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