Commit | Line | Data |
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ab68f262 DW |
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> | |
3bc52c45 | 16 | #include <linux/mount.h> |
ab68f262 | 17 | #include <linux/pfn_t.h> |
3bc52c45 | 18 | #include <linux/hash.h> |
ba09c01d | 19 | #include <linux/cdev.h> |
ab68f262 DW |
20 | #include <linux/slab.h> |
21 | #include <linux/dax.h> | |
22 | #include <linux/fs.h> | |
23 | #include <linux/mm.h> | |
ccdb07f6 | 24 | #include "dax.h" |
ab68f262 | 25 | |
ba09c01d | 26 | static dev_t dax_devt; |
ab68f262 DW |
27 | static struct class *dax_class; |
28 | static DEFINE_IDA(dax_minor_ida); | |
ba09c01d DW |
29 | static int nr_dax = CONFIG_NR_DEV_DAX; |
30 | module_param(nr_dax, int, S_IRUGO); | |
3bc52c45 DW |
31 | static struct vfsmount *dax_mnt; |
32 | static struct kmem_cache *dax_cache __read_mostly; | |
33 | static struct super_block *dax_superblock __read_mostly; | |
ba09c01d | 34 | MODULE_PARM_DESC(nr_dax, "max number of device-dax instances"); |
ab68f262 DW |
35 | |
36 | /** | |
37 | * struct dax_region - mapping infrastructure for dax devices | |
38 | * @id: kernel-wide unique region for a memory range | |
39 | * @base: linear address corresponding to @res | |
40 | * @kref: to pin while other agents have a need to do lookups | |
41 | * @dev: parent device backing this region | |
42 | * @align: allocation and mapping alignment for child dax devices | |
43 | * @res: physical address range of the region | |
44 | * @pfn_flags: identify whether the pfns are paged back or not | |
45 | */ | |
46 | struct dax_region { | |
47 | int id; | |
48 | struct ida ida; | |
49 | void *base; | |
50 | struct kref kref; | |
51 | struct device *dev; | |
52 | unsigned int align; | |
53 | struct resource res; | |
54 | unsigned long pfn_flags; | |
55 | }; | |
56 | ||
57 | /** | |
58 | * struct dax_dev - subdivision of a dax region | |
59 | * @region - parent region | |
60 | * @dev - device backing the character device | |
ba09c01d | 61 | * @cdev - core chardev data |
dee41079 | 62 | * @alive - !alive + rcu grace period == no new mappings can be established |
ab68f262 DW |
63 | * @id - child id in the region |
64 | * @num_resources - number of physical address extents in this device | |
65 | * @res - array of physical address ranges | |
66 | */ | |
67 | struct dax_dev { | |
68 | struct dax_region *region; | |
3bc52c45 | 69 | struct inode *inode; |
ebd84d72 | 70 | struct device dev; |
ba09c01d | 71 | struct cdev cdev; |
dee41079 | 72 | bool alive; |
ab68f262 DW |
73 | int id; |
74 | int num_resources; | |
75 | struct resource res[0]; | |
76 | }; | |
77 | ||
3bc52c45 | 78 | static struct inode *dax_alloc_inode(struct super_block *sb) |
ab68f262 | 79 | { |
3bc52c45 DW |
80 | return kmem_cache_alloc(dax_cache, GFP_KERNEL); |
81 | } | |
ab68f262 | 82 | |
3bc52c45 DW |
83 | static void dax_i_callback(struct rcu_head *head) |
84 | { | |
85 | struct inode *inode = container_of(head, struct inode, i_rcu); | |
86 | ||
87 | kmem_cache_free(dax_cache, inode); | |
ab68f262 DW |
88 | } |
89 | ||
3bc52c45 | 90 | static void dax_destroy_inode(struct inode *inode) |
ab68f262 | 91 | { |
3bc52c45 | 92 | call_rcu(&inode->i_rcu, dax_i_callback); |
ab68f262 | 93 | } |
ab68f262 | 94 | |
3bc52c45 DW |
95 | static const struct super_operations dax_sops = { |
96 | .statfs = simple_statfs, | |
97 | .alloc_inode = dax_alloc_inode, | |
98 | .destroy_inode = dax_destroy_inode, | |
99 | .drop_inode = generic_delete_inode, | |
100 | }; | |
101 | ||
102 | static struct dentry *dax_mount(struct file_system_type *fs_type, | |
103 | int flags, const char *dev_name, void *data) | |
ab68f262 | 104 | { |
3bc52c45 DW |
105 | return mount_pseudo(fs_type, "dax:", &dax_sops, NULL, DAXFS_MAGIC); |
106 | } | |
ab68f262 | 107 | |
3bc52c45 DW |
108 | static struct file_system_type dax_type = { |
109 | .name = "dax", | |
110 | .mount = dax_mount, | |
111 | .kill_sb = kill_anon_super, | |
112 | }; | |
113 | ||
114 | static int dax_test(struct inode *inode, void *data) | |
115 | { | |
116 | return inode->i_cdev == data; | |
117 | } | |
118 | ||
119 | static int dax_set(struct inode *inode, void *data) | |
120 | { | |
121 | inode->i_cdev = data; | |
122 | return 0; | |
123 | } | |
124 | ||
125 | static struct inode *dax_inode_get(struct cdev *cdev, dev_t devt) | |
126 | { | |
127 | struct inode *inode; | |
128 | ||
129 | inode = iget5_locked(dax_superblock, hash_32(devt + DAXFS_MAGIC, 31), | |
130 | dax_test, dax_set, cdev); | |
131 | ||
132 | if (!inode) | |
133 | return NULL; | |
134 | ||
135 | if (inode->i_state & I_NEW) { | |
136 | inode->i_mode = S_IFCHR; | |
137 | inode->i_flags = S_DAX; | |
138 | inode->i_rdev = devt; | |
139 | mapping_set_gfp_mask(&inode->i_data, GFP_USER); | |
140 | unlock_new_inode(inode); | |
141 | } | |
142 | return inode; | |
143 | } | |
144 | ||
145 | static void init_once(void *inode) | |
146 | { | |
147 | inode_init_once(inode); | |
148 | } | |
149 | ||
150 | static int dax_inode_init(void) | |
151 | { | |
152 | int rc; | |
153 | ||
154 | dax_cache = kmem_cache_create("dax_cache", sizeof(struct inode), 0, | |
155 | (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| | |
156 | SLAB_MEM_SPREAD|SLAB_ACCOUNT), | |
157 | init_once); | |
158 | if (!dax_cache) | |
159 | return -ENOMEM; | |
160 | ||
161 | rc = register_filesystem(&dax_type); | |
162 | if (rc) | |
163 | goto err_register_fs; | |
164 | ||
165 | dax_mnt = kern_mount(&dax_type); | |
166 | if (IS_ERR(dax_mnt)) { | |
167 | rc = PTR_ERR(dax_mnt); | |
168 | goto err_mount; | |
169 | } | |
170 | dax_superblock = dax_mnt->mnt_sb; | |
171 | ||
172 | return 0; | |
173 | ||
174 | err_mount: | |
175 | unregister_filesystem(&dax_type); | |
176 | err_register_fs: | |
177 | kmem_cache_destroy(dax_cache); | |
178 | ||
179 | return rc; | |
ab68f262 DW |
180 | } |
181 | ||
3bc52c45 DW |
182 | static void dax_inode_exit(void) |
183 | { | |
184 | kern_unmount(dax_mnt); | |
185 | unregister_filesystem(&dax_type); | |
186 | kmem_cache_destroy(dax_cache); | |
187 | } | |
188 | ||
ab68f262 DW |
189 | static void dax_region_free(struct kref *kref) |
190 | { | |
191 | struct dax_region *dax_region; | |
192 | ||
193 | dax_region = container_of(kref, struct dax_region, kref); | |
194 | kfree(dax_region); | |
195 | } | |
196 | ||
197 | void dax_region_put(struct dax_region *dax_region) | |
ab68f262 | 198 | { |
ab68f262 | 199 | kref_put(&dax_region->kref, dax_region_free); |
ab68f262 | 200 | } |
ab68f262 | 201 | EXPORT_SYMBOL_GPL(dax_region_put); |
ab68f262 DW |
202 | |
203 | struct dax_region *alloc_dax_region(struct device *parent, int region_id, | |
204 | struct resource *res, unsigned int align, void *addr, | |
205 | unsigned long pfn_flags) | |
206 | { | |
207 | struct dax_region *dax_region; | |
208 | ||
9d2d01a0 DW |
209 | if (!IS_ALIGNED(res->start, align) |
210 | || !IS_ALIGNED(resource_size(res), align)) | |
211 | return NULL; | |
ab68f262 | 212 | |
9d2d01a0 | 213 | dax_region = kzalloc(sizeof(*dax_region), GFP_KERNEL); |
ab68f262 DW |
214 | if (!dax_region) |
215 | return NULL; | |
216 | ||
217 | memcpy(&dax_region->res, res, sizeof(*res)); | |
218 | dax_region->pfn_flags = pfn_flags; | |
219 | kref_init(&dax_region->kref); | |
220 | dax_region->id = region_id; | |
221 | ida_init(&dax_region->ida); | |
222 | dax_region->align = align; | |
223 | dax_region->dev = parent; | |
224 | dax_region->base = addr; | |
225 | ||
226 | return dax_region; | |
227 | } | |
228 | EXPORT_SYMBOL_GPL(alloc_dax_region); | |
229 | ||
ebd84d72 DW |
230 | static struct dax_dev *to_dax_dev(struct device *dev) |
231 | { | |
232 | return container_of(dev, struct dax_dev, dev); | |
233 | } | |
234 | ||
ab68f262 DW |
235 | static ssize_t size_show(struct device *dev, |
236 | struct device_attribute *attr, char *buf) | |
237 | { | |
ebd84d72 | 238 | struct dax_dev *dax_dev = to_dax_dev(dev); |
ab68f262 DW |
239 | unsigned long long size = 0; |
240 | int i; | |
241 | ||
242 | for (i = 0; i < dax_dev->num_resources; i++) | |
243 | size += resource_size(&dax_dev->res[i]); | |
244 | ||
245 | return sprintf(buf, "%llu\n", size); | |
246 | } | |
247 | static DEVICE_ATTR_RO(size); | |
248 | ||
249 | static struct attribute *dax_device_attributes[] = { | |
250 | &dev_attr_size.attr, | |
251 | NULL, | |
252 | }; | |
253 | ||
254 | static const struct attribute_group dax_device_attribute_group = { | |
255 | .attrs = dax_device_attributes, | |
256 | }; | |
257 | ||
258 | static const struct attribute_group *dax_attribute_groups[] = { | |
259 | &dax_device_attribute_group, | |
260 | NULL, | |
261 | }; | |
262 | ||
dee41079 DW |
263 | static int check_vma(struct dax_dev *dax_dev, struct vm_area_struct *vma, |
264 | const char *func) | |
265 | { | |
266 | struct dax_region *dax_region = dax_dev->region; | |
ebd84d72 | 267 | struct device *dev = &dax_dev->dev; |
dee41079 DW |
268 | unsigned long mask; |
269 | ||
270 | if (!dax_dev->alive) | |
271 | return -ENXIO; | |
272 | ||
4cb19355 | 273 | /* prevent private mappings from being established */ |
325896ff | 274 | if ((vma->vm_flags & VM_MAYSHARE) != VM_MAYSHARE) { |
dee41079 DW |
275 | dev_info(dev, "%s: %s: fail, attempted private mapping\n", |
276 | current->comm, func); | |
277 | return -EINVAL; | |
278 | } | |
279 | ||
280 | mask = dax_region->align - 1; | |
281 | if (vma->vm_start & mask || vma->vm_end & mask) { | |
282 | dev_info(dev, "%s: %s: fail, unaligned vma (%#lx - %#lx, %#lx)\n", | |
283 | current->comm, func, vma->vm_start, vma->vm_end, | |
284 | mask); | |
285 | return -EINVAL; | |
286 | } | |
287 | ||
288 | if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) == PFN_DEV | |
289 | && (vma->vm_flags & VM_DONTCOPY) == 0) { | |
290 | dev_info(dev, "%s: %s: fail, dax range requires MADV_DONTFORK\n", | |
291 | current->comm, func); | |
292 | return -EINVAL; | |
293 | } | |
294 | ||
295 | if (!vma_is_dax(vma)) { | |
296 | dev_info(dev, "%s: %s: fail, vma is not DAX capable\n", | |
297 | current->comm, func); | |
298 | return -EINVAL; | |
299 | } | |
300 | ||
301 | return 0; | |
302 | } | |
303 | ||
304 | static phys_addr_t pgoff_to_phys(struct dax_dev *dax_dev, pgoff_t pgoff, | |
305 | unsigned long size) | |
306 | { | |
307 | struct resource *res; | |
308 | phys_addr_t phys; | |
309 | int i; | |
310 | ||
311 | for (i = 0; i < dax_dev->num_resources; i++) { | |
312 | res = &dax_dev->res[i]; | |
313 | phys = pgoff * PAGE_SIZE + res->start; | |
314 | if (phys >= res->start && phys <= res->end) | |
315 | break; | |
316 | pgoff -= PHYS_PFN(resource_size(res)); | |
317 | } | |
318 | ||
319 | if (i < dax_dev->num_resources) { | |
320 | res = &dax_dev->res[i]; | |
321 | if (phys + size - 1 <= res->end) | |
322 | return phys; | |
323 | } | |
324 | ||
325 | return -1; | |
326 | } | |
327 | ||
328 | static int __dax_dev_fault(struct dax_dev *dax_dev, struct vm_area_struct *vma, | |
329 | struct vm_fault *vmf) | |
330 | { | |
ebd84d72 | 331 | struct device *dev = &dax_dev->dev; |
dee41079 DW |
332 | struct dax_region *dax_region; |
333 | int rc = VM_FAULT_SIGBUS; | |
334 | phys_addr_t phys; | |
335 | pfn_t pfn; | |
336 | ||
337 | if (check_vma(dax_dev, vma, __func__)) | |
338 | return VM_FAULT_SIGBUS; | |
339 | ||
340 | dax_region = dax_dev->region; | |
341 | if (dax_region->align > PAGE_SIZE) { | |
342 | dev_dbg(dev, "%s: alignment > fault size\n", __func__); | |
343 | return VM_FAULT_SIGBUS; | |
344 | } | |
345 | ||
346 | phys = pgoff_to_phys(dax_dev, vmf->pgoff, PAGE_SIZE); | |
347 | if (phys == -1) { | |
348 | dev_dbg(dev, "%s: phys_to_pgoff(%#lx) failed\n", __func__, | |
349 | vmf->pgoff); | |
350 | return VM_FAULT_SIGBUS; | |
351 | } | |
352 | ||
353 | pfn = phys_to_pfn_t(phys, dax_region->pfn_flags); | |
354 | ||
1a29d85e | 355 | rc = vm_insert_mixed(vma, vmf->address, pfn); |
dee41079 DW |
356 | |
357 | if (rc == -ENOMEM) | |
358 | return VM_FAULT_OOM; | |
359 | if (rc < 0 && rc != -EBUSY) | |
360 | return VM_FAULT_SIGBUS; | |
361 | ||
362 | return VM_FAULT_NOPAGE; | |
363 | } | |
364 | ||
365 | static int dax_dev_fault(struct vm_area_struct *vma, struct vm_fault *vmf) | |
366 | { | |
367 | int rc; | |
368 | struct file *filp = vma->vm_file; | |
369 | struct dax_dev *dax_dev = filp->private_data; | |
370 | ||
ebd84d72 | 371 | dev_dbg(&dax_dev->dev, "%s: %s: %s (%#lx - %#lx)\n", __func__, |
dee41079 DW |
372 | current->comm, (vmf->flags & FAULT_FLAG_WRITE) |
373 | ? "write" : "read", vma->vm_start, vma->vm_end); | |
374 | rcu_read_lock(); | |
375 | rc = __dax_dev_fault(dax_dev, vma, vmf); | |
376 | rcu_read_unlock(); | |
377 | ||
378 | return rc; | |
379 | } | |
380 | ||
381 | static int __dax_dev_pmd_fault(struct dax_dev *dax_dev, | |
382 | struct vm_area_struct *vma, unsigned long addr, pmd_t *pmd, | |
383 | unsigned int flags) | |
384 | { | |
385 | unsigned long pmd_addr = addr & PMD_MASK; | |
ebd84d72 | 386 | struct device *dev = &dax_dev->dev; |
dee41079 DW |
387 | struct dax_region *dax_region; |
388 | phys_addr_t phys; | |
389 | pgoff_t pgoff; | |
390 | pfn_t pfn; | |
391 | ||
392 | if (check_vma(dax_dev, vma, __func__)) | |
393 | return VM_FAULT_SIGBUS; | |
394 | ||
395 | dax_region = dax_dev->region; | |
396 | if (dax_region->align > PMD_SIZE) { | |
397 | dev_dbg(dev, "%s: alignment > fault size\n", __func__); | |
398 | return VM_FAULT_SIGBUS; | |
399 | } | |
400 | ||
401 | /* dax pmd mappings require pfn_t_devmap() */ | |
402 | if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) != (PFN_DEV|PFN_MAP)) { | |
403 | dev_dbg(dev, "%s: alignment > fault size\n", __func__); | |
404 | return VM_FAULT_SIGBUS; | |
405 | } | |
406 | ||
407 | pgoff = linear_page_index(vma, pmd_addr); | |
4c3cb6e9 | 408 | phys = pgoff_to_phys(dax_dev, pgoff, PMD_SIZE); |
dee41079 DW |
409 | if (phys == -1) { |
410 | dev_dbg(dev, "%s: phys_to_pgoff(%#lx) failed\n", __func__, | |
411 | pgoff); | |
412 | return VM_FAULT_SIGBUS; | |
413 | } | |
414 | ||
415 | pfn = phys_to_pfn_t(phys, dax_region->pfn_flags); | |
416 | ||
417 | return vmf_insert_pfn_pmd(vma, addr, pmd, pfn, | |
418 | flags & FAULT_FLAG_WRITE); | |
419 | } | |
420 | ||
421 | static int dax_dev_pmd_fault(struct vm_area_struct *vma, unsigned long addr, | |
422 | pmd_t *pmd, unsigned int flags) | |
423 | { | |
424 | int rc; | |
425 | struct file *filp = vma->vm_file; | |
426 | struct dax_dev *dax_dev = filp->private_data; | |
427 | ||
ebd84d72 | 428 | dev_dbg(&dax_dev->dev, "%s: %s: %s (%#lx - %#lx)\n", __func__, |
dee41079 DW |
429 | current->comm, (flags & FAULT_FLAG_WRITE) |
430 | ? "write" : "read", vma->vm_start, vma->vm_end); | |
431 | ||
432 | rcu_read_lock(); | |
433 | rc = __dax_dev_pmd_fault(dax_dev, vma, addr, pmd, flags); | |
434 | rcu_read_unlock(); | |
435 | ||
436 | return rc; | |
437 | } | |
438 | ||
dee41079 DW |
439 | static const struct vm_operations_struct dax_dev_vm_ops = { |
440 | .fault = dax_dev_fault, | |
441 | .pmd_fault = dax_dev_pmd_fault, | |
dee41079 DW |
442 | }; |
443 | ||
af69f51e | 444 | static int dax_mmap(struct file *filp, struct vm_area_struct *vma) |
dee41079 DW |
445 | { |
446 | struct dax_dev *dax_dev = filp->private_data; | |
447 | int rc; | |
448 | ||
ebd84d72 | 449 | dev_dbg(&dax_dev->dev, "%s\n", __func__); |
dee41079 DW |
450 | |
451 | rc = check_vma(dax_dev, vma, __func__); | |
452 | if (rc) | |
453 | return rc; | |
454 | ||
dee41079 DW |
455 | vma->vm_ops = &dax_dev_vm_ops; |
456 | vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE; | |
457 | return 0; | |
043a9255 DW |
458 | } |
459 | ||
460 | /* return an unmapped area aligned to the dax region specified alignment */ | |
af69f51e | 461 | static unsigned long dax_get_unmapped_area(struct file *filp, |
043a9255 DW |
462 | unsigned long addr, unsigned long len, unsigned long pgoff, |
463 | unsigned long flags) | |
464 | { | |
465 | unsigned long off, off_end, off_align, len_align, addr_align, align; | |
466 | struct dax_dev *dax_dev = filp ? filp->private_data : NULL; | |
467 | struct dax_region *dax_region; | |
468 | ||
469 | if (!dax_dev || addr) | |
470 | goto out; | |
471 | ||
472 | dax_region = dax_dev->region; | |
473 | align = dax_region->align; | |
474 | off = pgoff << PAGE_SHIFT; | |
475 | off_end = off + len; | |
476 | off_align = round_up(off, align); | |
477 | ||
478 | if ((off_end <= off_align) || ((off_end - off_align) < align)) | |
479 | goto out; | |
480 | ||
481 | len_align = len + align; | |
482 | if ((off + len_align) < off) | |
483 | goto out; | |
dee41079 | 484 | |
043a9255 DW |
485 | addr_align = current->mm->get_unmapped_area(filp, addr, len_align, |
486 | pgoff, flags); | |
487 | if (!IS_ERR_VALUE(addr_align)) { | |
488 | addr_align += (off - addr_align) & (align - 1); | |
489 | return addr_align; | |
490 | } | |
491 | out: | |
492 | return current->mm->get_unmapped_area(filp, addr, len, pgoff, flags); | |
493 | } | |
494 | ||
af69f51e | 495 | static int dax_open(struct inode *inode, struct file *filp) |
043a9255 | 496 | { |
ba09c01d | 497 | struct dax_dev *dax_dev; |
043a9255 | 498 | |
ba09c01d DW |
499 | dax_dev = container_of(inode->i_cdev, struct dax_dev, cdev); |
500 | dev_dbg(&dax_dev->dev, "%s\n", __func__); | |
3bc52c45 DW |
501 | inode->i_mapping = dax_dev->inode->i_mapping; |
502 | inode->i_mapping->host = dax_dev->inode; | |
503 | filp->f_mapping = inode->i_mapping; | |
ebd84d72 DW |
504 | filp->private_data = dax_dev; |
505 | inode->i_flags = S_DAX; | |
043a9255 | 506 | |
043a9255 DW |
507 | return 0; |
508 | } | |
dee41079 | 509 | |
af69f51e | 510 | static int dax_release(struct inode *inode, struct file *filp) |
043a9255 DW |
511 | { |
512 | struct dax_dev *dax_dev = filp->private_data; | |
043a9255 | 513 | |
ba09c01d | 514 | dev_dbg(&dax_dev->dev, "%s\n", __func__); |
043a9255 | 515 | return 0; |
dee41079 DW |
516 | } |
517 | ||
ab68f262 DW |
518 | static const struct file_operations dax_fops = { |
519 | .llseek = noop_llseek, | |
520 | .owner = THIS_MODULE, | |
af69f51e DW |
521 | .open = dax_open, |
522 | .release = dax_release, | |
523 | .get_unmapped_area = dax_get_unmapped_area, | |
524 | .mmap = dax_mmap, | |
ab68f262 DW |
525 | }; |
526 | ||
ebd84d72 | 527 | static void dax_dev_release(struct device *dev) |
043a9255 | 528 | { |
ebd84d72 | 529 | struct dax_dev *dax_dev = to_dax_dev(dev); |
043a9255 DW |
530 | struct dax_region *dax_region = dax_dev->region; |
531 | ||
ebd84d72 DW |
532 | ida_simple_remove(&dax_region->ida, dax_dev->id); |
533 | ida_simple_remove(&dax_minor_ida, MINOR(dev->devt)); | |
534 | dax_region_put(dax_region); | |
3bc52c45 | 535 | iput(dax_dev->inode); |
ebd84d72 DW |
536 | kfree(dax_dev); |
537 | } | |
538 | ||
539 | static void unregister_dax_dev(void *dev) | |
540 | { | |
541 | struct dax_dev *dax_dev = to_dax_dev(dev); | |
ba09c01d | 542 | struct cdev *cdev = &dax_dev->cdev; |
ebd84d72 | 543 | |
043a9255 DW |
544 | dev_dbg(dev, "%s\n", __func__); |
545 | ||
546 | /* | |
547 | * Note, rcu is not protecting the liveness of dax_dev, rcu is | |
548 | * ensuring that any fault handlers that might have seen | |
549 | * dax_dev->alive == true, have completed. Any fault handlers | |
550 | * that start after synchronize_rcu() has started will abort | |
551 | * upon seeing dax_dev->alive == false. | |
552 | */ | |
553 | dax_dev->alive = false; | |
554 | synchronize_rcu(); | |
9dc1e492 | 555 | unmap_mapping_range(dax_dev->inode->i_mapping, 0, 0, 1); |
ba09c01d | 556 | cdev_del(cdev); |
043a9255 | 557 | device_unregister(dev); |
043a9255 DW |
558 | } |
559 | ||
d76911ee DW |
560 | struct dax_dev *devm_create_dax_dev(struct dax_region *dax_region, |
561 | struct resource *res, int count) | |
043a9255 DW |
562 | { |
563 | struct device *parent = dax_region->dev; | |
564 | struct dax_dev *dax_dev; | |
9d2d01a0 | 565 | int rc = 0, minor, i; |
043a9255 | 566 | struct device *dev; |
ba09c01d | 567 | struct cdev *cdev; |
043a9255 DW |
568 | dev_t dev_t; |
569 | ||
570 | dax_dev = kzalloc(sizeof(*dax_dev) + sizeof(*res) * count, GFP_KERNEL); | |
571 | if (!dax_dev) | |
d76911ee | 572 | return ERR_PTR(-ENOMEM); |
043a9255 | 573 | |
9d2d01a0 DW |
574 | for (i = 0; i < count; i++) { |
575 | if (!IS_ALIGNED(res[i].start, dax_region->align) | |
576 | || !IS_ALIGNED(resource_size(&res[i]), | |
577 | dax_region->align)) { | |
578 | rc = -EINVAL; | |
579 | break; | |
580 | } | |
581 | dax_dev->res[i].start = res[i].start; | |
582 | dax_dev->res[i].end = res[i].end; | |
583 | } | |
584 | ||
585 | if (i < count) | |
586 | goto err_id; | |
587 | ||
043a9255 DW |
588 | dax_dev->id = ida_simple_get(&dax_region->ida, 0, 0, GFP_KERNEL); |
589 | if (dax_dev->id < 0) { | |
590 | rc = dax_dev->id; | |
591 | goto err_id; | |
592 | } | |
593 | ||
594 | minor = ida_simple_get(&dax_minor_ida, 0, 0, GFP_KERNEL); | |
595 | if (minor < 0) { | |
596 | rc = minor; | |
597 | goto err_minor; | |
598 | } | |
599 | ||
bc0a0fe9 AB |
600 | dev_t = MKDEV(MAJOR(dax_devt), minor); |
601 | dev = &dax_dev->dev; | |
3bc52c45 DW |
602 | dax_dev->inode = dax_inode_get(&dax_dev->cdev, dev_t); |
603 | if (!dax_dev->inode) { | |
604 | rc = -ENOMEM; | |
605 | goto err_inode; | |
606 | } | |
607 | ||
ba09c01d | 608 | /* device_initialize() so cdev can reference kobj parent */ |
ebd84d72 | 609 | device_initialize(dev); |
ba09c01d DW |
610 | |
611 | cdev = &dax_dev->cdev; | |
612 | cdev_init(cdev, &dax_fops); | |
613 | cdev->owner = parent->driver->owner; | |
614 | cdev->kobj.parent = &dev->kobj; | |
615 | rc = cdev_add(&dax_dev->cdev, dev_t, 1); | |
616 | if (rc) | |
617 | goto err_cdev; | |
618 | ||
619 | /* from here on we're committed to teardown via dax_dev_release() */ | |
ba09c01d DW |
620 | dax_dev->num_resources = count; |
621 | dax_dev->alive = true; | |
622 | dax_dev->region = dax_region; | |
623 | kref_get(&dax_region->kref); | |
624 | ||
ebd84d72 DW |
625 | dev->devt = dev_t; |
626 | dev->class = dax_class; | |
627 | dev->parent = parent; | |
628 | dev->groups = dax_attribute_groups; | |
629 | dev->release = dax_dev_release; | |
630 | dev_set_name(dev, "dax%d.%d", dax_region->id, dax_dev->id); | |
631 | rc = device_add(dev); | |
632 | if (rc) { | |
633 | put_device(dev); | |
d76911ee | 634 | return ERR_PTR(rc); |
ebd84d72 | 635 | } |
043a9255 | 636 | |
d76911ee DW |
637 | rc = devm_add_action_or_reset(dax_region->dev, unregister_dax_dev, dev); |
638 | if (rc) | |
639 | return ERR_PTR(rc); | |
640 | ||
641 | return dax_dev; | |
043a9255 | 642 | |
ba09c01d | 643 | err_cdev: |
3bc52c45 DW |
644 | iput(dax_dev->inode); |
645 | err_inode: | |
ba09c01d | 646 | ida_simple_remove(&dax_minor_ida, minor); |
043a9255 DW |
647 | err_minor: |
648 | ida_simple_remove(&dax_region->ida, dax_dev->id); | |
649 | err_id: | |
ebd84d72 | 650 | kfree(dax_dev); |
043a9255 | 651 | |
d76911ee | 652 | return ERR_PTR(rc); |
043a9255 DW |
653 | } |
654 | EXPORT_SYMBOL_GPL(devm_create_dax_dev); | |
655 | ||
ab68f262 DW |
656 | static int __init dax_init(void) |
657 | { | |
658 | int rc; | |
659 | ||
3bc52c45 DW |
660 | rc = dax_inode_init(); |
661 | if (rc) | |
ab68f262 | 662 | return rc; |
3bc52c45 | 663 | |
ba09c01d DW |
664 | nr_dax = max(nr_dax, 256); |
665 | rc = alloc_chrdev_region(&dax_devt, 0, nr_dax, "dax"); | |
666 | if (rc) | |
3bc52c45 | 667 | goto err_chrdev; |
ab68f262 DW |
668 | |
669 | dax_class = class_create(THIS_MODULE, "dax"); | |
670 | if (IS_ERR(dax_class)) { | |
3bc52c45 DW |
671 | rc = PTR_ERR(dax_class); |
672 | goto err_class; | |
ab68f262 DW |
673 | } |
674 | ||
675 | return 0; | |
3bc52c45 DW |
676 | |
677 | err_class: | |
678 | unregister_chrdev_region(dax_devt, nr_dax); | |
679 | err_chrdev: | |
680 | dax_inode_exit(); | |
681 | return rc; | |
ab68f262 DW |
682 | } |
683 | ||
684 | static void __exit dax_exit(void) | |
685 | { | |
686 | class_destroy(dax_class); | |
ba09c01d | 687 | unregister_chrdev_region(dax_devt, nr_dax); |
ab68f262 | 688 | ida_destroy(&dax_minor_ida); |
3bc52c45 | 689 | dax_inode_exit(); |
ab68f262 DW |
690 | } |
691 | ||
692 | MODULE_AUTHOR("Intel Corporation"); | |
693 | MODULE_LICENSE("GPL v2"); | |
694 | subsys_initcall(dax_init); | |
695 | module_exit(dax_exit); |