drivers/nvdimm/btt_devs.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/blkdev.h>
  14 #include <linux/device.h>
  15 #include <linux/genhd.h>
  16 #include <linux/sizes.h>
  17 #include <linux/slab.h>
  18 #include <linux/fs.h>
  19 #include <linux/mm.h>
  20 #include "nd-core.h"
  21 #include "btt.h"
  22 #include "nd.h"
  23
  24 static void nd_btt_release(struct device *dev)
  25 {
  26         struct nd_region *nd_region = to_nd_region(dev->parent);
  27         struct nd_btt *nd_btt = to_nd_btt(dev);
  28
  29         dev_dbg(dev, "%s\n", __func__);
  30         nd_detach_ndns(&nd_btt->dev, &nd_btt->ndns);
  31         ida_simple_remove(&nd_region->btt_ida, nd_btt->id);
  32         kfree(nd_btt->uuid);
  33         kfree(nd_btt);
  34 }
  35
  36 static struct device_type nd_btt_device_type = {
  37         .name = "nd_btt",
  38         .release = nd_btt_release,
  39 };
  40
  41 bool is_nd_btt(struct device *dev)
  42 {
  43         return dev->type == &nd_btt_device_type;
  44 }
  45 EXPORT_SYMBOL(is_nd_btt);
  46
  47 struct nd_btt *to_nd_btt(struct device *dev)
  48 {
  49         struct nd_btt *nd_btt = container_of(dev, struct nd_btt, dev);
  50
  51         WARN_ON(!is_nd_btt(dev));
  52         return nd_btt;
  53 }
  54 EXPORT_SYMBOL(to_nd_btt);
  55
  56 static const unsigned long btt_lbasize_supported[] = { 512, 520, 528,
  57         4096, 4104, 4160, 4224, 0 };
  58
  59 static ssize_t sector_size_show(struct device *dev,
  60                 struct device_attribute *attr, char *buf)
  61 {
  62         struct nd_btt *nd_btt = to_nd_btt(dev);
  63
  64         return nd_sector_size_show(nd_btt->lbasize, btt_lbasize_supported, buf);
  65 }
  66
  67 static ssize_t sector_size_store(struct device *dev,
  68                 struct device_attribute *attr, const char *buf, size_t len)
  69 {
  70         struct nd_btt *nd_btt = to_nd_btt(dev);
  71         ssize_t rc;
  72
  73         device_lock(dev);
  74         nvdimm_bus_lock(dev);
  75         rc = nd_sector_size_store(dev, buf, &nd_btt->lbasize,
  76                         btt_lbasize_supported);
  77         dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
  78                         rc, buf, buf[len - 1] == '\n' ? "" : "\n");
  79         nvdimm_bus_unlock(dev);
  80         device_unlock(dev);
  81
  82         return rc ? rc : len;
  83 }
  84 static DEVICE_ATTR_RW(sector_size);
  85
  86 static ssize_t uuid_show(struct device *dev,
  87                 struct device_attribute *attr, char *buf)
  88 {
  89         struct nd_btt *nd_btt = to_nd_btt(dev);
  90
  91         if (nd_btt->uuid)
  92                 return sprintf(buf, "%pUb\n", nd_btt->uuid);
  93         return sprintf(buf, "\n");
  94 }
  95
  96 static ssize_t uuid_store(struct device *dev,
  97                 struct device_attribute *attr, const char *buf, size_t len)
  98 {
  99         struct nd_btt *nd_btt = to_nd_btt(dev);
 100         ssize_t rc;
 101
 102         device_lock(dev);
 103         rc = nd_uuid_store(dev, &nd_btt->uuid, buf, len);
 104         dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
 105                         rc, buf, buf[len - 1] == '\n' ? "" : "\n");
 106         device_unlock(dev);
 107
 108         return rc ? rc : len;
 109 }
 110 static DEVICE_ATTR_RW(uuid);
 111
 112 static ssize_t namespace_show(struct device *dev,
 113                 struct device_attribute *attr, char *buf)
 114 {
 115         struct nd_btt *nd_btt = to_nd_btt(dev);
 116         ssize_t rc;
 117
 118         nvdimm_bus_lock(dev);
 119         rc = sprintf(buf, "%s\n", nd_btt->ndns
 120                         ? dev_name(&nd_btt->ndns->dev) : "");
 121         nvdimm_bus_unlock(dev);
 122         return rc;
 123 }
 124
 125 static ssize_t namespace_store(struct device *dev,
 126                 struct device_attribute *attr, const char *buf, size_t len)
 127 {
 128         struct nd_btt *nd_btt = to_nd_btt(dev);
 129         ssize_t rc;
 130
 131         device_lock(dev);
 132         nvdimm_bus_lock(dev);
 133         rc = nd_namespace_store(dev, &nd_btt->ndns, buf, len);
 134         dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
 135                         rc, buf, buf[len - 1] == '\n' ? "" : "\n");
 136         nvdimm_bus_unlock(dev);
 137         device_unlock(dev);
 138
 139         return rc;
 140 }
 141 static DEVICE_ATTR_RW(namespace);
 142
 143 static ssize_t size_show(struct device *dev,
 144                 struct device_attribute *attr, char *buf)
 145 {
 146         struct nd_btt *nd_btt = to_nd_btt(dev);
 147         ssize_t rc;
 148
 149         device_lock(dev);
 150         if (dev->driver)
 151                 rc = sprintf(buf, "%llu\n", nd_btt->size);
 152         else {
 153                 /* no size to convey if the btt instance is disabled */
 154                 rc = -ENXIO;
 155         }
 156         device_unlock(dev);
 157
 158         return rc;
 159 }
 160 static DEVICE_ATTR_RO(size);
 161
 162 static struct attribute *nd_btt_attributes[] = {
 163         &dev_attr_sector_size.attr,
 164         &dev_attr_namespace.attr,
 165         &dev_attr_uuid.attr,
 166         &dev_attr_size.attr,
 167         NULL,
 168 };
 169
 170 static struct attribute_group nd_btt_attribute_group = {
 171         .attrs = nd_btt_attributes,
 172 };
 173
 174 static const struct attribute_group *nd_btt_attribute_groups[] = {
 175         &nd_btt_attribute_group,
 176         &nd_device_attribute_group,
 177         &nd_numa_attribute_group,
 178         NULL,
 179 };
 180
 181 static struct device *__nd_btt_create(struct nd_region *nd_region,
 182                 unsigned long lbasize, u8 *uuid,
 183                 struct nd_namespace_common *ndns)
 184 {
 185         struct nd_btt *nd_btt;
 186         struct device *dev;
 187
 188         nd_btt = kzalloc(sizeof(*nd_btt), GFP_KERNEL);
 189         if (!nd_btt)
 190                 return NULL;
 191
 192         nd_btt->id = ida_simple_get(&nd_region->btt_ida, 0, 0, GFP_KERNEL);
 193         if (nd_btt->id < 0) {
 194                 kfree(nd_btt);
 195                 return NULL;
 196         }
 197
 198         nd_btt->lbasize = lbasize;
 199         if (uuid)
 200                 uuid = kmemdup(uuid, 16, GFP_KERNEL);
 201         nd_btt->uuid = uuid;
 202         dev = &nd_btt->dev;
 203         dev_set_name(dev, "btt%d.%d", nd_region->id, nd_btt->id);
 204         dev->parent = &nd_region->dev;
 205         dev->type = &nd_btt_device_type;
 206         dev->groups = nd_btt_attribute_groups;
 207         device_initialize(&nd_btt->dev);
 208         if (ndns && !__nd_attach_ndns(&nd_btt->dev, ndns, &nd_btt->ndns)) {
 209                 dev_dbg(&ndns->dev, "%s failed, already claimed by %s\n",
 210                                 __func__, dev_name(ndns->claim));
 211                 put_device(dev);
 212                 return NULL;
 213         }
 214         return dev;
 215 }
 216
 217 struct device *nd_btt_create(struct nd_region *nd_region)
 218 {
 219         struct device *dev = __nd_btt_create(nd_region, 0, NULL, NULL);
 220
 221         __nd_device_register(dev);
 222         return dev;
 223 }
 224
 225 static bool uuid_is_null(u8 *uuid)
 226 {
 227         static const u8 null_uuid[16];
 228
 229         return (memcmp(uuid, null_uuid, 16) == 0);
 230 }
 231
 232 /**
 233  * nd_btt_arena_is_valid - check if the metadata layout is valid
 234  * @nd_btt:     device with BTT geometry and backing device info
 235  * @super:      pointer to the arena's info block being tested
 236  *
 237  * Check consistency of the btt info block with itself by validating
 238  * the checksum, and with the parent namespace by verifying the
 239  * parent_uuid contained in the info block with the one supplied in.
 240  *
 241  * Returns:
 242  * false for an invalid info block, true for a valid one
 243  */
 244 bool nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super)
 245 {
 246         const u8 *parent_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev);
 247         u64 checksum;
 248
 249         if (memcmp(super->signature, BTT_SIG, BTT_SIG_LEN) != 0)
 250                 return false;
 251
 252         if (!uuid_is_null(super->parent_uuid))
 253                 if (memcmp(super->parent_uuid, parent_uuid, 16) != 0)
 254                         return false;
 255
 256         checksum = le64_to_cpu(super->checksum);
 257         super->checksum = 0;
 258         if (checksum != nd_sb_checksum((struct nd_gen_sb *) super))
 259                 return false;
 260         super->checksum = cpu_to_le64(checksum);
 261
 262         /* TODO: figure out action for this */
 263         if ((le32_to_cpu(super->flags) & IB_FLAG_ERROR_MASK) != 0)
 264                 dev_info(&nd_btt->dev, "Found arena with an error flag\n");
 265
 266         return true;
 267 }
 268 EXPORT_SYMBOL(nd_btt_arena_is_valid);
 269
 270 static int __nd_btt_probe(struct nd_btt *nd_btt,
 271                 struct nd_namespace_common *ndns, struct btt_sb *btt_sb)
 272 {
 273         if (!btt_sb || !ndns || !nd_btt)
 274                 return -ENODEV;
 275
 276         if (nvdimm_read_bytes(ndns, SZ_4K, btt_sb, sizeof(*btt_sb), 0))
 277                 return -ENXIO;
 278
 279         if (nvdimm_namespace_capacity(ndns) < SZ_16M)
 280                 return -ENXIO;
 281
 282         if (!nd_btt_arena_is_valid(nd_btt, btt_sb))
 283                 return -ENODEV;
 284
 285         nd_btt->lbasize = le32_to_cpu(btt_sb->external_lbasize);
 286         nd_btt->uuid = kmemdup(btt_sb->uuid, 16, GFP_KERNEL);
 287         if (!nd_btt->uuid)
 288                 return -ENOMEM;
 289
 290         __nd_device_register(&nd_btt->dev);
 291
 292         return 0;
 293 }
 294
 295 int nd_btt_probe(struct device *dev, struct nd_namespace_common *ndns)
 296 {
 297         int rc;
 298         struct device *btt_dev;
 299         struct btt_sb *btt_sb;
 300         struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
 301
 302         if (ndns->force_raw)
 303                 return -ENODEV;
 304
 305         nvdimm_bus_lock(&ndns->dev);
 306         btt_dev = __nd_btt_create(nd_region, 0, NULL, ndns);
 307         nvdimm_bus_unlock(&ndns->dev);
 308         if (!btt_dev)
 309                 return -ENOMEM;
 310         btt_sb = devm_kzalloc(dev, sizeof(*btt_sb), GFP_KERNEL);
 311         rc = __nd_btt_probe(to_nd_btt(btt_dev), ndns, btt_sb);
 312         dev_dbg(dev, "%s: btt: %s\n", __func__,
 313                         rc == 0 ? dev_name(btt_dev) : "<none>");
 314         if (rc < 0) {
 315                 struct nd_btt *nd_btt = to_nd_btt(btt_dev);
 316
 317                 nd_detach_ndns(btt_dev, &nd_btt->ndns);
 318                 put_device(btt_dev);
 319         }
 320
 321         return rc;
 322 }
 323 EXPORT_SYMBOL(nd_btt_probe);