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, "trace\n"); 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, "trace\n"); 47 wait_for_completion(&dax_pmem->cmp); 48 percpu_ref_exit(ref); 49 } 50 51 static void dax_pmem_percpu_kill(struct percpu_ref *ref) 52 { 53 struct dax_pmem *dax_pmem = to_dax_pmem(ref); 54 55 dev_dbg(dax_pmem->dev, "trace\n"); 56 percpu_ref_kill(ref); 57 } 58 59 static int dax_pmem_probe(struct device *dev) 60 { 61 void *addr; 62 struct resource res; 63 int rc, id, region_id; 64 struct nd_pfn_sb *pfn_sb; 65 struct dev_dax *dev_dax; 66 struct dax_pmem *dax_pmem; 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 73 ndns = nvdimm_namespace_common_probe(dev); 74 if (IS_ERR(ndns)) 75 return PTR_ERR(ndns); 76 nsio = to_nd_namespace_io(&ndns->dev); 77 78 dax_pmem = devm_kzalloc(dev, sizeof(*dax_pmem), GFP_KERNEL); 79 if (!dax_pmem) 80 return -ENOMEM; 81 82 /* parse the 'pfn' info block via ->rw_bytes */ 83 rc = devm_nsio_enable(dev, nsio); 84 if (rc) 85 return rc; 86 rc = nvdimm_setup_pfn(nd_pfn, &dax_pmem->pgmap); 87 if (rc) 88 return rc; 89 devm_nsio_disable(dev, nsio); 90 91 pfn_sb = nd_pfn->pfn_sb; 92 93 if (!devm_request_mem_region(dev, nsio->res.start, 94 resource_size(&nsio->res), 95 dev_name(&ndns->dev))) { 96 dev_warn(dev, "could not reserve region %pR\n", &nsio->res); 97 return -EBUSY; 98 } 99 100 dax_pmem->dev = dev; 101 init_completion(&dax_pmem->cmp); 102 rc = percpu_ref_init(&dax_pmem->ref, dax_pmem_percpu_release, 0, 103 GFP_KERNEL); 104 if (rc) 105 return rc; 106 107 rc = devm_add_action(dev, dax_pmem_percpu_exit, &dax_pmem->ref); 108 if (rc) { 109 percpu_ref_exit(&dax_pmem->ref); 110 return rc; 111 } 112 113 dax_pmem->pgmap.ref = &dax_pmem->ref; 114 dax_pmem->pgmap.kill = dax_pmem_percpu_kill; 115 addr = devm_memremap_pages(dev, &dax_pmem->pgmap); 116 if (IS_ERR(addr)) 117 return PTR_ERR(addr); 118 119 /* adjust the dax_region resource to the start of data */ 120 memcpy(&res, &dax_pmem->pgmap.res, sizeof(res)); 121 res.start += le64_to_cpu(pfn_sb->dataoff); 122 123 rc = sscanf(dev_name(&ndns->dev), "namespace%d.%d", ®ion_id, &id); 124 if (rc != 2) 125 return -EINVAL; 126 127 dax_region = alloc_dax_region(dev, 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, id, &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 module_nd_driver(dax_pmem_driver); 150 151 MODULE_LICENSE("GPL v2"); 152 MODULE_AUTHOR("Intel Corporation"); 153 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_DAX_PMEM); 154