// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright(c) 2013-2016 Intel Corporation. All rights reserved.
 */
#include <linux/device.h>
#include <linux/sizes.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include "nd-core.h"
#include "pfn.h"
#include "nd.h"

static void nd_dax_release(struct device *dev)
{
        struct nd_region *nd_region = to_nd_region(dev->parent);
        struct nd_dax *nd_dax = to_nd_dax(dev);
        struct nd_pfn *nd_pfn = &nd_dax->nd_pfn;

        dev_dbg(dev, "trace\n");
        nd_detach_ndns(dev, &nd_pfn->ndns);
        ida_free(&nd_region->dax_ida, nd_pfn->id);
        kfree(nd_pfn->uuid);
        kfree(nd_dax);
}

struct nd_dax *to_nd_dax(struct device *dev)
{
        struct nd_dax *nd_dax = container_of(dev, struct nd_dax, nd_pfn.dev);

        WARN_ON(!is_nd_dax(dev));
        return nd_dax;
}
EXPORT_SYMBOL(to_nd_dax);

static const struct device_type nd_dax_device_type = {
        .name = "nd_dax",
        .release = nd_dax_release,
        .groups = nd_pfn_attribute_groups,
};

bool is_nd_dax(const struct device *dev)
{
        return dev ? dev->type == &nd_dax_device_type : false;
}
EXPORT_SYMBOL(is_nd_dax);

static struct nd_dax *nd_dax_alloc(struct nd_region *nd_region)
{
        struct nd_pfn *nd_pfn;
        struct nd_dax *nd_dax;
        struct device *dev;

        nd_dax = kzalloc_obj(*nd_dax);
        if (!nd_dax)
                return NULL;

        nd_pfn = &nd_dax->nd_pfn;
        nd_pfn->id = ida_alloc(&nd_region->dax_ida, GFP_KERNEL);
        if (nd_pfn->id < 0) {
                kfree(nd_dax);
                return NULL;
        }

        dev = &nd_pfn->dev;
        dev_set_name(dev, "dax%d.%d", nd_region->id, nd_pfn->id);
        dev->type = &nd_dax_device_type;
        dev->parent = &nd_region->dev;

        return nd_dax;
}

struct device *nd_dax_create(struct nd_region *nd_region)
{
        struct device *dev = NULL;
        struct nd_dax *nd_dax;

        if (!is_memory(&nd_region->dev))
                return NULL;

        nd_dax = nd_dax_alloc(nd_region);
        if (nd_dax)
                dev = nd_pfn_devinit(&nd_dax->nd_pfn, NULL);
        nd_device_register(dev);
        return dev;
}

int nd_dax_probe(struct device *dev, struct nd_namespace_common *ndns)
{
        int rc;
        struct nd_dax *nd_dax;
        struct device *dax_dev;
        struct nd_pfn *nd_pfn;
        struct nd_pfn_sb *pfn_sb;
        struct nd_region *nd_region = to_nd_region(ndns->dev.parent);

        if (ndns->force_raw)
                return -ENODEV;

        switch (ndns->claim_class) {
        case NVDIMM_CCLASS_NONE:
        case NVDIMM_CCLASS_DAX:
                break;
        default:
                return -ENODEV;
        }

        scoped_guard(nvdimm_bus, &ndns->dev) {
                nd_dax = nd_dax_alloc(nd_region);
                dax_dev = nd_dax_devinit(nd_dax, ndns);
                if (!dax_dev)
                        return -ENOMEM;
        }
        pfn_sb = devm_kmalloc(dev, sizeof(*pfn_sb), GFP_KERNEL);
        nd_pfn = &nd_dax->nd_pfn;
        nd_pfn->pfn_sb = pfn_sb;
        rc = nd_pfn_validate(nd_pfn, DAX_SIG);
        dev_dbg(dev, "dax: %s\n", rc == 0 ? dev_name(dax_dev) : "<none>");
        if (rc < 0) {
                nd_detach_ndns(dax_dev, &nd_pfn->ndns);
                put_device(dax_dev);
        } else
                nd_device_register(dax_dev);

        return rc;
}
EXPORT_SYMBOL(nd_dax_probe);