1 /* 2 * Copyright(c) 2013-2015 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/cpumask.h> 14 #include <linux/module.h> 15 #include <linux/device.h> 16 #include <linux/nd.h> 17 #include "nd.h" 18 19 static int nd_region_probe(struct device *dev) 20 { 21 int err, rc; 22 static unsigned long once; 23 struct nd_region_namespaces *num_ns; 24 struct nd_region *nd_region = to_nd_region(dev); 25 26 if (nd_region->num_lanes > num_online_cpus() 27 && nd_region->num_lanes < num_possible_cpus() 28 && !test_and_set_bit(0, &once)) { 29 dev_info(dev, "online cpus (%d) < concurrent i/o lanes (%d) < possible cpus (%d)\n", 30 num_online_cpus(), nd_region->num_lanes, 31 num_possible_cpus()); 32 dev_info(dev, "setting nr_cpus=%d may yield better libnvdimm device performance\n", 33 nd_region->num_lanes); 34 } 35 36 rc = nd_blk_region_init(nd_region); 37 if (rc) 38 return rc; 39 40 rc = nd_region_register_namespaces(nd_region, &err); 41 num_ns = devm_kzalloc(dev, sizeof(*num_ns), GFP_KERNEL); 42 if (!num_ns) 43 return -ENOMEM; 44 45 if (rc < 0) 46 return rc; 47 48 num_ns->active = rc; 49 num_ns->count = rc + err; 50 dev_set_drvdata(dev, num_ns); 51 52 if (rc && err && rc == err) 53 return -ENODEV; 54 55 nd_region->btt_seed = nd_btt_create(nd_region); 56 nd_region->pfn_seed = nd_pfn_create(nd_region); 57 if (err == 0) 58 return 0; 59 60 /* 61 * Given multiple namespaces per region, we do not want to 62 * disable all the successfully registered peer namespaces upon 63 * a single registration failure. If userspace is missing a 64 * namespace that it expects it can disable/re-enable the region 65 * to retry discovery after correcting the failure. 66 * <regionX>/namespaces returns the current 67 * "<async-registered>/<total>" namespace count. 68 */ 69 dev_err(dev, "failed to register %d namespace%s, continuing...\n", 70 err, err == 1 ? "" : "s"); 71 return 0; 72 } 73 74 static int child_unregister(struct device *dev, void *data) 75 { 76 nd_device_unregister(dev, ND_SYNC); 77 return 0; 78 } 79 80 static int nd_region_remove(struct device *dev) 81 { 82 struct nd_region *nd_region = to_nd_region(dev); 83 84 /* flush attribute readers and disable */ 85 nvdimm_bus_lock(dev); 86 nd_region->ns_seed = NULL; 87 nd_region->btt_seed = NULL; 88 nd_region->pfn_seed = NULL; 89 dev_set_drvdata(dev, NULL); 90 nvdimm_bus_unlock(dev); 91 92 device_for_each_child(dev, NULL, child_unregister); 93 return 0; 94 } 95 96 static int child_notify(struct device *dev, void *data) 97 { 98 nd_device_notify(dev, *(enum nvdimm_event *) data); 99 return 0; 100 } 101 102 static void nd_region_notify(struct device *dev, enum nvdimm_event event) 103 { 104 device_for_each_child(dev, &event, child_notify); 105 } 106 107 static struct nd_device_driver nd_region_driver = { 108 .probe = nd_region_probe, 109 .remove = nd_region_remove, 110 .notify = nd_region_notify, 111 .drv = { 112 .name = "nd_region", 113 }, 114 .type = ND_DRIVER_REGION_BLK | ND_DRIVER_REGION_PMEM, 115 }; 116 117 int __init nd_region_init(void) 118 { 119 return nd_driver_register(&nd_region_driver); 120 } 121 122 void nd_region_exit(void) 123 { 124 driver_unregister(&nd_region_driver.drv); 125 } 126 127 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_PMEM); 128 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_BLK); 129