Line data Source code
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)
60 : {
61 0 : if (p->child)
62 : return p->child;
63 0 : while (!p->sibling && p->parent)
64 : p = p->parent;
65 : return p->sibling;
66 : }
67 :
68 : static struct resource *next_resource_skip_children(struct resource *p)
69 : {
70 0 : while (!p->sibling && p->parent)
71 : p = p->parent;
72 : return p->sibling;
73 : }
74 :
75 : #define for_each_resource(_root, _p, _skip_children) \
76 : for ((_p) = (_root)->child; (_p); \
77 : (_p) = (_skip_children) ? next_resource_skip_children(_p) : \
78 : next_resource(_p))
79 :
80 0 : static void *r_next(struct seq_file *m, void *v, loff_t *pos)
81 : {
82 0 : struct resource *p = v;
83 0 : (*pos)++;
84 0 : return (void *)next_resource(p);
85 : }
86 :
87 : #ifdef CONFIG_PROC_FS
88 :
89 : enum { MAX_IORES_LEVEL = 5 };
90 :
91 0 : static void *r_start(struct seq_file *m, loff_t *pos)
92 : __acquires(resource_lock)
93 : {
94 0 : struct resource *p = pde_data(file_inode(m->file));
95 0 : loff_t l = 0;
96 0 : read_lock(&resource_lock);
97 0 : for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
98 : ;
99 0 : return p;
100 : }
101 :
102 0 : static void r_stop(struct seq_file *m, void *v)
103 : __releases(resource_lock)
104 : {
105 0 : read_unlock(&resource_lock);
106 0 : }
107 :
108 0 : static int r_show(struct seq_file *m, void *v)
109 : {
110 0 : struct resource *root = pde_data(file_inode(m->file));
111 0 : struct resource *r = v, *p;
112 : unsigned long long start, end;
113 0 : int width = root->end < 0x10000 ? 4 : 8;
114 : int depth;
115 :
116 0 : for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
117 0 : if (p->parent == root)
118 : break;
119 :
120 0 : if (file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN)) {
121 0 : start = r->start;
122 0 : end = r->end;
123 : } else {
124 : start = end = 0;
125 : }
126 :
127 0 : seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
128 : depth * 2, "",
129 : width, start,
130 : width, end,
131 0 : r->name ? r->name : "<BAD>");
132 0 : return 0;
133 : }
134 :
135 : static const struct seq_operations resource_op = {
136 : .start = r_start,
137 : .next = r_next,
138 : .stop = r_stop,
139 : .show = r_show,
140 : };
141 :
142 1 : static int __init ioresources_init(void)
143 : {
144 1 : proc_create_seq_data("ioports", 0, NULL, &resource_op,
145 : &ioport_resource);
146 1 : proc_create_seq_data("iomem", 0, NULL, &resource_op, &iomem_resource);
147 1 : return 0;
148 : }
149 : __initcall(ioresources_init);
150 :
151 : #endif /* CONFIG_PROC_FS */
152 :
153 0 : static void free_resource(struct resource *res)
154 : {
155 : /**
156 : * If the resource was allocated using memblock early during boot
157 : * we'll leak it here: we can only return full pages back to the
158 : * buddy and trying to be smart and reusing them eventually in
159 : * alloc_resource() overcomplicates resource handling.
160 : */
161 0 : if (res && PageSlab(virt_to_head_page(res)))
162 0 : kfree(res);
163 0 : }
164 :
165 : static struct resource *alloc_resource(gfp_t flags)
166 : {
167 0 : return kzalloc(sizeof(struct resource), flags);
168 : }
169 :
170 : /* Return the conflict entry if you can't request it */
171 2 : static struct resource * __request_resource(struct resource *root, struct resource *new)
172 : {
173 2 : resource_size_t start = new->start;
174 2 : resource_size_t end = new->end;
175 : struct resource *tmp, **p;
176 :
177 2 : if (end < start)
178 : return root;
179 2 : if (start < root->start)
180 : return root;
181 2 : if (end > root->end)
182 : return root;
183 2 : p = &root->child;
184 : for (;;) {
185 4 : tmp = *p;
186 3 : if (!tmp || tmp->start > end) {
187 2 : new->sibling = tmp;
188 2 : *p = new;
189 2 : new->parent = root;
190 2 : return NULL;
191 : }
192 1 : p = &tmp->sibling;
193 1 : if (tmp->end < start)
194 1 : continue;
195 : return tmp;
196 : }
197 : }
198 :
199 0 : static int __release_resource(struct resource *old, bool release_child)
200 : {
201 : struct resource *tmp, **p, *chd;
202 :
203 0 : p = &old->parent->child;
204 : for (;;) {
205 0 : tmp = *p;
206 0 : if (!tmp)
207 : break;
208 0 : if (tmp == old) {
209 0 : if (release_child || !(tmp->child)) {
210 0 : *p = tmp->sibling;
211 : } else {
212 : for (chd = tmp->child;; chd = chd->sibling) {
213 0 : chd->parent = tmp->parent;
214 0 : if (!(chd->sibling))
215 : break;
216 : }
217 0 : *p = tmp->child;
218 0 : chd->sibling = tmp->sibling;
219 : }
220 0 : old->parent = NULL;
221 0 : return 0;
222 : }
223 0 : p = &tmp->sibling;
224 : }
225 : return -EINVAL;
226 : }
227 :
228 0 : static void __release_child_resources(struct resource *r)
229 : {
230 : struct resource *tmp, *p;
231 : resource_size_t size;
232 :
233 0 : p = r->child;
234 0 : r->child = NULL;
235 0 : while (p) {
236 0 : tmp = p;
237 0 : p = p->sibling;
238 :
239 0 : tmp->parent = NULL;
240 0 : tmp->sibling = NULL;
241 0 : __release_child_resources(tmp);
242 :
243 0 : printk(KERN_DEBUG "release child resource %pR\n", tmp);
244 : /* need to restore size, and keep flags */
245 0 : size = resource_size(tmp);
246 0 : tmp->start = 0;
247 0 : tmp->end = size - 1;
248 : }
249 0 : }
250 :
251 0 : void release_child_resources(struct resource *r)
252 : {
253 0 : write_lock(&resource_lock);
254 0 : __release_child_resources(r);
255 0 : write_unlock(&resource_lock);
256 0 : }
257 :
258 : /**
259 : * request_resource_conflict - request and reserve an I/O or memory resource
260 : * @root: root resource descriptor
261 : * @new: resource descriptor desired by caller
262 : *
263 : * Returns 0 for success, conflict resource on error.
264 : */
265 0 : struct resource *request_resource_conflict(struct resource *root, struct resource *new)
266 : {
267 : struct resource *conflict;
268 :
269 2 : write_lock(&resource_lock);
270 2 : conflict = __request_resource(root, new);
271 2 : write_unlock(&resource_lock);
272 0 : return conflict;
273 : }
274 :
275 : /**
276 : * request_resource - request and reserve an I/O or memory resource
277 : * @root: root resource descriptor
278 : * @new: resource descriptor desired by caller
279 : *
280 : * Returns 0 for success, negative error code on error.
281 : */
282 2 : int request_resource(struct resource *root, struct resource *new)
283 : {
284 : struct resource *conflict;
285 :
286 2 : conflict = request_resource_conflict(root, new);
287 2 : return conflict ? -EBUSY : 0;
288 : }
289 :
290 : EXPORT_SYMBOL(request_resource);
291 :
292 : /**
293 : * release_resource - release a previously reserved resource
294 : * @old: resource pointer
295 : */
296 0 : int release_resource(struct resource *old)
297 : {
298 : int retval;
299 :
300 0 : write_lock(&resource_lock);
301 0 : retval = __release_resource(old, true);
302 0 : write_unlock(&resource_lock);
303 0 : return retval;
304 : }
305 :
306 : EXPORT_SYMBOL(release_resource);
307 :
308 : /**
309 : * find_next_iomem_res - Finds the lowest iomem resource that covers part of
310 : * [@start..@end].
311 : *
312 : * If a resource is found, returns 0 and @*res is overwritten with the part
313 : * of the resource that's within [@start..@end]; if none is found, returns
314 : * -ENODEV. Returns -EINVAL for invalid parameters.
315 : *
316 : * @start: start address of the resource searched for
317 : * @end: end address of same resource
318 : * @flags: flags which the resource must have
319 : * @desc: descriptor the resource must have
320 : * @res: return ptr, if resource found
321 : *
322 : * The caller must specify @start, @end, @flags, and @desc
323 : * (which may be IORES_DESC_NONE).
324 : */
325 0 : static int find_next_iomem_res(resource_size_t start, resource_size_t end,
326 : unsigned long flags, unsigned long desc,
327 : struct resource *res)
328 : {
329 : struct resource *p;
330 :
331 0 : if (!res)
332 : return -EINVAL;
333 :
334 0 : if (start >= end)
335 : return -EINVAL;
336 :
337 0 : read_lock(&resource_lock);
338 :
339 0 : for (p = iomem_resource.child; p; p = next_resource(p)) {
340 : /* If we passed the resource we are looking for, stop */
341 0 : if (p->start > end) {
342 : p = NULL;
343 : break;
344 : }
345 :
346 : /* Skip until we find a range that matches what we look for */
347 0 : if (p->end < start)
348 0 : continue;
349 :
350 0 : if ((p->flags & flags) != flags)
351 0 : continue;
352 0 : if ((desc != IORES_DESC_NONE) && (desc != p->desc))
353 0 : continue;
354 :
355 : /* Found a match, break */
356 : break;
357 : }
358 :
359 0 : if (p) {
360 : /* copy data */
361 0 : *res = (struct resource) {
362 0 : .start = max(start, p->start),
363 0 : .end = min(end, p->end),
364 0 : .flags = p->flags,
365 0 : .desc = p->desc,
366 0 : .parent = p->parent,
367 : };
368 : }
369 :
370 0 : read_unlock(&resource_lock);
371 0 : return p ? 0 : -ENODEV;
372 : }
373 :
374 0 : static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
375 : unsigned long flags, unsigned long desc,
376 : void *arg,
377 : int (*func)(struct resource *, void *))
378 : {
379 : struct resource res;
380 0 : int ret = -EINVAL;
381 :
382 0 : while (start < end &&
383 0 : !find_next_iomem_res(start, end, flags, desc, &res)) {
384 0 : ret = (*func)(&res, arg);
385 0 : if (ret)
386 : break;
387 :
388 0 : start = res.end + 1;
389 : }
390 :
391 0 : return ret;
392 : }
393 :
394 : /**
395 : * walk_iomem_res_desc - Walks through iomem resources and calls func()
396 : * with matching resource ranges.
397 : * *
398 : * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check.
399 : * @flags: I/O resource flags
400 : * @start: start addr
401 : * @end: end addr
402 : * @arg: function argument for the callback @func
403 : * @func: callback function that is called for each qualifying resource area
404 : *
405 : * All the memory ranges which overlap start,end and also match flags and
406 : * desc are valid candidates.
407 : *
408 : * NOTE: For a new descriptor search, define a new IORES_DESC in
409 : * <linux/ioport.h> and set it in 'desc' of a target resource entry.
410 : */
411 0 : int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start,
412 : u64 end, void *arg, int (*func)(struct resource *, void *))
413 : {
414 0 : return __walk_iomem_res_desc(start, end, flags, desc, arg, func);
415 : }
416 : EXPORT_SYMBOL_GPL(walk_iomem_res_desc);
417 :
418 : /*
419 : * This function calls the @func callback against all memory ranges of type
420 : * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
421 : * Now, this function is only for System RAM, it deals with full ranges and
422 : * not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate
423 : * ranges.
424 : */
425 0 : int walk_system_ram_res(u64 start, u64 end, void *arg,
426 : int (*func)(struct resource *, void *))
427 : {
428 0 : unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
429 :
430 0 : return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, arg,
431 : func);
432 : }
433 :
434 : /*
435 : * This function calls the @func callback against all memory ranges, which
436 : * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY.
437 : */
438 0 : int walk_mem_res(u64 start, u64 end, void *arg,
439 : int (*func)(struct resource *, void *))
440 : {
441 0 : unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY;
442 :
443 0 : return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, arg,
444 : func);
445 : }
446 :
447 : /*
448 : * This function calls the @func callback against all memory ranges of type
449 : * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
450 : * It is to be used only for System RAM.
451 : */
452 0 : int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
453 : void *arg, int (*func)(unsigned long, unsigned long, void *))
454 : {
455 : resource_size_t start, end;
456 : unsigned long flags;
457 : struct resource res;
458 : unsigned long pfn, end_pfn;
459 0 : int ret = -EINVAL;
460 :
461 0 : start = (u64) start_pfn << PAGE_SHIFT;
462 0 : end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
463 0 : flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
464 0 : while (start < end &&
465 0 : !find_next_iomem_res(start, end, flags, IORES_DESC_NONE, &res)) {
466 0 : pfn = PFN_UP(res.start);
467 0 : end_pfn = PFN_DOWN(res.end + 1);
468 0 : if (end_pfn > pfn)
469 0 : ret = (*func)(pfn, end_pfn - pfn, arg);
470 0 : if (ret)
471 : break;
472 0 : start = res.end + 1;
473 : }
474 0 : return ret;
475 : }
476 :
477 0 : static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
478 : {
479 0 : return 1;
480 : }
481 :
482 : /*
483 : * This generic page_is_ram() returns true if specified address is
484 : * registered as System RAM in iomem_resource list.
485 : */
486 0 : int __weak page_is_ram(unsigned long pfn)
487 : {
488 0 : return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
489 : }
490 : EXPORT_SYMBOL_GPL(page_is_ram);
491 :
492 0 : static int __region_intersects(resource_size_t start, size_t size,
493 : unsigned long flags, unsigned long desc)
494 : {
495 : struct resource res;
496 0 : int type = 0; int other = 0;
497 : struct resource *p;
498 :
499 0 : res.start = start;
500 0 : res.end = start + size - 1;
501 :
502 0 : for (p = iomem_resource.child; p ; p = p->sibling) {
503 0 : bool is_type = (((p->flags & flags) == flags) &&
504 0 : ((desc == IORES_DESC_NONE) ||
505 0 : (desc == p->desc)));
506 :
507 0 : if (resource_overlaps(p, &res))
508 0 : is_type ? type++ : other++;
509 : }
510 :
511 0 : if (type == 0)
512 : return REGION_DISJOINT;
513 :
514 0 : if (other == 0)
515 : return REGION_INTERSECTS;
516 :
517 0 : return REGION_MIXED;
518 : }
519 :
520 : /**
521 : * region_intersects() - determine intersection of region with known resources
522 : * @start: region start address
523 : * @size: size of region
524 : * @flags: flags of resource (in iomem_resource)
525 : * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE
526 : *
527 : * Check if the specified region partially overlaps or fully eclipses a
528 : * resource identified by @flags and @desc (optional with IORES_DESC_NONE).
529 : * Return REGION_DISJOINT if the region does not overlap @flags/@desc,
530 : * return REGION_MIXED if the region overlaps @flags/@desc and another
531 : * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc
532 : * and no other defined resource. Note that REGION_INTERSECTS is also
533 : * returned in the case when the specified region overlaps RAM and undefined
534 : * memory holes.
535 : *
536 : * region_intersect() is used by memory remapping functions to ensure
537 : * the user is not remapping RAM and is a vast speed up over walking
538 : * through the resource table page by page.
539 : */
540 0 : int region_intersects(resource_size_t start, size_t size, unsigned long flags,
541 : unsigned long desc)
542 : {
543 : int ret;
544 :
545 0 : read_lock(&resource_lock);
546 0 : ret = __region_intersects(start, size, flags, desc);
547 0 : read_unlock(&resource_lock);
548 :
549 0 : return ret;
550 : }
551 : EXPORT_SYMBOL_GPL(region_intersects);
552 :
553 0 : void __weak arch_remove_reservations(struct resource *avail)
554 : {
555 0 : }
556 :
557 0 : static resource_size_t simple_align_resource(void *data,
558 : const struct resource *avail,
559 : resource_size_t size,
560 : resource_size_t align)
561 : {
562 0 : return avail->start;
563 : }
564 :
565 : static void resource_clip(struct resource *res, resource_size_t min,
566 : resource_size_t max)
567 : {
568 0 : if (res->start < min)
569 0 : res->start = min;
570 0 : if (res->end > max)
571 0 : res->end = max;
572 : }
573 :
574 : /*
575 : * Find empty slot in the resource tree with the given range and
576 : * alignment constraints
577 : */
578 0 : static int __find_resource(struct resource *root, struct resource *old,
579 : struct resource *new,
580 : resource_size_t size,
581 : struct resource_constraint *constraint)
582 : {
583 0 : struct resource *this = root->child;
584 0 : struct resource tmp = *new, avail, alloc;
585 :
586 0 : tmp.start = root->start;
587 : /*
588 : * Skip past an allocated resource that starts at 0, since the assignment
589 : * of this->start - 1 to tmp->end below would cause an underflow.
590 : */
591 0 : if (this && this->start == root->start) {
592 0 : tmp.start = (this == old) ? old->start : this->end + 1;
593 0 : this = this->sibling;
594 : }
595 : for(;;) {
596 0 : if (this)
597 0 : tmp.end = (this == old) ? this->end : this->start - 1;
598 : else
599 0 : tmp.end = root->end;
600 :
601 0 : if (tmp.end < tmp.start)
602 : goto next;
603 :
604 0 : resource_clip(&tmp, constraint->min, constraint->max);
605 0 : arch_remove_reservations(&tmp);
606 :
607 : /* Check for overflow after ALIGN() */
608 0 : avail.start = ALIGN(tmp.start, constraint->align);
609 0 : avail.end = tmp.end;
610 0 : avail.flags = new->flags & ~IORESOURCE_UNSET;
611 0 : if (avail.start >= tmp.start) {
612 0 : alloc.flags = avail.flags;
613 0 : alloc.start = constraint->alignf(constraint->alignf_data, &avail,
614 : size, constraint->align);
615 0 : alloc.end = alloc.start + size - 1;
616 0 : if (alloc.start <= alloc.end &&
617 0 : resource_contains(&avail, &alloc)) {
618 0 : new->start = alloc.start;
619 0 : new->end = alloc.end;
620 0 : return 0;
621 : }
622 : }
623 :
624 0 : next: if (!this || this->end == root->end)
625 : break;
626 :
627 0 : if (this != old)
628 0 : tmp.start = this->end + 1;
629 0 : this = this->sibling;
630 : }
631 : return -EBUSY;
632 : }
633 :
634 : /*
635 : * Find empty slot in the resource tree given range and alignment.
636 : */
637 : static int find_resource(struct resource *root, struct resource *new,
638 : resource_size_t size,
639 : struct resource_constraint *constraint)
640 : {
641 0 : return __find_resource(root, NULL, new, size, constraint);
642 : }
643 :
644 : /**
645 : * reallocate_resource - allocate a slot in the resource tree given range & alignment.
646 : * The resource will be relocated if the new size cannot be reallocated in the
647 : * current location.
648 : *
649 : * @root: root resource descriptor
650 : * @old: resource descriptor desired by caller
651 : * @newsize: new size of the resource descriptor
652 : * @constraint: the size and alignment constraints to be met.
653 : */
654 0 : static int reallocate_resource(struct resource *root, struct resource *old,
655 : resource_size_t newsize,
656 : struct resource_constraint *constraint)
657 : {
658 0 : int err=0;
659 0 : struct resource new = *old;
660 : struct resource *conflict;
661 :
662 0 : write_lock(&resource_lock);
663 :
664 0 : if ((err = __find_resource(root, old, &new, newsize, constraint)))
665 : goto out;
666 :
667 0 : if (resource_contains(&new, old)) {
668 0 : old->start = new.start;
669 0 : old->end = new.end;
670 0 : goto out;
671 : }
672 :
673 0 : if (old->child) {
674 : err = -EBUSY;
675 : goto out;
676 : }
677 :
678 0 : if (resource_contains(old, &new)) {
679 0 : old->start = new.start;
680 0 : old->end = new.end;
681 : } else {
682 0 : __release_resource(old, true);
683 0 : *old = new;
684 0 : conflict = __request_resource(root, old);
685 0 : BUG_ON(conflict);
686 : }
687 : out:
688 0 : write_unlock(&resource_lock);
689 0 : return err;
690 : }
691 :
692 :
693 : /**
694 : * allocate_resource - allocate empty slot in the resource tree given range & alignment.
695 : * The resource will be reallocated with a new size if it was already allocated
696 : * @root: root resource descriptor
697 : * @new: resource descriptor desired by caller
698 : * @size: requested resource region size
699 : * @min: minimum boundary to allocate
700 : * @max: maximum boundary to allocate
701 : * @align: alignment requested, in bytes
702 : * @alignf: alignment function, optional, called if not NULL
703 : * @alignf_data: arbitrary data to pass to the @alignf function
704 : */
705 0 : int allocate_resource(struct resource *root, struct resource *new,
706 : resource_size_t size, resource_size_t min,
707 : resource_size_t max, resource_size_t align,
708 : resource_size_t (*alignf)(void *,
709 : const struct resource *,
710 : resource_size_t,
711 : resource_size_t),
712 : void *alignf_data)
713 : {
714 : int err;
715 : struct resource_constraint constraint;
716 :
717 0 : if (!alignf)
718 0 : alignf = simple_align_resource;
719 :
720 0 : constraint.min = min;
721 0 : constraint.max = max;
722 0 : constraint.align = align;
723 0 : constraint.alignf = alignf;
724 0 : constraint.alignf_data = alignf_data;
725 :
726 0 : if ( new->parent ) {
727 : /* resource is already allocated, try reallocating with
728 : the new constraints */
729 0 : return reallocate_resource(root, new, size, &constraint);
730 : }
731 :
732 0 : write_lock(&resource_lock);
733 0 : err = find_resource(root, new, size, &constraint);
734 0 : if (err >= 0 && __request_resource(root, new))
735 0 : err = -EBUSY;
736 0 : write_unlock(&resource_lock);
737 0 : return err;
738 : }
739 :
740 : EXPORT_SYMBOL(allocate_resource);
741 :
742 : /**
743 : * lookup_resource - find an existing resource by a resource start address
744 : * @root: root resource descriptor
745 : * @start: resource start address
746 : *
747 : * Returns a pointer to the resource if found, NULL otherwise
748 : */
749 0 : struct resource *lookup_resource(struct resource *root, resource_size_t start)
750 : {
751 : struct resource *res;
752 :
753 0 : read_lock(&resource_lock);
754 0 : for (res = root->child; res; res = res->sibling) {
755 0 : if (res->start == start)
756 : break;
757 : }
758 0 : read_unlock(&resource_lock);
759 :
760 0 : return res;
761 : }
762 :
763 : /*
764 : * Insert a resource into the resource tree. If successful, return NULL,
765 : * otherwise return the conflicting resource (compare to __request_resource())
766 : */
767 0 : static struct resource * __insert_resource(struct resource *parent, struct resource *new)
768 : {
769 : struct resource *first, *next;
770 :
771 : for (;; parent = first) {
772 0 : first = __request_resource(parent, new);
773 0 : if (!first)
774 : return first;
775 :
776 0 : if (first == parent)
777 : return first;
778 0 : if (WARN_ON(first == new)) /* duplicated insertion */
779 : return first;
780 :
781 0 : if ((first->start > new->start) || (first->end < new->end))
782 : break;
783 0 : if ((first->start == new->start) && (first->end == new->end))
784 : break;
785 : }
786 :
787 : for (next = first; ; next = next->sibling) {
788 : /* Partial overlap? Bad, and unfixable */
789 0 : if (next->start < new->start || next->end > new->end)
790 : return next;
791 0 : if (!next->sibling)
792 : break;
793 0 : if (next->sibling->start > new->end)
794 : break;
795 : }
796 :
797 0 : new->parent = parent;
798 0 : new->sibling = next->sibling;
799 0 : new->child = first;
800 :
801 0 : next->sibling = NULL;
802 0 : for (next = first; next; next = next->sibling)
803 0 : next->parent = new;
804 :
805 0 : if (parent->child == first) {
806 0 : parent->child = new;
807 : } else {
808 : next = parent->child;
809 0 : while (next->sibling != first)
810 : next = next->sibling;
811 0 : next->sibling = new;
812 : }
813 : return NULL;
814 : }
815 :
816 : /**
817 : * insert_resource_conflict - Inserts resource in the resource tree
818 : * @parent: parent of the new resource
819 : * @new: new resource to insert
820 : *
821 : * Returns 0 on success, conflict resource if the resource can't be inserted.
822 : *
823 : * This function is equivalent to request_resource_conflict when no conflict
824 : * happens. If a conflict happens, and the conflicting resources
825 : * entirely fit within the range of the new resource, then the new
826 : * resource is inserted and the conflicting resources become children of
827 : * the new resource.
828 : *
829 : * This function is intended for producers of resources, such as FW modules
830 : * and bus drivers.
831 : */
832 0 : struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
833 : {
834 : struct resource *conflict;
835 :
836 0 : write_lock(&resource_lock);
837 0 : conflict = __insert_resource(parent, new);
838 0 : write_unlock(&resource_lock);
839 0 : return conflict;
840 : }
841 :
842 : /**
843 : * insert_resource - Inserts a resource in the resource tree
844 : * @parent: parent of the new resource
845 : * @new: new resource to insert
846 : *
847 : * Returns 0 on success, -EBUSY if the resource can't be inserted.
848 : *
849 : * This function is intended for producers of resources, such as FW modules
850 : * and bus drivers.
851 : */
852 0 : int insert_resource(struct resource *parent, struct resource *new)
853 : {
854 : struct resource *conflict;
855 :
856 0 : conflict = insert_resource_conflict(parent, new);
857 0 : return conflict ? -EBUSY : 0;
858 : }
859 : EXPORT_SYMBOL_GPL(insert_resource);
860 :
861 : /**
862 : * insert_resource_expand_to_fit - Insert a resource into the resource tree
863 : * @root: root resource descriptor
864 : * @new: new resource to insert
865 : *
866 : * Insert a resource into the resource tree, possibly expanding it in order
867 : * to make it encompass any conflicting resources.
868 : */
869 0 : void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
870 : {
871 0 : if (new->parent)
872 : return;
873 :
874 0 : write_lock(&resource_lock);
875 0 : for (;;) {
876 : struct resource *conflict;
877 :
878 0 : conflict = __insert_resource(root, new);
879 0 : if (!conflict)
880 : break;
881 0 : if (conflict == root)
882 : break;
883 :
884 : /* Ok, expand resource to cover the conflict, then try again .. */
885 0 : if (conflict->start < new->start)
886 0 : new->start = conflict->start;
887 0 : if (conflict->end > new->end)
888 0 : new->end = conflict->end;
889 :
890 0 : printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
891 : }
892 0 : write_unlock(&resource_lock);
893 : }
894 :
895 : /**
896 : * remove_resource - Remove a resource in the resource tree
897 : * @old: resource to remove
898 : *
899 : * Returns 0 on success, -EINVAL if the resource is not valid.
900 : *
901 : * This function removes a resource previously inserted by insert_resource()
902 : * or insert_resource_conflict(), and moves the children (if any) up to
903 : * where they were before. insert_resource() and insert_resource_conflict()
904 : * insert a new resource, and move any conflicting resources down to the
905 : * children of the new resource.
906 : *
907 : * insert_resource(), insert_resource_conflict() and remove_resource() are
908 : * intended for producers of resources, such as FW modules and bus drivers.
909 : */
910 0 : int remove_resource(struct resource *old)
911 : {
912 : int retval;
913 :
914 0 : write_lock(&resource_lock);
915 0 : retval = __release_resource(old, false);
916 0 : write_unlock(&resource_lock);
917 0 : return retval;
918 : }
919 : EXPORT_SYMBOL_GPL(remove_resource);
920 :
921 0 : static int __adjust_resource(struct resource *res, resource_size_t start,
922 : resource_size_t size)
923 : {
924 0 : struct resource *tmp, *parent = res->parent;
925 0 : resource_size_t end = start + size - 1;
926 0 : int result = -EBUSY;
927 :
928 0 : if (!parent)
929 : goto skip;
930 :
931 0 : if ((start < parent->start) || (end > parent->end))
932 : goto out;
933 :
934 0 : if (res->sibling && (res->sibling->start <= end))
935 : goto out;
936 :
937 0 : tmp = parent->child;
938 0 : if (tmp != res) {
939 0 : while (tmp->sibling != res)
940 : tmp = tmp->sibling;
941 0 : if (start <= tmp->end)
942 : goto out;
943 : }
944 :
945 : skip:
946 0 : for (tmp = res->child; tmp; tmp = tmp->sibling)
947 0 : if ((tmp->start < start) || (tmp->end > end))
948 : goto out;
949 :
950 0 : res->start = start;
951 0 : res->end = end;
952 0 : result = 0;
953 :
954 : out:
955 0 : return result;
956 : }
957 :
958 : /**
959 : * adjust_resource - modify a resource's start and size
960 : * @res: resource to modify
961 : * @start: new start value
962 : * @size: new size
963 : *
964 : * Given an existing resource, change its start and size to match the
965 : * arguments. Returns 0 on success, -EBUSY if it can't fit.
966 : * Existing children of the resource are assumed to be immutable.
967 : */
968 0 : int adjust_resource(struct resource *res, resource_size_t start,
969 : resource_size_t size)
970 : {
971 : int result;
972 :
973 0 : write_lock(&resource_lock);
974 0 : result = __adjust_resource(res, start, size);
975 0 : write_unlock(&resource_lock);
976 0 : return result;
977 : }
978 : EXPORT_SYMBOL(adjust_resource);
979 :
980 : static void __init
981 0 : __reserve_region_with_split(struct resource *root, resource_size_t start,
982 : resource_size_t end, const char *name)
983 : {
984 0 : struct resource *parent = root;
985 : struct resource *conflict;
986 0 : struct resource *res = alloc_resource(GFP_ATOMIC);
987 0 : struct resource *next_res = NULL;
988 0 : int type = resource_type(root);
989 :
990 0 : if (!res)
991 : return;
992 :
993 0 : res->name = name;
994 0 : res->start = start;
995 0 : res->end = end;
996 0 : res->flags = type | IORESOURCE_BUSY;
997 0 : res->desc = IORES_DESC_NONE;
998 :
999 : while (1) {
1000 :
1001 0 : conflict = __request_resource(parent, res);
1002 0 : if (!conflict) {
1003 0 : if (!next_res)
1004 : break;
1005 0 : res = next_res;
1006 0 : next_res = NULL;
1007 0 : continue;
1008 : }
1009 :
1010 : /* conflict covered whole area */
1011 0 : if (conflict->start <= res->start &&
1012 0 : conflict->end >= res->end) {
1013 0 : free_resource(res);
1014 0 : WARN_ON(next_res);
1015 : break;
1016 : }
1017 :
1018 : /* failed, split and try again */
1019 0 : if (conflict->start > res->start) {
1020 0 : end = res->end;
1021 0 : res->end = conflict->start - 1;
1022 0 : if (conflict->end < end) {
1023 0 : next_res = alloc_resource(GFP_ATOMIC);
1024 0 : if (!next_res) {
1025 0 : free_resource(res);
1026 0 : break;
1027 : }
1028 0 : next_res->name = name;
1029 0 : next_res->start = conflict->end + 1;
1030 0 : next_res->end = end;
1031 0 : next_res->flags = type | IORESOURCE_BUSY;
1032 0 : next_res->desc = IORES_DESC_NONE;
1033 : }
1034 : } else {
1035 0 : res->start = conflict->end + 1;
1036 : }
1037 : }
1038 :
1039 : }
1040 :
1041 : void __init
1042 0 : reserve_region_with_split(struct resource *root, resource_size_t start,
1043 : resource_size_t end, const char *name)
1044 : {
1045 0 : int abort = 0;
1046 :
1047 0 : write_lock(&resource_lock);
1048 0 : if (root->start > start || root->end < end) {
1049 0 : pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
1050 : (unsigned long long)start, (unsigned long long)end,
1051 : root);
1052 0 : if (start > root->end || end < root->start)
1053 : abort = 1;
1054 : else {
1055 0 : if (end > root->end)
1056 0 : end = root->end;
1057 0 : if (start < root->start)
1058 0 : start = root->start;
1059 0 : pr_err("fixing request to [0x%llx-0x%llx]\n",
1060 : (unsigned long long)start,
1061 : (unsigned long long)end);
1062 : }
1063 0 : dump_stack();
1064 : }
1065 0 : if (!abort)
1066 0 : __reserve_region_with_split(root, start, end, name);
1067 0 : write_unlock(&resource_lock);
1068 0 : }
1069 :
1070 : /**
1071 : * resource_alignment - calculate resource's alignment
1072 : * @res: resource pointer
1073 : *
1074 : * Returns alignment on success, 0 (invalid alignment) on failure.
1075 : */
1076 0 : resource_size_t resource_alignment(struct resource *res)
1077 : {
1078 0 : switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
1079 : case IORESOURCE_SIZEALIGN:
1080 0 : return resource_size(res);
1081 : case IORESOURCE_STARTALIGN:
1082 0 : return res->start;
1083 : default:
1084 : return 0;
1085 : }
1086 : }
1087 :
1088 : /*
1089 : * This is compatibility stuff for IO resources.
1090 : *
1091 : * Note how this, unlike the above, knows about
1092 : * the IO flag meanings (busy etc).
1093 : *
1094 : * request_region creates a new busy region.
1095 : *
1096 : * release_region releases a matching busy region.
1097 : */
1098 :
1099 : static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
1100 :
1101 : static struct inode *iomem_inode;
1102 :
1103 : #ifdef CONFIG_IO_STRICT_DEVMEM
1104 : static void revoke_iomem(struct resource *res)
1105 : {
1106 : /* pairs with smp_store_release() in iomem_init_inode() */
1107 : struct inode *inode = smp_load_acquire(&iomem_inode);
1108 :
1109 : /*
1110 : * Check that the initialization has completed. Losing the race
1111 : * is ok because it means drivers are claiming resources before
1112 : * the fs_initcall level of init and prevent iomem_get_mapping users
1113 : * from establishing mappings.
1114 : */
1115 : if (!inode)
1116 : return;
1117 :
1118 : /*
1119 : * The expectation is that the driver has successfully marked
1120 : * the resource busy by this point, so devmem_is_allowed()
1121 : * should start returning false, however for performance this
1122 : * does not iterate the entire resource range.
1123 : */
1124 : if (devmem_is_allowed(PHYS_PFN(res->start)) &&
1125 : devmem_is_allowed(PHYS_PFN(res->end))) {
1126 : /*
1127 : * *cringe* iomem=relaxed says "go ahead, what's the
1128 : * worst that can happen?"
1129 : */
1130 : return;
1131 : }
1132 :
1133 : unmap_mapping_range(inode->i_mapping, res->start, resource_size(res), 1);
1134 : }
1135 : #else
1136 : static void revoke_iomem(struct resource *res) {}
1137 : #endif
1138 :
1139 0 : struct address_space *iomem_get_mapping(void)
1140 : {
1141 : /*
1142 : * This function is only called from file open paths, hence guaranteed
1143 : * that fs_initcalls have completed and no need to check for NULL. But
1144 : * since revoke_iomem can be called before the initcall we still need
1145 : * the barrier to appease checkers.
1146 : */
1147 0 : return smp_load_acquire(&iomem_inode)->i_mapping;
1148 : }
1149 :
1150 0 : static int __request_region_locked(struct resource *res, struct resource *parent,
1151 : resource_size_t start, resource_size_t n,
1152 : const char *name, int flags)
1153 : {
1154 0 : DECLARE_WAITQUEUE(wait, current);
1155 :
1156 0 : res->name = name;
1157 0 : res->start = start;
1158 0 : res->end = start + n - 1;
1159 :
1160 : for (;;) {
1161 : struct resource *conflict;
1162 :
1163 0 : res->flags = resource_type(parent) | resource_ext_type(parent);
1164 0 : res->flags |= IORESOURCE_BUSY | flags;
1165 0 : res->desc = parent->desc;
1166 :
1167 0 : conflict = __request_resource(parent, res);
1168 0 : if (!conflict)
1169 : break;
1170 : /*
1171 : * mm/hmm.c reserves physical addresses which then
1172 : * become unavailable to other users. Conflicts are
1173 : * not expected. Warn to aid debugging if encountered.
1174 : */
1175 0 : if (conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) {
1176 0 : pr_warn("Unaddressable device %s %pR conflicts with %pR",
1177 : conflict->name, conflict, res);
1178 : }
1179 0 : if (conflict != parent) {
1180 0 : if (!(conflict->flags & IORESOURCE_BUSY)) {
1181 0 : parent = conflict;
1182 0 : continue;
1183 : }
1184 : }
1185 0 : if (conflict->flags & flags & IORESOURCE_MUXED) {
1186 0 : add_wait_queue(&muxed_resource_wait, &wait);
1187 0 : write_unlock(&resource_lock);
1188 0 : set_current_state(TASK_UNINTERRUPTIBLE);
1189 0 : schedule();
1190 0 : remove_wait_queue(&muxed_resource_wait, &wait);
1191 0 : write_lock(&resource_lock);
1192 0 : continue;
1193 : }
1194 : /* Uhhuh, that didn't work out.. */
1195 : return -EBUSY;
1196 : }
1197 :
1198 : return 0;
1199 : }
1200 :
1201 : /**
1202 : * __request_region - create a new busy resource region
1203 : * @parent: parent resource descriptor
1204 : * @start: resource start address
1205 : * @n: resource region size
1206 : * @name: reserving caller's ID string
1207 : * @flags: IO resource flags
1208 : */
1209 0 : struct resource *__request_region(struct resource *parent,
1210 : resource_size_t start, resource_size_t n,
1211 : const char *name, int flags)
1212 : {
1213 0 : struct resource *res = alloc_resource(GFP_KERNEL);
1214 : int ret;
1215 :
1216 0 : if (!res)
1217 : return NULL;
1218 :
1219 0 : write_lock(&resource_lock);
1220 0 : ret = __request_region_locked(res, parent, start, n, name, flags);
1221 0 : write_unlock(&resource_lock);
1222 :
1223 0 : if (ret) {
1224 0 : free_resource(res);
1225 0 : return NULL;
1226 : }
1227 :
1228 : if (parent == &iomem_resource)
1229 : revoke_iomem(res);
1230 :
1231 : return res;
1232 : }
1233 : EXPORT_SYMBOL(__request_region);
1234 :
1235 : /**
1236 : * __release_region - release a previously reserved resource region
1237 : * @parent: parent resource descriptor
1238 : * @start: resource start address
1239 : * @n: resource region size
1240 : *
1241 : * The described resource region must match a currently busy region.
1242 : */
1243 0 : void __release_region(struct resource *parent, resource_size_t start,
1244 : resource_size_t n)
1245 : {
1246 : struct resource **p;
1247 : resource_size_t end;
1248 :
1249 0 : p = &parent->child;
1250 0 : end = start + n - 1;
1251 :
1252 0 : write_lock(&resource_lock);
1253 :
1254 : for (;;) {
1255 0 : struct resource *res = *p;
1256 :
1257 0 : if (!res)
1258 : break;
1259 0 : if (res->start <= start && res->end >= end) {
1260 0 : if (!(res->flags & IORESOURCE_BUSY)) {
1261 0 : p = &res->child;
1262 0 : continue;
1263 : }
1264 0 : if (res->start != start || res->end != end)
1265 : break;
1266 0 : *p = res->sibling;
1267 0 : write_unlock(&resource_lock);
1268 0 : if (res->flags & IORESOURCE_MUXED)
1269 0 : wake_up(&muxed_resource_wait);
1270 0 : free_resource(res);
1271 0 : return;
1272 : }
1273 0 : p = &res->sibling;
1274 : }
1275 :
1276 0 : write_unlock(&resource_lock);
1277 :
1278 0 : printk(KERN_WARNING "Trying to free nonexistent resource "
1279 : "<%016llx-%016llx>\n", (unsigned long long)start,
1280 : (unsigned long long)end);
1281 : }
1282 : EXPORT_SYMBOL(__release_region);
1283 :
1284 : #ifdef CONFIG_MEMORY_HOTREMOVE
1285 : /**
1286 : * release_mem_region_adjustable - release a previously reserved memory region
1287 : * @start: resource start address
1288 : * @size: resource region size
1289 : *
1290 : * This interface is intended for memory hot-delete. The requested region
1291 : * is released from a currently busy memory resource. The requested region
1292 : * must either match exactly or fit into a single busy resource entry. In
1293 : * the latter case, the remaining resource is adjusted accordingly.
1294 : * Existing children of the busy memory resource must be immutable in the
1295 : * request.
1296 : *
1297 : * Note:
1298 : * - Additional release conditions, such as overlapping region, can be
1299 : * supported after they are confirmed as valid cases.
1300 : * - When a busy memory resource gets split into two entries, the code
1301 : * assumes that all children remain in the lower address entry for
1302 : * simplicity. Enhance this logic when necessary.
1303 : */
1304 : void release_mem_region_adjustable(resource_size_t start, resource_size_t size)
1305 : {
1306 : struct resource *parent = &iomem_resource;
1307 : struct resource *new_res = NULL;
1308 : bool alloc_nofail = false;
1309 : struct resource **p;
1310 : struct resource *res;
1311 : resource_size_t end;
1312 :
1313 : end = start + size - 1;
1314 : if (WARN_ON_ONCE((start < parent->start) || (end > parent->end)))
1315 : return;
1316 :
1317 : /*
1318 : * We free up quite a lot of memory on memory hotunplug (esp., memap),
1319 : * just before releasing the region. This is highly unlikely to
1320 : * fail - let's play save and make it never fail as the caller cannot
1321 : * perform any error handling (e.g., trying to re-add memory will fail
1322 : * similarly).
1323 : */
1324 : retry:
1325 : new_res = alloc_resource(GFP_KERNEL | (alloc_nofail ? __GFP_NOFAIL : 0));
1326 :
1327 : p = &parent->child;
1328 : write_lock(&resource_lock);
1329 :
1330 : while ((res = *p)) {
1331 : if (res->start >= end)
1332 : break;
1333 :
1334 : /* look for the next resource if it does not fit into */
1335 : if (res->start > start || res->end < end) {
1336 : p = &res->sibling;
1337 : continue;
1338 : }
1339 :
1340 : /*
1341 : * All memory regions added from memory-hotplug path have the
1342 : * flag IORESOURCE_SYSTEM_RAM. If the resource does not have
1343 : * this flag, we know that we are dealing with a resource coming
1344 : * from HMM/devm. HMM/devm use another mechanism to add/release
1345 : * a resource. This goes via devm_request_mem_region and
1346 : * devm_release_mem_region.
1347 : * HMM/devm take care to release their resources when they want,
1348 : * so if we are dealing with them, let us just back off here.
1349 : */
1350 : if (!(res->flags & IORESOURCE_SYSRAM)) {
1351 : break;
1352 : }
1353 :
1354 : if (!(res->flags & IORESOURCE_MEM))
1355 : break;
1356 :
1357 : if (!(res->flags & IORESOURCE_BUSY)) {
1358 : p = &res->child;
1359 : continue;
1360 : }
1361 :
1362 : /* found the target resource; let's adjust accordingly */
1363 : if (res->start == start && res->end == end) {
1364 : /* free the whole entry */
1365 : *p = res->sibling;
1366 : free_resource(res);
1367 : } else if (res->start == start && res->end != end) {
1368 : /* adjust the start */
1369 : WARN_ON_ONCE(__adjust_resource(res, end + 1,
1370 : res->end - end));
1371 : } else if (res->start != start && res->end == end) {
1372 : /* adjust the end */
1373 : WARN_ON_ONCE(__adjust_resource(res, res->start,
1374 : start - res->start));
1375 : } else {
1376 : /* split into two entries - we need a new resource */
1377 : if (!new_res) {
1378 : new_res = alloc_resource(GFP_ATOMIC);
1379 : if (!new_res) {
1380 : alloc_nofail = true;
1381 : write_unlock(&resource_lock);
1382 : goto retry;
1383 : }
1384 : }
1385 : new_res->name = res->name;
1386 : new_res->start = end + 1;
1387 : new_res->end = res->end;
1388 : new_res->flags = res->flags;
1389 : new_res->desc = res->desc;
1390 : new_res->parent = res->parent;
1391 : new_res->sibling = res->sibling;
1392 : new_res->child = NULL;
1393 :
1394 : if (WARN_ON_ONCE(__adjust_resource(res, res->start,
1395 : start - res->start)))
1396 : break;
1397 : res->sibling = new_res;
1398 : new_res = NULL;
1399 : }
1400 :
1401 : break;
1402 : }
1403 :
1404 : write_unlock(&resource_lock);
1405 : free_resource(new_res);
1406 : }
1407 : #endif /* CONFIG_MEMORY_HOTREMOVE */
1408 :
1409 : #ifdef CONFIG_MEMORY_HOTPLUG
1410 : static bool system_ram_resources_mergeable(struct resource *r1,
1411 : struct resource *r2)
1412 : {
1413 : /* We assume either r1 or r2 is IORESOURCE_SYSRAM_MERGEABLE. */
1414 : return r1->flags == r2->flags && r1->end + 1 == r2->start &&
1415 : r1->name == r2->name && r1->desc == r2->desc &&
1416 : !r1->child && !r2->child;
1417 : }
1418 :
1419 : /**
1420 : * merge_system_ram_resource - mark the System RAM resource mergeable and try to
1421 : * merge it with adjacent, mergeable resources
1422 : * @res: resource descriptor
1423 : *
1424 : * This interface is intended for memory hotplug, whereby lots of contiguous
1425 : * system ram resources are added (e.g., via add_memory*()) by a driver, and
1426 : * the actual resource boundaries are not of interest (e.g., it might be
1427 : * relevant for DIMMs). Only resources that are marked mergeable, that have the
1428 : * same parent, and that don't have any children are considered. All mergeable
1429 : * resources must be immutable during the request.
1430 : *
1431 : * Note:
1432 : * - The caller has to make sure that no pointers to resources that are
1433 : * marked mergeable are used anymore after this call - the resource might
1434 : * be freed and the pointer might be stale!
1435 : * - release_mem_region_adjustable() will split on demand on memory hotunplug
1436 : */
1437 : void merge_system_ram_resource(struct resource *res)
1438 : {
1439 : const unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
1440 : struct resource *cur;
1441 :
1442 : if (WARN_ON_ONCE((res->flags & flags) != flags))
1443 : return;
1444 :
1445 : write_lock(&resource_lock);
1446 : res->flags |= IORESOURCE_SYSRAM_MERGEABLE;
1447 :
1448 : /* Try to merge with next item in the list. */
1449 : cur = res->sibling;
1450 : if (cur && system_ram_resources_mergeable(res, cur)) {
1451 : res->end = cur->end;
1452 : res->sibling = cur->sibling;
1453 : free_resource(cur);
1454 : }
1455 :
1456 : /* Try to merge with previous item in the list. */
1457 : cur = res->parent->child;
1458 : while (cur && cur->sibling != res)
1459 : cur = cur->sibling;
1460 : if (cur && system_ram_resources_mergeable(cur, res)) {
1461 : cur->end = res->end;
1462 : cur->sibling = res->sibling;
1463 : free_resource(res);
1464 : }
1465 : write_unlock(&resource_lock);
1466 : }
1467 : #endif /* CONFIG_MEMORY_HOTPLUG */
1468 :
1469 : /*
1470 : * Managed region resource
1471 : */
1472 0 : static void devm_resource_release(struct device *dev, void *ptr)
1473 : {
1474 0 : struct resource **r = ptr;
1475 :
1476 0 : release_resource(*r);
1477 0 : }
1478 :
1479 : /**
1480 : * devm_request_resource() - request and reserve an I/O or memory resource
1481 : * @dev: device for which to request the resource
1482 : * @root: root of the resource tree from which to request the resource
1483 : * @new: descriptor of the resource to request
1484 : *
1485 : * This is a device-managed version of request_resource(). There is usually
1486 : * no need to release resources requested by this function explicitly since
1487 : * that will be taken care of when the device is unbound from its driver.
1488 : * If for some reason the resource needs to be released explicitly, because
1489 : * of ordering issues for example, drivers must call devm_release_resource()
1490 : * rather than the regular release_resource().
1491 : *
1492 : * When a conflict is detected between any existing resources and the newly
1493 : * requested resource, an error message will be printed.
1494 : *
1495 : * Returns 0 on success or a negative error code on failure.
1496 : */
1497 0 : int devm_request_resource(struct device *dev, struct resource *root,
1498 : struct resource *new)
1499 : {
1500 : struct resource *conflict, **ptr;
1501 :
1502 0 : ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL);
1503 0 : if (!ptr)
1504 : return -ENOMEM;
1505 :
1506 0 : *ptr = new;
1507 :
1508 0 : conflict = request_resource_conflict(root, new);
1509 0 : if (conflict) {
1510 0 : dev_err(dev, "resource collision: %pR conflicts with %s %pR\n",
1511 : new, conflict->name, conflict);
1512 0 : devres_free(ptr);
1513 0 : return -EBUSY;
1514 : }
1515 :
1516 0 : devres_add(dev, ptr);
1517 0 : return 0;
1518 : }
1519 : EXPORT_SYMBOL(devm_request_resource);
1520 :
1521 0 : static int devm_resource_match(struct device *dev, void *res, void *data)
1522 : {
1523 0 : struct resource **ptr = res;
1524 :
1525 0 : return *ptr == data;
1526 : }
1527 :
1528 : /**
1529 : * devm_release_resource() - release a previously requested resource
1530 : * @dev: device for which to release the resource
1531 : * @new: descriptor of the resource to release
1532 : *
1533 : * Releases a resource previously requested using devm_request_resource().
1534 : */
1535 0 : void devm_release_resource(struct device *dev, struct resource *new)
1536 : {
1537 0 : WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match,
1538 : new));
1539 0 : }
1540 : EXPORT_SYMBOL(devm_release_resource);
1541 :
1542 : struct region_devres {
1543 : struct resource *parent;
1544 : resource_size_t start;
1545 : resource_size_t n;
1546 : };
1547 :
1548 0 : static void devm_region_release(struct device *dev, void *res)
1549 : {
1550 0 : struct region_devres *this = res;
1551 :
1552 0 : __release_region(this->parent, this->start, this->n);
1553 0 : }
1554 :
1555 0 : static int devm_region_match(struct device *dev, void *res, void *match_data)
1556 : {
1557 0 : struct region_devres *this = res, *match = match_data;
1558 :
1559 0 : return this->parent == match->parent &&
1560 0 : this->start == match->start && this->n == match->n;
1561 : }
1562 :
1563 : struct resource *
1564 0 : __devm_request_region(struct device *dev, struct resource *parent,
1565 : resource_size_t start, resource_size_t n, const char *name)
1566 : {
1567 0 : struct region_devres *dr = NULL;
1568 : struct resource *res;
1569 :
1570 0 : dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
1571 : GFP_KERNEL);
1572 0 : if (!dr)
1573 : return NULL;
1574 :
1575 0 : dr->parent = parent;
1576 0 : dr->start = start;
1577 0 : dr->n = n;
1578 :
1579 0 : res = __request_region(parent, start, n, name, 0);
1580 0 : if (res)
1581 0 : devres_add(dev, dr);
1582 : else
1583 0 : devres_free(dr);
1584 :
1585 : return res;
1586 : }
1587 : EXPORT_SYMBOL(__devm_request_region);
1588 :
1589 0 : void __devm_release_region(struct device *dev, struct resource *parent,
1590 : resource_size_t start, resource_size_t n)
1591 : {
1592 0 : struct region_devres match_data = { parent, start, n };
1593 :
1594 0 : __release_region(parent, start, n);
1595 0 : WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
1596 : &match_data));
1597 0 : }
1598 : EXPORT_SYMBOL(__devm_release_region);
1599 :
1600 : /*
1601 : * Reserve I/O ports or memory based on "reserve=" kernel parameter.
1602 : */
1603 : #define MAXRESERVE 4
1604 0 : static int __init reserve_setup(char *str)
1605 : {
1606 : static int reserved;
1607 : static struct resource reserve[MAXRESERVE];
1608 :
1609 0 : for (;;) {
1610 : unsigned int io_start, io_num;
1611 0 : int x = reserved;
1612 : struct resource *parent;
1613 :
1614 0 : if (get_option(&str, &io_start) != 2)
1615 : break;
1616 0 : if (get_option(&str, &io_num) == 0)
1617 : break;
1618 0 : if (x < MAXRESERVE) {
1619 0 : struct resource *res = reserve + x;
1620 :
1621 : /*
1622 : * If the region starts below 0x10000, we assume it's
1623 : * I/O port space; otherwise assume it's memory.
1624 : */
1625 0 : if (io_start < 0x10000) {
1626 0 : res->flags = IORESOURCE_IO;
1627 0 : parent = &ioport_resource;
1628 : } else {
1629 0 : res->flags = IORESOURCE_MEM;
1630 0 : parent = &iomem_resource;
1631 : }
1632 0 : res->name = "reserved";
1633 0 : res->start = io_start;
1634 0 : res->end = io_start + io_num - 1;
1635 0 : res->flags |= IORESOURCE_BUSY;
1636 0 : res->desc = IORES_DESC_NONE;
1637 0 : res->child = NULL;
1638 0 : if (request_resource(parent, res) == 0)
1639 0 : reserved = x+1;
1640 : }
1641 : }
1642 0 : return 1;
1643 : }
1644 : __setup("reserve=", reserve_setup);
1645 :
1646 : /*
1647 : * Check if the requested addr and size spans more than any slot in the
1648 : * iomem resource tree.
1649 : */
1650 0 : int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
1651 : {
1652 0 : struct resource *p = &iomem_resource;
1653 0 : int err = 0;
1654 : loff_t l;
1655 :
1656 0 : read_lock(&resource_lock);
1657 0 : for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1658 : /*
1659 : * We can probably skip the resources without
1660 : * IORESOURCE_IO attribute?
1661 : */
1662 0 : if (p->start >= addr + size)
1663 0 : continue;
1664 0 : if (p->end < addr)
1665 0 : continue;
1666 0 : if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
1667 0 : PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
1668 0 : continue;
1669 : /*
1670 : * if a resource is "BUSY", it's not a hardware resource
1671 : * but a driver mapping of such a resource; we don't want
1672 : * to warn for those; some drivers legitimately map only
1673 : * partial hardware resources. (example: vesafb)
1674 : */
1675 0 : if (p->flags & IORESOURCE_BUSY)
1676 0 : continue;
1677 :
1678 0 : printk(KERN_WARNING "resource sanity check: requesting [mem %#010llx-%#010llx], which spans more than %s %pR\n",
1679 : (unsigned long long)addr,
1680 : (unsigned long long)(addr + size - 1),
1681 : p->name, p);
1682 0 : err = -1;
1683 0 : break;
1684 : }
1685 0 : read_unlock(&resource_lock);
1686 :
1687 0 : return err;
1688 : }
1689 :
1690 : #ifdef CONFIG_STRICT_DEVMEM
1691 : static int strict_iomem_checks = 1;
1692 : #else
1693 : static int strict_iomem_checks;
1694 : #endif
1695 :
1696 : /*
1697 : * Check if an address is exclusive to the kernel and must not be mapped to
1698 : * user space, for example, via /dev/mem.
1699 : *
1700 : * Returns true if exclusive to the kernel, otherwise returns false.
1701 : */
1702 0 : bool iomem_is_exclusive(u64 addr)
1703 : {
1704 0 : const unsigned int exclusive_system_ram = IORESOURCE_SYSTEM_RAM |
1705 : IORESOURCE_EXCLUSIVE;
1706 0 : bool skip_children = false, err = false;
1707 0 : int size = PAGE_SIZE;
1708 : struct resource *p;
1709 :
1710 0 : addr = addr & PAGE_MASK;
1711 :
1712 0 : read_lock(&resource_lock);
1713 0 : for_each_resource(&iomem_resource, p, skip_children) {
1714 0 : if (p->start >= addr + size)
1715 : break;
1716 0 : if (p->end < addr) {
1717 0 : skip_children = true;
1718 0 : continue;
1719 : }
1720 0 : skip_children = false;
1721 :
1722 : /*
1723 : * IORESOURCE_SYSTEM_RAM resources are exclusive if
1724 : * IORESOURCE_EXCLUSIVE is set, even if they
1725 : * are not busy and even if "iomem=relaxed" is set. The
1726 : * responsible driver dynamically adds/removes system RAM within
1727 : * such an area and uncontrolled access is dangerous.
1728 : */
1729 0 : if ((p->flags & exclusive_system_ram) == exclusive_system_ram) {
1730 : err = true;
1731 : break;
1732 : }
1733 :
1734 : /*
1735 : * A resource is exclusive if IORESOURCE_EXCLUSIVE is set
1736 : * or CONFIG_IO_STRICT_DEVMEM is enabled and the
1737 : * resource is busy.
1738 : */
1739 0 : if (!strict_iomem_checks || !(p->flags & IORESOURCE_BUSY))
1740 0 : continue;
1741 0 : if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM)
1742 0 : || p->flags & IORESOURCE_EXCLUSIVE) {
1743 : err = true;
1744 : break;
1745 : }
1746 : }
1747 0 : read_unlock(&resource_lock);
1748 :
1749 0 : return err;
1750 : }
1751 :
1752 0 : struct resource_entry *resource_list_create_entry(struct resource *res,
1753 : size_t extra_size)
1754 : {
1755 : struct resource_entry *entry;
1756 :
1757 0 : entry = kzalloc(sizeof(*entry) + extra_size, GFP_KERNEL);
1758 0 : if (entry) {
1759 0 : INIT_LIST_HEAD(&entry->node);
1760 0 : entry->res = res ? res : &entry->__res;
1761 : }
1762 :
1763 0 : return entry;
1764 : }
1765 : EXPORT_SYMBOL(resource_list_create_entry);
1766 :
1767 0 : void resource_list_free(struct list_head *head)
1768 : {
1769 : struct resource_entry *entry, *tmp;
1770 :
1771 0 : list_for_each_entry_safe(entry, tmp, head, node)
1772 0 : resource_list_destroy_entry(entry);
1773 0 : }
1774 : EXPORT_SYMBOL(resource_list_free);
1775 :
1776 : #ifdef CONFIG_DEVICE_PRIVATE
1777 : static struct resource *__request_free_mem_region(struct device *dev,
1778 : struct resource *base, unsigned long size, const char *name)
1779 : {
1780 : resource_size_t end, addr;
1781 : struct resource *res;
1782 : struct region_devres *dr = NULL;
1783 :
1784 : size = ALIGN(size, 1UL << PA_SECTION_SHIFT);
1785 : end = min_t(unsigned long, base->end, (1UL << MAX_PHYSMEM_BITS) - 1);
1786 : addr = end - size + 1UL;
1787 :
1788 : res = alloc_resource(GFP_KERNEL);
1789 : if (!res)
1790 : return ERR_PTR(-ENOMEM);
1791 :
1792 : if (dev) {
1793 : dr = devres_alloc(devm_region_release,
1794 : sizeof(struct region_devres), GFP_KERNEL);
1795 : if (!dr) {
1796 : free_resource(res);
1797 : return ERR_PTR(-ENOMEM);
1798 : }
1799 : }
1800 :
1801 : write_lock(&resource_lock);
1802 : for (; addr > size && addr >= base->start; addr -= size) {
1803 : if (__region_intersects(addr, size, 0, IORES_DESC_NONE) !=
1804 : REGION_DISJOINT)
1805 : continue;
1806 :
1807 : if (__request_region_locked(res, &iomem_resource, addr, size,
1808 : name, 0))
1809 : break;
1810 :
1811 : if (dev) {
1812 : dr->parent = &iomem_resource;
1813 : dr->start = addr;
1814 : dr->n = size;
1815 : devres_add(dev, dr);
1816 : }
1817 :
1818 : res->desc = IORES_DESC_DEVICE_PRIVATE_MEMORY;
1819 : write_unlock(&resource_lock);
1820 :
1821 : /*
1822 : * A driver is claiming this region so revoke any mappings.
1823 : */
1824 : revoke_iomem(res);
1825 : return res;
1826 : }
1827 : write_unlock(&resource_lock);
1828 :
1829 : free_resource(res);
1830 : if (dr)
1831 : devres_free(dr);
1832 :
1833 : return ERR_PTR(-ERANGE);
1834 : }
1835 :
1836 : /**
1837 : * devm_request_free_mem_region - find free region for device private memory
1838 : *
1839 : * @dev: device struct to bind the resource to
1840 : * @size: size in bytes of the device memory to add
1841 : * @base: resource tree to look in
1842 : *
1843 : * This function tries to find an empty range of physical address big enough to
1844 : * contain the new resource, so that it can later be hotplugged as ZONE_DEVICE
1845 : * memory, which in turn allocates struct pages.
1846 : */
1847 : struct resource *devm_request_free_mem_region(struct device *dev,
1848 : struct resource *base, unsigned long size)
1849 : {
1850 : return __request_free_mem_region(dev, base, size, dev_name(dev));
1851 : }
1852 : EXPORT_SYMBOL_GPL(devm_request_free_mem_region);
1853 :
1854 : struct resource *request_free_mem_region(struct resource *base,
1855 : unsigned long size, const char *name)
1856 : {
1857 : return __request_free_mem_region(NULL, base, size, name);
1858 : }
1859 : EXPORT_SYMBOL_GPL(request_free_mem_region);
1860 :
1861 : #endif /* CONFIG_DEVICE_PRIVATE */
1862 :
1863 0 : static int __init strict_iomem(char *str)
1864 : {
1865 0 : if (strstr(str, "relaxed"))
1866 0 : strict_iomem_checks = 0;
1867 0 : if (strstr(str, "strict"))
1868 0 : strict_iomem_checks = 1;
1869 0 : return 1;
1870 : }
1871 :
1872 1 : static int iomem_fs_init_fs_context(struct fs_context *fc)
1873 : {
1874 1 : return init_pseudo(fc, DEVMEM_MAGIC) ? 0 : -ENOMEM;
1875 : }
1876 :
1877 : static struct file_system_type iomem_fs_type = {
1878 : .name = "iomem",
1879 : .owner = THIS_MODULE,
1880 : .init_fs_context = iomem_fs_init_fs_context,
1881 : .kill_sb = kill_anon_super,
1882 : };
1883 :
1884 1 : static int __init iomem_init_inode(void)
1885 : {
1886 : static struct vfsmount *iomem_vfs_mount;
1887 : static int iomem_fs_cnt;
1888 : struct inode *inode;
1889 : int rc;
1890 :
1891 1 : rc = simple_pin_fs(&iomem_fs_type, &iomem_vfs_mount, &iomem_fs_cnt);
1892 1 : if (rc < 0) {
1893 0 : pr_err("Cannot mount iomem pseudo filesystem: %d\n", rc);
1894 0 : return rc;
1895 : }
1896 :
1897 1 : inode = alloc_anon_inode(iomem_vfs_mount->mnt_sb);
1898 1 : if (IS_ERR(inode)) {
1899 0 : rc = PTR_ERR(inode);
1900 0 : pr_err("Cannot allocate inode for iomem: %d\n", rc);
1901 0 : simple_release_fs(&iomem_vfs_mount, &iomem_fs_cnt);
1902 0 : return rc;
1903 : }
1904 :
1905 : /*
1906 : * Publish iomem revocation inode initialized.
1907 : * Pairs with smp_load_acquire() in revoke_iomem().
1908 : */
1909 1 : smp_store_release(&iomem_inode, inode);
1910 :
1911 1 : return 0;
1912 : }
1913 :
1914 : fs_initcall(iomem_init_inode);
1915 :
1916 : __setup("iomem=", strict_iomem);
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