1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright(c) 2016 - 2018 Intel Corporation. All rights reserved. */ 3 #include <linux/memremap.h> 4 #include <linux/module.h> 5 #include "../nvdimm/pfn.h" 6 #include "../nvdimm/nd.h" 7 #include "bus.h" 8 9 static struct dev_dax *__dax_pmem_probe(struct device *dev) 10 { 11 struct range range; 12 int rc, id, region_id; 13 resource_size_t offset; 14 struct nd_pfn_sb *pfn_sb; 15 struct dev_dax_data data; 16 struct nd_namespace_io *nsio; 17 struct dax_region *dax_region; 18 struct dev_pagemap pgmap = { }; 19 struct nd_namespace_common *ndns; 20 struct nd_dax *nd_dax = to_nd_dax(dev); 21 struct nd_pfn *nd_pfn = &nd_dax->nd_pfn; 22 struct nd_region *nd_region = to_nd_region(dev->parent); 23 24 ndns = nvdimm_namespace_common_probe(dev); 25 if (IS_ERR(ndns)) 26 return ERR_CAST(ndns); 27 28 /* parse the 'pfn' info block via ->rw_bytes */ 29 rc = devm_namespace_enable(dev, ndns, nd_info_block_reserve()); 30 if (rc) 31 return ERR_PTR(rc); 32 rc = nvdimm_setup_pfn(nd_pfn, &pgmap); 33 if (rc) 34 return ERR_PTR(rc); 35 devm_namespace_disable(dev, ndns); 36 37 /* reserve the metadata area, device-dax will reserve the data */ 38 pfn_sb = nd_pfn->pfn_sb; 39 offset = le64_to_cpu(pfn_sb->dataoff); 40 nsio = to_nd_namespace_io(&ndns->dev); 41 if (!devm_request_mem_region(dev, nsio->res.start, offset, 42 dev_name(&ndns->dev))) { 43 dev_warn(dev, "could not reserve metadata\n"); 44 return ERR_PTR(-EBUSY); 45 } 46 47 rc = sscanf(dev_name(&ndns->dev), "namespace%d.%d", ®ion_id, &id); 48 if (rc != 2) 49 return ERR_PTR(-EINVAL); 50 51 /* adjust the dax_region range to the start of data */ 52 range = pgmap.range; 53 range.start += offset; 54 dax_region = alloc_dax_region(dev, region_id, &range, 55 nd_region->target_node, le32_to_cpu(pfn_sb->align), 56 IORESOURCE_DAX_STATIC); 57 if (!dax_region) 58 return ERR_PTR(-ENOMEM); 59 60 data = (struct dev_dax_data) { 61 .dax_region = dax_region, 62 .id = id, 63 .pgmap = &pgmap, 64 .size = range_len(&range), 65 .memmap_on_memory = false, 66 }; 67 68 return devm_create_dev_dax(&data); 69 } 70 71 static int dax_pmem_probe(struct device *dev) 72 { 73 return PTR_ERR_OR_ZERO(__dax_pmem_probe(dev)); 74 } 75 76 static struct nd_device_driver dax_pmem_driver = { 77 .probe = dax_pmem_probe, 78 .drv = { 79 .name = "dax_pmem", 80 }, 81 .type = ND_DRIVER_DAX_PMEM, 82 }; 83 84 static int __init dax_pmem_init(void) 85 { 86 return nd_driver_register(&dax_pmem_driver); 87 } 88 module_init(dax_pmem_init); 89 90 static void __exit dax_pmem_exit(void) 91 { 92 driver_unregister(&dax_pmem_driver.drv); 93 } 94 module_exit(dax_pmem_exit); 95 96 MODULE_DESCRIPTION("PMEM DAX: direct access to persistent memory"); 97 MODULE_LICENSE("GPL v2"); 98 MODULE_AUTHOR("Intel Corporation"); 99 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_DAX_PMEM); 100