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 <linux/badblocks.h>
   8 #include "nd-core.h"
   9 #include "pmem.h"
  10 #include "pfn.h"
  11 #include "btt.h"
  12 #include "nd.h"
  13
  14 void __nd_detach_ndns(struct device *dev, struct nd_namespace_common **_ndns)
  15 {
  16         struct nd_namespace_common *ndns = *_ndns;
  17         struct nvdimm_bus *nvdimm_bus;
  18
  19         if (!ndns)
  20                 return;
  21
  22         nvdimm_bus = walk_to_nvdimm_bus(&ndns->dev);
  23         lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
  24         dev_WARN_ONCE(dev, ndns->claim != dev, "%s: invalid claim\n", __func__);
  25         ndns->claim = NULL;
  26         *_ndns = NULL;
  27         put_device(&ndns->dev);
  28 }
  29
  30 void nd_detach_ndns(struct device *dev,
  31                 struct nd_namespace_common **_ndns)
  32 {
  33         struct nd_namespace_common *ndns = *_ndns;
  34
  35         if (!ndns)
  36                 return;
  37         get_device(&ndns->dev);
  38         nvdimm_bus_lock(&ndns->dev);
  39         __nd_detach_ndns(dev, _ndns);
  40         nvdimm_bus_unlock(&ndns->dev);
  41         put_device(&ndns->dev);
  42 }
  43
  44 bool __nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach,
  45                 struct nd_namespace_common **_ndns)
  46 {
  47         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&attach->dev);
  48
  49         if (attach->claim)
  50                 return false;
  51         lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
  52         dev_WARN_ONCE(dev, *_ndns, "%s: invalid claim\n", __func__);
  53         attach->claim = dev;
  54         *_ndns = attach;
  55         get_device(&attach->dev);
  56         return true;
  57 }
  58
  59 bool nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach,
  60                 struct nd_namespace_common **_ndns)
  61 {
  62         bool claimed;
  63
  64         nvdimm_bus_lock(&attach->dev);
  65         claimed = __nd_attach_ndns(dev, attach, _ndns);
  66         nvdimm_bus_unlock(&attach->dev);
  67         return claimed;
  68 }
  69
  70 static int namespace_match(struct device *dev, void *data)
  71 {
  72         char *name = data;
  73
  74         return strcmp(name, dev_name(dev)) == 0;
  75 }
  76
  77 static bool is_idle(struct device *dev, struct nd_namespace_common *ndns)
  78 {
  79         struct nd_region *nd_region = to_nd_region(dev->parent);
  80         struct device *seed = NULL;
  81
  82         if (is_nd_btt(dev))
  83                 seed = nd_region->btt_seed;
  84         else if (is_nd_pfn(dev))
  85                 seed = nd_region->pfn_seed;
  86         else if (is_nd_dax(dev))
  87                 seed = nd_region->dax_seed;
  88
  89         if (seed == dev || ndns || dev->driver)
  90                 return false;
  91         return true;
  92 }
  93
  94 struct nd_pfn *to_nd_pfn_safe(struct device *dev)
  95 {
  96         /*
  97          * pfn device attributes are re-used by dax device instances, so we
  98          * need to be careful to correct device-to-nd_pfn conversion.
  99          */
 100         if (is_nd_pfn(dev))
 101                 return to_nd_pfn(dev);
 102
 103         if (is_nd_dax(dev)) {
 104                 struct nd_dax *nd_dax = to_nd_dax(dev);
 105
 106                 return &nd_dax->nd_pfn;
 107         }
 108
 109         WARN_ON(1);
 110         return NULL;
 111 }
 112
 113 static void nd_detach_and_reset(struct device *dev,
 114                 struct nd_namespace_common **_ndns)
 115 {
 116         /* detach the namespace and destroy / reset the device */
 117         __nd_detach_ndns(dev, _ndns);
 118         if (is_idle(dev, *_ndns)) {
 119                 nd_device_unregister(dev, ND_ASYNC);
 120         } else if (is_nd_btt(dev)) {
 121                 struct nd_btt *nd_btt = to_nd_btt(dev);
 122
 123                 nd_btt->lbasize = 0;
 124                 kfree(nd_btt->uuid);
 125                 nd_btt->uuid = NULL;
 126         } else if (is_nd_pfn(dev) || is_nd_dax(dev)) {
 127                 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
 128
 129                 kfree(nd_pfn->uuid);
 130                 nd_pfn->uuid = NULL;
 131                 nd_pfn->mode = PFN_MODE_NONE;
 132         }
 133 }
 134
 135 ssize_t nd_namespace_store(struct device *dev,
 136                 struct nd_namespace_common **_ndns, const char *buf,
 137                 size_t len)
 138 {
 139         struct nd_namespace_common *ndns;
 140         struct device *found;
 141         char *name;
 142
 143         if (dev->driver) {
 144                 dev_dbg(dev, "namespace already active\n");
 145                 return -EBUSY;
 146         }
 147
 148         name = kstrndup(buf, len, GFP_KERNEL);
 149         if (!name)
 150                 return -ENOMEM;
 151         strim(name);
 152
 153         if (strncmp(name, "namespace", 9) == 0 || strcmp(name, "") == 0)
 154                 /* pass */;
 155         else {
 156                 len = -EINVAL;
 157                 goto out;
 158         }
 159
 160         ndns = *_ndns;
 161         if (strcmp(name, "") == 0) {
 162                 nd_detach_and_reset(dev, _ndns);
 163                 goto out;
 164         } else if (ndns) {
 165                 dev_dbg(dev, "namespace already set to: %s\n",
 166                                 dev_name(&ndns->dev));
 167                 len = -EBUSY;
 168                 goto out;
 169         }
 170
 171         found = device_find_child(dev->parent, name, namespace_match);
 172         if (!found) {
 173                 dev_dbg(dev, "'%s' not found under %s\n", name,
 174                                 dev_name(dev->parent));
 175                 len = -ENODEV;
 176                 goto out;
 177         }
 178
 179         ndns = to_ndns(found);
 180
 181         switch (ndns->claim_class) {
 182         case NVDIMM_CCLASS_NONE:
 183                 break;
 184         case NVDIMM_CCLASS_BTT:
 185         case NVDIMM_CCLASS_BTT2:
 186                 if (!is_nd_btt(dev)) {
 187                         len = -EBUSY;
 188                         goto out_attach;
 189                 }
 190                 break;
 191         case NVDIMM_CCLASS_PFN:
 192                 if (!is_nd_pfn(dev)) {
 193                         len = -EBUSY;
 194                         goto out_attach;
 195                 }
 196                 break;
 197         case NVDIMM_CCLASS_DAX:
 198                 if (!is_nd_dax(dev)) {
 199                         len = -EBUSY;
 200                         goto out_attach;
 201                 }
 202                 break;
 203         default:
 204                 len = -EBUSY;
 205                 goto out_attach;
 206                 break;
 207         }
 208
 209         if (__nvdimm_namespace_capacity(ndns) < SZ_16M) {
 210                 dev_dbg(dev, "%s too small to host\n", name);
 211                 len = -ENXIO;
 212                 goto out_attach;
 213         }
 214
 215         WARN_ON_ONCE(!is_nvdimm_bus_locked(dev));
 216         if (!__nd_attach_ndns(dev, ndns, _ndns)) {
 217                 dev_dbg(dev, "%s already claimed\n",
 218                                 dev_name(&ndns->dev));
 219                 len = -EBUSY;
 220         }
 221
 222  out_attach:
 223         put_device(&ndns->dev); /* from device_find_child */
 224  out:
 225         kfree(name);
 226         return len;
 227 }
 228
 229 /*
 230  * nd_sb_checksum: compute checksum for a generic info block
 231  *
 232  * Returns a fletcher64 checksum of everything in the given info block
 233  * except the last field (since that's where the checksum lives).
 234  */
 235 u64 nd_sb_checksum(struct nd_gen_sb *nd_gen_sb)
 236 {
 237         u64 sum;
 238         __le64 sum_save;
 239
 240         BUILD_BUG_ON(sizeof(struct btt_sb) != SZ_4K);
 241         BUILD_BUG_ON(sizeof(struct nd_pfn_sb) != SZ_4K);
 242         BUILD_BUG_ON(sizeof(struct nd_gen_sb) != SZ_4K);
 243
 244         sum_save = nd_gen_sb->checksum;
 245         nd_gen_sb->checksum = 0;
 246         sum = nd_fletcher64(nd_gen_sb, sizeof(*nd_gen_sb), 1);
 247         nd_gen_sb->checksum = sum_save;
 248         return sum;
 249 }
 250 EXPORT_SYMBOL(nd_sb_checksum);
 251
 252 static int nsio_rw_bytes(struct nd_namespace_common *ndns,
 253                 resource_size_t offset, void *buf, size_t size, int rw,
 254                 unsigned long flags)
 255 {
 256         struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
 257         unsigned int sz_align = ALIGN(size + (offset & (512 - 1)), 512);
 258         sector_t sector = offset >> 9;
 259         int rc = 0, ret = 0;
 260
 261         if (unlikely(!size))
 262                 return 0;
 263
 264         if (unlikely(offset + size > nsio->size)) {
 265                 dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
 266                 return -EFAULT;
 267         }
 268
 269         if (rw == READ) {
 270                 if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align)))
 271                         return -EIO;
 272                 if (copy_mc_to_kernel(buf, nsio->addr + offset, size) != 0)
 273                         return -EIO;
 274                 return 0;
 275         }
 276
 277         if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align))) {
 278                 if (IS_ALIGNED(offset, 512) && IS_ALIGNED(size, 512)
 279                                 && !(flags & NVDIMM_IO_ATOMIC)) {
 280                         long cleared;
 281
 282                         might_sleep();
 283                         cleared = nvdimm_clear_poison(&ndns->dev,
 284                                         nsio->res.start + offset, size);
 285                         if (cleared < size)
 286                                 rc = -EIO;
 287                         if (cleared > 0 && cleared / 512) {
 288                                 cleared /= 512;
 289                                 badblocks_clear(&nsio->bb, sector, cleared);
 290                         }
 291                         arch_invalidate_pmem(nsio->addr + offset, size);
 292                 } else
 293                         rc = -EIO;
 294         }
 295
 296         memcpy_flushcache(nsio->addr + offset, buf, size);
 297         ret = nvdimm_flush(to_nd_region(ndns->dev.parent), NULL);
 298         if (ret)
 299                 rc = ret;
 300
 301         return rc;
 302 }
 303
 304 int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio,
 305                 resource_size_t size)
 306 {
 307         struct nd_namespace_common *ndns = &nsio->common;
 308         struct range range = {
 309                 .start = nsio->res.start,
 310                 .end = nsio->res.end,
 311         };
 312
 313         nsio->size = size;
 314         if (!devm_request_mem_region(dev, range.start, size,
 315                                 dev_name(&ndns->dev))) {
 316                 dev_warn(dev, "could not reserve region %pR\n", &nsio->res);
 317                 return -EBUSY;
 318         }
 319
 320         ndns->rw_bytes = nsio_rw_bytes;
 321         if (devm_init_badblocks(dev, &nsio->bb))
 322                 return -ENOMEM;
 323         nvdimm_badblocks_populate(to_nd_region(ndns->dev.parent), &nsio->bb,
 324                         &range);
 325
 326         nsio->addr = devm_memremap(dev, range.start, size, ARCH_MEMREMAP_PMEM);
 327
 328         return PTR_ERR_OR_ZERO(nsio->addr);
 329 }
 330
 331 void devm_nsio_disable(struct device *dev, struct nd_namespace_io *nsio)
 332 {
 333         struct resource *res = &nsio->res;
 334
 335         devm_memunmap(dev, nsio->addr);
 336         devm_exit_badblocks(dev, &nsio->bb);
 337         devm_release_mem_region(dev, res->start, nsio->size);
 338 }