/*
 * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 */
#include <linux/list_sort.h>
#include <linux/libnvdimm.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/ndctl.h>
#include <linux/sysfs.h>
#include <linux/delay.h>
#include <linux/list.h>
#include <linux/acpi.h>
#include <linux/sort.h>
#include <linux/io.h>
#include <linux/nd.h>
#include <asm/cacheflush.h>
#include <acpi/nfit.h>
#include "intel.h"
#include "nfit.h"

/*
 * For readq() and writeq() on 32-bit builds, the hi-lo, lo-hi order is
 * irrelevant.
 */
#include <linux/io-64-nonatomic-hi-lo.h>

static bool force_enable_dimms;
module_param(force_enable_dimms, bool, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(force_enable_dimms, "Ignore _STA (ACPI DIMM device) status");

static bool disable_vendor_specific;
module_param(disable_vendor_specific, bool, S_IRUGO);
MODULE_PARM_DESC(disable_vendor_specific,
                "Limit commands to the publicly specified set");

static unsigned long override_dsm_mask;
module_param(override_dsm_mask, ulong, S_IRUGO);
MODULE_PARM_DESC(override_dsm_mask, "Bitmask of allowed NVDIMM DSM functions");

static int default_dsm_family = -1;
module_param(default_dsm_family, int, S_IRUGO);
MODULE_PARM_DESC(default_dsm_family,
                "Try this DSM type first when identifying NVDIMM family");

static bool no_init_ars;
module_param(no_init_ars, bool, 0644);
MODULE_PARM_DESC(no_init_ars, "Skip ARS run at nfit init time");

static bool force_labels;
module_param(force_labels, bool, 0444);
MODULE_PARM_DESC(force_labels, "Opt-in to labels despite missing methods");

LIST_HEAD(acpi_descs);
DEFINE_MUTEX(acpi_desc_lock);

static struct workqueue_struct *nfit_wq;

struct nfit_table_prev {
        struct list_head spas;
        struct list_head memdevs;
        struct list_head dcrs;
        struct list_head bdws;
        struct list_head idts;
        struct list_head flushes;
};

static guid_t nfit_uuid[NFIT_UUID_MAX];

const guid_t *to_nfit_uuid(enum nfit_uuids id)
{
        return &nfit_uuid[id];
}
EXPORT_SYMBOL(to_nfit_uuid);

static struct acpi_device *to_acpi_dev(struct acpi_nfit_desc *acpi_desc)
{
        struct nvdimm_bus_descriptor *nd_desc = &acpi_desc->nd_desc;

        /*
         * If provider == 'ACPI.NFIT' we can assume 'dev' is a struct
         * acpi_device.
         */
        if (!nd_desc->provider_name
                        || strcmp(nd_desc->provider_name, "ACPI.NFIT") != 0)
                return NULL;

        return to_acpi_device(acpi_desc->dev);
}

static int xlat_bus_status(void *buf, unsigned int cmd, u32 status)
{
        struct nd_cmd_clear_error *clear_err;
        struct nd_cmd_ars_status *ars_status;
        u16 flags;

        switch (cmd) {
        case ND_CMD_ARS_CAP:
                if ((status & 0xffff) == NFIT_ARS_CAP_NONE)
                        return -ENOTTY;

                /* Command failed */
                if (status & 0xffff)
                        return -EIO;

                /* No supported scan types for this range */
                flags = ND_ARS_PERSISTENT | ND_ARS_VOLATILE;
                if ((status >> 16 & flags) == 0)
                        return -ENOTTY;
                return 0;
        case ND_CMD_ARS_START:
                /* ARS is in progress */
                if ((status & 0xffff) == NFIT_ARS_START_BUSY)
                        return -EBUSY;

                /* Command failed */
                if (status & 0xffff)
                        return -EIO;
                return 0;
        case ND_CMD_ARS_STATUS:
                ars_status = buf;
                /* Command failed */
                if (status & 0xffff)
                        return -EIO;
                /* Check extended status (Upper two bytes) */
                if (status == NFIT_ARS_STATUS_DONE)
                        return 0;

                /* ARS is in progress */
                if (status == NFIT_ARS_STATUS_BUSY)
                        return -EBUSY;

                /* No ARS performed for the current boot */
                if (status == NFIT_ARS_STATUS_NONE)
                        return -EAGAIN;

                /*
                 * ARS interrupted, either we overflowed or some other
                 * agent wants the scan to stop.  If we didn't overflow
                 * then just continue with the returned results.
                 */
                if (status == NFIT_ARS_STATUS_INTR) {
                        if (ars_status->out_length >= 40 && (ars_status->flags
                                                & NFIT_ARS_F_OVERFLOW))
                                return -ENOSPC;
                        return 0;
                }

                /* Unknown status */
                if (status >> 16)
                        return -EIO;
                return 0;
        case ND_CMD_CLEAR_ERROR:
                clear_err = buf;
                if (status & 0xffff)
                        return -EIO;
                if (!clear_err->cleared)
                        return -EIO;
                if (clear_err->length > clear_err->cleared)
                        return clear_err->cleared;
                return 0;
        default:
                break;
        }

        /* all other non-zero status results in an error */
        if (status)
                return -EIO;
        return 0;
}

#define ACPI_LABELS_LOCKED 3

static int xlat_nvdimm_status(struct nvdimm *nvdimm, void *buf, unsigned int cmd,
                u32 status)
{
        struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);

        switch (cmd) {
        case ND_CMD_GET_CONFIG_SIZE:
                /*
                 * In the _LSI, _LSR, _LSW case the locked status is
                 * communicated via the read/write commands
                 */
                if (test_bit(NFIT_MEM_LSR, &nfit_mem->flags))
                        break;

                if (status >> 16 & ND_CONFIG_LOCKED)
                        return -EACCES;
                break;
        case ND_CMD_GET_CONFIG_DATA:
                if (test_bit(NFIT_MEM_LSR, &nfit_mem->flags)
                                && status == ACPI_LABELS_LOCKED)
                        return -EACCES;
                break;
        case ND_CMD_SET_CONFIG_DATA:
                if (test_bit(NFIT_MEM_LSW, &nfit_mem->flags)
                                && status == ACPI_LABELS_LOCKED)
                        return -EACCES;
                break;
        default:
                break;
        }

        /* all other non-zero status results in an error */
        if (status)
                return -EIO;
        return 0;
}

static int xlat_status(struct nvdimm *nvdimm, void *buf, unsigned int cmd,
                u32 status)
{
        if (!nvdimm)
                return xlat_bus_status(buf, cmd, status);
        return xlat_nvdimm_status(nvdimm, buf, cmd, status);
}

/* convert _LS{I,R} packages to the buffer object acpi_nfit_ctl expects */
static union acpi_object *pkg_to_buf(union acpi_object *pkg)
{
        int i;
        void *dst;
        size_t size = 0;
        union acpi_object *buf = NULL;

        if (pkg->type != ACPI_TYPE_PACKAGE) {
                WARN_ONCE(1, "BIOS bug, unexpected element type: %d\n",
                                pkg->type);
                goto err;
        }

        for (i = 0; i < pkg->package.count; i++) {
                union acpi_object *obj = &pkg->package.elements[i];

                if (obj->type == ACPI_TYPE_INTEGER)
                        size += 4;
                else if (obj->type == ACPI_TYPE_BUFFER)
                        size += obj->buffer.length;
                else {
                        WARN_ONCE(1, "BIOS bug, unexpected element type: %d\n",
                                        obj->type);
                        goto err;
                }
        }

        buf = ACPI_ALLOCATE(sizeof(*buf) + size);
        if (!buf)
                goto err;

        dst = buf + 1;
        buf->type = ACPI_TYPE_BUFFER;
        buf->buffer.length = size;
        buf->buffer.pointer = dst;
        for (i = 0; i < pkg->package.count; i++) {
                union acpi_object *obj = &pkg->package.elements[i];

                if (obj->type == ACPI_TYPE_INTEGER) {
                        memcpy(dst, &obj->integer.value, 4);
                        dst += 4;
                } else if (obj->type == ACPI_TYPE_BUFFER) {
                        memcpy(dst, obj->buffer.pointer, obj->buffer.length);
                        dst += obj->buffer.length;
                }
        }
err:
        ACPI_FREE(pkg);
        return buf;
}

static union acpi_object *int_to_buf(union acpi_object *integer)
{
        union acpi_object *buf = ACPI_ALLOCATE(sizeof(*buf) + 4);
        void *dst = NULL;

        if (!buf)
                goto err;

        if (integer->type != ACPI_TYPE_INTEGER) {
                WARN_ONCE(1, "BIOS bug, unexpected element type: %d\n",
                                integer->type);
                goto err;
        }

        dst = buf + 1;
        buf->type = ACPI_TYPE_BUFFER;
        buf->buffer.length = 4;
        buf->buffer.pointer = dst;
        memcpy(dst, &integer->integer.value, 4);
err:
        ACPI_FREE(integer);
        return buf;
}

static union acpi_object *acpi_label_write(acpi_handle handle, u32 offset,
                u32 len, void *data)
{
        acpi_status rc;
        struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
        struct acpi_object_list input = {
                .count = 3,
                .pointer = (union acpi_object []) {
                        [0] = {
                                .integer.type = ACPI_TYPE_INTEGER,
                                .integer.value = offset,
                        },
                        [1] = {
                                .integer.type = ACPI_TYPE_INTEGER,
                                .integer.value = len,
                        },
                        [2] = {
                                .buffer.type = ACPI_TYPE_BUFFER,
                                .buffer.pointer = data,
                                .buffer.length = len,
                        },
                },
        };

        rc = acpi_evaluate_object(handle, "_LSW", &input, &buf);
        if (ACPI_FAILURE(rc))
                return NULL;
        return int_to_buf(buf.pointer);
}

static union acpi_object *acpi_label_read(acpi_handle handle, u32 offset,
                u32 len)
{
        acpi_status rc;
        struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
        struct acpi_object_list input = {
                .count = 2,
                .pointer = (union acpi_object []) {
                        [0] = {
                                .integer.type = ACPI_TYPE_INTEGER,
                                .integer.value = offset,
                        },
                        [1] = {
                                .integer.type = ACPI_TYPE_INTEGER,
                                .integer.value = len,
                        },
                },
        };

        rc = acpi_evaluate_object(handle, "_LSR", &input, &buf);
        if (ACPI_FAILURE(rc))
                return NULL;
        return pkg_to_buf(buf.pointer);
}

static union acpi_object *acpi_label_info(acpi_handle handle)
{
        acpi_status rc;
        struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };

        rc = acpi_evaluate_object(handle, "_LSI", NULL, &buf);
        if (ACPI_FAILURE(rc))
                return NULL;
        return pkg_to_buf(buf.pointer);
}

static u8 nfit_dsm_revid(unsigned family, unsigned func)
{
        static const u8 revid_table[NVDIMM_FAMILY_MAX+1][32] = {
                [NVDIMM_FAMILY_INTEL] = {
                        [NVDIMM_INTEL_GET_MODES] = 2,
                        [NVDIMM_INTEL_GET_FWINFO] = 2,
                        [NVDIMM_INTEL_START_FWUPDATE] = 2,
                        [NVDIMM_INTEL_SEND_FWUPDATE] = 2,
                        [NVDIMM_INTEL_FINISH_FWUPDATE] = 2,
                        [NVDIMM_INTEL_QUERY_FWUPDATE] = 2,
                        [NVDIMM_INTEL_SET_THRESHOLD] = 2,
                        [NVDIMM_INTEL_INJECT_ERROR] = 2,
                        [NVDIMM_INTEL_GET_SECURITY_STATE] = 2,
                        [NVDIMM_INTEL_SET_PASSPHRASE] = 2,
                        [NVDIMM_INTEL_DISABLE_PASSPHRASE] = 2,
                        [NVDIMM_INTEL_UNLOCK_UNIT] = 2,
                        [NVDIMM_INTEL_FREEZE_LOCK] = 2,
                        [NVDIMM_INTEL_SECURE_ERASE] = 2,
                        [NVDIMM_INTEL_OVERWRITE] = 2,
                        [NVDIMM_INTEL_QUERY_OVERWRITE] = 2,
                        [NVDIMM_INTEL_SET_MASTER_PASSPHRASE] = 2,
                        [NVDIMM_INTEL_MASTER_SECURE_ERASE] = 2,
                },
        };
        u8 id;

        if (family > NVDIMM_FAMILY_MAX)
                return 0;
        if (func > 31)
                return 0;
        id = revid_table[family][func];
        if (id == 0)
                return 1; /* default */
        return id;
}

static int cmd_to_func(struct nfit_mem *nfit_mem, unsigned int cmd,
                struct nd_cmd_pkg *call_pkg)
{
        if (call_pkg) {
                int i;

                if (nfit_mem && nfit_mem->family != call_pkg->nd_family)
                        return -ENOTTY;

                for (i = 0; i < ARRAY_SIZE(call_pkg->nd_reserved2); i++)
                        if (call_pkg->nd_reserved2[i])
                                return -EINVAL;
                return call_pkg->nd_command;
        }

        /* In the !call_pkg case, bus commands == bus functions */
        if (!nfit_mem)
                return cmd;

        /* Linux ND commands == NVDIMM_FAMILY_INTEL function numbers */
        if (nfit_mem->family == NVDIMM_FAMILY_INTEL)
                return cmd;

        /*
         * Force function number validation to fail since 0 is never
         * published as a valid function in dsm_mask.
         */
        return 0;
}

static bool payload_dumpable(struct nvdimm *nvdimm, unsigned int func)
{
        struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);

        if (nfit_mem && nfit_mem->family == NVDIMM_FAMILY_INTEL
                        && func >= NVDIMM_INTEL_GET_SECURITY_STATE
                        && func <= NVDIMM_INTEL_MASTER_SECURE_ERASE)
                return IS_ENABLED(CONFIG_NFIT_SECURITY_DEBUG);
        return true;
}

int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
                unsigned int cmd, void *buf, unsigned int buf_len, int *cmd_rc)
{
        struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);
        struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
        union acpi_object in_obj, in_buf, *out_obj;
        const struct nd_cmd_desc *desc = NULL;
        struct device *dev = acpi_desc->dev;
        struct nd_cmd_pkg *call_pkg = NULL;
        const char *cmd_name, *dimm_name;
        unsigned long cmd_mask, dsm_mask;
        u32 offset, fw_status = 0;
        acpi_handle handle;
        const guid_t *guid;
        int func, rc, i;

        if (cmd_rc)
                *cmd_rc = -EINVAL;

        if (cmd == ND_CMD_CALL)
                call_pkg = buf;
        func = cmd_to_func(nfit_mem, cmd, call_pkg);
        if (func < 0)
                return func;

        if (nvdimm) {
                struct acpi_device *adev = nfit_mem->adev;

                if (!adev)
                        return -ENOTTY;

                dimm_name = nvdimm_name(nvdimm);
                cmd_name = nvdimm_cmd_name(cmd);
                cmd_mask = nvdimm_cmd_mask(nvdimm);
                dsm_mask = nfit_mem->dsm_mask;
                desc = nd_cmd_dimm_desc(cmd);
                guid = to_nfit_uuid(nfit_mem->family);
                handle = adev->handle;
        } else {
                struct acpi_device *adev = to_acpi_dev(acpi_desc);

                cmd_name = nvdimm_bus_cmd_name(cmd);
                cmd_mask = nd_desc->cmd_mask;
                dsm_mask = nd_desc->bus_dsm_mask;
                desc = nd_cmd_bus_desc(cmd);
                guid = to_nfit_uuid(NFIT_DEV_BUS);
                handle = adev->handle;
                dimm_name = "bus";
        }

        if (!desc || (cmd && (desc->out_num + desc->in_num == 0)))
                return -ENOTTY;

        /*
         * Check for a valid command.  For ND_CMD_CALL, we also have to
         * make sure that the DSM function is supported.
         */
        if (cmd == ND_CMD_CALL && !test_bit(func, &dsm_mask))
                return -ENOTTY;
        else if (!test_bit(cmd, &cmd_mask))
                return -ENOTTY;

        in_obj.type = ACPI_TYPE_PACKAGE;
        in_obj.package.count = 1;
        in_obj.package.elements = &in_buf;
        in_buf.type = ACPI_TYPE_BUFFER;
        in_buf.buffer.pointer = buf;
        in_buf.buffer.length = 0;

        /* libnvdimm has already validated the input envelope */
        for (i = 0; i < desc->in_num; i++)
                in_buf.buffer.length += nd_cmd_in_size(nvdimm, cmd, desc,
                                i, buf);

        if (call_pkg) {
                /* skip over package wrapper */
                in_buf.buffer.pointer = (void *) &call_pkg->nd_payload;
                in_buf.buffer.length = call_pkg->nd_size_in;
        }

        dev_dbg(dev, "%s cmd: %d: func: %d input length: %d\n",
                dimm_name, cmd, func, in_buf.buffer.length);
        if (payload_dumpable(nvdimm, func))
                print_hex_dump_debug("nvdimm in  ", DUMP_PREFIX_OFFSET, 4, 4,
                                in_buf.buffer.pointer,
                                min_t(u32, 256, in_buf.buffer.length), true);

        /* call the BIOS, prefer the named methods over _DSM if available */
        if (nvdimm && cmd == ND_CMD_GET_CONFIG_SIZE
                        && test_bit(NFIT_MEM_LSR, &nfit_mem->flags))
                out_obj = acpi_label_info(handle);
        else if (nvdimm && cmd == ND_CMD_GET_CONFIG_DATA
                        && test_bit(NFIT_MEM_LSR, &nfit_mem->flags)) {
                struct nd_cmd_get_config_data_hdr *p = buf;

                out_obj = acpi_label_read(handle, p->in_offset, p->in_length);
        } else if (nvdimm && cmd == ND_CMD_SET_CONFIG_DATA
                        && test_bit(NFIT_MEM_LSW, &nfit_mem->flags)) {
                struct nd_cmd_set_config_hdr *p = buf;

                out_obj = acpi_label_write(handle, p->in_offset, p->in_length,
                                p->in_buf);
        } else {
                u8 revid;

                if (nvdimm)
                        revid = nfit_dsm_revid(nfit_mem->family, func);
                else
                        revid = 1;
                out_obj = acpi_evaluate_dsm(handle, guid, revid, func, &in_obj);
        }

        if (!out_obj) {
                dev_dbg(dev, "%s _DSM failed cmd: %s\n", dimm_name, cmd_name);
                return -EINVAL;
        }

        if (out_obj->type != ACPI_TYPE_BUFFER) {
                dev_dbg(dev, "%s unexpected output object type cmd: %s type: %d\n",
                                dimm_name, cmd_name, out_obj->type);
                rc = -EINVAL;
                goto out;
        }

        dev_dbg(dev, "%s cmd: %s output length: %d\n", dimm_name,
                        cmd_name, out_obj->buffer.length);
        print_hex_dump_debug(cmd_name, DUMP_PREFIX_OFFSET, 4, 4,
                        out_obj->buffer.pointer,
                        min_t(u32, 128, out_obj->buffer.length), true);

        if (call_pkg) {
                call_pkg->nd_fw_size = out_obj->buffer.length;
                memcpy(call_pkg->nd_payload + call_pkg->nd_size_in,
                        out_obj->buffer.pointer,
                        min(call_pkg->nd_fw_size, call_pkg->nd_size_out));

                ACPI_FREE(out_obj);
                /*
                 * Need to support FW function w/o known size in advance.
                 * Caller can determine required size based upon nd_fw_size.
                 * If we return an error (like elsewhere) then caller wouldn't
                 * be able to rely upon data returned to make calculation.
                 */
                if (cmd_rc)
                        *cmd_rc = 0;
                return 0;
        }

        for (i = 0, offset = 0; i < desc->out_num; i++) {
                u32 out_size = nd_cmd_out_size(nvdimm, cmd, desc, i, buf,
                                (u32 *) out_obj->buffer.pointer,
                                out_obj->buffer.length - offset);

                if (offset + out_size > out_obj->buffer.length) {
                        dev_dbg(dev, "%s output object underflow cmd: %s field: %d\n",
                                        dimm_name, cmd_name, i);
                        break;
                }

                if (in_buf.buffer.length + offset + out_size > buf_len) {
                        dev_dbg(dev, "%s output overrun cmd: %s field: %d\n",
                                        dimm_name, cmd_name, i);
                        rc = -ENXIO;
                        goto out;
                }
                memcpy(buf + in_buf.buffer.length + offset,
                                out_obj->buffer.pointer + offset, out_size);
                offset += out_size;
        }

        /*
         * Set fw_status for all the commands with a known format to be
         * later interpreted by xlat_status().
         */
        if (i >= 1 && ((!nvdimm && cmd >= ND_CMD_ARS_CAP
                                        && cmd <= ND_CMD_CLEAR_ERROR)
                                || (nvdimm && cmd >= ND_CMD_SMART
                                        && cmd <= ND_CMD_VENDOR)))
                fw_status = *(u32 *) out_obj->buffer.pointer;

        if (offset + in_buf.buffer.length < buf_len) {
                if (i >= 1) {
                        /*
                         * status valid, return the number of bytes left
                         * unfilled in the output buffer
                         */
                        rc = buf_len - offset - in_buf.buffer.length;
                        if (cmd_rc)
                                *cmd_rc = xlat_status(nvdimm, buf, cmd,
                                                fw_status);
                } else {
                        dev_err(dev, "%s:%s underrun cmd: %s buf_len: %d out_len: %d\n",
                                        __func__, dimm_name, cmd_name, buf_len,
                                        offset);
                        rc = -ENXIO;
                }
        } else {
                rc = 0;
                if (cmd_rc)
                        *cmd_rc = xlat_status(nvdimm, buf, cmd, fw_status);
        }

 out:
        ACPI_FREE(out_obj);

        return rc;
}
EXPORT_SYMBOL_GPL(acpi_nfit_ctl);

static const char *spa_type_name(u16 type)
{
        static const char *to_name[] = {
                [NFIT_SPA_VOLATILE] = "volatile",
                [NFIT_SPA_PM] = "pmem",
                [NFIT_SPA_DCR] = "dimm-control-region",
                [NFIT_SPA_BDW] = "block-data-window",
                [NFIT_SPA_VDISK] = "volatile-disk",
                [NFIT_SPA_VCD] = "volatile-cd",
                [NFIT_SPA_PDISK] = "persistent-disk",
                [NFIT_SPA_PCD] = "persistent-cd",

        };

        if (type > NFIT_SPA_PCD)
                return "unknown";

        return to_name[type];
}

int nfit_spa_type(struct acpi_nfit_system_address *spa)
{
        int i;

        for (i = 0; i < NFIT_UUID_MAX; i++)
                if (guid_equal(to_nfit_uuid(i), (guid_t *)&spa->range_guid))
                        return i;
        return -1;
}

static bool add_spa(struct acpi_nfit_desc *acpi_desc,
                struct nfit_table_prev *prev,
                struct acpi_nfit_system_address *spa)
{
        struct device *dev = acpi_desc->dev;
        struct nfit_spa *nfit_spa;

        if (spa->header.length != sizeof(*spa))
                return false;

        list_for_each_entry(nfit_spa, &prev->spas, list) {
                if (memcmp(nfit_spa->spa, spa, sizeof(*spa)) == 0) {
                        list_move_tail(&nfit_spa->list, &acpi_desc->spas);
                        return true;
                }
        }

        nfit_spa = devm_kzalloc(dev, sizeof(*nfit_spa) + sizeof(*spa),
                        GFP_KERNEL);
        if (!nfit_spa)
                return false;
        INIT_LIST_HEAD(&nfit_spa->list);
        memcpy(nfit_spa->spa, spa, sizeof(*spa));
        list_add_tail(&nfit_spa->list, &acpi_desc->spas);
        dev_dbg(dev, "spa index: %d type: %s\n",
                        spa->range_index,
                        spa_type_name(nfit_spa_type(spa)));
        return true;
}

static bool add_memdev(struct acpi_nfit_desc *acpi_desc,
                struct nfit_table_prev *prev,
                struct acpi_nfit_memory_map *memdev)
{
        struct device *dev = acpi_desc->dev;
        struct nfit_memdev *nfit_memdev;

        if (memdev->header.length != sizeof(*memdev))
                return false;

        list_for_each_entry(nfit_memdev, &prev->memdevs, list)
                if (memcmp(nfit_memdev->memdev, memdev, sizeof(*memdev)) == 0) {
                        list_move_tail(&nfit_memdev->list, &acpi_desc->memdevs);
                        return true;
                }

        nfit_memdev = devm_kzalloc(dev, sizeof(*nfit_memdev) + sizeof(*memdev),
                        GFP_KERNEL);
        if (!nfit_memdev)
                return false;
        INIT_LIST_HEAD(&nfit_memdev->list);
        memcpy(nfit_memdev->memdev, memdev, sizeof(*memdev));
        list_add_tail(&nfit_memdev->list, &acpi_desc->memdevs);
        dev_dbg(dev, "memdev handle: %#x spa: %d dcr: %d flags: %#x\n",
                        memdev->device_handle, memdev->range_index,
                        memdev->region_index, memdev->flags);
        return true;
}

int nfit_get_smbios_id(u32 device_handle, u16 *flags)
{
        struct acpi_nfit_memory_map *memdev;
        struct acpi_nfit_desc *acpi_desc;
        struct nfit_mem *nfit_mem;
        u16 physical_id;

        mutex_lock(&acpi_desc_lock);
        list_for_each_entry(acpi_desc, &acpi_descs, list) {
                mutex_lock(&acpi_desc->init_mutex);
                list_for_each_entry(nfit_mem, &acpi_desc->dimms, list) {
                        memdev = __to_nfit_memdev(nfit_mem);
                        if (memdev->device_handle == device_handle) {
                                *flags = memdev->flags;
                                physical_id = memdev->physical_id;
                                mutex_unlock(&acpi_desc->init_mutex);
                                mutex_unlock(&acpi_desc_lock);
                                return physical_id;
                        }
                }
                mutex_unlock(&acpi_desc->init_mutex);
        }
        mutex_unlock(&acpi_desc_lock);

        return -ENODEV;
}
EXPORT_SYMBOL_GPL(nfit_get_smbios_id);

/*
 * An implementation may provide a truncated control region if no block windows
 * are defined.
 */
static size_t sizeof_dcr(struct acpi_nfit_control_region *dcr)
{
        if (dcr->header.length < offsetof(struct acpi_nfit_control_region,
                                window_size))
                return 0;
        if (dcr->windows)
                return sizeof(*dcr);
        return offsetof(struct acpi_nfit_control_region, window_size);
}

static bool add_dcr(struct acpi_nfit_desc *acpi_desc,
                struct nfit_table_prev *prev,
                struct acpi_nfit_control_region *dcr)
{
        struct device *dev = acpi_desc->dev;
        struct nfit_dcr *nfit_dcr;

        if (!sizeof_dcr(dcr))
                return false;

        list_for_each_entry(nfit_dcr, &prev->dcrs, list)
                if (memcmp(nfit_dcr->dcr, dcr, sizeof_dcr(dcr)) == 0) {
                        list_move_tail(&nfit_dcr->list, &acpi_desc->dcrs);
                        return true;
                }

        nfit_dcr = devm_kzalloc(dev, sizeof(*nfit_dcr) + sizeof(*dcr),
                        GFP_KERNEL);
        if (!nfit_dcr)
                return false;
        INIT_LIST_HEAD(&nfit_dcr->list);
        memcpy(nfit_dcr->dcr, dcr, sizeof_dcr(dcr));
        list_add_tail(&nfit_dcr->list, &acpi_desc->dcrs);
        dev_dbg(dev, "dcr index: %d windows: %d\n",
                        dcr->region_index, dcr->windows);
        return true;
}

static bool add_bdw(struct acpi_nfit_desc *acpi_desc,
                struct nfit_table_prev *prev,
                struct acpi_nfit_data_region *bdw)
{
        struct device *dev = acpi_desc->dev;
        struct nfit_bdw *nfit_bdw;

        if (bdw->header.length != sizeof(*bdw))
                return false;
        list_for_each_entry(nfit_bdw, &prev->bdws, list)
                if (memcmp(nfit_bdw->bdw, bdw, sizeof(*bdw)) == 0) {
                        list_move_tail(&nfit_bdw->list, &acpi_desc->bdws);
                        return true;
                }

        nfit_bdw = devm_kzalloc(dev, sizeof(*nfit_bdw) + sizeof(*bdw),
                        GFP_KERNEL);
        if (!nfit_bdw)
                return false;
        INIT_LIST_HEAD(&nfit_bdw->list);
        memcpy(nfit_bdw->bdw, bdw, sizeof(*bdw));
        list_add_tail(&nfit_bdw->list, &acpi_desc->bdws);
        dev_dbg(dev, "bdw dcr: %d windows: %d\n",
                        bdw->region_index, bdw->windows);
        return true;
}

static size_t sizeof_idt(struct acpi_nfit_interleave *idt)
{
        if (idt->header.length < sizeof(*idt))
                return 0;
        return sizeof(*idt) + sizeof(u32) * (idt->line_count - 1);
}

static bool add_idt(struct acpi_nfit_desc *acpi_desc,
                struct nfit_table_prev *prev,
                struct acpi_nfit_interleave *idt)
{
        struct device *dev = acpi_desc->dev;
        struct nfit_idt *nfit_idt;

        if (!sizeof_idt(idt))
                return false;

        list_for_each_entry(nfit_idt, &prev->idts, list) {
                if (sizeof_idt(nfit_idt->idt) != sizeof_idt(idt))
                        continue;

                if (memcmp(nfit_idt->idt, idt, sizeof_idt(idt)) == 0) {
                        list_move_tail(&nfit_idt->list, &acpi_desc->idts);
                        return true;
                }
        }

        nfit_idt = devm_kzalloc(dev, sizeof(*nfit_idt) + sizeof_idt(idt),
                        GFP_KERNEL);
        if (!nfit_idt)
                return false;
        INIT_LIST_HEAD(&nfit_idt->list);
        memcpy(nfit_idt->idt, idt, sizeof_idt(idt));
        list_add_tail(&nfit_idt->list, &acpi_desc->idts);
        dev_dbg(dev, "idt index: %d num_lines: %d\n",
                        idt->interleave_index, idt->line_count);
        return true;
}

static size_t sizeof_flush(struct acpi_nfit_flush_address *flush)
{
        if (flush->header.length < sizeof(*flush))
                return 0;
        return sizeof(*flush) + sizeof(u64) * (flush->hint_count - 1);
}

static bool add_flush(struct acpi_nfit_desc *acpi_desc,
                struct nfit_table_prev *prev,
                struct acpi_nfit_flush_address *flush)
{
        struct device *dev = acpi_desc->dev;
        struct nfit_flush *nfit_flush;

        if (!sizeof_flush(flush))
                return false;

        list_for_each_entry(nfit_flush, &prev->flushes, list) {
                if (sizeof_flush(nfit_flush->flush) != sizeof_flush(flush))
                        continue;

                if (memcmp(nfit_flush->flush, flush,
                                        sizeof_flush(flush)) == 0) {
                        list_move_tail(&nfit_flush->list, &acpi_desc->flushes);
                        return true;
                }
        }

        nfit_flush = devm_kzalloc(dev, sizeof(*nfit_flush)
                        + sizeof_flush(flush), GFP_KERNEL);
        if (!nfit_flush)
                return false;
        INIT_LIST_HEAD(&nfit_flush->list);
        memcpy(nfit_flush->flush, flush, sizeof_flush(flush));
        list_add_tail(&nfit_flush->list, &acpi_desc->flushes);
        dev_dbg(dev, "nfit_flush handle: %d hint_count: %d\n",
                        flush->device_handle, flush->hint_count);
        return true;
}

static bool add_platform_cap(struct acpi_nfit_desc *acpi_desc,
                struct acpi_nfit_capabilities *pcap)
{
        struct device *dev = acpi_desc->dev;
        u32 mask;

        mask = (1 << (pcap->highest_capability + 1)) - 1;
        acpi_desc->platform_cap = pcap->capabilities & mask;
        dev_dbg(dev, "cap: %#x\n", acpi_desc->platform_cap);
        return true;
}

static void *add_table(struct acpi_nfit_desc *acpi_desc,
                struct nfit_table_prev *prev, void *table, const void *end)
{
        struct device *dev = acpi_desc->dev;
        struct acpi_nfit_header *hdr;
        void *err = ERR_PTR(-ENOMEM);

        if (table >= end)
                return NULL;

        hdr = table;
        if (!hdr->length) {
                dev_warn(dev, "found a zero length table '%d' parsing nfit\n",
                        hdr->type);
                return NULL;
        }

        switch (hdr->type) {
        case ACPI_NFIT_TYPE_SYSTEM_ADDRESS:
                if (!add_spa(acpi_desc, prev, table))
                        return err;
                break;
        case ACPI_NFIT_TYPE_MEMORY_MAP:
                if (!add_memdev(acpi_desc, prev, table))
                        return err;
                break;
        case ACPI_NFIT_TYPE_CONTROL_REGION:
                if (!add_dcr(acpi_desc, prev, table))
                        return err;
                break;
        case ACPI_NFIT_TYPE_DATA_REGION:
                if (!add_bdw(acpi_desc, prev, table))
                        return err;
                break;
        case ACPI_NFIT_TYPE_INTERLEAVE:
                if (!add_idt(acpi_desc, prev, table))
                        return err;
                break;
        case ACPI_NFIT_TYPE_FLUSH_ADDRESS:
                if (!add_flush(acpi_desc, prev, table))
                        return err;
                break;
        case ACPI_NFIT_TYPE_SMBIOS:
                dev_dbg(dev, "smbios\n");
                break;
        case ACPI_NFIT_TYPE_CAPABILITIES:
                if (!add_platform_cap(acpi_desc, table))
                        return err;
                break;
        default:
                dev_err(dev, "unknown table '%d' parsing nfit\n", hdr->type);
                break;
        }

        return table + hdr->length;
}

static void nfit_mem_find_spa_bdw(struct acpi_nfit_desc *acpi_desc,
                struct nfit_mem *nfit_mem)
{
        u32 device_handle = __to_nfit_memdev(nfit_mem)->device_handle;
        u16 dcr = nfit_mem->dcr->region_index;
        struct nfit_spa *nfit_spa;

        list_for_each_entry(nfit_spa, &acpi_desc->spas, list) {
                u16 range_index = nfit_spa->spa->range_index;
                int type = nfit_spa_type(nfit_spa->spa);
                struct nfit_memdev *nfit_memdev;

                if (type != NFIT_SPA_BDW)
                        continue;

                list_for_each_entry(nfit_memdev, &acpi_desc->memdevs, list) {
                        if (nfit_memdev->memdev->range_index != range_index)
                                continue;
                        if (nfit_memdev->memdev->device_handle != device_handle)
                                continue;
                        if (nfit_memdev->memdev->region_index != dcr)
                                continue;

                        nfit_mem->spa_bdw = nfit_spa->spa;
                        return;
                }
        }

        dev_dbg(acpi_desc->dev, "SPA-BDW not found for SPA-DCR %d\n",
                        nfit_mem->spa_dcr->range_index);
        nfit_mem->bdw = NULL;
}

static void nfit_mem_init_bdw(struct acpi_nfit_desc *acpi_desc,
                struct nfit_mem *nfit_mem, struct acpi_nfit_system_address *spa)
{
        u16 dcr = __to_nfit_memdev(nfit_mem)->region_index;
        struct nfit_memdev *nfit_memdev;
        struct nfit_bdw *nfit_bdw;
        struct nfit_idt *nfit_idt;
        u16 idt_idx, range_index;

        list_for_each_entry(nfit_bdw, &acpi_desc->bdws, list) {
                if (nfit_bdw->bdw->region_index != dcr)
                        continue;
                nfit_mem->bdw = nfit_bdw->bdw;
                break;
        }

        if (!nfit_mem->bdw)
                return;

        nfit_mem_find_spa_bdw(acpi_desc, nfit_mem);

        if (!nfit_mem->spa_bdw)
                return;

        range_index = nfit_mem->spa_bdw->range_index;
        list_for_each_entry(nfit_memdev, &acpi_desc->memdevs, list) {
                if (nfit_memdev->memdev->range_index != range_index ||
                                nfit_memdev->memdev->region_index != dcr)
                        continue;
                nfit_mem->memdev_bdw = nfit_memdev->memdev;
                idt_idx = nfit_memdev->memdev->interleave_index;
                list_for_each_entry(nfit_idt, &acpi_desc->idts, list) {
                        if (nfit_idt->idt->interleave_index != idt_idx)
                                continue;
                        nfit_mem->idt_bdw = nfit_idt->idt;
                        break;
                }
                break;
        }
}

static int __nfit_mem_init(struct acpi_nfit_desc *acpi_desc,
                struct acpi_nfit_system_address *spa)
{
        struct nfit_mem *nfit_mem, *found;
        struct nfit_memdev *nfit_memdev;
        int type = spa ? nfit_spa_type(spa) : 0;

        switch (type) {
        case NFIT_SPA_DCR:
        case NFIT_SPA_PM:
                break;
        default:
                if (spa)
                        return 0;
        }

        /*
         * This loop runs in two modes, when a dimm is mapped the loop
         * adds memdev associations to an existing dimm, or creates a
         * dimm. In the unmapped dimm case this loop sweeps for memdev
         * instances with an invalid / zero range_index and adds those
         * dimms without spa associations.
         */
        list_for_each_entry(nfit_memdev, &acpi_desc->memdevs, list) {
                struct nfit_flush *nfit_flush;
                struct nfit_dcr *nfit_dcr;
                u32 device_handle;
                u16 dcr;

                if (spa && nfit_memdev->memdev->range_index != spa->range_index)
                        continue;
                if (!spa && nfit_memdev->memdev->range_index)
                        continue;
                found = NULL;
                dcr = nfit_memdev->memdev->region_index;
                device_handle = nfit_memdev->memdev->device_handle;
                list_for_each_entry(nfit_mem, &acpi_desc->dimms, list)
                        if (__to_nfit_memdev(nfit_mem)->device_handle
                                        == device_handle) {
                                found = nfit_mem;
                                break;
                        }

                if (found)
                        nfit_mem = found;
                else {
                        nfit_mem = devm_kzalloc(acpi_desc->dev,
                                        sizeof(*nfit_mem), GFP_KERNEL);
                        if (!nfit_mem)
                                return -ENOMEM;
                        INIT_LIST_HEAD(&nfit_mem->list);
                        nfit_mem->acpi_desc = acpi_desc;
                        list_add(&nfit_mem->list, &acpi_desc->dimms);
                }

                list_for_each_entry(nfit_dcr, &acpi_desc->dcrs, list) {
                        if (nfit_dcr->dcr->region_index != dcr)
                                continue;
                        /*
                         * Record the control region for the dimm.  For
                         * the ACPI 6.1 case, where there are separate
                         * control regions for the pmem vs blk
                         * interfaces, be sure to record the extended
                         * blk details.
                         */
                        if (!nfit_mem->dcr)
                                nfit_mem->dcr = nfit_dcr->dcr;
                        else if (nfit_mem->dcr->windows == 0
                                        && nfit_dcr->dcr->windows)
                                nfit_mem->dcr = nfit_dcr->dcr;
                        break;
                }

                list_for_each_entry(nfit_flush, &acpi_desc->flushes, list) {
                        struct acpi_nfit_flush_address *flush;
                        u16 i;

                        if (nfit_flush->flush->device_handle != device_handle)
                                continue;
                        nfit_mem->nfit_flush = nfit_flush;
                        flush = nfit_flush->flush;
                        nfit_mem->flush_wpq = devm_kcalloc(acpi_desc->dev,
                                        flush->hint_count,
                                        sizeof(struct resource),
                                        GFP_KERNEL);
                        if (!nfit_mem->flush_wpq)
                                return -ENOMEM;
                        for (i = 0; i < flush->hint_count; i++) {
                                struct resource *res = &nfit_mem->flush_wpq[i];

                                res->start = flush->hint_address[i];
                                res->end = res->start + 8 - 1;
                        }
                        break;
                }

                if (dcr && !nfit_mem->dcr) {
                        dev_err(acpi_desc->dev, "SPA %d missing DCR %d\n",
                                        spa->range_index, dcr);
                        return -ENODEV;
                }

                if (type == NFIT_SPA_DCR) {
                        struct nfit_idt *nfit_idt;
                        u16 idt_idx;

                        /* multiple dimms may share a SPA when interleaved */
                        nfit_mem->spa_dcr = spa;
                        nfit_mem->memdev_dcr = nfit_memdev->memdev;
                        idt_idx = nfit_memdev->memdev->interleave_index;
                        list_for_each_entry(nfit_idt, &acpi_desc->idts, list) {
                                if (nfit_idt->idt->interleave_index != idt_idx)
                                        continue;
                                nfit_mem->idt_dcr = nfit_idt->idt;
                                break;
                        }
                        nfit_mem_init_bdw(acpi_desc, nfit_mem, spa);
                } else if (type == NFIT_SPA_PM) {
                        /*
                         * A single dimm may belong to multiple SPA-PM
                         * ranges, record at least one in addition to
                         * any SPA-DCR range.
                         */
                        nfit_mem->memdev_pmem = nfit_memdev->memdev;
                } else
                        nfit_mem->memdev_dcr = nfit_memdev->memdev;
        }

        return 0;
}

static int nfit_mem_cmp(void *priv, struct list_head *_a, struct list_head *_b)
{
        struct nfit_mem *a = container_of(_a, typeof(*a), list);
        struct nfit_mem *b = container_of(_b, typeof(*b), list);
        u32 handleA, handleB;

        handleA = __to_nfit_memdev(a)->device_handle;
        handleB = __to_nfit_memdev(b)->device_handle;
        if (handleA < handleB)
                return -1;
        else if (handleA > handleB)
                return 1;
        return 0;
}

static int nfit_mem_init(struct acpi_nfit_desc *acpi_desc)
{
        struct nfit_spa *nfit_spa;
        int rc;


        /*
         * For each SPA-DCR or SPA-PMEM address range find its
         * corresponding MEMDEV(s).  From each MEMDEV find the
         * corresponding DCR.  Then, if we're operating on a SPA-DCR,
         * try to find a SPA-BDW and a corresponding BDW that references
         * the DCR.  Throw it all into an nfit_mem object.  Note, that
         * BDWs are optional.
         */
        list_for_each_entry(nfit_spa, &acpi_desc->spas, list) {
                rc = __nfit_mem_init(acpi_desc, nfit_spa->spa);
                if (rc)
                        return rc;
        }

        /*
         * If a DIMM has failed to be mapped into SPA there will be no
         * SPA entries above. Find and register all the unmapped DIMMs
         * for reporting and recovery purposes.
         */
        rc = __nfit_mem_init(acpi_desc, NULL);
        if (rc)
                return rc;

        list_sort(NULL, &acpi_desc->dimms, nfit_mem_cmp);

        return 0;
}

static ssize_t bus_dsm_mask_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
        struct nvdimm_bus_descriptor *nd_desc = to_nd_desc(nvdimm_bus);

        return sprintf(buf, "%#lx\n", nd_desc->bus_dsm_mask);
}
static struct device_attribute dev_attr_bus_dsm_mask =
                __ATTR(dsm_mask, 0444, bus_dsm_mask_show, NULL);

static ssize_t revision_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
        struct nvdimm_bus_descriptor *nd_desc = to_nd_desc(nvdimm_bus);
        struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);

        return sprintf(buf, "%d\n", acpi_desc->acpi_header.revision);
}
static DEVICE_ATTR_RO(revision);

static ssize_t hw_error_scrub_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
        struct nvdimm_bus_descriptor *nd_desc = to_nd_desc(nvdimm_bus);
        struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);

        return sprintf(buf, "%d\n", acpi_desc->scrub_mode);
}

/*
 * The 'hw_error_scrub' attribute can have the following values written to it:
 * '0': Switch to the default mode where an exception will only insert
 *      the address of the memory error into the poison and badblocks lists.
 * '1': Enable a full scrub to happen if an exception for a memory error is
 *      received.
 */
static ssize_t hw_error_scrub_store(struct device *dev,
                struct device_attribute *attr, const char *buf, size_t size)
{
        struct nvdimm_bus_descriptor *nd_desc;
        ssize_t rc;
        long val;

        rc = kstrtol(buf, 0, &val);
        if (rc)
                return rc;

        device_lock(dev);
        nd_desc = dev_get_drvdata(dev);
        if (nd_desc) {
                struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);

                switch (val) {
                case HW_ERROR_SCRUB_ON:
                        acpi_desc->scrub_mode = HW_ERROR_SCRUB_ON;
                        break;
                case HW_ERROR_SCRUB_OFF:
                        acpi_desc->scrub_mode = HW_ERROR_SCRUB_OFF;
                        break;
                default:
                        rc = -EINVAL;
                        break;
                }
        }
        device_unlock(dev);
        if (rc)
                return rc;
        return size;
}
static DEVICE_ATTR_RW(hw_error_scrub);

/*
 * This shows the number of full Address Range Scrubs that have been
 * completed since driver load time. Userspace can wait on this using
 * select/poll etc. A '+' at the end indicates an ARS is in progress
 */
static ssize_t scrub_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct nvdimm_bus_descriptor *nd_desc;
        struct acpi_nfit_desc *acpi_desc;
        ssize_t rc = -ENXIO;
        bool busy;

        device_lock(dev);
        nd_desc = dev_get_drvdata(dev);
        if (!nd_desc) {
                device_unlock(dev);
                return rc;
        }
        acpi_desc = to_acpi_desc(nd_desc);

        mutex_lock(&acpi_desc->init_mutex);
        busy = test_bit(ARS_BUSY, &acpi_desc->scrub_flags)
                && !test_bit(ARS_CANCEL, &acpi_desc->scrub_flags);
        rc = sprintf(buf, "%d%s", acpi_desc->scrub_count, busy ? "+\n" : "\n");
        /* Allow an admin to poll the busy state at a higher rate */
        if (busy && capable(CAP_SYS_RAWIO) && !test_and_set_bit(ARS_POLL,
                                &acpi_desc->scrub_flags)) {
                acpi_desc->scrub_tmo = 1;
                mod_delayed_work(nfit_wq, &acpi_desc->dwork, HZ);
        }

        mutex_unlock(&acpi_desc->init_mutex);
        device_unlock(dev);
        return rc;
}

static ssize_t scrub_store(struct device *dev,
                struct device_attribute *attr, const char *buf, size_t size)
{
        struct nvdimm_bus_descriptor *nd_desc;
        ssize_t rc;
        long val;

        rc = kstrtol(buf, 0, &val);
        if (rc)
                return rc;
        if (val != 1)
                return -EINVAL;

        device_lock(dev);
        nd_desc = dev_get_drvdata(dev);
        if (nd_desc) {
                struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);

                rc = acpi_nfit_ars_rescan(acpi_desc, ARS_REQ_LONG);
        }
        device_unlock(dev);
        if (rc)
                return rc;
        return size;
}
static DEVICE_ATTR_RW(scrub);

static bool ars_supported(struct nvdimm_bus *nvdimm_bus)
{
        struct nvdimm_bus_descriptor *nd_desc = to_nd_desc(nvdimm_bus);
        const unsigned long mask = 1 << ND_CMD_ARS_CAP | 1 << ND_CMD_ARS_START
                | 1 << ND_CMD_ARS_STATUS;

        return (nd_desc->cmd_mask & mask) == mask;
}

static umode_t nfit_visible(struct kobject *kobj, struct attribute *a, int n)
{
        struct device *dev = container_of(kobj, struct device, kobj);
        struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);

        if (a == &dev_attr_scrub.attr && !ars_supported(nvdimm_bus))
                return 0;
        return a->mode;
}

static struct attribute *acpi_nfit_attributes[] = {
        &dev_attr_revision.attr,
        &dev_attr_scrub.attr,
        &dev_attr_hw_error_scrub.attr,
        &dev_attr_bus_dsm_mask.attr,
        NULL,
};

static const struct attribute_group acpi_nfit_attribute_group = {
        .name = "nfit",
        .attrs = acpi_nfit_attributes,
        .is_visible = nfit_visible,
};

static const struct attribute_group *acpi_nfit_attribute_groups[] = {
        &nvdimm_bus_attribute_group,
        &acpi_nfit_attribute_group,
        NULL,
};

static struct acpi_nfit_memory_map *to_nfit_memdev(struct device *dev)
{
        struct nvdimm *nvdimm = to_nvdimm(dev);
        struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);

        return __to_nfit_memdev(nfit_mem);
}

static struct acpi_nfit_control_region *to_nfit_dcr(struct device *dev)
{
        struct nvdimm *nvdimm = to_nvdimm(dev);
        struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);

        return nfit_mem->dcr;
}

static ssize_t handle_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct acpi_nfit_memory_map *memdev = to_nfit_memdev(dev);

        return sprintf(buf, "%#x\n", memdev->device_handle);
}
static DEVICE_ATTR_RO(handle);

static ssize_t phys_id_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct acpi_nfit_memory_map *memdev = to_nfit_memdev(dev);

        return sprintf(buf, "%#x\n", memdev->physical_id);
}
static DEVICE_ATTR_RO(phys_id);

static ssize_t vendor_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct acpi_nfit_control_region *dcr = to_nfit_dcr(dev);

        return sprintf(buf, "0x%04x\n", be16_to_cpu(dcr->vendor_id));
}
static DEVICE_ATTR_RO(vendor);

static ssize_t rev_id_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct acpi_nfit_control_region *dcr = to_nfit_dcr(dev);

        return sprintf(buf, "0x%04x\n", be16_to_cpu(dcr->revision_id));
}
static DEVICE_ATTR_RO(rev_id);

static ssize_t device_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct acpi_nfit_control_region *dcr = to_nfit_dcr(dev);

        return sprintf(buf, "0x%04x\n", be16_to_cpu(dcr->device_id));
}
static DEVICE_ATTR_RO(device);

static ssize_t subsystem_vendor_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct acpi_nfit_control_region *dcr = to_nfit_dcr(dev);

        return sprintf(buf, "0x%04x\n", be16_to_cpu(dcr->subsystem_vendor_id));
}
static DEVICE_ATTR_RO(subsystem_vendor);

static ssize_t subsystem_rev_id_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct acpi_nfit_control_region *dcr = to_nfit_dcr(dev);

        return sprintf(buf, "0x%04x\n",
                        be16_to_cpu(dcr->subsystem_revision_id));
}
static DEVICE_ATTR_RO(subsystem_rev_id);

static ssize_t subsystem_device_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct acpi_nfit_control_region *dcr = to_nfit_dcr(dev);

        return sprintf(buf, "0x%04x\n", be16_to_cpu(dcr->subsystem_device_id));
}
static DEVICE_ATTR_RO(subsystem_device);

static int num_nvdimm_formats(struct nvdimm *nvdimm)
{
        struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
        int formats = 0;

        if (nfit_mem->memdev_pmem)
                formats++;
        if (nfit_mem->memdev_bdw)
                formats++;
        return formats;
}

static ssize_t format_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct acpi_nfit_control_region *dcr = to_nfit_dcr(dev);

        return sprintf(buf, "0x%04x\n", le16_to_cpu(dcr->code));
}
static DEVICE_ATTR_RO(format);

static ssize_t format1_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        u32 handle;
        ssize_t rc = -ENXIO;
        struct nfit_mem *nfit_mem;
        struct nfit_memdev *nfit_memdev;
        struct acpi_nfit_desc *acpi_desc;
        struct nvdimm *nvdimm = to_nvdimm(dev);
        struct acpi_nfit_control_region *dcr = to_nfit_dcr(dev);

        nfit_mem = nvdimm_provider_data(nvdimm);
        acpi_desc = nfit_mem->acpi_desc;
        handle = to_nfit_memdev(dev)->device_handle;

        /* assumes DIMMs have at most 2 published interface codes */
        mutex_lock(&acpi_desc->init_mutex);
        list_for_each_entry(nfit_memdev, &acpi_desc->memdevs, list) {
                struct acpi_nfit_memory_map *memdev = nfit_memdev->memdev;
                struct nfit_dcr *nfit_dcr;

                if (memdev->device_handle != handle)
                        continue;

                list_for_each_entry(nfit_dcr, &acpi_desc->dcrs, list) {
                        if (nfit_dcr->dcr->region_index != memdev->region_index)
                                continue;
                        if (nfit_dcr->dcr->code == dcr->code)
                                continue;
                        rc = sprintf(buf, "0x%04x\n",
                                        le16_to_cpu(nfit_dcr->dcr->code));
                        break;
                }
                if (rc != ENXIO)
                        break;
        }
        mutex_unlock(&acpi_desc->init_mutex);
        return rc;
}
static DEVICE_ATTR_RO(format1);

static ssize_t formats_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct nvdimm *nvdimm = to_nvdimm(dev);

        return sprintf(buf, "%d\n", num_nvdimm_formats(nvdimm));
}
static DEVICE_ATTR_RO(formats);

static ssize_t serial_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct acpi_nfit_control_region *dcr = to_nfit_dcr(dev);

        return sprintf(buf, "0x%08x\n", be32_to_cpu(dcr->serial_number));
}
static DEVICE_ATTR_RO(serial);

static ssize_t family_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct nvdimm *nvdimm = to_nvdimm(dev);
        struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);

        if (nfit_mem->family < 0)
                return -ENXIO;
        return sprintf(buf, "%d\n", nfit_mem->family);
}
static DEVICE_ATTR_RO(family);

static ssize_t dsm_mask_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct nvdimm *nvdimm = to_nvdimm(dev);
        struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);

        if (nfit_mem->family < 0)
                return -ENXIO;
        return sprintf(buf, "%#lx\n", nfit_mem->dsm_mask);
}
static DEVICE_ATTR_RO(dsm_mask);

static ssize_t flags_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct nvdimm *nvdimm = to_nvdimm(dev);
        struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
        u16 flags = __to_nfit_memdev(nfit_mem)->flags;

        if (test_bit(NFIT_MEM_DIRTY, &nfit_mem->flags))
                flags |= ACPI_NFIT_MEM_FLUSH_FAILED;

        return sprintf(buf, "%s%s%s%s%s%s%s\n",
                flags & ACPI_NFIT_MEM_SAVE_FAILED ? "save_fail " : "",
                flags & ACPI_NFIT_MEM_RESTORE_FAILED ? "restore_fail " : "",
                flags & ACPI_NFIT_MEM_FLUSH_FAILED ? "flush_fail " : "",
                flags & ACPI_NFIT_MEM_NOT_ARMED ? "not_armed " : "",
                flags & ACPI_NFIT_MEM_HEALTH_OBSERVED ? "smart_event " : "",
                flags & ACPI_NFIT_MEM_MAP_FAILED ? "map_fail " : "",
                flags & ACPI_NFIT_MEM_HEALTH_ENABLED ? "smart_notify " : "");
}
static DEVICE_ATTR_RO(flags);

static ssize_t id_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct nvdimm *nvdimm = to_nvdimm(dev);
        struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);

        return sprintf(buf, "%s\n", nfit_mem->id);
}
static DEVICE_ATTR_RO(id);

static ssize_t dirty_shutdown_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct nvdimm *nvdimm = to_nvdimm(dev);
        struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);

        return sprintf(buf, "%d\n", nfit_mem->dirty_shutdown);
}
static DEVICE_ATTR_RO(dirty_shutdown);

static struct attribute *acpi_nfit_dimm_attributes[] = {
        &dev_attr_handle.attr,
        &dev_attr_phys_id.attr,
        &dev_attr_vendor.attr,
        &dev_attr_device.attr,
        &dev_attr_rev_id.attr,
        &dev_attr_subsystem_vendor.attr,
        &dev_attr_subsystem_device.attr,
        &dev_attr_subsystem_rev_id.attr,
        &dev_attr_format.attr,
        &dev_attr_formats.attr,
        &dev_attr_format1.attr,
        &dev_attr_serial.attr,
        &dev_attr_flags.attr,
        &dev_attr_id.attr,
        &dev_attr_family.attr,
        &dev_attr_dsm_mask.attr,
        &dev_attr_dirty_shutdown.attr,
        NULL,
};

static umode_t acpi_nfit_dimm_attr_visible(struct kobject *kobj,
                struct attribute *a, int n)
{
        struct device *dev = container_of(kobj, struct device, kobj);
        struct nvdimm *nvdimm = to_nvdimm(dev);
        struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);

        if (!to_nfit_dcr(dev)) {
                /* Without a dcr only the memdev attributes can be surfaced */
                if (a == &dev_attr_handle.attr || a == &dev_attr_phys_id.attr
                                || a == &dev_attr_flags.attr
                                || a == &dev_attr_family.attr
                                || a == &dev_attr_dsm_mask.attr)
                        return a->mode;
                return 0;
        }

        if (a == &dev_attr_format1.attr && num_nvdimm_formats(nvdimm) <= 1)
                return 0;

        if (!test_bit(NFIT_MEM_DIRTY_COUNT, &nfit_mem->flags)
                        && a == &dev_attr_dirty_shutdown.attr)
                return 0;

        return a->mode;
}

static const struct attribute_group acpi_nfit_dimm_attribute_group = {
        .name = "nfit",
        .attrs = acpi_nfit_dimm_attributes,
        .is_visible = acpi_nfit_dimm_attr_visible,
};

static const struct attribute_group *acpi_nfit_dimm_attribute_groups[] = {
        &nvdimm_attribute_group,
        &nd_device_attribute_group,
        &acpi_nfit_dimm_attribute_group,
        NULL,
};

static struct nvdimm *acpi_nfit_dimm_by_handle(struct acpi_nfit_desc *acpi_desc,
                u32 device_handle)
{
        struct nfit_mem *nfit_mem;

        list_for_each_entry(nfit_mem, &acpi_desc->dimms, list)
                if (__to_nfit_memdev(nfit_mem)->device_handle == device_handle)
                        return nfit_mem->nvdimm;

        return NULL;
}

void __acpi_nvdimm_notify(struct device *dev, u32 event)
{
        struct nfit_mem *nfit_mem;
        struct acpi_nfit_desc *acpi_desc;

        dev_dbg(dev->parent, "%s: event: %d\n", dev_name(dev),
                        event);

        if (event != NFIT_NOTIFY_DIMM_HEALTH) {
                dev_dbg(dev->parent, "%s: unknown event: %d\n", dev_name(dev),
                                event);
                return;
        }

        acpi_desc = dev_get_drvdata(dev->parent);
        if (!acpi_desc)
                return;

        /*
         * If we successfully retrieved acpi_desc, then we know nfit_mem data
         * is still valid.
         */
        nfit_mem = dev_get_drvdata(dev);
        if (nfit_mem && nfit_mem->flags_attr)
                sysfs_notify_dirent(nfit_mem->flags_attr);
}
EXPORT_SYMBOL_GPL(__acpi_nvdimm_notify);

static void acpi_nvdimm_notify(acpi_handle handle, u32 event, void *data)
{
        struct acpi_device *adev = data;
        struct device *dev = &adev->dev;

        device_lock(dev->parent);
        __acpi_nvdimm_notify(dev, event);
        device_unlock(dev->parent);
}

static bool acpi_nvdimm_has_method(struct acpi_device *adev, char *method)
{
        acpi_handle handle;
        acpi_status status;

        status = acpi_get_handle(adev->handle, method, &handle);

        if (ACPI_SUCCESS(status))
                return true;
        return false;
}

__weak void nfit_intel_shutdown_status(struct nfit_mem *nfit_mem)
{
        struct device *dev = &nfit_mem->adev->dev;
        struct nd_intel_smart smart = { 0 };
        union acpi_object in_buf = {
                .buffer.type = ACPI_TYPE_BUFFER,
                .buffer.length = 0,
        };
        union acpi_object in_obj = {
                .package.type = ACPI_TYPE_PACKAGE,
                .package.count = 1,
                .package.elements = &in_buf,
        };
        const u8 func = ND_INTEL_SMART;
        const guid_t *guid = to_nfit_uuid(nfit_mem->family);
        u8 revid = nfit_dsm_revid(nfit_mem->family, func);
        struct acpi_device *adev = nfit_mem->adev;
        acpi_handle handle = adev->handle;
        union acpi_object *out_obj;

        if ((nfit_mem->dsm_mask & (1 << func)) == 0)
                return;

        out_obj = acpi_evaluate_dsm(handle, guid, revid, func, &in_obj);
        if (!out_obj || out_obj->type != ACPI_TYPE_BUFFER
                        || out_obj->buffer.length < sizeof(smart)) {
                dev_dbg(dev->parent, "%s: failed to retrieve initial health\n",
                                dev_name(dev));
                ACPI_FREE(out_obj);
                return;
        }
        memcpy(&smart, out_obj->buffer.pointer, sizeof(smart));
        ACPI_FREE(out_obj);

        if (smart.flags & ND_INTEL_SMART_SHUTDOWN_VALID) {
                if (smart.shutdown_state)
                        set_bit(NFIT_MEM_DIRTY, &nfit_mem->flags);
        }

        if (smart.flags & ND_INTEL_SMART_SHUTDOWN_COUNT_VALID) {
                set_bit(NFIT_MEM_DIRTY_COUNT, &nfit_mem->flags);
                nfit_mem->dirty_shutdown = smart.shutdown_count;
        }
}

static void populate_shutdown_status(struct nfit_mem *nfit_mem)
{
        /*
         * For DIMMs that provide a dynamic facility to retrieve a
         * dirty-shutdown status and/or a dirty-shutdown count, cache
         * these values in nfit_mem.
         */
        if (nfit_mem->family == NVDIMM_FAMILY_INTEL)
                nfit_intel_shutdown_status(nfit_mem);
}

static int acpi_nfit_add_dimm(struct acpi_nfit_desc *acpi_desc,
                struct nfit_mem *nfit_mem, u32 device_handle)
{
        struct acpi_device *adev, *adev_dimm;
        struct device *dev = acpi_desc->dev;
        unsigned long dsm_mask, label_mask;
        const guid_t *guid;
        int i;
        int family = -1;
        struct acpi_nfit_control_region *dcr = nfit_mem->dcr;

        /* nfit test assumes 1:1 relationship between commands and dsms */
        nfit_mem->dsm_mask = acpi_desc->dimm_cmd_force_en;
        nfit_mem->family = NVDIMM_FAMILY_INTEL;

        if (dcr->valid_fields & ACPI_NFIT_CONTROL_MFG_INFO_VALID)
                sprintf(nfit_mem->id, "%04x-%02x-%04x-%08x",
                                be16_to_cpu(dcr->vendor_id),
                                dcr->manufacturing_location,
                                be16_to_cpu(dcr->manufacturing_date),
                                be32_to_cpu(dcr->serial_number));
        else
                sprintf(nfit_mem->id, "%04x-%08x",
                                be16_to_cpu(dcr->vendor_id),
                                be32_to_cpu(dcr->serial_number));

        adev = to_acpi_dev(acpi_desc);
        if (!adev) {
                /* unit test case */
                populate_shutdown_status(nfit_mem);
                return 0;
        }

        adev_dimm = acpi_find_child_device(adev, device_handle, false);
        nfit_mem->adev = adev_dimm;
        if (!adev_dimm) {
                dev_err(dev, "no ACPI.NFIT device with _ADR %#x, disabling...\n",
                                device_handle);
                return force_enable_dimms ? 0 : -ENODEV;
        }

        if (ACPI_FAILURE(acpi_install_notify_handler(adev_dimm->handle,
                ACPI_DEVICE_NOTIFY, acpi_nvdimm_notify, adev_dimm))) {
                dev_err(dev, "%s: notification registration failed\n",
                                dev_name(&adev_dimm->dev));
                return -ENXIO;
        }
        /*
         * Record nfit_mem for the notification path to track back to
         * the nfit sysfs attributes for this dimm device object.
         */
        dev_set_drvdata(&adev_dimm->dev, nfit_mem);

        /*
         * There are 4 "legacy" NVDIMM command sets
         * (NVDIMM_FAMILY_{INTEL,MSFT,HPE1,HPE2}) that were created before
         * an EFI working group was established to constrain this
         * proliferation. The nfit driver probes for the supported command
         * set by GUID. Note, if you're a platform developer looking to add
         * a new command set to this probe, consider using an existing set,
         * or otherwise seek approval to publish the command set at
         * http://www.uefi.org/RFIC_LIST.
         *
         * Note, that checking for function0 (bit0) tells us if any commands
         * are reachable through this GUID.
         */
        for (i = 0; i <= NVDIMM_FAMILY_MAX; i++)
                if (acpi_check_dsm(adev_dimm->handle, to_nfit_uuid(i), 1, 1))
                        if (family < 0 || i == default_dsm_family)
                                family = i;

        /* limit the supported commands to those that are publicly documented */
        nfit_mem->family = family;
        if (override_dsm_mask && !disable_vendor_specific)
                dsm_mask = override_dsm_mask;
        else if (nfit_mem->family == NVDIMM_FAMILY_INTEL) {
                dsm_mask = NVDIMM_INTEL_CMDMASK;
                if (disable_vendor_specific)
                        dsm_mask &= ~(1 << ND_CMD_VENDOR);
        } else if (nfit_mem->family == NVDIMM_FAMILY_HPE1) {
                dsm_mask = 0x1c3c76;
        } else if (nfit_mem->family == NVDIMM_FAMILY_HPE2) {
                dsm_mask = 0x1fe;
                if (disable_vendor_specific)
                        dsm_mask &= ~(1 << 8);
        } else if (nfit_mem->family == NVDIMM_FAMILY_MSFT) {
                dsm_mask = 0xffffffff;
        } else if (nfit_mem->family == NVDIMM_FAMILY_HYPERV) {
                dsm_mask = 0x1f;
        } else {
                dev_dbg(dev, "unknown dimm command family\n");
                nfit_mem->family = -1;
                /* DSMs are optional, continue loading the driver... */
                return 0;
        }

        /*
         * Function 0 is the command interrogation function, don't
         * export it to potential userspace use, and enable it to be
         * used as an error value in acpi_nfit_ctl().
         */
        dsm_mask &= ~1UL;

        guid = to_nfit_uuid(nfit_mem->family);
        for_each_set_bit(i, &dsm_mask, BITS_PER_LONG)
                if (acpi_check_dsm(adev_dimm->handle, guid,
                                        nfit_dsm_revid(nfit_mem->family, i),
                                        1ULL << i))
                        set_bit(i, &nfit_mem->dsm_mask);

        /*
         * Prefer the NVDIMM_FAMILY_INTEL label read commands if present
         * due to their better semantics handling locked capacity.
         */
        label_mask = 1 << ND_CMD_GET_CONFIG_SIZE | 1 << ND_CMD_GET_CONFIG_DATA
                | 1 << ND_CMD_SET_CONFIG_DATA;
        if (family == NVDIMM_FAMILY_INTEL
                        && (dsm_mask & label_mask) == label_mask)
                /* skip _LS{I,R,W} enabling */;
        else {
                if (acpi_nvdimm_has_method(adev_dimm, "_LSI")
                                && acpi_nvdimm_has_method(adev_dimm, "_LSR")) {
                        dev_dbg(dev, "%s: has _LSR\n", dev_name(&adev_dimm->dev));
                        set_bit(NFIT_MEM_LSR, &nfit_mem->flags);
                }

                if (test_bit(NFIT_MEM_LSR, &nfit_mem->flags)
                                && acpi_nvdimm_has_method(adev_dimm, "_LSW")) {
                        dev_dbg(dev, "%s: has _LSW\n", dev_name(&adev_dimm->dev));
                        set_bit(NFIT_MEM_LSW, &nfit_mem->flags);
                }

                /*
                 * Quirk read-only label configurations to preserve
                 * access to label-less namespaces by default.
                 */
                if (!test_bit(NFIT_MEM_LSW, &nfit_mem->flags)
                                && !force_labels) {
                        dev_dbg(dev, "%s: No _LSW, disable labels\n",
                                        dev_name(&adev_dimm->dev));
                        clear_bit(NFIT_MEM_LSR, &nfit_mem->flags);
                } else
                        dev_dbg(dev, "%s: Force enable labels\n",
                                        dev_name(&adev_dimm->dev));
        }

        populate_shutdown_status(nfit_mem);

        return 0;
}

static void shutdown_dimm_notify(void *data)
{
        struct acpi_nfit_desc *acpi_desc = data;
        struct nfit_mem *nfit_mem;

        mutex_lock(&acpi_desc->init_mutex);
        /*
         * Clear out the nfit_mem->flags_attr and shut down dimm event
         * notifications.
         */
        list_for_each_entry(nfit_mem, &acpi_desc->dimms, list) {
                struct acpi_device *adev_dimm = nfit_mem->adev;

                if (nfit_mem->flags_attr) {
                        sysfs_put(nfit_mem->flags_attr);
                        nfit_mem->flags_attr = NULL;
                }

                if (adev_dimm) {
                        acpi_remove_notify_handler(adev_dimm->handle,
                                        ACPI_DEVICE_NOTIFY, acpi_nvdimm_notify);
                        dev_set_drvdata(&adev_dimm->dev, NULL);
                }
        }
        mutex_unlock(&acpi_desc->init_mutex);
}

static const struct nvdimm_security_ops *acpi_nfit_get_security_ops(int family)
{
        switch (family) {
        case NVDIMM_FAMILY_INTEL:
                return intel_security_ops;
        default:
                return NULL;
        }
}

static int acpi_nfit_register_dimms(struct acpi_nfit_desc *acpi_desc)
{
        struct nfit_mem *nfit_mem;
        int dimm_count = 0, rc;
        struct nvdimm *nvdimm;

        list_for_each_entry(nfit_mem, &acpi_desc->dimms, list) {
                struct acpi_nfit_flush_address *flush;
                unsigned long flags = 0, cmd_mask;
                struct nfit_memdev *nfit_memdev;
                u32 device_handle;
                u16 mem_flags;

                device_handle = __to_nfit_memdev(nfit_mem)->device_handle;
                nvdimm = acpi_nfit_dimm_by_handle(acpi_desc, device_handle);
                if (nvdimm) {
                        dimm_count++;
                        continue;
                }

                if (nfit_mem->bdw && nfit_mem->memdev_pmem)
                        set_bit(NDD_ALIASING, &flags);

                /* collate flags across all memdevs for this dimm */
                list_for_each_entry(nfit_memdev, &acpi_desc->memdevs, list) {
                        struct acpi_nfit_memory_map *dimm_memdev;

                        dimm_memdev = __to_nfit_memdev(nfit_mem);
                        if (dimm_memdev->device_handle
                                        != nfit_memdev->memdev->device_handle)
                                continue;
                        dimm_memdev->flags |= nfit_memdev->memdev->flags;
                }

                mem_flags = __to_nfit_memdev(nfit_mem)->flags;
                if (mem_flags & ACPI_NFIT_MEM_NOT_ARMED)
                        set_bit(NDD_UNARMED, &flags);

                rc = acpi_nfit_add_dimm(acpi_desc, nfit_mem, device_handle);
                if (rc)
                        continue;

                /*
                 * TODO: provide translation for non-NVDIMM_FAMILY_INTEL
                 * devices (i.e. from nd_cmd to acpi_dsm) to standardize the
                 * userspace interface.
                 */
                cmd_mask = 1UL << ND_CMD_CALL;
                if (nfit_mem->family == NVDIMM_FAMILY_INTEL) {
                        /*
                         * These commands have a 1:1 correspondence
                         * between DSM payload and libnvdimm ioctl
                         * payload format.
                         */
                        cmd_mask |= nfit_mem->dsm_mask & NVDIMM_STANDARD_CMDMASK;
                }

                /* Quirk to ignore LOCAL for labels on HYPERV DIMMs */
                if (nfit_mem->family == NVDIMM_FAMILY_HYPERV)
                        set_bit(NDD_NOBLK, &flags);

                if (test_bit(NFIT_MEM_LSR, &nfit_mem->flags)) {
                        set_bit(ND_CMD_GET_CONFIG_SIZE, &cmd_mask);
                        set_bit(ND_CMD_GET_CONFIG_DATA, &cmd_mask);
                }
                if (test_bit(NFIT_MEM_LSW, &nfit_mem->flags))
                        set_bit(ND_CMD_SET_CONFIG_DATA, &cmd_mask);

                flush = nfit_mem->nfit_flush ? nfit_mem->nfit_flush->flush
                        : NULL;
                nvdimm = __nvdimm_create(acpi_desc->nvdimm_bus, nfit_mem,
                                acpi_nfit_dimm_attribute_groups,
                                flags, cmd_mask, flush ? flush->hint_count : 0,
                                nfit_mem->flush_wpq, &nfit_mem->id[0],
                                acpi_nfit_get_security_ops(nfit_mem->family));
                if (!nvdimm)
                        return -ENOMEM;

                nfit_mem->nvdimm = nvdimm;
                dimm_count++;

                if ((mem_flags & ACPI_NFIT_MEM_FAILED_MASK) == 0)
                        continue;

                dev_err(acpi_desc->dev, "Error found in NVDIMM %s flags:%s%s%s%s%s\n",
                                nvdimm_name(nvdimm),
                  mem_flags & ACPI_NFIT_MEM_SAVE_FAILED ? " save_fail" : "",
                  mem_flags & ACPI_NFIT_MEM_RESTORE_FAILED ? " restore_fail":"",
                  mem_flags & ACPI_NFIT_MEM_FLUSH_FAILED ? " flush_fail" : "",
                  mem_flags & ACPI_NFIT_MEM_NOT_ARMED ? " not_armed" : "",
                  mem_flags & ACPI_NFIT_MEM_MAP_FAILED ? " map_fail" : "");

        }

        rc = nvdimm_bus_check_dimm_count(acpi_desc->nvdimm_bus, dimm_count);
        if (rc)
                return rc;

        /*
         * Now that dimms are successfully registered, and async registration
         * is flushed, attempt to enable event notification.
         */
        list_for_each_entry(nfit_mem, &acpi_desc->dimms, list) {
                struct kernfs_node *nfit_kernfs;

                nvdimm = nfit_mem->nvdimm;
                if (!nvdimm)
                        continue;

                nfit_kernfs = sysfs_get_dirent(nvdimm_kobj(nvdimm)->sd, "nfit");
                if (nfit_kernfs)
                        nfit_mem->flags_attr = sysfs_get_dirent(nfit_kernfs,
                                        "flags");
                sysfs_put(nfit_kernfs);
                if (!nfit_mem->flags_attr)
                        dev_warn(acpi_desc->dev, "%s: notifications disabled\n",
                                        nvdimm_name(nvdimm));
        }

        return devm_add_action_or_reset(acpi_desc->dev, shutdown_dimm_notify,
                        acpi_desc);
}

/*
 * These constants are private because there are no kernel consumers of
 * these commands.
 */
enum nfit_aux_cmds {
        NFIT_CMD_TRANSLATE_SPA = 5,
        NFIT_CMD_ARS_INJECT_SET = 7,
        NFIT_CMD_ARS_INJECT_CLEAR = 8,
        NFIT_CMD_ARS_INJECT_GET = 9,
};

static void acpi_nfit_init_dsms(struct acpi_nfit_desc *acpi_desc)
{
        struct nvdimm_bus_descriptor *nd_desc = &acpi_desc->nd_desc;
        const guid_t *guid = to_nfit_uuid(NFIT_DEV_BUS);
        struct acpi_device *adev;
        unsigned long dsm_mask;
        int i;

        nd_desc->cmd_mask = acpi_desc->bus_cmd_force_en;
        nd_desc->bus_dsm_mask = acpi_desc->bus_nfit_cmd_force_en;
        adev = to_acpi_dev(acpi_desc);
        if (!adev)
                return;

        for (i = ND_CMD_ARS_CAP; i <= ND_CMD_CLEAR_ERROR; i++)
                if (acpi_check_dsm(adev->handle, guid, 1, 1ULL << i))
                        set_bit(i, &nd_desc->cmd_mask);
        set_bit(ND_CMD_CALL, &nd_desc->cmd_mask);

        dsm_mask =
                (1 << ND_CMD_ARS_CAP) |
                (1 << ND_CMD_ARS_START) |
                (1 << ND_CMD_ARS_STATUS) |
                (1 << ND_CMD_CLEAR_ERROR) |
                (1 << NFIT_CMD_TRANSLATE_SPA) |
                (1 << NFIT_CMD_ARS_INJECT_SET) |
                (1 << NFIT_CMD_ARS_INJECT_CLEAR) |
                (1 << NFIT_CMD_ARS_INJECT_GET);
        for_each_set_bit(i, &dsm_mask, BITS_PER_LONG)
                if (acpi_check_dsm(adev->handle, guid, 1, 1ULL << i))
                        set_bit(i, &nd_desc->bus_dsm_mask);
}

static ssize_t range_index_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct nd_region *nd_region = to_nd_region(dev);
        struct nfit_spa *nfit_spa = nd_region_provider_data(nd_region);

        return sprintf(buf, "%d\n", nfit_spa->spa->range_index);
}
static DEVICE_ATTR_RO(range_index);

static struct attribute *acpi_nfit_region_attributes[] = {
        &dev_attr_range_index.attr,
        NULL,
};

static const struct attribute_group acpi_nfit_region_attribute_group = {
        .name = "nfit",
        .attrs = acpi_nfit_region_attributes,
};

static const struct attribute_group *acpi_nfit_region_attribute_groups[] = {
        &nd_region_attribute_group,
        &nd_mapping_attribute_group,
        &nd_device_attribute_group,
        &nd_numa_attribute_group,
        &acpi_nfit_region_attribute_group,
        NULL,
};

/* enough info to uniquely specify an interleave set */
struct nfit_set_info {
        struct nfit_set_info_map {
                u64 region_offset;
                u32 serial_number;
                u32 pad;
        } mapping[0];
};

struct nfit_set_info2 {
        struct nfit_set_info_map2 {
                u64 region_offset;
                u32 serial_number;
                u16 vendor_id;
                u16 manufacturing_date;
                u8  manufacturing_location;
                u8  reserved[31];
        } mapping[0];
};

static size_t sizeof_nfit_set_info(int num_mappings)
{
        return sizeof(struct nfit_set_info)
                + num_mappings * sizeof(struct nfit_set_info_map);
}

static size_t sizeof_nfit_set_info2(int num_mappings)
{
        return sizeof(struct nfit_set_info2)
                + num_mappings * sizeof(struct nfit_set_info_map2);
}

static int cmp_map_compat(const void *m0, const void *m1)
{
        const struct nfit_set_info_map *map0 = m0;
        const struct nfit_set_info_map *map1 = m1;

        return memcmp(&map0->region_offset, &map1->region_offset,
                        sizeof(u64));
}

static int cmp_map(const void *m0, const void *m1)
{
        const struct nfit_set_info_map *map0 = m0;
        const struct nfit_set_info_map *map1 = m1;

        if (map0->region_offset < map1->region_offset)
                return -1;
        else if (map0->region_offset > map1->region_offset)
                return 1;
        return 0;
}

static int cmp_map2(const void *m0, const void *m1)
{
        const struct nfit_set_info_map2 *map0 = m0;
        const struct nfit_set_info_map2 *map1 = m1;

        if (map0->region_offset < map1->region_offset)
                return -1;
        else if (map0->region_offset > map1->region_offset)
                return 1;
        return 0;
}

/* Retrieve the nth entry referencing this spa */
static struct acpi_nfit_memory_map *memdev_from_spa(
                struct acpi_nfit_desc *acpi_desc, u16 range_index, int n)
{
        struct nfit_memdev *nfit_memdev;

        list_for_each_entry(nfit_memdev, &acpi_desc->memdevs, list)
                if (nfit_memdev->memdev->range_index == range_index)
                        if (n-- == 0)
                                return nfit_memdev->memdev;
        return NULL;
}

static int acpi_nfit_init_interleave_set(struct acpi_nfit_desc *acpi_desc,
                struct nd_region_desc *ndr_desc,
                struct acpi_nfit_system_address *spa)
{
        struct device *dev = acpi_desc->dev;
        struct nd_interleave_set *nd_set;
        u16 nr = ndr_desc->num_mappings;
        struct nfit_set_info2 *info2;
        struct nfit_set_info *info;
        int i;

        nd_set = devm_kzalloc(dev, sizeof(*nd_set), GFP_KERNEL);
        if (!nd_set)
                return -ENOMEM;
        guid_copy(&nd_set->type_guid, (guid_t *) spa->range_guid);

        info = devm_kzalloc(dev, sizeof_nfit_set_info(nr), GFP_KERNEL);
        if (!info)
                return -ENOMEM;

        info2 = devm_kzalloc(dev, sizeof_nfit_set_info2(nr), GFP_KERNEL);
        if (!info2)
                return -ENOMEM;

        for (i = 0; i < nr; i++) {
                struct nd_mapping_desc *mapping = &ndr_desc->mapping[i];
                struct nfit_set_info_map *map = &info->mapping[i];
                struct nfit_set_info_map2 *map2 = &info2->mapping[i];
                struct nvdimm *nvdimm = mapping->nvdimm;
                struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
                struct acpi_nfit_memory_map *memdev = memdev_from_spa(acpi_desc,
                                spa->range_index, i);
                struct acpi_nfit_control_region *dcr = nfit_mem->dcr;

                if (!memdev || !nfit_mem->dcr) {
                        dev_err(dev, "%s: failed to find DCR\n", __func__);
                        return -ENODEV;
                }

                map->region_offset = memdev->region_offset;
                map->serial_number = dcr->serial_number;

                map2->region_offset = memdev->region_offset;
                map2->serial_number = dcr->serial_number;
                map2->vendor_id = dcr->vendor_id;
                map2->manufacturing_date = dcr->manufacturing_date;
                map2->manufacturing_location = dcr->manufacturing_location;
        }

        /* v1.1 namespaces */
        sort(&info->mapping[0], nr, sizeof(struct nfit_set_info_map),
                        cmp_map, NULL);
        nd_set->cookie1 = nd_fletcher64(info, sizeof_nfit_set_info(nr), 0);

        /* v1.2 namespaces */
        sort(&info2->mapping[0], nr, sizeof(struct nfit_set_info_map2),
                        cmp_map2, NULL);
        nd_set->cookie2 = nd_fletcher64(info2, sizeof_nfit_set_info2(nr), 0);

        /* support v1.1 namespaces created with the wrong sort order */
        sort(&info->mapping[0], nr, sizeof(struct nfit_set_info_map),
                        cmp_map_compat, NULL);
        nd_set->altcookie = nd_fletcher64(info, sizeof_nfit_set_info(nr), 0);

        /* record the result of the sort for the mapping position */
        for (i = 0; i < nr; i++) {
                struct nfit_set_info_map2 *map2 = &info2->mapping[i];
                int j;

                for (j = 0; j < nr; j++) {
                        struct nd_mapping_desc *mapping = &ndr_desc->mapping[j];
                        struct nvdimm *nvdimm = mapping->nvdimm;
                        struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
                        struct acpi_nfit_control_region *dcr = nfit_mem->dcr;

                        if (map2->serial_number == dcr->serial_number &&
                            map2->vendor_id == dcr->vendor_id &&
                            map2->manufacturing_date == dcr->manufacturing_date &&
                            map2->manufacturing_location
                                    == dcr->manufacturing_location) {
                                mapping->position = i;
                                break;
                        }
                }
        }

        ndr_desc->nd_set = nd_set;
        devm_kfree(dev, info);
        devm_kfree(dev, info2);

        return 0;
}

static u64 to_interleave_offset(u64 offset, struct nfit_blk_mmio *mmio)
{
        struct acpi_nfit_interleave *idt = mmio->idt;
        u32 sub_line_offset, line_index, line_offset;
        u64 line_no, table_skip_count, table_offset;

        line_no = div_u64_rem(offset, mmio->line_size, &sub_line_offset);
        table_skip_count = div_u64_rem(line_no, mmio->num_lines, &line_index);
        line_offset = idt->line_offset[line_index]
                * mmio->line_size;
        table_offset = table_skip_count * mmio->table_size;

        return mmio->base_offset + line_offset + table_offset + sub_line_offset;
}

static u32 read_blk_stat(struct nfit_blk *nfit_blk, unsigned int bw)
{
        struct nfit_blk_mmio *mmio = &nfit_blk->mmio[DCR];
        u64 offset = nfit_blk->stat_offset + mmio->size * bw;
        const u32 STATUS_MASK = 0x80000037;

        if (mmio->num_lines)
                offset = to_interleave_offset(offset, mmio);

        return readl(mmio->addr.base + offset) & STATUS_MASK;
}

static void write_blk_ctl(struct nfit_blk *nfit_blk, unsigned int bw,
                resource_size_t dpa, unsigned int len, unsigned int write)
{
        u64 cmd, offset;
        struct nfit_blk_mmio *mmio = &nfit_blk->mmio[DCR];

        enum {
                BCW_OFFSET_MASK = (1ULL << 48)-1,
                BCW_LEN_SHIFT = 48,
                BCW_LEN_MASK = (1ULL << 8) - 1,
                BCW_CMD_SHIFT = 56,
        };

        cmd = (dpa >> L1_CACHE_SHIFT) & BCW_OFFSET_MASK;
        len = len >> L1_CACHE_SHIFT;
        cmd |= ((u64) len & BCW_LEN_MASK) << BCW_LEN_SHIFT;
        cmd |= ((u64) write) << BCW_CMD_SHIFT;

        offset = nfit_blk->cmd_offset + mmio->size * bw;
        if (mmio->num_lines)
                offset = to_interleave_offset(offset, mmio);

        writeq(cmd, mmio->addr.base + offset);
        nvdimm_flush(nfit_blk->nd_region);

        if (nfit_blk->dimm_flags & NFIT_BLK_DCR_LATCH)
                readq(mmio->addr.base + offset);
}

static int acpi_nfit_blk_single_io(struct nfit_blk *nfit_blk,
                resource_size_t dpa, void *iobuf, size_t len, int rw,
                unsigned int lane)
{
        struct nfit_blk_mmio *mmio = &nfit_blk->mmio[BDW];
        unsigned int copied = 0;
        u64 base_offset;
        int rc;

        base_offset = nfit_blk->bdw_offset + dpa % L1_CACHE_BYTES
                + lane * mmio->size;
        write_blk_ctl(nfit_blk, lane, dpa, len, rw);
        while (len) {
                unsigned int c;
                u64 offset;

                if (mmio->num_lines) {
                        u32 line_offset;

                        offset = to_interleave_offset(base_offset + copied,
                                        mmio);
                        div_u64_rem(offset, mmio->line_size, &line_offset);
                        c = min_t(size_t, len, mmio->line_size - line_offset);
                } else {
                        offset = base_offset + nfit_blk->bdw_offset;
                        c = len;
                }

                if (rw)
                        memcpy_flushcache(mmio->addr.aperture + offset, iobuf + copied, c);
                else {
                        if (nfit_blk->dimm_flags & NFIT_BLK_READ_FLUSH)
                                arch_invalidate_pmem((void __force *)
                                        mmio->addr.aperture + offset, c);

                        memcpy(iobuf + copied, mmio->addr.aperture + offset, c);
                }

                copied += c;
                len -= c;
        }

        if (rw)
                nvdimm_flush(nfit_blk->nd_region);

        rc = read_blk_stat(nfit_blk, lane) ? -EIO : 0;
        return rc;
}

static int acpi_nfit_blk_region_do_io(struct nd_blk_region *ndbr,
                resource_size_t dpa, void *iobuf, u64 len, int rw)
{
        struct nfit_blk *nfit_blk = nd_blk_region_provider_data(ndbr);
        struct nfit_blk_mmio *mmio = &nfit_blk->mmio[BDW];
        struct nd_region *nd_region = nfit_blk->nd_region;
        unsigned int lane, copied = 0;
        int rc = 0;

        lane = nd_region_acquire_lane(nd_region);
        while (len) {
                u64 c = min(len, mmio->size);

                rc = acpi_nfit_blk_single_io(nfit_blk, dpa + copied,
                                iobuf + copied, c, rw, lane);
                if (rc)
                        break;

                copied += c;
                len -= c;
        }
        nd_region_release_lane(nd_region, lane);

        return rc;
}

static int nfit_blk_init_interleave(struct nfit_blk_mmio *mmio,
                struct acpi_nfit_interleave *idt, u16 interleave_ways)
{
        if (idt) {
                mmio->num_lines = idt->line_count;
                mmio->line_size = idt->line_size;
                if (interleave_ways == 0)
                        return -ENXIO;
                mmio->table_size = mmio->num_lines * interleave_ways
                        * mmio->line_size;
        }

        return 0;
}

static int acpi_nfit_blk_get_flags(struct nvdimm_bus_descriptor *nd_desc,
                struct nvdimm *nvdimm, struct nfit_blk *nfit_blk)
{
        struct nd_cmd_dimm_flags flags;
        int rc;

        memset(&flags, 0, sizeof(flags));
        rc = nd_desc->ndctl(nd_desc, nvdimm, ND_CMD_DIMM_FLAGS, &flags,
                        sizeof(flags), NULL);

        if (rc >= 0 && flags.status == 0)
                nfit_blk->dimm_flags = flags.flags;
        else if (rc == -ENOTTY) {
                /* fall back to a conservative default */
                nfit_blk->dimm_flags = NFIT_BLK_DCR_LATCH | NFIT_BLK_READ_FLUSH;
                rc = 0;
        } else
                rc = -ENXIO;

        return rc;
}

static int acpi_nfit_blk_region_enable(struct nvdimm_bus *nvdimm_bus,
                struct device *dev)
{
        struct nvdimm_bus_descriptor *nd_desc = to_nd_desc(nvdimm_bus);
        struct nd_blk_region *ndbr = to_nd_blk_region(dev);
        struct nfit_blk_mmio *mmio;
        struct nfit_blk *nfit_blk;
        struct nfit_mem *nfit_mem;
        struct nvdimm *nvdimm;
        int rc;

        nvdimm = nd_blk_region_to_dimm(ndbr);
        nfit_mem = nvdimm_provider_data(nvdimm);
        if (!nfit_mem || !nfit_mem->dcr || !nfit_mem->bdw) {
                dev_dbg(dev, "missing%s%s%s\n",
                                nfit_mem ? "" : " nfit_mem",
                                (nfit_mem && nfit_mem->dcr) ? "" : " dcr",
                                (nfit_mem && nfit_mem->bdw) ? "" : " bdw");
                return -ENXIO;
        }

        nfit_blk = devm_kzalloc(dev, sizeof(*nfit_blk), GFP_KERNEL);
        if (!nfit_blk)
                return -ENOMEM;
        nd_blk_region_set_provider_data(ndbr, nfit_blk);
        nfit_blk->nd_region = to_nd_region(dev);

        /* map block aperture memory */
        nfit_blk->bdw_offset = nfit_mem->bdw->offset;
        mmio = &nfit_blk->mmio[BDW];
        mmio->addr.base = devm_nvdimm_memremap(dev, nfit_mem->spa_bdw->address,
                        nfit_mem->spa_bdw->length, nd_blk_memremap_flags(ndbr));
        if (!mmio->addr.base) {
                dev_dbg(dev, "%s failed to map bdw\n",
                                nvdimm_name(nvdimm));
                return -ENOMEM;
        }
        mmio->size = nfit_mem->bdw->size;
        mmio->base_offset = nfit_mem->memdev_bdw->region_offset;
        mmio->idt = nfit_mem->idt_bdw;
        mmio->spa = nfit_mem->spa_bdw;
        rc = nfit_blk_init_interleave(mmio, nfit_mem->idt_bdw,
                        nfit_mem->memdev_bdw->interleave_ways);
        if (rc) {
                dev_dbg(dev, "%s failed to init bdw interleave\n",
                                nvdimm_name(nvdimm));
                return rc;
        }

        /* map block control memory */
        nfit_blk->cmd_offset = nfit_mem->dcr->command_offset;
        nfit_blk->stat_offset = nfit_mem->dcr->status_offset;
        mmio = &nfit_blk->mmio[DCR];
        mmio->addr.base = devm_nvdimm_ioremap(dev, nfit_mem->spa_dcr->address,
                        nfit_mem->spa_dcr->length);
        if (!mmio->addr.base) {
                dev_dbg(dev, "%s failed to map dcr\n",
                                nvdimm_name(nvdimm));
                return -ENOMEM;
        }
        mmio->size = nfit_mem->dcr->window_size;
        mmio->base_offset = nfit_mem->memdev_dcr->region_offset;
        mmio->idt = nfit_mem->idt_dcr;
        mmio->spa = nfit_mem->spa_dcr;
        rc = nfit_blk_init_interleave(mmio, nfit_mem->idt_dcr,
                        nfit_mem->memdev_dcr->interleave_ways);
        if (rc) {
                dev_dbg(dev, "%s failed to init dcr interleave\n",
                                nvdimm_name(nvdimm));
                return rc;
        }

        rc = acpi_nfit_blk_get_flags(nd_desc, nvdimm, nfit_blk);
        if (rc < 0) {
                dev_dbg(dev, "%s failed get DIMM flags\n",
                                nvdimm_name(nvdimm));
                return rc;
        }

        if (nvdimm_has_flush(nfit_blk->nd_region) < 0)
                dev_warn(dev, "unable to guarantee persistence of writes\n");

        if (mmio->line_size == 0)
                return 0;

        if ((u32) nfit_blk->cmd_offset % mmio->line_size
                        + 8 > mmio->line_size) {
                dev_dbg(dev, "cmd_offset crosses interleave boundary\n");
                return -ENXIO;
        } else if ((u32) nfit_blk->stat_offset % mmio->line_size
                        + 8 > mmio->line_size) {
                dev_dbg(dev, "stat_offset crosses interleave boundary\n");
                return -ENXIO;
        }

        return 0;
}

static int ars_get_cap(struct acpi_nfit_desc *acpi_desc,
                struct nd_cmd_ars_cap *cmd, struct nfit_spa *nfit_spa)
{
        struct nvdimm_bus_descriptor *nd_desc = &acpi_desc->nd_desc;
        struct acpi_nfit_system_address *spa = nfit_spa->spa;
        int cmd_rc, rc;

        cmd->address = spa->address;
        cmd->length = spa->length;
        rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_ARS_CAP, cmd,
                        sizeof(*cmd), &cmd_rc);
        if (rc < 0)
                return rc;
        return cmd_rc;
}

static int ars_start(struct acpi_nfit_desc *acpi_desc,
                struct nfit_spa *nfit_spa, enum nfit_ars_state req_type)
{
        int rc;
        int cmd_rc;
        struct nd_cmd_ars_start ars_start;
        struct acpi_nfit_system_address *spa = nfit_spa->spa;
        struct nvdimm_bus_descriptor *nd_desc = &acpi_desc->nd_desc;

        memset(&ars_start, 0, sizeof(ars_start));
        ars_start.address = spa->address;
        ars_start.length = spa->length;
        if (req_type == ARS_REQ_SHORT)
                ars_start.flags = ND_ARS_RETURN_PREV_DATA;
        if (nfit_spa_type(spa) == NFIT_SPA_PM)
                ars_start.type = ND_ARS_PERSISTENT;
        else if (nfit_spa_type(spa) == NFIT_SPA_VOLATILE)
                ars_start.type = ND_ARS_VOLATILE;
        else
                return -ENOTTY;

        rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_ARS_START, &ars_start,
                        sizeof(ars_start), &cmd_rc);

        if (rc < 0)
                return rc;
        if (cmd_rc < 0)
                return cmd_rc;
        set_bit(ARS_VALID, &acpi_desc->scrub_flags);
        return 0;
}

static int ars_continue(struct acpi_nfit_desc *acpi_desc)
{
        int rc, cmd_rc;
        struct nd_cmd_ars_start ars_start;
        struct nvdimm_bus_descriptor *nd_desc = &acpi_desc->nd_desc;
        struct nd_cmd_ars_status *ars_status = acpi_desc->ars_status;

        ars_start = (struct nd_cmd_ars_start) {
                .address = ars_status->restart_address,
                .length = ars_status->restart_length,
                .type = ars_status->type,
        };
        rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_ARS_START, &ars_start,
                        sizeof(ars_start), &cmd_rc);
        if (rc < 0)
                return rc;
        return cmd_rc;
}

static int ars_get_status(struct acpi_nfit_desc *acpi_desc)
{
        struct nvdimm_bus_descriptor *nd_desc = &acpi_desc->nd_desc;
        struct nd_cmd_ars_status *ars_status = acpi_desc->ars_status;
        int rc, cmd_rc;

        rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_ARS_STATUS, ars_status,
                        acpi_desc->max_ars, &cmd_rc);
        if (rc < 0)
                return rc;
        return cmd_rc;
}

static void ars_complete(struct acpi_nfit_desc *acpi_desc,
                struct nfit_spa *nfit_spa)
{
        struct nd_cmd_ars_status *ars_status = acpi_desc->ars_status;
        struct acpi_nfit_system_address *spa = nfit_spa->spa;
        struct nd_region *nd_region = nfit_spa->nd_region;
        struct device *dev;

        lockdep_assert_held(&acpi_desc->init_mutex);
        /*
         * Only advance the ARS state for ARS runs initiated by the
         * kernel, ignore ARS results from BIOS initiated runs for scrub
         * completion tracking.
         */
        if (acpi_desc->scrub_spa != nfit_spa)
                return;

        if ((ars_status->address >= spa->address && ars_status->address
                                < spa->address + spa->length)
                        || (ars_status->address < spa->address)) {
                /*
                 * Assume that if a scrub starts at an offset from the
                 * start of nfit_spa that we are in the continuation
                 * case.
                 *
                 * Otherwise, if the scrub covers the spa range, mark
                 * any pending request complete.
                 */
                if (ars_status->address + ars_status->length
                                >= spa->address + spa->length)
                                /* complete */;
                else
                        return;
        } else
                return;

        acpi_desc->scrub_spa = NULL;
        if (nd_region) {
                dev = nd_region_dev(nd_region);
                nvdimm_region_notify(nd_region, NVDIMM_REVALIDATE_POISON);
        } else
                dev = acpi_desc->dev;
        dev_dbg(dev, "ARS: range %d complete\n", spa->range_index);
}

static int ars_status_process_records(struct acpi_nfit_desc *acpi_desc)
{
        struct nvdimm_bus *nvdimm_bus = acpi_desc->nvdimm_bus;
        struct nd_cmd_ars_status *ars_status = acpi_desc->ars_status;
        int rc;
        u32 i;

        /*
         * First record starts at 44 byte offset from the start of the
         * payload.
         */
        if (ars_status->out_length < 44)
                return 0;

        /*
         * Ignore potentially stale results that are only refreshed
         * after a start-ARS event.
         */
        if (!test_and_clear_bit(ARS_VALID, &acpi_desc->scrub_flags)) {
                dev_dbg(acpi_desc->dev, "skip %d stale records\n",
                                ars_status->num_records);
                return 0;
        }

        for (i = 0; i < ars_status->num_records; i++) {
                /* only process full records */
                if (ars_status->out_length
                                < 44 + sizeof(struct nd_ars_record) * (i + 1))
                        break;
                rc = nvdimm_bus_add_badrange(nvdimm_bus,
                                ars_status->records[i].err_address,
                                ars_status->records[i].length);
                if (rc)
                        return rc;
        }
        if (i < ars_status->num_records)
                dev_warn(acpi_desc->dev, "detected truncated ars results\n");

        return 0;
}

static void acpi_nfit_remove_resource(void *data)
{
        struct resource *res = data;

        remove_resource(res);
}

static int acpi_nfit_insert_resource(struct acpi_nfit_desc *acpi_desc,
                struct nd_region_desc *ndr_desc)
{
        struct resource *res, *nd_res = ndr_desc->res;
        int is_pmem, ret;

        /* No operation if the region is already registered as PMEM */
        is_pmem = region_intersects(nd_res->start, resource_size(nd_res),
                                IORESOURCE_MEM, IORES_DESC_PERSISTENT_MEMORY);
        if (is_pmem == REGION_INTERSECTS)
                return 0;

        res = devm_kzalloc(acpi_desc->dev, sizeof(*res), GFP_KERNEL);
        if (!res)
                return -ENOMEM;

        res->name = "Persistent Memory";
        res->start = nd_res->start;
        res->end = nd_res->end;
        res->flags = IORESOURCE_MEM;
        res->desc = IORES_DESC_PERSISTENT_MEMORY;

        ret = insert_resource(&iomem_resource, res);
        if (ret)
                return ret;

        ret = devm_add_action_or_reset(acpi_desc->dev,
                                        acpi_nfit_remove_resource,
                                        res);
        if (ret)
                return ret;

        return 0;
}

static int acpi_nfit_init_mapping(struct acpi_nfit_desc *acpi_desc,
                struct nd_mapping_desc *mapping, struct nd_region_desc *ndr_desc,
                struct acpi_nfit_memory_map *memdev,
                struct nfit_spa *nfit_spa)
{
        struct nvdimm *nvdimm = acpi_nfit_dimm_by_handle(acpi_desc,
                        memdev->device_handle);
        struct acpi_nfit_system_address *spa = nfit_spa->spa;
        struct nd_blk_region_desc *ndbr_desc;
        struct nfit_mem *nfit_mem;
        int rc;

        if (!nvdimm) {
                dev_err(acpi_desc->dev, "spa%d dimm: %#x not found\n",
                                spa->range_index, memdev->device_handle);
                return -ENODEV;
        }

        mapping->nvdimm = nvdimm;
        switch (nfit_spa_type(spa)) {
        case NFIT_SPA_PM:
        case NFIT_SPA_VOLATILE:
                mapping->start = memdev->address;
                mapping->size = memdev->region_size;
                break;
        case NFIT_SPA_DCR:
                nfit_mem = nvdimm_provider_data(nvdimm);
                if (!nfit_mem || !nfit_mem->bdw) {
                        dev_dbg(acpi_desc->dev, "spa%d %s missing bdw\n",
                                        spa->range_index, nvdimm_name(nvdimm));
                        break;
                }

                mapping->size = nfit_mem->bdw->capacity;
                mapping->start = nfit_mem->bdw->start_address;
                ndr_desc->num_lanes = nfit_mem->bdw->windows;
                ndr_desc->mapping = mapping;
                ndr_desc->num_mappings = 1;
                ndbr_desc = to_blk_region_desc(ndr_desc);
                ndbr_desc->enable = acpi_nfit_blk_region_enable;
                ndbr_desc->do_io = acpi_desc->blk_do_io;
                rc = acpi_nfit_init_interleave_set(acpi_desc, ndr_desc, spa);
                if (rc)
                        return rc;
                nfit_spa->nd_region = nvdimm_blk_region_create(acpi_desc->nvdimm_bus,
                                ndr_desc);
                if (!nfit_spa->nd_region)
                        return -ENOMEM;
                break;
        }

        return 0;
}

static bool nfit_spa_is_virtual(struct acpi_nfit_system_address *spa)
{
        return (nfit_spa_type(spa) == NFIT_SPA_VDISK ||
                nfit_spa_type(spa) == NFIT_SPA_VCD   ||
                nfit_spa_type(spa) == NFIT_SPA_PDISK ||
                nfit_spa_type(spa) == NFIT_SPA_PCD);
}

static bool nfit_spa_is_volatile(struct acpi_nfit_system_address *spa)
{
        return (nfit_spa_type(spa) == NFIT_SPA_VDISK ||
                nfit_spa_type(spa) == NFIT_SPA_VCD   ||
                nfit_spa_type(spa) == NFIT_SPA_VOLATILE);
}

static int acpi_nfit_register_region(struct acpi_nfit_desc *acpi_desc,
                struct nfit_spa *nfit_spa)
{
        static struct nd_mapping_desc mappings[ND_MAX_MAPPINGS];
        struct acpi_nfit_system_address *spa = nfit_spa->spa;
        struct nd_blk_region_desc ndbr_desc;
        struct nd_region_desc *ndr_desc;
        struct nfit_memdev *nfit_memdev;
        struct nvdimm_bus *nvdimm_bus;
        struct resource res;
        int count = 0, rc;

        if (nfit_spa->nd_region)
                return 0;

        if (spa->range_index == 0 && !nfit_spa_is_virtual(spa)) {
                dev_dbg(acpi_desc->dev, "detected invalid spa index\n");
                return 0;
        }

        memset(&res, 0, sizeof(res));
        memset(&mappings, 0, sizeof(mappings));
        memset(&ndbr_desc, 0, sizeof(ndbr_desc));
        res.start = spa->address;
        res.end = res.start + spa->length - 1;
        ndr_desc = &ndbr_desc.ndr_desc;
        ndr_desc->res = &res;
        ndr_desc->provider_data = nfit_spa;
        ndr_desc->attr_groups = acpi_nfit_region_attribute_groups;
        if (spa->flags & ACPI_NFIT_PROXIMITY_VALID) {
                ndr_desc->numa_node = acpi_map_pxm_to_online_node(
                                                spa->proximity_domain);
                ndr_desc->target_node = acpi_map_pxm_to_node(
                                spa->proximity_domain);
        } else {
                ndr_desc->numa_node = NUMA_NO_NODE;
                ndr_desc->target_node = NUMA_NO_NODE;
        }

        /*
         * Persistence domain bits are hierarchical, if
         * ACPI_NFIT_CAPABILITY_CACHE_FLUSH is set then
         * ACPI_NFIT_CAPABILITY_MEM_FLUSH is implied.
         */
        if (acpi_desc->platform_cap & ACPI_NFIT_CAPABILITY_CACHE_FLUSH)
                set_bit(ND_REGION_PERSIST_CACHE, &ndr_desc->flags);
        else if (acpi_desc->platform_cap & ACPI_NFIT_CAPABILITY_MEM_FLUSH)
                set_bit(ND_REGION_PERSIST_MEMCTRL, &ndr_desc->flags);

        list_for_each_entry(nfit_memdev, &acpi_desc->memdevs, list) {
                struct acpi_nfit_memory_map *memdev = nfit_memdev->memdev;
                struct nd_mapping_desc *mapping;

                if (memdev->range_index != spa->range_index)
                        continue;
                if (count >= ND_MAX_MAPPINGS) {
                        dev_err(acpi_desc->dev, "spa%d exceeds max mappings %d\n",
                                        spa->range_index, ND_MAX_MAPPINGS);
                        return -ENXIO;
                }
                mapping = &mappings[count++];
                rc = acpi_nfit_init_mapping(acpi_desc, mapping, ndr_desc,
                                memdev, nfit_spa);
                if (rc)
                        goto out;
        }

        ndr_desc->mapping = mappings;
        ndr_desc->num_mappings = count;
        rc = acpi_nfit_init_interleave_set(acpi_desc, ndr_desc, spa);
        if (rc)