1// SPDX-License-Identifier: GPL-2.0
  2/* Copyright(c) 2016 - 2018 Intel Corporation. All rights reserved. */
  3#include <linux/memremap.h>
  4#include <linux/module.h>
  5#include <linux/pfn_t.h>
  6#include "../nvdimm/pfn.h"
  7#include "../nvdimm/nd.h"
  8#include "bus.h"
  9
 10static struct dev_dax *__dax_pmem_probe(struct device *dev)
 11{
 12	struct range range;
 13	int rc, id, region_id;
 14	resource_size_t offset;
 15	struct nd_pfn_sb *pfn_sb;
 16	struct dev_dax *dev_dax;
 17	struct dev_dax_data data;
 18	struct nd_namespace_io *nsio;
 19	struct dax_region *dax_region;
 20	struct dev_pagemap pgmap = { };
 21	struct nd_namespace_common *ndns;
 22	struct nd_dax *nd_dax = to_nd_dax(dev);
 23	struct nd_pfn *nd_pfn = &nd_dax->nd_pfn;
 24	struct nd_region *nd_region = to_nd_region(dev->parent);
 25
 26	ndns = nvdimm_namespace_common_probe(dev);
 27	if (IS_ERR(ndns))
 28		return ERR_CAST(ndns);
 29
 30	/* parse the 'pfn' info block via ->rw_bytes */
 31	rc = devm_namespace_enable(dev, ndns, nd_info_block_reserve());
 32	if (rc)
 33		return ERR_PTR(rc);
 34	rc = nvdimm_setup_pfn(nd_pfn, &pgmap);
 35	if (rc)
 36		return ERR_PTR(rc);
 37	devm_namespace_disable(dev, ndns);
 38
 39	/* reserve the metadata area, device-dax will reserve the data */
 40	pfn_sb = nd_pfn->pfn_sb;
 41	offset = le64_to_cpu(pfn_sb->dataoff);
 42	nsio = to_nd_namespace_io(&ndns->dev);
 43	if (!devm_request_mem_region(dev, nsio->res.start, offset,
 44				dev_name(&ndns->dev))) {
 45		dev_warn(dev, "could not reserve metadata\n");
 46		return ERR_PTR(-EBUSY);
 47	}
 48
 49	rc = sscanf(dev_name(&ndns->dev), "namespace%d.%d", &region_id, &id);
 50	if (rc != 2)
 51		return ERR_PTR(-EINVAL);
 52
 53	/* adjust the dax_region range to the start of data */
 54	range = pgmap.range;
 55	range.start += offset;
 56	dax_region = alloc_dax_region(dev, region_id, &range,
 57			nd_region->target_node, le32_to_cpu(pfn_sb->align),
 58			IORESOURCE_DAX_STATIC);
 59	if (!dax_region)
 60		return ERR_PTR(-ENOMEM);
 61
 62	data = (struct dev_dax_data) {
 63		.dax_region = dax_region,
 64		.id = id,
 65		.pgmap = &pgmap,
 66		.size = range_len(&range),
 67	};
 68	dev_dax = devm_create_dev_dax(&data);
 69
 70	/* child dev_dax instances now own the lifetime of the dax_region */
 71	dax_region_put(dax_region);
 72
 73	return dev_dax;
 74}
 75
 76static int dax_pmem_probe(struct device *dev)
 77{
 78	return PTR_ERR_OR_ZERO(__dax_pmem_probe(dev));
 79}
 80
 81static struct nd_device_driver dax_pmem_driver = {
 82	.probe = dax_pmem_probe,
 83	.drv = {
 84		.name = "dax_pmem",
 85	},
 86	.type = ND_DRIVER_DAX_PMEM,
 87};
 88
 89static int __init dax_pmem_init(void)
 90{
 91	return nd_driver_register(&dax_pmem_driver);
 92}
 93module_init(dax_pmem_init);
 94
 95static void __exit dax_pmem_exit(void)
 96{
 97	driver_unregister(&dax_pmem_driver.drv);
 98}
 99module_exit(dax_pmem_exit);
100
101MODULE_LICENSE("GPL v2");
102MODULE_AUTHOR("Intel Corporation");
103MODULE_ALIAS_ND_DEVICE(ND_DEVICE_DAX_PMEM);