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 3 : static struct resource * __request_resource(struct resource *root, struct resource *new)
172 : {
173 3 : resource_size_t start = new->start;
174 3 : resource_size_t end = new->end;
175 : struct resource *tmp, **p;
176 :
177 3 : if (end < start)
178 : return root;
179 3 : if (start < root->start)
180 : return root;
181 3 : if (end > root->end)
182 : return root;
183 3 : p = &root->child;
184 : for (;;) {
185 5 : tmp = *p;
186 4 : if (!tmp || tmp->start > end) {
187 3 : new->sibling = tmp;
188 3 : *p = new;
189 3 : new->parent = root;
190 3 : 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 3 : write_lock(&resource_lock);
270 3 : conflict = __request_resource(root, new);
271 3 : 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 3 : int request_resource(struct resource *root, struct resource *new)
283 : {
284 : struct resource *conflict;
285 :
286 3 : conflict = request_resource_conflict(root, new);
287 3 : 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(struct resource *parent, resource_size_t start,
493 : size_t size, unsigned long flags,
494 : unsigned long desc)
495 : {
496 : struct resource res;
497 0 : int type = 0; int other = 0;
498 : struct resource *p;
499 :
500 0 : res.start = start;
501 0 : res.end = start + size - 1;
502 :
503 0 : for (p = parent->child; p ; p = p->sibling) {
504 0 : bool is_type = (((p->flags & flags) == flags) &&
505 0 : ((desc == IORES_DESC_NONE) ||
506 0 : (desc == p->desc)));
507 :
508 0 : if (resource_overlaps(p, &res))
509 0 : is_type ? type++ : other++;
510 : }
511 :
512 0 : if (type == 0)
513 : return REGION_DISJOINT;
514 :
515 0 : if (other == 0)
516 : return REGION_INTERSECTS;
517 :
518 : return REGION_MIXED;
519 : }
520 :
521 : /**
522 : * region_intersects() - determine intersection of region with known resources
523 : * @start: region start address
524 : * @size: size of region
525 : * @flags: flags of resource (in iomem_resource)
526 : * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE
527 : *
528 : * Check if the specified region partially overlaps or fully eclipses a
529 : * resource identified by @flags and @desc (optional with IORES_DESC_NONE).
530 : * Return REGION_DISJOINT if the region does not overlap @flags/@desc,
531 : * return REGION_MIXED if the region overlaps @flags/@desc and another
532 : * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc
533 : * and no other defined resource. Note that REGION_INTERSECTS is also
534 : * returned in the case when the specified region overlaps RAM and undefined
535 : * memory holes.
536 : *
537 : * region_intersect() is used by memory remapping functions to ensure
538 : * the user is not remapping RAM and is a vast speed up over walking
539 : * through the resource table page by page.
540 : */
541 0 : int region_intersects(resource_size_t start, size_t size, unsigned long flags,
542 : unsigned long desc)
543 : {
544 : int ret;
545 :
546 0 : read_lock(&resource_lock);
547 0 : ret = __region_intersects(&iomem_resource, start, size, flags, desc);
548 0 : read_unlock(&resource_lock);
549 :
550 0 : return ret;
551 : }
552 : EXPORT_SYMBOL_GPL(region_intersects);
553 :
554 0 : void __weak arch_remove_reservations(struct resource *avail)
555 : {
556 0 : }
557 :
558 0 : static resource_size_t simple_align_resource(void *data,
559 : const struct resource *avail,
560 : resource_size_t size,
561 : resource_size_t align)
562 : {
563 0 : return avail->start;
564 : }
565 :
566 : static void resource_clip(struct resource *res, resource_size_t min,
567 : resource_size_t max)
568 : {
569 0 : if (res->start < min)
570 0 : res->start = min;
571 0 : if (res->end > max)
572 0 : res->end = max;
573 : }
574 :
575 : /*
576 : * Find empty slot in the resource tree with the given range and
577 : * alignment constraints
578 : */
579 0 : static int __find_resource(struct resource *root, struct resource *old,
580 : struct resource *new,
581 : resource_size_t size,
582 : struct resource_constraint *constraint)
583 : {
584 0 : struct resource *this = root->child;
585 0 : struct resource tmp = *new, avail, alloc;
586 :
587 0 : tmp.start = root->start;
588 : /*
589 : * Skip past an allocated resource that starts at 0, since the assignment
590 : * of this->start - 1 to tmp->end below would cause an underflow.
591 : */
592 0 : if (this && this->start == root->start) {
593 0 : tmp.start = (this == old) ? old->start : this->end + 1;
594 0 : this = this->sibling;
595 : }
596 : for(;;) {
597 0 : if (this)
598 0 : tmp.end = (this == old) ? this->end : this->start - 1;
599 : else
600 0 : tmp.end = root->end;
601 :
602 0 : if (tmp.end < tmp.start)
603 : goto next;
604 :
605 0 : resource_clip(&tmp, constraint->min, constraint->max);
606 0 : arch_remove_reservations(&tmp);
607 :
608 : /* Check for overflow after ALIGN() */
609 0 : avail.start = ALIGN(tmp.start, constraint->align);
610 0 : avail.end = tmp.end;
611 0 : avail.flags = new->flags & ~IORESOURCE_UNSET;
612 0 : if (avail.start >= tmp.start) {
613 0 : alloc.flags = avail.flags;
614 0 : alloc.start = constraint->alignf(constraint->alignf_data, &avail,
615 : size, constraint->align);
616 0 : alloc.end = alloc.start + size - 1;
617 0 : if (alloc.start <= alloc.end &&
618 0 : resource_contains(&avail, &alloc)) {
619 0 : new->start = alloc.start;
620 0 : new->end = alloc.end;
621 0 : return 0;
622 : }
623 : }
624 :
625 0 : next: if (!this || this->end == root->end)
626 : break;
627 :
628 0 : if (this != old)
629 0 : tmp.start = this->end + 1;
630 0 : this = this->sibling;
631 : }
632 : return -EBUSY;
633 : }
634 :
635 : /*
636 : * Find empty slot in the resource tree given range and alignment.
637 : */
638 : static int find_resource(struct resource *root, struct resource *new,
639 : resource_size_t size,
640 : struct resource_constraint *constraint)
641 : {
642 0 : return __find_resource(root, NULL, new, size, constraint);
643 : }
644 :
645 : /**
646 : * reallocate_resource - allocate a slot in the resource tree given range & alignment.
647 : * The resource will be relocated if the new size cannot be reallocated in the
648 : * current location.
649 : *
650 : * @root: root resource descriptor
651 : * @old: resource descriptor desired by caller
652 : * @newsize: new size of the resource descriptor
653 : * @constraint: the size and alignment constraints to be met.
654 : */
655 0 : static int reallocate_resource(struct resource *root, struct resource *old,
656 : resource_size_t newsize,
657 : struct resource_constraint *constraint)
658 : {
659 0 : int err=0;
660 0 : struct resource new = *old;
661 : struct resource *conflict;
662 :
663 0 : write_lock(&resource_lock);
664 :
665 0 : if ((err = __find_resource(root, old, &new, newsize, constraint)))
666 : goto out;
667 :
668 0 : if (resource_contains(&new, old)) {
669 0 : old->start = new.start;
670 0 : old->end = new.end;
671 0 : goto out;
672 : }
673 :
674 0 : if (old->child) {
675 : err = -EBUSY;
676 : goto out;
677 : }
678 :
679 0 : if (resource_contains(old, &new)) {
680 0 : old->start = new.start;
681 0 : old->end = new.end;
682 : } else {
683 0 : __release_resource(old, true);
684 0 : *old = new;
685 0 : conflict = __request_resource(root, old);
686 0 : BUG_ON(conflict);
687 : }
688 : out:
689 0 : write_unlock(&resource_lock);
690 0 : return err;
691 : }
692 :
693 :
694 : /**
695 : * allocate_resource - allocate empty slot in the resource tree given range & alignment.
696 : * The resource will be reallocated with a new size if it was already allocated
697 : * @root: root resource descriptor
698 : * @new: resource descriptor desired by caller
699 : * @size: requested resource region size
700 : * @min: minimum boundary to allocate
701 : * @max: maximum boundary to allocate
702 : * @align: alignment requested, in bytes
703 : * @alignf: alignment function, optional, called if not NULL
704 : * @alignf_data: arbitrary data to pass to the @alignf function
705 : */
706 0 : int allocate_resource(struct resource *root, struct resource *new,
707 : resource_size_t size, resource_size_t min,
708 : resource_size_t max, resource_size_t align,
709 : resource_size_t (*alignf)(void *,
710 : const struct resource *,
711 : resource_size_t,
712 : resource_size_t),
713 : void *alignf_data)
714 : {
715 : int err;
716 : struct resource_constraint constraint;
717 :
718 0 : if (!alignf)
719 0 : alignf = simple_align_resource;
720 :
721 0 : constraint.min = min;
722 0 : constraint.max = max;
723 0 : constraint.align = align;
724 0 : constraint.alignf = alignf;
725 0 : constraint.alignf_data = alignf_data;
726 :
727 0 : if ( new->parent ) {
728 : /* resource is already allocated, try reallocating with
729 : the new constraints */
730 0 : return reallocate_resource(root, new, size, &constraint);
731 : }
732 :
733 0 : write_lock(&resource_lock);
734 0 : err = find_resource(root, new, size, &constraint);
735 0 : if (err >= 0 && __request_resource(root, new))
736 0 : err = -EBUSY;
737 0 : write_unlock(&resource_lock);
738 0 : return err;
739 : }
740 :
741 : EXPORT_SYMBOL(allocate_resource);
742 :
743 : /**
744 : * lookup_resource - find an existing resource by a resource start address
745 : * @root: root resource descriptor
746 : * @start: resource start address
747 : *
748 : * Returns a pointer to the resource if found, NULL otherwise
749 : */
750 0 : struct resource *lookup_resource(struct resource *root, resource_size_t start)
751 : {
752 : struct resource *res;
753 :
754 0 : read_lock(&resource_lock);
755 0 : for (res = root->child; res; res = res->sibling) {
756 0 : if (res->start == start)
757 : break;
758 : }
759 0 : read_unlock(&resource_lock);
760 :
761 0 : return res;
762 : }
763 :
764 : /*
765 : * Insert a resource into the resource tree. If successful, return NULL,
766 : * otherwise return the conflicting resource (compare to __request_resource())
767 : */
768 0 : static struct resource * __insert_resource(struct resource *parent, struct resource *new)
769 : {
770 : struct resource *first, *next;
771 :
772 : for (;; parent = first) {
773 0 : first = __request_resource(parent, new);
774 0 : if (!first)
775 : return first;
776 :
777 0 : if (first == parent)
778 : return first;
779 0 : if (WARN_ON(first == new)) /* duplicated insertion */
780 : return first;
781 :
782 0 : if ((first->start > new->start) || (first->end < new->end))
783 : break;
784 0 : if ((first->start == new->start) && (first->end == new->end))
785 : break;
786 : }
787 :
788 : for (next = first; ; next = next->sibling) {
789 : /* Partial overlap? Bad, and unfixable */
790 0 : if (next->start < new->start || next->end > new->end)
791 : return next;
792 0 : if (!next->sibling)
793 : break;
794 0 : if (next->sibling->start > new->end)
795 : break;
796 : }
797 :
798 0 : new->parent = parent;
799 0 : new->sibling = next->sibling;
800 0 : new->child = first;
801 :
802 0 : next->sibling = NULL;
803 0 : for (next = first; next; next = next->sibling)
804 0 : next->parent = new;
805 :
806 0 : if (parent->child == first) {
807 0 : parent->child = new;
808 : } else {
809 : next = parent->child;
810 0 : while (next->sibling != first)
811 : next = next->sibling;
812 0 : next->sibling = new;
813 : }
814 : return NULL;
815 : }
816 :
817 : /**
818 : * insert_resource_conflict - Inserts resource in the resource tree
819 : * @parent: parent of the new resource
820 : * @new: new resource to insert
821 : *
822 : * Returns 0 on success, conflict resource if the resource can't be inserted.
823 : *
824 : * This function is equivalent to request_resource_conflict when no conflict
825 : * happens. If a conflict happens, and the conflicting resources
826 : * entirely fit within the range of the new resource, then the new
827 : * resource is inserted and the conflicting resources become children of
828 : * the new resource.
829 : *
830 : * This function is intended for producers of resources, such as FW modules
831 : * and bus drivers.
832 : */
833 0 : struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
834 : {
835 : struct resource *conflict;
836 :
837 0 : write_lock(&resource_lock);
838 0 : conflict = __insert_resource(parent, new);
839 0 : write_unlock(&resource_lock);
840 0 : return conflict;
841 : }
842 :
843 : /**
844 : * insert_resource - Inserts a resource in the resource tree
845 : * @parent: parent of the new resource
846 : * @new: new resource to insert
847 : *
848 : * Returns 0 on success, -EBUSY if the resource can't be inserted.
849 : *
850 : * This function is intended for producers of resources, such as FW modules
851 : * and bus drivers.
852 : */
853 0 : int insert_resource(struct resource *parent, struct resource *new)
854 : {
855 : struct resource *conflict;
856 :
857 0 : conflict = insert_resource_conflict(parent, new);
858 0 : return conflict ? -EBUSY : 0;
859 : }
860 : EXPORT_SYMBOL_GPL(insert_resource);
861 :
862 : /**
863 : * insert_resource_expand_to_fit - Insert a resource into the resource tree
864 : * @root: root resource descriptor
865 : * @new: new resource to insert
866 : *
867 : * Insert a resource into the resource tree, possibly expanding it in order
868 : * to make it encompass any conflicting resources.
869 : */
870 0 : void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
871 : {
872 0 : if (new->parent)
873 : return;
874 :
875 0 : write_lock(&resource_lock);
876 0 : for (;;) {
877 : struct resource *conflict;
878 :
879 0 : conflict = __insert_resource(root, new);
880 0 : if (!conflict)
881 : break;
882 0 : if (conflict == root)
883 : break;
884 :
885 : /* Ok, expand resource to cover the conflict, then try again .. */
886 0 : if (conflict->start < new->start)
887 0 : new->start = conflict->start;
888 0 : if (conflict->end > new->end)
889 0 : new->end = conflict->end;
890 :
891 0 : pr_info("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
892 : }
893 0 : write_unlock(&resource_lock);
894 : }
895 : /*
896 : * Not for general consumption, only early boot memory map parsing, PCI
897 : * resource discovery, and late discovery of CXL resources are expected
898 : * to use this interface. The former are built-in and only the latter,
899 : * CXL, is a module.
900 : */
901 : EXPORT_SYMBOL_NS_GPL(insert_resource_expand_to_fit, CXL);
902 :
903 : /**
904 : * remove_resource - Remove a resource in the resource tree
905 : * @old: resource to remove
906 : *
907 : * Returns 0 on success, -EINVAL if the resource is not valid.
908 : *
909 : * This function removes a resource previously inserted by insert_resource()
910 : * or insert_resource_conflict(), and moves the children (if any) up to
911 : * where they were before. insert_resource() and insert_resource_conflict()
912 : * insert a new resource, and move any conflicting resources down to the
913 : * children of the new resource.
914 : *
915 : * insert_resource(), insert_resource_conflict() and remove_resource() are
916 : * intended for producers of resources, such as FW modules and bus drivers.
917 : */
918 0 : int remove_resource(struct resource *old)
919 : {
920 : int retval;
921 :
922 0 : write_lock(&resource_lock);
923 0 : retval = __release_resource(old, false);
924 0 : write_unlock(&resource_lock);
925 0 : return retval;
926 : }
927 : EXPORT_SYMBOL_GPL(remove_resource);
928 :
929 0 : static int __adjust_resource(struct resource *res, resource_size_t start,
930 : resource_size_t size)
931 : {
932 0 : struct resource *tmp, *parent = res->parent;
933 0 : resource_size_t end = start + size - 1;
934 0 : int result = -EBUSY;
935 :
936 0 : if (!parent)
937 : goto skip;
938 :
939 0 : if ((start < parent->start) || (end > parent->end))
940 : goto out;
941 :
942 0 : if (res->sibling && (res->sibling->start <= end))
943 : goto out;
944 :
945 0 : tmp = parent->child;
946 0 : if (tmp != res) {
947 0 : while (tmp->sibling != res)
948 : tmp = tmp->sibling;
949 0 : if (start <= tmp->end)
950 : goto out;
951 : }
952 :
953 : skip:
954 0 : for (tmp = res->child; tmp; tmp = tmp->sibling)
955 0 : if ((tmp->start < start) || (tmp->end > end))
956 : goto out;
957 :
958 0 : res->start = start;
959 0 : res->end = end;
960 0 : result = 0;
961 :
962 : out:
963 0 : return result;
964 : }
965 :
966 : /**
967 : * adjust_resource - modify a resource's start and size
968 : * @res: resource to modify
969 : * @start: new start value
970 : * @size: new size
971 : *
972 : * Given an existing resource, change its start and size to match the
973 : * arguments. Returns 0 on success, -EBUSY if it can't fit.
974 : * Existing children of the resource are assumed to be immutable.
975 : */
976 0 : int adjust_resource(struct resource *res, resource_size_t start,
977 : resource_size_t size)
978 : {
979 : int result;
980 :
981 0 : write_lock(&resource_lock);
982 0 : result = __adjust_resource(res, start, size);
983 0 : write_unlock(&resource_lock);
984 0 : return result;
985 : }
986 : EXPORT_SYMBOL(adjust_resource);
987 :
988 : static void __init
989 0 : __reserve_region_with_split(struct resource *root, resource_size_t start,
990 : resource_size_t end, const char *name)
991 : {
992 0 : struct resource *parent = root;
993 : struct resource *conflict;
994 0 : struct resource *res = alloc_resource(GFP_ATOMIC);
995 0 : struct resource *next_res = NULL;
996 0 : int type = resource_type(root);
997 :
998 0 : if (!res)
999 : return;
1000 :
1001 0 : res->name = name;
1002 0 : res->start = start;
1003 0 : res->end = end;
1004 0 : res->flags = type | IORESOURCE_BUSY;
1005 0 : res->desc = IORES_DESC_NONE;
1006 :
1007 : while (1) {
1008 :
1009 0 : conflict = __request_resource(parent, res);
1010 0 : if (!conflict) {
1011 0 : if (!next_res)
1012 : break;
1013 0 : res = next_res;
1014 0 : next_res = NULL;
1015 0 : continue;
1016 : }
1017 :
1018 : /* conflict covered whole area */
1019 0 : if (conflict->start <= res->start &&
1020 0 : conflict->end >= res->end) {
1021 0 : free_resource(res);
1022 0 : WARN_ON(next_res);
1023 : break;
1024 : }
1025 :
1026 : /* failed, split and try again */
1027 0 : if (conflict->start > res->start) {
1028 0 : end = res->end;
1029 0 : res->end = conflict->start - 1;
1030 0 : if (conflict->end < end) {
1031 0 : next_res = alloc_resource(GFP_ATOMIC);
1032 0 : if (!next_res) {
1033 0 : free_resource(res);
1034 0 : break;
1035 : }
1036 0 : next_res->name = name;
1037 0 : next_res->start = conflict->end + 1;
1038 0 : next_res->end = end;
1039 0 : next_res->flags = type | IORESOURCE_BUSY;
1040 0 : next_res->desc = IORES_DESC_NONE;
1041 : }
1042 : } else {
1043 0 : res->start = conflict->end + 1;
1044 : }
1045 : }
1046 :
1047 : }
1048 :
1049 : void __init
1050 0 : reserve_region_with_split(struct resource *root, resource_size_t start,
1051 : resource_size_t end, const char *name)
1052 : {
1053 0 : int abort = 0;
1054 :
1055 0 : write_lock(&resource_lock);
1056 0 : if (root->start > start || root->end < end) {
1057 0 : pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
1058 : (unsigned long long)start, (unsigned long long)end,
1059 : root);
1060 0 : if (start > root->end || end < root->start)
1061 : abort = 1;
1062 : else {
1063 0 : if (end > root->end)
1064 0 : end = root->end;
1065 0 : if (start < root->start)
1066 0 : start = root->start;
1067 0 : pr_err("fixing request to [0x%llx-0x%llx]\n",
1068 : (unsigned long long)start,
1069 : (unsigned long long)end);
1070 : }
1071 0 : dump_stack();
1072 : }
1073 0 : if (!abort)
1074 0 : __reserve_region_with_split(root, start, end, name);
1075 0 : write_unlock(&resource_lock);
1076 0 : }
1077 :
1078 : /**
1079 : * resource_alignment - calculate resource's alignment
1080 : * @res: resource pointer
1081 : *
1082 : * Returns alignment on success, 0 (invalid alignment) on failure.
1083 : */
1084 0 : resource_size_t resource_alignment(struct resource *res)
1085 : {
1086 0 : switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
1087 : case IORESOURCE_SIZEALIGN:
1088 0 : return resource_size(res);
1089 : case IORESOURCE_STARTALIGN:
1090 0 : return res->start;
1091 : default:
1092 : return 0;
1093 : }
1094 : }
1095 :
1096 : /*
1097 : * This is compatibility stuff for IO resources.
1098 : *
1099 : * Note how this, unlike the above, knows about
1100 : * the IO flag meanings (busy etc).
1101 : *
1102 : * request_region creates a new busy region.
1103 : *
1104 : * release_region releases a matching busy region.
1105 : */
1106 :
1107 : static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
1108 :
1109 : static struct inode *iomem_inode;
1110 :
1111 : #ifdef CONFIG_IO_STRICT_DEVMEM
1112 : static void revoke_iomem(struct resource *res)
1113 : {
1114 : /* pairs with smp_store_release() in iomem_init_inode() */
1115 : struct inode *inode = smp_load_acquire(&iomem_inode);
1116 :
1117 : /*
1118 : * Check that the initialization has completed. Losing the race
1119 : * is ok because it means drivers are claiming resources before
1120 : * the fs_initcall level of init and prevent iomem_get_mapping users
1121 : * from establishing mappings.
1122 : */
1123 : if (!inode)
1124 : return;
1125 :
1126 : /*
1127 : * The expectation is that the driver has successfully marked
1128 : * the resource busy by this point, so devmem_is_allowed()
1129 : * should start returning false, however for performance this
1130 : * does not iterate the entire resource range.
1131 : */
1132 : if (devmem_is_allowed(PHYS_PFN(res->start)) &&
1133 : devmem_is_allowed(PHYS_PFN(res->end))) {
1134 : /*
1135 : * *cringe* iomem=relaxed says "go ahead, what's the
1136 : * worst that can happen?"
1137 : */
1138 : return;
1139 : }
1140 :
1141 : unmap_mapping_range(inode->i_mapping, res->start, resource_size(res), 1);
1142 : }
1143 : #else
1144 : static void revoke_iomem(struct resource *res) {}
1145 : #endif
1146 :
1147 0 : struct address_space *iomem_get_mapping(void)
1148 : {
1149 : /*
1150 : * This function is only called from file open paths, hence guaranteed
1151 : * that fs_initcalls have completed and no need to check for NULL. But
1152 : * since revoke_iomem can be called before the initcall we still need
1153 : * the barrier to appease checkers.
1154 : */
1155 0 : return smp_load_acquire(&iomem_inode)->i_mapping;
1156 : }
1157 :
1158 0 : static int __request_region_locked(struct resource *res, struct resource *parent,
1159 : resource_size_t start, resource_size_t n,
1160 : const char *name, int flags)
1161 : {
1162 0 : DECLARE_WAITQUEUE(wait, current);
1163 :
1164 0 : res->name = name;
1165 0 : res->start = start;
1166 0 : res->end = start + n - 1;
1167 :
1168 : for (;;) {
1169 : struct resource *conflict;
1170 :
1171 0 : res->flags = resource_type(parent) | resource_ext_type(parent);
1172 0 : res->flags |= IORESOURCE_BUSY | flags;
1173 0 : res->desc = parent->desc;
1174 :
1175 0 : conflict = __request_resource(parent, res);
1176 0 : if (!conflict)
1177 : break;
1178 : /*
1179 : * mm/hmm.c reserves physical addresses which then
1180 : * become unavailable to other users. Conflicts are
1181 : * not expected. Warn to aid debugging if encountered.
1182 : */
1183 0 : if (conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) {
1184 0 : pr_warn("Unaddressable device %s %pR conflicts with %pR",
1185 : conflict->name, conflict, res);
1186 : }
1187 0 : if (conflict != parent) {
1188 0 : if (!(conflict->flags & IORESOURCE_BUSY)) {
1189 0 : parent = conflict;
1190 0 : continue;
1191 : }
1192 : }
1193 0 : if (conflict->flags & flags & IORESOURCE_MUXED) {
1194 0 : add_wait_queue(&muxed_resource_wait, &wait);
1195 0 : write_unlock(&resource_lock);
1196 0 : set_current_state(TASK_UNINTERRUPTIBLE);
1197 0 : schedule();
1198 0 : remove_wait_queue(&muxed_resource_wait, &wait);
1199 0 : write_lock(&resource_lock);
1200 0 : continue;
1201 : }
1202 : /* Uhhuh, that didn't work out.. */
1203 : return -EBUSY;
1204 : }
1205 :
1206 : return 0;
1207 : }
1208 :
1209 : /**
1210 : * __request_region - create a new busy resource region
1211 : * @parent: parent resource descriptor
1212 : * @start: resource start address
1213 : * @n: resource region size
1214 : * @name: reserving caller's ID string
1215 : * @flags: IO resource flags
1216 : */
1217 0 : struct resource *__request_region(struct resource *parent,
1218 : resource_size_t start, resource_size_t n,
1219 : const char *name, int flags)
1220 : {
1221 0 : struct resource *res = alloc_resource(GFP_KERNEL);
1222 : int ret;
1223 :
1224 0 : if (!res)
1225 : return NULL;
1226 :
1227 0 : write_lock(&resource_lock);
1228 0 : ret = __request_region_locked(res, parent, start, n, name, flags);
1229 0 : write_unlock(&resource_lock);
1230 :
1231 0 : if (ret) {
1232 0 : free_resource(res);
1233 0 : return NULL;
1234 : }
1235 :
1236 : if (parent == &iomem_resource)
1237 : revoke_iomem(res);
1238 :
1239 : return res;
1240 : }
1241 : EXPORT_SYMBOL(__request_region);
1242 :
1243 : /**
1244 : * __release_region - release a previously reserved resource region
1245 : * @parent: parent resource descriptor
1246 : * @start: resource start address
1247 : * @n: resource region size
1248 : *
1249 : * The described resource region must match a currently busy region.
1250 : */
1251 0 : void __release_region(struct resource *parent, resource_size_t start,
1252 : resource_size_t n)
1253 : {
1254 : struct resource **p;
1255 : resource_size_t end;
1256 :
1257 0 : p = &parent->child;
1258 0 : end = start + n - 1;
1259 :
1260 0 : write_lock(&resource_lock);
1261 :
1262 : for (;;) {
1263 0 : struct resource *res = *p;
1264 :
1265 0 : if (!res)
1266 : break;
1267 0 : if (res->start <= start && res->end >= end) {
1268 0 : if (!(res->flags & IORESOURCE_BUSY)) {
1269 0 : p = &res->child;
1270 0 : continue;
1271 : }
1272 0 : if (res->start != start || res->end != end)
1273 : break;
1274 0 : *p = res->sibling;
1275 0 : write_unlock(&resource_lock);
1276 0 : if (res->flags & IORESOURCE_MUXED)
1277 0 : wake_up(&muxed_resource_wait);
1278 0 : free_resource(res);
1279 0 : return;
1280 : }
1281 0 : p = &res->sibling;
1282 : }
1283 :
1284 0 : write_unlock(&resource_lock);
1285 :
1286 0 : pr_warn("Trying to free nonexistent resource <%pa-%pa>\n", &start, &end);
1287 : }
1288 : EXPORT_SYMBOL(__release_region);
1289 :
1290 : #ifdef CONFIG_MEMORY_HOTREMOVE
1291 : /**
1292 : * release_mem_region_adjustable - release a previously reserved memory region
1293 : * @start: resource start address
1294 : * @size: resource region size
1295 : *
1296 : * This interface is intended for memory hot-delete. The requested region
1297 : * is released from a currently busy memory resource. The requested region
1298 : * must either match exactly or fit into a single busy resource entry. In
1299 : * the latter case, the remaining resource is adjusted accordingly.
1300 : * Existing children of the busy memory resource must be immutable in the
1301 : * request.
1302 : *
1303 : * Note:
1304 : * - Additional release conditions, such as overlapping region, can be
1305 : * supported after they are confirmed as valid cases.
1306 : * - When a busy memory resource gets split into two entries, the code
1307 : * assumes that all children remain in the lower address entry for
1308 : * simplicity. Enhance this logic when necessary.
1309 : */
1310 : void release_mem_region_adjustable(resource_size_t start, resource_size_t size)
1311 : {
1312 : struct resource *parent = &iomem_resource;
1313 : struct resource *new_res = NULL;
1314 : bool alloc_nofail = false;
1315 : struct resource **p;
1316 : struct resource *res;
1317 : resource_size_t end;
1318 :
1319 : end = start + size - 1;
1320 : if (WARN_ON_ONCE((start < parent->start) || (end > parent->end)))
1321 : return;
1322 :
1323 : /*
1324 : * We free up quite a lot of memory on memory hotunplug (esp., memap),
1325 : * just before releasing the region. This is highly unlikely to
1326 : * fail - let's play save and make it never fail as the caller cannot
1327 : * perform any error handling (e.g., trying to re-add memory will fail
1328 : * similarly).
1329 : */
1330 : retry:
1331 : new_res = alloc_resource(GFP_KERNEL | (alloc_nofail ? __GFP_NOFAIL : 0));
1332 :
1333 : p = &parent->child;
1334 : write_lock(&resource_lock);
1335 :
1336 : while ((res = *p)) {
1337 : if (res->start >= end)
1338 : break;
1339 :
1340 : /* look for the next resource if it does not fit into */
1341 : if (res->start > start || res->end < end) {
1342 : p = &res->sibling;
1343 : continue;
1344 : }
1345 :
1346 : if (!(res->flags & IORESOURCE_MEM))
1347 : break;
1348 :
1349 : if (!(res->flags & IORESOURCE_BUSY)) {
1350 : p = &res->child;
1351 : continue;
1352 : }
1353 :
1354 : /* found the target resource; let's adjust accordingly */
1355 : if (res->start == start && res->end == end) {
1356 : /* free the whole entry */
1357 : *p = res->sibling;
1358 : free_resource(res);
1359 : } else if (res->start == start && res->end != end) {
1360 : /* adjust the start */
1361 : WARN_ON_ONCE(__adjust_resource(res, end + 1,
1362 : res->end - end));
1363 : } else if (res->start != start && res->end == end) {
1364 : /* adjust the end */
1365 : WARN_ON_ONCE(__adjust_resource(res, res->start,
1366 : start - res->start));
1367 : } else {
1368 : /* split into two entries - we need a new resource */
1369 : if (!new_res) {
1370 : new_res = alloc_resource(GFP_ATOMIC);
1371 : if (!new_res) {
1372 : alloc_nofail = true;
1373 : write_unlock(&resource_lock);
1374 : goto retry;
1375 : }
1376 : }
1377 : new_res->name = res->name;
1378 : new_res->start = end + 1;
1379 : new_res->end = res->end;
1380 : new_res->flags = res->flags;
1381 : new_res->desc = res->desc;
1382 : new_res->parent = res->parent;
1383 : new_res->sibling = res->sibling;
1384 : new_res->child = NULL;
1385 :
1386 : if (WARN_ON_ONCE(__adjust_resource(res, res->start,
1387 : start - res->start)))
1388 : break;
1389 : res->sibling = new_res;
1390 : new_res = NULL;
1391 : }
1392 :
1393 : break;
1394 : }
1395 :
1396 : write_unlock(&resource_lock);
1397 : free_resource(new_res);
1398 : }
1399 : #endif /* CONFIG_MEMORY_HOTREMOVE */
1400 :
1401 : #ifdef CONFIG_MEMORY_HOTPLUG
1402 : static bool system_ram_resources_mergeable(struct resource *r1,
1403 : struct resource *r2)
1404 : {
1405 : /* We assume either r1 or r2 is IORESOURCE_SYSRAM_MERGEABLE. */
1406 : return r1->flags == r2->flags && r1->end + 1 == r2->start &&
1407 : r1->name == r2->name && r1->desc == r2->desc &&
1408 : !r1->child && !r2->child;
1409 : }
1410 :
1411 : /**
1412 : * merge_system_ram_resource - mark the System RAM resource mergeable and try to
1413 : * merge it with adjacent, mergeable resources
1414 : * @res: resource descriptor
1415 : *
1416 : * This interface is intended for memory hotplug, whereby lots of contiguous
1417 : * system ram resources are added (e.g., via add_memory*()) by a driver, and
1418 : * the actual resource boundaries are not of interest (e.g., it might be
1419 : * relevant for DIMMs). Only resources that are marked mergeable, that have the
1420 : * same parent, and that don't have any children are considered. All mergeable
1421 : * resources must be immutable during the request.
1422 : *
1423 : * Note:
1424 : * - The caller has to make sure that no pointers to resources that are
1425 : * marked mergeable are used anymore after this call - the resource might
1426 : * be freed and the pointer might be stale!
1427 : * - release_mem_region_adjustable() will split on demand on memory hotunplug
1428 : */
1429 : void merge_system_ram_resource(struct resource *res)
1430 : {
1431 : const unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
1432 : struct resource *cur;
1433 :
1434 : if (WARN_ON_ONCE((res->flags & flags) != flags))
1435 : return;
1436 :
1437 : write_lock(&resource_lock);
1438 : res->flags |= IORESOURCE_SYSRAM_MERGEABLE;
1439 :
1440 : /* Try to merge with next item in the list. */
1441 : cur = res->sibling;
1442 : if (cur && system_ram_resources_mergeable(res, cur)) {
1443 : res->end = cur->end;
1444 : res->sibling = cur->sibling;
1445 : free_resource(cur);
1446 : }
1447 :
1448 : /* Try to merge with previous item in the list. */
1449 : cur = res->parent->child;
1450 : while (cur && cur->sibling != res)
1451 : cur = cur->sibling;
1452 : if (cur && system_ram_resources_mergeable(cur, res)) {
1453 : cur->end = res->end;
1454 : cur->sibling = res->sibling;
1455 : free_resource(res);
1456 : }
1457 : write_unlock(&resource_lock);
1458 : }
1459 : #endif /* CONFIG_MEMORY_HOTPLUG */
1460 :
1461 : /*
1462 : * Managed region resource
1463 : */
1464 0 : static void devm_resource_release(struct device *dev, void *ptr)
1465 : {
1466 0 : struct resource **r = ptr;
1467 :
1468 0 : release_resource(*r);
1469 0 : }
1470 :
1471 : /**
1472 : * devm_request_resource() - request and reserve an I/O or memory resource
1473 : * @dev: device for which to request the resource
1474 : * @root: root of the resource tree from which to request the resource
1475 : * @new: descriptor of the resource to request
1476 : *
1477 : * This is a device-managed version of request_resource(). There is usually
1478 : * no need to release resources requested by this function explicitly since
1479 : * that will be taken care of when the device is unbound from its driver.
1480 : * If for some reason the resource needs to be released explicitly, because
1481 : * of ordering issues for example, drivers must call devm_release_resource()
1482 : * rather than the regular release_resource().
1483 : *
1484 : * When a conflict is detected between any existing resources and the newly
1485 : * requested resource, an error message will be printed.
1486 : *
1487 : * Returns 0 on success or a negative error code on failure.
1488 : */
1489 0 : int devm_request_resource(struct device *dev, struct resource *root,
1490 : struct resource *new)
1491 : {
1492 : struct resource *conflict, **ptr;
1493 :
1494 0 : ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL);
1495 0 : if (!ptr)
1496 : return -ENOMEM;
1497 :
1498 0 : *ptr = new;
1499 :
1500 0 : conflict = request_resource_conflict(root, new);
1501 0 : if (conflict) {
1502 0 : dev_err(dev, "resource collision: %pR conflicts with %s %pR\n",
1503 : new, conflict->name, conflict);
1504 0 : devres_free(ptr);
1505 0 : return -EBUSY;
1506 : }
1507 :
1508 0 : devres_add(dev, ptr);
1509 0 : return 0;
1510 : }
1511 : EXPORT_SYMBOL(devm_request_resource);
1512 :
1513 0 : static int devm_resource_match(struct device *dev, void *res, void *data)
1514 : {
1515 0 : struct resource **ptr = res;
1516 :
1517 0 : return *ptr == data;
1518 : }
1519 :
1520 : /**
1521 : * devm_release_resource() - release a previously requested resource
1522 : * @dev: device for which to release the resource
1523 : * @new: descriptor of the resource to release
1524 : *
1525 : * Releases a resource previously requested using devm_request_resource().
1526 : */
1527 0 : void devm_release_resource(struct device *dev, struct resource *new)
1528 : {
1529 0 : WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match,
1530 : new));
1531 0 : }
1532 : EXPORT_SYMBOL(devm_release_resource);
1533 :
1534 : struct region_devres {
1535 : struct resource *parent;
1536 : resource_size_t start;
1537 : resource_size_t n;
1538 : };
1539 :
1540 0 : static void devm_region_release(struct device *dev, void *res)
1541 : {
1542 0 : struct region_devres *this = res;
1543 :
1544 0 : __release_region(this->parent, this->start, this->n);
1545 0 : }
1546 :
1547 0 : static int devm_region_match(struct device *dev, void *res, void *match_data)
1548 : {
1549 0 : struct region_devres *this = res, *match = match_data;
1550 :
1551 0 : return this->parent == match->parent &&
1552 0 : this->start == match->start && this->n == match->n;
1553 : }
1554 :
1555 : struct resource *
1556 0 : __devm_request_region(struct device *dev, struct resource *parent,
1557 : resource_size_t start, resource_size_t n, const char *name)
1558 : {
1559 0 : struct region_devres *dr = NULL;
1560 : struct resource *res;
1561 :
1562 0 : dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
1563 : GFP_KERNEL);
1564 0 : if (!dr)
1565 : return NULL;
1566 :
1567 0 : dr->parent = parent;
1568 0 : dr->start = start;
1569 0 : dr->n = n;
1570 :
1571 0 : res = __request_region(parent, start, n, name, 0);
1572 0 : if (res)
1573 0 : devres_add(dev, dr);
1574 : else
1575 0 : devres_free(dr);
1576 :
1577 : return res;
1578 : }
1579 : EXPORT_SYMBOL(__devm_request_region);
1580 :
1581 0 : void __devm_release_region(struct device *dev, struct resource *parent,
1582 : resource_size_t start, resource_size_t n)
1583 : {
1584 0 : struct region_devres match_data = { parent, start, n };
1585 :
1586 0 : __release_region(parent, start, n);
1587 0 : WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
1588 : &match_data));
1589 0 : }
1590 : EXPORT_SYMBOL(__devm_release_region);
1591 :
1592 : /*
1593 : * Reserve I/O ports or memory based on "reserve=" kernel parameter.
1594 : */
1595 : #define MAXRESERVE 4
1596 0 : static int __init reserve_setup(char *str)
1597 : {
1598 : static int reserved;
1599 : static struct resource reserve[MAXRESERVE];
1600 :
1601 0 : for (;;) {
1602 : unsigned int io_start, io_num;
1603 0 : int x = reserved;
1604 : struct resource *parent;
1605 :
1606 0 : if (get_option(&str, &io_start) != 2)
1607 : break;
1608 0 : if (get_option(&str, &io_num) == 0)
1609 : break;
1610 0 : if (x < MAXRESERVE) {
1611 0 : struct resource *res = reserve + x;
1612 :
1613 : /*
1614 : * If the region starts below 0x10000, we assume it's
1615 : * I/O port space; otherwise assume it's memory.
1616 : */
1617 0 : if (io_start < 0x10000) {
1618 0 : res->flags = IORESOURCE_IO;
1619 0 : parent = &ioport_resource;
1620 : } else {
1621 0 : res->flags = IORESOURCE_MEM;
1622 0 : parent = &iomem_resource;
1623 : }
1624 0 : res->name = "reserved";
1625 0 : res->start = io_start;
1626 0 : res->end = io_start + io_num - 1;
1627 0 : res->flags |= IORESOURCE_BUSY;
1628 0 : res->desc = IORES_DESC_NONE;
1629 0 : res->child = NULL;
1630 0 : if (request_resource(parent, res) == 0)
1631 0 : reserved = x+1;
1632 : }
1633 : }
1634 0 : return 1;
1635 : }
1636 : __setup("reserve=", reserve_setup);
1637 :
1638 : /*
1639 : * Check if the requested addr and size spans more than any slot in the
1640 : * iomem resource tree.
1641 : */
1642 0 : int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
1643 : {
1644 0 : struct resource *p = &iomem_resource;
1645 0 : resource_size_t end = addr + size - 1;
1646 0 : int err = 0;
1647 : loff_t l;
1648 :
1649 0 : read_lock(&resource_lock);
1650 0 : for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1651 : /*
1652 : * We can probably skip the resources without
1653 : * IORESOURCE_IO attribute?
1654 : */
1655 0 : if (p->start > end)
1656 0 : continue;
1657 0 : if (p->end < addr)
1658 0 : continue;
1659 0 : if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
1660 0 : PFN_DOWN(p->end) >= PFN_DOWN(end))
1661 0 : continue;
1662 : /*
1663 : * if a resource is "BUSY", it's not a hardware resource
1664 : * but a driver mapping of such a resource; we don't want
1665 : * to warn for those; some drivers legitimately map only
1666 : * partial hardware resources. (example: vesafb)
1667 : */
1668 0 : if (p->flags & IORESOURCE_BUSY)
1669 0 : continue;
1670 :
1671 0 : pr_warn("resource sanity check: requesting [mem %pa-%pa], which spans more than %s %pR\n",
1672 : &addr, &end, p->name, p);
1673 0 : err = -1;
1674 0 : break;
1675 : }
1676 0 : read_unlock(&resource_lock);
1677 :
1678 0 : return err;
1679 : }
1680 :
1681 : #ifdef CONFIG_STRICT_DEVMEM
1682 : static int strict_iomem_checks = 1;
1683 : #else
1684 : static int strict_iomem_checks;
1685 : #endif
1686 :
1687 : /*
1688 : * Check if an address is exclusive to the kernel and must not be mapped to
1689 : * user space, for example, via /dev/mem.
1690 : *
1691 : * Returns true if exclusive to the kernel, otherwise returns false.
1692 : */
1693 0 : bool resource_is_exclusive(struct resource *root, u64 addr, resource_size_t size)
1694 : {
1695 0 : const unsigned int exclusive_system_ram = IORESOURCE_SYSTEM_RAM |
1696 : IORESOURCE_EXCLUSIVE;
1697 0 : bool skip_children = false, err = false;
1698 : struct resource *p;
1699 :
1700 0 : read_lock(&resource_lock);
1701 0 : for_each_resource(root, p, skip_children) {
1702 0 : if (p->start >= addr + size)
1703 : break;
1704 0 : if (p->end < addr) {
1705 0 : skip_children = true;
1706 0 : continue;
1707 : }
1708 0 : skip_children = false;
1709 :
1710 : /*
1711 : * IORESOURCE_SYSTEM_RAM resources are exclusive if
1712 : * IORESOURCE_EXCLUSIVE is set, even if they
1713 : * are not busy and even if "iomem=relaxed" is set. The
1714 : * responsible driver dynamically adds/removes system RAM within
1715 : * such an area and uncontrolled access is dangerous.
1716 : */
1717 0 : if ((p->flags & exclusive_system_ram) == exclusive_system_ram) {
1718 : err = true;
1719 : break;
1720 : }
1721 :
1722 : /*
1723 : * A resource is exclusive if IORESOURCE_EXCLUSIVE is set
1724 : * or CONFIG_IO_STRICT_DEVMEM is enabled and the
1725 : * resource is busy.
1726 : */
1727 0 : if (!strict_iomem_checks || !(p->flags & IORESOURCE_BUSY))
1728 0 : continue;
1729 0 : if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM)
1730 0 : || p->flags & IORESOURCE_EXCLUSIVE) {
1731 : err = true;
1732 : break;
1733 : }
1734 : }
1735 0 : read_unlock(&resource_lock);
1736 :
1737 0 : return err;
1738 : }
1739 :
1740 0 : bool iomem_is_exclusive(u64 addr)
1741 : {
1742 0 : return resource_is_exclusive(&iomem_resource, addr & PAGE_MASK,
1743 : PAGE_SIZE);
1744 : }
1745 :
1746 0 : struct resource_entry *resource_list_create_entry(struct resource *res,
1747 : size_t extra_size)
1748 : {
1749 : struct resource_entry *entry;
1750 :
1751 0 : entry = kzalloc(sizeof(*entry) + extra_size, GFP_KERNEL);
1752 0 : if (entry) {
1753 0 : INIT_LIST_HEAD(&entry->node);
1754 0 : entry->res = res ? res : &entry->__res;
1755 : }
1756 :
1757 0 : return entry;
1758 : }
1759 : EXPORT_SYMBOL(resource_list_create_entry);
1760 :
1761 0 : void resource_list_free(struct list_head *head)
1762 : {
1763 : struct resource_entry *entry, *tmp;
1764 :
1765 0 : list_for_each_entry_safe(entry, tmp, head, node)
1766 0 : resource_list_destroy_entry(entry);
1767 0 : }
1768 : EXPORT_SYMBOL(resource_list_free);
1769 :
1770 : #ifdef CONFIG_GET_FREE_REGION
1771 : #define GFR_DESCENDING (1UL << 0)
1772 : #define GFR_REQUEST_REGION (1UL << 1)
1773 : #define GFR_DEFAULT_ALIGN (1UL << PA_SECTION_SHIFT)
1774 :
1775 : static resource_size_t gfr_start(struct resource *base, resource_size_t size,
1776 : resource_size_t align, unsigned long flags)
1777 : {
1778 : if (flags & GFR_DESCENDING) {
1779 : resource_size_t end;
1780 :
1781 : end = min_t(resource_size_t, base->end,
1782 : (1ULL << MAX_PHYSMEM_BITS) - 1);
1783 : return end - size + 1;
1784 : }
1785 :
1786 : return ALIGN(base->start, align);
1787 : }
1788 :
1789 : static bool gfr_continue(struct resource *base, resource_size_t addr,
1790 : resource_size_t size, unsigned long flags)
1791 : {
1792 : if (flags & GFR_DESCENDING)
1793 : return addr > size && addr >= base->start;
1794 : /*
1795 : * In the ascend case be careful that the last increment by
1796 : * @size did not wrap 0.
1797 : */
1798 : return addr > addr - size &&
1799 : addr <= min_t(resource_size_t, base->end,
1800 : (1ULL << MAX_PHYSMEM_BITS) - 1);
1801 : }
1802 :
1803 : static resource_size_t gfr_next(resource_size_t addr, resource_size_t size,
1804 : unsigned long flags)
1805 : {
1806 : if (flags & GFR_DESCENDING)
1807 : return addr - size;
1808 : return addr + size;
1809 : }
1810 :
1811 : static void remove_free_mem_region(void *_res)
1812 : {
1813 : struct resource *res = _res;
1814 :
1815 : if (res->parent)
1816 : remove_resource(res);
1817 : free_resource(res);
1818 : }
1819 :
1820 : static struct resource *
1821 : get_free_mem_region(struct device *dev, struct resource *base,
1822 : resource_size_t size, const unsigned long align,
1823 : const char *name, const unsigned long desc,
1824 : const unsigned long flags)
1825 : {
1826 : resource_size_t addr;
1827 : struct resource *res;
1828 : struct region_devres *dr = NULL;
1829 :
1830 : size = ALIGN(size, align);
1831 :
1832 : res = alloc_resource(GFP_KERNEL);
1833 : if (!res)
1834 : return ERR_PTR(-ENOMEM);
1835 :
1836 : if (dev && (flags & GFR_REQUEST_REGION)) {
1837 : dr = devres_alloc(devm_region_release,
1838 : sizeof(struct region_devres), GFP_KERNEL);
1839 : if (!dr) {
1840 : free_resource(res);
1841 : return ERR_PTR(-ENOMEM);
1842 : }
1843 : } else if (dev) {
1844 : if (devm_add_action_or_reset(dev, remove_free_mem_region, res))
1845 : return ERR_PTR(-ENOMEM);
1846 : }
1847 :
1848 : write_lock(&resource_lock);
1849 : for (addr = gfr_start(base, size, align, flags);
1850 : gfr_continue(base, addr, size, flags);
1851 : addr = gfr_next(addr, size, flags)) {
1852 : if (__region_intersects(base, addr, size, 0, IORES_DESC_NONE) !=
1853 : REGION_DISJOINT)
1854 : continue;
1855 :
1856 : if (flags & GFR_REQUEST_REGION) {
1857 : if (__request_region_locked(res, &iomem_resource, addr,
1858 : size, name, 0))
1859 : break;
1860 :
1861 : if (dev) {
1862 : dr->parent = &iomem_resource;
1863 : dr->start = addr;
1864 : dr->n = size;
1865 : devres_add(dev, dr);
1866 : }
1867 :
1868 : res->desc = desc;
1869 : write_unlock(&resource_lock);
1870 :
1871 :
1872 : /*
1873 : * A driver is claiming this region so revoke any
1874 : * mappings.
1875 : */
1876 : revoke_iomem(res);
1877 : } else {
1878 : res->start = addr;
1879 : res->end = addr + size - 1;
1880 : res->name = name;
1881 : res->desc = desc;
1882 : res->flags = IORESOURCE_MEM;
1883 :
1884 : /*
1885 : * Only succeed if the resource hosts an exclusive
1886 : * range after the insert
1887 : */
1888 : if (__insert_resource(base, res) || res->child)
1889 : break;
1890 :
1891 : write_unlock(&resource_lock);
1892 : }
1893 :
1894 : return res;
1895 : }
1896 : write_unlock(&resource_lock);
1897 :
1898 : if (flags & GFR_REQUEST_REGION) {
1899 : free_resource(res);
1900 : devres_free(dr);
1901 : } else if (dev)
1902 : devm_release_action(dev, remove_free_mem_region, res);
1903 :
1904 : return ERR_PTR(-ERANGE);
1905 : }
1906 :
1907 : /**
1908 : * devm_request_free_mem_region - find free region for device private memory
1909 : *
1910 : * @dev: device struct to bind the resource to
1911 : * @size: size in bytes of the device memory to add
1912 : * @base: resource tree to look in
1913 : *
1914 : * This function tries to find an empty range of physical address big enough to
1915 : * contain the new resource, so that it can later be hotplugged as ZONE_DEVICE
1916 : * memory, which in turn allocates struct pages.
1917 : */
1918 : struct resource *devm_request_free_mem_region(struct device *dev,
1919 : struct resource *base, unsigned long size)
1920 : {
1921 : unsigned long flags = GFR_DESCENDING | GFR_REQUEST_REGION;
1922 :
1923 : return get_free_mem_region(dev, base, size, GFR_DEFAULT_ALIGN,
1924 : dev_name(dev),
1925 : IORES_DESC_DEVICE_PRIVATE_MEMORY, flags);
1926 : }
1927 : EXPORT_SYMBOL_GPL(devm_request_free_mem_region);
1928 :
1929 : struct resource *request_free_mem_region(struct resource *base,
1930 : unsigned long size, const char *name)
1931 : {
1932 : unsigned long flags = GFR_DESCENDING | GFR_REQUEST_REGION;
1933 :
1934 : return get_free_mem_region(NULL, base, size, GFR_DEFAULT_ALIGN, name,
1935 : IORES_DESC_DEVICE_PRIVATE_MEMORY, flags);
1936 : }
1937 : EXPORT_SYMBOL_GPL(request_free_mem_region);
1938 :
1939 : /**
1940 : * alloc_free_mem_region - find a free region relative to @base
1941 : * @base: resource that will parent the new resource
1942 : * @size: size in bytes of memory to allocate from @base
1943 : * @align: alignment requirements for the allocation
1944 : * @name: resource name
1945 : *
1946 : * Buses like CXL, that can dynamically instantiate new memory regions,
1947 : * need a method to allocate physical address space for those regions.
1948 : * Allocate and insert a new resource to cover a free, unclaimed by a
1949 : * descendant of @base, range in the span of @base.
1950 : */
1951 : struct resource *alloc_free_mem_region(struct resource *base,
1952 : unsigned long size, unsigned long align,
1953 : const char *name)
1954 : {
1955 : /* Default of ascending direction and insert resource */
1956 : unsigned long flags = 0;
1957 :
1958 : return get_free_mem_region(NULL, base, size, align, name,
1959 : IORES_DESC_NONE, flags);
1960 : }
1961 : EXPORT_SYMBOL_NS_GPL(alloc_free_mem_region, CXL);
1962 : #endif /* CONFIG_GET_FREE_REGION */
1963 :
1964 0 : static int __init strict_iomem(char *str)
1965 : {
1966 0 : if (strstr(str, "relaxed"))
1967 0 : strict_iomem_checks = 0;
1968 0 : if (strstr(str, "strict"))
1969 0 : strict_iomem_checks = 1;
1970 0 : return 1;
1971 : }
1972 :
1973 1 : static int iomem_fs_init_fs_context(struct fs_context *fc)
1974 : {
1975 1 : return init_pseudo(fc, DEVMEM_MAGIC) ? 0 : -ENOMEM;
1976 : }
1977 :
1978 : static struct file_system_type iomem_fs_type = {
1979 : .name = "iomem",
1980 : .owner = THIS_MODULE,
1981 : .init_fs_context = iomem_fs_init_fs_context,
1982 : .kill_sb = kill_anon_super,
1983 : };
1984 :
1985 1 : static int __init iomem_init_inode(void)
1986 : {
1987 : static struct vfsmount *iomem_vfs_mount;
1988 : static int iomem_fs_cnt;
1989 : struct inode *inode;
1990 : int rc;
1991 :
1992 1 : rc = simple_pin_fs(&iomem_fs_type, &iomem_vfs_mount, &iomem_fs_cnt);
1993 1 : if (rc < 0) {
1994 0 : pr_err("Cannot mount iomem pseudo filesystem: %d\n", rc);
1995 0 : return rc;
1996 : }
1997 :
1998 1 : inode = alloc_anon_inode(iomem_vfs_mount->mnt_sb);
1999 1 : if (IS_ERR(inode)) {
2000 0 : rc = PTR_ERR(inode);
2001 0 : pr_err("Cannot allocate inode for iomem: %d\n", rc);
2002 0 : simple_release_fs(&iomem_vfs_mount, &iomem_fs_cnt);
2003 0 : return rc;
2004 : }
2005 :
2006 : /*
2007 : * Publish iomem revocation inode initialized.
2008 : * Pairs with smp_load_acquire() in revoke_iomem().
2009 : */
2010 1 : smp_store_release(&iomem_inode, inode);
2011 :
2012 1 : return 0;
2013 : }
2014 :
2015 : fs_initcall(iomem_init_inode);
2016 :
2017 : __setup("iomem=", strict_iomem);
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