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/module.h>
  14 #include <linux/device.h>
  15 #include <linux/nd.h>
  16 #include "nd.h"
  17
  18 static int nd_region_probe(struct device *dev)
  19 {
  20         int err;
  21         struct nd_region_namespaces *num_ns;
  22         struct nd_region *nd_region = to_nd_region(dev);
  23         int rc = nd_region_register_namespaces(nd_region, &err);
  24
  25         num_ns = devm_kzalloc(dev, sizeof(*num_ns), GFP_KERNEL);
  26         if (!num_ns)
  27                 return -ENOMEM;
  28
  29         if (rc < 0)
  30                 return rc;
  31
  32         num_ns->active = rc;
  33         num_ns->count = rc + err;
  34         dev_set_drvdata(dev, num_ns);
  35
  36         if (rc && err && rc == err)
  37                 return -ENODEV;
  38
  39         nd_region->btt_seed = nd_btt_create(nd_region);
  40         if (err == 0)
  41                 return 0;
  42
  43         /*
  44          * Given multiple namespaces per region, we do not want to
  45          * disable all the successfully registered peer namespaces upon
  46          * a single registration failure.  If userspace is missing a
  47          * namespace that it expects it can disable/re-enable the region
  48          * to retry discovery after correcting the failure.
  49          * <regionX>/namespaces returns the current
  50          * "<async-registered>/<total>" namespace count.
  51          */
  52         dev_err(dev, "failed to register %d namespace%s, continuing...\n",
  53                         err, err == 1 ? "" : "s");
  54         return 0;
  55 }
  56
  57 static int child_unregister(struct device *dev, void *data)
  58 {
  59         nd_device_unregister(dev, ND_SYNC);
  60         return 0;
  61 }
  62
  63 static int nd_region_remove(struct device *dev)
  64 {
  65         struct nd_region *nd_region = to_nd_region(dev);
  66
  67         /* flush attribute readers and disable */
  68         nvdimm_bus_lock(dev);
  69         nd_region->ns_seed = NULL;
  70         nd_region->btt_seed = NULL;
  71         dev_set_drvdata(dev, NULL);
  72         nvdimm_bus_unlock(dev);
  73
  74         device_for_each_child(dev, NULL, child_unregister);
  75         return 0;
  76 }
  77
  78 static struct nd_device_driver nd_region_driver = {
  79         .probe = nd_region_probe,
  80         .remove = nd_region_remove,
  81         .drv = {
  82                 .name = "nd_region",
  83         },
  84         .type = ND_DRIVER_REGION_BLK | ND_DRIVER_REGION_PMEM,
  85 };
  86
  87 int __init nd_region_init(void)
  88 {
  89         return nd_driver_register(&nd_region_driver);
  90 }
  91
  92 void nd_region_exit(void)
  93 {
  94         driver_unregister(&nd_region_driver.drv);
  95 }
  96
  97 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_PMEM);
  98 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_BLK);