Dan Williams | ab68f26 | 2016-05-18 09:15:08 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright(c) 2016 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/pagemap.h> |
| 14 | #include <linux/module.h> |
| 15 | #include <linux/device.h> |
| 16 | #include <linux/pfn_t.h> |
| 17 | #include <linux/slab.h> |
| 18 | #include <linux/dax.h> |
| 19 | #include <linux/fs.h> |
| 20 | #include <linux/mm.h> |
Dan Williams | ccdb07f | 2016-08-06 16:05:06 -0700 | [diff] [blame] | 21 | #include "dax.h" |
Dan Williams | ab68f26 | 2016-05-18 09:15:08 -0700 | [diff] [blame] | 22 | |
| 23 | static int dax_major; |
| 24 | static struct class *dax_class; |
| 25 | static DEFINE_IDA(dax_minor_ida); |
| 26 | |
| 27 | /** |
| 28 | * struct dax_region - mapping infrastructure for dax devices |
| 29 | * @id: kernel-wide unique region for a memory range |
| 30 | * @base: linear address corresponding to @res |
| 31 | * @kref: to pin while other agents have a need to do lookups |
| 32 | * @dev: parent device backing this region |
| 33 | * @align: allocation and mapping alignment for child dax devices |
| 34 | * @res: physical address range of the region |
| 35 | * @pfn_flags: identify whether the pfns are paged back or not |
| 36 | */ |
| 37 | struct dax_region { |
| 38 | int id; |
| 39 | struct ida ida; |
| 40 | void *base; |
| 41 | struct kref kref; |
| 42 | struct device *dev; |
| 43 | unsigned int align; |
| 44 | struct resource res; |
| 45 | unsigned long pfn_flags; |
| 46 | }; |
| 47 | |
| 48 | /** |
| 49 | * struct dax_dev - subdivision of a dax region |
| 50 | * @region - parent region |
| 51 | * @dev - device backing the character device |
| 52 | * @kref - enable this data to be tracked in filp->private_data |
Dan Williams | dee4107 | 2016-05-14 12:20:44 -0700 | [diff] [blame] | 53 | * @alive - !alive + rcu grace period == no new mappings can be established |
Dan Williams | ab68f26 | 2016-05-18 09:15:08 -0700 | [diff] [blame] | 54 | * @id - child id in the region |
| 55 | * @num_resources - number of physical address extents in this device |
| 56 | * @res - array of physical address ranges |
| 57 | */ |
| 58 | struct dax_dev { |
| 59 | struct dax_region *region; |
| 60 | struct device *dev; |
| 61 | struct kref kref; |
Dan Williams | dee4107 | 2016-05-14 12:20:44 -0700 | [diff] [blame] | 62 | bool alive; |
Dan Williams | ab68f26 | 2016-05-18 09:15:08 -0700 | [diff] [blame] | 63 | int id; |
| 64 | int num_resources; |
| 65 | struct resource res[0]; |
| 66 | }; |
| 67 | |
| 68 | static void dax_region_free(struct kref *kref) |
| 69 | { |
| 70 | struct dax_region *dax_region; |
| 71 | |
| 72 | dax_region = container_of(kref, struct dax_region, kref); |
| 73 | kfree(dax_region); |
| 74 | } |
| 75 | |
| 76 | void dax_region_put(struct dax_region *dax_region) |
| 77 | { |
| 78 | kref_put(&dax_region->kref, dax_region_free); |
| 79 | } |
| 80 | EXPORT_SYMBOL_GPL(dax_region_put); |
| 81 | |
| 82 | static void dax_dev_free(struct kref *kref) |
| 83 | { |
| 84 | struct dax_dev *dax_dev; |
| 85 | |
| 86 | dax_dev = container_of(kref, struct dax_dev, kref); |
| 87 | dax_region_put(dax_dev->region); |
| 88 | kfree(dax_dev); |
| 89 | } |
| 90 | |
| 91 | static void dax_dev_put(struct dax_dev *dax_dev) |
| 92 | { |
| 93 | kref_put(&dax_dev->kref, dax_dev_free); |
| 94 | } |
| 95 | |
| 96 | struct dax_region *alloc_dax_region(struct device *parent, int region_id, |
| 97 | struct resource *res, unsigned int align, void *addr, |
| 98 | unsigned long pfn_flags) |
| 99 | { |
| 100 | struct dax_region *dax_region; |
| 101 | |
| 102 | dax_region = kzalloc(sizeof(*dax_region), GFP_KERNEL); |
| 103 | |
| 104 | if (!dax_region) |
| 105 | return NULL; |
| 106 | |
| 107 | memcpy(&dax_region->res, res, sizeof(*res)); |
| 108 | dax_region->pfn_flags = pfn_flags; |
| 109 | kref_init(&dax_region->kref); |
| 110 | dax_region->id = region_id; |
| 111 | ida_init(&dax_region->ida); |
| 112 | dax_region->align = align; |
| 113 | dax_region->dev = parent; |
| 114 | dax_region->base = addr; |
| 115 | |
| 116 | return dax_region; |
| 117 | } |
| 118 | EXPORT_SYMBOL_GPL(alloc_dax_region); |
| 119 | |
| 120 | static ssize_t size_show(struct device *dev, |
| 121 | struct device_attribute *attr, char *buf) |
| 122 | { |
| 123 | struct dax_dev *dax_dev = dev_get_drvdata(dev); |
| 124 | unsigned long long size = 0; |
| 125 | int i; |
| 126 | |
| 127 | for (i = 0; i < dax_dev->num_resources; i++) |
| 128 | size += resource_size(&dax_dev->res[i]); |
| 129 | |
| 130 | return sprintf(buf, "%llu\n", size); |
| 131 | } |
| 132 | static DEVICE_ATTR_RO(size); |
| 133 | |
| 134 | static struct attribute *dax_device_attributes[] = { |
| 135 | &dev_attr_size.attr, |
| 136 | NULL, |
| 137 | }; |
| 138 | |
| 139 | static const struct attribute_group dax_device_attribute_group = { |
| 140 | .attrs = dax_device_attributes, |
| 141 | }; |
| 142 | |
| 143 | static const struct attribute_group *dax_attribute_groups[] = { |
| 144 | &dax_device_attribute_group, |
| 145 | NULL, |
| 146 | }; |
| 147 | |
Dan Williams | dee4107 | 2016-05-14 12:20:44 -0700 | [diff] [blame] | 148 | static int check_vma(struct dax_dev *dax_dev, struct vm_area_struct *vma, |
| 149 | const char *func) |
| 150 | { |
| 151 | struct dax_region *dax_region = dax_dev->region; |
| 152 | struct device *dev = dax_dev->dev; |
| 153 | unsigned long mask; |
| 154 | |
| 155 | if (!dax_dev->alive) |
| 156 | return -ENXIO; |
| 157 | |
| 158 | /* prevent private / writable mappings from being established */ |
| 159 | if ((vma->vm_flags & (VM_NORESERVE|VM_SHARED|VM_WRITE)) == VM_WRITE) { |
| 160 | dev_info(dev, "%s: %s: fail, attempted private mapping\n", |
| 161 | current->comm, func); |
| 162 | return -EINVAL; |
| 163 | } |
| 164 | |
| 165 | mask = dax_region->align - 1; |
| 166 | if (vma->vm_start & mask || vma->vm_end & mask) { |
| 167 | dev_info(dev, "%s: %s: fail, unaligned vma (%#lx - %#lx, %#lx)\n", |
| 168 | current->comm, func, vma->vm_start, vma->vm_end, |
| 169 | mask); |
| 170 | return -EINVAL; |
| 171 | } |
| 172 | |
| 173 | if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) == PFN_DEV |
| 174 | && (vma->vm_flags & VM_DONTCOPY) == 0) { |
| 175 | dev_info(dev, "%s: %s: fail, dax range requires MADV_DONTFORK\n", |
| 176 | current->comm, func); |
| 177 | return -EINVAL; |
| 178 | } |
| 179 | |
| 180 | if (!vma_is_dax(vma)) { |
| 181 | dev_info(dev, "%s: %s: fail, vma is not DAX capable\n", |
| 182 | current->comm, func); |
| 183 | return -EINVAL; |
| 184 | } |
| 185 | |
| 186 | return 0; |
| 187 | } |
| 188 | |
| 189 | static phys_addr_t pgoff_to_phys(struct dax_dev *dax_dev, pgoff_t pgoff, |
| 190 | unsigned long size) |
| 191 | { |
| 192 | struct resource *res; |
| 193 | phys_addr_t phys; |
| 194 | int i; |
| 195 | |
| 196 | for (i = 0; i < dax_dev->num_resources; i++) { |
| 197 | res = &dax_dev->res[i]; |
| 198 | phys = pgoff * PAGE_SIZE + res->start; |
| 199 | if (phys >= res->start && phys <= res->end) |
| 200 | break; |
| 201 | pgoff -= PHYS_PFN(resource_size(res)); |
| 202 | } |
| 203 | |
| 204 | if (i < dax_dev->num_resources) { |
| 205 | res = &dax_dev->res[i]; |
| 206 | if (phys + size - 1 <= res->end) |
| 207 | return phys; |
| 208 | } |
| 209 | |
| 210 | return -1; |
| 211 | } |
| 212 | |
| 213 | static int __dax_dev_fault(struct dax_dev *dax_dev, struct vm_area_struct *vma, |
| 214 | struct vm_fault *vmf) |
| 215 | { |
| 216 | unsigned long vaddr = (unsigned long) vmf->virtual_address; |
| 217 | struct device *dev = dax_dev->dev; |
| 218 | struct dax_region *dax_region; |
| 219 | int rc = VM_FAULT_SIGBUS; |
| 220 | phys_addr_t phys; |
| 221 | pfn_t pfn; |
| 222 | |
| 223 | if (check_vma(dax_dev, vma, __func__)) |
| 224 | return VM_FAULT_SIGBUS; |
| 225 | |
| 226 | dax_region = dax_dev->region; |
| 227 | if (dax_region->align > PAGE_SIZE) { |
| 228 | dev_dbg(dev, "%s: alignment > fault size\n", __func__); |
| 229 | return VM_FAULT_SIGBUS; |
| 230 | } |
| 231 | |
| 232 | phys = pgoff_to_phys(dax_dev, vmf->pgoff, PAGE_SIZE); |
| 233 | if (phys == -1) { |
| 234 | dev_dbg(dev, "%s: phys_to_pgoff(%#lx) failed\n", __func__, |
| 235 | vmf->pgoff); |
| 236 | return VM_FAULT_SIGBUS; |
| 237 | } |
| 238 | |
| 239 | pfn = phys_to_pfn_t(phys, dax_region->pfn_flags); |
| 240 | |
| 241 | rc = vm_insert_mixed(vma, vaddr, pfn); |
| 242 | |
| 243 | if (rc == -ENOMEM) |
| 244 | return VM_FAULT_OOM; |
| 245 | if (rc < 0 && rc != -EBUSY) |
| 246 | return VM_FAULT_SIGBUS; |
| 247 | |
| 248 | return VM_FAULT_NOPAGE; |
| 249 | } |
| 250 | |
| 251 | static int dax_dev_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
| 252 | { |
| 253 | int rc; |
| 254 | struct file *filp = vma->vm_file; |
| 255 | struct dax_dev *dax_dev = filp->private_data; |
| 256 | |
| 257 | dev_dbg(dax_dev->dev, "%s: %s: %s (%#lx - %#lx)\n", __func__, |
| 258 | current->comm, (vmf->flags & FAULT_FLAG_WRITE) |
| 259 | ? "write" : "read", vma->vm_start, vma->vm_end); |
| 260 | rcu_read_lock(); |
| 261 | rc = __dax_dev_fault(dax_dev, vma, vmf); |
| 262 | rcu_read_unlock(); |
| 263 | |
| 264 | return rc; |
| 265 | } |
| 266 | |
| 267 | static int __dax_dev_pmd_fault(struct dax_dev *dax_dev, |
| 268 | struct vm_area_struct *vma, unsigned long addr, pmd_t *pmd, |
| 269 | unsigned int flags) |
| 270 | { |
| 271 | unsigned long pmd_addr = addr & PMD_MASK; |
| 272 | struct device *dev = dax_dev->dev; |
| 273 | struct dax_region *dax_region; |
| 274 | phys_addr_t phys; |
| 275 | pgoff_t pgoff; |
| 276 | pfn_t pfn; |
| 277 | |
| 278 | if (check_vma(dax_dev, vma, __func__)) |
| 279 | return VM_FAULT_SIGBUS; |
| 280 | |
| 281 | dax_region = dax_dev->region; |
| 282 | if (dax_region->align > PMD_SIZE) { |
| 283 | dev_dbg(dev, "%s: alignment > fault size\n", __func__); |
| 284 | return VM_FAULT_SIGBUS; |
| 285 | } |
| 286 | |
| 287 | /* dax pmd mappings require pfn_t_devmap() */ |
| 288 | if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) != (PFN_DEV|PFN_MAP)) { |
| 289 | dev_dbg(dev, "%s: alignment > fault size\n", __func__); |
| 290 | return VM_FAULT_SIGBUS; |
| 291 | } |
| 292 | |
| 293 | pgoff = linear_page_index(vma, pmd_addr); |
| 294 | phys = pgoff_to_phys(dax_dev, pgoff, PAGE_SIZE); |
| 295 | if (phys == -1) { |
| 296 | dev_dbg(dev, "%s: phys_to_pgoff(%#lx) failed\n", __func__, |
| 297 | pgoff); |
| 298 | return VM_FAULT_SIGBUS; |
| 299 | } |
| 300 | |
| 301 | pfn = phys_to_pfn_t(phys, dax_region->pfn_flags); |
| 302 | |
| 303 | return vmf_insert_pfn_pmd(vma, addr, pmd, pfn, |
| 304 | flags & FAULT_FLAG_WRITE); |
| 305 | } |
| 306 | |
| 307 | static int dax_dev_pmd_fault(struct vm_area_struct *vma, unsigned long addr, |
| 308 | pmd_t *pmd, unsigned int flags) |
| 309 | { |
| 310 | int rc; |
| 311 | struct file *filp = vma->vm_file; |
| 312 | struct dax_dev *dax_dev = filp->private_data; |
| 313 | |
| 314 | dev_dbg(dax_dev->dev, "%s: %s: %s (%#lx - %#lx)\n", __func__, |
| 315 | current->comm, (flags & FAULT_FLAG_WRITE) |
| 316 | ? "write" : "read", vma->vm_start, vma->vm_end); |
| 317 | |
| 318 | rcu_read_lock(); |
| 319 | rc = __dax_dev_pmd_fault(dax_dev, vma, addr, pmd, flags); |
| 320 | rcu_read_unlock(); |
| 321 | |
| 322 | return rc; |
| 323 | } |
| 324 | |
| 325 | static void dax_dev_vm_open(struct vm_area_struct *vma) |
| 326 | { |
| 327 | struct file *filp = vma->vm_file; |
| 328 | struct dax_dev *dax_dev = filp->private_data; |
| 329 | |
| 330 | dev_dbg(dax_dev->dev, "%s\n", __func__); |
| 331 | kref_get(&dax_dev->kref); |
| 332 | } |
| 333 | |
| 334 | static void dax_dev_vm_close(struct vm_area_struct *vma) |
| 335 | { |
| 336 | struct file *filp = vma->vm_file; |
| 337 | struct dax_dev *dax_dev = filp->private_data; |
| 338 | |
| 339 | dev_dbg(dax_dev->dev, "%s\n", __func__); |
| 340 | dax_dev_put(dax_dev); |
| 341 | } |
| 342 | |
| 343 | static const struct vm_operations_struct dax_dev_vm_ops = { |
| 344 | .fault = dax_dev_fault, |
| 345 | .pmd_fault = dax_dev_pmd_fault, |
| 346 | .open = dax_dev_vm_open, |
| 347 | .close = dax_dev_vm_close, |
| 348 | }; |
| 349 | |
| 350 | static int dax_dev_mmap(struct file *filp, struct vm_area_struct *vma) |
| 351 | { |
| 352 | struct dax_dev *dax_dev = filp->private_data; |
| 353 | int rc; |
| 354 | |
| 355 | dev_dbg(dax_dev->dev, "%s\n", __func__); |
| 356 | |
| 357 | rc = check_vma(dax_dev, vma, __func__); |
| 358 | if (rc) |
| 359 | return rc; |
| 360 | |
| 361 | kref_get(&dax_dev->kref); |
| 362 | vma->vm_ops = &dax_dev_vm_ops; |
| 363 | vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE; |
| 364 | return 0; |
Dan Williams | 043a925 | 2016-08-07 08:23:56 -0700 | [diff] [blame^] | 365 | } |
Dan Williams | dee4107 | 2016-05-14 12:20:44 -0700 | [diff] [blame] | 366 | |
Dan Williams | 043a925 | 2016-08-07 08:23:56 -0700 | [diff] [blame^] | 367 | /* return an unmapped area aligned to the dax region specified alignment */ |
| 368 | static unsigned long dax_dev_get_unmapped_area(struct file *filp, |
| 369 | unsigned long addr, unsigned long len, unsigned long pgoff, |
| 370 | unsigned long flags) |
| 371 | { |
| 372 | unsigned long off, off_end, off_align, len_align, addr_align, align; |
| 373 | struct dax_dev *dax_dev = filp ? filp->private_data : NULL; |
| 374 | struct dax_region *dax_region; |
| 375 | |
| 376 | if (!dax_dev || addr) |
| 377 | goto out; |
| 378 | |
| 379 | dax_region = dax_dev->region; |
| 380 | align = dax_region->align; |
| 381 | off = pgoff << PAGE_SHIFT; |
| 382 | off_end = off + len; |
| 383 | off_align = round_up(off, align); |
| 384 | |
| 385 | if ((off_end <= off_align) || ((off_end - off_align) < align)) |
| 386 | goto out; |
| 387 | |
| 388 | len_align = len + align; |
| 389 | if ((off + len_align) < off) |
| 390 | goto out; |
| 391 | |
| 392 | addr_align = current->mm->get_unmapped_area(filp, addr, len_align, |
| 393 | pgoff, flags); |
| 394 | if (!IS_ERR_VALUE(addr_align)) { |
| 395 | addr_align += (off - addr_align) & (align - 1); |
| 396 | return addr_align; |
| 397 | } |
| 398 | out: |
| 399 | return current->mm->get_unmapped_area(filp, addr, len, pgoff, flags); |
| 400 | } |
| 401 | |
| 402 | static int __match_devt(struct device *dev, const void *data) |
| 403 | { |
| 404 | const dev_t *devt = data; |
| 405 | |
| 406 | return dev->devt == *devt; |
| 407 | } |
| 408 | |
| 409 | static struct device *dax_dev_find(dev_t dev_t) |
| 410 | { |
| 411 | return class_find_device(dax_class, NULL, &dev_t, __match_devt); |
| 412 | } |
| 413 | |
| 414 | static int dax_dev_open(struct inode *inode, struct file *filp) |
| 415 | { |
| 416 | struct dax_dev *dax_dev = NULL; |
| 417 | struct device *dev; |
| 418 | |
| 419 | dev = dax_dev_find(inode->i_rdev); |
| 420 | if (!dev) |
| 421 | return -ENXIO; |
| 422 | |
| 423 | device_lock(dev); |
| 424 | dax_dev = dev_get_drvdata(dev); |
| 425 | if (dax_dev) { |
| 426 | dev_dbg(dev, "%s\n", __func__); |
| 427 | filp->private_data = dax_dev; |
| 428 | kref_get(&dax_dev->kref); |
| 429 | inode->i_flags = S_DAX; |
| 430 | } |
| 431 | device_unlock(dev); |
| 432 | |
| 433 | if (!dax_dev) { |
| 434 | put_device(dev); |
| 435 | return -ENXIO; |
| 436 | } |
| 437 | return 0; |
| 438 | } |
| 439 | |
| 440 | static int dax_dev_release(struct inode *inode, struct file *filp) |
| 441 | { |
| 442 | struct dax_dev *dax_dev = filp->private_data; |
| 443 | struct device *dev = dax_dev->dev; |
| 444 | |
| 445 | dev_dbg(dax_dev->dev, "%s\n", __func__); |
| 446 | dax_dev_put(dax_dev); |
| 447 | put_device(dev); |
| 448 | |
| 449 | return 0; |
Dan Williams | dee4107 | 2016-05-14 12:20:44 -0700 | [diff] [blame] | 450 | } |
| 451 | |
Dan Williams | ab68f26 | 2016-05-18 09:15:08 -0700 | [diff] [blame] | 452 | static const struct file_operations dax_fops = { |
| 453 | .llseek = noop_llseek, |
| 454 | .owner = THIS_MODULE, |
Dan Williams | dee4107 | 2016-05-14 12:20:44 -0700 | [diff] [blame] | 455 | .open = dax_dev_open, |
| 456 | .release = dax_dev_release, |
| 457 | .get_unmapped_area = dax_dev_get_unmapped_area, |
| 458 | .mmap = dax_dev_mmap, |
Dan Williams | ab68f26 | 2016-05-18 09:15:08 -0700 | [diff] [blame] | 459 | }; |
| 460 | |
Dan Williams | 043a925 | 2016-08-07 08:23:56 -0700 | [diff] [blame^] | 461 | static void unregister_dax_dev(void *_dev) |
| 462 | { |
| 463 | struct device *dev = _dev; |
| 464 | struct dax_dev *dax_dev = dev_get_drvdata(dev); |
| 465 | struct dax_region *dax_region = dax_dev->region; |
| 466 | |
| 467 | dev_dbg(dev, "%s\n", __func__); |
| 468 | |
| 469 | /* |
| 470 | * Note, rcu is not protecting the liveness of dax_dev, rcu is |
| 471 | * ensuring that any fault handlers that might have seen |
| 472 | * dax_dev->alive == true, have completed. Any fault handlers |
| 473 | * that start after synchronize_rcu() has started will abort |
| 474 | * upon seeing dax_dev->alive == false. |
| 475 | */ |
| 476 | dax_dev->alive = false; |
| 477 | synchronize_rcu(); |
| 478 | |
| 479 | get_device(dev); |
| 480 | device_unregister(dev); |
| 481 | ida_simple_remove(&dax_region->ida, dax_dev->id); |
| 482 | ida_simple_remove(&dax_minor_ida, MINOR(dev->devt)); |
| 483 | put_device(dev); |
| 484 | dax_dev_put(dax_dev); |
| 485 | } |
| 486 | |
| 487 | int devm_create_dax_dev(struct dax_region *dax_region, struct resource *res, |
| 488 | int count) |
| 489 | { |
| 490 | struct device *parent = dax_region->dev; |
| 491 | struct dax_dev *dax_dev; |
| 492 | struct device *dev; |
| 493 | int rc, minor; |
| 494 | dev_t dev_t; |
| 495 | |
| 496 | dax_dev = kzalloc(sizeof(*dax_dev) + sizeof(*res) * count, GFP_KERNEL); |
| 497 | if (!dax_dev) |
| 498 | return -ENOMEM; |
| 499 | memcpy(dax_dev->res, res, sizeof(*res) * count); |
| 500 | dax_dev->num_resources = count; |
| 501 | kref_init(&dax_dev->kref); |
| 502 | dax_dev->alive = true; |
| 503 | dax_dev->region = dax_region; |
| 504 | kref_get(&dax_region->kref); |
| 505 | |
| 506 | dax_dev->id = ida_simple_get(&dax_region->ida, 0, 0, GFP_KERNEL); |
| 507 | if (dax_dev->id < 0) { |
| 508 | rc = dax_dev->id; |
| 509 | goto err_id; |
| 510 | } |
| 511 | |
| 512 | minor = ida_simple_get(&dax_minor_ida, 0, 0, GFP_KERNEL); |
| 513 | if (minor < 0) { |
| 514 | rc = minor; |
| 515 | goto err_minor; |
| 516 | } |
| 517 | |
| 518 | dev_t = MKDEV(dax_major, minor); |
| 519 | dev = device_create_with_groups(dax_class, parent, dev_t, dax_dev, |
| 520 | dax_attribute_groups, "dax%d.%d", dax_region->id, |
| 521 | dax_dev->id); |
| 522 | if (IS_ERR(dev)) { |
| 523 | rc = PTR_ERR(dev); |
| 524 | goto err_create; |
| 525 | } |
| 526 | dax_dev->dev = dev; |
| 527 | |
| 528 | rc = devm_add_action_or_reset(dax_region->dev, unregister_dax_dev, dev); |
| 529 | if (rc) |
| 530 | return rc; |
| 531 | |
| 532 | return 0; |
| 533 | |
| 534 | err_create: |
| 535 | ida_simple_remove(&dax_minor_ida, minor); |
| 536 | err_minor: |
| 537 | ida_simple_remove(&dax_region->ida, dax_dev->id); |
| 538 | err_id: |
| 539 | dax_dev_put(dax_dev); |
| 540 | |
| 541 | return rc; |
| 542 | } |
| 543 | EXPORT_SYMBOL_GPL(devm_create_dax_dev); |
| 544 | |
Dan Williams | ab68f26 | 2016-05-18 09:15:08 -0700 | [diff] [blame] | 545 | static int __init dax_init(void) |
| 546 | { |
| 547 | int rc; |
| 548 | |
| 549 | rc = register_chrdev(0, "dax", &dax_fops); |
| 550 | if (rc < 0) |
| 551 | return rc; |
| 552 | dax_major = rc; |
| 553 | |
| 554 | dax_class = class_create(THIS_MODULE, "dax"); |
| 555 | if (IS_ERR(dax_class)) { |
| 556 | unregister_chrdev(dax_major, "dax"); |
| 557 | return PTR_ERR(dax_class); |
| 558 | } |
| 559 | |
| 560 | return 0; |
| 561 | } |
| 562 | |
| 563 | static void __exit dax_exit(void) |
| 564 | { |
| 565 | class_destroy(dax_class); |
| 566 | unregister_chrdev(dax_major, "dax"); |
| 567 | ida_destroy(&dax_minor_ida); |
| 568 | } |
| 569 | |
| 570 | MODULE_AUTHOR("Intel Corporation"); |
| 571 | MODULE_LICENSE("GPL v2"); |
| 572 | subsys_initcall(dax_init); |
| 573 | module_exit(dax_exit); |