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 : /*
60 : * For memory hotplug, there is no way to free resource entries allocated
61 : * by boot mem after the system is up. So for reusing the resource entry
62 : * we need to remember the resource.
63 : */
64 : static struct resource *bootmem_resource_free;
65 : static DEFINE_SPINLOCK(bootmem_resource_lock);
66 :
67 44 : static struct resource *next_resource(struct resource *p, bool sibling_only)
68 : {
69 : /* Caller wants to traverse through siblings only */
70 15 : if (sibling_only)
71 15 : return p->sibling;
72 :
73 0 : if (p->child)
74 : return p->child;
75 31 : while (!p->sibling && p->parent)
76 : p = p->parent;
77 : return p->sibling;
78 : }
79 :
80 29 : static void *r_next(struct seq_file *m, void *v, loff_t *pos)
81 : {
82 29 : struct resource *p = v;
83 29 : (*pos)++;
84 0 : return (void *)next_resource(p, false);
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 0 : ;
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 0 : unsigned long long start, end;
113 0 : int width = root->end < 0x10000 ? 4 : 8;
114 0 : 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 4 : static void free_resource(struct resource *res)
154 : {
155 4 : if (!res)
156 : return;
157 :
158 8 : if (!PageSlab(virt_to_head_page(res))) {
159 0 : spin_lock(&bootmem_resource_lock);
160 0 : res->sibling = bootmem_resource_free;
161 0 : bootmem_resource_free = res;
162 0 : spin_unlock(&bootmem_resource_lock);
163 : } else {
164 4 : kfree(res);
165 : }
166 : }
167 :
168 7 : static struct resource *alloc_resource(gfp_t flags)
169 : {
170 7 : struct resource *res = NULL;
171 :
172 7 : spin_lock(&bootmem_resource_lock);
173 7 : if (bootmem_resource_free) {
174 0 : res = bootmem_resource_free;
175 0 : bootmem_resource_free = res->sibling;
176 : }
177 7 : spin_unlock(&bootmem_resource_lock);
178 :
179 7 : if (res)
180 0 : memset(res, 0, sizeof(struct resource));
181 : else
182 7 : res = kzalloc(sizeof(struct resource), flags);
183 :
184 7 : return res;
185 : }
186 :
187 : /* Return the conflict entry if you can't request it */
188 35 : static struct resource * __request_resource(struct resource *root, struct resource *new)
189 : {
190 35 : resource_size_t start = new->start;
191 35 : resource_size_t end = new->end;
192 35 : struct resource *tmp, **p;
193 :
194 35 : if (end < start)
195 : return root;
196 35 : if (start < root->start)
197 : return root;
198 35 : if (end > root->end)
199 : return root;
200 35 : p = &root->child;
201 353 : for (;;) {
202 194 : tmp = *p;
203 194 : if (!tmp || tmp->start > end) {
204 30 : new->sibling = tmp;
205 30 : *p = new;
206 30 : new->parent = root;
207 30 : return NULL;
208 : }
209 164 : p = &tmp->sibling;
210 164 : if (tmp->end < start)
211 159 : continue;
212 : return tmp;
213 : }
214 : }
215 :
216 0 : static int __release_resource(struct resource *old, bool release_child)
217 : {
218 0 : struct resource *tmp, **p, *chd;
219 :
220 0 : p = &old->parent->child;
221 0 : for (;;) {
222 0 : tmp = *p;
223 0 : if (!tmp)
224 : break;
225 0 : if (tmp == old) {
226 0 : if (release_child || !(tmp->child)) {
227 0 : *p = tmp->sibling;
228 : } else {
229 : for (chd = tmp->child;; chd = chd->sibling) {
230 0 : chd->parent = tmp->parent;
231 0 : if (!(chd->sibling))
232 : break;
233 : }
234 0 : *p = tmp->child;
235 0 : chd->sibling = tmp->sibling;
236 : }
237 0 : old->parent = NULL;
238 0 : return 0;
239 : }
240 0 : p = &tmp->sibling;
241 : }
242 : return -EINVAL;
243 : }
244 :
245 0 : static void __release_child_resources(struct resource *r)
246 : {
247 0 : struct resource *tmp, *p;
248 0 : resource_size_t size;
249 :
250 0 : p = r->child;
251 0 : r->child = NULL;
252 0 : while (p) {
253 0 : tmp = p;
254 0 : p = p->sibling;
255 :
256 0 : tmp->parent = NULL;
257 0 : tmp->sibling = NULL;
258 0 : __release_child_resources(tmp);
259 :
260 0 : printk(KERN_DEBUG "release child resource %pR\n", tmp);
261 : /* need to restore size, and keep flags */
262 0 : size = resource_size(tmp);
263 0 : tmp->start = 0;
264 0 : tmp->end = size - 1;
265 : }
266 0 : }
267 :
268 0 : void release_child_resources(struct resource *r)
269 : {
270 0 : write_lock(&resource_lock);
271 0 : __release_child_resources(r);
272 0 : write_unlock(&resource_lock);
273 0 : }
274 :
275 : /**
276 : * request_resource_conflict - 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, conflict resource on error.
281 : */
282 11 : struct resource *request_resource_conflict(struct resource *root, struct resource *new)
283 : {
284 11 : struct resource *conflict;
285 :
286 11 : write_lock(&resource_lock);
287 11 : conflict = __request_resource(root, new);
288 11 : write_unlock(&resource_lock);
289 11 : return conflict;
290 : }
291 :
292 : /**
293 : * request_resource - request and reserve an I/O or memory resource
294 : * @root: root resource descriptor
295 : * @new: resource descriptor desired by caller
296 : *
297 : * Returns 0 for success, negative error code on error.
298 : */
299 11 : int request_resource(struct resource *root, struct resource *new)
300 : {
301 11 : struct resource *conflict;
302 :
303 11 : conflict = request_resource_conflict(root, new);
304 11 : return conflict ? -EBUSY : 0;
305 : }
306 :
307 : EXPORT_SYMBOL(request_resource);
308 :
309 : /**
310 : * release_resource - release a previously reserved resource
311 : * @old: resource pointer
312 : */
313 0 : int release_resource(struct resource *old)
314 : {
315 0 : int retval;
316 :
317 0 : write_lock(&resource_lock);
318 0 : retval = __release_resource(old, true);
319 0 : write_unlock(&resource_lock);
320 0 : return retval;
321 : }
322 :
323 : EXPORT_SYMBOL(release_resource);
324 :
325 : /**
326 : * find_next_iomem_res - Finds the lowest iomem resource that covers part of
327 : * [@start..@end].
328 : *
329 : * If a resource is found, returns 0 and @*res is overwritten with the part
330 : * of the resource that's within [@start..@end]; if none is found, returns
331 : * -ENODEV. Returns -EINVAL for invalid parameters.
332 : *
333 : * This function walks the whole tree and not just first level children
334 : * unless @first_lvl is true.
335 : *
336 : * @start: start address of the resource searched for
337 : * @end: end address of same resource
338 : * @flags: flags which the resource must have
339 : * @desc: descriptor the resource must have
340 : * @first_lvl: walk only the first level children, if set
341 : * @res: return ptr, if resource found
342 : *
343 : * The caller must specify @start, @end, @flags, and @desc
344 : * (which may be IORES_DESC_NONE).
345 : */
346 2 : static int find_next_iomem_res(resource_size_t start, resource_size_t end,
347 : unsigned long flags, unsigned long desc,
348 : bool first_lvl, struct resource *res)
349 : {
350 2 : bool siblings_only = true;
351 2 : struct resource *p;
352 :
353 2 : if (!res)
354 : return -EINVAL;
355 :
356 2 : if (start >= end)
357 : return -EINVAL;
358 :
359 2 : read_lock(&resource_lock);
360 :
361 17 : for (p = iomem_resource.child; p; p = next_resource(p, siblings_only)) {
362 : /* If we passed the resource we are looking for, stop */
363 16 : if (p->start > end) {
364 : p = NULL;
365 : break;
366 : }
367 :
368 : /* Skip until we find a range that matches what we look for */
369 15 : if (p->end < start)
370 13 : continue;
371 :
372 : /*
373 : * Now that we found a range that matches what we look for,
374 : * check the flags and the descriptor. If we were not asked to
375 : * use only the first level, start looking at children as well.
376 : */
377 2 : siblings_only = first_lvl;
378 :
379 2 : if ((p->flags & flags) != flags)
380 2 : continue;
381 0 : if ((desc != IORES_DESC_NONE) && (desc != p->desc))
382 0 : continue;
383 :
384 : /* Found a match, break */
385 : break;
386 : }
387 :
388 2 : if (p) {
389 : /* copy data */
390 0 : *res = (struct resource) {
391 0 : .start = max(start, p->start),
392 0 : .end = min(end, p->end),
393 0 : .flags = p->flags,
394 0 : .desc = p->desc,
395 0 : .parent = p->parent,
396 : };
397 : }
398 :
399 2 : read_unlock(&resource_lock);
400 2 : return p ? 0 : -ENODEV;
401 : }
402 :
403 2 : static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
404 : unsigned long flags, unsigned long desc,
405 : bool first_lvl, void *arg,
406 : int (*func)(struct resource *, void *))
407 : {
408 2 : struct resource res;
409 2 : int ret = -EINVAL;
410 :
411 4 : while (start < end &&
412 2 : !find_next_iomem_res(start, end, flags, desc, first_lvl, &res)) {
413 0 : ret = (*func)(&res, arg);
414 0 : if (ret)
415 : break;
416 :
417 0 : start = res.end + 1;
418 : }
419 :
420 2 : return ret;
421 : }
422 :
423 : /**
424 : * walk_iomem_res_desc - Walks through iomem resources and calls func()
425 : * with matching resource ranges.
426 : * *
427 : * @desc: I/O resource descriptor. Use IORES_DESC_NONE to skip @desc check.
428 : * @flags: I/O resource flags
429 : * @start: start addr
430 : * @end: end addr
431 : * @arg: function argument for the callback @func
432 : * @func: callback function that is called for each qualifying resource area
433 : *
434 : * This walks through whole tree and not just first level children.
435 : * All the memory ranges which overlap start,end and also match flags and
436 : * desc are valid candidates.
437 : *
438 : * NOTE: For a new descriptor search, define a new IORES_DESC in
439 : * <linux/ioport.h> and set it in 'desc' of a target resource entry.
440 : */
441 0 : int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start,
442 : u64 end, void *arg, int (*func)(struct resource *, void *))
443 : {
444 0 : return __walk_iomem_res_desc(start, end, flags, desc, false, arg, func);
445 : }
446 : EXPORT_SYMBOL_GPL(walk_iomem_res_desc);
447 :
448 : /*
449 : * This function calls the @func callback against all memory ranges of type
450 : * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
451 : * Now, this function is only for System RAM, it deals with full ranges and
452 : * not PFNs. If resources are not PFN-aligned, dealing with PFNs can truncate
453 : * ranges.
454 : */
455 0 : int walk_system_ram_res(u64 start, u64 end, void *arg,
456 : int (*func)(struct resource *, void *))
457 : {
458 0 : unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
459 :
460 0 : return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, true,
461 : arg, func);
462 : }
463 :
464 : /*
465 : * This function calls the @func callback against all memory ranges, which
466 : * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY.
467 : */
468 2 : int walk_mem_res(u64 start, u64 end, void *arg,
469 : int (*func)(struct resource *, void *))
470 : {
471 2 : unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY;
472 :
473 2 : return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, true,
474 : arg, func);
475 : }
476 :
477 : /*
478 : * This function calls the @func callback against all memory ranges of type
479 : * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
480 : * It is to be used only for System RAM.
481 : *
482 : * This will find System RAM ranges that are children of top-level resources
483 : * in addition to top-level System RAM resources.
484 : */
485 0 : int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
486 : void *arg, int (*func)(unsigned long, unsigned long, void *))
487 : {
488 0 : resource_size_t start, end;
489 0 : unsigned long flags;
490 0 : struct resource res;
491 0 : unsigned long pfn, end_pfn;
492 0 : int ret = -EINVAL;
493 :
494 0 : start = (u64) start_pfn << PAGE_SHIFT;
495 0 : end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
496 0 : flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
497 0 : while (start < end &&
498 0 : !find_next_iomem_res(start, end, flags, IORES_DESC_NONE,
499 : false, &res)) {
500 0 : pfn = PFN_UP(res.start);
501 0 : end_pfn = PFN_DOWN(res.end + 1);
502 0 : if (end_pfn > pfn)
503 0 : ret = (*func)(pfn, end_pfn - pfn, arg);
504 0 : if (ret)
505 : break;
506 0 : start = res.end + 1;
507 : }
508 0 : return ret;
509 : }
510 :
511 0 : static int __is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
512 : {
513 0 : return 1;
514 : }
515 :
516 : /*
517 : * This generic page_is_ram() returns true if specified address is
518 : * registered as System RAM in iomem_resource list.
519 : */
520 0 : int __weak page_is_ram(unsigned long pfn)
521 : {
522 0 : return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
523 : }
524 : EXPORT_SYMBOL_GPL(page_is_ram);
525 :
526 : /**
527 : * region_intersects() - determine intersection of region with known resources
528 : * @start: region start address
529 : * @size: size of region
530 : * @flags: flags of resource (in iomem_resource)
531 : * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE
532 : *
533 : * Check if the specified region partially overlaps or fully eclipses a
534 : * resource identified by @flags and @desc (optional with IORES_DESC_NONE).
535 : * Return REGION_DISJOINT if the region does not overlap @flags/@desc,
536 : * return REGION_MIXED if the region overlaps @flags/@desc and another
537 : * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc
538 : * and no other defined resource. Note that REGION_INTERSECTS is also
539 : * returned in the case when the specified region overlaps RAM and undefined
540 : * memory holes.
541 : *
542 : * region_intersect() is used by memory remapping functions to ensure
543 : * the user is not remapping RAM and is a vast speed up over walking
544 : * through the resource table page by page.
545 : */
546 0 : int region_intersects(resource_size_t start, size_t size, unsigned long flags,
547 : unsigned long desc)
548 : {
549 0 : struct resource res;
550 0 : int type = 0; int other = 0;
551 0 : struct resource *p;
552 :
553 0 : res.start = start;
554 0 : res.end = start + size - 1;
555 :
556 0 : read_lock(&resource_lock);
557 0 : for (p = iomem_resource.child; p ; p = p->sibling) {
558 0 : bool is_type = (((p->flags & flags) == flags) &&
559 0 : ((desc == IORES_DESC_NONE) ||
560 0 : (desc == p->desc)));
561 :
562 0 : if (resource_overlaps(p, &res))
563 0 : is_type ? type++ : other++;
564 : }
565 0 : read_unlock(&resource_lock);
566 :
567 0 : if (type == 0)
568 : return REGION_DISJOINT;
569 :
570 0 : if (other == 0)
571 0 : return REGION_INTERSECTS;
572 :
573 : return REGION_MIXED;
574 : }
575 : EXPORT_SYMBOL_GPL(region_intersects);
576 :
577 0 : void __weak arch_remove_reservations(struct resource *avail)
578 : {
579 0 : }
580 :
581 0 : static resource_size_t simple_align_resource(void *data,
582 : const struct resource *avail,
583 : resource_size_t size,
584 : resource_size_t align)
585 : {
586 0 : return avail->start;
587 : }
588 :
589 0 : static void resource_clip(struct resource *res, resource_size_t min,
590 : resource_size_t max)
591 : {
592 0 : if (res->start < min)
593 0 : res->start = min;
594 0 : if (res->end > max)
595 0 : res->end = max;
596 : }
597 :
598 : /*
599 : * Find empty slot in the resource tree with the given range and
600 : * alignment constraints
601 : */
602 0 : static int __find_resource(struct resource *root, struct resource *old,
603 : struct resource *new,
604 : resource_size_t size,
605 : struct resource_constraint *constraint)
606 : {
607 0 : struct resource *this = root->child;
608 0 : struct resource tmp = *new, avail, alloc;
609 :
610 0 : tmp.start = root->start;
611 : /*
612 : * Skip past an allocated resource that starts at 0, since the assignment
613 : * of this->start - 1 to tmp->end below would cause an underflow.
614 : */
615 0 : if (this && this->start == root->start) {
616 0 : tmp.start = (this == old) ? old->start : this->end + 1;
617 0 : this = this->sibling;
618 : }
619 0 : for(;;) {
620 0 : if (this)
621 0 : tmp.end = (this == old) ? this->end : this->start - 1;
622 : else
623 0 : tmp.end = root->end;
624 :
625 0 : if (tmp.end < tmp.start)
626 0 : goto next;
627 :
628 0 : resource_clip(&tmp, constraint->min, constraint->max);
629 0 : arch_remove_reservations(&tmp);
630 :
631 : /* Check for overflow after ALIGN() */
632 0 : avail.start = ALIGN(tmp.start, constraint->align);
633 0 : avail.end = tmp.end;
634 0 : avail.flags = new->flags & ~IORESOURCE_UNSET;
635 0 : if (avail.start >= tmp.start) {
636 0 : alloc.flags = avail.flags;
637 0 : alloc.start = constraint->alignf(constraint->alignf_data, &avail,
638 : size, constraint->align);
639 0 : alloc.end = alloc.start + size - 1;
640 0 : if (alloc.start <= alloc.end &&
641 0 : resource_contains(&avail, &alloc)) {
642 0 : new->start = alloc.start;
643 0 : new->end = alloc.end;
644 0 : return 0;
645 : }
646 : }
647 :
648 0 : next: if (!this || this->end == root->end)
649 : break;
650 :
651 0 : if (this != old)
652 0 : tmp.start = this->end + 1;
653 0 : this = this->sibling;
654 : }
655 : return -EBUSY;
656 : }
657 :
658 : /*
659 : * Find empty slot in the resource tree given range and alignment.
660 : */
661 0 : static int find_resource(struct resource *root, struct resource *new,
662 : resource_size_t size,
663 : struct resource_constraint *constraint)
664 : {
665 0 : return __find_resource(root, NULL, new, size, constraint);
666 : }
667 :
668 : /**
669 : * reallocate_resource - allocate a slot in the resource tree given range & alignment.
670 : * The resource will be relocated if the new size cannot be reallocated in the
671 : * current location.
672 : *
673 : * @root: root resource descriptor
674 : * @old: resource descriptor desired by caller
675 : * @newsize: new size of the resource descriptor
676 : * @constraint: the size and alignment constraints to be met.
677 : */
678 0 : static int reallocate_resource(struct resource *root, struct resource *old,
679 : resource_size_t newsize,
680 : struct resource_constraint *constraint)
681 : {
682 0 : int err=0;
683 0 : struct resource new = *old;
684 0 : struct resource *conflict;
685 :
686 0 : write_lock(&resource_lock);
687 :
688 0 : if ((err = __find_resource(root, old, &new, newsize, constraint)))
689 0 : goto out;
690 :
691 0 : if (resource_contains(&new, old)) {
692 0 : old->start = new.start;
693 0 : old->end = new.end;
694 0 : goto out;
695 : }
696 :
697 0 : if (old->child) {
698 0 : err = -EBUSY;
699 0 : goto out;
700 : }
701 :
702 0 : if (resource_contains(old, &new)) {
703 0 : old->start = new.start;
704 0 : old->end = new.end;
705 : } else {
706 0 : __release_resource(old, true);
707 0 : *old = new;
708 0 : conflict = __request_resource(root, old);
709 0 : BUG_ON(conflict);
710 : }
711 0 : out:
712 0 : write_unlock(&resource_lock);
713 0 : return err;
714 : }
715 :
716 :
717 : /**
718 : * allocate_resource - allocate empty slot in the resource tree given range & alignment.
719 : * The resource will be reallocated with a new size if it was already allocated
720 : * @root: root resource descriptor
721 : * @new: resource descriptor desired by caller
722 : * @size: requested resource region size
723 : * @min: minimum boundary to allocate
724 : * @max: maximum boundary to allocate
725 : * @align: alignment requested, in bytes
726 : * @alignf: alignment function, optional, called if not NULL
727 : * @alignf_data: arbitrary data to pass to the @alignf function
728 : */
729 0 : int allocate_resource(struct resource *root, struct resource *new,
730 : resource_size_t size, resource_size_t min,
731 : resource_size_t max, resource_size_t align,
732 : resource_size_t (*alignf)(void *,
733 : const struct resource *,
734 : resource_size_t,
735 : resource_size_t),
736 : void *alignf_data)
737 : {
738 0 : int err;
739 0 : struct resource_constraint constraint;
740 :
741 0 : if (!alignf)
742 0 : alignf = simple_align_resource;
743 :
744 0 : constraint.min = min;
745 0 : constraint.max = max;
746 0 : constraint.align = align;
747 0 : constraint.alignf = alignf;
748 0 : constraint.alignf_data = alignf_data;
749 :
750 0 : if ( new->parent ) {
751 : /* resource is already allocated, try reallocating with
752 : the new constraints */
753 0 : return reallocate_resource(root, new, size, &constraint);
754 : }
755 :
756 0 : write_lock(&resource_lock);
757 0 : err = find_resource(root, new, size, &constraint);
758 0 : if (err >= 0 && __request_resource(root, new))
759 0 : err = -EBUSY;
760 0 : write_unlock(&resource_lock);
761 0 : return err;
762 : }
763 :
764 : EXPORT_SYMBOL(allocate_resource);
765 :
766 : /**
767 : * lookup_resource - find an existing resource by a resource start address
768 : * @root: root resource descriptor
769 : * @start: resource start address
770 : *
771 : * Returns a pointer to the resource if found, NULL otherwise
772 : */
773 0 : struct resource *lookup_resource(struct resource *root, resource_size_t start)
774 : {
775 0 : struct resource *res;
776 :
777 0 : read_lock(&resource_lock);
778 0 : for (res = root->child; res; res = res->sibling) {
779 0 : if (res->start == start)
780 : break;
781 : }
782 0 : read_unlock(&resource_lock);
783 :
784 0 : return res;
785 : }
786 :
787 : /*
788 : * Insert a resource into the resource tree. If successful, return NULL,
789 : * otherwise return the conflicting resource (compare to __request_resource())
790 : */
791 14 : static struct resource * __insert_resource(struct resource *parent, struct resource *new)
792 : {
793 14 : struct resource *first, *next;
794 :
795 14 : for (;; parent = first) {
796 14 : first = __request_resource(parent, new);
797 14 : if (!first)
798 : return first;
799 :
800 2 : if (first == parent)
801 0 : return first;
802 2 : if (WARN_ON(first == new)) /* duplicated insertion */
803 0 : return first;
804 :
805 2 : if ((first->start > new->start) || (first->end < new->end))
806 : break;
807 1 : if ((first->start == new->start) && (first->end == new->end))
808 : break;
809 : }
810 :
811 : for (next = first; ; next = next->sibling) {
812 : /* Partial overlap? Bad, and unfixable */
813 5 : if (next->start < new->start || next->end > new->end)
814 0 : return next;
815 5 : if (!next->sibling)
816 : break;
817 4 : if (next->sibling->start > new->end)
818 : break;
819 : }
820 :
821 2 : new->parent = parent;
822 2 : new->sibling = next->sibling;
823 2 : new->child = first;
824 :
825 2 : next->sibling = NULL;
826 7 : for (next = first; next; next = next->sibling)
827 5 : next->parent = new;
828 :
829 2 : if (parent->child == first) {
830 0 : parent->child = new;
831 : } else {
832 : next = parent->child;
833 9 : while (next->sibling != first)
834 : next = next->sibling;
835 2 : next->sibling = new;
836 : }
837 : return NULL;
838 : }
839 :
840 : /**
841 : * insert_resource_conflict - Inserts resource in the resource tree
842 : * @parent: parent of the new resource
843 : * @new: new resource to insert
844 : *
845 : * Returns 0 on success, conflict resource if the resource can't be inserted.
846 : *
847 : * This function is equivalent to request_resource_conflict when no conflict
848 : * happens. If a conflict happens, and the conflicting resources
849 : * entirely fit within the range of the new resource, then the new
850 : * resource is inserted and the conflicting resources become children of
851 : * the new resource.
852 : *
853 : * This function is intended for producers of resources, such as FW modules
854 : * and bus drivers.
855 : */
856 14 : struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
857 : {
858 14 : struct resource *conflict;
859 :
860 14 : write_lock(&resource_lock);
861 14 : conflict = __insert_resource(parent, new);
862 14 : write_unlock(&resource_lock);
863 14 : return conflict;
864 : }
865 :
866 : /**
867 : * insert_resource - Inserts a resource in the resource tree
868 : * @parent: parent of the new resource
869 : * @new: new resource to insert
870 : *
871 : * Returns 0 on success, -EBUSY if the resource can't be inserted.
872 : *
873 : * This function is intended for producers of resources, such as FW modules
874 : * and bus drivers.
875 : */
876 14 : int insert_resource(struct resource *parent, struct resource *new)
877 : {
878 14 : struct resource *conflict;
879 :
880 14 : conflict = insert_resource_conflict(parent, new);
881 14 : return conflict ? -EBUSY : 0;
882 : }
883 : EXPORT_SYMBOL_GPL(insert_resource);
884 :
885 : /**
886 : * insert_resource_expand_to_fit - Insert a resource into the resource tree
887 : * @root: root resource descriptor
888 : * @new: new resource to insert
889 : *
890 : * Insert a resource into the resource tree, possibly expanding it in order
891 : * to make it encompass any conflicting resources.
892 : */
893 0 : void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
894 : {
895 0 : if (new->parent)
896 : return;
897 :
898 0 : write_lock(&resource_lock);
899 0 : for (;;) {
900 0 : struct resource *conflict;
901 :
902 0 : conflict = __insert_resource(root, new);
903 0 : if (!conflict)
904 : break;
905 0 : if (conflict == root)
906 : break;
907 :
908 : /* Ok, expand resource to cover the conflict, then try again .. */
909 0 : if (conflict->start < new->start)
910 0 : new->start = conflict->start;
911 0 : if (conflict->end > new->end)
912 0 : new->end = conflict->end;
913 :
914 0 : printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name);
915 : }
916 0 : write_unlock(&resource_lock);
917 : }
918 :
919 : /**
920 : * remove_resource - Remove a resource in the resource tree
921 : * @old: resource to remove
922 : *
923 : * Returns 0 on success, -EINVAL if the resource is not valid.
924 : *
925 : * This function removes a resource previously inserted by insert_resource()
926 : * or insert_resource_conflict(), and moves the children (if any) up to
927 : * where they were before. insert_resource() and insert_resource_conflict()
928 : * insert a new resource, and move any conflicting resources down to the
929 : * children of the new resource.
930 : *
931 : * insert_resource(), insert_resource_conflict() and remove_resource() are
932 : * intended for producers of resources, such as FW modules and bus drivers.
933 : */
934 0 : int remove_resource(struct resource *old)
935 : {
936 0 : int retval;
937 :
938 0 : write_lock(&resource_lock);
939 0 : retval = __release_resource(old, false);
940 0 : write_unlock(&resource_lock);
941 0 : return retval;
942 : }
943 : EXPORT_SYMBOL_GPL(remove_resource);
944 :
945 0 : static int __adjust_resource(struct resource *res, resource_size_t start,
946 : resource_size_t size)
947 : {
948 0 : struct resource *tmp, *parent = res->parent;
949 0 : resource_size_t end = start + size - 1;
950 0 : int result = -EBUSY;
951 :
952 0 : if (!parent)
953 0 : goto skip;
954 :
955 0 : if ((start < parent->start) || (end > parent->end))
956 0 : goto out;
957 :
958 0 : if (res->sibling && (res->sibling->start <= end))
959 0 : goto out;
960 :
961 0 : tmp = parent->child;
962 0 : if (tmp != res) {
963 0 : while (tmp->sibling != res)
964 : tmp = tmp->sibling;
965 0 : if (start <= tmp->end)
966 0 : goto out;
967 : }
968 :
969 0 : skip:
970 0 : for (tmp = res->child; tmp; tmp = tmp->sibling)
971 0 : if ((tmp->start < start) || (tmp->end > end))
972 0 : goto out;
973 :
974 0 : res->start = start;
975 0 : res->end = end;
976 0 : result = 0;
977 :
978 0 : out:
979 0 : return result;
980 : }
981 :
982 : /**
983 : * adjust_resource - modify a resource's start and size
984 : * @res: resource to modify
985 : * @start: new start value
986 : * @size: new size
987 : *
988 : * Given an existing resource, change its start and size to match the
989 : * arguments. Returns 0 on success, -EBUSY if it can't fit.
990 : * Existing children of the resource are assumed to be immutable.
991 : */
992 0 : int adjust_resource(struct resource *res, resource_size_t start,
993 : resource_size_t size)
994 : {
995 0 : int result;
996 :
997 0 : write_lock(&resource_lock);
998 0 : result = __adjust_resource(res, start, size);
999 0 : write_unlock(&resource_lock);
1000 0 : return result;
1001 : }
1002 : EXPORT_SYMBOL(adjust_resource);
1003 :
1004 : static void __init
1005 0 : __reserve_region_with_split(struct resource *root, resource_size_t start,
1006 : resource_size_t end, const char *name)
1007 : {
1008 0 : struct resource *parent = root;
1009 0 : struct resource *conflict;
1010 0 : struct resource *res = alloc_resource(GFP_ATOMIC);
1011 0 : struct resource *next_res = NULL;
1012 0 : int type = resource_type(root);
1013 :
1014 0 : if (!res)
1015 : return;
1016 :
1017 0 : res->name = name;
1018 0 : res->start = start;
1019 0 : res->end = end;
1020 0 : res->flags = type | IORESOURCE_BUSY;
1021 0 : res->desc = IORES_DESC_NONE;
1022 :
1023 0 : while (1) {
1024 :
1025 0 : conflict = __request_resource(parent, res);
1026 0 : if (!conflict) {
1027 0 : if (!next_res)
1028 : break;
1029 0 : res = next_res;
1030 0 : next_res = NULL;
1031 0 : continue;
1032 : }
1033 :
1034 : /* conflict covered whole area */
1035 0 : if (conflict->start <= res->start &&
1036 0 : conflict->end >= res->end) {
1037 0 : free_resource(res);
1038 0 : WARN_ON(next_res);
1039 : break;
1040 : }
1041 :
1042 : /* failed, split and try again */
1043 0 : if (conflict->start > res->start) {
1044 0 : end = res->end;
1045 0 : res->end = conflict->start - 1;
1046 0 : if (conflict->end < end) {
1047 0 : next_res = alloc_resource(GFP_ATOMIC);
1048 0 : if (!next_res) {
1049 0 : free_resource(res);
1050 0 : break;
1051 : }
1052 0 : next_res->name = name;
1053 0 : next_res->start = conflict->end + 1;
1054 0 : next_res->end = end;
1055 0 : next_res->flags = type | IORESOURCE_BUSY;
1056 0 : next_res->desc = IORES_DESC_NONE;
1057 : }
1058 : } else {
1059 0 : res->start = conflict->end + 1;
1060 : }
1061 : }
1062 :
1063 : }
1064 :
1065 : void __init
1066 0 : reserve_region_with_split(struct resource *root, resource_size_t start,
1067 : resource_size_t end, const char *name)
1068 : {
1069 0 : int abort = 0;
1070 :
1071 0 : write_lock(&resource_lock);
1072 0 : if (root->start > start || root->end < end) {
1073 0 : pr_err("requested range [0x%llx-0x%llx] not in root %pr\n",
1074 : (unsigned long long)start, (unsigned long long)end,
1075 : root);
1076 0 : if (start > root->end || end < root->start)
1077 : abort = 1;
1078 : else {
1079 0 : if (end > root->end)
1080 : end = root->end;
1081 0 : if (start < root->start)
1082 : start = root->start;
1083 0 : pr_err("fixing request to [0x%llx-0x%llx]\n",
1084 : (unsigned long long)start,
1085 : (unsigned long long)end);
1086 : }
1087 0 : dump_stack();
1088 : }
1089 0 : if (!abort)
1090 0 : __reserve_region_with_split(root, start, end, name);
1091 0 : write_unlock(&resource_lock);
1092 0 : }
1093 :
1094 : /**
1095 : * resource_alignment - calculate resource's alignment
1096 : * @res: resource pointer
1097 : *
1098 : * Returns alignment on success, 0 (invalid alignment) on failure.
1099 : */
1100 0 : resource_size_t resource_alignment(struct resource *res)
1101 : {
1102 0 : switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
1103 : case IORESOURCE_SIZEALIGN:
1104 0 : return resource_size(res);
1105 0 : case IORESOURCE_STARTALIGN:
1106 0 : return res->start;
1107 : default:
1108 : return 0;
1109 : }
1110 : }
1111 :
1112 : /*
1113 : * This is compatibility stuff for IO resources.
1114 : *
1115 : * Note how this, unlike the above, knows about
1116 : * the IO flag meanings (busy etc).
1117 : *
1118 : * request_region creates a new busy region.
1119 : *
1120 : * release_region releases a matching busy region.
1121 : */
1122 :
1123 : static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
1124 :
1125 : static struct inode *iomem_inode;
1126 :
1127 : #ifdef CONFIG_IO_STRICT_DEVMEM
1128 : static void revoke_iomem(struct resource *res)
1129 : {
1130 : /* pairs with smp_store_release() in iomem_init_inode() */
1131 : struct inode *inode = smp_load_acquire(&iomem_inode);
1132 :
1133 : /*
1134 : * Check that the initialization has completed. Losing the race
1135 : * is ok because it means drivers are claiming resources before
1136 : * the fs_initcall level of init and prevent iomem_get_mapping users
1137 : * from establishing mappings.
1138 : */
1139 : if (!inode)
1140 : return;
1141 :
1142 : /*
1143 : * The expectation is that the driver has successfully marked
1144 : * the resource busy by this point, so devmem_is_allowed()
1145 : * should start returning false, however for performance this
1146 : * does not iterate the entire resource range.
1147 : */
1148 : if (devmem_is_allowed(PHYS_PFN(res->start)) &&
1149 : devmem_is_allowed(PHYS_PFN(res->end))) {
1150 : /*
1151 : * *cringe* iomem=relaxed says "go ahead, what's the
1152 : * worst that can happen?"
1153 : */
1154 : return;
1155 : }
1156 :
1157 : unmap_mapping_range(inode->i_mapping, res->start, resource_size(res), 1);
1158 : }
1159 : #else
1160 : static void revoke_iomem(struct resource *res) {}
1161 : #endif
1162 :
1163 0 : struct address_space *iomem_get_mapping(void)
1164 : {
1165 : /*
1166 : * This function is only called from file open paths, hence guaranteed
1167 : * that fs_initcalls have completed and no need to check for NULL. But
1168 : * since revoke_iomem can be called before the initcall we still need
1169 : * the barrier to appease checkers.
1170 : */
1171 0 : return smp_load_acquire(&iomem_inode)->i_mapping;
1172 : }
1173 :
1174 : /**
1175 : * __request_region - create a new busy resource region
1176 : * @parent: parent resource descriptor
1177 : * @start: resource start address
1178 : * @n: resource region size
1179 : * @name: reserving caller's ID string
1180 : * @flags: IO resource flags
1181 : */
1182 7 : struct resource * __request_region(struct resource *parent,
1183 : resource_size_t start, resource_size_t n,
1184 : const char *name, int flags)
1185 : {
1186 7 : DECLARE_WAITQUEUE(wait, current);
1187 7 : struct resource *res = alloc_resource(GFP_KERNEL);
1188 7 : struct resource *orig_parent = parent;
1189 :
1190 7 : if (!res)
1191 : return NULL;
1192 :
1193 7 : res->name = name;
1194 7 : res->start = start;
1195 7 : res->end = start + n - 1;
1196 :
1197 7 : write_lock(&resource_lock);
1198 :
1199 10 : for (;;) {
1200 10 : struct resource *conflict;
1201 :
1202 10 : res->flags = resource_type(parent) | resource_ext_type(parent);
1203 10 : res->flags |= IORESOURCE_BUSY | flags;
1204 10 : res->desc = parent->desc;
1205 :
1206 10 : conflict = __request_resource(parent, res);
1207 10 : if (!conflict)
1208 : break;
1209 : /*
1210 : * mm/hmm.c reserves physical addresses which then
1211 : * become unavailable to other users. Conflicts are
1212 : * not expected. Warn to aid debugging if encountered.
1213 : */
1214 3 : if (conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) {
1215 0 : pr_warn("Unaddressable device %s %pR conflicts with %pR",
1216 : conflict->name, conflict, res);
1217 : }
1218 3 : if (conflict != parent) {
1219 3 : if (!(conflict->flags & IORESOURCE_BUSY)) {
1220 3 : parent = conflict;
1221 3 : continue;
1222 : }
1223 : }
1224 0 : if (conflict->flags & flags & IORESOURCE_MUXED) {
1225 0 : add_wait_queue(&muxed_resource_wait, &wait);
1226 0 : write_unlock(&resource_lock);
1227 0 : set_current_state(TASK_UNINTERRUPTIBLE);
1228 0 : schedule();
1229 0 : remove_wait_queue(&muxed_resource_wait, &wait);
1230 0 : write_lock(&resource_lock);
1231 0 : continue;
1232 : }
1233 : /* Uhhuh, that didn't work out.. */
1234 0 : free_resource(res);
1235 0 : res = NULL;
1236 0 : break;
1237 : }
1238 7 : write_unlock(&resource_lock);
1239 :
1240 7 : if (res && orig_parent == &iomem_resource)
1241 7 : revoke_iomem(res);
1242 :
1243 7 : return res;
1244 : }
1245 : EXPORT_SYMBOL(__request_region);
1246 :
1247 : /**
1248 : * __release_region - release a previously reserved resource region
1249 : * @parent: parent resource descriptor
1250 : * @start: resource start address
1251 : * @n: resource region size
1252 : *
1253 : * The described resource region must match a currently busy region.
1254 : */
1255 4 : void __release_region(struct resource *parent, resource_size_t start,
1256 : resource_size_t n)
1257 : {
1258 4 : struct resource **p;
1259 4 : resource_size_t end;
1260 :
1261 4 : p = &parent->child;
1262 4 : end = start + n - 1;
1263 :
1264 4 : write_lock(&resource_lock);
1265 :
1266 44 : for (;;) {
1267 44 : struct resource *res = *p;
1268 :
1269 44 : if (!res)
1270 : break;
1271 44 : if (res->start <= start && res->end >= end) {
1272 5 : if (!(res->flags & IORESOURCE_BUSY)) {
1273 1 : p = &res->child;
1274 1 : continue;
1275 : }
1276 4 : if (res->start != start || res->end != end)
1277 : break;
1278 4 : *p = res->sibling;
1279 4 : write_unlock(&resource_lock);
1280 4 : if (res->flags & IORESOURCE_MUXED)
1281 0 : wake_up(&muxed_resource_wait);
1282 4 : free_resource(res);
1283 4 : return;
1284 : }
1285 39 : p = &res->sibling;
1286 : }
1287 :
1288 0 : write_unlock(&resource_lock);
1289 :
1290 0 : printk(KERN_WARNING "Trying to free nonexistent resource "
1291 : "<%016llx-%016llx>\n", (unsigned long long)start,
1292 : (unsigned long long)end);
1293 : }
1294 : EXPORT_SYMBOL(__release_region);
1295 :
1296 : #ifdef CONFIG_MEMORY_HOTREMOVE
1297 : /**
1298 : * release_mem_region_adjustable - release a previously reserved memory region
1299 : * @start: resource start address
1300 : * @size: resource region size
1301 : *
1302 : * This interface is intended for memory hot-delete. The requested region
1303 : * is released from a currently busy memory resource. The requested region
1304 : * must either match exactly or fit into a single busy resource entry. In
1305 : * the latter case, the remaining resource is adjusted accordingly.
1306 : * Existing children of the busy memory resource must be immutable in the
1307 : * request.
1308 : *
1309 : * Note:
1310 : * - Additional release conditions, such as overlapping region, can be
1311 : * supported after they are confirmed as valid cases.
1312 : * - When a busy memory resource gets split into two entries, the code
1313 : * assumes that all children remain in the lower address entry for
1314 : * simplicity. Enhance this logic when necessary.
1315 : */
1316 : void release_mem_region_adjustable(resource_size_t start, resource_size_t size)
1317 : {
1318 : struct resource *parent = &iomem_resource;
1319 : struct resource *new_res = NULL;
1320 : bool alloc_nofail = false;
1321 : struct resource **p;
1322 : struct resource *res;
1323 : resource_size_t end;
1324 :
1325 : end = start + size - 1;
1326 : if (WARN_ON_ONCE((start < parent->start) || (end > parent->end)))
1327 : return;
1328 :
1329 : /*
1330 : * We free up quite a lot of memory on memory hotunplug (esp., memap),
1331 : * just before releasing the region. This is highly unlikely to
1332 : * fail - let's play save and make it never fail as the caller cannot
1333 : * perform any error handling (e.g., trying to re-add memory will fail
1334 : * similarly).
1335 : */
1336 : retry:
1337 : new_res = alloc_resource(GFP_KERNEL | (alloc_nofail ? __GFP_NOFAIL : 0));
1338 :
1339 : p = &parent->child;
1340 : write_lock(&resource_lock);
1341 :
1342 : while ((res = *p)) {
1343 : if (res->start >= end)
1344 : break;
1345 :
1346 : /* look for the next resource if it does not fit into */
1347 : if (res->start > start || res->end < end) {
1348 : p = &res->sibling;
1349 : continue;
1350 : }
1351 :
1352 : /*
1353 : * All memory regions added from memory-hotplug path have the
1354 : * flag IORESOURCE_SYSTEM_RAM. If the resource does not have
1355 : * this flag, we know that we are dealing with a resource coming
1356 : * from HMM/devm. HMM/devm use another mechanism to add/release
1357 : * a resource. This goes via devm_request_mem_region and
1358 : * devm_release_mem_region.
1359 : * HMM/devm take care to release their resources when they want,
1360 : * so if we are dealing with them, let us just back off here.
1361 : */
1362 : if (!(res->flags & IORESOURCE_SYSRAM)) {
1363 : break;
1364 : }
1365 :
1366 : if (!(res->flags & IORESOURCE_MEM))
1367 : break;
1368 :
1369 : if (!(res->flags & IORESOURCE_BUSY)) {
1370 : p = &res->child;
1371 : continue;
1372 : }
1373 :
1374 : /* found the target resource; let's adjust accordingly */
1375 : if (res->start == start && res->end == end) {
1376 : /* free the whole entry */
1377 : *p = res->sibling;
1378 : free_resource(res);
1379 : } else if (res->start == start && res->end != end) {
1380 : /* adjust the start */
1381 : WARN_ON_ONCE(__adjust_resource(res, end + 1,
1382 : res->end - end));
1383 : } else if (res->start != start && res->end == end) {
1384 : /* adjust the end */
1385 : WARN_ON_ONCE(__adjust_resource(res, res->start,
1386 : start - res->start));
1387 : } else {
1388 : /* split into two entries - we need a new resource */
1389 : if (!new_res) {
1390 : new_res = alloc_resource(GFP_ATOMIC);
1391 : if (!new_res) {
1392 : alloc_nofail = true;
1393 : write_unlock(&resource_lock);
1394 : goto retry;
1395 : }
1396 : }
1397 : new_res->name = res->name;
1398 : new_res->start = end + 1;
1399 : new_res->end = res->end;
1400 : new_res->flags = res->flags;
1401 : new_res->desc = res->desc;
1402 : new_res->parent = res->parent;
1403 : new_res->sibling = res->sibling;
1404 : new_res->child = NULL;
1405 :
1406 : if (WARN_ON_ONCE(__adjust_resource(res, res->start,
1407 : start - res->start)))
1408 : break;
1409 : res->sibling = new_res;
1410 : new_res = NULL;
1411 : }
1412 :
1413 : break;
1414 : }
1415 :
1416 : write_unlock(&resource_lock);
1417 : free_resource(new_res);
1418 : }
1419 : #endif /* CONFIG_MEMORY_HOTREMOVE */
1420 :
1421 : #ifdef CONFIG_MEMORY_HOTPLUG
1422 : static bool system_ram_resources_mergeable(struct resource *r1,
1423 : struct resource *r2)
1424 : {
1425 : /* We assume either r1 or r2 is IORESOURCE_SYSRAM_MERGEABLE. */
1426 : return r1->flags == r2->flags && r1->end + 1 == r2->start &&
1427 : r1->name == r2->name && r1->desc == r2->desc &&
1428 : !r1->child && !r2->child;
1429 : }
1430 :
1431 : /**
1432 : * merge_system_ram_resource - mark the System RAM resource mergeable and try to
1433 : * merge it with adjacent, mergeable resources
1434 : * @res: resource descriptor
1435 : *
1436 : * This interface is intended for memory hotplug, whereby lots of contiguous
1437 : * system ram resources are added (e.g., via add_memory*()) by a driver, and
1438 : * the actual resource boundaries are not of interest (e.g., it might be
1439 : * relevant for DIMMs). Only resources that are marked mergeable, that have the
1440 : * same parent, and that don't have any children are considered. All mergeable
1441 : * resources must be immutable during the request.
1442 : *
1443 : * Note:
1444 : * - The caller has to make sure that no pointers to resources that are
1445 : * marked mergeable are used anymore after this call - the resource might
1446 : * be freed and the pointer might be stale!
1447 : * - release_mem_region_adjustable() will split on demand on memory hotunplug
1448 : */
1449 : void merge_system_ram_resource(struct resource *res)
1450 : {
1451 : const unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
1452 : struct resource *cur;
1453 :
1454 : if (WARN_ON_ONCE((res->flags & flags) != flags))
1455 : return;
1456 :
1457 : write_lock(&resource_lock);
1458 : res->flags |= IORESOURCE_SYSRAM_MERGEABLE;
1459 :
1460 : /* Try to merge with next item in the list. */
1461 : cur = res->sibling;
1462 : if (cur && system_ram_resources_mergeable(res, cur)) {
1463 : res->end = cur->end;
1464 : res->sibling = cur->sibling;
1465 : free_resource(cur);
1466 : }
1467 :
1468 : /* Try to merge with previous item in the list. */
1469 : cur = res->parent->child;
1470 : while (cur && cur->sibling != res)
1471 : cur = cur->sibling;
1472 : if (cur && system_ram_resources_mergeable(cur, res)) {
1473 : cur->end = res->end;
1474 : cur->sibling = res->sibling;
1475 : free_resource(res);
1476 : }
1477 : write_unlock(&resource_lock);
1478 : }
1479 : #endif /* CONFIG_MEMORY_HOTPLUG */
1480 :
1481 : /*
1482 : * Managed region resource
1483 : */
1484 0 : static void devm_resource_release(struct device *dev, void *ptr)
1485 : {
1486 0 : struct resource **r = ptr;
1487 :
1488 0 : release_resource(*r);
1489 0 : }
1490 :
1491 : /**
1492 : * devm_request_resource() - request and reserve an I/O or memory resource
1493 : * @dev: device for which to request the resource
1494 : * @root: root of the resource tree from which to request the resource
1495 : * @new: descriptor of the resource to request
1496 : *
1497 : * This is a device-managed version of request_resource(). There is usually
1498 : * no need to release resources requested by this function explicitly since
1499 : * that will be taken care of when the device is unbound from its driver.
1500 : * If for some reason the resource needs to be released explicitly, because
1501 : * of ordering issues for example, drivers must call devm_release_resource()
1502 : * rather than the regular release_resource().
1503 : *
1504 : * When a conflict is detected between any existing resources and the newly
1505 : * requested resource, an error message will be printed.
1506 : *
1507 : * Returns 0 on success or a negative error code on failure.
1508 : */
1509 0 : int devm_request_resource(struct device *dev, struct resource *root,
1510 : struct resource *new)
1511 : {
1512 0 : struct resource *conflict, **ptr;
1513 :
1514 0 : ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL);
1515 0 : if (!ptr)
1516 : return -ENOMEM;
1517 :
1518 0 : *ptr = new;
1519 :
1520 0 : conflict = request_resource_conflict(root, new);
1521 0 : if (conflict) {
1522 0 : dev_err(dev, "resource collision: %pR conflicts with %s %pR\n",
1523 : new, conflict->name, conflict);
1524 0 : devres_free(ptr);
1525 0 : return -EBUSY;
1526 : }
1527 :
1528 0 : devres_add(dev, ptr);
1529 0 : return 0;
1530 : }
1531 : EXPORT_SYMBOL(devm_request_resource);
1532 :
1533 0 : static int devm_resource_match(struct device *dev, void *res, void *data)
1534 : {
1535 0 : struct resource **ptr = res;
1536 :
1537 0 : return *ptr == data;
1538 : }
1539 :
1540 : /**
1541 : * devm_release_resource() - release a previously requested resource
1542 : * @dev: device for which to release the resource
1543 : * @new: descriptor of the resource to release
1544 : *
1545 : * Releases a resource previously requested using devm_request_resource().
1546 : */
1547 0 : void devm_release_resource(struct device *dev, struct resource *new)
1548 : {
1549 0 : WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match,
1550 : new));
1551 0 : }
1552 : EXPORT_SYMBOL(devm_release_resource);
1553 :
1554 : struct region_devres {
1555 : struct resource *parent;
1556 : resource_size_t start;
1557 : resource_size_t n;
1558 : };
1559 :
1560 0 : static void devm_region_release(struct device *dev, void *res)
1561 : {
1562 0 : struct region_devres *this = res;
1563 :
1564 0 : __release_region(this->parent, this->start, this->n);
1565 0 : }
1566 :
1567 0 : static int devm_region_match(struct device *dev, void *res, void *match_data)
1568 : {
1569 0 : struct region_devres *this = res, *match = match_data;
1570 :
1571 0 : return this->parent == match->parent &&
1572 0 : this->start == match->start && this->n == match->n;
1573 : }
1574 :
1575 : struct resource *
1576 2 : __devm_request_region(struct device *dev, struct resource *parent,
1577 : resource_size_t start, resource_size_t n, const char *name)
1578 : {
1579 2 : struct region_devres *dr = NULL;
1580 2 : struct resource *res;
1581 :
1582 2 : dr = devres_alloc(devm_region_release, sizeof(struct region_devres),
1583 : GFP_KERNEL);
1584 2 : if (!dr)
1585 : return NULL;
1586 :
1587 2 : dr->parent = parent;
1588 2 : dr->start = start;
1589 2 : dr->n = n;
1590 :
1591 2 : res = __request_region(parent, start, n, name, 0);
1592 2 : if (res)
1593 2 : devres_add(dev, dr);
1594 : else
1595 0 : devres_free(dr);
1596 :
1597 : return res;
1598 : }
1599 : EXPORT_SYMBOL(__devm_request_region);
1600 :
1601 0 : void __devm_release_region(struct device *dev, struct resource *parent,
1602 : resource_size_t start, resource_size_t n)
1603 : {
1604 0 : struct region_devres match_data = { parent, start, n };
1605 :
1606 0 : __release_region(parent, start, n);
1607 0 : WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
1608 : &match_data));
1609 0 : }
1610 : EXPORT_SYMBOL(__devm_release_region);
1611 :
1612 : /*
1613 : * Reserve I/O ports or memory based on "reserve=" kernel parameter.
1614 : */
1615 : #define MAXRESERVE 4
1616 0 : static int __init reserve_setup(char *str)
1617 : {
1618 0 : static int reserved;
1619 0 : static struct resource reserve[MAXRESERVE];
1620 :
1621 0 : for (;;) {
1622 0 : unsigned int io_start, io_num;
1623 0 : int x = reserved;
1624 0 : struct resource *parent;
1625 :
1626 0 : if (get_option(&str, &io_start) != 2)
1627 : break;
1628 0 : if (get_option(&str, &io_num) == 0)
1629 : break;
1630 0 : if (x < MAXRESERVE) {
1631 0 : struct resource *res = reserve + x;
1632 :
1633 : /*
1634 : * If the region starts below 0x10000, we assume it's
1635 : * I/O port space; otherwise assume it's memory.
1636 : */
1637 0 : if (io_start < 0x10000) {
1638 0 : res->flags = IORESOURCE_IO;
1639 0 : parent = &ioport_resource;
1640 : } else {
1641 0 : res->flags = IORESOURCE_MEM;
1642 0 : parent = &iomem_resource;
1643 : }
1644 0 : res->name = "reserved";
1645 0 : res->start = io_start;
1646 0 : res->end = io_start + io_num - 1;
1647 0 : res->flags |= IORESOURCE_BUSY;
1648 0 : res->desc = IORES_DESC_NONE;
1649 0 : res->child = NULL;
1650 0 : if (request_resource(parent, res) == 0)
1651 0 : reserved = x+1;
1652 : }
1653 : }
1654 0 : return 1;
1655 : }
1656 : __setup("reserve=", reserve_setup);
1657 :
1658 : /*
1659 : * Check if the requested addr and size spans more than any slot in the
1660 : * iomem resource tree.
1661 : */
1662 2 : int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
1663 : {
1664 2 : struct resource *p = &iomem_resource;
1665 2 : int err = 0;
1666 2 : loff_t l;
1667 :
1668 2 : read_lock(&resource_lock);
1669 60 : for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1670 : /*
1671 : * We can probably skip the resources without
1672 : * IORESOURCE_IO attribute?
1673 : */
1674 29 : if (p->start >= addr + size)
1675 2 : continue;
1676 27 : if (p->end < addr)
1677 23 : continue;
1678 4 : if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
1679 4 : PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
1680 4 : continue;
1681 : /*
1682 : * if a resource is "BUSY", it's not a hardware resource
1683 : * but a driver mapping of such a resource; we don't want
1684 : * to warn for those; some drivers legitimately map only
1685 : * partial hardware resources. (example: vesafb)
1686 : */
1687 0 : if (p->flags & IORESOURCE_BUSY)
1688 0 : continue;
1689 :
1690 0 : printk(KERN_WARNING "resource sanity check: requesting [mem %#010llx-%#010llx], which spans more than %s %pR\n",
1691 : (unsigned long long)addr,
1692 : (unsigned long long)(addr + size - 1),
1693 : p->name, p);
1694 0 : err = -1;
1695 0 : break;
1696 : }
1697 2 : read_unlock(&resource_lock);
1698 :
1699 2 : return err;
1700 : }
1701 :
1702 : #ifdef CONFIG_STRICT_DEVMEM
1703 : static int strict_iomem_checks = 1;
1704 : #else
1705 : static int strict_iomem_checks;
1706 : #endif
1707 :
1708 : /*
1709 : * check if an address is reserved in the iomem resource tree
1710 : * returns true if reserved, false if not reserved.
1711 : */
1712 0 : bool iomem_is_exclusive(u64 addr)
1713 : {
1714 0 : struct resource *p = &iomem_resource;
1715 0 : bool err = false;
1716 0 : loff_t l;
1717 0 : int size = PAGE_SIZE;
1718 :
1719 0 : if (!strict_iomem_checks)
1720 : return false;
1721 :
1722 0 : addr = addr & PAGE_MASK;
1723 :
1724 0 : read_lock(&resource_lock);
1725 0 : for (p = p->child; p ; p = r_next(NULL, p, &l)) {
1726 : /*
1727 : * We can probably skip the resources without
1728 : * IORESOURCE_IO attribute?
1729 : */
1730 0 : if (p->start >= addr + size)
1731 : break;
1732 0 : if (p->end < addr)
1733 0 : continue;
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 ((p->flags & IORESOURCE_BUSY) == 0)
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 0 : 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 0 : 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 :
1783 : size = ALIGN(size, 1UL << PA_SECTION_SHIFT);
1784 : end = min_t(unsigned long, base->end, (1UL << MAX_PHYSMEM_BITS) - 1);
1785 : addr = end - size + 1UL;
1786 :
1787 : for (; addr > size && addr >= base->start; addr -= size) {
1788 : if (region_intersects(addr, size, 0, IORES_DESC_NONE) !=
1789 : REGION_DISJOINT)
1790 : continue;
1791 :
1792 : if (dev)
1793 : res = devm_request_mem_region(dev, addr, size, name);
1794 : else
1795 : res = request_mem_region(addr, size, name);
1796 : if (!res)
1797 : return ERR_PTR(-ENOMEM);
1798 : res->desc = IORES_DESC_DEVICE_PRIVATE_MEMORY;
1799 : return res;
1800 : }
1801 :
1802 : return ERR_PTR(-ERANGE);
1803 : }
1804 :
1805 : /**
1806 : * devm_request_free_mem_region - find free region for device private memory
1807 : *
1808 : * @dev: device struct to bind the resource to
1809 : * @size: size in bytes of the device memory to add
1810 : * @base: resource tree to look in
1811 : *
1812 : * This function tries to find an empty range of physical address big enough to
1813 : * contain the new resource, so that it can later be hotplugged as ZONE_DEVICE
1814 : * memory, which in turn allocates struct pages.
1815 : */
1816 : struct resource *devm_request_free_mem_region(struct device *dev,
1817 : struct resource *base, unsigned long size)
1818 : {
1819 : return __request_free_mem_region(dev, base, size, dev_name(dev));
1820 : }
1821 : EXPORT_SYMBOL_GPL(devm_request_free_mem_region);
1822 :
1823 : struct resource *request_free_mem_region(struct resource *base,
1824 : unsigned long size, const char *name)
1825 : {
1826 : return __request_free_mem_region(NULL, base, size, name);
1827 : }
1828 : EXPORT_SYMBOL_GPL(request_free_mem_region);
1829 :
1830 : #endif /* CONFIG_DEVICE_PRIVATE */
1831 :
1832 0 : static int __init strict_iomem(char *str)
1833 : {
1834 0 : if (strstr(str, "relaxed"))
1835 0 : strict_iomem_checks = 0;
1836 0 : if (strstr(str, "strict"))
1837 0 : strict_iomem_checks = 1;
1838 0 : return 1;
1839 : }
1840 :
1841 1 : static int iomem_fs_init_fs_context(struct fs_context *fc)
1842 : {
1843 1 : return init_pseudo(fc, DEVMEM_MAGIC) ? 0 : -ENOMEM;
1844 : }
1845 :
1846 : static struct file_system_type iomem_fs_type = {
1847 : .name = "iomem",
1848 : .owner = THIS_MODULE,
1849 : .init_fs_context = iomem_fs_init_fs_context,
1850 : .kill_sb = kill_anon_super,
1851 : };
1852 :
1853 1 : static int __init iomem_init_inode(void)
1854 : {
1855 1 : static struct vfsmount *iomem_vfs_mount;
1856 1 : static int iomem_fs_cnt;
1857 1 : struct inode *inode;
1858 1 : int rc;
1859 :
1860 1 : rc = simple_pin_fs(&iomem_fs_type, &iomem_vfs_mount, &iomem_fs_cnt);
1861 1 : if (rc < 0) {
1862 0 : pr_err("Cannot mount iomem pseudo filesystem: %d\n", rc);
1863 0 : return rc;
1864 : }
1865 :
1866 1 : inode = alloc_anon_inode(iomem_vfs_mount->mnt_sb);
1867 1 : if (IS_ERR(inode)) {
1868 0 : rc = PTR_ERR(inode);
1869 0 : pr_err("Cannot allocate inode for iomem: %d\n", rc);
1870 0 : simple_release_fs(&iomem_vfs_mount, &iomem_fs_cnt);
1871 0 : return rc;
1872 : }
1873 :
1874 : /*
1875 : * Publish iomem revocation inode initialized.
1876 : * Pairs with smp_load_acquire() in revoke_iomem().
1877 : */
1878 1 : smp_store_release(&iomem_inode, inode);
1879 :
1880 1 : return 0;
1881 : }
1882 :
1883 : fs_initcall(iomem_init_inode);
1884 :
1885 : __setup("iomem=", strict_iomem);
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