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 if (err == 0) 57 return 0; 58 59 /* 60 * Given multiple namespaces per region, we do not want to 61 * disable all the successfully registered peer namespaces upon 62 * a single registration failure. If userspace is missing a 63 * namespace that it expects it can disable/re-enable the region 64 * to retry discovery after correcting the failure. 65 * <regionX>/namespaces returns the current 66 * "<async-registered>/<total>" namespace count. 67 */ 68 dev_err(dev, "failed to register %d namespace%s, continuing...\n", 69 err, err == 1 ? "" : "s"); 70 return 0; 71 } 72 73 static int child_unregister(struct device *dev, void *data) 74 { 75 nd_device_unregister(dev, ND_SYNC); 76 return 0; 77 } 78 79 static int nd_region_remove(struct device *dev) 80 { 81 struct nd_region *nd_region = to_nd_region(dev); 82 83 /* flush attribute readers and disable */ 84 nvdimm_bus_lock(dev); 85 nd_region->ns_seed = NULL; 86 nd_region->btt_seed = NULL; 87 dev_set_drvdata(dev, NULL); 88 nvdimm_bus_unlock(dev); 89 90 device_for_each_child(dev, NULL, child_unregister); 91 return 0; 92 } 93 94 static struct nd_device_driver nd_region_driver = { 95 .probe = nd_region_probe, 96 .remove = nd_region_remove, 97 .drv = { 98 .name = "nd_region", 99 }, 100 .type = ND_DRIVER_REGION_BLK | ND_DRIVER_REGION_PMEM, 101 }; 102 103 int __init nd_region_init(void) 104 { 105 return nd_driver_register(&nd_region_driver); 106 } 107 108 void nd_region_exit(void) 109 { 110 driver_unregister(&nd_region_driver.drv); 111 } 112 113 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_PMEM); 114 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_BLK); 115