// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/moduleparam.h>
#include <linux/vmalloc.h>
#include <linux/device.h>
#include <linux/ndctl.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include "nd-core.h"
#include "label.h"
#include "pmem.h"
#include "nd.h"

static DEFINE_IDA(dimm_ida);

/*
 * Retrieve bus and dimm handle and return if this bus supports
 * get_config_data commands
 */
int nvdimm_check_config_data(struct device *dev)
{
        struct nvdimm *nvdimm = to_nvdimm(dev);

        if (!nvdimm->cmd_mask ||
            !test_bit(ND_CMD_GET_CONFIG_DATA, &nvdimm->cmd_mask)) {
                if (test_bit(NDD_LABELING, &nvdimm->flags))
                        return -ENXIO;
                else
                        return -ENOTTY;
        }

        return 0;
}

static int validate_dimm(struct nvdimm_drvdata *ndd)
{
        int rc;

        if (!ndd)
                return -EINVAL;

        rc = nvdimm_check_config_data(ndd->dev);
        if (rc)
                dev_dbg(ndd->dev, "%ps: %s error: %d\n",
                                __builtin_return_address(0), __func__, rc);
        return rc;
}

/**
 * nvdimm_init_nsarea - determine the geometry of a dimm's namespace area
 * @ndd: dimm to initialize
 *
 * Returns: %0 if the area is already valid, -errno on error
 */
int nvdimm_init_nsarea(struct nvdimm_drvdata *ndd)
{
        struct nd_cmd_get_config_size *cmd = &ndd->nsarea;
        struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(ndd->dev);
        struct nvdimm_bus_descriptor *nd_desc;
        int rc = validate_dimm(ndd);
        int cmd_rc = 0;

        if (rc)
                return rc;

        if (cmd->config_size)
                return 0; /* already valid */

        memset(cmd, 0, sizeof(*cmd));
        nd_desc = nvdimm_bus->nd_desc;
        rc = nd_desc->ndctl(nd_desc, to_nvdimm(ndd->dev),
                        ND_CMD_GET_CONFIG_SIZE, cmd, sizeof(*cmd), &cmd_rc);
        if (rc < 0)
                return rc;
        return cmd_rc;
}

int nvdimm_get_config_data(struct nvdimm_drvdata *ndd, void *buf,
                           size_t offset, size_t len)
{
        struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(ndd->dev);
        struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
        int rc = validate_dimm(ndd), cmd_rc = 0;
        struct nd_cmd_get_config_data_hdr *cmd;
        size_t max_cmd_size, buf_offset;

        if (rc)
                return rc;

        if (offset + len > ndd->nsarea.config_size)
                return -ENXIO;

        max_cmd_size = min_t(u32, len, ndd->nsarea.max_xfer);
        cmd = kvzalloc(max_cmd_size + sizeof(*cmd), GFP_KERNEL);
        if (!cmd)
                return -ENOMEM;

        for (buf_offset = 0; len;
             len -= cmd->in_length, buf_offset += cmd->in_length) {
                size_t cmd_size;

                cmd->in_offset = offset + buf_offset;
                cmd->in_length = min(max_cmd_size, len);

                cmd_size = sizeof(*cmd) + cmd->in_length;

                rc = nd_desc->ndctl(nd_desc, to_nvdimm(ndd->dev),
                                ND_CMD_GET_CONFIG_DATA, cmd, cmd_size, &cmd_rc);
                if (rc < 0)
                        break;
                if (cmd_rc < 0) {
                        rc = cmd_rc;
                        break;
                }

                /* out_buf should be valid, copy it into our output buffer */
                memcpy(buf + buf_offset, cmd->out_buf, cmd->in_length);
        }
        kvfree(cmd);

        return rc;
}

int nvdimm_set_config_data(struct nvdimm_drvdata *ndd, size_t offset,
                void *buf, size_t len)
{
        size_t max_cmd_size, buf_offset;
        struct nd_cmd_set_config_hdr *cmd;
        int rc = validate_dimm(ndd), cmd_rc = 0;
        struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(ndd->dev);
        struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;

        if (rc)
                return rc;

        if (offset + len > ndd->nsarea.config_size)
                return -ENXIO;

        max_cmd_size = min_t(u32, len, ndd->nsarea.max_xfer);
        cmd = kvzalloc(max_cmd_size + sizeof(*cmd) + sizeof(u32), GFP_KERNEL);
        if (!cmd)
                return -ENOMEM;

        for (buf_offset = 0; len; len -= cmd->in_length,
                        buf_offset += cmd->in_length) {
                size_t cmd_size;

                cmd->in_offset = offset + buf_offset;
                cmd->in_length = min(max_cmd_size, len);
                memcpy(cmd->in_buf, buf + buf_offset, cmd->in_length);

                /* status is output in the last 4-bytes of the command buffer */
                cmd_size = sizeof(*cmd) + cmd->in_length + sizeof(u32);

                rc = nd_desc->ndctl(nd_desc, to_nvdimm(ndd->dev),
                                ND_CMD_SET_CONFIG_DATA, cmd, cmd_size, &cmd_rc);
                if (rc < 0)
                        break;
                if (cmd_rc < 0) {
                        rc = cmd_rc;
                        break;
                }
        }
        kvfree(cmd);

        return rc;
}

void nvdimm_set_labeling(struct device *dev)
{
        struct nvdimm *nvdimm = to_nvdimm(dev);

        set_bit(NDD_LABELING, &nvdimm->flags);
}

void nvdimm_set_locked(struct device *dev)
{
        struct nvdimm *nvdimm = to_nvdimm(dev);

        set_bit(NDD_LOCKED, &nvdimm->flags);
}

void nvdimm_clear_locked(struct device *dev)
{
        struct nvdimm *nvdimm = to_nvdimm(dev);

        clear_bit(NDD_LOCKED, &nvdimm->flags);
}

static void nvdimm_release(struct device *dev)
{
        struct nvdimm *nvdimm = to_nvdimm(dev);

        ida_free(&dimm_ida, nvdimm->id);
        kfree(nvdimm);
}

struct nvdimm *to_nvdimm(struct device *dev)
{
        struct nvdimm *nvdimm = container_of(dev, struct nvdimm, dev);

        WARN_ON(!is_nvdimm(dev));
        return nvdimm;
}
EXPORT_SYMBOL_GPL(to_nvdimm);

struct nvdimm_drvdata *to_ndd(struct nd_mapping *nd_mapping)
{
        struct nvdimm *nvdimm = nd_mapping->nvdimm;

        WARN_ON_ONCE(!is_nvdimm_bus_locked(&nvdimm->dev));

        return dev_get_drvdata(&nvdimm->dev);
}
EXPORT_SYMBOL(to_ndd);

void nvdimm_drvdata_release(struct kref *kref)
{
        struct nvdimm_drvdata *ndd = container_of(kref, typeof(*ndd), kref);
        struct device *dev = ndd->dev;
        struct resource *res, *_r;

        dev_dbg(dev, "trace\n");
        scoped_guard(nvdimm_bus, dev) {
                for_each_dpa_resource_safe(ndd, res, _r)
                        nvdimm_free_dpa(ndd, res);
        }

        kvfree(ndd->data);
        kfree(ndd);
        put_device(dev);
}

void get_ndd(struct nvdimm_drvdata *ndd)
{
        kref_get(&ndd->kref);
}

void put_ndd(struct nvdimm_drvdata *ndd)
{
        if (ndd)
                kref_put(&ndd->kref, nvdimm_drvdata_release);
}

const char *nvdimm_name(struct nvdimm *nvdimm)
{
        return dev_name(&nvdimm->dev);
}
EXPORT_SYMBOL_GPL(nvdimm_name);

struct kobject *nvdimm_kobj(struct nvdimm *nvdimm)
{
        return &nvdimm->dev.kobj;
}
EXPORT_SYMBOL_GPL(nvdimm_kobj);

unsigned long nvdimm_cmd_mask(struct nvdimm *nvdimm)
{
        return nvdimm->cmd_mask;
}
EXPORT_SYMBOL_GPL(nvdimm_cmd_mask);

void *nvdimm_provider_data(struct nvdimm *nvdimm)
{
        if (nvdimm)
                return nvdimm->provider_data;
        return NULL;
}
EXPORT_SYMBOL_GPL(nvdimm_provider_data);

static ssize_t commands_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct nvdimm *nvdimm = to_nvdimm(dev);
        int cmd, len = 0;

        if (!nvdimm->cmd_mask)
                return sprintf(buf, "\n");

        for_each_set_bit(cmd, &nvdimm->cmd_mask, BITS_PER_LONG)
                len += sprintf(buf + len, "%s ", nvdimm_cmd_name(cmd));
        len += sprintf(buf + len, "\n");
        return len;
}
static DEVICE_ATTR_RO(commands);

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

        return sprintf(buf, "%s%s\n",
                        test_bit(NDD_LABELING, &nvdimm->flags) ? "label " : "",
                        test_bit(NDD_LOCKED, &nvdimm->flags) ? "lock " : "");
}
static DEVICE_ATTR_RO(flags);

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

        /*
         * The state may be in the process of changing, userspace should
         * quiesce probing if it wants a static answer
         */
        nvdimm_bus_lock(dev);
        nvdimm_bus_unlock(dev);
        return sprintf(buf, "%s\n", atomic_read(&nvdimm->busy)
                        ? "active" : "idle");
}
static DEVICE_ATTR_RO(state);

static ssize_t __available_slots_show(struct nvdimm_drvdata *ndd, char *buf)
{
        struct device *dev;
        u32 nfree;

        if (!ndd)
                return -ENXIO;

        dev = ndd->dev;
        guard(nvdimm_bus)(dev);
        nfree = nd_label_nfree(ndd);
        if (nfree - 1 > nfree) {
                dev_WARN_ONCE(dev, 1, "we ate our last label?\n");
                nfree = 0;
        } else
                nfree--;
        return sprintf(buf, "%d\n", nfree);
}

static ssize_t available_slots_show(struct device *dev,
                                    struct device_attribute *attr, char *buf)
{
        ssize_t rc;

        device_lock(dev);
        rc = __available_slots_show(dev_get_drvdata(dev), buf);
        device_unlock(dev);

        return rc;
}
static DEVICE_ATTR_RO(available_slots);

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

        /*
         * For the test version we need to poll the "hardware" in order
         * to get the updated status for unlock testing.
         */
        if (IS_ENABLED(CONFIG_NVDIMM_SECURITY_TEST))
                nvdimm->sec.flags = nvdimm_security_flags(nvdimm, NVDIMM_USER);

        if (test_bit(NVDIMM_SECURITY_OVERWRITE, &nvdimm->sec.flags))
                return sprintf(buf, "overwrite\n");
        if (test_bit(NVDIMM_SECURITY_DISABLED, &nvdimm->sec.flags))
                return sprintf(buf, "disabled\n");
        if (test_bit(NVDIMM_SECURITY_UNLOCKED, &nvdimm->sec.flags))
                return sprintf(buf, "unlocked\n");
        if (test_bit(NVDIMM_SECURITY_LOCKED, &nvdimm->sec.flags))
                return sprintf(buf, "locked\n");
        return -ENOTTY;
}

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

        return sprintf(buf, "%d\n", test_bit(NVDIMM_SECURITY_FROZEN,
                                &nvdimm->sec.flags));
}
static DEVICE_ATTR_RO(frozen);

static ssize_t security_store(struct device *dev,
                struct device_attribute *attr, const char *buf, size_t len)

{
        /*
         * Require all userspace triggered security management to be
         * done while probing is idle and the DIMM is not in active use
         * in any region.
         */
        guard(device)(dev);
        guard(nvdimm_bus)(dev);
        wait_nvdimm_bus_probe_idle(dev);
        return nvdimm_security_store(dev, buf, len);
}
static DEVICE_ATTR_RW(security);

static struct attribute *nvdimm_attributes[] = {
        &dev_attr_state.attr,
        &dev_attr_flags.attr,
        &dev_attr_commands.attr,
        &dev_attr_available_slots.attr,
        &dev_attr_security.attr,
        &dev_attr_frozen.attr,
        NULL,
};

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

        if (a != &dev_attr_security.attr && a != &dev_attr_frozen.attr)
                return a->mode;
        if (!nvdimm->sec.flags)
                return 0;

        if (a == &dev_attr_security.attr) {
                /* Are there any state mutation ops (make writable)? */
                if (nvdimm->sec.ops->freeze || nvdimm->sec.ops->disable
                                || nvdimm->sec.ops->change_key
                                || nvdimm->sec.ops->erase
                                || nvdimm->sec.ops->overwrite)
                        return a->mode;
                return 0444;
        }

        if (nvdimm->sec.ops->freeze)
                return a->mode;
        return 0;
}

static const struct attribute_group nvdimm_attribute_group = {
        .attrs = nvdimm_attributes,
        .is_visible = nvdimm_visible,
};

static ssize_t result_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct nvdimm *nvdimm = to_nvdimm(dev);
        enum nvdimm_fwa_result result;

        if (!nvdimm->fw_ops)
                return -EOPNOTSUPP;

        guard(nvdimm_bus)(dev);
        result = nvdimm->fw_ops->activate_result(nvdimm);

        switch (result) {
        case NVDIMM_FWA_RESULT_NONE:
                return sprintf(buf, "none\n");
        case NVDIMM_FWA_RESULT_SUCCESS:
                return sprintf(buf, "success\n");
        case NVDIMM_FWA_RESULT_FAIL:
                return sprintf(buf, "fail\n");
        case NVDIMM_FWA_RESULT_NOTSTAGED:
                return sprintf(buf, "not_staged\n");
        case NVDIMM_FWA_RESULT_NEEDRESET:
                return sprintf(buf, "need_reset\n");
        default:
                return -ENXIO;
        }
}
static DEVICE_ATTR_ADMIN_RO(result);

static ssize_t activate_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct nvdimm *nvdimm = to_nvdimm(dev);
        enum nvdimm_fwa_state state;

        if (!nvdimm->fw_ops)
                return -EOPNOTSUPP;

        guard(nvdimm_bus)(dev);
        state = nvdimm->fw_ops->activate_state(nvdimm);

        switch (state) {
        case NVDIMM_FWA_IDLE:
                return sprintf(buf, "idle\n");
        case NVDIMM_FWA_BUSY:
                return sprintf(buf, "busy\n");
        case NVDIMM_FWA_ARMED:
                return sprintf(buf, "armed\n");
        default:
                return -ENXIO;
        }
}

static ssize_t activate_store(struct device *dev, struct device_attribute *attr,
                const char *buf, size_t len)
{
        struct nvdimm *nvdimm = to_nvdimm(dev);
        enum nvdimm_fwa_trigger arg;
        int rc;

        if (!nvdimm->fw_ops)
                return -EOPNOTSUPP;

        if (sysfs_streq(buf, "arm"))
                arg = NVDIMM_FWA_ARM;
        else if (sysfs_streq(buf, "disarm"))
                arg = NVDIMM_FWA_DISARM;
        else
                return -EINVAL;

        guard(nvdimm_bus)(dev);
        rc = nvdimm->fw_ops->arm(nvdimm, arg);

        if (rc < 0)
                return rc;
        return len;
}
static DEVICE_ATTR_ADMIN_RW(activate);

static struct attribute *nvdimm_firmware_attributes[] = {
        &dev_attr_activate.attr,
        &dev_attr_result.attr,
        NULL,
};

static umode_t nvdimm_firmware_visible(struct kobject *kobj, struct attribute *a, int n)
{
        struct device *dev = container_of(kobj, typeof(*dev), kobj);
        struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
        struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
        struct nvdimm *nvdimm = to_nvdimm(dev);
        enum nvdimm_fwa_capability cap;

        if (!nd_desc->fw_ops)
                return 0;
        if (!nvdimm->fw_ops)
                return 0;

        guard(nvdimm_bus)(dev);
        cap = nd_desc->fw_ops->capability(nd_desc);

        if (cap < NVDIMM_FWA_CAP_QUIESCE)
                return 0;

        return a->mode;
}

static const struct attribute_group nvdimm_firmware_attribute_group = {
        .name = "firmware",
        .attrs = nvdimm_firmware_attributes,
        .is_visible = nvdimm_firmware_visible,
};

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

static const struct device_type nvdimm_device_type = {
        .name = "nvdimm",
        .release = nvdimm_release,
        .groups = nvdimm_attribute_groups,
};

bool is_nvdimm(const struct device *dev)
{
        return dev->type == &nvdimm_device_type;
}

static struct lock_class_key nvdimm_key;

struct nvdimm *__nvdimm_create(struct nvdimm_bus *nvdimm_bus,
                void *provider_data, const struct attribute_group **groups,
                unsigned long flags, unsigned long cmd_mask, int num_flush,
                struct resource *flush_wpq, const char *dimm_id,
                const struct nvdimm_security_ops *sec_ops,
                const struct nvdimm_fw_ops *fw_ops)
{
        struct nvdimm *nvdimm = kzalloc_obj(*nvdimm);
        struct device *dev;

        if (!nvdimm)
                return NULL;

        nvdimm->id = ida_alloc(&dimm_ida, GFP_KERNEL);
        if (nvdimm->id < 0) {
                kfree(nvdimm);
                return NULL;
        }

        nvdimm->dimm_id = dimm_id;
        nvdimm->provider_data = provider_data;
        nvdimm->flags = flags;
        nvdimm->cmd_mask = cmd_mask;
        nvdimm->num_flush = num_flush;
        nvdimm->flush_wpq = flush_wpq;
        atomic_set(&nvdimm->busy, 0);
        dev = &nvdimm->dev;
        dev_set_name(dev, "nmem%d", nvdimm->id);
        dev->parent = &nvdimm_bus->dev;
        dev->type = &nvdimm_device_type;
        dev->devt = MKDEV(nvdimm_major, nvdimm->id);
        dev->groups = groups;
        nvdimm->sec.ops = sec_ops;
        nvdimm->fw_ops = fw_ops;
        nvdimm->sec.overwrite_tmo = 0;
        INIT_DELAYED_WORK(&nvdimm->dwork, nvdimm_security_overwrite_query);
        /*
         * Security state must be initialized before device_add() for
         * attribute visibility.
         */
        /* get security state and extended (master) state */
        nvdimm->sec.flags = nvdimm_security_flags(nvdimm, NVDIMM_USER);
        nvdimm->sec.ext_flags = nvdimm_security_flags(nvdimm, NVDIMM_MASTER);
        device_initialize(dev);
        lockdep_set_class(&dev->mutex, &nvdimm_key);
        if (test_bit(NDD_REGISTER_SYNC, &flags))
                nd_device_register_sync(dev);
        else
                nd_device_register(dev);

        return nvdimm;
}
EXPORT_SYMBOL_GPL(__nvdimm_create);

void nvdimm_delete(struct nvdimm *nvdimm)
{
        struct device *dev = &nvdimm->dev;
        bool dev_put = false;

        /* We are shutting down. Make state frozen artificially. */
        scoped_guard(nvdimm_bus, dev) {
                set_bit(NVDIMM_SECURITY_FROZEN, &nvdimm->sec.flags);
                dev_put = test_and_clear_bit(NDD_WORK_PENDING, &nvdimm->flags);
        }
        cancel_delayed_work_sync(&nvdimm->dwork);
        if (dev_put)
                put_device(dev);
        nd_device_unregister(dev, ND_SYNC);
}
EXPORT_SYMBOL_GPL(nvdimm_delete);

static void shutdown_security_notify(void *data)
{
        struct nvdimm *nvdimm = data;

        sysfs_put(nvdimm->sec.overwrite_state);
}

int nvdimm_security_setup_events(struct device *dev)
{
        struct nvdimm *nvdimm = to_nvdimm(dev);

        if (!nvdimm->sec.flags || !nvdimm->sec.ops
                        || !nvdimm->sec.ops->overwrite)
                return 0;
        nvdimm->sec.overwrite_state = sysfs_get_dirent(dev->kobj.sd, "security");
        if (!nvdimm->sec.overwrite_state)
                return -ENOMEM;

        return devm_add_action_or_reset(dev, shutdown_security_notify, nvdimm);
}
EXPORT_SYMBOL_GPL(nvdimm_security_setup_events);

int nvdimm_in_overwrite(struct nvdimm *nvdimm)
{
        return test_bit(NDD_SECURITY_OVERWRITE, &nvdimm->flags);
}
EXPORT_SYMBOL_GPL(nvdimm_in_overwrite);

int nvdimm_security_freeze(struct nvdimm *nvdimm)
{
        int rc;

        WARN_ON_ONCE(!is_nvdimm_bus_locked(&nvdimm->dev));

        if (!nvdimm->sec.ops || !nvdimm->sec.ops->freeze)
                return -EOPNOTSUPP;

        if (!nvdimm->sec.flags)
                return -EIO;

        if (test_bit(NDD_SECURITY_OVERWRITE, &nvdimm->flags)) {
                dev_warn(&nvdimm->dev, "Overwrite operation in progress.\n");
                return -EBUSY;
        }

        rc = nvdimm->sec.ops->freeze(nvdimm);
        nvdimm->sec.flags = nvdimm_security_flags(nvdimm, NVDIMM_USER);

        return rc;
}

static unsigned long dpa_align(struct nd_region *nd_region)
{
        struct device *dev = &nd_region->dev;

        if (dev_WARN_ONCE(dev, !is_nvdimm_bus_locked(dev),
                                "bus lock required for capacity provision\n"))
                return 0;
        if (dev_WARN_ONCE(dev, !nd_region->ndr_mappings || nd_region->align
                                % nd_region->ndr_mappings,
                                "invalid region align %#lx mappings: %d\n",
                                nd_region->align, nd_region->ndr_mappings))
                return 0;
        return nd_region->align / nd_region->ndr_mappings;
}

/**
 * nd_pmem_max_contiguous_dpa - For the given dimm+region, return the max
 *                         contiguous unallocated dpa range.
 * @nd_region: constrain available space check to this reference region
 * @nd_mapping: container of dpa-resource-root + labels
 *
 * Returns: %0 if there is an alignment error, otherwise the max
 *              unallocated dpa range
 */
resource_size_t nd_pmem_max_contiguous_dpa(struct nd_region *nd_region,
                                           struct nd_mapping *nd_mapping)
{
        struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
        struct nvdimm_bus *nvdimm_bus;
        resource_size_t max = 0;
        struct resource *res;
        unsigned long align;

        /* if a dimm is disabled the available capacity is zero */
        if (!ndd)
                return 0;

        align = dpa_align(nd_region);
        if (!align)
                return 0;

        nvdimm_bus = walk_to_nvdimm_bus(ndd->dev);
        if (__reserve_free_pmem(&nd_region->dev, nd_mapping->nvdimm))
                return 0;
        for_each_dpa_resource(ndd, res) {
                resource_size_t start, end;

                if (strcmp(res->name, "pmem-reserve") != 0)
                        continue;
                /* trim free space relative to current alignment setting */
                start = ALIGN(res->start, align);
                end = ALIGN_DOWN(res->end + 1, align) - 1;
                if (end < start)
                        continue;
                if (end - start + 1 > max)
                        max = end - start + 1;
        }
        release_free_pmem(nvdimm_bus, nd_mapping);
        return max;
}

/**
 * nd_pmem_available_dpa - for the given dimm+region account unallocated dpa
 * @nd_mapping: container of dpa-resource-root + labels
 * @nd_region: constrain available space check to this reference region
 *
 * Validate that a PMEM label, if present, aligns with the start of an
 * interleave set.
 *
 * Returns: %0 if there is an alignment error, otherwise the unallocated dpa
 */
resource_size_t nd_pmem_available_dpa(struct nd_region *nd_region,
                                      struct nd_mapping *nd_mapping)
{
        struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
        resource_size_t map_start, map_end, busy = 0;
        struct resource *res;
        unsigned long align;

        if (!ndd)
                return 0;

        align = dpa_align(nd_region);
        if (!align)
                return 0;

        map_start = nd_mapping->start;
        map_end = map_start + nd_mapping->size - 1;
        for_each_dpa_resource(ndd, res) {
                resource_size_t start, end;

                start = ALIGN_DOWN(res->start, align);
                end = ALIGN(res->end + 1, align) - 1;
                if (start >= map_start && start < map_end) {
                        if (end > map_end) {
                                nd_dbg_dpa(nd_region, ndd, res,
                                           "misaligned to iset\n");
                                return 0;
                        }
                        busy += end - start + 1;
                } else if (end >= map_start && end <= map_end) {
                        busy += end - start + 1;
                } else if (map_start > start && map_start < end) {
                        /* total eclipse of the mapping */
                        busy += nd_mapping->size;
                }
        }

        if (busy < nd_mapping->size)
                return ALIGN_DOWN(nd_mapping->size - busy, align);
        return 0;
}

void nvdimm_free_dpa(struct nvdimm_drvdata *ndd, struct resource *res)
{
        WARN_ON_ONCE(!is_nvdimm_bus_locked(ndd->dev));
        kfree(res->name);
        __release_region(&ndd->dpa, res->start, resource_size(res));
}

struct resource *nvdimm_allocate_dpa(struct nvdimm_drvdata *ndd,
                struct nd_label_id *label_id, resource_size_t start,
                resource_size_t n)
{
        char *name = kmemdup(label_id, sizeof(*label_id), GFP_KERNEL);
        struct resource *res;

        if (!name)
                return NULL;

        WARN_ON_ONCE(!is_nvdimm_bus_locked(ndd->dev));
        res = __request_region(&ndd->dpa, start, n, name, 0);
        if (!res)
                kfree(name);
        return res;
}

/**
 * nvdimm_allocated_dpa - sum up the dpa currently allocated to this label_id
 * @ndd: container of dpa-resource-root + labels
 * @label_id: dpa resource name of the form pmem-<human readable uuid>
 *
 * Returns: sum of the dpa allocated to the label_id
 */
resource_size_t nvdimm_allocated_dpa(struct nvdimm_drvdata *ndd,
                struct nd_label_id *label_id)
{
        resource_size_t allocated = 0;
        struct resource *res;

        for_each_dpa_resource(ndd, res)
                if (strcmp(res->name, label_id->id) == 0)
                        allocated += resource_size(res);

        return allocated;
}

static int count_dimms(struct device *dev, void *c)
{
        int *count = c;

        if (is_nvdimm(dev))
                (*count)++;
        return 0;
}

int nvdimm_bus_check_dimm_count(struct nvdimm_bus *nvdimm_bus, int dimm_count)
{
        int count = 0;
        /* Flush any possible dimm registration failures */
        nd_synchronize();

        device_for_each_child(&nvdimm_bus->dev, &count, count_dimms);
        dev_dbg(&nvdimm_bus->dev, "count: %d\n", count);
        if (count != dimm_count)
                return -ENXIO;
        return 0;
}
EXPORT_SYMBOL_GPL(nvdimm_bus_check_dimm_count);

void __exit nvdimm_devs_exit(void)
{
        ida_destroy(&dimm_ida);
}