof(struct nvdimm_label_index));
                if (index_size + num_labels * sizeof(struct nvdimm_label) >=
                    nv->label_area_size)
                        break;
        }
        num_labels = (nv->label_area_size - index_size) /
            sizeof(struct nvdimm_label);
        indices = malloc(2 * index_size, M_NVDIMM, M_WAITOK);
        index1 = (void *)((uint8_t *)indices + index_size);
        error = read_label_area(nv, (void *)indices, 0, 2 * index_size);
        if (error != 0) {
                free(indices, M_NVDIMM);
                return (error);
        }
        index_0_valid = label_index_is_valid(indices, num_labels, index_size,
            0);
        index_1_valid = label_index_is_valid(indices, num_labels, index_size,
            1);
        if (!index_0_valid && !index_1_valid) {
                free(indices, M_NVDIMM);
                return (ENXIO);
        }
        if (index_0_valid && index_1_valid) {
                if (((int)indices->seq - (int)index1->seq + 3) % 3 == 1) {
                        /* index 0 was more recently updated */
                        index_1_valid = false;
                } else {
                        /*
                         * either index 1 was more recently updated,
                         * or the sequence numbers are equal, in which
                         * case the specification says the block with
                         * the higher offset is to be treated as valid
                         */
                        index_0_valid = false;
                }
        }
        nv->label_index = malloc(index_size, M_NVDIMM, M_WAITOK);
        bcopy(index_0_valid ? indices : index1, nv->label_index, index_size);
        free(indices, M_NVDIMM);
        bit_ffc_at((bitstr_t *)nv->label_index->free, 0,
            nv->label_index->slot_cnt, &n);
        while (n >= 0) {
                read_label(nv, n);
                bit_ffc_at((bitstr_t *)nv->label_index->free, n + 1,
                    nv->label_index->slot_cnt, &n);
        }
        return (0);
}

static int
nvdimm_probe(device_t dev)
{

        return (BUS_PROBE_NOWILDCARD);
}

static int
nvdimm_attach(device_t dev)
{
        struct nvdimm_dev *nv;
        struct sysctl_ctx_list *ctx;
        struct sysctl_oid *oid;
        struct sysctl_oid_list *children;
        struct sbuf *sb;
        ACPI_TABLE_NFIT *nfitbl;
        ACPI_STATUS status;
        ACPI_NFIT_MEMORY_MAP **maps;
        int error, i, num_maps;
        uint16_t flags;

        nv = device_get_softc(dev);
        ctx = device_get_sysctl_ctx(dev);
        oid = device_get_sysctl_tree(dev);
        children = SYSCTL_CHILDREN(oid);
        MPASS(nvdimm_root_get_acpi_handle(dev) != NULL);
        nv->nv_dev = dev;
        nv->nv_handle = nvdimm_root_get_device_handle(dev);

        status = AcpiGetTable(ACPI_SIG_NFIT, 1, (ACPI_TABLE_HEADER **)&nfitbl);
        if (ACPI_FAILURE(status)) {
                if (bootverbose)
                        device_printf(dev, "cannot get NFIT\n");
                return (ENXIO);
        }
        acpi_nfit_get_flush_addrs(nfitbl, nv->nv_handle, &nv->nv_flush_addr,
            &nv->nv_flush_addr_cnt);

        /*
         * Each NVDIMM should have at least one memory map associated with it.
         * If any of the maps have one of the error flags set, reflect that in
         * the overall status.
         */
        acpi_nfit_get_memory_maps_by_dimm(nfitbl, nv->nv_handle, &maps,
            &num_maps);
        if (num_maps == 0) {
                free(nv->nv_flush_addr, M_NVDIMM);
                free(maps, M_NVDIMM);
                device_printf(dev, "cannot find memory map\n");
                return (ENXIO);
        }
        flags = 0;
        for (i = 0; i < num_maps; i++) {
                flags |= maps[i]->Flags;
        }
        free(maps, M_NVDIMM);

        /* sbuf_new_auto(9) is M_WAITOK; no need to check for NULL. */
        sb = sbuf_new_auto();
        (void) sbuf_printf(sb, "0x%b", flags,
            "\20"
            "\001SAVE_FAILED"
            "\002RESTORE_FAILED"
            "\003FLUSH_FAILED"
            "\004NOT_ARMED"
            "\005HEALTH_OBSERVED"
            "\006HEALTH_ENABLED"
            "\007MAP_FAILED");
        error = sbuf_finish(sb);
        if (error != 0) {
                sbuf_delete(sb);
                free(nv->nv_flush_addr, M_NVDIMM);
                device_printf(dev, "cannot convert flags to string\n");
                return (error);
        }
        /* strdup(9) is M_WAITOK; no need to check for NULL. */
        nv->nv_flags_str = strdup(sbuf_data(sb), M_NVDIMM);
        sbuf_delete(sb);
        SYSCTL_ADD_STRING(ctx, children, OID_AUTO, "flags",
            CTLFLAG_RD | CTLFLAG_MPSAFE, nv->nv_flags_str, 0,
            "NVDIMM State Flags");
        /*
         * Anything other than HEALTH_ENABLED indicates a fault condition of
         * some kind, so log if that's seen.
         */
        if ((flags & ~ACPI_NFIT_MEM_HEALTH_ENABLED) != 0)
                device_printf(dev, "flags: %s\n", nv->nv_flags_str);

        AcpiPutTable(&nfitbl->Header);
        error = read_label_area_size(nv);
        if (error == 0) {
                /*
                 * Ignoring errors reading labels. Not all NVDIMMs
                 * support labels and namespaces.
                 */
                read_labels(nv);
        }
        return (0);
}

static int
nvdimm_detach(device_t dev)
{
        struct nvdimm_dev *nv;
        struct nvdimm_label_entry *label, *next;

        nv = device_get_softc(dev);
        free(nv->nv_flags_str, M_NVDIMM);
        free(nv->nv_flush_addr, M_NVDIMM);
        free(nv->label_index, M_NVDIMM);
        SLIST_FOREACH_SAFE(label, &nv->labels, link, next) {
                SLIST_REMOVE_HEAD(&nv->labels, link);
                free(label, M_NVDIMM);
        }
        return (0);
}

static int
nvdimm_suspend(device_t dev)
{

        return (0);
}

static int
nvdimm_resume(device_t dev)
{

        return (0);
}

static device_method_t nvdimm_methods[] = {
        DEVMETHOD(device_probe, nvdimm_probe),
        DEVMETHOD(device_attach, nvdimm_attach),
        DEVMETHOD(device_detach, nvdimm_detach),
        DEVMETHOD(device_suspend, nvdimm_suspend),
        DEVMETHOD(device_resume, nvdimm_resume),
        DEVMETHOD_END
};

static driver_t nvdimm_driver = {
        "nvdimm",
        nvdimm_methods,
        sizeof(struct nvdimm_dev),
};

struct nvdimm_dev *
nvdimm_find_by_handle(nfit_handle_t nv_handle)
{
        struct nvdimm_dev *res;
        device_t *dimms;
        int i, error, num_dimms;

        res = NULL;
        error = devclass_get_devices(devclass_find(nvdimm_driver.name), &dimms,
            &num_dimms);
        if (error != 0)
                return (NULL);
        for (i = 0; i < num_dimms; i++) {
                if (nvdimm_root_get_device_handle(dimms[i]) == nv_handle) {
                        res = device_get_softc(dimms[i]);
                        break;
                }
        }
        free(dimms, M_TEMP);
        return (res);
}

DRIVER_MODULE(nvdimm, nvdimm_acpi_root, nvdimm_driver, NULL, NULL);
MODULE_DEPEND(nvdimm, acpi, 1, 1, 1);