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/device.h> 14 #include <linux/sizes.h> 15 #include <linux/pmem.h> 16 #include "nd-core.h" 17 #include "pfn.h" 18 #include "btt.h" 19 #include "nd.h" 20 21 void __nd_detach_ndns(struct device *dev, struct nd_namespace_common **_ndns) 22 { 23 struct nd_namespace_common *ndns = *_ndns; 24 25 lockdep_assert_held(&ndns->dev.mutex); 26 dev_WARN_ONCE(dev, ndns->claim != dev, "%s: invalid claim\n", __func__); 27 ndns->claim = NULL; 28 *_ndns = NULL; 29 put_device(&ndns->dev); 30 } 31 32 void nd_detach_ndns(struct device *dev, 33 struct nd_namespace_common **_ndns) 34 { 35 struct nd_namespace_common *ndns = *_ndns; 36 37 if (!ndns) 38 return; 39 get_device(&ndns->dev); 40 device_lock(&ndns->dev); 41 __nd_detach_ndns(dev, _ndns); 42 device_unlock(&ndns->dev); 43 put_device(&ndns->dev); 44 } 45 46 bool __nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach, 47 struct nd_namespace_common **_ndns) 48 { 49 if (attach->claim) 50 return false; 51 lockdep_assert_held(&attach->dev.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 device_lock(&attach->dev); 65 claimed = __nd_attach_ndns(dev, attach, _ndns); 66 device_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, "%s: -EBUSY\n", __func__); 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 if (__nvdimm_namespace_capacity(ndns) < SZ_16M) { 181 dev_dbg(dev, "%s too small to host\n", name); 182 len = -ENXIO; 183 goto out_attach; 184 } 185 186 WARN_ON_ONCE(!is_nvdimm_bus_locked(dev)); 187 if (!nd_attach_ndns(dev, ndns, _ndns)) { 188 dev_dbg(dev, "%s already claimed\n", 189 dev_name(&ndns->dev)); 190 len = -EBUSY; 191 } 192 193 out_attach: 194 put_device(&ndns->dev); /* from device_find_child */ 195 out: 196 kfree(name); 197 return len; 198 } 199 200 /* 201 * nd_sb_checksum: compute checksum for a generic info block 202 * 203 * Returns a fletcher64 checksum of everything in the given info block 204 * except the last field (since that's where the checksum lives). 205 */ 206 u64 nd_sb_checksum(struct nd_gen_sb *nd_gen_sb) 207 { 208 u64 sum; 209 __le64 sum_save; 210 211 BUILD_BUG_ON(sizeof(struct btt_sb) != SZ_4K); 212 BUILD_BUG_ON(sizeof(struct nd_pfn_sb) != SZ_4K); 213 BUILD_BUG_ON(sizeof(struct nd_gen_sb) != SZ_4K); 214 215 sum_save = nd_gen_sb->checksum; 216 nd_gen_sb->checksum = 0; 217 sum = nd_fletcher64(nd_gen_sb, sizeof(*nd_gen_sb), 1); 218 nd_gen_sb->checksum = sum_save; 219 return sum; 220 } 221 EXPORT_SYMBOL(nd_sb_checksum); 222 223 static int nsio_rw_bytes(struct nd_namespace_common *ndns, 224 resource_size_t offset, void *buf, size_t size, int rw) 225 { 226 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev); 227 unsigned int sz_align = ALIGN(size + (offset & (512 - 1)), 512); 228 sector_t sector = offset >> 9; 229 int rc = 0; 230 231 if (unlikely(!size)) 232 return 0; 233 234 if (unlikely(offset + size > nsio->size)) { 235 dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n"); 236 return -EFAULT; 237 } 238 239 if (rw == READ) { 240 if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align))) 241 return -EIO; 242 return memcpy_from_pmem(buf, nsio->addr + offset, size); 243 } 244 245 if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align))) { 246 if (IS_ALIGNED(offset, 512) && IS_ALIGNED(size, 512)) { 247 long cleared; 248 249 cleared = nvdimm_clear_poison(&ndns->dev, offset, size); 250 if (cleared < size) 251 rc = -EIO; 252 if (cleared > 0 && cleared / 512) { 253 cleared /= 512; 254 badblocks_clear(&nsio->bb, sector, cleared); 255 } 256 invalidate_pmem(nsio->addr + offset, size); 257 } else 258 rc = -EIO; 259 } 260 261 memcpy_to_pmem(nsio->addr + offset, buf, size); 262 nvdimm_flush(to_nd_region(ndns->dev.parent)); 263 264 return rc; 265 } 266 267 int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio) 268 { 269 struct resource *res = &nsio->res; 270 struct nd_namespace_common *ndns = &nsio->common; 271 272 nsio->size = resource_size(res); 273 if (!devm_request_mem_region(dev, res->start, resource_size(res), 274 dev_name(&ndns->dev))) { 275 dev_warn(dev, "could not reserve region %pR\n", res); 276 return -EBUSY; 277 } 278 279 ndns->rw_bytes = nsio_rw_bytes; 280 if (devm_init_badblocks(dev, &nsio->bb)) 281 return -ENOMEM; 282 nvdimm_badblocks_populate(to_nd_region(ndns->dev.parent), &nsio->bb, 283 &nsio->res); 284 285 nsio->addr = devm_memremap(dev, res->start, resource_size(res), 286 ARCH_MEMREMAP_PMEM); 287 288 return PTR_ERR_OR_ZERO(nsio->addr); 289 } 290 EXPORT_SYMBOL_GPL(devm_nsio_enable); 291 292 void devm_nsio_disable(struct device *dev, struct nd_namespace_io *nsio) 293 { 294 struct resource *res = &nsio->res; 295 296 devm_memunmap(dev, nsio->addr); 297 devm_exit_badblocks(dev, &nsio->bb); 298 devm_release_mem_region(dev, res->start, resource_size(res)); 299 } 300 EXPORT_SYMBOL_GPL(devm_nsio_disable); 301