diff options
Diffstat (limited to 'drivers/dax/pmem.c')
| -rw-r--r-- | drivers/dax/pmem.c | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/drivers/dax/pmem.c b/drivers/dax/pmem.c new file mode 100644 index 000000000000..f050ea78bb83 --- /dev/null +++ b/drivers/dax/pmem.c @@ -0,0 +1,103 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright(c) 2016 - 2018 Intel Corporation. All rights reserved. */ +#include <linux/memremap.h> +#include <linux/module.h> +#include <linux/pfn_t.h> +#include "../nvdimm/pfn.h" +#include "../nvdimm/nd.h" +#include "bus.h" + +static struct dev_dax *__dax_pmem_probe(struct device *dev) +{ + struct range range; + int rc, id, region_id; + resource_size_t offset; + struct nd_pfn_sb *pfn_sb; + struct dev_dax *dev_dax; + struct dev_dax_data data; + struct nd_namespace_io *nsio; + struct dax_region *dax_region; + struct dev_pagemap pgmap = { }; + struct nd_namespace_common *ndns; + struct nd_dax *nd_dax = to_nd_dax(dev); + struct nd_pfn *nd_pfn = &nd_dax->nd_pfn; + struct nd_region *nd_region = to_nd_region(dev->parent); + + ndns = nvdimm_namespace_common_probe(dev); + if (IS_ERR(ndns)) + return ERR_CAST(ndns); + + /* parse the 'pfn' info block via ->rw_bytes */ + rc = devm_namespace_enable(dev, ndns, nd_info_block_reserve()); + if (rc) + return ERR_PTR(rc); + rc = nvdimm_setup_pfn(nd_pfn, &pgmap); + if (rc) + return ERR_PTR(rc); + devm_namespace_disable(dev, ndns); + + /* reserve the metadata area, device-dax will reserve the data */ + pfn_sb = nd_pfn->pfn_sb; + offset = le64_to_cpu(pfn_sb->dataoff); + nsio = to_nd_namespace_io(&ndns->dev); + if (!devm_request_mem_region(dev, nsio->res.start, offset, + dev_name(&ndns->dev))) { + dev_warn(dev, "could not reserve metadata\n"); + return ERR_PTR(-EBUSY); + } + + rc = sscanf(dev_name(&ndns->dev), "namespace%d.%d", ®ion_id, &id); + if (rc != 2) + return ERR_PTR(-EINVAL); + + /* adjust the dax_region range to the start of data */ + range = pgmap.range; + range.start += offset; + dax_region = alloc_dax_region(dev, region_id, &range, + nd_region->target_node, le32_to_cpu(pfn_sb->align), + IORESOURCE_DAX_STATIC); + if (!dax_region) + return ERR_PTR(-ENOMEM); + + data = (struct dev_dax_data) { + .dax_region = dax_region, + .id = id, + .pgmap = &pgmap, + .size = range_len(&range), + }; + dev_dax = devm_create_dev_dax(&data); + + /* child dev_dax instances now own the lifetime of the dax_region */ + dax_region_put(dax_region); + + return dev_dax; +} + +static int dax_pmem_probe(struct device *dev) +{ + return PTR_ERR_OR_ZERO(__dax_pmem_probe(dev)); +} + +static struct nd_device_driver dax_pmem_driver = { + .probe = dax_pmem_probe, + .drv = { + .name = "dax_pmem", + }, + .type = ND_DRIVER_DAX_PMEM, +}; + +static int __init dax_pmem_init(void) +{ + return nd_driver_register(&dax_pmem_driver); +} +module_init(dax_pmem_init); + +static void __exit dax_pmem_exit(void) +{ + driver_unregister(&dax_pmem_driver.drv); +} +module_exit(dax_pmem_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Intel Corporation"); +MODULE_ALIAS_ND_DEVICE(ND_DEVICE_DAX_PMEM); |