1 /* 2 * Copyright(c) 2016 Intel Corporation. All rights reserved. 3 * 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. 7 * 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. 12 */ 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" 19 #include "device-dax.h" 20 21 struct dax_pmem { 22 struct device *dev; 23 struct percpu_ref ref; 24 struct dev_pagemap pgmap; 25 struct completion cmp; 26 }; 27 28 static struct dax_pmem *to_dax_pmem(struct percpu_ref *ref) 29 { 30 return container_of(ref, struct dax_pmem, ref); 31 } 32 33 static void dax_pmem_percpu_release(struct percpu_ref *ref) 34 { 35 struct dax_pmem *dax_pmem = to_dax_pmem(ref); 36 37 dev_dbg(dax_pmem->dev, "%s\n", __func__); 38 complete(&dax_pmem->cmp); 39 } 40 41 static void dax_pmem_percpu_exit(void *data) 42 { 43 struct percpu_ref *ref = data; 44 struct dax_pmem *dax_pmem = to_dax_pmem(ref); 45 46 dev_dbg(dax_pmem->dev, "%s\n", __func__); 47 wait_for_completion(&dax_pmem->cmp); 48 percpu_ref_exit(ref); 49 } 50 51 static void dax_pmem_percpu_kill(void *data) 52 { 53 struct percpu_ref *ref = data; 54 struct dax_pmem *dax_pmem = to_dax_pmem(ref); 55 56 dev_dbg(dax_pmem->dev, "%s\n", __func__); 57 percpu_ref_kill(ref); 58 } 59 60 static int dax_pmem_probe(struct device *dev) 61 { 62 void *addr; 63 struct resource res; 64 int rc, id, region_id; 65 struct nd_pfn_sb *pfn_sb; 66 struct dev_dax *dev_dax; 67 struct dax_pmem *dax_pmem; 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 74 ndns = nvdimm_namespace_common_probe(dev); 75 if (IS_ERR(ndns)) 76 return PTR_ERR(ndns); 77 nsio = to_nd_namespace_io(&ndns->dev); 78 79 dax_pmem = devm_kzalloc(dev, sizeof(*dax_pmem), GFP_KERNEL); 80 if (!dax_pmem) 81 return -ENOMEM; 82 83 /* parse the 'pfn' info block via ->rw_bytes */ 84 rc = devm_nsio_enable(dev, nsio); 85 if (rc) 86 return rc; 87 rc = nvdimm_setup_pfn(nd_pfn, &dax_pmem->pgmap); 88 if (rc) 89 return rc; 90 devm_nsio_disable(dev, nsio); 91 92 pfn_sb = nd_pfn->pfn_sb; 93 94 if (!devm_request_mem_region(dev, nsio->res.start, 95 resource_size(&nsio->res), 96 dev_name(&ndns->dev))) { 97 dev_warn(dev, "could not reserve region %pR\n", &nsio->res); 98 return -EBUSY; 99 } 100 101 dax_pmem->dev = dev; 102 init_completion(&dax_pmem->cmp); 103 rc = percpu_ref_init(&dax_pmem->ref, dax_pmem_percpu_release, 0, 104 GFP_KERNEL); 105 if (rc) 106 return rc; 107 108 rc = devm_add_action_or_reset(dev, dax_pmem_percpu_exit, 109 &dax_pmem->ref); 110 if (rc) 111 return rc; 112 113 dax_pmem->pgmap.ref = &dax_pmem->ref; 114 addr = devm_memremap_pages(dev, &dax_pmem->pgmap); 115 if (IS_ERR(addr)) 116 return PTR_ERR(addr); 117 118 rc = devm_add_action_or_reset(dev, dax_pmem_percpu_kill, 119 &dax_pmem->ref); 120 if (rc) 121 return rc; 122 123 /* adjust the dax_region resource to the start of data */ 124 memcpy(&res, &dax_pmem->pgmap.res, sizeof(res)); 125 res.start += le64_to_cpu(pfn_sb->dataoff); 126 127 rc = sscanf(dev_name(&ndns->dev), "namespace%d.%d", ®ion_id, &id); 128 if (rc != 2) 129 return -EINVAL; 130 131 dax_region = alloc_dax_region(dev, region_id, &res, 132 le32_to_cpu(pfn_sb->align), addr, PFN_DEV|PFN_MAP); 133 if (!dax_region) 134 return -ENOMEM; 135 136 /* TODO: support for subdividing a dax region... */ 137 dev_dax = devm_create_dev_dax(dax_region, id, &res, 1); 138 139 /* child dev_dax instances now own the lifetime of the dax_region */ 140 dax_region_put(dax_region); 141 142 return PTR_ERR_OR_ZERO(dev_dax); 143 } 144 145 static struct nd_device_driver dax_pmem_driver = { 146 .probe = dax_pmem_probe, 147 .drv = { 148 .name = "dax_pmem", 149 }, 150 .type = ND_DRIVER_DAX_PMEM, 151 }; 152 153 static int __init dax_pmem_init(void) 154 { 155 return nd_driver_register(&dax_pmem_driver); 156 } 157 module_init(dax_pmem_init); 158 159 static void __exit dax_pmem_exit(void) 160 { 161 driver_unregister(&dax_pmem_driver.drv); 162 } 163 module_exit(dax_pmem_exit); 164 165 MODULE_LICENSE("GPL v2"); 166 MODULE_AUTHOR("Intel Corporation"); 167 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_DAX_PMEM); 168