/*
 * Copyright(c) 2013-2016 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/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, "%s\n", __func__);
	nd_detach_ndns(dev, &nd_pfn->ndns);
	ida_simple_remove(&nd_region->dax_ida, nd_pfn->id);
	kfree(nd_pfn->uuid);
	kfree(nd_dax);
}

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

bool is_nd_dax(struct device *dev)
{
	return dev ? dev->type == &nd_dax_device_type : false;
}
EXPORT_SYMBOL(is_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 attribute_group *nd_dax_attribute_groups[] = {
	&nd_pfn_attribute_group,
	&nd_device_attribute_group,
	&nd_numa_attribute_group,
	NULL,
};

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(sizeof(*nd_dax), GFP_KERNEL);
	if (!nd_dax)
		return NULL;

	nd_pfn = &nd_dax->nd_pfn;
	nd_pfn->id = ida_simple_get(&nd_region->dax_ida, 0, 0, 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->groups = nd_dax_attribute_groups;
	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;
	}

	nvdimm_bus_lock(&ndns->dev);
	nd_dax = nd_dax_alloc(nd_region);
	nd_pfn = &nd_dax->nd_pfn;
	dax_dev = nd_pfn_devinit(nd_pfn, ndns);
	nvdimm_bus_unlock(&ndns->dev);
	if (!dax_dev)
		return -ENOMEM;
	pfn_sb = devm_kzalloc(dev, sizeof(*pfn_sb), GFP_KERNEL);
	nd_pfn->pfn_sb = pfn_sb;
	rc = nd_pfn_validate(nd_pfn, DAX_SIG);
	dev_dbg(dev, "%s: dax: %s\n", __func__,
			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);