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 "dax.h" 20 21 struct dax_pmem { 22 struct device *dev; 23 struct percpu_ref ref; 24 struct completion cmp; 25 }; 26 27 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 percpu_ref_exit(ref); 47 wait_for_completion(&dax_pmem->cmp); 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 dax_pmem *dax_pmem; 66 struct nd_region *nd_region; 67 struct nd_namespace_io *nsio; 68 struct dax_region *dax_region; 69 struct nd_namespace_common *ndns; 70 struct nd_dax *nd_dax = to_nd_dax(dev); 71 struct nd_pfn *nd_pfn = &nd_dax->nd_pfn; 72 struct vmem_altmap __altmap, *altmap = NULL; 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 /* parse the 'pfn' info block via ->rw_bytes */ 80 devm_nsio_enable(dev, nsio); 81 altmap = nvdimm_setup_pfn(nd_pfn, &res, &__altmap); 82 if (IS_ERR(altmap)) 83 return PTR_ERR(altmap); 84 devm_nsio_disable(dev, nsio); 85 86 pfn_sb = nd_pfn->pfn_sb; 87 88 if (!devm_request_mem_region(dev, nsio->res.start, 89 resource_size(&nsio->res), dev_name(dev))) { 90 dev_warn(dev, "could not reserve region %pR\n", &nsio->res); 91 return -EBUSY; 92 } 93 94 dax_pmem = devm_kzalloc(dev, sizeof(*dax_pmem), GFP_KERNEL); 95 if (!dax_pmem) 96 return -ENOMEM; 97 98 dax_pmem->dev = dev; 99 init_completion(&dax_pmem->cmp); 100 rc = percpu_ref_init(&dax_pmem->ref, dax_pmem_percpu_release, 0, 101 GFP_KERNEL); 102 if (rc) 103 return rc; 104 105 rc = devm_add_action_or_reset(dev, dax_pmem_percpu_exit, 106 &dax_pmem->ref); 107 if (rc) 108 return rc; 109 110 addr = devm_memremap_pages(dev, &res, &dax_pmem->ref, altmap); 111 if (IS_ERR(addr)) 112 return PTR_ERR(addr); 113 114 rc = devm_add_action_or_reset(dev, dax_pmem_percpu_kill, 115 &dax_pmem->ref); 116 if (rc) 117 return rc; 118 119 /* adjust the dax_region resource to the start of data */ 120 res.start += le64_to_cpu(pfn_sb->dataoff); 121 122 nd_region = to_nd_region(dev->parent); 123 dax_region = alloc_dax_region(dev, nd_region->id, &res, 124 le32_to_cpu(pfn_sb->align), addr, PFN_DEV|PFN_MAP); 125 if (!dax_region) 126 return -ENOMEM; 127 128 /* TODO: support for subdividing a dax region... */ 129 rc = devm_create_dax_dev(dax_region, &res, 1); 130 131 /* child dax_dev instances now own the lifetime of the dax_region */ 132 dax_region_put(dax_region); 133 134 return rc; 135 } 136 137 static struct nd_device_driver dax_pmem_driver = { 138 .probe = dax_pmem_probe, 139 .drv = { 140 .name = "dax_pmem", 141 }, 142 .type = ND_DRIVER_DAX_PMEM, 143 }; 144 145 static int __init dax_pmem_init(void) 146 { 147 return nd_driver_register(&dax_pmem_driver); 148 } 149 module_init(dax_pmem_init); 150 151 static void __exit dax_pmem_exit(void) 152 { 153 driver_unregister(&dax_pmem_driver.drv); 154 } 155 module_exit(dax_pmem_exit); 156 157 MODULE_LICENSE("GPL v2"); 158 MODULE_AUTHOR("Intel Corporation"); 159 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_DAX_PMEM); 160