LXR linux/drivers/nvdimm/region.c

   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
  19static int nd_region_probe(struct device *dev)
  20{
  21        int err, rc;
  22        static unsigned long once;
  23        struct nd_region_data *ndrd;
  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_region_activate(nd_region);
  37        if (rc)
  38                return rc;
  39
  40        rc = nd_blk_region_init(nd_region);
  41        if (rc)
  42                return rc;
  43
  44        rc = nd_region_register_namespaces(nd_region, &err);
  45        if (rc < 0)
  46                return rc;
  47
  48        ndrd = dev_get_drvdata(dev);
  49        ndrd->ns_active = rc;
  50        ndrd->ns_count = rc + err;
  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        nd_region->dax_seed = nd_dax_create(nd_region);
  58        if (err == 0)
  59                return 0;
  60
  61        /*
  62         * Given multiple namespaces per region, we do not want to
  63         * disable all the successfully registered peer namespaces upon
  64         * a single registration failure.  If userspace is missing a
  65         * namespace that it expects it can disable/re-enable the region
  66         * to retry discovery after correcting the failure.
  67         * <regionX>/namespaces returns the current
  68         * "<async-registered>/<total>" namespace count.
  69         */
  70        dev_err(dev, "failed to register %d namespace%s, continuing...\n",
  71                        err, err == 1 ? "" : "s");
  72        return 0;
  73}
  74
  75static int child_unregister(struct device *dev, void *data)
  76{
  77        nd_device_unregister(dev, ND_SYNC);
  78        return 0;
  79}
  80
  81static int nd_region_remove(struct device *dev)
  82{
  83        struct nd_region *nd_region = to_nd_region(dev);
  84
  85        device_for_each_child(dev, NULL, child_unregister);
  86
  87        /* flush attribute readers and disable */
  88        nvdimm_bus_lock(dev);
  89        nd_region->ns_seed = NULL;
  90        nd_region->btt_seed = NULL;
  91        nd_region->pfn_seed = NULL;
  92        nd_region->dax_seed = NULL;
  93        dev_set_drvdata(dev, NULL);
  94        nvdimm_bus_unlock(dev);
  95
  96        return 0;
  97}
  98
  99static int child_notify(struct device *dev, void *data)
 100{
 101        nd_device_notify(dev, *(enum nvdimm_event *) data);
 102        return 0;
 103}
 104
 105static void nd_region_notify(struct device *dev, enum nvdimm_event event)
 106{
 107        device_for_each_child(dev, &event, child_notify);
 108}
 109
 110static struct nd_device_driver nd_region_driver = {
 111        .probe = nd_region_probe,
 112        .remove = nd_region_remove,
 113        .notify = nd_region_notify,
 114        .drv = {
 115                .name = "nd_region",
 116        },
 117        .type = ND_DRIVER_REGION_BLK | ND_DRIVER_REGION_PMEM,
 118};
 119
 120int __init nd_region_init(void)
 121{
 122        return nd_driver_register(&nd_region_driver);
 123}
 124
 125void nd_region_exit(void)
 126{
 127        driver_unregister(&nd_region_driver.drv);
 128}
 129
 130MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_PMEM);
 131MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_BLK);
 132