drivers/nvdimm/claim.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
   4  */
   5 #include <linux/device.h>
   6 #include <linux/sizes.h>
   7 #include "nd-core.h"
   8 #include "pmem.h"
   9 #include "pfn.h"
  10 #include "btt.h"
  11 #include "nd.h"
  12
  13 void __nd_detach_ndns(struct device *dev, struct nd_namespace_common **_ndns)
  14 {
  15         struct nd_namespace_common *ndns = *_ndns;
  16         struct nvdimm_bus *nvdimm_bus;
  17
  18         if (!ndns)
  19                 return;
  20
  21         nvdimm_bus = walk_to_nvdimm_bus(&ndns->dev);
  22         lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
  23         dev_WARN_ONCE(dev, ndns->claim != dev, "%s: invalid claim\n", __func__);
  24         ndns->claim = NULL;
  25         *_ndns = NULL;
  26         put_device(&ndns->dev);
  27 }
  28
  29 void nd_detach_ndns(struct device *dev,
  30                 struct nd_namespace_common **_ndns)
  31 {
  32         struct nd_namespace_common *ndns = *_ndns;
  33
  34         if (!ndns)
  35                 return;
  36         get_device(&ndns->dev);
  37         nvdimm_bus_lock(&ndns->dev);
  38         __nd_detach_ndns(dev, _ndns);
  39         nvdimm_bus_unlock(&ndns->dev);
  40         put_device(&ndns->dev);
  41 }
  42
  43 bool __nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach,
  44                 struct nd_namespace_common **_ndns)
  45 {
  46         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&attach->dev);
  47
  48         if (attach->claim)
  49                 return false;
  50         lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
  51         dev_WARN_ONCE(dev, *_ndns, "%s: invalid claim\n", __func__);
  52         attach->claim = dev;
  53         *_ndns = attach;
  54         get_device(&attach->dev);
  55         return true;
  56 }
  57
  58 bool nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach,
  59                 struct nd_namespace_common **_ndns)
  60 {
  61         bool claimed;
  62
  63         nvdimm_bus_lock(&attach->dev);
  64         claimed = __nd_attach_ndns(dev, attach, _ndns);
  65         nvdimm_bus_unlock(&attach->dev);
  66         return claimed;
  67 }
  68
  69 static int namespace_match(struct device *dev, void *data)
  70 {
  71         char *name = data;
  72
  73         return strcmp(name, dev_name(dev)) == 0;
  74 }
  75
  76 static bool is_idle(struct device *dev, struct nd_namespace_common *ndns)
  77 {
  78         struct nd_region *nd_region = to_nd_region(dev->parent);
  79         struct device *seed = NULL;
  80
  81         if (is_nd_btt(dev))
  82                 seed = nd_region->btt_seed;
  83         else if (is_nd_pfn(dev))
  84                 seed = nd_region->pfn_seed;
  85         else if (is_nd_dax(dev))
  86                 seed = nd_region->dax_seed;
  87
  88         if (seed == dev || ndns || dev->driver)
  89                 return false;
  90         return true;
  91 }
  92
  93 struct nd_pfn *to_nd_pfn_safe(struct device *dev)
  94 {
  95         /*
  96          * pfn device attributes are re-used by dax device instances, so we
  97          * need to be careful to correct device-to-nd_pfn conversion.
  98          */
  99         if (is_nd_pfn(dev))
 100                 return to_nd_pfn(dev);
 101
 102         if (is_nd_dax(dev)) {
 103                 struct nd_dax *nd_dax = to_nd_dax(dev);
 104
 105                 return &nd_dax->nd_pfn;
 106         }
 107
 108         WARN_ON(1);
 109         return NULL;
 110 }
 111
 112 static void nd_detach_and_reset(struct device *dev,
 113                 struct nd_namespace_common **_ndns)
 114 {
 115         /* detach the namespace and destroy / reset the device */
 116         __nd_detach_ndns(dev, _ndns);
 117         if (is_idle(dev, *_ndns)) {
 118                 nd_device_unregister(dev, ND_ASYNC);
 119         } else if (is_nd_btt(dev)) {
 120                 struct nd_btt *nd_btt = to_nd_btt(dev);
 121
 122                 nd_btt->lbasize = 0;
 123                 kfree(nd_btt->uuid);
 124                 nd_btt->uuid = NULL;
 125         } else if (is_nd_pfn(dev) || is_nd_dax(dev)) {
 126                 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
 127
 128                 kfree(nd_pfn->uuid);
 129                 nd_pfn->uuid = NULL;
 130                 nd_pfn->mode = PFN_MODE_NONE;
 131         }
 132 }
 133
 134 ssize_t nd_namespace_store(struct device *dev,
 135                 struct nd_namespace_common **_ndns, const char *buf,
 136                 size_t len)
 137 {
 138         struct nd_namespace_common *ndns;
 139         struct device *found;
 140         char *name;
 141
 142         if (dev->driver) {
 143                 dev_dbg(dev, "namespace already active\n");
 144                 return -EBUSY;
 145         }
 146
 147         name = kstrndup(buf, len, GFP_KERNEL);
 148         if (!name)
 149                 return -ENOMEM;
 150         strim(name);
 151
 152         if (strncmp(name, "namespace", 9) == 0 || strcmp(name, "") == 0)
 153                 /* pass */;
 154         else {
 155                 len = -EINVAL;
 156                 goto out;
 157         }
 158
 159         ndns = *_ndns;
 160         if (strcmp(name, "") == 0) {
 161                 nd_detach_and_reset(dev, _ndns);
 162                 goto out;
 163         } else if (ndns) {
 164                 dev_dbg(dev, "namespace already set to: %s\n",
 165                                 dev_name(&ndns->dev));
 166                 len = -EBUSY;
 167                 goto out;
 168         }
 169
 170         found = device_find_child(dev->parent, name, namespace_match);
 171         if (!found) {
 172                 dev_dbg(dev, "'%s' not found under %s\n", name,
 173                                 dev_name(dev->parent));
 174                 len = -ENODEV;
 175                 goto out;
 176         }
 177
 178         ndns = to_ndns(found);
 179
 180         switch (ndns->claim_class) {
 181         case NVDIMM_CCLASS_NONE:
 182                 break;
 183         case NVDIMM_CCLASS_BTT:
 184         case NVDIMM_CCLASS_BTT2:
 185                 if (!is_nd_btt(dev)) {
 186                         len = -EBUSY;
 187                         goto out_attach;
 188                 }
 189                 break;
 190         case NVDIMM_CCLASS_PFN:
 191                 if (!is_nd_pfn(dev)) {
 192                         len = -EBUSY;
 193                         goto out_attach;
 194                 }
 195                 break;
 196         case NVDIMM_CCLASS_DAX:
 197                 if (!is_nd_dax(dev)) {
 198                         len = -EBUSY;
 199                         goto out_attach;
 200                 }
 201                 break;
 202         default:
 203                 len = -EBUSY;
 204                 goto out_attach;
 205                 break;
 206         }
 207
 208         if (__nvdimm_namespace_capacity(ndns) < SZ_16M) {
 209                 dev_dbg(dev, "%s too small to host\n", name);
 210                 len = -ENXIO;
 211                 goto out_attach;
 212         }
 213
 214         WARN_ON_ONCE(!is_nvdimm_bus_locked(dev));
 215         if (!__nd_attach_ndns(dev, ndns, _ndns)) {
 216                 dev_dbg(dev, "%s already claimed\n",
 217                                 dev_name(&ndns->dev));
 218                 len = -EBUSY;
 219         }
 220
 221  out_attach:
 222         put_device(&ndns->dev); /* from device_find_child */
 223  out:
 224         kfree(name);
 225         return len;
 226 }
 227
 228 /*
 229  * nd_sb_checksum: compute checksum for a generic info block
 230  *
 231  * Returns a fletcher64 checksum of everything in the given info block
 232  * except the last field (since that's where the checksum lives).
 233  */
 234 u64 nd_sb_checksum(struct nd_gen_sb *nd_gen_sb)
 235 {
 236         u64 sum;
 237         __le64 sum_save;
 238
 239         BUILD_BUG_ON(sizeof(struct btt_sb) != SZ_4K);
 240         BUILD_BUG_ON(sizeof(struct nd_pfn_sb) != SZ_4K);
 241         BUILD_BUG_ON(sizeof(struct nd_gen_sb) != SZ_4K);
 242
 243         sum_save = nd_gen_sb->checksum;
 244         nd_gen_sb->checksum = 0;
 245         sum = nd_fletcher64(nd_gen_sb, sizeof(*nd_gen_sb), 1);
 246         nd_gen_sb->checksum = sum_save;
 247         return sum;
 248 }
 249 EXPORT_SYMBOL(nd_sb_checksum);
 250
 251 static int nsio_rw_bytes(struct nd_namespace_common *ndns,
 252                 resource_size_t offset, void *buf, size_t size, int rw,
 253                 unsigned long flags)
 254 {
 255         struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
 256         unsigned int sz_align = ALIGN(size + (offset & (512 - 1)), 512);
 257         sector_t sector = offset >> 9;
 258         int rc = 0, ret = 0;
 259
 260         if (unlikely(!size))
 261                 return 0;
 262
 263         if (unlikely(offset + size > nsio->size)) {
 264                 dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
 265                 return -EFAULT;
 266         }
 267
 268         if (rw == READ) {
 269                 if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align)))
 270                         return -EIO;
 271                 if (copy_mc_to_kernel(buf, nsio->addr + offset, size) != 0)
 272                         return -EIO;
 273                 return 0;
 274         }
 275
 276         if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align))) {
 277                 if (IS_ALIGNED(offset, 512) && IS_ALIGNED(size, 512)
 278                                 && !(flags & NVDIMM_IO_ATOMIC)) {
 279                         long cleared;
 280
 281                         might_sleep();
 282                         cleared = nvdimm_clear_poison(&ndns->dev,
 283                                         nsio->res.start + offset, size);
 284                         if (cleared < size)
 285                                 rc = -EIO;
 286                         if (cleared > 0 && cleared / 512) {
 287                                 cleared /= 512;
 288                                 badblocks_clear(&nsio->bb, sector, cleared);
 289                         }
 290                         arch_invalidate_pmem(nsio->addr + offset, size);
 291                 } else
 292                         rc = -EIO;
 293         }
 294
 295         memcpy_flushcache(nsio->addr + offset, buf, size);
 296         ret = nvdimm_flush(to_nd_region(ndns->dev.parent), NULL);
 297         if (ret)
 298                 rc = ret;
 299
 300         return rc;
 301 }
 302
 303 int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio,
 304                 resource_size_t size)
 305 {
 306         struct nd_namespace_common *ndns = &nsio->common;
 307         struct range range = {
 308                 .start = nsio->res.start,
 309                 .end = nsio->res.end,
 310         };
 311
 312         nsio->size = size;
 313         if (!devm_request_mem_region(dev, range.start, size,
 314                                 dev_name(&ndns->dev))) {
 315                 dev_warn(dev, "could not reserve region %pR\n", &nsio->res);
 316                 return -EBUSY;
 317         }
 318
 319         ndns->rw_bytes = nsio_rw_bytes;
 320         if (devm_init_badblocks(dev, &nsio->bb))
 321                 return -ENOMEM;
 322         nvdimm_badblocks_populate(to_nd_region(ndns->dev.parent), &nsio->bb,
 323                         &range);
 324
 325         nsio->addr = devm_memremap(dev, range.start, size, ARCH_MEMREMAP_PMEM);
 326
 327         return PTR_ERR_OR_ZERO(nsio->addr);
 328 }
 329
 330 void devm_nsio_disable(struct device *dev, struct nd_namespace_io *nsio)
 331 {
 332         struct resource *res = &nsio->res;
 333
 334         devm_memunmap(dev, nsio->addr);
 335         devm_exit_badblocks(dev, &nsio->bb);
 336         devm_release_mem_region(dev, res->start, nsio->size);
 337 }