1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * linux/kernel/resource.c |
4 | * |
5 | * Copyright (C) 1999 Linus Torvalds |
6 | * Copyright (C) 1999 Martin Mares <mj@ucw.cz> |
7 | * |
8 | * Arbitrary resource management. |
9 | */ |
10 | |
11 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
12 | |
13 | #include <linux/export.h> |
14 | #include <linux/errno.h> |
15 | #include <linux/ioport.h> |
16 | #include <linux/init.h> |
17 | #include <linux/slab.h> |
18 | #include <linux/spinlock.h> |
19 | #include <linux/fs.h> |
20 | #include <linux/proc_fs.h> |
21 | #include <linux/pseudo_fs.h> |
22 | #include <linux/sched.h> |
23 | #include <linux/seq_file.h> |
24 | #include <linux/device.h> |
25 | #include <linux/pfn.h> |
26 | #include <linux/mm.h> |
27 | #include <linux/mount.h> |
28 | #include <linux/resource_ext.h> |
29 | #include <uapi/linux/magic.h> |
30 | #include <asm/io.h> |
31 | |
32 | |
33 | struct resource ioport_resource = { |
34 | .name = "PCI IO" , |
35 | .start = 0, |
36 | .end = IO_SPACE_LIMIT, |
37 | .flags = IORESOURCE_IO, |
38 | }; |
39 | EXPORT_SYMBOL(ioport_resource); |
40 | |
41 | struct resource iomem_resource = { |
42 | .name = "PCI mem" , |
43 | .start = 0, |
44 | .end = -1, |
45 | .flags = IORESOURCE_MEM, |
46 | }; |
47 | EXPORT_SYMBOL(iomem_resource); |
48 | |
49 | /* constraints to be met while allocating resources */ |
50 | struct resource_constraint { |
51 | resource_size_t min, max, align; |
52 | resource_size_t (*alignf)(void *, const struct resource *, |
53 | resource_size_t, resource_size_t); |
54 | void *alignf_data; |
55 | }; |
56 | |
57 | static DEFINE_RWLOCK(resource_lock); |
58 | |
59 | static struct resource *next_resource(struct resource *p, bool skip_children) |
60 | { |
61 | if (!skip_children && p->child) |
62 | return p->child; |
63 | while (!p->sibling && p->parent) |
64 | p = p->parent; |
65 | return p->sibling; |
66 | } |
67 | |
68 | #define for_each_resource(_root, _p, _skip_children) \ |
69 | for ((_p) = (_root)->child; (_p); (_p) = next_resource(_p, _skip_children)) |
70 | |
71 | #ifdef CONFIG_PROC_FS |
72 | |
73 | enum { MAX_IORES_LEVEL = 5 }; |
74 | |
75 | static void *r_start(struct seq_file *m, loff_t *pos) |
76 | __acquires(resource_lock) |
77 | { |
78 | struct resource *root = pde_data(inode: file_inode(f: m->file)); |
79 | struct resource *p; |
80 | loff_t l = *pos; |
81 | |
82 | read_lock(&resource_lock); |
83 | for_each_resource(root, p, false) { |
84 | if (l-- == 0) |
85 | break; |
86 | } |
87 | |
88 | return p; |
89 | } |
90 | |
91 | static void *r_next(struct seq_file *m, void *v, loff_t *pos) |
92 | { |
93 | struct resource *p = v; |
94 | |
95 | (*pos)++; |
96 | |
97 | return (void *)next_resource(p, skip_children: false); |
98 | } |
99 | |
100 | static void r_stop(struct seq_file *m, void *v) |
101 | __releases(resource_lock) |
102 | { |
103 | read_unlock(&resource_lock); |
104 | } |
105 | |
106 | static int r_show(struct seq_file *m, void *v) |
107 | { |
108 | struct resource *root = pde_data(inode: file_inode(f: m->file)); |
109 | struct resource *r = v, *p; |
110 | unsigned long long start, end; |
111 | int width = root->end < 0x10000 ? 4 : 8; |
112 | int depth; |
113 | |
114 | for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent) |
115 | if (p->parent == root) |
116 | break; |
117 | |
118 | if (file_ns_capable(file: m->file, ns: &init_user_ns, CAP_SYS_ADMIN)) { |
119 | start = r->start; |
120 | end = r->end; |
121 | } else { |
122 | start = end = 0; |
123 | } |
124 | |
125 | seq_printf(m, fmt: "%*s%0*llx-%0*llx : %s\n" , |
126 | depth * 2, "" , |
127 | width, start, |
128 | width, end, |
129 | r->name ? r->name : "<BAD>" ); |
130 | return 0; |
131 | } |
132 | |
133 | static const struct seq_operations resource_op = { |
134 | .start = r_start, |
135 | .next = r_next, |
136 | .stop = r_stop, |
137 | .show = r_show, |
138 | }; |
139 | |
140 | static int __init ioresources_init(void) |
141 | { |
142 | proc_create_seq_data("ioports" , 0, NULL, &resource_op, |
143 | &ioport_resource); |
144 | proc_create_seq_data("iomem" , 0, NULL, &resource_op, &iomem_resource); |
145 | return 0; |
146 | } |
147 | __initcall(ioresources_init); |
148 | |
149 | #endif /* CONFIG_PROC_FS */ |
150 | |
151 | static void free_resource(struct resource *res) |
152 | { |
153 | /** |
154 | * If the resource was allocated using memblock early during boot |
155 | * we'll leak it here: we can only return full pages back to the |
156 | * buddy and trying to be smart and reusing them eventually in |
157 | * alloc_resource() overcomplicates resource handling. |
158 | */ |
159 | if (res && PageSlab(page: virt_to_head_page(x: res))) |
160 | kfree(objp: res); |
161 | } |
162 | |
163 | static struct resource *alloc_resource(gfp_t flags) |
164 | { |
165 | return kzalloc(size: sizeof(struct resource), flags); |
166 | } |
167 | |
168 | /* Return the conflict entry if you can't request it */ |
169 | static struct resource * __request_resource(struct resource *root, struct resource *new) |
170 | { |
171 | resource_size_t start = new->start; |
172 | resource_size_t end = new->end; |
173 | struct resource *tmp, **p; |
174 | |
175 | if (end < start) |
176 | return root; |
177 | if (start < root->start) |
178 | return root; |
179 | if (end > root->end) |
180 | return root; |
181 | p = &root->child; |
182 | for (;;) { |
183 | tmp = *p; |
184 | if (!tmp || tmp->start > end) { |
185 | new->sibling = tmp; |
186 | *p = new; |
187 | new->parent = root; |
188 | return NULL; |
189 | } |
190 | p = &tmp->sibling; |
191 | if (tmp->end < start) |
192 | continue; |
193 | return tmp; |
194 | } |
195 | } |
196 | |
197 | static int __release_resource(struct resource *old, bool release_child) |
198 | { |
199 | struct resource *tmp, **p, *chd; |
200 | |
201 | p = &old->parent->child; |
202 | for (;;) { |
203 | tmp = *p; |
204 | if (!tmp) |
205 | break; |
206 | if (tmp == old) { |
207 | if (release_child || !(tmp->child)) { |
208 | *p = tmp->sibling; |
209 | } else { |
210 | for (chd = tmp->child;; chd = chd->sibling) { |
211 | chd->parent = tmp->parent; |
212 | if (!(chd->sibling)) |
213 | break; |
214 | } |
215 | *p = tmp->child; |
216 | chd->sibling = tmp->sibling; |
217 | } |
218 | old->parent = NULL; |
219 | return 0; |
220 | } |
221 | p = &tmp->sibling; |
222 | } |
223 | return -EINVAL; |
224 | } |
225 | |
226 | static void __release_child_resources(struct resource *r) |
227 | { |
228 | struct resource *tmp, *p; |
229 | resource_size_t size; |
230 | |
231 | p = r->child; |
232 | r->child = NULL; |
233 | while (p) { |
234 | tmp = p; |
235 | p = p->sibling; |
236 | |
237 | tmp->parent = NULL; |
238 | tmp->sibling = NULL; |
239 | __release_child_resources(r: tmp); |
240 | |
241 | printk(KERN_DEBUG "release child resource %pR\n" , tmp); |
242 | /* need to restore size, and keep flags */ |
243 | size = resource_size(res: tmp); |
244 | tmp->start = 0; |
245 | tmp->end = size - 1; |
246 | } |
247 | } |
248 | |
249 | void release_child_resources(struct resource *r) |
250 | { |
251 | write_lock(&resource_lock); |
252 | __release_child_resources(r); |
253 | write_unlock(&resource_lock); |
254 | } |
255 | |
256 | /** |
257 | * request_resource_conflict - request and reserve an I/O or memory resource |
258 | * @root: root resource descriptor |
259 | * @new: resource descriptor desired by caller |
260 | * |
261 | * Returns 0 for success, conflict resource on error. |
262 | */ |
263 | struct resource *request_resource_conflict(struct resource *root, struct resource *new) |
264 | { |
265 | struct resource *conflict; |
266 | |
267 | write_lock(&resource_lock); |
268 | conflict = __request_resource(root, new); |
269 | write_unlock(&resource_lock); |
270 | return conflict; |
271 | } |
272 | |
273 | /** |
274 | * request_resource - request and reserve an I/O or memory resource |
275 | * @root: root resource descriptor |
276 | * @new: resource descriptor desired by caller |
277 | * |
278 | * Returns 0 for success, negative error code on error. |
279 | */ |
280 | int request_resource(struct resource *root, struct resource *new) |
281 | { |
282 | struct resource *conflict; |
283 | |
284 | conflict = request_resource_conflict(root, new); |
285 | return conflict ? -EBUSY : 0; |
286 | } |
287 | |
288 | EXPORT_SYMBOL(request_resource); |
289 | |
290 | /** |
291 | * release_resource - release a previously reserved resource |
292 | * @old: resource pointer |
293 | */ |
294 | int release_resource(struct resource *old) |
295 | { |
296 | int retval; |
297 | |
298 | write_lock(&resource_lock); |
299 | retval = __release_resource(old, release_child: true); |
300 | write_unlock(&resource_lock); |
301 | return retval; |
302 | } |
303 | |
304 | EXPORT_SYMBOL(release_resource); |
305 | |
306 | /** |
307 | * find_next_iomem_res - Finds the lowest iomem resource that covers part of |
308 | * [@start..@end]. |
309 | * |
310 | * If a resource is found, returns 0 and @*res is overwritten with the part |
311 | * of the resource that's within [@start..@end]; if none is found, returns |
312 | * -ENODEV. Returns -EINVAL for invalid parameters. |
313 | * |
314 | * @start: start address of the resource searched for |
315 | * @end: end address of same resource |
316 | * @flags: flags which the resource must have |
317 | * @desc: descriptor the resource must have |
318 | * @res: return ptr, if resource found |
319 | * |
320 | * The caller must specify @start, @end, @flags, and @desc |
321 | * (which may be IORES_DESC_NONE). |
322 | */ |
323 | static int find_next_iomem_res(resource_size_t start, resource_size_t end, |
324 | unsigned long flags, unsigned long desc, |
325 | struct resource *res) |
326 | { |
327 | struct resource *p; |
328 | |
329 | if (!res) |
330 | return -EINVAL; |
331 | |
332 | if (start >= end) |
333 | return -EINVAL; |
334 | |
335 | read_lock(&resource_lock); |
336 | |
337 | for_each_resource(&iomem_resource, p, false) { |
338 | /* If we passed the resource we are looking for, stop */ |
339 | if (p->start > end) { |
340 | p = NULL; |
341 | break; |
342 | } |
343 | |
344 | /* Skip until we find a range that matches what we look for */ |
345 | if (p->end < start) |
346 | continue; |
347 | |
348 | if ((p->flags & flags) != flags) |
349 | continue; |
350 | if ((desc != IORES_DESC_NONE) && (desc != p->desc)) |
351 | continue; |
352 | |
353 | /* Found a match, break */ |
354 | break; |
355 | } |
356 | |
357 | if (p) { |
358 | /* copy data */ |
359 | *res = (struct resource) { |
360 | .start = max(start, p->start), |
361 | .end = min(end, p->end), |
362 | .flags = p->flags, |
363 | .desc = p->desc, |
364 | .parent = p->parent, |
365 | }; |
366 | } |
367 | |
368 | read_unlock(&resource_lock); |
369 | return p ? 0 : -ENODEV; |
370 | } |
371 | |
372 | static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end, |
373 | unsigned long flags, unsigned long desc, |
374 | void *arg, |
375 | int (*func)(struct resource *, void *)) |
376 | { |
377 | struct resource res; |
378 | int ret = -EINVAL; |
379 | |
380 | while (start < end && |
381 | !find_next_iomem_res(start, end, flags, desc, res: &res)) { |
382 | ret = (*func)(&res, arg); |
383 | if (ret) |
384 | break; |
385 | |
386 | start = res.end + 1; |
387 | } |
388 | |
389 | return ret; |
390 | } |
391 | |
392 | /** |
393 | * walk_iomem_res_desc - Walks through iomem resources and calls func() |
394 | * with matching resource ranges. |
395 | * * |
396 | * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check. |
397 | * @flags: I/O resource flags |
398 | * @start: start addr |
399 | * @end: end addr |
400 | * @arg: function argument for the callback @func |
401 | * @func: callback function that is called for each qualifying resource area |
402 | * |
403 | * All the memory ranges which overlap start,end and also match flags and |
404 | * desc are valid candidates. |
405 | * |
406 | * NOTE: For a new descriptor search, define a new IORES_DESC in |
407 | * <linux/ioport.h> and set it in 'desc' of a target resource entry. |
408 | */ |
409 | int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start, |
410 | u64 end, void *arg, int (*func)(struct resource *, void *)) |
411 | { |
412 | return __walk_iomem_res_desc(start, end, flags, desc, arg, func); |
413 | } |
414 | EXPORT_SYMBOL_GPL(walk_iomem_res_desc); |
415 | |
416 | /* |
417 | * This function calls the @func callback against all memory ranges of type |
418 | * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY. |
419 | * Now, this function is only for System RAM, it deals with full ranges and |
420 | * not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate |
421 | * ranges. |
422 | */ |
423 | int walk_system_ram_res(u64 start, u64 end, void *arg, |
424 | int (*func)(struct resource *, void *)) |
425 | { |
426 | unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; |
427 | |
428 | return __walk_iomem_res_desc(start, end, flags, desc: IORES_DESC_NONE, arg, |
429 | func); |
430 | } |
431 | |
432 | /* |
433 | * This function calls the @func callback against all memory ranges, which |
434 | * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY. |
435 | */ |
436 | int walk_mem_res(u64 start, u64 end, void *arg, |
437 | int (*func)(struct resource *, void *)) |
438 | { |
439 | unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY; |
440 | |
441 | return __walk_iomem_res_desc(start, end, flags, desc: IORES_DESC_NONE, arg, |
442 | func); |
443 | } |
444 | |
445 | /* |
446 | * This function calls the @func callback against all memory ranges of type |
447 | * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY. |
448 | * It is to be used only for System RAM. |
449 | */ |
450 | int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages, |
451 | void *arg, int (*func)(unsigned long, unsigned long, void *)) |
452 | { |
453 | resource_size_t start, end; |
454 | unsigned long flags; |
455 | struct resource res; |
456 | unsigned long pfn, end_pfn; |
457 | int ret = -EINVAL; |
458 | |
459 | start = (u64) start_pfn << PAGE_SHIFT; |
460 | end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1; |
461 | flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; |
462 | while (start < end && |
463 | !find_next_iomem_res(start, end, flags, desc: IORES_DESC_NONE, res: &res)) { |
464 | pfn = PFN_UP(res.start); |
465 | end_pfn = PFN_DOWN(res.end + 1); |
466 | if (end_pfn > pfn) |
467 | ret = (*func)(pfn, end_pfn - pfn, arg); |
468 | if (ret) |
469 | break; |
470 | start = res.end + 1; |
471 | } |
472 | return ret; |
473 | } |
474 | |
475 | static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg) |
476 | { |
477 | return 1; |
478 | } |
479 | |
480 | /* |
481 | * This generic page_is_ram() returns true if specified address is |
482 | * registered as System RAM in iomem_resource list. |
483 | */ |
484 | int __weak page_is_ram(unsigned long pfn) |
485 | { |
486 | return walk_system_ram_range(start_pfn: pfn, nr_pages: 1, NULL, func: __is_ram) == 1; |
487 | } |
488 | EXPORT_SYMBOL_GPL(page_is_ram); |
489 | |
490 | static int __region_intersects(struct resource *parent, resource_size_t start, |
491 | size_t size, unsigned long flags, |
492 | unsigned long desc) |
493 | { |
494 | struct resource res; |
495 | int type = 0; int other = 0; |
496 | struct resource *p; |
497 | |
498 | res.start = start; |
499 | res.end = start + size - 1; |
500 | |
501 | for (p = parent->child; p ; p = p->sibling) { |
502 | bool is_type = (((p->flags & flags) == flags) && |
503 | ((desc == IORES_DESC_NONE) || |
504 | (desc == p->desc))); |
505 | |
506 | if (resource_overlaps(r1: p, r2: &res)) |
507 | is_type ? type++ : other++; |
508 | } |
509 | |
510 | if (type == 0) |
511 | return REGION_DISJOINT; |
512 | |
513 | if (other == 0) |
514 | return REGION_INTERSECTS; |
515 | |
516 | return REGION_MIXED; |
517 | } |
518 | |
519 | /** |
520 | * region_intersects() - determine intersection of region with known resources |
521 | * @start: region start address |
522 | * @size: size of region |
523 | * @flags: flags of resource (in iomem_resource) |
524 | * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE |
525 | * |
526 | * Check if the specified region partially overlaps or fully eclipses a |
527 | * resource identified by @flags and @desc (optional with IORES_DESC_NONE). |
528 | * Return REGION_DISJOINT if the region does not overlap @flags/@desc, |
529 | * return REGION_MIXED if the region overlaps @flags/@desc and another |
530 | * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc |
531 | * and no other defined resource. Note that REGION_INTERSECTS is also |
532 | * returned in the case when the specified region overlaps RAM and undefined |
533 | * memory holes. |
534 | * |
535 | * region_intersect() is used by memory remapping functions to ensure |
536 | * the user is not remapping RAM and is a vast speed up over walking |
537 | * through the resource table page by page. |
538 | */ |
539 | int region_intersects(resource_size_t start, size_t size, unsigned long flags, |
540 | unsigned long desc) |
541 | { |
542 | int ret; |
543 | |
544 | read_lock(&resource_lock); |
545 | ret = __region_intersects(parent: &iomem_resource, start, size, flags, desc); |
546 | read_unlock(&resource_lock); |
547 | |
548 | return ret; |
549 | } |
550 | EXPORT_SYMBOL_GPL(region_intersects); |
551 | |
552 | void __weak arch_remove_reservations(struct resource *avail) |
553 | { |
554 | } |
555 | |
556 | static resource_size_t simple_align_resource(void *data, |
557 | const struct resource *avail, |
558 | resource_size_t size, |
559 | resource_size_t align) |
560 | { |
561 | return avail->start; |
562 | } |
563 | |
564 | static void resource_clip(struct resource *res, resource_size_t min, |
565 | resource_size_t max) |
566 | { |
567 | if (res->start < min) |
568 | res->start = min; |
569 | if (res->end > max) |
570 | res->end = max; |
571 | } |
572 | |
573 | /* |
574 | * Find empty slot in the resource tree with the given range and |
575 | * alignment constraints |
576 | */ |
577 | static int __find_resource(struct resource *root, struct resource *old, |
578 | struct resource *new, |
579 | resource_size_t size, |
580 | struct resource_constraint *constraint) |
581 | { |
582 | struct resource *this = root->child; |
583 | struct resource tmp = *new, avail, alloc; |
584 | |
585 | tmp.start = root->start; |
586 | /* |
587 | * Skip past an allocated resource that starts at 0, since the assignment |
588 | * of this->start - 1 to tmp->end below would cause an underflow. |
589 | */ |
590 | if (this && this->start == root->start) { |
591 | tmp.start = (this == old) ? old->start : this->end + 1; |
592 | this = this->sibling; |
593 | } |
594 | for(;;) { |
595 | if (this) |
596 | tmp.end = (this == old) ? this->end : this->start - 1; |
597 | else |
598 | tmp.end = root->end; |
599 | |
600 | if (tmp.end < tmp.start) |
601 | goto next; |
602 | |
603 | resource_clip(res: &tmp, min: constraint->min, max: constraint->max); |
604 | arch_remove_reservations(avail: &tmp); |
605 | |
606 | /* Check for overflow after ALIGN() */ |
607 | avail.start = ALIGN(tmp.start, constraint->align); |
608 | avail.end = tmp.end; |
609 | avail.flags = new->flags & ~IORESOURCE_UNSET; |
610 | if (avail.start >= tmp.start) { |
611 | alloc.flags = avail.flags; |
612 | alloc.start = constraint->alignf(constraint->alignf_data, &avail, |
613 | size, constraint->align); |
614 | alloc.end = alloc.start + size - 1; |
615 | if (alloc.start <= alloc.end && |
616 | resource_contains(r1: &avail, r2: &alloc)) { |
617 | new->start = alloc.start; |
618 | new->end = alloc.end; |
619 | return 0; |
620 | } |
621 | } |
622 | |
623 | next: if (!this || this->end == root->end) |
624 | break; |
625 | |
626 | if (this != old) |
627 | tmp.start = this->end + 1; |
628 | this = this->sibling; |
629 | } |
630 | return -EBUSY; |
631 | } |
632 | |
633 | /* |
634 | * Find empty slot in the resource tree given range and alignment. |
635 | */ |
636 | static int find_resource(struct resource *root, struct resource *new, |
637 | resource_size_t size, |
638 | struct resource_constraint *constraint) |
639 | { |
640 | return __find_resource(root, NULL, new, size, constraint); |
641 | } |
642 | |
643 | /** |
644 | * reallocate_resource - allocate a slot in the resource tree given range & alignment. |
645 | * The resource will be relocated if the new size cannot be reallocated in the |
646 | * current location. |
647 | * |
648 | * @root: root resource descriptor |
649 | * @old: resource descriptor desired by caller |
650 | * @newsize: new size of the resource descriptor |
651 | * @constraint: the size and alignment constraints to be met. |
652 | */ |
653 | static int reallocate_resource(struct resource *root, struct resource *old, |
654 | resource_size_t newsize, |
655 | struct resource_constraint *constraint) |
656 | { |
657 | int err=0; |
658 | struct resource new = *old; |
659 | struct resource *conflict; |
660 | |
661 | write_lock(&resource_lock); |
662 | |
663 | if ((err = __find_resource(root, old, new: &new, size: newsize, constraint))) |
664 | goto out; |
665 | |
666 | if (resource_contains(r1: &new, r2: old)) { |
667 | old->start = new.start; |
668 | old->end = new.end; |
669 | goto out; |
670 | } |
671 | |
672 | if (old->child) { |
673 | err = -EBUSY; |
674 | goto out; |
675 | } |
676 | |
677 | if (resource_contains(r1: old, r2: &new)) { |
678 | old->start = new.start; |
679 | old->end = new.end; |
680 | } else { |
681 | __release_resource(old, release_child: true); |
682 | *old = new; |
683 | conflict = __request_resource(root, new: old); |
684 | BUG_ON(conflict); |
685 | } |
686 | out: |
687 | write_unlock(&resource_lock); |
688 | return err; |
689 | } |
690 | |
691 | |
692 | /** |
693 | * allocate_resource - allocate empty slot in the resource tree given range & alignment. |
694 | * The resource will be reallocated with a new size if it was already allocated |
695 | * @root: root resource descriptor |
696 | * @new: resource descriptor desired by caller |
697 | * @size: requested resource region size |
698 | * @min: minimum boundary to allocate |
699 | * @max: maximum boundary to allocate |
700 | * @align: alignment requested, in bytes |
701 | * @alignf: alignment function, optional, called if not NULL |
702 | * @alignf_data: arbitrary data to pass to the @alignf function |
703 | */ |
704 | int allocate_resource(struct resource *root, struct resource *new, |
705 | resource_size_t size, resource_size_t min, |
706 | resource_size_t max, resource_size_t align, |
707 | resource_size_t (*alignf)(void *, |
708 | const struct resource *, |
709 | resource_size_t, |
710 | resource_size_t), |
711 | void *alignf_data) |
712 | { |
713 | int err; |
714 | struct resource_constraint constraint; |
715 | |
716 | if (!alignf) |
717 | alignf = simple_align_resource; |
718 | |
719 | constraint.min = min; |
720 | constraint.max = max; |
721 | constraint.align = align; |
722 | constraint.alignf = alignf; |
723 | constraint.alignf_data = alignf_data; |
724 | |
725 | if ( new->parent ) { |
726 | /* resource is already allocated, try reallocating with |
727 | the new constraints */ |
728 | return reallocate_resource(root, old: new, newsize: size, constraint: &constraint); |
729 | } |
730 | |
731 | write_lock(&resource_lock); |
732 | err = find_resource(root, new, size, constraint: &constraint); |
733 | if (err >= 0 && __request_resource(root, new)) |
734 | err = -EBUSY; |
735 | write_unlock(&resource_lock); |
736 | return err; |
737 | } |
738 | |
739 | EXPORT_SYMBOL(allocate_resource); |
740 | |
741 | /** |
742 | * lookup_resource - find an existing resource by a resource start address |
743 | * @root: root resource descriptor |
744 | * @start: resource start address |
745 | * |
746 | * Returns a pointer to the resource if found, NULL otherwise |
747 | */ |
748 | struct resource *lookup_resource(struct resource *root, resource_size_t start) |
749 | { |
750 | struct resource *res; |
751 | |
752 | read_lock(&resource_lock); |
753 | for (res = root->child; res; res = res->sibling) { |
754 | if (res->start == start) |
755 | break; |
756 | } |
757 | read_unlock(&resource_lock); |
758 | |
759 | return res; |
760 | } |
761 | |
762 | /* |
763 | * Insert a resource into the resource tree. If successful, return NULL, |
764 | * otherwise return the conflicting resource (compare to __request_resource()) |
765 | */ |
766 | static struct resource * __insert_resource(struct resource *parent, struct resource *new) |
767 | { |
768 | struct resource *first, *next; |
769 | |
770 | for (;; parent = first) { |
771 | first = __request_resource(root: parent, new); |
772 | if (!first) |
773 | return first; |
774 | |
775 | if (first == parent) |
776 | return first; |
777 | if (WARN_ON(first == new)) /* duplicated insertion */ |
778 | return first; |
779 | |
780 | if ((first->start > new->start) || (first->end < new->end)) |
781 | break; |
782 | if ((first->start == new->start) && (first->end == new->end)) |
783 | break; |
784 | } |
785 | |
786 | for (next = first; ; next = next->sibling) { |
787 | /* Partial overlap? Bad, and unfixable */ |
788 | if (next->start < new->start || next->end > new->end) |
789 | return next; |
790 | if (!next->sibling) |
791 | break; |
792 | if (next->sibling->start > new->end) |
793 | break; |
794 | } |
795 | |
796 | new->parent = parent; |
797 | new->sibling = next->sibling; |
798 | new->child = first; |
799 | |
800 | next->sibling = NULL; |
801 | for (next = first; next; next = next->sibling) |
802 | next->parent = new; |
803 | |
804 | if (parent->child == first) { |
805 | parent->child = new; |
806 | } else { |
807 | next = parent->child; |
808 | while (next->sibling != first) |
809 | next = next->sibling; |
810 | next->sibling = new; |
811 | } |
812 | return NULL; |
813 | } |
814 | |
815 | /** |
816 | * insert_resource_conflict - Inserts resource in the resource tree |
817 | * @parent: parent of the new resource |
818 | * @new: new resource to insert |
819 | * |
820 | * Returns 0 on success, conflict resource if the resource can't be inserted. |
821 | * |
822 | * This function is equivalent to request_resource_conflict when no conflict |
823 | * happens. If a conflict happens, and the conflicting resources |
824 | * entirely fit within the range of the new resource, then the new |
825 | * resource is inserted and the conflicting resources become children of |
826 | * the new resource. |
827 | * |
828 | * This function is intended for producers of resources, such as FW modules |
829 | * and bus drivers. |
830 | */ |
831 | struct resource *insert_resource_conflict(struct resource *parent, struct resource *new) |
832 | { |
833 | struct resource *conflict; |
834 | |
835 | write_lock(&resource_lock); |
836 | conflict = __insert_resource(parent, new); |
837 | write_unlock(&resource_lock); |
838 | return conflict; |
839 | } |
840 | |
841 | /** |
842 | * insert_resource - Inserts a resource in the resource tree |
843 | * @parent: parent of the new resource |
844 | * @new: new resource to insert |
845 | * |
846 | * Returns 0 on success, -EBUSY if the resource can't be inserted. |
847 | * |
848 | * This function is intended for producers of resources, such as FW modules |
849 | * and bus drivers. |
850 | */ |
851 | int insert_resource(struct resource *parent, struct resource *new) |
852 | { |
853 | struct resource *conflict; |
854 | |
855 | conflict = insert_resource_conflict(parent, new); |
856 | return conflict ? -EBUSY : 0; |
857 | } |
858 | EXPORT_SYMBOL_GPL(insert_resource); |
859 | |
860 | /** |
861 | * insert_resource_expand_to_fit - Insert a resource into the resource tree |
862 | * @root: root resource descriptor |
863 | * @new: new resource to insert |
864 | * |
865 | * Insert a resource into the resource tree, possibly expanding it in order |
866 | * to make it encompass any conflicting resources. |
867 | */ |
868 | void insert_resource_expand_to_fit(struct resource *root, struct resource *new) |
869 | { |
870 | if (new->parent) |
871 | return; |
872 | |
873 | write_lock(&resource_lock); |
874 | for (;;) { |
875 | struct resource *conflict; |
876 | |
877 | conflict = __insert_resource(parent: root, new); |
878 | if (!conflict) |
879 | break; |
880 | if (conflict == root) |
881 | break; |
882 | |
883 | /* Ok, expand resource to cover the conflict, then try again .. */ |
884 | if (conflict->start < new->start) |
885 | new->start = conflict->start; |
886 | if (conflict->end > new->end) |
887 | new->end = conflict->end; |
888 | |
889 | pr_info("Expanded resource %s due to conflict with %s\n" , new->name, conflict->name); |
890 | } |
891 | write_unlock(&resource_lock); |
892 | } |
893 | /* |
894 | * Not for general consumption, only early boot memory map parsing, PCI |
895 | * resource discovery, and late discovery of CXL resources are expected |
896 | * to use this interface. The former are built-in and only the latter, |
897 | * CXL, is a module. |
898 | */ |
899 | EXPORT_SYMBOL_NS_GPL(insert_resource_expand_to_fit, CXL); |
900 | |
901 | /** |
902 | * remove_resource - Remove a resource in the resource tree |
903 | * @old: resource to remove |
904 | * |
905 | * Returns 0 on success, -EINVAL if the resource is not valid. |
906 | * |
907 | * This function removes a resource previously inserted by insert_resource() |
908 | * or insert_resource_conflict(), and moves the children (if any) up to |
909 | * where they were before. insert_resource() and insert_resource_conflict() |
910 | * insert a new resource, and move any conflicting resources down to the |
911 | * children of the new resource. |
912 | * |
913 | * insert_resource(), insert_resource_conflict() and remove_resource() are |
914 | * intended for producers of resources, such as FW modules and bus drivers. |
915 | */ |
916 | int remove_resource(struct resource *old) |
917 | { |
918 | int retval; |
919 | |
920 | write_lock(&resource_lock); |
921 | retval = __release_resource(old, release_child: false); |
922 | write_unlock(&resource_lock); |
923 | return retval; |
924 | } |
925 | EXPORT_SYMBOL_GPL(remove_resource); |
926 | |
927 | static int __adjust_resource(struct resource *res, resource_size_t start, |
928 | resource_size_t size) |
929 | { |
930 | struct resource *tmp, *parent = res->parent; |
931 | resource_size_t end = start + size - 1; |
932 | int result = -EBUSY; |
933 | |
934 | if (!parent) |
935 | goto skip; |
936 | |
937 | if ((start < parent->start) || (end > parent->end)) |
938 | goto out; |
939 | |
940 | if (res->sibling && (res->sibling->start <= end)) |
941 | goto out; |
942 | |
943 | tmp = parent->child; |
944 | if (tmp != res) { |
945 | while (tmp->sibling != res) |
946 | tmp = tmp->sibling; |
947 | if (start <= tmp->end) |
948 | goto out; |
949 | } |
950 | |
951 | skip: |
952 | for (tmp = res->child; tmp; tmp = tmp->sibling) |
953 | if ((tmp->start < start) || (tmp->end > end)) |
954 | goto out; |
955 | |
956 | res->start = start; |
957 | res->end = end; |
958 | result = 0; |
959 | |
960 | out: |
961 | return result; |
962 | } |
963 | |
964 | /** |
965 | * adjust_resource - modify a resource's start and size |
966 | * @res: resource to modify |
967 | * @start: new start value |
968 | * @size: new size |
969 | * |
970 | * Given an existing resource, change its start and size to match the |
971 | * arguments. Returns 0 on success, -EBUSY if it can't fit. |
972 | * Existing children of the resource are assumed to be immutable. |
973 | */ |
974 | int adjust_resource(struct resource *res, resource_size_t start, |
975 | resource_size_t size) |
976 | { |
977 | int result; |
978 | |
979 | write_lock(&resource_lock); |
980 | result = __adjust_resource(res, start, size); |
981 | write_unlock(&resource_lock); |
982 | return result; |
983 | } |
984 | EXPORT_SYMBOL(adjust_resource); |
985 | |
986 | static void __init |
987 | __reserve_region_with_split(struct resource *root, resource_size_t start, |
988 | resource_size_t end, const char *name) |
989 | { |
990 | struct resource *parent = root; |
991 | struct resource *conflict; |
992 | struct resource *res = alloc_resource(GFP_ATOMIC); |
993 | struct resource *next_res = NULL; |
994 | int type = resource_type(res: root); |
995 | |
996 | if (!res) |
997 | return; |
998 | |
999 | res->name = name; |
1000 | res->start = start; |
1001 | res->end = end; |
1002 | res->flags = type | IORESOURCE_BUSY; |
1003 | res->desc = IORES_DESC_NONE; |
1004 | |
1005 | while (1) { |
1006 | |
1007 | conflict = __request_resource(root: parent, new: res); |
1008 | if (!conflict) { |
1009 | if (!next_res) |
1010 | break; |
1011 | res = next_res; |
1012 | next_res = NULL; |
1013 | continue; |
1014 | } |
1015 | |
1016 | /* conflict covered whole area */ |
1017 | if (conflict->start <= res->start && |
1018 | conflict->end >= res->end) { |
1019 | free_resource(res); |
1020 | WARN_ON(next_res); |
1021 | break; |
1022 | } |
1023 | |
1024 | /* failed, split and try again */ |
1025 | if (conflict->start > res->start) { |
1026 | end = res->end; |
1027 | res->end = conflict->start - 1; |
1028 | if (conflict->end < end) { |
1029 | next_res = alloc_resource(GFP_ATOMIC); |
1030 | if (!next_res) { |
1031 | free_resource(res); |
1032 | break; |
1033 | } |
1034 | next_res->name = name; |
1035 | next_res->start = conflict->end + 1; |
1036 | next_res->end = end; |
1037 | next_res->flags = type | IORESOURCE_BUSY; |
1038 | next_res->desc = IORES_DESC_NONE; |
1039 | } |
1040 | } else { |
1041 | res->start = conflict->end + 1; |
1042 | } |
1043 | } |
1044 | |
1045 | } |
1046 | |
1047 | void __init |
1048 | reserve_region_with_split(struct resource *root, resource_size_t start, |
1049 | resource_size_t end, const char *name) |
1050 | { |
1051 | int abort = 0; |
1052 | |
1053 | write_lock(&resource_lock); |
1054 | if (root->start > start || root->end < end) { |
1055 | pr_err("requested range [0x%llx-0x%llx] not in root %pr\n" , |
1056 | (unsigned long long)start, (unsigned long long)end, |
1057 | root); |
1058 | if (start > root->end || end < root->start) |
1059 | abort = 1; |
1060 | else { |
1061 | if (end > root->end) |
1062 | end = root->end; |
1063 | if (start < root->start) |
1064 | start = root->start; |
1065 | pr_err("fixing request to [0x%llx-0x%llx]\n" , |
1066 | (unsigned long long)start, |
1067 | (unsigned long long)end); |
1068 | } |
1069 | dump_stack(); |
1070 | } |
1071 | if (!abort) |
1072 | __reserve_region_with_split(root, start, end, name); |
1073 | write_unlock(&resource_lock); |
1074 | } |
1075 | |
1076 | /** |
1077 | * resource_alignment - calculate resource's alignment |
1078 | * @res: resource pointer |
1079 | * |
1080 | * Returns alignment on success, 0 (invalid alignment) on failure. |
1081 | */ |
1082 | resource_size_t resource_alignment(struct resource *res) |
1083 | { |
1084 | switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) { |
1085 | case IORESOURCE_SIZEALIGN: |
1086 | return resource_size(res); |
1087 | case IORESOURCE_STARTALIGN: |
1088 | return res->start; |
1089 | default: |
1090 | return 0; |
1091 | } |
1092 | } |
1093 | |
1094 | /* |
1095 | * This is compatibility stuff for IO resources. |
1096 | * |
1097 | * Note how this, unlike the above, knows about |
1098 | * the IO flag meanings (busy etc). |
1099 | * |
1100 | * request_region creates a new busy region. |
1101 | * |
1102 | * release_region releases a matching busy region. |
1103 | */ |
1104 | |
1105 | static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait); |
1106 | |
1107 | static struct inode *iomem_inode; |
1108 | |
1109 | #ifdef CONFIG_IO_STRICT_DEVMEM |
1110 | static void revoke_iomem(struct resource *res) |
1111 | { |
1112 | /* pairs with smp_store_release() in iomem_init_inode() */ |
1113 | struct inode *inode = smp_load_acquire(&iomem_inode); |
1114 | |
1115 | /* |
1116 | * Check that the initialization has completed. Losing the race |
1117 | * is ok because it means drivers are claiming resources before |
1118 | * the fs_initcall level of init and prevent iomem_get_mapping users |
1119 | * from establishing mappings. |
1120 | */ |
1121 | if (!inode) |
1122 | return; |
1123 | |
1124 | /* |
1125 | * The expectation is that the driver has successfully marked |
1126 | * the resource busy by this point, so devmem_is_allowed() |
1127 | * should start returning false, however for performance this |
1128 | * does not iterate the entire resource range. |
1129 | */ |
1130 | if (devmem_is_allowed(PHYS_PFN(res->start)) && |
1131 | devmem_is_allowed(PHYS_PFN(res->end))) { |
1132 | /* |
1133 | * *cringe* iomem=relaxed says "go ahead, what's the |
1134 | * worst that can happen?" |
1135 | */ |
1136 | return; |
1137 | } |
1138 | |
1139 | unmap_mapping_range(mapping: inode->i_mapping, holebegin: res->start, holelen: resource_size(res), even_cows: 1); |
1140 | } |
1141 | #else |
1142 | static void revoke_iomem(struct resource *res) {} |
1143 | #endif |
1144 | |
1145 | struct address_space *iomem_get_mapping(void) |
1146 | { |
1147 | /* |
1148 | * This function is only called from file open paths, hence guaranteed |
1149 | * that fs_initcalls have completed and no need to check for NULL. But |
1150 | * since revoke_iomem can be called before the initcall we still need |
1151 | * the barrier to appease checkers. |
1152 | */ |
1153 | return smp_load_acquire(&iomem_inode)->i_mapping; |
1154 | } |
1155 | |
1156 | static int __request_region_locked(struct resource *res, struct resource *parent, |
1157 | resource_size_t start, resource_size_t n, |
1158 | const char *name, int flags) |
1159 | { |
1160 | DECLARE_WAITQUEUE(wait, current); |
1161 | |
1162 | res->name = name; |
1163 | res->start = start; |
1164 | res->end = start + n - 1; |
1165 | |
1166 | for (;;) { |
1167 | struct resource *conflict; |
1168 | |
1169 | res->flags = resource_type(res: parent) | resource_ext_type(res: parent); |
1170 | res->flags |= IORESOURCE_BUSY | flags; |
1171 | res->desc = parent->desc; |
1172 | |
1173 | conflict = __request_resource(root: parent, new: res); |
1174 | if (!conflict) |
1175 | break; |
1176 | /* |
1177 | * mm/hmm.c reserves physical addresses which then |
1178 | * become unavailable to other users. Conflicts are |
1179 | * not expected. Warn to aid debugging if encountered. |
1180 | */ |
1181 | if (conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) { |
1182 | pr_warn("Unaddressable device %s %pR conflicts with %pR" , |
1183 | conflict->name, conflict, res); |
1184 | } |
1185 | if (conflict != parent) { |
1186 | if (!(conflict->flags & IORESOURCE_BUSY)) { |
1187 | parent = conflict; |
1188 | continue; |
1189 | } |
1190 | } |
1191 | if (conflict->flags & flags & IORESOURCE_MUXED) { |
1192 | add_wait_queue(wq_head: &muxed_resource_wait, wq_entry: &wait); |
1193 | write_unlock(&resource_lock); |
1194 | set_current_state(TASK_UNINTERRUPTIBLE); |
1195 | schedule(); |
1196 | remove_wait_queue(wq_head: &muxed_resource_wait, wq_entry: &wait); |
1197 | write_lock(&resource_lock); |
1198 | continue; |
1199 | } |
1200 | /* Uhhuh, that didn't work out.. */ |
1201 | return -EBUSY; |
1202 | } |
1203 | |
1204 | return 0; |
1205 | } |
1206 | |
1207 | /** |
1208 | * __request_region - create a new busy resource region |
1209 | * @parent: parent resource descriptor |
1210 | * @start: resource start address |
1211 | * @n: resource region size |
1212 | * @name: reserving caller's ID string |
1213 | * @flags: IO resource flags |
1214 | */ |
1215 | struct resource *__request_region(struct resource *parent, |
1216 | resource_size_t start, resource_size_t n, |
1217 | const char *name, int flags) |
1218 | { |
1219 | struct resource *res = alloc_resource(GFP_KERNEL); |
1220 | int ret; |
1221 | |
1222 | if (!res) |
1223 | return NULL; |
1224 | |
1225 | write_lock(&resource_lock); |
1226 | ret = __request_region_locked(res, parent, start, n, name, flags); |
1227 | write_unlock(&resource_lock); |
1228 | |
1229 | if (ret) { |
1230 | free_resource(res); |
1231 | return NULL; |
1232 | } |
1233 | |
1234 | if (parent == &iomem_resource) |
1235 | revoke_iomem(res); |
1236 | |
1237 | return res; |
1238 | } |
1239 | EXPORT_SYMBOL(__request_region); |
1240 | |
1241 | /** |
1242 | * __release_region - release a previously reserved resource region |
1243 | * @parent: parent resource descriptor |
1244 | * @start: resource start address |
1245 | * @n: resource region size |
1246 | * |
1247 | * The described resource region must match a currently busy region. |
1248 | */ |
1249 | void __release_region(struct resource *parent, resource_size_t start, |
1250 | resource_size_t n) |
1251 | { |
1252 | struct resource **p; |
1253 | resource_size_t end; |
1254 | |
1255 | p = &parent->child; |
1256 | end = start + n - 1; |
1257 | |
1258 | write_lock(&resource_lock); |
1259 | |
1260 | for (;;) { |
1261 | struct resource *res = *p; |
1262 | |
1263 | if (!res) |
1264 | break; |
1265 | if (res->start <= start && res->end >= end) { |
1266 | if (!(res->flags & IORESOURCE_BUSY)) { |
1267 | p = &res->child; |
1268 | continue; |
1269 | } |
1270 | if (res->start != start || res->end != end) |
1271 | break; |
1272 | *p = res->sibling; |
1273 | write_unlock(&resource_lock); |
1274 | if (res->flags & IORESOURCE_MUXED) |
1275 | wake_up(&muxed_resource_wait); |
1276 | free_resource(res); |
1277 | return; |
1278 | } |
1279 | p = &res->sibling; |
1280 | } |
1281 | |
1282 | write_unlock(&resource_lock); |
1283 | |
1284 | pr_warn("Trying to free nonexistent resource <%pa-%pa>\n" , &start, &end); |
1285 | } |
1286 | EXPORT_SYMBOL(__release_region); |
1287 | |
1288 | #ifdef CONFIG_MEMORY_HOTREMOVE |
1289 | /** |
1290 | * release_mem_region_adjustable - release a previously reserved memory region |
1291 | * @start: resource start address |
1292 | * @size: resource region size |
1293 | * |
1294 | * This interface is intended for memory hot-delete. The requested region |
1295 | * is released from a currently busy memory resource. The requested region |
1296 | * must either match exactly or fit into a single busy resource entry. In |
1297 | * the latter case, the remaining resource is adjusted accordingly. |
1298 | * Existing children of the busy memory resource must be immutable in the |
1299 | * request. |
1300 | * |
1301 | * Note: |
1302 | * - Additional release conditions, such as overlapping region, can be |
1303 | * supported after they are confirmed as valid cases. |
1304 | * - When a busy memory resource gets split into two entries, the code |
1305 | * assumes that all children remain in the lower address entry for |
1306 | * simplicity. Enhance this logic when necessary. |
1307 | */ |
1308 | void release_mem_region_adjustable(resource_size_t start, resource_size_t size) |
1309 | { |
1310 | struct resource *parent = &iomem_resource; |
1311 | struct resource *new_res = NULL; |
1312 | bool alloc_nofail = false; |
1313 | struct resource **p; |
1314 | struct resource *res; |
1315 | resource_size_t end; |
1316 | |
1317 | end = start + size - 1; |
1318 | if (WARN_ON_ONCE((start < parent->start) || (end > parent->end))) |
1319 | return; |
1320 | |
1321 | /* |
1322 | * We free up quite a lot of memory on memory hotunplug (esp., memap), |
1323 | * just before releasing the region. This is highly unlikely to |
1324 | * fail - let's play save and make it never fail as the caller cannot |
1325 | * perform any error handling (e.g., trying to re-add memory will fail |
1326 | * similarly). |
1327 | */ |
1328 | retry: |
1329 | new_res = alloc_resource(GFP_KERNEL | (alloc_nofail ? __GFP_NOFAIL : 0)); |
1330 | |
1331 | p = &parent->child; |
1332 | write_lock(&resource_lock); |
1333 | |
1334 | while ((res = *p)) { |
1335 | if (res->start >= end) |
1336 | break; |
1337 | |
1338 | /* look for the next resource if it does not fit into */ |
1339 | if (res->start > start || res->end < end) { |
1340 | p = &res->sibling; |
1341 | continue; |
1342 | } |
1343 | |
1344 | if (!(res->flags & IORESOURCE_MEM)) |
1345 | break; |
1346 | |
1347 | if (!(res->flags & IORESOURCE_BUSY)) { |
1348 | p = &res->child; |
1349 | continue; |
1350 | } |
1351 | |
1352 | /* found the target resource; let's adjust accordingly */ |
1353 | if (res->start == start && res->end == end) { |
1354 | /* free the whole entry */ |
1355 | *p = res->sibling; |
1356 | free_resource(res); |
1357 | } else if (res->start == start && res->end != end) { |
1358 | /* adjust the start */ |
1359 | WARN_ON_ONCE(__adjust_resource(res, end + 1, |
1360 | res->end - end)); |
1361 | } else if (res->start != start && res->end == end) { |
1362 | /* adjust the end */ |
1363 | WARN_ON_ONCE(__adjust_resource(res, res->start, |
1364 | start - res->start)); |
1365 | } else { |
1366 | /* split into two entries - we need a new resource */ |
1367 | if (!new_res) { |
1368 | new_res = alloc_resource(GFP_ATOMIC); |
1369 | if (!new_res) { |
1370 | alloc_nofail = true; |
1371 | write_unlock(&resource_lock); |
1372 | goto retry; |
1373 | } |
1374 | } |
1375 | new_res->name = res->name; |
1376 | new_res->start = end + 1; |
1377 | new_res->end = res->end; |
1378 | new_res->flags = res->flags; |
1379 | new_res->desc = res->desc; |
1380 | new_res->parent = res->parent; |
1381 | new_res->sibling = res->sibling; |
1382 | new_res->child = NULL; |
1383 | |
1384 | if (WARN_ON_ONCE(__adjust_resource(res, res->start, |
1385 | start - res->start))) |
1386 | break; |
1387 | res->sibling = new_res; |
1388 | new_res = NULL; |
1389 | } |
1390 | |
1391 | break; |
1392 | } |
1393 | |
1394 | write_unlock(&resource_lock); |
1395 | free_resource(res: new_res); |
1396 | } |
1397 | #endif /* CONFIG_MEMORY_HOTREMOVE */ |
1398 | |
1399 | #ifdef CONFIG_MEMORY_HOTPLUG |
1400 | static bool system_ram_resources_mergeable(struct resource *r1, |
1401 | struct resource *r2) |
1402 | { |
1403 | /* We assume either r1 or r2 is IORESOURCE_SYSRAM_MERGEABLE. */ |
1404 | return r1->flags == r2->flags && r1->end + 1 == r2->start && |
1405 | r1->name == r2->name && r1->desc == r2->desc && |
1406 | !r1->child && !r2->child; |
1407 | } |
1408 | |
1409 | /** |
1410 | * merge_system_ram_resource - mark the System RAM resource mergeable and try to |
1411 | * merge it with adjacent, mergeable resources |
1412 | * @res: resource descriptor |
1413 | * |
1414 | * This interface is intended for memory hotplug, whereby lots of contiguous |
1415 | * system ram resources are added (e.g., via add_memory*()) by a driver, and |
1416 | * the actual resource boundaries are not of interest (e.g., it might be |
1417 | * relevant for DIMMs). Only resources that are marked mergeable, that have the |
1418 | * same parent, and that don't have any children are considered. All mergeable |
1419 | * resources must be immutable during the request. |
1420 | * |
1421 | * Note: |
1422 | * - The caller has to make sure that no pointers to resources that are |
1423 | * marked mergeable are used anymore after this call - the resource might |
1424 | * be freed and the pointer might be stale! |
1425 | * - release_mem_region_adjustable() will split on demand on memory hotunplug |
1426 | */ |
1427 | void merge_system_ram_resource(struct resource *res) |
1428 | { |
1429 | const unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; |
1430 | struct resource *cur; |
1431 | |
1432 | if (WARN_ON_ONCE((res->flags & flags) != flags)) |
1433 | return; |
1434 | |
1435 | write_lock(&resource_lock); |
1436 | res->flags |= IORESOURCE_SYSRAM_MERGEABLE; |
1437 | |
1438 | /* Try to merge with next item in the list. */ |
1439 | cur = res->sibling; |
1440 | if (cur && system_ram_resources_mergeable(r1: res, r2: cur)) { |
1441 | res->end = cur->end; |
1442 | res->sibling = cur->sibling; |
1443 | free_resource(res: cur); |
1444 | } |
1445 | |
1446 | /* Try to merge with previous item in the list. */ |
1447 | cur = res->parent->child; |
1448 | while (cur && cur->sibling != res) |
1449 | cur = cur->sibling; |
1450 | if (cur && system_ram_resources_mergeable(r1: cur, r2: res)) { |
1451 | cur->end = res->end; |
1452 | cur->sibling = res->sibling; |
1453 | free_resource(res); |
1454 | } |
1455 | write_unlock(&resource_lock); |
1456 | } |
1457 | #endif /* CONFIG_MEMORY_HOTPLUG */ |
1458 | |
1459 | /* |
1460 | * Managed region resource |
1461 | */ |
1462 | static void devm_resource_release(struct device *dev, void *ptr) |
1463 | { |
1464 | struct resource **r = ptr; |
1465 | |
1466 | release_resource(*r); |
1467 | } |
1468 | |
1469 | /** |
1470 | * devm_request_resource() - request and reserve an I/O or memory resource |
1471 | * @dev: device for which to request the resource |
1472 | * @root: root of the resource tree from which to request the resource |
1473 | * @new: descriptor of the resource to request |
1474 | * |
1475 | * This is a device-managed version of request_resource(). There is usually |
1476 | * no need to release resources requested by this function explicitly since |
1477 | * that will be taken care of when the device is unbound from its driver. |
1478 | * If for some reason the resource needs to be released explicitly, because |
1479 | * of ordering issues for example, drivers must call devm_release_resource() |
1480 | * rather than the regular release_resource(). |
1481 | * |
1482 | * When a conflict is detected between any existing resources and the newly |
1483 | * requested resource, an error message will be printed. |
1484 | * |
1485 | * Returns 0 on success or a negative error code on failure. |
1486 | */ |
1487 | int devm_request_resource(struct device *dev, struct resource *root, |
1488 | struct resource *new) |
1489 | { |
1490 | struct resource *conflict, **ptr; |
1491 | |
1492 | ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL); |
1493 | if (!ptr) |
1494 | return -ENOMEM; |
1495 | |
1496 | *ptr = new; |
1497 | |
1498 | conflict = request_resource_conflict(root, new); |
1499 | if (conflict) { |
1500 | dev_err(dev, "resource collision: %pR conflicts with %s %pR\n" , |
1501 | new, conflict->name, conflict); |
1502 | devres_free(res: ptr); |
1503 | return -EBUSY; |
1504 | } |
1505 | |
1506 | devres_add(dev, res: ptr); |
1507 | return 0; |
1508 | } |
1509 | EXPORT_SYMBOL(devm_request_resource); |
1510 | |
1511 | static int devm_resource_match(struct device *dev, void *res, void *data) |
1512 | { |
1513 | struct resource **ptr = res; |
1514 | |
1515 | return *ptr == data; |
1516 | } |
1517 | |
1518 | /** |
1519 | * devm_release_resource() - release a previously requested resource |
1520 | * @dev: device for which to release the resource |
1521 | * @new: descriptor of the resource to release |
1522 | * |
1523 | * Releases a resource previously requested using devm_request_resource(). |
1524 | */ |
1525 | void devm_release_resource(struct device *dev, struct resource *new) |
1526 | { |
1527 | WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match, |
1528 | new)); |
1529 | } |
1530 | EXPORT_SYMBOL(devm_release_resource); |
1531 | |
1532 | struct region_devres { |
1533 | struct resource *parent; |
1534 | resource_size_t start; |
1535 | resource_size_t n; |
1536 | }; |
1537 | |
1538 | static void devm_region_release(struct device *dev, void *res) |
1539 | { |
1540 | struct region_devres *this = res; |
1541 | |
1542 | __release_region(this->parent, this->start, this->n); |
1543 | } |
1544 | |
1545 | static int devm_region_match(struct device *dev, void *res, void *match_data) |
1546 | { |
1547 | struct region_devres *this = res, *match = match_data; |
1548 | |
1549 | return this->parent == match->parent && |
1550 | this->start == match->start && this->n == match->n; |
1551 | } |
1552 | |
1553 | struct resource * |
1554 | __devm_request_region(struct device *dev, struct resource *parent, |
1555 | resource_size_t start, resource_size_t n, const char *name) |
1556 | { |
1557 | struct region_devres *dr = NULL; |
1558 | struct resource *res; |
1559 | |
1560 | dr = devres_alloc(devm_region_release, sizeof(struct region_devres), |
1561 | GFP_KERNEL); |
1562 | if (!dr) |
1563 | return NULL; |
1564 | |
1565 | dr->parent = parent; |
1566 | dr->start = start; |
1567 | dr->n = n; |
1568 | |
1569 | res = __request_region(parent, start, n, name, 0); |
1570 | if (res) |
1571 | devres_add(dev, res: dr); |
1572 | else |
1573 | devres_free(res: dr); |
1574 | |
1575 | return res; |
1576 | } |
1577 | EXPORT_SYMBOL(__devm_request_region); |
1578 | |
1579 | void __devm_release_region(struct device *dev, struct resource *parent, |
1580 | resource_size_t start, resource_size_t n) |
1581 | { |
1582 | struct region_devres match_data = { parent, start, n }; |
1583 | |
1584 | __release_region(parent, start, n); |
1585 | WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match, |
1586 | &match_data)); |
1587 | } |
1588 | EXPORT_SYMBOL(__devm_release_region); |
1589 | |
1590 | /* |
1591 | * Reserve I/O ports or memory based on "reserve=" kernel parameter. |
1592 | */ |
1593 | #define MAXRESERVE 4 |
1594 | static int __init reserve_setup(char *str) |
1595 | { |
1596 | static int reserved; |
1597 | static struct resource reserve[MAXRESERVE]; |
1598 | |
1599 | for (;;) { |
1600 | unsigned int io_start, io_num; |
1601 | int x = reserved; |
1602 | struct resource *parent; |
1603 | |
1604 | if (get_option(str: &str, pint: &io_start) != 2) |
1605 | break; |
1606 | if (get_option(str: &str, pint: &io_num) == 0) |
1607 | break; |
1608 | if (x < MAXRESERVE) { |
1609 | struct resource *res = reserve + x; |
1610 | |
1611 | /* |
1612 | * If the region starts below 0x10000, we assume it's |
1613 | * I/O port space; otherwise assume it's memory. |
1614 | */ |
1615 | if (io_start < 0x10000) { |
1616 | res->flags = IORESOURCE_IO; |
1617 | parent = &ioport_resource; |
1618 | } else { |
1619 | res->flags = IORESOURCE_MEM; |
1620 | parent = &iomem_resource; |
1621 | } |
1622 | res->name = "reserved" ; |
1623 | res->start = io_start; |
1624 | res->end = io_start + io_num - 1; |
1625 | res->flags |= IORESOURCE_BUSY; |
1626 | res->desc = IORES_DESC_NONE; |
1627 | res->child = NULL; |
1628 | if (request_resource(parent, res) == 0) |
1629 | reserved = x+1; |
1630 | } |
1631 | } |
1632 | return 1; |
1633 | } |
1634 | __setup("reserve=" , reserve_setup); |
1635 | |
1636 | /* |
1637 | * Check if the requested addr and size spans more than any slot in the |
1638 | * iomem resource tree. |
1639 | */ |
1640 | int iomem_map_sanity_check(resource_size_t addr, unsigned long size) |
1641 | { |
1642 | resource_size_t end = addr + size - 1; |
1643 | struct resource *p; |
1644 | int err = 0; |
1645 | |
1646 | read_lock(&resource_lock); |
1647 | for_each_resource(&iomem_resource, p, false) { |
1648 | /* |
1649 | * We can probably skip the resources without |
1650 | * IORESOURCE_IO attribute? |
1651 | */ |
1652 | if (p->start > end) |
1653 | continue; |
1654 | if (p->end < addr) |
1655 | continue; |
1656 | if (PFN_DOWN(p->start) <= PFN_DOWN(addr) && |
1657 | PFN_DOWN(p->end) >= PFN_DOWN(end)) |
1658 | continue; |
1659 | /* |
1660 | * if a resource is "BUSY", it's not a hardware resource |
1661 | * but a driver mapping of such a resource; we don't want |
1662 | * to warn for those; some drivers legitimately map only |
1663 | * partial hardware resources. (example: vesafb) |
1664 | */ |
1665 | if (p->flags & IORESOURCE_BUSY) |
1666 | continue; |
1667 | |
1668 | pr_warn("resource sanity check: requesting [mem %pa-%pa], which spans more than %s %pR\n" , |
1669 | &addr, &end, p->name, p); |
1670 | err = -1; |
1671 | break; |
1672 | } |
1673 | read_unlock(&resource_lock); |
1674 | |
1675 | return err; |
1676 | } |
1677 | |
1678 | #ifdef CONFIG_STRICT_DEVMEM |
1679 | static int strict_iomem_checks = 1; |
1680 | #else |
1681 | static int strict_iomem_checks; |
1682 | #endif |
1683 | |
1684 | /* |
1685 | * Check if an address is exclusive to the kernel and must not be mapped to |
1686 | * user space, for example, via /dev/mem. |
1687 | * |
1688 | * Returns true if exclusive to the kernel, otherwise returns false. |
1689 | */ |
1690 | bool resource_is_exclusive(struct resource *root, u64 addr, resource_size_t size) |
1691 | { |
1692 | const unsigned int exclusive_system_ram = IORESOURCE_SYSTEM_RAM | |
1693 | IORESOURCE_EXCLUSIVE; |
1694 | bool skip_children = false, err = false; |
1695 | struct resource *p; |
1696 | |
1697 | read_lock(&resource_lock); |
1698 | for_each_resource(root, p, skip_children) { |
1699 | if (p->start >= addr + size) |
1700 | break; |
1701 | if (p->end < addr) { |
1702 | skip_children = true; |
1703 | continue; |
1704 | } |
1705 | skip_children = false; |
1706 | |
1707 | /* |
1708 | * IORESOURCE_SYSTEM_RAM resources are exclusive if |
1709 | * IORESOURCE_EXCLUSIVE is set, even if they |
1710 | * are not busy and even if "iomem=relaxed" is set. The |
1711 | * responsible driver dynamically adds/removes system RAM within |
1712 | * such an area and uncontrolled access is dangerous. |
1713 | */ |
1714 | if ((p->flags & exclusive_system_ram) == exclusive_system_ram) { |
1715 | err = true; |
1716 | break; |
1717 | } |
1718 | |
1719 | /* |
1720 | * A resource is exclusive if IORESOURCE_EXCLUSIVE is set |
1721 | * or CONFIG_IO_STRICT_DEVMEM is enabled and the |
1722 | * resource is busy. |
1723 | */ |
1724 | if (!strict_iomem_checks || !(p->flags & IORESOURCE_BUSY)) |
1725 | continue; |
1726 | if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM) |
1727 | || p->flags & IORESOURCE_EXCLUSIVE) { |
1728 | err = true; |
1729 | break; |
1730 | } |
1731 | } |
1732 | read_unlock(&resource_lock); |
1733 | |
1734 | return err; |
1735 | } |
1736 | |
1737 | bool iomem_is_exclusive(u64 addr) |
1738 | { |
1739 | return resource_is_exclusive(root: &iomem_resource, addr: addr & PAGE_MASK, |
1740 | PAGE_SIZE); |
1741 | } |
1742 | |
1743 | struct resource_entry *resource_list_create_entry(struct resource *res, |
1744 | size_t ) |
1745 | { |
1746 | struct resource_entry *entry; |
1747 | |
1748 | entry = kzalloc(size: sizeof(*entry) + extra_size, GFP_KERNEL); |
1749 | if (entry) { |
1750 | INIT_LIST_HEAD(list: &entry->node); |
1751 | entry->res = res ? res : &entry->__res; |
1752 | } |
1753 | |
1754 | return entry; |
1755 | } |
1756 | EXPORT_SYMBOL(resource_list_create_entry); |
1757 | |
1758 | void resource_list_free(struct list_head *head) |
1759 | { |
1760 | struct resource_entry *entry, *tmp; |
1761 | |
1762 | list_for_each_entry_safe(entry, tmp, head, node) |
1763 | resource_list_destroy_entry(entry); |
1764 | } |
1765 | EXPORT_SYMBOL(resource_list_free); |
1766 | |
1767 | #ifdef CONFIG_GET_FREE_REGION |
1768 | #define GFR_DESCENDING (1UL << 0) |
1769 | #define GFR_REQUEST_REGION (1UL << 1) |
1770 | #define GFR_DEFAULT_ALIGN (1UL << PA_SECTION_SHIFT) |
1771 | |
1772 | static resource_size_t gfr_start(struct resource *base, resource_size_t size, |
1773 | resource_size_t align, unsigned long flags) |
1774 | { |
1775 | if (flags & GFR_DESCENDING) { |
1776 | resource_size_t end; |
1777 | |
1778 | end = min_t(resource_size_t, base->end, |
1779 | (1ULL << MAX_PHYSMEM_BITS) - 1); |
1780 | return end - size + 1; |
1781 | } |
1782 | |
1783 | return ALIGN(base->start, align); |
1784 | } |
1785 | |
1786 | static bool gfr_continue(struct resource *base, resource_size_t addr, |
1787 | resource_size_t size, unsigned long flags) |
1788 | { |
1789 | if (flags & GFR_DESCENDING) |
1790 | return addr > size && addr >= base->start; |
1791 | /* |
1792 | * In the ascend case be careful that the last increment by |
1793 | * @size did not wrap 0. |
1794 | */ |
1795 | return addr > addr - size && |
1796 | addr <= min_t(resource_size_t, base->end, |
1797 | (1ULL << MAX_PHYSMEM_BITS) - 1); |
1798 | } |
1799 | |
1800 | static resource_size_t gfr_next(resource_size_t addr, resource_size_t size, |
1801 | unsigned long flags) |
1802 | { |
1803 | if (flags & GFR_DESCENDING) |
1804 | return addr - size; |
1805 | return addr + size; |
1806 | } |
1807 | |
1808 | static void remove_free_mem_region(void *_res) |
1809 | { |
1810 | struct resource *res = _res; |
1811 | |
1812 | if (res->parent) |
1813 | remove_resource(res); |
1814 | free_resource(res); |
1815 | } |
1816 | |
1817 | static struct resource * |
1818 | get_free_mem_region(struct device *dev, struct resource *base, |
1819 | resource_size_t size, const unsigned long align, |
1820 | const char *name, const unsigned long desc, |
1821 | const unsigned long flags) |
1822 | { |
1823 | resource_size_t addr; |
1824 | struct resource *res; |
1825 | struct region_devres *dr = NULL; |
1826 | |
1827 | size = ALIGN(size, align); |
1828 | |
1829 | res = alloc_resource(GFP_KERNEL); |
1830 | if (!res) |
1831 | return ERR_PTR(error: -ENOMEM); |
1832 | |
1833 | if (dev && (flags & GFR_REQUEST_REGION)) { |
1834 | dr = devres_alloc(devm_region_release, |
1835 | sizeof(struct region_devres), GFP_KERNEL); |
1836 | if (!dr) { |
1837 | free_resource(res); |
1838 | return ERR_PTR(error: -ENOMEM); |
1839 | } |
1840 | } else if (dev) { |
1841 | if (devm_add_action_or_reset(dev, remove_free_mem_region, res)) |
1842 | return ERR_PTR(error: -ENOMEM); |
1843 | } |
1844 | |
1845 | write_lock(&resource_lock); |
1846 | for (addr = gfr_start(base, size, align, flags); |
1847 | gfr_continue(base, addr, size, flags); |
1848 | addr = gfr_next(addr, size, flags)) { |
1849 | if (__region_intersects(parent: base, start: addr, size, flags: 0, desc: IORES_DESC_NONE) != |
1850 | REGION_DISJOINT) |
1851 | continue; |
1852 | |
1853 | if (flags & GFR_REQUEST_REGION) { |
1854 | if (__request_region_locked(res, parent: &iomem_resource, start: addr, |
1855 | n: size, name, flags: 0)) |
1856 | break; |
1857 | |
1858 | if (dev) { |
1859 | dr->parent = &iomem_resource; |
1860 | dr->start = addr; |
1861 | dr->n = size; |
1862 | devres_add(dev, res: dr); |
1863 | } |
1864 | |
1865 | res->desc = desc; |
1866 | write_unlock(&resource_lock); |
1867 | |
1868 | |
1869 | /* |
1870 | * A driver is claiming this region so revoke any |
1871 | * mappings. |
1872 | */ |
1873 | revoke_iomem(res); |
1874 | } else { |
1875 | res->start = addr; |
1876 | res->end = addr + size - 1; |
1877 | res->name = name; |
1878 | res->desc = desc; |
1879 | res->flags = IORESOURCE_MEM; |
1880 | |
1881 | /* |
1882 | * Only succeed if the resource hosts an exclusive |
1883 | * range after the insert |
1884 | */ |
1885 | if (__insert_resource(parent: base, new: res) || res->child) |
1886 | break; |
1887 | |
1888 | write_unlock(&resource_lock); |
1889 | } |
1890 | |
1891 | return res; |
1892 | } |
1893 | write_unlock(&resource_lock); |
1894 | |
1895 | if (flags & GFR_REQUEST_REGION) { |
1896 | free_resource(res); |
1897 | devres_free(res: dr); |
1898 | } else if (dev) |
1899 | devm_release_action(dev, action: remove_free_mem_region, data: res); |
1900 | |
1901 | return ERR_PTR(error: -ERANGE); |
1902 | } |
1903 | |
1904 | /** |
1905 | * devm_request_free_mem_region - find free region for device private memory |
1906 | * |
1907 | * @dev: device struct to bind the resource to |
1908 | * @size: size in bytes of the device memory to add |
1909 | * @base: resource tree to look in |
1910 | * |
1911 | * This function tries to find an empty range of physical address big enough to |
1912 | * contain the new resource, so that it can later be hotplugged as ZONE_DEVICE |
1913 | * memory, which in turn allocates struct pages. |
1914 | */ |
1915 | struct resource *devm_request_free_mem_region(struct device *dev, |
1916 | struct resource *base, unsigned long size) |
1917 | { |
1918 | unsigned long flags = GFR_DESCENDING | GFR_REQUEST_REGION; |
1919 | |
1920 | return get_free_mem_region(dev, base, size, GFR_DEFAULT_ALIGN, |
1921 | name: dev_name(dev), |
1922 | desc: IORES_DESC_DEVICE_PRIVATE_MEMORY, flags); |
1923 | } |
1924 | EXPORT_SYMBOL_GPL(devm_request_free_mem_region); |
1925 | |
1926 | struct resource *request_free_mem_region(struct resource *base, |
1927 | unsigned long size, const char *name) |
1928 | { |
1929 | unsigned long flags = GFR_DESCENDING | GFR_REQUEST_REGION; |
1930 | |
1931 | return get_free_mem_region(NULL, base, size, GFR_DEFAULT_ALIGN, name, |
1932 | desc: IORES_DESC_DEVICE_PRIVATE_MEMORY, flags); |
1933 | } |
1934 | EXPORT_SYMBOL_GPL(request_free_mem_region); |
1935 | |
1936 | /** |
1937 | * alloc_free_mem_region - find a free region relative to @base |
1938 | * @base: resource that will parent the new resource |
1939 | * @size: size in bytes of memory to allocate from @base |
1940 | * @align: alignment requirements for the allocation |
1941 | * @name: resource name |
1942 | * |
1943 | * Buses like CXL, that can dynamically instantiate new memory regions, |
1944 | * need a method to allocate physical address space for those regions. |
1945 | * Allocate and insert a new resource to cover a free, unclaimed by a |
1946 | * descendant of @base, range in the span of @base. |
1947 | */ |
1948 | struct resource *alloc_free_mem_region(struct resource *base, |
1949 | unsigned long size, unsigned long align, |
1950 | const char *name) |
1951 | { |
1952 | /* Default of ascending direction and insert resource */ |
1953 | unsigned long flags = 0; |
1954 | |
1955 | return get_free_mem_region(NULL, base, size, align, name, |
1956 | desc: IORES_DESC_NONE, flags); |
1957 | } |
1958 | EXPORT_SYMBOL_NS_GPL(alloc_free_mem_region, CXL); |
1959 | #endif /* CONFIG_GET_FREE_REGION */ |
1960 | |
1961 | static int __init strict_iomem(char *str) |
1962 | { |
1963 | if (strstr(str, "relaxed" )) |
1964 | strict_iomem_checks = 0; |
1965 | if (strstr(str, "strict" )) |
1966 | strict_iomem_checks = 1; |
1967 | return 1; |
1968 | } |
1969 | |
1970 | static int iomem_fs_init_fs_context(struct fs_context *fc) |
1971 | { |
1972 | return init_pseudo(fc, DEVMEM_MAGIC) ? 0 : -ENOMEM; |
1973 | } |
1974 | |
1975 | static struct file_system_type iomem_fs_type = { |
1976 | .name = "iomem" , |
1977 | .owner = THIS_MODULE, |
1978 | .init_fs_context = iomem_fs_init_fs_context, |
1979 | .kill_sb = kill_anon_super, |
1980 | }; |
1981 | |
1982 | static int __init iomem_init_inode(void) |
1983 | { |
1984 | static struct vfsmount *iomem_vfs_mount; |
1985 | static int iomem_fs_cnt; |
1986 | struct inode *inode; |
1987 | int rc; |
1988 | |
1989 | rc = simple_pin_fs(&iomem_fs_type, mount: &iomem_vfs_mount, count: &iomem_fs_cnt); |
1990 | if (rc < 0) { |
1991 | pr_err("Cannot mount iomem pseudo filesystem: %d\n" , rc); |
1992 | return rc; |
1993 | } |
1994 | |
1995 | inode = alloc_anon_inode(iomem_vfs_mount->mnt_sb); |
1996 | if (IS_ERR(ptr: inode)) { |
1997 | rc = PTR_ERR(ptr: inode); |
1998 | pr_err("Cannot allocate inode for iomem: %d\n" , rc); |
1999 | simple_release_fs(mount: &iomem_vfs_mount, count: &iomem_fs_cnt); |
2000 | return rc; |
2001 | } |
2002 | |
2003 | /* |
2004 | * Publish iomem revocation inode initialized. |
2005 | * Pairs with smp_load_acquire() in revoke_iomem(). |
2006 | */ |
2007 | smp_store_release(&iomem_inode, inode); |
2008 | |
2009 | return 0; |
2010 | } |
2011 | |
2012 | fs_initcall(iomem_init_inode); |
2013 | |
2014 | __setup("iomem=" , strict_iomem); |
2015 | |