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ab68f262 | 1 | /* |
7b6be844 | 2 | * Copyright(c) 2016 - 2017 Intel Corporation. All rights reserved. |
ab68f262 DW |
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> | |
ba09c01d | 17 | #include <linux/cdev.h> |
ab68f262 DW |
18 | #include <linux/slab.h> |
19 | #include <linux/dax.h> | |
20 | #include <linux/fs.h> | |
21 | #include <linux/mm.h> | |
323fc460 | 22 | #include <linux/mman.h> |
efebc711 | 23 | #include "dax-private.h" |
ccdb07f6 | 24 | #include "dax.h" |
ab68f262 | 25 | |
ab68f262 | 26 | static struct class *dax_class; |
ab68f262 | 27 | |
565851c9 DW |
28 | /* |
29 | * Rely on the fact that drvdata is set before the attributes are | |
30 | * registered, and that the attributes are unregistered before drvdata | |
31 | * is cleared to assume that drvdata is always valid. | |
32 | */ | |
d7fe1a67 DW |
33 | static ssize_t id_show(struct device *dev, |
34 | struct device_attribute *attr, char *buf) | |
35 | { | |
565851c9 | 36 | struct dax_region *dax_region = dev_get_drvdata(dev); |
d7fe1a67 | 37 | |
565851c9 | 38 | return sprintf(buf, "%d\n", dax_region->id); |
d7fe1a67 DW |
39 | } |
40 | static DEVICE_ATTR_RO(id); | |
41 | ||
42 | static ssize_t region_size_show(struct device *dev, | |
43 | struct device_attribute *attr, char *buf) | |
44 | { | |
565851c9 | 45 | struct dax_region *dax_region = dev_get_drvdata(dev); |
d7fe1a67 | 46 | |
565851c9 DW |
47 | return sprintf(buf, "%llu\n", (unsigned long long) |
48 | resource_size(&dax_region->res)); | |
d7fe1a67 DW |
49 | } |
50 | static struct device_attribute dev_attr_region_size = __ATTR(size, 0444, | |
51 | region_size_show, NULL); | |
52 | ||
53 | static ssize_t align_show(struct device *dev, | |
54 | struct device_attribute *attr, char *buf) | |
55 | { | |
565851c9 | 56 | struct dax_region *dax_region = dev_get_drvdata(dev); |
d7fe1a67 | 57 | |
565851c9 | 58 | return sprintf(buf, "%u\n", dax_region->align); |
d7fe1a67 DW |
59 | } |
60 | static DEVICE_ATTR_RO(align); | |
61 | ||
62 | static struct attribute *dax_region_attributes[] = { | |
63 | &dev_attr_region_size.attr, | |
64 | &dev_attr_align.attr, | |
65 | &dev_attr_id.attr, | |
66 | NULL, | |
67 | }; | |
68 | ||
69 | static const struct attribute_group dax_region_attribute_group = { | |
70 | .name = "dax_region", | |
71 | .attrs = dax_region_attributes, | |
72 | }; | |
73 | ||
74 | static const struct attribute_group *dax_region_attribute_groups[] = { | |
75 | &dax_region_attribute_group, | |
76 | NULL, | |
77 | }; | |
78 | ||
ab68f262 DW |
79 | static void dax_region_free(struct kref *kref) |
80 | { | |
81 | struct dax_region *dax_region; | |
82 | ||
83 | dax_region = container_of(kref, struct dax_region, kref); | |
84 | kfree(dax_region); | |
85 | } | |
86 | ||
87 | void dax_region_put(struct dax_region *dax_region) | |
ab68f262 | 88 | { |
ab68f262 | 89 | kref_put(&dax_region->kref, dax_region_free); |
ab68f262 | 90 | } |
ab68f262 | 91 | EXPORT_SYMBOL_GPL(dax_region_put); |
ab68f262 | 92 | |
d7fe1a67 DW |
93 | static void dax_region_unregister(void *region) |
94 | { | |
95 | struct dax_region *dax_region = region; | |
96 | ||
97 | sysfs_remove_groups(&dax_region->dev->kobj, | |
98 | dax_region_attribute_groups); | |
99 | dax_region_put(dax_region); | |
100 | } | |
101 | ||
ab68f262 DW |
102 | struct dax_region *alloc_dax_region(struct device *parent, int region_id, |
103 | struct resource *res, unsigned int align, void *addr, | |
104 | unsigned long pfn_flags) | |
105 | { | |
106 | struct dax_region *dax_region; | |
107 | ||
d7fe1a67 DW |
108 | /* |
109 | * The DAX core assumes that it can store its private data in | |
110 | * parent->driver_data. This WARN is a reminder / safeguard for | |
111 | * developers of device-dax drivers. | |
112 | */ | |
113 | if (dev_get_drvdata(parent)) { | |
114 | dev_WARN(parent, "dax core failed to setup private data\n"); | |
115 | return NULL; | |
116 | } | |
117 | ||
9d2d01a0 DW |
118 | if (!IS_ALIGNED(res->start, align) |
119 | || !IS_ALIGNED(resource_size(res), align)) | |
120 | return NULL; | |
ab68f262 | 121 | |
9d2d01a0 | 122 | dax_region = kzalloc(sizeof(*dax_region), GFP_KERNEL); |
ab68f262 DW |
123 | if (!dax_region) |
124 | return NULL; | |
125 | ||
d7fe1a67 | 126 | dev_set_drvdata(parent, dax_region); |
ab68f262 DW |
127 | memcpy(&dax_region->res, res, sizeof(*res)); |
128 | dax_region->pfn_flags = pfn_flags; | |
129 | kref_init(&dax_region->kref); | |
130 | dax_region->id = region_id; | |
131 | ida_init(&dax_region->ida); | |
132 | dax_region->align = align; | |
133 | dax_region->dev = parent; | |
134 | dax_region->base = addr; | |
d7fe1a67 DW |
135 | if (sysfs_create_groups(&parent->kobj, dax_region_attribute_groups)) { |
136 | kfree(dax_region); | |
137 | return NULL;; | |
138 | } | |
ab68f262 | 139 | |
d7fe1a67 DW |
140 | kref_get(&dax_region->kref); |
141 | if (devm_add_action_or_reset(parent, dax_region_unregister, dax_region)) | |
142 | return NULL; | |
ab68f262 DW |
143 | return dax_region; |
144 | } | |
145 | EXPORT_SYMBOL_GPL(alloc_dax_region); | |
146 | ||
5f0694b3 | 147 | static struct dev_dax *to_dev_dax(struct device *dev) |
ebd84d72 | 148 | { |
5f0694b3 | 149 | return container_of(dev, struct dev_dax, dev); |
ebd84d72 DW |
150 | } |
151 | ||
ab68f262 DW |
152 | static ssize_t size_show(struct device *dev, |
153 | struct device_attribute *attr, char *buf) | |
154 | { | |
5f0694b3 | 155 | struct dev_dax *dev_dax = to_dev_dax(dev); |
ab68f262 DW |
156 | unsigned long long size = 0; |
157 | int i; | |
158 | ||
5f0694b3 DW |
159 | for (i = 0; i < dev_dax->num_resources; i++) |
160 | size += resource_size(&dev_dax->res[i]); | |
ab68f262 DW |
161 | |
162 | return sprintf(buf, "%llu\n", size); | |
163 | } | |
164 | static DEVICE_ATTR_RO(size); | |
165 | ||
5f0694b3 | 166 | static struct attribute *dev_dax_attributes[] = { |
ab68f262 DW |
167 | &dev_attr_size.attr, |
168 | NULL, | |
169 | }; | |
170 | ||
5f0694b3 DW |
171 | static const struct attribute_group dev_dax_attribute_group = { |
172 | .attrs = dev_dax_attributes, | |
ab68f262 DW |
173 | }; |
174 | ||
175 | static const struct attribute_group *dax_attribute_groups[] = { | |
5f0694b3 | 176 | &dev_dax_attribute_group, |
ab68f262 DW |
177 | NULL, |
178 | }; | |
179 | ||
5f0694b3 | 180 | static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma, |
dee41079 DW |
181 | const char *func) |
182 | { | |
5f0694b3 DW |
183 | struct dax_region *dax_region = dev_dax->region; |
184 | struct device *dev = &dev_dax->dev; | |
dee41079 DW |
185 | unsigned long mask; |
186 | ||
7b6be844 | 187 | if (!dax_alive(dev_dax->dax_dev)) |
dee41079 DW |
188 | return -ENXIO; |
189 | ||
4cb19355 | 190 | /* prevent private mappings from being established */ |
325896ff | 191 | if ((vma->vm_flags & VM_MAYSHARE) != VM_MAYSHARE) { |
ba73bad7 JM |
192 | dev_info_ratelimited(dev, |
193 | "%s: %s: fail, attempted private mapping\n", | |
dee41079 DW |
194 | current->comm, func); |
195 | return -EINVAL; | |
196 | } | |
197 | ||
198 | mask = dax_region->align - 1; | |
199 | if (vma->vm_start & mask || vma->vm_end & mask) { | |
ba73bad7 JM |
200 | dev_info_ratelimited(dev, |
201 | "%s: %s: fail, unaligned vma (%#lx - %#lx, %#lx)\n", | |
dee41079 DW |
202 | current->comm, func, vma->vm_start, vma->vm_end, |
203 | mask); | |
204 | return -EINVAL; | |
205 | } | |
206 | ||
207 | if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) == PFN_DEV | |
208 | && (vma->vm_flags & VM_DONTCOPY) == 0) { | |
ba73bad7 JM |
209 | dev_info_ratelimited(dev, |
210 | "%s: %s: fail, dax range requires MADV_DONTFORK\n", | |
dee41079 DW |
211 | current->comm, func); |
212 | return -EINVAL; | |
213 | } | |
214 | ||
215 | if (!vma_is_dax(vma)) { | |
ba73bad7 JM |
216 | dev_info_ratelimited(dev, |
217 | "%s: %s: fail, vma is not DAX capable\n", | |
dee41079 DW |
218 | current->comm, func); |
219 | return -EINVAL; | |
220 | } | |
221 | ||
222 | return 0; | |
223 | } | |
224 | ||
efebc711 | 225 | /* see "strong" declaration in tools/testing/nvdimm/dax-dev.c */ |
73616367 | 226 | __weak phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff, |
dee41079 DW |
227 | unsigned long size) |
228 | { | |
229 | struct resource *res; | |
0a3ff786 RZ |
230 | /* gcc-4.6.3-nolibc for i386 complains that this is uninitialized */ |
231 | phys_addr_t uninitialized_var(phys); | |
dee41079 DW |
232 | int i; |
233 | ||
5f0694b3 DW |
234 | for (i = 0; i < dev_dax->num_resources; i++) { |
235 | res = &dev_dax->res[i]; | |
dee41079 DW |
236 | phys = pgoff * PAGE_SIZE + res->start; |
237 | if (phys >= res->start && phys <= res->end) | |
238 | break; | |
239 | pgoff -= PHYS_PFN(resource_size(res)); | |
240 | } | |
241 | ||
5f0694b3 DW |
242 | if (i < dev_dax->num_resources) { |
243 | res = &dev_dax->res[i]; | |
dee41079 DW |
244 | if (phys + size - 1 <= res->end) |
245 | return phys; | |
246 | } | |
247 | ||
248 | return -1; | |
249 | } | |
250 | ||
5f0694b3 | 251 | static int __dev_dax_pte_fault(struct dev_dax *dev_dax, struct vm_fault *vmf) |
dee41079 | 252 | { |
5f0694b3 | 253 | struct device *dev = &dev_dax->dev; |
dee41079 DW |
254 | struct dax_region *dax_region; |
255 | int rc = VM_FAULT_SIGBUS; | |
256 | phys_addr_t phys; | |
257 | pfn_t pfn; | |
0134ed4f | 258 | unsigned int fault_size = PAGE_SIZE; |
dee41079 | 259 | |
5f0694b3 | 260 | if (check_vma(dev_dax, vmf->vma, __func__)) |
dee41079 DW |
261 | return VM_FAULT_SIGBUS; |
262 | ||
5f0694b3 | 263 | dax_region = dev_dax->region; |
dee41079 | 264 | if (dax_region->align > PAGE_SIZE) { |
76202620 OH |
265 | dev_dbg(dev, "%s: alignment (%#x) > fault size (%#x)\n", |
266 | __func__, dax_region->align, fault_size); | |
dee41079 DW |
267 | return VM_FAULT_SIGBUS; |
268 | } | |
269 | ||
0134ed4f DJ |
270 | if (fault_size != dax_region->align) |
271 | return VM_FAULT_SIGBUS; | |
272 | ||
73616367 | 273 | phys = dax_pgoff_to_phys(dev_dax, vmf->pgoff, PAGE_SIZE); |
dee41079 | 274 | if (phys == -1) { |
52084f89 | 275 | dev_dbg(dev, "%s: pgoff_to_phys(%#lx) failed\n", __func__, |
dee41079 DW |
276 | vmf->pgoff); |
277 | return VM_FAULT_SIGBUS; | |
278 | } | |
279 | ||
280 | pfn = phys_to_pfn_t(phys, dax_region->pfn_flags); | |
281 | ||
11bac800 | 282 | rc = vm_insert_mixed(vmf->vma, vmf->address, pfn); |
dee41079 DW |
283 | |
284 | if (rc == -ENOMEM) | |
285 | return VM_FAULT_OOM; | |
286 | if (rc < 0 && rc != -EBUSY) | |
287 | return VM_FAULT_SIGBUS; | |
288 | ||
289 | return VM_FAULT_NOPAGE; | |
290 | } | |
291 | ||
5f0694b3 | 292 | static int __dev_dax_pmd_fault(struct dev_dax *dev_dax, struct vm_fault *vmf) |
dee41079 | 293 | { |
d8a849e1 | 294 | unsigned long pmd_addr = vmf->address & PMD_MASK; |
5f0694b3 | 295 | struct device *dev = &dev_dax->dev; |
dee41079 DW |
296 | struct dax_region *dax_region; |
297 | phys_addr_t phys; | |
298 | pgoff_t pgoff; | |
299 | pfn_t pfn; | |
0134ed4f | 300 | unsigned int fault_size = PMD_SIZE; |
dee41079 | 301 | |
5f0694b3 | 302 | if (check_vma(dev_dax, vmf->vma, __func__)) |
dee41079 DW |
303 | return VM_FAULT_SIGBUS; |
304 | ||
5f0694b3 | 305 | dax_region = dev_dax->region; |
dee41079 | 306 | if (dax_region->align > PMD_SIZE) { |
76202620 OH |
307 | dev_dbg(dev, "%s: alignment (%#x) > fault size (%#x)\n", |
308 | __func__, dax_region->align, fault_size); | |
dee41079 DW |
309 | return VM_FAULT_SIGBUS; |
310 | } | |
311 | ||
312 | /* dax pmd mappings require pfn_t_devmap() */ | |
313 | if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) != (PFN_DEV|PFN_MAP)) { | |
76202620 | 314 | dev_dbg(dev, "%s: region lacks devmap flags\n", __func__); |
dee41079 DW |
315 | return VM_FAULT_SIGBUS; |
316 | } | |
317 | ||
0134ed4f DJ |
318 | if (fault_size < dax_region->align) |
319 | return VM_FAULT_SIGBUS; | |
320 | else if (fault_size > dax_region->align) | |
321 | return VM_FAULT_FALLBACK; | |
322 | ||
323 | /* if we are outside of the VMA */ | |
324 | if (pmd_addr < vmf->vma->vm_start || | |
325 | (pmd_addr + PMD_SIZE) > vmf->vma->vm_end) | |
326 | return VM_FAULT_SIGBUS; | |
327 | ||
f4200391 | 328 | pgoff = linear_page_index(vmf->vma, pmd_addr); |
73616367 | 329 | phys = dax_pgoff_to_phys(dev_dax, pgoff, PMD_SIZE); |
dee41079 | 330 | if (phys == -1) { |
52084f89 | 331 | dev_dbg(dev, "%s: pgoff_to_phys(%#lx) failed\n", __func__, |
dee41079 DW |
332 | pgoff); |
333 | return VM_FAULT_SIGBUS; | |
334 | } | |
335 | ||
336 | pfn = phys_to_pfn_t(phys, dax_region->pfn_flags); | |
337 | ||
f4200391 | 338 | return vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd, pfn, |
d8a849e1 | 339 | vmf->flags & FAULT_FLAG_WRITE); |
dee41079 DW |
340 | } |
341 | ||
9557feee | 342 | #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD |
5f0694b3 | 343 | static int __dev_dax_pud_fault(struct dev_dax *dev_dax, struct vm_fault *vmf) |
9557feee DJ |
344 | { |
345 | unsigned long pud_addr = vmf->address & PUD_MASK; | |
5f0694b3 | 346 | struct device *dev = &dev_dax->dev; |
9557feee DJ |
347 | struct dax_region *dax_region; |
348 | phys_addr_t phys; | |
349 | pgoff_t pgoff; | |
350 | pfn_t pfn; | |
70b085b0 DJ |
351 | unsigned int fault_size = PUD_SIZE; |
352 | ||
9557feee | 353 | |
5f0694b3 | 354 | if (check_vma(dev_dax, vmf->vma, __func__)) |
9557feee DJ |
355 | return VM_FAULT_SIGBUS; |
356 | ||
5f0694b3 | 357 | dax_region = dev_dax->region; |
9557feee | 358 | if (dax_region->align > PUD_SIZE) { |
76202620 OH |
359 | dev_dbg(dev, "%s: alignment (%#x) > fault size (%#x)\n", |
360 | __func__, dax_region->align, fault_size); | |
9557feee DJ |
361 | return VM_FAULT_SIGBUS; |
362 | } | |
363 | ||
364 | /* dax pud mappings require pfn_t_devmap() */ | |
365 | if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) != (PFN_DEV|PFN_MAP)) { | |
76202620 | 366 | dev_dbg(dev, "%s: region lacks devmap flags\n", __func__); |
9557feee DJ |
367 | return VM_FAULT_SIGBUS; |
368 | } | |
369 | ||
70b085b0 DJ |
370 | if (fault_size < dax_region->align) |
371 | return VM_FAULT_SIGBUS; | |
372 | else if (fault_size > dax_region->align) | |
373 | return VM_FAULT_FALLBACK; | |
374 | ||
375 | /* if we are outside of the VMA */ | |
376 | if (pud_addr < vmf->vma->vm_start || | |
377 | (pud_addr + PUD_SIZE) > vmf->vma->vm_end) | |
378 | return VM_FAULT_SIGBUS; | |
379 | ||
9557feee | 380 | pgoff = linear_page_index(vmf->vma, pud_addr); |
73616367 | 381 | phys = dax_pgoff_to_phys(dev_dax, pgoff, PUD_SIZE); |
9557feee | 382 | if (phys == -1) { |
52084f89 | 383 | dev_dbg(dev, "%s: pgoff_to_phys(%#lx) failed\n", __func__, |
9557feee DJ |
384 | pgoff); |
385 | return VM_FAULT_SIGBUS; | |
386 | } | |
387 | ||
388 | pfn = phys_to_pfn_t(phys, dax_region->pfn_flags); | |
389 | ||
390 | return vmf_insert_pfn_pud(vmf->vma, vmf->address, vmf->pud, pfn, | |
391 | vmf->flags & FAULT_FLAG_WRITE); | |
392 | } | |
393 | #else | |
5f0694b3 | 394 | static int __dev_dax_pud_fault(struct dev_dax *dev_dax, struct vm_fault *vmf) |
9557feee DJ |
395 | { |
396 | return VM_FAULT_FALLBACK; | |
397 | } | |
398 | #endif /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ | |
399 | ||
5f0694b3 | 400 | static int dev_dax_huge_fault(struct vm_fault *vmf, |
c791ace1 | 401 | enum page_entry_size pe_size) |
dee41079 | 402 | { |
956a4cd2 | 403 | int rc, id; |
f4200391 | 404 | struct file *filp = vmf->vma->vm_file; |
5f0694b3 | 405 | struct dev_dax *dev_dax = filp->private_data; |
dee41079 | 406 | |
5f0694b3 | 407 | dev_dbg(&dev_dax->dev, "%s: %s: %s (%#lx - %#lx) size = %d\n", __func__, |
d8a849e1 | 408 | current->comm, (vmf->flags & FAULT_FLAG_WRITE) |
f4200391 | 409 | ? "write" : "read", |
76202620 | 410 | vmf->vma->vm_start, vmf->vma->vm_end, pe_size); |
dee41079 | 411 | |
7b6be844 | 412 | id = dax_read_lock(); |
c791ace1 DJ |
413 | switch (pe_size) { |
414 | case PE_SIZE_PTE: | |
5f0694b3 | 415 | rc = __dev_dax_pte_fault(dev_dax, vmf); |
a2d58167 | 416 | break; |
c791ace1 | 417 | case PE_SIZE_PMD: |
5f0694b3 | 418 | rc = __dev_dax_pmd_fault(dev_dax, vmf); |
9557feee | 419 | break; |
c791ace1 | 420 | case PE_SIZE_PUD: |
5f0694b3 | 421 | rc = __dev_dax_pud_fault(dev_dax, vmf); |
a2d58167 DJ |
422 | break; |
423 | default: | |
54eafcc9 | 424 | rc = VM_FAULT_SIGBUS; |
a2d58167 | 425 | } |
7b6be844 | 426 | dax_read_unlock(id); |
dee41079 DW |
427 | |
428 | return rc; | |
429 | } | |
430 | ||
5f0694b3 | 431 | static int dev_dax_fault(struct vm_fault *vmf) |
c791ace1 | 432 | { |
5f0694b3 | 433 | return dev_dax_huge_fault(vmf, PE_SIZE_PTE); |
c791ace1 DJ |
434 | } |
435 | ||
9702cffd DW |
436 | static int dev_dax_split(struct vm_area_struct *vma, unsigned long addr) |
437 | { | |
438 | struct file *filp = vma->vm_file; | |
439 | struct dev_dax *dev_dax = filp->private_data; | |
440 | struct dax_region *dax_region = dev_dax->region; | |
441 | ||
442 | if (!IS_ALIGNED(addr, dax_region->align)) | |
443 | return -EINVAL; | |
444 | return 0; | |
445 | } | |
446 | ||
5f0694b3 DW |
447 | static const struct vm_operations_struct dax_vm_ops = { |
448 | .fault = dev_dax_fault, | |
449 | .huge_fault = dev_dax_huge_fault, | |
9702cffd | 450 | .split = dev_dax_split, |
dee41079 DW |
451 | }; |
452 | ||
af69f51e | 453 | static int dax_mmap(struct file *filp, struct vm_area_struct *vma) |
dee41079 | 454 | { |
5f0694b3 | 455 | struct dev_dax *dev_dax = filp->private_data; |
7b6be844 | 456 | int rc, id; |
dee41079 | 457 | |
5f0694b3 | 458 | dev_dbg(&dev_dax->dev, "%s\n", __func__); |
dee41079 | 459 | |
7b6be844 DW |
460 | /* |
461 | * We lock to check dax_dev liveness and will re-check at | |
462 | * fault time. | |
463 | */ | |
464 | id = dax_read_lock(); | |
5f0694b3 | 465 | rc = check_vma(dev_dax, vma, __func__); |
7b6be844 | 466 | dax_read_unlock(id); |
dee41079 DW |
467 | if (rc) |
468 | return rc; | |
469 | ||
5f0694b3 | 470 | vma->vm_ops = &dax_vm_ops; |
dee41079 DW |
471 | vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE; |
472 | return 0; | |
043a9255 DW |
473 | } |
474 | ||
475 | /* return an unmapped area aligned to the dax region specified alignment */ | |
af69f51e | 476 | static unsigned long dax_get_unmapped_area(struct file *filp, |
043a9255 DW |
477 | unsigned long addr, unsigned long len, unsigned long pgoff, |
478 | unsigned long flags) | |
479 | { | |
480 | unsigned long off, off_end, off_align, len_align, addr_align, align; | |
5f0694b3 | 481 | struct dev_dax *dev_dax = filp ? filp->private_data : NULL; |
043a9255 DW |
482 | struct dax_region *dax_region; |
483 | ||
5f0694b3 | 484 | if (!dev_dax || addr) |
043a9255 DW |
485 | goto out; |
486 | ||
5f0694b3 | 487 | dax_region = dev_dax->region; |
043a9255 DW |
488 | align = dax_region->align; |
489 | off = pgoff << PAGE_SHIFT; | |
490 | off_end = off + len; | |
491 | off_align = round_up(off, align); | |
492 | ||
493 | if ((off_end <= off_align) || ((off_end - off_align) < align)) | |
494 | goto out; | |
495 | ||
496 | len_align = len + align; | |
497 | if ((off + len_align) < off) | |
498 | goto out; | |
dee41079 | 499 | |
043a9255 DW |
500 | addr_align = current->mm->get_unmapped_area(filp, addr, len_align, |
501 | pgoff, flags); | |
502 | if (!IS_ERR_VALUE(addr_align)) { | |
503 | addr_align += (off - addr_align) & (align - 1); | |
504 | return addr_align; | |
505 | } | |
506 | out: | |
507 | return current->mm->get_unmapped_area(filp, addr, len, pgoff, flags); | |
508 | } | |
509 | ||
af69f51e | 510 | static int dax_open(struct inode *inode, struct file *filp) |
043a9255 | 511 | { |
7b6be844 DW |
512 | struct dax_device *dax_dev = inode_dax(inode); |
513 | struct inode *__dax_inode = dax_inode(dax_dev); | |
514 | struct dev_dax *dev_dax = dax_get_private(dax_dev); | |
043a9255 | 515 | |
5f0694b3 | 516 | dev_dbg(&dev_dax->dev, "%s\n", __func__); |
7b6be844 DW |
517 | inode->i_mapping = __dax_inode->i_mapping; |
518 | inode->i_mapping->host = __dax_inode; | |
3bc52c45 | 519 | filp->f_mapping = inode->i_mapping; |
5660e13d | 520 | filp->f_wb_err = filemap_sample_wb_err(filp->f_mapping); |
5f0694b3 | 521 | filp->private_data = dev_dax; |
ebd84d72 | 522 | inode->i_flags = S_DAX; |
043a9255 | 523 | |
043a9255 DW |
524 | return 0; |
525 | } | |
dee41079 | 526 | |
af69f51e | 527 | static int dax_release(struct inode *inode, struct file *filp) |
043a9255 | 528 | { |
5f0694b3 | 529 | struct dev_dax *dev_dax = filp->private_data; |
043a9255 | 530 | |
5f0694b3 | 531 | dev_dbg(&dev_dax->dev, "%s\n", __func__); |
043a9255 | 532 | return 0; |
dee41079 DW |
533 | } |
534 | ||
ab68f262 DW |
535 | static const struct file_operations dax_fops = { |
536 | .llseek = noop_llseek, | |
537 | .owner = THIS_MODULE, | |
af69f51e DW |
538 | .open = dax_open, |
539 | .release = dax_release, | |
540 | .get_unmapped_area = dax_get_unmapped_area, | |
541 | .mmap = dax_mmap, | |
323fc460 | 542 | .mmap_supported_flags = MAP_SYNC, |
ab68f262 DW |
543 | }; |
544 | ||
5f0694b3 | 545 | static void dev_dax_release(struct device *dev) |
043a9255 | 546 | { |
5f0694b3 DW |
547 | struct dev_dax *dev_dax = to_dev_dax(dev); |
548 | struct dax_region *dax_region = dev_dax->region; | |
7b6be844 | 549 | struct dax_device *dax_dev = dev_dax->dax_dev; |
043a9255 | 550 | |
bbb3be17 DW |
551 | if (dev_dax->id >= 0) |
552 | ida_simple_remove(&dax_region->ida, dev_dax->id); | |
ebd84d72 | 553 | dax_region_put(dax_region); |
7b6be844 | 554 | put_dax(dax_dev); |
5f0694b3 | 555 | kfree(dev_dax); |
ebd84d72 DW |
556 | } |
557 | ||
5f0694b3 | 558 | static void kill_dev_dax(struct dev_dax *dev_dax) |
ebd84d72 | 559 | { |
7b6be844 DW |
560 | struct dax_device *dax_dev = dev_dax->dax_dev; |
561 | struct inode *inode = dax_inode(dax_dev); | |
562 | ||
563 | kill_dax(dax_dev); | |
564 | unmap_mapping_range(inode->i_mapping, 0, 0, 1); | |
ebd84d72 DW |
565 | } |
566 | ||
5f0694b3 | 567 | static void unregister_dev_dax(void *dev) |
ebd84d72 | 568 | { |
5f0694b3 | 569 | struct dev_dax *dev_dax = to_dev_dax(dev); |
7b6be844 DW |
570 | struct dax_device *dax_dev = dev_dax->dax_dev; |
571 | struct inode *inode = dax_inode(dax_dev); | |
572 | struct cdev *cdev = inode->i_cdev; | |
ebd84d72 | 573 | |
043a9255 DW |
574 | dev_dbg(dev, "%s\n", __func__); |
575 | ||
5f0694b3 | 576 | kill_dev_dax(dev_dax); |
7b6be844 | 577 | cdev_device_del(cdev, dev); |
92a3fa07 | 578 | put_device(dev); |
043a9255 DW |
579 | } |
580 | ||
5f0694b3 | 581 | struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, |
bbb3be17 | 582 | int id, struct resource *res, int count) |
043a9255 DW |
583 | { |
584 | struct device *parent = dax_region->dev; | |
7b6be844 | 585 | struct dax_device *dax_dev; |
5f0694b3 | 586 | struct dev_dax *dev_dax; |
7b6be844 | 587 | struct inode *inode; |
043a9255 | 588 | struct device *dev; |
ba09c01d | 589 | struct cdev *cdev; |
43fe51e1 DW |
590 | int rc, i; |
591 | ||
592 | if (!count) | |
593 | return ERR_PTR(-EINVAL); | |
043a9255 | 594 | |
5f0694b3 DW |
595 | dev_dax = kzalloc(sizeof(*dev_dax) + sizeof(*res) * count, GFP_KERNEL); |
596 | if (!dev_dax) | |
d76911ee | 597 | return ERR_PTR(-ENOMEM); |
043a9255 | 598 | |
9d2d01a0 DW |
599 | for (i = 0; i < count; i++) { |
600 | if (!IS_ALIGNED(res[i].start, dax_region->align) | |
601 | || !IS_ALIGNED(resource_size(&res[i]), | |
602 | dax_region->align)) { | |
603 | rc = -EINVAL; | |
604 | break; | |
605 | } | |
5f0694b3 DW |
606 | dev_dax->res[i].start = res[i].start; |
607 | dev_dax->res[i].end = res[i].end; | |
9d2d01a0 DW |
608 | } |
609 | ||
610 | if (i < count) | |
611 | goto err_id; | |
612 | ||
bbb3be17 DW |
613 | if (id < 0) { |
614 | id = ida_simple_get(&dax_region->ida, 0, 0, GFP_KERNEL); | |
615 | dev_dax->id = id; | |
616 | if (id < 0) { | |
617 | rc = id; | |
618 | goto err_id; | |
619 | } | |
620 | } else { | |
621 | /* region provider owns @id lifetime */ | |
622 | dev_dax->id = -1; | |
043a9255 DW |
623 | } |
624 | ||
6568b08b DW |
625 | /* |
626 | * No 'host' or dax_operations since there is no access to this | |
627 | * device outside of mmap of the resulting character device. | |
628 | */ | |
629 | dax_dev = alloc_dax(dev_dax, NULL, NULL); | |
43fe51e1 DW |
630 | if (!dax_dev) { |
631 | rc = -ENOMEM; | |
7b6be844 | 632 | goto err_dax; |
43fe51e1 | 633 | } |
3bc52c45 | 634 | |
7b6be844 | 635 | /* from here on we're committed to teardown via dax_dev_release() */ |
5f0694b3 | 636 | dev = &dev_dax->dev; |
ebd84d72 | 637 | device_initialize(dev); |
ba09c01d | 638 | |
7b6be844 DW |
639 | inode = dax_inode(dax_dev); |
640 | cdev = inode->i_cdev; | |
ba09c01d DW |
641 | cdev_init(cdev, &dax_fops); |
642 | cdev->owner = parent->driver->owner; | |
ba09c01d | 643 | |
5f0694b3 | 644 | dev_dax->num_resources = count; |
7b6be844 | 645 | dev_dax->dax_dev = dax_dev; |
5f0694b3 | 646 | dev_dax->region = dax_region; |
ba09c01d DW |
647 | kref_get(&dax_region->kref); |
648 | ||
7b6be844 | 649 | dev->devt = inode->i_rdev; |
ebd84d72 DW |
650 | dev->class = dax_class; |
651 | dev->parent = parent; | |
652 | dev->groups = dax_attribute_groups; | |
5f0694b3 | 653 | dev->release = dev_dax_release; |
bbb3be17 | 654 | dev_set_name(dev, "dax%d.%d", dax_region->id, id); |
92a3fa07 LG |
655 | |
656 | rc = cdev_device_add(cdev, dev); | |
ebd84d72 | 657 | if (rc) { |
5f0694b3 | 658 | kill_dev_dax(dev_dax); |
ebd84d72 | 659 | put_device(dev); |
d76911ee | 660 | return ERR_PTR(rc); |
ebd84d72 | 661 | } |
043a9255 | 662 | |
5f0694b3 | 663 | rc = devm_add_action_or_reset(dax_region->dev, unregister_dev_dax, dev); |
d76911ee DW |
664 | if (rc) |
665 | return ERR_PTR(rc); | |
666 | ||
5f0694b3 | 667 | return dev_dax; |
043a9255 | 668 | |
7b6be844 | 669 | err_dax: |
bbb3be17 DW |
670 | if (dev_dax->id >= 0) |
671 | ida_simple_remove(&dax_region->ida, dev_dax->id); | |
043a9255 | 672 | err_id: |
5f0694b3 | 673 | kfree(dev_dax); |
043a9255 | 674 | |
d76911ee | 675 | return ERR_PTR(rc); |
043a9255 | 676 | } |
5f0694b3 | 677 | EXPORT_SYMBOL_GPL(devm_create_dev_dax); |
043a9255 | 678 | |
ab68f262 DW |
679 | static int __init dax_init(void) |
680 | { | |
ab68f262 | 681 | dax_class = class_create(THIS_MODULE, "dax"); |
7b6be844 | 682 | return PTR_ERR_OR_ZERO(dax_class); |
ab68f262 DW |
683 | } |
684 | ||
685 | static void __exit dax_exit(void) | |
686 | { | |
687 | class_destroy(dax_class); | |
ab68f262 DW |
688 | } |
689 | ||
690 | MODULE_AUTHOR("Intel Corporation"); | |
691 | MODULE_LICENSE("GPL v2"); | |
692 | subsys_initcall(dax_init); | |
693 | module_exit(dax_exit); |