Branch data Line data Source code
1 : : // SPDX-License-Identifier: GPL-2.0-only
2 : : #include <linux/bitmap.h>
3 : : #include <linux/bug.h>
4 : : #include <linux/export.h>
5 : : #include <linux/idr.h>
6 : : #include <linux/slab.h>
7 : : #include <linux/spinlock.h>
8 : : #include <linux/xarray.h>
9 : :
10 : : /**
11 : : * idr_alloc_u32() - Allocate an ID.
12 : : * @idr: IDR handle.
13 : : * @ptr: Pointer to be associated with the new ID.
14 : : * @nextid: Pointer to an ID.
15 : : * @max: The maximum ID to allocate (inclusive).
16 : : * @gfp: Memory allocation flags.
17 : : *
18 : : * Allocates an unused ID in the range specified by @nextid and @max.
19 : : * Note that @max is inclusive whereas the @end parameter to idr_alloc()
20 : : * is exclusive. The new ID is assigned to @nextid before the pointer
21 : : * is inserted into the IDR, so if @nextid points into the object pointed
22 : : * to by @ptr, a concurrent lookup will not find an uninitialised ID.
23 : : *
24 : : * The caller should provide their own locking to ensure that two
25 : : * concurrent modifications to the IDR are not possible. Read-only
26 : : * accesses to the IDR may be done under the RCU read lock or may
27 : : * exclude simultaneous writers.
28 : : *
29 : : * Return: 0 if an ID was allocated, -ENOMEM if memory allocation failed,
30 : : * or -ENOSPC if no free IDs could be found. If an error occurred,
31 : : * @nextid is unchanged.
32 : : */
33 : 247984 : int idr_alloc_u32(struct idr *idr, void *ptr, u32 *nextid,
34 : : unsigned long max, gfp_t gfp)
35 : : {
36 : 247984 : struct radix_tree_iter iter;
37 : 247984 : void __rcu **slot;
38 : 247984 : unsigned int base = idr->idr_base;
39 : 247984 : unsigned int id = *nextid;
40 : :
41 [ - + - + ]: 247984 : if (WARN_ON_ONCE(!(idr->idr_rt.xa_flags & ROOT_IS_IDR)))
42 : 0 : idr->idr_rt.xa_flags |= IDR_RT_MARKER;
43 : :
44 [ + - ]: 247984 : id = (id < base) ? 0 : id - base;
45 : 247984 : radix_tree_iter_init(&iter, id);
46 : 247984 : slot = idr_get_free(&idr->idr_rt, &iter, gfp, max - base);
47 [ + + ]: 247984 : if (IS_ERR(slot))
48 : 11 : return PTR_ERR(slot);
49 : :
50 : 247973 : *nextid = iter.index + base;
51 : : /* there is a memory barrier inside radix_tree_iter_replace() */
52 : 247973 : radix_tree_iter_replace(&idr->idr_rt, &iter, slot, ptr);
53 : 247973 : radix_tree_iter_tag_clear(&idr->idr_rt, &iter, IDR_FREE);
54 : :
55 : 247973 : return 0;
56 : : }
57 : : EXPORT_SYMBOL_GPL(idr_alloc_u32);
58 : :
59 : : /**
60 : : * idr_alloc() - Allocate an ID.
61 : : * @idr: IDR handle.
62 : : * @ptr: Pointer to be associated with the new ID.
63 : : * @start: The minimum ID (inclusive).
64 : : * @end: The maximum ID (exclusive).
65 : : * @gfp: Memory allocation flags.
66 : : *
67 : : * Allocates an unused ID in the range specified by @start and @end. If
68 : : * @end is <= 0, it is treated as one larger than %INT_MAX. This allows
69 : : * callers to use @start + N as @end as long as N is within integer range.
70 : : *
71 : : * The caller should provide their own locking to ensure that two
72 : : * concurrent modifications to the IDR are not possible. Read-only
73 : : * accesses to the IDR may be done under the RCU read lock or may
74 : : * exclude simultaneous writers.
75 : : *
76 : : * Return: The newly allocated ID, -ENOMEM if memory allocation failed,
77 : : * or -ENOSPC if no free IDs could be found.
78 : : */
79 : 308 : int idr_alloc(struct idr *idr, void *ptr, int start, int end, gfp_t gfp)
80 : : {
81 : 308 : u32 id = start;
82 : 308 : int ret;
83 : :
84 [ - + + - ]: 308 : if (WARN_ON_ONCE(start < 0))
85 : : return -EINVAL;
86 : :
87 [ + + ]: 308 : ret = idr_alloc_u32(idr, ptr, &id, end > 0 ? end - 1 : INT_MAX, gfp);
88 [ + - ]: 308 : if (ret)
89 : : return ret;
90 : :
91 : 308 : return id;
92 : : }
93 : : EXPORT_SYMBOL_GPL(idr_alloc);
94 : :
95 : : /**
96 : : * idr_alloc_cyclic() - Allocate an ID cyclically.
97 : : * @idr: IDR handle.
98 : : * @ptr: Pointer to be associated with the new ID.
99 : : * @start: The minimum ID (inclusive).
100 : : * @end: The maximum ID (exclusive).
101 : : * @gfp: Memory allocation flags.
102 : : *
103 : : * Allocates an unused ID in the range specified by @nextid and @end. If
104 : : * @end is <= 0, it is treated as one larger than %INT_MAX. This allows
105 : : * callers to use @start + N as @end as long as N is within integer range.
106 : : * The search for an unused ID will start at the last ID allocated and will
107 : : * wrap around to @start if no free IDs are found before reaching @end.
108 : : *
109 : : * The caller should provide their own locking to ensure that two
110 : : * concurrent modifications to the IDR are not possible. Read-only
111 : : * accesses to the IDR may be done under the RCU read lock or may
112 : : * exclude simultaneous writers.
113 : : *
114 : : * Return: The newly allocated ID, -ENOMEM if memory allocation failed,
115 : : * or -ENOSPC if no free IDs could be found.
116 : : */
117 : 247665 : int idr_alloc_cyclic(struct idr *idr, void *ptr, int start, int end, gfp_t gfp)
118 : : {
119 : 247665 : u32 id = idr->idr_next;
120 [ + + ]: 247665 : int err, max = end > 0 ? end - 1 : INT_MAX;
121 : :
122 [ + + ]: 247665 : if ((int)id < start)
123 : 231 : id = start;
124 : :
125 : 247665 : err = idr_alloc_u32(idr, ptr, &id, max, gfp);
126 [ + + + - ]: 247665 : if ((err == -ENOSPC) && (id > start)) {
127 : 11 : id = start;
128 : 11 : err = idr_alloc_u32(idr, ptr, &id, max, gfp);
129 : : }
130 [ + - ]: 247665 : if (err)
131 : : return err;
132 : :
133 : 247665 : idr->idr_next = id + 1;
134 : 247665 : return id;
135 : : }
136 : : EXPORT_SYMBOL(idr_alloc_cyclic);
137 : :
138 : : /**
139 : : * idr_remove() - Remove an ID from the IDR.
140 : : * @idr: IDR handle.
141 : : * @id: Pointer ID.
142 : : *
143 : : * Removes this ID from the IDR. If the ID was not previously in the IDR,
144 : : * this function returns %NULL.
145 : : *
146 : : * Since this function modifies the IDR, the caller should provide their
147 : : * own locking to ensure that concurrent modification of the same IDR is
148 : : * not possible.
149 : : *
150 : : * Return: The pointer formerly associated with this ID.
151 : : */
152 : 78540 : void *idr_remove(struct idr *idr, unsigned long id)
153 : : {
154 : 78540 : return radix_tree_delete_item(&idr->idr_rt, id - idr->idr_base, NULL);
155 : : }
156 : : EXPORT_SYMBOL_GPL(idr_remove);
157 : :
158 : : /**
159 : : * idr_find() - Return pointer for given ID.
160 : : * @idr: IDR handle.
161 : : * @id: Pointer ID.
162 : : *
163 : : * Looks up the pointer associated with this ID. A %NULL pointer may
164 : : * indicate that @id is not allocated or that the %NULL pointer was
165 : : * associated with this ID.
166 : : *
167 : : * This function can be called under rcu_read_lock(), given that the leaf
168 : : * pointers lifetimes are correctly managed.
169 : : *
170 : : * Return: The pointer associated with this ID.
171 : : */
172 : 39996 : void *idr_find(const struct idr *idr, unsigned long id)
173 : : {
174 : 39996 : return radix_tree_lookup(&idr->idr_rt, id - idr->idr_base);
175 : : }
176 : : EXPORT_SYMBOL_GPL(idr_find);
177 : :
178 : : /**
179 : : * idr_for_each() - Iterate through all stored pointers.
180 : : * @idr: IDR handle.
181 : : * @fn: Function to be called for each pointer.
182 : : * @data: Data passed to callback function.
183 : : *
184 : : * The callback function will be called for each entry in @idr, passing
185 : : * the ID, the entry and @data.
186 : : *
187 : : * If @fn returns anything other than %0, the iteration stops and that
188 : : * value is returned from this function.
189 : : *
190 : : * idr_for_each() can be called concurrently with idr_alloc() and
191 : : * idr_remove() if protected by RCU. Newly added entries may not be
192 : : * seen and deleted entries may be seen, but adding and removing entries
193 : : * will not cause other entries to be skipped, nor spurious ones to be seen.
194 : : */
195 : 6215 : int idr_for_each(const struct idr *idr,
196 : : int (*fn)(int id, void *p, void *data), void *data)
197 : : {
198 : 6215 : struct radix_tree_iter iter;
199 : 6215 : void __rcu **slot;
200 : 6215 : int base = idr->idr_base;
201 : :
202 [ - + - + ]: 12430 : radix_tree_for_each_slot(slot, &idr->idr_rt, &iter, 0) {
203 : 0 : int ret;
204 : 0 : unsigned long id = iter.index + base;
205 : :
206 [ # # # # ]: 0 : if (WARN_ON_ONCE(id > INT_MAX))
207 : : break;
208 : 0 : ret = fn(id, rcu_dereference_raw(*slot), data);
209 [ # # ]: 0 : if (ret)
210 : 0 : return ret;
211 : : }
212 : :
213 : : return 0;
214 : : }
215 : : EXPORT_SYMBOL(idr_for_each);
216 : :
217 : : /**
218 : : * idr_get_next_ul() - Find next populated entry.
219 : : * @idr: IDR handle.
220 : : * @nextid: Pointer to an ID.
221 : : *
222 : : * Returns the next populated entry in the tree with an ID greater than
223 : : * or equal to the value pointed to by @nextid. On exit, @nextid is updated
224 : : * to the ID of the found value. To use in a loop, the value pointed to by
225 : : * nextid must be incremented by the user.
226 : : */
227 : 869 : void *idr_get_next_ul(struct idr *idr, unsigned long *nextid)
228 : : {
229 : 869 : struct radix_tree_iter iter;
230 : 869 : void __rcu **slot;
231 : 869 : void *entry = NULL;
232 : 869 : unsigned long base = idr->idr_base;
233 : 869 : unsigned long id = *nextid;
234 : :
235 [ + - ]: 869 : id = (id < base) ? 0 : id - base;
236 [ - + + + ]: 869 : radix_tree_for_each_slot(slot, &idr->idr_rt, &iter, id) {
237 [ - + ]: 726 : entry = rcu_dereference_raw(*slot);
238 [ - + ]: 726 : if (!entry)
239 : 0 : continue;
240 [ - + ]: 726 : if (!xa_is_internal(entry))
241 : : break;
242 [ # # # # ]: 0 : if (slot != &idr->idr_rt.xa_head && !xa_is_retry(entry))
243 : : break;
244 : 0 : slot = radix_tree_iter_retry(&iter);
245 : : }
246 [ + + ]: 869 : if (!slot)
247 : : return NULL;
248 : :
249 : 726 : *nextid = iter.index + base;
250 : 726 : return entry;
251 : : }
252 : : EXPORT_SYMBOL(idr_get_next_ul);
253 : :
254 : : /**
255 : : * idr_get_next() - Find next populated entry.
256 : : * @idr: IDR handle.
257 : : * @nextid: Pointer to an ID.
258 : : *
259 : : * Returns the next populated entry in the tree with an ID greater than
260 : : * or equal to the value pointed to by @nextid. On exit, @nextid is updated
261 : : * to the ID of the found value. To use in a loop, the value pointed to by
262 : : * nextid must be incremented by the user.
263 : : */
264 : 869 : void *idr_get_next(struct idr *idr, int *nextid)
265 : : {
266 : 869 : unsigned long id = *nextid;
267 : 869 : void *entry = idr_get_next_ul(idr, &id);
268 : :
269 [ - + + - ]: 869 : if (WARN_ON_ONCE(id > INT_MAX))
270 : : return NULL;
271 : 869 : *nextid = id;
272 : 869 : return entry;
273 : : }
274 : : EXPORT_SYMBOL(idr_get_next);
275 : :
276 : : /**
277 : : * idr_replace() - replace pointer for given ID.
278 : : * @idr: IDR handle.
279 : : * @ptr: New pointer to associate with the ID.
280 : : * @id: ID to change.
281 : : *
282 : : * Replace the pointer registered with an ID and return the old value.
283 : : * This function can be called under the RCU read lock concurrently with
284 : : * idr_alloc() and idr_remove() (as long as the ID being removed is not
285 : : * the one being replaced!).
286 : : *
287 : : * Returns: the old value on success. %-ENOENT indicates that @id was not
288 : : * found. %-EINVAL indicates that @ptr was not valid.
289 : : */
290 : 54901 : void *idr_replace(struct idr *idr, void *ptr, unsigned long id)
291 : : {
292 : 54901 : struct radix_tree_node *node;
293 : 54901 : void __rcu **slot = NULL;
294 : 54901 : void *entry;
295 : :
296 : 54901 : id -= idr->idr_base;
297 : :
298 : 54901 : entry = __radix_tree_lookup(&idr->idr_rt, id, &node, &slot);
299 [ + - - + ]: 54901 : if (!slot || radix_tree_tag_get(&idr->idr_rt, id, IDR_FREE))
300 : 0 : return ERR_PTR(-ENOENT);
301 : :
302 : 54901 : __radix_tree_replace(&idr->idr_rt, node, slot, ptr);
303 : :
304 : 54901 : return entry;
305 : : }
306 : : EXPORT_SYMBOL(idr_replace);
307 : :
308 : : /**
309 : : * DOC: IDA description
310 : : *
311 : : * The IDA is an ID allocator which does not provide the ability to
312 : : * associate an ID with a pointer. As such, it only needs to store one
313 : : * bit per ID, and so is more space efficient than an IDR. To use an IDA,
314 : : * define it using DEFINE_IDA() (or embed a &struct ida in a data structure,
315 : : * then initialise it using ida_init()). To allocate a new ID, call
316 : : * ida_alloc(), ida_alloc_min(), ida_alloc_max() or ida_alloc_range().
317 : : * To free an ID, call ida_free().
318 : : *
319 : : * ida_destroy() can be used to dispose of an IDA without needing to
320 : : * free the individual IDs in it. You can use ida_is_empty() to find
321 : : * out whether the IDA has any IDs currently allocated.
322 : : *
323 : : * The IDA handles its own locking. It is safe to call any of the IDA
324 : : * functions without synchronisation in your code.
325 : : *
326 : : * IDs are currently limited to the range [0-INT_MAX]. If this is an awkward
327 : : * limitation, it should be quite straightforward to raise the maximum.
328 : : */
329 : :
330 : : /*
331 : : * Developer's notes:
332 : : *
333 : : * The IDA uses the functionality provided by the XArray to store bitmaps in
334 : : * each entry. The XA_FREE_MARK is only cleared when all bits in the bitmap
335 : : * have been set.
336 : : *
337 : : * I considered telling the XArray that each slot is an order-10 node
338 : : * and indexing by bit number, but the XArray can't allow a single multi-index
339 : : * entry in the head, which would significantly increase memory consumption
340 : : * for the IDA. So instead we divide the index by the number of bits in the
341 : : * leaf bitmap before doing a radix tree lookup.
342 : : *
343 : : * As an optimisation, if there are only a few low bits set in any given
344 : : * leaf, instead of allocating a 128-byte bitmap, we store the bits
345 : : * as a value entry. Value entries never have the XA_FREE_MARK cleared
346 : : * because we can always convert them into a bitmap entry.
347 : : *
348 : : * It would be possible to optimise further; once we've run out of a
349 : : * single 128-byte bitmap, we currently switch to a 576-byte node, put
350 : : * the 128-byte bitmap in the first entry and then start allocating extra
351 : : * 128-byte entries. We could instead use the 512 bytes of the node's
352 : : * data as a bitmap before moving to that scheme. I do not believe this
353 : : * is a worthwhile optimisation; Rasmus Villemoes surveyed the current
354 : : * users of the IDA and almost none of them use more than 1024 entries.
355 : : * Those that do use more than the 8192 IDs that the 512 bytes would
356 : : * provide.
357 : : *
358 : : * The IDA always uses a lock to alloc/free. If we add a 'test_bit'
359 : : * equivalent, it will still need locking. Going to RCU lookup would require
360 : : * using RCU to free bitmaps, and that's not trivial without embedding an
361 : : * RCU head in the bitmap, which adds a 2-pointer overhead to each 128-byte
362 : : * bitmap, which is excessive.
363 : : */
364 : :
365 : : /**
366 : : * ida_alloc_range() - Allocate an unused ID.
367 : : * @ida: IDA handle.
368 : : * @min: Lowest ID to allocate.
369 : : * @max: Highest ID to allocate.
370 : : * @gfp: Memory allocation flags.
371 : : *
372 : : * Allocate an ID between @min and @max, inclusive. The allocated ID will
373 : : * not exceed %INT_MAX, even if @max is larger.
374 : : *
375 : : * Context: Any context.
376 : : * Return: The allocated ID, or %-ENOMEM if memory could not be allocated,
377 : : * or %-ENOSPC if there are no free IDs.
378 : : */
379 : 7645 : int ida_alloc_range(struct ida *ida, unsigned int min, unsigned int max,
380 : : gfp_t gfp)
381 : : {
382 : 7645 : XA_STATE(xas, &ida->xa, min / IDA_BITMAP_BITS);
383 : 7645 : unsigned bit = min % IDA_BITMAP_BITS;
384 : 7645 : unsigned long flags;
385 : 7645 : struct ida_bitmap *bitmap, *alloc = NULL;
386 : :
387 [ + - ]: 7645 : if ((int)min < 0)
388 : : return -ENOSPC;
389 : :
390 [ + + ]: 7645 : if ((int)max < 0)
391 : 3410 : max = INT_MAX;
392 : :
393 : 7645 : retry:
394 : 7645 : xas_lock_irqsave(&xas, flags);
395 : 7645 : next:
396 : 7645 : bitmap = xas_find_marked(&xas, max / IDA_BITMAP_BITS, XA_FREE_MARK);
397 [ - + ]: 7645 : if (xas.xa_index > min / IDA_BITMAP_BITS)
398 : 0 : bit = 0;
399 [ - + ]: 7645 : if (xas.xa_index * IDA_BITMAP_BITS + bit > max)
400 : 0 : goto nospc;
401 : :
402 [ + + ]: 7645 : if (xa_is_value(bitmap)) {
403 [ + - ]: 2915 : unsigned long tmp = xa_to_value(bitmap);
404 : :
405 [ + - ]: 2915 : if (bit < BITS_PER_XA_VALUE) {
406 : 2915 : bit = find_next_zero_bit(&tmp, BITS_PER_XA_VALUE, bit);
407 [ - + ]: 2915 : if (xas.xa_index * IDA_BITMAP_BITS + bit > max)
408 : 0 : goto nospc;
409 [ + + ]: 2915 : if (bit < BITS_PER_XA_VALUE) {
410 : 2882 : tmp |= 1UL << bit;
411 [ - + ]: 2882 : xas_store(&xas, xa_mk_value(tmp));
412 : 2882 : goto out;
413 : : }
414 : : }
415 : 33 : bitmap = alloc;
416 [ + - ]: 33 : if (!bitmap)
417 : 33 : bitmap = kzalloc(sizeof(*bitmap), GFP_NOWAIT);
418 [ - + ]: 33 : if (!bitmap)
419 : 0 : goto alloc;
420 : 33 : bitmap->bitmap[0] = tmp;
421 : 33 : xas_store(&xas, bitmap);
422 [ - + - - ]: 33 : if (xas_error(&xas)) {
423 : 0 : bitmap->bitmap[0] = 0;
424 : 0 : goto out;
425 : : }
426 : : }
427 : :
428 [ + + ]: 4763 : if (bitmap) {
429 : 4554 : bit = find_next_zero_bit(bitmap->bitmap, IDA_BITMAP_BITS, bit);
430 [ - + ]: 4554 : if (xas.xa_index * IDA_BITMAP_BITS + bit > max)
431 : 0 : goto nospc;
432 [ - + ]: 4554 : if (bit == IDA_BITMAP_BITS)
433 : 0 : goto next;
434 : :
435 : 4554 : __set_bit(bit, bitmap->bitmap);
436 [ - + ]: 4554 : if (bitmap_full(bitmap->bitmap, IDA_BITMAP_BITS))
437 : 0 : xas_clear_mark(&xas, XA_FREE_MARK);
438 : : } else {
439 [ + + ]: 209 : if (bit < BITS_PER_XA_VALUE) {
440 [ - + ]: 198 : bitmap = xa_mk_value(1UL << bit);
441 : : } else {
442 : 11 : bitmap = alloc;
443 [ + - ]: 11 : if (!bitmap)
444 : 11 : bitmap = kzalloc(sizeof(*bitmap), GFP_NOWAIT);
445 [ - + ]: 11 : if (!bitmap)
446 : 0 : goto alloc;
447 : 11 : __set_bit(bit, bitmap->bitmap);
448 : : }
449 : 209 : xas_store(&xas, bitmap);
450 : : }
451 : 7645 : out:
452 : 7645 : xas_unlock_irqrestore(&xas, flags);
453 [ - + ]: 7645 : if (xas_nomem(&xas, gfp)) {
454 : 0 : xas.xa_index = min / IDA_BITMAP_BITS;
455 : 0 : bit = min % IDA_BITMAP_BITS;
456 : 0 : goto retry;
457 : : }
458 [ + - ]: 7645 : if (bitmap != alloc)
459 : 7645 : kfree(alloc);
460 [ - + - - ]: 7645 : if (xas_error(&xas))
461 [ # # ]: 0 : return xas_error(&xas);
462 : 7645 : return xas.xa_index * IDA_BITMAP_BITS + bit;
463 : 0 : alloc:
464 : 0 : xas_unlock_irqrestore(&xas, flags);
465 : 0 : alloc = kzalloc(sizeof(*bitmap), gfp);
466 [ # # ]: 0 : if (!alloc)
467 : : return -ENOMEM;
468 : 0 : xas_set(&xas, min / IDA_BITMAP_BITS);
469 : 0 : bit = min % IDA_BITMAP_BITS;
470 : 0 : goto retry;
471 : 0 : nospc:
472 : 0 : xas_unlock_irqrestore(&xas, flags);
473 : 0 : return -ENOSPC;
474 : : }
475 : : EXPORT_SYMBOL(ida_alloc_range);
476 : :
477 : : /**
478 : : * ida_free() - Release an allocated ID.
479 : : * @ida: IDA handle.
480 : : * @id: Previously allocated ID.
481 : : *
482 : : * Context: Any context.
483 : : */
484 : 110 : void ida_free(struct ida *ida, unsigned int id)
485 : : {
486 : 110 : XA_STATE(xas, &ida->xa, id / IDA_BITMAP_BITS);
487 : 110 : unsigned bit = id % IDA_BITMAP_BITS;
488 : 110 : struct ida_bitmap *bitmap;
489 : 110 : unsigned long flags;
490 : :
491 [ - + ]: 110 : BUG_ON((int)id < 0);
492 : :
493 : 110 : xas_lock_irqsave(&xas, flags);
494 : 110 : bitmap = xas_load(&xas);
495 : :
496 [ + + ]: 110 : if (xa_is_value(bitmap)) {
497 [ - + ]: 44 : unsigned long v = xa_to_value(bitmap);
498 [ - + ]: 44 : if (bit >= BITS_PER_XA_VALUE)
499 : 0 : goto err;
500 [ - + ]: 44 : if (!(v & (1UL << bit)))
501 : 0 : goto err;
502 : 44 : v &= ~(1UL << bit);
503 [ - + ]: 44 : if (!v)
504 : 0 : goto delete;
505 : 44 : xas_store(&xas, xa_mk_value(v));
506 : : } else {
507 [ - + ]: 66 : if (!test_bit(bit, bitmap->bitmap))
508 : 0 : goto err;
509 : 66 : __clear_bit(bit, bitmap->bitmap);
510 : 66 : xas_set_mark(&xas, XA_FREE_MARK);
511 [ - + ]: 66 : if (bitmap_empty(bitmap->bitmap, IDA_BITMAP_BITS)) {
512 : 0 : kfree(bitmap);
513 : 0 : delete:
514 : 0 : xas_store(&xas, NULL);
515 : : }
516 : : }
517 : 110 : xas_unlock_irqrestore(&xas, flags);
518 : 110 : return;
519 : 0 : err:
520 : 0 : xas_unlock_irqrestore(&xas, flags);
521 : 0 : WARN(1, "ida_free called for id=%d which is not allocated.\n", id);
522 : : }
523 : : EXPORT_SYMBOL(ida_free);
524 : :
525 : : /**
526 : : * ida_destroy() - Free all IDs.
527 : : * @ida: IDA handle.
528 : : *
529 : : * Calling this function frees all IDs and releases all resources used
530 : : * by an IDA. When this call returns, the IDA is empty and can be reused
531 : : * or freed. If the IDA is already empty, there is no need to call this
532 : : * function.
533 : : *
534 : : * Context: Any context.
535 : : */
536 : 0 : void ida_destroy(struct ida *ida)
537 : : {
538 : 0 : XA_STATE(xas, &ida->xa, 0);
539 : 0 : struct ida_bitmap *bitmap;
540 : 0 : unsigned long flags;
541 : :
542 : 0 : xas_lock_irqsave(&xas, flags);
543 [ # # ]: 0 : xas_for_each(&xas, bitmap, ULONG_MAX) {
544 [ # # ]: 0 : if (!xa_is_value(bitmap))
545 : 0 : kfree(bitmap);
546 : 0 : xas_store(&xas, NULL);
547 : : }
548 : 0 : xas_unlock_irqrestore(&xas, flags);
549 : 0 : }
550 : : EXPORT_SYMBOL(ida_destroy);
551 : :
552 : : #ifndef __KERNEL__
553 : : extern void xa_dump_index(unsigned long index, unsigned int shift);
554 : : #define IDA_CHUNK_SHIFT ilog2(IDA_BITMAP_BITS)
555 : :
556 : : static void ida_dump_entry(void *entry, unsigned long index)
557 : : {
558 : : unsigned long i;
559 : :
560 : : if (!entry)
561 : : return;
562 : :
563 : : if (xa_is_node(entry)) {
564 : : struct xa_node *node = xa_to_node(entry);
565 : : unsigned int shift = node->shift + IDA_CHUNK_SHIFT +
566 : : XA_CHUNK_SHIFT;
567 : :
568 : : xa_dump_index(index * IDA_BITMAP_BITS, shift);
569 : : xa_dump_node(node);
570 : : for (i = 0; i < XA_CHUNK_SIZE; i++)
571 : : ida_dump_entry(node->slots[i],
572 : : index | (i << node->shift));
573 : : } else if (xa_is_value(entry)) {
574 : : xa_dump_index(index * IDA_BITMAP_BITS, ilog2(BITS_PER_LONG));
575 : : pr_cont("value: data %lx [%px]\n", xa_to_value(entry), entry);
576 : : } else {
577 : : struct ida_bitmap *bitmap = entry;
578 : :
579 : : xa_dump_index(index * IDA_BITMAP_BITS, IDA_CHUNK_SHIFT);
580 : : pr_cont("bitmap: %p data", bitmap);
581 : : for (i = 0; i < IDA_BITMAP_LONGS; i++)
582 : : pr_cont(" %lx", bitmap->bitmap[i]);
583 : : pr_cont("\n");
584 : : }
585 : : }
586 : :
587 : : static void ida_dump(struct ida *ida)
588 : : {
589 : : struct xarray *xa = &ida->xa;
590 : : pr_debug("ida: %p node %p free %d\n", ida, xa->xa_head,
591 : : xa->xa_flags >> ROOT_TAG_SHIFT);
592 : : ida_dump_entry(xa->xa_head, 0);
593 : : }
594 : : #endif
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