2 * Copyright(c) 2016 Intel Corporation. All rights reserved.
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of version 2 of the GNU General Public License as
6 * published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 #include <linux/percpu-refcount.h>
14 #include <linux/memremap.h>
15 #include <linux/module.h>
16 #include <linux/pfn_t.h>
17 #include "../nvdimm/pfn.h"
18 #include "../nvdimm/nd.h"
23 struct percpu_ref ref;
24 struct completion cmp;
27 static struct dax_pmem *to_dax_pmem(struct percpu_ref *ref)
29 return container_of(ref, struct dax_pmem, ref);
32 static void dax_pmem_percpu_release(struct percpu_ref *ref)
34 struct dax_pmem *dax_pmem = to_dax_pmem(ref);
36 dev_dbg(dax_pmem->dev, "%s\n", __func__);
37 complete(&dax_pmem->cmp);
40 static void dax_pmem_percpu_exit(void *data)
42 struct percpu_ref *ref = data;
43 struct dax_pmem *dax_pmem = to_dax_pmem(ref);
45 dev_dbg(dax_pmem->dev, "%s\n", __func__);
47 wait_for_completion(&dax_pmem->cmp);
50 static void dax_pmem_percpu_kill(void *data)
52 struct percpu_ref *ref = data;
53 struct dax_pmem *dax_pmem = to_dax_pmem(ref);
55 dev_dbg(dax_pmem->dev, "%s\n", __func__);
59 static int dax_pmem_probe(struct device *dev)
64 struct dax_dev *dax_dev;
65 struct nd_pfn_sb *pfn_sb;
66 struct dax_pmem *dax_pmem;
67 struct nd_region *nd_region;
68 struct nd_namespace_io *nsio;
69 struct dax_region *dax_region;
70 struct nd_namespace_common *ndns;
71 struct nd_dax *nd_dax = to_nd_dax(dev);
72 struct nd_pfn *nd_pfn = &nd_dax->nd_pfn;
73 struct vmem_altmap __altmap, *altmap = NULL;
75 ndns = nvdimm_namespace_common_probe(dev);
78 nsio = to_nd_namespace_io(&ndns->dev);
80 /* parse the 'pfn' info block via ->rw_bytes */
81 devm_nsio_enable(dev, nsio);
82 altmap = nvdimm_setup_pfn(nd_pfn, &res, &__altmap);
84 return PTR_ERR(altmap);
85 devm_nsio_disable(dev, nsio);
87 pfn_sb = nd_pfn->pfn_sb;
89 if (!devm_request_mem_region(dev, nsio->res.start,
90 resource_size(&nsio->res), dev_name(dev))) {
91 dev_warn(dev, "could not reserve region %pR\n", &nsio->res);
95 dax_pmem = devm_kzalloc(dev, sizeof(*dax_pmem), GFP_KERNEL);
100 init_completion(&dax_pmem->cmp);
101 rc = percpu_ref_init(&dax_pmem->ref, dax_pmem_percpu_release, 0,
106 rc = devm_add_action_or_reset(dev, dax_pmem_percpu_exit,
111 addr = devm_memremap_pages(dev, &res, &dax_pmem->ref, altmap);
113 return PTR_ERR(addr);
115 rc = devm_add_action_or_reset(dev, dax_pmem_percpu_kill,
120 /* adjust the dax_region resource to the start of data */
121 res.start += le64_to_cpu(pfn_sb->dataoff);
123 nd_region = to_nd_region(dev->parent);
124 dax_region = alloc_dax_region(dev, nd_region->id, &res,
125 le32_to_cpu(pfn_sb->align), addr, PFN_DEV|PFN_MAP);
129 /* TODO: support for subdividing a dax region... */
130 dax_dev = devm_create_dax_dev(dax_region, &res, 1);
132 /* child dax_dev instances now own the lifetime of the dax_region */
133 dax_region_put(dax_region);
135 return PTR_ERR_OR_ZERO(dax_dev);
138 static struct nd_device_driver dax_pmem_driver = {
139 .probe = dax_pmem_probe,
143 .type = ND_DRIVER_DAX_PMEM,
146 static int __init dax_pmem_init(void)
148 return nd_driver_register(&dax_pmem_driver);
150 module_init(dax_pmem_init);
152 static void __exit dax_pmem_exit(void)
154 driver_unregister(&dax_pmem_driver.drv);
156 module_exit(dax_pmem_exit);
158 MODULE_LICENSE("GPL v2");
159 MODULE_AUTHOR("Intel Corporation");
160 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_DAX_PMEM);